EP0257635A2
Expired / Lapsed
EP
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Permeable, porous, polymeric membrane with hydrophilic character, methods for preparing said membranes, and their use
Assignee: Dow Danmark AS
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Filing: 1987-08-26
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Granted: —
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Expires: 2007-08-26
Abstract
Abstract Permeable, porous polymeric membrane with hydrophilic character of the membrane, said character being obtained by treatment with a solution comprising one or more hydrophilic, mono-or polymeric compounds selected among soluble, OH-containing cellulose derivatives, polyvinylalcohols and low molecular weight, polyfunctional, NH-and/or OH-containing compounds, optionally in the presence of a cross-linking agent, a surfactant and a initiator followed by rendering the layer deposited during the treatment insoluble on the membrane surface by means of a catalyst reaction at elevated temperatures in order to fixate the hydrophilic material to the membrane. Furthermore a process for the preparation of these membranes by means of treating a permeable, porous, polymeric membrane of hydrophobic character with the above solution in the presence of a catalyst and optionally in the presence of a cross-linking agent, a surfactant and an initiator, and curing of the coated membrane by means of heating to form an insoluble, hydrophilic surface layer. The membranes are suitable for use in ultra- and microfiltration.
Inventors
- 👤 Flemming Faurby Stengaard
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 10:15
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0088; B01D67/0093; B01D67/00931; B01D67/00933; B01D2323/00; B01D2323/30
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
94 words
Permeable, porous polymeric membrane with hydrophilic character characterised in that the hydrophilic character of the membrane is obtained by treatment with a solution comprising one or more hydrophilic, mono- or polymeric compounds selected among soluble, OH-containing cellulose derivatives, polyvinylalcohols and low molecular weight, polyfunctional, NH- and/or OH-containing compounds, optionally in the presence of a cross-linking agent, a surfactant and an initiator followed by rendering the layer deposited during the treatment insoluble on the membrane surface by means of a catalysed reaction at elevated temperatures in order to fixate the hydrophilic material to the membrane.
Claim 2
Dependent Claim
94 words
Permeable, porous polymeric membrane with hydrophilic character characterised in that the hydrophilic character of the membrane is obtained by treatment with a solution comprising one or more hydrophilic, mono- or polymeric compounds selected among soluble, OH-containing cellulose derivatives, polyvinylalcohols and low molecular weight, polyfunctional, NH- and/or OH-containing compounds, optionally in the presence of a cross-linking agent, a surfactant and an initiator followed by rendering the layer deposited during the treatment insoluble on the membrane surface by means of a catalysed reaction at elevated temperatures in order to fixate the hydrophilic material to the membrane.
Claim 3
Dependent Claim
46 words
Membrane according to claim 1, characterised in that its hydrophilic character is obtained by treatment with a solution comprising one or more soluble cellulose derivatives selected among hydroxyalkylcellulose and other cellulose ethers not completely substituted, preferably among hydroxyethylcellulose, hydroxypropylcellulose, methylcellulose, ethylcellulose, carboxymethylcellulose and methylhydroxyethylcellulose and/or polyvinylalcohols.
Claim 4
Dependent Claim
48 words
Membrane according to claim 1, characterised in that the low molecular weight, polyfunctional compounds are selected among primary and secondary amines, compounds of the general formula where R = -NHR², -OH, -SO₃H or -COOH, and R¹ and R² are independently either H or an alkyl group, and diaminopyridines.
Claim 5
Dependent Claim
58 words
Membrane according to claim 1, characterised in that the cellulose derivative is completely or partially substituted by one or more low molecular weight, polyfunctional compounds selected among primary and secondary amines, compounds of the general formula where R = -NHR², -OH, -SO₃H or COOH, and R¹ and R² are independently either H or an alkyl group, and diaminopyridines.
Claim 6
Dependent Claim
91 words
Process for the preparation of a membrane according to claims 1-4 characterised in that a permeable, porous polymeric membrane with hydrophobic character is treated with a solution comprising one or more hydrophilic, monomeric or polymeric compounds selected among soluble, OH-containing cellulose derivatives, polyvinylalcohols as well as low molecular weight, polyfunctional, NH-and/or OH-containing compounds in the presence of a catalyst and optionally in the presence of a cross-linking agent, a surfactant and an initiator, said coated membrane being subsequently cured by means of heating until an insoluble, hydrophilic surface coat is formed.
Claim 7
Dependent Claim
38 words
Process according to claim 5, characterised in that the curing is performed by passing the membrane through a ventilated oven at a temperature of between 100°C and 175°C, for a suitable periode, e.g. from 3 to 60 min.
Claim 8
Dependent Claim
25 words
Process according to claim 5-6 characterised in that the treatment is performed in the presence of an inorganic base or a inorganic acid as catalyst.
Claim 9
Dependent Claim
18 words
Process according to claim 7 characterised in that sodium hydroxide or concentrated sulphuric acid are used as catalysts.
Claim 10
Dependent Claim
100 words
Process according to claim 5-6 characterised in that a membrane is treated with a solution comprising hydroxyalkylcellulose in the presence of an inorganic base as a catalyst, such as NaOH, possibly a cross-linking agent, such as a compound of the general formula R³-(CHOH-CH₂-X) n , where X is a halogen atom, preferably chlorine, R³ is an alkyl group that may include one or more oxygen or halogen atoms or a direct bond or an ether bond, and n is an integer equal to or larger than 1, such as 1,3-dichloro-2-propanol, as well as optionally a surfactant, such as sodiumdodecyl sulphate.
Claim 11
Dependent Claim
106 words
Process according to claims 5-6 and 9 charac terised in that a PVDF-, CTFE/VF- or a PVDF-CTFE/VF-membrane is treated with a solution comprising hydroxyalkylcellulose in the presence of an inorganic base as catalyst, such as NaOH, optionally a cross-linking agent, such as a compound of the general formula R³-(CHOH-CH₂-X) n , where X is a halogen atom, preferably chlorine, R³ is an alkyl group that may include one or more oxygen or halogen atoms or a direct bond or an ether bond, and n is an integer equal to or larger than 1, such as 1,3-dichloro-2-propanol, as well as optionally a surfactant, such as sodiumdodecyl sulphate.
Claim 12
Dependent Claim
38 words
Process according to claims 9-10 characterised in that the cellulose derivative is completely or partially substituted by one or more low molecular weight, polyfunctional, NH- and/or OH-containing compounds, preferably selected among diaminopyridines, tetraethylene pentamine, aminophenols and sulfanilic acid.
Claim 13
Dependent Claim
94 words
Process according to claims 5-6 characterised in that a membrane is treated with a solution comprising a hydroxyalkylcellulose and/or a polyvinylalcohol in the presence of an inorganic acid, preferably sulphuric acid, as catalyst, optionally a cross-linking agent selected among polyols, such as sugars, e.g. gluconic acid or sorbitol, inositol, pentaerythrite, aromatic hydroxycompounds, e.g. 2,5-dihydroxybenzene sulfonic acid or 4,5 dihydroxy-1,3-benzenedisulfonic acid, polyoxyethylene sorbitane esters, polyfunctional acids, such as polyacrylic acid, polyfunctional esters, such as dimethyltartrate and dithyltartrate, and polyfunc tional, unsaturated compounds, such as triallyl-1,3,5-triazine-2,4,5-trione, as well as a peroxide compound as initiator if required.
Claim 14
Dependent Claim
100 words
Process according to claims 5-6 and 12 characterised in that a polysulfone, a PVDF-, CTFE/VF-or a PVDF-CTFE/VF-membrane is treated with a solution comprising a hydroxyalkylcellulose and/or a polyvinylalcohol in the presence of an inorganic acid, preferably sulphuric acid, as catalyst, optionally a cross-linking agent selected among polyols, such as sugars, e.g. gluconic acid or sorbitol, inositol, pentaerythrite, aromatic hydroxycompounds, e.g. 2,5-dihydroxybenzene sulfonic acid of 4,5 dihydroxy-1,3-benzenedisulfonic acid, polyoxyethylene sorbitane esters, polyfunctional acids, such as polyacrylic acid, polyfunctional esters, such as dimethyltartrate and diethyltartrate, and polyfunctional, unsaturated compounds, such as triallyl-1,3,5-triazine-2,4,6-trione, as well as a peroxide compound as initiator if required.
Claim 15
Dependent Claim
17 words
Use of the permeable, porous, polymeric membranes of claims 1 to 4 for ultrafiltration and microfiltration applications.
References Cited (Backward Citations)
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