CN111004367B

CN111004367B - Polyisocyanate composition, coating composition and coating film

Info

Publication number: CN111004367B
Application number: CN201910930012.7A
Authority: CN
Inventors: 中西祐树; 原田佳司郎
Original assignee: Asahi Kasei Corp
Current assignee: Asahi Kasei Corp
Priority date: 2018-10-04
Filing date: 2019-09-29
Publication date: 2023-01-03
Anticipated expiration: 2039-09-29
Also published as: JP7206089B2; CN111004367A; JP2020059763A

Abstract

The present invention relates to a polyisocyanate composition, a coating composition and a coating film. The subject is to provide: a polyisocyanate composition which has low polarity and is excellent in gloss, distinctness of image, hardness and weather resistance when formed into a coating film. The solution is as follows: the polyisocyanate composition comprises the reaction product of a polyisocyanate and a modifier having an active hydrogen-containing group, the reaction product having an AA-SP value of 13.0 or less.

Description

Polyisocyanate composition, coating composition and coating film

Technical Field

The present invention relates to a polyisocyanate composition, a coating composition and a coating film.

Background

Conventionally, a urethane coating film formed from a polyurethane coating material has very excellent flexibility, chemical resistance, and stain resistance. In addition, a coating film using a non-yellowing polyisocyanate obtained from an aliphatic diisocyanate typified by hexamethylene diisocyanate (hereinafter, may be referred to as "HDI") as a curing agent is further excellent in weather resistance, and thus demand is increasing.

In recent years, further weatherability is required of polyurethane, and the use of a resin containing a component having high weatherability such as fluorine as a main agent is increasing. However, the polarity of the fluorine-containing main agent is low, and the selection of the curing agent is sometimes limited. In order to reduce the polarity, a method of using a polyisocyanate having an allophanate group as a curing agent has been developed so far (for example, refer to patent documents 1, 2 and 3).

Documents of the prior art

Patent document

Patent document 1: international publication No. 2009/130965

Patent document 2: international publication No. 2008/142848

Patent document 3: japanese patent application laid-open No. 2010-116509

Patent document 4: japanese patent laid-open publication No. 57-34107

Patent document 5: japanese patent laid-open publication No. Sho 61-275311

Disclosure of Invention

Problems to be solved by the invention

In the methods described in patent documents 1 to 3, although the compatibility with the fluorine-containing main agent is improved, there is room for improvement because the crosslinking density is lowered and the weather resistance and the coating film hardness are deteriorated.

The present invention has been made in view of the above circumstances, and provides: a polyisocyanate composition having low polarity and good gloss, image clarity, hardness and weatherability when formed into a coating film, and a coating composition and a coating film using the polyisocyanate composition.

Means for solving the problems

That is, the present invention includes the following aspects.

The polyisocyanate composition according to claim 1 of the present invention comprises a reaction product of a polyisocyanate and a modifier having an active hydrogen-containing group, and the reaction product has an AA-SP value of 13.0 or less.

In the polyisocyanate composition according to claim 1, the polyisocyanate may satisfy the following (a) and (B).

(A) A diisocyanate derived from at least 1 diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, and a monohydric alcohol having 1 or more carbon atoms and 20 or less carbon atoms;

(B) The molar ratio of allophanate groups to isocyanurate groups is 0/100 or more and 25/75.

The polyisocyanate may further satisfy the following (C).

(C) Having structural units derived from hydrophilic compounds

The hydrophilic compound may be a nonionic hydrophilic compound including a repeating unit of 1 or more hydroxyl groups and 1 or more and 50 or less oxyethylene groups.

The modifier having an active hydrogen-containing group may be a compound represented by the following general formula (1) or a compound represented by the following general formula (2).

H-(Y ¹¹ ) _m11 -X ¹¹ (1)

R ²¹ -((Y ²¹ ) _m21 -X ²¹ ) _n21 (2)

(in the general formulae (1) and (2), n21 is an integer of 1 to 10 inclusive, m11 and m21 are each independently a number of 1 to 300 inclusive, R ²¹ Is a saturated hydrocarbon group having n21 valency and having 1 to 20 carbon atoms. R is ²¹ In the case of a saturated hydrocarbon group having 2 or more carbon atoms, a part of the carbon-carbon bond is optionally replaced with an ether bond or an ester bond. Y is ¹¹ And Y ²² Each independently is methylene or [ -O-R' -]And (4) a base. R' is an alkylene group having 1 to 4 carbon atoms. Y is ¹¹ And Y ²¹ Is [ -O-R' -]And when m11 and m21 are 2 or more, plural Y's are present ¹¹ And Y ²¹ Optionally of the same kind or of a different kind. X ¹¹ And X ²¹ Each independently an active hydrogen-containing group. )

The aforementioned X ¹¹ May be a hydroxyl group.

Part or all of the isocyanate groups of the reaction product may be blocked by a blocking agent.

The aforementioned blocking agent may be at least 1 compound selected from the group consisting of methyl ethyl ketoxime and 3, 5-dimethylpyrazole.

The coating composition of claim 2 of the present invention comprises: the polyisocyanate composition according to claim 1, and a polyol having a hydroxyl value of not less than 10mgKOH/g and not more than 200 mgKOH/g.

The polyol may contain a fluorinated polyol.

The coating film according to claim 3 of the present invention is obtained by curing the coating composition according to claim 2.

ADVANTAGEOUS EFFECTS OF INVENTION

The polyisocyanate composition according to the above aspect can provide: a polyisocyanate composition having low polarity and good gloss, image clarity, hardness and weatherability when formed into a coating film. According to the coating composition of the above aspect, a coating film excellent in gloss, distinctness of image, hardness and weather resistance can be obtained. According to the coating film of the above aspect, a coating film excellent in gloss, distinctness of image, hardness and weather resistance can be provided.

Detailed Description

Hereinafter, a mode for carrying out the present invention (hereinafter, simply referred to as "the present embodiment") will be described in detail. The following embodiments are examples for illustrating the present invention, and the present invention is not intended to be limited to the following. The present invention can be suitably modified and implemented within the scope of the gist thereof.

In the present specification, the "polyisocyanate" refers to a polymer to which a plurality of monomers having 1 or more isocyanate groups (-NCO) are bonded.

In the present specification, the term "polyol" refers to a compound having 2 or more hydroxyl groups (-OH).

Polyisocyanate composition

The polyisocyanate composition of the present embodiment comprises the reaction product of a polyisocyanate and a modifier having an active hydrogen-containing group. The reaction product is obtained by reacting an isocyanate group of a polyisocyanate with an active hydrogen-containing group of a modifier having an active hydrogen-containing group, and is a modified polyisocyanate having a structural unit derived from the modifier (a residue of the modifier other than the active hydrogen-containing group).

In the polyisocyanate composition of the present embodiment, the AA-SP value of the reaction product (modified polyisocyanate) is 13.0 or less, and thus the polyisocyanate composition has low polarity and is excellent in gloss, distinctness of image, hardness, and weather resistance when formed into a coating film.

On the other hand, the lower limit of the AA-SP value is not particularly limited, and may be, for example, 10 or more.

In the present specification, the term "AA-SP value" means an SP value obtained by titration, and is measured using acetic acid as a good solvent, water and hexane as a poor solvent. The detailed measurement method is shown in the examples described later.

The respective constituent components of the polyisocyanate composition of the present embodiment will be described in detail below.

< modifying agent having active Hydrogen-containing group >

The modifying agent having an active hydrogen-containing group used for producing the modified polyisocyanate is preferably a compound represented by the following general formula (1) (hereinafter, sometimes referred to as "compound (1)") or a compound represented by the following general formula (2) (hereinafter, sometimes referred to as "compound (2)") from the viewpoint of polarity.

H-(Y ¹¹ ) _m11 -X ¹¹ (1)

R ²¹ -((Y ²¹ ) _m21 -X ²¹ ) _n21 (2)

(in the general formulae (1) and (2), n21 is an integer of 1 to 10 inclusive, m11 and m21 are each independently a number of 1 to 300 inclusive, R ²¹ Is a saturated hydrocarbon group having n21 valency and having 1 to 20 carbon atoms. R ²¹ In the case of a saturated hydrocarbon group having 2 or more carbon atoms, a part of the carbon-carbon bond is optionally replaced with an ether bond or an ester bond. Y is ¹¹ And Y ²¹ Each independently is methylene or [ -O-R' -]And (4) a base. R' is an alkylene group having 1 to 4 carbon atoms. Y is ¹¹ And Y ²¹ Is [ -O-R' -]And when m11 and m21 are 2 or more, plural Y's are present ¹¹ And Y ²¹ Optionally of the same or different kind. X ¹¹ And X ²¹ Each independently an active hydrogen-containing group. )

[n21]

n21 is R ²¹ The number of the connecting bonds of (2) is an integer of 1 to 10 inclusive. Among them, n21 is preferably 1 or more and 5 or less, more preferably 1 or more and 3 or less.

[ m11 and m21]

m11 and m21 are each Y ¹¹ And Y ²¹ The number of repetitions (degree of polymerization) of (a). The modifier having an active hydrogen-containing group may be a single component or an aggregate of substances having different numbers of m11 and m 21. Thus, m11 and m21 represent the average values of the polymerization degrees.

m11 and m21 are each independently 1 or more and 300 or less, preferably 2 or more and 300 or less, more preferably 4 or more and 270 or less, further preferably 8 or more and 250 or less, particularly preferably 10 or more and 200 or less. When m11 and m21 are not less than the lower limit, the gloss when forming a coating film is further improved. On the other hand, when m11 and m21 are not more than the above upper limit, gloss and image clarity in forming a coating film become better.

[R ²¹ ]

R ²¹ Is a saturated hydrocarbon group having n21 valences, that is, 1 to 10 valences, having 1 to 20 carbon atoms inclusive. R ²¹ In the case of a saturated hydrocarbon group having 2 or more carbon atoms, a part of the carbon-carbon bond is optionally replaced with an ether bond or an ester bond.

Wherein R is ²¹ The saturated hydrocarbon group having a valence of 1 to 3 of 1 or more and 20 or less is preferable.

The saturated hydrocarbon group having a valence of 1 to 20 inclusive, that is, the alkyl group having 1 to 20 inclusive, may be a chain or a ring, and is preferably a chain. The chain may be linear or branched. The number of carbon atoms is preferably 1 or more and 15 or less, more preferably 1 or more and 10 or less, and still more preferably 1 or more and 8 or less. Examples of such an alkyl group include a methyl group, an ethyl group, a 1-propyl group, a 1-methylethyl group, a 1-butyl group, a 1-methylpropyl group, a 2-methylpropyl group, a1, 1-dimethylethyl group, a 1-pentyl group, a 1-hexyl group, a 1-heptyl group, a 1-octyl group, a 2-methylhexyl group, a 1-nonyl group, and a 1-decyl group.

Wherein R is ²¹ In the case of an alkyl group having 1 to 20 carbon atoms, R ²¹ Methyl or 2-ethylhexyl is preferred.

The hydrocarbon group having 2-valent carbon atoms of 1 to 20 carbon atoms is preferably a linear alkylene group, and specific examples thereof include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group.

The hydrocarbon group having 3-valent carbon atoms of 1 to 20 carbon atoms is preferably a straight chain alkanetriyl group, and specific examples thereof include a methanetriyl group, an ethanetriyl group, a propanetriyl group, a butanetriyl group, a pentanediyl group, and a hexanetriyl group.

Wherein R is ²¹ Is a hydrocarbon group having 2-or 3-valent carbon atoms of 1 to 20 carbon atomsIn the case of R ²¹ Preferably propanetriyl.

[Y ¹¹ And Y ²¹ ]

Y ¹¹ And Y ²¹ Each independently is methylene or [ -O-R' -]And (4) a base. R' is an alkylene group having 1 to 4 carbon atoms. R' may be linear or branched. Specific examples of R' include a methylene group (-CH) ₂ -), ethylene (- (CH) ₂ ) ₂ -) trimethylene group (-CH ₂ CH ₂ CH ₂ -), propylene (-CH (CH) ₃ )CH ₂ -), tetramethylene (-CH) ₂ CH ₂ CH ₂ CH ₂ -), butylene (-CH (CH) ₃ )CH ₂ CH ₂ -) and the like.

Y ¹¹ And Y ²¹ Is [ -O-R' -]And when m11 and m21 are 2 or more, plural Y's are present ¹¹ And Y ²¹ Optionally of the same or different kind.

In addition, Y ¹¹ And Y ²¹ When m11 and m21 are 2 or more, a group represented by formula (II) - (Y) ¹¹ ) _m11 -or- (Y) ²¹ ) _m21 The alkylene group may be a linear alkylene group or a branched alkylene group, and is preferably a linear alkylene group.

Wherein, Y ¹¹ And Y ²¹ Preferably methylene, [ -O- (CH) ₂ ) ₂ -]Radical (oxyethylene) or [ -O-CH (CH) ₃ )CH ₂ -]And (oxypropylene).

[X ¹¹ ]

X ¹¹ Is an active hydrogen-containing group. Examples of the active hydrogen-containing group include a hydroxyl group, an amino group, and a mercapto group. Wherein, X ¹¹ Hydroxyl groups are preferred.

Preferable examples of the compound (1) include a compound represented by the following general formula (1-1) (hereinafter, sometimes referred to as "compound (1-1)"), a compound represented by the following general formula (1-2) (hereinafter, sometimes referred to as "compound (1-2)"), and the like.

Examples of the preferable compound (2) include a compound represented by the following general formula (2-1) (hereinafter, may be referred to as "compound (2-1)"), and the like.

These compounds are examples of the preferable compound (1) or compound (2), and the preferable compound (1) or compound (2) is not limited to these compounds.

H-(CH ₂ )m ₁₁₁ -OH (1-1)

H-(O-R ¹²¹ ) _m121 -OH (1-2)

R ²¹¹ -((O-R ²¹² ) _m211 -OH) _n211 (2-1)

(in the general formula (1-1), m111 is 1 or more and 300 or less.

In the general formula (1-2), m121 is 1 or more and 300 or less. R ¹²¹ Is an alkylene group having 1 to 4 carbon atoms.

In the general formula (2-1), m211 is 1 or more and 300 or less. n211 is an integer of 1 to 3 inclusive. R ²¹¹ A saturated hydrocarbon group having n211 valency and having 1 to 8 carbon atoms. R is ²¹² Is an alkylene group having 1 to 4 carbon atoms. )

[ m111, m121, and m211]

m111, m121, and m211 are each independently 1 or more and 300 or less, preferably 2 or more and 300 or less, more preferably 4 or more and 270 or less, further preferably 8 or more and 250 or less, particularly preferably 10 or more and 200 or less.

[n211]

n211 is an integer of 1 or more and 3, preferably 1 or 3.

[R ²¹¹ ]

R ²¹¹ Is a saturated hydrocarbon group having n211, that is, 1 to 3 valences and having 1 to 8 carbon atoms, preferably an alkyl group having 1 to 8 carbon atoms or an alkyltriyl group having 1 to 8 carbon atoms, more preferably a methyl group, a 2-ethylhexyl group or a propanetriyl group.

[R ¹²¹ And R ²¹² ]

R ¹²¹ And R ²¹² Each independently an alkylene group having 1 to 4 carbon atoms, preferably an ethylene group (- (CH) ₂ ) ₂ -) or propylene (-CH (CH) ₃ )CH ₂ -)。

Specific examples of the preferable compound (1-1) include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, 1-pentanol, 2-pentanol, isopentanol, 1-hexanol, 2-hexanol, 1-heptanol, 1-octanol, 2-ethyl-1-hexanol, 3, 5-trimethyl-1-hexanol, tridecanol, pentadecanol, palmitic alcohol, stearyl alcohol, eicosanol, cyclopentanol, cyclohexanol, methylcyclohexanol, trimethylcyclohexanol and the like.

Among them, isobutanol, 2-ethyl-1-hexanol, 3, 5-trimethyl-1-hexanol or tridecanol is preferred, and 3, 5-trimethyl-1-hexanol or tridecanol is more preferred.

Specific examples of the preferred compound (1-2) include: polyether polyols such as polypropylene glycol, pluronic-type polypropylene glycol obtained by adding ethylene oxide to the terminal of polypropylene glycol, polyoxypropylene-polyoxyethylene copolymer glycol, polyoxypropylene-polyoxyethylene block polymer glycol, polytetramethylene glycol, polyoxypropylene-polyoxybutylene copolymer glycol, and polyoxypropylene-polyoxybutylene block polymer glycol.

Among them, polypropylene glycol or Pluronic type polypropylene glycol is preferable for excellent solubility in a low-polarity organic solvent, and Pluronic type polypropylene glycol is more preferable for excellent reactivity.

In the present specification, the term "low-polarity organic solvent" refers to an organic solvent having an aniline point of-6 ℃ or higher, and includes non-polar organic solvents having no polarity. The low-polarity organic solvent is an organic solvent containing an aliphatic hydrocarbon solvent or an alicyclic hydrocarbon solvent as a main component, and may further contain an aromatic hydrocarbon solvent, an ester solvent, an ether solvent, or the like. Here, the "organic solvent containing an aliphatic hydrocarbon solvent or an alicyclic hydrocarbon solvent as a main component" means an organic solvent in which the content of the aliphatic hydrocarbon solvent or the alicyclic hydrocarbon solvent is 20 mass% or more, preferably 30 mass% or more, and more preferably 50 mass% or more, based on the total mass of the organic solvent.

The lower limit of the aniline point of the low-polarity organic solvent may be-6 ℃ and preferably-5 ℃. On the other hand, the upper limit of the aniline point of the low-polarity organic solvent may be 70 ℃, preferably 65 ℃, and more preferably 60 ℃.

That is, the aniline point of the low-polarity organic solvent may be-6 ℃ or higher and 70 ℃ or lower, preferably-5 ℃ or higher and 65 ℃ or lower, and more preferably-5 ℃ or higher and 60 ℃ or lower.

Specific examples of such a low-polarity organic solvent include methylcyclohexane (aniline point: 40 ℃), ethylcyclohexane (aniline point: 44 ℃), mineral spirits (mineral turpentine) (aniline point: 56 ℃), turpentine (aniline point: 20 ℃), and the like.

Further, a product commercially available as a petroleum hydrocarbon can be generally used. Examples of such commercially available products include HAWS (High Aromatic petroleum Solvent; manufactured by Shell Japan, aniline Point 17 ℃; esso-naphtha (Nippon: 1245612483124771241241241241241241241241241241241246 (manufactured by ExxonMobil Chemical Co., ltd., aniline Point 43 ℃).

In addition, a solvent in which at least 1 of these low-polarity organic solvents and, if necessary, an aromatic hydrocarbon-based solvent, an ester-based solvent, an ether-based solvent, and the like are mixed may be used.

Specific examples of the preferable compound (2-1) include: and polyether polyols such as polyoxypropylene-2-ethylhexyl ether, polyoxypropylene triol, pluronic type polyoxypropylene triol obtained by adding ethylene oxide to the end of polyoxypropylene triol, polyoxypropylene polyoxyethylene copolymer triol, polyoxypropylene polyoxyethylene block polymer triol, polyoxytetramethylene triol, polyoxydimethylpropylene polyoxybutylene copolymer triol, and polyoxydimethylpropylene polyoxybutylene block polymer triol.

Among them, polyoxypropylene triol and Pluronic polyoxypropylene triol are preferable for excellent solubility in low-polarity organic solvents, and Pluronic polyoxypropylene triol is more preferable for excellent reactivity.

<xnotran> , Excenol 840 (, , ( ), 6500), excenol 851 (, , ( ), 6700), excenol 510 (, , ( ), 4000), excenol 3020 (, , , 3000), excenol 2020 (, , , 2000), excenol 1020 (, , , 1000), LEOCON 1015H (, lion Corporation , 800, 2 ), preminol 7012 (, , ( ), 10000), preminol 3010 (, , , 12000), PTG1000 (, , , 1000) . </xnotran>

Among these, preferred modifiers having an active hydrogen-containing group are 1-butanol, 1-octanol, 2-ethyl-1-hexanol, 3, 5-trimethyl-1-hexanol, tridecanol, pentadecanol, palmityl alcohol, stearyl alcohol, eicosanol, excenol 840, excenol 851, excenol 510, excenol 2020, excenol 3020, excenol 1020, LEOCON 1015H or Preminol 7012, and more preferred are tridecanol, pentadecanol, palmityl alcohol, stearyl alcohol, eicosanol, excenol 851, excenol 1020, excenol 2020, excenol 3020, LEOCON 1015H or Preminol 7012.

[ number average molecular weight ]

The number average molecular weight of the modifier having an active hydrogen-containing group is preferably 30 or more and 20000 or less, more preferably 100 or more and 15000 or less, further preferably 150 or more and 10000 or less, particularly preferably 180 or more and 3000 or less. The modifier having an active hydrogen-containing group has a number average molecular weight of not more than the upper limit, so that hardness at the time of forming a coating film is more favorable, and on the other hand, has a number average molecular weight of not less than the lower limit, so that polarity is further lowered.

[ content of structural units derived from a modifier having an active hydrogen-containing group ]

In the modified polyisocyanate, the content of the structural unit derived from the modifying agent having an active hydrogen-containing group is preferably 0.1mol% or more and 30mol% or less, more preferably 0.5mol% or more and 25mol% or less, further preferably 1mol% or more and 20mol% or less, relative to the isocyanate group content of the polyisocyanate. The content of the structural unit derived from the modifier having an active hydrogen-containing group is not less than the lower limit, so that the polarity is lower, and on the other hand, the content is not more than the upper limit, so that the physical properties when a coating film is formed are better.

< polyisocyanate >

The polyisocyanate used for producing the modified polyisocyanate preferably satisfies the following (a) and (B).

(A) A diisocyanate derived from at least 1 diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, and a monohydric alcohol having 1 to 20 carbon atoms;

In the above (a), the aliphatic diisocyanate is a compound having 2 isocyanate groups in a molecule and a saturated aliphatic group, and the alicyclic diisocyanate is a compound having 2 isocyanate groups in a molecule and a cyclic saturated aliphatic group (also referred to as an alicyclic group). In order to be low in viscosity, a polyisocyanate derived from an aliphatic diisocyanate and a monohydric alcohol having 1 or more and 20 or less carbon atoms is preferable.

The aliphatic diisocyanate is preferably an aliphatic diisocyanate having 4 to 30 carbon atoms. Specific examples of the aliphatic diisocyanate include 1, 4-tetramethylene diisocyanate, 1, 5-pentamethylene diisocyanate, 1, 6-Hexamethylene Diisocyanate (HDI), 2, 4-trimethyl-1, 6-hexamethylene diisocyanate, lysine diisocyanate, and the like.

The alicyclic diisocyanate is preferably an alicyclic diisocyanate having 8 or more and 30 or less carbon atoms. Specific examples of the alicyclic diisocyanate include isophorone diisocyanate (hereinafter, referred to as "IPDI"), 1, 3-bis (isocyanatomethyl) -cyclohexane, 4' -dicyclohexylmethane diisocyanate, norbornene diisocyanate, and hydrogenated xylene diisocyanate.

These diisocyanates may be used singly or in combination of 2 or more.

Among them, HDI, IPDI, hydrogenated xylene diisocyanate or hydrogenated diphenylmethane diisocyanate are preferable for easy industrial availability, and HDI is particularly preferable from the viewpoint of excellent weatherability and flexibility in forming a coating film.

Hereinafter, the aliphatic diisocyanate and the alicyclic diisocyanate are collectively referred to as "diisocyanate monomers".

The monohydric alcohol has a carbon number of 1 to 20 inclusive in order to achieve both the dissolving power in the low-polarity organic solvent and the hardness of the coating film.

The lower limit of the carbon number of the monohydric alcohol is 1, preferably 2, more preferably 3, still more preferably 4, and particularly preferably 6. On the other hand, the upper limit is 20, preferably 16, more preferably 12, and still more preferably 9.

That is, the carbon number of the monohydric alcohol is 1 or more and 20 or less, preferably 2 or more and 16 or less, more preferably 3 or more and 12 or less, further preferably 4 or more and 9 or less, and particularly preferably 6 or more and 9 or less.

The monohydric alcohol has a carbon number of at least the lower limit value, and can exhibit a more sufficient dissolving power in a low-polarity organic solvent. On the other hand, the carbon number of the monohydric alcohol is not more than the above upper limit, and the hardness of the resulting coating film becomes more sufficient. The alcohol can be used alone in 1 kind, can also be mixed and used more than 2.

The monohydric alcohol having 1 to 20 carbon atoms may have at least 1 functional group selected from the group consisting of an ether group, an ester group, a carbonyl group and a phenyl group in the molecule, or may have only a saturated hydrocarbon group and a hydroxyl group.

Examples of the alcohol having an ether group in the molecule include 1-butoxyethanol, 2-butoxyethanol, 1-butoxypropanol, 2-butoxypropanol, 3-butoxypropanol, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, and the like.

Among these, the monohydric alcohol having 1 to 20 carbon atoms is preferably an alcohol composed only of a saturated hydrocarbon group and a hydroxyl group, more preferably an alcohol having a straight or branched saturated hydrocarbon group, and still more preferably an alcohol having a branched saturated hydrocarbon group. Specific examples of such alcohols include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, 1-pentanol, 2-pentanol, isopentanol, 1-hexanol, 2-hexanol, 1-heptanol, 1-octanol, 2-ethyl-1-hexanol, 3, 5-trimethyl-1-hexanol, tridecanol, pentadecanol, palmitol, stearyl alcohol, cyclopentanol, cyclohexanol, methylcyclohexanol, and trimethylcyclohexanol.

Among them, 1-propanol, 1-butanol, isobutanol, isoamyl alcohol, 1-hexanol, 2-hexanol, 1-heptanol, 1-octanol, 2-ethyl-1-hexanol, tridecanol, pentadecanol, palmityl alcohol, stearyl alcohol, or 1,3, 5-trimethylcyclohexanol is preferable in order to have particularly excellent solubility in a low-polarity organic solvent. Further, in order that the viscosity becomes lower, 1-propanol, 1-butanol, isobutanol, isoamyl alcohol, pentanol, 1-hexanol, 2-hexanol, 1-heptanol, 1-octanol, 2-ethyl-1-hexanol or 3, 5-trimethyl-1-hexanol is more preferable. In addition, in order to have very excellent solubility in a low-polarity organic solvent, isobutanol, 2-hexanol, 2-octanol, 2-ethyl-1-hexanol, or 3, 5-trimethyl-1-hexanol is further preferable.

In the above (B), the polyisocyanate contained in the polyisocyanate composition of the present embodiment may have at least an isocyanurate group and further an allophanate group. The polyisocyanate composition of the present embodiment may contain 1 molecule of a polyisocyanate having these functional groups, or may contain a mixture of polyisocyanates having different functional groups.

The "isocyanurate group" means a functional group obtained by reacting 3 isocyanate groups, and is a group represented by the following formula (3).

The "allophanate group" is a functional group obtained by reacting a hydroxyl group of an alcohol with an isocyanate group, and is a group represented by the following formula (4).

The molar ratio of allophanate groups to isocyanurate groups (allophanate groups/isocyanurate groups) is preferably 0/100 or more and 25/75 or less, more preferably 0/100 or more and 20/80 or less, and still more preferably 0/100 or more and 15/85 or less. When the molar ratio is within the above range, the hardness of the coating film formed is further improved.

The molar ratio allophanate group/isocyanurate group can be determined by ¹ H-NMR. The following shows based on ¹ One example of a method for measuring the molar ratio of allophanate groups to isocyanurate groups by H-NMR is described.

First, polyisocyanate was dissolved in deuterated chloroform at a concentration of 10 mass% (0.03 mass% of tetramethylsilane was added to the polyisocyanate). The chemical shift standards are as follows: the signal for hydrogen of tetramethylsilane was set to 0ppm. By using ¹ In the H-NMR measurement, the area ratio of the signal of hydrogen atoms bonded to nitrogen of an allophanate group (1 mol of hydrogen atoms to 1mol of allophanate groups) in the vicinity of 8.5ppm to the signal of hydrogen atoms of methylene groups adjacent to an isocyanurate group (6 mol of hydrogen atoms to 1mol of isocyanurate groups) in the vicinity of 3.85ppm was measured, and the molar ratio was determined by the following calculation formula.

Allophanate group/isocyanurate group = (area of signal in the vicinity of 8.5 ppm)/(area of signal in the vicinity of 3.85 ppm/6)

The polyisocyanate contained in the polyisocyanate composition of the present embodiment may have various functional groups such as biuret group, uretdione group, iminooxadiazinedione group, and urethane group, in addition to the isocyanurate group and the allophanate group. The polyisocyanate composition of the present embodiment may contain a polyisocyanate having these functional groups in 1 molecule, or may contain a mixture of polyisocyanates having different functional groups.

In general, the "biuret group" refers to a functional group obtained by reacting 3 isocyanate groups with a biuretizing agent, and is a group represented by the following formula (5).

The "uretdione group" is a functional group obtained by reacting 2 isocyanate groups, and is a group represented by the following formula (6).

In general, the "iminooxadiazinedione group" is a functional group obtained by reacting 3 isocyanate groups, and is a group represented by the following formula (7).

The "urethane group" is a functional group obtained by reacting 1 isocyanate group and 1 hydroxyl group, and is a group represented by the following formula (8).

The polyisocyanate contained in the polyisocyanate composition of the present embodiment preferably further has a structural unit derived from a nonionic hydrophilic compound.

The polyisocyanate having a structural unit derived from the nonionic hydrophilic compound, that is, having introduced a nonionic hydrophilic group, can be obtained by reacting the isocyanate group of the polyisocyanate with the hydroxyl group of the nonionic hydrophilic compound.

Examples of the nonionic hydrophilic compound include polyalkylene glycol monoalkyl ethers, polyethylene glycols, pluronic-type polyalkylene glycols, and the like. Among them, the nonionic hydrophilic compound is preferably a compound having 1 hydroxyl group, preferably a polyalkylene glycol monoalkyl ether, and more preferably polyethylene glycol monomethyl ether.

In the polyethylene glycol monomethyl ether, the number of repetition of oxyethylene groups is preferably 1 or more and 50 or less, more preferably 4 or more and 20 or less, and further preferably 4 or more and 10 or less. The number of repetitions is not less than the above lower limit, and thus a more sufficient emulsifying ability can be obtained in the blending with the water solvent or the aqueous base. On the other hand, the number of repetitions is not more than the above upper limit, and therefore, the crystallinity is more effectively suppressed from increasing, and the stability is maintained.

That is, the polyisocyanate contained in the polyisocyanate composition of the present embodiment preferably satisfies the following (C) in addition to the above (a) and (B).

(C) Having structural units derived from hydrophilic compounds.

Examples of the hydrophilic compound include a cationic hydrophilic compound, an anionic hydrophilic compound, and a nonionic hydrophilic compound.

Among these, the hydrophilic compound is preferably a nonionic hydrophilic compound, more preferably a nonionic hydrophilic compound containing a repeating unit of 1 or more hydroxyl groups and 1 or more and 50 or less oxyethylene groups, and particularly preferably polyethylene glycol monomethyl ether having a repeating number of oxyethylene groups of 1 or more and 50 or less.

[ Process for producing polyisocyanate ]

The polyisocyanate used for producing the modified polyisocyanate can be produced by a known method.

As a method for producing a polyisocyanate used for producing a modified polyisocyanate, a preferable typical synthesis method is described below.

The process (I) comprises subjecting a diisocyanate to an isocyanurateing reaction, and removing the unreacted diisocyanate by purification to obtain a polyisocyanate.

In the second method, after or simultaneously with the urethanation reaction of a monohydric alcohol having 1 to 20 carbon atoms with a diisocyanate, the allophanation reaction is carried out, and the unreacted diisocyanate is removed by purification to obtain a polyisocyanate.

The third method is a method in which a monohydric alcohol having 1 to 20 carbon atoms is subjected to a urethanization reaction, an isocyanuric acid esterification reaction, and an allophanatization reaction with a diisocyanate, and unreacted diisocyanate is removed by purification to obtain a polyisocyanate.

In the method (iii), the sequences of the urethanization reaction, the isocyanuric acid esterification reaction, and the allophanatization reaction may all be simultaneously carried out, or may be carried out separately, or after any reaction is carried out simultaneously, the remaining reactions may be carried out.

The methods (one) to (three) may be combined.

Any method may be used as long as the production is performed so that the molar ratio of allophanate groups/isocyanurate groups is in the range of 0/100 to 25/75.

The temperature of the urethanization reaction is preferably 20 ℃ to 200 ℃, more preferably 40 ℃ to 150 ℃, and still more preferably 60 ℃ to 120 ℃. The reaction temperature is not lower than the lower limit value, whereby the reaction proceeds more rapidly, while the reaction temperature is not higher than the upper limit value, whereby side reactions such as uretdione and the like are more effectively suppressed, and coloring of the reaction product is also more effectively suppressed.

The time of the carbamation reaction is preferably 10 minutes to 24 hours, more preferably 15 minutes to 15 hours, and still more preferably 20 minutes to 10 hours. The reaction time is not less than the lower limit value, whereby the reaction can be more reliably terminated, while the reaction time is not more than the upper limit value, whereby the production efficiency is more favorable and the side reaction is more effectively suppressed. The urethanization reaction may be carried out in the absence of a catalyst or in the presence of a tin-based or amine-based catalyst.

The reaction temperature of the isocyanuric acid esterification reaction is not particularly limited, but is preferably 50 ℃ or more and 200 ℃ or less, and more preferably 50 ℃ or more and 150 ℃ or less. The reaction temperature is not lower than the lower limit, so that the reaction tends to proceed more easily, while the reaction temperature is not higher than the upper limit, so that the occurrence of side reactions such as coloring tends to be further suppressed.

The allophanatization reaction is preferably 20 ℃ to 200 ℃, more preferably 40 ℃ to 180 ℃, still more preferably 60 ℃ to 160 ℃, particularly preferably 90 ℃ to 150 ℃, and most preferably 110 ℃ to 150 ℃. The reaction temperature is not lower than the lower limit, and the time required until the reaction is completed can be further shortened while the amount of the allophanatization catalyst used is further reduced. On the other hand, when the reaction temperature is not more than the above upper limit, the side reaction such as uretdione is more effectively suppressed, and the coloring of the reaction product is also more effectively suppressed.

The reaction temperature at which the isocyanuric acid esterification reaction and the allophanatization reaction are carried out simultaneously is not particularly limited, but is preferably 50 ℃ or higher and 200 ℃ or lower, more preferably 50 ℃ or higher and 150 ℃ or lower. The reaction temperature is not lower than the lower limit value, so that the reaction tends to proceed more easily, while the reaction temperature is not higher than the upper limit value, so that the occurrence of a side reaction such as coloring can be further suppressed, or the production can be performed more stably without causing a runaway reaction.

When the isocyanuric acid esterification reaction and the allophanation reaction are carried out by the methods (one) to (three), an isocyanurate/allophanation catalyst is preferably used. Isocyanurate/allophanatization catalysts, for example, are generally preferred to have basic properties. Specific examples of the isocyanurate/allophanation catalyst include those shown in the following 1) to 7).

1) Hydroxides and weak organic acid salts of organic quaternary ammonium;

2) Hydroxides and weak organic acid salts of hydroxyalkylammonium;

3) Metal salts of alkyl carboxylic acids;

4) Alkoxides of alkali metals;

5) An aminosilyl-containing compound;

6) Mannich bases;

7) Use of tertiary amines in combination with epoxy compounds

Examples of the organic quaternary ammonium include tetramethylammonium, tetraethylammonium, tetrabutylammonium, trimethylbenzylammonium, and the like.

Examples of the weak organic acid constituting the weak organic acid salt include acetic acid and capric acid.

Examples of the hydroxyalkylammonium include trimethylhydroxypropylammonium, trimethylhydroxyethylammonium, triethylhydroxypropylammonium, and triethylhydroxyethylammonium.

Examples of the alkyl carboxylic acid include acetic acid, caproic acid, caprylic acid, and myristic acid.

Examples of the metal constituting the metal salt include tin, zinc, lead, sodium, potassium, zirconium, zirconyl, and the like.

Examples of the alkali metal include sodium and potassium.

Examples of the compound containing an aminosilyl group include hexamethyldisilazane and the like.

Among them, as the isocyanurate/allophanatization catalyst, the above 1), 2) or 3) is preferable. The aminosilyl group-containing compound causes a side reaction such as uretdionization depending on the conditions under which it is used. In addition, tetraalkylammonium salts of weak organic acids are more preferable, and tetramethylammonium decanoate is still more preferable.

The amount of the isocyanurate/allophanation catalyst added is preferably 0.001% by mass or more and 2.0% by mass or less, more preferably 0.01% by mass or more and 0.5% by mass or less, based on the total mass of the reaction liquid. The amount of addition is not less than the lower limit, whereby the effect of the catalyst can be more sufficiently exhibited. On the other hand, the amount of addition is not more than the above upper limit, so that the reaction can be controlled more easily.

The method of adding the isocyanurate/allophanatization catalyst is not limited. For example, the compound containing a urethane group may be added before the production of the compound containing a urethane group, that is, before the urethanization reaction between the diisocyanate and the monohydric alcohol having 1 to 20 carbon atoms, may be added during the urethanization reaction between the diisocyanate and the monohydric alcohol having 1 to 20 carbon atoms, or may be added after the production of the compound containing a urethane group. In addition, as the method of adding, can add the required amount of isocyanurate/allophanation catalyst once, also can add in several times. Alternatively, a method of continuously adding the solution at a constant addition rate may be employed.

The urethanization reaction, isocyanuric acid esterification reaction and allophanatization reaction are carried out under the condition of no solvent, and can also be carried out in a solvent according to requirements. Examples of the solvent include the low-polarity organic solvent, ester-based solvent, ketone-based solvent, aromatic-based solvent, organic solvent having no reactivity with an isocyanate group, and a mixture thereof. Examples of the ester-based solvent include ethyl acetate and butyl acetate. Examples of the ketone solvent include methyl ethyl ketone. Examples of the aromatic solvent include toluene, xylene, and diethylbenzene. Examples of the organic solvent having no reactivity with the isocyanate group include dialkyl polyalkylene glycol ethers and the like.

The progress of the urethanation reaction, the isocyanurate reaction and the allophanation reaction can be followed by measuring the NCO content of the reaction liquid or measuring the refractive index.

The yield of the polyisocyanate tends to be usually 10 mass% or more and 70 mass% or less. The polyisocyanate obtained in a higher yield tends to have a higher viscosity. The yield can be calculated from the ratio of the mass of the obtained polyisocyanate to the total mass of the raw material components.

The isocyanurated reaction and the allophanatized reaction were stopped by cooling to room temperature, or by adding a reaction terminator. In particular, when a catalyst is used, it is preferable to add a reaction terminator in order to suppress side reactions. The amount of the reaction terminator to be added is preferably 0.25 to 20 times the molar amount of the catalyst, more preferably 0.5 to 16 times the molar amount of the catalyst, and still more preferably 1.0 to 12 times the molar amount of the catalyst. The amount of the reaction terminator to be added is not less than the lower limit value, whereby the catalyst can be more completely deactivated. On the other hand, the addition amount is not more than the above upper limit, so that the storage stability becomes more excellent. Any reaction terminator may be used as long as it deactivates the catalyst. Specific examples of the reaction terminator include a compound exhibiting phosphoric acid acidity, a monoalkyl ester or dialkyl ester of a compound exhibiting phosphoric acid acidity, a halogenated acetic acid, benzoyl chloride, a sulfonate, sulfuric acid, a sulfate, an ion exchange resin, and a chelating agent. Examples of the compound exhibiting phosphoric acid acidity include phosphoric acid, pyrophosphoric acid, metaphosphoric acid, polyphosphoric acid, and the like. Examples of the halogenated acetic acid include monochloroacetic acid and the like.

Among them, phosphoric acid, pyrophosphoric acid, metaphosphoric acid, polyphosphoric acid, monoalkyl phosphate esters or dialkyl phosphate esters are preferable as the reaction terminator from the industrial viewpoint that stainless steel is not easily corroded. Specific examples of the phosphoric acid monoester and phosphoric acid diester include phosphoric acid monoethyl ester, phosphoric acid diethyl ester, phosphoric acid monobutyl ester, phosphoric acid dibutyl ester, phosphoric acid mono (2-ethylhexyl) ester, phosphoric acid di (2-ethylhexyl) ester, phosphoric acid monodecanyl ester, phosphoric acid didecyl ester, phosphoric acid monolauryl ester, phosphoric acid dilauryl ester, phosphoric acid monotridecyl ester, phosphoric acid ditridecyl ester, phosphoric acid monooleyl ester, phosphoric acid dioleyl ester, and a mixture thereof.

Further, an adsorbent such as silica gel or activated carbon may be used as the terminator. The amount of the adsorbent to be added is preferably 0.05% by mass or more and 10% by mass or less based on the mass of the diisocyanate used in the reaction.

After the reaction is completed, the unreacted diisocyanate and the solvent may be separated from the polyisocyanate. From the viewpoint of safety, it is preferable to separate the unreacted diisocyanate. The concentration of the residual unreacted diisocyanate monomer in the polyisocyanate is preferably 3.0% by mass or less, more preferably 1.0% by mass or less, and still more preferably 0.5% by mass or less, based on the total mass of the polyisocyanate. The concentration of the residual unreacted diisocyanate monomer is not more than the above upper limit, and the curing property tends to be more excellent. Examples of the method for separating the unreacted diisocyanate and the solvent include a thin film distillation method and a solvent extraction method.

[ physical Properties of polyisocyanate ]

Next, the physical properties of the polyisocyanate will be described in detail below.

(viscosity at 25 ℃ C.)

The viscosity of the polyisocyanate at 25 ℃ is not particularly limited, but is preferably 50 to 10000 mPas, more preferably 70 to 7000 mPas, and still more preferably 100 to 8000 mPas. When the viscosity of the polyisocyanate at 25 ℃ is not lower than the lower limit value, the curing property tends to be more excellent. On the other hand, when the viscosity of the polyisocyanate at 25 ℃ is not more than the above upper limit, the workability tends to be further excellent.

The viscosity can be measured by using an E-type viscometer (manufactured by Tokimec).

(isocyanate group content)

The lower limit of the isocyanate group content (hereinafter, may be referred to as "NCO content") of the polyisocyanate may be 3 mass%, preferably 4 mass%, more preferably 5 mass% in a state where the solvent or diisocyanate is not substantially contained.

On the other hand, the upper limit of the NCO content may be 30% by mass, preferably 27% by mass, more preferably 25% by mass, in a state substantially free from solvent and diisocyanate.

The NCO content is in the above range, so that the polyisocyanate compound can be more sufficiently dissolved in the low-polarity organic solvent or the base compound, and a polyisocyanate composition having more sufficient crosslinkability can be obtained.

In the present specification, the phrase "a state of substantially not containing a solvent or diisocyanate" refers to a state in which the content of the solvent or diisocyanate is less than 1% by mass based on the total mass of the isocyanate components.

< end-capping agent >

In the polyisocyanate composition of the present embodiment, a part or all of the isocyanate groups of the reaction product (modified polyisocyanate) may be blocked by a blocking agent. That is, the polyisocyanate composition of the present embodiment may be a blocked polyisocyanate composition in which a part or all of the modified polyisocyanate is a blocked polyisocyanate. The blocked polyisocyanate composition can be used in one-pack type coatings.

The blocking agent is a compound having 1 active hydrogen-containing group in the molecule, and specific examples thereof include alcohol-based compounds, alkylphenol-based compounds, phenol-based compounds, active methylene-based compounds, thiol-based compounds, acid amide-based compounds, acid imide-based compounds, imidazole-based compounds, urea-based compounds, oxime-based compounds, amine-based compounds, imide-based compounds, pyrazole-based compounds, and the like.

More specifically, the blocking agent includes those shown in the following (i) to (xiii). These blocking agents may be used alone in 1 kind, or in combination of 2 or more kinds.

(i) Alcohol-based compound: methanol, ethanol, 2-propanol, 1-butanol, sec-butanol, 2-ethyl-1-hexanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol.

(ii) Alkylphenol-based compound: monoalkylphenols or dialkylphenols having an alkyl group having 4 or more carbon atoms as a substituent.

Examples of the monoalkylphenols include n-propylphenol, isopropylphenol, n-butylphenol, sec-butylphenol, tert-butylphenol, n-hexylphenol, 2-ethylhexyl phenol, n-octylphenol, and n-nonylphenol.

Examples of the dialkylphenols include di-n-propylphenol, diisopropylphenol, isopropylcresol, di-n-butylphenol, di-tert-butylphenol, di-sec-butylphenol, di-n-octylphenol, di-2-ethylhexyl phenol, di-n-nonylphenol, and the like.

(iii) A phenolic compound: phenol, cresol, ethylphenol, styrenated phenol, hydroxybenzoates.

(iv) Active methylene-based compound: dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate and acetylacetone.

(v) Thiol-based compound: butyl mercaptan, dodecyl mercaptan.

(vi) Acid amide compound: acetanilide, acetic acid amide, epsilon-caprolactam, delta-valerolactam and gamma-butyrolactam.

(vii) Acid imide compound: succinimide of succinic acid, and imide of maleic acid.

(viii) An imidazole-based compound: imidazole, 2-methylimidazole.

(ix) A urea-based compound: urea, thiourea, ethylene urea.

(x) Oxime compound: formaldehyde oxime, acetaldehyde oxime, acetyl oxime, methyl ethyl ketoxime, cyclohexanone oxime.

(xi) Amine-based compound: diphenylamine, aniline, carbazole, di-n-propylamine, diisopropylamine and isopropylethylamine.

(xii) Imine-based compound: ethyleneimine, polyethyleneimine.

(xiii) Pyrazole compounds: pyrazole, 3-methylpyrazole, 3, 5-dimethylpyrazole.

Among them, the blocking agent is preferably an imidazole-based compound, an active methylene-based compound, an oxime-based compound, an amine-based compound or a pyrazole-based compound, more preferably an oxime-based compound, an amine-based compound or a pyrazole-based compound, and further preferably methylethylketoxime or 3, 5-dimethylpyrazole. By using these end-capping agents, compatibility between low-temperature curability and various main agents can be achieved at the same time.

[ content of structural units derived from a capping agent ]

In the blocked polyisocyanate, the content of the structural unit derived from the blocking agent (the residue of the blocking agent other than the active hydrogen-containing group) is preferably 1.0 times or more and 1.2 times or less, more preferably 1.0 times or more and 1.1 times or less, relative to the isocyanate group content of the polyisocyanate. The content of the structural unit derived from the end-capping agent is in the above range, so that the storage stability when forming a one-pack type coating material is more excellent and the physical properties when forming a coating film become more excellent.

< method for producing polyisocyanate composition >

The reaction product of the polyisocyanate contained in the polyisocyanate composition of the present embodiment and the modifier having an active hydrogen-containing group can be obtained, for example, as follows: the polyisocyanate is reacted with the modifier having an active hydrogen-containing group at a temperature of about 100 ℃ to 150 ℃ for a period of about 1 hour to 5 hours.

The amount of the modifier having an active hydrogen-containing group blended is preferably 0.1mol% or more and 30mol% or less, more preferably 0.5mol% or more and 25mol% or less, and further preferably 1mol% or more and 20mol% or less, based on the isocyanate group content of the polyisocyanate. The amount of the modifier having an active hydrogen-containing group blended is not less than the lower limit, whereby the polarity becomes lower, while the amount blended is not more than the upper limit, whereby the physical properties at the time of forming a coating film become better.

The obtained polyisocyanate composition is reacted with a hydrophilic compound at a temperature of about 80 ℃ to 150 ℃ for a time of about 1 hour to 8 hours, whereby a hydrophilic polyisocyanate composition containing a polyisocyanate having a hydrophilic group introduced thereto (i.e., a hydrophilic polyisocyanate) can be obtained.

In addition, by reacting the obtained polyisocyanate composition with a blocking agent at a temperature of 10 ℃ or higher and 90 ℃ or lower for a period of time of about 1 hour or longer and 5 hours or shorter, a blocked polyisocyanate composition containing a polyisocyanate having a structural unit derived from the blocking agent (i.e., a blocked polyisocyanate) can be obtained.

The amount of the blocking agent to be blended is preferably 1.0 time or more and 1.2 times or less, more preferably 1.0 time or more and 1.1 times or less, based on the isocyanate group content of the polyisocyanate. When the amount of the end-capping agent is within the above range, the storage stability of the one-pack type coating material is further improved and the physical properties of the coating film are further improved.

Coating composition

The polyisocyanate composition of the above embodiment can be suitably used as a curing agent for a coating composition, and the like.

That is, the coating composition of the present embodiment contains the polyisocyanate composition of the above embodiment.

< resin component >

The coating composition of the present embodiment further contains a resin component as a main agent. The resin component is not particularly limited, and preferably contains a compound having 2 or more active hydrogen-containing groups having reactivity with an isocyanate group in the molecule.

The compound having 2 or more active hydrogen-containing groups in the molecule is not limited to the following, and examples thereof include polyols, polyamines, polythiols, and the like. Among these, as the compound having 2 or more active hydrogen-containing groups in the molecule, a polyhydric alcohol is preferable. The polyol is not limited to the following, and examples thereof include polyester polyol, polyether polyol, acrylic polyol, polyolefin polyol, and fluoro polyol.

Among them, as the polyol, acrylic polyols are preferable from the viewpoint of weather resistance, chemical resistance and hardness, polyester polyols are preferable from the viewpoint of mechanical strength and oil resistance, and fluoro polyols are preferable from the viewpoint of super weather resistance.

[ polyester polyol ]

The polyester polyol can be obtained, for example, by condensation reaction of 1 dibasic acid alone or a mixture of 2 or more dibasic acids with 1 polyol alone or a mixture of 2 or more polyols.

Examples of the dibasic acid include carboxylic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1, 4-cyclohexanedicarboxylic acid.

Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, diethylene glycol, 1, 4-butane diol, neopentyl glycol, 1, 6-hexane diol, trimethylpentane diol, cyclohexane diol, trimethylolpropane, glycerol, pentaerythritol, 2-hydroxymethylpropane diol, and ethoxylated trimethylolpropane.

As a specific method for producing the polyester polyol, for example, the condensation reaction can be carried out by mixing the above components and heating the mixture at about 160 ℃ to 220 ℃.

Alternatively, for example, polycaprolactone obtained by ring-opening polymerization of a lactone such as e-caprolactone using a polyol can be used as the polyester polyol.

The polyester polyol obtained by the above-mentioned production method can be modified with an aromatic diisocyanate, an aliphatic diisocyanate, an alicyclic diisocyanate, a compound obtained therefrom, or the like. Among them, the polyester polyol is preferably modified with aliphatic diisocyanate, alicyclic diisocyanate, and compounds obtained therefrom from the viewpoints of weather resistance and yellowing resistance of the obtained coating film.

When the coating composition of the present embodiment contains a solvent having a large amount of water, the polyester polyol can be made into a water-soluble or water-dispersible resin by leaving a part of carboxylic acid derived from a dibasic acid or the like in the polyester polyol and neutralizing the carboxylic acid with a base such as amine or ammonia.

[ polyether polyol ]

The polyether polyol can be obtained by any of the following methods (1) to (3), for example.

Process (1) by random addition or block addition of the individual alkylene oxides or mixtures of alkylene oxides onto the individual polyhydroxyl compounds or mixtures of polyhydroxyl compounds using catalysts to give polyether polyols.

Examples of the catalyst include hydroxides (lithium, sodium, potassium, and the like), strongly basic catalysts (alkoxides, alkylamines, and the like), complex metal cyanide compound complexes (metalloporphyrins, zinc hexacyanocobaltate complexes, and the like), and the like.

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

Examples of the polyhydric hydroxyl compound include those shown in the following (i) to (vi).

(i) Diglycerin, ditrimethylolpropane, and the like.

(ii) Sugar alcohol compounds such as pentaerythritol, dipentaerythritol, erythritol, D-threitol, L-arabitol, ribitol, xylitol, sorbitol, mannitol, galactitol, and rhamnose alcohol.

(iii) Monosaccharides such as arabinose, ribose, xylose, glucose, mannose, galactose, fructose, sorbose, rhamnose, fucose and deoxyribose.

(iv) Disaccharides trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose, melibiose, and the like.

(v) Raffinose, gentianose, melezitose and other trisaccharides.

(vi) Tetrasaccharides such as stachyose.

Process (2) for reacting a polyamine compound with an alkylene oxide to obtain a polyether polyol.

Examples of the polyamine compound include ethylenediamine compounds.

The alkylene oxide may be the same as exemplified in (1).

The method (3) is a method of polymerizing acrylamide or the like using the polyether polyol obtained in the step (1) or (2) as a medium to obtain a so-called polymer polyol.

[ acrylic polyol ]

The acrylic polyol can be obtained, for example, as follows: the polymerizable monomer composition can be obtained by polymerizing only a polymerizable monomer having 1 or more active hydrogen-containing groups in one molecule, or by copolymerizing a polymerizable monomer having 1 or more active hydrogen-containing groups in one molecule and, if necessary, another monomer copolymerizable with the polymerizable monomer.

Examples of the polymerizable monomer having 1 or more active hydrogen-containing groups in one molecule include those shown in the following (i) to (vi). These can be used alone, can also be combined with more than 2 and use.

(i) Acrylic esters having an active hydrogen-containing group such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxybutyl acrylate.

(ii) Methacrylic acid esters having an active hydrogen-containing group such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 3-hydroxypropyl methacrylate and 4-hydroxybutyl methacrylate.

(iii) (meth) acrylic acid esters having a polyvalent active hydrogen-containing group such as (meth) acrylic acid monoesters of triols such as glycerin and trimethylolpropane.

(iv) Polyether polyols (e.g., polyethylene glycol, polypropylene glycol, polybutylene glycol, etc.) and monoethers of the above (meth) acrylates having an active hydrogen-containing group.

(v) Adducts of glycidyl (meth) acrylate with monobasic acids such as acetic acid, propionic acid, p-tert-butylbenzoic acid, and the like.

(vi) An adduct obtained by ring-opening polymerizing a lactone (e.g.,. Epsilon. -caprolactam,. Gamma. -valerolactone, etc.) to the active hydrogen-containing group of the above-mentioned (meth) acrylate having an active hydrogen-containing group.

Examples of the other monomer copolymerizable with the polymerizable monomer include those shown in the following (i) to (v). These may be used alone, or 2 or more kinds may be used in combination.

(i) (meth) acrylates such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate and glycidyl methacrylate.

(ii) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid.

(iii) Unsaturated amides such as acrylamide, N-methylolacrylamide and diacetone acrylamide.

(iv) Vinyl monomers having a hydrolyzable silyl group such as vinyltrimethoxysilane, vinylmethyldimethoxysilane and γ - (meth) acryloylpropyltrimethoxysilane.

(v) Other polymerizable monomers such as styrene, vinyl toluene, vinyl acetate, acrylonitrile, and dibutyl fumarate.

As a specific method for producing an acrylic polyol, for example, the above-mentioned monomers are solution-polymerized in the presence of a known radical polymerization initiator such as a peroxide or an azo compound, and diluted with an organic solvent or the like as necessary to obtain an acrylic polyol.

When the coating composition of the present embodiment contains a solvent having a large water content, it can be produced by a known method such as solution polymerization and conversion into an aqueous layer of the monomer or emulsion polymerization. In the above case, water solubility or water dispersibility can be imparted to the acrylic polyol by neutralizing an acidic moiety of a carboxylic acid-containing monomer such as acrylic acid or methacrylic acid, a sulfonic acid-containing monomer, or the like with an amine or ammonia.

[ polyolefin polyol ]

Examples of the polyolefin polyol include: polybutadiene having 2 or more hydroxyl groups, hydrogenated polybutadiene having 2 or more hydroxyl groups, polyisoprene having 2 or more hydroxyl groups, hydrogenated polyisoprene having 2 or more hydroxyl groups, and the like.

The number of hydroxyl groups of statistically 1 molecule of the polyolefin polyol (hereinafter, sometimes referred to as "average number of hydroxyl groups") is preferably 2 or more.

[ Fluoropolyol ]

In the present specification, "fluorinated polyol" means a polyol containing fluorine in the molecule. Specific examples of the fluoropolyol include copolymers of a fluoroolefin, a cyclic vinyl ether, a hydroxyalkyl vinyl ether, and a vinyl monocarboxylic acid disclosed in patent documents 4 and 5.

[ hydroxyl value and acid value of polyol ]

The lower limit of the hydroxyl value of the polyol is preferably 10mgKOH/g, more preferably 20mgKOH/g, and still more preferably 30mgKOH/g.

The upper limit of the hydroxyl value of the polyol is preferably 200mgKOH/g, more preferably 180mgKOH/g, and still more preferably 160mgKOH/g.

That is, the hydroxyl value of the polyol is preferably 10mgKOH/g or more and 200mgKOH/g or less, more preferably 20mgKOH/g or more and 180mgKOH/g or less, and still more preferably 30mgKOH/g or more and 160mgKOH/g or less.

The hydroxyl value of the polyol is in the above range, whereby the workability of the coating composition of the present embodiment, and the weather resistance, chemical resistance and hardness of a coating film using the coating composition become further excellent.

That is, the coating composition of the present embodiment preferably includes the polyisocyanate composition of the above embodiment and a polyol having a hydroxyl value of 10mgKOH/g or more and 200mgKOH/g or less.

The acid value of the polyol is preferably from 0mgKOH/g to 30mgKOH/g.

The hydroxyl value and acid value can be measured in accordance with JIS K1557.

[NCO/OH]

The molar ratio (NCO/OH) of the isocyanate group in the polyisocyanate composition of the above embodiment to the hydroxyl group in the compound having 2 or more active hydrogen-containing groups in the molecule is preferably 0.2 or more and 5.0 or less, more preferably 0.4 or more and 3.0 or less, and still more preferably 0.5 or more and 2.0 or less.

When the NCO/OH ratio is not less than the above lower limit, a stronger coating film tends to be obtained. On the other hand, if the NCO/OH ratio is not higher than the above upper limit, the smoothness of the coating film tends to be further improved.

< other additives >

The coating composition of the present embodiment may further contain a melamine-based curing agent such as a fully alkyl type, a hydroxymethyl type alkyl group, or an imino type alkyl group, as necessary, in addition to the polyisocyanate composition and the resin component.

The resin component, the polyisocyanate composition of the embodiment, and the coating composition of the embodiment may contain an organic solvent.

The organic solvent is not particularly limited, preferably does not have a functional group reactive with a hydroxyl group and an isocyanate group, and is preferably sufficiently compatible with the polyisocyanate composition. The organic solvent is not limited to the following, and examples thereof include compounds generally used as coating solvents, such as ester compounds, ether compounds, ketone compounds, aromatic compounds, ethylene glycol dialkyl ether compounds, polyethylene glycol dicarboxylate compounds, hydrocarbon solvents, and aromatic solvents.

The resin component, the polyisocyanate composition of the embodiment, and the coating composition of the embodiment may be used by mixing various additives used in the art, such as a catalyst for accelerating curing, a pigment, a leveling agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a plasticizer, and a surfactant, according to the purpose and use thereof, within a range not to impair the desired effects of the embodiment.

Examples of the curing accelerating catalyst include, but are not limited to, metal salts and tertiary amines.

Examples of the metal salt include dibutyltin dilaurate, tin 2-ethylhexanoate, zinc 2-ethylhexanoate, and cobalt salts.

Examples of the tertiary amine include triethylamine, pyridine, picoline, benzyldimethylamine, N-dimethylcyclohexylamine, N-methylpiperidine, pentamethyldiethylenetriamine, N '-endo-ethylene piperazine, and N, N' -dimethylpiperazine.

Examples of the pigment include titanium oxide, carbon black, indigo, quinacridone, and pearl mica.

The leveling agent is not particularly limited, and examples thereof include silicone, AEROSIL, wax, stearate, and polysiloxane.

Examples of the antioxidant, ultraviolet absorber, and light stabilizer include aliphatic, aromatic, or alkyl-substituted aromatic esters of phosphoric acid or phosphorous acid, hypophosphorous acid derivatives, phosphorus compounds, phenol derivatives (particularly hindered phenol compounds), compounds containing sulfur, tin compounds, and the like. These may be contained alone or in combination of 2 or more.

Examples of the phosphorus compound include phenylphosphonic acid, phenylphosphinic acid, diphenylphosphonic acid, polyphosphonate, dialkylpentaerythritol diphosphite, and dialkylbisphenol A diphosphite.

Examples of the compound containing sulfur include thioether compounds, dithiocarboxylate compounds, mercaptobenzimidazole compounds, thiocarbanilide compounds, thiodipropionate esters, and the like.

Examples of the tin-based compound include tin maleate, dibutyltin monooxide, and the like.

The plasticizer is not particularly limited, and examples thereof include phthalic acid esters, phosphoric acid esters, fatty acid esters, pyromellitic acid esters, epoxy plasticizers, polyether plasticizers, liquid rubbers, and non-aromatic paraffin waxes.

Examples of the phthalate ester include dioctyl phthalate, dibutyl phthalate, diethyl phthalate, butyl benzyl phthalate, di-2-ethylhexyl phthalate, diisodecyl phthalate, diundecyl phthalate, and diisononyl phthalate.

Examples of the phosphate esters include tricresyl phosphate, triethyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, trimethylhexyl phosphate, trichloroethyl phosphate, and tris-dichloropropyl phosphate.

Examples of the fatty acid esters include octyl trimellitate, isodecyl trimellitate, trimellitates, dipentaerythritol esters, dioctyl adipate, dimethyl adipate, di-2-ethylhexyl azelate, dioctyl sebacate, di-2-ethylhexyl sebacate, and methyl acetylricinoleate.

Examples of the pyromellitic acid ester include octyl pyromellitate and the like.

Examples of the epoxy plasticizer include epoxidized soybean oil, epoxidized linseed oil, and epoxidized fatty acid alkyl esters.

Examples of the polyether plasticizer include adipic acid ether ester and polyether.

Examples of the liquid rubber include liquid NBR, liquid acrylic rubber, and liquid polybutadiene.

Examples of the surfactant include known anionic surfactants, cationic surfactants, and amphoteric surfactants.

< method for producing coating composition >

The coating composition of the present embodiment can be produced, for example, by the following method.

First, a resin containing a compound having 2 or more active hydrogen-containing groups in the molecule or a solvent dilution thereof is added with additives such as other resins, a curing accelerating catalyst, a pigment, a leveling agent, an antioxidant, an ultraviolet absorber, a light stabilizer, a plasticizer, and a surfactant as necessary, and the polyisocyanate composition or the blocked polyisocyanate composition is added thereto as a curing agent. Subsequently, a solvent is further added as necessary to adjust the viscosity. Subsequently, the coating composition can be obtained by stirring with a hand or a stirrer such as a Mazelar stirrer.

< usage >)

The coating composition of the present embodiment can be used as a coating material for roll coating, curtain coating, spray coating, spin-cup coating, electrostatic coating, and the like. Further, the primer composition can be used as a primer or a top-coat primer for a material such as a metal (e.g., a steel sheet or a surface-treated steel sheet), a plastic, a wood, a film, or an inorganic material. In addition, the coating composition is also useful as a coating material for imparting heat resistance, aesthetic properties (surface smoothness, clearness), and the like to precoated metals including rust-proof steel sheets, automobile coatings, and the like. In addition, urethane materials such as adhesives, pressure-sensitive adhesives, elastomers, foams, and surface-treating agents are also useful.

(film coating)

The coating film of the present embodiment is obtained by curing the coating composition of the above embodiment, and is excellent in gloss, distinctness of image, hardness, and weather resistance.

The coating film of the present embodiment can be produced as follows: the coating composition can be produced by applying the above coating composition to an object to be coated by a known coating method such as roll coating, curtain coating, spray coating, spin-cup coating, or electrostatic coating, and then curing the coating composition.

The substrate may be the same as the raw material exemplified in the above "< use >".

Examples

The present embodiment will be described more specifically below with reference to specific examples and comparative examples, but the present embodiment is not limited to the following examples and comparative examples as long as the gist of the present embodiment is not exceeded.

< method for measuring physical Properties >

The physical properties of the polyisocyanate compositions in the examples and comparative examples were measured as follows. Unless otherwise specified, "parts" and "%" mean "parts by mass" and "% by mass".

[ Property 1] viscosity

The viscosity of each polyisocyanate was measured at 25 ℃ with an E-type viscometer (manufactured by Tokimec). For the measurement, a standard rotor (1 ℃ 34' × R24) was used. The rotational speed is as follows.

(rotational speed)

100rpm (lower than 128 mPas)

50rpm (128 mPas or more and less than 256 mPas)

20rpm (256 mPas or more and less than 640 mPas)

10rpm (640 mPas or more and less than 1280 mPas)

5rpm (1280 mPas or more and 2560 mPas or less)

[ Property 2] content of isocyanate group (NCO)

The isocyanate group (NCO) content (% by mass) was determined as follows: the isocyanate group in each polyisocyanate was neutralized with an excess of 2N amine, and back-titrated with 1N hydrochloric acid to obtain the isocyanate group.

[ Property 3] measurement of AA-SP value

The AA-SP value of each polyisocyanate composition was determined as follows.

0.2g of each sample was dissolved in 10mL of a good solvent (acetic acid). While the solution was stirred with a magnetic stirrer, a poor solvent (water and hexane) was added dropwise to determine the cloud point. Cloud points were as follows: the amount of the poor solvent dropped when the characters written on the paper placed on the opposite side of the transparent container were not read from the front side of the container through the sample placed in the container. Based on the respective cloud points, the AA-SP values were determined as follows.

When the SP value of a good solvent (acetic acid) is δ g (= 12.4), the SP value of a poor solvent (water) having a high SP value is δ ph (= 23.4), the SP value of a poor solvent (hexane) having a low SP value is δ pl (= 7.28), and the volume fractions of the poor solvent at the cloud point at the time of dropping the poor solvent at the high SP value side and the low SP value side are Φ ph and Φ pl, respectively, the SP values δ mh and δ ml of the mixed solvent at the cloud point are obtained from the following expressions (I) and (II), and the target AA-SP value δ poly is further obtained from the following expression (III).

δ _mh ＝Φ _ph δ _ph +(1-Φ _ph )δ _g (I)

δ _ml ＝Φ _pl δ _pl +(1-Φ _pl )δ _g (II)

< evaluation method >

[ evaluation 1] gloss of coating film

Each of the coating compositions obtained in examples and comparative examples was applied to a glass plate so that the dry film thickness became 40 μm, and then cured at 23 ℃ and 50% RH for 1 week to obtain a coating film. The coating composition containing the polyisocyanate composition using the blocking agent was cured at 140 ℃ for 30 minutes to obtain a coating film. The gloss of the formed coating film was measured at 20 ℃ by a gloss meter UGV-6P (manufactured by Suga Test Instruments Co., ltd.). The evaluation criteria are as follows.

(evaluation criteria)

Excellent: the luster is more than 70 percent

Good component: the luster is more than 60 percent and less than 70 percent

And (delta): the luster is more than 50 percent and less than 60 percent

X: the luster is less than 50 percent

[ evaluation 2] distinctness of image (DOI) of coating film

Each of the coating compositions obtained in examples and comparative examples was applied to a glass plate so that the dry film thickness became 40 μm, and then cured at 23 ℃ and 50% RH for 1 week to obtain a coating film. The coating composition containing the polyisocyanate composition using the blocking agent was cured at 140 ℃ for 30 minutes to obtain a coating film. The resulting coating film was measured by Wave-scan dual (BYK) to obtain an image clarity value. The evaluation criteria are as follows.

(evaluation criteria)

Very good: the image definition value is more than 80 percent

Good: the image definition value is more than 70% and less than 80%

And (delta): the image definition value is more than 60% and less than 70%

X: the image definition value is less than 60%

[ evaluation 3] hardness of coating film

Each of the coating compositions obtained in examples and comparative examples was applied to a whiteboard so that the dry film thickness became 40 μm, and then cured at 23 ℃ and 50% RH for 1 week to obtain a coating film. The coating composition containing the polyisocyanate composition using the blocking agent was cured at 140 ℃ for 30 minutes to obtain a coating film. The hardness of the coating film was measured with a hardness tester (BYK Chemie Co., ltd.). The evaluation criteria were as follows.

(evaluation criteria)

Very good: the number of measurements is 80 or more

Good: the number of measurements is 60 or more and less than 80

And (delta): the number of measurements is 50 or more and less than 60

X: the number of measurements is less than 50

[ evaluation 4] weather resistance of coating film

Each of the coating compositions obtained in examples and comparative examples was applied onto a whiteboard so that the dry film thickness became 40 μm, and then cured at 23 ℃ and 50% RH for 1 week to obtain a coating film. The coating composition containing the polyisocyanate composition using the blocking agent was cured at 140 ℃ for 30 minutes to obtain a coating film. The resulting coating film was measured by a Super xenon weather meter SX75 (manufactured by Suga Test Instruments Co., ltd.) at a light intensity of 180 DEGW/m ² The black panel was kept at 63 ℃ for 7000 hours, and a weather resistance test was performed. The gloss at 60 ° of the coating film at the start of the measurement (0 hours) and after 7000 hours was measured with a gloss meter UGV-6P (manufactured by Suga Test Instruments co., ltd.) and the ratio of the gloss at 60 ° of the coating film after 7000 hours to the gloss at 60 ° of the coating film at the start of the measurement (0 hours) was calculated as a gloss retention ratio (%). The evaluation criteria were as follows.

(evaluation criteria)

Very good: gloss retention of 85% or more:

good: the gloss retention is 80% or more and less than 85%

And (delta): the gloss retention is 70% or more and less than 80%

X: gloss retention of less than 70%

Synthesis example 1 Synthesis of polyisocyanate P-1

The inside of a four-necked flask equipped with a stirrer, a thermometer, and a condenser was replaced with nitrogen, and HDI:1000g and isobutanol: 0.2g. After the temperature in the reactor reached 70 ℃ under stirring, ammonium tetramethyloctanoate as a catalyst for urethanation/allophanation/isocyanuratement was added to the reactor: 0.03g. Next, when the change in refractive index of the reaction solution became 0.010, an 85% phosphoric acid aqueous solution: 0.04g, stop the reaction. The reaction solution was further kept at 90 ℃ for 1 hour to completely deactivate the catalyst. After the reaction solution was filtered, unreacted HDI was removed by a flow-down thin film distillation apparatus to obtain polyisocyanate P-1.

The resulting polyisocyanate P-1 was a transparent liquid having a yield of 250g, a viscosity of 1500 mPas and an NCO content of 22.8%. The yield thereof was found to be 25%. The Nuclear Magnetic Resonance (NMR) of the polyisocyanate P-1 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 2/98.

Synthesis example 2 Synthesis of polyisocyanate P-2

In the same apparatus as in synthesis example 1, HDI:1000g and 2-ethyl-1-hexanol: 2g of the total weight. After the temperature in the reactor reached 70 ℃ under stirring, N, N, N-trimethyl-N-benzylammonium hydroxide as a catalyst for urethanization/allophanatization/isocyanuric acid esterification was added to the reactor: 0.03g. Next, when the change in refractive index of the reaction solution became 0.020, an 85% aqueous solution of phosphoric acid: 0.03g, the reaction was stopped. The reaction solution was further kept at 100 ℃ for 1 hour to completely deactivate the catalyst. And filtering the reaction liquid, and removing unreacted HDI by using a flow-down thin film distillation device to obtain the polyisocyanate P-2.

The obtained polyisocyanate P-2 was a transparent liquid having a yield of 480g, a viscosity of 3000 mPas and an NCO content of 21.0%. NMR of the polyisocyanate P-2 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 5/95.

Synthesis example 3 Synthesis of polyisocyanate P-3

In the same apparatus as in synthesis example 1, HDI:1000g and 2-ethyl-1-hexanol: 20g of carbamate were reacted at a temperature of 90 ℃ for 1 hour in a reactor with stirring. After carbamation, tetramethylammonium octanoate as an allophanatization-isocyanation catalyst: 0.01g. Next, when the change in refractive index of the reaction solution became 0.01, an 85% phosphoric acid aqueous solution: 0.03g, the reaction was stopped. The reaction mixture was further kept at 100 ℃ for 1 hour to completely deactivate the catalyst. And filtering the reaction liquid, and removing unreacted HDI by using a flow-down type thin film distillation device to obtain the polyisocyanate P-3.

The resulting polyisocyanate P-3 was a transparent liquid, had a yield of 350g, a viscosity of 800 mPas and an NCO content of 22.0%. NMR of the polyisocyanate P-3 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 18/82.

Synthesis example 4 Synthesis of polyisocyanate P-4

In the same apparatus as in synthesis example 1, HDI:1000g and tridecanol: 2g of the total weight. After the temperature in the reactor reached 70 ℃ under stirring, N, N, N-trimethyl-N-benzylammonium hydroxide as a catalyst for urethanation, allophanation and isocyanuric acid esterification was added to the reactor: 0.03g. Next, when the change in refractive index of the reaction solution became 0.020, an 85% aqueous solution of phosphoric acid: 0.03g, the reaction was stopped. The reaction mixture was further kept at 100 ℃ for 1 hour to completely deactivate the catalyst. And filtering the reaction liquid, and removing unreacted HDI by using a flow-down thin film distillation device to obtain the polyisocyanate P-4.

The resulting polyisocyanate P-4 was a transparent liquid, had a yield of 500g, a viscosity of 3200 mPas and an NCO content of 21.2%. NMR of the polyisocyanate P-4 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 5/95.

Synthesis example 5 Synthesis of polyisocyanate P-5

In the same apparatus as in synthesis example 1, HDI:1000g and stearyl alcohol: 2g of the total weight of the composition. After the temperature in the reactor reached 70 ℃ under stirring, tetramethylammonium octanoate as an allophanatization-isocyanation catalyst was added to the reactor: 0.01g. Next, when the change in refractive index of the reaction solution became 0.020, an 85% aqueous solution of phosphoric acid: 0.03g, the reaction was stopped. The reaction solution was further kept at 100 ℃ for 1 hour to completely deactivate the catalyst. And filtering the reaction solution, and removing unreacted HDI by using a flow-down thin film distillation device to obtain the polyisocyanate P-5.

The obtained polyisocyanate P-5 was a transparent liquid having a yield of 450g, a viscosity of 2800 mPas and an NCO content of 21.5%. NMR of polyisocyanate P-5 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 5/95.

[ Synthesis example 6] Synthesis of polyisocyanate P-6

In the same apparatus as in synthesis example 1, HDI:1000g and 2-ethyl-1-hexanol: 2g of the total weight. After the temperature in the reactor reached 70 ℃ under stirring, tetramethylammonium octylate as a urethane-allophanate-isocyanurate catalyst was added to the reactor: 0.01g. Next, when the change in refractive index of the reaction solution became 0.080, an 85% phosphoric acid aqueous solution: 0.03g, the reaction was stopped. The reaction mixture was further kept at 160 ℃ for 1 hour to completely deactivate the catalyst. And filtering the reaction liquid, and removing unreacted HDI by using a flow-down thin film distillation device to obtain the polyisocyanate P-6.

The obtained polyisocyanate P-6 was a transparent liquid having a yield of 200g, a viscosity of 600 mPas and an NCO content of 23.0%. NMR of the polyisocyanate P-6 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 2/98.

Synthesis example 7 Synthesis of polyisocyanate P-7

In the same apparatus as in synthesis example 1, HDI:800g, IPDI:200g and tridecanol: 10g of carbamate was reacted at a temperature of 90 ℃ for 1 hour in the reactor with stirring. After the urethanization, N-trimethyl-N-benzylammonium hydroxide was added to the reactor as allophanatization-isocyanation catalyst: 0.03g. Next, at the time when the change in refractive index of the reaction solution became 0.012, an 85% phosphoric acid aqueous solution: 0.03g, the reaction was stopped. The reaction mixture was further kept at 100 ℃ for 1 hour to completely deactivate the catalyst. After the reaction solution was filtered, unreacted HDI was removed by a flow-down thin film distillation apparatus to obtain polyisocyanate P-7.

The obtained polyisocyanate P-7 was a transparent liquid having a yield of 300g, a viscosity of 5000 mPas and an NCO content of 19.0%. NMR of the polyisocyanate P-7 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 10/90.

Synthesis example 8 Synthesis of polyisocyanate P-8

In the same apparatus as in synthesis example 1, HDI:1000g and tridecanol: 30g of carbamate were reacted at a temperature of 90 ℃ for 1 hour in the reactor with stirring. After carbamation, tetramethylammonium octanoate as an allophanatization-isocyanation catalyst: 0.01g. Next, when the change in refractive index of the reaction solution became 0.01, an 85% phosphoric acid aqueous solution: 0.03g, the reaction was stopped. The reaction solution was further kept at 100 ℃ for 1 hour to completely deactivate the catalyst. And (3) filtering the reaction solution, and removing unreacted HDI by using a flow-down type thin film distillation device to obtain the polyisocyanate P-8.

The obtained polyisocyanate P-8 was a transparent liquid having a yield of 300g, a viscosity of 600 mPas and an NCO content of 20.5%. NMR of the polyisocyanate P-8 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 30/70.

Synthesis example 9 Synthesis of polyisocyanate P-9

In the same apparatus as in synthesis example 1, HDI:1000g and 2-ethyl-1-hexanol: 30g of carbamate was reacted at a temperature of 90 ℃ for 1 hour in the reactor with stirring. After the urethanization, N-trimethyl-N-benzylammonium hydroxide was added to the reactor as allophanatization-isocyanation catalyst: 0.01g. Next, when the change in refractive index of the reaction solution became 0.008, an 85% phosphoric acid aqueous solution: 0.03g, the reaction was stopped. The reaction mixture was further kept at 100 ℃ for 1 hour to completely deactivate the catalyst. And filtering the reaction liquid, and removing unreacted HDI by using a flow-down thin film distillation device to obtain the polyisocyanate P-9.

The resulting polyisocyanate P-9 was a transparent liquid having a yield of 200g, a viscosity of 400 mPas and an NCO content of 20.2%. NMR of the polyisocyanate P-9 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 50/50.

Synthesis example 10 Synthesis of polyisocyanate P-10

In the same apparatus as in synthesis example 1, HDI:1000g and 2-ethyl-1-hexanol: 100g, with stirring, were carbamated at 130 ℃ for 1 hour. After carbamation, a 20% solution of mineral spirits of zirconium 2-ethylhexanoate was added to the reactor as allophanatization catalyst: 0.42g. After 60 minutes, when the refractive index of the reaction solution increased to 0.0055, a 2-ethyl-1-hexanol solution (obtained by diluting 2-ethyl-1-hexanol, a product name of "phosphoric acid (105%)" manufactured by taihei chemical industries, which is a product of "chemical industries" and contains 10% of the solid content of pyrophosphoric acid): 3.9g, stop the reaction. Next, in the same manner as in Synthesis example 1, unreacted HDI was removed to obtain polyisocyanate P-10.

The resulting polyisocyanate P-10 was a transparent liquid having a yield of 200g, a viscosity of 100 mPas and an NCO content of 17.0%. NMR of the polyisocyanate P-10 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 95/5.

Synthesis example 11 Synthesis of polyisocyanate P-11

In the same apparatus as in Synthesis example 1, polyisocyanate P-1:85g, and "MPG (trade name)" (number of repeating units of methoxypolyethylene glycol and ethylene oxide =4.2, manufactured by Nippon emulsifier Co., ltd.): 6.4g of the polyisocyanate was mixed with 8.6g of "TN555 (trade name)" (number of methoxypolyethylene glycol and ethylene oxide repeating units =9.0, manufactured by Nippon emulsifier Co., ltd.), and reacted at 120 ℃ for 4 hours under stirring to obtain polyisocyanate P-11.

The obtained polyisocyanate P-11 was a transparent liquid having a viscosity of 1800 mPas and an NCO content of 17.5%. NMR of the polyisocyanate P-11 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 2/98.

Synthesis example 12 Synthesis of polyisocyanate P-12

In the same apparatus as in Synthesis example 1, polyisocyanate P-2:85g, and MPG:6.4g, and TN555:8.6g of the mixture was mixed and reacted at 120 ℃ for 4 hours under stirring to obtain polyisocyanate P-12.

The resulting polyisocyanate P-12 was a transparent liquid, had a viscosity of 3200 mPas and an NCO content of 16.0%. NMR of the polyisocyanate P-12 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 5/95.

Synthesis example 13 Synthesis of polyisocyanate P-13

In the same apparatus as in Synthesis example 1, polyisocyanate P-3:82g, and MPG:12g, and TN555:8g were mixed and reacted at 120 ℃ for 4 hours under stirring to obtain polyisocyanate P-13.

The obtained polyisocyanate P-13 was a transparent liquid, had a viscosity of 1000 mPas and an NCO content of 15.4%. NMR of the polyisocyanate P-13 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 18/82.

Synthesis example 14 Synthesis of polyisocyanate P-14

In the same apparatus as in Synthesis example 1, polyisocyanate P-4:85g, and TN555:15g were mixed and reacted at 120 ℃ for 4 hours under stirring to obtain polyisocyanate P-14.

The obtained polyisocyanate P-14 was a transparent liquid having a viscosity of 3500 mPas and an NCO content of 16.5%. NMR of the polyisocyanate P-14 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 5/95.

Synthesis example 15 Synthesis of polyisocyanate P-15

In the same apparatus as in Synthesis example 1, polyisocyanate P-5:90g, and "MPG081 (trade name)" (number of repeating units of methoxypolyethylene glycol and ethylene oxide =15.0, manufactured by Nippon emulsifier Co., ltd.): 10g of the polyisocyanate was mixed and reacted at 120 ℃ for 4 hours under stirring to obtain polyisocyanate P-15.

The resulting polyisocyanate P-15 was a transparent liquid having a viscosity of 3000 mPas and an NCO content of 18.7%. NMR of the polyisocyanate P-15 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 5/95.

Synthesis example 16 Synthesis of polyisocyanate P-16

In the same apparatus as in Synthesis example 1, polyisocyanate P-6:80g, and MPG:8.6g, and TN555:11.4g were mixed and reacted at 120 ℃ for 4 hours under stirring to obtain polyisocyanate P-16.

The resulting polyisocyanate P-16 was a transparent liquid having a viscosity of 700 mPas and an NCO content of 15.9%. NMR of the polyisocyanate P-16 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 2/98.

Synthesis example 17 Synthesis of polyisocyanate P-17

In the same apparatus as in Synthesis example 1, polyisocyanate P-7:90g, and TN555:10g of the mixture was mixed and reacted at 120 ℃ for 4 hours under stirring to obtain polyisocyanate P-17.

The obtained polyisocyanate compound was a transparent liquid, had a viscosity of 6000 mPas and an NCO content of 16.1%. NMR of the polyisocyanate P-17 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 10/90.

Synthesis example 18 Synthesis of polyisocyanate P-18

In the same apparatus as in Synthesis example 1, polyisocyanate P-8:85g, MPG:6.4g, and TN555:8.6g of the resulting mixture was mixed and reacted at 120 ℃ for 4 hours under stirring to obtain polyisocyanate P-18.

The resulting polyisocyanate P-18 was a transparent liquid having a viscosity of 800 mPas and an NCO content of 15.6%. NMR of the polyisocyanate P-18 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 30/70.

Synthesis example 19 Synthesis of polyisocyanate P-19

In the same apparatus as in Synthesis example 1, polyisocyanate P-9:80g, and MPG:8.6g, and TN555:11.4g were mixed and reacted at 120 ℃ for 4 hours under stirring to obtain polyisocyanate P-19.

The resulting polyisocyanate P-19 was a transparent liquid having a viscosity of 450 mPas and an NCO content of 13.7%. NMR of the polyisocyanate P-19 was measured, and as a result, the molar ratio of allophanate groups to isocyanurate groups was 50/50.

The physical properties of the polyisocyanates P-1 to P-20 synthesized in Synthesis examples 1 to 19 are summarized in tables 1 and 2 below.

[ Table 1]

[ Table 2]

Examples 1 to 40, 61 to 68 and comparative examples 1 to 6

1. Production of polyisocyanate compositions S-a1 to S-a48 and S-b1 to S-b6

The types of polyisocyanate and modifier having an active hydrogen-containing group were used in combination as described in tables 3 to 6, 9 and 11, in the following formula: 50g of the polyisocyanate composition was prepared by mixing a modifier having an active hydrogen-containing group so that the isocyanate group content of the polyisocyanate became 10mol%, and reacting the mixture at 120 ℃ for 3 hours. In comparative examples 3 to 6, the polyisocyanate was used as it is as the polyisocyanate composition without mixing the modifier having an active hydrogen-containing group. The NCO%, viscosity and AA-SP values are shown in tables 3 to 6, 9 and 11.

2. Production of coating compositions

A fluoro polyol (trade name "ZEFFLE GK580" manufactured by Daikin Industries, ltd., product name), a resin component concentration of 50%, and a hydroxyl value of 42mgKOH/g, and each of the polyisocyanate compositions obtained in "1." were compounded so that the molar ratio of isocyanate groups/hydroxyl groups became 1.0. Further, the mixed solution was adjusted to 50% by mass of solid content with HAWS (High Aromatic White Spirit) (manufactured by Shell Japan, aniline Point 17 ℃ C.) to obtain each coating composition. The obtained coating composition was subjected to various evaluations by the methods described above. The results are shown in tables 3 to 6, 9 and 11.

Examples 41 to 60, 69 to 72 and comparative examples 7 to 9

1. Production of blocked polyisocyanate compositions B-a1 to B-a24 and B-B1 to B-B3

The polyisocyanate compositions and the kinds of blocking agents were used in combinations described in tables 7, 8, 10 and 12, in the polyisocyanate compositions: 50g of the polyisocyanate composition was mixed with a blocking agent in an amount of 1.02 mol per one isocyanate group of the polyisocyanate composition, and butyl acetate: 30g, held at 60 ℃. It was confirmed that the isocyanate content was 0.1% or less, and each blocked polyisocyanate composition was obtained.

2. Production of coating compositions

Each of the coating compositions was obtained by blending a fluoro polyol (trade name "ZEFFLE GK580" from Daikin Industries, ltd., resin component concentration 50%, hydroxyl value 42 mgKOH/g) and each of the blocked polyisocyanate compositions obtained in "1." so that the molar ratio of isocyanate group/hydroxyl group became 1.0, and further adjusting the solid content to 50 mass% with butyl acetate. The obtained coating composition was subjected to various evaluations by the methods described above. The results are shown in tables 7, 8, 10 and 12.

In tables 3 to 12 below, the details of the modifying agent having an active hydrogen-containing group are as follows.

LEOCON 1015H: trade name, lion Corporation, number average molecular weight 800, polyoxypropylene 2-ethylhexyl ether, hydroxyl number 1

Excenol 2020: trade name, asahi glass company Limited, polypropylene glycol, number average molecular weight 2000, hydroxyl number 2

Excenol 3020: trade name, asahi glass company, asahi glass Co., ltd., polypropylene glycol, number average molecular weight 3000, hydroxyl number 2

Excenol 851: trade name, manufactured by Asahi glass company Limited, polyoxypropylene triol (terminal ethylene oxide addition), number average molecular weight 6700, hydroxyl number 3

C4: isobutanol, number average molecular weight 74, hydroxyl number 1

C8: 2-ethyl-1-hexanol, number average molecular weight 130, hydroxyl number 1

C13: tridecanol, number average molecular weight 200, hydroxyl number 1

C20: icosanol, number average molecular weight 298, hydroxyl number 1

Reminol 7012: trade name, manufactured by Asahi glass company Limited, polyoxypropylene triol (terminal ethylene oxide addition), number average molecular weight 10000, hydroxyl number 3

Polycaprolactone diol: a compound represented by the following general formula (9), a number average molecular weight of 2000, and a hydroxyl number of 2

HO-[(CH ₂ ) ₅ -COO] _n21 -(CH ₂ ) ₅ -OH (9)

(in the general formula (9), n21 is about 16.3.)

Polycarbonate diol: a compound represented by the following general formula (10), a number average molecular weight of 2000, and a hydroxyl number of 2

HO-[(CH ₂ ) ₆ -O(CO)O] _n22 -(CH ₂ ) ₆ -OH (10)

(in the general formula (10), n22 is about 13.1.)

In addition, oxypropylene means, [ -O-CH (CH) ₃ )CH ₂ -]The groups shown.

[ Table 3]

[ Table 4]

[ Table 5]

[ Table 6]

[ Table 7]

[ Table 8]

[ Table 9]

[ Table 10]

[ Table 11]

[ Table 12]

According to tables 3 to 10, the polyisocyanate compositions S-a1 to S-a48 (examples 1 to 40 and 61 to 68) having an AA-SP value of 13.0 or less exhibited good gloss, image clarity, hardness and weather resistance when formed into coating films. Further, the blocked polyisocyanate compositions B-a1 to B-a24 (examples 41 to 60 and 69 to 72) obtained from the polyisocyanate compositions having an AA-SP value of 13.0 or less exhibited good gloss, image clarity, hardness and weather resistance when formed into coating films.

In the polyisocyanate compositions S-a1 to S-a13, S-a17 to S-a20, S-a28 to S-a34, S-a37, S-a38 and S-a41 to S-a48 (examples 1 to 13, 17 to 20, 28 to 34, 37, 38, 61 to 68) using polyisocyanates having different molar ratios of allophanate groups to isocyanurate groups, the polyisocyanate compositions S-a1 to S-a13, S-a17 to S-a20, S-a28 to S-a34, S-a37 and S-a38 (examples 1 to 13, 17 to 20, 28 to 34, 37 and 38) having an allophanate group to isocyanurate group molar ratio of 10/90 or less had particularly good hardness and weather resistance. In addition, in the blocked polyisocyanate compositions B-a1 to B-a5, B-a7 to B-a14, B-a16 to B-20 and B-a21 to B-a24 (examples 41 to 45, 47 to 54, 56 to 60 and 69 to 72) obtained from these polyisocyanate compositions, similarly, the blocked polyisocyanate compositions B-a1 to B-a5, B-a7 to B-a14 and B-a16 to B-20 (examples 41 to 45, 47 to 54 and 56 to 60) in which the molar ratio of allophanate groups to isocyanurate groups is 10/90 or less exhibited particularly good hardness and weather resistance when they were formed into coating films.

In polyisocyanate compositions S-a6 to S-a9, S-a11, S-a12, S-a14 and S-a16 (examples 6 to 9, 11, 12, 14 and 16) using different types of modifiers having active hydrogen-containing groups, R was used ¹¹ The polyisocyanate compositions S-a6 to S-a9, S-a11 and S-a12, which are oxypropylene and have a modifier with an active hydrogen-containing group having a molecular weight of 3000 or less, are particularly excellent in hardness.

Using Y ¹¹ In the polyisocyanate compositions S-a17, S-a18, S-a21, S-a22, S-a24 and S-a26 (examples 17, 18, 21, 22, 24 and 26) having modifiers having active hydrogen-containing groups with different carbon numbers, the gloss in the formation of a coating film was particularly good in the polyisocyanate compositions S-a17, S-a18, S-a21 and S-a22 using modifiers having active hydrogen-containing groups with a carbon number of 13 or more.

In the polyisocyanate compositions S-a14 and S-a36 (examples 14 and 36) and the blocked polyisocyanate compositions B-a6 and B-a15 (examples 46 and 55) using these polyisocyanate compositions, the hardness at the time of forming a coating film was improved for the blocked polyisocyanate compositions B-a6 and B-a15 (examples 46 and 55).

In polyisocyanate compositions S-a30, S-a35 and S-a36 (examples 30, 35 and 36) using different kinds of modifiers having active hydrogen-containing groups, for the use of R ¹¹ Polyisocyanate composition S-a30 (example 30) which is 2-ethylhexyl LEOCON 1015H having a molecular weight of 800 as a modifier having an active hydrogen-containing group exhibited particularly good hardness when a coating film was formed. In addition, among the polyisocyanate compositions S-a35 and S-a36 (examples 35 and 36) using the modifiers having active hydrogen-containing groups which are identical in structure but different in molecular weight, the polyisocyanate composition S-a36 (example 36) having a molecular weight of 6700 of the modifier having active hydrogen-containing groups was particularly excellent in gloss and image clarity at the time of forming a coating film.

On the other hand, according to tables 11 to 12, with respect to the polyisocyanate compositions S-b1 and S-b2 (comparative examples 1 and 2) having an AA-SP value exceeding 13.0, the hardness at the time of forming a coating film was good, but the gloss, the image clarity and the weather resistance were poor. In addition, the polyisocyanate compositions S-b3 to S-b6 (comparative examples 3 to 6) which did not use a modifier having an active hydrogen-containing group exhibited good hardness when formed into a coating film, but exhibited poor gloss, image clarity and weather resistance. Further, in the blocked polyisocyanate compositions B-B1 to B-B3 (comparative examples 7 to 9) obtained from these polyisocyanate compositions, similarly, the gloss, the distinctness of image, the hardness and the weather resistance were not all excellent at the time of forming a coating film.

Industrial applicability

The polyisocyanate composition of the present embodiment has low polarity and excellent compatibility with various solvents and main agents. The coating composition of the present embodiment can be used as a coating material for roll coating, curtain coating, spray coating, spin-cup coating, electrostatic coating, and the like. The coating composition of the present embodiment can be used as a primer or a top coat for a material such as metal, plastic, wood, a film, or an inorganic material. The coating composition of the present embodiment is also useful as a coating material for imparting heat resistance, aesthetic properties (surface smoothness, clarity), and the like to precoated metal including rust-proof steel sheets, automobile coating, and the like. The coating composition of the present embodiment is also useful as a urethane material for adhesives, pressure-sensitive adhesives, elastomers, foams, surface-treating agents, and the like.

Claims

1. A polyisocyanate composition comprising the reaction product of a polyisocyanate and a modifier having an active hydrogen-containing group, which reaction product has an AA-SP value of 13.0 or less,

wherein the polyisocyanate satisfies the following (A) and (B),

(B) The molar ratio of allophanate groups to isocyanurate groups is 2/98 to 25/75,

the modifier having an active hydrogen-containing group is a compound represented by the following general formula (1-1), (1-2) or (2-1),

H-(CH ₂ ) _m111 -OH (1-1)

H-(O-R ¹²¹ ) _m121 -OH (1-2)

R ²¹¹ -((O-R ²¹² ) _m211 -OH) _n211 (2-1)

in the general formula (1-1), m111 is 1 or more and 300 or less,

in the general formula (1-2), m121 is 1 to 300, R ¹²¹ An alkylene group having 1 to 4 carbon atoms,

in the general formula (2-1), m211 is 1 or more and 300 or less, n211 is an integer of 2 or more and 3 or less, R ²¹¹ Is a saturated hydrocarbon group having n211 valency and having 1 to 8 carbon atoms, R ²¹² Is an alkylene group having 1 to 4 carbon atoms.

2. The polyisocyanate composition of claim 1 wherein the polyisocyanate further satisfies the following (C),

(C) Having structural units derived from hydrophilic compounds.

3. The polyisocyanate composition according to claim 2, wherein the hydrophilic compound is a nonionic hydrophilic compound comprising repeating units of 1 or more hydroxyl groups and 1 or more and 50 or less oxyethylene groups.

4. The polyisocyanate composition according to any one of claims 1 to 3, wherein a part or all of the isocyanate groups of the reaction product are blocked by a blocking agent.

5. The polyisocyanate composition according to claim 4, wherein the blocking agent is at least 1 compound selected from the group consisting of methyl ethyl ketoxime and 3, 5-dimethylpyrazole.

6. A coating composition comprising: the polyisocyanate composition of any one of claims 1 to 5; and a polyol having a hydroxyl value of not less than 10mgKOH/g and not more than 200 mgKOH/g.

7. The coating composition of claim 6, wherein the polyol comprises a fluorinated polyol.

8. A coating film obtained by curing the coating composition according to claim 6 or 7.