JP6631246B2 - Polyurethane resin forming composition for membrane sealing material, and membrane sealing material for module using hollow or flat membrane fiber separation membrane using the forming composition - Google Patents

Description

  The present invention relates to a polyurethane resin-forming composition for a membrane sealing material and a membrane sealing material for a module using a hollow or flat membrane fiber separation membrane using the composition.

  Modules using hollow fibers or flat membranes as separation membranes are widely used in industrial fields such as water treatment and medical fields such as blood treatment. In particular, the demand for water purifiers, artificial kidneys, artificial lungs and the like has been extremely increased. Generally, a polyurethane resin having excellent flexibility, adhesiveness, and chemical resistance at room temperature is used as a membrane sealing material for adhesively fixing the converged end of a module using a hollow or flat membrane fiber separation membrane. It is widely known for use.

  As such a polyurethane resin, for example, as an isocyanate component, a polyurethane resin obtained by curing an isocyanate group-terminated prepolymer obtained from liquefied diphenylmethane diisocyanate and castor oil or a castor oil derivative polyol with a polyol has been proposed. (For example, see Patent Document 1).

  However, for polyurethane resins used in such applications, particularly when a hollow fiber separation membrane is used as the separation membrane, in order to improve the productivity of the membrane module, an isocyanate group-terminated prepolymer or polyol is used. The demand for lower viscosity is increasing.

  Furthermore, the conventional polyurethane resin used for a membrane sealing material for a membrane module has a problem that it is difficult to balance reactivity, low viscosity, and low-temperature storage stability, and a solution is desired.

JP-A-53-98398

  The present invention has been made in view of the above background, and is a membrane sealing material for fixing a hollow or flat membrane fiber separation membrane, which can provide reactivity, low viscosity, and low-temperature storage stability. To provide a polyurethane resin-forming composition for use.

  The present inventor has conducted intensive studies in order to solve the above series of problems. As a result, in the isocyanate component (A), an isocyanate group-containing compound (a1) represented by the following general formula (1) (hereinafter referred to as (a1) It has been found that the above-mentioned problems can be solved by using a polyurethane resin-forming composition for a film sealing material containing a structure (also referred to as a structure), and the present invention has been completed.

[Wherein R ₁ represents a residue other than the active hydrogen group of the active hydrogen group-containing compound (b1), and X represents an oxygen or sulfur atom. R represents a residue containing an unreacted isocyanate group of the isocyanate group-containing compound (a2), and m represents an integer of 1 or 2. When m is 1, n represents an integer of 1 to 30, and when m is 2, n represents an integer of 1 to 15.]
That is, the present invention includes the following embodiments (1) to (7).

  (1) A polyurethane resin-forming composition for a film sealing material containing an isocyanate component (A) and a polyol component (B), wherein an isocyanate represented by the following general formula (1) is contained in the isocyanate component (A). A polyurethane resin-forming composition for a film sealing material, comprising a group-containing compound (a1).

[Wherein R ₁ represents a residue other than the active hydrogen group of the active hydrogen group-containing compound (b1), and X represents an oxygen or sulfur atom. R represents a residue containing an unreacted isocyanate group of the isocyanate group-containing compound (a2), and m represents an integer of 1 or 2. When m is 1, n represents an integer of 1 to 30, and when m is 2, n represents an integer of 1 to 15.]
(2) The polyurethane resin-forming composition for a film sealing material according to the above (1), wherein the isocyanate component (A) is liquid at 25 ° C.

  (3) The polyurethane resin-forming composition for a film sealing material according to the above (1) or (2), wherein the isocyanate group-containing compound (a2) is an aromatic isocyanate having two or more isocyanate groups. .

  (4) The polyurethane for a film sealing material according to any one of (1) to (3) above, wherein the active hydrogen group-containing compound (b1) is a monool or a diol having 1 to 70 carbon atoms. A resin-forming composition.

  (5) A membrane seal, wherein the isocyanate component (A) and the polyol component (B) in the polyurethane resin composition for a membrane seal material according to any one of the above (1) to (4) are reacted. Production method of polyurethane resin for materials.

  (6) A sealing material comprising a cured product of the polyurethane resin-forming composition according to any one of (1) to (4).

  (7) A membrane module sealed with the sealing material according to (6).

  By using the polyurethane resin-forming composition for a membrane seal of the present invention, it has become possible to improve, in particular, the reactivity, viscosity reduction, and low-temperature storage stability. In addition, the polyurethane resin-forming composition for a membrane sealing material according to the present invention is liquid at normal temperature (for example, 25 ° C.). This excellent effect is extremely suitable for use as a binding material (ie, a sealing material for a membrane module) for a medical or industrial fluid separation device using a desired hollow fiber separation membrane or flat membrane separation membrane. can do.

  Hereinafter, the present invention will be described in more detail.

  The polyurethane resin-forming composition for a film sealing material of the present invention contains an isocyanate component (A) and a polyol component (B). As the isocyanate component (A), an isocyanate group-containing compound (a2) is used. It is characterized by containing an isocyanate group-containing compound (a1) represented by the general formula (1) obtained by reacting a hydrogen group-containing compound (b1) with a catalyst (C).

<Isocyanate component (A)>
In the present invention, the isocyanate component (A) is represented by the general formula (1) obtained by reacting the isocyanate group-containing compound (a2) with the active hydrogen group-containing compound (b1) in the presence of the catalyst (C). Containing the isocyanate group-containing compound (a1).

  The isocyanate group-containing compound (a2) in the present invention is not particularly limited, and any compound containing two or more isocyanate groups in one molecule can be used. Examples of the compound containing two or more isocyanate groups in one molecule include toluene diisocyanate, diphenylmethane diisocyanate (hereinafter referred to as MDI), paraphenylene diisocyanate, metaphenylene diisocyanate, naphthalene-1,5-diisocyanate, and triphenylmethane-4. Aromatic isocyanate such as 4,4 ′, 4 ″ -triisocyanate, polyphenylenepolymethylene polyisocyanate, hexamethylene diisocyanate, 1,10-decane diisocyanate, 1,12-dodecane diisocyanate, cyclobutane-1,3-diisocyanate, cyclohexane 1,3- and 1,4-diisocyanates, isophorone diisocyanate, 2,4- and 2,6-hexahydrotoluylene diisocyanate, f Aliphatic or alicyclic isocyanates such as sahydro-1,3- and -1,4-phenylene diisocyanate, perhydro-2,4'- and -4,4'-diphenylmethane diisocyanate, or one of these series of isocyanates Part isocyanurate-modified, biuret-modified, allophanate-modified, uretdione-modified, uretoimine-modified, carbodiimide-modified, oxazolidone-modified, amide-modified, imide-modified, and the like, and these can be used alone or in combination of two or more. .

  Among these, aromatic isocyanates are preferred from the viewpoint that they are excellent in the working environment at the time of molding and can form a cured resin having good physical properties (for example, mechanical strength such as hardness) required for the sealing material. , MDI are more preferred.

  In the present invention, as the active hydrogen group-containing compound (b1), a compound containing one or more active hydrogen groups in one molecule can be used. Monovalent or divalent ones are preferred from the viewpoints of excellent workability, obtaining suitable properties required for the obtained film sealing material, and excellent productivity of the film sealing material. A compound having three or more valences is not preferred because the viscosity of the obtained isocyanate component (A) becomes high. The active hydrogen group-containing compound (b1) preferably has 1 to 70 carbon atoms, more preferably 3 to 30 carbon atoms.

  Examples of the compound (b1) having a monovalent or divalent active hydrogen group include aliphatic, aromatic, and alicyclic alcohols, diols, and thiols.

  Examples of the aliphatic alcohol include methanol, ethanol, propyl alcohol, butyl alcohol, amyl alcohol, lauryl alcohol, and stearyl alcohol.

  Examples of the aliphatic diol include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, neopentyl glycol, 1,3-butanediol, and 1,4-butanediol. , 1,5-pentanediol, 1,6-hexanediol, 2-butyl-2-ethyl-1,3-propanediol, methylpropanediol, 3-methyl-1,5-pentanediol, and the like.

  Examples of the aromatic alcohol include benzyl alcohol, phenethyl alcohol, hydroxybenzyl alcohol, hydroxyphenethyl alcohol, and methoxyphenyl methanol.

  Examples of the aromatic diol include 1,4-benzenedimethanol and 2,3-naphthalenedimethanol.

  Examples of the alicyclic alcohol include cyclohexanol, methylcyclohexanol, dimethylcyclohexanol and the like.

  Examples of the alicyclic diol include 1,2-cyclopentanediol, 1,3-cyclopentanediol, 3-methyl-1,2-cyclopentanediol, 1,2-cyclohexanediol, 1,3-cyclohexanediol, 1,4-cyclohexanediol, 4,4′-bicyclohexanol, 1,4-cyclohexanedimethanol and the like can be mentioned.

Examples of thiols include tridecyl mercaptopropionate, methoxybutyl mercaptopropionate, octyl mercaptopropionate, 3-mercaptobutyrate derivative, 1,4-bis (mercaptomethyl) benzene, and the like.
Among these, aliphatic alcohols and aliphatic diols are preferable, and 2-propanol, 2-ethylhexanol, and tridecanol are particularly preferable, from the viewpoint of obtaining more preferable physical properties required for the obtained membrane sealing material.

  The monomer isocyanate content in the isocyanate component was determined from the peak area% (hereinafter also referred to as PA%) obtained by GPC measurement. The monomer isocyanate content in the sample to be measured is preferably 10.0 to 70.0 (PA%), more preferably 20.0 to 60.0 (PA%). Most preferably, it exists in the range of 30.0 to 50.0 (PA%) from the viewpoint of excellent properties.

  The isocyanate component content of the isocyanate component is preferably 3 to 30% by mass, more preferably 5 to 28% by mass, and is 10 to 26% by mass from the viewpoint of excellent moldability during the production of the membrane sealing material. Is most preferred.

The presence of the (a1) structure represented by the general formula (1) contained in the isocyanate component (A) was confirmed using ¹³ C-NMR.
(1) Measurement device: ECX400M (manufactured by JEOL Ltd.)
(2) Measurement temperature: 23 ° C
(3) Sample concentration: 0.1 g / ml
(4) Solvent: chloroform-d
(5) Evaluation method: The presence of the (a1) structure was confirmed from the signal (120 ppm, 152 ppm, 156 ppm) derived from the (a1) structure.

  The content of the (a1) structure in the isocyanate component is determined from PA% obtained by GPC measurement, and is preferably 40 to 80 (PA%), more preferably 50 to 70 (PA%) in the sample to be measured.

<Polyol component (B)>
In the present invention, the polyol component (B) is not particularly limited, but any compound having an active hydrogen group can be used. For example, low molecular polyols, polyether polyols, polyester polyols, polylactone polyols, castor oil polyols, polyolefin polyols, and hydroxyl group-containing amine compounds can be used. These can be used alone or in combination of two or more. Among these, castor oil-based polyols are preferred because of their excellent chemical resistance and elution resistance.

  Examples of the low-molecular polyol include dihydric polyols such as ethylene glycol, diethylene glycol, propylene glycol, 1,2-, 1,3- or 1,4-butanediol, 1,5-pentanediol, and 3-methyl-1. , 5-pentanediol, 1,6-hexane glycol, 1,8-octanediol, 1,10-decandiodiol, neopentyl glycol, hydrogenated bisphenol A, etc. Examples include methylolpropane, hexanetriol, pentaerythritol, sorbitol and the like. The molecular weight of the low molecular polyol is preferably from 50 to 200.

  Examples of the polyether-based polyol include an alkylene oxide (alkylene oxide having 2 to 4 carbon atoms, such as ethylene oxide, propylene oxide, and butylene oxide) adduct of the above low-molecular polyol, and a ring-opened polymer of the alkylene oxide. Specific examples thereof include polypropylene glycol, polyethylene glycol, polytetramethylene ether glycol, and a tipped ether that is a copolymer of ethylene oxide and propylene oxide. The molecular weight of the polyether polyol is preferably from 200 to 7000. In addition, it is more preferable that the molecular weight is 500 to 5,000 from the viewpoint of excellent moldability during the production of the membrane sealing material.

  Examples of the polyester-based polyol include polycarboxylic acids (aliphatic saturated or unsaturated polycarboxylic acids such as azelaic acid, dodecanoic acid, maleic acid, fumaric acid, itaconic acid, ricinoleic acid, dimerized linoleic acid, and aromatic polycarboxylic acids) For example, polyols obtained by condensation polymerization of phthalic acid, isophthalic acid, terephthalic acid) and a polyol (at least one selected from the group consisting of the above low-molecular polyols and polyether polyols) are exemplified. The molecular weight of the polyester polyol is preferably from 200 to 5,000. The molecular weight is more preferably from 500 to 3,000 from the viewpoint of excellent moldability during the production of the membrane sealing material.

  As polylactone-based polyols, polymerization initiators such as glycols and triols, ε-caprolactone, α-methyl-ε-caprolactone, ε-methyl-ε-caprolactone and the like, and β-methyl-σ-valerolactone and the like A polyol obtained by addition-polymerizing at least one selected from the group consisting of an organic metal compound, a metal chelate compound, and a fatty acid metal acyl compound in the presence of a catalyst is exemplified. The molecular weight of the polylactone-based polyol is preferably from 200 to 5,000. The molecular weight is more preferably from 500 to 3,000 from the viewpoint of excellent moldability during the production of the membrane sealing material.

  Castor oil-based polyols include linear or branched polyesters obtained by the reaction of castor oil fatty acids with polyols (at least one selected from the group consisting of the above low molecular weight polyols and polyether polyols), for example, diglycerides of castor oil fatty acids And mono-, di- or triesters of castor oil fatty acid and trimethylol alkane, and mono-, di-, or triesters of castor oil fatty acid and polypropylene glycol. The molecular weight of the castor oil-based polyol is preferably from 300 to 4000. The molecular weight is more preferably from 500 to 3,000 from the viewpoint of excellent moldability during the production of the membrane sealing material.

  Examples of the polyolefin polyol include polybutadiene or a polybutadiene polyol in which a hydroxyl group is introduced into a terminal of a copolymer of butadiene and styrene or acrylonitrile.

  Other examples include a polyetherester polyol 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, for example, ethylene oxide or propylene oxide, at the terminal thereof.

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

  Examples of the amino alcohol include N, N, N ′, N′-tetrakis [2-hydroxypropyl] ethylenediamine, and N, N, N ′, N, which are propylene oxide or ethylene oxide adducts of amino compounds such as ethylenediamine. '-Tetrakis [2-hydroxyethyl] ethylenediamine and the like, mono-, di- and triethanolamine, N-methyl-N, N'-diethanolamine and the like can be mentioned. Among these, propylene oxide or an ethylene oxide adduct of an amino compound such as ethylenediamine is preferable, and N, N, N ', N'-tetrakis [2-hydroxypropyl] ethylenediamine is more preferable. Use of N, N, N ', N'-tetrakis [2-hydroxypropyl] ethylenediamine is effective in improving workability at the time of molding, reducing eluted substances, and the like.

  When the hydroxyl-containing amine compound is used, the compounding amount is preferably in the range of 1 to 30% by mass, more preferably 5 to 25% by mass, based on 100% by mass of the polyol component (B). . If the proportion in the polyol (B) is less than 1% by mass, the effect of the hydroxyl group-containing amine compound cannot be obtained, and if it exceeds 30% by mass, the reactivity becomes too high, the workability deteriorates, and the filling property is impaired. In addition, there is a possibility that a problem that the hardness of the obtained sealing material becomes too high may occur.

<Catalyst (C)>
The catalyst (C) includes, for example, any known catalyst that can promote the allophanate-forming reaction between the isocyanate group-containing compound (a2) and the active hydrogen group-containing compound (b1). For example, metal salts, quaternary ammonium salts, and tertiary amines.

  Examples of the metal salt include metal salts such as zinc acetylacetonate (ZnAcAc), stannous octoate, and zinc octoate.

  Examples of the quaternary ammonium salt include tetraalkylammoniums such as N, N, N, N, -tetramethylammonium, N, N, N-trimethyl-N-octylammonium and N- (2-hydroxyethyl) -N, N , N, -trimethylammonium, N- (2-hydroxypropyl) -N, N, N, -trimethylammonium and other hydroxyalkyltrialkylammonium and chloride, bromide, hydroxide, formate, caproate, hexanoate, 2-ethyl It is a compound in which a counter ion such as hexanoate or monoalkyl carbonate is combined.

  As the tertiary amine, N, N, N-benzyldimethylamine, N, N, N-dibenzylmethylamine, N, N, N-cyclohexyldimethylamine, N-methylmorpholine, N, N, N-tribenzyl N, N, N-tripropylamine, N, N, N-tributylamine, N, N, N-tripentylamine or N, N, N-trihexylamine or N, N, Polymethylpolyalkylenepolyamines such as N ′, N′-tetramethylethylenediamine, N, N, N ′, N ′, N ″ -pentamethyldiethylenetriamine and 2- (N, N-dimethylamino) ethanol, 3- ( N, N-dimethylamino) propanol, 2- (N, N-dimethylamino) -1-methylpropanol, {2- (N, N-dimethyla) Roh) ethoxy} ethanol, {2- (N, 3 amino alcohol such as N- diethylamino) ethoxy} ethanol.

  The amount of the catalyst is preferably 1 to 100 ppm, more preferably 10 to 50 ppm, based on the mass of the isocyanate component (A). If it is less than 1 ppm, the reaction may not proceed, and if it exceeds 100 ppm, the reaction may be too fast and the control may be difficult.

<Stopper (D)>
In the present invention, a terminator (D) is used as a terminator for the allophanation reaction. Terminating agents (D) include all known agents that deactivate the allophanation catalyst. For example, phosphoric acid, pyrophosphoric acid, metaphosphoric acid, polyphosphoric acid and other compounds showing phosphoric acidity, phosphoric acid, pyrophosphoric acid, metaphosphoric acid, monoalkyl or dialkyl esters of polyphosphoric acid, halogenated acetic acid such as monochloroacetic acid, benzoyl chloride , Hydrochloric acid, sulfuric acid, sulfate, ion exchange resin, chelating agent and the like. The terminator is preferably added in an amount equal to or more than the mole number of the allophanatization catalyst (C), and more preferably 1.0 to 1.5 times the mole amount.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. However, the present invention is not construed as being limited by these examples.

The following components were used in Examples and Comparative Examples.
<Isocyanate (a11)>
4,4′-MDI, trade name “Millionate MT (manufactured by Tosoh Corporation), isocyanate group content = 33.6 (% by mass)
<Isocyanate (a12)>
Mixture of 2,4′-MDI and 4,4′-MDI, trade name “Millionate NM (manufactured by Tosoh Corporation), isocyanate group content = 33.6 (% by mass)
<Isocyanate (a13)>
Modified carbodiimide of 4,4′-MDI, trade name “Coronate MX (manufactured by Tosoh Corporation), isocyanate group content = 29.1 (% by mass)
<Isocyanate (a14)>
Modified carbodiimide of 4,4′-MDI, trade name “Millionate MTL-C (manufactured by Tosoh Corporation), isocyanate group content = 28.6 (% by mass)
<Polyol (b11)>
2-ethylhexanol, number of functional groups = 1.0, molecular weight = 130
<Polyol (b12)>
Isotridecanol, number of functional groups = 1.0, molecular weight = 200, hydroxyl value = 275 (mgKOH / g)
<Polyol (b13)>
Castor oil, trade name “castor oil LAV (manufactured by Ito Oil Co., Ltd.)”, average number of functional groups = 2.7, hydroxyl value = 160 (mgKOH / g), number average molecular weight: 1000
<Polyol (b14)>
Polypropylene glycol, average number of functional groups = 2, hydroxyl value = 110 (mgKOH / g), number average molecular weight: 1000
<Polyol (b15)>
N, N, N ', N'-tetrakis [2-hydroxypropyl] ethylenediamine, number of functional groups = 4.0, hydroxyl value = 760 (mgKOH / g)
<Catalyst (C)>
Zinc acetylacetone <Stopper (D)>
2-ethylhexyl phosphate (monoester: diester = 1: 1 mol)
[Production Example 1: Production of isocyanate component (A-1)]
The inside of a 2 L four-necked flask equipped with a thermometer, a stirrer, a nitrogen sealed tube, and a cooling tube was purged with nitrogen. 871.9 g of isocyanate (a11) was charged into the flask, and heating and stirring were started. When the temperature reached 70 ° C., 128.1 g of polyol (b11) was added, and the mixture was reacted by stirring and mixing at 90 ° C. for 1 hour under a nitrogen atmosphere to obtain an isocyanate group-terminated prepolymer. The catalyst (C) was added thereto, and the mixture was heated to 90 ° C., the internal solution was sampled, and the reaction was followed while measuring the NCO content. The reaction was stopped by adding a fixed amount to obtain an isocyanate component (A-1). The isocyanate component (A-1) was pale yellow and transparent, and had a viscosity at 25 ° C. of 550 mPa · s.

[Production Examples 2 to 4: Production of isocyanate components (A-2) to (A-4)]
Isocyanate components (A-2) to (A-4) shown in Table 1 were obtained in the same manner as in Production Example 1 except that the composition of the raw materials was changed to the composition shown in Table 1.

[Production Example 5: Production of isocyanate component (A-5)]
The inside of a 2-L four-necked flask equipped with a thermometer, a stirrer, a nitrogen sealed tube, and a cooling tube was purged with nitrogen. 724.2 g of isocyanate (a11) was charged into the flask, and the temperature was increased and stirring was started. When the temperature reached 50 ° C., 275.8 g of the polyol (b13) was added, and the mixture was reacted by stirring and mixing at 70 ° C. for 5 hours under a nitrogen atmosphere to form an isocyanate group-terminated prepolymer (A-5). Obtained. The isocyanate component (A-5) was pale yellow and transparent, had an NCO content of 21.0% and a viscosity at 25 ° C of 480 mPa · s.

[Production Examples 6 to 12: Production of isocyanate components (A-6) to (A-12)]
Isocyanate components (A-6) to (A-12) shown in Table 1 were obtained in the same manner as in Production Example 5 except that the composition of the raw materials was changed to the composition shown in Table 1.

[Preparation Example 1: Preparation of polyol component (B-1)]
80 parts by mass of the polyol (b13) and 20 parts by mass of the polyol (b15) were mixed to prepare a polyol component (B-1).

<Examples 1 to 4, Comparative Examples 1 to 6>
"A-1" to "A-4", "A-6", "A-8" to "A-12" as the isocyanate component, and "B-1" as the polyol component in combination with Table 2 And an isocyanate group / active hydrogen group = 1.00 (equivalent ratio) to obtain a polyurethane resin-forming composition for a membrane sealing material. In addition, about "A-5" and "A-7", since the low-temperature storage stability was bad and turbidity and solid matter were generated, the composition mixed with "B-1" was not used.

<Viscosity measurement>
The viscosities of the above (A-1) to (A-12) at a liquid temperature of 25 ° C were measured using a B-type rotational viscometer.

<Measurement of monomer MDI content and (a1) structure content>
In the above (A-1) to (A-12), the content (PA%) of the monomer MDI and the content (PA%) of the structure (a1) were determined by GPC measurement under the following conditions and method.
〔Measurement condition〕
Measuring device: "HLC-8120 (trade name)" (manufactured by Tosoh Corporation)
(2) Column: A column filled with three kinds of packing materials, TSKgel G3000HXL, TSKgel G2000HXL, and TSKgel G1000HXL (all trade names, manufactured by Tosoh Corporation), is connected in series, and measurement and detection are performed 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: A solution of 0.05 g of the sample in 10 ml of THF [measurement method]
First, a calibration curve was obtained from a chart obtained by detecting the difference in refractive index using polystyrene as a standard substance. Next, for each sample, from the chart obtained by detecting the refractive index difference based on the same calibration curve, PA% of the peak near the peak top molecular weight (number average molecular weight) 230 indicating the monomer MDI, and (a1) Structure The peak PA% near the peak top molecular weight (number average molecular weight) of 3800, 3360, 2600, 2000, 1260, and 700 indicating the above was determined.

<Low temperature storage stability>
The above (A-1) to (A-12) were left for 3 months in an environment of 0 ° C., and the appearance of the sample was confirmed. Light yellow and transparent ones were marked with “○”, and those where turbidity or solid matter was observed were marked with “x”.

<Evaluation of hardness of cured product>
Each of the polyurethane resin-forming compositions for a membrane sealing material according to the combination shown in Table 2 was degassed under reduced pressure (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 released to obtain a cured product. For the obtained cured product, the Shore D hardness at 25 ° C. was measured. Table 2 shows the results. The hardness was measured according to JIS K 7312.

<Evaluation of initial viscosity of mixing>
Regarding the polyurethane resin-forming composition for a membrane sealing material according to the combination shown in Table 2, the main agent and the curing agent were uniformly mixed such that the liquid temperature was 25 ° C. and the isocyanate group / active hydrogen group = 1.00 (equivalent ratio). Then, the viscosity at the stage of obtaining the polyurethane resin-forming composition for a membrane sealing material was measured. Table 2 shows the results.

<Evaluation of reactivity>
Regarding the polyurethane resin-forming composition for a membrane sealing material according to the combination shown in Table 2, the main agent and the curing agent were uniformly mixed such that the liquid temperature was 25 ° C. and the isocyanate group / active hydrogen group = 1.00 (equivalent ratio). (Total of the main agent and the curing agent = 100 g), and then, under a 25 ° C. atmosphere, the increase in viscosity was tracked using a rotational viscometer (B type, No. 4 rotor), and mixing of the main agent and the curing agent was started. From the time point, the time until the viscosity of the composition reached 50,000 mPa · s was defined as the pot life, and the reactivity was evaluated. Table 2 shows the results.

  The isocyanate components (A-1) to (A-4) according to Production Examples 1 to 4 shown in Table 1 above have low viscosity and excellent low-temperature storage stability. On the other hand, the isocyanate components (A-5) and (A-7) according to Production Examples 5 and 7 have low viscosity but are inferior in low-temperature storage stability. Further, the isocyanate components (A-9) to (A-12) according to Production Examples 9 to 12 are excellent in low-temperature storage stability but high in viscosity.

  As shown in Table 2 above, all of the polyurethane resin-forming compositions according to Examples 1 to 4 have a low initial mixing viscosity and a short pot life. On the other hand, the polyurethane resin-forming compositions according to Comparative Examples 1 and 2 have a low initial mixing viscosity, but have a long pot life, so that it takes time to form a membrane module. Further, since the polyurethane resin-forming compositions according to Comparative Examples 3 to 6 all have a high mixing viscosity, they are inferior in the filling property at the time of molding the membrane module, and there is a concern that a filling failure may occur.

  As described above, the cured product (sealant) of the polyurethane resin-forming composition of the present invention has many excellent properties, particularly excellent low-elution properties. Therefore, it can be suitably used as a binding material of a hollow or flat membrane fiber separation membrane in a medical or industrial separation apparatus using a hollow fiber or a flat membrane fiber separation membrane. Specific examples of these medical and industrial separation devices include plasma separation, artificial lung, artificial kidney, artificial liver, and household / industrial water treatment devices.

  Incidentally, the polyurethane resin-forming composition for a film sealing material in the present invention is excellent in various physical properties as attributes, for example, hardness, tensile strength, adhesiveness, etc., so that various industrial sealing materials, for example, electric As a sealant for automobiles, automobiles, buildings, civil engineering, and various cushioning materials, and as a composition for obtaining OA equipment parts such as industrial rolls for papermaking, ironmaking, printing, and paper feed rolls. it can.

Claims (6)

A polyurethane resin-forming composition for a film sealing material comprising an isocyanate component (A) and a polyol component (B), wherein an isocyanate group-containing compound represented by the following general formula (1) is contained in the isocyanate component (A) A polyurethane resin-forming composition for a film sealing material containing (a1).
[Wherein R ₁ represents a residue other than the active hydrogen group of the active hydrogen group-containing compound (b1), and X represents an oxygen or sulfur atom. R represents a residue containing an unreacted isocyanate group of the isocyanate group-containing compound (a2) , and the isocyanate group-containing compound (a2) is an aromatic isocyanate having two or more isocyanate groups. m represents an integer of 1 or 2. When m is 1, n represents an integer of 1 to 30, and when m is 2, n represents an integer of 1 to 15.]   The polyurethane resin-forming composition for a film sealing material according to claim 1, wherein the isocyanate component (A) is liquid at 25 ° C. The polyurethane resin-forming composition for a membrane sealing material according to claim 1 or 2 , wherein the active hydrogen group-containing compound (b1) is a monool or a diol having 1 to 70 carbon atoms. 4. Production of a polyurethane resin for a membrane sealing material, wherein the isocyanate component (A) and the polyol component (B) in the polyurethane resin composition for a membrane sealing material according to any one of claims 1 to 3 are reacted. Method. A sealing material comprising a cured product of the polyurethane resin-forming composition according to claim 1 . A membrane module sealed with the sealing material according to claim 5 .