Preparation method of resin for environment-friendly water-based electrosilvering coating

Abstract

The invention belongs to the technical field of water-based organic resin, and particularly relates to a preparation method of resin for an environment-friendly water-based electrosilvering coating. According to the environment-friendly water-based electrosilvering coating resin and the preparation method thereof, the acrylic acid monomer and the carboxylic acid monomer containing various functional groups are added into the raw materials in the prior art, and the environment-friendly water-based electrosilvering coating resin prepared through co-modification of the epoxy resin, the silanized graphene oxide and the silane coupling agent is good in adhesive force with a substrate and has good salt fog resistance and scratch resistance; the organic solvent used in the preparation process does not contain triphenyl organic solvents and is low in toxicity and environmentally friendly, the raw materials of the resin are wide in source and relatively low in cost, and the prepared environment-friendly water-based electrosilvering coating resin has good fluidity, controllable viscosity and easy construction.

Description

Technical Field

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

[0002] Electroplating silver paint is one of the top coating materials in the world. After being coated with this product, it can achieve the electroplating effect, which can significantly increase the appearance of the product and extend the service life of the product. Electroplating silver paint is made of electroplating silver resin, liquid aluminum silver paste, mixed solvent and additives. Traditional solvent-based paint contains too many volatile organic compounds due to the use of organic solvents. Water-based paint does not contain volatile organic compounds or its content is extremely low, which greatly reduces the pollution to the environment and the harm to human health, and has excellent environmental protection performance.

[0003] The electroplating silver resin used in patent CN116855143A is a modified acrylic polymer resin with a low hydroxyl value, good silver row effect, and excellent adhesion to ABS / ABS+PC; the water-based electroplating silver resin used in patent CN111117399A includes a water-based acrylic emulsion with a carboxyl group on the side chain, with a solid content of 30-50 ωt%, free acrylic monomer ≤ 0.5wt%, and a limiting viscosity of 0.06-0.10dl / g. Water-based acrylic resin has excellent properties such as high hardness and good color retention, but it has shortcomings in terms of stain resistance, water resistance and corrosion resistance. Therefore, researchers have introduced some functional monomers or modified materials to improve the performance of the coating. Patent CN116444738B uses 5 to 30 parts by weight of epoxy resin, 3 to 5 parts by weight of hydroxy-carboxylic acid derivatives, and 100 to 120 parts by weight of mixed monomers, including 3 to 10 parts by weight of sulfonic acid group-containing alkenyl monomers, 3 to 20 parts by weight of hydroxyl group-containing alkenyl monomers and the remainder of acrylic acid monomers to prepare an epoxy-modified acrylic acid aqueous dispersion with good stability, salt spray resistance and solvent scratch resistance. However, the prior art has the problems of poor adhesion between a single resin and a substrate and greater environmental pollution in the preparation process, and there is no technical problem of enhancing the adhesion between the resin and 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 silver electroplating paint resin, which is used to solve the technical problems in the prior art that the adhesion between a single resin and a substrate is poor, 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 silver electroplating paint resin comprises the following steps:

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

[0008] S2, adding epoxy resin and solvent into the reaction kettle, heating the reaction kettle and controlling the temperature to 75-80°C, and dripping reaction solution A into the reaction kettle under nitrogen protection for 3-4 hours;

[0009] S3, after the reaction solution A is added dropwise, the reaction is carried out at 75-80°C for 1-2h, and a silane coupling agent and silanized graphene are added dropwise, and after the addition is completed, the reaction is carried out at 75-80°C for 0.5-2h;

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

[0011] S5. The reaction kettle is cooled to 70-75° C., a pH regulator and deionized water are added dropwise under stirring, and the mixture is stirred for 0.5-1 h to obtain an environmentally friendly water-based silver electroplating paint resin.

[0012] Preferably, the environmentally friendly water-based silver electroplating paint 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 isopropanol, 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 adjuster 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 the environmentally friendly water-based silver electroplating 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 a 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 technical solutions in the embodiments of the present invention are described clearly and completely below. 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 creative work are within the scope of protection of the present invention.

[0024] Embodiment 1, the preparation method of the environmentally friendly water-based electroplating silver coating resin of this embodiment comprises the following steps:

[0025] S1. According to weight parts, 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, add 30 parts of E51 epoxy resin and 80 parts of isopropanol into the reactor, heat the reactor and control the temperature to 80°C, and dropwise add reaction solution A into the reactor under nitrogen protection for 4 hours;

[0027] S3, after the reaction solution A is added dropwise, react at 80°C for 1 hour, then add 3 parts of KH-151 silane coupling agent and 3 parts of silylated graphene oxide GO-551 dropwise, and react at 80°C for 0.5 hour;

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

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

[0030] Embodiment 2, the preparation method of the environmentally friendly water-based silver electroplating paint resin of this embodiment comprises the following steps:

[0031] S1. According to weight parts, 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 isopropanol into the reactor, heat the reactor and control the temperature to 80°C, and dropwise add reaction solution A into the reactor under nitrogen protection for 3 hours;

[0033] S3, after the reaction solution A is added dropwise, react at 80°C for 1 hour, then add 3 parts of KH-151 silane coupling agent and 3 parts of silylated graphene oxide GO-551 dropwise, and react at 80°C for 0.5 hour;

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

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

[0036] Embodiment 3, the preparation method of the environmentally friendly water-based silver electroplating paint resin of this embodiment comprises the following steps:

[0037] S1. According to weight parts, 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, add 30 parts of E51 epoxy resin and 60 parts of isopropanol into the reactor, heat the reactor and control the temperature to 80°C, and dropwise add reaction solution A into the reactor under nitrogen protection for 3 hours;

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

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

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

[0042] Embodiment 4, the preparation method of the environmentally friendly water-based silver electroplating paint 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 isopropanol into the reactor, heat the reactor and control the temperature to 80°C, and dropwise add reaction solution A into the reactor under nitrogen protection for 3 hours;

[0045] S3, after the reaction solution A is added dropwise, react at 80°C for 2h, then 4 parts of KH-151 silane coupling agent and 4 parts of silylated graphene oxide GO-551 are added dropwise, and react at 80°C for 1h after the addition is completed;

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

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

[0048] Embodiment 5, the preparation method of the environmentally friendly water-based silver electroplating paint resin of this embodiment comprises the following steps:

[0049] S1. According to weight parts, 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, add 10 parts of E55 epoxy resin and 60 parts of propyl acetate into the reactor, heat the reactor and control the temperature to 75°C, and dropwise add reaction solution A into the reactor under nitrogen protection for 4 hours;

[0051] S3, after the reaction solution A is added dropwise, react at 75°C for 1 hour, then add 5 parts of KH-570 silane coupling agent and 5 parts of silylated graphene oxide GO-551 dropwise, and react at 80°C for 2 hours;

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

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

[0054] Embodiment 6, the preparation method of the environmentally friendly water-based silver electroplating paint resin of this embodiment comprises the following steps:

[0055] S1. According to weight parts, 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 reaction solution A;

[0056] S2, add 10 parts of E20 epoxy resin and 60 parts of propyl acetate into the reactor, heat the reactor and control the temperature to 75°C, and dropwise add reaction solution A into the reactor under nitrogen protection for 3 hours;

[0057] S3, after the reaction solution A is added dropwise, react at 75°C for 2h, then add 5 parts of KH-602 silane coupling agent and 5 parts of silylated graphene oxide GO-551 dropwise, and react at 80°C for 2h after the addition is complete;

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

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

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

[0061] Comparative Example 2: This comparative example differs from Example 1 in 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: The difference between this comparative example and Example 1 is that the amount of silane coupling agent is changed to 20 parts and the amount of silanized graphene oxide is changed to 20 parts.

[0064] Test Case

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

[0066] Spray paint coating: The electroplated silver paint obtained above was sprayed on a steel flat 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 “Determination of appearance and transparency of varnishes, oils and thinners”, the physical states 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 neutral salt spray resistance of paints and varnishes", the test coating thickness is 90-120μm, and the salt spray resistance damage evaluation standard is unilateral rust diffusion >2mm or coating blistering.

[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 coating film impact resistance test was carried out according to the standard of 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 “Determination of film hardness of paints and varnishes by pencil method”, and the pencil used for the test was 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 blue in appearance, indicating that the resins prepared have good stability, high water solubility and high raw material synthesis efficiency. The salt spray resistance of the prepared electroplated silver coatings after coating is all above 26 days, indicating that they have excellent corrosion resistance and salt spray resistance; the adhesion level 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 40kg×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 product appearance quality, further indicating that the resin prepared by the present invention has excellent corrosion resistance and salt spray resistance, high stability and mechanical properties, high water solubility, and is environmentally friendly.

[0084] It can be seen from the data in Table 1 that 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 obtained 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, excessive crosslinking of the reaction monomer, and the viscosity of the obtained 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 there are too many monomer impurities in the resin, resulting in its appearance becoming a translucent resin and its stability, salt spray resistance, substrate adhesion, and mechanical properties are 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 graphene depolymerize to form a cross-linked network, resulting in increased resin viscosity and poor water solubility, resulting in its appearance becoming milky white, and its stability, salt spray resistance, substrate adhesion, and mechanical properties are reduced.

[0085] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

[0086] The preferred embodiments of the present invention disclosed above are only used to help explain the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only specific implementation methods. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. 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 silver electroplating paint resin, characterized in that: The steps include: S1, mixing acrylic acid, hydroxyethyl methacrylate, methyl methacrylate, diethylaminoethyl methacrylate, itaconic acid and an initiator to prepare a reaction solution A; S2, adding epoxy resin and solvent into the reaction kettle, heating the reaction kettle and controlling the temperature to 75-80°C, and dripping reaction solution A into the reaction kettle 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 1-2h, 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 0.5-2h; S4, after keeping warm for 1 to 3 hours, distilling off the solvent under reduced pressure; S5. The reaction kettle is cooled to 70-75° C., a pH regulator and deionized water are added dropwise under stirring, and the mixture is stirred for 0.5-1 h to obtain an environmentally friendly water-based silver electroplating paint resin.

2. The method for preparing an environmentally friendly water-based silver electroplating paint resin according to claim 1, characterized in that: 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 silylated graphene oxide, and 1 to 3 parts of pH regulator.

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

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

5. The method for preparing an environmentally friendly water-based silver electroplating paint resin according to claim 1, characterized in that: 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 silver electroplating paint resin according to claim 1, characterized in that: In the above S5, the pH adjuster is any one of diethylaminopropylamine, tripropylamine and hydroxyethylethylenediamine.

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

Images