JP2003147144A - Aqueous composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous composition which excels in water resistance and does not discolor with time. SOLUTION: The aqueous composition comprises (A) a vinyl alcohol based polymer containing 0.1-10 mol% monomer unit having an amino group in the molecule and having a saponification degree of >=70 mol% and (B) a water- resisting agent, and has a pH of its aqueous solution of 2.5-7.5.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to aqueous compositions. Specifically, it relates to an aqueous composition having excellent water resistance and free from coloration over time.

[0002]

2. Description of the Related Art Conventionally, vinyl alcohol-based polymers (hereinafter, vinyl alcohol-based polymers may be abbreviated as PVA) have been widely used as various binders, adhesives or surface treatment agents. Are known to have excellent performance that cannot be followed by other water-soluble resins. However, since PVA is water-soluble, it has a drawback that it has low water resistance, particularly when it is dried at a low temperature, and various methods have been studied so far in order to improve this drawback. For example, as a method for improving the water resistance of PVA, a method of crosslinking PVA with glyoxal, glutaraldehyde or dialdehyde starch, a water-soluble epoxy compound, a methylol compound, etc. is known. However, in order to make PVA sufficiently water resistant by this method, it is necessary to heat-treat PVA at a high temperature of 100 ° C. or higher, particularly 120 ° C. or higher for a long time. Also, in order to make PVA water resistant without heat treatment at high temperature, pva solution is added
There is also known a method in which a strong acidic condition of H2 or less is used, but this method has problems such as poor viscosity stability of an aqueous solution of PVA, gelation during use, and insufficient water resistance of PVA. There is a drawback that Furthermore, a method of crosslinking a carboxylic acid-containing PVA with a polyamide epichlorohydrin resin and a method of crosslinking an acetoacetyl group-containing PVA with a polyvalent aldehyde compound such as glyoxal are known, but even with these methods, the water resistance of PVA is insufficient. Therefore, there are problems such as poor viscosity stability of the PVA aqueous solution. In JP-A-9-272389 (USP 5,900,463), a composition using PVA having an amino group bonded to a phenyl group was proposed, and the water resistance of PVA was significantly improved. However, the PVA has a problem that it is not suitable for use in some applications because it is colored over time when left in a film or aqueous solution state for a long time.

[0003]

SUMMARY OF THE INVENTION Under these circumstances, it is an object of the present invention to provide an aqueous composition which has excellent water resistance and is free from coloration over time.

[0004]

Means for Solving the Problems As a result of intensive studies to develop an aqueous composition having the above-mentioned preferable properties, the present inventors have found that a monomer unit having an amino acid group in the molecule is 0.1. An aqueous composition containing 10 to 10 mol% of a vinyl alcohol polymer (A) having a saponification degree of 70 mol% or more and a waterproofing agent (B), and having an aqueous solution pH of 2.5 to 7.5. The present invention has been completed by finding that the product satisfies the purpose.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.

In the aqueous composition of the present invention, a vinyl alcohol polymer (A) containing an amino acid group in the molecule
(Hereinafter, this may be abbreviated as an amino acid group-containing PVA polymer (A)) is 0.1 to 10 mol%, preferably 0.3 to 8 mol% of a monomer unit having an amino acid group.
contains. When the amount of the monomer unit having an amino acid group is less than 0.1 mol%, the effect of introducing the functional group is not sufficiently exhibited, and when the amount exceeds 10 mol%, the amino acid group-containing PVA
The polymerization rate of emulsion polymerization using a polymer as a dispersant decreases, and the polymerization is delayed. The saponification degree of the amino acid group-containing PVA polymer (A) is 70 mol% or more, preferably 80 to
It is 99 mol%, and more preferably 85 to 98 mol%. The degree of polymerization of the amino acid group-containing PVA polymer (A) is not particularly limited, but is usually 100 to 8,000, preferably 200 to 5,000.

The amino acid group-containing PVA polymer (A) is
Excluding the monomer unit having an amino acid group, it is substantially composed of vinyl alcohol units or vinyl alcohol units and vinyl ester units. Here, as the vinyl ester, vinyl formate, vinyl acetate, vinyl propionate, vinyl pivalate, vinyl trifluoroacetate, 2-
Examples include monomers such as vinyl ethylhexanoate, which is usually vinyl acetate.

The amino acid group-containing PVA polymer (A) is
Unless the effects of the present invention are impaired, vinyl ester units,
You may have 1 or more types of monomer units other than the vinyl alcohol unit and the monomer unit which has an amino acid group.
Examples of such monomer units include olefins such as ethylene, propylene and isobutylene; halogenated olefins such as vinyl chloride, vinyl bromide, vinyl fluoride, vinylidene chloride, vinylidene fluoride and tetrafluoroethylene; methyl acrylate, Acrylic esters such as ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, dodecyl acrylate, 2-hydroxyethyl acrylate; methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, methacrylic acid Methacrylic acid esters such as dodecyl and 2-hydroxyethyl methacrylate; acrylamide monomers such as acrylamide and N, N-dimethylacrylamide; methacrylamide, N, N-dimethylmethacrylamide. Methacrylamide-based monomers; N
-Vinylpyrrolidone; acrylonitrile, methacrylonitrile; styrene-based monomers such as styrene and α-methylstyrene; acrylic acid, methacrylic acid, (anhydrous) fumaric acid, (anhydrous) maleic acid, (anhydrous) itaconic acid, etc. (Anhydrous) carboxylic acid group-containing monomer; allylsulfonic acid, methallylsulfonic acid, vinylsulfonic acid, acrylamido-2-methylpropanesulfonic acid, methacrylamide-2-methylpropanesulfonic acid, sulfopropyl acrylate, methacrylic acid Monomers having sulfonic acid groups such as sulfopropyl and p-styrenesulfonic acid and their sodium or potassium salts; Monomers having amino groups such as dimethylaminoethyl acrylate and dimethylaminoethyl methacrylate and quaternary compounds thereof ; Ethyl vinyl ether, Vinyl ether monomers such as vinyl ether; butadiene, isoprene, and a monomer unit, such as diene monomers such as chloroprene. Further, the amino acid group-containing PVA-based polymer has a functional group at the terminal obtained by polymerizing a vinyl ester-based monomer such as vinyl acetate in the presence of a thiol compound such as thiolacetic acid and mercaptopropionic acid. You may have one.

The amino acid group-containing PVA polymer (A) can be obtained by various methods. The production method is (1) copolymerizing a monomer having an epoxy group such as allyl glycidyl ether and a vinyl ester monomer such as vinyl acetate to obtain a vinyl ester polymer having an epoxy group in a side chain. The amino acid group was introduced into the side chain of the polymer by producing and further performing an addition reaction between the epoxy group existing in the side chain of the polymer and the thiol compound having the amino acid group using NaOH or the like as a catalyst. Then, a method of saponifying the polymer, (2) a method of reacting a vinyl alcohol-based polymer with a compound having a functional group capable of reacting with a hydroxyl group of the vinyl alcohol-based polymer and an amino acid group, and the like can be mentioned. Among them, industrial availability and cost of a compound having a functional group used for introducing an amino acid group,
In addition, considering the yield of the functional group introduction reaction and the like, the production method (1) is preferable.

In the production method (1), as the monomer having an epoxy group, allyl glycidyl ether, methallyl glycidyl ether, 1,2-epoxy-
5-hexene, 1,2-epoxy-7-octene, 1,
2-epoxy-9-decene, 8-hydroxy-6,7-
Epoxy-1-octene, 8-acetoxy-6,7-epoxy-1-octene, N- (2,3-epoxy) propylacrylamide, N- (2,3-epoxy) propylmethacrylamide, 4-acrylamidophenylglycidyl Ether, 3-acrylamidophenyl glycidyl ether, 4-methacrylamidophenyl glycidyl ether, 3-methacrylamidophenyl glycidyl ether, N-glycidoxymethyl acrylamide, N-
Glycidoxymethylmethacrylamide, N-glycidoxyethylacrylamide, N-glycidoxyethylmethacrylamide, N-glycidoxypropylacrylamide, N-glycidoxypropylmethacrylamide, N-
Glycidoxy butyl acrylamide, N-glycidoxy butyl methacrylamide, 4-acrylamidomethyl-
2,5-dimethyl-phenyl glycidyl ether, 4-
Methacrylamidomethyl-2,5-dimethyl-phenylglycidyl ether, acrylamidopropyldimethyl (2,3-epoxy) propylammonium chloride,
Methacrylamidopropyldimethyl (2,3-epoxy) propylammonium chloride, glycidyl methacrylate, etc. are used.

In the production method (1), examples of the thiol compound having an amino acid group include cysteine, penicylamine, glutathione, N-methylcysteine, N, N-dimethylcysteine and the like.
Further, salts of these compounds, ester derivatives such as acetic acid ester and benzoic acid ester, and thioester derivatives can also be used.

In the above production method (1), the reaction between the thiol group or thioester group and the epoxy group is carried out without solvent or in a solvent for dissolving or swelling the compound having a thiol group or thioester group and the compound having an epoxy group. Is carried out in. Such solvents include methanol, ethanol, n-propanol,
Alcohols such as n-butanol; aromatics such as benzene, toluene and xylene; ethers such as tetrahydrofuran, dioxane and diethyl ether; hydrocarbons such as n-hexane. These solvents may be used alone or in combination with 2 Used as a mixture of two or more species. The reaction conditions differ depending on the structure of the compound having an epoxy group or the structure of the compound having a thiol group or a thioester group, but usually when a solvent is used, a polymer concentration is 5 to 90%, a thiol group or a thioester group / epoxy. Group = 1.0 to 5.0 (molar ratio), reaction temperature 0 to 25
The reaction time is 0 ° C and the reaction time is 0.01 to 20 hours. Here, in the case of reacting a thiol group with an epoxy group, tertiary amines such as triethylamine and pyridine; phosphines such as tributylphosphine and triphenylphosphine;
Alkali metal hydroxides such as sodium hydroxide; When a basic compound such as tetraethylammonium hydroxide or sodium methoxide reacts with a thioester group and an epoxy group, tributylammonium chloride, tributylammonium bromide or other 4 The primary ammonium salts are effective as reaction catalysts.
Further, in order to prevent the oxidation of the thiol group, the reaction system may be degassed or replaced with nitrogen, or an antioxidant or the like may be added.

In the production method of the above (1), when the saponification reaction of the vinyl ester polymer is carried out after the reaction between the thiol group or the thioester group and the epoxy group, the usual saponification of the vinyl ester polymer is carried out. The saponification reaction using the basic catalyst or acid catalyst used can be directly applied. That is, sodium hydroxide, potassium hydroxide,
A saponification reaction using a basic catalyst such as sodium methoxide or an acidic catalyst such as p-toluenesulfonic acid and an alcohol such as methanol, ethanol, propanol or butanol or a glycol such as ethylene glycol as a solvent can be applied. . Here, as the solvent for the saponification reaction, in order to improve the solubility of the vinyl ester polymer or the catalyst, a solvent such as tetrahydrofuran, dioxane, dimethylsulfoxide, diethylene glycol dimethyl ether, toluene, acetone, or water is appropriately mixed. May be. The conditions for the saponification reaction are appropriately adjusted depending on the structure of the vinyl ester polymer used and the degree of saponification of the intended vinyl alcohol polymer, but usually the saponification reaction catalyst / vinyl ester monomer in the polymer. Unit = 0.001 to 1.2 (molar ratio), reaction temperature 20
It is carried out at a temperature of 180 ° C and a reaction time of 0.1 to 20 hours.

The amino acid group-containing PVA polymer obtained by the production method (1) has a unit represented by the general formula of Chemical Formula 1 mainly in the molecular chain.

A in the unit represented by the general formula of Chemical formula 1 is 2
The structure is not particularly limited as long as it is a divalent hydrocarbon group or a divalent hydrocarbon group containing at least one atom selected from nitrogen atom, oxygen atom and sulfur atom, and-(CH
_{2 CH 2) n - (n} = 1~10, preferably 1 to 8), -
_{CH 2 OCH 2 -, - OCH} 2 -, - CONH-φ-O
_{CH 2 -, - CONHCH 2 -} , - CONHCH 2 OC
_{H 2 -, - CONHCH 2 OCH} 2 CH 2 -, - CON
_{HCH 2 OCH 2 CH 2 CH 2} -, - CONHCH 2 O
_{CH 2 CH 2 CH 2 CH 2} -, - CONHCH 2 -φ
Examples thereof include (CH ₃ ) ₂ —CH ₂ — (here, φ means a phenylene group).

X in the unit represented by the general formula
Is not particularly limited in its structure as long as it is a monovalent group containing an amino acid group, and —CH ₂ CH (NH ₂ ) —COOH,
_{-C (CH 3) 2 CH (} NH 2) -COOH, -CH 2
_{CH (NH (CH 3))} - COOH, -CH 2 CH (N
_{(CH 3) 2) -COOH,} -CH 2 CH (CONHC
_{H 2 COOH) -NHCOCH 2 CH 2} CH (NH 2)
COOH and salts thereof and betaine are exemplified.

Next, the waterproofing agent (B) used in the present invention will be described. The waterproofing agent (B) is not particularly limited as long as it reacts with the amino acid group-containing PVA-based polymer to cause cross-linking, and is a polyvalent epoxy compound, an aldehyde compound, a polyvalent isocyanate compound, an aziridine compound, an aluminum compound, or the like. , Various compounds can be used, among them, polyvalent epoxy compounds, aldehyde compounds,
At least one compound selected from polyvalent isocyanate compounds is preferably used.

Examples of the polyepoxy compounds include bisphenol A-diglycidyl ether, bisphenol A-di-β-methylglycidyl ether, bisphenol F-diglycidyl ether, tetrahydroxyphenylmethane tetraglycidyl ether, resorcinol diglycidyl ether, Brominated bisphenol A-diglycidyl ether, chlorinated bisphenol A-diglycidyl ether, hydrogenated bisphenol A-diglycidyl ether, bisphenol A-alkylene oxide adduct diglycidyl ether, novolac glycidyl ether, polyalkylene glycol diglycidyl ether, Glycidyl such as glycerin triglycidyl ether, pentaerythritol diglycidyl ether, epoxy urethane resin Glycidyl ethers, such as p- hydroxybenzoic acid glycidyl ether ester; ether type
Ester type; glycidyl ester type such as phthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, acrylic acid diglycidyl ester, dimer acid diglycidyl ester; glycidyl aniline, tetraglycidyl diaminodiphenylmethane, tri Glycidyl isocyanurate, glycidyl amine type such as triglycidyl aminophenol; linear aliphatic epoxy resin such as epoxidized polybutadiene and epoxidized soybean oil; 3,4-epoxy-6-methylcyclohexylmethyl (3,4-epoxy-6) -Methylcyclohexane) carboxylate,
3,4-epoxycyclohexylmethyl (3,4-epoxycyclohexane) carboxylate, bis (3,4
Alicyclic epoxy resins such as -epoxy-6-methylcyclohexylmethyl) adipate, vinylcyclohexene diepoxide, dicyclopentadiene oxide, bis (2,3-epoxycyclopentyl) ether and limonene dioxide; polyamide epichlorohydrin and the like.

Examples of the aldehyde compound include monoaldehydes such as formaldehyde, acetaldehyde, propionaldehyde, crotonaldehyde and benzaldehyde; dialdehydes such as glyoxal, malonaldehyde, glutaraldehyde, pimelindialdehyde, suberindialdehyde and dialdehyde starch Aldehydes are mentioned, and dialdehyde starch, glyoxal, glutaraldehyde and the like are preferably used.

The polyvalent isocyanate compound may be tolylene diisocyanate (hereinafter abbreviated as TDI), hydrogenated TDI, trimethylolpropane-TDI.
Additives (eg Bayer, trade name: Desmour
L), triphenylmethane triisocyanate, methylene bisphenyl isocyanate (hereinafter abbreviated as MDI), hydrogenated MDI, polymerized MDI, hexamethylene diisocyanate, xylylene diisocyanate, 4,4 ′
-Dicyclohexylmethane diisocyanate; isophorone diisocyanate and the like. Furthermore, it is also possible to use those obtained by dispersing these polyvalent isocyanate compounds in water using an emulsifier.

In the aqueous composition of the present invention, the weight ratio [(A) / (B)] of the amino acid group-containing PVA polymer (A) and the waterproofing agent (B) is not particularly limited, but usually, It is 99.9 / 0.1-50 / 50, preferably 99.5 / 0.5-70 / 30. (A) / (B)
When it exceeds 99.9 / 0.1, the water resistance of the aqueous composition may decrease, and when it is less than 50/50, the viscosity stability of the aqueous solution of the aqueous composition may decrease.

Further, in the present invention, an aqueous composition comprising at least one water-proofing agent (B) selected from polyvalent epoxy compounds, aldehyde compounds and polyvalent isocyanate compounds and an amino acid group-containing PVA polymer (A). It is one of the preferable embodiments to further add an aluminum compound (C) to the product. As the aluminum compound (C), a water-soluble aluminum compound is preferably used, and specifically, aluminum chloride, aluminum nitrate and its hydrate, aluminum sulfate (sulfate band).
Etc. are preferably used. Among them, aluminum chloride and aluminum nitrate are more preferably used.

The weight ratio [{(A) + (B)} / (C)] of the amino acid group-containing PVA polymer (A), the waterproofing agent (B) and the aluminum compound (C) is not particularly limited. , Usually 99.9 / 0.1-70 / 30,
It is preferably 99.5 / 0.5 to 80/20.
If {(A) + (B)} / (C) exceeds 99.9 / 0.1, the addition effect of the aluminum compound may not be observed, and if less than 70/30, the aqueous composition There is a concern that the viscosity stability of the aqueous solution may decrease.

The aqueous composition of the present invention has a pH of its aqueous solution.
Is in the range of 2.5 to 7.5 is essential. Furthermore, the pH of the aqueous solution of the aqueous composition is preferably in the range of 3 to 7, and more preferably in the range of 3.5 to 6.5. When the pH of the aqueous solution of the aqueous composition is out of the above range, the water resistance of the aqueous composition may decrease.

As described above, it is essential that the aqueous composition of the present invention contains the amino acid group-containing PVA polymer (A) and the water-proofing agent (B). A solvent, various additives, other water-soluble resin or polymer aqueous dispersion may be added to the aqueous composition of the present invention. Water is preferably used as a solvent for the aqueous composition, but a solvent such as various alcohols, ketones, dimethylformamide and dimethylsulfoxide may be used together therewith. Examples of the additives include various defoaming agents, various dispersants, nonionic or anionic surfactants, silane coupling agents, pH adjusting agents, and fillers such as calcium carbide, clay, talc, and flour. . Examples of the water-soluble resin include cellulose derivatives such as carboxymethyl cellulose and hydroxyethyl cellulose; poly (meth) acrylic acid, polyhydroxy (meth) acrylate or copolymers thereof, (meth) acrylic polymers such as polyacrylamide; polyvinylpyrrolidone or its Copolymers; PVA derivatives such as carboxyl group-containing modified PVA, sulfonic acid group-containing modified PVA, phosphoric acid group-containing modified PVA, quaternary ammonium salt group-containing modified PVA; and general PVA. As the polymer aqueous dispersion, an acrylic polymer, an ethylene-vinyl acetate copolymer, a vinyl ester polymer,
An aqueous dispersion such as a styrene-butadiene copolymer may be mentioned.

The aqueous composition of the present invention is usually used by dissolving or dispersing it in water or water containing the above-mentioned organic solvent. Moreover, the aqueous composition of the present invention comprises an amino acid group-containing PV.
In addition to mixing the A-based polymer (A) and the waterproofing agent (B) in advance and using them as an aqueous composition, either the amino acid group-containing PVA-based polymer (A) or the waterproofing agent (B) is used. After using it first, add the other later,
It can also be used as an aqueous composition. For example, when the aqueous composition of the present invention is used as an overcoating agent for paper, the amino acid group-containing PVA-based polymer (A) and the water-proofing agent (B) are mixed in advance and then applied to the surface of the paper. The agent (B) is first applied to the paper surface, and the amino acid group-containing PV
The A-based polymer (A) may be later applied thereon. When the aqueous composition of the present invention is used for an adhesive, the amino acid group-containing PVA polymer (A) and the water-proofing agent (B) are mixed in advance and then applied to the adherend to be adhered. Alternatively, the water-proofing agent (B) may be applied to one of the surfaces to be adhered, and the amino acid group-containing PVA polymer (A) may be applied to the other surface and then laminated.

The aqueous composition of the present invention is excellent in film-forming property at low temperature, film strength and water resistance, and further, because it is free from coloring over time, it cannot be heat-treated at a high temperature, especially at high temperature. Used as an overcoat agent for thermal paper. Further, inorganic or organic adhesives such as adhesives for plywood secondary processing, binders for ceramics, dispersants such as pigment dispersants, polymerization stabilizers for crosslinkable emulsions, image forming materials such as gelatin blends or photosensitive resins, It is effectively used as a base material for hydrogels such as cell-immobilized gel or enzyme-immobilized gel, vehicle for paints, treatment agent for inorganic or organic materials, surface coating agent, etc. It can be widely used for various purposes. Further, it can be used for molded products such as films, sheets and fibers.

[0028]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In the following examples, "%" and "part" are "% by weight" unless otherwise specified.
And "parts by weight".

(Evaluation of Aqueous Composition) (1) Water resistance of film The water-soluble composition was cast on a polyethylene terephthalate (hereinafter abbreviated as PET) film at 20 ° C. and 65% RH and dried for 7 days. To obtain a dry film having a thickness of 500 μm.
This coating was punched out to a diameter of 2.5 cm, and the water absorption of the coating when it was immersed in 20 ° C. water for 24 hours as a sample,
The dissolution rate was calculated. Water absorption rate (%): {(water absorption weight after immersion / film absolute dry weight before immersion) -1} × 100 Elution rate (%): {1- (film absolute weight after immersion / film before immersion) Absolute dry weight)} × 100 * absolute dry weight of the film before immersion; film weight before immersion (water content)-
{Film weight before immersion (water content) x film water content (%) / 10
0} * Water content of film: The film (a sample different from the sample immersed in water at 20 ° C) is dried at 105 ° C for 4 hours, and the water content of the film is determined in advance. * Film thickness after soaking: 105 ℃ at 4 ℃
Time-dry weight. * Water absorption weight of the film after immersion: After the film after immersion is pulled out from water, the water on the film is wiped off with gauze and weighed. (2) Coloring over time (coloring of the aqueous solution) A 10% aqueous solution of the aqueous composition was added at 20 ° C. 6
After standing for 1 month under 5% RH, the coloring of the aqueous solution was visually observed and evaluated according to the following criteria. ◯: No coloration, Δ: Yellow coloration, X: Brown coloration (coating coloration) PE composition of the aqueous composition at 20 ° C. and 65% RH
It was cast on T and dried for 7 days to obtain a dry film of 500 μm. After leaving this film for 1 week in an outdoor environment exposed to direct sunlight, the coloration of the film was visually observed and evaluated according to the following criteria. ○: No coloring, △: slightly colored yellow, ×: colored yellow

Synthesis Example 1 (Amino acid group-containing PVA polymer
Of) Equipped with stirrer, reflux condenser, nitrogen inlet and thermometer
In the reactor, 405 parts vinyl acetate monomer, allyl glycidyl
Charge 11 parts of ruthenium and 30 parts of methanol,
The raw gas was bubbled for 15 minutes to degas. Separately, meta
2,2-azobisisobutyronitrile in 15 parts of knoll
Prepare an initiator solution in which 4.5 parts was dissolved and add a nitrogen gas bath.
The nitrogen was replaced by bling. Start heating the reactor,
When the internal temperature reached 60 ° C, the above-mentioned initiator was added to the reactor.
The solution was added to initiate the polymerization. Polymerize at 60 ° C for 4 hours
At that point, the reactor was cooled to stop the polymerization. At this time
The solid content concentration was 54.8%. Subsequently, depressurize at 30 ℃
Unreacted vinyl acetate with occasional addition of methanol below
After removing the monomer, the vinyl acetate copolymer methanol
A solution (concentration 44.5%) was obtained. This vinyl acetate copolymer
Allylic glycidyl ester obtained from proton NMR measurement of body
The content of ether units (epoxy groups) is 2.1 mol%
, The viscosity average molecule obtained by measuring the intrinsic viscosity in acetone
The amount is 80 × 10 ^ThreeMet. Next, stirrer and reflux cooling
In a reactor equipped with a tube, a nitrogen inlet tube and a thermometer,
The obtained vinyl acetate copolymer having epoxy group
Weigh 100 parts of a nol solution (concentration 44.5%), 1
After bubbling with nitrogen gas for 5 minutes, 12 parts of cysteine
And 0.2 parts of sodium hydroxide dissolved in 48 parts of methanol
The resulting mixture was charged and reacted at 50 ° C for 2 hours with stirring.
Let Then, cool to 40 ° C and then add 10%
40 parts of methanol solution of sodium iodide was added,
It was left to stand for 5 hours for saponification. Solid after saponification
48 hours after crushing the components and neutralizing by adding 8 parts of acetic acid
Soxhlet extraction with methanol at 60 ° C for 20:00
PVA-based polymer containing amino acid group (PVA
-1) was obtained. Obtained from proton NMR measurement of PVA-1
The content of amino acid groups is 2.1 mol%, vinyl alcohol
Content (saponification degree) in units of 88 mol%, JIS
The degree of polymerization measured according to K6726 is 1000.
It was

Synthesis Example 2 (Synthesis of PVA Polymer Containing Amino Acid Group) Amino acid was prepared in the same manner as in Synthesis Example 1 except that 60 parts of a methanol solution containing 10% sodium hydroxide was added during saponification. Amino acid group-containing P having a group content of 2.1 mol%, a saponification degree of 97 mol% and a polymerization degree of 1000
A VA polymer (PVA-2) was obtained.

Comparative Synthetic Example (Synthesis of PVA Polymer Having Amino Group Bonded to Phenyl Group) In Synthetic Example 1, 100 parts of a vinyl acetate copolymer having an epoxy group in methanol (concentration 44.5%). Amino group-containing PVA in the same manner as in Synthesis Example 1 except that 13 parts of 2-aminothiophenol and 0.1 part of sodium hydroxide are reacted instead of reacting 12 parts of cysteine with 0.2 part of sodium hydroxide. A polymer (PVA-3) was obtained. The content of the amino group bonded to the phenyl group obtained from the proton NMR measurement of PVA-3 was 2.1 mol%, the content of the vinyl alcohol unit (saponification degree) was 97.5 mol%, and the content was measured according to JIS K6726. The degree of polymerization was 1
It was 000.

Example 1 To 100 parts of a 10% aqueous solution of PVA-1 obtained in Synthesis Example 1 was added 0.3 part of ethylene glycol diglycidyl ether, which is a polyvalent epoxy compound, as a waterproofing agent (B). An aqueous composition was prepared. This aqueous composition was evaluated by the method described above. The results are shown in Table 1.

Example 2 As a waterproofing agent (B), the same procedure as in Example 1 was carried out except that 0.3 part of glyoxal, which is an aldehyde compound, was added in place of the polyepoxy compound used in Example 1.
An aqueous composition was prepared and evaluated. The results are shown in Table 1.

Example 3 Instead of the polyvalent epoxy compound used in Example 1 as the water-proofing agent (B), a polyvalent isocyanate compound manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Coronate C-305.
An aqueous composition was prepared and evaluated in the same manner as in Example 1 except that 0.5 part of 3 was added. The results are shown in Table 1.

Example 4 To 100 parts of a 10% aqueous solution of PVA-1 obtained in Synthesis Example 1, 0.3 part of ethylene glycol diglycidyl ether, which is a polyvalent epoxy compound, as a waterproofing agent (B), and an aluminum compound were used. As (C), 0.2 part of aluminum nitrate nonahydrate was added to prepare an aqueous composition. This aqueous composition was evaluated by the method described above. The results are shown in Table 1.

Comparative Example 1 An aqueous composition was prepared and evaluated in the same manner as in Example 1, except that the polyhydric epoxy compound, ethylene glycol diglycidyl ether, was not used. The results are shown in Table 1.

Example 5 An aqueous composition was prepared and evaluated in the same manner as in Example 1 except that PVA-2 obtained in Synthesis Example 2 was used instead of PVA-1 used in Example 1. . The results are shown in Table 1.

Comparative Example 2 An aqueous composition was prepared and evaluated in the same manner as in Example 1 except that PVA-3 obtained in Comparative Synthesis Example was used instead of PVA-1 used in Example 1. . The results are shown in Table 1.

Comparative Example 3 0.5 part of glyoxal was added to 100 parts of a 10% aqueous solution of PVA-4 containing an acetoacetyl group (acetoacetyl group content: 3 mol%, polymerization degree: 1000, saponification degree: 98 mol%). An aqueous composition was prepared. This aqueous composition was evaluated by the method described above. The results are shown in Table 1.

Comparative Example 4 Polyamide epichlorohydrin resin (WS manufactured by Nippon PMC Co., Ltd.) was added to 100 parts of a 10% aqueous solution of PVA-5 containing a carboxyl group (carboxyl group content 2 mol%, polymerization degree 1000, saponification degree 96 mol%). -525) 3 parts were added to prepare an aqueous composition. This aqueous composition was evaluated by the method described above. The results are shown in Table 1.

Example 6 1N sulfuric acid was added to the aqueous solution of the aqueous composition prepared in Example 1 to adjust the pH to 2. This aqueous composition was evaluated by the method described above. The results are shown in Table 1.

Example 7 Ammonia water was added to the aqueous solution of the aqueous composition prepared in Example 1 to adjust the pH to 9. This aqueous composition was evaluated by the method described above. The results are shown in Table 1.

Example 8 To 100 parts of a 10% aqueous solution of PVA-1 obtained in Synthesis Example 1 was added 0.03 part of ethylene glycol diglycidyl ether, which is a polyvalent epoxy compound, as a waterproofing agent (B), and the aqueous solution was prepared. A composition was prepared. This aqueous composition was evaluated by the method described above. The results are shown in Table 1.

Example 9 To 100 parts of a 10% aqueous solution of PVA-1 obtained in Synthesis Example 1, 5 parts of ethylene glycol diglycidyl ether, which is a polyvalent epoxy compound, was added as a waterproofing agent (B) to prepare an aqueous composition. Was prepared. The evaluation of this aqueous composition was performed by the method described above. The results are shown in Table 1.

[0046]

[Table 1]

[0047]

The aqueous composition of the present invention has excellent water resistance,
Furthermore, it has the feature of not coloring over time, and is used for inorganic or organic adhesives such as paper overcoating agents, thermal paper overcoating agents, and plywood secondary processing adhesives.
Binder for ceramics, dispersant such as pigment dispersant,
Polymerization stabilizer for cross-linkable emulsion, image forming material such as gelatin blend or photosensitive resin, substrate for hydrogel such as gel for fixing cells or enzyme, vehicle for paint, treating agent for inorganic material or organic material, surface Effectively used as a coating agent.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09J 129/04 C09J 129/04 F term (reference) 4J002 AB043 BE011 BE021 CD012 CD022 CD032 CD052 CD132 CD162 CD201 CD202 DD077 DE147 DF037 DG047 EE016 ER008 FD202 FD203 FD206 FD207 FD208 HA07 4J040 DD021 EC002 GA13 GA23 HA096 HA226 HA256 HB17 JA03 LA06 LA07 LA08 MA09

Claims (6)

[Claims] 1. A vinyl alcohol-based polymer (A) containing 0.1 to 10 mol% of a monomer unit having an amino acid group in the molecule and having a saponification degree of 70 mol% or more, and a waterproofing agent (B). ), Wherein the aqueous solution has a pH of 2.5 to 7.5. 2. A water resistant agent (B) is a polyvalent epoxy compound,
The aqueous composition according to claim 1, which is at least one compound selected from an aldehyde compound and a polyvalent isocyanate compound. 3. The aqueous composition according to claim 1, which further comprises an aluminum compound (C) in addition to the vinyl alcohol polymer (A) and the waterproofing agent (B). 4. The weight blending ratio (A) / (B) of the vinyl alcohol polymer (A) and the waterproofing agent (B) is 99.9.
/0.1-50/50, The aqueous composition of Claims 1-3. 5. A monomer unit containing an amino acid group is
The aqueous composition according to claim 1, which is represented by the general formula of. [Chemical 1] (Here, R ¹ , R ² , R ³ , R ⁴ and R ⁵ each represent a hydrogen atom or a hydrocarbon group which may have a substituent having 8 or less carbon atoms, and A represents a divalent carbon atom. A hydrogen group or a divalent hydrocarbon group containing at least one atom selected from nitrogen atom, oxygen atom and sulfur atom, S represents a sulfur atom, and X represents a monovalent group containing an amino acid group. .) 6. An adhesive using the aqueous composition according to claim 1.