Composite material coating capable of being used for attaching TPU (thermoplastic polyurethane) to PC-ABS (polycarbonate-acrylonitrile-butadiene-styrene)

Abstract

The invention relates to the technical field of coating preparation, in particular to a composite coating for attaching TPU (thermoplastic polyurethane) to PC-ABS (polycarbonate-acrylonitrile-butadiene-styrene), which comprises a primer for coating the PC-ABS and a finishing coat for coating the primer layer, the primer is prepared from the following raw materials in parts by weight: polyurethane modified epoxy resin, six-functional aliphatic polyurethane acrylic resin, trimethylolpropane triacrylate, a photoinitiator, a flatting agent, butyl acetate, TPGDA, nano silicon dioxide, a silane coupling agent and a modifier; the finishing paint is prepared from the following raw materials in parts by weight: waterborne polyurethane resin, nano cellulose, water, a defoaming agent, a flatting agent, a dispersing agent, modified sodium alginate, an adhesion promoter, silica sol, nano titanium dioxide, wollastonite and a curing agent. The coating prepared by the invention has good adhesive force on a PC-ABS (polycarbonate-acrylonitrile-butadiene-styrene) base material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of paint preparation, in particular to a composite material paint capable of attaching TPU on PC-ABS. BACKGROUND

[0002] With the rapid development of the automobile industry, the aesthetic, comfort and environmental requirements of interior parts are becoming higher and higher. PC-ABS material is widely used in the manufacture of automobile interior parts due to its good comprehensive performance. However, in practical application, PC-ABS material still has some limitations, such as insufficient texture, limited flexibility, etc.

[0003] In order to improve these problems, the industry generally adopts the technology of attaching TPU on PC-ABS substrate to enhance the flexibility and touch of the product. However, this process faces severe challenges: due to the large difference in thermal expansion coefficient between TPU and PC-ABS, internal stress is easily generated after injection molding, resulting in the decrease of the adhesion of TPU on the surface of PC-ABS substrate.

[0004] Therefore, it is urgent to develop a paint capable of being used on PC-ABS substrate to make the adhesion of TPU on the surface of PC-ABS substrate better. SUMMARY

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a composite material paint capable of attaching TPU on PC-ABS, which is used to solve the problem of poor adhesion of TPU on the surface of PC-ABS substrate in the prior art.

[0006] To achieve the above-mentioned purpose and other related purposes, the present application is obtained by the following technical scheme.

[0007] The present application provides a composite material paint capable of attaching TPU on PC-ABS, which comprises a primer for coating on PC-ABS and a topcoat for coating on the primer; The primer comprises the following raw materials in parts by weight: polyurethane modified epoxy resin 45-55 parts, hexa-aliphatic polyurethane acrylic resin 5-10 parts, trimethylolpropane triacrylate 3-8 parts, photoinitiator 3-5 parts, leveling agent 0.5-1 part, butyl acetate 6-8 parts, TPGDA 8-9 parts, nano-silicon dioxide 3-5 parts, silane coupling agent 3-5 parts, modifier 5-8 parts; the modifier comprises hydroxyl-terminated liquid butyl nitrile rubber, PMMA epoxy-based microspheres and SEBS-g-MAH; The topcoat comprises the following raw materials by weight: 50-60 parts of water-based polyurethane resin, 3-5 parts of nanocellulose, 30-40 parts of water, 1-3 parts of defoaming agent, 1-2 parts of leveling agent, 0.5-1 part of dispersing agent, 1-2 parts of modified sodium alginate, 2-4 parts of adhesion promoter, 3-5 parts of silica sol, 1-2 parts of nanometer titanium dioxide, 3-5 parts of wollastonite, and 2-3 parts of curing agent.

[0008] As described above, the composite coating material for attaching TPU on PC-ABS has the following beneficial effects: The primer component and the topcoat component of the composite coating material are adjusted, and the coating material prepared thereby has better adhesion on PC-ABS, and the primer and the topcoat both contain polyurethane groups, which have better compatibility with the subsequently attached TPU, thereby increasing the adhesion between the PC-ABS substrate and the TPU. DETAILED DESCRIPTION

[0009] In order to make the invention purposes, technical solutions and beneficial technical effects of the present application clearer, the present application will be further described in detail below in conjunction with examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in the present specification.

[0010] The PC-ABS substrate of the present application is an engineering plastic composite material made of polycarbonate (PC) and acrylonitrile-butadiene-styrene copolymer (ABS) through blending or alloying process. It combines the properties of the two materials and is widely used in the fields of automobiles, electronics, home appliances, etc., especially in automobile interior parts. The substrate is a substrate for automobile interior parts known to those skilled in the art, which is not described in detail here.

[0011] The present application provides a composite coating material for attaching TPU on PC-ABS, which comprises a primer for coating on PC-ABS and a topcoat for coating on the primer. The primer comprises the following raw materials by weight: 45-55 parts of polyurethane modified epoxy resin, 5-10 parts of hexa-aliphatic polyurethane acrylic resin, 3-8 parts of trimethylolpropane triacrylate, 3-5 parts of photoinitiator, 0.5-1 part of leveling agent, 6-8 parts of butyl acetate, 8-9 parts of TPGDA, 3-5 parts of nanometer silicon dioxide, 3-5 parts of silane coupling agent, and 5-8 parts of modifier; the modifier comprises hydroxyl-terminated liquid nitrile rubber, PMMA epoxy-based microspheres and SEBS-g-MAH. The topcoat comprises the following raw materials by weight: 50-60 parts of water-based polyurethane resin, 3-5 parts of nanocellulose, 30-40 parts of water, 1-3 parts of defoaming agent, 1-2 parts of leveling agent, 0.5-1 part of dispersing agent, 1-2 parts of modified sodium alginate, 2-4 parts of adhesion promoter, 3-5 parts of silica sol, 1-2 parts of nanometer titanium dioxide, 3-5 parts of wollastonite, and 2-3 parts of curing agent.

[0012] The primer component and the topcoat component of the composite coating are adjusted, and the prepared coating has good adhesion on PC-ABS, and the primer and the topcoat both contain polyurethane groups, which have better compatibility with the subsequently attached TPU, thereby increasing the adhesion between the PC-ABS substrate and the TPU.

[0013] The polyurethane modified epoxy resin added in the primer reacts with the substrate to form a rigid substrate, ensuring anchoring and bonding with the PC-ABS substrate, and the addition of nanometer silicon dioxide and the modifier facilitates the improvement of the wear resistance of the coating, and the addition of the silane coupling agent facilitates the chemical bonding between the primer layer and the topcoat layer and the substrate layer, thereby improving the adhesion between the primer and the topcoat and the substrate layer, and the hydroxyl group (-OH) at the end of the hydroxyl-terminated liquid butyl nitrile rubber (CTBN) in the modifier can form a hydrogen bond or a covalent bond with the polar groups (such as hydroxyl groups and carboxyl groups) on the surface of the substrate (such as PC-ABS), enhancing the interface adsorption. The epoxy groups (-CH(O)CH-) in the PMMA epoxy-based microspheres react with the amino groups, carboxyl groups or active sites on the surface of the coating and the substrate to form a three-dimensional crosslinked network, improving the cohesion of the coating. The PMMA microspheres fill the micropores on the surface of the substrate, forming physical anchoring points; the rubber segments of CTBN penetrate into the surface of the substrate, enhancing mechanical engagement. Nanometer silicon dioxide fills the defects of the coating and forms chemical bonds with the substrate through the silane coupling agent, further improving the adhesion.

[0014] The modified sodium alginate in the topcoat has a certain hydrophobicity, which facilitates the improvement of the water resistance of the topcoat, the rubber segments of the hydroxyl-terminated liquid butyl nitrile rubber (CTBN) in the primer penetrate into the network structure of the modified sodium alginate in the topcoat, forming physical entanglement, and the silane coupling agent (such as KH-550) in the primer exposes free silicon hydroxyl groups (-Si-OH) after curing, which react with the silicon hydroxyl groups in the silica sol in the topcoat to form Si-O-Si covalent bonds, thereby reducing the risk of delamination.

[0015] Trimethylolpropane triacrylate contains three acrylate double bonds, which can crosslink with active groups in the polyurethane resin to form a network structure with high crosslinking density. This significantly improves the hardness and wear resistance of the coating; the crosslinked network structure improves the chemical resistance and weather resistance of the coating, enabling it to maintain stable performance in various harsh environments.

[0016] In some embodiments of the present application, the modifier is composed of hydroxyl-terminated liquid nitrile rubber, PMMA epoxy microspheres and SEBS-g-MAH in a mass ratio of 2-3:5-8:3-5. The mass ratio of the three components of the modifier is adjusted so that the ratio of the three components is optimal, facilitating the better performance of the modifier in the primer.

[0017] The present application is not particularly limited to the waterborne polyurethane resin, and a commercially available product of the waterborne polyurethane resin commonly used by those skilled in the art can be used.

[0018] The present application is not particularly limited to the wollastonite, and a commercially available product of the wollastonite commonly used by those skilled in the art can be used.

[0019] The present application is not particularly limited to the polyurethane-modified epoxy resin, and a commercially available product of the polyurethane-modified epoxy resin commonly used by those skilled in the art can be used.

[0020] The present application is not particularly limited to the hexafunctional aliphatic polyurethane acrylate resin, and a commercially available product of the hexafunctional aliphatic polyurethane acrylate resin commonly used by those skilled in the art can be used.

[0021] The present application is not particularly limited to the trimethylolpropane triacrylate, and a commercially available product of the trimethylolpropane triacrylate commonly used by those skilled in the art can be used.

[0022] The present application is not particularly limited to the silica sol, and a commercially available product of the silica sol commonly used by those skilled in the art can be used.

[0023] In some embodiments of the present application, the PMMA epoxy microspheres are composed of microspheres with a particle size of 0.2-0.5 μm, a particle size of 0.5-1 μm and a particle size of 1-3 μm in a mass ratio of 4-5:4-5:1-2. By increasing the number of microspheres with small and medium particle sizes, the surface tension gradient of the primer is reduced and the mechanical anchoring effect of the coating is increased, and at the same time, the adhesion of the primer is improved in cooperation with nano-silicon dioxide. The PMMA epoxy microspheres can be commercially available or prepared by the method disclosed in the prior art. Specifically, the PMMA epoxy microspheres can be purchased from Wincure, and the preparation method of the PMMA epoxy microspheres is to copolymerize methyl methacrylate (MMA) and glycidyl methacrylate (GMA) by free radical polymerization to form PMMA microspheres containing epoxy groups.

[0024] In some embodiments of the present application, the particle size of the silica sol is composed of 10-40 nm and 50-100 nm in mass ratio of 6-7:3-4. The particle size of the silica sol is graded by different particle sizes of silica sol particles. The silica sol with small particles has a large specific surface area, and the crosslinking density of hydrogen bonds or chemical bonds between particles is high, forming a dense network with a high elastic modulus and good resistance to micro-crack propagation. The silica sol with medium particle size balances the crosslinking density and deformation space, allowing particle slippage, and imparting flexibility to the material.

[0025] In some embodiments of the present application, the preparation method of the modified sodium alginate comprises the following steps: mixing sodium alginate, hexadecyl trimethoxysilane, fumed silica and deionized water, heating to 60-65℃, stirring for 30-60 min, cooling to room temperature, and drying to obtain hydrophobically modified sodium alginate. Sodium alginate has good hydrophilicity. After hydrophobic modification, the hydrophobically modified sodium alginate becomes an amphiphilic molecule. Sodium alginate easily gathers in the paint film of polyurethane topcoat, especially in waterborne polyurethane topcoat. The hydrophobic modification group preferentially gathers in the outermost layer of the paint film, and finally forms a hydrophobic protective film. The hydrophilic group is the main body of the alginate molecular chain, which can be riveted with the molecules in the deep layer of the paint film on one hand, thereby improving the distribution stability of the hydrophobic group, and on the other hand, the hydrophilic group can interweave with each other, making the paint film formed by alginate more compact and not easy to be damaged. In addition, the alginate itself can react with polyurethane to form a stable chemical bond, providing good stress resistance. In addition, alginate is a good film former, which can improve the quality of polyurethane topcoat film. Alginate also has good chemical resistance, weather resistance and mildew resistance, so it can overall improve the performance of polyurethane paint film.

[0026] In some embodiments of the present application, the mass ratio of sodium alginate, hexadecyl trimethoxysilane, fumed silica and deionized water is 1:0.2-0.5:0.8-0.9:10.

[0027] In some embodiments of the present application, the selection of silane coupling agent is not particularly limited, and commercially available products of silane coupling agent commonly used by those skilled in the art can be used. Specifically, the silane coupling agent is composed of γ-glycidoxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane in a mass ratio of 2-3:5-6. The amino group in the silane coupling agent reacts with the hydroxyl group on the surface of PC, and the epoxy group in the silane coupling agent reacts with the polar group in PC, thereby increasing the surface energy of PC and improving the adhesion of the primer on the PC substrate, reducing the occurrence of peeling.

[0028] In some embodiments of the present application, the selection of the photoinitiator is not particularly limited, and a commercially available product of the photoinitiator commonly used by those skilled in the art can be used, and specifically, the photoinitiator is selected from one or more of 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, (2,4,6-trimethylbenzoyl) diphenyl phosphine oxide.

[0029] In some embodiments of the present application, the selection of the leveling agent is not particularly limited, and a commercially available product of the leveling agent commonly used by those skilled in the art can be used, and specifically, the leveling agent is selected from one or more of a polysiloxane-polyether copolymer, a polyester-polysiloxane copolymer, or a fluorine-containing leveling agent.

[0030] In some embodiments of the present application, the selection of the defoaming agent is not particularly limited, and a commercially available product of the defoaming agent commonly used by those skilled in the art can be used, and specifically, the defoaming agent is selected from one or more of an emulsion type silicone defoaming agent or a polyether modified silicone defoaming agent; preferably, the defoaming agent is selected from one or more of GPE10, GPE20, GPE30, and emulsified dimethyl silicone oil.

[0031] In some embodiments of the present application, the selection of the dispersing agent is not particularly limited, and a commercially available product of the dispersing agent commonly used by those skilled in the art can be used, and specifically, the dispersing agent is selected from one or more of sodium dodecyl sulfate, sodium polyacrylate, sodium dodecylbenzenesulfonate, and stearic acid.

[0032] In some embodiments of the present application, the selection of the adhesion promoter is not particularly limited, and a commercially available product of the adhesion promoter commonly used by those skilled in the art can be used, and specifically, the adhesion promoter is selected from one or more of a silane coupling agent, a titanate coupling agent, and nano-silica.

[0033] In some embodiments of the present application, the selection of the curing agent is not particularly limited, and a commercially available product of the curing agent commonly used by those skilled in the art can be used, and specifically, the curing agent is an isocyanate curing agent.

[0034] In some embodiments of the present application, the thickness of the primer layer formed by the primer is 15-20 μm; and the thickness of the topcoat layer formed by the topcoat is 20-25 μm.

[0035] In some embodiments of the present application, the preparation method of the primer comprises the following steps: mixing polyurethane modified epoxy resin, hexa-aliphatic polyurethane acrylic resin and trimethylolpropane triacrylate under light-proof condition to obtain a mixture one, mixing butyl acetate and a photoinitiator to obtain a mixture two; adding the mixture two into the mixture one, and then adding a leveling agent, nano-silica, a silane coupling agent, TPGDA and a modifier, and uniformly stirring to obtain the primer.

[0036] In some embodiments of the present application, the preparation method of the topcoat comprises the following steps: mixing water-based polyurethane resin, nano-cellulose, water, modified sodium alginate, a dispersing agent, an adhesion promoter, silica sol, nano-titanium dioxide, wollastonite and a leveling agent and uniformly stirring, then adding a defoaming agent and continuously stirring uniformly, and then adding a curing agent and uniformly stirring to obtain the topcoat.

[0037] In some embodiments of the present application, the application method of the composite coating comprises the following steps: cleaning the surface of the PC-ABS substrate to remove oil stains and dust, then spraying the primer, curing the primer by UV light after spraying, forming a primer layer after the primer is completely cured, then spraying the topcoat on the primer layer, and baking at 75-80℃ for 15-20min to form a topcoat layer. The UV exposure energy is 1200-1800MJ / cm 2 .

[0038] The present application is further illustrated by the following examples, but the scope of the present application is not limited by the examples.

[0039] When numerical ranges are given, it is understood that every numerical range encompassing the lower value and the upper value of the range is contemplated, unless otherwise indicated. Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art. Unless otherwise indicated, all conditions of the examples were carried out under conventional conditions or manufacturer's recommended conditions. Unless otherwise indicated, all reagents or apparatuses used in the examples were commercially available and were obtained from common suppliers. Any method, apparatus, or material similar or equivalent to those described in the examples can be used in the practice of the present application, unless otherwise stated. Primer example

[0040] Embodiment A1: The embodiment provides a primer, which is prepared from the following raw materials in parts by weight: polyurethane modified epoxy resin 45 parts, hexafunctional aliphatic polyurethane acrylic resin 5 parts, trimethylolpropane triacrylate 3 parts, photoinitiator 3 parts, leveling agent 0.5 parts, butyl acetate 6 parts, TPGDA 8 parts, nano-silicon dioxide 3 parts, silane coupling agent 3 parts, modifier 5 parts. The photoinitiator is 1-hydroxycyclohexyl phenyl ketone; the leveling agent is selected from polysiloxane-polyether copolymer; the nano-silicon dioxide has a particle size of 10-20 nm; the silane coupling agent is composed of γ-glycidyl ether oxypropyl trimethoxysilane and γ-aminopropyl triethoxysilane at a mass ratio of 2:5; the modifier is composed of hydroxyl-terminated liquid butyl nitrile rubber, PMMA epoxy-based microspheres and SEBS-g-MAH at a mass ratio of 2:5:3; the PMMA epoxy-based microspheres have a particle size composed of a particle size of 0.2-0.5 μm, a particle size of 0.5-1 μm and a particle size of 1-3 μm at a mass ratio of 4:4:1.

[0041] The embodiment provides a preparation method of the primer, which comprises the following steps: mixing polyurethane modified epoxy resin, hexafunctional aliphatic polyurethane acrylic resin and trimethylolpropane triacrylate under light-proof conditions to obtain a mixture one, mixing butyl acetate and a photoinitiator to obtain a mixture two; adding the mixture two into the mixture one, and then adding a leveling agent, nano-silicon dioxide, a silane coupling agent, TPGDA and a modifier, and uniformly stirring to obtain the primer. The stirring time is 15 min, and the stirring speed is 800 r / min.

[0042] Embodiment A2: The embodiment provides a primer, which is prepared from the following raw materials in parts by weight: polyurethane modified epoxy resin 50 parts, hexafunctional aliphatic polyurethane acrylic resin 8 parts, trimethylolpropane triacrylate 5 parts, photoinitiator 4 parts, leveling agent 0.8 parts, butyl acetate 7 parts, TPGDA 8 parts, nano-silicon dioxide 4 parts, silane coupling agent 4 parts, modifier 7 parts. The silane coupling agent is composed of γ-glycidyl ether oxypropyl trimethoxysilane and γ-aminopropyl triethoxysilane at a mass ratio of 3:6; the modifier is composed of hydroxyl-terminated liquid butyl nitrile rubber, PMMA epoxy-based microspheres and SEBS-g-MAH at a mass ratio of 3:8:5; the PMMA epoxy-based microspheres have a particle size composed of a particle size of 0.2-0.5 μm, a particle size of 0.5-1 μm and a particle size of 1-3 μm at a mass ratio of 5:5:2.

[0043] The preparation method of the primer of the embodiment is completely same as that of Embodiment A1.

[0044] Example A3: The example provides a primer, which is different from example A1 in that the amount of raw material components is different, which is prepared by the following raw materials in parts by weight: polyurethane modified epoxy resin 55 parts, six aliphatic polyurethane acrylate resin 10 parts, trimethylolpropane triacrylate 8 parts, photoinitiator 5 parts, leveling agent 1 part, butyl acetate 8 parts, TPGDA 9 parts, nano silicon dioxide 5 parts, silane coupling agent 5 parts, modifier 8 parts.

[0045] The preparation method of the primer of the example is exactly the same as example A1.

[0046] Comparative example A1 The comparative example provides a primer, which is different from example A1 in that no modifier is added.

[0047] Comparative example A2 The comparative example provides a primer, which is different from example A1 in that the modifier is PMMA epoxy-based microspheres. Topcoat example

[0048] Example B1: The example provides a topcoat, which includes the following raw materials by weight: water-based polyurethane resin 50 parts, nano cellulose 3 parts, water 30 parts, defoamer 1 part, leveling agent 1 part, dispersing agent 0.5 parts, modified sodium alginate 1 part, adhesion promoter 2 parts, silica sol 3 parts, nano titanium dioxide 1 part, wollastonite 3 parts, curing agent 2 parts. Among them, the defoamer is GPE10 defoamer; the leveling agent is polysiloxane-polyether copolymer; the dispersing agent is sodium dodecyl benzene sulfonate; the preparation method of the modified sodium alginate includes the following steps: mixing sodium alginate, hexadecyl trimethoxysilane, fumed silica and deionized water, heating to 60°C, stirring for 50 min, cooling to room temperature, and drying to obtain modified sodium alginate. Among them, the mass ratio of sodium alginate, hexadecyl trimethoxysilane, fumed silica and deionized water is 1:0.3:0.8:10; the adhesion promoter is composed of γ-aminopropyl triethoxysilane and maleic anhydride grafted polypropylene with a mass ratio of 1:1; the curing agent is an isocyanate curing agent, specifically, HDI biuret; the average particle size of the wollastonite is 5 μm. The particle size of the silica sol is composed of particle size 10-40 nm and particle size 50-100 nm with a mass ratio of 6:3.

[0049] The example provides a preparation method of a topcoat, which includes the following steps: mixing water-based polyurethane resin, nano cellulose, water, modified sodium alginate, dispersing agent, adhesion promoter, silica sol, nano titanium dioxide, wollastonite, leveling agent, stirring uniformly, then adding defoamer, continuing to stir uniformly, then adding curing agent, stirring uniformly, to obtain the topcoat.

[0050] Example B2: The example provides a topcoat, which is different from example B1 in that it comprises the following raw materials by weight: water-based polyurethane resin 55 parts, nanocellulose 4 parts, water 35 parts, defoaming agent 2 parts, leveling agent 1 part, dispersing agent 0.8 parts, modified sodium alginate 1.5 parts, adhesion promoter 3 parts, silica sol 4 parts, nanometer titanium dioxide 1 part, wollastonite 4 parts, curing agent 2 parts. Among them, the particle size of the silica sol is composed of particle size 10-40 nm and particle size 50-100 nm in a mass ratio of 7:4.

[0051] The preparation method of the topcoat of the example is the same as that of example B1.

[0052] Example B3: The example provides a topcoat, which is different from example B1 in that it comprises the following raw materials by weight: water-based polyurethane resin 60 parts, nanocellulose 5 parts, water 40 parts, defoaming agent 3 parts, leveling agent 2 parts, dispersing agent 1 part, modified sodium alginate 2 parts, adhesion promoter 4 parts, silica sol 5 parts, nanometer titanium dioxide 2 parts, wollastonite 5 parts, curing agent 3 parts.

[0053] The preparation method of the topcoat of the example is the same as that of example B1.

[0054] Coating application example Application example 1 The coating process is as follows: The PC-ABS substrate is surface cleaned to remove oil stains and dust; Spray the primer, bake at 65℃ for 10min, UV cure to form a primer layer, the thickness of the primer layer is controlled at 25μm; wherein the primer is the primer prepared in example A1; Spray the topcoat, dry at 78℃ for 35min to form a topcoat layer, obtain a PC-ABS substrate with a paint film layer; wherein the thickness of the topcoat layer is controlled at 15μm. Wherein, the topcoat is the topcoat prepared in example B1.

[0055] Application example 2 The difference between this application example and application example 1 is that the primer of step (2) is example A2; the topcoat of step (3) is example B2.

[0056] Application example 3 The difference between this application example and application example 1 is that the primer of step (2) is example A3; the topcoat of step (3) is example B3.

[0057] Application example 4 The difference between this application example and application example 1 is that the primer of step (2) is comparative example A1.

[0058] Application example 5 The difference between this application example and application example 1 is that the primer of step (2) is comparative example A2.

[0059] Performance test Adhesion test: The adhesion between PC-ABS substrate and paint film layer was tested according to GB / T 9286-1998 "Paint film adhesion test of color paint and varnish", and the test results are shown in Table 1.

[0060] Paint film hardness test: The hardness of PC-ABS substrate paint film layer was tested according to GB / T 6739-2006 "Paint film hardness test of color paint and varnish by pencil method", and the test results are shown in Table 1.

[0061] Water resistance test: The water resistance of the coating was tested according to GB / T 1733-1993 "Paint film water resistance test method", and the test results are shown in Table 1.

[0062] Table 1 Performance test results of PC-ABS substrate paint film layer of application examples 1-5

[0063] In combination with application examples 1-3 and the data in Table 1, it can be seen that the coating prepared by the present application is used to treat PC-ABS substrate, and the adhesion and water resistance are both good.

[0064] The above examples only illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above examples without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. A composite material coating for attaching TPU to PC-ABS, characterized in that, This includes a primer for coating PC-ABS and a topcoat for coating the primer; The primer comprises the following raw materials in parts by weight: 45-55 parts polyurethane modified epoxy resin, 5-10 parts hexafunctional aliphatic polyurethane acrylic resin, 3-8 parts trimethylolpropane triacrylate, 3-5 parts photoinitiator, 0.5-1 part leveling agent, 6-8 parts butyl acetate, 8-9 parts TPGDA, 3-5 parts nano silica, 3-5 parts silane coupling agent, and 5-8 parts modifier; the modifier includes hydroxyl-terminated liquid nitrile rubber, PMMA epoxy microspheres, and SEBS-g-MAH; The topcoat comprises the following raw materials in parts by weight: 50-60 parts waterborne polyurethane resin, 3-5 parts nanocellulose, 30-40 parts water, 1-3 parts defoamer, 1-2 parts leveling agent, 0.5-1 part dispersant, 1-2 parts modified sodium alginate, 2-4 parts adhesion promoter, 3-5 parts silica sol, 1-2 parts nano titanium dioxide, 3-5 parts wollastonite, and 2-3 parts curing agent.

2. The composite material coating according to claim 1, characterized in that: The modifier is composed of hydroxyl-terminated liquid nitrile rubber, PMMA epoxy microspheres, and SEBS-g-MAH in a mass ratio of 2-3:5-8:3-5.

3. The composite material coating according to claim 1, characterized in that: The PMMA epoxy microspheres are composed of particles with diameters of 0.2-0.5 μm, 0.5-1 μm, and 1-3 μm in a mass ratio of 4-5:4-5:1-2.

4. The composite material coating according to claim 1, characterized in that: The silica sol has a particle size of 10-40 nm and a particle size of 50-100 nm in a mass ratio of 6-7:3-4.

5. The composite material coating according to claim 1, characterized in that: The preparation method of the modified sodium alginate includes the following steps: mixing sodium alginate, hexadecyltrimethoxysilane, fumed silica and deionized water, heating to 60-65℃, stirring for 30-60 min, cooling to room temperature, and drying to obtain hydrophobic modified sodium alginate.

6. The composite material coating according to claim 5, characterized in that: The mass ratio of sodium alginate, hexadecyltrimethoxysilane, fumed silica and deionized water is 1:0.2-0.5:0.8-0.9:

10.

7. The composite material coating according to claim 1, characterized in that: The silane coupling agent is composed of γ-glycidoxypropyltrimethoxysilane and γ-aminopropyltriethoxysilane in a mass ratio of 2-3:5-6.

8. The composite material coating according to claim 1, characterized in that: The primer further includes one or more of the following features: the photoinitiator is selected from one or more of 1-hydroxycyclohexylphenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, and (2,4,6-trimethylbenzoyl)diphenylphosphine oxide; and / or the leveling agent is selected from one or more of polysiloxane-polyether copolymer, polyester-polysiloxane copolymer, or fluorinated leveling agent.

9. The composite material coating according to claim 1, characterized in that: The topcoat also includes one or more of the following features: 1) The defoamer is selected from one or more of emulsion-type siloxane defoamers or polyether-modified organosilicon defoamers; preferably, the defoamer is selected from one or more of GPE10, GPE20, GPE30, and emulsified dimethyl silicone oil; 2) The dispersant is selected from one or more of sodium dodecyl sulfate, sodium polyacrylate, sodium dodecylbenzene sulfonate, and stearic acid; 3) The adhesion promoter is selected from one or more of silane coupling agents, titanate coupling agents, and nano silica.

10. The composite material coating according to claim 1, characterized in that: The curing agent is an isocyanate-based curing agent.

Images