JP3303900B2 - Aqueous fluorinated polymer dispersion, aqueous paint and coated articles containing it - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorine-containing film which is excellent in film-forming properties, transparency in clear coating, adhesion, weather resistance, and provides a high gloss and excellent mechanical properties. The present invention relates to an aqueous polymer dispersion and an aqueous paint and a coated article containing the same.

[0002] More specifically, the present invention relates to a simple method containing a specific amount of alkyl acrylate and / or alkyl methacrylate and an ethylenically unsaturated monomer in the presence of fluorine-containing polymer particles. A fluorine-containing polymer aqueous dispersion obtained by seed polymerization of a monomer mixture, wherein a specific amount of a monomer having a cyclohexyl group is used as an ethylenically unsaturated monomer. The present invention relates to a combined aqueous dispersion, an aqueous paint containing the same, and a coated article.

[0003]

2. Description of the Related Art Fluorine-containing paints are used as weather-resistant paints for exterior and interior of middle and low-rise buildings. Various techniques have been developed to obtain this fluorine-based paint. Many fluorinated paints are of the organic solvent dispersion type, but the use of an organic solvent is problematic in terms of safety and environmental protection. The following method is known as a method for producing an aqueous dispersion of a fluorinated polymer.

Japanese Patent Publication No. 4-55441 and JP-A-3-7784 disclose an emulsion polymerization of an ethylenically unsaturated monomer in the presence of vinylidene fluoride (VdF) copolymer particles in an aqueous medium. It is described that the film-forming property and film transparency which cannot be obtained by the emulsion blending can be obtained by performing the method, but hexyl methacrylate is exemplified as a (meth) acrylate having an alkyl group having 1 to 18 carbon atoms. It is just being done. No mention is made of (meth) acrylic acid esters having a cyclohexyl group having a cyclic structure of hexyl, vinyl ethers, acetates, and the like, and there is no description on adhesion.

Japanese Patent Application Laid-Open No. 225550/1990 describes cyclohexyl vinyl ether as an example of an aqueous dispersion of a water-dispersible weather-resistant coating material obtained by copolymerizing an alkyl vinyl ether with a fluoroolefin and an alkyl vinyl ether. There is no description or suggestion that the post-polymerization of an alkyl ester or the copolymerization of cyclohexyl vinyl ether improves the adhesion to a substrate.

[0006] Japanese Patent Application Laid-Open No. 6-228491 discloses that a fluoroolefin copolymer is post-polymerized into an aqueous resin dispersion obtained by copolymerizing an alkyl vinyl ether with a fluoroolefin, and the fluoropolymer which is post-polymerized therein. Although it is described that cyclohexyl vinyl ether is used as a monomer of the olefin copolymer, it is described that the post-polymerization is a fluoroolefin copolymer, and that only the non-fluorinated alkyl ester is post-polymerized. Further, there is no description or suggestion that the copolymerization of cyclohexyl vinyl ether improves the adhesion to the substrate.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to provide a film having excellent film forming properties, transparency in clear coating, adhesion, weather resistance, high gloss, and high gloss. It is an object of the present invention to obtain a fluorine-containing polymer aqueous dispersion capable of providing a coating film having excellent mechanical properties, an aqueous coating material containing the same, and a coated article.

[0008] The present inventors have proposed particles of a fluorine-containing polymer,
Among them, VdF polymers, especially VdF7
0 to 95% (mol%, the same applies hereinafter) and CTFE5 to 3
In an aqueous dispersion containing particles of a fluorinated polymer having a limited composition containing 0%, a specific amount is contained in the presence of the particles of the fluorinated polymer (hereinafter, may be referred to as seed particles). By subjecting a specific amount of an alkyl acrylate and / or methacrylic acid alkyl ester and an ethylenically unsaturated monomer, particularly a monomer having a cyclohexyl group, to seed polymerization, a molecular-level aqueous dispersion of a compatible solution is obtained. That the dispersion can achieve the above object,
In addition, between cyclohexyl methacrylate, cyclohexyl vinyl ether, and the like, and normal hexyl methacrylate or isohexyl methacrylate having a chemical structure similar to these, such as normal hexyl or isohexyl vinyl ether, there is a large difference in the point of an adhesion improving effect. Surprisingly, they found that only the monomer having a cyclohexyl group as described above had a remarkable effect in improving the adhesion, and completed the present invention.

[0009]

According to the present invention, there is provided an alkyl acrylate having 1 to 18 carbon atoms and / or a carbon number of alkyl group in the presence of 100 parts by weight of particles of a fluorine-containing polymer. By emulsion polymerization in an aqueous medium of 20 to 100 parts by weight of a monomer mixture containing an alkyl methacrylate of 1 to 18 and an ethylenically unsaturated monomer copolymerizable with these esters. An aqueous dispersion of a fluorinated polymer, wherein the average particle diameter of the polymer particles obtained by emulsion polymerization is 0.05 to 3 μm, wherein cyclohexyl is contained in the ethylenically unsaturated monomer. The monomer having a group is 0.1% of the monomer mixture.
5 to 45% by weight , and a cyclohexyl group
Is a monomer having cyclohexyl acrylate,
Cyclohexyl and cyclohexyl vinyl ether
About fluorine-containing polymer aqueous dispersion with at least Tanedea characterized Rukoto selected from the group consisting of Le.

[0010] The present invention also relates to an aqueous paint containing the aqueous fluoropolymer dispersion.

[0011] The present invention also relates to a coated article obtained by applying the water-based paint.

[0012]

Functions and Examples The fluorinated polymers used as seed particles in the present invention include chlorotrifluoroethylene (CTFE) and tetrafluoroethylene (TF).
E), hexafluoropropylene (HFP), vinylidene fluoride, trifluoroethylene (TrFE),
Homopolymers or copolymers such as vinyl fluoride (VF) or ethylenically unsaturated monomers copolymerizable with these monomers such as vinyl ethers such as cyclohexyl vinyl ether (CHVE) and ethyl vinyl ether (EVE) And copolymers with monomers. Among these, CTFE / vinyl ether-based copolymers, VdF-based copolymers and the like are preferably used from the viewpoint of compatibility with the acrylic resin. Further, among these copolymers, VdF-based copolymers are preferred, in which case 70 to 95% of VdF and 5 to 30% of CTFE, preferably 75 to 90% of VdF and 10 to 25 of CTFE.
%, More preferably 75-85% VdF and CTF
A polymer containing 15 to 25% of E is preferably used.

When the VdF is 70% or more, the compatibility between the seed particles and the polymer comprising the alkyl acrylate and / or the alkyl methacrylate and the ethylenically unsaturated monomer is improved, and the emulsion is dried. Excellent properties due to compatibility, such as excellent transparency and mechanical properties of the formed film (hereinafter referred to as cast film), can be obtained. If the CTFE is less than 5%, the solubility of the seed particles in the alkyl acrylate and / or methacrylic acid ester and the ethylenically unsaturated monomer may decrease. In some cases, the swelling of the monomer is difficult to be performed quickly, and the cast film from the obtained emulsion may have reduced transparency. In some cases, it is difficult to obtain sex.

The content of a monomer copolymerizable with a monomer such as VdF or CTFE is 0 to 30%, preferably 10 to 30%.
-25%, more preferably 10-20%.

When the seed particles are made of CTFE, VdF and TFE or VF, the solubility of the seed particles in the monomer is improved, and the swelling of the monomer in the seed particles during the seed polymerization is reduced. The process is carried out quickly, and the cast film from the obtained emulsion has improved transparency, and gloss can be obtained even when a coating film is prepared from a paint.

The seed particles are CTFE, VdF and H
When FP or TrFE is used, the seed particles are easily dissolved in the monomer, the compatibility between HFP and TrFE and the acrylic and / or methacrylic copolymer is improved, and the cast from the obtained emulsion is improved. The transparency of the film is improved, and a high gloss coating film is obtained.

The average particle size of the fluorinated polymer in the present invention is closely related to the average particle size of the fluorinated polymer after the seed polymerization, and the average particle size of the fluorinated polymer after the seed polymerization is determined. 0.05-3 μm, preferably 0.05-
In order to make the thickness 0.5 μm, more preferably 0.1 to 0.2 μm, 0.05 to 2.8 μm, preferably 0.05 to 2.8 μm.
0.48 μm, more preferably 0.09 to 0.18 μm
Is desirable.

The fluorine-containing polymer used as the seed particles can be obtained by a usual emulsion polymerization method.

For example, 0.01 to 1.0% of a fluorinated reactive emulsifier having a hydrophilic site and 0 to 1.0% of a fluorinated emulsifier coexist with water, and a monoolefin containing a fluoroolefin. It can be adjusted by emulsion polymerization of the monomer mixture.

Further, the amount is 1.0% by weight or less, preferably 0.5% by weight or less, more preferably 0.2% by weight with respect to water.
0.001 to 0.1% by weight, preferably 0.01 to 0.05% by weight of a nonionic non-fluorine-based interface based on the following (the lower limit is usually 0.01% by weight) of a fluorine-based surfactant and water. It can be prepared by emulsion polymerization of a monomer mixture containing a fluoroolefin in the presence of an activator.

The aqueous dispersion obtained by these methods can stably contain seed particles having an average particle diameter of 0.2 μm or less at a high concentration of 30 to 50% by weight.

Examples of the fluorine-based reactive emulsifier having a hydrophilic site include CF ₂ ＣＦCF— (CF ₂ CFX)
_n Y ( _where X is F or CF ₃ , Y is SO ₃ M, COO
M (M is a hydrogen atom, amine, ammonium or alkali metal, n represents an integer), CF ₂ ＣＦCF—O (CF
X) _n Y ( _where X, Y and n are the same as above), CH _{2
= CF-CF 2 -O (CF} (CF 3) CF 2 O) n -CF
(CF ₃ ) Y (where Y and n are the same as above), CF _{2
= CF-CF 2 -O (CF} (CF 3) CF 2 O) n -CF
(CF ₃ ) Y (wherein, Y and n are the same as those described above), and from the viewpoint of solubility in water and surface activity, n ranges from 0 to 3. Is preferred.

More specifically, CH ₂ ＣＦCF—CF ₂ —O
A structure of ((CF ₃ ) CFCF ₂ O) _n- (CF ₃ ) CFCOOH wherein n is 0 to 2 is used.

The polymerization temperature is 20 to 120 ° C., preferably 3
The temperature is between 0 and 70C. When the polymerization temperature is lower than 20 ° C., the stability of the resulting latex generally decreases, and when the polymerization temperature is higher than 120 ° C., the polymerization rate tends to stall due to chain transfer. The polymerization is usually carried out by heating under a pressure of 1.0 to 50 kgf / cm ² (gauge pressure) for 5 to 100 hours, depending on the type of the polymer.

Examples of the fluorine-based emulsifier used for emulsion polymerization of seed particles include 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 represents F or H) and its alkali metal salt, ammonium salt, amine salt or quaternary ammonium salt: Y (CH ₂ CF ₂ ) _m C
An acid represented by OOH (m represents an integer of 6 to 13, Y represents F or Cl), an alkali metal salt, an ammonium salt, an amine salt or a quaternary ammonium salt thereof can be used. More specifically, ammonium salts of perfluorooctanoic acid, ammonium salts of perfluorononanoic acid and the like are used. In addition, a known fluorine-based surfactant can be used.

In the emulsion polymerization for obtaining seed particles, a small amount of a nonionic non-fluorinated surfactant can be used in the presence of a fluorine-based surfactant, and specific examples thereof include polyoxyethylene alkyl ethers. , Polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl esters, glycerin esters and derivatives thereof. More specifically, polyoxyethylene alkyl ethers include polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene behenyl ether, and the like. Examples of oxyethylene alkyl phenyl ethers include polyoxyethylene nonyl phenyl ether and polyoxyethylene octyl phenyl ether. Examples of polyoxyethylene alkyl esters include polyethylene glycol monolaurate, polyethylene glycol monooleate, and monostearic acid. Polyethylene glycol, etc., and sorbitan alkyl esters such as polyoxyethylene monolaurate. Vitan, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate, etc., and polyoxyethylene sorbitan monolaurate and monopalmitate as polyoxyethylene sorbitan alkyl esters Examples include polyoxyethylene sorbitan and polyoxyethylene sorbitan monostearate, and glyceryl esters such as glyceryl monomyristate, glyceryl monostearate, and glyceryl monooleate. Further, as these derivatives, polyoxyethylene alkylamine, polyoxyethylene alkylphenyl-formaldehyde condensate,
And polyoxyethylene alkyl ether phosphate. Particularly preferred are polyoxyethylene alkyl ethers and polyoxyethylene alkyl esters having an HLB value of 10 to 18, and specifically, polyoxyethylene lauryl ether (E
O: 5 to 20, EO indicates the number of ethylene oxide units) Polyethylene glycol monostearate (EO:
10-55) and polyethylene glycol monooleate (EO: 6-10).

In the present invention, in the presence of seed particles,
A monomer mixture comprising an alkyl acrylate and / or an alkyl methacrylate and an ethylenically unsaturated monomer is seed polymerized.

In the present invention, the alkyl group has 1 to 1 carbon atoms.
Examples of the alkyl acrylate 18 include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-amyl acrylate, isoamyl acrylate, n-hexyl acrylate, and acrylic 2-ethylhexyl acid, lauryl acrylate, and the like. Among these, alkyl acrylates having 1 to 3 carbon atoms in the alkyl group are preferred, and alkyl acrylates having 1 or 2 carbon atoms in the alkyl group are particularly preferred. These monomers are used alone or in combination of two or more.

The alkyl group has 1 to 18 carbon atoms.
Examples of the alkyl methacrylate include: methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-amyl methacrylate, isoamyl methacrylate, n-hexyl methacrylate, methacrylic acid 2
-Ethylhexyl, lauryl methacrylate and the like. Of these, the alkyl group has 1 carbon atom.
To 3 alkyl methacrylates are preferred, and alkyl methacrylates having 1 or 2 carbon atoms in the alkyl group are particularly preferred. These monomers are used alone or in combination of two or more.

In the present invention, when the alkyl acrylate and the alkyl methacrylate are used in combination, the ratio of the two is not particularly limited, and may be selected according to the desired properties of the aqueous dispersion of polymer particles. Can be appropriately selected.

The ethylenically unsaturated monomer copolymerizable with the alkyl acrylate and / or the alkyl methacrylate includes, for example, vinyl compounds, especially monomers having a cyclohexyl group.

Examples of the vinyl compound in the present invention include acrylamide, methacrylamide, N-methylacrylamide, N-methylmethacrylamide, N-methylolacrylamide, N-methylolmethacrylamide,
Amide compounds such as -alkylacrylamide, N-alkylmethacrylamide, N, N-dialkylacrylamide, N, N-dialkylmethacrylamide, 2-hydroxyethyl acrylate, N, N-dialkylaminoethyl acrylate, glycidyl acrylate, Acrylates such as fluoroalkyl acrylate, 2-hydroxyethyl methacrylate, N, N-dialkylaminoethyl methacrylate, glycidyl methacrylate (GM
A), fluoroalkyl methacrylate, methacrylates such as ethylene glycol dimethacrylate, vinyl ether compounds such as allyl glycidyl ether,
Examples include conjugated dienes such as 1,3-butadiene, isoprene, and chloroprene; aromatic vinyl compounds such as styrene, α-methylstyrene, halogenated styrene, and divinylbenzene; and vinyl cyanide compounds such as acrylonitrile and methacrylonitrile. it can. These monomers are used alone or in combination of two or more.

Veova 9 and Veova 10 which are a mixture of vinyl acetate and a vinyl ester of a branched alkyl.
(Shell Chemical) and the like.

Examples of the monomer having a cyclohexyl group include cyclohexyl acrylate (CHA), cyclohexyl methacrylate (CHMA), and cyclohexyl vinyl ether (CHVE). CHMA and CHVE are preferred from the viewpoint of weather resistance.

The amount of the monomer having a cyclohexyl group used is 0.5 to 45% by weight based on the total monomer mixture of the alkyl acrylate and / or the alkyl methacrylate and the ethylenically unsaturated monomer. %, Preferably 1-20% by weight, 0.5% by weight
If the amount is less than 50%, the adhesion of the coating composition to the substrate, which is the object of the present invention, is not sufficient. If the amount exceeds 45% by weight, the compatibility with the seed particles deteriorates, and the transparency of the aqueous dispersion dried film decreases. Also, mechanical properties such as elongation and elastic modulus of the film are reduced. Further, there is a tendency that the gloss of the coating film is reduced and the weather resistance is reduced.

The total amount of the ethylenically unsaturated monomer and the alkyl acrylate and / or alkyl methacrylate used is 20 to 100 parts per 100 parts (parts by weight, hereinafter the same) of the seed particles. Preferably it is 30 to 100 parts, more preferably 40 to 100 parts. If the amount is less than 20 parts, the transparency and gloss and adhesion at the time of coating tend to be low. If it exceeds 100 parts, the weather resistance tends to decrease.

The seed polymerization of the alkyl acrylate and / or the alkyl methacrylate and the ethylenically unsaturated monomer can be carried out under the same conditions as those of ordinary emulsion polymerization. For example, a surfactant, a polymerization initiator, a chain transfer agent, and if necessary, a chelating agent, a pH adjuster, a solvent, and the like are added to an aqueous medium containing seed particles, and are added at 20 to 90 ° C., preferably 20 to 80 ° C. C., more preferably at a temperature of 30 to 70.degree. C. for 0.5 to 6 hours.

In the seed polymerization, a method in which the total amount of the monomers is charged into the reaction system in the presence of seed particles, a method in which a part of the monomers are charged and reacted, and the remaining is continuously or dividedly charged. Any method of continuously charging the total amount of the monomers may be used.

When the alkyl acrylate and / or methacrylate and the ethylenically unsaturated monomer are seed-polymerized by an emulsion polymerization method in the presence of seed particles, first, these monomers swell into the seed particles. At this point, an aqueous dispersion in which the seed particles are uniformly dissolved in the monomer is formed at this point, and the monomer is polymerized by the addition of the polymerization initiator to form a compatible solution particle in which the molecular chains are entangled. . An interpenetrating network (IPN) can also be formed by copolymerizing a polyfunctional monomer. Examples of the polyfunctional monomer include monoglycol dimethacrylate and diglycol dimethacrylate.

As the surfactant used for the seed polymerization, an anionic surfactant, a nonionic surfactant, or a combination thereof is used, and an amphoteric surfactant can also be used. As the anionic surfactant,
Esters of higher alcohol sulfates such as sodium alkyl sulfonate, sodium alkyl benzene sulfonate, sodium dialkyl succinate sulfonate, sodium alkyl diphenyl ether disulfonate and the like are used. Nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene alkyl phenyl esters, sorbitan alkyl esters, glycerin esters, and derivatives thereof Are used. Lauryl betaine or the like is used as the amphoteric surfactant. Further, a so-called reactive emulsifier which can be copolymerized with an acrylate, a methacrylate or an ethylenically unsaturated monomer, for example, sodium styrenesulfonate, sodium alkylsulfosuccinate and the like can also be used. The amount of surfactant used is usually
It is about 0.05 to 5.0 parts per 100 parts in total of the alkyl acrylate and / or the alkyl methacrylate and the ethylenically unsaturated monomer.

The polymerization initiator is not particularly limited as long as it generates a radical which can be subjected to a free radical reaction in an aqueous medium at a temperature between 20 ° C. and 90 ° C. In some cases, the polymerization initiator may be used in combination with a reducing agent. Is also possible. Usually, water-soluble polymerization initiators include persulfates and hydrogen peroxide, and reducing agents include sodium pyrobisulfite, sodium bisulfite, sodium L-ascorbate and the like. Examples of the oil-soluble polymerization initiator include diisopropyl peroxydicarbonate (IPP), benzoyl peroxide, dibutyl peroxide, azobisisobutyronitrile (AIBN) and the like. The amount of the polymerization initiator to be used is generally about 0.05 to 2.0 parts per 100 parts in total of the alkyl acrylate and / or the alkyl methacrylate and the ethylenically unsaturated monomer.

The polymerization temperature is 20 to 90 ° C., preferably 3 to 90 ° C.
The range of 0-70 degreeC is good.

Examples of the chain transfer agent include halogenated hydrocarbons (eg, chloroform, carbon tetrachloride, etc.), mercaptans (eg, n-dodecyl mercaptan, t-dodecyl mercaptan, n-octyl mercaptan, isooctyl thioglycolate, etc.). Is used. Among these, isooctyl thioglycolate and n-dodecyl mercaptan are preferred from the viewpoint of chain transfer effect and odor. The amount of the chain transfer agent used is usually
The amount is about 0 to 5.0 parts per 100 parts of the total of the alkyl acrylate and / or the alkyl methacrylate and the ethylenically unsaturated monomer.

As the solvent, a small amount of methyl ethyl ketone, acetone, trichlorotrifluoroethane, methyl isobutyl ketone, ethyl acetate and the like can be used in a small amount within a range that does not impair workability, disaster prevention safety, environmental safety and production safety. . Addition of a solvent may improve the monomer swelling of the seed particles.

As described above, an aqueous dispersion of the fluorinated polymer of the present invention is obtained.
Arbitrary T between -35 ° C and 25 ° C from the viewpoint of improving adhesion
It is more preferable to carry out seed polymerization of an alkyl methacrylate and a monomer copolymerizable therewith in the presence of an aqueous dispersion containing fluorine-containing polymer particles having g. Thereby, the minimum film formation temperature of the aqueous fluoropolymer dispersion is set to 0 ° C. by selecting the Tg of the seed particles.
It can be set arbitrarily in the range of -70 ° C.

Alkyl methacrylates having 1 to 6 carbon atoms in the side chain are preferred because they have little effect on the decrease in weather resistance. However, as the number of carbon atoms in the side chain decreases, Vd increases.
In order to improve the compatibility with the F copolymer resin, alkyl methacrylate having 1 to 3 carbon atoms in the side chain is more preferable, and methyl methacrylate having 1 carbon atom in the side chain is more preferable.

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

When emulsion polymerization is carried out in the presence of the aqueous dispersion particles, a hydrophilic portion is incorporated into the low molecular weight polymer or oligomer molecule as a copolymerizable monomer having an ethylenically unsaturated bond. Can also be used. The hydrophilic site represents a site having a hydrophilic group or a hydrophilic bond. This hydrophilic group is
Any of anionic, nonionic, amphoteric and combinations thereof may be used, but nonionic and anionic hydrophilic groups are preferred. Also, known reactive emulsifiers are included.

Commercially available examples of the monomer and the reactive emulsifier include Blemmer PE-350, Blemmer PME-400, Blemmer 70 PEP350B,
UNIOX PKA5002, UNIOX PKA50
03, UNIOX PKA5004 (Nippon Oil & Fats Co., Ltd.)
NK ester M-40G, NK ester M-90
G, NK ester M-230G, NK ester AMP-
60G, NK ester CB-1, NK ester SA, N
Examples thereof include K ester A-SA (manufactured by Shin-Nakamura Chemical Co., Ltd.), Eleminol JS2, and Eleminol RS30 (manufactured by Sanyo Chemical Industries, Ltd.).

Among the above monomers, allyl ether derivatives which do not adversely affect the decrease in weather resistance are preferred.

In the present invention, the average particle diameter of the particles of the fluorinated polymer in the aqueous dispersion obtained by the seed polymerization is preferably 0.05 to 3 μm, more preferably 0.05 to 0.5 μm. In particular, it is 0.1 to 0.2 μm. When the average particle size is less than 0.05 μm, the viscosity of the aqueous dispersion increases, and a high-concentration aqueous dispersion cannot be obtained. If the average particle diameter of the particles of the fluorinated polymer exceeds 3 μm, sedimentation and further coagulation of the particles occur during storage of the aqueous dispersion. In addition, there arises a problem such as lack of gloss at the time of coating film preparation.

The aqueous fluorinated polymer dispersion of the present invention comprises
By adding additives commonly used in aqueous emulsion paints, such as pigments, thickeners, dispersants, defoamers, antifreezing agents, film-forming aids, etc. as water-based paints, and also for concrete surface protection coatings As a coating material for coated paper.

The aqueous fluoropolymer dispersion of the present invention can also be used for aqueous coatings for exterior and / or interior of low-rise buildings.

As a method of applying the water-based paint of the present invention, a conventionally known coating method can be adopted. For the coating, conventionally known coating tools such as a brush, a roller, a roll coater, an air spray, an airless spray, an electrostatic coating machine, a dip coating machine, and an electrodeposition coating machine can be used.

The water-based paint of the present invention comprises iron, aluminum,
Not limited to metals such as copper or their alloys, inorganic materials such as glass, cement, concrete, FRP,
It is applicable to various base materials such as resins, such as acrylic resin, vinyl chloride resin, polycarbonate resin, and polyurethane resin, wood, and fiber. If necessary, the base material may be subjected to a preliminary treatment or a surface treatment. The coating composition of the present invention can be applied after appropriately applying an undercoat or a precoat. After coating, the coating film is dried and cured usually at 5 to 300 ° C. for 30 seconds to 1 week, depending on the type of the curing agent. Although the thickness of the coating film is not particularly limited, it is usually 1
It is about 200 to 200 m, preferably about 5 to 100 m, more preferably about 10 to 50 m.

The coated product thus obtained is excellent in adhesion, weather resistance and chemical resistance, and has a lubricating surface, so that it can be used in a wide range of applications. That is, the interior and exterior of electrical products (microwave oven, toaster, refrigerator, washing machine, hair dryer, TV, video, amplifier, radio, electric kettle, rice cooker, radio cassette, cassette deck, compact disc player, video camera, etc.) Interior and exterior of air conditioners such as indoor units, outdoor units, air outlets and ducts of air conditioners, air purifiers, heaters, etc., lighting equipment such as fluorescent lamps, chandeliers, reflectors, furniture, machine parts, ornaments, combs, Glasses frames, natural fibers, synthetic fibers (threads and woven fabrics), office equipment (telephones, facsimile machines, copiers (including rolls), cameras, overhead projectors, real projectors, clocks, slide projectors, Desks, bookshelves, lockers, paper shelves, chairs, bookends, Interior and exterior of automobiles (wheels, door mirrors, malls, door knobs, license plates, handles, instrument panels, etc.), or kitchen utensils (range hoods, sinks, countertops, kitchen knives, cutting boards, water supplies) Faucets, gas ranges, ventilation fans, etc.), for indoor painting of partitions, bath units, shutters, blinds, curtain rails, accordion curtains, walls, ceilings, floors, etc. It has a wide range of applications, such as ceramic housing sizing materials, building exterior materials such as foamed concrete panels, concrete panels, curtain walls, PVC steel sheets and sheets, window glass, etc., such as general housing exteriors such as gates and shutters, and building exteriors.

Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

Synthesis Example 1 500 ml of deionized water, 0.5 g of ammonium perfluorooctanoate and CH ₂ ＝ CF—CF ₂ —OCF were placed in a pressure-resistant reaction vessel equipped with a stirrer having a content of 1 liter.
After charging 0.5 g of a reactive emulsifier having a structure represented by (CF ₃ ) CF ₂ O—CF (CF ₃ ) COOH, repeating nitrogen injection and degassing to remove dissolved air, VdF / TFE
The mixture was pressurized at 60 ° C. to 8 kgf / cm ² with a mixed monomer having a ratio of 74/14/12 mol% of / CTFE. Next, 1.5 g of ethyl acetate was press-fitted, 0.2 g of ammonium persulfate was further charged, and the pressure in the tank was 8 kgf / cm ^2.
The mixed monomer was continuously supplied so as to obtain a reaction, and the reaction was carried out for 45 hours. Then, the inside of the tank was returned to normal temperature and normal pressure to complete the reaction.

The following items were measured for the aqueous dispersion.

Solid content: dried at 150 ° C. in a vacuum dryer for 1 hour, and the weight after drying was expressed as a percentage of the weight of the aqueous dispersion before drying.

Average particle size: Measured with a laser light scattering particle size measuring device (Otsuka Electronics ELS-3000).

Table 1 shows the results.

Synthesis Examples 2 to 5 The aqueous dispersions of Synthesis Examples 2 to 5 were prepared in the same manner as in Synthesis Example 1 except that the composition of the mixed monomers was changed to the composition shown in Table 1. The same measurement as in Synthesis Example 1 was performed. Table 1 shows the results.

Synthesis Example 6 In a 200 ml autoclave equipped with a stainless steel stirrer, 20.0 g of cyclohexyl vinyl ether (CHVE) having the composition shown in Table 1 and ethyl vinyl ether (E) were used.
VE) 11.4 g, a macromonomer having a hydrophilic site (PKA5003, manufactured by NOF Corporation) 4.5 g, ion-exchanged water 66.1 g, ammonium perfluorooctanoate (emulsifier) 0.35 g, potassium carbonate (K ₂ CO ₃₎ )
0.35 g, sodium bisulfite (NaHSO ₃ )
0.02 g, ammonium persulfate (initiator) 0.08 g
And cooled with ice to remove 3.5 kg / cm of nitrogen gas.
Pressurize to ² and degas. This pressure degassing is repeated twice, and after degassing to 10 mmHg to remove dissolved oxygen, chlorotrifluoroethylene (CTFE)
38.0 g was charged and reacted at 30 ° C. for 12 hours to obtain an aqueous dispersion of Synthesis Example 6, and the same measurement as in Synthesis Example 1 was performed. Table 1 shows the results.

[0065]

[Table 1]

Example 1 70 g of the aqueous dispersion obtained in Synthesis Example 1 was charged into a 200-ml four-necked flask equipped with a stirring blade, a cooling tube, and a thermometer, and charged with JS2 (manufactured by Sanyo Chemical Industries, Ltd.). Was added in an amount of 0.5% by weight based on the solid content of the aqueous dispersion. Heat in a water bath with stirring, and when the tank temperature reaches 80 ° C,
10 g of methyl methacrylate (hereinafter referred to as MMA), cyclohexyl methacrylate (hereinafter referred to as CHMA) 1.2
g, 1.5 g of PKA5003 (manufactured by NOF Corporation) and 0.3 g of isooctyl thioglycolate in JS2
An emulsion emulsified with a 0.5% by weight aqueous solution (manufactured by Sanyo Chemical Industries) was added dropwise over 1 hour. Immediately thereafter, 1 ml of a 2% by weight aqueous solution of ammonium persulfate was added to start the reaction. Three hours after the start of the reaction, the temperature in the tank was raised to 85 ° C., and the temperature was maintained for one hour.
Was adjusted to 7, and then filtered through a 300-mesh wire gauze to obtain a blue-white aqueous dispersion of a fluorinated polymer.

The following test was conducted on this aqueous dispersion.

(1) Evaluation of Characteristics of Aqueous Dispersion Solid Concentration and Average Particle Diameter: Same as above Minimum Film Forming Temperature (MFT): A continuous film was formed using a thermal gradient tester (manufactured by Rigaku Corporation). The lowest temperature was measured.

(2) Evaluation of Aqueous Dispersion Dry Film Properties Transparency: The aqueous dispersion was poured into a 10 cm diameter petri dish so that the dry film thickness became 200 μm.
Dry at 0 ° C. for 24 hours. This film was measured for light transmittance at a wavelength of 800 nm, and evaluated as follows.

A: 90% or more transmittance B: 80 to less than 90% C: 60% to less than 80% D: Less than 60% transmittance Dry film mechanical properties of aqueous dispersion: JIS K6301
The dried film was cut out into a No. 2 dumbbell according to the above-mentioned method, and the elongation and the elastic modulus were measured.

(3) Evaluation of coating film characteristics 50 parts of titanium oxide (trade name: CR90 (manufactured by Ishihara Sangyo KK)) was used as a filler with respect to 100 parts of the solid content of the aqueous dispersion obtained in Example 1. Nopco Spas SN as an agent
5027 (manufactured by San Nopco Co., Ltd.), 1 part of ethylene glycol as a deicing agent, 0.5 part of FS Antifoam 013B (manufactured by Nippon Emulsion Co., Ltd.) as a defoaming agent, and UH420 (Asahi Denka Co., Ltd.) as a thickening agent 0.5 part, Texanol CS12 (manufactured by Chisso Corporation) 1 as a film forming aid
Five parts were added and mixed well using a disper stirrer to prepare a paint.

Initial gloss: The obtained paint was spread on an aluminum plate using an applicator to a coating thickness of 20 μm, dried at room temperature for one week, and then subjected to a gloss meter (Suga Test Instruments Co., Ltd.). )) Was used to measure the gloss at a reflection angle of 60 °.

Pencil hardness: The hardness of the coating film obtained on the aluminum plate was measured by a JIS K5400 pencil hardness test.

Adhesion: Using the aqueous dispersion of Example 1,
The prepared coating was spread using an applicator so as to have a coating thickness of 40 μm on a slate plate coated with (1) an aqueous acrylic sealer Movinyl 940 (manufactured by Hoechst Synthetic), and dried at room temperature for one week. (2) Elastic acrylic sealer An airless spray gun was applied to a slate plate coated with a high-proof middle coat (manufactured by Nippon Special Paint) to a coating thickness of 40 μm, and dried at room temperature for one week. JIS K5400 for each of the above
Based on the above, 25 squares were formed at 2 mm intervals, and a tape peeling test was performed. Table 2 shows the number of squares remaining when each sealer was used.

Water immersion test: The coated plate obtained by applying each of the sealers was immersed in ion-exchanged water at room temperature for 10 days.
After being taken out and dried for one day, gloss and adhesion were measured by the same methods as described above.

Accelerated weather resistance test: The test plate used for the gloss measurement applied to an aluminum plate to a thickness of 20 μm with an applicator was exposed to an eye super UV tester (SUV) (manufactured by Iwasaki Electric Co., Ltd.) for 1000 hours, and then the gloss was measured. It measured and expressed the percentage with respect to the initial gloss by gloss retention (%). In addition, (1) an acrylic sealer produced during the adhesion test,
(2) After the coated plate coated with the elastic acrylic sealer was exposed to SUV for 1000 hours, the adhesion was measured by the same method as described above.

Table 2 shows the results.

Examples 2 to 14 Using the aqueous dispersions and the monomer mixtures of the synthesis examples shown in Table 2, seed polymerization was carried out in the same manner as in Example 1 to obtain aqueous dispersions of Examples 2 to 14. Then, the same test as in Example 1 was performed. Table 2 shows the results.

[0079]

[Table 2]

In Table 2, abbreviations indicate the following monomers.

* 1): Methyl methacrylate, * 2): Ethyl acrylate, * 3): Cyclohexyl methacrylate, * 4): Cyclohexyl acrylate, * 5): Cyclohexyl vinyl ether, * 6): Normal hexyl methacrylate , * 7): normal hexyl vinyl ether, * 8): hydroxyethyl methacrylate, * 9):
Glycidyl methacrylate, * 10): γ-trimethoxysilane methacrylate, * 11) Methacrylic acid As is clear from the results in Table 2, the coating obtained by seed polymerization using a monomer having a cyclohexyl group was used. It can be seen that the adhesion to the substrate is excellent.

Comparative Examples 1 to 11 Seed polymerization was carried out in the same manner as in Example 1 by using the aqueous dispersions of the synthesis examples shown in Table 3 and the monomers or mixtures thereof. The test was performed in the same manner as in Example 1 by taking the liquid. However, only Comparative Example 5 did not undergo seed polymerization. Table 3 shows the results. In addition,
The abbreviations of the monomers are the same as in Table 2.

[0083]

[Table 3]

As is evident from the results in Table 3, when the monomer having a cyclohexyl group was not used, the obtained paint had no adhesion to the substrate, and the monomer having the cyclohexyl group had no adhesion. When the amount of the monomer used exceeds 45%,
It can be seen that the compatibility with the fluororesin is reduced, the transparency of the dried film of the aqueous dispersion is impaired, and the gloss of the coating film is also reduced.

When the monomer mixture exceeds 100 parts by weight with respect to 100 parts by weight of the fluorine-containing polymer particles, the gloss retention becomes poor and the weather resistance is impaired.

[0086]

According to the aqueous fluoropolymer dispersion of the present invention, a coating film having excellent film forming properties, transparency in clear coating, adhesion, weather resistance, high gloss and excellent mechanical properties can be obtained. Can be provided.

Further, according to the water-based paint containing the fluorine-containing polymerization water-resistant dispersion of the present invention, it is possible to provide a coating film which is excellent in film formability, adhesion, weather resistance and water resistance and has high gloss. Can be.

Further, the coated article obtained by applying the water-based paint of the present invention has a coating film excellent in adhesion, weather resistance, water resistance, and glossiness, and can be used for the above many applications. .

──────────────────────────────────────────────────続 き Continuation of the front page (72) Katsuhiko Imoto 1-1, Nishiichitsuya, Settsu-shi, Osaka Daikin Industries, Ltd. Yodogawa Works (56) References JP-A-4-248821 (JP, A) JP Hei 8-170045 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 51/06 C08F 2/44 C08F 259/08 C09D 5/02 C09D 151/06

Claims (7)

(57) [Claims] An alkyl acrylate having 1 to 18 carbon atoms and / or an alkyl methacrylate having 1 to 18 carbon atoms in the presence of 100 parts by weight of particles of a fluorine-containing polymer. Ester and 20 to 100 parts by weight of a monomer mixture containing an ethylenically unsaturated monomer copolymerizable with these esters are obtained by emulsion polymerization in an aqueous medium, and the emulsion polymerization is carried out. The average particle diameter of the obtained polymer particles is 0.05 to 3
An aqueous dispersion of a fluorinated polymer having a particle size of 0.5 μm, wherein a monomer having a cyclohexyl group is contained in the ethylenically unsaturated monomer in an amount of 0.5 to 45% by weight of the monomer mixture.
And the monomer having a cyclohexyl group is acrylic
Cyclohexyl acrylate, cyclohexyl methacrylate and
Selected from the group consisting of cyclohexyl vinyl ether
Fluorine-containing polymer aqueous dispersion, wherein at least one Tanedea Rukoto. 2. The dispersion according to claim 1, wherein the fluorinated polymer is a vinylidene fluoride polymer. 3. A polymer obtained by polymerizing a monomer mixture containing 70 to 95 mol% of vinylidene fluoride and 30 to 5 mol% of chlorotrifluoroethylene. 3. The dispersion according to claim 2, wherein 4. The method according to claim 1, wherein the monomer mixture comprises the methacrylic acid
Alkyl ester and main methacrylic acid cyclohexyl and /
Or claim 1 comprising cyclohexyl vinyl ether
3. The dispersion according to any one of 3. 5. A water-based paint containing the dispersion according to claim 1. 6. A water-based paint for exterior and / or interior of a low-rise building containing the dispersion according to claim 1. Description: 7. A coated article obtained by applying the water-based paint according to claim 5 or 6.