Composite semipermeable membrane and process for producing the same

Claim 2

A composite semipermeable membrane which is obtained by crosslinking, on a porous support, (1) at least one polyhydroxy compound selected from the group consisting of compounds represented by the following general formulas (I), (II), (III) and (IV) HO CH₂-CH₂-O H      (I) wherein ℓ denotes an integer from 1 to 500, wherein m denotes an integer from 1 to 4, wherein n denotes an integer from 2 to 4; R₁ denotes a substituent; and p denotes 0 or a positive integer satisfying p + n ≦ 6, wherein X denotes a simple bond or a divalent linking group; r and q each denotes 1 or 2; R₂ and R₃ each denotes a substituent; and s and t denote 0 or a positive integer satisfying s + r ≦ 5 and t + q ≦ 5, respectively, and (2) an amino compound having at least two secondary amino groups and no primary amino group in the molecule, with (3) a multifunctional compound capable of reacting with the hydroxyl group and a secondary amino group.

Claim 3

A composite semipermeable membrane according to claim 1, wherein the polyhydroxy compound represented by the general formula (I) is at least one member selected from the group consisting of polyethylene glycol (having a molecular weight of about 200 to 20,000), triethylene glycol, and ethylene glycol.

Claim 4

A composite semipermeable membrane according to claim 1, wherein the polyhydroxy compound represented by the general formula (II) is at least one member selected from the group consisting of glycerol, erythritol, xylitol, and sorbitol.

Claim 5

A composite semipermeable membrane according to claim 1, wherein the compound represented by the general formula (III) is at least one member selected from the group consisting of hydroquinone, resorcinol, catechol, pyrogallol, and phloroglucinol.

Claim 6

A composite semipermeable membrane according to claim 1, wherein the compound represented by the general formula (IV) is at least one member selected from the group consisting of 4,4′-dihydroxybiphenyl, 2,2-­bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)ethane, bis(4-hydroxyphenyl)­cyclohexylmethane, bis(4-hydroxyphenyl) sulfone, bis(4-hydroxyphenyl) ketone, bis(4-hydroxyphenyl) sulfide, bis(4-hydroxyphenyl) ether, 3-chloro-4,4′-hydroxybiphenyl, 3,3′-dichloro-4,4′-hydroxybiphenyl, and bis(4-hydroxy-­3,5-dimethylphenyl) ketone.

Claim 7

A composite semipermeable membrane according to claim 1, wherein the amino compound is a compound represented by the general formula (V) R₄NH-Y-NHR₅      (V) wherein Y denotes an aliphatic, alicyclic, or aromatic group of 20 or less carbon atoms; and R₄ and R₅ each denotes an alkyl group of 1 to 3 carbon atoms.

Claim 8

A composite semipermeable membrane according to claim 1, wherein the compound represented by the general formula (V) is N,N′-dimethylethylenediamine, N,N′-­diethylpropanediamine, N,N′-dimethyl-m-phenylenediamine, N,N′-dimethyl-p-phenylenediamine, or N,N′-dimethyl-1,4-­cyclohexylenediamine.

Claim 9

A composite semipermeable membrane according to claim 1, wherein the amino compound is a compound represented by the general formula (VI) wherein Z denotes an alkylene group of 1 to 4 carbon atoms; R₆ and R₇ each denotes an alkyl group of 1 to 3 carbon atoms; and a and b each denotes an integer from 0 to 4.

Claim 10

A composite semipermeable membrane according to claim 8, wherein the compound represented by the general formula (VI) is 1,3-dipiperazylpropane or dipiperazyl­methane.

Claim 11

A composite semipermeable membrane according to claim 1, wherein the amino compound is a compound represented by the general formula (VII) wherein R₈ and R₉ each denotes an alkyl group of 1 to 3 carbon atoms; and d, e, and f each denotes an integer from 0 to 4.

Claim 12

A composite semipermeable membrane according to claim 10, wherein the compound represented by the general formula (VII) is 1,3-di(4-piperidino)propane, 1,2-di(4-piperidino)ethane, 4,4′-bipiperidine, or 3,3′-dimethyl-4,4′-bipiperidine.

Claim 13

A composite semipermeable membrane according to claim 1, wherein the amino compound is a compound represented by the general formula (VIII) wherein R₁₀ denotes an alkyl group of 1 to 3 carbon atoms; g denotes 1 or 2; and i denotes an integer from 0 to 4.

Claim 14

A composite semipermeable membrane according to claim 12, wherein the compound represented by the general formula (VIII) is piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, or homopiperazine.

Claim 15

A composite semipermeable membrane according to claim 1, wherein the multifunctional compound is a compound having at least two functional groups selected from an acid halide group, sulfonyl halide group, N-­haloformyl group, and acid anhydride group.

Claim 16

A composite semipermeable membrane according to claim 14, wherein the multifunctional compound is at least one member selected from the group consisting of isophthalic acid chloride, terephthalic acid chloride, trimesic acid chloride, pyromellitic acid chloride, cyclohexanedicarboxylic acid chloride, piperazine-N,N′-­dicarbonyl chloride, dipiperidylmethane-N,N′-dicarbonyl chloride, pyridine-2,6-dicarboxylic acid chloride, 1-­chlorosulfonylbenzene-3,4-dicarboxylic acid chloride, benzene-m-disulfonic acid chloride, 4-chloroformylphthalic acid anhydride, and pyromellitic acid anhydride.

Claim 17

A composite semipermeable membrane according to claim 14, wherein the multifunctional compound is at least one member selected from the gorup consisting of trimesic acid chloride, isophthalic acid chloride, and terephthalic acid chloride.

Claim 18

A composite semipermeable membrane according to claim 1, wherein the material of the porous support is polysulfone, polyethersulfone, polyacrylonitrile, polyvinyl chloride, cellulose acetate, or cellulose nitrate.

Claim 19

A composite semipermeable membrane according to claim 1, wherein the mixing ratio of the polyhydroxy compound to the amino compound is 100:50 to 100:200 by weight.

Claim 20

A composite semipermeable membrane according to claim 1, wherein the polyhydroxy compound and the amino compound are those dissolved in at least one member selected from the group consisting of methanol, ethanol, propanol, and water.

Claim 21

A composite semipermeable membrane according to claim 1, wherein the concentration of the total of the polyhydroxy compound and the amino compound is 0.2 to 3% by weight.

Claim 22

A composite semipermeable membrane according to claim 1, wherein the polyhydroxy compound and the amino compound are those which have been coated on or made to impregnate a porous support as a mixed solution of both compounds and which, after draining of the solu­tion, have been subjected to drying treatment at 20 to 40°C.

Claim 23

A composite semipermeable membrane according to claim 1, wherein the multifunctional compound is the one which has been dissolved in a hydrocarbon type solvent to a concentration of 0.1 to 5% by weight.

Claim 24

A process for producing a composite semipermeable membrane which comprises coating or impregnating a porous support with a solution containing (1) at least one polyhydroxy compound selected from the group consist­ing of compounds represented by the following general formulas (I), (II), (III) and (IV) HO CH₂-CH₂-O H      (I) wherein ℓ denotes an integer from 1 to 500, wherein m denotes an integer from 0 to 4, wherein n denotes an integer from 2 to 4; R₁ denotes a halogen atom or lower alkyl group; and p denotes 0 or a positive integer satisfying n + p ≦ 6, wherein X denotes a simple bond, a divalent hydrocarbon group, -O-, -CO-. -SO₂-, or -S-; r and q each denotes 1 or 2; R₂ and R₃ each denotes a halogen atom or lower alkyl group; and t and s denote 0 or a positive integer satisfying s + r ≦ 5 and t + q ≦ 5, respectively, and (2) an amino compound having at least two secondary amino groups and no primary amino group in the molecule, and then contacting the resulting system with (3) a multifunctional compound capable of reacting with the hydroxyl group and a secondary amino group, thereby to effect the crosslinking polymerization of the polyhydroxy compound and the amino compound.

Claim 25

A process for producing a composite semipermeable membrane which comprises coating or impregnating a porous support with a solution containing (1) at least one polyhydroxy compound selected from the group consist­ing of compounds represented by the following general formulas (I), (II), (III) and (IV) HO CH₂-CH₂-O H      (I) wherein ℓ denotes an integer from 1 to 500, wherein m denotes an integer from 0 to 4, wherein n denotes an integer from 2 to 4; R₁ denotes a halogen atom or lower alkyl group; and p denotes 0 or a positive integer satisfying n + p ≦ 6, wherein X denotes a simple bond, a divalent hydrocarbon group, -O-, -CO-. -SO₂-, or -S-; r and q each denotes 1 or 2; R₂ and R₃ each denotes a halogen atom or lower alkyl group; and t and s denote 0 or a positive integer satisfying s + r ≦ 5 and t + q ≦ 5, respectively, and (2) an amino compound having at least two secondary amino groups and no primary amino group in the molecule, and then contacting the resulting system with (3) a multifunctional compound capable of reacting with the hydroxyl group and a secondary amino group, thereby to effect the crosslinking polymerization of the polyhydroxy compound and the amino compound.