JP3237262B2 - Resin composition for water-based paint and article coated therewith - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel and useful aqueous resin composition containing a fluoroolefin copolymer emulsion and an article coated with the composition. More specifically, the present invention relates to an aqueous dispersion of a fluoroolefin-based copolymer having a specific composition, which comprises a fluoroolefin-based aqueous resin emulsion as a main component, and for the purpose of assisting dispersion of pigments in the composition. The present invention relates to an extremely practical resin composition for water-based paint, which comprises using an aqueous solution together with pigments, and an article coated with the resin composition for water-based paint.

[0002]

2. Description of the Related Art In the field of exterior coating materials, in recent years, there has been a great demand for coating materials which do not cause deterioration or discoloration over a long period of time.

[0003] With the main purpose of such use, in recent years,
Aqueous emulsion-based coating resin compositions for fluoroolefin copolymers are being studied.

[0004] However, such fluoroolefin copolymer emulsions have limitations in terms of formulation compared with conventional acrylic styrene emulsions and vinyl ester emulsions, and particularly, paint formulations with high pigment concentrations. When it comes to performing, there is a defect that gloss is hardly produced.

[0005] However, Japanese Patent Application Laid-Open No. 61-26167 discloses a method for solving the above-mentioned problems, which discloses a resin composition for a paint based on an emulsion copolymer composed of a fluoroolefin, an alkyl vinyl ether and a vinyl carboxylate. The material is disclosed, and as a coating material for exterior use, it can be applied to some extent, but is still insufficient in terms of adhesion to a substrate and pigment dispersibility.

As described above, as far as the prior art is concerned, a water-based paint composition containing a highly durable fluoroolefin unit as a main component has a problem in dispersibility of pigments. In fact, it was not possible to obtain a coating film having a high gloss like that of a vinyl ester emulsion.

[0007]

Accordingly, the pigment dispersibility, especially in the final coating film, is high without impairing the performances of the fluoroolefin-based water-based coating compositions known in the prior art. It is precisely the object of the present invention to provide a highly practical coating composition which gives a glossy one, which is the main object of the present invention.

[0008]

Means for Solving the Problems Accordingly, the present inventors have:
In view of the current situation, as a result of diligent and repeated studies, in order to obtain a high-gloss coating film, that is, to improve the pigment dispersibility , dispersed without using emulsifiers in the coating composition.
SUMMARY OF THE INVENTION The present invention has now been completed by finding that the above-mentioned problems can be achieved only by containing an aqueous dispersion and / or aqueous solution of a fluoroolefin-based copolymer which has been converted into water and / or water-soluble. It came to let.

That is, the present invention relates to a fluoroolefin-based aqueous resin emulsion (A) obtained by emulsion polymerization in the presence of emulsifiers, and a dispersion and / or water-soluble fluoroolefin-based aqueous resin emulsion containing no emulsifiers. An aqueous dispersion and / or aqueous solution (B) of an olefin-based copolymer and a pigment (C) are contained as essential components.
Comprising also thickeners (D), or
Further, it also contains a film-forming auxiliary (E), and the pigments (C) are dispersed by an aqueous dispersion and / or an aqueous solution (B) of the fluoroolefin copolymer. An object of the present invention is to provide an aqueous resin composition for a paint.

[0010] The aqueous coating resin composition of the present invention comprises
The above-mentioned fluoroolefin-based aqueous resin emulsion (A) is, as a monomer, a monomer in which at least one fluorine atom is directly bonded to a carbon atom forming a polymerizable carbon-carbon double bond. An aqueous resin emulsion in which a so-called fluoroolefin is used as an essential component and further, if necessary, other copolymerizable monomers are copolymerized, and polymerization is initiated in the presence of emulsifiers. It is obtained by usual emulsion polymerization performed using agents.

As the fluoroolefin mentioned here, only typical ones are exemplified, and examples thereof include vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene and chlorotrifluoroethylene.

Among these, preferred are one or more fluoroolefins selected from hexafluoropropylene, chlorotrifluoroethylene and vinylidene fluoride. More preferably, chlorotrifluoroethylene is used from the viewpoint of reaction control during polymerization.

As other copolymerizable monomers, the following compounds can be exemplified. That is, for example, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl 2-ethylhexanoate, vinyl versatate, vinyl laurate, vinyl stearate, vinyl salicylate, monochlor First, various vinyl carboxylate monomers such as vinyl acetate, vinyl cyclohexanecarboxylate, vinyl pt-butylbenzoate, and "Veova" (vinyl ester manufactured by Shell, The Netherlands) Can be raised.

Among these monomers, vinyl pivalate, vinyl caproate, vinyl 2-ethylhexanoate, vinyl versatate (vinyl neononanoate, vinyl neodecanoate), vinyl laurate, vinyl stearate, and cyclohexanecarboxylic acid A vinyl ester of a carboxylic acid having 5 or more carbon atoms and having a linear, branched or cyclic alkyl structure, such as vinyl acid or "Veoba", is also suitable from the viewpoint of enhancing the weather resistance of the final film. It is. More preferably, those having 6 or more carbon atoms are used.

Subsequently, various straight-chains such as methyl-, ethyl-, n-propyl-, isopropyl-, n-butyl-, isoamyl-, n-hexyl-, n-octyl- or 2-ethylhexyl-vinyl ether are used. Alkyl vinyl ethers having a linear or branched alkyl group; cycloalkyl vinyl ethers having various (alkyl-substituted) cyclic alkyl groups such as cyclopentyl vinyl ether, cyclohexyl vinyl ether or methylcyclohexyl vinyl ether; benzyl vinyl ether or phenethyl vinyl ether Various substituted or unsubstituted aralkyl vinyl ethers such as 4-hydroxybutyl vinyl ether; It can be listed vinyl ethers having an alkyl group or an aralkyl group.

Also, various (halogenated) olefins such as vinyl chloride or vinylidene chloride or ethylene, propylene, butene-1, i-butylene, heptene or hexene, or methyl (meth) acrylate, ethyl (Meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth)
Such as acrylate or cyclohexyl (meth) acrylate, C ₁ -C ₈ becomes linear, Toka is having a branched or cyclic alkyl group (meth) alkyl esters of acrylic acid, such as benzyl (meth) acrylate, Various (substituted) aromatic nucleus-containing (meth) acrylic esters can be listed.

Further, styrene, α-methylstyrene,
Various aromatic vinyl compounds, such as styrene and derivatives thereof, such as p-tert-butyl-styrene or p-methylstyrene, and various unsaturated compounds, such as maleic acid, fumaric acid or itaconic acid. Dicarboxylic acids and diesters of monohydric alcohols,

Alternatively, various acid anhydride group-containing monomers such as (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, maleic anhydride or itaconic anhydride; Various carboxyl group-containing monomers or dicarboxylic acids represented by various unsaturated bond-containing hydroxyalkyl ester monocarboxylic acids such as adducts with glycols and the like can be listed.

Among these, the use of crotonic acid or itaconic acid is desirable from the viewpoint of copolymerizability. The main purpose of introducing the acid group-containing monomers is to improve the stability of the aqueous dispersion and to improve the adhesion to the substrate in the final use. It is what it was.

Furthermore, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3
Hydroxyalkyl of various (meth) acrylic acids, such as -hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate or polyethylene glycol mono (meth) acrylate Esters; or various hydroxyl group-containing monomers represented by various unsaturated group-containing polyhydroxyalkyl esters such as dihydroxyalkyl esters of various polycarboxylic acids such as maleic acid or fumaric acid. It can also list monomers.

Further, (meth) acrylamide, N,
Various carboxylic acid amide group-containing monomers represented by N-dimethyl (meth) acrylamide, N-alkoxymethylated (meth) acrylamide, diacetone acrylamide or N-methylol (meth) acrylamide, Various sulfonic acid amide group-containing monomers represented by p-styrenesulfonamide, N-methyl-p-styrenesulfonamide or N, N-dimethyl-p-styrenesulfonamide; Reacts with various N, N-dialkylaminoalkyl (meth) acrylates, such as N-dimethylaminoethyl (meth) acrylate, or various polycarboxylic anhydride-containing monomers, such as maleic anhydride. Represented by an adduct with a compound having an active hydrogen group and a tertiary amino group. That, Toka a variety of tertiary amino group-containing monomers,

Various cyano group-containing monomers represented by (meth) acrylonitrile and the like,
Monomers having a phosphate ester group obtained by a condensation reaction of various hydroxyalkyl esters of α, β-ethylenically unsaturated carboxylic acids, such as hydroxyalkyl acrylate, with phosphate esters. Or various sulfonic acid group-containing monomers such as 2-acrylamido-2-methylpropanesulfonic acid.

In addition, butadiene, hexadiene, octadiene, decadiene, tetradecadiene or 2-
In addition to various di- or trienes represented by methyl-octadiene or decatriene, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate or trimethylolpropane tri (meth) acrylate or divinyl Polymerizable unsaturated bonds in the molecule such as benzene, trivinylbenzene or diallyl phthalate
Or more than one monomer,

Vinyltriethoxysilane, trimethoxysilylvinylether, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane or γ -Various hydrolyzable silyl group-containing monomers, such as (meth) acryloyloxypropylmethyldiethoxysilane, can also be listed.

Of these, one or two selected from hexadiene, octadiene, decadiene, tetradecadiene, 2-methyl-octadiene and decatriene
A mixture of at least one and / or vinyltriethoxysilane, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropylmethyldimethoxysilane, γ- (meth) acryloyloxypropyltriethoxysilane, γ- (Meth) acryloyloxypropylmethyldiethoxysilane or tris (2-methoxyethoxy) vinylsilane,
It is particularly desirable to use various crosslinkable monomers as represented by various hydrolyzable silyl group-containing monomers.

The purpose of introducing such a crosslinkable monomer is to improve the so-called durability such as water resistance, alkali resistance and solvent resistance, or to introduce polymers having a low glass transition point. This is because the film obtained from the polymers has toughness.

These monomers are appropriately selected and used in consideration of the glass transition point of the finally obtained copolymer and the minimum film forming temperature. Preferably, consisting of carboxylic acid vinyl ester monomers, olefins, carboxyl group-containing monomers and crosslinkable monomers,
Any combination.

The above constitutes the fluoroolefin-based aqueous resin emulsion as the component (A) in the present invention.
It is the main ingredient.

In order to prepare the fluoroolefin-based aqueous resin emulsion (A) in the present invention, various monomers as described above are polymerized in an aqueous medium and in the presence of an emulsifier. Radical polymerization may be performed by using agents.

Such emulsifiers are used to stably disperse the above-mentioned various monomers in an aqueous medium and, in the final use mode, to sufficiently exhibit various film properties. Preferably, anionic emulsifiers having no fluorine atom and / or nonionic emulsifiers having no fluorine atom are used. Specific examples include the following.

That is, first, only typical representative examples of anionic emulsifiers containing no fluorine atom (including reactive emulsifiers) are given as examples. Sulfate salt,
Polyoxyethylene alkylphenol sulfate, styrene sulfonate or vinyl sulfate, or various derivatives thereof.

The term "salt" as used herein refers to a salt derived from an alkali metal hydroxide or a salt derived from various volatile bases such as ammonia and triethylamine. Among these, one or a mixture of two or more selected from (substituted) alkyl (benzene) sulfonic acid salts and vinylsulfonic acid salts is preferable.

As nonionic emulsifiers containing no fluorine atom (including reactive emulsifiers), only typical ones are exemplified, and polyoxyethylene alkylphenol ether, polyoxyethylene alkyl ether, polyoxyethylene alkyl ether, Examples include oxyethylene higher fatty acid esters, ethylene oxide-propylene oxide block copolymers, and various derivatives thereof, and these may be used alone or in combination of two or more.

Among these, polyoxyethylene (substituted) alkyl (phenol) ethers are particularly desirable from the viewpoint of physical properties of the finally obtained film. However, it does not prevent the use of a fluorine atom-containing emulsifier such as a perfluorooctanoate.

The use amount of these emulsifiers is suitably in the range of 0.5 to 10% by weight based on the total amount of the monomers, including the anionic and nonionic emulsifiers. Further, in combination with these emulsifiers, water-soluble oligomers composed of polycarboxylic acids or sulfonates, and various water-soluble polymer substances represented by polyvinyl alcohol or hydroxyethyl cellulose, etc. And protective colloids.

The above-mentioned polymerization initiators are not particularly limited as long as they are generally used in emulsion polymerization. If only typical representative examples of the polymerization initiators are given, various water-soluble inorganic peroxides such as hydrogen peroxide; ammonium persulfate, potassium persulfate or sodium persulfate;
Various persulfates; various organic peroxides such as cumene hydroperoxide, benzoyl peroxide or t-butyl hydroperoxide; various azo-based compounds such as azobisisobutyronitrile or azobiscyanovaleric acid Agents and the like, which may be used alone or in combination of two or more.

The amount of the polymerization initiator used is suitably in the range of 0.1 to 2% by weight based on the total amount of the monomers. It is to be noted that a so-called redox polymerization method using such polymerization initiators in combination with metal ions and reducing agents may be used.

As typical examples of such reducing agents, only typical ones are exemplified by sodium bisulfite, sodium metabisulfite, sodium bithiosulfate, sodium hydrosulfate, sodium formaldehyde sulfoxylate, reducing sugar and the like. In addition, if only typical representative examples of the above-mentioned metal ions are given, copper sulfate, secondary chloride
Iron, ferric sulfate or silver nitrate. Furthermore, various known and commonly used chain transfer agents can also be used.

The fluoroolefin-based aqueous resin emulsion (A) is prepared by first mixing a monomer mixture as it is or in an emulsified state in an aqueous medium, preferably in the presence of ion-exchanged water and an emulsifier. Therefore,
Or divided or continuously, dropped into the reaction vessel, in the presence of the above-mentioned polymerization initiators, about 1 kg / c
With a gauge pressure of m ^{2 to} 100 kg / cm ² , about 50 ° C. to 1
The polymerization may be performed at a reaction temperature of 50 ° C. In some cases, the polymerization may be carried out under a higher pressure or under a lower temperature condition.

The amount of the fluoroolefin monomer contained in the total monomer (total amount of monomers) is generally as follows:
It is necessary to be at least 30% by weight. If it is less than this, it will be unsatisfactory in terms of the durability of the finally obtained coating film.

The ratio of the total monomer amount to water is as follows:
The final solids content should be set within the range of 1 to 60% by weight, preferably 15 to 55% by weight. In carrying out the emulsion polymerization, in order to grow or control the particle size, the polymerization may be carried out in advance with the emulsion particles being present in the aqueous phase.

As the water in the aqueous medium used here, ion-exchanged water is basically used, and the amount of the water used is such that it becomes 70% by weight or more in the aqueous medium. Here, an organic solvent may be used in combination in the remaining portion of less than 30% by weight.

In the polymerization reaction, when the pH in the system is approximately 1.0
It may be advanced within the range of 7.0 to 7.0. Adjustment of pH at that time, such as disodium phosphate and borax,
Alternatively, it may be performed using so-called pH buffers such as sodium hydrogen carbonate and ammonia. More p
Although it is possible to manufacture under H conditions, it is understood that under special usage conditions, when a coating film is formed, it may end up giving performance lacking in water resistance, alkali resistance, etc. Should be.

The fluoroolefin-based aqueous resin emulsion (A) thus obtained is subsequently
An operation for removing unreacted gaseous monomers remaining in the emulsion particles may be performed.

The fluoroolefin-based aqueous resin emulsion (A) thus obtained generally has a number average molecular weight of 5,000 to 1,000,000 when converted to a state having no crosslinkable monomers. It is appropriate that the weight average molecular weight is in the range of 10,000 to 3,000,000 and the minimum film formation temperature is in the range of about −30 ° C. to 60 ° C. In addition, the particle diameter is generally in the range of 0.02 to 0.1.
A range of 5 microns (μm) is appropriate.

Next, the above-mentioned aqueous dispersion and / or aqueous solution (B) of the fluoroolefin-based copolymer means that the fluoroolefin-based copolymer itself is dissolved in water without using emulsifiers or the like. It refers to those that are stably dispersed or completely water-soluble.

In the following, two or three examples of the method for preparing the aqueous dispersion and / or aqueous solution (B) of the fluoroolefin-based copolymer will be described. First, (1) in water, Fluoroolefin as an essential component,
When copolymerizing monomers having various acidic groups such as carboxyl groups that can be copolymerized with this, some or all of the acidic groups incorporated by copolymerization in the copolymer Is polymerized while adding and neutralizing a basic compound.

Here, an aqueous dispersion is obtained, or
Whether it becomes water-soluble depends on the concentration of so-called acidic groups such as carboxyl groups in the copolymer and the degree of neutralization (degree of neutralization) by the basic compound. For example, when the acidic group is a carboxyl group, the carboxyl group concentration generally exceeds 6% of all monomers, and
When the degree of neutralization is gradually increased, the fluoroolefin-based copolymer gradually changes from a state of being dispersed in water to a water-soluble one.

(2) In an organic solvent, a fluoroolefin is an essential component, and a monomer having an acidic group such as a carboxyl group, which is copolymerizable therewith, is copolymerized.
A method of preparing an organic solvent solution of a fluoroolefin-based copolymer, and then, in the same manner as in (1), neutralize acidic groups in the copolymer with a basic compound,
Thereafter, when the organic solvents in the system are removed while adding water under forced stirring, an aqueous dispersion of a fluoroolefin-based copolymer is obtained.

(3) A modification of the above method (2), except that anionic or cationic dissociation, which can be copolymerized with a fluoroolefin, is performed instead of using an acidic group-containing monomer. Copolymerizing a monomer having a group and / or a monomer having a nonionic hydrophilic group,
Next, if necessary, after neutralization, the solvent is removed with addition of water under forced stirring to prepare an aqueous dispersion of a fluoroolefin-based copolymer.

As the monomers and the basic compound used here, various substances as described above can be used. As the anionic or cationic monomer having a dissociating group and / or the nonionic hydrophilic group-containing monomer, a polymerizable unsaturated double bond is added to various emulsifiers as described above. So-called reactive emulsifiers in bound form are particularly representative.

The above is a typical method for preparing the component (B). The fluoroolefin copolymer itself can be stably dispersed in water in the absence of emulsifiers. As long as it has been (chemically) converted or completely solubilized, it can be used without any problem even if it is other than the above examples.

Next, the third component of the present invention,
If only typical examples of the above-mentioned pigments (C) are exemplified, titanium oxide, mica, talc, clay, precipitated barium sulfate, silica powder, calcium carbonate,
Various inorganic pigments such as iron oxide, zinc oxide, aluminum powder or carbon black; various organic pigments such as azo, phthalocyanine or quinacridone; and various plastic pigments. It is appropriately selected and used according to each final purpose. As these pigments (C), those dispersed in advance with the above-mentioned component (B) are used.

The components (A) and (A)
The mixing ratio of the component (B) and the component (C) is a solid content ratio, and is generally about 100 parts by weight of the component (A).
(B) In the range where the component is 2 to 100 parts by weight,
It is appropriate that the content of the component (C) is 0.5 to 200 parts by weight.

The water-based paint resin composition of the present invention may further comprise, if necessary, a thickener (D) or, in addition to the thickener (D), Film-forming auxiliaries (E) can also be blended.

As the thickeners (D) used in this case, only typical ones are exemplified, and various cellulose-based thickeners represented by hydroxyethylcellulose or carboxymethylcellulose are exemplified. , Urethane-based thickeners or polycarboxylic acid-based thickeners. Among these, polycarboxylic acid-based thickeners are particularly desirable from the viewpoint of stability when blended with the fluoroolefin-based aqueous resin emulsion used in the present invention.

That is, speaking of the system in which the thickener (D) is used, the fluoroolefin-based aqueous resin emulsion (A) and the fluoroolefin-based aqueous resin emulsion (A) described above are used. And an aqueous dispersion and / or aqueous solution (B) of a fluoroolefin-based copolymer, and an aqueous dispersion and / or aqueous solution (B) of a fluoroolefin-based aqueous resin emulsion (A) and a fluoroolefin-based copolymer. The compounding system with the pigment (C) is a target, and from the viewpoint of stability in any case, the use of a polycarboxylic acid-based thickener is particularly desirable.

On the other hand, if only typical representative examples of the film-forming aids (E) are given as examples, ester-based,
In addition to various commercially available organic solvents such as ketones, aromatics and aliphatics, ester- or ether derivatives of ethylene glycol, respectively; ester- or ethers of diethylene glycol, respectively In addition to the system derivatives, various plasticizers such as "Texanol" (a product of Eastman Chemical Co., USA) commonly used for water-based paints can also be used. Can be done.

In addition to these, various additives necessary for forming a coating material, such as dispersants, wetting agents,
Thixants, UV absorbers, antioxidants, water repellents, antifreezes, preservatives / detergents or defoamers also take into account the performance of the resulting coatings. In addition, they can be appropriately selected and used.

Thus, the resin composition for a water-based paint of the present invention is obtained. The method for applying or coating the resin composition for a water-based paint on various substrates is as follows.
Although not particularly limited, brush coating, roller coating, spray coating, roll coater coating, or showering coating may be mentioned as examples, and such a method is particularly preferable.

In this case, especially for construction site construction, it is desirable to use a paint having a minimum film-forming temperature of 0 ° C. or less with the film-forming aid (E) added. It is desirable to use a method such as brush coating, roller coating or spray coating.

For so-called factory line coating on roof materials such as tiles and wall materials, etc., according to the commonly used heating and forced drying method, film-forming auxiliaries (E) are used in accordance with the drying conditions. It is desirable to select and use a paint having a minimum film-forming temperature of about 60 ° C. or less, preferably 50 ° C. or less, with the addition of ()). The coating method includes roll coater coating, roller coating, and spray coating. Alternatively, it is desirable to use a method such as a flow coater coating or a dip coating such as dipping, including showering coating.

Regardless of whether it is for on-site construction or for factory line painting or heating and forced drying line painting, the coating is performed after the coating in order to perform the coating in an atmosphere at a temperature of 60 ° C. or more, substantially 200 ° C. or less. ,If necessary,
After setting time, by heating and drying,
In order to further enhance the film forming property or film forming property and ensure long-term durability of the coating film, furthermore, the blocking is reduced as much as possible, and the contamination resistance is also secured. It is also desirable to do.

Further, the resin composition for water-based paint as described above may be applied directly on the base material in one coat or in multiple coats. An acrylic-styrene copolymer system, an acrylic-urethane combination system, a silicon-acryl combination system, an epoxy system, a urethane system or a silicon system, etc., which are generally undercoated with a coating material containing a binder having good alkali resistance. Alternatively, the resin composition for water-based paint as described above may be applied as a top coat to improve and improve the weather resistance of the entire coating system.

In any of the above coating systems, the dry film thickness of the resin composition for water-based paint of the present invention is suitably 5 μm or more. When the thickness is less than 5 μm, the long-term durability of the film tends to be insufficient.

According to the present invention, a coating excellent in pigment dispersibility and, as a result, a coating having high gloss can be obtained.

In the present invention, as the base material, for example, cement mortar, cement concrete, ALC
(Lightweight concrete), asbestos concrete, hardened concrete skeleton prepared by hydrating and crystallizing an alkaline substance, such as wood cement board or calcium silicate board, mainly for wall materials or roof materials Such materials are particularly typical. In addition to these substrates, metals, plastics,
It can also be applied to woods, glasses, papers, fibers and the like.

The water-based paint resin composition obtained according to the present invention can be used as an exterior or interior water-based paint composition because it can form a film having high gloss. It can also be used as a coating agent for woods, inorganic substrates, papers, fibers, and the like, or as a treating agent.

[0069]

EXAMPLES Next, the present invention will be described more specifically with reference examples, examples and comparative examples. In addition,
In the following, all parts and percentages are by weight unless otherwise specified.

Reference Example 1 [Preparation Example of Fluoroolefin-Based Aqueous Resin Emulsion (A)] A 2-liter stainless steel pressure-resistant reaction vessel (autoclave) equipped with a stirrer, a nitrogen inlet tube, a thermometer and a temperature controller. The inside is sufficiently replaced with nitrogen gas,
800 g of ion-exchanged water, 20 g of sodium dodecylbenzenesulfonate, 20 g of polyoxyethylene nonylphenyl ether, and 10 g of borax (borax) as a pH buffer were charged and dissolved.

Next, 200 g of vinyl acetate and 10 g of hexadiene were added, and 280 g of vinyl neononanoate, 10 g of crotonic acid, and 500 g of chlorotrifluoroethylene collected by liquefaction were also added.

Thereafter, ethylene gas was supplied at 15 kg /
Press-fit until cm ² . The internal temperature of the autoclave,
The temperature was raised to 80 ° C. At this time, ethylene gas was adjusted so that the pressure in the system during the reaction was approximately 30 kg / cm ² .

Next, at the same temperature, an aqueous catalyst solution obtained by dissolving 5 g of potassium persulfate in 200 g of ion-exchanged water was injected into the reaction vessel over 3 hours. After the addition of the catalyst aqueous solution, the polymerization reaction was allowed to proceed at the same temperature for 10 hours to obtain a desired fluoroolefin-based aqueous resin emulsion.

The pH during the reaction proceeded at 3.5. During the reaction, the pressure in the system decreases as the monomers are consumed. In each case, the pressure of the reaction system is maintained at 30 kg / cm ² by introducing ethylene.

After completion of the reaction, the reaction mixture is cooled to room temperature,
14% aqueous ammonia was added until the pH became approximately 7.5, and a silicon-based defoaming agent was also added, followed by thorough stirring.

Next, the pressure in the system was returned to normal pressure, and the unreacted gas dissolved in the dispersion was distilled off under reduced pressure. The dispersion thus obtained has a nonvolatile content of 52.0%, a pH of 7.2, a minimum film-forming temperature of 38 ° C., and an average particle size of 0.08 μm.
It was a white fluoroolefin-based aqueous resin emulsion. Hereinafter, this is abbreviated as (A-1).

This (A-1) had a fluoroolefin content of about 47% by weight as determined by elemental analysis, ion chromatography, infrared absorption spectrum and compositional analysis by pyrolysis gas chromatography.

Reference Example 2 (same as above) A desired fluoroolefin-based aqueous resin emulsion was obtained in the same manner as in Reference Example 1, except that hexafluoropropylene was used instead of chlorotrifluoroethylene. The resulting dispersion has a non-volatile content of 50.0%, a pH of 7.0, and a minimum film forming temperature of 28.
It was a white fluoroolefin-based aqueous resin emulsion having an average particle diameter of 1.1 µm at ℃.
Hereinafter, this is abbreviated as (A-2).

This (A-2) had a fluoroolefin content of about 50% by weight as determined by elemental analysis, ion chromatography analysis, infrared absorption spectrum and compositional analysis by pyrolysis gas chromatography.

REFERENCE EXAMPLE 3 (Preparation Example of Fluoroolefin Aqueous Resin Emulsion for Measuring Molecular Weight) Crosslinking agent was prepared in the same manner as in Reference Example 1, except that the use of hexadiene was changed to be completely omitted. To obtain a dispersion free of the class. Hereinafter, this is abbreviated as (R-1). This (R-1) was taken out by precipitating only the polymer component by adding sodium chloride according to a conventional method.

Next, free emulsifiers were extracted with ion-exchanged water, dried, and dissolved in tetrahydrofuran. The molecular weight in terms of polystyrene of the obtained sample was measured by gel filtration chromatography. The results obtained here show that the number average molecular weight is 167,0.
00 and a weight average molecular weight of 498,000. This corresponds to the molecular weight of (A-1) obtained in Reference Example 1 excluding the amount of the crosslinking agent.

Reference Example 4 [Example of preparing aqueous dispersion (B) of fluoroolefin copolymer and example of dispersing pigment using the same] A stirrer, a nitrogen inlet tube, a thermometer and a temperature controller were used. The inside of a 2-liter stainless steel pressure-resistant reaction vessel (autoclave) provided was sufficiently replaced with nitrogen gas, and 800 g of methyl ethyl ketone was charged. Then, 160 g of ethyl vinyl ether, 50 g of hydroxybutyl vinyl ether, and 280 g of vinyl neononanoate Also, 500 g of the liquefied and collected chlorotrifluoroethylene was charged, and the internal temperature of the autoclave was raised to 60 ° C.

Then, at the same temperature, an aqueous catalyst solution obtained by dissolving 5 g of azobiscyanovaleric acid in 200 g of methyl ethyl ketone was pressed into the reaction vessel over 3 hours. After the addition of the aqueous catalyst solution, the polymerization reaction was allowed to proceed at the same temperature for 10 hours to obtain a target organic solvent solution of the fluoroolefin copolymer.

After the completion of the reaction, the internal pressure of the autoclave was returned to normal pressure, and 120 g of maleic anhydride was added to add to the hydroxyl groups in the copolymer.

Thereafter, triethylamine in the same amount as the added maleic anhydride was added and mixed well, and then methyl ethyl ketone in the system was distilled off while adding ion-exchanged water. The aqueous solution of the fluoroolefin-based copolymer obtained here was a slightly milky white aqueous solution having a nonvolatile content of 52.0%.

Next, 128 g of the aqueous solution of the fluoroolefin-based copolymer and 100 g of titanium oxide were mixed and kneaded using a sand mill. The concentration of titanium oxide in the pigment dispersion thus obtained was 60% by weight, and the nonvolatile content was 73%. Hereinafter, this is referred to as (B-1).

Examples 1 and 2 and Comparative Examples 1 and 2 Each of (A-1) and (A-2) obtained in Reference Examples 1 and 2 was diluted so that the nonvolatile content was 45%. And (B-1) obtained in Reference Example 4 and "Boncoat 3750" which is a polycarboxylic acid-based polymer thickener as a thickener [Dai Nippon Ink Chemical Industry Co., Ltd.]
And 5% dilute aqueous solution of "Texanol" (a film-forming aid manufactured by Eastman Chemical Co., USA) as a film-forming aid were also added at a blending ratio as described in Table 1. Thus, a desired aqueous resin composition for water-based paint was obtained.

Next, each of the compositions thus obtained was applied on a slate plate using a No. 60 bar coater, and dried at 60 ° C. for 20 minutes. After that, it was subjected to various tests by leaving it to dry at room temperature for 7 days.

The test results are shown in the same table.

As a comparative example, reference example 1 was also used.
And (A-1) and (A
The aqueous dispersion (C-1) of titanium oxide, thickeners, and film-forming auxiliaries obtained by a conventional method in the 45% dispersion of -2) are described in Table 1. By adding in such a mixing ratio, a resin composition for a water-based paint for control was obtained.

After that, in the same manner as in Examples 1 and 2,
It was subjected to various tests by painting and drying. The test results are shown in the same table. In addition, the titanium oxide dispersion (C-1) described above includes 70 parts of titanium oxide and Discoat N-1 which is a pigment dispersant.
1 (1 part of styrene-maleic acid-based water-soluble resin manufactured by Daiichi Kogyo Seiyaku Co., Ltd., nonvolatile content 30%) (5 parts in terms of solid content) and 13.3 parts of ion-exchanged water were mixed, Next, using a disperser (product of Tokushu Kika Co., Ltd.) as a forced stirrer, the mixture was mixed and dispersed at 6,000 rpm for 30 minutes. The obtained aqueous dispersion (C-1) had a titanium oxide concentration of 70% by weight and a nonvolatile content of 75%.

[0092]

[Table 1]

<< Footnotes to Table 1 >> The titanium oxide dispersions of Examples 2 and Comparative Examples 1 and 2 were prepared so that the pigment volume concentration (PVC) was 15% by volume. In the case of Comparative Example 2, PVC was blended so as to be 10% by volume.

The specific gravity of the solid content of the fluoroolefin-based copolymer was 1.5, and the specific gravity of the titanium oxide was 4.2.

As the thickeners, “Boncoat 375” is used.
(A-1) or (A-2)
Was added at a rate of 5%. After addition of the thickeners, the pH of the system was adjusted to 8 with 14% aqueous ammonia to adjust the viscosity of the system.

Examples of the film-forming auxiliary include “Texanol”
Was blended at a ratio of 2% with respect to (A-1) or (A-2).

The gloss value was calculated using a Murakami gloss meter.
Degree gross value (that is, indicated by 60 degree specular reflectance).

The accelerated weather resistance was determined by visually observing the appearance of each coating film after performing exposure (accelerated weather test) for 5,000 hours using a Dupanel light control weather meter. It is.

The evaluation criteria for the accelerated weather resistance are as follows:
Then: ◎ …… No external appearance defects △ …… Finishing is observed in the paint film × …… Film blistering, peeling or whitening is observed in the paint film

As described above, the film (coating film) obtained by using the resin composition for a water-based paint of the present invention, which is mainly composed of a fluoroolefin-based water-based resin emulsion, was completely free from any test. It will be appreciated that it has satisfactory performance.

[0101]

As described above, the resin composition for water-based paint according to the present invention is superior to the composition obtained according to the prior art, especially in the pigment dispersibility and the like. It can form a high gloss coating.

Claims (4)

(57) [Claims] 1. A fluoroolefin aqueous resin emulsion (A) obtained by emulsion polymerization in the presence of emulsifiers.
When, an aqueous dispersion of dispersion and / or water-soluble been fluoroolefin copolymer without the use of emulsifiers and / or an aqueous solution (B), pigments and (C) containing as essential components And the pigments (C) are
Aqueous dispersion of polyolefin copolymer and / or water
An aqueous resin composition for coatings, characterized by being dispersed by a solution (B) . 2. A fluoroolefin-based aqueous resin emulsion (A) obtained by emulsion polymerization in the presence of emulsifiers.
And an aqueous dispersion and / or aqueous solution (B) of a fluoroolefin-based copolymer dispersed and / or solubilized without using emulsifiers, a pigment (C), and a thickener (D ) , Wherein the pigments (C) are
Aqueous dispersion of an oloolefin copolymer and / or
Characterized by being dispersed by the aqueous solution (B) ,
Aqueous resin composition for paint. 3. A fluoroolefin aqueous resin emulsion (A) obtained by emulsion polymerization in the presence of emulsifiers.
And an aqueous dispersion and / or aqueous solution (B) of a fluoroolefin-based copolymer dispersed and / or solubilized without using emulsifiers, a pigment (C), and a thickener (D ) and will contain a film-forming aids the (E), said pigment
Material (C) is an aqueous component of the fluoroolefin-based copolymer.
An aqueous resin composition for a coating, characterized by being dispersed by a powder and / or an aqueous solution (B) . 4. An article coated with the aqueous resin composition for a paint according to claim 1.