Chemical-resistant electroplating finish paint, preparation method thereof and application of chemical-resistant electroplating finish paint in cosmetic packaging

Abstract

The invention relates to the field of finish paint, in particular to chemical-resistant electroplating finish paint as well as a preparation method and application thereof. The chemical-resistant electroplating finish paint is prepared from the following raw materials in parts by mass: 30 to 50 parts of modified acrylate, 15 to 30 parts of epoxy resin, 5 to 10 parts of modified particles, 3 to 6 parts of photoinitiator, 2 to 3 parts of flatting agent, 0.5 to 1 part of defoaming agent, 3 to 10 parts of pigment and 20 to 40 parts of solvent. The finally prepared electroplating finish paint not only has excellent durability and chemical resistance, but also can be further improved in water resistance, aging resistance and mechanical properties, so that the performance requirements of the existing electroplating finish paint are effectively met, and the electroplating finish paint can be effectively applied to the field of cosmetic packaging and has wide application prospects. And meanwhile, the resistance to chemical substances (such as perfume, emulsion and the like) is also effectively improved, and the product has a very excellent application prospect.

Description

Technical Field

[0001] The present application relates to the field of topcoats, and in particular to a chemical-resistant electroplating topcoat and a preparation method and application thereof. Background Art

[0002] Electroplating topcoats, especially those with high chemical resistance, play an important role in modern industry, especially in the field of cosmetic packaging. Such topcoats are usually applied to plastic or metal surfaces that have been vacuum plated to provide an additional layer of protection and decorative effects. They not only enhance the aesthetic appearance of the product, but also give the product surface excellent physical properties, such as wear resistance, scratch resistance, and resistance to chemicals (such as perfumes, lotions, etc.).

[0003] Although existing technologies have greatly improved the quality of electroplating topcoats, there are still many challenges. For example, many electroplating topcoats on the market can only pass sweat simulation tests within a specific pH range, and cannot fully cover all possible changes in actual use environments. This means that in extreme environments, such as high-intensity chemical contact or long-term exposure to special climatic conditions, the durability, water resistance and chemical resistance of the product may be affected; on the other hand, the long-term aging resistance of electroplating topcoats also needs to be improved.

[0004] Therefore, in order to effectively solve the above problems, the present application provides a chemical-resistant electroplating topcoat and a preparation method thereof. The electroplating topcoat finally prepared by the present application not only has excellent durability and chemical resistance, but also can further improve its waterproof, aging resistance and mechanical properties, thereby effectively meeting the performance requirements of existing electroplating topcoats, and can be effectively applied to the field of cosmetic packaging, enhancing the appearance of the product while effectively improving the resistance to chemical substances (such as perfumes, emulsions, etc.), and has very excellent application prospects. Summary of the invention

[0005] In order to solve the above problems, the first aspect of the present application provides a chemical-resistant electroplating topcoat, the raw materials of which are, by mass: 30 to 50 parts of modified acrylate, 15 to 30 parts of epoxy resin, 5 to 10 parts of modified particles, 3 to 6 parts of photoinitiator, 2 to 3 parts of leveling agent, 0.5 to 1 part of defoaming agent, 3 to 10 parts of pigment, and 20 to 40 parts of solvent.

[0006] As a preferred solution, the mass ratio of the modified acrylate, epoxy resin and modified particles is (35-45): (18-24): (6-9).

[0007] As a preferred solution, the mass ratio of the modified acrylate, epoxy resin and modified particles is (38-42): (18-22): (7-8.5).

[0008] As a preferred solution, the preparation method of the modified acrylate comprises the following steps: S1: adding polytetramethylene glycol, bisphenol A type polycarbonate diol and isophorone diisocyanate into a reaction container, heating to 80-95°C for reaction for 3-3.5 hours, filtering and washing the product after the reaction is completed to obtain a prepolymer; S2: adding isooctyl acrylate, isobornyl acrylate, pentaerythritol tetraacrylate and benzoyl peroxide, heating to 110-115°C, stirring at 140-160 rpm for reaction for 4-5 hours, then adding the prepolymer, continuing to keep warm for reaction for 1.5-2 hours until the reaction is complete to obtain a preproduct, finally adding acrylamide and potassium persulfate to the preproduct, cooling to 80-85°C, keeping warm for reaction for 3-4 hours to obtain a reaction product; S3: filtering the reaction product through a 400-600 mesh sieve to remove large particle-like impurities, and the final product is sealed and stored away from light.

[0009] As a preferred solution, the mass ratio of the polytetramethylene ether diol, bisphenol A type polycarbonate diol and isophorone diisocyanate is (1.5-2): (0.6-1): (2.5-3.5).

[0010] As a preferred solution, the mass ratio of isooctyl acrylate, isobornyl acrylate, pentaerythritol tetraacrylate and prepolymer is (15-20): (4.5-6): (1.5-1.8): (10-14).

[0011] As a preferred solution, the mass ratio of the pre-product to acrylamide is (20-25):(3-4).

[0012] In this application, by adding the above-mentioned modified acrylate as the raw material for electroplating topcoat, the chemical resistance and aging resistance of the topcoat can be effectively improved while maintaining the good waterproof, mechanical and other properties of the topcoat. After the topcoat is cured, the added modified acrylate can achieve a dispersion effect on the external stress of the topcoat through the soft segment segment added therein, and then in the actual application process of the topcoat, the cracks and micropore size caused by stress on the surface of the topcoat are greatly reduced, and then in a multi-chemical environment, it can effectively prevent the infiltration of water molecules and chemicals with water as a carrier, greatly reduce its penetration speed, and increase the penetration resistance. Combined with the modified particles added in this application, it can simultaneously achieve surface chemical resistance barrier and internal water clearance, thereby greatly improving the chemical resistance, waterproof and other properties of the topcoat as a whole, and then obtain excellent aging resistance.

[0013] On the other hand, the added modified acrylate can also effectively alleviate the slippage of the internal molecular chain network under the action of external force, enhance the viscosity between the molecular chains, and when cracks occur, it can reduce the internal stress and surface silver streaks caused by external forces through stronger molecular chain entanglement, thereby greatly improving the mechanical properties of the electroplating topcoat.

[0014] As a preferred solution, the epoxy resin is a composition of bisphenol A epoxy resin and bisphenol F epoxy resin.

[0015] As a preferred solution, the epoxy value of the bisphenol A epoxy resin is 0.49 to 0.53 eq / 100g.

[0016] As a preferred solution, the epoxy value of the bisphenol F epoxy resin is 0.8 to 0.95 eq / 100g.

[0017] As a preferred solution, the mass ratio of the bisphenol A epoxy resin to the bisphenol F epoxy resin is (3-5): (0.6-1.2).

[0018] As a preferred scheme, the preparation method of the modified particles includes the following steps: S1: adding a mixture of silicon dioxide and ferric chloride hexahydrate to a DMF solution, adding glutaric anhydride and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, heating to 65-70°C and keeping warm for 2-3 hours; S2: adding a DMF solution containing terephthalic acid and 2-aminoterephthalic acid, adding acetic acid to adjust the pH value to 5.5-6, heating to 120-130°C at 2.5°C / min, and then keeping warm for reaction for 16-18 hours; S3: after the reaction is completed, naturally cool to room temperature, add triethanolamine to adjust the pH to 7-7.5, cool for 2-3 hours, centrifuge the product, wash with DMF and methanol, and dry in a vacuum oven at 70-80°C to obtain the product.

[0019] As a preferred solution, the mass ratio of silicon dioxide, ferric chloride hexahydrate, glutaric anhydride and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane is (1-1.2):(3-3.5):(0.5-0.8):(0.2-0.25).

[0020] As a preferred solution, the mass ratio of the ferric chloride hexahydrate, terephthalic acid and 2-aminoterephthalic acid is (3-3.5): (0.6-0.8): (1-1.5).

[0021] As a preferred solution, the average particle size of the silicon dioxide is 15 to 25 nm; the average particle size of the modified particles is 650 to 750 nm.

[0022] The modified particles added in the present application can not only realize strong hydrogen bonding with modified acrylates through the multi-carboxyl groups on their surface, enhance the stability and bonding effect of the modified particles in the topcoat, reduce segregation, and thus improve the mechanical properties of the topcoat, but can also guide the internal trace moisture through the multi-carboxyl groups on the surface in the topcoat system, and then realize the absorption of internal active molecules and moisture through the internal framework micropores, thereby clearing the internal moisture migration pathway, greatly reducing the flow of moisture in the topcoat and the free phenomenon of active molecules, and thus obtaining excellent waterproof and chemical resistance.

[0023] As a preferred solution, the photoinitiator is at least one of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

[0024] As a preferred solution, the photoinitiator is bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

[0025] As a preferred solution, the leveling agent is at least one of BYK-306, BYK-333, TEGO Flow 425 and Disparlon LVC-210.

[0026] As a preferred solution, the leveling agent is BYK-306.

[0027] As a preferred solution, the defoaming agent is any one of the organosilicon defoaming agents.

[0028] As a preferred solution, the solvent is a combination of butyl acetate and isophorone.

[0029] As a preferred solution, the mass ratio of butyl acetate to isophorone is (3-4.5):(1.5-2).

[0030] As a preferred solution, the mass ratio of butyl acetate to isophorone is (3.2-4):(1.6-1.8).

[0031] As a preferred solution, the pigment is at least one of titanium dioxide, red iron oxide, yellow iron oxide, black iron oxide and brown iron oxide.

[0032] The second aspect of the present application provides a method for preparing the above-mentioned chemical-resistant electroplating topcoat, which specifically includes the following steps: S1: adding modified acrylate, epoxy resin and solvent to a mixing container, stirring at a low speed of 40-60rpm at room temperature until mixed completely, then adding modified particles and increasing the speed to 100-120rpm and stirring evenly at room temperature to obtain a mixture; S2: adding a photoinitiator, a leveling agent, a pigment and a defoaming agent to the mixture, stirring at room temperature at 100-120rpm to obtain a uniform solution product; S3: filtering the obtained uniform solution product through a 400-600 mesh sieve to remove large granular impurities, and sealing the filtrate to avoid light to obtain.

[0033] A third aspect of the present application provides an application of the above-mentioned chemical-resistant electroplating topcoat in cosmetic packaging.

[0034] The beneficial effects of this application are:

[0035] 1. The chemical-resistant electroplating topcoat provided in the present application not only has excellent durability and chemical resistance, but also can further improve its waterproof, aging resistance and mechanical properties, thereby effectively meeting the performance requirements of existing electroplating topcoats, and can be effectively applied to the field of cosmetic packaging, enhancing the appearance of the product while effectively improving the resistance to chemical substances (such as perfumes, emulsions, etc.), and has very excellent application prospects.

[0036] 2. A chemical-resistant electroplating topcoat provided in the present application has a modified acrylate added thereto, and after the topcoat is cured, the added soft segment chain achieves a dispersion effect on the external stress of the topcoat, thereby greatly reducing the cracks and micropore size on the surface of the topcoat caused by stress during the actual application of the topcoat, thereby effectively preventing the infiltration of water molecules and chemicals with water as a carrier in a multi-chemical environment, greatly reducing their penetration rate, and increasing the penetration resistance. Combined with the modified particles added in the present application, it can simultaneously achieve surface chemical resistance barrier and internal water clearance, thereby greatly improving the chemical resistance, waterproof and other properties of the topcoat as a whole, thereby obtaining excellent aging resistance.

[0037] 3. The chemical-resistant electroplating topcoat provided in the present application, the added modified particles can not only realize the strong hydrogen bond connection with the modified acrylate through the multi-carboxyl groups on the surface, enhance the stability and connection of the modified particles in the topcoat, reduce the segregation phenomenon, and thus improve the mechanical properties of the topcoat, but also can realize the guiding effect of the internal trace moisture through the multi-carboxyl groups on the surface in the topcoat system, and then realize the absorption of internal active molecules and moisture through the internal framework micropores, thereby clearing the internal moisture migration pathway, greatly reducing the flow of moisture in the topcoat and the free phenomenon of active molecules, and thus obtaining excellent waterproof and chemical resistance. DETAILED DESCRIPTION

[0038] The following will further explain and demonstrate the technical solutions in the above invention content of this application in the form of specific implementation schemes. The following embodiments are only practical examples used to illustrate and explain the contents of the technical solutions in the specification, and should not limit the scope of the claims to be protected by this application. All technical products based on the technical solutions described in the invention content of this application should be included in the scope to be protected by this application.

[0039] In the following examples, unless otherwise specified, the raw materials are all commercially available products, or can be prepared by methods well known to those skilled in the art.

[0040] Example 1

[0041] Example 1 The first aspect provides a chemical-resistant electroplating topcoat, wherein the raw materials are, by mass: 40.8 parts of modified acrylate, 21.5 parts of epoxy resin, 8 parts of modified particles, 4.5 parts of photoinitiator, 2.2 parts of leveling agent, 0.6 parts of defoaming agent, 4.6 parts of pigment, and 30.5 parts of solvent.

[0042] The preparation method of modified acrylic ester comprises the following steps: S1: adding 1.8 parts of polytetramethylene glycol, 0.8 parts of bisphenol A type polycarbonate diol and 2.9 parts of isophorone diisocyanate into a reaction container, heating to 85°C for reaction for 3.5 hours, filtering and washing the product after the reaction is completed to obtain a prepolymer; S2: adding 18.5 parts of isooctyl acrylate, 5.2 parts of isobornyl acrylate, 1.6 parts of pentaerythritol tetraacrylate and 0.21 parts of benzoyl peroxide; Add acyl, raise the temperature to 110°C, stir at 140rpm for 4h, then add 12.6 parts of prepolymer, continue to keep warm for 2h until the reaction is complete to obtain a pre-product, finally add 3.8 parts of acrylamide and 0.06 parts of potassium persulfate to 22.4 parts of the pre-product, lower the temperature to 80°C, keep warm for 4h to obtain a reaction product; S3: filter the reaction product through a 500-mesh sieve to remove large particulate impurities, and seal the final product and store it away from light.

[0043] The epoxy resin is a composition of bisphenol A epoxy resin and bisphenol F epoxy resin, and the mass ratio of the two is 4.2:1.

[0044] The bisphenol A epoxy resin has an epoxy value of 0.52 eq / 100 g and is purchased from Hanson Corporation of the United States under the model EPON828.

[0045] The bisphenol F epoxy resin has an epoxy value of 0.88 eq / 100 g and is purchased from Hanson Corporation of the United States under the model EPON862.

[0046] The preparation method of the modified particles comprises the following steps: S1: 1.1 parts of silicon dioxide and 3.2 parts of ferric chloride hexahydrate are mixed and added to 100 parts of DMF solution, 0.75 parts of glutaric anhydride and 0.22 parts of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane are added, and the temperature is raised to 70°C and kept warm for 2.5 hours; S2: A DMF solution containing 0.7 parts of terephthalic acid and 1.4 parts of 2-aminoterephthalic acid (40 parts in total) is added, acetic acid is added to adjust the pH value to 5.8, the temperature is raised to 125°C at 2.5°C / min, and then the temperature is kept warm for reaction for 17 hours; S3: After the reaction is completed, it is naturally cooled to room temperature, triethanolamine is added to adjust the pH value to 7.2, and after cooling for 3 hours, the product is centrifuged, washed with DMF and methanol, and vacuum dried at 75°C to obtain the product.

[0047] The average particle size of silica is 21 nm; the average particle size of modified particles is 722 nm.

[0048] The photoinitiator is bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; the leveling agent is BYK-306; and the defoamer is silicone defoamer BYK-028.

[0049] The solvent is a composition of butyl acetate and isophorone, and the mass ratio of the two is 3.5:1.8.

[0050] The pigment is red iron oxide.

[0051] The second aspect of the present embodiment provides a method for preparing the above-mentioned chemical-resistant electroplating topcoat, which specifically includes the following steps: S1: adding modified acrylate, epoxy resin and solvent to a mixing container, stirring at a low speed of 50rpm at room temperature until mixed completely, then adding modified particles, increasing the speed to 120rpm and stirring at room temperature to obtain a mixture; S2: adding a photoinitiator, a leveling agent, a pigment and a defoaming agent to the mixture, stirring at room temperature at 110rpm to obtain a uniform solution product; S3: filtering the obtained uniform solution product through a 500-mesh sieve to remove large granular impurities, and sealing the filtrate to avoid light to obtain.

[0052] Example 2

[0053] The specific implementation of this embodiment is basically the same as that of Example 1, with the only difference being that the chemical-resistant electroplating topcoat has the following raw materials, in parts by mass: 44.6 parts of modified acrylate, 18.5 parts of epoxy resin, 6.2 parts of modified particles, 3.9 parts of photoinitiator, 2.1 parts of leveling agent, 0.6 parts of defoaming agent, 4.4 parts of pigment, and 32.5 parts of solvent.

[0054] The epoxy resin is a composition of bisphenol A epoxy resin and bisphenol F epoxy resin, and the mass ratio of the two is 4.8:0.6.

[0055] The solvent is a composition of butyl acetate and isophorone, and the mass ratio of the two is 4.5:1.5.

[0056] Example 3

[0057] The specific implementation of this embodiment is basically the same as that of Example 1, with the only difference being that the chemical-resistant electroplating topcoat has the following raw materials, in parts by mass: 36.8 parts of modified acrylate, 23.5 parts of epoxy resin, 9 parts of modified particles, 3.9 parts of photoinitiator, 2.1 parts of leveling agent, 0.6 parts of defoaming agent, 4.1 parts of pigment, and 29.5 parts of solvent.

[0058] The epoxy resin is a composition of bisphenol A epoxy resin and bisphenol F epoxy resin, and the mass ratio of the two is 3.2:1.1.

[0059] The solvent is a composition of butyl acetate and isophorone, and the mass ratio of the two is 3.3:2.

[0060] Comparative Example 1

[0061] The specific implementation of this comparative example is basically the same as that of Example 1, except that the chemical-resistant electroplating topcoat, in parts by mass, comprises the following raw materials: 55.2 parts of modified acrylate, 10.5 parts of epoxy resin, 3.5 parts of modified particles, 5.2 parts of photoinitiator, 2.8 parts of leveling agent, 0.6 parts of defoaming agent, 4.6 parts of pigment, and 35.5 parts of solvent.

[0062] The epoxy resin is a composition of bisphenol A epoxy resin and bisphenol F epoxy resin, and the mass ratio of the two is 8:1.

[0063] Comparative Example 2

[0064] The specific implementation of this comparative example is basically the same as that of Example 1, except that the raw materials of the chemical-resistant electroplating topcoat, in parts by mass, are: 30.5 parts of modified acrylate, 30 parts of epoxy resin, 18.8 parts of modified particles, 4.5 parts of photoinitiator, 2.2 parts of leveling agent, 0.6 parts of defoaming agent, 4.6 parts of pigment, and 25.5 parts of solvent.

[0065] The epoxy resin is a composition of bisphenol A epoxy resin and bisphenol F epoxy resin, and the mass ratio of the two is 1:1.

[0066] Comparative Example 3

[0067] The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of modified acrylic ester comprises the following steps: S1: adding 3.2 parts of polytetramethylene glycol, 0.2 parts of bisphenol A polycarbonate diol and 3.5 parts of isophorone diisocyanate into a reaction container, heating to 85°C for reaction for 3.5 hours, filtering and washing the product after the reaction is completed to obtain a prepolymer; S2: adding 18.5 parts of isooctyl acrylate, 5.2 parts of isobornyl acrylate, 1.6 parts of pentaerythritol tetrapropylene glycol, Add acrylate and 0.21 parts of benzoyl peroxide, heat to 110°C, stir at 140rpm for 4h, then add 12.6 parts of prepolymer, keep warm for 2h until the reaction is complete to obtain a preproduct, finally add 3.8 parts of acrylamide and 0.06 parts of potassium persulfate to 22.4 parts of the preproduct, cool to 80°C, keep warm for 4h to obtain a reaction product; S3: filter the reaction product through a 500-mesh sieve to remove large particulate impurities, and seal the final product and store it away from light.

[0068] Comparative Example 4

[0069] The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of the modified acrylate comprises the following steps: S1: adding 1.8 parts of polytetramethylene glycol, 0.8 parts of bisphenol A polycarbonate diol and 2.9 parts of isophorone diisocyanate into a reaction container, heating to 85°C for reaction for 3.5 hours, filtering and washing the product after the reaction is completed to obtain a prepolymer; S2: adding 35.5 parts of isooctyl acrylate, 2.2 parts of isobornyl acrylate, 0.5 parts of pentaerythritol tetraisocyanate, Acrylate and 0.14 parts of benzoyl peroxide are added, and the temperature is raised to 110°C, and the reaction is stirred at 140 rpm for 4 hours, then 7.5 parts of prepolymer are added, and the reaction is kept warm for 2 hours until the reaction is complete to obtain a preproduct, and finally 5.8 parts of acrylamide and 0.08 parts of potassium persulfate are added to 12.5 parts of the preproduct, and the temperature is lowered to 80°C, and the reaction is kept warm for 4 hours to obtain a reaction product; S3: Filter the reaction product through a 500-mesh sieve to remove large particulate impurities, and the final product is sealed and stored away from light.

[0070] Comparative Example 5

[0071] The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of the modified particles comprises the following steps: S1: 0.4 parts of silicon dioxide and 4.5 parts of ferric chloride hexahydrate are mixed and added to 100 parts of DMF solution, 0.35 parts of glutaric anhydride and 0.08 parts of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane are added, and the temperature is raised to 70°C and kept warm for 2.5 hours; S2: A DMF solution containing 0.7 parts of terephthalic acid and 1.4 parts of 2-aminoterephthalic acid (40 parts in total) is added, acetic acid is added to adjust the pH value to 5.8, the temperature is raised to 125°C at 2.5°C / min, and then the temperature is kept for reaction for 17 hours; S3: After the reaction is completed, it is naturally cooled to room temperature, triethanolamine is added to adjust the pH to 7.2, and after cooling for 3 hours, the product is centrifuged, washed with DMF and methanol, and dried in a vacuum oven at 75°C to obtain the product.

[0072] The average particle size of the modified particles was 491 nm.

[0073] Comparative Example 6

[0074] The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of the modified particles comprises the following steps: S1: 1.8 parts of silicon dioxide and 1.9 parts of ferric chloride hexahydrate are mixed and added to 100 parts of DMF solution, 0.75 parts of glutaric anhydride and 0.22 parts of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane are added, and the temperature is raised to 70°C and kept warm for 2.5 hours; S2: A DMF solution containing 0.2 parts of terephthalic acid and 1 part of 2-aminoterephthalic acid (40 parts in total) is added, acetic acid is added to adjust the pH value to 5.8, the temperature is raised to 125°C at 2.5°C / min, and then the reaction is kept warm for 17 hours; S3: After the reaction is completed, it is naturally cooled to room temperature, triethanolamine is added to adjust the pH to 7.2, and after cooling for 3 hours, the product is centrifuged, washed with DMF and methanol, and dried in a vacuum oven at 75°C to obtain the product.

[0075] The average particle size of the modified particles is 806 nm.

[0076] Comparative Example 7

[0077] The specific implementation of this comparative example is basically the same as that of Example 1, except that the average particle size of silicon dioxide is 45 nm; the average particle size of the modified particles is 588 nm.

[0078] Performance Evaluation

[0079] Flexibility test: After curing, the electroplating topcoats prepared in the examples and comparative examples were subjected to flexibility test, with reference to standard GBT1731-1993. The test values ​​were averaged from 10 tests and recorded in Table 1.

[0080] Folding resistance test: After curing, the electroplating topcoats prepared in the embodiments and comparative examples were subjected to a folding resistance test, which was performed by bending at 180°. The bending conditions of the electroplating topcoats were recorded in Table 1.

[0081] Boiling test: After curing, the electroplating topcoat prepared in the embodiment and the comparative example was subjected to boiling test, boiling temperature: 100°C, boiling time: 4h, appearance inspection: no shedding, damage and cracks were recorded as qualified, otherwise it was unqualified, 50 groups of samples were tested in each group, and the qualified rate was recorded in Table 1.

[0082] Chemical salt spray resistance test: After curing, the electroplating topcoat prepared in the embodiment and the comparative example was subjected to a chemical salt spray resistance test. The test environment temperature was 38±2°C, the humidity was 92±2%, the test solution was 7.5wt% NaCl solution, the test time was 600h, and the spraying rate was 2ml / h·80cm 2 After the test is completed, observe whether the electroplating paint has corrosion, shedding, cracks and blistering. If so, it is recorded as unqualified, otherwise it is qualified. Each group tests 50 groups of samples, and the qualified rate is recorded in Table 1.

[0083] Table 1 Performance test results

[0084]

[0085]

[0086] It can be seen from the examples and comparative examples of the present application and the data results in Table 1 that examples 1 to 3 of the present application have obvious advantages over comparative examples 1 to 7 in terms of mechanical properties, waterproof properties, chemical corrosion resistance, electrical properties and aging resistance. This is mainly due to the combined effect of the modified resin raw materials, modified particles and other matching schemes specified in the present application. Comparative examples 1 to 7 did not adopt the technical scheme specified in the present application, resulting in obvious disadvantages in the above performance tests. This further proves the necessity of the technical scheme specified in the present application for the technical effect of the present application and solving technical problems.

Claims

1. A chemical-resistant electroplating topcoat, characterized in that: Chemical-resistant electroplating topcoat, the raw materials are, by mass: 30-50 parts of modified acrylate, 15-30 parts of epoxy resin, 5-10 parts of modified particles, 3-6 parts of photoinitiator, 2-3 parts of leveling agent, 0.5-1 part of defoamer, 3-10 parts of pigment, and 20-40 parts of solvent; Preparation method of the modified acrylate The following steps are involved: S1: adding polytetramethylene glycol, bisphenol A polycarbonate diol and isophorone diisocyanate to a reaction vessel, heating to 80-95° C. and reacting for 3-3.5 hours. After the reaction is completed, filtering and washing the product to obtain a prepolymer; S2: adding isooctyl acrylate, isobornyl acrylate, pentaerythritol tetraacrylate and benzoyl peroxide, heating to 110-115° C., stirring at 140-160 rpm and reacting for 4-5 hours, then adding the prepolymer, continuing to keep warm and react for 1.5-2 hours until the reaction is complete to obtain a preproduct, finally adding acrylamide and potassium persulfate to the preproduct, cooling to 80-85° C., keeping warm and reacting for 3-4 hours to obtain a reaction product; S3: filtering the reaction product through a 400-600 mesh sieve to remove large particulate impurities, and the final product is sealed and stored away from light to obtain; The mass ratio of the isooctyl acrylate, isobornyl acrylate, pentaerythritol tetraacrylate and prepolymer is (15-20): (4.5-6): (1.5-1.8): (10-14); The mass ratio of the pre-product to acrylamide is (20-25): (3-4); The epoxy resin is a composition of bisphenol A epoxy resin and bisphenol F epoxy resin; the mass ratio of the bisphenol A epoxy resin to the bisphenol F epoxy resin is (3-5): (0.6-1.2).

2. The chemical-resistant electroplating topcoat according to claim 1, characterized in that: The mass ratio of the modified acrylate, epoxy resin and modified particles is (35-45): (18-24): (6-9).

3. The chemical-resistant electroplating topcoat according to claim 2, characterized in that: The epoxy value of the bisphenol A epoxy resin is 0.49 to 0.53 eq / 100 g; the epoxy value of the bisphenol F epoxy resin is 0.8 to 0.95 eq / 100 g.

4. The chemical-resistant electroplating topcoat according to claim 3, characterized in that: The preparation method of the modified particles comprises the following steps: S1: adding a mixture of silicon dioxide and ferric chloride hexahydrate to a DMF solution, adding glutaric anhydride and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, heating to 65-70° C. and maintaining the temperature for 2-3 hours; S2: adding a DMF solution containing terephthalic acid and 2-aminoterephthalic acid, adding acetic acid to adjust the pH value to 5.5-6, heating to 120-130° C. at 2.5° C. / min, and maintaining the temperature for reaction for 16-18 hours; S3: after the reaction is completed, naturally cooling to room temperature, adding triethanolamine to adjust the pH value to 7-7.5, cooling for 2-3 hours, centrifuging the product, washing with DMF and methanol, and drying in a vacuum oven at 70-80° C. to obtain the modified particles; The mass ratio of the silicon dioxide, ferric chloride hexahydrate, glutaric anhydride and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane is (1-1.2):(3-3.5):(0.5-0.8):(0.2-0.25); The mass ratio of the ferric chloride hexahydrate, terephthalic acid and 2-aminoterephthalic acid is (3-3.5): (0.6-0.8): (1-1.5).

5. The chemical-resistant electroplating topcoat according to claim 4, characterized in that: The average particle size of the silicon dioxide is 15 to 25 nm; the average particle size of the modified particles is 650 to 750 nm.

6. The chemical-resistant electroplating topcoat according to claim 5, characterized in that: The photoinitiator is at least one of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxycyclohexylphenyl ketone and 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

7. The chemical-resistant electroplating topcoat according to claim 6, characterized in that: The leveling agent is at least one of BYK-306, BYK-333, TEGO Flow 425 and Disparlon LVC-210.

8. The chemical-resistant electroplating topcoat according to claim 7, characterized in that: The solvent is a composition of butyl acetate and isophorone; the mass ratio of butyl acetate to isophorone is (3-4.5): (1.5-2).

9. A method for preparing the chemical-resistant electroplating topcoat according to any one of claims 1 to 8, characterized in that: The specific steps include: S1: adding modified acrylate, epoxy resin and solvent into a mixing container, stirring at a low speed of 40-60 rpm at room temperature until completely mixed, then adding modified particles, increasing the speed to 100-120 rpm and stirring at room temperature to obtain a mixture; S2: adding a photoinitiator, a leveling agent, a pigment and a defoaming agent into the mixture, stirring at room temperature at 100-120 rpm to obtain a uniform solution product; S3: filtering the obtained uniform solution product through a 400-600 mesh sieve to remove large granular impurities, and sealing the filtrate to protect from light to obtain the product.

10. Use of the chemical-resistant electroplating topcoat according to any one of claims 1 to 8 in cosmetic packaging.

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