JPS59136361A - Aqueous coating material composition - Google Patents

Abstract

PURPOSE:The titled composition, containing an aqueous resin, e.g. polyester resin, and fine paticles of a specific water-insoluble resin having a double structure in a specific amount as a binder component, having improved workability, storage stability, durability and coating performance, e.g. pinholes, etc., and useful for finishing. CONSTITUTION:An aqueous coating material composition obtained by incorporating (A) one or more aqueous resins selected from the group of polyester resin, alkyd resin, acrylic resin, acrylic-modified polyester resin and acrylic-modified alkyd resin with (B) fine particles of a water-insoluble resin of a polymer of an ethylenically unsaturated compound having (i) a rigid inner shell part consisting of a polymer having a high glass transition temperature and (ii) a soft outer shell part having a low glass transition temperature at (97-40)/(3-60) weight ratio and further 0.3-6mu average particle diameter at (99:1)-(15:85) solid weight ratio between the components (A) and (B).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-based paint composition useful as a top coat, and more specifically to a water-based paint composition that contains a water-based resin and water-insoluble resin fine particles as film-forming components and has particularly improved workability and film performance. The present invention relates to an aqueous coating composition.

Attempts to use a combination of an aqueous resin and a water-insoluble resin powder as a resin vehicle for an aqueous coating composition have attracted attention in recent years. For example, Japanese Patent Application No. 51-31636, 51-25
No. 224 etc. contains 10 to 70 wt parts of resin particles and 90 to 90 wt parts of water.
0.5 to 30% of resin particles are added to a slurry consisting of 30Wt parts.
It is also disclosed in Japanese Patent Application No. 49-127151 that water-dilutable resin in an amount of 5 to 50% of the powder resin is added to a slurry of powder resin and water for the purpose of storage stability of the composition. It is described that a water-dispersible resin is added. However, with these slurry-type paints, it is generally difficult to increase the concentration of non-volatile matter, making it impossible to apply thick coatings, and the adhesion of the paint film after painting is insufficient, making it easy for cracks to occur, resulting in poor coating workability, storage stability, etc. It has not been put into practical use due to coating film performance and other issues. Furthermore, Japanese Patent Application No. 54-74606, Japanese Patent Publication No. 54-170262, Japanese Patent Publication No. 55-4149, etc. disclose water-dispersible coating compositions containing powder coatings and water-soluble resins as main components. It is described that about 10 to 20% of the above amount is blended. However, when these are dispersed in water, they become a water-powder resin slurry, and the water-soluble resin is expected to play the role of a dispersion stabilizer. In the end, it is no different from a slurry-type paint, and it does not essentially improve its inherent drawbacks. Under these circumstances, the applicant of the present invention developed a highly remarkable water-based paint composition containing a resin vehicle that is a combination of a water-soluble or water-dispersible resin and water-insoluble resin particles, and filed a patent application in 1983. −． No. 114686). The invention according to the application involves weighing out 5 g of an aqueous varnish with a viscosity range commonly used for paints into a 100 ml beaker, diluting it with deionized water, and pouring it into a Vikar strainer to prepare No. 1 type (2
The water tolerance is expressed as the water dilution ratio at which the 6-point type becomes unreadable, and the water-based varnish has a solid content of 1% W/
The surface tension of the solution obtained by diluting W with deionized water is the selection parameter for the water-based resin (water-soluble resin or water-dispersible resin, the same applies hereinafter), and the tolerance is 4 or more and the surface tension is 516 yne/ If at least one type of aqueous resin that satisfies the requirements below am is used, the aqueous m fat and water-insoluble resin fine powder should be contained in a wide range of blending ratios such as 98:2 to 45:55 in terms of solid content weight ratio. There is no increase in the viscosity of the water-based sake bottle, so it is possible to increase the resin content of the water-based sake bottle, which not only improves workability but also provides a coating composition with excellent stability and coating performance. It was intended to be. However, the water-based paint composition in the above application was developed as an intermediate coat or undercoat, similar to the various proposals made in the past, and is particularly suitable for use as a top coat, which requires a high-gloss, flat surface. The performance was not satisfactory. However, it is a water-based paint composition that not only has excellent paint performance such as workability and storage stability, but also has excellent coating performance such as durability, gloss, and smoothness, and is useful as a top coat. There is an urgent need for this in various painting fields including the automobile industry.

The applicant first prepared a water-based resin selected from alkyd resins and polyester resins, and resin particles obtained by polymerizing an ethylenically unsaturated compound with an average particle diameter of 0.3 to 6 μm and a maximum particle diameter of 10 μm or less in a solid content weight ratio. 99:1 to 40:6
An aqueous coating composition containing an average particle size of 0% by polymerization of an aqueous resin selected from acrylic resins, alkyd resins, and polyester resins and an ethylenically unsaturated compound.
．． an aqueous coating composition containing resin particles of 01 to 0.1μ in a solid weight ratio of 9925-1 to 15:85; and an aqueous resin selected from acrylic-modified alkyd resins and acrylic-modified polyester resins; An aqueous coating composition containing fine resin particles with an average particle diameter of 0.01 to 6μ obtained by polymerization of an ethylenically unsaturated compound in a solid content weight ratio of 99:1 to 15:85 has excellent workability and storage stability. Not only is it highly durable, but it also provides a high gloss and smooth painted surface.
It was discovered that it is useful as a top coat, and patent applications No. 57-174890, No. 57-174891, and No. 5 were filed, respectively.
A patent application was filed as No. 7-174892.

The present invention is a further development of the above invention.

That is, the above invention is a combination of a specific water-based resin and a specific water-insoluble resin, in which the average particle diameter of the resin particles is within a specific range, and when used in combination at a certain mixing ratio,
Due to the special rheological properties of the system, it is possible to increase the resin concentration without increasing viscosity, and it is excellent in workability, as well as providing a high gloss and smooth coating surface, meeting various requirements as a top coat. It was believed that a water-based coating composition with sufficient grooves could be obtained, but the present inventors conducted research on the particle structure and surface structure of the resin particles, and investigated the particle structure and surface structure of the resin particles. It has a two-layer structure consisting of a shell and an outer shell, and by making the outer shell relatively harder than the inner shell, it changes the flow characteristics of the paint and improves workability and coating performance on bottles, etc. The inventors of the present invention have realized that the present invention has been particularly improved and that a wider range of combinations of water-based resins and water-insoluble resins can be used.

Therefore, the object of the present invention is to provide a water-based paint composition that has excellent workability such as thick coating, storage stability, and durability, and can provide a high-gloss, flat coated surface, which has excellent workability and coating film performance on bottles, etc. An object of the present invention is to provide a coating composition that can provide particularly excellent effects.

The object of the present invention is to provide an aqueous coating composition which contains a binder component consisting of an aqueous resin and water-insoluble resin fine particles as an essential component, and optionally contains a pigment, a crosslinking agent, and other coating additives, in which the aqueous resin is a polyester. At least one selected from the group consisting of resin, alkyd resin, acrylic resin, acrylic modified polyester resin, and acrylic modified alkyd resin, and the water-insoluble resin fine particles are polymers of ethylenically unsaturated compounds with a relative glass transition temperature. These are fine particles with an average particle diameter of 0.3 to 6μ, which have a double structure of a hard inner shell made of a substance with a high glass transition temperature and a soft outer shell made of a substance with a low glass transition temperature. This can be achieved using an aqueous coating composition characterized by a weight ratio of 99:1 to 15:85.

The water-based resin (water-soluble resin or water-dispersible resin, hereinafter the same) used in the present invention is a polyester, alkyd, acrylic, acrylic-modified polyester or acrylic-modified alkyd resin commonly used in the coating field.

That is, the polyester resin used in the present invention is a general polyester resin obtained by a polycondensation reaction of a polybasic acid and a polyhydric alcohol, and in this case, the polybasic acids include oxalic acid, succinic acid, succinic anhydride, adipic acid, Linear dibasic acids such as azelaic acid and sebacic acid; phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic acid, hexahydrophthalic anhydride, tetrabromophthalic anhydride, trimellitic acid, Aromatic fatty acids such as trimellitic anhydride, pyromellitic acid, and pyromellitic anhydride; unsaturated 2-base acids such as maleic acid, maleic anhydride, fumaric acid, and itaconic acid; polyhydric alcohols such as ethylene; Glycol, propylene glycol, 1.3-butylene diol, 1.6
- Glycols such as hexanediol, diethylene glycol, neopentyl glycol, triethylene glycol, hydrogenated bisphenol A1 bisphenol dihydroxypropyl ether, glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, etc. are used as appropriate. However, the above-mentioned polybasic acids and polyhydric alcohols are not limited in any way, and may be any one that can be used as a raw material for ordinary polyester resins. It is also possible to use zero-hydric alcohols.

Alkyd resin is obtained by esterifying and modifying the polyester mentioned above with drying oil, fatty acid, etc., and the oil and fat components include linseed oil, tung oil, oetichica oil, dehydrated castor oil, coconut oil, hydrogenated coconut oil, rice sugar fatty acid, and tol. oil fatty acids, soybean oil,
Any known alkyd resin such as octylic acid may be used, and the alkyd resin may be epoxy-modified, rosin-modified, phenylene-modified, or nol resin-modified. The methods for producing these resins are well known to those skilled in the art and need not be detailed.

Acrylic resins are also preferably used in the present invention. This acrylic resin is obtained by polymerizing the following monomers having one or more polymerizable ethylenically unsaturated bonds in the molecule, either singly or in any combination.

1) Carboxyl group-containing monomers such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, etc. 2) Hydroxyl group-containing monomers 10- For example, 2-hydroxyethyl acrylate, hydroxypropyl acrylate, 2- Hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, allyl alcohol, methalyl alcohol, etc. 3) Nitrogen-containing alkyl acrylate or methacrylate, such as dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, etc. 4) Polymerizable amides, such as acrylic acid amide, methacrylic acid amide, etc. 5) Polymerizable nitrile, such as acrylonitrile, methacrylate amide, etc. 6) Alkyl acrylate or methacrylate, such as methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethyl xyl acrylate etc. 7) Polymerizable aromatic compounds such as styrene, α-methylstyrene, vinyltoluene, t-butylstyrene etc. 8) α-olefins such as ethylene, propylene etc. 9) Vinyl compounds such as vinyl acetate, vinyl propionate etc. 10) Dienes Compounds such as butadiene, isoprene, etc. These α,β-edylenically unsaturated monomers can be
Polymerization can be carried out by any known polymerization method in the presence of a radical initiator such as an organic peroxide, an inorganic peroxide, or an azo compound.

Furthermore, another group 0 aqueous resin preferably used in the present invention is an acrylic-modified polyester or alkyd resin, that is, a polyester resin or an alkyd resin in which acrylic polymer segments are incorporated. Resin can be given. Such acrylic modified resins can be obtained, for example, by the following methods.

(1) An acrylic resin is synthesized in the presence of a polyester or alkyd resin having an unsaturated group.

When producing polyester through the polycondensation reaction of a polybasic acid and a polyhydric alcohol, if an unsaturated acid such as maleic acid, maleic anhydride, fumaric acid, citraconic acid, itaconic acid, dimer acid, etc. is used as the polybasic acid, A polyester having unsaturated groups is obtained, and when such unsaturated polyester or saturated polyester is subjected to esterification modification by acting with a drying oil, a fatty acid, etc., an alkyd resin having unsaturated groups is obtained. In the presence of polyester or alkyd resins containing such unsaturated groups, customary free radical catalysts such as azobisisobutyronitrile, benzoyl peroxide, di-t-
Butyl peroxide, cumene hydroperoxide, etc.
Alternatively, chain transfer agents such as ethyl mercaptan, butyl mercaptan, dodecyl mercaptan 1. By polymerizing an acrylic monomer using carbon tetrabromide, carbon tetra-13-carbon, etc., the acrylic modified polyester or alkyd resin used in the present invention can be obtained. As the acrylic monomer in this case, the aforementioned various compounds having one or more polymerizable ethylenically unsaturated bonds in the molecule, which are usually used in the production of acrylic resins, are used.

(2> Polymerization of an acrylic monomer group containing an ethylenically unsaturated monomer containing an oxirane group as one component is carried out in the presence of a polyester or alkyd resin containing a carboxylic acid group.

Polyester resins or alkyd resins usually contain carboxylic acid groups due to the polybasic nature of the raw materials from which they are manufactured. Therefore, the aforementioned acrylic monomer group containing as one component an ethylenically unsaturated monomer having an oxirane group such as glycidyl acrylate or glycidyl methacrylate is polymerized in the presence of such a carboxylic acid group-containing polyester or alkyd resin. By doing so, an acrylic modified polyester or alkyd resin is obtained.

14-(3) Polymerization of an acrylic monomer group containing a monomer containing a carboxylic acid group as one component is carried out in the presence of a polyester or alkyd resin containing an oxirane group.

When producing a polyester or alkyd resin, for example, a polyester or alkyd resin having an oxirane group is obtained by using a polyhydric alcohol component having two or more oxirane groups and a polybasic acid component. The above-mentioned acrylic monomer group containing acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, etc. as one component is reacted with an α,β-ethylenically non-saturated saturated monomer having a group. By doing so, the acrylic modified polyester or alkyd resin used in the present invention can be obtained.

(4) A method of reacting a polyester or alkyd resin (or acrylic resin) containing a carboxylic acid group with an acrylic resin (or polyester or alkyd resin) containing an oxirane group.

If a polyester or alkyd resin and an acrylic resin are supported with a carboxylic acid group on one side and an oxirane group on the other and both resins are allowed to react, the reaction between the carboxylic acid group and the oxirane group will produce an acrylic modified polyester or alkyd resin. can get.

(5) Polymerizing an acrylic monomer in the presence of a mercapto group-containing polyester or alkyd resin.

A polyester or alkyd resin is obtained using a polybasic acid or a polyhydric alcohol having a mercapto group, and this is used in a chain transfer reaction to polymerize the above-mentioned acrylic monomer.

The above is a typical manufacturing method example of the acrylic modified polyester or alkyd resin of the present invention, but does not limit the present invention. It should be understood that any available method can be used and any of them are suitable for the purposes of the present invention. The aqueousization of such a resin is carried out in accordance with a conventional method, for example, by replacing an acidic group such as a carboxyl group with a basic substance (such as monomethylamine, dimethylamine, trimethylamine, monoethylamine, etc.).
Triethylamine, monoisopropylamine, diisopropylamine, diethylenetriamine, triethylenetetramine, monoethanolamine, jetanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, dimethylethanolamine, morpholine, methylmorpholine, piperazine, By neutralizing with ammonia, sodium hydroxide, potassium hydroxide, lithium hydroxide, etc., water solubility or water dispersibility is imparted, and it is conveniently used for the purpose of the present invention. The aqueous resin may be one or more of the above-mentioned resins, and may be either a thermoplastic type or a thermosetting type.

That is, these may or may not carry functional groups that can react with other aqueous resins and/or powder resin functional groups upon heating. Examples of such functional groups to be supported include carboxylic acid groups,
These include sulfonic acid groups, phosphoric acid groups, water 17-acid groups, oxirane groups, active methylol groups, amino groups, reactive carbon-carbon unsaturated bonds, isocyanate groups, blocked isocyanate groups, and halogens. If desired, it can be easily incorporated into the resin by common methods such as selecting monomers during resin production and controlling polymerization reactions.

In the present invention, a water-insoluble resin fine powder is used together with the above-mentioned aqueous resin. Or it is a copolymer. The ethylenically unsaturated compound in this case can be any compound having one or more polymerizable ethylenically unsaturated bonds in the molecule, either singly or in combination. used in the form of

However, one of the most important features of the present invention is that the fine particles of the acrylic or vinyl polymer or copolymer are water-insoluble and made as fine particles, and the glass transition temperature (T (1) It is necessary to have a relatively double structure that is distinguished by the height of 18 - a hard inner shell part and a soft outer shell part.

Water-insoluble resin fine particles made of a polymer of an ethylenically unsaturated compound are thus divided into two parts: a hard inner shell part made of a polymer with a relatively high glass transition temperature, and a soft outer shell part made of a polymer with a relatively low glass transition temperature. By having a heavy structure, it exhibits specific flow characteristics due to the interaction between the water-based resin and the water-insoluble resin particles, is particularly excellent in terms of workability, and further improves the film performance of bottles, etc., and has a high gloss and smooth surface. In addition, the type of aqueous resin to be combined with the polymer fine particles and the permissible particle size lJ of the resin fine particles have been expanded (however, as will be explained later, for fine particle manufacturing reasons, the fine particle The average particle size of the particles is limited to a certain range), and the present invention was made based on this knowledge.

When producing polymers of ethylenically unsaturated compounds, for example, the glass transition temperature (T()) of the resulting homopolymer differs depending on the type of monomer to be polymerized, and in the case of a copolymer, the glass transition temperature The glass transition temperature of the copolymer is intermediate between the homopolymers of the monomers used, the glass transition temperature of the copolymer can be arbitrarily designed by changing the proportion of the monomers, and the blending of plasticizers, solvents, etc. All methods for lowering the glass transition temperature of the polymer, such as scales, are subject to known techniques.The method for producing a polymer of an ethylenically unsaturated compound and the technique for producing fine particles of the polymer are also known.Therefore, the present invention It is relatively easy to make the water-insoluble resin fine particles have a double structure of a hard inner shell made of a polymer with a relatively high glass transition temperature and a soft outer shell made of a polymer with a relatively low glass transition temperature.
This can be easily accomplished by a person skilled in the art using conventional methods. However, from the viewpoint of adjusting such particles to fine particles, it is particularly preferably recommended that both the inner and outer shell polymers be prepared by emulsion polymerization.

In that case, first, the monomers to constitute the inner shell are polymerized by a conventional emulsion polymerization method in the presence of a polymerization initiator in an aqueous medium containing a surfactant or an emulsifier. As the emulsifier, any one commonly used in emulsion polymerization can be used, or instead of or in combination with it, for example, Japanese Patent Application No. 11086/1986
5; 55-56048: 55-1 162
93:53-123899:55-47652
:56-71864:57-13053 etc. can be used, and the polymerization initiator can also be a common one, such as benzoyl peroxide, t-butyl peroxide,
Organic peroxides such as cumene hydroperoxide; organic azo compounds such as azobiscyanovaleric acid, azobisisobutyronitrile, azobis-(2,4-dimethyl)valeronitrile, azobis(2-amidinopropane) hydrochloride; potassium sulfate, ammonium persulfate,
Inorganic water-soluble radical initiators such as sodium persulfate and hydrogen peroxide; redox initiators can be used.

Incidentally, the resin particle size is preferably controlled to be 0.3 to 6 μm or less. Next, a monomer(s) that should give a polymer with a glass transition temperature lower than that of the inner shell is added, optionally together with an additional initiator, and the fine polymer particles constituting the inner shell are used as seeds. It is polymerized by emulsion polymerization to obtain double-structured 21-fine particles with a particle size of 0.3 to 6 μm. However, in the present invention, there is no set method for producing water-insoluble resin particles, and various other known methods may be employed, and it is also possible to use the NAD method using a non-aqueous solvent.

As already mentioned, ethylenically unsaturated compounds have a double structure of a hard inner shell made of a polymer with a relatively high glass transition temperature and a soft outer shell made of a polymer with a relatively low glass transition temperature. When fine polymer particles are used, the types of aqueous resins that should not be combined with the polymer particles and the allowable particle size of the fine resin particles can be expanded over a wide range. However, taking into account that the 61 fat particles are produced by the two-stage polymerization method as described above, it is most practical for the average particle diameter of the particles to be in the range of 0.3 to 6 μm. A particularly preferred range is 0°4 to 5μ. In the present invention, the 1141 ratio of the ethylenically unsaturated compound polymers that constitute the inner shell and outer shell of the double-structured fine particles can also be varied over a wide range, and usually the outer shell has a ratio of 3 to 60/ The inner shell portion is arbitrarily selected within the range of 97 to 40% by weight. 22- The number average molecular weight of the polymer constituting the outer shell is usually 2°50.
It is preferable that it is 0-50.000. However, these are not absolute and can be changed as appropriate depending on desired effects and other factors.

The resin microparticles having the above-mentioned specific structure and specified particle size can be used for one second or in combination of two or more types, and they may react with the water-based resin or between resin microparticles when heated. It is also free to carry a functional group that can be used or not to carry such a functional group.

After all, the resin composition used in the present invention may be thermoplastic or thermosetting as a whole. In the coating composition of the present invention, the aqueous resin and the water-insoluble resin fine particles have a solid content weight ratio of 99 to 15% for the former and 1 to 85% for the latter, preferably 98 to 40% for the former and 2 for the latter. ~6
It is necessary that the combination be within a range of 0%. This is because if the water-based resin content is too low, the dispersion stability of the resin particles will deteriorate and the smoothness of the coating film will be impaired, and if the resin particles are less than 1% by weight, the purpose of the present invention as a top coat will be impaired. This is because it is not achieved.

Water is used as the medium, but a hydrophilic polar organic solvent can also be co-present if desired.

Examples of such organic solvents include ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, methanol, ethanol, isopropyl alcohol, n-butanol, sebutanol, t-butanol, and dimethylformamide. However, in the composition of the present invention, the ratio of the water medium to the resin component is quite fluid.

This means that the solid content is usually around 10-80% for spray painting, 5-90% for brush painting, and 1-60% for dipping.
However, the composition of the present invention is extremely stable due to its unique flow characteristics and the unique surface characteristics of the resin particles, and can be adjusted to any moisture content and stored. This is also because it can be diluted with water to a predetermined concentration before use. In the present invention, the above-mentioned water-based resin has a unique surface property and has a double structure structure.
4- To obtain a high-gloss, smooth topcoat surface that is excellent in terms of coating performance, especially for bottles, etc., by using the composition containing IC water-insoluble resin fine particles and water as an essential component as a clear paint. I can do it.

In addition, by adding pigments, cross-linking agents, and other additives to this resin composition and uniformly dispersing and mixing it according to ordinary paint manufacturing techniques, it has excellent workability, and has a high gloss, smooth coating, and is particularly suitable for coating on bottles, etc. A water-based top coating composition with excellent film performance can be obtained.

As the pigment, any pigment commonly used in top coatings can be used and can be well dispersed.

When blending pigments, make a pigment paste in advance using a portion of the water-based resin, add the remaining amount of the water-based resin, resin fine particles, and other additives, and use a known dispersion machine such as a gate mixer or high-speed disper. It is particularly preferable to mix and disperse them uniformly. However, of course, it is also possible to form a paint by mixing and dispersing each component using a dispersion machine from the beginning.

If desired, a crosslinking agent may be added to the coating composition of the present invention, such as melamine formaldehyde resin, methoxy-modified, butoxy-modified melamine formaldehyde resin, urea resin, thiourea resin, guanamine resin, acetate resin, etc. Any known crosslinking agents such as aminoplasts such as guanamine resins, isocyanate compounds such as isocyanates, polyisocyanates, and blocked isocyanates, and phenol resins are preferably used. Furthermore, if desired, other conventional additives such as anti-sag agents,
It is also possible to appropriately add an anti-settling agent, an anti-color separation agent, an anti-cissing agent, a surface tension regulator, an antioxidant, a light stabilizer, an ultraviolet absorber, and the like. The amounts of these pigments, crosslinking agents, and other additives, blending methods, etc., are all appropriately selected and used in accordance with the production of ordinary topcoat paints.

The coating composition of the present invention can be applied as it is or further diluted with water, applied by ordinary coating methods such as spraying, dipping, brushing, etc., and baked by drying or heating, and has high gloss, smoothness, and durability. A top coated surface with excellent coating performance on bottles, etc. can be obtained. Furthermore, the paint has good storage stability and has an exceptional workability score of 26 points, making it extremely useful as an aqueous paint composition for top coating.

The present invention will be explained below with reference to production examples, examples, and comparative examples.

Note that unless otherwise specified, "parts" means "parts by weight."

Production Example 1 Production of Resin Fine Particles-1 1100 parts of deionized water was weighed out into a 2-liter glass reaction vessel equipped with a stirrer, a temperature controller, and a cooling tube, and the temperature was brought to 80°C. An aqueous solution consisting of 100 parts of deionized water and 6 parts of ammonium persulfate was added to this water while stirring;
5 parts of a monomer mixture consisting of 210 parts of methyl methacrylate, 75 parts of 2-ethylhexyl acrylate, and 15 parts of n-dodecyl mercaptan were added, and stirring was continued for 5 minutes. Thereafter, 295 parts of the monomer mixture was dropped into the reaction solution over 1 hour. After continuing stirring for 15 minutes after the completion of the dropwise addition, an aqueous solution consisting of 10 parts of deionized water and 1 part of ammonium persulfate was added, and stirring was continued for 1 hour to complete the reaction and obtain a seed emulsion with a non-volatile content of 20%. .

250 parts of deionized water and 25 parts of seed emulsion are weighed into a reaction vessel similar to that used for seed emulsion synthesis, and the temperature is brought to 80°C. In this reaction vessel under stirring
An aqueous solution consisting of 10 parts of ionized water and 0.1 part of ammonium persulfate is added, followed by 400 parts of methyl methacrylate.
A pre-emulsion consisting of 29 parts of 2-hydroxyethyl acrylate, 200 parts of deionized water, 0.4 parts of sodium dodecylbenzenesulfonate and 0.9 parts of ammonium persulfate is added dropwise over a period of 2 hours. Calculation of a random polymer consisting of this monomer composition T (l is 93.5°C. At the time when 1 hour and 30 minutes have passed since the start of dropping the pre-emulsion, 60 parts of 2-ethylhexyl acrylate and 2-hydroxyethyl acrylate A monomer mixture consisting of 6 parts is added dropwise at the same time as the pre-emulsion over a period of 30 minutes.The calculated Tg of the random polymer consisting of this 7-mer composition is approximately 180°C.After the addition is complete, stirring is continued for 30 minutes. , an aqueous solution consisting of 20 parts of deionized water and 0.2 parts of ammonium per'fM acid was added, and stirring was continued for 1 hour.
Continue for a certain amount of time to complete the reaction. The obtained emulsion had a non-volatile content of 50.0%, and the average particle size of the contained fine resin particles was 1.6 μm and the maximum particle size was 4.5 μm. Note that the particle size was measured using a transmission electron microscope. Also T
The calculation of o was carried out in accordance with Kyozo Kitaoka, "Introduction to Synthetic Resins for Paints," Kobunshi Publishing, pp. 168-170.

Production Example 2 Production of Resin Fine Particles-2 245 parts of Ilq ion water and 25 parts of seed emulsion were weighed out into a reaction vessel similar to that used in Production Example 1, and the temperature was brought to 80°C. In this reaction vessel, 200 ml of membrane ionized water was added under stirring.
and 0.1 part of ammonium persulfate, followed by 195 parts of methyl methacrylate, 100 parts of 2-ethylhexyl acrylate, 200 parts of deionized water,
2 parts of a pre-emulsion consisting of 0.3 parts of sodium dodecylbenzenesulfonate and 0.6 parts of ammonium persulfate.
Drip over time. Calculation of a random polymer consisting of this monomer composition T! + is 8.5°C.

When the stirring was continued for 10 minutes after the completion of the dropwise addition (after the inner shell was formed), a monomer mixture consisting of 65 parts of methyl methacrylate and 135 parts of 2-ethylhexyl acrylate was added dropwise over a period of 15 minutes. The calculated To of a random polymer consisting of this monomer composition is -48°C. When stirring was continued for 30 minutes after the completion of the dropwise addition, 20 parts of deionized water and filtrate were added.
An aqueous solution consisting of 0.2 parts of R ammonium is added, and stirring is continued for an additional hour to complete the reaction. The resulting emulsion had a nonvolatile content of 48.0%, and the average particle size of the fine resin particles contained therein was 2.6 μm, and the maximum particle size was 4.5 μm.

Production Example 3 Production of Resin Fine Particles-3 520 parts of deionized water was weighed out into a reaction vessel similar to that used in Production Example 1, and the humidity was adjusted to 80°C.

In this water, with stirring, an aqueous solution consisting of 100 parts of deionized water, 15 parts of ammonium persulfate, 384 parts of methyl methacrylate, 96 parts of 2-ethylhexy-30-ruacrylate, and 40 parts of n-dodecyl mercaptan were added.
Add 20 parts of a monomer mixture consisting of 20 parts and continue stirring for 5 minutes. After that, 500% of the monomer mixture was added over 1 hour.
dropwise into the reaction solution. Calculation T (+ is 41.5°C) of a random polymer consisting of this monomer composition. After continuing stirring for 15 minutes after the completion of the dropwise addition, 48 parts of methyl methacrylate, 58 parts of 2-ethylhexyl acrylate, and 2 parts of methacrylic acid were added. A monomer mixture consisting of 12 parts of 2-hydroxyethyl acrylate is added dropwise over 20 minutes.

Calculation To of a random polymer consisting of this monomer composition
is -26.5°C. Subsequently, an aqueous solution consisting of 40 parts of deionized water and 0.2 parts of ammonium persulfate was added, and 1
Stirring is continued for a certain period of time to complete the reaction. The nonvolatile content of the obtained emulsion was 50.0%, and the average particle size of the fine resin particles contained therein was 0.40μ and the maximum particle size was 1.2μ.

Reference Example: Production of Comparative Resin Fine Particles In a reaction vessel similar to that used in the production of Resin Fine Particles-1,
1 (900 parts of 1 ion water, Metrose 60SH-50 (
Shin-Etsu Chemical Co., Ltd., methyl cellulose) 1°5 parts, methyl methacrylate 210 parts, 2-ethylhexyl acrylate 63 parts, 2-hydroxyethyl acrylate 21 parts,
6 parts of methacrylic acid, 6 parts of n-dodecyl mercaptan, and 6 parts of azobisisobutyronitrile were weighed out, and the number of revolutions was 25.
The reaction was completed by keeping the temperature at 65° C. for 7 hours while stirring at Orpm. The resulting suspension is filtered through a 200-mesh wire mesh to obtain pearl particles having a particle size of 20 to 600 μ. This was ground in a ball mill for 24 hours, with an average particle size of 1
The resin particles had a maximum particle size of 8μ and a maximum particle size of 45μ. The molecular weight of this resin was 7,600.

Production Example 4 Production of Aqueous Resin-1 In a 2-liter reaction vessel equipped with a stirrer, temperature controller, and decanter, 273 parts of tall oil fatty acid, 197 parts of trimethylolpropane, 8 parts of neopentyl glycol-lua, and hydrogenated bisphenol were added. 91 parts of A, 204 parts of isophthalic acid, 157 parts of trimellitic anhydride, and 20 parts of xylene were charged, and the temperature was raised while stirring. Reaction temperature from 180℃ to 210℃
The reaction was continued for 5 hours while maintaining the water at
0. Obtain an alkyd resin with an oil length of 30.

Subsequently, 183 parts of ethylene glycol monobutyl ether and 96 parts of dimethylethanolamine were added and diluted with deionized water to obtain an aqueous varnish with a non-volatile content of 50%.

Production Example 5 Production of Aqueous Resin-2 In a reaction vessel similar to that used in the production of Aqueous Resin-1, 69 parts of trimethylolpropane and 2 parts of neopentyl glycol were added.
97 parts, hydrogenated bisphenol A 91 parts, isophthalic acid 2
01 parts, 186 parts of tetrahydrophthalic acid, 155 parts of trimellitic anhydride, and 10 parts of xylene were added and heated while stirring.

The reaction temperature was maintained at 180 DEG C. to 210 DEG C., and the reaction was continued for 5 hours while removing the produced water to obtain a polyester resin having an acid value of 55.08, a valence of 100, and a number average molecular weight of 1,500.

Subsequently, 183 parts of ethylene glycol monobutyl ether and 82 parts of dimethyl ethanolamine were added and diluted with deionized water to obtain an aqueous varnish with a non-volatile content of 50%.

Production Example 6 Production of Aqueous Resin-3 76 parts of ethylene glycol monobutyl ether was charged into a 1-liter reaction vessel equipped with a stirrer, a temperature controller, and a cooling tube, and further 45 parts of styrene, 63 parts of methyl methacrylate, and 2-hydroxyethyl methacrylate were added. 48 copies,
61 parts of a monomer solution consisting of 117 parts of n-butyl acrylate, 27 parts of methacrylic acid, 3 parts of lauryl mercaptan, and 3 parts of azobisisobutyronitrile were added, and the temperature was brought to 120° C. while stirring. 3 parts of 245 parts of the above 7mer solution
After the dropwise addition, stirring was continued for 1 hour.

Additionally, 28 parts of dimethylethanolamine and 2 parts of deionized water
00 parts was added to obtain an acrylic resin varnish having a nonvolatile content of 50% and a resin number average molecular weight of 16,000.

Production Example 7 Production of Aqueous Resin-4 In a 1-liter reaction vessel equipped with a stirrer, a temperature controller, and a cooling tube, 117 parts of dehydrated castor oil, 173 parts of soybean oil, 17 parts of glycerin, 61 parts of pentaerythritol, and phthalic anhydride were added. After weighing out 132 parts and adding 7.5 parts of xylene,
The stirring temperature was maintained at 180°C to 220°C, and the reaction was continued for 3 hours while removing water produced by the polyesterification reaction azeotropically, resulting in an oil length of 57%, an acid value of 10, and an Mn of 1800.
An alkyd resin was obtained. This resin was diluted with xylene to obtain an alkyd resin varnish with a nonvolatile content of 60%.

In a reaction vessel similar to that used for resin synthesis, 200 parts of the above alkyd resin varnish and 104 parts of ethylene glycol monobutyl ether were charged, and the stirring temperature was raised to 130°C.

To this, 60 parts of styrene, 102 parts of methyl methacrylate, 65 parts of 2-hydroxyethyl methacrylate, 31 parts of acrylic acid, 143 parts of n-butyl acrylate, di-1-
6 parts of butyl peroxide, 8 parts of lauryl mercaptan,
A monomer solution consisting of was added dropwise over 3 hours, and stirring was continued for an additional 1 hour to complete the reaction. The obtained acrylic modified alkyd resin had an acid value of 50 and a molecular weight of 7,300. The reaction solution was 100% neutralized with dimethylethanolamine, and then diluted with deionized water to obtain an aqueous varnish with a nonvolatile content of 50%.

Production Example 8 Production of Aqueous Resin-5 In a reaction vessel similar to that used in the synthesis of Aqueous Resin-1, 169 parts of neopendel glycol and 6 parts of trimethylolethane were added.
parts, hydrogenated bisphenol A 46 parts, isophthalic acid 17 parts
4 parts of adipic acid, 65 parts of adipic acid, and 40 parts of maleic anhydride were added, 10 parts of xylene was added, and the temperature was raised to 190~190°C while stirring.
The reaction was continued for 4 hours while maintaining the temperature at 210°C and azeotropically removing water produced by the polyesterification reaction, resulting in an acid value of 48.
A polyester resin having a number average molecular weight of 1200 was obtained.

This resin was diluted with ethylene glycol monobutyl ether to obtain a polyester resin varnish with a nonvolatile content of 80%.

In the production of the acrylic modified alkyd resin in the latter stage of Production Example 7, instead of using 200 parts of the alkyd resin varnish and 104 parts of ethylene glycol monoethyl ether, 150 parts of the above polyester resin and 154 parts of ethylene glycol monobutyl ether were used in the same manner. Acid value 5
An acrylic modified polyester resin having a molecular weight of 0.0 and a molecular weight of 6,500 was obtained.

This was 100% neutralized with dimethylethanolamine,
It was diluted with deionized water to give a 50% non-volatile water-based varnish.

Examples 1 to 6 and Comparative Examples 1 to 2 Preparation of pigment paste In a 1.5 liter sealable stainless steel container, 160 parts of water-based resin-1 obtained in Production Example 4 and 320 parts of Tybake R-820 (6 original industries) were mixed. Weigh out 78 parts of deionized water, rutile type titanium oxide pigment), and add 500 parts of glass beads.
After premixing using a stirrer, the mixture was mixed and dispersed using a paint conditioner for 2:37 hours to obtain pigment paste-1. Also, instead of water-based resin-1, water-based resins-2, 3, and 4 obtained in Production Examples 5 to 8
, 5 to obtain pigment pastes 2, 3, 4, and 5 in the same manner.

Each material was weighed out in a stainless steel container according to the recipe listed in Table 1, and mixed at room temperature with a stirrer to obtain a coating composition.

Each of the coating compositions of Examples 1-6 and Comparative Examples 1-2 was diluted with deionized water and adjusted to a viscosity of 30 seconds in a #4 Ford cup. It was spray coated on a steel plate according to a conventional method, allowed to set for 15 minutes, and then baked at 150° C. for 15 minutes to obtain a dry coating. The pin and sag limit film thicknesses and gloss values for each composition are listed in the same table.

However, film thickness limit bottle Film thickness limit sagging Gloss value 050 parts or more at 60' cross value 050 parts or more 090 or more 0 40 parts or more 0 4
0 copies or more Q 85 or more Δ 30~40μ
Δ 30~40μ △ 80~85×30μ
Less than × 30μ or less × 80 or less 38−

Claims (4)

[Claims] (1) In a water-based paint composition containing as an essential component a binder component consisting of a water-based resin and water-insoluble resin fine particles, the water-based resin may be a polyester resin, an alkyd resin,
At least one selected from the group consisting of acrylic resin, acrylic-modified polyester resin, and acrylic-modified alkyd resin, and the water-insoluble resin fine particles are polymers of ethylenically unsaturated compounds with a relatively high glass transition temperature. An average particle diameter of 0.3 to 1000, which has a dual structure of a hard inner shell and a soft outer shell with a low glass transition temperature.
An aqueous coating composition comprising fine particles of 6 μm in size and having a solid content weight ratio of the aqueous resin to the water-insoluble resin of 99=1 to 15:85. (2) The composition according to claim 1, wherein the weight ratio of the polymers constituting the inner shell and outer shell of the water-insoluble resin fine particles is 97-40/3-60. (3) The average particle diameter of the water-insoluble resin particles is 0.4 to 5μ
The composition according to any one of claims 1 to 2. (4) The number average molecular weight of the polymer constituting the outer shell is 2.5
Claims 1 to 3 are from 00 to 50,000.
The composition according to any of paragraphs.