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Method for preparing low-viscosity EVA (ethylene-vinyl acetate) emulsion

A low-viscosity, emulsion technology, applied in the field of preparing low-viscosity EVA emulsion, can solve the problems of poor particle shape and emulsion stability, limited application range, and difficult product storage, etc., to maintain particle shape and toughness strength, reduce product viscosity, The effect of moderate VAc content

Active Publication Date: 2017-03-29
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Therefore, the product prepared by the existing EVA emulsion polymerization process has high viscosity, poor particle shape and emulsion stability, the product is not easy to store, and the application range is limited.

Method used

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  • Method for preparing low-viscosity EVA (ethylene-vinyl acetate) emulsion

Examples

Experimental program
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preparation example Construction

[0024] Such as figure 1 The shown copolymerization reaction device for the preparation of low-viscosity EVA emulsion. A single-pot batch operation is adopted, including a copolymerization reactor 1, a feeding mechanism and a product post-treatment part. Described copolymerization reactor 1 top is provided with emulsifier / colloid protective agent feed inlet, initiator feed inlet, pH value adjuster feed inlet and vinyl acetate liquid phase feed inlet, and N 2 and ethylene feed port. The emulsifier / colloid protective agent tank 2 is communicated with the copolymerization reactor 1 through the high-pressure metering pump 6-2, the initiator tank 3 is communicated with the copolymerization reactor 1 through the high-pressure metering pump 6-3, and the pH value regulator tank 4-1 is communicated with the copolymerization reactor 1 through the high-pressure metering pump 6-3. The metering pump 6-4 communicates with the copolymerization reactor 1, and the VAc monomer tank 5 communica...

Embodiment 1

[0029] Using ammonium persulfate as initiator, the total amount is 0.3wt% of vinyl acetate; O / W system, the amount of surfactant op-10 is 10.0wt% of the amount of VAc monomer; acetalized colloidal protective agent The amount of PVA is 3.0wt% of the amount of VAc monomers, and the degree of acetalization of PVA is 8.0%; the amount of pH regulator sodium bicarbonate is 0.5wt% of the amount of VAc monomers; the polymerization reaction temperature is 75°C, and the ethylene reaction pressure is 75.0MPa , The polymerization reaction time is 5h, and the pH value of the reaction process is controlled at 6.5. Under these conditions, the VAc content of the polymerization product is 65.9wt%, the viscosity of the emulsion is 91mpa.s, the stability of the emulsion is good, and the emulsion can be stored stably for 15 months.

Embodiment 2

[0031] Using ammonium persulfate as initiator, the total amount is 0.3wt% of vinyl acetate; O / W system, the amount of surfactant op-10 is 10.0wt% of the amount of VAc monomer; acetalized colloidal protective agent The amount of PVA is 3.0wt% of the amount of VAc monomer, and the degree of acetalization of PVA is 8.5%; the amount of pH value regulator sodium bicarbonate is 0.5wt% of the amount of VAc monomer; the polymerization temperature is 75°C, and the ethylene reaction pressure is 75.0MPa , The polymerization reaction time is 5h, and the pH value of the reaction process is controlled at 6.5. Under these conditions, the VAc content of the polymerization product is 65.9wt%, the emulsion viscosity is 98mpa.s, the emulsion stability is good, and the emulsion can be stored stably for 14 months.

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Abstract

The invention relates to a method for preparing a low-viscosity EVA (ethylene-vinyl acetate) emulsion. The method comprises the following steps: adding a vinyl acetate (VAc) monomer and acetalated PVA (polyvinyl alcohol) into an emulsifier water liquid; and then adding initiator to initiate emulsion polymerization so as to perform copolymerization reaction on ethylene and the VAc monomer. According to the invention, the acetalated PVA is used as colloid protective agent, so that the viscosity of the system can be obviously reduced, and the EVA emulsion product having excellent particle morphology and favorable stability is obtained, thereby greatly widening the application range of the EVA emulsion to meet different requirements. Besides, a single-kettle intermittent process avoids the problems of a multi-kettle operation process such as high difficulty, high equipment cost, high energy consumption and the like, thereby achieving higher industrial application value.

Description

technical field [0001] The invention relates to a method for preparing low-viscosity EVA emulsion. Background technique [0002] The EVA emulsion produced by emulsion polymerization has a moderate content of vinyl acetate (VAc), and the product has excellent flexibility, transparency, low temperature flexibility, weather resistance, chemical corrosion resistance and compatibility with fillers and color masterbatches sex. EVA emulsion products have high strength, non-toxic and environmental protection, and excellent bonding performance. They can be used in textiles, light industry, coatings, plastic toughening, construction materials, polymer blending coatings, rubber modification and other fields. They are widely used. The demand at home and abroad continues to increase, and it has developed rapidly in recent years. In the prior art, the method for preparing EVA emulsion includes adding VAc monomer and colloidal protective agent into an emulsifier aqueous solution, and the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08F210/02C08F218/08C08F2/30
Inventor 陈博于鲁强刘小萌刘金伟
Owner CHINA PETROLEUM & CHEM CORP