JP6213170B2 - Fluorine-containing resin coating composition and coated article having coating film - Google Patents

Description

  The present invention relates to a fluorine-containing resin coating composition and a coated article having a coating film formed using the fluorine-containing resin coating composition.

  Conventionally, concrete products for building materials, exterior wall materials, architectural glass, guardrails, and other civil engineering members are used by being exposed to the external environment, so their surfaces are weather and chemical resistant (acid rain resistant). Fluorine-containing resin paint excellent in hot water resistance is applied.

The following are proposed as a fluorine-containing resin coating composition.
(1) A paint containing, as a paint base, an aqueous dispersion in which a fluorine-containing copolymer having a polymer unit based on a macromonomer having a hydrophilic site as an essential constituent is dispersed in water (Patent Document 1).
(2) Paint containing, as a paint base, an aqueous dispersion in which a fluorocopolymer containing a polymer unit based on fluoroolefin, a polymer unit based on propylene, a polymer unit based on ethylene, and a polymer unit based on butylene is dispersed in water (Patent Document 2).
(3) A paint comprising an aqueous solution or dispersion of a fluororesin emulsion and an acrylic copolymer (Patent Document 3).

However, although the paints of (1) and (2) are sufficiently practically usable, the film-forming property of the coating film cannot be said to be perfect, and the coating film is immersed in warm water and further stored at a low temperature. Then, there exists a problem that a coating film whitens. In particular, when a base material for ceramic building materials is used, the temperature at the time of drying of the coating film is difficult to be transmitted due to its thickness, and the problem of whitening of the coating film due to poor film forming property has been remarkable.
Also, the blocking property of the coating film was not perfect due to the poor film forming property.
On the other hand, the paint (3) can solve the problem of the film-forming property of the coating film, but has poor weather resistance and is hardly a highly weatherable fluorine-containing resin paint.

JP-A-2-225550 JP 2001-164173 A Japanese Patent Laid-Open No. 2004-250637

  The present invention relates to a fluorine-containing resin coating composition excellent in weather resistance, blocking resistance and warm water resistance of a coating film, and a coated article having a coating film excellent in weather resistance, blocking resistance and warm water resistance on the surface. I will provide a.

The fluororesin coating composition of the present invention has a fluororesin (a), a specific gravity in the range of 0.90 to 1.03, a boiling point in the range of 230 to 350 ° C., and Tg-DTA ( It is characterized by containing an ester compound (b) having a 5% weight loss temperature in the range of 150 to 250 ° C. measured at a rate of temperature rise of 10 ° C./min) and water.
The ester compound (b) is preferably at least one selected from a compound represented by the following formula (1) and a compound represented by the following formula (2).

However, in Formula (1), R < ¹ > -R < ⁵ > is a hydrogen atom or a C1-C6 alkyl group each independently, and R < ⁶ > is a C3-C15 linear or branched alkyl group. is there.

However, in the formula (2), ^{R 7} and ^{R 8} independently represents an alkylene group having 1 to 3 carbon atoms, ^{R 9} is a linear or branched alkyl group having 2 to 8 carbon atoms, n And m are each independently an integer of 1 to 3.

It is preferable that content of the said ester compound (b) is 1-15 mass parts with respect to 100 mass parts of said fluororesins (a).
The fluororesin (a) is preferably a fluororesin aqueous dispersion.

The fluororesin in the fluororesin aqueous dispersion is composed of a structural unit based on the following monomer (m1), a structural unit based on the following monomer (m2), and a structural unit based on the following monomer (m3). Or a fluorine-containing copolymer (A1 ′) having 40 to 60 mol% of the structural unit represented by the following formula (a1) and 3 to 50 mol of the structural unit represented by the following formula (a2) %, 4 to 30 mol% of the structural unit represented by the following formula (a3), and 0.4 to 7 mol% of the structural unit represented by the following formula (a4) (however, represented by the formula (a1)) The total of the structural unit represented by formula (a2), the structural unit represented by formula (a3), and the structural unit represented by formula (a4) is 80 to 100 mol%. The fluorine-containing copolymer (A2 ′) is preferable.
Monomer (m1): fluoroolefin.
Monomer (m2): a macromonomer having a hydrophilic site.
Monomer (m3): A hydroxyl group-containing monomer represented by the following formula (m3).
X'-Y'-Z '(m3)
However, X ′ is a group having a radically polymerizable unsaturated group, Y ′ is an n-nonylene group or a cyclohexane-1,4-dimethylene group, and Z ′ is a hydroxyl group.

However, ^{X 1} and ^{X 2} are each independently a hydrogen atom, a chlorine atom or a fluorine atom, ^{X 3} is a hydrogen atom, a chlorine atom, a fluorine atom or ^{-CY 1 Y 2 Y 3, Y} 1, Y 2, Y ³ is each independently a hydrogen atom, a chlorine atom or a fluorine atom.

However, ^{R a} is hydrogen atom or a methyl ^{group, R 11} is a monovalent alicyclic group of alkyl or 4 to 10 carbon atoms having 1 to 12 carbon atoms, u is an integer from 0 to 8 , V is 0 or 1.

However, ^{R b} is a hydrogen atom or a methyl ^{group, R 12} is a divalent alicyclic group alkylene or 4 to 10 carbon atoms having 1 to 10 carbon atoms, w is an integer from 0 to 8 , X is 0 or 1.

However, ^{R c} is a hydrogen atom or a methyl ^{group, R 13} is a divalent alicyclic group alkylene or 4 to 10 carbon atoms having 1 to 10 carbon ^{atoms, R 14} is 2 to 10 carbon atoms An alkylene group or a divalent alicyclic group having 4 to 10 carbon atoms, R ¹⁵ is a hydrogen atom or —NHZ ¹ Z ² Z ³ , and Z ¹ , Z ² and Z ³ are each independently a hydrogen atom, An alkyl group having 1 to 4 carbon atoms or a hydroxyalkyl group having 1 to 6 carbon atoms, at least a part of R ¹⁵ is —NHZ ¹ Z ² Z ³ , y is an integer of 0 to 8, and z is 0 or 1.

The fluorine-containing resin coating composition of the present invention preferably further contains 5 to 30 parts by mass of the silicone resin (c) with respect to 100 parts by mass of the fluorine-containing resin (a).
The coated article of the present invention has a coating film formed using the fluororesin coating composition of the present invention.

According to the fluorine-containing resin coating composition of the present invention, a coating film excellent in weather resistance, blocking resistance and hot water resistance can be formed.
The coated article of the present invention has a coating film excellent in weather resistance, blocking resistance, and hot water resistance.

In the present specification, a compound represented by the formula (1) is referred to as a compound (1). The same applies to compounds represented by other formulas.
The following definitions of terms apply throughout this specification and the claims.
“Structural unit” means a unit derived from a monomer formed by polymerization of the monomer. It may be a unit directly formed by a polymerization reaction, or may be a unit in which a part of the unit is converted into another structure by treating the polymer.
“Monomer” means a compound having a radically polymerizable unsaturated group.
“(Meth) acrylate” means either or both of acrylate and methacrylate.
“Aqueous medium” means a liquid containing water and having an organic solvent content of 3% by mass or less.
The “macromonomer” means a low molecular weight polymer or oligomer having a radical polymerizable unsaturated group at one end.
The “hydrophilic part” means a part having a hydrophilic group, a part having a hydrophilic bond, or a part composed of a combination thereof.

<Fluorine-containing resin coating composition>
The fluorine-containing resin coating composition of the present invention has a fluorine resin (a), a specific gravity in the range of 0.90 to 1.03, a boiling point in the range of 230 to 350 ° C., and Tg-DTA (increased). 5% weight loss temperature measured at a temperature rate of 10 ° C./minute) is an ester compound (b) in the range of 150 to 250 ° C. and water.
The fluorine-containing resin coating composition of the present invention includes, for example, a fluorine-containing resin (a), a specific gravity in the range of 0.90 to 1.03, a boiling point in the range of 230 to 350 ° C., and Tg-DTA. It is obtained by blending an ester compound (b) having a 5% weight loss temperature in the range of 150 to 250 ° C. measured at a rate of temperature increase of 10 ° C./min and water.

(Ester compound (b))
The ester compound (b) is at least one selected from the compound (1) and the compound (2).

However, in Formula (1), R < ¹ > -R < ⁵ > is a hydrogen atom or a C1-C6 alkyl group each independently, and R < ⁶ > is a C3-C15 linear or branched alkyl group. It is.

However, in the formula (2), ^{R 7} and ^{R 8} independently represents an alkylene group having 1 to 3 carbon atoms, ^{R 9} is a linear or branched alkyl group having 2 to 8 carbon atoms, n And m are each independently an integer of 1 to 3.

The molecular weight of the compound (1) and the compound (2) is preferably 100 to 1000, more preferably 120 to 800, and still more preferably 150 to 500. When the molecular weight is at least the lower limit value, the coating film is less likely to volatilize during drying and curing, and the film-forming property of the coating film is improved. If the said molecular weight is below an upper limit, the blocking property of a coating film will become favorable.
The molecular weights of the compound (1) and the compound (2) can be calculated from a chemical structural formula by NMR analysis.

  Preferable examples of the compound (1) include ethyl benzoate, butyl benzoate, 2-ethylhexyl benzoate and the like. For example, as a commercial product, SDX-3652 (trade name, manufactured by ADEKA Corporation, benzoic acid 2- Ethylhexyl) can be used.

  Preferred examples of the compound (2) include diester compounds of dibasic acids such as diethoxyethyl succinate, dibutoxyethyl succinate and dibutoxyethyl adipate. For example, SDX-3789 is a commercially available product. (Trade name, manufactured by ADEKA, dibutoxyethyl adipate) can be used.

The content of the ester compound (b) is preferably 1.0 to 30.0 parts by mass, and 2.0 to 20.0 parts by mass with respect to 100 parts by mass of the fluororesin (a). More preferably, it is more preferably 3.0 to 15.0 parts by mass.
If the said content is more than a lower limit, the film forming property of a coating film will become favorable and whitening of a coating film can be suppressed. If the said content is below an upper limit, there will be little residual amount in a coating film, and the blocking property of a coating film will become favorable.

(Fluorine-containing resin (a))
The fluorine-containing resin (a) is obtained by dispersing or dissolving a fluorine-containing polymer in an aqueous medium.
Examples of the fluorinated polymer include a polymer having a structural unit based on a fluorinated monomer, or a structural unit based on a fluorinated monomer and another monomer copolymerizable with the fluorinated monomer. And a polymer having a structural unit based thereon.

Examples of fluorine-containing monomers include fluoroolefins (vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, pentafluoroethylene, hexafluoropropylene, etc.), fluorine-containing (meth) acrylates (trifluoroethyl). (Meth) acrylate, pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, etc.).
Of these, fluoroolefins are preferable as the fluorine-containing monomer, and among the fluoroolefins, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, and chlorotrifluoroethylene are more preferable.
Examples of other monomers copolymerizable with the fluorine-containing monomer include acrylic monomers, other monomers copolymerizable with acrylic monomers, and the like.

  As the fluorine-containing resin (a), a fluorine-containing resin water dispersion (A1), a fluorine-containing resin water dispersion (A2) or a fluorine-containing resin water dispersion (A3), which will be described later, is preferable, and the coating film is difficult to crack. From this point, the fluorine-containing resin water dispersion (A1) or the fluorine-containing resin water dispersion (A2) is more preferable.

  Examples of the method for producing a fluororesin aqueous dispersion include a method of obtaining a fluororesin aqueous dispersion by emulsion polymerization, and obtaining a fluorocopolymer by solution polymerization, and then dispersing the fluorocopolymer in an aqueous medium. And a method of obtaining an aqueous dispersion of a fluororesin.

The emulsion polymerization may be performed by batch polymerization, monomer dropping polymerization, or emulsion monomer dropping polymerization.
Examples of the emulsifier used for emulsion polymerization include an anionic emulsifier, a cationic emulsifier, a nonionic emulsifier, an amphoteric emulsifier, a nonionic-cationic emulsifier, and a nonionic-anionic emulsifier. For the purpose of improving water resistance, an emulsifier having a reactive group may be used. An emulsifier may be used individually by 1 type and may use 2 or more types together.

Examples of the polymerization initiator used in the emulsion polymerization include known radical initiators. Specifically, a persulfate (ammonium persulfate, etc.), a redox initiator (a combination of hydrogen peroxide and sodium hydrogensulfite, etc.) ), Inorganic initiators (ferrous salts, silver nitrate, etc.), dibasic acid peroxides (disuccinic acid peroxide, diglutaric acid peroxide, etc.), organic initiators (azobisbutyronitrile) Etc.).
The amount of the polymerization initiator is, for example, about 0.01 to 5 parts by mass with respect to 100 parts by mass of the monomer.

  During emulsion polymerization, inorganic salts (sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, sodium thiosulfate, etc.) and organic bases (triethylamine, triethanolamine, etc.) are used to adjust the pH of the emulsion. It may be added.

  When the fluorine-containing copolymer obtained by solution polymerization is used after being dispersed in water, the remaining organic solvent may be distilled off. In order to enhance water dispersibility, a hydrophilic group may be introduced into the fluorine-containing copolymer obtained by solution polymerization, and an emulsifier may be used during solution polymerization.

(Fluorine-containing resin water dispersion (A1))
The fluororesin aqueous dispersion (A1) is obtained by dispersing or dissolving a synthetic resin containing a fluorocopolymer (A1 ′) in an aqueous medium.
The fluorine-containing copolymer (A1 ′) has a structural unit based on the monomer (m1), a structural unit based on the monomer (m2), and a structural unit based on the monomer (m3).

Monomer (m1):
The monomer (m1) is a fluoroolefin.
Examples of the fluoroolefin include vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, pentafluoropropylene, hexafluoropropylene and the like.
As a fluoroolefin, a C2-C4 fluoroolefin is preferable and a perhalo olefin is especially preferable.

Monomer (m2):
The monomer (m2) is a macromonomer having a hydrophilic part.
The monomer (m2) has two or more structural units in the main chain, a radically polymerizable unsaturated group at one end, and a hydrophilic portion at the remaining end, pendant group or main chain. Compounds. The number of structural units varies depending on the type of structural unit, but is usually preferably 100 or less from the viewpoint of polymerizability, water resistance and the like.

  In the fluororesin aqueous dispersion (A1), it is important that the fluorocopolymer (A1 ′) has a structural unit based on the monomer (m2). By including the fluorine-containing copolymer (A1 ′) having a structural unit based on the monomer (m2), the fluorine-containing resin water dispersion (A1) is a mechanical component of the fluorine-containing resin water dispersion (A1). Not only the chemical stability is improved, but also the film forming property of the fluororesin aqueous dispersion (A1), the water resistance of the coating film, and the like are improved.

  The hydrophilic group constituting the hydrophilic portion may be any of ionic, nonionic, amphoteric and a combination thereof. From the viewpoint of the chemical stability of the fluororesin aqueous dispersion (A1), the portion having an ionic hydrophilic group and the nonionic property or the hydrophilic portion only from the portion having an ionic hydrophilic group, or It is preferable to combine with a site having an amphoteric hydrophilic group, or to combine a site having an ionic hydrophilic group and a site having a hydrophilic bond.

Examples of the monomer (m2) include the following macromonomers.
Monomer (m21): a macromonomer having a polyether chain or a polyester chain in the main chain and a radically polymerizable unsaturated group at one end.
Monomer (m22): a macromonomer having a chain obtained by radical polymerization of a hydrophilic ethylenically unsaturated monomer and having a radically polymerizable unsaturated group (vinyloxy group or allyloxy group) at one end.

As a monomer (m21), the following are mentioned, for example.
_{(1) CH 2 = CHO-} C a H 2a - (OC b H 2b) c OX "
However, a is an integer of 1-10, b is an integer of 1-4, c is an integer of 2-20, X "is a hydrogen atom or a C1-C10 alkyl group (henceforth lower). This will be referred to as an alkyl group.).
_{(2) CH 2 = CHCH 2} OC d H 2d - (OC e H 2e) f OX "
However, d is an integer of 1-10, e is an integer of 1-4, f is an integer of 2-20, and X "is a hydrogen atom or a lower alkyl group.
_{(3) CH 2 = CHO-} C g H 2g - (OCH 2 CH 2) h (OCH 2 CH (CH 3)) i OX "
However, g is an integer of 1-10, h is an integer of 2-20, i is an integer of 0-20, X "is a hydrogen atom or a lower alkyl group, an oxyethylene unit and an oxypropylene The unit may be arranged in either block or random form.
_{(4) CH 2 = CHCH 2} O-C j H 2j - (OCH 2 CH 2) k (OCH 2 CH (CH 3)) l OX "
However, j is an integer of 1-10, k is an integer of 2-20, l is an integer of 0-20, X "is a hydrogen atom or a lower alkyl group, an oxyethylene unit and an oxypropylene The unit may be arranged in either block or random form.
_{(5) CH 2 = CHO-} C p H 2p -O (CO-C q H 2q -O) r H
However, p is an integer of 1-10, q is an integer of 1-10, r is an integer of 1-30.
_{(6) CH 2 = CHOCH 2} -cycloC 6 H 10 -CH 2 (OC s H 2s) t OX "
However, s is an integer of 1-4, t is an integer of 2-20, and X "is a hydrogen atom or a lower alkyl group.

As the monomer (m21), one having a vinyl ether type structure at one end is preferable from the viewpoint of excellent copolymerizability with the monomer (m1), and from the viewpoint of excellent hydrophilicity, Particularly preferred are those in which the ether chain portion is composed of oxyethylene units, or composed of oxyethylene units and oxypropylene units.
The monomer (m21) is preferably one having two or more oxyethylene units from the viewpoint of sufficiently exhibiting various properties such as stability. In addition, when there are too many oxyalkylene units, there exists a possibility that the water resistance of a coating film, a weather resistance, etc. may fall.

  The monomer (m21) can be produced by a method of polymerizing formaldehyde or diol with a vinyl ether or allyl ether having a hydroxyl group, or a method of ring-opening polymerization of a compound having an alkylene oxide or a lactone ring.

A monomer (m22) can be manufactured by the following method, for example.
A polymer having a condensable functional group can be produced by radical polymerization of an ethylenically unsaturated monomer having a hydrophilic group in the presence of an initiator having a condensable functional group and a chain transfer agent. A method in which a functional group is reacted with glycidyl vinyl ether, glycidyl allyl ether or the like to introduce a radical polymerizable unsaturated group at the terminal (Yamashita et al., Polym. Bull., 5.335 (1981)).

  Examples of the ethylenically unsaturated monomer having a hydrophilic group include acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, 2-methoxyethyl acrylate, 2-methoxyethyl methacrylate, diacetone acrylamide, hydroxyethyl acrylate, hydroxy Examples include propyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, polyhydric alcohol acrylate, polyhydric alcohol methacrylate, and vinylpyrrolidone.

Examples of other monomers copolymerizable with the ethylenically unsaturated monomer having a hydrophilic group include acrylamide derivatives, methacrylamide derivatives, N-methylolacrylamide derivatives, ethyl carbitol acrylate, butoxyethyl acrylate, and the like.
Examples of the initiator having a condensable functional group include 4,4′-azobis-4-cyanovaleric acid, 2,2′-azobis-2-amidinopropane hydrochloride, potassium persulfate, ammonium persulfate, azobisisobutyrate. Examples include rhonitrile, benzoyl peroxide, and the like.

Monomer (m3):
The monomer (m3) is a hydroxyl group-containing monomer represented by the following formula (m3).
X'-Y'-Z '(m3)
However, X ′ is a group having a radically polymerizable unsaturated group, Y ′ is an n-nonylene group or a cyclohexane-1,4-dimethylene group, and Z ′ is a hydroxyl group.

  In the fluororesin aqueous dispersion (A1), it is important that the fluorocopolymer (A1 ′) has a structural unit based on the monomer (m3). When the fluorine-containing copolymer (A1 ′) has a structural unit based on a hydroxyl group-containing monomer other than the monomer (m3), the fluorine-containing copolymer (A1 ′) is produced, stored, or coated. The fluorine-containing copolymer (A1 ′) may aggregate.

  X ′ has a radically polymerizable unsaturated group and, if necessary, a linking group for linking the radically polymerizable unsaturated group and Y ′. Examples of the radical polymerizable unsaturated group include a vinyl group, an allyl group, a propenyl group, an isopropenyl group, an acryloyl group, and a methacryloyl group. As the linking group, an ether bond is preferable.

Examples of the monomer (m3) include the following.
_{(1) CH 2 = CHOCH 2} -cycloC 6 H 10 -CH 2 OH
_{(2) CH 2 = CHCH 2} OCH 2 -cycloC 6 H 10 -CH 2 OH
(3) CH ₂ = CHOC ₉ H ₁₈ OH
(4) CH ₂ = CHCH ₂ OC ₉ H ₁₈ OH

  As the monomer (m3), a monomer having a vinyl ether structure is preferable from the viewpoint of excellent alternating copolymerization with the monomer (m1) and good weather resistance of the coating film.

Monomer (m4):
In addition to the monomers (m1) to (m3), the fluorinated copolymer (A1 ′) has structural units based on other monomers (monomer (m4)) copolymerizable therewith. You may do it.
Monomers (m4) include olefins (ethylene, propylene, etc.), vinyl ethers (ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, cyclohexyl vinyl ether, 2-ethylhexyl vinyl ether, etc.), vinyl esters (butanoic acid vinyl ester, octanoic acid vinyl ester). Etc.), aromatic vinyl compounds (such as styrene and vinyl toluene), allyl compounds (such as ethyl allyl ether), acryloyl compounds (such as butyl acrylate), and methacryloyl compounds (such as ethyl methacrylate).

As the monomer (m4), olefin, vinyl ether, vinyl ester, allyl ether, and allyl ester are preferable.
As the olefin, an olefin having 2 to 10 carbon atoms is preferable.
As vinyl ethers, vinyl esters, allyl ethers, and allyl esters, those having a linear, branched or alicyclic alkyl group having 2 to 15 carbon atoms are preferred.
The monomer (m4) may be one in which at least a part of hydrogen atoms bonded to carbon atoms is substituted with fluorine atoms.

Composition unit ratio:
The proportion of the structural unit based on the monomer (m1) is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, among all the structural units. When the structural unit based on the monomer (m1) is 20 mol% or more, the weather resistance is sufficiently exhibited. If the structural unit based on the monomer (m1) is 80 mol% or less, the water-dispersibility of the fluorinated copolymer (A1 ′) will be good.

  The proportion of the structural unit based on the monomer (m2) is preferably from 0.1 to 25 mol%, more preferably from 0.3 to 20 mol%, among all the structural units. If the structural unit based on the monomer (m2) is 0.1 mol% or more, the water-dispersibility of the fluorinated copolymer (A1 ') will be good. If the structural unit based on the monomer (m2) is 25 mol% or less, the weather resistance and water resistance of the coating film will be good. When the proportion of the structural unit based on the monomer (m2) is within the above range, the film forming property is extremely excellent.

As for the ratio of the structural unit based on a monomer (m3), 1-40 mol% is preferable among all the structural units.
The proportion of the structural unit based on the monomer (m3) is preferably such that the hydroxyl value of the fluorinated copolymer (A1 ′) is 20 mgKOH / g or more, such that it is 40 mgKOH / g or more. A ratio is more preferable. When the hydroxyl value of the fluorinated copolymer (A1 ′) is 20 mgKOH / g or more, the solvent resistance of the coating film is remarkably improved by the reaction with the curing agent.

Production of fluororesin aqueous dispersion (A1):
The fluororesin aqueous dispersion (A1) is produced by emulsion polymerization.
Although a fluororesin aqueous dispersion (A1) having good dispersion stability can be obtained without using an emulsifier, it is preferable to use an emulsifier. Nonionic emulsifiers include alkylphenol ethylene oxide adducts, higher alcohol ethylene oxide adducts, block copolymers of ethylene oxide and propylene oxide, and the like. Examples of the anionic emulsifier include alkyl benzene sulfonate, alkyl naphthalene sulfonate, higher fatty acid salt, alkyl sulfate ester salt, alkyl ether sulfate ester salt, and phosphate ester salt.

The start of emulsion polymerization is performed by adding a polymerization initiator in the same manner as the start of normal emulsion polymerization.
As a polymerization initiator, a well-known radical initiator is mentioned, A water-soluble initiator is preferable. Specifically, persulfates (such as ammonium persulfate), redox initiators (such as a combination of hydrogen peroxide and a reducing agent (sodium bisulfite, sodium thiosulfate, etc.)), inorganic initiators (iron, Ferrous salt, silver sulfate, etc. coexisting system, dibasic acid peroxide (disuccinic acid peroxide, diglutaric acid peroxide, etc.), organic initiator (azobisisobutylamidine hydrochloride, azobisisobutyronitrile) Etc.).
The quantity of a polymerization initiator can be suitably changed according to the kind, emulsion polymerization conditions, etc., and is about 0.005-0.5 mass part normally with respect to 100 mass parts of monomers.
The polymerization initiator may be added all at once or in divided portions.

A pH adjuster may be used for the purpose of increasing the pH of the emulsion. Examples of pH adjusters include inorganic bases (sodium carbonate, potassium carbonate, sodium hydrogen orthophosphate, sodium thiosulfate, sodium tetraborate, etc.), organic bases (triethylamine, triethanolamine, dimethylethanolamine, diethylethanolamine, etc.), etc. Can be mentioned.
The amount of the pH adjuster is usually about 0.05 to 2 parts by mass and preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the aqueous medium used for emulsion polymerization. The higher the pH of the emulsion, the higher the polymerization rate tends to be.

The optimum temperature for the emulsion polymerization is appropriately selected according to the type of the polymerization initiator, and is usually about 0 to 100 ° C, preferably 10 to 90 ° C.
The pressure at the time of emulsion polymerization can be selected as appropriate, and is usually about 0.1 to 10 MPa, preferably 0.2 to 5 MPa.

  In emulsion polymerization, a monomer, an aqueous medium, an emulsifier, a polymerization initiator, etc. may be charged all at once, and polymerization may be carried out. The particle size of the fluorine-containing copolymer (A1 ′) is reduced to obtain a fluorine-containing resin. For the purpose of improving various properties such as the stability of the aqueous dispersion (A1) and the gloss of the coating film, pre-emulsification is performed using a stirrer such as a homogenizer before adding the polymerization initiator, and then the polymerization initiator is added. It may be added and polymerized. The monomer may be added in portions or continuously. When adding in divided or continuous, the monomer composition may be changed.

(Fluoropolymer aqueous dispersion (A2))
The fluororesin aqueous dispersion (A2) is obtained by dispersing or dissolving a synthetic resin containing a fluorocopolymer (A2 ′) in an aqueous medium (preferably water).
The fluorine-containing copolymer (A2 ′) has a structural unit (a1), a structural unit (a2), a structural unit (a3), and a structural unit (a4).
As the fluororesin aqueous dispersion (A2), as described later, a carboxy group is introduced into the fluorocopolymer (B) obtained by the solution polymerization method, and the carboxy group is neutralized with a basic compound. Those obtained by dispersing in water are preferred.

Structural unit (a1):
The structural unit (a1) is a structural unit based on a fluoroolefin compound represented by the following formula (a1).

However, ^{X 1} and ^{X 2} are each independently a hydrogen atom, a chlorine atom or a fluorine atom, ^{X 3} is a hydrogen atom, a chlorine atom, a fluorine atom or ^{-CY 1 Y 2 Y 3, Y} 1, Y 2, Y ³ is each independently a hydrogen atom, a chlorine atom or a fluorine atom.

Examples of the fluoroolefin compound include fluoroethylene and fluoropropene.
As fluoroethylene, CF ₂ = CF ₂ , CClF = CF ₂ , CHCl = CF ₂ , CCl ₂ = CF ₂ , CClF = CClF, CHF = CCl ₂ , CH ₂ = CClF, CCl ₂ = CClF, CF ₂ = CH ₂ etc. are mentioned.
The _{fluoropropene, CF 2 ClCF = CF 2,} CF 3 CCl = CF 2, CF 3 CF = CFCl, CF 2 ClCCl = CF 2, CF 2 ClCF = CFCl, CFCl 2 CF = CF 2, CF 3 CCl = CClF , include _{CF 3 CCl = CCl 2, CClF} 2 CF = CCl 2, CCl 3 CF = CF 2, CF 2 ClCCl = CCl 2, CFCl 2 CCl = CCl 2, CF 3 CF = CHCl, CClF 2 CF = CHCl etc. It is done.
As the fluoroolefin compound, CF ₂ = CF ₂ and CClF = CF ₂ are preferable from the viewpoint of excellent weather resistance of the coating film.

Structural unit (a2):
The structural unit (a2) is a structural unit based on an alkyl vinyl ether, an alkyl vinyl ester, an alkyl allyl ether, an alkyl allyl ester, or the like represented by the following formula (a2). Among these, a constitutional unit corresponding to desired film properties (hardness, gloss, pigment dispersibility, etc.) is appropriately selected. The fluorine-containing copolymer (A2 ′) may have two or more structural units (a2).

However, ^{R a} is hydrogen atom or a methyl ^{group, R 11} is a monovalent alicyclic group of alkyl or 4 to 10 carbon atoms having 1 to 12 carbon atoms, u is an integer from 0 to 8 , V is 0 or 1.

As the structural unit (a2), structural units based on alkyl vinyl ethers or alkyl vinyl esters in which u is 0 and v is 0 or 1 are preferred. Examples of the alkyl vinyl ether or alkyl vinyl ester include ethyl vinyl ether, n-butyl vinyl ether, cyclohexyl vinyl ether, vinyl acetate, vinyl valerate, and vinyl pivalate.
As the structural unit (a2), ethyl vinyl ether and cyclohexyl vinyl ether are preferable from the viewpoint of good alternating copolymerization with the structural unit (a1) and easy adjustment of the glass transition temperature of the fluorinated copolymer (A2 ′).

Structural unit (a3):
The structural unit (a3) is a structural unit based on a hydroxyl group-containing vinyl ether, a hydroxyl group-containing vinyl ester, a hydroxyl group-containing allyl ether, a hydroxyl group-containing allyl ester, or the like represented by the following formula (a3).

However, ^{R b} is a hydrogen atom or a methyl ^{group, R 12} is a divalent alicyclic group alkylene or 4 to 10 carbon atoms having 1 to 10 carbon atoms, w is an integer from 0 to 8 , X is 0 or 1.

Examples of the structural unit (a3) include structural units based on 2-hydroxyalkyl vinyl ether, 4-hydroxybutyl vinyl ether, 1-hydroxymethyl-4-vinyloxymethylcyclohexane, or 4-hydroxyptyl vinyl ester.
As the structural unit (a3), a structural unit based on hydroxyalkyl vinyl ether is preferable from the viewpoints of polymerizability and crosslinkability.

Structural unit (a4):
The structural unit (a4) is a structural unit represented by the following formula (a4).

However, ^{R c} is a hydrogen atom or a methyl ^{group, R 13} is a divalent alicyclic group alkylene or 4 to 10 carbon atoms having 1 to 10 carbon ^{atoms, R 14} is 2 to 10 carbon atoms An alkylene group or a divalent alicyclic group having 4 to 10 carbon atoms, R ¹⁵ is a hydrogen atom or —NHZ ¹ Z ² Z ³ , and Z ¹ , Z ² and Z ³ are each independently a hydrogen atom, An alkyl group having 1 to 4 carbon atoms or a hydroxyalkyl group having 1 to 6 carbon atoms, at least a part of R ¹⁵ is —NHZ ¹ Z ² Z ³ , y is an integer of 0 to 8, and z is 0 or 1.
In R ¹⁵ , the proportion of —NHZ ¹ Z ² Z ³ is preferably 30 to 100 mol%, and more preferably 50 to 100 mol%.
R ^c , R ¹³ , y and z are the same as R ^b , R ¹² , w and x in the structural unit (a3) from the viewpoint of easy production of the fluorinated copolymer (A2 ′). Is preferred.

Other structural units:
The fluorine-containing copolymer (A2 ′) may have other structural units other than the structural units (a1) to (a4).
Examples of other structural units include structural units based on ethylenic monomers.

Composition unit ratio:
The ratio of a structural unit (a1) is 40-60 mol% among all the structural units, and 45-55 mol% is preferable. When the proportion of the structural unit (a1) is within the above range, the weather resistance of the coating film is sufficient, the glass transition temperature of the fluorinated copolymer (A2 ′) is not excessively high, and is amorphous and good. A coating film is obtained.

  The ratio of a structural unit (a2) is 3-50 mol% among all the structural units, and 20-45 mol% is preferable. When the proportion of the structural unit (a2) is within the above range, it is easy to disperse in water, and the fluorinated copolymer does not easily settle during storage.

  The ratio of the structural unit (a3) is 4 to 30 mol%, preferably 8 to 25 mol%, among all the structural units. When the proportion of the structural unit (a3) is 4 mol% or more, the crosslinking density is sufficiently high when crosslinking is performed. If the ratio of a structural unit (a3) is 30 mol% or less, the fall of water resistance when it is set as a coating film will be suppressed.

  The ratio of the structural unit (a4) is 0.4 to 7 mol%, preferably 1.4 to 6 mol%, among all the structural units. When the proportion of the structural unit (a4) is within the above range, the dispersibility in the aqueous medium is excellent, and the stability in the aqueous medium is excellent.

The sum total of the structural units (a1) to (a4) is 80 to 100 mol%, preferably 95 to 100 mol%.
The proportion of other structural units is 20 mol% or less, preferably 5 mol% or less.

  The fluorine-containing copolymer (A2 ′) includes 45 to 55 mol% of the structural unit (a1), 14 to 45.6 mol% of the structural unit (a2), and 8 to 25 mol of the structural unit (a3). % And 1.4 to 6 mol% of the structural unit (a4), and those having no other structural unit are preferable.

Production of fluororesin aqueous dispersion (A2):
The fluororesin aqueous dispersion (A2) can be produced by a method having steps (α) to (δ).
(Α) A step of producing the fluorine-containing copolymer (B).
(Β) A step of esterifying a part of hydroxyl groups in the structural unit (a3) by introducing a carboxy group by reacting the fluorinated copolymer (B) with a dibasic acid anhydride in an organic solvent.
(Γ) A step of neutralizing at least a part of the carboxy group introduced by the esterification reaction with a basic compound.
(Δ) A step of removing the organic solvent.

Step (α):
The fluorine-containing copolymer (B) is 40 to 60 mol% of the structural unit (a1), 3 to 50 mol% of the structural unit (a2), and 4.4 to 37 mol% of the structural unit (a3) ( However, the total of the structural units (a1) to (a3) is 80 to 100 mol%.
The mole% of the structural unit (a3) in the fluorinated copolymer (B) is equal to the sum of the mole% of the structural unit (a3) and the mole% of the structural unit (a4) in the fluorinated copolymer (A2 ′). .

  The fluorine-containing copolymer (B) comprises a monomer (b1), a monomer (b2), and a monomer (b3) in the presence or absence of a polymerization catalyst, a polymerization initiator, ionizing radiation. It can manufacture by making superposition | polymerization start sources, such as act, and superposing | polymerizing on alkaline conditions. In order to keep the copolymerization reaction system on the alkali side, the polymerization reaction is carried out in the presence of a basic compound.

  The monomer (b1) is a compound represented by the following formula (b1).

However, ^{X 1} and ^{X 2} are each independently a hydrogen atom, a chlorine atom or a fluorine atom, ^{X 3} is a hydrogen atom, a chlorine atom, a fluorine atom or ^{-CY 1 Y 2 Y 3, Y} 1, Y 2, Y ³ is each independently a hydrogen atom, a chlorine atom or a fluorine atom.

  The monomer (b2) is a monomer represented by the following formula (b2).

However, ^{R a} is hydrogen atom or a methyl ^{group, R 11} is a monovalent alicyclic group of alkyl or 4 to 10 carbon atoms having 1 to 12 carbon atoms, u is an integer from 0 to 8 , V is 0 or 1.

  The monomer (b3) is a compound represented by the following formula (b3).

However, ^{R b} is a hydrogen atom or a methyl ^{group, R 12} is a divalent alicyclic group alkylene or 4 to 10 carbon atoms having 1 to 10 carbon atoms, w is an integer from 0 to 8 , X is 0 or 1.

  The proportion (mol%) of the monomer (b1), monomer (b2), and monomer (b3) charged is the structural unit (a1) or structural unit (B) constituting the fluorinated copolymer (B). a2) and the mol% of the structural unit (a3).

Examples of the polymerization initiator include peroxy ester type peroxides (such as t-butyl peroxyacetate), dialkyl peroxydicarbonates (such as diisopropyl peroxydicarbonate), benzoyl peroxide, azobisisobutyronitrile and the like.
The quantity of a polymerization initiator can be suitably changed according to the kind and polymerization reaction conditions, and is about 0.05-0.5 mass part normally with respect to 100 mass parts of monomers.

Examples of the basic compound include organic basic compounds and inorganic basic compounds. Examples of the organic basic compound include alkylamine (such as triethylamine) and alkylphosphine (such as triethylphosphine). Inorganic basic compounds include alkali metal or alkaline earth metal carbonates (potassium carbonate, etc.), alkali metal or alkaline earth metal hydroxides (potassium hydroxide, sodium hydroxide, etc.), alkali metals or alkaline earths. Metal oxides (magnesium oxide, etc.).
0.01-20 mass% is preferable with respect to 100 mass parts of monomers, and, as for the quantity of a basic compound, 0.1-10 mass% is more preferable.

As the polymerization method, a solution polymerization method is preferable. Examples of the organic solvent include alcohols, esters, ketones, saturated halogenated hydrocarbons having one or more fluorine atoms, and aromatic hydrocarbons (such as xylene).
The temperature during solution polymerization is preferably 10 to 90 ° C.
The pressure during solution polymerization is preferably 0 to 2 MPa, more preferably 0 to 1 MPa.

  As for the mass mean molecular weight of a fluorine-containing copolymer (B), 3000-200000 are preferable. When the mass average molecular weight of the fluorinated copolymer (B) is 3000 or more, the weather resistance when formed into a coating film is good. If the mass average molecular weight of a fluorine-containing copolymer (B) is 200000 or less, paintability will become favorable and a coating-film external appearance will become favorable.

Step (β):
By reacting the fluorinated copolymer (B) and the dibasic acid anhydride in an organic solvent, a part of the hydroxyl group in the structural unit (a3) is esterified to introduce a carboxy group.
Dibasic acid anhydrides include succinic anhydride, glutaric anhydride, itaconic anhydride, adipic anhydride, 1,2-cyclohexanedicarboxylic anhydride, cis-4-cyclohexene-1,2-dicarboxylic anhydride, phthalic anhydride Examples include acid, 1,8-naphthalic anhydride, and maleic anhydride.

As an organic solvent, alcohol (methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, secondary butanol, tertiary butanol, pentanol, etc.), cellosolve (methyl cellosolve, ethyl cellosolve, isopropyl cellosolve, Butyl cellosolve, secondary butyl cellosolve, etc.), propylene glycol derivatives (propylene glycol methyl ether, dipropylene glycol methyl ether, propylene glycol methyl ether acetate, etc.), ethylene glycol ethyl ether acetate, ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), Aromatic hydrocarbons (toluene, xylene, etc.) etc. are mentioned.
The organic solvent is appropriately selected in consideration of the solubility of the fluoropolymer (B) and the dibasic acid anhydride. If the organic solvent used in the step (α) remains sufficiently, there is no need to add a new organic solvent in the step (β).

In the step (β), a catalyst may be used in combination. Examples of the catalyst include carboxylic acid metal salts, alkali hydroxides, alkali metal carbonates, quaternary ammonium salts, tertiary amines and the like, and tertiary amines (triethylamine and the like) are preferable.
The temperature of the esterification reaction is preferably room temperature to 150 ° C, more preferably 50 to 100 ° C. The time for the esterification reaction is about several tens of minutes to several hours.

The amount of the dibasic acid anhydride is such that the proportion of the structural unit (a4) in the resulting fluorinated copolymer (A2 ′) is 0.4 to 7 mol%, and the proportion of the structural unit (a3). Is adjusted so that 4 to 30 mol% remains.
The proportion of the structural unit (a4) after the esterification reaction can be confirmed by measuring the acid value. If the acid value after esterification reaction is 2-35 mgKOH / g, it can confirm that a structural unit (a4) is 0.4-7 mol%.
The proportion of the structural unit (a3) before the esterification reaction can be confirmed from the hydroxyl value before the esterification reaction. For the proportion of the structural unit (a3) to be 4 to 30 mol, the hydroxyl value before the esterification reaction is 20 to 150 mgKOH / g, and the acid value after the esterification reaction is within the above range. is necessary.

Step (γ):
A basic compound is added to the fluorine-containing copolymer (B) obtained in the step (β), and at least a part of the carboxy group introduced in the step (β) is neutralized with the basic compound.
30-100 mol% is preferable and, as for the ratio neutralized with a basic compound among structural units (a4), 50-100 mol% is more preferable.
In the neutralization reaction, a basic compound or an aqueous solution of a basic compound is added to the organic solvent in which the fluorine-containing copolymer (B) obtained in step (β) is dissolved with stirring for several tens of minutes at room temperature. If it is, it will proceed sufficiently.

As the basic compound, those having a boiling point of 200 ° C. or less are preferable from the viewpoint that the basic compound hardly remains in the coating film.
Basic compounds having a boiling point of 200 ° C. or less include ammonia and alkylamines (monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, monoisopropylamine, diisopropylamine, triisopropylamine, monobutylamine, dibutylamine, etc.) , Alkanolamine (monoethanolamine, monoisopropanolamine, dimethylaminoethanol, diethylaminoethanol, etc.), diamine (ethylenediamine, propylenediamine, tetramethylenediamine, hexamethylenediamine, etc.), alkyleneimine (ethyleneimine, propyleneimine, etc.), piperazine , Morpholine, pyrazine, pyridine and the like.

In the step (γ), water may be added to the organic solvent in which the fluorine-containing copolymer (B) obtained in the step (β) is dissolved. Water may be added simultaneously with the basic compound, may be added separately from the basic compound, a part may be added simultaneously with the basic compound, and the remainder may be added separately from the basic compound. When adding a part or all together with a basic compound, it is preferable to make it the aqueous solution of a basic compound. When adding separately from a basic compound, water may be added before adding a basic compound, and water may be added after adding a basic compound. Among these, a method of adding water after adding the basic compound and a method of adding an aqueous solution of the basic compound are preferable.
The amount of water is preferably such that the solid concentration of the aqueous dispersion obtained in the step (γ) is 20 to 70% by mass, and more preferably 30 to 60% by mass.

Step (δ):
After the step (γ), the organic solvent is removed. Thereby, the fluororesin water dispersion (A2) whose organic solvent is 10 mass% or less with respect to the total mass is obtained. It is preferable to remove all organic solvents.
Examples of the organic solvent to be removed include those in which the organic solvent used in the step (α) remains and those in which the organic solvent used in the step (β) remains.
The removal of the organic solvent can be performed by distillation under reduced pressure.
When a necessary amount of water is not added in the step (γ), water may be added after removing the organic solvent.
The amount of water is preferably such that the solid content concentration of the aqueous dispersion obtained in step (δ) is 20 to 70% by mass, and more preferably 30 to 60% by mass.

(Fluorine-containing resin water dispersion (A3))
The fluororesin aqueous dispersion (A3) is obtained by dispersing or dissolving a resin containing a fluoropolymer (A3 ′) in an aqueous medium.
The fluorine-containing polymer (A3 ′) has a structural unit based on at least one fluorine-containing monomer selected from the group consisting of vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, and chlorotrifluoroethylene.
The fluorinated polymer (A3 ′) is another monomer copolymerizable with the fluorinated monomer (for example, acrylic monomer, other monomer copolymerizable with the acrylic monomer, etc.) ) May be included.

The fluorinated resin aqueous dispersion (A3) preferably contains an acrylic resin as a synthetic resin other than the fluorinated polymer (A3 ′) from the viewpoint of film-forming properties of the coating film and adhesion to the substrate. .
The acrylic resin preferably has a structural unit based on at least one acrylic monomer selected from the group consisting of acrylic acid, acrylic acid ester, methacrylic acid and methacrylic acid ester.
As the acrylic ester, an alkyl alkyl ester having 1 to 10 carbon atoms in the alkyl group is preferable in that a coating film having excellent transparency and film-forming property can be obtained.
As the methacrylic acid ester, a methacrylic acid alkyl ester having 1 to 10 carbon atoms in the alkyl group is preferable in that a coating film having excellent transparency and film-forming property can be obtained.

The fluororesin aqueous dispersion (A3) containing an acrylic resin can be prepared by mixing a fluoropolymer (A3 ′) dispersion and an acrylic resin dispersion.
The mass ratio of the fluoropolymer (A3 ′) to the acrylic resin (the fluoropolymer (A3 ′) / acrylic resin) is preferably 10/90 to 90/10, and more preferably 20/80 to 80/20. . When there are too many fluoropolymers (A3 '), the film-forming property of a coating film and the adhesiveness to a base material will fall. When there are too many acrylic resins, the weather resistance of a coating film will fall.
As the fluorine-containing resin aqueous dispersion (A3) containing an acrylic resin, a product name “Kynar Aquatec FMA-12” (vinylidene fluoride polymer / acrylic resin = 50/50 (mass ratio)) manufactured by Arkema, Inc. = Methyl methacrylate unit / ethyl methacrylate unit / butyl methacrylate unit = 60/20/20 (mass ratio)).

(Silicone resin (c))
The silicone resin (c) is obtained by dispersing or dissolving a silicone resin in an aqueous medium. Examples of the silicone resin (c) include silicone oils and silicone resins composed of dialkylpolysiloxanes such as dimethylpolysiloxane, polyarylsiloxanes such as polydiphenylsiloxane, polyalkylarylsiloxanes such as methylphenylpolysiloxane, or amino-modified. What emulsified modified silicone oil, modified silicone resin, etc., such as silicone, epoxy modified silicone, carboxyl modified silicone, alcohol modified silicone, and polyether modified silicone, can be used.
The average particle diameter of the silicone resin (c) is preferably 10 to 50 nm.

(Other ingredients)
In the fluorine-containing resin coating composition of the present invention, the fluorine-containing resin and the specific gravity are in the range of 0.90 to 1.03 and the boiling point is in the range of 230 to 350 ° C. within the range not impairing the effects of the present invention. And 5% weight loss temperature measured by Tg-DTA (temperature increase rate: 10 ° C./min) in the range of 150 to 250 ° C. and other components in addition to water May be.
Examples of other components include known coating additives. Specifically, isocyanate curing agents, blocked isocyanate curing agents, melamine resins, synthetic resin emulsions (however, fluorine-containing resin (a) and silicone) Resin (c) is excluded.), Inorganic color pigments, organic color pigments, extender pigments, curing catalysts, plasticizers, preservatives, antifungal agents, antifoaming agents, leveling agents, pigment dispersants, antisettling agents, Anti-sagging agents, matting agents, ultraviolet absorbers, antioxidants and the like can be mentioned. You may mix | blend 2 or more types of another component with the fluorine-containing resin coating composition of this invention.

  Synthetic resin emulsions include, for example, ethylene resin emulsions, vinyl acetate resin emulsions, polyester resin emulsions, alkyd resin emulsions, vinyl chloride resin emulsions, epoxy resin emulsions, acrylic resin emulsions, urethane resin emulsions, fluororesin emulsions (however, fluorine-containing emulsions) Resin (a) and silicone resin (c) are excluded.) Or a composite system of these.

As said synthetic resin emulsion, it is preferable that a glass transition temperature is -5-80 degreeC acrylic resin emulsion. When the glass transition temperature is lower than 5 ° C., the tackiness of the coating film becomes strong and dirt is likely to adhere. When the temperature is higher than 80 ° C., a large amount of film forming aid is required to form a film at room temperature.
The average particle size of the acrylic resin emulsion is preferably 100 to 200 nm.

  The acrylic resin emulsion is preferably an emulsion having a (meth) acrylic acid ester and a structural unit based on an unsaturated monomer having an ultraviolet stabilizing group and / or an ultraviolet absorbing group. As the (meth) acrylic acid ester, a (meth) acrylic acid ester having a cyclohexyl group and a tertiary butyl group is preferable, and as the unsaturated monomer having an ultraviolet stabilizing group and / or an ultraviolet absorbing group, 2, 2, Unsaturated monomers having a 6,6-tetrasubstituted piperidyl group are preferred.

  Although the manufacturing method of the said synthetic resin emulsion is not specifically limited, For example, it can manufacture by methods, such as batch polymerization, monomer dripping polymerization, emulsion monomer dripping polymerization, as an emulsion polymerization method. As the emulsifier used for the polymerization, one or more selected from anionic emulsifier, nonionic emulsifier, cationic emulsifier and amphoteric emulsifier can be used.

When mix | blending the said synthetic resin emulsion, the solid content mass ratio of a silicone resin (c) and the said synthetic resin emulsion is 1.0: 99.0-50.0: 50.0, Preferably, it is 2. It is 0: 98.0-40.0: 60.0, More preferably, it is 3.0: 97.0-30.0: 70.0.
When the amount of the silicone resin (c) is less than this ratio, the moisture absorption / release property is lowered. In addition, the texture of the coating film may be impaired.
When there are more silicone resins (c) than this ratio, film forming property will fall.

(Function and effect)
In the fluorine-containing resin coating composition of the present invention described above, the film-forming property of the coating film is good, and the weather resistance, blocking resistance, and warm water resistance of the coating film are excellent.

<Coated article with coating film>
The coated article of the present invention has a coating film formed using the fluorine-containing resin coating composition of the present invention.
The coated article of the present invention can be produced by applying the fluororesin coating composition of the present invention to the surface of a substrate and drying it to form a coating film on the surface of the substrate.

Base materials include metal material base materials, glass base materials, porcelain tile base materials, concrete base materials, siding board base materials, ceramic base materials, extruded plate base materials, synthetic resin base materials, artificial marble base materials, and wood. A base material etc. are mentioned, and housings, such as a building and a civil engineering structure, are suitable. In a factory or the like, the surface of the building material before being assembled into a housing may be precoated.
The fluorine-containing resin coating composition of the present invention may be applied directly to a substrate, or may be applied after a known surface treatment (such as a base treatment) is applied to the substrate. Examples of the application method include brush coating, spraying, rollers, roll coaters, flow coaters and the like.

(Function and effect)
In the coated article of the present invention described above, since it has a coating film made of the fluorine-containing resin coating composition of the present invention that can exhibit the above-described effects, sufficient weather resistance, blocking resistance, and warm water resistance are provided. It has a coating film.

  Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to these examples.

(Blocking resistance)
The coated surfaces of the two test plates were overlapped, a load of 0.05 MPa was applied, and after standing at 50 ° C. for 1 hour, the state of the coating film when the test plate was separated was evaluated according to the following criteria.
○: No change in the coating surface △: Damage was observed on a part of the coating film ×: Damage was observed on the entire surface of the coating film

(Weather resistance test)
The obtained test plate was installed outdoors in Naha City, Okinawa Prefecture, and the gloss retention rate of the coating film was evaluated by comparing immediately before and after two years.
In the evaluation, the gloss of the coating film surface was measured using a gloss meter (PG-1M, manufactured by Nippon Denshoku Industries Co., Ltd.), and the weather resistance was evaluated according to the following criteria.
“◯”: The gloss retention was 80% or more.
"X": The gloss retention was less than 80%.

(Warm-resistant immersion test-1)
After the test plate was immersed in warm water of 60 ° C. for 7 days, the test plate was taken out and evaluated according to the following criteria.
○: No whitening or blistering was observed on the coating surface.
X: Generation | occurrence | production of whitening and blistering was recognized by the coating-film surface.

(Warm-resistant immersion test-2)
The test plate was immersed in warm water at 60 ° C. for 8 hours, and then the test plate was taken out and immersed in cold water at 5 ° C. Then, it was immersed in 5 degreeC cold water for 14 hours, and after taking out a test board, it was left to stand in 5 degreeC environment for 3 hours, and evaluated the whitening and blistering of a coating film according to the following references | standards.
○: No whitening or blistering was observed on the coating surface.
X: Generation | occurrence | production of whitening and blistering was recognized by the coating-film surface.

(Monomer)
Monomer (m1):
CTFE: Chlorotrifluoroethylene monomer (m2):
_{CM-EOVE: CH 2 = CHOCH} 2 -cycloC 6 H 10 -CH 2 (OCH 2 CH 2) t OH ( number average molecular weight 830)
Monomer (m3):
_{CHMVE: CH 2 = CHOCH 2 -cycloC} 6 H 10 -CH 2 OH
Monomer (m4):
CHVE: cyclohexyl vinyl ether 2-EHVE: 2-ethylhexyl vinyl ether EVE: ethyl vinyl ether

Monomer (b1):
CTFE: chlorotrifluoroethylene monomer (b2):
EVE: ethyl vinyl ether CHVE: cyclohexyl vinyl ether monomer (b3):
4-HBVE: 4-hydroxybutyl vinyl ether

(Preparation Example 1)
Preparation of fluororesin aqueous dispersion (A1-1):
In a stainless steel autoclave with a stirrer with an internal volume of 2500 mL, 1280 g of water, 415 g of CHVE, 230 g of 2-EHVE, 21 g of CM-EOVE, 34 g of CHMVE, 1280 g of ion-exchanged water, 3.0 g of potassium carbonate, 5.4 g of ammonium persulfate, 33 g of nonionic emulsifier (Nippon Emulsifier Co., Ltd., Newcol (registered trademark) -2320), 1.4 g of anionic emulsifier (sodium lauryl sulfate) were charged, cooled with ice, and nitrogen gas And deaerated under pressure to 0.4 MPaG. This pressure degassing was repeated twice. After degassing to 0.095 MPaG to remove dissolved air, 580 g of CTFE was charged and the reaction was carried out at 50 ° C. for 24 hours. After reacting for 24 hours, the autoclave was cooled with water to stop the reaction. After cooling this reaction liquid to room temperature, the unreacted monomer was purged to obtain a fluororesin aqueous dispersion (A1-1) having a solid concentration of 50% by mass. The hydroxyl value of the fluorine-containing copolymer (A1′-1) contained therein was 10 mgKOH / g. The ratio of the structural units of the fluorinated copolymer (A1′-1) was as follows: CTFE units / CM-EOVE units / CHMVE units / CHVE units / 2-EHVE units = 50 / 0.25 / 2/33 / 14.75. (Molar ratio).

(Preparation Example 2)
Preparation of fluororesin aqueous dispersion (A1-2):
In a stainless steel autoclave with a stirrer with an internal volume of 2500 mL, 1280 g of water, 185 g of EVE, 244 g of CHVE, 47 g of CM-EOVE, 194 g of CHMVE, 1280 g of ion-exchanged water, 2.0 g of potassium carbonate, ammonium persulfate Of nonionic emulsifier (manufactured by Nippon Emulsifier Co., Ltd., Newcol (registered trademark) -2320), 1.4 g of anionic emulsifier (sodium lauryl sulfate) were charged with ice and cooled with nitrogen gas. Pressurized and degassed to 4 MPaG. This pressure degassing was repeated twice. After degassing to 0.095 MPaG to remove dissolved air, 664 g of CTFE was charged and the reaction was carried out at 50 ° C. for 24 hours. After reacting for 24 hours, the autoclave was cooled with water to stop the reaction. After cooling this reaction liquid to room temperature, the unreacted monomer was purged to obtain a fluororesin aqueous dispersion (A1-2) having a solid concentration of 50% by mass. The hydroxyl value of the fluorine-containing copolymer (A1′-2) contained therein was 55 mgKOH / g. The ratio of the constituent units of the fluorinated copolymer (A1′-2) is as follows: CTFE units / CM-EOVE units / CHMVE units / EVE units / CHVE units = 50 / 0.5 / 10/17 / 22.5 (moles) Ratio).

(Preparation Example 3)
Preparation of fluororesin aqueous dispersion (A2-1):
Fluorine-containing copolymer (B) (manufactured by Asahi Glass Co., Ltd., Lumiflon (registered trademark) flake, CTFE unit / EVE unit / CHVE unit / 4-HBVE unit = 50/15/15/20 (molar ratio), hydroxyl value: 100 mgKOH / G, mass average molecular weight: 7000) was dissolved in methyl ethyl ketone (MEK) to obtain a varnish having a solid content of 60% by mass.
To 300 g of this varnish, 4.8 g of succinic anhydride and 0.072 g of triethylamine as a catalyst were added and reacted at 70 ° C. for 6 hours for esterification. When the infrared absorption spectrum of the reaction solution was measured, the characteristic absorption (1850 cm ⁻¹ , 1780 cm ⁻¹ ) of the acid anhydride observed before the reaction disappeared after the reaction, and the carboxylic acid (1710 cm ⁻¹ ) and ester were lost. Absorption of (1735 cm ⁻¹ ) was observed. The hydroxyl value of the fluorinated copolymer (B) after esterification was 85 mg / KOH, and the acid value was 15 mgKOH / g.
Next, 4.9 g of triethylamine was added to the fluorine-containing copolymer (B) after esterification, and the mixture was stirred at room temperature for 20 minutes to neutralize the carboxylic acid, and 180 g of ion-exchanged water was gradually added.
Finally, acetone and methyl ethyl ketone were distilled off under reduced pressure. Using ion-exchanged water, a fluororesin aqueous dispersion (A2-1) having a solid concentration of 50% by mass was prepared. The ratio of the constituent units of the fluorinated copolymer (A2′-1) was as follows: CTFE unit / EVE unit / CHVE unit / 4-HBVE unit / esterified 4-HBVE unit = 50/15/15/17/3 (Molar ratio). Among the esterified 4-HBVE units, the proportion neutralized with triethylamine was 70 mol%.

Example 1
80 g of the fluororesin aqueous dispersion (A1-1) obtained in Preparation Example 1, SDX-3652 (made by ADEKA, trade name, 2-ethylhexyl benzoate, specific gravity: 0.962, boiling point: 277 as a film-forming aid 0 g of a thickener (Rohm & Haas, Primal (registered trademark) TT-615) 6 g 0.4 g, 0.6 g of an antifoaming agent (manufactured by BASF, Dehydran (registered trademark) 1620), and 13 g of ion-exchanged water were added and mixed to prepare a fluorine-containing resin coating composition (1).

(Example 2)
The fluororesin coating composition (2) was prepared in the same manner except that the fluororesin aqueous dispersion (A1-1) used in Example 1 was changed to a fluororesin aqueous dispersion (A1-2). Prepared.

(Example 3)
Except for changing the fluororesin aqueous dispersion (A1-1) used in Example 1 to a fluororesin aqueous dispersion (manufactured by Arkema, product name “Kynar Aquatec FMA-12”), the same method was used. A fluorine-containing resin coating composition (3) was prepared.

Example 4
The fluororesin aqueous dispersion (A1-1) used in Example 1 was changed to a combination of the fluororesin aqueous dispersion (A1-2) and the fluororesin aqueous dispersion (A2-1). Prepared a fluororesin coating composition (4) in the same manner.

(Example 5)
SDX-3652 (manufactured by ADEKA, trade name, 2-ethylhexyl benzoate, specific gravity: 0.962, boiling point: 277 ° C., Tg-DTA (temperature increase rate: 10 ° C./min) as a film-forming auxiliary used in Example 1 ) Was measured with SDX-3789 (trade name, manufactured by ADEKA, dibutoxyethyl adipate, specific gravity: 0.996, boiling point: 290 ° C., Tg-DTA (temperature increase rate: 10). Fluorine-containing resin coating composition (5) was prepared in the same manner except that the temperature was changed to 5% weight loss temperature (215 ° C) measured in ° C / min).

(Example 6)
70 g of the fluororesin aqueous dispersion (A1-2) obtained in Preparation Example 2, 6 g of SDX-3652 (manufactured by ADEKA, trade name, 2-ethylhexyl benzoate) as a film-forming aid, thickener (Rohm & 0.4 g of Haas, Primal (registered trademark) TT-615), 0.6 g of defoaming agent (manufactured by BASF, Dehydran (registered trademark) 1620), 13 g of ion-exchanged water, Udouble EF-010 (Japan) 10g of a catalyst company make, brand name, a silicone resin emulsion (average particle diameter: 23 nm) and an acrylic resin emulsion (average particle diameter: 164 nm)) are added and mixed to prepare a fluorine-containing resin coating composition (6). did.

(Example 7)
60 g of the fluororesin aqueous dispersion (A1-2) obtained in Preparation Example 2, Udouble EF-010 (manufactured by Nippon Shokubai Co., Ltd., trade name, silicone resin emulsion (average particle size: 23 nm) and acrylic resin emulsion (average particle) A fluorine-containing resin coating composition (7) was prepared in the same manner as in Example 7, except that the mixture (diameter: 164 nm) was changed to 20 g.

(Comparative Example 1)
SDX-3652 (manufactured by ADEKA, trade name, 2-ethylhexyl benzoate, specific gravity: 0.962, boiling point: 277 ° C., Tg-DTA (temperature increase rate: 10 ° C./min) as a film-forming auxiliary used in Example 1 ) Was measured with texanol (trade name, manufactured by Eastman Chemical Co., specific gravity: 0.940, boiling point: 250 ° C., Tg-DTA (temperature increase rate: 10 ° C./min)). The fluororesin coating composition (8) was prepared in the same manner except that the 5% weight loss temperature was changed to 139 ° C.

(Preparation of test plate)
On a surface of a slate plate having a length of 120 mm, a width of 60 mm, and a thickness of 15 mm, Dainippon Paint Co., Ltd. product name V-Selan # 700 was applied by air spray so that the dry film thickness was 20 μm. Dry for 2 seconds.
Thereafter, the fluororesin coating composition obtained in each of Examples 1 to 7 and Comparative Example 1 was applied by air spray so that the dry film thickness was 40 μm, and dried at 100 ° C. for 210 seconds, A test plate was prepared.
Table 1 shows the evaluation results of the obtained test plate.

As shown in the results of Table 1, the specific gravity is 0.90 to 1.03, the boiling point is 230 to 350 ° C., and the 5% weight loss temperature measured by Tg-DTA (temperature increase rate: 10 ° C./min) is 150 to 250. The fluorine-containing resin coating composition using an ester compound in the range of ° C. as a film-forming aid does not cause whitening of the coating film after it is immersed in warm water, and is also resistant to weathering and blocking. It was excellent.
On the other hand, in Comparative Example 1, the coating film was whitened in the same test, and the weather resistance and blocking resistance were inferior.
From this, it can be seen that Examples 1 to 7 improved the weather resistance, blocking resistance, and hot water resistance of the coating film.

  The fluorine-containing resin coating composition of the present invention is useful as a coating for exteriors of buildings and the like that are easily exposed to rain and wind whitening.

Claims (4)

A fluorine-containing resin (a);
The specific gravity is in the range of 0.90 to 1.03, the boiling point is in the range of 230 to 350 ° C., and the 5% weight loss temperature measured by Tg-DTA (temperature increase rate: 10 ° C./min) is 150 to An ester compound (b) in the range of 250 ° C .;
And the water has including,
The fluorine-containing resin coating composition, wherein the ester compound (b) is a compound represented by the following formula (1) or dibutoxyethyl adipate .
However, in Formula (1), R < ¹ > -R < ⁵ > is a hydrogen atom or a C1-C6 alkyl group each independently, and R < ⁶ > is a C3-C15 linear or branched alkyl group. is there. The fluorine-containing resin coating composition of Claim 1 which contains 1-15 mass parts of ester compounds (b) with respect to 100 mass parts of fluorine-containing resin (a). Furthermore, 5-30 mass parts of silicone resins (c) are contained with respect to 100 mass parts of fluororesin (a), The fluorine-containing resin coating composition of Claim 1 or 2 . A coated article comprising a coating film formed using the fluorine-containing resin coating composition according to any one of claims 1 to 3 .