JP2011256257A - Fluorine-coating containing composition and kit for two-liquid coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorine-coating containing composition which is short in curing/drying time at the formation of a coating film, sufficient in weatherability in the obtained coating film, and can secure transparency, and a kit for a two-liquid coating for adjusting the fluorine-coating containing composition.SOLUTION: There is provided the fluorine-coating containing composition containing (A) a fluorine copolymer which has a hydroxyl group and a carboxyl group, and is 3 to 10 mg-KOH/g in acid number, and (B) a polyisocyanate compound expressed by the following formula (1). There is also provided the kit for the two-liquid coating which uses the (A) component as a main agent, and the (B) component as a curing agent. The formula (1) is R-(NCO)n (wherein, R denotes a residue group except for an isocyanate group in a polyisocyanate compound which is derived from diisocyanate composed of at least one selected from aliphatic diisocyanate and alicyclic diisocyanate, and polyol, and n is 3 to 20.).

Description

  The present invention relates to a fluorine-containing coating composition and a two-component coating kit.

  Conventionally, fluorine-containing paint compositions have been widely used in fields where properties such as mechanical strength, weather resistance, waterproof / moisture-proof properties, and electrical insulation are required. Techniques related to certain curable functional group-containing fluorine-containing copolymers have been developed (for example, Patent Document 1). In such a fluorine-containing coating composition, in many cases, the curable functional group-containing fluorine-containing copolymer is combined with a curing agent having a functional group reactive with the curable functional group. It is blended.

  Here, it is desirable that the curing and drying of the coating material in the industrial field is low in cost and in a short period of time. In particular, the coating material is not limited to the above-described fluorine-containing coating composition, and a curing agent having high drying curability is used. Attempts have been made to shorten the curing and drying time of the coating material.

  As such a curing agent, a technique relating to a curing agent comprising a polyisocyanate composition has been developed. For example, Patent Document 2 discloses a polyisene derived from a polyol and / or one of an aliphatic isocyanate and an alicyclic isocyanate. There is a description that a polyisocyanate composition containing an isocyanate and a polyisocyanate containing hexamethylene diisocyanate at a specific ratio can exhibit a low viscosity and excellent crosslinkability. In Patent Document 3 and Patent Document 4, a polyisocyanate composition having properties such as specific viscosity, molecular weight, glass transition point, etc. obtained by modifying an aliphatic diisocyanate and an alicyclic diisocyanate with a polyol is crosslinked. It is described that it becomes a curing agent for paints with excellent properties and drying properties.

  In Patent Documents 2 to 4, when a polyisocyanate composition is blended in a coating material as a curing agent, it has two or more active hydrogens having reactivity with an isocyanate group in the molecule as a crosslinkable compound to be combined therewith. Compounds such as polyols, polyamines, polythiols and the like are mentioned. As the polyols, fluorine-containing polyols described in Patent Document 1 are mentioned.

  However, when a fluorine-containing polyol and a curing agent comprising such a polyisocyanate composition are used in combination as a coating composition, the curing and drying time is shortened, but depending on the fluorine-containing polyol used, the coating composition may become cloudy. There are problems such as being unsuitable for applications requiring transparency, and weather resistance being lowered due to cloudiness.

Japanese Patent Laid-Open No. 57-034107 JP 2007-145988 A JP 2008-156450 A International Publication No. 2005/082966 Pamphlet

  The present invention has been made to solve the above-mentioned problems, and includes a curing and drying time at the time of forming a coating film, the resulting coating film having sufficient weather resistance and ensuring transparency. It is an object of the present invention to provide a fluorine paint composition and a two-component paint kit for preparing the fluorine-containing paint composition.

（上記式（２）中、数平均分子量はポリイソシアネート化合物の数平均分子量である。）
本発明の含フッ素塗料組成物は、［２］の構成とすることもできる。
［２］前記式（１）で表わされるポリイソシアネート化合物を構成するジイソシアネート残基が、脂肪族ジイソシアネート残基／脂環族ジイソシアネート残基で示す質量比で９５／５〜５０／５０となる割合である［１］に記載の含フッ素塗料組成物。 One embodiment of the fluorine-containing coating composition of the present invention has the configuration [1].
[1] A fluorine-containing coating composition containing a fluorine-containing copolymer having a hydroxyl group and a carboxyl group and a polyisocyanate compound represented by the following formula (1), wherein the acid value of the fluorine copolymer is 1 A fluorine-containing coating composition, characterized in that it is -12 mg / KOH.
R- (NCO) n (1)
(In Formula (1), R is a residue except the isocyanate group in the polyisocyanate compound induced | guided | derived from the diisocyanate and polyol which consist of at least 1 sort (s) chosen from aliphatic diisocyanate and alicyclic diisocyanate, and n is the following. (It is calculated | required from Formula (2) and is 3-20.)

(In the above formula (2), the number average molecular weight is the number average molecular weight of the polyisocyanate compound.)
The fluorine-containing coating composition of the present invention may be configured as [2].
[2] In a ratio in which the diisocyanate residue constituting the polyisocyanate compound represented by the formula (1) is 95/5 to 50/50 in terms of mass ratio represented by aliphatic diisocyanate residue / alicyclic diisocyanate residue. The fluorine-containing coating composition according to [1].

The fluorine-containing coating composition of the present invention may be configured as [3].
[3] The ratio of the polyol compound residue constituting the polyisocyanate compound represented by the formula (1) is 1 to 50% by mass with respect to the total amount of the polyisocyanate compound, according to [1] or [2] Fluorine-containing paint composition.
The fluorine-containing coating composition of the present invention may be configured as [4].
[4] The fluorine-containing coating composition according to any one of [1] to [3], wherein the fluorine-containing copolymer has a hydroxyl value of 20 to 200 mg / KOH.
The fluorine-containing coating composition of the present invention can also be configured as [5].
[5] The fluorine-containing copolymer is a polymer having a polymer unit based on at least one fluoroolefin selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinylidene fluoride and vinyl fluoride. The fluorine-containing coating composition according to any one of [1] to [4], which is a coalescence.

（上記式（２）中、数平均分子量はポリイソシアネート化合物の数平均分子量である。） Moreover, one Embodiment of the kit for two-component paints of this invention has the structure of [6].
[6] A two-component paint kit comprising the following main agent (A) and curing agent (B).
Main agent (A): A composition containing a fluorine-containing copolymer having a hydroxyl group and a carboxyl group and having an acid value of 3 to 10 mg / KOH.
Curing agent (B): A composition containing a polyisocyanate compound represented by the following formula (1).
R- (NCO) n (1)
(In Formula (1), R is a residue except the isocyanate group in the polyisocyanate compound induced | guided | derived from the diisocyanate and polyol which consist of at least 1 sort (s) chosen from aliphatic diisocyanate and alicyclic diisocyanate, and n is the following. (It is calculated | required from Formula (2) and is 3-20.)

(In the above formula (2), the number average molecular weight is the number average molecular weight of the polyisocyanate compound.)

The two-component paint kit of the present invention can also be configured as [7].
[7] The diisocyanate residue constituting the polyisocyanate compound represented by the formula (1) is a ratio of 95/5 to 50/50 in terms of mass ratio represented by aliphatic diisocyanate residue / alicyclic diisocyanate residue. The two-component paint kit according to [6].
The two-component paint kit of the present invention may be configured as [8].
[8] The ratio of the polyol residue constituting the polyisocyanate compound represented by the formula (1) is 1 to 50% by mass with respect to the total amount of the polyisocyanate compound, according to [6] or [7] Liquid paint kit.

  According to the fluorine-containing coating composition of the present invention and the two-component coating kit for preparing the fluorine-containing coating composition, the curing and drying time at the time of forming the coating film is short, and the resulting coating film has sufficient weather resistance. It is possible to ensure transparency.

In the present specification, unless otherwise specified, “%” represents “mass%”. The “polymerization unit” of the fluorinated copolymer may be referred to as “unit”, and the “polymerization unit formed by the monomer” may be referred to as “monomer unit”. Monomers and olefins other than the above may be described in the same manner. “(Meth) acrylic acid” is used as a general term for both acrylic acid and methacrylic acid.
Embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments.

[Fluorine-containing paint composition]
The fluorine-containing coating composition of the present invention contains a fluorine-containing copolymer having a hydroxyl group and a carboxyl group and an acid value of 3 to 10 mg / KOH and a polyisocyanate compound represented by the above formula (1).
In the fluorine-containing coating composition of the present invention, the fluorine-containing copolymer functions as a crosslinkable component, and the polyisocyanate compound functions as a curing agent. The hydroxyl group of the fluorine-containing copolymer and the isocyanate group of the polyisocyanate compound. React to form a coating film by crosslinking and curing.

(1) Fluorine-containing copolymer The fluorine-containing copolymer contained in the fluorine-containing coating composition of the present invention is a copolymer having a fluorine atom, a hydroxyl group and a carboxyl group, and its acid value is 3 to 10 mg / KOH. It is. Hereinafter, the monomer which forms the polymerization unit which comprises this fluorine-containing copolymer is demonstrated.

  If the fluorine-containing copolymer used for this invention is a copolymer which has a fluorine atom, a hydroxyl group, and a carboxyl group, the monomer which forms the polymer unit which comprises this will not be restrict | limited in particular.

  The fluorine-containing copolymer may include, for example, a combination of units based on a monomer having both a fluorine atom and a hydroxyl group or a carboxyl group, a hydroxyl group and a carboxyl group, or a fluorine atom, a hydroxyl group, and a carboxyl group. Are usually units based on monomers independently having these atoms or functional groups, that is, (a) units based on monomers having fluorine atoms, (b) units based on monomers having hydroxyl groups And (c) a unit including a unit based on a monomer having a carboxyl group, and preferably (d) a unit based on another alkyl group-containing monomer connected by an ether bond or an ester bond. It is the composition which includes. In addition, the fluorine-containing copolymer used for this invention may contain the unit based on (e) other monomers other than (a)-(d) as needed.

(A) Monomer having a fluorine atom Examples of the monomer having a fluorine atom include a fluorine-containing monomer usually used as a fluororesin raw material without any limitation. Specifically, tetrafluoroethylene (TFE), hexafluoropropylene (HFP), chlorotrifluoroethylene (CTFE), vinylidene fluoride (VdF), vinyl fluoride (VF), perfluoro (alkyl vinyl ether) (PAVE) And a monomer in which a fluoroalkyl group and a polymerizable unsaturated group are linked by an ether bond or an ester bond (hereinafter also referred to as a “monomer having a fluoroalkyl group”). Among these, TFE, HFP, CTFE, VdF, and VF are preferable, and TFE and CTEF are particularly preferable. These can be used alone or in combination of two or more.

(B) Monomer having a hydroxyl group The monomer having a hydroxyl group has a hydroxyl group and forms a polymer unit of the fluorine-containing copolymer used in the present invention in addition to the monomer (a) having a fluorine atom. Any monomer having a polymerizable unsaturated group that can be copolymerized with other monomers can be used without particular limitation.

  Examples of such a hydroxyl group-containing monomer include 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether, 2-hydroxy-2-methylpropyl vinyl ether, 4-hydroxybutyl vinyl ether, 4- Hydroxyalkyl vinyl ethers such as hydroxy-2-methylbutyl vinyl ether, 5-hydroxypentyl vinyl ether and 6-hydroxyhexyl vinyl ether; ethylene glycol monovinyl ethers such as diethylene glycol monovinyl ether, triethylene glycol monovinyl ether and tetraethylene glycol monovinyl ether; Ethyl allyl ether, hydroxybutyl allyl ether, 2-hydroxyethyl allyl ether Hydroxyalkyl allyl ethers such as ether, 4-hydroxybutyl allyl ether and glycerol monoallyl ether; hydroxyalkyl vinyl esters such as hydroxyethyl vinyl ester and hydroxybutyl vinyl ester; hydroxy such as hydroxyethyl allyl ester and hydroxybutyl allyl ester Alkyl allyl esters; (meth) acrylic acid hydroxyalkyl esters such as hydroxyethyl (meth) acrylate are preferred.

  Monomers having a hydroxyl group can be used alone or in combination of two or more.

(B) Monomer having a carboxyl group The monomer having a carboxyl group has a carboxyl group, and forms a polymer unit of a fluorine-containing copolymer in addition to the monomer (a) having a fluorine atom. Any monomer having a polymerizable unsaturated group that can be copolymerized with other monomers can be used without particular limitation. Although it is a monomer having such a carboxyl group and a polymerizable unsaturated group, an acid anhydride of an unsaturated dicarboxylic acid is also easily converted into a monomer having a carboxyl group. Treats an acid anhydride of an unsaturated dicarboxylic acid as a monomer equivalent to a monomer having a carboxyl group.

  Examples of the monomer having a carboxyl group include 3-butenoic acid, 4-pentenoic acid, 2-hexenoic acid, 3-hexenoic acid, 5-hexenoic acid, 2-heptenoic acid, 3-heptenoic acid, 6- Heptenoic acid, 3-octenoic acid, 7-octenoic acid, 2-nonenoic acid, 3-nonenoic acid, 8-nonenoic acid, 9-decenoic acid or 10-undecenoic acid, acrylic acid, methacrylic acid, vinylacetic acid, crotonic acid, Unsaturated carboxylic acids such as cinnamic acid; saturated carboxylic acids such as vinyloxyvaleric acid, 3-vinyloxypropionic acid 3- (2-vinyloxybutoxycarbonyl) propionic acid, 3- (2-vinyloxyethoxycarbonyl) propionic acid Vinyl ethers; allyloxyvaleric acid, 3-allyloxypropionic acid, 3- (2-allyloxybutoxycarbonyl) propio Acid, saturated carboxylic acid allyl ethers such as 3- (2-allyloxyethoxycarbonyl) propionic acid; 3- (2-vinyloxyethoxycarbonyl) propionic acid, 3- (2-vinyloxybutoxycarbonyl) propionic acid and the like Carboxylic acid vinyl ethers; saturated polyvalent carboxylic acid monovinyl esters such as monovinyl adipate, monovinyl succinate, vinyl phthalate, vinyl pyromellitic acid; itaconic acid, maleic acid, fumaric acid, maleic anhydride, itaconic anhydride Unsaturated dicarboxylic acids such as, for example, or intramolecular acid anhydrides thereof; unsaturated carboxylic acid monoesters such as itaconic acid monoester, maleic acid monoester, and fumaric acid monoester are preferred.

  The monomer which has a carboxyl group can also be used individually by 1 type, and can also use 2 or more types together.

  As a method of introducing a carboxyl group into the fluorine-containing copolymer used in the present invention, in addition to the method of copolymerizing a monomer having a carboxyl group as described above, the above monomer having a hydroxyl group is copolymerized. In addition, a method of acid-modifying a part of the introduced hydroxyl group can be mentioned. The acid modification is preferably performed by allowing a dicarboxylic acid or an acid anhydride of dicarboxylic acid to act on the introduced hydroxyl group.

  The monomer having a preferred hydroxyl group in that case is the same as the monomer having a hydroxyl group described above. Preferred acid anhydrides include succinic anhydride, phthalic anhydride, hexahydrophthalic anhydride, methylbicyclo [2.2.1] heptane-2,3-dicarboxylic anhydride, bicyclo [2.2.1] heptane- 2,3-dicarboxylic anhydride, 4-methylhexahydrophthalic anhydride, 1,2-cyclohexanedicarboxylic anhydride, and cis-4-cyclohexene-1,2-dicarboxylic anhydride are preferred.

(D) Other alkyl group-containing monomers connected by ether bonds or ester bonds (hereinafter simply referred to as “alkyl group-containing monomers (d)”)
The alkyl group-containing monomer (d) is a monomer in which an alkyl group and a polymerizable unsaturated group are linked by an ether bond or an ester bond. Specifically, the following general formula (3), (4) The monomer represented by either (5) is mentioned.

R ¹ —O—R ² (3)
R ¹ —COO—R ² (4)
R ¹ —OC (O) —R ² (5)
(In the above formulas (3) to (5), R ¹ represents a linear or branched alkyl group having 2 to 20 carbon atoms not containing a quaternary carbon, and R ² represents a polymerizable unsaturated group.)

In addition, the preferable combination of the structure of an alkyl group (R < ¹ >), a coupling bond, and the structure of a polymerizable unsaturated group (R < ² >) in said formula (3)-(5) is as follows.

  When the alkyl group-containing monomer (d) is an alkyl vinyl ether and the alkyl group is a linear monovalent saturated aliphatic hydrocarbon group, ethyl vinyl ether, n-propyl vinyl ether, n-butyl vinyl ether, octadecyl vinyl ether, etc. Linear monovalent saturated aliphatic alkyl vinyl ether is preferred. When the alkyl group is a branched monovalent saturated aliphatic hydrocarbon group, branched monovalent saturated aliphatic alkyl vinyl ethers such as 2-ethylhexyl vinyl ether, isopropyl vinyl ether, and isobutyl vinyl ether are preferable. In the case of a combination in which the alkyl group-containing monomer (d) is an alkyl vinyl ether, the alkyl group-containing monomer (d) is particularly preferably ethyl vinyl ether or 2-ethylhexyl ether.

  When the alkyl group-containing monomer (d) is a carboxylic acid vinyl ester and the alkyl group is a linear monovalent saturated aliphatic group, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl laurate, stearic acid Linear monovalent saturated aliphatic carboxylic acid vinyl esters such as vinyl are preferred. Further, when the alkyl group is a branched monovalent saturated aliphatic hydrocarbon group, branched monovalent saturated aliphatic carboxylic acid vinyl esters such as vinyl isobutyrate and vinyl versatate are preferred.

  When the alkyl group-containing monomer (d) is an alkyl allyl ether and the alkyl group is a linear monovalent saturated aliphatic hydrocarbon group, ethyl allyl ether, n-propyl allyl ether, n-butyl allyl ether, Straight chain monovalent saturated aliphatic alkyl allyl ethers such as octadecyl allyl ether are preferred. In addition, when the alkyl group is a branched monovalent saturated aliphatic hydrocarbon group, branched monovalent saturated aliphatic alkyl allyl ethers such as 2-ethylhexyl allyl ether, isopropyl allyl ether, and isobutyl allyl ether are preferable. When the alkyl group-containing monomer (d) is an alkyl allyl ether, the alkyl group-containing monomer (d) is particularly preferably ethyl allyl ether or 2-ethylhexyl allyl ether.

  When the alkyl group-containing monomer (d) is a carboxylic acid allyl ester and the alkyl group is a linear monovalent saturated aliphatic group, allyl propionate, allyl butyrate, allyl caproate, allyl laurate, stearic acid Linear monovalent saturated aliphatic carboxylic acid allyl esters such as allyl are preferred. When the alkyl group is a branched monovalent saturated aliphatic hydrocarbon group, branched monovalent saturated aliphatic carboxylic acid allyl esters such as allyl vinylisobutyrate and allyl versatate are preferred.

  Examples of the alkyl group-containing monomer (d) in which the polymerizable unsaturated group is bonded to the carbon side of the ester bond include (meth) such as ethyl methacrylate, propyl methacrylate, isopropyl methacrylate, butyl methacrylate, isobutyl methacrylate, and cyclohexyl methacrylate. Acrylic esters are preferred.

  The alkyl group-containing monomer (d) can be used alone or in combination of two or more, but preferably used in combination of two or more. In that case, it is particularly preferable to contain at least one of ethyl vinyl ether and 2-ethylhexyl vinyl ether.

(E) Other monomers As other monomers that the fluorine-containing copolymer used in the present invention may contain in addition to the monomers (a) to (d), the effects of the present invention are included. Various monomers can be used according to the required characteristics as long as the above is not impaired. As such other monomers, non-fluorinated monomers are preferable, and monomers having no crosslinkable functional group are preferable. In addition, as other monomers, specifically, non-fluorinated olefins such as ethylene, propylene, n-butene and isobutene; non-fluorinated aromatics such as vinyl benzoate and vinyl para-t-butylbenzoate Group-containing monomers; t-butyl vinyl ether, vinyl pivalate and the like are preferable.

  The combination of units constituting the fluorinated copolymer used in the present invention depends on the combination of monomers used in the production of the fluorinated copolymer, except when the structural units are reacted directly after polymerization such as acid modification. Determined. As a combination of the monomers, depending on copolymerizability, ease of production, crosslinking system, etc., (a) a monomer having a fluorine atom, (b) a monomer having a hydroxyl group, (c) a carboxyl group (D) a combination containing another alkyl group-containing monomer connected by an ether bond or an ester bond, and further if necessary (e) Examples include combinations containing other monomers as appropriate.

  The content of the (d) alkyl group-containing monomer in the fluorinated copolymer is preferably 0 mol% to 65 mol% with respect to all units in the fluorinated copolymer, preferably 10 mol. It is more preferable that it is% -50 mol%. In addition, the content of the unit of the above (e) other monomer in the fluorine-containing copolymer is 0 mol% or more than 0 to 10 mol% or less with respect to all units in the fluorine-containing copolymer. More preferably.

  Preferred combinations of monomers include, for example, (a) a monomer having a fluorine atom, (c) a monomer having a carboxyl group, and (e) a monomer exemplified above as another monomer. It is preferable to select and use (b) a monomer having a hydroxyl group and (d) an alkyl group-containing monomer as follows.

  Expressing the combination of monomers as “(b) monomer having a hydroxyl group / (d) alkyl group-containing monomer”, hydroxyalkyl vinyl ether / alkyl vinyl ether, hydroxyalkyl vinyl ether / alkyl vinyl ester, hydroxyalkyl allyl ether / Alkyl allyl ether, hydroxyalkyl allyl ether / alkyl allyl ester, hydroxyalkyl allyl ether / alkyl vinyl ester, hydroxyalkyl allyl ether / alkyl vinyl ether are preferred combinations.

  More specifically, for example, CTFE / hydroxybutyl vinyl ether / monomer having a carboxyl group / ethyl vinyl ether / other monomer copolymer, CTFE / hydroxybutyl vinyl ether / monomer having a carboxyl group / 2 -Copolymer of ethylhexyl vinyl ether / other monomer, TFE / hydroxybutyl vinyl ether / monomer having carboxyl group / ethyl vinyl ether / copolymer of other monomer, TFE / hydroxybutyl vinyl ether / carboxyl group Preferred are monomer having 2-ethylhexyl vinyl ether / copolymer of other monomer.

  The fluorine-containing copolymer having a hydroxyl group and a carboxyl group used in the present invention can be prepared by acid-modifying a part of the hydroxyl group of the fluorine-containing copolymer having a hydroxyl group as described above. In that case, a fluorine-containing copolymer having a hydroxyl group is prepared by combining the above preferable monomer combinations excluding the monomer having a carboxyl group, and a part of the hydroxyl groups is conventionally known. The method of acid modification may be used.

  Moreover, in the combination preferable in the said invention, the combination which does not contain another monomer is mentioned as a preferable combination in this invention similarly to the above.

  Here, in the fluorine-containing copolymer used in the present invention, (a) a monomer having a fluorine atom, (b) a monomer having a hydroxyl group, and (c) a monomer having a carboxyl group are essential monomers. The component number of the monomer, (d) another alkyl group-containing monomer linked by an ether bond or an ester bond, and (e) the unit based on the other monomer, the acid value is 1 to 12 mg. The composition ratio should be such that the amount of the hydroxyl group reacts with the isocyanate group of the polyisocyanate compound described later, so that the fluorine-containing coating composition of the present invention containing these can be crosslinked and cured. For example, the content of each monomer unit can be appropriately adjusted within this range.

  For example, the content of the unit of the monomer having a fluorine atom in the fluorinated copolymer is preferably 30 to 70 mol% with respect to all units in the fluorinated copolymer, and preferably 40 to 60 mol. % Is more preferable. By setting the unit of the monomer having a fluorine atom in the fluorine-containing copolymer within the above range, both weather resistance and solubility in a solvent can be achieved.

  In the fluorine-containing copolymer used in the present invention, the acid value is in the range of 1 to 12 mg / KOH, preferably 1 to 10 mg / KOH, more preferably 3 to 7 mg / KOH.

  The acid value is adjusted by adjusting the amount of the carboxyl group possessed by the fluorinated copolymer, specifically, when the monomer having a carboxyl group is used for the copolymerization of the fluorinated copolymer. In the case of acid-modifying the amount of the monomer or the hydroxyl group of the fluorine-containing copolymer having a hydroxyl group, the proportion of the hydroxyl group modified to a carboxyl group can be adjusted. When the acid value of the fluorinated copolymer is less than 1 mg / KOH, white turbidity is produced when this is combined with the polyisocyanate compound represented by the above formula (1), resulting in a decrease in weather resistance. In addition, when the acid value of the fluorinated copolymer exceeds 12 mg / KOH, the reactivity with the isocyanate represented by the above formula (1) increases and the pot life (pot life) is shortened. Carbon dioxide is generated during the reaction. Then, foaming causes problems such as damage to the appearance of the coating film, loss of the coating film, and loss of the protective effect of the substrate.

  In the fluorine-containing copolymer used in the present invention, the hydroxyl value is preferably in the range of 20 to 200 mg / KOH, and more preferably in the range of 30 to 160 mg / KOH. The adjustment of the hydroxyl value can be performed by adjusting the amount of the hydroxyl group of the fluorine-containing copolymer, specifically, the amount of the monomer having a hydroxyl group to be blended during the copolymerization of the fluorine-containing copolymer. When the hydroxyl value of the fluorine-containing copolymer is 20 mg / KOH or more, it is preferable from the viewpoint of solvent resistance and abrasion resistance of the coating film, and when it is 200 mg / KOH or less, it is preferable from the viewpoint of weather resistance.

The molecular weight of the fluorinated copolymer used in the present invention is not particularly limited. However, from the viewpoint of the smoothness and weather resistance of the coating film, the mass average molecular weight (M _w ) is preferably 2,000 to 100,000, preferably 6,000 to 30,000. Are more preferred. In the present specification, the number average molecular weight (M _n ) and the mass average molecular weight (M _w ) are values obtained by measuring polystyrene as a standard substance by gel permeation chromatography.

  In addition, as a fluorine-containing copolymer which has a hydroxyl group and a carboxyl group used for this invention, and an acid value is the range of 1-12 mg / KOH, the fluorine-containing copolymer which satisfies this condition is contained in a commercial item. Since there is a composition, it can also be used. Examples of commercially available products include Lumiflon (made by Asahi Glass Co., Ltd.), Bonflon (made by AGC Asahi Glass Co-Tech Co., Ltd.), Zaffle (made by Daikin Industries, Ltd.), V Freon (made by Dainippon Paint Co., Ltd.), New Garmet, for example. A product suitable for the above conditions can be appropriately selected from a product group such as (Tobe). More specifically, examples of Lumiflon (Asahi Glass Co., Ltd.) include Lumiflon LF-400 used in Examples.

  The fluorine-containing copolymer used in the present invention is obtained by copolymerizing the above monomers by a conventionally known polymerization method, specifically, a polymerization method such as solution polymerization, emulsion polymerization or suspension polymerization. Can do. Moreover, the acid modification of the hydroxyl group performed as needed can also be performed using a conventionally well-known method.

  Further, in the present invention, the fluorine-containing copolymer is copolymerized with a mixture of monomers forming the polymer units constituting the fluorine-containing copolymer, so long as the effects of the present invention are not impaired. It can be blended into the fluorine-containing coating composition in the form of a composition containing a fluorine copolymer and a polymerization medium (hereinafter also referred to as “polymerized composition”), which is preferable from the viewpoint of workability.

  When the fluorine-containing coating composition is a solution-type coating, the fluorine-containing copolymer can be polymerized by a solution polymerization method, and the resulting polymerized composition can be directly blended into the fluorine-containing coating composition. At this time, it is preferable to adjust the concentration by considering the polymerization solvent as a medium and adding or removing the medium from the polymerized composition as necessary. The medium is preferably an organic solvent, and when the medium is added to the composition after polymerization, the medium to be added is more preferably the same organic solvent as the polymerization solvent.

  As the polymerization solvent for performing the solution polymerization, the same organic solvent as the preferable organic solvent in the medium of the fluorine-containing coating composition described later is preferable. Specifically, aromatic hydrocarbons such as toluene and xylene; ethanol, methanol Alcohols such as methyl ethyl ketone and acetone; hydrocarbons such as mineral spirit and mineral terpenes; and halogenated compounds such as HCFC-225 (dichloropentafluoropropane) and chlorobenzene trifluoride.

  When the fluorine-containing coating composition is a dispersion-type coating, the fluorine-containing copolymer is polymerized by an emulsion polymerization method, and the resulting polymerized composition is left as it is or after adjusting the concentration as necessary, It can mix | blend with a fluorine coating composition. In addition, using a dispersion obtained by dispersing a fluorine-containing copolymer obtained by a solution polymerization method in an aqueous dispersion medium, the concentration of the dispersion is adjusted as necessary to obtain a fluorine-containing coating composition. It can also be blended. When the fluorine-containing paint composition is a dispersion-type paint, the cured coating film layer has good water resistance, so that the fluorine-containing paint composition is obtained using a fluorine-containing copolymer obtained by solution polymerization. Is preferably prepared.

(2) Polyisocyanate Compound The polyisocyanate compound contained in the fluorine-containing coating composition of the present invention is a compound represented by the following general formula (1).
R- (NCO) n (1)
(In Formula (1), R is a residue except the isocyanate group in the polyisocyanate compound derived from the diisocyanate and polyol which consist of at least 1 sort (s) chosen from aliphatic diisocyanate and alicyclic diisocyanate, and n is 3 ~ 20.)

（上記式（２）中、数平均分子量はポリイソシアネート化合物の数平均分子量である。） In addition, the average number n of isocyanate groups is calculated | required by the following formula | equation (2).

(In the above formula (2), the number average molecular weight is the number average molecular weight of the polyisocyanate compound.)

  As the aliphatic diisocyanate used in the polyisocyanate compound, those having 4 to 30 carbon atoms are preferable. For example, tetramethylene-1,4-diisocyanate, pentamethylene-1,5-diisocyanate, hexamethylene diisocyanate (hereinafter referred to as HDI). 2), 2,2,4-trimethyl-1,6-diisocyanate hexane, lysine isocyanate, and the like. Among these, HDI is preferred from the viewpoint of industrial availability. Aliphatic diisocyanate may be used individually by 1 type, or may use 2 or more types together.

As the alicyclic diisocyanate used for the polyisocyanate compound, those having 8 to 30 carbon atoms are preferable. For example, isophorone diisocyanate (hereinafter referred to as IPDI), 1,3-bis (isocyanatomethyl) -cyclohexane, 4, 4'-dicyclohexylmethane diisocyanate, xylylene diisocyanate and the like can be mentioned. Among these, IPDI is preferable from the viewpoint of weather resistance and industrial availability. An alicyclic diisocyanate may be used individually by 1 type, or may use 2 or more types together.
The combination of aliphatic diisocyanate and alicyclic diisocyanate used for the polyisocyanate compound is preferably a combination of HDI and IPDI.

  Examples of the polyol used for the polyisocyanate compound include a low molecular polyol having a molecular weight of less than 500 and a high molecular polyol having a molecular weight of 500 or more. Examples of the low molecular polyol include diols, triols, and tetraols. Examples of the diols include ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,2-propanediol, 1,5- Pentanediol, 2-methyl-2,3-butanediol, 1,6-hexanediol, 1,2-hexanediol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 2,3- Dimethyl-2,3-butanediol, 2-ethyl-hexanediol, 1,2- Examples include kutandiol, 1,2-decanediol, 2,2,4-trimethylpentanediol, 2-butyl-2-ethyl-1,3-propanediol, and 2,2-diethyl-1,3-propanediol. Examples of the triols include glycerin and trimethylolpropane, and examples of the tetraols include pentaerythritol.

  In addition to the above, examples of the low molecular polyol include (1) diglycerin, ditrimethylolpropane, pentaerythritol, dipentaerythritol, etc. (2) erythritol, D-threitol, L-arabinitol, ribitol, xylitol, sorbitol. Sugar alcohol compounds such as mannitol, galactitol, rhamnitol, (3) monosaccharides such as arabinose, ribose, xylose, glucose, mannose, galactose, fructose, sorbose, rhamnose, fucose, ribodesource, (4) trehalose, sucrose Disaccharides such as maltose, cellobiose, gentiobiose, lactose, melibiose, (5) trisaccharides such as raffinose, gentianose, merecitose, (6) tetrasaccharides such as stachyose, etc. It is below.

Examples of the polymer polyol include polyester polyol, acrylic polyol, polyether polyol, and polyolefin polyol.
As the polyester polyol, for example, a dibasic acid selected from the group of carboxylic acids such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, or a mixture thereof Obtained by a condensation reaction with a single or mixture of polyhydric alcohols selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, glycerin, 1,4 butanediol, 1,6 hexanediol, etc. Examples thereof include polyester polyols and polycaprolactones obtained by ring-opening polymerization of ε-caprolactone to a polyhydric alcohol.

  Examples of the acrylic polyol include acrylic acid esters having active hydrogen such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxybutyl acrylate, etc., or glycerol monoester or methacrylic acid. Acid monoester, trimethylolpropane acrylic acid monoester or methacrylic acid monoester alone or as a mixture thereof and methacrylic acid-2-hydroxyethyl, methacrylic acid-2-hydroxypropyl, methacrylic acid-2-hydroxy A single component or a mixture selected from the group of methacrylic acid esters having active hydrogen such as butyl, methacrylic acid-3-hydroxypropyl, methacrylic acid-4-hydroxybutyl, etc. Acrylic acid esters such as ethyl acetate, isopropyl acrylate, acrylic acid-n-butyl, acrylic acid-2-ethylhexyl, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, methacrylate-n-butyl, isobutyl methacrylate, Methacrylic acid esters such as methacrylic acid-n-hexyl and lauryl methacrylate, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and itaconic acid, and unsaturated amides such as acrylamide, N-methylol acrylamide and diacetone acrylamide , And glycidyl methacrylate, styrene, vinyl toluene, vinyl acetate, acrylonitrile, dibutyl fumarate, vinyltrimethoxysilane, vinylmethyldimethoxysilane, γ- (meth) acryloxypropyltrimeth Examples include acrylic polyols obtained by polymerization in the presence or absence of a single or a mixture selected from the group of other polymerizable monomers such as vinyl monomers having a hydrolyzable silyl group such as xysilane.

  Polyether polyols were obtained by ring-opening polymerization of alkylene oxide to compounds having active hydrogen atoms in the presence of hydroxides such as lithium, sodium, potassium and cesium, cobasic catalysts such as alcoholates and alkylamines. A polyalkylene oxide is preferred.

  In addition, examples of polyether polyols include so-called polymer polyols obtained by polymerizing acrylamide or the like via polyalkylene oxide. Further examples include polytetramethylene glycol obtained by ring-opening polymerization of cyclic ether.

  Examples of the alkylene oxide include ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, and styrene oxide.

  As the compound having an active hydrogen atom, one type may be used, or two or more types may be used. The compound having an active hydrogen atom is preferably an organic compound having an active hydrogen atom, and more preferably a compound having a hydroxyl group or an amino group.

  Specific examples of the organic compound having a hydroxyl group as an active hydrogen atom include the aforementioned low molecular weight polyols having a molecular weight of less than 500. Since the number of hydroxyl groups of the resulting polyalkylene oxide is the same as the valence of the compound having an active hydrogen atom, trivalent to pentavalent polyhydric alcohols are preferable among the low molecular weight polyols to which alkylene oxide is added.

  Examples of the compound having an amino group as an active hydrogen atom include aliphatic amines, alicyclic amines, and aromatic amines. Aliphatic amines include alkylamines such as ethylenediamine, hexamethylenediamine, and diethylenetriamine. Alkanolamines such as monoethanolamine, diethanolamine, and triethanolamine. Examples of alicyclic amines include aminoethylpiperazine. Examples of aromatic amines include diaminotoluene.

Examples of the polyolefin polyol include polybutene having 2 or more hydroxyl groups, hydrogenated polybutadiene, polyisoprene, and hydrogenated polyisoprene. The number of hydroxyl groups (hereinafter referred to as the average number of hydroxyl groups) possessed by one statistical molecule of polyol is preferably 2-8. When the average number of hydroxyl groups is less than 2, it becomes difficult to reach the lower limit 3 of the average number n of isocyanate groups in the above formula (1), and the curability may be lowered. On the other hand, if it exceeds 8, the viscosity of the resulting polyisocyanate compound becomes very high, or if the molecular weight of the polyol is increased to reduce this viscosity, the coating film formed using the resulting fluorine-containing coating composition May cause a decrease in hardness. The average number of hydroxyl groups is preferably 3-5.
Examples of preferred polyols are the low molecular weight polyols and polyester polyols described above, more preferably polyester polyols, and most preferably polycaprolactone obtained by ring-opening polymerization of ε-caprolactone to the low molecular weight polyol. It is a polyol. Triol is preferred as the low molecular weight polyol.

  Moreover, 100-1000 are preferable, as for the number average molecular weight of a polyol, More preferably, it is 100-800, More preferably, it is the range of 150-500. When the number average molecular weight is less than 100, the average number of hydroxyl groups becomes small, so that it becomes difficult to reach the lower limit 3 of the average number n of isocyanate groups in the above formula (1) and / or the coating formed The flexibility of the film may be insufficient, and if the number average molecular weight of the polyol exceeds 1000, the hardness of the formed coating film may be reduced.

  The polyisocyanate compound represented by the above formula (1) used in the present invention is derived from at least one diisocyanate selected from aliphatic diisocyanates and alicyclic diisocyanates and one or more polyols.

  The diisocyanate consisting of at least one selected from the above aliphatic diisocyanates and alicyclic diisocyanates consists of diisocyanates consisting only of aliphatic diisocyanates, diisocyanates consisting only of alicyclic diisocyanates, combinations of aliphatic diisocyanates and alicyclic diisocyanates. In the present invention, from the viewpoint of shortening the curing and drying time, a diisocyanate comprising only an aliphatic diisocyanate, or a diisocyanate comprising a combination of an aliphatic diisocyanate and an alicyclic diisocyanate is preferred, and the resulting fluorine-containing coating composition. From the viewpoint of the hardness (tack-free) of the cured film of the product, a diisocyanate comprising a combination of an aliphatic diisocyanate and an alicyclic diisocyanate is more preferable. Arbitrariness.

  The diisocyanate consisting only of the aliphatic diisocyanate is preferably HDI, and the combination of the aliphatic diisocyanate and the alicyclic diisocyanate is preferably a combination of HDI and IPDI.

  When a diisocyanate comprising a combination of an aliphatic diisocyanate and an alicyclic diisocyanate is used as the diisocyanate, the diisocyanate residue constituting the polyisocyanate compound represented by the above formula (1) is an aliphatic diisocyanate residue / alicyclic ring. It is preferably a ratio of 95/5 to 50/50, more preferably a ratio of 90/10 to 60/40, in terms of the mass ratio indicated by the group diisocyanate residue. If this ratio exceeds 95/5, the hardness of the coating film formed from the resulting fluorine-containing coating composition may not be sufficient, and if it is less than 50/50, the resulting polyisocyanate compound becomes cloudy, The flexibility of the coating film obtained by the fluorine-containing coating composition containing may fall.

  The proportion of the polyol compound residue constituting the polyisocyanate compound represented by the above formula (1) is preferably 1 to 50% by mass, more preferably 3 to 30% by mass with respect to the total amount of the polyisocyanate compound. Preferably, it is 3 to 15% by mass. When this ratio is less than 1% by mass, the average number n of isocyanate groups tends to decrease, and when it exceeds 50% by mass, the compatibility with the above-mentioned fluorine-containing copolymer used in the fluorine-containing coating composition decreases. There is a case.

  In the polyisocyanate compound represented by the above formula (1) used in the present invention, the average number n of isocyanate groups is 3 to 20, preferably 4.5 to 20, and more preferably 4.5 to 15. When n is less than 3, the crosslinkability of the polyisocyanate compound is lowered. When n exceeds 20, compatibility with the fluorine-containing copolymer used in the fluorine-containing coating composition is lowered.

  As for the ratio of the isocyanate group in the polyisocyanate compound represented by the said Formula (1), 3-22 mass% is preferable with respect to the polyisocyanate compound whole quantity. If this proportion is less than 3% by mass, the urethane bond concentration in the coating film formed from the resulting fluorine-containing coating composition tends to decrease, and flexibility may decrease. The average number of isocyanate groups is difficult to increase, and the curability may be inferior.

  The number average molecular weight of the polyisocyanate compound represented by the above formula (1) is preferably 600 to 3000, and more preferably 600 to 1200. If it is less than 600, the average number n of isocyanate groups tends to decrease, and if it exceeds 3000, the viscosity of the polyisocyanate compound may increase.

  The viscosity of the polyisocyanate compound represented by the above formula (1) measured with an E-type viscometer is preferably 5,000 to 2,000,000 mPa · s / 25 ° C., more preferably 10,000 to 1,500, 000 mPa · s / 25 ° C. When the viscosity of the polyisocyanate compound is less than 5,000 mPa · s / 25 ° C., the lower limit 3 of the average number n of isocyanate groups may not be achieved. On the other hand, when the viscosity of the polyisocyanate compound exceeds 2,000,000 mPa · s / 25 ° C., the compatibility with the fluorine-containing copolymer used in the fluorine-containing coating composition may be lowered.

  The polyisocyanate compound represented by the above formula (1) used in the present invention is derived by reacting at least one diisocyanate selected from aliphatic diisocyanate and alicyclic diisocyanate with a polyol. In this reaction, it is preferable to use both the urethanization reaction of the isocyanate group of the diisocyanate and the hydroxyl group of the polyol and the isocyanurate reaction. After the isocyanuration reaction, the above polyol can be added to carry out the urethanation reaction. Preferably, the isocyanuration reaction is preferably carried out after the urethanization reaction in order to increase the average number n of isocyanate groups.

  Here, part or all of the urethane group formed before by the isocyanuration reaction becomes an allophanate group. The ratio between the allophanate bond and the urethane bond is preferably 10: 0 to 8: 2, more preferably 10: 0 to 9: 1, and most preferably no urethane bond is present. If the urethane bond exceeds the above ratio 8: 2, it may be difficult to achieve the lower limit 3 of the average number of isocyanate groups n required for the polyisocyanate compound.

  The ratio of the diisocyanate and the polyol in the case of reacting the diisocyanate and the polyol is appropriately adjusted by a conventionally known method so that the polyisocyanate compound represented by the above formula (1) is generated by the isocyanate group / hydroxyl group equivalent ratio. . In addition, conventionally known conditions can be applied to the reaction conditions. In producing the polyisocyanate compound represented by the above formula (1), it is preferable to perform an isocyanurate reaction after the urethanization reaction. Conventionally known conditions can also be applied to the reaction conditions including a catalyst for the isocyanuration reaction and the like (see Patent Documents 2 to 4).

  The polyisocyanate compound represented by the above formula (1) preferably has an isocyanurate group obtained by the above isocyanuration reaction. In that case, the isocyanurate trimer concentration is preferably 10% by mass or more, and more Preferably it is 20 mass% or more, More preferably, it is 30 mass% or more. When it does not have an isocyanurate group, the hardness of the coating film formed by the fluorine-containing coating composition containing the polyisocyanate compound obtained thereby tends to decrease, and when the isocyanurate trimer concentration is less than 10% by mass, The viscosity of the polyisocyanate compound tends to increase.

  In the production of the polyisocyanate compound represented by the above formula (1), the yield of the polyisocyanate compound is preferably selected from the range of 10 to 70% by mass, and more preferably 30 to 60% by mass. The viscosity of the polyisocyanate compound obtained in high yield is high.

  After the reaction is completed, the unreacted diisocyanate monomer is removed by a thin film evaporator, extraction or the like. In the composition containing the polyisocyanate compound represented by the above formula (1), the unreacted diisocyanate monomer concentration is 3% by mass. The content is preferably 1% by mass or less, more preferably 1% by mass or less, still more preferably 0.7% by mass or less, and particularly preferably 0.5% by mass or less. When blending the polyisocyanate compound represented by the above formula (1) with the fluorine-containing coating composition of the present invention, in consideration of workability, it is usually a polyisocyanate compound-containing composition containing the unreacted diisocyanate monomer. Although it mix | blends, when the unreacted diisocyanate monomer density | concentration exceeds 3 mass% with respect to the polyisocyanate compound containing composition whole quantity, the sclerosis | hardenability of a polyisocyanate compound may fall.

  The polyisocyanate compound represented by the above formula (1) used in the present invention can also be used as a polyisocyanate compound obtained by post-modifying a part of the isocyanate group with an active hydrogen-containing compound. In the present specification, the post-modification reaction means that after obtaining a polyisocyanate compound, a part of the isocyanate group is reacted with an active hydrogen-containing compound in order to impart the performance of the polyisocyanate composition. . An active hydrogen containing compound may be used independently and may use 2 or more types together. In this case, depending on the active hydrogen-containing compound to be used, the compatibility with the fluorine-containing copolymer that is blended in the fluorine-containing coating composition may be improved.

  When the post-modification reaction is performed with the active hydrogen-containing compound, the post-modification rate is preferably 5 to 30% of the isocyanate group in the polyisocyanate compound, and more preferably 5 to 20%. If it is less than 5%, the compatibility with the fluorine-containing copolymer blended with the fluorine-containing coating composition may be lowered. If it exceeds 30%, the coating film formed from the fluorine-containing coating composition Curability may not be sufficient.

The polyisocyanate compound represented by the above formula (1) used in the present invention can be used as a blocked polyisocyanate by blocking part or all of the isocyanate group with a conventionally known blocking agent.
As the blocking agent used in this case, a compound having one active hydrogen in the molecule is preferable. For example, alcohol, alkylphenol, phenol, active methylene, mercaptan, acid amide, acid imide, imidazole , Urea, oxime, amine, imide, and pyrazole compounds.

  In addition, as a polyisocyanate compound represented by the said Formula (1) used for this invention, since there exists a composition containing this in a commercial item, this can also be used. As a commercial item, for example, a product that meets the above conditions can be selected as appropriate from a product group of duranate (manufactured by Asahi Kasei Co., Ltd.). More specifically, examples of Duranate (manufactured by Asahi Kasei Corporation) include MHG-80B and MFA-75B used in the examples.

(3) Preparation of fluorine-containing coating composition The fluorine-containing coating composition of the present invention contains the fluorine-containing copolymer (1) and the polyisocyanate compound (2). In the fluorine-containing coating composition of the present invention, the fluorine-containing copolymer functions as a crosslinkable component, and the polyisocyanate compound functions as a curing agent. The hydroxyl group of the fluorine-containing copolymer and the isocyanate group of the polyisocyanate compound. React to form a coating film by crosslinking and curing.

  The blending ratio of (1) fluorine-containing copolymer and (2) polyisocyanate compound in the fluorine-containing coating composition of the present invention depends on (1) fluorine-containing copolymer and (2) polyisocyanate compound used. The ratio of the number of moles of the isocyanate group contained in the polyisocyanate compound to 1 mole of the hydroxyl group contained in the fluorine-containing copolymer (1) blended in the fluorine-containing coating composition is 0.3 to 2.0. Is more preferable, and 0.7 to 1.3 is more preferable. If this ratio is less than 0.3, the solvent resistance and wear resistance may be lowered, and if it exceeds 2.0, the weather resistance may be lowered.

  In the fluorine-containing coating composition of the present invention, as a curing agent, a melamine-based curing such as a complete alkyl type, a methylol group type alkyl, an imino group type alkyl, and the like, as long as the effects of the present invention are not impaired. It is also possible to add an agent.

  The fluorine-containing coating composition of the present invention may appropriately contain a medium and various additives as required in addition to the (1) fluorine-containing copolymer and the (2) polyisocyanate compound.

  The medium contained in the fluorine-containing coating composition is specifically a solvent or a dispersion medium. Examples of the fluorine-containing coating composition include: (1) a solution-type coating in which a fluorine-containing copolymer, (2) a polyisocyanate compound, and an arbitrarily blended additive are dissolved in a solvent; or (1) a fluorine-containing copolymer. And (2) a dispersion-type coating material in which a polyisocyanate compound and an arbitrarily blended additive are dispersed in a dispersion medium (however, depending on the type of additive, the additive is dissolved). The fluorine-containing paint composition is preferably a solution-type paint from the viewpoints of easy film formation, curability, good drying properties, and the like.

(A) Medium When the fluorine-containing paint composition is a solution-type paint, the medium is preferably a solvent, and more preferably an organic solvent.
Organic solvents include aromatic hydrocarbons such as toluene and xylene; alcohols such as ethanol and methanol; ketones such as methyl ethyl ketone, acetone and cyclohexanone; hydrocarbons such as mineral spirits and mineral terpenes; butyl acetate and ethyl acetate Etc. are preferred.

(B) Additive In the fluorine-containing coating composition of the present invention, various additives may be appropriately blended depending on the required characteristics within the range where the effects of the present invention are not impaired. Specific examples of such additives include curing catalysts, pigments, ultraviolet absorbers, light stabilizers, surface conditioners, pigment dispersants, antifoaming agents, thickeners, adhesion improvers, matting agents, and the like. .

  Examples of the curing catalyst include conventionally known tin compounds such as dibutyltin laurate, other metal chelate compounds such as aluminum chelate, organic acid compounds such as p-toluenesulfonic acid, inorganic acid compounds such as hydrochloric acid, and amino-based curing accelerators. The agent can be used. Although it depends on the curing accelerator used, the addition amount of the curing catalyst may be 7 to 20 ppm with respect to 100 parts by mass of the total mass of (1) fluorine-containing copolymer and (2) polyisocyanate compound. Preferably, it is more preferable to set it as 7-15 ppm.

  Moreover, you may add a pigment from the viewpoint of making the external appearance of a coated article beautiful, and protecting a base material sheet from an ultraviolet-ray. In particular, titanium oxide, which is a white pigment, is preferably used because of its high coloring power and high ultraviolet absorption ability. In addition, composite metals such as calcium carbonate, carbon black as a black pigment, and a Cu—Cr—Mn alloy are preferable. The amount of the pigment added is preferably 100 to 300 parts by mass with respect to 100 parts by mass of the total mass of (1) fluorine-containing copolymer and (2) polyisocyanate compound, although it depends on the pigment used. .

Further, the following compound X may be blended for the purpose of imparting low contamination and heat reflectivity.
(Compound X)
Compound X is a compound represented by the general formula Si (OY) ₄ (wherein Y may be the same or different and each represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) or a partial condensate thereof. It is.
By containing the compound X, it is possible to impart an effect of making the coating film hydrophilic and removing dirt adhered outdoors by rainwater.

When the carbon number of Y in the general formula exceeds 5, the effect of maintaining the heat ray reflection performance is lowered. Y is preferably an alkyl group having 1 or 2 carbon atoms because a particularly excellent heat ray reflection performance maintaining effect can be obtained. Particularly preferred compound X is tetramethoxysilane, tetraethoxysilane, or a partial condensate thereof.
Compound X preferably has a silica content of 20 to 60% by weight. If the silica content is too small, the effect of maintaining the heat ray reflection performance is lowered, and if it is too much, the storage stability is impaired.
The silica content is the ratio of the silica (SiO ₂ ) obtained when the compound X is 100% hydrolyzed and condensed with respect to the compound X.

The content of the compound X with respect to the resin solid content in the fluorine-containing coating composition is preferably 0.5 to 60% by mass, and more preferably 2 to 30% by mass. If the content of Compound X is too small, the effect of maintaining the heat ray reflection performance is lowered, and if it is too much, foam, sagging, leveling, etc. may occur and paintability may be inferior.
When compounding compound X in the present fluorine-containing coating composition, an accelerator may be included to advance the dealkoxy group reaction of compound X. Examples of the accelerator include the aforementioned curing catalyst.
Compound X and the accelerator may be added in advance to the curing agent (B) described later, or may be added when the main agent (A) and the curing agent (B) are mixed.

  The fluorine-containing coating composition of the present invention is transparent in the combination of the above (1) fluorine-containing copolymer and (2) polyisocyanate compound even when a clear film having high transparency is required as a cured coating film. In this case, an ultraviolet absorber or a light stabilizer is added as necessary to provide an ultraviolet absorption effect. As typical ultraviolet absorbers, benzophenol, triazine, and benzotriazole can be preferably used. As the light stabilizer, a hindered amine-based or phosphorus-based light stabilizer is preferably used. The required amount of the ultraviolet absorber added varies depending on the thickness of the cured coating film to be obtained. Specifically, it is preferable to add such a concentration that the ultraviolet transmittance at the film thickness of the formed cured coating film is less than 10%.

  The blending amounts of the various additives are 0.1 to 10% by mass for the ultraviolet absorber, 0.01 to 5% by mass for the light stabilizer, and 0 for the surface conditioner based on the total amount of the fluorine-containing coating composition. 0.01 to 1% by mass, pigment dispersant to 0.1 to 5% by mass, antifoaming agent to 0.01 to 3% by mass, thickener to 0.01 to 10% by mass, adhesion improver to 0.01 The amount of the matting agent is preferably 0.01 to 10% by mass.

  The thus-prepared fluorine-containing coating composition is a coating composition having a short curing and drying time at the time of forming the coating film, the resulting coating film having sufficient weather resistance and ensuring transparency. The fluorine-containing coating composition of the present invention can be used in the same manner as a normal cross-linking curable fluorine-containing coating composition. For example, apply the fluorine-containing coating composition on the surface of the article to be coated by usual methods such as roll coating, curtain flow coating, spray coating, electrostatic coating, bell coating, etc. dry. According to the fluorine-containing coating composition of the present invention, under the same curing and drying conditions, the curing and drying time is greatly shortened as compared with the conventional fluorine-containing coating composition, thereby improving workability and saving energy. It is possible to contribute to

  The fluorine-containing coating composition of the present invention is useful as a primer or top intermediate coating for metals such as steel sheets and surface-treated steel sheets, plastics, and inorganic materials, and further includes a pre-coated metal, automobile coating, and plastic containing a rust-proof steel sheet. It is useful for imparting cosmetic properties, weather resistance, acid resistance, rust resistance, chipping resistance, electrical insulation and the like to coatings.

[Two-component paint kit]
The two-component paint kit of the present invention has the hydroxyl group and carboxyl group described in the above (1), and has an acid value of 3 to 10 mg, from the viewpoint of long-term storage stability and stability of various properties of the fluorine-containing paint composition. Curing agent (A) comprising a composition containing a fluorine-containing copolymer of / KOH and a composition containing a polyisocyanate compound represented by the above formula (1) described in (2) above ( B).
The fluorine-containing copolymer in the main agent (A) is preferably the same as the fluorine-containing copolymer in the fluorine-containing coating composition of the present invention.
The polyisocyanate compound constituting the curing agent (B) is preferably the same as the polyisocyanate compound in the fluorine-containing coating composition of the present invention.

  The main agent (A) and the curing agent (B) may contain the medium and additives in addition to the essential component (1) fluorine-containing copolymer and (2) polyisocyanate compound, respectively. When the above-mentioned medium is contained in the composition of the main agent (A), aromatic hydrocarbons, ketones, hydrocarbons and esters are preferable, and the content is preferably 20 to 90% by mass. When the additive is contained in the composition of the main agent (A), the ultraviolet absorber is 0.1 to 10% by mass, the light stabilizer is 0.01 to 5% by mass, and the surface conditioner is 0.01 to 1% by mass. %, Pigment dispersant 0.1-5% by mass, antifoaming agent 0.01-3% by mass, thickener 0.01-10% by mass, adhesion improver 0.01-5% by mass, The matting agent is preferably 0.01 to 10% by mass. When the above medium is contained in the curing agent (B), aromatic hydrocarbons, ketones, hydrocarbons and esters are preferable, and the content is preferably 0.1 to 90% by mass.

  Further, in the curing agent (B), for the purpose of imparting low contamination and heat reflectivity, the above-mentioned compound X and an accelerator for promoting dealkoxy group reaction of the compound X and reticulation of molecules are added in the same amount as described above. You may mix with. The compound X and the accelerator may be added in advance to the curing agent (B), or may be added when the main agent (A) and the curing agent (B) are mixed.

  The blending amount of each component in the main agent (A) and the curing agent (B) includes the essential component, and when the main agent (A) and the curing agent (B) are combined, the (3) fluorine-containing coating composition This is the amount described in the preparation.

  In use, the two-component paint kit of the present invention is used in the same manner as the fluorine-containing paint composition of the present invention after sufficiently mixing the main agent (A) and the curing agent (B) with stirring.

  The present invention will be described below based on examples, but the present invention is not limited to these examples.

[Synthesis Example 1] Production of main agent (A1) Fluoro resin Lumiflon LF-400 [trade name, Asahi Glass Co., Ltd.], which is a copolymer of monomers containing chlorotrifluoroethylene, cyclohexyl vinyl ether, ethyl vinyl ether, hydroxyalkyl vinyl ether, and carboxyl group Manufactured, organic solvent solution containing hydroxyl group and carboxyl group-containing fluoroolefin copolymer (hydroxyl value: 47 mgKOH / g, acid value: 5 mgKOH / g) 60% by mass] to 69 g of methyl ethyl ketone 30 g and dibutyltin dilaurate 0.0008 g. In addition, the mixture was stirred to obtain the main agent (A) of the two-component paint kit.

[Synthesis Example 2] Preparation of main agent (A2) Fluoro resin Lumiflon LF-552, a copolymer of monomers containing chlorotrifluoroethylene, cyclohexyl vinyl ether, ethyl vinyl ether, hydroxyalkyl vinyl ether, and a carboxyl group [trade name, Asahi Glass 86 g of an organic solvent solution containing 40% by mass of a hydroxyl and carboxyl group-containing fluoroolefin copolymer (hydroxyl value: 52 mgKOH / g, acid value: 5 mgKOH / g) manufactured by the company, and 0.0008 g of methyl ethyl ketone 13 g and dibutyltin dilaurate Was added and stirred to obtain the main agent (A2) of the kit for two-component paint.

[Synthesis Example 3] Production of main agent (A3) Fluoro resin Lumiflon LF-936 [trade name, Asahi Glass Co., Ltd.], which is a copolymer of monomers containing chlorotrifluoroethylene, cyclohexyl vinyl ether, ethyl vinyl ether, hydroxyalkyl vinyl ether, and carboxyl group Organic solvent solution containing 65% by mass of hydroxyl group- and carboxyl group-containing fluoroolefin copolymer (hydroxyl value: 45 mgKOH / g, acid value: 2 mgKOH / g)], 53 g, methyl ethyl ketone 46 g, dibutyltin dilaurate, 0.0008 g Was added and stirred to obtain a main component (A3) of a two-component paint kit.

[Comparative Synthesis Example 1] Production of main agent (a1) Fluoro resin Lumiflon LF-200, a copolymer of chlorotrifluoroethylene, cyclohexyl vinyl ether, ethyl vinyl ether and hydroxyalkyl vinyl ether [manufactured by Asahi Glass Co., Ltd., hydroxyl group-containing fluoroolefin copolymer Organic solvent solution containing 60% by mass (hydroxyl value: 52 mgKOH / g, acid value: 0 mgKOH / g, mass average molecular weight 13000)] 47.4 g of methyl ethyl ketone and 0.0008 g of dibutyltin dilaurate are added to 57.4 g and stirred. The main component (a1) of the two-component paint kit was obtained.

[Comparative Synthesis Example 2] Production of main agent (a2) To 57 g of fluororesin Lumiflon LF-200, 16 g of methyl ethyl ketone, 0.0008 g of dibutyltin dilaurate and 27 g of titanium oxide (CR-90, manufactured by Ishihara Sangyo Co., Ltd.) were added and stirred. The titanium oxide was dispersed to about 10 μm with a sand mill to obtain a main component (a2) of a two-component paint kit.

[Curing agent (B1)]
Duranate MHG-80B containing a polyisocyanate compound (n: 5.4, isocyanate group concentration: 15.1% by mass) represented by the above formula (1) as a curing agent (B1) for a two-component paint kit (product) Name, manufactured by Asahi Kasei Co., Ltd.).

[Curing agent (B2)]
As a curing agent (B2) for a two-component paint kit, Duranate MFA-75B containing a polyisocyanate compound represented by the above formula (1) (n: 5.0, isocyanate group concentration: 13.7% by mass) (product) Name, manufactured by Asahi Kasei Co., Ltd.).

[(Comparison) Curing Agent (b1)]
Duranate THA-100 (trade name: manufactured by Asahi Kasei Co., Ltd., isocyanate group concentration: 19.7% by mass, average number of isocyanate groups: 3.5), which is an HDI-based isocyanurate, is used as a curing agent for a two-component paint kit (b1). Prepared as. The curing agent (b1) is a curing agent outside the scope of the present invention.

[Example 1]
To 100 g of the main agent (A1) obtained in Synthesis Example 1, 8 g of the curing agent (B1) was added and stirred to obtain a fluorine-containing coating composition. This fluorine-containing coating composition was coated on a transparent PET (polyethylene terephthalate) film with a bar coater so that the dry film thickness was about 10 μm, and at 80 ° C. for 1 minute or 2 minutes, at 100 ° C. for 1 minute. And drying at 120 ° C. for 1 minute. The following tack evaluation was performed immediately after the drying of the coating film returned to room temperature after completion of drying under each condition. About the coating film obtained on the drying conditions for 1 minute at 100 degreeC, the coating-film external appearance was evaluated. The results are shown in Table 1.

<Tack>
The stickiness of the coating film surface was observed with a finger and evaluated according to the following criteria.
A: No stickiness and no fingerprint trace. ○: There is no stickiness, but there is a fingerprint mark.
Δ: Slightly sticky. There is a fingerprint mark. ×: Remarkably sticky. There is a fingerprint mark.

<Appearance of coating film>
The transparency of the coating film dried at 100 ° C. for 1 minute was visually observed.
○: Transparent and free of cloudiness. Δ: There is cloudiness. X: Cloudiness is remarkable.

[Example 2]
To 100 g of the main agent (A1) obtained in Synthesis Example 1, 8.9 g of the curing agent (B2) was added and stirred to obtain a fluorine-containing coating composition. Using this fluorine-containing coating composition, a coating film was formed on a PET film in the same manner as in Example 1, and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 3]
To 100 g of the main agent (A2) obtained in Synthesis Example 2, 10.7 g of the curing agent (B1) was added and stirred to obtain a fluorine-containing coating composition. Using this fluorine-containing coating composition, a coating film was formed on a PET film in the same manner as in Example 1, and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 4]
To 100 g of the main agent (A3) obtained in Synthesis Example 3, 8.8 g of the curing agent (B1) was added and stirred to obtain a fluorine-containing coating composition. Using this fluorine-containing coating composition, a coating film was formed on a PET film in the same manner as in Example 1, and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Examples 1-4]
The combinations shown in Table 1 in which both or any of the main agent and the curing agent prepared in the above synthesis examples are out of the scope of the present invention are the amounts shown in Table 1, and the amounts of xylene shown in Table 1 as necessary. It added and mixed and the fluorine-containing coating composition of Comparative Examples 1-4 was produced. Using this fluorine-containing coating composition, a coating film was formed on a PET film in the same manner as in Example 1, and evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Comparative Examples 5 to 7]
To 100 g of the main agent (a2) prepared in Comparative Synthesis Example 2 above, 9.1 g of the curing agent (B1), 10 g of the curing agent (B1), 6.4 g of the curing agent (b1) and 1.3 g of xylene are added and stirred. And the fluorine-containing coating composition of Comparative Examples 5-7 was produced. Using this fluorine-containing coating composition, it was coated on a transparent PET (polyethylene terephthalate) film with a bar coater so as to have a dry film thickness of about 15 μm, and dried at 150 ° C. for 90 seconds. After drying, the next blocking resistance was evaluated immediately after the coating film returned to room temperature. The results are shown in Table 2.
<Blocking resistance>
A PET film is placed on a 7.5 cm × 13.5 cm coating film, and a weight is placed on the PTFE molding plate (30 cm × 30 cm) to adjust the total weight to 3.4 kg. It was. After standing for 17 hours, the PET film was peeled off from the coated surface, and the appearance of the coating surface was visually observed and evaluated according to the following criteria.
○: When the PET film was peeled off, it was easily peeled off.
Δ: Peeling of the coating film was observed. X: Could not be peeled off.

  As can be seen from Table 1, according to the fluorine-containing coating compositions of the examples, the curing and drying time at the time of forming the coating film is short, and the obtained coating film is also ensured in transparency.

  The fluorine-containing coating composition of the present invention is useful as a primer or top intermediate coating for metals such as steel sheets and surface-treated steel sheets, plastics, and inorganic materials, and further includes a pre-coated metal, automobile coating, and plastic containing a rust-proof steel sheet. It is useful for imparting cosmetic properties, weather resistance, acid resistance, rust resistance, chipping resistance, electrical insulation and the like to coatings.

Claims (8)

A fluorine-containing coating composition containing a fluorine-containing copolymer having a hydroxyl group and a carboxyl group and a polyisocyanate compound represented by the following formula (1), wherein the acid value of the fluorine copolymer is 1 to 12 mg / A fluorine-containing coating composition, which is KOH.
R- (NCO) n (1)
(In Formula (1), R is a residue except the isocyanate group in the polyisocyanate compound induced | guided | derived from the diisocyanate and polyol which consist of at least 1 sort (s) chosen from aliphatic diisocyanate and alicyclic diisocyanate, and n is the following. (It is calculated | required from Formula (2) and is 3-20.)

(In the above formula (2), the number average molecular weight is the number average molecular weight of the polyisocyanate compound.)   The diisocyanate residue constituting the polyisocyanate compound represented by the formula (1) is a ratio of 95/5 to 50/50 in terms of mass ratio represented by aliphatic diisocyanate residue / alicyclic diisocyanate residue. 2. The fluorine-containing coating composition according to 1.   The ratio of the polyol compound residue which comprises the polyisocyanate compound represented by said Formula (1) is 1-50 mass% with respect to the said polyisocyanate compound whole quantity, The fluorine-containing coating composition of Claim 1 or 2 .   The fluorine-containing coating composition according to any one of claims 1 to 3, wherein the fluorine-containing copolymer has a hydroxyl value of 20 to 200 mg / KOH.   The fluorine-containing copolymer is a polymer having a polymer unit based on at least one fluoroolefin selected from the group consisting of tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinylidene fluoride and vinyl fluoride. The fluorine-containing coating composition of any one of Claims 1-4. A two-component paint kit comprising the following main agent (A) and curing agent (B).
Main agent (A): A composition containing a fluorine-containing copolymer having a hydroxyl group and a carboxyl group and having an acid value of 3 to 10 mg / KOH.
Curing agent (B): A composition containing a polyisocyanate compound represented by the following formula (1).
R- (NCO) n (1)
(In Formula (1), R is a residue except the isocyanate group in the polyisocyanate compound induced | guided | derived from the diisocyanate and polyol which consist of at least 1 sort (s) chosen from aliphatic diisocyanate and alicyclic diisocyanate, and n is the following. (It is calculated | required from Formula (2) and is 3-20.)

(In the above formula (2), the number average molecular weight is the number average molecular weight of the polyisocyanate compound.)   The diisocyanate residue constituting the polyisocyanate compound represented by the formula (1) is a ratio of 95/5 to 50/50 in terms of mass ratio represented by aliphatic diisocyanate residue / alicyclic diisocyanate residue. The kit for two-component paints of 6.   The kit for two-component paint according to claim 6 or 7, wherein the ratio of the polyol residue constituting the polyisocyanate compound represented by the formula (1) is 1 to 50% by mass with respect to the total amount of the polyisocyanate compound.