Water-based acrylic emulsion as well as preparation method and application thereof

Abstract

The invention belongs to the field of environment-friendly adhesives, and particularly discloses a water-based acrylic emulsion as well as a preparation method and application thereof. The emulsion is prepared by taking butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate and vinyl acetate as main raw materials through an emulsion polymerization process. In the preparation process, parameters such as the ratio of the raw materials, the polymerization temperature and the stirring speed are optimized, so that the stable performance of the emulsion is ensured; besides, in order to improve the strength and water resistance of the emulsion, a proper amount of epoxy resin is added in the later compounding process, and the addition of the epoxy resin not only enhances the adhesive strength of the emulsion, but also improves the water resistance and weather resistance of the emulsion, so that the emulsion can still keep good performance in severe environments such as high temperature and high humidity.

Description

Technical Field

[0001] The invention belongs to the field of environmentally friendly adhesives and specifically discloses a water-based acrylic emulsion and a preparation method and application thereof. Background Art

[0002] Polyurethane adhesives are widely used in many industries, but the toxic substances and solvent volatilization involved in their production process pose a potential threat to the environment and human health. Therefore, it is particularly urgent to develop an alternative product that is both environmentally friendly and has superior performance. As an environmentally friendly adhesive, water-based acrylic emulsion has gradually become a research hotspot due to its non-toxic, odorless, and good water resistance.

[0003] Water-based acrylic emulsion adhesives mainly consist of monomers, emulsifiers, and initiators. Monomers are the most important components in the emulsion polymerization system. The type and amount of monomers determine the physical and mechanical properties, chemical properties, bonding properties, and construction properties of the emulsion polymer. For a specific use of the polymer emulsion, it is crucial to choose the monomers reasonably. The monomers of acrylic copolymer emulsions are generally (meth) acrylic acid and (meth) alkyl (C 1-C 8) esters, which can be divided into three categories: soft monomers, hard monomers, and functional monomers; emulsifiers are one of the main components in the emulsion polymerization system, which has an important influence on the emulsion polymerization process and the final stability of the product. According to the different properties of the hydrophilic groups in the emulsifier molecules, emulsifiers can be divided into four categories, namely anionic emulsifiers (such as sodium dodecyl sulfate SDS, sodium dodecylbenzene sulfonate SDBS, etc.), cationic emulsifiers, nonionic emulsifiers, and amphoteric emulsifiers. The type and amount of initiator will directly affect the output and quality of the product, and affect the polymerization reaction rate, particle size, and molecular weight. Initiators for emulsion polymerization are divided into two categories: thermal decomposition initiators and redox initiators.

[0004] However, the existing water-based acrylic emulsion adhesives have shortcomings such as low bonding strength, low viscosity, and poor water and weather resistance, and there is still a need to continue to modify their formulation composition and preparation method. Summary of the invention

[0005] Based on the deficiencies in the prior art, the present invention discloses a water-based acrylic emulsion and a preparation method and application thereof.

[0006] The present invention includes the following technical solutions:

[0007] A water-based acrylic emulsion, calculated by weight, is made from the following raw materials:

[0008]

[0009]

[0010] Preferably, the above-mentioned aqueous acrylic emulsion is made of the following raw materials, calculated by weight:

[0011] Preferably, the above-mentioned aqueous acrylic emulsion is made of the following raw materials, calculated by weight:

[0012] Preferably, the above-mentioned aqueous acrylic emulsion is made of the following raw materials, calculated by weight:

[0013]

[0014]

[0015] Furthermore, the present invention discloses a method for preparing the above-mentioned water-based acrylic emulsion, comprising the following steps: adding a formula amount of butyl acrylate, isooctyl acrylate, methyl methacrylate, vinyl acetate, purified water, and an emulsifier into a reactor, stirring evenly, controlling the stirring speed to 60-80 revolutions per minute, controlling the temperature of the reactor to 70-75° C., dripping in a pre-prepared aqueous solution of ammonium persulfate, dripping in 3-4 hours, keeping warm for 1-2 hours, cooling to 30-40° C., adding a formula amount of epoxy resin and a coupling agent, stirring evenly, and barreling after sampling and passing the test.

[0016] Furthermore, in the method for preparing the above-mentioned aqueous acrylic emulsion, the stirring speed is 60 revolutions per minute, 70 revolutions per minute or 80 revolutions per minute.

[0017] Furthermore, in the method for preparing the aqueous acrylic emulsion, the dropping time is 3 hours, 3.5 hours or 4 hours.

[0018] Furthermore, in the method for preparing the above-mentioned aqueous acrylic emulsion, the heat preservation time is 1 hour, 1.5 hours or 2 hours.

[0019] Furthermore, in the method for preparing the above aqueous acrylic emulsion, the cooling temperature is 30°C, 35°C or 40°C.

[0020] The invention also discloses the use of the aqueous acrylic emulsion in preparing an adhesive for magnesium oxysulfide insulation boards or glass magnesium boards.

[0021] Compared with the prior art, the present invention has the following outstanding beneficial effects:

[0022] The present invention provides a water-based acrylic emulsion, which is intended to replace traditional polyurethane adhesives. The emulsion is prepared by an emulsion polymerization process with butyl acrylate, isooctyl acrylate, methyl methacrylate and vinyl acetate as main raw materials. During the preparation process, the parameters such as the ratio of raw materials, polymerization temperature, stirring speed, etc. are optimized to ensure the stable performance of the emulsion. In addition, in order to improve the strength and water resistance of the emulsion, the present invention adds an appropriate amount of epoxy resin in the later compounding process. The addition of epoxy resin not only enhances the adhesion of the emulsion, but also improves its water resistance and weather resistance, so that it can still maintain good performance under harsh environments such as high temperature and high humidity, and the water-based acrylic emulsion of the present invention has no toxic substance release during production and use, and is environmentally friendly. Through the implementation of the present invention, polyurethane adhesives can be effectively replaced, and an environmentally friendly and high-performance adhesive solution can be provided for multiple industries.

[0023] On the other hand, magnesium oxysulfide insulation board has the characteristics of low thermal conductivity, non-flammability, high strength, and no pollution, and has a tendency to gradually replace rock wool and EPS board in the sandwich color steel plate industry. It is an urgent need to find an adhesive suitable for bonding magnesium oxysulfide board. The present invention uses epoxy resin to modify water-based acrylic emulsion and adds a titanate coupling agent. Due to the cross-linking effect of the coupling agent, the bonding strength of the adhesive is greatly enhanced, which is very suitable for the production and preparation of magnesium oxysulfide insulation board. DETAILED DESCRIPTION

[0024] 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 them. 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.

[0025] Example 1

[0026] Add 15 parts of butyl acrylate, 30 parts of isooctyl acrylate, 15 parts of methyl methacrylate, 8 parts of vinyl acetate, 45 parts of purified water, and 0.5 parts of emulsifier alkylphenol polyoxyethylene ether OP-10 into the reactor, stir evenly, control the stirring speed at 60 revolutions per minute, control the temperature of the reactor at 70-75°C, drip in a pre-prepared aqueous solution of ammonium persulfate (5 parts of purified water, 0.2 parts of ammonium persulfate), drip completely within 3 hours, keep warm for 2 hours, cool to 30°C, add 8 parts of epoxy resin E-51 and 0.5 parts of titanate coupling agent 401, stir evenly, take samples and put them into barrels after passing the test.

[0027] Example 2

[0028] Add 5 parts of butyl acrylate, 20 parts of isooctyl acrylate, 5 parts of methyl methacrylate, 5 parts of vinyl acetate, 40 parts of pure water, and 0.2 parts of emulsifier alkylphenol polyoxyethylene ether OP-10 into the reactor, stir evenly, control the stirring speed to 80 revolutions per minute, control the temperature of the reactor to 70-75°C, drip in the pre-prepared ammonium persulfate aqueous solution (5 parts of pure water, 0.1 parts of ammonium persulfate), drip it in 4 hours, keep warm for 1 hour, cool to 40°C, add 6 parts of epoxy resin E-51 and 1 part of titanate coupling agent 401, stir evenly, take samples and put them into barrels after passing the test.

[0029] Example 3

[0030] Add 10 parts of butyl acrylate, 25 parts of isooctyl acrylate, 10 parts of methyl methacrylate, 6.5 parts of vinyl acetate, 42.5 parts of pure water, and 0.4 parts of emulsifier alkylphenol polyoxyethylene ether OP-10 into the reactor, stir evenly, control the stirring speed to 70 revolutions per minute, control the temperature of the reactor to 70-75°C, drip in the pre-prepared ammonium persulfate aqueous solution (5 parts of pure water, 0.15 parts of ammonium persulfate), drip in, keep warm for 1.5 hours, cool to 35°C, add 7 parts of epoxy resin E-51, 0.75 parts of titanate coupling agent 401, stir evenly, take samples and put them into barrels after passing the test.

[0031] Comparative Example

[0032] Add 10 parts of butyl acrylate, 25 parts of isooctyl acrylate, 10 parts of methyl methacrylate, 6.5 parts of vinyl acetate, 42.5 parts of pure water, and 0.4 parts of emulsifier alkylphenol polyoxyethylene ether OP-10 into the reactor, stir evenly, control the stirring speed to 70 revolutions per minute, control the temperature of the reactor to 70-75°C, drip in the pre-prepared ammonium persulfate aqueous solution (5 parts of pure water, 0.15 parts of ammonium persulfate), drip completely in 3.5 hours, keep warm for 1.5 hours, cool to 35°C, take samples and put them into barrels after passing the test.

[0033] Test Case

[0034] This test example conducts comparative tests on the emulsions prepared in Example 2 and the comparative example, mainly testing the water absorption rate, pull-out strength and water resistance.

[0035] The test method is as follows:

[0036] Water absorption rate: scrape a thin layer of film of the emulsion on a glass slide, peel it off and dry it after the film is formed, immerse it in 25℃ water for 24 hours, take it out, absorb the water droplets on the surface and weigh it.

[0037] Water absorption rate = (wet film weight - dry film weight) / dry film weight × 100%

[0038] Pull-out strength: Take 2 pieces of magnesium oxysulfide material test pieces of 10cm*10cm*10cm, apply the emulsion evenly on one side and stick them together. After 24 hours, test the pull-out strength on a pull-out strength tester.

[0039] Water resistance: First test the pull-out strength of the dry product, then test the pull-out strength after immersion in water for 24 hours.

[0040] Water resistance = (dry product tensile strength - wet product tensile strength) / dry product tensile strength × 100%

[0041] The results are shown in Table 1

[0042] Table 1 Emulsion performance comparison test

[0043]

[0044] As can be seen from Table 1 above, compared with the comparative example, the present invention adds a titanate coupling agent on the basis of modifying the water-based acrylic emulsion with epoxy resin. Due to the cross-linking effect of the coupling agent, the bonding strength of the adhesive is greatly enhanced, which is very suitable for the production and preparation of magnesium oxysulfide insulation board. Through the implementation of the present invention, polyurethane adhesives can be effectively replaced, providing an environmentally friendly, high-performance adhesive solution for multiple industries.

[0045] The above are only a few preferred embodiments of the present invention, which are described in a more specific and detailed manner, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A water-based acrylic emulsion, It is characterized in that Calculated by weight, it is made from the following raw materials: Butyl acrylate 5-15 parts 20-30 parts of 2-ethylhexyl acrylate Methyl methacrylate 5-15 parts 5-8 parts of vinyl acetate 40-45 parts of purified water Emulsifier 0.3-0.5 parts Ammonium persulfate 0.1-0.2 parts Epoxy resin 6-8 parts Coupling agent 0.5-1 part.

2. A water-based acrylic emulsion according to claim 1, It is characterized in that Calculated by weight, it is made from the following raw materials: Butyl acrylate 15 parts 30 parts of 2-ethylhexyl acrylate 15 parts of methyl methacrylate 8 parts of vinyl acetate 45 parts of purified water Emulsifier 0.5 parts 0.2 parts of ammonium persulfate Epoxy resin 8 parts 0.5 parts of coupling agent.

3. A water-based acrylic emulsion according to claim 1, It is characterized in that Calculated by weight, it is made from the following raw materials: Butyl acrylate 5 parts 20 parts of 2-ethylhexyl acrylate 5 parts of methyl methacrylate 5 parts of vinyl acetate 40 parts of purified water Emulsifier 0.2 parts 0.1 part ammonium persulfate Epoxy resin 6 parts 1 part of coupling agent.

4. A water-based acrylic emulsion according to claim 1, It is characterized in that Calculated by weight, it is made from the following raw materials: Butyl acrylate 10 parts 25 parts of 2-ethylhexyl acrylate Methyl methacrylate 10 parts 6.5 parts of vinyl acetate 42.5 parts of purified water Emulsifier 0.4 parts 0.15 parts of ammonium persulfate Epoxy resin 7 parts 0.75 parts of coupling agent.

5. A method for preparing an aqueous acrylic emulsion according to any one of claims 1 to 4, It is characterized in that The method comprises the following steps: adding a formula amount of butyl acrylate, isooctyl acrylate, methyl methacrylate, vinyl acetate, purified water and an emulsifier into a reactor, stirring evenly, controlling the stirring speed at 60-80 revolutions per minute, controlling the temperature of the reactor at 70-75° C., dripping in a pre-configured aqueous solution of ammonium persulfate, dripping in 3-4 hours, keeping warm for 1-2 hours, cooling to 30-40° C., adding a formula amount of epoxy resin and a coupling agent, stirring evenly, taking samples and barreling after they are qualified.

6. The preparation method according to claim 5, It is characterized in that The stirring speed is 60 rpm, 70 rpm or 80 rpm.

7. The preparation method according to claim 5, It is characterized in that The dropping time is 3 hours, 3.5 hours or 4 hours.

8. The preparation method according to claim 5, It is characterized in that The insulation time is 1 hour, 1.5 hours or 2 hours.

9. The preparation method according to claim 5, It is characterized in that The cooling temperature is 30°C, 35℃ or 40℃.

10. Use of the aqueous acrylic emulsion according to any one of claims 1 to 4 in the preparation of an adhesive for magnesium oxysulfide insulation board or glass magnesium board.

Images