JP2019056097A - Polyurethane resin-formable composition, and seal material and membrane module using the formable composition - Google Patents

Abstract

To provide an urethane resin-formable composition that contributes to formation of an urethane resin which is suppressed from generation of eluates derived from a low molecular reaction product of diphenylmethane diisocyanate and glycerin, is excellent in moldability, and has excellent appearance.SOLUTION: A polyurethane resin-formable composition comprises an allophanate group-containing polyisocyanate prepolymer (A) that is a reaction product of diphenyl methane diisocyanate (a1) and an alkyl alcohol (a2) having 10 or more carbon atoms, and a polyol (B), where an amount of monomer, diphenyl methane diisocyanate (a1), relative to a total mass of the formable composition is 15-20 mass%.SELECTED DRAWING: None

Description

  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 bonding and fixing the end of the membrane to the membrane module body. As such a polyurethane resin, 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 reaction product of MDI and polyol is generated, and the low-molecular reaction product elutes in a small amount in the liquid. There is concern about performance degradation. Especially in the case of a membrane module in which a hollow fiber is used as a separation membrane, a retention agent (glycerin) for maintaining pores is used in the hollow fiber used, so that a low molecular reaction product of MDI and polyol. In addition, a low-molecular-weight reaction product of MDI and glycerin is generated and eluted.

Therefore, Patent Document 1 discloses a polyurethane resin-forming composition for casting into which toluene diisocyanate (hereinafter also referred to as TDI) is introduced for the purpose of reducing the elution of the low-molecular-weight reactant.
However, glycerin-containing hollow fibers used in recent artificial kidneys and the like have a large pore size and an increased amount of glycerin for storage. For this reason, when a polyurethane resin-forming composition containing MDI is used, more low-molecular-weight reactants are generated, and thus improvement is desired. Further, even for 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 reactant, the viscosity of the polyurethane resin-forming composition increases, and there is a concern about poor molding.
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, there are still many eluates of low-molecular-weight reactants of MDI and other components (polyol, glycerin, etc.), and the defoaming property at the time of molding is poor, and bubbles remain. It was a problem.

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

  The present invention has been made in view of the circumstances as described above, and its purpose is to suppress the generation of an eluate caused by a low-molecular-weight reaction product, which is excellent in moldability and has an excellent appearance. A polyurethane resin-forming composition that contributes to formation, and a sealing material and a membrane module using the forming composition.

  As a result of intensive studies, the present inventors have determined that an allophanate group-containing polyisocyanate prepolymer (A) that is a reaction product of diphenylmethane diisocyanate (a1) and a specific structure alkyl alcohol (a2), a polyol (B), And the inventors have found that the above-mentioned 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 (a2) having 10 or more carbon atoms,
The polyurethane resin forming composition whose monomer amount of the said diphenylmethane diisocyanate (a1) with respect to the gross mass of the said polyurethane resin forming composition is 15.0 mass% or more and 20.0 mass% or less.
(2): The reaction product is a reaction product of the diphenylmethane diisocyanate (a1), the alkyl alcohol (a2) having 10 or more carbon atoms, and a polyol (a3). The polyurethane resin-forming composition as described in (1) above.
(3): The polyurethane resin-forming composition as described in (2) above, wherein the polyol (a3) has an average functional group number 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 1000 or less.
(5): A sealing material comprising a cured product of the polyurethane resin-forming composition described in 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 an eluate caused by a low-molecular-weight reactant, 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, a sealing material and a membrane module using the forming composition can be provided.

It is a conceptual diagram which shows an example of a structure of the membrane module concerning one Embodiment of this invention.

[Urethane resin-forming composition]
The urethane resin-forming composition according to one embodiment of the present invention is
An allophanate group-containing polyisocyanate prepolymer (A);
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) with respect to the total mass of the forming composition is 15.0% by mass or more and 20.0% by mass or less.

As a result of further studies on the urethane resin-forming composition by the present inventors, when the urethane resin-forming composition is cured to obtain a cured product, the cured product may be extracted by a solvent. I found out that there was. If the cured product is extracted with a solvent, the performance may be lowered and the life may be shortened. Therefore, it is desired to reduce the amount of the extract extracted with the solvent.
As a result of extensive studies by the present inventors, the allophanate group-containing polyisocyanate prepolymer (A) is a polyurethane containing the reaction product by further adding a polyol (a3) to the reaction product. The cured product obtained by curing the resin-forming composition was found to further reduce the amount of the extract extracted by the solvent.

Therefore, the urethane resin-forming composition according to another embodiment of the present invention is
An allophanate group-containing polyisocyanate prepolymer (A);
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 polyol (a3),
The monomer amount of diphenylmethane diisocyanate (a1) with respect to the total mass of the forming composition is 15.0% by mass or more and 20.0% by mass or less.

<Allophanate group-containing polyisocyanate prepolymer (A)>
<Diphenylmethane diisocyanate (a1)>
As diphenylmethane diisocyanate (a1), any generally available monomer of diphenylmethane diisocyanate (hereinafter also referred to as MDI) can be used. The isomer of the MDI monomer is usually 2,2′-MDI of 0% by mass to 5% by mass, 2,4′-MDI of 0% by mass to 95% by mass, and 4,4′-MDI of 5% by mass to 100%. It is a simple substance or an isomer mixture of MDI monomers contained in an amount of not more than mass%.
As MDI (a1), in order to obtain a lower viscosity allophanate group-containing polyisocyanate prepolymer (A), the aforementioned MDI is preferably used. However, polymethylene polyphenylene polyisocyanate (polymeric MDI) can also be used as MDI (a1) if a certain degree of increase in viscosity of the allophanate group-containing polyisocyanate prepolymer (A) is acceptable. In this case, the content of polymethylene polyphenylene polyisocyanate is preferably 0% by mass or more and 50% by mass or less in the isocyanate component to be 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) may be used as long as it has 10 or more carbon atoms. The alkyl alcohol (a2) preferably has 10 or more carbon atoms, and more preferably has 10 to 105 carbon atoms.
Examples of the alkyl alcohol having 10 or more carbon atoms include 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, 1-hepta. Aliphatic groups such as decanol, 1-octadecanol, 1-nonadecanol, 1-eicosanol, 1-hexacosanol, 1-heptatricontanol, 1-oleyl alcohol, 2-octyldodecanol, 2-dodecyltetradecanol Examples thereof include monoalcohols and mixtures thereof.
The molecular weight of the alkyl alcohol is preferably from 158 to 1500. From the viewpoint of the excellent moldability and adhesive strength of the polyurethane resin, the molecular weight of the alkyl alcohol is more preferably from 200 to 1,000. From the viewpoint of reducing the eluate of the polyurethane resin, the molecular weight of the alkyl alcohol is more preferably from 214 to 800.

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

As the polyol (a3), any one having an average functional group number of 2 or more can be used.
In view of moldability of polyurethane resin and reduction of eluate, the average functional group number is more preferably 2 or more and 3 or less.
Examples of the polyol (a3) include polyether polyols, polyester polyols, polylactone polyols, castor oil polyols, and polyolefin polyols. These can be used alone or in combination of two or more. Among these, castor oil-based polyol is preferable because it is excellent in chemical resistance and elution resistance.
The molecular weight of the polyol (a3) is preferably 500 or more and 3000 or less. From the viewpoint of excellent molding processability and adhesive strength of the polyurethane resin, the molecular weight of the polyol (a3) is more preferably 600 or more and 2500 or less.

  The content of the monomer of MDI (a1) of 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 eluate of the polyurethane resin, the content of the monomer of MDI (a1) is most preferably 19.0% by mass or more and 36.0% by mass or less.

  The content of the MDI (a1) monomer 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 urethanizing MDI (a1), an alkyl alcohol (a2) having 10 or more carbon atoms, and a polyol (a3) added as necessary. It can be obtained by adding a predetermined amount of catalyst (C) to allophanate and stopping the reaction with catalyst poison (D).

<Catalyst (C)>
Examples of the catalyst (C) include zinc acetylacetone; metal carboxylates such as zinc, lead, tin, copper, cobalt, and mixtures thereof; tertiary amines, tertiary amino alcohols, quaternary ammonium salts, and mixtures thereof. , Etc.
The addition amount of the catalyst (C) 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 quicker, and when it is 1000 ppm or less, coloring of the prepolymer can be further suppressed.

<Catalyst poison (D)>
As the catalyst poison (D), acidic substances are suitable, for example, anhydrous hydrogen chloride, sulfuric acid, phosphoric acid, monoalkyl sulfate ester, alkyl sulfonic acid, alkylbenzene sulfonic acid, mono- or dialkyl phosphate ester, benzoyl chloride and Lewis acid are also included. It is. The addition amount is preferably added in an amount equal to or greater than the number of moles of the catalyst (C), and more 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 easy to handle the allophanate group-containing polyisocyanate prepolymer (A). 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 at 25 ° C. of the allophanate group-containing polyisocyanate prepolymer (A) is preferably 50 mPa · s or more and 8000 mPa · s or less, and 100 mPa from the viewpoint that the allophanate group-containing polyisocyanate prepolymer (A) is easy to handle. * More preferably, it is s or more and 7000 mPa * s or less. From the viewpoint of the excellent moldability of the polyurethane resin, the viscosity at 25 ° C. of the allophanate group-containing polyisocyanate prepolymer (A) is most preferably from 200 mPa · s to 6000 mPa · s.

  The urethanization reaction is preferably performed in a temperature range of 45 ° C. or more and 80 ° C. or less until the target NCO content is reached. When the temperature is 45 ° C. or higher, the precipitation of monomer MDI can be suppressed to a higher degree, and when the temperature is 80 ° C. or lower, the generation of by-products can be further suppressed.

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

  When the catalyst poison (D) is added before reaching the target NCO content during the allophanatization reaction, MDI (a1) and alkyl alcohol (a2) having 10 or more carbon atoms, or further polyol (a3) Since the urethanized product reacted with, the eluate may increase. Moreover, when reaction progresses too much and becomes lower than target NCO content, it may become high viscosity and a 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 may be an active hydrogen group-containing compound. Any of them can be used. Examples of the polyol (B) include a low molecular polyol, a polyether polyol, a polyester polyol, a polylactone polyol, a castor oil polyol, a polyolefin polyol, and a hydroxyl group-containing amine compound. These can be used alone or in combination of two or more. Among these, castor oil-based polyol is preferable because it is excellent in chemical resistance and elution resistance.

  Examples of the low molecular polyol include a divalent low molecular polyol and a trivalent or higher low molecular polyol. Specific examples of the divalent low molecular polyol include ethylene glycol, diethylene glycol, propylene glycol, 1,2-, 1,3- or 1,4-butanediol, 1,5-pentanediol, 3-methyl- Examples include 1,5-pentanediol, 1,6-hexane glycol, 1,8-octanediol, 1,10-decandiol, neopentyl glycol, hydrogenated bisphenol A, and the like. Specific examples of the trivalent or higher molecular weight polyol include glycerin, trimethylolpropane, hexanetriol, pentaerythritol, sorbitol, and the like. The molecular weight of the low molecular polyol is preferably 50 or more and 200 or less.

  Examples of the polyether-based polyol include adducts of the above low-molecular-weight polyols with alkylene oxides (C2-C4 alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, etc.) and ring-opening polymers of alkylene oxides. It is done. Specific examples of the polyether polyol include polypropylene glycol, polyethylene glycol, polytetramethylene ether glycol, and chipped ether that is a copolymer of ethylene oxide and propylene oxide. The number average molecular weight of the polyether polyol is preferably 200 or more and 7000 or less. From the viewpoint of excellent moldability at the time of producing the sealing material, the polyether polyol preferably has a number average molecular weight of 500 or more and 5000 or less.

  Examples of the polyester polyol include a polyester polyol obtained by condensation polymerization of a polycarboxylic acid and a polyol. More specifically, the polycarboxylic acid is an aliphatic saturated or unsaturated polycarboxylic acid such as azelaic acid, dodecanoic acid, maleic acid, fumaric acid, itaconic acid, ricinoleic acid, dimerized linoleic acid; aromatic polycarboxylic acid Examples thereof include phthalic acid, isophthalic acid, terephthalic acid, and the like. More specifically, examples of the polyol include at least one selected from the group consisting of the low molecular polyol and the polyether polyol. The number average molecular weight of the polyester polyol is preferably from 200 to 5,000. From the viewpoint of excellent moldability during the production of the sealing material, the number average molecular weight of the polyester polyol is more preferably 500 or more and 3000 or less.

  Examples of polylactone polyols include polymerization initiators such as glycols and triols, ε-caprolactone, α-methyl-ε-caprolactone, ε-methyl-ε-caprolactone, and β-methyl-σ-valerolactone. Examples include polyols obtained by addition polymerization of at least one selected from the group consisting of organic metal compounds, metal chelate compounds, fatty acid metal acyl compounds and the like in the presence of a catalyst. The number average molecular weight of the polylactone-based polyol is preferably 200 or more and 5000 or less. From the viewpoint of excellent moldability 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 the reaction of castor oil fatty acid and polyol, such as castor oil fatty acid diglyceride, monoglyceride; castor oil fatty acid and trimethylol alkane mono, di or triester; And mono-, di-, or triesters of castor oil fatty acid and polypropylene glycol. More specifically, examples of the polyol include at least one selected from the group consisting of the low molecular polyol and the polyether polyol. The number average molecular weight of the castor oil-based polyol is preferably from 300 to 4,000. From the viewpoint of excellent moldability at the time of producing 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 the polyolefin-based polyol include polybutadiene-based polyol in which a hydroxyl group is introduced at the terminal of a copolymer of polybutadiene or butadiene and styrene or acrylonitrile.

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

  Examples of the hydroxyl group-containing amine compound include amino alcohols as oxyalkylated derivatives of amino compounds.

  Examples of the amino alcohol 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. Examples include '-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 preferable, and N, N, N ′, N′-tetrakis [2-hydroxypropyl] ethylenediamine is more preferable. By using N, N, N ′, N′-tetrakis [2-hydroxypropyl] ethylenediamine, it is possible to obtain more excellent effects for improving processability at the time of molding, suppressing elution, and the like.

  Further, the amount of the hydroxyl group-containing amine compound used is preferably in the range of 1% by mass to 30% by mass, particularly preferably in the range of 5% by mass to 25% by mass in the polyol (B). 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 exhibits its function more effectively and exhibits further effects. When the ratio of the hydroxyl group-containing amine compound in the polyol (B) is 30% by mass or less, the reactivity is further suppressed from becoming too high, the workability is further improved, and the filling property is ensured. It is further suppressed that the hardness of the obtained 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 molding processability and adhesive strength of the polyurethane resin, the hydroxyl value of the polyol (B) is most preferably from 100 mgKOH / g to 500 mgKOH / g.

  The viscosity of the polyol (B) at 25 ° C. is preferably from 100 mPa · s to 6000 mPa · s, and more preferably from 200 mPa · s to 4000 mPa · s from the viewpoint of easy handling of the polyol (B). From the viewpoint of the excellent moldability 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 this embodiment can be obtained by reacting the allophanate group-containing polyisocyanate prepolymer (A) with the polyol (B). The obtained polyurethane resin-forming composition can be used as a sealing material for membranes of various forms such as a sealing material for hollow fiber membrane modules, a sealing material for flat membrane modules, and a sealing material for spiral membranes. Among them, the 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 molding processability, There are few eluates resulting from the low-molecular-weight reaction product of MDI and other components (especially glycerin). Therefore, the 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 a glycerin-containing hollow fiber.

  As the polyurethane resin-forming composition, the molar ratio (isocyanate group / active hydrogen group) of the isocyanate group of the allophanate group-containing polyisocyanate composition (A) and the active hydrogen group of the polyol (B) is 0.8 or more. It is preferably within the range of 6 or less. 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. Particularly preferred. According to the composition obtained at such a mixing ratio, a composition having further excellent durability can be obtained.

  The monomer amount (mass) of MDI (a1) constituting the allophanate group-containing polyisocyanate prepolymer (A) with respect to the total mass of the polyurethane resin-forming composition can be determined 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 15.0% by mass or more and 19.0% by mass or less from the viewpoint that the amount of low molecular eluate is small. More preferably, it is more preferably 15.0% by mass or more and 18.0% by mass or less. According to the composition obtained within such a range, a composition having few low-molecular eluates and excellent moldability can be obtained.

The low molecular eluate value of the polyurethane resin-forming composition (measurement method will be described later) is preferably 0.070 or less, and 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, and particularly preferably 1.0% by mass or less.

  In the present embodiment, a metal compound system such as an organotin compound that accelerates the reaction between the isocyanate group of the allophanate group-containing polyisocyanate prepolymer (A) and the active hydrogen group of the polyol (B) as necessary. Known urethanes such as catalysts and tertiary amine catalysts such as triethylenediamine (TEDA), tetramethylhexamethylenediamine (TMHMDA), pentamethyldiethylenetriamine (PMDETA), dimethylcyclohexylamine (DMCHA) and bisdimethylaminoethyl ether (BDMAEA) A catalyst can be used.

  In addition, the polyurethane resin-forming composition according to this embodiment may contain additives such as an antioxidant, an ultraviolet absorber, and an antifoaming agent as long as the purpose is not impaired.

  When obtaining a sealing material for a module using a hollow fiber separation membrane using the polyurethane resin-forming composition according to this embodiment, the composition is allowed to react at room temperature (20 ° C. or higher and 30 ° C. or lower), or In order to shorten the gelation time and decrease the mixing viscosity, the allophanate group-containing polyisocyanate composition (A) and the polyol (B) may be heated to 30 ° C. or more and 60 ° C. or less for reaction. 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, as necessary.

  The initial mixed viscosity of the polyurethane resin-forming composition is preferably from 300 mPa · s to 2400 mPa · s, and more preferably from 400 mPa · s to 2100 mPa · s from the viewpoint of easy handling until 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 property of the polyurethane resin. The initial mixed viscosity of the polyurethane resin-forming composition is a viscosity one minute after the start of mixing 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 longer and 600 seconds or shorter, and more preferably 90 seconds or longer and 480 seconds or shorter from the viewpoint of adhesive strength. From the viewpoint of the excellent moldability of the polyurethane resin, the pot life of the polyurethane resin-forming composition is most preferably from 120 seconds to 420 seconds. The pot life of the polyurethane resin-forming composition means that when the allophanate group-containing polyisocyanate composition (A) and the polyol (B) are mixed for 30 seconds, the mixing starts from the start of mixing until it reaches 50,000 mPa · s. It takes time to complete.

  The hardness at 25 ° C. of the polyurethane resin-forming composition is preferably from 30 to 80 in Shore D, and more preferably from 35 to 75 from the viewpoint of easy processing such as cutting of the cured polyurethane resin. From the viewpoint of excellent molding processability and adhesive strength of the polyurethane resin, it is most preferable that the polyurethane resin-forming composition has a hardness (Shore D) at 25 ° C. of 40 or more and 70 or less.

[Seal materials, membrane modules]
The sealing material concerning one Embodiment of this invention consists of hardened | cured material of the polyurethane resin forming composition mentioned 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 such an extent that the other side can be visually observed from one side of the sealing material. In particular, a sealing material for a membrane module that constitutes a medical or industrial separation apparatus is required to have no turbidity visually in order to confirm the inclusion of foreign matter.

  The membrane module according to an embodiment of the present invention fills the gap between the membrane and a part of the module (particularly, the gap between the end of the membrane and the inner wall of the housing) with the above-described polyurethane resin-forming composition. 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 an embodiment of the present invention will be described in more detail with reference to the drawings.
FIG. 1 is a conceptual diagram showing an example of the configuration of a membrane module according to an 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 filled.

  The housing 11 has a cylindrical shape. Sealing materials 19 are respectively provided at both ends (left and right ends in FIG. 1) inside the housing 11. The sealing material fills and seals the gap between the hollow fiber membranes 13 and the gap between the hollow fiber membrane 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 flowing in from the first fluid inlet 15 passes through the gap (outside of the hollow fiber membrane) while contacting with the plurality of hollow fiber membranes 13 filled in the housing 11, and the first fluid outlet 17. Discharged from. In addition, since the sealing material 19 does not exist in the hollow fiber membrane 13, the 2nd inflow port (one end side) and 2nd outflow port which were provided in the cap member not shown in the hollow fiber membrane 13 The second fluid (gas or liquid) flows in and out via (the other end side). Then, the first fluid and the second fluid come into contact with each other through the hollow fiber membrane 13, so that the fluid from one fluid into the other fluid (or further into the fluid from one fluid to the other). Mass transfer occurs. For example, in the case of a hollow fiber membrane type dialyzer, when the dialysate comes into contact with blood, waste products and excess water in the blood move to the dialysate.

  Note that 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 thereof, but the membrane module according to the present embodiment has no such configuration. It is not limited. For example, a plurality or a single film having various shapes such as a flat film and a spiral film may be used. Further, the sealing material is not limited to the configuration provided at both ends of the membrane, and may be provided only on a part of the membrane (one end in the case of a hollow fiber shape). It may be provided in all the outer edge parts. Further, the sealing material may be provided and sealed at a part other than the end of the film. Further, the housing 11 of the membrane module 100 shown in FIG. 1 has a cylindrical shape, but may have any shape other than the cylindrical shape.

  The membrane module according to one embodiment of the present invention can be suitably used as a medical module or a water treatment module because generation of an extract is satisfactorily suppressed. Specific examples of the membrane module include a plasma separator, an artificial lung, an artificial kidney, an artificial liver, and a household / industrial water treatment device.

  EXAMPLES Hereinafter, the polyurethane resin-forming composition according to one embodiment of the present invention will be described in more detail with reference to examples. However, the present invention is not construed as being limited to these examples. In the following, “%” means “mass%” unless otherwise specified.

The following components 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: Mixture of 2,4′-MDI and 4,4′-MDI (Millionate NM manufactured by Tosoh Corporation, isocyanate group content = 33.6%)
a1-3; carbodiimide modified product of 4,4′-MDI (Millionate MTL-C, manufactured by Tosoh Corporation, isocyanate group content = 28.6%)

[Alkyl alcohol (a2)]
a2-1; 2-octyldodecanol (Calcool 200GD manufactured by Kao Corporation, molecular weight = 300, hydroxyl value = 185 mgKOH / g average functional group number 1)
a2-2; isotridecanol (tridecanol, molecular weight = 200, hydroxyl value = 275 mgKOH / g, average functional group number 1 manufactured by KH Neochem)
a2-3; 2-ethylhexanol (octanol manufactured by KH Neochem, 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 (castor oil LAV manufactured by Ito Oil Co., Ltd., 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 (castor oil LAV manufactured by Ito Oil Co., Ltd., hydroxyl value = 160 mgKOH / g)
b-2; N, N, N ′, N′-tetrakis [2-hydroxypropyl] ethylenediamine (EDP-300 manufactured by ADEKA, hydroxyl value = 760 mgKOH / g)

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

  In addition, in a manufacture example, an Example, and a comparative example, predetermined amount means each composition amount of Table 1-Table 4.

[Preparation Example 1 of Prepolymer (A)]
A predetermined amount of a1-1 was added to a 1-liter four-necked flask, and the temperature was adjusted to 50 ° C. with stirring under a nitrogen stream. Next, a predetermined amount of a2-1 was added with stirring, and the temperature was raised to 90 ° C. after the exothermic reaction of urethanization had subsided. When the internal temperature was stabilized at 90 ° C., a predetermined amount of catalyst c was added and reacted at 90 ° C. for 4 hours, a predetermined amount of catalyst poison d was added to stop the reaction, and prepolymer A-1 was obtained. Prepolymer A-1 was a pale yellow transparent liquid, and its viscosity at 25 ° C. was 2800 mPa · s. The properties (NCO content, MDI monomer amount, viscosity, low temperature storage stability) are shown in Tables 1 and 2. The property measuring method will be described later.

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

[Preparation Example 10 of Prepolymer (A)]
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. with stirring under a nitrogen stream. Next, a predetermined amount of b-1 was added with stirring, and after the exothermic reaction of the urethanization reaction was stopped, the mixture was reacted at 75 ° C. for 3 hours to obtain Prepolymer A-10. Prepolymer A-10 was a pale yellow transparent liquid, and its viscosity at 25 ° C. was 12020 mPa · s. The properties are shown in Table 2.

[Preparation Examples 11-12 of Prepolymer (A)]
a1 and b-1 were changed to the compositions shown in Table 2, and prepolymers A-11 to A-12 were synthesized in the same manner as in Production Example 10. The properties are shown in Table 2.

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

[Examples 1-6, Comparative Examples 1-9]
Urethane resin compositions were molded with the compositions shown in Table 3 and Table 4.
The values described in Table 3 and Table 4 were calculated from the following test results.

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

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

<Measurement conditions>
Measuring device: “HLC-8120 (trade name)” (manufactured by Tosoh Corporation)
(2) Column: Columns packed with 3 types of TSKgel G3000HXL, TSKgel G2000HXL, and TSKgel G1000HXL (all trade names, manufactured by Tosoh Corporation) as a packing are connected in series, and measured and detected at a column temperature of 40 ° C. Apparatus: RI (refractive index) meter Eluent: Tetrahydrofuran (THF) (flow rate: 1 mL / min., 40 ° C.)
Calibration curve: A calibration curve was obtained using the following grade 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: 0.05 g of sample in 10 mL of THF

<Measurement method>
First, a calibration curve was obtained from a chart obtained by detecting the refractive index difference using polystyrene as a standard substance. Next, for each sample, from the chart obtained by detecting the difference in refractive index based on the same calibration curve, the mass% of the peak near the peak top molecular weight (number average molecular weight) 230 indicating the MDI monomer was determined.

[Low temperature storage stability]
Prepolymers A-1 to A-14 shown in Tables 1 and 2 were left in a 0 ° C. environment for 3 months to confirm the appearance of the samples. A pale yellow transparent material was designated as “A”, and a turbid or solid product was observed as “B”.

[Low molecular eluate value evaluation procedure]
<Method of forming a sample for measuring a low molecular weight eluate value>
Each of the polyurethane resin-forming compositions having the combinations shown in Table 3 and Table 4 was weighed with a stirring blade for 15 seconds, and then mixed with 40 g of glycerin. Stirred for 2 seconds to obtain a polyurethane resin-forming composition. 100 g of this polyurethane resin-forming composition was cast into a cartridge case (made of polycarbonate having an inner diameter of 48 mm) in a centrifugal molding machine and subjected to centrifugal molding to obtain a cured resin (low molecular eluate value measurement sample). Centrifugal molding conditions were as follows: primary curing was performed at a centrifugal molding speed of 1500 rpm, temperature was 50 ° C., time was 15 minutes, and secondary curing conditions were left in a 45 ° C. constant temperature bath for 48 hours.

<Dissolution 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 mixture was shaken at 40 ° C. for 2 hours. Subsequently, the obtained extract was decanted and used as a test solution diluted 5-fold, and UV absorbance of the test solution was measured with an ultraviolet-visible spectrophotometer (Shimadzu Corporation UV-2500). The maximum value of absorbance at 240 to 245 nm / 10 was defined as the low molecular eluate value.

[Solvent extraction rate evaluation procedure]
<Solvent extraction rate measurement sample molding method>
Each polyurethane resin-forming composition having a combination shown in Table 3 and Table 4 was degassed under reduced pressure at 10 to 20 kPa for 3 minutes, and then poured into release paper (220 mm × 170 mm × 10 mm). This was left to cure at 45 ° C. for 2 days to obtain a cured resin.
<Extraction test method>
The obtained resin cured product was cut into 1 cm square, 20 g of this was weighed, 10 times the amount of methanol was added to the resin mass, and 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 polyurethane resin-forming compositions having the combinations shown in Tables 3 and 4 were used to calculate the MDI monomer amount before the reaction from the NCO / OH molar ratio. .

[Appearance evaluation]
The polyurethane resin-forming compositions having combinations shown in Table 3 and Table 4 were each 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). This was left to cure at 45 ° C. for 2 days and then demolded to obtain a cured product. About the obtained hardened | cured material, the external appearance was evaluated visually and the thing without turbidity was set to A, and the thing in which slight turbidity was recognized was set to B.

[Hardness evaluation]
About the hardened | cured material used for external appearance evaluation, the Shore D hardness in 25 degreeC was measured. The results are shown in Table 3 and Table 4. The hardness was measured according to JIS K 7312: 1996.

[Evaluation of initial mixed viscosity] (Evaluation of moldability)
For the polyurethane resin-forming compositions having the combinations shown in Table 3 and Table 4, the main agent and the curing agent having a liquid temperature of 45 ° C. were uniformly mixed for 30 seconds and allowed to stand. The viscosity after 1 minute from the start of mixing was measured with a rotational viscometer (RB-215L type, manufactured by Toki Sangyo Co., Ltd.).

[Pot life evaluation]
For the polyurethane resin-forming compositions having the combinations shown in Table 3 and Table 4, the main agent and the curing agent having 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 25 ° C. Under the atmosphere, the viscosity increase was measured using a rotational viscometer (RB-215L type, manufactured by Toki Sangyo Co., Ltd.). The time from the start of mixing until the viscosity of the polyurethane resin-forming composition reached 50000 mPa · s was defined as the pot life, and the reactivity was evaluated.

  As shown in Table 3 and Table 4, the polyurethane resin compositions according to Examples 1 to 6 each have a low low molecular eluate value. Furthermore, the polyurethane resin compositions according to Example 5 and Example 6 also have a low solvent extraction rate. In addition, Examples 1 to 6 were found to have excellent moldability that can be satisfactorily filled in the membrane module because the initial mixed viscosity is sufficiently low. The polyurethane resin-forming compositions according to Comparative Examples 1 to 4 and Comparative Examples 6 to 9 each had a high low molecular eluate value. Although the polyurethane resin-forming composition according to Comparative Example 5 has a low low molecular eluate value, it has a high solvent extraction rate and a high initial mixing 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 an extract is suppressed. The sealing material using the polyurethane resin-forming composition according to one embodiment of the present invention has many excellent performances, particularly an excellent low extraction rate. Therefore, the sealing material concerning one Embodiment of this invention can be used conveniently as a sealing material for the membrane module which comprises a medical use and an industrial separation apparatus. Specific examples of the medical and industrial separation devices include plasma separators, artificial lungs, artificial kidneys, artificial livers, and household / industrial water treatment devices.

DESCRIPTION OF SYMBOLS 11 Housing 13 Hollow fiber membrane 15 1st fluid inlet port 17 1st fluid outlet port 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);
A reaction product of an alkyl alcohol (a2) having 10 or more carbon atoms,
The polyurethane resin forming composition whose monomer amount of the said diphenylmethane diisocyanate (a1) with respect to the gross mass of the said polyurethane resin forming composition is 15.0 mass% or more and 20.0 mass% or less. The reaction product is
The difailmethane diisocyanate (a1);
The alkyl alcohol having 10 or more carbon atoms (a2);
The polyurethane resin-forming composition according to claim 1, which is a reaction product of polyol (a3).   The polyurethane resin-forming composition according to claim 2, wherein the polyol (a3) has an average number of functional groups of 2 or more.   The polyurethane resin-forming composition according to claim 2 or 3, wherein the polyol (a3) has a molecular weight of 500 or more and 3000 or less.   The sealing material which consists of hardened | cured material of the polyurethane resin-forming composition of any one of Claims 1 thru | or 4.   A membrane module sealed with the sealing material according to claim 5.

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