JPH11217475A - Vinyl chloride-vinyl acetate copolymer composition having stable quality, hardly undergoing change in quality - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a vinyl chloride-vinyl acetate copolymer compsn. which has a stable quality, hardly undergoing the change in quality, by carrying out the copolymn. of vinyl chloride and vinyl acetate until the unreacted vinyl acetate content in the compsn. reaches a specified level or lower. SOLUTION: Vinyl chloride and vinyl acetate are copolymerized by charging a solvent (e.g. an org. solvent or water) into a reactor, charging both the monomers into the reactor, then adding a free-radical generator (e.g. t-butyl peroxybenzoate), and stirrig the reactants under heating at a specified temp. At the intermediate stage of the reaction, a reducing agent selected from among org. compds. (e.g. L-ascorbic acid), metal ions (e.g. copper ions), and salts (e.g. sodium sulfite) is added to improve the efficiency of free radical generation. Then, a monomer copolymerizable with vinyl acetate (e.g. vinyl chloride, vinylidene chloride, or methyl acylate) is added and the reaction is continued. Thus is obtd. a copolymer compsn. having an unreacted vinyl acetate content (measured by chromatography, etc.), of 1 wt.% or lower and having a quality with small variation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vinyl chloride-vinyl acetate copolymer composition having a low quality and a stable quality, and a method for producing the same. The present invention relates to a production method characterized in that the content is not more than% by weight and the composition.

[0002]

2. Description of the Related Art Paints to be coated on wood, concrete, metal, paper, plastic, etc., and adhesives, pigments, dyes, and the like for laminating the same are dissolved or dispersed and drawn on wood, concrete, metal, paper, plastic, and the like. Inks that fix pigments, dyes, etc. by drying are widely used. These paints, adhesives, inks, etc. are prepared by dissolving or dispersing a polymer that does not volatilize by heating in a solvent or dispersion medium that volatilizes by heating, mixing pigments, dyes, fillers, various additives, etc. After being manufactured and coated, the volatile components are removed by heating or the like, thereby achieving the intended function.

[0003] Polymers contained in resin compositions used for paints, adhesives, inks, etc. include acrylic polymers, vinylidene chloride-based polymers, styrene-based polymers, ethylene-vinyl acetate-based copolymers, and polyesters. Polymers are used, but vinyl chloride-vinyl acetate copolymers are used in paints, adhesives, inks, etc. due to their excellent properties such as adhesion, flexibility and flame retardancy. Widely used as things. As volatile components in the vinyl chloride-vinyl acetate copolymer composition, solvents or dispersion media such as alcohols, esters, ketones, aromatic hydrocarbons, and water are used.

[0004] A vinyl chloride-vinyl acetate copolymer composition is used as a solvent or a dispersion medium in the presence of vinyl chloride, vinyl acetate and monomers, which are precursors of the vinyl chloride-vinyl acetate copolymer. A common production method is to mix and polymerize copolymerizable monomers to form a polymer and then prepare a solid content with a solvent or a dispersion medium as necessary.

In the case of a vinyl chloride-vinyl acetate copolymer, the reactivity ratio between vinyl chloride and vinyl acetate is different, and the vinyl chloride is consumed more. Therefore, at the end of the polymerization, vinyl acetate is produced in the reaction system. Becomes more present than vinyl chloride. Then, the polymerization reaction is usually terminated when the rate of vinyl acetate increases and the reaction rate decreases. Therefore, the unreacted vinyl acetate is contained in the vinyl chloride-vinyl acetate copolymer composition, and the amount thereof is 5% based on the vinyl chloride-vinyl acetate copolymer.
% By weight.

Conventionally, in such a vinyl chloride-vinyl acetate copolymer composition, there has been a problem that the quality of the coating varies when the coating is formed, and various measures have been taken to improve the problem, for example, the addition of a stabilizer or the like. Studies have been made on the adjustment of the composition, molecular weight, etc. of the copolymer by the polymerization recipe. However, a clear correlation has not always been found between the composition and the like of the copolymer and the variation in quality.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to improve the variation in the quality of such a vinyl chloride-vinyl acetate copolymer composition and to obtain the stable composition.

[0008]

Means for Solving the Problems The present inventors have found that in a vinyl chloride-vinyl acetate copolymer composition in which a considerable amount of unreacted vinyl acetate has conventionally remained, unreacted vinyl compounds contained in volatile components are contained. Vinyl acetate has an ester group that is its polar functional group.Even if only organic solvent is used without using water, it is affected by atmospheric moisture and deteriorates during preservation, and paints, adhesives, inks, etc. In order to elucidate that it has a great effect on the quality variation at the time of production and / or after production, and as a result, to improve the quality variation, the residual unreacted component in the vinyl chloride-vinyl acetate copolymer composition is required. They found that the amount of vinyl acetate should be reduced.

That is, a first aspect of the present invention is that the unreacted vinyl acetate content in the composition is 1% by weight or less, and the quality of the vinyl chloride-vinyl acetate copolymer is low and the quality is stable. A composition. According to a second aspect of the present invention, in the production of a vinyl chloride-vinyl acetate copolymer composition, polymerization is performed until the content of unreacted vinyl acetate in the composition becomes 1% by weight or less. Of vinyl chloride
This is a method for producing a vinyl acetate-based copolymer composition. A third invention is the production method according to the second invention, wherein a radical generator is added at an intermediate stage of the polymerization. The fourth invention is the production method according to the third invention, wherein the radical generator added at the intermediate stage of the polymerization is a reducing agent. The fifth invention is the production method according to the second, third or fourth invention, wherein vinyl chloride is added at an intermediate stage of the polymerization.

[0010]

DETAILED DESCRIPTION OF THE INVENTION In the method for producing a vinyl chloride-vinyl acetate copolymer composition of the present invention, polymerization is continued until the content of unreacted vinyl acetate in the composition becomes 1% by weight or less,
The monomers need to be almost completely polymerized. That is, the polymerization is usually carried out by mixing a vinyl chloride-vinyl acetate copolymer precursor monomer, vinyl chloride, vinyl acetate, and a copolymerizable monomer as needed with a solvent or a dispersion medium. It is performed by the manufacturing method of Solution polymerization, emulsion polymerization,
Any method such as a bulk polymerization method may be used. At the end of the polymerization, the ratio of vinyl acetate to vinyl chloride in the reaction system increases and the reaction rate decreases, but at this point, the polymerization reaction is not terminated and the unreacted amount in the vinyl chloride-vinyl acetate copolymer composition is not increased. The polymerization is continued until the amount of vinyl acetate in the reaction becomes 1% by weight or less. Examples of the method include generating a radical in the polymerization system and adding a monomer copolymerizable with vinyl acetate. Here, vinyl chloride
If the content of residual unreacted vinyl acetate in the vinyl acetate copolymer composition is large and exceeds 1% by weight, when the composition is used as a paint, ink or adhesive, there is a large amount of deterioration and the quality is poor. Become a stable product.

As a method for generating a radical, a method used in a usual polymerization reaction can be used. For example, a heating operation, addition of a radical generator, addition of a reducing agent, and the like, are not limited thereto, and may be based on unreacted components of the radical generator added at the start of polymerization. .

The timing of the heating operation is not particularly limited as long as it is an intermediate stage of the polymerization, and may be continuous or discontinuous. The temperature is preferably a high temperature at which the reactivity increases, and may be changed stepwise or sequentially. The time for which the heating operation is continued can also be appropriately selected according to the content of unreacted vinyl acetate in the vinyl chloride-vinyl acetate copolymer composition and the like.

The radical generator includes t-butyl peroxy neodecanoate, t-butyl peroxy pivalate,
organic peroxides such as t-butylperoxy-2-ethylhexanoate, diisopropylperoxydicarbonate, lauroyl peroxide, benzoyl peroxide, t-butyl hydroperoxide and t-butylperoxybenzoate; '-Azobisisobutyronitrile, 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2-methylbutyronitrile), 2,2'-azobis (2,4 -Dimethyl-
Azo compounds such as 4-methoxyvaleronitrile), 2,2′-azobis [2- [5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, potassium persulfate, sodium persulfate, ammonium persulfate, etc. However, as long as it generates a radical, the present invention is not limited thereto. There is no problem if used alone or in combination of two or more. Further, there is no problem even when used in combination with a reducing agent. The timing of adding the radical generator is not particularly limited as long as it is an intermediate stage of the polymerization, and can be appropriately selected according to the unreacted vinyl acetate content in the vinyl chloride-vinyl acetate copolymer composition. .
The additional amount of the radical generator can be appropriately selected according to the unreacted vinyl acetate content in the vinyl chloride-vinyl acetate copolymer composition, and the like.

The reducing agent may be an organic compound such as L-ascorbic acid, Rongalit C, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, dimethylaniline, copper ion, iron ion, silver ion ,
There are manganese ions, aluminum ions, zinc ions, metal ions such as boron ions, and salts such as sodium sulfite and cerium sulfate, but are not limited to these as long as they improve the radical generation efficiency of the radical generator. is not. There is no problem if used alone or in combination of two or more. The timing of adding the reducing agent is not particularly limited as long as it is an intermediate stage of the polymerization, and can be appropriately selected according to the content of the unreacted radical generator in the vinyl chloride-vinyl acetate copolymer composition, and the like. . The additional amount of the reducing agent can be appropriately selected according to the content of the unreacted radical generator in the vinyl chloride-vinyl acetate copolymer composition.

As monomers copolymerizable with vinyl acetate, vinyl chloride, vinylidene chloride, methyl acrylate, butyl acrylate, acrylonitrile, methyl methacrylate,
Ethyl methacrylate, butyl methacrylate, methacrylonitrile and the like can be mentioned, but since the target resin composition is a vinyl chloride-vinyl acetate copolymer composition, use of vinyl chloride is preferred. However, this method is not limited at all. There is no problem if used alone or in combination of two or more. The timing of adding the monomer copolymerizable with vinyl acetate is not particularly limited as long as it is an intermediate stage of the polymerization, and is appropriately determined according to the unreacted vinyl acetate content in the vinyl chloride-vinyl acetate-based copolymer composition. It is possible to choose. The additional amount of the monomer copolymerizable with vinyl acetate can be appropriately selected according to the unreacted vinyl acetate content in the vinyl chloride-vinyl acetate copolymer composition, the reactivity ratio, and the like. .

The unreacted vinyl acetate content in the vinyl chloride-vinyl acetate copolymer composition was determined by gas chromatography.
Can be measured. Measurement conditions such as vaporization chamber, column, detector temperature, type of carrier gas, flow rate, etc. are appropriately determined as long as volatiles and unreacted vinyl acetate in the vinyl chloride-vinyl acetate copolymer composition can be separated. It is necessary to set conditions that can be set, or rather, highly reproducible.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.

Example 1 5 L with stirrer and inlet tube
Was charged with 630 g of vinyl acetate, 1200 g of ethyl acetate and 10.8 g of a radical generator perbutyl O (manufactured by NOF CORPORATION), sealed and pressurized with nitrogen, and then 1170 g of vinyl chloride was charged under reduced pressure. This was kept warm for 40 hours while stirring in a water bath at 60 ° C. to carry out a polymerization reaction.

Further, the autoclave was kept in a water bath at 70 ° C. with stirring for 12 hours, and then toluene 145 was added.
0 g was added and diluted to obtain a vinyl chloride-vinyl acetate copolymer composition. The solid content of this vinyl chloride-vinyl acetate copolymer composition was 40.0% by weight, and the amount of unreacted vinyl acetate by gas chromatography was 0.3% by weight. The vinyl chloride-vinyl acetate copolymer had a chlorine content of 37.2% by weight.

(Method of Measuring Chlorine Content) About 20 mg of a sample dried in advance is collected on a medicine wrapper and folded into a platinum basket. As an absorbent in a combustion flask,
5 ml of 1N KOH and 30 ml of pure water are charged, and oxygen is blown into this as an auxiliary combustion agent. The wrapping paper in the platinum basket is ignited and immediately put into a combustion flask to be burned to decompose the sample, and the generated gas is collected in the absorbent. The absorbing solution is transferred to a beaker, 2 ml of (1 + 1) HNO3 is added, and then a potentiometric titration is performed with 0.0282N AgNO3, and the amount of chlorine in the sample is determined by the following equation.

[0021]

(Equation 1)

C: Chlorine content (% by weight) A: 0.0282N AgNO3 ml required for titration B: Blank 0.0282N AgNO3 ml S: mg of sample F: 0.0282N AgNO3 factor

[0023]

[Table 1]

* 1 Parloyl IPP-50: diisopropyl peroxydicarbonate manufactured by NOF Corporation * 2 HCA: 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10- manufactured by Sanko Chemical Co., Ltd.
oxide

(Examples 2 to 6) The polymerization conditions were changed as shown in Table 1, and the other conditions were the same as in Example 1. Table 1 shows the results.

(Comparative Examples 1 to 3) The polymerization conditions were changed as shown in Table 1, and the other conditions were the same as in Example 1. Table 2 shows the results.

[0027]

[Table 2]

(Evaluation of Storage Stability) To 225 g of each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 and 2, 60 g of talc, 15 g of toluene and 100 g of 1.5 mm glass beads were weighed into a 500 ml polyethylene bottle. After shaking for 3 hours with a paint shaker to disperse the talc, the glass beads were removed by filtration to obtain a paint.

500 g of each of the resin compositions of Examples 1 to 5 and Comparative Examples 1 and 2 was put in a mayonnaise bottle, sealed, and stored in a water bath at 40 ° C. for 2 months. Coating materials were prepared by the same composition and method except that these resin compositions were used.

Each of the resin compositions of Example 6 and Comparative Example 3 was 22
To 5 g, 60 g of talc, 0.5 g of a 10% aqueous solution of sodium polyacrylate and 100 g of 1.5 mm glass beads were added to 5 g.
The talc was weighed in a 00 ml polyethylene bottle and shaken with a paint shaker for 3 hours to disperse the talc, and then the glass beads were removed by filtration to obtain a paint.

Each of the resin compositions of Example 6 and Comparative Example 3 was 50
0 g was sealed in a mayonnaise bottle and stored in a 40 ° C. water bath for 2 months. Coating materials were prepared by the same composition and method except that these resin compositions were used.

These paints were applied to a glass plate with a 1/1000 inch doctor blade, dried at 50 ° C. for 10 minutes, and then measured for their 60 ° surface gloss to evaluate the dispersion of talc.

[0033] The storage stability of the paint is as follows:
Was measured with a B-type viscometer for one week, and at the same time, the state immediately after the coating was formed and the state after one week of heating at 40 ° C. were observed. The results are summarized in Table 1.

In Comparative Examples 1 to 3, the content of unreacted vinyl acetate in the vinyl chloride-vinyl acetate copolymer composition exceeds 1% by weight. On the other hand, in Examples 1 to 6, the unreacted vinyl acetate content was 1% by weight or less.

In each of Comparative Examples 1 to 3, the gloss of the paint film using the resin composition kept at 40 ° C. for 2 months was compared with the gloss of the paint film using the resin composition immediately after production. The decline is significant. On the other hand, in Examples 1 to 6, there was almost no difference between the gloss of the paint film using the resin composition immediately after production and the resin composition kept at 40 ° C. for 2 months.

In each of Comparative Examples 1 to 3, the gloss of the paint film using the resin composition kept at 40 ° C. for 2 months was compared with the gloss of the paint film using the resin composition immediately after production. The decline is significant. On the other hand, in Examples 1 to 6, there was almost no difference between the gloss of the paint film using the resin composition immediately after production and the resin composition kept at 40 ° C. for 2 months.

In all of Comparative Examples 1 to 3, the viscosity of the paint was significantly increased when the paint was kept at 40 ° C. for one week. On the other hand, in Examples 1 to 6, there was almost no difference in viscosity.

[0038]

According to the method for producing a vinyl chloride-vinyl acetate copolymer composition, the content of unreacted vinyl acetate in the composition is controlled to 1% by weight or less. The content of unreacted vinyl acetate in the vinyl copolymer composition is set to 1% by weight or less to eliminate quality variations during and / or after production of paints, adhesives, inks, and the like.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08F 218/08 C08F 218/08 C08L 31/04 C08L 31/04 Z

Claims (5)

[Claims] An unreacted vinyl acetate content of 1% by weight or less, a vinyl chloride-vinyl acetate-based copolymer composition having little deterioration and having stable quality. 2. The method according to claim 1, wherein in the production of the vinyl chloride-vinyl acetate copolymer composition, the polymerization is carried out until the content of unreacted vinyl acetate in the composition becomes 1% by weight or less. A method for producing a vinyl chloride-vinyl acetate copolymer composition. 3. The method according to claim 2, wherein a radical generator is added at an intermediate stage of the polymerization. 4. The radical generator according to claim 3, wherein the radical generator is a reducing agent.
Manufacturing method. 5. The process according to claim 2, wherein vinyl chloride is added at an intermediate stage of the polymerization.