JPH04114043A - Water-resistant composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a composition containing a polysaccharide and having excellent water resistance.

B. Conventional Technology Polysaccharides such as starch are widely used as various binders, adhesives, and surface treatment glues that can be used in the form of aqueous solutions by taking advantage of their properties.

In addition to using the components obtained from raw materials as they are, these polysaccharides have been chemically modified to improve usability, making it easier to obtain aqueous solutions, and increasing the stability of aqueous solutions. Ko.

However, since the chemical modification of molecules in this way tends to increase water solubility, the disadvantage is that water resistance, especially when dried at low temperatures, becomes lower. Various methods have been considered.

The present invention is intended to overcome the drawbacks of water resistance of polysaccharides such as starch derivatives and cellulose derivatives.

The present invention consists of a polyvinyl alcohol (PVA) resin and a polysaccharide (S) obtained by saponifying a polymer (V) having a structural unit represented by the following general formula. It is a water resistant composition.

2II ecHz-CHも○ R3-C-R' (However, R1 represents hydrogen or hydrocarbon, and R2 and R3
represents a hydrocarbon) According to the present invention, it is possible to obtain a composition that is excellent not only in cold water but also in hot water, even when drying or heat-treating at a relatively low temperature.

The PVA resin (V) used in the present invention is a polymer consisting of a structural unit represented by the general formula [I] or other monomer, typically having 1 to 25 carbon atoms, preferably 1 to 20 carbon atoms. vinyl esters of fatty acids, most preferably those obtained by saponifying copolymers with vinyl acetate.

The hydrocarbon groups of R', R' and R3 in general formula: IL include lower alkyl groups such as methyl, ethyl, propyl and butyl, aryl groups such as phenyl, socroalkyl such as nocrohekynyl, and carbon atoms of 1 to 1. 18 hydrocarbon groups are preferred. Specifically, vinyl pivalate, vinyl dialkyl acetate, vinyl trimethylpropylacetate, vinyl vinyl acetate noethylmethyl acetate, vinyl triethyl acetate, vinyl tripropylacetate, vinyl vinyl versatate, vinyl trimethyl acetate, vinyl dimethyl acetate, vinyl diethyl acetate, etc. Examples include vinyl esters having 7-chloroalkyl, such as dialkyl vinyl acetate and methylnochlorohequinyl vinyl acetate.

Among these, vinyl pivalate in which R', R' and R3 are methyl groups is preferred. Therefore, preferred examples include those obtained by saponifying polyvinyl pivalate or a copolymer of vinyl pivalate and vinyl acetate.

In addition, the PVA-based resin used in the present invention (l may contain other monomers such as ethylene, propylene, n-
α-olefins such as butene, isobutyne, 1-hexadecene, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, 2-hydroquinoethyl (meth)acrylate, ( meth)acrylic acid 2
- Ethylhexynol, (meth)acrylic esters such as stearyl (meth)acrylate, (meth)acrylamide, N,N, dimethyl (meth)acrylamide, N-methylol (meth)acrylamide, N-t-butquin (
Amide group-containing monomers such as meth)acrylamide, N-t-octyl(meth)acrylamide, N-vinylpyrrolidone, (meth)acrylic acid, fumaric acid, itaconic acid,
Carphonic acid-containing monomers and their salts such as crotonic acid, maleic acid, and maleic anhydride, and sulfonic acid group-containing monomers such as vinylsulfonic acid, allylsulfonic acid, methalylsulfonic acid, and 2-acrylamido-2-methylpropanesulfonic acid. It is also possible to copolymerize monomers containing quaternary ammonium salts such as monomers and salts thereof, and (meth)acrylamidobropyrotritinylammonium chloride. It is also possible to modify the polymer ends using two chain transfer agents.

The degree of saponification of the PVA resin (V) used in the present invention is 5
It is preferable that the content is 0 mol% or more.

The degree of saponification is selected from the range of 50 to 100 mol%, preferably from 70 to 100 mol%.

If the degree of saponification is lower than 50 mol%, the compatibility with polysaccharides decreases, which is not preferable.

In addition, the degree of polymerization of the polyvinyl alcohol resin is 1
00 to 10,000 is preferred, and 300 to 5,000 is more preferred. [I] When using a copolymer of vinyl pivalate and another monomer such as vinyl acetate, the content of [I] in the copolymer is 0.
．． The content is preferably 5 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more. If the content of the monomer having the structural unit [I] is less than 0.5 mol %, water resistance may deteriorate, which is not preferable.

The polymer containing the structural unit [I] used in the present invention and the P~'A-based resin obtained by saponifying the polymer can be produced by ordinary (co)polymerization methods such as bulk, solution, suspension, and emulsification. and obtained by the usual saponification degree method.

Examples of polysaccharides (S) used in the present invention include starch derivatives such as starch and processed starch, cellulose derivatives such as methylcellulose, ethylcellulose, hydroquinoethylcellulose, hydroquinepropylcellulose, and calfoquine methylcellulose, and alginic acid. Examples include water-soluble polysaccharides such as alginate, pectin, arahiacom, fir gum, locust pea gum, carrageenan, konjac, pullulan, and dextran.

In the composition of the present invention, PVA resin (V) and polysaccharide (
The weight mixing ratio (V/S) with S) is 99/1 to l/99
, preferably 80/20 to 3/97, more preferably *
There are 60/40-5/95 te. Present invention +7) PV
The weight blending ratio of A-based resin (V) and polysaccharide (S) is 1/
If it is less than 99, the water resistance effect will be reduced.

Depending on the intended use, the composition of the present invention may contain solvents, various additives, other water-soluble resins, aqueous polymer dispersions, etc., to the extent that the effects of the present invention are not impaired.

In addition, a salt of boric acid, which reacts with PVA-based resin to obtain an even more water-resistant effect, can also be added.

The composition of the present invention is usually dissolved or dispersed in water or water containing a solvent. This dissolution or dispersion method includes a method of dissolving or dispersing the PVA resin and the polysaccharide at the same time, a method of dissolving or dispersing the PVA resin and then dissolving or dispersing the polysaccharide, or a method of dissolving or dispersing the polysaccharide in the reverse order. A method can be used in which the polysaccharide is dissolved or dispersed in the system ##.

Taking advantage of its water resistance, the composition of the present invention can be used as an inorganic or organic adhesive or binder, as a paint vehicle,
It is effectively used as a treatment agent for inorganic or organic materials, such as a surface coating agent, and is also used for films, sorting, and other applications where water-soluble resins have conventionally been used.

L-LE9 Below, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited in any way by these Examples. In the following, "parts" and "%" mean "parts by weight" and "% by weight", respectively, unless otherwise specified.

Example 1 A reaction vessel equipped with a stirrer was charged with methanol and hinyl pivalate monomer, the system was purged with nitrogen by nitrogen gas bubbling, and polymerization was carried out using 2.2°-azohisisobutyronitrile as an initiator.

The obtained vinyl polypivalate was dissolved in tetrahydrofuran to obtain a solution of vinyl polypivalate in tetrahydrofuran. A methanol solution of potassium hydroxide was added to this solution, thoroughly stirred and held at 606C for 100 minutes, and then acetic acid was added to neutralize the potassium hydroxide. Subsequently, the gel was crushed and dried to obtain a polyvinyl alcohol resin. 10 parts of acetic anhydride and 2 parts of pyrinone were added to 0.5 parts of the obtained polyvinyl alcohol resin, the tube was sealed, and the mixture was heated at 120° C. for 8 hours to acetylate. The obtained r-vinyl niboriacetate was precipitated in n-hexane, and reprecipitation was repeated twice in an acetone-n-hexane system for purification. The obtained 1nivolivinyl alcohol resin is d, -D
When dissolved in MSO and measured by NMR, the degree of saponification was 9.
The content was 24% by mole, and the content was 615%. The viscosity average degree of polymerization determined from [η] of polyvinyl acetate obtained by reacetylation in acetone at 30°C was 2080.

An aqueous solution of a water-resistant composition was prepared by dispersing and dissolving 50 parts of this polyvinyl alcohol and 50 parts of commercially available oxidized starch (Mermaid M-200 manufactured by Shikishima Starch) in water.

This solution was cast and dried at 50'C to form a sheet.

The obtained sheet was immersed in warm water at 40'C for 24 hours, and the state of the sheet-like material was observed. The results are shown in Table 1.

Examples 2 to 5 Vinyl pivalate and vinyl acetate were copolymerized in place of the polyvinyl alcohol resin used in Example 1, and then saponified in the same manner as in Example 1 to produce polyvinyl alcohol resins with different compositions. , and evaluated in the same manner as in Example 1.

The results are also shown in Table 1. The copolymer composition of the polyvinyl alcohol resin was determined from NMR measurements of a copolymer of vinyl pivalate and vinyl acetate before saponification.

In place of the oxidized starch used in IL-9 Example 1, a commercially available cellulose derivative (carboquine methyl cellulose: Daicel C
MC1120) and was evaluated in the same manner as in Example 1. The results are also shown in Table 1.

Evaluation was carried out in the same manner as in Example 1 except that a polyvinyl alcohol resin obtained by saponifying polyvinyl acetate was used in place of the polyvinyl alcohol resin used in Example 1.The results are also shown in Table 1. Shown below.

Comparative Example 4 Evaluation was carried out in the same manner as in Example 6, except that the polyvinyl alcohol resin used in Example 6 was replaced with a polyvinyl alcohol resin obtained by saponifying polyvinyl acetate. The results are also shown in Table 1.

F9 Effects of the Invention The composition of the present invention has extremely high industrial value in that it provides a film with excellent water resistance not only to cold water but also to hot water even when dried or heat treated at a relatively low temperature. .

Patent applicant RiRashi Co., Ltd.

Claims (3)

[Claims] (1) A water-resistant composition comprising a polyvinyl alcohol resin and a polysaccharide obtained by saponifying a polymer having a structural unit [I] represented by the following general formula. [I] ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (However, R^1 represents hydrogen or hydrocarbon, and R^2 and R^3 represent hydrocarbon.) (2) In the structural unit [I] represented by the general formula, R
The water-resistant composition according to claim 1, wherein ^1, R^2 and R^3 are methyl groups. (3) The water-resistant composition according to claim 1 or 2, wherein the polyvinyl alcohol resin has a saponification degree of 50 mol% or more.