JP6626423B2 - Polyisocyanate composition and polyurethane resin - Google Patents

Description

  The present invention relates to a polyisocyanate composition and a polyurethane resin, and more particularly, to a polyisocyanate composition and a polyurethane resin using the polyisocyanate composition.

  Polyurethane resins are usually produced by a reaction between a polyisocyanate and an active hydrogen compound, and are widely used in various industrial fields, for example, as paints, adhesives, elastomers, and the like.

  When such a polyurethane resin is used as a coating film, for example, excellent mechanical properties and chemical resistance may be required.In such a case, pentamethylene diisocyanate is used as a raw material. It is known to use a low molecular weight polyol having an average functional group number of 2 to 3.9, specifically, a polyisocyanate composition obtained by a reaction with trimethylolpropane or the like (for example, Patent Document 1 See Example 1).).

  A polyurethane resin obtained by reacting such a polyisocyanate composition with a polyol can have excellent mechanical properties and chemical resistance.

JP 2010-265364 A

  On the other hand, there is a case where a polyurethane resin is required to further improve mechanical properties and chemical resistance, and is also required to improve workability during production of the polyurethane resin.

  An object of the present invention is to provide a polyisocyanate composition that can impart excellent mechanical properties and chemical resistance to various industrial materials and can be manufactured with good workability, and a polyurethane resin using the polyisocyanate composition. Is to provide.

  In order to achieve the above object, the polyisocyanate composition of the present invention is obtained by reacting an aliphatic polyisocyanate with a polyol containing ditrimethylolpropane.

  In the polyisocyanate composition of the present invention, it is preferable that the polyol is composed of ditrimethylolpropane and trimethylolpropane, and the content of ditrimethylolpropane relative to the total amount of the polyol is 5 mol% or more.

  In the polyisocyanate composition of the present invention, the average number of isocyanate functional groups is preferably from 3 to 5.5.

  In the polyisocyanate composition of the present invention, the polyisocyanate is preferably composed of pentamethylene diisocyanate.

  Further, the polyurethane resin of the present invention is obtained by reacting the above polyisocyanate composition with an active hydrogen compound.

  Since the polyisocyanate composition of the present invention is obtained by the reaction of an aliphatic polyisocyanate with a polyol containing ditrimethylolpropane, it is possible to impart excellent mechanical properties and chemical resistance to various industrial materials, and to improve workability. Can be manufactured well.

  Therefore, the polyurethane resin using the polyisocyanate composition of the present invention can be used widely in various industrial fields.

  The polyisocyanate composition of the present invention can be obtained by reacting an aliphatic polyisocyanate with a polyol.

  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), pentane Methylene diisocyanate (1,5-pentamethylene diisocyanate, PDI), hexamethylene diisocyanate (1,6-hexamethylene diisocyanate, HDI), 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, 2,6 -Aliphatic diisocyanates such as diisocyanate methyl caprate.

The aliphatic polyisocyanate includes an alicyclic polyisocyanate. 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) (IPDI), methylenebis (cyclohexylisocyanate) (4,4'-, 2,4'- or 2,2'-methylenebis (cyclohexylisocyanate, Trans, Trans - body, Trans, Cis body, Cis, Cis body, or mixtures _thereof)) (H 12 _MDI), methylcyclohexane diisocyanate (methyl-2,4-cyclohexane Isocyanate, methyl-2,6-cyclohexane diisocyanate), norbornane diisocyanate (various isomers or mixtures thereof) (NBDI), bis (isocyanatomethyl) cyclohexane (1,3- or 1,4-bis (isocyanatomethyl) cyclohexane Or a mixture thereof) (H ₆ XDI).

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

  As the aliphatic polyisocyanate, preferably, pentamethylene diisocyanate is used.

  By using pentamethylene diisocyanate, a polyisocyanate composition having a high isocyanate group concentration and capable of obtaining a polyurethane resin having excellent mechanical properties and chemical resistance can be obtained.

  The polyol contains ditrimethylolpropane (abbreviation: Di-TMP).

  Ditrimethylolpropane is also called bis (2,2-dihydroxymethylbutyl) ether or 2,2′-diethyl-2,2 ′-(oxydimethyl) bis (propane-1,3-diol) and has a melting point of 109. It is a tetravalent polyol at ℃, and is represented by the following formula (1).

  Dimethylolpropane can be obtained as a raw material from trimethylolpropane (abbreviation: TMP), for example, by the method described in JP-A-9-268150, or can be obtained as a commercial product.

  Since ditrimethylolpropane has a relatively low melting point, it is easier to handle than when using other tetravalent polyols having a relatively high melting point (eg, 150 ° C. or higher) (for example, pentaerythritol). Therefore, if ditrimethylolpropane is used, the workability in the production of the polyisocyanate composition can be improved.

  In addition, the polyol can preferably contain, in addition to ditrimethylolpropane, other low-molecular-weight polyols (low-molecular-weight polyols other than ditrimethylolpropane).

  The low molecular weight polyol is a compound having two or more hydroxyl groups and having a number average molecular weight of less than 300, preferably less than 400, for example, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butylene glycol, 1,3-butylene glycol, 1,2-butylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2,2-trimethyl Pentanediol, 3,3-dimethylolheptane, alkane (C7-20) diol, 1,3- or 1,4-cyclohexanedimethanol and mixtures thereof, 1,3- or 1,4-cyclohexanediol and their Mixture, hydrogenated bisphenol A, 1,4-dihydroxy- Dihydric alcohols such as butene, 2,6-dimethyl-1-octene-3,8-diol, bisphenol A, diethylene glycol, triethylene glycol, dipropylene glycol, for example, glycerin, trimethylolpropane, triisopropanolamine and the like; Trihydric alcohols, for example, tetrahydric alcohols such as tetramethylolmethane (pentaerythritol) and diglycerin, for example, pentahydric alcohols such as xylitol, for example, sorbitol, mannitol, allitol, iditol, darcitol, altitol, inositol, dipental Examples include hexahydric alcohols such as erythritol, for example, heptahydric alcohols such as perseitol, and octahydric alcohols such as sucrose.

  These low molecular weight polyols can be used alone or in combination of two or more.

  As the low molecular weight polyol, preferably, a trihydric alcohol, more preferably, trimethylolpropane is used.

  That is, the polyol preferably comprises ditrimethylolpropane and trimethylolpropane.

  When the polyol is composed of ditrimethylolpropane and trimethylolpropane, the viscosity of the polyisocyanate composition can be reduced. In particular, when the content ratio of ditrimethylolpropane and trimethylolpropane is in the following range, the viscosity can be more favorably reduced.

  When the polyol contains ditrimethylolpropane and another low-molecular-weight polyol, the content thereof is such that ditrimethylolpropane is, for example, at least 5 mol%, preferably at least 5 mol%, based on the total amount (total mole) of the polyol. , 50 mol% or more, usually less than 100 mol%, preferably 95 mol% or less. In addition, other low molecular weight polyols usually exceed 0 mol%, preferably 5 mol% or more, for example, 95 mol% or less, preferably 50 mol% or less.

  When the content of ditrimethylolpropane in the polyol is within the above range, a polyurethane resin having both hardness and flexibility can be obtained.

  Further, the molecular weight of the polyol (number average molecular weight when two or more kinds are used in combination) is, for example, 100 or more, preferably 140 or more, and for example, 400 or less, preferably 260 or less.

  The hydroxyl value of the polyol is, for example, 500 mgKOH / g or more, preferably 890 mgKOH / g or more, and for example, 2000 gKOH / g or less, preferably 1250 mgKOH / g or less.

  The hydroxyl value can be determined by a known titration method, and the hydroxyl value and the hydroxyl equivalent have the relationship of the following formula (2).

Hydroxyl value = 56100 / hydroxyl equivalent (2)
The average number of functional groups of the polyol is, for example, 2.5 or more, preferably 3 or more, more preferably 3.5 or more, for example, 6 or less, preferably 5 or less, more preferably 4 or less. It is.

The average functional group number of the polyol, when using ditrimethylolpropane and other low molecular weight polyols in combination, the hydroxyl equivalent and molecular weight of each polyol compound (ditrimethylolpropane and other low molecular weight polyols) used in combination, the following formula: It can be calculated by (3).
(Average number of functional groups of polyol) = (sum of (weight of each polyol compound / hydroxyl equivalent of each polyol compound)) / (sum of (weight of each polyol compound / molecular weight of each polyol compound)) (3)
And in this invention, a polyisocyanate composition is obtained by urethane-forming reaction of an aliphatic polyisocyanate and a polyol.

  More specifically, to obtain a polyisocyanate composition, the equivalent ratio of the isocyanate group of the aliphatic polyisocyanate to the active hydrogen group (hydroxy group) of the polyol (isocyanate group / active hydrogen group) is, for example, 3 to 3. They are blended at a ratio of 20, preferably 3 to 10, more preferably 4 to 8, and reacted by a known urethanation reaction.

  The reaction conditions in the urethanization reaction include, for example, an inert gas atmosphere such as a nitrogen gas, and a normal temperature (atmospheric pressure) at a reaction temperature of, for example, 40 to 120 ° C, preferably 50 to 100 ° C, and furthermore, Preferably, it is 60 to 90 ° C., and the reaction time is, for example, 0.5 to 30 hours, preferably 1 to 20 hours, more preferably 1 to 10 hours.

  The urethanization reaction ends when the desired isocyanate group content (the theoretical amount of the unreacted isocyanate group concentration calculated from the charged amount) in the reaction system is reached.

  In the urethanization reaction, if necessary, a known urethanization catalyst such as an amine or an organic metal compound may be added, or a known organic solvent may be added.

  As the amines, for example, tertiary amines such as triethylamine, triethylenediamine, bis- (2-dimethylaminoethyl) ether, N-methylmorpholine, and the like, for example, quaternary ammonium salts such as tetraethylhydroxylammonium, for example, imidazole, And imidazoles such as 2-ethyl-4-methylimidazole.

  Examples of the organometallic compound include tin acetate, tin octylate, tin oleate, tin laurate, dibutyltin diacetate, dimethyltin dilaurate, dibutyltin dilaurate, dibutyltin dimercaptide, dibutyltin maleate, dibutyltin dilaurate, and dibutyltin. Dinedecanoate, dioctyltin dimercaptide, dioctyltin dilaurate, organic tin-based compounds such as dibutyltin dichloride, for example, lead octanoate, organic lead compounds such as lead naphthenate, for example, organic nickel compounds such as nickel naphthenate, Examples thereof include organic cobalt compounds such as cobalt naphthenate, for example, organic copper compounds such as copper octenoate, and organic bismuth compounds such as bismuth octylate and bismuth neodecanoate.

  Further, examples of the urethanization catalyst include potassium salts such as potassium carbonate, potassium acetate, and potassium octylate.

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

  As the organic solvent, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, ketones such as cyclohexanone, nitriles such as acetonitrile, methyl acetate, ethyl acetate, butyl acetate, alkyl esters such as isobutyl acetate, for example, n- Aliphatic hydrocarbons such as hexane, n-heptane, and octane, for example, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, for example, aromatic hydrocarbons such as toluene, xylene, and ethylbenzene, for example, methyl cellosolve acetate , Ethyl cellosolve acetate, methyl carbitol acetate, ethyl carbitol acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxy Glycol ether esters such as butyl acetate and ethyl-3-ethoxypropionate, for example, ethers such as diethyl ether, tetrahydrofuran and dioxane, for example, methyl chloride, methylene chloride, chloroform, carbon tetrachloride, methyl bromide, iodine Halogenated aliphatic hydrocarbons such as methylene halide and dichloroethane, and polar aprotons such as N-methylpyrrolidone, dimethylformamide, N, N'-dimethylacetamide, dimethylsulfoxide, hexamethylphosphonylamide, and the like. .

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

  In this urethanization reaction, free (unreacted) aliphatic polyisocyanate can also be removed.

  In other words, the polyisocyanate composition is in a state where the unreacted aliphatic polyisocyanate is mixed, that is, the reaction product of the aliphatic polyisocyanate and the polyol (the polyol adduct of the aliphatic polyisocyanate) and the unreacted Obtained as a mixture with an aliphatic polyisocyanate.

  When the concentration of the unreacted aliphatic polyisocyanate in the obtained polyisocyanate composition (hereinafter, sometimes referred to as the residual monomer concentration) is high, preferably, the unreacted aliphatic polyisocyanate is unreacted from the polyisocyanate composition. Remove polyisocyanate and reduce residual monomer concentration.

  Examples of a method for removing unreacted aliphatic polyisocyanate include a known method such as a distillation method such as a thin film distillation method and an extraction method such as a liquid-liquid extraction method.

  The polyisocyanate composition thus obtained has an isocyanate group concentration (solvent-free) of, for example, 13% by mass or more, preferably 14% by mass or more, more preferably 16.7% by mass or more, For example, the content is 22% by mass or less, preferably 20% by mass or less, and more preferably 18.7% by mass or less.

  In the polyisocyanate composition thus obtained, the residual monomer concentration (concentration of unreacted aliphatic polyisocyanate) is, for example, 3% by mass or less, preferably 1% by mass or less, more preferably It is 0.5% by mass or less.

  Further, the viscosity at 25 ° C. of the polyisocyanate composition (solvent-free) thus obtained is, for example, 1000 mPa · s or more, preferably 2000 mPa · s or more, more preferably 10,000 mPa · s or more, For example, it is 200000 mPa · s or less, preferably 180000 mPa · s or less, more preferably 150,000 mPa · s or less. In addition, the measuring method of a viscosity is based on the Example mentioned later.

  The polyisocyanate composition thus obtained has a number average molecular weight of, for example, 700 or more, preferably 800 or more, more preferably 900 or more, for example, 1300 or less, preferably 1200 or less, More preferably, it is 1100 or less.

  The number average molecular weight referred to here is the number average molecular weight in terms of polyethylene oxide of the polyisocyanate composition measured by gel permeation chromatography.

  The average number of isocyanate functional groups in the polyisocyanate composition is, for example, 2.5 or more, preferably 3 or more, more preferably 4 or more, and for example, 7 or less, preferably 5.5 or less, more preferably Is 5 or less.

  When the average number of isocyanate groups in the polyisocyanate composition is in the above range, a polyurethane resin having excellent mechanical properties and chemical resistance can be obtained.

  The average number of isocyanate functional groups in the polyisocyanate composition can be calculated from the following formula (4) from the isocyanate group concentration, the solid content concentration and the number average molecular weight of gel permeation chromatography of the polyisocyanate composition.

Average number of isocyanate functional groups = A / B × C / 42.02 (4)
(In the formula, A indicates an isocyanate group concentration, B indicates a solid content concentration, and C indicates a number average molecular weight.)
The polyisocyanate composition thus obtained can be used for paints, adhesives, and many other industrial uses without being diluted with a solvent, but when an organic solvent is added in the preparation of the polyisocyanate composition. It can be used in the state of being dissolved in the organic solvent, and if necessary, it can be further dissolved in various organic solvents.

  As the organic solvent, for example, acetone, methyl ethyl ketone, methyl isobutyl ketone, ketones such as cyclohexanone, for example, nitriles such as acetonitrile, methyl acetate, ethyl acetate, butyl acetate, alkyl esters such as isobutyl acetate, for example, n- Aliphatic hydrocarbons such as hexane, n-heptane, and octane, for example, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane, for example, aromatic hydrocarbons such as toluene, xylene, and ethylbenzene, for example, methyl cellosolve acetate , Ethyl cellosolve acetate, methyl carbitol acetate, ethyl carbitol acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxy Glycol ether esters such as butyl acetate and ethyl-3-ethoxypropionate, for example, ethers such as diethyl ether, tetrahydrofuran and dioxane, for example, methyl chloride, methylene chloride, chloroform, carbon tetrachloride, methyl bromide, iodine Halogenated aliphatic hydrocarbons such as methylene halide and dichloroethane, and polar aprotons such as N-methylpyrrolidone, dimethylformamide, N, N'-dimethylacetamide, dimethylsulfoxide, hexamethylphosphonylamide, and the like. .

  Furthermore, examples of the organic solvent include non-polar solvents (non-polar organic solvents). Examples of these non-polar solvents include aliphatic and naphthenic hydrocarbon-based organic solvents. Examples include non-polar organic solvents having a low toxicity and a low solubility at 70 ° C., preferably 12 to 65 ° C., and vegetable oils represented by turpen oil.

  When the polyisocyanate composition is dissolved in an organic solvent, the viscosity of the solution at 25 ° C. is, for example, 100 mPa · s or more, preferably 250 mPa · s or more, more preferably 320 mPa · s or more. Yes, for example, 1000 mPa · s or less, preferably 750 mPa · s or less, more preferably 500 mPa · s or less. In addition, the measuring method of a viscosity is based on the Example mentioned later.

  Since the polyisocyanate composition of the present invention is obtained by the reaction of an aliphatic polyisocyanate with a polyol containing ditrimethylolpropane, it is possible to impart excellent mechanical properties and chemical resistance to various industrial materials, and to improve workability. Can be manufactured well.

  Specifically, the polyisocyanate composition can be used as a cross-linking agent or a curing agent for various synthetic resins, and in particular, can be used as a raw material for a polyurethane resin.

  Therefore, the polyurethane resin using the polyisocyanate composition of the present invention can be used widely in various industrial fields.

  Specifically, the polyurethane resin of the present invention can be obtained by reacting the above polyisocyanate composition with an active hydrogen compound.

  In the present invention, examples of the active hydrogen compound include a polyol component (a component mainly containing a polyol having two or more hydroxyl groups) and a polyamine component (a compound mainly containing a polyamine having two or more amino groups). .

  In the present invention, examples of the polyol component include a low molecular weight polyol and a high molecular weight polyol.

  Examples of the low-molecular-weight polyol include low-molecular-weight polyols similar to the low-molecular-weight polyol described above.

  The high molecular weight polyol is a compound having a number average molecular weight of 300 or more having two or more hydroxyl groups, preferably 400 or more, more preferably 500 or more, for example, polyether polyol, polyester polyol, polycarbonate polyol, polyurethane polyol, Examples include epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols.

  Examples of the polyether polyol include a polyoxyalkylene polyol and a polytetramethylene ether polyol.

  The polyoxyalkylene polyol is, for example, an addition polymer of an alkylene oxide using the above-described low molecular weight polyol or the like, an aromatic polyamine, an aliphatic polyamine or the like as an initiator.

  Examples of the alkylene oxide include propylene oxide, ethylene oxide, butylene oxide, styrene oxide and the like. These alkylene oxides can be used alone or in combination of two or more. Of these, propylene oxide and ethylene oxide are preferred. The polyoxyalkylene polyol includes, for example, a random and / or block copolymer of propylene oxide and an alkylene oxide such as ethylene oxide.

  Examples of the polytetramethylene ether polyol include a ring-opened polymer obtained by cationic polymerization of tetrahydrofuran, and an amorphous (non-crystalline) obtained by copolymerizing a polymer unit such as tetrahydrofuran with an alkyl-substituted tetrahydrofuran or the above-mentioned dihydric alcohol. G) polytetramethylene ether glycol.

  In addition, non-crystalline (non-crystalline) means that it is liquid at normal temperature (25 ° C.).

  The amorphous polytetramethylene ether glycol is, for example, a copolymer of tetrahydrofuran and an alkyl-substituted tetrahydrofuran (for example, 3-methyltetrahydrofuran or the like) (tetrahydrofuran / alkyl-substituted tetrahydrofuran (molar ratio) = 15 / 85-85 / 15, a number average molecular weight of 500 to 4000, preferably 800 to 2500) or a copolymer of tetrahydrofuran and a branched glycol (for example, neopentyl glycol or the like) (tetrahydrofuran / branched glycol (molar ratio) = 15 / 85-85 / 15, number average molecular weight 500-4000, preferably 800-2500).

  Examples of the polyester polyol include a polycondensate obtained by reacting the above-mentioned low molecular weight polyol with a polybasic acid under known conditions.

  Examples of polybasic acids include oxalic acid, malonic acid, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, 1,1-dimethyl-1,3-dicarboxypropane, and 3-methyl-3-ethylglutaric acid , Azelaic acid, sebacic acid and other saturated aliphatic dicarboxylic acids (C11-13) such as maleic acid, fumaric acid, itaconic acid and other unsaturated aliphatic dicarboxylic acids such as orthophthalic acid, isophthalic acid and terephthalic acid , Toluene dicarboxylic acid, naphthalenedicarboxylic acid, other aromatic dicarboxylic acids, for example, hexahydrophthalic acid, other alicyclic dicarboxylic acids, for example, dimer acid, hydrogenated dimer acid, other carboxylic acids such as het acid, And acid anhydrides derived from these carboxylic acids, for example, oxalic anhydride, succinic anhydride , Maleic anhydride, phthalic anhydride, 2-alkyl (C12-C18) succinic acid, tetrahydrophthalic anhydride, trimellitic anhydride, and acid halides derived from these carboxylic acids, such as oxalic acid Dichloride, adipic dichloride, sebacic dichloride and the like.

  Further, as the polyester polyol, for example, a plant-derived polyester polyol, specifically, the above-described low molecular weight polyol is used as an initiator, and a hydroxyl group-containing vegetable oil fatty acid (for example, castor oil fatty acid containing ricinoleic acid, 12-hydroxystearic acid) And vegetable oil-based polyester polyols obtained by subjecting a hydroxycarboxylic acid such as a hydrogenated castor oil fatty acid containing a) to a condensation reaction under known conditions.

  Further, as the polyester polyol, for example, the above-mentioned low molecular weight polyol (preferably, dihydric alcohol) is used as an initiator, and for example, lactones such as ε-caprolactone, γ-valerolactone, and L-lactide, D-lactone; Examples thereof include polycaprolactone polyols and polyvalerolactone polyols obtained by ring-opening polymerization of lactides such as lactide and the like, and lactone-based polyester polyols obtained by copolymerizing the above-mentioned dihydric alcohols with them.

  Examples of the polycarbonate polyol include, for example, a ring-opening polymer of ethylene carbonate having the above-mentioned low molecular weight polyol (preferably, dihydric alcohol) as an initiator, and 1,4-butanediol, 1,5-pentanediol, and the like. Amorphous polycarbonate polyols obtained by copolymerizing a dihydric alcohol such as 3-methyl-1,5-pentanediol or 1,6-hexanediol with a ring-opening polymer are exemplified.

  Further, the polyurethane polyol is obtained by mixing the polyester polyol, polyether polyol and / or polycarbonate polyol obtained as described above at a ratio where the equivalent ratio of hydroxyl group (OH) to isocyanate group (NCO) (OH / NCO) exceeds 1, By reacting with a polyisocyanate, it can be obtained as a polyester polyurethane polyol, a polyether polyurethane polyol, a polycarbonate polyurethane polyol, a polyester polyether polyurethane polyol, or the like.

  Epoxy polyols include, for example, epoxy polyols obtained by reacting the above-mentioned low molecular weight polyols with, for example, polyfunctional halohydrins such as epichlorohydrin and β-methylepichlorohydrin.

  Examples of the vegetable oil polyol include a hydroxyl group-containing vegetable oil such as castor oil and coconut oil. For example, a castor oil polyol, or an ester-modified castor oil polyol obtained by reacting a castor oil fatty acid with a polypropylene polyol may be used.

  Examples of the polyolefin polyol include a polybutadiene polyol and a partially saponified ethylene-vinyl acetate copolymer.

  Examples of the acrylic polyol include a copolymer obtained by copolymerizing a hydroxyl group-containing acrylate and a copolymerizable vinyl monomer copolymerizable with the hydroxyl group-containing acrylate.

  Examples of the hydroxyl group-containing acrylate include 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 2,2-dihydroxymethylbutyl (meth) acrylate, polyhydroxyalkyl maleate, And polyhydroxyalkyl fumarate. Preferably, 2-hydroxyethyl (meth) acrylate is used.

  Examples of the copolymerizable vinyl monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and s-butyl ( Alkyl (such as meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, isononyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and cyclohexyl acrylate (Meth) acrylates (having 1 to 12 carbon atoms), for example, aromatic vinyls such as styrene, vinyltoluene and α-methylstyrene; for example, vinyl cyanide such as (meth) acrylonitrile; ) A vinyl monomer containing a carboxyl group such as acrylic acid, fumaric acid, maleic acid, and itaconic acid, or an alkyl ester thereof, for example, ethylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, hexanediol di (meth) ) Alkane polyol poly (meth) acrylates such as acrylate, oligoethylene glycol di (meth) acrylate, trimethylolpropane di (meth) acrylate, and trimethylolpropane tri (meth) acrylate, for example, 3- (2-isocyanate-2-) Vinyl monomer containing an isocyanate group such as propyl) -α-methylstyrene.

  The acrylic polyol can be obtained by copolymerizing the hydroxyl group-containing acrylate and the copolymerizable vinyl monomer in the presence of a suitable solvent and a polymerization initiator.

  The acrylic polyol includes, for example, silicone polyol and fluorine polyol.

  Examples of the silicone polyol include, for example, an acrylic polyol in which a silicone compound containing a vinyl group such as γ-methacryloxypropyltrimethoxysilane is blended as a copolymerizable vinyl monomer in the above-described copolymerization of the acrylic polyol. .

  As the fluorine polyol, for example, in the copolymerization of the acrylic polyol described above, as the copolymerizable vinyl monomer, for example, an acrylic polyol in which a fluorine compound containing a vinyl group such as tetrafluoroethylene and chlorotrifluoroethylene is blended is exemplified. .

  The vinyl monomer-modified polyol can be obtained by reacting the above-mentioned high molecular weight polyol with a vinyl monomer.

  These high molecular weight polyols can be used alone or in combination of two or more.

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

  As the polyol component, preferably, a high molecular weight polyol, more preferably, a polyester polyol or an acrylic polyol is used.

  Examples of the polyamine component include an aromatic polyamine, an araliphatic polyamine, an alicyclic polyamine, an aliphatic polyamine, an amino alcohol, a primary amino group, or an alkoxy having a primary amino group and a secondary amino group. Examples include silyl compounds and polyoxyethylene group-containing polyamines.

  Examples of the aromatic polyamine include 4,4'-diphenylmethanediamine and tolylenediamine.

  Examples of the araliphatic polyamine include 1,3- or 1,4-xylylenediamine or a mixture thereof.

  Examples of the alicyclic polyamine include 3-aminomethyl-3,5,5-trimethylcyclohexylamine (alias: isophoronediamine), 4,4′-dicyclohexylmethanediamine, and 2,5 (2,6) -bis ( Aminomethyl) bicyclo [2.2.1] heptane, 1,4-cyclohexanediamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, bis- (4-aminocyclohexyl) methane, diaminocyclohexane , 3,9-bis (3-aminopropyl) -2,4,8,10-tetraoxaspiro [5.5] undecane, 1,3- and 1,4-bis (aminomethyl) cyclohexane and mixtures thereof And the like.

  Examples of the aliphatic polyamine include ethylenediamine, propylenediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexamethylenediamine, and hydrazine (including hydrates. ), Diethylenetriamine, triethylenetetramine, tetraethylenepentamine, 1,2-diaminoethane, 1,2-diaminopropane, 1,3-diaminopentane, and the like.

  Examples of the amino alcohol include N- (2-aminoethyl) ethanolamine.

  Examples of the alkoxysilyl compound having a primary amino group or a primary amino group and a secondary amino group include, for example, γ-aminopropyltriethoxysilane and N-phenyl-γ-aminopropyltrimethoxysilane. Examples thereof include an alkoxysilyl group-containing monoamine, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, and N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane.

  Examples of the polyoxyethylene group-containing polyamine include polyoxyalkylene ether diamines such as polyoxyethylene ether diamine. More specifically, for example, PEG # 1000 diamine manufactured by NOF Corporation, Jeffamine ED-2003, EDR-148, XTJ-512 manufactured by Huntsman and the like can be mentioned.

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

  In the present invention, if necessary, known additives, for example, a plasticizer, an antiblocking agent, a heat stabilizer, a light stabilizer, an antioxidant, a release agent, and a catalyst (such as the urethane-forming catalyst described above) Further, pigments, dyes, lubricants, fillers, hydrolysis inhibitors and the like can be added. These additives may be added at the time of synthesis of each component, or may be added at the time of mixing and dissolving each component, or may be added after the synthesis.

  The polyurethane resin of the present invention can be widely used in various industrial fields, for example, as paints, adhesives, elastomers, sealants, foams, and the like.

  When the polyurethane resin of the present invention is used, for example, as a paint or an adhesive, the polyurethane resin of the present invention is prepared by using the above-mentioned polyisocyanate composition as a curing agent and the above-mentioned active hydrogen compound as a main component, and using them. It is prepared as a two-part curable polyurethane resin that is sometimes blended.

  The mixing ratio of the polyisocyanate composition and the active hydrogen compound is, for example, 0.5 as an equivalent ratio (NCO / active hydrogen group) of the isocyanate group in the polyisocyanate composition to the active hydrogen group in the active hydrogen compound. To 1.5, preferably 0.8 to 1.2.

  The two-part curable polyurethane resin is preferably used as a two-part curable paint and / or a two-part curable adhesive. Specifically, first, the active hydrogen compound is prepared, and separately from the active hydrogen compound. , A polyisocyanate composition is prepared, and immediately before use, an active hydrogen compound and a polyisocyanate composition are mixed to prepare a two-part curable polyurethane resin, and the two-part curable polyurethane resin is coated on an object to be coated. Or apply to the adherend.

  In the case where the polyurethane resin of the present invention is produced as a two-component curable polyurethane resin, if necessary, further, a known additive, for example, as a coating composition, a coloring pigment, a dye, an ultraviolet absorber, As an adhesive composition such as a curing accelerator, a light stabilizer, and a matting agent, an oxygen acid of phosphorus or a derivative thereof or a silane coupling agent for improving adhesion of a coating film may be blended in an appropriate ratio. Can be.

  Color pigments, as dyes, for example, carbon black having good weather resistance, inorganic pigments such as titanium oxide, for example, organic pigments such as phthalocyanine blue, phthalocyanine green, quinacridone red, indanthrene orange, isoindolinone yellow, Dyes and the like.

  Examples of the ultraviolet absorber include benzophenone-based, benzotriazole-based, triazine-based, and cyanoacrylate-based ultraviolet absorbers, and more specifically, tinuvin 213, tinuvin 234, tinuvin 326, and tinuvin 571 (hereinafter, chivain 571). -Japan Co., trade name).

  Examples of the curing accelerator include dibutyltin dilaurate.

  As the light stabilizer, for example, hindered amine light stabilizers (for example, ADK STAB LA62, ADK STAB LA67 (all, manufactured by Adeka Argus Chemical Co., Ltd., trade name)), Tinuvin 765, Tinuvin 144, Tinuvin 770, Tinuvin 622 (all, Ciba. Japan Co., Ltd., trade name), and blend-based light stabilizers (for example, Tinuvin B75, Tinuvin PUR866 (all, Ciba Japan Co., trade name) and the like).

  Examples of the matting agent include ultrafine synthetic silica. By adding a matting agent, an elegant semi-gloss, matte finish coating film can be formed.

  In the oxygen acid of phosphorus or a derivative thereof, the oxygen acid of phosphorus includes, for example, phosphoric acids such as hypophosphorous acid, phosphorous acid, orthophosphoric acid, hypophosphoric acid, for example, metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid And condensed phosphoric acids such as acid and ultraphosphoric acid.

  Derivatives of oxygen acids of phosphorus include, for example, phosphates such as sodium and potassium or condensed phosphates, for example, monomethyl orthophosphate, monoethyl orthophosphate, monopropyl orthophosphate, monobutyl orthophosphate, monobutyl orthophosphate, Monoesters such as 2-ethylhexyl, monophenyl orthophosphate, monomethyl phosphite, monoethyl phosphite, monopropyl phosphite, monobutyl phosphite, mono-2-ethylhexyl phosphite, and monophenyl phosphite; For example, di-2-ethylhexyl orthophosphate, diphenyl orthophosphate, trimethyl orthophosphate, triethyl orthophosphate, tripropyl orthophosphate, tributyl orthophosphate, tri-2-ethylhexyl orthophosphate, triphenyl orthophosphate, diphenyl phosphite Chill, diethyl phosphite, dipropyl phosphite, dibutyl phosphite, di-2-ethylhexyl phosphite, diphenyl phosphite, trimethyl phosphite, triethyl phosphite, tripropyl phosphite, phosphorous acid Examples include di- and triesters such as tributyl, tri-2-ethylhexyl phosphite, and triphenyl phosphite, and mono-, di-, and triesters obtained from condensed phosphoric acid and alcohols.

  As the oxygen acid of phosphorus or a derivative thereof, the oxygen acid of various phosphorus or a derivative thereof described above can be used alone or in combination of two or more.

The silane coupling agent has, for example, the structural formula R—Si≡ (X) ₃ or R—Si≡ (R ′) (X) ₂ (where R is a vinyl group, an epoxy group, an amino group, an imino group, An organic group having an isocyanate group or a mercapto group, R ′ represents a lower alkyl group having 1 to 4 carbon atoms, and X represents a methoxy group, an ethoxy group or a chlorine atom.

  As the silane coupling agent, specifically, for example, chlorosilanes such as vinyltrichlorosilane, for example, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxy Epoxy silanes such as cyclohexyl) ethyltrimethoxysilane and di (γ-glycidoxypropyl) dimethoxysilane, for example, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, Aminosilanes such as N-β- (aminoethyl) -γ-propylmethyldimethoxysilane, n- (dimethoxymethylsilylpropyl) ethylenediamine, n- (triethoxysilylpropyl) ethylenediamine, N-phenyl-γ-aminopropyltrimethoxysilane For example, Vinylsilane such as Le triethoxysilane, for example, .gamma.-isocyanatopropyltrimethoxysilane, such as isocyanatosilanes such as .gamma.-isocyanatopropyltriethoxysilane and the like.

  As the silane coupling agent, the various silane coupling agents described above can be used alone or in combination.

  These additives may be previously added to the polyisocyanate composition and / or the active hydrogen compound, or may be added to the two-part curable polyurethane resin after the addition of the polyisocyanate composition and the active hydrogen compound. it can.

  According to the polyurethane resin of the present invention produced as a two-component curable polyurethane resin, a coating film having excellent mechanical properties can be obtained.

  The two-component curable polyurethane resin is not particularly limited with respect to the object to be coated or the object to be coated, for example, spray coating, air spray coating, brushing, dipping, a roll coater, a flow coater, or any arbitrary one. It can be painted by a painting method.

  The object to be coated is not particularly limited and includes, for example, inorganic substances such as concrete, natural stone, and glass; for example, metals such as iron, stainless steel, aluminum, copper, brass, and titanium; for example, plastics, rubber, and adhesives. And organic substances such as wood.

  The adherend is not particularly limited, and includes, for example, various building materials and various laminated films.

  More specifically, examples include packaging materials such as plastic films, metal foils, and metallized films, and civil engineering materials such as FRP and steel.

  In addition, the two-component curable polyurethane resin is, in addition to the two-component curable paint and / or the two-component curable adhesive described above, for example, a polyurethane foam, a sealant and a cosmetic, an electronic information material, a microcapsule used for stationery, and the like. It can also be used for raw materials.

  Further, the polyurethane resin of the present invention is produced by a polymerization method such as bulk polymerization or solution polymerization, for example, in applications such as elastomers, in addition to being produced as a two-part curable polyurethane resin.

  In the bulk polymerization, for example, while stirring the polyisocyanate composition under a nitrogen stream, an active hydrogen compound is added thereto, and the reaction temperature is 50 to 250 ° C, more preferably 50 to 200 ° C, and 0.5 to 500 ° C. Let react for about 15 hours.

  In the solution polymerization, a polyisocyanate composition and an active hydrogen compound are added to the above organic solvent, and the reaction is carried out at a reaction temperature of 50 to 120 ° C, more preferably 50 to 100 ° C, for about 0.5 to 15 hours.

  Further, in the polymerization reaction, if necessary, for example, the above-mentioned known urethanization catalyst such as an amine or an organometallic compound may be added, and the (unreacted) polyisocyanate composition may be added. For example, it may be removed by a known removing means such as distillation or extraction.

  In the bulk polymerization and the solution polymerization, for example, the polyisocyanate composition and the active hydrogen compound are converted into an equivalent ratio of an isocyanate group in the polyisocyanate composition to an active hydrogen group (hydroxyl group, amino group) in the active hydrogen compound (NCO / activity (Hydrogen group) is, for example, 0.75 to 1.3, preferably 0.9 to 1.1.

  When the polymerization reaction is carried out more industrially, the polyurethane resin can be obtained by a known method such as a one-shot method and a prepolymer method, depending on the use. In addition, the polyurethane resin can be obtained as, for example, an aqueous dispersion (PUD) by another method.

  In the one-shot method, for example, an equivalent ratio of an isocyanate group in a polyisocyanate composition to an active hydrogen group (hydroxyl group, amino group) in an active hydrogen compound (NCO / active hydrogen group) ) Is, for example, from 0.75 to 1.3, preferably from 0.9 to 1.1, and then formulated (mixed), for example, at room temperature to 250 ° C, preferably at room temperature to 200 ° C. For example, the curing reaction is performed for 5 minutes to 72 hours, preferably 4 to 24 hours. The curing temperature may be a constant temperature, or the temperature may be raised or cooled stepwise.

  In the prepolymer method, for example, first, an isocyanate composition is reacted with a part of an active hydrogen compound (preferably a high molecular weight polyol) to synthesize an isocyanate group-terminated prepolymer having an isocyanate group at a molecular terminal. . Next, the obtained isocyanate group-terminated prepolymer is reacted with the remainder of the active hydrogen compound (preferably, a low molecular weight polyol and / or polyamine component) to cause a curing reaction. In the prepolymer method, the remainder of the active hydrogen compound is used as a chain extender.

  In order to synthesize an isocyanate group-terminated prepolymer, the polyisocyanate composition and a part of the active hydrogen compound are combined with an equivalent ratio of an isocyanate group in the polyisocyanate composition to an active hydrogen group in a part of the active hydrogen compound (NCO / Active hydrogen group) is, for example, 1.1 to 20, preferably 1.3 to 10, more preferably 1.3 to 6, and is mixed (mixed) in a reaction vessel. The reaction is performed at room temperature to 150 ° C, preferably 50 to 120 ° C, for example, for 0.5 to 18 hours, preferably 2 to 10 hours. In this reaction, if necessary, the above-mentioned urethanization catalyst may be added.After the reaction is completed, if necessary, unreacted polyisocyanate composition may be subjected to, for example, distillation or extraction. It can also be removed by known removal means such as.

  Next, to react the obtained isocyanate group-terminated prepolymer with the remaining active hydrogen compound, the isocyanate group-terminated prepolymer and the remaining active hydrogen compound are reacted with the active hydrogen group in the remaining active hydrogen compound. Formulated (mixed) such that the equivalent ratio of isocyanate groups (NCO / active hydrogen groups) in the isocyanate group-terminated prepolymer is, for example, 0.75 to 1.3, preferably 0.9 to 1.1. For example, a curing reaction is performed at room temperature to 250 ° C., preferably at room temperature to 200 ° C., for example, for 5 minutes to 72 hours, preferably 1 to 24 hours.

  In order to obtain a polyurethane resin as an aqueous dispersion, for example, first, an activity including a polyisocyanate composition and an active hydrogen compound having a hydrophilic group described below (hereinafter, abbreviated as a hydrophilic group-containing active hydrogen compound). By reacting with a hydrogen compound, an isocyanate group-terminated prepolymer is obtained.

  Next, the obtained isocyanate group-terminated prepolymer and the chain extender are reacted and dispersed in water. Thereby, an aqueous polyurethane resin in which the isocyanate group-terminated prepolymer is chain-extended by the chain extender can be obtained as an internal emulsion type aqueous dispersion.

  In order to react the isocyanate group-terminated prepolymer with the chain extender in water, for example, first, the isocyanate group-terminated prepolymer is added to water to disperse the isocyanate group-terminated prepolymer. Next, a chain extender is added thereto to extend the chain of the isocyanate group-terminated prepolymer.

  The hydrophilic group-containing active hydrogen compound is a compound having both a hydrophilic group and an active hydrogen group. Examples of the hydrophilic group include an anionic group (for example, a carboxyl group), a cationic group, and a nonionic group (for example, , Polyoxyethylene groups, etc.). More specifically, examples of the active hydrogen compound having a hydrophilic group include an active hydrogen compound having a carboxylic acid group and an active hydrogen compound having a polyoxyethylene group.

  Examples of the carboxylic acid group-containing active hydrogen compound include 2,2-dimethylolacetic acid, 2,2-dimethylollactic acid, 2,2-dimethylolpropionic acid, 2,2-dimethylolbutanoic acid and 2,2-dimethylolbutyric acid. And dihydroxycarboxylic acids such as 2,2-dimethylolvaleric acid, for example, diaminocarboxylic acids such as lysine and arginine, and metal salts and ammonium salts thereof.

  The polyoxyethylene group-containing active hydrogen compound is a compound containing a polyoxyethylene group in a main chain or a side chain and having two or more active hydrogen groups, such as polyethylene glycol and a polyoxyethylene side chain-containing polyol ( Compounds having a polyoxyethylene group in the side chain and having two or more active hydrogen groups).

  These hydrophilic hydrogen compounds having a hydrophilic group can be used alone or in combination of two or more.

  As the chain extender, for example, low molecular weight polyols such as the above-mentioned dihydric alcohols and the above-mentioned trihydric alcohols, for example, diamines such as alicyclic diamines and aliphatic diamines can be used.

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

  As described above, when an active hydrogen compound containing a hydrophilic group-containing active hydrogen compound is used, the hydrophilic group is neutralized with a known neutralizing agent, if necessary.

  When a hydrophilic group-containing active hydrogen compound is not used as the active hydrogen compound, for example, by emulsifying with a known surfactant, an aqueous emulsion of an external emulsification type can be obtained.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but these do not limit the present invention at all. Note that “parts” and “%” are based on mass unless otherwise specified. The measurement methods used in the production examples and the like are shown below.
<Isocyanate group concentration (unit: mass%)>
The isocyanate group concentration of the polyisocyanate composition was measured by an n-dibutylamine method according to JIS K-1556 using a potentiometric titrator.
<Viscosity (unit: mPa · s)>
Using an E-type viscometer TV-30 manufactured by Toki Sangyo Co., Ltd. (rotor: 1 ° 34 ′ × R24, rotation speed: selected from the range of 0.1 to 10 rpm so that the measurement range is 20 to 80%). And the viscosity at 25 ° C. were measured.
<Average number of isocyanate functional groups>
The average number of isocyanate functional groups was calculated from the isocyanate group concentration and solid content concentration (NV) of the polyisocyanate composition, and the number average molecular weight of gel permeation chromatography measured using the following apparatus and conditions by the following formula. .

Average number of isocyanate functional groups = A / B × C / 42.02
(In the formula, A indicates an isocyanate group concentration, B indicates a solid content concentration, and C indicates a number average molecular weight.)
Equipment: HLC-8220GPC (Tosoh)
Column: TSKgelG1000HXL, TSKgelG2000HXL, and TSKgelG3000HXL (manufactured by Tosoh) connected in series Detector: Differential refractometer Measurement conditions Injection volume: 100 μL
Eluent: tetrahydrofuran flow rate: 0.8 mL / min
Temperature: 40 ° C
Calibration curve: standard polyethylene oxide in the range of 106 to 22450 (manufactured by Tosoh, trade name: TSK standard polyethylene oxide)
<Hydroxyl value (unit: mgKOH / g)>
The hydroxyl value of the polyol was measured by the method A (acetylation method) based on JIS K1557-1.

[Production of pentamethylene diisocyanate]
Preparation Example 1 (Production of pentamethylene diisocyanate)
2000 parts by mass of o-dichlorobenzene was charged into a jacketed pressurized reactor equipped with an electromagnetic induction stirrer, an automatic pressure regulating valve, a thermometer, a nitrogen introduction line, a phosgene introduction line, a condenser, and a raw material feed pump. Next, 2300 parts by mass of phosgene was added from the phosgene introduction line, and stirring was started. Cold water was passed through the reactor jacket to keep the internal temperature at about 10 ° C. A solution obtained by dissolving 400 parts by mass of pentamethylenediamine (purity: 99.9% by mass) in 2600 parts by mass of o-dichlorobenzene was fed over 60 minutes by a feed pump, and cooled at 30 ° C. or less under normal pressure. Phosgenation was started. After the feed was completed, the inside of the pressurized reactor became a light brownish white slurry-like liquid.

  Next, the internal liquid of the reactor was pressurized to 0.25 MPa while gradually raising the temperature to 160 ° C., and further subjected to thermal phosgenation at a pressure of 0.25 MPa and a reaction temperature of 160 ° C. for 90 minutes. During the thermal phosgenation, 1100 parts by mass of phosgene was further added. In the course of the thermal phosgenation, the liquid in the pressure reactor became a light brown clear solution. After the completion of the thermal phosgenation, nitrogen gas was passed at 100 L / hour at 100 to 140 ° C. to degas.

  Then, after o-dichlorobenzene was distilled off under reduced pressure, pentamethylene diisocyanate was also distilled off under reduced pressure. Next, pentamethylene diisocyanate was charged into a four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube, and was heated at 190 ° C. for 3 hours under normal pressure while introducing nitrogen. Then, the heat-treated pentamethylene diisocyanate was charged into a glass flask, and a distillation tube filled with 4 elements of a filler (manufactured by Sumitomo Heavy Industries, Ltd., trade name: Sumitomo / Sulzer Lab Packing EX type), reflux ratio Using a distillation column equipped with an adjustment timer (manufactured by Shibata Kagaku Co., trade name: distillation head K type) and a rectifying device equipped with a cooler, further reflux at 127 to 132 ° C and 2.7 KPa. While rectifying the product, pentamethylene diisocyanate having a purity of 99.9% by mass (hereinafter abbreviated as PDI) was obtained. The concentration of hydrolyzable chlorine in pentamethylene diisocyanate was 0.004%.

[Production of polyisocyanate composition]
Reference Example 1 (Production of polyisocyanate composition (a))
Ditrimethylolpropane (hereinafter abbreviated as Di-TMP) and trimethylolpropane (hereinafter abbreviated as TMP) are placed in a four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube. Di-TMP was inserted in an amount of 8.9 parts by mass and TMP in an amount of 91.1 parts by mass so that Di-TMP was 5 mol% and TMP was 95 mol% with respect to the total amount thereof, and nitrogen was introduced. The mixture was heated and mixed at 130 ° C. for 3 hours under normal pressure to obtain a polyol (a).

  Next, the urethanization reaction was carried out at an equivalent ratio (NCO / OH) of the isocyanate group in the PDI to the hydroxyl group of the polyol of 5.5. That is, 21.7 parts by mass of the polyol (a) was charged into the dropping funnel and heated by the ribbon heater. Next, 200 parts by mass of PDI was charged into a four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube, and the temperature was raised to 95 ° C. while stirring under a nitrogen atmosphere. Next, the molten polyol (a) was added dropwise over about 60 minutes. Thereafter, the urethanization reaction was continued for about 3 hours until the isocyanate group concentration reached the calculated value. The obtained reaction solution is passed through a thin film distillation apparatus (degree of vacuum: 50 Pa, temperature: 130 ° C.) to remove unreacted PDI, and further, ethyl acetate is added so that the solid content concentration becomes 75% by mass. A composition (a) was obtained.

  The obtained polyisocyanate composition (a) had a solid content concentration of 75.2%, an isocyanate group concentration of 13.6%, a viscosity of 340 mPa · s / 25 ° C., and an average number of isocyanate groups of 4.0.

Example 2 (Production of polyisocyanate composition (b))
A polyol (b) was obtained in the same manner as in Reference Example 1, except that the content of Di-TMP and TMP was set to the values shown in Table 1. Next, a polyisocyanate composition (b) was obtained in the same manner as in Example 1, except that 25.9 parts by mass of the polyol (b) was charged instead of the polyol (a). Table 1 shows the solid content concentration, isocyanate group concentration, viscosity, and average number of isocyanate groups.

Example 3 (Production of polyisocyanate composition (c))
A polyol (c) was obtained in the same manner as in Reference Example 1 , except that the contents of Di-TMP and TMP were set to the values shown in Table 1. Next, a polyisocyanate composition (c) was obtained in the same manner as in Reference Example 1 , except that 29.2 parts by mass of the polyol (c) was charged instead of the polyol (a). Table 1 shows the solid content concentration, isocyanate group concentration, viscosity, and average number of isocyanate groups.

Reference Example 4 (Production of polyisocyanate composition (d))
A polyisocyanate composition (d) was obtained in the same manner as in Reference Example 1 , except that 29.5 parts by mass of Di-TMP was used instead of the polyol (a). Table 1 shows the solid content concentration, isocyanate group concentration, viscosity, and average number of isocyanate groups.

Reference Example 5 (Production of polyisocyanate composition (e))
Same as Reference Example 1 except that 19.8 parts by mass of the polyol (a) was charged, and 200 parts by mass of hexamethylene diisocyanate (Takenate 700 manufactured by Mitsui Chemicals, hereinafter abbreviated as HDI) was charged instead of PDI. By the method, a polyisocyanate composition (e) was obtained. Table 1 shows the isocyanate group concentration, viscosity, solid content concentration, and average number of isocyanate groups.

Comparative Example 1 (Production of polyisocyanate composition (f))
A polyisocyanate composition (f) was obtained in the same manner as in Reference Example 1 , except that 21.1 parts by mass of TMP was used instead of the polyol (a). Table 1 shows the solid content concentration, isocyanate group concentration, viscosity, and average number of isocyanate groups.

Comparative Example 2 (Production of polyisocyanate composition (g))
Diglycerin (hereinafter abbreviated as DGly) and TMP were placed in a four-neck flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube. 95.9 parts by mass of DGly and 4.1 parts by mass of TMP were added so that the content was 5 mol%, and the mixture was heated and mixed at 80 ° C. for 3 hours under a normal pressure while introducing nitrogen to obtain polyol (d). Got.

  Next, urethanization reaction was carried out at an equivalent ratio (NCO / OH) of the isocyanate group in the PDI to the hydroxyl group of the polyol of 5.5. That is, 19.7 parts by mass of the polyol (d) was charged into the dropping funnel and heated by the ribbon heater. Next, 200 parts by mass of PDI was charged into a four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube, and heated to 95 ° C. while stirring under a nitrogen atmosphere. Next, the molten polyol (d) was added dropwise over about 60 minutes. Immediately after the dropwise addition, insolubles were generated, and the urethanization reaction was continued for 5 hours after the completion of the dropwise addition, but the insolubles did not disappear. For this reason, it was difficult to remove the unreacted PDI by passing the solution through a thin-film distillation apparatus, so that a polyisocyanate composition could not be obtained.

Comparative Example 3 (Production of polyisocyanate composition (h))
The urethanization reaction was carried out at an equivalent ratio (NCO / OH) of the isocyanate group in PDI to the hydroxyl group of the polyol of 5.5. That is, 0.8 parts by mass of TMP was charged into the dropping funnel and heated by the ribbon heater. Next, 200 parts by mass of PDI was charged into a four-necked flask equipped with a stirrer, a thermometer, a reflux tube, and a nitrogen inlet tube, and heated to 95 ° C. while stirring under a nitrogen atmosphere. Next, 3.1 g of pentaerythritol (hereinafter abbreviated as PENT) was added 5 times at 10 minute intervals. Further, the melted TMP was dropped over about 60 minutes. Immediately after the addition of PENT, insolubles were generated, and the urethane reaction was continued for 5 hours after the completion of the dropping of TMP, but the insolubles did not disappear. For this reason, it was difficult to remove the unreacted PDI by passing the solution through a thin-film distillation apparatus, so that a polyisocyanate composition could not be obtained.

The details of the abbreviations in the table are described below.
PDI: Pentamethylene diisocyanate HDI: Hexamethylene diisocyanate Di-TMP: Ditrimethylolpropane TMP: Trimethylolpropane DGly: Diglycerin PENT: Pentaerythritol Synthesis Example 1 (Production of Polyol A)
In a four-necked flask equipped with a stirrer, a thermometer, a reflux cooling device, and a nitrogen inlet tube, 20 parts by mass of butyl acetate and 80 parts by mass of methyl isobutyl ketone were charged as organic solvents, and heated to 95 ° C. while purging with nitrogen. did. Next, 35 parts by mass of methyl methacrylate, 25 parts by mass of butyl acrylate, 11.5 parts of 2-hydroxyethyl methacrylate, 28.5 parts by mass of styrene, and tert- 0.4 parts by mass of butyl peroxy-2-ethylhexanoate (hereinafter abbreviated as PBO) was fed over 4 hours. One hour and two hours after the end of the feed, 0.2 parts by mass of PBO was added. After addition of PBO, the mixture was reacted for 2 hours to obtain polyol A. The hydroxyl value of polyol A was 25 mgKOH / g.

[Production of polyurethane resin]
Reference Example 6 (Production of polyurethane resin (A))
The polyol A as a main agent and the polyisocyanate composition (a) obtained in Reference Example 1 as a curing agent were prepared by using an equivalent ratio of an isocyanate group in the polyisocyanate composition to a hydroxyl group in the polyol A (NCO / OH). ) Is 1.0, and dibutyltin dilaurate of 50 ppm based on the solid content of the main agent and the curing agent as a catalyst, and butyl acetate such that the solid content concentration of the main agent and the curing agent is 40%. Was added and stirred at 23 ° C. for 180 seconds to obtain a reaction mixture.

  Next, this reaction mixture was applied to a steel plate (JIS, G, 3141 (SPCC, SB)) and a glass plate (JIS, R, 3202) and cured by heating at 80 ° C. for 30 minutes. Then, it was left still in a room at 23 ° C. and 50% RH for 7 days to obtain a polyurethane resin (A) having a thickness of about 20 μm.

  The sample coated on a steel plate to form a coating film was subjected to the Martens hardness, weight drop resistance (DuPont type), and cupping resistance tests described below, and the sample coated on a glass plate to form a coating film Was subjected to a solvent resistance test described below.

Examples 7 to 8, Reference Examples 9 to 10, and Comparative Example 4 (Production of polyurethane resins (B) to (F))
Polyurethane resins (B) to (F) were obtained in the same manner as in Reference Example 6 , except that the polyisocyanate compositions shown in Table 2 were used.

Physical property evaluation For each of the polyurethane resins obtained in Examples , Reference Examples and Comparative Examples, Martens hardness, weight drop resistance (DuPont type), cupping resistance, and solvent resistance were measured by the following methods. . Table 2 shows the results.
<Martens hardness (unit: N / mm ² )>
An indenter type: Triangular 115, a test mode: a load-unload test, a test force: 10.00 mN, using a micro-hardness tester (DUH-211 manufactured by Shimadzu Corporation) for the coating film in close contact with the test plate. The Martens hardness (HMT115) was measured under the conditions of a load speed of 3.0 mN / sec and a load holding time of 10 sec.
<Weight drop resistance (Dupont type) (unit: cm)>
JIS K 5600-5-3 6. The measurement was performed according to the DuPont method, with the shooting type and the cradle being 1/2 inch and the weight being 500 g.
<Cupping resistance (unit: mm)>
The cupping resistance was measured according to JIS K 5600-5-2.
<Solvent resistance (unit: times)>
A cotton swab sufficiently impregnated with the test liquid was placed on the coating film in close contact with the test plate, and reciprocated a distance of about 1 cm under a constant load. This operation was repeated, and the test was terminated when damage was observed in the coating film. One round trip was performed, and the number of times until damage was observed in the coating film was defined as solvent resistance. The test solution was ethyl acetate.

Claims (4)

A reaction product of an aliphatic polyisocyanate and a polyol containing ditrimethylolpropane,
The polyol comprises ditrimethylolpropane and trimethylolpropane,
A polyisocyanate composition, wherein the content of ditrimethylolpropane relative to the total amount of the polyol is from 50 mol% to 95 mol%.   The polyisocyanate composition according to claim 1, wherein the average number of isocyanate functional groups is 3 to 5.5.   The polyisocyanate composition according to claim 1, wherein the aliphatic polyisocyanate comprises pentamethylene diisocyanate.   A polyurethane resin obtained by reacting the polyisocyanate composition according to claim 1 with an active hydrogen compound.