Membrane material for IMD injection molding, preparation method of membrane material and IMD injection molding method

Abstract

The invention relates to the field of injection molding processes, in particular to a membrane material for IMD injection molding, a preparation method of the membrane material and an IMD injection molding method. The membrane material for IMD injection molding comprises a carrier layer, an ink layer is arranged on the inner side of the carrier layer, a white bottom layer is arranged on the inner side of the ink layer, a bonding layer is arranged on the inner side of the white bottom layer, and the carrier layer is a PET sheet or a PC sheet. The film material for IMD injection molding is simple in structure and can be used for preparing an IMD product, the adhesive force of the bonding layer to the injection molding material ABS resin is high, boiling resistance is achieved, good dry and wet aging resistance is achieved, the tensile strength of the IMD product is remarkably improved, and practicability is high. The preparation method of the membrane material for IMD injection molding and the IMD injection molding method using the membrane material are simple in process, easy to control in operation and beneficial to industrial mass production, and the prepared IMD product is stable in quality and excellent in comprehensive performance.

Description

Technical Field

[0001] This invention relates to the field of injection molding processes, and more specifically to film materials for IMD injection molding, their preparation methods, and IMD injection molding methods. Background Technology

[0002] In-Mold Decoration (IMD) is a surface decoration technology, also known as in-mold decoration or paint-free technology. It involves embedding a printed decorative film (sheet) into the mold during injection molding, fusing the decorative pattern with the surface of the plastic part to achieve a high-fidelity and wear-resistant decorative effect. IMD technology is widely used in various products requiring aesthetically pleasing and durable surfaces, such as mobile phone screen lenses and casings, home appliance control panels, automotive dashboards, body parts, rice cooker control panels, mobile phone cases, and toy car shells. Current technologies generally use ABS, PC, and PMMA plastic materials for IMD injection molding, with PET or PC sheets as the carrier layer. However, in actual production applications, existing IMD material systems still face key technical bottlenecks. The core issue lies in the poor adhesion between the decorative film's adhesive layer and the injection molding substrate, resulting in poor water resistance. Summary of the Invention

[0003] In order to overcome the shortcomings and deficiencies of the existing technology, the purpose of this invention is to provide a film material for IMD injection molding. It has a simple structure, can be used to prepare IMD products, and its adhesive layer has strong adhesion to the ABS resin injection molding material. It is also resistant to boiling water, has good resistance to dry and wet aging, significantly improves the tensile strength of IMD products, and has strong practicality.

[0004] The method for preparing the film material for IMD injection molding according to the present invention is simple, easy to operate and control, which is conducive to large-scale industrial production. The film material obtained for IMD injection molding has stable quality and excellent comprehensive performance.

[0005] The objective of this invention is achieved through the following technical solution: a film material for IMD injection molding, comprising a carrier layer, an ink layer disposed on the inner side of the carrier layer, a white underlayer disposed on the inner side of the ink layer, and an adhesive layer disposed on the inner side of the white underlayer.

[0006] Furthermore, the carrier layer is a PET sheet or a PC sheet.

[0007] The film material used in this invention for IMD injection molding consists of a carrier layer, an ink layer, a white underlayer, and an adhesive layer, arranged from the outside to the inside. The carrier layer is mainly made of PET and PC. PET film has excellent printability, dimensional stability, and cost advantages, while PC film has better impact resistance and high temperature resistance, making it suitable for more demanding application scenarios. The white underlayer is used to enhance the color performance and opacity of the ink layer, and the adhesive layer is used to achieve a tight bond between the film material and the injection molding substrate. This results in a comprehensive effect of beautiful appearance, weather resistance, wear resistance, stable yield, and integrated injection molding.

[0008] Furthermore, the ink layer is a UV ink layer.

[0009] Furthermore, the white underlayer comprises the following components in parts by weight: 40-50 parts of hydroxyl acrylic resin, 15-25 parts of polyester resin, 60-70 parts of the first solvent, 8-12 parts of titanium dioxide, and 65-75 parts of curing agent.

[0010] The white underlayer of this invention is prepared by hydroxyl acrylic resin, polyester resin, a first solvent, titanium dioxide, and a curing agent. It has high opacity, high adhesion, heat resistance, and injection molding fusion stability. The components work together well and have good compatibility. Among them, titanium dioxide provides stable whiteness and opacity. The film formed by the superposition of hydroxyl acrylic resin and polyester resin has uniform film thickness and consistent whiteness, effectively masking the background color and defects of the injection molding material, and significantly improving the color saturation and contrast of the ink layer. The two-component cross-linking of hydroxyl acrylic resin and polyester resin forms a dense paint film with strong interlayer adhesion to the ink layer and adhesive layer. It is not easy to delaminate or bubble under the impact of high temperature melt during injection molding. At the same time, it is also resistant to friction, solvent, and weathering. It is not easy to yellow or fade with long-term use. Moreover, the compound of hydroxyl acrylic resin and polyester resin balances hardness and flexibility. It is resistant to tensile stress and cracking during hot pressing and is suitable for complex curved surfaces.

[0011] Furthermore, the hydroxyl acrylic resin is selected from at least one of BASF Joncryl 587, Arkema Synocure 862X 60 MY, or Hemings Dechen Hypomer FS-2460AF.

[0012] Furthermore, the polyester resin is selected from at least one of Laiyang Hongan 4500 / 4600 or Haiming Sideqian PE series PE-8043.

[0013] Furthermore, the first solvent comprises the following components in parts by weight: 40-50 parts of isophorone and 15-25 parts of trimethylbenzene.

[0014] The first solvent of this invention is prepared from isophorone and trimethylbenzene, forming a slow-evaporating solvent system with high boiling point and strong dissolving power. It is suitable for the two-component PU crosslinking system of white underlayer hydroxyl acrylic resin and polyester resin, and takes into account the stability of printing leveling, thermoforming and injection molding fusion.

[0015] Furthermore, the curing agent is an aliphatic polyisocyanate. Preferably, the aliphatic polyisocyanate is hexamethylene diisocyanate or isophorone diisocyanate.

[0016] Furthermore, the adhesive layer comprises the following components by weight: 40-50 parts of thermoplastic acrylic resin and 30-40 parts of a second solvent, wherein the second solvent comprises the following components by weight: 10-20 parts of isophorone and 20-30 parts of trimethylbenzene.

[0017] Furthermore, the thermoplastic acrylic resin is selected from Allnex SETALUX 2127 XX-60 or a self-made thermoplastic acrylic resin.

[0018] Furthermore, when the thermoplastic acrylic resin is selected from Allnex SETALUX 2127 XX-60, the adhesive layer further includes the following component by weight: 10-20 parts of filler. The filler is calcium carbonate.

[0019] Furthermore, the self-made thermoplastic acrylic resin comprises the following components in parts by weight: 9-11 parts methyl methacrylate, 8-12 parts styrene, 12-20 parts butyl acrylate, 3-8 parts acrylic acid, 2-3 parts hydroxyethyl methacrylate, 2-7 parts vinyltriethoxysilane-modified silica complex, 48-50 parts toluene, and 1-2 parts azobisisobutyronitrile initiator.

[0020] The thermoplastic acrylic resin of this invention, by controlling the monomer ratios of methyl methacrylate hard monomer, styrene hard monomer, and butyl acrylate soft monomer, achieves both a certain degree of hardness and good flexibility, solving the problems of ordinary thermoplastic resins being either too hard and brittle or too soft and sticky. Furthermore, the carboxyl groups of acrylic acid, the hydroxyl groups of hydroxyethyl methacrylate, and the silicon-oxygen bonds of the vinyltriethoxysilane-modified silica composite can form hydrogen bonds with the white underlayer and polar adsorption with the injection molding substrate, significantly improving interlayer adhesion and avoiding the risk of delamination during thermoforming or injection molding. The combination of methyl methacrylate hard monomer and styrene hard monomer, along with SiO2 filling, ensures that the resin does not decompose or yellow at injection molding temperatures. Moreover, the vinyltriethoxysilane-modified silica composite also improves the weather resistance of the adhesive layer.

[0021] Furthermore, the preparation method of the vinyltriethoxysilane-modified silica composite includes the following steps: A1. Add nano-silica particles to anhydrous ethanol and ultrasonically disperse for 40-60 minutes to form a stable suspension. Then add silica sol and mix evenly to obtain a silica composite. A2. Dissolve vinyltriethoxysilane in anhydrous ethanol, then slowly add deionized water to obtain vinyltriethoxysilane hydrolysate. A3. Under nitrogen protection, the vinyltriethoxysilane hydrolysate is added dropwise to the silica complex, and the mixture is magnetically stirred until homogeneous. The reaction is carried out at 50-70℃ for 1-2 hours. A4. After the reaction is complete, the precipitate is separated by centrifugation, washed with anhydrous ethanol, and then placed in an oven at 50-60℃ for vacuum drying for 2-3 hours to obtain vinyltriethoxysilane modified silica composite.

[0022] Furthermore, in step A1, the nano-silica particles are hydrophilic nano-silica particles with a particle size of 5-9 nm and a mass ratio of nano-silica particles to silica sol of 2-4:1.

[0023] Furthermore, in step A2, the amount of vinyltriethoxysilane added is 8-12% of the total mass of the nano-silica particles and silica sol, the volume ratio of vinyltriethoxysilane to anhydrous ethanol is 1:3-5, and the amount of deionized water added is 1-2 times the molar amount of vinyltriethoxysilane.

[0024] The vinyltriethoxysilane-modified silica composite of the present invention is prepared by nano-silica particles, silica sol, and vinyltriethoxysilane. In the vinyltriethoxysilane, the ethoxy groups of the silane undergo hydrolysis and condense with the hydroxyl groups of the nano-silica particles and silica sol, exposing the vinyl double bonds on the surface. These bonds can then copolymerize with acrylic resin monomers, forming a chemical bond rather than a physical filler, thus solving the compatibility problem between inorganic fillers and organic resins. When the thermoplastic acrylic resin melts, the silicon-oxygen bonds of the vinyltriethoxysilane-modified silica composite can adsorb onto the polar groups of the injection molding substrate, improving the hot melt adhesion strength and preventing delamination during thermoforming or injection molding.

[0025] Furthermore, the preparation method of the self-made thermoplastic acrylic resin includes the following steps: B1. Add toluene solvent to the reaction vessel, then purge the air inside the vessel with nitrogen gas, and heat to 90-100℃; B2. Add the vinyltriethoxysilane-modified silica complex to toluene, disperse it at high speed for 25-35 min, and then sonicate it for 15-25 min to ensure that the vinyltriethoxysilane-modified silica complex is uniformly dispersed in toluene. Then add the monomers methyl methacrylate, styrene, butyl acrylate, acrylic acid, hydroxyethyl methacrylate and part of azobisisobutyronitrile initiator and stir until uniform to obtain a mixture. B3. The mixture is dripped into the reactor from the high-level tank over a period of 4-5 hours. The reaction temperature is 90-100℃. After dripping, the mixture is kept at this temperature for 1.8-2.2 hours. A sample is taken to test the acidity. If the acid value is ≤10 mgKOH / g, the remaining azobisisobutyronitrile initiator and toluene solvent are added to the high-level tank. The mixture is kept at this temperature in the reactor for 3-4 hours to allow the residual acrylic acid monomer to react more fully. B4. Adjust the resin viscosity to 200-280 s / Ford-4 cup at 25℃ to obtain the self-made thermoplastic acrylic resin.

[0026] Furthermore, the mass ratio of the amount of azobisisobutyronitrile initiator added in step B2 to the amount of azobisisobutyronitrile initiator added in step B3 is 6-8:3.

[0027] The present invention also provides a method for preparing the above-mentioned film material for IMD injection molding, comprising the following steps: S1. Image printing: Ink is printed on a carrier layer. After the ink cures, a pattern is formed on the carrier layer, resulting in an ink layer. S2. White base printing: The white base is printed on the ink layer by screen printing and heated at 70-80℃ for 5-10 minutes to obtain the white base layer. S3. Adhesive coating: The adhesive is applied to the white base layer by screen printing and heated at 65-75℃ for 5-10 minutes to obtain the adhesive layer. S4. Die-cutting: Cut or punch according to the dimensions of the product and the design requirements for the diaphragm.

[0028] The method for preparing the film material for IMD injection molding according to the present invention is simple, easy to operate and control, and conducive to large-scale industrial production. The film material for IMD injection molding can be applied to the field of toy car shells.

[0029] The present invention also provides an IMD injection molding method using the above-described membrane material, comprising the following steps: F1. Place the film material inside the mold cavity and position it on the inner surface of the mold cavity, with the adhesive layer of the film material facing inwards from the mold cavity, and close the mold. F2. Melt the ABS resin in the melting section of the injection molding machine at a temperature of 190-220℃, maintain the mold temperature at 75-85℃, and inject the molten ABS resin into the mold cavity through the hot runner. The injection pressure is 100-140Mpa, and the holding pressure is 40-80Mpa. After fusing the film material and ABS resin in the mold cavity, cool until set, demold, and obtain the IMD product.

[0030] The IMD injection molding method of the present invention is simple in process, easy to operate and control, conducive to large-scale industrial production, and produces products with stable quality. The beneficial effects of this invention are as follows: 1. The film material used in IMD injection molding of the present invention comprises, from the outside to the inside, a carrier layer, an ink layer, a white underlayer, and an adhesive layer. The carrier layer is mainly composed of PET and PC. Among them, PET film has excellent printability, dimensional stability, and cost advantages, while PC film has better impact resistance and high temperature resistance, and can be adapted to more demanding application scenarios. The white underlayer is used to enhance the color performance and opacity of the ink layer. The adhesive layer is used to achieve a tight bond between the film material and the injection molding substrate, which can improve the product's resistance to boiling water, resistance to dry and wet aging, and tensile strength.

[0031] 2. The white underlayer of the present invention is prepared by hydroxyl acrylic resin, polyester resin, first solvent, titanium dioxide and curing agent, and has high coverage, high adhesion, heat resistance and injection molding fusion stability.

[0032] 3. The preparation method of the film material for IMD injection molding and the IMD injection molding method using the film material of the present invention are simple, easy to operate and control, which is conducive to large-scale industrial production. The IMD products obtained are of stable quality and have excellent comprehensive performance. Attached Figure Description

[0033] Figure 1 This is a product diagram of the IMD (Integrated Device) of the present invention. Detailed Implementation

[0034] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments. The content mentioned in the embodiments is not intended to limit the present invention.

[0035] Example 1 In this embodiment, the film material used for IMD injection molding includes a carrier layer, an ink layer on the inner side of the carrier layer, a white underlayer on the inner side of the ink layer, and an adhesive layer on the inner side of the white underlayer.

[0036] Furthermore, the carrier layer is a PET sheet.

[0037] Furthermore, the ink layer is a UV ink layer, prepared using existing UV inks.

[0038] Furthermore, the white underlayer comprises the following components in parts by weight: 45 parts hydroxy acrylic resin, 20 parts polyester resin, 65 parts first solvent, 10 parts titanium dioxide, and 70 parts curing agent.

[0039] Furthermore, the hydroxyl acrylic resin is selected from BASF Joncryl 587. The polyester resin is PE-8043 from the Hemings Dechian PE series.

[0040] Furthermore, the first solvent comprises the following components in parts by weight: 45 parts isophorone and 20 parts trimethylbenzene.

[0041] Furthermore, the curing agent is hexamethylene diisocyanate.

[0042] Furthermore, the adhesive layer comprises the following components in parts by weight: 45 parts thermoplastic acrylic resin, 35 parts second solvent, and 15 parts filler. The second solvent comprises the following components in parts by weight: 15 parts isophorone and 25 parts trimethylbenzene, and the filler is calcium carbonate.

[0043] Furthermore, the thermoplastic acrylic resin is selected from Allnex SETALUX 2127 XX-60.

[0044] This embodiment also provides a method for preparing the above-mentioned film material for IMD injection molding, comprising the following steps: S1. Image printing: Ink is printed on a carrier layer. After the ink cures, a pattern is formed on the carrier layer, resulting in an ink layer. S2. White background printing: The white background is printed on the ink layer by screen printing and heated at 75°C for 8 minutes to obtain the white base layer. S3. Adhesive coating: The adhesive is coated onto the white base layer by screen printing and heated at 70°C for 7 minutes to obtain the adhesive layer. S4. Die-cutting: Cut or punch according to the dimensions of the product and the design requirements for the diaphragm.

[0045] This embodiment also provides an IMD injection molding method using the above-mentioned film material, including the following steps: F1. Place the film material inside the mold cavity and position it on the inner surface of the mold cavity, with the adhesive layer of the film material facing inwards from the mold cavity, and close the mold. F2. Melt the ABS resin in the melting section of the injection molding machine at a controlled temperature of 200℃, maintain the mold temperature at 80℃, and inject the molten ABS resin into the mold cavity through the hot runner. The injection pressure is 100Mpa, and the holding pressure is 50Mpa. After fusing the film material and ABS resin in the mold cavity, cool it until it sets, demold, and obtain the IMD product.

[0046] Example 2 In this embodiment, the adhesive layer comprises the following components by weight: 47 parts of thermoplastic acrylic resin and 32 parts of a second solvent, wherein the second solvent comprises the following components by weight: 15 parts of isophorone and 25 parts of trimethylbenzene.

[0047] Furthermore, the thermoplastic acrylic resin is selected from self-made thermoplastic acrylic resins.

[0048] Furthermore, the self-made thermoplastic acrylic resin comprises the following components in parts by weight: 10 parts methyl methacrylate, 8 parts styrene, 17 parts butyl acrylate, 5 parts acrylic acid, 3 parts hydroxyethyl methacrylate, 5 parts vinyltriethoxysilane-modified silica complex, 50 parts toluene, and 2 parts azobisisobutyronitrile initiator.

[0049] Furthermore, the preparation method of the vinyltriethoxysilane-modified silica composite includes the following steps: A1. Add nano-silica particles to anhydrous ethanol, ultrasonically disperse for 50 min to form a stable suspension, then add silica sol and mix evenly to obtain a silica composite. A2. Dissolve vinyltriethoxysilane in anhydrous ethanol, then slowly add deionized water to obtain vinyltriethoxysilane hydrolysate. A3. Under nitrogen protection, the vinyltriethoxysilane hydrolysate was added dropwise to the silica complex, and the mixture was magnetically stirred until homogeneous. The reaction was carried out at 60°C for 1.5 h. A4. After the reaction was completed, the precipitate was separated by centrifugation, washed with anhydrous ethanol, and then placed in an oven at 55°C for vacuum drying for 2.5 h to obtain vinyltriethoxysilane modified silica composite.

[0050] Furthermore, in step A1, the nano-silica particles are hydrophilic nano-silica particles with a particle size of 8 nm, and the mass ratio of the nano-silica particles to the silica sol is 3:1.

[0051] Furthermore, in step A2, the amount of vinyltriethoxysilane added is 10% of the total mass of the nano-silica particles and silica sol, the volume ratio of vinyltriethoxysilane to anhydrous ethanol is 1:4, and the amount of deionized water added is twice the molar amount of vinyltriethoxysilane.

[0052] Furthermore, the silica sol is selected from LEVASILWV33, manufactured by Shanghai Haiyi Science & Trade Co., Ltd.

[0053] Furthermore, the preparation method of the self-made thermoplastic acrylic resin includes the following steps: B1. Add toluene solvent to the reaction vessel, then purge the air inside the vessel with nitrogen gas and heat to 95°C; B2. Add the vinyltriethoxysilane-modified silica complex to toluene, disperse it at high speed for 30 min, and then sonicate it for 20 min to ensure that the vinyltriethoxysilane-modified silica complex is uniformly dispersed in toluene. Then add the monomers methyl methacrylate, styrene, butyl acrylate, acrylic acid, hydroxyethyl methacrylate and part of azobisisobutyronitrile initiator and stir until uniform to obtain a mixture. B3. The mixture is dripped into the reactor from the high-level tank over a period of 4 hours. The reaction temperature is 95℃. After dripping, the mixture is kept at this temperature for 2 hours. A sample is taken to test the acid. If the acid value is ≤10 mgKOH / g, the remaining azobisisobutyronitrile initiator and toluene solvent are added to the high-level tank. The mixture is kept at this temperature for 3 hours to allow the residual acrylic acid monomer to react more fully. B4. Adjust the resin viscosity to 200-280 s / Ford-4 cup at 25℃ to obtain the self-made thermoplastic acrylic resin.

[0054] Furthermore, the mass ratio of the amount of azobisisobutyronitrile initiator added in step B2 to the amount of azobisisobutyronitrile initiator added in step B3 is 7:3.

[0055] This embodiment also provides a method for preparing the above-mentioned film material for IMD injection molding, comprising the following steps: S1. Image printing: Ink is printed on a carrier layer. After the ink cures, a pattern is formed on the carrier layer, resulting in an ink layer. S2. White background printing: The white background is printed on the ink layer by screen printing and heated at 75°C for 8 minutes to obtain the white base layer. S3. Adhesive coating: The adhesive is coated onto the white base layer by screen printing and heated at 72°C for 6 minutes to obtain the adhesive layer. S4. Die-cutting: Cut or punch according to the dimensions of the product and the design requirements for the diaphragm.

[0056] This embodiment also provides an IMD injection molding method using the above-mentioned film material, including the following steps: F1. Place the film material inside the mold cavity and position it on the inner surface of the mold cavity, with the adhesive layer of the film material facing inwards from the mold cavity, and close the mold. F2. Melt the ABS resin in the melting section of the injection molding machine at a controlled temperature of 200℃, maintain the mold temperature at 80℃, and inject the molten ABS resin into the mold cavity through the hot runner. The injection pressure is 100Mpa, and the holding pressure is 50Mpa. After fusing the film material and ABS resin in the mold cavity, cool it until it sets, demold, and obtain the IMD product.

[0057] The rest of this embodiment is the same as that in Embodiment 1.

[0058] Comparative Example 1 The difference between this comparative example and Example 2 is that an equal amount of hydroxyethyl methacrylate is used to replace the vinyltriethoxysilane-modified silica composite.

[0059] Comparative Example 2 The difference between this comparative example and Example 2 is that an equal amount of nano-silica particles are used instead of silica sol.

[0060] Performance testing The performance of the IMD products prepared in Examples 1-2 and Comparative Examples 1-2 was tested. The tensile strength of the IMD products, as well as the adhesion, water resistance, and wet and dry aging properties of the adhesive layer, were tested. The test data are shown in Table 1 below: Table 1

[0061] Adhesion test: The adhesion of the adhesive layer to the injection molding material (ABS resin) was tested according to GB / T 9286—2021, and the cross-cut test was used to test the sample.

[0062] Tensile strength test: Test the tensile strength of IMD products according to GB / T 1040.2-2022.

[0063] Dry and wet aging performance test: (1) Cut the IMD products prepared in Examples 1-2 and Comparative Examples 1-2 into samples of the same size; (2) Place the samples in a damp heat test chamber and expose them to continuous damp heat under the set dry and wet cycle conditions. Each cycle includes 12 hours of damp heat exposure (set temperature is 65°C and humidity is 85%RH) and 12 hours of drying (set temperature is 25°C and humidity is 45%RH); (3) Take out the samples after 6 cycles and perform the above adhesion test.

[0064] Water resistance test: The sample was boiled in deionized water at 80℃ for 2 hours, and then the adhesion test was performed after cooling.

[0065] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A film material for IMD injection molding, characterized in that: It includes a carrier layer, an ink layer on the inner side of the carrier layer, a white underlayer on the inner side of the ink layer, and an adhesive layer on the inner side of the white underlayer.

2. The film material for IMD injection molding according to claim 1, characterized in that: The carrier layer is a PET sheet or a PC sheet.

3. The film material for IMD injection molding according to claim 1, characterized in that: The ink layer is a UV ink layer.

4. The membrane material for IMD injection molding according to claim 1, characterized in that: The white underlayer comprises the following components by weight: 40-50 parts of hydroxyl acrylic resin, 15-25 parts of polyester resin, 60-70 parts of the first solvent, 8-12 parts of titanium dioxide, and 65-75 parts of curing agent.

5. The film material for IMD injection molding according to claim 4, characterized in that: The first solvent comprises the following components in parts by weight: 40-50 parts of isophorone and 15-25 parts of trimethylbenzene.

6. The film material for IMD injection molding according to claim 4, characterized in that: The curing agent is an aliphatic polyisocyanate; the aliphatic polyisocyanate is hexamethylene diisocyanate or isophorone diisocyanate.

7. The membrane material for IMD injection molding according to claim 1, characterized in that: The adhesive layer comprises the following components by weight: 40-50 parts of thermoplastic acrylic resin and 30-40 parts of a second solvent, wherein the second solvent comprises the following components by weight: 10-20 parts of isophorone and 20-30 parts of trimethylbenzene.

8. The film material for IMD injection molding according to claim 7, characterized in that: The adhesive layer also includes the following components by weight: 10-20 parts of filler.

9. A method for preparing a film material for IMD injection molding as described in any one of claims 1-8, characterized in that: Includes the following steps: S1. Image printing: Ink is printed on a carrier layer. After the ink cures, a pattern is formed on the carrier layer, resulting in an ink layer. S2. White base printing: The white base is printed on the ink layer by screen printing and heated at 70-80℃ for 5-10 minutes to obtain the white base layer. S3. Adhesive coating: The adhesive is applied to the white base layer by screen printing and heated at 65-75℃ for 5-10 minutes to obtain the adhesive layer. S4. Die-cutting: Cut or punch according to the dimensions of the product and the design requirements for the diaphragm.

10. An IMD injection molding method using the membrane material according to any one of claims 1-8, characterized in that, Includes the following steps: F1. Place the film material inside the mold cavity and position it on the inner surface of the mold cavity, with the adhesive layer of the film material facing inwards from the mold cavity, and close the mold. F2. Melt the ABS resin in the melting section of the injection molding machine at a temperature of 190-220℃, maintain the mold temperature at 75-85℃, and inject the molten ABS resin into the mold cavity through the hot runner. The injection pressure is 100-140Mpa, and the holding pressure is 40-80Mpa. After fusing the film material and ABS resin in the mold cavity, cool until set, demold, and obtain the IMD product.

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