Light-cured organic silicon resin material for organic silicon leather surface coating and preparation method of light-cured organic silicon resin material

Abstract

The invention discloses a flexible high-wear-resistance light-cured organic silicon resin material for an organic silicon leather surface coating, which is prepared from the following ingredients in parts by mass: 10 to 20 parts of hyperbranched polysiloxane with side chains containing acrylic acid, 20 to 40 parts of polysiloxane with end groups containing acrylic acid, 50 to 70 parts of isobornyl acrylate and 0.2 to 0.6 part of photoinitiators. The viscosity of the hyperbranched polysiloxane with the side chain containing acrylic acid ranges from 1800 cps to 15000 cp. And the viscosity of the polysiloxane with the end group containing acrylic acid is 50-200 cps. The flexible high-wear-resistance light-cured organic silicon resin material for the organic silicon leather surface coating has the characteristics of high hardness, high flexibility and high curing speed, is suitable for being used as an organic silicon leather surface wear-resistant coating, and has the characteristics of easiness in molding, no solvent and environmental friendliness.

Description

Technical Field

[0001] The invention belongs to the field of photocurable materials, and in particular relates to a flexible and highly wear-resistant photocurable silicone resin material for silicone leather surface coating. Background Art

[0002] Silicone leather is an environmentally friendly leather that has become popular this year. It is a composite material formed by combining silicone materials with fibers and non-woven fabrics. It has advantages in hydrolysis resistance, low VOC, no odor, and environmental protection. Due to the requirements for flexibility and hand feel, silicone rubber is usually used as the surface matrix material. Although the leather formed by silicone materials has better wear resistance than natural leather, PU leather, and PVC leather, the current energy-saving automotive interior, furniture and other markets still have higher requirements for its wear resistance.

[0003] Wear resistance is closely related to material hardness. Hardness is the ability of the material surface to resist external forces. Materials with higher hardness usually have better wear resistance.

[0004] Compared with silicone rubber, silicone resin usually has higher strength and hardness, which also means better wear resistance. Adding a layer of silicone resin coating on the surface of silicone rubber can further enhance the wear resistance of leather. However, as a leather surface coating, it also needs to be flexible, which poses a challenge to the coating material.

[0005] For resins and other polymer systems, hardness and flexibility usually have a mutually restrictive relationship. From the perspective of molecular structure, a higher cross-linking density can provide higher hardness, but the flexibility of the material will also decrease. Introducing a hyperbranched structure can increase the hardness of the material without relying on an increase in cross-linking density, and is a method that can take into account both hardness and flexibility.

[0006] In addition, the coating also needs to consider the bonding effect with the silicone surface adhesive in silicone leather. The silicone surface adhesive used in silicone leather is mainly a vinyl silicone oil hydrosilane addition system. The photocuring system contains a large number of acrylate groups that can fully cross-link with the residual double bonds in the surface adhesive to ensure adhesion.

[0007] In addition, the photocuring system has the advantages of high efficiency, solvent-free and environmentally friendly, and is very suitable for use in the production and processing of silicone leather, especially in the production process of automated unmanned factories.

[0008] Therefore, developing a silicone resin coating material that has both high hardness and high flexibility as well as high efficiency of photocuring and solvent-free and environmentally friendly properties is of great significance to the silicone leather industry. Summary of the invention

[0009] The purpose of the present invention is to solve the current market demand for higher wear resistance of silicone leather and to provide a flexible photocurable silicone resin that can be used to improve the wear resistance of silicone leather.

[0010] In order to solve the above technical problems, the present invention provides the following technical solutions: The preparation method of hyperbranched polysiloxane containing acrylic acid in the side chain comprises the following steps: Dimethyldimethoxysilane and acrylic silane coupling agent are mixed evenly, and then the temperature is raised to 70-80°C, and diluted hydrochloric acid is added dropwise. After neutralization reaction, washing, drying and desulfurization are completed, dimethylsiloxane mixed ring body is added, and then reacted at 60-80°C. After the reaction is completed, the hyperbranched polysiloxane containing acrylic acid on the side chain is obtained by filtering and desulfurization.

[0011] The acrylic silane coupling agent is at least one of LT-570 and LT-571 produced by New Blue Sky Company.

[0012] The dimethylsiloxane mixed ring body is DMC from Hubei Xingrui Silicon Materials.

[0013] In the raw materials, the mass fractions of dimethyldimethoxysilane, acrylic silane coupling agent and dimethylsiloxane mixed ring body are 100-150 parts, 20-30 parts and 1600-8000 parts.

[0014] In some specific technical schemes, 100 parts of dimethyldimethoxysilane and 20-30 parts of acrylic silane coupling agent are added to a reaction container and mixed evenly, then the temperature is raised to 70-80°C, 120 parts of dilute hydrochloric acid are added dropwise, and the reaction is carried out for 2-3 hours. After neutralization, washing, drying and deoxidation, 1600-8000 parts of dimethylsiloxane mixed ring body are added, and the reaction is carried out at 60-70°C for 5-12 hours, and the product is obtained by filtration and deoxidation.

[0015] The dilute hydrochloric acid refers to a concentration of 0.1-0.5 mol / L.

[0016] The prepared hyperbranched polysiloxane containing acrylic acid in the side chain has a viscosity between 1800 cps and 15000 cps, and a mass fraction of the chain segments containing acrylic acid groups is between 1% and 5%.

[0017] Another technical solution of the present invention is to provide a photocurable organic silicone resin material, including the hyperbranched polysiloxane containing acrylic acid in the side chain prepared by the method.

[0018] The photocurable organic silicon resin material comprises 10-20 parts of hyperbranched polysiloxane containing acrylic acid in the side chain, 20-40 parts of polysiloxane containing acrylic acid in the terminal group, 50-70 parts of isobornyl acrylate and 0.2-0.6 parts of a photoinitiator.

[0019] The structure of the polysiloxane containing acrylic acid at the end group is:

[0020] Wherein R1 and R2 are one of acrylate group and hydroxyl group, and each terminal polysiloxane containing acrylic acid contains at least one acrylate group, and n makes its viscosity in the range of 50-200 cps.

[0021] The photoinitiator used is one or more of ethyl 2,4,6-trimethylbenzoylphenylphosphonate, diphenyl (2,4,6-trimethylphenylformyl) phosphine oxide, and 1-hydroxycyclohexyl phenyl ketone.

[0022] The photocurable silicone resin material further comprises auxiliary agents, which include polymerization inhibitors, essences, rheological agents and anti-yellowing agents.

[0023] In some embodiments, the preparation method of the photocurable silicone resin material is: add a hyperbranched polysiloxane containing acrylic acid on the side chain, a polysiloxane containing acrylic acid on the end group, isobornyl acrylate, and a photoinitiator into a reaction kettle in sequence, disperse at 100-200 r / min for 0.1-1h, and vacuum defoam to obtain a photocurable silicone resin.

[0024] In this step, an auxiliary agent is selectively added to prepare a light-curing silicone resin.

[0025] In view of the above technical solution, a silicone resin material for silicone leather surface coating is provided, which adopts the light-curing silicone resin material.

[0026] In some embodiments, the method for preparing the silicone resin material for silicone leather surface coating is as follows: pouring the photocurable silicone resin into a mold, coating it on the surface of the silicone leather, and irradiating it under ultraviolet light under nitrogen protection to obtain the silicone leather surface coating material.

[0027] The irradiation conditions under the ultraviolet lamp are irradiation under 350-365nm ultraviolet lamp for 0.5-1min, and the power is 500-1000w / cm 2 .

[0028] The organic silicon leather described in the present invention was tested using the XFP-001 leather of Hubei Xingrui Silicon Materials as an example. For those skilled in the art, any organic silicon leather is within the protection scope of the applicant.

[0029] The light-curable silicone resin of the present invention has both high hardness and good flexibility, and has a relatively fast light-curing rate. In addition, it also has the characteristics of silicone materials, such as good weather resistance and harmlessness to the human body. It is suitable for use as a surface coating of silicone leather to improve its wear resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Cracking after wear resistance test, the highlighted area is the cracked part. DETAILED DESCRIPTION

[0031] In order to make those skilled in the art more clearly understand the technical solution of the present invention, the following embodiments are listed for further reference. It should be noted that the following examples do not limit the protection scope of the present invention.

[0032] Unless otherwise specified, the raw materials and reagents used in the following examples can be obtained from conventional commercial sources or by existing known methods.

[0033] The acrylic silane coupling agents are γ-methacryloxypropyltrimethoxysilane (LT-570) and LT-571 (γ-methacryloxypropylmethyldimethoxysilane) from New Blue Sky Company.

[0034] The polysiloxane containing acrylic acid at the terminal group is an acrylate-terminated silicone oil from Huaxiang Kejie Biotechnology Co., Ltd.

[0035] The photoinitiators were ethyl 2,4,6-trimethylbenzoylphenylphosphonate, diphenyl (2,4,6-trimethylphenylformyl) phosphine oxide, and 1-hydroxycyclohexyl phenyl ketone from Aladdin.

[0036] Example 1 Example A hyperbranched polysiloxane 1 containing acrylic acid in the side chain was prepared by the following steps: 100 parts of dimethyldimethoxysilane, 25 parts of acrylic silane coupling agent (LT-570) and 5 parts of acrylic silane coupling agent (LT-571) were added into a reaction container and mixed evenly, then the temperature was raised to 80°C, 120 parts of dilute hydrochloric acid (0.5 mol / L) were added dropwise, and the mixture was reacted for 3 hours. After neutralization, washing, drying and desulfurization, 8000 parts of dimethylsiloxane mixed ring body were added, the mixture was reacted at 70°C for 12 hours, and filtered and desulfurized to obtain a hyperbranched polysiloxane 1 containing acrylic acid in the side chain, with a viscosity of 1800 cps and a mass fraction of acrylic acid group-containing segments of 5%.

[0037] Example 2 Example A photocurable silicone resin 1 was prepared using a hyperbranched polysiloxane containing acrylic acid in the side chain as prepared in Example 1, and the specific steps were as follows: The light-curable silicone resin is composed of the following components in parts by weight: 10 parts of hyperbranched polysiloxane containing acrylic acid in the side chain, 20 parts of polysiloxane containing acrylic acid in the terminal group, 70 parts of isobornyl acrylate, and 0.2 parts of photoinitiator ethyl 2,4,6-trimethylbenzoylphenylphosphonate.

[0038] The preparation method is as follows: hyperbranched polysiloxane containing acrylic acid on the side chain, polysiloxane containing acrylic acid on the terminal group, isobornyl acrylate, and a photoinitiator are sequentially added into a reaction kettle, dispersed at 100 r / min for 1 hour, and vacuumed and defoamed for 15 minutes to obtain a photocurable silicone resin 1.

[0039] Pour the light-curing silicone resin 1 into the mold, apply it on the surface of the silicone leather, and irradiate it under a 365nm UV lamp for 1 min under nitrogen protection with a power of 800 w / cm 2 , and its performance is shown in Table 1.

[0040] Example 3 Example A photocurable silicone resin 2 was prepared using a hyperbranched polysiloxane containing acrylic acid in the side chain as prepared in Example 1, and the specific steps were as follows: The light-curable silicone resin is composed of the following components in parts by weight: 20 parts of hyperbranched polysiloxane containing acrylic acid in the side chain, 20 parts of polysiloxane containing acrylic acid in the terminal group, 60 parts of isobornyl acrylate, and 0.2 parts of photoinitiator diphenyl (2,4,6-trimethylphenylformyl) phosphine oxide.

[0041] The preparation method is as follows: hyperbranched polysiloxane containing acrylic acid on the side chain, polysiloxane containing acrylic acid on the end group, isobornyl acrylate, and a photoinitiator are sequentially added into a reaction kettle, dispersed at 100 r / min for 1 hour, and vacuumed and defoamed for 15 minutes to obtain a photocurable silicone resin 2.

[0042] Pour the light-curable silicone resin 2 into the mold and coat it on the surface of the silicone leather. Irradiate it under a 365nm UV lamp for 1 min at a power of 800 w / cm 2 , and its performance is shown in Table 1.

[0043] Comparative Example 1 A photocurable silicone resin 3 was prepared in the comparative example, and the specific steps were as follows: The light-curable silicone resin is composed of the following components in parts by weight: 20 parts of polysiloxane containing acrylic acid at the terminal group, 70 parts of isobornyl acrylate, and 0.2 parts of photoinitiator 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester.

[0044] The preparation method is as follows: polysiloxane containing acrylic acid at the end group, isobornyl acrylate and a photoinitiator are sequentially added into a reaction kettle, dispersed at 100 r / min for 1 hour, and vacuumed and defoamed for 15 minutes to obtain a photocurable silicone resin 3.

[0045] The photocurable silicone resin 3 was poured into the mold and coated on the surface of the silicone leather. It was irradiated under a 365nm UV lamp for 1 min under nitrogen protection with a power of 800 w / cm2. Its properties are shown in Table 1.

[0046] Comparative Example 2 A photocurable silicone resin 4 was prepared in the comparative example, using the hyperbranched polysiloxane containing acrylic acid in the side chain as prepared in Example 1, and the specific steps were as follows: The light-curable silicone resin is composed of the following components in parts by weight: 10 parts of hyperbranched polysiloxane containing acrylic acid in the side chain, 20 parts of polysiloxane containing acrylic acid in the terminal group, 70 parts of isobornyl acrylate, and 2 parts of photoinitiator ethyl 2,4,6-trimethylbenzoylphenylphosphonate.

[0047] The preparation method is as follows: hyperbranched polysiloxane containing acrylic acid on the side chain, polysiloxane containing acrylic acid on the end group, isobornyl acrylate, and a photoinitiator are sequentially added into a reaction kettle, dispersed at 100 r / min for 1 hour, and vacuumed and defoamed for 15 minutes to obtain a photocurable silicone resin 4.

[0048] The photocurable silicone resin 4 was poured into the mold and coated on the surface of the silicone leather. It was irradiated under a 365nm UV lamp for 1 min under nitrogen protection with a power of 800 w / cm2. Its properties are shown in Table 1.

[0049] Example 4 Example A hyperbranched polysiloxane 2 containing acrylic acid in the side chain was prepared by the following steps: 100 parts of dimethyldimethoxysilane and 20 parts of acrylic silane coupling agent LT-570 were added into a reaction container and mixed evenly, then the temperature was raised to 70°C, 120 parts of dilute hydrochloric acid (0.1 mol / L) were added dropwise, and the mixture was reacted for 2 hours. After neutralization, washing, drying and desulfurization, 1600 parts of dimethylsiloxane mixed ring bodies were added, and the mixture was reacted at 60°C for 5 hours. After filtering and desulfurization, a hyperbranched polysiloxane 2 containing acrylic acid in the side chain was obtained, with a viscosity of 15000 cps and a mass fraction of acrylic acid group chain segments of 1%.

[0050] Example 5 Example A photocurable silicone resin 5 was prepared using a hyperbranched polysiloxane containing acrylic acid in the side chain as prepared in Example 4, and the specific steps were as follows: The light-curable silicone resin is composed of the following components in parts by weight: 10 parts of hyperbranched polysiloxane containing acrylic acid in the side chain, 30 parts of polysiloxane containing acrylic acid in the terminal group, 60 parts of isobornyl acrylate, 0.4 parts of photoinitiator 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester, and 0.2 parts of photoinitiator 1-hydroxycyclohexyl phenyl ketone.

[0051] The preparation method is as follows: hyperbranched polysiloxane containing acrylic acid on the side chain, polysiloxane containing acrylic acid on the terminal group, isobornyl acrylate, and a photoinitiator are sequentially added into a reaction kettle, dispersed at 100 r / min for 1 hour, and vacuumed and defoamed for 15 minutes to obtain a photocurable silicone resin 5.

[0052] Pour the light-curable silicone resin 5 into the mold and coat it on the surface of the silicone leather. Irradiate it under a 365nm UV lamp for 1 min at a power of 800 w / cm 2 , and its performance is shown in Table 1.

[0053] Comparative Example 3 A photocurable silicone resin 6 was prepared in the comparative example, using the hyperbranched polysiloxane containing acrylic acid in the side chain as prepared in Example 1, and the specific steps were as follows: The light-curable silicone resin is composed of the following components in parts by weight: 40 parts of hyperbranched polysiloxane containing acrylic acid in the side chain, 40 parts of polysiloxane containing acrylic acid in the terminal group, 20 parts of isobornyl acrylate, 0.4 parts of photoinitiator 2,4,6-trimethylbenzoylphenylphosphonic acid ethyl ester, and 0.2 parts of photoinitiator 1-hydroxycyclohexyl phenyl ketone.

[0054] The preparation method is as follows: hyperbranched polysiloxane containing acrylic acid on the side chain, polysiloxane containing acrylic acid on the end group, isobornyl acrylate, and a photoinitiator are sequentially added into a reactor, dispersed at 100 r / min for 1 h, and vacuumed and defoamed for 15 min to obtain a photocurable silicone resin 6.

[0055] Pour the light-curable silicone resin 6 into the mold and coat it on the surface of the silicone leather. Irradiate it under a 365 nm UV lamp for 1 min at a power of 800 w / cm under nitrogen protection. 2 , and its performance is shown in Table 1.

[0056] Test Example 1 The photocurable silicone resin obtained in the embodiment and the comparative example was coated on the surface of the homemade silicone leather with a thickness of 20 μm and irradiated under a 365 nm ultraviolet lamp for 1 min under nitrogen protection with a power of 800 w / cm2. Its properties are shown in Table 1.

[0057] The test standards are: Abrasion resistance: ISO 11640.

[0058] Flexibility: Visual inspection.

[0059] The detection method is as follows: Abrasion resistance: Use a leather friction color fastness tester and refer to ISO11640 standard to test the abrasion resistance. The test results are graded according to the following abrasion resistance times: 45,000 times for level 6, 25,000 times for level 5, 12,000 times for level 4, 6,000 times for level 3, 2,200 times for level 2, and 600 times for level 1. Flexibility: Visual inspection: After 45,000 cycles of abrasion resistance test, observe whether the surface has cracks.

[0060] Test Example 2 The photocurable silicone resin obtained in the embodiment and the comparative example was poured into a mold with a thickness of 2.0 mm and irradiated under a 365 nm ultraviolet lamp for 1 min under nitrogen protection with a power of 800 w / cm2. The properties are shown in Table 1. The cracking conditions are shown in Table 1. Figure 1 shown.

[0061] The test standards are: Strength, elongation at break: GB / T2567-2021 Hardness: ASTM D2240-05 The detection method is as follows: Strength and elongation at break are tested using a tensile testing machine in accordance with GB / T2567-2021. Hardness is tested using a Shore A durometer in accordance with ASTM D2240-05.

[0062] Table 1 .

Claims

1. A method for preparing a hyperbranched polysiloxane containing acrylic acid in the side chain, characterized in that: The steps include: Dimethyldimethoxysilane and acrylic silane coupling agent are mixed evenly, and then the temperature is raised to 70-80°C, and diluted hydrochloric acid is added dropwise. After neutralization reaction, washing, drying and desulfurization are completed, dimethylsiloxane mixed ring body is added, and then reacted at 60-80°C. After the reaction is completed, the hyperbranched polysiloxane containing acrylic acid on the side chain is obtained by filtering and desulfurization.

2. The method for preparing a hyperbranched polysiloxane containing acrylic acid in the side chain according to claim 1, characterized in that: The acrylic silane coupling agent is at least one of LT-570 and LT-571 produced by New Blue Sky Company.

3. The method for preparing a hyperbranched polysiloxane containing acrylic acid in the side chain according to claim 2, characterized in that: In the raw materials, the mass fractions of dimethyldimethoxysilane, acrylic silane coupling agent and dimethylsiloxane mixed ring body are 100-150 parts, 20-30 parts and 1600-8000 parts respectively.

4. The method for preparing a hyperbranched polysiloxane containing acrylic acid in the side chain according to any one of claims 1 to 3, characterized in that: The prepared hyperbranched polysiloxane containing acrylic acid in the side chain has a viscosity between 1800 cps and 15000 cps, and a mass fraction of the chain segments containing acrylic acid groups is between 1% and 5%.

5. A photocurable silicone resin material, characterized in that: The invention relates to a hyperbranched polysiloxane having acrylic acid in the side chain, which is prepared by the method according to any one of claims 1 to 4.

6. The photocurable silicone resin material according to claim 5, characterized in that: The photocurable organic silicon resin material comprises 10-20 parts of hyperbranched polysiloxane containing acrylic acid in the side chain, 20-40 parts of polysiloxane containing acrylic acid in the terminal group, 50-70 parts of isobornyl acrylate and 0.2-0.6 parts of a photoinitiator.

7. The photocurable silicone resin material according to claim 6, characterized in that: The structure of the polysiloxane containing acrylic acid at the end group is: Wherein R1 and R2 are one of acrylate group and hydroxyl group, and each terminal polysiloxane containing acrylic acid contains at least one acrylate group, and n makes its viscosity in the range of 50-200 cps.

8. The photocurable silicone resin material according to claim 6, characterized in that: The photoinitiator used is one or more of ethyl 2,4,6-trimethylbenzoylphenylphosphonate, diphenyl (2,4,6-trimethylphenylformyl) phosphine oxide, and 1-hydroxycyclohexyl phenyl ketone.

9. The photocurable silicone resin material according to claim 8, characterized in that: The photocurable silicone resin material further comprises auxiliary agents, which include polymerization inhibitors, essences, rheological agents and anti-yellowing agents.

10. A silicone resin material for silicone leather surface coating, characterized in that: The photocurable silicone resin material according to any one of claims 5 to 9 is used.

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