Optical coating process for shoe material TPU transfer printing

Abstract

The invention relates to the technical field of TPU, in particular to an optical coating process for shoe material TPU transfer printing. An optical coating process for shoe material TPU transfer printing comprises the following steps that S1, a texture layer is photoetched on the surface of a PC board, and plasma surface activation treatment is conducted on the texture layer; s2, uniformly coating transfer printing glue on the texture layer to obtain a transfer printing glue layer, placing a TPU sheet on the transfer printing glue layer, and pressing by adopting vacuum hot-pressing laminating equipment to obtain a layered structure; s3, the layered structure is fed into a tunnel furnace, and transfer printing glue is preliminarily cured; and S4, after primary curing, stripping the TPU sheet and the transfer printing glue layer from the texture plate, putting the TPU sheet and the transfer printing glue layer into a tunnel furnace, and carrying out secondary curing on the transfer printing glue to obtain the TPU with the texture structure. The prepared TPU has excellent tensile property, the texture layer has good adhesive force, hydrolysis resistance and aging resistance, and the optical coating layer has good adhesive force and bending resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of TPU, and in particular to an optical coating process for TPU transfer printing of shoe materials. Background Art

[0002] In today's footwear manufacturing industry, TPU, with its exceptional flexibility, wear resistance, and excellent fatigue resistance, is an ideal choice for hot-cut logos and decorative components. It is widely used in a variety of athletic, casual, and fashion shoes. Currently, traditional surface treatment methods for hot-cut logos and decorative components on TPU footwear are primarily dyeing and painting.

[0003] The dyeing process has numerous drawbacks. First, the large amount of chemical dyes used in the dyeing process not only causes serious environmental pollution, but also leaves TPU materials with poor color fastness after dyeing. During daily wear, especially after repeated washing or prolonged sunlight exposure, they are prone to fading, seriously affecting the aesthetics and product life of the shoe material. Second, the dyeing process also offers a limited variety of colors and patterns, making it difficult to meet consumer demand for personalized, diverse, and fashionable designs.

[0004] The painting process also faces challenges. During the painting process, it is difficult to spray the paint evenly, and problems such as sagging and uneven particles are prone to occur, resulting in a poor surface effect. In addition, the surface wear resistance and adhesion of TPU parts after painting are not ideal. After being hot-cut to form logos or decorative parts, the paint layer easily peels off due to daily friction, which in turn affects the overall quality of the shoe material. More importantly, the painting process has difficulty in accurately presenting complex textures and patterns, and it is impossible to achieve unique visual effects such as metallic luster and colorful gradients, which greatly limits the innovation and breakthroughs in the appearance design of footwear products.

[0005] With consumers' increasing demands for footwear appearance and growing environmental awareness, it's imperative to develop a TPU surface treatment process for footwear that is both environmentally friendly and capable of achieving diverse, exquisite, and unique appearances while also delivering superior performance. This process must not only overcome the shortcomings of traditional dyeing and painting processes but also meet the demands of large-scale production, thereby enhancing the market competitiveness of footwear materials. Summary of the Invention

[0006] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present invention is to provide an optical coating process for TPU transfer of shoe materials. The process is simple, the operation is easy to control, and it is conducive to large-scale industrial production. The prepared TPU with a textured structure has excellent tensile properties, the texture layer has good adhesion, hydrolysis resistance and aging resistance, and the optical coating layer has good adhesion and flexural resistance, with excellent comprehensive performance.

[0007] The purpose of the present invention is achieved by the following technical solution: an optical coating process for TPU transfer of shoe materials, comprising the following steps:

[0008] S1. Take a PC board, use a photolithography process to etch a texture layer on the surface of the PC board to obtain a texture board, ultrasonically clean the texture board for 15-20 minutes to remove surface impurities, and then perform a plasma surface activation treatment on the texture layer for 3-5 minutes under nitrogen protection to obtain a pretreated texture board;

[0009] S2. Take the TPU sheet and transfer adhesive, use a micro-gravure coater to evenly coat the transfer adhesive on the texture layer to obtain a transfer adhesive layer, place the TPU sheet on the transfer adhesive layer, and use a vacuum hot pressing laminating device to press at a pressure of 0.3-0.5 MPa and a temperature of 70-90°C for 3-6 minutes to obtain a layered structure;

[0010] S3. Send the layered structure into a tunnel furnace, set the temperature to 90-110°C, and the curing time to 12-18 minutes to preliminarily cure the transfer adhesive;

[0011] S4. After the initial curing, the TPU sheet and the transfer adhesive layer are peeled off from the texture plate, and the TPU sheet and the transfer adhesive layer are placed in a tunnel oven with the temperature controlled at 120-150°C and the curing time being 3-5 minutes to allow the transfer adhesive to be cured for the second time to obtain a TPU with a textured structure.

[0012] Furthermore, in step S1, the plasma processing power is 80-130 W, the pressure is 10-50 Pa, and the processing time is 90-150 s.

[0013] Furthermore, after step S4, the following step is also included: S5, under nitrogen protection, the TPU with a textured structure is plasma cleaned for 5-9 minutes, and then an optical coating is performed on the surface of the transfer adhesive layer using electron beam evaporation coating technology or sputtering coating.

[0014] Furthermore, in step S5, the plasma processing power is 80-130 W, the pressure is 10-50 Pa, and the processing time is 90-150 s.

[0015] Furthermore, in step S5, electron beam evaporation is used to first evaporate a 6-10 nm thick chromium base layer on the surface of the texture layer of the texture plate, and then evaporate a 18-22 nm thick titanium nitride film layer.

[0016] In another technical solution, in step S5, electron beam evaporation is used to alternately evaporate 8-12 layers of titanium dioxide and silicon dioxide on the surface of the texture layer of the texture plate, with each layer having a thickness of 5-9 nm.

[0017] Furthermore, the transfer adhesive comprises the following components in parts by weight: 65-75 parts of polyurethane solution, 25-35 parts of polyaniline-acrylic resin mixture, 8-12 parts of functional additive, 4-6 parts of curing agent and 7-9 parts of coupling agent.

[0018] Furthermore, the preparation step of the transfer adhesive includes the following steps: at room temperature, stirring and mixing the polyurethane solution, the polyaniline-acrylic resin mixture, the functional additive, the coupling agent and the curing agent according to parts by weight to obtain the transfer adhesive.

[0019] Furthermore, the preparation method of the polyurethane solution comprises the following steps:

[0020] A1. Place polyol, epoxy resin, and 1,4-butanediol in a reaction vessel, raise the temperature to 65-75°C, introduce nitrogen, and stir for 25-35 minutes. Then, add toluene diisocyanate and a catalyst, and allow the reaction to proceed for 35-45 minutes. Then, add a small amount of acetone and stir for 1-2 hours to obtain a polyurethane solution.

[0021] A2. Add diethyl malonate to the polyurethane solution at a temperature of 65-75° C. to carry out end-capping reaction for 1-2 hours to obtain a polyurethane solution.

[0022] Furthermore, the amount of acetone added accounts for 0.3-0.8% of the total mass of the polyol and toluene diisocyanate.

[0023] Furthermore, the mass ratio of the polyol to toluene diisocyanate is 1.8-2.2:1.

[0024] Furthermore, the amount of 1,4-butanediol added is 6-9% of the total mass of the polyol and toluene diisocyanate; and the amount of diethyl malonate added is 2-4% of the total mass of the polyol and toluene diisocyanate.

[0025] Furthermore, the polyol is prepared by mixing polyether polyol and castor oil in a molar ratio of 7:2-4. The polyether polyol is polyether N210.

[0026] Furthermore, the amount of the epoxy resin added is 8-12% of the total mass of the polyol and toluene diisocyanate. The epoxy resin is epoxy resin E-44.

[0027] Furthermore, the curing agent is isophorone diamine.

[0028] Furthermore, the polyaniline-acrylic resin mixture comprises the following raw materials in parts by weight: 4-10 parts of ammonium persulfate, 5-12 parts of dodecylbenzenesulfonic acid, 4-25 parts of acrylic resin, 2-6 parts of aniline monomer and 35-45 parts of water.

[0029] Furthermore, the polyaniline-acrylic polyurethane mixture comprises the following steps: uniformly mixing ammonium persulfate, dodecylbenzenesulfonic acid, acrylic resin, aniline monomer and water, reacting at room temperature for 4-6 hours, and drying to obtain the polyaniline-acrylic resin mixture.

[0030] Furthermore, the acrylic resin is Dow RESIN HF-05A.

[0031] Furthermore, the coupling agent is KH-560.

[0032] Furthermore, the preparation step of the functional additive includes the following steps:

[0033] B1. Dry the granular 4,4'-diaminodiphenylmethane until the mass remains unchanged;

[0034] B2. Crush 14-16 g of paraffin wax, add a certain amount of petroleum ether and stir with a glass rod to completely dissolve the solid paraffin wax to prepare paraffin solution 1;

[0035] B3. Place 10-14 g of solid paraffin in a reaction vessel and stir to melt at 80-90° C., add 3.4-3.8 g of Span-80 to the molten paraffin and stir evenly, then add a 6-8% by mass aqueous solution of Tween-80, shear and emulsify under high-speed stirring for 35-45 min, and then cool to room temperature with stirring to prepare a second paraffin solution;

[0036] B4. Mix paraffin solution 1 and paraffin solution 2 at a mass ratio of 5:2.8-3.2 to obtain a mixed solution;

[0037] B5. Add 30-40 g of dried granular 4,4'-diaminodiphenylmethane to the mixed solution and stir for 30-40 minutes. After standing, wash the precipitate to obtain a functional additive.

[0038] Furthermore, the particle size of the granular 4,4'-diaminodiphenylmethane is 10-20 μm.

[0039] Furthermore, the catalyst is at least one of dibutyltin dilaurate and stannous octoate, and the amount of the catalyst added is 3-5% of the total mass of the polyol and toluene diisocyanate.

[0040] The beneficial effects of the present invention are as follows: the optical coating process for TPU transfer of shoe materials of the present invention is simple in process, easy to control in operation, and is conducive to large-scale industrial production. The prepared TPU with a textured structure has excellent tensile properties, the texture layer has good adhesion, hydrolysis resistance and aging resistance, and the optical coating layer has good adhesion and bending resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 This is a product diagram of the present invention. DETAILED DESCRIPTION

[0042] In order to facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the embodiments. The contents mentioned in the embodiments are not intended to limit the present invention.

[0043] Example 1

[0044] In this embodiment, the optical coating process for TPU transfer of shoe materials includes the following steps:

[0045] S1. Take a PC board, photoetch a texture layer on the surface of the PC board using a photolithography process to obtain a textured board, ultrasonically clean the textured board for 18 minutes to remove surface impurities, and then perform a plasma surface activation treatment on the textured layer for 4 minutes under nitrogen protection to obtain a pretreated textured board;

[0046] S2. Take the TPU sheet and transfer adhesive, use a micro-gravure coater to evenly coat the transfer adhesive on the texture layer to obtain a transfer adhesive layer, place the TPU sheet on the transfer adhesive layer, and use a vacuum hot pressing laminating device to press at a pressure of 0.4 MPa and a temperature of 80°C for 4 minutes to obtain a layered structure;

[0047] S3, sending the layered structure into a tunnel furnace, setting the temperature to 100°C and the curing time to 16 minutes to preliminarily cure the transfer adhesive;

[0048] S4. After the initial curing, the TPU sheet and the transfer adhesive layer are peeled off from the texture plate, and the TPU sheet and the transfer adhesive layer are placed in a tunnel oven. The temperature is controlled at 140°C and the curing time is 4 minutes to allow the transfer adhesive to be cured for the second time to obtain a TPU with a textured structure.

[0049] Furthermore, in step S1, the plasma processing power is 100 W, the pressure is 40 Pa, and the processing time is 120 s.

[0050] Furthermore, the transfer adhesive comprises the following components in parts by weight: 65 parts of polyurethane solution, 25 parts of polyaniline-acrylic resin mixture, 8 parts of functional additive, 4 parts of curing agent and 7 parts of coupling agent.

[0051] Furthermore, the preparation step of the transfer adhesive includes the following steps: at room temperature, stirring and mixing the polyurethane solution, the polyaniline-acrylic resin mixture, the functional additive, the coupling agent and the curing agent according to parts by weight to obtain the transfer adhesive.

[0052] Furthermore, the preparation method of the polyurethane solution comprises the following steps:

[0053] A1. Place polyol, epoxy resin, and 1,4-butanediol in a reaction vessel, raise the temperature to 70°C, introduce nitrogen, and stir for 30 minutes. Then, add toluene diisocyanate and a catalyst, and catalyze the reaction for 40 minutes. Then, add a small amount of acetone and stir the reaction for 1.5 hours to obtain a polyurethane solution.

[0054] A2. Add diethyl malonate to the polyurethane solution at 70° C. to carry out end-capping reaction for 1.5 hours to obtain a polyurethane solution.

[0055] Furthermore, the amount of acetone added accounts for 0.5% of the total mass of the polyol and toluene diisocyanate.

[0056] Furthermore, the mass ratio of the polyol to toluene diisocyanate is 2:1.

[0057] Furthermore, the amount of 1,4-butanediol added is 8% of the total mass of the polyol and toluene diisocyanate; and the amount of diethyl malonate added is 3% of the total mass of the polyol and toluene diisocyanate.

[0058] Furthermore, the polyol is prepared by mixing polyether polyol and castor oil in a molar ratio of 7:3. The polyether polyol is polyether N210.

[0059] Furthermore, the amount of the epoxy resin added accounts for 10% of the total mass of the polyol and toluene diisocyanate. The epoxy resin is epoxy resin E-44.

[0060] Furthermore, the curing agent is isophorone diamine.

[0061] Furthermore, the polyaniline-acrylic resin mixture includes the following raw materials in parts by weight: 8 parts of ammonium persulfate, 7 parts of dodecylbenzenesulfonic acid, 12 parts of acrylic resin, 4 parts of aniline monomer and 40 parts of water.

[0062] Furthermore, the polyaniline-acrylic polyurethane mixture comprises the following steps: uniformly mixing ammonium persulfate, dodecylbenzenesulfonic acid, acrylic resin, aniline monomer and water, reacting at room temperature for 5 hours, and drying to obtain the polyaniline-acrylic resin mixture.

[0063] Furthermore, the acrylic resin is Dow RESIN HF-05A.

[0064] Furthermore, the coupling agent is KH-560.

[0065] Furthermore, the preparation step of the functional additive includes the following steps:

[0066] B1. Dry the granular 4,4'-diaminodiphenylmethane until the mass remains unchanged;

[0067] B2. Crush 15 g of paraffin wax, add a certain amount of petroleum ether and stir with a glass rod to completely dissolve the solid paraffin wax to prepare paraffin solution 1;

[0068] B3. Place 10-14 g of solid paraffin in a reaction vessel and stir to melt at 85° C. Add 3.6 g of Span-80 to the molten paraffin and stir evenly. Then add a 7% by mass aqueous solution of Tween-80. Shear and emulsify the mixture under high-speed stirring for 40 min, then cool to room temperature with stirring to prepare a second paraffin solution.

[0069] B4. Mix paraffin solution 1 and paraffin solution 2 in a mass ratio of 5:3 to obtain a mixed solution;

[0070] B5. Add 35 g of dried granular 4,4'-diaminodiphenylmethane to the mixed solution and stir for 35 minutes. After standing, wash the precipitate to obtain a functional additive.

[0071] Furthermore, the particle size of the granular 4,4'-diaminodiphenylmethane is 15 μm.

[0072] Furthermore, the catalyst is dibutyltin dilaurate, and the amount of the catalyst added is 4% of the total mass of the polyol and toluene diisocyanate.

[0073] Example 2

[0074] In this embodiment, the optical coating process for TPU transfer of shoe materials includes the following steps:

[0075] S1. Take a PC board, photoetch a texture layer on the surface of the PC board using a photolithography process to obtain a textured board, ultrasonically clean the textured board for 18 minutes to remove surface impurities, and then perform a plasma surface activation treatment on the textured layer for 4 minutes under nitrogen protection to obtain a pretreated textured board;

[0076] S2. Take the TPU sheet and transfer adhesive, use a micro-gravure coater to evenly coat the transfer adhesive on the texture layer to obtain a transfer adhesive layer, place the TPU sheet on the transfer adhesive layer, and use a vacuum hot pressing laminating device to press at a pressure of 0.4 MPa and a temperature of 80°C for 4 minutes to obtain a layered structure;

[0077] S3, sending the layered structure into a tunnel furnace, setting the temperature to 100°C and the curing time to 16 minutes to preliminarily cure the transfer adhesive;

[0078] S4. After the initial curing, the TPU sheet and the transfer adhesive layer are peeled off from the texture plate, and the TPU sheet and the transfer adhesive layer are placed in a tunnel oven. The temperature is controlled at 140°C and the curing time is 4 minutes to allow the transfer adhesive to be cured for the second time to obtain a TPU with a textured structure.

[0079] Furthermore, the transfer adhesive comprises the following components in parts by weight: 60 parts of polyurethane solution, 30 parts of polyaniline-acrylic resin mixture, 10 parts of functional additive, 5 parts of curing agent and 8 parts of coupling agent.

[0080] The rest of the content of this embodiment is the same as that of embodiment 1.

[0081] Example 3

[0082] In this embodiment, the optical coating process for TPU transfer of shoe materials includes the following steps:

[0083] S1. Take a PC board, photoetch a texture layer on the surface of the PC board using a photolithography process to obtain a textured board, ultrasonically clean the textured board for 18 minutes to remove surface impurities, and then perform a plasma surface activation treatment on the textured layer for 4 minutes under nitrogen protection to obtain a pretreated textured board;

[0084] S2. Take the TPU sheet and transfer adhesive, use a micro-gravure coater to evenly coat the transfer adhesive on the texture layer to obtain a transfer adhesive layer, place the TPU sheet on the transfer adhesive layer, and use a vacuum hot pressing laminating device to press at a pressure of 0.4 MPa and a temperature of 80°C for 4 minutes to obtain a layered structure;

[0085] S3, sending the layered structure into a tunnel furnace, setting the temperature to 100°C and the curing time to 16 minutes to preliminarily cure the transfer adhesive;

[0086] S4. After the initial curing, the TPU sheet and the transfer adhesive layer are peeled off from the texture plate, and the TPU sheet and the transfer adhesive layer are placed in a tunnel oven. The temperature is controlled at 140°C and the curing time is 4 minutes to allow the transfer adhesive to be cured for the second time to obtain a TPU with a textured structure.

[0087] Furthermore, the transfer adhesive comprises the following components in parts by weight: 75 parts of polyurethane solution, 35 parts of polyaniline-acrylic resin mixture, 12 parts of functional additive, 6 parts of curing agent and 9 parts of coupling agent.

[0088] The rest of the content of this embodiment is the same as that of embodiment 1.

[0089] Example 4

[0090] In this embodiment, the optical coating process for TPU transfer of shoe materials includes the following steps:

[0091] S1. Take a PC board, photoetch a texture layer on the surface of the PC board using a photolithography process to obtain a textured board, ultrasonically clean the textured board for 18 minutes to remove surface impurities, and then perform a plasma surface activation treatment on the textured layer for 4 minutes under nitrogen protection to obtain a pretreated textured board;

[0092] S2. Take the TPU sheet and transfer adhesive, use a micro-gravure coater to evenly coat the transfer adhesive on the texture layer to obtain a transfer adhesive layer, place the TPU sheet on the transfer adhesive layer, and use a vacuum hot pressing laminating device to press at a pressure of 0.4 MPa and a temperature of 80°C for 4 minutes to obtain a layered structure;

[0093] S3, sending the layered structure into a tunnel furnace, setting the temperature to 100°C and the curing time to 16 minutes to preliminarily cure the transfer adhesive;

[0094] S4. After the initial curing, the TPU sheet and the transfer adhesive layer are peeled off from the texture plate, and the TPU sheet and the transfer adhesive layer are placed in a tunnel oven. The temperature is controlled at 140°C and the curing time is 4 minutes to allow the transfer adhesive to be secondary cured to obtain a TPU with a textured structure.

[0095] S5. Under nitrogen protection, the TPU with a textured structure is plasma cleaned for 8 minutes, and then an optical coating is performed on the surface of the transfer adhesive layer using electron beam evaporation coating technology or sputtering coating.

[0096] Furthermore, in step S5, the plasma processing power is 100 W, the pressure is 40 Pa, and the processing time is 120 s.

[0097] Furthermore, in step S5, electron beam evaporation is used to deposit a film, first evaporating an 8 nm thick chromium base layer on the surface of the texture layer of the texture plate, and then evaporating a 15 nm thick titanium nitride film layer.

[0098] The rest of the content of this embodiment is the same as that of embodiment 1.

[0099] Example 5

[0100] In this embodiment, the optical coating process for TPU transfer of shoe materials includes the following steps:

[0101] S1. Take a PC board, photoetch a texture layer on the surface of the PC board using a photolithography process to obtain a textured board, ultrasonically clean the textured board for 18 minutes to remove surface impurities, and then perform a plasma surface activation treatment on the textured layer for 4 minutes under nitrogen protection to obtain a pretreated textured board;

[0102] S2. Take the TPU sheet and transfer adhesive, use a micro-gravure coater to evenly coat the transfer adhesive on the texture layer to obtain a transfer adhesive layer, place the TPU sheet on the transfer adhesive layer, and use a vacuum hot pressing laminating device to press at a pressure of 0.4 MPa and a temperature of 80°C for 4 minutes to obtain a layered structure;

[0103] S3, sending the layered structure into a tunnel furnace, setting the temperature to 100°C and the curing time to 16 minutes to preliminarily cure the transfer adhesive;

[0104] S4. After the initial curing, the TPU sheet and the transfer adhesive layer are peeled off from the texture plate, and the TPU sheet and the transfer adhesive layer are placed in a tunnel oven. The temperature is controlled at 140°C and the curing time is 4 minutes to allow the transfer adhesive to be secondary cured to obtain a TPU with a textured structure.

[0105] S5. Under nitrogen protection, the TPU with a textured structure is plasma cleaned for 8 minutes, and then an optical coating is performed on the surface of the transfer adhesive layer using electron beam evaporation coating technology or sputtering coating.

[0106] Furthermore, in step S5, the plasma processing power is 100 W, the pressure is 40 Pa, and the processing time is 120 s.

[0107] Furthermore, in step S5, electron beam evaporation is used to alternately evaporate 10 layers of titanium dioxide and silicon dioxide on the surface of the texture layer of the texture plate, with each layer having a thickness of 8 nm.

[0108] The rest of the content of this embodiment is the same as that of embodiment 1.

[0109] Comparative Example 1

[0110] The difference between this comparative example and Example 2 is that an equal amount of polyurethane solution is used instead of the polyaniline-acrylic resin mixture. That is, the transfer adhesive comprises the following components in parts by weight: 90 parts of polyurethane solution, 10 parts of functional additive, 5 parts of curing agent, and 8 parts of coupling agent.

[0111] Comparative Example 2

[0112] The difference between this comparative example and Example 2 is that the functional auxiliary agent is paraffin.

[0113] Comparative Example 3

[0114] This comparative example differs from Example 5 in that an equal amount of acrylic resin is used in place of the polyaniline-acrylic resin mixture. Specifically, the transfer adhesive comprises the following components by weight: 60 parts polyurethane solution, 30 parts acrylic resin, 10 parts functional additive, 5 parts curing agent, and 8 parts coupling agent. The acrylic resin used is Dow RESIN HF-05A.

[0115] Performance Testing

[0116] Performance tests were performed on the TPU with textured structures prepared in Example 2 and Comparative Examples 1-2, and the TPU shoe materials prepared in Example 5 and Comparative Example 3.

[0117] (1) The tensile strength, adhesion and aging resistance of the textured TPU obtained in Example 2 and Comparative Examples 1-2 were tested. The test data are shown in Table 1 below:

[0118] Table 1

[0119]

[0120] (2) The adhesion and bending resistance of the optical coating layers of the TPU shoe materials prepared in Example 5 and Comparative Example 3 were tested. The test data are shown in Table 2 below:

[0121] Table 2

[0122] project Bending resistance Adhesion Example 5 60,000 cracks Level 0 Comparative Example 3 50,000 cracks Level 1

[0123] The tensile strength test was carried out according to GB / T 1040.3-2006, and the tensile rate was 100 mm / min.

[0124] Adhesion test adopts GB / T 9286-1998;

[0125] The hydrolysis resistance test adopts QB / T 2888: soak in 10% sodium hydroxide solution at 30°C for 24 hours;

[0126] The aging resistance test was conducted using QUV340nm for 1000 hours with a light intensity of 0.8W / cm 2 ;

[0127] Flexibility test: Cut the TPU soccer ball leather into 70mm x 45mm pieces and use a flex tester to perform a bending test on the TPU shoe material at room temperature to observe the damage of the optical coating layer.

[0128] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the scope of protection of the present invention.

Claims

1. The optical coating process for TPU transfer of shoe materials is characterized by: The steps include: S1. Take a PC board, use a photolithography process to etch a texture layer on the surface of the PC board to obtain a texture board, ultrasonically clean the texture board for 15-20 minutes to remove surface impurities, and then perform a plasma surface activation treatment on the texture layer for 3-5 minutes under nitrogen protection to obtain a pretreated texture board; S2. Take the TPU sheet and transfer adhesive, use a micro-gravure coater to evenly coat the transfer adhesive on the texture layer to obtain a transfer adhesive layer, place the TPU sheet on the transfer adhesive layer, and use a vacuum hot pressing laminating device to press at a pressure of 0.3-0.5 MPa and a temperature of 70-90°C for 3-6 minutes to obtain a layered structure; S3. Send the layered structure into a tunnel furnace, set the temperature to 90-110°C, and the curing time to 12-18 minutes to preliminarily cure the transfer adhesive; S4. After the initial curing, the TPU sheet and the transfer adhesive layer are peeled off from the texture plate, and the TPU sheet and the transfer adhesive layer are placed in a tunnel oven. The temperature is controlled at 120-150°C and the curing time is 3-5 minutes to allow the transfer adhesive to be secondary cured to obtain a TPU with a textured structure. S5. Under nitrogen protection, the TPU with a textured structure is plasma cleaned for 5-9 minutes, and an optical coating is performed on the surface of the transfer adhesive layer using electron beam evaporation coating technology or sputtering coating.

2. The optical coating process for TPU transfer of shoe materials according to claim 1, characterized in that: The transfer adhesive comprises the following components in parts by weight: 65-75 parts of a polyurethane solution, 25-35 parts of a polyaniline-acrylic resin mixture, 8-12 parts of a functional additive, 4-6 parts of a curing agent, and 7-9 parts of a coupling agent.

3. The optical coating process for TPU transfer of shoe materials according to claim 2, characterized in that: The preparation step of the transfer adhesive comprises the following steps: at room temperature, stirring and mixing a polyurethane solution, a polyaniline-acrylic resin mixture, a functional additive, a coupling agent and a curing agent according to parts by weight to obtain the transfer adhesive.

4. The optical coating process for TPU transfer of shoe materials according to claim 2, characterized in that: The preparation method of the polyurethane solution comprises the following steps: A1. Place polyol, epoxy resin, and 1,4-butanediol in a reaction vessel, raise the temperature to 65-75°C, introduce nitrogen, and stir for 25-35 minutes. Add toluene diisocyanate and a catalyst, and allow the reaction to proceed for 35-45 minutes. Then, add a small amount of acetone and stir for 1-2 hours to obtain a polyurethane solution. A2. Add diethyl malonate to the polyurethane solution at a temperature of 65-75° C. to carry out end-capping reaction for 1-2 hours to obtain a polyurethane solution.

5. The optical coating process for TPU transfer of shoe materials according to claim 4, characterized in that: The mass ratio of the polyol to toluene diisocyanate is 1.8-2.2:

1.

6. The optical coating process for TPU transfer of shoe materials according to claim 4, characterized in that: The added amount of the 1,4-butanediol accounts for 6-9% of the total mass of the polyol and toluene diisocyanate; the added amount of the diethyl malonate accounts for 2-4% of the total mass of the polyol and toluene diisocyanate.

7. The optical coating process for TPU transfer of shoe materials according to claim 4, characterized in that: The polyol is prepared by mixing polyether polyol and castor oil in a molar ratio of 7:2-4.

8. The optical coating process for TPU transfer of shoe materials according to claim 4, characterized in that: The added amount of the epoxy resin accounts for 8-12% of the total mass of the polyol and toluene diisocyanate.

9. The optical coating process for TPU transfer of shoe materials according to claim 4, characterized in that: The epoxy content of the epoxy resin is 8-12 wt%.

10. The optical coating process for TPU transfer of shoe materials according to claim 4, characterized in that: The curing agent is isophorone diamine.

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