In-mold transfer printing release film with frosted effect and preparation method thereof

Abstract

The invention relates to an in-mold transfer printing release film with a frosted effect and a preparation method thereof.The release film comprises an antistatic layer, a base material layer, a frosted release layer and a hardened layer, and the frosted release layer is made of frosted release liquid; the frosted release liquid comprises the following components in parts by weight: 10-15 parts of first resin, 3-5 parts of frosted powder, 2-3 parts of a curing agent and 5-8 parts of a second solvent. Compared with the prior art, the surface of the hardened layer has the frosted texture.

Description

Technical Field

[0001] The present invention belongs to the technical field of in-mold transfer printing, and relates to an in-mold transfer release film with a matte effect and a preparation method thereof. Background Art

[0002] In the field of surface decoration of 3C products and automotive interior products, the in-mold transfer (IMR) process has occupied a significant market share. Considering various factors such as comprehensive cost, product production cycle, and performance, the overall advantages of in-mold transfer products are relatively obvious. The market also anticipates more novel and special in-mold transfer products. Matte in-mold transfer products with a slight tactile sensation are exactly what the current market demands.

[0003] During the implementation of the in-mold transfer process, the release film needs to be coated, printed, and injection-molded, involving a long film travel. The film travel of the roll material is extremely prone to generating static electricity, which adsorbs dust and forms dirt spots.

[0004] Patent CN114801538A proposes an in-mold transfer film sheet with a metal coating and a UV texture layer, as well as a preparation method and application thereof. This patent details the preparation steps and layer structures of the in-mold transfer film sheet. However, this patent mainly achieves a metallic feel and other texture effects by increasing the coating structure, and it is difficult to achieve the adhesion required for mass-produced products.

[0005] Patent CN118144394A discloses a release film, a preparation method, and an application thereof. However, this patent is mainly applied to the production of flexible printed circuit boards. Compared with the in-mold transfer field, flexible printed circuit boards have relatively low requirements for multiple properties such as stretchability and hardness, and this patent cannot be applied to the in-mold transfer process.

[0006] Patent CN117325574A discloses a high-stretch 3D out-of-mold forming transfer film sheet and a preparation method thereof. The layered structure of the prepared transfer film sheet body from bottom to top is successively a base film layer, a release layer, a texture layer, a hardening layer, a pattern printing layer, an adhesive layer, and a release film. Dissolve OP wax in any one or any combination of mixed solvents of xylene, S-150, toluene, n-heptane, and methylcyclohexane to form a release agent, coat the release agent on the upper surface of the base film layer, and dry it with hot air to form a release layer. The texture layer is hot-pressed on the surface of the release layer using a hot pressing roller. The components of the hardening solution include acrylic resin, polyurethane acrylate prepolymer, photocurable monomer, nano wear-resistant material, ultraviolet absorber, photoinitiator, antioxidant, dispersant, and mixed solvent to form a hardening solution. After the hardening solution hardens, a hardening layer is formed, and the hardening layer is laminated on the upper surface of the texture layer. However, this patent can only be applied to the out-of-mold transfer process, and its adhesion is far inferior to that of in-mold transfer, unable to meet the requirements of general 3C products.

[0007] Patent CN112318989A discloses an online coated ABC structure BOPET single-sided matte antistatic film, which includes three ABC layers arranged in sequence. The A layer is an antibacterial and flame-retardant layer, the B layer is an intermediate core layer, and the C layer is a matte layer. An antistatic liquid is coated on the matte surface, and the matte layer is a PET / core-shell carbon microsphere composite material. However, there is no release structure in this patent, which is not applicable to the field of in-mold transfer. Summary of the Invention

[0008] The purpose of the present invention is to overcome at least one defect of the above-mentioned existing technologies, and to provide a matte in-mold transfer release film and its preparation method. The present invention gives the surface of the hardening layer a matte texture.

[0009] The purpose of the present invention can be achieved by the following technical solutions:

[0010] One of the technical solutions of the present invention is to provide a matte in-mold transfer release film, which includes an antistatic layer, a substrate layer, a matte release layer, and a hardening layer. The material of the matte release layer is a matte release liquid, and the matte release liquid includes the following components in parts by weight:

[0011] 10 - 15 parts of a first resin, 3 - 5 parts of matte powder, 2 - 3 parts of a curing agent, and 5 - 8 parts of a second solvent.

[0012] Generally, a protective film is attached or an antistatic layer is coated to prevent the generation of static electricity. However, the cost of a high-temperature resistant and tightly attached protective film is too high. The present invention selects to coat an antistatic layer to protect the substrate layer. The antistatic agent coated on the antistatic layer is an externally applied antistatic agent. Externally applied antistatic agents are divided into anionic antistatic agents, cationic antistatic agents, and amphoteric antistatic agents. Anionic antistatic agents may interact with other additives on the surface of the product at high temperatures, resulting in whitening. Cationic antistatic agents may decompose and become inactive at high temperatures, and even produce toxicity or irritation. Amphoteric antistatic agents are more suitable.

[0013] Furthermore, the material of the antistatic layer is an antistatic liquid, which includes an antistatic agent and a first solvent. The antistatic agent is selected from one or more amphoteric antistatic agents such as alkyl dimethyl carboxymethyl ammonium ethylene lactone, dodecyl dimethyl quaternary ethylene lactone, and quaternary ammonium carboxylate lactone. The first solvent is selected from one or more of ethanol, isopropanol, and ethylene glycol. The concentration of the antistatic liquid is 0.5 - 2%, and the thickness of the antistatic layer is 1 - 2 μm.

[0014] Furthermore, the material of the substrate layer is selected from one or more transparent films such as polycarbonate (PC) film, polyethylene terephthalate (PET) film, and polymethyl methacrylate (PMMA) film, and the thickness is 35 - 100 μm.

[0015] As a preferred technical solution, the form of the film is a coil, which is convenient for large-scale coating.

[0016] Further, the first resin is a trifunctional fluorosilicon-modified polyurethane acrylate, which is obtained by modifying polyurethane acrylate with perfluoroalkyl ethyl acrylate and vinyltriethoxysilane, and includes the following steps:

[0017] Mix 100 - 150 parts of polyurethane acrylate emulsion, 20 - 30 parts of perfluoroalkyl ethyl acrylate and 35 - 50 parts of vinyltriethoxysilane, heat, keep warm, add 8 - 10 parts of chain extender for reaction, add 8 - 10 parts of crosslinking agent for reaction, cool down, add 2 - 4 parts of buffer for reaction to control pH, and distill off the solvent under reduced pressure from the reacted solution to obtain a trifunctional fluorosilicon-modified polyurethane acrylate emulsion;

[0018] The heating temperature is 75 - 85 °C, and the heat preservation time is 2.5 - 3.5 h.

[0019] The chain extender is selected from one or more of 1,4-butanediol and hexanediol, and the reaction time for adding the chain extender is 0.3 - 0.7 h.

[0020] The crosslinking agent is selected from one or more of trimethylolpropane and trimethylolethane, and the reaction time for adding the crosslinking agent is 0.3 - 0.7 h.

[0021] The cooling temperature is 35 - 45 °C, the buffer is selected from one or more of triethylamine and triethanolamine, and the reaction time for adding the buffer is 0.3 - 0.7 h.

[0022] As a preferred technical solution, the temperature for reduced pressure distillation is 40 - 60 °C, the vacuum degree is 0.05 - 0.09 MPa, the stirring speed is 50 - 200 rpm, and the time is 1 - 3 h.

[0023] Further, the abrasive powder is selected from one or more of spherical silica powder and polymethyl methacrylate powder, the particle size of the abrasive powder is 5 - 15 μm, the curing agent is selected from one or more of methylated melamine formaldehyde resin, blocked hexamethylene diisocyanate (HDI), and phenylated melamine formaldehyde resin, the second solvent is selected from one or more of cyclohexanone and butanone, and the thickness of the abrasive release layer is 5 - 15 μm.

[0024] As a preferred technical solution, the abrasive powder uses spherical silica powder and polymethyl methacrylate powder, and the mass ratio of the spherical silica powder to the polymethyl methacrylate powder is 1:(1 - 2).

[0025] As a preferred technical solution, the curing agent is a methylated melamine formaldehyde resin, and the methylation degree of the methylated melamine formaldehyde resin is ≥ 5%.

[0026] As a preferred technical solution, the second solvent is cyclohexanone and methyl ethyl ketone, and the mass ratio of cyclohexanone to methyl ethyl ketone is 1:(0.8 - 1.2).

[0027] Due to the presence of the abrasive powder, the thickness of the release layer cannot be too thin, otherwise the abrasive powder particles cannot be completely fixed and there is a risk of falling off; if the release layer is too thick, the abrasive effect on the surface of the hardened layer in contact with the release layer cannot be guaranteed, and the release layer is prone to incomplete curing.

[0028] In the in-mold transfer product, after the substrate layer and the release layer are peeled off, the outermost layer of the product is the hardened layer. In addition, the in-mold transfer product is printed in rolls, and the stretchability of the hardened layer also needs to be ensured. Too high hardness of the hardened layer often affects its stretchability. Therefore, a balance needs to be found between the two.

[0029] Further, the material of the hardened layer is a hardening solution, and the hardening solution comprises the following components in parts by weight:

[0030] 8 - 10 parts of a second resin, 2.5 - 3 parts of a photoinitiator, 1 - 3 parts of a leveling agent, 3 - 5 parts of a third solvent.

[0031] Further, the second resin is an aliphatic polyurethane acrylate oligomer, and the aliphatic polyurethane acrylate oligomer is obtained by polymerizing ethylene glycol cinnamate, an aliphatic diisocyanate, an acrylate and a polyether diol, and comprises the following steps:

[0032] Adding 15 - 30 parts of cinnamoyl chloride to 12 - 25 parts of ethylene glycol, adding 2 - 4 parts of a pH control agent for reaction to obtain ethylene glycol cinnamate, adding 15 - 35 parts of an aliphatic diisocyanate, 5 - 7 parts of a polymerization inhibitor and 2 - 4 parts of a catalyst for reaction, adding 20 - 40 parts of an acrylate and 20 - 35 parts of a polyether diol for reaction, and subjecting the reaction solution to vacuum distillation to remove the solvent to obtain the aliphatic polyurethane acrylate oligomer;

[0033] The pH control agent is selected from one or more of sodium hydroxide and sodium carbonate, the temperature for adding the pH control agent for reaction is 80 - 90 °C, and the time is 2.5 - 3.5 h.

[0034] The aliphatic diisocyanate is selected from one or more of hexamethylene diisocyanate, isophorone diisocyanate (IPDI), and dicyclohexylmethane diisocyanate (HMDI). The inhibitor is selected from one or more of hydroquinone and p-benzoquinone. The catalyst is selected from one or more of dibutyltin dilaurate and triethylamine. The temperature for the reaction of adding the aliphatic diisocyanate, inhibitor, and catalyst is 80 - 90 °C, and the time is 2.5 - 3.5 h.

[0035] The acrylate is selected from one or more of trimethylolpropane triacrylate and perfluoroalkyl ethyl acrylate. The temperature for the reaction of adding the acrylate and polyether diol is 80 - 90 °C, and the time is 2.5 - 3.5 h.

[0036] As a preferred technical solution, the temperature for vacuum distillation is 40 - 60 °C, the vacuum degree is 0.05 - 0.09 MPa, the stirring speed is 50 - 200 rpm, and the time is 1 - 3 h.

[0037] Furthermore, the photoinitiator is selected from one or more of 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl phenylphosphonic acid ethyl ester, and 4-(phenylthio)phenyl diphenyl sulfonium hexafluorophosphate. The leveling agent is selected from one or more of fluorine-modified acrylic leveling agents and phosphate ester-modified acrylic leveling agents. The third solvent is selected from one or more of cyclohexanone and methyl ethyl ketone. The thickness of the hardened layer is 10 - 15 μm.

[0038] As a preferred technical solution, the third solvent uses cyclohexanone and methyl ethyl ketone, and the mass ratio of cyclohexanone to methyl ethyl ketone is 1:(0.8 - 1.2).

[0039] One of the technical solutions of the present invention is to provide a method for preparing the in-mold transfer release film with the frosted effect, and this method includes the following steps:

[0040] S1. Mix the antistatic agent and the first solvent to prepare an antistatic liquid, and coat the antistatic liquid on the substrate layer to form an antistatic layer;

[0041] S2. Mix the first resin, the frosted powder, the curing agent, and the second solvent, grind, and filter to obtain a frosted release liquid. Coat the frosted release liquid on the other side of the substrate layer coated with the antistatic layer, and let it stand to form a frosted release layer;

[0042] S3. Mix the second resin, the photoinitiator, the leveling agent, and the third solvent, filter to obtain a hardening liquid, coat the hardening liquid on the frosted release layer, and let it stand to form a hardened layer, thus obtaining the in-mold transfer release film with the frosted effect.

[0043] As a preferred technical solution, dust removal is carried out before coating the base material layer in step S1.

[0044] As a preferred technical solution, the antistatic liquid is coated on the non-printing surface of the base material layer in step S1.

[0045] Furthermore, in step S1, the roll coating speed is 5 - 15 m / min, and the temperature is 15 - 35 °C;

[0046] In step S2, it is ground to less than 15 μm, and the mesh number of filtration is 300 - 400 meshes.

[0047] The coating tension is 15 - 25 N, the pressure of the pressure roller is 0.1 - 0.15 MPa, the speed is 5 - 10 m / min, and the oven temperature is 80 - 90 °C.

[0048] The placement temperature is 40 - 60 °C, and the time is 18 - 24 h;

[0049] In step S3, the mesh number of filtration is 400 - 500 meshes.

[0050] The UV lamp intensity of coating is 750 - 1500 mW / cm 2 , and the film running speed is 3 - 5 m / min.

[0051] The placement temperature is 40 - 60 °C, and the time is 18 - 24 h.

[0052] One of the technical solutions of the present invention lies in providing an application of the in-mold transfer release film with the matte effect. When the release film is used, it can be directly printed on the release surface. After the pattern layer and the glue layer are printed, the pattern layer is cured according to the corresponding ink curing conditions. After curing, injection molding can be carried out.

[0053] As a preferred technical solution, the printing method is selected from one or more of screen printing, gravure printing, offset printing, and digital printing.

[0054] The matte release film in the present invention is transparent before the release layer is peeled off, which is convenient for color matching during the printing process. After injection molding is completed, the base material layer and the release layer of the release film are peeled off, and the matte effect on the surface of the hardening layer is transferred to the surface of the plastic product.

[0055] The surface roughness of the hardening layer after the release film is transferred is 1 - 2.8 μm.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] (1) In the present invention, by adding abrasive powder, the release surface is transformed into a matte surface; the subsequently coated hardening layer resin is tightly combined with the release layer. After printing and injection molding, the substrate and the release layer are peeled off, and the matte texture and slight touch on the surface of the hardening layer are presented on the product surface;

[0058] (2) Among the resins used for the matte release layer of the present invention, polyurethane acrylate has good tensile properties, which can make up for the decline in tensile properties caused by adding abrasive powder; after being modified by fluorosilicon, its release performance has been qualitatively improved; the F element has a large electronegativity and a low polarizability, which can reduce the peeling force of the release layer and reduce release residue; in addition, the bond energies of both C-F and Si-O-Si are greater than that of C-C, which can effectively improve the thermal stability of polyurethane acrylate; the fluorine chain in perfluoroalkyl ethyl acrylate reduces the surface energy and lessens release residue; while the Si-O-Si provided by vinyltriethoxysilane improves the stability of the release layer and prevents the peeling force from being too small and the coating from being too easy to fall off;

[0059] (3) The resin used for the hardening layer of the present invention, namely aliphatic polyurethane acrylate oligomer, has excellent flexibility, wear resistance and weather resistance, and at the same time has high transparency and good optical properties; in addition, the aliphatic polyurethane acrylate oligomer has good adhesion to common inks, and there is no need to additionally coat an ink connection layer;

[0060] (4) The functional layers of the present invention are stacked in sequence, and the overall production process does not need to be realized with high energy consumption or high cost, which is a low-cost innovative solution. Brief Description of the Drawings

[0061] Figure 1 It is a schematic structural diagram of the in-mold transfer release film with a matte effect in the embodiment of the present invention.

[0062] Explanation of the marks in the figure:

[0063] 1 - Antistatic layer, 2 - Substrate layer, 3 - Matte release layer, 4 - Hardening layer. Detailed Embodiments

[0064] The present invention will be described in detail below in conjunction with specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation manners and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0065] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third", etc. are used to describe common objects, and only represent different instances referring to the same object, rather than implying that the objects so described must be in a given order, whether in terms of time, space, sorting or any other way.

[0066] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0067] Unless otherwise specified, the equipment used in the following embodiments represents conventional equipment in the art; unless otherwise specified, the reagents used represent commercially available products or are prepared by conventional methods in the art. Those not described in detail in the following embodiments can be achieved by conventional experimental means in the art.

[0068] Example 1:

[0069] An in-mold transfer release film with a frosted effect, as Figure 1 shown, includes an antistatic layer 1, a substrate layer 2, a frosted release layer 3, and a hardening layer 4;

[0070] The material of the antistatic layer 1 is selected as an antistatic liquid, and the antistatic liquid includes 0.1 kg of alkyl dimethyl carboxymethyl ammonium betaine of Xinying Chemical Industry BS-12 type and 9.9 kg of ethanol. The concentration of the antistatic liquid is 1%, and the thickness of the antistatic layer 1 is 1 μm;

[0071] The material of the substrate layer 2 is selected as a roll-form, transparent polyethylene terephthalate (PET) film of Helekai FG2 type, with a thickness of 50 μm;

[0072] The material of the frosted release layer 3 is selected as a frosted release liquid, and the frosted release liquid includes the following components in parts by weight:

[0073] 10 kg of trifunctional fluorosilicon-modified polyurethane acrylate, 1.5 kg of spherical silica powder from Jiangsu Lianrui, 1.5 kg of polymethyl methacrylate (PMMA) powder of Sumitomo G5065 type from Japan, 2 kg of methylated melamine formaldehyde resin of Tangyi HBX-9303 type, 2.5 kg of cyclohexanone and 2.5 kg of butanone;

[0074] The purity of the spherical silica powder is 99%, the average particle size is 5 μm, the purity of the polymethyl methacrylate powder is 99%, the average particle size is 5 μm, and the methylation degree of the methylated melamine formaldehyde resin is 10%;

[0075] The trifunctional fluorosilicon-modified polyurethane acrylate is obtained by modifying polyurethane acrylate with perfluoroalkyl ethyl acrylate and vinyl triethoxysilane. The specific steps are as follows:

[0076] Mix 125 parts of polyurethane acrylate emulsion of Tangyi ACR-S6178 type, 25 parts of perfluoroalkyl ethyl acrylate of Shineng, and 40 parts of vinyl triethoxysilane of Nanjing Xuanhao KH-151 type of silane coupling agent, heat to 80 °C, keep warm for 3 h, add 9 parts of 1,4-butanediol and react for 0.5 h, add 9 parts of trimethylolpropane of Shandong Huibang and react for 0.5 h, cool down to 40 °C, add 3 parts of triethylamine and react for 0.5 h to control the pH. The reaction solution is distilled under reduced pressure for 2 h at a temperature of 50 °C, a vacuum degree of 0.07 MPa, and a stirring speed of 120 rpm to remove the solvent, obtaining trifunctional fluorosilicon-modified polyurethane acrylate emulsion;

[0077] The thickness of the matte release layer 3 is 7 μm;

[0078] The material of the hardening layer 4 is selected as a hardening solution, and the hardening solution includes the following components in parts by weight:

[0079] 8 kg of aliphatic polyurethane acrylate oligomer, 2.5 kg of 1-hydroxycyclohexyl phenyl ketone of Huaxiang Kejie, 1 kg of fluorine-modified acrylic leveling agent of Tangyi EFKA3777 type, 1.5 kg of cyclohexanone and 1.5 kg of butanone,

[0080] The aliphatic polyurethane acrylate oligomer is obtained by polymerizing ethylene glycol cinnamate, aliphatic diisocyanate, acrylate and polyether diol. The specific steps are as follows:

[0081] 16 parts of cinnamoyl chloride of the Lisheng LS5263987-42 type were added to 15 parts of ethylene glycol, and 3 parts of sodium hydroxide were added. The reaction was carried out at 85 °C for 3 h to obtain ethylene glycol cinnamate. Then, 18 parts of hexamethylene diisocyanate (HDI) of the Covestro N3390 type, 6 parts of hydroquinone, and 3 parts of triethylamine were added, and the reaction was carried out at 85 °C for 3 h. Next, 24 parts of trimethylolpropane triacrylate of the Yunbang YB31847 type and 23 parts of polyether diol of the Guangzhou Yinghong N210 type were added, and the reaction was carried out at 85 °C for 3 h. The reaction solution was subjected to vacuum distillation at 50 °C, a vacuum degree of 0.07 MPa, and a stirring speed of 120 rpm for 2 h at 85 °C to remove the solvent, obtaining an aliphatic polyurethane acrylate oligomer;

[0082] The thickness of the hardened layer 4 is 11 μm.

[0083] The preparation method of the in-mold transfer release film with the above matte effect is as follows:

[0084] S1. 0.1 kg of alkyl dimethylammonium ethyl lactone and 9.9 kg of ethanol were mixed to prepare a 1% antistatic coating solution. The antistatic coating solution was roll-coated on the substrate layer 2 of the transparent polyethylene terephthalate film at a speed of 10 m / min at room temperature of 25 °C to form an antistatic layer 1;

[0085] S2. 10 kg of trifunctional fluorosilicon-modified polyurethane acrylate, 1.5 kg of spherical silica powder, 1.5 kg of polymethyl methacrylate powder, 2 kg of methylated melamine formaldehyde resin, 2.5 kg of cyclohexanone, and 2.5 kg of butanone were mixed and stirred evenly, ground to below 10 μm using a three-roll mill, and filtered through a 380-mesh screen to obtain a matte release coating solution. The matte release coating solution was poured into the coating machine trough and coated on the other side of the substrate layer 2 coated with the antistatic layer 1. The tension of the coating machine was controlled at 20 N, the pressure of the pressure roller was 0.12 MPa, the speed was 7 m / min, and the oven temperature was 85 °C. After coating, the film was loosened and placed at 50 °C for 20 h to form a matte release layer 3;

[0086] S3. The film was taken out and cooled to room temperature, and then a hardening coating solution was coated. 8 kg of aliphatic polyurethane acrylate oligomer, 2.5 kg of 1-hydroxycyclohexyl phenyl ketone, 1 kg of fluorine-modified acrylic leveling agent, 1.5 kg of cyclohexanone, and 1.5 kg of butanone were mixed and stirred evenly, filtered through a 420-mesh screen to obtain a hardening coating solution. The hardening coating solution was poured into the coating machine trough and coated on the matte release layer 3. The UV light intensity was controlled at 1200 mW / cm 2 , the film running speed was 4 m / min. After coating, the film was loosened and placed at 50 °C for 20 h to form a hardened layer 4, obtaining an in-mold transfer release film with a matte effect.

[0087] Example 2:

[0088] An in-mold transfer release film with a matte effect and its preparation method are basically the same as those in Example 1, except that the matte release liquid comprises the following components in parts by weight:

[0089] 11 kg of trifunctional fluorosilicon-modified polyurethane acrylate, 1.5 kg of spherical silica powder, 2 kg of polymethyl methacrylate powder, 2 kg of methylated melamine formaldehyde resin, 3 kg of cyclohexanone, and 3 kg of butanone.

[0090] Example 3:

[0091] An in-mold transfer release film with a matte effect and its preparation method are basically the same as those in Example 1, except that the matte release liquid comprises the following components in parts by weight:

[0092] 13 kg of trifunctional fluorosilicon-modified polyurethane acrylate, 2 kg of spherical silica powder, 2 kg of polymethyl methacrylate powder, 2.5 kg of methylated melamine formaldehyde resin, 3 kg of cyclohexanone, and 3 kg of butanone;

[0093] The hardening liquid comprises the following components in parts by weight:

[0094] 10 kg of aliphatic polyurethane acrylate oligomer, 3 kg of 1-hydroxycyclohexyl phenyl ketone, 2 kg of fluorine-modified acrylic leveling agent, 2.5 kg of cyclohexanone, and 2.5 kg of butanone.

[0095] Example 4:

[0096] An in-mold transfer release film with a matte effect and its preparation method are basically the same as those in Example 1, except that the matte release liquid comprises the following components in parts by weight:

[0097] 12 kg of trifunctional fluorosilicon-modified polyurethane acrylate, 2.5 kg of spherical silica powder, 2.5 kg of polymethyl methacrylate powder, 2.5 kg of methylated melamine formaldehyde resin, 3 kg of cyclohexanone, and 3 kg of butanone;

[0098] The hardening liquid comprises the following components in parts by weight:

[0099] 9 kg of aliphatic polyurethane acrylate oligomer, 2.5 kg of 1-hydroxycyclohexyl phenyl ketone, 2 kg of fluorine-modified acrylic leveling agent, 2 kg of cyclohexanone, and 2 kg of butanone.

[0100] Comparative example:

[0101] An in-mold transfer release film with a matte effect and its preparation method are basically the same as those in Example 1, except that the matte release liquid comprises the following components in parts by weight:

[0102] 11 kg of trifunctional fluorosilicon-modified polyurethane acrylate, 3 kg of spherical silica powder, 3 kg of polymethyl methacrylate powder, 2.5 kg of methylated melamine formaldehyde resin, 3 kg of cyclohexanone, and 3 kg of methyl ethyl ketone.

[0103] The above release film is subjected to the following tests or experiments, and then the test or experiment results are analyzed.

[0104] Test example:

[0105] The above release film is tested for boiling water resistance, thermal cycling resistance, rubbing resistance, coating hardness, light transmittance, ultraviolet resistance, acid and alkali resistance, adhesion, organic solvent resistance, surface roughness, peel strength, and surface tension. The test methods are carried out in accordance with "GB / T 17657-2022 Test Methods for Physical and Chemical Properties of Wood-Based Panels and Decorative Wood-Based Panels", "GB / T 31410-2015 Evaluation of Wet Scrubbing Resistance and Cleanability of Coatings on Paints and Varnishes", "GB / T 6739 Paints and Varnishes - Determination of Film Hardness by the Pencil Method", "GB / T 2410-2008 Determination of Light Transmittance and Haze of Transparent Plastics", "GB / T 16422.2-2014 Plastics - Methods of Exposure to Laboratory Light Sources - Part 2: Xenon-Arc Lamp", "GB / T 9274-1988 Paints and Varnishes - Determination of Resistance to Liquid Media", "GB / T 9286-1998 Cross-Cut Test Method for Testing Adhesion Strength of Paint Films", "GB / T 23989-2009 Determination Method for Solvent Rubbing Resistance of Coatings", "GB / T 1031-2009 Surface Texture - Profile Method - Surface Roughness Parameters and Their Values", "FZ / T 01010-2012 Determination of Coating Peel Strength of Coated Fabrics", and "GB / T 14216-2008 Determination of Surface Tension of Paints and Varnishes". The test results are shown in Table 1.

[0106] Table 1 Test Results of Examples and Comparative Examples

[0107] Test item Example 1 Example 2 Example 3 Example 4 Comparative example Boiling water resistance Qualified Qualified Qualified Qualified Qualified Thermal shock resistance Qualified Qualified Qualified Qualified Qualified Scrub resistance Qualified Qualified Qualified Qualified Qualified Coating hardness 2H 2H 2H 2H 2H Light transmittance 90％ 90％ 90％ 90％ 90％ UV resistance Qualified Qualified Qualified Qualified Qualified Acid and alkali resistance Qualified Qualified Qualified Qualified Qualified Adhesion Qualified Qualified Qualified Qualified Unqualified Organic solvent resistance Qualified Qualified Qualified Qualified Qualified Surface roughness (μm) 1.2～1.4 1.3～1.6 1.5～1.8 2.2～2.5 3～3.5 Peeling force (N / mm) 8 8 7 5 1 Surface tension (dyne) 35～37 35～37 31～33 30～32 24～27

[0108] As shown in Table 1, in Examples 1 to 4, as the proportion of the abrasive powder gradually increases, the abrasive powder particles become denser, and the surface roughness of the final product increases accordingly. However, the peel strength and surface tension of the abrasive release layer 3 also decrease.

[0109] When the proportion of the abrasive powder is too high, as in the comparative example, although the surface roughness is high, the peel strength and surface tension will be too low, and there is a risk of peeling off even with a slight collision of the abrasive release layer 3, which has a greater impact on the appearance, yield, adhesion, etc. of the final product.

[0110] In Examples 1 to 4, changes in the proportion of the hardened layer 4 within the scope of the present invention will not overly affect the coating hardness of the final product, which also leaves a tolerance range for the process conditions of production;

[0111] Generally speaking, the properties of the final product of the present invention, such as boiling water resistance, thermal cycling resistance, rubbing resistance, light transmittance, ultraviolet resistance, acid and alkali resistance, adhesion, organic solvent resistance, peel strength, and surface tension, all meet the process requirements, have a frosted texture and a slight touch feeling, and during the actual production process, the human body does not feel obvious static electricity on the final product.

[0112] The above description of the embodiments is to enable those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative efforts. Therefore, the present invention is not limited to the above embodiments, and all improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. An in-mold transfer release film with a matte effect, characterized in that, The release film includes an antistatic layer (1), a substrate layer (2), a matte release layer (3), and a hardening layer (4). The material of the matte release layer (3) is a matte release liquid, and the matte release liquid includes the following components in parts by weight: 10 - 15 parts of a first resin, 3 - 5 parts of matte powder, 2 - 3 parts of a curing agent, and 5 - 8 parts of a second solvent.

2. The in-mold transfer release film with a matte effect according to claim 1, characterized in that, The material of the antistatic layer (1) is an antistatic liquid, and the antistatic liquid includes an antistatic agent and a first solvent. The antistatic agent is selected from one or more amphoteric antistatic agents such as alkyl dimethyl carboxymethyl ammonium ethylene lactone, dodecyl dimethyl quaternary ethylene lactone, and quaternary ammonium carboxylate lactone. The first solvent is selected from one or more of ethanol, isopropanol, and ethylene glycol. The concentration of the antistatic liquid is 0.5 - 2%, and the thickness of the antistatic layer (1) is 1 - 2 μm.

3. The in-mold transfer release film with a frosted effect according to claim 1, characterized in that: The material of the substrate layer (2) is selected from one or more of a polycarbonate film, a polyethylene terephthalate film, and a polymethyl methacrylate film, and the thickness is 35 - 100 μm.

4. The in-mold transfer release film with a matte effect according to claim 1, characterized in that The first resin is a trifunctional fluorosilicon - modified polyurethane acrylate, and the trifunctional fluorosilicon - modified polyurethane acrylate is obtained by modifying polyurethane acrylate with perfluoroalkyl ethyl acrylate and vinyl triethoxysilane, including the following steps: Mix 100 - 150 parts of polyurethane acrylate emulsion, 20 - 30 parts of perfluoroalkyl ethyl acrylate, and 35 - 50 parts of vinyl triethoxysilane, heat, keep warm, add 8 - 10 parts of a chain extender for reaction, add 8 - 10 parts of a cross - linker for reaction, cool down, and add 2 - 4 parts of a buffer for reaction to obtain a trifunctional fluorosilicon - modified polyurethane acrylate emulsion; The temperature of the heating is 75 - 85 °C, and the time of keeping warm is 2.5 - 3.5 h. The chain extender is selected from one or more of 1,4 - butanediol and hexanediol, and the reaction time for adding the chain extender is 0.3 - 0.7 h. The cross - linker is selected from one or more of trimethylolpropane and trimethylolethane, and the reaction time for adding the cross - linker is 0.3 - 0.7 h. The temperature of the cooling is 35 - 45 °C, the buffer is selected from one or more of triethylamine and triethanolamine, and the reaction time for adding the buffer is 0.3 - 0.7 h.

5. A mold-in-transfer release film with a matte effect according to claim 1, characterized in that, The matte powder is selected from one or more of spherical silica powder and polymethyl methacrylate powder. The particle size of the matte powder is 5 - 15 μm. The curing agent is selected from one or more of methylated melamine formaldehyde resin, blocked hexamethylene diisocyanate, and phenylated melamine formaldehyde resin. The second solvent is selected from one or more of cyclohexanone and butanone. The thickness of the matte release layer (3) is 5 - 15 μm.

6. The in-mold transfer release film with a matte effect according to claim 1, wherein, The material of the hardening layer (4) is a hardening liquid, and the hardening liquid includes the following components in parts by weight: 8 - 10 parts of a second resin, 2.5 - 3 parts of a photoinitiator, 1 - 3 parts of a leveling agent, and 3 - 5 parts of a third solvent.

7. The in-mold transfer release film with a frosted effect according to claim 6, characterized in that: The second resin is an aliphatic polyurethane acrylate oligomer, and the aliphatic polyurethane acrylate oligomer is obtained by polymerizing ethylene glycol cinnamate, aliphatic diisocyanate, acrylate, and polyether diol, including the following steps: 15-30 parts of cinnamoyl chloride are added to 12-25 parts of ethylene glycol, 2-4 parts of pH control agent are added for reaction to obtain ethylene glycol cinnamate, 15-35 parts of aliphatic diisocyanate, 5-7 parts of polymerization inhibitor and 2-4 parts of catalyst are added for reaction, 20-40 parts of acrylate and 20-35 parts of polyether diol are added for reaction to obtain aliphatic polyurethane acrylate oligomer; The pH control agent is selected from one or more of sodium hydroxide and sodium carbonate. The reaction temperature of adding the pH control agent is 80-90°C and the reaction time is 2.5-3.5h. The aliphatic diisocyanate is selected from one or more of hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate; the polymerization inhibitor is selected from one or more of hydroquinone and p-benzoquinone; the catalyst is selected from one or more of dibutyltin dilaurate and triethylamine; the temperature of adding the aliphatic diisocyanate, the polymerization inhibitor and the catalyst to react is 80-90° C. and the reaction time is 2.5-3.5 hours. The acrylate is selected from one or more of trimethylolpropane triacrylate and perfluoroalkylethyl acrylate. The temperature for reacting the acrylate and polyether diol is 80-90° C. and the reaction time is 2.5-3.5 hours.

8. The in-mold transfer release film with a matte effect according to claim 6, characterized in that, The photoinitiator is selected from one or more of 1-hydroxycyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoylphenyl phosphonic acid ethyl ester, and 4-(phenylthio)phenyl diphenylsulfonium hexafluorophosphate; the leveling agent is selected from one or more of fluorine-modified acrylic leveling agents and phosphate-modified acrylic leveling agents; the third solvent is selected from one or more of cyclohexanone and butanone; and the thickness of the hardened layer (4) is 10 to 15 μm.

9. A method for preparing an in-mold transfer release film with a matte effect as described in any one of claims 1 to 8, characterized in that, The method comprises the following steps: S1, mixing an antistatic agent and a first solvent to prepare an antistatic liquid, and coating the antistatic liquid on a substrate layer (2) to form an antistatic layer (1); S2, mixing a first resin, frosting powder, a curing agent, and a second solvent, grinding, filtering, and obtaining a frosting release liquid, coating the frosting release liquid on the other side of the substrate layer (2) coated with the antistatic layer (1), and allowing to stand to form a frosting release layer (3); S3, mixing the second resin, the photoinitiator, the leveling agent and the third solvent, filtering to obtain a hardening liquid, coating the hardening liquid on the frosted release layer (3), and leaving it to form a hardened layer (4), thereby obtaining an in-mold transfer release film with a frosted effect.

10. The preparation method of an in-mold transfer release film with a matte effect according to claim 9, characterized in that, The roller coating speed in step S1 is 5-15 m / min and the temperature is 15-35° C.; In step S2, the particles are ground to a size of less than 15 μm and filtered through a mesh size of 300 to 400. The coating tension is 15-25N, the roller pressure is 0.1-0.15MPa, the speed is 5-10m / min, and the oven temperature is 80-90℃. The storage temperature is 40-60℃ for 18-24 hours; The mesh size of the filtration in step S3 is 400 to 500 meshes. The UV light intensity for coating is 750 - 1500 mW / cm 2 , and the film running speed is 3 - 5 m / min. The storage temperature is 40-60℃ and the storage time is 18-24h.

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