JPH0368888B2 - - Google Patents

Description

[Detailed description of the invention]

Vinyl acetate resin is essentially a water-insoluble resin, but by copolymerizing it with a small amount of ethylenically unsaturated carboxylic acid alkali salt, ammonium salt, or ethylenically unsaturated sulfonic acid alkali salt, it can be made water-soluble. It is now widely used in water-based applications such as pastes, adhesives, and paper processing agents. However, as the uses of water-soluble vinyl acetate resin expand, various performances are required. For example, in applications such as ceramic binders, the presence of trace amounts of alkali metals causes deterioration of the performance of ceramics. Therefore, conventional products cannot meet the wide variety of performance requirements, such as making it impossible to use them for these purposes. However, as a result of extensive research to develop a vinyl acetate resin that is water-soluble even in the absence of such alkali metals, the present inventors found that the general formula

[Formula] When copolymerizing the polyoxyalkylene (meth)allyl ether represented by the formula and vinyl acetate, the content of the polyoxyalkylene (meth)allyl ether is 1 to 30 mol%. The present inventors have discovered that a modified vinyl acetate resin having an alkylene group in the polymer side chain satisfies the objective and has completed the present invention. The oxyalkylene group referred to in the present invention has the general formula

It has a structure represented by the formula: [wherein R ¹ and R ² are hydrogen or an alkyl group, and n is an integer from 1 to 100]. Oxyalkylene groups in which n is advantageously 1 to 50, preferably about 3 to 50 are practical, and polyoxyethylene groups, polyoxypropylene groups, polyoxybutylene groups, etc. are effective. Further, R is hydrogen or a methyl group. general formula

[Formula] [R, R ¹ , R ² , n are the same as above] Specific examples of polyoxyalkylene (meth)allyl ether include polyoxyethylene (meth)allyl ether, polyoxypropylene (meth)allyl Examples include ether. Copolymerization with vinyl acetate is not particularly limited and any known polymerization method may be used, but solution polymerization using an alcohol such as methanol or ethanol as a solvent is usually carried out. In this method, the monomers are charged by first charging the entire amount of vinyl acetate and a portion of the polyoxyalkylene (meth)allyl ether to start polymerization, and then polymerizing the remaining polyoxyalkylene (meth)allyl ether. Any method may be used, such as adding continuously or in parts during the period, or adding both at once. The copolymerization reaction is carried out using a known radical polymerization catalyst such as azobisisobutyronitrile, acetyl peroxide, benzoyl peroxide, and lauroyl peroxide. Further, the reaction temperature is selected from a range of about 50°C to the boiling point. The reaction is carried out by removing unreacted monomers in accordance with conventional methods to obtain the desired product. In this application, it is basically a binary copolymer of polyoxyalkylene (meth)allyl ether and vinyl acetate, but a small amount of monomers that can be copolymerized with these may be copolymerized without detracting from the spirit of the invention. I can do it. The proportion of polyoxyalkylene (meth)allyl ether in the vinyl acetate resin of the present invention can be varied arbitrarily. That is, if the purpose is simply to impart affinity with water to the vinyl acetate resin, the proportion may be relatively small, but if the purpose is to make the vinyl acetate resin water-soluble, it is necessary to introduce a considerably large amount. In order to obtain water solubility, it is usually necessary to introduce 1 mol% or more.
Desirable content is 1 to 30 mol%, preferably 1 to 30 mol%
It is 20 mol%. The vinyl acetate resin can be used for various purposes in the form of powder, block, or solution. These are listed below. (1) Molded products Fibers, films, sheets, pipes, tubes, leak-proof membranes, temporary coatings, water-soluble fibers for chemical laces (2) Adhesives Adhesives and adhesives for wood, paper, aluminum foil, plastics, etc. , rewetting agent, binder for nonwoven fabrics,
Fibrous binders, binders for various building materials such as gypsum board and fiberboard, binders for various powder granulation, ceramic binders, additives for cement and mortar, hot melt adhesives, pressure sensitive adhesives, dye fixing agents (3 ) Coating agent Clear coating agent for paper, pigment coating agent for paper, internal sizing agent for paper, binder and overcoating agent for thermal recording paper, sizing agent for textile products, paper sizing agent, fiber processing agent, leather finishing Agents, paints, antifogging agents, metal corrosion inhibitors, brighteners for galvanizing, antistatic agents, conductive agents (4) Blending agents for hydrophobic resins Antistatic agents for hydrophobic resins, hydrophilicity imparting agents, composites Additives for fibers, films, and other molded products (5) Dispersion stabilizers for suspension Pigment dispersion stabilizers for paints, India ink, watercolor colors, adhesives, etc., vinyl chloride, vinylidene chloride, styrene, (meth)acrylate, vinyl acetate Dispersion stabilizers and dispersion aids for suspension polymerization of various vinyl compounds such as (6) Emulsifiers Emulsifiers for emulsion polymerization of ethylenically unsaturated compounds and butadiene compounds, hydrophobic resins such as polyolefins and polyester resins, epoxy resins, Post-emulsifiers such as paraffin and bitumen (7) Thickeners Thickeners for various emulsions (8) Flocculants Flocculants for suspended and dissolved substances in water, aqueous improvers for pulp slurry (9) Soil conditioners (10) Related to photosensitive agent and electrosensitive agent Next, the method of the present invention will be explained in more detail by giving examples. Example 1 900 parts of vinyl acetate, 415 parts of polyoxyethylene allyl ether (n=15), and 105 parts of methanol were placed in a polymerization tank equipped with a reflux condenser, dropping funnel, thermometer, and stirrer, and the temperature was raised while stirring. 60
A solution prepared by dissolving 0.12 parts of azobisisobutyronitrile in 20 parts of methanol was added at 0.degree. C. to initiate polymerization. After 8 hours, the polymerization was stopped when the polymerization rate reached 96%. The copolymerization solution was purified according to a conventional method to obtain a polyoxyethylene monoallyl ether/vinyl acetate copolymer. The characteristic values of the obtained copolymer were as follows. Polyoxyethylene allyl ether content;
4.1 mol% Vinyl acetate content: 95.9 mol% 4% aqueous solution viscosity at 20°C: 1.2 centipoise (Hepler viscometer) NMR (δppm) A peak of −(CH ₂ CH ₂ O) − is observed at 3.7 δppm. Example 2 The same method as in Example 1 was carried out except that 429 parts of polyoxyethylene allyl ether (n=50) was used in place of the polyoxyethylene allyl ether (n=15) in Example 1. The characteristic values of the obtained copolymer were as follows. Polyoxyethylene monoallyl ether content: 1.8 mol% Vinyl acetate content: 98.2 mol% NMR (δppm) is the same as Example 1. Example 3 Polyoxypropylene allyl with n=10 was used instead of polyoxyethylene allyl ether in Example 1. The experiment was conducted in accordance with the same example except that ether was used. The composition of the obtained copolymer was as follows. Polyoxypropylene allyl ether content;
3.8 mol% Vinyl acetate content; 96.2 mol%

Claims (1)

[Scope of Claims] 1 General Formula [Formula] Here, [R is hydrogen or a methyl group, R ¹ and R ² are hydrogen or an alkyl group, and n is a polyoxyalkylene (meth)allyl represented by an integer from 1 to 100. Production of a modified vinyl acetate resin having an oxyalkylene group in the polymer side chain, which is characterized by copolymerizing ether and vinyl acetate at a ratio such that the content of polyoxyalkylene (meth)allyl ether is 1 to 30 mol%. Method.