JP7334431B2 - Polyurethane resin-forming composition for membrane sealing material, and membrane sealing material and membrane module using the same - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a polyurethane resin-forming composition for membrane sealing materials, and membrane sealing materials and membrane modules using the same.

In recent years, a hollow fiber membrane module having a high filling rate of hollow fiber membranes has been developed. For this reason, the polyurethane resin-forming composition for a membrane sealing material that seals the gap between the membrane and the membrane module is required to have a low viscosity in order to exhibit excellent permeability so that it can easily penetrate even minute gaps. It has been demanded.
In addition, diphenylmethane diisocyanate (MDI) is widely used in polyurethane resin-forming compositions for membrane seal materials. and low-molecular-weight reactants with glycerin are formed. Since these low-molecular-weight reactants elute into the membrane module during use, it is strongly desired to suppress the production thereof.

Patent Document 1 discloses an isocyanate group-terminated prepolymer obtained from a reaction product of MDI and castor oil, a polyisocyanate component (main agent) containing polymethylene polyphenyl polyisocyanate, and a polyol component (curing agent). Disclosed is a polyurethane resin-forming composition for sealing of membrane modules comprising: Furthermore, Patent Document 1 discloses that the elution amount of the polyurethane resin obtained from such a polyurethane resin-forming composition for sealing materials is reduced.
Further, Patent Document 2 discloses a polyurethane resin-forming composition containing a castor oil-based polyol, a polyoxyethylene polypropylene aliphatic polyamine, and a polyoxypropylene aliphatic polyamine in a specific content ratio in the polyol component. Furthermore, Patent Document 2 discloses that such a polyurethane resin-forming composition can achieve reactivity suitable for workability, reduction of extractables, suppression of discoloration against γ-rays, and the like.

JP-A-7-213871 WO2017/6650

However, in the composition according to Patent Document 1, the viscosity of the main agent is high, and it is desired to reduce the viscosity. Therefore, the composition according to Patent Document 1 has a problem that the initial viscosity of the mixture of the main agent and the curing agent is high, which may cause insufficient filling during molding.
Moreover, the composition according to Patent Document 2 has a problem that the molding becomes cloudy when the amount of oxyethylene in the aliphatic polyamine increases.
Therefore, one embodiment of the present invention contributes to the formation of a membrane sealing material in which the elution amount of low-molecular-weight reaction products between MDI and glycerin is suppressed and the clouding of molded products is suppressed, and at the same time, it exhibits good rapid curing properties. It is intended to provide a polyurethane resin-forming composition for a membrane sealant, which has a low viscosity and excellent castability.
Another embodiment of the present invention is directed to providing a membrane sealing material and a membrane module containing a cured product of the polyurethane resin-forming composition for membrane sealing material.

The present invention includes the following embodiments.
(1) an allophanate group-containing polyisocyanate prepolymer (A);
A polyurethane resin-forming composition for a membrane sealing material, comprising a polyol (B),
The allophanate group-containing polyisocyanate prepolymer (A) is
diphenylmethane diisocyanate (a1);
containing a reaction product of the active hydrogen-containing compound (a2),
The polyol (B) is
a hydroxyl group-containing amine compound (b1);
At least one polyol (b2) selected from the group consisting of castor oil (b2-1) and castor oil-based polyols (b2-2),
The hydroxyl group-containing amine compound (b1) is a polyurethane resin-forming composition for a membrane sealing material, containing a polyoxyethylene-polyoxypropylene aliphatic polyamine.
(2) A membrane sealant containing a cured product of the polyurethane resin-forming composition for a membrane sealant described in (1) above.
(3) a main body;
a membrane;
a membrane sealing material that seals a gap between the main body and the membrane;
A membrane module, wherein the membrane sealing material is the membrane sealing material according to (2) above.

According to one embodiment of the present invention, the elution amount of low-molecular-weight reaction products between MDI and glycerin is suppressed, and it contributes to the formation of a membrane sealing material that suppresses white turbidity of molded products, and has good rapid curing properties. It is possible to provide a polyurethane resin-forming composition for a membrane sealant that has a low viscosity and excellent castability. Further, according to another embodiment of the present invention, it is possible to provide a membrane sealing material and a membrane module containing a cured product of the polyurethane resin-forming composition for membrane sealing material.

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

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS Illustrative embodiments for carrying out the invention are described in detail below.

[Polyurethane resin-forming composition for membrane sealing material]
A polyurethane resin-forming composition for a membrane sealing material according to one embodiment of the present invention is
an allophanate group-containing polyisocyanate prepolymer (A);
A polyurethane resin-forming composition for a membrane sealing material, comprising a polyol (B),
The allophanate group-containing polyisocyanate prepolymer (A) is
diphenylmethane diisocyanate (a1);
containing a reaction product of the active hydrogen-containing compound (a2),
The polyol (B) is
a hydroxyl group-containing amine compound (b1);
At least one polyol (b2) selected from the group consisting of castor oil (b2-1) and castor oil-based polyols (b2-2),
The hydroxyl group-containing amine-based compound (b1) contains a polyoxyethylene polyoxypropylene aliphatic polyamine.

<Allophanate group-containing polyisocyanate prepolymer (A)>
The allophanate group-containing polyisocyanate prepolymer (A) contains a reaction product of diphenylmethane diisocyanate (a1) and an active hydrogen-containing compound (a2).

<<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. % by mass or less.
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.

<<Active hydrogen-containing compound (a2)>>
The active hydrogen-containing compound (a2) is not particularly limited as long as it is a compound containing active hydrogen. Active hydrogen-containing compounds (a2) include, for example, aliphatic monoalcohols, aromatic monoalcohols, alicyclic monoalcohols, araliphatic monoalcohols, monoalcohols such as polyoxypropylene glycol monoalkyl ethers, castor oil, castor Examples include polyols such as oil-based polyols, low-molecular-weight polyols, polyether-based polyols, polyester-based polyols, polylactone-based polyols, and polyolefin-based polyols.

Aliphatic monoalcohols include, for example, methanol, ethanol, 1- and 2-propanol, 1- and 2-butanol, 1-pentanol, 1-hexanol, 2-methyl-1-pentanol, 4-methyl-2 -pentanol, 2-ethyl-1-butanol, 1-heptanol, 1-octanol, 2-octanol, 2-ethylhexanol, 3,5-dimethyl-1-hexanol, 2,2,4-trimethyl-1-pen Tanol, 1-nonanol, 2,6-dimethyl-4-heptanol, 1-decanol, 1-undecanol, 1-dodecanol, 1-tridecanol, 1-tetradecanol, 1-pentadecanol, 1-hexadecanol, Aliphatic monoalcohols such as 1-heptadecanol, 1-octadecanol, 1-nonadecanol, 1-eicosanol, 1-hexacosanol, 1-heptatricontanol, 1-oleyl alcohol, 2-octyldodecanol, and A mixture of these and the like are included.
The number average molecular weight of the aliphatic monoalcohol is preferably 32 or more and 1500 or less, more preferably 100 or more and 1000 or less. When the molecular weight is within this range, the molding processability and adhesive strength of the polyurethane resin are further improved.

Examples of aromatic monoalcohols include phenol and cresol.

Examples of alicyclic monoalcohols include cyclohexanol and methylcyclohexanol.

Examples of araliphatic monoalcohols include benzyl alcohol.

Examples of polyoxypropylene glycol monoalkyl ethers include reaction products of the aforementioned aliphatic monoalcohols and polyoxypropylene glycol, such as polyoxypropylene methyl ether, polyoxypropylene ethyl ether, polyoxypropylene butyl ether, polyoxypropylene -2-ethylhexyl ether, polyoxypropylene oleyl ether, polyoxypropylene-2-octyldodecaether and mixtures thereof.
The number average molecular weight of the polyoxypropylene glycol monoalkyl ether is preferably 90 or more and 1500 or less. The number average molecular weight is more preferably 150 or more and 1000 or less from the viewpoint of further improving the molding processability and adhesive strength of the polyurethane resin.

The castor oil-based polyol is a linear or branched castor oil-based polyol obtained by reacting castor oil or castor oil fatty acid with at least one polyol selected from the group consisting of low-molecular-weight polyols and polyether polyols. is mentioned. Specific examples include castor oil fatty acid diglycerides and monoglycerides; mono-, di-, and triesters of castor oil fatty acids and trimethylolalkanes; mono-, di-, and triesters of castor oil fatty acids and polypropylene glycol; mentioned.
The main component of castor oil is triglyceride of ricinoleic acid, and castor oil includes hydrogenated castor oil. Also, the main component of castor oil fatty acids is ricinoleic acid, and castor oil fatty acids include hydrogenated castor oil fatty acids.

Examples of the trimethylolalkane include trimethylolmethane, trimethylolethane, trimethylolpropane, trimethylolbutane, trimethylolpentane, trimethylolhexane, trimethylolheptane, trimethyloloctane, trimethylolnonane and trimethyloldecane. can be mentioned.

The number average molecular weight of the castor oil-based polyol is preferably 400 or more and 3000 or less, more preferably 500 or more and 2500 or less. By using a castor oil-based polyol having a number average molecular weight of 400 or more and 3000 or less, it is possible to form a cured resin having more excellent physical properties, particularly mechanical properties, required for membrane sealing materials.

The average hydroxyl value of castor oil and castor oil-based polyol is preferably 20 mgKOH/g or more and 300 mgKOH/g or less, more preferably 40 mgKOH/g or more and 250 mgKOH/g or less. By using a castor oil-based polyol having an average hydroxyl value of 20 mgKOH/g or more and 300 mgKOH/g or less, it is possible to form a cured resin having more excellent physical properties, particularly mechanical properties, required for membrane sealing materials. Furthermore, it is possible to improve the productivity of the membrane sealing material and, by extension, the productivity of the hollow fiber membrane module.

Examples of 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-hexanediol, 1,8-octanediol, 1,10-decanediol, neopentyl glycol, bivalent polyols such as hydrogenated bisphenol A, glycerin, trimethylolpropane, hexanetriol, pentaerythritol, sorbitol, Examples include tri- to octavalent polyols such as sucrose. The number average 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 8 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. Specific examples include polypropylene glycol, polyethylene glycol, polytetramethylene ether glycol, and 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, more preferably 500 or more and 5,000 or less, from the viewpoint of further excellent molding processability during the production of the membrane sealing material.

Polyester-based polyols include, for example, polyester-based polyols obtained by condensation polymerization of polycarboxylic acids and polyols.
Polycarboxylic acids used in polyester polyols include aliphatic saturated and unsaturated acids such as adipic acid, azelaic acid, dodecanedioic acid, maleic acid, fumaric acid, itaconic acid, dimerized linoleic acid, phthalic acid, isophthalic acid, and terephthalic acid. Examples include saturated polycarboxylic acids and aromatic polycarboxylic acids.
Moreover, examples of the polyol used for the polyester-based polyol include the above-described low-molecular-weight polyols and polyether-based polyols.

The number average molecular weight of the polyester polyol is preferably 200 or more and 5000 or less, more preferably 500 or more and 3000 or less. By using a polyester-based polyol having a number average molecular weight of 200 or more and 5,000 or less, it is particularly excellent in moldability when forming a membrane sealing material.

Examples of polylactone-based polyols include ε-caprolactone, α-methyl-ε-caprolactone, ε-methyl-ε-caprolactone, β-methyl-δ-valerolactone, and the like, as polymerization initiators for glycols and triols. Polyols obtained by addition polymerization in the presence of catalysts such as organometallic compounds, metal chelate compounds, and fatty acid metal acyl compounds can be mentioned. The number average molecular weight of the polylactone-based polyol is preferably 200 or more and 5000 or less, more preferably 500 or more and 3000 or less. By using a polylactone-based polyol having a number average molecular weight of 200 or more and 5000 or less, it is particularly excellent in moldability when forming a membrane sealing material.

Examples of polyolefin-based polyols include polybutadiene and polybutadiene-based polyols obtained by introducing hydroxyl groups to the terminals of a copolymer of butadiene and styrene or acrylonitrile. Other examples include polyether ester polyols obtained by addition reaction of alkylene oxides such as ethylene oxide and propylene oxide to polyesters having terminal carboxyl groups and hydroxyl groups.

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

<<Method for producing allophanate group-containing prepolymer (A)>>
The allophanate group-containing prepolymer (A) is prepared, for example, by subjecting diphenylmethane diisocyanate (a1) and an active hydrogen-containing compound (a2) to a urethanization reaction, then adding a predetermined amount of the catalyst (a3) to convert allophanate into a catalyst poison (a4). ) is preferably obtained by stopping the reaction.

<<catalyst (a3)>>
Examples of the catalyst (a3) include zinc acetylacetonate, metal carboxylates of zinc, lead, tin, copper, cobalt, etc. and carboxylic acids, mixtures thereof, tertiary amines, tertiary amino alcohols, quaternary Ammonium salts and mixtures thereof and the like are included.
The amount of the catalyst (a3) added is preferably in the range of 1 ppm or more and 500 ppm or less, and in the range of 5 ppm or more and 300 ppm or less with respect to the total mass of the diphenylmethane diisocyanate (a1) and the active hydrogen-containing compound (a2). It is more preferable to have If it is 1 ppm or more, the reaction will be rapid, and if it is 500 ppm or less, coloring of the prepolymer will be more effectively suppressed, which is preferable.

<<catalyst poison (a4)>>
Acidic substances are preferred as the catalyst poison (a4). Examples of catalyst poisons (a4) include anhydrous hydrogen chloride, sulfuric acid, phosphoric acid, monoalkyl sulfates, alkylsulfonic acids, alkylbenzenesulfonic acids, mono- or dialkylphosphates, benzoyl chloride, and Lewis acids. The amount of the catalyst poison (a4) to be added is preferably equal to or more than the number of moles of the catalyst (a3), and is 1.0 to 1.5 times the number of moles of the catalyst (a3). is preferred.

<<content of allophanate groups>>
The content of allophanate groups is preferably 0.1 mmol/g or more and 0.7 mmol/g or less with respect to the total amount of the polyurethane resin-forming composition for membrane sealing materials. Within this range, the molding processability and adhesive strength of the polyurethane resin are further improved.

<<MDI Monomer Content>>
The content of the MDI monomer is preferably 25% by mass or less relative to the total amount of the polyurethane resin-forming composition for membrane seal materials in order to further reduce low-molecular-weight reaction products between MDI and glycerin.

<<reaction temperature>>
The urethanization reaction is preferably carried out in a temperature range of 40° C. or higher and 80° C. or lower until the target NCO content is reached. When the temperature is 40°C or higher, the precipitation of monomer MDI crystals can be better suppressed, and when the temperature is 80°C or lower, the formation of side reaction products can be better suppressed.

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 becomes more rapid, and when the temperature is 130°C or lower, the formation of by-products can be further suppressed.

<Polyol (B)>
The polyol (B) contains a hydroxyl group-containing amine compound (b1) and at least one polyol (b2) selected from the group consisting of castor oil (b2-1) and castor oil-based polyols (b2-2).

<<hydroxyl group-containing amine compound (b1)>>
The hydroxyl group-containing amine compound (b1) includes polyoxyethylene polyoxypropylene aliphatic polyamine.

Examples of hydroxyl group-containing amine compounds (b1) other than polyoxyethylene polyoxypropylene aliphatic polyamines include N,N,N',N'-, which are propylene oxide or ethylene oxide adducts of amino compounds such as ethylenediamine. tetrakis[2-hydroxypropyl]ethylenediamine, N,N,N',N'-tetrakis[2-hydroxyethyl]ethylenediamine, etc.; mono-, di- and triethanolamine, N-methyl-N,N'-diethanolamine, etc. be able to. Among these, propylene oxide or ethylene oxide adducts of amino compounds such as ethylenediamine are preferred, and N,N,N',N'-tetrakis[2-hydroxypropyl]ethylenediamine is more preferred. By using N,N,N',N'-tetrakis[2-hydroxypropyl]ethylenediamine, excellent effects such as improvement of processability during molding and suppression of extractables can be obtained.

In addition, the content of the hydroxyl group-containing amine compound (b1) is preferably 1% by mass or more and 30% by mass or less, particularly preferably 5% by mass or more and 25% by mass or less, in the polyol (B). . When the content of the hydroxyl group-containing amine compound (b1) in the polyol (B) is 1% by mass or more, the hydroxyl group-containing amine compound (b1) more satisfactorily exerts its function, resulting in further effects. . When the proportion of the hydroxyl group-containing amine compound (b1) 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. In addition, it is further suppressed that the hardness of the membrane sealing material to be obtained becomes too high.

The content of ethylene oxide derived from the hydroxyl group-containing amine compound (b1) is preferably 0.1 mmol/g or more and 0.5 mmol/g or less with respect to the total amount of the polyurethane resin-forming composition for membrane seal materials. , 0.15 mmol/g or more and 0.45 mmol/g or less. When the ethylene oxide content is 0.1 mmol/g or more, the elution amount of low-molecular-weight reactants is further suppressed, and when it is 0.5 mmol/g or less, cloudiness of the molding is further suppressed.

<<Polyol (b2)>>
At least one polyol (b2) selected from the group consisting of castor oil (b2-1) and castor oil-based polyols (b2-2) is not particularly limited, but the active hydrogen-containing compounds (a2) listed above are not particularly limited. , castor oil and castor oil-based modified polyol.

The content Mb1 of the hydroxyl group-containing amine compound (b1) in the polyol (B), and at least one polyol (b2) selected from the group consisting of castor oil (b2-1) and castor oil-based polyols (b2-2). The content Mb2 of and the mass ratio (Mb1/Mb2) is preferably 10/90 or more and 30/70 or less, more preferably 13/87 or more and 28/72 or less. When the mass ratio of the hydroxyl group-containing amine compound (b1) in the polyol (B) is within this range, the reactivity becomes suitable, and the hardness of the obtained membrane sealing material is further improved, and the reactivity is improved. Since it is possible to further suppress the initial thickening that becomes too high, the filling property is further improved.

In addition, the content Mb2 of the polyol (b2) is preferably 1% by mass or more and 45% by mass or less with respect to the total amount of the urethane resin-forming composition from the viewpoint of molded product appearance and low elution. It is particularly preferable that the content is not less than 40% by mass and not more than 40% by mass.

<<Active hydrogen-containing compound (b3)>>
The polyol (B) may contain a hydroxyl group-containing amine compound (b1) and an active hydrogen-containing compound other than the polyol (b2) (hereinafter referred to as "active hydrogen-containing compound (b3)"). As the active hydrogen-containing compound (b3), various polyols exemplified for the active hydrogen-containing compound (a2) can be used.

In the polyol (B), the mass ratio (Mb2)/(Mb3) of the content Mb2 of the polyol (b2) and the content Mb3 of the active hydrogen-containing compound (b3) is 50/50 or more and 100/0 or less. 1 is preferred, and 100/0 is particularly preferred. That is, it is particularly preferable that the polyol (B) consists only of the hydroxyl group-containing amine compound (b1) and the polyol (b2).

Further, the mass ratio (Mb1)/{(Mb2)+(Mb3)} when considering the hydroxyl group-containing amine compound (b1) is preferably 10/90 or more and 30/70 or less. From the viewpoint of sexuality, it is more preferably 13/87 or more and 28/72 or less.

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.

<Viscosity>
The polyurethane resin-forming composition for a membrane sealant has a mixed viscosity of the allophanate group-containing polyisocyanate prepolymer (A) and the polyol (B) after 60 seconds from the start of mixing. It is preferably 400 mPa·s or more and 2100 mPa·s or less, more preferably 500 mPa·s or more and 1800 mPa·s or less.

The composition for forming a polyurethane resin for a membrane sealing material according to one embodiment of the present invention can form a membrane sealing material in which the amount of low-molecular-weight reaction products of MDI and glycerin eluted is suppressed, and clouding of molded products is suppressed. In addition, it is possible to provide a polyurethane resin-forming composition for a membrane sealing material, which has good rapid curability, low viscosity and excellent castability.

<Membrane sealing material>
A membrane sealant according to one embodiment of the present invention includes a cured product of the polyurethane resin-forming composition for a membrane sealant described above.
The membrane sealing material constitutes the allophanate group-containing polyisocyanate prepolymer (A) under temperature conditions of 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. It can be suitably formed by reacting and curing an isocyanate component and a polyol component constituting the polyol (B). Although the gelling time of the membrane sealant can be shortened by molding it in a high temperature range, molding shrinkage is likely to occur.

<Membrane module>
A membrane module according to an embodiment of the present invention comprises
a main body;
a membrane;
a membrane sealing material that seals a gap between the main body and the membrane;
The membrane sealing material is the membrane sealing material described above.

Next, 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 (main body) 11, and a plurality of hollow fiber membranes (membrane) 13 are filled therein. 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. Film seal members 19 are provided at both ends (left and right ends in FIG. 1) inside the housing 11, respectively. The membrane 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 membrane sealing material 19 is not present inside the hollow fiber membranes 13, the hollow fiber membranes 13 have a second inlet (one end side) and a second flow port provided in a cap member (not shown). A second fluid (gas or liquid) flows in and out through the outlet (on the other end). 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 includes a plurality of hollow fiber membranes 13, and the membrane sealing material 19 seals the gaps at both ends of the membranes. It is not limited at all. For example, it may be a plurality of or singular membranes having various shapes such as flat membranes, spiral membranes, and the like. The membrane sealing material is not limited to being provided at both ends of the membrane. It may be provided on the entire outer edge of the membrane. Furthermore, the membrane sealing material may be provided on a part of the membrane other than the end to seal. 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.

In the membrane module 100, the gaps between the hollow fiber membranes 13 at the ends of the bundle of the plurality of hollow fiber membranes 13 are sealed with the polyurethane resin-forming composition for membrane sealing material described above, and the composition is cured. to form the membrane sealing material described above (the membrane sealing material seals the gaps between the hollow fiber membranes).

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.

EXAMPLES The present invention will be described more specifically with reference to examples and comparative examples below. However, the present invention should not be construed as being limited by these examples. In addition, hereinafter, "%" means "% by mass" unless otherwise specified. In addition, Example 4 shown below is a test example as a reference example that does not belong to the scope of the present invention.

The following ingredients were used in the Examples and Comparative Examples.
[Allophanate group-containing polyisocyanate prepolymer (A)]
· 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 (manufactured by Tosoh Corporation
Millionate NM, isocyanate group content = 33.6%)
· a1-3; carbodiimide modified form of 4,4'-MDI (manufactured by Tosoh Corporation
Millionate MTL-C, isocyanate group content = 28.6%)
· a2-1; Isotridecanol (manufactured by KH Neochem, OHV = 275 mgKOH/g)
· a2-2; oleyl alcohol (manufactured by Shin Nippon Rika Co., Ltd., Likabinol 90B, OHV =
210 mg KOH/g)
[Polyol (B)]
· b1-1; ethylene oxide/propylene oxide of ethylenediamine = 4/6
Mass ratio adduct (ADEKA BM-34, hydroxyl value = 820 mgKOH / g,
Viscosity (25 ° C.) = 7500 mPa s, ethylene oxide amount = 6.84 mmol / g)
· b1-2; N,N,N',N'-tetrakis[2-hydroxypropyl]ethylenediamine (ADEKA EDP-300, hydroxyl value = 760 mgKOH/g,
Viscosity (25 ° C.) = 50000 mPa s, ethylene oxide amount = 0 mmol / g)
· b2-1; castor oil (URIC H-30 manufactured by Ito Oil Co., Ltd., OHV = 160 mgKOH / g,
Viscosity (25°C) = 690 mPa s)
[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 and 2.

[Production Example 1 of Allophanate Group-Containing Polyisocyanate Prepolymer (A)]
Predetermined amounts of a1-1 and a1-2 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 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 3330 mPa·s at 25°C. Table 1 shows the properties (NCO content, MDI monomer amount, viscosity). A method for measuring properties will be described later.

[Production Examples 2 and 3 of prepolymer (A)]
Prepolymers A-2 to A-5 were synthesized in the same manner as in Production Example 1 except that a1 and a2 were changed to the compositions shown in Table 1. Table 1 shows its properties.

[Preparation example of polyol (B)]
Polyol component B-1 was prepared by mixing 14 parts by mass of polyol (b1-1) and 86 parts by mass of polyol (b2-1). The viscosity at 25° C. was 940 mPa·s, and the hydroxyl value was 252 mgKOH/g.
Polyol component B-2 was prepared by mixing 10 parts by mass of polyol (b1-1), 7 parts by mass of polyol (b1-2) and 83 parts by mass of polyol (b2-1). The viscosity at 25° C. was 1030 mPa·s and the hydroxyl value was 268 mgKOH/g.
Polyol component B-3 was prepared by mixing 9 parts by mass of polyol (b1-1), 9 parts by mass of polyol (b1-2) and 82 parts by mass of polyol (b2-1). The viscosity at 25° C. was 1140 mPa·s and the hydroxyl value was 273 mgKOH/g.
Polyol component B-4 was prepared by mixing 5 parts by mass of polyol (b1-1), 17 parts by mass of polyol (b1-2) and 78 parts by mass of polyol (b2-1). The viscosity at 25° C. was 1240 mPa·s and the hydroxyl value was 295 mgKOH/g.
Polyol component B-5 was prepared by mixing 24 parts by mass of polyol (b1-2) and 76 parts by mass of polyol (b2-1). The viscosity at 25° C. was 1300 mPa·s and the hydroxyl value was 304 mgKOH/g.

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

[Measurement of NCO content]
In prepolymers A-1 to A-5 shown in Table 1, the NCO content was determined according to JIS K1603-1:2007.

[MDI Monomer Content Measurement]
In prepolymers A-1 to A-5 shown in Table 1, the MDI monomer content (% by mass) was determined 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 230 indicating the monomer of MDI was obtained from the chart obtained by detecting the difference in refractive index based on the same calibration curve.

[Preparation of sample for low-molecular-weight dissolution test]
(Examples 1 to 6, Comparative Examples 1 to 6)
The main agents (A-1) to (A-5) and the curing agents (B-1) to (B-5) are combined as shown in Table 3, the liquid temperature is 45 ° C., the isocyanate group / active hydrogen group = 1.00 ( molar ratio), and the mixed liquid containing the main agent and the curing agent was stirred for 15 seconds so that the total mass was 30 g. Further, 10 g of glycerin was added (assuming glycerin contained in the hollow fibers) and stirred for 15 seconds to obtain a cured polyurethane resin. This resin cured product was allowed to stand in a constant temperature bath under the primary curing conditions of 50° C. for 10 minutes and the secondary curing conditions of 45° C. for 2 days.

[Low-molecular weight extraction test]
The low-molecular-weight extractables values of the resin cured products obtained in Examples 1 to 6 and Comparative Examples 1 to 6 were measured by the following method.
First, 20 g of each of the low-molecular extractables value measurement samples obtained in Examples and Comparative Examples was cut into a fan shape, weighed, immersed in 100 ml of purified water preheated to 40°C, and heated at 40°C for 2 hours. After standing for hours, low-molecular-weight eluates were extracted into purified water. Next, the obtained extract was decanted, 10 ml was put in a 50 ml volumetric flask, and the liquid was adjusted to 50 ml with purified water. One-tenth of the maximum absorbance at 240-245 nm was taken as the low-molecular-weight effluent value. Preferably, the low molecular extractables value is less than 0.07, more preferably less than 0.065.

[Mixed viscosity/pot life test]
In Examples 1 to 6 and Comparative Examples 1 to 6, the mixed viscosity and pot life when obtaining cured resin products were determined by the following methods.
Weigh and mix the main agent and curing agent, which have been temperature-adjusted to 45°C in advance, so that the isocyanate group/active hydrogen group = 1.00 (molar ratio) to make a total of 50g, and measure with a rotational viscometer in an atmosphere of 25°C. (Type B, No. 4 rotor) was used to measure the viscosity of the mixture. The viscosity 60 seconds after the start of mixing of the main agent and the curing agent was defined as the mixed viscosity, and the time until the viscosity of the mixture reached 50000 mPa·s was defined as the pot life (seconds). If the mixed viscosity was 1800 mPa·s or less and the pot life was 300 seconds or less, it was judged that the rapid curing property was good.

[Hardness measurement test]
The hardness of the resin cured products obtained in Examples 1-6 and Comparative Examples 1-6 was measured by the following method.
For the measurement samples obtained in each example and comparative example, the JIS-D hardness at the moment of measurement and 10 seconds after the moment of measurement was measured under a temperature condition of 25 ° C. by a method according to the method described in JIS-K7312. did.

[Appearance evaluation]
Each of the polyurethane resin-forming compositions for membrane seal materials in the combinations shown in Tables 3 and 4 was 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, B was given when even a slight turbidity was observed, and C was given when cloudy.

[Whiteness evaluation]
The whiteness of the cured product used for appearance evaluation was measured. Tables 3 and 4 show the results. The whiteness was measured according to JIS-P8123. The whiteness is preferably 7.0 or less, more preferably 5.0 or less.

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

*1 The low-molecular-weight extractables value of Comparative Example 6 could not be evaluated because the reactivity was too fast.
According to one embodiment of the present invention, the elution amount of low-molecular-weight reaction products between MDI and glycerin is suppressed, and it contributes to the formation of a membrane sealing material that suppresses white turbidity of molded products, and has good rapid curing properties. It is possible to provide a polyurethane resin-forming composition for a membrane sealant, which has a low viscosity and excellent castability, and a membrane sealant and a membrane module using the composition. Therefore, the membrane sealing material according to one embodiment of the present invention can be suitably used as a membrane sealing material constituting medical, household, and industrial separation devices.

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

Claims (7)

an allophanate group-containing polyisocyanate prepolymer (A);
A polyurethane resin-forming composition for a membrane sealing material, comprising a polyol (B),
The allophanate group-containing polyisocyanate prepolymer (A) is
diphenylmethane diisocyanate (a1);
containing a reaction product of the active hydrogen-containing compound (a2),
The polyol (B) is
a hydroxyl group-containing amine compound (b1);
At least one polyol (b2) selected from the group consisting of castor oil (b2-1) and castor oil-based polyols (b2-2),
The hydroxyl group-containing amine compound (b1) contains a polyoxyethylene polyoxypropylene aliphatic polyamine,
The content of ethylene oxide derived from the hydroxyl group-containing amine compound (b1) is 0.29 mmol/g or more and 0.5 mmol/g or less with respect to the total amount of the polyurethane resin-forming composition for a membrane seal material. A polyurethane resin-forming composition for sealing materials. 2. The polyurethane for membrane seal materials according to claim 1 , wherein the content of allophanate groups is 0.1 mmol/g or more and 0.7 mmol/g or less with respect to the total amount of the polyurethane resin-forming composition for membrane seal materials. A resin-forming composition. 3. The polyurethane resin-forming composition for membrane sealing materials according to claim 1 , wherein the content of the diphenylmethane diisocyanate monomer is 25% by mass or less relative to the total amount of the polyurethane resin-forming composition for membrane sealing materials. thing. The membrane sealing material according to any one of claims 1 to 3, wherein the content of the polyol (b2) is 1% by mass or more and 45% by mass or less with respect to the total amount of the urethane resin-forming composition. Polyurethane resin-forming composition for use. A membrane sealing material comprising a cured product of the polyurethane resin-forming composition for a membrane sealing material according to any one of claims 1 to 4 . a main body;
a membrane;
a membrane sealing material that seals a gap between the main body and the membrane;
A membrane module, wherein the membrane sealing material is the membrane sealing material according to claim 5 . The membrane is a plurality of hollow fiber membranes,
The membrane sealing material is
a gap between the main body and at least a portion of the plurality of hollow fiber membranes; and
7. The membrane module according to claim 6, wherein at least part of the gaps between the plurality of hollow fiber membranes are sealed.

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