JP2011208050A - Water-dispersion type blocked isocyanate composition and polyurethane resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-dispersion type blocked isocyanate composition which is excellent in emulsion stability and storage stability and can provide a polyurethane resin excellent in water resistance, appearance and transparency, and to provide a polyurethane resin obtained by using the water-dispersion type blocked isocyanate composition.SOLUTION: The water-dispersion type blocked isocyanate composition contains: a blocked isocyanate having isocyanate groups blocked by a blocking agent; and a dispersant, wherein the dispersant does not contain a protective colloid agent and contains an aromatic nonion surface active agent which has a hydroxy group on a molecular terminal and has an HLB of 16 or more. Further, the polyurethane resin is obtained by allowing an isocyanate component comprising the water-dispersion type blocked isocyanate composition to react with a polyol component.

Description

  The present invention relates to a water-dispersed blocked isocyanate composition and a polyurethane resin, and particularly relates to a water-dispersed blocked isocyanate composition used as a curing agent and a polyurethane resin obtained using the water-dispersed blocked isocyanate composition. .

  Block isocyanate is isocyanate that dissociates upon heating and the isocyanate group is regenerated, and has a long pot life and excellent processability. Therefore, polyol components (main agent) and isocyanate components (curing agents) such as paints and adhesives are used. Is often used as a curing agent for a two-component curable polyurethane resin to be blended at the time of use.

  Such a blocked isocyanate is conventionally prepared by dissolving in an organic solvent. However, in recent years, it has been desired to reduce the use of the organic solvent from the viewpoint of environmental load, and it is prepared by dispersing in water. Various studies have been conducted.

  In addition, as blocking agents for blocked isocyanates, for example, oxime compounds, caprolactam compounds, pyrazole compounds, etc. are known, but pyrazole compounds dissociate at a lower temperature than oxime compounds and caprolactam compounds, so low temperature curing is required. It is used as a blocking agent.

  As such a blocked isocyanate, for example, after reacting 1,6-hexamethylene diisocyanate trimer and polyoxyethyleneamine, further reacted with 3,5-dimethylpyrazole (blocking agent), A water-dispersible blocked isocyanate obtained by adding butyl glycol ether, sodium sulfosuccinate (ionic surfactant) and water has been proposed (see, for example, Patent Document 1).

  In the molecular structure of such water-dispersible blocked isocyanate, at least three ethylene oxide groups that are continuous with the blocked isocyanate are introduced, and the blocked isocyanate is internally emulsified.

  Other blocked isocyanates include, for example, block isocyanates in which the isocyanate groups of hexamethylene diisocyanate polyisocyanate containing an isocyanurate structure in the molecule are completely blocked, nonionic surfactants and protective colloid agents. A water-dispersible auxiliary agent and a block isocyanate aqueous dispersion mainly composed of water as a medium have also been proposed (see, for example, Patent Document 2).

Japanese National Patent Publication No. 11-512772 JP-A-4-216817

  However, in the water-dispersed blocked isocyanate described in Patent Document 1, a polyoxyethylene group is introduced into the molecular structure by the reaction of 1,6-hexamethylene diisocyanate trimer and polyoxyethylene amine.

  That is, in this water-dispersed blocked isocyanate, the isocyanate group of 1,6-hexamethylene diisocyanate trimer is consumed in order to introduce a polyoxyethylene group.

  Therefore, with such a water-dispersed blocked isocyanate, a sufficient isocyanate group concentration cannot be ensured, and a large amount of water-dispersed blocked isocyanate is required in blending with the polyol component. Furthermore, the polyurethane resin obtained by the reaction of such a water-dispersed blocked isocyanate and a polyol component may not be able to ensure excellent water resistance.

  Moreover, the block isocyanate aqueous dispersion described in Patent Document 2 contains a protective colloid (more specifically, polyvinyl alcohol or the like) as an essential component.

  A block isocyanate aqueous dispersion containing such a protective colloid may be inferior in emulsion stability or storage stability.

  Moreover, the polyurethane resin obtained by the reaction of such a block isocyanate aqueous dispersion and a polyol component still cannot sufficiently secure water resistance, and further, obtains excellent appearance and transparency. There is a bug that cannot be done.

  An object of the present invention is to provide a water-dispersed blocked isocyanate composition capable of obtaining a polyurethane resin having excellent emulsification stability and storage stability, as well as excellent water resistance, appearance, and transparency, and the water-dispersed blocked isocyanate composition It is providing the polyurethane resin obtained using a thing.

  In order to achieve the above object, the water-dispersed blocked isocyanate composition of the present invention is a blocked isocyanate in which an isocyanate group is blocked by a blocking agent, and a water-dispersed blocked isocyanate composition containing a dispersing agent, The dispersant does not contain a protective colloid agent but contains a surfactant, and the surfactant contains an HLB16 or higher aromatic nonionic surfactant having a hydroxyl group at the molecular end. Yes.

  In the water-dispersed blocked isocyanate composition of the present invention, it is preferable that the surfactant further contains an aromatic nonionic surfactant having a hydroxy group at the molecular terminal and less than HLB16.

  The water-dispersed blocked isocyanate composition of the present invention preferably contains 0.1 to 3 parts by mass of an anionic surfactant with respect to 100 parts by mass of the blocked isocyanate.

  In the water-dispersed blocked isocyanate composition of the present invention, it is preferable that the volume average particle diameter of the blocked isocyanate is 300 nm or less.

  The polyurethane resin of the present invention is characterized by being obtained by a reaction between an isocyanate component composed of the water-dispersed blocked isocyanate composition and a polyol component.

  The water-dispersed blocked isocyanate composition of the present invention can ensure excellent emulsification stability and storage stability.

  Moreover, according to the water-dispersed blocked isocyanate composition of the present invention, a polyurethane resin having excellent water resistance, appearance, and transparency can be obtained.

  Moreover, since the above-mentioned water-dispersed blocked isocyanate composition is used, the polyurethane resin of the present invention can have excellent water resistance, appearance, and transparency.

  The water-dispersed blocked isocyanate composition of the present invention contains a blocked isocyanate and a dispersant.

  The blocked isocyanate is an isocyanate compound in which an isocyanate group is blocked by a blocking agent, and is not particularly limited. However, as a raw material component, an isocyanate compound containing at least two isocyanate groups in one molecule and a blocking agent are used. Contains.

  Examples of the isocyanate compound include polyisocyanates such as aromatic polyisocyanates, araliphatic polyisocyanates, alicyclic polyisocyanates, and aliphatic polyisocyanates.

  Examples of the aromatic polyisocyanate include tolylene diisocyanate (2,4- or 2,6-tolylene diisocyanate or a mixture thereof) (hereinafter, abbreviated as TDI), phenylene diisocyanate (m-, p-phenylene diisocyanate or a mixture thereof). Mixture), 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate (hereinafter abbreviated as NDI), diphenylmethane diisocyanate (4,4'-, 2,4'- or 2,2'-diphenylmethane dii Succinate or a mixture thereof (hereinafter abbreviated as MDI), 4,4'-toluidine diisocyanate (hereinafter abbreviated as TODI), aromatic diisocyanates such as 4,4'-diphenyl ether diisocyanate, and the like.

  Examples of the araliphatic polyisocyanate include xylylene diisocyanate (1,3- or 1,4-xylylene diisocyanate or a mixture thereof) (hereinafter abbreviated as XDI), tetramethylxylylene diisocyanate (1,3- or 1,4-tetramethylxylylene diisocyanate or a mixture thereof (hereinafter abbreviated as TMXDI), and araliphatic diisocyanates such as ω, ω′-diisocyanate-1,4-diethylbenzene.

Examples of the alicyclic polyisocyanate include 1,3-cyclopentane diisocyanate, 1,3-cyclopentene diisocyanate, cyclohexane diisocyanate (1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate), and 3-isocyanatomethyl-3. , 5,5-trimethylcyclohexyl isocyanate (isophorodiisocyanate, hereinafter abbreviated as IPDI), methylene bis (cyclohexyl isocyanate) (4,4'-, 2,4'- or 2,2'-methylene bis (cyclohexyl isocyanate, these of Trans, Trans- body, Trans, Cis body, Cis, Cis body, or mixtures thereof)) _(hereinafter abbreviated as H 12 MDI), methylcyclohexane diisocyanate Natick (Methyl-2,4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate), norbornane diisocyanate (various isomers or mixtures thereof) (hereinafter abbreviated as NBDI), bis (isocyanatomethyl) cyclohexane (1,3 -Or 1,4-bis (isocyanatomethyl) cyclohexane or a mixture thereof (hereinafter abbreviated as H ₆ XDI).

  Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, 1,2-propylene diisocyanate, butylene diisocyanate (tetramethylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate), penta Examples include aliphatic diisocyanates such as methylene diisocyanate, hexamethylene diisocyanate (hereinafter abbreviated as HDI), 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, and 2,6-diisocyanate methyl capate. .

  Examples of the isocyanate compound also include derivatives of the above-described polyisocyanates (aromatic polyisocyanates, araliphatic polyisocyanates, alicyclic polyisocyanates, aliphatic polyisocyanates, etc.).

  Examples of the polyisocyanate derivative include, for example, the above-described polyisocyanate multimers (for example, dimers, trimers, pentamers, and 7-mers) and allophanate-modified products (for example, the above polyisocyanates and alcohols). Allophanate modified products produced by reaction with alcohols, polyol modified products (for example, polyol modified products produced by reaction of polyisocyanates with alcohols, etc.), biuret modified products (for example, poly Modified biuret produced by reaction of isocyanate with water or amines), modified urea (for example, modified urea produced by reaction of polyisocyanate and diamine described above), modified oxadiazine trione ( For example, in the reaction of the above polyisocyanate and carbon dioxide gas Oxadiazinetrione, etc.) to produce Ri, carbodiimide modified product (carbodiimide modified product produced by decarboxylation condensation reaction of the polyisocyanate described above, etc.), uretdione modified product, like uretonimine modified product.

  These isocyanate compounds can be used alone or in combination of two or more.

  Preferred isocyanate compounds include araliphatic polyisocyanates and / or derivatives thereof, more preferably xylylene diisocyanate (1,3- or 1,4-xylylene diisocyanate or mixtures thereof (XDI)) and / or Or a derivative thereof.

  The blocking agent is not particularly limited as long as it is a blocking agent that is dissociated from an isocyanate compound by heat treatment. For example, an alcohol compound, a phenol compound, an active methylene compound, an amine compound, an imine compound, and an oxime compound. Carbamic acid compounds, urea compounds, acid amide (lactam) compounds, acid imide compounds, triazole compounds, pyrazole compounds, imidazole compounds, imidazoline compounds, mercaptan compounds, bisulfites, and the like. It is done.

  Examples of the alcohol compound include methanol, ethanol, 2-propanol, n-butanol, s-butanol, 2-ethylhexyl alcohol, 1- or 2-octanol, cyclohexyl alcohol, ethylene glycol, benzyl alcohol, 2,2 , 2-trifluoroethanol, 2,2,2-trichloroethanol, 2- (hydroxymethyl) furan, 2-methoxyethanol, methoxypropanol, 2-ethoxyethanol, n-propoxyethanol, 2-butoxyethanol, 2-ethoxy Ethoxyethanol, 2-ethoxybutoxyethanol, butoxyethoxyethanol, 2-ethylhexyloxyethanol, 2-butoxyethylethanol, 2-butoxyethoxyethanol, N, N-dibutyl-2 Hydroxyacetamide, N-hydroxysuccinimide, N-morpholine ethanol, 2,2-dimethyl-1,3-dioxolane-4-methanol, 3-oxazolidineethanol, 2-hydroxymethylpyridine, furfuryl alcohol, 12-hydroxystearic acid, Examples include triphenylsilanol and 2-hydroxyethyl methacrylate.

  Examples of phenolic compounds include phenol, cresol, ethylphenol, n-propylphenol, isopropylphenol, n-butylphenol, s-butylphenol, t-butylphenol, n-hexylphenol, 2-ethylhexylphenol, n-octylphenol, n -Nonylphenol, di-n-propylphenol, diisopropylphenol, isopropylcresol, di-n-butylphenol, di-s-butylphenol, di-t-butylphenol, di-n-octylphenol, di-2-ethylhexylphenol, di-n -Nonylphenol, nitrophenol, bromophenol, chlorophenol, fluorophenol, dimethylphenol, styrenated phenol, methyl salicyla , Methyl 4-hydroxybenzoate, benzyl 4-hydroxybenzoate, 2-ethylhexyl hydroxybenzoate, 4-[(dimethylamino) methyl] phenol, 4-[(dimethylamino) methyl] nonylphenol, bis (4-hydroxy Phenyl) acetic acid, pyridinol, 2- or 8-hydroxyquinoline, 2-chloro-3-pyridinol, pyridine-2-thiol and the like.

  Examples of the active methylene compound include Meldrum's acid, dialkyl malonate (for example, dimethyl malonate, diethyl malonate, di-n-butyl malonate, di-t-butyl malonate, di-2-ethylhexyl malonate, malonic acid. Methyl n-butyl, ethyl n-butyl malonate, methyl s-butyl malonate, ethyl s-butyl malonate, methyl t-butyl malonate, ethyl t-butyl malonate, diethyl methylmalonate, dibenzyl malonate, malon Diphenyl acid, benzyl methyl malonate, ethyl phenyl malonate, t-butylphenyl malonate, isopropylidene malonate, etc.), alkyl acetoacetate (eg methyl acetoacetate, ethyl acetoacetate, n-propyl acetoacetate, isopropyl acetoacetate) , N-butyl acetoacetate, acetoacetic acid - butyl acetoacetate benzyl, phenyl acetoacetate, etc.), 2-acetoacetoxyethyl methacrylate, acetylacetone, and the like such as ethyl cyanoacetate.

  Examples of the amine compound include dibutylamine, diphenylamine, aniline, N-methylaniline, carbazole, bis (2,2,6,6-tetramethylpiperidinyl) amine, di-n-propylamine, diisopropylamine, Isopropylethylamine, 2,2,4- or 2,2,5-trimethylhexamethyleneamine, N-isopropylcyclohexylamine, dicyclohexylamine, bis (3,5,5-trimethylcyclohexyl) amine, piperidine, 2,6 -Dimethylpiperidine, 2,2,6,6-tetramethylpiperidine, (dimethylamino) -2,2,6,6-tetramethylpiperidine, 2,2,6,6-tetramethyl-4-piperidine, 6- Examples include methyl-2-piperidine, 6-aminocaproic acid, etc. It is.

  Examples of the imine compound include ethyleneimine, polyethyleneimine, 1,4,5,6-tetrahydropyrimidine, guanidine and the like.

  Examples of oxime compounds include formaldehyde oxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, cyclohexanone oxime, diacetyl monooxime, benzophenoxime, 2,2,6,6-tetramethylcyclohexanone oxime, diisopropyl ketone oxime. , Methyl t-butyl ketone oxime, diisobutyl ketone oxime, methyl isobutyl ketone oxime, methyl isopropyl ketone oxime, methyl 2,4-dimethylpentyl ketone oxime, methyl 3-ethyl heptyl ketone oxime, methyl isoamyl ketone oxime, n-amyl ketone Oxime, 2,2,4,4-tetramethyl-1,3-cyclobutanedione monooxime, 4,4′-dimethoxybenzophenone oxime, 2-he Tanon'okishimu and the like.

  Examples of the carbamic acid compound include phenyl N-phenylcarbamate.

  Examples of the urea compound include urea, thiourea, and ethylene urea.

  Examples of acid amide (lactam) compounds include acetanilide, N-methylacetamide, acetic acid amide, ε-caprolactam, δ-valerolactam, γ-butyrolactam, pyrrolidone, 2,5-piperazinedione, laurolactam, and the like. It is done.

  Examples of the acid imide compound include succinimide, maleic imide, phthalimide, and the like.

  Examples of triazole compounds include 1,2,4-triazole and benzotriazole.

  Examples of the pyrazole compound include pyrazole, 3,5-dimethylpyrazole, 3-methylpyrazole, 4-benzyl-3,5-dimethylpyrazole, 4-nitro-3,5-dimethylpyrazole, 4-bromo-3, Examples include 5-dimethylpyrazole and 3-methyl-5-phenylpyrazole.

  Examples of the imidazole compound include imidazole, benzimidazole, 2-methylimidazole, 4-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, 2,4-dimethylimidazole, 2-ethyl-4-methylimidazole, 2 -Phenylimidazole, 4-methyl-2-phenylimidazole and the like.

  Examples of the imidazoline-based compound include 2-methylimidazoline and 2-phenylimidazoline.

  Examples of mercaptan compounds include butyl mercaptan, dodecyl mercaptan, hexyl mercaptan, and the like.

  Examples of the bisulfite include sodium bisulfite.

  Moreover, as a blocking agent, it is not limited to the above, For example, other blocking agents, such as a benzoxazolone, an isatoic anhydride, tetrabutylphosphonium acetate, are mentioned.

  These blocking agents can be used alone or in combination of two or more.

  As a blocking agent, Preferably, an oxime type compound and a pyrazole type compound, More preferably, a pyrazole type compound is mentioned.

  When an oxime compound or a pyrazole compound is used as the blocking agent, excellent low temperature dissociation properties can be ensured, and emulsion stability and storage stability can be improved.

  The blocked isocyanate can be obtained, for example, by reacting an isocyanate compound with a blocking agent.

  More specifically, for example, the equivalent ratio (active group / isocyanate group) of an active group that reacts an isocyanate compound and a blocking agent with an isocyanate group in the blocking agent with respect to an isocyanate group of the isocyanate compound is 0.8 or more. The reaction is preferably carried out at a blending ratio of 1.0 or more, usually 1.2 or less.

  More specifically, the blending ratio of the isocyanate compound and the blocking agent is, for example, 10 to 200 parts by mass, preferably 20 to 80 parts by mass with respect to 100 parts by mass of the isocyanate compound. is there.

  In such a reaction, if necessary, a reaction solvent can be used. Such a reaction solvent is a low-boiling solvent that is inert to an isocyanate group and easily removed, for example, ethyl acetate. And organic solvents such as esters such as butyl acetate, ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran, and nitriles such as acetonitrile, and the like. The mixing ratio of the reaction solvent is not particularly limited, and is appropriately determined according to the purpose and application.

  As reaction conditions, for example, the reaction temperature is, for example, 0 to 150 ° C., preferably 20 to 120 ° C. in an atmosphere of an inert gas (eg, nitrogen gas, argon gas) under atmospheric pressure. The reaction time is, for example, 5 minutes to 12 hours, preferably 5 minutes to 8 hours.

  In addition, completion | finish of reaction can be judged by employ | adopting infrared spectroscopy etc. and confirming the loss | disappearance of an isocyanate group, for example.

  And thereby, the blocked isocyanate in which the isocyanate group of the isocyanate compound was blocked by the blocking agent can be prepared.

  The dispersant is blended to disperse (emulsify) the blocked isocyanate in water, and the dispersant usually includes a protective colloid agent and a surfactant, but the water-dispersed blocked isocyanate of the present invention. In the composition, the dispersant does not contain a protective colloid agent but contains a surfactant. More specifically, the dispersant contains only a surfactant.

  Examples of protective colloid agents include fully saponified polyvinyl alcohol, partially saponified polyvinyl alcohol, block partially saponified polyvinyl alcohol, polyvinyl pyrrolidone, methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, methylhydroxycellulose, carboxymethylcellulose, gelatin, starch paste, Examples include acrylic acid polymers and methacrylic acid polymers.

  The surfactant contains an HLB16 or higher aromatic nonionic surfactant having a hydroxy group at the molecular end as an essential component.

  Examples of the aromatic nonionic surfactant having a hydroxy group at the molecular end include polyoxyethylene alkylphenyl ethers such as polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene dibutyl phenyl ether, and the like. Examples include polyoxyethylene arylphenyl ethers such as oxyethylene styryl phenyl ether (polyoxyethylene styrenated phenyl ether, polyoxyethylene distyrenated phenyl ether, etc.), polyoxyethylene benzyl phenyl ether, polyoxyethylene cumyl phenyl ether, etc. It is done.

  These aromatic nonionic surfactants can be used alone or in combination of two or more.

  As an aromatic nonionic surfactant, Preferably, polyoxyethylene arylphenyl ether is mentioned, More preferably, polyoxyethylene styryl phenyl ether and polyoxyethylene cumyl phenyl ether are mentioned.

  Moreover, as above-mentioned, HLB of the aromatic nonionic surfactant as an essential component is 16 or more, Preferably, it is 18 or more, and is 20 or less normally.

  Such an HLB16 or higher aromatic nonionic surfactant is also available as a commercial product. Specifically, for example, Emulgen A-500 (polyoxyethylene distyrenated phenyl ether solid content concentration: 100% by mass) , HLB: 18.0, manufactured by Kao Corporation), CP-20 (polyoxyethylene cumylphenyl ether, solid content concentration: 100% by mass, HLB: 16.3, manufactured by Toho Chemical Industry Co., Ltd.), Neugen EA177 (polyoxy) And ethylene styryl phenyl ether, solid content concentration: 100 mass%, HLB: 17.0, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

  The blending ratio of the HLB16 or more aromatic nonionic surfactant having a hydroxy group at the molecular end is, for example, 1 to 30 parts by mass, preferably 3 to 20 parts by mass, more preferably 100 parts by mass of the blocked isocyanate. Is 5 to 15 parts by mass.

  The surfactant preferably contains, as an optional component, an aromatic nonionic surfactant having a hydroxy group at the molecular terminal and less than HLB16.

  If an aromatic nonionic surfactant having a hydroxyl group at the molecular terminal and less than HLB16 is blended, the emulsion stability and storage stability can be improved, and the water resistance can be improved.

  Examples of the aromatic nonionic surfactant include the above-described aromatic nonionic surfactant.

  Further, as described above, the HLB of the aromatic nonionic surfactant as an optional component is less than 16, preferably less than 15, and is usually 4 or more, preferably 8 or more.

  Such an aromatic nonionic surfactant having an HLB of less than 16 is also available as a commercial product. Specifically, for example, Nonal 912A (polyoxyethylene cumylphenyl ether, solid content concentration: 100% by mass, HLB : 14.3, manufactured by Toho Chemical Industry Co., Ltd.), Neugen EA87 (polyoxyethylene styryl phenyl ether, solid content concentration: 100% by mass, HLB: 10.6, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), and the like.

  When the surfactant contains, as an optional component, an aromatic nonionic surfactant having a hydroxy group at the molecular end and less than HLB16, the content ratio is the above-mentioned essential component (HLB16 having a hydroxy group at the molecular end). The above aromatic nonionic surfactant) is 100 parts by mass, for example, 1 to 150 parts by mass, preferably 10 to 120 parts by mass, more preferably 30 to 100 parts by mass, and the blocked isocyanate. It is 1-30 mass parts with respect to 100 mass parts, Preferably, it is 3-20 mass parts, More preferably, it is 5-15 mass parts.

  In addition, the surfactant is other optional component (optional component excluding the aromatic nonionic surfactant having a hydroxy group at the molecular end and less than HLB16), and other than the aromatic nonionic surfactant described above. Nonionic surfactants (hereinafter referred to as non-aromatic nonionic surfactants), anionic surfactants, cationic surfactants, amphoteric surfactants and the like can be contained.

  Non-aromatic nonionic surfactants include, for example, polyoxyethylene alkyl ether, polyoxyethylene hydrogenated castor oil, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, sucrose fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester, poly Examples thereof include oxyethylene glycerin fatty acid ester and polyoxyethylene glycol fatty acid ester.

  Examples of the anionic surfactant include fatty acid salts such as sodium laurate, sodium stearate, potassium stearate, sodium oleate, potassium oleate, and alkyl sulfate ester salts such as sodium lauryl sulfate, such as polyoxyethylene. Sulfate ester salts such as sodium alkyl ether sulfates (such as sodium polyoxyethylene lauryl ether sulfate), alkylbenzene sulfonates such as sodium alkylbenzene sulfonate (such as sodium dodecylbenzene sulfonate), such as dialkylsulfosuccinic acid Examples thereof include sulfonates such as sodium sulfosuccinate such as sodium.

  Examples of the cationic surfactant include quaternary ammonium salts such as lauryltrimethylammonium chloride.

  Examples of amphoteric surfactants include alkyl betaines such as lauryl betaine.

  As other optional components, preferably, an anionic surfactant is used.

  In the case where the surfactant contains other optional components (preferably anionic surfactant), the content ratio is the above-mentioned essential component (an aromatic nonionic surfactant of HLB16 or higher having a hydroxy group at the molecular end) ) 100 parts by weight, for example, 1-50 parts by weight, preferably 1-30 parts by weight, more preferably 3-20 parts by weight, and for 100 parts by weight of the blocked isocyanate, for example, 0.1 to 5 parts by mass, preferably 0.1 to 3 parts by mass, and more preferably 0.2 to 2 parts by mass.

  If an anionic surfactant is mix | blended as another arbitrary component and the mixture ratio is the said range, while ensuring the outstanding water resistance, storage stability can be improved.

  The blending ratio of the dispersant is, for example, 1 to 30 parts by mass, preferably 3 to 20 parts by mass, and more preferably 5 to 15 parts by mass with respect to 100 parts by mass of the blocked isocyanate.

  And in order to prepare the water-dispersed block isocyanate composition of this invention, block isocyanate is emulsified in water with a dispersing agent.

  Specifically, first, the above dispersant (surfactant) is dissolved in water to prepare a dispersant aqueous solution (surfactant aqueous solution), and the dispersant aqueous solution and the above-mentioned blocked isocyanate are mixed in the above proportions. It mix | blends so that it may become. In addition, when mix | blending the above-mentioned arbitrary component as surfactant, an arbitrary component can be suitably mix | blended with either or both of blocked isocyanate or dispersing agent aqueous solution.

  Next, for example, after stirring and mixing the blocked isocyanate and the aqueous dispersant solution using a stirrer such as a homomixer or a homodisper, water is further blended and emulsified as necessary to prepare a blocked isocyanate emulsion.

  In addition, additives, such as an antifoamer, can be added to a block isocyanate emulsion as needed. The blending ratio of the additive is not particularly limited, and is appropriately determined according to the purpose and application.

  Thereafter, when the blocked isocyanate emulsion contains an organic solvent (for example, when a reaction solution obtained by reacting an isocyanate compound and a blocking agent in an organic solvent is used as the blocked isocyanate as it is). The organic solvent is volatilized and removed by heating the block isocyanate emulsion under reduced pressure, for example.

  Thereby, the water-dispersed block isocyanate composition in which the blocked isocyanate is externally emulsified in water can be obtained.

  In the water-dispersed blocked isocyanate composition thus obtained, the volume average particle size of the blocked isocyanate is, for example, 450 nm or less, preferably 400 nm, more preferably 300 nm or less, more preferably 250 nm or less, usually , 50 nm or more.

  If the volume average particle diameter of the blocked isocyanate is not more than the above upper limit, the storage stability can be improved, and a coating film excellent in appearance can be obtained by blending with a polyol component (described later).

  And since the dispersing agent does not contain a protective colloid, the water-dispersed block isocyanate composition obtained in this way can ensure the outstanding emulsion stability and storage stability.

  In addition, such a water-dispersed blocked isocyanate composition contains a surfactant containing an HLB16 or higher aromatic nonionic surfactant having a hydroxy group at the molecular terminal as an essential component, and thus has excellent water resistance. A polyurethane resin having properties, appearance and transparency can be obtained.

  More specifically, such a water-dispersed blocked isocyanate composition is, for example, an isocyanate component (curing agent) of various polyurethane resins, more specifically, a two-component curable polyurethane resin (for example, paint, adhesive). It is used as an isocyanate component (curing agent).

  In the two-component curable polyurethane resin, for example, an isocyanate component (curing agent) composed of the above water-dispersed blocked isocyanate composition and a polyol component (main agent) are individually prepared and blended at the time of use.

  As a polyol component, a macro polyol is mentioned, for example.

  The macropolyol is an organic compound having two or more hydroxyl groups and a number average molecular weight of 400 or more. For example, a polybasic acid (for example, adipic acid, sebacic acid, phthalic acid, isophthalic acid, etc.) and a low molecular weight polyol (for example, A polyester polyol obtained by a known esterification reaction such as a condensation reaction with ethylene glycol, propylene glycol, butanediol, neopentyl glycol, etc., for example, a hydroxyl group-containing vegetable oil fatty acid (for example, a low molecular weight polyol as described above) Vegetable oil-based polyester polyols obtained by condensation reaction of hydroxycarboxylic acids such as castor oil fatty acid containing ricinoleic acid, hydrogenated castor oil fatty acid containing 12-hydroxystearic acid, etc. As an initiator, for example, lactones such as ε-caprolactone and γ-valerolactone can be obtained by ring-opening polymerization, and obtained by polycaprolactone polyol, for example, ring-opening polymerization of alkylene oxide using a low molecular weight polyol as an initiator. Polyether polyol, for example, polycarbonate polyol obtained by reacting phosgene, dialkyl carbonate, diallyl carbonate, alkylene carbonate, etc. with low molecular weight polyol as initiator, for example, known hydroxyl group-containing acrylate and its hydroxyl group-containing acrylate Acrylic polyols obtained by copolymerizing a copolymerizable vinyl monomer that can be copolymerized with polyesters such as those polyols (polyester polyols, polyether polyols). , Polycarbonate polyol, polyacryl polyol, etc.), a urethane-modified polyol (polyurethane resin (for example, polyurethane resin (for example, Polyester type polyurethane polyol, polyether type polyurethane polyol, polycarbonate type polyurethane polyol, polyacryl type polyurethane polyol, or polyester polyether type polyurethane polyol)).

  These macropolyols can be used alone or in combination of two or more.

  As the macro polyol, preferably, a polyurethane resin (urethane-modified polyol) is used.

  In the two-component curable polyurethane resin, the blending ratio of the water-dispersed blocked isocyanate composition (isocyanate component) and the macropolyol (polyol component) is, for example, the isocyanate group of the water-dispersed blocked isocyanate composition relative to the hydroxyl group of the macropolyol ( The equivalent ratio (isocyanate group / active hydrogen group) of the isocyanate group blocked by the blocking agent is, for example, 0.5 to 5, preferably 0.6 to 3.

  The reaction conditions are not particularly limited as long as the blocking agent in the water-dispersed blocked isocyanate composition is dissociated. Specifically, the reaction temperature is, for example, 80 to 200 ° C., preferably 100 to 180 ° C.

  As a result, the blocking agent in the water-dispersed blocked isocyanate composition can be dissociated, and the regenerated isocyanate group of the water-dispersed blocked isocyanate composition can be reacted with the hydroxyl group of the macropolyol. Can be cured.

  In such a method, if necessary, either one or both of the water-dispersed blocked isocyanate composition (isocyanate component) and the macropolyol (polyol component) may be used, for example, a reaction solvent, a catalyst. , Epoxy resins, coating improvers, leveling agents, antifoaming agents, stabilizers such as antioxidants and UV absorbers, plasticizers, surfactants, pigments, fillers, organic or inorganic fine particles, antifungal agents These additives can be appropriately blended. The compounding amount of the additive is appropriately determined depending on the purpose and application.

  And since the above-mentioned water dispersion type block isocyanate composition is used, the polyurethane resin obtained in this way can be equipped with the outstanding water resistance, external appearance, and transparency.

  The water-dispersed blocked isocyanate composition of the present invention is not limited to the above polyurethane resin, and can be used as a curing agent for various known resins such as polyolefin resins, polyacrylic resins, and polyester resins. .

Next, although this invention is demonstrated based on an Example and a comparative example, this invention is not limited by the following Example.
(component)
1. Isocyanate Compound (1) Takenate D-110N (xylylene diisocyanate trimethylolpropane adduct, solid content 75%, manufactured by Mitsui Chemicals)
(2) Takenate D-160N (hexamethylene diisocyanate trimethylolpropane adduct, solid content 75%, manufactured by Mitsui Chemicals)
2. 2. Blocking agent (1) 3,5-dimethylpyrazole (2) methyl ethyl ketoxime 3. Organic solvent methyl ethyl ketone Surfactant (1) Emulgen A-500 (polyoxyethylene distyrenated phenyl ether solid content concentration: 100% by mass, HLB: 18.0, manufactured by Kao Corporation)
(2) CP-20 (polyoxyethylene cumylphenyl ether, solid content concentration: 100% by mass, HLB: 16.3, manufactured by Toho Chemical Industry Co., Ltd.)
(3) Neugen EA177 (polyoxyethylene styryl phenyl ether, solid content concentration: 100% by mass, HLB: 17.0, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
(4) Nonal 912A (polyoxyethylene cumyl phenyl ether, solid content concentration: 100% by mass, HLB: 14.3, manufactured by Toho Chemical Industry Co., Ltd.)
(5) Neugen EA87 (polyoxyethylene styryl phenyl ether, solid content concentration: 100% by mass, HLB: 10.6, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
(6) Pegnol C-40 (polyoxyethylene alkyl ether, solid content concentration 100% by mass, HLB: 17.6, manufactured by Toho Chemical Industry Co., Ltd.)
(7) Sannol TD-3130 (polyoxyethylene alkyl ether sulfate sodium salt, solid content concentration 31% by mass, manufactured by Lion Corporation)
(8) LUNOX 100 (Sodium alkylbenzene sulfonate, solid concentration 60 mass%, manufactured by Toho Chemical Industry Co., Ltd.)
(9) Emar E-27C (Sodium polyoxyethylene lauryl ether sulfate, solid content concentration 27% by mass, manufactured by Kao Corporation)
5. Protective colloid agent (1) Kuraray Poval PVA205 (partially saponified polyvinyl alcohol, saponification degree: 87.0-89.0 mol%, polymerization degree: 500, manufactured by Kuraray Co., Ltd.)
(2) Kuraray Poval PVA217 (partially saponified polyvinyl alcohol, degree of saponification: 87.0-89.0 mol%, degree of polymerization: 1700, manufactured by Kuraray Co., Ltd.)
6). Water-based urethane resin (1) Takelac W-5030 (polyester type urethane-modified polyol (aqueous polyurethane resin), manufactured by Mitsui Chemicals)
(2) Takelac W-5100 (polycarbonate-type urethane-modified polyol (aqueous polyurethane resin), manufactured by Mitsui Chemicals)
(Synthesis of blocked isocyanate)
Production Example 1 (Blocked isocyanate (a))
A four-necked flask equipped with a stirrer, thermometer, and reflux condenser was replaced with nitrogen, and then charged with Takenate D-110N682 parts by mass and methyl ethyl ketone 129.5 parts by mass, and stirred, and Takenate D-110N was converted into methyl ethyl ketone. Dissolved.

  Subsequently, 188.5 mass parts of 3, 5- dimethyl pyrazole was added over 1 hour, stirring internal temperature at 50-60 degreeC and stirring.

  Then, after stirring for 1 hour at an internal temperature of 50 ° C. and confirming that the solid of 3,5-dimethylpyrazole was completely dissolved, absorption of the isocyanate group disappeared by FT-IR (Fourier transform infrared spectrophotometer). It was confirmed that the blocked isocyanate (a) was obtained.

Production Example 2 (Blocked isocyanate (b))
A four-necked flask equipped with a stirrer, a thermometer, and a reflux condenser was replaced with nitrogen, and then charged with 599.7 parts by mass of Takenate D-110N and 125.1 parts by mass of methyl ethyl ketone, stirred, and Takenate D-110N. Was dissolved in methyl ethyl ketone.

  Next, 175.2 parts by mass of methyl ethyl ketoxime was added over 1 hour while maintaining the internal temperature at 50 to 60 ° C. and stirring.

  Thereafter, the mixture was stirred at an internal temperature of 50 ° C. for 1 hour, and it was confirmed by FT-IR (Fourier transform infrared spectrophotometer) that the absorption of the isocyanate group had disappeared, thereby obtaining a blocked isocyanate (b).

Production Example 3 (Blocked isocyanate (c))
A four-necked flask equipped with a stirrer, a thermometer, and a reflux condenser was replaced with nitrogen, and then it was charged with 644.9 parts by mass of Takenate D-160N and 133.8 parts by mass of methyl ethyl ketone, stirred and Takenate D-160N. Was dissolved in methyl ethyl ketone.

  Next, 201.3 parts by mass of 3,5-dimethylpyrazole was added over 1 hour with stirring while maintaining the internal temperature at 50 to 60 ° C.

Then, after stirring for 1 hour at an internal temperature of 50 ° C. and confirming that the solid of 3,5-dimethylpyrazole was completely dissolved, absorption of the isocyanate group disappeared by FT-IR (Fourier transform infrared spectrophotometer). It was confirmed that blocked isocyanate (c) was obtained.
(Preparation of water-dispersed blocked isocyanate composition)
Example 1
While stirring 500 parts by mass of the blocked isocyanate synthesized in Production Example 1 with a homomixer (rotation speed: 4000 rpm), 17.5 parts by mass of Nonal 912A was added to the blocked isocyanate over 30 minutes.

  Next, 140 parts by mass of a 25% by weight aqueous solution of Emulgen A-500 was added to the blocked isocyanate over 30 minutes, and then 645 parts by mass of ion-exchanged water was added over 30 minutes for emulsification.

  Thereafter, 0.18 part by mass of an antifoaming agent (BYK-022, manufactured by Big Chemie) was added and stirred for 1 hour at 1000 rpm, and then heated in a hot water bath at 50 ° C. under reduced pressure to prepare an organic solvent ( Methyl ethyl ketone used in Production Example 1 was distilled off, and water was partially distilled off to obtain a water-dispersed blocked isocyanate composition (A) having a solid content of 40%.

Examples 2-9 and Comparative Examples 1-7
Except having set it as the mixing | blending prescription shown in Table 1, it carried out similarly to Example 1, and obtained water dispersion type | mold block isocyanate composition (B)-(P).
(Evaluation)
<Emulsification stability>
The emulsification stability of each water-dispersed blocked isocyanate composition obtained in each example and each comparative example was visually evaluated. The results are shown in Table 1.

The evaluation criteria are shown below.
◎ ・ ・ ・ Emulsified without problems.
○: Emulsification was possible, but a slight aggregate was observed.
X: Unable to emulsify (no water dispersion was obtained because of phase separation into water and resin).
<Storage stability>
Each water-dispersed blocked isocyanate composition obtained in each example and each comparative example was allowed to stand at 25 ° C. for 1 week, and its storage stability was visually evaluated. The results are shown in Table 1.

The evaluation criteria are shown below.
○: Phase separation was not observed.
X: Phase separation occurred within one week.
<Average particle size>
The volume average particle diameter of the blocked isocyanate of each water-dispersed blocked isocyanate composition obtained in each example and each comparative example was measured with a submicron particle analyzer N5 (manufactured by BECKMAN COULTER). The results are shown in Table 1.

<Water resistance evaluation>
2 parts by mass of the water-dispersed blocked isocyanate composition (A) and 20 parts by mass of Takelac W-5030 were mixed, stirred and mixed, and then applied to a glass plate with an applicator so that the film thickness was 100 μm. .

  Next, the coating film was cured by heating at 130 ° C. or 160 ° C. for 30 minutes with a dryer. Thereafter, the glass plate and the coating film were cooled to obtain a test piece.

  And water was dripped at the coating-film surface of a test piece, the test piece was coat | covered so that water might not evaporate, and the state (presence of whitening) of the coating film after leaving still for 24 hours was confirmed visually.

Further, the water resistance of each of the water-dispersed blocked isocyanate compositions (B) to (D), (I), (J), (O), and (P) was visually evaluated. The results are shown in Table 2.
<Transparency and appearance evaluation of coating film>
10 parts by mass of the water-dispersed blocked isocyanate composition (A) and 10 parts by mass of Takelac WS-5100 were mixed, stirred and mixed, and then applied to a PET film having a thickness of 12 μm so that the film thickness was 3 μm. .

  And the coating film was heated and dried with the dryer (hot air). Thereafter, the transparency and appearance (surface state) of the coating film were visually evaluated.

  Further, the transparency and appearance (surface state) of each of the water-dispersed blocked isocyanate compositions (B) to (D), (I), (J), (O) and (P) were visually evaluated. The results are shown in Table 2.

The evaluation criteria are shown below.
(Transparency evaluation)
◎: Transparent ○: Slightly cloudy ×: Cloudy (appearance evaluation)
(Double-circle): There was no spot etc. and the uniform coating film was formed.
○: Slight white spots were generated.
X: White spots were generated as a whole.

Claims (5)

A water-dispersed blocked isocyanate composition containing a blocked isocyanate in which an isocyanate group is blocked by a blocking agent, and a dispersant,
The dispersant does not contain a protective colloid agent, contains a surfactant,
The surfactant is
A water-dispersed blocked isocyanate composition comprising an HLB16 or higher aromatic nonionic surfactant having a hydroxy group at a molecular end.   2. The water-dispersed blocked isocyanate composition according to claim 1, wherein the surfactant further contains an aromatic nonionic surfactant having a hydroxy group at a molecular terminal and less than HLB16. 3.   The water-dispersed blocked isocyanate composition according to claim 1 or 2, comprising 0.1 to 3 parts by mass of an anionic surfactant with respect to 100 parts by mass of the blocked isocyanate.   The water-dispersed blocked isocyanate composition according to any one of claims 1 to 3, wherein the block isocyanate has a volume average particle diameter of 300 nm or less.   A polyurethane resin obtained by a reaction between an isocyanate component comprising the water-dispersed blocked isocyanate composition according to claim 1 and a polyol component.