Resin molded body, method for producing same, and production device the present invention pertains to a means for improving fluidity of a molten resin.

Abstract

The present invention provides a means for increasing the fluidity of a molten resin by using a liquid.　The fluidity of the molten resin can be increased by adding the liquid to the molten resin. The liquid in the molten resin vaporizes at the temperature of a heating cylinder or the temperature of the molten resin, becomes dissolved in the molten resin, and is integrated between molecular chains of the resin to increase the fluidity of the molten resin. The fluidity of the molten resin increases also when undissolved gas is finely dispersed in the molten resin.　The present invention provides a means for producing a foam molded article which has a smooth and beautiful surface and in which no / less reduction in physical properties is exhibited during foam-molding of a resin including an ester structure. The means is effective for obtaining a foam molded article of a polymer alloy made of a PC-based resin and a PC having a high expansion ratio.

Description

The present invention relates to a resin molding, a method for manufacturing the same, and an apparatus for manufacturing the same.

[0001] This invention provides a means for resin injection foam molding, in which foam molding is performed using gaseous and / or (in this invention, "or / and" can also be interpreted as "at least one or more"), liquid and / or solid blowing agents at 23°C under a pressure of 1 atmosphere, known as NPT, in which the mold structure is either two-plate or three-plate or more, and the foamable resin is filled into the cavity, followed by mold backing and / or core backing to obtain a foam-molded product with a high expansion ratio. "Gaseous" refers to the gaseous state, "liquid" refers to the liquid state, and "solid state" refers to the solid state, and both refer to the NPT state.

[0002] Patent Document 1 describes a foam molding method in which a molding material consisting of a resin (plastic) and a foaming agent is short-shot into a mold with an insert, leaving an unfilled area, and then the unfilled area is filled by the expansion force of the foaming agent. The resin consists of a matrix resin and a low-molecular-weight resin of the same type as the matrix resin but with a lower molecular weight than the matrix resin. Patent Document 2 describes the gas counter pressure (abbreviated "GCP") method as a means of suppressing swirl marks (foam stripes, abbreviated "SM") that occur on the surface during foam molding, as well as the mold structure and the use of U-shaped O-rings and weighted O-rings. Patent Document 4 describes and fully explains foam molding using liquids, but does not specifically demonstrate, in examples, that water is the only effective foaming agent for foam molding of polymer alloys of PC and PC-based resins, or that foam cell refinement using a foam nucleating agent is used. Patent Documents 4, 5, 6, and 7 describe a method for sealing an ejector pin with a load-type O-ring, but do not describe a specific method for fixing an inclined pin for a slide core using a nest or the like, further securing the nest with a bolt, and sealing the inclined core rod with a load-type O-ring. Patent Documents 4, 5, 6, and 7 describe a method for increasing the expansion ratio using a mold back or core back, but in molds with three or more plates, the expansion ratio cannot be increased unless the PL is opened first. They do not describe a structure that requires the PL to be forced to open first by using a spring or other device in the PL. Furthermore, they do not describe a mold structure that allows the PL to retract a certain amount (distance) by inserting a spring or other device in both the stripper plate and the PL when opening the stripper plate first, cutting the pin gate, and then opening the PL to perform mold back or core back. Patent Documents 4, 5, 6, and 7 disclose a die structure using two sets of ejector plates, a plate on which an ejector pin, which is an extruding shaft, is arranged, and an ejector plate on which an outer cylinder that retreats before fluid pressurization is arranged, as a die device for pressure forming.In pressure molding, gas entering the molded product is a no-no. It has been shown that by retracting the outer cylinder before pressurizing the fluid to create a space between the mold and resin, and then filling the space with pressurized fluid, the pressure of the pressurized fluid is dispersed and a hollow is not created. However, in so-called hollow molding, in which pressurized fluid is introduced into the molded product to create a hollow and then pressurized from within, after sufficient pressurization, the pressurized fluid inside the hollow is no longer needed. To completely eliminate residual pressure, the gas injection pin (the fluid pressure pin that creates the hollow, the pin used for fluid pressurization) is retracted and released all at once, but this method has not been shown to easily or reliably solve the problem of bulging in blow molding. Mitsubishi Gas Chemical Company, Inc. has shown a gas injection nozzle structure (called a Shinpress nozzle) equipped with a hydraulic cylinder for blow molding, but the hydraulic cylinder gets in the way and prevents gas from being injected in the desired location. Alternatively, when gas injection from a plurality of locations is required, the installation of ejector pins on the mold is significantly restricted because the gas injection nozzles equipped with hydraulic cylinders are in the way.

[0003] Japanese Patent Laid-Open No. 08-103919 Japanese Patent Laid-Open No. 11-216748 International Publication No. 2003 / 026357 International Application No. PCT / JP2015 / 062611 International Application No. PCT / JP2015 / 069216 International Application No. PCT / JP2016 / 086380 International Application No. PCT / JP2020 / 15536

[0004] The problem with this invention is that in order to obtain a foam-molded product with a high expansion ratio, it is necessary to open the cavity by molding back or core-backing after filling the cavity with a foamable resin. Molten resins generally have low fluidity. Engineering plastics and super engineering plastics in particular have low fluidity, making it difficult to process thin-walled molded products.

[0005] A mechanism (tip opening mechanism, mold opening mechanism, mold opening mechanism) that forcibly opens the PL of the mold when mold back or core back is performed is incorporated into the mold. By mixing water, alcohol, hydrocarbons, etc. into the molten resin, the viscosity of the molten resin decreases and molding processability improves. Configuration, operation, and effect of the invention

[0006] (Configuration) The first invention described above involves placing resin in a molding machine's heating barrel and melting it (heating it to a melting point). The molten resin (resin in the screw's melting zone) is then compressed to increase the density of the molten resin (resin in the screw's compression zone). A volume-controlled amount of a substance that is liquid at a temperature of 23°C and a pressure of 1 atmosphere (76 mmHg, 1013 hectopascals) is then poured into the heating barrel. The vapor is vaporized by adjusting the heating temperature and the resin temperature. The resulting vapor is then pressurized and dissolved and / or finely dispersed in the molten resin by the force of the screw's rotation, reducing the viscosity of the molten resin and improving its fluidity. The improved fluidity of the molten resin reduces flow resistance when filling the cavity, making molding easier (filling at lower pressures). The molten resin, whose viscosity has been reduced and fluidity improved by the vaporized liquid, is then filled into the cavity with a cushioning screw (the cushioning is provided so that resin dwell pressure can be applied after filling). After filling, the screw applies resin dwell pressure to crush the foam layer and foam cells, increasing the density of the molten resin. While liquid is used, as shown in Patent Document 4 and elsewhere, liquid acts as a foaming agent, so using resin dwell pressure is effective for producing molded products without foaming or foam layers. Other methods, such as high-pressure GCP, blow molding, and pressure molding, also crush the foam layer and foam cells, forcing the foaming gas and liquid out of the molded product. Molded products obtained in this manner have almost no weight difference compared to those molded without liquid. Because of the increased fluidity, resin dwell pressure is transmitted sufficiently. In some cases, the product may be heavier than without liquid. Such weight varies depending on the resin dwell pressure.

[0007] In some cases, a gas may be used in combination with the liquid as needed to increase fluidity. Conventional injection foam molding (filling into the cavity) conditions for hydraulic machines generally involve pushing the screw all the way to the forward end, since no holding pressure is used. If necessary, to avoid the reaction during filling (the screw is returned by the pressure (reaction force) of the molten resin filled into the cavity), a weak holding pressure is applied for a short period of about 0.5 seconds after the screw is pushed all the way to the end, and the screw is stopped there to stabilize the amount of molten resin filled into the cavity and stabilize the foaming. With an electric motor, the screw is pushed all the way to the VP switch position, and then, if necessary, the screw is stopped to stabilize the filling amount. In this invention, neither hydraulic nor electric motors are used to fully push the screw. Instead, a sufficient cushion volume, e.g., approximately 20% of the product weight, is provided, as in conventional general molding. After filling the cavity with the molten resin containing the liquid or gas, sufficient pressure and time are applied to hold the resin. This liquid is used to eliminate, for example, cosmetic defects such as sink marks. This is a significant difference from conventional injection foam molding. In other words, this invention is a general molding process using a resin with a significantly improved fluidity and reduced viscosity, using a liquid or other material. While the use of the liquid has been shown to increase the fluidity of the molten resin, simply applying a fine texture or a ceramic coating such as TiN, CrN, WC, or DLC to the mold surface, i.e., the surface that comes into contact with the molten resin (not only the fixed side of the design surface, but also the movable side of the non-design surface), can also enhance the fluidity. Therefore, when combined with the use of the liquid or gas, the fluidity is further improved through a synergistic effect. A shut-off nozzle is preferably used to prevent dripping. It has been explained that a liquid is poured into the heating barrel, but it is also possible to provide a port in the nozzle for injecting the liquid and inject the liquid at the stage of injecting the molten resin, thereby pressurizing it to melt it and finely disperse it, thereby increasing the fluidity of the molten resin.

[0008] (Differences between foam molding and general molding.) When thermoplastic resin is heated and melted in a heating barrel, it becomes molten and fluid. This is sometimes referred to as the "molten state," or "a state with or made to have fluidity," "a state capable of flowing," or "a state of being heated and melted and having or made to have fluidity." Inside the heating barrel, the molten resin is subjected to back pressure and other factors, resulting in a somewhat higher density. When the molten resin in the heating barrel begins to be injected (filled) into the cavity, the molten resin filling the cavity is released from the pressures exerted on it, such as back pressure and filling pressure within the heating barrel. If the molten resin is filled to the brim (assuming the cavity volume is the same as the volume of the molten resin) and then allowed to cool and solidify within the cavity, the volume of the molten resin will decrease by approximately 5% for styrene-based resins such as ABS and approximately 10% for olefin-based resins such as PP. This is mold shrinkage, which results in the appearance defect known as "sink marks" in molded products. To eliminate these sink marks and obtain molded products with a clean, smooth surface and no noticeable sink marks, a process known as "resin dwell" is typically performed. The molding machine's screw is used to fill the cavity with a larger amount of molten resin than the volume filled (the amount equivalent to the volumetric shrinkage, e.g., 5% or more for ABS), increasing the resin's density and eliminating the sink marks (this process is called "resin dwell"). Naturally, higher dwell pressure increases the resin density and reduces sink marks, but it also increases the risk of flash formation on the PL. Applying resin dwell pressure increases the resin density near the gate and decreases the density at the end of the flow. Increasing the resin dwell pressure increases this difference, resulting in greater internal stress in the molded product and greater warpage and deformation. The inventor previously observed mass production of automotive parts using a high resin dwell pressure of 100 MPa. There are some molded products for which it is not possible to eliminate sink marks caused by ribs, etc. unless the pressure is increased to this level.

[0009] If so, in order to minimize the pressure holding effect between the gate and the end of the flow, increasing the melting temperature of the resin will increase (improve) the fluidity, and the pressure holding effect will reach the end of the flow, but when the temperature of the molten resin is increased, the density of the resin in a molten state becomes lower, and as a result, the sink marks will become larger compared to the molded product before the temperature of the molten resin was increased.In addition, the time required for cooling and solidification will be longer, which will reduce productivity.

[0010] In this case, as a means of increasing the fluidity of the resin without raising the resin temperature, the resin can be improved or modified using flow aids, flow improvers, low molecular weight resins, etc., as described below. However, in this case, an increase in the unit price of the resin due to the use of additives to the resin is unavoidable, and as a result of improving or modifying the resin with additives, the physical and chemical properties of the resin are reduced, resulting in a decrease in the strength of the molded product.

[0011] (Means for Improving Resin Fluidity Using a Liquid.) The inventors have adapted the technical content of a previously filed liquid-based foam molding method (see International Application No. PCT / JP2015 / 062611, including Patent Document 4) to solve the problems of using a liquid as a foaming agent, as in Patent Document 4. Instead, by adding a volatile, vaporizable, low-boiling liquid to the resin in the melting stage in the heating barrel, the liquid acts as a fluidity improver. They have found that the fluidity of the molten resin can be significantly improved without raising the temperature of the molten resin or using additives. Furthermore, they have found that by using a dwell pressure, the liquid can be squeezed out of the molded product at a pressure similar to that used during general molding, without requiring a high dwell pressure. Using a liquid solves the aforementioned problems associated with increasing the melt temperature, as well as the economical and property-deteriorating problems associated with using additives.

[0012] Patent Document 4 and other publications also describe the use of resin dwell pressure in injection molding processes using a liquid to impart foamability. However, this raises the risk of the screw returning due to the pressure of the foamable resin filling the cavity. If the screw returns due to the reaction of the foamable resin filling the cavity (the force of the foamable resin filling the cavity (the foaming force of the filled foamable resin, the reaction force of the foamable resin trying to return inside the screw, etc.)), the weight of the foam-molded product will vary greatly, resulting in short molds and overpacking. In the case of foam molding, if a dwell pressure of approximately 30% of the conventional resin dwell pressure is applied for approximately 0.5 seconds after the cavity is fully filled with the foamable resin (the filling pressure, temporary pressure completion stage), the screw will not return, resulting in a foam-molded product with a stable weight. Applying a dwell pressure of several seconds, or even several tens of seconds, at a high pressure similar to that used in general molding, as in the present invention, will cause the foamed core formed from the liquid to collapse. Since the purpose is to crush the resin, high pressure (pressure that increases the density of the resin) is applied for a long time {to fully transmit (act) the action and effect of the resin dwell pressure to the molten resin in the cavity.} In other words, there is a difference in the purpose and process of the dwell pressure, and this is where Patent Document 4 and other documents differ from the present invention. This invention uses a liquid foaming agent, but is characterized by not foam molding. Patent Document 4 and other documents state that the screw stops at the forward end, but in this invention, resin dwell pressure is applied after filling, so a cushion amount is left during filling.

[0013] Patent Document 4 and other publications describe the Gas Counter Pressure (GCP) method (or simply "GCP"). This method describes a means or process for eliminating swirl marks during foam molding and producing foam-molded products with clean, smooth surfaces. The present invention also aims to improve the fluidity of molten resins, eliminating swirl marks (which can also be considered silver streaks caused by the use of liquids). This is similar to the case of undried ABS, which will be discussed later. GCP is necessary to obtain general molded products with clean, smooth surfaces free of liquids or silver streaks due to other reasons. In this case, the GCP pressure may collapse internal foam cells, so it can be higher than the 1 MPa used in the examples of Patent Documents 4 and 5. When pressure molding is also used, the high-pressure gas injected into the gap between the resin and the mold collapses the foam cells, resulting in a solid product (without a foam layer). Therefore, the process, purpose, action and effect of the GCP of the present invention are different from those of the GCPs shown in Patent Documents 4 to 7. However, the purpose of applying the embossing process to avoid the raindrop phenomenon (i.e., the entrapment of gas in the GCP) is the same.

[0014] If the fluidity is increased by using a liquid, the packing pressure can be reduced, and the internal stress of the molded product will be reduced. As a result, a regular molded product can be obtained that has little warping or deformation but does not have a foam layer inside. If the fluidity is increased by using a liquid, the resin packing pressure (via the spool, runner, and gate) can be reduced, so the difference in packing effect between the area near the gate and the end of the flow (the difference in the packing pressure transmitted) will be smaller. As a result, there will be less flash on the PL near the gate and on other PL. Resin whose fluidity has been increased using a liquid has less resistance to filling into the cavity. The resin packing pressure can also be reduced, which results in a reduction in mold clamping (closing) force. This means that large molded products can be processed using a molding machine with a smaller mold clamping force, which saves energy.

[0015] As mentioned above, once the liquid in the molten resin has completed its role of improving fluidity (i.e., once the molten resin has completely filled the cavity), it is squeezed out by the resin dwell pressure and does not remain in the molded product. The strength of the general molded product obtained in this manner is no different from that of a general molded product made using a general resin without any fluidity-improving modifications. In fact, the resin density is increased even further, resulting in a molded product with higher strength. This is also a difference from foam molding, as described in Patent Document 4. The foam cells inside foam molding are actually sink marks that occur internally. In other words, foam molding is a molding method that moves sink marks inward. In foam molded products made of ABS, HIPS, etc., swirl marks on the surface reduce impact strength by approximately 60% to 70%. Even when a skin layer is formed on the surface using the gas counter pressure (GCP) method, impact strength is reduced by approximately 30%. Even with foam molding using a liquid like this, which leaves no foam residue in the molded product, it is still foam molding, so even with the weight reduction (5 wt. % weight reduction) achieved by not using dwell pressure, there is a significant decrease in physical properties. The strength of a general molded product using resin dwell pressure is roughly the same as that of a general molded product that does not have internal foam cells and that uses a liquid to increase fluidity, rather than foam molding using resin dwell pressure. This is the invention of improving fluidity using a liquid of the present invention, and the inventor claims these differences from patent document 4 and other documents as the novelty and inventive step of this invention. The liquid injected into the heating barrel to increase the fluidity of the molten resin in the heating barrel can be a single type, or several types can be mixed together.

[0016] Not only liquids but also gases may be used in combination (when gases are used in combination in the present invention, the phrases used are "liquids in combination with gases as needed," "liquids in combination with gases as needed," or simply "liquids and gases," and are used in this way because the present invention asserts that gases can be used in combination with liquids). Here, the "stage" of melt-kneading refers to the stage at which the molding material begins to melt due to the heat of a heater or the like provided in the heating barrel, for example, the stage at which about half of the material is melted, the stage at which it is almost melted, or the stage at which it is completely melted. The "process of filling the cavity" refers to the process of filling the cavity (molding space), and refers to any of the stages at which filling begins, or the stage at which about 80% of the cavity volume is filled, or the stage at which filling is almost complete, or the stage at which filling is complete (for example, the completion of primary pressure in an injection molding machine).

[0017] The "process of increasing the density of the resin" generally refers to filling the cavity with molten resin and then applying a dwell pressure to the resin using a screw, as well as blow molding, which uses a gas at atmospheric pressure or higher to pressurize the molten resin from the inside, pressure molding, which injects the gas into the gap between the resin and the mold and pressurizes the resin from the outside, and compression molding, which uses the mold clamping mechanism of the molding machine. In some cases, these methods may be used in combination.

[0018] To stabilize this resin holding pressure, the inventor has found that there are two types of molding machines: one with a specification (program) that allows the time (t1) for filling (primary pressure) and the time (t2) for resin holding pressure (secondary pressure, tertiary pressure, etc.) to be set independently and separately, and one with a specification that controls the total time of t1 and t2, i.e., t = t1 + t2. To stabilize the action and effect of holding pressure for each shot, it is preferable to be able to set t1 and t2 separately. Of course, it is also possible to control the total time of t = t1 + t2.

[0019] (Actions and Effects) The increased resin fluidity reduces resistance to filling into the cavity. The enhanced holding pressure allows for lower cavity filling and resin holding pressure than conventional molding. This is superior to conventional molding without the use of liquids or gases, resulting in fewer sink marks and less flash, such as PL, even at low holding pressures. Furthermore, because the resin holding pressure is set low, the resulting molded product exhibits less warpage and deformation than conventional molded products. The reduced filling resistance allows for lower resin holding pressure, which in turn reduces mold clamping force, enabling the processing of molded products with large projected areas using smaller injection molding machines with lower mold clamping force. This reduces processing costs and energy consumption. For molding resins with low fluidity, such as super engineering plastics and molding materials containing inorganic fillers, the use of liquids and, if necessary, gases to improve the fluidity of molten resins allows for a wider range of molding conditions to be set, making molding easier.

[0020] (Configuration) The second invention described in claim 2 shows a process of filling a cavity with molten resin whose fluidity has been increased by using a liquid or the like, and then applying a resin dwell pressure to increase the density of the resin.

[0021] (Actions and Effects) The second invention described in claim 2 fills a cavity with molten resin whose viscosity has been reduced and whose fluidity has been increased using a liquid or other means. Because the fluidity of the molten resin is increased by the liquid or other means without increasing the melting temperature, when applying dwell pressure to the resin after filling, the effect of the dwell pressure transmission is enhanced, resulting in a higher effect and effectiveness of the dwell pressure compared to when the fluidity is not increased. Using a dwell pressure that is higher than necessary to eliminate sink marks results in molded products with significant warpage. Using a high dwell pressure increases the occurrence of flash on the PL and shortens the mold life. Using a high dwell pressure naturally requires a high mold clamping force, which requires a larger molding machine, which is uneconomical. Molded products processed using resins with increased fluidity eliminate the above problems.

[0022] (Configuration) The third invention described above uses the liquid of the first invention described above, and also gas if necessary, to fill a cavity with molten resin whose fluidity has been increased. A high-pressure gas is then injected into the molded product to create a hollow space inside the molded product, and pressure is applied from the internal hollow space. Furthermore, the molten resin may be pressurized from the outside by simultaneously applying pressure to the resin. Compressed air molding may also be used if necessary.

[0023] (Actions and Effects) The third invention described above relates to the production of hollow molded products. In the case of blow molding, when the viscosity of the molten resin decreases (i.e., fluidity improves; in the case of highly fluid molten resin), the pressure of the injected gas can be reduced, resulting in lower internal stress, resulting in a hollow molded product with high dimensional accuracy and minimal warping or deformation.

[0024] (Configuration) The fourth invention described above uses the liquid of the first invention described above, and also gas if necessary, to fill the cavity with molten resin whose fluidity has been increased, and introduces a high-pressure gas into the gap between the mold and the molten resin, pressurizing the molten resin from outside with the gas to increase the density of the resin. At this time, resin pressure dwell and blow molding are also used if necessary.

[0025] (Actions and Effects) The fourth invention described above relates to the production of pressure-molded products. In the case of pressure molding, when the viscosity of the molten resin decreases, high-pressure gas easily enters the gap between the resin and the mold. Furthermore, the action and effect of the high-pressure gas compression (compressed air) from one side of the molten resin in the cavity (generally the movable side of the non-garment surface) to the other decorative surface (generally the fixed side) is enhanced, improving transferability to the mold. When a highly fluid molten resin is used, the pressure of the pressure-molding gas can be reduced, resulting in a pressure-molded product with less warping and deformation. Furthermore, transferability can be further improved by using resin holding pressure in combination. Blow molding may also be used if necessary.

[0026] (Configuration) The fifth invention described in claim 5 is the invention described in claims 1 to 4, in which a sealed mold is used to pressurize the mold with air at atmospheric pressure or higher (by applying a GCP process), and molten resin whose fluidity has been increased by using a liquid, and if necessary, a gas, is then filled into the mold.

[0027] (Actions and Effects) The fifth invention, in addition to the inventions described in claims 1 to 4, uses a sealed mold in which the mold is pressurized (pre-pressurized) to atmospheric pressure or higher, and then fills the mold with molten resin whose fluidity has been increased by using a liquid, and optionally a gas, in the GCP process, thereby producing molded products, blow molded products, and pressure molded products with clean, smooth surfaces free of swirl marks (foam stripes) caused by vaporized liquid and gas. When the fluidity of the molten resin is high, GCP makes it possible to process molded products with fewer or no swirl marks even at low-pressure GCP (pressurization inside the mold).

[0028] (Configuration) In the ninth invention described in claim 9, liquid is first introduced into the injection port closest to the hopper on the heating barrel of the molding machine, where the viscosity of the molten resin is reduced by the vapor generated by the vaporized liquid. Gas is then injected into the molten resin containing the vaporized liquid through another injection port. This order is not limited to injection molding, but can also be implemented in extrusion molding machines. To prevent the liquid vapor or gas from escaping to the hopper side through the screw, a backflow prevention ring (check valve) is provided at the rear (behind the injection port through which the liquid is injected, allowing it to escape (leak) to the hopper side). This structure is not limited to the screw of an injection molding machine, but can also be implemented in the screw of an extrusion molding machine.

[0029] (Operation and Effect) In the ninth invention described in claim 9, a liquid is first injected into the molten resin in the heating barrel, and the vapor of the evaporated liquid lowers the melt viscosity of the molten resin. A gas is then injected into the molten resin with this reduced viscosity. Compared to when the liquid is injected first, the viscosity of the molten resin is lowered, so the gas easily enters, and because the viscosity is low, the gas is easily dissolved or finely dispersed in the molten resin by the back pressure and the force of the screw rotation.

[0030] The ninth aspect of the present invention describes a backflow prevention ring at the rear to prevent foaming gas from escaping (leaking) from the rear hopper. The backflow prevention ring prevents the metered, plasticized molten resin from being sent to the front of the screw, preparing for injection. In foam molding, foaming is imparted (added) using a liquid, gaseous, or solid foaming agent. This foaming force prevents the resin from returning to the screw (during metering, back pressure is applied, so there is no risk of it returning, but after metering is complete and before filling begins, when the resin is stored in front of the heating barrel, there is a risk of it returning to the screw due to the foaming force). A separate backflow prevention ring is provided at the rear of the screw head to prevent backflow to the screw during injection. It is desirable to stop the screw and reverse rotation during the final stages of plasticization and metering to completely close the backflow prevention ring at the rear of the screw head.

[0031] (Actions and Effects) By providing backflow prevention rings 239 and 240 at the rear of the screw, the liquid vapor introduced into the heating barrel during the metering and plasticization stage, vaporized by the temperature of the heating barrel and the temperature of the molten resin, does not escape into the hopper, stabilizing the foaming power. In particular, in the case of gas, which tends to escape into the hopper, it is advisable to provide these backflow prevention rings. In the case of liquid, the liquid is introduced in the compression zone, where the resin is melted and wrapped around the screw. The molten resin wrapped around the screw functions as the backflow prevention rings 239 and 240. There is no problem with providing these backflow prevention rings. When using both gas and liquid in this invention, the liquid is introduced first, followed by the gas.

[0032] Once the metering is complete, there is a short delay, and the screw is rotated slightly in the reverse direction to close the front backflow prevention ring 235. This prevents the molten resin, which has been given foaming properties by the liquid, gas, or solid, from flowing back toward the screw, stabilizing the weight of the molded product. As mentioned above, this provides the following effects and advantages: stabilizing the effect of resin holding pressure.

[0033] (Configuration) Claim 10 describes how simply molding a molding resin containing inorganic and organic fillers, powders, or bulk materials (e.g., paper pulp, paper chips, etc.) to improve the resin's physical properties results in the additives floating on the surface of the molded product, making it unsuitable for use in molded products and parts requiring a high level of appearance. It has been confirmed that when the additives are added to a highly fluid resin, the inorganic and organic materials sink more than when a less fluid resin is used. By using a liquid, and optionally a gas, to improve fluidity, the surface floating of the additives can be suppressed. Furthermore, by adding a gas-containing polymer (GC), the additives are contained within the molded product, resulting in a clean, smooth molded product without any floating additives on the surface. This is the result of increasing the fluidity of the molten resin with a liquid and / or gas. By increasing the fluidity of the molten resin, the additives sink when added with a gas-containing polymer (GC). The resin additive acts as a foam nucleating agent, so inorganic and organic substances sink into the GCP. The fluidity is improved by adding gas to the liquid as needed, and the synergistic effect with the GCP results in a clean, smooth surface with no floating of the resin additive.

[0034] (Actions and Effects) Injecting gas into the molten resin, if necessary, increases the fluidity of the molten resin. Therefore, the effectiveness of GCP is enhanced when using a highly fluid resin, and as mentioned above, there is no floating of the resin additive. The inventors used PP containing 20 wt.% talc and ethanol as a blowing agent in the range of 1.5 wt.% to 2.5 wt.%. Without GCP, talc floating was observed on the surface of the molded product, although less than in conventional molding. When GCP was used with air at 1 MPa pressure, there was no talc floating at all, and the surface was clean and smooth. The talc content was increased to 40 wt.% and 60 wt.%, but the GCP effect was sufficient, and there was no talc floating in either case. For polyamide containing 50 wt. % glass fiber, when 1 wt. % city water was used as the liquid, the fluidity of the liquid was improved and the floating of the glass fiber surface was improved with GCP.

[0035] Molded products in which the resin additive has been sufficiently sunk have good adhesion of the coating film, and even after 240 hours of SST (salt spray test), no blisters or other problems of the coating film caused by the presence of the resin additive on the surface occur.

[0036] It was confirmed that the use of a liquid, and optionally a gas, to increase fluidity and improve molding processability using GCP has a significant effect.

[0037] It was confirmed that the GCP pressure required to obtain a standard molded product or foam molded product with a clean, smooth surface can be significantly reduced when the fluidity is increased by adding about 2 wt.% ethanol or propanol compared to the GCP pressure required when using the same resin with high fluidity (resin that has not had its fluidity increased by a liquid). GCP is effective in suppressing silver in standard molding and swirl marks in foam molding, but it can be a nuisance when filling the cavity with molten resin as it can cause discoloration and burning of the resin, so a lower GCP pressure is better.

[0038] The inventors separately machined and installed a dulmage-shaped high-mixing component between the screw head and the screw body of a conventional injection molding machine (or extrusion molding machine). This lengthens the screw (increasing the L / D ratio), making it convenient for using more liquid, and optionally gas. However, it would obviously not fit into the heater barrel as is, so the inventors machined and installed a spacer (a component that extends the heater barrel) between the nozzle head and the heater barrel long enough to accommodate the dulmage. Holes can be drilled in this spacer to allow liquid or gas to be introduced through them, eliminating the need to drill holes in the heater barrel. By incorporating the dulmage at the tip of the screw in this way, concerns about discoloration and burning of the resin due to high mixing and high compression, which were a concern with conventional screws that incorporate dulmage into part of the screw, can be eliminated by installing it at the front of the screw.

[0039] One of the main features of this invention is to apply a dwell pressure to eliminate foam cells. In this case, it is preferable that the weight loss (weight loss) when using liquid, and if necessary gas, relative to the weight of a general molded product is within 5 wt.%. This 5 wt.% is based on the 94UL standard.

[0040] The "resin molded product" in the claims refers to a molded product made of a resin whose main component is a thermoplastic resin, and the thermoplastic resin contains inorganic or organic reinforcing agents and other additives. The "mold device" refers to a sealing mold, blow molding mold, or pressure molding mold for implementing the GCP described in this invention. The "molding device" refers to an injection molding machine, extrusion molding machine, and nitrogen gas separation device, gas compression device, gas injection device, GCP device, etc. used in the blow molding and pressure molding systems described in this invention.

[0041] BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is a schematic diagram (cavity side) of the molded product used in the comparative example and the example. The mold for this molded product had a sealed mold structure for GCP, as shown in Figures 2 and 3 of PCT / JP2016 / 86380. Figure 2 is a schematic diagram (core side) of the molded product used in the comparative example and the example. Figure 3 is a foam-molded product made from PC resin (SD Polyca (trade name) 301-15 (grade)) using city water with a total hardness of 18 ppm. Coarse foam cells of approximately 2 to 5 mm are observed, indicating that the city water acts as a blowing agent. This is a photograph of the foam-molded product of Example 7 before mold backing. The coarse foam cells are due to the absence of a foam nucleating agent. Figure 3 was not subjected to GCP, so swirl marks are visible on the surface. (Figure 4) Immediately after the GCP evacuation, the movable mold of the molded product in Figure 3 was retracted by 1 mm, and the mold back was performed from a 2 mm plate thickness to 1 mm immediately after the GCP evacuation, increasing the expansion ratio. The mold back reduces the pressure of the resin in the molded product, resulting in foam cells that grow to 10 mm, and in some places even 20 mm. Despite the molded product having such large foam cells, the mold was pressurized to 1 MPa using the GCP device shown in Figure 15, and water was added under pressure to impart foamability. The surface of the PC molded product was clean and smooth, with no swirl marks at all. (Figure 5) is a photograph of the foam molded product of Example 10. This mixture of 90 parts 301-15 pellets and 10 parts SI8000L pellets (containing a light diffuser (bubble nucleating agent)) was used as the foam nucleating agent. Compared to Figures 3 and 4, the foam cells were finer, with sub-1mm cells uniformly dispersed throughout the molded part. The cells were approximately 1mm in diameter and were present throughout the molded part. Thanks to the effects of GCP, the molded part surface was clean and smooth, with no swirl marks. (Figure 6) This is a schematic diagram showing the PL opening mechanism incorporated into the mold, which must open first during mold back and core back. The "PL" in Figures 6, 7, and 8 is an abbreviation for the parting where the fixed and movable mold surfaces meet. (Figure 7) A schematic diagram showing that the PL must open first when mold-backing or core-backing, so a mechanism that opens the PL first has been incorporated into the mold.(Figure 8) A schematic diagram showing stack molding with the mold opening and closing vertically, the injection unit (injection device) positioned horizontally, and PL injection. (Figure 9) A schematic diagram showing a tension bolt. (Figure 10) A photograph of an actual molded IC tray. (Figure 11) A schematic diagram showing the mold-back process (PL is a flat edge). This shows the state in which the mold is closed and the cavity (reference number 45) is filled with foamable resin, with the movable mold (reference number 44) not retracted. (Figure 12) A schematic diagram showing the state after retracting reference number 44 from Figure 11, expanding the cavity at reference number 45 and increasing the foaming ratio. PL has been molded back. Reference number 44 shows the state in which the cavity has expanded and the foaming ratio has increased. Reference number 45 indicates that a gap (reference number 46) has appeared in the PL. Since increasing reference number 45 would increase the risk of flash, it cannot be retracted too far. (Figure 13) is a schematic diagram showing the core-back process (PL is a vertical parting). The mold is closed, and the state in which the foamable resin has been filled into the cavity (reference number 48) is shown. The movable mold (reference number 44) is not retracted in Figure 13. Reference number 50 is advanced. (Figure 14) is a schematic diagram showing the movable mold being retracted and the cavity being expanded. Even though there is a large gap in the PL (reference number 53), the mold (PL of the mold) has a vertical parting (resin part 49 and mold part 50), so there is no problem with burrs. Even if the opening (opening) amount of the PL (the distance it is retracted) is large, the part referenced 49 is still present, so the problem of burrs is reduced. If the retreat distance is increased in order to obtain a foam-molded product with a high expansion ratio, the foaming force generated by the use of a foaming agent alone will result in the foam resin filling the cavity (reference number 54) moving away from the mold and poor transferability if the expansion rate is slower than the rate of expansion of reference number 54. To solve this problem of poor mold transferability, particularly when a high expansion ratio foam-molded product is desired, pressurized fluid is injected into the molded product from the nozzle of the molding machine, or / and from the spool / runner, or / and directly into the molded product, creating a hollow interior. The pressure of the high-pressure fluid (gas) in the hollow expands reference number 54 while maintaining transferability to the mold. The pressure of the pressurized fluid injected into the molded product can be reduced before or after the completion of expansion, after a delay time has elapsed.This method produces foam-molded products with high expansion ratios, even exceeding several times or even ten times. (Fig. 15) This GCP device pre-pressurizes the mold, creating pressure, and then releases the compressed air after the foamable resin is filled. The control of this GCP device (opening and closing the compressed air and exhaust valves) is programmed into a programmable logic controller (PLC) built into the molding machine. (Fig. 16) This is a diagram (table) showing the adhesion of the coating when the foam-molded product of Example 10 was coated with Repelle #1100 (a Tohpe Corporation product name). (Fig. 17) This is a schematic diagram showing the undercut (reference number 57) that can be treated using a slide core. This seal is also used in molds for pressure molding described in International Application Publications PCT / JP2015 / 069216, PCT / JP2016 / 086380, and PCT / JP2020 / 15536 ​​(collectively referred to as the "previously listed international application publications"). (Figure 18) is a schematic diagram showing an undercut (reference numeral 59) that can be processed using a tilted core (tilt core slide, tilt slide, tilt pin). This seal is also used in molds for pressure molding described in the previously listed international application publications. (Figure 19) is a mold structure diagram (ejector box sealing mold structure) for a sealing mold used in a GCP foam molding process, in which the ejector mechanism is enclosed and sealed with a spacer block. (Figure 20) This is a diagram of a mold structure for a sealed mold used in GCP foam molding, with each ejector pin sealed with a weighted O-ring or a concave O-ring. Figures 19 and 20 can also be used for pressure molding, in which a high-pressure fluid (gas or liquid) (pressures greater than atmospheric pressure (1 atm, 1 atmosphere, 760 mmHg)) is inserted into the gap between the mold and the resin, pressurizing the resin with the force of the pressurized fluid. Pressure molding, using a mold with an ejector box structure like that of Figure 19, requires a large amount of pressurized fluid (liquids are difficult to use in this case), making it economically unsuitable. The mold structure with sealed ejector pins like that of Figure 20 requires less pressurized fluid, making it more economical. (Figure 21) When pre-pressurizing cavities 55 and 56 in GCP, a compressed air circuit is installed in the PL (reference number 61) of the mold.The compressed air inside the mold is moved through a pressurized circuit inside the mold by the force (pressure) of filling when molten resin is filled into reference numbers 55 and 56. This is a structural diagram of a mold that shows how the compressed air is then exhausted. (Fig. 22) is a schematic diagram showing that when pressurizing the cavities 55 and 56, the compressed air fluid (gas) passes through, but the resin is stopped here because the gap (reference number 100) is thin. The compressed air (L) into the cavities 55 and 56 ２) circuits (reference numerals 92, 98, and 100). (Figure 23) shows a method for sealing a tilted core with a weighted O-ring in GCP and pressure molding. Reference numerals 108 and 106 must be aligned, so this is a schematic diagram showing how they are installed at an angle using a nest 113. The groove for 106 can be machined into either 113 or 87. In Figure 23, reference numerals 103 and 106 are installed at 87, but the installation location is not limited; reference numeral 101 can also be used. To prevent damage to the insides (sealing surfaces) of 70 and 108 when assembling the mold, stepped components (e.g., stepped ejector pins) are used for 70 and 108. Apply Krytox (trade name) to the inner surfaces of 103 and 106, the stepped ejector pins, and the stepped shafts, especially the stepped portions, and then slowly insert them while rotating.) This sealing means is used not only in GCPs but also in molds for performing pressure forming as described in the aforementioned International Application Publication No. PCT / JP2015 / 069216, PCT / JP2016 / 086380, and PCT / JP2020 / 15536. Reference numeral 106 is fixed from above by the insert 113, but insert 113 can also be used to fix reference numeral 106 from below. (Figure 24) is a schematic diagram showing a structure in which multiple inclined pins are sealed with a weighted O-ring (by increasing the number of seal plates) when there are multiple inclined pins. This sealing means is also used in molds for performing pressure forming as described in the aforementioned International Application Publication No. PCT / JP2015 / 069216, PCT / JP2016 / 086380, and PCT / JP2020 / 15536, as described in Figure 23. As described in Figure 23, reference numeral 106 can be fixed from below using insert 113, not limited to from above. If necessary, a mixture of top and bottom injections may be used. To improve sealing performance, multiple reference numbers 106 may be used on a single extrusion shaft. To further improve sealing performance, weighted O-rings (W) may be used on the top and bottom. (Fig. 25) A schematic diagram showing a mold structure suitable for blow molding using foamable resin and non-foamable resin. (Fig. 26) A schematic diagram showing a mold structure for pressure molding. (Fig. 27) A diagram showing the inner core of a pressurized fluid injection pin used in blow molding. (Fig. 28) A diagram showing the outer tube of a pressurized fluid injection pin used in blow molding.(Fig. 29) An assembly diagram of the pressurized fluid injection pin consisting of Fig. 27 and Fig. 28. (Fig. 30) A diagram showing the inner core of the pressurized fluid injection pin used in pressure molding. (Fig. 31) A diagram showing the outer cylinder of the pressurized fluid injection pin used in pressure molding. (Fig. 32) An assembly diagram of the pressurized fluid injection pin for pressure molding consisting of Fig. 30 and Fig. 31. (Fig. 33) An assembly diagram of the pressurized fluid injection pin for pressure molding consisting of Fig. 30, Fig. 31, and Fig. 32. (Fig. 34) A schematic diagram of the GCP device (see Fig. 15), not showing the pressure gauge, other connecting couplers, hoses for pressurizing (connecting) the mold, etc. (Fig. 35) A schematic diagram of the device for performing blow molding and pressure molding, not showing the pressure gauge, safety valve, check valve, other connecting couplers, hoses for directing pressurized fluid to the mold, etc. (Figure 36) This is a schematic diagram showing the mechanism for forming a hollow portion inside the molded product during blow molding, retracting the plates consisting of 117 and 118, and suddenly releasing pressurized fluid into 122, equalizing the pressure inside 122 with the outside. When molten resin fills into reference numerals 55 and 56, the ejector rod of the molding machine advances, resulting in reference numeral 120 being at the forward end. (Figure 37) This is a schematic diagram showing the structure for forming a dummy shape with a shutter (when the shutter is closed). (Figure 38) This is a schematic diagram showing the structure for forming a dummy shape with a shutter (when the shutter is open). (Figure 39) This is a schematic diagram showing the automatic gate cutting mechanism (before cutting). (Figure 40) This is a schematic diagram showing the automatic gate cutting mechanism (after cutting). (Figure 41) This is a schematic diagram showing a molded product 4 with a gate cut and a runner 176. (Figure 42) This is a dummy shape installed to reduce the pressure of the molten resin filling the cavity (used mainly in foam molding in the case of short molds). (Figure 43) A dummy shape installed to reduce the pressure of the molten resin filled in the cavity (in the case of a full pack, this is mainly done by blow molding or pressure molding).(Figure 44) A QR code (reference number 206) containing information necessary for recycling is engraved on the mold of a molded product. Scanning the QR code with a barcode reader reveals all the information necessary for recycling (such as the weight of the molded product, the manufacturer's name, product name, grade, type of resin, type and amount of additives, and, if painted, paint-related recycling information). Figure 44 shows an injection-molded product made primarily of the thermoplastic resin PP, containing 20 wt.% environmentally degradable components, molded using an injection molding mold engraved with a QR code. Reading this QR code and sending it to a computer or other device for comparison with a database facilitates recycling. Knowing the content of environmentally degradable components allows for quick and easy determination of whether the product can be burned for thermal energy recovery or used as a raw material for recycled resin production. Reference numeral 206 denotes the QR code of the molded product, which contains the information necessary for recycling and is printed on the injection molding to which the mold's QR code has been transferred. (Figure 45) is a schematic diagram of an extruder equipped with a weight feeder. The device consists of reference numerals 185 and 198. The weight feeder controls the amount of material fed into the heating barrel 192 by the rotation speed of the feed screw 198. Figure 45 shows a design in which the amount of each material is weighed before being fed into 192 and then fed into 192. Each material is fed into 192, and mixing is achieved by the rotation and mixing force of 193. (Figure 46) is a schematic diagram of an extruder equipped with a weight feeder. The difference from Figure 45 is that it is a schematic diagram of a device that can add materials to be mixed into the molten resin in 192 after melt-kneading. As with Figure 45, the amount fed is controlled by the rotation of the feed screw 198. In addition to the powders and pellets of environmentally degradable substances described in this invention, the materials to be added to the molten resin can also include ceramic powders, metal powders, etc., and can also be used to produce pellets containing these.As shown in Figures 45 and 46, the environmentally degradable component, ceramic powder, or metal powder is mixed into the thermoplastic resin and pelletized to increase the content of each material (environmentally degradable component, ceramic powder, metal powder, etc.) in the pellets. By adding the environmentally degradable component, ceramic powder, or metal powder to the pellets, the content (broadly defined concentration) of the environmentally degradable component, ceramic powder, or metal powder in each pellet can be increased. (Figure 47) Photographs of parts (back-up ring 199, load-type O-ring 200, spacer 201) for sealing the ejector pin, tilted core pin, etc. (Eighteenth embodiment) Figures 20, 23, 25, and 26 show sealing means for the ejector pin and tilted core pin using load-type O-rings and concave O-rings, but as the gas pressure increases, a tighter seal is required. To improve the sealing effect (sealing performance), it is recommended to use a backup ring (reference number 200) as shown in Figure 46. Reference number 201 is a load-type O-ring, and reference number 202 is a spacer for adjusting the thickness. Figure 47 is an assembly diagram showing the combination of the load-type O-ring reference number 201, the backup ring reference number 200, and the spacer reference number 202. This combination further enhances the sealing effect and ensures sufficient sealing of high-pressure gas. (Figure 48) A photograph showing the combination of the various parts in Figure 47. Figure 48 is a schematic diagram showing the means by which the load-type O-ring 201 is assembled into a mold to achieve a seal. Reference number 202 indicates an ejector pin and a tilted core pin. Reference number 203 indicates a mold or mold insert, and reference number 204 also indicates a mold or mold insert. (Figure 49) A schematic diagram showing the components in Figures 46 and 47 assembled into a mold and sealing the ejector pin, tilted core pin, etc. (Fig. 50) is a schematic diagram (shown in cross section) showing the shape of the connection between the conventional hopper and the heating barrel. It shows that the molding material is supplied into the heating barrel from directly above the screw. (Fig. 51) is a schematic diagram showing the shape of the connection between the hopper and the heating barrel, which allows for better penetration into the screw. The supply port 208 for the molding material into the heating barrel is eccentric (in Fig. 51 it is shifted significantly to the left).) and is supplied to the screw, allowing for easy penetration into the screw, and compression occurs by the final screw. (Figure 52) This is a schematic diagram showing the structure of a variable-volume container, which allows for volume control in gas-based foam molding, and allows for controlled volume injection of gas into the heating barrel relative to the molten resin inside. Note that this device is also suitable for injecting liquids into the heating barrel. (Figure 53) This is a schematic diagram of the screw showing the injection position of liquid and gas blowing agents. (Figure 54) This is a conceptual and schematic diagram of a box-shaped molded product. (Figure 55) This is a schematic diagram of the mold at the beginning of the core-back process to reduce the weight of the molded product. The movable mold, indicated by reference numeral 249, is shown moving forward. (Figure 56) This shows the cavity (molding space) 247 expanded by recessing reference numeral 249 in Figure 55. At this time, the ejector pin (250) is not retracted, forming a non-foamed skin layer (255) around the ejector pin. (Figure 57) Figure 55 shows that by retracting the ejector pin 250 with a delay after the retractions of the pins 249 and 252, ribs are formed inside the molded product by the ejector pin 250, thereby increasing the strength of the molded product. (Figure 58) High-pressure gas is injected into the molded product from the nozzle 251, forming a hollow space 257. The molded product shown in Figure 58 has both a foamed layer 252 and a hollow space 257. (Figure 59) Photograph of a rich foam molded product. (Figures 60) (A) to (D) are diagrams showing typical injection patterns for pouring liquids into a mold. (Figure 61) Schematic diagram showing a method for creating a negative pressure inside the mold by attaching an aspirator to the mold and using the exhaust process to remove pressurized air from the mold. This reduces or eliminates short molds. (Figure 62) Schematic diagram of a sealing mold for GCP equipped with a quick exhaust valve. (Figure 63) Conceptual diagram explaining that finely divided gas can be introduced into the heating barrel from the beginning. The gas is made fine by the sintered metal. (Figure 64) Schematic diagram showing the injection port for injecting gas and / or liquid into the heating barrel as shown in Figure 63.(A) is the outer cylinder, (B) is the inner core that fixes the sintered part (C) inside (A), and gas and / or liquid can reach the sintered part (C) from 311 and be injected in a pre-dispersed state into the heating cylinder. Multiple intake ports in Figure 64(D) may be provided in the heating cylinder.

[0043] (Definition of terms) First, we will define the terms used in this invention. "Process" is a word that indicates the flow of work or a process, and one process consists of multiple tasks or procedures, and generally indicates a large framework. In other words, a process is a word that indicates the step-by-step division of the progress or procedures of something or work, and is the process of performing a series of tasks in order to achieve a certain goal. "Process" also has the meaning of the order and progress of work. The "work" in "process" indicates the work of creating something, and "course" indicates the path or route.

[0044] "Mold cavity" refers to the space filled with foamable and / or non-foamable resin in injection molding, block molding, or cast molding. "Inside the cavity" refers to the interior, space, or volume of the mold cavity. "Cavity" is synonymous with "mold space." In injection molding, when the first mold (generally the fixed mold) and the second mold (generally the movable mold) are mated, a space defined by the first and second molds is created. This space is the "cavity," which is filled with foamable and / or non-foamable resin, and is sometimes simply referred to as the "cavity." The extruding shaft primarily refers to the ejector pin installed in the second mold, but also includes the inclined pins and kicker pins of the slide core.

[0045] In addition to the injection molding exemplified above, the present invention can also be implemented in sheet extrusion molding, profile extrusion molding, blow molding, and the like, depending on the die used.

[0046] "Injection" refers to the filling, injection, or process of foamable and / or non-foamable resins into a mold cavity. "Extrusion" refers to the continuous extrusion molding of heated and molten foamable and / or non-foamable resins through a die. This includes methods such as mixing non-foamable and foamable resins in the extruder nozzle to impart foamability, and also methods such as the Shinbo method, in which a liquid, and optionally a gas, is mixed with heated and molten resin in the extruder nozzle to impart foamability. Of course, the Shinbo method is also an effective method for injection foam molding.

[0047] "Blow molding" refers to the technique of placing a parison in a mold and pressurizing it with air or other gases from inside the parison to form the shape. If the parison is made of foam resin, this is blow molding using foam resin.

[0048] "Filling" refers to filling a mold cavity with foamable and / or non-foamable resin in processes such as injection molding and block molding. Filling an amount less than the volume of the mold cavity is called a short shot or short mold, filling an equivalent amount is called a full shot or full pack, and filling an amount greater than the volume is called an overshot or overpack. This invention explicitly states that holding pressure is used when applying holding pressure to the resin from the molding machine heater barrel after a full shot to reduce sink marks or improve transferability (UP). In block molding, the distinction between non-pressurized and pressurized is made clear, such as "no pressure after filling" and "pressurized after filling." "Pressurization" refers to applying a fluid pressurized above atmospheric pressure to the resin.

[0049] "Resin inside the heating cylinder" refers to thermoplastic resin in a solid (solid) state such as pellets, bulk, or powder before heating and melting, in the middle of plasticization, or in a molten state after plasticization is complete.

[0050] The properties of "foaming agents" can be gas, liquid, or solid, and are broadly classified into physical foaming agents and chemical foaming agents, each of which can be inorganic or organic. Gases include nitrogen gas, carbon dioxide (CO2), and ２Examples of suitable blowing agents include inert gases such as rare gases (helium, argon), and flammable gases such as hydrogen, which are used alone or as mixed gases (mixed fluids). Liquid blowing agents are substances that are liquid at NTP (Natural Temperature Pressure, Natural Temperature and Pressure, Normal Temperature Pressure, Normal Temperature and Pressure = a temperature of 23°C and a pressure of 1 atmosphere (1 atm, 760 mmHg)), and include monohydric alcohols such as ethanol (EtOH) and propanol (mainly isopropanol, iso-PrOH in this invention), dihydric or higher alcohols, ethers, esters, ketones, etc., vaporizable substances such as distilled water, ion-exchanged water, city water (tap water), and well water, sodium bicarbonate water and sodium citrate water using these substances as solvents, and liquefied carbon dioxide (liquid carbon dioxide) liquefied by pressurization and cooling. Solid inorganic thermal decomposition-type chemical blowing agents include bicarbonates, carbonates, nitrites, hydrogen compounds, carboxylic acids, and carboxylates. Microballoons (macroballoons, microballoons) such as Advancell (trade name), copper sulfate containing structural water (copper sulfate pentahydrate, now called "hydrate" rather than "water of crystallization"), of course, 5 moles of structural water also vaporize in the heating tube at the temperature of the heating tube and the temperature of the molten resin heated and melted, and the water vapor acts as a foaming gas. Other examples include silica gel immersed in water to impregnate it, ABS immersed in water for a long period of time (e.g., six hours) and then centrifugally removed to impregnate the surface (ABS), and PC and PC-based resins (PC / ABS in this case) immersed in water to impregnate it. The water vaporizes in the heating tube and functions as a blowing agent, just like the structural water, and these can also be used as blowing agents. While these examples use water, organic solvents such as alcohol can also be used. Although it is an extreme example, rice soaked in water can also be used as a foaming agent. Of course, solid carbon dioxide (dry ice) is also a solid foaming agent.In the case of dry ice, when it is mixed with pellets and placed in a hopper, and then placed in the heating cylinder, the dry ice will immediately vaporize and the vaporized carbon dioxide will escape from the hopper, so a stopper (such as a back melter) should be placed in the hopper during plasticization and measurement to prevent the carbon dioxide from escaping. Alternatively, a preferred method is to drill a hole in the heating cylinder and use a mechanism such as a feed screw to measure the amount and steadily add a fixed amount to the molten resin.

[0051] As mentioned above, inorganic thermally decomposable blowing agents include bicarbonates and carbonates, such as sodium bicarbonate, potassium bicarbonate, and lithium bicarbonate (Li). Organic thermally decomposable blowing agents include azo compounds, hydrazine derivatives, semicarbazide compounds, azide compounds, nitroso compounds, and triazole compounds. Reactive blowing agents include isocyanate compounds. Examples include ADCA (azo di(di)carboxylic acid amide), HDCA (hydrodicarboxylic acid amide), azo dicarboxylate (BA salt of ADCA), BA salt of HDCA, DPT (dinitroso pentamethylenetetramine), OBSH (P-P'-oxybis(benzenesulfonylhydrazide)), and AIBN (azo bis isobutyronitrile). Details of blowing agents and foam molding are found in "Various Polymers and Foam Molding Technology," published by the Technical Information Association, August 1993. In the case of carbonates or bicarbonates (alkali metals or alkaline earth metals), an equivalent amount (neutralization reaction with basic carbonate or bicarbonate) of a weakly acidic substance such as citric acid or disodium hydrogen citrate may be used in combination.

[0052] When using a liquid as a blowing agent for thermoplastic resins, the optimal volume (vol.) for the weight (wt.) of the molded product is measured and injected into the thermoplastic resin in the heating barrel, either all at once or continuously. Depending on the temperature of the heating barrel and the interior of the heating barrel, the temperature of the molten thermoplastic resin in the heating barrel, and / or the nozzle temperature and / or the mold temperature, the liquid vaporizes, thermally decomposes, and / or undergoes a chemical reaction, or decomposes and / or undergoes a chemical reaction without the need for heat, generating a foaming gas useful for foam molding. The temperature of the injected liquid is room temperature, but it can be heated if necessary to shorten the time until vaporization. The liquid pressure can also be increased to a level higher than the pressure that can be injected into the heating barrel, raising the boiling point.

[0053] The generated gas is finely dispersed and / or pressurized and dissolved in the molten thermoplastic resin in the heating barrel using physical forces during the metering stage and during filling, and the thermoplastic resin in the heating barrel becomes a foamable thermoplastic resin. This can be filled into a mold cavity to produce a molded product with a foam structure. In other words, "foam molding" refers to the process of obtaining a foam structure by dispersing and / or dissolving (including pressurized dissolving) a foaming gas into the resin in the heating barrel to give it foamability, and then filling the resin into a mold. Note that in the case of extrusion, a die is used instead of a mold.

[0054] "Giving foamability to molten resin" refers to the process of dispersing large chunks of foaming gas (nitrogen gas) with the force of screw rotation, melting them under pressure with back pressure, and / or finely dispersing them in the molten resin. In the case of liquids, the process involves vaporization or thermal decomposition depending on the temperature inside the heating barrel and the temperature of the molten resin, generating foaming gas, which is then dispersed with the force of screw rotation and finely dispersing them in the molten resin under pressure with back pressure. In the case of solid blowing agents, the process involves dispersing the foaming gas generated by a chemical reaction with the force of screw rotation and finely dispersing them in the molten resin under pressure with back pressure. In the case of micro (macro, micro) balloons, the process also involves dispersing the generated foaming gas with the force of screw rotation and finely dispersing them in the molten resin under pressure with back pressure. A high screw torque and high rotation speed are desirable. Increasing the back pressure improves the mixing ability and dispersion of the foaming gas. This also includes cases where the nozzle has an inlet for gaseous foaming agent, an inlet for liquid foaming agent, or where foamable resin that has been heated and melted is mixed with non-foamable resin. If necessary, the screw may be equipped with a dull shank or similar.

[0055] The liquid injection port is preferably located between 2D (twice the screw diameter) and 6D (six times the screw diameter) from the tip of the screw, not including the screw head, but the liquid can also be injected at a distance of 2D or less, or even further back than 6D, to impart foamability to the molten resin in the heating barrel. Depending on the combination of resin and liquid, an injection port can be provided in the nozzle and the liquid can be injected during injection, causing the liquid to penetrate into the molten resin due to the injection pressure and impart foamability to the molten resin. In this case, it is advisable to provide a mixing nozzle or the like and introduce the liquid from the rear of the mixing nozzle (53rd embodiment).

[0056] "Foaming" refers to the process where the foaming gas is suppressed by external pressure, such as GCP (outer GCP), back pressure, injection pressure, etc. (compressed into the resin and finely dispersed to a small volume, or / and pressurized and dissolved), and the volume of the foaming gas in the resin increases, or / and the pressurized and dissolved foaming gas turns into a gas, when the external pressure is reduced or eliminated. "Foaming" also refers to the process where a foamable thermoplastic resin is extruded from a heating barrel and foams, or where a foaming gas is generated by the vaporization, thermal decomposition, or chemical reaction of a liquid or solid blowing agent.

[0057] "Foaming" refers to the process of finely dispersing and / or pressurizing and dissolving a foaming gas in a molten thermoplastic resin, then reducing the pressure to form foam cells inside and / or on the surface of the thermoplastic resin (the foam cells (bubbles) that appear on the surface are swirl marks). In the case of thermosetting resins, heating the foaming agent causes the agent to vaporize, thermally decompose, and undergo a chemical reaction, generating foaming gas, which then forms foam cells inside and / or on the surface of the thermosetting resin. Molded products with foam layers inside or outside due to foaming in this way are called foam molded products or foam structures.

[0058] "Foamable resin" refers to a thermoplastic resin or thermosetting resin in a molten state in which a foaming gas useful for foam molding has been finely dispersed and / or dissolved under pressure. In other words, "foamable resin" refers to a thermoplastic resin or thermosetting resin containing a gaseous, liquid, or solid foaming agent. In this specification, we use terms such as "molten foamable thermoplastic resin" and "foaming agent-containing thermoplastic resin or foaming agent-containing thermosetting resin" to accurately describe the state of the resin, such as whether it has foamability or contains a gaseous, liquid, or solid foaming agent. The foaming agent may be a combination of liquid and solid, a combination of gas and solid, or several types of gas alone. In the case of a liquid, a mixture of alcohol and water may also be used.

[0059] "Foam-molded products" refer to resin molded products that have discontinuous foam cells inside, formed by molding foamable thermoplastic resins or thermosetting resins. The average size of the foam cells is 5,000 μm (microns (μ), micrometers (μm)) or less. In the present invention, foam-molded products are also considered to be products in which hollow portions and foam cells are mixed in a hollow molding process using foamable resins.

[0060] "Combined use" also refers to using or combining something with another thing. For example, one molding process method can be effective, but it can also be used in combination with another method, which can produce a synergistic effect or improve one or both effects. Blowing agents can also be used in combination with several other types rather than using only one. Liquid, gaseous, and solid blowing agents can also be used in combination.

[0061] "Foaming aid" refers to a substance used to lower the decomposition temperature of a foaming agent or to accelerate its decomposition. Examples of foaming aids for organic foaming agents include zinc stearate, barium stearate, metal soap, urea (which has the effect of lowering the decomposition temperature of ADCA), and zinc oxide. Inorganic and organic acids (such as citric acid and sodium monohydrogen citrate) used to decompose carbonates and hydrogen carbonates can also be considered foaming aids. However, in the case of PC-based resins, there is a risk of decomposition, so it is important to check in advance whether the addition of each substance will reduce physical properties. In particular, basic oxides (another name for metal oxides) such as CaO, BaO, and Cs ２ O and the like have a high risk of decomposing the PC in PC-based resins.

[0062] (Foam nucleating agents and foam nucleating agents for PC resins) "Foam nucleating agents and foam nucleating agents" are substances mixed with the resin and foaming agent to be molded to form fine foam cells. Foam nucleating agents utilize the difference in specific heat between the molten resin and the foam nucleating agent to create small sinks (voids) at the boundary between the molten resin and the foam nucleating agent. Foaming begins at these sinks (the small spaces where foaming gases gather and begin to form), forming foam cells. In this way, foam nucleating agents utilize temperature differences (differences in specific heat, heating rates, cooling rates) (when the foam nucleating agent is heated, it may become warmer than the surrounding molten resin, or conversely, cooler) to create finer foam cells. Examples of foam nucleating agents include metal powders such as aluminum (Al), titanium (Ti), nickel (Ni), cobalt (Co), iron (Fe), copper (Cu), silver (Ag), tungsten (W), and chromium (Cr), non-metal powders such as silicon (Si) and germanium (Ge), and oxides, nitrides, and carbides of these metals.

[0063] In addition, flame retardants can also act as foam nucleating agents and provide the effect of foam nucleating agents. Halogen-based flame retardants, such as brominated epoxy, phosphate-based flame retardants, such as trimethyl phosphate, triethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, and cresyl di-2,6-xylenyl phosphate, non-halogen phosphate esters, such as non-halogen phosphate esters (DAIGUARD-1000 (trade name)), aromatic condensed phosphate esters (CR-7335 (trade name)), aromatic condensed phosphate esters (CR-741 (trade name)), and aromatic condensed phosphate esters (PX-200 (trade name)) are also used. Examples of suitable phosphate esters include non-halogen phosphate esters represented by {TMCPP (trade name)} and {CR-900 (trade name)}, halogen-containing phosphate esters represented by tris(chloropropyl)phosphate {TMCPP (trade name)} and tris(tribrimoneopentyl)phosphate {CR-900 (trade name)}, halogen-containing condensed phosphate esters represented by {CR-504L (trade name)}, {CR-570 (trade name)}, and {DAIGUARD-540 (trade name)}, and halogen-free condensed phosphate esters represented by {DAIGUARD-580 (trade name)}, {DAIGUARD-880 (trade name)}, and {DAIGUARD-850 (trade name)}.

[0064] In addition, fine particles of fluorine-containing resins such as polytetrafluoroethylene (tetrafluoride) (abbreviated as PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (abbreviated as PFA), tetrafluoroethylene-hexafluoropropylene copolymer (4.6-fluoride) (abbreviated as FEP), tetrafluoroethylene-ethylene copolymer (abbreviated as ETFE), polyvinylidene fluoride (difluoride) (abbreviated as PVDF), polychlorotrifluoroethylene (trifluoride) (abbreviated as PCTFE), and chlorotrifluoroethylene-ethylene copolymer (abbreviated as ECTFE), which are used in combination with the above flame retardants, also act as foam nucleating agents. Metal particles with nano-sized particles also act as foam nucleating agents.

[0065] For example, when water is used as a blowing agent, the foam cells of ABS are smaller than those of AS. When comparing PS and HIPS, the foam cells of HIPS are smaller than those of ABS, just like ABS. This is because the rubber (graft rubber) in the resin, which is a graft copolymer of acrylonitrile and styrene with butadiene, has a sea-island structure scattered like islands in a sea of ​​AS, and this graft rubber acts as a foam nucleating agent. It has been confirmed that the foam cells are smaller in PC / ABS than in PC alone. This is also because the specific heats of the two polymers are different, causing minute contractions at the interface and boundary regions, which results in the action and effect of the foam nucleating agent. The above foam nucleating agents can be used alone, or two or more types can be mixed as needed.

[0066] A foaming agent useful for foam molding PC resin is a gas, typically nitrogen gas or carbon dioxide, that is injected into the heating barrel during metering to impart foamability to the plasticized, melted molten resin in the heating barrel. Similarly to the gas, water is added to the heating barrel and vaporized by the heat (thermal energy, temperature) of the heating barrel and / or the heat (thermal energy, temperature) of the heated, melted molten resin, and then finely dispersed in the molten resin in the heating barrel to impart foamability. As mentioned above, foam nucleating agents can be used alone or in combination of two or more types.

[0067] In the case of PC resin, the foam nucleating agent acts as a catalyst to accelerate the decomposition of the PC resin, but the foam nucleating agent itself may decompose the PC resin. In particular, when water is used to foam PC resin, a substance that does not hydrolyze the PC resin is selected.

[0068] Useful foam nucleating agents for foam molding of PC resins include light diffusing agents such as silver oxide, aluminum oxide, silicon dioxide, and silicon carbide, which decompose PC without degrading its physical properties. After extensive research, the inventors have determined that the foam nucleating agent of the present invention preferably contains 40 to 60 parts by weight of aluminum oxide, 20 to 40 parts by weight of silver oxide, 1 to 10 parts by weight of silicon dioxide, and 1 to 10 parts by weight of silicon carbide. The particle size of components other than silver oxide is preferably 30 μm or less in order to be incorporated into the PC resin. Particle sizes exceeding 30 μm are undesirable because they cannot be uniformly dispersed in the resin and do not provide sufficient light diffusing properties. A particle size of 100 nm to 10 μm is more preferable. These components may be commercially available or may be synthesized to any particle size. Larger particle sizes may also be crushed. The synthesis method is not particularly limited.

[0069] Silver oxide is useful as a foam nucleating agent for PC resins, and Cu is used instead of silver oxide. ２ O, ZnO, Al ２ O ３ , MgO, TiO ２ , ZrO ２ , V ２ O ３ , V ２ O ５ , tungsten oxide, FeO, Fe ２ O ３ , manganese oxide, chromium oxide, cobalt oxide, nickel oxide, In oxide, indium (In) tin (Ti) oxide, germanium oxide, tin oxide, lead oxide, corundum, carborundum, Al ２ O ３ -MgO (spinel), WC (tungsten carbide), TiN (titanium nitride), and CrN (chromium nitride) are also promising.

[0070] On the other hand, carbonates such as calcium carbonate (Ca), magnesium carbonate (Mg), and barium carbonate (Ba), sulfates such as calcium sulfate and barium sulfate, and alkali metal salts of organic acids, especially monosodium citrate dihydrogen and monopotassium citrate dihydrogen, function as effective foam nucleating agents, but there are concerns about PC decomposition. Helical D (a calcium-containing inorganic filler manufactured by Shiraishi Calcium) also functions as a foam nucleating agent. The foaming aids mentioned above, such as zinc stearate, barium stearate, and metal soaps, also function as foam nucleating agents. Glass fiber, glass beads, carbon fiber, carbon powders such as Ketjen Black and acetylene black, and carbon nanotubes (CNTs) also function as foam nucleating agents. Metal powders are also effective. Nanomaterials from Adachi Shinsangyo Co., Ltd. also function as foam nucleating agents. Resin additives, such as pigments, also function as foam nucleating agents.

[0071] {Particle size (particle diameter) of foam nucleating agent} If the particle diameter of the foam nucleating agent is fine, it can be uniformly dispersed in the resin and the size of the foam cells can be made uniform. Although this varies depending on the foam nucleating agent used, it is generally 250 μm (micrometer, micron) or less, preferably 100 μm or less, and considering uniform dispersion, 50 μm or less is preferable. Even finer particles of about 100 nm (nanometer) to 10 μm are preferable.

[0072] (Use of foam nucleating agents) The foam nucleating agent used may be one type (single), or two or more types may be mixed (combined use). The particle size may also be the same, or even if a single type is used, different particle sizes may be used. In the case of multiple uses, the particle sizes of the foam nucleating agents may be the same or different.

[0073] (Masterbatch of Foam Nucleating Agent) Useful foam nucleating agents for foam molding of PC resins include metal oxides and metal carbides. These foam nucleating agents are mixed (dispersed) in the resin before use. Liquid foaming agents are mixed with the liquid. A high concentration (content of foam nucleating agent) can be prepared in pellets of the resin to be foamed and used as a masterbatch. When several types of foam nucleating agents are used, each individual foam nucleating agent (meaning a single substance in this context) can be prepared as a masterbatch, and then the masterbatch of each individual foam nucleating agent can be mixed with the pellets of the resin to be foamed. While masterbatches of foam nucleating agents can be prepared by heating and melt-kneading (e.g., melt-kneading using an extruder or pelletizing using a pelletizer), masterbatches of foam nucleating agents can also be prepared by applying the agent to the surface of the pellets of the resin to be foamed, as described in PCT / JP2020 / 15536.

[0074] The "mixing ratio" is expressed as the ratio of the weight (wt.) or volume (vol.) of the foam nucleating agent master batch to the weight or volume of the resin to be molded, assuming that the weight (wt.) or volume (vol.) of the foam nucleating agent master batch is 1. It is expressed as the proportion (weight ratio) of the foam nucleating agent master batch contained in the resin to be foam molded (generally expressed by weight). For example, it is 2 wt. (weight)% or 2 vol. (volume)% relative to the resin. It is expressed as 2:100 (or 1:50, or 1 / 50), or 2 wt.%, 2 vol.%, etc. Similarly, when a liquid foaming agent is used, it is expressed as the volume (vol.) relative to the weight (wt.) or volume of the resin.

[0075] (Amount of foam nucleating agent added) The amount of foam nucleating agent added can be within a range that does not affect the physical properties of the resin and allows for acceptable degradation of physical properties. The amount added varies depending on the resin to be foamed and the foaming gas used (for example, nitrogen gas or carbon dioxide gas may be used alone, or a composite gas may be formed by mixing various foaming gases such as nitrogen gas, carbon monoxide, carbon dioxide gas, and water vapor). The amount of foam nucleating agent added to the resin to be foamed is 0.001 to 10 parts by weight per 100 parts by weight of resin. If the amount of foam nucleating agent added is less than 0.001 part by weight, the particle size of the foam cells will be large. Conversely, adding too much foam nucleating agent results in finer foam cells and greater foaming power. Therefore, to eliminate the swirl marks that occur on the surface with GCP and obtain foam-molded products with a clean, smooth surface, the type and pressure of the gas used (the inventors chose air at a pressure of 1.4 MPa, considering economics and ease of foam molding) are generally changed. Increasing the GCP pressure can reduce swirl marks, and if carbon dioxide gas is used instead of air, the carbon dioxide gas dissolves into the leading edge of the foamable molten resin filled into the mold, reducing swirl marks. For reference, GCP using carbon dioxide gas produces a clean surface even with non-foaming resins. Composite materials such as glass fiber also have the effect of sinking the glass fiber.

[0076] [Polycarbonate Resin, Polycarbonate Ester {Polycarbonate (PC)}] The PC used in the present invention will be explained below. PC is a polycarbonate ester produced using bisphenol A and phosgene or di(di)phenyl carbonate as raw materials. When carbonyl chloride is used, it is polymerized by interfacial condensation polymerization. When diphenyl carbonate is used, it is synthesized by polymerization through ester exchange. There are no particular restrictions on the PC, and any known resin can be used. For example, a resin obtained by reacting an aromatic dihydroxy compound with phosgene or a carbonate diester by a melt method or solution method can be used. Representative examples of aromatic dihydroxy compounds include 2,2-bis(4-hydroxyphenyl)propane (bisphenol A), 1,1-bis(4-hydroxyphenyl)ethane, 1,1-bis(4-hydroxyphenyl)cyclohexane, 2,2-bis(4-hydroxy-3,5-dimethylphenyl)propane, 2,2-bis(4-hydroxy-3-methylphenyl)propane, bis(4-hydroxyphenyl)sulfide, and bis(4-hydroxyphenyl)sulfone. Among these, bisphenol A is particularly preferred and widely used. In the present invention, in addition to bisphenol A-based PC, which is a widely used PC, PCs produced using other dihydric phenols can also be used.

[0077] Furthermore, trivalent or higher phenolic compounds such as those shown below may be used in combination: Trivalent or higher phenolic compounds include phloroglucin, 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptene, 2,4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptane, 1,3,5-tri-(4-hydroxyphenyl)-benzene, 1,1,1-tri-(4-hydroxyphenyl)-ethane, and 2,2-bis-[4,4-(4,4-dihydroxydiphenyl)-cyclohexyl]-propane.

[0078] The viscosity average molecular weight of the PC used in the present invention is 1,000 to 100,000, more preferably 10,000 to 50,000. When producing such PC, a molecular weight modifier, catalyst, etc. can be used as needed. The PC resins may be used alone or in a suitable mixture of two or more types.

[0079] (Regarding the Production of PC Resin Compositions) The production method for the PC resin composition containing the foam nucleating agent of the present invention is not particularly limited. However, a preferred method for producing the resin composition of the present invention is to melt-knead the components using a multi-screw extruder such as a twin-screw extruder. A typical example of a twin-screw extruder is the ZSK (trade name, manufactured by Werner & Pfleiderer). Specific examples of similar types of extruders include the TEX (trade name, manufactured by The Japan Steel Works, Ltd.), TEM (trade name, manufactured by Toshiba Machine Co., Ltd.), and KTX (trade name, manufactured by Kobe Steel, Ltd.). Other examples of melt-kneaders include the FCM (trade name, manufactured by Farrel), Ko-Kneader (trade name, manufactured by Buss), and DSM (trade name, manufactured by Krauss-Maffei).

[0080] (Purpose and Meaning of Foaming PC Resins) PC is a resin whose impact strength is highly dependent on wall thickness. For example, the impact strength of solid (general, general) molded products with wall thicknesses of 5mm and 6mm is lower than that of ABS. However, reducing the wall thickness to 1mm or 2mm significantly increases impact strength. It has been confirmed that a 0.2mm layer of PC will not crack even under a large impact. Therefore, by using water as a foaming agent, which does not affect the physical properties of PC, foaming, creating an expanded core such as a mold back or core back, and increasing the expansion ratio to form thin-walled PC foam cells on the surface and inside, a PC foam structure with sufficient impact strength can be obtained. This is the purpose of foam molding PC and resins primarily composed of PC, as described in this invention. PC is often used in polymer alloys with other resins, such as ABS. In these cases, the PC forms a thin layer within the ABS, making it possible to use water as a foaming agent in foam molding of PC / ABS, PC / PS, PC / HIPS, etc.

[0081] (Method for increasing the expansion ratio of PC resins) Using water as the foaming agent, the resin is made foamable inside the heating barrel of the molding machine and filled into the cavity. After filling, the mold is retracted a predetermined distance (generally this means retracting the movable side of the mold. In other words, this means opening the PL a predetermined distance). The detailed process is shown below. The mold is closed and the foamable resin is filled into the cavity. Simultaneously with filling, or with a short delay after filling, the mold is opened a predetermined distance. At this time, the molded product expands due to the foaming force of the foamable resin. Separately, when a hollow interior (inner GCP) is created (in blow molding using foamable resins, where high-pressure nitrogen gas or similar is injected through the nozzle of the molding machine, or through the runner, or / and directly into the molded product, and a fluid (e.g., pressurized gas, pressurized liquid, heated steam, etc.) is injected), and the interior is expanded by the force of the fluid (e.g., pressurized gas, pressurized liquid, heated steam, etc.) (especially in the core-backs shown in Figures 11, 12, 13, and 14, the PL is a vertical parting line, so flash formation is minimal even when the mold is opened wide. However, when the expansion ratio is extremely increased to 2, 5, or 10 times, the foaming force alone is insufficient to transfer the material to the mold, and if the core-back is performed without any expansion, the molded product will separate from the mold.) As a result, mold reproducibility decreases. As a result, foam-molded products with high expansion ratios cannot be obtained. Foam molding using an outer GCP further reduces mold reproducibility, making it impossible to obtain foam-molded products with clean, smooth surfaces at high expansion ratios. To solve this problem, the inventors also performed blow molding (inner GCP) using a foamable resin and confirmed that sufficient mold reproducibility was achieved. They also confirmed that blow molding (inner GCP) using an outer GCP with a foamable resin, followed by mold backing and core backing, resulted in a foam-molded product with a clean surface and a smooth, high expansion ratio. After cooling and solidification, a pressurized fluid (also called a "high-pressure fluid" or "compressed fluid") is introduced into the molded product. Generally, a gas compressed above atmospheric pressure is used, but a liquid is also acceptable. Gases are primarily air, nitrogen, and carbon dioxide, either singly or in combination. Liquids are primarily water, but they can also be used at elevated temperatures, such as 40°C, 50°C, 90°C, and even 100°C, where the pressure is high enough to maintain the liquid state.When a foamed foam is injected, the pressurized fluid is vented, the pressure is lowered to a level where the internal pressure will not cause the foamed foam to expand or burst, and the mold is then opened to remove the foamed foam product. In a three-plate mold, if the PL is already opened a certain distance, the stripper plate will not open even if the PL is opened, and the spool runner will not be removed. Therefore, the mold must be equipped with a mechanism that opens the stripper plate after the PL is opened first. The software controlling the mold back and core back can be implemented using an external sequencer (PLC, a controller box using PLC) that exchanges signals with the molding machine. Alternatively, software that performs these operations can be added to the molding machine's built-in PLC (a PLC with programs written in it that control the mold opening / closing, injection, etc.).

[0082] The method for feeding the foam nucleating agent of the present invention and the PC resin to the extruder is not particularly limited, but the following methods are representative examples: (1) A method in which the foam nucleating agent of the present invention and the PC resin are fed independently into the extruder, and (2) A method in which the foam nucleating agent of the present invention and the PC resin additive are premixed using a mixer such as a super mixer, and then fed into the extruder.

[0083] The above method is not limiting; resins can also be produced by mixing a desired amount of foam nucleating agent with the raw PC material. The method for producing a PC resin composition is not limited in any way. The PC resin composition containing the foam nucleating agent of the present invention can also be used for foam molding in the form of various profile extrusion molded products, sheets, and films. It can also be molded into heat-shrinkable tubing by a specific stretching procedure. Molded products can also be produced by rotational molding or blow molding. Molded products can also be made from flame-retardant PC resin compositions (resins made flame-retardant by adding flame retardants or flame-retardant assistants) or resins with increased rigidity due to the addition of minerals such as glass fiber. These molded products can also be subjected to various surface treatments, such as painting and plating.

[0084] Among PC-based resins, polymer alloys and blends containing PC as the primary component include PC / PET (polyethylene terephthalate), PC / PBT (polybutylene terephthalate), PC / ABS (an acrylic-nitrile-styrene graft terpolymer in which acrylic-nitrile and styrene are graft copolymerized with butadiene) and AS (a copolymer of acrylic-nitrile and styrene), PC / AES, PC / AAS, PC / ASA, PC / PS (polystyrene), PC / PP (polypropylene, polymethylvinyl), PC / PE (polyethylene, polyvinyl hydrogen), PC / vinyl chloride (polyvinyl chloride, PVC), and PC / PPO. When foam molding these materials, the inherent properties of PC cannot be fully realized if the foam nucleating agent is not selected correctly. Water is a useful blowing agent for foam molding PC-based resins, but when PC-based polymer alloys and blends contain PET or PBT, ester-based resins such as PET decompose, significantly reducing their properties. Polyamide (PA) is virtually unaffected by hydrolysis.

[0085] "Compatibility" refers to the property of thermoplastic resins, whereby each resin mixes at the molecular level when heated and melted. For example, AS is compatible with ABS, and PPO (polyphenylene oxide) and PPE (polyphenylene ether) are compatible with PS (polystyrene) and HIPS (high impact polystyrene). In this invention, PPO and PPE are treated as the same substance and referred to as "PPO." PPO modified or modified (mixed to form a blend polymer or polymer alloy) with HIPS and / or PS, as well as PP, ABS, and PA, is called modified-PPO, modified-PPO, or m-PPO.

[0086] "Compatibility" refers to a situation where one resin is not miscible with the other, dispersing in the other, forming an island structure or other structure. For example, rubber B in ABS (a polymer (high molecular weight) in which butadiene rubber is graft-copolymerized with acrylonitrile (vinyl cyanide) and styrene (vinyl phenylate)) is compatible with AS. When they are miscible or compatible, there is little or no deterioration in physical properties.

[0087] {Compatibilizer} When producing polymer alloys and polymer blends such as PC / PET, PC / PBT, PC / AS, PC / ABS, PC / PS, and PC / HIPS, which have PC as the main component, a compatibilizer is used as needed. Examples of compatibilizers used in these applications include those sold by Nippon Oil & Fats. If the amount of compatibilizer added is small, the resin will not be sufficiently compatible (miscible), and the physical and chemical properties of the resin will not be fully exhibited. If too much is added, the physical properties will be significantly reduced, so it is desirable to add an amount that does not have much effect on the physical properties relative to the weight of the PC.

[0088] (Painting suitability) In the case of PC resin molded products, if the internal stress (internal strain) is high, the paint solvent (thinner) will cause microcracks, preventing the high impact strength of PC from being exhibited. In the foam molding of this invention, the molding is a cut-off molding without the use of dwell pressure as in injection molding, so there is little internal stress. Even if painting is applied as is, there is less deterioration in physical properties due to cracking than in molded products that are subjected to high dwell pressure and have high internal stress. If the product is further annealed for about two hours to remove the internal stress, the deterioration in physical properties (such as cracking) due to microcracks will be further reduced.

[0089] (Embodiment of Foam Molding of PC Resin) When foam molding of PC resin is carried out, as is clear from Comparative Example 1 (foaming agent used: sodium bicarbonate), Comparative Example 2 (foaming agent used: ADCA), and Comparative Example 3 (foaming agent used: ethanol) described later, the properties of PC (high impact strength = does not break easily) are not exhibited at all in foam molding of PC. However, as shown in Example 1, when the foaming agent is water (chemical name: hydrogen monoxide, dihydrogen monoxide, chemical formula: H ２ It was confirmed that the use of PEG-1000 resulted in minimal deterioration of the physical properties of PC.

[0090] (Outer GCP) Using water as the blowing agent, foam molding was performed by injecting water into the heating barrel of an injection molding machine through the liquid injection device and inlet on the heating barrel shown in Figures 1, 4, and 5 of PCT / JP2015 / 062611. Swirl marks due to the water blowing agent were observed on the surface of the foam-molded product. Using the nozzle shown in Figures 20 through 22 of PCT / JP2015 / 062611, the sealed mold for GCP shown in Figures 23 and 25, and the GCP device shown in Figure 24, GCP was performed with 1.4 MPa air. It was confirmed that foam-molded products with a clean, smooth skin layer and a fine foam layer inside were produced without swirl marks on the surface.

[0091] (Undercut Processing) When molded products have undercuts (protruding portions) as shown in Figures 17 and 18, mechanical slides using a slide core (external slide core method), tilted core method (tilted pin), hydraulics, pneumatics, rack and pinion, ball screws, etc. are used. In Figure 17, reference numeral 57 indicates the undercut portion, and the arrow reference numeral 58 indicates the slide direction. In this case, an angular pin is used, and by linking the opening and closing of the mold with the opening and closing of the slide, it is possible to process undercuts (processing molded products with undercut shapes). Since the amount of slide movement is determined by the angle of the angular pin, a new component such as a slide stopper may be added to prevent the slide from moving too far down. If the undercut portion indicated by reference numeral 57 (shown as a hole in Figure 17) is long, a slide core using hydraulics, etc. is used. Reference number 55 indicates the cross section of the product (cross section of the cavity), and 61 indicates the PL of the mold (the parting surface, parting portion, the surface where the movable side mold and the fixed side mold come together, the space defined by the joining of the fixed side mold and the movable side mold is the "cavity").

[0092] In the case of Figure 18, the undercut treatment of reference number 59 is mainly performed using the inclined core method. Reference number 60 indicates the direction of the slide. Reference number 56 indicates the cross section of the product, and reference number 61 is the PL of the mold.

[0093] (Sealing Mold) First, we will explain the structure of the sealing mold for GCP, which is an effective means of eliminating swirl marks on the surface during foam molding and achieving a smooth foam-molded product. There are two types of sealing mold structures: one in which the ejector mechanism is enclosed by a spacer block, and one in which each ejector pin is sealed with an L-shaped, U-shaped weighted O-ring, or a U-shaped (concave) O-ring. Figure 19 shows a sealing mold structure using an ejector box in which the spacer block (reference number 74) is an integrated structure resembling the Japanese katakana character "ロ" (ro), housing and sealing the ejector mechanism. Reference number 62 denotes a spool bushing, which is sealed with an O-ring reference number 64. Reference number 63 denotes a fixed (cabinet) side mounting plate, and an O-ring 65 is installed between it and the fixed side mold plate (reference number 104) to seal it. The fixed-side insert forms the cavity indicated by reference number 89, and reference number 61 is the PL, on which an O-ring indicated by reference number 69 is arranged (provided). Reference numbers 55 and 56 are cavities that are filled with molten resin. Reference number 70 is the movable (core) side mold plate, into which the insert indicated by reference number 92 is assembled. The insert is fixed with bolts (not shown) or the like. Pressurized air and pressurized fluid within the cavity also enter and exit through the gap (the mating surfaces) of the insert indicated by reference number 92. Reference number 87 is a backing plate. Reference number 72 is an O-ring that seals between the movable mold plate (reference number 70) and reference number 87, reference number 73 is an O-ring that seals the gap between reference number 87 and reference number 74 (a spacer block shaped like the Japanese katakana character "ロ" to enclose and seal the ejector mechanism), thereby completing the ejector box structure referenced 75 (a mold structure that encloses the ejector mechanism in space for sealing purposes). Because the ejector pins are sealed by the ejector box, individual seals for the ejector pins referenced 67 are not necessary. Reference number 76 is an ejector plate (top) that secures the ejector pins, and reference number 77 is an ejector plate (bottom) that secures the ejector pins. Reference number 80 is a movable mounting plate, and reference number 79 is an O-ring installed in the gap between reference number 80 and reference number 74.Reference numeral 82 denotes a hole in the ejector rod, and an O-ring indicated by reference numeral 81 is incorporated into the bottom of reference numeral 77 to seal when the mold is closed and the ejector plate is moved back by a return pin (not shown) or the like.

[0094] The O-rings designated 64, 65, 69, 72, 73, 79, and 81 are commercially available products made of materials such as NBR (nitrile butadiene rubber), silicone rubber, and urethane rubber. These O-rings are used by carving grooves into which they are fitted, but there is a risk that the surfaces securing the O-rings 69 and 81 will separate when the mold is opened and the molded product is extruded, causing the O-rings to come out of the grooves. Therefore, the inventors used a tapered end mill to create dovetail grooves (shapes in which the top is narrower than the bottom in cross section) for the grooves 69 and 81, so that the O-rings will not come out of the groove even if the plates separate.

[0095] Next, we will explain the gas circuit for pressurizing the inside of the mold {mainly air compressed to atmospheric pressure or higher is used, but in some cases nitrogen gas, carbon dioxide gas, or a mixture of these gases is used.} Reference numeral 88 is a circuit that introduces compressed air (gas, pressurized fluid in a broad sense) into the bottom of the fixed side insert, and pressurizes the inside of cavities 55 and 56 from the gap (not shown) between the fixed side insert (reference numeral 89) and reference numeral 104 (fixed side mold plate), and the inventors have called this L ３ This is called "pressurized air into the cavity from the fixed side." During filling of the cavity with foamable or non-foamable resin, after filling is complete, and after a certain time has passed since filling is complete, the pressurized air inside the mold is released into the atmosphere through the same circuit. The arrow with reference number 66 indicates the flow of pressurized air inside the mold, and in order to show that pressurization and release of air inside the mold are carried out using the same circuit, both the beginning (start point) and the end (end point) are shown as arrows. Reference number 90 is a circuit that pressurizes air from PL to cavity 55 and reference number 56, and reference number 91 indicates the flow direction of the pressurized fluid (for example, gas). Reference numbers 90 and 91 are L ２The reference numeral 95 is a compressed air fluid (gas) circuit that pressurizes the cavity from PL and exhausts the air. A hole is made in the reference numeral 74, and the reference numeral 96 is a compressed air fluid (gas) circuit that pressurizes the inside of the ejector box of the reference numeral 75 and exhausts the air. The reference numeral 96 is an arrow (L) that shows the flow of compressed air fluid (gas) inside the ejector box. ３ As with the above, the start and end points are also indicated by arrows. When the inside of the ejector box is pressurized, the gas (compressed air) inside the ejector box pressurizes the inside of the cavity (reference numbers 55 and 56) through the gaps of the ejector pins and the gaps of the insert. In the present invention, this is called L １ When the ejector box is evacuated after the molten resin is filled, the pressure inside the ejector box decreases, and as a result, the pressure inside the cavity decreases.

[0096] The ejector box structure provides a simple sealing method and a high sealing effect, but the ejector box is larger in volume than the cavity, and a large amount of pressurized air is required to pressurize a mold sealed with the ejector box structure. Moreover, it takes time to pressurize the mold, which results in economic problems such as the extra cost of air required for pressurization and the extra time required for pressurization, resulting in a longer molding cycle.

[0097] Figure 20 explains a means for sealing the ejector pin that solves the problem in Figure 19. The difference between Figure 19 and Figure 20 is that reference numeral 74 is a square-shaped element that encloses the ejector mechanism, but the ejector pin is sealed with a weighted O-ring reference numeral 103, so the spacer block reference numeral 105 can be of a normal shape. As a result, the O-rings reference numerals 79 and 81 are not necessary. Reference numeral 93 pressurizes the cavities 55 and 56 through the gap between the bottom of the movable insert and the ejector pin. Reference numeral 94 is an arrow indicating the flow of compressed air and exhaust fluid (gas), and is the same as the arrow in Figure 19. １19 and 20. Reference number 101 is the seal plate into which reference number 103 is fitted and fixed. A groove may be dug directly into the seal plate 101 and reference number 103 may be embedded, or the seal may be nested in order to embed reference number 103. For the seal of the inclined pin shown in Figure 24, the weighted O-ring reference number 103 must be aligned with the axis of the inclined pin and installed parallel to it, so it is better to use a nested O-ring. Reference number 102 is the O-ring fitted into the gap between the receiving plate 87 and the seal plate 101. Although the movable side is significantly different, the differences between Figures 19 and 20 are not significant for the seals on the PL and fixed sides.

[0098] Figure 21 shows the mold structure when processing the undercut shape of reference number 57 shown in Figure 17 with a slide core. Reference number 69 is an O-ring of PL, and reference number 97 is a guide pin or guide post provided on the outside of reference number 69. Reference number 98 is a fluid (gas) circuit provided in PL to pressurize the insides of reference numbers 55 and 56, and reference number 184 is a circuit of reference number 90L. ２ This is the port that blows out compressed air from the compressed air circuit, and as shown in Figure 22, it is connected to reference number 98 and also to reference number 90. Reference number 99 is an arrow indicating the flow of compressed air and exhaust air of reference number 98. Reference number 68 is the slide core, and reference number 78 is the hole into which the angular pin fits. The slide core of reference number 68 cannot be sealed unless it is placed inside the PL O-ring of reference number 69. The mating surface of the slide (PL surface of the slide) also needs to be sealed with an O-ring (not shown) on the outside of the product shape, just like reference number 69. Figure 21 is a view looking into the cavity of Figures 19 and 20 from the front.

[0099] FIG. 22 is a cross-sectional view of the cavity of FIGS. 19 and 20, and reference numeral 184 denotes L ２ Circuit, reference number 98 is the L provided on the PL of the mold ２The inventors have set the cross-sectional shape of the fluid (gas) circuit (groove) to, for example, a width (width, width, or width) of approximately 5 mm to 10 mm and a depth of approximately 1 mm to 3 mm. Reference numeral 100 denotes a vent, which is a circuit for pressurizing and exhausting air to cavities 55 and 56. It is not provided around the entire circumference, but is provided at regular intervals (20 mm to 50 mm pitch intervals) like a comb. The width is approximately 5 mm to 10 mm, and the depth varies depending on the molten resin. For highly fluid resins such as PP, the depth is approximately 0.03 mm in consideration of the risk of burrs, and for ABS, the depth is approximately 0.05 mm to 0.1 mm. For modified PPO and PC, which do not have high fluidity, the risk of burrs is low, so a depth of 0.1 mm or more is acceptable.

[0100] Figure 23 shows a means (mold structure) for treating the undercut indicated by reference numeral 59. A tilted core is used for this type of shape. Reference numeral 107 is the tilted core. The movable side, including the movable side mold plate indicated by reference numeral 70, retracts, and the PL indicated by reference numeral 61 opens. When the ejector rod (not shown) installed in the molding machine is pushed forward, the ejector plate (ejector plate) composed of reference numerals 77 and 78 is pushed forward, and the ejector pin indicated by reference numeral 70 and the shaft indicated by reference numeral 108 are also pushed out as shown by the arrows (reference numerals 109 and 110). As a result, the resin filled within reference numeral 56 (the molded product after cooling and solidification) is pushed out. The tilted core indicated by reference numeral 107 moves in the direction indicated by the arrow indicated by reference numeral 111 (perpendicular to the mold opening and closing direction in Figure 23). The molded product moves relative to the inclined core 107 as indicated by reference numeral 112, and the undercut indicated by reference numeral 59 comes out of the mold, allowing the molded product to be removed. In Figure 23, the load type O-rings 103 and 106 are arranged facing the cavity, but if they are arranged in the opposite direction, a mold structure can be created in which the cavity is vacuumed (meaning reduced pressure below atmospheric pressure) and molding is performed.

[0101] Figure 24 shows that when there are multiple inclined cores that cross each other closely, it is difficult for the weighted O-ring to seal sufficiently with just one seal plate. In this case, sealing is possible by using multiple seal plates (Figure 24 shows the use of two plates, reference numbers 101 and 116).

[0102] In outer GCP, the inside of the mold (cavity, molding space) is "pressurized" or "gas-pressurized." "GCP pressurizing," "GCP gas pressurization," and "applying GCP" are synonyms for using gas to increase the pressure inside the mold before filling it with molten resin. Also, "exhaust." "GCP exhaust" is a synonym for venting the gas that pressurized the inside of the mold to the atmosphere during or after filling with molten resin, reducing the pressure inside the mold and causing foaming. Vacuuming can also be used.

[0103] (Blow Molding) When using a pressurized fluid injection pin (Figure 29) consisting of an ejector pin (Figure 27) and an ejector sleeve pin (Figure 28) to perform blow molding of non-foaming resins, one issue is the speed at which the pressurized fluid inside the molded product is exhausted. Since the injection is initially at high pressure and is injected into the molten resin inside the cavity, the injection pressure is constant and the injection speed is not a significant issue. For exhaust, the pressurized fluid inside the hollow must be exhausted to reference number 122 through a narrow gap (approximately 0.01 mm to 0.08 mm) as shown in Figures 27, 28, and 29. As the exhaust progresses, the pressure inside the hollow in the molded product decreases, making exhaust more difficult and slowing down the exhaust speed. If the pressurized fluid inside the hollow is not fully exhausted when the mold is opened, the residual pressure inside the hollow can cause the molded product to swell or burst. This issue is addressed using a mold with an ejector plate (B) consisting of reference numbers 117 and 118, as shown in Figure 25. Before the resin is filled, the ejector plate (B) is advanced by a stepped ejector rod, and non-foaming and foaming resins are filled. During and after the resin is filled, pressurized fluid is introduced through reference number 121, and the molded product is hollowed out through the pressurized fluid injection pin at reference number 120 (assembled in Figures 27 and 28). After hollowing, the exhaust valve of the blow molding device is opened to vent the pressurized fluid that had been introduced into the hollow. Once the pressure has dropped, the ejector plate (B) is moved back (by lowering the ejector rod). The ejector plate (B) is equipped with springs, gas springs, etc., so that when the ejector rod is lowered, the force of the springs, etc., forces the ejector plate (B) down.}, the tip of the pressurized fluid injection pin 120 separates from the boss 123 (provided for the purpose of directing the pressurized fluid into the molten resin) that surrounds the tip of the pressurized fluid injection pin of the molded product, creating a space, which is then exhausted all at once. In Figure 25, the ejector pin 67 penetrates the ejector plate (B).

[0104] This method is effective for foam-molded products with high expansion ratios using foamable resins and for thermoplastic elastomers with low resin rigidity. When molding foams with expansion ratios of 2x, 3x, 5x, or even higher, the cavity is filled with foamable resin that has been given foamability using a liquid, gas, or solid blowing agent (either alone or in combination), creating a hollow interior. While maintaining pressure in the hollow, the mold is backed up and cored back, the pressurized fluid in the hollow is evacuated, and the pressurized fluid pressure pin is retracted (retracting the ejector plate (B)). This rapidly reduces the pressure inside the hollow, causing foaming to begin inward. In the case of mold-backing, as shown in Figures 11 and 12, the expansion ratio must be around 2x to avoid the risk of flashing. In the case of core-backing, as shown in Figures 13 and 14, there is no risk of flashing. An outer GCP may also be used.

[0105] (Method for Avoiding Problems Such as Blisters and Bursts During Blow Molding) After the cavity begins to be filled with molten resin (the injection start signal is output), the injection valve of the blow molding machine is opened during filling, immediately after filling is complete, or after a predetermined delay time has elapsed, to initiate hollowing of the molten resin. After the predetermined injection valve opening time (referred to as the "injection time" in this specification) is completed, the pressurized fluid is trapped within the hollow. This is referred to as the "hold time" in this specification. After the hold time is completed, the exhaust valve of the blow molding machine is opened, and the pressurized fluid within the hollow is vented to the atmosphere. After a timer triggered by the start of exhaust expires, the ejector plate (B) is retracted until bulging or bursting due to the pressurized fluid within the hollow no longer occurs. After cooling and solidification are complete, the mold is opened and the molded product is removed. The mold shown in Figure 25 shows a sealed mold conforming to GCP specifications. However, sealing is not required when using non-foaming resins, and sealing of the PL, etc. is not required, as shown in Figure 36. Of course, if the mold of FIG. 25 is used without using GCP, the mold function will be the same as that of FIG.

[0106] (Pressure molding) Mold-back and core-back operations separate the resin from the mold at this stage, reducing mold reproducibility. Therefore, internal pressure (by blow molding) is applied to ensure sufficient contact with the mold, allowing mold-back and core-back operations. Alternatively, a pressurized fluid is introduced into the gap between the molten resin and the mold, applying pressure to the surface opposite the fluid pressure application surface, resulting in molded products using non-foamable or foamable resins with high mold reproducibility. It is also possible to combine blow molding and pressure molding. In this case, the pressure of the pressurized fluid used to form the blow molding (referred to as "H pressure" in this invention) and the pressure of the pressurized fluid used to perform the pressure molding (referred to as "P pressure" in this invention) may be greater than H pressure, equal to H pressure, or less than H pressure, resulting in different hollow portions. The combined use of blow molding and pressure molding allows for control of the hollow portion size in PP hollow molded products, which was previously difficult using blow molding alone.

[0107] (Mold Structure for Pressure Forming) Figure 26 shows the mold structure used for pressure forming. Reference numeral 125 denotes a pressurized fluid pressure pin (Figure 32), which is made by additional processing of the ejector pin (Figure 30) and ejector sleeve (Figure 31). Because the pressurized fluid pressure pin requires high pressure, it is placed between the ejectors. It is anticipated that the strength of the ejectors and the bolts assembling the ejector plate will be compromised if pressurized fluid is introduced. Therefore, the inventors added a plate at 133 to the movable side mounting plate at 80, which is held down by the molding machine's die plate (not shown) and spacer block 105 to provide sufficient strength to secure the plate, ensuring it can withstand the pressure of the pressurized fluid. Reference numeral 127 denotes a load-type O-ring that seals the gap between 125 and 127. Reference numeral 128 denotes a seal plate used to install (fix) 127. If necessary, an O-ring at 102 is installed between 87 and 101. Item 126 (also an additionally processed ejector sleeve) is placed between the upper ejector plate 129 and the lower ejector plate 130. The ejector plate (C) consisting of items 129 and 130 moves with the ejector rod, as shown by the arrow at item 130. Before the resin is filled, the ejector plate (C) is in the forward position. When the resin is filled into the spaces between items 55 and 56, and the ejector plate (C) is retracted immediately after filling is complete, or after a short delay, item 126 also retracts, creating a small space at item 135. Pressurized fluid is introduced into this space from item 132. The pressurized fluid passes through the gap between the outer cylinder and core (inner core) at item 125, reaches item 135, and enters the gap between the resin and the mold, pressurizing the resin with the pressure of the pressurized fluid. The ejector plate (C) is retracted as described above to create a space, disperse the pressure, and fill the resin to prevent it from becoming hollow. If the pressure molding does not result in a hollow, this mechanism does not need to be installed. Although not shown, the tip of reference number 135, and if necessary, the surrounding area, on the surface where the pressure is applied, can be embossed to prevent the resin from becoming hollow and to allow the embossing to penetrate into the gap between the resin and the mold, creating a wedge effect. The pressurized fluid equipment used for pressure molding can be the same as that used for blow molding (the same equipment can be used for both blow molding and pressure molding).If this device is used in a compression zone of the heating barrel instead of in a mold and pressurized (the pressure should be higher than the pressure of the molten resin inside the heating barrel) nitrogen gas or carbon dioxide gas is introduced, it is easy to implement MUSEL (product name?) or AMOTEC (product name?), and in this case the program can also be written into the PLC of the molding machine.

[0108] (Mold-back, Core-back, Outer GCP, Inner GCP) In this invention, the GCP shown in Figure 26, which uses a sealed mold to pre-pressurize the mold, is referred to as an outer GCP, and blow molding using a foamable resin is referred to as an inner GCP. Using an inner GCP, core-back (which is difficult to achieve with mold-back due to issues such as flash and leakage of the pressurized fluid) allows for greater cavity expansion and results in a foam-molded product with a higher expansion ratio than mold-back. When mold-back or core-back is performed using an inner GCP, mold-back or core-back begins simultaneously with the start of pressurized fluid injection into the molten resin, after the injection has begun and a certain time has elapsed, when the injection valve is closed and the hold time of the blow molding program (in this case, the inner GCP) has arrived, during the hold time, or when the hold time is completed and the exhaust valve is opened and exhaust begins.

[0109] (GCP) By programming the blow molding, mold back, and core back with GCP, it is possible to create a foam molded product with a clean, smooth surface free of swirl marks and a high expansion ratio. The GCP issues a command to the GCP device that the mold is closed, and pressurizes the inside of the mold (the entire mold including the cavity, in a sealed mold such as that shown in Figure 25). In this pressurized state, the foamable resin that has been given foaming properties is filled into the cavity. During filling, immediately after filling is complete, or after filling is complete, the pressure valve of the GCP device is closed and the exhaust valve is opened to release the compressed air from inside the mold.

[0110] A separate controller (with a built-in PLC) is used for the molding programs that operate the blow molding, pressure molding, mold bag, core bag, and GCP devices, and this receives command signals from the molding machine and sends them to the controller. It's also common for the controller to output signals to the molding machine, and for them to exchange signals with each other (meaning they operate on each other's signals), but since the molding machine already has a PLC (sequencer), the PLC can be programmed to send a metering start signal to the blow molding, pressure molding, GCP, mold bag, core bag, and, if a liquid blowing agent is used, the liquid injection device to start injection into the heating barrel, stop liquid injection when the injection time is up or when metering is complete, set a liquid injection position during metering, start liquid injection when the screw passes that position, and stop liquid injection when the screw passes a preset liquid injection stop position, eliminating the need for troublesome signal reception or external controllers. Nitrogen sealing inside the hopper (a means of injecting nitrogen gas into the hopper to prevent discoloration and burning) can also be done by writing a program that starts injecting nitrogen gas into the hopper when measurement starts and stops the nitrogen gas when measurement stops. Nitrogen gas can also be continuously injected into the hopper by switching a switch on the molding machine screen. It is also possible to perform intermittent injection in relation to measurement, such as starting nitrogen sealing when measurement starts and sealing with nitrogen gas when measurement is complete.

[0111] The molding method using pressurized fluids, such as the pressurized gas and pressurized liquid described in this invention, can be used to control GCP devices, blow molding devices, pressure molding devices, liquid injection devices, etc. by writing each program into a PLC (sequencer) in the control panel of the molding machine to operate each device, or by writing a program into a PLC in a separate external controller to operate these devices, exchanging signals between molding machines, and operating these devices. Each case will be explained in detail below.

[0112] (Injection of Liquid, and Gas as Optional) (When Writing to the Molding Machine's PLC) The molding machine software for injecting gas and / or liquid into the heating barrel to impart foamability to the molten resin during the plasticization stage will now be described. The program written into the molding machine's PLC software first opens the valve (reference numeral 161) of an external liquid and / or gas injector (Figure 35) at a certain time after metering begins (the delay time can be set as desired) and injects the liquid into, for example, the initial location in the compression zone of the molding machine's heating barrel. The liquid vaporizes at the temperature of the heating barrel and the temperature of the molten resin. It is pressurized and dissolved and finely dispersed in the molten resin within the heating barrel by the back pressure during metering and the pressure applied to the molten resin within the heating barrel. Gas (nitrogen gas, carbon dioxide, etc.) is pressurized and finely dispersed in the molten resin.

[0113] Injection can be stopped when the screw passes a preset position. Alternatively, the start time for injection can be determined in advance, and the start of injection can be treated as a zero start, with injection stopping when the time is up (end). The injection amount can be constant, but if the screw rotation speed changes, the amount of resin plasticized will naturally change, so the injection amount (plunger pump discharge amount) can be synchronized with the screw rotation speed as needed.

[0114] (In the case of an external controller) When an external controller is used instead of writing a program for injecting gas and / or liquid into the molding machine's PLC, signals are exchanged between the molding machine and the controller. The injection molding machine sends a signal to the external controller to indicate that metering has begun. The controller, upon receiving the signal, arbitrarily sets a fixed delay time starting from 0 seconds, and when the time is up, begins injecting gas and / or liquid into the heating barrel. When the screw passes a stop position arbitrarily set on the molding machine, it outputs a signal to the controller, and upon receiving this signal, the controller stops injecting gas and / or liquid. This stop signal resets the program.

[0115] Injection control by time control, the controller receives a signal to start injection and has a timer that can be set arbitrarily, sets the desired injection time, and stops injection when the injection time is up.Synchronization with the screw rotation speed outputs the screw rotation speed as a continuous signal to the controller, and the controller receives this signal and controls the gas and / or liquid injection device to change the injection amount.

[0116] In the case of liquids, which are incompressible substances (volume changes little due to pressure), the injection amount can be easily controlled by changing the speed at which the plunger pump piston is pushed, for example, the rotation speed of a rack and pinion mechanism motor or servo motor, while in the case of gases, which are compressible substances (volume changes much due to pressure), the injection amount is controlled using an automatically opening and closing needle valve, etc. Multiple injection machines may be used, and the controller is installed with a program for each injection machine so that it can receive signal input and output from the molding machine.

[0117] (Pressurized air in GCP) (When writing to the molding machine's PLC) Figure 34 is a schematic diagram showing an overview of GCP measures. Reference number 151 is the pressurized air valve, and reference number 154 is the exhaust valve. When writing a GCP program to the molding machine, reference number 151 is opened after an arbitrarily set time has elapsed from 0 seconds upon receiving a mold clamping completion signal, and the inside of the seal mold is pressurized (pre-pressurized) to a pressure above atmospheric pressure. An arbitrarily set timer is used to determine the time for pressurizing the inside of the mold, and once the time is up, the molding machine will begin filling the cavity with foamable or non-foamable resin. The compressed air inside the mold is measured using a pressure sensor, and filling may begin when the preset pressure is reached.

[0118] (Air Compression by GCP) (In the Case of an External Controller) When the GCP device shown in Figure 34 is controlled using an external controller without writing a GCP program into the molding machine's PLC, the molding machine outputs a mold clamping completion signal to the external controller. Upon receiving this signal, the controller opens reference number 151 in the GCP device and pressurizes the mold. After the predetermined time for pressurizing the mold has elapsed, the controller outputs an injection start signal to the molding machine, which, upon receiving this signal, begins filling the cavity with molten resin. Alternatively, if the controller confirms that a pressure sensor installed in the mold that monitors the compressed air pressure has reached a preset pressure, the controller outputs an injection start signal to the molding machine, which, upon receiving this signal, begins filling the molding machine.

[0119] (GCP exhaust) (When writing to the PLC of the molding machine) The compressed air inside the mold can be exhausted during filling (at any position of the screw), after filling is complete, or after a certain time has passed after filling is complete. In the case of a molding machine, the exhaust valve 154 is opened to exhaust the compressed air inside the mold after the screw position in the PLC or after a time set arbitrarily from 0 seconds has passed.

[0120] (GCP exhaust) (In the case of an external controller) When exhausting using a separate external controller rather than the PLC inside the molding machine, the molding machine outputs an exhaust signal to the controller. For exhaust during filling, an exhaust signal is output to the controller when the screw passes a position that has been arbitrarily set, and for exhausting after injection is complete, an injection completion (primary pressure completion or secondary pressure completion) signal is output. Upon receiving this signal, the controller starts an internal timer, and after an arbitrarily set time has elapsed from 0 seconds, the exhaust valve 154 is opened and exhaust is performed.

[0121] {Mold back, core back (mold retraction)} (When writing to the molding machine's PLC) The mold (mainly the movable mold) is retracted a specified distance either at the start of compressed air exhaust, during exhaustion, or after a specified time has elapsed from 0 seconds after exhaustion is complete, thereby increasing the foaming ratio. When using the molding machine's PLC, this is performed either at the start of selected exhaustion, during exhaustion, or after a specified time has elapsed from 0 seconds after exhaustion is complete. When operating by pressure, the mold begins to retract when the pressure gauge installed on the mold reaches the preset pressure (the set exhaust pressure).

[0122] {Mold back, core back (mold retraction)} (When using an external controller) When an external controller is used, once exhaust starts, a mold retraction signal is sent to the molding machine, causing the mold to retract (mold retraction at the same time as exhaust starts). Alternatively, a timer starts when exhaust starts, and once the timer is up, a mold retraction signal is sent to the molding machine, causing the mold to retract (mold retraction during exhaust). In some cases, a timer starts when the controller starts exhaust, and once exhaust is sufficiently complete, a mold retraction signal is sent to the molding machine, causing the mold to retract (mold retraction after exhaust is complete). It is also possible to have a timer in the molding machine PLC rather than in the controller. In this case, a signal to start the exhaust timer is output. To monitor the pressure and retract the mold, a mold retraction signal is sent to the molding machine when the air pressure drops to the set pressure, and the mold retracts after a set time has elapsed, starting from 0 seconds, after receiving that signal.

[0123] Although the example shows a case where one program controls the GCP device, multiple programs (L １ , L ２ , L ３ :L １ = Space under the movable insert, or space in the ejector box, etc., L ２ = cavity, L ３ (= space under the fixed side insert) When using the same number of units, prepare the program for pressurizing and exhausting the air inside the mold, whether it is the PLC of the molding machine or the controller. １ , L ２ , L ３When using a pressure gauge to pressurize and exhaust, the pressure is mainly the cavity pressure, but other pressures are also acceptable. Note that mold retraction is a means of increasing the cavity volume and increasing the foaming ratio.

[0124] (Pressurized Fluid Injection, Retention, and Exhaust in Blow Molding) (When Writing to the Molding Machine's PLC) Blow molding (including inner GCP) is a molding method using the device shown in Figure 35. During or after filling a cavity with foamable or non-foamable resin, a pressurized fluid injection pin (120) is used to inject gas (e.g., air, nitrogen, or carbon dioxide) at or above atmospheric pressure into the molten resin in the cavity, creating a hollow interior. Alternatively, a pressurized liquid (e.g., heated water) is injected to create a hollow interior. The blow molding program written into the molding machine's PLC can open the pressurized fluid injection valve (161) when the screw passes a pre-set position (pressurized fluid injection during filling or pressurized fluid injection during filling), or immediately after filling is complete or after a preset time has elapsed from 0 seconds (pressurized fluid injection after filling is complete). The injection pressure is set using a regulator (165). The injection time can be set as desired (called the "injection time"). After the injection time is complete, the injection valve 161 closes, and the time for confining the pressurized fluid inside the mold (called the "retention time") can be set as desired. After the retention time is complete, the exhaust valve 163 is opened and the pressurized fluid inside the hollow is vented to the atmosphere. The pressure of the pressurized fluid is rarely varied during blow molding, but in cases where a profile of the pressure of the pressurized fluid to be injected is created, for example by initially injecting at high pressure, then lowering the pressure of the pressurized fluid to be injected, and then raising it again, the pressure of the pressurized fluid to be injected is measured, and this pressure is fed back to the molding machine's PLC, and the injection pressure is controlled using a needle-type regulator (pressure adjustment valve) that can automatically adjust the pressure (reference number 165).

[0125] The retraction of reference number 120 begins when the atmospheric release begins (the timer starts counting), or after a certain time has passed since the start of the counting (this time can also be set as desired). When the molding machine retracts the ejector plate (B) consisting of reference numbers 117 and 118, reference number 120 also retracts, so the pressurized fluid in the hollow part is completely exhausted and no residual pressure remains, so that the mold will not swell even when opened, and the problem of bursting is solved. Furthermore, reference number 120 must be at the forward end before the next resin is filled.

[0126] (Pressurized Fluid Injection, Retention, and Exhaust in Blow Molding) (External Controller) When operating the apparatus shown in Figure 35 using an external controller, a separate controller is installed to control this device. The molding machine inputs and outputs signals, and interfaces with the controller to operate the apparatus shown in Figure 35 for blow molding. The timing of pressurized fluid injection occurs during resin filling and after filling is complete. During filling, the molding machine outputs a pressurized fluid injection command signal to the controller when the screw passes a predetermined position. Upon receiving this signal, the controller opens the injection valve 161 and begins injecting the pressurized fluid into the molten resin. The duration of the pressurized fluid injection is set by a timer installed in the controller. After the timer expires, the valve 161 closes, trapping the pressurized fluid within the hollow cavity. The inventors refer to this as the "retention time." The duration of the retention time is set by a timer installed in the PLC within the controller, which can be set arbitrarily. After the retention timer expires, the valve 163 opens and the pressurized fluid inside the hollow cavity is vented to the atmosphere. The venting time (also called the "release time" or "venting time") is set by a timer within the PLC, allowing it to be set as desired. When the atmospheric release begins (the timer starts counting), or after a certain amount of time has passed since the timer started counting (this time can also be set as desired), or when the atmospheric release timer finishes counting, an ejector plate retraction signal is sent to the molding machine. Upon receiving this signal, the molding machine retracts ejector plate (B) consisting of reference numbers 117 and 118, which also retracts reference number 120. This completely exhausts the pressurized fluid within the hollow, eliminating any residual pressure. This prevents the mold from expanding and bursting when it is opened. Note that reference number 120 must be at the forward end before the next resin is filled.

[0127] (Pressure molding) (When writing to the molding machine's PLC) Blow molding involves injecting pressurized fluid into the resin filled in the cavity. Pressure molding involves filling the gap between the molten resin filled in the cavity and the mold, and the pressure (force) of the pressurized fluid is used to improve transferability to the opposite surface. The equipment used is that shown in Figure 35, and the mold shown in Figure 26. The pressurized fluid is sprayed, just like in blow molding, either during filling, after filling is complete, or a short time after filling is complete {If multiple devices like those in Figure 35 are used, prepare a program for each device and set the optimal pressurization time (timing) for each.} The subsequent hold time and exhaust time are set using roughly the same program as in blow molding.

[0128] In compressed air molding, increasing the mold temperature slows the cooling and solidification rate, increasing the transfer effect of the pressurized fluid. However, to prevent the pressurized fluid from entering the molten resin rather than the gap between the resin and the mold, resulting in a hollow molding, reference numeral 126 may be retracted (the ejector plate (C) consisting of reference numerals 129 and 130 is retracted) during the resin filling process and before the pressurized fluid is ejected after filling is complete, creating a small space where the pressurized fluid will be ejected, into which the pressurized fluid is then ejected. Reference numeral 126 is retracted after the molten resin has filled the cavity and a certain amount of time has passed since 0 seconds (this time can be set as desired). This operation is performed by a program written into the PLC in the molding machine.

[0129] (Pressure Molding) (External Controller) When pressure molding is performed using an external controller without programming the molding machine's PLC, the process is essentially the same as for blow molding. The retraction of reference numeral 126 is initiated by issuing a retraction signal from the molding machine to the controller, which triggers the retraction after a certain time has elapsed since the controller's internal timer started at 0 seconds. After the timer expires, reference numeral 161 opens, initiating pressure molding. After the pressurized time has elapsed, valve 161 closes, temporarily trapping and retaining the pressurized fluid. Once the retention timer expires, the exhaust timer begins counting, and the exhaust valve 163 opens, releasing the pressurized fluid into the atmosphere. Once the pressurized fluid release is complete (the atmospheric release time expires), the controller sends a mold-open permission signal to the molding machine. The molding machine receives this signal, and once the cooling time and other conditions are met, it opens the mold and removes the molded product. The molding machine then sends a mold-open signal to the controller, resetting the controller's program. Note that reference numeral 126 must be at the forward end before the next resin fill.

[0130] (Manual) A series of operations, such as injecting liquid, stopping, opening valve 151, opening valve 154, opening valve 161, and opening valve 163, must be performed manually, so a manual switch is provided on the molding machine's PLC, and on the external controller if an external controller is used. When an external controller is provided, signals must be exchanged between the molding machine's PLC and the external controller's PLC, complicating the programming between them. It is simpler and more economical to write programs for liquid injection, GCP, blow molding, air molding, and other operations, using gas as needed, into the molding machine's PLC. Furthermore, since signal exchange becomes more complex when these programs are implemented as combined operations, it is recommended to use the molding machine's PLC rather than an external controller.

[0131] The following description will be given using comparative examples, examples, and embodiments. Comparative Example 1

[0132] A linear aromatic PC resin (Teijin Chemical Co., Ltd., Panlite-L1225WP), natural color (transparent), was dehumidified and dried at 80°C for 2 hours in advance. The pellets were then mixed with an inorganic chemical foaming agent, sodium bicarbonate (NaHCO ). ３ ) is a bulk powder and therefore has white powder properties} was mixed at 0.7 wt.%, and foam molding was performed without GCP using a 180-ton injection molding machine manufactured by Toyo Machinery & Metal Co., Ltd., using a mold with the product shape (top plate thickness 2 mm) shown in Figures 1 and 2. The mold surface temperature during molding was approximately 45°C on both the fixed (cavity) and movable (core) sides, and the molten resin temperature was 260°C. The injection molding was performed without pressure dwell, with the screw terminated at the forward end, resulting in a slight short mold (no chipping of the shape (short mold, short shot) or the like). A foam molded product using sodium bicarbonate as the foaming agent was obtained. Since GCP was not implemented, swirl marks appear on the surface of the resulting foam molded product. In order to check the strength, a molded product was placed on the floor and a person weighing 75 kg slowly put his entire weight on top of it. The result was that it had no inherent PC strength and was as brittle as shrimp crackers, and it was confirmed that foam-molded PC products that use baking soda as a foaming agent cannot withstand normal use. Baking soda is not suitable as a foaming agent for PC foam molding. Comparative Example 2

[0133] In Comparative Example 2, the sodium bicarbonate foaming agent used in Comparative Example 1 was replaced with ADCA, an organic chemical foaming agent (it is a yellow powder because it is a bulk powder). The amount added was 0.35 wt.%, half the 0.7 wt.% of sodium bicarbonate. The mold, injection molding machine, and molding conditions used were otherwise the same. The resulting molded product was subjected to a load in the same way as in Comparative Example 1 to check its strength, but like Comparative Example 1, it had no strength, and PC molded products using ADCA as a foaming agent cannot withstand the same use as regular PC molded products. ADCA as a foaming agent is not suitable for PC foam molding. Comparative Example 3

[0134] Using the liquid injection device shown in Figure 1 of PCT / JP2015 / 062611 and the injection port provided in the heating barrel (shown in Figures 4 and 5 of PCT / JP2015 / 062611), 1.5 wt. % ethanol (chemical formula: C) was injected into the heating barrel at the beginning of the compression zone of the screw. ２ H ５ A fixed amount of ethanol (C OH) was continuously injected from the start of metering to the end of metering, and foamability was imparted to the plasticized molten resin using ethanol (the ethanol vapor was vaporized in a heating cylinder and pressurized to dissolve and / or finely disperse the ethanol vapor in the molten resin that was being melted and kneaded during metering), and a foam-molded product was obtained in the same manner as in Comparative Examples 1 and 2. A load was applied in the same manner as in Comparative Example 1 to check the strength, but as in Comparative Examples 1 and 2, there was no strength, and foam-molded PC products using ethanol as a foaming agent were unusable. Ethanol as a foaming agent is unsuitable for PC foam molding. Isopropanol (C OH) was used instead of ethanol. ３ H ７ The same is true for OH, and alcohol is not suitable for use in the production of foamed PC products.

[0135] Unlike the PC, foam moldings made with ethanol (EtOH) and isopropanol (IPA) show almost no deterioration in physical properties, unlike the PC foam moldings made with ethanol and isopropanol (IPA), m-PPO (PS, or HIPS-modified, PA-modified, or PP-modified), PP, or 6-nylon. It is speculated that the ethanol and IPA vapors, which reach a supercritical state inside the heating barrel, attack the PC, changing its molecular structure (degrading it to lower molecular weight), resulting in a deterioration in physical properties. For similar reasons, foam moldings made with PET and PBT using ethanol and IPA also show a significant deterioration in physical properties. Comparative Example 4

[0136] In Comparative Examples 1, 2, and 3, GCP was not applied (no GCP was used), and swirl marks were observed on the surfaces of all the foam-molded articles. GCP was applied using the nozzles shown in Figures 20 to 22 of PCT / JP2015 / 062611, the seal mold sealed for GCP shown in Figures 23 and 25, and the GCP device shown in Figure 24 (the gas used was 1.4 MPa air compressed with a reciprocating compressor. In the present invention, the seal mold shown in Figures 20 and 21 and the GCP device shown in Figure 15 were used). Foam molding was performed, and foam-molded articles were obtained that had a clean, smooth skin layer free of swirl marks on the surface and fine foam cells (foam layer) inside. However, when strength was confirmed in the same way as in Comparative Examples 1, 2, and 3, a significant decrease in strength was observed, as in Comparative Examples 1, 2, and 3.

[0137] While searching for a blowing agent for PC resins from Comparative Examples 1 to 4, undried PC (linear aromatic PC resin {Teijin Chemicals, Ltd., Panlite-L1225WP}) resin pellets (water absorption rate of approximately 0.1 wt.%) were molded without the use of sodium bicarbonate as a blowing agent in Comparative Example 1. As a result, several voids due to moisture in the resin (previously absorbed moisture) occurred in the spool, runner, and molded product. However, the molded product using this undried PC did not experience any loss of strength. Based on this, the inventor hypothesized that water might be usable in foam molding of PC. Based on the results of preliminary experiments, the inventors discovered the feasibility and effectiveness of water. After extensive research, they confirmed that water is effective in foam molding of PC resins, and broadly, ester-based resins, which led to the completion of the present invention.

[0138] In Comparative Example 3, foam molding was carried out using 0.5 wt. % water (distilled water, ion-exchanged water, tap water, city water) instead of ethanol. As a result, as shown in Figure 3, the foam cells were large, measuring several millimeters (mm), but when water was used as the foaming agent, there was no deterioration in physical properties as with ethanol, and no cracks occurred even when a load was applied. The physical properties of the foam-molded PC product were fully maintained, and water was an effective foaming agent for obtaining foam-molded PC products that were fully usable.

[0139] (Foam nucleating agent) 100 parts by weight of a linear aromatic PC resin (Panlite-L1225WP, manufactured by Teijin Chemical Co., Ltd.) was uniformly mixed with 5 parts by weight of aluminum oxide using a tumbler, and the mixture was fed into a vented twin-screw extruder to produce a pellet-shaped resin composition, which was designated A001, a master batch containing 5 parts by weight of aluminum oxide as a foam nucleating agent.

[0140] Similarly, a master batch B001 of a foam nucleating agent containing 5 parts by weight of silver oxide instead of aluminum oxide was prepared.

[0141] Similarly, a master batch C001 of a foam nucleating agent containing 5 parts by weight of silicon dioxide instead of aluminum oxide was prepared.

[0142] Similarly, a master batch D001 of a foam nucleating agent containing 5 parts by weight of silicon carbide instead of aluminum oxide was prepared.

[0143] In Example 1, no foam nucleating agent was used, resulting in large, coarse foam cells. In Example 2, the effects of using foam nucleating agents—aluminum oxide, silver oxide, silicon dioxide, and silicon carbide—were examined to determine whether the foam cells could be refined. Panlite-L1225WP was mixed with 100 PC resin pellets and 5 parts of the foam nucleating agents—master batch A001, master batch B001, master batch C001, and master batch D001—at a mixing ratio of 100:5. Water (distilled water) was injected into the heating barrel at a ratio of 0.4 vol.% of the resin volume under the same conditions as in Comparative Example 1, resulting in a foam-molded PC product using water as the blowing agent. The injection-molded product obtained in Example 3 exhibited fine-celled foam structures due to the effects of the foam nucleating agents A001, B001, C001, and D001. The results of Example 3 show that the foam nucleating agents contained in Masterbatch A001, Masterbatch B001, Masterbatch C001, and Masterbatch D001, which are foam nucleating agents, sufficiently refined the foam cells during foam molding. The resulting foam-molded articles containing aluminum oxide, silver oxide, silicon dioxide, and silicon carbide as foam nucleating agents were loaded and tested for strength in the same manner as in Comparative Example 1. The addition of aluminum oxide, silver oxide, silicon dioxide, and silicon carbide as foam nucleating agents resulted in almost no deterioration in the physical properties of the PC. Naturally, the influence of water as a foaming agent on the physical properties was also hardly observed.

[0144] When the GCP described in Comparative Example 4 was applied to Example 3, a foam-molded product was obtained which had a clean, smooth skin layer without swirl marks on the surface and foam cells of approximately 50 μm or less inside.

[0145] In Examples 3 and 4, the foam nucleating agents Masterbatch A001, Masterbatch B001, Masterbatch C001, and Masterbatch D001 were used individually. However, in some cases, the addition ratio was adjusted to the 5% ratio used in the examples, or to a 2.5% ratio of A001 and a 2.5% ratio of B001, or to a 2.5% ratio of A001 and a 2.5% ratio of C001. Even when the three foam nucleating agents A001, B001, and C001 were mixed at a ratio of 5, or when all three foam nucleating agents A001, B001, C001, and D001 were used, the effects of each foam nucleating agent were fully demonstrated, and it was confirmed that they refined the foam cells. Naturally, increasing the amount of foam nucleating agent produced finer foam cells, while decreasing the amount produced coarser foam cells. Because it is a master batch, the desired foam cell size can be achieved by controlling the amount added, whether it is large or small. When GCP is performed, the presence or absence of swirl marks on the surface can be confirmed (adding a large amount of foam nucleating agent makes the foam cells finer, but the foaming power increases and swirl marks occur on the surface. In this case, increasing the GCP pressure or using carbon dioxide gas in the GCP will allow for the production of a clean, smooth foam molded surface without swirl marks). This will allow the optimum amount to be added.

[0146] Can the present foam nucleating agents, aluminum oxide, silver oxide, silicon dioxide, and silicon carbide, refine foam cells not only with PC alone but also with PC-based resins? The effectiveness of using water as a foaming agent was confirmed using the methods of Examples 2 to 4 for all of the molding materials listed below, and the results were positive. It was also possible to use resins such as PC / ABS, PC / PS (polystyrene), PC / PVC (vinyl chloride, polyvinyl chloride), and PC / polyamide (PA). When using water as a foaming agent with PC-based resins, distilled water is preferable, but ion-exchanged water is also acceptable. City water or well water can be used, but calcium ions (Ca ２＋ ), magnesium ions (Mg ２＋The presence of calcium ions accelerates the decomposition of PC, so a total hardness (total concentration of calcium ions and magnesium ions) of 100 ppm or less (water) is desirable, with 35 ppm being even better. Foam nucleating agents have been effective in PC / PET, PC / PBT, and PC / PEN (polyethylene naphthalate) blends, but as mentioned above, these resins hydrolyze in PET, PBT, and PEN, resulting in a significant deterioration in physical properties. These foam nucleating agents are not limited to PC-based resins; they can also be used as foam nucleating agents for styrene-based resins such as ABS and HIPS, olefin-based resins such as PP, nylon-based resins, and vinyl-based resins such as PVC.

[0147] During the plasticization and weighing of Sumika Polycarbonate Co., Ltd.'s PC (SD Polyca (trade name) 301-15 (grade)), 0.5 wt. % ion-exchanged water was injected from the start of weighing to the end of weighing, relative to the weight of the molded product (weight of the molten resin in the heating barrel) shown in Figures 1 and 2, and vaporized in the heating barrel, imparting foamability to the heated and melted PC resin, resulting in the molded product shown in Figure 3. Because no foam nucleating agent was mixed into the resulting molded product, the foam cells were coarse and large, about 2 to 5 mm in size, but unlike with sodium bicarbonate, ADCA, or ethanol, there was no deterioration in physical properties, and the product displayed the inherent physical properties of PC (Figure 3).

[0148] Immediately after the GCP was vented, the movable mold was retracted by 1 mm, and the mold backing was performed from a 2 mm plate thickness to 1 mm immediately after the GCP was vented, increasing the expansion ratio. The mold backing reduced the pressure on the resin molded product, resulting in foam cells growing to 10 mm, and in some places even reaching 20 mm (Figure 4). Despite the large foam cells, the mold was pressurized to 1 MPa using the GCP device shown in Figure 15, and the PC resin molded product was foamed with water under pressure. The surface was clean and smooth, with no swirl marks (Figure 4). The surfaces of molded products such as those in Figure 4 were textured to prevent the raindrop phenomenon, a problem unique to GCP.

[0149] GCP was performed using air at a pressure of 1 MPa, and a foam-molded product with a clean, smooth surface was obtained. However, because no foam nucleating agent was added, the foam cells were very large (approximately 5 mm in diameter, and in some places even larger than 5 mm) (Figures 3 and 4).

[0150] When Sumika Polycarbonate Co., Ltd.'s PC (SD Polyca (trade name) SI8000L (grade)) was foam-molded with ion-exchange water in the same manner, ultrafine foam cells were obtained. When GCP was performed using the same air at 1 MPa pressure, the foaming power was too strong and unable to suppress the surface swirl marks. While Example 7, which used only 301-15, produced coarse and large foam cells, the addition of SI8000L (mixing) refined the foam cells, confirming that the surface swirl marks could be somewhat suppressed by GCP. When 70 parts of 301-15 pellets were mixed with 30 parts of SI8000L pellets, and the components of SI8000L were used as a foam nucleating agent, the foam cells were finer than in Figures 3 and 4, and foam cells of 1 mm or less were visually confirmed to be uniformly dispersed throughout the molded product (Figure 5). The foam nucleating agent used in this example is a light diffusing agent.

[0151] A mixed resin prepared by mixing 80 parts of 301-15 pellets and 20 parts of SI8000L pellets was similarly foam-molded using ion-exchanged water. GCP was carried out in the same manner as in Examples 7 and 8, and although the number of swirl marks on the surface was further reduced compared to Example 8, a clean, smooth foam-molded product without swirl marks could not be obtained.

[0152] Example 10 was a variation of the blend ratio used in Example 9, with 90 parts 301-15 and 10 parts SI8000L. Using 1 MPa air (GCP, compressed to a pressure of approximately 1 to 1.2 MPa), the resulting PC foam-molded product had a clean, smooth surface and fine, clean foam cells, eliminating surface swirl marks. The resulting foam-molded product was confirmed to have sufficient strength. Figure 5 (photo) shows the result of retracting the core side of Example 8 by 0.5 mm after exhausting the GCP, increasing the expansion ratio {(2 mm + 0.5 mm (mold retraction amount = mold opening distance) ÷ 2 mm (initial plate thickness) = 1.25 (25 vol.% volume expansion)}. The foam cells were approximately 1 mm in diameter and present throughout the entire molded product. Due to the action and effect of the GCP, the molded product had a clean, smooth surface with no swirl marks.

[0153] A polymer alloy of PC and ABS (SD Polyca (trade name) IM6011 (grade)) manufactured by Sumika Polycarbonate Co., Ltd. was foam-molded using ion-exchanged water in the same manner as in Example 7. The GCP was air, and the pressure was 1 MPa. The PC / ABS ("PC / ABS" means a polymer alloy of PC and ABS) used in Example 11 was black in color, and the pigment acted as a foam nucleating agent, resulting in a fine foam layer inside and a clean, smooth foam-molded product with a surface free of swirl marks. When ethanol was used as a comparative example, physical properties were reduced. This suggests that water is an effective foaming agent even for PC-based polymer alloys.

[0154] In this Example 12, the resin used in Example 11 was confirmed to be that of another company. IM6011 was replaced with a PC / ABS resin {Techniece (trade name) T-251T-15 (grade)} from Nippon A&L Co., Ltd. The foam-molded product obtained had a smooth surface and fine foam cells inside, similar to Example 11. When ethanol was used as a comparative example, the physical properties were reduced. From this, it is concluded that water is also an effective foaming agent for PC-based polymer alloys.

[0155] A polymer alloy of PC and PET (polyethylene terephthalate) manufactured by Sumika Polycarbonate Co., Ltd. (SD Polyca (trade name) IM401-18 (grade)) was foam-molded with ion-exchanged water in the same manner as in Example 7, but the physical properties of PC / PET were not obtained at all, which was presumed to be due to hydrolysis of the PET. PET is used for cosmetic containers. When this cosmetic PET resin was foam-molded with alcohol, no deterioration in physical properties was observed.

[0156] The inclined pins shown in Figures 23 and 24 were sealed with a load-type O-ring. The load-type O-ring 106 was fixed with a nest 113. This sealed mold, fitted with the GCP device shown in Figure 15, was then subjected to a pressure of 1.4 MPa using air to confirm the absence of leaks. This sealed mold was then foam-molded using PP resin and a 4:6 mixture of ethanol and tap water as the foaming agent. A smooth foam-molded product with a clean surface and no swirl marks was obtained. GCP is typically performed using air with a reciprocating or screw-type compressor. However, if air causes discoloration or burning, nitrogen gas can be used. Carbon dioxide gas can be used, as it penetrates the molten resin from the tip of the cavity, improving fluidity. The gas used for GCP can be a mixture of air and nitrogen gas, air and carbon dioxide gas, or air, nitrogen, and carbon dioxide gas. The GCP pressure varies depending on the foaming agent used to impart foamability to the molten resin, the type and amount of foaming gas, the resin to be foamed, and the temperature of the resin. While GCP is a useful means of suppressing foaming and eliminating swirl marks, the gas inside the mold is a nuisance during resin filling, so if it is possible to suppress swirl marks, it is better to use a lower GCP pressure, which is a nuisance. The GCP pressure of the present invention should be high, i.e., above atmospheric pressure to suppress swirl marks. For general foam molding, a GCP pressure of 0.5 MPa or higher and 2.5 MPa or lower is preferred. A pressure of 2.5 MPa or lower is not preferred because the GCP pressure (compressed air pressure) will collapse the foam cells, preventing the formation of a foam layer inside. For foam molding, a GCP pressure of approximately 0.5 MPa to 2.5 MPa is preferred. If the goal is to eliminate silver in general molding using undried materials, 0.5 MPa may be possible.

[0157] When increasing fluidity by injecting liquid without foaming, the resin is held under pressure from the injection molding machine to crush the foam cells and prevent foaming (a foam layer is not formed), so the GCP pressure is sufficient as long as no swirl marks occur on the surface of the molded product. There are no restrictions on the GCP pressure as long as no short mold, discoloration, or burns occur due to the filling of the molten resin. If necessary, a high pressure of 2.5 MPa or more can be used, and in some cases a pressure of 0.5 MPa or less is also acceptable.

[0158] ABS absorbs moisture (water) at approximately 0.4 wt.% and 0.6 wt.%. Talc-containing PP and other materials also absorb moisture at approximately 0.2 wt.% to 0.8 wt.%, requiring drying before molding to prevent silver streaks. However, by using a sealed mold and applying a GCP (pre-pressurizing the mold) at approximately 1 MPa, molded products with clean, silver-free surfaces can be obtained with ABS and talc-containing PP without drying. Using GCP eliminates the need for drying the ABS to prevent silver streaks, resulting in economic benefits of power savings (electricity, energy, and energy conservation). There is no need to increase the GCP pressure more than necessary if silver streaks are not generated. The silver streak prevention measures for materials that do not require drying are not limited to ABS; other materials can also be used.

[0159] The inclined pin shown in Figures 23 and 24 was sealed with a load-type O-ring, and the load-type O-ring 106 was fixed with a insert 113 in a sealing mold, which was then pressure-molded at a pressure of 30 MPa using the blow molding and pressure molding device shown in Figure 35. There was no leakage of pressurized fluid from the shaft (reference number 108) of the inclined core, and it was confirmed that the action and effect of fluid pressurization were sufficient. The molding materials used were PP and ABS.

[0160] Using the mold shown in Figure 25, the resin was PP, and the foaming agent was a 4:6 mixture of water and ethanol as shown in Example 14. GCP (more precisely, outer GCP) of Example 14 was performed, resulting in a smooth, foam-molded product with a clean surface free of swirl marks. Inner GCP (a hollow molding process using a foamable resin) was then performed from the inside at a pressure of 30 MPa. When sufficient internal pressure was achieved, pin 120 was retracted, rapidly reducing the pressure inside the hollow portion and allowing foaming to occur inward. After cooling and solidification were complete, the mold was opened, but no swelling or bursting was observed. The effectiveness of retracting pin 120 was also confirmed for inner GCP using a foamable resin in Example 16.

[0161] Using the mold shown in Figure 36, blow molding was performed with HIPS using the injection device shown in Figure 35. To eliminate residual pressure in the hollow, the pin 120 was retracted, quickly reducing the pressure inside the hollow, and the mold was then opened, but no swelling or bursting due to residual pressure in the hollow was observed. This Example 17 confirmed the effectiveness of retracting the pin 120 even in blow molding using a non-foaming resin.

[0162] The inclined cores (reference numbers 10.7, 108, etc.) shown in Fig. 23 were inserted into the mold shown in Fig. 20, with the load-type O-ring 106 held down by a nest as shown by reference number 113 in Fig. 23. Using this mold, Examples 1 to 15 were carried out, and it was confirmed that the sealing of the inclined core was also possible as shown in Fig. 23. Furthermore, pressure molding was carried out using the mold of Example 18 at a nitrogen gas pressure of 30 MPa, and it was confirmed that the mold using the nested structure to seal the inclined core was sufficiently pressure-resistant to pressure molding and had sufficient sealing properties.

[0163] Example 18 is a mold in which the inclined pins shown in Figure 23 are sealed, but Example 19 is a sealed mold in which multiple inclined cores and ejector pins are sealed with load-type O-rings 106 as shown in Figure 24 and fixed with a nest 113, and it has been confirmed that this is a sealed mold that can be used for mass production by foam molding using the GCP of Example 18 and pressure molding.

[0164] Figure 7 shows an IC tray mold with six pin gates, approximately 4 mm in diameter, recessed into the product surface (reference number 4 is the IC tray cavity). Instead of first opening the PL, reference number 8 was opened and the pin gates were cut, then the PL was opened and molded back to increase the expansion ratio. Foam molding was performed using ABS and modified PPO (PP modified with PPO), resulting in foam-molded products with a weight reduction of approximately 30% (approximately 10% due to the lack of dwell pressure, and approximately 20% due to mold expansion caused by mold backing). Air GCP at 1.2 MPa confirmed the production of a clean, smooth foam molded surface without swirl marks. IC trays require high dimensional accuracy and minimal warpage, so low-dwell pressure foam molding and blow molding are preferred. Foam molding uses a foaming agent, which can be liquid, gaseous, or solid, but considering the risk of foam residue in the foam-molded IC tray affecting the IC, gases such as nitrogen gas or carbon dioxide gas, which do not leave foam residue, or alcohols such as ethanol or IPA, or water, are better. Foam molding and blow molding also reduce the mold clamping force to less than half that of conventional solid molding, so in addition to stack molding, it is also possible to implement multi-cavity and multi-cavity molding in which the shape of the molded product is processed on the same PL surface. In fact, the IC tray in Figure 7 (Figure 10 is the IC tray processed in Figure 7) measures 135 mm in length, 315 mm in width, and 8 mm in thickness, and in normal molding it is processed using an injection molding machine with a clamping force of 180 tons, with a single cavity; however, in foam molding the required clamping force is at most 80 tons, so two-cavity processing was used, in which two identical IC trays were processed in one mold, or two IC trays of different shapes were processed, with a dissimilar two-cavity processing method, and IC trays of satisfactory quality with little warping or deformation were obtained.

[0165] A gas injection pin was inserted into the runner shown in Figure 7 from the fixed side, and the nitrogen gas pressure was increased to 20 MPa. After filling the cavity with non-foaming resin, gas was immediately injected for 5 seconds to form a hollow section. The gas was then trapped (retained) in the hollow section for 10 seconds, and vented, resulting in a hollow molded product with a hollowness of 8% (compared to the weight of a general molded product).

[0166] In Example 22, a hollow was formed after filling the cavity with non-foaming resin, but in this Example 22, the mold was retracted by 0.2 mm (mold back) while injecting high-pressure gas, resulting in a hollow ratio of nearly 20%. Furthermore, in Examples 21 and 22, the same experiment was performed using a foaming resin to which foaming properties had been imparted using ethanol, verifying that blow molding is possible even when using a foaming resin.

[0167] Automotive floor mats are available in rubber and thermoplastic elastomer (TPE) forms. This Example 22 involved foam molding using elastomers. The blowing agents used were Advancel (trade name), Expancel (trade name), a masterbatch of olefin-based elastomer (TPV) surface-mounted with 20 wt.% ADCA, and a masterbatch of olefin-based elastomer (TPV) surface-mounted with 20 wt.% sodium bicarbonate. Ethanol was used as a liquid blowing agent. It was confirmed that olefin-based elastomers could be foamed using any of these blowing agents. Similarly, foaming was possible with TPS and TPU. The ester-based TPC showed a decrease in physical properties with both solid and liquid blowing agents, and TPC could only be foamed with nitrogen gas. TPEs, including TPV, are broadly divided into seven categories: TPA, TPC, TPO, TPS, TPU, TPV, and TPZ, and are further divided into 32 categories based on the difference between hard and soft segments. While this Example 22 was explained using an automobile mat as an example, it is inferred that foam molding is possible for all molded products using TPE. Of course, foam molding alone will cause swirl marks on the surface, so GCP was performed using TPV and TPS with air pressure of 1 MPa, resulting in a foam structure with no swirl marks on the exterior and fine foam cells inside. If raindrops occur due to GCP air entrapment, open the mold by approximately 0.1 mm or 0.2 mm after venting the GCP to smoothly vent the pressurized air in the gap between the resin and the mold. Furthermore, evacuating the mold after venting can further reduce raindrops.

[0168] Foam molding was performed using an 850-ton injection molding machine manufactured by Toyo Machinery & Metal Co., Ltd., using an olefin-based thermoplastic elastomer (hereinafter referred to as "Material A"). The blowing agents used were sodium bicarbonate and ADCA. First, we will explain the results of foam molding using sodium bicarbonate. A foaming agent master batch was prepared by supporting 20 wt.% sodium bicarbonate on the surface of pellets of Material A. Material A was blended with 0.5 wt.% sodium bicarbonate alone and foam molding was performed at Material A's melting temperature of 215°C. The resulting foam molded product had no swirl marks on the surface and a foam layer was observed inside, but the foaming power of the sodium bicarbonate was insufficient, resulting in sink marks. ADCA was used instead of sodium bicarbonate, with the ADCA content at 0.25 wt.%, half that of sodium bicarbonate. As with the sodium bicarbonate case, a clean, smooth foam molded product with no swirl marks was obtained without the use of GCP. The internal foam cells were a mixture of fine and coarse (large) cells. The large foam cells were determined to be due to a lack of blowing agent. The ADCA content was increased to 0.5 wt.%, resulting in fewer coarse foam cells, but no swirl marks on the surface. The molded product was initially 3 mm thick, and after filling was completed, the mold was retracted by 0.2 mm to increase the expansion ratio. Next, a hole was drilled in a location where liquid could be injected into the molding machine's heating barrel (near the screw's compression zone; in liquid foam molding, alcohol or other liquids vaporize rapidly when placed inside the heating barrel. It is best to have the molten resin wrapped around the screw, sealing it, to prevent vaporized vapor from leaking into the hopper. A liquid inlet was installed in front of the point where the molten resin wraps around the screw (near the nozzle). Ethanol was then introduced through the hole, imparting foamability to Material A, which was vaporized, plasticized, and metered. Unlike the baking soda and ADCA cases, swirl marks appeared on the surface. The difference in the occurrence of swirl marks is that in the case of chemical foaming agents, when material A is mixed with a foaming agent master batch and poured into the heating cylinder from a hopper, part of the foaming agent immediately undergoes thermal decomposition, generating foaming gas. Most of the foaming gas generated in thermoplastic resins such as PP and ABS is finely dispersed and dissolved in the resin, with only a small amount escaping to the hopper side, so the foaming resin filled into the cavity has sufficient foaming power, causing many swirl marks to occur on the surface.On the other hand, with material A, the resin plasticized and melted at a slow rate, and in the case of the chemical foaming agent sodium bicarbonate, ADCA, the decomposition rate of the chemical foaming agent was faster than the rate at which material A plasticized, so much of the foaming gas escaped into the hopper, and the desired foaming power was not imparted to material A, so foaming was not very strong (the foaming gas was smaller, and in smaller quantities. Foaming power was weaker), and the occurrence of swirl marks was hardly observed. On the other hand, with alcohol, the foaming agent ethanol was added to the completely melted resin near the compression zone (to the molten resin), so many swirl marks occurred. Furthermore, material A was blended with 5 wt.% calcium carbonate as a foam nucleating agent.

[0169] Since the foaming agent used in material A was supported on the pellet surface of material A, it is better to use a foaming agent that has been melt-kneaded and contained inside. After the material containing the foaming agent master batch is charged from the hopper into the heating barrel, it is better to plug the heating barrel to prevent the foaming gas from escaping to the hopper side. Example 23 was explained using an automobile mat, but the embodiment is not limited to mats and can be applied to all foam-molded products molded from TPE.

[0170] An actual mold for an automobile floor mat was used. The TPE to be foamed was TPV, the foaming agent was a solution of maleic acid-modified PP in TPV, and a foaming agent master batch was used, with the TPV surface supported with 20 wt.% sodium bicarbonate. The foaming agent master batch used consisted of the TPV as the carrier resin. As a result of molding, fine foam cells were observed in approximately 60% of the mold, starting from the gate. However, foaming did not occur at the flow end (the end of the molded product). No foam cells were observed. This was due to the foaming gas (carbon dioxide and water vapor) generated by the sodium bicarbonate escaping from the hopper. It is recommended to install a check valve at the rear of the screw, as shown in Figure 53, to seal the hopper and prevent foaming gas from escaping. An injection molding machine with the reference number 239 (in this example, a molding machine with a Mucell-type screw) was used.

[0171] In the case of foaming TPE such as TPV, in addition to using the foaming agent master batch mentioned above, if the TPE pellets to be foamed are supported with, for example, maleic acid-modified PP, the dispersion of the foaming gas improves and uniform foam cells are formed all the way to the edges of the molded product. Naturally, ADCA, a liquid such as alcohol, or a combination of the foaming agent master batch and the like may also be used, and a screw having reference number 239 may be used.

[0172] In the case of TPV foam molding, using a GCP with a pressure of approximately 1 MPa results in a smooth, clean TPV foam molded product with a clean surface free of swirl marks. Even when using solid foaming agents such as baking soda or ADCA, or liquid foaming agents such as water or alcohol, a screw with a 239 screw prevents the foaming gas from escaping from the hopper. A screw with a structure equivalent to 239 can also be used in extrusion molding. With a screw without a 239 screw, vaporized gases from moisture and residual monomers in the resin escape from the hopper, but with a 239 screw, they are difficult to escape, resulting in silver smearing. In this case, the screw should be replaced or a GCP should be performed.

[0173] In Example 23, a master batch of a blowing agent in which ADCA or sodium bicarbonate was supported on the surface of material A to be foamed was used. In Example 24, a master batch was not used, and pellets of material A containing 0.25 wt. of ADCA were produced in advance in the granulation (pelletization) process (stage) of material A. The ADCA-containing pellets were used in the injection molding machine and mold used in Example 23. As a result, a foam-molded product of material A with an even higher expansion ratio than in Example 23 was obtained.

[0174] A similar experiment was carried out using 0.5 wt.% sodium bicarbonate instead of ADCA, and it was confirmed that the expansion ratio was higher than in Example 23. The reason for the higher expansion ratio compared to the method in Example 23 is that when melting the TPE of Material A, for example, ABS or PP, the viscosity quickly decreases upon melting, allowing the foaming gases nitrogen gas, carbon dioxide gas, and water vapor to be incorporated into the resin (by finely dispersing in the molten resin, dissolving under pressure, etc.), but the viscosity of Material A does not decrease as quickly upon melting, so much of the foaming gas generated by thermal decomposition of the foaming agents, such as ADCA and sodium bicarbonate, escapes from the hopper. In Example 24, the necessary amounts of foaming agents, such as ADCA and sodium bicarbonate, are kneaded into Material A. Therefore, when Material A melts, heat is applied to the foaming agents and thermal decomposition begins only at that time, making it easier to incorporate a large amount of foaming gas into Material A, and as a result, sufficient foaming can be achieved with a small amount of foaming agent. In this Example 24, ADCA and sodium bicarbonate were used, but DPT and other bicarbonates (Li, Na, K, Rb, Ca, Mg, etc.) can also be used. In this case, the use of GCP can naturally suppress swirl marks. To further improve the kneading ability, it is possible to use Dulmage or to use a flight with a highly kneadable shape.

[0175] (Confirmation of improved fluidity) The inventors confirmed that injecting 1.5 vol.% of ethanol into PP nearly doubles its fluidity. Using a 1,300-ton injection molding machine, an actual 3D mass-produced mold (the housing of the office equipment used in the 55th embodiment) was produced. When 1.5 vol.% of ethanol was injected into Novatec BC03B PP resin (MFR (MI value) = 30 g / 10 min), it exhibited roughly the same fluidity as the same PP resin, BC06C (MFR = 60 g / 10 min). Using the same mold, these results confirmed that the fluidity of ABS, a styrene-based resin, was also significantly improved.

[0176] Foam molding was performed on PP containing 60% talc by weight and 1.5% ethanol. At a pressure of approximately 1 MPa, the talc was able to sink into the molded product, and no floating talc was observed on the surface of the foam-molded product. The use of alcohol during this molding experiment significantly altered the switching point to VP, confirming the significant effect of ethanol's improved fluidity. When resin with enhanced fluidity using ethanol rather than foam molding was filled into the cavity and sufficient resin holding pressure was applied from the molding machine screw, the improved fluidity was confirmed, but swirl marks (not the foam stripes of foam molding, but silver streaks caused by ethanol) did appear on the surface. Furthermore, floating talc added to the resin was also observed. Talc sinking can also be achieved with IPA.

[0177] Using 1 MPa of air pressure, GCP was performed, resulting in a smooth, clean, and silver-free foam-molded product with a clean, smooth surface and no talc lift. Even when applying sufficient dwell pressure from the screw to collapse the internal cells and produce a conventional molded product, the fluidity was higher than with foam molding (which is to be expected, since dwell pressure from the screw is used). GCP also resulted in a smooth, clean, and silver-free foam-molded product with a clean, smooth surface and no talc lift. Using solid blowing agents, such as ADCA or bicarbonate, slightly improved the fluidity, but not as much as liquids. We also confirmed that using gases, such as MU-CELL and SOFIT, also improved the fluidity, but not as much as liquids. Amotec uses carbon dioxide, which can be expected to improve the fluidity to some extent, but not as much as liquids. Handling carbon dioxide requires complex and expensive equipment, and liquid-based equipment is superior in terms of both initial and running costs.

[0178] The screws that can be used in this invention are those that are capable of general molding, but they can also be used with screws that have a dullness like a Mucel screw, screws that have two compression zones like a Sofit screw, or long screws with an L / D ratio of 28 or 26 or so. In foam molding that uses a gas like a Mucel screw, a check valve is provided at the rear of the screw to prevent the gas from escaping to the hopper. Since the liquid is injected into the molten resin, the molten resin behind the part where the liquid is injected acts as a check valve. In the case of a screw that has a check valve, liquid vapor will not escape to the hopper side, so it is possible to add liquid to semi-molten resin.

[0179] In the case of foam molding, the process of filling the cavity with molten resin involves pushing the screw all the way to its forward end (stopping). Alternatively, the process can be stopped midway without stopping. While hydraulic machines typically stop the process to stabilize the fill weight, electric machines can stop the process midway without stopping. After filling the cavity with the foamable resin, the screw can be retracted and / or a dummy shape (see the figures in Patent Documents 1 to 7, and the book "Preparation for Mass Production of Foam Molding, Blow Molding, and Pressure Molding, and Explanation of Specific Means for Reducing Environmental Impact," by Yasutomi Suzuki and Minoru Niibo, published by S&T Publishing Co., Ltd. on October 20, 2022, First Edition, First Printing) can be used to fill the cavity using a short mold. This reduces the pressure of the molten resin in the cavity and facilitates foaming. In other words, in the case of foam molding, a method is required to reduce the pressure of the foamable resin filling the cavity as quickly as possible. To facilitate foaming, the resin temperature and mold temperature should be set higher, which will slow down the cooling and solidification rate inside the mold, making foaming easier.When the resin temperature and mold temperature are set higher, the surface skin layer will become thinner if GCP is used.

[0180] On the other hand, we will explain how to use a liquid to enhance fluidity and perform general molding. As mentioned above, the substance that enhances fluidity is a liquid at 1 atmosphere (atm) and 23°C. Since foaming is not the purpose, it is a liquid that can be vaporized or not vaporized in the heating barrel. In other words, unlike foam molding, the boiling point does not need to be a consideration. For ease of use, if improved fluidity is desired, it is better to vaporize the substance and dissolve or finely disperse it in the molten resin under pressure (using back pressure during metering). In this way, the foamable molten resin is filled into the cavity, and a cushioning amount is applied. By applying resin dwell pressure via the screw, as in general molding, or by compressing part or all of the mold to increase the resin density, the foam cells collapse under that pressure. The foaming gas used to form the foam cells is squeezed (squeezed, crimped, or squeezed) out of the molten resin using these resin dwell pressures. Since foam cells are not formed, the GCP pressure can be high. It is also acceptable for the GCP pressure to collapse the foam cells. Since the purpose of GPC here is to eliminate swirl marks and submerge additives, there is no need to balance the pressure to avoid interfering with the formation of internal foam cells, as is the case with foam molding. Fluidity varies depending on the resin, so the amount and type of liquid injected will vary. GCP pressure does not need to be increased more than necessary; keeping it as low as possible prevents interference with the filling of the molten resin, which can cause short molds, discoloration, and burns. Naturally, if fluidity is increased by the liquid, the filling pressure can be reduced, allowing for large molded parts to be molded at low pressure, thereby allowing for economical use of a smaller molding machine. Lowering the filling pressure also reduces residual stress within the molded part, resulting in molded parts with less warpage and deformation. High-fluidity resins improve mold transferability. Crystalline resins, such as olefin-based resins like PP, cool and solidify faster upon contact with the mold surface than amorphous resins like ABS and HIPA, allowing for lower GCP pressure settings.

[0181] It has been confirmed that using carbon dioxide gas in GCP allows the carbon dioxide gas to dissolve from the leading edge of the flow, further improving fluidity. Amotec has reported that using carbon dioxide gas as a blowing agent increases fluidity, but it does not have the same effect as liquid. Carbon dioxide gas and liquid can also be used in combination. Medium-sized air bubbles, such as Advancel, use organic solvents, which have been experimentally confirmed to have higher fluidity than those using baking soda or ADCA. Commercially available medium-sized air bubbles are manufactured using an extruder as a blowing agent master batch. However, it is also possible to support the material on PP, ABS, etc. using maleic acid-modified PP varnish (solution) or styrene-modified acrylic resin varnish (solution).

[0182] To improve fluidity, it is also advisable to apply a textured finish to the non-decorative surface. In addition to the textured finish, a coating such as TiN, CrN, or DLC may be applied. Of course, textured finishes and coatings may be used in combination.

[0183] Using a resin with high fluidity allows for a reduction in the pressure of the gas injected into the molten resin filled in the cavity that forms the hollow during blow molding (blow injection molding). With molten resin with high fluidity, the hollow portion is formed at a lower pressure, resulting in a hollow molded product with less warping and deformation. Reducing the pressure of the gas injected into the molded product allows for a hollow molded product with high dimensional accuracy. Using a resin with high fluidity reduces or eliminates hesitation marks, a defect unique to blow molding, resulting in a hollow molded product with a clean surface.

[0184] When using molten resin with increased fluidity, in the case of pressure molding (pressure injection molding), the melt viscosity decreases, improving transferability to the mold. In the case of pressure molding, transfer to the mold can be improved by using high-pressure gas inserted between the resin and the mold (also known as "gas dwelling"), or by using a combination of gas dwelling and resin dwelling. In this case too, the gas pressurization effect is greater when the resin temperature is set high and the Kanabata temperature is also set high. The gas pressurization effect is even greater in processes such as heat and cool and BSM using high-frequency induction heating. In the case of pressure molding, it is very effective when a printed film or the like is placed in the mold first for molding transfer.

[0185] In the case of resins whose fluidity has been increased by using a liquid, it is possible to improve the transferability to the mold even in general molding. A resin with high fluidity has the effect of improving the transferability to the mold.

[0186] To increase the fluidity of resin, low molecular weight resins are mixed in, or polymer alloys or polymer blends are made with other resins. Methods such as using fluidity improvers such as wax, stearic acid, and stearates are used, but this increases the unit price of the resin and is not economical, and these additives inevitably decrease the physical properties of the resin. In the case of liquids, the resin is squeezed out of the molded product by pressure retention, so the physical properties of the resin are not affected. Also, the liquids used are not expensive, so there is little or no economic problem of a large increase in the unit price of the resin. Office equipment, etc. V ０ High flame retardancy, such as -5VA or B, is required, and thinner walls are being developed to reduce the amount of resin used. Thin-walled molded products made with such resins are molded at high pressure and speed using molding machines with large clamping forces, but this can lead to problems such as flash on the PL and a short mold life. Furthermore, molded products that are to be painted require higher pressures and longer dwell times to eliminate sink marks. These problems can be easily solved by using a liquid resin with increased fluidity, which solves them all at once.

[0187] We have shown that the fluidity of molten resin is significantly improved when a large amount of liquid is injected. However, if the resin is molded without any liquid injection, swirl marks will appear on the surface, preventing a clean, smooth molded product, no matter how much the resin dwell pressure or mold temperature is increased. Using a GCP eliminates these swirl marks. We confirmed that when a molten resin with increased fluidity is used in the mold by rapidly venting the pressurized gas in the GCP, fewer short molds occur compared to when a GCP is not used. We believe this is due to the GCP creating a negative pressure in the mold in a short time, reducing the number of short molds. Figure 61 shows an aspirator attached to the mold, creating a negative pressure inside the mold by venting the pressurized air inside the mold. Reference numeral 279 indicates the sealed mold for a GCP, as shown in Figure 20, etc., and the pressurized air is released into the mold by opening valve 280. Reference numeral 281 denotes the compressed air introduced into the mold, and 282 denotes the compressed air circuit installed within the mold. Reference numeral 283 denotes the direction of the gas flow that initially pressurizes the mold. Once the mold is pressurized, valve 280 closes and check valve 284 is forced open during or after filling with resin that has been given foaming properties by liquid or other means or resin with enhanced fluidity. Reference numeral 285 is placed inside 284. A ball check valve is installed, and 285 is normally closed by an internal spring (not shown). A signal to open (exhaust) the compressed air within the mold is transmitted to hydraulic and pneumatic cylinders 286, and when rod rod 287 connected to the cylinder is pressed, 285 is pushed up, and the compressed air is exhausted to the atmosphere through aspirator 288. This exhaust gas flow (reference numeral 289) draws some of the compressed air within the mold into 293, creating a negative pressure within the mold. Reference numeral 290 denotes the flow of compressed air being exhausted, 291 denotes a portion of the compressed air that passes through the aspirator 288 and creates negative pressure, and 292 denotes a portion of the compressed air inside the mold that is sucked in by the aspirator 288. Device 294 is an aspirator. When compressed air inside the mold is passed through reference numeral 295 and exhausted through 296, negative pressure is generated inside 294, and gas is sucked into 294 through 297. The sucked gas is exhausted to the outside together with 296.

[0188] For example, molding materials such as ABS are dried at 80°C for about an hour to avoid appearance defects such as silver, but if GCP is used, beautiful molded products without silver can be obtained even when molding general materials without drying and without improving fluidity using liquid.If foam molding is not performed, there is no need to worry about the foam cells being crushed by the pressure of the GCP, so the GCP can be high pressure, such as 1 MPa, 2 MPa, or even higher.The ability to mold without drying saves energy and reduces carbon dioxide emissions.

[0189] We confirmed a method of cleaning the inside of the heating barrel by pouring a liquid into it and vaporizing it. When changing from black PP to white, purging agents (cleaning agents) such as Asaclean (trade name) and Z Clean (trade name) are generally used, but these purging agents have economic issues such as being expensive, and there is also the problem of the purging agent remaining. It is also known to add a small amount of chemical foaming agent, such as baking soda, ADCA, or DPT, to the purging agent to enhance the cleaning effect through its foaming power, but there is a problem of the foaming agent residue remaining inside the heating barrel.

[0190] In Example 28, we confirmed that a small amount of liquid used during material and color changes, rather than using the commercially available purging agent, was sufficient to achieve a cleaning effect (higher) than that of the commercially available purging agent. During metering, a liquid such as alcohol or water was introduced into the liquid injection port during foam molding using the liquid of the present invention. The liquid vaporized during this process was vaporized depending on the temperature of the heating barrel and the temperature of the molten resin, allowing the molten resin to foam and be purged. The vaporized liquid increased the pressure inside the heating barrel, enhancing the cleaning effect. Repeating the same procedure (start metering, liquid injection, completion of metering, liquid injection stop, injection, etc.) confirmed a high cleaning effect. A 1:1 mixture of IPA and water was used in the heating barrel at 2 wt.% of the metered resin. Changing the color of the PP from black to white required less than half the amount of white PP compared to using only the resin (white PP) to be molded next. Unlike baking soda, ADCA, and the like, liquid alone does not leave any foaming residue, so there is no problem of undecomposed foaming agent or foaming residue remaining inside the heating barrel or nozzle.

[0191] The liquid used for cleaning can be just alcohol, such as ethanol or IPA, or a mixture of alcohol and water. Adding a small amount of surfactant (ionic, nonionic, anionic, cationic, amphoteric, or nonionic), such as alkylbenzene sulfonate sodium (soda) (the abbreviation is the same as for resin, "ABS"), to alcohol or a mixture of alcohol and water has been shown to be effective in cleaning. Furthermore, adding baking soda and dissolving it in water can further enhance the cleaning effect. In this case, since the baking soda is dissolved in water, there is little chance of baking soda or its decomposition product, sodium carbonate, remaining inside the heating barrel or nozzle.

[0192] Of course, the liquid may be used in combination with the commercially available purging agent, which has the economical effect of reducing the amount of the commercially available purging agent used.

[0193] Since this is a purge, it is fine for the nozzle to be open and for it to snort. In the case of a hot runner, cleaning (purging) using a liquid that does not leave any foaming agent residue is recommended for cleaning the inside of the manifold and nozzle, and for subsequent resin replacement. Although only liquids have been explained, gases that do not leave any foaming agent residue can also be used. Good gases include nitrogen gas, carbon dioxide gas, liquefied carbon dioxide gas, and dry ice. A combination of gas and liquid is also acceptable. To further enhance the cleaning effect, resins containing glass fiber or talc, such as AS with glass fiber, or high-viscosity resins such as PC can also be used in combination with liquid.

[0194] Nozzle cleaning can be easily achieved by injecting liquid into the molten resin inside the nozzle during injection and allowing it to vaporize due to the heat of the nozzle. Gas, of course, is also acceptable. However, we have confirmed that liquid provides a more effective cleaning solution than gas. While Example 28 was described using an injection molding machine, this method is not limited to injection molding machines and can also be used for purging or color changes in extruders and other machines. Hot runner purging can be achieved by providing a liquid and / or gas inlet (similar in structure to the inlet provided in the heater barrel) in the manifold and introducing liquid and / or gas through the manifold. In addition to purging with liquid and / or gas through the manifold, purging with liquid and / or gas through the nozzle of the injection molding machine achieves similar effects to injection through the manifold. Furthermore, the inside of a hot runner can also be cleaned using liquid and / or gas by directly injecting liquid and / or gas into the hot runner manifold. Naturally, if the resin is filled into the cavity, it becomes foam molding, and if the foam cells are crushed using holding pressure, it becomes general molding, which can also be expected to improve the fluidity of the molten resin using liquid and / or gas. In the case of a mold with a hot runner, there is a means to introduce liquid and / or gas into the manifold.

[0195] With growing interest in environmental issues, there is also a growing demand for energy conservation in resin processing. In this Example 29, a resin that is not dried (i.e., processed as is without drying) is used. The lack of drying, moisture on the surface and inside of the resin, and volatile components of the resin (e.g., solvents used in the resin manufacturing process, resin monomers, dimers, trimers, etc.) can cause appearance defects such as silvering on the surface of molded products. The above-mentioned silvering problem can be solved by using a GCP with the appropriate pressure.

[0196] Even in general molding (in this invention, after filling the cavity with molten resin, the volume that is reduced by cooling and solidification is pressed in with an appropriate pressure, which is called "resin holding pressure", and molding processing methods that use this resin holding pressure are called general molding, general processing, general molding, general processing, solid molding, solid processing, etc.), the use of GCP has been confirmed to have the effect of eliminating silver caused by the moisture and volatile components, and making the surface of the molded product clean and smooth. This Example 29 showed that by using GCP, defects such as silver can be eliminated on the surface of the molded product, even with a drying-less molding material.

[0197] For example, if ABS (Clarastic GA501 (product name and grade) manufactured by Nippon A&L Co., Ltd.) is molded without drying, the moisture absorbed by the ABS resin pellets will cause silver streaks to appear on the surface of the molded powder, making it unsuitable for use in exterior parts. Even if the molded product is painted, the silver streaks on the surface of the molded product will significantly reduce the adhesion of the paint film. By using the sealed mold shown in Figures 1 and 2 (sealing methods include sealing the ejector pins or an ejector box structure; Figures 1 and 2 show the ejector box configuration), and implementing GCP, ABS molded products with a good appearance and no silver streaks can be obtained without drying.

[0198] The ABS (which has absorbed water) that had been stored in a materials warehouse for about three months was used to carry out general molding processing using the GCP specification sealing mold shown in Figures 1 and 2 without carrying out GCP. As a result, a large amount of silver was generated on the surface of the molded product, resulting in a poor appearance and not meeting the customer's requirements.

[0199] Next, the undried ABS was filled into the cavity, which had been pressurized (i.e., pressurized, compressed air) inside the mold using a compressor, using the GCP device shown in Figure 15, to a pressure of approximately 0.8 MPa inside the mold. Simultaneously with the completion of filling (i.e., applying dwelling pressure to the resin from the heating barrel, but in this case this was done after the completion of primary pressure), the compressed air (GCP) inside the mold was released into the atmosphere. The resin dwelling pressure continued even after the compressed air was released. No silver was generated on the surface of the ABS molded product obtained in this process, and the surface of the molded product was clean, smooth, and of good quality, fully satisfying the customer's requirements.

[0200] Next, the ABS was immersed in tap water for 12 hours, allowing it to absorb water until it was saturated (approximately 0.5 wt % water). The absorbed ABS was scooped up and placed in a fine net for dehydration. This resulted in an ABS containing approximately 0.5 wt % water. When the absorbed ABS was molded using the molds shown in Figures 1 and 2 in the same manner, a large amount of silver was generated on the surface of the molded product due to water absorption inside the ABS. Next, GCP was performed at a pressure of 1 MPa, and no silver was generated on the surface of the molded product. This (common molding process using materials that have been immersed in water) indicates that if the GCP method is used, the material can be molded without drying (less drying), without any defects such as silvering on the appearance due to moisture. This Example 29 demonstrates that molding materials can be molded without drying using a sealed mold and the GCP method.

[0201] In addition to ABS, it has been confirmed that even with materials such as non-drying HIPS (Toyo Styrene H450 (product name and grade) manufactured by Toyo Styrene Co., Ltd.), modified PPO(E) (NORYL SE90 (product name and grade) manufactured by SHPP Japan LLC (formerly Sabic Japan LLC)), PC (SD Polyca 301-22 (product name and grade) manufactured by Sumika Polycarbonate Co., Ltd.), PCABS (Techniece PAX-1439 (product name and grade) manufactured by Nippon A&L Co., Ltd.), and PP (Sumitomo Noblen AW564 and Z744 (both product names and grades) manufactured by Sumitomo Chemical Co., Ltd.), the surfaces of the molded products obtained are (can be) clean and smooth, with no defects such as silver, using GCP (if GCP is implemented).

[0202] Although not shown, the mold in Figure 44 incorporates specifications for performing the pressure molding shown in Figure 26 and specifications for performing the blow molding shown in Figure 36. Using the mold in Figure 44, GCP was performed at 1 MPa and blow molding was performed on the ABS, HIPS, modified PPO(E), PC, PC / ABS, and PP without drying them. Pressure molding was also performed. Furthermore, blow molding and pressure molding were performed simultaneously, and it was confirmed that the silver disappeared.

[0203] GCP generally uses air, but for materials that discolor or burn, discoloration or burning can be prevented by using nitrogen gas instead of compressed air (it is sufficient to simply lower the oxygen concentration in the compressed air to, for example, 15 vol% or less). It has been confirmed that when carbon dioxide gas (a mixture of compressed air and carbon dioxide gas is also possible) is used in GCP, the carbon dioxide gas dissolves from the leading edge of the flow of the molten resin filled into the mold cavity, improving the fluidity of the molten resin. Blow molding was carried out with ABS and HIPS, whose fluidity was improved using a liquid. Pressure molding was also carried out. A combination of blow molding and pressure molding was also carried out.

[0204] (Embodiment 1) From Comparative Examples 1 to 4 and Examples 1 to 5, it can be seen that if a PC resin is used, and water is used as a foaming agent and aluminum oxide, silver oxide, silicon dioxide, or silicon carbide is used as a foam nucleating agent, it can be carried out not only by an injection molding machine but also by extrusion molding, and if the foamable resin that has come out (extruded) from the die is passed through a gas (which can be air, nitrogen gas, or carbon dioxide gas) with a pressure of 0.6 MPa or more, and the principles and means of GCP are also applied to extrusion molding, foaming on the surface can be suppressed, and extrusion molding without swirl marks can be achieved.

[0205] (Embodiment 2) In Examples 1 to 5 and in Embodiment 1, it was stated that water was used as the foaming agent, but even in the foam molding products Musel, Amotec, and Sofit (product name?) that use gases such as nitrogen gas and carbon dioxide gas for foaming, the foam nucleating agents exemplified in this invention, such as aluminum oxide, silver oxide, silicon dioxide, and silicon carbide, are used with PC-based resins, and the action and effect of the foam nucleating agent is fully exerted when implemented in injection molding, extrusion molding, and blow molding.

[0206] (Embodiment 3) The present invention adds to and claims that the present invention encompasses all of the parts (GCP devices, sealing molds, molding machines, and ancillary equipment such as shut-off nozzles) involved in foam molding described in PCT / JP2015 / 062611, PCT / JP2015 / 069216, PCT / JP2016 / 086380, and PCT / JP2020 / 015536.

[0207] (Embodiment 4) In the foam molding of PC resins, the foaming agent used in the examples of the present invention was water, and many other foam nucleating agents, other than aluminum oxide, silver oxide, silicon dioxide, and silicon carbide, can be used as long as they do not decompose the PC. Wet PC (water-absorbed PC) and another foam nucleating agent are mixed (spread on the PC surface with a small amount of water), and test pieces are molded using an injection molding machine to check for any significant deterioration in physical properties (decomposition of PC). If there is no significant deterioration in physical properties, the foam nucleating agent can be determined to be usable.

[0208] (Embodiment 5) (Means for Increasing Expansion Ratio) In foam molding, methods for increasing the expansion ratio include increasing the amount of foaming agent added to increase the foaming power of the resin, filling the cavity with foamable resin and expanding a portion of the mold to reduce the pressure of the filled foamable resin and facilitate foaming, and lowering the screw to reduce the pressure of the foamable resin and facilitate foaming. In addition, there is also a method for increasing the expansion ratio by opening the mold. When opening the mold, the mold structure can be divided into two types: one with a horizontal parting line (PL) (mold structure shown in Figures 11 and 12, with the retraction movement of the movable mold) and one with a vertical parting line (mold structure shown in Figures 13 and 14, with the retraction movement of the movable mold). The former is called mold back and the latter is called core back, and these are distinguished in this invention. When opening the mold back too far, there is a risk of flash occurring on the PL, so the mold should not be opened too far. When opening the mold back, there is a low risk of flash occurring on the PL, so a molded product with a high expansion ratio can be obtained.

[0209] (Mold Apparatus) This fifth embodiment can be implemented with either mold back or core back. Injection molding molds (mold structures) are either two-plate or three-plate. When using two-plate molds for mold back or core back, the movable die plate of the injection molding machine is retracted a predetermined distance to expand the cavity (mold, cavity) and increase the foaming ratio. When opening a three-plate mold in typical injection molding, if the PL opens first, it can be difficult to open the stripper plate (the removal plate for the spool runner). Therefore, it is common for the PL to have a PL lock mechanism, and the fixed mold plate and stripper plate are opened first. However, with this mold structure, even if the movable die plate of the injection molding machine is retracted, the stripper plate opens due to the PL lock, preventing mold back or core back. To solve this problem, the inventors did not use a PL lock. Instead, they fitted a spring or urethane rubber to the PL. By retracting the movable die plate a predetermined distance, the spring or urethane rubber would ensure that the PL opened first, allowing mold backing and core backing. A gas spring could also be used instead of a spring or urethane rubber. Hydraulic or pneumatic cylinders could also be used. The inventors called this a "first-mold-opening mechanism, first-mold-opening mechanism." After mold backing and core backing increase the expansion ratio and complete cooling and solidification within the mold, the die plate is lowered (retracted) to remove the foam-molded product. However, without a PL lock, the stripper plate remains stationary, preventing the spool runner from leaving the mold. The inventors then used a tension ring, tension bolt, chain, or other device to pull the movable die and stripper plate, using the mold opening mechanism to move the stripper plate and remove the spool runner from the mold (mold release). Tension rings, chains, and other devices are designed to prevent them from breaking or cutting when the molds are opened (for example, by installing a spring in the tension bolt).In addition to directly connecting the movable mold and the stripper plate with a tension ring, etc., it is also possible to connect the movable mold and the fixed mold with a tension ring, etc., and to connect the fixed mold and the stripper plate with a tension ring, etc.Figures 6 and 7 show a three-plate mold that uses the above-mentioned tension ring, etc., but in the case of a two-plate mold, springs, urethane, etc. may also be installed on the PL, and if installed, the mold back and core back can assist in retracting the mold.

[0210] This mold structure can also be implemented in the case of GCP. It is also effective in molds with a back-chamfer structure (a mold structure of three or more plates) (such as a stack mold), and just like with a three-plate mold, springs or urethane rubber can be installed on the PL on each product side to ensure that it opens first when the die plate retracts. In this case, if a seal mold is used, GCP can be performed to obtain a foam-molded product with a clean, smooth surface free of swirl marks and a high expansion ratio, using GCP. The mechanism for opening the PL first can also be implemented in molds equipped with hot runners. In this case, it is preferable for the hot runners to have an opening / closing mechanism (valve) such as a spring or needle type.

[0211] While stack molding is generally possible with horizontal injection molding machines, when injecting foamable resin from plastic, an injection molding machine with a vertical clamping mechanism and a horizontal injection mechanism (commonly referred to as a vertical injection molding machine) is used. In this case, a shut-off nozzle with a spring-type or needle-type opening / closing mechanism is used for stack molding with plastic injection. For foam-molded products suitable for stack molding, the foam molding process is particularly effective for increasing productivity in flat shapes (plate-like or plate-like shapes), such as IC trays used to transport semiconductors in semiconductor manufacturing plants. IC trays require electrical conductivity, so conductive carbons such as ketjen black and acetylene black, or carbon nanotubes (CNTs), are often added. Polymer alloys primarily composed of highly heat-resistant m-PPO and PC-based resins are commonly used for molding. PC-based resins can also be used alone; the type of resin is not important as long as the heat resistance requirement is met.

[0212] Normally, foam molding does not use holding pressure, or if it does, it is for a short time, so there is no need to precisely balance the filling of each molded product (cavity). It is sufficient to fill the cavity almost to the brim with foamable resin, or more than 70 of a cavity volume of 100. A short mold is acceptable because mold back and core back are used. Even if the volume exceeds 100, mold back and core back will occur, so the final volume will never exceed 100. The foamable resin is filled into each cavity approximately simultaneously (with one filling condition), but separate filling using sequential control is also acceptable.

[0213] The foam molding carried out in this embodiment 5 is foam molding using an injection molding machine, and the properties of the substance that imparts foamability to the resin, the so-called foaming agent, can be applied to all of the following foam molding techniques: techniques that use gaseous substances, for example, compressed gases such as Mucel and Amotec, or liquefied carbon dioxide, techniques that use liquid substances such as NPT such as alcohol or water, and foam molding techniques that use microballoons, macroballoons, microballoons, bicarbonates such as baking soda, azo compounds such as ADCA, and nitroso compounds such as DPT.

[0214] In the case of IC trays, careful consideration is required because using a chemical foaming agent can result in foaming gas and foam residue adversely affecting the IC and its plated leads. Foam molding using gases and liquids does not pose a problem because the foam residue does not get mixed into the molded product. The inventors actually used the IC tray mold shown in Figure 10 (photo) and m-PPO containing acetylene black as the molding resin. The foaming agents used were water, ethanol, propanol, a mixture of water with 40 wt.% ethanol, a mixture of water with 40 wt.% propanol, and a 1:1 mixture of ethanol and propanol. Approximately 1 wt.% of the resin (molded product) was placed in a heating tube and vaporized to form the foamable resin. Foam molding without GCP resulted in a weight reduction of approximately 6-10%. With GCP, the weight reduction was approximately 5-8%. The impact strength of each molded product was approximately 70% lower without GCP and only 25% lower with GCP, assuming that the impact strength of the solid (solid, general, solid, general) molded product was 100. While the above example was conducted using m-PPO, similar results are expected with PC-based resins. In this case, water is the preferred blowing agent. In terms of heat resistance and price, the molding materials suitable for IC trays are preferably m-PPO or PC-based resins with conductive properties. However, if the heat resistance requirement is not high, conductive resins with styrene-based resins such as ABS as the main component may also be used.

[0215] Molding back 25% of the molded part's thickness (wall thickness) resulted in a weight reduction of approximately 25%. The molded parts without and with GCP were obtained. In this case, the impact strength of the molded parts was further reduced, but this can be mitigated by adding graft rubber (a di-polymer of butadiene rubber grafted with styrene) contained in m-PPO in anticipation of this reduction in impact strength. Impact strength can also be increased by increasing the particle size of the rubber. In this case, using graft rubber with a different particle size will further improve impact strength. After molding back, the mold can be slightly closed and compressed again. After this, the mold must be opened and the molded part must be brought to the movable side (the side pushed out by the ejector pin), but depending on the shape, it may be taken to the fixed side. In this case, undercut or texture the side of the movable mold to ensure a balanced transfer to the movable side.

[0216] Substituting EPDM (ethylene rubber (ethylene-propylene-diene monomer)) for butadiene rubber further improves impact strength. EPDM has significantly higher thermal stability than butadiene rubber, and m-PPO, which uses EPDM graft rubber, is highly recyclable (its physical and mechanical properties deteriorate little even after repeated recycling and thermal exposure). m-PPO is manufactured by melt-kneading PPO and rubber grafted with PS. Using reduced-volume discarded polystyrene foam instead of PS (which is made of PS and is foamed using pentane, which leaves no foam residue, is acceptable) can contribute to reducing environmental impact. If necessary, general foam nucleating agents, including the PC-based resin foam nucleating agent described in this invention, can be used. Since IC trays are made by blending conductive materials such as acetylene black into m-PPO, acetylene black also acts as a foam nucleating agent. PC-based resins can also be used instead of m-PPO.

[0217] Using the mold shown in Figure 10, a resin made by imparting conductivity to PC{SD Polyca (trade name) 301-15 (grade) instead of m-PPO was foam-molded using ion-exchange water, and it was confirmed that foam molding was possible and weight reduction was also possible, just like with the m-PPO. Conductive carbons such as Ketjen Black and acetylene black, which impart conductivity, acted as bubble nucleating agents. Trials with CNT also showed that CNT also acted and was effective as a bubble nucleating agent, so these conductive materials that impart conductivity are effective as bubble nucleating agents and can be used sufficiently for molded products that require conductivity, such as IC trays.

[0218] (Embodiment 6) In addition to mold backs and core backs, breathing (expanding) cores and dummy shapes are used to facilitate foaming. First, we will explain the expanding core. Figures 37 and 38 show examples of dummy shapes (throwaway shapes, throwaway cavities) with shutters. This shape is the reverse of a submarine gate. When resin is filled into reference numeral 4 and partially or completely fills reference numeral 172 (Figure 37), the rod connected to the mold ejector plate reference numeral 168 retracts (Figure 38), either immediately or after a certain period of time. At this time, reference numeral 173 appears. Reference numeral 137 is connected to dummy shape 171 through the gate reference numeral 170. Therefore, the molten resin in reference numeral 4, which has residual pressure, flows into reference numeral 171 via reference numerals 172, 173, and 170. As a result, the pressure of the resin in reference numeral 4 decreases, facilitating foaming. Reference numeral 168 is a mechanism that moves using an ejector rod (for forward movement) and a spring (for backward movement) built into the mold, similar to ejector plates (B) and (C). If ejector plates (B) and (C) are built into the mold, reference numeral 168 may be a new ejector plate (D). Ejector plate (D) may have a two-plate structure, upper and lower, like (B) and (C), but since it simply has a pin, it can also be a single plate. Figures 37 and 38 show the reverse structure of a submarine gate (initially closed), but reference numeral 170 can also be implemented with other shapes.

[0219] (Embodiment 7) Using this rod structure and mechanism, automatic gate cutting can be easily implemented in foam molding, blow molding, and pressure molding processes that do not use pressure holding. Figures 39, 40, and 41 show the structure of the automatic gate cutter. Reference numeral 175 denotes the gate of the molded product 4, which is a superimposed gate (Figure 39). Resin is filled into 4, and immediately, or after a certain period of time, the rod connected to the mold ejector plate 177 advances, pushing 175 into the molded product 4 (Figure 40). As a result, the spool runner and gate are separated from the molded product 4 (Figure 41). In this case, there are no restrictions on gate height or width. For wide gates, simply use a plate wider than the gate width, with the tip of 177 aligned to the gate width. Automatic gate cutter in blow molding and pressure molding prevents backflow of pressurized fluid injected into the spool runner. There are no restrictions on gate width when automatically cutting gates in foam molding, blow molding, pressure molding, etc., greatly expanding the latitude of molding conditions. Foam molding, blow molding, and pressure molding do not use dwell pressure, and even if they do, the duration is short, so the automatic gate cutting shown in Figures 39 to 41 can be easily implemented.

[0220] Next, we will show a method for reducing the pressure of the molten resin filled in the cavity to facilitate foaming in foam molding using a dummy shape (a throwaway cavity) without a shutter. In Figure 42, the shapes indicated by 181 and 182 are dummy shapes connected by reference number 180. Part of the dummy shape is filled with resin (reference number 181), and the part indicated by reference number 182 is actually filled, which is a so-called short mold. Therefore, the pressure of the filled resin in reference number 4 is reduced, allowing it to foam easily, resulting in a foam-molded product with a high expansion ratio.

[0221] In blow molding and pressure molding, the dummy shape indicated by reference numeral 183 must be fully filled (filling the entire space of 183 with resin). In blow molding, the pressurized fluid injected into the molded product will seek out areas of lower pressure, and if reference numeral 183 is a short mold like reference numerals 181 and 182, the pressurized fluid will escape from there, preventing the formation of a sufficient hollow. Pressure molding is a molding method in which pressurized fluid is injected into the gap between the resin and the mold, and this pressure is used to pressurize the other side. In this case, too, if reference numeral 183 is a short mold, the pressurized fluid will escape from the end of the short mold, preventing a sufficient pressurization effect. The dummy shapes indicated by reference numerals 181, 182, and 183 require a longer cooling and solidifying time in order to reduce pressure, so the wall thickness of this part is often made two, three, or even more times thicker than the wall thickness of reference numeral 4.

[0222] (Embodiment 8) Super engineering plastics such as PPS (polyphenylene sulfide), PES (polyethersulfone), and PEI (polyetherimide) are thermoplastic resins with high melting temperatures. When foam molding is performed using low-boiling-point solvents such as ethanol (which has an ignition point of approximately 400°C at 1 atm), isopropanol, or hydrocarbons such as alkanes as blowing agents, if the ignition point of these liquids is higher than the temperature of the molten resin, there is a risk of fire, as well as discoloration or burning of the resin. In other words, the oxygen concentration in the hopper must be reduced. Nitrogen gas replacement is performed in the hopper. Furthermore, using air in the outer GCP still raises the resin temperature. If adiabatic compression further increases the temperature, discoloration or burning of the resin is a concern. Therefore, inert nitrogen gas can be used instead of air for pressurization. Carbon dioxide is also acceptable.

[0223] (Embodiment 9) Water- and alcohol-insoluble blowing agents, such as ADCA powder and HDCA powder, will precipitate (sediment) if simply added to water or alcohol due to their low viscosity. To slow the settling rate even slightly, a varnish with increased viscosity is used. If the resin to be foamed is PP, a solvent-based or water-based varnish for maleic acid-modified PP is used. If the resin to be foamed is ABS, for example, a varnish made from AS or ABS using a solvent (e.g., n-butanone) is used. For HIPS, for example, a varnish made from PS or HIPS in the same way as AS or ABS is used. Styrene-modified acrylic resin varnishes can be used with both ABS and HIPS. When using a low-boiling-point solvent, the hopper, etc., is purged with an inert gas, as shown in embodiment 8.

[0224] (Embodiment 10) The water holes (cooling circuits) of the mold used in the present invention will be described. Water holes are typically drilled using a gun drill, but because they are straight and curved (at uneven distances from the molded product), the heat exchange rate is not very high. Using thermal bonding (Yamatec Co., Ltd., 3-3-5 Mizuho-cho, Nishitama-gun, Tokyo 190-1232, TEL: 042-557-5660) or hot-melt adhesive, water circuits with high heat exchange rates can be created. Specifically, an optimal cooling circuit is created on the surface, for example, using a milling cutter or electrical discharge machining. This is called the first insert. Next, a insert with a shape to cover the first insert is machined. This is called the second insert. The second insert is placed over the first insert, and the surfaces are joined using thermal bonding or other methods to create a curved water circuit inside. The insert shape and the optimal flow path for the water holes are designed (calculated) in advance using CAD or other software. A water circuit can be created in the hexahedral first mold before the inserts are shaped, and also in the hexahedral second mold as needed, and then heated and bonded to create a hexahedron with a water circuit inside. This hexahedron can then be used to machine the shape designed in advance using CAD using conventional means. The reason why the first and second inserts are hexahedral is that the higher the surface accuracy of the joining surfaces (for example, polished surfaces are better than milled surfaces) the greater the joining strength. Although a hexahedron is used in the tenth embodiment, the shape is not limited to this.

[0225] (Embodiment 11) (Liquid Foaming Agent that Generates Nitrogen Gas) A compound that generates nitrogen gas with high foaming power is sodium azide (NaN ３ ) azides, azo compounds, such as ADCA, and nitrosates, such as DPT. Inorganic sodium azide is water-soluble, but NaN ３ Since sodium azide begins to decompose when dissolved in water, its aqueous solution cannot be stored for a long time and is therefore not suitable as a liquid foaming agent. ADCA derivatives that are soluble in alcohol include esters of ADCA, such as ADCA diethyl {DEAD(C ６ H １０ N ２ O ４ ) and an alcohol solution of DEAD can be used as a liquid foaming agent. ADCA isodipropyl (DIAD) is also soluble in ethanol, and an alcohol solution of DIAD can be used as a liquid foaming agent in the same way as the alcohol solution of DEAD. Simply putting ADCA powder into an alcohol such as ethanol and finely grinding it using a mill or the like will create a slurry, which can be used as a liquid foaming agent that generates nitrogen gas in the foaming gas containing ADCA.

[0226] Polyvinyl alcohol (PVAL) is compatible with thermoplastic resins due to its molecular structure. Polyvinyl butyral (PVB) is a thermoplastic resin that exhibits high adhesive properties with glass, metal, ceramics, etc., and is compatible with thermoplastic resins. Both (PVAL and PVB) can be used to create a viscous liquid with alcohol and water, so dispersing ADCA powder in these creates an ADCA-containing slurry, which can be used as a liquid blowing agent.

[0227] By thickening maleic acid-modified PP varnish and suspending ADCA powder, it becomes a liquid blowing agent for PP. By suspending ADCA powder in styrene-modified acrylic resin varnish, it becomes a liquid blowing agent for styrene-based resins such as HIPS and ABS. The thickener carboxymethyl cellulose (CMC) can also be used to thicken these maleic acid-modified PP solutions and styrene-modified acrylic resins slurried with ADCA. Air spheres can also be dispersed in addition to ADCA. Naturally, inorganic bicarbonates such as baking soda can also be used. Cellulose nanofibers (CNF) can also be added to thicken the mixture. CNF also acts as a foam nucleating agent during foam molding.

[0228] The chemical structure of ADCA shows that two molecules of urea can be combined. When combined with urea, this substance may become water-soluble, since urea is water-soluble. If it is water-soluble, it can naturally be used as a liquid foaming agent, and like ADCA, it will decompose thermally to generate nitrogen, a foaming gas.

[0229] (Embodiment 12) In the two-cavity, paired molding of Example 20, the foamable resin can be filled into each cavity at once, or each cavity can be filled separately. This section explains the filling method for paired molding when filling separately. Let's assume that the molded parts are A and B. The amount of resin to be filled into A and B is measured in advance. First, molded part A is filled, and the gate is switched to fill part B. Once A and B have cooled and solidified, the mold is opened and the molded parts are simultaneously removed. First, the amount of resin for molded part A is measured and filled into cavity A. After filling is complete, the amount of resin for molded part B is measured again, and the gate is switched to fill part B. Once A and B have cooled and solidified, the mold is opened and the molded parts are simultaneously removed. Using this molding method, the mold clamping (mold closing), cooling inside the mold, mold opening, and ejection (molded part extrusion) are common, resulting in an increased molding cycle and improved productivity. This method can also be implemented in the blow molding of Examples 21 and 22. After filling the cavity with foamable or non-foamable resin, the mold is closed and compressed, and then mold backing, core backing, etc. may be performed as needed. The IC tray-like shape can also be used as a so-called cassette mold, in which the insert for the molded product is replaced while the mold is still attached to the molding machine, in order to reduce mold costs. In this way, when switching between A and B molding, in addition to the gate switching mechanism, a valve-gate type hot runner can be used to open and close the valves separately. This A and B switching filling is performed by a program in the molding machine's sequencer.

[0230] The foam nucleating agent for PC resin explained in this invention is used for extrusion foam molding using PC resin. In this case, the foaming agent used is most preferably liquid water.

[0231] (Embodiment 13) Embodiment 13 illustrates the main challenges of plastic recycling and their solutions. While plastic recycling presents numerous technical challenges, the main ones are "color recycling," "restoring or maintaining physical properties," "dimensional reproduction," and "sorting." First, we explain "color recycling." While plastics have low mechanical strength, they are characterized by their low cost, mass-production capabilities, and the freedom to color them. This freedom to colorize means that plastic products come in a wide variety of colors, making color reproduction one of the obstacles preventing progress in plastic recycling. There are two methods for color recycling. One involves collecting only molded products of the same color, cleaning them, and crushing them. The crushed material is then mixed with virgin pellets or powder, and re-pelletized to obtain a molding material containing a certain amount of recycled material (approximately 10% to 50% by weight). This method reproduces colors, but it is a means of recycling only plastic molded products of a specified color.

[0232] (Cleaning methods) Molded products collected from the market are often dirty and have faded due to photodegradation caused by ultraviolet rays, etc. In such cases, the photodegraded areas (mainly the surface) are removed using shot blasting, etc. To clean, the molded product is placed in water and rubbed by hand, or ultrasonic cleaning is performed by inserting an ultrasonic vibrator.

[0233] When molded products are crushed in a crusher, sound is produced. A wet crusher is a crusher that uses this sound, and when crushing is done while water is being injected or underwater, sound is produced (generated), and this sound is transmitted into the water, and dirt on the surface of the molded product is cleaned using physical force (sound waves).

[0234] (Color recycling using paint) When there are molded products of various colors, they can be recycled into molded products of the desired color by crushing them as they are without color sorting and pelletizing them as needed to create various colors, or by molding the various colors of the molded products obtained by painting the surface of the various colored molded products. For coloring (decorative paint, cover mark paint), for example, if the resin that makes up the molded product is ABS, HIPS, or modified PPO, the paint is painted with a paint whose main component is styrene-modified acrylic resin that is compatible (miscible) with the resin that makes up the molded product. When a molded product with a coating film painted using the above-mentioned compatible paint is recycled, the coating film is not separated or peeled off, but is crushed with the coating film still attached, and if necessary, when the molded product is molded using pelletized molding material, the styrene-modified acrylic resin, which is the main component of the coating film, is compatible with the resin that makes up the molded product and melts into the resin at the pelletizing stage or / and the heating and melting stage of the remolding process, so there is less deterioration in the physical properties of the resin due to the coating film mixing.

[0235] Because the styrene-modified acrylic resin is a thermoplastic resin, paints using this resin have low chemical resistance, and the paint film peels off in a rubbing test using alcohol, for example. When chemical resistance is required, paints with urethane resin as the main component are often used (the urethane resin in the paint film is thermosetting, while the styrene-modified acrylic resin is thermoplastic). While it is best to separate and peel the paint film from molded products coated with a paint primarily containing urethane resin, if the paint film is not separated and peeled off but is instead pulverized with the coating film still attached and refined (to an average particle size of 1,000 μm or less, preferably 100 μm or less) using an extruder capable of high-intensity kneading, such as a twin-screw extruder or kneader, the physical properties will not be significantly reduced even if the urethane coating film is mixed with the molding resin. In some cases, there may be no decrease compared to thermoplastic styrene-modified acrylic resins (in the case of styrene-modified acrylic resins, the dyes and pigments in the coating melt during the pelletizing and remolding stages and migrate into the resin, degrading the physical properties of the resin, but in the case of urethane resins, since they do not melt, the dyes and pigments in the coating remain in the coating and do not migrate into the resin, so there is less deterioration in the physical properties of the resin).

[0236] The extruder with strong mixing can be a single screw, but preferably a multi-screw extruder (two or more) with one or more screws with dulmage. The screws can rotate in the same direction, but counter-rotating screws are better for improving mixing and finer urethane coatings. PP is widely used in automotive parts, so when painting PP molded products, a primer treatment is applied using maleic acid-modified PP, followed by a paint using a thermosetting urethane resin.

[0237] (Restoring Physical Properties) To enhance the physical properties of styrene-based resins such as ABS and HIPS, rubber grafted with the intended resin components is blended. We'll use ABS as an example. ABS is a blend polymer made by blending AS resin, a copolymer of A (vinyl cyanide) and S (vinyl phenylate), with a tertiary graft copolymer of A, S, and butadiene rubber, which is a graft copolymer of A and S onto butadiene rubber. When ABS is molded, pulverized, and remolded, the butadiene rubber in the tertiary graft copolymer of A, S, and butadiene rubber (grafted butadiene rubber) undergoes thermal degradation and loses its rubbery properties. As a result, repeated recycling reduces the resin's physical properties, such as impact strength. Deteriorated resin properties can be restored by blending in new grafted butadiene rubber. If the addition of grafted butadiene rubber reduces the resin's rigidity, AS resin is blended in to balance the effects, and the resin is recycled and reused.

[0238] (Thermal Properties of Blowing Agents) Here, we will discuss blowing agents suitable for recycling. Among solid blowing agents, inorganic blowing agents, such as bicarbonates like sodium bicarbonate, undergo thermal decomposition in the heating tube, absorbing heat when generating foaming gas. This is what is known as an endothermic reaction. In this invention, these are referred to as "endothermic blowing agents." On the other hand, the thermal decomposition of organic blowing agents like ADCA and DPT is an exothermic reaction, and these are referred to as "exothermic blowing agents." Liquid blowing agents like water, alcohol, and hydrocarbons vaporize from liquid to gas in the heating tube due to the heat or thermal energy of the heating tube and / or the temperature (heat, thermal energy) of the molten resin. These liquid blowing agents are "endothermic blowing agents." Gas-based foam molding, such as Mucel, Amotec, and Sofit, does not undergo a phase change and is therefore neither an endothermic nor an exothermic blowing agent. Therefore, endothermic foaming agents do not apply thermal energy to the molten resin inside the heating barrel, so the physical properties of the resin are not deteriorated by the thermal action of the foaming agent.The fact that exothermic foaming agents cause significant thermal damage to the resin is self-evident, as seen in the discoloration and burning that occurs in foam-molded products when using DPT, etc.

[0239] Therefore, when considering repeated plastic recycling, endothermic blowing agents are preferable to exothermic blowing agents, considering the thermal damage to the molten resin. However, solid blowing agents are unsuitable for plastic recycling due to the problem of undecomposed blowing agent and residual blowing agent in the foam-molded product. Gas and liquid blowing agents are suitable for plastic recycling because they leave no residual agent, but only liquids can produce foam-molded products with a clean, smooth surface at a GCP pressure of around 1 MPa. Liquids are optimal for plastic recycling. Furthermore, because liquids are endothermic blowing agents, they do not cause thermal damage to the molten resin. This invention has demonstrated that using liquids improves fluidity. Lowering the melting temperature of the molten resin (e.g., the heater setting temperature of the heating barrel) allows for foam molding at a lower temperature, which further avoids thermal stress and damage to the molten resin and reduces thermal degradation. Furthermore, being able to process at a lower melting temperature naturally reduces carbon dioxide emissions.

[0240] The above content is not limited to foam molding, and the same can be said about improving fluidity using the liquid of the present invention (technical content). In other words, the fluidity of the liquid can be greatly improved. As with the foam molding described above, the molded product does not contain any residue caused by the liquid, and other effects such as lowering the resin temperature during molding can also be expected. Note that this content can be implemented not only in injection molding, but also in extrusion molding and other molding methods.

[0241] (Maintaining physical properties) ABS has poor weather (light) resistance due to butadiene rubber. AAS (ASA) and AES, which use acrylic rubber (AR) or ethylene propylene rubber (EPM, EPDM) instead of butadiene rubber, do not experience the same significant deterioration in physical properties as ABS, even when recycled repeatedly. As a simple means of confirming recyclability, the inventors used an injection molding machine equipped with a shut-off nozzle, set all zone temperatures to 220°C, and set the temperature of the molten resin to 250°C. The resin was melted and kneaded, and allowed to remain in the heating barrel for 30 to 60 minutes, applying thermal stress to the molten resin in the heating barrel. After a predetermined time (e.g., 30 minutes) had passed, the resin was purged, the purged mass was immersed in water to cool, and the cooled purged mass was crushed. The crushed material was used to mold test pieces for evaluating physical properties, and the physical properties were evaluated (this method is referred to as a "thermal degradation test" in this invention). As a result, the Izod impact strength of AES was 0% to 5%, and even that of AAS was less than 10%, but a significant decrease of more than 50% was confirmed in ABS.

[0242] Similarly, in the case of PE (polyethylene), the retention test showed almost no decrease in Izod impact strength, and the strength was almost the same as that of virgin material, with no significant decrease in physical properties confirmed. PE has high thermal stability and can be said to be a resin suitable for recycling.

[0243] In the case of PP (polypropylene), based on its molecular structure, there are syndiotactic PP, isotactic PP, and atactic PP.Furthermore, the catalysts used during polymerization include Ziegler-Natta catalysts and metallocene catalysts.When thermal degradation tests were conducted on each of these, the reduction in Izod impact strength was only about 5% for all PPs, and the results showed that PP has high heat resistance and is a resin suitable for recycling.

[0244] Just as the surface of a molded product is always wet by absorbing moisture from the air, a permanent antistatic resin (Toray Industries, Inc.'s Parel (product name)) made by mixing polyether ester amide with ABS showed a thermal degradation test in which the Izod impact strength decreased by nearly 90%, so it can be said that Parel is not a resin suitable for recycling.

[0245] (Recycling Aids) "Recycling aids" are materials and additives that restore recycled materials to their original physical properties. Resins added for the purpose of modifying properties are also recycling aids. For example, ABS loses impact strength when recycled. Adding half the same ABS can restore some of the properties. Both ABS, which is developed to reduce the impact of recycled materials, and the aforementioned AS are recycling aids. AES has high thermal stability, so blending recovered AES with recycled ABS can restore the properties of the ABS. In this case, AES is also a recycling aid in the broad sense. HIPS, used to modify EPS, is also a recycling aid. In this way, recycling aids are defined as original resins and resin additives. Paints used to restore color (e.g., cover marking molded products to a different color) are also recycling aids.

[0246] (Maintaining dimensions) When recycled resin is subjected to heat history, some of the molecular chains are broken and the resin becomes lower molecular weight. In addition, the fluidity of the molten resin changes when recycling aids are added to restore physical properties, so in injection molding, with the general injection molding method (a molding process in which molten resin is filled into the cavity and then holding pressure is applied to eliminate defects in the molded product such as sink marks), there is a large variation in dimensions (variation in molding shrinkage) and the dimensions are not as stable as when virgin material is used, and with recycled materials, there is a large variation in dimensions and they are not stable. To solve this problem, if foam molding (injection foam molding), blow molding (injection blow molding), or pressure molding (injection pressure molding), which are molding methods that do not use pressure holding, are used, and the main components (molecular structure) of the resin to be molded are the same, the molding shrinkage rate of the recycled material will be roughly the same as when foam molding, blow molding, or pressure molding is performed using virgin material, so when recycling, it is better to use foam molding, blow molding, or pressure molding than general molding.

[0247] The addition of recycled materials (which refers to plastic materials made from either or both of spools and runners at the molding process site, defective molded products crushed and pelletized as needed, and plastic molded products recovered from the market) changes the fluidity, which in turn changes the effectiveness of resin dwell pressure in general molding. (Because the addition of recycled materials increases fluidity, the effectiveness of resin dwell pressure is greater than with virgin materials at the same pressure. Differences include greater warpage and deformation, and higher molding shrinkage. This varies depending on the recycled material mixing ratio and recycling history (number of recycling turns).) When using molding materials that contain recycled materials, the difference in dwell pressure can be reduced by using a liquid to increase fluidity, as explained in this invention. This reduces the dwell pressure effect of the resin regardless of whether the recycled content is high or low. (With increased fluidity, the pressure applied by dwell pressure is roughly the same regardless of the length of the resin's molecular chain.) This stabilizes the molding process.

[0248] (Sorting) When recycling, if you cannot accurately understand what resins are used in the molded products to be recycled and what additives are mixed in those resins and in what amounts, recycling cannot be carried out completely. Below, we will explain in detail and specifically the preparations that are required in advance for recycling (sorting).

[0249] First, we'll use ABS as an example to explain the resin that is the main component of molded products. As mentioned above, ABS is a blend polymer, or polymer alloy, made by mixing an A and S copolymer with grafted butadiene rubber. Various ratios of resins can be produced for AS by adjusting the polymerization ratio of A and S (A to S ratio). Naturally, resins with different molecular weights (e.g., number average molecular weight, average molecular weight, etc.) are produced depending on the polymerization initiator and polymerization terminator, resulting in differences in molecular weight distribution. Even with butadiene rubber, there are differences in the A to S ratio and grafting rate. Various particle sizes (bimodal type) of grafted butadiene rubber are used to compound AS. In this way, a wide variety of ABS types can be produced.

[0250] (Other Additives) As mentioned above, dyes and pigments are used to color ABS. If flame retardancy is required, flame retardants (e.g., halogen-type or non-halogen-type) and flame retardant aids are added. Other additives used in resins as needed include antioxidants, antioxidants, antiozonants, UV absorbers, light stabilizers, plasticizers, fillers, reinforcing agents, PVC stabilizers, lubricants, slip agents, internal mold release agents, anti-fog agents, antistatic agents, colorants (including the dyes and pigments mentioned above), coupling agents, preservatives, mildew inhibitors, compatibilizers, modifiers, crystal nucleating agents, dispersants, light diffusers, and bubble nucleating agents (in the case of foam molding) (collectively referred to as "resin additives," or simply "additives"). These additives are listed in, for example, the "Handbook of Rubber and Plastic Compounding Chemicals, Revised Second Edition (Rubber Digest Co., Ltd., Revised Second Edition, October 30, 1993)." Although these additives may be usable when molded articles containing these additives are processed and delivered to the market, they may become substances that should not be mixed in when the articles are recovered from the market and recycled several years later. Let's take flame retardants as an example. Previously, flame retardants were typically made using halogen compounds, such as brominated epoxy and TBBA (tetrabromobisphenol A derivative), which utilized the negative catalytic action of halogens, with antimony trioxide as a flame retardant aid. However, their use is now discouraged due to concerns about the generation of brominated dioxins and brominated benzofurans. Antimony trioxide is a highly toxic substance, so its use is discouraged. Today, when recycling articles containing halides, they must be recycled separately.

[0251] However, as mentioned above, it is not possible to accurately grasp the information (type of resin, additives, etc.) necessary to carry out recycling (equivalent recycling, higher-level recycling) simply by looking at the molded product, and as a result, recycling becomes lower-level recycling.

[0252] (Marking) As mentioned above, it is difficult to grasp the vast amount of information required for recycling solely from the mandatory recycling markings. Therefore, the inventors have inscribed barcodes (either standard barcodes or two-dimensional barcodes (QR codes)) on the molds of molded products weighing a certain amount, e.g., 100 grams (g) or more. The barcodes contain the weight of the molded product required for recycling, as well as information about the resin that is the main component of the molded product, such as molecular weight, the ratio of A to S, and information about the additives mentioned above (type and amount), as well as the weight of the molded product. A useful method is to write this information on molded products, collect them from the market, and then read it during the recycling process, e.g., before cleaning or crushing. At the recycling stage, it is confirmed that the product does not contain any banned substances before crushing. Molded products that contain banned substances are stored in a separate location without being crushed.

[0253] Because the amount of information is enormous, it is given to each molded product as a barcode, preferably a QR code (two-dimensional barcode). QR codes are preferable to barcodes because they can store more information. A label (sticker) with the QR code printed on it is affixed. Alternatively, for injection molded products, the QR code can be engraved into the mold beforehand, eliminating the need to affix a label (Figure 44). In the following, the present invention will be described using a QR code (Figure 48, reference number 206).

[0254] The QR code information is read with a barcode reader, and once the crushed material is crushed, it is possible to determine the type of resin and the amount of additives contained in the crushed material. Once this is done, a computer, such as artificial intelligence (AI), can be used to easily modify the material by adding the necessary additives in the required amounts. The aforementioned QR code can also be displayed on molded products made from recycled materials in this way, with the next recycling in mind. This allows for repeated recycling (repeated recycling generations {first turn, second turn, third turn, etc.}). Of course, the QR code information also includes the content (mix ratio, etc.) of the material from the first turn and the material from the second turn. In other words, the necessary information is always added to prepare for future recycling. This ensures that future recycling can be carried out without any problems.

[0255] (Confidentiality) QR codes can read, for example, the name of the resin manufacturer, the product name, the grade, and detailed resin formulation (such as the type and amount of additives). This poses the risk of important confidential information of the resin manufacturer being leaked to competitors, so it is not desirable to leave it as is. To prevent this, some or all of the information contained in the QR code must be encrypted (for example, using a combination of numbers or letters, such as prime numbers). The encrypted information is kept within the AI, including the type of resin, the type and amount of additives, and the weight of the crushed material (meaning the total weight of the crushed molded products, the weight information of the molded products written into the QR code, or the weight of each molded product automatically measured and entered into the AI). Necessary security measures must be imposed on the AI ​​and on the person operating the AI ​​(such as an operator) to ensure that this information is never leaked to other companies.

[0256] (Recycling Implementation) Specific recycling and resin modification are all handled within the AI. Since the AI ​​confirms and understands all information related to the resin and additives of the crushed material intended for recycling, when the AI ​​is instructed on the type of resin to modify the crushed material into, it calculates the type and amount of resin and additives (e.g., type and amount of recycling aids) required for recycling. The AI-calculated type and amount of resin and additives are added to the crushed material in advance, and test pieces are molded and processed. Physical properties are measured (quality control). The results are confirmed to match the AI-calculated values ​​(the expected physical properties of the recycled material). If the results are satisfactory, the AI ​​adds the type and amount of resin and additives required for recycling, and the recycled material is manufactured using the necessary means (e.g., melt-kneading using a single-screw, co-rotating, or counter-rotating multi-screw extruder, or kneading, pelletizing, etc.). The obtained recycled material is sampled to measure its physical properties, and these are compared with the physical property values ​​confirmed before production to confirm whether the recycling has been completed to the desired physical property values.

[0257] ("Equivalent recycling," "upper recycling," and "lower recycling.") For example, recycling a molded product (such as a printer housing) from an office equipment printer into another printer housing is called "equivalent recycling." Since the main component of expanded polystyrene (such as EPS) is PS (GP), if the reduced and crushed product is mixed with butadiene rubber (styrene graft copolymerized with butadiene rubber) and pelletized, it can be modified to HIPS (high impact polystyrene). In this way, using a low-grade material like EPS and modifying it with HIPS to create a higher-grade HIPS, which is more valuable than EPS, is called "upper recycling." By mixing this HIPS with PPO (polyphenylene oxide) and adding flame retardant, the same Noryl (trade name) can be produced using EPS. However, currently, management is not carried out using QR codes as described in this invention, and the resins and additives in molded products cannot be identified, so if they are simply crushed without separating the types of resin and used as resin to process artificial wood, flower pots, etc., this is called "lower-level recycling." Molded products collected from the market are combustible, so if they are used as fuel in cement factories, steel mills, thermal power plants, etc. and recycled as thermal energy (a lower-level energy type), this is lower-level recycling, and in this case it becomes a one-time use. This is also "lower-level recycling."

[0258] (Flow of recycling method) This shows the actual flow of plastic recycling using this invention. Virgin resin is used for molding and processing, and painted as necessary. Molded products marked with QR codes are supplied to the market and collected once their role is complete. The QR codes on the molded products are used to check whether they are recyclable or whether they contain any substances that inhibit recycling. Recyclable molded products are washed as necessary. Alternatively, deteriorated parts of the surface are removed using blasting or other methods.

[0259] When items of the same material and color are collected, they are crushed, the necessary recycling aids calculated by AI are added, and the material is tumbled to make it uniform, pelletized, and reused as recycled material.In this case, the amount of recycled resin contained, the amount of each additive, and the amount of recycling aid are recorded on the molded product, as it will be recycled again in the future, and information about the resin and additives that make up the molded product is also written on the molded product using a QR code or similar.

[0260] Even when crushing assorted or mixed colors without color-coding, only molded products that are determined to be recyclable based on the QR code are crushed, and the AI ​​confirms the type of resin and additives contained in the crushed material, as well as their quantity. In the same way, recycling aids and other additives are added, tumbled, pelletized, and remolded. The resulting molded products can be used as they are, whether mixed or mixed colors, but if coloring is required, they are painted as a cover mark. Naturally, these molded products are engraved with a QR code containing information on the type and quantity of recycling aids and other additives, including the fact that they have been painted, with the assumption that they will be recycled.

[0261] In this way, by using a QR code on a molded product to provide the information necessary for recycling, recycling becomes easier. Even when recycling is carried out again, the QR code provided on the molded product ensures that recycling can be carried out. Since it is not possible to imprint an imprint on a molded product when using a mold such as vacuum molding without using a mold, for example, the QR code can be silk-screened or a sticker with a QR code printed on it can be attached. Of course, information such as the ink used for silk-screen printing and the material of the sticker can also be written on the QR code.

[0262] (Embodiment 14) With the growing interest in environmental issues in recent years, interest in biomass plastics has also increased. Embodiments 14 to 28 show specific means and methods for producing resin pellets used in processing resins containing environmentally degradable components that are biodegraded in nature by the power (action) of bacteria, photodegraded by ultraviolet light, or hydrolyzed by water, and that are primarily thermovisible and thermosetting, as well as details of extrusion molding, injection molding, and other necessary equipment using these resin pellets, and means for preventing discoloration, burning, etc.

[0263] (Mixing Device) In the present invention, the device that mixes the various materials is called a "mixing device." Typical mixing devices include a tumbler, a Henschel mixer, and a rocking mixer, but any device that is designed to mix the various materials is acceptable. There are no restrictions on the means or structure. A concrete mixer can also be used. In the present invention, mixing using a tumbler is called "tumbling." It is preferable to use a weight control device, weight control feeder, weight feeder, etc., such as a Backmelter (product name), which will be shown in the embodiment described below (see Figures 45 and 46, reference numbers 187 and 188).

[0264] (Dust Explosion) Environmentally degradable components and substances such as cellulose powder, paper powder, wheat flour, bran, and wood flour are flammable fine powders, posing a risk of dust explosion. The atmosphere inside the mixing device is first purged with an inert gas, such as nitrogen gas, before the materials are placed and mixed. A specific explanation will be given using a tumbler. The air inside the tumbler is purged with nitrogen gas, and the cellulose powder, thermoplastic resin, and other additives, if necessary, are placed inside the tumbler. The tumbler is then rotated to mix the materials. The same procedure is used with a Henschel mixer; the atmosphere inside the mixer is first purged with nitrogen gas, and then the materials are placed and mixed. Nitrogen gas continues to be introduced during the mixing stage, if necessary. While a single type of environmentally degradable component may be used in the present invention, mixing several types together as needed can be expected to improve quality and provide economic benefits.

[0265] (Tumbler) Before pelletization, thermoplastic resins and environmentally degradable components are typically mixed in a tumbler. This mixture naturally contains air. Environmentally degradable components, in particular, are prone to air contamination due to their powdery nature. Naturally, air contains approximately 20% oxygen by volume (approximately 23% by weight). If pelletization is performed in this state using a kneader (including pressure kneaders), Banbury mixer, single-screw extruder, or multi-screw extruder, the oxygen oxidizes the environmentally degradable components, or some of the components within the environmentally degradable components, such as lignin, resulting in discoloration. To solve this problem, an inert gas is introduced into the tumbler to reduce the oxygen concentration. Lignin can be removed, for example, by washing with water and / or organic solvents, by boiling in water and / or organic solvents at elevated temperatures, or by steam washing. Steam washing, etc., causes the environmentally degradable components to absorb water, thereby reducing their volume. Water washing also causes water absorption. By reducing the volume in this way, operations such as melting and kneading in a tumbler or the like become easier.

[0266] (Melt-Kneading Apparatus) In this invention, the term "melt-kneading apparatus" refers to an apparatus that heats, melts, and kneads thermoplastic materials among the materials to be mixed. Examples include single-screw (one-screw) and multi-screw (e.g., twin-screw) extruders, heatable kneaders, heatable Banbury mixers, and heatable rollers. However, prior to feeding into the melt-kneading apparatus, there is a risk of dust explosions, so measures such as nitrogen gas replacement are necessary. For example, if a twin-screw extruder, whether rotating in the same direction or in a different direction, is used for melt-kneading, in addition to the risk of dust explosions, when white cellulose powder (which may contain several environmentally degradable components) colored to a desired color is mixed with a thermoplastic resin and melt-kneaded, the environmentally degradable components may discolor or burn, resulting in color problems such as failure to achieve the desired color. When colored, the intended color cannot be achieved. This is because when a thermoplastic resin is melt-kneaded in the extruder heating barrel, even if the resin used is PP, it is heated to nearly 200°C. At this temperature of 200°C, for example, if an environmentally decomposable component is used, the material will discolor to yellow or brown. In some cases, if the melt-kneading temperature is increased, the material will burn to black. This discoloration and burning problem is caused by oxygen in the air, and discoloration occurs in an atmosphere where oxygen is present. In inert gases such as nitrogen gas, carbon dioxide gas, and rare gases, discoloration is minimal, or does not occur at all.

[0267] As a means to solve this problem of discoloration, the inventors replace the inside of the hopper with nitrogen gas, for example, when using an extruder for pelletizing, sheet molding, etc. Specifically, by replacing the inside of the hopper with nitrogen gas and injecting nitrogen gas into the vent part of the extruder, nitrogen gas also enters the heating barrel, preventing discoloration.

[0268] Even when nitrogen-purged materials (mixture 001 in which the air in the gaps has been purged with nitrogen gas) are melt-kneaded using a kneader, Banbury mixer, or single- or multi-screw extruder, there is a risk of discoloration due to oxidation if oxygen enters. We now explain melt-kneading using a single- or multi-screw extruder. It is preferable to first purge the air in the hopper with nitrogen gas before placing the mixture in the extruder hopper. The material to be melt-kneaded and pelletized (tumbled and nitrogen-purged material) is placed in the hopper, and nitrogen gas is continuously introduced into the hopper. In this invention, this is referred to as sealing the hopper with nitrogen gas. Nitrogen gas is injected and sealed into the hopper from the bottom, just before the heating barrel, or within the hopper, preferably from the center of the material, as shown in Figures 45 and 46. Nitrogen gas (reference numerals 187 and 188) below the hopper is sent from the hopper into the heating barrel along with the above-mentioned mixture 001.

[0269] (Discoloration / burning) Environmentally degradable components, thermoplastic resins, etc. do not pose any problems at room temperature, but when heated to high temperatures, for example to nearly 200°C, and come into contact with air, they are oxidized by the oxygen in the air and turn yellow or brown. If the oxidation progresses further, they will turn brown. In this invention, discoloration and burning are collectively referred to as "discoloration, etc." or "discoloration / burning."

[0270] (Molding apparatus) "Molding apparatus" refers to an extruder, sheet extruder, profile extruder, injection molding machine, block molding machine, casting machine, calendar molding machine, blow molding machine, etc. Products processed using a molding apparatus are called "molded products, molded products, molded products." In the present invention, raw material pellets are also included in the molded products.

[0271] (Cooling equipment) "Cooling equipment" refers to conveyors for air-cooling the thermoplastic resin strands coming out of the extruder, water tanks for water-cooling, temperature controllers that control the temperature of the molding machine, chillers, etc. In the case of sheet molding, this also refers to conveyors, water tanks, etc. that cool the sheet.

[0272] (Molding equipment) "Molding equipment" is a general term for extruder dies, molds for casting processing, molds for injection molding processing, etc.

[0273] (Molding process) The term "molding process" as used herein refers to extrusion molding, profile extrusion molding, cast molding, injection molding, block molding, calendar molding, and other processes for producing strands or sheets. In particular, injection molding includes not only general molding processes (general molding, normal molding), but also injection foam molding using a chemical foaming agent whose properties are solid or liquid (or slurry), injection foam molding using a physical foaming agent whose properties are solid, liquid, or gas (also simply referred to as "foam molding or foam molding process"), extrusion molding, profile extrusion molding, cast molding, block molding, calendar molding, and other processes using the foaming agents. Synpress (trade name), AGI (trade name), Air Mold (trade name), and their application technologies RFM, H ２ Injection blow molding methods such as the M molding method (which are also referred to simply as "blow molding" or "blow molding methods" in the present invention), and injection pressure molding (which is also referred to simply as "pressure molding" or "pressure molding method"), in which a gas having a pressure higher than atmospheric pressure is introduced into the gap between the molten resin and the mold and pressurized by the pressure of that gas, can also be carried out using the resin of the present invention that contains environmentally degradable components.

[0274] (Inert Gas) "Inert gas" refers to a gas that contains environmentally degradable components and does not oxidize high-temperature molding materials containing thermoplastic resins when the actual temperature of the molding material is 380°C. Examples of such gases include nitrogen gas, carbon monoxide, carbon dioxide gas, hydrogen gas, gas obtained by vaporizing organic solvents, and rare gases such as helium and neon. These gases can be used alone or mixed together to form composite gases. Nitrogen gas and carbon dioxide gas are particularly useful in the present invention. Nitrogen gas, in particular, can be obtained in large quantities inexpensively using separation devices such as separation membranes and PSA, and is therefore frequently used in the present invention. In addition to combining with oxygen and being decomposed by oxygen, oxidation in the present invention also refers to the loss of electrons from the target substance.

[0275] (Gas Replacement) "Gas replacement" refers to the process of depressurizing and degassing the oxygen-containing air that has entered the equipment and / or the gaps between materials, then introducing an inert gas, such as nitrogen or carbon dioxide, under reduced pressure and then raising the pressure back to atmospheric pressure. Alternatively, instead of reducing the pressure, an inert gas can be introduced and then pressurized. For example, an inert gas with a pressure higher than atmospheric pressure can be introduced and replaced with air. This method can be performed once, but repeated several times will ensure sufficient replacement. The air in the hopper of an extruder or injection molding machine, or the air in the gaps between materials, can be reduced pressure, pressurized with the gas to be replaced, reduced pressure, and pressurized with the gas to be replaced. Equipment optimized for this method, such as a backmelter (product name) is available, making gas replacement easy. Simply drawing a vacuum (which actually means reducing the pressure) using Haruna's Ecomac (product name) is also sufficient. Alternatively, an inert gas can be reintroduced into the vacuum device. In the present invention, devices having functions such as a back melter and an Ecomac are collectively referred to as a "back melter." A back melter may be pressurized above atmospheric pressure without reducing the pressure, returned to atmospheric pressure, and then pressurized above atmospheric pressure again to replace the gas.

[0276] The mixture of environmentally degradable components and thermoplastic resin mixed in a tumbler is placed in a closed container, and a vacuum is drawn using a vacuum pump or the like. When inert nitrogen gas is poured into the reduced pressure, the air (especially oxygen) inside the tumbled material is replaced with nitrogen gas. This air-to-nitrogen gas replacement process can replace as much oxygen as possible with nitrogen gas even in one go, but if further nitrogen gas replacement is desired, it is preferable to perform the process multiple times.

[0277] (Gas sealing) "Gas sealing" means, for example, to prevent air from re-entering an apparatus after air has been expelled and replaced with inert nitrogen gas, by continuously or intermittently sending nitrogen gas into the hopper or feed screw (sub-screw) of an extruder, thereby creating an atmosphere of only inert gas inside the apparatus.

[0278] {Gas Under Pressure (GCP), GCP Method, Outer GCP} "Outer GCP" is a method used in foam molding to obtain a smooth foamed product with a clean surface free of swirl marks. Normally, air pressurized to a pressure higher than atmospheric pressure is used, but as mentioned above, using environmentally degradable components can cause significant discoloration and burning. To solve this problem, the gas used in GCP is nitrogen gas, carbon dioxide gas, etc., rather than air containing oxygen.

[0279] In a mold sealed with O-rings for PL, load-type O-rings for ejector pins, or an ejector box, the mold is pressurized with gas (typically air) above atmospheric pressure before being filled with foamable resin. The gas is then evacuated during or after filling to produce a foam-molded product with a clean, smooth surface and an internal foam layer. This process, known as GCP, involves using air as the gas, which can cause discoloration and burning. However, by pre-pressurizing the mold (this process is called "pressurization," also known as "compressed air" or "pressurizing") and using inert nitrogen gas instead of air (which contains oxygen, causing discoloration and burning), discoloration and burning can be minimized. The sealed mold is first pressurized with air, and then nitrogen gas at a higher pressure than the air is introduced into the cavity, replacing the initial air with the nitrogen gas pressure. In this case, nitrogen gas is used primarily to pressurize the cavity, while other parts of the mold, such as the space at the bottom of the insert and the inside of the ejector box, are pressurized with inexpensive air, which is more economical than pressurizing the entire sealed injection mold with nitrogen gas. Sometimes, a vacuum is used to remove the initial air, and then nitrogen gas is used again. Nitrogen gas may also be used to pressurize from the beginning. GCP is explained in PCT / JP2016 / 86380, PCT / JP2015 / 062611, and PCT / JP2020 / 015536, and the contents of these documents are used in the implementation of foam molding, GCP, blow molding, and pressure molding of the present invention.

[0280] (Fluidity support) When carbon dioxide gas is used in GCP, in addition to preventing discoloration and burning, the carbon dioxide gas enters the cavity from the leading edge of the flow of the molten resin, improving the fluidity of the molten resin. Carbon dioxide gas has a higher affinity with molten resin than nitrogen gas, and when carbon dioxide gas dissolves in it, the fluidity improves. A mixture of nitrogen gas and carbon dioxide gas is also acceptable.

[0281] Even without using a sealed mold, the mold is closed, and before filling with molten resin (which can be either foamable or non-foamable resin), nitrogen gas at a pressure higher than atmospheric pressure is introduced into the cavity to initially replace the air in the cavity with nitrogen gas, and then the molten resin is filled.In this process, the injection of nitrogen gas can be stopped before filling with the molten resin, or the injection of nitrogen gas can be continued once filling has begun and until filling is complete.

[0282] (Fluidity support and dispersion) Fluidity improvers are used to increase the fluidity of molten resin. In molding equipment, extruders, and injection molding machines, holes can be drilled in the heating barrel through which liquids that vaporize at the temperature inside the heating barrel, such as water, alcohols, water-alcohol mixtures, and other organic solvents, can be introduced and vaporized, significantly improving the fluidity of the molten resin. Naturally, increasing fluidity also improves the dispersibility of environmentally degradable components in the thermoplastic resin. Anionic, cationic, or nonionic surfactants can also be added to (used in combination with) this liquid. Commercially available dispersants are also acceptable.

[0283] In addition to the liquids mentioned above, gases such as nitrogen gas and carbon dioxide gas can be added to the molten resin to increase its fluidity. Carbon dioxide gas has a higher affinity (easier mixing) with the molten resin than nitrogen gas, so if a gas is used, carbon dioxide gas is the better choice. Solid blowing agents, such as hydrogen carbonates (typically sodium bicarbonate), azo compounds (typically ADCA), and chemical blowing agents such as nitrosated compounds (typically DPT), as well as physical blowing agents such as hollow air balloons, can also increase the fluidity of the molten resin inside the heating barrel.

[0284] To enhance the bonding strength between the environmentally degradable component and the thermoplastic resin, if the thermoplastic resin is PP, an emulsion (solvent-based emulsions are acceptable) containing maleic acid-modified PP, which has a high bonding strength with PP resin, is placed in the heating barrel in the same manner as in the liquid method described above to enhance the bonding strength between the environmentally degradable component and the PP resin. If the thermoplastic resin is a styrene-based resin such as ABS, a solution of styrene-modified acrylic resin as an emulsion or a solution of styrene-modified acrylic resin dissolved in a solvent can be used. If the thermoplastic resin is polyamide, a solution or emulsion of methoxymethylated polyamide can be used in the same manner and placed in the heating barrel. Of course, maleic acid-modified PP, styrene-modified acrylic resin, solid methoxymethylated polyamide (powder, etc.), and polyvinyl alcohol can also be mixed together. In this case, if the maleic acid-modified PP or other solid materials are used, they can be mixed in a tumbler (tumbling) before being fed into an extruder hopper or similar device.

[0285] Liquefied carbon dioxide gas can be injected into the barrel and vaporized at the temperature of the heating tube, allowing it to be used as a flow improver. Solid carbon dioxide gas (dry ice) is pelletized, and a back-melter-like device is installed in an extruder, injection molding machine, or other molding device. A mixture of dry ice, environmentally degradable ingredients, and thermoplastic resin is then placed in the heating tube and melted. During melting, the dry ice sublimes into carbon dioxide gas, which dissolves in the molten resin. As a result, the molten resin in the heating tube has dissolved carbon dioxide, improving its flowability. Dry ice can also be used as a flow improver. Other examples include substances that impart foaming properties to the molten resin in the heating tube, such as bicarbonates (salts of alkali metals such as Li, Na, and K), azo compounds such as ADCA, and nitrosated compounds such as DPT, which improve the flowability of the resin. Another method for improving flowability is to introduce gases such as MUSEL, AMOTECH, or SOFIT into the heating tube to impart foaming properties to the molten resin. Of course, flow improvers are also available.

[0286] By adding a liquid to the molten resin in the heating barrel and increasing its fluidity, the GCP pressure can be lowered. Even without a GCP (atmospheric pressure), foam-molded products without swirl marks can be obtained. By applying a resin holding pressure, foam cells can be eliminated, resulting in a molded product similar to a general molded product. In this case, if the resin is PP, for example, the liquid is not ethanol, but alcohols with a high carbon number, such as propanol, butanol, or hexanol, which have increased solubility in the molten resin. Therefore, even if the GCP pressure is low or the same as atmospheric pressure, foam-molded products without swirl marks or silver spots can be obtained. This effect has been confirmed not only with alcohols but also with alkanes.

[0287] (Embodiment 15) (Production of pellets) The particle size of the environmentally degradable component used in this fifteenth embodiment is not particularly important. It can be large or small. A mixture of large and small particle sizes may also be used. The cellulose powder (KC Flock W-100GK, W-50GK, W-400G) manufactured by Nippon Paper Industries Co., Ltd. used in the examples of the present invention is sufficient if it has an average particle size of 200 μm or less, but if improved dispersibility and uniformity (uniform dispersion) are required, a particle size of 20 μm or more but less than 50 μm is used. Cellulose powder KC Flock manufactured by Nippon Paper Industries Co., Ltd. is originally a white powder similar to shoji paper. A mixture (referred to as "Mixture 001" in this invention) of 51 wt.% of this white powder (cellulose powder) and 49 wt.% of natural-colored PP resin (Sumitomo Noblen HX101A (trade name)) was heated and melt-kneaded in a kneader (a pressure kneader manufactured by Toshin Corporation) that used an electric rod heater. The melt temperature was adjusted to below 200°C, but the mixture of the cellulose powder and PP resin turned brown (both the cellulose powder and the PP resin pellets were originally white). It was speculated that this discoloration was due to oxidation of the cellulose powder by air (oxidation by oxygen in the air).

[0288] To confirm whether the discoloration was caused by oxygen in the air, the heating section of the kneader was enclosed in a vinyl bag and inert nitrogen gas was poured inside (nitrogen gas was continuously poured in during melt-kneading in the kneader, replacing the air and sealing the resin melting environment (the atmosphere during melt-kneading) with nitrogen gas). Similarly, when the material was melt-heated at 200°C, the color was white with almost no discernible discoloration compared to the material melt-kneaded in air. This confirmed that the discoloration was caused by oxygen in the air. Although slight discoloration was observed, it was assumed to be due to air getting into the gaps between the cellulose powder and PP pellets.

[0289] When the melt-kneaded PP resin mass containing the cellulose powder was removed from the nitrogen gas atmosphere and released into the air, the surface temperature was close to 200°C, the same as during melt-kneading, and the oxygen in the air caused the surface to turn brown. This experiment demonstrated that cellulose powder is easily oxidized and discolors. However, it was confirmed that this discoloration problem can be solved by replacing the air with an inert gas such as nitrogen gas.

[0290] Conventional resin (e.g., PP resin) pellets are made by cooling strands in water and then cutting them into pellets. However, because environmentally degradable components have high water absorption, water cooling is not recommended; air cooling is preferred. A molten mass of PP resin containing cellulose powder, which had previously been melt-kneaded and not yet completely cooled and solidified, was extruded using a plunger extruder, cooled in air on a stainless steel mesh conveyor (because cellulose has high water absorption), and extruded into strands, which were then cut using a pelletizer to obtain PP resin pellets containing cellulose powder. However, because the process of forming extruded strands using the plunger was carried out in air (strand cutting, air cooling and solidification), the surface of the strands oxidized and turned brown.

[0291] It was confirmed that discoloration can be prevented by nitrogen gas substitution, as in the case of a kneader. Specifically, the conveyor is enclosed in a tunnel structure, and nitrogen gas is poured inside to replace the air with nitrogen. The strands extruded from the die are cooled by blowing nitrogen gas onto them. In this way, by substituting nitrogen gas for the air during the melt-kneading stage and the stage of pulling the strands and pelletizing them, oxidation of the cellulose powder can be prevented, and white pellets without discoloration can be obtained. While the above embodiment uses only cellulose, cellulose powder and paper powder (either from a paper mill or finely pulverized paper collected from the market) can also be used. These can also be mixed together.

[0292] (Embodiment 16) (Means for preventing oxidation = Nitrogen gas sealing) From the third embodiment, it was confirmed that discoloration of cellulose powder (due to oxidation) is caused by oxygen in the air. However, the pressurized heated kneader is a batch-type production (manufacturing) and has low productivity. To obtain pellets, continuous production using a single-screw or multi-screw extruder and a pelletizer reduces production costs and is more economical. The sixteenth embodiment shows a means for obtaining discolored pellets without oxidation using an extruder. Mixture 001 is placed in the hopper of the extruder, and the air in the hopper is replaced with inert nitrogen gas. In practice, nitrogen gas can be continuously introduced into the lower part of the hopper (preferably the pipe part connected to the heating barrel) using a thin hose. Nitrogen gas can be purchased from a commercially available cylinder, but in this case, nitrogen gas cylinders are expensive and therefore not economical. The inventors have used PSA (Pressure Swing Adsorption) or a nitrogen gas separation membrane {hollow fiber (N) sold by UBE Co., Ltd.}. ２ Nitrogen gas separated from air using a separator was used.

[0293] As mentioned above, replacing the air inside the hopper with nitrogen gas reduces the oxygen concentration, preventing discoloration due to oxidation. To prevent discoloration even further, a high-vacuum plasticizing device (Buckmelter, Bacmelter (product name)) inside the heating barrel, manufactured and sold by Meiki Seisakusho Co., Ltd. and The Japan Steel Works, Ltd. as an attachment to molding machines, can be used. Mixture 001, whose air inside the hopper has been replaced with nitrogen, is placed in the heating barrel, and before melt-kneading, a vacuum is drawn using the backmelter to suck out any air that has entered the gaps between the cellulose powder and PP resin pellets. The mixture can also be placed in the heating barrel as is and melt-kneaded.

[0294] If necessary, after drawing a vacuum, nitrogen gas can be introduced into the back melter, and the air in the gaps will be replaced with nitrogen gas. The effect of replacing the nitrogen gas can be further enhanced by using multiple back melters instead of just one.

[0295] The extruder is charged with mixture 001, whose air has been replaced with nitrogen gas, and melt-kneaded. In the case of an extruder, to stabilize the amount of material being charged, small sub-screws (feed screws) are installed above the heating barrel, below the hopper, and between the heating barrel and hopper to stabilize the amount being charged into the heating barrel. In this case, it is advisable to also replace the inside of the sub-screw with nitrogen gas. This is necessary and recommended to prevent discoloration, etc.

[0296] The extruder can be a single-screw (one screw) or a multi-screw (e.g., twin-screw) extruder with high mixing capacity. In the case of a multi-screw extruder, the screws can rotate in the same direction or counter-rotate. The extruder's heating barrel is equipped with a vent. This vent is also covered and filled with nitrogen gas to seal the vent (replace air with inert nitrogen gas). After melting and mixing, the material is extruded through a die to form strands. A stainless steel mesh conveyor belt is used for cooling and solidification. During the cooling and solidification stage, to prevent discoloration due to oxidation on the strand surface, nitrogen gas substitution (replace air with inert nitrogen gas, replacing oxygen in the air with nitrogen gas) is also used to prevent surface discoloration due to oxidation of the strands emerging from the die, as explained above in the case of pellets obtained using a kneader. Once cooling and solidification are complete, the temperature drops and the material is pelletized (cold cut). By reducing the oxygen concentration in the air to nearly zero, white pellets can be obtained without discoloring the cellulose powder. By adding pigments and dyes during the pellet manufacturing process, pellets containing cellulosic powder in a variety of colors can be obtained. PP does not oxidize at a melting point of 200°C. Therefore, it has been confirmed that PP does not discolor or burn at around 200°C.

[0297] Using a dulmage screw in the extruder to enhance mixing performance improves the dispersibility of the environmentally degradable components in the thermoplastic resin. Adding a vaporizable liquid to the molten resin in the heating barrel after melt mixing, as described in Patent Publication PCT / JP2015 / 062611, reduces the melt viscosity of the molten resin in the extruder heating barrel, improving the mixing of the cellulose powder and the PP resin and improving dispersibility, rather than the foaming purpose described in Patent Publication PCT / JP2015 / 062611. Since foaming is not the objective, the amount of ethanol added should be at least 1 part, preferably at least 3 parts, per 100 parts of molten resin containing the environmentally degradable components. Suitable vaporizable liquids include alcohols such as ethanol and propanol, water, and mixtures of water and alcohols. Methanol can be used, but is not recommended due to its toxicity. Its use is discontinued in this invention. The dyes in this liquid can be added to color the pellets. Liquid injection is not limited to one location, but can be multiple locations. Solutions containing alcohol or dyes or pigments can also be injected. To enhance the bonding strength between the cellulose powder and the olefin-based resin PP and increase the strength of the final molded product, an emulsion-type solution of maleic acid-modified PP (model DB-4010 {Arrowbase (product name}, sold by Yuichika Co., Ltd.)) can be injected to strengthen the bonding strength at the interface and boundary between the cellulose and PP. Naturally, white inorganic substances such as titanium oxide, alumina, and magnesia can be added to further whiten the mixture. Plasticizers, preservatives, antifungal agents, dispersants, etc. can be used as needed. If these substances are solid, they can be mixed in appropriate amounts with Mixture 001. Solutions using organic solvents such as alcohol can be injected into the heating barrel using the liquid injection device described above (Patent Publication PCT / JP2015 / 062611), as shown in Figures 1, 4, and 19.

[0298] (Embodiment 17) (Injection Molding) This section describes a method for preventing oxidation of cellulose powder when the cellulose powder-containing pellets 001 obtained in the third and fourth embodiments are injection molded using the mixture 001. As with the pellets 001, nitrogen substitution and nitrogen sealing can prevent discoloration and burning during injection molding. First, the hopper of the injection molding machine is purged with nitrogen gas. The substitution method is the same as the nitrogen substitution method used in the hopper when pellets 001 are produced using an extruder in the pellet production process. The hopper is purged with nitrogen, and then the pellets are plasticized in the heating barrel of the injection molding machine. The injection molding machine of this fifth embodiment is equipped with the back melter described above. Some of the air in the gaps between the pellets is purged with nitrogen gas, and the pellets 001 in the hopper are then fed into the back melter. The back melter is evacuated, and the pellets are fed into the heating barrel, where they are melted, plasticized, and kneaded. After evacuating the back melter, nitrogen gas may be introduced into the back melter again. Naturally, a single back melter is sufficient, but using multiple back melters in series can further increase the nitrogen gas replacement rate. In this way, the gaps between the pellets 001 are replaced with nitrogen gas, so discoloration and burning caused by oxygen do not occur during the plasticization and melting / kneading stages.

[0299] The pellets 001 plasticized in the heating barrel of the injection molding machine are then filled into the mold. However, because air, or actually oxygen in the air, is present in the mold cavity, there is a risk of discoloration and burning in the resulting molded product. Increasing the injection speed increases discoloration and burning due to adiabatic compression. To solve this problem, the cavity is purged with an inert gas, such as nitrogen gas. A specific method for nitrogen gas replacement in the cavity is described below. The mold used is equipped with gas injection pins and gas pressurization pins (see Figures 52, 53, and 54 in Patent Publication (PCT / JP2016 / 86380)) from either the fixed side, the movable side, or the spool runner (or multiple pins). When the mold is closed, nitrogen gas is blown into the mold cavity by opening the valve (reference number 14) in Patent Publication (PCT / JP2016 / 86380) in Figure 1. Once the air in the cavity has been replaced with nitrogen gas, the molten resin of the pellets 001 is injected (filled) into the cavity. Once the molten resin has cooled and solidified, the mold is opened and the molded product is removed, and a beautiful white injection molded product without discoloration or burning is obtained, which has been injection molded using pellets 001 manufactured using mixture 001.

[0300] (Embodiment 18) Pellet 001 contains 51 wt.% cellulose powder, resulting in significantly lower fluidity than pellets made of 100% PP resin. Furthermore, due to concerns about discoloration and burning of the cellulose powder, the resin temperature during molding cannot be kept too high. Therefore, as an application of the liquid-based foam molding method described in Patent Publication (PCT / JP2015 / 062611) to increase the fluidity of molten resin, alcohols, water, or a mixture of alcohols and water are added to the molten resin in the heating barrel to improve its fluidity. Since the amount added is not foam molding, an amount several times greater than that used for foam molding is added to increase the fluidity and then injected into a cavity purged with nitrogen gas. Subsequently, the resin is held under pressure to squeeze out the liquid. This method uses a blowing agent to prevent foaming by applying a holding pressure. Naturally, due to the risk of discoloration and burning, the hopper and cavity are purged with an inert gas and sealed with an inert gas.

[0301] While we previously showed the use of liquids such as alcohol as a flow improver for thermoplastic resins (a method of injecting them into the heating barrel), the same flow support effect can be expected by using gases such as nitrogen gas or carbon dioxide pressurized to a pre...

Claims

In the process of feeding a molding material mainly composed of a thermoplastic resin into a molding machine heating barrel and melt-kneading (including plasticizing and metering) the molding material, In the stage of melt-kneading the molding material, a liquid is poured into the molding resin in the heating cylinder, The liquid evaporates into vapor at the temperature of the heating barrel and the temperature of the molten resin. a step of pressurizing and dissolving and / or finely dispersing the vapor of the liquid by a physical force such as screw rotation to increase the fluidity of the molten resin; and filling the molten resin having improved fluidity into a cavity. In the method according to claim 1, a resin holding pressure is applied to the molten resin filled in the cavity by using a molding machine screw during and after the filling of the molten resin, and increasing the density of the molten resin filled in the cavity. In claim 1 or / and claim 2, a gas having a pressure greater than atmospheric pressure is injected into the molten resin filled in the cavity through a nozzle, or / and a spool runner, or / and directly into the molten resin filled in the cavity, and a step of pressurizing the molten resin from inside the molded article using the pressure of the gas to increase the density of the resin. In claim 1 or / and claim 2, a gas having a pressure greater than atmospheric pressure is introduced outside the molten resin filled in the cavity (a gap between the resin and the mold, outside, outside), The method for manufacturing a resin molded product comprises a step of applying pressure to the molten resin from outside the molded product using the pressure of the gas to increase the transferability to the mold, and a step of increasing the density of the resin. In claim 1 or / and claim 4, a sealed mold is used, and the inside of the mold is pressurized with gas that has been previously pressurized to a pressure higher than atmospheric pressure, and 5. The method for producing a molded article according to claim 1, wherein the molded article is filled with a molten resin whose fluidity has been increased by a liquid.

4. The method for producing a hollow molded product according to claim 3, wherein a sealed mold is used, and the mold cavity is pressurized in advance to atmospheric pressure or higher, and the resin whose fluidity has been increased by using a liquid is filled into the mold cavity.

5. The method for producing a pressure-molded product according to claim 4, wherein a sealed mold is used, and the mold cavity is pressurized to atmospheric pressure or higher beforehand, and the resin whose fluidity has been increased by using a liquid is filled into the mold cavity. The fluidity of the molten resin in the heating cylinder is increased by adding gas, if necessary, to the liquid in the heating cylinder after heating and melting. a step of injecting a liquid to reduce the melt viscosity of the molten resin in the heating barrel and improve its fluidity; and injecting a gas through a separately provided injection port into the molten resin whose viscosity has been reduced and whose fluidity has been improved by the liquid. The melt-kneading screw used in the present invention is a melt-kneading screw that injects liquid and then gas into resin and has a backflow prevention ring provided behind the liquid injection port provided in the heating barrel. The thermoplastic resin used in any one of claims 1 to 9 is a molding material for molding processing, the main component of which is a thermoplastic resin blended with inorganic and / or organic resin additives. A resin molded product molded using the processing method and molding material according to any one of claims 1 to 9. A mold device used when performing molding using the processing method and molding material according to any one of claims 1 to 9. A molding apparatus used when performing molding using the processing method and molding material according to any one of claims 1 to 9.

Images