Coating as well as preparation method and application thereof

Abstract

The invention provides a coating as well as a preparation method and application thereof. The coating is prepared from the following raw materials: a side-chain epoxy modified methyl vinyl organosilicon polymer, hydrogen-containing silicone oil, polyurethane elastic powder, a siloxane coupling agent, an inhibitor, matting powder, hydrophobic white carbon black, an organic solvent and a transition metal catalyst. The coating disclosed by the invention can form a low-temperature reaction addition type organic silicon coating, and has excellent adhesive force, wear resistance, corrosion resistance and UV aging resistance. The invention also provides a preparation method and application of the coating.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and in particular relates to a coating and a preparation method and application thereof. Background Art

[0002] With the improvement of social living standards, people have higher and higher requirements for the quality experience of 3C electronics, smart wearables and automotive interior products. Among them, silicone matte feel coatings are gradually favored by consumers because of their delicate and smooth touch, excellent stain resistance and long-term non-stick properties. At present, silicone coatings are mainly divided into UV-curing silicone coatings, condensation silicone coatings and addition silicone coatings according to the reaction mechanism. UV curing type has a high production cost and high paint film hardness, making it only suitable for hard materials and difficult to use for wearable soft rubber materials and high-toughness materials. Condensation silicone reactions are easily affected by environmental humidity, which restricts the large-scale promotion of products. Therefore, in the fields of 3C electronics, smart wearables and automotive interiors, silicone coatings mainly use addition silicone.

[0003] Traditional addition-type silicone coating vulcanization film formation requires curing at a relatively high temperature (above 100°C), which not only consumes a lot of energy, but also easily causes deformation and curling of materials such as TPE and TPU below 0.5mm at high temperatures. In addition, addition-type silicone materials are mainly composed of siloxane molecular chains, which have low surface energy and inertness. This characteristic makes it difficult to attach to other materials, such as automotive interiors, mobile phone back covers, headphone frames, etc. These parts use more TPE, TPU+PC / ABS co-injection materials. Although the double-layer injection molding process has been adopted, due to the very low polarity of vinyl silicone materials, it is almost impossible to directly attach to polar substrates (TPE, TPU and PC / ABS). Usually, a layer of treatment agent is required to achieve adhesion with silicone, but due to its high production cost, complex process, material temperature limit and other factors, it is still difficult to be widely used.

[0004] Therefore, the market is in urgent need of developing a new reactive silicone coating with polar groups, which needs to have a smooth touch, excellent stain resistance and no anti-sticking properties after long-term use, while also being able to achieve a curing reaction of <100°C that can be directly attached to TPE, TPU and PC / ABS co-injected materials with a thickness of less than 0.5mm. Summary of the invention

[0005] The present invention aims to solve at least one of the above technical problems existing in the prior art. To this end, the present invention provides a coating that can form a low-temperature reaction addition type silicone coating with excellent adhesion, wear resistance, corrosion resistance and UV aging resistance.

[0006] The invention also provides a method for preparing the coating.

[0007] The invention also provides application of the coating in 3C products and automobile interior decoration parts.

[0008] The first aspect of the present invention provides a coating, the preparation raw materials of which include side chain epoxy modified methyl vinyl silicone polymer, hydrogenated silicone oil, polyurethane elastic powder, siloxane coupling agent, inhibitor, matting powder, hydrophobic white carbon black, organic solvent and transition metal catalyst.

[0009] One of the technical solutions of the present invention regarding the coating has at least the following beneficial effects:

[0010] The coating of the present invention can form a low-temperature reaction addition type silicone coating, which has excellent adhesion, wear resistance, corrosion resistance and UV aging resistance. The active hydrogen on the hydrogen-containing silicone oil undergoes an addition reaction with the vinyl in the side chain epoxy-modified methyl vinyl silicone polymer under the catalysis of a transition metal catalyst to form an interwoven film layer. In addition, the epoxy group in the side chain epoxy-modified methyl vinyl silicone polymer can react with the active hydrogen in the hydrogen-containing silicone oil (or the active hydrogen in the material) under catalysis to generate a polar group, which can form a strong adhesion with the polar materials TPE, TPU and PC / ABS (the epoxy group itself is also a polar group and can also form a strong adhesion), making it less likely to wrinkle and fall off under the action of external force, and no additional pretreatment layer is required to achieve strong adhesion between the coating and the polar material, which greatly reduces the cost, process and energy consumption. The specific mechanism is as follows Figure 1 and Figure 2 shown.

[0011] In the coating components of the present invention, the side chain epoxy modified methyl vinyl silicone polymer is the main resin, the polyurethane elastic powder, the matting powder and the hydrophobic white carbon black are used as the matting reinforcing agent and the filler, and the siloxane coupling agent is used as the wetting dispersant to improve the dispersibility of the filler and the storage stability of the coating. The components are matched with each other so that the coating has a delicate and smooth hand feeling and excellent appearance, good heat resistance and friction resistance and excellent anti-UV aging performance, as well as good anti-fouling, anti-static, dust-proof and other effects.

[0012] Among them, the molecular weight of the side chain epoxy modified methyl vinyl silicone polymer is preferably 350,000 to 500,000, and the vinyl content is 0.4%. It can ensure complete curing at low temperatures of 70 to 80°C, ensuring that materials with a thickness of less than 0.5 mm will not deform, and at the same time have excellent smooth feel, adhesion and wear resistance. More importantly, the methyl vinyl silicone resin of this specific molecular weight has excellent encapsulation of fillers. When the substrate needs to be toned, the added pigment can reach 20wt%, which can be used to decorate various materials in colorful colors to meet customer customization requirements and solve the defect of single material color.

[0013] Hydrogenated silicone oil can undergo free radical addition reaction with methyl vinyl silicone polymer under the action of transition metal catalyst to form a network cross-linking structure.

[0014] The transition metal catalyst is preferably a Pt complex, and the amount used is preferably 2000-3000 ppm.

[0015] As a transition metal catalyst, Pt complex can significantly promote the hydrogen addition reaction rate and crosslinking degree of methyl vinyl silicone polymer and hydrogen-containing silicone oil, reduce the reaction temperature, and effectively inhibit side reactions during the crosslinking reaction to avoid the formation of black substances, thus overcoming the yellowing or blackening phenomenon of products that are prone to occur during the use of other types of transition metal catalysts.

[0016] Since the transition metal catalyst is highly active, a retarder needs to be added to prevent the crosslinking reaction of the coating composition at room temperature, so that the coating does not produce a crosslinking reaction at room temperature, thereby greatly extending the storage life of the coating; and as the temperature rises, the retarder can be ineffective, and the activity of the transition metal catalyst is unsealed, achieving a highly efficient thermal catalytic effect. The retarder can be a substance that has a low-temperature inhibitory effect on the hydrogen-silicon addition reaction, such as acetylenic alcohol.

[0017] Polyurethane elastic powder is spherical silicon modified polyurethane elastomer powder, which can be one or more of MH-T60 and MH-T70 of Jiangxi Ideal Rubber & Plastic Technology Co., Ltd. as auxiliary wear-resistant powder. The reasonable combination of methyl vinyl silicone resin, spherical silicon modified polyurethane elastomer and hydrogen-containing silicone oil, especially the above-mentioned high molecular weight methyl vinyl silicone resin and polymethyl hydrogen siloxane with a specific hydrogen content, and the addition of spherical silicon modified polyurethane elastomer with smooth hand feeling and excellent wear resistance make the coating have a delicate and smooth hand feeling and excellent appearance, good anti-fouling, anti-static, dust-proof and other effects, and can be re-coated without polishing (similar coatings on the market currently cannot achieve this effect), and have excellent heat resistance and friction resistance, and can provide excellent anti-UV aging performance.

[0018] The silane coupling agent can be Shin-Etsu's KR-516 or KR-517, which is used to improve the wettability, dispersibility and storage stability of pigments and fillers. It is adsorbed on the surface of pigments and fillers to generate charge repulsion or steric hindrance to prevent the pigments and fillers from flocculating and settling, thereby keeping the dispersed system in a stable suspended state, achieving good wetting and dispersing effects and improving the storage stability of the coating.

[0019] The present invention has no particular limitation on the type of organic solvent, which may be a common organic solvent, preferably a mixed organic solvent.

[0020] According to some embodiments of the present invention, the preparation raw materials include, by weight:

[0021] Side chain epoxy modified methyl vinyl silicone polymer: 40-70 parts,

[0022] Hydrogenated silicone oil: 8-18 parts,

[0023] Polyurethane elastic powder: 5-10 parts,

[0024] Siloxane coupling agent: 0.5-2 parts,

[0025] Inhibitor: 0.5-2.5 parts,

[0026] Matting powder: 6-15 parts,

[0027] Hydrophobic white carbon black: 5-8 parts,

[0028] Organic solvent: 60-120 parts,

[0029] Transition metal catalyst: 2 to 3 parts.

[0030] According to some embodiments of the present invention, the preparation raw materials include, by weight:

[0031] Side chain epoxy modified methyl vinyl silicone polymer: 50-60 parts,

[0032] Hydrogenated silicone oil: 10-15 parts,

[0033] Polyurethane elastic powder: 5-8 parts,

[0034] Siloxane coupling agent: 0.8-2 parts,

[0035] Inhibitor: 0.8-2.5 parts,

[0036] Matting powder: 8-10 parts,

[0037] Hydrophobic white carbon black: 5-8 parts,

[0038] Organic solvent: 80-100 parts,

[0039] Transition metal catalyst: 2 to 3 parts.

[0040] According to some embodiments of the present invention, the preparation raw materials include, by weight:

[0041] Side chain epoxy modified methyl vinyl silicone polymer: 60-70 parts,

[0042] Hydrogenated silicone oil: 12-18 parts,

[0043] Polyurethane elastic powder: 6-10 parts,

[0044] Siloxane coupling agent: 1-2 parts,

[0045] Inhibitor: 1-2.5 parts,

[0046] Matting powder: 10-13 parts,

[0047] Hydrophobic white carbon black: 6-8 parts,

[0048] Organic solvent: 100-120 parts,

[0049] Transition metal catalyst: 2.5 to 4 parts.

[0050] According to some embodiments of the present invention, the molecular weight of the side chain epoxy-modified methyl vinyl silicone polymer is 350,000 to 500,000.

[0051] According to some embodiments of the present invention, the vinyl content in the side chain epoxy-modified methyl vinyl silicone polymer is 0.1% to 0.3%.

[0052] According to some embodiments of the present invention, the vinyl content in the side chain epoxy-modified methyl vinyl silicone polymer is 0.4%.

[0053] According to some embodiments of the present invention, the side chain epoxy-modified methyl vinyl silicone polymer may be at least one of CFS8750 of Weifang Fule New Materials and SH-003 of Hubei Sihai New Materials.

[0054] According to some embodiments of the present invention, the hydrogen content of the hydrogen-containing silicone oil is 2.5% to 3.0%.

[0055] According to some embodiments of the present invention, the hydrogen-containing silicone oil may be Momentive TSF484 or Dow Corning MHX-1107.

[0056] According to some embodiments of the invention, the transition metal catalyst comprises a Pt complex.

[0057] The Pt complex may be CAT-PL-56 from Shin-Etsu of Japan.

[0058] According to some embodiments of the invention, the inhibitor comprises methylpentynol.

[0059] According to some embodiments of the present invention, the transition metal catalyst is added to the coating in an amount of 2000 ppm to 3000 ppm.

[0060] According to some embodiments of the invention, the organic solvent comprises at least one of butyl acetate, odorless kerosene, ethyl acetate and n-heptane.

[0061] According to some embodiments of the present invention, the organic solvent is a mixture of butyl acetate, odorless kerosene, ethyl acetate and n-heptane.

[0062] According to some embodiments of the present invention, in the organic solvent, the weight ratio of butyl acetate, odorless kerosene, ethyl acetate and n-heptane is 5-15:5-10:10-30:20-30.

[0063] The organic solvent is a mixed solvent, which is beneficial to the wetting and erosion of the material, can accelerate the embedding of coating molecules and materials, and is also beneficial to the leveling of the paint film and the arrangement of fillers to achieve the best appearance and feel.

[0064] According to some embodiments of the present invention, the particle size of the polyurethane elastic powder is 7 microns to 8 microns.

[0065] According to some embodiments of the present invention, the particle size of the matting powder is ≤5 microns.

[0066] According to some embodiments of the present invention, the particle size of the hydrophobic silica is ≤5 microns.

[0067] The second aspect of the present invention provides a method for preparing the coating of the first aspect of the present invention, comprising the following steps:

[0068] S1: adding the side chain epoxy-modified methyl vinyl silicone polymer, hydrogen-containing silicone oil and inhibitor into part of the organic solvent for a first dispersion;

[0069] S2: adding the polyurethane elastic powder, matting powder and hydrophobic white carbon black to the material of step S1, and adding part of the organic solvent for a second dispersion;

[0070] S3: adding the transition metal catalyst to the material of step S2 for a third dispersion;

[0071] S4: Grind the material from step S3, and add the remaining organic solvent to perform a fourth dispersion.

[0072] A technical solution in the method for preparing the coating of the present invention has at least the following beneficial effects:

[0073] The preparation method of the present invention does not require expensive equipment and complicated process control, has undemanding reaction conditions, has readily available raw materials, has low production costs, and is easy to industrialize.

[0074] According to some embodiments of the present invention, the first dispersion is performed at a speed of 600 rpm to 800 rpm, and the time is 10 min to 15 min.

[0075] According to some embodiments of the present invention, in step S2, when adding the polyurethane elastic powder, matting powder and hydrophobic silica, the organic solvent can be added while dispersing, and the powder is dispersed at a low speed first to ensure that the powder can be fully wetted and evenly coated with the resin, and then the speed is increased for a second dispersion to ensure that there is enough shear force to fully mix the materials.

[0076] According to some embodiments of the present invention, the second dispersion is carried out at a speed of 800 rpm to 1000 rpm and for a time of 10 min to 15 min.

[0077] According to some embodiments of the present invention, the third dispersion is performed at a speed of 800 rpm to 1000 rpm and for a time of 10 min to 15 min.

[0078] According to some embodiments of the present invention, in step S3, during the third dispersion process, when the material temperature is detected to be less than 60°C, the material is dispersed again at 1200rpm-1500rpm for 10mins, and the material viscosity is detected to be 30000-50000mpa / s.

[0079] According to some embodiments of the present invention, in step S4, before the fourth dispersion, the material of step S3 is firstly subjected to three-roll grinding until the coating fineness is less than 10 microns, and then the remaining organic solvent is added to the material for the fourth dispersion.

[0080] According to some embodiments of the present invention, the speed of the fourth dispersion is 2000 rpm to 2500 rpm, and the time is 10 min to 15 min.

[0081] The third aspect of the present invention provides the use of the coating of the first aspect of the present invention in 3C products and automobile interior decoration parts.

[0082] The technical solution of the present invention for the application of coatings in 3C products and automotive interior parts has at least the following beneficial effects:

[0083] The coating of the present invention, when used for 3C products (such as mobile phones, smart wearables, electronic equipment housings, etc.), has the following characteristics:

[0084] (1) Excellent adhesion

[0085] The epoxy groups in the coating react chemically with the surface of the substrate (such as plastic, metal, etc.) to form a strong adhesion, reducing the risk of coating peeling and wrinkling. This is crucial for the high-precision appearance and durability requirements in 3C products.

[0086] (2) Anti-UV aging

[0087] 3C products are often exposed to sunlight and ultraviolet rays. The coating has good anti-UV aging performance, which helps to maintain the stability of the coating color and appearance and extend the service life of the product.

[0088] (3) Wear resistance

[0089] Because polyurethane elastic powder and silane coupling agent are added to the coating, the coating surface is more wear-resistant and can effectively resist surface damage caused by frequent contact and friction, thereby improving the durability of 3C products.

[0090] (4) Anti-fouling, anti-static and anti-dust functions

[0091] 3C products, especially mobile phones and electronic devices, are easily stained with fingerprints, stains, dust, etc. The anti-fouling and anti-dust functions of the coating help keep the shell clean and reduce the frequency of cleaning, and the anti-static performance can prevent dust from adhering.

[0092] (5) Low temperature curing and feel

[0093] The coating can be cured at a low temperature of 70-80°C, which can effectively avoid the risk of thermal deformation of the surface of 3C products. At the same time, the smooth feel of the coating can enhance the user's tactile experience.

[0094] (6) Color customization

[0095] The coating has excellent wrapping properties and can be customized in color by adding pigments to meet the personalized requirements of 3C product appearance design and increase market competitiveness.

[0096] The coating of the present invention, when used for automobile interior decoration parts (such as vehicle dashboards, door panels, etc.), has the following characteristics:

[0097] (1) Wear resistance and corrosion resistance

[0098] Automotive interior parts are often exposed to daily use and environmental changes (such as high temperature, moisture, detergents, etc.). The wear resistance, corrosion resistance and UV aging resistance of the coating can effectively extend the service life of the interior parts and maintain their long-term beauty and functionality.

[0099] (2) Anti-UV aging and heat resistance

[0100] Automotive interior parts are often exposed to direct sunlight, and ultraviolet rays can easily cause the surface to fade and age. The anti-UV components in the paint effectively resist the damage of ultraviolet rays and maintain the color and texture of the interior parts. The heat resistance of the paint makes the interior parts less likely to deform in high temperature environments in summer, maintaining the durability of the appearance.

[0101] (3) Excellent adhesion and durability

[0102] The coating has strong adhesion to various automotive substrates (such as TPE, TPU, PC / ABS, etc.), which can effectively avoid problems such as coating shedding and cracking caused by long-term use, and increase the durability of interior parts.

[0103] (4) Anti-static and dustproof

[0104] Car interior parts are often in contact with the human body. The anti-static function of the paint can effectively reduce dust absorption, keep the car environment clean and tidy, and reduce the safety hazards caused by static electricity.

[0105] (5) Flexibility and anti-fouling function

[0106] The addition of polyurethane elastic powder makes the coating more flexible and wear-resistant, preventing interior parts from being scratched or worn due to friction. In addition, the anti-fouling function of the coating can reduce the accumulation of fingerprints and stains, maintaining the cleanliness of the appearance of interior parts.

[0107] (6) Low temperature curing and adaptability

[0108] The coating can be cured at low temperatures and will not cause thermal damage to the substrate of automotive interior parts. It can save energy, especially in large-scale production processes, and is suitable for automotive interior parts made of different materials.

[0109] In summary, in 3C products, the coating of the present invention can provide a series of excellent properties such as wear resistance, UV aging resistance, anti-fouling, anti-static, and dust resistance, so that the product can maintain excellent appearance and function in long-term use, and improve user experience and product durability. In automotive interior parts, it can not only meet the requirements of high temperature resistance, UV resistance, wear resistance, strong adhesion, anti-fouling and anti-static, but also provide personalized color customization, improving the aesthetics and practicality of interior parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0110] Figure 1 This is one of the mechanism diagrams for the strong adhesion of the coating of the present invention.

[0111] Figure 2 This is the second diagram of the mechanism of the strong adhesion of the coating of the present invention. DETAILED DESCRIPTION

[0112] The following are specific embodiments of the present invention, and the technical solutions of the present invention are further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0113] In the first aspect, some embodiments of the present invention provide a coating, wherein the raw materials for preparing the coating include side chain epoxy-modified methyl vinyl silicone polymer, hydrogen-containing silicone oil, polyurethane elastic powder, siloxane coupling agent, inhibitor, matting powder, hydrophobic silica, organic solvent and transition metal catalyst.

[0114] It should be noted that the coating of the present invention can form a low-temperature reaction addition type silicone coating with excellent adhesion, wear resistance, corrosion resistance and UV aging resistance. The active hydrogen on the hydrogen-containing silicone oil undergoes an addition reaction with the vinyl in the side chain epoxy-modified methyl vinyl silicone polymer under the catalysis of a transition metal catalyst to form an interwoven film layer. In addition, the epoxy group in the side chain epoxy-modified methyl vinyl silicone polymer can react with the active hydrogen in the hydrogen-containing silicone oil (or the active hydrogen in the material) under catalysis to generate a polar group, which can form a strong adhesion with the polar materials TPE, TPU and PC / ABS (the epoxy group itself is also a polar group and can also form a strong adhesion), making it less likely to wrinkle and fall off under the action of external force, and no additional pretreatment layer is required to achieve strong adhesion between the coating and the polar material, which greatly reduces the cost, process and energy consumption. The specific mechanism is as follows Figure 1 and Figure 2 shown.

[0115] It should also be noted that, in the coating components of the present invention, the side chain epoxy-modified methyl vinyl silicone polymer is the main resin, the polyurethane elastic powder, the matting powder and the hydrophobic white carbon black are used as the matting reinforcing agent and the filler, and the siloxane coupling agent is used as the wetting dispersant to improve the dispersibility of the filler and the storage stability of the coating. The components are matched with each other so that the coating has a delicate and smooth feel and excellent appearance, good heat resistance and friction resistance and excellent anti-UV aging performance, as well as good anti-fouling, anti-static, dust-proof and other effects.

[0116] Among them, the molecular weight of the side chain epoxy modified methyl vinyl silicone polymer is preferably 350,000 to 500,000, and the vinyl content is 0.4%. It can ensure complete curing at low temperatures of 70 to 80°C, ensuring that materials with a thickness of less than 0.5 mm will not deform, and at the same time have excellent smooth feel, adhesion and wear resistance. More importantly, the methyl vinyl silicone resin of this specific molecular weight has excellent encapsulation of fillers. When the substrate needs to be toned, the added pigment can reach 20wt%, which can be used to decorate various materials in colorful colors to meet customer customization requirements and solve the defect of single material color.

[0117] Hydrogenated silicone oil can undergo free radical addition reaction with methyl vinyl silicone polymer under the action of transition metal catalyst to form a network cross-linking structure.

[0118] The transition metal catalyst is preferably a Pt complex, and the amount used is preferably 2000-3000 ppm.

[0119] As a transition metal catalyst, Pt complex can significantly promote the hydrogen addition reaction rate and crosslinking degree of methyl vinyl silicone polymer and hydrogen-containing silicone oil, reduce the reaction temperature, and effectively inhibit side reactions during the crosslinking reaction to avoid the formation of black substances, thus overcoming the yellowing or blackening phenomenon of products that are prone to occur during the use of other types of transition metal catalysts.

[0120] Since the transition metal catalyst is highly active, a retarder needs to be added to prevent the crosslinking reaction of the coating composition at room temperature, so that the coating does not produce a crosslinking reaction at room temperature, thereby greatly extending the storage life of the coating; and as the temperature rises, the retarder can be ineffective, and the activity of the transition metal catalyst is unsealed, achieving a highly efficient thermal catalytic effect. The retarder can be a substance that has a low-temperature inhibitory effect on the hydrogen-silicon addition reaction, such as acetylenic alcohol.

[0121] The polyurethane elastic powder is a spherical silicon-modified polyurethane elastomer, which can be used as an auxiliary wear-resistant powder, and can be one or more of MH-T60 and MH-T70 of Jiangxi Ideal Rubber and Plastic Technology Co., Ltd. The reasonable combination of methyl vinyl silicone resin, spherical silicon-modified polyurethane elastomer and hydrogen-containing silicone oil, especially the above-mentioned high molecular weight methyl vinyl silicone resin and polymethyl hydrogen siloxane with a specific hydrogen content, and the addition of spherical silicon-modified polyurethane elastomer with smooth hand feel and excellent wear resistance, makes the coating have a delicate and smooth hand feel and excellent appearance, good anti-fouling, anti-static, dust-proof and other effects, and can be re-coated without polishing (similar coatings on the market currently cannot achieve this effect), and has excellent heat resistance and friction resistance, and can provide excellent anti-UV aging performance.

[0122] The silane coupling agent can be Shin-Etsu's KR-516 or KR-517, which is used to improve the wettability, dispersibility and storage stability of pigments and fillers. It is adsorbed on the surface of pigments and fillers to generate charge repulsion or steric hindrance to prevent the pigments and fillers from flocculating and settling, thereby keeping the dispersed system in a stable suspended state, achieving good wetting and dispersing effects and improving the storage stability of the coating.

[0123] The present invention has no particular limitation on the type of organic solvent, which may be a common organic solvent, preferably a mixed organic solvent.

[0124] In combination with the first aspect, in some embodiments of the present invention, the raw materials for preparation include, by weight:

[0125] Side chain epoxy modified methyl vinyl silicone polymer: 40-70 parts,

[0126] Hydrogenated silicone oil: 8-18 parts,

[0127] Polyurethane elastic powder: 5-10 parts,

[0128] Siloxane coupling agent: 0.5-2 parts,

[0129] Inhibitor: 0.5-2.5 parts,

[0130] Matting powder: 6-15 parts,

[0131] Hydrophobic white carbon black: 5-8 parts,

[0132] Organic solvent: 60-120 parts,

[0133] Transition metal catalyst: 2 to 5 parts.

[0134] In combination with the first aspect, in some embodiments of the present invention, the raw materials for preparation include, by weight: 50 to 60 parts of side chain epoxy-modified methyl vinyl silicone polymer,

[0135] Hydrogenated silicone oil: 10-15 parts,

[0136] Polyurethane elastic powder: 5-8 parts,

[0137] Siloxane coupling agent: 0.8-2 parts,

[0138] Inhibitor: 0.8-2.5 parts,

[0139] Matting powder: 8-10 parts,

[0140] Hydrophobic white carbon black: 5-8 parts,

[0141] Organic solvent: 80-100 parts,

[0142] Transition metal catalyst: 2 to 3 parts.

[0143] In combination with the first aspect, in some embodiments of the present invention, the raw materials for preparation include, by weight: 60 to 70 parts of side chain epoxy-modified methyl vinyl silicone polymer,

[0144] Hydrogenated silicone oil: 12-18 parts,

[0145] Polyurethane elastic powder: 6-10 parts,

[0146] Siloxane coupling agent: 1-2 parts,

[0147] Inhibitor: 1-2.5 parts,

[0148] Matting powder: 10-13 parts,

[0149] Hydrophobic white carbon black: 6-8 parts,

[0150] Organic solvent: 100-120 parts,

[0151] Transition metal catalyst: 2.5 to 4 parts.

[0152] In combination with the first aspect, in some embodiments of the present invention, the molecular weight of the side chain epoxy-modified methyl vinyl silicone polymer is 350,000 to 500,000.

[0153] In combination with the first aspect, in some embodiments of the present invention, the vinyl content in the side chain epoxy-modified methyl vinyl silicone polymer is 0.1% to 0.3%.

[0154] In combination with the first aspect, in some embodiments of the present invention, the vinyl content in the side chain epoxy-modified methyl vinyl silicone polymer is 0.4%.

[0155] In combination with the first aspect, in some embodiments of the present invention, the side chain epoxy-modified methyl vinyl silicone polymer can be at least one of CFS8750 of Weifang Fule New Materials and SH-003 of Hubei Sihai New Materials.

[0156] In combination with the first aspect, in some embodiments of the present invention, the hydrogen content of the hydrogen-containing silicone oil is 2.5% to 3.0%.

[0157] In combination with the first aspect, in some embodiments of the present invention, the hydrogen-containing silicone oil may be Momentive TSF484 or Dow Corning MHX-1107.

[0158] In combination with the first aspect, in some embodiments of the present invention, the transition metal catalyst includes a Pt complex.

[0159] The Pt complex may be CAT-PL-56 from Shin-Etsu of Japan.

[0160] In conjunction with the first aspect, in some embodiments of the present invention, the inhibitor includes methylpentynol.

[0161] In combination with the first aspect, in some embodiments of the present invention, the amount of transition metal catalyst added to the coating is 2000ppm to 3000ppm.

[0162] In combination with the first aspect, in some embodiments of the present invention, the organic solvent includes at least one of butyl acetate, odorless kerosene, ethyl acetate and n-heptane.

[0163] In combination with the first aspect, in some embodiments of the present invention, the organic solvent is a mixture of butyl acetate, odorless kerosene, ethyl acetate and n-heptane.

[0164] In combination with the first aspect, in some embodiments of the present invention, in the organic solvent, the weight ratio of butyl acetate, odorless kerosene, ethyl acetate and n-heptane is 5-15:5-10:10-30:20-30.

[0165] In combination with the first aspect, in some embodiments of the present invention, the particle size of the polyurethane elastic powder is 7 microns to 8 microns.

[0166] In combination with the first aspect, in some embodiments of the present invention, the particle size of the matting powder is ≤5 microns.

[0167] In combination with the first aspect, in some embodiments of the present invention, the particle size of the hydrophobic silica is ≤5 microns.

[0168] In a second aspect, in some embodiments of the present invention, there is provided a method for preparing the coating of the first aspect of the present invention, comprising the following steps:

[0169] S1: adding the side chain epoxy modified methyl vinyl silicone polymer, hydrogen-containing silicone oil and inhibitor into part of the organic solvent for the first dispersion;

[0170] S2: adding polyurethane elastic powder, matting powder and hydrophobic white carbon black to the material of step S1, and adding part of organic solvent for a second dispersion;

[0171] S3: adding a transition metal catalyst to the material of step S2 for a third dispersion;

[0172] S4: Grind the material from step S3, and add the remaining organic solvent to perform a fourth dispersion.

[0173] It can be understood that the preparation method of the present invention does not require expensive equipment and complex process control, the reaction conditions are not harsh, the raw materials are easily available, the production cost is low, and it is easy to industrialize production.

[0174] In combination with the second aspect, in some embodiments of the present invention, the speed of the first dispersion is 600 rpm to 800 rpm, and the time is 10 min to 15 min.

[0175] In combination with the second aspect, in some embodiments of the present invention, in step S2, when adding polyurethane elastic powder, matting powder and hydrophobic silica, organic solvent can be added while dispersing, and the dispersion is carried out at a low speed first to ensure that the powder can be fully wetted and evenly coated with the resin, and then the speed is increased for a second dispersion to ensure that there is enough shear force to fully mix the materials.

[0176] In combination with the second aspect, in some embodiments of the present invention, the speed of the second dispersion is 800 rpm to 1000 rpm, and the time is 10 min to 15 min.

[0177] In combination with the second aspect, in some embodiments of the present invention, the speed of the third dispersion is 800 rpm to 1000 rpm, and the time is 10 min to 15 min.

[0178] In combination with the second aspect, in some embodiments of the present invention, in step S3, during the third dispersion process, when the material temperature is detected to be less than 60°C, it is dispersed again at 1200rpm-1500rpm for 10mins, and the material viscosity is detected to be 30000-50000mpa / s.

[0179] In combination with the second aspect, in some embodiments of the present invention, in step S4, before the fourth dispersion, the material of step S3 is firstly subjected to three-roll grinding until the coating fineness is less than 10 microns, and then the remaining organic solvent is added to the material for the fourth dispersion.

[0180] In combination with the second aspect, in some embodiments of the present invention, the speed of the fourth dispersion is 2000 rpm to 2500 rpm, and the time is 10 min to 15 min.

[0181] In a third aspect, some embodiments of the present invention provide applications of the coating according to the first aspect of the present invention in 3C products and automotive interior trims.

[0182] The technical solution of the present invention for the application of coatings in 3C products and automotive interior parts has at least the following beneficial effects:

[0183] The coating of the present invention, when used for 3C products (such as mobile phones, smart wearables, electronic equipment housings, etc.), has the following characteristics:

[0184] (1) Excellent adhesion

[0185] The epoxy groups in the coating react chemically with the surface of the substrate (such as plastic, metal, etc.) to form a strong adhesion, reducing the risk of coating peeling and wrinkling. This is crucial for the high-precision appearance and durability requirements in 3C products.

[0186] (2) Anti-UV aging

[0187] 3C products are often exposed to sunlight and ultraviolet rays. The coating has good anti-UV aging performance, which helps to maintain the stability of the coating color and appearance and extend the service life of the product.

[0188] (3) Wear resistance

[0189] Because polyurethane elastic powder and silane coupling agent are added to the coating, the coating surface is more wear-resistant and can effectively resist surface damage caused by frequent contact and friction, thereby improving the durability of 3C products.

[0190] (4) Anti-fouling, anti-static and anti-dust functions

[0191] 3C products, especially mobile phones and electronic devices, are easily stained with fingerprints, stains, dust, etc. The anti-fouling and anti-dust functions of the coating help keep the shell clean and reduce the frequency of cleaning, and the anti-static performance can prevent dust from adhering.

[0192] (5) Low temperature curing and feel

[0193] The coating can be cured at a low temperature of 70-80°C, which can effectively avoid the risk of thermal deformation of the surface of 3C products. At the same time, the smooth feel of the coating can enhance the user's tactile experience.

[0194] (6) Color customization

[0195] The coating has excellent wrapping properties and can be customized in color by adding pigments to meet the personalized requirements of 3C product appearance design and increase market competitiveness.

[0196] The coating of the present invention, when used for automobile interior decoration parts (such as vehicle dashboards, door panels, etc.), has the following characteristics:

[0197] (1) Wear resistance and corrosion resistance

[0198] Automotive interior parts are often exposed to daily use and environmental changes (such as high temperature, moisture, detergents, etc.). The wear resistance, corrosion resistance and UV aging resistance of the coating can effectively extend the service life of the interior parts and maintain their long-term beauty and functionality.

[0199] (2) Anti-UV aging and heat resistance

[0200] Automotive interior parts are often exposed to direct sunlight, and ultraviolet rays can easily cause the surface to fade and age. The anti-UV components in the paint effectively resist the damage of ultraviolet rays and maintain the color and texture of the interior parts. The heat resistance of the paint makes the interior parts less likely to deform in high temperature environments in summer, maintaining the durability of the appearance.

[0201] (3) Excellent adhesion and durability

[0202] The coating has strong adhesion to various automotive substrates (such as TPE, TPU, PC / ABS, etc.), which can effectively avoid problems such as coating shedding and cracking caused by long-term use, and increase the durability of interior parts.

[0203] (4) Anti-static and dustproof

[0204] Car interior parts are often in contact with the human body. The anti-static function of the paint can effectively reduce dust absorption, keep the car environment clean and tidy, and reduce the safety hazards caused by static electricity.

[0205] (5) Flexibility and anti-fouling function

[0206] The addition of polyurethane elastic powder makes the coating more flexible and wear-resistant, preventing interior parts from being scratched or worn due to friction. In addition, the anti-fouling function of the coating can reduce the accumulation of fingerprints and stains, maintaining the cleanliness of the appearance of interior parts.

[0207] (6) Low temperature curing and adaptability

[0208] The coating can be cured at low temperatures and will not cause thermal damage to the substrate of automotive interior parts. It can save energy, especially in large-scale production processes, and is suitable for automotive interior parts made of different materials.

[0209] In summary, in 3C products, the coating of the present invention can provide a series of excellent properties such as wear resistance, UV aging resistance, anti-fouling, anti-static, and dust resistance, so that the product can maintain excellent appearance and function in long-term use, and improve user experience and product durability. In automotive interior parts, it can not only meet the requirements of high temperature resistance, UV resistance, wear resistance, strong adhesion, anti-fouling and anti-static, but also provide personalized color customization, improving the aesthetics and practicality of interior parts.

[0210] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0211] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0212] Unless otherwise specified, "room temperature" in the present invention means 25°C±5°C.

[0213] Unless otherwise specified, "about" in the present invention means that the allowable error is within ±2%.

[0214] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0215] Example 1

[0216] A coating was prepared, and the raw materials for preparation were:

[0217] Side chain epoxy modified methyl vinyl silicone polymer: 50 parts,

[0218] Hydrogenated silicone oil: 6 parts,

[0219] Spherical silicon modified polyurethane elastomer powder: 5 parts,

[0220] Siloxane coupling agent: 0.7 parts,

[0221] Methylpentynol inhibitor: 0.5 parts,

[0222] Wax-treated precipitated fumed silica matting powder: 8 parts,

[0223] White carbon black: 6 parts,

[0224] Organic solvent: 63 parts, containing 10 parts of butyl acetate, 8 parts of odorless kerosene, 20 parts of ethyl acetate and 25 parts of n-heptane,

[0225] Transition metal catalyst: 3 parts.

[0226] Among them, the side chain epoxy modified methyl vinyl silicone polymer is CFS8750 from Weifang Fule New Materials.

[0227] The spherical silicon-modified polyurethane elastomer is MH-T60 from Jiangxi Ideal Rubber & Plastic Technology Co., Ltd.

[0228] The hydrogen-containing silicone oil is Momentive TSF484.

[0229] The wax-treated precipitated fumed silica matting powder is a compound of C803 and OK520 from Degussa of Germany, with the mass ratio of C803 to OK520 being 5:3.

[0230] The inhibitor was methylpentynol, purchased from Japan Momentive.

[0231] The silane coupling agent is KMB-403 from Shin-Etsu of Japan.

[0232] The transition metal catalyst was CAT-PL-56 from Shin-Etsu of Japan.

[0233] The coating is a low-temperature reactive anti-fouling type hand-feel coating.

[0234] The preparation method is:

[0235] S1: adding the side chain epoxy modified methyl vinyl silicone polymer, hydrogen-containing silicone oil, methylpentynol inhibitor and siloxane coupling agent into an organic solvent accounting for 60% of the total weight of the organic solvent for the first dispersion;

[0236] S2: adding spherical silicon-modified polyurethane elastomer powder, wax-treated precipitated silica matting powder and white carbon black to the material of step S1, and adding part of the organic solvent for a second dispersion;

[0237] S3: adding a transition metal catalyst to the material of step S2 for a third dispersion;

[0238] S4: Grind the material from step S3, and add the remaining organic solvent to perform a fourth dispersion.

[0239] The speed of the first dispersion was 800 rpm and the time was 15 min.

[0240] The second dispersion speed was 800 rpm and the time was 10 min.

[0241] The third dispersion speed was 1000 rpm and the time was 10 min.

[0242] The speed of the fourth dispersion was 2000 rpm and the time was 15 min.

[0243] In step S2, when adding polyurethane elastic powder, matting powder and hydrophobic silica, organic solvent is added while dispersing. First, disperse at a low speed to ensure that the powder can be fully wetted and evenly coated with the resin, and then speed up for a second dispersion to ensure that there is enough shear force to fully mix the materials.

[0244] In step S3, during the third dispersion process, when the material temperature is detected to be less than 60°C, the material is dispersed again at 2000rpm-2500rpm for 10mins, and the material viscosity is detected to be 30000-50000mpa / s.

[0245] In step S4, before the fourth dispersion, the material of step S3 is firstly subjected to three-roll grinding until the coating fineness is less than 10 microns, and then the remaining organic solvent is added to the material for the fourth dispersion.

[0246] Examples 2 and 3

[0247] The difference from Example 1 is that the addition amount of each raw material is different, as shown in Table 1.

[0248] Comparative Example 1

[0249] The difference from Example 1 in the preparation of raw materials is that conventional methyl vinyl silicone resin is used to prepare a traditional high-temperature coating. The addition amount of each raw material is shown in Table 1.

[0250] The specific preparation method is:

[0251] Methyl vinyl silicone resin: 60 parts,

[0252] Hydrogenated silicone oil: 7 parts,

[0253] Spherical silicon modified polyurethane elastomer powder: 6 parts,

[0254] Wax-treated precipitated fumed silica matting powder: 10 parts,

[0255] White carbon black: 6 parts,

[0256] Transition metal catalyst: 4 parts,

[0257] Silane coupling agent: 1 part,

[0258] Methylpentynol inhibitor: 0.5 parts.

[0259] Organic solvent: 74 parts, containing 12 parts of butyl acetate, 10 parts of odorless kerosene, 22 parts of ethyl acetate and 30 parts of n-heptane.

[0260] The preparation method of the coating of Comparative Example 1 is the same as that of Example 1.

[0261] Table 1

[0262]

[0263] The coatings prepared in Examples 1 to 3 were sprayed on a PC+ABS+LSR substrate with a thickness of less than 0.5 mm, with a wet film thickness of 14±2 μm. The coatings prepared in Examples 1 to 3 were baked in an oven at 70-80°C for 60 min to obtain a sample. The coating prepared in Comparative Example 1 was baked in an oven at 100°C for 60 min to obtain a sample.

[0264] Test Case

[0265] The coating film is subjected to adhesion test, abrasion test, cosmetics resistance test, water boiling test, aging test, hot and cold shock test and salt spray test. The test methods are as follows:

[0266] 1. Adhesion: Tested according to GB9286-1998 standard.

[0267] 2. Wear test: Use Taber linear abrasion tester, load 500g, CS-10 rubber, and rub 40 times / minute.

[0268] 3. Cosmetics resistance test: 16 cosmetics tests at room temperature for 72 hours.

[0269] 4. Boiling test: Soak in 85℃ water for 120 minutes, observe the coating surface condition and test adhesion.

[0270] 5. Xenon lamp aging test: UV wavelength 420nm, light intensity 0.80W / m 2 After being stored for a certain period of time under the conditions, there is no abnormality on the coating surface and the adhesion is ≧5B.

[0271] 6. Hot and cold shock test: Store at -40℃ for 12 hours and then at 80℃ for 12 hours for one cycle, for a total of 10 cycles, observe the coating surface condition and test adhesion.

[0272] 7. Salt spray test: After spraying neutral salt spray continuously for a certain period of time, observe the surface condition of the coating and test the adhesion.

[0273] The test results of the samples of Examples 1-4 and Comparative Example 1 are shown in Table 2.

[0274] Table 2

[0275]

[0276]

[0277] From the above results, it can be seen that the anti-fouling hand-feel coating of the present invention has excellent adhesion, wear resistance, corrosion resistance and UV aging resistance. From the comparison between Example 1 and Comparative Example 1, it can be seen that the use of side chain epoxy modified methyl vinyl silicone polymer as the main resin can achieve the relevant performance of the traditional high temperature silicone coating.

[0278] Furthermore, the coatings of Example 1 and Comparative Example 1 were subjected to comparative tests on chemical resistance, wear resistance, and stain resistance.

[0279] Among them, the chemical resistance test uses 24 commonly used chemicals as test objects.

[0280] The wear resistance test is based on the standards of (rubber wear resistance, Martindale wear resistance).

[0281] The stain resistance test is based on the standard (marker graffiti).

[0282] The results are shown in Table 3.

[0283] Table 3

[0284] Chemical resistance Wear-resistant Stain resistant Example 1 No chemical dyeing (OK) No exposed substrate (OK) No residue (OK) Comparative Example 1 Slight staining No exposed substrate (OK) Slight residue

[0285] The coating of the present invention utilizes the polar groups and covalent bonds generated by the epoxy groups or the epoxy groups after the reaction, and is suitable for polar materials such as TPE and TPU. The specific preparation steps may be: first, the surface of the TPE and TPU substrates is cleaned, and then the silicone touch topcoat is sprayed on the surface of the TPE and TPU substrates by a coating and baking method (no need to make a layer of treatment agent first to achieve adhesion with silicone like traditional coatings), so as to obtain a product with skin touch and strong oil resistance. The specific operation method is: substrate surface cleaning - silicone coating - baking - obtaining the product.

[0286] The product prepared by the invention has excellent oil resistance and touch feel, and can be made into products of different colors through single coating and color addition processes to meet the demand for colorful products.

[0287] The present invention has been described in detail above in conjunction with the embodiments, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in the relevant technical field without departing from the purpose of the present invention.

Claims

1. A coating, characterized in that: The preparation raw materials include side chain epoxy modified methyl vinyl organic silicon polymer, hydrogen-containing silicone oil, polyurethane elastic powder, siloxane coupling agent, inhibitor, matting powder, hydrophobic white carbon black, organic solvent and transition metal catalyst.

2. The coating according to claim 1, characterized in that In parts by weight, the raw materials for preparation include: Side chain epoxy modified methyl vinyl silicone polymer: 40-70 parts, Hydrogenated silicone oil: 6-18 parts, Polyurethane elastic powder: 5-10 parts, Siloxane coupling agent: 0.5-2 parts, Inhibitor: 0.5-2.5 parts, Matting powder: 6-15 parts, Hydrophobic white carbon black: 5-8 parts, Organic solvent: 60-120 parts, Transition metal catalyst: 2 to 5 parts.

3. The coating according to claim 2, characterized in that In parts by weight, the raw materials for preparation include: Side chain epoxy modified methyl vinyl silicone polymer: 50-60 parts, Hydrogenated silicone oil: 10-15 parts, Polyurethane elastic powder: 5-8 parts, Siloxane coupling agent: 0.8-2 parts, Inhibitor: 0.8-2.5 parts, Matting powder: 8-10 parts, Hydrophobic white carbon black: 5-8 parts, Organic solvent: 80-100 parts, Transition metal catalyst: 2.5 to 4 parts.

4. The coating according to any one of claims 1 to 3, characterized in that The molecular weight of the side chain epoxy-modified methyl vinyl silicone polymer is 350,000 to 500,000; and / or the vinyl content of the side chain epoxy-modified methyl vinyl silicone polymer is 0.1% to 0.3%.

5. The coating according to any one of claims 1 to 3, characterized in that The hydrogen content of the hydrogen-containing silicone oil is 2.5% to 3.0%.

6. The coating according to any one of claims 1 to 3, characterized in that The particle size of the polyurethane elastic powder is 7 microns to 8 microns.

7. The coating according to any one of claims 1 to 3, characterized in that The particle size of the matting powder is ≤5 microns; and / or the particle size of the hydrophobic white carbon black is ≤5 microns.

8. A method for preparing a coating as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: S1: adding the side chain epoxy-modified methyl vinyl silicone polymer, hydrogen-containing silicone oil and inhibitor into part of the organic solvent for a first dispersion; S2: adding the polyurethane elastic powder, matting powder and hydrophobic white carbon black to the material of step S1, and adding part of the organic solvent for a second dispersion; S3: adding the transition metal catalyst to the material of step S2 for a third dispersion; S4: Grind the material from step S3, and add the remaining organic solvent to perform a fourth dispersion.

9. The method according to claim 8, characterized in that The speed of the first dispersion is 600rpm~800rpm, and the time is 10min~15min; and / or, the speed of the second dispersion is 1800rpm~2200rpm, and the time is 5min~15min; and / or, the speed of the third dispersion is 800rpm~1000rpm, and the time is 5min~15min; and / or, the speed of the fourth dispersion is 800rpm~1000rpm, and the time is 5min~15min.

10. Use of the coating according to any one of claims 1 to 7 in 3C products and automobile interior decoration parts.

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