阅读说明：本技术 一种双组分乳液及其制备方法 (Bi-component emulsion and preparation method thereof ) 是由 么文新 于 2020-06-04 设计创作，主要内容包括：本发明提出一种双组分乳液及其制备方法,包括组分A和组分B；组分A制备方法为：将聚乙烯醇和过硫酸钾加入水中制得第一溶液,将过硫酸钾加入水中制得第二溶液,之后将第二溶液、甲基丙烯酸、苯乙烯加入第一溶液中聚合；向上述产物中加入甲基丙烯酸、甲基丙烯酸甲酯、丙烯酸异辛酯、甲基丙烯酸异辛酯、乙酰乙酸基甲基丙烯酸乙酯、乙烯-醋酸乙烯共聚物(添加之前先用β射线进行预辐照)和过硫酸钾,搅拌下在80-90℃下聚合；组分B制备方法为：将醋酸锌、氨水、聚乙烯醇和水混合后搅拌均匀；以上原料均以重量份计。该双组分乳液分开储存、使用时按比例混合,既可以兼顾成膜的柔韧性和强度,又有助于提高生产效率。(The invention provides a bi-component emulsion and a preparation method thereof, comprising a component A and a component B; the preparation method of the component A comprises the following steps: adding polyvinyl alcohol and potassium persulfate into water to prepare a first solution, adding potassium persulfate into water to prepare a second solution, and then adding the second solution, methacrylic acid and styrene into the first solution for polymerization; adding methacrylic acid, methyl methacrylate, isooctyl acrylate, isooctyl methacrylate, acetoacetoxy ethyl methacrylate, ethylene-vinyl acetate copolymer (pre-irradiation with beta rays before addition) and potassium persulfate into the product, and polymerizing at 80-90 ℃ under stirring; the preparation method of the component B comprises the following steps: mixing zinc acetate, ammonia water, polyvinyl alcohol and water, and stirring uniformly; the raw materials are calculated by weight portion. The bi-component emulsion is stored separately and mixed in proportion when in use, thereby not only taking account of the flexibility and the strength of the film formation, but also being beneficial to improving the production efficiency.)

1. A method for preparing a two-component emulsion, comprising: the special two-component emulsion for producing the soft stone comprises a component A and a component B;

the component A is prepared by the following process steps:

the method comprises the following steps: adding 1-3 parts of water-soluble polyvinyl alcohol and 0.01-0.05 part of potassium persulfate into 10-20 parts of distilled water, stirring at 80-85 ℃ for at least 10min to prepare a first solution, adding 0.02-0.08 part of potassium persulfate into 0.5-1 part of distilled water, uniformly stirring to prepare a second solution, then adding 0.3-0.8 part of methacrylic acid and 0.1-0.5 part of styrene into the first solution, and carrying out polymerization reaction for at least 30min under stirring;

step two: adding 0.5-2 parts of methacrylic acid, 1-3 parts of methyl methacrylate, 2-5 parts of isooctyl acrylate, 0.5-4 parts of isooctyl methacrylate, 0.1-0.5 part of acetoacetoxy ethyl methacrylate, 1.8-3.5 parts of ethylene-vinyl acetate copolymer and 0.1-0.2 part of potassium persulfate into the product obtained in the previous step, and continuing the polymerization reaction for at least 30min at 85-88 ℃ under stirring, wherein the ethylene-vinyl acetate copolymer is pre-irradiated by beta rays in an air atmosphere by using an electron accelerator before the addition in the second step, the pre-irradiation dose is 20-30kGy, and the pre-irradiation time is 5-15 min;

the preparation method of the component B comprises the following steps: mixing 0.5-5 parts of zinc acetate, 0.5-3 parts of ammonia water, 0.1-1 part of water-soluble polyvinyl alcohol and 60-100 parts of distilled water, and uniformly stirring, wherein the concentration of the ammonia water is 25%;

the raw materials are calculated by weight portion.

2. The method for preparing a two-component emulsion according to claim 1, characterized in that: the component A is prepared by the following process steps:

the method comprises the following steps: adding 1.8 parts of water-soluble polyvinyl alcohol and 0.025 part of potassium persulfate into 14 parts of distilled water, stirring at 80-85 ℃ for at least 10min to prepare a first solution, adding 0.05 part of potassium persulfate into 0.6 part of distilled water, uniformly stirring to prepare a second solution, then adding the second solution, 0.5 part of methacrylic acid and 0.3 part of styrene into the first solution, and carrying out polymerization reaction for at least 30min under stirring;

step two: adding 1 part of methacrylic acid, 2 parts of methyl methacrylate, 3.9 parts of isooctyl acrylate, 1.9 parts of isooctyl methacrylate, 0.3 part of acetoacetoxy ethyl methacrylate, 2.5 parts of ethylene-vinyl acetate copolymer and 0.125 part of potassium persulfate into the product obtained in the previous step, and continuously carrying out polymerization reaction for at least 30min at 85-88 ℃ under stirring;

the preparation method of the component B comprises the following steps: 2 parts of zinc acetate, 1.2 parts of ammonia water, 0.5 part of water-soluble polyvinyl alcohol and 81 parts of distilled water are mixed and stirred uniformly, and the concentration of the ammonia water is 25%;

the raw materials are calculated by weight portion.

3. The method for preparing a two-component emulsion according to claim 1, characterized in that: the component A also comprises 1.2 to 3.5 weight portions of nano talcum powder and 0.5 to 3.2 weight portions of plant fiber.

4. A method of preparing a two-component emulsion according to claim 3, characterized in that: the plant fiber is modified plant fiber grafted with acrylate, the nano talcum powder is added into the product obtained after the reaction in the step two and is uniformly stirred, and the plant fiber is added into the product obtained after the reaction in the step one and is uniformly stirred.

5. The method for preparing a two-component emulsion according to claim 1, characterized in that: the ethylene-vinyl acetate copolymer is 20-25% of vinyl acetate by mass percent, and the water-soluble polyvinyl alcohol is polyvinyl alcohol 1788.

6. A two-component emulsion obtained by the production method according to any one of claims 1 to 5.

Technical Field

The invention relates to the technical field of building materials, in particular to a bi-component emulsion and a preparation method thereof.

Background

In the preparation of building materials such as stone-like paint, soft stone and the like, the film-forming emulsion is often used. For example, chinese patent application No. 200910192563.4 discloses a pure acrylic emulsion of stone paint, which comprises the following components: nuclear monomer: 5-20% of methyl methacrylate, 5-20% of isooctyl acrylate, 5-10% of butyl acrylate and 1-5% of high-density crosslinking monomer; shell monomer: 5-20% of methyl methacrylate, 5-10% of isooctyl acrylate, 5-10% of butyl acrylate and 1-3% of acrylic acid; 1-5% of polymerizable emulsifier; 1-3% of persulfate; 50% of water. The chinese patent application No. 201510718824.7 discloses a silicon composite water-based acrylic emulsion, which comprises water, butyl acrylate, functional monomer, emulsifier and initiator, wherein the above components are converted into mass percentages respectively: 60% of water, 5-10% of butyl acrylate, 10-20% of methyl methacrylate, 3-8% of isooctyl acrylate, 10-15% of functional monomer, 1-3% of emulsifier and 0.1-0.5% of initiator. However, when these emulsions are used as film-forming materials, the film-forming time is long, and natural drying is generally required for at least 24 hours, so that a large amount of space is required; if heated for drying, the surface may be swollen, uneven and the resulting product may have poor flexibility. The drying time and the performance of the final product required by the production of building materials such as stone-like paint, soft stone and the like are closely related to the emulsion adopted in the preparation of the building materials, so that the improvement of the emulsion is urgently needed, the drying time required by film forming is shortened, the drying space is reduced and the production efficiency is improved on the basis of taking the flexibility and the strength into consideration.

Disclosure of Invention

In order to solve the defects of the prior art, the invention provides a bi-component emulsion and a preparation method thereof.

The technical scheme of the invention is realized as follows:

a preparation method of a bi-component emulsion comprises a component A and a component B;

the component A is prepared by the following process steps:

the method comprises the following steps: adding 1-3 parts of water-soluble polyvinyl alcohol and 0.01-0.05 part of potassium persulfate into 10-20 parts of distilled water, stirring at 80-85 ℃ for at least 10min to prepare a first solution, adding 0.02-0.08 part of potassium persulfate into 0.5-1 part of distilled water, uniformly stirring to prepare a second solution, then adding 0.3-0.8 part of methacrylic acid and 0.1-0.5 part of styrene into the first solution, and carrying out polymerization reaction for at least 30min under stirring to prepare a styrene-acrylic copolymer core emulsion;

step two: adding 0.5-2 parts of methacrylic acid, 1-3 parts of methyl methacrylate, 2-5 parts of isooctyl acrylate, 0.5-4 parts of isooctyl methacrylate, 0.1-0.5 part of acetoacetoxy ethyl methacrylate, 1.8-3.5 parts of ethylene-vinyl acetate copolymer and 0.1-0.2 part of potassium persulfate into the product obtained in the previous step, continuing polymerization reaction at 85-88 ℃ for at least 30min under stirring to obtain core-shell acrylic acid ionomer emulsion, and pre-irradiating the ethylene-vinyl acetate copolymer by using beta rays in an air atmosphere by using an electron accelerator before adding in the second step, wherein the pre-irradiation dose is 20-30kGy, and the pre-irradiation time is 5-15 min;

the preparation method of the component B comprises the following steps: mixing 0.5-5 parts of zinc acetate, 0.5-3 parts of ammonia water, 0.1-1 part of water-soluble polyvinyl alcohol and 60-100 parts of distilled water, and uniformly stirring to obtain a zinc-ammonia composite solution, wherein the concentration of the ammonia water is 25%;

the raw materials are calculated by weight portion.

Methyl methacrylate and styrene are hard monomers, so that the hardness and the water resistance can be improved; isooctyl acrylate and isooctyl methacrylate are soft monomers, and weather resistance and flexibility can be improved; acetoacetoxy ethyl methacrylate is a functional crosslinking monomer, and a crosslinking point is introduced to improve the adhesive force; the ethylene-vinyl acetate copolymer has the advantages that due to the introduction of ethylene molecular chains into polyvinyl acetate molecules, acetyl groups generate discontinuity, the rotational freedom degree of a high molecular chain is increased, the space obstruction is small, the high molecular main chain becomes soft, and the plasticizer migration cannot occur, so that the adhesive property is provided, the permanent flexibility is realized, the permanent softness of the product is ensured, and the ethylene-vinyl acetate copolymer has better resistance to the ethylene molecular chainsAcid-base, UV-aging resistance, and also after film formation, is an elastomer material. When the component A is prepared, firstly, styrene and methacrylic acid are used for preparing a core monomer, then methacrylic acid, methyl methacrylate, isooctyl acrylate, isooctyl methacrylate, acetoacetoxy ethyl methacrylate and an ethylene-vinyl acetate copolymer are used as shell monomers, the shell-core acrylic acid ionomer emulsion is obtained by copolymerization under the action of an initiator potassium persulfate, a soft monomer and a hard monomer are polymerized in a proper proportion, a functional monomer of acetoacetoxy ethyl methacrylate is added to introduce a crosslinking point and improve the adhesive force, and an ethylene-vinyl acetate copolymer is introduced at the same time, the ethylene-vinyl acetate copolymer not only has viscosity and permanent flexibility and can improve the flexibility after film forming, but also generates macromolecular peroxide after pre-irradiation, and can be used as an initiator in the polymerization reaction, so that the acrylic ester is grafted with partial monomers in the acrylic ester, and the grafted product can obviously improve the toughness, elasticity and impact resistance of the emulsion after being cured; the component B is stirred evenly to generate a zinc tetraammine complex [ Zn (NH) which can exist stably for a long time₃)₄]²⁺The method overcomes the defects that the zinc ammonia solution prepared by zinc oxide in the prior art is easy to have powder-shaped bottom precipitation and coking in the reaction process and causes unstable and uneven reaction and poor later storage stability in the emulsion preparation process. The component A and the component B are separately stored and mixed for use, and the zinc ion crosslinked core-shell acrylic acid ionomer emulsion is generated after mixing, can be used as a film-forming emulsion in building materials, and is suitable for the preparation of flexible coatings such as flexible real stone paint, flexible stone and the like or flexible building materials.

Preferably, component a is prepared by the following process steps:

the method comprises the following steps: adding 1.8 parts of water-soluble polyvinyl alcohol and 0.025 part of potassium persulfate into 14 parts of distilled water, stirring at 80-85 ℃ for at least 10min to prepare a first solution, adding 0.05 part of potassium persulfate into 0.6 part of distilled water, uniformly stirring to prepare a second solution, then adding the second solution, 0.5 part of methacrylic acid and 0.3 part of styrene into the first solution, and carrying out polymerization reaction for at least 30min under stirring to prepare a styrene-acrylic copolymer nuclear emulsion;

step two: adding 1 part of methacrylic acid, 2 parts of methyl methacrylate, 3.9 parts of isooctyl acrylate, 1.9 parts of isooctyl methacrylate, 0.3 part of acetoacetoxy ethyl methacrylate, 2.5 parts of ethylene-vinyl acetate copolymer and 0.125 part of potassium persulfate into the product obtained in the previous step, and continuously carrying out polymerization reaction for at least 30min at 85-88 ℃ under stirring to obtain a core-shell acrylic acid ionomer emulsion, wherein the ethylene-vinyl acetate copolymer is pre-irradiated by beta rays in an air atmosphere by using an electron accelerator before the addition in the second step, the pre-irradiation dose is 20-30kGy, and the pre-irradiation time is 5-15 min;

the preparation method of the component B comprises the following steps: mixing 2 parts of zinc acetate, 1.2 parts of ammonia water, 0.5 part of water-soluble polyvinyl alcohol and 81 parts of distilled water, and uniformly stirring to obtain a zinc-ammonia composite solution, wherein the concentration of the ammonia water is 25%;

the raw materials are calculated by weight portion.

Further preferably, the component A also comprises 1.2 to 3.5 weight parts of nano talcum powder and 0.5 to 3.2 weight parts of plant fiber. The addition of the nano talcum powder and the plant fiber can lead the components to generate physical cross linking, thus improving the flexibility and simultaneously leading the product to achieve certain compactness and air permeability.

More preferably, the plant fiber is a modified plant fiber grafted with acrylate, the nano talcum powder is added to the product obtained after the reaction in the second step and is uniformly stirred, and the plant fiber is added to the product obtained after the reaction in the first step and is uniformly stirred. The acrylic ester is adopted to modify the surface of the plant fiber, so that the hydrophilicity of the plant fiber can be reduced, the interface compatibility between the plant fiber and a hydrophobic resin matrix is improved, the mixing uniformity of the plant fiber and an acrylic ester system is improved, the grafted acrylic ester can generate chemical crosslinking with other active ingredients in subsequent reaction, the physical crosslinking of the plant fiber and other active ingredients, the chemical crosslinking of the grafted acrylic ester and other active ingredients, and the toughness synergistic effect of the ethylene-vinyl acetate copolymer are beneficial to exerting the effect of improving the toughness of products of the plant fiber to the maximum. The specific technique for modifying the plant fiber is the prior art, and any prior art which can realize the grafting of the plant fiber with the acrylic ester can be used in the invention. The modification method of the plant fiber adopted in the embodiment of the application comprises the following steps: firstly, pretreating plant fibers, adding the pretreated plant fibers into a reaction kettle containing sodium sulfite and a dispersion medium for sulfomethylation, then injecting a phthalic anhydride solution, adding horseradish peroxidase for catalytic oxidation to generate phenolic oxygen free radicals on the surfaces of the plant fibers, and then adding isooctyl methacrylate for grafting modification.

Most preferably, the ethylene-vinyl acetate copolymer is 20 to 25 mass percent of vinyl acetate, and the water-soluble polyvinyl alcohol is polyvinyl alcohol 1788.

The invention also provides a special dual-component emulsion for producing the soft stone, which is prepared by the preparation method, wherein the component A and the component B are respectively stored and mixed when in use.

Compared with the prior art, the invention has the following beneficial effects:

1. the polymerization monomer and the functional monomer are properly matched, and the synergistic effect of the ethylene-vinyl acetate copolymer, the nano talcum powder and the modified plant fiber improves the extension capability of the emulsion, so that the flexibility, the compactness and the air permeability of the final film can be obviously improved;

2. the polymerization temperature adopted during production is relatively low, and the monomers cannot flow back or volatilize, so that the production process is relatively green and environment-friendly, and has little harm to the environment;

3. the two components are respectively stored and mixed for use, and the two-component system is stable and uniform during storage and has long quality guarantee period.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The specific modification method of the modified plant fiber used in the following examples is as follows: pretreating the plant fiber: firstly, washing plant fibers with alkali by using a sodium hydroxide solution with the mass concentration of 30% for 1 time, then washing the plant fibers with deionized water for 2 times, finally neutralizing the plant fibers with sulfuric acid with the mass concentration of 20% to be neutral, and then adding the pretreated plant fibers into a reaction kettle; adding a dispersion medium containing sodium sulfite into the reaction kettle, heating to 65 ℃, and keeping the temperature for 40 min; the dispersion medium is a mixed solution of ethanol and water, and the volume ratio is 1: 1; injecting phthalic anhydride solution into the reaction kettle, heating to 104 ℃, then adding horse radish peroxidase for catalytic oxidation reaction, and reacting for 60 min; the purity of the horseradish peroxidase is 4, and the activity is 320 u/mg; adding isooctyl methacrylate EHMA into a reaction kettle, heating to 160 ℃ for graft modification reaction, filtering, washing and drying after 120min to prepare surface modified plant fiber; in the above process, 36 parts by weight of plant fiber, 7 parts by weight of sodium sulfite, 46 parts by weight of dispersion medium, 9 parts by weight of phthalic anhydride, 2 parts by weight of horseradish peroxidase, and 1.5 parts by weight of isooctyl methacrylate.