JP7286912B2 - Allophanate group-containing polyisocyanate prepolymer - Google Patents

Description

TECHNICAL FIELD The present invention relates to an allophanate group-containing polyisocyanate prepolymer, a polyurethane resin-forming composition using the same, and a sealing material and a membrane module using the forming composition.

A polyisocyanate prepolymer containing allophanate groups derived from diphenylmethane diisocyanate (hereinafter referred to as MDI) and an alcohol component has low viscosity and little MDI monomer precipitation at low temperatures, and is easy to handle. It is useful and widely applied in the field of agents and sealants.

Aliphatic monoalcohols and polypropylene glycol monoalkyl ethers are known as alcohol components to be reacted with MDI (see, for example, Patent Document 1). However, the resulting allophanate group-containing polyisocyanate prepolymer has poor defoaming properties, and even if the polyol component is blended and the pressure is reduced, the bubbles cannot be removed completely, so many air bubbles remain in the cured product, and the original performance of the urethane resin is lost. The problem was that I didn't get it.

Japanese Patent Application Laid-Open No. 2009-30059

Embodiments of the present invention have been made in view of the background art described above, and the object thereof is a low-viscosity and good defoaming MDI-based allophanate group-containing polyisocyanate prepolymer, and using the prepolymer An object of the present invention is to provide a polyurethane resin-forming composition, a sealing material, and a membrane module.

The present inventors have made intensive studies to solve the above problems, and as a result, have found that the above problems can be solved by using a ricinoleic acid ester as a monool component, and have completed the present invention.

That is, the present invention includes embodiments [1] to [11] below.
[1] A reaction product of diphenylmethane diisocyanate (A), an ester (B), and a polyol (E), wherein the ester (B) comprises ricinoleic acid (B-1) and an alcohol ( B-2) and an allophanate group-containing polyisocyanate prepolymer (F), which is an esterified product of B-2).
[2] The allophanate group-containing polyisocyanate prepolymer (F) according to the above [1], wherein the ester compound (B) has an average functional group number of less than 2.
[3] The allophanate group-containing polyisocyanate prepolymer (F) according to [1] or [2] above, wherein the alcohol (B-2) is a monool having a molecular weight of 32 or more.
[4] The allophanate group-containing polyol according to any one of [1] to [3], wherein the alcohol (B-2) is a polypropylene glycol monoalkyl ether having a molecular weight of 200 or more and 2000 or less. Isocyanate prepolymer (F).
[5] The allophanate group-containing polyisocyanate prepolymer (F) according to any one of [1] to [4] above, which has a viscosity of 2,000 mPa·s or less at 25°C.
[6] The above [1] to [5], wherein the reaction product is a reaction product of the diphenylmethane diisocyanate (A), the ester compound (B), and the polyol (E). Allophanate group-containing polyisocyanate prepolymer (F) according to any one of the above.
[7] The allophanate group-containing polyisocyanate prepolymer according to [6] above, wherein the polyol (E) has an average functional group number of 2 or more.
[8] The allophanate group-containing polyisocyanate prepolymer (F) according to the above [6] or [7], wherein the polyol (E) has a molecular weight of 500 or more and 3000 or less.
[9] A polyurethane resin-forming composition comprising the allophanate group-containing isocyanate prepolymer (F) according to any one of [1] to [8] above and a polyol (G).
[10] A sealing material comprising a cured product of the polyurethane resin-forming composition described in [9] above.
[11] A membrane module sealed with the sealing material according to [10] above.

The allophanate group-containing polyisocyanate prepolymer according to one embodiment of the present invention provides a cured urethane resin having a low viscosity, good defoaming properties, and excellent appearance. According to another embodiment of the present invention, it is possible to obtain a polyurethane resin-forming composition that contributes to the formation of a cured urethane resin having an excellent appearance. According to another embodiment of the present invention, a sealing material and a membrane module with excellent appearance are obtained.

1 is a conceptual diagram showing an example of the configuration of a membrane module according to one embodiment of the present invention; FIG.

The polyisocyanate prepolymer (F) containing allophanate groups according to one embodiment of the present invention is
Diphenylmethane diisocyanate (hereinafter referred to as MDI) (A);
an ester (B) of ricinoleic acid (B-1) and an alcohol (B-2);
and is characterized by low viscosity and excellent defoaming properties.

The inventors of the present invention conducted further studies on the polyurethane resin-forming composition containing the polyisocyanate prepolymer (F), and found that when the composition is cured to obtain a cured product, it may be eluted into the solvent. I found out. If the cured product is eluted into the solvent, it may lead to deterioration in performance, shortening of life, etc. Therefore, it is desirable to reduce the amount of extracts extracted by the solvent.

As a result of extensive studies by the present inventors, the polyisocyanate prepolymer (F) is a reaction product of a system to which a polyol (E) is further added, thereby forming a polyurethane resin containing the reaction product. It was found that the cured product obtained by curing the composition has a reduced amount of extractables extracted by the solvent.
Therefore, the polyisocyanate prepolymer (F) containing allophanate groups according to another embodiment of the present invention is
an MDI (A);
an ester (B) of ricinoleic acid (B-1) and an alcohol (B-2);
It is a reaction product of polyol (E).

Commonly available MDI monomer or polymeric MDI can be used for MDI (A). Specific examples of the MDI monomer include 2,2′-MDI in an amount of 0% by mass to 5% by mass, 2,4′-MDI in an amount of 0% by mass to 95% by mass, and 4,4′-MDI in an amount of 5% by mass. % or more and 100 mass % or less of the MDI monomer alone or an isomer mixture. Polymethylene polyphenylene polyisocyanate can also be used as polymeric MDI. It is also possible to use a mixture of MDI monomer and polymeric MDI, in which case the polymeric MDI content is preferably 0% by mass or more and 50% by mass or less in the isocyanate component used. If it exceeds 50% by mass, the viscosity becomes too high, and insoluble matter tends to be generated.

Esterified product (B) is an esterified product of ricinoleic acid (B-1) and alcohol (B-2). Among them, the average number of functional groups of the ricinoleic acid ester (B) is preferably less than 2 from the viewpoint of obtaining an allophanate group-containing polyisocyanate prepolymer having low viscosity and excellent fluidity.

The ricinoleic acid (B-1) used here is ricinoleic acid alone or a fatty acid mixture containing 50% by mass or more of ricinoleic acid. Among them, 85% by mass or more and 95% by mass or less of ricinoleic acid obtained by saponifying and decomposing castor oil because of its easy availability, and other fatty acids such as oleic acid, linoleic acid, palmitic acid, stearic acid, and hydroxystearic acid. It is preferred to use castor oil fatty acids containing

On the other hand, the alcohol (B-2) is not particularly limited, and examples include methanol, ethanol, 1- and 2-propanol, 1- 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 Nol, 1-hexadecanol, 1-heptadecanol, 1-octadecanol, 1-nonadecanol, 1-eicosanol, 1-hexacosanol, 1-heptatricontanol, 1-oleyl alcohol, 2-octyldodecanol and mixtures thereof. In addition to these aliphatic alcohols, polyalkylene glycol monoalkyl/aryl ethers, mixtures thereof, etc., which are oxyalkylene adducts initiated by compounds containing phenolic hydroxyl groups such as phenol, cresol, xylenol, nonylphenol, etc. is mentioned. Further, monocarboxylic acid esters of polyalkylene glycol, mixtures thereof, and the like are included.

Among these alcohols (B-2), it is preferable to use monools having a molecular weight of more than 32 in order to develop excellent defoaming properties. It is preferable to use an alcohol having 4 or more carbon atoms such as oleyl alcohol, or a polypropylene glycol monoalkyl ether having a molecular weight of 200 or more and 2000 or less.

Esterified product (B) can be synthesized by a known method. For example, there is a method of dehydration condensation of castor oil fatty acid and alcohol (B-2), and a method of removing glycerin while subjecting castor oil and alcohol (B-2) to transesterification. can be used.

Any polyol (E) having an average number of functional groups of 2 or more can be used. From the viewpoint of moldability of the polyurethane resin and reduction of extractables, the average number of functional groups is more preferably 2 or more and 3 or less.

Examples of the polyol (E) include polyether-based polyols, polyester-based polyols, polylactone-based polyols, castor oil-based polyols, and polyolefin-based polyols. These can be used alone or in combination of two or more. Among these, castor oil-based polyols are preferable because they are excellent in chemical resistance and elution resistance.

The molecular weight of the polyol (E) is preferably 500 or more and 3000 or less. The molecular weight of the polyol (E) is more preferably 600 or more and 2500 or less from the viewpoint of excellent molding processability and adhesive strength of the polyurethane resin.

Moreover, the viscosity of the allophanate group-containing polyisocyanate prepolymer (F) at 25° C. is preferably 2,000 mPa·s or less from the viewpoint of workability.

The allophanate group-containing polyisocyanate prepolymer (F) comprises MDI (A), an ester (B) of ricinoleic acid (B-1) and alcohol (B-2), and a polyol (E) with an allophanate-forming catalyst. It can be produced by reacting in the presence of (C) and then adding catalyst poison (D) to terminate the reaction. At this time, in addition to the esterified product (B), a compound containing a hydroxyl group having an average functional group number of 1 to 2, that is, a monool or a diol can be used in combination. However, a compound containing a phenolic hydroxyl group may have a higher production rate of isocyanurate groups and thus a higher viscosity, so a compound containing a hydroxyl group other than a phenolic hydroxyl group is preferred. Polyols higher than triols may also increase viscosity.

A known catalyst can be used as the allophanate-forming catalyst (C). For example, zinc acetylacetonate, zinc 2-ethylhexanoate, cobalt 2-ethylhexanoate, zinc such as cobalt naphthenate, metal carboxylates such as lead, tin, copper, cobalt, and hydrates thereof can be used. can be done.

Also usable are tertiary amines, tertiary amino alcohols, quaternary ammonium salts and mixtures thereof.

Examples of tertiary amines include N,N,N-benzyldimethylamine, N,N,N-dibenzylmethylamine, N,N,N-cyclohexyldimethylamine, N-methylmorpholine, N,N,N- trialkylamines such as tribenzylamine, N,N,N-tripropylamine, N,N,N-tributylamine, N,N,N-tripentylamine, N,N,N-trihexylamine; N, polymethylpolyalkylenepolyamines such as N,N',N'-tetramethylethylenediamine and N,N,N',N',N''-pentamethyldiethylenetriamine;

Examples of tertiary amino alcohols include 2-(dimethylamino)ethanol, 3-(dimethylamino)propanol, 2-(dimethylamino)-1-methylpropanol, 2-{2-(dimethylamino)ethoxy}ethanol, 2 -{2-(diethylamino)ethoxy}ethanol, 2-[{2-(dimethylamino)ethyl}methylamino]ethanol and the like.

Examples of quaternary ammonium salts include N,N,N,N,-tetramethylammonium, tetraalkylammonium such as N,N,N-trimethyl-N-octylammonium, N-(2-hydroxyethyl)-N, A compound obtained by combining a hydroxyalkyltrialkylammonium such as N,N-trimethylammonium and N-(2-hydroxypropyl)-N,N,N,-trimethylammonium with a counterion can be used.

The amount of the allophanate-forming catalyst (C) added is preferably 1 ppm or more and 1000 ppm or less, more preferably 10 ppm or more and 500 ppm or less, relative to the total amount of the polyisocyanate prepolymer (F). When it is 1 ppm or more, the reaction proceeds more rapidly, and when it is 1000 ppm or less, coloring of the prepolymer is suppressed to a higher degree, which is preferable.

Although the reaction temperature for allophanatization is not particularly limited, it is preferably 20° C. or higher and 200° C. or lower. In particular, the temperature is preferably 60° C. or higher and 160° C. or lower in order to suppress the proportion of isocyanurate produced as a by-product to 20 mol % or less and to obtain a low-viscosity allophanate group-containing prepolymer.

The catalyst poison (D) is not particularly limited as long as it is an acidic substance. Also included are Lewis acids and the like. The amount to be added is preferably equivalent to or more than the number of moles of the allophanate-forming catalyst (C), and more preferably 1.0 to 1.5 times the molar equivalent.

The polyol (G) is not particularly limited as long as it can react with the allophanate group-containing polyisocyanate prepolymer (F) to form a urethane resin-forming composition, and any active hydrogen group-containing compound can be used. Either can be used.

Examples of the polyol (G) include low-molecular-weight polyols, polyether-based polyols, polyester-based polyols, polylactone-based polyols, castor-oil-based polyols, polyolefin-based polyols, and hydroxyl group-containing amine-based compounds. These can be used alone or in combination of two or more. Among these, castor oil-based polyols are preferable because they are excellent in chemical resistance and elution resistance.

Low-molecular-weight polyols include, for example, divalent low-molecular-weight polyols and trivalent or higher-molecular-weight low-molecular-weight polyols. Specific examples of divalent low-molecular-weight polyols include ethylene glycol, diethylene glycol, propylene glycol, 1,2-, 1,3- or 1,4-butanediol, 1,5-pentanediol, 3-methyl- 1,5-pentanediol, 1,6-hexane glycol, 1,8-octanediol, 1,10-decanediol, neopentyl glycol, hydrogenated bisphenol A and the like. Specific examples of trivalent or higher low-molecular-weight polyols include glycerin, trimethylolpropane, hexanetriol, pentaerythritol, and sorbitol. The molecular weight of the low-molecular-weight polyol is preferably 50 or more and 200 or less from the viewpoint of excellent molding processability during the production of the sealing material.

Examples of polyether-based polyols include adducts of alkylene oxides (alkylene oxides having 2 to 4 carbon atoms, such as ethylene oxide, propylene oxide, butylene oxide, etc.) of the above low-molecular-weight polyols, ring-opening polymers of alkylene oxides, and the like. be done. Specific examples of polyether-based polyols include polypropylene glycol, polyethylene glycol, polytetramethylene ether glycol, and tipped ethers which are copolymers of ethylene oxide and propylene oxide. The number average molecular weight of the polyether-based polyol is preferably 200 or more and 7,000 or less. The number average molecular weight of the polyether-based polyol is more preferably 500 or more and 5000 or less from the viewpoint of excellent molding processability during the production of the sealing material.

Polyester-based polyols include, for example, polyester-based polyols obtained by condensation polymerization of polycarboxylic acids and polyols. More specifically, the polycarboxylic acids include aliphatic saturated or unsaturated polycarboxylic acids such as azelaic acid, dodecanoic acid, maleic acid, fumaric acid, itaconic acid, ricinoleic acid, dimerized linoleic acid; aromatic polycarboxylic acids. , for example, phthalic acid, isophthalic acid, terephthalic acid, and the like. More specific examples of the polyol include at least one selected from the group consisting of the above low-molecular-weight polyols and the above polyether-based polyols. The number average molecular weight of the polyester polyol is preferably 200 or more and 5000 or less. From the viewpoint of excellent molding processability during production of the sealing material, the number average molecular weight of the polyester-based polyol is more preferably 500 or more and 3000 or less.

Polylactone-based polyols include polymerization initiators such as glycols and triols, ε-caprolactone, α-methyl-ε-caprolactone, ε-methyl-ε-caprolactone, and β-methyl-σ-valerolactone. Polyols obtained by addition polymerization of at least one selected from the group consisting of organometallic compounds, metal chelate compounds, and fatty acid metal acyl compounds in the presence of catalysts. The number average molecular weight of the polylactone-based polyol is preferably 200 or more and 5000 or less. From the viewpoint of excellent molding processability during production of the sealing material, the number average molecular weight of the polylactone-based polyol is more preferably 500 or more and 3000 or less.

Castor oil-based polyols include linear or branched polyesters obtained by reaction of castor oil fatty acids with polyols, such as diglycerides, monoglycerides of castor oil fatty acids; mono-, di- or triesters of castor oil fatty acids with trimethylolalkanes; mono-, di-, or tri-esters of castor oil fatty acid and polypropylene glycol; More specifically, the polyol includes at least one selected from the group consisting of the above low-molecular-weight polyols and the above polyether-based polyols. The castor oil-based polyol preferably has a number average molecular weight of 300 or more and 4,000 or less. From the viewpoint of excellent molding processability during production of the sealing material, the number average molecular weight of the castor oil-based polyol is more preferably 500 or more and 3000 or less.

Examples of polyolefin-based polyols include polybutadiene-based polyols obtained by introducing hydroxyl groups at the terminals of polybutadiene or copolymers of butadiene and styrene or acrylonitrile.

Other examples include polyetherester-based polyols obtained by subjecting a polyester having at least one terminal selected from the group consisting of a carboxyl group and a hydroxyl group to an addition reaction with an alkylene oxide such as ethylene oxide or propylene oxide.

Examples of hydroxyl group-containing amine compounds include oxyalkylated derivatives of amino compounds such as aminoalcohols.

Examples of amino alcohols include N,N,N',N'-tetrakis[2-hydroxypropyl]ethylenediamine, N,N,N',N, which are propylene oxide or ethylene oxide adducts of amino compounds such as ethylenediamine. '-tetrakis[2-hydroxyethyl]ethylenediamine and the like; mono-, di- and triethanolamine, N-methyl-N,N'-diethanolamine and the like. Among these, propylene oxide or ethylene oxide adducts of amino compounds such as ethylenediamine are preferred, and N,N,N',N'-tetrakis[2-hydroxypropyl]ethylenediamine is more preferred. By using N,N,N',N'-tetrakis[2-hydroxypropyl]ethylenediamine, excellent effects such as improvement of processability during molding and suppression of extractables can be obtained.

In addition, when the hydroxyl group-containing amine compound is used, the compounding amount thereof in the polyol (G) is preferably in the range of 1% by mass to 30% by mass, and particularly preferably in the range of 5% by mass to 25% by mass. When the proportion of the hydroxyl group-containing amine compound in the polyol (G) is 1% by mass or more, the hydroxyl group-containing amine compound more satisfactorily exhibits its function, and further effects are exhibited. When the proportion of the hydroxyl group-containing amine compound in the polyol (G) is 30% by mass or less, excessively high reactivity is further suppressed, workability is further improved, and filling property is ensured. It is further suppressed that the hardness of the resulting sealing material becomes too high.

The hydroxyl value of the polyol (G) is preferably 50 mgKOH/g or more and 1000 mgKOH/g or less, and more preferably 75 mgKOH/g or more and 750 mgKOH/g or less from the viewpoint of easy handling of the polyol (G). From the viewpoint of excellent molding processability and adhesive strength of the polyurethane resin, the hydroxyl value of the polyol (G) is most preferably 100 mgKOH/g or more and 500 mgKOH/g or less.

The viscosity of the polyol (G) at 25° C. is preferably 100 mPa·s or more and 6000 mPa·s or less, and more preferably 200 mPa·s or more and 4000 mPa·s or less from the viewpoint of easy handling of the polyol (G). From the viewpoint of excellent molding processability of the polyurethane resin, the viscosity of the polyol (G) at 25° C. is most preferably 400 mPa·s or more and 2000 mPa·s or less.

The polyurethane resin-forming composition of the present embodiment can be obtained by reacting an allophanate group-containing polyisocyanate prepolymer (F) with a polyol (G). The resulting polyurethane resin-forming composition can be used as sealing materials for various types of membranes, such as hollow fiber membrane module sealing materials, flat membrane module sealing materials, and spiral membrane sealing materials.

As the polyurethane resin-forming composition, the molar ratio of the isocyanate groups of the allophanate group-containing polyisocyanate composition (F) to the active hydrogen groups of the polyol (G) (isocyanate groups/active hydrogen groups) is 0.8 or more. It is preferably within the range of 6 or less. Further, the molar ratio is more preferably in the range of 0.9 or more and 1.2 or less, and more preferably in the range of 1.0 or more and 1.1 or less, from the viewpoint of excellent molding processability and adhesive strength of the polyurethane resin. Especially preferred. According to the composition obtained in such a mixing ratio, a composition having even better durability can be obtained.

The solvent extraction rate of the polyurethane resin-forming composition (measurement method will be described later) is preferably 2.0% by mass or less, particularly preferably 1.0% by mass or less.

In the present embodiment, if necessary, the isocyanate group of the allophanate group-containing polyisocyanate prepolymer (F) and the metal compound such as an organotin compound that promotes the reaction between the active hydrogen group of the polyol (G) Known urethane catalysts such as catalysts and tertiary amine catalysts such as triethylenediamine (TEDA), tetramethylhexamethylenediamine (TMHMDA), pentamethyldiethylenetriamine (PMDETA), dimethylcyclohexylamine (DMCHA), and bisdimethylaminoethyl ether (BDMAEA) conversion catalysts can be used.

Moreover, the polyurethane resin-forming composition according to the present embodiment may contain additives such as an antioxidant, an ultraviolet absorber, and an antifoaming agent, as long as they do not impair the purpose.

When obtaining a sealing material for a module using a hollow fiber separation membrane using the polyurethane resin-forming composition according to the present embodiment, the composition is reacted at room temperature (20° C. or higher and 30° C. or lower), or The allophanate group-containing polyisocyanate composition (F) and the polyol (G) may each be heated to 30° C. or higher and 60° C. or lower to react in order to shorten the gelling time and reduce the mixed viscosity. In order to shorten the gelation time, the molding temperature may be set to 0° C. or higher and 100° C. or lower, preferably 20° C. or higher and 80° C. or lower, more preferably 30° C. or higher and 60° C. or lower.

<Sealing materials, membrane modules>
A sealing material according to an embodiment of the present invention comprises a cured product of the polyurethane resin-forming composition described above. That is, the polyurethane resin-forming composition described above can be cured and used as a sealing material. At this time, the sealing material is preferably transparent to the extent that one side of the sealing material can be viewed from the other side. In particular, sealing materials for membrane modules constituting medical and industrial separation devices are required to be free from visual turbidity in order to confirm the presence of foreign matter.

Further, in the membrane module according to one embodiment of the present invention, a gap between the membrane and a part of the module (in particular, a gap between the end of the membrane and the inner wall of the housing) is filled with the polyurethane resin-forming composition described above. , the gap is sealed by curing to form a sealing material. That is, the membrane module according to one embodiment of the present invention is sealed with the sealing material described above.

A membrane module according to one embodiment of the present invention will be described in further detail with reference to the drawings.
FIG. 1 is a conceptual diagram showing an example of the configuration of a membrane module according to one embodiment of the present invention.
A membrane module (hollow fiber membrane module) 100 shown in FIG. 1 includes a housing 11 in which a plurality of hollow fiber membranes 13 are filled. For example, in the case of a hollow fiber membrane module used as a dialyzer, thousands to tens of thousands of hollow fiber membranes are packed.

Housing 11 has a cylindrical shape. Sealing members 19 are provided at both ends (left and right ends in FIG. 1) inside the housing 11, respectively. The sealing material fills and seals the gaps between the hollow fiber membranes 13 and between the hollow fiber membranes 13 and the inner wall of the housing 11 and binds the plurality of hollow fiber membranes 13 together.

A first fluid inlet 15 and a first fluid outlet 17 are provided on the side surface of the housing 11, through which the first fluid (gas or liquid) flows in and out from the outside. The first fluid that has flowed in from the first fluid inlet 15 passes through the gap (outside the hollow fiber membranes) while coming into contact with the plurality of hollow fiber membranes 13 filled in the housing 11, and reaches the first fluid outlet 17. discharged from Since the sealing material 19 does not exist inside the hollow fiber membranes 13, the hollow fiber membranes 13 have a second inlet (one end side) and a second outlet (at one end) provided in a cap member (not shown). The second fluid (gas or liquid) flows in and out from the outside via the other end). When the first fluid and the second fluid come into contact via the hollow fiber membrane 13, mass transfer from one fluid to the other fluid occurs. For example, in the case of a hollow fiber membrane dialyzer, contact between the dialysate and the blood transfers waste products and excess water in the blood to the dialysate.

The membrane module 100 shown in FIG. 1 includes a plurality of hollow fiber membranes 13, and the sealing material 19 seals the gaps at both ends of them. However, the membrane module according to the present embodiment is not limited to this. not to be For example, membranes of various shapes such as a plurality of or single flat membranes, spiral membranes and the like may be used. In addition, the sealing material is not limited to the structure provided at both ends of the membrane, and may be provided only at a part of the membrane (one end in the case of a hollow fiber), or at all the ends of the membrane, for example, a flat membrane. may be provided on the entire outer edge of the Furthermore, the sealing material may be provided on a portion of the film other than the end portion for sealing.

INDUSTRIAL APPLICABILITY A membrane module according to one embodiment of the present invention has excellent defoaming properties and excellent suppression of extractables, so that it can be suitably used as a medical or water treatment module. Specific examples of membrane modules include plasma separators, artificial lungs, artificial kidneys, artificial livers, and domestic and industrial water treatment devices.

Although the present invention will be described below, the present invention should not be construed as being limited to these examples. In addition, hereinafter, "%" means "% by mass" unless otherwise specified.

The following ingredients were used in the Examples and Comparative Examples.
(1) MDIs
Iso A1; 4,4'-MDI (Millionate MT, purity 99% manufactured by Tosoh Corporation)
Iso A2: 4,4'-MDI/(2,4'-MDI+2,2'-MDI) = 45/55 wt% MDI (Millionate NM manufactured by Tosoh Corporation)
(2) Polyol compound (expressed as polyol including monool)
Poly B1; Esterified product of castor oil fatty acid and methanol (COFA methyl ester-D hydroxyl value 163 KOHmg / g average functional group number 1 manufactured by Ito Oil Co., Ltd.)
Poly B2; Esterified product of castor oil fatty acid and 1-butanol (COFA butyl ester-D hydroxyl value 148 KOHmg / g average functional group number 1 manufactured by Ito Oil Co., Ltd.)
Poly B3: Esterified product of castor oil fatty acid and polypropylene glycol monobutyl ether (molecular weight 340) (compound obtained in Monool Synthesis Example 1 below, average functional group number 1)
Poly B4; 2-octyldodecanol (Carcol 200GD, hydroxyl value 185KOHmg/g average functionality 1, manufactured by Kao Corporation)
Poly B5; polypropylene glycol mono-2-ethylhexyl ether (Rheocon 1015H, hydroxyl value 72 KOHmg/g average functionality 1, manufactured by Lion Specialty Chemicals)
Poly E1; castor oil (LAV hydroxyl value 160 KOHmg/g molecular weight 947 average functional group number 2.7 manufactured by Ito Oil Co., Ltd.)
Poly E2; polyoxypropylene glycol (P-1000 hydroxyl value 110 KOHmg/g molecular weight 1000, average functional group number 2 manufactured by ADEKA)
Poly H1; castor oil (LAV hydroxyl value 160 KOHmg/g, manufactured by Ito Oil Co., Ltd.)
Poly H2; N,N,N',N'-tetrakis[2-hydroxypropyl]ethylenediamine (EDP-300 hydroxyl value 760 KOHmg/g manufactured by ADEKA)
(3) Catalyst Catalyst C; zinc acetylacetone (manufactured by Tokyo Chemical Industry Co., Ltd.)
(4) Catalyst poison Catalyst poison D: benzoyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.).

<Method for Defoaming Evaluation>
1) Weigh 100 g of the resulting prepolymer into a 200 ml polypropylene (PP) cup.
2) Stir at 500 rpm for 10 seconds with a clover blade attached to a rotating machine.
3) Transfer 20 ml of sample to a 100 ml PP cup.
4) Set 3) in a filter bell equipped with a vacuum pump, and start decompression.
5) Reduce the pressure to an absolute pressure of 70 mmHg in 20 seconds after starting the pressure reduction.
6) Read the foam height 60 seconds after the start of depressurization with the capacity of a 100 ml PP cup.

Those with good defoaming properties swell once, but after about 20 to 30 seconds from the start of defoaming, the foam breaks and returns to about the original volume (20 ml). Those with poor defoaming properties remain inflated without breaking. In the above test, a prepolymer having a volume of 20 ml or more and 50 ml or less after 60 seconds from the start of depressurization was judged to have good defoaming properties because it could be immediately subjected to molding.

<Solvent extraction rate evaluation procedure>
(Solvent extraction rate measurement sample molding method)
Each of the polyurethane resin-forming compositions according to the combinations shown in Table 2 was degassed under reduced pressure at 10 to 20 kPa for 3 minutes, and then 80 g was poured onto release paper (220 mm×170 mm×10 mm). This was cured by standing at 45° C. for 2 days to obtain a cured resin.

(Extraction test method)
The cured resin obtained was cut into 1 cm squares, 20 g of this was weighed, methanol was added in an amount 10 times the weight of the resin, and the mixture was shaken at 25° C. for 24 hours. After filtration and drying, the extraction rate was calculated from the resin mass before and after extraction.

<Resin deaeration>
The polyurethane resin-forming compositions according to the combinations shown in Table 2 were degassed under reduced pressure at 10 to 20 kPa for 3 minutes, and then poured into a stainless steel mold (100 mm×100 mm×8 mm). After standing and curing this at 45° C. for 2 days, it was removed from the mold to obtain a cured product. The appearance of the obtained cured product was visually evaluated, and A was given when there were no air bubbles, and B was given when even a few air bubbles were observed.

<Monool Synthesis Example 1>
In a 1 liter four-necked flask equipped with a stirrer, thermometer, heating device, and distillation column, 479 parts of ricinoleic acid (CO-FA, manufactured by Ito Oil Co., Ltd.), polypropylene glycol monobutyl ether with a number average molecular weight of 340 (Sanyo Chemical Industries, Ltd. 479 parts of (manufactured by Co., Ltd.) is added, heated to 190°C while increasing the temperature at a rate of 10°C/hour at 110°C for 2 hours under a nitrogen stream, and further reacted at 190°C for 2 hours to remove water. distilled off. Next, 0.05 part of tetrabutyl titanate (TBT-100 manufactured by Katayama Kagaku Kogyo Co., Ltd.) is added and the nitrogen supply is stopped. was distilled off.

<Example 1>
655.0 g of MDI 1 was added to a 1-liter four-necked flask, and the temperature was adjusted to 50° C. while stirring under a nitrogen stream. Then, 345.0 g of polyol B1 was added while stirring, and the temperature was raised to 90° C. after the heat generation of the urethanization reaction subsided. When the internal temperature stabilized at 90°C, 0.1 g of catalyst C was added, and after reacting at 90°C for 4 hours, 0.14 g of catalyst poison D was added to stop the reaction. The synthesized prepolymer was a pale yellow transparent liquid with a viscosity of 1900 mPa·s at 25°C. As a result of evaluating the defoaming property, prepolymer F1, which is the object of one embodiment of the present invention, was obtained after the initiation of defoaming. Table 1 shows the properties and defoaming evaluation results.

<Examples 2 to 6>
A prepolymer was synthesized in the same manner as in Example 1 except that the composition of MDI and polyol was changed as shown in Table 1. All prepolymers were pale yellow transparent liquid prepolymers with low viscosity and good defoaming properties. Table 1 shows the properties and defoaming evaluation results.

<Comparative Examples 1 and 2>
A prepolymer was synthesized in the same manner as in Example 1 except for changing the composition of the A component and the B component as shown in Table 1. The resulting prepolymer was a pale yellow transparent liquid, but had poor defoaming properties. Table 1 shows the properties and defoaming evaluation results.

<Production example of polyol (G1)>
180 parts by mass of poly H and 20 parts by mass of poly H2 were mixed to prepare polyol component G1. The viscosity at 25° C. was 1150 mPa·s and the hydroxyl value was 280 mgKOH/g.

<Examples 7 to 12>
The polyurethane resin-forming compositions obtained by the combinations shown in Table 2 were excellent in defoaming properties. Moreover, the obtained polyurethane resin had an excellent appearance. Furthermore, in Examples 11 and 12 using polyol (E), polyurethane resins with less extractables were obtained.

<Comparative Examples 3-4>
All of the polyurethane resin-forming compositions according to the combinations shown in Table 2 were polyurethane resins with poor defoaming properties. Moreover, the obtained polyurethane resin was not excellent in appearance.

Claims (7)

A polyurethane resin-forming composition for a hollow fiber membrane sealing material, comprising an allophanate group-containing polyisocyanate prepolymer (F) and a polyol (G),
reaction of the allophanate group-containing polyisocyanate prepolymer (F) with diphenylmethane diisocyanate (A), an esterified product (B ), and an optionally used polyol (E) in the presence of an allophanate-forming catalyst (C); and a reaction product resulting from termination of the reaction using the catalyst poison (D) ,
The ester compound (B) is
ricinoleic acid (B-1); and
an ester of alcohol (B-2),
The alcohol (B-2) is methanol, ethanol, 1-propanol , 2-propanol, 1- butanol, 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 -heptatriacontanol , 1-oleyl alcohol, 2-octyldodecanol and mixtures thereof Any one selected; selected from the group consisting of polyalkylene glycol monoalkyl ethers, polyalkylene glycol monoaryl ethers, and one or more polyalkylene glycol monoalkyl ethers and one or more polyalkylene glycol monoaryl ethers any one selected from a mixture of two or more ; or any one selected from a mixture of a polyalkylene glycol monocarboxylic acid ester and two or more polyalkylene glycol monocarboxylic acid esters ;
The NCO content of the allophanate group-containing polyisocyanate prepolymer (F) is 12.0% by mass or more,
The allophanate group-containing polyisocyanate prepolymer (F) has a viscosity at 25° C. of 2,000 mPa s or less,
A polyurethane resin-forming composition for a hollow fiber membrane sealing material, further comprising a residue formed from an allophanate-forming catalyst (C) and a catalyst poison (D). 2. The polyurethane resin-forming composition for a hollow fiber membrane sealing material according to claim 1 , wherein the alcohol (B-2) is a polypropylene glycol monoalkyl ether having a molecular weight of 200 or more and 2000 or less. 3. The hollow fiber membrane according to claim 1 , wherein the reaction product is a reaction product of the diphenylmethane diisocyanate (A), the ester compound (B), and the polyol (E). A polyurethane resin-forming composition for sealing materials. 4. The polyurethane resin-forming composition for a hollow fiber membrane sealing material according to claim 3, wherein the polyol (E) has an average functional group number of 2 or more. 5. The polyurethane resin-forming composition for a hollow fiber membrane sealing material according to claim 3 or 4, wherein the polyol (E) has a molecular weight of 500 or more and 3000 or less. A hollow fiber membrane sealing material comprising a cured product of the polyurethane resin-forming composition according to any one of claims 1 to 5 . A hollow fiber membrane module sealed with the sealing material according to claim 6 .

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