Three-dimensional QR code on surface of resin molded body, resin molding die, and method for manufacturing the same

Abstract

To provide a resin molding die for forming a three-dimensional QR code on a surface of a resin molded product, and a method for manufacturing the same.SOLUTION: There is provided a method for manufacturing a concave resin molding die in which an engraved block is formed by: a surface treatment step of coating a surface of metal powder having a predetermined particle size with a coupling agent; a step of mixing and solidifying a thermosetting resin and the surface-treated metal powder, followed by crushing and classifying a mixture to obtain a metal-resin composite powder; a step of creating a convex die of a resin molded product shape to which a QR code pattern based on three-dimensional data is transferred using a three-dimensional modeling device; and a step in which the metal-resin composite powder is introduced into an upper space of a convex die placed on a lower punch in the die, heated to a B-stage temperature at which the resin component is in a plastic state, and compression-molded together with an upper punch, to form a three-dimensional QR code as an uneven collection of fine area cells, which is then cooled and solidified in the die, and after de-molding, hardened in an atmosphere at a hardening temperature of the thermosetting resin.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] This invention 、 Resin molding A code pattern formed three-dimensionally as a fine uneven surface on the body surface can be transferred as a fine uneven surface. This relates to resin molding dies and their manufacturing methods. [Background technology]

[0002] Traditionally, Resin molded body Barcodes and QR codes are used as means of displaying various production management information. Code patterns such as However, after molding, as a separate process Resin molding surface They are used by printing on them or by attaching printed labels. Furthermore, barcodes have limitations when it comes to displaying a large amount of management information. 、 The display of QR codes is increasing.

[0003] These conventional methods require the introduction of dedicated equipment and increased labor costs as a separate process after molding. Furthermore, whether direct printing or applying printed labels, changes in the environment limit the long-term sustainability of the display depending on the ink and printing material. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2017-136666 [Overview of the project] [Problems that the invention aims to solve]

[0005] However, as a means of indicating various information such as product specifications, handling precautions, or model numbers as shown in Patent Document 1, labels displaying various information are printed as barcodes during the assembly process and affixed to limited locations on the product. Also, attaching a label printed as a QR code according to an increase in the amount of information, restrictions on the shape of a product part, or the area of the attachment position results in additional work and an increase in the number of man-hours.

[0006] An object of the present invention is to provide a fine concavo-convex shape capable of presenting a large amount of information within a limited area of a resin molded body in a molding process, and Code Patterns by directly forming it at the time of molding, to eliminate the manual label attachment work, and to provide a resin molding die having a molding surface with a fine concavo-convex shape that is difficult to process in a normal Resin molding die and a method for manufacturing the same.

Means for Solving the Problems

[0007] To achieve the above objective, the present invention provides a resin molding die for transferring a fine uneven shape to the surface of a resin molded body, comprising a molding surface having a recessed shape transferred based on a convex shape formed by three-dimensional molding, wherein the molding surface is formed by compressing a metal-resin composite containing metal powder and a thermosetting resin while heating it in a temperature range in which the thermosetting resin becomes plastic, then cooling and solidifying it, and further curing it, thereby maintaining the fine uneven shape with a strength that allows for release.

[0008] Preferably, the aforementioned fine uneven shape is an aggregate of uneven surfaces that constitutes a QR code cell pattern.

[0009] Furthermore, it is desirable that the molded surface is formed by curing a metal-resin composite, which is a compound of metal powder and thermosetting resin, and that the metal powder is surface-treated with a coupling agent.

[0010] Furthermore, it is desirable that the resin molding die contains at least one of the following metal powders: iron, aluminum, tungsten, stainless steel, titanium, zinc, tin, copper, lead, magnesium, chromium, cobalt, nickel, zirconium, molybdenum, silver, neodymium, platinum, gold, and samarium.

[0011] The present invention relates to a method for manufacturing a resin molding die, comprising: a surface treatment step of coating the surface of a metal powder with a coupling agent; a step of mixing a thermosetting resin with the surface-treated metal powder, solidifying it, and then crushing and classifying it to obtain a metal-resin composite powder; a step of creating a convex mold having a fine uneven shape using a three-dimensional molding device; a step of introducing the metal-resin composite powder into a die placed on a lower punch with the convex mold, and compressing and molding it while heating it to the B-stage temperature at which the resin components become plastic; and a step of releasing the molded body after it has cooled and solidified, and then heating it at the curing temperature of the thermosetting resin to cure it.

[0012] In the above manufacturing method, it is desirable that the fine uneven shape is an aggregate of unevenness that constitutes a QR code cell pattern.

[0013] Furthermore, in the above manufacturing method, the pressure during compression molding is 2 to 3 tons / cm². ,

[0015] , , According to the present invention, by combining transfer based on a convex mold formed by three-dimensional molding with heat compression molding and curing of a metal-resin composite containing metal powder and thermosetting resin, it becomes possible to directly transfer a fine uneven shape to the surface of a resin molded body during molding. ,

[0014] , , , Furthermore, according to the present invention, by combining a convex mold formed by three-dimensional molding with heat compression molding in the B-stage temperature range, it becomes possible to transfer fine uneven shapes with high shape reproducibility. , Furthermore, the above configuration makes it possible to provide a resin molding die that can hold the fine uneven shape with sufficient strength to allow for release. , , , Furthermore, in the above manufacturing method, the pressure during compression molding is 2 to 3 tons / cm². , , Furthermore, the resin molding method according to the present invention is characterized by mounting the resin molding die as an insert for the resin molding die and transferring the fine uneven shape to the surface of the resin molded body. , , , Furthermore, in the above manufacturing method, it is desirable that the heating temperature during compression molding is 60 to 130°C and the temperature during the curing process is 160 to 220°C. ,

[0016] , It is desirable that this be the case. , ,

[0017] , 2 , , , It is desirable that this be the case.

[0014] Furthermore, in the above manufacturing method, it is desirable that the heating temperature during compression molding is 60 to 130°C and the temperature during the curing process is 160 to 220°C.

[0015] Furthermore, the resin molding method according to the present invention is characterized by mounting the resin molding die as an insert for the resin molding die and transferring the fine uneven shape to the surface of the resin molded body.

Effects of the Invention

[0016] According to the present invention, by combining transfer based on a convex mold formed by three-dimensional molding with heat compression molding and curing of a metal-resin composite containing metal powder and thermosetting resin, it becomes possible to directly transfer a fine uneven shape to the surface of a resin molded body during molding. Furthermore, the above configuration makes it possible to provide a resin molding die that can hold the fine uneven shape with sufficient strength to allow for release.

[0017] Furthermore, according to the present invention, by combining a convex mold formed by three-dimensional molding with heat compression molding in the B-stage temperature range, it becomes possible to transfer fine uneven shapes with high shape reproducibility. In addition, by including a step of cooling and solidifying after heat compression molding, and then further hardening, it is possible to obtain a molded body that has sufficient strength to be released from the mold while maintaining its fine uneven shape. [Brief explanation of the drawing]

[0018] [Figure 1] This is a process diagram for producing a metal resin composite powder according to an embodiment of the present invention. [Figure 2] This is a process diagram for manufacturing a resin molding die (concave mold) via a QR code convex mold fabricated using three-dimensional molding technology based on CAD data according to an embodiment of the present invention. [Figure 3] This is a photograph of a convex embodiment including a three-dimensional QR code, fabricated using three-dimensional modeling technology based on CAD data according to an embodiment of the present invention. [Figure 4] This is a photograph of an example of a resin molded recess with a QR code transferred onto it, obtained by molding and curing a metal resin composite powder according to an embodiment of the present invention via a convex mold containing a QR code. [Figure 5] This is a photograph of an example of a resin molded product injection-molded using a concave mold containing a QR code for resin molding according to an embodiment of the present invention. [Modes for carrying out the invention]

[0019] The following description of this embodiment will be made with reference to the drawings. Figure 1 is a process diagram for manufacturing the metal resin composite powder according to this embodiment. First, in order to be suitable for molding fine shapes, the coarse powder is cut using a sieve or the like to obtain a predetermined particle size, and the surface of the metal powder is then composited. thermosetting resin The process involves a surface treatment step in which the metal powder is coated with a coupling agent to enhance its bonding properties, and then the two components of the surface-treated metal powder and thermosetting resin are compounded, crushed, and classified to obtain a metal-resin composite powder used in the process shown in Figure 2.

[0020] Figure 2 shows a QR code pattern transferred based on 3D data using a 3D printing device. Having a fine uneven surface A convex mold is created, and the metal-resin composite powder obtained in Figure 1 is placed in the upper space of the convex mold, which is set on the lower punch inside the die. thermosetting resinThe material is obtained by heating the components to the B-stage temperature at which they become plastic, and then compression molding them together with the upper punch to form a three-dimensional QR code as an aggregate of fine-area cells with uneven surfaces, followed by cooling and solidification within the mold, and then curing after demolding in an atmosphere at the curing temperature of the thermosetting resin. A resin molding die (concave type) having a molded surface. This invention provides a method for manufacturing [the product].

[0021] Figure 3 is a photograph of an example of a convex shape obtained by the process shown in Figure 1 of the present invention, including a metal-resin composite powder and a three-dimensional QR code molded using three-dimensional molding technology based on the 3D CAD data shown in Figure 2. 。

[0022] Figure 4 shows the result obtained by a process in which a three-dimensional QR code mold, created using three-dimensional molding technology based on the 3D CAD data shown in Figure 2, and a metal-resin composite powder are heated to the B-stage temperature where the resin components become plastic, and then compressed and molded together with an upper punch, followed by cooling and solidification, demolding, and then curing in an atmosphere at the curing temperature of the thermosetting resin. Resin molding die (concave type) This is a photograph of an example of the application.

[0023] Figure 5 is a photograph of an example of a resin molded body produced by injection molding using the resin molding concave mold shown in Figure 4, mounted on an injection molding machine.

[0024] It is created using a convex mold that forms a QR code cell, which is created with a three-dimensional 3D printer. Resin molding die (concave type) To ensure strength and thermal conductivity during resin molding, the metal-resin composite powder is obtained through a surface treatment process in which the surface of metal powder with a predetermined particle size is coated with a coupling agent, and a process in which a thermosetting resin having the characteristic of going through a B stage (semi-cured state) to a fully cured state is combined and solidified with the surface-treated metal powder, followed by crushing and classification.

[0025] Metal powders include iron, aluminum, tungsten, stainless steel, titanium, zinc, tin, copper, lead, magnesium, chromium, cobalt, nickel, zirconium, molybdenum It may also contain one or more metals selected from silver, neodymium, platinum, gold, and samarium. The above metals are atomized using methods such as reduction, electrolysis, and atomization, depending on their intended use. Coarse and fine particles of a certain size are removed to achieve a predetermined particle size distribution, and generally, the maximum particle size is controlled to be between 105 and 212 μm.

[0026] The metal powder of the present invention is , metal resin composite To improve the bonding strength 、 Particle size 100μm or more 、 Preferably, coarse powder larger than 63 μm is classified and removed. The metal-resin composite Formulated to form Thermosetting resin To improve the bonding strength with 、 Surface treatment is performed using a surface treatment agent that has multiple different reactive groups in its molecule.

[0027] Surface-treated metal powders are formulated with epoxy resins or polyester resins as the main components, along with amine-based and isocyanate-based curing agents and additives, to enhance shape reproducibility and post-molding solidification properties, thereby creating a high-density structure. thermosetting resin The composite material is mixed by adding and mixing at a ratio of 20 wt% or less, and then kneading it into a paste state that has been plasticized at a constant heating temperature, and then crushing and classifying it. Metal-resin composite powder Let's assume that.

[0028] Alternatively, a slurry is obtained by uniformly mixing surface-treated metal powder with epoxy resin or polyester resin as the main components, along with amine-based and isocyanate-based curing agents and additives, and adding a solvent such as methyl ethyl ketone that vaporizes at a low temperature of around 100°C. After wet mixing, the slurry is flattened using a doctor blade, and the solvent components are vaporized and removed to obtain a plate-like solidified material, which is then crushed and classified. Metal-resin composite powder Let's assume that.

[0029] obtained Metal resin composite powder, A three-dimensional 3D printing device positioned in a space consisting of a lower punch and a die. This results in a finely textured surface. Place it on the convex shape, The thermosetting resin becomes plastic. After pressure molding using upper and lower punches at a temperature above the B stage temperature 、 It is cooled.

[0030] The equipment used for pressure molding is equipped with a mechanism to control the heating and cooling of the mold. Metal-resin composite powder The system incorporates a mold into which the material has been introduced, and is characterized by a mechanism that controls the temperature range above and below the thermal distortion temperature at which the thermosetting resin becomes plastic (B-stage region), pressurizes at the upper limit, cools at the lower limit, and allows the solidified molded body to be released from the mold. Resin molded body shape The concave mold is cooled to a temperature that allows for release from the compression molding die after pressure molding and then removed. However, it is also effective to have a mechanism that allows for forced cooling in addition to natural cooling.

[0031] The upper limit temperature for pressure molding is preferably in the range of 10°C or more above the heat distortion temperature and 30°C or less below the curing start temperature, while the lower limit temperature for demolding is preferably in the range of 20°C or less above the heat distortion temperature, and is determined according to the shape and dimensions of the molded product formed in the mold and the productivity.

[0032] In compression molding, which is commonly performed using powder metallurgy, the final sintering strength is typically increased to 5-9 tonns / cm² for iron-based materials. 2 While high pressure is required, the resulting strength is very low, limiting the ability to form finely uneven shapes. In contrast, the process of the present invention uses 2-3 tons / cm². 2 As a result, the strength after molding is high, and there is no need to use a large press machine or take precautions against mold damage.

[0033] During heat compression molding, the thermosetting resin initially flows and fills the spaces between metal particles in the mold. As it cools from the pressurized temperature range, it acts as a binder between the metal particles, and the molded body maintains its shape before being released from the compression mold as a solidified molded product.

[0034] The thermosetting resin after compression molding is , fluid state Cooling and solidifying By doing Binder between metal particles It functions as, molded While maintaining the micro-uneven shape Release from compression molding die So , Subsequently, it hardens when heated to the curing temperature of the thermosetting resin, becoming a component that forms the molded surface.

[0035] The resulting concave shape is pressed in a plasticized state, thus forming a QR code with fine area cells. Fine irregularities The shape is faithfully reproduced, and the resin molded body obtained using a concave mold is Fine uneven shape This results in a three-dimensionally formed surface, making it an effective technology for creating ultra-fine patterns and shapes on the surface of general resin molding dies.

[0036] In general powder metallurgy molded products, sintering is performed with a temperature profile ranging from 500°C to 1200°C for about 4 to 6 hours to achieve chemical bonding after molding, depending on the metal composition. However, in this invention, the solidified molded body, which is removed from the mold in a solidified state where the resin component functions as an adhesive, is left to stand in a constant temperature bath heated to a curing temperature of around 200°C for about 10 to 30 minutes. After the resin component has completely hardened, it is removed from the bath and cooled, resulting in a hardened concave molded body for the purpose of creating a QR code on the resin molded body.

[0037] The constant-temperature bath used in the curing process of the present invention can accommodate molded bodies in batches using a general-purpose batch drying device, significantly reducing equipment costs, installation area, and energy consumption compared to conventional powder metallurgy molding. It also eliminates the need for temperature profile setting and atmosphere control in the sintering furnace.

[0038] The present invention involves a surface treatment step in which the surface of metal powder with a predetermined particle size is coated with a coupling agent, and a step in which a thermosetting resin is composited. Metal composite resin powder The QR code cell is formed by a convex mold created with a 3D printing device, and the curable resin is plasticized in a temperature range of approximately 60-130°C. In the B-stage state, 2-3 tons / cm³ of material are compressed into the mold. 2 Pressurize with thermosetting resin The molding process involves using the fluidity of the material to create the shape, followed by cooling and solidification to maintain the shape, after which demolding is performed, and finally a curing process at 160-220°C for 10-30 minutes. resin molded surface This provides a resin molding die capable of creating three-dimensional QR code cells.

[0039] obtained A resin molding die having a molding surface with fine irregularities is, between metal powder particles Binding material Used as Heat Curable resin 、 three dimensional Formed by shapingIt has sufficient strength to withstand the transfer and release processes with the convex mold, and furthermore, during molding pressure It has sufficient strength to withstand force and temperature. And temperature control There It possesses effective properties.

[0040] In conventional resin molding, molds are assembled by cutting and machining metal blocks. It is difficult to form fine uneven shapes with high precision, especially fine dimensions. A collection of bumps and ridges of mold In some cases, it is difficult to achieve without increasing the dimensions. Also, Directly through three-dimensional modeling Forming a mold If that happens , the above A block of metal Formed by processing Compared to molds hand Thermal conductivity and mechanical strength It's low and not very practical.

[0041] (Effects and effects of this embodiment) This embodiment According to Coarse powder with a predetermined particle size or larger is cut, using a metal powder surface-treated with a coupling agent having two or more different reactive groups in its molecule, and a thermosetting resin as a binder that plasticizes in a specific temperature range (B stage) to enhance the fluidity of the metal powder. Metal-resin composite powder The material is produced, shaped using a 3D printing device, and then placed into a convex mold space mounted in a compression molding device. After heating and pressurizing, a subsequent curing process is performed to obtain a concave shape for the 3D QR code cell and cell pattern. Resin molded body It is possible to directly fabricate three-dimensional QR code cells on the surface without using special equipment or high energy, thereby creating fine, uneven shapes.

[0042] The surface-treated metal powder is pre-compounded using methods such as paste mixing in the plasticized state of a thermosetting resin having a B stage, or a wet mixing sheet formation method using a solvent. After crushing, the coarse powder is cut off and the resulting powder is introduced into the compression molding process. Its high fluidity during molding transfers the fine irregularities within the mold, and it has sufficient strength upon release from the mold, and the final thermosetting process... via It possesses sufficient strength and thermal conductivity nearly equivalent to that of ordinary metal molds. Resin molding die You can obtain it.

[0043] Metal powder and compound thermosetting resinThe pressure used when performing compression molding in the plasticized temperature range is 2-3 tons / cm². 2 While molding is possible at low pressure, conventional powder metallurgy manufacturing requires the addition of many lubricants, resulting in a pressure of 5-7 tons / cm³. 2 This is the general practice, and applying even greater pressure is limited by equipment and mold strength. Forming three-dimensional QR codes and other micro-area shapes as aggregates of uneven surfaces of micro-area cells is impossible in the unsintered state after molding due to insufficient strength, making demolding while maintaining the molded shape impossible.

[0044] Furthermore, in this embodiment, the heating temperature during compression molding is thermosetting resin The plasticization temperature can be set in the range of 60 to 130°C, and the final hardening temperature after molding and cooling is 160 to 220°C. It only needs to be left to stand for about 10 to 30 minutes. In this embodiment, small equipment such as ordinary dryers can be used, and it is possible to significantly reduce energy costs compared to powder metallurgy processes that require large sintering furnaces, and it also makes a big contribution to decarbonization. In addition, the shrinkage rate is smaller than that of sintering in powder metallurgy, and dimensional accuracy can also be improved.

[0045] Furthermore, in this embodiment, the convex mold on which the three-dimensional QR code, which is an aggregate of bumps and depressions of fine-area cells obtained by three-dimensional additive manufacturing, is formed can be designed and manufactured in just 1 to 2 days. Moreover, the concave mold obtained by powder molding and curing processes using this can also be manufactured in a similar number of days, and is attached to the mold base as a nesting piece. Resin molding die This allows us to provide resin molding dies in significantly shorter timeframes and at lower costs.

[0046] Furthermore, in this embodiment, the convex mold on which the three-dimensional QR code, which is an aggregate of bumps and depressions of fine-area cells obtained by three-dimensional additive manufacturing, is formed can be designed and manufactured in just 1 to 2 days. Moreover, the concave mold obtained by powder molding and curing processes using this can also be manufactured in a similar number of days, and is attached to the mold base as a nesting piece. Resin molding die This allows us to provide resin molding dies in significantly shorter timeframes and at lower costs.

[0047] (other implementation form) The manufacturing method of the resin molding die of the above-described embodiment is an example of a preferred form of the present invention, but it is not limited thereto, and various modifications can be made without changing the gist of the present invention.

[0048] As a surface treatment agent for metal powder to improve the bonding force with a thermosetting resin for forming a thermosetting molded body, it is possible to use treatment agents such as titanate-based, silane-based, and graphene oxide.

[0049] The thermosetting resin having a B-stage added to the metal powder has a plasticizing temperature of around 90 °C 、 and a curing temperature of around 200 °C is desirable.

[0050] In addition, in the present embodiment, the metal resin composite powder formed by crushing and classifying after dry mixing or wet mixing is put into the upper space of the convex die where the three-dimensional QR code is formed on the lower punch in the die and compressed, but the pressure during compression molding is 2 - 3 tons / cm 2 However, depending on the combination of the metal powder and the thermosetting resin added, the compression pressure may be less than 2 tons / cm 2 or may exceed 3 tons / cm 2 is also acceptable.

[0051] Also, in the present embodiment, the plasticizing temperature is around 100 °C and the curing temperature is around 200 °C. However, depending on the combination of the metal powder and the thermosetting resin added, the temperature during compression molding at the B-stage is preferably in a region that is 10 °C or higher than the heat distortion temperature and 30 °C lower than the curing temperature, and the curing time for standing in a constant temperature bath set at the curing temperature is 10 - 30 minutes.

[0052] In addition, the concave die with the three-dimensional QR code formed can be modularized and used as an insert mounted on a part of a general resin molding die manufactured by machining a metal block. The present embodiment can be applied to molding methods other than injection molding, such as vacuum molding and blow molding.

Example

[0053] The metal powder used was 、 These are iron-based particles (Höganäs Somaloy: ASC100.29) commonly used in powder metallurgy manufactured by atomization. The particle size distribution of this metal powder is shown in Table 1. Although this invention contains a large amount of coarse powder, it is possible to refine it during the metal powder manufacturing process.

[0054] [Table 1]

[0055] To enhance bonding with thermosetting resins and to create three-dimensional QR code cells and cell patterns formed as a collection of fine-area cell-sized irregularities, surface treatment of metal powder is performed by cutting coarse iron powder of 63 μm or larger into a stirring and mixing device, adding an alcohol-diluted coupling agent dropwise while mixed, and evaporating the alcohol through shear heat during mixing to perform the surface treatment. The coupling treatment conditions involved adding 6500g of iron powder to a Henschel mixer and slowly rotating and dripping a treatment solution containing 12.5g of Ajinomoto's PlainAct 46B (a titanate-based compound) dissolved in 62.5g of ethanol. To evaporate the alcohol through shear heating and the heating assistance of the mixing equipment, the mixture was rotated and mixed at 130°C for 45 minutes, after which it was cooled to 40°C using the equipment's cooling device before discharge and recovery. To evaporate the alcohol using shear heating and the heating assistance of the mixing equipment, the mixture was rotated and mixed at 130°C for 45 minutes, and then cooled to 40°C using the equipment's cooling device before being discharged and recovered.

[0056] Thermosetting resins Toagosei Using E-150BK14S, which consists of epoxy and amine curing agents from the company, the mixture was heated to a paste state on a hot plate heated above its softening point. The iron powder after the titanate surface treatment was then added in appropriate amounts in a predetermined ratio, mixed, kneaded, and cooled. The kneading temperature was 130°C, 40°C higher than the softening point of the thermosetting resin E-150BK14S (90°C), and the addition ratio of thermosetting resin was 8 parts for every 100 parts iron powder.

[0057] To enhance the bonding between iron powder and thermosetting resin, the mixture was kneaded in a paste state to create a composite, and after cooling, it was formed as a collection of uneven surfaces with a fine area cell size. To create three-dimensional QR code cells and cell patterns, the mixture was crushed at room temperature using a grinding device, and the coarse powder was removed using a 63 μm sieve to obtain a particle size equivalent to the original iron powder particle size.

[0058] On the other hand, in order to create a three-dimensional QR code cell and cell pattern, which are fabricated as an aggregate of bumps and dips of a micro-area cell size, as well as a textured surface that simulates a fine pattern, three-dimensional CAD data of the molded body shape was created. Based on the obtained CAD data, a convex mold was created using a three-dimensional printing device, transferring the QR code pattern and multiple fine patterns based on the three-dimensional data. The three-dimensional printing device used was a fomlabs-Form3, and the material used was Rigid 10K Resin with a layer thickness of 0.025 mm. The photograph shown in Figure 3 is a convex mold containing a three-dimensional QR code fabricated using three-dimensional printing technology.

[0059] Metal-resin composite powder is placed in the upper space of a convex mold positioned on the lower punch inside the die. thermosetting resin After raising the temperature to 140°C, the B-stage temperature range where it becomes plastic, 2.5 ton / cm³ 2 Compression molding was performed, followed by cooling in the mold, demolding, and then the material was left to stand in a 200°C constant temperature bath for 20 minutes to fully cure. Resin molding die We created a constant temperature bath. A constant temperature bath is a common piece of equipment, and it is simpler to use than a sintering furnace in the powder metallurgy process, and it also significantly reduces thermal energy consumption. The photograph shown in Figure 4 was obtained using a convex mold with a three-dimensional QR code and a metal-resin composite powder. Resin molding die (concave type) That is the case.

[0060] obtained concave After injection molding, the mold was opened to remove the resin molded body by machining ejector pin guide holes. This was then mounted as an insert in the resin molding mold base and attached to the BabyPlast6t / 12 molding machine for the molding process. The molding resin used is ABS pellets, and the cooling time is 20 seconds. in The process was carried out, and the resulting resin molded product is shown in Figure 5.

[0061] We confirmed that the information contained in the 3D QR code shown in Figure 5 can be read using a smartphone's QR code reader.

Claims

1. A resin molding die for transferring a fine uneven shape to the surface of a resin molded article, The molded surface has a recessed shape transferred based on a convex shape formed by three-dimensional molding, and the molded surface is formed by compressing a metal-resin composite containing metal powder and thermosetting resin while heating it in a temperature range in which the thermosetting resin becomes plastic, then cooling and solidifying it, and further curing it, thereby maintaining the fine uneven shape with a strength that allows for release. A resin molding die characterized by the following features.

2. The resin molding die according to Claim 1, wherein the fine uneven shape is an aggregate of unevenness constituting a QR code cell pattern.

3. A resin molding die according to claim 1 or 2, The aforementioned molded surface is formed by curing a metal-resin composite, which is a compound of metal powder and a thermosetting resin, and the metal powder is surface-treated with a coupling agent in the resin molding die.

4. A resin molding die according to claim 1 or 2, A resin molding die in which the metal powder comprises at least one selected from iron, aluminum, tungsten, stainless steel, titanium, zinc, tin, copper, lead, magnesium, chromium, cobalt, nickel, zirconium, molybdenum, silver, neodymium, platinum, gold, and samarium.

5. A surface treatment step of coating the surface of a metal powder with a coupling agent, A process to obtain a metal-resin composite powder by mixing a thermosetting resin and the surface-treated metal powder, solidifying the mixture, and then crushing and classifying it, A process of creating a convex mold with fine irregularities using a three-dimensional molding device, The process involves placing the aforementioned convex shape on a lower punch and inserting the metal-resin composite powder into the die, and then compressing and molding it while heating it to the B-stage temperature at which the resin components become plastic. The process involves cooling and solidifying the molded body, then demolding it, and finally heating it at the curing temperature of the thermosetting resin to cure it. A method for manufacturing resin molding dies that include [the specified component].

6. The method for manufacturing a resin molding die according to claim 5, wherein the fine uneven shape is an aggregate of unevenness constituting a QR code cell pattern.

7. A method for manufacturing a resin molding die according to claim 5 or 6, wherein the pressure during compression molding is 2 to 3 tons / cm².

8. A method for manufacturing a resin molding die according to claim 5 or 6, wherein the heating temperature during compression molding is 60 to 130°C and the temperature during the curing process is 160 to 220°C.

9. A resin molding method comprising attaching the resin molding die described in Claim 1 or 2 as an insert to the resin molding die and transferring the fine uneven shape to the surface of a resin molded body.

Images