Foaming Agent Masterbatch

Abstract

[Problem] To provide a foaming agent used to manufacture a foaming resin, an apparatus, a molding die, a molding apparatus, a means for increasing a foaming ratio, and a means for increasing the suitability of coating in a manufacturing method for obtaining molded products having a foam layer therein. [Solution] Molded products having a good appearance are obtained when carrying out manufacturing using a resin exhibiting compatibility with items in which a carrier resin is to be mixed, said carrier resin to be used to manufacture a foaming resin master batch. When inorganic baking soda is used in a foaming agent, sodium carbonate in a foam residue, which remains in molded products after an effervescent gas is generated due to decomposition of the foaming agent, reduces adhesion of a coating film. Thus, when acid washing is conducted in advance to remove the sodium carbonate, a suitable coating is satisfied. When performing GCP, the thickness of a surface skin layer is altered by the molding die surface temperature. Although a means in which heated steam is used for increasing the temperature of molding dies is common, in the present invention, a means for heating a magnetic fluid (liquid) by high-frequency induction is used, thereby inexpensively providing high heating efficiency and a stable increase in the temperature of a molding die. When performing composite molding and back molding of a means for obtaining molded products having a high foaming ratio, the molding products separate from the immobilization side. The present invention provides a means for solving this separation problem by using a gas.

Description

[Technical field]

[0001] The present invention relates to a foaming agent used to obtain foam molded products, a manufacturing method for foam molded products, a coating method for foam molded products, and a manufacturing means and manufacturing apparatus for the foam molded products that are the base materials for these products. [Background technology]

[0002] Patent Document 1 describes a foam molding method in which a molding material consisting of a resin (plastic) and a foaming agent is shot into a mold in which an insert is placed, leaving an unfilled portion, and the unfilled portion is filled by the expansion force caused by the foaming of the foaming agent. The resin consists of a base resin and a low molecular weight resin of the same type as the base resin but with a lower molecular weight than the base resin. Patent document 2 explains the Gas Counter Pressure (GCP) method as a means of suppressing swirl marks (foam stripe patterns) that occur on the surface during foam molding, as well as the mold structure and use of a U-shaped O-ring. Reference 3 contains a description of pretreatment of bumpers for vehicle parts, but does not specify that GCP is used in foam molding with baking soda or a foaming agent containing baking soda to clean the surface of foam molded products (objects, molded products, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 08-103919 [Patent Document 2] Japanese Patent Application Publication No. 11-216748 Document 3

[0004] Coating Engineering: Vol. 27 No. 11 (1992) "Low-pollution surface treatment of plastic bumpers" by Yuichi Yoshida; pages 505(21) to 511(27) DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0005] The object of the present invention is to obtain foam molding with a beautiful surface, and to paint the foam molding and ensure sufficient adhesion of the paint film. [Means for solving the problem]

[0006] (Configuration of claim 1) The first invention related to claim 1 pressurizes the inside of a sealing mold to 0.6 MPa or more, and while maintaining that state, begins venting the compressed air when 90% or more of the molding space has been filled with foamable resin.

[0007] (Function of claim 1) In the first invention according to claim 1, when a GCP device is connected to each of L1, L2, and L3 as shown in FIG. 38, by first exhausting either L1 or L3 (generally L1, which has a larger amount of compressed air, is exhausted first), and then exhausting L2, discoloration and burning due to adiabatic compression can be prevented. When one GCP device is connected to L1, L2, and L3, exhaust is started when the volume reaches 90% all at once.

[0008] (Effect of claim 1) The first invention according to claim 1 makes it possible to produce a foamed molded product that is free from short molds, discoloration, and burning caused by compressed air by venting the compressed air when the molding space is filled with the foamable resin to 90% or more by volume.

[0009] (Explanation of claim 1) Compared to normal molding, the amount of gas in the molding space in GCP is greater by the amount of pressure. This compressed air is an effective means of suppressing foaming on the surface during foam molding, but it can cause obstructions, short molds, discoloration, and burns when filling the foamable resin into the molding space. The force of filling the resin moves it to spaces other than the molding space. Even if the foamable resin is not filled completely into the molding space, or if it is vented at an early stage, depending on the shape of the product, foaming on the surface and swirl marks will not occur.

[0010] (Effect of claim 2) In the second invention according to claim 2, the inside of the sealing mold is pressurized, and the exhaust of the pressurized air begins when the foamable resin is filled into the molding space.

[0011] (Function of claim 2) In the second invention related to claim 2, the exhaust of compressed air begins after the molding space is filled to the brim with foamable resin, thereby eliminating swirl marks and producing a foam-molded product with a smooth surface and beautiful appearance.

[0012] (Effect of claim 2) In the second invention according to claim 2, exhaust begins after the molding space is completely filled with the foamable resin, so that swirl marks on the surface can be suppressed. The timing of exhaust is during the filling of the foaming resin into the molding space or after the molding space is completely filled. The timing of exhaust is changed depending on the shape of the molded product, so it is possible to manufacture foamed molded products without swirl marks, short molds, discoloration, or burns.

[0013] (Explanation of claim 2) As shown in Figure 38, if a GCP device is connected to each of L1, L2, and L3, first vent L1 or L3 (generally L1, which has a larger amount of compressed air, is vented first), followed by L2. The timing of venting is staggered. The compressed air in the molding space is pushed to other places (L1, L3, GCP device, GCP hose) by the force of filling the resin, so the pressure on the tip of the foamable resin being filled does not become very high. As a result, a foam-molded product without swirl marks and without short molds is obtained. In this invention, the transfer of compressed air in the molding space to other places by the force of filling is called "transfer".

[0014] (Configuration of claim 3) The third invention according to claim 3 provides a means for increasing the expansion ratio of the foam-molded product by retracting the mold simultaneously with the start of exhausting the GCP, and performing mold back and / or core back.

[0015] (Function of claim 3) The third invention according to claim 3 uses GCP to perform foam molding with a smooth surface, and then performs mold back and / or core back when the inside has not yet completely cooled and solidified, thereby producing a molded product with a smooth surface without swirl marks and a high expansion ratio. Raindrop can also be eliminated by simultaneously evacuating the GCP and performing mold back and / or core back.

[0016] (Effect of claim 3) According to the third invention, since an expansion-molded product having a high expansion ratio can be obtained, it has an economic effect such as reducing material costs.

[0017] (Explanation of claim 3) The third invention according to claim 3 performs mold back and / or core back simultaneously with the start of exhaust of the GCP, and a gas vent is created by opening the PL in addition to the exhaust valve of the GCP, and the compressed air is exhausted all at once, so that a foam-molded product with a beautiful appearance can be obtained without raindrops caused by compressed air.

[0018] (Configuration of claim 4) Mold back and / or core back are performed on the fixed side of the mold.

[0019] (Function of claim 4) It is also possible to perform mold back and / or core back on the fixed side of the mold, which, like the movable side, produces foamed products with a high expansion ratio.

[0020] (Effect of claim 4) Depending on the structure of the mold (e.g., a three-plate mold with a stripper plate), performing mold back on the fixed side and / or core back on the fixed side can simplify the mold mechanism.

[0021] (Explanation of claim 4) A mechanism such as a spring is placed in the mold, and when the molding machine (in this invention, "molding machine" mainly includes injection molding machines and machines that perform processes similar to injection molding machines) die plate is retracted, a mechanism is provided in which the fixed side of the mold retracts when the mold is opened.

[0022] (Configuration of claim 5) The fifth invention according to claim 5 provides a mechanism in which the mold and molding machine are provided with a mechanism in which, when the molding machine die plate is retracted and the mold is opened, the movable and fixed molds are retracted to perform mold back and / or core back.

[0023] (Function of claim 5) According to the fifth invention related to claim 5, the movable side and the fixed side are molded back and / or cored back, so that the expansion ratio can be further increased.

[0024] (Effect of claim 5) The fifth invention according to claim 5 has a mold back and / or core back on the movable side and fixed side, and can obtain a molded product with a higher expansion ratio than when only one side is used.

[0025] (Explanation of claim 5) Mold back and / or core back are performed on both the movable and fixed sides. The backing up can be done simultaneously, but there may also be a time lag.

[0026] (Configuration of claim 6) The GCP is evacuated and the inside of the seal mold is vacuumed at the same time as the mold bag and / or core bag are performed. The compressed air trapped in the gap between the resin and the mold in the molding space L2 is vacuumed.

[0027] (Function of claim 6) According to the sixth invention, in order to eliminate raindrops and obtain a foam molded product with a beautiful appearance, the compressed air that has entered the resin and the mold is rapidly exhausted. The exhaust speed can be further increased by further vacuuming.

[0028] (Effect of claim 6) The sixth invention according to claim 6 is carried out simultaneously with mold back and / or core back before the surface of the molded product is cooled and solidified, improving transferability to the mold and eliminating raindrop.

[0029] (Explanation of claim 6) The sixth invention according to claim 6 performs mold back and / or core back after exhausting the GCP, and vacuums the compressed air that has entered the gap between the resin and the mold, thereby obtaining a molded product free of raindrops.

[0030] (Configuration of claim 7) The vacuum is applied after a delay from the mold back and / or core back.

[0031] (Function of claim 7) A delay is provided for the evacuation, so that the evacuation is performed after the mold has been fully evacuated.

[0032] (Effect of claim 7) By using a vacuum, it is possible to obtain foam moldings with a high expansion ratio that are free of raindrops and have a beautiful appearance.

[0033] (Explanation of claim 7) The seventh invention according to claim 7 evacuates the GCP, mold-backs and / or core-backs, opens the gas vent, and draws a vacuum. The effect of vacuuming is greater because the gas vent is expanded by expanding the mold. Moreover, since the vacuuming is done after sufficient evacuation, the effect of vacuuming (reducing pressure) is great. The vacuuming equipment used can be smaller because the amount of gas used for vacuuming can be reduced. This method allows for the production of molded products with a beautiful appearance, free from raindrops, even on glossy surfaces, without the need for texture processing.

[0034] (Configuration of claim 8) The air pressure inside the seal mold is exhausted and vacuum drawing begins at the same time.

[0035] (Function of claim 8) It uses a vacuum to eliminate raindrops caused by compressed air.

[0036] (Effect of claim 8) The vacuum is used to produce beautiful foam molded products that are free of raindrops.

[0037] (Explanation of claim 8) The eighth invention according to claim 8 performs evacuation of the GCP and vacuuming at the same time without mold back and / or core back. In order to eliminate raindrop and obtain a beautiful molded product, it is better to apply embossing to the surface of the mold.

[0038] (Configuration of claim 9) Vacuuming inside the sealing mold and GCP device begins after a delay.

[0039] (Function of claim 9) It uses a vacuum to eliminate raindrops caused by compressed air.

[0040] (Effect of claim 9) This produces beautiful foam-molded products that are free of raindrops.

[0041] (Explanation of claim 9) Vacuuming is performed after a delay from the exhaust of the GCP. When performing the vacuuming of claims 6 to 9, the mold seal structure in which the ejector pins are sealed as shown in Fig. 11 has a smaller volume to be vacuumed, and therefore the vacuuming action and effect is greater. When performing vacuuming without mold backing, etc., if a beautiful appearance without raindrops is required, it is better to apply a textured finish to the surface of the mold where the appearance is required.

[0042] (Configuration of claim 10) The tenth invention according to claim 10 is characterized in that a program is incorporated in the PLC of the molding machine to control the GCP device used in foam molding, the device for injecting gas or liquid or both into the heating barrel, the blow molding device for performing blow molding, and the pressure molding device for performing pressure molding, and to issue operation commands to each of them.

[0043] (Function of claim 10) The PLC of the molding machine already has programs written into it for devices that are connected to the outside world to perform operations such as GCP devices, liquid injection devices, blow molding, and compressed air molding, making it easy to connect and operate the devices.

[0044] (Effect of claim 10) In the tenth invention related to claim 10, the programs for the GCP device, the device for injecting liquids, and the device for performing blow molding and compressed air molding are written into the PLC of the molding machine, so there is no need to prepare an external controller, and no additional capital investment is required.

[0045] (Explanation of claim 10) The PLC program for the molding machine contains programs that issue commands for the operation of the GCP device, the device for injecting liquids, and the device for performing blow molding and compressed air molding.

[0046] (Configuration of claim 11) The closing of the mold is used as a start signal (a signal indicating completion of mold clamping, an LS signal attached to the mold, etc.), which opens the air pressure valve (number 46) of the GCP device and pressurizes the inside of the mold. The time for air pressure is entered into the program in the PLC beforehand. A program is written into the PLC of the molding machine that issues a command to the molding machine to start injecting the foamable resin when the time is up.

[0047] (Function of claim 11) The operation of the GCP device (compressed air) is initiated by a program in the molding machine's PLC.

[0048] (Effect of claim 11) There is no need to prepare a separate controller for the operation of the GCP device, as the program is built into the PLC in the molding machine. It is designed to check the mold closing and use a timer to apply pressure inside the mold, so there is no need to prepare a separate controller and the operator does not need to move.

[0049] (Explanation of claim 11) The GCP unit's air compression operation is built into the molding machine's PLC. Air compression inside the mold and the start of injection are controlled by a timer.

[0050] (Configuration of claim 12) The release of compressed air from within the mold (opening of valve no. 51) is performed by a program within the molding machine PLC.

[0051] (Function of claim 12) The molding machine's PLC has a built-in program that commands the GCP device to operate (open the valve and vent).

[0052] (Effect of claim 12) In the twelfth invention related to claim 12, the program for operating the GCP device is incorporated into the PLC of the molding machine, so that the operator can check the contents of the program and operate it using only the same screen.

[0053] (Explanation of claim 12) The exhaust from inside the mold (opening of valve No. 51) is performed by a program built into the PLC inside the molding machine. There is no need to invest in a new controller to send operational commands to the GCP device.

[0054] (Configuration of claim 13) The molding machine's PLC has a built-in program that performs mold back and / or core back after exhausting the compressed air.

[0055] (Function of claim 13) The PLC of the molding machine is programmed with programs for operating the GCP device and for mold back and / or core back, so these operations are carried out according to commands from the molding machine.

[0056] (Effect of claim 13) In the thirteenth invention according to claim 13, the mold back and / or core back programs are built into the PLC of the molding machine. There is no need to prepare a separate controller.

[0057] (Explanation of claim 13) The PLC of the molding machine is programmed with the operation of the GCP device and the mold back or / and core back programs, which are used to carry out the foam molding.

[0058] (Configuration of claim 14) The molding machine's PLC has a built-in program that performs vacuum pulling after releasing the compressed air, mold backing and / or core backing.

[0059] (Function of claim 14) The molding machine's PLC controls the operation of the GCP device and mold back or / and core back, and then vacuuming is performed by commands from the molding machine.

[0060] (Effect of claim 14) In the 14th invention according to claim 14, a program for evacuation after mold back and / or core back is built into the PLC of the molding machine. There is no need to prepare a dedicated controller.

[0061] (Explanation of claim 14) The PLC of the molding machine is programmed with programs for the operation of the GCP device, mold back and / or core back, and vacuum drawing, and foam molding is carried out by these programs.

[0062] (Configuration of claim 15) In the fifteenth invention according to claim 15, the L / D (value obtained by dividing the length by the diameter) of a screw in a heating barrel of a molding machine used for foam molding is 15 or more.

[0063] (Function of claim 15) In the fifteenth invention according to claim 15, a screw having an L / D ratio of 15 or more is used to plasticize a resin, and a foaming gas is pressurized, dissolved, and finely dispersed therein.

[0064] (Effect of claim 15) The fifteenth invention according to claim 15 is a high-mixing screw having an L / D ratio of 15 or more, so that the foaming gas can be pressurized, dissolved, and finely dispersed in the plasticized resin in an optimal manner.

[0065] (Explanation of claim 15) In foam molding, high kneading ability is required for pressurized dissolution and fine dispersion of the foaming gas in the molten resin in the heating barrel at the stages of plasticization and metering. When a highly mixed material with an L / D ratio of 15 or more is used and the flights are double-flighted and / or a dalmage is provided to achieve high mixing, the foaming gas is sufficiently pressurized and dissolved and finely dispersed, so that the resulting foamed molded product forms fine foam cells.

[0066] (Configuration of claim 16) In the sixteenth invention according to claim 16, the foaming gas is pressurized, dissolved, and finely dispersed by applying a high back pressure to the plasticizer. The back pressure during plasticization in foam molding, which is applied by the plasticized molten resin in the heating cylinder, is desirably 5 MPa or more.

[0067] (Function of claim 16) Since plasticization (melting, kneading, metering) is performed by applying a high back pressure of 5 MPa or more, the foaming gas is uniformly pressurized and dissolved, resulting in a foamable resin with uniform fine dispersion.

[0068] (Effect of claim 16) The resin is weighed, heated and melted while applying a high back pressure of 5 MPa, and then decomposed. The resin melted in the heating barrel has the foaming gas uniformly pressurized and dissolved, making it into a foamable resin with foaming properties suitable for finely dispersed foam molding.

[0069] (Explanation of claim 16) The back pressure is increased by about 5 MPa while plasticizing. During this process, the nozzle drips, so Attach a shut-off nozzle to the nozzle. The metering should be completed before the next injection (filling). If the metering is completed before the next injection (filling), the foaming gas will start to condense inside the heating barrel, so the metering may be delayed. In some cases, back pressure may be continued even after the weighing is completed (back pressure block).

[0070] (Configuration of claim 17) In order to reduce the pressure of the foamable resin filled in the molding space, immediately after the foamable resin is filled, a delay time is provided for sucking it back.

[0071] (Function of claim 17) By sucking back the resin, the pressure of the resin filling the molding space drops suddenly, making it easier for the resin to foam.

[0072] (Effect of claim 17) The expansion ratio can be increased by sucking back, resulting in foamed molded products with a high expansion ratio.

[0073] (Explanation of claim 17) The foaming resin filling the molding space is lowered in pressure by sucking back, making foaming easier. The pressure of the I-GCP is also reduced, allowing the internal foaming area to become larger.

[0074] (Configuration of claim 18) In order to reduce the pressure of the foamable resin filled in the molding space, immediately after the foamable resin is filled, bleeding is performed with a delay time.

[0075] (Function of claim 18) By allowing the resin to breathe, the pressure of the molten resin drops rapidly, making it easier to foam.

[0076] (Effect of claim 18) The foaming ratio can be increased by breathing.

[0077] (Explanation of claim 18) Breathing reduces the pressure of the foamable resin filled in the molding space, making it easier to foam. It can also be used in combination with suck back. It also reduces the pressure of the I-GCP, making the internal foam area larger.

[0078] (Configuration of claim 19) To adjust the temperature of the mold, polyhydric alcohol is used, which has a high boiling point, is non-toxic, and can be easily washed with water. Heating is performed using induction (electromagnetic induction) heating, which heats the internal metal balls and powder, and then the liquid is heated by that temperature.

[0079] (Function of claim 19) This shows a method of heating using induction heating. A liquid with a large heat capacity is used.

[0080] (Effect of claim 19) When using heated steam, the highest temperature that can be achieved is about 130°C even under pressure, and since it is a gas, it has a small heat capacity. On the other hand, when using polyhydric alcohol, it is a liquid and has a large heat capacity. The polyhydric alcohol glycerin has a high boiling point and is easy to use.

[0081] (Explanation of claim 19) In foam molding using GCP, if the surface temperature of the mold is raised, the amount of raindrops increases. On the other hand, if the surface temperature of the mold is raised, the skin layer (non-foamed layer on the surface) becomes thinner, the mold transferability improves, and the appearance is beautiful (however, raindrops occur frequently). Therefore, if the compressed air is exhausted, mold backing and core backing are performed, and a vacuum is drawn, raindrops can be eliminated even if the surface temperature of the mold is raised. If this method is used, even with composite materials containing glass fiber, if the surface temperature of the mold is raised above the glass transition point (Tg) during molding, beautiful foam molded products of composite materials such as glass fiber with little or no glass floating can be manufactured.

[0082] (Configuration of claim 20) The twentieth invention relating to claim 20 relates to a master batch of a foaming agent which comprises a resin to be molded, a powder of the foaming agent, and a varnish which is compatible (miscible) with the resin to be foamed, and the foaming agent is supported on the surface of pellets of the resin to be molded using the varnish.

[0083] (Function of claim 20) The twentieth invention according to claim 20 is a conventional method for producing a foaming agent master batch, which involves heating and melting the resin to be molded, adding foaming agent powder therein, and melt-kneading the resulting mixture. However, depending on the type of resin, production can be difficult if the melting temperature is higher than the decomposition temperature of the foaming agent. The method of applying a varnish that is compatible with the resin to be foamed to the surface of the pellets uses a low temperature for application (the solvent in the varnish evaporates and the foaming agent powder dries to the surface of the pellets), so production can be done regardless of the melting temperature of the resin to be molded when making the foaming agent master batch.

[0084] (Effect of claim 20) In the twentieth invention according to claim 20, since the resin is not heated and melted, there is no thermal degradation of the resin. The thermal energy required for production is small. There are economical effects such as not needing to use large-scale facilities (equipment, space, etc.).

[0085] (Explanation of claim 20) In the conventional manufacturing method of the master batch of the foaming agent, the carrier resin of the master batch is heated and melted with an extruder or kneader, and the foaming agent is added thereto and pelletized. However, when the melting temperature of the resin is higher than the thermal decomposition temperature of the foaming agent, this melt kneading manufacturing is difficult. In the third invention according to claim 3, the resin pellets (the properties are not limited to pellets, but may be bulk) and the foaming agent powder are mixed and heated, while adding varnish that is compatible (miscible) with the resin to be foamed little by little, the solvent in the varnish is evaporated, and the foaming agent powder is supported on the surface of the pellets (bonded with the resin in the varnish). Since the resin is not melted and heated, there is no thermal deterioration of the resin, and the foaming agent is below its decomposition temperature, making it possible to manufacture the foaming master batch without any decomposition of the foaming agent. There is no need for large-scale equipment, and production can be done with inexpensive, small, and simply constructed equipment such as a rocking mixer as shown in the example. It is best to produce master batches of the foaming agent, foaming assistant agent, and foam nucleating agent separately and then mix the master batches to create the optimal mixture, but it is also easy to produce a foaming agent master batch by mixing them together. Also, unlike conventional melt kneading methods, it is possible to produce a foaming agent master batch with a high concentration of foaming agent (if the loading is repeated, naturally a large amount of foaming agent powder will be loaded).

[0086] (Configuration of claim 21) The twenty-first invention according to claim 21 is a varnish used in the manufacture of a master batch of a blowing agent for the foaming of resins to be foamed, such as AS, ABS, and resins mainly composed of these, which is prepared by dissolving homogeneous AS and ABS in an organic solvent, such as MEK, and adding toluene, etc., as necessary. This varnish is used to support pellets of AS, ABS, etc., to manufacture a master batch of the blowing agent.

[0087] (Function of claim 21) The 21st invention relating to claim 21 is characterized in that the varnish used in manufacturing the master batch of the foaming agent is composed of AS in the resin to be foamed and ABS to be foamed, so that no foreign materials are introduced into the foamed product, eliminating problems such as deterioration of physical properties.

[0088] (Function of claim 21) The 21st invention according to claim 21 is to manufacture a master batch of a foaming agent, in which the resin to be foamed is AS, ABS, or a resin mainly composed of these, and since AS and ABS varnishes, which are compatible (miscible), are used, there is no problem of deterioration of physical properties due to the intrusion of different materials. Since the manufacture of AS and ABS varnishes is simple and inexpensive, the master batch of a foaming agent manufactured using these materials is inexpensive and does not increase the manufacturing cost of foam-molded products.

[0089] (Explanation of claim 21) In the twenty-first invention according to claim 21, AS and ABS are dissolved in a solvent to produce a varnish. A foaming agent powder is supported on the surface of the pellets of AS and ABS using the varnish. Since AS and ABS are easily dissolved in solvents, it is also possible to mix AS or ABS pellets with powdered foaming agent, and add only an organic solvent, such as MEK, to support the foaming agent on the surface of the AS or ABS pellets, instead of using varnish.

[0090] (Configuration of claim 22) The twenty-second invention according to claim 22 uses a varnish in which AS and ABS are dissolved as an emulsion or suspension for carrying.

[0091] (Function of claim 22) The twenty-second invention according to claim 22 uses an emulsion or suspension system, so there is little odor from the solvent and the working environment is not deteriorated.

[0092] (Effect of claim 22) The 22nd invention according to claim 22 is an environmentally friendly manufacturing method that uses an emulsion or suspension system, which does not deteriorate the working environment and can comply with VOC regulations in Europe and other places.

[0093] (Explanation of claim 22) The 22nd invention according to claim 22 uses a varnish dissolved in a solvent in the 21st invention. Solvents are flammable and have a strong odor, so care must be taken when working with them. A small amount of solvent is used to produce a varnish, which is then used as an emulsion or suspension system with water or the like to support the foaming agent powder on the surface of the resin pellets to be foamed. In the twenty-second aspect of the invention, an emulsion or suspension type material may be used in combination with a varnish dissolved in a solvent. The master batch of the blowing agent described in claims 4 and 5 can be used with AAS, ASA, AES, and ACS in addition to AS and ABS. Of course, AAS and the like can also be used to make a varnish.

[0094] (Configuration of claim 23) The 23rd invention according to claim 23 changes the resin to be foamed in the 4th invention from AS and ABS to PS, HIPS, or modified PPO(E), and therefore the varnish used is PS or HIPS, which is compatible with these resins.

[0095] (Function of claim 23) The 23rd invention relating to claim 23 uses a varnish in which PS or HIPS, which is compatible (miscible) with the resin to be foamed, is dissolved in an organic solvent such as MEK, just like the AS and ABS, so that a master batch of the foaming agent can be produced cheaply and easily.

[0096] (Effect of claim 23) In the 23rd invention according to claim 23, the resin to be foamed is PS, HIPS or modified PPO(E), the carrier resin of the master batch of the blowing agent (actually pellets) is PS or HIPS, the resin to be foamed is the same quality PS or HIPS, and the resins constituting the master batch at the time of foaming are PS or HIPS, which are sufficiently compatible (soluble) with PPO(E). If a deterioration in physical properties is a concern when using modified PPO(E) for the foaming agent, modified PPO(E) pellets can be used to manufacture the master batch of the blowing agent.

[0097] (Explanation of claim 23) The 23rd invention according to claim 23, in the case where the resin to be molded is a polymer blend or polymer alloy of PS, HIPS, or / and HIPS mixed with PPO(E), produces a master batch of the foaming agent by supporting the resin using PS or HIPS of the same quality as these resins, or a compatible PS or HIPS varnish.

[0098] (Configuration of claim 24) In the 24th invention related to claim 24, a master batch of a blowing agent used in foam molding of PS, HIPS or modified PPO(E) is prepared by dissolving PS or HIPS, which is compatible (miscible) with pellets of the resin to be foam molded, in a solvent, and supporting this in the pellets of PS, HIPS or modified PPO(E) to be molded as an emulsion or suspension system.

[0099] (Function of claim 24) The 24th invention relating to claim 24 uses an emulsion or suspension type resin varnish that is compatible (soluble) with the resin to be foamed in order to manufacture the master batch of the foaming agent used, which has the effect of not making the working environment worse during production.

[0100] (Effect of claim 24) The twenty-fourth invention according to claim 24 uses an emulsion or suspension system to manufacture a master batch of a blowing agent, so it is possible to use less solvent than when using varnish, which has the effect of not worsening the working environment. Emulsion and suspension systems have less risk of ignition and fire compared to solvent systems, so work can be done safely.

[0101] (Explanation of claim 24) In the 24th invention related to claim 24, the resin to be foam-molded is PS, HIPS, or modified PPO(E), and PS or HIPS is dissolved in a solvent in advance, and an emulsifier is used as necessary to make an emulsion or suspension system. This solution is used to support the foaming agent powder on the surface of pellets of PS, HIPS, and modified PPO(E), allowing less solvent to be used.

[0102] (Configuration of claim 25) The twenty-fifth invention according to claim 25 uses a varnish of an acrylic resin or a styrene-modified acrylic resin that is compatible (soluble) with a styrene-based resin and is used in the manufacture of paint, to support the foaming agent powder.

[0103] (Function of claim 25) The acrylic resin and styrene-modified acrylic resin in the varnish according to the 25th invention relating to claim 25 exhibit compatibility (solubility) with styrene-based resins such as AS, ABS, PS, HIPS and modified PPO(E).

[0104] (Effect of claim 25) In the 25th invention according to claim 25, the acrylic resin and styrene-modified acrylic resin, which are the main components of the varnish used, are compatible with AS, ABS, PS, HIPS, and modified PPO(E). Only one type of varnish is required to manufacture the master patch of the blowing agent, and commercially available paint materials can be used, making it economical.

[0105] (Explanation of claim 25) The varnish used in the master batch production of the blowing agent of the 25th invention according to claim 25 can be a raw material for paint production that is commercially available for use in paint for plastics. It can be easily supported by using a rocking mixer or the like as an example of the means. The varnish used should be simple, consisting only of acrylic resin or styrene-modified acrylic resin. If the varnish contains CAB (cellulose acetate butyrate) or soluble nitrocellulose, CAB is acceptable, but varnishes containing soluble nitrocellulose cannot be used. soluble nitrocellulose is not recommended as it will cause discoloration during foam molding. CAB will not cause discoloration.

[0106] (Configuration of claim 26) The 26th invention related to claim 26 relates to a master batch of a blowing agent produced by using an emulsion-type or suspension-type varnish of an acrylic resin or a styrene-modified acrylic resin used in the production of a master batch of a blowing agent.

[0107] (Function of claim 26) The 26th invention according to claim 26 uses emulsion and suspension systems, which improves the working environment.

[0108] (Effect of claim 26) The 26th invention relating to claim 26 uses acrylic resin and styrene-modified acrylic resin varnishes in the form of emulsion and suspension systems, which results in less odor during the production of the foaming agent master batch, thereby preventing the working environment from becoming poor. Compared to solvent-based products, emulsion and suspension systems have less risk of ignition or fire, so they can be worked with safely.

[0109] (Explanation of claim 9) (Explanation of claim 26) The 26th invention according to claim 26 uses emulsion- or suspension-type varnish of acrylic resin or styrene-modified acrylic resin in the manufacture of a master batch of a blowing agent. Acrylic resin and styrene-modified acrylic resin are compatible with styrene-based resins such as PS, HIPS, modified PPO(E), AS, and ABS, so there is no need to prepare a large amount of varnish during work. Emulsifiers are used when making emulsion or suspension systems, but rather than looking for paint or coating performance, the purpose must be met if the material adheres to the surface of pellets etc., is easy to handle and mix before foam molding, and so it is perfectly possible to do this without emulsifiers.

[0110] (Configuration of claim 27) The manufacturing method of master batch for PP blowing agent is shown. PP has high chemical resistance, and there are few solvents that can dissolve PP by itself. To make PP soluble in a solvent, PP is modified with acid. The 27th invention relating to claim 27 uses an acid-modified PP varnish to manufacture a master batch of a PP blowing agent, and similarly to the manufacture of a master batch of a blowing agent for styrene-based resins such as HIPS and ABS, the acid-modified PP varnish is used to support a blowing agent powder on the surface of PP pellets to be foamed.

[0111] (Function of claim 27) In the 27th invention according to claim 27, the PP to be foamed and the acid-modified PP are compatible (soluble). Even if an acid-modified PP varnish is used to manufacture a master batch of a foaming agent and foamed, the acid-modified PP is compatible (soluble) in the molded resin and finely dispersed in the PP, forming an island structure, and has almost no effect on the physical properties of the PP resin.

[0112] (Effect of claim 27) The 27th invention according to claim 27 uses an acid-modified PP that is compatible (miscible) with the PP to be foamed. Therefore, they melt together at the heating and melting stage during molding, mix in the resin, and finely disperse to form a sea-island structure, and have almost no effect on the physical properties of the PP, making it possible to foam mold the PP.

[0113] (Explanation of claim 27) The 27th invention according to claim 27 relates to the manufacture of a master batch of a blowing agent for PP. Commercially available master batches of blowing agents for PP use a PE carrier resin, so even if a foam molding product with a beautiful appearance without swirl marks is produced using GCP, silver spots caused by PE occur near the gate (see Figure 1). However, since the melting temperature of PP is about 20°C higher than that of PE, even if you melt the PP and add powdered foaming agents such as bicarbonate, ADCA, or HDCA to it and try to knead it, it will thermally decompose during the melt-kneading stage, and even if you pelletize it, the foaming agent inside will already have lost its function as a foaming agent. By using an acid-modified PP that is compatible with PP, such as maleic acid-modified PP varnish (which is often used as a PP adhesive and as a primer when painting PP molded products), the blowing agent powder can be easily supported on the PP pellets to be foamed, just as in the case of HIPS and ABS, so a master batch of the blowing agent for PP can be easily produced. Furthermore, since the resin is not heated and melted, there is no thermal degradation due to the thermal history of the PP.

[0114] (Configuration of claim 28) In claim 27, a varnish of acid-modified PP (a solvent-based product, obtained by dissolving acid-modified PP in a solvent) is used to manufacture a master batch of a blowing agent for PP, while in the 28th invention related to claim 28, a varnish (a product obtained by dissolving acid-modified PP in a solvent) is used as an emulsion or suspension system.

[0115] (Function of claim 28) The 28th invention according to claim 28 is used as an emulsion or suspension system that uses a small amount of solvent. Even acid-modified emulsion and suspension types have the function of an adhesive for PP, so they are effective enough to support the foaming agent powder on the surface of the PP pellets.

[0116] (Effect of claim 28) The twenty-eighth invention according to claim 28 uses a small amount of solvent in an emulsion or suspension system, so it does not deteriorate the working environment and has little risk of ignition or fire, making it possible to safely manufacture a master batch of a PP blowing agent. .

[0117] (Explanation of claim 28) The 28th invention according to claim 28 relates to a method for producing a master batch of a blowing agent for PP, in which an emulsion or suspension-type mono of acid-modified PP is supported on the surface of the PP. Since acid-modified PP is compatible with the PP to be foamed, it is possible to manufacture a master batch of the blowing agent for PP. As with claim 27, even if it penetrates and mixes into PP, it has almost no effect on the physical properties of PP. Acid-modified PP has high thermal stability, and it has been confirmed in experiments of the present invention (foaming molding using PP pellets and a blowing agent supported by acid-modified PP) that there is no problem even if it is mixed into PP and foamed.

[0118] (Configuration of claim 29) The 29th invention according to claim 29 relates to a master batch of a foaming agent used in foam molding, the components of the foaming agent consisting only of foaming agent powder and a resin constituting a varnish that is compatible (miscible) with the resin to be foam molded.

[0119] (Function of claim 29) The 29th invention according to claim 29 does not support foaming agent powder on the surface of pellets, but rather a mixture of varnish and foaming agent powder (liquid in nature), which is, for example, first placed in a rocking mixer with a small amount of foaming agent powder, and heated while adding small amounts at a time, causes the mixture of the foaming agent and the resin component in the varnish to grow around the foaming agent powder added initially as a nucleus, and granulation is achieved.

[0120] (Effect of claim 29) In the twenty-ninth invention according to claim 29, a master batch of a blowing agent can be produced by granulation, so the concentration of the blowing agent (the amount of the blowing agent contained in the granules) is high. If a styrene-modified acrylic resin is used for the acrylic resin and varnish, a master batch of a blowing agent that can be used for any styrene resin such as HIPS or ABS can be produced.

[0121] (Explanation of claim 29) Powdered foaming agents are difficult to handle, but by granulating the powdered foaming agent with a small amount of varnish, it becomes easier to handle. Moreover, since it does not require the conventional melt-kneading process, it is easy to manufacture foams with high concentrations of foaming agents.

[0122] (Configuration of claim 30) In the thirtieth invention according to claim 30, a powder of a foaming agent and a powder of a resin to be foam-molded or a powder of a component of the resin are granulated by using a varnish.

[0123] (Function of claim 30) The 30th invention according to claim 30 granulates a powder of a blowing agent, a varnish, a powder of a resin to be foamed, or / and a powder of a resin compatible (soluble) with the resin to be foamed. For example, ABS is a blend polymer of AS and butadiene grafted with A (acrylonitrile) and S (styrene), and if AS powder is mixed with the blowing agent powder and granulated using varnish, a master batch of the blowing agent can be easily manufactured. AS and PS are soluble in solvents, so if AS powder or PS powder and the blowing agent powder are put into a rocking mixer, mixed, and sprayed with, for example, MEK, granulation can be performed without using varnish. For example, if you put pellets of AS and ABS, add foaming agent powder, and then spray MEK, the surface of the AS and ABS will dissolve with the MEK, so you can produce a master batch of the foaming agent.

[0124] (Effect of claim 30) The thirtieth invention according to claim 30 also makes it possible to produce a master batch of a blowing agent containing a higher concentration of the blowing agent than the conventional melt-kneading method.

[0125] (Explanation of claim 30) The 30th invention according to claim 30 is a master batch of a foaming agent produced by mixing a powder of a foaming agent with a powder of a resin, stirring the mixture with a rocking mixer or the like, and spraying a solvent or varnish onto the mixture to granulate the mixture.

[0126] (Configuration of claim 31) The 31st invention relating to claim 31 involves carrying powdered foaming agent, powdered foaming assistant, powdered foam nucleating agent, powdered pigment, dye, etc., separately on pellets of resin to be foamed, and mixing the carried pellets with the pellets of resin to be foamed for use.

[0127] (Function of claim 31) The 31st invention relating to claim 31 uses pellets carrying each of the substances (both the substances carried on pellets and the substances granulated) mixed in the optimal addition amounts, making it possible to optimize the amount of each substance added.

[0128] (Effect of claim 31) The 31st invention relating to claim 31 uses pellets carrying powders of materials that exhibit each of the functions in an optimized mixture, so that there is no need to add excess amounts, and the mixture amounts can be easily changed, resulting in economical effects and stable and improved quality.

[0129] (Explanation of claim 31) The thirty-first invention according to claim 31 relates to a method for producing a master batch using the varnish, solvent, etc. described in the present invention, adding an optimal amount of additive, and performing foam molding. Since pellets of the resin to be foamed are not used, the foaming agent master batch made from acrylic resin and styrene-modified acrylic resin can be reduced in number because the acrylic resin and styrene-modified acrylic resin are compatible with HIPS, ABS, etc. In the same way, it is also possible to prepare masterbatches of high concentration blowing agents for PP using acid-modified PP varnish.

[0130] (Configuration of claim 32) The 32nd invention according to claim 32 is a foam-molded product to which a coating is applied for the purpose of cosmetic properties, and the foaming agent used does not reduce the adhesion and adhesion of the coating film. Problem-free organic foaming agents such as ADCA and HDCA, water, alcohol, ether, etc. that do not leave foaming residues that affect the adhesion and adhesion of the coating film are used.

[0131] (Function of claim 32) In the 32nd invention related to claim 32, the foaming agent used is selected from those that do not leave foaming residues and those whose foaming residues do not affect the adhesion and adhesion of the coating film, so that problems with the adhesion and adhesion of the coating film do not occur.

[0132] (Effect of claim 32) The 32nd invention relating to claim 32 uses a foaming agent that does not affect the adhesion and adhesion of the coating film, and therefore does not require pretreatment (cutting) aimed at removing troublesome foaming residue. Instead, the coating process can be simplified by simply removing any dirt adhering to the surface with an air blower or the like and removing any oils and greases with an alcohol wipe or the like.

[0133] (Explanation of claim 32) The foaming agent used in foam molding is thermally decomposed in the heating cylinder to generate foaming gas, which is pressurized and dissolved in the molten resin in the heating cylinder and finely dispersed to impart foamability to the molten resin. However, the decomposition residue of the foaming agent penetrates into the resin to which foamability has been imparted. Foaming residue is found on the surface of the foam-molded product into which the foaming residue has penetrated. If the foaming residue is not removed before painting and a salt spray test, salt water immersion test, moisture resistance test, water resistance test, etc. are conducted, the coating film will swell and peel due to the foaming residue, making it unusable. Experiments have confirmed that residues of ADCA and HDCA in azo-based foaming agents do not affect the adhesion or cohesion of paint films, so azo-based foaming agents such as ADCA and HDCA are suitable for producing foam-molded products that undergo a painting process.

[0134] The boiling points of water and ethanol are 100℃ and 80℃, respectively. When these are weighed out and added to the molten resin in the heating barrel during the measuring (plasticization) process, they are vaporized by the heat of the heating barrel and the temperature of the molten resin, dissolving and dispersing in the molten resin and imparting foaming properties to the molten resin. However, alcohol and other liquids all vaporize, leaving no residue behind. If these liquids are used as foaming agents, problems with the adhesion and adhesion of the coating caused by foaming agent residues are solved.

[0135] (Configuration of claim 33) In the 33rd invention according to claim 33, when a hydrogen carbonate (e.g., baking soda) is used as a foaming agent, the carbonate (sodium carbonate in the case of baking soda) in the foaming residue is undecomposed hydrogen carbonate, which becomes the foaming residue. If painting is applied in this state, the foaming residue present on the surface will cause swelling and peeling of the coating film, so before that happens, these foaming residues are removed using an acidic substance.

[0136] (Function of claim 32) In the thirty-second invention according to claim 32, since carbonates and hydrogen carbonates are alkaline substances, they are neutralized when they come into contact with an acidic substance and easily dissolve. Foam molded products that use these hydrogen carbonates as foaming agents can obtain sufficient adhesion and bonding of paint films by performing acid washing, etc.

[0137] (Effect of claim 32) The 32nd invention according to claim 32 uses hydrogen carbonate as a foaming agent at low cost, generates foaming gases of carbon dioxide gas and water vapor, and produces fine foam cells, resulting in a stable foamed molded product. By acid washing the molded product, it is possible to obtain sufficient adhesion and adhesion of the coating film.

[0138] (Explanation of claim 32) Hydrogen carbonate is widely used as a foaming agent, but when foamed molded products with foam residue or undecomposed hydrogen carbonate on the surface are painted, the adhesion and adhesion of the paint film decreases, and when evaluation tests for the paint film are performed (such as JIS K5600-7-1), swelling and peeling occur, making it unsuitable for use. Carbonates and hydrogen carbonates can be easily removed (dissolved) by immersing in a weak acidic solution and wiping with a cloth soaked in a weak acid. After acid cleaning, rinsing with water as necessary, drying, and painting can provide sufficient adhesion and adhesion of the paint film. The acid used for acid cleaning can have a pH of about 6. If the temperature of the acid solution used for cleaning is raised to 40°C or higher, it can simultaneously remove grease and oil. It is more effective if an ultrasonic oscillator (plate) is placed in the cleaning solution. Valving can also be used.

[0139] [Brief description of the drawings]

[0140] [Figure 1] Silver spots caused by the base resin of the foaming agent master batch occurred near the gate, and swirl marks at the end of the flow could not be controlled (suppressed) due to insufficient GCP pressure (material used was PP). [Diagram 2] Although the GCP was able to control (suppress) the swirl marks, silver was present near the gate due to the base resin of the foaming agent master batch (the material used was PP used for automotive interiors) (the material used was TSOP). [Diagram 3] This is a diagram (photo) showing that swirl marks occurred on the entire surface without GCP implementation (material used was transparent ABS). [Figure 4] This is a diagram (photo) showing that after GCP was performed, the foam cells were suppressed, and no swirl marks were observed on the surface, making it smooth (the material used was transparent ABS). [Diagram 5] A cross-sectional view (photo) of a foam molded product showing that by using GCP, it is possible to confine the foam cells inside (the surface is a clean skin layer without swirl marks, and the inside is a foam layer), with a foam layer inside (reference number 110) and a clean skin layer on the outside (reference number 111). [Figure 6] Carbonated water diagram (photo). [Figure 7] A diagram (photo) showing the reason for foaming. [Figure 8] Diagram (photo) showing the principle of GCP. [Figure 9] GCP equipment. [Figure 10] Schematic diagram showing the structure of a foam molding mold in which the ejector mechanism is enclosed and sealed in a box. [Figure 11] Schematic diagram showing the structure of a foam molding die in which the ejector pin is sealed with a load-type O-ring or the like. [Figure 12] Schematic diagram showing the dovetail groove that secures the O-ring. [Figure 13] This is a schematic diagram showing the foam molding mold structure, showing the compressed air spaces L1 to L3 of the mold in Figure 10. In Figure 13, L1 indicates the space of the ejector box, L2 indicates the space of the molding space, and L3 indicates the space provided at the bottom of the fixed side insert. [Figure 14]FIG. 11 is a schematic diagram showing the foam molding mold structure, showing the compressed air spaces L1 to L3 of the mold. L1 in FIG. 14 is the space provided at the bottom of the movable insert, which corresponds to the L2 ejector box space in FIG. 13. L2 is the molding space, and L3 is the space provided at the bottom of the fixed insert. [Figure 15] GCP equipment. [Figure 16] GCP device (with subtank 55). [Figure 17] Schematic diagram explaining the state before core-back (when foamable resin is filled). [Figure 18] Schematic diagram illustrating the core-back state (expanded). [Figure 19] Schematic diagram explaining the state before mold back (when foamable resin is filled). [Figure 20] Schematic diagram illustrating the state after mold back (expanded). [Figure 21] CAD drawings of the molded products used in the examples. [Figure 22] CAD drawings of the molded products used in the examples. [Figure 23] Schematic diagram showing a device for heating a magnetic fluid by electromagnetic induction. [Figure 24] Schematic diagram explaining the load type O-ring (assembly diagram incorporating a spring with a load function). [Diagram 25] Cross-section of a schematic diagram explaining a load-type O-ring (the opening of the load function spring faces upwards). [Figure 26] Cross-section of a schematic diagram explaining a load-type O-ring (the opening of the load function spring faces downward). [Figure 27] Schematic diagram showing a cross section of a U (V) shaped O-ring. [Figure 28] Schematic diagram showing a U(V) shaped O-ring. [Figure 29] Diagram (photo) of a commercially available coil spring with the function of replacing number 85. [Diagram 30] Diagram (photo) of a commercially available O-ring. [Diagram 31] FIG. 13 is a schematic diagram showing a means for applying gas pressure from the fixed side. [Diagram 32]Schematic diagram showing the inner core of a gas pin used for gas pressurization. [Diagram 33] A schematic diagram showing the outer cylinder of a gas pin used for gas pressurization. [Diagram 34] A schematic diagram of an inner core inserted into the outer cylinder of a gas pin used for gas pressurization. [Diagram 35] Schematic diagram showing gas pressure pins installed on the surface of the molded product. [Diagram 36] This is related to Figure 48, which is a schematic diagram of a one-sided loaded O-ring that seals the ejector pin and a diagram showing the shapes (housing dimensions) of the pilot holes etc. related to the diameters of each ejector pin. [Figure 37] A diagram showing a means for sealing only one ejector turbine. [Figure 38] A diagram showing the connection between the mold and the GCP device. [Figure 39] A diagram showing the gas vents that let in and out the compressed air from the GCP at the mold parting. [Diagram 40] A diagram showing the gas vents that let in and out the compressed air from the GCP at the mold parting. [Diagram 41] The diagram shows the shapes of L1 and L3 (compressed air passages) at the bottom of the insert. [Diagram 42] A diagram (table) showing the combination of resin, foaming agent master batch and foam nucleating agent master batch. [Diagram 43] A diagram (table) showing the observation results of the exterior and interior when GCP is not used. [Diagram 44] A diagram (table) showing the observation results of the exterior and interior when GCP is used. [Diagram 45] A table showing the evaluation results of the adhesion of the coating. [Figure 46] A table showing the evaluation results of the adhesion of the coating. [Figure 47] A table showing the evaluation results of the adhesion of the coating. [Figure 48] A diagram (table) showing detailed dimensions for installing a one-sided load type O-ring. [Figure 49] FIG. 13 is a diagram showing a means for further evacuating the inside of the mold after exhausting the compressed air. [Figure 50] A schematic cross-sectional view showing the structure of a mold, illustrating the means of pressure ingress and egress from PL. [Figure 51] A schematic diagram showing the structure of a mold, illustrating the means of ingress and egress of pressure onto the product surface of the mold. [Figure 52] Schematic diagram showing a cross section of Figure 51. [Diagram 53] This is a schematic diagram showing how the metal of the fixed die and the metal of the fixed die are not separated by the core-back, and how the working die is inserted into the molded product, and the foamable resin is filled into the molding space, after which the working die is retracted. [Figure 54] Schematic diagram showing that reference number 61 (movable mold) in Figure 53 has been retracted. [Figure 55] Schematic diagram showing a cross section of a V-ring. [Figure 56] Schematic diagram showing a cross section of a U-ring. [Figure 57] Schematic diagram showing a cross section of a PL sealing means with the V-ring opening facing the PL direction and also showing the placement of a regular circular O-ring. [Figure 58] Schematic diagram showing a cross section of a PL sealing means with the U-ring opening facing the PL direction and also showing the placement of a normal circular O-ring. [Figure 59] The V-ring opening faces the PL direction, and has the function of sealing the pressurized gas in the molding space, while another V-ring faces the opposite direction to the PL, and serves to seal so that outside air does not get in from the mating surfaces of the PL when the inside of the PL is evacuated. A schematic diagram showing the cross section of the sealing means of the PL, which also shows the placement of a normal circular O-ring. [Figure 60] The opening of the U-ring faces the PL direction, and has the function of sealing the pressurized gas in the molding space, while another U-ring faces the opposite direction to the PL, and serves to seal so that outside air does not get in from the mating surfaces of the PL when the inside of the PL is evacuated. A schematic diagram showing the cross section of the sealing means of the PL, which also shows the placement of a normal circular O-ring. [Figure 61] A schematic diagram of the V-ring of Figure 55 when it is provided on the left and right and integrated. [Figure 62]FIG. 57 is a schematic diagram of the U-ring of FIG. 56 when it is provided on the left and right sides and integrated. [Figure 63] Schematic diagram of a vacuum device (vacuum device, vacuum drawing device). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0141] (Definition of terms) First, the terms used in the present invention will be defined.

[0142] (less than, less than or equal to, greater than or equal to) "Less than" does not include the numerical value that follows. "Less than or equal to" includes the numerical value that follows. "Greater than or equal to" includes the numerical value that follows. For example, a pH of less than 7 does not include 7, and the solution is acidic rather than neutral (PH=7). A pH of 7 or less includes 7, and therefore indicates both neutral and acidic.

[0143] (Applicable products, etc.) The products to which the present invention can be applied are resin molded products made by injection molding, casting, block molding, etc., regardless of the material, shape, or use. Styrene-based resins, or polymer alloys and polymer blends containing styrene-based resins, are mainly used in office equipment, home appliances, and gaming machines. Olefin-based resins, or polymer alloys or polymer blends containing olefin-based resins are mainly used in vehicles. Polymer alloys or polymer blends containing thermoplastic resins such as styrene-based resins, olefin-based resins, vinyl-based resins represented by vinyl chloride, ester-based resins, and amide-based resins are mainly used in houses, furniture, miscellaneous goods, etc. The present invention also targets molded products using recycled materials that are modified and modified to create new molding materials using market-recovered thermoplastic resins as starting materials. Compared to solid molding, foam molding does not use a dwell pressure, so dimensional stability (= repeatability of the dimensions of the molded product) is high, making it suitable for using recycled (regenerated) thermoplastic resins. IC trays made of modified PPO(E) with acetylene black or other additives can be made lightweight by foam molding, which reduces the energy required for transportation during burning, inspection, etc.

[0144] Resins that can be used in the present invention are listed in The Chemical Daily's Plastic Molding Material Business Handbook - Property Database (1999 edition, 2012 edition). In the present invention, any type of thermoplastic resin may be used as long as it is suitable for molding. Examples of thermoplastic resins include polystyrene resins obtained by polymerizing styrene monomers, such as polystyrene (PS) and high impact polystyrene (HIPS), styrene resins that are copolymers of nitrile monomers and styrene monomers, such as acrylonitrile-styrene copolymer (AS), resins made of nitrile monomers, styrene monomers and butadiene rubber, such as acrylonitrile-butadiene-styrene copolymer (ABS), styrene resins such as AES made of butadiene rubber as olefin rubber, and ASA (AAS) made of acrylic rubber, polyethylene (PE), polypropylene, etc. It is also possible to implement this with polyolefin resins such as polypropylene (PP), polyphenylene oxide (PPO), polyphenylene ether (PPE), styrene-modified polyphenylene oxide (m-PPO), styrene-modified polyphenylene ether (m-PPE), polycarbonate (PC), polyamide (PA), polysulfone (PSF), polyetherimide (PEI), polymethyl methacrylate (PMMA), and other engineering plastics, polyester resins such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), and vinyl resins such as polyvinyl chloride (PVC).

[0145] Two or more kinds of thermoplastic resins and / or thermoplastic elastomers may be mixed to form a polymer blend or polymer alloy. The polymer blend or polymer alloy is produced, for example, by screw kneading in an extruder.

[0146] The resin of the present invention may be used with compounding chemicals listed in the Handbook of Rubber and Plastic Compounding Chemicals compiled by Rubber Digest Co., Ltd., March 1989 (latest edition), 1993, and December 2003 (revised second edition), so long as the functions are not impaired. When compounding the resin, other resins and additives may be used, such as pigments, dyes, reinforcing agents (glass fiber, carbon fiber, etc.), fillers (carbon black, silica, titanium oxide, talc, etc.), heat resistance agents, antiaging agents, antioxidants, antioxidants for oxidation and deterioration, antiozonants, weather (light) resistance agents (ultraviolet absorbers, light stabilizers), plasticizers, foaming assistants, foam nucleating materials, lubricants, slipping agents, internal mold release agents, mold release agents, anti-fog agents, crystal nucleating agents, flame retardants, flame retardant assistants, flow improvers, antistatic agents, compatibilizers, and the like.

[0147] In the present invention, "resin" refers to all of thermoplastic resins (TPR), thermosetting resins (TSR), TSE (thermosetting elastomer), TPE (thermoplastic elastomer), and rubber, and thermoplastic resins and / or TPEs that exhibit thermoplasticity are referred to as "thermoplastic resins." Thermosetting resins, rubber, and TSEs that exhibit thermosetting properties are referred to as "thermosetting resins."

[0148] The main technology of this invention, GCP, will be explained. The action and effect of GCP {foam cells are trapped inside, and a beautiful skin layer (non-foamed layer, layer in which foaming on the surface is suppressed by the action of GCP) is formed on the outside (surface).} is shown in Figures 2 and 6 when PP is used, and in Figure 4 when transparent ABS is used so that the foam cells inside can be confirmed. Figure 5 is a cross section of a foam molded product that has been subjected to GCP using PP. The reference numbers in Figures 1 to 5 indicate that reference number 1 is a side gate, with two gates, one on each side of the opening. Reference number 2 indicates that silver (PE surface lifting) occurs due to the foaming agent master batch (abbreviation: MB) in GCP molding using PP as described above. Reference number 3 indicates that swirl marks cannot be suppressed if the GCP pressure (pressure applied inside the mold) is low and the exhaust timing is too early. Reference number 4 indicates that swirl marks occurred all over the surface when foam molding was performed without using a GCP. ADCA was used as the foaming agent in carrying out the procedures shown in Figures 1 to 5. No foam nucleating agent or foaming assistant was used. The same results were obtained with sodium bicarbonate, and similar results were obtained with sodium bicarbonate. When ACDA and sodium bicarbonate are used in combination, the foam cells become finer compared to when ADCA is used alone. Increasing the GCP pressure also has the effect of suppressing and trapping the foaming residue inside the molded product. As a result, it is speculated that using high GCP pressure may make it possible to suppress unfoamed foaming agent and foaming residue, even in foam molded products that use sodium bicarbonate, and to paint them.

[0149] (Compatibility and compatibility) "Compatibility" refers to the property of two resins mixing at the molecular level (for example, sugar dissolves in water), and "compatibility" is defined in the present invention as the property of one resin penetrating into another resin, forming an island-sea structure. Compatibility and compatibility are collectively referred to as compatibility (solubility).

[0150] {Forming equipment (unit, device, device)} The "molding device" used in this invention refers to the above-mentioned GCP device, blow molding, pressure molding device (device for separating nitrogen gas in the air, device for compressing nitrogen gas, device for injecting and ejecting compressed nitrogen gas to obtain blow molding and pressure molded products), GCP, mold back, core back, recess, breathing, suck back of the screw after injection (to reduce the pressure of the resin filled in the mold), etc., an injection molding machine in which a program for controlling these devices is written (incorporated or installed) into the sequencer of the injection molding machine so that operations such as blow molding and pressure molding can be performed, a sealed molding mold shown in Figures 10 and 11, etc., a GCP device such as in Figures 9, 15, 16, and 49 {the injection molding machine of this invention has installed therein a program for commanding the opening and closing of the compressed air valve, exhaust valve, and valve (reference number 141) for evacuation in Figures 9, 10, 11, and 49.}, the die shown in Figure 50, the die heating device in Figure 23, a shut-off nozzle operated by a hydraulic, pneumatic, mechanical or spring mechanism, a device that carries the foaming agent on the resin pellets, and a device that mixes and granulates the foaming agent powder ("powder" refers to a finely divided solid, and "powder" refers to a state in which a large number of powder particles are gathered together) with the resin powder.

[0151] (molding material) The "molding material" used in the present invention refers to a thermoplastic resin and other additives used in the production thereof, such as a reinforcing agent typified by glass fiber, a foaming agent, a foaming assistant, and a foam nucleating agent. Thermosetting resins are also possible.

[0152] (merchandise) Foaming agent master batches carrying foaming agents, foaming molded products using foaming agents granulated from foaming agent powder and resin powder, and foaming molded products with smooth surfaces using the GCP device shown in this invention are all possible for injection molded products, block molded products, and cast molded products whose main component is thermoplastic. These foaming molded products are widely used in automobile parts, home appliances, office automation equipment, housing equipment, miscellaneous goods, game machines, etc.

[0153] "Molding space" refers to the space filled with foamable resin and / or non-foamable resin in injection molding, block molding, or cast molding. "Inside the cavity" refers to the inside, space, or volume (vol) of the molding space. "Mold cavity" is synonymous with "molding space." It is sometimes simply called "cavity."

[0154] "Injection" refers to the process of filling, injecting, or otherwise inserting foamable and / or non-foamable resin into a molding space.

[0155] "Filling" refers to filling the molding space with foamed resin and / or non-foamed resin in molding processing. Filling an amount less than the volume of the molding space is called short shot or short mold. Filling an equivalent amount is called full shot or full pack. Filling an amount greater than the volume of the molding space is called overshot or overpack. If pressure is applied to the resin from the molding machine heater barrel after full shot to reduce sink marks or improve transferability, it is clearly stated that pressure was used. In the case of block molding, the distinction between non-pressurized and pressurized is clearly stated, such as non-pressurized after filling and pressurized after filling.

[0156] "Resin in the heating barrel" refers to thermoplastic resin in a solid (solid) state such as pellets, bulk, or powder before being heated and melted, in the middle of being plasticized, or in a molten state after plasticization is complete, inside the heating barrel of a molding machine (injection molding machine, extrusion molding machine, cast molding machine, etc.).

[0157] {Gas Counter Pressure (GCP)} "GCP" refers to a process in which gas above atmospheric pressure is applied to the inside of a seal mold (molding space, etc.) shown in Figures 10 and 11 in advance to pressurize the mold, and foamable resin that has been given foamability using a gas, liquid, or solid foaming agent (can be used alone or in combination) is injected and filled under pressure, and the gas put into the mold is exhausted during the filling process (the timing of exhaust varies depending on the type of resin, the type of foaming agent, the amount of foaming agent added, the type of foaming gas, the GCP pressure, etc., but from the inventor's experience, even if exhaust is performed at a stage where the foamable resin is filled 90% or more in the molding space, it takes time for the gas to be completely exhausted, and there is a slight delay in the time until the foaming gas in the resin comes to the surface and becomes a swirl mark, so a beautiful molded product without swirl marks on the surface can be obtained.) This means a means and process for obtaining a molded product (foam structure) with a smooth and beautiful skin layer (non-foamed layer) without swirl marks (foam stripes) on the surface and a foamed layer inside. GCP can also mean the act or process of pressurizing the inside of a sealing mold with gas at atmospheric pressure or higher. GCP can also be called "compressed air," and compressed air can mean pressurizing the inside of a mold to atmospheric pressure or higher, or the gas put into the mold.

[0158] As for the means of pressurizing the GCP mold, Figures 10 and 11 show pressurization from the parting into the molding space, but other means are also possible, for example, the ejector pin may have a double structure and pressurize from the gap between the inner core and the outer cylinder. If the ejector pin is made of Gastos (product name) and the tip is made of sintered metal so that compressed gas can pass through, the molding space can be pressurized. In this case, the compressed air is applied to the gap in the ejector plate by making the ejector plate resistant to the compressed air pressure. In this case, the mold structure should preferably have the ejector pin in Figure 11 sealed with a load-type O-ring as shown in Figures 24 to 30. It is also possible to provide a double-structured insert (nested insert) of about φ50 mm in the part that is not the costume surface and apply pressure through the gap. In this way, the compressed air in the molding space is not limited to the gap in the parting, but the exhaust transfers the compressed air in the molding space from the parting to another place, for example, reference number 55 in Figure 6, by the force of filling (= being filled) with molten resin. For example, in JP2010-184401A, it is possible to apply pressure to the inside of the mold, but it is not possible to transfer the compressed gas, which is an obstacle to filling the resin into the mold, to another location. This method can cause short molds, discoloration, and burning.

[0159] "Supporting" refers to the process of attaching other substances, such as the foaming agent powder, foaming assistant powder, foam nucleating agent powder, and / or pigment powder, and other additives, to the surface of resin pellets using, for example, a varnish for paint or a doped cement in which the resin to be molded is dissolved in a solvent, as a binder. For AS and ABS (including AAS, ASA, AES, and ACS), doped cements and varnishes in which AS, ABS, acrylic resin, and styrene-modified acrylic resin are dissolved in a solvent are used, and for the resin to be molded is PS, HIPS, or modified PPO(E), doped cements and varnishes in which PS, HIPS, acrylic resin, and styrene-modified acrylic resin are dissolved in a solvent are used. For PP, acid-modified or halogenated PP, or maleic acid-modified PP (e.g., modified with maleic anhydride) are dissolved in a solvent or emulsified with water and used as a binder.

[0160] (binder) "Binder" refers to a substance that acts as an adhesive when foaming agents, foam nucleating agents (powdered), decomposition accelerators, etc. are mixed together and applied to the surface of pellets to be foamed, and acts as an adhesive when the powder of the foaming agents, etc., and the powder of the resin to be foamed are mixed together and solidified to form a granule. Examples of binders include dope cements made by dissolving AS, ABS, PS, and HIPS, which are compatible (soluble) with ABS, HIPS, and modified PPO(E), in a solvent such as MEK, styrene-modified acrylic resin varnishes, and emulsions and suspensions of styrene-modified acrylic resins that are commercially available for paints. For PP, varnishes made by dissolving maleic acid-modified PP in a solvent, and emulsions and suspensions of maleic acid-modified PP are examples.

[0161] {Suspension is created using foaming agent powder.} Suspensions are also used for materials that are insoluble in the varnish, such as organic foaming agents such as ADCA and HDCA powder mixed with inorganic foaming agents such as sodium bicarbonate in a solvent-based varnish. Materials in which ADCA and HDCA are dispersed in a water-based emulsion may also be used. Varnishes in which sodium bicarbonate, which is soluble in water, is dissolved in an emulsion may also be used. These varnishes can be sprayed on the pellets while heating them, and the varnish contains the foaming agent (dispersed or dissolved), so it can be supported on the pellets in the same way. Granulation is also possible without using pellets, by adding a small amount of foaming agent powder beforehand and spraying while heating. It is also possible to manufacture a master batch for foaming by putting the pellets in a rocking mixer and spraying the suspension. It is also possible to put the pellets and suspension in and heat them while stirring.

[0162] "Acid modification" means that PP is insoluble in most solvents, and when it is supported on the surface of the PP pellets of the present invention, a varnish of a resin compatible with the PP to be molded is used. When the resin to be molded is PP, a PP compatible with the PP is modified so that it can be dissolved and finely dispersed in a solvent or water. In general, PP can be modified using maleic acid, acrylic acid, chlorine (CI), bromine (Br), etc. When halogens such as chlorine and bromine are used, there is a risk of the halogens being decomposed in the heating cylinder during foam molding processing and released, corroding the heating cylinder, screw, mold, etc., and discoloring the PP. Since maleic acid and the like are weak acids, when PP is acid-modified using these acids, even if the acid is released, there is little or no problem of corrosion of the heating cylinder, screw, mold, etc. Whether acid-modified PP can be used as a binder for the support of the present invention can be determined by supporting it on PP pellets at 1 wt% to 5 wt%, or 1 mass% to 5 mass% if expressed using mass instead of weight, and purging the supported PP in an injection molding machine to see if the purged mass shows any discoloration or scorching. The purged mass is observed using a transmission electron microscope (TEM) to check the dispersion form of the PP and maleic acid-modified PP, and the presence or absence of peeling at the interface, and the PP to be actually molded is mixed with the maleic acid-modified PP (taking into account the amount that will get in when used as a foaming agent) to check whether the physical and chemical properties of the PP remain within the range of use. When PP is acid-modified, its melting temperature decreases, so when PP pellets, foaming agent powder, and acid-modified PP powder are mixed together and heated, the acid-modified PP, which has a lower melting temperature, melts and the molten acid-modified PP acts as a binder and can be supported on the surface of the PP pellets. If you put in just the PP pellets first and heat them until the surface is melted, and then add the foaming agent powder, some of it will be supported.

[0163] "Raindrop" is a specific type of cosmetic defect that occurs when GCP is performed. When molten resin is filled into a mold, the gas that has been pressurized inside the molding space to suppress foaming on the surface of the foamable resin gets caught up in the resin during filling and gets into the gap between the molten resin and the mold, resulting in dents on the surface of the molded product.

[0164] (Vacuuming) "Vacuuming" refers to the method of sucking out the compressed air inside the mold using a vacuum pump, or the method of using a vacuum pump in advance to draw the compressed air into a tank (sub-tank) larger than the volume of the sealing mold. In GCP, compressed air is effective in suppressing foaming on the surface, but it gets in the way of filling the resin, which causes raindrops. By performing embossing or increasing the width of the parting gas vent, the compressed air inside the mold can be released smoothly. After exhausting the GCP, a mold back is made 0.1mm or 0.2mm to widen the gas vent. The effect is even greater if a vacuum is performed using the compressed air gas circuit after mold backing.

[0165] In order to avoid raindrop, measures were taken such as lowering the surface temperature of the mold, lowering the viscosity of the resin (i.e. lowering the resin temperature), and slowing down the filling speed to reduce the entrainment of compressed gas, but all of these measures reduced the moldability. However, these measures (either mold backing after exhausting the GCP, or vacuuming at the same time as mold backing with a short delay) were able to solve the raindrop problem.

[0166] Figure 49 shows a method for increasing the foaming ratio and eliminating raindrops by further vacuuming after exhausting the compressed air in the mold. The sealed mold shown in Figures 10 and 11 is closed, the injection valve 46 is opened, and the gas compressed by 43 passes through the circuit 138 (49, 52, etc.) and pressurizes (compresses) the mold with a pressure greater than atmospheric pressure. The pressure is applied to the molding space in advance (called "pressurization" or "compressed air"), and the foamable resin is filled while maintaining this pressure, but the pressurization in the molding space suppresses foaming on the surface, and swirl marks do not occur. Although the type of resin, the type of foaming agent, the amount of foaming agent added, the type of foaming gas, and the timing of exhausting the GCP will vary, from the inventor's experience, the pressure of the compressed air needs to suppress (inhibit) the foaming of the foaming resin filled in the molding space, and it is sufficient if it is above atmospheric pressure, preferably above 0.6 MPa, and the pressure when air is actually used as the compressed air in this embodiment is 0.8 MPa to 1.5 MPa. It is okay to use more than that, but if the compressed air pressure is high, raindrops caused by the compressed air caught by the filling of the resin will easily occur and will increase.

[0167] The pressurized molding space is filled with foamable resin that has been given foaming properties using a gas, liquid, or solid foaming agent (sometimes a single agent, sometimes a combination of gas and solid, or liquid and solid, etc.), and during filling, immediately after filling is completed, or after a short time has passed, the valve 46 is closed and the valve 51 is opened to exhaust the compressed air to the atmosphere. Generally, this is the GCP process shown in the present invention, but the valve 51 is also closed, the valve 141 is opened, and the air is sucked into the tank 142, which has been decompressed in advance using the vacuum pump 144. In this case, if the mold is molded back by about 0.1 mm to 0.3 mm and the PL (parting) is widened, the resulting gas vent will widen, and the compressed air that has entered the gap between the mold and the resin, which causes raindrop, can be forcibly exhausted, so raindrop will not occur. In this case, the O-ring with reference number 33 attached to the parting (reference number 60) must be thick so as not to lose its sealing function (= the parting is molded back to provide a gap in the parting, and the sealing performance is maintained so that air does not enter through the opened parting even when vacuuming). Reference number 136 indicates the flow of compressed air pressurizing the inside of the mold, and reference number 137 indicates the gas pressurizing the inside of the mold. Reference number 139 indicates the flow when compressed air is exhausted into the mold, and reference number 140 indicates the flow of compressed air being evacuated. Reference number 145 is a pressure gauge that checks the degree of pressure reduction in tank 142, reference number 143 indicates the flow of gas in 142 sucked in by the vacuum pump, and reference number 135 indicates the gas compressed by the compressor that is sent into Figures 15 and 16. Reference numeral 146 denotes a check valve provided in the circuit for pressurizing the inside of the mold, reference numeral 147 denotes a check valve provided in the circuit for exhausting the compressed air, and reference numeral 148 denotes a check valve provided in the circuit for drawing a vacuum. The check valves 146, 147, and 148 do not necessarily need to be provided if the opening and closing of the valves 51 and 133 are synchronized.

[0168] (Combination of GCP and blow molding) The foamable resin filled in the molding space is hollowed out using high-pressure gas, and then when it is vented, foaming begins inside. In this case, the ejector pin is made double-layered and high-pressure gas is introduced. The gas is exhausted by opening the exhaust valve installed in the high-pressure gas device. If the ejector plate is lowered and the gas bottle is moved back, the exhaust speed increases, so the high-pressure gas inside is completely exhausted, and the problems of swelling and bursting are solved at once.

[0169] It is also possible to combine the GCP of the present invention with pressure molding (a method in which high-pressure gas is introduced into the gap between the mold and the resin, and the pressure of the high-pressure gas is used to enhance the transferability to the side opposite the pressed side).

[0170] The properties of "foaming agents" can be gas, liquid, or solid, and are broadly classified into physical and chemical foaming agents, each of which can be inorganic or organic. Foaming agents include inorganic chemical foaming agents that are pyrolytic, such as hydrogen carbonates, carbonates, nitrites, hydrogen compounds, hydrogen compounds, carboxylic acids, and carboxylates. In the case of sesquicarbonate (Sesqui=3 / 2), sodium carbonate {(chemical name: sodium sesquicarbonate), chemical formula: Na2CO3·NaHCO3·2H2O}, NaHCO3 pyrolyzes to produce carbon dioxide and water vapor, and contains 2 moles of crystal water (now called "hydrates" rather than the concept of "crystal water"). Of course, these 2 moles of crystal water also vaporize in the heating cylinder, and the water vapor acts as a foaming gas. Microballoons {microballoons} as foaming agents are also included in the foaming agents of the present invention, and can be supported around the resin pellets to be molded using the method (supporting means) of the present invention using a binder, and can be manufactured as a foaming agent master batch.

[0171] Organic pyrolysis types include azo compounds, hydrazine derivatives, semicarbazide compounds, azide compounds, nitroso compounds, and triazole compounds, while reactive types include isocyanate compounds. Examples of these include nitrogen gas, carbon dioxide, etc., either alone or mixed together to form a composite gas, which is put into the resin inside the heating cylinder, such as Musel and Amotech, liquid blowing agents such as water, ethanol, sodium bicarbonate solution, potassium bicarbonate solution, and sodium citrate solution, and commercially available blowing agents include sodium bicarbonate, potassium bicarbonate, ADCA {azo di(di) carboxylic acid amide}, HDCA (hydro dicarboxylic 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 foaming agents and foam molding are described in "Various Polymers and Foam Molding Technology" published by Technical Information Association, Inc. in August 1993. In this invention, in order to clarify the properties of the blowing agent, those whose properties are gaseous at 23°C and 1 atmosphere are classified as "gaseous blowing agents (such as nitrogen gas used in Mu-Cell)", those whose properties are liquid are classified as "liquid blowing agents (such as ethanol, sodium bicarbonate water, etc.)", and those whose properties are solid are classified as "solid blowing agents (such as sodium bicarbonate, ADCA, etc., or blowing agent master batches containing these)". Examples of commercially available blowing agents include Polythrene, Advancel, and Fineblow (all of which are trade names, and the solid properties are pellets).

[0172] When using a liquid foaming agent with thermoplastic resin, the optimal volume relative to the weight of the molded product is measured (weighed) and injected into the thermoplastic resin in the heating barrel. Depending on the temperature of the heating barrel and inside the heating barrel, the temperature of the molten thermoplastic resin in the heating barrel, and / or the temperature of the mold, the foam is vaporized, thermally decomposed, and / or chemically reacted, or decomposed and / or chemically reacted without the need for heat, to generate a gas that is useful (effective) for foaming.

[0173] The generated gas is finely dispersed and / or pressurized and dissolved in the thermoplastic resin in the heating cylinder. The thermoplastic resin in the heating cylinder then becomes a foamable thermoplastic resin. This is then filled into the molding space to produce a molded product having a foamed structure. In other words, "foam molding" refers to the process of obtaining a foamed structure by dispersing and / or dissolving a foaming gas in the resin in the heating cylinder, imparting foamability to the resin, and filling the mold with the resin.

[0174] "Foaming" refers to the process in which liquid or commercially available foaming agents generate gases useful for foam molding, such as water vapor, alcohol vapor (gas), organic solvent vapor, carbon monoxide, carbon dioxide, nitrogen gas, and hydrogen, through physical changes such as vaporization, thermal decomposition, and chemical reactions. "Foaming" refers to the process of finely dispersing and / or pressurizing and dissolving a foaming gas in a molten thermoplastic resin, and then lowering the pressure to form foam cells inside and / or on the surface of the thermoplastic resin. In the case of thermosetting resins, the process refers to the process of heating a foaming agent, which vaporizes, pyrolyzes, and chemically reacts to generate a foaming gas, forming foam cells inside and / or on the surface of the thermosetting resin. Molded products that have foam layers inside and / or outside due to foaming in this way are called foam molded products.

[0175] In other words, "foaming" refers to the state where the foaming gas is suppressed by external pressure, such as GCP, back pressure, injection pressure, etc. (compressed into the resin and finely dispersed in a small volume, or / and pressurized and dissolved), and the volume of the foaming gas in the resin increases, or / and the foaming gas that was pressurized and dissolved becomes gas, when the external pressure is reduced or eliminated. "Foaming" also refers to the process in which a foamable thermoplastic resin is extruded from a heating cylinder and foams, or the process in which a foaming gas is generated by the vaporization, thermal decomposition, or chemical reaction of a liquid or solid foaming agent.

[0176] "Foamable resin" refers to a thermoplastic 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 containing a gaseous foaming agent, a liquid foaming agent, and / or a commercially available foaming agent. In the present invention, the state of the resin is described as accurately as possible, such as "a thermoplastic resin having foamability in a molten state," "a thermoplastic resin containing a foaming agent, or a thermosetting resin containing a foaming agent," and the fact that the resin has foamability, contains a gaseous or liquid foaming agent, and / or a commercially available foaming agent.

[0177] "Foam-molded products" refer to resin molded products that have discontinuous foam cells inside, formed by molding a foamable thermoplastic resin. The size of the foam cells is 1,000 μm (microns, micrometers) or less. In the present invention, foam-molded products are also considered to be products that contain a mixture of hollow parts and foam cells.

[0178] "Combined use" also refers to using or combining with another thing. For example, one molding process is effective, but it can also be combined with another process (GCP and blow molding, GCP and compressed air molding, etc.), which can produce synergistic effects or improve the effects of one or both. Foaming agents are sometimes used in combination with several different types rather than alone. They can also be used in combination with commercially available foaming agents. Gas, liquid, and solid foaming agents can also be used in combination.

[0179] "Foaming assistant" refers to a substance used to lower the decomposition temperature of a foaming agent or to promote the decomposition of the foaming agent. Examples of foaming assistants for organic foaming agents include zinc stearate, barium stearate, metal soap, urea (which has the effect of lowering the decomposition temperature of ADCA), zinc oxide, etc. Inorganic and organic acids (such as citric acid) used to decompose carbonates and hydrogen carbonates can also be considered foaming assistants.

[0180] A "foam nucleating agent" is a substance that is mixed with the resin and foaming agent to be molded in order to form fine foam cells (defined in this invention as foam cells with a diameter of 2000 μm or less). Examples include zinc oxide, silica, talc, titanium oxide, carbonates such as calcium carbonate and barium carbonate, and sulfates such as calcium sulfate and barium sulfate. Resin additives, such as pigments, also act as foam nucleating agents. Alkali metal salts of organic acids, particularly monosodium dihydrogen citrate and monopotassium dihydrogen citrate, act as effective foam nucleating agents.

[0181] "Foaming agent mixing ratio" refers to the ratio of the foaming agent contained in the resin to be molded, with the weight or volume of the foaming agent being taken as 1, and the weight or volume of the resin to be molded. For example, when using 2 wt% or 2 vol (volume, volume)% liquid foaming agent relative to the resin, it is expressed as 2:100 (or 1:50, or 1 / 50), or 2 wt%, 2 vol%, etc.

[0182] (Master batch of foaming agent) Commercially available foaming agents are inorganic substances such as baking soda and potassium bicarbonate, while organic substances such as ADCA and DPT are in powder form. When using these powdered foaming agents, before use, add paraffin oil, olive oil, rapeseed oil, etc. to the resin pellets to be foamed and the powdered foaming agent, mix (using a tumbler, etc.), and spread the foaming agent around the pellets before use. This method of spreading is fine when the amount of resin used is small, but when the amount of resin used is large, spreading becomes a tedious task. A master batch of the blowing agent is produced using a resin that is compatible with the resin to be mixed with the above blowing agent. In the case of master batches, the resin to be foamed is made into pellet form (generally pellets), so the optimal amount (optimal amount of foaming agent master batch to be added) can be easily stabilized using a tumbler or auto-coloring device, resulting in a foamed molded product with a stable expansion ratio. The resin used in the master batch of the foaming agent and foam nucleating agent used in this invention (the resin that is the main component of the master batch (also called carrier resin, base resin, etc.)) must be compatible with the resins it is intended to be mixed with.

[0183] "Compatibility" refers to the property of thermoplastic resins to mix at the molecular level when each resin is heated and melted, for example, AS (a copolymer of acrylonitrile and styrene) is compatible with ABS (a terpolymer of acrylonitrile butadiene and styrene), and PPO (polyphenylene oxide) and PPE (polyphenylene ether) are compatible with PS (polystyrene) and HIPS (high impact polystyrene). Since PPO and PPE have roughly the same molecular structure (oxidized polymer of phenol monomers, for example, methylated or ethylated), in the present invention they are collectively referred to as PPO(E). PPO(E) that is modified or denatured with HIPS and / or PS (mixed together to form a blended polymer or polymer alloy) is called modified PPO(E) or m-PPO(E).

[0184] "Compatibility" refers to a case where one resin is not compatible with another resin and is dispersed in the other resin, forming an island structure or other structure. For example, rubber B in ABS {a polymer (polymer) in which acrylonitrile and styrene are graft-copolymerized with butadiene rubber} shows compatibility. When two resins are compatible with each other, there is no or only a small decrease in physical properties. In the present invention, compatibility and compatibility are described as compatibility (solubility). Compatibility (solubility) refers to a case where compatibility and / or compatibility are shown.

[0185] {Polypropylene (PP)} The PP that can be used in the present invention will be described. PP is a polymer of propylene, and polypropylene with different stereoregularities (tacticity) such as isotactic, syndiotactic, and atactic is synthesized depending on the difference in stereoregularity. PP is classified into three types of homopolymer, random copolymer, and block copolymer in terms of the form of copolymerization with copolymer (mainly ethylene). Homopolymer is a single polymer of propylene. It is polymerized using propylene and hydrogen as a chain transfer agent. Depending on the difference, it becomes n-butyl group or i(iso)propyl group. In the polymer obtained by metallocene catalyst, ethylene appears to be copolymerized by 2,1 insertion or 1,3 insertion. The melting point of isotactic PP measured by differential scanning calorimetry (DSC) is about 165°C (while the equilibrium melting point is said to be 187.5°C). The higher the tacticity, the higher the melting point. Random copolymers typically contain up to 4.5 wt % ethylene in the copolymer. Terpolymers in which ethylene is further copolymerized with butene-1, and binary copolymers of propylene and butene-1 (without ethylene) are also available. Random does not necessarily mean statistically random. The distribution (randomness) of ethylene in the polypropylene main chain varies depending on the type of catalyst. The ethylene content is not necessarily equal in all molecular weight fractions, and the ethylene content differs between low molecular weight chains and high molecular weight chains. In other words, there is a distribution of ethylene content (copolymer composition distribution). Polymers obtained using metallocene catalysts have a narrower and more uniform copolymer composition distribution than those obtained using solid catalysts. Random copolymers are less crystalline than homopolymers, are transparent, have excellent toughness, and are flexible polymers. The higher the comonomer content (mainly ethylene is the copolymerized monomer), the lower the melting point. Block copolymers are also called impact copolymers or heterophase copolymers. This refers to a composition containing an ethylene-propylene polymer in which ethylene is copolymerized in a subsequent reactor following the polymerization of a homopolymer. Block copolymers have a compatible structure (island-in-sea structure) in which "islands" of ethylene-propylene polymers float in a "sea" of homopolymers. This island-in-sea structure can be controlled by the ethylene fraction and molecular weight of the ethylene-propylene polymer and the molecular weight of the homopolymer. The term "block" in polypropylene does not mean a normal block copolymer unless otherwise specified. In other words, it does not mean that the homopolypropylene chain and the ethylene-propylene copolymer chain are chemically bonded. Block copolymers with an ethylene-propylene polymer content of 40wt% to 50wt% or more are sometimes called reactor-made TPO, reactor TPO, or simply TPo. Block copolymers have better impact resistance than homopolymers. They are less transparent than homopolymers. As mentioned above, examples of PP include polypropylene, ethylene-polypropylene copolymer, propylene-1-butene-ethylene copolymer, propylene-1-hexene copolymer, propylene-1-hexene-ethylene copolymer, and propylene-4 (or 5)-methyl-1,4-hexadiene copolymer. Isotactic PP and syndiotactic PP are crystalline resins, and the crystal structure of isotactic PP is based on a 3 / 1 helical chain and can take on α, β, γ, and other crystal structures. The predominant crystal structure is that of syndiotactic PP, which is an orthorhombic crystal structure based on an 8 / 1 helical chain.

[0186] These PPs are used as molding materials in the present invention, but in addition to using each of them alone as mentioned above, they can also be mixed together to create a blended polymer in order to achieve the desired properties. Blended polymers can be produced at the pelletizing stage, or by mixing the individual materials in the hopper during injection molding and blending them at the stage of weighing in the heating cylinder of the injection molding machine. This is called "mold blending."

[0187] (Master patch of foaming agent for PP) The above PP pellets are also used to support the foaming agent powder. To manufacture the foaming agent, PP powder and foaming agent powder are mixed together, and then the mixture is solidified using a varnish such as maleic acid-modified PP, as in H-processing, and pelletized (supported around the PP pellets). The principle of H processing is as follows. PP pellets are placed in a Teflon-coated frying pan, a cooking utensil, heated to about 80℃, and baking soda powder, for example 20 wt% of the PP pellets, is added. While stirring the pellets and foaming agent to make the inside uniform, a maleic acid-modified PP solution is sprayed from above. The solvent in the maleic acid-modified PP solution evaporates, and as a result, the baking soda is around (on the surface of) the PP pellets, and the maleic acid-modified PP is supported as a binder (for example, acts as glue). After the solvent has sufficiently evaporated, the pellets are taken out and can be used as a master batch of foaming agent with 20 wt% baking soda supported. If the pellets are stuck together, they are sieved to make the particle size uniform. If necessary, they may be crushed.

[0188] Foaming agent manufacturers such as Eiwa Kasei, Sankyo Kasei, and Otsuka Chemical manufacture master batches of foaming agents for PP using the inorganic and organic foaming agents mentioned above and PE (polyethylene), which is compatible with PP, as the carrier resin and base resin, and then sell them commercially (for example, Polythrene EE207 (product name) sold by Eiwa Kasei). A master batch of Eiwa Kasei's foaming agent, Polythrene EE207 (trade name, grade), was added to PP (Noblen AZ864) with 3.5wt% PE added to the base resin. The GCP method described below showed that even when the molded product did not have a swirl mark (code 3) on the surface, a phenomenon similar to a swirl mark (code 2) appeared near the gate (Figure 1). Eiwa Kasei's foaming agent, Polythrene EE25C (trade name, grade, base resin is PE), also showed a similar phenomenon near the gate. FT-IR (infrared spectroscopy) revealed that this swirl mark-like phenomenon was caused by PE in the foaming agent master batch. When ADCA powder (powder-like properties) was spread into pellets using paraffin oil and foam molding was performed using GCP, the phenomenon shown by reference number 2 in Figure 1 did not occur near the gate. Reference number 1 in Figure 1 is the gate.

[0189] For reference, Figure 3 shows swirl marks occurring all over a foam molding (transparent ABS) without GCP.

[0190] As a means to solve this problem, the inventors considered using PP, which is compatible with the PP to be foamed, as the base resin of the master batch of the foaming agent. Even if a single-screw or multi-screw extruder or kneader is used, the melting temperature of PP is more than 20°C higher than that of PE, so the foaming agent to be mixed is thermally decomposed at the melt-kneading stage in these devices, and the function of the foaming agent as a master batch {the amount of foaming gas generated per unit (for example, per 100 grams of the master batch of the foaming agent)} decreases. To solve this problem, we came up with the idea of ​​heating the PP pellets to be foamed on a plate and stirring paraffin oil, stearic acid, a volatile solvent, and foaming agent powder to support the foaming agent (such as ADCA or baking soda) on the surface of the PP pellets. When using a master batch of this foaming agent, since there is no PE, there is no problem with silver spots near the gate caused by PE, as shown in Figures 1 and 2. Towa Chemical Co., Ltd. already possessed the mass production technology for processing colorant master batches for this processing method, so they prototyped a master batch of a foaming agent for PP, using PP, which is compatible with PP, as the base resin and containing 10wt% ADCA and 10wt% sodium bicarbonate as the foaming agent.

[0191] The inventors confirmed that it is possible to manufacture a blowing agent for PP (PP that is compatible and / or tolerant of PP) with ADCA supported around the PP by adding 90 parts of PP pellets, 10 parts of ADCA powder, and 5 parts of Multi Primer EXC-3000 as a binder (this may be added from the beginning, or may be added while spraying or dripping), into a Henschel mixer (product name), and gradually raising the temperature of the mixer from room temperature to 60°C while stirring, thereby evaporating the solvent contained in the Multi Primer EXC-3000. In addition to ADCA, it is also possible to manufacture the primer using sodium bicarbonate or potassium bicarbonate. It is also possible to use emulsion and suspension types of primers whose main component is maleic acid modified resin as a multi-primer (see Example 18).

[0192] 70wt% PP pellets, 20wt% ADCA powder, and 10wt% maleic acid modified PP (ARROWBASE DB-4010 manufactured by Unitika Ltd., emulsion type) were mixed and heated to around 80°C and evaporated to dryness (evaporating the water and other solvents in the emulsion) to produce an ADCA-containing blowing agent master batch. It was also confirmed that it is possible to manufacture a master batch using powdered baking soda instead of ADCA. It was also confirmed that it is possible to manufacture a master batch using sodium dihydrogen citrate, a foam nucleating agent.

[0193] In addition to baking soda, alkali metal salts of hydrogen carbonate, microballoons in the foaming agent sold under the trade name Advancel, hollow fiber spheres, etc. can also be supported on the surface of the resin pellets using this method, making them usable as foaming agents (master batches). Hardlen NZ-1015 (emulsion type, water-based type) sold by Toyobo Co., Ltd. is commercially available and can be used with the amount of maleic acid modification contained (dissolved solid content is about 30 wt%). Maleic acid modified PP {PMA H1100P, PMA-F6 (trade name) are powders, PP powder; ADCA: PMA H1100P or PMA-F6 may be mixed in a ratio of 7:2:1 and heated to about 100°C to melt the maleic acid modified PP, and ADCA may be supported around the PP pellets. Maleic acid modified PP dissolved in an organic solvent (e.g. toluene, alcohol, ketone, etc.) may also be used. Maleic anhydride exists in many molecular structures depending on the functional group. When maleic acid-modified PP is used to manufacture a blowing agent for PP, it can be dissolved in a solvent to produce a varnish, emulsion, or suspension. An emulsifier (surfactant) is used to manufacture emulsions and suspensions, but if the emulsifier has poor thermal stability, it can cause problems with burning and discoloration in the foamed molded product. Use one that does not use an emulsifier or one that has good thermal stability (does not thermally decompose even when exposed to molding temperatures).

[0194] This method allows PE pellets to be supported with maleic acid modified PE. This foaming agent master batch is also used for PE.

[0195] By using the method of making confetti with AS powder or ABS powder, baking soda, and a small amount of water, the resin to be molded can be made into a foaming agent master batch to be used in the foam molding of AS or ABS. It can also be easily manufactured in the same way in the case of PS and HIPS. Using this method, it is also possible to manufacture a colored master batch for PC.

[0196] (Master batch of foaming agent for ABS) The manufacturing method of the foaming agent master batch for ABS is explained. First, ABS is dissolved in a solvent that dissolves ABS, such as methyl ethyl ketone (MEK, 2-butanone, ethyl methyl ketone, n-butanone), to produce doped cement. Next, ABS pellets are placed in a Henschel mixer, followed by foaming agent powder (e.g. ADCA, baking soda, etc.), and the doped cement is sprayed while heating to about 45°C. The doped cement is adjusted to a viscosity that can be sprayed using MEK or other solvents such as toluene as necessary. When drying is complete, a foaming agent master batch with the foaming agent supported around (on the surface) of the ABS pellets is obtained. In the case of a foam nucleating agent (e.g. monosodium dihydrogen citrate), a foam nucleating agent master batch can be obtained by supporting the foam nucleating agent (powdered) instead of the foaming agent in the same way. Urea is a substance that lowers the decomposition temperature of foaming assistants, such as ADCA. If this is also supported in a similar manner, a master batch of the foaming assistant supported by the foaming assistant can be obtained. The binder used for the support was ABS doped cement, but the REPELLE S#1100 in Example 6 is an acrylic paint, and its main component, styrene modified acrylic resin, is compatible with ABS, HIPS, and m-PPO(E), so the varnish used in the manufacture of REPELLE S#1100 (product name) {for example, Acrydic M-1156 (product name), a styrene modified acrylic resin from DIC Corporation} can also be used as a substitute for the ABS doped cement. It does not have to be ABS, but AS (as it is compatible with ABS) can also be used. Of course, instead of solvent type, emulsion type styrene modified acrylic resin can also be used.

[0197] In the case of PS, HIPS, m-PPO(E), HIPS and / or PS doped cement can be used instead of ABS. In the case of PC, PC or ABS doped cement compatible with PC can be used. Of course, emulsion type varnishes or the above doped cements can be used as emulsions. ABS foaming agent master batch using styrene modified acrylic resin can be used for PC. In the case of PC, using sodium bicarbonate or ADCA as the foaming agent, the GCP device of the present invention can obtain a foam with a smooth surface, but the physical properties are significantly deteriorated due to the foaming agent. Effective foaming agents for PC foaming include putting a vaporizable liquid such as ethanol into the molten resin, vaporizing it, and using the ethanol vapor to give it foamability, or putting dry ice into the molten resin (in the case of an injection molding machine, a hole is made in the middle of the heating barrel and an optimal amount is put into the molten resin), allowing it to sublimate, and vaporizing carbon dioxide gas into the PC to give it foamability. This method can also be used with other thermoplastic resins. In this case, the use of a foam nucleating agent allows the formation of finer foam cells.

[0198] As mentioned above, by making separate masterbatches by loading the foaming agent, foam nucleating agent, and foaming assistant agent into pellets, the optimum blend of each masterbatch can be mixed into the pellets before molding, allowing the blend to be easily changed, making it easy to create the optimum foaming conditions. The carrier resin used in the manufacture of masterbatches for HIPS, ABS, and HIPS-modified PPO(E) is, for example, ABS, which has a structure in which butadiene rubber grafted with acrylonitrile floats as islands in a sea of ​​AS. The grafted butadiene rubber is also acceptable, but AS, which forms a sea structure, is used. PS can also be used for HIPS and modified PPO(E).

[0199] In the present invention, the manufacturing method of the blowing agent uses pellets or powder of the resin to be foamed (in the case of PP, powder in the middle of production is also acceptable), and by using the same type of resin, the deterioration of physical properties can be reduced or avoided.

[0200] (Suitable for painting) The PP molded product with swirl marks caused by PE shown in Figures 1 and 2 was first primer treated with Multi Primer EXC-3000 (product name, product number) manufactured by Musashi Paint Co., Ltd., which was used in Example 6, and then topcoated with EC-GPX79-Eco-Highurec Silver (mixture ratio of base agent to hardener is 10:1) (product name, product number) manufactured by Musashi Paint Co., Ltd. The molded product was subjected to a salt spray test (SST) for 240 hours based on the Japanese Industrial Standards (JIS) K5600-7-1, and blisters (swelling) were generated near the area where the PE had emerged.

[0201] When a master batch containing 10wt% of the foaming agent, with the PP as the base resin and ADCA as the foaming agent, was used, the coating suitability (SST) was similarly evaluated. Since it did not contain PE, no blisters occurred and the coating adhesion was good. When baking soda is used as the foaming agent and PP is used as the base resin, no defects near the gate caused by PE are observed. When the paint was applied in the same way and a paint adhesion test (SST) was performed, blisters occurred on the entire surface of the paint film, and good paint suitability was not obtained. A detailed observation of the surface of the foam molded product confirmed the presence of foaming agent residue (unreacted sodium bicarbonate and foaming residue sodium carbonate). Assuming that this foaming residue was the cause of the blistering, the foam molded product was immersed in 1 wt% acetic acid water for 10 minutes before painting, washed with water, dried, and the foaming residue was removed. As a result, there was no blistering of the paint film and the paint film had good adhesion.

[0202] (Removal of foam residue) It has been confirmed that, in order to remove (dissolve and remove) the foam residue on the surface of a foam-molded product using a bicarbonate such as baking soda, the product is immersed in an acidic solution or sprayed onto the surface of the molded product to dissolve the alkali metal carbonates and bicarbonates present on the surface of the molded product and then painted, there will be no swelling or peeling of the paint film. Acids used for pickling include strong acids such as hydrochloric acid, sulfuric acid, nitric acid, and chromic acid, and weak acids such as acetic acid, citric acid, malic acid, and sulfamic acid. Both inorganic and organic acids can be used. The lower the hydrogen ion concentration (PH) of the solution used for pickling, the more effective it is at dissolving the carbonates (removing them from the surface of the molded product); however, a low PH creates a poor working environment, so a PH of 7 or less ensures a good chemical reaction (neutralization reaction between the foamed residue in the molded product and the acid), and the higher the temperature of the solution in the pickling bath, the greater the removal effect. Furthermore, the higher the temperature of the cleaning solution, the greater the removal effect of the foamed residue. The above acids are used alone or as a mixture.

[0203] (Suitability for painting with other foaming agents) Advancel, a commercially available foaming agent, was used on TSOP No. 6 (a resin whose main component is PP, used by Toyota Motors for plastic molded parts in automobiles) and the results of the paint adhesion test confirmed that, like sodium bicarbonate, blisters were generated and paint adhesion was reduced. Fine Blow (product name) also confirmed a similar reduction in paint adhesion. It is speculated that the cause of Fine Blow is the use of sodium bicarbonate as a foaming agent.

[0204] (GCP) GCP is an effective means of eliminating swirl marks that occur on the surface during foam molding. It is a process in which the molding space in the sealed mold shown in Figures 10 and 11 is pressurized to a pressure greater than atmospheric pressure with, for example, air, nitrogen gas, carbon dioxide gas, hydrocarbons such as methane and ethane, and rare gases such as hydrogen, helium, and argon. This process of pressurizing the molding space is called GCP. The act of pressurizing the molding space is also called "pressurizing," and the gas (L1, L2, L3) in the molding space is also called compressed air. The process of pressurizing the molding space, filling it with foamable resin that has been given foaming properties, and releasing the compressed air is also GCP. Compressed air is an effective means of suppressing foaming on the surface and obtaining a foam molded product with a beautiful appearance without swirl marks, but it is troublesome when filling the resin. The force of filling the resin into the molding space pushes it out to the PL, aiming for surface transferability, but if the resin filling speed is too fast, if the surface of the mold is glossy, if the depth is too shallow even after embossing, if the resin temperature is too high, if the viscosity of the molten resin filling the molding space is low, or if the mold temperature is high, the gas in the GCP will be entrained. The entrained gas in the GCP has nowhere to escape and ends up staying on the molding surface, resulting in sink marks (called raindrops in this case). To solve this problem, after exhausting the GCP, open the mold (by moving it backward, recessing, mold back, and core back) to release the GCP gas entrapped on the surface of the molded product to the outside all at once. If necessary, apply a vacuum as shown in Figure 49. It has been said that a gas vent of about 0.05 should be provided in the PL of the mold, but sintered metal (part numbered 149 on the right side of Figure 50) may also be provided in the PL. In this case, since sintered metal has low strength, it is used by sandwiching a part of it between something with high strength (hardness). The parting may be multi-layered (part numbered 150 on the left side of the PL in Figure 50) to facilitate smooth exhaust of gas (Figure 51). As shown in Figure 51, a gas vent (reference number 153) may be provided in the center of the mold. In this case, the gas vent 153 is covered with molten resin, so the gas exhaust action and effectiveness are low. Exhaust from parting is effective. The molds shown in Figures 10 and 11 have a nested structure (reference number 23, etc.), so it is possible for pressurized air to enter the molding space, and it has the same effect as reference number 153. Since partial exhaust is possible, it is absolutely necessary to install a gas circuit (for example, Figure 39, etc.) in the PL.

[0205] (Principle of GCP) The principle of GCP will be explained using carbonated water shown in Figure 6. Carbonated water is made by dissolving carbon dioxide gas under pressure in water, with the plug at the top (reference number 5) closed, and the carbon dioxide gas is pressurized and dissolved in reference number 7 (solvent water) by the pressure (reference number 6) applied to the part at reference number 6. The carbonated water (reference number 7) inside is in a supersaturated state with carbon dioxide gas at atmospheric pressure. When the stopper 5 is opened, the pressure at 6 becomes atmospheric pressure, and the excess dissolved carbon dioxide gas turns into gas and foams. If we were to replace carbonated water with the heating barrel of an injection molding machine, the plug at number 5 would be the shut-off nozzle. The container (bottle, PET bottle) at number 8 is the heating barrel. When the foaming agent and the resin pellets to be molded are mixed in a hopper and heated to melt, the foaming agent thermally decomposes and generates foaming gas. When a back pressure of a certain level or more is applied during the plasticization and metering stages, the foaming gas is finely dispersed in the molten resin in the heating barrel, or dissolved under pressure. Typical foaming gases include nitrogen gas, carbon monoxide, carbon dioxide gas, water vapor, and vapors of organic solvents such as alcohol. Nitrogen gas has low affinity (solubility) with thermoplastic resins, so much of it disperses finely in the resin. Carbon monoxide and carbon dioxide have high affinity, so much of it dissolves in the resin. Water vapor has a solubility roughly intermediate between that of nitrogen gas and carbon dioxide gas. Alcohol vapor has an extremely high affinity with resins, and using alcohol vapor as a foaming gas increases the fluidity of the molten resin. The foaming gas in the heating cylinder is governed by Henry's law and Boyle's law. The former, Henry's law, applies to gases that have a high affinity with molten resin, such as carbon dioxide, while the latter, Boyle's law, applies to gases such as nitrogen, which have a low affinity with molten resin.

[0206] (GCP mold) The principle of GCP will be explained using beer in which the same carbon dioxide gas as the carbonated water is dissolved under pressure (Figures 7 and 8). If you open the door (number 11) in the space (number 10) partitioned off by 9 and pour beer into a glass at atmospheric pressure {1 atm (atom)}, beer bubbles (number 12) will appear at the top of the glass as shown in Figure 7. Next, close the door (number 11) and pressurize the partitioned space (number 10) with air at 10 times atmospheric pressure (10 atm) using a compressor or similar device. Even if you pour beer into a glass in this pressurized atmosphere, the beer will pour without foaming because 10 atm pressure is being applied from the outside (Figure 8). Next, the door 11 is opened and the pressure in the space 10 is suddenly reduced from 10 atmospheres to 1 atmosphere, causing the carbon dioxide to dissolve under pressure. The supersaturated carbon dioxide follows Henry's law, and the external pressure of the carbon dioxide gas (dissolved) trapped in the water decreases, resulting in the carbon dioxide gas coming out into the beer. This is the principle of GCP. In the case of nitrogen, the foaming gas, whose volume has been reduced by the pressure of the compressed air, no longer has external pressure (GCP pressure, which corresponds to the pressurization inside the mold), and the compressed air is exhausted, causing the volume to expand.

[0207] A concrete implementation method in injection molding will be described. The manufacturing method of foamable resin is to give foamability to thermoplastic resin by mixing the resin pellets to be molded (not limited to pellets, powder or bulk is also acceptable, and the shape does not matter as long as it can be plasticized in the heating cylinder of the molding machine) and the above-mentioned gas, liquid or solid foaming agent in a desired ratio {The ratio of the foaming gas to the volume of the resin to be foamed is 25vol% to 250vol%, but if the pressure of the compressed air is low, the force (pressure) suppressing the foaming power is low, so it is not possible to put in a lot of foaming agent. On the other hand, if the pressure of the compressed air is high, a lot of foaming gas can be pressurized and dissolved and finely dispersed. When air is used as the GCP, the pressure should be about 2MPa, and the same is true for nitrogen gas. When carbon dioxide gas is used, it is easy to liquefy, so it is better to use a pressure slightly lower than the critical pressure at the temperature of the compressed air.} (In the case of a liquid, it may be impregnated into the resin to be foamed. For example, if ABS is immersed in water and molded while impregnating it with water, the water in the ABS will vaporize at the temperature inside the heating cylinder (the temperature of the heating cylinder, screw, and molten resin) and act as a foaming agent. Water may be impregnated into silica gel or the like and mixed with pellets. In the case of gas, it is plasticized and placed in the molten resin to give foaming properties to the heated and melted resin. Of course, liquid foaming agents may also be placed in the heated and melted resin in the same way as gas, to give foaming properties to the heated and melted resin. In the case of solid foaming agents, they are mixed with pellets and put into the hopper, but they may also be placed in a hole in the heating cylinder. For example, solid carbon dioxide gas (dry ice (in this case, there is no foaming residue, so there is no effect on the adhesion of the coating film.)) can be placed in the molten resin inside the heating cylinder and sublimated to give foaming properties to the molten resin inside. Of course, chemical foaming agents such as baking soda and ADCA can also be used in the same way as dry ice. The foaming agent is heated and melted to plasticize, and during this plasticization stage, it vaporizes and pyrolyzes to generate foaming gas, which is then finely dispersed and dissolved in the molten resin that has been heated and melted in the heating barrel. In order to finely disperse the gas, it is advisable to increase the pressure applied to the molten resin in the heating barrel. In order to pressurize and melt the resin, it is generally advisable to increase the back pressure during plasticization and increase the screw rotation speed.The screw shape should desirably be of a high mixing type, and if necessary, a screw with a dalmage can be used, which will make it easier for the foaming gas to be finely dispersed in the molten resin, resulting in finer and more flexible internal foam cells in the resulting foam-molded product.

[0208] The foaming agent may be in the form of gas, liquid, or solid. For gaseous foaming agents, they are placed in a heating cylinder and dispersed by a screw, so specifications such as Dulmage are necessary. For liquid and solid foaming agents, gas is generated at the molecular level (mainly vaporization in liquids, and mainly thermal decomposition in solids), which then condense and become a foaming gas, so Dulmage is not necessary. It does not cause any problems if it is present. For solid foaming agents, they are mixed into the resin pellets as a master batch in advance, and then plasticized, so Dulmage is acceptable, but is not used in most cases. This article describes the means of finely dispersing the foaming gas generated by a gaseous, liquid, or solid foaming agent in the molten resin in the heating cylinder. The screw used for plasticization should have a high mixing ratio, and a screw with a large L / D should be used. By applying high back pressure and performing plasticization (melt-mixing) for a long time, the foaming gas will be finely dispersed in the molten resin. When plasticization (metering) is performed in this way with increased back pressure, the back pressure and foaming pressure (plasticized resin in the heating barrel that has been given foaming properties) cause the molten resin in the heating barrel to leak out from the tip of the nozzle. To solve this problem, a shut-off nozzle is used that has a spring-loaded air cylinder, hydraulic cylinder, mechanical mechanism, or some other means. Even after metering is complete, it is necessary to continue applying pressure to the molten resin in the heating barrel until the next injection to prevent the molten resin in the heating barrel from foaming inside the heating barrel, thereby suppressing foaming inside the heating barrel. This is called back pressure blocking (end back pressure). The function of the shut-off nozzle here is the same as that of the plug referenced 5 above. There are valve gate type hot runners that have the same function as the shut-off nozzle and open and close using hydraulic, pneumatic or other mechanical (such as actuator) means.

[0209] There are two types of mold structures for GCP: the ejector box type (Fig. 10) and the type in which the ejector turbine is sealed with a load-type O-ring (Fig. 11). Each structure will be explained using Fig. 10 and Fig. 11. First, we will explain the ejector box type (Figure 10). In Figure 10, reference number 16 is a spool bush, reference number 17 is the mounting plate on the fixed side, reference number 18 is a template that houses the fixed side insert, reference number 19 is the fixed side insert, and reference number 20 is the mating surface of the fixed side insert where gas enters and exits (gas passes easily through because it is a mating surface). Reference number 21 is the cavity (molding space) that is filled with molten resin, reference number 22 is a template that houses the movable side insert, reference number 23 is the movable side insert, reference number 24 is the ejector pin, reference number 25 is the ejector plate (upper) that fixes the ejector pin, reference number 26 is the ejector plate (lower) that fixes the ejector pin, reference number 27 is a spacer block with a sealing function, support pillar, reference number 28 is the mounting plate on the movable side, and reference number 29 is the hole in the ejector rod. Reference number 30 is the mating surface of the movable insert, and reference number 20 is the mating surface of the fixed insert, through which gas enters and exits (because it is a mating surface, gas can easily pass through).

[0210] To make a mold into a sealing mold, an O-ring must be placed in each gap (mating surface), and reference number 31 is the O-ring placed on the spool bush, reference number 32 is the O-ring placed on the fixed side mounting plate, and reference number 33 is the O-ring placed on the parting. The cross sections of these O-rings are not limited to being circular, but can also be triangular (△), square (□), or polygonal. V- or U-shaped ones are also acceptable. The insert that forms the cavity on the movable side is divided into a sub-insertion (reference number 23), a sub-insertion (not shown), etc., which are fixed to the mold plate reference number 22 with bolts (not shown). For example, even if the GCP (compressed gas) inlet and outlet circuits (both are the same circuit) provided in the parting are pressurized with air into the cavity, gas leaks out from the gaps in the inserts and the gaps in the ejector pins. Therefore, in order to seal gas leakage from the gaps in the inserts and the gaps in the ejector pins, the spacer block reference number 27 is shaped like the Japanese katakana character "ロ" and encloses the entire ejector mechanism (reference number 34). This mold structure is called an ejector box. Due to the mold structure of this ejector box, reference number 35 is an O-ring provided between reference number 22 and the ejector box-shaped spacer block reference number 27, and reference number 36 is an O-ring provided around the hole of the ejector rod to seal when the ejector plate (ejector mechanism reference number 34) retracts.

[0211] In Figure 10, the parting and ejector plate are movable, so the O-rings (reference numbers 33 and 36) must be fitted into a dovetail groove (reference number 39) in order to prevent them from coming off. In Figure 12, reference number 38 indicates either the O-ring 33 or 36 (Figure 12). In FIG. 11, since there is no need for an ejector box (the space sealed with reference number 27, which corresponds to L1 in FIG. 13), reference number 37 is a spacer block of ordinary shape (simple square block shape).

[0212] In the case of Fig. 10, the ejector mechanism (34) is enclosed by the reference number 27, and the space formed by this (volume to be pressurized with air, etc.) is large, so a large amount of gas is required for pressurization. Even if the gas is air, it is not economical, but if nitrogen gas, carbon dioxide gas, etc. is used for pressurization, a large amount is used and consumed, so it is not realistic. When using expensive gases such as nitrogen gas or carbon dioxide for the pressurized air, they may be recovered and reused later, but great care must be taken as there is a risk that monomers in the resin may get into the gas and cause contamination or problems with the booster device.

[0213] If the ejector pin is sealed using the load type O-ring (packing, seal) having a U-shaped (concave) groove shown in Figures 24, 25, 26, 27, and 28 of the present invention instead of the ejector box indicated by reference number 27, the amount of gas required for pressurization can be reduced, thereby solving the above-mentioned economic problem. For the seal of the ejector pin, a U-shaped packing as shown in FIG. 27 and a load-type O-ring with a U-shaped spring 85 (inserted for the purpose of a load function (tightening on the inside)) as shown in FIG. 24, FIG. 25, and FIG. 26 (e.g. Omniseal (product name), Variseal (product name)) are effective. Instead of the U-shaped spring (85), a general-shaped spring as shown in FIG. 29 or a commercially available O-ring as shown in FIG. 30 may be used. The materials for the U-shaped packing and the load-type O-ring are preferably Teflon (product name) with high sliding properties, a material in which Teflon contains about 10 wt% graphite to enhance sliding properties, Turcon (product name), and silicone rubber, but urethane rubber, nitrile rubber, etc. may also be used. As shown in Figure 36, the one-sided seal (tightened on the inside) has a strong sealing force and can maintain sufficient airtightness even at low pressure. The O-ring 42 is used by fitting it into the ejector pin and supporting it in place, so it is fitted between the plate 40 (top) and the plate 41 (bottom). An O-ring (38) for sealing is inserted between the plate 40 (top) and the mold plate that holds the movable side insert 22. In Figure 11, an O-ring is also placed between the plate 40 (top) and the plate 41 (bottom) just to be safe, but this is not necessary because there is a load-type O-ring 42. In the case of an inclined core, sealing is only required when the mold is closed (PL is mated), so the lower side can be made cylindrical and sealed with a load-type O-ring as shown in Figures 24 to 28. Also, a shape can be created at the front of the inclined core, and an O-ring can be placed to seal when the die is closed. The GCP die structure only needs to perform the sealing function when the die is closed, and in the case of a slide core using an angular pin, the O-ring (reference number 33) placed on the PL is placed (provided) inside. The same applies to hydraulic, pneumatic, mechanical, and other slide cores. When sealing is required on the parting surface of the slide core, sealing is performed in the same manner as the above-mentioned parting.

[0214] In Figure 36, reference number 112 is a one-sided load seal, called an "L-shaped seal." The material is Teflon (product name) with high sliding properties such as PTFE, or a material made by mixing 5 wt% to 25 wt% graphite with Teflon, but other materials can also be used. Reference number 113 is a commercially available O-ring {material is NBR (acrylonitrile butadiene rubber, nitrile rubber)} for the purpose of loading reference number 112, but the coil spring shown in Figure 29 can also be used. The L-shaped seal is housed in a housing 114 formed by reference numbers 40 and 41, and the detailed shape of reference number 114 is described in detail in Figure 48 (Table 15). EP in Table 15 is the abbreviation for ejector pin, and indicates the EP diameter (symbol d) and h9 (fit tolerance). The K seal number is the management number of the L-shaped seal with a shape suitable for each ejector pin, D (diameter) +0.05, L (depth) +0.2, S (gap) fit tolerance is H7 / f8, C (mouth C shape) is 0.3, and r (root R shape) is a maximum of 0.4 (0.4Max). The notes include points to note when inserting the ejector pin into the K seal. Each of these symbols in Figure 48 is associated with Figure 36.

[0215] In FIG. 11, the ejector pin is sealed with a load-type O-ring by sandwiching the number 42 using the numbers 25 and 26. In FIG. 37, the ejector pin 24 is sealed by sandwiching the number 42 in the same manner using the seal (holding) block (upper) with the number 116 and the seal (holding) block (lower) with the number 117. This means is different from FIG. 11, and shows a means for sealing one ejector pin (inclined pin, inclined slide) (respectively). The number 115 is an O-ring, which plays the role of the number 118 or number 119 O-ring. In FIG. 37, for example, it is provided at the bottom of the movable side mold plate, and the plate and bolts for fixing the number 115 are not shown.

[0216] (GCP Process) The GCP device is almost the same for both molds sealed with an ejector box structure and molds sealed with a load-type O-ring on the ejector pin (a sub-tank 55 is provided for molds sealed with a load-type O-ring). (1) Close the mold, (2) touch the nozzle, (3) inject gas compressed by a compressor into the mold (pressurized air = this is sometimes called GCP), and (4) fill the cavity with foamable resin (molten resin made foamable using a physical foaming agent or chemical foaming agent) while still pressurized. The timing of the start of filling is determined by a method such as monitoring the pressure of the gas injected into L2 and starting injection (filling) after confirming that the desired pressure has been reached. (5) During or after filling, the compressed gas is exhausted or collected in a separate container, and (6) when cooling of the foamable resin in the mold is completed, the mold is opened and removed. The means of obtaining a foamed molded product with a beautiful appearance without swirl marks on the surface using this technique is called the GCP method, and the process is called the GCP process. In this invention, GCP refers to the series of processes mentioned above {mold closing → gas injection into the mold → filling (injection) foamable resin → exhaust, etc.}, and the introduction of gas into the mold (into L1, L2, L3, etc.) for the purpose of suppressing foaming is referred to as "applying air pressure, applying GCP, applying GCP, pressurizing GCP, applying GCP," etc. "Air pressure" can also refer to the gas introduced into the mold (into L1, L2, L3, etc.).

[0217] (GCP device) L1 in Fig. 13 is the space housing the ejector mechanism 34 surrounded by reference number 27. In Fig. 14, it is the space provided at the bottom of the movable insert (the space surrounded and sealed by reference numbers 33, 118, 119, and 42). In both Figs. 13 and 14, L2 is the cavity space (reference number 21). L3 is the space sealed by reference numbers 32 and 33 provided at the bottom of the fixed insert (Figs. 13 and 14). When reference numbers 40 and 41 in Fig. 14 are used, O-rings corresponding to reference numbers 118 and 119 must be placed, just like on the movable side. The role of L1 and L3 is that when L2 is filled with molten resin, compressed air is an effective means of suppressing foaming, but it also prevents the molten resin from filling L2, causing short molds, discoloration, burns, etc. To solve this problem, the spaces L1 and L3 exist, and the force of filling L2 with molten resin pushes the gas in L2 into this space, preventing the pressure in L2 from becoming abnormally high, eliminating problems such as short molds, discoloration, and burns.

[0218] Figure 15 shows the GCP device, where reference number 43 is the injection (compressed air) valve (reference number 46) that injects (compressed air) gas compressed to above atmospheric pressure by an air compressor into the mold at the right timing as described above. Reference number 51 is an exhaust valve that exhausts the pressurized air put into the mold. Anticipating trouble due to power outages and the like, the inventors selected a normally closed type for the injection valve 46 and a normally open type for the exhaust valve 51 for safety reasons. With this combination, the compressed air being sent to the mold in the event of a power outage stops immediately, and the compressed air sent into the mold is immediately exhausted, preventing accidents such as the mold opening due to the pressure of the compressed air inside the mold. The device in FIG. 15 is operated by a separately provided controller (not shown), or by incorporating the program of this controller into the controller of the molding machine, according to those commands (injection and exhaust of compressed air, etc.). The GCP device in Figure 15 is a simple device with one injection valve and one exhaust valve, and is connected to the spaces L1 to L3 with a flexible hose (reference number 52). In this case, injection and exhaust into the spaces L1 to L3 are performed by this hose. Depending on the size and shape of the molded product, three devices like those in Figure 15 may be prepared and used. In some cases, even more devices may be used. First, a means for implementing GCP using one device in Fig. 15 will be described. Multiple hoses 52 are connected to manifold 49. The ends of hoses 52 are connected to spaces L1 to L3 of the mold in Fig. 13 (mold with ejector box structure). In this case using one GCP device in Fig. 15, the inflow (injection) and outflow (exhaust) of compressed air into spaces L1 to L3 are performed simultaneously. Reference number 44 indicates a circuit connecting reference number 43 and reference number 46 (usually a flexible hose is used, although a steel pipe is also possible), reference number 48 indicates the part that connects to hose 52, which is generally a one-touch coupler (the inventors use a male shape for this coupler for the manifold and a female shape for the end of the hose. Although it is standardized as male for molds, this is not always the case). The → (arrow) of reference number 53 indicates the direction of the flow of compressed air, reference number 54 indicates that the same hose is used for both the compressed air entering and exiting the mold, and reference number 47 indicates that the compressed air is exhausted into the atmosphere.

[0219] When three units of the device shown in Fig. 15 are prepared for the mold shown in Fig. 13 and connected to the spaces L1 to L3 separately, it is possible to inject gas simultaneously after the mold is closed, and exhaust gas with a time lag. When one unit of the device shown in Fig. 15 is used to connect to the spaces L1 to L3, it is called one-stage exhaust (one-stage exhaust). When three units of the device shown in Fig. 13 are prepared, they are connected to the spaces L1 to L3, and exhaust gas with a time lag is called three-stage exhaust (three-stage exhaust), which is effective for molded products with complex shapes. When exhausting L1 and L3 first, and then exhausting L2 with a slight delay, it becomes easier to suppress (control) swirl marks. The GCP device in Fig. 16 differs from the GCP device in Fig. 15 in that it has a sub-tank indicated by reference number 55. The GCP device in Fig. 16 transfers the gas in the mold structure L2, in which the ejector pin shown in Fig. 14 is sealed with a load-type O-ring or the like, to this sub-tank (reference number 55), and this sub-tank 55 has the function of preventing the pressure in L2 from becoming abnormally high. In the case of Figures 10 and 13, this is not necessary because the ejector box L1 serves as a sub-tank, but for large molded products, the volume of the ejector box L1 becomes large, so more pressurized gas is required and the time required for pressurization is longer, resulting in higher processing costs and being uneconomical. To solve this problem, the ejector pin seal (using a load-type O-ring) using reference number 42 requires less gas and shorter time, but when molten resin is filled into L2, there is little space for the pressurized air in the cavity to escape, so the pressure in L2 becomes abnormally high (rises, rises), causing short molds, discoloration, and burning. This problem can be solved by providing a sub-tank 55 to the GCP device. A pressure gauge with the reference number 56 is provided in Figures 15 and 16. If the pressure and pressure rise state of the compressed air in each of the spaces L1, L2, and L3 are measured visually or with other measuring devices, or if injection is started when the compressed air reaches a preset pressure, the time from compressed air to injection can be shortened, and loss time (extra time) is almost eliminated, so that productivity can be improved compared to the mold structure in Figure 10. Also, by monitoring the pressure, it is possible to monitor the occurrence of defects due to insufficient compressed air pressure.

[0220] (Quick exhaust valve) To exhaust the compressed air inside the mold more quickly, a quick exhaust valve such as CKD Corp.'s QEV2 series (product name) or SMC Corp.'s Quick Exhaust Valve AQ series (product name) can be used to install in the mold a quick exhaust valve that increases the speed at which the compressed air can be exhausted.

[0221] (Connection between GCP device and sealing mold, etc.) Figure 11 specifically shows the connection between the mold with the sealed ejector pin and the GCP device shown in Figure 16. Reference number 127 is a circuit provided in the mold for introducing compressed air into the L1 space, filling it with foamable resin, and discharging the compressed air during and after the filling is completed. Reference number 126 is a circuit provided in the mold for introducing compressed air into the L2 space, filling it with foamable resin, and discharging the compressed air during and after the filling is completed. Reference number 125 is a circuit provided in the mold for introducing compressed air into the L3 space, filling it with foamable resin, and discharging the compressed air during and after the filling is completed. Reference number 128 is a one-touch coupler provided in each circuit.

[0222] Reference numerals 118 and 119 denote O-rings, and reference numeral 120 denotes a one-touch coupler provided on a pipe 121 from a compressor that guides the compressed air of the compressor 43, which sends compressed air to the respective L1 to L3 spaces, to the GCP device. Reference numeral 122 denotes a GCP device that introduces and exhausts compressed air to L3, reference numeral 123 denotes a GCP device that introduces and exhausts compressed air to L2, and reference numeral 124 denotes a GCP device that introduces and exhausts compressed air to L1. As described above, the entry and exit to and from the L1 to L3 spaces in the mold are controlled to open and close by the injection molding machine or a separately provided controller. In Fig. 38, the GCP device shown by reference numbers 122 to 124 is connected to the mold shown in Fig. 11 to enable multi-stage exhaust, but if the shape is not complicated, one GCP device shown by reference numbers 122 to 124 may be used and L1 to L3 may be connected to a coupler 48 attached to, for example, 123 to achieve single-stage exhaust. Of course, there is no problem if the GCP device shown in Fig. 16 is used for the mold shown in Fig. 10.

[0223] The means for allowing compressed air to enter and exit the L2 space (cavity) will be explained. Figure 39 shows a front view of the parting surface on the fixed side. Reference number 129 is a groove dug outside the product shape, and the inventor has made it about 8 mm wide and 3 mm deep, but the shape is not so important as long as it does not cause a large resistance to the inflow and outflow of compressed air. Reference number 130 is a gas vent connected to reference number 129, and the inventor has made it about 5 mm wide and 1 mm deep, but the shape is not so important as long as it does not cause a large resistance to the inflow and outflow of compressed air. Reference number 131 is also a gas vent, but since it is directly connected to the product shape (molding space), it is shaped so that compressed air can easily pass through but molten resin cannot pass through. In the case of styrene-based resins such as ABS, which have a relatively high viscosity of molten resin, the inventor has made it about 5 mm wide and 0.05 to 0.1 mm deep. In the case of resins with low viscosity of molten resin such as PP, the inventors set the width to about 5 mm and the depth to about 0.02 mm to 0.05 mm. The depth of the gas vent with reference number 131 is optimal so that the compressed air can flow in and out without resistance, but no burrs are formed. In the foam molding of the present invention, no resin dwell pressure is used, or if one is used, it is low pressure and short time (for example, about 30% of the maximum injection pressure, pressurization time about 0.5 to 2 seconds), and the amount of foamable resin filled into the molding space with the primary filling speed and pressure is the same as the volume of the molding space, or the amount of foamable resin filled is less than the volume of the molding space, so that even if a gas vent is provided, the generation of burrs is not so great.

[0224] FIG. 40 is a side view of FIG. 39 showing the connection of the compressed air circuit 128 to L2 with the open compressed air passages in the mold at 132. Figure 41 shows the L1 space in Figure 11 and the L3 space in Figures 10 and 11. Figure 41 will be explained as the L1 space in Figure 11. Reference number 132 indicates the portion where reference number 40 contacts the bottom of reference number 23. Reference number 134 is a groove where compressed air passes, and reference numbers 133 and 134 are holes opened in reference number 40 (the compressed air circuit corresponding to reference number 127), which are the circuits for the inflow and outflow of compressed air. The mating surface 30 of the reference number 23 is also machined in the same shape as the reference numbers 131 and 130 to provide a sufficient gas vent {when the foamable resin in the molding space is filled, the pressure (force) will smoothly push out the compressed air, eliminating problems such as short mold, discoloration, and burning}. This gas vent is connected to the reference number 134.

[0225] Figures 38, 39, 40, and 41 show that since it is connected to L1 to L3 in Figure 10 or 11, when compressed air, for example, is used as the compressed air by the compressor 43, the inlet and outlet can be performed without resistance. If nitrogen gas is connected to the intake port of the compressor 43, nitrogen gas GCP can be implemented.

[0226] In Figures 39 and 40, the compressed air in the molding space is provided by setting up a gas circuit on the mating surface of the PL, and the compressed air enters (compressed air) and exits (exhaust) through the gap, but although there are means for providing compressed air and exhaust in the non-decorative part of the molded product (mainly the working side where the ejector pin marks are), the compressed air and exhaust are more smoothly provided from the parting. For reference, Figure 50 shows Figure 51, which shows the compressed air and exhaust circuit installed in the center of the product, and the explanation has been given above.

[0227] (Amotec, Nitrogen Gas GCP) The device in Figure 16 is equipped with a check valve 58. The function of this check valve is that, for example, by pressurizing the air to about 1 MPa using inexpensive air beforehand, and then pressurizing the L2 space to about 2 MPa using nitrogen gas from a separately installed device and circuit, the oxygen concentration in the L2 space decreases, so discoloration and burning can be reduced in GCPs using inert gases or gases with reduced oxygen concentration. In the above method, GCP uses carbon dioxide instead of nitrogen, and the carbon dioxide gas melts into the molten tip of the foamable resin, improving the transferability to the mold and the induction of the molten resin. In composite materials containing glass fibers, the floating of the glass fibers is suppressed, resulting in a beautiful appearance. The check valve 58 is a commercially available reciprocating type compressor {with receiver tank (not shown)} with a pressure resistance of about 1.4 MPa, and of course a safety valve (not shown) is provided, but since it is dangerous to apply a pressure higher than the compressor's pressure resistance to L2, it is provided to prevent nitrogen gas, carbon dioxide gas, etc. that will be applied to the compressor later from entering. Of course, for safety reasons, the GCP devices of Figures 15 and 16 are equipped with a safety valve (not shown) on the manifold 49. The device of Figure 16 can be used with either the mold of Figures 13 or 14. The method of connecting one GCP device of Figure 15 to the mold of Figure 13 and the method of connecting three devices to use have been explained above, but the mold of Figure 14 and the GCP device of Figure 16 can also be used with one or three GCP devices to perform one-stage exhaust or multi-stage (for example, three-stage) exhaust.

[0228] (Injection molding machine control) The details of the control of the GCP device shown in Figures 15 and 16 are shown. First, the foamable resin manufacturing method, in other words, the details of the means for imparting foamability to molten resin in the heating barrel of an injection molding machine, are shown. First, the solid foaming agent ADCA, or in the case of powder such as baking soda, is used by spreading it on pellets. For example, the resin pellets to be foamed are placed in a tumbler, the required amount of foaming agent is added, and a small amount of paraffin oil, which acts as a spreading agent, is added to spread the foaming agent, and tumbled, and the foaming agent powder is spread around the resin pellets. This is put into a hopper and sent into the heating cylinder, where it is heated and melted, causing the foaming agent to thermally decompose and generate foaming gas, which is then finely dispersed in the molten resin by the force of the screw rotation in the heating cylinder and the back pressure applied to the molten resin in the heating cylinder. Because the pressure applied to the molten resin is high, it is also pressurized and dissolved. Since blowing agents are difficult to handle in powder form, when the blowing agent is in pellet form, it is simply kneaded into or supported by pellets of the resin to be foamed. The blowing agent pellets (master batch) and the pellets of the resin to be molded are mixed in a tumbler and then put into a hopper in the same way to produce the foamable resin.

[0229] (screw) To pressurize and dissolve and finely disperse the foaming gas in the molten resin in the heating barrel, a high degree of mixing is required, and the compression ratio (CR) is about 2.4 to 4, and in the case of engineering plastics, it may be 4 or more. The effective length {L (total length of the screw) / D (diameter of the screw)} is 15 or more, preferably 18 or more, and the larger L / D (value obtained by dividing L by D) is, the higher the degree of mixing becomes, which is useful for pressurizing and dissolving and finely dispersing the foaming gas in the molten resin. The screw is divided into zones: the supply section, compression section, and metering section. When performing general solid molding, the supply section is about 1 / 2 the length, the compression section is 1 / 4 the length, and the metering section is about 1 / 4 the length, but in foam molding, the compression section is made as long as possible to make it 1 / 4 the length, so that the foaming gas can be pressurized and dissolved and finely dispersed sufficiently. By lengthening the compression section, the aforementioned L / D is increased, which allows the compression time of the molten resin to be increased. Other measures include making the screw's flights shallow to achieve high mixing, or using double flights.

[0230] As is clear from the pressure of the GCP, if there is pressure from the outside, it is possible to confine the foaming gas, but the higher the back pressure during plasticization (metering), the more uniform and finely the foaming gas will be pressurized and dissolved and finely dispersed in the molten resin in the heating barrel. The back pressure in this invention varies depending on the type of resin and foaming agent used, but generally, the back pressure during metering (plasticization is performed to pressurize and dissolve the foaming gas in the resin and finely disperse it) should be 5 MPa or more. The inventor sets the back pressure as high as possible, slightly lower than the pressure at which the shut-off nozzle used drips during metering. If the back pressure is turned off after metering is completed, foaming (pre-foaming) will occur in the heating barrel, so it is necessary to keep the back pressure {end back pressure (EBP)} applied until the start of injection. In that case, the EBP pressure should be about 5 MPa. In this example, a screw design was used with a CR of about 3 and an L / D of 18. In the case of a φ60 full-flighted screw, the flight section length is 1,560 mm, the supply section length is 480 mm, the compression section length is 540 mm, the metering section length is 540 mm, the CR is 3, the supply selection groove depth is 8.3 mm, the metering selection groove depth is 2.5 mm, the flight width is 6 mm, and the angle of the screw tip is about 90° to 30°.

[0231] In the case of a liquid foaming agent such as an aqueous solution of hydrogen carbonate such as ethanol or sodium hydrogen carbonate, a hole is opened in the heating cylinder to provide an inlet with a valve or an inlet with sintered metal embedded therein, and the liquid is injected into the resin heated and melted in the heating cylinder simultaneously with the start of metering or after a short delay, and vaporized by the temperature (thermal energy) of the heating cylinder and the temperature (thermal energy) of the molten resin, evaporated to dryness, and thermally decomposed to generate a foaming gas, imparting foamability to the molten resin in the heating cylinder. The injection of the liquid is stopped either before the completion of metering, simultaneously with the completion of metering, or after a certain time has elapsed since the completion of metering. The injection of the liquid may be stopped once during metering as necessary. The means for imparting foamability by introducing a gas such as MU-CELL or AMOTEC into the heating cylinder and dispersing it in the molten resin in the heating cylinder is also approximately the same as in the case of the liquid.

[0232] The actual program in the injection molding machine is such that (1) metering begins and this is considered a zero start, (2) a delay time is set until the start of liquid and / or gas injection (if it is zero, it will occur simultaneously with the start of metering), (3) the screw position is monitored from the start of metering, and if injection is to be stopped midway through metering, the screw position is set, (4) if re-injection is to be started, the screw position for starting re-injection can be set, (5) if injection is to be stopped before metering, the command to stop injection is set as the screw position, and (6) if injection is to be stopped simultaneously with the completion of metering, or if injection is to be delayed, a delay time can be set (if it is zero, it will occur simultaneously with the completion of metering). This signal is sent to a separate liquid injection device and gas injection device. In the case of gas injection, the injection valve is opened and closed, and in the case of liquid injection, the plunger is pushed or stopped, and commands are sent from the injection molding machine program, and actuators, for example, operate in conjunction with the commands.

[0233] (Methods for increasing foaming ratio) There are several ways to increase the expansion ratio, including reducing the pressure of the foamable resin filled in the mold. For example, instead of filling the cavity to the full extent, filling a small amount of resin, so-called a short shot, reducing the pressure by retracting the screw (sucking back) immediately after filling the cavity with the foamable resin, and reducing the pressure of the foamable resin filled in the cavity by expanding part of the mold after filling it with the foamable resin, which is called an expansion core. In this case, the expansion ratio (defined in this invention as the percentage of 100 - volume of foam molded product ÷ volume of solid molded product. The expansion ratio is also called the weight reduction ratio) is not very large because the cavity volume does not change. To obtain a large expansion ratio, it is better to use core-back and mold-back (both structures in the mold are used (openings such as round holes may get into the openings when the mold is opened if they are not core-backed, so in this invention, core-back is used). When GCP is used, it is performed simultaneously with the start of GCP evacuation, during GCP evacuation, immediately after GCP evacuation is completed, or with a slight delay. Both core-back and mold-back have similar mold movements (mold opening), but as shown in Figures 17 and 18, when the parting at No. 60 (the surface where the fixed side mold and the movable side mold meet) is vertically cut (the fixed side mold and the movable side mold are cut by metal as shown in No. 62. In Figure 53, the molds are not cut by metal), it is called core-back, and when the parting at No. 60 is horizontally cut as shown in Figures 19 and 20, it is called mold-back.

[0234] (Control of molding machine when multiple GCP devices are installed on one mold) When performing GCP by installing the GCP devices shown in Fig. 15 or Fig. 16 at L1, L2, and L3 in the spaces shown in Fig. 13 and Fig. 14, the start of pressurization into the molding space of the mold is similarly done by a mold closing completion signal, etc. In other words, the opening of valve 46 is done at the same time. The difference is that if only one unit is connected at the exhaust timing, only valve 51 is exhausted, so the compressed air in L1, L2, and L3 is exhausted all at once. If one unit is connected each to L1, L2, and L3, the exhaust timing can be changed. The exhaust signal is done by the screw position, exhaust timer, etc., and the PLC of the molding machine has a program installed that can control multiple units. After evacuation, the mold back, core back, mold retraction, and molded product removal are all performed with a single signal, just like in the case of a single machine.

[0235] {Liquid and gas injection from a nozzle {Sinbo (Professor Emeritus Minoru Nibo of Kanazawa Institute of Technology) process} In the case where gas or liquid (such as alcohol) is injected during injection from an injection port (the structure is approximately the same as that for injecting liquid or gas into the heating barrel described above; it uses porous sintered metal that allows gas and liquid to pass through) equipped with a nozzle at the tip of the heating barrel, and the liquid or gas is dispersed in the resin during injection by the force of the injection and dissolved under pressure, (1) the start of injection is set to zero and a delay time can be set (if it is zero, it will be simultaneous with the start of injection). (2) To stop it, a command to stop injection is set with the screw position. (3) Of course, if injection is stopped once during injection and then started again, the stop and re-injection are done by setting the screw position (which can be set arbitrarily). In addition to providing the nozzle with liquid and gas inlets, similar liquid and gas inlets are provided on the hot runner, which are similarly controlled by the injection molding machine program.

[0236] In the case of the mixed process, where foaming is imparted using gas, liquid, or solid, and foaming resin and non-foaming resin are mixed in the nozzle at the injection stage, the control is the same as the control for injecting liquid and gas from the nozzle described above. Of course, this mixed process can also be implemented with a hot runner.

[0237] (Control of GCP device by injection molding machine sequencer) In the case of GCP, the injection molding machine issues commands to the GCP device as follows: (1) When the mold is closed and (2) it is confirmed that the nozzle touch is complete, (3) the injection valve 46 in Figures 15 and 16 is opened to pressurize the mold with gas (air pressure process). (4) The GCP time is preset, and when the timer times out, the cavity starts to be filled with foamable resin (injection process). (5) When a pressure gauge 56 is used instead of a timer, the cavity starts to be filled with foamable resin when the preset pressure is reached. (6) The GCP is exhausted during injection or after the completion of injection (exhaust process). During injection, the screw position at the start of injection is set as the starting position, and when the screw passes an arbitrarily set position, the exhaust valve 51 in Figures 15 and 16 is opened to release the gas in the mold into the atmosphere (exhaust process). (7) In the case of simultaneous exhaust after the completion of injection or delayed exhaust, a delay time can be set (zero means simultaneous with the completion of injection). In the case of a means of lowering (retracting) the screw to a preset position a certain time after the completion of injection to reduce the pressure of the foamable resin filled in the cavity and make it easier to foam, (8) as described above, in addition to exhausting during injection, simultaneously with the completion of injection, and after a certain time has elapsed after the completion of injection, in the case of delayed suck back during the suck back, a delay time can be set {zero means simultaneous with the completion of retraction (when retracted to the set position)}.

[0238] This is a method of expanding a part of the mold (breathing, expanding core, extended core) to reduce the pressure of the foamable resin filled in the cavity and make it easier to foam, and the timing of breathing can be (1) simultaneously with the completion of filling the cavity with resin, or by setting a delay time (if it is zero, it will occur simultaneously with the completion of injection) (exhaust process). Breathing can be performed by the operation of hydraulic or pneumatic cylinders or motors installed in the mold, or by using the ejector mechanism of the injection molding machine, and in both cases commands are issued from the injection molding machine program. Breathing and suck back are different operations, but can also be performed simultaneously.

[0239] (Core back and molded back) First, the difference between core-back and mold-back will be explained using Figures 17, 18, 19, and 20. (Figure 53 (before core-back) and Figure 54 (after core-back) also show the mold structure of the core-back.) The core-back mold has a parting structure (vertical parting) in which the movable mold 61 is inserted into the fixed mold 59, as shown by the parting number 60 in the figure (Fig. 17). In this state, the cavity 21 formed by the reference numbers 59 and 61 is filled with foamable resin, and if the GCP is implemented, after exhaust is completed, the GCP is moved back (1) by setting the delay time (if it is zero, it will be simultaneous with exhaust completion), as shown in Figure 18, the reference number 61 is moved back (core back indicated by the arrow of the reference number 63), 21 is expanded, and a gap 67 is formed in the parting 60. Since the mold's 59 and 61 form a vertical parting 62, the molten resin does not overflow to the outside. The mold back will be explained using Figures 19 and 20. In Figures 17 and 18, the parting 60 is a vertical parting 62, but in Figures 19 and 20, the parting 60 is a horizontal parting 64. After filling 21 with foamable resin, the movable mold 61 is moved back (mold back indicated by an arrow at reference number 65) to expand 21. The parting 60 and the horizontal parting 64 open as indicated by reference number 66 by the amount of the move back, and the force pressing down on the resin in 21 disappears, but if the gap caused by the move back is small and a skin layer is formed on the surface using GCP, cooling and solidification proceeds and a solidified layer is formed on the surface, so the molten resin inside does not leak out.

[0240] In the case of implementing GCP, after exhaust of compressed air is completed, (1) a delay time is set (if it is zero, it will be simultaneous with exhaust completion). As shown in FIG. 20, reference number 61 is retreated (reference number 65), 21 is expanded, and a gap 66 is created in parting 60. The reason why the molten resin does not overflow to the outside has been described above. Regarding core back and mold back, if a core back shape is provided in the parting, the mold structure becomes complicated and there is a concern that the mold cost will increase (become expensive), so for parting, the mold back structure shown in Figures 19 and 20 is better. In the case of holes, etc., if a mold back (horizontal parting) is used, there is a concern that a gap will be created when molded back and resin will get in, so in this case a core back (vertical parting) structure is used. Both core back and mold back can be easily performed if the program for these operations is previously installed in the internal control panel of the injection molding machine. Direct pressure injection molding machines have a certain degree of accuracy in retracting the mold, but in the case of a toggle mechanism, the retraction accuracy is lower than that of direct pressure, and in some cases puller bolts, etc. are installed in the mold to improve the retraction accuracy (the accuracy of the retraction distance of the core back and mold back). The above-mentioned (1) program for imparting foaming properties to the molten resin in the heater barrel using a gas, liquid, or solid foaming agent, either alone or in combination, (2) programs for retracting the screw and breathing, etc., in order to reduce the pressure of the foamable molten resin filled in the cavity, and (3) programs for injecting and venting compressed air when performing GCP, as well as core-back and mold-back programs, can be easily implemented by installing them in the injection molding machine in advance. Of course, for example, it is easier, safer, and less expensive to build these programs into the control panel of the injection molding machine than to create a separate controller with a built-in sequencer for the GCP device to receive signals from the injection molding machine or send signals to the injection molding machine and interface with each other.

[0241] (Mold back, core back) In the case of mold backs, the molded product will temporarily separate from the fixed side (cavity) of the costume. After that, it will stick to the fixed side again due to the foaming force, and the mold will be transferred. However, the pressure of the mold transfer by foaming force is low, so the mold reproducibility (transferability to the mold) may be low. The means to solve this problem are explained below.

[0242] (Means to control timing of L1, L2, L3 exhaust) In the GCP, L1 (space at the bottom of the movable insert or the ejector box space), L2 (molding space), and L3 (space at the bottom of the fixed insert) are not exhausted simultaneously, but with a time lag, and mold back is performed while applying pressure from the movable side with the pressure of the GCP. In reality, L3 is first exhausted before the foamable resin is filled into the cavity (L2), either at the time of filling or after a certain amount of time has passed since filling. Next, L2 is exhausted at the same time as L3 is exhausted, or with a slight delay. When mold back is performed while L1 is under pressure (the molded product is compressed from the movable side to the fixed side by the pressure of the compressed air), the pressure of L1 is exhausted all at once from parting number 60, etc., because a gap is created by opening the mold. At this time, mold back is performed while being pressed (transferred) by the pressure of L1 as described above, so mold transferability is maintained. The mold structure used is the ejector box structure shown in Figure 10, which exhausts the compressed air in the large-volume ejector box (L1) all at once, making a very loud noise and is not very suitable for mass production. The mold structure shown in Figure 11, which seals the ejector pin, exhausts a relatively small amount of compressed air, so it can be safely carried out. The pressures of L1, L2, and L3 can be the same (L1 = L2 = L3), but if L1 is made a little higher, such as L1 > L2 = L3, the effect of attaching the movable to fixed part will be greater. In this case, the GCP device is a multi-stage exhaust GCP device {three devices shown in Figure 15 that exhaust L1, L2, and L3 separately, and each is connected to L1, L2, and L3 separately. One 43 compressor is sufficient, but if the pressures of L1, L2, and L3 are changed, a regulator (not shown) is provided before the reference number 46. The device shown in Figure 16 is more suitable for the mold structures shown in Figures 11 and 14. Of course, if a regulator is installed, the pressure of L1, L2, and L3 can be changed.} is used. (Figure 38)

[0243] (A separate means of pressurizing the moving side with gas) Figures 31 to 35 show a means for using a seal-type mold with an ejector pin as shown in Figure 11, with gas pressure circuits 90, 92, and 94 provided separately from the movable side (gas is injected into the gap between the resin and the mold on the movable side of the cavity, and pressure is applied from the movable side to the fixed side by the force of a gas separate from the compressed air), and gas pressure pins 89, 91, and 93. L3 and L2 are exhausted, and compressed gas is introduced from a separate circuit, and the pressure of the gas is used to press the movable side to the fixed side, causing mold backing, etc., and increasing the foaming ratio. Numbers 89, 91, and 93 are gas pins for pressurizing from the movable side to the fixed side. In this method, the gas outlet is surrounded by ribs to prevent the gas put into the gap from escaping. (Reference number 101 in Figure 35) It is better for the height of this rib to be higher than the distance required for mold backing. If mold backing is performed while pressurizing gas from the movable side to the fixed side without exhausting the pressurized gas, the pressurized gas in the resin will start to solidify in the cavity, and the gap between the resin and the mold will open up the distance of the mold back, allowing the gas to be released into the atmosphere. The foamable resin is filled into the cavity (L2) under pressurized air of L1, L2, and L3, and L3 is vented during or after filling, and L2 is vented at the same time or with a slight delay. After filling of the foamable resin into the cavity is completed, gas is ejected from reference number 100, and the gas is pumped into the gap between the resin and the mold in the same manner as above to apply pressure. The initial compressed air (L1, L2, L3) uses multi-stage exhaust, which separately vents L3, vents L2, and finally vents L1.

[0244] (A separate means of pressurizing the moving side with gas) 31 to 35 show a seal-type mold for the ejector pin shown in FIG. 11, in which the ejector pin has a double structure (reference number 91), an ejector plate is provided, and a gas circuit (reference number 92) for the ejector plate is provided, and there is a means for applying gas pressure from the gap between the inner core and outer cylinder of the double-structure ejector pin (gas is injected into the gap between the resin and the mold on the movable side of the cavity, and pressure is applied from the movable side to the fixed side by the force of another gas). In this case, the structure is also shown in Figure 31. The structure of the pressure pin is the same as in Figures 32 to 35, and only the location of gas pressure on the movable side is different (the difference between reference number 89 and reference number 91). Figure 31 also shows a case where a gas pressure pin is provided on the ejector plate. There is also a method of providing a structure (reference number 107) that suppresses the gas pressure on the movable side mounting plate (reference number 28). In these cases, the exhaust of the GCP (compressed air) may be a single-stage exhaust, but multi-stage exhaust is preferable.

[0245] (Method of pushing with ejector pin) By using an ejector mechanism in the injection molding machine, the mold retracts, but the ejector pin does not retract. By continuing to push the ejector pin, the molded product does not separate from the fixed side during mold back, etc. For these, the exhaust of the GCP can be a single-stage exhaust, but multi-stage exhaust is preferable.

[0246] (Means for pressurizing gas from inside) There are high pressure gas blow molding methods (for example, GasTy-2, Sympress, Asahi Kasei's AGI, etc.) inside the molded product. This method is applied to mold backing for foam molding. If high pressure gas is injected inside the foam resin before exhausting L1, L2, and L3, and the foam resin is inflated by the force of the high pressure gas inside, the foam resin inside the cavity is suppressed from foaming by the internal gas pressure and remains unfoamed. Even if mold backing is performed, it will not separate from the fixed side and movable side, and the foam resin inside the cavity will expand following the mold back. If the high pressure gas injected inside is exhausted into the atmosphere at the same time as mold back is completed, or with a slight time lag, the pressure that was suppressing foaming from the inside is released, and foaming will begin inside. The structure of the gas injection pin can be made hollow by inserting the gas nozzle 100 into the interior of the pin 104 (up to a position about halfway through the plate thickness) in FIG. The exhaust of the GCP (pressure air of L1, L2, L3) is completed before the mold back, etc. In this case, there is no particular restriction on the order of exhausting L1, L2, L3. In general, it is completed before the mold back, etc.

[0247] In the 3D CAD drawings {Fig. 21, Fig. 22} of the product of the embodiment, the parting of the hole 67 is a core-back structure, and the parting indicated by reference number 68 is a mold-back structure, which forms the shape of the hole in order to prevent gaps from being created in the mold even when the mold is retracted. Some partings have a flat cut (reference number 68) only on the movable side, and some partings are engraved on both sides (reference number 69) with a rounded shape on the fixed side in order to create a rounded shape. Fig. 21 shows the fixed side, and Fig. 22 shows the movable side. Reference number 70 indicates the top plate, which is 2 mm thick when the mold is closed. With this mold, core-back (vertical cut) and mold-back (flat cut) are performed with partings opened 0.5 mm and 1 mm, and the foaming ratio (weight reduction rate) and mold reproducibility of each are confirmed.

[0248] (Heat and Cool) In GCP, the thickness of the surface skin layer changes depending on the temperature of the mold surface, in other words, the speed at which the molten resin filled in the cavity cools and solidifies. Naturally, the higher the temperature, the thinner the skin layer will be. Figure 23 shows a method for increasing the mold temperature using superheated (heated) steam generated using a boiler (heat and cool is common, but in this invention, a device using magnetic fluid, electromagnetic induction, high-frequency heating, etc.). Reference number 71 is the heat medium, which uses polyethylene glycol, glycerin, silicon oil, mineral oil, etc. Reference number 72 is the heating section, which contains small particles or powder of magnetic material (such as ferromagnetic iron, stainless steel, nickel, cobalt, etc.). The external reference number 73 is the coil of the IH heater, and when current is passed through it (ON), a high-frequency current is generated, heating the internal magnetic material (reference number 72), and the heat is transferred to the heat medium (reference number 71), so the heat medium is heated. When the current is turned off (OFF), the heating stops, so the temperature can be controlled by turning the current on and off. Reference number 74 is a wing installed in the circuit, to which a magnet (reference number 75) is attached. When the external magnet (reference number 76) is rotated, the magnetic field changes and the inner wing (reference number 74) rotates, circulating the heated heat medium. The flow rate (flow speed) of the heat medium changes depending on the rotation speed, and the heating efficiency can be controlled. The blades can also be rotated using the principle of Arago's disk. Reference number 78 is an arrow showing the flow direction of the heat medium, and reference number 79 is the die insert to be heated. Reference number 81 is the heating device, and reference number 82 is the circulation device. Reference number 83 is the pipe through which the heat medium 71 flows, and is made of steel pipe. Reference number 83 can also be a flexible hose as long as it is heat-resistant enough. Although not shown, a flowmeter, a thermometer, and a pressure gauge are built into Figure 23, allowing for reliable temperature control. Glycerin is recommended as the heat medium because it can be heated to high temperatures, is water-soluble, and is easy to use. Glycerin has the chemical formula C3H8O3, a melting point of 17.8°C, a boiling point of 290°C, and is a liquid, so it has a larger specific heat ratio and a better heat exchange rate than pressurized heated steam in a boiler. Glycerin is less toxic and water-soluble, so it can be easily removed by washing with water compared to fats and oils, and does not worsen the work environment. Ethylene glycol can also be used, but is not recommended due to its toxicity. Reference number 77 is a flow control valve, and reference number 80 is a filter that is arranged so that the magnetic material remains within 81.

[0249] Cooling is possible by running cooling water through a separate circuit in the mold. It is also possible to run gas or use the heat of vaporization of ethanol or the like. These circuits can be installed in the mold by drilling holes with a gun drill or by machining these heating and cooling circuits into the insert and bonding them together using diffusion welding, a heat treatment method, to create a circuit with high thermal efficiency. For diffusion welding, copper powder and nickel powder are used as the welding material. In the case of GCP, the higher the surface temperature of the cavity (L2), the thinner the skin layer on the surface. In addition to heating the mold with a high-temperature heat transfer medium as described above, there is a method (e.g. Asahi Chemical Industry Co., Ltd. BSM) where a coil is provided in the ejector and high-frequency induction is applied to the mold before the foamable resin is filled (just before the mold is closed) to raise the temperature of the mold surface.

[0250] Another method is to provide the mold with an insulating layer to slow down the cooling and solidification. The insulating layer can be Teflon (trade name) coating, ceramic coating, ceramic plasma coating, etc. Other examples include WC (tungsten carbide), TiN (titanium nitride), CrN (chromium nitride), alumina, DLC (diamond-like coating, guillamond-like carbon), etc. These substances have an insulating effect, so the cooling and solidification speed of the foamable resin molten in the cavity is slowed down, resulting in a thinner skin layer on the surface. Using these methods also has the effect of increasing fluidity, as the cooling and solidification speed is slowed down at the foamable resin's own temperature.

[0251] (Plastic paint) The paint used for the purpose of making up (cover marking) on ​​the resin molded product used in the present invention is selected from paints that dry or harden at low temperatures, such as acrylic resins, styrene-modified acrylic resins, and urethane paints, because the thermal deformation (heat resistance) temperature of the material resin is low in the case of thermoplastic resin molded products. Paints with low baking drying temperatures are selected. Also, when the above paints are directly applied to PP molded products, the affinity between the PP molded product and the above paints (coating film) is poor, and sufficient adhesion cannot be obtained (exercised). Therefore, when painting a PP molded product, a primer containing halogenated (chlorinated, brominated) PE, halogenated PP, etc. as the main component, or maleic acid-modified resin (PP, PE) as the main component is applied, and then the above top coat is applied. The primer and top coat paint may be solvent-based or emulsion-based. After applying the primer and completing the touch dry, the product is forced to dry a little, and then painted with the above decorative paint (top coat paint). The above paints can be solvent-based, emulsion-based, or water-based. There are also cases where the paint is a powder-based paint.

[0252] (Pre-treatment for painting) Painting is generally done by air spray painting or electrostatic painting. To obtain a beautiful coating, the paint is diluted with a special thinner to a viscosity suitable for the work. Pre-treatment before painting involves removing dirt, particles, oil, grease, release agents, etc. adhering to the object to be painted, and removing static electricity, etc., to prevent painting defects. Some manufacturers wipe the parts manually with isopropyl alcohol (IPA), then blow with air before painting, and spray paint. Some painting lines perform this pretreatment automatically, showering or immersing the parts in a degreasing solution, rinsing them with water, draining them, and drying them. When sodium bicarbonate is used as the foaming agent, the foaming residue (sodium carbonate) and undecomposed foaming agent (sodium bicarbonate) cannot be completely removed by these pretreatment methods alone, and if the material is painted as is, the foaming residue and other substances will hinder the adhesion of the paint film. These residues cannot be completely removed by rinsing with water alone, but these alkaline substances can be neutralized with acid to make them water-soluble and easily removed by rinsing with water. The inventor solved the adhesion problem by showering or immersing the workpiece in a dilute aqueous solution containing an organic acid such as acetic acid, citric acid, or succinic acid as a pre-painting treatment, and then rinsing with room temperature or warm water. In the case of immersion, the cleaning effect is increased by combining ultrasonic cleaning or bubbling.

[0253] (Core-back mould structure) Figures 53 and 54 show examples where the mold structure is different from that of Figures 17 and 18. Figures 17 and 18 show vertical partings between metal parts. In Figures 53 and 54, the shape of the movable side (reference number 157) penetrates into the molded product, and after the foamable resin is filled, the movable side is retracted to increase the foaming ratio. Reference number 155 indicates the space (molding space) between the movable side mold and the fixed side mold where the resin enters (is filled). Reference number 156 indicates the outer molded product that does not expand when reference number 61 is retracted.

[0254] (Another shape of O-ring used for sealing PL, etc.) The O-ring of No. 33 in Figure 11 is usually circular in cross section, and is vacuumed after mold backing to eliminate raindrops, and since PL needs to be sealed sufficiently even if the parting is opened after mold backing, the O-ring of No. 33 is made thicker. In addition, the V-ring shown in Figure 55 and the U-ring shown in Figure 56 are used. No. 159 and No. 160 are openings, and when gas enters here, the pressure causes it to expand outward, providing a seal. No. 158 shows the cross section of a V-ring, and No. 161 shows the cross section of a U-ring. Figure 57 shows the combination of a V-ring and a normal circular O-ring, and Figure 58 shows the case of a U-ring.

[0255] As mentioned above, the O-rings in Fig. 55 and Fig. 56 have a sealing directionality, so when the molding space is pressurized and then vacuumed after the pressure is exhausted, a V-ring (V seal ring) or U-ring (U seal ring) with openings 159, 160 facing the molding space and a V-ring or U-ring facing in the opposite direction to the PL direction are placed in the molding space to seal the left and right. An O-ring 162 may be placed between them. (Fig. 59, Fig. 60) Fig. 61 and Fig. 62 show a shape in which Fig. 55 is integrated on the left and right, and Fig. 63 shows a shape in which Fig. 56 is integrated on the left and right. In some cases, an O-ring shape with the number 162 is placed in the center. The material of these rings is sufficient, such as NBR or urethane rubber, which is the same as commercially available O-rings. Silicone rubber, fluororubber, etc. can be used as necessary. The hardness of the rubber is changed to the optimum hardness depending on the size of the mold and the pressure of the compressed air. Although not shown, in Figures 55 to 62, the molding space is at the left end of the drawing, and the right end shows the outside through the PL. The PL surface in Figures 55 to 62 is the surface on which the seals in these drawings are arranged (not shown). Reference numeral 163 is a V-seal in Fig. 55 with opening 164 facing outward, and reference numeral 166 is a U-seal in Fig. 55 with opening 165 facing outward. Reference numerals 159, 160, 164, and 166 may be inserted (fitted) with a spring in Fig. 29 or an O-ring in Fig. 30, as in Figs. 24 to 26, to make them open outward (weight-applied or load-loaded).

[0256] (Vacuum device) This section explains how to eliminate raindrops, a problem specific to GCPs, by further evacuating the compressed air inside the mold after exhausting the GCP. In the GCP device shown in Figure 15 or Figure 16, open the exhaust valve no. 51, evacuate the compressed air inside the mold, and then perform mold back and core back. This exhausts the compressed air that gets into the gap between the mold and the resin and causes raindrops (through the exhaust valve no. 51 of the GCP device), reducing raindrops, making them less noticeable, and eliminating them. Raindrops can be reduced by further vacuuming.

[0257] The mold is closed, and the seal mold shown in Figures 10 and 11 is pressurized to fill with foamable resin, and valve 51 is opened during and after filling is complete to exhaust the compressed air. During and after exhaust is complete, the PL of the mold is opened (to allow mold back and core back) to exhaust the compressed air that has entered the gap between the mold and resin and is the cause of raindrops. When performing vacuum drawing, valve 51 is closed, the vacuum drawing device 174 shown in Figure 63 is opened, and the compressed air inside the mold is drawn into the tank 169, thereby reducing the compressed air in the gap between the resin and the mold, and the mold is transferred by the foaming force of the molded product. Raindrops increase when the mold surface temperature is high, the temperature of the molten resin is high, or the compressed air pressure is high, but these problems can be solved by using vacuum pumping. In Fig. 63, reference numeral 177 denotes a vacuum pump, 173 denotes a solenoid valve, which is driven (ON and OFF) by the pressure set on reference numeral 170, a pressure gauge (capable of signal output) that checks the pressure in reference numeral 169 tank. Reference numeral 176 denotes a manifold, 171 denotes a hose, and 172 denotes a one-touch coupler that supports vacuum pumping, which is connected to L2 of the mold (compressed air circuit to the molding space). Reference numeral 168 denotes a check valve, and the arrows at reference numeral 175 indicate the flow of the compressed air pumped by vacuum pumping.

[0258] Next, the present invention will be described based on examples. The resins used in the embodiment will be described. ABS was Clarastic GA-501 (trade name) from Nippon A&L Co., Ltd., PS was Toyo Styrol G100C (trade name) from Toyo Styrene Co., Ltd., HIPS was Toyo Styrol H450 (trade name) from Toyo Styrene Co., Ltd., m (styrene modified)-PPE (polyphenylene ether) was Zylon 100Z (trade name) from Asahi Kasei Co., Ltd., PC / ABS (polymer alloy, blend polymer of PC and ABS) was Multilon T3714 (trade name) from Teijin Chemical Co., Ltd., PC was Iupilon S2000 (trade name) from Mitsubishi Engineering Plastics Co., Ltd., and PP was Noblen AZ864 (trade name) from Sumitomo Chemical Co., Ltd. The molding machine used is an injection molding machine manufactured by Toyo Machinery & Metals Co., Ltd., and the PLC in the molding machine manufactured by Toyo Machinery & Metals Co., Ltd. is equipped with programs that control, command, and instruct the GCP device of the present invention, the liquid injection device, the blow molding device, the compressed air molding device, and the mold temperature regulator shown in Figure 23 of the present invention. EXAMPLES

[0259] (Production of foaming agent master batches) We prepared powdered baking soda as an inorganic foaming agent, powdered organic foaming agents and ADCA, and powdered monosodium dihydrogen citrate (monosodium citrate, monosodium citrate, monosodium citrate) as a foam nucleating agent. We sent the above baking soda, ADCA, monosodium citrate, and ABS, PS, and PP pellets to Towa Chemical Co., Ltd. (6-66-35 Wakae Higashimachi, Higashiosaka City, Osaka Prefecture, 578-0935) and requested H processing, an improved version of MC processing and SC processing (the details of H processing are unknown as they are trade secrets from Towa Chemical, but this is the explanation we received from Towa Chemical), and each foaming agent (baking soda and ADCA) and foam nucleating agent were supported on the surface of each resin pellet. A master batch of ABS blowing agent with 10 wt% sodium bicarbonate supported on ABS (development code: Wn-B-sodium bicarbonate-10), a master batch of PS blowing agent with 10 wt% sodium bicarbonate supported on PS (development code: Wn-S-sodium bicarbonate-10), a master batch of PP blowing agent with 10 wt% sodium bicarbonate supported on PP {AZ864 (block copolymer MI value = about 30) (development code: Wn-P-sodium bicarbonate-10), a master batch of ABS blowing agent with 10 wt% ADCA supported on ABS (development code: Wn-B-ADCA-10), a master batch of PS blowing agent with 10 wt% ADCA supported on PS (development code: Wn-S-ADCA-10), a master batch of PP blowing agent with 10 wt% ADCA supported on PP (AZ864) (development code: Wn-P-sodium bicarbonate-10) We produced a master batch of a foam nucleating agent for ABS with 10 wt% monosodium citrate supported on ABS (development code: Wn-B-CANa-10), a master batch of a foam nucleating agent for PS with 10 wt% monosodium citrate supported on PS (development code: Wn-S-CANa-10), and a master batch of a foam nucleating agent for PP with 10 wt% monosodium citrate supported on PP (development code: Wn-P-CANa-10). In Example 1, H processing was used, but it is also possible to manufacture using the pellet processing of Hexa Chemical Co., Ltd. (Higashi Osaka City). It has been confirmed that the same products (foaming agent master batch, foaming assistant master batch, etc.) can be manufactured using the above-mentioned means, such as a Henschel mixer. This can also be done with Aichi Electric Co., Ltd.'s rocking mixer RHM-(SJ) (product name) and rocking mixer RMDHLV (product name). EXAMPLES

[0260] (Manufacturing foam moldings without GCP) Foam molding was performed using the molds shown in Figures 21 and 22 without GCP, using a foaming agent suitable for each of the above ABS, HIPS, m-PPO(E), PP, PC, and PC / ABS (for example, the above Wn-P-ADCA-10 for PP), and a foam nucleating agent as necessary. Of course, since this was foam molding without GCP, the occurrence of swirl marks on the surface of the molded product was confirmed by visual inspection. The molded product was broken (split) to check the inside, and it was confirmed that foam cells were present and a foam layer was formed. Figures 42 and 43 show the results of each molded product. Figure 42 shows the combination of each molding resin with the master batch of the foaming agent, the amount added, and the amount of foam nucleating agent added. Similar results were obtained when the amount of each foaming agent was 3wt% or 5wt%. When the molding resin is PP, the foaming agent master batch is manufactured by adding acid-modified PP that is compatible with the PP to be molded to pellets of the PP to be molded, so there is no generation of silver (reference number 2) near the gate as shown in Figures 1 and 2. The particle size of the baking soda in the foaming agent for PP, Wn-P-baking soda-10, was finely reduced to 0.5 μm to produce a master batch of the foaming agent, and measures were taken to reduce the amount of foaming gas generated from each particle of baking soda and make the swirl marks less noticeable, but since the GCP described below was not used, swirl marks still occurred on the surface. EXAMPLES

[0261] (Manufacturing foam molded products with GCP) A sealing mold using the ejector box shown in FIG. 10 (also possible in FIG. 11) in the mold structure of Example 2 was connected to one GCP device shown in FIG. 15 at L1 to L3. A 350-ton injection molding machine (Si-350-6S) manufactured by Toyo Machinery & Metals Co., Ltd. was used. The injection molding machine (Si-350-6S) has the GCP program {pressurized air (entering gas) into the mold and exhaust, suck back, breathing, core back, mold back, etc.} described in detail above, which controls the GCP device shown in FIG. 15, built into the molding machine program. Therefore, the device shown in FIG. 15 is operated by the program installed in the program of the injection molding machine without using a separate controller. The weight of the product of the mold in Figure 13 is about 100 grams per piece (about 200 grams for both). After the injection molding machine confirmed that the mold was closed and touching the nozzle, the injection molding machine sent a signal to open the injection valve 46, and compressed air was sent from the injection valve 46 to the spaces L1 to L3 of the mold. The output signal of the pressure gauge 56 was set to 0.8 MPa, and when the pressure gauge reached this value (presumably the same pressure in the mold), the injection molding machine received this signal and opened the pneumatic shut-off nozzle, filling the cavity (L2 space) with the foamable resin in the heating barrel. When the filling rate (vol%), defined as the volume of the molten resin filled in the cavity divided by the volume in the cavity x 100, reached 95 vol%, the injection molding machine opened the exhaust valve 51 and exhausted the gas in the molds L1 to L3. The external appearance and the internal foam layer are shown in Figure 44. When the molding resin is PP, the base resin of the foaming agent master batch is a compatible PP, and the PP used to support the foaming agent is also an acid-modified PP (for example, maleic acid) that is compatible with the PP of the molding material, so there is no silver generation near the gate as shown by reference number 2 in Figures 1 and 2. EXAMPLES

[0262] (Difference in timing of exhausting compressed air inside the mold) In Example 3, the exhaust time was (1) immediately after 100% filling of the cavity and 3 seconds after filling, but the appearance and the internal foam layer did not change, and the delayed timing of exhaust did not seem to have a significant effect. On the other hand, when the exhaust timing was set at a filling rate of 60% (midway through filling), the foaming force (foaming force of the foaming gas, foaming force) could not be suppressed at the end of the flow, and swirl marks occurred at the end of the flow. If the exhaust is started when the molding space is filled with 90% or more of the foamable resin to which foaming properties have been imparted, no swirl marks will be observed even at the end of the flow. EXAMPLES

[0263] (GCP compressed air pressure) In Example 3, the pressure of the compressed air (pressure in the molding space) of the GCP was changed from 0.8 MPa to 1.0 MPa, 1.2 MPa, and 1.4 MPa. There was no change in the appearance and foam layer due to the difference in the compressed air pressure. When the compressed air pressure was lowered to 0.6 MPa, the foaming power could not be suppressed, and swirl marks occurred throughout. In particular, when ADCA was used as the foaming agent, swirl marks occurred frequently. This is presumably due to the low solubility of nitrogen gas, which is a foaming gas, in the resin used. The pressure of the compressed air into the molding space of the GCP changes depending on the type of foaming agent, the amount of foaming agent added, and the type of resin. Naturally, if the compressed air pressure is high, swirl marks can be eliminated even if there is a lot of foaming agent with high foaming power (for example, ADCA). EXAMPLES

[0264] (Painting suitability for molded products without GCP) Paints suitable for the molded products obtained in Example 2 {the numbers (reference numbers) of the molded products are shown in FIG. 43} were used. For the ABS, HIPS, m-PPO(E), PC, and PC / ABS molded products, a paint mainly composed of styrene-modified acrylic resin {Repelle S#1100 (product name, product number) manufactured by Tohpe Corp.} was used. For the PP molded products, a primer was required, so they were first primed with Multiprimer EXC-3000 (product name, product number) manufactured by Musashi Paint Co., Ltd., and then topcoat paint was applied using EC-GPX79-Eco High Urex {color: silver (mixing ratio of base agent to hardener: 10:1) (product name, product number)} manufactured by Musashi Paint Co., Ltd., to obtain painted molded products. The painted surfaces of these molded products were subjected to a cross-cut test in accordance with JIS K-5600-5-6. The results are shown in Figure 45. All of the molded products in Figure 45 had swirl marks, but the swirl marks were merely a thin resin film on the surface of the molded product, and there was almost no adhesion between the swirl marks and the main body of the molded product, so the swirl marks were the cause of the peeling.

[0265] The detailed method of the coating method in Example 6 is as follows: for the molded products of ABS, HIPS, m-PPO(E), PC, and PC / ABS, (1) the surface was degreased using isopropyl alcohol (IPA), (2) the product was left indoors to evaporate the IPA, and (3) the above-mentioned paint suitable for the material of each molded product was spray-coated. The film thickness was about 10 μm. (4) After setting for about 3 minutes, (5) the drying temperature was 50 to 60°C and the drying time was 45 minutes. (6) After leaving the product indoors for 48 hours, the above-mentioned adhesion test was performed and the results were obtained. For the molded products of PP, (1) the surface was degreased using IPA, (2) the product was left indoors to evaporate the IPA, and (3) a primer treatment mainly composed of chlorinated polyolefin resin was required, so Multi Primer EXC-3000 was sprayed first, and after setting for 5 minutes, the product was dried at 60°C for 30 minutes, and the film thickness was 3 μm. (4) A suitable paint (EC-GPX79-Eco Highurec, silver color) was spray painted. The film thickness was about 10 μm. (5) After setting for 5 minutes, (6) the film was dried at 60°C for 45 minutes. The film thickness was 15 μm. After leaving the product indoors for 48 hours, the above adhesion test was carried out in accordance with JIS K-5600-5-6. The results are shown in Figure 45. When painting PP foam molded products, first apply a primer made of maleic acid-modified PP to the PP, then paint using a two-component urethane paint, etc. In this case, it is preferable to use a primer made of the same material as the maleic acid-modified PP foaming agent master batch (such as Hardlen NZ-1015). Of course, different materials can be used, but in that case, the adhesion of the primer to the foam molded product containing maleic acid-modified PP must be confirmed. If it is maleic acid-modified PP, it can be used even if the modification rate is different (for example, Toyobo's Hardlen NZ-1015 can be used to manufacture the foaming agent master batch, and Arrowbase DA-1010 can be used as a paint primer). EXAMPLES

[0266] (Painting suitability for molded products with GCP) In Example 7, the molded product used in Example 6 was subjected to GCP and a molded product with a smooth surface and no swirl marks {the molded product number (reference number) is shown in Figure 44} was used to obtain a painted molded product using the same paint and method as in Example 6. As in Example 6, a cross-cut test was performed in accordance with JIS K-5600-5-6 to check the primary adhesion, and the adhesion of the paint film on all molded products was good at 100 / 100 (Figure 44).

[0267] In order to confirm the secondary adhesion, a salt spray test (SST) was conducted for 240 hours based on JIS K5600-7-1. No peeling of the coating was observed in the case of the foaming agent using ADCA, but blistering of the coating was observed in the case of the foaming agent using sodium bicarbonate. (Figure 47) This was presumed to be caused by the fact that either the sodium bicarbonate foaming residue left after the foaming agent sodium bicarbonate thermally decomposes to generate foaming gas carbon dioxide and water vapor, or undecomposed sodium bicarbonate, or both, remained attached to the molded product surface (only degreasing with IPA). Blisters of the coating were also observed in the water resistance test of JIS K5600-7-2, for example, left at 50°C and 98% RH (humidity) for 240 hours, and in the water resistance test of JIS K5600-6-2, for example, immersed in 40°C warm water for 240 hours. (Figure 47) EXAMPLES

[0268] (Removal of foam residue) Since it was suspected that the cause of the blistering in Example 7 was sodium carbonate and undecomposed sodium bicarbonate, only the molded products that used sodium bicarbonate as a foaming agent were degreased with IPA and then immersed in a 1 wt% acetic acid solution for 10 minutes to make the sodium carbonate and undecomposed sodium bicarbonate water-soluble {acetic acid is acidic, so it is neutralized (reacted) and becomes easily water-soluble}, washed with water, and then dried. The acid-washed molded products were subjected to the SST for 240 hours as in Example 7, and then subjected to a water resistance test and a salt water immersion test. No blistering of the coating occurred (Figure 47). The results were similar when a 5 wt% citric acid solution was used instead of acetic acid, and the improvement in the adhesion of the coating was confirmed. From the results of Example 8, it was confirmed that when sodium bicarbonate is used as a foaming agent, the adhesion of the coating can be improved by performing acid washing. Although sodium bicarbonate was used in Example 8, similar results were obtained with potassium bicarbonate. EXAMPLES

[0269] The mold in Example 2 was as shown in FIG. 13. In Example 9, the mold in FIG. 14 (details in FIG. 12) was used, in which the ejector pin was sealed using the load-type O-ring, U-shaped packing, V-shaped packing, L-shaped packing, etc. in FIG. 24, FIG. 25, FIG. 26, FIG. 27, and FIG. 28, and GCP was performed in the same manner as in Example 2. No swirl marks were generated for any resin. However, when the filling speed was set to the fastest and the highest pressure, the gas {gas (compressed air)} escape (gas transfer, gas release, etc.) of the GCP was insufficient due to the rapid pressure rise, and short mold, discoloration, and burning occurred. As a result of changing the GCP device to the GCP device in FIG. 16 with the 55 sub-tank, the gas in the GCP was returned (transferred) to the sub-tank 55 by the force of filling, even when molten resin was filled at high speed and high pressure, so the short mold, discoloration, and burning caused by the rapid pressure rise did not occur. The GCP device has a 55 sub-tank, which is more effective in preventing discoloration and burning, as the compressed air pressure in the molding space is compressed by filling the resin. In the case of Figure 11, the ejector box L1 plays the role of this 55 sub-tank. EXAMPLES

[0270] (Molded back and core back) In Example 2, immediately after exhausting the compressed air (after the GCP process is completed), the mold is moved back by 0.5 mm {the movable mold is lowered by 0.5 mm in the injection molding machine to perform mold back and core back}, and the weight is reduced by 25% by the expansion ratio = 100-0.5 mm {movable mold back distance, mold opening distance + 2 mm (initial top plate thickness)} ÷ 2 mm (initial top plate thickness) × 100 = 25%. Immediately after exhausting the GCP, the mold is moved back by 1 mm to obtain a foamed molded product with an expansion ratio of 50%. Both the 0.5 mm and 1 mm ones are subjected to GCP, so there is no swirl mark on the surface of each resin. There is no sink or bulge caused by mold back and core back, and the mold reproducibility is high and there is no shape distortion. Only in the hole portion of No. 67 (the core-back structure portion) did the cooling of the hole proceed first, or did the surrounding area appear to be a little difficult to foam. No. 67 is a mold structure with vertical edges, but it can also be implemented with a mold back with horizontal edges. EXAMPLES

[0271] In Example 9, the mold in Fig. 14 was used, and the GCP device in Fig. 16 was used to make mold backs and core backs (holes numbered 67) of 0.5 mm and 1 mm in the same way. Even in foam-molded products with an increased expansion ratio, there was no generation of swirl marks, sink marks, or bulges, and the mold reproducibility was high with almost no shape distortion. It was confirmed that if the timing of the retreat is delayed to 5 seconds or 10 seconds after the compressed air of the GCP process is exhausted, the cooling and solidification of the molded product in the cavity naturally progresses, and the mold repeatability of mold back and core back decreases. The delay time varies depending on the type of resin, type of foaming agent, amount of foaming agent added, type of foaming gas, GCP pressure, thickness of molded product, etc., but from the inventor's experience, a delay of more than 10 seconds is not necessary to cause swirl marks.

[0272] Even if the air is vented when the molding space is filled with 90% or more of the foaming resin, it takes some time for the air to be vented completely, and there is a slight delay in the time it takes for the foaming gas inside the resin to come to the surface and cause swirl marks, so it is possible to obtain a beautiful molded product without swirl marks on the surface. In this way, the exhaust is adjusted (set) within a range of filling the molding space to 90% or more, filling it completely, or delaying it by about 10 seconds while checking the appearance of the molded product. The timing of exhausting L1, L2, and L3 may be set simultaneously or within the range of the delay time during the molding process. In the case of simultaneous exhaust, one of the GCP devices in Figures 15 and 16 may be used. Several devices (for example, three) may also be used. In principle, exhaust is performed all at once to cause foaming, but a flow rate adjustment valve may be provided on the exhaust valve to control the exhaust speed. It is also possible to perform vacuum drawing after exhaust by adding a weighted O-ring 42 in Figure 11 with the direction reversed {The O-ring 42 (weighted O-ring in Figure 24) has a directional seal, so an additional one (not shown in Figure 12) is required for vacuum drawing.}

[0273] When the mold is returned immediately after exhausting the GCP or after a short delay, the raindrop phenomenon caused by the resin filling can be solved in the case of foam molding using GCP. The mold is returned, the gas vent is opened, and the pressure that causes raindrops is rapidly exhausted, and the mold is reproduced because the foaming force of the internal foam layer presses the mold against the mold before cooling and solidifying is complete. In this case, raindrops do not occur even on thin (shallow) grain or glossy surfaces. EXAMPLES

[0274] (Mold temperature control) In Example 3, the surface temperature of the mold was set to about 45°C for both the fixed side and the movable side for ABS, HIPS, m-PPO(E), and PP, and 55°C for PC. In Example 12, the device shown in Figure 23 was used, and glycerin was used as the heat medium, and both the fixed side and the movable side were set to 150°C. GCP was performed, and then cooling water was circulated in a separate circuit provided in the mold to produce a foam-molded product. As a result of setting the mold temperature high at 85°C, even with a top wall of 2 mm, the surface skin layer was very thin and the internal foam layer was sufficiently foamed. The results were the same in Example 9. In Examples 10 and 11, mold-back and core-back were used, and the mold reproducibility of the hole (reference number 67) was low, but in Example 12, the surface skin layer became very thin, so the mold reproducibility of the hole (reference number 67) was also sufficiently high. In Examples 10 and 11, the mold was retreated by 2 mm, and even if the foaming ratio was 100%, cooling and solidification were slow, so the mold reproducibility was sufficient and a molded product with good appearance was obtained.

[0275] GCPs act to suppress the foaming power of the foamable resin filled in the cavity, but the gas in the cavity is a nuisance that hinders the filling of the molten resin into the cavity. Therefore, in the case of foam molding using GCPs, the higher the GCP pressure, the higher the mold temperature (raindrops are more likely to occur with styrene-based resins with high melt viscosity, such as PP, which has a lower melt viscosity than ABS), and the higher the molten resin temperature, the more appearance defects called raindrops (the phenomenon in which small dents are created on the surface of the molded product when rainwater falls on a puddle) occur {the appearance of dents on the surface of the molded product}. To eliminate this appearance defect, it is necessary to lower the pressure of the compressed air in the GCP, the mold temperature, and the resin temperature, but this does not result in the desired foam molded product. An effective way to solve this problem is to apply texture processing to the fixed decorative surface. There is no problem with applying it to the movable side. The action and effect of texture is that when you try to apply cooking wrap (thin film) to a glossy glass surface, bubbles will get in. However, in the case of ground glass, bubbles do not form and it can be applied neatly. If the surface is rough, air bubbles are even less likely to form. If the surface is rough, a beautiful appearance without raindrops can be obtained even with foam molding using GCP. Besides embossing, the problem of raindrops can also be solved by using mold backs and core backs. To eliminate raindrops, the amount of mold back or core back needed is only 0.1mm, and because this method does not increase the foaming ratio, there is almost no decrease in the strength of the molded product. Mold backs with horizontal cuts in the PL of the mold are more suitable as a means of eliminating raindrops than core backs with vertical cuts, because the pressure that gets in between the resin and the mold, which causes raindrops, can be quickly exhausted. The molded product fixed side in Figures 21 and 22 was processed with a 50μm deep sand grain, a 20μm deep sand grain, and a 5μm deep matte grain. PP was used, the GCP pressure was 1MPa, and the foaming agent was 3% Wn-P-ADCA-10 and 1% Wn-P-CANa-10. In the case of 50μm, the grain is deep, so raindrops do not occur, but in the case of 20μm, raindrops do occur. As a result of performing 0.1mm mold back, raindrops did not occur on the 20μm grain surface and, of course, on the 5μm grain surface. As a result, it is judged that mold back is a very effective means of solving the problem of raindrops by mold back. 10wt% calcium carbonate was added to PP to create a composite material, and 0.1mm mold back was performed in the same manner as above. As a result, raindrops did not occur even in fine grains with a grain depth of 5μm or less. From the results of Example 12 above, it can be seen that if shallow embossing is performed and mold back is performed, the problem of raindrop caused by the pressure air trapped in the gap between the resin and the mold due to the resin filling is not released can be solved. The problem of raindrop can be sufficiently solved by adding inorganic substances such as calcium carbonate, glass fiber, and glass beads to the resin, but the amount of additives can be reduced by performing mold back.

[0276] (Method to eliminate raindrops on glossy surfaces) In the GCP device shown in Figures 15 and 16, the compressed air in the mold is exhausted by receiving an exhaust signal from the molding machine or the like, and opening the exhaust valve with reference number 51, and exhausting the air with the pressure of the compressed air (natural exhaust, atmospheric exhaust). However, as shown in Figure 49, a vacuum circuit (circuit with reference number 141, etc.) may be provided separately from the exhaust valve 51, and the vacuum may be drawn after the exhaust. In this case, in order to fully achieve the effect of the vacuum, the exhaust valve 51 is opened first, and the mold is opened as necessary after the exhaust is completed. The opening amount is the distance that expands the mold (mold back, core back, recess, recess) to expand the molding space for the purpose of increasing the foaming ratio, or the method of eliminating raindrop by opening it a little, for example, 0.1 mm or 0.3 mm, to expand the gas vent, as described above. In this case, the PL structure may be vertical (PL has a core back structure), but horizontal opening (PL has a mold back structure) is more effective for exhausting the compressed gas between the mold surface and the molded product that is caught by the resin when it is filled. After evacuating as necessary, close 51, open 141, and pull into the vacuumed (reduced pressure) tank in 142. In this case, the O-ring at parting 33 should have a crushed allowance of more than the distance required for mold backing in order to maintain its sealing function even when the mold is open. The load type O-ring 42 used for ejector pins, etc. has a directional property, so when performing vacuuming, install it in a different direction (opposite direction) from 42 to enhance the effect of vacuuming. The vacuuming device is shown in Figure 63.

[0277] The compressed gas is air, nitrogen gas, carbon dioxide gas, and a 1:1 mixture of nitrogen gas and carbon dioxide gas, each of which is compressed at a pressure of 1.4 MPa into the sealed mold. In Example 12, the compressed gas is exhausted using the GCP device shown in Figure 49, and after the mold is backed up by 0.2 mm, a vacuum is drawn, and it was confirmed that raindrops are reduced, almost to the point where they are no longer visible. The depth of the grain in the case of GCP is 0.5 μm, but it was confirmed that it is possible to achieve this on a glossy surface. When the compressed air pressure is high, the force that holds down the foam cells in the GCP is high, and the effect of reducing foam stripes is great. The vacuum device is controlled by a program built into the PLC of the molding machine. Alternatively, a separate PLC may be installed to exchange signals with the molding machine and control the vacuum device.

[0278] Here are some concrete steps to eliminate raindrops on glossy surfaces when using GCP. First, a higher mold temperature can make the non-foamed layer (skin layer) on the surface of the foam molded product thinner. Specifically, for non-crystalline materials such as ABS and HIPS, the temperature of the mold is raised by a commercially available heat and cool device, a device like that shown in Figure 23, or a method of raising the mold surface temperature by generating eddy currents on the mold surface by attaching a high-frequency induction coil to the ejector {for example, Asahi Chemical Industry's BSM molding method}. This method can be used for PC with PP and modified PPO(E), etc. When the mold temperature is high, the skin layer can be made thinner as mentioned above, but the occurrence of raindrops is more frequent than when the mold temperature is low. It has been said that good results can be obtained by applying embossing and mold-backing the mold to eliminate raindrops. If a vacuum is applied all at once after mold-backing, the pressurized gas that has entered the gap between the mold and the resin can be sucked out all at once, and the pressurized gas in the gap between the resin and the mold can be eliminated, so that a foam molded product that has been subjected to GCP can be obtained with a beautiful appearance without raindrops even on finely embossed or glossy surfaces. EXAMPLES

[0279] Clalastic GA-110G-10 (product name) manufactured by Nippon A&L Co., Ltd. was prepared as an ABS containing 10 wt% glass fiber, and Clalastic GA-110G-20 (product name) manufactured by Nippon A&L Co., Ltd. was prepared as an ABS containing 20 wt% glass fiber. The materials containing 10wt% and 20wt% glass fiber were molded not by foam molding but by normal solid molding as in Example 12 (using the equipment in Figure 23, the surface temperature of the mold was set to 150°C, which is above 125°C, in the case of ABS, which is a non-crystalline resin and does not have a glass transition temperature (T9), but is instead set based on the Vicat softening point temperature, heat distortion temperature (HDT), deflection temperature under load, etc.) without GCP. As a result, there were no weld lines caused by the hole indicated by reference number 67, and no floating glass fibers, and a molded product with a very beautiful, glossy appearance was obtained. In this case, no embossing was performed on the decorative surface fixing side.

[0280] When Wn-B-ADCA-10 was used as the foaming agent and added to the above resins GA-110G-10 and GA-110G-20 at a ratio of 4 wt%, and the GCP pressure was set to 1.4 MPa, the glass fibers sank and the molded product was glossy, resulting in raindrops. As a result of sand embossing with a grain depth of 50 μm and 15 μm, there was no raindrop caused by GCP (due to high pressure and large amount of gas), the glass fibers sank, and a clean and thin skin layer was formed on the outside, and inside the glass fibers acted as a foam nucleating agent, forming a foam layer with fine foam cells. EXAMPLES

[0281] In Example 13, the molding material and foaming agent master batch shown in Figure 42, and a foam nucleating agent were used as necessary, and the surface temperature of the mold was set to, for example, 150°C, which is higher than T9 of each resin, and a 50μm embossing was performed on the mold shown in Figure 14. Using the GCP device shown in Figure 16, the mold back and core back were made 2mm. Since the mold temperature was high, there were no appearance defects such as raindrops even at a foaming ratio of 100%, and the mold reproducibility was higher than when the mold temperature was low, and the skin layer was very thin, but there were no swirl marks on the surface. EXAMPLES

[0282] (A method of suppressing one side by creating a time difference in exhaust) In Example 3, three GCP devices shown in Figure 15 were used to connect L1 to L3 of the compressed air circuit, and the pressure of L1 to L3 was set to 1.3 MPa. When the cavity was filled with 95 vol% foamable resin, L3 was evacuated, and when it was filled with 100 vol%, L2 was evacuated, and a 2 mm mold back was performed. After the mold back was completed, L1 was evacuated. Naturally, the parting of the mold opens, so the exhaust of L1 begins at that time. As a result of the observation, L1 was delayed, so there was a push against the fixed side, and the mold transfer was sufficient. After evacuating L2, we confirmed that the mold back 2 mm also had the effect of pressing down on the fixed side. We confirmed the effect of pressing the mold back at distances of 0.1mm, 0.2mm, 0.5mm, and 1mm. We also confirmed that the raindrop phenomenon was resolved at each mold back distance. EXAMPLES

[0283] In Example 3, three GCP devices shown in Figure 16 were used and connected to L1 to L3 of the compressed air circuit, as shown in Figure 38. The pressure of L2 of L3 was set to 1.0 MPa, and L1 to 1.4 MPa. When the cavity was filled with 95 vol% foamable resin, L3 was evacuated, and when it was filled to 100 vol%, L2 was evacuated and a 2 mm mold back was performed, and after the mold back was completed, L1 was evacuated. Naturally, the parting of the mold opens, so the exhaust of L1 begins at that time. As a result of the observation, L1 was delayed, so there was a push against the fixed side and the mold transfer was sufficient. As in Example 15, it was confirmed that even if L2 was molded back after evacuation, the mold transferability was sufficient and the raindrop problem could also be solved. EXAMPLES

[0284] (Production of foaming agent master batch) PC is dissolved in chlorinated organic solvents such as carbon tetrachloride, chloroform, and methylene chloride, ester-based organic solvents such as ethyl acetate and butyl acetate, aromatic hydrocarbons such as benzene, toluene, and xylene, ketones such as acetone, and other solvents such as dimethylformamide (DMF) and diacetone alcohol. PC pellets are dissolved in these solvents (mixed solvents of two or more types are also acceptable) to produce varnish. PC pellets are mixed with a foaming agent such as ADCA (powder-like properties) in a rocking mixer, and the varnish is added (the varnish can be sprayed while mixing and heating in a rocking mixer to evaporate the solvent), and the solvent in the varnish is evaporated and evaporated to dryness, resulting in the foaming agent ADCA being supported around the PC pellets.

[0285] Below is a simple manual manufacturing method for a PC foaming agent. First, 400 milliliters (ml) of ethyl acetate was added to 100 grams of pellets of PC resin (Lexan 141 (trade name)), and after leaving it at room temperature for 24 hours, it was heated to 45 degrees (℃) and stirred to dissolve the PC in the ethyl acetate, obtaining a PC varnish. In a Teflon-coated frying pan, mix 500 grams of the Lexan 141 pellets and 50 grams of ADCA powder, then add the PC varnish little by little while stirring with a spatula, to support the ADCA around the PC pellets. The frying pan was slightly heated to about 40°C to 60°C to hasten the evaporation of the solvent, ethyl acetate. In this way, the ethyl acetate was evaporated to dryness to support the ADCA on the PC, but if the pellets are stuck together, they can be crushed with a wooden hammer. In this way, a master batch of PC foaming agent (PC001) was obtained.

[0286] The Lexan 141 pellets were mixed in a tumbler at a ratio of 40:1 with PC001 (1 / 45 x 0.01 = 0.025 wt% added as ADCA), and foam molding was carried out in a 350-ton injection molding machine. As GCP had not been carried out, swirl marks occurred on the surface, but a foam structure with discontinuous foam cells was obtained inside.

[0287] In the foam molding, the GCP device of the present invention (Figures 9, 15, 16, 38, etc.) was used to fill the seal mold shown in Figures 10 to 14, which was previously pressurized with air at a pressure of 1.4 MPa, with foamable resin to which foaming property had been imparted using the foaming agent PC001, to obtain a foam structure having a clean skin layer on the surface and fine foam cells inside.

[0288] In the case of ADCA, it decomposes thermally to generate foaming gases such as nitrogen gas, carbon monoxide, and carbon dioxide, but also produces a small amount of ammonia gas. Ammonia gas is alkaline and may decompose PC, so a small amount of organic acid such as citric acid is added to react with the ammonia and make it harmless. These organic acids are also in powder form, so they can be supported around the PC pellets in the same way as PCoO1, to create a citric acid master batch. ADCA generates nitrogen gas, which has low solubility in resin, so the size of the foam cells becomes large. Zinc oxide, calcium carbonate, calcium sulfate, barium sulfate, and other foam nucleating agents are also in powder form, so they are similarly supported on PC pellets to produce master batches of foam nucleating agents for use. These can be mixed together in advance and supported on the PC pellets, but if the blending amounts need to be changed depending on the molded product, it is better to manufacture master batches of the foaming agent, decomposition accelerator, organic acid, foam nucleating agent, etc., and then mix the master batches supporting each of these agents before molding.

[0289] The above-mentioned foaming agent for PC is supported on PC pellets, but it is also possible to produce the confectionery confetti by adding PC varnish while stirring ADCA powder without using PC pellets. In this manufacturing method, the concentration of ADCA per pellet is high, so it is difficult to control the foaming power. If you need to finely adjust the amount of foaming agent added (meaning to adjust the foaming power), it is convenient to use about 5wt% to 20wt% per PC pellet.

[0290] There are many polymer alloys that contain PC as the main component, such as PC / ABS, PC / PET, and PC / PBT. The master batches of the foaming agents, foaming assistants, and foam nucleating agents for PC can be made using the same ones used for PC. Of course, ABS, PET, and PBT pellets can also be used as alloys, but these PC polymer alloys, which are mainly made of PC, have a sea-island structure, so if you use a resin that will be the sea, you can simply melt and knead it with a short-axis screw in the injection molding machine, and the carrier resin of the master batch will easily disperse in the resin that is the main component of the molded product.

[0291] The solvents capable of dissolving PC are described above, but after dissolving PC, a composite solvent may be prepared by adding aromatic hydrocarbon, alcohol, etc. for viscosity adjustment, etc. In this Example 17, a foamed structure having an internal foam layer and an external skin layer can be obtained by using the GCP means of the present invention with either sodium bicarbonate, an inorganic foaming agent, or ADCA, an organic foaming agent, but the physical properties of the obtained foamed structure are significantly deteriorated with either foaming agent. As mentioned above, hydrolysis of PC causes a significant decrease in its physical properties, so the best foaming agent for PC is a liquid foaming agent such as ethanol. If dry ice pellets are placed in plasticized molten PC resin and the temperature of the heating cylinder and the temperature of the molten PC (heat, thermal energy) are used to turn the dry ice into gaseous carbon dioxide gas, which is dispersed in the PC, the problem of hydrolysis caused by foaming agents is solved. This foam molded product is suitable for painting, and there is no foaming residue, so there are no problems like when baking soda is used.

[0292] Using the method of Example 17, a master batch of PC colorants can be produced by using PC as a carrier resin and supporting a pigment for PC. A master batch of additives that impart electrical conductivity to PC can be produced by supporting carbon black, kettin black, acetylene black, carbon fiber, or CNT (carbon nanotube). This supporting method does not require melting and kneading, so it can be easily produced even if the melting temperature of the carrier resin is high, and is not limited to the production of foaming agents for PC.

[0293] Example 17 shows a method for producing a foaming agent for PC. In addition to PC varnish, an aqueous solution of polyvinyl alcohol (PVA) can also be used. Granulation can be performed using a low melting point resin, such as caprolactone powder. This method can be applied to ABS, HIPS, PP, etc., other than PC, and is not limited to PC. EXAMPLES

[0294] (Manufacture of PP foaming agent master batch) In Example 1, we described the manufacturing method of the master batch of the PP blowing agent, and the material that supports the PP resin pellets is maleic acid-modified PP, for example, ARROWBASE DB-4010 (product name) manufactured by Unitika Co., Ltd. can be used. In addition, Toyobo's PMA H1100P, PMA-F6, and NZ-1015 can also be used. NZ-1015 is an emulsion type that does not contain an emulsifier, making it easy to use. In fact, using these maleic acid-modified PP, we produced a master batch of foaming agents and foam nucleating agents by adding ADCA, sodium bicarbonate, potassium bicarbonate, monosodium citrate, etc. to PP pellets. Hardlen NZ-1015 is an emulsion type, so there is little risk of fire when heated. The production (support) of these foaming agents and other agents was shown in Example 1. In this Example 18, instead of H processing, a liquid-adding type and heating type of rocking mixer (product name) from Aichi Electric Co., Ltd. was used. Production was carried out using a device (such as a rocking mixer) with specifications that have the function of heating from the outside to evaporate water and solvents and the function of spraying (adding liquid) varnish used for the support into the device. The melting temperature of the maleic acid-modified PP is preferably close to that of the PP to be molded, but it is sufficient if it melts in the heating barrel of the molding machine, and during the metering and melt-kneading stages, and becomes compatible (soluble) in the PP. Furthermore, the master batches of the foaming agents of the present invention can be used not only for injection molding, but also for extrusion and block molding. This foaming agent master batch can also be made with PP polymer alloys such as PP / PA (PA is nylon 6, nylon 6-6, nylon 12, aromatic nylon, etc.). ADCA can be suspended in Arrowbase DB-4010 and supported on the surface of PP pellets to make a foaming agent master batch. If baking soda is dissolved in Arrowbase DB-4010 and sprayed on the surface of PP in the same way, heated, and dried, a foaming agent master batch can be made. EXAMPLES

[0295] {Manufacture of foaming agent master batches for ABS, HIPS, and modified PPO(E)} In Example 17, we described the manufacturing method of the master batch of the blowing agent for PC, but it is also possible to manufacture a blowing agent master batch for ABS by using a varnish in which ABS or AS is dissolved in MEK to support the ABS or AS resin pellets to be molded using inorganic and / or organic blowing agents. Similarly, it is possible to manufacture a blowing agent master batch for HIPS, PS, and modified PPO(E) by dissolving HIPS or PS in MEK and supporting the HIPS or PS resin pellets using inorganic and / or organic blowing agents. Of course, it is also possible to manufacture these master batches using H processing and the rocking mixer shown in Example 18. EMBODIMENT 1

[0296] In the first embodiment, as described above, the foaming agent master batch is produced by separately producing a foaming agent master batch, a foaming assistant master batch and a foam nucleating agent master batch by respectively supporting the foaming agent, the foaming assistant and the foam nucleating agent in a resin that is compatible (soluble) with the resin to be mixed, and then mixing and using the respective master batches with the resin pellets to be mixed, thereby making it possible to create the desired optimum expansion ratio, optimum foam structure and optimum size of foam cells. For example, the melting temperature of ABS is 240°C, while the thermal decomposition temperature of ADCA is approximately 230°C (it decomposes at its melting point of 225°C), so the temperature of the molten resin and the thermal decomposition temperature of ADCA are close, so a master batch of a foaming agent carrying ADCA alone will suffice, but in the case of PP, the melting temperature is low at 200°C, so mixing it with a master batch carrying urea, which has the effect of lowering the thermal decomposition temperature of ADCA, will lower the thermal decomposition temperature of ADCA.

[0297] Hydrogen carbonates such as sodium bicarbonate, citric acid, and sodium dihydrogen citrate can be made into aqueous solutions. If these aqueous solutions are placed in a Henschel mixer, for example, and heated below the temperature at which these substances (which act as foaming agents) begin to decompose while rotating the vessel, and allowed to evaporate and dry, the mixture can be granulated into a shape that can be mixed with the resin pellets used for molding, making it easier to handle than powders. A rocking mixer can also be used instead of a Henschel mixer.

[0298] Since ADCA is hardly soluble, when ADCA powder and a varnish of a resin to be mixed (for example, a MEK solution of PS (PS-doped cement) or a MEK solution of AS (AS-doped cement)) are granulated in a Henschel mixer in the same manner as in the case of hydrogen carbonate, etc., a foaming agent mainly composed of ADCA can be granulated, as explained in the above examples.

[0299] Stearic acid compounds such as stearic acid, magnesium stearate, and zinc stearate may be dissolved in a solvent such as toluene and used instead of the dope cement. In this case, stearic acid and stearic acid compounds are often used as lubricants in molding processes, so they may be used when granulating the foaming agent for PP. PVA can also be used.

[0300] The above-mentioned stearic acid or stearic acid compound solution in toluene or the like, PP pellets, and powder of an inorganic foaming agent such as sodium bicarbonate or an organic foaming agent such as ADCA may be put into a Henschel mixer and granulated. Maleic acid-modified PP may be used, or maleic acid-modified PP may be used in combination with the above-mentioned stearic acid or stearic acid compound solution in toluene or the like. EMBODIMENT 2

[0301] In the first embodiment, or when ADCA is used as a foaming agent, the foam cells formed are large. If pellets carrying sodium dihydrogen citrate or pellets carrying zinc oxide are used as a foam nucleating agent, and the pellets carrying ADCA and pellets of the resin to be blended are mixed together, fine foam cells can be obtained by the action of the foam nucleating agent. EMBODIMENT 3

[0302] When foam molding is performed using pellets carrying sodium bicarbonate, fine foam cells are obtained. However, as shown in Example 7, the foaming residue (sodium carbonate) affects the adhesion of the coating film. By adding a master batch in which sodium bicarbonate, a foaming agent, and citric acid, which reacts with the sodium carbonate in the foaming residue, are carried on pellets, foaming gas is generated by a chemical reaction with the sodium bicarbonate, and the sodium carbonate in the foaming residue, which affects the adhesion of the coating film, reacts with the citric acid, reducing the foaming residue that reduces the adhesion of the coating film, thereby improving the adhesion of the coating film. EMBODIMENT 4

[0303] Although sodium dihydrogen carbonate was used as the foam nucleating agent in the above-mentioned embodiment 2, it has been confirmed that the use of potassium dihydrogen carbonate also has the effect of making the foam cells fine. Of course, in the embodiments 1 to 3 and 4, if GCP is performed using the mold shown in Fig. 10 and Fig. 11 and the GCP device shown in Fig. 15, Fig. 16 and Fig. 9, a foam-molded product with a beautiful appearance free of swirl marks and with foam cells inside can be obtained. EMBODIMENT 5

[0304] The master batches of PP blowing agents, foaming assistants, foam nucleating agents, etc. used in the foaming molding of PP extrusion molding are manufactured by using PP, which is compatible with PP, as a base resin, and maleic acid-modified PP, which is compatible with PP, to support it. Therefore, even in the extrusion molding of PP, the PE does not come out on the surface, unlike the master batches of commercially available blowing agents used as PE base resins, as shown in Figures 1 and 2. These master batches of blowing agents, foaming assistants, foam nucleating agents, etc. are manufactured separately and mixed with PP pellets in the optimal ratio. It can also be implemented with PP / PA polymer alloys. EMBODIMENT 6

[0305] The base resin of the commercially available blowing agent used in the case of foaming molding of PC uses ABS, which is compatible with PC. As a result, the foamed molded products obtained by foaming molding of PC contain ABS to a considerable extent, and the properties of PC (such as high impact resistance) are reduced. In order to solve this problem, if a blowing agent is supported on PC using a solution in which PC is dissolved in an organic solvent, and a master batch of the blowing agent is produced, the problem of the deterioration of physical properties described above is solved. In this case, as shown in Example 17, PC with improved solvent solubility can be used rather than ordinary PC, but in addition to the one in which PC is dissolved, a varnish using a styrene-modified acrylic resin can be used. However, in this case, as mentioned above, the deterioration of physical properties of PC caused by inorganic and organic blowing agents cannot be avoided. EMBODIMENT 7

[0306] In the method of using the MU-CELL, gas is used as a foaming agent in the injection molding machine and the extrusion molding machine. As a result, in the case of an in-line injection molding machine, (1) the amount of gas to be injected is controlled by pressure control, so the pressure of the molten resin during metering changes. Accordingly, the amount of gas that enters the molten resin in the heating barrel and gives the molten resin foamability changes. As a result, there is variation in foaming, foaming power, and foamability. (2) Although a molten resin such as a liquid cannot be called a liquid, if the molten resin in the seventh embodiment of the present invention is considered to be a "liquid" in relation to the seventh embodiment, it is very difficult to pressurize and dissolve the gas in the molten resin in the heating barrel and / or finely disperse it in a short time {the time between metering (at the stage of plasticization and melt kneading)}, and if the gas is injected or extruded in a large lump without fine dispersion, it will swell and burst (burst). (3) In the case of an injection molding machine, the heated and molten resin moves to the front of the heating barrel (the screw is the bolt, and the heated and molten resin is the nut; when the bolt rotates, the nut moves forward.) In this short time, it is difficult to introduce gas into the heating barrel, finely disperse it during measurement, and impart foaming properties, especially in large molded products (heavy molded products).

[0307] The solution to this problem is to use a pre-plunger type injection molding machine, such as the UCC (Union Carbide method for foam molding) method. Instead of using a pre-plunger type injection molding machine, it is better to put gas into a small heating barrel with a small screw, for example at the top of the injection molding machine heating barrel, pre-disperse the gas, impart foaming properties to the molten resin, and then send it to the main heating barrel where injection takes place, re-mix and finely disperse the gas. Such specifications and use can be achieved with a pre-plasticizing injection molding machine manufactured by Sodick Co., Ltd.

[0308] The above mentioned gas was used, but it is not limited to gas, and liquids (such as ethanol, water, sodium bicarbonate solution, etc.) can also be used. In this case, the amount of injection is not controlled by gas pressure, but by controlling the volume with something like a syringe (plunger, piston and cylinder, etc.). Whether it is a gas or liquid, or even a solid, for example a physical foaming agent such as microballoons, or a chemical foaming agent such as baking soda or ADCA, if you use the mold structure shown in Figures 10, 11, or 37 of this invention and perform GCP using the equipment shown in Figures 15 and 16, you can obtain a molded product with a beautiful appearance without swirl marks on the surface.

[0309] Similarly, in the case of an extrusion molding machine, a small sub-heating cylinder for plasticization is provided, for example, above the main heating cylinder, and gas or liquid is poured into this cylinder to impart foaming properties. In the case of an extrusion molding machine, if gas is introduced directly into the extruder heating barrel, it will still not be dispersed well, so as with an injection molding machine, it is better to introduce the gas into a small sub-heating barrel (screw) for pre-melting, pre-disperse it in the molten resin, impart foamability, and then send it into the main heating barrel of the extruder, knead it again to finely disperse it, and extrude the foamable resin. EMBODIMENT 8

[0310] A specific method (such as a program to be installed in the molding machine) for foam molding using an injection molding machine (also simply called "molding machine" in this invention) is explained below. The sealing mold shown in Fig. 10 (a sealing mold with an ejector box structure) or Fig. 11 (a mold in which the ejector pin is sealed using a weighted O-ring, such as Fig. 24 or Fig. 25) is placed (attached) to the molding machine. The resin pellets to be foamed are mixed in advance with a foaming agent master batch in which the powder of the chemical foaming agent, such as baking soda or ADCA, is supported by varnish or the like using the means explained in this invention, or the foaming agent master batch (a form in which the foaming agent is kneaded into the resin) manufactured and sold by Eiwa Kasei Kogyo Co., Ltd., Sankyo Kasei Co., Ltd., Otsuka Chemical Co., Ltd., etc., in a tumbler or the like, or the foamable resin (a mixture of pellets to be foamed and pellets of the foaming agent master batch) mixed in an optimal ratio (for example, determined based on the size and shape of the foam cells, such as suppressing swirl marks with the pressure of the GCP device in Figures 15 and 16) using an autocolor device manufactured and sold by Kawata Co., Ltd., etc., is put into the hopper of the molding machine. In the case of a small amount, the powdered foaming agent may be supported on the surface of the pellets to be molded using oil or the like.

[0311] (Timing for starting air pressure) 10 and 11 are closed {the mold closing completion signal can be a signal from a limit switch (LS) provided on the PL of the mold} and the nozzle touch is completed, the molding machine {at the command of a program built into the PLC (sequencer) of the molding machine} opens the valve (number 46) of the GCP device connected to FIG. 16, for example, to let GCP gas into the space (L1, L2, L3) inside the mold (to pressurize, to pressurize, to apply GCP) and pressurize (compress, pressurize) the space inside the mold. The time for pressurization is when it reaches a value (time) previously input into the molding machine's PLC (also simply called PLC), or when a pressure gauge with contacts (No. 56) is used and the pressure reaches a preset value, injection of the foamable resin into the molding space begins. The molding machine and GCP device are connected by a signal cable, and they exchange signals (confirmations, commands, etc.) with each other.

[0312] The foaming agent is heated and melted in the heating cylinder, and the foaming gas generated by the thermal decomposition and chemical reaction caused by the temperature (thermal energy) in the heating cylinder and the temperature (thermal energy) of the heated and melted resin is pressurized and dissolved in the molten resin by the force of rotation of the screw installed in the heating cylinder (melting and kneading force), and the foamable resin with foamability is filled (injected) into the molding space (L2). At this time, the valve 46 is still open, so the air pressure in the spaces (L1, L2, L3) in the mold continues.

[0313] The compressed gas in L2 is pushed out to L1 and L3 through the gaps in the nesting and the ejector pins by the filling force of the foaming resin. In the case of Figure 10, this compressed gas enters the ejector box, which acts as a cushion and prevents the pressure from increasing, reducing discoloration and burning of the resin. In the case of Figure 11, there is no large space for the ejector box to function, so it is better to connect the GCP device to a device with a sub-tank numbered 55 in Figure 16 if possible. Of course, it can also be implemented in Figure 15. The reason for this is that the space of the hose connecting the GCP device and the mold in Figure 15 plays the role of numbered 55 to some extent.

[0314] (Exhaust timing) While filling L2 with the foamable resin, immediately after filling is complete, and a short time has passed since filling is complete, the injection valve indicated by number 46 is closed and the exhaust valve indicated by number 51 is opened (there are cases where number 46 is closed and number 51 is opened immediately, and cases where the timing of opening number 51 is delayed slightly), and the compressed air within the sealing mold is exhausted. The timing of exhaust is determined by a ratio (for example, a percentage) of the point at which the molding machine starts filling the molding space (start of injection) as 0 (zero) and the point at which filling is complete as 100. (Exhaust during filling) The screw position can be monitored by a servo motor, magnescale, encoder, etc., so the position can be set arbitrarily, and an exhaust signal can be output when the screw reaches the set position.

[0315] The exhaust after injection is complete uses the molding machine's filling completion signal (temporary pressure completion signal). In the case of foam molding, dwelling pressure is sometimes applied without using a cushion. The reason for this is that if dwelling pressure is not used, the screw will return due to the springiness (compressibility) of the foamable resin filled in the molding space, resulting in less variation in the weight of the molded product. The dwelling pressure and time are sufficient as long as the screw does not return, so they do not have to be very high or long. Of course, dwelling pressure is sometimes used without a cushion.

[0316] (Exhaust time, suck back) The timing for exhausting the compressed air in the space inside the mold is during injection and after filling is complete. The means for exhausting during injection is that the PLC of the molding machine monitors the injection screw position, so an arbitrary screw position {position for exhausting = position (numerical value) that confirms that the screw has passed a preset position} is input to the PLC, and when the screw reaches that position, an exhaust signal is output to the GCP device in Figure 15 or Figure 16, which opens the exhaust valve 51 to exhaust the air. When exhausting after the completion of injection, exhaust is performed immediately after the completion of injection (at the same time), after a certain time has passed after the completion of injection, or after the completion of injection, suck back (the screw moves backward) in order to reduce the pressure on the foamable resin filled in the molding space, and exhaust is performed immediately when suck back starts, during suck back (the position is input in advance in the exhaust command), immediately after suck back is completed, after a certain time has passed after suck back is completed, etc. These exhaust commands are executed by a program built into the molding machine PLC.

[0317] This is difficult with Feeser's spring type, but is perfectly possible with needle type shut-off nozzles that use hydraulic or pneumatic cylinders, or rotary valve type shut-off nozzles. Suck-back and GCP exhaust are performed separately, and the timing combinations mentioned above are free. Suck-back commands are issued by a program built into the molding machine's PLC. Similarly, in the case of hot runners, the spring type manufactured and sold by Feeser Co., Ltd. cannot be used, but those that open and close using hydraulics, air pressure, actuators, etc. can be operated in the same way as the needle type shut-off nozzle described above.

[0318] (Extended Core) When using a means having the same action and effect as the suck back (called an expanding core or breathing core in this invention) to move part of the mold back (expand) to reduce the pressure of the foamable resin filled in the molding space and facilitate foaming, the timing of exhaust is set in the same way as for the suck back. Suck back and the expanding core may be performed simultaneously in the same mold. The operation to be used for exhaust at that time is determined by observing the condition of the molded product. The expansion core is a part of the mold that is initially contracted, and then a part of the operating core is retracted using a cylinder that has the function of moving forward and backward hydraulically or pneumatically, or an actuator that incorporates a servo motor.

[0319] (Mold with shutter) A dummy shape is provided in part of the mold, a shutter is provided at the entrance, and initially the shutter is closed to fill the molding space with foamable resin, and when the shutter is opened at the right time, the foamable resin flows into the unfilled space, lowering the pressure of the foamable resin filled in the molding space and making foaming easier. The timing for opening the shutter is the same as for suck-back, and the operation is carried out according to commands from a program installed in the molding machine. In addition to providing a drive unit inside or outside the mold to open and close the shutter, the expansion core uses a mechanism to operate the ejector of the molding machine, and in addition to the ejector plate incorporating the ejector pin of the mechanism for pushing out the molded product, another ejector plate (one pair, one set) is provided in front of it, and a stepped ejector rod is provided on this, and the expansion core operates and the shutter opens and closes separately from the operation of the ejector pin (it is possible to push out the ejector plate at the front and to push out the ejector plate with the conventional ejector pin incorporated). Naturally, these commands (for example, opening and closing the shutter) are given by a program built into the PLC of the molding machine.

[0320] (Mold back, core back) In the case of mold back and core back (collectively referred to as mold back), mold back is usually started when exhaust is complete, but it may be started during exhaust. In this case, the pressure at which mold back will start is preset on the pressure gauge (numbered 56), and mold back will start when the pressure drops to the set pressure. As with suck back, a delay time can also be set for the start of mold back. Naturally, these commands are issued by a program built into the molding machine's PLC.

[0321] The purpose of mold back is to increase the expansion ratio. When using the GCP of the present invention to eliminate swirl marks on the surface and obtain a molded product with a smooth and beautiful surface, and to increase the expansion ratio to a large extent (about 2 times), mold back (Fig. 19, Fig. 20) is preferable to core back (Fig. 17, Fig. 18). The timing of mold back is not before the GCP, but when the exhaust of the GCP starts and the pressure gauge of No. 56 reaches the set pressure, or when the exhaust of the GCP is completed (when the pressure gauge of No. 56 indicates a pressure close to atmospheric pressure), or when the pressure gauge of No. 56 reaches the set pressure after exhausting the GCP, a delay time is set and mold back, etc. is started when the delay time is reached. Naturally, these commands (mold back, etc.) are given by a program built into the PLC of the molding machine. By implementing mold back, etc., the width of the PL gas vent (sometimes number 131 widens. At the same time, the PL opens all around the circumference by the distance the mold is moved back, making the gas vent larger) becomes wider, so a small amount of pressurized gas that would have entered the gap between the mold and the resin and caused raindrops is suddenly exhausted, but the inside of the filled foamable resin has not yet finished cooling and solidifying, and it still retains foaming power, so it is transferred back to the mold, resulting in a foam-molded product with a beautiful appearance and no raindrops.

[0322] As mentioned above, raindrops can be eliminated by using mold backing, but as a result of the inventor's intensive research, it has been found that it is better to use a shallow embossing rather than a glossy surface. The combined use of GCP and vacuuming is very effective. When mold backing begins, if you connect L1 to L3 in the mold space with a hose and use a vacuum device (Figure 63) at the end to reduce the pressure all at once, raindrops on the glossy surface will be eliminated and a foam molded product with a beautiful appearance will be obtained. The molds used are the seal molds shown in Figures 10 and 11, but to fully utilize the action and effect of vacuuming, it is better to have a structure in which the ejector pin, which has a small spatial volume for vacuuming, is sealed. In Figure 11, the O-ring that seals the ejector pin has a directionality, so even if the same seal is used in the opposite direction for the vacuuming mold and vacuuming is performed, air will not get in. By molding back, a thick seal or one shown in Figures 56 to 62 is used for seal 33 so that vacuuming is possible even when the PL is open, and so that sealing properties are maintained even when the PL is open. It is not possible to reduce the pressure all at once by simply connecting a vacuum pump to the mold or to the GCP device in Figures 15 and 16. It is preferable to connect a vacuum pump (177) to a receiver tank (169), reduce the pressure inside the receiver tank, and then open the valve (174) in response to a signal from the molding machine to draw a vacuum all at once.

[0323] When using GCP to form a clean skin layer on the surface of a foam molded product, if the surface temperature of the mold is high, the skin layer will be thin. For example, the mold surface temperature can be increased using a device like that shown in Figure 23. Alternatively, the mold surface can be heated by high-frequency induction heating or other methods. However, in this case, raindrops are likely to occur because the temperature of the mold surface is high. To eliminate raindrops and obtain a clean foam molded product, a molded product with a clean appearance and no raindrops can be obtained even on a glossy surface by using a mold bag or similar and drawing a sufficient vacuum. In this way, if the temperature of the foamable resin and the surface temperature of the mold are both high, GCP can be performed, and then vacuum drawing can be performed, resulting in a foam molded product with a thin wall and a clean surface.

[0324] (Vacuuming) When vacuuming the inside of the mold (strictly speaking, reducing the pressure) using the vacuum device in Figure 63 after mold backing, etc., this is done after the exhaust of the GCP is completed. After mold backing, etc. is completed, the molding machine PLC opens the port 174 and draws in part of the pressurized gas remaining in the mold into the port 169. The port 174 is opened simultaneously with the completion of mold backing, etc., or after the completion of an arbitrarily set delay time. The pressure gauge in the port 170 has the function of outputting the pressure value as necessary, and the molding machine PLC does not start clamping the mold unless the pressure is reduced (vacuumed) to below the set value. To fully utilize the effect of vacuuming, the mold with the ejector pin sealed in Figure 11 (the volume of the pressurized material is small) is better than the mold with the ejector box in Figure 10 (the volume of the pressurized material is large). In some cases, the vacuum is drawn and then the mold is clamped again (at a distance less than, or the same as, the distance used for mold backing, or at a greater distance) to perform compression molding.

[0325] (O-GCP, I-GCP) The GCP device in Figures 15 and 16 describes a means for suppressing foaming by applying pressure (pressurizing) from outside the foamable resin with gas and eliminating swirl marks on the surface. The inventor calls this the "outer GCP (O-GCP)". When blow molding, exemplified by AGI by Asahi Chemical Industry Co., Ltd. and Sympress by Mitsubishi Gas Chemical Co., Ltd., is applied to the foamable resin of the present invention, foaming is suppressed from within the molded product, from the hollow portion formed inside the molded product. For example, the device in Figure 1 described in the patent specification with application number PCT2016-86380 (hereinafter referred to as the "86380 patent") and the pins for blow molding such as Figure 124 (pins for putting high-pressure gas into the molded product) compressed in Figure 1 are installed in the molds in Figures 10 and 11 of the present invention. By making the inside hollow using Figures 1 and 124 described in the specification of the 86380 patent and venting the gas that formed the hollow, the gas pressure that suppresses foaming from the inside is released, and foaming begins in the part that was once hollow. The inventor calls this the "Inner GCP (I-GCP)J.

[0326] The I-GCP may be linked (synchronized, synchronized) with the O-GCP, but it does not have to be linked. The I-GCP starts (injection of high-pressure gas into the molded product) during injection, immediately after the completion of filling, with a delay from the completion of filling, at the start of suck-back, during suck-back, immediately after the completion of suck-back, or with a delay after the completion of suck-back. The I-GCP forms a hollow space, and exhaust is performed immediately after the injection of high-pressure gas, or with a certain delay. The program in the molding machine PLC is explained below. The foamable resin is injected after the O-GCP is applied in advance to the molding space. During injection, simultaneously with the completion of injection, or with a certain delay after the completion of injection, the valve numbered 14 in Figure 1 of the '86380 patent is opened to form a hollow space inside. If necessary, valve 14 in Figure 1 of the 86380 patent is closed to trap the high-pressure gas injected inside (retention time), and then valve 15 in Figure 1 of the 86380 patent is opened to release the high-pressure gas injected inside, which starts foaming toward the hollow interior. If the program built into the molding machine PLC for this I-GCP is implemented with a non-foamable resin, it can be used as a program for blow molding. As mentioned above, the O-GCP is controlled by the program built into the molding machine PLC.

[0327] The gas injection pin in Figure 124 of the 86380 patent used in I-GCP may be fixed, but to ensure smooth exhaust, a hydraulic or pneumatic cylinder should be provided at the rear, and it should be moved forward before high-pressure gas is injected. When exhausting (start by opening the appended number 15 in Figure 1 of the 86380 patent, and simultaneously with the start of exhausting the high-pressure gas inside, or after a certain time delay), it should be moved backward to release the pressure inside the hollow part, otherwise it will swell and burst when demolded. EMBODIMENT 9

[0328] (Gas and liquid foaming agents) In the eighth embodiment, the master batch carrying a solid chemical foaming agent is mainly used, but the foaming agent may be a gas or liquid. When gases such as nitrogen gas or carbon dioxide gas, or liquids such as water, alcohol, or sodium bicarbonate solution are injected into the heating barrel of the molding machine during metering to impart foamability to the resin during plasticization, the program in the molding machine PLC starts the injection of the gas or liquid when a signal is sent to start metering, or when a delay time is taken from the start of metering, or when the screw position is input in advance and the screw passes that position during metering.The injection of the gas or liquid is stopped when a signal is sent to complete metering, or when a predetermined time has elapsed since the start of metering, or when the screw position is input in advance and the screw passes that position during metering, a command to stop injection is output. EMBODIMENT 10

[0329] The gas used by GCP is generally air, but if discoloration or burning occurs, nitrogen gas, carbon dioxide gas, etc. can be used. Or a mixture of gases can be used. In Figures 15 and 16, a separate port (not shown) and a separate valve (not shown) are provided to pressurize the inside of the mold with the initial air, and by pressurizing L2 with a pressure higher than the pressure of the initial compressed air, the inside of L2 can be replaced with an inert gas such as nitrogen gas or carbon dioxide gas. It is also possible to use such inert gases from the beginning. Needless to say, these are also incorporated into the molding machine program. EMBODIMENT 11

[0330] The above-mentioned Shinbo method can also be applied as explained in O-GCP and I-GCP, and the command to foam the liquid foaming agent from the injection port at the rear of the nozzle at the same time as injection is also built into the molding machine program. Of course, it has been confirmed through experiments that by combining GCP with this method, molded products with beautiful appearances can be obtained.

[0331] The above-mentioned examples and embodiments are given for illustrative purposes only, and the present invention is not limited thereto. Modifications and additions are possible as long as they do not contradict the technical concept of the present invention that can be recognized by the parties concerned from the claims, the detailed description of the invention, and the drawings. [Industrial Applicability]

[0332] It is applicable to the production of foam molded thermoplastic resin products, especially those with a beautiful appearance without swirl marks and high expansion ratio.

[0333] The following diagrams are provided: a structural diagram of the mold used in the present invention; a structural diagram of the GCP device; diagrams (photographs) showing the results of the experiment; and diagrams (tables) showing the results of painting, etc. [Explanation of symbols]

[0334] 1. Gate 2. Silver streaks caused by PE near the gate 3. The swirl marks at the far end of the gate are suppressed, giving the gate a beautiful appearance. 4. Swirl marks on the surface 5. Top stopper 6. Space (space under pressure) 7. Carbonated Water 8. Container 9. Dividers 10. Space 11. Door 12. Surface bubbles 13. Beer (contains carbon dioxide) 14. Cup 15. No bubbles on the surface. 16. Spool bush 17.Fixed side mounting plate 18. A mold plate for the fixed side insert 19. Fixed side insert 20.Mating surface of the fixed side insert 21.Molding space (mold cavity, cavity, molding space, L2) 22. A mold plate that holds the movable insert 23. Movable side insert 24. Ejector pin (abbreviation: EP) 25. Ejector plate (upper) 26. Ejector plate (bottom) 27.Spacer block with sealing function 28.Moving side mounting plate 29. Hole in the Lot 30.Mating surface of movable insert 31. O-ring 32. O-ring 33. O-ring 34. Ejector mechanism 35. O-ring 36. O-ring 37.Spacer block 38. O-ring 39. Dovetail 40. Plate (top) 41. Plate (bottom) 42. O-ring 43. Compressor {with receiver tank (not shown)} 44. Horse 45. Connection between manifold 49 and injection valve 46 46. ​​Injection (pressure) valve 47. Arrow indicating the exhaust direction of GCP {gas (compressed air) injected into the mold} 48. Capra 49. Manifold 50. Connection between manifold 49 and exhaust valve 51 51. Exhaust valve 52. Flexible hose 53. Arrows showing the flow direction of the GCP (gas that pressurizes the inside of the mold) from the compressor, and arrows showing the flow of gas from the compressor to the GCP device 54. Arrows showing the flow of compressed air into and out of the mold 55. Subtank 56. Pressure gauge 57. Piping connecting to subtank 55 58. Check valve 59. Fixed side mold 60. Parting (PL) 61. Movable side mold 62. Vertical parting {Vertical parting between metals (fixed and movable molds)} 63. Arrow indicating core back (arrow indicating that 61 has been retreated) 64. Parting on flat edge 65. Arrow indicating mold back (arrow indicating that 61 has been pushed back) 66. Gaps caused by partings opening due to mold backing 67. Core-back structure, showing that the parting is opened by the core-back. 68.Molded back structure (one-sided engraving) 69.Molded back structure (double-sided engraving) 70.Tenniku 71.Heating medium 72.Magnetic material 73. IH heater coil 74. Feather 75. Magnet 76. Magnet 77. Flow control valve 78. Flow direction arrow 79.Mold insert 80. Filter 81.Heating device 82.Circulation device 83. Piping 84. For the sealing part of the load-type O-ring, materials such as Turcon (product name) and Zurcon (product name) are mainly used. 85. In the weighted O-ring, a load is applied to reference number 84, and a U-shaped stainless steel spring is inserted into reference number 84 with its opening facing upwards. 86. The opening of the U-shaped stainless steel spring shown at 85 is fitted downward for the purpose of applying a load. The material is not limited to stainless steel, but spring steel can also be used, and the shape can be the coil spring shown in Figure 29. The object used for applying a load can be not only a metal object, but also a commercially available O-ring as shown in Figure 30. 87. The lip (seal) part of the U-(V)-shaped O-ring (packing) has the same function as that of 84 shown in Figures 24 to 26. 88. The internal U (V) shape (concave) is shown. When Figure 29 and Figure 30 are fitted into the reference number 88, it becomes a load type O-ring. 89.Gas pressure pin installed in the mold 90. Gas circuit for gas pressurization 91. Gas pressure pin with double-layered ejector pin 92. Gas circuit for gas pressurization 93.Gas pressure pin installed on the movable side mounting plate 94. Gas pressure pin with double-layered ejector pin 95. Outer cylinder of gas pressure pin. The dashed line shows the hole in the ejector sleeve pin. 96. Ejector pin 97. D-cut processed to facilitate gas flow 98. Rubber sheet for sealing gas (packing) 99. Pressurized Gas 100. Gas ejection point (tip of gas pin) 101. Ribs to prevent gas leakage 102.Cross-section of molded product 103.Gas pressure pin 104. If a rough texture is applied to the gas pressure surface, the wedge effect makes it easier for the gas to enter the gap between the resin and the mold. 105. Movable side mold 106. Fixed side mold 107. The gas pressurizing pin 103 provided on the movable side mounting plate 28 was fixed to provide a gas circuit 94. 108. Gas inlet for compressed air 109. One Side 110. Foam layer trapped inside by GCP 111. Clean outer skin layer formed by GCP 112.L-shaped sticker body 113. O-Limbu 114. Housing for L-shaped seal 115. O-ring fitted for load purposes 116. Pressing block (top) 117. Pressing block (bottom) 118. O-ring 119. O-ring 120. Capra 121. Piping 122.Device for GCP to L3 123. Device for GCP to L2 124. Device for GCP to L1 125.Gas circuit inside the mold 126.Gas circuit inside the mold 127.Gas circuit inside the mold 128. Capra 129. Groove 130. Gas Vent 131. Gas Vent 132. Hole 133. Hole 134. Groove 135. Arrows showing, for example, the introduction of compressed gas into a GCP device by a compressor 136. Arrows showing the flow of compressed air 137. Arrows showing the flow of compressed air into the mold 138. Piping, circuits, hoses, etc. 139. Arrows showing the flow of compressed gas in the mold being exhausted to the atmosphere 140. Arrows showing the flow of compressed gas in the mold being sucked into the tank 141. Valve 142. Vacuum (reduced pressure) tank 143. Arrows showing the flow of gas sucked by the vacuum pump numbered 144 144. Vacuum Pump 145. Pressure gauge showing the degree of vacuum (reduced pressure) inside the tank 146. Check valve 147. Check valve 148. Check valve 149.Porous sintered metal that allows compressed air to enter and exit 150.Porous sintered metal with multi-layer inserts that allow air to enter and exit 151. Insert to fix code number 150 152. A fixed or movable mold plate for inserting a die or the like (not shown) that defines a molding space 153. Indicates the gap of the insert 154 provided for the purpose of allowing compressed air to enter and exit. 154. Nesting forming code number 153 155. Molding space where resin is filled between the movable mold and the fixed mold 156. Reference number 156 indicates the non-expanding portion when reference number 61 is retracted. 157. Schematic diagram showing the shape of the movable part entering into the molded part 158. Cross section of V-ring 159.V-ring opening 160.U-ring opening 161. U-ring opening 162. Face of an O-ring with a circular cross section 163. The opening 164 faces away from the molding space with a V seal so that the vacuum can be used to create a sufficient seal. 164. Opening of V-ring facing outward (away from the molding space) 165. U-ring opening facing outward (away from the molding space) 166. The opening 164 is oriented in the U-seal away from the molding space so that a vacuum can be applied to create a sufficient seal. 167. Check valve 168. Check valve 169. Vacuum (reduced pressure) tank 170. Pressure gauge capable of outputting a pressure signal to check the pressure within No. 169 171. Horse 172. One-touch coupler that supports vacuum pumping 173. Valve (turned on and off by signal no. 170. Vacuum compatible) 174. Valve (Vacuum compatible valve that directs the compressed air in the mold to tank 169 after mold back and core back) 175. Arrow (→) showing the flow of vacuumed compressed air 176. Manifold 177. Vacuum Pump

Claims

1. A powder of an inorganic foaming agent and / or an organic foaming agent is supported on the surface of the molding resin to be foamed or on the surface of a resin that is compatible with the molding resin to be foamed, using a varnish produced from a resin that is compatible with the molding resin to be foamed. A masterbatch of foaming agent used in foam molding.

2. In claim 1, the molding resin to be foam-molded is AS, ABS, or a molding resin containing these as main components, A powder of the foaming agent is supported on the surface of the molding resin to be foamed or on the surface of the resin that is compatible (miscible) with the molding resin to be foamed, using a varnish in which AS or ABS is dissolved using an organic solvent. A masterbatch of foaming agent used in foam molding.

3. In claim 1, the molding resin to be foam-molded is AS, ABS, or a molding resin containing these as main components, The foaming agent powder is supported on the surface of the molding resin to be foamed or on the surface of the resin compatible (miscible) with the molding resin to be foamed, using a varnish prepared by adding water to a varnish prepared by dissolving AS or ABS in an organic solvent to form an emulsion or suspension varnish. A masterbatch of foaming agent used in foam molding.

4. In claim 1, the molding resin to be foam-molded is PS, HIPS, modified PPO(E), or a molding resin containing these as main components, A powder of the foaming agent is supported on the surface of the molding resin to be foamed or on the surface of the resin that is compatible (miscible) with the molding resin to be foamed, using a varnish in which PS or HIPS is dissolved using an organic solvent. A masterbatch of foaming agent used in foam molding.

5. In claim 1, the molding resin to be foam-molded is PS, HIPS, modified PPO(E), or a molding resin containing these as main components, The foaming agent powder is supported on the surface of the molding resin to be foamed or on the surface of the resin compatible (miscible) with the molding resin to be foamed, by using an emulsion or suspension-type varnish prepared by adding water to a varnish prepared by dissolving PS or HIPS in an organic solvent. A masterbatch of foaming agent used in foam molding.

6. In any one of claims 1 to 5, the foaming agent powder is supported on the surface of the molding resin to be foamed or on the surface of the resin compatible with the molding resin to be foamed, using a varnish mainly composed of an acrylic resin or a styrene-modified acrylic resin compatible with AS, ABS, PS, HIPS, or modified PPO (E). A masterbatch of foaming agent used in foam molding.

7. The varnish according to claim 6 is an emulsion-based or suspension-based varnish. A masterbatch of foaming agent used in foam molding.

8. In claim 1, the molding resin to be foam-molded is PP or a molding resin mainly composed of PP, The PP is acid-modified to be soluble in an organic solvent, and a powder of the foaming agent is supported on the surface of the molding resin of the PP to be foamed or on the surface of the resin that is compatible (soluble) with the PP by using a varnish of the acid-modified PP. A masterbatch of foaming agent used in foam molding.

9. The varnish according to claim 8 is an emulsion-based or suspension-based varnish. A masterbatch of foaming agent used in foam molding.

10. A raw material for molding to be used in molding, which is made by mixing a powder of a foaming agent and a varnish, evaporating to dryness, granulating and solidifying the mixture, and granulating the mixture, is composed only of the foaming agent and the resin of the varnish. A masterbatch of foaming agent used in foam molding.

11. The raw material for molding used in the molding process of claim 10 is obtained by evaporating and drying the foaming agent, the varnish, and a powder of a molding resin to be foamed and / or a powder of a resin compatible with the molding resin to be foamed, followed by solidification and granulation. A masterbatch of foaming agent used in foam molding.

12. In claim 1, the foaming agent is based on ADCA, HDCA, DPT, bicarbonate, or medium air. A masterbatch of foaming agent used in foam molding.

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