Curing agent composition, polyurethane resin forming kit, polyurethane resin manufacturing method, and sealing material for membrane modules

Abstract

To provide a curing agent composition that offers excellent workability and anti-foaming properties when obtaining polyurethane resin, and that yields a cured product with excellent hardness. [Solution] A curing agent composition (B) comprising a castor oil-based polyol, a hydroxyl group-containing amine compound, sebaciac acid, and 2-octanol, wherein the sum of the concentrations of sebaciac acid and 2-octanol based on the weight of the curing agent composition (B) is 170 to 230 ppm, and the ratio of the concentration of sebaciac acid to the sum of the concentrations of 2-octanol and sebaciac acid (sebaciac acid / [2-octanol + sebaciac acid]) is 0.83 to 0.91.

Description

[Technical Field]

[0001] The present invention relates to a curing agent composition, a polyurethane resin forming kit, a method for producing polyurethane resin, and a sealing material for membrane modules. [Background technology]

[0002] Polyurethane resins used as sealing materials for hollow fiber type blood treatment devices or water purifiers are known to be obtained by the reaction of a polyisocyanate prepolymer (main component) and a polyol (curing agent). As a curing agent, those containing castor oil-based polyols are known (for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2023 / 058757 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] When obtaining polyurethane resin using the curing agent described in Patent Document 1, there was room for improvement in terms of workability, foam suppression, and hardness of the cured product.

[0005] The present invention aims to solve the above problems and provide a curing agent composition that offers excellent workability and foam suppression when obtaining polyurethane resin, and that can produce a cured product with excellent hardness. [Means for solving the problem]

[0006] The inventors of this invention arrived at this present invention after diligent research. The present invention relates to a curing agent composition (B) comprising a castor oil-based polyol, a hydroxyl group-containing amine compound, sebacic acid, and 2-octanol, wherein the sum of the concentrations of sebacic acid and 2-octanol based on the weight of the curing agent composition (B) is 170 to 230 ppm, and the ratio of the concentration of sebacic acid to the sum of the concentrations of 2-octanol and sebacic acid (sebacic acid / [2-octanol + sebacic acid]) is 0.83 to 0.91; curing agent composition (B); the curing agent composition A polyurethane resin forming kit comprising (B) and a polyisocyanate prepolymer (A) contained in a container, wherein the polyisocyanate prepolymer (A) contains a reaction product of diphenylmethane diisocyanate (a1-1) and / or a modified diphenylmethane diisocyanate (a1-2) and an active hydrogen-containing compound (a2), and the water content in the container is 1.05 g / m² relative to the interface area between the polyisocyanate prepolymer (A) and the voids. 2 The following is a polyurethane resin forming kit; a method for producing a polyurethane resin, comprising reacting the curing agent composition (B) with a polyisocyanate prepolymer (A) contained in a container, wherein the polyisocyanate prepolymer (A) contains the reaction product of diphenylmethane diisocyanate (a1-1) and / or a modified diphenylmethane diisocyanate (a1-2) and an active hydrogen-containing compound (a2), and the water content in the container is 1.05 g / m² relative to the interface area between the polyisocyanate prepolymer (A) and the voids. 2 The present invention relates to a method for producing a polyurethane resin, comprising mixing and reacting the curing agent composition (B) and the polyisocyanate prepolymer (A) at 25 to 45°C; and a sealing material for a membrane module, wherein the polyurethane resin is obtained by reacting the curing agent composition (B) and the polyisocyanate prepolymer (A) using the polyurethane resin forming kit. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a curing agent composition that is excellent in workability and foam suppression properties when obtaining a polyurethane resin and can obtain a cured product excellent in hardness.

Mode for Carrying Out the Invention

[0008] The curing agent composition (B) of the present invention is a curing agent composition (B) containing a castor oil-based polyol, a hydroxyl group-containing amine compound, sebacic acid, and 2-octanol, wherein the total concentration of sebacic acid and the concentration of 2-octanol based on the weight of the curing agent composition (B) is 170 to 230 ppm, and the ratio of the concentration of sebacic acid to the total concentration of 2-octanol and sebacic acid (sebacic acid / [2-octanol + sebacic acid]) is 0.83 to 0.91.

[0009] Examples of the castor oil-based polyol include castor oil, partially dehydrated castor oil, partially acylated castor oil, low molecular polyols, or castor oil fatty acid esters obtained by transesterification of polyoxyalkylene polyols and castor oil or esterification reaction with castor oil fatty acids.

[0010] Examples of the hydroxyl group-containing amine compound include amine-based polyols. For example, propylene oxide and / or ethylene oxide adducts of ethylenediamine, N,N,N’,N’-tetrakis(2-hydroxypropyl)-ethylenediamine, N,N,N’,N”,N”-pentakis(2-hydroxypropyl)-diethylenetriamine, triethanolamine, oxyalkylated products of N,N-dimethylpropylenediamine, oxyalkylated products of N,N-dimethyldipropylenetriamine (described in JP-A-11-335436), and oxyalkylated products of N-aminoalkylimidazole (described in JP-A-11-322881). Among these, the propylene oxide adduct of ethylenediamine is preferred.

[0011] Sebacic acid is a dicarboxylic acid with 10 carbon atoms represented by HOOC-(CH2)8-COOH, and for example, those manufactured by Ogura Synthetic Industry Co., Ltd. can be used.

[0012] 2-Octanol is a secondary alcohol represented by CH3-CH(OH)-(CH2)5-CH3, and reagent-grade 2-octanol manufactured by Fujifilm Wako Pure Chemical Corporation or Tokyo Chemical Industry Co., Ltd. can be used.

[0013] The total concentration of sebacic acid and 2-octanol based on the weight of the curing agent composition (B) is 170 to 230 ppm. The above total concentration is preferably 180 ppm or more, 190 ppm or more, and preferably 220 ppm or less, 210 ppm or less, 200 ppm or less.

[0014] The ratio of the concentration of sebacic acid to the total concentration of 2-octanol and sebacic acid in the curing agent composition (B) (sebacic acid / [2-octanol + sebacic acid]) is 0.83 to 0.91. The above ratio is preferably 0.84 or more, 0.86 or more, and preferably 0.90 or less, 0.88 or less.

[0015] Since the curing agent composition (B) contains a predetermined amount of 2-octanol and sebacic acid, the initial mixing viscosity in the mixture obtained by mixing the curing agent composition (B) with the polyisocyanate prepolymer (A) becomes appropriately low, and the gelation time can be adjusted to a range suitable for the process. Moreover, the cured product of the said mixture becomes excellent in hardness.

[0016] 2-Octanol and sebacic acid may be components derived from castor oil (components contained in castor oil as a mixture), or may be components added to the curing agent composition (B) separately from castor oil.

[0017] The concentration of sebacic acid based on the weight of the curing agent composition (B) is preferably 150 to 200 ppm. Furthermore, the concentration of sebacic acid is preferably 160 ppm or higher, 170 ppm or higher, and preferably 190 ppm or lower, 180 ppm or lower.

[0018] The concentration of 2-octanol based on the weight of the curing agent composition (B) is preferably 20 to 30 ppm. Furthermore, the concentration of 2-octanol is preferably 22 ppm or higher, 24 ppm or higher, and preferably 28 ppm or lower, 26 ppm or lower.

[0019] The concentrations of sebaciic acid and 2-octanol based on the weight of the curing agent composition (B) can be quantified by gas chromatography-mass spectrometry (GC-MS). Sebatic acid can be quantified by GC-MS after methyl esterification of the curing agent composition (B) in methanol to obtain dimethyl sebacate. 2-octanol can be quantified by adding 1-nonanol as an internal standard and analyzing the peak area ratio using GC-MS.

[0020] The curing agent composition (B) preferably has a viscosity of 500 to 1500 mPa·s at 25°C. Viscosity at 25°C can be defined as the viscosity measured at 25°C using a rotational viscometer (for example, TVB-10M manufactured by Toki Sangyo Co., Ltd.) at a rotational speed of 60 rpm.

[0021] The curing agent composition (B) may further contain other polyols. Examples of other polyols include low molecular weight polyols, polyether polyols, polyester polyols, polylactone polyols, and polyolefin polyols.

[0022] Examples of low molecular weight polyols include divalent polyols such as ethylene glycol, diethylene glycol, propylene glycol, 1,2-, 1,3- or 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, neopentyl glycol, and hydrogenated bisphenol A, as well as trivalent to octavalent polyols such as glycerin, trimethylolpropane, hexanetriol, pentaerythritol, sorbitol, and sucrose. The molecular weight or number-average molecular weight of the low molecular weight polyol is preferably 50 or more and 200 or less.

[0023] Examples of polyether-based polyols include adducts of the above-mentioned low-molecular-weight polyols with alkylene oxides (alkylene oxides with 2 to 8 carbon atoms, such as ethylene oxide, propylene oxide, and butylene oxide), and ring-opening polymers of alkylene oxides. Specifically, examples include polypropylene glycol, polyethylene glycol, polytetramethylene ether glycol, or copolymers of ethylene oxide and propylene oxide.

[0024] The number-average molecular weight of the polyether polyol is preferably between 200 and 7000, and more preferably between 500 and 5000.

[0025] Examples of polyester polyols include those obtained by condensation polymerization of polycarboxylic acids and polyols. Examples of polycarboxylic acids used in polyester polyols include adipic acid, azelaic acid, dodecanediic acid, maleic acid, fumaric acid, itaconic acid, dimerized linoleic acid, phthalic acid, isophthalic acid, terephthalic acid, and other aliphatic saturated and unsaturated polycarboxylic acids, as well as aromatic polycarboxylic acids. Examples of polyols used in polyester polyols include the low molecular weight polyols and polyether polyols mentioned above.

[0026] Examples of polylactone-based polyols include polyols obtained by addition polymerization of glycols or triols with ε-caprolactone, α-methyl-ε-caprolactone, ε-methyl-ε-caprolactone, and β-methyl-δ-valerolactone in the presence of catalysts such as organometallic compounds, metal chelate compounds, and fatty acid metal acyl compounds.

[0027] Examples of polyolefin-based polyols include polybutadiene, or polybutadiene-based polyols obtained by introducing hydroxyl groups to the terminals of a copolymer of butadiene and styrene or acrylonitrile. Other examples include polyether ester polyols obtained by adding alkylene oxides, such as ethylene oxide or propylene oxide, to polyesters having carboxyl groups and hydroxyl groups at their terminals.

[0028] The polyurethane resin forming kit of the present invention comprises the curing agent composition (B) and a polyisocyanate prepolymer (A) contained in a container, wherein the polyisocyanate prepolymer (A) contains a reaction product of diphenylmethane diisocyanate (a1-1) and / or a modified diphenylmethane diisocyanate (a1-2) and an active hydrogen-containing compound (a2), and the water content in the container is 1.05 g / m² relative to the interface area between the polyisocyanate prepolymer (A) and the voids. 2 The following is a polyurethane resin molding kit.

[0029] The polyurethane resin forming kit comprises a polyisocyanate prepolymer (A) contained in a container, which is used in combination with the curing agent composition (B) of the present invention. The following describes this polyisocyanate prepolymer (A).

[0030] The polyisocyanate prepolymer (A) contains the reaction product of diphenylmethane diisocyanate (a1-1) and / or a modified diphenylmethane diisocyanate (a1-2) and an active hydrogen-containing compound (a2).

[0031] Diphenylmethane diisocyanates (a1) Diphenylmethane diisocyanates (a1) are diphenylmethane diisocyanate (a1-1), modified diphenylmethane diisocyanate (a1-2), or mixtures thereof.

[0032] Examples of diphenylmethane diisocyanates (a1-1) include 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, and mixtures of 2,4'-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate.

[0033] Examples of modified diphenylmethane diisocyanate (a1-2) include compounds obtained by modifying some or all of the isocyanate groups of diphenylmethane diisocyanate with carbodiimide groups, uretdione groups, uretoimine groups, urea groups, biuret groups, isocyanurate groups, etc. The modified diphenylmethane diisocyanate may be used individually or in combination of two or more types. The modified diphenylmethane diisocyanate (a1-2) may also be a carbodiimide modified version of the modified diphenylmethane diisocyanate.

[0034] Diphenylmethane diisocyanates (a1) may be a mixture of diphenylmethane diisocyanate (a1-1) and a modified diphenylmethane diisocyanate (a1-2).

[0035] Active hydrogen-containing compound (a2) The active hydrogen-containing compound (a2) may be a compound having two or more active hydrogen-containing groups per molecule, and examples of active hydrogen-containing groups include hydroxyl groups, amino groups, carboxyl groups, and thiol groups. The number of active hydrogen-containing groups per molecule of the active hydrogen-containing compound (a2) may be 20 or less, and may be 10 or less, 8 or less, 6 or less, 4 or less, or 3 or less.

[0036] Examples of active hydrogen-containing compounds (a2-1) having a hydroxyl group as an active hydrogen-containing group include polyols, such as castor oil polyols, low molecular weight polyols, polyether polyols, polyester polyols, polylactone polyols, and polyolefin polyols.

[0037] These polyols include the castor oil-based polyols contained in curing agent composition (B), and other polyols exemplified as other polyols that may be further included in curing agent composition (B). Therefore, a detailed explanation of these polyols is omitted.

[0038] Examples of active hydrogen-containing compounds (a2-2) having an amino group as an active hydrogen-containing group include primary monoamines [mono(cyclo)alkylamines with 1 to 20 carbon atoms (methylamine, ethylamine, butylamine, octylamine, dodecylamine, cyclohexylamine, etc.), aromatic and aromatic aliphatic monoamines with 6 to 12 carbon atoms (aniline, toluidine, benzylamine, etc.)]; polyamines having two or more active hydrogens [aliphatic diamines with 2 to 12 or more carbon atoms {alkylenediamines, e.g., ethylenediamine, propylenediamine, hexyl Shark ethylenediamine, and mono- or di-alkyl (1-4 carbon atoms) alkylenediamines (dimethylpropylenediamine, etc.), alicyclic diamines with 6-15 carbon atoms (1,4-diaminocyclohexane, isophoronediamine, and 4,4'-diaminocyclohexylmethane, etc.), aromatic diamines with 6-15 carbon atoms {m- or p-phenylenediamine, tolylenediamine, diethyltoluenediamine, 4,4'-diaminophenylmethane, and 2,2-bis(4,4'-diaminophenyl)propane, etc.}, aromatic aliphatic diamines with 8-15 carbon atoms ( (e.g., m- or p-xylylenediamine), heterocyclic polyamines with 4 to 10 carbon atoms {piperalidine, aminoalkyl (2 to 4 carbon atoms) piperazine (e.g., aminoethylpiperazine), aminoalkyl (2 to 4 carbon atoms) imidazole, etc.}, polyalkylene polyamines with 2 to 4 carbon atoms in the alkylene group {diethylenetriamine, dipropylenetriamine, triethylenetetramine, polyethyleneimine with a number-average molecular weight of 2,000 or less, and mono-, di- or tri-alkyl (1 to 4 carbon atoms) polyalkylene polyamines (e.g., dimethyldipropylene Examples include: diamines, etc.; mono- or di-alkanolamines with 2 to 4 carbon atoms in a hydroxyalkyl group (monoethanolamine, monoisopropanolamine, diethanolamine, and diisopropanolamine, etc.); polymers or oligomers with one or more amino groups and a number average molecular weight of 2,000 or less [aminoalkyl (2-4 carbon atoms) (meth)acrylate (co)polymers and polyether (poly)amines (polyoxypropylenediamine and polyoxypropylenetriamine, etc.)]; and mixtures of two or more of these.

[0039] Examples of active hydrogen-containing compounds (a2-3) having an amino group and a hydroxyl group as active hydrogen-containing groups include amine polyols. For example, a hydroxyoxyalkylated product (hydroxyalkyl group with 2 to 4 or more carbon atoms) of the active hydrogen-containing compound (a2-2) having an amino group as an active hydrogen-containing group can be used. As a specific example of an amine polyol, the amine polyol exemplified as the hydroxyl group-containing amine compound contained in the curing agent composition (B) can be used, so a detailed explanation is omitted.

[0040] Examples of active hydrogen-containing compounds (a2-4) having a carboxyl group as an active hydrogen-containing group include aliphatic polycarboxylic acids having 2 to 36 carbon atoms (such as succinic acid, glutaric acid, adipic acid, sebacic acid, maleic acid, fumaric acid, and dimerized linoleic acid), aromatic polycarboxylic acids having 8 to 15 carbon atoms (such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, and pyromellitic acid), unsaturated carboxylic acid polymers [such as (meth)acrylic acid (co)polymers with a number-average molecular weight of 2,000 or less], and mixtures of two or more of these.

[0041] Examples of active hydrogen-containing compounds (a2-5) having a thiol group as an active hydrogen-containing group include 2-6 or more carbon-18 valent polythiols (ethanedithiol, propanedithiol, 1,3- or 1,4-butanedithiol, 1,6-hexanedithiol, 3-methyl-1,5-pentanedithiol, etc.).

[0042] Of these, preferred are active hydrogen-containing compounds having a hydroxyl group as an active hydrogen-containing group (a2-1), active hydrogen-containing compounds having an amino group as an active hydrogen-containing group (a2-2), and active hydrogen-containing compounds having both an amino group and a hydroxyl group as active hydrogen-containing groups (a2-3). More preferred are castor oil-based polyols, low molecular weight polyols, polyether-based polyols, and amine-based polyols. Particularly preferred are polypropylene glycol, castor oil, partially dehydrated castor oil, N,N',N'-tetrakis(2-hydroxypropyl)-ethylenediamine, propylene oxide and ethylene oxide adducts of ethylenediamine.

[0043] The content of diphenylmethane diisocyanates (a1) in the raw materials of polyisocyanate prepolymer (A) may be 40% by weight or more, or 50% by weight or more, and 90% by weight or less, or 80% by weight or less, based on the total weight of the raw materials of polyisocyanate prepolymer (A).

[0044] The content of the active hydrogen-containing compound (a2) in the raw materials of the polyisocyanate prepolymer (A) may be 10% by weight or more, or 20% by weight or more, and 60% by weight or less, or 50% by weight or less, based on the total weight of the raw materials of the polyisocyanate prepolymer (A).

[0045] In the polyisocyanate prepolymer (A), the equivalent ratio (NCO group / active hydrogen-containing group) of the NCO group in the diphenylmethane diisocyanate to the active hydrogen-containing group in the active hydrogen-containing compound is usually 1.1 / 1 to 100 / 1, preferably 2 / 1 to 80 / 1, and more preferably 3 / 1 to 60 / 1. The NCO group content in the polyisocyanate prepolymer (A) is usually 3 to 35% by weight, preferably 5 to 30% by weight.

[0046] The polyisocyanate prepolymer (A) is contained in a container, which contains both the liquid component of the polyisocyanate prepolymer (A) and a gaseous component. The gaseous component exists in the voids within the container, excluding the liquid component.

[0047] The container material should be one that does not corrode, degrade, or dissolve due to the polyisocyanate prepolymer. For example, a metal can can be used. Examples of metal can materials include iron, stainless steel, and glass-lined steel.

[0048] In the container, the water content is 1.05 g / m² relative to the interface area between the polyisocyanate prepolymer (A) and the voids. 2 The following applies: This regulation specifies the standardized amount of moisture inside the container. If the amount of moisture is high relative to the surface area, the isocyanate component will react with the moisture while the polyisocyanate prepolymer (A) is stored inside the container, generating urea and carbon dioxide. This increases the internal pressure inside the container, causing gaseous components to dissolve into the polyisocyanate prepolymer. When polyurethane resin is manufactured using this polyisocyanate prepolymer, gaseous components dissolved in the polyisocyanate prepolymer may be released, causing bubbles to form in the polyurethane resin.

[0049] Therefore, in the polyisocyanate prepolymer (A) contained in the container, the water content relative to the interface area between the polyisocyanate prepolymer (A) and the voids inside the container is 1.05 g / m². 2 The following provisions are in place, which prevent gaseous components from dissolving into the polyisocyanate prepolymer and reduce the formation of air bubbles in the polyurethane resin when it is manufactured.

[0050] Furthermore, if the amount of water is high relative to the surface area of ​​the interface, water from the gaseous components in the voids can penetrate the polyisocyanate prepolymer (A) through the interface between the voids and the polyisocyanate prepolymer (A), resulting in the polyisocyanate prepolymer (A) becoming cloudy. In this case, the polyisocyanate prepolymer (A) may deteriorate in appearance inside the container, and depending on the degree of deterioration, it may be treated as a defective product. Therefore, it is preferable to prevent clouding as well. The water content is 1.05 g / m² relative to the interface area between the polyisocyanate prepolymer (A) and the voids. 2 The following steps can prevent clouding. Also, when the water content is 0.57 g / m with respect to the interfacial area between the polyisocyanate prepolymer (A) and the voids 2 or less, it is effective in that clouding can be prevented even when stored for a longer period.

[0051] Also, in the container, the water content may be 0 g / m with respect to the interfacial area between the polyisocyanate prepolymer (A) and the voids 2 This means that when gas analysis of the gas components in the container is performed, the water content is below the detection limit. Also, when the gas components in the container contain water, the water content may be 0.001 g / m or more with respect to the interfacial area between the polyisocyanate prepolymer (A) and the voids 2 or more.

[0052] Furthermore, in the container, it is preferable that the oxygen amount is 30.0 g / m or less with respect to the interfacial area between the polyisocyanate prepolymer (A) and the voids 2 When the oxygen amount with respect to the interfacial area is large in the container, the polyisocyanate prepolymer (A) may be oxidized and turn yellow during storage of the polyisocyanate prepolymer (A) in the container. From the viewpoint of preventing this yellowing, it is preferable that the oxygen amount is 30.0 g / m or less with respect to the interfacial area between the polyisocyanate prepolymer (A) and the voids 2 or less.

[0053] Also, in the container, the oxygen amount may be 0 g / m with respect to the interfacial area between the polyisocyanate prepolymer (A) and the voids 2 This means that when gas analysis of the gas components in the container is performed, the oxygen content is below the detection limit. Also, when the gas components in the container contain oxygen, the oxygen amount may be 0.0015 g / m or more with respect to the interfacial area between the polyisocyanate prepolymer (A) and the voids 2 or more.

[0054] ​In this specification, the amount of water contained in the gaseous components inside the container can be measured using a dew point meter, and the amount of oxygen can be measured using an oxygen concentration meter.

[0055] Within the container, the filling rate of the polyisocyanate prepolymer (A) relative to the container's internal volume is preferably 70% to 90% by volume, and more preferably 80% to 85% by volume. If the filling rate is low, the amount of gaseous components in the container increases, which increases the absolute amount of water and oxygen inside the container. In this case, there is a concern that the effect of setting the amount of water and oxygen relative to the interface area to below the specified value will be weakened.

[0056] There are no particular limitations on the method for producing the polyisocyanate prepolymer (A) contained in the container, but one method is to replace the gaseous components in the container with a dry gas when filling the container with the polyisocyanate prepolymer (A) synthesized by reacting diphenylmethane diisocyanates (a1) with an active hydrogen-containing compound (a2). By replacing with a dry gas, the amount of moisture contained in the gaseous components in the container is reduced, and the moisture content relative to the interface area between the polyisocyanate prepolymer (A) and the void is 1.05 g / m². 2 The following should be achieved. By thoroughly replacing the gaseous components inside the container with dry gas and then sealing the container, the polyisocyanate prepolymer can be produced.

[0057] As the drying gas, it is preferable to use a drying gas with a moisture content of 10.7 ppm or less. Furthermore, it is preferable to use a low-oxygen gas with an oxygen concentration of 50 ppm or less as the drying gas. By using a low-oxygen gas, the amount of oxygen relative to the interface area between the polyisocyanate prepolymer (A) and the void is 30.0 g / m². 2 The following is possible: As the low-oxygen gas, nitrogen gas, argon gas, etc., can be used. From these perspectives, it is more preferable to use a dry gas with a moisture content of 10.7 ppm or less and an oxygen concentration of 50 ppm or less, and most preferable to use nitrogen gas with a moisture content of 5.3 ppm or less and an oxygen concentration of 5 ppm or less.

[0058] Next, the preferred physical properties of the cured product obtained by reacting the curing agent composition (B) with the polyisocyanate prepolymer (A) contained in the container in the polyurethane resin forming kit of the present invention will be described.

[0059] It is preferable that the Shore D hardness of the cured product obtained by reacting the curing agent composition (B) with the polyisocyanate prepolymer (A) is 45 to 55. Shore D hardness can be measured at room temperature (23±2℃) in accordance with JIS K6253 for resin pieces of cured material obtained by curing a mixture of polyisocyanate prepolymer (A) and a curing agent composition (B).

[0060] It is preferable that the initial viscosity of the mixture obtained by mixing the curing agent composition (B) and the polyisocyanate prepolymer (A) is 900 mPa·s or less. It is also preferable that the initial viscosity of the mixture is 300 mPa·s or more. The initial viscosity of the mixture can be determined by mixing the polyisocyanate prepolymer (A) and the curing agent composition (B), stirring with a stirring blade at a rotational speed of 600 rpm, and measuring the viscosity of the mixture 1 minute after the start of stirring using a rotational viscometer (e.g., TVB-10M manufactured by Toki Sangyo Co., Ltd.) at a rotational speed of 60 rpm and 40°C.

[0061] Preferably, the gelation time of the mixture obtained by mixing the curing agent composition (B) and the polyisocyanate prepolymer (A) is 190 to 300 seconds. The gelation time is determined as the time required for the viscosity of the mixture to reach 10,000 mPa·s, following the measurement of the initial viscosity of the mixture as described above, while continuing stirring under the same temperature and shear conditions.

[0062] The number density of bubbles in the mixture obtained by mixing the curing agent composition (B) and the polyisocyanate prepolymer (A) is 20 bubbles / mm³. 2 The following is preferable: The number density of bubbles can be measured as follows. A cured product obtained by curing a mixture of polyisocyanate prepolymer (A) and a curing agent composition (B) is cut with a diamond cutter from the bottom side to obtain a roughly parallel surface, and an observation sample is prepared. If necessary, the cut surface is polished sequentially with waterproof abrasive paper (#800, #1500, #2000), and then polished with an alumina suspension to make the observation surface smooth or mirror-like. An optical microscope (total magnification 200x) is used to observe the surface, and an image is acquired for a field of view of 1.0 mm × 1.0 mm. The acquired images are imported into image analysis software, and the equivalent diameter of each bubble is calculated by converting the pixel size and scale bar. Bubbles with an equivalent diameter of 10 μm or more and less than 50 μm are extracted, and their number within the field of view is counted. Measurements were performed similarly on five different fields of view of the same sample, and the average value was used to determine the "number density of bubbles (bubbles / mm²) with a diameter of 10-50 μm." 2 )"

[0063] Next, the method for producing the polyurethane resin of the present invention will be described. The present invention provides a method for producing a polyurethane resin, which involves reacting a curing agent composition (B) of the present invention with a polyisocyanate prepolymer (A) contained in a container to obtain a polyurethane resin. The polyisocyanate prepolymer (A) contains a reaction product of diphenylmethane diisocyanate (a1-1) and / or a modified diphenylmethane diisocyanate (a1-2) and an active hydrogen-containing compound (a2), In the container, the water content is 1.05 g / m² relative to the interface area between the polyisocyanate prepolymer (A) and the void. 2 The following: This is a method for producing polyurethane resin, which involves mixing the curing agent composition (B) and the polyisocyanate prepolymer (A) at 25 to 45°C and reacting them.

[0064] The curing agent composition (B) used in the above polyurethane resin manufacturing method contains predetermined amounts of 2-octanol and sebacic acid. Furthermore, the polyisocyanate prepolymer (A) contained in the container has an interface area (0.25 m²) between the polyisocyanate prepolymer (A) and the voids. 2 The amount of water and oxygen in the ) is controlled within a predetermined range. A polyurethane resin can be obtained by mixing the curing agent composition (B) and the polyisocyanate prepolymer (A) as defined above at 25-45°C and allowing them to react. The polyurethane resin obtained in this manner has a low number density of air bubbles and a sufficiently high Shore D hardness. Furthermore, the initial viscosity of the mixture obtained by mixing the curing agent composition (B) with the polyisocyanate prepolymer (A) is appropriately low, and the gelation time can be adjusted to a range suitable for the process, resulting in excellent workability in the process of obtaining the polyurethane resin.

[0065] Next, the sealing material for the membrane module of the present invention will be described. The sealing material for the membrane module of the present invention is a polyurethane resin obtained by reacting the curing agent composition (B) and the polyisocyanate prepolymer (A) using the polyurethane resin forming kit of the present invention.

[0066] The polyurethane resin obtained by reacting a curing agent composition (B) with a polyisocyanate prepolymer (A) using the polyurethane resin forming kit of the present invention can be used as a polyurethane resin for sealing membrane modules. Specifically, it is particularly useful as a sealing material for artificial organs such as blood processors and water purifiers.

[0067] This specification discloses the following:

[0068] (1) The present disclosure is a curing agent composition (B) comprising a castor oil-based polyol, a hydroxyl group-containing amine compound, sebacic acid, and 2-octanol, wherein the sum of the concentrations of sebacic acid and 2-octanol based on the weight of the curing agent composition (B) is 170 to 230 ppm, and the ratio of the concentration of sebacic acid to the sum of the concentrations of 2-octanol and sebacic acid (sebacic acid / [2-octanol + sebacic acid]) is 0.83 to 0.91.

[0069] Disclosure (2) is the curing agent composition (B) according to Disclosure (1), wherein the concentration of sebacitic acid based on the weight of the curing agent composition (B) is 150 to 200 ppm.

[0070] Disclosure (3) is the curing agent composition (B) according to Disclosure (1) or (2), wherein the concentration of 2-octanol based on the weight of the curing agent composition (B) is 20 to 30 ppm.

[0071] Disclosure (4) relates to a polyurethane resin forming kit comprising a curing agent composition (B) described in any of Disclosures (1) to (3), and a polyisocyanate prepolymer (A) contained in a container, wherein the polyisocyanate prepolymer (A) contains a reaction product of diphenylmethane diisocyanate (a1-1) and / or a modified diphenylmethane diisocyanate (a1-2) and an active hydrogen-containing compound (a2), and the water content in the container is 1.05 g / m² relative to the interface area between the polyisocyanate prepolymer (A) and the voids. 2 The following is a polyurethane resin molding kit.

[0072] This disclosure (5) states that in the container, the amount of water relative to the interface area between the polyisocyanate prepolymer (A) and the void is 0.57 g / m². 2 The following is the polyurethane resin molding kit described in disclosure (4).

[0073] This disclosure (6) relates to the amount of oxygen in the container relative to the interface area between the polyisocyanate prepolymer (A) and the void, which is 30.0 g / m². 2 The following is a polyurethane resin molding kit as described in (4) or (5) of this disclosure.

[0074] Disclosure (7) is a polyurethane resin forming kit according to any one of Disclosures (4) to (6), wherein the cured product obtained by reacting the curing agent composition (B) with the polyisocyanate prepolymer (A) has a Shore D hardness of 45 to 55.

[0075] Disclosure (8) is a polyurethane resin forming kit according to any one of Disclosures (4) to (7), wherein the initial viscosity of the mixture obtained by mixing the curing agent composition (B) and the polyisocyanate prepolymer (A) is 900 mPa·s or less.

[0076] Disclosure (9) is a polyurethane resin forming kit according to any of Disclosures (4) to (8), wherein the gelation time of the mixture obtained by mixing the curing agent composition (B) and the polyisocyanate prepolymer (A) is 190 to 300 seconds.

[0077] This disclosure (10) provides a mixture obtained by mixing the curing agent composition (B) and the polyisocyanate prepolymer (A) having a bubble number density of 20 cells / mm³. 2 The following is a polyurethane resin molding kit as described in any of (4) to (9) of this disclosure.

[0078] The present disclosure (11) is a method for producing a polyurethane resin, comprising reacting a curing agent composition (B) described in any of the present disclosures (1) to (3) with a polyisocyanate prepolymer (A) contained in a container, wherein the polyisocyanate prepolymer (A) contains a reaction product of diphenylmethane diisocyanate (a1-1) and / or a modified diphenylmethane diisocyanate (a1-2) and an active hydrogen-containing compound (a2), and the water content in the container is 1.05 g / m² relative to the interface area between the polyisocyanate prepolymer (A) and the voids. 2 The following is a method for producing polyurethane resin, which involves mixing the curing agent composition (B) and the polyisocyanate prepolymer (A) at 25 to 45°C and allowing them to react.

[0079] The present disclosure (12) is a sealing material for a membrane module, which is a polyurethane resin obtained by reacting the curing agent composition (B) with the polyisocyanate prepolymer (A) using a polyurethane resin forming kit described in any of the present disclosures (4) to (10). [Examples]

[0080] The present invention will now be specifically described with reference to examples, but the present invention is not limited to these examples unless it deviates from the spirit of the invention.

[0081] [Polyisocyanate prepolymer (A)] (a-1) Diphenylmethane diisocyanate mixture A mixture of 2,4'-diphenylmethane diisocyanate and 4,4'-diphenylmethane diisocyanate (manufactured by BASF INOAC Polyurethane Co., Ltd., product name Lupranate® MI) (a-2) Polyether polyol Polypropylene glycol (manufactured by Sanyo Chemical Industries, Ltd., product name: Sannix® PP-1000)

[0082] [Hardening agent composition (B)] Castor oil-based polyols (b-1) Castor oil (manufactured by Toyokuni Oil Co., Ltd., ELA-DR) Polyol with castor oil triglyceride as the main component (b-2) Hydroxyl group-containing amine compounds Hydroxyl group-containing amine compound (manufactured by Sanyo Chemical Industries, Ltd., product name "Newpol NP-300"), a polyol formed by adding 4 moles of propylene oxide to ethylenediamine. (b-3) Polyether polyol Polyether polyol (PPG-1000, manufactured by Sanyo Chemical Industries, Ltd.) is a polypropylene glycol with a number average molecular weight of approximately 1000.

[0083] (Manufacturing Example 1) Manufacturing of Polyisocyanate Prepolymer (A-1) Diphenylmethane diisocyanate mixture (a-1) and polyether polyol (a-2) were weighed into a 2L stainless steel reaction vessel in amounts of 80% by weight for (a-1) and 20% by weight for (a-2) relative to the total weight of the raw materials for the polyisocyanate prepolymer (A), and charged under nitrogen purging. The reaction mixture was heated to 70°C under a nitrogen atmosphere and stirred at 70°C for 4 hours. After the reaction, the mixture was cooled to room temperature, and insoluble matter was removed by filtration to obtain polyisocyanate prepolymer (A). The NCO content of the obtained polyisocyanate prepolymer (A) was measured by titration and found to be 20% by weight. The viscosity at 25°C was approximately 1850 mPa·s. 200 kg of this polyisocyanate prepolymer (A) was filled into a steel drum, and the headspace was replaced with dry nitrogen gas with a moisture concentration of less than 10.7 ppm and an oxygen concentration of less than 50 ppm. The moisture and oxygen concentrations inside the container were measured using a dew point meter and an oxygen concentration meter, and the interfacial area between the polyisocyanate prepolymer (A) and the void (0.25 m²) was calculated from the void volume and liquid area. 2 The moisture content relative to ) is 0.52 g / m 2 The oxygen concentration is 14.80 g / m³. 2 That was the case. The polyisocyanate prepolymer (A) obtained in Production Example 1 was designated as polyisocyanate prepolymer (A-1).

[0084] (Comparative manufacturing example 1) Manufacturing of polyisocyanate prepolymer (A'-1) Similar to Production Example 1, the reaction mixture was reacted to obtain a polyisocyanate prepolymer (A) before filling it into steel drums. 200 kg of this polyisocyanate prepolymer (A) was filled into a steel drum, the headspace was replaced with dry nitrogen gas with a moisture concentration of less than 10.7 ppm and an oxygen concentration of less than 50 ppm, and the moisture and oxygen concentrations inside the container were measured using a dew point meter and an oxygen concentration meter. The moisture and oxygen levels in the void were adjusted to be higher than those in Production Example 1, and the lid was closed. Based on the void volume and liquid area, the interface area between the polyisocyanate prepolymer (A) and the void (0.25 m²) 2 The moisture content relative to ) is 1.30 g / m 2 The oxygen concentration is 18.00 g / m³. 2 That was the case. The polyisocyanate prepolymer (A) obtained in Comparative Production Example 1 was designated as polyisocyanate prepolymer (A'-1).

[0085] (Comparative manufacturing example 2) Manufacturing of polyisocyanate prepolymer (A'-2) Similar to Production Example 1, the reaction mixture was reacted to obtain a polyisocyanate prepolymer (A) before filling it into steel drums. 200 kg of this polyisocyanate prepolymer (A) was filled into a steel drum, the headspace was replaced with dry nitrogen gas with a moisture concentration of less than 10.7 ppm and an oxygen concentration of less than 50 ppm, and the moisture and oxygen concentrations inside the container were measured using a dew point meter and an oxygen concentration meter. The moisture and oxygen levels in the void were adjusted to be higher than those in Production Example 1, and the lid was closed. Based on the void volume and liquid area, the interface area between the polyisocyanate prepolymer (A) and the void (0.25 m²) 2 The moisture content relative to ) is 0.60 g / m 2 The oxygen concentration is 38.0 g / m³. 2 That was the case. The polyisocyanate prepolymer (A) obtained in comparative manufacturing example 2 was designated as polyisocyanate prepolymer (A'-2).

[0086] Table 1 summarizes the water content and oxygen content of the polyisocyanate prepolymer (A) obtained in Production Example 1, Comparative Production Example 1, and Comparative Production Example 2.

[0087] [Table 1]

[0088] (Manufacturing Example 2) Manufacturing of curing agent composition (B-1) 75.5 parts by weight of castor oil-based polyol (b-1) and 24.5 parts by weight of hydroxyl group-containing amine compound (b-2) were sequentially charged into a stainless steel stirring tank with an internal volume of 2 L. At room temperature (approximately 23°C), the mixture was stirred at 200 rpm for 30 minutes using an anchor-type impeller to obtain a homogeneous liquid mixture. If necessary, degassing was performed under reduced pressure of approximately 0.1 MPa for 5 minutes. The resulting mixture was designated as the curing agent composition (B-1). The viscosity, measured at 25°C at a rotational speed of 60 rpm using a rotational viscometer (TVB-10M, manufactured by Toki Sangyo Co., Ltd.), was 1340 mPa·s.

[0089] The concentrations of sebaciic acid and 2-octanol based on the weight of the curing agent composition (B-1) were measured by the following method. Specifically, the curing agent composition (B-1) was methyl esterified in methanol, and its concentration as dimethyl sebacate was determined by gas chromatography-mass spectrometry (GC-MS) to find the concentration of sebaic acid. For 2-octanol, 1-nonanol was added as an internal standard, and its concentration was similarly calculated from the peak area ratio by GC-MS. As a result, the concentration of sebacic acid based on the weight of the curing agent composition (B-1) was approximately 200 ppm, the concentration of 2-octanol was approximately 20 ppm, and the total concentration of 2-octanol and sebacic acid was approximately 220 ppm.

[0090] (Manufacturing Example 3) Manufacturing of curing agent composition (B-2) 71.5 parts by weight of castor oil-based polyol (b-1), 4.0 parts by weight of polyether polyol (b-3), and 24.5 parts by weight of hydroxyl group-containing amine compound (b-2) were sequentially charged into a stainless steel stirring tank with an internal volume of 2 L. At room temperature (approximately 23°C), the mixture was stirred at 200 rpm for 30 minutes using an anchor-type impeller to obtain a homogeneous liquid mixture. If necessary, degassing was performed under reduced pressure of approximately 0.1 MPa for 5 minutes. The resulting mixture was designated as the curing agent composition (B-2). Its viscosity at 25°C was 1231 mPa·s.

[0091] The concentrations of sebacic acid and 2-octanol were measured based on the weight of the curing agent composition (B-2) in the same manner as in Production Example 2. The concentration of sebacic acid was approximately 150 ppm, the concentration of 2-octanol was approximately 30 ppm, and the total concentration of 2-octanol and sebacic acid was approximately 180 ppm.

[0092] (Comparative manufacturing example 3) Manufacturing of curing agent composition (B'-1) As comparative manufacturing example 3, a curing agent composition (B'-1) substantially free of sebaic acid and 2-octanol was prepared. In comparative manufacturing example 3, castor oil-based polyol (b-1) and hydroxyl group-containing amine compound (b-2) were prepared as graded materials in which low molecular weight impurities were reduced by vacuum distillation and adsorbent treatment.

[0093] Next, 75.5 parts by weight of castor oil-based polyol (b'-1) and 24.5 parts by weight of hydroxyl group-containing amine compound (b'-2) were charged into a 2 L stirring tank, and the mixture was stirred at 200 rpm for 30 minutes at room temperature (approximately 23°C) using an anchor-type stirring blade to obtain a homogeneous liquid mixture. Degassing was performed under reduced pressure of approximately 0.1 MPa for 5 minutes as needed. The mixture obtained in this manner was designated as the curing agent composition (B'-1). Its viscosity at 25°C was 1340 mPa·s. The concentrations of sebaciic acid and 2-octanol were measured based on the weight of the curing agent composition (B'-1) in the same manner as in Production Example 2. Both the concentrations of sebaciic acid and 2-octanol were less than 10 ppm (below the detection limit).

[0094] Table 2 shows the raw materials and physical properties of the curing agent composition (B) produced in Production Examples 2 and 3 and Comparative Production Example 3.

[0095] [Table 2]

[0096] (Evaluation method) [Method for measuring initial viscosity and gelation time] A polyisocyanate prepolymer (A) and a curing agent composition (B) were blended in a weight ratio of 52 / 48 such that the equivalent ratio of NCO groups to hydroxyl groups (NCO / OH) was 1.0. At 25°C, stirring was initiated using a stirring blade in a mixing container separate from the disposable cup, and the mixture was continuously stirred for 1 minute from the start of stirring to obtain a homogeneous mixture. The viscosity of the mixture one minute after the start of stirring was measured at 40°C using a rotational viscometer (TVB-10M, manufactured by Toki Sangyo Co., Ltd.) at a rotational speed of 60 rpm, and this value was defined as the "initial viscosity of the mixture." The stirring was then continued under the same temperature and shear conditions, and the time required for the viscosity of the mixture to reach 10,000 mPa·s was measured and defined as the "gelation time."

[0097] [Method for measuring the number density of air bubbles] A mixture of polyisocyanate prepolymer (A) and curing agent composition (B) was carefully poured into a 150 mL disposable cup, taking care not to introduce air bubbles, and cured at 50°C for 3 days (72 hours). After curing, the cured resin was removed from the cup and cut with a diamond cutter from the bottom side to obtain a roughly parallel surface, thereby preparing a sample for observation. If necessary, the cut surfaces were polished sequentially with waterproof abrasive paper (#800, #1500, #2000), and then polished again with an alumina suspension to make the observation surface smooth or mirror-like. An optical microscope (total magnification 200x) was used to observe the surface, and images were acquired for a field of view of 1.0 mm × 1.0 mm. The acquired images were imported into image analysis software, and the equivalent diameter of each bubble was calculated by converting the pixel size and scale bar. Bubbles with an equivalent diameter of 10 μm or more and less than 50 μm were extracted, and their number within the field of view was counted. Measurements were performed similarly on five different fields of view of the same sample, and the average value was used to determine the "number density of bubbles (bubbles / mm²) with a diameter of 10-50 μm." 2 )”

[0098] [Curing conditions and method for measuring Shore D hardness] A mixture of polyisocyanate prepolymer (A) and curing agent composition (B) was gently poured into a 150 mL disposable cup and allowed to cure at 50°C for 3 days (72 hours). After curing, the cured resin was removed from the cup and cut with a diamond cutter to create resin pieces approximately 8 mm thick, ensuring that the thickness was nearly uniform. The obtained resin pieces were subjected to Shore D hardness testing at room temperature (23±2℃) in accordance with JIS K6253.

[0099] (Examples 1 and 2, Comparative Example 1, Examples 3 and 4) A polyisocyanate prepolymer (A) and a curing agent composition (B) were blended in a weight ratio of 52 / 48 such that the equivalent ratio of NCO groups to hydroxyl groups (NCO / OH) was 1.0. The mixture was then mixed and evaluated according to the [Method for measuring initial viscosity and gelation time]. Furthermore, the number density of bubbles and the Shore D hardness were measured using the obtained mixture according to the [Method for measuring bubble number density] and [Method for measuring curing conditions and Shore D hardness], respectively. The composition of the mixtures used and the evaluation results are summarized in Table 3.

[0100] [Table 3]

[0101] The curing agent compositions (B-1) and (B-2) produced in Production Examples 2 and 3 contain predetermined amounts of 2-octanol and sebacic acid. In contrast, the curing agent composition (B'-1) produced in Comparative Production Example 3 substantially does not contain 2-octanol or sebacic acid. The curing agent composition contains predetermined amounts of 2-octanol and sebacic acid, which moderately lowers the initial viscosity of the mixture when it is mixed with the polyisocyanate prepolymer (A), and also allows the gelation time to be adjusted to a range suitable for the process (around 200 seconds). Furthermore, the number density of microbubbles in the 10-50 μm range has been reduced.

[0102] Regarding the reduction of microbubbles, in the polyisocyanate prepolymer (A), the interface area between the polyisocyanate prepolymer (A) and the void (0.25 m²) 2 The control of the moisture and oxygen content within a predetermined range also contributes to this. By combining a polyisocyanate prepolymer (A-1) with controlled moisture and oxygen content with a curing agent composition (B-1) or (B-2) with controlled 2-octanol and sebacic acid content, it is possible to achieve both improved workability and a reduction in microbubbles. Furthermore, the Shore D hardness of the cured product obtained by hardening the mixture is sufficiently high.

[0103] In Examples 3 and 4, where polyisocyanate prepolymers (A'-1) or (A'-2) with moisture or oxygen content outside the controlled range were used, there was a slightly higher number of fine bubbles measuring 10-50 μm. In Examples 3 and 4, because curing agent composition (B-1) was used, the initial viscosity of the mixture when mixed with polyisocyanate prepolymer (A) was appropriately low, and the gelation time could be adjusted to a range suitable for the process (around 200 seconds).

Claims

1. Castor oil-based polyols, A hydroxyl group-containing amine compound, Sebacic acid and, A curing agent composition (B) comprising 2-octanol, The sum of the concentrations of sebaci acid and 2-octanol based on the weight of the curing agent composition (B) is 170 to 230 ppm. A curing agent composition (B) in which the ratio of the concentration of sebaciac acid to the total concentration of 2-octanol and sebaciac acid (sebaciac acid / [2-octanol + sebaciac acid]) is 0.83 to 0.

91.

2. The curing agent composition (B) according to claim 1, wherein the concentration of sebacitic acid based on the weight of the curing agent composition (B) is 150 to 200 ppm.

3. The curing agent composition (B) according to claim 1, wherein the concentration of 2-octanol based on the weight of the curing agent composition (B) is 20 to 30 ppm.

4. The curing agent composition (B) according to claim 1, A polyurethane resin forming kit comprising a polyisocyanate prepolymer (A) contained in a container, The polyisocyanate prepolymer (A) contains a reaction product of diphenylmethane diisocyanate (a1-1) and / or a modified diphenylmethane diisocyanate (a1-2) and an active hydrogen-containing compound (a2), In the container, the amount of water is 1.05 g / m² relative to the interface area between the polyisocyanate prepolymer (A) and the void. ２ The following is a polyurethane resin molding kit.

5. In the container, the amount of water is 0.57 g / m² relative to the interface area between the polyisocyanate prepolymer (A) and the voids. ２ The polyurethane resin forming kit according to claim 4 is as follows:

6. In the container, the amount of oxygen relative to the interface area between the polyisocyanate prepolymer (A) and the void is 30.0 g / m². ２ The polyurethane resin forming kit according to claim 4 is as follows:

7. The polyurethane resin forming kit according to claim 4, wherein the Shore D hardness of the cured product obtained by reacting the curing agent composition (B) with the polyisocyanate prepolymer (A) is 45 to 55.

8. The polyurethane resin forming kit according to claim 4, wherein the initial viscosity of the mixture obtained by mixing the curing agent composition (B) and the polyisocyanate prepolymer (A) is 900 mPa·s or less.

9. The polyurethane resin forming kit according to claim 4, wherein the gelation time of the mixture obtained by mixing the curing agent composition (B) and the polyisocyanate prepolymer (A) is 190 to 300 seconds.

10. The number density of bubbles in the mixture obtained by mixing the curing agent composition (B) and the polyisocyanate prepolymer (A) is 20 bubbles / mm². ２ The polyurethane resin forming kit according to claim 4 is as follows:

11. A method for producing a polyurethane resin, comprising reacting a curing agent composition (B) described in claim 1 with a polyisocyanate prepolymer (A) contained in a container to obtain a polyurethane resin, The polyisocyanate prepolymer (A) contains a reaction product of diphenylmethane diisocyanate (a1-1) and / or a modified diphenylmethane diisocyanate (a1-2) and an active hydrogen-containing compound (a2), In the container, the amount of water is 1.05 g / m² relative to the interface area between the polyisocyanate prepolymer (A) and the void. ２ The following: A method for producing polyurethane resin, comprising mixing the curing agent composition (B) and the polyisocyanate prepolymer (A) at 25 to 45°C and reacting them.

12. A sealing material for a membrane module, wherein the polyurethane resin is obtained by reacting the curing agent composition (B) with the polyisocyanate prepolymer (A) using the polyurethane resin forming kit described in claim 4.

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