JPS6411067B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel aqueous binder useful in surface treatment or impregnation of paper, cellophane, metal foil, plastic films or sheets, textile products, and the like. Generally, the synthetic resin dispersion used as a binder for the above-mentioned base materials has a treated film that has excellent adhesion, water resistance, oil resistance, heat resistance, and workability, and is also advantageous in terms of cost. be requested. Although vinyl chloride polymers provide treated films with excellent oil resistance, chemical resistance, and mechanical strength, they have poor film-forming properties, poor adhesion to the above-mentioned substrates, and heat sheet properties. Attempts to increase this result in a decrease in tear strength. Although vinyl acetate polymers have excellent film-forming ability and adhesion, they have the drawbacks of poor mechanical strength, alkali resistance, and oil resistance. Therefore, a copolymer of vinyl chloride and vinyl acetate, which has a suitable copolymer composition that brings out the advantages of each of these, has been used as an aqueous dispersion with some success, but it is unsatisfactory due to the following points. That is suitable. First, the adhesion is insufficient. This is attributable to the fact that the copolymer of vinyl chloride and vinyl acetate originally has a low average degree of polymerization, low toughness, and low polarity. It also has poor water resistance. This is due to the use of a large amount of a highly polar general emulsifier to enhance the storage stability of the aqueous dispersion and to promote film forming properties. An even bigger drawback is that the heat resistance is extremely poor. This is attributable to the fact that the average degree of polymerization is small and that it is difficult to provide an elastic crosslinked structure. The inventors of the present invention have conducted intensive studies with the aim of obtaining an aqueous dispersion composition mainly composed of a copolymer of vinyl chloride and vinyl acetate that has a high function as a binder, and have developed the following aqueous dispersion composition. We have discovered a new binder consisting of a composition. That is, the present invention provides the following synthetic resin aqueous dispersion (A) and
Consisting of (B), the ratio of solid content of (A) to solid content of (B) is 98:
2 to 50:50 aqueous binder. (A) (i) Vinyl chloride monomer 15 to 90% by weight, (b) Vinyl acetate monomer 5 to 80% by weight, (c) methallylsulfonic acid or allylsulfonic acid {hereinafter referred to as (meth)allylsulfonic acid 0.1 to 5.0% by weight of the alkali metal salt or ammonium salt of
An aqueous synthetic resin dispersion obtained by emulsion polymerization of a monomer mixture containing 0 to 40% by weight of an ethylene monomer other than (c). (B) A synthetic resin aqueous dispersion obtained by emulsion polymerization of a monomer mixture consisting of 0.5 to 20% by weight of a carboxyl group-containing monomer and 80 to 99.5% by weight of a copolymerizable lipophilic monomer. It is generally advantageous industrially to use the binder as an aqueous dispersion. However, in order to take the form of an aqueous dispersion, it is necessary that the solid material cannot be easily released even when left for a long time or under some adverse mechanical or chemical conditions. Furthermore, it must be possible to obtain a stable aqueous dispersion that is easily dispersible with other compounds such as plasticizers, pigments, metal powders such as magnetic materials, or heat stabilizers. In order to satisfy the above physical properties, (A) (a) vinyl chloride monomer, (b) vinyl acetate monomer and (c) (meth)
An aqueous synthetic resin dispersion obtained by emulsion polymerization using an alkali metal salt or ammonium salt of allylsulfonic acid as an essential monomer, and (B) a monomer consisting of a carboxyl group-containing monomer and other monomers. The present inventors have found that it is sufficient to mix a synthetic resin aqueous dispersion obtained by emulsion polymerization of a mixture of esters and a synthetic resin aqueous dispersion in the above-mentioned predetermined ratio. I understand it as follows. That is, the alkali metal salt or ammonium salt of (meth)allylsulfonic acid present in component (A) is a very polar group, and there is a mutual interaction between this and the carboxyl group present in component (B). It is thought that entanglement occurs, forming an apparent macromolecular structure and imparting toughness. At the same time, since the adhesiveness at the interface can be enhanced by the bipolar group, it is thought that great adhesiveness, water resistance, heat resistance, etc. can be imparted. Next, the usage ratio of each component of the present invention will be explained. (A) The synthetic resin aqueous dispersion must satisfy the following conditions. (a) The amount of vinyl chloride monomer used is 15 to 90% by weight. If the content is less than 15% by weight, the oil resistance or mechanical strength will drop significantly. On the other hand, if it exceeds 90% by weight, film forming properties or adhesion will be poor. (a) A more preferable usage ratio of vinyl chloride monomer is 30 to 80% by weight. In addition, the amount of vinyl acetate monomer (b) used should be 5 to 80% by weight, preferably 15 to 70% by weight, in order to compensate for the disadvantages of the vinyl chloride monomer (a) mentioned above. It is. If the vinyl acetate monomer content is less than 5% by weight, the adhesion of the resulting film will be poor and the
If the weight percentage is exceeded, the mechanical strength of the resulting film,
Alkali resistance and oil resistance become poor. (iii) The amount of the alkali metal salt or ammonium salt of (meth)allylsulfonic acid used should be 0.1 to 5.0% by weight. If the content is less than 0.1% by weight, the adhesion or storage stability will be poor. On the other hand, if it exceeds 5.0% by weight, water resistance will be poor. A more preferable usage ratio is 0.3 to 3.0% by weight. (d) The amount of ethylene monomers other than the above (a), (b), and (c) used is 40% by weight in order to exhibit the interactions of the above (a), (b), and (c). It is necessary not to exceed 20% by weight, and more preferably not to exceed 20% by weight. This (d) monomer may be used as appropriate to adjust the desired physical properties of the resulting synthetic resin aqueous dispersion composition. Generally, the following monomers can be selected to adjust the glass transition temperature, solubility parameter, crosslink density, etc. Examples of acrylic esters include butyl acrylate, 2-ethylhexyl acrylate, ethoxyethyl acrylate, methoxypropyl acrylate, and the like. Examples of the vinyl alkyl ether include pentyl vinyl ether, octyl vinyl ether, lauryl vinyl ether, and cetyl vinyl ether. Examples of vinyl esters of saturated fatty acids include valeric acid vinyl ester, caprylic acid vinyl ester, capric acid vinyl ester, and lauric acid vinyl ester. Examples of monomers containing halogen include vinylidene chloride, vinyl bromide, methallyl chloride, and vinyl chloroacetate. Monomers involved in the crosslinked structure include acrylic acid, methacrylic acid, methacrylic acid glycidyl ester,
Examples include acrylamide and N-methylolacrylamide. On the other hand, the synthetic resin aqueous dispersion (B) must satisfy the following conditions. The amount of carboxyl group-containing monomer used is 0.5 to 20% by weight. If the content is less than 0.5% by weight, no toughness will be imparted through interaction with the alkali metal salt or ammonium salt group of the sulfonic acid contained in the aqueous synthetic resin dispersion of (A), or
If it exceeds 20% by weight, the water resistance of the resulting film will be extremely poor, making each of them unsuitable. The preferred proportion of the monomer used is 0.5 to 15% by weight. Examples of monomers containing carboxyl groups include acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, and crotonic acid. Furthermore, anhydrides or acid chlorides of these unsaturated acids can be equally used to easily form carboxyl groups in water. Further, the other monomer is a monomer copolymerizable with the above-mentioned carboxyl group-containing monomer, and the amount used is 80 to 99.5% by weight, preferably 85 to 99.5% by weight. If it is less than 80% by weight, the water resistance of the resulting coating will be extremely poor, and if it exceeds 99.5% by weight, the resulting coating will lose its toughness, making it unsuitable. Other monomers used include lipophilic monomers such as methyl methacrylate, methyl acrylate, acrylonitrile, methacrylonitrile, vinylidene chloride, 2-ethylhexyl acrylate, styrene, ethyl acrylate, butyl acrylate, and butadiene. Examples of the synthetic resin aqueous dispersion (B) include synthetic rubber emulsions, vinylidene halide emulsions, methacrylic acid ester emulsions, and styrene emulsions, each of which has excellent film-forming properties and flame retardancy. , or used as appropriate to impart heat resistance. In particular, a synthetic resin emulsion having good compatibility with the copolymer of vinyl chloride and vinyl acetate is suitable.
Examples of such synthetic resin emulsions include emulsions of acrylic ester/acrylonitrile, methyl methacrylate/acrylic ester, styrene/acrylonitrile, butadiene/acrylonitrile, and polyurethane synthetic resins. The ratio of the solid content of the aqueous synthetic resin dispersion (A) to the solid content of the aqueous synthetic resin dispersion (B) is from 98:2 to 50:50, more preferably from 90:10 to 60:40. If the former ratio is smaller than this range, the above-mentioned properties of the basic vinyl chloride/vinyl acetate copolymer cannot be exhibited, and conversely, if it is larger than this range, the toughness necessary for the function as a binder is insufficient. It becomes insufficient. The aqueous synthetic resin dispersion (A) used in the method of the present invention is produced by copolymerizing the aforementioned monomers by emulsion polymerization. Dispersants or emulsifiers used in this case include, for example, dispersants such as alkyl cellulose, hydroxyalkyl cellulose, gelatin, alkylaryl sulfonates, alkyl sulfates, polyoxyethylene alkylaryl ethers, polyoxyethylene aryl sulfates, Emulsifiers such as sulfosuccinate alkali salts can be used as appropriate. As a catalyst, potassium persulfate, ammonium persulfate,
Water-soluble compounds such as hydrogen peroxide, oil-soluble compounds such as benzoyl peroxide, azobisisobutyronitrile, di-2-ethylhexyl peroxydicarbonate, and lauroyl peroxide are selected as appropriate depending on the intended polymerization method. It can be used. On the other hand, as the synthetic resin aqueous dispersion [B], an emulsion obtained by a conventional emulsion polymerization method or a hydrosol type emulsion having self-emulsifying properties can be used. The method for blending the synthetic resin aqueous dispersions [A] and [B] is to mix them sufficiently under stirring.
In some cases, a method of stirring under heating is preferred. The following various additives can be added to the synthetic resin aqueous dispersion composed of [A] and [B] blended in this way. Examples of the plasticizer include epoxidized soybean oil, epoxidized linseed oil, dibutyl phthalate, and diisodecyl phthalate. Also, as a crosslinking aid,
polyethyleneimine, polyacrylamide, etc.
Amine-based or amide-based compounds can be used. According to the present invention, each of the advantages of vinyl chloride resin and vinyl acetate resin, namely, excellent adhesiveness, water resistance,
A water-based binder having important properties such as heat resistance, mechanical strength, oil resistance, tear strength and film-forming properties can be easily obtained, especially by using the synthetic resin aqueous dispersion [A] and [B] in combination. [A], [B] The toughness of the resulting film is significantly increased compared to the case of each alone,
It is particularly useful for substrates such as paper, cellophane, metal foil, plastic film, and textiles. Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. The evaluation method for physical properties in each example is as follows. (1) Heat seal strength Synthetic resin emulsion is uniformly applied to a Tetron/cotton (65/35) blended fabric, with a solid content of 17 to 20 gr/
m ² and then combined with vinyl chloride soft leather, heat-sealed under the conditions of 150° C. x 5 Kg/cm ² x 10 seconds, and the peel strength was measured at a width of 20 m/m. (2) Tear strength A cut was made in the test base material (thickness 0.8 to 1.0 m/m) prepared for measuring heat seal strength.
We looked at the strength when torn at 180°. (The value was calculated by dividing the load by the thickness.) (3) Heat-sealing strength during heating The test base material prepared for measuring heat-sealing strength was left at 80℃ for 5 minutes, then kept warm. Peel strength was measured in the same manner as in (1) for measuring heat seal strength. (4) Water resistance After immersing the test base material prepared for heat seal strength measurement in pure water at 20℃ for 3 days, the peel strength was measured, and the peel strength was divided by the strength before immersion. The retention rate was calculated. Examples 1 to 7 and Comparative Examples 1 to 3 140 parts by weight of pure water was added to the stainless steel polymerization vessel of 5.
100 as the total monomer under the conditions of the monomer composition in Table 1.
Part by weight, PVA-217 as a dispersant (average degree of polymerization;
1730, degree of saponification: 88 mol%, 0.7 parts by weight (manufactured by Kuraray Co., Ltd.), and Lebenol WZ (anionic emulsifier,
(manufactured by Kao Atlas Co., Ltd.) and 0.3 parts by weight of potassium persulfate as a catalyst.
pm for 30 minutes, after pre-stirring 60℃ x 300rpm x
Polymerization was carried out for 20 hours to obtain an emulsion with a solid content of 42% by weight. This was used as the synthetic resin aqueous dispersion (A). On the other hand, as the synthetic resin aqueous dispersion [B], those listed in Table 1 were used, and after stirring both thoroughly at room temperature,
A synthetic resin aqueous binder was obtained. This aqueous binder was applied to a base material using a blade coater, and each of the above tests was conducted. The evaluation results of these physical properties are also listed in Table 1. 【table】

Claims (1)

[Scope of Claims] 1. Consisting of the following synthetic resin aqueous dispersion (A) and (B), the ratio of solid content of (A) to solid content of (B) is 98:2 to 98:2.
50:50 water-based binder. (A) (i) Vinyl chloride monomer 15-90% by weight, (b) Vinyl acetate monomer 5-80% by weight, (c) alkali metal salt or ammonium salt of methallylsulfonic acid or allylsulfonic acid 0.1 ~5.0% by weight, (d) above (a),
An aqueous synthetic resin dispersion obtained by emulsion polymerization of a monomer mixture containing 0 to 40% by weight of ethylene monomers other than (b) and (c). (B) A synthetic resin aqueous dispersion obtained by emulsion polymerization of a monomer mixture consisting of 0.5 to 20% by weight of a carboxyl group-containing monomer and 80 to 99.5% by weight of a copolymerizable lipophilic monomer.