A wear-resistant hand feel coating, and a preparation method and application thereof

Abstract

The application discloses a wear-resistant touch coating, which comprises a high-hydroxyl-content hyperbranched silicon-modified saturated polyester resin, a low-hydroxyl-content silicon-modified saturated polyester resin, a siloxane coupling agent, a blocked isocyanate curing agent, silica matting powder, polytetrafluoroethylene wax powder, an organic solvent and a catalyst. The application further discloses a preparation method of the wear-resistant touch coating and application of the wear-resistant touch coating in silica gel products. The high-hydroxyl-content hyperbranched silicon-modified saturated polyester resin, the low-hydroxyl-content silicon-modified saturated polyester resin and the siloxane coupling agent are reasonably matched, so that the coating product has good adhesion to silica gel substrates with low surface energy, excellent wear resistance and delicate and smooth touch.

Description

Technical Field

[0001] This invention relates to the field of coatings, and more particularly to an environmentally friendly, wear-resistant, and texture-feeling coating, its preparation method, and its application on the surface of silicone products. Background Technology

[0002] Silicone possesses excellent heat resistance, cold resistance, electrical insulation, and fatigue resistance, making it widely used in electronic product remote controls, car audio systems, keyboards, and instrument button presses. Due to its low surface energy and high touch frequency during use, traditional polysiloxane tactile oils applied to silicone buttons are easily worn away, losing their protective effect in a short time. Furthermore, conventional PU coatings are difficult to adhere to silicone materials.

[0003] On the other hand, silicone button products are used frequently, requiring coatings to provide superior wear resistance to ensure a good feel and appearance over a long period of time. Currently available polysiloxane feel oils have an RCA performance of less than 50 cycles, which is insufficient to meet daily use needs. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a wear-resistant, hand-feeling coating, its preparation method and application.

[0005] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0006] A wear-resistant, tactile coating, comprising the following components by weight:

[0007] 20-40 parts of hyperbranched silicon-modified polyester resin with high hydroxyl content,

[0008] 10-20 parts of low-hydroxyl content silicone-modified saturated polyester resin,

[0009] 1-3 parts of siloxane coupling agent

[0010] 10-20 parts of blocked isocyanate curing agent

[0011] 5-10 parts silica matting agent,

[0012] 0.5–2 parts polytetrafluoroethylene wax powder,

[0013] 20-40 parts organic solvent,

[0014] 0.5 to 2 parts catalyst.

[0015] Preferably, in the aforementioned wear-resistant coating, the high-hydroxyl content hyperbranched silicon-modified saturated polyester resin has an effective hydroxyl content of 4-6%, a resin solid content of 40-80%, and a viscosity of 2000-5000 cps.

[0016] Preferably, in the aforementioned wear-resistant coating, the effective hydroxyl content of the low-hydroxyl content silicone-modified saturated polyester resin is 1-3%, the resin solid content is 40-60%, and the viscosity is 1500-4000 cps.

[0017] In the aforementioned wear-resistant coating, preferably, the organic solvent is one or more of ethyl acetate, butyl acetate, and methyl isobutyl ketone.

[0018] In the aforementioned wear-resistant coating, preferably, the blocked isocyanate curing agent is at least one of an aliphatic blocked isocyanate curing agent or an aromatic blocked isocyanate curing agent.

[0019] In the aforementioned wear-resistant coating, preferably, the catalyst is an organobismuth compound, which can accelerate the reaction between polyester resin and isocyanate, and does not contain organotin compounds that are harmful to the human body.

[0020] Preferably, in the aforementioned wear-resistant, feel-enhancing coating, the silica matting powder is a wax-treated silica matting powder. Wax-treated silica matting powder has a small particle size, making it easy to disperse in the coating system. While providing an excellent feel, it can significantly reduce the surface friction coefficient of the coating, improving scratch resistance, anti-blocking properties, and other characteristics.

[0021] In the aforementioned abrasion-resistant coatings, wax-treated silica provides a smooth feel while improving the RCA (paper tape abrasion resistance) of the product.

[0022] As a general inventive concept, the present invention also provides a method for preparing the above-mentioned wear-resistant and tactile coating, comprising the following steps:

[0023] (1) Hyperbranched silicon-modified saturated polyester resin with high hydroxyl content, silicon-modified saturated polyester resin with low hydroxyl content, blocked isocyanate curing agent, drying agent, siloxane coupling agent and organic solvent are added to the dispersant for pre-dispersion.

[0024] (2) Continue to stir the pre-dispersed material in step (1), and add silica matting powder and polytetrafluoroethylene wax powder while stirring. After the material is evenly dispersed, the wear-resistant and hand-feel coating is obtained.

[0025] In the above preparation method, preferably, in step (1), the pre-dispersion refers to stirring at a speed of 600-1000 r / min for 5-10 min;

[0026] In step (2), dispersion refers to stirring at a stirring rate of 1200-2000 r / min for 20-30 min.

[0027] As a general inventive concept, the present invention also provides the application of the above-described abrasion-resistant coating or the abrasion-resistant coating prepared by the above-described preparation method in silicone products.

[0028] Compared with the prior art, the advantages of the present invention are as follows:

[0029] (1) The present invention rationally combines a high-hydroxyl-content hyperbranched silicon-modified saturated polyester resin, a low-hydroxyl-content silicon-modified saturated polyester resin, and a siloxane coupling agent to make the coating product have good adhesion to silicone substrates with low surface energy, excellent wear resistance, and a delicate and smooth feel.

[0030] (2) The wear-resistant coating of the present invention uses wax-treated fumed silica and polytetrafluoroethylene wax powder, which can work together to make the product feel more delicate and smooth and have excellent wear resistance.

[0031] (3) The wear-resistant coating of the present invention is stable when stored at room temperature and can undergo a rapid cross-linking reaction during baking. The process is simple to apply and does not require the addition of a curing agent. It can be fully cured by baking at 130-150℃ for 60 minutes.

[0032] (4) The wear-resistant coating of the present invention has excellent aging resistance. Detailed Implementation

[0033] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0034] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0035] Unless otherwise specified, all reagents and raw materials used in this invention are commercially available products or products that can be prepared by known methods.

[0036] The performance testing criteria in the following embodiments are:

[0037] Adhesion test: The coating product is sprayed onto the silicone substrate. After curing, the adhesion is tested in accordance with GB / T 9286-1998 "Cross-cut test of paint and varnish film".

[0038] Abrasion resistance test: A paper tape abrasion tester with a 175-gram load was used for the test.

[0039] Boiling water test: Immerse in boiling water for 120 minutes, observe the surface condition of the coating and test the adhesion.

[0040] Xenon lamp aging test: ultraviolet light wavelength 420nm, light intensity 0.80W / m 2 After storing under certain conditions for a certain period of time, observe the condition of the coating surface.

[0041] Thermal shock test: After storing at -40℃ for 12 hours, then at 80℃ for 12 hours, this constitutes one cycle. A total of 10 cycles are performed, and the surface condition of the coating is observed.

[0042] Salt spray test: Spray neutral salt spray continuously for a period of time and observe the changes in appearance and adhesion.

[0043] In the following examples, the high-hydroxyl-content hyperbranched silicon-modified saturated polyester resin used was Hubei Changyao SJ-803, with an effective hydroxyl content of approximately 5.5%, a resin solid content of approximately 75%, and a viscosity of approximately 3000 cps; the low-hydroxyl-content silicon-modified saturated polyester resin used was Anhui Sanjin New Materials SJ-1088, with an effective hydroxyl content of approximately 1.5%, a resin solid content of approximately 50%, and a viscosity of approximately 2500 cps; the blocked isocyanate curing agent was Degussa B1358A, the silane coupling agent was Dow Corning Z-6020, the organic bismuth catalyst was Guangzhou Yourun Synthetic Materials Co., Ltd.'s BCAT-16A, the polytetrafluoroethylene wax powder was Lubrizol 1780, and the wax-treated silica matting agent was Grace's SYLOID 7000.

[0044] The formulations of the wear-resistant, hand-feel coatings for each embodiment are shown in Table 1.

[0045] Table 1. Formulations of the abrasion-resistant, soft-feel coatings in Examples 1-5 (unit: parts by weight)

[0046]

[0047]

[0048] The preparation method of the wear-resistant, soft-feel coating in the embodiments includes the following steps:

[0049] (1) High-hydroxyl content hyperbranched silicon-modified saturated polyester resin, low-hydroxyl content silicon-modified saturated polyester resin, blocked isocyanate curing agent, drying agent, siloxane coupling agent and organic solvent are added to the dispersant and stirred at 800 r / min for 10 min for pre-dispersion.

[0050] (2) Continue to stir the pre-dispersed material in step (1) at a stirring rate of 1200 r / min for 30 min. While stirring, add silica matting powder and polytetrafluoroethylene wax powder. After uniform dispersion, a wear-resistant feel coating is obtained.

[0051] The prepared abrasion-resistant coating can be fully cured by baking at 140°C for 60 minutes.

[0052] Comparative Example 1:

[0053] The difference between this comparative example and Example 1 is that polytetrafluoroethylene wax powder is not added, while other raw materials and processes remain the same as in Example 1.

[0054] Comparative Example 2:

[0055] The difference between this comparative example and Example 1 is that the hyperbranched silicon-modified polyester resin with high hydroxyl content in Example 1 is replaced with an equal part by weight of silicon-modified polyester resin with low hydroxyl content. That is, this comparative example does not use silicon-modified saturated polyester with high hydroxyl content, and the total part by weight of silicon-modified polyester resin with low hydroxyl content is 40 parts. Other raw materials and processes are the same as in Example 1.

[0056] Comparative Example 3:

[0057] The difference between this comparative example and Example 1 is that the low-hydroxyl content silicone-modified polyester resin in Example 1 is replaced with an equal weight of high-hydroxyl content hyperbranched silicone-modified polyester resin. That is, this comparative example does not use low-hydroxyl content silicone-modified polyester resin, and the total weight of high-hydroxyl content hyperbranched silicone-modified polyester resin is 40 parts. Other raw materials and processes are the same as in Example 1.

[0058] Examples 1-5 and Comparative Examples 1-3 were subjected to adhesion and RCA abrasion tests, as well as boiling water tests, aging tests, thermal shock tests, and salt spray tests. The results are shown in Table 2.

[0059] Table 2 Performance test results of Examples 1-5 and Comparative Examples 1-3

[0060]

Claims

1. A wear-resistant, tactile coating for use in silicone products, characterized in that, Based on parts by weight, it comprises the following components: 20-40 parts of hyperbranched silicon-modified saturated polyester resin with high hydroxyl content, wherein the effective hydroxyl content of the hyperbranched silicon-modified saturated polyester resin is 4-6%, the resin solid content is 40-80%, and the viscosity is 2000-5000 cps. 10-20 parts of a low-hydroxyl-content silicone-modified saturated polyester resin, wherein the effective hydroxyl content of the low-hydroxyl-content silicone-modified saturated polyester resin is 1-3%, the resin solid content is 40-60%, and the viscosity is 1500-4000 cps. 1-3 parts of siloxane coupling agent 10-20 parts of blocked isocyanate curing agent 5-10 parts of silica matting powder, wherein the silica matting powder is a wax-treated silica matting powder. 0.5–2 parts polytetrafluoroethylene wax powder, 20-40 parts organic solvent, 0.5 to 2 parts catalyst.

2. The wear-resistant, hand-feel coating as described in claim 1, characterized in that, The organic solvent is one or more of ethyl acetate, butyl acetate, and methyl isobutyl ketone.

3. The wear-resistant, hand-feel coating as described in claim 1, characterized in that, The blocked isocyanate curing agent is at least one of aliphatic blocked isocyanate curing agents or aromatic blocked isocyanate curing agents.

4. The wear-resistant, hand-feel coating as described in claim 1, characterized in that, The catalyst is an organobismuth compound.

5. A method for preparing a wear-resistant, tactile coating as described in any one of claims 1 to 4, characterized in that, Includes the following steps: (1) Hyperbranched silicon-modified saturated polyester resin with high hydroxyl content, silicon-modified saturated polyester resin with low hydroxyl content, blocked isocyanate curing agent, catalyst, siloxane coupling agent and organic solvent are added to the dispersant for pre-dispersion. (2) Continue to stir the pre-dispersed material in step (1), and add silica matting powder and polytetrafluoroethylene wax powder while stirring. After the material is evenly dispersed, the wear-resistant feel coating is obtained.

6. The preparation method according to claim 5, characterized in that, In step (1), the pre-dispersion is carried out by stirring at a speed of 600~1000 r / min for 5~10 min; In step (2), dispersion refers to stirring at a stirring rate of 1200~2000r / min for 20~30min.

7. The application of a wear-resistant, tactile coating as described in any one of claims 1 to 4, or a wear-resistant, tactile coating prepared by the preparation method as described in any one of claims 5 to 6, in silicone products.

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