JP2003096264A - Water-based high solid thermoset resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a water-based high solid thermoset resin composition using a high solid emulsion resin suitable for a binder having thermosetting properties. SOLUTION: The water-based high solid thermoset resin composition comprises the high slid emulsion resin and a curing agent and has a viscosity of 30-10,000 mPa.s as measured by an E-type viscometer at 1 rpm (25 deg.C) and a solid content of 55-65 wt.%. The high-solid emulsion resin comprises two types of resin particles having different volume average particle sizes that are obtained by emulsion polymerization of an α,β-ethylenically unsaturated monomer mixture having a hydroxy value of 10-150 and an acid value of 5-50. The first resin particle has a larger volume average particle size compared with that of the second resin particle. The first resin particle has a volume average particle size of 0.2-1.5 μm, and the second resin particle has a volume average particle size of 0.05-0.4 μm.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an aqueous thermosetting resin composition, and more particularly to an aqueous high solid type thermosetting resin composition.

[0002]

2. Description of the Related Art In recent years, in order to reduce the amount of an organic solvent contained in a resin composition used for a paint in consideration of the influence on the environment, a water-based method has been studied. However, in particular, the thermosetting resin composition has a problem that water as a solvent is less likely to be volatilized at a high humidity and bumps at a low humidity, which is easily affected by the humidity in the drying step. If it is possible to highly solidify this aqueous thermosetting resin composition, it is expected to solve these problems and effectively reduce the load on the environment. High solidification of such an aqueous resin composition is generally performed by making an emulsion resin, which is a binder thereof, into a high solid. Hitherto, the method for producing a highly solid emulsion resin is described in, for example, Japanese Patent Application Laid-Open No. 10-17841 and Japanese Patent Application Laid-Open No. 2001-139610. However, most of the emulsion resins described in these publications were designed as binders for pressure-sensitive adhesives, and they could not be used as they were as binders for thermosetting resin compositions.

[0003]

An object of the present invention is to obtain an aqueous high solid type thermosetting resin composition by using a high solid type emulsion resin suitable as a binder having a thermosetting property.

[0004]

The water-based high solid type thermosetting resin composition of the present invention has an E type viscometer of 1 rpm (25
A high solid type emulsion resin having a viscosity of 30 to 10,000 mPa · s at a temperature of 50 ° C.) and a solid content of 55 to 65% by weight at that time, and a water-based resin composition containing a curing agent, wherein The solid emulsion resin contains two kinds of resin particles having different volume average particle diameters, which are obtained by emulsion polymerization of a mixture of α, β-ethylenically unsaturated monomers having a hydroxyl value of 10 to 150 and an acid value of 5 to 50. The volume average particle diameter of the first resin particles is larger than the volume average particle diameter of the second resin particles, and the volume average particle diameter of the first resin particles is 0.2 to
The second resin particles are characterized by having a volume average particle diameter of 1.5 μm and a volume average particle diameter of 0.05 to 0.4 μm. Here, the weight ratio of the first resin particles and the second resin particles may be 0.4 to 4.0. In addition, the high-solid type emulsion resin contains the first resin particles and the second resin particles.
It may be obtained by mixing with the resin particles described in 1. or may be obtained by two-step emulsion polymerization.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The aqueous high-solid type thermosetting composition of the present invention contains a high-solid type emulsion resin and a curing agent. The above-mentioned high solid emulsion resin has a hydroxyl value of 10 to 150 and an acid value of 5 to 50 of α and β.
-It contains two types of resin particles having different volume average particle diameters obtained by emulsion polymerization of an ethylenically unsaturated monomer mixture, and the volume average particle diameter of the first resin particles is the second resin particles. Larger than the volume average particle size of
The volume average particle diameter of the first resin particles is 0.2 to 1.5 μm.
m, the volume average particle diameter of the second resin particles is 0.05 to 0.
It is 4 μm. The term "high solid" as used herein means that the solid content is high at a viscosity that can be used as a binder for paints. Specifically, for example, the viscosity at 1 rpm of the E-type viscometer at 25 ° C. is 3
When it is 0 to 10000 mPa · s, the solid content is 55 to 65% by weight. However, the above definition of viscosity is
It is not limited to using the E-type viscometer, and includes those having substantially the same range by using other similar measuring means. The solid content is generally 60 at 150 ° C.
It can be determined from the residue obtained by heating for minutes.

The above high solid type emulsion resin is
It contains two types of resin particles having different particle sizes. The volume average particle diameter of the first resin particles is larger than the volume average particle diameter of the second resin particles. The volume average particle diameter of the first resin particles is 0.2 to 1.5 μm,
The volume average particle diameter of the resin particles is 0.05 to 0.4 μm. Outside of these ranges, the desired high solidification cannot be achieved. Preferably, the volume average particle diameter of the first resin particles is 0.3 to 1 μm, and the volume average particle diameter of the second resin particles is 0.08 to 0.35 μm. The volume average particle diameter (hereinafter sometimes referred to as particle diameter) in the present invention can be obtained by using a general measuring means such as laser light scattering.

The weight ratio of the first resin particles to the second resin particles in the high solid emulsion resin is preferably 0.4 to 4.0. If it is less than 0.4, the viscosity of the resin becomes high and handling becomes difficult, resulting in 4.0.
If it exceeds, the stability of the resin is lowered and aggregation easily occurs. A more preferable weight ratio is 0.6 to 3, and particularly preferably 1 to 3.

The high solid type emulsion resin is produced by emulsion polymerization of a mixture of α, β-ethylenically unsaturated monomers. here,
The α, β-ethylenically unsaturated monomer mixture has a hydroxyl value of 10 to 150 and an acid value of 5 to 50. If the hydroxyl value is less than 10, the curability may be insufficient, and if it exceeds 150, the water resistance of the resulting coating film may be reduced. The preferred hydroxyl value is 20 to 100, and more preferably 40 to 80. On the other hand, if the acid value of the α, β-ethylenically unsaturated monomer mixture is less than 5, the stability of the high solid type emulsion resin may decrease, and if it exceeds 50, the water resistance of the resulting coating film may decrease. The preferred acid value is 7
It is -30, more preferably 10-20.

The solubility parameter of the α, β-ethylenically unsaturated monomer mixture is preferably 9.0 to 12.0. If it is less than 9.0, the monomer is not solubilized, so that the solubilization of the monomer oil droplets into the micelle, which is the reaction field, does not occur and the reaction does not proceed. Further, when it exceeds 12.0, the water solubility of the produced polymer becomes high, and as a result,
The resulting emulsion has low particle properties. A more preferred solubility parameter is 9.5 to 11.5. The solubility parameter can be determined by a method well known to those skilled in the art, such as the turbidity method, and the α, β-ethylenically unsaturated monomer constituting the α, β-ethylenically unsaturated monomer mixture can be obtained. It is also possible to calculate using the solubility parameter which each has based on the composition ratio of.

Further, the glass transition temperature of the polymer obtained by copolymerizing the above α, β-ethylenically unsaturated monomer mixture is −30 to 80 ° C. in terms of mechanical properties of the obtained coating film. Is more preferable, and it is more preferable that the temperature is -20 to 40 ° C.

The above α, β-ethylenically unsaturated monomer mixture can have the above acid value and hydroxyl value by containing therein an α, β-ethylenically unsaturated monomer having an acid group or a hydroxyl group. .

Examples of the α, β-ethylenically unsaturated monomer having an acid group include acrylic acid, methacrylic acid, acrylic acid dimer, crotonic acid, 2-acryloyloxyethyl phthalic acid and 2-acryloyloxyethyl succinic acid. , Ω-carboxy-polycaprolactone mono (meth)
Acrylate, isocrotonic acid, α-hydro-ω-
((1-oxo-2-propenyl) oxy) poly (oxy (1-oxo-1,6-hexanediyl)), maleic acid, fumaric acid, itaconic acid, 3-vinylsalicylic acid,
Examples thereof include 3-vinylacetylsalicylic acid, 2-acryloyloxyethyl acid phosphate, and 2-acrylamido-2-methylpropanesulfonic acid. Among these, preferred are acrylic acid, methacrylic acid, and acrylic acid dimer.

On the other hand, as the α, β-ethylenically unsaturated monomer having a hydroxyl group, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate,
Examples thereof include hydroxybutyl (meth) acrylate, allyl alcohol, methacrylic alcohol, and an adduct of hydroxyethyl (meth) acrylate and ε-caprolactone. Preferred among these are hydroxyethyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxyethyl (meth) acrylate and ε.
An adduct with caprolactone.

Furthermore, the above α, β-ethylenically unsaturated monomer mixture may contain other α, β-ethylenically unsaturated monomers. Examples of the other α, β-ethylenically unsaturated monomers include (meth) acrylic acid esters (for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and (meth) acrylic). Isopropyl acid, (meth) acrylic acid n-
Butyl, isobutyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl methacrylate, phenyl acrylate,
(Meth) acrylic acid isobornyl, cyclohexyl methacrylate, (meth) acrylic acid t-butylcyclohexyl, (meth) acrylic acid dicyclopentadienyl, (meth) acrylic acid dihydrodicyclopentadienyl, etc.),
Polymerizable amide compound (for example, (meth) acrylamide, N-methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-dibutyl (meth) acrylamide, N , N-dioctyl (meth) acrylamide, N-monobutyl (meth) acrylamide, N-monooctyl (meth) acrylamide 2,4-dihydroxy-4′-vinylbenzophenone, N- (2-hydroxyethyl) acrylamide, N- ( 2-hydroxyethyl) methacrylamide, etc.), a polymerizable aromatic compound (for example, styrene, α-methylstyrene, vinyl ketone,
t-butylstyrene, parachlorostyrene, vinylnaphthalene, etc.), polymerizable nitriles (eg, acrylonitrile, methacrylonitrile, etc.), α-olefins (eg, ethylene, propylene, etc.), vinyl esters (eg, vinyl acetate, propionic acid). Vinyl, etc.), dienes (eg, butadiene, isoprene, etc.), polymerizable aromatic compounds, polymerizable nitriles, α-olefins, vinyl esters, and dienes. These can be selected according to the purpose. In addition, in this specification, a (meth) acrylic acid ester shall mean both an acrylic acid ester and a methacrylic acid ester.

When the α, β-ethylenically unsaturated monomer mixture contains a (meth) acrylic acid ester, the ester moiety such as methyl (meth) acrylate and ethyl (meth) acrylate has 1 or 2 carbon atoms. (Meta)
The coating film appearance can be improved by containing 65% by weight or more of the acrylic ester. This is because the (meth) acrylic acid ester in which the ester part has 1 or 2 carbon atoms has a high solubility parameter, and by using these in a specific amount or more, it can be obtained without causing problems such as water resistance. It is thought that this is because the hydrophilicity of the resin to be used is increased, and this improves the compatibility with water.
In order for the high solid type emulsion resin obtained by emulsion-polymerizing the ethylenically unsaturated monomer mixture to contain two types of resin particles having different particle diameters, the following two methods can be mentioned.

The first method is a method of mixing the first resin particles and the second resin particles. In this method, a first emulsion resin containing the first resin particles and a second emulsion resin containing the second resin particles are first produced by separate emulsion polymerization, and these two types of emulsion resins are mixed. After that, the aqueous medium is distilled off. The emulsion polymerization for obtaining the first emulsion resin and the second emulsion resin can be carried out by using a well-known method. Specifically, the emulsifier is dissolved in water or an aqueous medium containing an organic solvent such as alcohol as necessary, and the α, β-ethylenically unsaturated monomer and the polymerization initiator are added dropwise under heating and stirring. It can be done by An α, β-ethylenically unsaturated monomer which has been previously emulsified with an emulsifier and water may be added dropwise in the same manner.

Suitable polymerization initiators include azo oily compounds (eg, azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile)).
And 2,2′-azobis (2,4-dimethylvaleronitrile), etc., and aqueous compounds (for example, anionic 4,4′-azobis (4-cyanovaleric acid), 2,2
-Azobis (N- (2-carboxyethyl) -2-methylpropionamidine and cationic 2,2'-azobis (2-methylpropionamidine)); and redox oily peroxide (e.g., benzoyl peroxide) , Parachlorobenzoyl peroxide, lauroyl peroxide and t-butyl perbenzoate), and aqueous peroxides such as potassium persulfate and ammonium persulfate.

As the emulsifier, those usually used by those skilled in the art may be used, but reactive emulsifiers such as Antox MS-60 (manufactured by Nippon Emulsifier Co., Ltd.), Eleminol JS-2 (Sanyo Chemical Co., Ltd.). Company), ADEKA rear soap NE-20 (manufactured by Asahi Denka Co., Ltd.) and Aqualon HS-
10 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and the like are particularly preferable.

Further, in order to control the molecular weight, a mercaptan such as lauryl mercaptan and a chain transfer agent such as α-methylstyrene dimer may be used if necessary.

The reaction temperature is determined by the initiator, and for example, it is preferably 60 to 90 ° C. for the azo type initiator and 30 to 70 ° C. for the redox type. In general,
The reaction time is 1 to 8 hours. The amount of the initiator, based on the total amount of the α, β-ethylenically unsaturated monomer mixture, is generally 0.1 to 5% by weight, preferably 0.2 to 2% by weight.
Is.

Respective α, β-ethylenically unsaturated monomers used in emulsion polymerization to obtain the first emulsion resin containing the first resin particles and the second emulsion resin containing the second resin particles. The mixtures may have different compositions, but the same composition is preferred. Also, monomer composition, emulsifier type,
The volume average particle diameter can be set within a predetermined range by adjusting the particle size controlling factors such as the amount of the emulsifier and the distribution of the emulsifier.

Distillation of the aqueous medium, which is carried out after the first and second emulsion resins are mixed, can usually be carried out under reduced pressure at 50 to 80 ° C. By distilling off the aqueous medium, the solid content is adjusted within a target range.

The volume average particle diameters of the first resin particles and the second resin particles in the high solid emulsion resin obtained by this method are the same as the volume average particle diameters of the resin particles contained in the first and second emulsion resins. It is the value which measured each particle diameter. The weight ratio of the first resin particles and the second resin particles is such that the weight of the first and second emulsion resins used for mixing and the resin contained in the first and second emulsion resins. It can be calculated from the solid content of the particles.

The second method is to directly produce a high solid emulsion resin containing the first resin particles and the second resin particles by a two-step emulsion polymerization. In this case, in order to make a difference in particle size between the first stage and the second stage, the emulsifier species, the amount of the emulsifier, and the distribution of the emulsifier charged are adjusted and selected. Either of the first resin particles and the second resin particles may be manufactured first.

In the above two-step emulsion polymerization, basically, the contents relating to the emulsion polymerization described in the first method can be applied as they are, except that the polymerization is carried out in two steps. Also,
The α, β-ethylenically unsaturated monomer mixture used in the first stage and the second stage may have different compositions, but the same composition is preferable in terms of design.

In the case of the high solid type emulsion resin obtained by the second method, the particle size distribution has two peaks. “Containing two types of resin particles having different particle sizes” includes those having such a particle size distribution. In this case, the volume average particle diameters of the first resin particles and the second resin particles are peak values in the particle size distribution. Further, the weight ratio of the first resin particles and the second resin particles is defined by the weight ratio of the α, β-ethylenically unsaturated monomer mixture used in the first step and the second step. Moreover, the volume average particle diameter of the first resin particles and the second resin particles when the presence of three or more peaks is recognized after excluding what is called a so-called shoulder peak is the most within each range. The peak value has high intensity.

The curing agent contained in the aqueous high-solid type thermosetting resin composition of the present invention is not particularly limited as long as it reacts with a hydroxyl group and / or a carboxyl group. As such, amino resins, blocked isocyanates, epoxy compounds, aziridine compounds,
A carbodiimide compound, an oxazoline compound, a metal ion, etc. are mentioned. Amino resins and / or blocked isocyanates are generally used from the viewpoints of various properties and cost of the obtained cured film.

The amino resin as the curing agent is not particularly limited, and a water-soluble melamine resin or a water-insoluble melamine resin can be used. In addition, it is preferable in terms of stability to use a melamine resin having a water tolerance of 3.0 or more. The water tolerance used here is for evaluating the degree of hydrophilicity, and the higher the value, the higher the hydrophilicity. The water tolerance measurement method is 100 m at 25 ° C.
In a beaker, 0.5 g of sample is added to 10 ml of acetone.
Ion-exchanged water is gradually added using a burette to measure the amount (ml) of ion-exchanged water required until the mixture becomes cloudy. It is a tolerance value.

The above-mentioned blocked isocyanate can be obtained by adding a blocking agent having active hydrogen to polyisocyanate such as trimethylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, and the like. Examples thereof include those in which the blocking agent dissociates to generate an isocyanate group.

The aqueous high-solid type thermosetting resin composition of the present invention may contain other binder as a component other than the high-solid type emulsion resin and the curing agent. Other binders are not particularly limited, and binders such as acrylic resins, polyester resins, alkyd resins, epoxy resins and urethane resins can be used.

The above other binders have a number average molecular weight of 3,000 to 50,000, preferably 6,000 to 3
It is preferably 0000. If it is less than 3000, workability and curability during film formation are not sufficient, and
If it exceeds 0, the non-volatile content becomes too low, and the workability at the time of film formation is rather deteriorated.

The above binder is 10 to 100, and further 2
It preferably has an acid value of 0 to 80, and when it exceeds the upper limit, the water resistance decreases, and when it is less than the lower limit, the water dispersibility of the resin decreases. Further, it preferably has a hydroxyl value of 20 to 180, more preferably KOH / g. When it exceeds the upper limit, water resistance is lowered, and when it is lower than the lower limit, curability is lowered.

Further, in addition to the above-mentioned components, additives usually added to pigments and paints, for example, surface modifiers, viscosity control agents, thickeners, antioxidants, UV inhibitors, defoamers and the like are included. May be.

The proportions of these constituent components in the aqueous high solid type thermosetting resin composition of the present invention are as follows. That is, the mixing ratio of the emulsion resin and the other binder is 5 to 95% by weight of the emulsion resin, preferably 1 based on the total resin solid content.
It is 0 to 85% by weight, more preferably 20 to 70% by weight, and other binders are 95 to 5% by weight, preferably 90 to 15% by weight, more preferably 80 to 30% by weight. If the proportion of the emulsion resin is less than 5% by weight, the workability is deteriorated, and if it exceeds 95% by weight, the film-forming property may be deteriorated.

On the other hand, the curing agent is a resin solid content of 10 in the composition.
It is preferably 20 to 100 parts by weight with respect to 0 parts by weight. If it is outside the above range, the curability will be insufficient. When a pigment is included, the total pigment concentration is 0.1 to 5 in PWC.
It is preferably 0%. More preferably, 0.5
-40%, and particularly preferably 1.0-30%. If the upper limit is exceeded, the appearance will deteriorate. The other components can be set within the range known to those skilled in the art.

The production of the aqueous high-solid type thermosetting resin composition of the present invention is not particularly limited, and any method known to those skilled in the art such as mixing the above components can be used.

The aqueous high-solid type thermosetting resin composition of the present invention can be applied to various base materials such as metal and heated under predetermined conditions to obtain a cured film. The temperature and time are 80 to 200 ° C. and 1 to 60.
It is possible to select an appropriate one from the minutes.

Production Example 1 High solid type emma by mixing
Production of emulsion resin A < Production of emulsion resin 1> Styrene 20.0 parts, methyl methacrylate 26.2 parts, 2-ethylhexyl acrylate 43.0 parts, 2-hydroxyethyl methacrylate 9.3 parts, and methacrylic acid. 1.5 parts α, β-
Ethylenically unsaturated monomer mixture (hydroxyl value: 40, acid value: 10, solubility parameter: 9.75, glass transition temperature: 0 ° C.) was added to Newcol 506 (manufactured by Nippon Emulsifier Co., Ltd. polyoxyethylene nonylphenyl ether, A pre-emulsion was prepared by adding 1.5 parts of the active ingredient (65%) to an aqueous solution prepared by dissolving 50.0 parts of ion-exchanged water and emulsifying. 35.2 parts of deionized water were put into a suitable reaction vessel equipped with a thermometer, a condenser, and a stirrer, and heated to 80 ° C. Then, the pre-emulsion and an aqueous solution prepared by dissolving 0.3 part of ammonium sulfate in 15.0 parts of ion-exchanged water were simultaneously added dropwise from separate containers, and the pre-emulsion was 120 minutes and the aqueous solution of ammonium persulfate was added. The dropping was completed in 150 minutes. Thereafter, the temperature was maintained at 80 ° C. for 2 hours to obtain emulsion resin 1. Emulsion resin 1 obtained at this time
Has a volume average particle diameter of 0.647 μm and a resin solid content of 49.
4% by weight, at this time, E-type viscometer 1 rpm (25 ° C)
The viscosity measured by using was 45 mPa · s. In addition, including the following, the volume average particle diameter is measured by a laser light scattering method using LB-500 manufactured by Horiba Ltd., and as the E-type viscometer, R-10 manufactured by Toki Sangyo Co., Ltd.
A 0 type viscometer was used.

<Production of Emulsion Resin 2> In the production of Emulsion Resin 1, instead of 1.5 parts of Newcol 506 used for producing the pre-emulsion, Perex SSH (Kao Corporation sodium alkyl diphenyl ether disulfonate, active ingredient) was used. Emulsion resin 2 was obtained in the same manner except that 1.0 part of 50%) was used. The volume average particle diameter of this emulsion resin is 0.1.
02 μm, resin solid content 50.0% by weight, at this time, E
The viscosity measured using a mold viscometer 1 rpm (25 ° C.) was 3456 mPa · s.

<Mixing> 50.0 parts of Emulsion Resin 1 and 50.0 parts of Emulsion Resin 2 were mixed and heated to 65 ° C. under reduced pressure for dehydration operation. The resin solid content of the obtained high solid type emulsion resin A was 60.9% by weight, and at this time, E type viscometer 1 rpm (25 ° C.)
The viscosity measured by using was 1664 mPa · s. In the measurement of the volume average particle diameter by the laser light scattering method, a curve having two peaks at 0.131 μm and 0.510 μm was obtained.

Production Example 2 Hyso by two-step emulsion polymerization
Production of Lid Emulsion Resin B Consists of 5.0 parts of styrene, 18.0 parts of methyl methacrylate, 21.6 parts of 2-ethylhexyl acrylate, 4.6 parts of 2-hydroxyethyl methacrylate and 0.8 parts of methacrylic acid. α, β-ethylenically unsaturated monomer mixture (hydroxyl value: 40, acid value: 10, solubility parameter: 9.
94, glass transition temperature: 0 ° C), ADEKA REASOAP N
Pre-emulsion 1 is prepared by adding 0.63 parts of E-20 (polyoxyethylene nonylphenyl ether manufactured by Asahi Denka Co., Ltd., active ingredient 80%) to an aqueous solution prepared by dissolving 20.0 parts of ion-exchanged water and emulsifying the mixture. did. Separately from this, the same α, β-ethylenically unsaturated monomer mixture as in Pre-emulsion 1 was added to Aqualon HS-10 (Daiichi Kogyo Seiyaku Co., Ltd. polyoxyethylene alkylphenyl ether sulfonic acid ammonium salt, active ingredient 97).
% Or more) 0.52 parts was added to an aqueous solution prepared by dissolving 20.0 parts of ion-exchanged water and emulsified to prepare a pre-emulsion 2.

In a suitable reaction vessel equipped with a thermometer, a cooler, and a stirrer, 17.0 parts of deionized water was placed and heated to 80 ° C., and the pre-emulsion 1 was added dropwise over 60 minutes, and then continued. Pre-emulsion 2 was added dropwise in 60 minutes. Simultaneously with the dropping of the pre-emulsion 1, the dropping of an aqueous solution of 0.3 parts of ammonium persulfate dissolved in 10.0 parts of ion-exchanged water was started and ended after 150 minutes. Then, by holding at 80 ° C. for 2 hours, a high solid type emulsion resin B was obtained. The resin solid content of this emulsion resin was 59.1% by weight, and at this time, the viscosity measured using an E-type viscometer 1 rpm (25 ° C.) was 54.
It was mPa · s. The volume average particle diameter measured by the laser light scattering method was 0.259 μm and 1.005 μm.
A curve with two peaks at μm and was obtained.

Production Example 3 Hyso by two-step emulsion polymerization
Production of Lid-type Emulsion Resin C In the Production Example 2, the α, β-ethylenically unsaturated monomer mixture used was 5.0 parts of styrene, 3.7 parts of methyl methacrylate, 35.9 parts of ethyl acrylate, and methacrylic acid. 2-hydroxyethyl 4.6 parts, methacrylic acid 0.8
A high solid type emulsion resin C was obtained by performing the synthesis in the same manner except for the parts. The resin solid content of this emulsion was 59.9% by weight, and at this time, the viscosity measured using an E-type viscometer 1 rpm (25 ° C.) was 35 m.
It was Pa · s. The volume average particle diameter measured by the laser light scattering method was 0.339 μm and 0.877 μm.
A curve with two peaks at m and was obtained.

Example 1 Aqueous high solid type thermosetting resin
110 parts of the high solid type emulsion resin A obtained in Production Example 1 of the manufacturer of the fat composition, 10 parts of ion-exchanged water, 0.7 part of dimethylaminoethanol, Cymel 204 as a curing agent (mixed alkyl produced by Mitsui Cytec Co., Ltd. A water-based high-solid type thermosetting resin composition was obtained by mixing 27 parts of a synthetic melamine resin and water tolerance (3.4 ml).

Examples 2 and 3 Aqueous high solid type heat
In the same manner as in Production Example 1 of Curable Composition, except that the high solid emulsion resin B or C obtained in Production Example 2 was used as the high solid emulsion instead of the high solid emulsion resin A. A water-based high solid type thermosetting resin composition was obtained.

Comparative Example 1 Production of Aqueous Thermosetting Resin Composition In Example 1, the high solid emulsion resin A was used.
A water-based thermosetting resin composition was obtained by the same method except that the emulsion resin 1 obtained in Production Example 1 was used instead of.

<Formation of Hardened Film> Ford cup No. 3 was formed on a steel plate having a black coating film on the surface and having a thickness of 0.8 mm, a length of 30 cm, and a width of 40 cm. 4, the viscosity was adjusted using ion-exchanged water at 20 ° C. for 45 seconds.
Each of the water-based thermosetting resin compositions prepared in Example 3 and Comparative Example 1 was spray-coated to a dry film thickness of 20 μm in a high humidity environment at a temperature of 25 ° C. and a humidity of 85%.
It heated at 30 degreeC for 30 minutes, and obtained the cured film. The appearance of the cured film was evaluated by measuring the sharpness of the coating film using a portable sharpness glossiness meter PGD-IV (manufactured by Tokyo Koden Co., Ltd.). If the value is 0.8 or more, it is acceptable, and the larger the value, the better the appearance. The results are shown in Table 1 together with the solid content of each resin composition measured after adjusting the viscosity.

[0048]

[Table 1]

The water-based high solid type thermosetting resin compositions of Examples 1 to 3 contain a high solid type emulsion resin containing two kinds of resin particles having different volume average particle diameters, and therefore, ordinary emulsions are used. It has a higher solid content than the water-based thermosetting resin composition of Comparative Example 1 containing Resin 1. Furthermore, the high-solid type emulsion resin has a (meth) having 1 or 2 carbon atoms in the ester portion.
The aqueous high-solid type thermosetting resin composition of Example 3, which was obtained by emulsion polymerization of an α, β-ethylenically unsaturated monomer mixture containing 65% by weight or more of an acrylic ester, had a different appearance. It is superior to the ones.

[0050]

INDUSTRIAL APPLICABILITY In the present invention, a high solid type aqueous thermosetting resin composition is obtained by using a high solid type emulsion resin which has a specific value such as a hydroxyl value and is suitable as a binder having a thermosetting property. Was given.

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Claims (4)

[Claims] 1. A high solid type emulsion resin having a viscosity of 30 to 10,000 mPa · s at 1 rpm (25 ° C.) of E type viscometer and a solid content of 55 to 65% by weight, and a curing agent. An aqueous resin composition comprising:
The high solid emulsion resin has a hydroxyl value of 10
Of 150 to 150 and an acid value of 5 to 50, which is obtained by emulsion polymerization of an α, β-ethylenically unsaturated monomer mixture, and contains two kinds of resin particles having different volume average particle diameters. The volume average particle diameter of the resin particles is larger than the volume average particle diameter of the second resin particles, and the volume average particle diameter of the first resin particles is 0.2 to 1.5 μm. Has a volume average particle diameter of 0.05 to 0.4 μ.
m is a water-based high solid type thermosetting resin composition. 2. The water-based high solid type thermosetting resin composition according to claim 1, wherein the weight ratio of the first resin particles and the second resin particles is 0.4 to 4.0. 3. The high solid type emulsion resin,
The water-based high solid thermosetting resin composition according to claim 1 or 2, which is obtained by mixing the first resin particles and the second resin particles. 4. The high solid emulsion resin,
It is obtained by a two-step emulsion polymerization.
The water-based high solid type thermosetting resin composition according to any one of 3 above.