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CN-121991270-A - Vinyl acetate-ethylene copolymer emulsion and preparation method and application thereof

CN121991270ACN 121991270 ACN121991270 ACN 121991270ACN-121991270-A

Abstract

The invention relates to the technical field of preparation of vinyl acetate-ethylene copolymer emulsion, and discloses a vinyl acetate-ethylene copolymer emulsion, a preparation method and application thereof, the copolymer emulsion is prepared from raw materials including monomers, protective colloid, a composite emulsifier, an initiating system, ethylene and deionized water, wherein the monomers comprise vinyl acetate and acrylic acid, and the composite emulsifier is a mixture of a nonionic emulsifier and a reactive emulsifier. The vinyl acetate-ethylene copolymer emulsion has the advantages of good particle size consistency, narrow particle size distribution and high light transmittance after film formation.

Inventors

  • QIU XUAN
  • CAO YONG
  • LIU JINGJING
  • ZHANG BO
  • LUO LIHUA
  • XU XIAOSONG

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 being prepared from raw materials including monomers, protective colloid, a composite emulsifier, an initiating system, ethylene and deionized water, wherein the monomers comprise vinyl acetate and acrylic acid, and the composite emulsifier is a mixture of a nonionic emulsifier and a reactive emulsifier.
  2. 2. The copolymer emulsion of claim 1, wherein the nonionic emulsifier comprises isomeric alcohol polyoxyethylene ethers and/or secondary alkyl alcohol ethers; and/or the reactive emulsifier comprises one or more of vinyl sulfonate, sodium acrylamido isopropyl sulfonate and sodium allyl ether hydroxypropyl sulfonate; And/or the weight ratio of the content of the nonionic emulsifier to the content of the reactive emulsifier is (1-3): 1, preferably (1.5-2.5): 1.
  3. 3. The copolymer emulsion according to claim 1, wherein acrylic acid comprises 0.3-0.5%, preferably 0.35-0.45% of the total amount of vinyl acetate.
  4. 4. The copolymer emulsion of claim 1, wherein the protective colloid is polyvinyl alcohol; preferably, the polyvinyl alcohol has a polymerization degree of 800 to 1400 and an alcoholysis degree of 86 to 92mol%.
  5. 5. The copolymer emulsion according to claim 1, wherein the copolymer emulsion is prepared from raw materials including 42-65 parts by weight of monomer, 0.5-1.5 parts by weight of protective colloid, 1-2 parts by weight of composite emulsifier, 0.1-0.3 parts by weight of initiator system and 36-52 parts by weight of deionized water; Preferably, the copolymer emulsion is prepared from raw materials comprising 45-62 parts by weight of monomer, 0.6-1.2 parts by weight of protective colloid, 1.2-1.8 parts by weight of composite emulsifier, 0.12-0.24 parts by weight of initiating system and 40-50 parts by weight of deionized water.
  6. 6. The co-emulsion according to any one of claims 1-5, wherein the co-emulsion is a mono-disperse emulsion and the volume average particle size of the co-emulsion is 0.6-0.8 μm, preferably 0.689-0.745 μm; And/or the particle size uniformity of the copolymer emulsion is between 0.1 and 0.2, preferably between 0.175 and 0.19; and/or the ultraviolet light transmittance of the copolymer emulsion after film formation is between 88 and 93 percent.
  7. 7. A process for preparing a vinyl acetate-ethylene copolymer emulsion as claimed in any one of claims 1 to 6, comprising: (1) Mixing protective colloid and deionized water to obtain protective colloid solution; (2) Mixing half of the protective colloid solution, a composite emulsifier, vinyl acetate, acrylic acid and deionized water to obtain a pre-emulsion; (3) In the presence of an initiating system, contacting the other half of the protective colloid solution, a part of the pre-emulsion, deionized water and ethylene to perform a first reaction to obtain a product; (4) And (3) contacting the product, the other part of the pre-emulsion and ethylene to perform a second reaction to obtain the vinyl acetate-ethylene copolymer emulsion.
  8. 8. The process according to claim 7, wherein in step (2) a portion of the pre-emulsion is 3-18 wt%, preferably 5-15 wt%, based on the total weight of the pre-emulsion; and/or in step (4), the addition time of the other part of the pre-emulsion is 180-240min, preferably 190-230min.
  9. 9. The preparation method according to claim 7, wherein the conditions of the first reaction include a temperature of 50-54 ℃ and a pressure of 3-3.5MPa; And/or, in step (3), the addition rate of the initiating system is 0.5-1kg/min; and/or the conditions of the second reaction include a temperature of 76-80 ℃ and a pressure of 5.5-6MPa.
  10. 10. Use of a vinyl acetate-ethylene copolymer emulsion as defined in any one of claims 1 to 6 in paper coating.

Description

Vinyl acetate-ethylene copolymer emulsion and preparation method and application thereof Technical Field The invention relates to the technical field of preparation of vinyl acetate-ethylene copolymer emulsion, in particular to vinyl acetate-ethylene copolymer emulsion, and a preparation method and application thereof. Background The paper coating is a process for coating a layer of chemical substances on the surface of paper, the coating components mainly comprise pigment, adhesive and various auxiliary agents, and the paper coating mainly has the effects of increasing the physical properties of paper, improving the surface properties of the paper, improving the printing quality and the like. With the high-speed development of commercial printing, the vinyl acetate-ethylene copolymer emulsion is used as an environment-friendly and low-cost adhesive, and is widely applied to advertisement paper, but the problems of wide particle size distribution, poor transparency after film formation, poor pigment and filler dispersibility and the like exist at present. Therefore, research and development of a vinyl acetate-ethylene copolymer emulsion with good particle size consistency, narrow particle size distribution and high light transmittance after film formation are of great significance. Disclosure of Invention The invention aims to overcome the defects of wide particle size distribution, poor transparency after film formation and poor pigment and filler dispersibility of vinyl acetate-ethylene copolymer emulsion in the prior art, and provides a vinyl acetate-ethylene copolymer emulsion, a preparation method and application thereof. 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 is prepared from raw materials including a monomer, a protective colloid, a composite emulsifier, an initiating system, ethylene and deionized water, wherein the monomer comprises vinyl acetate and acrylic acid, and the composite emulsifier is a mixture of a nonionic emulsifier and a reactive emulsifier. 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 and deionized water to obtain protective colloid solution; (2) Mixing half of the protective colloid solution, a composite emulsifier, vinyl acetate, acrylic acid and deionized water to obtain a pre-emulsion; (3) In the presence of an initiating system, contacting the other half of the protective colloid solution, a part of the pre-emulsion, deionized water and ethylene to perform a first reaction to obtain a product; (4) And (3) contacting the product, the other part of the pre-emulsion and ethylene to perform a second reaction to obtain the vinyl acetate-ethylene copolymer emulsion. In a third aspect, the invention provides the use of a vinyl acetate-ethylene copolymer emulsion as described above in paper coating. Through the technical scheme, the invention has the beneficial effects that: (1) The vinyl acetate-ethylene copolymer emulsion prepared by the method is a monodisperse emulsion, has narrow particle size distribution, good uniformity and good pigment and filler dispersibility, and the particle size consistency is preferably between 0.175 and 0.190; (2) The vinyl acetate-ethylene copolymer emulsion prepared by the method has high transparency after film formation, the ultraviolet light transmittance is between 88 and 93 percent, and the color saturation is high when the emulsion is used for paper coating; (3) The preparation method is simple and is beneficial to realizing industrial production. Drawings FIG. 1 is a graph showing the particle size distribution of a vinyl acetate-ethylene copolymer emulsion prepared in example 1; FIG. 2 is a graph showing the particle size distribution of the vinyl acetate-ethylene copolymer emulsion prepared in example 2; FIG. 3 is a graph showing the particle size distribution of the vinyl acetate-ethylene copolymer emulsion prepared in example 3; FIG. 4 is a graph showing the particle size distribution of the vinyl acetate-ethylene copolymer emulsion prepared in example 4; FIG. 5 is a graph showing the particle size distribution of the vinyl acetate-ethylene copolymer emulsion prepared in example 5; FIG. 6 is a graph showing the particle size distribution of the vinyl acetate-ethylene copolymer emulsion prepared in comparative example 1; FIG. 7 is a graph showing the particle size distribution of the vinyl acetate-ethylene copolymer emulsion prepared in comparative example 2; FIG. 8 is a graph showing the particle size distribution of the vinyl acetate-ethylene copolymer emulsion obtained in comparative example 3. Detailed Description The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values ap