JP2009241034A - Casting polyurethane resin forming composition for sealant of membrane module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a casting polyurethane resin forming composition for a sealant of a membrane module capable of providing the sealant having an excellent heat resistance and excellent oxidation resistance stability for improving the performance of a blood treating unit or a water cleaner. <P>SOLUTION: In the polyurethane resin forming composition consists of an isocyanate component (A) and a polyol component (B), the casting polyurethane resin forming composition for the sealant of the membrane module includes: (A) contains an isocyanate group terminal urethane polymer (a1) having a number-average molecular weight of 4,000 to 10,000 obtained by making a partially dehydrated castor oil react with polyisocyanate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cast polyurethane resin-forming composition for a sealing material of a membrane module. More specifically, the present invention relates to a cast polyurethane resin-forming composition for a sealing material of a membrane module that can provide a sealing material having excellent moldability, heat resistance and oxidation resistance stability.

Conventionally, as a cast polyurethane resin-forming composition used for a sealing material of a membrane module constituting a blood treatment device, a water purifier, etc., those comprising an isocyanate component and a polyol component are known, and in particular, castor oil-based Polyol component consisting of a mixture of an isocyanate component consisting of an isocyanate group-terminated prepolymer obtained by reaction of a polyol and a polyisocyanate, a castor oil-based polyol, and N, N, N ′, N′-tetrakis (2-hydroxypropyl) -ethylenediamine The composition comprising, for example, is widely used (see, for example, Patent Document 1).
However, the conventional polyurethane-based sealing material has a large temperature dependency of mechanical properties, and has a drawback that the mechanical properties deteriorate at a high temperature and the heat resistance is poor. For this reason, for example, when autoclaving a blood treatment device or performing hot water filtration with a water purifier, there is a problem that peeling occurs at the adhesive fixing portion. In order to solve this problem, a method is disclosed in which an isocyanate group-terminated urethane prepolymer obtained from polytetramethylene glycol and diphenylmethane diisocyanate is cured with a curing agent comprising polytetramethylene glycol and castor oil-based polyol (for example, Patent Documents). 2).
However, the sealing material mainly composed of polytetramethylene glycol is excellent in heat resistance, but has a problem that it is inferior in oxidation resistance stability because it contains many ether bonds.

JP-A-53-61695 JP 7-47239 A

From the background described above, a polyurethane-based sealing material that is excellent in heat resistance and oxidation resistance stability is eagerly desired in order to improve the performance of blood treatment devices and water purifiers.
An object of the present invention is to provide a cast polyurethane resin-forming composition for a sealing material of a membrane module that can provide a sealing material having excellent heat resistance and oxidation resistance stability.

As a result of intensive studies to solve the above problems, the present inventor has arrived at the present invention.
That is, the present invention provides a polyurethane resin-forming composition comprising an isocyanate component (A) and a polyol component (B), wherein (A) has a number average molecular weight of 4, which is obtained by reacting partially dehydrated castor oil with polyisocyanate. It is a cast polyurethane resin-forming composition for a sealing material of a membrane module, comprising 000 to 10,000 isocyanate group-terminated urethane prepolymer (a1).

  The sealing material for a membrane module comprising the cast polyurethane resin-forming composition of the present invention has the effect of being excellent in heat resistance and excellent in oxidation resistance stability.

The partially dehydrated castor oil constituting the isocyanate group-terminated urethane prepolymer (a1) in the present invention is obtained by removing a part of the hydroxyl group of castor oil by a dehydration reaction. Usually, sulfuric acid, phosphoric acid, p-toluenesulfonic acid, etc. It is obtained by heating castor oil in the presence of an acidic catalyst.
The hydroxyl value of the partially dehydrated castor oil (unit is mgKOH / g. In the following, only numerical values are shown) is preferably 90 to 150, more preferably 100 to 140, from the viewpoint of mechanical strength and tensile elongation of the sealing material described later. Especially preferably, it is 110-130.

  The polyisocyanate (hereinafter abbreviated as PI) constituting (a1) is a compound having 2 to 3 or more (preferably 2) isocyanate groups in one molecule. Examples of the PI include carbon Number (hereinafter abbreviated as C) (the number of carbon atoms excluding carbon atoms in the isocyanate group, the same applies hereinafter) 2-18 aliphatic PI, C4-15 alicyclic PI, C6-20 aromatic PI, C8 -15 araliphatic PIs, compounds obtained by modifying some or all of the isocyanate groups of these PIs with isocyanurates, burettes, allophanates, uretdiones, uretonimines, carbodiimides, oxazolidones, amides or imides, and mixtures thereof. Can be mentioned.

  Examples of the aliphatic PI include diisocyanate (hereinafter abbreviated as DI) [ethylene DI, tetramethylene DI, hexamethylene DI, dodecamethylene DI, 2,2,4-trimethylhexamethylene DI, lysine DI, 2,6-DI. Methyl caproate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, etc.], triisocyanate (hereinafter abbreviated as TI) [1,6,11-undecane triisocyanate, 2-isocyanatoethyl-2 , 6-diisocyanatohexanoate etc.].

  Examples of the alicyclic PI include DI [isophorone diisocyanate (hereinafter abbreviated as IPDI), dicyclohexylmethane DI (hydrogenated MDI), cyclohexylene DI, methylcyclohexylene DI, bis (2-isocyanatoethyl) -4-cyclohexene- 1,2-dicarboxylate etc.].

  Examples of the aromatic PI include DI [2,4- and / or 2,6-toluene diisocyanate (hereinafter abbreviated as TDI), 4,4′-, 2,4′- and / or 2,2′-diphenylmethane. Diisocyanate (hereinafter abbreviated as MDI), naphthalene diisocyanate (hereinafter abbreviated as NDI) and the like, and TI having 3 or more isocyanate groups [polymethylene polyphenyl polyisocyanate and the like having 3 or more benzene rings].

  Examples of the araliphatic PI include DI [xylylene diisocyanate (hereinafter abbreviated as XDI), α, α, α ′, α′-tetramethylxylylene diisocyanate (hereinafter abbreviated as TMXDI), DI ethylbenzene, etc.]. .

  Of these PIs, aromatic PI and modified products thereof are more preferable, and MDI and modified products thereof are more preferable from the viewpoint of reactivity with the partially dehydrated castor oil and the polyol component (B) described later.

  The number average molecular weight of the isocyanate group-terminated urethane prepolymer (a1) in the present invention is a gel permeation chromatograph obtained by reacting (a1) with excess methanol and blocking the isocyanate group at the end with methanol to inactivate it. It is a number average molecular weight (hereinafter abbreviated as Mn) measured by a graphic (GPC) and calculated from a calibration curve of standard polystyrene. In the present invention, the Mn of the isocyanate group-terminated urethane prepolymer other than (a1) is the same as (a1), and the Mn of the compound other than the isocyanate group-terminated urethane prepolymer is the following (1) Sample preparation. It can measure similarly except not doing.

One example of procedures such as specific measurement conditions is shown below.
(1) Sample preparation 1 g of (a1) is weighed into a 10 ml glass container with a sealed stopper, and 2 g of toluene is added and dissolved. Add 2 g of methanol, shake by hand, homogenize and seal tightly. The mixture is allowed to stand at room temperature (20 to 30 ° C.) for 48 hours, and the isocyanate group in (a1) is blocked with methanol. Remove the airtight stopper and leave it in a circulating dryer at 50 ° C. for 5 hours to dry and remove toluene and methanol to obtain an inactivated sample.

(2) GPC measurement <GPC device>
Device body: HLC-8220GPC [manufactured by Tosoh Corporation]
Data analysis software: GPC-8020 model II [Tosoh Corporation
Made]
GPC column guard column: TSKguardcolumn SuperH-L (4.6mmI.D. × 15cm)
Separation column: TSKgel SuperH2000 (6mmI.D. × 15cm)
+ TSKgel SuperH3000 (6mmI.D. × 15cm)
+ TSKgel SuperH4000 (6mmI.D. × 15cm)
Detector: RI detector <Measurement conditions>
Fluid medium: Tetrahydrofuran (THF)
Flow rate: 0.6 ml / min.
Column temperature: 40 ° C
Sample injection volume: 10 μl
<Reagents>
THF: Antioxidant-free product [Mitsubishi Chemical Corporation]
Standard polystyrene: TSK standard polystyrene A-500, A-1000, A-2500, A-5000, F-1, F-2,
F-4, F-10 [manufactured by Tosoh Corporation]

<Create calibration curve>
0.02 g each of standard polystyrenes with known molecular weight (A-500, A-1000, A-2500, A-5000, F-1, F-2, F-4, F-10) in a 200 ml Erlenmeyer flask with a sealed stopper Weigh and add 100 g of THF to dissolve, and prepare a THF solution of 0.02 wt% of each standard polystyrene. Inject 10 μl of the solution and create a calibration curve of retention time (time from injection to detection) and molecular weight.
<Molecular weight measurement>
10 mg of the inactivated sample prepared in (1) above is weighed into a 20 ml glass tube, added with 4 ml of THF, and shaken to dissolve. The solution is filtered using a syringe filter fitted with a 0.2 μm membrane filter. 1 ml of the filtrate is collected in a GPC measurement vial, set in an autosampler whose injection volume is adjusted to 10 μl, and the data processor is operated and measured.

  Mn of (a1) is 4,000 to 10,000, preferably 5,000 to 8,000. When Mn is less than 4,000, the temperature dependence of mechanical properties is large and the heat resistance becomes insufficient. When Mn exceeds 10,000, the viscosity becomes high and the mixing property with the polyol component (B) and as a sealing material are increased. The permeability (moldability) is deteriorated.

  (A1) is a polyisocyanate and partially dehydrated castor oil, preferably 1.1 / 1 to 1.8 / 1 in terms of equivalent ratio of isocyanate group to OH group (NCO / OH), preferably from the viewpoint of viscosity and heat resistance. Can be obtained by reacting at 1.2 / 1 to 1.7 / 1.

Although it does not specifically limit as a manufacturing method of said (a1), The well-known method of making polyisocyanate and partially dehydrated castor oil react in nitrogen atmosphere in reaction container is mentioned.
The reaction temperature in the prepolymerization reaction is usually 30 to 140 ° C., and preferably 60 to 120 ° C. from the viewpoint of reactivity and prevention of side reactions. The reaction is usually carried out in the absence of a solvent, but if necessary, a solvent inert to an isocyanate group [for example, aromatic hydrocarbons (toluene, xylene, etc.), ketones (methyl ethyl ketone, methyl isobutyl ketone, etc.) and two or more of these These solvents may be removed by distillation later.

  The content of (a1) in the isocyanate component (A) is preferably 20 to 100%, more preferably 30 to 90% from the viewpoint of the heat resistance and viscosity of the sealing material described later based on the weight of (A). is there.

In addition to (a1), the isocyanate component (A) can further contain polyisocyanate (a2) listed as the PI constituting (a1).
The content of (a2) is usually 80% or less based on the weight of (A), preferably 10 to 70%, more preferably 20 to 60% from the viewpoints of viscosity and heat resistance.
In addition, (a2) includes free polyisocyanate that remains unreacted as a result of using an excessive amount during the production of the urethane prepolymer (a3) described later.

  In addition to (a1) and (a2), if necessary, the isocyanate component (A) includes (a2) and a polyol (b1) having two or more active hydrogens in the molecule excluding partially dehydrated castor oil. The isocyanate group-terminated urethane prepolymer (a3) to be formed can be contained.

  (B1) is a polyol having a hydroxyl value of 20 to 1,850 (preferably 40 to 1,400) and a functional group of 2 to 8 (preferably 2 to 4), such as polyether polyol, castor oil fatty acid ester polyol, polyester. A polyol and the low molecular weight polyol mentioned later are mentioned.

Examples of the polyether polyol include low molecular weight polyols (C2-24, such as ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol. (Hereinafter abbreviated as EG, DEG, PG, 1,4-BD, 1,6-HD, NPG, GR, TMP, PE), hydrogenated bisphenol A, hexanetriol, sorbitol, shoelace and two or more of these 1 type or 2 or more types of alkylene oxide (hereinafter abbreviated as AO) [C2-12, for example, ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), butylene oxide, and two or more thereof. Combined use] with Mentioned objects and ring opening polymerization product of AO is, specifically (hereinafter abbreviated as PEG) polyethylene glycol, polypropylene glycol (hereinafter PPG for short), polytetramethylene glycol (hereinafter PTMG hereinafter), and the like.
The Mn of the polyether polyol is preferably 150 to 4,000, more preferably 200 to 2,000.

Examples of the castor oil fatty acid ester polyol include castor oil and castor oil fatty acid ester obtained by transesterification of the above low molecular polyol or polyether polyol with castor oil or esterification reaction with castor oil fatty acid.
The Mn of castor oil fatty acid ester polyol is preferably 300 to 4,000, more preferably 500 to 3,000.

Polyester polyols include polycarboxylic acids [aliphatic saturated or unsaturated polycarboxylic acids (C2-40, such as adipic acid, azelaic acid, dodecanoic acid, maleic acid, fumaric acid, itaconic acid, dimerized linoleic acid), aromatic A linear or branched polyester polyol formed from a polycarboxylic acid (C8-15, such as phthalic acid, isophthalic acid, etc.) and a polyol (the aforementioned low molecular polyol and / or polyether polyol); a polylactone polyol [ For example, one or more of the low molecular polyols (2 to 3 valences) is used as an initiator, and (substituted) caprolactone (C6-10, for example, ε-caprolactone, α-methyl-ε-caprolactone, ε-methyl- ε-Caprolactone) as catalyst (organometallic compound, metal chelate compound, fat Polyester polyols (for example, polycaprolactone polyols) subjected to addition polymerization in the presence of a fatty acid metal acylate, etc.]; AO (EO, PO, etc.) is subjected to addition polymerization to a polyester having a carboxyl group and / or an OH group at the terminal. Polyether ester polyol obtained; polycarbonate polyol and the like can be mentioned.
The Mn of the polyester polyol is preferably 150 to 4,000, more preferably 200 to 2,000.

  Mn of (a3) is preferably 500 to 6,000, more preferably 600 to 3,000 from the viewpoint of heat resistance and low viscosity.

  In the production of (a3), the reaction equivalent ratio (NCO / OH) of polyisocyanate (a2) and polyol (b1) is usually 1.1 / 1 to 50/1, the viscosity of the product and the free isocyanate group content (NCO From the viewpoint of (content), it is preferably 1.5 / 1 to 30/1, particularly preferably 2/1 to 10/1. The manufacturing method of (a3) is the same as in the case of (a1).

  The content of (a3) is usually 30% or less based on the weight of (A).

  Examples of the polyol component (B) in the present invention include the partially dehydrated castor oil, the polyol (b1) constituting (a3), the amine polyol, and a combination of two or more thereof. In the case of using a plurality of polyols in combination as (B), a method in which these polyols and the isocyanate component (A) are mixed and used at the same time, and a part of these polyols are mixed with the isocyanate component (A) to leave the remaining polyol. There are a method in which seeds are additionally mixed, or a method in which these plural kinds of polyols are mixed and then used by mixing with the isocyanate component (A).

  As the amine polyol, an AO adduct of [poly (n = 2 to 6)] alkylene poly (n = 2 to 6) amine (C2 to 20) [C10 or more and Mn 2,000 or less, for example, N, N, N ', N'-tetrakis (2-hydroxypropyl) ethylenediamine, N, N, N', N ', N "-pentakis (2-hydroxypropyl) diethylenetriamine]; N, N-dialkyl (alkyl group is C1-3) (Poly) alkylene (alkylene group is C2-3) AO adduct of polyamine (eg, PO adduct of N, N-dimethylpropylenediamine); AO adduct of N-aminoalkyl (C2-3) imidazole (eg, Japanese Patent Application) No. 10-156664); polyalkanolamines (C4-12, such as diethanolamine, triethanolamine) Down), and the like.

Among the above (B), from the viewpoint of heat resistance, preferred is (B) containing 30 to 100% by weight of a low molecular diol having a hydroxyl value of 500 to 1,850 and / or a low molecular triol.
Low molecular diols and triols having a hydroxyl value of 500 to 1,850 include low molecular polyols constituting the above (a3), such as C2-8 diols (EG, PG, 1,4-BD, 1,6-HD, NPG, etc.) and C3-12 triols (GR, TMP, trimethylolbutane, etc.). Of these, 1,4-BD is particularly preferred.
Moreover, from a viewpoint of handling property and reactivity, a low molecular weight polyol and a partially dehydrated castor oil, a castor oil fatty acid ester polyol, or an amine polyol can be used in combination.
When used in combination, the weight ratio of the low molecular weight polyol to the other polyol is preferably 30/70 to 90/10, more preferably 30/70 to 80/20, from the viewpoint of heat resistance and reactivity.

  The NCO / OH equivalent ratio in the reaction of the isocyanate component (A) and the polyol component (B) in the polyurethane resin-forming composition of the present invention is preferably 0.5 / 1 to 2/1 from the viewpoint of reducing unreacted materials. More preferably, it is 0.7 / 1 to 1.5 / 1, and particularly preferably 0.8 / 1 to 1.2 / 1.

The cast polyurethane resin for the sealing material of the membrane module of the present invention is produced by mixing and reacting the isocyanate component (A) and the polyol component (B) with a static mixer or a mechanical mixer after measuring a predetermined amount at the time of use. be able to.
The time (pot life) until the fluidity disappears after mixing and reacting is usually 3 to 300 minutes, and curing is required for 12 to 240 hours at room temperature (20 to 30 ° C.). Here, the point at which no change is observed in the hardness of the polyurethane resin is defined as complete curing (reaction end point). Although it is not always necessary to completely cure the polyurethane resin, curing is required until the hardness range described later is reached. Moreover, it is also possible to shorten the curing time by increasing the curing temperature (for example, 40 to 60 ° C.).

  The viscosity (viscosity before casting) of the mixed solution (composition) composed of the above (A) and (B) is usually 50 to 20,000 mPa · s, preferably 100 to 10 from the viewpoint of curability and moldability. 000 mPa · s, more preferably 200 to 4,000 mPa · s.

  The hardness (Shore D: instantaneous value) of the polyurethane resin after curing obtained by reacting (A) and (B) is usually 10 to 100, and the mechanical strength and cutability (to be described later, polyurethane) to be provided as a sealing material From the viewpoint of the cutability of the hollow fiber membranes bound with resin, it is preferably 20-80.

  The cast polyurethane resin-forming composition for a sealing material of a membrane module of the present invention is particularly preferably used as a sealing material for a hollow fiber blood treatment device and a hollow fiber water treatment device.

An example of specific usage when the composition of the present invention is applied to a sealing material for a membrane module is shown below.
First, the isocyanate component (A) and the polyol component (B) are individually degassed under reduced pressure (0.1 mmHg × 2 hours). A predetermined amount of (A) and (B) are weighed and mixed with stirring, and then injected into a container in which hollow fibers are set by a centrifugal molding method, and the hollow fibers are fixed to the container. Examples of the centrifugal molding method are described in JP-B-57-58963.
Generally, cellulose, acrylic, polyolefin, polyvinyl alcohol, polyamide, polysulfone and the like are used as the material for the hollow fiber. In general, a container made of polycarbonate, ABS, polystyrene or the like is used as the container. The two-component liquid mixture loses its fluidity 3 to 300 minutes after the injection, and the membrane module can be taken out from the container (molding machine). Next, after curing at room temperature (20 to 30 ° C.) to 60 ° C., the hollow fiber membrane bound with the polyurethane resin is cut with a rotary cutter or the like to obtain an opening at the end of the hollow fiber membrane.

EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to this. In the following, “parts” represents parts by weight, and “%” represents% by weight.
Production Example 1
In a reaction vessel equipped with a stirrer, a thermometer and a nitrogen introduction tube, 4,4′-MDI [trade name “Millionate MT”, manufactured by Nippon Polyurethane Co., Ltd. same as below. ] 286.3 parts and partially dehydrated castor oil [trade name “HS2G-120”, Toyokuni Oil Co., Ltd., hydroxyl value 120] 713.7 parts (NCO / OH equivalent ratio = 1.5), nitrogen stream Under stirring, the mixture was reacted at 70 to 80 ° C. for 4 hours to obtain an isocyanate group-terminated urethane prepolymer (a1-1) having an NCO content of 3.2%. As a result of the GPC measurement under the above conditions (hereinafter the same), Mn of (a1-1) was 6,340.
In another reaction vessel equipped with a stirrer, a thermometer and a nitrogen introduction tube, 500 parts of (a1-1) and 500 parts of 4,4′-MDI were charged and stirred at 70-80 ° C. for 2 hours under a nitrogen stream. To obtain an isocyanate component (A-1). The NCO content of (A-1) was 18.4%, and the viscosity was 5,900 mPa · s / 25 ° C.

Production Example 2
In the production of the urethane prepolymer of Production Example 1, 242.9 parts were substituted for 286.3 parts of 4,4′-MDI, and 757.1 parts (NCO / OH) were substituted for 713.7 parts of partially dehydrated castor oil. An isocyanate group-terminated urethane prepolymer (a1-2) having an NCO content of 1.3% was obtained in the same manner as in Production Example 1 except that the equivalent ratio = 1.2) was used. Mn of (a1-2) was 9,660.
Furthermore, in Production Example 1, an isocyanate component (A-2) was obtained in the same manner as in Production Example 1 except that 500 parts of (a1-2) was used instead of 500 parts of (a1-1). The NCO content of (A-2) was 17.4%, and the viscosity was 9,800 mPa · s / 25 ° C.

Production Example 3
In the production of the urethane prepolymer of Production Example 1, 312.5 parts of the same in place of 286.3 parts of 4,4′-MDI, 687.5 parts of the same in place of 713.7 parts of partially dehydrated castor oil (NCO / OH equivalent) An isocyanate group-terminated urethane prepolymer (a1-3) having an NCO content of 4.3% was obtained in the same manner as in Production Example 1 except that the ratio = 1.7) was used. Mn of (a1-3) was 4,180.
Furthermore, in Production Example 1, an isocyanate component (A-3) was obtained in the same manner as in Production Example 1 except that 500 parts of (a1-3) were used instead of 500 parts of (a1-1). The NCO content of (A-3) was 19.0%, and the viscosity was 2,400 mPa · s / 25 ° C.

Comparative production example 1
In the production of the urethane prepolymer of Production Example 1, 235.2 parts of the same in place of 286.3 parts of 4,4′-MDI, 764.8 parts of the same in place of 713.7 parts of partially dehydrated castor oil (NCO / OH equivalent) An isocyanate group-terminated urethane prepolymer (ratio a1-1) having an NCO content of 1.0% was obtained in the same manner as in Production Example 1 except that the ratio = 1.15) was used. The Mn of (ratio a1-1) was 12,900.
Furthermore, in Production Example 1, an isocyanate component (Ratio A-1) was obtained in the same manner as in Production Example 1 except that 500 parts of (a1-1) was used instead of 500 parts of (a1-1). The NCO content of (Ratio A-1) was 17.3% and the viscosity was 11,000 mPa · s / 25 ° C.

Comparative production example 2
In a reaction vessel similar to Production Example 1, 599.7 parts of 4,4′-MDI and 400.3 parts of partially dehydrated castor oil were charged (NCO / OH equivalent ratio = 5.6 / 1) and stirred under a nitrogen stream. Then, the reaction was carried out at 70 to 80 ° C. for 4 hours to obtain an isocyanate group-terminated urethane prepolymer having an NCO content of 16.5%, which was directly used as an isocyanate component (ratio A-2). Mn of (ratio A-2) excluding the part derived from unreacted 4,4′-MDI was 2,590, and the viscosity was 1,400 mPa · s / 25 ° C.

Comparative production example 3
In a reaction vessel similar to Production Example 1, 666.6 parts of 4,4′-MDI and PTMG [trade name “PTMG1000”, manufactured by Mitsubishi Chemical Corporation, hydroxyl value 112], 444.4 parts (NCO / OH (Equivalent ratio = 5/1) The reaction was carried out at 70 to 80 ° C. for 4 hours with stirring under a nitrogen stream to obtain an isocyanate group-terminated urethane prepolymer having an NCO content of 18.6%. 3). Mn of (ratio A-3) excluding the part derived from unreacted 4,4′-MDI was 2,760, and the viscosity was 2,900 mPa · s / 25 ° C.

Examples 1-3, Comparative Examples 1-3
The polyurethane resin-forming compositions of Examples 1 to 3 and Comparative Examples 1 to 3 were obtained with the composition shown in Table 1.

The obtained composition was evaluated according to the following performance evaluation method. The results are shown in Table 1.
<Performance evaluation method>
(1) (A) / (B) Mixture Viscosity Each component of the isocyanate component (A) and the polyol component (B) was degassed under reduced pressure (0.1 mmHg × 2 hours) at 25 ° C. A total of 100 parts were weighed with the blending compositions of (A) and (B) in Table 1, and stirred and mixed with a stirrer with a rotating propeller blade (rotation speed: 300 rpm) for 30 seconds. The viscosity (mPa · s) 30 seconds after mixing was measured with a rotary viscometer (B-type viscometer).

(2) Hardness of cured product A stirred mixed solution was obtained in the same manner as (1) above. The mixed solution was centrifuged and defoamed at 3,500 rpm for 30 seconds using a centrifuge [manufactured by Kokusan Co., Ltd., type H103N], and transferred to a 150 ml polypropylene container (65 mm diameter, 70 mm height). After curing for 48 hours in a constant temperature bath at 50 ° C., hardness Shore D at 10 ° C., 25 ° C. and 60 ° C. [10 seconds value (value 10 seconds after starting measurement) [Shore D hardness meter, manufactured by Kobunshi Keiki Co., Ltd.] ] Was measured.

(3) Mechanical property of hardened | cured material It carried out similarly to said (2), and obtained the centrifugal defoaming liquid. The defoamed liquid is placed in a polystyrene container having a length of 74 mm, a width of 104 mm, and a height of 23 mm so as to have a depth of 2 mm. After curing for 48 hours in a thermostatic bath at 50 ° C., JIS K7312 (thermosetting polyurethane elastomer molding) It was punched into No. 3 type dumbbells defined in the Physical Test Method of Articles, and used as test pieces (4 pieces) for tensile tests. Using a tensile tester [manufactured by Shimadzu Corporation], a tensile test was performed at 23 ° C. and a tensile speed of 50 mm / min, and the tensile strength and elongation at break were measured. The test was performed on four test pieces, and the average value of the two intermediate values obtained was used as the measurement value.

(4) Oxidation stability of the cured product Another test piece (4 pieces) having the same dumbbell shape as the above (3) was immersed in a 4,000 ppm sodium hypochlorite aqueous solution at 50 ° C. Take out after 60 days, wash with ion-exchanged water, wipe off the water with absorbent cotton, leave it at 23 ° C for 1 day, compare it with the value in (3) above before testing, Retention was determined.

Mechanical property retention rate (%) = (mechanical strength after test / mechanical strength before test) × 100

(5) Adhesive force A centrifugal defoaming solution was obtained in the same manner as in (2) above. Two polycarbonate standard test plates [length 100 mm, width 25 mm, thickness 2 mm, manufactured by Nippon Test Piece Co., Ltd.] coated with the defoaming liquid are bonded together. At this time, the bonded portion has a length of 12.5 mm and a width of 25 mm, and a coating thickness is set to 0.2 mm using a spacer.
The bonded standard test plate was cured for 48 hours in a thermostatic bath at 50 ° C. to obtain a test piece. The test piece was subjected to a tensile test at 23 ° C. and 60 ° C. using a tensile tester with a thermostatic bath [manufactured by Shimadzu Corporation], and the adhesive strength was measured. The test was performed with five test pieces, and the average value was taken as the measured value.

(6) Resin filling (moldability) of membrane module
A stirred mixture was obtained in the same manner as in (1) above. 120 g of the mixed solution was charged into a polycarbonate cylindrical container for membrane module (inner diameter 40 mm, length 300 mm) charged with 10,000 polysulfone hollow fibers, and molded using a centrifugal molding machine. Twenty minutes after molding, the molded product in a polycarbonate cylindrical container was taken out from the molding machine and cured at 50 ° C. for 48 hours to obtain a test membrane module. 30 membrane modules for the test were prepared, 15 were used for the resin filling test of the membrane module, and the remaining 15 were used for the thermal cycle test of the membrane module.
The portion where the hollow fibers were bound with the polyurethane resin was sliced into three layers of about 3 mm perpendicular to the arrangement direction of the hollow fibers with a cutter, and the presence or absence of unfilled portions was observed in each layer. This test was performed using 15 test membrane modules. The resin filling property of the membrane module was evaluated according to the following criteria.

○ All 15 pieces have no unfilled parts △ 1-5 pieces have unfilled defective parts × 6-15 pieces have unfilled defective parts

(7) Thermal cycle test of membrane module The module prepared in (6) above is allowed to stand in a constant temperature bath at 0 ° C. for 24 hours and then in a constant temperature bath at 100 ° C. for 24 hours. After repeating the cooling and heating for 5 cycles, it was observed whether there was any peeling between the polycarbonate cylindrical container and the sealing material. This test was performed using 15 test membrane modules.

○ None of 15 strips △ 1-5 stripped × 6-15 stripped

  From the results in Table 1, it can be seen that the polyurethane resin-forming compositions of the present invention (Examples 1 to 3) have a low mixed solution viscosity and excellent resin filling properties (moldability) of the membrane module. The polyurethane resin obtained by curing the composition has little temperature change in hardness, has excellent adhesive strength at low temperature as well as high temperature, and mechanical properties suitable for a sealing material, and also has excellent oxidation resistance stability. It can be seen that the membrane module made of the resin also has good thermal cycle test results.

  The cast polyurethane resin-forming composition for a sealing material of a membrane module of the present invention can provide a sealing material for a membrane module excellent in moldability, heat resistance and oxidation resistance stability. It can be widely applied to thread type blood treatment devices and water purifiers, and is extremely useful.

Claims (3)

In the polyurethane resin-forming composition comprising an isocyanate component (A) and a polyol component (B), (A) has a number average molecular weight of 4,000 to 10,000 obtained by reacting partially dehydrated castor oil with polyisocyanate. A cast polyurethane resin-forming composition for a sealing material for a membrane module, comprising an isocyanate group-terminated urethane prepolymer (a1). A cast polyurethane resin for a sealing material of a membrane module, obtained by curing the composition according to claim 1. A sealing material for a membrane module comprising the cast polyurethane resin according to claim 2.