Polyurethane resin-forming composition for membrane sealing material, and membrane sealing material and membrane module using the same

Abstract

Provided are: (1) a polyurethane resin-forming composition for a film sealing material having excellent moldability, which can suppress the dissolution of low-molecular-weight reactants and is conducive to forming a polyurethane resin with an excellent appearance; or (2) a polyurethane resin-forming composition for a film sealing material having low viscosity, excellent casting moldability, and is conducive to forming a polyurethane resin that can reduce the water dissolution of low-molecular-weight reactants and the solvent dissolution of a molded product. The polyurethane resin-forming composition for a film sealing material comprises: a polyisocyanate prepolymer (A) or an allophanate-group-containing polyisocyanate prepolymer (A') containing a reaction product of diphenylmethane diisocyanate (a1-1) and / or a modified form of diphenylmethane diisocyanate (a1-2) and an active hydrogen-containing compound (a2); and a castor oil polymerized polyol (b1) containing a castor oil polymer.

Description

Technical Field

[0001] The present disclosure relates to a polyurethane resin-forming composition for a membrane sealing material, and a membrane sealing material and a membrane module using the same. Background Art

[0002] Hollow fiber membranes used in hollow fiber membrane modules include glycerin-containing hollow fiber membranes that use a retaining agent (glycerin) to maintain membrane pores. However, it is known that when a polyurethane resin-forming composition containing diphenylmethane diisocyanate (hereinafter abbreviated as MDI) is used during casting of such glycerin-containing hollow fiber membranes, low-molecular-weight reaction products between MDI and glycerin are generated, and these reaction products are eluted into the liquid surrounding the hollow fiber membranes.

[0003] Therefore, Patent Document 1 discloses a polyurethane resin-forming composition for a membrane module sealant, comprising: a polyisocyanate component (main component) containing an isocyanate-terminated prepolymer obtained from a reaction product of MDI and castor oil; and a polyol component (curing agent). Patent Document 1 further discloses a method for reducing the amount of polyurethane resin eluted from the polyurethane resin-forming composition for a sealant.

[0004] Furthermore, in recent years, in order to improve the productivity of polyurethane resins for casting, there has been a strong demand for polyurethane resins having high mechanical strength.

[0005] Therefore, Patent Document 2 discloses a polyurethane resin-forming composition using carbodiimide-modified MDI as an isocyanate component and a castor oil polymer as a polyol component. Patent Document 2 further discloses that the polyurethane resin-forming composition has excellent mechanical properties.

[0006] In addition, allophanate group-containing polyisocyanate prepolymers derived from MDI and monohydric alcohols have low viscosity and little precipitation of MDI at low temperatures, making them easy to handle. Therefore, they are useful in the fields of adhesives and sealing materials and are widely used.

[0007] Patent Document 3 discloses that an allophanate group-containing polyisocyanate prepolymer derived from MDI and a polyether monool has a low viscosity and that an elastomer obtained from the prepolymer has excellent mechanical properties.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 6-25383

[0011] Patent Document 2: Japanese Patent Application Laid-Open No. 63-172781

[0012] Patent Document 3: Japanese Patent Application Laid-Open No. 2009-030059 Summary of the Invention

[0013] Problems to be solved by the invention

[0014] Therefore, the composition disclosed in Patent Document 1 has a high viscosity of the main component, and a lower viscosity is required. Therefore, the composition disclosed in Patent Document 1 has a problem of high initial viscosity after mixing the main component and the curing agent, which may cause filling defects during molding.

[0015] Furthermore, the composition disclosed in Patent Document 2 has poor compatibility during molding, and this may cause a problem in that the appearance of the molded product is poor.

[0016] Furthermore, the composition disclosed in Patent Document 3 has a problem in that a large amount of eluted matter is eluted from the polyurethane resin, and it is desired to reduce the amount of eluted matter.

[0017] Therefore, an object of one embodiment of the present disclosure is to provide a polyurethane resin-forming composition that has excellent moldability, can suppress the elution amount of low-molecular-weight reactants between diphenylmethane diisocyanate and glycerin, and is conducive to forming a polyurethane resin with excellent appearance, as well as a sealing material and a membrane assembly using the forming composition.

[0018] In addition, another embodiment of the present disclosure aims to provide a polyurethane resin forming composition that has low viscosity, excellent castability, and is advantageous for forming a polyurethane resin that can reduce the amount of water-soluble low-molecular-weight reactants of diphenylmethane diisocyanate and glycerin and the amount of solvent-soluble molded products, as well as a sealing material and a membrane assembly using the forming composition.

[0019] Solutions for solving problems

[0020] According to one embodiment of the present disclosure, there is provided a polyurethane resin-forming composition for a film sealing material, comprising a polyisocyanate prepolymer (A) and a curing agent (B).

[0021] The polyisocyanate prepolymer (A) comprises a reaction product of diphenylmethane diisocyanate (a1-1) and / or a modified diphenylmethane diisocyanate (a1-2) and an active hydrogen-containing compound (a2);

[0022] The curing agent (B) comprises castor oil polymer polyol (b1),

[0023] The castor oil polymer polyol (b1) comprises a castor oil polymer,

[0024] The content of the castor oil polymer is 1% by mass or more and 35% by mass or less relative to the total mass of the polyisocyanate prepolymer (A) and the curing agent (B).

[0025] According to another embodiment of the present disclosure, there is provided a polyurethane resin-forming composition for a film sealing material, comprising an allophanate group-containing polyisocyanate prepolymer (A') and a curing agent (B).

[0026] The allophanate group-containing polyisocyanate prepolymer (A') comprises a reaction product of diphenylmethane diisocyanate (a1-1) and an active hydrogen-containing compound (a2).

[0027] The curing agent (B) comprises castor oil polymer polyol (b1),

[0028] The castor oil polymer polyol (b1) comprises a castor oil polymer,

[0029] The crosslinking group density of the polyurethane resin-forming composition for a film sealing material is 0.65 mmol / g or more relative to the total mass of the allophanate group-containing polyisocyanate prepolymer (A′) and the curing agent (B).

[0030] According to another embodiment of the present disclosure, there is provided a polyurethane resin-forming composition for a film sealing material, comprising an allophanate group-containing polyisocyanate prepolymer (A') and a curing agent (B).

[0031] The allophanate group-containing polyisocyanate prepolymer (A') comprises a reaction product of diphenylmethane diisocyanate (a1-1) and an active hydrogen-containing compound (a2).

[0032] The curing agent (B) comprises castor oil polymer polyol (b1),

[0033] The castor oil polymer polyol (b1) comprises a castor oil polymer,

[0034] The content of the castor oil polymer is 1% by mass or more and 35% by mass or less relative to the total mass of the allophanate group-containing polyisocyanate prepolymer (A′) and the curing agent (B).

[0035] According to another aspect of the present disclosure, there is provided a film sealing material including a cured product of the polyurethane resin-forming composition for a film sealing material.

[0036] According to another embodiment of the present disclosure, there is provided a membrane module comprising:

[0037] Main body;

[0038] membrane; and,

[0039] a membrane sealing material for sealing the gap between the main body and the membrane;

[0040] The aforementioned film sealing material is the above-mentioned film sealing material.

[0041] Effects of the Invention

[0042] According to one embodiment of the present disclosure, there can be provided a polyurethane resin-forming composition having excellent moldability, suppressing the elution amount of low-molecular-weight reactants of diphenylmethane diisocyanate and glycerin, and facilitating the formation of a polyurethane resin having an excellent appearance, as well as a sealing material and a membrane module using the forming composition.

[0043] In addition, according to another embodiment of the present disclosure, there can be provided: a polyurethane resin forming composition that has low viscosity, excellent castability, and is conducive to forming a polyurethane resin that can reduce the water dissolution amount of low molecular weight reaction products of MDI and glycerin and the solvent dissolution amount of the molded product; as well as a sealing material and a membrane assembly using the forming composition. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a conceptual diagram illustrating an example of the configuration of a membrane module according to one embodiment of the present disclosure. DETAILED DESCRIPTION

[0045] Hereinafter, exemplary embodiments of the present disclosure will be described in detail.

[0046] [First embodiment (polyurethane resin-forming composition for film sealing material)]

[0047] The polyurethane resin-forming composition for film sealing materials according to the first aspect of the present disclosure comprises a polyisocyanate prepolymer (A) and a curing agent (B).

[0048] The polyisocyanate prepolymer (A) comprises a reaction product of diphenylmethane diisocyanate (a1-1) and / or a modified diphenylmethane diisocyanate (a1-2) and an active hydrogen-containing compound (a2);

[0049] The curing agent (B) comprises castor oil polymer polyol (b1),

[0050] The castor oil polymer polyol (b1) comprises a castor oil polymer,

[0051] The content of the castor oil polymer is 1% by mass or more and 35% by mass or less relative to the total mass of the polyisocyanate prepolymer (A) and the curing agent (B).

[0052] <Polyisocyanate prepolymer (A)>

[0053] 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).

[0054] <<Diphenylmethane diisocyanate (a1-1), modified form thereof (a1-2)>>

[0055] As diphenylmethane diisocyanate (a1-1), any commonly available diphenylmethane diisocyanate (hereinafter also referred to as MDI) monomer may be used. Regarding the isomers of the MDI monomer, the content is generally 0% to 5% by mass of 2,2'-MDI, 0% to 95% by mass of 2,4'-MDI, and 5% to 100% by mass of 4,4'-MDI.

[0056] The modified form (a1-2) of the aforementioned MDI is not particularly limited, and examples thereof include carbamate modified forms, carbodiimide modified forms, polymers, urea modified forms, allophanate modified forms, biuret modified forms, uretonimine modified forms, uretdione modified forms, and the like. One type may be used alone or two or more types may be mixed.

[0057] <<Active hydrogen-containing compound (a2)>>

[0058] The active hydrogen-containing compound (a2) is not particularly limited as long as it is a compound containing active hydrogen. Examples of the active hydrogen-containing compound (a2) include polyols such as castor oil, castor oil-modified polyols, low-molecular-weight polyols, polyether polyols, polyester polyols, polylactone polyols, and polyolefin polyols.

[0059] Examples of castor oil-modified polyols include linear or branched castor oil-modified polyols obtained by reacting castor oil or castor oil fatty acids with at least one polyol selected from the group consisting of low-molecular-weight polyols and polyether polyols. Specific examples include diglycerides and monoglycerides of castor oil fatty acids; monoesters, diesters, and triesters of castor oil fatty acids with trimethylolalkanes; and monoesters, diesters, and triesters of castor oil fatty acids with polypropylene glycol.

[0060] It should be noted that the main component of castor oil is triglyceride of ricinoleic acid, and castor oil includes hydrogenated castor oil. In addition, the main component of castor oil fatty acid is ricinoleic acid, and castor oil fatty acid includes hydrogenated castor oil fatty acid.

[0061] Examples of the trimethylolalkanes include trimethylolmethane, trimethylolethane, trimethylolpropane, trimethylolbutane, trimethylolpentane, trimethylolhexane, trimethylolheptane, trimethyloloctane, trimethylolnonane, and trimethyloldecane.

[0062] The number average molecular weight of the castor oil-modified polyol is preferably 400 to 3000, more preferably 500 to 2500. By using a castor oil-modified polyol having a number average molecular weight of 400 to 3000, a cured resin having further excellent physical properties, particularly mechanical properties, required for a film sealing material can be formed.

[0063] The average hydroxyl value of castor oil and castor oil-modified polyols is preferably 20 mgKOH / g to 300 mgKOH / g, and more preferably 40 mgKOH / g to 250 mgKOH / g. Using castor oil-modified polyols with an average hydroxyl value of 20 mgKOH / g to 300 mgKOH / g allows for the formation of a cured resin with even better physical properties, particularly mechanical properties, required for membrane sealing materials. Furthermore, this can improve the productivity of membrane sealing materials and, by extension, the productivity of hollow fiber membrane modules.

[0064] 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; and trivalent to octavalent polyols such as glycerol, trimethylolpropane, hexanetriol, pentaerythritol, sorbitol, and sucrose. The number average molecular weight of the low-molecular-weight polyol is preferably 50 or more and 200 or less.

[0065] Examples of polyether polyols include alkylene oxide (alkylene oxides having 2 to 8 carbon atoms, such as ethylene oxide, propylene oxide, and butylene oxide) adducts of the above-mentioned low molecular weight polyols and ring-opening polymers of alkylene oxides. Specific examples include polypropylene glycol, polyethylene glycol, polytetramethylene ether glycol, and copolymers of ethylene oxide and propylene oxide. From the perspective of excellent moldability when manufacturing film sealing materials, the number average molecular weight of the polyether polyol is preferably 200 to 7000, more preferably 500 to 5000.

[0066] Examples of the polyester polyol include polyester polyols obtained by polycondensation of polycarboxylic acids and polyols.

[0067] Examples of the polycarboxylic acid used in the polyester polyol include aliphatic saturated and unsaturated polycarboxylic acids such as adipic acid, azelaic acid, dodecanedioic acid, maleic acid, fumaric acid, itaconic acid, dimerized linoleic acid, phthalic acid, isophthalic acid, and terephthalic acid, and aromatic polycarboxylic acids.

[0068] Examples of the polyol used for the polyester polyol include the above-mentioned low-molecular-weight polyols and polyether polyols.

[0069] The number average molecular weight of the polyester polyol is preferably 200 to 5000, more preferably 500 to 3000. The use of a polyester polyol having a number average molecular weight of 200 to 5000 provides particularly excellent molding processability when forming a film sealing material.

[0070] Examples of polylactone polyols include polyols obtained by addition polymerization of a diol or triol polymerization initiator with ε-caprolactone, α-methyl-ε-caprolactone, ε-methyl-ε-caprolactone, β-methyl-δ-valerolactone, or the like in the presence of a catalyst such as an organometallic compound, a metal chelate compound, or a fatty acid metal acyl compound. The number average molecular weight of the polylactone polyol is preferably 200 to 5000, more preferably 500 to 3000. Using a polylactone polyol with a number average molecular weight of 200 to 5000 results in particularly excellent moldability when forming a film sealing material.

[0071] Examples of polyolefin polyols include polybutadiene polyols obtained by introducing hydroxyl groups into the terminals of polybutadiene or copolymers of butadiene and styrene or acrylonitrile. Furthermore, examples include polyetherester polyols obtained by addition reaction of polyesters having carboxyl and hydroxyl groups at the terminals with alkylene oxides such as ethylene oxide and propylene oxide.

[0072] Among them, the active hydrogen-containing compound (a2) is preferably castor oil or a castor oil-modified polyol in consideration of compatibility with the curing agent (curing agent (B)).

[0073] <<Preparation method of polyisocyanate prepolymer (A)>>

[0074] The polyisocyanate prepolymer (A) comprises a reaction product of diphenylmethane diisocyanate (a1-1) and / or a modified diphenylmethane diisocyanate (a1-2) and an active hydrogen-containing compound (a2). This reaction product can be obtained by a conventional urethanization reaction.

[0075] <<Isocyanate group content>>

[0076] The isocyanate group content of the polyisocyanate prepolymer (A) is preferably 13.0% by mass or more and 21.0% by mass or less, more preferably 13.5% by mass or more and 20.5% by mass or less, and particularly preferably 14.0% by mass or more and 20.0% by mass or less. Within these ranges, the molding processability and adhesive strength of the polyurethane resin are further improved.

[0077] <<MDI monomer content>>

[0078] In order to further reduce the low-molecular-weight reaction products of MDI and glycerin, the content of the MDI monomer is preferably 25% by mass or less based on the total amount of the polyurethane resin-forming composition for a film sealing material.

[0079] <<Reaction temperature>>

[0080] The urethanization reaction is preferably carried out within a temperature range of 40°C to 80°C until the target NCO content is achieved. A temperature of 40°C or higher can better suppress the crystallization of monomeric MDI, while a temperature of 80°C or lower can further suppress the formation of side reactions.

[0081] Curing agent (B)

[0082] The curing agent (B) contains castor oil polymerized polyol (b1).

[0083] In addition, it is preferred that the curing agent (B) contains:

[0084] Castor oil polymerized polyol (b1), and

[0085] At least one (b2) selected from the group consisting of castor oil and castor oil-modified polyols.

[0086] Furthermore, in this embodiment, it is more preferable that the curing agent (B) contains:

[0087] Castor oil polymer polyol (b1),

[0088] At least one selected from the group consisting of castor oil and castor oil-modified polyols (b2), and a hydroxyl group-containing amine compound (b3);

[0089] The content of the hydroxyl group-containing amine compound (b3) in the curing agent (B) is 30% by mass or less.

[0090] <<Castor oil polymerized polyol (b1)>>

[0091] The castor oil polymerized polyol (b1) contains a castor oil polymer. By including the castor oil polymerized polyol (b1), more excellent effects such as improved processability during molding and suppression of eluted matter are exhibited.

[0092] The content of the castor oil polymer is preferably from 1.0% to 35.0% by mass, more preferably from 2.0% to 34.0% by mass, and particularly preferably from 3.0% to 33.0% by mass, relative to the total mass of the polyisocyanate prepolymer (A) and the curing agent (B). Within these ranges, the moldability and reduction of the elution amount of the polyurethane resin are further improved.

[0093] It should be noted that castor oil polymerized polyol (b1) may contain castor oil polymer and castor oil (non-polymerized). In this case, the content of castor oil polymer in castor oil polymerized polyol (b1) can be calculated, for example, by measuring using GPC (Gel Permeation Chromatography), with those with a molecular weight of 1500 or greater being considered castor oil polymer. However, the method for calculating the content of castor oil polymer is not limited to this method, and any method may be used as long as it can accurately distinguish between castor oil polymer and castor oil (non-polymerized).

[0094] <<At least one polyol (b2) selected from the group consisting of castor oil and castor oil-modified polyols>>

[0095] There are no particular restrictions on castor oil and castor oil-modified polyols.

[0096] Castor oil is castor oil itself.

[0097] Examples of the castor oil-modified polyol include the same castor oil-modified polyols as those exemplified for the active hydrogen-containing compound (a2).

[0098] <<Hydroxy-containing amine compound (b3)>>

[0099] The hydroxyl-containing amine compound (b3) is a hydroxyl-containing amine compound other than castor oil polymerized polyol (b1) and at least one polyol (b2) selected from the group consisting of castor oil and castor oil-based modified polyols. In other words, the hydroxyl-containing amine compound (b3) is a hydroxyl-containing amine compound that does not belong to castor oil polymerized polyol (b1) or polyol (b2).

[0100] Examples of the hydroxyl-containing amine compound (b3) include amine compounds such as alkyldiethanolamines (for example, linear or branched butyldiethanolamine, hexyldiethanolamine, octyldiethanolamine, lauryldiethanolamine, myristyldiethanolamine, hexadecyldiethanolamine, and stearyldiethanolamine), low-molecular-weight polyamines, low-molecular-weight amino alcohols, and the like (for example, propylene oxide or ethylene oxide adducts of ethylenediamine, i.e., oxyalkylated derivatives of amino compounds such as N,N,N',N'-tetrakis[2-hydroxypropyl]ethylenediamine and N,N,N',N'-tetrakis[2-hydroxyethyl]ethylenediamine; monoethanolamine, diethanolamine, triethanolamine; N-methyl-N,N'-diethanolamine, and the like), and amino alcohol derivatives.

[0101] Among these, propylene oxide or ethylene oxide adducts of amino compounds such as ethylenediamine are preferred, with N,N,N',N'-tetrakis[2-hydroxypropyl]ethylenediamine being most preferred. The use of N,N,N',N'-tetrakis[2-hydroxypropyl]ethylenediamine further improves processability during molding and reduces extractables.

[0102] In addition, in this embodiment, the content of the hydroxyl-containing amine compound (b3) in the curing agent (B) is preferably 30% by mass or less, more preferably 5% by mass or more and 30% by mass or less, and particularly preferably 10% by mass or more and 25% by mass or less. If the content of the hydroxyl-containing amine compound (b3) in the curing agent (B) is 5% by mass or more, the hydroxyl-containing amine compound (b3) can better play the role of curing promotion and exert a further effect. If the ratio of the hydroxyl-containing amine compound (b3) in the curing agent (B) is 30% by mass or less, the reactivity can be further suppressed from becoming excessively high, the workability can be further improved, the filling property can be ensured, and the hardness of the obtained film sealing material can be further suppressed from becoming excessively high.

[0103] <<Active hydrogen-containing compound (b4)>>

[0104] The curing agent (B) may contain an active hydrogen-containing compound (hereinafter referred to as "active hydrogen-containing compound (b4)") other than the castor oil polymerized polyol (b1), the polyol (b2), and the hydroxyl-containing amine compound (b3). As the active hydrogen-containing compound (b4), the various polyols listed above for the active hydrogen-containing compound (a2) can be used.

[0105] In the curing agent (B), the mass ratio (Mb2) / (Mb4) of the content Mb2 of at least one polyol (b2) selected from the group consisting of castor oil and castor oil-modified polyols to the content Mb4 of the active hydrogen-containing compound (b4) is preferably 50 / 50 or more and 100 / 0 or less, and particularly preferably 100 / 0. Specifically, the curing agent (B) is particularly preferably composed solely of the castor oil-polymerized polyol (b1) and the polyol (b2), or solely of the castor oil-polymerized polyol (b1), the polyol (b2), and the hydroxyl-containing amine compound (b3).

[0106] In addition, when the content of the castor oil polymerized polyol (b1) is set to Mb1 and the content of the hydroxyl-containing amine compound (b3) is set to Mb3, taking into account the hydroxyl-containing amine compound (b3), the mass ratio (Mb3) / {(Mb1)+(Mb2)} is preferably greater than 5 / 95 and less than 30 / 70, and from the viewpoint of curing properties and filling properties, it is further preferably greater than 10 / 90 and less than 25 / 75.

[0107] The hydroxyl value of the curing agent (B) is preferably 50 mgKOH / g to 1000 mgKOH / g, and more preferably 75 mgKOH / g to 750 mgKOH / g from the perspective of easy handling of the curing agent (B). From the perspective of excellent moldability and adhesive strength of the polyurethane resin, the hydroxyl value of the curing agent (B) is most preferably 100 mgKOH / g to 500 mgKOH / g.

[0108] The viscosity of the curing agent (B) at 25°C is preferably from 100 mPa·s to 6000 mPa·s, and more preferably from 150 mPa·s to 4000 mPa·s from the viewpoint of easy handling of the curing agent (B). From the viewpoint of excellent molding processability of the polyurethane resin, the viscosity of the curing agent (B) at 25°C is most preferably from 200 mPa·s to 2000 mPa·s.

[0109] Viscosity

[0110] For the polyurethane resin-forming composition for film sealing materials, when the viscosity 60 seconds after the start of mixing of the polyisocyanate prepolymer (A) and the curing agent (B) is defined as the mixed viscosity, it is preferably 400 mPa·s or more and 2100 mPa·s or less, and more preferably 500 mPa·s or more and 1800 mPa·s or less.

[0111] According to the first aspect of the present disclosure, there can be provided a polyurethane resin-forming composition that has excellent moldability, can suppress the elution amount of low-molecular-weight reaction products of MDI and glycerin, and is advantageous for forming a polyurethane resin having an excellent appearance, as well as a sealing material and a film module using the forming composition.

[0112] [Second and third aspects (polyurethane resin-forming composition for film sealing material)]

[0113] The polyurethane resin-forming composition for film sealing materials according to the second aspect of the present disclosure comprises an allophanate group-containing polyisocyanate prepolymer (A′) and a curing agent (B).

[0114] The allophanate group-containing polyisocyanate prepolymer (A') comprises a reaction product of diphenylmethane diisocyanate (a1-1) and an active hydrogen-containing compound (a2).

[0115] The curing agent (B) comprises castor oil polymer polyol (b1),

[0116] The castor oil polymer polyol (b1) comprises a castor oil polymer,

[0117] The crosslinking group density is 0.65 mmol / g or more relative to the total mass of the polyisocyanate prepolymer (A') and the curing agent (B).

[0118] The polyurethane resin-forming composition for film sealing materials according to the third aspect of the present disclosure comprises an allophanate group-containing polyisocyanate prepolymer (A′) and a curing agent (B).

[0119] The polyisocyanate prepolymer (A') contains a reaction product of diphenylmethane diisocyanate (a1-1) and an active hydrogen-containing compound (a2).

[0120] The curing agent (B) comprises castor oil polymer polyol (b1),

[0121] The castor oil polymer polyol (b1) comprises a castor oil polymer,

[0122] The content of the castor oil polymer is 1% by mass or more and 35% by mass or less relative to the total mass of the polyisocyanate prepolymer (A') and the curing agent (B).

[0123] Hereinafter, the polyurethane resin-forming compositions for film sealing materials according to the second and third aspects will be described, but descriptions overlapping with those of the polyurethane resin-forming composition for film sealing materials according to the first aspect will be omitted.

[0124] It should be noted that in the description of the polyurethane resin-forming composition for film sealing materials involved in the above-mentioned first embodiment, excluding the positions that are restrictively recorded as "in this embodiment" (i.e., in the first embodiment), any description can be applied to the polyurethane resin-forming composition for film sealing materials involved in the second and third embodiments.

[0125] <Allophanate group-containing polyisocyanate prepolymer (A')>

[0126] The allophanate group-containing polyisocyanate prepolymer (A') contains a reaction product of diphenylmethane diisocyanate (a1-1) and an active hydrogen-containing compound (a2).

[0127] MDI (a-1) can be exemplified by the same examples as those described in the first embodiment, and therefore, a description thereof will be omitted. However, if a certain degree of viscosity increase of the allophanate-containing polyisocyanate prepolymer (A') is permitted, polymethylene polyphenylene polyisocyanate (polymeric MDI) can also be used as MDI (a1-1). In this case, the content of the polymethylene polyphenylene polyisocyanate in the isocyanate component used is preferably 0% by mass or more and 50% by mass or less. If it is 50% by mass or less, the viscosity is sufficiently low, and the formation of insoluble matter can also be further suppressed.

[0128] Examples of the active hydrogen-containing compound (a2) include the same compounds as those in the first embodiment, and include monohydric alcohols, such as aliphatic monohydric alcohols, aromatic monohydric alcohols, alicyclic monohydric alcohols, aromatic aliphatic monohydric alcohols, and polyoxypropylene glycol monoalkyl ethers.

[0129] Examples of the aliphatic monohydric alcohol include methanol, ethanol, 1-propanol and 2-propanol, 1-butanol and 2-butanol, 1-pentanol, 1-hexanol, 2-methyl-1-pentanol, 4-methyl-2-pentanol, 2-ethyl-1-butanol, 1-heptanol, 1-octanol, 2-octanol, 2-ethylhexanol, 3,5-dimethyl-1-hexanol, 2,2,4-trimethyl-1-pentanol, 1-nonanol, 2,6-dimethyl-4-heptanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-heptadecanol, 1-octadecanol, 1-nonadecanol, 1-eicosanol, 1-hexacosanol, 1-heptacosacanol, 1-oleyl alcohol, and 2-octyldodecanol, and mixtures thereof.

[0130] The number average molecular weight of the aliphatic monohydric alcohol is preferably 32 or more and 1500 or less, more preferably 100 or more and 1000 or less. When the molecular weight is within this range, the moldability and adhesive strength of the polyurethane resin are further improved.

[0131] Examples of the aromatic monohydric alcohol include phenol and cresol.

[0132] Examples of the alicyclic monohydric alcohol include cyclohexanol and methylcyclohexanol.

[0133] Examples of the aromatic aliphatic monohydric alcohol include benzyl alcohol and the like.

[0134] Examples of the polyoxypropylene glycol monoalkyl ether include reaction products of the aforementioned aliphatic monohydric alcohols and polyoxypropylene glycol, including polyoxypropylene methyl ether, polyoxypropylene ethyl ether, polyoxypropylene butyl ether, polyoxypropylene-2-ethylhexyl ether, polyoxypropylene oleyl ether, polyoxypropylene-2-octyldodecyl ether, and mixtures thereof.

[0135] The number average molecular weight of the polyoxypropylene glycol monoalkyl ether is preferably 90 to 1500. In order to achieve better molding processability and adhesive strength of the polyurethane resin, the number average molecular weight is more preferably 150 to 1000.

[0136] Among them, the active hydrogen-containing compound (a2) is preferably an aliphatic alcohol having 10 or more carbon atoms, castor oil, or a castor oil-modified polyol, in consideration of compatibility with the curing agent (B).

[0137] <<Method for producing allophanate group-containing polyisocyanate prepolymer (A')>>

[0138] The allophanate group-containing polyisocyanate prepolymer (A') is preferably obtained, for example, by subjecting diphenylmethane diisocyanate (a1-1) and an active hydrogen-containing compound (a2) to a urethanization reaction, then adding a predetermined amount of a catalyst (a3) ​​to allophanation, and terminating the reaction with a catalyst poison (a4).

[0139] <<Catalyst (a3)>>

[0140] Examples of the catalyst (a3) ​​include zinc acetylacetonate; metal carboxylates of zinc, lead, tin, copper, cobalt, etc., with carboxylic acids, and mixtures thereof; tertiary amines, tertiary amino alcohols, quaternary ammonium salts, and mixtures thereof; and the like.

[0141] The amount of catalyst (a3) ​​added is preferably in the range of 1 ppm to 500 ppm, more preferably in the range of 5 ppm to 300 ppm, relative to the total mass of diphenylmethane diisocyanate (a1-1) and the active hydrogen-containing compound (a2). A concentration of 1 ppm or more promotes a more rapid reaction, while a concentration of 500 ppm or less is preferred because coloration of the prepolymer is further effectively suppressed.

[0142] <<Active methylene compounds>>

[0143] In the allophanation reaction using tertiary amines or quaternary ammonium salts in the present disclosure, when the reaction is rapid and difficult to control, it is effective to add at least one selected from the group consisting of carboxamides, sulfonamides, and active methylene compounds represented by formula (1).

[0144]

[0145] Where,

[0146] R 1 is any one selected from the group consisting of a hydrogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an arylalkyl group, and an aryl group,

[0147] R 2 and R 3 Each is independently any one selected from the group consisting of a hydroxyl group, an alkyl group, an alkenyl group, a cycloalkyl group, an arylalkyl group, an aryl group, an oxyalkyl group, an oxyalkenyl group, an oxycycloalkyl group, an oxyarylalkyl group, and an oxyaryl group.

[0148] Examples of the carboxamide include formamide, acetamide, propionamide, butyramide, isobutyramide, hexylamide, octylamide, 2-ethylhexylamide, oleamide, stearylamide, benzamide, 2-phenylacetamide, 4-methylbenzamide, 2-aminobenzamide, 3-aminobenzamide, 4-aminobenzamide, and mixtures thereof.

[0149] Examples of the sulfonamide include methylsulfonamide, butylsulfonamide, tert-butylsulfonamide, phenylsulfonamide, benzylsulfonamide, o-toluoylsulfonamide, p-toluoylsulfonamide, 3-aminophenylsulfonamide, 4-aminophenylsulfonamide, and mixtures thereof.

[0150] Specific examples of the active methylene compound represented by formula (1) include acetylacetone, 3-methyl-2,4-pentanedione, 3-ethyl-2,4-pentanedione, 3,5-heptanedione, 3,5-heptanedione, 6-methyl-2,4-heptanedione, methyl acetoacetate, ethyl acetoacetate, methyl 3-oxopentanoate, malonic acid, dimethyl malonate, and diethyl malonate. The active methylene compound may be a mixture of two or more of these.

[0151] Furthermore, it is preferred that at least one selected from the group consisting of the carboxamide, sulfonamide, and active methylene compound represented by the formula (1) is added from immediately before the addition of the catalyst until 30 minutes after the addition of the catalyst.

[0152] The higher the temperature for allophanation, the higher the rate of allophanate group formation, which tends to lower the viscosity. However, this also increases the likelihood of side reactions such as uretdione formation and carbodiimidization. Furthermore, in reactions at low temperatures, the amount of isocyanurate group formation increases, leading to higher viscosity. Therefore, the reaction temperature is preferably between 20°C and 200°C. To suppress the rate of isocyanurate group formation to 20 mol% or less and achieve even lower viscosity, the reaction temperature is preferably between 60°C and 160°C.

[0153] <<Catalyst poison (a4)>>

[0154] The catalyst poison (a4) is preferably an acidic substance. Examples of the catalyst poison (a4) include anhydrous hydrogen chloride, sulfuric acid, phosphoric acid, monoalkyl sulfates, alkylsulfonic acids, alkylbenzenesulfonic acids, monoalkyl or dialkyl phosphates, benzoyl chloride, and Lewis acids. The amount of the catalyst poison (a4) added is preferably an equivalent amount or more relative to the number of moles of the catalyst (a3), and more preferably an amount of 1.0 times the molar equivalent and 1.5 times the molar equivalent of the catalyst (a3).

[0155] <<Reaction temperature>>

[0156] The urethanization reaction is preferably carried out within a temperature range of 40°C to 80°C until the target NCO content is achieved. A temperature of 40°C or higher can better suppress the crystallization of monomeric MDI, while a temperature of 80°C or lower can further suppress the formation of side reactions.

[0157] The allophanation reaction is preferably carried out within a temperature range of 90° C. to 130° C. until the target NCO content is reached. At 90° C. or higher, the reaction proceeds more rapidly, while at 130° C. or lower, the formation of side reaction products can be further suppressed.

[0158] Curing agent (B)

[0159] The curing agent (B) contains castor oil polymerized polyol (b1).

[0160] In addition, it is preferred that the curing agent (B) contains:

[0161] Castor oil polymerized polyol (b1), and

[0162] At least one polyol (b2) selected from the group consisting of castor oil and castor oil-modified polyols.

[0163] Furthermore, in this embodiment, it is more preferable that the curing agent (B) contains:

[0164] Castor oil polymer polyol (b1),

[0165] At least one polyol (b2) selected from the group consisting of castor oil and castor oil-modified polyols, and

[0166] a hydroxyl-containing amine compound (b3) other than the aforementioned castor oil polymerized polyol (b1) and the aforementioned polyol (b2);

[0167] The content of the hydroxyl group-containing amine compound (b3) in the curing agent (B) is 35% by mass or less.

[0168] In this embodiment, the content of the castor oil polymer is preferably 1.0% by mass to 35.0% by mass, more preferably 2.0% by mass to 25.0% by mass, and particularly preferably 3.0% by mass to 15.0% by mass, relative to the total mass of the polyisocyanate prepolymer (A) and the curing agent (B). Within these ranges, the moldability and reduction of the elution amount of the polyurethane resin are further improved.

[0169] In addition, in this embodiment, when containing a hydroxyl-containing amine compound (b3), the content of the hydroxyl-containing amine compound (b3) in the curing agent (B) is preferably 35% by mass or less, more preferably 5% by mass or more and 34% by mass or less, and particularly preferably 10% by mass or more and 33% by mass or less. If the content of the hydroxyl-containing amine compound (b3) in the curing agent (B) is 5% by mass or more, the hydroxyl-containing amine compound (b3) can better play the role of curing promotion and exert a further effect. If the ratio of the hydroxyl-containing amine compound (b3) in the curing agent (B) is 35% by mass or less, the reactivity is further suppressed from becoming excessively high, the workability is further improved, the filling property is ensured, and the hardness of the obtained film sealing material is further suppressed from becoming excessively high.

[0170] Furthermore, in the present embodiment, when the active hydrogen-containing compound (b4) is contained, the mass ratio (Mb3) / {(Mb1)+(Mb2)} is preferably 5 / 95 or more and 35 / 65 or less, and is more preferably 10 / 90 or more and 33 / 67 or less from the viewpoint of curability and filling properties.

[0171] Cross-linking group density

[0172] To reduce the amount of elution into the solvent, the crosslinking group density of the polyurethane resin-forming composition for film sealing materials is preferably 0.65 mmol / g or greater, more preferably 0.70 mmol / g or greater, and particularly preferably 0.75 mmol / g or greater and 1.20 or less, relative to the total mass of the polyisocyanate prepolymer (A') and the curing agent (B). A crosslinking group density of 1.20 or less improves molding processability.

[0173] The cross-linking group density refers to the total content density of the groups capable of forming cross-links and the groups that have already formed cross-links.

[0174] Therefore, if a trifunctional polyol (e.g., glycerol) is used as an example, one hydroxyl group in one molecule forms a crosslink, and the remaining two hydroxyl groups do not participate in the crosslink. Therefore, in this case, the number of crosslinking groups is one. That is, in the case of a polyurethane resin-forming composition for a film sealing material containing a trifunctional polyol, the content of crosslinking groups derived from the trifunctional polyol means that the trifunctional polyol has one crosslinking group, and therefore has the same meaning as the content of the trifunctional polyol.

[0175] According to the second and third aspects of the present disclosure, there can be provided: a polyurethane resin forming composition which has low viscosity, excellent castability and is conducive to the formation of a polyurethane resin which can reduce the water dissolution amount of low molecular weight reactants of diphenylmethane diisocyanate and glycerin and the solvent dissolution amount of the molded product; and a membrane sealing material and a membrane assembly using the forming composition.

[0176] <Membrane sealing materials>

[0177] A film sealing material according to one aspect of the present disclosure includes a cured product of the polyurethane resin-forming composition for a film sealing material.

[0178] The film sealing material can be suitably formed by reacting and curing the isocyanate component constituting the polyisocyanate prepolymer (A) and the polyol component constituting the curing agent (B) at a temperature of 0°C to 100°C, preferably 20°C to 80°C, and more preferably 30°C to 60°C. Molding the film sealing material at a high temperature can shorten the gelation time, but since mold shrinkage is likely to occur, the addition of a catalyst can be used to lower the reaction temperature and suppress mold shrinkage.

[0179] <Membrane Module>

[0180] A membrane module according to one embodiment of the present disclosure includes:

[0181] Main body;

[0182] membrane; and,

[0183] a membrane sealing material for sealing the gap between the main body and the membrane;

[0184] The aforementioned film sealing material is the above-mentioned film sealing material.

[0185] Next, a membrane module according to one embodiment of the present disclosure will be described in further detail with reference to the drawings.

[0186] Figure 1 This is a conceptual diagram illustrating an example of the configuration of a membrane module according to one embodiment of the present disclosure.

[0187] Figure 1 The membrane module (hollow fiber membrane module) 100 shown includes a housing (main body) 11, the interior of which is filled with a plurality of hollow fiber membranes (membranes) 13. For example, in the case of a hollow fiber membrane module used as a dialyzer, several thousand to tens of thousands of hollow fiber membranes are filled.

[0188] The shell 11 has a cylindrical shape. Figure 1The membrane sealing material 19 is provided at the left and right ends of the hollow fiber membrane 13. The membrane sealing material fills and seals the gaps between the hollow fiber membranes 13 and the gaps between the hollow fiber membranes 13 and the inner wall of the housing 11, and bundles the plurality of hollow fiber membranes 13.

[0189] In addition, a first fluid inlet 15 and a first fluid outlet 17 are provided on the side of the shell 11, by means of which the first fluid (gas or liquid) flows in and out of the shell 11. The first fluid flowing in from the first fluid inlet 15 contacts the plurality of hollow fiber membranes 13 filled in the shell 11, and is discharged from the first fluid outlet 17 through the gaps therebetween (outside the hollow fiber membranes). It should be noted that there is no membrane sealing material 19 inside the hollow fiber membranes 13. Therefore, the second fluid (gas or liquid) flows in and out by means of a second inlet (one end side) and a second outlet (the other end side) of a cover member not shown in the figure provided in the hollow fiber membranes 13. Then, the first fluid and the second fluid are brought into contact with each other by means of the hollow fiber membranes 13, thereby generating a substance movement from one fluid to the other fluid (or further from the other fluid to the one fluid). For example, in the case of a hollow fiber membrane type dialyzer, the dialysate comes into contact with the blood, and waste products and excess water in the blood move into the dialysate.

[0190] It should be noted that Figure 1 The membrane assembly 100 shown is a structure having multiple hollow fiber membranes 13 and membrane sealing materials 19 sealing the gaps at both ends of the membranes, but the membrane assembly of this method is not limited to any of the above structures. For example, it can be a flat membrane, a spiral membrane, or other membranes having various shapes, multiple or single. In addition, the membrane sealing material is not limited to the structure provided at both ends of the membrane, and can be provided only at a part of the membrane (one end if it is a hollow fiber), or can be provided at all ends of the membrane, such as the entire outer edge of a flat membrane. Furthermore, the sealing material can be a structure provided at a part other than the end of the membrane and sealed. In addition, Figure 1 The housing 11 of the membrane module 100 shown has a cylindrical shape, but may have any shape other than a cylindrical shape.

[0191] The membrane assembly 100 seals the gaps between the hollow fiber membranes 13 at the end of the bundle of multiple hollow fiber membranes 13 using the polyurethane resin-forming composition of the above-mentioned membrane sealing material, and solidifies the composition to form the above-mentioned membrane sealing material (the gaps between the hollow fiber membranes are sealed by the membrane sealing material).

[0192] The membrane module according to one embodiment of the present disclosure can effectively reduce the amount of elution and is therefore suitable for use as a medical or water treatment module. Specifically, examples of the membrane module include plasma separators, artificial lungs, artificial kidneys, artificial livers, and domestic / industrial water treatment devices.

[0193] Hereinafter, the following [1] to

[11] show the aspects of the present disclosure.

[0194] [1]: A polyurethane resin-forming composition for a film sealing material, comprising a polyisocyanate prepolymer (A) and a curing agent (B),

[0195] The polyisocyanate prepolymer (A) comprises a reaction product of diphenylmethane diisocyanate (a1-1) and / or a modified diphenylmethane diisocyanate (a1-2) and an active hydrogen-containing compound (a2);

[0196] The curing agent (B) comprises castor oil polymer polyol (b1),

[0197] The castor oil polymer polyol (b1) comprises a castor oil polymer,

[0198] The content of the castor oil polymer is 1% by mass or more and 35% by mass or less relative to the total mass of the polyisocyanate prepolymer (A) and the curing agent (B).

[0199] [2]: The polyurethane resin-forming composition for a film sealing material according to [1], wherein

[0200] The curing agent (B) comprises:

[0201] Castor oil polymer polyol (b1),

[0202] At least one polyol (b2) selected from the group consisting of castor oil and castor oil-modified polyols, and

[0203] A hydroxyl-containing amine compound (b3) other than the aforementioned castor oil polymerized polyol (b1) and the aforementioned polyol (b2),

[0204] The content of the hydroxyl group-containing amine compound (b3) in the curing agent (B) is 30% by mass or less.

[0205] [3]: A polyurethane resin-forming composition for a film sealing material, comprising an allophanate group-containing polyisocyanate prepolymer (A') and a curing agent (B),

[0206] The allophanate group-containing polyisocyanate prepolymer (A') comprises a reaction product of diphenylmethane diisocyanate (a1-1) and an active hydrogen-containing compound (a2).

[0207] The curing agent (B) comprises castor oil polymer polyol (b1),

[0208] The castor oil polymer polyol (b1) comprises a castor oil polymer,

[0209] The crosslinking group density of the polyurethane resin-forming composition for a film sealing material is 0.65 mmol / g or more relative to the total mass of the allophanate group-containing polyisocyanate prepolymer (A′) and the curing agent (B).

[0210] [4]: The polyurethane resin-forming composition for a membrane sealing material according to [3], wherein the content of the castor oil polymer is 1% by mass or more and 35% by mass or less relative to the total mass of the allophanate group-containing polyisocyanate prepolymer (A') and the curing agent (B).

[0211] [5]: A polyurethane resin-forming composition for a film sealing material, comprising an allophanate group-containing polyisocyanate prepolymer (A') and a curing agent (B),

[0212] The allophanate group-containing polyisocyanate prepolymer (A') comprises a reaction product of diphenylmethane diisocyanate (a1-1) and an active hydrogen-containing compound (a2).

[0213] The curing agent (B) comprises castor oil polymer polyol (b1),

[0214] The castor oil polymer polyol (b1) comprises a castor oil polymer,

[0215] The content of the castor oil polymer is 1% by mass or more and 35% by mass or less relative to the total mass of the allophanate group-containing polyisocyanate prepolymer (A′) and the curing agent (B).

[0216] [6]: The polyurethane resin-forming composition for a film sealing material according to any one of [3] to [5], wherein

[0217] The curing agent (B) comprises:

[0218] Castor oil polymer polyol (b1),

[0219] At least one polyol (b2) selected from the group consisting of castor oil and castor oil-modified polyols, and

[0220] A hydroxyl-containing amine compound (b3) other than the aforementioned castor oil polymerized polyol (b1) and the aforementioned polyol (b2),

[0221] The content of the hydroxyl group-containing amine compound (b3) in the curing agent (B) is 35% by mass or less.

[0222] [7]: The polyurethane resin-forming composition for film sealing materials according to [1], [3], [4], [5] or [6], wherein

[0223] The aforementioned curing agent (B) comprises:

[0224] Castor oil polymerized polyol (b1), and

[0225] At least one polyol (b2) selected from the group consisting of castor oil and castor oil-modified polyols.

[0226] [8]: A film sealing material comprising a cured product of the polyurethane resin-forming composition for a film sealing material according to any one of [1] to [7].

[0227] [9]:A membrane module comprising:

[0228] Main body;

[0229] membrane; and,

[0230] a membrane sealing material for sealing the gap between the main body and the membrane;

[0231] The aforementioned membrane sealing material is the membrane sealing material described in [8].

[0232]

[10] : The membrane module according to [9], wherein

[0233] The aforementioned membrane is a plurality of hollow fiber membranes,

[0234] The membrane sealing material is used to seal a gap between at least a portion of the plurality of hollow fiber membranes and the main body portion, and at least a portion of a gap between the plurality of hollow fiber membranes.

[0235] Example

[0236] The present invention is further described in detail below with reference to Examples and Comparative Examples. However, the present invention is not limited to these Examples. It should be noted that "%" below refers to "mass %" unless otherwise specified.

[0237] The following components were used in Examples and Comparative Examples.

[0238] [Polyisocyanate prepolymer (A)]

[0239] a1-1; 4,4'-MDI (manufactured by Tosoh Corporation, product name: Millionate MT, isocyanate group content = 33.6%)

[0240] a1-2: A mixture of 2,4'-MDI and 4,4'-MDI (manufactured by Tosoh Corporation, product name: Millionate NM, isocyanate group content = 33.6%)

[0241] a1-3: Carbodiimide-modified 4,4′-MDI (manufactured by Tosoh Corporation, product name: Millionate MTL-C, isocyanate group content = 28.6%)

[0242] a1-4: Carbodiimide-modified 4,4′-MDI (manufactured by Tosoh Corporation, product name: Millionate MTL, isocyanate group content = 29.0%, crosslinking group density = 0.45 mmol / g)

[0243] a2-1: Castor oil fatty acid methyl ester (manufactured by Ito Oil Products Co., Ltd., product name COFA-MD, OHV = 160 mgKOH / g)

[0244] a2-2: Polypropylene glycol (manufactured by ADEKA Corporation, product name PP-1000, OHV = 111 mgKOH / g)

[0245] a2-3; Isotridecyl alcohol (manufactured by KH Neochem Co., Ltd., OHV = 275 mgKOH / g)

[0246] a2-4; 2-octyldodecanol (manufactured by Kao Corporation, product name KALKOL 200GD, hydroxyl value = 185 mgKOH / g)

[0247] a2-5: Castor oil (manufactured by Ito Oil Products Co., Ltd., product name URIC H-30, OHV = 160 mgKOH / g, viscosity (25°C) = 690 mPa·s, castor oil polymer content with a number average molecular weight of 1500 or more = 1% or less, crosslinking group density = 0.74 mmol / g)

[0248] a3-1; Zinc acetylacetonate (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0249] a3-2; 2-[{2-(dimethylamino)ethyl}methylamino]ethanol (manufactured by Tosoh Corporation, product name TOYOCAT RX5)

[0250] Active methylene compound; diethyl malonate (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0251] a4; Benzoyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0252] [Curing agent (B)]

[0253] b1-1: Castor oil polymer (manufactured by Ito Oil Manufacturing Co., Ltd., product name: Polycare Star #30, OHV = 155 mgKOH / g, viscosity (25°C) = 4800 mPa·s, castor oil polymer content with a number average molecular weight of 1500 or more = approximately 54%, crosslinking group density 1.84 mmol / g)

[0254] b1-2: Castor oil polymer (manufactured by Ito Oil Manufacturing Co., Ltd., product name: Polycare Star #10, OHV = 160 mgKOH / g, viscosity (25°C) = 2600 mPa·s, castor oil polymer content with a number average molecular weight of 1500 or more = approximately 43%)

[0255] b1-3; castor oil polymer

[0256] (Castor oil polymer obtained in Castor Oil Polymer Synthesis Example 1 below, OHV = 155 mgKOH / g, viscosity (25°C) = 8000 mPa·s, castor oil polymer content with a number average molecular weight of 1500 or more = about 65%)

[0257] b2-1: Castor oil (manufactured by Ito Oil Products Co., Ltd., product name URIC H-30, OHV = 160 mgKOH / g, viscosity (25°C) = 690 mPa·s, castor oil polymer content with a number average molecular weight of 1500 or more = 1% or less)

[0258] b2-2; ester of castor oil fatty acid and polypropylene glycol

[0259] (Ester obtained from the following diol synthesis example 1, OHV = 114 mgKOH / g)

[0260] b2-3: Partially dehydrated castor oil (manufactured by Ito Oil Products Co., Ltd. #1740U, OHV = 120 mgKOH / g, crosslinking group density = 0 mmol / g)

[0261] b3-1; N,N,N',N'-Tetrakis[2-hydroxypropyl]ethylenediamine

[0262] (Manufactured by ADEKA Corporation, product name EDP-300, OHV = 760 mgKOH / g, viscosity (25°C) = 50,000 mPa·s, crosslinking group density = 2.63 mmol / g)

[0263] b3-2: Ethylene oxide / propylene oxide = 4 / 6 mass ratio adduct of ethylenediamine (manufactured by ADEKA Corporation, product name BM-34, OHV = 820 mgKOH / g, viscosity (25°C) = 7500 mPa·s)

[0264] b3-3; N-lauryldiethanolamine (manufactured by Kao Corporation, product name AMIET 102, OHV = 394 mgKOH / g, viscosity (25°C) = 100 mPa·s)

[0265] <Castor Oil Polymer Synthesis Example 1>

[0266] A 2-liter four-necked flask equipped with a stirrer, thermometer, heater, and dropping funnel was charged with 1000 parts by mass of castor oil (URIC H-30, manufactured by Ito Oil Products Co., Ltd.) and heated to 140°C under a nitrogen stream. 160 parts by mass of di-tert-butyl peroxide was added dropwise over 30 minutes while purging with nitrogen. The temperature was then raised to 150°C and allowed to react for 4 hours. The decomposition product was then decompressed and recovered within 1 hour. White clay was added at 120°C and filtered for purification to obtain a castor oil polymer. The resulting castor oil polymer had a hydroxyl value of 155 mgKOH / g.

[0267] <Diol Synthesis Example 1>

[0268] A 1-liter four-necked flask equipped with a stirrer, thermometer, heater, and distillation column was charged with 596 parts by mass of ricinoleic acid (CO-FA, manufactured by Ito Oil Products, Ltd.) and 400 parts by mass of polypropylene glycol with a number average molecular weight of 400 (P-400, manufactured by Adeka Corporation). The mixture was heated to 190°C at 110°C for 2 hours under a nitrogen flow at atmospheric pressure, with the temperature increasing at a rate of 10°C / hour. The mixture was then reacted at 190°C for a further 2 hours, and water was distilled off. Subsequently, 0.05 parts by mass of tetrabutyl titanate (TBT-100, manufactured by Katayama Chemical Industry Co., Ltd.) was added. The nitrogen flow was stopped, and the pressure was gradually reduced to 5 kPa while maintaining the temperature at 190°C. Once the pressure reached 5 kPa, the mixture was allowed to react for a further 4 hours, and the generated water was distilled off to obtain the desired esterified product. The resulting esterified product had a hydroxyl value of 114 mgKOH / g.

[0269] [Preparation Examples 1 to 5 of Prepolymer (A)]

[0270] The raw materials a1 and b2 were added in the blending ratio shown in Table 1, and stirred and mixed at 70°C for 3 hours to react to synthesize prepolymers A-1 to A-5. The properties of the prepolymers are shown in Table 1.

[0271] [Table 1]

[0272]

Table 1

[0273]

[0274] [Preparation Examples 1 to 12 of Curing Agent (B)]

[0275] The raw materials b1, b2, and b3 were added according to the mixing ratio shown in Table 2, stirred, and uniformly mixed to obtain Preparation Examples 1 to 12. The properties of the raw materials are shown in Table 2.

[0276] [Table 2]

[0277]

Table 2

[0278]

[0279] [Examples 1 to 6, Comparative Examples 1 to 9]

[0280] Polyurethane resin compositions were molded according to the compositions shown in Tables 3 and 4.

[0281] The values ​​listed in Tables 3 and 4 were calculated from the following test results.

[0282] [NCO content determination]

[0283] In the prepolymers A-1 to A-5 shown in Table 1, the NCO content was determined in accordance with JIS K1603-1:2007.

[0284] [Determination of monomer content of MDI]

[0285] In the prepolymers A-1 to A-5 shown in Table 1, the content (mass %) of the MDI monomer was determined by GPC (Gel Permeation Chromatography) under the following conditions and method.

[0286] <GPC measurement conditions for isocyanate prepolymers>

[0287] (1) Measuring device: "HLC-8120 (trade name)" (manufactured by Tosoh Corporation)

[0288] (2) Column temperature: 40°C

[0289] (3) Detector: RI (refractive index)

[0290] (4) Column: Three columns filled with TSKgel G3000HXL, TSKgel G2000HXL, and TSKgel G1000HXL (all trade names, manufactured by Tosoh Corporation) as fillers were connected in series for measurement.

[0291] (5) Eluent: Tetrahydrofuran (THF) (flow rate: 1 mL / min, 40°C)

[0292] (6) Standard curve: The standard curve was obtained using the following grade of polystyrene (TSK standard POLYSTYRENE). 4)F-1(1.02×10 4 )A-5000(5.97×10 3 )A-2500(2.63×10 3 )A-500(Mw=6.82×10 2 , 5.78×10 2 ,4.74××10 2 , 3.70×10 2 , 2.66×10 2 )Toluene (Mw=92)

[0293] (7) Sample: 0.05 g of sample in 10 mL of THF

[0294] <Measurement method>

[0295] First, using polystyrene as a standard substance, a calibration curve was generated from a graph obtained by refractive index difference detection. Next, for each sample, based on the same calibration curve, the mass % of the peak near 230, representing the peak top molecular weight (number average molecular weight) of MDI monomer, was determined from a graph obtained by refractive index difference detection. The obtained content was used as the MDI monomer content (%).

[0296] [Determination of castor oil polymer content]

[0297] In the curing agents (B-1) to (B-12) shown in Table 2, the castor oil polymer content (mass %) was determined by GPC measurement according to the following conditions and method.

[0298] <GPC measurement conditions for curing agents>

[0299] (1) Measuring device: "HLC-8120 (trade name)" (manufactured by Tosoh Corporation)

[0300] (2) Column: Four columns each filled with two TSKgel G2000HXL and two TSKgel G3000HXL (both trade names, manufactured by Tosoh Corporation) as a filler were connected in series.

[0301] (3) Column temperature: 40°C

[0302] (4) Detector: RI (refractive index)

[0303] (5) Eluent: Tetrahydrofuran (THF) (flow rate: 1 mL / min, 40°C)

[0304] (6) Calibration curve: A calibration curve was obtained using the following trifunctional polypropylene polyols (all manufactured by Sanyo Chemical Industries, Ltd.).

[0305] "Sannix GP-250" (number average molecular weight = 250)

[0306] "Sannix GP-400" (number average molecular weight = 400)

[0307] "Sannix GP-600" (number average molecular weight = 600)

[0308] "Sannix GP-1000" (number average molecular weight = 1000)

[0309] "Sannix GP-3000" (number average molecular weight = 3000)

[0310] "Sannix GP-4000" (number average molecular weight = 4000)

[0311] "Sannix GP-5000" (number average molecular weight = 5000)

[0312] (7) Sample solution: 0.05 g sample in 10 mL THF

[0313] <Measurement method>

[0314] First, a calibration curve was generated using polystyrene as a standard substance, based on a plot obtained by refractive index difference detection. Next, for each sample, based on the same calibration curve, the mass % of the peak representing the peak top molecular weight of purified castor oil near 1000 was determined from a plot obtained by refractive index difference detection. For peaks other than purified castor oil with a molecular weight of 1500 or greater, the mass % of the purified castor oil was determined as the mass % of the castor oil polymer. In other words, the mass % of the castor oil polymer was determined as the mass % of the castor oil polymer.

[0315] [Preparation of samples for low molecular weight dissolution test]

[0316] (Examples 1 to 6, Comparative Examples 1 to 9)

[0317] The main agents (A-1) to (A-5) and curing agents (B-1) to (B-12) were mixed in the combinations shown in Tables 3 and 4 at a liquid temperature of 45°C and an isocyanate group / active hydrogen group ratio of 1.00 or 1.05 (molar ratio) to a total mass of 30 g to prepare a mixed solution. The obtained mixed solution was then stirred for 15 seconds. 10 g of glycerol (assuming the glycerol contained in the hollow fiber) was further added and stirred for 15 seconds to obtain a polyurethane resin cured product. The cured resin was allowed to stand in a thermostatic bath at a temperature of 50°C for 10 minutes as the primary aging condition, and at a temperature of 45°C for 2 days as the secondary aging condition.

[0318] [Low molecular weight extractables extraction test]

[0319] The low molecular weight eluate values ​​of the cured resins obtained in Examples 1 to 6 and Comparative Examples 1 to 9 were measured by the following method.

[0320] First, the low-molecular-weight dissolution value determination sample obtained in each embodiment and comparative example is cut into a fan shape, 20 g of each substance obtained is weighed, immersed in 100 ml of purified water preheated to 40 ° C, and placed at 40 ° C for 2 hours to extract the low-molecular-weight dissolution in the purified water. Then, the obtained extract is decanted, 10 ml is put into a 50 ml volumetric flask, and the liquid adjusted to 50 ml with purified water is used as a test liquid. Then, the UV absorbance of the test liquid is measured (manufactured by Shimadzu Corporation, product name UV-1500). The value of one-tenth of the maximum value of the absorbance at 240 to 245 nm is taken as the low-molecular-weight dissolution value. The low-molecular-weight dissolution value is preferably less than 0.07, more preferably less than 0.065.

[0321] [Mixed viscosity and pot life test]

[0322] In Examples 1 to 6 and Comparative Examples 1 to 9, the mixed viscosity / pot life when the resin cured products were obtained was determined by the following method.

[0323] The main agent and curing agent, which were pre-temperature-adjusted to 45°C, were measured and mixed in a total of 50 g in a formula of isocyanate group / active hydrogen group=1.00 (molar ratio) to obtain a mixture. Next, the viscosity of the mixture was measured using a rotational viscometer (type B, rotor No. 4) at 25°C. The viscosity after 60 seconds from the start of mixing the main agent and the curing agent was taken as the mixed viscosity, and the time until the viscosity of the mixture reached 50,000 mPa·s was taken as the pot life (seconds). If the mixed viscosity is 1,800 mPa·s or less, it is judged to be good in filling properties, and if the pot life is within 300 seconds, it is judged to be good in rapid curing properties.

[0324] [Hardness test]

[0325] The hardness of the cured resins obtained in Examples 1 to 6 and Comparative Examples 1 to s was measured by the following method.

[0326] The JIS-D hardness of the measurement samples obtained in each of the Examples and Comparative Examples was measured at 25° C. by a method according to JIS-K7312 at the moment of measurement and 10 seconds after the moment of measurement.

[0327] [Appearance evaluation]

[0328] The polyurethane resin-forming compositions for film sealing materials based on the combinations shown in Tables 3 and 4 were degassed at 10-20 kPa for 3 minutes and then injected into a stainless steel mold (100 mm × 100 mm × 8 mm). After aging at 45°C for 2 days, the molds were removed to obtain cured products. The resulting cured products were visually evaluated for appearance, with A being the case for no turbidity, B for slight turbidity and insufficient curing, and C for white turbidity.

[0329] [Whiteness evaluation]

[0330] The whiteness of the cured product used in the appearance evaluation was measured. The results are shown in Tables 3 and 4. It should be noted that the whiteness was measured in accordance with JIS-P8123. A whiteness of 7.0 or less is preferred, and 5.0 or less is more preferred.

[0331] [Hardness evaluation]

[0332] The cured product used for the appearance evaluation was measured for Shore D hardness at 25° C. The results are shown in Tables 3 and 4. The hardness was measured in accordance with JIS K 7312:1996.

[0333] [Molding shrinkage]

[0334] Polyurethane resin-forming compositions for film sealing materials based on the combinations shown in Tables 3 and 4 were degassed at 10-20 kPa for 1 minute and then injected into a stainless steel ring mold (approximately 60 mm φ x 10 mm H). They were aged for 1 hour at 45°C. Subsequently, they were aged for 2 days at 25°C. The shrinkage rate was measured using the ring dimensions as the initial value.

[0335]

[0336] [Table 3]

[0337]

Table 3

[0338]

[0339] [Table 4]

[0340]

Table 4

[0341]

[0342] ※1Cannot be measured due to insufficient curing

[0343] [Production Examples 1 to 8]

[0344] (Production Example 1: Production of Main Agent (A-9))

[0345] A 2-liter four-necked flask was charged with 193 g of a1-1 and 450 g of a1-2. The temperature was adjusted to 50°C while stirring under a nitrogen stream. Subsequently, 269 g of a2-1 and 88 g of a2-2 were added while stirring. After the exothermic heat of the urethanization reaction subsided, the temperature was raised to 90°C. After the internal temperature stabilized at 90°C, 10.1 g of catalyst a3- was added, and the reaction was continued at 90°C for 4 hours. The reaction was terminated by adding 0.14 g of catalyst poison a4 to obtain an isocyanate-terminated prepolymer. This isocyanate-terminated prepolymer is hereinafter referred to as "main component (A-9)." The isocyanate group (NCO) content of the obtained main component (A-9) was 13.5% by mass, and the viscosity at 25°C was 3330 mPa·s.

[0346] (Production Examples 10, 12 to 14)

[0347] The isocyanate component and polyol component were changed to the compositions shown in Table 5, and prepolymers were synthesized in the same manner as in Production Example 1. The resulting prepolymers were all pale yellow, transparent liquids with low viscosities. These prepolymers are referred to below as main agents (A-10), (A-12) to (A-14). The properties of the main agents (A-10), (A-12) to (A-14) are shown in Table 5.

[0348] [Production Example 3]

[0349] (Production Example 3: Production of Main Agent (A-11))

[0350] To a 2-liter four-necked flask, add 231 g of a1-1 and 538 g of a1-2, and adjust the temperature to 50°C while stirring under a nitrogen stream. Then, add 231 g of a2-3 while stirring. After the exothermic heat of the urethanization reaction subsides, raise the temperature to 110°C. After the internal temperature stabilizes at 110°C, add the specified amounts (see the values ​​in the table) of an active methylene compound and catalyst a3-2 in sequence to initiate the allophanation reaction. The internal liquid is sampled and the NCO content is measured while the reaction is continued. When the NCO content reaches 16.1%, the specified amount (see the values ​​in the table) of catalyst poison a4 is added at the predicted time to terminate the reaction, yielding a polyisocyanate composition containing an allophanate-modified product. This polyisocyanate composition is hereinafter referred to as the main agent (A-11). The main agent (A-11) is a light yellow, transparent liquid with a viscosity of 3630 mPa·s at 25°C.

[0351] (Production Example 7: Production of Main Agent (A-15))

[0352] In a 1-liter four-necked flask, 300 g of a1-1 and 300 g of a1-2 were added and stirred under a nitrogen stream while adjusting the temperature to 50°C. Subsequently, 400 g of a2-5 was added while stirring. After the exothermic heat of the urethanization reaction subsided, the mixture was reacted at 75°C for 3 hours to obtain a prepolymer. This prepolymer is hereinafter referred to as the main agent (A-15). The main agent (A-15) was a light yellow, transparent liquid with a viscosity of 3750 mPa·s at 25°C. Its properties are shown in Table 5.

[0353] [Manufacturing Example 8: Manufacture of Main Agent (A-16)]

[0354] a1-3 (carbodiimide-modified 4,4′-MDI, Millionate MTL-C manufactured by Tosoh Corporation) was used as the main agent (A-16). Table 5 shows the properties of the main agent (A-16).

[0355] [Calculation method of cross-linking group density]

[0356] The crosslinking group density shown in Tables 5 and 6 to 8 was calculated using the following formula from the number average molecular weight obtained by GPC measurement and the number of functional groups and hydroxyl value disclosed by each raw material manufacturer. Note that GPC measurement was performed according to the "GPC Measurement Conditions for Curing Agents" described below.

[0357]

[0358] [Table 5]

[0359] [Table 5]

[0360]

[0361] [Preparation Examples 13 to 24 of Curing Agent (B)]

[0362] The raw materials b1, b2, b3, and a2 were added in the mixing ratios shown in Table 6, stirred, and uniformly mixed to obtain curing agents (B-13) to (B-24). The properties of curing agents (B-13) to (B-24) are shown in Table 6.

[0363] [Table 6]

[0364]

Table 6

[0365]

[0366] [Examples 8 to 17, Comparative Examples 10 to 18]

[0367] In Examples 8 to 17 and Comparative Examples 10 to 18, polyurethane resin compositions were molded according to the compositions shown in Tables 7 and 8.

[0368] The values ​​listed in Tables 7 and 8 were calculated from the following test results.

[0369] Incidentally, the NCO content measurement, the MDI monomer content measurement, the castor oil polymer content measurement, and the appearance evaluation were carried out in the same manner as in Examples 1 to 7 and Comparative Examples 1 to 9.

[0370] [Preparation of samples for methanol extraction test]

[0371] (Examples 8 to 17, Comparative Examples 10 to 18)

[0372] The base agents (A-9) to (A-16) and curing agents (B-13) to (B-24) were prepared using the combinations shown in Tables 7 and 8. 60 g of the base agent and 40 g of the curing agent were immediately measured in a 500 ml polycup at a liquid temperature of 25°C or 45°C and an isocyanate group / active hydrogen group molar ratio of 1.00 or 1.05. Mixing was performed with a spatula for 30 seconds, followed by vacuum degassing at 50 mmHg for 60 seconds. The degassed mixture was spread onto release paper to form a 1 mm thick sheet, which was then allowed to stand in a thermostatic chamber at 45°C for 2 days.

[0373] [Methanol extraction test]

[0374] The low molecular weight eluate values ​​of the cured resins obtained in Examples 8 to 17 and Comparative Examples 10 to 18 were measured by the following method.

[0375] First, the methanol extraction samples obtained in each Example and Comparative Example were cut into 10 mm squares. Next, 20 g of the cut sample and 200 g of methanol were placed in a 500 ml sample bottle, sealed, and shaken at 25°C for 24 hours. After shaking, the extract was further filtered and collected in a 300 ml eggplant-shaped bottle, then evaporated to dryness. The methanol extraction yield was then calculated using the following formula.

[0376] Methanol extraction rate (%) = {mass of the eggplant-shaped bottle after evaporation (g) - mass of the empty eggplant-shaped bottle (g)} / sample mass (g) × 100

[0377] The methanol extraction rate is preferably less than 1.0%.

[0378] [Preparation of samples for low molecular weight dissolution test]

[0379] (Examples 8 to 17, Comparative Examples 10 to 18)

[0380] The main agents (A-9) to (A-16) and curing agents (B-13) to (B-24) were mixed in the combinations shown in Tables 7 and 8 at a liquid temperature of 25°C or 45°C and an isocyanate group / active hydrogen group ratio of 1.00 or 1.05 (molar ratio) to give a total mass of 30 g to prepare a mixed solution. The obtained mixed solution was then stirred for 15 seconds. 10 g of glycerol (assuming the glycerol contained in the hollow fiber) was further added and stirred for 15 seconds to obtain a polyurethane resin cured product. The cured resin was allowed to stand in a thermostatic bath at a temperature of 50°C for 10 minutes as the primary aging condition, and at a temperature of 45 degrees for 2 days as the secondary aging condition.

[0381] [Low molecular weight extractables extraction test]

[0382] The low molecular weight eluate values ​​of the cured resins obtained in Examples 8 to 17 and Comparative Examples 10 to 18 were measured by the following method.

[0383] First, the low-molecular-weight dissolution value determination sample obtained in each embodiment and comparative example is cut into a fan shape, 20 g of each substance obtained is weighed, immersed in 100 ml of purified water preheated to 40 ° C, and placed at 40 ° C for 2 hours to extract the low-molecular-weight dissolution in the purified water. Then, the obtained extract is decanted, 10 ml is put into a 50 ml volumetric flask, and the liquid adjusted to 50 ml with purified water is used as a test liquid. Then, the UV absorbance of the test liquid is measured (manufactured by Shimadzu Corporation, product name UV-1500). The value of one-tenth of the maximum value of the absorbance at 240 to 245 nm is taken as the low-molecular-weight dissolution value. The low-molecular-weight dissolution value is preferably less than 0.07, more preferably less than 0.065.

[0384] [Mixed viscosity and pot life test]

[0385] In Examples 8 to 17 and Comparative Examples 10 to 18, the mixed viscosity and pot life of the obtained resin cured products were determined by the following method.

[0386] The main agent and curing agent, which were pre-temperature adjusted to 25°C or 45°C, were measured and mixed in a total of 50 g according to a formula of isocyanate group / active hydrogen group = 1.00 (molar ratio) or 1.05 (molar ratio) to obtain a mixture. Then, the viscosity of the mixture was measured using a rotational viscometer (type B, rotor No. 4) at 25°C. The viscosity after 60 seconds from the start of mixing the main agent and the curing agent was taken as the mixed viscosity, and the time until the viscosity of the mixture reached 50,000 mPa·s was taken as the pot life (seconds). If the mixed viscosity is less than 1,800 mPa·s and the pot life is within 1,800 seconds, it is judged that the filling property is good, and if the pot life is within 300 seconds, it is judged that the fast curing property is good.

[0387] [Hardness evaluation]

[0388] The cured product used for the appearance evaluation was measured for Shore D hardness at 25° C. The results are shown in Tables 7 and 8. The hardness was measured in accordance with JIS K 7312:1996.

[0389] [Table 7]

[0390]

Table 7

[0391]

[0392] [Table 8]

[0393]

Table 8

[0394]

[0395] According to one embodiment of the present disclosure, a polyurethane resin-forming composition having excellent moldability, suppressing the dissolution of low-molecular-weight reaction products of MDI and glycerin, and facilitating the formation of a polyurethane resin having an excellent appearance, as well as a membrane sealing material and a membrane module using the composition can be provided. Therefore, the membrane sealing material according to one embodiment of the present disclosure can be suitably used as a membrane sealing material for medical and industrial separation devices.

[0396] According to another embodiment of the present disclosure, a polyurethane resin-forming composition having low viscosity, excellent castability, and advantageous for forming a polyurethane resin capable of reducing the amount of water-soluble low-molecular-weight reactants of diphenylmethane diisocyanate and glycerin and the amount of solvent-soluble molded products can be provided, as well as a sealing material and membrane assembly using the forming composition. Therefore, the membrane sealing material according to another embodiment of the present disclosure can be suitably used as a membrane sealing material for medical and industrial separation devices.

[0397] While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention.

[0398] It should be noted that the entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2019-136226 filed on July 24, 2019, and the entire contents of the specification, claims, drawings, and abstract of Japanese Patent Application No. 2020-008738 filed on January 22, 2020 are incorporated herein and cited as disclosures of the specifications of the present invention.

[0399] Description of Reference Numerals

[0400] 11 Housing

[0401] 13 Hollow fiber membrane

[0402] 15 1st fluid inlet

[0403] 17 1st fluid outlet

[0404] 19 Membrane sealing material

[0405] 100 membrane modules (hollow fiber membrane modules)

Claims

1. A polyurethane resin-forming composition for a film sealing material, comprising a polyisocyanate prepolymer (A) and a curing agent (B), 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); The curing agent (B) comprises: Castor oil polymer polyol (b1), the castor oil polymer polyol (b1) comprising a castor oil polymer, at least one polyol (b2) selected from the group consisting of castor oil and castor oil-modified polyols, and A hydroxyl-containing amine compound (b3) other than the castor oil polymerized polyol (b1) and the polyol (b2), The content of the hydroxyl-containing amine compound (b3) in the curing agent (B) is 5% by mass or more and 30% by mass or less, The content of the castor oil polymer is 1% by mass or more and 35% by mass or less relative to the total mass of the polyisocyanate prepolymer (A) and the curing agent (B).

2. A polyurethane resin-forming composition for a film sealing material, comprising an allophanate group-containing polyisocyanate prepolymer (A') and a curing agent (B), The allophanate-containing polyisocyanate prepolymer (A') contains a reaction product of diphenylmethane diisocyanate (a1-1) and an active hydrogen-containing compound (a2). The curing agent (B) comprises: Castor oil polymer polyol (b1), the castor oil polymer polyol (b1) comprising a castor oil polymer, at least one polyol (b2) selected from the group consisting of castor oil and castor oil-modified polyols, and A hydroxyl-containing amine compound (b3) other than the castor oil polymerized polyol (b1) and the polyol (b2), The content of the hydroxyl-containing amine compound (b3) in the curing agent (B) is 5% by mass or more and 35% by mass or less, The crosslinking group density of the polyurethane resin-forming composition for a film sealing material is 0.65 mmol / g or more relative to the total mass of the allophanate group-containing polyisocyanate prepolymer (A′) and the curing agent (B).

3. The polyurethane resin-forming composition for a film sealing material according to claim 2, wherein The content of the castor oil polymer is 1% by mass or more and 35% by mass or less relative to the total mass of the allophanate group-containing polyisocyanate prepolymer (A′) and the curing agent (B).

4. A polyurethane resin-forming composition for a film sealing material, comprising an allophanate group-containing polyisocyanate prepolymer (A') and a curing agent (B), The allophanate-containing polyisocyanate prepolymer (A') contains a reaction product of diphenylmethane diisocyanate (a1-1) and an active hydrogen-containing compound (a2). The curing agent (B) comprises: Castor oil polymer polyol (b1), the castor oil polymer polyol (b1) comprising a castor oil polymer, at least one polyol (b2) selected from the group consisting of castor oil and castor oil-modified polyols, and A hydroxyl-containing amine compound (b3) other than the castor oil polymerized polyol (b1) and the polyol (b2), The content of the hydroxyl-containing amine compound (b3) in the curing agent (B) is 5% by mass or more and 35% by mass or less, The content of the castor oil polymer is 1% by mass or more and 35% by mass or less relative to the total mass of the allophanate group-containing polyisocyanate prepolymer (A′) and the curing agent (B). 5 . A film sealing material comprising a cured product of the polyurethane resin-forming composition for a film sealing material according to claim 1 .

6. A membrane module comprising: Main body; membrane; and, a membrane sealing material for sealing the gap between the main body and the membrane, The film sealing material is the film sealing material according to claim 5.

7. The membrane module according to claim 6, wherein The membrane is a plurality of hollow fiber membranes, The membrane sealing material is used to seal a gap between at least a portion of the plurality of hollow fiber membranes and the main body portion, and at least a portion of a gap between the plurality of hollow fiber membranes.

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