Scratch-resistant water-based paint, method of preparation and use

Abstract

The present application belongs to the technical field of water-based paint for leather, and discloses a kind of scratch-resistant water-based paint, preparation method and use, the scratch-resistant water-based paint, by weight parts, including 80-110 parts water-based polyurethane acrylate resin, 0.5-1 parts silicon dioxide, 6-10 parts alumina, 0.1-1 parts silicon carbide micro powder, 0.1-0.3 parts stabilizer, 0.3-0.6 parts leveling agent, 0.3-0.6 parts defoaming agent;Wherein the particle size of the silicon dioxide is 20-40nm;The alumina is divided into first alumina and second alumina, and the weight ratio of the first alumina and the second alumina is 2-3:7-8, the particle size of the first alumina is 70-80nm, and the particle size of the second alumina is 10-15nm;The particle size of the silicon carbide micro powder is 10-15nm.The present application is based on the use of smaller particle size second alumina compounded with first alumina, by adding the same particle size of silicon carbide micro powder as the second alumina and compounding the specific particle size of silicon dioxide, which can produce a synergistic effect of improving the scratch resistance of water-based paint, and significantly improve the scratch resistance of water-based paint.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water-based paint for leather, in particular to a kind of scratch-resistant water-based paint, preparation method and use. BACKGROUND

[0002] The water-based paint for automotive leather mainly involves water-based leather paint and water-based polyurethane leather brightener. These products are widely used in automotive interior due to their environmental protection, safety and excellent mechanical properties.

[0003] However, due to the fact that automotive interior leather will face various possible scratching situations in daily use, including clothing friction, luggage dragging, hand touching and accidental collision, etc., these factors may cause damage to the surface of the leather, affecting the appearance and durability. Therefore, the scratch resistance of water-based paint is an important product performance requirement for automotive leather.

[0004] Prior art 1: Chinese patent application 202110004799.1 discloses a kind of water-based synthetic leather wear-resistant scratch-resistant polyurethane resin and its preparation method, which comprises the following weight parts of substances: polymeric diol 160-240 parts, polydiisocyanate 56-100 parts, carboxylic acid type small molecule diol 7.2-13.2 parts, hydroxyl type small molecule diol 6-10 parts, catalyst 0.2-0.4 parts, acetone 80-140 parts, sulfonate type diol 7-12 parts, neutralizing agent 4.1-6.8 parts, deionized water 550-820 parts, crosslinking modifier 4-8 parts, wetting agent 4-6 parts, leveling agent 4-6 parts.

[0005] Prior art 1 uses polycarbonate diol and adds polysiloxane modified polyurethane resin to improve the water resistance, acid and alkali resistance and surface smoothness of the resin coating, thereby improving its scratch resistance. The use of polycarbonate diol greatly improves the wear resistance compared to ordinary polyether diol, and the use of triamine crosslinking modifier enables the molecular structure to achieve network crosslinking, thereby improving the wear resistance and scratch resistance of the resin coating.

[0006] However, since polycarbonate diol is a crystalline body, it is difficult to operate when used to prepare water-based paint, increasing the production difficulty, and it also has poor low-temperature flexibility and texture, which can reduce the use experience and appearance of automotive leather, and is not very suitable for automotive leather.

[0007] Therefore, the development of water-based paint suitable for automotive leather with high scratch resistance is currently a research and development hotspot. SUMMARY

[0008] One of the purposes of the present invention is to provide a scratch-resistant water-based coating. By adding silica, alumina and silicon carbide micropowders of specific particle size and specific dosage, the stability, flexibility and scratch resistance of the water-based coating are effectively improved, and the coating has excellent texture when used for automotive leather.

[0009] Another object of the present invention is to provide a method for preparing a scratch-resistant water-based coating, wherein the scratch-resistant water-based coating prepared thereby has excellent scratch resistance, stability, flexibility and other properties.

[0010] At the same time, the present invention also provides an application of a scratch-resistant water-based coating, which, when used as a coating for automotive leather, can provide the automotive leather with excellent scratch resistance, flexibility and texture, thereby improving the user experience of the automotive leather.

[0011] To achieve the above object, the present invention provides a scratch-resistant water-based coating, comprising, by weight, 80-110 parts of a water-based polyurethane acrylate resin, 0.5-1 parts of silicon dioxide, 6-10 parts of aluminum oxide, 0.1-1 parts of silicon carbide micropowder, 0.1-0.3 parts of a stabilizer, 0.3-0.6 parts of a leveling agent, and 0.3-0.6 parts of a defoaming agent;

[0012] The particle size of the silicon dioxide is 20-40 nm;

[0013] The alumina is divided into a first alumina and a second alumina, the weight ratio of the first alumina to the second alumina is 2-3:7-8, the particle size of the first alumina is 70-80 nm, and the particle size of the second alumina is 10-15 nm;

[0014] The particle size of the silicon carbide micropowder is 10-15 nm.

[0015] Nano-scale silica can effectively improve the UV absorption capacity of water-based coatings, and can effectively improve the smoothness, anti-aging performance, self-cleaning performance, etc. of water-based coatings, and it can also improve the hardness, wear resistance, scratch resistance and weather resistance of the coatings;

[0016] The addition of aluminum oxide will also improve the performance of water-based coatings. As a high-performance filler, its addition to water-based coatings can significantly improve the performance of the coating. Specifically, the high hardness, high purity, and high transparency of aluminum oxide enable it to:

[0017] (1) Improve scratch resistance: The addition of aluminum oxide can significantly improve the scratch resistance of the product, making the paint film stronger and more resistant to external friction and wear.

[0018] (2) Enhanced wear resistance: The addition of aluminum oxide can greatly improve the wear resistance of the paint, making it more resistant to wear and reducing peeling and falling off during use.

[0019] (3) Improve hardness: By improving the structure of the paint, aluminum oxide helps to increase the hardness of the paint film, thereby enhancing the durability of the paint.

[0020] (4) Maintaining basic properties: Aluminum oxide has good dispersibility and will not chemically react with other material components when added to the coating, so it will not affect the basic properties of the material and the performance of other additives.

[0021] (5) Improve product performance: The addition of alumina helps improve the product's chemical resistance, high gloss and other properties while maintaining the basic properties of the coating unchanged.

[0022] (6) In addition, alumina can improve the fluidity of the coating, reduce viscosity, increase the solid content of the coating, and reduce the use of volatile organic compounds, thus contributing to environmental protection.

[0023] The choice of alumina particle size will affect the quality of automotive leather. The larger the particle size of alumina, the more obvious the improvement in the hardness, wear resistance and scratch resistance of water-based coatings. However, alumina with a large particle size will affect the texture of automotive leather, and alumina with a particle size that is too small will significantly reduce the improvement in the hardness, wear resistance and scratch resistance of water-based coatings.

[0024] In order to enable the water-based paint to maintain or even improve the user experience of automotive leather, the present invention only uses a small amount of first alumina with a larger particle size to improve the scratch resistance and wear resistance of the water-based paint; at the same time, the present invention also found that on the basis of using a second alumina with a smaller particle size to compound the first alumina, by adding silicon carbide micropowder with the same particle size as the second alumina and compounding it with silicon dioxide with a specific particle size, the scratch resistance of the water-based paint can be synergistically improved.

[0025] Preferably, the stabilizer includes an ultraviolet absorber and a light stabilizer, and the weight ratio of the ultraviolet absorber to the light stabilizer is 1-10:1-10.

[0026] More preferably, the weight ratio of the ultraviolet absorber to the light stabilizer is 1:4.

[0027] Preferably, the light stabilizer is a hindered amine light stabilizer.

[0028] Preferably, the ultraviolet absorber is one of ultraviolet absorber UV-9, ultraviolet absorber UV-531, and ultraviolet absorber UVP-327.

[0029] Preferably, the leveling agent is leveling agent SN4034.

[0030] Preferably, the defoaming agent is SN-6725.

[0031] Furthermore, the waterborne polyurethane acrylate resin in the scratch-resistant waterborne coating is a UV-cured waterborne polyurethane acrylate resin. Accordingly, the scratch-resistant waterborne coating further comprises 1-4 parts of a photoinitiator.

[0032] Preferably, the photoinitiator is at least one of 2-hydroxy-2-methyl-1-phenyl-1-propanone, 1-hydroxy-cyclohexyl phenyl ketone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide

[0033] The present invention also provides a method for preparing a scratch-resistant water-based coating, comprising the following steps:

[0034] Step 1: SiO2, a first aluminum oxide, a second aluminum oxide, and silicon carbide micropowder are mixed to obtain a mixed powder, and then an appropriate amount of a dispersant and deionized water are added to the mixed powder for grinding and dispersion to obtain a dispersed mixed powder;

[0035] Step 2: The remaining components and the dispersed mixed powder are mixed and stirred evenly to obtain a scratch-resistant water-based coating.

[0036] The dispersant is at least one of polyethylene glycol and sodium lauryl sulfate, and the amount of the dispersant is 2-5% of the mixed powder.

[0037] Specifically, the preparation method of the scratch-resistant water-based coating is:

[0038] Step 1: SiO2, a first aluminum oxide, a second aluminum oxide, and silicon carbide micropowder are mixed to obtain a mixed powder, and then an appropriate amount of a dispersant and deionized water are added to the mixed powder for grinding and dispersion to obtain a dispersed mixed powder;

[0039] Step 2: Homogenize and stir the waterborne polyurethane acrylate resin, stabilizer, leveling agent, defoamer, photoinitiator and dispersed mixed powder.

[0040] It should be noted that step 1 of the present invention is intended to fully disperse the nano-scale powder, so the amount of deionized water used is the same as in the prior art and is not particularly limited.

[0041] Preferably, the waterborne polyurethane acrylate resin can be commercially available waterborne polyurethane acrylate resin.

[0042] The present invention also provides an application of the scratch-resistant water-based coating, wherein the scratch-resistant water-based coating is used as a coating for automotive leather.

[0043] Beneficial effects

[0044] Compared with the prior art, the present invention has at least the following advantages:

[0045] (1) The present invention uses silicon dioxide to modify waterborne polyurethane acrylate resin, which can effectively improve the smoothness, anti-aging performance, self-cleaning performance, etc. of waterborne coatings, and improve the hardness, wear resistance, scratch resistance and weather resistance of the coatings;

[0046] (2) The present invention uses aluminum oxide to modify waterborne polyurethane acrylate resin, which can effectively improve the scratch resistance, wear resistance, hardness and other properties of the waterborne coating;

[0047] (3) The present invention ensures that the alumina can improve the scratch resistance of the water-based coating while avoiding the problem of a significant decrease in the texture and user experience of the automotive leather due to the excessively large alumina particle size by compounding the first alumina with the smaller particle size.

[0048] (4) Since the amount of the first alumina with a larger particle size is small, the improvement of the scratch resistance of the water-based coating by the combination of the first alumina and the second alumina is relatively limited. The present invention uses the second alumina with a smaller particle size to compound the first alumina. By adding silicon carbide micropowder with the same particle size as the second alumina and compounding it with silicon dioxide with a specific particle size, it can produce a synergistic effect of improving the scratch resistance of the water-based coating, thereby significantly improving the scratch resistance of the water-based coating. DETAILED DESCRIPTION

[0049] The present invention will be further described below in conjunction with the embodiments, but this does not constitute any limitation to the present invention. Any limited modifications made within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0050] In order to explain the technical content of the present invention in detail, further description will be given below in conjunction with the embodiments.

[0051] In the following examples and comparative examples, the waterborne polyurethane acrylate resin was purchased from the waterborne UV resin DR-W470 provided by Hubei Langbowan Biotechnology Co., Ltd., the hindered amine light stabilizer was purchased from the TINUVIN 783FDL long-term thermal stabilizer provided by Shanghai Jingyan Chemical Co., Ltd., the ultraviolet absorber UV-531 was purchased from Dongguan Xingyuan Chemical Co., Ltd., the leveling agent SN4034 and the defoaming agent SN-6725 were both purchased from Shanghai Shenzhu Chemical Technology Co., Ltd., and the photoinitiator was purchased from 2-hydroxy-2-methyl-1-phenyl-1-propanone provided by Shandong Xinghai Chemical Co., Ltd.

[0052] It should be noted that the technical solution of the present invention can be implemented through other commercially available products and is not limited to the above-mentioned manufacturers.

[0053] In the following examples and comparative examples, the particle sizes of the silica powder, the first alumina powder, the second alumina powder and the silicon carbide micropowder are obtained by sieving, which is a prior art and the specific steps are not described in detail.

[0054] Unless otherwise specified, the % and parts in the present application are weight percent and weight parts.

[0055] The following examples and comparative examples are prepared by the following steps to prepare the water-based paint:

[0056] Step 1: Mix the silica, the first alumina, the second alumina and the silicon carbide micropowder to obtain a mixed powder, then add an appropriate amount of dispersant and deionized water to the mixed powder for grinding and dispersing to obtain a dispersed mixed powder;

[0057] Step 2: Homogenize and mix the remaining components with the dispersed mixed powder.

[0058] Example 1

[0059] A scratch-resistant water-based paint, comprising 80 parts of water-based polyurethane acrylate resin, 0.6 parts of silica powder with a particle size of 20-40 nm, 1.2 parts of first alumina powder with a particle size of 70-80 nm, 4.8 parts of second alumina powder with a particle size of 10-15 nm, 0.3 parts of silicon carbide micropowder with a particle size of 10-15 nm, 0.02 parts of hindered amine light stabilizer, 0.08 parts of ultraviolet absorber UV-531, 0.4 parts of leveling agent, 0.3 parts of defoaming agent, and 3 parts of photoinitiator.

[0060] Example 2

[0061] A scratch-resistant water-based paint, comprising 110 parts of water-based polyurethane acrylate resin, 1 part of silica powder with a particle size of 20-40 nm, 3 parts of first alumina powder with a particle size of 70-80 nm, 7 parts of second alumina powder with a particle size of 10-15 nm, 1 part of silicon carbide micropowder with a particle size of 10-15 nm, 0.02 parts of hindered amine light stabilizer, 0.08 parts of ultraviolet absorber UV-531, 0.4 parts of leveling agent, 0.3 parts of defoaming agent, and 3 parts of photoinitiator.

[0062] Example 3

[0063] A scratch-resistant water-based paint, comprising 95 parts of water-based polyurethane acrylate resin, 0.6 parts of silica powder with a particle size of 20-40 nm, 1.6 parts of first alumina powder with a particle size of 70-80 nm, 6.4 parts of second alumina powder with a particle size of 10-15 nm, 0.8 parts of silicon carbide micropowder with a particle size of 10-15 nm, 0.02 parts of hindered amine light stabilizer, 0.08 parts of ultraviolet absorber UV-531, 0.4 parts of leveling agent, 0.3 parts of defoaming agent, and 3 parts of photoinitiator.

[0064] Comparative Example 1

[0065] A scratch-resistant water-based coating comprises 95 parts of a water-based polyurethane acrylate resin, 0.6 parts of silicon dioxide powder with a particle size of 20-40 nm, 1.6 parts of a first aluminum oxide powder with a particle size of 70-80 nm, 6.4 parts of a second aluminum oxide powder with a particle size of 10-15 nm, 0.02 parts of a hindered amine light stabilizer, 0.08 parts of an ultraviolet absorber UV-531, 0.4 parts of a leveling agent, 0.3 parts of a defoaming agent, and 3 parts of a photoinitiator.

[0066] Comparative Example 2

[0067] A scratch-resistant water-based coating comprises 95 parts of a water-based polyurethane acrylate resin, 0.6 parts of silicon dioxide powder with a particle size of 20-40 nm, 1.6 parts of a first aluminum oxide powder with a particle size of 70-80 nm, 7.2 parts of a second aluminum oxide powder with a particle size of 10-15 nm, 0.02 parts of a hindered amine light stabilizer, 0.08 parts of an ultraviolet absorber UV-531, 0.4 parts of a leveling agent, 0.3 parts of a defoaming agent, and 3 parts of a photoinitiator.

[0068] Comparative Example 3

[0069] It is generally the same as Example 3, except that the particle size of the second aluminum oxide is 20-40 nm.

[0070] Comparative Example 4

[0071] It is generally the same as Example 3, except that the particle size of the first aluminum oxide is 20-40 nm.

[0072] Comparative Example 5

[0073] It is generally the same as Example 3, except that the particle size of the first aluminum oxide is 10-15 nm.

[0074] Comparative Example 6

[0075] It is generally the same as Example 3, except that the particle size of the silicon carbide powder is 20-40 nm.

[0076] Comparative Example 7

[0077] It is generally the same as Example 3, except that the particle size of the silicon carbide micropowder is 3-8 nm.

[0078] Comparative Example 8

[0079] It is generally the same as Example 3, except that the particle size of the second aluminum oxide is 3-8 nm.

[0080] Performance Testing

[0081] The water-based coatings obtained in Examples 1-3 and Comparative Examples 1-8 were sprayed on PVC artificial leather and cured, and then the surface of the PVC artificial leather was rubbed back and forth once using a five-finger scratch tester under pressure conditions of 10N, 12N, 15N, and 20N, respectively. Each test was performed on a new piece of PVC artificial leather sprayed and cured with the water-based coating. The surfaces of the PVC artificial leathers sprayed with the water-based coatings obtained in Examples 1-3 and Comparative Examples 1-8 were observed for damage and color difference. The results are shown in Table 1.

[0082] It should be noted that if the PVC artificial leather is damaged when tested under conditions of lower pressure, no further testing under higher pressure will be performed.

[0083] Table 1 Scratch resistance results of water-based coatings obtained in Examples 1-3 and Comparative Examples 1-8

[0084]

[0085]

[0086] According to the results in Table 1, we can see that:

[0087] According to the data of Examples 1-3, the present invention can effectively improve the scratch resistance of water-based coatings by compounding silicon dioxide of specific particle size, first aluminum oxide, second aluminum oxide and silicon carbide powder.

[0088] According to the data comparison of Example 3 and Comparative Examples 1 and 2, it can be seen that in Comparative Examples 1 and 2, when silicon carbide powder is not added, the scratch resistance of the water-based coating decreases significantly. In Comparative Example 2, silicon carbide powder is added to the second alumina, but its scratch resistance is not significantly improved compared with Comparative Example 1. The reason is that the second alumina powder with a small particle size has a very limited effect on improving the scratch resistance of the water-based coating, and the addition of a small amount cannot effectively improve the scratch resistance of the water-based coating. It can be seen that the addition of silicon carbide powder of the present invention is particularly critical, and it can synergistically improve the scratch resistance of the water-based coating with silicon dioxide, the first alumina, and the second alumina.

[0089] According to the data comparison between Example 3 and Comparative Examples 3, 6, 7 and 8, although Comparative Example 3 increases the particle size of the second alumina, the scratch resistance of the water-based coating is reduced. Similarly, Comparative Example 7 reduces the particle size of the silicon carbide micropowder. In theory, the smaller the particle size of the silicon carbide micropowder, the better the performance optimization of the water-based coating. However, Comparative Examples 3 and 7 respectively use the second alumina and silicon carbide micropowder, which theoretically improve the scratch resistance of the water-based coating, but the scratch resistance of the water-based coating is reduced. It is speculated that the reason may be that the present invention adds silicon carbide micropowder with the same particle size range as the second alumina. During the curing and molding process of the water-based coating, silicon dioxide, the first alumina and the second alumina are added. Aluminum dioxide forms a specific structure, and in the process, silicon carbide micropowder replaces part of the structural position of the second aluminum oxide, thereby forming a new structure, which synergistically improves the scratch resistance of the water-based coating, greatly improving the scratch resistance of the water-based coating; Comparative Examples 3 and 7 make the particle sizes of the second aluminum oxide and silicon carbide micropowder different, which makes it difficult for silicon carbide micropowder to replace part of the second aluminum oxide to produce a new stable structure; similarly, Comparative Examples 6 and 8 also lead to the same results, and because the particle size selection of silicon carbide micropowder and the particle size selection of the second aluminum oxide are worse, the simple component efficacy superposition effect produced by Comparative Examples 6 and 8 is worse, and the scratch resistance of their water-based coatings is lower than that of Comparative Examples 3 and 7.

[0090] According to the data comparison of Example 3 and Comparative Examples 4 and 5, it can be seen that the particle size selection of the first aluminum oxide will also seriously affect the scratch resistance performance of the water-based coating. It is speculated that the possible reason is: in the technical solution of the present invention, a first aluminum oxide and silicon dioxide are used as the basis, and then the second aluminum oxide and silicon carbide micropowder are compounded to form a stable structure, thereby synergistically improving the scratch resistance of the water-based coating.

[0091] The embodiments presented herein are merely embodiments selected from a combination of all possible embodiments. The appended claims should not be limited by the embodiments describing the present invention. Some numerical ranges used in the claims include subranges therein, and variations in these ranges should also be covered by the appended claims.

Claims

1. A scratch-resistant water-based coating, characterized in that: In parts by weight, it comprises 80-110 parts of waterborne polyurethane acrylate resin, 0.5-1 parts of silicon dioxide, 6-10 parts of aluminum oxide, 0.1-1 parts of silicon carbide micropowder, 0.1-0.3 parts of stabilizer, 0.3-0.6 parts of leveling agent, and 0.3-0.6 parts of defoaming agent; The particle size of the silicon dioxide is 20-40 nm; The alumina is divided into a first alumina and a second alumina, the weight ratio of the first alumina to the second alumina is 2-3:7-8, the particle size of the first alumina is 70-80 nm, and the particle size of the second alumina is 10-15 nm; The particle size of the silicon carbide micropowder is 10-15 nm.

2. The scratch-resistant water-based coating according to claim 1, characterized in that: The stabilizer includes an ultraviolet absorber and a light stabilizer, and the weight ratio of the ultraviolet absorber to the light stabilizer is 1-10:1-10.

3. The scratch-resistant water-based coating according to claim 2, characterized in that: The light stabilizer is a hindered amine light stabilizer.

4. The scratch-resistant water-based coating according to claim 2, characterized in that: The ultraviolet absorber is one of ultraviolet absorber UV-9, ultraviolet absorber UV-531 and ultraviolet absorber UVP-327.

5. The scratch-resistant water-based coating according to claim 1, characterized in that: Also includes 1-4 parts of photoinitiator.

6. A method for preparing the scratch-resistant water-based coating according to any one of claims 1 to 5, characterized in that: The steps include: Step 1: mixing silicon dioxide, a first aluminum oxide, a second aluminum oxide and silicon carbide micropowder to obtain a mixed powder, then adding an appropriate amount of dispersant and deionized water to the mixed powder for grinding and dispersion to obtain a dispersed mixed powder; Step 2: The remaining components and the dispersed mixed powder are mixed and stirred evenly to obtain a scratch-resistant water-based coating.

7. A use of the scratch-resistant water-based coating according to any one of claims 1 to 5, characterized in that: The scratch-resistant water-based paint is used as a coating for automotive leather.

Images