JPH10245426A - Water-soluble acrylic resin, and resin composition containing the same and used for aqueous coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject resin having a proper hydrophobic property without deteriorating water solubility, not whitened, and capable of forming coating films excellent in water resistance, by neutralizing an acrylic copolymer obtained from a specified monomer mixture with a neutralizing agent. SOLUTION: This water-soluble acrylic resin is obtained by neutralizing (A) an acrylic copolymer having a weight-average mol.wt. of 10,000-200,000, a glass transition temperature of 10-80 deg.C and a dissolution parameter value (turbidimetric titration) of 8.5-11.0 with (B) a neutralizing agent preferably an amine. The acrylic copolymer A is obtained by copolymerizing (i) 1-30wt.% of an alkylene oxide group-containing (meth)acrylate of the formula [R is H, methyl; R1 is H, an alkyl, an acyl; (m) is 1-200; (n) is 2, 3], (ii) 0.5-80wt.% of a cyclic saturated hydrocarbon group-having (meth)acrylate, (iii) 0-30wt.% of a hydroxyl group-containing unsaturated monomer except the component i and (iv) 0-98.5wt.% of one or more other unsaturated monomers by a method such as a solution polymerization method.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-soluble acrylic resin capable of forming a coating film having excellent water resistance without whitening, and a resin composition for water-based paint containing the same.

[0002]

2. Description of the Related Art Conventionally, organic solvent-based paints have been frequently used for coating automotive exterior panels and the like, but the use of water-based paints has been shifting from the viewpoint of air pollution and resource saving. In particular, various types of water-based basecoat paints have been proposed for finish coating in which a basecoat paint is applied and then a clear paint is applied (for example, Japanese Patent Application Laid-Open No. Sho 62-193).
676 etc.). Generally, resins such as an acrylic resin emulsion, a urethane resin emulsion, and a water-soluble acrylic resin are mainly used for the aqueous paint for the basecoat.

When a water-based paint containing the resin component is used as a room temperature drying type while forming a film, a film is formed by fusing emulsion particles, so that the resulting coating film has a state in which emulsion particles remain. When this is subjected to a water resistance test, a phenomenon in which water is localized at the interface between the emulsion particles to cause whitening is remarkably observed. Therefore, it has been considered to improve the water resistance by using a water-soluble acrylic resin in combination with a resin emulsion to connect the gaps between the emulsion particles with the water-soluble acrylic resin. It was not enough.

In order to improve the water resistance of a water-soluble acrylic resin after film formation, it is considered to impart hydrophobicity to the resin without impairing the water-solubility. Conventionally, hydrophobic resins such as monomers having long-chain alkyl groups and styrene have been proposed. Investigations have been made on using a monomer as a copolymer component. However, a monomer having a long-chain alkyl group lowers the Tg of the resin, causing deterioration in high-temperature water resistance and brittleness of the coating film. In the case of styrene, not only whitening occurs significantly during the drying process of the coating film but also In addition, there is a problem that whitening occurs even in a water resistance test after film formation.
Further, if the hydrophobicity becomes too strong, there is also a problem that lumps are liable to be produced by mixing with the pigment.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems and found that a resin obtained by copolymerizing a monomer mixture having a specific monomer composition impairs water solubility. The present invention was found to be moderately hydrophobized without reaching the present invention.

That is, the present invention provides (a) the following general formula (I):

[0007]

Embedded image

Wherein R is a hydrogen atom or a methyl group, R ₁
Is a group selected from a hydrogen atom, an alkyl group and an acyl group,
m represents an integer of 1 to 200, n represents an integer of 2 or 3) 1 to 30% by weight of an alkylene oxide group-containing (meth) acrylate represented by the formula (b) having a cyclic saturated hydrocarbon group (meth) Acrylate 0.5-80% by weight, (c)
(A) a hydroxyl group-containing unsaturated monomer other than a monomer
30% by weight, and (d) other unsaturated monomers-0 to 9
Water-soluble acrylic resin obtained by neutralizing an acrylic copolymer obtained by copolymerizing 8.5% by weight with a neutralizing agent, and a resin composition for water-based paint containing the water-soluble acrylic resin as a vehicle component Is provided.

Hereinafter, the present invention will be described in detail.

The water-soluble acrylic resin of the present invention comprises (a) an alkylene oxide group-containing (meth) acrylate represented by the above general formula (I), and (b) a cyclic saturated hydrocarbon group-containing (meth) acrylate. And (c) an acrylic copolymer obtained by copolymerizing another unsaturated monomer with a neutralizing agent.

In the alkylene oxide group-containing (meth) acrylate (a) represented by the general formula (I),
When R ₁ is an alkyl group or an acyl group, it preferably has about 1 to 8 carbon atoms, and in the formula, the number of m is preferably 1 to 200, and more preferably 10 to 100. If m exceeds 200, the copolymerizability and compatibility with other monomers decrease, which is not desirable.

Examples of the monomer (a) include diethylene glycol (meth) acrylate, triethylene glycol (meth) acrylate, and polyethylene glycol.
(Meth) acrylate, dipropylene glycol (meth) acrylate, tripropylene glycol (meth)
Acrylate, polypropylene glycol (meth) acrylate, polyethylene polypropylene glycol (meth) acrylate, methoxyethylene glycol (meth) acrylate, ethoxyethylene glycol (meth) acrylate Ethoxydiethylene glycol (meth) acrylate, ethoxytriethylene glycol (meth) acrylate, ethoxy polyethylene glycol
(Meth) acrylate, propoxytriethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, ethoxypropylene glycol (meth) acrylate, ethoxydipropylene glycol (Meth) acrylate, ethoxytripropylene glycol (meth) acrylate, ethoxy polypropylene glycol (meth) acrylate, propoxytripropylene glycol (meth) acrylate, and the like. These can be used alone or in combination of two or more.

The cyclic saturated hydrocarbon group-containing (meth) acrylate (b) includes a monocyclic hydrocarbon group, a bridged alicyclic hydrocarbon group, and a bicyclic terpene group. (Meth) acrylate, adamantyl (meth) acrylate, bicyclo [3,3,1] nonyl (meth) acrylate, cyclohexyl (meth) acrylate
And t-butylcyclohexyl (meth) acrylate, and these can be used alone or in combination of two or more. In particular, isobornyl (meth) acryle
And adamantyl (meth) acrylate are preferred.

Examples of the unsaturated monomer containing a hydroxyl group other than the monomer (a) (c) include 2-hydroxyethyl (meth) acrylate and hydroxypropyl (meth).
2-8 carbon atoms of (meth) acrylic acid such as acrylate
Hydroxyalkyl esters; N-methylolacrylamide, allyl alcohol, ε-caprolactone-modified acrylic monomer and the like, and these can be used alone or in combination of two or more.

Other unsaturated monomers (d) include:
For example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-
Propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl ( (Meth) acrylic acid alkyl esters having 1 to 24 carbon atoms, such as (meth) acrylate and lauryl (meth) acrylate; vinyl aromatic compounds such as styrene and vinyl toluene; N-vinylpyrrolidone, ethylene, butadiene , Chloroprene, vinyl propionate, vinyl acetate, (meth) acrylonitrile, glycidyl (meth) acrylate, and the like.
These can be used alone or in combination of two or more,
It is appropriately selected according to the desired performance.

In order to impart water solubility to the acrylic copolymer, it is appropriate to use an acidic group-containing monomer as a copolymer component. Examples of the monomer include (meth) acrylic acid and maleic acid. Crotonic acid, itaconic acid, β-carboxyethyl acrylate, 2-acrylamido-2-methylpropanesulfonic acid, allylsulfonic acid, sodium styrenesulfonate, sulfoethylmethacrylate and its sodium and ammonium salts And phosphoric acid group-containing monomers such as "Light Ester PM" (manufactured by Light Ester Co.).
It can be used in combination of two or more kinds. Among them, it is preferable to use at least one part having a carboxy group. It is desirable that the acidic group-containing monomer is usually contained in the monomer mixture in an amount of 10% by weight or less, preferably 0.5 to 5% by weight.

The acrylic copolymer can be obtained by copolymerizing the above monomers with a radical polymerization initiator by a usual method such as solution polymerization. Examples of the solvent used include cellosolves, alcohols, carbitols, and cellosolve acetates. Examples of the radical polymerization initiator include peroxides and azo compounds. The reaction ratio of the above monomers is determined according to the above (a) monomers 1-3.
0% by weight, preferably 5 to 20% by weight, (b) monomer
0.5-80% by weight, preferably 5-50% by weight,
The proportion of (c) monomer-0 to 30% by weight, preferably 5 to 15% by weight and (d) monomer-0 to 98.5% by weight, preferably 15 to 85% by weight is suitable. When the proportion of the monomer (a) is less than 1% by weight, the effect of hydrophilicity becomes insufficient. On the other hand, when it exceeds 30% by weight, the resulting coating film is easily dissolved in water, which is not preferable. (B) If the proportion of the monomer is less than 0.5% by weight, hydrophobization becomes insufficient, while 8
If the content exceeds 0% by weight, the film-forming properties are deteriorated, and the obtained coating film is liable to crack. On the other hand, if the proportion of the monomer (c) exceeds 30% by weight, the hydrophilicity becomes too strong, and the water resistance of the resulting coating film may be reduced.
If the proportion of the monomer exceeds 98.5% by weight, water dispersibility deteriorates, which is not preferable.

The acrylic copolymer thus obtained is:
It is suitable that the weight average molecular weight is in the range of 10,000 to 200,000, preferably 30,000 to 100,000. If the weight average molecular weight is less than 10,000, the water resistance of the resulting coating film is reduced, while if it exceeds 200,000, the viscosity is undesirably increased.

The acrylic copolymer has a glass transition temperature of -10 to 80 ° C, preferably 0 to 50 ° C. If the glass transition temperature is less than -10 ° C, the warm water resistance of the resulting coating film decreases, while if it exceeds 80 ° C, the film-forming properties deteriorate, and the resulting coating film is also liable to crack. .

Further, the above acrylic copolymer has a solubility parameter value in the range of 8.5 to 11.0, preferably 8.8 to 10.5, as determined by cloud point titration. The solubility parameter (SP) value of the copolymer here is measured by a cloud point titration which is a simple actual measurement method. W. SUH, J.M. M. CORBETT equation (Journa
l of Applied Polymer Science, 12 , 2359, 1968).

[0021]

(Equation 1)

(Where V _H is the volume fraction of n-hexane,
V _D is the volume fraction of deionized water, δ _H is the S of n-hexane
P value, [delta] _D denotes a SP value of deionized water) The turbidity point titration, dried acrylic copolymer (solid content)
While 0.5 g was dissolved in 10 ml of acetone, n-hexane was added, and the titration H (ml) at the turbid point was read. Similarly, the titration D at the turbid point of the acetone solution by adding deionized water (D ( ml), and these are applied to the following equation to calculate V _H , V _D , δ _H , and δ _D. The SP value of each solvent was 9.75 for acetone, and 9.75 for n-hexane.
7.24, deionized water: 23.43.

V _H = H / (10 + H) V _D = D / (10 + D) δ _H = 9.75 × 10 / (10 + H) + 7.24 × H /
(10 + H) δ _D = 9.75 × 10 / (10 + D) + 7.24 × D /
(10 + D) When the solubility parameter value of the acrylic copolymer is less than 8.5, the obtained coating film may be whitened, while 11.
Exceeding 0 is not preferred because the water absorption of the coating film increases and the water resistance decreases.

Examples of the neutralizing agent for neutralizing the acrylic copolymer include ammonia, amines, and basic compounds such as hydroxides and carbonates of alkali metals, and amines are particularly preferable. As the amine, primary, secondary or tertiary alkylamines, primary, secondary or tertiary alkanolamines, cycloalkylamines and the like can be used. The acidic group in the acrylic copolymer is neutralized with the neutralizing agent to obtain the water-soluble acrylic resin of the present invention.

The present invention also provides a resin composition for water-based paint containing the water-soluble acrylic resin of the present invention obtained as described above as a vehicle component.

In the composition of the present invention, the above-mentioned water-soluble acrylic resin is used as a vehicle component. If necessary, other water-soluble and / or water-soluble acrylic resins usually used as a film-forming component of a water-based paint may be added to the water-soluble acrylic resin. Alternatively, a water-dispersible resin may be appropriately selected and used in combination. Examples of such other water-soluble and / or water-dispersible resins include, for example, water-soluble or water-dispersed acrylic resins, polyurethane resins, alkyd resins, polyester resins, cellulose resins, and the like. . Among them, it is particularly preferable to use an acrylic resin emulsion and / or a urethane resin emulsion together from the viewpoint of compatibility with the water-soluble acrylic resin and physical properties of the coating film.

The content of the water-soluble acrylic resin is preferably at least 5 parts by weight, preferably within the range of 10 to 35 parts by weight, based on 100 parts by weight of the total resin solids as a vehicle component. If the content is less than 5 parts by weight, it is not preferable because the gap between the particles of the emulsion used together cannot be sufficiently connected and the water resistance of the coating film becomes insufficient.

The composition of the present invention may contain a crosslinking agent, if necessary. Examples of the crosslinking agent include water-soluble or water-dispersible amino resins, (block) polyisocyanates, epoxy resins and the like.

The composition of the present invention may further comprise a thickener, a surface conditioner, an antifoaming agent, a curing catalyst, water, an organic solvent,
Other components usually used in the preparation of aqueous paints such as color pigments and extender pigments may be blended. When blending the pigment, the water-soluble acrylic resin of the present invention may be used as a pigment dispersing resin to prepare a pigment paste.

The resin composition for a water-based paint of the present invention obtained as described above can be used, for example, in a paint finishing method in which a base paint is applied to a substrate surface and then a top clear paint is applied. It can also be used for paints or top clear paints, but is particularly preferred for use in basecoat paints. Drying of the obtained coating film can be performed under the conditions of normal temperature drying and forced drying (80 ° C. or lower), and can be applied to baking at a high temperature.

[0031]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. "Parts" and "%" in the text are "parts by weight", respectively.
And "% by weight".

Production Example 1 of Water-Soluble Acrylic Resin 58 parts of butyl cellosolve was added to a four-necked flask equipped with a stirrer, a thermometer, and a nitrogen gas inlet tube, and the mixture was heated in a nitrogen gas stream.
The temperature was raised to 7 ° C. After the temperature reached 117 ° C., 19 parts of methyl methacrylate, 22 parts of n-butyl methacrylate, 40 parts of isobornyl acrylate, and hydroxyethyl acrylate
5 parts, acrylic acid 4 parts, RMA-450M (Note 1) 1
A mixture of 0 parts and 0.3 parts of azobisisobutyronitrile was added dropwise over 3 hours. The monomer tank was washed with 11.5 parts of butyl cellosolve and combined with the reaction solution. After completion of the monomer-dropping, the mixture was further reacted for 30 minutes.
A solution consisting of 0.5 parts of azobis (2,4-dimethylvaleronitrile) and 11.5 parts of butyl cellosolve was added dropwise over 1 hour, stirred for 30 minutes, cooled to 70 ° C., and the butyl cellosolve solution of the acrylic copolymer was added. Obtained. A solution consisting of 5.6 parts of triethylamine and 7.7 parts of butyl cellosolve was added thereto, and 5.7 parts of deionized water was further added thereto to obtain a nonvolatile matter of 50.2% and a viscosity of YZ (Gadner-Foam viscometer, 25 parts). C)) to obtain a water-soluble acrylic resin solution (A-1) having an acid value of 31.

(Note 1) RMA-450M: a methacrylic resin containing polyoxyethylene (45-mer) manufactured by Nippon Emulsifier Co.
G Examples 2-6 and Comparative Examples 1-5 In Example 1, except that the monomer and catalyst composition of the acrylic copolymer were set as shown in Table 1, a water-soluble acrylic resin solution ( A-2) to (A-11)
I got Table 1 shows the property values of each resin solution and acrylic copolymer.

The water-soluble acrylic resin solution (A-1)
(A-11) was diluted with deionized water so that the non-volatile content became 30%, applied to a glass plate with an applicator of 250 nm, and dried at 60 ° C. for 1 hour. After immersing each of the obtained coated plates in water at 20 ° C. for 24 hours, the water resistance of the clear film (the presence of whitening and blisters) was visually evaluated. ○ indicates no abnormality, Δ indicates slight blistering, and × indicates whitening or blistering of the coating film. The results are shown in Table 1.

(Note 2) RMA-150M: manufactured by Nippon Emulsifier Co., Ltd., containing methacrylic acid containing polyoxyethylene (15 mer).
(Note 3) RMH-4000: Nippon Emulsifier Co., Ltd., methacrylate containing polyoxyethylene (100 mer)

[0036]

[Table 1]

Preparation of Resin Composition for Aqueous Paint Examples 7 to 13 and Comparative Examples 6 to 11 The water-soluble acrylic resin solutions (A-1) to
To (A-11), the clear components shown in Table 2 were added in the proportions shown in the same table, mixed and stirred, adjusted to pH 8.0 with triethylamine, and then added with deionized water to obtain a solid content of 4%.
0% of each of the resin compositions (B-1) to (B-13) were obtained.
In addition, the composition of Table 2 is a solid content display.

Each resin composition was applied on a glass plate using an applicator of 100 μm and dried at 60 ° C. for 1 hour. The water absorption, dissolution rate, and water resistance of each of the obtained coated plates were examined. The results are shown in Table 2. (Note 4) to (Note 6) and the test method in Table 2 are as follows.

(Note 4) Urethane resin emulsion: produced as follows.

115.5 parts of polybutylene adipate having a number average molecular weight of 2000, 115.5 parts of polycaprolactone diol having a number average molecular weight of 2000, 23.2 parts of dimethylolpropionic acid, 1,4-butanediol 6.5 parts and 1-isocyanato-3-isocyanatomethyl-
120.1 parts of 3,5,5-trimethylcyclohexane was charged into a polymerization vessel and reacted at 85 ° C. for 7 hours with stirring in a nitrogen stream to obtain a terminal NCO prepolymer having an NCO content of 4.0%. Then, the prepolymer was cooled to 50 ° C., and 165 parts of acetone was added to dissolve it uniformly. Then, 15.7 parts of triethylamine was added with stirring, and 600 parts of deionized water was added while keeping the temperature at 50 ° C. or lower. After maintaining the aqueous dispersion at 50 ° C. for 2 hours to complete the water elongation reaction, acetone was distilled off under reduced pressure at 70 ° C. or lower to obtain a solid content of 39%.
% Urethane resin emulsion was obtained.

(Note 5) Acrylic resin emulsion: produced as follows.

In a reaction vessel, 140 parts of deionized water, "New
col-707SF "(manufactured by Nippon Emulsifier Co., Ltd., surfactant,
2.5 parts of a solid content 30%) and a monomer mixture (55 parts of methyl methacrylate, 8 parts of styrene, 9 parts of n-butyl acrylate, 5 parts of 2-hydroxyethyl acrylate)
(1 part of 1,6-hexanediol diacrylate and 1 part of methacrylic acid) were added, and the mixture was stirred and mixed in a nitrogen stream, and 3 parts of 3% ammonium persulfate was added at 60 ° C.
Then, the temperature was raised to 80 ° C., and the remaining 79 parts of the monomer mixture, 2.5 parts of “Newcol-707SF”, 3%
A pre-emulsion consisting of 4 parts of ammonium persulfate and 42 parts of deionized water was added to the reaction vessel over 4 hours using a metering pump, and the mixture was aged for 1 hour after the addition was completed.

Further, at 80 ° C., a monomer mixture (5 parts of methyl methacrylate, 7 parts of n-butyl acrylate, 5 parts of 2-ethylhexyl acrylate, 3 parts of methacrylic acid and “Newcol-707SF”) "0.5 parts)
20.5 parts and 4 parts of 3% ammonium persulfate were simultaneously dropped in parallel over 1.5 hours, aged for 1 hour after the addition was completed, diluted with 30 parts of deionized water, and dried at 30 ° C. with 200 mesh nylon cloth. Filtered. Deionized water was further added to the filtrate, and the pH was adjusted to 7.5 with triethylamine.
An acrylic resin emulsion having an average particle size of 0.1 μm and a solid content of 20% was obtained.

(Note 6) Surface conditioner: “BYK-03
4 ", manufactured by Big Chem Co., Ltd. (Test method)-Water absorption: The clear coating film was peeled off from each coated plate, immersed in water at 20 ° C. for 6 days, and the weight (W ₁ ) was measured. Then, the weight (W ₂ ) of the clear coating after drying at 105 ° C. for 1 hour was measured, and the water absorption (%) of each clear coating was calculated from the difference in weight.

Water absorption (%) = (W ₁ −W ₂ ) / W ₂ × 100 Elution rate: The clear coating film was peeled off from each coated plate, and the weight (W ₀ ) was measured. After immersion in tap water for 6 days, the weight (W ₂ ) after drying at 105 ° C. for 1 hour was measured, and the dissolution rate (%) of each clear coating film was calculated according to the following formula.

Dissolution rate (%) = {1- (W ₂ / W ₀ )} × 100 Water resistance: After immersing each coated plate in tap water at 30 ° C. for 6 hours, the water resistance (whitening) of the clear film was obtained. And the presence of blisters) were visually evaluated.は indicates no abnormality, △ indicates slight blistering, and × indicates whitening or blistering of the coating film.

[0047]

[Table 2]

Preparation of aqueous basecoat paints Examples 14 to 20 and Comparative Examples 12 to 17 Aluminum pigment paste "Alpe" was added to a stirring and mixing vessel.
17 parts of "ST N7680" (manufactured by Toyo Aluminum Co., Ltd.) and 20 parts of butyl cellosolve were added, and 1 part of a general-purpose phosphoric acid group-containing treating agent was added with stirring and mixing, followed by stirring for 1 hour to obtain an aluminum pigment concentrated liquid.

The aluminum pigment concentrate obtained above and the resin compositions (B-1) to (B-13) obtained above were added in the combinations and formulations shown in Table 3, and stirring was continued for 1 hour. The pH of the resulting mixture was adjusted to 8.0 with triethylamine, and then deionized water was added to obtain an aqueous base having a solid content of 15%.
Paint was obtained. Table 3 shows the solid content.

Paint test Commercially available lacquer on a 300 × 100 × 0.8 mm mild steel plate
The primer surfacer was coated with a dry film thickness of 40 μm, dried at room temperature for 30 minutes, and polished with # 400 water-resistant abrasive paper to obtain a coated plate. On the plate to be coated, a coating film of "TC-71 Clear" (manufactured by Kansai Paint Co., Ltd., aminoacrylic resin) was formed as an old coating film of an automobile outer panel, and the aqueous base obtained above was formed thereon. A coat paint was applied with a spray gun to a dry film thickness of 15 μm, and allowed to stand for 10 minutes.
After forced drying at 0 ° C. for 10 minutes, “Rethane PG2KM
"Clear" (urethane-cured clear, manufactured by Kansai Paint Co., Ltd.) was applied with a spray gun so as to have a dry film thickness of 40 to 50 [mu] m, and was forcibly dried at 60 [deg.] C. for 20 minutes to obtain each test coated plate.

The obtained test coated plate was subjected to the following performance tests. Table 3 shows the results.

(1) Adhesion: Each coated plate was placed in water at 20 ° C. for 7 minutes.
After dipping for a day and taking out, the coating film was cross-cut so as to reach the base material, and an adhesive cellophane tape was stuck to the coated surface and the coated film surface after strong peeling was evaluated (（: no peeling,
Δ: slight peeling, ×: significant peeling).

(2) Water resistance: Each coated plate was immersed in a constant temperature water bath at 40 ° C. for 10 days, taken out, and left standing for 1 hour to visually evaluate the state of the coating film. (○: No abnormality, ×: Glossy, blistering)

[0054]

According to the present invention, a water-soluble acrylic resin which is appropriately hydrophobized without impairing the water-solubility by copolymerizing a monomer mixture having a specific monomer composition can be obtained. By using the resin composition for an aqueous coating, a coating film having excellent water resistance can be formed without whitening. The resin composition for a water-based paint of the present invention is particularly useful for a water-based basecoat.

[0055]

[Table 3]

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[Procedure amendment]

[Submission date] May 12, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0022

[Correction method] Change

[Correction contents]

In the above-mentioned cloud point titration, 0.5 g of dried resin composition (solid content) is dissolved in 10 ml of acetone, and n-hexane is added thereto. The titration amount of n-hexane at the cloud point is H (ml). , And the titration amount of deionized water at the turbid point by adding deionized water to the acetone solution in the same manner D
(Ml), and V _H , V _D , δ _H , δ _D used in the above equation are calculated from the titer amounts by the following equation. Here, V _H is the volume fraction of n-hexane, V
_D represents the volume fraction of deionized water. In addition, SP of each solvent
The values are acetone: 9.75, n-hexane: 7.24, and deionized water: 23.43.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0023

[Correction method] Change

[Correction contents]

V _H = H / (10 + H) V _D = D / (10 + D) δ _H = 9.75 × 10 / (10 + H) + 7.24 × H /
(10 + H) δ _D = 9.75 × 10 / (10 + D) + 23.43 × D
/ (10 + D) If the solubility parameter of the acrylic copolymer is less than 8.5, the resulting coating film may be whitened, while 11.0
Exceeding the water content is not preferred because the water absorption of the coating film increases and the water resistance decreases.

Claims (4)

[Claims] (A) The following general formula (I): (Wherein, R is a hydrogen atom or a methyl group, R ₁ is a hydrogen atom,
M is a group selected from an alkyl group and an acyl group;
An integer of 0, and n represents an integer of 2 or 3) alkylene oxide group-containing (meth) acrylates 1 to 30
(B) 0.5-80% by weight of (meth) acrylate having a cyclic saturated hydrocarbon group, (c) (a) monomer
Of a hydroxyl group-containing unsaturated monomer other than 0 to 30% by weight and (d) another unsaturated monomer of 0 to 98.5% by weight are neutralized with a neutralizing agent. Water-soluble acrylic resin obtained by 2. An acrylic copolymer having a weight average molecular weight of 1
Glass transition temperature of -10 to 20,000 to 200,000
The water-soluble acrylic resin according to claim 1, which is at -80C. 3. An acrylic copolymer having a solubility parameter value of 8.5 to 11.0 by a cloud point titration.
Or the water-soluble acrylic resin according to 2. (A) the following general formula (I): (Wherein, R is a hydrogen atom or a methyl group, R ₁ is a hydrogen atom,
M is a group selected from an alkyl group and an acyl group;
An integer of 0, and n represents an integer of 2 or 3) alkylene oxide group-containing (meth) acrylates 1 to 30
(B) 0.5-80% by weight of (meth) acrylate having a cyclic saturated hydrocarbon group, (c) (a) monomer
Of a hydroxyl group-containing unsaturated monomer other than 0 to 30% by weight and (d) another unsaturated monomer of 0 to 98.5% by weight are neutralized with a neutralizing agent. A resin composition for water-based paint, comprising a water-soluble acrylic resin obtained as a vehicle component.