JP7326700B2 - POLYURETHANE RESIN FORMABLE COMPOSITION AND SEALING MATERIAL AND MEMBRANE MODULE USING THE FORMABLE COMPOSITION - Google Patents

Description

TECHNICAL FIELD The present invention relates to a polyurethane resin forming composition, and a sealing material and a membrane module using the forming composition.

Polyurethane resin is widely used as a sealing material for adhering and fixing the ends of the membrane to the membrane module main body. As such polyurethane resins, for example, many polyurethane resins using diphenylmethane diisocyanate (hereinafter also referred to as MDI) as an isocyanate component have been proposed.

However, when a polyurethane resin-forming composition containing MDI is used, a low-molecular-weight reaction product is generated from MDI and polyol, and the low-molecular-weight reaction product is eluted into the liquid, although in a very small amount. There is concern about performance degradation. In particular, in the case of a membrane module in which hollow fibers are used as separation membranes, since the hollow fibers used contain a retention agent (glycerin) for maintaining pores, low-molecular-weight reactants of MDI and polyol In addition to this, a low-molecular-weight reaction product of MDI and glycerin is produced and eluted.

Accordingly, Patent Document 1 discloses a polyurethane resin-forming composition for casting into which toluenediisocyanate (hereinafter also referred to as TDI) is introduced for the purpose of reducing the elution of the low-molecular-weight reactant.
However, the glycerin-containing hollow fibers used in recent artificial kidneys and the like have large pore diameters and require a large amount of glycerin for storage. Therefore, when a polyurethane resin-forming composition containing MDI is used, more of the low-molecular-weight reactants are produced, and improvement is desired. Further, even in membrane modules using non-glycerin-containing hollow fibers, further suppression of elution of low-molecular-weight reactants is desired.

If, for example, the amount of the MDI monomer in the isocyanate component is reduced in order to reduce the low-molecular-weight reactants, the viscosity of the polyurethane resin-forming composition increases, and molding defects are a concern.
As a method for reducing the viscosity of an isocyanate component using MDI, Patent Document 2 discloses a technique using an allophanate group-containing polyisocyanate prepolymer derived from MDI and polyether monool. However, even with such a technique, a large amount of low-molecular-weight reaction products of MDI and other components (polyol, glycerin, etc.) is still eluted, and the defoaming property during molding is poor, leaving air bubbles. It was a problem to put away.

JP-A-6-25383 JP 2009-030059 A

The present invention has been made in view of the above circumstances, and an object of the present invention is to produce a urethane resin that suppresses the generation of leached substances caused by low-molecular-weight reactants, has excellent moldability, and has an excellent appearance. An object of the present invention is to provide a polyurethane resin-forming composition that contributes to forming, and a sealing material and a membrane module using the forming composition.

As a result of intensive studies by the present inventors, allophanate group-containing polyisocyanate prepolymer (A) which is a reaction product of diphenylmethane diisocyanate (a1) and alkyl alcohol (a2) having a specific structure, polyol (B), The present inventors have found that the above problems can be solved by setting the mass of the monomer of diphenylmethane diisocyanate (a1) relative to the total amount to a specific range, and have completed the present invention.

That is, the present invention includes the following embodiments (1) to (6).
(1): A polyurethane resin-forming composition comprising an allophanate group-containing polyisocyanate prepolymer (A) and a polyol (B),
The allophanate group-containing polyisocyanate prepolymer (A) is a reaction product of diphenylmethane diisocyanate (a1) and an alkyl alcohol having 10 or more carbon atoms (a2),
A polyurethane resin-forming composition, wherein the monomer amount of the diphenylmethane diisocyanate (a1) is 15.0% by mass or more and 20.0% by mass or less relative to the total mass of the polyurethane resin-forming composition.
(2): The reaction product is a reaction product of the diphenylmethane diisocyanate (a1), the alkyl alcohol having 10 or more carbon atoms (a2), and the polyol (a3). The polyurethane resin-forming composition according to (1) above.
(3): The polyurethane resin-forming composition as described in (2) above, wherein the polyol (a3) has an average number of functional groups of 2 or more.
(4): The polyurethane resin-forming composition as described in (2) or (3) above, wherein the polyol (a3) has a molecular weight of 500 or more and 1,000 or less.
(5): A sealing material comprising a cured product of the polyurethane resin-forming composition according to any one of (1) to (4) above.
(6): A membrane module sealed with the sealing material according to (5) above.

According to one embodiment of the present invention, there is provided a urethane resin-forming composition that suppresses the generation of leached substances caused by low-molecular-weight reactants, has excellent moldability, and contributes to the formation of a urethane resin having an excellent appearance. can do. Further, according to another embodiment of the present invention, it is possible to provide a sealing material and a membrane module using the moldable composition.

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

[Urethane resin-forming composition]
A urethane resin-forming composition according to one embodiment of the present invention is
an allophanate group-containing polyisocyanate prepolymer (A);
and a polyol (B),
The allophanate group-containing polyisocyanate prepolymer (A) is
diphenylmethane diisocyanate (a1);
A reaction product of an alkyl alcohol (a2) having 10 or more carbon atoms,
The monomer amount of diphenylmethane diisocyanate (a1) is 15.0% by mass or more and 20.0% by mass or less relative to the total mass of the forming composition.

The inventors of the present invention conducted further studies on the urethane resin-forming composition, and found that when the urethane resin-forming composition was cured to obtain a cured product, the cured product was sometimes extracted by a solvent. I found out something. If the cured product is extracted by the solvent, the performance may be lowered and the life of the cured product may be shortened.
As a result of extensive studies by the present inventors, the allophanate group-containing polyisocyanate prepolymer (A) is further added with a polyol (a3) to make it a reaction product of a system, resulting in a polyurethane containing the reaction product It was found that the cured product obtained by curing the resin-forming composition has a further reduced amount of extractables extracted by the solvent.

Therefore, a urethane resin-forming composition according to another embodiment of the present invention is
an allophanate group-containing polyisocyanate prepolymer (A);
and a polyol (B),
The allophanate group-containing polyisocyanate prepolymer (A) is
diphenylmethane diisocyanate (a1);
an alkyl alcohol (a2) having 10 or more carbon atoms;
A reaction product of the polyol (a3),
The monomer amount of diphenylmethane diisocyanate (a1) is 15.0% by mass or more and 20.0% by mass or less relative to the total mass of the forming composition.

<Allophanate group-containing polyisocyanate prepolymer (A)>
<<Diphenylmethane diisocyanate (a1)>>
As the diphenylmethane diisocyanate (a1), any commonly available diphenylmethane diisocyanate (hereinafter also referred to as MDI) monomer can be used. The isomers of the MDI monomer usually contain 2,2′-MDI in an amount of 0% by mass to 5% by weight, 2,4′-MDI in an amount of 0% by weight to 95% by weight, and 4,4′-MDI in an amount of 5% by weight to 100% by weight. It is a single substance or an isomer mixture of the MDI monomer containing not more than mass %.
As the MDI (a1), the aforementioned MDI is preferably used in order to obtain an allophanate group-containing polyisocyanate prepolymer (A) with a lower viscosity. However, polymethylene polyphenylene polyisocyanate (polymeric MDI) can also be used as the MDI (a1) if the allophanate group-containing polyisocyanate prepolymer (A) is allowed to have a certain degree of viscosity increase. In that case, the content of the polymethylene polyphenylene polyisocyanate is preferably 0% by mass or more and 50% by mass or less in the isocyanate component used. When it is 50% by mass or less, the viscosity becomes sufficiently low, and the formation of insoluble matter can be suppressed to a higher degree.

<<alkyl alcohol (a2)>>
Any alkyl alcohol (a2) having 10 or more carbon atoms can be used. The alkyl alcohol (a2) preferably has 10 or more carbon atoms, more preferably 10 or more and 105 or less carbon atoms.
Examples of alkyl alcohols having 10 or more carbon atoms include 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-hepta Aliphatic compounds such as decanol, 1-octadecanol, 1-nonadecanol, 1-eicosanol, 1-hexacosanol, 1-heptatricontanol, 1-oleyl alcohol, 2-octyldodecanol, 2-dodecyltetradecanol monoalcohols, mixtures thereof, and the like.
The molecular weight of the alkyl alcohol is preferably 158 or more and 1500 or less. The molecular weight of the alkyl alcohol is more preferably 200 or more and 1000 or less from the viewpoint of excellent molding processability and adhesive strength of the polyurethane resin. From the viewpoint of reducing the elution of the polyurethane resin, the molecular weight of the alkyl alcohol is more preferably 214 or more and 800 or less.

<<Polyol (a3)>>
Polyol (a3) is an optional component as described above. Therefore, by reacting the MDI (a1), the alkyl alcohol (a2), and optionally the polyol (a3), an allophanate group-containing polyisocyanate prepolymer (A), which is a reaction product, can be obtained.
From the viewpoint of reducing the amount of extracts extracted by the solvent, the monomer amount of the polyol (a3) with respect to the total mass of the urethane resin-forming composition is preferably 1.0% by mass or more and 25.0% by mass or less. It is preferably 2.0% by mass or more and 15.0% by mass or less.

Any polyol (a3) having an average number of functional groups of 2 or more can be used.
The average number of functional groups is more preferably 2 or more and 3 or less from the viewpoint of moldability of the polyurethane resin and reduction of extractables.
Examples of the polyol (a3) 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 (a3) is preferably 500 or more and 3000 or less. The molecular weight of the polyol (a3) is more preferably 600 or more and 2500 or less from the viewpoint of excellent molding processability and adhesive strength of the polyurethane resin.

The content of the monomer of MDI (a1) in the allophanate group-containing polyisocyanate prepolymer (A) is preferably 15.0% by mass or more and 40.0% by mass or less, and processing such as cutting of the cured polyurethane resin is easy. From a viewpoint, 17.0 mass % or more and 38.0 mass % or less are more preferable. From the viewpoint of reducing the elution of the polyurethane resin, the monomer content of MDI (a1) is most preferably 19.0% by mass or more and 36.0% by mass or less.

The content of the monomer of MDI (a1) present in the allophanate group-containing polyisocyanate prepolymer (A) was determined from the peak area % obtained by gel permeation chromatography (GPC) measurement. . A method for measuring the monomer content of MDI (a1) will be described later.

The allophanate group-containing polyisocyanate prepolymer (A) is obtained by subjecting MDI (a1), an alkyl alcohol having 10 or more carbon atoms (a2), and an optionally added polyol (a3) to a urethanization reaction, It can be obtained by adding a predetermined amount of the catalyst (C) to form an allophanate and stopping the reaction with the catalyst poison (D).

<<catalyst (C)>>
Examples of the catalyst (C) include zinc acetylacetonate; metal carboxylates such as zinc, lead, tin, copper and cobalt, and mixtures thereof; tertiary amines, tertiary amino alcohols, quaternary ammonium salts and mixtures thereof. , etc.
The amount of catalyst (C) added is preferably in the range of 1 ppm to 1000 ppm, more preferably in the range of 10 ppm to 500 ppm. When the amount of the catalyst (C) added is 1 ppm or more, the reaction becomes more rapid, and when it is 1000 ppm or less, coloration of the prepolymer can be suppressed to a higher degree.

<<catalyst poison (D)>>
Suitable catalyst poisons (D) are acidic substances, including, for example, anhydrous hydrogen chloride, sulfuric acid, phosphoric acid, monoalkylsulfuric acid esters, alkylsulphonic acids, alkylbenzenesulphonic acids, mono- or dialkylphosphoric acid esters, benzoyl chloride and Lewis acids. be The amount to be added is preferably equivalent to or more than the number of moles of the catalyst (C), preferably 1.0 to 1.5 times the molar equivalent.

The isocyanate group content of the allophanate group-containing polyisocyanate prepolymer (A) is preferably 3.0% by mass or more and 30.0% by mass or less, and it is said that the allophanate group-containing polyisocyanate prepolymer (A) is easy to handle. From a viewpoint, 5.0 mass % or more and 28.0 mass % are more preferable. From the viewpoint of excellent molding processability and adhesive strength of the polyurethane resin, the isocyanate group content of the allophanate group-containing polyisocyanate prepolymer (A) is most preferably 10.0% by mass or more and 26.0% by mass or less. .

The viscosity of the allophanate group-containing polyisocyanate prepolymer (A) at 25 ° C. is preferably 50 mPa s or more and 8000 mPa s or less, and from the viewpoint that the allophanate group-containing polyisocyanate prepolymer (A) is easy to handle, it is 100 mPa. ·s or more and 7000 mPa·s or less is more preferable. From the viewpoint of excellent molding processability of the polyurethane resin, the viscosity at 25° C. of the allophanate group-containing polyisocyanate prepolymer (A) is most preferably 200 mPa·s or more and 6000 mPa·s or less.

The urethanization reaction is preferably carried out at a temperature in the range of 45° C. or higher and 80° C. or lower until the target NCO content is achieved. If the temperature is 45°C or higher, the precipitation of monomer MDI crystals can be suppressed to a greater extent, and if the temperature is 80°C or lower, the formation of side reaction products can be suppressed to a higher extent.

The allophanatization reaction is preferably carried out in a temperature range of 90° C. or higher and 130° C. or lower until the target NCO content is achieved. When the temperature is 90°C or higher, the reaction progresses more rapidly, and when the temperature is 130°C or lower, the formation of by-products can be suppressed to a higher degree.

During the allophanatization reaction, when the catalyst poison (D) is added before the target NCO content is reached, MDI (a1), alkyl alcohol having 10 or more carbon atoms (a2), or further polyol (a3) Since the urethane compound that reacted with , remains, the amount of elution may increase. Further, if the reaction progresses too much and the NCO content becomes lower than the target, the viscosity may become high and the moldability may deteriorate.

<Polyol (B)>
The polyol (B) is not particularly limited as long as it can react with the allophanate group-containing polyisocyanate prepolymer (A) 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 (B) 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.

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.

Moreover, when using a hydroxyl group-containing amine-based compound, the blending amount thereof in the polyol (B) is preferably in the range of 1% to 30% by mass, and particularly preferably in the range of 5% to 25% by mass. When the proportion of the hydroxyl group-containing amine compound in the polyol (B) 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 (B) 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 (B) 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 (B). From the viewpoint of excellent moldability and adhesive strength of the polyurethane resin, the hydroxyl value of the polyol (B) is most preferably 100 mgKOH/g or more and 500 mgKOH/g or less.

The viscosity of the polyol (B) 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 that the polyol (B) is easy to handle. From the viewpoint of excellent molding processability of the polyurethane resin, the viscosity of the polyol (B) 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 (A) with a polyol (B). 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. Among them, a polyurethane resin-forming composition in which the monomer amount of MDI (a1) is 15.0% by mass or more and 20.0% by mass or less with respect to the total mass of the polyurethane resin-forming composition is excellent in moldability. Less leachables due to low-molecular-weight reaction products between MDI and other components (particularly glycerin). Therefore, a polyurethane resin-forming composition in which the monomer amount of MDI (a1) is within this range is useful as a sealing material for membrane modules, particularly as a sealing material for medical membrane modules using hollow fibers containing glycerin.

As the polyurethane resin-forming composition, the molar ratio of the isocyanate groups in the allophanate group-containing polyisocyanate composition (A) to the active hydrogen groups in the polyol (B) (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 monomer amount (mass) of the MDI (a1) constituting the allophanate group-containing polyisocyanate prepolymer (A) with respect to the total mass of the polyurethane resin-forming composition can be obtained from these compounding ratios. The monomer amount of MDI (a1) is preferably 15.0% by mass or more and 20.0% by mass or less, and from the viewpoint of less low-molecular-weight extractables, it is 15.0% by mass or more and 19.0% by mass or less. more preferably 15.0% by mass or more and 18.0% by mass or less is particularly preferable. According to the composition obtained within this range, a composition with less low-molecular-weight elution and excellent moldability can be obtained.

The low-molecular-weight effluent value of the polyurethane resin-forming composition (measurement method will be described later) is preferably 0.070 or less, particularly preferably 0.050 or less.
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 (A) and the metal compound such as an organotin compound that promotes the reaction between the active hydrogen group of the polyol (B) 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 (A) and the polyol (B) 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.

The initial mixed viscosity of the polyurethane resin-forming composition is preferably 300 mPa·s or more and 2400 mPa·s or less, and more preferably 400 mPa·s or more and 2100 mPa·s or less from the viewpoint of easy handling up to molding. The initial mixed viscosity of the polyurethane resin-forming composition is most preferably 500 mPa·s or more and 1800 mPa·s or less from the viewpoint of excellent molding processability and filling properties of the polyurethane resin. The initial mixing viscosity of the polyurethane resin-forming composition is the viscosity one minute after mixing the allophanate group-containing polyisocyanate composition (A) and the polyol (B) for 30 seconds.

The pot life (reaction time) of the polyurethane resin-forming composition is preferably 60 seconds or more and 600 seconds or less, and more preferably 90 seconds or more and 480 seconds or less from the viewpoint of adhesive strength. From the viewpoint of excellent moldability of the polyurethane resin, the pot life of the polyurethane resin-forming composition is most preferably 120 seconds or more and 420 seconds. The pot life of the polyurethane resin-forming composition is defined as the time until the allophanate group-containing polyisocyanate composition (A) and the polyol (B) are mixed for 30 seconds and reach 50,000 mPa s from the start of mixing. is the time required for

The hardness of the polyurethane resin-forming composition at 25° C. is preferably 30 or more and 80 or less in Shore D, and more preferably 35 or more and 75 or less from the viewpoint of facilitating processing such as cutting of the cured polyurethane resin. The hardness (ShoreD) at 25° C. of the polyurethane resin-forming composition is most preferably 40 or more and 70 or less from the viewpoint of excellent moldability and adhesive strength of the polyurethane resin.

[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, the gap between the membrane and a part of the module (especially the 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, and the first fluid (gas or liquid) flows into and out of the housing 11 through these. 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 provided in a cap member (not shown). A second fluid (gas or liquid) flows in and out through (the other end side). Then, when the first fluid and the second fluid come into contact with each other through the hollow fiber membrane 13, a ) mass transfer 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 has a plurality of hollow fiber membranes 13, and the sealing material 19 seals the gaps at both ends of the membranes. It is not limited. For example, it may be a plurality of or singular membranes having various shapes such as flat membranes, spiral membranes, and the like. 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), and may be provided 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. Moreover, although the housing 11 of the membrane module 100 shown in FIG. 1 has a cylindrical shape, it may have any shape other than a cylindrical shape.

INDUSTRIAL APPLICABILITY A membrane module according to an embodiment of the present invention can be suitably used as a medical or water treatment module because the generation of extracts is well suppressed. Specific examples of membrane modules include plasma separators, artificial lungs, artificial kidneys, artificial livers, and domestic and industrial water treatment devices.

Hereinafter, the polyurethane resin-forming composition according to one embodiment of the present invention will be described in more detail with reference to examples, but the present invention should not be construed as being limited to these examples. In addition, hereinafter, "%" means "% by mass" unless otherwise specified. Further, among Examples 1 to 6 shown below, Examples 1 to 4 are examples as reference examples that do not belong to the scope of the present invention.

The following ingredients were used in the Examples and Comparative Examples.
[Diphenylmethane diisocyanate (a1)]
a1-1; 4,4'-MDI (Millionate MT manufactured by Tosoh Corporation, isocyanate group content = 33.6%)
a1-2; a mixture of 2,4'-MDI and 4,4'-MDI (Millionate NM manufactured by Tosoh Corporation, isocyanate group content = 33.6%)
a1-3: Carbodiimide modified 4,4'-MDI (Millionate MTL-C manufactured by Tosoh Corporation, isocyanate group content = 28.6%)

[Alkyl alcohol (a2)]
a2-1; 2-octyldodecanol (manufactured by Kao Co., Ltd. Calcoal 200GD, molecular weight = 300, hydroxyl value = 185 mgKOH / g average functional group number 1)
a2-2; Isotridecanol (tridecanol manufactured by KH Neochem, molecular weight = 200, hydroxyl value = 275 mgKOH/g, average functional group number 1)
a2-3; 2-ethylhexanol (KH Neochem octanol, molecular weight = 130, hydroxyl value = 430 mgKOH/g average functional group number 1)
a2-4; Polyoxypropylene glycol mono-2-ethylhexyl ether (Leocon 1015H manufactured by Lion Specialty Chemicals, molecular weight = 800, hydroxyl value = 70 mgKOH/g, average functional group number 1)

[Polyol (a3)]
a3-1; castor oil (manufactured by Ito Oil Co., Ltd. castor oil LAV, hydroxyl value = 160 mgKOH / g average functional group number 2.7 molecular weight 947)
a3-2; Polyoxypropylene glycol (P-1000 manufactured by ADEKA, hydroxyl value = 110 mgKOH/g average functional group number 2 molecular weight 1000)

[Polyol (B)]
b-1; castor oil (manufactured by Ito Oil Co., Ltd. castor oil LAV, hydroxyl value = 160 mgKOH / g)
b-2; N,N,N',N'-tetrakis[2-hydroxypropyl]ethylenediamine (ADEKA EDP-300, hydroxyl value = 760 mgKOH/g)

[catalyst]
Catalyst c: zinc acetylacetone (manufactured by Tokyo Chemical Industry Co., Ltd.)
[catalyst poison]
Catalyst poison d; benzoyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.)

In the production examples, examples, and comparative examples, the predetermined amount refers to each composition amount shown in Tables 1 to 4.

[Prepolymer (A) Production Example 1]
A predetermined amount of a1-1 was added to a 1-liter four-necked flask, and the temperature was adjusted to 50° C. while stirring under a nitrogen stream. Next, a predetermined amount of a2-1 was added while stirring, and after the heat generation of the urethanization reaction subsided, the temperature was raised to 90°C. When the internal temperature stabilized at 90° C., a predetermined amount of catalyst c was added and reacted at 90° C. for 4 hours, and a predetermined amount of catalyst poison d was added to terminate the reaction to obtain prepolymer A-1. Prepolymer A-1 was a pale yellow transparent liquid with a viscosity of 2800 mPa·s at 25°C. Table 1 shows its properties (NCO content, MDI monomer amount, viscosity, low-temperature storage stability). A method for measuring properties will be described later.

[Prepolymer (A) Production Examples 2 to 9, 13, 14]
Prepolymers A-2 to A-9, A-13 and A-14 were synthesized in the same manner as in Production Example 1 except that a1 to a3 were changed to the compositions shown in Tables 1 and 2. The properties are shown in Tables 1 and 2.

[Prepolymer (A) Production Example 10]
Predetermined amounts of a1-1 and a1-3 were added to a 1-liter four-necked flask, and the temperature was adjusted to 50° C. while stirring under a nitrogen stream. Next, a predetermined amount of b-1 was added while stirring, and after the heat generation of the urethanization reaction subsided, reaction was carried out at 75° C. for 3 hours to obtain prepolymer A-10. Prepolymer A-10 was a pale yellow transparent liquid with a viscosity of 12020 mPa·s at 25°C. Table 2 shows its properties.

[Prepolymer (A) Production Examples 11 and 12]
Prepolymers A-11 to A-12 were synthesized in the same manner as in Production Example 10 except that a1 and b-1 were changed to the compositions shown in Table 2. Table 2 shows its properties.

[Production example of polyol (B)]
Polyol component B-1 was prepared by mixing 80 parts by mass of polyol (b-1) and 20 parts by mass of polyol (b-2). The viscosity at 25° C. was 1150 mPa·s and the hydroxyl value was 280 mgKOH/g.
Polyol component B-2 was prepared by mixing 70 parts by mass of polyol (b-1) and 30 parts by mass of polyol (b-2). The viscosity at 25° C. was 1600 mPa·s and the hydroxyl value was 340 mgKOH/g.

[Examples 1 to 6, Comparative Examples 1 to 9]
Urethane resin compositions having the compositions shown in Tables 3 and 4 were molded.
The values shown in Tables 3 and 4 were calculated from the test results below.

[Measurement of NCO content]
In prepolymers A-1 to A-14 shown in Tables 1 and 2, the NCO content was determined according to JIS K1603-1:2007.

[MDI Monomer Content Measurement]
In the prepolymers A-1 to A-14 shown in Tables 1 and 2, the MDI monomer content (% by mass) was obtained by GPC measurement under the following conditions and method.

<Measurement conditions>
Measuring device: “HLC-8120 (trade name)” (manufactured by Tosoh Corporation)
(2) Column: Columns filled with TSKgel G3000HXL, TSKgel G2000HXL, and TSKgel G1000HXL (all trade names, manufactured by Tosoh Corporation) as packing materials are connected in series and measured and detected at a column temperature of 40°C. Instrument: RI (refractive index) meter Eluent: tetrahydrofuran (THF) (flow rate: 1 mL/min., 40°C)
Calibration curve: A calibration curve was obtained using the following grades of polystyrene (TSK standard POLYSTYRENE). F-2 (1.81×10 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)
Sample: THF 10 mL solution of 0.05 g sample

<Measurement method>
First, a calibration curve was obtained from a chart obtained by detecting a refractive index difference using polystyrene as a standard substance. Next, for each sample, the mass % of the peak near the peak top molecular weight (number average molecular weight) of 250 indicating the monomer of MDI was determined from the chart obtained by detecting the refractive index difference based on the same calibration curve.

[Low temperature storage stability]
Prepolymers A-1 to A-14 shown in Tables 1 and 2 were allowed to stand in an environment of 0° C. for 3 months, and the appearance of the samples was checked. A pale yellow transparent sample was rated as "A", and a sample with turbidity or generation of solid matter was rated as "B".

[Low-molecular-weight extractables value evaluation procedure]
<Low-molecular-weight extractables value measurement sample molding method>
Each of the polyurethane resin-forming compositions according to the combinations shown in Tables 3 and 4 was weighed so that the total mass was 80 g. After stirring for a second, a polyurethane resin-forming composition was obtained. 100 g of this polyurethane resin-forming composition was cast into a cartridge case (made of polycarbonate with an inner diameter of 48 mm) in a centrifugal molding machine and centrifugally molded to obtain a resin cured product (low-molecular-weight extractables value measurement sample). The centrifugal molding conditions were as follows: primary curing: 1500 rpm centrifugal molding machine speed, 50°C temperature, 15 minutes time; secondary curing: 45°C constant temperature bath for 48 hours.

<Elution test method>
The obtained resin cured product was cut into a fan shape, 20 g of this was weighed, 100 mL of purified water was added, and the product was shaken at 40° C. for 2 hours. Next, the resulting extract was decanted, diluted 5-fold to obtain a test solution, and the UV absorbance of the test solution was measured with an ultraviolet-visible spectrophotometer (UV-2500 manufactured by Shimadzu Corporation). The maximum value of absorbance at 240-245 nm/10 was taken as the low-molecular-weight effluent value.

[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 Tables 3 and 4 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.

[MDI Monomer Amount in Polyurethane Resin-Forming Composition]
From the MDI monomer amount of the prepolymer shown in Tables 1 and 2, the MDI monomer amount before the reaction was calculated from the NCO/OH molar ratio for the polyurethane resin-forming compositions obtained by the combinations shown in Tables 3 and 4. .

[Appearance evaluation]
The polyurethane resin-forming compositions according to the combinations shown in Tables 3 and 4 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 was no turbidity, and B was given when even a slight turbidity was observed.

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

[Evaluation of initial mixed viscosity] (Evaluation of moldability)
For each of the polyurethane resin-forming compositions according to the combinations shown in Tables 3 and 4, the main agent and curing agent at a liquid temperature of 45° C. were uniformly mixed for 30 seconds and allowed to stand. One minute after the start of mixing, the viscosity was measured with a rotational viscometer (RB-215L model manufactured by Toki Sangyo Co., Ltd.).

[Pot life evaluation]
For each of the polyurethane resin-forming compositions according to the combinations shown in Tables 3 and 4, the main agent and the curing agent at a liquid temperature of 45°C were uniformly mixed for 30 seconds (total of the main agent and the curing agent = 30 g), and then heated to 25°C. The increase in viscosity was measured under atmosphere using a rotational viscometer (RB-215L model manufactured by Toki Sangyo Co., Ltd.). The pot life was defined as the time from the start of mixing until the viscosity of the polyurethane resin-forming composition reached 50000 mPa·s, and the reactivity was evaluated.

As shown in Tables 3 and 4 above, the polyurethane resin compositions according to Examples 1 to 6 all have low low-molecular-weight extractables. Furthermore, the polyurethane resin compositions according to Examples 5 and 6 also have low solvent extraction rates. Moreover, it was found that Examples 1 to 6 had sufficiently low initial mixed viscosities, and had excellent moldability so that the membrane modules could be satisfactorily filled. All of the polyurethane resin-forming compositions according to Comparative Examples 1 to 4 and Comparative Examples 6 to 9 had high low-molecular-weight extractables. Although the polyurethane resin-forming composition according to Comparative Example 5 has a low low-molecular-weight extractables value, it has a high solvent extraction rate and a high initial mixed viscosity, which causes poor filling.

According to one embodiment of the present invention, it is possible to provide a polyurethane resin-forming composition in which generation of extractables is suppressed. A sealing material using a polyurethane resin-forming composition according to an embodiment of the present invention has many excellent performances, especially an excellent low extraction rate. Therefore, the sealing material according to one embodiment of the present invention can be suitably used as a sealing material for membrane modules constituting medical and industrial separation devices. Specific examples of medical and industrial separation devices include plasma separators, artificial lungs, artificial kidneys, artificial livers, and domestic and industrial water treatment devices.

Reference Signs List 11 housing 13 hollow fiber membrane 15 first fluid inlet 17 first fluid outlet 19 sealing material 100 membrane module (hollow fiber membrane module)

Claims (6)

an allophanate group-containing polyisocyanate prepolymer (A);
A polyurethane resin-forming composition comprising a polyol (B),
The allophanate group-containing polyisocyanate prepolymer (A) is
diphenylmethane diisocyanate (a1);
an aliphatic monoalcohol (a2) having 10 or more carbon atoms ;
A reaction product of the polyol (a3),
The aliphatic monoalcohol (a2) is 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-heptadecanol, from 1-octadecanol, 1-nonadecanol, 1-eicosanol, 1-hexacosanol, 1- heptatriacontanol , 1-oleyl alcohol, 2-octyldodecanol, 2-dodecyltetradecanol , isotridecanol One or more selected from the group consisting of
The molecular weight of the polyol (a3) is 600 or more and 2500 or less,
A polyurethane resin-forming composition, wherein the monomer amount of the diphenylmethane diisocyanate (a1) is 15.0% by mass or more and 20.0% by mass or less relative to the total mass of the polyurethane resin-forming composition.
However, the monomer amount of the diphenylmethane diisocyanate (a1) means the amount remaining in the monomer state in the reaction product. an allophanate group-containing polyisocyanate prepolymer (A);
A polyurethane resin-forming composition comprising a polyol (B),
The allophanate group-containing polyisocyanate prepolymer (A) is
diphenylmethane diisocyanate (a1);
an aliphatic monoalcohol (a2) having 10 or more carbon atoms;
A reaction product of the polyol (a3),
The aliphatic monoalcohol (a2) is 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-heptadecanol, from 1-octadecanol, 1-nonadecanol, 1-eicosanol, 1-hexacosanol, 1-heptatriacontanol, 1-oleyl alcohol, 2-octyldodecanol, 2-dodecyltetradecanol, isotridecanol One or more selected from the group consisting of
Polyol (a3) is one or more selected from the group consisting of polyether-based polyols and castor oil-based polyols,
A polyurethane resin-forming composition, wherein the monomer amount of the diphenylmethane diisocyanate (a1) is 15.0% by mass or more and 20.0% by mass or less relative to the total mass of the polyurethane resin-forming composition.
However, the monomer amount of the diphenylmethane diisocyanate (a1) means the amount remaining in the monomer state in the reaction product. 3. The polyurethane resin-forming composition according to claim 2, wherein the polyol (a3) has a molecular weight of 500 or more and 3,000 or less. 4. The polyurethane resin-forming composition according to any one of claims 1 to 3, which is used as a membrane sealing material. A sealing material comprising a cured product of the polyurethane resin-forming composition according to any one of claims 1 to 4. A membrane module sealed with the sealing material according to claim 5 .

Images