JPH09176369A - Modifier for aqueous resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an aqueous resin modifier, comprising a specific inorganic acid (salt) and capable of improving the water and weather resistances by addition thereof when curing an aqueous resin and useful for providing a cured product excellent in prevention, etc., of coloring. SOLUTION: This modifier for an aqueous resin comprises an oxo acid of sulfur and its salt, preferably an alkali metallic salt of the oxo acid of sulfur, especially preferably at least one selected from among an alkali metallic salt of sulfuric acid such as NaHSO4 and an alkali metallic salt of sulfurous acid such as Na2 SO3 or NaHSO3 as an active component. The modifier is preferably used in an amount of 0.01-20wt.%, preferably 3-15wt.% based on that of a curing agent used in combination therewith. The curing agent is preferably the one such as a dibasic acid dihydrazide.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a modifier for an aqueous resin. More specifically, the present invention improves the water resistance and weather resistance of a water-based resin cured product cured using a dibasic acid dihydrazide and the like, and is also useful as a modifier for a water-based resin that is also useful for preventing coloration of the cured product. Regarding

[0002]

Conventionally, paints have been applied to various base materials such as metal, cement, plastic, and wood for the purpose of protecting the surface of articles and imparting aesthetics. Thus, as a conventional coating material, various synthetic resins, which are the main components, are dissolved in an organic solvent, and a plasticizer, a pigment, and the like are added thereto as needed, which is often used. As described above, the use of an organic solvent as a solvent in a conventional coating material results in a coating solution in which the components are uniformly dissolved because the synthetic resin is easily dissolved in the organic solvent, and as a result, the coating solution has uniform properties when cured. Due to the formation of the film. However, under the current situation where interest in environmental protection and safety demands of workers are rapidly increasing, organic solvents, which are highly toxic and easily ignite and cause fire, are shunned, and organic solvents are changed to water that does not adversely affect the environment. Substitution is progressing.

On the other hand, among synthetic resins which are the main components of paints, acrylic resins have high transparency and good weather resistance, and fluororesins are particularly widely used because of their excellent weather resistance and stain resistance. . However, in response to the present demand, an aqueous paint prepared by dispersing a fluororesin or an acrylic resin in water is usually used for curing to form a coating film.
It is necessary to heat at a high temperature of up to about 200 ° C., and further, the cured film formed has insufficient mechanical strength, and there is a drawback that long-term durability becomes low. The drawbacks of such water-based paints are eliminated by adding a dibasic acid dihydrazide such as adipic acid dihydrazide, malonic acid dihydrazide and glutaric acid dihydrazide as a curing agent, while the addition of the curing agent is It causes an unfavorable adverse effect such as yellowing or reddening of the coating, deterioration of water resistance and weather resistance of the coating, whitening or clouding due to contact with water, and further generation of blisters.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventor has found that when curing an aqueous resin with a curing agent such as dibasic acid dihydrazide, a specific curing agent is used together with the curing agent. By adding an inorganic acid or a salt thereof to the water-based resin, water resistance and weather resistance are remarkably improved, discoloration such as yellowing and redning is very unlikely to occur, and mechanical strength is high and long-term durability is improved. It was found that an excellent cured product was obtained, and the present invention was completed here.

That is, the present invention relates to a modifier for an aqueous resin containing as an active ingredient at least one selected from sulfur oxo acids and salts thereof.

When the aqueous resin is cured with a curing agent such as dibasic acid dihydrazide, if the curing agent is used in combination with the aqueous resin modifier of the present invention, water resistance and weather resistance are remarkably improved. Discoloration such as discoloration or red discoloration is extremely unlikely to occur, and a cured product having high mechanical strength and excellent long-term durability can be obtained.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The oxo acid of sulfur and its salt, which are the active ingredients of the modifier for aqueous resins of the present invention, are added to an aqueous resin together with a curing agent (the “dihydrazide compound” described below, the same applies hereinafter). . The oxo acid of sulfur and its salt are not particularly limited, and conventionally known ones can be widely used. Among them, alkali metal salts of oxo acid of sulfur are preferable.
Furthermore, alkali metal salts of sulfuric acid such as NaHSO ₄ , Na ₂ S
Alkali metal salts of sulfurous acid such as O ₃ and NaHSO ₃ , Na ₂
More preferable are alkali metal salts of thiosulfates such as S ₂ O ₃ , alkali metal salts of sulfoxylic acid, alkali metal salts of peroxosulfate, and the like, alkali metal salts of sulfuric acid such as NaHSO ₄ , Na ₂ SO ₃ , NaHSO _{3 and the} like. Alkali metal salts of sulfite, alkali metal salts of thiosulfate such as Na ₂ S ₂ O _{3 and the} like are particularly preferable. The sulfur oxo acids and salts thereof may be used alone or in combination of two or more. The amount of the sulfur oxo acid and its salt is not particularly limited, and can be appropriately selected from a wide range according to various conditions such as the type and application of the aqueous resin and the type of the curing agent used in combination. About 0.01 to 20% by weight of the amount used, preferably 3 to 15
It may be set to about weight%.

The curing agent used in combination with the aqueous resin modifier of the present invention is a compound having at least one, preferably two or more hydrazide groups in one molecule (hereinafter referred to as "hydrazide group-containing compound"). . The hydrazide group-containing compound is not particularly limited, and conventionally known compounds can be used.
Specifically, for example, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, maleic acid dihydrazide, fumaric acid, fumaric acid, fumaric acid. Dibasic acid dihydrazides such as dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, phthalic acid dihydrazide, (tere) isophthalic acid dihydrazide, pyromellitic acid di-, tri- and tetrahydrazide, 2,6-naphthoic acid dihydrazide and other aromatic polyhydric compounds polyhydrazides of carboxylic acid, dihydrazide carbonate, carbohydrazide, the general formula NH ₂ -NH-CO-NHR
NH-CO-NHNH ₂ [wherein R is, for example o-, m-,
A p-phenylene group, a toluylene group, a cyclohexylidene group, a methylcyclohexylidene group and the like are shown. ] An alicyclic or aromatic bissemicarbazide represented by the following, dicarboxylic acid di- or tri-hydrazides, disulfonic acid dihydrazides such as bis (hydrazinesulfonyl) benzene, trisulfonic acid di- or trihydrazide Examples thereof include polyacrylic acid polyhydrazide, nitriloacetic acid trihydrazide, ethylenediaminetetraacetic acid tetrahydrazide, and the like. Among these, dibasic acid dihydrazides, polyhydrazides of aromatic carboxylic acids, carbohydrazide and the like are preferable, and adipic acid dihydrazide, glutaric acid dihydrazide, malonic acid dihydrazide,
2,6-naphthoic acid dihydrazide, isophthalic acid dihydrazide, carbohydrazide and the like are particularly preferable. The hydrazide group-containing compound may be used alone or in combination of two or more. The amount of the hydrazide group-containing compound used is not particularly limited and can be appropriately selected from a wide range according to various conditions such as the type and application of the aqueous resin, but is usually 0.01 to 20% by weight of the solid content weight of the aqueous resin. The amount may be about 0.1 to 10% by weight.

In the present invention, conventionally known curing agents other than hydrazide group-containing compounds, such as tertiary amines, imidazoles, acid anhydrides, etc., within the range that does not impair the effects of the aqueous resin modifier of the present invention. You may use together 1 type, or 2 or more types, such as a dicyandiamide compound and carboxylic acid.

The water-based resin modifier of the present invention can be used in various conventionally known water-based resins. Specific examples thereof include, for example, vinyl acetate emulsion, polyvinyl alcohol emulsion, styrene butadiene emulsion, acrylic emulsion, water-soluble alkyd resin paint, water-soluble epoxy resin paint, water-soluble polybutadiene resin paint, fluororesin and modified fluorine. Examples thereof include water-based dispersion paints of resins.

Among these, acrylic emulsions, water-based dispersion paints of fluororesins and modified fluororesins, etc. can be preferably used.

Known acrylic resins can be used as the acrylic resin contained in the acrylic emulsion. For example, at least one acrylic monomer selected from the following non-functional monomers, monofunctional monomers and polyfunctional monomers can be used. It can include those that include. Specific examples of the non-functional monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, ( Tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth)
Octyl acrylate, isodecyl (meth) acrylate,
Lauryl (meth) acrylate, lauryl (meth) acrylate-tridecyl, tridecyl (meth) acrylate,
Examples thereof include cetyl-stearyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, and benzyl (meth) acrylate. Specific examples of the monofunctional monomer include (meth) acrylic acid, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate,
Examples thereof include dimethylaminoethyl (meth) acrylate, tert-butylaminoethyl (meth) acrylate, glycidyl (meth) acrylate, and tetrahydrofurfuryl (meth) acrylate. Specific examples of the polyfunctional monomer include, for example, ethylene di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and di (meth) acrylate. Meta)
Decaethylene glycol acrylate, pentadecaethylene glycol di (meth) acrylate, pentacontaethylene glycol di (meth) acrylate, 1,3-butylene di (meth) acrylate, allyl (meth) acrylate, tri ( Meth) acrylic acid trimethylolpropane, tetra (meth) acrylic acid pentaerythritol,
Examples thereof include diethylene glycol di (meth) acrylate and phthalate. These acrylic monomers are used alone or in combination of two or more.
Furthermore, the acrylic resin used in the present invention may contain a monomer copolymerizable with the acrylic monomer. Specific examples of the monomer include vinyl acetate, vinyl chloride, styrene, vinyltoluene, α-methylstyrene, vinyltoluene, ethylene, propylene,
(Meth) acrylamide, (meth) acrylonitrile,
A known monomer copolymerizable with an acrylic monomer such as (meth) acryloylmorpholine and (meth) acryloguanamine may be contained. These monomers are also 1
The seeds may be used alone or in combination of two or more. The acrylic resin can be produced by polymerizing one or more of the above various monomers according to a known method such as an emulsion polymerization method.

As the fluororesin contained in the water-based dispersion paint, conventionally known ones can be widely used, and examples thereof include a fluoroolefin-based monomer or a polymer of a fluoroolefin-based monomer and another copolymerizable monomer. Can be mentioned.

Known fluoroolefin monomers can be used, for example, vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, 1,1,3,3,3-pentafluoropropylene, 2, 2,3,3-tetrafluoropropylene,
1,1,2-trifluoropropylene, 3,3,3-trifluoropropylene and the like can be mentioned. In the present invention, for example, chlorotrifluoroethylene, bromotrifluoroethylene, 1-chloro-1,2-difluoroethylene, 1-chloro-2,2-difluoroethylene, 1,1, -dichloro-2,2. A monomer such as difluoroethylene containing fluorine and other halogen atoms (chlorine, bromine, etc.) is also included in the fluoroolefin-based monomer. The fluoroolefin-based monomers may be used alone or in combination of two or more. When the fluoroolefin-based monomer and another copolymerizable monomer are copolymerized, the amount of the fluoroolefin-based monomer is not particularly limited and can be appropriately selected from a wide range, but is usually about 10 to 80% by weight, preferably It may be about 20 to 60% by weight.

Other monomers copolymerizable with the fluoroolefin-based monomer are not particularly limited, and known ones can be used. Specifically, for example, the following (1) to (1
2) can be mentioned.

(1) Unsaturated carboxylic acids and their esters; crotonic acid, itaconic acid, citraconic anhydride, itaconic anhydride, fumaric acid, maleic acid, acrylic acid, methacrylic acid and the like.

(2) Unsaturated group-containing polyhydroxyalkyl esters; dihydroxyalkyl esters of unsaturated group-containing polyvalent carboxylic acids such as citraconic acid and itaconic acid.

(3) Alkyl vinyl ethers; methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether, n-butyl vinyl ether, isoamyl vinyl ether, n-
Hexyl vinyl ether, n-octyl vinyl ether, 2-ethylhexyl vinyl ether, cyclopentyl vinyl ether, cyclohexyl vinyl ether, benzyl vinyl ether, phenethyl vinyl ether and the like.

(4) (per) fluoroalkyl vinyl ethers; (per) fluoromethyl vinyl ether,
(Per) fluoroethyl vinyl ether, (per) fluoropropyl vinyl ether, (per) fluorooctyl vinyl ether, (per) fluorocyclohexyl vinyl ether and the like.

(5) Hydroxyalkyl vinyl ethers; 4-hydroxybutyl vinyl ether and the like.

(6) Carboxylic acid vinyl ester; vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl neononanoate, vinyl neodecanoate, vinyl laurate, vinyl stearate, 2 -Vinyl ethylhexanoate, p-
Vinyl t-butyl benzoate, vinyl benzoate, vinyl salicylate, vinyl monochloroacetate, vinyl cyclohexanecarboxylate and the like.

(7) (Halogenated) olefins; vinyl chloride, vinylidene chloride, ethylene, propylene, 1-
Butene etc.

(8) Crosslinkable monomers having two or more polymerizable unsaturated groups in the molecule; butadiene, hexadiene, octadiene, decadiene, tetradecadiene, 2-methyloctadiene, decatriene, diallylphthalate and the like.

(9) Hydrolyzable silyl group-containing monomer;
Vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, γ
-Methacryloxypropyltriethoxysilane, vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane and the like.

(10) Fluoroalkyl group-containing vinyl monomer; (11) Carbonyl group-containing vinyl monomer; acrolein, diacetone acrylamide, formyl styrene,
Vinyl-alkyl ketone, acryloxy or methacryloxy-alkyl propanal, acrylamido pivalin aldehyde, 3-acrylamidomethyl-anisaldehyde, diacetone acrylate, acetonyl acrylate, diacetone methacrylate, 2-hydroxypropyl acrylate acetyl acetate, butanediol acrylate acetyl acetate etc.

(12) Vinyl monomers other than the above: methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, 2-acrylic acid acrylate Ethylhexyl, lauryl acrylate, tridecyl acrylate, stearyl acrylate, cyclohexyl acrylate, dimethylaminoethyl acrylate, glycidyl acrylate, 2-hydroxyethyl acrylate, acrylic acid esters such as 2-hydroxypropyl acrylate, methacrylic acid Methyl, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, 2-ethylhexyl methacrylate Methacrylic lauryl methacrylate, tridecyl methacrylate, stearyl methacrylate, cyclohexyl methacrylate, diethylaminoethyl methacrylate, tert-butylaminoethyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, methacrylic acid Methacrylic acid esters such as 2-isocyanatoethyl, styrenes such as styrene, vinyltoluene, α-methylstyrene, chlorostyrene, acrylonitrile, methacrylonitrile, vinyl chloride, vinyl formate, vinyl propionate, vinyl stearate, maleic acid. Monoacrylates or monomethacrylates of polyhydric alcohols such as dialkyl esters, divinyl benzene, glycerin and trimethylolpropane.

The above monomers may be used alone or in combination of two or more.

The fluororesin can be produced by a known method. For example, according to the emulsion polymerization method, a fluoroolefin-based monomer and a copolymerizable monomer may be dispersed in water with an emulsifier, and a polymerization initiator may be added thereto.
Known emulsifiers and polymerization initiators can be used, and specific examples thereof are as follows, but these can also be used for emulsion polymerization of acrylic resins.

Examples of the emulsifier include anionic emulsifiers such as alkylbenzene sulfonate, alkylnaphthalene sulfonate, higher fatty acid salt, alkyl sulfate ester salt, alkyl ether sulfate ester salt, phosphate ester salt and perfluoroalkyl fatty acid salt. , Alkylphenol ethylene oxide adducts, higher alcohol ethylene oxide adducts, nonionic emulsifiers such as block copolymers of ethylene oxide and propylene oxide, reactive emulsifiers, fluorine-based surfactants, acrylic oligomers, etc. It is possible to use one kind or two or more kinds.

Examples of the polymerization initiator include water-soluble inorganic catalysts such as potassium persulfate and ammonium persulfate, water-soluble inorganic peroxides such as hydrogen peroxide, ammonium persulfate, potassium persulfate and sodium persulfate. Persulfates, cumene hydroperoxide, organic peroxides such as benzoyl peroxide, and azo-based polymerization initiators such as azobisisobutyronitrile and azobiscyanovaleric acid. Can be used.

Among the aqueous dispersions of fluororesin obtained by the above method, for example, tetrafluoroethylene resin (PTFE), tetrafluoroethylene-6-fluoropropylene resin (FEP), tetrafluoroethylene-perme Fluoroalkoxyethylene copolymer resin (PFA), 4-fluoroethylene-ethylene copolymer (ETFE), trifluorochloroethylene copolymer (CTFE), ethylene-3 fluoroethylene chloride copolymer (ECTFE), Those containing a fluororesin such as vinyl fluoride resin (PVF) are preferable.

Further, as the modified fluororesin coating material, for example, an aqueous dispersion containing tetrafluoroethylene resin (PTFE), tetrafluoroethylene-6-fluoropropylene resin (FEP) or the like, an acrylic resin, an epoxy resin, Examples thereof include those modified by adding urethane resin, phenol resin and the like.

The aqueous resin composition containing the modifier for an aqueous resin and the hydrazide group-containing compound of the present invention can be suitably used for the original purpose of the aqueous resin. For example, in the case of fluororesin, as paint, and in the case of acrylic resin,
It can be used as an adhesive, paint, paper processing agent, fiber processing agent, etc.

[0034]

EXAMPLES The present invention will be described in detail below with reference to reference examples, examples and comparative examples. In the following, "parts" and "%" mean "parts by weight" and "% by weight", respectively.

Reference Example 1 84 parts of ethylene glycol monomethyl ether was placed as a solvent component in a 1-liter flask equipped with a stirrer, a heat exchanger, a thermometer, a dropping funnel and a polymerization initiator charging port.
Then butyl acrylate 141.5 as a monomer component
Parts, acrylic acid (80% aqueous solution) 32.3 parts and diacetone acrylamide 3.7 parts were uniformly mixed and dissolved, 1/4 of which was put in a flask and the rest was used for dropping. The internal temperature was raised to 70 ° C with stirring, and isopropyl alcohol 10
0.24 parts of benzoyl peroxide dissolved in 1 part was added, the internal temperature was further raised to 90 ° C., and the reaction was carried out for 30 minutes. Then, the monomer solution for dropping prepared above was added dropwise over 1 hour.
20 minutes after the completion of dropping, 0.24 part of benzoyl peroxide dissolved in 6 parts of isopropyl alcohol was added again, and the mixture was aged for 2 hours. After that, the internal temperature is cooled to 50 ° C or lower, and
A solution prepared by diluting 27% by weight of aqueous ammonia solution with 27 parts of water was gradually added dropwise and uniformly mixed, and then 523 parts of water was added to produce an aqueous resin.

Examples 1 to 6 To 100 parts of the aqueous resin of Reference Example 1, 20 parts of a 10% aqueous solution of the hydrazide derivative shown in Table 1 below and 4 parts of a 5% aqueous solution of the modifier of the present invention shown in Table 1 were added, An aqueous resin composition was produced.

The water resistance and colorability of the obtained aqueous resin composition were evaluated by the following methods according to JIS K 5400. The results are shown in Table 1.

1) Preparation of Sample First, the aqueous resin composition was applied to a glass plate (150 × 70 × 2 m).
m) and dried at 20 ° C. for 1 week to obtain a sample.

2) Water resistance test After being immersed in water at 20 ° C. for 18 hours, the state of change of the coated surface was visually judged.

After dipping in warm water of 80 ° C. for 2 hours, the change state of the coated surface was visually judged.

The criteria for judgment are as follows.

◯: No abnormality at all Δ: Slightly clouding, whitening, etc. are observed ×: Clouding, whitening, blistering, etc. are remarkable.

3) Coloring test (a) After the accelerated test for 3000 hours with a sunshine weather meter, the degree of coloring was visually determined.

(B) After being stored in an incubator at 80 ° C. for 1 week, the degree of coloring was visually determined.

[0045]

[Table 1]

Comparative Examples 1 to 4 To 100 parts of the aqueous resin of Reference Example 1, only 20 parts of a 10% aqueous solution of a hydrazide derivative shown in Table 2 below was added, and in the same manner as in Example 1 below, a water resistance test and a coloring test were conducted. I went.
Table 2 shows the results.

[0047]

[Table 2]

Reference Example 2 720 parts of ion-exchanged water, 16 parts of sodium dodecylbenzenesulfonate, 8 parts of polyoxyethylene nonylphenol ether (HLB = 17) and 3 parts of ammonium hydrogen carbonate were put into a 2 liter stainless steel autoclave and dissolved. Then, the inside of the autoclave was replaced with nitrogen.

Then, 8 parts of crotonic acid, 424 parts of vinyl ester of branched saturated aliphatic carboxylic acid (trade name: Veova 9, manufactured by Shell Co., Netherlands), and 1 of crotonaldehyde.
6 parts and 320 parts of liquefied vinylidene fluoride were placed in a pressure-resistant dropping tank, and ethylene was further injected so that the internal pressure of the autoclave became 15 atm.

The autoclave was heated to 80 ° C., and while stirring, 5.6 parts of ammonium persulfate was added to ion exchange water 8
What was melt | dissolved in 0 part and the monomer put in the pressure-resistant dropping tank were dripped over 3 hours, and it hold | maintained at the same temperature for 3 hours after that.

The resulting reaction mixture was a polymer emulsion, its non-volatile content was 50% and its pH was 1.6.
After cooling the reaction mixture to room temperature, 14% aqueous ammonia was added to adjust the pH to 7.5, and then hydrazine 8
Part, and then ion-exchanged water to add a nonvolatile content of 45%
To obtain an aqueous resin dispersion in which a resin having a Tg of 0 ° C., a softening point of 70 ° C. and an average particle diameter of 0.08 μm is dispersed.

Examples 7 to 11 To 100 parts of the aqueous resin dispersion of Reference Example 2, 10 parts of a 10% aqueous solution of the hydrazide derivative shown in Table 3 below and 5% of the additive were added.
An aqueous resin composition was produced by adding 4 parts of the aqueous solution. This aqueous resin composition was subjected to the same water resistance test and coloring test as in Examples 1 to 6. The results are also shown in Table 3.

[0053]

[Table 3]

Comparative Examples 5 to 7 To 100 parts of the aqueous resin dispersion of Reference Example 2, only 10 parts of a 10% aqueous solution of a hydrazide derivative shown in Table 4 below was added to prepare an aqueous resin composition. This aqueous resin composition was subjected to the same water resistance test and coloring test as in Examples 1 to 6. The results are also shown in Table 4.

[0055]

[Table 4]

Examples 12 to 13 Acetoacetylation degree 6.0 mol%, Saponification degree 99 mol%
An aqueous resin composition was prepared by adding 10 parts of a 10% aqueous solution of adipic dihydrazide and 4 parts of a 5% aqueous solution of the additives shown in Table 5 below to 100 parts of a 10% aqueous solution of acetoacetylated polyvinyl alcohol.

This aqueous resin composition was subjected to the same water resistance test and coloring test as in Examples 1-6. The results are also shown in Table 5.

[0058]

[Table 5]

Comparative Examples 8 to 9 Acetoacetylation degree 6.0 mol%, Saponification degree 99 mol%
10% of the hydrazide derivative shown in Table 6 below in 100 parts of a 10% aqueous solution of acetoacetylated polyvinyl alcohol.
An aqueous resin composition was produced by adding only 10 parts of the aqueous solution. This aqueous resin composition was subjected to the same water resistance test and coloring test as in Examples 1 to 6. The results are also shown in Table 6.

[0060]

[Table 6]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsukasa Maekawa 463 Kagasuno, Kawauchi Town, Tokushima City, Tokushima Prefecture Otsuka Chemical Co., Ltd., Tokushima Plant

Claims (3)

[Claims] 1. A modifier for an aqueous resin containing as an active ingredient at least one selected from sulfur oxo acids and salts thereof. 2. The modifier for an aqueous resin according to claim 1, which comprises an alkali metal salt of oxo acid of sulfur as an active ingredient. 3. The aqueous resin according to claim 2, wherein the alkali metal salt of oxo acid of sulfur is at least one selected from alkali metal salt of sulfuric acid, alkali metal salt of sulfurous acid and alkali metal salt of thiosulfate. Modifier.