Preparation method of paint film of excimer UV skin-touch paint

Abstract

The invention relates to the technical field of skin-touch coatings, in particular to a preparation method of a paint film of an excimer UV skin-touch coating which comprises the following components in percentage by mass: 30%-90% of resin, 5%-40% of monomers, 0.01%-10% of a photoinitiator and 0.01%-10% of an auxiliary agent, the prepared paint film is soft and smooth in surface, low in glossiness, good in wear-resistant effect and good in chemical resistance, the uneven structure formed by the difference of curing of the surface layer and the inner layer of the paint and the effect of microcosmic wrinkles caused by shrinkage of the surface layer achieves the effects that the surface glossiness is low, and the glossiness is lower than 10 degrees when the incident angle is tested to be 60 degrees; and the generated wrinkles are very fine and are naturally generated radians, so that the hand feeling is very smooth, the dynamic friction coefficient of the surface is very low, and the wrinkles on the surface of the coating are caused because the surface curing speed and the bottom curing speed are different, the surface shrinkage is large and the inside shrinkage is small.

Description

[0001] This application is a divisional application. The application number of the original application is 202411427437.3, the application date is October 14, 2024, and the name of the invention is: Excimer UV skin-feel coating and its paint film preparation method. Technical Field

[0002] The present invention relates to the technical field of skin-feel coatings, and in particular to a method for preparing a paint film of an excimer UV skin-feel coating. Background Art

[0003] Skin-feel coatings are favored by consumers for their delicate softness, smooth feel and skin-like effect. At the same time, the skin-feel coatings do not contain any toxic substances and will not harm people's health. They are mainly used in the 3C mobile phone back cover field.

[0004] Skin-feel matte paint is generally made by mixing some tactile additives or matte powder into the previously used UV high-gloss paint to form surface bumps to achieve a matte surface effect. The surface is formed and the touch is changed by changing the particle size and hardness of the matte powder. The surface unevenness is completely determined by the size of the added particles. The uniformity of the coating is difficult to control, and the wrinkle structure and feel of the paint film cannot be guaranteed.

[0005] Therefore, in order to solve the problem that the uniformity of the coating cannot be controlled by changing the particle size and hardness of the matte powder, an excimer UV skin-feel coating and a method for preparing the paint film thereof can be designed. Summary of the Invention

[0006] In order to overcome the problem of poor control of coating uniformity.

[0007] The technical solution of the present invention is: an excimer UV skin-feel coating, comprising a phase A, wherein the phase A comprises the following components in percentage by mass: resin: 30% to 90%, monomer: 5% to 40%, photoinitiator: 0.01% to 10%, and additive: 0.01% to 10%; The paint film preparation method is as follows: Step 1: Apply phase A coating on the substrate and pre-cure it with LED with a wavelength of 395nm. The energy required for curing is 1000~4000mJ / , light intensity is 500~4000mW / , use 172nm or 185nm or 254nm ultraviolet light to cure in nitrogen, or use 254nm ultraviolet light to cure in air; Step 2: The coating surface has wrinkles in the range of 1 to 3 μm in thickness due to shrinkage caused by curing. The glossiness is tested at an incident angle of 60 degrees. The wrinkles on the surface cause the glossiness of the coating to drop sharply from 100 to 1 to 20. The UVC energy required for surface curing is 50 to 400 mJ / , light intensity is 5~20mW / ; Step 3: Fully cure with high pressure mercury lamp, UVA energy is 1000~2000mJ / , UVA light intensity is 50~500mW / During the third curing, the surface of the coating is rapidly cured within 10 to 120 seconds at 1 to 3 μm due to the UVC band, while the bottom layer has not yet cured, forming a wrinkled structure to obtain a paint film, and then the middle and bottom of the coating are fully cured by UVA.

[0008] Preferably, the coating further comprises a phase B, which is a diluent, and the mass percentage of the diluent in the coating is 0% to 90%.

[0009] Preferably, the resin is any one or more combinations of modified acrylate resin, polyester acrylate, polyurethane acrylate, epoxy acrylate, silicon-modified acrylate and fluorine-modified acrylate.

[0010] Preferably, the monomer is any one or more combinations of monofunctional monomers, difunctional monomers, trifunctional monomers and multifunctional monomers.

[0011] Preferably, the photoinitiator includes a type I free radical photoinitiator and a type II free radical photoinitiator.

[0012] Preferably, the auxiliary agent includes any one or more combinations of a leveling agent, a defoaming agent and a nucleating agent.

[0013] Preferably, the diluent is any one or more of ethanol, isopropanol, ethyl ester, butyl ester, PM, PMA, MIBK and butanone.

[0014] Preferably, the coating can be applied by roller coating, flow coating or printing.

[0015] The beneficial effects of the present invention are as follows: the surface of the prepared paint film is smooth and has low gloss, good wear resistance and good chemical resistance. Due to the difference in curing of the surface layer and the inner layer of the coating itself, the surface layer shrinks to create a microscopic wrinkle effect, and the uneven structure formed achieves a low surface gloss, with the glossiness tested at an incident angle of 60 degrees being less than 10 degrees. Moreover, the wrinkles produced are very delicate and are naturally generated curvatures, so the hand feels very smooth. The dynamic friction coefficient of the surface is very low, and the friction coefficient is below 0.1. It is not a coating formed by adding matte powder or additives, so there is no problem of poor uniformity control. During the curing process of the coating, because the surface curing speed is different from the bottom curing speed, the surface shrinks more and the inside shrinks less, resulting in wrinkles on the coating surface. The obtained paint film has good adhesion to the paint material, high hardness and good chemical resistance. DETAILED DESCRIPTION

[0016] The present invention will be further described below with reference to the embodiments.

[0017] Example 1 The present invention provides an embodiment: an excimer UV skin-feel coating, comprising the following components in percentage by mass: Resin (B-241): 51.2% Monomer (9EOTMPTA): 15.7% Photoinitiator (TPO): 0.4% Photoinitiator (MBF): 0.8% Leveling agent (AFCONA3777): 0.4% Diluent (butyl ester): 31.5%; The preparation method of the excimer UV skin-feel paint film is as follows: the paint is adjusted to a density of 0.995 with butyl ester and then coated on the acrylic surface of the composite board (PMMA / PC), dried at room temperature for 1 minute, dried in an oven at 50 degrees for 1 minute, baked at high temperature, and then illuminated with a 395nm LED lamp with a light intensity of 2200mW / , energy 2600mJ / Pre-curing, using 254nm UV lamp at 9mW / Under light intensity, energy 100mJ / After surface curing, use 1800mJ / Energy UV mercury lamp, light intensity is 240mW / , obtaining a coating with a matte surface effect.

[0018] Example 2 The present invention provides an embodiment: an excimer UV skin-feel coating, comprising the following components in percentage by mass: Resin (B-241): 49.6% Monomer (9EOTMPTA): 15.3% Nucleating agent (OK520): 3.1% Photoinitiator (TPO): 0.4% Photoinitiator (MBF): 0.8% Leveling agent (AFCONA3777): 0.4% Diluent (butyl ester): 30.4%; The preparation method of the excimer UV skin-feel paint film is as follows: the paint is adjusted to a density of 0.995 with butyl ester and then coated on the acrylic surface of the composite board (PMMA / PC), dried at room temperature for 1 minute, dried in an oven at 50 degrees for 1 minute, baked at high temperature, and then illuminated with a 395nm LED lamp with a light intensity of 2200mW / , energy 2600mJ / Pre-curing, using 254nm UV lamp at 9mW / Under light intensity, energy 100mJ / After surface curing, use 1800mJ / Energy UV mercury lamp, light intensity is 240mW / , obtaining a coating with a matte surface effect.

[0019] Example 3 The present invention provides an embodiment: an excimer UV skin-feel coating, comprising the following components in percentage by mass: Resin (luCure5326): 50.3% Monomer (9EOTMPTA): 15.4% Nucleating agent (OK520): 1.6% Photoinitiator (TPO): 0.5% Photoinitiator (184): 0.8% Leveling agent (AFCONA3777): 0.4% Diluent (butyl ester): 31.0%; The preparation method of the excimer UV skin-feel paint film is as follows: the paint is adjusted to a density of 0.995 with butyl ester and then coated on the acrylic surface of the composite board (PMMA / PC), dried at room temperature for 1 minute, dried in an oven at 50 degrees for 1 minute, baked at high temperature, and then illuminated with a 395nm LED lamp with a light intensity of 2200mW / , energy 2600mJ / Pre-curing, using 254nm UV lamp at 9mW / Under light intensity, energy 100mJ / After surface curing, use 1800mJ / Energy UV mercury lamp, light intensity is 240mW / , obtaining a coating with a matte surface effect.

[0020] Example 4 The present invention provides an embodiment: an excimer UV skin-feel coating, comprising the following components in percentage by mass: Resin (luCure5326): 51.1% Monomer (9EOTMPTA): 15.6% Nucleating agent (OK520): 0.1% Photoinitiator (TPO): 0.4% Photoinitiator (184): 0.8% Leveling agent (AFCONA3777): 0.4% Diluent (butyl ester): 31.4%; The preparation method of the excimer UV skin-feel paint film is as follows: the paint is adjusted to a density of 0.995 with butyl ester and then coated on the acrylic surface of the composite board (PMMA / PC), dried at room temperature for 1 minute, dried in an oven at 50 degrees for 1 minute, baked at high temperature, and then illuminated with a 395nm LED lamp with a light intensity of 2200mW / , energy 2600mJ / Pre-curing, using 254nm UV lamp at 9mW / Under light intensity, energy 100mJ / After surface curing, use 1800mJ / Energy UV mercury lamp, light intensity is 240mW / , obtaining a coating with a matte surface effect.

[0021] Example 5 The present invention provides an embodiment: an excimer UV skin-feel coating, comprising the following components in percentage by mass: Resin (luCure5326): 49.8% Monomer (9EOTMPTA): 15.3% Nucleating agent (OK520): 0.8% Photoinitiator (TPO): 0.8% Photoinitiator (184): 2.3% Leveling agent (AFCONA3777): 0.4% Diluent (butyl ester): 30.6%; The preparation method of the excimer UV skin-feel paint film is as follows: the paint is adjusted to a density of 0.995 with butyl ester and then coated on the acrylic surface of the composite board (PMMA / PC), dried at room temperature for 1 minute, dried in an oven at 50 degrees for 1 minute, baked at high temperature, and then illuminated with a 395nm LED lamp with a light intensity of 2200mW / , energy 2600mJ / Pre-curing, using 254nm UV lamp at 9mW / Under light intensity, energy 100mJ / After surface curing, use 1800mJ / Energy UV mercury lamp, light intensity is 240mW / , obtaining a coating with a matte surface effect.

[0022] In the present invention, the purpose of high temperature hot air or infrared baking is mainly to volatilize the diluent. Only after the diluent is volatilized can curing be carried out, otherwise it will not be dried after the final UV curing. When the diluent is 0%, high temperature baking is not required.

[0023] Comparative Example 1 The coating includes the following components: Resin (6145): 49.6% Monomer (9EOTMPTA): 15.3% Matte powder (OK500): 3.1% Photoinitiator (TPO): 0.4% Photoinitiator (184): 0.8% Leveling agent (AFCONA3777): 0.4% Diluent (butyl ester): 30.4%; Preparation of paint film: adjust the coating to a density of 0.995 with butyl ester and apply it on the acrylic surface of the composite board (PMMA / PC). Dry it at room temperature for 1 minute, dry it in an oven at 80 degrees for 1 minute, and then place it at room temperature for 1 minute. Then, irradiate it with a UV mercury lamp with an energy of 800mJ / , obtaining a coating with a matte surface effect.

[0024] Comparative Example 2 The coating includes the following components: Resin (6145): 50.0% Monomer (9EOTMPTA): 15.4% Matte powder (OK500): 2.3% Photoinitiator (TPO): 0.4% Photoinitiator (184): 0.8% Leveling agent (AFCONA3777): 0.4% Diluent (butyl ester): 30.7%; Preparation of paint film: adjust the coating to a density of 0.995 with butyl ester and apply it on the acrylic surface of the composite board (PMMA / PC). Dry it at room temperature for 1 minute, dry it in an oven at 80 degrees for 1 minute, and then place it at room temperature for 1 minute. Then, irradiate it with a UV mercury lamp with an energy of 800mJ / , obtaining a coating with a matte surface effect.

[0025] Comparative Example 3 The coating includes the following components: Resin (6145): 50.3% Monomer (9EOTMPTA): 15.5% Matt powder (OK500): 1.6% Photoinitiator (TPO): 0.4% Photoinitiator (184): 0.8% Leveling agent (AFCONA3777): 0.4% Diluent (butyl ester): 31.0%; Preparation of paint film: adjust the coating to a density of 0.995 with butyl ester and apply it on the acrylic surface of the composite board (PMMA / PC). Dry it at room temperature for 1 minute, dry it in an oven at 80 degrees for 1 minute, and then place it at room temperature for 1 minute. Then, irradiate it with a UV mercury lamp with an energy of 800mJ / , obtaining a coating with a matte surface effect.

[0026] Comparative Example 4 The coating includes the following components: Resin (luCure5326): 22.9% Monomer (9EOTMPTA): 24.1% Matte powder (OK500): 4.8% Leveling agent (AFCONA3777): 0.6% Diluent (butyl ester): 47.6%; Preparation of paint film: adjust the coating to a density of 0.995 with butyl ester and apply it on the acrylic surface of the composite board (PMMA / PC). Dry it at room temperature for 1 minute, dry it in an oven at 80 degrees for 1 minute, and then place it at room temperature for 1 minute. Then, irradiate it with a UV mercury lamp with an energy of 800mJ / , obtaining a coating with a matte surface effect.

[0027] Test Example 1 Examples 1-5 and Comparative Examples 1-4 were tested, and the test contents and methods were as follows:

[0028] The test results are as follows:

[0029] Example 6 The coating in Example 1 was adjusted to a density of 0.995 and then coated on the acrylic surface of a composite board (PMMA / PC). After drying at room temperature for 1 minute and drying in an oven at 50 degrees for 1 minute, it was pre-cured with a 395nm LED light intensity and energy (see Table 1), and then surface-cured with a 254nm UV lamp at a certain light intensity and energy (see Table 1). After that, it was irradiated for the third time with a UV mercury lamp of different light intensities and energies (see Table 1). The properties of the resulting paint films are shown in Table 2.

[0030] Table 1 shows the lighting conditions and energy conditions.

[0031]

[0032] Table 1 Table 2 is the paint film performance table.

[0033]

[0034] Table 2 Example 7 Comparative Example 1 and Example 1 were cured according to the following methods to prepare coatings, and the properties were tested and obtained as shown in Table 3.

[0035] 1. The coating in comparative example 1 was adjusted to a density of 0.925 and sprayed on the acrylic surface of the composite board (PMMA / PC). It was dried at room temperature for 1 minute, dried in an oven at 80 degrees for 1 minute, and then placed at room temperature for 1 minute. It was then irradiated with a UV mercury lamp with an energy of 800mJ / , obtaining a coating A with a matte surface effect; 2. The coating in Example 1 was adjusted to a density of 0.925 and then applied to the acrylic surface of the composite board (PMMA / PC). The coating was dried at room temperature for 1 minute, then dried in an oven at 80 degrees for 1 minute, and then placed at room temperature for 1 minute. The coating was then irradiated with a UV mercury lamp with an energy of 800mJ / , obtaining a coating B with a matte surface effect; 3. Adjust the coating in comparative example 1 to a density of 0.995 and apply it on the acrylic surface of the composite board (PMMA / PC). Dry it at room temperature for 1 minute and in an oven at 50 degrees for 1 minute. , energy 2600mJ / Pre-curing, using 254nm UV lamp at 9mW / Under light intensity, energy 100mJ / After surface curing, use 1800mJ / Energy UV mercury lamp, light intensity is 240mW / , obtaining a coating C with a matte surface effect; 4. Adjust the coating in Example 1 to a density of 0.995 and apply it to the acrylic surface of the composite board (PMMA / PC). Dry it at room temperature for 1 minute and in an oven at 50 degrees for 1 minute. First, use a 395nm LED lamp with a light intensity of 2200mW / , energy 2600mJ / Pre-curing, using 254nm UV lamp at 9mW / Under light intensity, energy 100mJ / After surface curing, use 1800mJ / Energy UV mercury lamp, light intensity is 240mW / , obtaining a coating D with a matte surface effect.

[0036]

[0037] Table 3 Due to the difference in curing between the surface and inner layers of the coating itself, the surface shrinks to create a microscopic wrinkle effect, and the uneven structure formed achieves a low surface gloss. The glossiness tested at an incident angle of 60 degrees is less than 10 degrees. Moreover, the wrinkles produced are very delicate and are naturally generated curvatures, so the hand feels very smooth, and the dynamic friction coefficient of the surface is very low, less than 0.1.

[0038] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge of those skilled in the art without departing from the spirit of the present invention.

Claims

1. A method for preparing a paint film of an excimer UV skin-feel coating, characterized in that: The preparation method comprises the following steps: Step 1: Pre-curing: Apply the coating on the substrate to obtain a coating, and pre-curing it with an LED with a wavelength of 395nm. The energy required for pre-curing is 1000-4000mJ / , light intensity is 500~4000mW / ; Step 2: Surface curing: Surface curing of the coating to obtain a paint film. The UVC energy required for the surface curing is 50-400 mJ / , light intensity is 5~20mW / ; Step 3 Full curing: Use a high pressure mercury lamp to fully cure the paint film. The UVA energy required for full curing is 1000-2000mJ / , UVA light intensity is 50~500mW / ; The coating comprises the following components in percentage by mass: resin: 30% to 90%, monomer: 5% to 40%, photoinitiator: 0.01% to 10%, and additive: 0.01% to 10%.

2. The method for preparing a paint film of an excimer UV skin-feel coating according to claim 1, wherein: The coating also includes a diluent, and the mass percentage of the diluent in the coating is 0% to 90%.

3. The method for preparing a paint film of an excimer UV skin-feel coating according to claim 1, wherein: The resin is any one or more combinations of modified acrylate resin, polyester acrylate, polyurethane acrylate, epoxy acrylate and silicon-modified acrylate.

4. The method for preparing a paint film of an excimer UV skin-feel coating according to claim 1, wherein: The monomer is any one or more combinations of monofunctional monomers, difunctional monomers, trifunctional monomers and multifunctional monomers.

5. The method for preparing a paint film of an excimer UV skin-feel coating according to claim 1, wherein: Photoinitiators include type I free radical photoinitiators and type II free radical photoinitiators.

6. The method for preparing a paint film of an excimer UV skin-feel coating according to claim 1, wherein: The auxiliary agent includes any one or more combinations of leveling agents, defoaming agents and nucleating agents.

7. The method for preparing a paint film of an excimer UV skin-feel coating according to claim 2, wherein: The diluent is any one or more combinations of ethanol, isopropanol, ethyl ester, butyl ester, PM, PMA, MIBK and butanone.

8. The method for preparing a paint film of an excimer UV skin-feel coating according to claim 1, wherein: The coating can be applied by roller coating, curtain coating or printing.

9. The method for preparing a paint film of an excimer UV skin-feel coating according to claim 1, wherein: In step 2, the coating surface is microscopically exposed to the UVC band, and the surface 1 to 3 μm is rapidly cured within 10 to 120 seconds, while the bottom layer has not yet been cured, forming a wrinkled structure to obtain a paint film. The coating surface has wrinkles in the thickness range of 1 to 3 μm due to the shrinkage caused by the surface curing. The glossiness is tested at an incident angle of 60 degrees. The wrinkles on the surface cause the glossiness of the coating to drop sharply, and the glossiness drops directly from 100 to 1 to 20.

10. The method for preparing a paint film of an excimer UV skin-feel coating according to claim 1, wherein: In step three, the middle and bottom parts of the paint film are fully cured by UVA.

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