Modified hydroxyl acrylic emulsion and preparation method thereof

Abstract

The invention discloses a modified hydroxyl acrylic emulsion and a preparation method thereof, and belongs to the technical field of environment-friendly paints.The modified hydroxyl acrylic emulsion is prepared from, by weight, 35-50 parts of acrylate monomer, 5-10 parts of functional monomer, 5-10 parts of hydroxyethyl acrylate, 0.3-1.5 parts of initiator, 1-2 parts of vinyl siloxane, 1-2 parts of emulsifier, 0.3-1 part of neutralizer and 30-50 parts of deionized water; the preparation method comprises the following steps: adding an acrylate monomer, a functional monomer, hydroxyethyl acrylate and vinyl siloxane into deionized water, adding an initiator and an emulsifier, heating to 60-75 DEG C, stirring at a constant speed for 30 minutes, and adding a neutralizer to prepare a modified hydroxyl acrylic emulsion; a functional monomer structure contains an antibacterial dichloropyrimidine monomer structure, a main body is an acrylic acid structure and has good compatibility with a matrix, a siloxane structure is introduced, a large number of hydroxyl groups are generated after hydrolysis, and the bonding performance with the coating matrix can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental protection coatings, and particularly relates to a modified hydroxyl acrylic emulsion and a preparation method thereof. Background Art

[0002] Traditional solvent-based polyurethane coatings have been widely used in the fields of automobiles, industry, heavy corrosion prevention, etc. due to their excellent comprehensive performance. In recent years, with the continuous improvement of people's environmental protection awareness and the increasingly strict restrictions of environmental protection regulations on volatile organic compounds (VOC / TVOC) and harmful air pollutants (HAPs), the development of low-VOC or VOC-free coatings has become an important task in the coating industry. For example, low-VOC coatings such as high-solids coatings, waterborne coatings, and solvent-free coatings (such as powder coatings, UV coatings) have become the forefront research directions in the coating industry. Waterborne two-component polyurethane coatings have become a type of replacement product for solvent-based systems. Since the early 1990s, Jacobs successfully developed a polyisocyanate curing agent that can be dispersed in water, thus enabling two-component waterborne polyurethane coatings to truly enter the stage of practical application research. Urethane coatings have become the mainstream products in the market.

[0003] The components of waterborne hydroxyl acrylic resins mainly include two types: hydroxyl acrylic dispersions and hydroxyl acrylic emulsions. Among them, hydroxyl acrylic dispersions are generally synthesized by phase inversion through solution polymerization. However, organic solvents are used in the synthesis process, which increases production costs and also pollutes the environment. Moreover, the synthesized dispersions generally have a relatively high viscosity, which is not conducive to uniform dispersion with isocyanate curing agents, and their hydroxyl content is relatively high, resulting in an increase in the usage amount of polyisocyanate curing agents, thereby increasing production and usage costs. Moreover, how to endow waterborne hydroxyl acrylic resins with antibacterial functions through monomer modification is still a technical problem that needs to be solved urgently. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a modified hydroxyl acrylic emulsion and a preparation method thereof.

[0005] The object of the present invention can be achieved by the following technical solutions: The modified hydroxyl acrylic emulsion comprises the following raw materials in parts by weight: 35 - 50 parts of acrylate monomers, 5 - 10 parts of functional monomers, 5 - 10 parts of hydroxyethyl acrylate, 0.3 - 1.5 parts of initiator, 1 - 2 parts of vinyl siloxane, 1 - 2 parts of emulsifier, 0.3 - 1 part of neutralizer, and 30 - 50 parts of deionized water; The functional monomer is prepared through the following steps: Step S1: Add 2-aminopyrimidine to glacial acetic acid, slowly introduce chlorine gas at 0 - 5°C, keep the temperature for reaction for 2 h, pour the reaction mixture into ice water after the reaction, filter and wash to obtain intermediate 1; In step S1, 2-aminopyrimidine reacts with chlorine gas, and a chlorine atom is introduced into the structure of 2-aminopyrimidine to obtain intermediate 1. Step S2: Add intermediate 1 into tetrahydrofuran, add dibutyltin dilaurate, introduce nitrogen gas, slowly add hexamethylene diisocyanate, heat up to 45 - 60 °C, keep the temperature for reaction for 4 h. After the reaction ends, add 2-hydroxyethyl methacrylate and hydroquinone, and continue to keep the temperature for reaction for 4 - 6 h. After the reaction ends, intermediate 2 is obtained. In step S2, the amino group on intermediate 1 reacts with the isocyanate group on hexamethylene diisocyanate. Then, 2-hydroxyethyl methacrylate is added, and the remaining isocyanate group reacts with the hydroxyl group on 2-hydroxyethyl methacrylate, thereby preparing intermediate 2. This intermediate 2 is a monomer structure containing antibacterial dichloropyrimidine, and its main body is an acrylic acid structure, which has good compatibility with the matrix.

[0006] Furthermore, in step S1, control the dosage ratio of 2-aminopyrimidine, chlorine gas and glacial acetic acid to be 1 - 2 mmol : 1 - 2 mmol : 3 - 5 mL.

[0007] Furthermore, in step S2, control the dosage ratio of intermediate 1, hexamethylene diisocyanate, 2-hydroxyethyl methacrylate, hydroquinone, dibutyltin dilaurate and tetrahydrofuran to be 1 - 2 mmol : 1 - 1.5 mmol : 1 - 1.5 mmol : 0.01 mmol : 0.05 - 0.08 mmol : 50 mL.

[0008] Furthermore, the initiator is composed of one or more of sodium sulfate, potassium persulfate and ammonium persulfate mixed in any proportion.

[0009] Furthermore, the emulsifier is composed of one or more of sodium dodecyl sulfate, triethanolamine stearate and alkylphenol polyoxyethylene ether mixed in any proportion.

[0010] Furthermore, the neutralizing agent is ammonia water.

[0011] A preparation method of a modified hydroxyacrylic emulsion includes the following steps: Add acrylate monomer, functional monomer, 2-hydroxyethyl acrylate and vinyl siloxane into deionized water, add an initiator and an emulsifier, heat up to 60 - 75 °C, stir evenly for 30 min, add a neutralizing agent to obtain a modified hydroxyacrylic emulsion.

[0012] Advantages of the present invention: The present invention prepares a modified hydroxyacrylic emulsion. Through the synthesized functional monomer, the emulsion can be given excellent antibacterial properties. Among them, in the synthesis process of the functional monomer, 2-aminopyrimidine reacts with chlorine gas first, and a chlorine atom is introduced into the 2-aminopyrimidine structure to obtain intermediate 1. Then, the amino group on intermediate 1 reacts with the isocyanate group on hexamethylene diisocyanate. After that, hydroxyethyl methacrylate is added, and the remaining isocyanate group reacts with the hydroxyl group on hydroxyethyl methacrylate, thereby preparing intermediate 2. This intermediate 2 is a monomer structure containing antibacterial dichloropyrimidine, and the main body is an acrylic acid structure, which has good compatibility with the matrix. Moreover, a siloxane structure is introduced, and a large number of hydroxyl groups are generated after hydrolysis, which can improve the bonding performance with the coating matrix. Detailed implementation mode

[0013] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

[0014] Example 1: A modified hydroxyacrylic emulsion, comprising the following raw materials in parts by weight: 35 parts of acrylate monomer, 5 parts of functional monomer, 5 parts of hydroxyethyl acrylate, 0.3 part of initiator, 1 part of vinyl siloxane, 1 part of emulsifier, 0.3 part of neutralizer, and 30 parts of deionized water; A preparation method of a modified hydroxyacrylic emulsion, comprising the following steps: Add the acrylate monomer, functional monomer, hydroxyethyl acrylate, and vinyl siloxane to deionized water, add the initiator and emulsifier, heat up to 60 °C, stir evenly for 30 min, and add the neutralizer to obtain a modified hydroxyacrylic emulsion.

[0015] The functional monomer is prepared through the following steps: Step S1: Add 2-aminopyrimidine to glacial acetic acid, slowly introduce chlorine gas at 0 °C, keep the temperature for reaction for 2 h, pour the reaction mixture into ice water after the reaction, filter and wash to obtain intermediate 1; Step S2: Add intermediate 1 to tetrahydrofuran, add dibutyltin dilaurate, introduce nitrogen gas, slowly add hexamethylene diisocyanate, heat up to 45 °C, keep the temperature for reaction for 4 h, add hydroxyethyl methacrylate and hydroquinone after the reaction, and continue to keep the temperature for reaction for 4 h to obtain intermediate 2 after the reaction; In step S1, the dosage ratio of 2-aminopyrimidine, chlorine gas, and glacial acetic acid is controlled to be 1 mmol: 1 mmol: 3 mL.

[0016] In step S2, the dosage ratios of intermediate 1, hexamethylene diisocyanate, 2-hydroxyethyl methacrylate, hydroquinone, dibutyltin dilaurate and tetrahydrofuran are controlled to be 1 mmol: 1 mmol: 1 mmol: 0.01 mmol: 0.05 mmol: 50 mL.

[0017] The initiator is sodium sulfate.

[0018] The emulsifier is sodium dodecyl sulfate.

[0019] The neutralizer is ammonia water.

[0020] Example 2: Modified hydroxyacrylic emulsion, comprising the following raw materials in parts by weight: 40 parts of acrylate monomer, 6 parts of functional monomer, 6 parts of 2-hydroxyethyl acrylate, 0.8 part of initiator, 1.2 parts of vinyl siloxane, 1.2 parts of emulsifier, 0.5 part of neutralizer, 40 parts of deionized water; A preparation method of the modified hydroxyacrylic emulsion comprises the following steps: Add the acrylate monomer, functional monomer, 2-hydroxyethyl acrylate and vinyl siloxane into deionized water, add the initiator and emulsifier, heat up to 65 °C, stir evenly for 30 min, add the neutralizer, and obtain the modified hydroxyacrylic emulsion.

[0021] The functional monomer is prepared through the following steps: Step S1: Add 2-aminopyrimidine into glacial acetic acid, slowly introduce chlorine gas at 2 °C, keep the temperature for reaction for 2 h, pour into ice water after the reaction ends, filter and wash to obtain intermediate 1; Step S2: Add intermediate 1 into tetrahydrofuran, add dibutyltin dilaurate, introduce nitrogen gas, slowly add hexamethylene diisocyanate, heat up to 50 °C, keep the temperature for reaction for 4 h, add 2-hydroxyethyl methacrylate and hydroquinone after the reaction ends, and continue to keep the temperature for reaction for 5 h to obtain intermediate 2 after the reaction ends; In step S1, the dosage ratios of 2-aminopyrimidine, chlorine gas and glacial acetic acid are controlled to be 1.5 mmol: 1.5 mmol: 3 mL.

[0022] In step S2, the dosage ratios of intermediate 1, hexamethylene diisocyanate, 2-hydroxyethyl methacrylate, hydroquinone, dibutyltin dilaurate and tetrahydrofuran are controlled to be 1.5 mmol: 1.4 mmol: 1.4 mmol: 0.01 mmol: 0.08 mmol: 50 mL.

[0023] The initiator is potassium persulfate.

[0024] The emulsifier is triethanolamine stearate.

[0025] The neutralizer is ammonia water.

[0026] Example 3: Modified hydroxy acrylic emulsion, comprising the following raw materials in parts by weight: 45 parts of acrylate monomer, 8 parts of functional monomer, 8 parts of hydroxyethyl acrylate, 1.2 parts of initiator, 1.5 parts of vinyl siloxane, 1.8 parts of emulsifier, 0.8 part of neutralizer, and 50 parts of deionized water; Preparation method of modified hydroxy acrylic emulsion, comprising the following steps: Add acrylate monomer, functional monomer, hydroxyethyl acrylate and vinyl siloxane into deionized water, add initiator and emulsifier, heat up to 75 °C, stir evenly for 30 min, add neutralizer to obtain modified hydroxy acrylic emulsion.

[0027] The functional monomer is prepared by the following steps: Step S1: Add 2-aminopyrimidine into glacial acetic acid, slowly introduce chlorine gas at 5 °C, keep the temperature for reaction for 2 h, pour into ice water after the reaction, filter and wash to obtain intermediate 1; Step S2: Add intermediate 1 into tetrahydrofuran, add dibutyltin dilaurate, introduce nitrogen gas, slowly add hexamethylene diisocyanate, heat up to 60 °C, keep the temperature for reaction for 4 h, add hydroxyethyl methacrylate and hydroquinone after the reaction, continue to keep the temperature for reaction for 6 h, and obtain intermediate 2 after the reaction; In step S1, control the dosage ratio of 2-aminopyrimidine, chlorine gas and glacial acetic acid to be 2 mmol: 2 mmol: 5 mL.

[0028] In step S2, control the dosage ratio of intermediate 1, hexamethylene diisocyanate, hydroxyethyl methacrylate, hydroquinone, dibutyltin dilaurate and tetrahydrofuran to be 2 mmol: 1.2 mmol: 1.5 mmol: 0.01 mmol: 0.08 mmol: 50 mL.

[0029] The initiator is ammonium persulfate.

[0030] The emulsifier is alkylphenol polyoxyethylene ether.

[0031] The neutralizer is ammonia water.

[0032] Example 4: Modified hydroxy acrylic emulsion, comprising the following raw materials in parts by weight: 50 parts of acrylate monomer, 10 parts of functional monomer, 10 parts of hydroxyethyl acrylate, 1.5 parts of initiator, 2 parts of vinyl siloxane, 2 parts of emulsifier, 1 part of neutralizer, and 50 parts of deionized water; Preparation method of modified hydroxy acrylic emulsion, comprising the following steps: Add acrylate monomer, functional monomer, hydroxyethyl acrylate and vinyl siloxane into deionized water, add initiator and emulsifier, heat up to 75 °C, stir evenly for 30 min, add neutralizer to obtain modified hydroxy acrylic emulsion.

[0033] The functional monomer is prepared through the following steps: Step S1: Add 2-aminopyrimidine into glacial acetic acid, slowly introduce chlorine gas at 5°C, keep the temperature for reaction for 2 h, pour the reaction mixture into ice water after the reaction, filter and wash to obtain intermediate 1; Step S2: Add intermediate 1 into tetrahydrofuran, add dibutyltin dilaurate, introduce nitrogen gas, slowly add hexamethylene diisocyanate, raise the temperature to 60°C, keep the temperature for reaction for 4 h, add 2-hydroxyethyl methacrylate and hydroquinone after the reaction, continue to keep the temperature for reaction for 6 h, and obtain intermediate 2 after the reaction; In step S1, the dosage ratio of 2-aminopyrimidine, chlorine gas and glacial acetic acid is controlled to be 2 mmol: 2 mmol: 5 mL.

[0034] In step S2, the dosage ratio of intermediate 1, hexamethylene diisocyanate, 2-hydroxyethyl methacrylate, hydroquinone, dibutyltin dilaurate and tetrahydrofuran is controlled to be 2 mmol: 1.5 mmol: 1.5 mmol: 0.01 mmol: 0.08 mmol: 50 mL.

[0035] The initiator is sodium sulfate.

[0036] The emulsifier is triethanolamine stearate.

[0037] The neutralizer is ammonia water.

[0038] Comparative example 1: Compared with Example 1, 2-hydroxyethyl acrylate is used to replace the modified monomer of the present invention, and the rest is the same as in Example 1.

[0039] The emulsions prepared in Examples 1-4 and Comparative Example 1 are made into coatings, and then the properties of the coatings are tested. The results are shown in Table 1 below: The coating formulation is as follows: 100 g of the emulsion prepared in Examples 1-4, 0.2 g of a leveling and wetting agent (Degussa TEGORad 2100), 0.1 g of an antifoaming agent (TEGO810), 3 g of gelatin, and 10 parts of a curing agent (polyisocyanate AQ-130).

[0040] Coating preparation method: Mix the emulsion, leveling and wetting agent, antifoaming agent and gelatin evenly, and then add the curing agent for curing.

[0041]

[0042] It can be seen from Table 1 above that the coatings prepared in Examples 1-4 of the present invention have excellent adhesion and excellent antibacterial properties, indicating that the functional monomer contains a monomer structure of antibacterial dichloropyrimidine, and the main body is an acrylic structure, which has good compatibility with the substrate. Moreover, a siloxane structure is introduced, and a large number of hydroxyl groups are generated after hydrolysis, which can improve the bonding performance with the coating substrate.

[0043] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of the present technology can make various modifications or supplements to the described specific embodiments or use similar methods for substitution, as long as they do not deviate from the concept of the invention or exceed the scope defined by this claim book, they should all fall within the protection scope of the present invention.

Claims

1. Modified hydroxyl acrylic emulsion, characterized in that, The method comprises the following raw materials in parts by weight: 35-50 parts of acrylate monomer, 5-10 parts of functional monomer, 5-10 parts of hydroxyethyl acrylate, 0.3-1.5 parts of initiator, 1-2 parts of vinyl siloxane, 1-2 parts of emulsifier, 0.3-1 parts of neutralizer, and 30-50 parts of deionized water; The functional monomer is prepared by the following steps: Step S1, adding 2-aminopyrimidine to glacial acetic acid, slowly introducing chlorine gas at 0-5°C, and keeping the temperature for reaction for 2h. After the reaction is completed, pouring into ice water, filtering and washing to obtain intermediate 1; Step S2, adding intermediate 1 to tetrahydrofuran, adding dibutyltin dilaurate, passing nitrogen, slowly adding hexamethylene diisocyanate, raising the temperature to 45-60° C., keeping the temperature for reaction for 4 hours, adding hydroxyethyl methacrylate and hydroquinone after the reaction is completed, and continuing to keep the temperature for reaction for 4-6 hours. After the reaction is completed, intermediate 2 is obtained.

2. The modified hydroxyl acrylic emulsion according to claim 1, characterized in that In step S1, the dosage ratio of 2-aminopyrimidine, chlorine gas and glacial acetic acid is controlled to be 1-2 mmol: 1-2 mmol: 3-5 mL.

3. The modified hydroxyl acrylic emulsion according to claim 1, characterized in that In step S2, the dosage ratio of intermediate 1, hexamethylene diisocyanate, hydroxyethyl methacrylate, hydroquinone, dibutyltin dilaurate and tetrahydrofuran is controlled to be 1-2 mmol: 1-1.5 mmol: 1-1.5 mmol: 0.01 mmol: 0.05-0.08 mmol: 50 mL.

4. The modified hydroxyl acrylic emulsion according to claim 1, characterized in that The initiator is a mixture of one or more of sodium sulfate, potassium persulfate and ammonium persulfate in any proportion.

5. The modified hydroxyl acrylic emulsion according to claim 1, characterized in that: The emulsifier is a mixture of one or more of sodium lauryl sulfate, triethanolamine stearate and alkylphenol polyoxyethylene ether in any proportion.

6. The modified hydroxyl acrylic emulsion according to claim 1, characterized in that: The neutralizing agent is aqueous ammonia.

7. The method for preparing the modified hydroxyl acrylic emulsion according to claim 1, characterized in that: The steps include: Add acrylate monomer, functional monomer, hydroxyethyl acrylate, and vinyl siloxane into deionized water, add initiator and emulsifier, raise the temperature to 60-75° C., stir at a constant speed for 30 minutes, add neutralizer, and prepare modified hydroxy acrylic emulsion.

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