JP3365366B2 - Crosslinkable fluororesin aqueous dispersion composition - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crosslinkable fluororesin aqueous dispersion composition that can be used in an aqueous paint useful for interior and exterior construction.

[0002]

2. Description of the Related Art Conventionally, a cross-linkable aqueous fluororesin coating material has been proposed for reducing the amount of solvent or for applications requiring durability. As such a cross-linkable aqueous fluororesin coating, an aqueous dispersion consisting of a carboxyl group and a polyvalent metal salt, an aqueous dispersion consisting of a hydroxyl group and a water-dispersible isocyanate, an aqueous dispersion consisting of a keto group and a hydrazine derivative are proposed. However, in any of the crosslinkable aqueous fluorine-containing resin dispersions, the coating film obtained by drying at room temperature did not have practically sufficient hardness.

[0003]

In view of the above points, the present invention provides an aqueous dispersion of a fluororesin having a carboxyl group and / or a sulfonic acid group with an aziridine group, a carbodiimide group or an oxazoline group. By combining with a crosslinking agent having, the purpose is to obtain a room temperature crosslinkable fluorine-containing resin aqueous dispersion composition useful as a coating binder that can form a coating film having practically sufficient hardness when dried at room temperature. To do.

[0004]

SUMMARY OF THE INVENTION The present invention is a fluoroolease.
In the presence of fin polymer particles, carboxyl groups and
Having a sulfonic acid group and having an α, β-unsaturated group
An aqueous dispersion of a fluorine-containing resin having a fluorine content of 10% by weight or more and having a carboxyl group and / or a sulfonic acid group, and an aziridine group, a carbodiimide group or A crosslinkable fluororesin aqueous dispersion composition comprising a crosslinking agent having an oxazoline group (provided that the fluororesin is a crosslinkable resin).
Carboxyl group and / or sulfonic acid group as functional group
It is a fluorine-containing resin having only) .

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The aqueous dispersion composition of the present invention comprises an aqueous dispersion of a fluorine-containing resin having a carboxyl group and / or a sulfonic acid group and a crosslinking agent having an aziridine group, a carbodiimide group or an oxazoline group. . Hereinafter, each component will be described.

As the fluorine-containing polymer having a carboxyl group and / or a sulfonic acid group, a fluoroolefin is used as an essential component, and an organic acid having a carboxyl group and / or a sulfonic acid group is copolymerized and polymerized with the fluoroolefin. In the presence of the resulting modified polymer (A) or fluoroolefin polymer particles, a non-fluorine-based monomer having a carboxyl group and / or a sulfonic acid group and an α, β-unsaturated group is seeded. Examples of the fluorine-containing seed polymer (B) obtained by polymerization include fluorine-containing seed polymers (B) in the present invention.
A system seed polymer (B) is used .

In both the polymers (A) and (B), the fluoroolefin (a) used is, for example, vinyl fluoride or vinylidene fluoride (Vd).
F), tetrafluoroethylene (TFE), chlorotrifluoroethylene (CTFE), hexafluoropropylene (HFP), trifluoroethylene, etc., having 2 carbon atoms
One or more fluoroolefins of about 4 to 4 are preferably used.

As the preferred combination of the fluoroolefin (a), for example, VdF, TFE, CTFE, etc. may be used alone, or VdF / TFE system, VdF / HFP may be used.
System, VdF / CTFE system, VdF / TFE / CTFE
System, VdF / TFE / HFP system, TFE / HFP system and the like.

In addition to the fluoroolefin, a non-fluorine-based monomer copolymerizable with the fluoro-olefin (provided that the carboxyl group- and / or sulfonic acid group-containing non-fluorine-containing α, β-unsaturated group described below is used as a unit (Excluding body (d))
You may use together (a) as a copolymerization component.

[0010] Examples of the fluoroolefin copolymerizable with non-fluorine-containing monomer (b), such as ethylene, propylene, alpha-olefins such as isobutylene; ethyl vinyl ether (EVE), cyclohexyl vinyl ether (CHVE), blanking Chill Vinyl ethers such as vinyl ether, isobutyl vinyl ether, methyl vinyl ether and polyoxyethylene vinyl ether; polyoxyethylene allyl ether, ethyl allyl ether ,
A Lil alcohols, alkenyl such as allyl ether, vinyl acetate, lactate, vinyl butyrate, vinyl pivalate, vinyl benzoate, VeoVa9, VEOVA1
Examples thereof include vinyl esters such as 0 (product name of Shell Chemical Co.). In particular, α-olefins, vinyl ethers, vinyl esters and alkenyls are preferably used.

Examples of the copolymerization system include TFE / propylene system, TFE / ethylene system, TFE / vinyl ester system, TFE / vinyl ether system, HFP / vinyl ether system, HFP / vinyl ester system, CTFE / vinyl ether system and the like. can give.

In the copolymerization system of the fluoroolefin and the non-fluorine type monomer, it is preferable that the fluoroolefin monomer unit is contained in an amount of 20 to 80 mol%.
If the fluoroolefin monomer unit is less than 20 mol%, the weather resistance is not sufficiently exhibited, and if it exceeds 80 mol%, the appearance tends to be deteriorated when it is formed into a coating film to form a coating film.

A monomer for introducing a carboxyl group and / or a sulfonic acid group by copolymerization with the above-mentioned fluoroolefin (a) (or a mixture of the fluoroolefin (a) and the non-fluorine-containing monomer (a)). As the monomer (c), examples of the monomer for introducing a carboxyl group include non-fluorine unsaturated acids such as maleic acid, itaconic acid and crotonic acid; and fluorine-containing unsaturated acids such as perfluorobutenoic acid. Examples of the sulfonic acid group-introducing monomer include 2-acrylamido-2 methylpropane sulfonic acid.

The monomer (c) having a carboxyl group and / or a sulfonic acid group is to introduce a crosslinking point with a crosslinking agent having an aziridine group, a carbodiimide group or an oxazoline group described later into the polymer, After cross-linking,
It gives a coating film having excellent initial water resistance and practically sufficient hardness when dried at room temperature.

The total amount of carboxyl groups or sulfonic acid groups is 0.1 to 10% by weight in the modified polymer (A),
It is preferably 0.5 to 5.0% by weight. If it is too small, the number of cross-linking points will be small and sufficient hardness will not be obtained, and if it is too large, the viscosity will be too high and the handling properties such as coatability will be hindered, and the flexibility will be poor and the coating film will be easily cracked. Occurs.

Modified fluoroolefin polymer (A)
The aqueous dispersion of particles of 1 is produced by a conventional emulsion polymerization. That is, it can be obtained by emulsion-polymerizing the above-mentioned fluoroolefin monomer or monomer mixture in the presence of an emulsifier in an amount of 5% by weight or less, preferably 1% by weight or less, relative to water.

The water used in this case is preferably deionized water. Further, the emulsifier is preferably a fluorine-based surfactant. Furthermore, a reactive fluorine-based emulsifier can also be used. Further, a trace amount of a non-fluorine-based nonionic emulsifier can be used together.

The fluorinated emulsifier is one or a mixture of two or more compounds having a fluorine atom in the structure and having surface activity. For example, an acid represented by X (CF ₂ ) _n COOH (n is an integer of 6 to 20, X is F or H), a metal salt, an ammonium salt, an amine salt or a quaternary ammonium salt; Y (CH ₂ CF ₂ ) _m COOH (m is an integer of 6 to 13, Y is F, acid represented by Cl), its metal salts, ammonium salts, and amine salts or quaternary ammonium salt. Further, the reactive emulsifiers exemplified in JP-A-8-67795 can be used alone or in combination with the fluorine-based emulsifiers. In addition, JP-A-7-9
The non-fluorinated nonionic emulsifier described in JP-A No. 0153 can also be used in combination.

The fluorine content in the modified fluoropolymer (A) is 10% by weight or more, preferably 30% by weight or more. If the fluorine content decreases, the weather resistance will not be sufficiently exhibited.

The aqueous dispersion of the fluorine-containing seed polymer (B), which is another form of the fluorine-containing resin aqueous dispersion of the present invention, is prepared in the presence of seed particles of the fluorine-containing polymer (b-1). Further, it is obtained by seed polymerization of a non-fluorine-containing monomer (d) having a carboxyl group and / or a sulfonic acid group and a reactive α, β-unsaturated group in an aqueous medium.

Fluorine-containing polymer (b-1) used as seed particles
Is one or two of the above-mentioned fluoroolefins (a)
A fluorine-containing polymer obtained by polymerizing one or more kinds, or a fluorine-containing copolymer obtained by copolymerizing the fluoroolefin (a) and the non-fluorine-containing monomer (a) can be preferably used. The types and combinations of the preferred monomers are the same as described above.

The monomer (c) having a carboxyl group and / or a sulfone group is for introducing a cross-linking point with a cross-linking agent having an aziridine group, a carbodiimide group or an oxazoline group described later into the seed polymer, After crosslinking, it gives a coating film having excellent initial water resistance and practically sufficient hardness when dried at room temperature.

Examples of the non-fluorine-containing α, β-unsaturated monomer (d) containing a carboxyl group include acrylic acid, methacrylic acid, itaconic acid, succinic acid, succinic anhydride, fumaric acid, fumaric anhydride and crotonic acid. Α, β-unsaturated carboxylic acids such as maleic acid and maleic anhydride. Of these, acrylic acid and methacrylic acid are preferable from the viewpoint of copolymerization reactivity. Non-fluorinated α containing sulfone group
Examples of β-unsaturated monomers include 2-acrylamido-2 methylpropane sulfonic acid. These monomers (d) can be used alone or in combination of two or more.

The non-fluorine-containing monomer for seed polymerization contains 80 mol% or less, preferably 20 to 50 mol%, of a non-fluorine-containing monomer (e) other than the monomer (d). Is preferred.

As the other non-fluorine-containing monomer (e) for seed polymerization, an alkyl acrylate having an alkyl group having 1 to 18 carbon atoms or an alkyl group having 1 to 1 carbon atoms is used.
8 Reactivity α, β such as methacrylic acid alkyl ester
-Unsaturated monomers, monomers having an ethylenically unsaturated unit copolymerizable therewith, and the like.

Examples of the alkyl acrylate having an alkyl group having 1 to 18 carbon atoms include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, 2-acrylic acid acrylate.
Examples thereof include ethylhexyl and lauryl acrylate.

Examples of the methacrylic acid alkyl ester whose alkyl group has 1 to 18 carbon atoms include, for example, methyl methacrylate, ethyl methacrylate, propyl methacrylate,
N-propyl methacrylate, isobutyl methacrylate,
Examples thereof include cyclohexyl methacrylate and lauryl methacrylate.

Further, for the purpose of improving solvent resistance and water resistance, a polyfunctional monomer such as ethylene glycol dimethacrylate or propylene glycol dimethacrylate may be copolymerized.

Examples of the monomer having an ethylenically unsaturated unit copolymerizable with an acrylic ester and / or a methacrylic ester include α-olefins such as ethylene, propylene and isobutylene; ethyl vinyl ether (EVE) and cyclohexyl vinyl ether. (CHVE), blanking chill vinyl ether, isobutyl vinyl ether, methyl vinyl ether, such as polyoxyethylene ethers; polyoxyethylene allyl ether, ethyl allyl ether, a Li <br/> alcohol, alkenyl such as allyl ether; acetic acid Vinyl, vinyl lactate, vinyl butyrate, vinyl pivalate, vinyl benzoate, VEOVA9, VEOVA10
Vinyl esters such as (Shell Co. product name); styrene, alpha-methyl styrene, can be mentioned etc. aromatic vinyl compounds such as p-tert-butylstyrene.

The unit of the monomer (d) containing a carboxyl group and / or a sulfonic acid group is 0.1 to 10% by weight, particularly 0.1% by weight in the resulting fluorine-containing seed polymer (B).
It is preferably contained in an amount of 5 to 5.0% by weight. Monomer (d)
When the content of the unit is small, the effect of improving the initial water resistance of the obtained coating film becomes small, and the hardness does not increase to a practically sufficient hardness. Further, when the amount is large, the viscosity of the aqueous dispersion becomes remarkably large, and the handling property is hindered, and the practicality as a paint is impaired.

The fluorine content in this seed polymer (B) was 1
It is 0% by weight or more, preferably 30% by weight or more. If the fluorine content decreases, the weather resistance will not be sufficiently exhibited. Further, in the seed polymer (B), the fluoroolefin monomer unit preferably accounts for 20 to 90 mol% with respect to the entire seed polymer. If the fluoroolefin monomer unit is less than 20 mol%, the weather resistance will not be sufficiently exhibited, and if it exceeds 90 mol%, the appearance tends to be deteriorated when it is made into a paint to form a coating film.

The seed polymerization of the fluorine-containing seed polymer (b-1) particles of the non-fluorine-containing monomers (d) and (e) can be carried out under the same conditions as in ordinary emulsion polymerization. For example,
A surfactant, a polymerization initiator, a chain transfer agent, and in some cases a chelating agent, a pH adjusting agent and a solvent are added to an aqueous medium containing the particles of the fluorinated polymer (b-1), and the temperature is adjusted to 20 The reaction is performed at about 90 ° C for about 0.5 to 6 hours.

When the non-fluorine-containing monomer is emulsion polymerized in the presence of the fluorine-containing polymer seed particles, swelling of the monomer into the fluorine-containing polymer seed particles occurs first, and at this point, the monomer is swelled. It is considered that the aqueous dispersion of the fluorine-containing polymer particles uniformly dissolved in the solution becomes a state, and the non-fluorine-containing monomer is polymerized by the addition of the initiator to form the compatibilized particles in which the molecular chains are entangled with each other. .

As the surfactant, anionic, nonionic or anionic-nonionic combinations are used, and in some cases amphoteric surfactants can also be used.

As the anionic surfactant, higher alcohol sulfuric acid ester, alkyl sulfonic acid sodium salt, alkylbenzene sulfonic acid sodium salt, succinic acid dialkyl ester sulfonic acid sodium salt, alkyl diphenyl ether disulfonic acid sodium salt and the like are used. Nonionic surfactants such as polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene alkylphenyl esters, sorbitan alkyl esters, glycerin esters or their derivatives Is exemplified.

Examples of the amphoteric surfactant include lauryl betaine. It is also possible to use a so-called reactive emulsifier that is copolymerizable with the ethylenically unsaturated monomer.

Commercially available reactive emulsifiers are Bremmer PE-350 and Bremmer PME-40.
0, Bremmer 70PEP350B (NOF CORPORATION)
Manufactured), NK ester M-40G, NK ester M-90.
G, NK ester M-230G (Shin Nakamura Chemical Co., Ltd.)
RMA450M (manufactured by Nippon Emulsifier Co., Ltd.), AQUARON HS10, AQUARON HS20, AQUARON HS1
025, Aqualon RN10, Aqualon RN20, Aqualon RN30, Aqualon RN50, Aqualon R
N2025 (Daiichi Kogyo Seiyaku Co., Ltd.), NK ester A
MP-60G, NK ester CB-1, NK ester S
A, NK ester A-SA, Eleminol JS2, Eleminol RS30 (manufactured by Sanyo Chemical Industry Co., Ltd.), Latemur WX (manufactured by Kao Corp.) and the like are exemplified.

The amount of the surfactant used is usually 0.0 per 100 parts by weight of the non-fluorine-based unsaturated monomer (d) and (e).
It is about 5 to 5.0 parts by weight.

The polymerization initiator is not particularly limited as long as it generates a radical that can be subjected to a free radical reaction in an aqueous medium between 20 and 90 ° C., and depending on the case,
It is also possible to use it in combination with a reducing agent. Examples of the water-soluble initiator include persulfate, hydrogen peroxide, 2,
2-Azobis (2-amidinopropane) hydrochloride (AIB
A); Examples of the reducing agent include sodium pyrobisulfite, sodium hydrogen sulfite, and sodium L-ascorbate. Examples of the oil-soluble initiator include diisopropyl peroxydicarbonate (IPP), benzoyl peroxide, dibutyl peroxide, azobisisobutyronitrile (AIBN) and the like. The amount of the initiator used is usually a non-fluorine-based unsaturated monomer (d) and (e) 100.
It is about 0.05 to 2.0 parts by weight per part by weight. The polymerization temperature is preferably in the range of 20 to 90 ° C.

As the chain transfer agent, halogenated hydrocarbons (eg chloroform, carbon tetrachloride etc.), mercaptans (eg n-lauryl mercaptan, t-lauryl mercaptan, n-octyl mercaptan) etc. are used. The amount of the chain transfer agent used is usually about 0 to 5.0 parts by weight per 100 parts by weight of the non-fluorine-based unsaturated monomer.

As a solvent, a small amount of methyl ethyl ketone, acetone, trichlorotrifluoroethane, in a range that does not impair workability, disaster prevention safety, environmental safety, and manufacturing safety.
Methyl isobutyl ketone, cyclohexanone, ethyl acetate and the like may be used. The addition of the solvent may improve the swelling property of the monomer into the fluorine-containing polymer particles for seed polymerization.

The seed polymerization is carried out by a known method, for example, a method in which all the monomers are charged in a batch in the reaction system in the presence of particles of the polymer (b-1) for seed, or a reaction in which a part of the monomers is charged. After that, the rest can be continuously or dividedly charged, or the total amount of the monomers can be continuously charged.

Fluorine-containing polymer (b-
1) The polymer particle size in the aqueous dispersion of particles is 180 nm in order to suppress the particle size after seed polymerization to 200 nm or less.
It is below, and the concentration is preferably in the range of 30 to 70% by weight, and more preferably the concentration is in the range of 35 to 60% by weight. If the particle size after seed polymerization exceeds 200 nm, the sedimentation stability of the aqueous dispersion becomes poor, and even if the resin composition has the same composition, the minimum film forming temperature of the aqueous dispersion composition may increase.

The aqueous dispersion composition of the present invention comprises the above carboxyl group- and / or sulfonic acid group-containing fluororesin aqueous dispersion and a crosslinking agent having an aziridine group, a carbodiimide group or an oxazoline group. This cross-linking system is a novel cross-linking system.

Examples of the cross-linking agent having an aziridine group include XAMA2 and XAMA7 supplied from BF-Goodrich. Examples of the crosslinking agent having a carbodiimide group include UCARLNK Crosslinker XL-29SE supplied by Union Carbide. Further, examples of the crosslinking agent having an oxazoline group include Epocros K-supplied from Nippon Shokubai Co., Ltd.
1010E, EPOCROS K-1020E, EPOCROS K-1030E, EPOCROS K-2010E, EPOCROS K-2020E, EPOCROS K-2030
Examples include E and Epocros WS-500.

The method of addition is to add the cross-linking agent dissolved or dispersed in water to an aqueous dispersion of a fluoropolymer, or to dissolve the cross-linking agent in a small amount of a water-soluble organic solvent to give a fluorine-based polymer. A method of adding to the coalesced aqueous dispersion, a method of directly adding the above-mentioned crosslinking agent to the fluoropolymer aqueous dispersion, and the like are appropriately selected.

This crosslinking agent reacts with the carboxyl group and / or sulfonic acid group introduced into the fluorine-containing polymer to form a crosslinked structure. As a result, the hardness and water resistance of the coating film are improved, particularly the initial water resistance is improved and the stain resistance is improved.

The addition amount of this specific crosslinking agent is about 0.1 to 3 equivalents of the aziridine group, carbodiimide group or oxazoline group with respect to the carboxyl group and / or sulfonic acid group in the fluorine-containing polymer. Is preferably added as described above. If it is less than 0.1 equivalent, the effect of improving the hardness of the coating film by cross-linking, the effect of preventing stain attachment, and the effect of removing stain is small, and if it exceeds 3 equivalents, the water resistance of the coating film and the storage stability of the aqueous dispersion are reduced. Tend to do.

For crosslinking and curing the crosslinkable composition of the present invention, a coating film is first formed by an appropriate means, and then the coating film is usually coated with 0-2.
It may be dried at 00 ° C, preferably 5 to 100 ° C for 30 seconds to 1 week and cured.

The crosslinkable fluorine-containing resin aqueous dispersion composition of the present invention is used as an aqueous coating composition for a pigment, a thickener, a dispersant, an antifoaming agent, an antifreezing agent, a film-forming aid, an ultraviolet absorber and an antioxidant. By adding additives commonly used in water-based emulsion type paints, as a surface protective coating for inorganic base materials such as concrete, slate and ALC plates, metal base materials, and coating materials for coated paper, etc. Can be used as Further, by blending matte synthetic resin beads, natural stone, etc., it can be used as a decorative coating material. It can also be used as a water-based coating for exterior and / or interior of middle and low-rise buildings.

When used for paints, the blending ratio varies depending on the form of the paint and the coating method, but the solid content in the aqueous dispersion composition of the present invention is about 5 to 95% by weight of the paint, usually 20 to It may be 90% by weight.

As a coating method for such a water-based paint, a conventionally known coating method can be adopted. For coating, conventionally known coating equipment such as a brush, a roller, a roll coater, an air sprayer, an airless sprayer, an electrostatic coating machine, a dip coating machine, and an electrodeposition coating machine can be used.

The water-based paint is not limited to metals such as iron, aluminum, copper or alloys thereof, but also inorganic materials such as glass, cement and concrete, FRP, acrylic resin, vinyl chloride resin, polycarbonate resin, polyurethane resin and the like. It can be applied to various base materials such as resins, woods and fibers. Further, if necessary, a pretreatment or surface treatment such as applying a known water-based resin emulsion paint to the base material, an undercoating agent such as a solvent-based paint may be performed, and after applying an appropriate undercoat or precoat, the The coating composition of the invention can be applied. The coating system can perform coating as a clear coating, coating as an enamel coating, etc. on a base material having various well-known irregularities and color patterns and the like. After coating, the coating film is usually dried at 5 to 300 ° C. for 30 seconds to 1 week to be cured. The thickness of the coating film is not particularly limited, but is usually 1 to 200 μ
m, preferably 5 to 100 μm, more preferably 10 to
It is about 50 μm.

The coated product thus obtained is excellent in anti-staining property, anti-staining property, adhesion, weather resistance and chemical resistance, and the surface of the coating film has gloss, lubricity and hardness, so that it can be used in a wide range of applications. . That is, electric appliances (microwave oven, toaster, refrigerator, washing machine, hair dryer, TV,
Interiors and exteriors of video, amplifier, radio, electric kettle, rice cooker, radio cassette, cassette deck, compact disc player, video camera, etc., air conditioner indoor unit, outdoor unit, air outlet and duct, air purifier, heater Interior and exterior of air conditioners such as, fluorescent lamps, chandeliers, reflectors and other lighting fixtures, furniture, machine parts, ornaments, combs, eyeglass frames, natural fibers, synthetic fibers (threads and fabrics obtained from these), Office equipment (phones, facsimiles, copiers (including rolls), photographic machines, overhead projectors,
Interior / exterior of physical projectors, clocks, slide projectors, desks, bookshelves, lockers, document shelves, chairs, bookends, electronic whiteboards, etc., automobiles (wheels, door mirrors, malls, door knobs, license plates, handles, instruments) Mental panel etc.) or kitchen appliances (range hood,
Sink, cooktop, kitchen knife, cutting board, faucet of water supply, gas range, ventilation fan, etc.), for indoor coating of partitions, bath units, shutters, blinds, curtain rails, accordion curtains, walls, ceilings, floors, etc. For exteriors, exterior walls, handrails, gates, shutters and other general housing exteriors, building exteriors, ceramic sizing materials, foam concrete panels, concrete panels, aluminum curtain walls, steel sheets, galvanized steel sheets, stainless steel sheets, PVC sheets Building exterior materials, window glass, etc.
It has a wide range of other uses.

[0055]

EXAMPLES Next, the crosslinkable fluorine-containing resin aqueous dispersion composition of the present invention will be described with reference to synthesis examples and examples, but the present invention is not limited to these examples.

Synthesis Example 1 In a pressure-resistant reactor equipped with a stirrer and having an internal capacity of 1 liter, 500 ml of deionized water, 0.5 g of ammonium perfluorooctanoate, and polyoxyethylene monostearate (PO) were used.
E40) 0.05 g was charged, nitrogen injection and deaeration were repeated to remove dissolved oxygen, and then VdF / TFE / CTF
6 with a mixed monomer of 74/14/12 mol% ratio of E
The pressure was increased to 10 kgf / cm ² at 0 ° C. Next, 20 g of 1% ammonium persulfate aqueous solution and 1.5 g of ethyl acetate.
Was charged to start the polymerization. Pressure in the polymerization vessel is 10kgf
VdF / TFE / CTFE to be constant at / cm ²
The mixed monomer of 74/14/12 mol% was continuously supplied to continue the reaction, and the reaction was performed every 12 hours while adding 5 g of a 1% ammonium persulfate aqueous solution. 41 hours after the start of the polymerization, the inside of the polymerization vessel was returned to room temperature and atmospheric pressure to stop the polymerization, and an aqueous dispersion liquid of the particles of the fluoropolymer (A) (solid content concentration 42% by weight) was obtained. Laser light scattering particle size measuring device (Otsuka Electronics Co., Ltd.) was used to measure the average particle size of the particles in this aqueous dispersion.
Manufactured by DLS-3000).
It was 4 nm.

Synthesis Example 2 360 g of the aqueous dispersion of the fluoropolymer (A) produced in Synthesis Example 1 was charged into a four-necked flask having an inner volume of 500 ml equipped with a stirrer, a cooling tube, and a thermometer. 2.0 succinate sodium salt aqueous solution (Reodol OT-P manufactured by Kao Corporation, solid content concentration 70% by weight)
g was added. The mixture is heated in a water bath with stirring and the reaction system is at 80 ° C.
Methyl methacrylate (MMA) 71
g, butyl acrylate (BA) 25 g, methacrylic acid (MAc) 4 g and n-lauryl mercaptan (n-
LM) 0.1 g of the mixed monomer was added dropwise over 1 hour,
Immediately thereafter 10 ml of 2% ammonium persulfate aqueous solution
Was added to initiate seed polymerization. After 3 hours from the start of the reaction, the temperature of the polymerization system was raised to 85 ° C. and maintained for 1 hour, and then the reaction was stopped by cooling. Then adjust the pH to 7 with aqueous ammonia.
Then, water was further added to adjust the solid content concentration to 50% by weight, and the mixture was filtered through a 300-mesh wire net to obtain an aqueous dispersion of particles of a fluorinated seed polymer (B1) having a blue-white color.

With respect to this aqueous dispersion, the average particle size of seed particles was measured by the laser light scattering particle size measuring device.
Furthermore, the minimum film forming temperature (MFT) was measured using a thermal gradient type MFT measuring device (manufactured by Nippon Rikaki Co., Ltd.). The results are shown in Table 1.

Synthesis Examples 3 to 12 Fluorine-containing seed polymers (B2) to (B11) were produced in the same manner as in Synthesis Example 2 except that the components shown in Table 1 were used. I checked the properties. The results are shown in Table 1.
Shown in.

The abbreviations in Table 1 indicate the following, respectively. MMA: Methyl methacrylate BA: Butyl acrylate EA: Ethyl acrylate AAc: Acrylic acid MAc: Methacrylic acid AMPS: 2-Acrylamido-2methylpropanesulfonic acid n-LM: n-lauryl mercaptan

[0061]

[Table 1]

Examples 1 to 12 and Comparative Examples 1 and 2 (Preparation of pigment paste) To 10.35 parts by weight of water,
Dispersant 5027 made by San Nopco 5.25
7 parts by weight of CR-97 manufactured by Ishihara Sangyo Co., Ltd. as a pigment (titanium oxide).
0.00 parts by weight, Dow Corning F as an antifoaming agent
0.30 part by weight of S013B and 10 parts by weight of a 2% aqueous solution of Tyrose H4000P manufactured by Clariant were mixed, and this mixture was mixed and dispersed by a sand mill to prepare a pigment paste.

(Preparation of white paint) 100 parts by weight of the aqueous dispersions of the fluoropolymers (B1) to (B11) prepared in Synthetic Examples 2 to 12 were crosslinked with an aziridine group in the amounts shown in Table 2. Agent (XAMA7), cross-linking agent having carbodiimide group (XL-29SE) or cross-linking agent having oxazoline group (Epocros K-1020E), and mixed,
35.29 parts by weight of the above-prepared pigment paste, 2.8 parts by weight of a 10% aqueous solution of UH420 (manufactured by Asahi Denka Co., Ltd.) as a viscosity modifier, and diethyl adipate of 5. 0 parts by weight, FS013B as an antifoaming agent
0.1 part by weight was added and thoroughly mixed using a Disper stirrer to prepare a white paint.

The following properties were investigated using this white paint.
The results are shown in Table 2.

Hiding power A white paint is applied to a test paper so that the dry film thickness is 50 μm, and the hiding ratio is measured after drying for 16 hours. When the hiding ratio is 0.95 or more, the result is ◯.

Gloss White paint was spread on a glass plate with an applicator of 10 mil, dried at 80 ° C. for 1 hour, and then glossy at a reflectance of 60 degrees using a gloss meter (manufactured by Suga Test Instruments Co., Ltd.). Measure the value.

Pencil Hardness The hardness of the coating film subjected to the gloss test is measured according to the pencil hardness test of JIS K5400.

[0068] Epirettsu 3520WY55 and Epicure 8536WY primers aqueous dispersion were mixed in the (both Yuka Shell Co., Ltd.) 100 / 60.56 (weight ratio) is an epoxy resin coating agent onto adhesiveness aluminum plate Is applied and dried, then the above white paint is applied and dried at room temperature for 72 hours to prepare a test piece. For this test piece, cross-cut test (JIS
K5400), and the result is 100/100 is marked as ◯.

Water resistance A test piece prepared in the same manner as in the above adhesion test was immersed in distilled water for 24 hours.
After soaking for a period of time, wipe with a dry cloth and perform the above-mentioned cross-cut test within 10 minutes. The case where there is no change in appearance and the result of the cross-cut test is 100/100 is marked with ◯.

A smoke-resistant aluminum substrate was coated with the aqueous dispersion for a primer prepared in the same manner as in the above adhesion test, dried and then coated with the above white paint, and dried at room temperature for 14 days for testing. Make a piece. The test piece is placed in a box, and a treatment of burning two cigarettes every 2 hours is continued for 168 hours. The box cannot be opened during the test.
After the test, wash the test piece by gently rubbing it with a detergent (Spray White E diluted 10 times with water manufactured by KELITE CHEMICAL CO., LTD.), And visually observe the degree of smoke stain removal. Those that could be decontaminated are marked with a circle.

Handling stains For test pieces prepared in the same manner as the smoke stain resistance test,
30 ml of ASTM D2322 synthetic sweat, 3 g of carbon black and 7.5 g of humectant (Ridosol 501, Amchem Produkt)
The test piece is contaminated with a contaminant consisting of a mixture with the product) and dried at 60 ° C. for 1 hour. After cooling, the test piece is lightly rubbed with a detergent (Spray White E water diluted 10 times diluted by KELITE CHEMICAL) to wash, and the degree of removal of the above contaminants is visually observed. If there is no stain, mark ○.

Carbon Contamination Removability Carbon dispersed in ion-exchanged water at a concentration of 3% was uniformly applied to a test piece prepared in the same manner as the above smoke dirt resistance test with an airless spray gun, dried at 40 ° C. for 2 hours, and then run under running water. Underneath, the carbon on the surface of the coating film is washed with a brush and dried. The color difference (ΔE) before and after carbon contamination is measured with a color difference meter (manufactured by Suga Test Instruments Co., Ltd.). Evaluation is based on the following criteria. A: ΔE is less than 5 B: ΔE is 5 or more and less than 10 C: ΔE is 10 or more and less than 20 D: ΔE is 20 or more

Initial Water Resistance The aqueous dispersion for a primer prepared in the same manner as in the above adhesion test was applied, dried, and then the above white paint was applied, followed by 2 hours at room temperature.
A test piece is prepared by drying for 4 hours. After dipping this test piece in distilled water for 24 hours, the state of the coating film is observed. The case where there is no change in the appearance and the case where it does not dissolve is marked with a circle.

Weather resistance A test piece produced in the same manner as the smoke stain resistance test is subjected to an accelerated weather resistance test for 1000 hours in an accelerated weather resistance tester (SUV) to remove the gloss retention rate. Evaluation is based on the following criteria. A: Gloss retention rate is over 80% B: Gloss retention rate is 60-80% C: Gloss retention rate is less than 60%

MEK Rubbing Resistance Using a test piece prepared in the same manner as in the smoke stain resistance test, the coating film surface is wiped with a non-woven fabric impregnated with methyl ethyl ketone (MEK). The wiping operation is performed until the primer is visible or 50 round trips are completed. Record the number of round trips when the primer is visible. If the primer could not be seen after 50 round trips,> 50.

[0076]

[Table 2]

[0077]

[Table 3]

[0078]

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a novel cross-linking system in a fluorine-containing resin system, and to provide a coating film having improved hardness and a coating composition having excellent storage stability. A fluororesin aqueous dispersion composition can be provided.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C08K 5/353 C09D 127/12 C09D 5/00 C08J 3/03 CEW 127/12 (56) Reference JP-A-5-202261 ( JP, A) JP 10-226756 (JP, A) JP 2001-72725 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 27/12-27/20 C08J 3/03-3/09 C09D 5/00-5/46 C09D 127/12-127/20

Claims (2)

(57) [Claims] 1. Presence of polymer particles of fluoroolefin
It has a carboxyl group and / or a sulfonic acid group underneath.
And a fluorine-free monomer having an α, β-unsaturated group
A fluorine-containing resin having a fluorine content of 10% by weight or more and having a carboxyl group and / or a sulfonic acid group, and a crosslinking agent having an aziridine group, a carbodiimide group or an oxazoline group. A crosslinkable fluororesin aqueous dispersion composition comprising (only
However, the fluorine-containing resin has a carboxyl group as a crosslinkable functional group.
Fluorine-Containing Tree Having Only Group and / or Sulfonic Acid Group
It is fat) . 2. The crosslinking agent, wherein the crosslinking agent has an aziridine group.
The aqueous dispersion composition according to claim 1, which is an agent.