Modified vinyl acetate-acrylate copolymer emulsion with high solubility and high glass transition temperature and preparation method thereof

Abstract

A disclosed modified vinyl acetate-acrylate copolymerization emulsion with high solubility and high glass transition temperature comprises, in percent by mass, 40%-60% of vinyl acetate, 0.1%-5% of a bridged ring structure copolymerization monomer, 0.1%-5% of butyl acrylate, 0.1%-4.5% of oxirane-epoxypropane block polymer 1, 0.1%-4.5% of oxirane-epoxypropane block polymer 2, 0.1%-1% of a sulfosuccinate derivative, 0.5%-1% of a persulfate initiator, 0.1%-0.5% of a pH conditioning agent, and 25%-40% of water. The obtained emulsion product possesses extremely good storage stability and relatively high solid content. A film formed by the emulsion possesses relatively high glass transition temperature and rapid dissolving performance in styrene.

Description

technical field [0001] The invention belongs to the field of binders, and in particular relates to a modified acetate-acrylic copolymer emulsion with high solubility and high glass transition temperature that can be used in the fiber spinning process. agent. Background technique [0002] In the glass fiber production process, from molten glass to glass fiber monofilament to glass fiber precursor products, it is essential to use a sizing agent to coat and wrap the glass fiber surface to protect the fragile glass fiber , to give glass fiber flexibility, clustering and the interface affinity effect of glass fiber and matrix resin in its downstream application, the dispersion effect of glass fiber in resin, mechanical strength and so on. According to different glass fiber applications, the sizing formulation includes but is not limited to: coupling agent, binder, lubricant, antistatic agent, finishing agent, softener, etc. Among them, the coupling agent mainly provides the fun...

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Problems solved by technology

However, with the application of glass fiber reinforced composite material technology more and more widely, the product performance requirements of composite materials are getting higher and higher, we found that NAPLOY1971 product still has some deficiencies, mainly including: 1) The molecules of the emulsion product are being removed When the water becomes a polymer film, the number-average molecular weight is about 300,000, the glass transition temperature is low, the measured value is about 23 degrees Celsius, and the hardness is low, which makes the stiffness of the glass fiber relatively low. Generally, this emulsion is used as a bond The measured value of the stiffness of glass fiber products is about 120; the cutting and dispersion effects of fibers have not reached the current market demand; The dissolving speed in the medium can no longer meet the requirements of the current glass fiber reinforced resin application; under the unit size, the polymer film material formed after dehydration of every 20 grams of the emulsion, the time to completely dissolve in styrene is 30 minutes; 3) the The solid content of emulsion products can be up to 45%, and the other 55% is water. In the current glass fiber production, it is hoped that a higher solid content, such as 55%, can be achieved to improve logistics efficiency.

[0004] From the analysis of the segment structure of polymer materials, the segment structure of NAPOLY1971 emulsion polymer is mainly vinyl acetate homopolymer structure. The main reason is low; and the leveling of polyvinyl acetate is relatively poor when forming a film, which will cause the coating effect of the film on the glass fiber to be incomplete, which will affect the protective effect on the glass fiber, thus causing The stiffness of glass fiber is low; at the same time, although the solubility of homopolyvinyl acetate in styrene is good, but because the entire chain segment is relatively flat, the main chain is linearly distributed, lacking the support of branch chains to increase the attack space of styrene , so the dissolution rate of this substance in styrene is difficult to increase; from the analysis of the principle of emulsion polymerization, the emulsion polymerization of homopolyvinyl acetate is carried out in micelles, and the polymerization activity of vinyl acetate is relatively high. If there is no suitable surface activity Agent system or emulsification system, can not form sufficient quantity and stable micelle, then the molecular weight of the emulsion particle in micelle is very big, this will affect the storage stability of emulsion product and be difficult to prepare the emulsion product of high solid content, Excessively high solids content may lead to stratification of the emulsion

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