JPS6120586B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyvinyl alcohol resin composition with improved viscosity. Aqueous solutions of polyvinyl alcohol resins are useful in a variety of applications, including label glue, office glue, and glue for interleaf paper, bag making, and paper containers. However, if a polyvinyl alcohol resin aqueous solution is left for several days, the surface will peel, and if applied to paper, the glue may penetrate too much into the paper, causing poor lamination, and the threadability is extremely poor. In addition, because of its poor thixotropic properties, there are various problems such as poor machine coating workability and large sagging after coating. Therefore, it has been proposed to add carboxymethyl cellulose, polyethylene oxide, sodium polyacrylate, etc. to a polyvinyl alcohol resin aqueous solution as a thickener or thixotrovitic property improver, but the addition of carboxymethyl cellulose itself has antiseptic and antifungal properties. This causes problems such as a decrease in viscosity and the tendency for mold to grow.Also, under acidic conditions, the solubility decreases and becomes a gel state, and under alkaline conditions, the viscosity decreases significantly. Addition of polyethylene oxide has poor compatibility with polyvinyl alcohol-based resins, so its uses are severely limited, and addition of sodium polyacrylate has a poor thickening effect. However, as a result of intensive research by the present inventors,
Add 100 parts by weight of polyvinyl alcohol resin (A) to polyalcohol polyvalent allyl ether-unsaturated carboxylic acid compound copolymer or polyalcohol polyvalent methallyl ether-unsaturated carboxylic acid compound copolymer (hereinafter referred to as polyalcohol polyvalent (meth) ) allyl ether unsaturated carboxylic acid compound copolymer) (B)
The composition containing 0.1 to 30 parts by weight is highly effective in preventing skin burrs, improving suitability for machine coating, imparting thixotropic properties, imparting thickening properties, preventing stringiness, preventing sagging, and has antiseptic and antifungal properties. The present inventors have discovered that it exhibits various properties such as good chemical properties and stability against acids and alkalis, leading to the completion of the present invention. The remarkable effects of the present invention are first seen when the polyalcohol polyvalent metaallyl ether-unsaturated carboxylic acid compound copolymer (B) is added to the polyvinyl alcohol resin (A), and the (B) component Even if polyacrylic acid or a salt thereof is used instead, such an effect cannot be achieved at all. For example, to give a specific example of the viscosity increasing effect, the degree of polymerization is 1800,
15% of polyvinyl alcohol with saponification degree of 88 mol%
The aqueous solution has a viscosity of 7900 cps (2 rpm) at a temperature of 30°C, and 0.45 parts by weight of allyl sucrose (5.6 allyl groups per molecule) is added to 100 parts by weight of this aqueous solution.
When sodium acrylate (weight ratio 3:97) copolymer is added, the viscosity instantly increases to 82,000 cps (2 rpm). Note that even if 0.45 parts by weight of the above allyl sucrose-sodium acrylate copolymer is added to 100 parts by weight of water at a temperature of 30°C, the viscosity becomes only 8000 cps (2 rpm).
Further, when 0.45 parts by weight of sodium polyacrylate is added to 100 parts by weight of the polyvinyl alcohol aqueous solution, the viscosity is 9000 cps (2 rpm), and even when 30 parts by weight is added, the viscosity is only 20000 cps (2 rpm). The 7% aqueous solution of polyvinyl alcohol has a viscosity of 210 cps, and if a container containing this aqueous solution is overturned, the aqueous solution will immediately flow out. But this 7
When 10% of the above allyl sucrose-sodium acrylate copolymer based on polyvinyl alcohol is added to a % aqueous solution, the viscosity becomes 54,800 at 20 rpm and 230,000 at 2 rpm.
Even if the container is turned upside down, the contents will not spill out. However, the coating properties are good, and since there is little permeability when applied to paper, the lamination properties are extremely good. To give another example, the degree of polymerization is 1700, and the degree of saponification is 96.0.
The viscosity of a 15% aqueous solution of mol% polyvinyl alcohol is 6200 cps (2 rpm) at a temperature of 30°C;
5270 cps (20 rpm), but 3% of polyvinyl alcohol is added to 100 parts by weight of this aqueous solution, i.e.
0.45 parts by weight of allyl sucrose (allyl group per molecule)
5.6 pieces) - acrylic acid copolymer (weight ratio 3:97) When the copolymer is added, the viscosity is actually 833,000 cps
(2rpm), dramatically increases to 276000cps (20rpm). However, in 100 parts by weight of water at a temperature of 30°C, the above allyl sucrose-
Even if 0.45 parts by weight of acrylic acid copolymer is added, the viscosity will be no more than 15 cps. Polyvinyl alcohol resin (A) in the present invention
This refers to partially or completely saponified vinyl ester polymers or copolymers, or subsequently modified products. For example, (a) about 50 to 100 polyvinyl acetate
Mol% saponified polyvinyl alcohol, (b) mainly consisting of vinyl acetate, and other copolymerizable monomers such as olefins (ethylene, propylene, α-butene, α-octene, α-dodecene,
α-octadecene, etc.), unsaturated monocarboxylic acids (acrylic acid, methacrylic acid, crotonic acid, etc.)
or esters or salts thereof, unsaturated polycarboxylic acids (maleic acid, fumaric acid, itaconic acid, etc.) or partial or complete esters or salts or anhydrides thereof), unsaturated sulfonic acids (ethylene sulfonic acid, allyl sulfonic acid, etc.) , methalylsulfonic acid, etc.) or their salts, amides (acrylamide, methacrylamide, etc.), nitriles (acrylonitrile, methacrylonitrile, etc.), vinyl ether, vinyl ketone, vinyl chloride, etc. as part of the vinyl acetate component of copolymers. or completely saponified (the proportion of other copolymerizable monomers is
50 mol% or less, especially 20 mol% or less. However, when ethylene is used as a comonomer, the ethylene content may be up to about 95 mol%. ), (c) above
Examples include acetalization, urethanization, phosphoric acid esterification, cyanoethylation of (a) and (b), and modified products after grafting vinyl monomers. The polyalcohol polyvalent metaallyl ether of the polyalcohol polyvalent metaallyl ether-unsaturated carboxylic acid compound copolymer (B) is a dihydric polyalcohol having two or more, preferably three or more, hydroxyl groups in one molecule. Refers to the above allyl ether or methallyl ether. Polyalcohols include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol,
Trimethylolpropane, 1,2,3-butanetriol, glycerin, diglycerin, 3-methylpentane-1,3,5-triol, 2,3,
4-trihydroxybutyric acid, aldotetrose, ketotetrose, aldopentose, ketopentose, aldohexose, ketohexose, sucrose,
Maltose, lactose, raffinose, hexozane, pentozan, galactomanan, glucomanan, starch, pentaerythritol, dipentaerythritol, tripentaerythritol, arabitol, marnitol, iditol, tritol, sorbitol, inositol, duulcitol, etc., or reduced derivatives thereof, such as mono and dicarboxylic sugar acids.
Among these, oligosaccharides, that is, sugars, reduction products of sugars (alcohols, keto alcohols, alkoxy alcohols, etc.), and oxidation products of sugars (sugar acids, keto acids, aldo acids, etc.) are preferable. Examples include glucose, galactose, fructose, sorbose, rhamnose, sucrose, arabinose, maltose, lactose, and raffinose. Allyl etherification or methallyl etherification of a polyalcohol as described above can be obtained, for example, by reacting the polyalcohol with an allyl halide, a methallyl halide, or a mixture thereof under strongly alkaline conditions. Next, as unsaturated carboxylic acid compounds, acrylic acid, methacrylic acid, α-chloroacrylic acid, α-
Cyanoacrylic acid, crotonic acid, sorbic acid, itaconic acid, citraconic acid, mesaconic acid, muconic acid, glutaconic acid, aconitic acid, cinnamic acid, α-
Examples include phenyl acrylic acid, maleic acid, and fumaric acid. These salts may be used, and in the case of polyvalents, anhydrides or partial alkyl esters may be used. The inclusion of other comonomers in addition to the monomers of polyalcohol polyhydric metaallyl ether and unsaturated carboxylic acid compound does not pose any particular problem. Examples of such comonomers include styrenic monomers, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, acrylic esters, methacrylic esters, vinyl esters, vinyl ethers, vinyl ketones, vinyl chloride, vinylidene chloride, vinylpyrrolidone, ethylene, alpha -Olefins, maleic acid diesters, etc. Polyalcohol polyvalent (meth)allyl ether
The content of polyalcohol poly(meth)allyl ether in the unsaturated carboxylic acid compound copolymer is 0.01~
It is selected from the range of 30% by weight, but in reality it is 0.01 to 10
% by weight is sufficient. If the content is too small, the viscosity of the polyvinyl alcohol resin cannot be improved, while if the amount is too large, the viscosity of the polyvinyl alcohol resin cannot be improved because it loses its affinity for water. It disappears. On the other hand, the content of the unsaturated carboxylic acid compound in the copolymer may be at least 25% by weight, preferably at least 40% by weight, and the remainder can be supplemented by other comonomers as mentioned above. If the content of the unsaturated carboxylic acid compound is less than 25% by weight, the affinity with the polyvinyl alcohol resin will decrease, and the effect of improving the viscosity of the aqueous solution will therefore be significantly impaired. Next, the amount of the polyalcohol polyvalent (meth)allyl ether-unsaturated carboxylic acid compound copolymer (B) based on 100 parts by weight of the polyvinyl alcohol resin (A) is selected from the range of 0.1 to 30 parts by weight, and 0.1 If it is less than 30 parts by weight, the modification effect will be insufficient, while if it exceeds 30 parts by weight, the modification effect will reach its upper limit, and the effect of increasing the amount will not increase beyond a certain level, and workability such as dissolution will be difficult. Become. Any method of blending (A) and (B) can be used, including adding (B) to the powder of (A) or blending (B) into an aqueous solution of (A). . Suitable additives such as other water-soluble polymers, colorants, fillers, antifoaming agents, and foaming agents may be added to the composition of the present invention, if necessary. The composition of the present invention can be used as an aqueous solution with a concentration of several percent to about 25%, as a glue for labels, an office glue, an industrial glue for cardboard, interleaving paper, bag making, paper containers, etc., a fiber wall material binder, and a sand wall material binder. , temporary protective film, ceramic glaze binder, water-based coating material binder,
It is used for a variety of purposes, such as adding printing ink and filling liquid for sample bottles of Western alcoholic beverages. Next, the composition of the present invention will be further explained by giving an example. Hereinafter, "parts" and "%" are expressed on a weight basis unless otherwise specified. Examples 1 to 25, Control Examples 1 to 20 Polyvinyl alcohol resin used (A) A-1 Polyvinyl alcohol with a degree of polymerization of 1800 and a degree of saponification of 88.0 mol% A-2 Polyvinyl alcohol with a degree of polymerization of 500 and a degree of saponification of 88.0 mol% A-3 Polyvinyl alcohol with a polymerization degree of 1700 and a saponification degree of 96.0 mol% A-4 Obtained by saponifying 94.1 mol% of the vinyl acetate component of a monomethyl maleate-vinyl acetate copolymer with a monomethyl maleate content of 2.2 mol%. Degree of polymerization: 1700
Monomethyl maleate-modified polyvinyl alcohol
Allylsulfonic acid sodium modified polyvinyl alcohol with a polymerization degree of 250 obtained by saponifying 98.0 mol% A-6 Polyvinyl alcohol with a polymerization degree of 800 and a saponification degree of 99.2 mol% Polyalcohol used polyvalent (meth)allyl ether - unsaturated Carboxylic acid compound copolymer (B) B-1 Acrylic acid-allyl sucrose (weight ratio
97:3) copolymer, however, the number of allyl groups in one molecule of allyl sucrose is 5.6 B-2 Acrylic acid-allyl pentaerythritol (weight ratio 93:7) copolymer, however, the number of allyl groups in one molecule of allyl pentaerythritol is 2.8 B-3 Acrylic acid. Allyl sorbitol (weight ratio 95:5) copolymer, however, the number of allyl groups in one molecule of allyl sorbitol is 4.7 B-4 Sodium acrylate-allyl sucrose copolymer prepared by neutralizing the copolymer of B-1 with sodium hydroxide Polymer B-5 Ammonium acrylate-allyl sucrose copolymer obtained by neutralizing the copolymer of B-1 with aqueous ammonia B-6 Methacrylic acid-styrene-allyl sucrose (weight ratio 43:56:1) copolymer , however, the allyl group in one molecule of allyl sucrose is
5.2 pieces B-7 Acrylic acid-vinyl acetate-allyl sucrose (weight ratio 75:23.5:1.5) copolymer, however, 5.8 allyl groups in one molecule of allyl sucrose B-8 Maleic anhydride-vinyl n-butyl ether-methallyl Sucrose (weight ratio 50:
49.5:0.5) Copolymer, however, 5.5 methallyl groups in one molecule of methallyl sucrose B' Sodium polyacrylate as a control example Add the above (B) to the aqueous solution of the above (A) at a temperature of 95°C for 2 hours The mixture was heated and stirred uniformly, and the viscosity was measured at a rotation speed of 2 rpm and 20 rpm at a temperature of 30° C., and the thixotropic index was determined from the ratio. In addition, the peeling properties, permeability (pot life on medium-quality paper), and sagging properties were also measured. The results are shown in the table below.

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Claims (1)

[Scope of Claims] 1 100 parts by weight of polyvinyl alcohol resin (A) and polyalcohol polyvalent allyl ether unsaturated carboxylic acid compound copolymer or polyalcohol polyvalent methallyl ether-unsaturated carboxylic acid compound copolymer (B )0.1 to 30 parts by weight of a polyvinyl alcohol resin composition. 2. The composition according to claim 1, wherein the content of polyalcohol polyallyl ether or polyalcohol polyvalent methallyl ether in the copolymer (B) is 0.01 to 10% by weight.