JP6039963B2 - Water-based paint composition - Google Patents

Description

  The present invention relates to a water-based paint composition, a paint and a coating agent containing the water-based paint composition, a method for forming a coating film using the paint, and a method for producing the water-based paint composition.

  Conventionally, coating is performed for the purpose of protecting the surface of various materials such as plastic, metal, and wood and decorating the appearance. Many of the paints used for coating are made by dissolving the resin used to form the coating film with a volatile organic solvent. However, the use of water-based paints is desirable from the viewpoint of safety, environmental friendliness, and hygiene. ing. However, since water-soluble resins have poor durability, water-based paints in which water-insoluble resins are dispersed in water-based solvents have been developed.

For example, Patent Document 1 discloses that a specific peak top particle has at least two peaks in a particle size distribution curve for the purpose of reducing viscosity, improving stability over time, and film-forming properties during drying. An aqueous dispersion comprising synthetic resin particles having a diameter ratio, a specific height ratio, a specific peak variation coefficient, a skewness and a saliency and a specific viscosity is disclosed.
Patent Document 2 discloses an anionic emulsifier having a sulfate ester group or a sulfonic acid group in the molecule and a hydrophilic group in the molecule for the purpose of improving coating workability, adhesion to a plastic substrate, and solvent resistance. Disclosed is an aqueous resin composition for coating plastic materials, characterized in that it contains an emulsion resin obtained by polymerizing a mixture of polymerizable unsaturated monomers in the presence of a polyester resin as a film-forming component. Has been.

JP 2003-171570 A JP-A-7-207219

A water-based paint using a dispersion of a water-insoluble resin forms a coating film by adhering to the resin particles dispersed in the paint after drying as the coating is dried. A resin that is easily dissolved in an aqueous solvent, such as 2, or a plasticizer is used. However, according to these methods, although the film forming property is improved, there is a problem that the obtained coating film is inferior in heat resistance and solvent resistance.
From the viewpoint of achieving both the film-forming property, heat resistance, and solvent resistance, there is still room for improvement in the paints using the resins described in Patent Documents 1 and 2.
In addition, since the water-based paint volatilizes water to obtain a coating film, there is also a problem that the drying property is inferior.
The present invention relates to a water-based coating composition having excellent film-forming properties and film-drying properties, and excellent heat resistance and solvent resistance of the resulting coating film, and a paint and a coating agent using the water-based coating composition. Another object of the present invention is to provide a method for producing this water-based paint composition and a method for forming a coating film using this paint.

The present inventors considered that the factors affecting the film-forming property, film-drying property, and heat resistance and solvent resistance of the resulting coating film are in the type of resin and the state of the resin particles at the time of coating film formation. Went. As a result, by using a water-based coating composition containing two kinds of polyester resin particles having specific different volume-median particle sizes in a specific ratio, film forming property, film drying property, and heat resistance of the obtained coating film are obtained. And improved solvent resistance.
That is, the present invention provides the following [1] to [6].
[1] 55/45 polyester resin particles (A) having a volume median particle size of 0.07 to 0.40 μm and polyester resin particles (B) having a volume median particle size of 0.01 to 0.05 μm A water-based coating composition blended at a mass ratio of ˜97 / 3.
[2] A water-based coating composition containing polyester resin particles, wherein the polyester resin particles have a volume-median particle size of 0.06 to 0.40 μm, and were centrifuged under the following centrifugal conditions. The mass ratio (x) / (y) of the resin component (x) that precipitates to the resin component (y) that does not precipitate is 55/45 to 97/3, and the volume median of the resin component (y) An aqueous coating composition having a particle size of 0.01 to 0.05 μm.
Centrifugation conditions: After making a 20% by mass aqueous dispersion of polyester resin particles, centrifugation is performed at 25 ° C. and a relative centrifugal acceleration of 3.5 × 10 ⁴ G for 5 hours.
[3] A coating agent containing the water-based paint composition according to any one of [1] and [2].
[4] A paint containing the water-based paint composition according to any one of [1] and [2].
[5] Coating is formed using the paint according to [4] above, and then dried at a temperature equal to or lower than the glass transition temperature of the resin particles having the lowest glass transition temperature among the resin particles contained in the paint. Method.
[6] The method for producing an aqueous coating composition according to [1], comprising the following steps (1) to (3).
Step (1): A polyester resin (a1) having a non-aromatic carbon-carbon unsaturated bond is prepared, the polyester resin (a1) is mixed with an aqueous medium, and an aqueous dispersion of the polyester resin (a1) is prepared. Step (2): Addition-polymerizable monomer (a2) is added to the aqueous dispersion of polyester resin (a1) obtained in step (1) and polymerized to obtain an aqueous dispersion of graft polymer. Step of obtaining an aqueous dispersion of polyester resin particles (A) having a volume median particle size of 0.07 to 0.40 μm Step (3): The aqueous dispersion obtained in step (2) and polyester resin particles ( Step of mixing the aqueous dispersion of B) to obtain an aqueous coating composition

  According to the present invention, a water-based coating composition having excellent film-forming properties and film-drying properties and excellent heat resistance and solvent resistance of the obtained coating film, and a paint and a coating agent using the water-based coating composition, The coating film formation method using this coating material and the manufacturing method of this water-system coating composition can be provided.

[Aqueous Coating Composition of First Embodiment]
The water-based coating composition of the first aspect of the present invention comprises a polyester resin particle (A) (hereinafter also simply referred to as “resin particle (A)”) having a volume median particle size of 0.07 to 0.40 μm and a volume. Polyester resin particles (B) having a median particle size of 0.01 to 0.05 μm (hereinafter also simply referred to as “resin particles (B)”) are blended at a mass ratio of 55/45 to 97/3. Is.

The reason why the water-based coating composition of the present invention is excellent in film-forming properties and film-drying properties, and in the heat resistance and solvent resistance of the obtained coating film is not clear, but is considered as follows.
The water-based coating composition used in the present invention uses two types of polyester resin particles having a relatively small particle size. Among these, the resin particles (B) on the small particle size side having a volume median particle size of 0.01 to 0.05 μm are resin particles (B) due to surface tension when water is evaporated when a coating film is formed. When they are close to each other, especially when they are mixed with resin particles (A) having a large particle diameter, the force tends to concentrate on the resin particles (B) on the small particle diameter side. The polyester resin of the present invention is plasticized with water because it has a hydroxyl group and a carboxy group at the terminal due to the monomer as a raw material, but particularly large particles are plasticized only to the extreme surface with water, Since the resin particles (B) are plasticized relatively to the inside, the resin particles (B) are deformed by the surface tension, and the film is formed so as to fill the space between the resin particles (A) having a large particle size without any gap. Therefore, it is considered that the obtained coating film is excellent in heat resistance and solvent resistance.
Furthermore, since the water-based coating composition of the present invention has a small ratio of the resin particle (B) on the small particle size side, it is considered that the viscosity and the film forming and drying are performed rapidly without increasing the viscosity of the coating composition. .
In the present invention, the “water-based coating composition” refers to a resin particle containing at least resin particles (A) and resin particles (B) as resin particles in an aqueous medium described later, and resin particles (A) as resin particles. And those containing resin particles (B) are preferred.

<Polyester resin particles (A)>
The volume median particle size of the polyester resin particles (A) used in the present invention is from the viewpoint of improving the film forming property and the film drying property, and improving the heat resistance and solvent resistance of the resulting coating film. It is 07-0.40 μm.
Among these, from the viewpoint of improving the film drying property, it is preferably 0.07 μm or more, more preferably 0.1 μm or more, still more preferably 0.12 μm or more, and still more preferably 0.13 μm or more. More preferably 0.14 μm or more. From the viewpoint of improving the film forming property, it is preferably 0.40 μm or less, more preferably 0.30 μm or less, still more preferably 0.2 μm or less, still more preferably 0.18 μm or less, More preferably, it is 0.16 μm or less.
From these viewpoints, the volume median particle size of the resin particles (A) is preferably 0.1 to 0.30 μm, more preferably 0.12 to 0.2 μm, and still more preferably 0.13 to 0.33. The thickness is 0.18 μm, and more preferably 0.14 to 0.16 μm.
Here, the “volume median particle size” means a particle size at which the cumulative volume frequency measured by the volume fraction becomes 50% cumulative from the smaller particle size. The measuring method is as described in the examples.

  Although there is no restriction | limiting in the method of adjusting the volume median particle diameter of resin particle (A) to the said range, For example, when emulsifying a polyester-type resin in an aqueous medium, the amount and kind of activator Adjusting by changing one or more kinds of temperature, the amount and type of neutralizing agent, changing the amount and type of solvent, changing the acid value of the polyester-based resin, one or more types The method of doing is mentioned. Among these, since the particle size can be adjusted without greatly affecting the resulting coating film, the stirring force, the amount and type of the activator, the temperature, the amount and type of the neutralizing agent, the amount and type of the solvent are 1 A method of adjusting by changing one or more is preferable, and a method of adjusting by changing the stirring force is more preferable.

Moreover, the storage elastic modulus (G ′) at 200 ° C. of the resin particles (A) is preferably 10 to 1000000 Pa, more preferably 1000 to 100000 Pa, from the viewpoint of film forming property and solvent resistance.
The storage elastic modulus (G ′) at 200 ° C. can be measured by the method described in the examples.

The glass transition temperature of the resin particles (A) is preferably 50 ° C. or higher, more preferably 60 ° C. or higher, and preferably 100 ° C. or lower, from the viewpoints of film forming properties and heat resistance of the resulting coating film. More preferably, it is 80 ° C. or lower. From this viewpoint, the glass transition temperature is preferably 50 to 100 ° C, more preferably 50 to 80 ° C, and still more preferably 60 to 80 ° C.
In addition, the resin particle (A) may be composed of a resin component and a component other than the resin such as an activator in addition to the case where the resin particle is composed of only the resin. In the present invention, the storage elastic modulus (G ′) and glass transition temperature at 200 ° C. of the resin particles (A) are, when the resin particles (A) contain components other than the resin, A) It means a measured value when the whole is measured by the measuring method described in the examples.

<Graft polymer>
The resin constituting the resin particles (A) is a polyester resin, and may be a resin composed only of polyester or a modified polyester resin. From the viewpoint of solvent properties, the main chain segment (A1) made of polyester resin (hereinafter also simply referred to as “segment (A1)”) and the side chain segment (A2) made of addition polymerization resin (hereinafter simply referred to as “segment (A2)”. The polymer is also preferably a graft polymer consisting of (also referred to as “)”. In addition, also when it is resin which consists only of polyester, the composition similar to a segment (A1) can be used.

When the resin constituting the resin particle (A) is a graft polymer having the segment (A1) as the main chain and the segment (A2) as the side chain, the segment (A1) and the segment (A2) constituting the graft polymer The mass ratio [Segment (A1) / Segment (A2)] is preferably 55/45 or more, more preferably 65/35 or more, from the viewpoints of film-forming properties and solvent resistance of the resulting coating film. More preferably, it is 75/25 or more, and preferably 95/5 or less. The mass ratio is preferably 55/45 to 95/5, more preferably 65/35 to 95/5, and more preferably 75/25 to 95/5.
It is considered that the presence of more segments (A1) than segments (A2) increases the affinity with water and is excellent in film-forming properties.

(Polyester resin segment (A1))
The polyester resin segment (A1) constituting the graft polymer is a resin segment obtained by condensation polymerization of an alcohol component and a carboxylic acid component.

[Alcohol component]
The alcohol component, which is a raw material monomer of the segment (A1), preferably contains an alkylene oxide adduct of bisphenol A from the viewpoint of solvent resistance.
In the present invention, the alkylene oxide adduct means the whole structure in which an oxyalkylene group is added to 2,2-bis (4-hydroxyphenyl) propane.
Specifically, the alkylene oxide adduct of bisphenol A is preferably a compound represented by the following general formula (I).

In the general formula (I), R ¹ O and R ² O are both oxyalkylene groups, preferably each independently an oxyalkylene group having 1 to 4 carbon atoms, and more preferably an oxyethylene group or an oxyethylene group. Propylene group.
x and y correspond to the number of added moles of alkylene oxide. Furthermore, from the viewpoint of reactivity with the carboxylic acid component, the average value of the sum of x and y is preferably 2 to 7, more preferably 2 to 5, and still more preferably 2 to 3.
Further, x R ¹ O and y R ² O may be the same or different from each other, but are preferably the same from the viewpoint of heat resistance. The alkylene oxide adduct of bisphenol A may be used alone or in combination of two or more. This alkylene oxide adduct of bisphenol A preferably contains one or two of a propylene oxide adduct of bisphenol A and an ethylene oxide adduct of bisphenol A, more preferably one or two of these two adducts. It comprises a seed, more preferably a propylene oxide adduct of bisphenol A, and even more preferably comprises these two adducts.
The content of the alkylene oxide adduct of bisphenol A in the alcohol component that is the raw material monomer of the segment (A1) is preferably 50 mol% or more, more preferably 60 mol%, from the viewpoint of solvent resistance and heat resistance. It is above, More preferably, it is 70 mol% or more. Further, from the viewpoint of film forming property, the content of the alkylene oxide adduct of bisphenol A is preferably 90 mol% or less, more preferably 85 mol% or less, and still more preferably 80 mol% or less.

In addition to the alkylene oxide adduct of bisphenol A, the following alcohol components can be contained in the alcohol component which is a raw material monomer of the segment (A1).
Specifically, examples of the alcohol component of the raw material monomer derived from the structural unit of the segment (A1) (hereinafter also simply referred to as “raw material monomer of the segment (A1)”) include ethylene glycol, propylene glycol (1,2 -Propanediol), glycerin, pentaerythritol, trimethylolpropane, hydrogenated bisphenol A, sorbitol, or their alkylene (2 to 4 carbon) oxide adduct (average number of added moles 1 to 16). You may use the said alcohol component individually or in combination of 2 or more types. Among these, 1, 2-propanediol and hydrogenated bisphenol A are preferable, or 1,2-propanediol or hydrogenated bisphenol A is more preferable.

[Carboxylic acid component]
The segment (A1) is a polyester resin, and a carboxylic acid component is used in addition to the alcohol component as a raw material monomer.
Examples of the carboxylic acid component that is a raw material monomer of the segment (A1) include aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid; adipic acid, succinic acid, succinic acid having an alkyl group and / or alkenyl group, Aliphatic dicarboxylic acids such as allyl alcohol; alicyclic dicarboxylic acids such as cyclohexane dicarboxylic acids and decalin dicarboxylic acids; trivalent or higher polyvalent carboxylic acids such as trimellitic acid and pyromellitic acid, and anhydrides of these acids; These alkyl (C1-C3) ester etc. are mentioned.

  Aromatic dicarboxylic acids and alicyclic dicarboxylic acids are preferred, and cyclohexanedicarboxylic acid and isophthalic acid are more preferred from the viewpoints of improving film-forming properties and film drying properties and improving heat resistance and solvent resistance of the resulting coating film. Among these, aromatic dicarboxylic acids are preferable, and isophthalic acid is more preferable. The said carboxylic acid component may be individual or 2 or more types may be contained.

  Further, when the resin constituting the resin particle (A) is a graft polymer having the segment (A1) as a main chain and the segment (A2) as a side chain, it has a non-aromatic carbon-carbon unsaturated bond. It is preferred to include a carboxylic acid, such as an unsaturated aliphatic carboxylic acid and / or an unsaturated alicyclic carboxylic acid. The portion of the carbon-carbon unsaturated bond can be a binding portion with the segment (A2) in the graft polymer, in which case the unsaturated bond becomes a saturated bond.

  Examples of carboxylic acids having non-aromatic carbon-carbon unsaturated bonds (unsaturated aliphatic carboxylic acids and unsaturated alicyclic carboxylic acids) include unsaturated fats such as fumaric acid, maleic acid, acrylic acid, and methacrylic acid. Group carboxylic acids; unsaturated alicyclic carboxylic acids such as tetrahydrophthalic acid. From the viewpoint of reactivity, fumaric acid, maleic acid and tetrahydrophthalic acid are preferable, and fumaric acid is more preferable.

In the carboxylic acid component, the content of the carboxylic acid having a non-aromatic carbon-carbon unsaturated bond is sufficient to graft the segment (A2) while maintaining the effect of improving the film-forming property by the segment (A1). From the viewpoint of expressing the effect of improving the solvent resistance due to the segment (A2), it is preferably 5 to 30 mol%, more preferably 7 to 25 mol%, still more preferably 8 to 20 mol%.
In the carboxylic acid component, the content of the aromatic dicarboxylic acid is preferably 50 mol% or more, more preferably 70 mol% or more, and still more preferably 80 mol% or more, from the viewpoint of improving heat resistance. Is 95 mol% or less, more preferably 90 mol% or less, still more preferably 88 mol% or less.

  In the segment (A1), the molar ratio of the hydroxyl group of the alcohol component to the carboxy group of the carboxylic acid component (hydroxyl group / carboxy group) from the viewpoint of appropriately adjusting the particle size of the resin particles and improving the heat resistance and the film-forming property. Is preferably 100/90 to 100/120, more preferably 100/95 to 100/110, still more preferably 100/100 to 100/105.

(Side chain segment (A2) made of addition polymerization resin)
When the resin constituting the resin particle (A) is a graft polymer, the segment (A2) constituting the graft polymer is derived from an addition polymerizable monomer (a2) (hereinafter also referred to as “monomer (a2)”). It is a segment made of an addition polymerization resin made of units. The segment (A2) is a side chain in the graft polymer when the resin constituting the resin particle (A) is a graft polymer.
Examples of the addition polymerizable monomer (a2) used in the present invention include styrene, methylstyrene, α-methylstyrene, β-methylstyrene, t-butylstyrene, chlorostyrene, chloromethylstyrene, methoxystyrene, styrenesulfonic acid or the like. Styrenes such as salts; (meth) acrylic acid esters such as alkyl (meth) acrylate (1 to 18 carbon atoms), benzyl (meth) acrylate, dimethylaminoethyl (meth) acrylate; ethylene, propylene, butadiene, etc. Olefins such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as vinyl methyl ether; vinylidene halides such as vinylidene chloride; N-vinyl compounds such as N-vinyl pyrrolidone; Or one or more of It is.
Among these, from the viewpoint of improving solvent resistance, one or two of styrenes and (meth) acrylic acid esters are preferable, an addition polymerizable monomer having an aromatic group is more preferable, styrene, methylstyrene, One or more of phenoxyethylene glycol (meth) acrylate, benzyl methacrylate, and benzyl acrylate are more preferable. Among these, one or two of styrene and phenoxyethylene glycol (meth) acrylate are preferable, and from the viewpoint of the raw material price of the monomer, styrene is more preferable, and styrene and phenoxyethylene glycol (meth) acrylate are used in combination. Is more preferable.
The content of the structural unit derived from the addition polymerizable monomer having an aromatic group is preferably 55% by mass or more, more preferably 70% by mass or more, more preferably 85% by mass or more, more preferably in the segment (A2). Is 90% by mass or more, more preferably substantially 100% by mass.

  Mass ratio of the total amount of unsaturated aliphatic carboxylic acid and unsaturated alicyclic carboxylic acid among the raw material monomers of segment (A2) and segment (A1) [segment (A2) / unsaturated group of segment (A1) The total of the above-mentioned components] is preferably 1/1 to 15/1, more preferably 1/1 to 10/1, and further preferably 2/1 to 5/1, from the viewpoint of solvent resistance.

<Production of graft polymer>
When the resin constituting the resin particle (A) is a graft polymer, the method for producing the graft polymer includes a non-aromatic carbon-carbon unsaturated bond by polycondensing an alcohol component and a carboxylic acid component. A method of preparing a polyester resin (a1) (hereinafter also referred to as “resin (a1)”) and subjecting the addition polymerizable monomer (a2) to addition polymerization in the presence of the polyester resin (a1) is preferable.

(Polyester resin (a1))
The resin (a1) is a polyester resin having a non-aromatic carbon-carbon unsaturated bond obtained by condensation polymerization of an alcohol component and a carboxylic acid component, and the main chain segment (A1) made of the polyester resin. Is preferable. The “non-aromatic carbon-carbon unsaturated bond” is derived from one or more selected from the unsaturated aliphatic carboxylic acids and unsaturated alicyclic carboxylic acids described above.

  The suitable structure and suitable content of the alcohol component of the resin (a1) are the same as those in the segment (A1).

The polyester resin (a1) is produced, for example, by subjecting the alcohol component and the carboxylic acid component to condensation polymerization at a temperature of 180 to 250 ° C. in an inert gas atmosphere, if necessary, using an esterification catalyst. be able to.
From the viewpoint of heat resistance and control of the particle size of the resin particles, the polyester preferably has a sharp molecular weight distribution, and is preferably subjected to polycondensation using an esterification catalyst. Examples of the esterification catalyst include metal compounds such as tin catalyst, titanium catalyst, antimony trioxide, zinc acetate, and germanium dioxide. From the viewpoint of the reaction efficiency of the esterification reaction in the synthesis of the polyester, a tin catalyst is preferable. As a tin catalyst, dibutyltin oxide, di (2-ethylhexane) acid tin, a salt thereof and the like are preferably used, and dibutyltin oxide is more preferably used. Moreover, you may use together a radical polymerization inhibitor.

From the viewpoint of heat resistance, the softening point of the resin (a1) is preferably 80 to 165 ° C, and the glass transition temperature is preferably 50 to 85 ° C.
From the viewpoint of controlling the particle size of the resin particles, the acid value of the resin (a1) is 5 to 40 mgKOH / g, preferably 5 to 35 mgKOH / g, more preferably 5 to 30 mgKOH / g, and still more preferably 15 ~ 25 mg KOH / g.
The glass transition temperature, softening point, and acid value can all be obtained by appropriately adjusting the type of monomer used, the blending ratio, the temperature of condensation polymerization, and the reaction time.
Further, from the viewpoint of film forming property, the number average molecular weight of the resin (a1) is preferably 1,000 to 10,000, more preferably 2,000 to 8,000.

(Addition polymerizable monomer (a2))
The addition polymerizable monomer (a2) used in the present invention is as described above.

(Polymerization of graft polymer)
There is no limitation on the polymerization method of the graft polymer, a method in which the resin (a1) and the monomer (a2) are directly mixed and polymerized, a method in which the resin (a1) and the monomer (a2) are dissolved in an organic solvent, and the like. However, it is preferably obtained by a method having the following steps (1) and (2).
Step (1): Step of mixing the polyester resin (a1) with an aqueous medium to obtain an aqueous dispersion of the polyester resin (a1) Step (2): Adding to the aqueous dispersion obtained in Step (1) A step of adding a polymerizable monomer (a2) and polymerizing to obtain a graft polymer (hereinafter also referred to as “graft polymer (A)”) to obtain an aqueous dispersion containing the graft polymer (A)

[Step (1)]
Step (1) is a step of mixing the polyester resin (a1) with an aqueous medium to obtain an aqueous dispersion of the polyester resin (a1).
The aqueous medium is a medium containing water as a main component, that is, a medium having a water content of 50% by mass or more. From the viewpoint of environmental safety, the content of water in the aqueous medium is preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably substantially 100% by mass. Examples of components other than water include organic solvents that dissolve in water, such as alcohol solvents such as methanol, ethanol, isopropanol, and butanol; ketone solvents such as acetone and methyl ethyl ketone; and ether solvents such as tetrahydrofuran.

  As a method for dispersing the polyester resin (a1) in the aqueous medium, the polyester resin (a1) is dissolved in a ketone solvent, a neutralizing agent described later is added to ionize the carboxy group of the polyester resin (a1), and then A method of phase change to an aqueous system by adding water, preferably a method of adding a water and then distilling off the ketone solvent to phase-change to an aqueous system.

  In this step, as a method for adjusting the volume-median particle size of the polyester resin particles in the aqueous dispersion of the polyester resin (a1), stirring force, amount and type of activator, temperature, amount and type of neutralizing agent The method of adjusting by changing the quantity and kind of a solvent 1 or more is mentioned. Among these, since the particle diameter can be adjusted without affecting the resulting coating film, a method of adjusting by changing the stirring force is preferable.

More specifically, for example, a reactor equipped with a stirrer, a reflux condenser, a thermometer, a dropping funnel and a nitrogen gas introduction pipe is prepared, and the neutralizing agent is added to the polyester resin (a1) dissolved in the ketone solvent. Etc., ionize the carboxy group (not necessary if already ionized), then add water and phase invert to the aqueous system. Preferably, after adding water, the ketone solvent is distilled off to the aqueous system. Phase inversion.
The dissolving operation of the polyester resin (a1) in the ketone solvent and the subsequent addition of the neutralizing agent are usually performed at a temperature equal to or lower than the boiling point of the ketone solvent. Examples of the water used include deionized water.
Examples of the ketone solvent include acetone, methyl ethyl ketone, diethyl ketone, dipropyl ketone, methyl isobutyl ketone, and methyl isopropyl ketone. From the viewpoint of the solubility of the polyester resin (a1) and the ease of distilling off the solvent, methyl ethyl ketone is preferred.

  Examples of the neutralizing agent include aqueous alkaline solutions such as aqueous ammonia and sodium hydroxide, allylamine, isopropylamine, diisopropylamine, ethylamine, diethylamine, triethylamine, 2-ethylhexylamine, tri-n-octylamine, t-butylamine, sec-butylamine, propylamine, methylaminopropylamine, dimethylaminopropylamine, n-propanolamine, butanolamine, 5-amino-4-octanol, monoethanolamine, N, N-dimethylethanolamine, isopropanolamine, neopen Examples include amines such as tanolamine, diglycolamine, ethylenediamine, and piperazine, and ammonia water is preferable. The usage-amount of a neutralizing agent should just be the quantity which can neutralize the acid value of a polyester resin (a1) at least.

[Step (2)]
In step (2), the addition-polymerizable monomer (a2) is added to the aqueous dispersion obtained in step (1) and polymerized to obtain a graft polymer (A), and the aqueous dispersion containing the graft polymer (A) This is a step of obtaining a liquid (hereinafter also referred to as “aqueous dispersion (A)”).
First, the addition polymerizable monomer (a2) is added to the aqueous dispersion of the polyester resin (a1). The addition amount is a mass ratio of the polyester resin (a1) and the addition polymerizable monomer (a2) [polyester resin (a1) / addition polymerizable monomer (a2)], preferably 55/45 to 95/5, more preferably Is 65/35 to 95/5, more preferably 75/25 to 95/5. The mass ratio is preferably 55/45 or more, more preferably 65/35 or more, further preferably 75/25 or more, and preferably 95/5 or less, more preferably 65/35 or more. 35 or less, more preferably 75/25 or less.
Further, from the viewpoint of stirring efficiency, water or the like may be further added.

Next, the addition polymerizable monomer (a2) is polymerized in the presence of the polyester resin (a1).
In the polymerization, a known radical polymerization initiator, a crosslinking agent and the like are added as necessary. As the radical polymerization initiator, a water-soluble radical polymerization initiator is preferably used, more preferably a persulfate salt, and still more preferably sodium persulfate.
The polymerization reaction is advanced by heating a mixed solution containing the polyester resin (a1) and the addition polymerizable monomer (a2). The polymerization temperature depends on the type of polymerization initiator used, but for example, when sodium persulfate is used, it is preferably 60 to 100 ° C., more preferably 70 to 90, from the viewpoint of efficiently performing the polymerization reaction. The reaction time is preferably 1 to 10 hours, more preferably 3 to 8 hours, and even more preferably 5 to 7 hours.

The solid content concentration of the aqueous dispersion (A) is preferably 10 to 50% by mass, more preferably 15 to 40% by mass, and still more preferably 20 to 30% by mass, from the viewpoint of the dispersibility and productivity of the resin particles. It is.
The pH of the aqueous dispersion (A) at 25 ° C. is preferably 5 to 10, more preferably 6 to 9, and still more preferably 7 to 9 from the viewpoint of storage stability of the aqueous dispersion (A). is there.

<Polyester resin particles (B)>
The polyester resin particles (B) used in the present invention have a volume-median particle size of 0.01 to 0.05 μm from the viewpoint of film forming properties.
From this point of view, the lower limit of the volume median particle size is 0.01 μm, preferably 0.02 μm, and the upper limit of the volume median particle size is 0.05 μm, preferably 0. 0.04 μm, more preferably 0.03 μm. The volume median particle size is preferably 0.02 to 0.04 μm, and more preferably 0.02 to 0.03 μm.
The method for adjusting the volume median particle size of the resin particles (B) to the above range is not limited. For example, the stirring power when emulsifying the polyester resin in an aqueous medium, the amount and type of the activator, A method of adjusting the temperature, the amount and type of the neutralizing agent, the amount and type of the solvent by changing one or more, a method of adjusting the acid value of the polyester-based resin, and one or more types of monomers Can be mentioned. Among these, since the particle size can be adjusted without affecting the resulting coating film, the stirring power, the amount and type of the activator, the temperature, the amount and type of the neutralizing agent, and the amount and type of the solvent are one. A method of adjusting by changing the above is preferable, and a method of adjusting by changing the stirring force is more preferable.

Further, the storage elastic modulus G ′ (B) at 200 ° C. of the resin particles (B) is related to the storage elastic modulus G ′ (A) of the resin particles (A) at 200 ° C. from the viewpoint of film forming properties. The following is preferable. That is, the ratio (G ′ (A) / G ′ (B)) of the storage elastic modulus G ′ at 200 ° C. between the resin particles (A) and the resin particles (B) is preferably 0.01 to 500. 1 to 500 is more preferable, and 1 to 50 is still more preferable.
The storage elastic modulus G ′ at 200 ° C. can be measured by the method described in the examples.

The resin constituting the resin particles (B) is a polyester-based resin, and may be a resin composed only of polyester or a modified polyester resin, but from the viewpoint of solvent resistance, from a polyester resin A graft polymer comprising a main chain segment (B1) (hereinafter also referred to simply as “segment (B1)”) and a side chain segment (B2) (hereinafter also simply referred to as “segment (B2)”) comprising an addition polymerization resin. It is preferable that In addition, also when it is resin which consists only of polyester, the same composition as a segment (B1) is preferable.
The segment (B1) can have the same composition as the segment (A1) and the segment (B2) can have the same composition as the segment (A2).

The glass transition temperature of the resin particles (B) is preferably 50 ° C. or higher, more preferably 50 to 100 ° C., further preferably 50 to 80 ° C., and further preferably 60 to 80 ° C., from the viewpoint of heat resistance. .
From the viewpoint of heat resistance, the glass transition temperature of the resin particles (A) is preferably higher than the glass transition temperature of the resin particles (B), and the difference is more preferably 0.5 to 10 ° C.
In addition, the resin particle (B) may be comprised from components other than resin, such as a resin component and an activator other than the case where it is comprised only by resin. In the present invention, the storage elastic modulus (G ′) and glass transition temperature at 200 ° C. of the resin particles (B) are those containing components other than the resin in the resin particles (B) ( B) The whole measured value measured by the measuring method described in the examples.

  A preferable production method of the polyester resin particles (B) is also the same as that of the polyester resin particles (A).

<Aqueous medium>
The water-based coating composition of the present invention contains an aqueous medium. The details of this aqueous medium are as described above.

<Water-based paint composition>
The mass ratio (A) / (B) of the resin particles (A) to the resin particles (B) is 55/45 to 97/3 from the viewpoint of film forming properties and film drying properties, and 65/35 to 92 / 8 is preferable, and 75/25 to 85/15 is more preferable. When the ratio is less than 55/45, the film drying property is inferior, and when it exceeds 97/3, the film forming property is inferior.
The volume median particle size ratio (A) / (B) between the resin particles (A) and the resin particles (B) is preferably 3 or more, more preferably 4 or more, and still more preferably, from the viewpoint of improving the film forming property. It is 4.5 or more, more preferably 5 or more, preferably 18 or less, more preferably 15 or less, still more preferably 13 or less, and still more preferably 10 or less.

The solid content concentration in the water-based coating composition is preferably 10 to 50% by mass, more preferably 15 to 40% by mass, and still more preferably 20 to 30% by mass from the viewpoints of handleability and economy.
The total content of the resin particles (A) and the resin particles (B) in the component excluding the aqueous medium of the aqueous coating composition is preferably 60% by mass or more, more preferably 80% by mass or more, and Preferably it is 90 mass% or more.
The total amount of the resin particles (A) and the resin particles (B) in the water-based coating composition is preferably 10 to 50% by mass, more preferably 15 to 40% by mass, from the viewpoints of handleability and economy. Preferably it is 20-30 mass%.

  The volume-median particle size of the total particles composed of the resin particles (A) and the resin particles (B) is from the viewpoint of improving the film forming property and the film drying property, and improving the heat resistance and solvent resistance of the resulting coating film. Preferably it is 0.06-0.40 micrometer, More preferably, it is 0.08-0.30 micrometer, More preferably, it is 0.1-0.2 micrometer, More preferably, it is 0.12-0.17 micrometer More preferably 0.13 to 0.16 μm.

[Aqueous Coating Composition of Second Embodiment]
A second aspect of the aqueous coating composition of the present invention is an aqueous coating composition containing polyester resin particles, wherein the polyester resin particles have a volume median particle size of 0.06 to 0.40 μm, The mass ratio (x) / (y) of the resin component (x) that precipitates when centrifuged under the following centrifugation conditions and the resin component (y) that does not precipitate is 55/45 to 97/3, And it is a water-based coating composition whose volume median particle diameter of resin component (y) is 0.01-0.05 micrometer.
Centrifugation conditions are such that a 20% by mass aqueous dispersion of polyester resin particles is used, followed by centrifugation at 25 ° C. and a relative centrifugal acceleration of 3.5 × 10 ⁴ G for 5 hours.
In the second embodiment, resin particles having different particle sizes may be mixed, or polyester resin particles having a wide particle size distribution may be used. When resin particles having different particle diameters are mixed, the aqueous coating composition in the first aspect is also included, and the aqueous coating composition in the first aspect is preferable.

  The resin constituting the polyester resin particles contained in the second embodiment of the water-based coating composition of the present invention is a polyester resin, may be a resin composed only of polyester, or is a modified polyester resin. However, from the viewpoint of solvent resistance, it is preferably a graft polymer composed of a main chain segment made of a polyester resin and a side chain segment made of an addition polymerization resin, like the resin particles (A). A preferable composition in the case of a graft polymer is the same as that of the resin particles (A).

  The volume-median particle size of the polyester resin particles contained in the second embodiment of the water-based coating composition of the present invention is improved in film forming property and film drying property, and improved in heat resistance and solvent resistance of the resulting coating film. From this point of view, it is 0.06 to 0.40 μm, preferably 0.08 to 0.30 μm, more preferably 0.10 to 0.20 μm, still more preferably 0.12 to 0.17 μm. More preferably 0.13 to 0.16 μm.

  In the second aspect of the water-based coating composition of the present invention, from the viewpoint of improving the film-forming property and film-drying property, and improving the heat resistance and solvent resistance of the resulting coating film, it was centrifuged under the above-mentioned centrifugal separation conditions. The mass ratio (x) / (y) of the resin component (x) that precipitates to the resin component (y) that does not precipitate is 55/45 to 97/3, preferably 65/35 to 92/8, 75/25 to 85/15 is more preferable.

  The volume-median particle size of the resin component (y) that does not precipitate when centrifuged under the above-mentioned centrifugation conditions is improved in film-forming property and film-drying property, and heat resistance and solvent resistance of the resulting coating film. From the viewpoint of improvement, the thickness is 0.01 to 0.05 μm, preferably 0.02 to 0.04 μm, and more preferably 0.02 to 0.03 μm.

  The volume-median particle size of the resin component (x) that precipitates when centrifuged under the above-mentioned centrifugal conditions is improved in film-forming properties and membrane drying properties, and heat resistance and solvent resistance of the resulting coating film. From the viewpoint of improvement, the thickness is preferably 0.07 to 0.40 μm, more preferably 0.1 to 0.30 μm, still more preferably 0.10 to 0.20 μm, and still more preferably 0.13 to 0.17 μm. is there.

[Method for producing water-based coating composition]
Although there is no restriction | limiting in the manufacturing method of the water-system coating composition of this invention, It is preferable to obtain by the method containing following process (1)-(3).
Step (1): A polyester resin (a1) having a non-aromatic carbon-carbon unsaturated bond is prepared, the polyester resin (a1) is mixed with an aqueous medium, and an aqueous dispersion of the polyester resin (a1) is prepared. Step (2): Addition-polymerizable monomer (a2) is added to the aqueous dispersion of polyester resin (a1) obtained in step (1) and polymerized to obtain an aqueous dispersion of graft polymer. Step of obtaining an aqueous dispersion of polyester resin particles (A) having a volume median particle size of 0.07 to 0.40 μm Step (3): The aqueous dispersion obtained in step (2) and polyester resin particles ( Step of mixing the aqueous dispersion of B) to obtain a water-based coating composition Among these steps, Steps (1) and (2) are as described in the production of the resin particles (A).
Step (3) is a step of mixing the respective aqueous dispersions of the resin particles (A) and the resin particles (B), but there is no limitation on the mixing method.

[Coating agent]
The coating agent of the present invention contains the above water-based paint composition. Although this coating agent may consist only of a water-system coating composition, the 1 type (s) or 2 or more types of various additives may be mix | blended.
Examples of the various additives include dispersants, viscosity modifiers, antifoaming agents, leveling agents, preservatives, deterioration inhibitors, stabilizers, and antifreeze agents.
As the viscosity modifier, a fatty acid ester of polyethylene glycol such as polyethylene glycol monostearate is preferable.

[paint]
The coating material of this invention contains the said water-system coating composition. This paint contains a pigment (colorant) in addition to the water-based paint composition, and, as in the case of the coating agent, one or more of various additives may be blended.
There is no restriction | limiting in particular in a pigment, For example, a phthalocyanine is mentioned, More preferably, it is a copper phthalocyanine.

[Coating film forming method]
There is no restriction | limiting in particular in the method of forming a coating film using the said coating material, It can form suitably by drying after coating a coating material to a target object. In addition, since the paint of the present invention is excellent in film forming property, after coating using the paint, the resin particles contained in the paint are dried below the glass transition temperature of the resin particles having the lowest glass transition temperature. Thus, a coating film can be obtained.
The drying temperature is preferably not more than the glass transition temperature of the resin particles having the lowest glass transition temperature among the resin particles contained in the paint from the viewpoint of preventing environmental properties and resin deterioration, and is 10 ° C. or higher. More preferably, it is low.

  The present invention discloses the following water-based paint composition, coating agent, paint, coating film forming method, and water-based paint composition manufacturing method with respect to the above-described embodiments.

<1> The volume median particle size is 0.07 to 0.40 μm, preferably 0.07 μm or more, more preferably 0.1 μm or more, still more preferably 0.12 μm or more, and still more. Preferably it is 0.13 μm or more, more preferably 0.14 μm or more, and preferably 0.40 μm or less, more preferably 0.30 μm or less, still more preferably 0.2 μm or less, Still more preferably, it is 0.18 micrometer or less, More preferably, it is 0.16 micrometer or less, Preferably it is 0.1-0.30 micrometer, More preferably, it is 0.12-0.2 micrometer, More preferably Is 0.13-0.18 μm, more preferably 0.14-0.16 μm polyester resin particles (A), and volume median particle size is 0.01-0.05. m, preferably 0.02 μm or more, preferably 0.05 μm or less, more preferably 0.04 μm or less, still more preferably 0.03 μm, and preferably 0.02 to 0 The polyester resin particles (B) having a diameter of 0.04 μm, more preferably 0.02 to 0.03 μm, are 55/45 to 97/3, preferably 65/35 to 92/8, more preferably 75/25. A water-based coating composition blended at a mass ratio of ˜85 / 15.

<2> The glass transition temperature of the resin constituting the resin particles (A) is higher than the glass transition temperature of the resin constituting the resin particles (B), and preferably the difference between these glass transition temperatures is 0.5 to 10 ° C. The water-based coating composition according to <1>.
<3> The water system according to <1> or <2>, wherein the resin constituting the resin particle (A) has a storage elastic modulus (G ′) at 200 ° C. of 10 to 1000000 Pa, preferably 1000 to 100000 Pa. Paint composition.
<4> Ratio of storage elastic modulus (G ′) at 200 ° C. between the resin constituting the resin particles (A) and the resin constituting the resin particles (B) (G ′ (A) / G ′ (B)) However, Preferably it is 0.01-500, More preferably, it is 1-500, More preferably, it is 1-50, The water-based coating composition in any one of <1>-<3>.
<5> The resin constituting the resin particle (A) is a graft polymer composed of a main chain segment (A1) made of a polyester resin and a side chain segment (A2) made of an addition polymerization resin, <1> to <4 > The water-based coating composition according to any one of the above.

<6> The mass ratio [segment (A1) / segment (A2)] of the segment (A1) to the segment (A2) is preferably 55/45 or more, more preferably 65/35 or more, and still more preferably. Is 75/25 or more, preferably 95/5 or less, preferably 55/45 to 95/5, more preferably 65/35 to 95/5, more preferably 75/25 to 95/5. The water-based coating composition according to <5>.
The content of the alkylene oxide adduct of bisphenol A in the <7> segment (A1) is 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, and preferably 90 <5> or a polyester resin obtained by polycondensation of an alcohol component and a carboxylic acid component, which are not more than mol%, more preferably not more than 85 mol%, still more preferably not more than 80 mol%, <6> The water-based coating composition according to the above.
<8> The resin constituting the resin particle (B) is a graft polymer composed of a main chain segment (B1) made of a polyester resin and a side chain segment (B2) made of an addition polymerization resin, <1> to <7 > The water-based coating composition according to any one of the above.
<9> The mass ratio [segment (B1) / segment (B2)] of the segment (B1) and the segment (B2) is preferably 55/45 or more, more preferably 65/35 or more, and still more preferably. Is 75/25 or more, preferably 95/5 or less, preferably 55/45 to 95/5, more preferably 65/35 to 95/5, more preferably 75/25 to 95/5. The water-based paint composition according to <8>.
The content of the alkylene oxide adduct of bisphenol A in the <10> segment (B1) is 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, and preferably 90 <8> or a polyester resin obtained by polycondensation of an alcohol component and a carboxylic acid component that are not more than mol%, more preferably not more than 85 mol%, and still more preferably not more than 80 mol%, <9> The water-based coating composition according to <9>.

<11> The volume median particle size of the total particles composed of the resin particles (A) and the resin particles (B) is 0.06 to 0.40 μm, preferably 0.08 to 0.30 μm, more preferably. Is 0.1 to 0.2 μm, more preferably 0.12 to 0.17 μm, and still more preferably 0.13 to 0.16 μm, according to any one of <1> to <10> Water-based paint composition.
<12> Polyester resin particles (A) having a volume median particle size of 0.07 to 0.40 μm and polyester resin particles (B) having a volume median particle size of 0.01 to 0.05 μm. 55/45 to 97/3, preferably 65/35 to 92/8, more preferably 75/25 to 85/15, and a water-based coating composition comprising polyester resin particles ( A) is a graft polymer composed of a main chain segment (A1) made of a polyester resin and a side chain segment (A2) made of polystyrene, and the polyester resin particles (B) are a main chain segment (B1) made of a polyester resin and polystyrene. The aqueous coating composition according to any one of <1> to <11>, which is a graft polymer comprising a side chain segment (B2) comprising:
In the carboxylic acid component of the <13> segment (A1), the content of the carboxylic acid having a non-aromatic carbon-carbon unsaturated bond is 5 to 30 mol%, preferably 7 to 25 mol%, more preferably. The water-based coating composition according to <12>, which is 8 to 20 mol%.
In the carboxylic acid component of <14> segment (A1), the content of the aromatic dicarboxylic acid is 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more, and preferably 95 mol. % Or less, more preferably 90 mol% or less, and still more preferably 88 mol% or less, the water-based coating composition according to <12> or <13>.
<15> In the carboxylic acid component of the segment (A1), the content of the carboxylic acid having a non-aromatic carbon-carbon unsaturated bond is 5 to 30 mol%, preferably 7 to 25 mol%, more preferably. The aqueous coating composition according to any one of <12> to <14>, which is 8 to 20 mol%.

In the carboxylic acid component of the <16> segment (A1), the content of the aromatic dicarboxylic acid is 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more, and preferably 95 mol%. %, More preferably, it is 90 mol% or less, More preferably, it is 88 mol% or less, The water-based coating composition in any one of <12>-<15>.
<17> A water-based coating composition containing polyester resin particles, wherein the polyester resin particles have a volume-median particle size of 0.06 to 0.40 μm, preferably 0.08 to 0.30 μm. More preferably 0.1 to 0.2 μm, still more preferably 0.12 to 0.17 μm, still more preferably 0.13 to 0.16 μm, and centrifugation is performed under the following centrifugation conditions. The mass ratio (x) / (y) of the resin component (x) that precipitates when separated and the resin component (y) that does not precipitate is 55/45 to 97/3, preferably 65/35 to 92. / 8, more preferably 75/25 to 85/15, and the volume median particle size of the resin component (y) is 0.01 to 0.05 μm, preferably 0.02 to 0.0. 04 μm, more preferably 0.02 to 0.0 A [mu] m, water-based coating composition.
Centrifugation conditions: After making a 20% by mass aqueous dispersion of polyester resin particles, centrifugation is performed at 25 ° C. and a relative centrifugal acceleration of 3.5 × 10 ⁴ G for 5 hours.
The volume median particle size of <18> resin component (x) is preferably 0.07 to 0.40 μm, more preferably 0.1 to 0.30 μm, still more preferably 0.10 to 0.20 μm, and still more. The aqueous coating composition according to <17>, preferably 0.13 to 0.17 μm.
<19> A coating agent containing the water-based paint composition according to any one of <1> to <18>.
<20> A paint containing the water-based paint composition according to any one of <1> to <18>.

<21> After coating using the paint according to <20>, among the resin particles contained in the paint, the glass transition temperature is not more than the glass transition temperature of the lowest resin particle, preferably the lowest resin particle A method for forming a coating film, wherein the film is dried at a temperature lower than the glass transition temperature by 10 ° C. or more.
<22> The method for producing an aqueous coating composition according to any one of <1> to <18>, comprising the following steps (1) to (3).
Step (1): A polyester resin (a1) having a non-aromatic carbon-carbon unsaturated bond is prepared, the polyester resin (a1) is mixed with an aqueous medium, and an aqueous dispersion of the polyester resin (a1) is prepared. Step (2): Addition-polymerizable monomer (a2) is added to the aqueous dispersion of polyester resin (a1) obtained in step (1) and polymerized to obtain an aqueous dispersion of graft polymer. Step of obtaining an aqueous dispersion of polyester resin particles (A) having a volume median particle size of 0.07 to 0.40 μm Step (3): The aqueous dispersion obtained in step (2) and polyester resin particles ( Step (23) of mixing the aqueous dispersion of B) to obtain an aqueous coating composition <23> The water content in the aqueous medium is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more. More preferably Is 100 mass%, The manufacturing method of the water-based coating composition as described in <22>.
<24> In step (1), the polyester resin (a1) is dissolved in a ketone solvent, a neutralizing agent is added to ionize the carboxy group of the polyester resin (a1), and then water is added to invert the phase to an aqueous system. The aqueous system according to <22> or <23>, wherein the polyester resin (a1) is dispersed in the aqueous medium by a method, preferably a method in which water is added and then the ketone solvent is distilled off and the phase is changed to an aqueous system. A method for producing a coating composition.
<25> The method for producing an aqueous coating composition according to any one of <22> to <24>, wherein the neutralizing agent is an alkaline aqueous solution.

<26> In the step (2), the mass ratio of the polyester resin (a1) and the addition polymerizable monomer (a2) [polyester resin (a1) / addition polymerizable monomer (a2)] is 55/45 to 95/5. , Preferably 65/35 to 95/5, more preferably 75/25 to 95/5, preferably 55/45 or more, more preferably 65/35 or more, still more preferably 75/25 or more. The aqueous paint composition according to any one of <22> to <25>, which is preferably 95/5 or less, more preferably 65/35 or less, and further preferably 75/25 or less. Manufacturing method.
<27> In the step (2), the polymerization temperature during the polymerization is 60 to 100 ° C., preferably 70 to 90 ° C., the reaction time is 1 to 10 hours, preferably 3 to 8 hours, More preferably, it is 5 to 7 hours, The manufacturing method of the water-based coating composition in any one of <22>-<26>.

  Hereinafter, the present invention will be described more specifically with reference to examples and the like. In the following examples and the like, each physical property was measured by the following method.

[Acid value of resin]
The measurement solvent was measured according to JIS K0070, except that the mixed solvent of ethanol and ether was changed to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

[Softening point of resin]
Using a flow tester (manufactured by Shimadzu Corporation, trade name: CFT-500D), a 1 g sample was heated at a heating rate of 6 ° C./min. Extruded from a 1 mm nozzle. The amount of plunger drop of the flow tester was plotted against the temperature, and the temperature at which half of the sample flowed out was taken as the softening point.

[Glass transition temperature of resin]
Each aqueous dispersion was freeze-dried at −10 ° C. for 9 hours using a freeze dryer (manufactured by Tokyo Rika Kikai Co., Ltd., trade name: FDU-2100) to prepare a sample for measuring the glass transition temperature.
Using a differential scanning calorimeter (trade name: “Q-100” manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of a sample was weighed into an aluminum pan and heated to 200 ° C. Then, the sample was cooled to 0 ° C. at a temperature decrease rate of 10 ° C./min to prepare a measurement sample. Then, the temperature is increased at a rate of temperature increase of 10 ° C / min, and the glass transition takes place at the intersection of the base line extension below the endothermic peak temperature and the tangent that indicates the maximum slope from the peak rise to the peak apex. It was temperature.

[Volume Median Particle Size (D ₅₀ ) of Resin Particles and Colorant Particles in Aqueous Dispersion]
A volume-median particle size (D ₅₀ ) was measured under the following conditions using a dynamic light scattering type particle size measuring machine (trade name: “ZETASIZER NANO ZS” manufactured by Malvern).
Solid content concentration: 0.1% by mass
Measurement temperature: 25 ° C
Medium: Water Measurement cell: Glass Cuvette
Laser specification: He-Ne, 4mW, 633nm
Detection optical system: NIBS, 173 ° C.
Number of measurements: 10 times Isothermal time: 5 minutes Analysis software: Zeta Sizer Software 6.2
Analysis method: General Purpose Mode (cumulant method)

[Storage modulus (G ′) of resin at 200 ° C.]
It measures using a viscoelasticity measuring apparatus (rheometer) ARES (made by TA company).
The storage elastic modulus (G ′) is measured by a rheometer (ARES, manufactured by TA Instruments) (Strain: 0.05%, Frequency: 6.28 rad / sec, Auto strain). A parallel plate with a diameter of 25 mm was heated to 140 ° C. and allowed to stand, and 1 g of the sample was placed on the parallel plate at 140 ° C. and sandwiched between the upper and lower plates, and then heated to 210 ° C. at a rate of 5 ° C./min. A storage elastic modulus (G ′) at 200 ° C. was obtained.

[Solid content concentration of aqueous dispersion]
Using an infrared moisture meter (trade name: FD-230, manufactured by Ketsu Scientific Laboratory Co., Ltd.), 5 g of an aqueous dispersion was measured at a drying temperature of 150 ° C. and a measurement mode 96 (monitoring time 2.5 minutes / variation width 0.05%). ), And the water content (mass%) of the aqueous dispersion was measured. The solid content concentration was calculated according to the following formula.
Solid content concentration (% by mass) = 100-M
M: moisture (mass%) of the aqueous dispersion = [(W−W ₀ ) / W] × 100
W: Sample mass before measurement (initial sample mass)
W ₀ : Mass of sample after measurement (absolute dry mass)

[Method of Centrifugation of Aqueous Dispersion of Polyester Resin Particles]
Using a high-speed centrifuge (made by SIGMA, Germany, trade name: “3K30C”), the precipitated component and the non-precipitated component of the resin particles in the aqueous dispersion of the polyester resin were separated under the following conditions.
Temperature: 25 ° C
Sample mass: 20 g
Rotor: 12158-H
Sample cell: Nalgene Centrifuge wear 3119-0030
Sample amount: 20g
Rotational speed: 20000 rpm
RCF (relative centrifugal acceleration): 3.5 × 10 ⁴ G
Time: 5 hours

[Method for Measuring Volume Median Particle Size (D ₅₀ ) of Resin Particle (b) as Non-Precipitated Component After Centrifugation]
Immediately after the centrifugation operation was stopped, the entire supernatant (transparent portion) was quickly collected with a Pasteur pipette and measured by the same method as the above-mentioned “volume median particle size of resin particles in aqueous dispersion”.

[Mass ratio (a) / (b) of resin particles (a) to be precipitated and resin particles (b) to be not precipitated)]
Immediately after stopping the centrifugation operation, the entire supernatant (transparent portion) was quickly collected with a Pasteur pipette. The total mass of the supernatant liquid was measured, and the solid content concentration of the supernatant liquid was measured using the same method as the “solid content concentration of aqueous dispersion”.
From the total mass of the supernatant and the solid content concentration of the supernatant, the mass of the resin component (y) present in the supernatant was determined. Further, by subtracting the mass of the resin component (y) from the total mass of the resin particles used when the aqueous dispersion of polyester resin particles is produced, the mass of the resin component (x) present in the precipitation component is obtained. Asked. From these values, the mass ratio (x) / (y) between the resin component (x) that precipitates and the resin component (y) that does not precipitate was determined.

Production Examples 1-5, 7, 8
(Production of polyester resins P1-5, 7 and 8)
The raw material monomer of polyester resin excluding fumaric acid shown in Table 1 and 20 g of dibutyltin oxide were placed in a 10 L four-necked flask equipped with a thermometer, stirrer, flow-down condenser and nitrogen inlet tube, and in a nitrogen atmosphere The temperature was raised to 180 ° C. in a mantle heater, and then raised to 230 ° C. over 5 hours. Then, after reacting at 230 degreeC for 5 hours, it cooled to 180 degreeC and added the fumaric acid. After heating up to 200 ° C. over 3 hours, the reaction was carried out at 200 ° C. and 8 kPa until the softening point measured according to ASTM D36-86 reached the temperature shown in Table 1, and polyester resins P1 to 5, 7 and 8 was obtained.
Table 1 shows the physical properties and the like of the obtained polyester resins P1 to 5, 7, and 8.

Production Example 6
(Production of polyester resin P6)
Dehydration pipe equipped with a fractionating pipe through which a raw material monomer of polyester resin excluding fumaric acid and 20 g of dibutyltin oxide shown in Table 1 were passed through a thermometer, a stainless steel stirring rod, hot water at 98 ° C., a flow-down condenser, and nitrogen introduction The flask was placed in a four-necked flask with an internal volume of 10 L equipped with a tube, heated to 180 ° C. in a mantle heater in a nitrogen atmosphere, and then heated to 230 ° C. over 8 hours. Then, after reacting at 230 degreeC for 5 hours, it cooled to 180 degreeC and added the fumaric acid. After heating up to 200 degreeC over 3 hours, it was made to react at 200 degreeC and 8 kPa until the softening point measured according to ASTM D36-86 reached the temperature shown in Table 1, and polyester resin P6 was obtained.
Table 1 shows the physical properties and the like of the obtained polyester resin P6.

Production Examples 9-17
(Production of aqueous dispersion Em1-1 to Em1-9 containing polyester resin)
100 g of the polyester resin shown in Table 2, an anionic surfactant (trade name: “Neopelex G-15”, manufactured by Kao Corporation) as a solid content, 5 g are mixed with 100 g of methyl ethyl ketone and dissolved at 25 ° C. It was. Thereafter, 600 g of ion exchange water and 1.5 g of 25% ammonia water were mixed in a 2000 mL stainless steel beaker made of SUS304, and 30 ° C. using an ultrasonic homogenizer (product name: UP-400S manufactured by Dr. Heelscher, Germany). Distributed processing. Thereafter, the temperature was raised to 50 ° C., and methyl ethyl ketone was distilled off under reduced pressure. Thereafter, the solid content was adjusted to 20% by mass with ion-exchanged water to obtain an aqueous dispersion containing a polyester resin.
The average median particle size of the polyester resin particles in the aqueous dispersion was adjusted by changing the operating conditions of the homogenizer. The measurement results of the average median particle diameter are shown in Table 2.
Em1-1 (8 nm) is performed at 400 W for 1 hour, Em1-9 (455 nm) is performed at 50 W for 10 minutes, and other aqueous dispersions are conditions between 50 to 400 W, 10 minutes to 1 hour. Changed.

Production Examples 18-30
(Production of aqueous dispersion Em2-1 to Em8-2 containing polyester resin)
The polyester resin is used by performing the same operation as in Production Example 9 except that the polyester resin shown in Table 3 is used and the operating conditions of the homogenizer are changed between 50 to 400 W and 10 minutes to 1 hour. Aqueous dispersions Em2-1, Em2-2, Em3-1, Em3-2, Em4-1, Em4-2, Em5-1, Em5-2, Em6-1, Em6-2, Em7-1, Em7-2 , Em8-1 and Em8-2 were obtained. The measurement results of the average median particle diameter are shown in Table 3.

Production Examples 31-42
(Production of aqueous dispersion of graft polymers G1 to G12)
Addition of 600 g of an aqueous dispersion containing the polyester resin shown in Table 4 to the four-necked flask with an internal volume of 2 liters equipped with a nitrogen introduction tube, a reflux condenser, a dropping funnel, a stirrer, and a thermocouple, and the amount shown in Table 4 Styrene and phenoxyethyl methacrylate which are polymerizable monomers were charged and stirred for 30 minutes. Next, an amount of sodium persulfate shown in Table 4 was added under a nitrogen stream, and reacted at 80 ° C. for 6 hours. Thereafter, the remaining addition polymerizable monomer under reduced pressure was removed together with water. The mixture was cooled to room temperature, filtered through a 200-mesh wire mesh, adjusted to a solid content of 20% by mass with ion-exchanged water, and aqueous dispersions G1 to G12 containing a graft polymer were obtained.
Table 4 shows the physical properties and the like of the obtained aqueous dispersions G1 to G12.

Production Examples 43 to 56
(Production of aqueous dispersion of graft polymers g1 to g14)
Addition of 600 g of an aqueous dispersion containing the polyester resin shown in Table 5 to the four-necked flask having an internal volume of 2 liters equipped with a nitrogen introduction tube, a reflux condenser, a dropping funnel, a stirrer, and a thermocouple, and the amount shown in Table 5 A polymerizable monomer, styrene and phenoxyethyl methacrylate (PhEMA) were charged and stirred for 30 minutes. Next, an amount of sodium persulfate shown in Table 5 was added under a nitrogen stream, and reacted at 80 ° C. for 6 hours. Thereafter, the remaining addition polymerizable monomer under reduced pressure was removed together with water. The mixture was cooled to room temperature, filtered through a 200-mesh wire mesh, adjusted to a solid content of 20% by mass with ion-exchanged water, and aqueous dispersions g1 to g14 containing a graft polymer were obtained.
Table 5 shows the physical properties and the like of the obtained aqueous dispersions g1 to g14.

Production Example 57
(Production of colorant (pigment) dispersion)
50 g of copper phthalocyanine (manufactured by Dainichi Seika Kogyo Co., Ltd., model number: ECB-301), 5 g of nonionic surfactant (Emulgen 150, trade name, manufactured by Kao Corporation) and 200 g of ion-exchanged water are mixed, It was dissolved and dispersed for 10 minutes using a homogenizer to obtain a colorant dispersion. The volume median particle size was 120 nm.

Examples 1-21 and Comparative Examples 1-9
(Manufacture of water-based paint composition)
The aqueous dispersions G1 to G12 and g1 to g14 of the graft polymer were mixed in the ratios shown in Table 6 to produce an aqueous coating composition. For Comparative Examples 7 and 8, aqueous dispersions Em1-7 and Em8-2 were mixed in the ratios shown in Table 6 to produce water-based coating compositions.
Further, the obtained water-based coating composition was separated into a supernatant liquid (specific precipitation component) and a precipitation component by the above-described centrifugal separation method. These physical properties are shown in Table 7.

[Manufacturing and evaluation method of paint and coating agent]
(Film forming property)
95 g of the above water-based coating composition, 5.0 g of a 20% by weight solution of polyethylene glycol monostearate (Emanon 3199V, manufactured by Kao Corporation, viscosity modifier), polyoxyethylene lauryl ether (Emulgen 109P, manufactured by Kao Corporation, surfactant) A coating agent was prepared by mixing a 4 mass% solution of the agent.
The coating agent was applied to a PET film (Lumirror 75T60, Toray Industries, Inc.) cut to 10 cm × 10 cm so that the solid content after drying was 5.0 g / m ² . After coating, it was dried at 65 ° C. for 3 minutes.
Next, the film was placed on a black image having an image density of 1.60 measured using a reflection densitometer “RD-915” (manufactured by Macbeth), and the image density was measured.
The difference between the obtained image density and the image density (1.60) when an uncoated PET film was used was determined.
The smaller the difference in image density, the better the film formation, the less the irregular reflection of light, and the better the film forming property.

(Membrane drying)
95 g of the above water-based coating composition, 5.0 g of a 20% by weight solution of polyethylene glycol monostearate (Emanon 3199V, manufactured by Kao Corporation, viscosity modifier), polyoxyethylene lauryl ether (Emulgen 109P, manufactured by Kao Corporation, surfactant) A coating material was prepared by mixing a 4% by weight solution of the agent) and 5 g of the colorant dispersion.
The said coating material was apply | coated so that it might become 5.0 g / m < ² > as solid content after drying with respect to the aluminum plate 5cm x 10cm of thickness 0.5mm. After coating, plates were prepared that were dried at 65 ° C. for 2 minutes (2-minute dry sample), 65 ° C. for 3 minutes (3-minute dry sample), and 65 ° C. for 5 minutes (5-minute dry sample).
Paper (J paper manufactured by Fuji Xerox Co., Ltd.) was placed on the dried plate, and a weight was applied so as to be 20 g / cm ^2, and the plate was left for 1 minute. After being allowed to stand, the weight and the paper were removed, the paper surface was stained (blue deposit), and the film drying property was evaluated according to the following criteria.
A: There was no blue deposit regardless of which sample was used.
B: Only 2 minutes dry sample had blue deposits.
C: Only 5 minutes dry sample had no blue deposit.
D: There was a blue deposit regardless of which sample was used.

(Heat-resistant)
The paint used in the film drying evaluation was applied to a 5 mm × 10 cm aluminum plate having a thickness of 0.5 mm so that the solid content after drying was 5.0 g / m ² . After the application, a plate dried at 90 ° C. for 5 minutes was prepared.
Paper (Fuji Xerox J paper) is placed on the dried plate, loaded with a weight to 20 g / cm ² , and placed in a constant temperature bath at 70 ° C. and 50% relative humidity for 1 hour. Peeled off. The state at that time was evaluated for heat resistance according to the following criteria.
A: There was no noise and the entire surface was peeled off.
B: The entire surface was peeled off but there was an abnormal noise.
C: A part was stuck.
D: The entire surface was adhered.

(Solvent resistance)
A plate was prepared in the same manner as that used in the heat resistance evaluation.
Two sheets of white felt impregnated with methyl ethyl ketone were placed on the dried plate, pressed at a pressure of 20 g / cm ² , peeled off after 15 seconds and 30 seconds, and the heat resistance was evaluated based on the following criteria for the state of the felt surface. .
A: None of the blue deposits were present.
B: Only blue felt for 30 seconds had blue deposits.
C: In all cases, there was a blue deposit, but there was no sticking.
D: Only the felt placed for 30 seconds was attached.
E: All had blue deposits and felt adhered.

  The evaluation results are shown in Table 6.

  The paint and coating agent using the water-based paint composition obtained in the examples are superior in film forming property and film drying property compared to the paint and coating agent using the water-based paint composition obtained in the comparative example, It turns out that it is what was excellent also in the heat resistance of the obtained coating film, and solvent resistance.

  The water-based paint composition of the present invention and the paint containing it are excellent in both film-forming property and film-drying property, heat resistance of the coating film, solvent resistance, surface protection of various materials, It can be suitably used as a paint for coating used for decoration of appearance and a coating agent water-based paint composition.

Claims (11)

Polyester resin particles (A) having a volume median particle size of 0.07 to 0.40 μm and polyester resin particles (B) having a volume median particle size of 0.01 to 0.05 μm are 55/45 to 97 / The resin constituting the resin particles (A) is a graft polymer composed of a main chain segment (A1) made of a polyester resin and a side chain segment (A2) made of an addition polymerization resin. Ah is, the resin constituting the resin particles (B) is a graft polymer consisting of the side chain segments consisting the main chain segment (B1) and the addition polymerization resin consisting of a polyester resin (B2), aqueous coating composition.   The water-based coating composition of Claim 1 whose glass transition temperature of a resin particle (A) is higher than the glass transition temperature of a resin particle (B).   The water-based coating composition according to claim 1 or 2, wherein the resin particles (A) have a storage elastic modulus (G ') at 200 ° C of 10 to 1,000,000 Pa.   The ratio (G '(A) / G' (B)) of the storage elastic modulus (G ') at 200 ° C between the resin particles (A) and the resin particles (B) is 1 to 500. 4. The water-based paint composition according to any one of 3. The water-based coating composition according to any one of claims 1 to 4 , wherein the volume-median particle size of the total particles composed of the resin particles (A) and the resin particles (B) is 0.06 to 0.40 µm. Resin particles (A) having an elastic modulus (G ′) at 200 ° C. of 1000 to 100000 Pa, and a main chain segment (A1) comprising a polyester resin constituting a graft polymer containing an alkylene oxide adduct of bisphenol A The water-based coating composition according to any one of claims 1 to 5 , which is a condensation polymer of a component and a carboxylic acid component, and the glass transition temperature of the resin particles (B) is 50 ° C or higher. The water-based coating composition according to claim 6 , wherein the mass ratio (A) / (B) of the resin particles (A) to the resin particles (B) is 65/35 to 92/8. Coated tablets containing the additive further aqueous coating composition according to any one of claims 1-7. A paint further containing a colorant in the water-based paint composition according to any one of claims 1 to 7 . A coating film forming method, wherein after coating using the paint according to claim 9 , drying is performed at a temperature equal to or lower than the glass transition temperature of the resin particles having the lowest glass transition temperature among the resin particles contained in the paint. Following steps (1) to include a (3), method of manufacturing an aqueous coating composition according to any one of claims 1-7.
Step (1): A polyester resin (a1) having a non-aromatic carbon-carbon unsaturated bond is prepared, the polyester resin (a1) is mixed with an aqueous medium, and an aqueous dispersion of the polyester resin (a1) is prepared. Step (2): Addition-polymerizable monomer (a2) is added to the aqueous dispersion of polyester resin (a1) obtained in step (1) and polymerized to obtain an aqueous dispersion of graft polymer. Step of obtaining an aqueous dispersion of polyester resin particles (A) having a volume median particle size of 0.07 to 0.40 μm Step (3): The aqueous dispersion obtained in step (2) and polyester resin particles ( Step of mixing the aqueous dispersion of B) to obtain an aqueous coating composition