Colorless and transparent electroplating primer as well as preparation method and application thereof

Abstract

The invention relates to the technical field of electroplating primer, in particular to colorless and transparent electroplating primer as well as a preparation method and application thereof. The colorless and transparent electroplating primer is prepared from the following raw materials in parts by mass: 30 to 50 parts of UV resin, 8 to 12 parts of first acrylate monomer, 1 to 3 parts of fluorine-containing polyether modified organic silicon, 1 to 3 parts of amino silane coupling agent modified catechin intercalated hydrotalcite, 2 to 5 parts of photoinitiator, 5 to 15 parts of cosolvent and 40 to 60 parts of water, the electroplating primer provided by the invention and the plastic base material, especially the BMC, nylon and glass fiber, PPS and glass fiber plastic base material with extremely low surface energy, have good leveling property, adhesive force and oil stain resistance, and also have good high temperature resistance, heat and humidity resistance and high and low temperature cycle resistance after aluminum plating.

Description

Technical Field

[0001] The invention relates to the technical field of electroplating primers, and more specifically to a colorless and transparent electroplating primer and a preparation method and application thereof. Background Art

[0002] UV vacuum plating is an advanced surface treatment technology that combines the advantages of vacuum plating and ultraviolet light curing coatings to give the material surface a metallic texture or other functional coatings. UV vacuum plating not only makes plastics beautiful and increases the added value of products, but also protects the substrate. In recent years, UV vacuum plating has been widely used in cosmetic packaging bottles, packaging boxes, car lights, mobile phone plastic buttons, watch casings and other fields.

[0003] Because the plastic surface is not flat enough, the surface of the directly electroplated workpiece is not smooth, has low gloss, poor metallic feel, and may even have bubbles. In order to avoid the above problems, the UV vacuum plating coating is generally composed of a primer, a vacuum metallization layer, and a topcoat. The presence of the primer will form a smooth surface and avoid poor electroplating effects due to bubbles in the plastic itself.

[0004] The headlight reflector is an important part of the automotive lamps, which mainly plays the role of concentrating and reflecting light, thereby increasing the brightness and irradiation range of the light. Since the light bulb is easy to generate heat during the power-on process, the electroplating primer is required to have good leveling properties and good high temperature resistance.

[0005] In the prior art, a Chinese patent with publication number CN108912971A discloses a vacuum electroplating primer for automobile lamp cups, a preparation method thereof, and a vacuum electroplating process. The vacuum electroplating primer includes tetrafunctional polyurethane acrylate, bisphenol A epoxy acrylate, hydroxyethyl acrylate, ethyl acetate, polystyrene microspheres, photoinitiator, leveling agent, adhesion promoter, and reactive diluent. The addition of polystyrene microspheres in the technical solution helps to enhance the high temperature resistance of the primer film and the adhesion strength of the primer on the automobile lamp cup; the liquid ceramic further enhances the high temperature resistance of the primer film; the liquid ceramic is combined with N-vinyl pyrrolidone and hydroxyethyl acrylate to help enhance the uniformity of the dispersion of the liquid ceramic in the primer. The Chinese patent with publication number CN103627311A discloses a vacuum electroplating UV curing primer, which includes the following components and weight percentage content: low-functionality polyester acrylate 5-20%, high-functionality polyurethane acrylate 5-25%, modified epoxy acrylate-15%, active diluent 10-20%, solvent 40-0%, photoinitiator 2-5%, leveling agent 0.02-0.5%, defoamer 0.02-0.5%. The primer of this technical solution has the advantages of fast curing, good leveling, high temperature resistance, high gloss, high chemical resistance, high adhesion, etc.

[0006] However, the vacuum plating UV curing primers provided by the above technical solutions all use a large amount of organic solvents as diluents, which do not meet the current industry requirements for environmental protection and health.

[0007] The Chinese patent with the prior art publication number CN108300275A discloses a water-based UV curing vacuum electroplating primer, a preparation method and an electroplating method thereof, which can solve the problems of uneven surface, low gloss, poor metallic feel, poor adhesion and poor wear resistance of electroplated plastics, and can be coated on ABS / PC and ABS plastic substrates. The paint film also has excellent wear resistance, alcohol resistance, sweat resistance and storage stability. However, the technical solution does not disclose its high temperature resistance. In addition, plastic substrates such as BMC (bulk molding compound), nylon plus glass fiber, PPS (polyphenylene sulfide) plus glass fiber used for headlight reflector cups have extremely low surface energy, and water-based vacuum electroplating UV curing primers have the problem of poor wettability thereon. Summary of the invention

[0008] The present invention aims to provide a colorless and transparent electroplating primer and a preparation method thereof. The provided electroplating primer and a plastic substrate, especially a BMC, nylon plus glass fiber, and PPS plus glass fiber plastic substrate with extremely low surface energy, have good leveling, adhesion, and oil resistance, and have good high temperature resistance, moisture and heat resistance, and high and low temperature cycle resistance after aluminum plating.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] The first aspect of the present invention provides a colorless and transparent electroplating primer, wherein the raw materials include, by weight, 30-50 parts of UV resin, 8-12 parts of a first acrylate monomer, 1-3 parts of fluorine-containing polyether-modified silicone, 1-3 parts of aminosilane coupling agent-modified catechin intercalated hydrotalcite, 2-5 parts of a photoinitiator, 5-15 parts of a cosolvent, and 40-60 parts of water;

[0011] The UV resin includes terminal hydroxyl hyperbranched polyester H202 modified polyurethane acrylate emulsion and POSS modified polyurethane acrylate emulsion.

[0012] Preferably, the mass ratio of the hyperbranched polyurethane acrylate emulsion to the POSS modified polyurethane acrylate emulsion is 1-3:1-3.

[0013] Preferably, the method for preparing the hyperbranched polyurethane acrylate emulsion comprises the following steps:

[0014] S1, polyester polyol, diisocyanate and catalyst react to obtain polyurethane prepolymer A, add hydrophilic chain extender to react to obtain polyurethane prepolymer intermediate;

[0015] S2, adding the second acrylate monomer and the terminal hydroxyl hyperbranched polyester H2O2 to react; continuing to add the neutralizing agent to obtain a hyperbranched polyurethane acrylate prepolymer;

[0016] S3, adding the third acrylate monomer, an emulsifier and deionized water and emulsifying under stirring conditions to obtain a hyperbranched polyurethane acrylate emulsion.

[0017] Preferably, the method for preparing the hyperbranched polyurethane acrylate emulsion specifically comprises the following steps:

[0018] S1, polyester polyol, diisocyanate and catalyst are reacted at 75-85°C for 1-4h to obtain polyurethane prepolymer A, a hydrophilic chain extender is added, and the reaction is continued at 60-70°C for 2-3h to obtain a polyurethane prepolymer intermediate;

[0019] S2, adding the second acrylate monomer and the hyperbranched polyester H202, reacting at 50-60°C for 1-3h; continuing to add the neutralizer until the pH value reaches 7-7.2, to obtain a hyperbranched polyurethane acrylate prepolymer;

[0020] S3, cooling to 30-40° C., adding the third acrylate monomer, emulsifier and deionized water, and emulsifying for 1-3 hours at a stirring rate of 800-1200 rpm to obtain a hyperbranched polyurethane acrylate emulsion.

[0021] Preferably, the molar ratio of the polyester polyol, diisocyanate, hydrophilic chain extender, second acrylate monomer, and terminal hydroxyl hyperbranched polyester H202 is (0.2-0.4): (0.8-1.2): (0.4-0.6):

[0022] (0.05-0.15):(0.05-0.15), preferably 0.3:1:0.5:0.1:0.1.

[0023] Preferably, the catalyst is added in an amount of 0.1-0.3% of the total mass of the diisocyanate.

[0024] Preferably, the added amount of the third acrylate monomer is 20-40% of the hyperbranched polyurethane acrylate prepolymer.

[0025] Preferably, the added amount of the emulsifier is 0.2-0.4% of the hyperbranched polyurethane acrylate prepolymer.

[0026] Preferably, the deionized water is added in an amount such that the solid content of the hyperbranched polyurethane acrylate emulsion is 40-50%.

[0027] Preferably, the polyester polyol includes one or more of polybutylene adipate diol, polybutylene adipate-1,4-diol, polycaprolactone polyol, and polyneopentyl adipate diol, preferably a mixture of polybutylene adipate diol and polybutylene adipate-1,4-diol, and the mass ratio of the two is (1-2): (1-2).

[0028] Preferably, the diisocyanate includes one or more of isophorone diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, and diphenylmethane diisocyanate, preferably a mixture of isophorone diisocyanate and hexamethylene diisocyanate, and the mass ratio of the two is (1-3):1.

[0029] Preferably, the catalyst comprises organotin and / or organobismuth, preferably organotin.

[0030] Preferably, the hydrophilic chain extender includes one or more of dimethylolpropionic acid, pyromellitic anhydride, dimethylolbutyric acid, 1,2-propylene glycol-3-sodium sulfonate, 1,4-butanediol-2-sodium sulfonate, and 2-[(2-aminoethyl)amino]ethanesulfonic acid sodium salt, preferably hydroxymethylpropionic acid.

[0031] Preferably, the second acrylate monomer includes one or more of trimethylolpropane triacrylate, pentaerythritol triacrylate, and dipentaerythritol pentaacrylate, preferably a mixture of trimethylolpropane triacrylate and pentaerythritol triacrylate, and the mass ratio of the two is (1-3):1.

[0032] The hyperbranched polyester H202 described in the present invention is an aliphatic hyperbranched polyester with a hydroxyl number of 10-12 mol, a hydroxyl value of 520 mgKOH / g, and a molecular weight of 1200 g / mol, and is purchased from Wuhan Hyperbranched Resin Technology Co., Ltd.

[0033] Preferably, the method for preparing the POSS-modified polyurethane acrylate emulsion comprises the following steps: replacing the terminal hydroxyl hyperbranched polyester H2O2 in S2 with POSS.

[0034] The inventors found in the process of experimental exploration that when a self-made hyperbranched polyurethane acrylate emulsion of terminal hydroxyl hyperbranched polyester H202 is used as a UV resin, the obtained electroplating primer has good adhesion to a plastic substrate, but poor leveling, poor high temperature resistance and poor moisture and heat resistance after aluminum plating, especially, the high temperature resistance after aluminum plating is much worse; and when a self-made hyperbranched polyurethane acrylate emulsion and a POSS modified polyurethane acrylate emulsion are compounded as the UV resin, the obtained electroplating primer has better adhesion and leveling to the plastic substrate, and the high and low temperature cycle resistance, moisture and heat resistance and high temperature resistance after aluminum plating are also improved. The inventors speculate that the hyperbranched polyurethane acrylate emulsion and the POSS modified polyurethane acrylate emulsion are compounded to form a mutually cross-linked network during curing, thereby improving the cross-linking density; and the steric effect brought by the cage-like branched molecular structure in the POSS modified polyurethane acrylate emulsion structure hinders the movement of Si-O bonds, thereby improving the adhesion between the electroplating primer and the plastic substrate and improving the moisture and heat resistance, high and low temperature cycle resistance and high temperature resistance after aluminum plating; in addition, the surface tension of the electroplating primer is reduced after compounding, the surface tension difference of the paint film is balanced, and thus the coating has good leveling property.

[0035] Preferably, the POSS is heptaoctyl trisilanol caged polysilsesquioxane, purchased from Guangzhou Yixin Technology Co., Ltd., model: POSS202.

[0036] Meanwhile, the inventors have also found that only when POSS is heptaoctyltrisilanol cage-like polysilsesquioxane, the obtained electroplating primer has good adhesion to the plastic substrate, and good high temperature resistance and moisture and heat resistance after aluminum plating.

[0037] Preferably, the first acrylic acid ester monomer includes one or more of glycidyl methacrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, butyl methacrylate, hydroxyethyl acrylate and isooctyl acrylate, preferably a mixture of ethyl acrylate, methyl methacrylate and hydroxyethyl acrylate, and the mass ratio of the three is 1:(2-4):(1-3).

[0038] Preferably, the neutralizing agent includes one or more of triethanolamine, diethanolamine, methyldiethanolamine, triethylamine, and ammonia water.

[0039] Preferably, the third acrylate monomer includes one or more of methyl acrylate, butyl acrylate, and methyl methacrylate, preferably methyl acrylate.

[0040] Preferably, the emulsifier includes one or more of sodium dodecyl sulfonate, sodium hexadecyl sulfonate, and sodium dodecylbenzene sulfonate.

[0041] Preferably, the fluorinated polyether-modified silicone is a mixture of fluorinated polyether-modified silicone A and fluorinated polyether-modified silicone B, and the mass ratio of the two is 1:(2-4).

[0042] Preferably, the preparation method of the fluorinated polyether modified organosilicon A comprises the following steps: under nitrogen protection, hydrogen fluorinated silicone oil, dimethylsilyl caged polysilsesquioxane, C 12 -C 14 The fatty alcohol polyoxyethylene polyoxypropylene ether and the Pt catalyst are reacted at 90-120° C. for 4-6 hours to obtain fluorinated polyether modified silicone A.

[0043] Preferably, the hydrogen fluorinated silicone oil, dimethylsilyl caged polysilsesquioxane, C 12 -C 14 The mass ratio of fatty alcohol polyoxyethylene polyoxypropylene ether and Pt catalyst is (10-20):(5-8):(3-6):(0.1-0.3).

[0044] Preferably, the hydrogen-containing fluorosilicone oil is a trifluoropropylmethylsiloxane oligomer terminated with a silicon-hydrogen bond, and the hydrogen-containing fluorosilicone oil is purchased from Fuzhou Taipuda New Materials Co., Ltd., model: TPD-FS8016.

[0045] Preferably, the preparation method of the fluorinated polyether modified silicone B comprises the following steps: under nitrogen protection, terminal hydrogen silicone oil, perfluoromethyl vinyl ether and Pt catalyst react at 90-120° C. for 4-6 hours to obtain fluorinated polyether modified silicone B.

[0046] The inventors found that when a homemade hyperbranched polyurethane acrylate emulsion and a POSS-modified polyurethane acrylate emulsion are compounded as UV resins, the obtained electroplating primer has good adhesion to a BMC substrate and has good high temperature resistance after aluminizing. However, when the plastic substrate is nylon plus glass fiber, the adhesion of the electroplating primer to the nylon plus glass fiber becomes poor, and the high temperature resistance, moisture and heat resistance, and high and low temperature cycle resistance after aluminizing also show varying degrees of decline. To solve the above problems, the inventors tried to introduce fluorinated polyether modified silicone, and unexpectedly found that when homemade fluorinated polyether modified silicone A and fluorinated polyether modified silicone B are used, not only the above problems are solved, but also the obtained electroplating primer has excellent surface oil resistance. The inventors speculate that it is because of the compound use of fluorinated polyether modified silicone A and fluorinated polyether modified silicone B, the two increase the flexibility of the molecular chain of the electroplating primer through synergistic effect, so that the paint film still maintains a certain elasticity under high temperature, high temperature and high humidity, and high and low temperature cycles, reducing the internal stress caused by thermal expansion differences, and further improving the wettability of the paint film to the nylon plus glass fiber substrate, so that they form a tighter adhesion, thereby avoiding the degradation of various properties of the paint film; at the same time, the surface energy of the paint film formed by the joint action of fluorinated polyether modified silicone and POSS modified polyurethane acrylate emulsion is extremely low, avoiding reducing the chance of oil stains adhering to the paint film, and improving the oil stain resistance of the paint film.

[0047] Preferably, the hydrogen content of the hydrogen-terminated silicone oil is 0.1-0.13%, preferably 0.11±0.1%, and is purchased from Ningbo Runhe High-tech Materials Technology Co., Ltd., model RH-6.

[0048] Preferably, the mass ratio of the hydrogen-terminated silicone oil, perfluoromethyl vinyl ether and Pt catalyst is (10-15): (30-50): (0.1-0.3).

[0049] Preferably, the method for preparing the aminosilane coupling agent modified catechin intercalated hydrotalcite comprises the following steps:

[0050] Under nitrogen protection, flower-shaped magnesium aluminum hydrotalcite, catechin sodium salt and water are reacted at 50-80°C for 7-10 hours, filtered, washed and dried to obtain catechin intercalated hydrotalcite; catechin intercalated hydrotalcite is added to an organic solvent, an aminosilane coupling agent is added to react at 50-60°C for 2-5 hours, filtered, washed and dried to obtain aminosilane coupling agent modified catechin intercalated hydrotalcite.

[0051] The electroplating primer obtained by the present invention using self-made UV resin and fluorinated polyether modified organic silicon has good high temperature resistance and moisture heat resistance after aluminum plating, but poor high and low temperature cycle resistance. During the research process, the inventors found that when aminosilane coupling agent modified catechin intercalated hydrotalcite was added, the high and low temperature cycle resistance of the electroplating primer after aluminum plating was improved. The inventors speculate that this is because the aminosilane coupling agent modified catechin intercalated hydrotalcite can not only improve the flexibility and weather resistance of the paint film to cope with changes in the paint film environment, but also the catechin in the aminosilane coupling agent modified catechin intercalated hydrotalcite can be slowly released, and the catechin improves the adhesion of the paint film through hydrogen bonding, π-π stacking, coordination, covalent bonding, etc., further improving the performance of the paint film under high and low temperature cycle conditions.

[0052] Preferably, the catechin sodium salt is obtained by mixing catechin and sodium hydroxide solution in equimolar amounts.

[0053] Preferably, the mass ratio of the layered hydrotalcite, catechin sodium salt and water is (5-10): 1:

[0054] (30-50).

[0055] Preferably, the mass ratio of the catechin intercalated hydrotalcite, the organic solvent and the aminosilane coupling agent is 1:(20-30):(3-5).

[0056] Preferably, the organic solvent includes one or more of benzene, toluene, carbon tetrachloride, cyclohexane and pentane.

[0057] Preferably, the aminosilane coupling agent is a bisaminosilane coupling agent.

[0058] Preferably, the bisaminosilane coupling agent includes KH-792 and / or KH-791.

[0059] In some preferred embodiments, the photoinitiator includes one or more of photoinitiator 1173 (2-hydroxy-2-methyl-1-phenylpropanone), photoinitiator 184 (hydroxycyclohexane phenone), and TPO-L (ethyl 2,4,6-trimethylbenzoylphosphonate), preferably a mixture of photoinitiator 1173 and photoinitiator 184, and the mass ratio of the two is (1-2): (1-2).

[0060] In some preferred embodiments, the co-solvent includes one or more of ethanol, methanol, isopropanol, butanol, propylene glycol methyl ether, ethylene glycol butyl ether, diethylene glycol butyl ether, propylene glycol dibutyl ether, and acetone, preferably isopropanol.

[0061] The second aspect of the present invention provides a method for preparing the colorless and transparent electroplating primer, comprising the following steps: uniformly mixing a UV resin, a first acrylate monomer, a fluorinated polyether-modified silicone, an aminosilane coupling agent-modified catechin intercalated hydrotalcite, a photoinitiator, a cosolvent and water to obtain the primer.

[0062] The third aspect of the present invention provides the use of the colorless and transparent electroplating primer in the reflective cup of a vehicle lamp.

[0063] Preferably, the material of the headlight reflector cup is BMC, nylon plus glass fiber or PPS plus glass fiber.

[0064] Beneficial effects:

[0065] 1. When the present invention adopts homemade hyperbranched polyurethane acrylate emulsion and POSS modified polyurethane acrylate emulsion as UV resin, the obtained electroplating primer has better adhesion and leveling properties to the plastic substrate, and the high and low temperature cycle resistance, moisture and heat resistance and high temperature resistance after aluminum plating are also improved.

[0066] 2. When the POSS of the present invention is heptaoctyltrisilanol cage-like polysilsesquioxane, the obtained electroplating primer has good adhesion to the plastic substrate, and good high temperature resistance and moisture heat resistance after aluminum plating.

[0067] 3. When the self-made fluorinated polyether modified silicone A and fluorinated polyether modified silicone B are used in the present invention, when the plastic substrate is nylon plus glass fiber, the electroplating primer and the nylon plus glass fiber still have good adhesion, and the high temperature resistance, moisture and heat resistance and high and low temperature cycle resistance after aluminum plating are good, and the obtained electroplating primer has excellent surface oil resistance.

[0068] 4. When the aminosilane coupling agent is added to modify the catechin intercalated hydrotalcite, the high and low temperature cycle resistance of the electroplating primer after aluminum plating is improved. DETAILED DESCRIPTION

[0069] In order to better explain the present invention, the following will combine the examples in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. The embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0070] In the following examples, unless otherwise specified, the operating methods used are all conventional operating methods, the equipment used are all conventional equipment, and the raw materials used are all commercially available.

[0071] Example 1

[0072] A colorless and transparent electroplating primer, the raw materials of which include, by weight, 40 parts of UV resin, 10 parts of a first acrylate monomer, 2 parts of fluorinated polyether-modified organic silicon, 2 parts of aminosilane coupling agent-modified catechin intercalated hydrotalcite, 3 parts of a photoinitiator, 20 parts of a cosolvent, and 50 parts of water;

[0073] The UV resin comprises a hyperbranched polyurethane acrylate emulsion and a POSS-modified polyurethane acrylate emulsion; the mass ratio of the hyperbranched polyurethane acrylate emulsion to the POSS-modified polyurethane acrylate emulsion is 1:1;

[0074] The preparation method of the hyperbranched polyurethane acrylate emulsion specifically comprises the following steps:

[0075] S1, polyester polyol, diisocyanate and catalyst are reacted at 80°C for 3 hours to obtain polyurethane prepolymer A, a hydrophilic chain extender is added, and the reaction is continued at 60°C for 3 hours to obtain a polyurethane prepolymer intermediate;

[0076] S2, adding the second acrylate monomer, hyperbranched polyester H202 or heptaoctyl trisilanol caged polysilsesquioxane, reacting at 50°C for 2h; continuing to add a neutralizing agent until the pH value reaches 7, to obtain a hyperbranched polyurethane acrylate prepolymer;

[0077] S3, cooling to 40° C., adding the third acrylate monomer, emulsifier and deionized water, and emulsifying for 3 hours at a stirring rate of 1000 rpm to obtain a hyperbranched polyurethane acrylate emulsion.

[0078] The molar ratio of the polyester polyol, diisocyanate, hydrophilic chain extender, second acrylate monomer, terminal hydroxyl hyperbranched polyester H202 or heptaoctyl trisilanol caged polysilsesquioxane is 0.3:1:0.5:0.1:0.1.

[0079] The hyperbranched polyester H202 is an aliphatic hyperbranched polyester with a hydroxyl number of 10-12 mol, a hydroxyl value of 520 mgKOH / g, and a molecular weight of 1200 g / mol, and is purchased from Wuhan Hyperbranched Resin Technology Co., Ltd.

[0080] The heptaoctyl trisilanol caged polysilsesquioxane was purchased from Guangzhou Yixin Technology Co., Ltd., model: POSS202.

[0081] The added amount of the catalyst is 0.2% of the total mass of the diisocyanate.

[0082] The added amount of the third acrylate monomer is 30% of the hyperbranched polyurethane acrylate prepolymer.

[0083] The added amount of the emulsifier is 0.3% of the hyperbranched polyurethane acrylate prepolymer.

[0084] The amount of deionized water added is such that the solid content of the hyperbranched polyurethane acrylate emulsion is 50%.

[0085] The polyester polyol is polybutylene adipate diol, purchased from Green Union (Jining) Chemical Technology Co., Ltd., model: HY-1022.

[0086] The diisocyanate is a mixture of isophorone diisocyanate (CAS: 4098-71-9) and hexamethylene diisocyanate (CAS: 822-06-0), and the mass ratio of the two is 2:1.

[0087] The catalyst is dibutyltin dilaurate (CAS: 77-58-7).

[0088] The hydrophilic chain extender is hydroxymethyl propionic acid (CAS: 4767-03-7).

[0089] The second acrylate monomer is a mixture of trimethylolpropane triacrylate (CAS: 15625-89-5) and pentaerythritol triacrylate (CAS: 3524-68-3), and the mass ratio of the two is 2:1.

[0090] The neutralizing agent is triethanolamine (CAS: 102-71-6).

[0091] The third acrylate monomer is methyl acrylate (CAS: 96-33-3).

[0092] The emulsifier is sodium dodecyl sulfate (CAS: 2386-53-0).

[0093] The preparation method of the POSS modified polyurethane acrylate emulsion comprises the following steps: replacing the terminal hydroxyl hyperbranched polyester H202 in S2 with heptaoctyl trisilanol caged polysilsesquioxane.

[0094] The first acrylic acid ester monomer is a mixture of ethyl acrylate (CAS: 140-88-5), methyl methacrylate (CAS: 80-62-6) and hydroxyethyl acrylate (CAS: 818-61-1), and the mass ratio of the three is 1:3:2.

[0095] The fluorinated polyether-modified silicone is a mixture of fluorinated polyether-modified silicone A and fluorinated polyether-modified silicone B, and the mass ratio of the two is 1:3.

[0096] The preparation method of the fluorinated polyether modified organic silicon A comprises the following steps: under nitrogen protection, hydrogen fluorinated silicone oil, dimethylsilyl caged polysilsesquioxane, C 12 -C 14Fatty alcohol polyoxyethylene polyoxypropylene ether (CAS: 68439-51-0) and Pt catalyst were reacted at 110° C. for 5 h to obtain fluorinated polyether modified silicone A.

[0097] The hydrogen fluorinated silicone oil, dimethylsilyl caged polysilsesquioxane, C 12 -C 14 The mass ratio of fatty alcohol polyoxyethylene polyoxypropylene ether and Pt catalyst is 15:6:5:0.2.

[0098] The hydrogen-containing fluorosilicone oil is a trifluoropropylmethylsiloxane oligomer terminated with a silicon-hydrogen bond. The hydrogen-containing fluorosilicone oil is purchased from Fuzhou Taipuda New Materials Co., Ltd., model: TPD-FS8016.

[0099] The dimethylsilyl caged polysilsesquioxane was purchased from Shanghai Yuanye Biotechnology Co., Ltd., item number: S24781-1g.

[0100] The preparation method of the fluorinated polyether modified organic silicon B comprises the following steps: under nitrogen protection, terminal hydrogenated silicone oil, perfluoromethyl vinyl ether (CAS: 1187-93-5) and Pt catalyst react at 110° C. for 5 hours to obtain the fluorinated polyether modified organic silicon B.

[0101] The hydrogen-terminated silicone oil has a hydrogen content of 0.11±0.1% and is purchased from Ningbo Runhe High-tech Materials Technology Co., Ltd., with a model number of RH-6.

[0102] The mass ratio of the hydrogen-terminated silicone oil, perfluoromethyl vinyl ether and Pt catalyst is 12:40:0.2.

[0103] The preparation method of the aminosilane coupling agent modified catechin intercalated hydrotalcite comprises the following steps:

[0104] Under nitrogen protection, flower-shaped magnesium aluminum hydrotalcite, catechin sodium salt and water are reacted at 70°C for 9 hours, filtered, washed and dried to obtain catechin intercalated hydrotalcite; catechin intercalated hydrotalcite is added to an organic solvent, an aminosilane coupling agent is added to react at 50°C for 3 hours, filtered, washed and dried to obtain aminosilane coupling agent-modified catechin intercalated hydrotalcite.

[0105] The flower-shaped magnesium aluminum hydrotalcite was purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.

[0106] The catechin sodium salt is obtained by mixing catechin (CAS: 18829-70-4) and sodium hydroxide solution in equal moles.

[0107] The mass ratio of the layered hydrotalcite, catechin sodium salt and water is 8:1:40.

[0108] The mass ratio of the catechin intercalated hydrotalcite, the organic solvent and the aminosilane coupling agent is 1:25:4.

[0109] The organic solvent is cyclohexane.

[0110] The aminosilane coupling agent is a bisaminosilane coupling agent, and the bisaminosilane coupling agent is KH-792.

[0111] The photoinitiator is a mixture of photoinitiator 1173 and photoinitiator 184, and the mass ratio of the two is 1:1.5.

[0112] The co-solvent is isopropanol.

[0113] The preparation method of the colorless and transparent electroplating primer comprises the following steps: uniformly mixing UV resin, a first acrylate monomer, fluorinated polyether modified organic silicon, aminosilane coupling agent modified catechin intercalated hydrotalcite, a photoinitiator, a cosolvent and water to obtain the primer.

[0114] Example 2

[0115] The only difference from implementation 1 is that the colorless and transparent electroplating primer, by weight, includes 30 parts of UV resin, 8 parts of the first acrylate monomer, 1 part of fluorinated polyether modified silicone, 1 part of aminosilane coupling agent modified catechin intercalated hydrotalcite, 2 parts of photoinitiator, 5 parts of cosolvent, and 40 parts of water; the rest are the same.

[0116] Example 3

[0117] The only difference from Example 1 is that the colorless and transparent electroplating primer includes, by weight, 50 parts of UV resin, 12 parts of the first acrylate monomer, 3 parts of fluorinated polyether-modified silicone, 3 parts of aminosilane coupling agent-modified catechin intercalated hydrotalcite, 5 parts of photoinitiator, 15 parts of cosolvent, and 60 parts of water; the rest are the same.

[0118] Comparative Example 1

[0119] The difference from Example 1 is that the terminal hydroxyl hyperbranched polyester H202 is replaced by an equal mass of terminal hydroxyl hyperbranched polyester H402; the hyperbranched polyester H402 is an aromatic hyperbranched polyester with a hydroxyl number of 12 mol, a hydroxyl value of 180 mgKOH / g, and a molecular weight of 3700 g / mol, purchased from Wuhan Hyperbranched Resin Technology Co., Ltd.; the rest are the same.

[0120] Comparative Example 2

[0121] The difference from Example 1 is that the POSS modified polyurethane acrylate emulsion is replaced by a hyperbranched polyurethane acrylate emulsion of equal mass; the rest are the same.

[0122] Comparative Example 3

[0123] The difference from Example 1 is that the heptaoctyltrisilanol caged polysilsesquioxane is replaced with an amino caged polysilsesquioxane of equal mass, purchased from Xi'an Qiyue Biological, item number: Q0000177; the rest are the same.

[0124] Comparative Example 4

[0125] The difference from Example 1 is that the fluorinated polyether-modified silicone A is replaced by fluorinated polyether-modified silicone B of the same mass; the rest are the same.

[0126] Comparative Example 5

[0127] The difference from Example 1 is that the fluorinated polyether-modified silicone B is replaced by the fluorinated polyether-modified silicone A of the same mass; the rest are the same.

[0128] Comparative Example 6

[0129] The difference from Example 1 is that the aminosilane coupling agent-modified catechin intercalated hydrotalcite is replaced by fluorinated polyether-modified silicone of the same mass; the rest are the same.

[0130] Comparative Example 7

[0131] The difference from Example 1 is that the aminosilane coupling agent-modified catechin intercalated hydrotalcite is replaced by an aminosilane coupling agent-modified hydrotalcite of equal mass, and the preparation method of the aminosilane coupling agent-modified hydrotalcite is as follows: flower-shaped magnesium-aluminum hydrotalcite is added to an organic solvent, an aminosilane coupling agent is added, the mixture is reacted at 50° C. for 3 h, and the mixture is filtered, washed, and dried to obtain the aminosilane coupling agent-modified catechin intercalated hydrotalcite; the mass ratio of the flower-shaped magnesium-aluminum hydrotalcite, the organic solvent, and the aminosilane coupling agent is 1:25:4; and the rest are the same.

[0132] Performance Testing:

[0133] 1. Spray the colorless and transparent electroplating primers of Examples 1-3 and Comparative Examples 1-7 directly on the plastic substrate that has not been subjected to the release agent removal process, with the spray gun air pressure of 2 kg / cm 2 The film thickness is 15 μm; after baking at 60°C for 6 minutes, the UV curing energy is 1000 mj / cm 2 The film is cured and then the following tests are performed:

[0134] 1. Leveling: Observe whether there are orange peel, fish eyes, shrinkage holes, pinholes, and edge shrinkage. If none of them appear, it is qualified, otherwise it is unqualified;

[0135] 2. Adhesion: Tested according to the method of GB / T9286-2021 "Scratch test for paint and varnish films".

[0136] 3. Oil resistance: Spray the colorless and transparent electroplating primers of Examples 1-3 and Comparative Examples 1-7 directly on the plastic substrate that has not been subjected to the release agent removal process. After 5 minutes, observe whether there are oil spots or oil stains. If none appear, it is considered qualified. Otherwise, it is considered unqualified.

[0137] 2. High temperature resistance: After the colorless and transparent electroplating primer of Examples 1-3 and Comparative Examples 1-7 is sprayed and cured, a layer of aluminum is electroplated with a thickness of 3 μm and the following test is performed:

[0138] 1. High temperature resistance: After continuous baking at 240℃ for 10h, the adhesion test is carried out according to GB / T9286-2021. If the adhesion is ≤level 1 and the appearance is not discolored, bubbling, fogging, cracking or cracking, it is qualified, otherwise it is unqualified.

[0139] 2. Moisture and heat resistance: After being placed at 65°C, 96% RH for 48 hours, the adhesion test is carried out according to GB / T9286-2021. If the adhesion is ≤ level 1 and the appearance does not have color, blistering, fogging, cracking or cracking, it is qualified, otherwise it is unqualified.

[0140] 3. Resistance to high and low temperature cycles: In an instrument with constantly changing temperature (high temperature is 65°C, 96% RH, low temperature is -20°C), after being placed for 24 hours, the adhesion test is carried out according to GB / T9286-2021. If the adhesion is ≤ level 1 and the appearance does not discolor, bubble, fog, crack or crack, it is qualified, otherwise it is unqualified.

[0141] Test results:

[0142] Table 1 Test results of Examples 1-3 and Comparative Examples 1-2

[0143]

[0144] Table 2 Test results of comparative examples 3-7

[0145]

[0146] It can be seen from Table 1 and Table 2 that the paint films formed by the colorless and transparent electroplating primers of Examples 1-3 on BMC and nylon plus glass fiber have good leveling, adhesion and oil resistance, and have good high and low temperature cycle resistance, high temperature resistance, moisture and heat resistance and high and low temperature cycle resistance after aluminum plating;

[0147] In Comparative Example 1, since the terminal hydroxyl hyperbranched polyester H202 was replaced with the terminal hydroxyl hyperbranched polyester H402 of the same mass, the adhesion of the paint film formed by the electroplating primer on BMC and nylon plus glass fiber decreased, and the moisture and heat resistance, high temperature resistance and high and low temperature cycle resistance after aluminum plating all decreased;

[0148] Comparative Example 2 Since the POSS modified polyurethane acrylate emulsion was replaced with a hyperbranched polyurethane acrylate emulsion of equal quality, the adhesion, leveling and oil resistance of the paint film formed by the electroplating primer on BMC and nylon plus glass fiber were all reduced, and the high temperature resistance, moisture resistance and high and low temperature cycle resistance after aluminum plating were all reduced;

[0149] In Comparative Example 3, since the heptaoctyl trisilanol caged polysilsesquioxane was replaced with an amino caged polysilsesquioxane of equal mass, the adhesion of the paint film formed by the electroplating primer on BMC and nylon plus glass fiber was reduced, and the high temperature resistance and moisture heat resistance after aluminum plating were reduced;

[0150] Comparative Example 4: Since the fluorinated polyether modified silicone A was replaced with the fluorinated polyether modified silicone B of the same quality, the oil resistance of the paint film formed by the electroplating primer on BMC and nylon plus glass fiber decreased, the moisture resistance and high and low temperature cycle resistance decreased after aluminum plating, the adhesion of the paint film formed on nylon plus glass fiber decreased, and the high temperature resistance decreased after aluminum plating;

[0151] Comparative Example 5 Since the fluorinated polyether modified silicone B was replaced by the fluorinated polyether modified silicone A of the same quality, the oil resistance of the paint film formed by the electroplating primer on BMC and nylon plus glass fiber decreased, the moisture resistance and high and low temperature cycle resistance after aluminum plating decreased, the adhesion of the paint film formed on nylon plus glass fiber decreased, and the high temperature resistance decreased after aluminum plating;

[0152] In Comparative Example 6, since the aminosilane coupling agent-modified catechin intercalated hydrotalcite was replaced with fluorinated polyether-modified silicone of equal mass, the high and low temperature cycling resistance of the electroplating primer after aluminum plating on BMC and nylon plus glass fiber decreased;

[0153] In Comparative Example 7, since the aminosilane coupling agent-modified catechin intercalated hydrotalcite was replaced with an aminosilane coupling agent-modified hydrotalcite of equal mass, the high and low temperature cycling resistance of the electroplating primer after aluminum plating on BMC and nylon plus glass fiber decreased.

[0154] The above description is only a specific embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent transformation made by the present invention, or directly or indirectly applied in other related technical fields, is also included in the patent protection scope of the present invention.

Claims

1. A colorless and transparent electroplating primer, characterized in that: The raw materials include 30-50 parts of UV resin, 8-12 parts of the first acrylate monomer, 1-3 parts of fluorinated polyether modified silicone, 1-3 parts of aminosilane coupling agent modified catechin intercalated hydrotalcite, 2-5 parts of photoinitiator, 5-15 parts of cosolvent, and 40-60 parts of water in parts by mass; The UV resin includes hyperbranched polyurethane acrylate emulsion and POSS modified polyurethane acrylate emulsion.

2. The colorless and transparent electroplating primer according to claim 1, characterized in that: The preparation method of the hyperbranched polyurethane acrylate emulsion comprises the following steps: S1, polyester polyol, diisocyanate and catalyst react to obtain polyurethane prepolymer A, add hydrophilic chain extender to react to obtain polyurethane prepolymer intermediate; S2, adding the second acrylate monomer and the terminal hydroxyl hyperbranched polyester H2O2 to react; continuing to add the neutralizing agent to obtain a hyperbranched polyurethane acrylate prepolymer; S3, adding a third acrylate monomer, an emulsifier and deionized water and emulsifying under stirring to obtain a hyperbranched polyurethane acrylate emulsion; The preparation method of the POSS modified polyurethane acrylate emulsion comprises the following steps: replacing the terminal hydroxyl hyperbranched polyester H2O2 in S2 with POSS.

3. The colorless and transparent electroplating primer according to claim 2, characterized in that: The POSS is heptaoctyltrisilanol cage-like polysilsesquioxane.

4. The colorless and transparent electroplating primer according to claim 1, characterized in that: The fluorinated polyether-modified silicone is a mixture of fluorinated polyether-modified silicone A and fluorinated polyether-modified silicone B; The preparation method of the fluorinated polyether modified organic silicon A comprises the following steps: under nitrogen protection, hydrogen fluorinated silicone oil, dimethylsilyl caged polysilsesquioxane, C 12 -C 14 Fatty alcohol polyoxyethylene polyoxypropylene ether and Pt catalyst react at 90-120° C. for 4-6 hours to obtain fluorinated polyether modified silicone A; The preparation method of the fluorinated polyether modified organic silicon B comprises the following steps: under nitrogen protection, terminal hydrogenated silicone oil, perfluoromethyl vinyl ether and Pt catalyst react at 90-120° C. for 4-6 hours to obtain the fluorinated polyether modified organic silicon B.

5. The colorless and transparent electroplating primer according to claim 4, characterized in that: The hydrogen fluorinated silicone oil, dimethylsilyl caged polysilsesquioxane, C 12 -C 14 The mass ratio of fatty alcohol polyoxyethylene polyoxypropylene ether and Pt catalyst is (10-20):(5-8):(3-6):(0.1-0.3).

6. The colorless and transparent electroplating primer according to claim 4, characterized in that: The mass ratio of the hydrogen-terminated silicone oil, perfluoromethyl vinyl ether and Pt catalyst is (10-15): (30-50): (0.1-0.3).

7. The colorless and transparent electroplating primer according to claim 1, characterized in that: The preparation method of the aminosilane coupling agent modified catechin intercalated hydrotalcite comprises the following steps: Under nitrogen protection, flower-shaped magnesium aluminum hydrotalcite, catechin sodium salt and water are reacted at 50-80°C for 7-10 hours, filtered, washed and dried to obtain catechin intercalated hydrotalcite; catechin intercalated hydrotalcite is added to an organic solvent, an aminosilane coupling agent is added to react at 50-60°C for 2-5 hours, filtered, washed and dried to obtain aminosilane coupling agent modified catechin intercalated hydrotalcite.

8. The method for preparing the colorless and transparent electroplating primer according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: uniformly mixing UV resin, a first acrylate monomer, fluorine-containing polyether modified organic silicon, aminosilane coupling agent modified catechin intercalated hydrotalcite, a photoinitiator, a cosolvent and water to obtain the product.

9. Use of the colorless and transparent electroplating primer according to any one of claims 1 to 7 in a reflector cup of a vehicle lamp.

10. The use according to claim 9, characterized in that: The material of the headlight reflector cup is BMC, nylon plus glass fiber or PPS plus glass fiber.

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