Preparation method of environmentally friendly water-based silver electroplating paint resin

Abstract

The present invention belongs to the technical field of water-based organic resins, and specifically relates to a method for preparing an environmentally friendly water-based electroplated silver coating resin. The present invention adds acrylic acid monomers and carboxylic acid monomers containing multiple functional groups to the raw materials of the prior art, and co-modifies the mixture with an epoxy resin, silylated graphene oxide, and a silane coupling agent. The resulting environmentally friendly water-based electroplated silver coating resin has excellent adhesion to the substrate, good salt spray resistance, and good scratch resistance. The organic solvent used in the preparation process does not contain "triphenyl" organic solvents and is low in toxicity, making it environmentally friendly. The resin raw materials are widely available and relatively low in cost. The environmentally friendly water-based electroplated silver coating resin prepared by the present invention has good fluidity, controllable viscosity, and is easy to apply.

Description

Technical Field

[0001] The invention belongs to the technical field of water-based organic resins, and particularly relates to a method for preparing an environmentally friendly water-based resin for electroplating silver coatings. Background Art

[0002] Electroplated silver paint is one of the world's top coating materials. It creates a plating effect, significantly enhancing a product's aesthetics and extending its lifespan. Electroplated silver paint is formulated with electroplated silver resin, liquid aluminum-silver paste, a mixed solvent, and additives. Traditional solvent-based paints, due to their use of organic solvents, contain excessive amounts of volatile organic compounds (VOCs). Water-based paints contain no VOCs or contain very low levels of VOCs, significantly reducing environmental pollution and harm to human health, and exhibiting excellent environmental performance.

[0003] The electroplating silver resin used in patent CN116855143A is a modified acrylic polymer resin with a low hydroxyl value, good silver removal performance, and excellent adhesion to ABS / ABS+PC. Patent CN111117399A uses a water-based electroplating silver resin consisting of a water-based acrylic emulsion with carboxyl groups on its side chains. It has a solids content of 30-50wt%, ≤0.5wt% free acrylic monomer, and an intrinsic viscosity of 0.06-0.10 dl / g. While water-based acrylic resins offer excellent properties such as high hardness and color retention, they lack resistance to stains, water, and corrosion. Therefore, researchers have introduced functional monomers or modified materials to improve the coating's performance. Patent CN116444738B uses 5 to 30 parts by weight of epoxy resin, 3 to 5 parts by weight of hydroxy-carboxylic acid derivative, and 100 to 120 parts by weight of mixed monomers, including 3 to 10 parts by weight of sulfonic acid group-containing alkenyl monomer, 3 to 20 parts by weight of hydroxyl group-containing alkenyl monomer, and the remainder of acrylic acid monomer to prepare an epoxy-modified acrylic acid aqueous dispersion with good stability, salt spray resistance, and solvent scratch resistance. However, the existing technology has the following problems: the adhesion of the single resin to the substrate is poor, the preparation process causes great environmental pollution, and there is no technical problem of enhancing the adhesion of the resin to the substrate by adding modified nanomaterials. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for preparing an environmentally friendly water-based electrosilver plating resin, which is used to solve the technical problems in the prior art that a single resin has poor adhesion to a substrate, the preparation process causes great environmental pollution, and no modified nanomaterials are added to enhance the adhesion between the resin and the substrate.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing an environmentally friendly water-based resin for electroplating silver coating comprises the following steps:

[0007] S1, acrylic acid, hydroxyethyl methacrylate, methyl methacrylate, diethylaminoethyl methacrylate, itaconic acid and an initiator are mixed to prepare a reaction solution A;

[0008] S2. Add epoxy resin and solvent into the reactor, heat the reactor and control the temperature to 75-80°C, and add reaction solution A dropwise into the reactor under nitrogen protection for 3-4 hours;

[0009] S3. After the reaction solution A is added dropwise, the mixture is reacted at 75-80°C for 1-2 hours, and a silane coupling agent and silanized graphene are added dropwise. After the addition is completed, the mixture is reacted at 75-80°C for 0.5-2 hours;

[0010] S4, after keeping warm for 1 to 3 hours, distilling off the solvent under reduced pressure;

[0011] S5. Cool the reactor to 70-75° C., add a pH regulator and deionized water dropwise while stirring, and stir for 0.5-1 hour to obtain an environmentally friendly water-based resin for silver electroplating coating.

[0012] Preferably, the environmentally friendly water-based electroplating silver coating resin of the present invention is prepared by using the following components in parts by weight: 60 to 70 parts of acrylic acid, 5 to 10 parts of hydroxyethyl methacrylate, 5 to 10 parts of methyl methacrylate, 5 to 10 parts of diethylaminoethyl methacrylate, 5 to 20 parts of itaconic acid and 1 to 5 parts of initiator, 10 to 30 parts of epoxy resin, 60 to 80 parts of solvent, 3 to 5 parts of silane coupling agent, 1 to 5 parts of silanized graphene oxide, and 1 to 3 parts of pH regulator.

[0013] Preferably, the initiator in S1 is any one of ammonium persulfate and azobisisobutyronitrile.

[0014] Preferably, the epoxy resin in S2 is any one of E20, E51, and E55.

[0015] Preferably, the solvent in S2 is any one of isopropyl alcohol, propyl acetate, and isobutyl acetate.

[0016] Preferably, the silane coupling agent in S3 is any one of KH-151, KH-570, and KH-602, and the silanized graphene oxide is GO-551.

[0017] Preferably, in S5, the pH regulator is any one of diethylaminopropylamine, tripropylamine, and hydroxyethylethylenediamine.

[0018] Preferably, in S5, deionized water is added to adjust the resin solid content to 40-50%, and the stirring speed is 300-500 rpm.

[0019] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0020] 1. The present invention adds acrylic monomers and carboxylic acid monomers containing multiple functional groups to the raw materials of the prior art, and prepares an environmentally friendly water-based electroplating silver coating resin by co-modification with epoxy resin, silylated graphene oxide and silane coupling agent. The resin has good adhesion to the substrate and has good salt spray resistance and scratch resistance.

[0021] 2. The present invention uses epoxy resin to modify acrylic resin to improve the salt spray resistance, adhesion and corrosion resistance of the resin.

[0022] 3. The present invention uses silanized graphene oxide and silane coupling agent to co-modify acrylic resin, which significantly improves the mechanical properties and corrosion resistance of the resin, enhances the adhesion between the resin and the substrate, increases the service life of the resin, and makes the resin have good fluidity, controllable viscosity, and easy construction. DETAILED DESCRIPTION

[0023] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments 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 embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0024] Example 1: The method for preparing the environmentally friendly water-based silver electroplating paint resin of this embodiment comprises the following steps:

[0025] S1. According to parts by weight, 60 parts of acrylic acid, 10 parts of hydroxyethyl methacrylate, 10 parts of methyl methacrylate, 10 parts of diethylaminoethyl methacrylate, 10 parts of itaconic acid and 3 parts of azobisisobutyronitrile were mixed to prepare a reaction solution A;

[0026] S2, 30 parts of E51 epoxy resin and 80 parts of isopropyl alcohol were added to the reactor, the reactor temperature was raised and controlled to 80°C, and reaction solution A was added dropwise to the reactor under nitrogen protection for 4 hours;

[0027] S3. After the reaction solution A is added dropwise, the mixture is reacted at 80°C for 1 hour, and then 3 parts of KH-151 silane coupling agent and 3 parts of silanized graphene oxide GO-551 are added dropwise. After the addition is completed, the mixture is reacted at 80°C for 0.5 hour.

[0028] S4, after keeping warm for 2 hours, distill off isopropyl alcohol under reduced pressure at 75°C;

[0029] S5. The reactor was cooled to 70° C., and 3 parts of diethylaminopropylamine and deionized water were added dropwise under stirring to adjust the solid content of the resin to 40%. After stirring for 0.5 h, an environmentally friendly water-based resin for electroplating silver coating was obtained.

[0030] Example 2: The method for preparing the environmentally friendly water-based silver electroplating paint resin of this embodiment comprises the following steps:

[0031] S1. According to parts by weight, 60 parts of acrylic acid, 5 parts of hydroxyethyl methacrylate, 5 parts of methyl methacrylate, 10 parts of diethylaminoethyl methacrylate, 20 parts of itaconic acid and 5 parts of azobisisobutyronitrile were mixed to prepare a reaction solution A;

[0032] S2. Add 10 parts of E51 epoxy resin and 60 parts of isopropyl alcohol into a reactor, heat the reactor and control the temperature to 80°C, and add reaction solution A dropwise into the reactor under nitrogen protection for 3 hours;

[0033] S3. After the reaction solution A is added dropwise, the mixture is reacted at 80°C for 1 hour, and then 3 parts of KH-151 silane coupling agent and 3 parts of silanized graphene oxide GO-551 are added dropwise. After the addition is completed, the mixture is reacted at 80°C for 0.5 hour.

[0034] S4, after keeping warm for 2 hours, distill off isopropyl alcohol under reduced pressure at 75°C;

[0035] S5. The reactor was cooled to 70° C., and 3 parts of diethylaminopropylamine and deionized water were added dropwise under stirring to adjust the solid content of the resin to 40%. After stirring for 0.5 h, an environmentally friendly water-based resin for electroplating silver coating was obtained.

[0036] Example 3: The method for preparing the environmentally friendly water-based electroplating silver coating resin of this embodiment comprises the following steps:

[0037] S1. According to parts by weight, 70 parts of acrylic acid, 5 parts of hydroxyethyl methacrylate, 5 parts of methyl methacrylate, 10 parts of diethylaminoethyl methacrylate, 10 parts of itaconic acid and 3 parts of azobisisobutyronitrile were mixed to prepare a reaction solution A;

[0038] S2, 30 parts of E51 epoxy resin and 60 parts of isopropyl alcohol were added to the reactor, the reactor temperature was raised and controlled at 80°C, and reaction solution A was added dropwise to the reactor under nitrogen protection for 3 hours;

[0039] S3, after the reaction solution A is added dropwise, the mixture is reacted at 80°C for 1 hour, and then 3 parts of KH-151 silane coupling agent and 3 parts of silylated graphene oxide are added dropwise, and the mixture is reacted at 80°C for 0.5 hour;

[0040] S4, after keeping warm for 1 hour, distill off isopropyl alcohol under reduced pressure at 75°C;

[0041] S5. The reactor was cooled to 70° C., and 3 parts of diethylaminopropylamine and deionized water were added dropwise under stirring to adjust the solid content of the resin to 50%. After stirring for 0.5 h, an environmentally friendly water-based resin for electroplating silver coating was obtained.

[0042] Example 4: The method for preparing the environmentally friendly water-based electroplating silver coating resin of this embodiment comprises the following steps:

[0043] S1. According to parts by weight, 80 parts of acrylic acid, 5 parts of hydroxyethyl methacrylate, 5 parts of methyl methacrylate, 5 parts of diethylaminoethyl methacrylate, 5 parts of itaconic acid and 3 parts of azobisisobutyronitrile were mixed to prepare a reaction solution A;

[0044] S2, add 20 parts of E51 epoxy resin and 80 parts of isopropyl alcohol into the reactor, heat the reactor and control the temperature to 80°C, and add reaction solution A dropwise into the reactor under nitrogen protection for 3 hours;

[0045] S3. After the reaction solution A is added dropwise, the mixture is reacted at 80°C for 2 hours, and then 4 parts of KH-151 silane coupling agent and 4 parts of silanized graphene oxide GO-551 are added dropwise. After the addition is completed, the mixture is reacted at 80°C for 1 hour.

[0046] S4, after keeping warm for 1 hour, distill off isopropyl alcohol under reduced pressure at 75°C;

[0047] S5. The reactor was cooled to 70° C., and 3 parts of tripropylamine and deionized water were added dropwise under stirring to adjust the solid content of the resin to 50%. After stirring for 1 hour, an environmentally friendly water-based resin for electroplating silver coating was obtained.

[0048] Example 5: The method for preparing the environmentally friendly water-based electroplating silver coating resin of this embodiment comprises the following steps:

[0049] S1. According to parts by weight, 60 parts of acrylic acid, 10 parts of hydroxyethyl methacrylate, 10 parts of methyl methacrylate, 10 parts of diethylaminoethyl methacrylate, 10 parts of itaconic acid and 3 parts of azobisisobutyronitrile were mixed to prepare a reaction solution A;

[0050] S2, 10 parts of E55 epoxy resin and 60 parts of propyl acetate were added to the reactor, the reactor was heated and the temperature was controlled at 75 ° C, and reaction solution A was added dropwise to the reactor under nitrogen protection for 4 hours;

[0051] S3. After the reaction solution A is added dropwise, the mixture is reacted at 75°C for 1 hour, and then 5 parts of KH-570 silane coupling agent and 5 parts of silanized graphene oxide GO-551 are added dropwise. After the addition is completed, the mixture is reacted at 80°C for 2 hours.

[0052] S4, after keeping warm for 3 hours, distilling off propyl acetate under reduced pressure at 80°C;

[0053] S5. The reactor was cooled to 70° C., and 3 parts of hydroxyethylethylenediamine and deionized water were added dropwise under stirring to adjust the solid content of the resin to 45%. After stirring for 1 hour, an environmentally friendly water-based resin for electroplating silver coating was obtained.

[0054] Example 6: The method for preparing the environmentally friendly water-based electroplating silver coating resin of this embodiment comprises the following steps:

[0055] S1. According to parts by weight, 60 parts of acrylic acid, 10 parts of hydroxyethyl methacrylate, 10 parts of methyl methacrylate, 10 parts of diethylaminoethyl methacrylate, 10 parts of itaconic acid and 1 part of azobisisobutyronitrile were mixed to prepare a reaction solution A;

[0056] S2, 10 parts of E20 epoxy resin and 60 parts of propyl acetate were added to the reactor, the reactor temperature was raised and controlled to 75°C, and reaction solution A was added dropwise to the reactor under nitrogen protection for 3 hours;

[0057] S3. After the reaction solution A is added dropwise, the mixture is reacted at 75°C for 2 h, and then 5 parts of KH-602 silane coupling agent and 5 parts of silanized graphene oxide GO-551 are added dropwise. After the addition is complete, the mixture is reacted at 80°C for 2 h.

[0058] S4, after keeping warm for 2 hours, distilling off propyl acetate under reduced pressure at 80°C;

[0059] S5. The reaction kettle was cooled to 70° C., and 3 parts of hydroxyethylethylenediamine and deionized water were added dropwise under stirring to adjust the solid content of the resin to 45%. After stirring for 0.5 h, an environmentally friendly water-based resin for electroplating silver coating was obtained.

[0060] Comparative Example 1: The difference between this comparative example and Example 1 is that the amount of epoxy resin used is changed to 50 parts.

[0061] Comparative Example 2: The difference between this comparative example and Example 1 is that the amount of initiator used is changed to 10 parts.

[0062] Comparative Example 3: This comparative example differs from Example 1 in that the amount of itaconic acid used is changed to 50 parts.

[0063] Comparative Example 4: This comparative example differs from Example 1 in that the amount of the silane coupling agent is changed to 20 parts and the amount of the silanized graphene oxide is changed to 20 parts.

[0064] Test Case

[0065] Preparation of electroplated silver coating: 100 g of each of the resins prepared in Examples 1 to 6 and Comparative Examples 1 to 4 was taken, 500 g of ethyl acetate diluent was added, and then 20 g of electroplated silver aluminum silver paste, 5 g of epoxy resin leveling agent, 5 g of DH-6900 anti-settling agent, and 5 g of FD-470 defoaming agent were added at a stirring speed of 500 rpm to prepare an electroplated silver coating.

[0066] Spray coating: The electroplated silver coating obtained above was sprayed on a steel plate (75 mm × 150 mm) that had been sandblasted and cleaned, and cured and dried at 80° C. for 0.5 to 1 h.

[0067] Appearance test

[0068] According to GB / T 1721-2008 “Varnishes, oils and thinners, determination of appearance and transparency”, the physical properties of the prepared resin samples such as color, appearance, uniformity, transparency, and fluidity were observed.

[0069] Salt spray resistance test

[0070] According to GB / T 1771-2007 "Determination of resistance of paints and varnishes to neutral salt spray", the test coating thickness is 90-120μm, and the salt spray damage resistance evaluation standard is unilateral spread of rust >2mm or blistering of the coating.

[0071] Adhesion test

[0072] According to GB / T 1720-1979 "Determination of adhesion of paint and varnish films", the coating thickness is 20-30μm, and the adhesion test experiment is carried out after the coating film is dried and cured for 24 hours.

[0073] Impact resistance test

[0074] The impact resistance test of the coating film was carried out in accordance with the standard GB / T 1732-1993 "Determination of impact resistance of paint films", and the test coating film thickness was 20 to 30 μm.

[0075] Coating gloss test

[0076] According to GB / T 1743-1979 "Determination of gloss of paint films", use a gloss meter to test the gloss of the coating film.

[0077] Hardness test

[0078] The coating hardness was tested according to GB / T 6739-2006 “Paints and varnishes - Determination of film hardness by pencil method”, using a Zhonghua brand pencil.

[0079] The test results are shown in Table 1 below:

[0080] Table 1

[0081]

[0082]

[0083] As can be seen from the data in Table 1, the resins prepared in Examples 1 to 6 are transparent and have a bluish appearance, indicating that the resins prepared have good stability, high water solubility, and high raw material synthesis efficiency. The salt spray resistance of the electroplated silver coatings after coating is all above 26 days, indicating excellent corrosion resistance and salt spray resistance; the adhesion grade is all level 1, indicating that the added silane coupling agent and silanized graphene oxide can improve the adhesion between the resin and the substrate; the impact resistance is above 40 kg×cm and the hardness is 2H to 3H, indicating that the resin can enhance the mechanical properties of the coating; the coating gloss is between 83% and 85%, indicating that the resins prepared in Examples 1 to 6 can improve the gloss of the electroplated silver coating and thus improve the appearance quality of the product, further demonstrating that the resins prepared by the present invention have excellent corrosion resistance and salt spray resistance, high stability and mechanical properties, high water solubility, and are environmentally friendly.

[0084] As can be seen from the data in Table 1, the increase in the amount of epoxy resin in Comparative Example 1 improves the hardness of the electroplated silver coating film to a certain extent, but the large amount of epoxy resin leads to insufficient monomer grafting reaction, so the water solubility of the resin is poor, the appearance becomes a translucent resin, and the stability, salt spray resistance and substrate adhesion are significantly reduced; the large amount of initiator in Comparative Example 2 leads to excessive reaction rate and excessive crosslinking of the reaction monomer, so that the viscosity of the resin is too high and the stability is poor, which leads to poor stability, salt spray resistance, substrate adhesion and adhesion. The mechanical properties of the resin are reduced; in Comparative Example 3, the amount of itaconic acid used is too high, resulting in incomplete reaction and excessive monomer impurities in the resin, causing its appearance to become a translucent resin and its stability, salt spray resistance, substrate adhesion, and mechanical properties to be reduced; in Comparative Example 4, the amount of silane coupling agent and silanized graphene oxide used is too much. During the reaction, the silane coupling agent and silanized graphene oxide depolymerize to form a cross-linked network, resulting in increased resin viscosity and poor water solubility, causing its appearance to become milky white, and its stability, salt spray resistance, substrate adhesion, and mechanical properties to be reduced.

[0085] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

[0086] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to specific embodiments. Obviously, many modifications and variations are possible based on the contents of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing an environmentally friendly water-based resin for electroplating silver coating, characterized in that: The steps include: S1, acrylic acid, hydroxyethyl methacrylate, methyl methacrylate, diethylaminoethyl methacrylate, itaconic acid and an initiator are mixed to prepare a reaction solution A; S2. Add epoxy resin and solvent into the reactor, heat the reactor and control the temperature to 75-80°C, and add reaction solution A dropwise into the reactor under nitrogen protection for 3-4 hours; S3. After the reaction solution A is added dropwise, the mixture is reacted at 75-80°C for 1-2 hours, and a silane coupling agent and silylated graphene oxide are added dropwise. After the addition is completed, the mixture is reacted at 75-80°C for 0.5-2 hours; S4, after keeping warm for 1 to 3 hours, distilling off the solvent under reduced pressure; S5. Cool the reactor to 70-75° C., add a pH regulator and deionized water dropwise while stirring, and stir for 0.5-1 hour to obtain an environmentally friendly water-based resin for silver electroplating coating.

2. The method for preparing an environmentally friendly water-based silver electroplating paint resin according to claim 1, wherein: The weight parts of the components used in preparing the resin for environmentally friendly water-based electroplating silver coating are as follows: 60 to 80 parts of acrylic acid, 5 to 10 parts of hydroxyethyl methacrylate, 5 to 10 parts of methyl methacrylate, 5 to 10 parts of diethylaminoethyl methacrylate, 5 to 20 parts of itaconic acid and 1 to 5 parts of initiator, 10 to 30 parts of epoxy resin, 60 to 80 parts of solvent, 3 to 5 parts of silane coupling agent, 1 to 3 parts of silanized graphene oxide, and 1 to 3 parts of pH regulator.

3. The method for preparing an environmentally friendly water-based electroplating silver coating resin according to claim 1, wherein: The initiator in S1 is any one of ammonium persulfate and azobisisobutyronitrile.

4. The method for preparing an environmentally friendly water-based electroplating silver coating resin according to claim 1, wherein: The epoxy resin in S2 is any one of E20, E51, and E55, and the solvent is any one of isopropyl alcohol, propyl acetate, and isobutyl acetate.

5. The method for preparing an environmentally friendly water-based electroplating silver coating resin according to claim 1, wherein: The silane coupling agent in S3 is any one of KH-151, KH-570, and KH-602, and the silanized graphene oxide is GO-551.

6. The method for preparing an environmentally friendly water-based electroplating silver coating resin according to claim 1, wherein: In the above-mentioned S5, the pH adjuster is any one of diethylaminopropylamine, tripropylamine, and hydroxyethylethylenediamine.

7. The method for preparing an environmentally friendly water-based resin for electroplating silver paint according to claim 1, wherein: Deionized water is added to the S5 to adjust the resin solid content to 40-50%, and the stirring speed is 300-500 rpm.

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