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CN-121991275-A - Vinyl acetate-ethylene copolymer emulsion, preparation method thereof and polymer cement waterproof coating

CN121991275ACN 121991275 ACN121991275 ACN 121991275ACN-121991275-A

Abstract

The invention relates to the technical field of vinyl acetate-ethylene copolymer emulsion, and discloses a vinyl acetate-ethylene copolymer emulsion, a preparation method thereof and a polymer cement waterproof coating, wherein the copolymer emulsion comprises, by mass, 30-45 parts of vinyl acetate, 14-18 parts of ethylene, 0.3-0.7 part of an emulsifying agent, 1-3 parts of a protective colloid, 0.5-2.5 parts of a functional high polymer and 40-45 parts of water, wherein the protective colloid is polyvinyl alcohol and/or hydroxyethyl cellulose, and the functional high polymer is polyacrylamide. The polymer cement waterproof paint has higher low-shear viscosity, so that the sagging resistance of the JS waterproof paint is improved.

Inventors

  • WU JIANGHONG
  • LIU JINGJING
  • ZHANG BO
  • LUO LIHUA
  • QIU XUAN

Assignees

  • 中国石油化工股份有限公司
  • 中国石化集团重庆川维化工有限公司

Dates

Publication Date
20260508
Application Date
20241107

Claims (10)

  1. 1. The vinyl acetate-ethylene copolymer emulsion is characterized by comprising the following raw material components in parts by weight: 30-45 parts of vinyl acetate; 14-18 parts of ethylene; 0.3-0.7 part of emulsifying agent; 1-3 parts of protective colloid; 0.5-2.5 parts of functional high molecular polymer; 40-45 parts by weight of water; Wherein the protective colloid is polyvinyl alcohol and/or hydroxyethyl cellulose, and the functional high polymer is polyacrylamide.
  2. 2. The co-emulsion of claim 1, wherein the emulsifier is a nonionic emulsifier; Preferably, the nonionic emulsifier comprises one or more of nonylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether, isomeric carbon trideceth polyoxyethylene ether and oleyl alcohol polyoxyethylene ether; more preferably, the nonionic emulsifier is fatty alcohol polyoxyethylene ether and/or isomeric carbon trideceth.
  3. 3. The copolymer emulsion of claim 1, wherein the polyacrylamide has a viscosity average molecular weight of 300-800 tens of thousands; And/or, the polymerization degree of the polyvinyl alcohol is 500-2000, and the alcoholysis degree is 80-99.5%.
  4. 4. A co-emulsion according to any one of claims 1-3, wherein the co-emulsion further comprises, in parts by mass: 0.01-0.06 parts of oxidant; 0.01-0.06 parts of reducing agent; 0.3-0.6 part of bactericide; 0.3-0.6 part of PH regulator; 0.1-0.3 part of defoaming agent.
  5. 5. A process for preparing a vinyl acetate-ethylene copolymer emulsion as claimed in any one of claims 1 to 4, comprising: (1) Mixing protective colloid, emulsifier, functional high molecular polymer, part of vinyl acetate, part of ethylene and water; (2) Contacting each reactant in the step (1) with a part of oxidant, a part of reducing agent, another part of vinyl acetate and another part of ethylene at a certain temperature and pressure to perform a first reaction; (3) And (3) contacting the product obtained in the step (2) with another part of oxidant and another part of reducing agent to perform a second reaction and defoaming treatment, and contacting the reaction product with a defoaming agent, a pH regulator and a bactericide to obtain the vinyl acetate-ethylene copolymer.
  6. 6. The process according to claim 5, wherein the ratio by weight of the amount of one part of vinyl acetate to the amount of the other part of vinyl acetate is (0.6-4) 1; and/or the weight ratio of the amount of one part of ethylene to the other part of ethylene is (0.5-1): 1; preferably, the following parts by weight are added: 30-45 parts by weight of total amount of one part of vinyl acetate and the other part of vinyl acetate; The total amount of one part of ethylene and the other part of ethylene is 14-18 parts by weight.
  7. 7. The preparation method according to claim 5, wherein in the step (2), the certain temperature and pressure conditions include a temperature of 40-100 ℃ and a pressure of 3-8.5MPa; And/or the addition rates of the part of the oxidizing agent and the part of the reducing agent are the same or different and are each 1-4kg/min; And/or the addition rates of the other part of the oxidizing agent and the other part of the reducing agent are the same or different and are each 4-8kg/min; And/or in step (3), the conditions of the second reaction include a temperature of 60-90 ℃ and a pressure of 0.5-8.5MPa.
  8. 8. A polymer cement waterproof paint, characterized in that it contains the vinyl acetate-ethylene copolymer emulsion according to any one of claims 1 to 4 and cement.
  9. 9. The polymer cement waterproof paint according to claim 8, wherein the vinyl acetate-ethylene copolymer emulsion is used in an amount of 20 to 60% by weight based on the total weight of the polymer cement waterproof paint.
  10. 10. The polymer cement waterproof coating according to claim 8 or 9, wherein the polymer cement waterproof coating has a low shear viscosity of 5000-10000mpa.s, preferably 5200-9950mpa.s.

Description

Vinyl acetate-ethylene copolymer emulsion, preparation method thereof and polymer cement waterproof coating Technical Field The invention relates to the technical field of vinyl acetate-ethylene copolymer emulsion, in particular to vinyl acetate-ethylene copolymer emulsion, a preparation method thereof and a polymer cement waterproof coating. Background The polymer cement (JS) waterproof paint belongs to a flexible two-component waterproof material, and consists of a liquid material part and a powder material part, wherein the liquid-powder ratio is generally 1:0.8-1:2.5, and at present, an acrylic acid or vinyl acetate-ethylene copolymer emulsion (VAE emulsion) is commonly used as a polymer emulsion. The polymer waterproof coating has flexible construction property, excellent environmental protection property, elasticity, low-temperature flexibility and waterproof property, has good adhesion to various base materials, and is widely used for decoration and waterproof of roofs, inner and outer walls, kitchens and bathrooms and the like. The construction process of the JS waterproof paint generally adopts a brushing or rolling coating mode, requires construction for two to three times, and the basic thickness of the JS waterproof paint is required to be 1.5-2.0 mm in GB 50345-2012 technical Specification for roof engineering [4] and GB 50108-2008 technical Specification for waterproof in underground engineering [5 ]. In the construction process of the JS waterproof coating, sagging easily occurs at the vertical surface or edges and the like at the joint of the horizontal surface and the vertical surface, and the sagging is a common coating defect, namely, the coating has a phenomenon of downward flowing, and when severe, the coating shifts downwards like tearing, so that the upper part is exposed, and the lower parts are stacked together. The waterproof coating at the sagging part is uneven in thickness, so that the appearance is influenced, and the waterproof effect is directly influenced. The conventional VAE emulsion for JS waterproof paint does not have sagging resistance, and two improvement methods are generally adopted. The first improvement method is to add acrylic acid and its lipid monomer to copolymerize with vinyl acetate and ethylene, but the copolymerization is difficult and the scale is easy to build in the polymerization kettle. The second improvement method is to add an acrylic thickener with alkali thickening property into the common VAE emulsion, so that the production process is increased, and the sagging resistance is easily influenced by the PH of the VAE emulsion. Therefore, research and development of a polymer cement waterproof coating with sagging resistance have important significance. Disclosure of Invention The invention aims to overcome the defect that the conventional VAE emulsion used for JS waterproof paint does not have the sagging resistance function in the prior art, and provides a vinyl acetate-ethylene copolymer emulsion, a preparation method thereof and a polymer cement waterproof paint. In order to achieve the above object, the first aspect of the present invention provides a vinyl acetate-ethylene copolymer emulsion, wherein the copolymer emulsion comprises the following raw material components in parts by weight: 30-45 parts of vinyl acetate; 14-18 parts of ethylene; 0.3-0.7 part of emulsifying agent; 1-3 parts of protective colloid; 0.5-2.5 parts of functional high molecular polymer; 40-45 parts by weight of water; Wherein the protective colloid is polyvinyl alcohol and/or hydroxyethyl cellulose, and the functional high polymer is polyacrylamide. The second aspect of the present invention provides a method for preparing the vinyl acetate-ethylene copolymer emulsion, wherein the method comprises the following steps: (1) Mixing protective colloid, emulsifier, functional high molecular polymer, part of vinyl acetate, part of ethylene and water in contact; (2) Contacting each reactant in the step (1) with a part of oxidant, a part of reducing agent, another part of vinyl acetate and another part of ethylene at a certain temperature and pressure to perform a first reaction; (3) And (3) contacting the product obtained in the step (2) with another part of oxidant and another part of reducing agent to perform a second reaction and defoaming treatment, and contacting the reaction product with a defoaming agent, a pH regulator and a bactericide to obtain the vinyl acetate-ethylene copolymer. In a third aspect, the invention provides a polymer cement waterproof coating, wherein the polymer cement waterproof coating contains the vinyl acetate-ethylene copolymer emulsion and cement. Through the technical scheme, the technical scheme provided by the invention has the following advantages: (1) The JS waterproof paint with excellent sagging resistance can be prepared by the emulsion without adding thickening agents and other high molecular polymers. (2) The method has simple process