KR102458385B1 - Urethan coating composition, cured coating film and resin member - Google Patents

Abstract

(Project) To provide a one-component urethane coating composition capable of forming a cured coating film having excellent antifogging durability while having good scratch resistance, and a resin member having the cured coating film.
(Solution) A urethane coating composition comprising a specific amount of a polyisocyanate (a), a polyether polyol (b), and a surfactant (c), wherein the polyether polyol (b) has a number average molecular weight of 300 or more a polyether polyol (b-1) having a number average molecular weight of less than 600, a polyether polyol (b-2) having a number average molecular weight of 600 or more and less than 900, and a polyether polyol (b-3) having a number average molecular weight of 900 or more and 1800 or less; The active agent (c) is an ionic surfactant having a hydroxyl group in the molecule and an anionic surfactant and/or an amphoteric surfactant that does not have a reactive group with an isocyanate group.

Description

Urethane coating composition, cured coating film, and resin member TECHNICAL FIELD

The present invention relates to a urethane coating composition, a cured coating film, and a resin member.

Conventionally, when the surface of a base material, such as a synthetic resin molded article or glass, becomes below the dew point temperature, it is known that moisture in the air becomes fine water droplets and adheres to the surface of the base material. As a result, scattering of light by the attached water droplet occurs and blurring occurs. For example, when the above-mentioned base material is used for glasses or the like, the field of view is obstructed.

A method of forming a coating film (dry coating film or cured coating film) by coating a solution in which a hydrophilic resin, a surfactant, etc. are mixed on the surface of a substrate as a method for preventing the occurrence of the fogging (anti-fogging) is known. .

In this method, the antifogging effect is expressed because the surfactant contained in the coating film lowers the contact angle of the adhering water drop and does not cause light scattering. Moreover, in this method, since the fall of the contact angle of the water droplet by surfactant occurs rapidly, the antifogging effect can be expressed rapidly.

However, when the actual use of the coating film is considered (for example, when the coating film is used for a long period of time, or when the surface of the coating film is wiped with water, etc.), the surfactant in the interior of the coating film flows out easily, and the antifogging property is deteriorated. On the other hand, by adding a large amount of surfactant, although antifogging durability can be improved to some extent, it cannot improve significantly, and there exists a problem that a coating film becomes easily damaged, and the external appearance of a coating film also falls.

In order to prevent the outflow of such surfactants, a method using a surfactant that is not readily soluble in water (Patent Document 1) and a method using a reactive surfactant (Patent Documents 2 and 3) have been reported.

Japanese Laid-Open Patent Publication No. 2015-86370 Japanese Laid-Open Patent Publication No. 2005-29723 Japanese Patent Laid-Open No. 2004-244612

Since the cured coating film disclosed by patent document 1 has low water solubility of surfactant, even if it immerses in water, since surfactant does not flow out in water, antifogging continuity is expectable. Moreover, since it is estimated that many surfactant exists in the outermost surface of a coating film, a uniform water film can be formed. However, when the antifogging coating film was wet-wiped, there was a concern that the surfactant present on the outermost surface of the coating film would come off, and good antifogging properties could not be maintained.

On the other hand, in the cured coating film disclosed in Patent Documents 2 and 3, a reactive surfactant having a functional group that reacts with the isocyanate component is introduced into a two-component curable resin containing an isocyanate component and a polyol component. can be covalently bonded, so even when the coating film is immersed in water, there is little outflow of the surfactant, and antifogging continuity can be expected. However, it turned out that since the said reactive surfactant is monofunctional, the crosslinking density in a coating film falls, and there exists a problem that abrasion resistance becomes inadequate. On the other hand, when the usage-amount of the said reactive surfactant was made into the minimum amount which can maintain abrasion resistance, it turned out that antifogging property and antifogging continuity are not expressed.

As described above, during actual use of the coating film (dry coating film or cured coating film) in the prior art, problems such as a decrease in antifogging properties or a decrease in appearance due to occurrence of scratches still exist. Therefore, the antifogging coating film which can express favorable antifogging property even after repeated wet-wiping of the coating film surface while maintaining the film strength which can express favorable abrasion resistance is calculated|required.

Moreover, since the reaction of an isocyanate component and a polyol component advances in a two-part curable resin composition containing an isocyanate component and a polyol component, there exists a problem that the usable time (pot life) is limited. Accordingly, there is a demand for a composition (product) having a long pot life or a one-component type.

An object of the present invention is to provide a one-component urethane coating composition capable of forming a cured coating film having excellent antifogging durability while having good scratch resistance, and a resin member having the cured coating film.

The present invention provides a urethane coating composition comprising a polyisocyanate (a), a polyether polyol (b), and a surfactant (c), wherein the polyisocyanate (a) is selected from the group consisting of diisocyanate and derivatives thereof. A blocked polyisocyanate compound obtained by reacting at least one polyisocyanate compound with a thermally dissociable blocking agent, wherein the polyether polyol (b) is a polyether polyol (b-1) having a number average molecular weight of 300 or more and less than 600; a polyether polyol (b-2) having a number average molecular weight of 600 or more and less than 900, and a polyether polyol (b-3) having a number average molecular weight of 900 or more and 1800 or less, wherein the surfactant (c) is an ion having a hydroxyl group in the molecule It is an anionic surfactant and/or amphoteric surfactant which does not have a reactive group with an anionic surfactant and an isocyanate group, WHEREIN: In the total weight of said (a)-(c) component, said (a) component is 35 weight% or more, 85% by weight or less, the component (b-1) is 3% by weight or more and 18% by weight or less, the component (b-2) is 8% by weight or more and 38% by weight or less, and the component (b-3) is It relates to a urethane coating composition characterized in that the content is 0.5 wt% or more and 8 wt% or less, and the component (c) is 1 wt% or more and 10 wt% or less.

Further, the present invention relates to a cured coating film formed from the urethane coating composition.

Moreover, this invention has the said cured coating film, It relates to the resin member characterized by the above-mentioned.

The urethane coating composition of this invention is a urethane coating composition containing specific polyisocyanate (a), polyether polyol (b), and surfactant (c) in specific amounts. Since the polyether polyol (b) uses polyether polyols (b-1), (b-2) and (b-3) having different number average molecular weights, the crosslinked structure of the cured coating film formed from the composition Since it is estimated that a fine balance of

Moreover, this invention uses together the ionic surfactant which has a hydroxyl group in a molecule|numerator, and an anionic surfactant and/or amphoteric surfactant which does not have a reactive group with an isocyanate group as said surfactant (c). The ionic surfactant which has a hydroxyl group in a molecule|numerator, and the anionic surfactant and/or amphoteric surfactant which do not have a reactive group with an isocyanate group can improve initial stage antifogging property, respectively. In addition, when used alone, when both surfactant components that are easily dike from the cured coating film coexist, an aggregate is formed and it becomes difficult to dike, so it is estimated that antifogging durability can be improved.

The urethane coating composition of the present invention contains a polyisocyanate (a), a polyether polyol (b), and a surfactant (c).

<Polyisocyanate (a)>

The polyisocyanate (a) of the present invention is a blocked polyisocyanate compound obtained by reacting at least one polyisocyanate compound selected from the group consisting of diisocyanate and derivatives thereof with a thermally dissociable blocking agent. The said polyisocyanate (a) may be used individually, respectively, and may mix and use 2 or more types.

As said diisocyanate, For example, Aliphatic diisocyanate, such as 1, 6- hexamethylene diisocyanate; alicyclic diisocyanates such as 1,3-bis(isocyanatomethyl)cyclohexane, isophorone diisocyanate, and 4,4'-dicyclohexylmethane diisocyanate; Aromatic diisocyanate, such as xylylene diisocyanate, tolylene 2, 6- diisocyanate, and diphenylmethane diisocyanate, etc. are mentioned. As the derivative of the diisocyanate, for example, a compound synthesized from the above aliphatic diisocyanate, alicyclic diisocyanate, and/or aromatic diisocyanate as a starting material, a biuret body, an adduct body with trimethylolpropane, Derivatives of aliphatic diisocyanates, such as an isocyanurate body and an allophanate body, the derivative of alicyclic diisocyanate, the derivative of aromatic diisocyanate, etc. are mentioned. The said polyisocyanate compound may be used individually, respectively, and may mix and use 2 or more types.

From the viewpoint of increasing the crosslinking density of the cured coating film and improving scratch resistance, the polyisocyanate compound is preferably a derivative of an aliphatic diisocyanate, a derivative of an alicyclic diisocyanate, or an aromatic diisocyanate, a derivative of an aliphatic diisocyanate, A derivative of alicyclic diisocyanate is more preferable, and a derivative of 1,6-hexamethylene diisocyanate and a derivative of isophorone diisocyanate are still more preferable.

The said blocked polyisocyanate compound is obtained by making the said polyisocyanate compound and a thermally dissociable blocking agent react. The said thermally dissociable blocking agent is a compound which blocks (protects) the isocyanate group of the said polyisocyanate compound. In addition, "thermal dissociation property" means the property which dissociates from a blocked polyisocyanate compound by heating.

The thermal dissociation blocking agent is a compound having one active hydrogen in a molecule, for example, an alcohol-based compound, an alkylphenol-based compound, a phenol-based compound, an active methylene-based compound, a mercaptan-based compound, an acid amide-based compound , an acid imide compound, an imidazole compound, a urea compound, an oxime compound, an amine compound, an imide compound, a pyrazole compound, and the like. The said thermally dissociable blocking agent may be used individually, respectively, and may mix and use 2 or more types.

Examples of the alcohol-based compound include methanol, ethanol, 2-propanol, n-butanol, sec-butanol, 2-ethyl-1-hexanol, 2-methoxyethanol, 2-ethoxyethanol, 2- Butoxyethanol etc. are mentioned. Examples of the alkylphenol-based compound include n-propylphenol, i-propylphenol, n-butylphenol, sec-butylphenol, t-butylphenol, n-hexylphenol, 2-ethylhexylphenol, and n- monoalkylphenols such as octylphenol and n-nonylphenol; Di-n-propylphenol, diisopropylphenol, isopropylcresol, di-n-butylphenol, di-t-butylphenol, di-sec-butylphenol, di-n-octylphenol, di-2-ethylhexyl and dialkyl phenols such as phenol and di-n-nonyl phenol. Examples of the phenol-based compound include phenol, cresol, ethylphenol, styrenated phenol, and hydroxybenzoic acid ester. Examples of the active methylene compound include dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, and acetylacetone. Examples of the mercaptan-based compound include butyl mercaptan and dodecyl mercaptan. Examples of the acid amide compound include acetanilide, acetate amide, ε-caprolactam, δ-valerolactam, and γ-butyrolactam. Examples of the acid imide compound include succinimide and maleic acid imide. As said imidazole-type compound, imidazole, 2-methylimidazole, etc. are mentioned, for example. Examples of the urea-based compound include urea, thiourea, and ethyleneurea. As said oxime type compound, form aldoxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, cyclohexanone oxime, etc. are mentioned, for example. Examples of the amine-based compound include diphenylamine, aniline, carbazole, di-n-propylamine, diisopropylamine, and isopropylethylamine. As said imine-type compound, ethyleneimine, polyethyleneimine, etc. are mentioned, for example. Examples of the pyrazole-based compound include pyrazole, 3-methylpyrazole, and 3,5-dimethylpyrazole.

As the thermal dissociation blocking agent, from the viewpoint of a low dissociation temperature, the active methylene compound and the pyrazole compound are preferably used, and dimethyl malonate or 3,5-dimethylpyrazole is more preferably used.

From the viewpoint of improving the scratch resistance and antifogging properties of the cured coating film, the blocked polyisocyanate compound is a compound (a1) obtained by reacting the derivative of the aliphatic diisocyanate with the dissociable blocking agent, and a derivative of the alicyclic diisocyanate. It is preferable to use together the compound (a2) obtained by making the said dissociation blocking agent react. When the above (a1) and (a2) are used together, from the viewpoint of improving the scratch resistance of the cured coating film, the weight ratio ((a1)/(a2)) of the above (a1) and (a2) is 0.5 or more It is preferable, and it is more preferable that it is 0.8 or more, and it is preferable that it is 10 or less, It is more preferable that it is 5 or less, It is still more preferable that it is 3 or less.

Although the manufacturing method of the said blocked polyisocyanate compound is not limited at all, Usually, the said polyisocyanate compound and the said thermally dissociable blocking agent are heated and stirred at a temperature of 0-100 degreeC in the presence of a catalyst, and can be obtained by making it react. As said catalyst, For example, Organometallic salts, such as tin, zinc, and lead; Alkali metal alcoholates, such as sodium methylate, are mentioned. In addition, an organic solvent may be used for the reaction, and as the organic solvent, an organic solvent that is inert to an isocyanate group is preferably used, for example, hydrocarbon solvents such as toluene and xylene. .

In the blocked polyisocyanate compound, all isocyanate groups may be blocked, or isocyanate groups may be partially blocked, but from the viewpoint of improving the usable time (pot life) of the urethane coating composition, all isocyanate groups are blocked it is preferable

As a commercially available block polyisocyanate compound, for example, a 1,6-hexamethylene diisocyanate derivative and a block polyisocyanate compound of dimethyl malonate (manufactured by Asahi Kasei Chemicals, trade name: Duranate MF-K60B) , a derivative of 1,6-hexamethylene diisocyanate and a block polyisocyanate compound of dimethyl malonate/3,5-dimethylpyrazole (manufactured by BAXENDEN, trade name: TRIXENE BI7992), a derivative of isophorone diisocyanate and 3,5- The blocked polyisocyanate compound of dimethylpyrazole (The BAXENDEN company make, brand name TRIXENE BI7951) etc. are mentioned.

<Polyether polyol (b)>

The polyether polyol (b) of the present invention comprises at least a polyether polyol (b-1) having a number average molecular weight of 300 or more and less than 600, a polyether polyol (b-2) having a number average molecular weight of 600 or more and less than 900, and It is polyether polyol (b-3) whose average molecular weights are 900 or more and 1800 or less. In addition, the said number average molecular weight can measure the hydroxyl value of polyether polyol (b), and can be calculated|required by following formula. The same applies to the number average molecular weight of the polycaprolactone polyol (e) described later.

Number average molecular weight = hydroxyl value × N × 1,000/56.11

Hydroxyl value: value measured according to 6.4 of JIS K-1577

N: average number of functional groups in polyol (number average number of hydroxyl groups in one molecule of polyol)

The said polyether polyols (b-1), (b-2) and (b-3) are, for example, to polyfunctional alcohols, such as glycerol and pentaerythritol, ethylene oxide, propylene oxide, butylene oxide, tetra The polymer obtained by adding at least 1 sort(s) chosen from the group which consists of alkylene oxides, such as hydrofuran, etc. are mentioned. As said alkylene oxide, it is preferable that ethylene oxide is included, and it is more preferable to add only ethylene oxide. The said polyether polyols (b-1), (b-2) and (b-3) may be used individually, respectively, and may mix and use 2 or more types.

As the polyether polyols (b-1), (b-2) and (b-3), for example, polyethylene glycol, polypropylene glycol polyethylene glycol/polypropylene glycol copolymer polyol, polyoxyethylene glyceryl Ether, polyoxypropylene glyceryl ether, polyoxyethylene polyoxypropylene glyceryl ether, polyoxyethylene polyoxypropylene trimethylol propane, polyoxypropylene diglyceryl ether, pentaerythritol polyoxyethylene ether, polyoxyethylene polyoxy Propylene pentaerythritol ether etc. are mentioned. In particular, the said polyether polyols (b-1), (b-2) and (b-3) are polyoxyethylene glyceryl ether and polyoxypropylene glycerol from a viewpoint of improving the abrasion resistance and antifogging property of a cured coating film. It is preferable to use reel ether, polyoxyethylene polyoxypropylene glyceryl ether, and polyoxypropylene diglyceryl ether.

The polyether polyol (b-1) preferably has a number average molecular weight of 350 or more, more preferably 400 or more, from the viewpoint of improving the scratch resistance of the cured coating film and improving the antifogging property after wiping, and , It is preferable that it is 550 or less, and it is more preferable that it is 500 or less.

The polyether polyol (b-2) preferably has a number average molecular weight of 650 or more, more preferably 700 or more, from the viewpoint of improving the scratch resistance of the cured coating film and improving the antifogging property after wiping, and , it is preferable that it is 850 or less, and it is more preferable that it is 800 or less.

The polyether polyol (b-3) has a number average molecular weight of preferably 1000 or more, more preferably 1200 or more, and preferably 1700 or less, and more preferably 1600 or less, from the viewpoint of improving antifogging properties after water resistance. desirable.

The number of hydroxyl groups per molecule of the polyether polyols (b-1), (b-2) and (b-3) is preferably 2 or more, more preferably 3 or more, from the viewpoint of improving the scratch resistance of the cured coating film. desirable. The number of hydroxyl groups per molecule of the polyether polyols (b-1), (b-2) and (b-3) is preferably 6 or less from the viewpoint of enhancing compatibility with the polyisocyanate (a), 4 It is more preferable that it is the following.

<Surfactant (c)>

Surfactant (c) of this invention is an anionic surfactant and/or amphoteric surfactant which does not have the reactive group with the ionic surfactant which has a hydroxyl group in a molecule|numerator, and an isocyanate group.

The ionic surfactant having a hydroxyl group in the molecule is cationic, anionic, or amphoteric surfactant. The ionic surfactant which has a hydroxyl group in the said molecule|numerator may be used individually, respectively, and may mix and use 2 or more types.

Examples of the ionic surfactant having a hydroxyl group in the molecule include a dialkanolamine salt, a trialkanolamine salt, a polyoxyalkylene alkylamine ether salt, and a fatty acid trialkanolamine ester as a cationic surfactant. Salt, polyoxyalkylene dialkanolamine ether salt, polyoxyalkylene trialkanolamine ether salt, di(polyoxyalkylene)alkylbenzylalkylammonium salt, alkylcarbamoylmethyldi(polyoxyalkylene)ammonium salt, poly An oxyalkylene alkylammonium salt, a polyoxyalkylene dialkyl ammonium salt, etc. are mentioned.

Moreover, in the said ionic surfactant which has a hydroxyl group in the said molecule|numerator, as a cationic surfactant, for example, General formula (1):

R ¹ -NH-(CH ₂ ) _n -N ⁺ R ² R ³ R ⁴ X ^-

(In the general formula (1), R ¹ represents a saturated or unsaturated acyl group having a linear or branched chain having 8 to 24 carbon atoms, and has one or more hydroxyl groups, n represents 1 to 10, R ² to R ⁴ independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, and X represents an anion.);

Examples of the compound represented by the general formula (1) include ricinolamide propyldimethylamine, ricinolamide propylethyldimonium ethosulphate, ricinolamide propyltrimonium chloride, and ricinolamide propyltrimonium methosulfate. Pate, cocamide propyldimethylamine, cocamide propylethyldimonium ethosulphate, cocamide propyltrimonium chloride, behenamidepropyldimethylamine, isostearylamidepropyldimethylamine, stearylamidepropyldimethylamine, quaternium-33 , and undecylenamide propyltrimonium methsulfate.

The ionic surfactant having a hydroxyl group in the molecule is an anionic surfactant, for example, castor oil monosulfate, castor oil monophosphate, sorbitan fatty acid ester sulfate, sorbitan fatty acid ester phosphate, sorbitol fatty acid. Ester sulfate, sorbitol fatty acid ester phosphate, sucrose fatty acid ester sulfate, sucrose fatty acid ester phosphate, polyoxyalkylene castor oil ether monosulfate, polyoxyalkylene castor oil ether monophosphate, polyoxyalkylene sorbitan fatty acid ester sulfate Pate, polyoxyalkylene sorbitan fatty acid ester phosphate, polyoxyalkylene glycerin ether monosulfate, polyoxyalkylene glycerin ether monophosphate, etc. are mentioned.

The ionic surfactant having a hydroxyl group in the molecule is an amphoteric surfactant, for example, N,N-di(β-hydroxyalkyl)N-hydroxyethyl-N-carboxyalkylammonium betaine, N -β-hydroxyalkyl-N,N-dipolyoxyalkylene-N-carboxyalkylammonium betaine, monoester of N-alkyl-N,N-di(polyoxyalkylene)amine with dicarboxylic acid; N-(polyoxyethylene)-N',N'-di(polyoxyethylene)aminoalkyl-N-alkyl-N-sulfoalkylammoniumbetaine, N,N-di(polyoxyethylene)-N-alkyl- N-sulfoalkylammoniumbetaine, N-(β-hydroxyalkylaminoethyl)-N-(β-hydroxyalkyl)aminoethylcarboxylic acid, N,N′-bis(2-hydroxyalkyl)-N ,N'-bis(carboxyethyl)ethylenediamine salt, N-(β-hydroxyalkyl)-N',N'-di(polyoxyethylene)-N-carboxyethylethylenediamine salt, etc. are mentioned.

The ionic surfactant having a hydroxyl group in the molecule is easily compatible with the polyisocyanate (a) and the polyether polyol (b), and is preferably a cationic surfactant from the viewpoint of maintaining a good appearance of the coating film. and the compound represented by the said General formula (1) is more preferable, and ricinolamide propyl ethyldimonium ethosulphate is still more preferable.

The anionic surfactant and/or amphoteric surfactant that does not have a reactive group with the isocyanate group is a surfactant that does not have a hydroxyl group, an amino group, a carboxyl group, an epoxy group, a thiol group, etc. as the reactive group in the molecule of the surfactant to be. The anionic and/or amphoteric surfactant which does not have a reactive group with the said isocyanate group may be used individually, respectively, and may mix and use 2 or more types.

As anionic surfactant which does not have a reactive group with the said isocyanate group, For example, Fatty acid salts, such as sodium oleate and potassium oleate; higher alcohol sulfate esters such as sodium lauryl sulfate and ammonium lauryl sulfate; alkylbenzenesulfonates and alkylnaphthalenesulfonates, such as sodium dodecylbenzenesulfonate and sodium alkylnaphthalenesulfonate; naphthalenesulfonic acid formalin condensate; General formula (2):

[Formula 1]

(In the general formula (2), R ¹ and R ² independently represent a linear or branched alkyl group, the total number of carbon atoms of R ¹ and R ² is 10 or more and 30 or less, M is a hydrogen atom; and alkali metal atom, ammonium group, alkylammonium group, or alkanolammonium group.);

In the succinate-type anionic surfactant, in the general formula (2), the total number of carbon atoms of R ¹ and R ² is preferably 12 or more, more preferably 14 or more, and preferably 24 or less, It is more preferable that it is 20 or less. Moreover, in the said General formula (2), it is preferable that it is an alkali metal atom, an ammonium group, an alkylammonium group, or an alkanolammonium group, and, as for M, it is more preferable that it is an alkali metal atom.

Examples of the succinate-type anionic surfactant include sodium dihexylsulfosuccinate, sodium di-2-ethylhexylsulfosuccinate, ammonium dilaurylsulfosuccinate, etc. Among them, di-2-ethyl Sodium hexylsulfosuccinate is preferred.

As said anionic fluorine-type surfactant, perfluoroalkyl carboxylate, a perfluoroalkyl sulfonate, a perfluoroalkyl phosphate ester, etc. are mentioned, for example.

Examples of the amphoteric surfactant having no reactive group with the isocyanate group include fatty acid type amphoteric surfactants such as dimethylalkyllaurylbetaine and dimethylalkylstearylbetaine, and dimethylalkylsulfobetaine. A sulfonic acid type amphoteric surfactant, an amphoteric fluorochemical surfactant, etc. are mentioned.

As said amphoteric fluorochemical surfactant, perfluoroalkyl betaine etc. are mentioned, for example.

The anionic fluorine-based surfactant and the amphoteric fluorine-based surfactant may have a linear or branched perfluoroalkyl group, but preferably a branched chain, more preferably a branched perfluoroalkenyl group, It is more preferable that it is a branched perfluoro alkenyl group represented by any of the following general formulas (3) - (5).

[Formula 2]

[Formula 3]

[Formula 4]

As the fluorine-based surfactant having a branched perfluoroalkyl group, for example, sodium perfluoroalkenyloxybenzenesulfonate (manufactured by Neos Co., Ltd., trade name: Ftergent 100, trade name: Ftergent 110), perfluoroalkenyl anionic types such as oxybenzylphosphonic acid (manufactured by Neos, trade name: Ftergent 140A) and perfluoroalkenyloxyphenylsulfonyl-N-methyl carboxylate sodium (manufactured by Neos, trade name: Ftergent 150); Both moldings, such as a fluoroalkyl betaine (The Neos Co., Ltd. product, brand name: Ftergent 400S, brand name: Ftergent 400SW), etc. are mentioned.

Moreover, the urethane coating composition of this invention may contain the silicone oil (d) whose HLB is 10-18. By containing the said silicone oil (d), the smoothness of a cured coating film can be improved. Moreover, long-term antifogging sustainability can be improved by using the said silicone oil (d). In addition, HLB (Hydrophilic-Lypophilic Balance) shows the molecular weight of the hydrophilic-group part which occupies for the total molecular weight of surfactant. HLB is calculated|required by Griffin's formula. The said silicone oil (d) may be used individually, respectively, and may mix and use 2 or more types.

As said silicone oil (d), the compound which has a structure in which the hydrocarbon group of the side chain and/or the terminal of a silicone oil was substituted with the organic group is preferable. As said organic group, a polyether group, a long-chain alkyl group, a higher fatty acid ester group, etc. are mentioned, for example, Among these, a polyether group is preferable.

As the polyether group, for example, a polyethyleneoxy group, a polypropyleneoxy group, an ethyleneoxy group (EO), and a propyleneoxy group (trimethyleneoxy group or propane-1,2-diyloxy group; PO) are block-like. or a randomly added polyalkyleneoxy group.

The HLB of the silicone oil (d) is preferably 12 or more from the viewpoint of improving the anti-fogging properties of the cured coating film, and preferably 16 or less from the viewpoint of improving the compatibility with each component in the urethane coating composition.

Examples of the silicone oil (d) include polyether-modified organopolysiloxane (HLB value = 12, manufactured by Shin-Etsu Chemical Industries, Ltd., trade name: KF-642), polyether-modified organopolysiloxane (HLB value = 14, Shin-Etsu). The Chemical Industry Co., Ltd. make, brand name: KF-640), polyether modified organopolysiloxane (HLB value = 12, the Shin-Etsu Chemical Industry Co., Ltd. make, brand name: KF-351A) etc. are mentioned.

The urethane coating composition of the present invention may contain polycaprolactone polyol (e). The polycaprolactone polyol (e) has a number average molecular weight of 300 or more and 1800 or less. By containing the said polycaprolactone polyol (e), the abrasion resistance of a cured coating film can be improved. The said polycaprolactone polyol (e) may be used individually, respectively, and may mix and use 2 or more types. In addition, the said number average molecular weight is computable by the hydroxyl value of polycaprolactone polyol (e) as mentioned above.

The polycaprolactone polyol (e) is a compound obtained by ring-opening polymerization of polyfunctional alcohols such as glycerin and pentaerythritol and ε-caprolactone, polycaprolactonediol, polycaprolactonetriol, polycaprolactonetetraol , polycaprolactone hexaol, and the like.

The number average molecular weight of the polycaprolactone polyol (e) is preferably 400 or more, more preferably 450 or more, from the viewpoint of improving compatibility with each component in the urethane coating composition, and the abrasion resistance of the cured coating film From a viewpoint of improving, it is preferable that it is 1500 or less, and it is more preferable that it is 1000 or less. The number of hydroxyl groups per molecule of the polyether polyol (b) is preferably 3 or more from the viewpoint of improving the scratch resistance of the cured coating film, and 6 from the viewpoint of improving compatibility with each component in the urethane coating composition, It is preferable that it is below.

Below, the compounding quantity of each component of the urethane coating composition of this invention is demonstrated. In addition, hereafter, the said polyisocyanate (a) is also called (a) component, and it calls similarly also about other components (for example, (b)) other than (a).

The said (a) component is 35 weight% or more and 85 weight% or less in the total weight of the said (a)-(c) component. The component (a) is preferably 40 wt% or more, more preferably 50 wt% or more, from the viewpoint of improving the scratch resistance of the cured coating film in the total weight of the components (a) to (c). And from a viewpoint of improving the softness|flexibility of a cured coating film, it is preferable that it is 75 weight% or less, and it is more preferable that it is 70 weight% or less.

The said (b-1) component is 3 weight% or more and 18 weight% or less in the total weight of the said (a)-(c) component. The component (b-1) is preferably 5 wt% or more, more preferably 7 wt% or more, from the viewpoint of improving the scratch resistance of the cured coating film in the total weight of the components (a) to (c). And from a viewpoint of improving antifogging property after wiping, it is preferable that it is 15 weight% or less, and it is more preferable that it is 12 weight% or less.

The said (b-2) component is 8 weight% or more and 38 weight% or less in the total weight of the said (a)-(c) component. From the viewpoint of improving the scratch resistance of the cured coating film, the component (b-2) is preferably 10% by weight or more, more preferably 15% by weight or more, based on the total weight of the components (a) to (c). And from a viewpoint of improving antifogging property after wiping, it is preferable that it is 35 weight% or less, and it is more preferable that it is 30 weight% or less.

The said (b-3) component is 0.5 weight% or more and 8 weight% or less in the total weight of the said (a)-(c) component. The component (b-3) is preferably 1% by weight or more, more preferably 1.5% by weight or more, from the viewpoint of improving the antifogging property after water resistance in the total weight of the components (a) to (c). And, from a viewpoint of improving antifogging property after wiping, it is preferable that it is 5 weight% or less, and it is more preferable that it is 3 weight% or less.

The component (a) and the component (b) have an equivalent ratio of the isocyanate group of the component (a) / the hydroxyl group of the component (b) is preferably blended in 0.4 or more and 2 or less, and blended in 0.5 or more and 1.7 or less more preferably.

In the total weight of the components (a) to (c), the component (c) is an ionic surfactant having a hydroxyl group in the molecule and an anionic surfactant and/or an amphoteric that does not have a reactive group with an isocyanate group. The total weight of surfactant is 1.0 weight% or more and 10 weight% or less. The component (c) is preferably 2% by weight or more, more preferably 3% by weight or more, from the viewpoint of improving the antifogging property of the cured coating film in the total weight of the components (a) to (c), And it is preferable that it is 8 weight% or less from a viewpoint of improving compatibility with each component in a urethane coating composition, and a viewpoint of providing transparency to a cured coating film.

In the component (c), the weight ratio of the anionic surfactant and/or amphoteric surfactant that does not have a reactive group with an isocyanate group to the ionic surfactant having a hydroxyl group in the molecule is preferably 0.1 or more, and 1.0 It is more preferable that it is more than that, and it is preferable that it is 5.0 or less, and it is more preferable that it is 4.0 or less.

In addition, when the urethane coating composition contains the component (d), the component (d) is 0.05 from the viewpoint of increasing the smoothness of the cured coating film in the total weight of the components (a) to (d). It is preferably at least 0.1 wt%, more preferably at least 0.1 wt%, and from the viewpoint of improving compatibility with each component in the urethane coating composition and improving the antifogging property of the cured coating film, it is preferably 3 wt% or less, , more preferably 2 wt% or less, and still more preferably 1 wt% or less.

In addition, when the component (e) is included in the urethane coating composition, the component (e) is compatible with each component in the urethane coating composition in the total weight of the components (a) to (e). It is preferable that it is 10 weight% or less, and it is more preferable that it is 5 weight% or less from a viewpoint of raising , and a viewpoint of improving the antifogging property of a cured coating film. Moreover, in the total weight of the said (a)-(e) component, the said (e) component can expect the improvement of the abrasion resistance of a cured coating film as it is 0.5 weight% or more.

When the component (e) is included in the urethane coating composition, the component (a), the component (b) and the component (e) include the isocyanate group/{(b) component of the component (a) and ( It is preferable to mix|blend in 0.2 or more and 4 or less, and, as for the equivalence ratio of the sum total hydroxyl group of e) component}, it is more preferable to mix|blend in 0.3 or more and 2.5 or less.

The urethane coating composition of the present invention can be prepared by diluting it with an organic solvent.

As said organic solvent, the solvent of alcohol type, a carboxylate type, a ketone type, an amide type, an ether type, an aliphatic type, and an aromatic hydrocarbon type is mentioned, for example. Examples of the alcohol-based solvent include methanol, isopropyl alcohol, n-butanol, diacetone alcohol, 2-methoxyethanol (methyl cellosolve), 2-ethoxyethanol (ethyl cellosolve), 2- Butoxyethanol (butyl cellosolve), tertiaryamyl alcohol, etc. are mentioned. Examples of the carboxylate solvent include ethyl acetate, n-propyl acetate, butyl acetate, and butyl formate. Examples of the ketone solvent include methyl ethyl ketone, methyl isobutyl ketone, acetone, and cyclohexanone. Examples of the amide solvent include dimethylformamide and dimethylacetamide. Examples of the ether solvent include diethyl ether, methoxytoluene, 1,2-dimethoxyethane, 1,2-dibutoxyethane, 1,1-dimethoxymethane, 1,1-dimethoxyethane, 1,4-dioxane, tetrahydrofuran, etc. are mentioned. As an aliphatic and aromatic hydrocarbon type solvent, hexane, pentaxylene, toluene, benzene etc. are mentioned, for example. The said organic solvent may be used individually, respectively, and may mix and use 2 or more types. As for the said organic solvent, the solvent which mixed polar solvents, such as diacetone alcohol and tertiary-amyl alcohol, and a carboxylate ester and/or a ketone solvent is preferable from a viewpoint of solubility, volatility, and adhesiveness.

The isocyanate group of the polyisocyanate (a) reacts with the hydroxyl group of the polyether polyol (b) and the hydroxyl group of the polycaprolactone polyol (e) to form a urethane bond. A well-known catalyst can be added to reaction which forms a urethane bond as needed. Known catalysts include, for example, triethylamine, tetra(2-ethylhexyl)titanate, di-n-butyltin dilaurylate, and 1,4-diazabicyclo[2.2.2]octane. have. When using these catalysts, the usage-amount is 0.001-10 weight part normally with respect to 100 weight part of said polyisocyanate (a). The said catalyst may be used individually, respectively, and may mix and use 2 or more types.

In the urethane coating composition of the present invention, if necessary, stabilizers such as ultraviolet absorbers, antioxidants, light stabilizers, colorants, flame retardants, isocyanate compounds other than the polyisocyanate (a), the polyether polyol (b) and polycaprolactone Although polyols other than polyol (e) and leveling agents other than the said silicone oil (d) can be used, it is preferable that it is 0.1-10 weight part with respect to a total of 100 weight part of said (a)-(c) components.

<Cured coating film>

The urethane coating composition of this invention can form a cured coating film on the surface of a base material by coating on a base material by the coating method performed in a normal paint, and heat-hardening.

As said base material, the kind is not questioned, and a well-known resin base material (member) can be used. As said resin base material (member), For example, polymethyl methacrylate resin, polycarbonate resin, polystyrene resin, acrylonitrile-styrene copolymer resin, polyvinyl chloride resin, acetate resin, ABS resin, polyester resin, poly Amide resin etc. are mentioned.

The method for coating the urethane coating composition of the present invention on the resin substrate (member) is not particularly limited, and known methods such as bar coater coating, brush coating, flow coating, dip coating, spray coating, spin coating, flow coating and the like are known. method can be employed.

The temperature at which the urethane coating composition of the present invention is heat-cured is preferably 60°C or more and 150°C or less, more preferably 80°C or more and 130°C or less, but may be appropriately adjusted according to the heat resistance or heat deformability of the base resin to be used. The heating time varies depending on the heating temperature, but is on the order of several minutes to several hours.

From a viewpoint of improving the antifogging property of a cured coating film, 1.0 micrometer or more is preferable, and, as for the film thickness of the said cured coating film, 3.0 micrometers or more are more preferable. From a viewpoint of improving the smoothness of a cured coating film, 30 micrometers or less are preferable and, as for the film thickness of the said cured coating film, 20 micrometers or less are more preferable.

Example

The present invention will be described below by way of Examples and the like, but the present invention is not limited thereto.

The raw materials used by each Example and the comparative example are as follows.

<Raw material>

<Polyisocyanate (a)>

a-1: 1,6-hexamethylene diisocyanate derivative and block polyisocyanate compound of dimethyl malonate/3,5-dimethylpyrazole (solid content 70 wt%, propylene glycol monomethyl ether 30 wt%, vs. Solution isocyanate group content 9.2%, manufactured by BAXENDEN, TRIXENE BI7992)

a-2: a derivative of isophorone diisocyanate and a block polyisocyanate compound of 3,5-dimethylpyrazole (solid content 65% by weight, butyl acetate 12.5% by weight, C9 aromatic 12.5% by weight, substitute solution isocyanate group content 7.8%, BAXENDEN Manufactured by TRIXENE BI7951)

<Polyether polyol (b)>

b-1: polyoxyethylene glyceryl ether (solid content 100%, number of hydroxyl groups per molecule 3, number average molecular weight 450, manufactured by Nichiyu Corporation, Uniox G450)

b-2: polyoxyethylene glyceryl ether (solid content 100%, number of hydroxyl groups per molecule 3, number average molecular weight 750, manufactured by Nichiyu Corporation, Uniox G750)

b-3: polyoxypropylene glyceryl ether (solid content 100%, number of hydroxyl groups per molecule 3, number average molecular weight 1500, manufactured by Sanyo Chemical Industries, Ltd., Sunnics GP1500)

<Surfactant (c)>

c-1: Ricinolamide propylethyldimonium ethosulphate (solid content 100%, VANTAGE Specialty Ingredient, Inc., Lipoquat R)

c-2: sodium di-2-ethylhexyl sulfosuccinate

c-3: Anionic fluorine-based surfactant (solid content 100%, sodium sulfonate salt, manufactured by Neos Co., Ltd., Ftergent 100)

c-4: amphoteric fluorine-based surfactant (solid content 50%, Neos Co., Ltd., Ftergent 400SW)

<Silicone oil (d)>

d-1: polyether-modified organopolysiloxane (HLB value = 12, KF-642 manufactured by Shin-Etsu Chemical Industry Co., Ltd.)

d-2: polyether-modified organopolysiloxane (HLB value = 14, KF-640 manufactured by Shin-Etsu Chemical Industry Co., Ltd.)

<Polycaprolactone polyol (e)>

e-1: polycaprolactone triol (solid content 100%, number of hydroxyl groups per molecule 3, number average molecular weight 800, Daicel Co., Ltd., Placel 308)

<Other ingredients>

b'-1: polyethylene glycol (solid content 100%, number of hydroxyl groups per molecule 2, number average molecular weight 200, Tokyo Chemical Industry Co., Ltd. make, PEG200)

b'-2: polyethylene glycol (solid content 100%, number of hydroxyl groups per molecule 2, number average molecular weight 2000, Tokyo Chemical Industry Co., Ltd. make, PEG2000)

c'-1: nonionic fluorine-based surfactant (solid content 100%, manufactured by Neos Co., Ltd., Ftergent 215M)

c'-2: cationic fluorine-based surfactant (solid content 100%, quaternary ammonium salt (I salt or Br salt), manufactured by Neos Co., Ltd., Ftergent 300)

<Organic solvent>

Diacetone Alcohol (DAA)

<Preparation of urethane coating composition>

<Examples 1 to 10, Comparative Examples 1 to 13>

The above raw materials were blended in the proportions shown in Tables 1 and 2, and 0.5 parts by weight of di-n-butyltin dilauryl acid was added to 100 parts by weight of polyisocyanate as a catalyst, respectively, and the urethanes of Examples and Comparative Examples. A coating composition was obtained.

Each of the urethane coating compositions obtained above was coated on a polycarbonate resin plate (7.5 cm × 10 cm × 2 mm, Mitsubishi Gas Chemical Co., Ltd. Upiron) using a bar coater so that the cured film thickness was about 8 μm. It carried out and thermosetted for 30 minutes in the oven set to 120 degreeC, and the resin base material (member) which has a cured coating film was obtained. Evaluation was performed by the following test method. A result is shown in Table 1 and Table 2.

<Evaluation of appearance>

The surface of the cured coating film was visually judged and evaluated by the following evaluation criteria.

○ : Normal

x: Abnormalities, such as opacity, whitening, or not smooth

<Evaluation of scratch resistance>

Steel wool (#0000) loaded with a load of 500 g is placed on the surface of the cured coating film, tested under the test conditions of 11 reciprocating with a rubbing tester, and cured after the test with a haze meter (NDH5000 manufactured by Nippon Denshoku Industries Co., Ltd.) The haze (%) of the resin member which has a coating film was measured, and the following evaluation criteria evaluated it.

○: The value of the haze after the test is less than 10

x: the value of the haze after the test is 10 or more

<Evaluation of adhesion>

After cross-cutting the cured coating film to 10 × 10 mesh (1 mm interval), a cellophane tape peel test was performed to visually confirm the remaining mesh.

○: No peeling

×: with peeling

<Evaluation of initial anti-fogging properties>

In a constant temperature room at 25°C, the surface of the cured coating film was exposed to hot water steam at 50°C for 1 minute, and the following evaluation criteria evaluated the presence or absence of cloudiness visually.

◎: Quickly forms a water film

○: Forms a water film after cloudiness for one moment

×: Blurring occurs

<Evaluation of anti-fogging properties after waterproofing>

After the resin substrate having a cured coating film was immersed in distilled water at room temperature for 1 hour, it was taken out and left at room temperature for 1 hour. Then, the said initial stage antifogging property evaluation test was implemented, and the presence or absence of fogging was confirmed.

◎: Quickly forms a water film

○: Forms a water film after cloudiness for one moment

×: Blurring occurs

<Evaluation of anti-fogging properties after wiping>

A waste (BEMCOT M-3II, 250 mm x 250 mm, manufactured by Ozu Industrial Co., Ltd.) impregnated with about 5 ml of distilled water is placed on the surface of the cured coating film and reciprocated three times. Moreover, after leaving this resin base material (member) which has this cured coating film in the room of 25 degreeC 50 %RH for 1 hour, the surface of the cured coating film was exposed to 50 degreeC hot water steam in 25 degreeC constant temperature room for 5 minutes. After repeating the said operation 5 times, the following evaluation criteria evaluated the presence or absence of cloudiness visually. When the surfactant exists only on the surface of the cured coating film, the surfactant tends to be wiped off with a waste and cloudiness tends to occur.

(double-circle) : Water film was formed rapidly in the evaluation of the 5th time.

○: Forms a water film after cloudiness for one moment in the fifth evaluation

x: Cloudiness occurred in the evaluation of the 5th time

Claims (5)

A urethane coating composition comprising a polyisocyanate (a), a polyether polyol (b), and a surfactant (c), comprising:
The polyisocyanate (a) is a blocked polyisocyanate compound obtained by reacting at least one polyisocyanate compound selected from the group consisting of diisocyanate and derivatives thereof with a thermally dissociable blocking agent,
The polyether polyol (b) includes a polyether polyol (b-1) having a number average molecular weight of 300 or more and less than 600, a polyether polyol (b-2) having a number average molecular weight of 600 or more and less than 900, and a number average molecular weight of 900 It is a polyether polyol (b-3) of 1800 or more,
The surfactant (c) is an ionic surfactant having a hydroxyl group in the molecule and an anionic surfactant and/or amphoteric surfactant that does not have a reactive group with an isocyanate group,
In the total weight of the components (a) to (c), the component (a) is 35 wt% or more and 85 wt% or less, and the (b-1) component is 3 wt% or more and 18 wt% or less, (b-2) component is 8 wt% or more and 38 wt% or less, (b-3) component is 0.5 wt% or more and 8 wt% or less, and (c) component is 1 wt% or more and 10 wt% or less A urethane paint composition characterized in that. The method of claim 1,
silicone oil (d) having an HLB of 10 to 18;
A urethane coating composition characterized in that, in the total weight of the components (a) to (d), the component (d) is 3% by weight or less. 3. The method of claim 2,
polycaprolactone polyol (e);
The polycaprolactone polyol (e) has a number average molecular weight of 300 or more and 1800 or less,
A urethane coating composition characterized in that, in the total weight of the components (a) to (e), the component (e) is 10% by weight or less. A cured coating film formed from the urethane coating composition according to any one of claims 1 to 3. It has the cured coating film of Claim 4, The resin member characterized by the above-mentioned.