WO2010035782A1

WO2010035782A1 - Fluoropolymer composition

Info

Publication number: WO2010035782A1
Application number: PCT/JP2009/066640
Authority: WO
Inventors: 俊齋藤; 康一佐々木; 祥増田
Original assignee: 旭硝子株式会社
Priority date: 2008-09-26
Filing date: 2009-09-25
Publication date: 2010-04-01
Also published as: JPWO2010035782A1; JP5510331B2

Abstract

Provided is a fluoropolymer composition which has a high storage stability over a long period of time without causing an increase in viscosity nor gelation due to water such as atmospheric moisture, even in the case where a large amount of a hydrolyzable silyl group has been introduced into the fluoropolymer or the resin composition has a high polymer concentration. A fluoropolymer composition which is extremely stable during storage over a long period of time can be obtained by adding a specific dehydrating agent and a specific hydroxyl group-containing compound to a solution of a fluoropolymer having a hydrolyzable silyl group.

Description

Fluoropolymer composition

The present invention relates to a fluorine-containing polymer composition that is useful as a fluororesin coating material and the like and is excellent in high weather resistance and storage stability.

Fluoropolymer paints are blends containing fluoropolymers and are excellent in weather resistance and UV resistance. In recent years, they have been used as maintenance-free high-performance paints for high-rise buildings, large structures, ships, vehicles, and houses. It is used for a wide range of purposes such as properties and bridges. In particular, fluoropolymers containing hydrolyzable silyl groups can be used as organosilane curing agents that are easy to handle as curing agents, so they can be used as fluororesins for environmentally friendly paints that have little impact on the global environment. Useful. In addition, when a fluorine-containing polymer containing a hydrolyzable silyl group is used as a raw material for a fluororesin coating, the coating film properties such as weather resistance, hardness, and water repellency are improved. It is also useful from the viewpoint of conversion.

However, the resin composition in which the hydrolyzable silyl group-containing fluorine-containing polymer is dissolved in an organic solvent has poor storage stability in the state before blending the curing agent, and thickens and gels during storage. The following methods have been proposed.
A method of containing a specific diketal compound in a moisture curable resin composition containing a polymer having a hydrolyzable silyl group (Patent Document 1).
A method of adding specific ketals and / or acetals to a resin composition containing a hydrolyzable silyl group-containing polymer and a curing catalyst (Patent Document 2).
A method of controlling the concentration of fluoride ions and chloride ions in an organic solvent solution of a fluorine-containing copolymer having a hydrolyzable silyl group to a certain concentration or less (Patent Document 3).

Japanese Patent Application Laid-Open No. 61-283657 Japanese Patent Laid-Open No. 01-048861 Japanese Patent Laid-Open No. 11-310672

The resin composition described in Patent Document 1 is only a hydrocarbon-based polymer containing a hydrolyzable silyl group, and there is no description regarding a fluorine-containing polymer containing a hydrolyzable silyl group. Moreover, the polymer composition used for evaluation has a solid content concentration of 50%, and there is no description regarding the case of a high solid content concentration.
The ketals and acetals in the resin composition described in Patent Document 2 are considered to function as a dehydrating agent, but the stability of the composition was insufficient only by adding them alone. In particular, when the content of the hydrolyzable silyl group in the polymer is large, or when the concentration of the resin in the composition is high, a problem that the stability is remarkably lowered is recognized.
Although the method of controlling the concentration of fluoride ions and chloride ions described in Patent Document 3 to a certain level or less is also described that the combined use of a dehydrating agent is preferred, it suppresses cationic polymerization and acetal condensation of residual monomer components. Although the effect of suppressing condensation and gelation of hydrolyzable silyl groups is low, the gelation of the polymer solution could not be suppressed for a long time.

In the present invention, even when the amount of the hydrolyzable silyl group introduced into the fluoropolymer is large or when the concentration of the polymer in the resin composition is high, the viscosity increases or gels due to moisture such as moisture in the air. An object of the present invention is to provide a fluorine-containing polymer composition that does not cause crystallization and has excellent long-term storage stability.

The present inventors have added a specific hydroxyl group-containing compound together with a specific dehydrating agent to a fluoropolymer containing a hydrolyzable silyl group. It has been found that a coalescence composition can be obtained.

That is, the gist of the present invention is the following [1] to [12].
[1] The following fluoropolymer (A), dehydrating agent (B), a hydroxyl group-containing compound (C) in which one or more hydrogen atoms of an aliphatic hydrocarbon compound having 1 to 6 carbon atoms are substituted with a hydroxyl group, and A fluorine-containing polymer composition comprising an organic solvent (D) (excluding a dehydrating agent (B) and a hydroxyl group-containing compound (C)).
Fluoropolymer (A): A fluoropolymer comprising a repeating unit (A1) based on a fluoroolefin and a repeating unit (A2) having a group represented by the following formula (1).
—OC (O) NH (CH ₂ ) _m SiX _n R _3-n (1)
(Wherein R represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, X represents an alkoxy group having 1 to 5 carbon atoms, n represents an integer of 1 to 3, and m represents an integer of 1 to 5). )
[2] A repeating unit (A2) is a polymerization unit obtained by polymerizing a monomer comprising a reaction product of a hydroxyl group of a hydroxyl group-containing monomer and an isocyanate group of a compound represented by the following formula (1a), or a hydroxyl group-containing monomer The fluorine-containing polymer composition according to [1], which is a unit obtained by reacting an isocyanate group of a compound represented by the following formula (1a) with a hydroxyl group of a polymerized polymer unit.
OCN (CH ₂ ) _m SiX _n R _3-n (1a)
(In the formula, R, X, n and m have the same meaning as described above.)
[3] 1.0 to 30.0 parts by mass of the dehydrating agent (B) and 1.0 to 30.0 parts by mass of the hydroxyl group-containing compound (C) with respect to 100 parts by mass of the fluoropolymer (A) The fluorine-containing polymer composition according to [1] or [2], which contains 10.0 to 100.0 parts by mass of the organic solvent (D).
[4] A repeating unit based on a monomer in which the fluoropolymer (A) is composed of a repeating unit (A1) and a repeating unit (A2) together with an alkyl group and a polymerizable unsaturated group connected by an ether bond or an ester bond. The fluorine-containing polymer composition according to any one of [1] to [3], which is a polymer that may contain (A3) and / or a repeating unit (A4) based on a hydroxyl group-containing monomer.
[5] The ratio of the repeating unit (A1) to the total content of the repeating unit (A1) and the repeating unit (A2) in the fluoropolymer (A) is 10 to 99 mol%, and the repeating unit (A2) And the sum of the repeating units (A1) and (A2) is 30 to the total content of all repeating units in the fluoropolymer (A). The fluoropolymer composition according to [4], which is 100 mol%, the proportion of the repeating unit (A3) is 70 to 0 mol%, and the proportion of the repeating unit (A4) is 30 to 0 mol%.

[6] Hydroxyl vinyl monomers, polyethylene glycol monovinyl ethers, hydroxyalkyl allyl ethers, polyethylene glycol monoallyl ethers, hydroxyalkyl carboxylic acid vinyl esters, hydroxyalkyl carboxylic acid allyl esters, (meta ) The fluoropolymer composition according to any one of [2] to [5], which is at least one monomer selected from the group consisting of hydroxyalkyl esters of acrylic acid and hydroxyalkyl esters of vinyl acetate. Here, (meth) acrylic acid indicates either acrylic acid or methacrylic acid.
[7] The fluorine-containing heavy component according to any one of [1] to [6], wherein the dehydrating agent (B) is at least one selected from the group consisting of ortho acid esters, acetals, and hemiacetals. Combined composition.
[8] The fluoropolymer composition according to any one of [1] to [7], wherein the organic solvent (D) is a weak solvent.

[9] One or more kinds of antioxidants (E) selected from the group consisting of phenolic antioxidants, phosphite antioxidants, and thioether antioxidants are added to 100 of the fluoropolymer (A). The fluoropolymer composition according to any one of [1] to [8], which is contained in an amount of 0.005 to 1.0 part by mass with respect to part by mass.
[10] The fluoropolymer composition according to any one of [1] to [9], wherein the content of the fluoropolymer (A) in the fluoropolymer composition is 40 to 90% by mass.
[11] The hydroxyl group-containing compound (C) is a compound represented by the general formula: R—OH (R represents a hydrocarbon group having 1 to 6 carbon atoms). The fluorine-containing polymer composition described.
[12] The fluorine-containing agent according to any one of [1] to [11], wherein the dehydrating agent (B) is trimethyl orthoformate, triethyl orthoformate, 1,1-dimethoxyethane, or 1-methoxy-1-ethanol. Polymer composition.

According to the present invention, a fluorine-containing polymer composition that is extremely stable even when stored for a long period of time is provided. Moreover, the coating material which mix | blended this fluoropolymer composition is also provided.

In this specification, a repeating unit obtained directly by polymerization and a repeating unit obtained by reacting another compound with the repeating unit obtained by polymerization are collectively referred to as “unit”. Further, the compound represented by the formula (1a) may be referred to as “compound (1a)”, and the group represented by the formula (1) may be referred to as “group (1)”. ) May be referred to as “fluoroolefin unit (A1)” or simply “unit (A1)”. Other units and monomers may be similarly described.

The fluorine-containing polymer composition of the present invention contains a fluorine-containing polymer (A), a dehydrating agent (B), a hydroxyl group-containing compound (C) having 1 to 6 carbon atoms, and an organic solvent (D). Moreover, you may contain antioxidant (E) as needed.

[Fluoropolymer (A)]
The fluorine-containing polymer (A) is a fluorine-containing polymer containing a unit (A2) having a unit (A1) of a fluoroolefin and a group (1). The fluoropolymer (A) is a unit of a monomer in which an alkyl group and a polymerizable unsaturated group are linked by an ether bond or an ester bond (hereinafter referred to as “alkyl group-containing monomer”) as an optional component. (A3), a hydroxyl group-containing monomer unit (A4), and other units may be included.

[Unit (A1)]
The unit (A1) is a fluoroolefin unit. A fluoroolefin is a compound in which one or more hydrogen atoms of an unsaturated hydrocarbon compound are substituted with fluorine atoms, and a part or all of the remaining hydrogen atoms may be substituted with chlorine atoms. It is a sex compound.
Of the hydrogen atoms, the number of hydrogen atoms substituted with fluorine atoms (hereinafter referred to as “fluorine addition number”) is preferably 2 or more, and more preferably 3 to 4. When the fluorine addition number is 2 or more, the weather resistance of the coating film is sufficient.

The fluoroolefin is preferably a fluoroolefin having 2 to 3 carbon atoms such as tetrafluoroethylene, chlorotrifluoroethylene, hexafluoropropylene, vinylidene fluoride, vinyl fluoride, etc., from the viewpoint of the weather resistance and solvent resistance of the coating film. Tetrafluoroethylene or chlorotrifluoroethylene (hereinafter referred to as “CTFE”) is more preferable.
The unit (A1) may be only one type or a combination of two or more types.

[Unit (A2) having group (1)]
The unit (A2) is a unit having a group (1). In the group (1) in the unit (A2), X is an alkoxy group having 1 to 5 carbon atoms, preferably an ethoxy group or a methoxy group. When the carbon number of X is within this range, the alcohol component produced by the condensation reaction is unlikely to remain in the cured coating film, and the water resistance and solvent resistance of the coating film are improved.

R is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably a monovalent hydrocarbon group.
The monovalent hydrocarbon group preferably has 1 to 5 carbon atoms, more preferably 1 or 2. Specifically, a methyl group or an ethyl group is preferable. When the carbon number of the monovalent hydrocarbon group is within this range, the group (1) does not become too bulky, and the condensation reaction of the alkoxy group (X) proceeds smoothly when the coating film is cured. When the condensation reaction of the alkoxy group (X) is sufficiently advanced, the coating film is sufficiently cured and the weather resistance is improved.
n is an integer of 1 to 3, preferably 2 or 3, and more preferably 3.
m is an integer of 1 to 5, preferably 2 to 5, and more preferably 2 to 4.

The group (1) includes a urethane-bonded nitrogen atom having the formula: — (CH ₂ ) ₃ Si (OCH ₃ ) ₃ , — (CH ₂ ) ₃ Si (OC ₂ H ₅ ) ₃ , — (CH ₂ ) ₃ Si (CH ₃ ) (OCH ₃ ) ₂ , — (CH ₂ ) ₃ Si (CH ₃ ) (OC ₂ H ₅ ) ₂ , — (CH ₂ ) ₃ Si (CH ₃ ) ₂ (OCH ₃ ), — (CH ₂ ) ₃ Si (CH ₃ ) ₂ (OC ₂ H ₅ ), — (CH ₂ ) ₄ Si (OCH ₃ ) ₃ , — (CH ₂ ) ₄ Si (OC ₂ H ₅ ) ₃ , — (CH ₂ ) ₂ A group to which a group represented by Si (OCH ₃ ) ₃ or — (CH ₂ ) ₂ Si (OC ₂ H ₅ ) ₃ is bonded is preferable.
Among these groups, since the raw materials are easily available, the nitrogen atom of the urethane bond has the formula: — (CH ₂ ) ₃ Si (OCH ₃ ) ₃ or — (CH ₂ ) ₃ Si (OC ₂ H ₅ ) A group to which a group represented by ₃ is bonded is more preferred.

The unit (A2) is a unit obtained by polymerizing a monomer comprising a reaction product of a hydroxyl group of a hydroxyl group-containing monomer and an isocyanate group of the compound (1a) represented by the following formula, or a unit obtained by polymerizing a hydroxyl group-containing monomer. It is preferably any unit obtained by reacting the isocyanate group of the compound (1a) with a hydroxyl group. In any case, the structure of the unit (A2) is determined by the type of the hydroxyl group-containing monomer and the compound (1a) to be combined.

OCN (CH ₂ ) _m SiX _n R _3-n (1a)
(In the formula, R, X, n, and m have the same meaning as described above.)

Examples of the hydroxyl group-containing monomer include hydroxyalkyl vinyl ethers such as hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, and cyclohexane dimethanol monovinyl ether; polyethylene glycol monovinyl ethers such as diethylene glycol monovinyl ether, triethylene glycol monovinyl ether, and tetraethylene glycol monovinyl ether. Hydroxyalkyl allyl ethers such as hydroxyethyl allyl ether, hydroxybutyl allyl ether, cyclohexane dimethanol monoallyl ether; polyethylene glycols such as diethylene glycol monoallyl ether, triethylene glycol monoallyl ether, tetraethylene glycol monoallyl ether Monoallylate Hydroxyalkyl vinyl esters such as hydroxyacetic acid vinyl ester, 3-hydroxypropionic acid vinyl ester, 4-hydroxybutyric acid vinyl ester, etc .; hydroxyacetic acid allyl ester, 3-hydroxypropionic acid allyl ester, 4-hydroxybutyric acid allyl ester Hydroxyalkylcarboxylic acid allyl esters such as (meth) acrylic acid hydroxymethyl ester, (meth) acrylic acid 2-hydroxyethyl ester, (meth) acrylic acid 3-hydroxypropyl ester, (meth) acrylic acid 1,4- (Meth) acrylic acid hydroxyalkyl esters such as cyclohexanedimethanol monoester; or vinyl acetic acid hydroxymethyl ester, vinyl acetic acid 2-hydroxyethyl ester, vinyl acetic acid 3 Hydroxypropyl esters, vinyl acetate hydroxyalkyl esters such as vinyl acetate 1,4-cyclohexanedimethanol mono-esters are preferred. However, (meth) acrylic acid shows either acrylic acid or methacrylic acid.
When the hydroxyl group-containing monomer is polyethylene glycol monovinyl ethers or polyethylene glycol monoallyl ethers, the number of multimerization is preferably 2 to 20, more preferably 2 to 15, and further preferably 2 to 10.

As the hydroxyl group-containing monomer, hydroxyalkyl vinyl ethers or polyethylene glycol monovinyl ethers are more preferable because they have excellent alternating copolymerization properties and good weather resistance of the formed coating film. Specifically, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, or diethylene glycol monovinyl ether is more preferable.
Only one type of hydroxyl group-containing monomer may be used, or two or more types may be used in combination.

In the compound (1a), preferred types of groups represented by R and X and preferred ranges of the values of n and m are the same as those in the case of the group (1).
That is, in the compound (1a), R is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms, and more preferably 1 or 2. Specifically, a methyl group or an ethyl group is preferable. X is an alkoxy group having 1 to 5 carbon atoms, preferably an ethoxy group or a methoxy group. n is an integer of 1 to 3, preferably 3, m is an integer of 1 to 5, and 2 to 4 is more preferable.

Examples of the compound (1a) include 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-isocyanatopropylmethyldimethoxysilane, 3-isocyanatepropylmethyldiethoxysilane, 3-isocyanatepropyldimethylmethoxysilane, 3- Isocyanatepropyldimethylethoxysilane, 4-isocyanatobutyltrimethoxysilane, 4-isocyanatobutyltriethoxysilane, 2-isocyanatoethyltrimethoxysilane, or 2-isocyanatoethyltriethoxysilane are preferred.
Since the compound (1a) is easily available, 3-isocyanatopropyltrimethoxysilane or 3-isocyanatepropyltriethoxysilane is more preferable.
Only 1 type may be used for a compound (1a) and it may use it in combination of 2 or more type.

The method for obtaining the unit (A2) is preferably any one of the following method (i) and method (ii).
<Method (i)>
Step (i-1): The reaction product is obtained by reacting the hydroxyl group of the hydroxyl group-containing monomer with the isocyanate group of the compound (1a).
Step (i-2): The monomer that is the reaction product of step (i-1) is copolymerized with the fluoroolefin and, if necessary, other monomers.
<Method (ii)>
Step (ii-1): A copolymer having a hydroxyl group in the side chain is obtained by copolymerizing a hydroxyl group-containing monomer, a fluoroolefin, and another monomer as required.
Step (ii-2): The isocyaninate group of compound (1a) is reacted with the hydroxyl group of the side chain of the copolymer obtained in step (ii-1).

When the method (i) is employed, the unit (A2) is a polymerized unit obtained by polymerizing a monomer composed of a reaction product of a hydroxyl group-containing monomer and the compound (1a).
Specific examples of the monomer include a reaction product of hydroxyethyl vinyl ether and 3-isocyanatopropyltrimethoxysilane, a reaction product of hydroxyethyl vinyl ether and 3-isocyanatopropyltriethoxysilane, hydroxybutyl vinyl ether and 3-isocyanatopropyl. Reaction product of trimethoxysilane, reaction product of hydroxybutyl vinyl ether and 3-isocyanatepropyl triethoxysilane, reaction product of diethylene glycol monovinyl ether and 3-isocyanatopropyltrimethoxysilane, or diethylene glycol monovinyl ether and 3- A reaction product with isocyanate propyltriethoxysilane is preferred.

Among these, the reaction product of hydroxyethyl vinyl ether and 3-isocyanatopropyltriethoxysilane due to the ease of monomer purification, the stability of the fluoropolymer (A), the compatibility with the curing agent component, and the reactivity A reaction product of hydroxybutyl vinyl ether and 3-isocyanatopropyltriethoxysilane, or a reactive organism of diethylene glycol monovinyl ether and 3-isocyanatopropyltriethoxysilane is more preferable.
The monomer used in the polymerization may be only one kind or a combination of two or more kinds.

When the method (ii) is employed, the unit (A2) is a unit in which the compound represented by the formula (1a) is reacted with the polymerization unit of the hydroxyl group-containing monomer.
Specific examples of the unit include a unit obtained by reacting a hydroxyethyl vinyl ether unit with 3-isocyanatopropyltrimethoxysilane, a unit obtained by reacting a hydroxyethyl vinyl ether unit and 3-isocyanatopropyltriethoxysilane, hydroxybutyl Units obtained by reacting vinyl ether units with 3-isocyanatopropyltrimethoxysilane, units obtained by reacting hydroxybutyl vinyl ether units with 3-isocyanatopropyltriethoxysilane, units of diethylene glycol monovinyl ether and 3-isocyanatopropyltrimethoxysilane A unit obtained by reacting silane or a unit obtained by reacting diethylene glycol monovinyl ether unit with 3-isocyanatopropyltriethoxysilane is preferred.

Among these, in view of stability of the fluoropolymer (A), compatibility with the curing agent component, and reactivity, a unit obtained by reacting a unit of hydroxyethyl vinyl ether and 3-isocyanatopropyltriethoxysilane, hydroxy A unit obtained by reacting a unit of butyl vinyl ether and 3-isocyanatopropyltriethoxysilane, or a unit of reacting a unit of diethylene glycol monovinyl ether and 3-isocyanatepropyltriethoxysilane is more preferable.

That is, in any of the methods (i) and (ii), the unit (A2) is a combination of hydroxyethyl vinyl ether and 3-isocyanatopropyltriethoxysilane, hydroxybutyl vinyl ether and 3-isocyanatepropyltriethoxysilane. Or a structure obtained by combining diethylene glycol monovinyl ether and 3-isocyanatopropyltriethoxysilane is more preferable.
Only one type of unit (A2) may be used, or a combination of two or more types may be used.

In the present invention, how to obtain the unit (A2) may be appropriately selected in consideration of ease of production, cost, etc., and the method (i) is polymerized to prevent gelation during production. It is more preferable to obtain the unit (A2) by the method (ii) from the viewpoint of ease of production, compared to the need to strictly control and manage the conditions.

The addition reaction between the hydroxyl group-containing monomer and the compound (1a) in the step (i-1) and the addition reaction between the hydroxyl group-containing copolymer and the compound (1a) in the step (ii-2) In a solvent containing no active hydrogen that reacts with the group (for example, ethyl acetate, methyl ethyl ketone, xylene, etc.), 0.1 to 10 moles, preferably 0.5 to 5 moles of compound (1a) per mole of hydroxyl group It is preferable to react at a molar ratio.
When the amount of the compound (1a) is more than 0.1 mol, a sufficient curing reaction occurs and the original performance of the coating film can be sufficiently exhibited. When the amount of the compound (1a) is less than 10 mol, the compound hardly remains in the coating film in a large amount as an unreacted product, and the water resistance and solvent resistance of the coating film are improved.

In step (i-1), the reaction between the hydroxyl group and the isocyanate group can be carried out with a yield of almost 100%. However, in order to increase the yield, if a catalyst is added or the reaction temperature is increased, the reaction product may be gelled. Therefore, the reaction may be performed under conditions where the conversion rate is lower than 100%. preferable. For example, the step (i-2) may be performed after removing the unreacted hydroxyl group-containing monomer from the reaction product, or the step (i-2) is performed while the reaction product still contains the unreacted hydroxyl group monomer. May be. However, it is preferable that the amount of unreacted hydroxyl group-containing monomer is small, and the compatibility with the dehydrating agent (B) is reduced by reducing the hydroxyl group content of the fluoropolymer (A) obtained in step (i-2). This improves the physical properties of the coating film, particularly the water resistance.

In step (ii-2), it is preferable that 50 mol% or more of the hydroxyl groups contained in the fluoropolymer (A) are modified by reacting with the isocyanate groups of the compound (1a). When it is 50 mol% or more, the compatibility between the fluoropolymer (A) obtained in step (ii-2) and the dehydrating agent (B) is good, and the physical properties of the coating film, particularly the water resistance, is good. improves. Although it is possible to modify 100 mol% of the hydroxyl group, the higher the amount of the compound (1a) used, the higher the cost. Therefore, a modification rate of 50 to 70 mol% is preferable from the viewpoint of cost.

When step (i-2) is carried out while containing the unreacted hydroxyl monomer in step (i-1) of method (i), and 100 mol% of the hydroxyl group in step (ii-2) of method (ii) When the amount is less than that of the compound (1a) and modified, the resulting fluoropolymer (A) becomes a polymer containing units based on a hydroxyl group-containing monomer.

In step (i-1) and step (ii-2), the addition reaction between a hydroxyl group and an isocyanate group is usually performed at room temperature to 100 ° C., preferably 50 to 70 ° C., under an inert atmosphere such as nitrogen. Is preferred. The reaction time can be appropriately changed according to the progress of the reaction, preferably 1 to 24 hours, particularly preferably 3 to 5 hours. In the addition reaction system, an organometallic catalyst such as an organotin compound, an organoaluminum compound, an organozirconium compound, or an organotitanate compound is preferably present for the purpose of promoting the reaction.

[Contents of Unit (A1) and Unit (A2) in Fluoropolymer (A))
The proportion of the unit (A1) in the fluoropolymer (A) is preferably from 10 to 99 mol%, more preferably from 30 to 95 mol%, based on the total content of the unit (A1) and the unit (A2). . When the proportion of the unit (A1) is less than 10 mol%, the weather resistance of the coating film is lowered, and when it exceeds 99 mol%, the adhesion with the substrate is lowered, which is not preferable.

The proportion of the unit (A2) in the fluoropolymer (A) is preferably from 1 to 90 mol%, more preferably from 5 to 70 mol%, based on the total content of the unit (A1) and the unit (A2). . When the unit (A2) is less than 1 mol%, the compatibility with the dehydrating agent (B) described later decreases, and a uniform coating film cannot be obtained. On the other hand, if it exceeds 90 mol%, the stability of the fluoropolymer (A) is lowered, and the pot life of the coating is lowered, which is not preferable.
The total content of the units (A1) and units (A2) in the fluoropolymer (A) is preferably from 30 to 100 mol%, more preferably from 50 to 100 mol%.

Fluoropolymer (A) in the present invention may optionally contain units other than units (A1) and units (A2). As units other than the unit (A1) and the unit (A2), a unit (A3) based on an alkyl group-containing monomer and / or a unit (A4) based on a hydroxyl group-containing monomer are preferable. Moreover, the other unit may be included as needed.

[Units based on alkyl group-containing monomer (A3)]
In the unit (A3) based on the alkyl group-containing monomer, the alkyl group-containing monomer has an alkyl group and a polymerizable unsaturated group linked by an ether bond or an ester bond (hereinafter referred to as “linked bond” by combining the ether bond and the ester bond). It is preferably a unit obtained by polymerizing the monomer.

The polymerizable unsaturated group is preferably an ethylenically unsaturated group such as a vinyl group, an allyl group, or a 1-propenyl group. The polymerizable unsaturated group and the linking bond preferably have a vinyl ether, allyl ether, vinyl ester, or allyl ester structure.
The alkyl group preferably has 3 to 16 carbon atoms, and more preferably has 3 to 10 carbon atoms. The structure of the alkyl group is preferably a linear alkyl group or a branched alkyl group, and may have a cyclic structure such as a cyclopentyl group or a cyclohexyl group in the molecule, and a branched alkyl group is more preferable. When a weak solvent described later is used as the organic solvent (D), a branched alkyl group having 3 to 10 carbon atoms is particularly preferable because the solubility of the fluoropolymer (A) in the solvent is good.

Monomers that form the unit (A3) by polymerization include vinyl ethers such as ethyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether, and cyclohexyl vinyl ether; allyl ethers such as ethyl allyl ether, butyl allyl ether, and cyclohexyl allyl ether; Vinyl esters such as vinyl acetate, vinyl pivalate, vinyl benzoate and vinyl versatate; allyl esters such as allyl acetate, allyl pivalate, allyl benzoate and allyl versatate are preferred. The monomer forming the unit (A3) is ethyl vinyl ether, 2-ethylhexyl, because the solubility of the fluoropolymer (A) in the solvent is improved when a weak solvent described later is used as the solvent (D). Vinyl ether or vinyl versatate is particularly preferred.

When the unit (A3) is contained in the fluoropolymer (A), the ratio of the unit (A3) to the whole unit is preferably 0 to 70 mol%, more preferably 0 to 65 mol%. The ratio of the unit (A3) being 0 mol% means that the unit (A3) is not included, and the lower limit when the unit (A3) is included is more than 0 mol%, and 0.01 mol% preferable. When the proportion of the unit (A3) is within this range, sufficient weather resistance of the coating film is ensured.
The unit (A3) may be only one type or a combination of two or more types.
A unit (A3) improves the adhesiveness of the coating film and base material of the coating material which were prepared from the polymer containing this unit, and gives a softness | flexibility to a coating film.

[Units based on hydroxyl group-containing monomer (A4)]
The preferable thing of the hydroxyl-containing monomer in the unit (A4) based on a hydroxyl-containing monomer is the same as the preferable thing of the hydroxyl-containing monomer used when forming the said unit (A2). The hydroxyl group-containing monomer in the unit (A4) based on the hydroxyl group-containing monomer is more preferably the same as the hydroxyl group-containing monomer used when forming the unit (A2).
As described above, the unit (A4) based on the hydroxyl group-containing monomer is subjected to the step (i-2) while containing the unreacted hydroxyl monomer in the step (i-1) of the method (i). In the step (ii-2) of ii), it is obtained by reacting with the isocyanate group of the compound (1a) to modify less than 100 mol% of the hydroxyl group, or a hydroxyl group-containing monomer separately during the polymerization of the fluoropolymer (A) It is preferable to obtain by adding and copolymerizing.

When the unit (A4) is contained in the fluoropolymer (A), the ratio of the unit (A4) to the whole unit is preferably 0 to 30 mol%. When the unit (A4) is included, the lower limit is more than 0 mol%, and preferably 0.01 mol%. If the ratio of a unit (A4) is this range, sufficient stability of a fluoropolymer (A) can be ensured, and the solubility to an organic solvent will also become favorable.
The unit (A4) may be only one type or a combination of two or more types.
The unit (A4) is effective in improving the adhesion with the substrate.

[Other units]
The fluoropolymer (A) in the present invention may contain other units in addition to the units (A1) to (A4) (hereinafter referred to as “other units”).
The monomer that forms the other unit is preferably a monomer composed of a non-fluorine compound, and is preferably a monomer having no hydrolyzable silyl group, hydroxyl group, alkyl vinyl ether group, or alkyl vinyl ester group. Specifically, non-fluorinated olefins such as ethylene, propylene, n-butene and isobutene; unsaturated carboxylic acids such as vinyl acetic acid and (meth) acrylic acid; vinyl benzoate, vinyl para-t-butylbenzoate, etc. Non-fluorinated aromatic group-containing monomers; nitrogen-containing monomers such as aminopropyl vinyl ether, diethylaminoethyl vinyl ether, 1-vinyl-2-pyrrolidone, 1-vinylimidazole, methacrylamide, acrylamide; vinyl phosphoric acid, vinyl phosphate dimethyl ester A phosphorus-containing monomer such as is preferable.
When other units are contained in the fluoropolymer (A), the ratio of the other units to the total units is preferably 0 to 5 mol%. Other units may be only one type or a combination of two or more types.

[Composition of Fluoropolymer (A)]
The fluoropolymer (A) in the present invention is a polymer containing the unit (A1) and the unit (A2) as essential units, and optionally containing the unit (A3), the unit (A4), and other units. It is preferable.

Preferred unit combinations include CTFE units / unit (A2) / polymer of alkyl vinyl ether units, CTFE units / unit (A2) / hydroxyalkyl vinyl ether units / alkyl vinyl ether units polymer, A polymer of CTFE units / unit (A2) / alkyl vinyl ester units is preferred. Moreover, the combination which contains 1 or more types of a unit (A3), a unit (A4), and another unit further in these combinations is also preferable.

The proportion of each unit constituting the fluorinated polymer (A) is the proportion of each monomer charged in the polymerization reaction for obtaining the fluorinated polymer (A), the reaction conditions, the fluorinated polymer (A) and the compound ( It can be changed depending on the charging ratio and reaction conditions when reacting 1a).

[Fluorine content of fluorine-containing polymerization (A)]
10 mass% or more is preferable, as for the fluorine content of the fluoropolymer (A) in this invention, 20 mass% or more is more preferable, and 25 mass% or more is further more preferable. When the fluorine content is large, the weather resistance of the paint becomes good.
On the other hand, the fluorine content of the fluoropolymer (A) is preferably 35% by mass or less. If the fluorine content is within this range, the solubility of the fluoropolymer (A) in the solvent can be sufficiently secured.

[Polymerization method of fluoropolymer (A)]
The step (i-2) and the step (ii-1) can be performed by a known method. For example, a normal radical polymerization method can be employed, and as the polymerization form, solution polymerization, suspension polymerization, emulsion polymerization, or the like can be employed.

The reaction temperature during the polymerization is appropriately changed depending on the radical polymerization initiator to be used, but it is usually preferably 0 to 130 ° C. The reaction time is preferably between 1 and 50.
Examples of the solvent include ion-exchanged water; alcohol solvents such as ethanol, butanol and propanol; saturated hydrocarbon solvents such as n-hexane and n-heptane; aromatic hydrocarbon solvents such as toluene and xylene; methyl ethyl ketone Ketone solvents such as cyclohexanone; ester solvents such as ethyl acetate and butyl acetate can be used.

Examples of the radical polymerization initiator include peroxydicarbonates such as diisopropyl peroxydicarbonate and di-n-propyl peroxydicarbonate; peroxydicarbonates such as t-hexyl peroxypivalate and t-butyl peroxypivalate. Oxyesters; ketone peroxides such as cyclohexanone peroxide and methyl ethyl ketone peroxide; 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, etc. Peroxyketals; peroxycarbonate esters such as t-hexylperoxy-n-butyl carbonate and t-butylperoxy-n-propyl carbonate; diacyl peroxides such as isobutyryl peroxide and lauroyl peroxide Id like; dicumyl peroxide, dialkyl peroxides such as di -t- butyl peroxide and the like can be used.

In the case of emulsion polymerization, polymerization can be carried out in water and in the presence of an anionic or nonionic emulsifier using an initiator such as a water-soluble peroxide, a persulfate, or a water-soluble azo compound.
In step (i-2), since a trace amount of hydrochloric acid or hydrofluoric acid may be generated during the polymerization reaction, it is preferably removed with a buffer after the polymerization reaction.

Examples of the copolymer having a hydroxyl group in the side chain obtained in step (ii-1) include Lumiflon (trade name, manufactured by Asahi Glass Co., Ltd.), Fluonate (trade name, manufactured by Dainippon Ink & Chemicals, Inc.), Commercially available fluororesins such as Central Glass Co., Ltd. (trade name), Zaflon (Toagosei Co., Ltd., trade name), Zaffle (Daikin Kogyo Co., Ltd., trade name) can also be used.

The fluorine-containing polymer (A) preferably has a number average molecular weight (Mn) of 5,000 to 20,000 as measured by gel permeation chromatography (GPC) using polystyrene as a standard substance. When Mn is 5000 or more, good weather resistance of the coating film is easily obtained. Moreover, when Mn exceeds 20000, the viscosity tends to increase. If the fluorine-containing polymer (A) has a high viscosity, a large amount of dilution solvent is required for coating (viscosity adjustment), which is not preferable from the viewpoint of environmental burden.

[Dehydrating agent (B)]
The dehydrating agent (B) contained in the fluoropolymer composition of the present invention is a component that is neither a hydroxyl group-containing compound (C) nor an organic solvent (D), and the fluoropolymer (A) is caused by moisture in the air. Is prevented from hydrolyzing the alkoxysilyl group contained therein.
As the dehydrating agent (B), ortho acid esters, acetals, or hemiacetals represented by the following formula (2) are preferable.
(R ¹ O) (R ² O) C (R ³ ) (Y) (2)
(R ¹ represents a linear or branched alkyl group having 1 to 5 carbon atoms. R ² and R ³ each represents a hydrogen atom or a linear or branched alkyl group having 1 to 5 carbon atoms. Y represents a hydrogen atom or an alkoxy group having 1 to 5 carbon atoms.)
The boiling point of the dehydrating agent is preferably 150 ° C. or less, more preferably 5 to 150 ° C. When the boiling point of the dehydrating agent (B) is within this range, the dehydrating agent (B) hardly remains in the coating film when the coating film is dried and cured, and the coating film can be formed in a short time.

Specific examples of the orthoesters include orthoformates such as trimethyl orthoformate, triethyl orthoformate and tripropyl orthoformate; orthoacetic esters such as trimethyl orthoacetate, triethyl orthoacetate and tripropyl orthoacetate; orthopropion Orthopropionic acid esters such as trimethyl acid, triethyl orthopropionate and tripropyl orthopropionate are preferred.

As the acetals, either a compound derived from a ketone compound or a compound derived from an aldehyde compound is preferred, but a compound derived from an aldehyde tends to have a high dehydration effect and is more preferred. As specific examples of acetals, dimethoxymethane, 1,1-dimethoxyethane, 1,1-dimethoxypropane, diethoxyethane, 1,1-diethoxyethane, 1,1-diethoxypropane and the like are preferable.

As the hemiacetals, both a compound derived from a ketone compound and a compound derived from an aldehyde compound are preferable, but a compound derived from an aldehyde tends to have a higher dehydration effect and is more preferable. Specific examples of hemiacetals include 1-methoxy-1-ethanol, 1-methoxy-1-propanol, 1-methoxy-1-butanol, 1-ethoxy-1-ethanol, 1-ethoxy-1-propanol, 1 -Ethoxy-1-butanol is preferred.

As the dehydrating agent (B), trimethyl orthoformate, triethyl orthoformate, 1,1-dimethoxyethane, or 1-methoxy-1-ethanol is more preferable because it is easily available.
The addition amount of the dehydrating agent (B) is preferably in the range of 1.0 to 30.0 parts by mass with respect to 100 parts by mass of the fluoropolymer (A). The range of 2.0 to 20.0 parts by mass is more preferable, and the range of 3.0 to 10.0 parts by mass is more preferable.

When the amount of the dehydrating agent (B) is 1.0 part by weight or more, gelation of the fluoropolymer composition can be suppressed due to a sufficient dehydrating effect. Moreover, if it is 30.0 parts by weight or less, curing is not hindered during coating, and poor curing of the coating film hardly occurs.
Only one type of dehydrating agent (B) may be used, or a combination of two or more types may be used.

[Hydroxyl-containing compound (C)]
The hydroxyl group-containing compound (C) having 1 to 6 carbon atoms contained in the polymer composition of the present invention suppresses dealcoholization reaction of alkoxysilyl group and generation of silanol group in the fluoropolymer (A), Prevents gelation due to condensation.
The hydroxyl group-containing compound (C) has 1 to 6 carbon atoms, more preferably 3 to 4 carbon atoms. Moreover, the alkyl chain part may have a linear structure or a branched structure.

The hydroxyl group-containing compound (C) is represented by the general formula: R—OH (R represents a hydrocarbon group having 1 to 6, preferably 1 to 4, more preferably 1 or 2 carbon atoms. The hydrocarbon group is an alkyl group. The compound represented by this is preferable. Specifically, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, pentanol, cyclopentanol, hexanol, or cyclohexanol is preferable.
The hydroxyl group-containing compound (C) is preferably methanol, ethanol, n-propanol, isopropanol, n-butanol, or hexanol from the viewpoint of availability and the effect of suppressing the dealcoholization reaction of alkoxysilyl groups. From the viewpoint of the volatilization rate in the drying / curing process, n-propanol, isopropanol, or hexanol is more preferable.

The addition amount of the hydroxyl group-containing compound (C) is preferably in the range of 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 fluoropolymer (A). More preferred is 3.0 to 10.0 parts by mass.
When the content of the hydroxyl group-containing compound (C) in the fluorine-containing polymer composition is less than 1.0 part by mass, the effect of suppressing the dealcoholization reaction of the alkoxysilyl group and the generation of silanol groups becomes low, and the heavy weight due to condensation is reduced. The coalescence composition is easily gelled. Moreover, even if it uses exceeding 30.0 mass parts, a remarkable difference will not be seen by the prevention effect of gelatinization.
Only one type of hydroxyl group-containing compound (C) may be used, or a combination of two or more types may be used.

[Organic solvent (D)]
The organic solvent (D) contained in the fluoropolymer composition of the present invention is not particularly limited as long as it is a compound other than the dehydrating agent (B) and the hydroxyl group-containing compound (C). For example, ketones such as acetone, methyl ethyl ketone, methyl propyl ketone, ethyl butyl ketone, diisobutyl ketone, cyclohexanone, isophorone; methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, t-butyl acetate Esters such as toluene, xylene, ethylbenzene, aromatic petroleum naphtha, tetralin, turpentine oil, aromatic hydrocarbons such as Solvesso # 100 (registered trademark of Exxon Chemical), Solvesso # 150 (registered trademark of Exxon Chemical); Ethers such as dioxan, tetrahydrofuran and cyclopentyl methyl ether; ether esters such as propylene glycol monomethyl ether acetate and methoxybutyl acetate; dimethyl sulfoxide, N, N-dimethylforma Aprotic polar solvents such as de, an organic solvent that is generally used can be used.

From the viewpoint of reducing the environmental load, a solvent that complies with the PRTR method and HAPs regulations, that is, an organic solvent that does not contain an aromatic is preferable. Moreover, the organic solvent classified into the 3rd type organic solvent in the classification | category of the organic solvent by the occupational safety and health law is also preferable.

Specifically, it is preferable to use ester solvents and ketone solvents that do not fall under the PRTR Law and HAPs regulations; paraffinic solvents and naphthenic solvents classified as third-class organic solvents.

When using a paraffinic solvent or a naphthenic solvent, it is preferable to use a commercially available weak solvent. Weak solvents are those classified as organic solvents in the classification of organic solvents according to the Industrial Safety and Health Act, and correspond to any of the following (1) to (3).
(1) Gasoline, coal tar naphtha (including solvent naphtha), petroleum ether, petroleum naphtha, petroleum benzine, turpentine oil, mineral spirit (including mineral thinner, petroleum spirit, white spirit and mineral turpentine).
(2) A mixture comprising two or more of (1).
(3) A mixture other than (1) and (1), containing (1) in excess of 5% by mass. However, the ratio of the first type organic solvent and the second type organic solvent is 5% by mass or less.

Examples of ketone solvents and ester solvents include ketones such as methyl ethyl ketone, diisobutyl ketone, cyclohexanone, and isophorone from the viewpoint of boiling point and resin solubility; or methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n Esters such as -butyl, isobutyl acetate and t-butyl acetate can be preferably used, but t-butyl acetate which does not correspond to the second type organic solvent is more preferable in the classification of organic solvents according to the Industrial Safety and Health Act.

The first type organic solvent is chloroform, carbon tetrachloride, 1,2-dichloroethane, 1,2-dichloroethylene, 1,1,2,2-tetrachloroethane, trichloroethane, carbon disulfide, and , A mixture composed solely of these, and a mixture other than these and containing more than 5% by mass.

The second type organic solvent includes acetone, isobutanol, isopropanol, isopentanol, ethanol, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-butyl ether, ethylene glycol monomethyl ether, ortho -Dichlorobenzene, xylene, cresol, chlorobenzene, isobutyl acetate, isopropyl acetate, isopentyl acetate, ethyl acetate, acetic acid-n-butyl, acetic acid-n-propyl, acetic acid-n-pentyl, methyl acetate, cyclohexanol, cyclohexanone, 1 , 4-dioxane, dichloromethane, N, N-dimethylformamide, styrene, tetrachloroethylene, tetrahydrofuran, 1,1,1-trichloroethane, toluene, n- Xane, 1-butanol, 2-butanol, methanol, methyl isobutyl ketone, methyl ethyl ketone, methyl cyclohexanol, methyl cyclohexanone, methyl-n-butyl ketone, and a mixture consisting of these alone, and a mixture other than these, Containing more than mass% (however, the ratio of the first type organic solvent is 5 mass% or less).
When a weak solvent contains the compound applicable to a hydroxyl-containing compound (C), this compound shall be included in a hydroxyl-containing compound (C), and shall calculate the total addition amount of a hydroxyl-containing compound (C).

As the weak solvent used in the present invention, it is preferable to use a solvent corresponding to the above (1) or (2), but when using a mixture corresponding to the above (3), use these third type organic solvents. It is preferable that the second type organic solvent corresponding to the strong solvent does not contain more than 5% by mass of the total solvent. A solvent having an aniline point of 30 ° C. to 70 ° C. is preferred. The lower limit of the aniline point is more preferably 40 ° C, and the upper limit of the aniline point is more preferably 60 ° C. When the aniline point exceeds 30 ° C., the old coating film is not affected, and if the aniline point is 70 ° C. or less, the fluorine-containing copolymer and polyisocyanate compound used in the present invention can be dissolved. The aniline point may be measured according to the aniline point test method described in JIS K 2256.

As the weak solvent, mineral spirit is preferable because its flash point is room temperature or higher. Solvents generally sold as mineral spirits include, for example, HAWS (manufactured by Shell Japan, aniline point 17 ° C.), Essonaphtha No. 6 (ExxonMobil Chemical Co., aniline point 43 ° C), LAWS (Shell Japan Co., aniline point 44 ° C), Pegasol 3040 (ExxonMobil Chemical Co., aniline point 55 ° C), A Solvent (Shin Nippon Petrochemical Co., Ltd.) Manufactured by Nippon Petrochemical Co., Ltd., aniline point 64 ° C.), mineral spirit A (manufactured by Nippon Petrochemical Co., Ltd., aniline point 43 ° C.), Hyalom 2S (manufactured by Nippon Petrochemical Co., Ltd., Aniline point 44 ° C.), Hyalom 2S (manufactured by Nippon Petrochemical Co., Ltd., aniline point 44 ° C.), linearene 10, linearene 12 (manufactured by Idemitsu Petrochemical Co., Ltd., α-olefin hydrocarbon, aniline point 44 ° C., 54 ° C.), Exol D30 (manufactured by ExxonMobil, naphthenic solvent, aniline point 63 ° C.), Ricasolve 900, 910B, 1000 (new day) Rika Co., hydrogenated C9 solvent, aniline point 53 ° C., 40 ° C., available as 55 ° C.) and the like. These can be used alone or in combination as the weak solvent used in the present invention.

When the fluoropolymer composition of the present invention contains a weak solvent as the organic solvent (D), the weak solvent is used as a polymerization solvent for the fluoropolymer (A), or polymerized in another solvent. After that, it is preferable to replace a part or all of the solvent or the dispersion medium with a weak solvent. Further, the concentration of the obtained composition may be adjusted as necessary, or other components may be added to the composition as necessary.

The content of the organic solvent (D) in the fluoropolymer composition of the present invention is appropriately determined in consideration of the solubility of the fluoropolymer (A), the appropriate viscosity when applied as a paint, the coating method, and the like. Is done. The content of the organic solvent (D) is preferably 10.0 to 100.0 parts by mass of the solvent organic solvent (D) with respect to 100 parts by mass of the fluoropolymer (A), and 25.0 to 100.0. Part by mass is more preferable.
The organic solvent (D) contained in the fluoropolymer composition of the present invention may be only one type or a combination of two or more types.

[Antioxidant (E)]
The fluoropolymer composition of the present invention may contain an antioxidant (E) as necessary. Antioxidant (E) inactivates the metal catalyst species used in the production of the polymer and prevents gelation due to condensation of alkoxysilyl groups.
As the antioxidant (E), a phenol-based antioxidant, a phosphite-based antioxidant, or a thioether-based antioxidant is preferable.

Specifically, 2-t-butyl-p-cresol, 2,6-di-t-butyl-p-cresol, 2,6-di-t-butyl-4-ethylphenol, 2,2′-methylenebis- (4-methyl-6-t-butylphenol, 2,2′-methylenebis- (4-ethyl-6-t-butylphenol, triethylene glycol-bis [3- (3-t-butyl-5-methyl-4- Hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], pentaerythrityltetrakis [3- (3 5-di-t-butyl-5-methyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-5-methyl-4-hydroxyphenyl) Phenolic antioxidants such as propionate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene; triphenyl phosphite, tris (2 , 4-di-t-butylphenyl) phosphite, etc .; or bis (4-hydroxy-3-methylphenyl) sulfide, bis (4-hydroxyphenyl) sulfide, 4,4′-thiobis -(6-t-butyl-m-cresol, 4,4'-thiobis- (6-t-butyl-о-cresol, 2,2'-thiobis- (4-t-octylphenol) and other thioether-based antioxidants Agents are preferred.
Of these antioxidants, 2-t-butyl-p-cresol or 2,6-di-t-butyl-p-cresol is more preferable because it is easily available.

The addition amount of the antioxidant (E) is preferably 0.005 to 1.0 part by mass, more preferably 0.01 to 0.5 part by mass with respect to 100 parts by mass of the fluoropolymer (A). 0.03-0.3 parts by mass is more preferable. When a plurality of types of antioxidants are used in combination, the total amount is preferably within the above range.
When the addition amount of the antioxidant (E) is 0.005 parts by mass or more, the catalyst is sufficiently inactivated and condensation of alkoxysilyl groups can be suppressed. Moreover, even if it uses exceeding 1.0 mass part, a remarkable difference will not be seen by the prevention effect of gelatinization.

Antioxidant (E) may be used alone or more preferably in combination of two or more. In particular, a large synergistic effect can be achieved by using a combination of a phenolic antioxidant and a phosphite antioxidant, or a combination of a phenolic antioxidant and a thioether antioxidant.
In addition, when a phenolic antioxidant is used, adding a metal chelating agent separately also exhibits a great synergistic effect in preventing gelation. As the metal chelating agent, acetylacetone, acetonylacetone, 2,2′-bipyridine, 1,10-phenanthroline and the like are preferable.

[Other additives]
If necessary, the fluoropolymer composition of the present invention may further contain additives such as a rheology control agent, a rust inhibitor, a leveling agent, an antifoaming agent, a light stabilizer, an ultraviolet absorber, and a surfactant. You may mix | blend. The compounding quantity of these components can be suitably selected in the range which does not impair the effect of this invention.

Examples of the rheology control agent include castor wax (also referred to as hardened castor oil or hydrogenated castor oil), polyolefin waxes such as beeswax and carnauba wax; stearic acid amide, hydroxystearic acid bisamide, m-xylylene bisstearic acid amide, N, N'-distearyl isophthalic acid amide, N, N'-distearyl sebacic acid amide, N, N'-distearyl adipic acid amide, butylene bishydroxystearic acid amide, hexamethylene bishydroxystearic acid amide, hexamethylene bis Henamide, hexamethylene bis stearamide, ethylene bis behenamide, ethylene bishydroxystearic amide, ethylene bis stearamide, ethylene bis laurate amide, ethylene Fatty acid amides such as scapric acid amide, ethylene biscaprylic acid amide, methylene bishydroxy stearic acid amide, methylene bis lauric acid amide, methylene bis stearic acid amide; N-butyl-N'-stearyl urea, N-phenyl-N'- Substituted urea waxes such as stearyl urea, N-stearyl-N′-stearyl urea, xylylene bisstearyl urea, toluylene bisstearyl urea, hexamethylene bisstearyl urea, diphenylmethane bisstearyl urea, diphenylmethane bislauryl urea; polyethylene glycol, polyethylene Polymer compounds such as oxide, methylcellulose, ethylcellulose, and hydroxyethylcellulose; or inorganic particles such as silica particles and kaolin particles are preferable.

Examples of rust inhibitors include triazole compounds such as benzotriazole and methylbenzotriazole; imidazole compounds such as imidazole, methylimidazole and 2,4,5-triphenylimidazole; or 1,3-diphenylguanidine The guanidine compound is preferred.

Leveling agents are trade names “Polyflow No. 7”, “Polyflow No. 50E”, “Polyflow No. 55”, “Polyflow No. 75”, “Polyflow No. 77”, “Polyflow No. 85”, “Polyflow No. 7” manufactured by Kyoeisha Chemical Co., Ltd. “S”, “Polyflow No. 90”, and trade names “Dispalon L-1980-50”, “Dispalon L-1982-50”, “Dispalon L-1983-50”, “Dispalon L-1984-50”, “Dispalon L” manufactured by Enomoto Kasei Co., Ltd. -1985-50, trade names "Surfinol 104", "Surfinol 420", "Surfinol 440", "Surfinol 465", manufactured by Air Products Japan, "BYK-300", "BYK-320", trade names manufactured by BYK-Chemie. Or the like.

The defoamers are trade names “Floren AC-300HF”, “Floren AC-326F”, “Floren AC-901HF”, “Floren AC-903HF”, “Floren AC-1190HF” manufactured by Kyoeisha Chemical Co., Ltd. Available as LAP-10, Disparon LAP-20, Disparon LAP-30, etc.

The light stabilizer is preferably a hindered amine light stabilizer. Specifically, trade names “MARX LA62” and “MARX LA67” manufactured by Adeka Argus Chemical Co., Ltd .; trade names “Cinuvin 292” manufactured by Ciba Specialty Chemicals, Inc. ”,“ Tinuvin 144 ”,“ Tinuvin-123 ”,“ Tinuvin 440 ”, etc.

As the ultraviolet absorber, benzophenone compounds, benzotriazole compounds, triazine compounds, cyanoacrylate compounds, and the like are preferable. The compounds are “Viosorb130”, “Viosorb582”, “Viosorb583” (manufactured by Kyodo Pharmaceutical Co., Ltd., trade name), “Tinuvin 320”, “Tinuvin 982”, “Tinuvin 1130”, “Tinuvin 400” (above, Ciba・ Available as Specialty Chemicals, trade name).

The surfactant may be any of nonionic type, cationic type or anionic type. The surfactants are: ROLEX ASE (Daiichi Kogyo Co., Ltd., trade name), Fluorosurfactant “Surflon” (Asahi Glass Co., trade name), Acrylic “Modaflow” (Monsanto Co., Ltd. Name), “Leo Fat” series (trade name, manufactured by Kao).

[Content of Fluoropolymerization (A) in Fluoropolymer Composition]
The content of the fluoropolymer (A) in the fluoropolymer composition of the present invention is preferably 40 to 90% by mass, more preferably 50 to 85% by mass, and further preferably 60 to 85% by mass.

[Paint using fluorinated polymer composition]
The fluorine-containing polymer composition of the present invention can be used as a highly weather-resistant varnish for a fluorine paint, and for example, can be used as a varnish for a lacquer paint. In addition, in order to ensure the strength of the coating film and anticorrosion performance over a long period of time, a curing agent, a curing catalyst, a pigment, other resins, additives, etc. are blended into the fluoropolymer composition of the present invention to form a paint. Can do.

As the curing agent, an isocyanate curing agent or an organosilane curing agent can be preferably used.
The isocyanate-based curing agent also includes a blocked isocyanate-based curing agent, specifically, 2,4-tolylene diisocyanate, diphenylmethane-4,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, lysine methyl ester diisocyanate, Preference is given to methylcyclohexyl diisocyanate, trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, their trimers, adducts and burettes thereof.

Examples of organosilane curing agents include tetrafunctional alkoxysilanes such as tetramethoxysilane, tetraethoxysilane, and tetraisopropoxysilane, and partial hydrolysis condensates thereof; methyltrimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane , Phenyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, trifluoropropyltrimethoxysilane, and other trifunctional alkoxysilanes and partial hydrolysis condensates thereof; or dimethyldimethoxysilane, diphenyldimethoxy Bifunctional alkoxysilanes such as silane, dimethyldiethoxysilane, and diphenyldiethoxysilane, and partial hydrolysis condensates thereof are preferable.

Moreover, you may contain a curing catalyst in order to accelerate | stimulate hardening reaction and to give favorable chemical performance and physical performance to hardened | cured material. In particular, when curing at a low temperature in a short time, it is preferable to contain a curing catalyst.
Curing catalysts include acidic phosphoric acid esters such as phosphoric acid monoesters and phosphoric acid diesters; acidic boric acid esters such as boric acid monoesters and boric acid diesters; addition reaction products of acidic phosphoric acid esters with amines, Amine adducts such as an addition reaction product of an acid compound and an amine; metal esters such as tin octylate and dibutyltin dilaurate; metal chelates such as tris (acetylacetonate) aluminum and tetrakis (acetylacetonate) zirconium; Metal alkoxides such as aluminum isopropoxide and titanium butoxide are preferred.

Examples of the pigment include inorganic pigments such as carbon black and titanium oxide, and organic pigments such as phthalocyanine blue, phthalocyanine green, quinacridone red, indanthrene orange, and isoindolinone yellow. The titanium oxide is preferably a surface-coated titanium oxide, and the titanium oxide can be obtained, for example, as Ishihara Sangyo Co., Ltd., trade name “PFC-105”; Sakai Chemicals, trade name “D-918”.

Other resins include acrylic resins, polyester resins, acrylic polyol resins, polyester polyol resins, urethane resins, acrylic silicone resins, silicone resins, alkyd resins, epoxy resins, oxetane resins, amino resins, and other non-fluorine resins. A fluororesin other than the fluoropolymer (A) is preferred. Other resins may have a reaction curable site.

Further, if necessary, a light stabilizer, an ultraviolet absorber, a matting agent, a surfactant, a leveling agent and the like may be appropriately added to the fluoropolymer composition of the present invention at the time of coating.

The fluorine paint containing the fluoropolymer composition of the present invention can be applied to various base materials, and the base material to be applied is not particularly limited; inorganic materials such as concrete, natural stone, and glass; iron, Examples include metals such as stainless steel, aluminum, copper, brass, and titanium; and organic substances such as plastic, rubber, adhesive, and wood. Moreover, FRP which is an organic inorganic composite material, resin reinforced concrete, fiber reinforced concrete, etc. are mentioned.

Fluorine paint containing the fluoropolymer composition of the present invention is preferably an undercoat paint, an intermediate paint, or a primer from the viewpoint of corrosion resistance and correlated adhesion. Specific examples of the undercoat paint and the intermediate coat paint include at least one synthetic resin selected from the group of epoxy resin, acrylic resin, chlorinated rubber, polyurethane resin, phenol resin, organopolysiloxane resin, and the like as necessary. Examples thereof include paints obtained by kneading color pigments, extender pigments, anti-settling agents, dispersants, curing agents, curing catalysts, reactive diluents, solvents and the like. Specific examples of the primer include a primer obtained by mixing an organopolysiloxane with a silane coupling agent or alkoxy titanium (or an oligomer thereof) as described in Japanese Patent Nos. 2991942 and 2914854. .

The primer is obtained by hydrolytic condensation of tetraalkoxy titanium in organopolysiloxane (a) having a three-dimensional siloxane skeleton having a triorganosilyl group as a main skeleton, water and t-butanol. A primer containing an organic titanium oligomer (b), a polyfunctional silane compound (c), or an acidic phosphate ester (d) having an acid value of 100 to 700 mgKOH / g is preferred.

The organopolysiloxane (a) is preferably an organopolysiloxane containing at least one triorganosiloxy unit and SiO ₂ unit represented by the following average composition formula (3).
(R ⁴ ) ₃ SiO _1/2 (3)
(R ⁴ represents a monovalent hydrocarbon group in which part or all of the hydrogen atoms may be substituted with a halogen atom, a cyano group or the like, and the three R ⁴ may be the same or different from each other. )
R ⁴ in formula (3) is, for example, an alkyl group such as a methyl group, an ethyl group or a propyl group; a cycloalkyl group such as a cyclopentyl group or a cyclohexyl group; an alkenyl group such as a vinyl group or an allyl group; An aralkyl group such as a benzyl group or a phenylethyl group; and a chloromethyl group in which some or all of the hydrogen atoms of these groups are substituted with a halogen atom, a cyano group, or the like; A group such as a 3-trifluoropropyl group or a cyanomethyl group is preferred. R ⁴ is more preferably a methyl group or a phenyl group.
Organopolysiloxanes (a) are trade names “KR-500”, “X-40-9225”, “X-40-9227”, “KR-510”, “KR-213”, “X-41-1056” manufactured by Shin-Etsu Chemical Co., Ltd. "X-41-1818", "X-40-9271", etc.

Examples of the organic titanium oligomer (b) include tetramethoxy titanium, tetraethoxy titanium, tetrapropoxy titanium, tetraisopropoxy titanium, tetrabutoxy titanium, tetra- (s-butoxy) titanium, tetra- (t-butoxy) titanium, and tetrapentyl. At least one selected from the group consisting of alkoxy titaniums such as oxytitanium, tetra (pentyl-2-oxy) titanium, tetra (pentyl-3-oxy) titanium, tetra- (t-pentyloxy) titanium, An organotitanium oligomer obtained by hydrolysis and condensation in t-butanol is preferred.
The organic titanium oligomer (b) can be obtained from Matsumoto Fine Chemical Co., Ltd. under the trade names “Orgachix PC-600”, “Orgachix PC-620”, “Orgachix PC-605” and the like.

Examples of the polyfunctional silane compound (c) include tetrafunctional alkoxysilanes such as tetramethoxysilane, tetraethoxysilane, and tetraisopropoxysilane, and partial hydrolysis condensates thereof; methyltrimethoxysilane, methyltriethoxysilane, phenyl Trifunctional alkoxysilanes such as trimethoxysilane, phenyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, trifluoropropyltrimethoxysilane, and their partial hydrolysis condensates; dimethyldimethoxysilane; Bifunctional alkoxysilanes such as diphenyldimethoxysilane, dimethyldiethoxysilane, and diphenyldiethoxysilane, and partial hydrolysis condensates thereof are preferable.

As acidic phosphate ester (d), the compound shown by following General formula (4) is preferable. The acid value of the acidic phosphate ester (d) is preferably an acid value of 100 to 700 mgKOH / g.
O = P (R ⁵ ) _q (OH) _3-q (4)
(R ⁵ represents an alkyl group, cycloalkyl group or aryl group having 3 to 10 carbon atoms. Q is 1 or 2.)
Specifically, primary alcohols such as n-propanol, n-butanol, n-hexanol, n-octanol, 2-ethylhexanol, and isopropanol, 2-butanol, 2-hexanol, 2-octanol, cyclohexanol And phosphoric acid monoesters or phosphoric acid diesters of secondary alcohols.
The acidic phosphate ester (d) may be used alone or in combination of two or more.
Acidic phosphate ester (d) is manufactured by Daihachi Chemical Industry Co., Ltd. under the trade names “AP-1”, “AP-4”, “DP-4”, “MP-4”, “AP-8”, “AP-10”, “MP-”. 10 "etc.

These primers may contain a resin component other than the organopolysiloxane, a leveling agent, an antifoaming agent, a dispersant, a solvent, an inorganic filler, and the like as necessary.

The selection of each component constituting the primer and the blending amount thereof may be appropriately selected and adjusted depending on the base material to be applied, etc., but the contact angle of the primer coating film with respect to the contact angle of the top coating film, It is preferable that each component is selected and blended and designed so that the range is ± 50 °.
If the contact angle of the primer coating is not in the range of ± 50 °, it is not preferable because it causes repelling when the top coat is applied, and even if there is no repelling, the adhesiveness may decrease.

The primer application method is not particularly limited, and it can be applied by a conventionally known application means such as a brush coating method, a spray coating method, a bar coating method, a flow coating method, a dipping method, or a casting method.
The substrate is not particularly limited, and metal, ceramic, glass, plastic, or the like can be used. In terms of improving adhesion, it is preferable to perform a pretreatment such as a degreasing treatment, a removal treatment, a polishing treatment, or a blasting treatment when using these substrates.
The primer coating film can be formed by applying at least one of a heat treatment and a light irradiation treatment after the primer is applied.

Fluorine paints containing the fluoropolymer composition of the present invention are used for transportation equipment such as automobiles, trains and aircraft; civil engineering members such as bridge members and steel towers; industrial equipment such as waterproof sheets, tanks and pipes; , Doors, window gate members, monuments, poles and other building materials; road median strips, guardrails, sound barriers, road members such as light-transmitting plates such as polycarbonate and acrylic; communication equipment; electrical and electronic parts; Furthermore, it can also be used for applications such as a solar cell backsheet paint and a solar cell surface protective paint.

Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to these examples.

In the following examples, the fluoropolymer (A) is referred to as component A, and the dehydrating agent (B) is referred to as component B. It describes similarly about another component.

<Production Example 1: Production of mineral spirit solution of fluoropolymer (α)>
According to the said method (ii), the fluoropolymer ((alpha)) was manufactured as follows.

In an autoclave with a stainless steel stirrer having an internal volume of 3000 mL, cyclohexyl vinyl ether (284.5 g), 2-ethylhexyl vinyl ether (202.9 g), hydroxybutyl vinyl ether (90.7 g), xylene (722 g), ethanol (189 g), Potassium carbonate (9.5 g) was added all at once, and dissolved oxygen was removed with nitrogen.

Next, chlorotrifluoroethylene (505 g) was introduced into the autoclave and the temperature was gradually raised. After reaching 65 ° C., a 50% xylene solution of t-butyl peroxypivalate (7 g) was added over 7 hours. The reaction was stopped after introduction into an autoclave and further stirring for 15 hours.

3-Isocyanatopropyltriethoxysilane (154.5 g) and tin octylate (0.5 g) are added to the xylene solution of the resulting hydroxyl group-containing fluoropolymer, and the reaction is carried out at 50 ° C. for 5 hours in a nitrogen atmosphere. went. Furthermore, the solvent substitution to mineral spirit was performed while evaporation to obtain a mineral spirit solution (nonvolatile content: 75.0%) of the fluoropolymer (α).

When the infrared absorption spectrum of the obtained solution was measured, the absorption peak observed in the isocyanate group absorption band was small, and conversely the large absorption peak was observed in the urethane bond absorption band. Formation of (α) was confirmed.
The composition of the obtained fluoropolymer (α) was as follows: CTFE units / cyclohexyl vinyl ether units / 2-ethylhexyl vinyl ether units / hydroxybutyl vinyl ether units / hydroxybutyl vinyl ether units hydroxyl group and 3-isocyanatopropyltrimethoxy Units reacted with isocyanate groups of silane = 50/26/15/4/5 mol%.

<Production Example 2: Production of t-butyl acetate solution of fluoropolymer (α)>
According to the said method (ii), the fluoropolymer ((alpha)) was manufactured as follows.

3-Isocyanatopropyltriethoxysilane (154.5 g) and tin octylate (0.5 g) are added to the xylene solution of the resulting hydroxyl group-containing fluoropolymer, and the reaction is carried out at 50 ° C. for 5 hours in a nitrogen atmosphere. went. Further, the solvent was replaced with t-butyl acetate while evaporating to obtain a t-butyl acetate solution (nonvolatile content: 75.0%) of the fluoropolymer (α).

When the infrared absorption spectrum of the obtained solution was measured, the absorption peak observed in the isocyanate group absorption band was small, and conversely the large absorption peak was observed in the urethane bond absorption band. Formation of (α) was confirmed.
The composition of the obtained fluoropolymer (α) was the same as that of the fluoropolymer (α) described in Production Example 1.

<Examples 1 to 11>
Examples 1 to 7 in Table 1 show examples, and Examples 8 to 11 in Table 2 show comparative examples.

Each component shown in Table 1 and Table 2 was blended in respective proportions and kneaded with a homogenizer. Next, this was filtered using a 300-mesh filter, and further degassed under reduced pressure at room temperature for 30 minutes to obtain the intended fluoropolymer composition. The obtained fluoropolymer composition was evaluated by the following storage stability test.

[Storage stability]
The fluoropolymer compositions of Tables 1 and 2 are stored for 1 month under the respective temperature conditions of humidity 50%, temperature 25 ° C., and 50 ° C., and thereafter, the fluoropolymer composition is measured with an E-type viscometer. The viscosity of was measured. The viscosity increase ratio with respect to the initial viscosity was calculated and evaluated according to the following criteria.

◎: Viscosity increase ratio is less than 1.1.

○: The viscosity increase ratio is 1.1 or more and less than 1.5.

Δ: Viscosity increase ratio is 1.5 or more.

X: The state in which the fluoropolymer composition is gelled and the viscosity cannot be measured.

("-" In the table indicates that the fluoropolymer composition does not contain the component.)

The present invention provides a fluorine-containing polymer composition excellent in storage stability that does not cause an increase in viscosity or gelation due to moisture such as moisture in the air.

The entire contents of the specification, claims, and abstract of Japanese Patent Application No. 2008-248129 filed on September 26, 2008 are incorporated herein as the disclosure of the specification of the present invention. Is.

Claims

The following fluorine-containing polymer (A), dehydrating agent (B), a hydroxyl group-containing compound (C) in which one or more hydrogen atoms of an aliphatic hydrocarbon compound having 1 to 6 carbon atoms are substituted with a hydroxyl group, and an organic solvent ( D) (excluding a dehydrating agent (B) and a hydroxyl group-containing compound (C)).
Fluoropolymer (A): A fluoropolymer comprising a repeating unit (A1) based on a fluoroolefin and a repeating unit (A2) having a group represented by the following formula (1).
—OC (O) NH (CH 2 ) m SiX n R 3-n (1)
(Wherein R represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, X represents an alkoxy group having 1 to 5 carbon atoms, n represents an integer of 1 to 3, and m represents an integer of 1 to 5). )
The repeating unit (A2) is a polymerized unit obtained by polymerizing a monomer comprising a reaction product of a hydroxyl group of a hydroxyl group-containing monomer and an isocyanate group of a compound represented by the following formula (1a), or a hydroxyl group-containing monomer is polymerized. The fluorine-containing polymer composition according to claim 1, which is a unit obtained by reacting a hydroxyl group of a polymer unit with an isocyanate group of a compound represented by the following formula (1a).
OCN (CH 2 ) m SiX n R 3-n (1a)
(In the formula, R, X, n and m have the same meaning as described above.)
1.0 to 30.0 parts by mass of the dehydrating agent (B), 1.0 to 30.0 parts by mass of the hydroxyl group-containing compound (C), and 100% by mass of the fluoropolymer (A). The fluoropolymer composition according to claim 1 or 2, comprising 10.0 to 100.0 parts by mass of (D).
The fluoropolymer (A) is a repeating unit (A3) based on a monomer in which an alkyl group and a polymerizable unsaturated group are linked by an ether bond or an ester bond together with the repeating unit (A1) and the repeating unit (A2) 4. The fluorine-containing polymer composition according to claim 1, which is a polymer that may contain a repeating unit (A4) based on a hydroxyl group-containing monomer.
The ratio of the repeating unit (A1) to the total content of the repeating unit (A1) and the repeating unit (A2) in the fluoropolymer (A) is 10 to 99 mol%, and the ratio of the repeating unit (A2) is 1 to 90 mol%, and the total of the repeating units (A1) and (A2) is 30 to 100 mol% with respect to the total content of all repeating units in the fluoropolymer (A). The fluoropolymer composition according to claim 4, wherein the proportion of the repeating unit (A3) is 70 to 0 mol% and the proportion of the repeating unit (A4) is 30 to 0 mol%.
Hydroxyl-containing monomers are hydroxyalkyl vinyl ethers, polyethylene glycol monovinyl ethers, hydroxyalkyl allyl ethers, polyethylene glycol monoallyl ethers, hydroxyalkyl carboxylic acid vinyl esters, hydroxyalkyl carboxylic acid allyl esters, (meth) acrylic acid 6. The fluorine-containing polymer composition according to claim 2, which is at least one monomer selected from the group consisting of hydroxyalkyl esters and vinyl acetate hydroxyalkyl esters. Here, (meth) acrylic acid indicates either acrylic acid or methacrylic acid.
The fluoropolymer composition according to any one of claims 1 to 6, wherein the dehydrating agent (B) is at least one selected from the group consisting of orthoesters, acetals, and hemiacetals.
The fluoropolymer composition according to any one of claims 1 to 7, wherein the organic solvent (D) is a weak solvent.
One or more antioxidants (E) selected from the group consisting of phenolic antioxidants, phosphite antioxidants, and thioether antioxidants are added to 100 parts by mass of the fluoropolymer (A). The fluoropolymer composition according to any one of claims 1 to 8, which is contained in an amount of 0.005 to 1.0 parts by mass.
The fluorine-containing polymer composition according to any one of claims 1 to 9, wherein the content of the fluorine-containing polymer (A) in the fluorine-containing polymer composition is 40 to 90% by mass.
11. The fluorinated heavy compound according to claim 1, wherein the hydroxyl group-containing compound (C) is a compound represented by the general formula: R—OH (R represents a hydrocarbon group having 1 to 6 carbon atoms). Combined composition.
The fluoropolymer composition according to any one of claims 1 to 11, wherein the dehydrating agent (B) is trimethyl orthoformate, triethyl orthoformate, 1,1-dimethoxyethane, or 1-methoxy-1-ethanol.