Coating for automobile trim strip and use thereof

Abstract

The application relates to the field of automobile decoration products, and particularly discloses a coating for automobile decoration strips and application thereof. The coating for automobile decoration strips comprises a base material and a protective material, and the protective material comprises the following raw materials in parts by weight: 20-30 parts of water-based acrylic resin, 10-15 parts of isocyanate, 5-10 parts of light calcium carbonate, 10-15 parts of barium sulfate and 1-3 parts of polyacrylic acid sodium. The coating for automobile decoration strips is crosslinked by using the water-based acrylic resin and the isocyanate, so that the coating has rigidity and toughness, the phenomenon that the coating is prone to cracking and falling off can be reduced, and meanwhile, the light calcium carbonate, the barium sulfate and the polyacrylic acid sodium are combined, so that the coating has a smooth mirror surface effect and gloss.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automobile decoration products, more particularly, it relates to a coating for automobile decoration strip and application thereof. BACKGROUND

[0002] The automobile decoration strip is a kind of decoration accessory applied on the automobile, which can be used to decorate the positions such as the window, door frame and chassis edge of the automobile. The stainless steel is widely applied in the automobile industry due to its high hardness, corrosion resistance and non-deformation advantages, which gives people a sense of luxury and nobility. With the increasing demand for high-grade materials and decoration diversification, the requirements for the stainless steel decoration strip are gradually increasing.

[0003] In actual use, a layer of finish paint is often coated on the surface of the stainless steel to meet the requirements of gloss, corrosion resistance and weather resistance. However, when the stainless steel decoration strip is used on the vehicle, the finish paint is often damaged due to long-term exposure to the outdoors, and cracking, loss of gloss and other phenomena occur, which leads to the decrease of the gloss, corrosion resistance and other properties of the stainless steel decoration strip, SUMMARY

[0004] In order to improve the gloss, weather resistance and other properties of the stainless steel decoration strip substrate, the present application provides a coating for automobile decoration strip and application thereof.

[0005] In the first aspect, the present application provides a coating for automobile decoration strip, which adopts the following technical solution:

[0006] The coating for automobile decoration strip comprises a base material and a protective material, and the protective material comprises the following raw materials by weight: 20-30 parts of water-based acrylic resin, 10-15 parts of isocyanate, 5-10 parts of light calcium carbonate, 10-15 parts of barium sulfate and 1-3 parts of polyacrylic acid sodium.

[0007] By using the above technical solution, the base material and the protective material are used to double-protect the automobile decoration strip, reducing the cracking and falling off of the surface coating of the automobile decoration strip. The water-based acrylic resin is rich in hydroxyl groups, which can react with isocyanate to form a polyurethane segment, so that the surface of the coating can have rigidity and toughness, and is not easy to be scratched, and does not crack for a long time, and has the effect of resisting fingerprints. At the same time, the soft segment of the water-based acrylic resin can also reduce the curing shrinkage and internal stress of the coating, reducing the phenomenon of orange peel and lock hole that is easy to occur in traditional coatings. The light calcium carbonate and barium sulfate are used to improve the brightness of the coating, so that the coating has a mirror effect. The light calcium carbonate enhances the deposition and permeability of the coating on the surface of the substrate, enhances the flowability between the components in the coating system, and improves the hardness, weather resistance and wear resistance of the surface of the coating. The polyacrylic acid sodium is adsorbed between the light calcium carbonate and the barium sulfate, so that the light calcium carbonate and the barium sulfate are uniformly dispersed in the coating system, forming a smooth and bright coating on the surface of the automobile decoration strip.

[0008] Preferably, the hydroxyl value of the water-based acrylic resin is greater than 140 mgKOH / g, and the solid content is 70-80%.

[0009] By adopting the above technical solution, the hydroxyl value of the water-based acrylic resin is controlled within a suitable range, which can better combine with isocyanate, promote the coating to have better hardness, gloss and weather resistance, and also has faster drying speed.

[0010] Preferably, the base material includes the following raw materials in parts by weight: 20-30 parts of hydroxyl acrylic resin, 30-40 parts of amino resin, 3-5 parts of inorganic nano filler, 10-15 parts of curing agent, and 5-10 parts of auxiliary agent.

[0011] By adopting the above technical solution, the cross-linking reaction of hydroxyl acrylic resin and amino resin is used, and through the cross-linking of amino and hydroxyl, a dense compound can be formed on the surface of the stainless steel base material of the automobile trim strip, thereby improving the wear resistance, weather resistance and scratch resistance of the coating.

[0012] Preferably, the particle size of the inorganic nano filler is 50-200 nm.

[0013] Preferably, the inorganic nano filler is polytetrafluoroethylene nano powder and nano silicon dioxide.

[0014] By adopting the above technical solution, the polytetrafluoroethylene nano powder and nano silicon dioxide can improve the wear resistance and corrosion resistance of the coating, promote the coating to have better wear resistance, thereby protecting the automobile trim strip and prolonging the service life of the automobile trim strip. The polytetrafluoroethylene nano powder can reduce the friction coefficient of the coating, reduce the phenomenon of moisture absorption and peeling of the coating, reduce the phenomenon of cracking and peeling of the coating, and further enhance the protection of the coating on the automobile trim strip.

[0015] Preferably, the nano silicon dioxide is modified by a silane coupling agent.

[0016] By adopting the above technical solution, the combination and modification of the silane coupling agent and the nano silicon dioxide can promote the uniform dispersion of the nano silicon dioxide in the coating system, improve the flatness of the coating, and reduce the phenomenon of silicon dioxide particle agglomeration.

[0017] Preferably, the auxiliary agent includes a leveling agent, a defoaming agent and a dispersing agent.

[0018] Preferably, the curing agent is a blocked isocyanate.

[0019] In the second aspect, the application provides an application of a coating for an automobile trim strip, which adopts the following technical solution:

[0020] The application of a coating for an automobile trim strip comprises the following specific steps:

[0021] The water-based acrylic resin, isocyanate, sodium polyacrylate, light calcium carbonate and barium sulfate are mixed in advance to form a protective material mixture, then the base material is coated on the surface of the automobile trim strip, then the protective material mixture is coated on the surface of the base material, and then solidified, thereby completing the application of the coating for the automobile trim strip.

[0022] By adopting the technical scheme, the protective material formed by the synergistic effect of various components is combined with the base material to provide double protection for the automobile trim strip substrate, and the coating has the advantages of gloss, wear resistance and weather resistance.

[0023] In summary, the application has the following beneficial effects:

[0024] 1. Since the water-based acrylic resin and isocyanate are crosslinked in the application, the coating has rigidity and toughness, reducing the phenomena of coating scratches, cracking and peeling, and also having an anti-fingerprint effect. The combination of light calcium carbonate, barium sulfate and sodium polyacrylate enables the light calcium carbonate and barium sulfate to be uniformly and firmly dispersed in the coating system, improving the brightness and mirror effect of the coating.

[0025] 2. In the application, the hydroxy acrylate and amino resin are preferably used to form the base material, which can be firmly combined with the automobile trim strip substrate to improve the wear resistance and weather resistance of the coating. The combination of polytetrafluoroethylene nano powder and nano silicon dioxide improves the corrosion resistance and wear resistance of the coating. DETAILED DESCRIPTION

[0026] The application will be further described in detail below in combination with examples.

[0027] The amino resin is CYMEL 303 amino resin.

[0028] The blocked isocyanate resin is DESMODUR BL3175A curing agent.

[0029] The water-based acrylic resin is YZ-H728 of Yakai Chemical Industry Co., Ltd.

[0030] The isocyanate is HDI trimer of 6852F of Wanhu Chemical Industry Co., Ltd.

[0031] The dispersing agent is ECODISP30 of France Gao Tai Company.

[0032] The defoaming agent is type 1070 defoaming agent.

[0033] The leveling agent is MS-132 type leveling agent.

[0034] The sodium polyacrylate has a molecular weight of 10000.

[0035] The hydroxy acrylic resin has a weight average molecular weight of 1000.

[0036] Embodiment

[0037] Embodiment 1

[0038] The embodiment provides a coating for an automobile trim strip, which comprises a base material and a protective material, the protective material comprising the following raw materials in parts by weight: 25 kg of water-based acrylic resin, 13 kg of isocyanate, 8 kg of light calcium carbonate, 12 kg of barium sulfate and 2 kg of sodium polyacrylate; the base material comprising the following raw materials in parts by weight: 25 kg of hydroxy acrylic resin, 35 kg of amino resin, 4 kg of inorganic nano filler, 13 kg of curing agent and 8 kg of auxiliary agent. The curing agent is a blocked isocyanate, the inorganic nano filler is nano silicon dioxide, the average particle size of the inorganic nano filler is 50-100 nm, and the auxiliary agent is a mixture of leveling agent, defoaming agent and dispersant in a mass ratio of 1:1:1.

[0039] The application of the coating for the automobile trim strip comprises the following specific steps.

[0040] S1: mixing the hydroxy acrylic resin, the amino resin and the curing agent, then adding the inorganic nano filler and the auxiliary agent, stirring uniformly, and forming a base material mixture.

[0041] S2: mixing the water-based acrylic resin, the isocyanate, the sodium polyacrylate, the light calcium carbonate and the barium sulfate, and forming a protective material mixture.

[0042] S3: coating the base material mixture on the surface of the automobile trim strip to form a base material coating with a thickness of 15 μm, heating to a semi-cured state at 80 °C, then coating the protective material mixture on the surface of the base material coating to form a protective material coating with a thickness of 10 μm, and drying at 180 °C, thereby completing the application of the coating for the automobile trim strip.

[0043] Embodiment 2

[0044] The difference between the embodiment 2 and the embodiment 1 is that the use amount of the water-based acrylic resin in the raw materials of the protective material of the coating for the automobile trim strip is 20 kg, the use amount of the isocyanate is 15 kg, the use amount of the light calcium carbonate is 10 kg, the use amount of the barium sulfate is 10 kg, and the use amount of the sodium polyacrylate is 1 kg.

[0045] Embodiment 3

[0046] The difference between Example 3 and Example 1 is that the use amount of the water-based acrylic resin in the protective material raw material in the automobile trim strip coating is 30 kg, the use amount of the isocyanate is 10 kg, the use amount of the light calcium carbonate is 5 kg, the use amount of the barium sulfate is 15 kg, and the use amount of the sodium polyacrylate is 3 kg.

[0047] Example 4

[0048] The difference between Example 4 and Example 1 is that the use amount of the hydroxyl acrylic resin in the base material raw material in the automobile trim strip coating is 20 kg, the use amount of the amino resin is 40 kg, the use amount of the inorganic nano filler is 3 kg, the use amount of the curing agent is 10 kg, and the use amount of the auxiliary agent is 5 kg.

[0049] Example 5

[0050] The difference between Example 5 and Example 1 is that the use amount of the hydroxyl acrylic resin in the base material raw material in the automobile trim strip coating is 30 kg, the use amount of the amino resin is 30 kg, the use amount of the inorganic nano filler is 5 kg, the use amount of the curing agent is 15 kg, and the use amount of the auxiliary agent is 10 kg.

[0051] Example 6

[0052] The difference between Example 6 and Example 1 is that the inorganic nano filler in the base material raw material in the automobile trim strip coating is polytetrafluoroethylene nano powder.

[0053] Example 7

[0054] The difference between Example 7 and Example 1 is that the inorganic nano filler in the base material raw material in the automobile trim strip coating is a mixture of polytetrafluoroethylene nano powder and nano silicon dioxide in a mass ratio of 1:1.

[0055] Example 8

[0056] The difference between Example 8 and Example 7 is that the nano silicon dioxide in the base material raw material in the automobile trim strip coating is modified by a silane coupling agent, and the silane coupling agent is KH550.

[0057] The application of the automobile trim strip coating includes the following specific steps:

[0058] S1: The nano silicon dioxide and the silane coupling agent are mixed in advance, then the polytetrafluoroethylene nano powder is added and stirred uniformly to form an inorganic nano filler; the hydroxyl acrylic resin, the amino resin, and the curing agent are mixed, then the inorganic nano filler and the auxiliary agent are added and stirred uniformly to form a base material mixture.

[0059] S2: The water-based acrylic resin, isocyanate, sodium polyacrylate, light calcium carbonate and barium sulfate are mixed to form a protective material mixture.

[0060] S3: The base material mixture is coated on the surface of the automobile trim strip to form a base material coating with a thickness of 15 μm, heated to a semi-cured state at 80°C, and then the protective material mixture is coated on the surface of the base material coating to form a protective material coating with a thickness of 10 μm, and baked at 180°C, thus completing the application of the coating for automobile trim strip.

[0061] Example 9

[0062] Example 9 differs from Example 1 in that no amino resin is used in the base material raw material of the coating for automobile trim strip.

[0063] Example 10

[0064] Example 10 differs from Example 1 in that no inorganic nano-filler is used in the base material raw material of the coating for automobile trim strip.

[0065] Comparative Example

[0066] Comparative Example 1

[0067] Comparative Example 1 differs from Example 1 in that no base material is used in the coating for automobile trim strip.

[0068] The application of the coating for automobile trim strip includes the following specific steps:

[0069] S1: The water-based acrylic resin, isocyanate, sodium polyacrylate, light calcium carbonate and barium sulfate are mixed to form a protective material mixture.

[0070] S2: The protective material mixture is coated on the surface of the automobile trim strip to form a protective material coating with a thickness of 10 μm, and baked at 180°C, thus completing the application of the coating for automobile trim strip.

[0071] Comparative Example 2

[0072] Comparative Example 2 differs from Example 1 in that no light calcium carbonate is used in the protective material raw material of the coating for automobile trim strip.

[0073] Comparative Example 3

[0074] Comparative Example 3 differs from Example 1 in that no light calcium carbonate and barium sulfate are used in the protective material raw material of the coating for automobile trim strip.

[0075] Comparative Example 4

[0076] Comparative Example 4 differs from Example 1 in that no isocyanate is used in the protective material raw material of the coating for automobile trim strip.

[0077] Performance test

[0078] The automobile trim strips provided according to the examples 1-10 and the comparative examples 1-4 were subjected to the following performance tests, and the specific test results are shown in Table 1.

[0079] Test method

[0080] I. Gloss

[0081] Referring to the standard of GB / T9754-2007 "Determination of 20°, 60° and 85° specular gloss of paint films of non metallic paint and varnish", the automobile trim strip was used as the substrate, and the gloss of the automobile trim strip prepared in the application at 80° was detected.

[0082] II. Impact resistance Referring to the standard of GB / T1732-1993 "Paint film impact resistance test method", the impact resistance of the automobile trim strip prepared in the application was detected.

[0083] III. Wear resistance

[0084] Referring to the standard of GB / T13448-2006 "Test method for color coated steel sheet and steel strip", under the condition of total load of 750g, 500r, the wear resistance of the automobile trim strip prepared in the application was detected.

[0085] IV. Weather resistance

[0086] The automobile trim strip prepared in the application was taken as the sample, 2 hours was taken as one cycle, and within 2 hours, the sample was irradiated by the xenon arc lamp for 1 hour and 42 minutes, and irradiated by the same lamp under the condition of rainfall for 18 minutes. After 500 cycles of repeated tests, the sample was compared with the automobile trim strip which was not subjected to the xenon arc lamp irradiation test.

[0087] Table 1: Performance test result data table

[0088]

[0089] From the performance test results, it can be seen that the automobile trim strip coating prepared in the application has good gloss, wear resistance and weather resistance. Through the combination of various components in the base material and the protective material, the phenomenon of cracking and peeling of the surface coating of the automobile trim strip is reduced. In the examples 1-5 of the application, the use amount of each component is different, and the comprehensive performance of example 1 is better.

[0090] From the comparison of the examples 6, 7 and 1, it can be seen that the combination of polytetrafluoroethylene nano powder and nano silicon dioxide in example 7 can promote the wear resistance of the coating.

[0091] Comparing example 8 with example 1, it can be known that the dispersibility of nano-silica in the coating system is improved by using silane coupling agent to modify nano-silica in example 8, and then the impact resistance and wear resistance of the coating are improved.

[0092] Comparing example 9, 10 with example 1, it can be known that the comprehensive performance of the coating will be reduced by not using amino resin in example 9 and not using inorganic nano-filler in example 10. It is further illustrated that the amino resin and the hydroxyl acrylate resin are crosslinked to form a firm protective coating on the surface of the automobile trim strip, so that the coating has better wear resistance and weather resistance.

[0093] Comparing comparative example 1 with example 1, it can be known that the coating formed in comparative example 1 without using base material has the phenomena of yellowing and cracking. It is further illustrated that the protective effect of pure copper single coating on the automobile trim strip is limited, and the automobile trim strip can be better protected under the synergistic effect of various components in the application.

[0094] Comparing comparative examples 2, 3 with example 1, it can be known that the gloss of the coating is significantly reduced and gradually loses the mirror effect by not using light calcium carbonate in comparative example 2 and not using light calcium carbonate and barium sulfate in comparative example 3. It is further illustrated that the light calcium carbonate and barium sulfate are synergistically combined to make the coating have better gloss and mirror effect, and the calcium carbonate can also enhance the permeability between the coating and the automobile trim strip.

[0095] Comparing comparative example 4 with example 1, it can be known that the coating in comparative example 4 without using isocyanate has the phenomena of cracking and falling off, which may be because the single acrylate resin has large brittleness, so that the coating is prone to cracking and falling off.

[0096] The specific embodiments are only an explanation of the application, and are not a limitation of the application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, and the modifications are protected by the patent law as long as they are within the scope of the claims of the application.

Claims

1. A coating for automobile decorative strips, characterized in that: The invention comprises a base material and a protective material, wherein the protective material comprises the following raw materials in parts by weight: 20-30 parts of water-based acrylic resin, 10-15 parts of isocyanate, 5-10 parts of light calcium carbonate, 10-15 parts of barium sulfate, and 1-3 parts of sodium polyacrylate; the base material comprises the following raw materials in parts by weight: 20-30 parts of hydroxy acrylic resin, 30-40 parts of amino resin, 3-5 parts of inorganic nanofiller, 10-15 parts of curing agent, and 5-10 parts of auxiliary agent; the inorganic nanofiller is polytetrafluoroethylene nanopowder and nanosilica, and the nanosilica is modified with a silane coupling agent; The base material is coated on the surface of the automobile decorative strip, and then the protective material mixture is coated on the surface of the base material.

2. The coating for automobile decorative strips according to claim 1, characterized in that: The water-based acrylic resin has a hydroxyl value greater than 140 mgKOH / g and a solid content of 70-80%.

3. The coating for automobile decorative strips according to claim 1, characterized in that: The particle size of the inorganic nanofiller is 50-200 nm.

4. The coating for automobile decorative strips according to claim 1, characterized in that: The auxiliary agents include leveling agents, defoaming agents and dispersants.

5. The coating for automobile decorative strips according to claim 1, characterized in that: The curing agent is blocked isocyanate.

6. An application of the coating for automobile decorative strips according to any one of claims 1 to 5, characterized in that: The specific steps include: Water-based acrylic resin, isocyanate, sodium polyacrylate, light calcium carbonate and barium sulfate are mixed in advance to form a protective material mixture, and then the base material is coated on the surface of the automobile decorative strip, and then the protective material mixture is coated on the surface of the base material and cured to complete the application of the coating for the automobile decorative strip.

Images