JPS6131722B2 - - Google Patents

Description

[Detailed description of the invention]

<Industrial Application Field> The present invention relates to a method for producing an aqueous vinyl chloride/vinyl ester/ethylene copolymer dispersion. More specifically, the present invention relates to a method for producing an aqueous dispersion of vinyl chloride/vinyl ester/ethylene copolymer with improved thermal fluidity. <Conventional technology> Conventionally, aqueous copolymer dispersions of vinyl esters such as vinyl acetate, vinyl chloride, and ethylene have excellent water resistance, alkali resistance, etc., and are used in a wide range of applications such as adhesives, paints, fibers, and paper processing. It is known that it can be used for various purposes. However, such vinyl chloride/vinyl ester/
In an aqueous dispersion of an ethylene copolymer, vinyl chloride/vinyl ester/
When the amount of vinyl chloride copolymer in the ethylene copolymer is increased, the disadvantage is that the molecular weight of the copolymer decreases and the thermal fluidity increases. For example, when an aqueous dispersion of vinyl chloride/vinylethyl/ethylene copolymer is used as an adhesive for a thermoplastic resin and the thermoplastic resin is embossed, the embossed type A problem arises in that misalignment is likely to occur. Furthermore, when used as a vehicle for a paint, if the molecular weight is low, the strength of the paint film will be poor, and for example, the paint film will have the drawback of lacking strength in wash resistance.
Furthermore, when used as a binder for fibers, if the molecular weight is low, the polymer has thermal fluidity, which may cause problems in heat resistance stability. In order to solve such problems, generally a polyfunctional monomer having two or more polymerizable double bonds in the molecule is introduced into a polymer or copolymer,
Methods have been proposed to produce gels that are insoluble in organic solvents by increasing the molecular weight of polymers or copolymers or by cross-linking them. For example, in Japanese Patent Publication No. 52-37012, for the purpose of improving solvent resistance and mechanical properties at high temperatures, vinyl acetate / Ethylene copolymer aqueous dispersions are disclosed. Special Public Service 1977-
Publication No. 19179 states that in an aqueous dispersion of vinyl chloride/vinyl acetate/ethylene copolymer having a vinyl chloride content of 35% by weight or less, divinyl succinate or glycol dimethacrylate is used in a proportion of up to 1% based on the total monomers. There are statements that the molecular weight is increased or cross-links are created. In addition, Japanese Patent Publication No. 42-9671 states that in producing a high degree of polymerization vinyl chloride polymer with low thermal deformability and good processability, saturated hydrocarbon diol divinyl ethers are used in combination with dibasic acid diallyl esters. It is claimed that when used, a vinyl chloride polymer with a high average degree of polymerization can be produced without producing a large amount of gel insoluble in organic solvents. Furthermore, Japanese Patent Publication No. 49-32787 describes unsaturated compounds that can participate in copolymerization in an aqueous dispersion of a copolymer of olefin, vinyl halide, vinyl ester, and/or alkyl acrylate or alkyl methacrylate. Saturated carboxylic acid, acrylonitrile, containing nitrogen unsaturated compounds,
Examples include allyl compounds such as diallyl phthalate and divinyl compounds such as divinylbenzene. <Problems to be Solved by the Invention> However, all polyfunctional monomers having two or more polymerizable double bonds in the molecule increase the molecular weight of the polymer or copolymer, or cause cross-polymerization. It has not been said that it is possible to make a component insoluble in organic solvents by combining them, and even if that purpose is achieved, it may not be possible to obtain a stable aqueous dispersion. It is necessary to carefully consider the selection of a polyfunctional monomer suitable for the type of coalescence or the purpose of modifying the polymer or copolymer, and the method for using it. Under these circumstances, the present inventors have attempted to improve the thermal fluidity of the vinyl chloride/vinyl ester/ethylene copolymer without sacrificing the basic characteristics of the copolymer when the vinyl chloride content is high. As a result of various studies on improvement of strength and strength, we found that in emulsion polymerization under pressure of ethylene, the total amount of vinyl chloride and vinyl ester used in copolymerization
0.1 to 1.0% by weight of dibasic acid diallyl ester represented by the formula [] below is dissolved in vinyl chloride and/or vinyl ester to be subjected to copolymerization, and continuously added to the polymerization system, and copolymerized. If produced by a method in which 60% by weight or more of vinyl chloride and vinyl ester to be subjected to is continuously added to the polymerization system during polymerization, the resulting aqueous copolymer dispersion has remarkable thermal fluidity and strength. The inventors have discovered that the present invention can be improved. The object of the present invention is achieved only under the specific conditions defined above. Conversely, for example, when triallyl cyanurate used in the examples of Japanese Patent Publication No. 52-37012 is used instead of the dibasic acid diallyl ester of the present invention, benzene is Although the desired amount of insoluble matter could be achieved, the resulting aqueous dispersion of the copolymer contained many coarse particles and had poor stability, with a large amount of sediment forming during storage. Further, glycol dimethacrylate or glycol diacrylate described in Japanese Patent Publication No. 46-19179, octadecanediol divinyl ether described in Examples of Japanese Patent Publication No. 42-9671, or triacrylate of a trifunctional monomer, When a trimethacrylate compound is used, within the range of the amount of dibasic acid diallyl ester used in the present invention, not only no benzene insoluble matter but also an increase in molecular weight is observed, and the physical properties of the vinyl chloride/vinyl ester/ethylene copolymer are not observed. The purpose of the improvement was not achieved. Moreover, Japanese Patent Publication No. 49-32789 does not contain any description of the purpose of the present invention and the method of selecting and using polyfunctional monomers to achieve the purpose, and the scope of the contents of the publicly known documents exemplified above is limited. It has become a mere statement. <Means for Solving the Problems> In producing an aqueous dispersion of vinyl chloride/vinyl ester/ethylene copolymer, the present invention involves dispersing ethylene (1 ) 0.1 to 1.0% by weight of the general formula [] based on the total amount of vinyl chloride and vinyl ester to be subjected to copolymerization. (In the formula, R represents a hydrocarbon group having 2 to 10 carbon atoms.) A dibasic acid diallyl ester represented by the following formula is dissolved in vinyl ester and/or vinyl chloride and continuously added to the polymerization system. (2) 20-75% by weight of vinyl chloride, 15-70% by weight of vinyl ester, and 60% by weight or more of the vinyl chloride and vinyl ester to be copolymerized are continuously added to the polymerization system; A method for producing an aqueous vinyl chloride/vinyl ester/ethylene copolymer dispersion having a composition of 5 to 30% by weight of ethylene and a benzene insoluble content of 5 to 60% by weight, and wherein the copolymer is chlorinated. One or more vinyl monomers selected from vinyl monomers having a glycidyl group, an N-methylol group, an alkoxymethyl group, a carboxyl group, or a hydroxyalkyl group in an amount of 10% by weight or less based on the total amount of vinyl ester and ethylene. This invention relates to a method for producing an aqueous dispersion of a copolymerized vinyl chloride/vinyl ester/ethylene copolymer. The present invention will be specifically explained below. The dibasic acid diallyl ester represented by the formula [] used in the present invention is, for example, phthalic acid, isophthalic acid, terephthalic acid, fumaric acid,
These include diallyl esters of dibasic acids such as maleic acid, itaconic acid, succinic acid, and adipic acid. The amount of dibasic acid diallyl ester used in the present invention is 0.1 to 1.0% by weight, preferably 0.2 to 0.8% by weight, based on the total amount of vinyl chloride and vinyl ester to be subjected to emulsion copolymerization. If used within this range, the vinyl chloride/vinyl ester/ethylene copolymer of the present invention contains 5 to 60% by weight, preferably
10-50% by weight of benzene insoluble matter can be produced. In the present invention, if the amount of dibasic acid diallyl ester used is less than 0.1% by weight, only a copolymer with a benzene insoluble content of less than 5% by weight can be obtained, and the physical properties of the copolymer, such as thermal fluidity and strength, can be improved. The objective is not fully achieved. In addition, if the amount used is more than 1.0% by weight, a stable aqueous dispersion cannot be obtained, and moreover, the copolymer will contain more than 60% by weight of benzene-insoluble matter, and such a copolymer may be used as an adhesive, for example. When used as an agent, the processability is poor. Furthermore, in the present invention, in producing an aqueous dispersion of a vinyl/vinyl ester/ethylene copolymer using a dibasic acid diallyl ester as described above, 60% by weight or more of the vinyl chloride and vinyl ester to be subjected to polymerization is polymerized. During the polymerization, the dibasic acid diallyl ester must be dissolved in vinyl chloride and/or vinyl ester and continuously added to the polymerization system during the polymerization. Only then can a copolymer and a stable aqueous dispersion having a uniform copolymer composition and benzene-insoluble matter be obtained. For example, if the dibasic acid diallyl ester is added in its entirety to the polymerization system before the start of the polymerization, or if it is added unevenly during the polymerization, or if it is added without being dissolved in the vinyl chloride and/or vinyl ether, the copolymer Not only is the amount of benzene insoluble content not reproducible, but many coarse particles are produced, resulting in an aqueous dispersion with poor quality. In addition, if more monomers than 40% by weight of the total amount of vinyl chloride and vinyl ester to be subjected to polymerization are supplied to the polymerization system before the start of polymerization, the composition of the copolymer formed in the early stage of polymerization after the start of polymerization The composition of the copolymer produced in the late stage of polymerization differs greatly. In addition, in this case, even if the dibasic acid diallyl ester is added all at once before the start of polymerization, or even if it is dissolved in the monomer added during polymerization, many coarse particles tend to be generated, resulting in an aqueous dispersion with poor stability. A preferred method of the present invention will be explained in more detail. That is, first, less than 40% by weight of the total amount of vinyl chloride and vinyl acetate to be subjected to copolymerization is charged into the polymerization reaction system, and polymerization is started under pressure of ethylene. While continuing the polymerization reaction, the dibasic acid diallyl ester is charged into the polymerization system as uniformly as possible, and in this case, the dibasic acid diallyl ester is dissolved in the vinyl chloride and/or vinyl ester charged during the polymerization reaction. It is preferable to provide Examples of the vinyl ester in the present invention include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl laurate, vinyl tertiary carboxylate, and mixtures thereof, with vinyl acetate being preferred. As the radical polymerization initiator in the present invention,
Radical polymerization initiators generally used in emulsion polymerization can be used, but particularly preferred radical polymerization initiators include so-called redox catalysts consisting of an oxidizing agent and a reducing agent. As the oxidizing agent, for example,
These include hydrogen peroxide, persulfates such as ammonium persulfate, and potassium persulfate, and perborates. Examples of reducing agents include l-ascorbic acid, sodium bisulfite, formaldehyde sodium sulfoxylate dihydrate (trade name: Rongarit), glyoxal sodium bisulfite, and ferrous sulfate. As the emulsifying dispersant in the present invention, various water-soluble polymers are used as protective colloids, or various nonionic surfactants or anionic surfactants are used as emulsifiers, and these are used alone or in combination. Examples of these protective colloids include polyvinyl alcohol, partially saponified polyvinyl alcohol, fibrous derivatives such as methyl cellulose, and hydroxyethyl cellulose. Examples of nonionic surfactants include polyoxyethylene alkyl ethers and polyoxyethylene alkyl phenol ethers such as polyoxyethylene lauryl ether, polyoxyethylene octyl phenol ether, polyoxyethylene nonyl phenol ether, and polyoxyethylene sorbitan monomer. Examples include polyoxyethylene sorbitan resin acid esters such as laurate, polyoxyethylene sorbitan monooleate, and polyoxyethylene polyoxypropylene block copolymers with an added amount of ethylene oxide of 10 to 80%. Examples of anionic emulsifiers include lauryl sulfate, etc. Higher alcohol sulfate salts such as ester soda salts, polyoxyethylene alkyl sulfate soda salts, polyoxyethylene sulfate salts such as polyoxyethylene alkyl phenyl sulfate soda salts, and sodium alkyl sulfosuccinates. Examples include dialkyl sulfosuccinates, alkylbenzene sulfonates, and the like. In addition, in emulsion polymerization, aqueous dispersions are
It is preferable to polymerize while maintaining the pH at 3 to 7 using a pH regulator. Examples of the PH regulator include ammonium bicarbonate, sodium bicarbonate, disodium phosphate, sodium pyrophosphate, sodium acetate, aqueous ammonia, acetic acid, and hydrochloric acid, which may be used alone or in combination of two or more. . The polymerization temperature in the present invention is, for example, 30 to 70
℃ is appropriate, and when the ethylene content of the copolymer of the present invention is 5 to 30% by weight, the polymerization pressure is usually 15℃.
An ethylene pressure of ~150Kg/ ^cm2 is used. In addition, the production method of the present invention can be applied not only to vinyl chloride/vinyl ester/ethylene copolymers, but also to vinyl chloride, vinyl esters, and ethylene.
A so-called reactive monomer copolymerized with a vinyl monomer containing a functional group of less than % by weight/vinyl chloride/
It can also be applied to the production of vinyl ester/ethylene copolymer aqueous dispersions. Examples of the vinyl monomer containing a functional group include vinyl monomers having a glycidyl group such as glycidyl acrylate and glycidyl methacrylate, N-methylolacrylamide, N-
Vinyl monomers having an N-methylol group such as methylolmethacrylamide, or vinyl monomers having an alkoxymethyl group in which the N-methylol group has been replaced with an alkyl ether such as ethyl or butyl ether, acrylic acid, itaconic acid, male

[Table] Next, after purging the reactor with nitrogen and ethylene, 1,643 g of vinyl chloride was charged, ethylene was added, the pressure was made 60 Kg/cm ² , and 8% by weight ammonium persulfate aqueous solution was added to initiate polymerization. The polymerization temperature was adjusted to 50°C. Next, vinyl chloride
A monomer mixture of 4225 g, 4436 g vinyl acetate and 30.1 g diallyl isophthalate was added at a constant rate over 5 hours. When unreacted vinyl acetate decreased to 0.3% after a polymerization time of 7 hours, the reactor was cooled and unreacted ethylene was discharged. The solid content of the obtained vinyl chloride/vinyl acetate/ethylene copolymer aqueous dispersion was 51% by weight, and the amount of coarse particles that could not be filtered through a 100 mesh wire mesh was 13 ppm. It was an aqueous dispersion. The composition of the copolymer was 40% by weight vinyl chloride, 42% by weight vinyl acetate, and 18% by weight ethylene. Furthermore, the benzene-insoluble content of the copolymer was 21% by weight. Example 2 Polymerization was carried out in the same manner as in Example 1, except that 72.2 g of diallyl phthalate was used instead of diallyl isophthalate. The obtained vinyl chloride/vinyl acetate/ethylene copolymer contained 36% by weight of benzene insoluble matter, and as in Example 1, a stable aqueous dispersion containing few coarse particles was obtained. Example 3 The following items were charged into a pressure reactor.

[Table] Next, after purging the reactor with nitrogen and ethylene, 2346 g of vinyl chloride was charged, ethylene was added to make the pressure 45 Kg/cm ² , and 8% by weight ammonium persulfate aqueous solution was added to start polymerization. The temperature was adjusted to ℃. Next, a mixed monomer of 5474 g of vinyl chloride, 2554 g of vinyl acetate, and 72.2 g of diallyl phthalate and 250 g of N-methylolacrylamide were added to 1000 g of water.
Add the dissolved aqueous solution to each of the two supply ports for 5 minutes.
It was fed at a constant rate over time. When unreacted vinyl acetate decreased to 0.3% after a polymerization time of 6.5 hours, the reactor was cooled and unreacted ethylene was discharged. Obtained vinyl chloride/vinyl acetate/ethylene/
The solid content of the aqueous dispersion of the N-methylol acrylamide copolymer was 51.2% by weight, the amount of coarse particles that could not be filtered through a 100-mesh wire mesh was 10 ppm, and the aqueous dispersion was stable and did not produce sediment during standing. Ta. The composition of the copolymer was 60% by weight vinyl chloride, 28% by weight vinyl acetate, 10% by weight ethylene and 2% by weight N-methylolacrylamide. The benzene-insoluble content of the copolymer was 39% by weight. Example 4 The following items were charged into a pressure reactor.

[Table] Next, after purging the reactor with nitrogen and ethylene, 1193 g of vinyl chloride was charged, ethylene was added to increase the pressure to 55 Kg/cm ² , and 8% by weight ammonium persulfate aqueous solution was added to start polymerization. 50℃
I adjusted it so that Next, a mixed monomer of 4,771 g of vinyl chloride, 4,404 g of vinyl acetate, and 55 g of diallyl phthalate and water were added.
2-hydroxyethyl acrylate 260 per 1000g
5 g of dissolved aqueous solution from each of the two supply ports.
It was fed at a constant rate over time. When unreacted vinyl acetate decreased to 0.3% by weight after a polymerization time of 7 hours, it was cooled and unreacted ethylene was discharged. Obtained vinyl chloride/vinyl acetate/ethylene/
The solid content of the aqueous dispersion of the 2-hydroxyethyl acrylate copolymer was 52.6% by weight, and the amount of coarse particles that could not be filtered through a 100-mesh wire mesh was 7 ppm, and it was a stable aqueous dispersion that did not produce sediment during standing. It was hot. The composition of the copolymer was 42% by weight vinyl chloride, 40% by weight vinyl acetate, 16% by weight ethylene and 2% by weight 2-hydroxyethyl acrylate. Furthermore, the benzene-insoluble content of the copolymer was 22% by weight. Comparative Example 1 Polymerization was carried out in the same manner as in Example 1 except that diallyl isophthalate was removed. The resulting copolymer dispersion was a stable aqueous dispersion with few large particles, as in Example 1, but the benzene-insoluble content of the copolymer was 0.6% by weight. Comparative Example 2 Polymerization was carried out in the same manner as in Example 3 except that diallyl phthalate was omitted. The resulting copolymer dispersion was a stable aqueous dispersion with few large particles, similar to Example 3.
The benzene-insoluble content of the copolymer was 1.6% by weight. Comparative Example 3 Polymerization was carried out in the same manner as in Example 1, except that the same amount of triallyl cyanurate was used in place of diallyl isophthalate. Obtained copolymer
Although it had a benzene insoluble content of 16.8% by weight, the aqueous dispersion contained approximately 2000 ppm of large particles that could not be filtered through a 100-mesh wire mesh, and was an aqueous dispersion with poor stability that generated sediment. It was hot. Comparative Examples 4 to 12 Polymerization was carried out in the same manner as in Example 1, except that the polyfunctional monomers shown in Table 1 were used in place of diallyl isophthalate. As shown in Table 1, the aqueous dispersions of the copolymers of Comparative Examples 4 to 12 had no significant difference from Comparative Example 1 in the benzene-insoluble components of the copolymers. Comparative Example 13 In Example 1, the entire amount of vinyl chloride, vinyl acetate and diallyl isophthalate was charged before polymerization,
When polymerization was carried out, the polymerization pressure increased abnormally during the polymerization, and the resulting aqueous dispersion contained many coarse particles and was difficult to filter. Comparative Example 14 1726g charged before starting polymerization in Example 1
Polymerization was carried out in the same manner as in Example 1, except that 30.1 g of diallyl isophthalate was dissolved in vinyl acetate and added before the start of polymerization. Although the benzene-insoluble content of the resulting copolymer was 10% by weight, the resulting aqueous dispersion was difficult to filter and had poor stability as sediment was generated during standing. In addition, to determine the benzene-insoluble content of the copolymers of Examples and Comparative Examples, dissolve 1 g of the copolymer in 100 g of benzene at 70°C for 3 hours, then filter it through a 300-mesh wire mesh, and measure the amount of copolymer that cannot be filtered. It was determined by Reference Example 1 Koka type flow tester (Shimadzu 301
Figure 1 shows the flow curve of the copolymer according to type 1). The measurement conditions were a die diameter of 1 mm, mouth length of 2 mm, 10 minutes of preheating, additional pressure of 10 Kg/cm ² , rising rate of 6°C/
Measurements were carried out from 80°C in minutes. As shown in Figure 1, the fluidity of Examples 1, 2, 3, and 4, which have a benzene-insoluble content in the copolymer, is higher than that of the copolymers of Comparative Examples 1 and 2, which have a small amount of benzene-insoluble content. It exhibits great fluidity even at relatively low temperatures, which is significantly improved. Also, comparative example 4
The flow curves of the copolymers No. 1 to 12 are shown in FIG. 1, and the copolymer fluidity was almost the same as that of Comparative Example 1. Reference Example 2 Using the copolymer aqueous dispersions of Examples 1, 2, and 4 and Comparative Examples 1 and 4, synthetic resin emulsion paints with a pigment volume concentration of 40% were prepared using the paint formulations shown below. Paint formulation (parts: parts by weight) Natrosol 250HR, 2% aqueous solution (hydroxyethyl cellulose) 225 parts Nopco NDW (antifoaming agent) 3 parts Tamol 850 (sodium salt of carboxylated anionic surfactant) 6 parts Emulgen 911 (Polyoxyethylene nonyl ether) 4 parts Monin emulsion 2 parts Texanol 10 parts Ethylene glycol 25 parts Titanium dioxide 150 parts Calcium carbonate 150 parts Kaolin clay 50 parts Water 115 parts Aqueous dispersion of copolymer (solid content 55% by weight) ) 360 parts The wash resistance of the coating films of these paints was tested in accordance with JIS K 5663 for synthetic resin emulsion paints. However, 0.5
2% of polishing sand (commercial cleanser for cleaning) as an accelerated test for more severe conditions instead of 2% of soapy water.
An aqueous solution was used. The test results regarding the wash resistance of the coating film are shown in Table 2, and the synthetic resin emulsion paints using Examples 1, 2, and 4 of the present invention showed excellent wash resistance.
It had excellent coating film strength. Reference Example 3 The aqueous copolymer dispersion of Example 3 and Comparative Example 2 was applied to a soft vinyl chloride resin sheet with a thickness of 0.2 mm.
Apply at a rate of 15g/m ² (solid content), undercoat and dry at 130℃ for 3 minutes, and adhere together with the base fabric (Cotton Aya 9A) through an embossing roll at a roll temperature of 180℃ on the PVC resin sheet side. and produced embossed vinyl chloride leather. The embossed pattern of the vinyl chloride leather manufactured using Example 3 as an adhesive appeared clearly, but the embossed pattern of the vinyl chloride leather manufactured using Comparative Example 2 did not come out clearly. I felt sore. In addition, each of the above PVC leathers is 2.5cm wide.
Table 3 shows the results of the adhesive strength of vinyl chloride leather, which was sampled and measured using an autograph for 180 degree peel strength under normal conditions and during heat-resistant treatment (left at 100°C for 24 hours). As shown in Table 3, the vinyl chloride leather using Comparative Example 2 as an adhesive has inferior strength in normal conditions, especially in heat treatment strength, compared to the vinyl chloride leather using Example 3 as an adhesive. Ta.

【table】

【table】

[Table] <Effects of the invention> Vinyl chloride with improved fluidity according to the invention/
A novel method for producing an aqueous vinyl ester/ethylene copolymer dispersion is provided.

[Brief explanation of the drawing]

The vertical axis is plunger descent amount (15x magnification, mm)
The horizontal axis shows temperature (°C). Curve 1 is Comparative Examples 1 and 4 to 12, Curve 2 is Comparative Example 2, Curve 3 is Example 1 and Example 4, Curve 4
shows the flow curve of each copolymer of Example 2, and curve 5 shows the flow curve of each copolymer of Example 3.

Claims (1)

[Scope of Claims] 1. In producing an aqueous dispersion of vinyl chloride/vinyl ester/ethylene copolymer, in the presence of an emulsifying dispersant and a radical polymerization initiator, under pressure of ethylene, (i) chloride to be subjected to copolymerization; Dibasic acid diallyl ester represented by the following general formula [] in an amount of 0.1 to 1.0% by weight based on the total amount of vinyl and vinyl ester is dissolved in vinyl ester and/or vinyl chloride and continuously added to the polymerization system. (ii) 20-75% by weight of vinyl chloride, 15-70% by weight of vinyl ester, and 60% by weight or more of the vinyl chloride and vinyl ester to be subjected to copolymerization are continuously added to the polymerization system; A method for producing an aqueous vinyl chloride/vinyl ester/ethylene copolymer dispersion having a composition of 5 to 30% by weight of ethylene and a benzene insoluble content of 5 to 60% by weight. (In the formula, R represents a hydrocarbon group having 2 to 10 carbon atoms.) 2 Glycidyl group of 10% by weight or less based on the total amount of vinyl chloride, vinyl ester and ethylene,
Claim 1, characterized in that one or more vinyl monomers selected from vinyl monomers having an N-methylol group, an alkoxymethyl group, a carboxyl group, or a hydroxyalkyl group are copolymerized. A method for producing an aqueous dispersion of