阅读说明：本技术 一种新型木器漆涂料用丙烯酸酯乳液的制备方法 (Preparation method of novel acrylate emulsion for wood paint ) 是由 宋圣吉 赵兵 刘军 于 2019-10-05 设计创作，主要内容包括：本发明涉及一种新型木器漆涂料用丙烯酸酯乳液的制备方法。该丙烯酸酯乳液种子乳化剂采用双阴离子乳化剂组合,反应乳化剂采用无烷基酚羟基酯。该乳液是由烯类单体、乳化剂、烯类官能团单体、交联剂、乙烯基硅烷、过硫酸盐、成膜助剂和去离子水共聚而成。本发明引入双丙酮丙烯酰胺、N,N-亚甲基双丙烯酰胺其中一种和N-取代马来酰亚胺组合交联剂、乙烯基硅烷偶联剂参与共聚,环保安全,配制的胶粘制品比传统阴非乳化剂组合制丙烯酸酯乳液所得压敏胶具有不黄变、高剥离力等优点,同时断裂延伸率、抗拉强度、剥离强度大幅提高；同时引入成膜助剂与助成膜助剂,应用的木器漆具有干燥迅速、硬度高、透明性、耐沾污性等特点。(The invention relates to a preparation method of an acrylate emulsion for a novel wood lacquer coating. The acrylate emulsion seed emulsifier adopts the combination of double anionic emulsifiers, and the reaction emulsifier adopts alkylphenol hydroxyester without alkyl. The emulsion is prepared by copolymerizing an alkene monomer, an emulsifier, an alkene functional group monomer, a cross-linking agent, vinyl silane, persulfate, a film-forming aid and deionized water. One of diacetone acrylamide and N, N-methylene bisacrylamide is introduced to participate in copolymerization with an N-substituted maleimide combined cross-linking agent and a vinyl silane coupling agent, so that the environment is protected and safe, the prepared adhesive product has the advantages of no yellowing, high peeling force and the like compared with a pressure-sensitive adhesive prepared by preparing an acrylate emulsion by combining a traditional anionic emulsifier and a non-emulsifier, and the elongation at break, the tensile strength and the peeling strength are greatly improved; meanwhile, the film forming aid and the film forming aid are introduced, and the applied wood lacquer has the characteristics of rapid drying, high hardness, transparency, stain resistance and the like.)

1. A preparation method of acrylate emulsion for a novel wood lacquer coating is characterized in that the preparation method of the emulsion comprises the steps of adding an acrylate monomer, an anionic emulsifier, an initiator, an acrylate functional group monomer, a cross-linking agent and vinyl silane into water to obtain pre-emulsion A;

adding an initiator, a nonionic emulsifier and a pH buffering agent into water to obtain a solution B;

adding a proper amount of A (6-12 wt% of A) into B, heating until the solution turns blue to obtain a seed emulsion C, heating to the reaction temperature of 85 +/-2 ℃, dropwise adding the rest A and a film-forming aid (film-forming aid) into the seed emulsion C for 2-3 h, cooling to about 40 ℃ after finishing the dropwise addition reaction for 1-3 h, adjusting the pH value to be neutral, cooling and discharging.

2. The method for preparing the acrylic ester emulsion for the novel wood lacquer coating according to claim 1, wherein the pre-emulsion emulsifier is an anionic emulsifier which is a mixture of any two of sodium dodecyl benzene sulfonate, sodium methyl propenyl sulfonate and sodium dodecyl sulfate; the nonionic reactive emulsifier is propylene alcohol polyoxyethylene ether.

3. The method for preparing the acrylic ester emulsion for the novel wood lacquer coating according to claim 1, wherein the acrylic vinyl monomer comprises a mixture of any two or more of butyl acrylate, isooctyl acrylate, methyl methacrylate and ethyl acrylate.

4. The method for preparing the acrylate emulsion for the novel wood lacquer coating according to claim 1, wherein the acrylic acid alkene functional group monomer is methacrylic acid, hydroxyethyl acrylate or hydroxypropyl acrylate.

5. The method for preparing the novel acrylate emulsion for the wood lacquer coating as claimed in claim 1, wherein the initiator is ammonium persulfate or sodium persulfate, the film forming aid is 2,2, 4-trimethyl-1, 3-pentanediol monoisobutyrate, the film forming aid is dodecyl mercaptan, the pH buffering agent is sodium bicarbonate, and the pH value regulator is ammonia water.

6. The method for preparing the acrylate emulsion for the novel wood lacquer coating according to claim 1, wherein the vinyl silane is vinyl trimethoxy silane.

7. The method for preparing the acrylate emulsion for the novel wood lacquer coating according to claim 1, wherein the cross-linking agent is one of diacetone acrylamide and N, N-methylene bisacrylamide, and is a combination of N-substituted maleimide.

8. The method for preparing the acrylate emulsion for the novel wood lacquer coating according to claim 1, wherein the N-substituted maleimide is methyl, cyclohexyl, phenyl, hydroxyethyl, etc.

9. The preparation method of the novel acrylic ester emulsion for the wood lacquer coating as claimed in claim 1, wherein the total weight of the emulsion is 100 parts, the weight of vinyl monomer is 45-52 parts, the weight of anionic emulsifier is 1-2 parts, the weight of reactive nonionic emulsifier is 0.5-1.2 parts, the weight of methacrylic acid in the acrylic functional group monomer is 1.0-1.5 parts, the weight of acrylic hydroxy ester is 1.5-2 parts, the weight of cross-linking agent is 0.4-0.8 part, the weight of vinyl silane is 0.1-0.15 part, the weight of film forming auxiliary agent (film forming auxiliary agent) is 0.05-0.1 part, the weight of persulfate is 0.1-0.5 part, the weight of pH buffering agent is 0.03-0.1 part, and the weight of deionized water is 40-50 parts.

Technical Field

The invention relates to a novel acrylate emulsion for a wood lacquer coating, in particular to a novel environment-friendly, fast film-forming and anti-fouling acrylic emulsion for a wood lacquer coating.

Background

The woodware product plays an important role in indoor decoration and outdoor beautification, but is easily corroded by external environments such as moisture, bacteria and the like. At present, the wood lacquer is widely applied to wood products, not only plays a role in decoration, but also provides good protective properties such as corrosion resistance, ageing resistance and the like for the wood products.

The current woodware coating commonly used in the market is mainly solvent-based coating. However, the solvent-based coating contains a large amount of Volatile Organic Compounds (VOC), and the environment is seriously polluted and the human health is seriously harmed in the using process. With the development of social economy, the attention degree and requirements of people on living environment are improved, and more strict environmental regulations and export quality specifications are provided by relevant national departments, so that the reduction of the VOC content in the wood lacquer to gradually achieve the aim of no toxicity or low toxicity is urgent.

Emulsion type coating is one of green environmental protection coating, and becomes a research hotspot in recent years. But the water-based wood lacquer has low utilization rate, and the main reason is that the product still has technical defects, such as poor water resistance, hardness and wear resistance of a lacquer film. In addition, the polymer contained in the water-based wood paint has higher glass transition temperature, which means that under the condition of room temperature or lower environmental temperature, latex particles are difficult to deform, the particle fusion process is hindered, and the film forming speed is slow or the film cannot be formed.

The domestic similar widely used emulsion mainly comprises vinyl monomers, Alkylphenol (APEO) -containing (APEO), an emulsifier, an initiator, a pH value regulator and water. The emulsifier mainly adopts octyl, nonyl phenol anion and nonionic surfactant to combine and is used for producing the emulsion for wood lacquer, the pressure-sensitive adhesive produced generally has a plurality of defects of easy yellowing at high temperature, poor fracture elongation, poor tensile strength and peeling strength, and the like, especially the emulsion containing alkylphenol emulsifier is easy to damage the endocrine system of human body and adjacent species (fish). Therefore, the use of alkylphenol-containing emulsifiers in products has been restricted abroad.

In order to solve the problems of the water-based paint during use, the present invention is made in the following two aspects. (1) Starting from emulsion synthesis, preparing emulsion which has high glass transition temperature and can form film at low temperature, such as emulsion with a core/shell structure; the crosslinking monomer is added to cause chemical crosslinking between the active functional groups, so that the hardness and the water resistance of the paint film are obviously improved, the continuity of the paint film can be ensured, and good strength can be provided for the paint film.

Disclosure of Invention

The invention aims to solve the technical problem of providing the novel acrylate emulsion for the wood lacquer coating, which has the characteristics of environmental protection, quick film formation, strong stain resistance and the like. The emulsion used in the invention is polyacrylic copolymer emulsion with a core/shell structure, which is synthesized by taking acrylic ester as a main monomer, and matching with a plurality of functional monomers, a cross-linking agent and a film-forming auxiliary agent through a seed emulsion polymerization method.

In order to solve the technical problem, the preparation method of the emulsion comprises the steps of adding an acrylate monomer, an anionic emulsifier, an initiator, an acrylate functional group monomer, a cross-linking agent and vinyl silane into water to obtain a pre-emulsion A, adding the initiator, a nonionic emulsifier and a pH buffering agent into water to obtain a solution B, adding a proper amount of A (6-12 wt% of A) into the solution B, heating until the solution turns blue to obtain a seed emulsion C, heating to a reaction temperature of 85 +/-2 ℃, dropwise adding the rest A and a film-forming aid (film-forming aid) into the seed emulsion C for 2-3 h, cooling to about 40 ℃ after finishing a heat preservation reaction for 1-3 h, adjusting the pH value to be neutral, cooling and discharging.

The acrylic vinyl monomer comprises a mixture of any two or more of butyl acrylate, isooctyl acrylate, methyl methacrylate and ethyl acrylate; the seed emulsion emulsifier anionic emulsifier is the combination of any two of sodium dodecyl benzene sulfonate, sodium methyl propenyl sulfonate and sodium dodecyl sulfate; the nonionic reactive emulsifier is propylene alcohol polyoxyethylene ether; the acrylic functional group monomer is methacrylic acid, hydroxyethyl acrylate or hydroxypropyl acrylate; the pH buffer is sodium bicarbonate, and the pH value regulator is ammonia water; the cross-linking agent is one of diacetone acrylamide and N, N-methylene bisacrylamide which is combined with N-substituted maleimide; the film forming auxiliary agent is 2,2, 4-trimethyl-1, 3-pentanediol monoisobutyrate, and the film forming auxiliary agent is dodecyl mercaptan; the coupling agent is vinyl trimethoxy silane.

Based on 100 parts of the total weight of the emulsion, 45-52 parts of vinyl monomer, 1-2 parts of anionic emulsifier, 0.5-1.2 parts of reactive nonionic emulsifier, 1.0-1.5 parts of methacrylic acid, 1.5-2 parts of hydroxy acrylate, 0.4-0.8 part of cross-linking agent, 0.1-0.15 part of vinyl silane, 0.1-0.25 part of film forming auxiliary agent (film forming auxiliary agent), 0.1-0.5 part of persulfate, 0.03-0.1 part of pH buffering agent and 40-50 parts of deionized water.

The invention has the following beneficial effects: (1) the seed emulsion emulsifier is prepared by combining two anionic emulsifiers and has the advantages of good stability, narrow particle size distribution, easy control and the like; (2) the reaction emulsifier adopts a completely alkyl-free phenol emulsifier to replace the original emulsifier as an emulsifying system, so that the product is more environment-friendly and the pressure-sensitive adhesive is not yellowed at high temperature; (3) the vinyl silane coupling agent is introduced into the copolymer, so that the adhesive force and the tensile strength of the product on an inorganic organic substrate can be improved by times; (4) the former introduces film-forming assistant and cross-linking agent, the former makes the polymer emulsion have lower film-forming temperature, the emulsion type coating can be applied to construction under low temperature condition, the temperature range of coating construction is enlarged, the latter makes chemical cross-linking occur between active functional groups, the hardness and water resistance are obviously improved, the continuity of the paint film can be ensured, good strength can be provided for the paint film, and the mechanical property, weather resistance and stain resistance of the paint film can be improved.

The applied wood lacquer coating has the advantages of most of the conventional acrylic emulsion wood lacquer, and also has the characteristics of rapid drying, high hardness, transparency, good fluidity, stain resistance, excellent chemical resistance, better low-temperature flexibility, better adhesion resistance and the like.

Detailed Description

The formulation (based on 100 parts by weight) for producing the acrylate emulsion from the novel emulsifier combination of the invention is further described below.

The formulation (based on 100 parts by weight) for producing the acrylate emulsion from the novel emulsifier combination of the invention is further described below.