Process for preparation of improved semipermeable composite membranes
First Claim
1. In a process for producing a semipermeable composite membrane which comprises forming on a microporous substrate a thin layer of polymeric material comprising a polyamino polymer containing at least 1 milliequivalent, per gram of the polymer in the dry state, of active amino groups selected from primary amino groups and secondary amino groups, and thereafter interfacially crosslinking a surface portion of said thin layer with a crosslinking agent comprising a cyclic compound having at least two functional groups (a) selected from the group consisting of carbonyl halide, sulfonyl halide, isocyanate and acid anhydride groups;
- the improvement wherein(1) said polymeric material contains dispersed therein a polyfunctional aliphatic compound having at least two functional groups (b) which are selected from the group consisting of --CH(OH)CH2 X1, --COOA1, --NHCOOA2, ##STR86## and active halomethyl groups, in which X1 and X2 each represent a halogen atom, A1 and A2 each represent a hydrogen atom or an organic radical capable of being split off together with the oxygen atom to which it is bonded, and A3 represents a trivalent or tetravalent saturated aliphatic groups having 2 to 5 carbon atoms, and are substantially incapable of reacting with the primary or secondary amino groups in said polymer at a temperature at which the interfacial crosslinking is carried out, but capable of reacting easily with either the primary or secondary amino groups or both in said polymer at a temperature at least 30°
C. higher than said crosslinking temperature, and(2) the interfacially crosslinked thin layer is heated to a temperature at which said polyfunctional compound reacts with the primary or secondary amino groups or both in said polymer.
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Abstract
In a process for producing a semipermeable composite membrane which comprises forming on a microporous substrate a thin layer of a polymeric material comprising a polyamino polymer containing at least 1 milliequivalent, per gram of the polymer in the dry state, of active amino groups selected from primary amino groups and secondary amino groups, and thereafter interfacially crosslinking a surface portion of said thin layer with a crosslinking agent having at least two functional groups (a) capable of easily reacting with either the primary or secondary amino groups or both in said polymer; the improvement wherein
(1) said polymeric material contains dispersed therein a polyfunctional compound having at least two functional groups (b) substantially incapable of reacting with the primary or secondary amino groups in said polymer at a temperature at which the interfacial crosslinking is carried out, but capable of reacting easily with either the primary or secondary amino groups or both in said polymer at a temperature at least 30° C. higher than said crosslinking temperature, and
(2) the interfacially crosslinked thin layer is heated to a temperature at which said polyfunctional compound reacts with the primary or secondary amino groups or both in said polymer.
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Citations
32 Claims
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1. In a process for producing a semipermeable composite membrane which comprises forming on a microporous substrate a thin layer of polymeric material comprising a polyamino polymer containing at least 1 milliequivalent, per gram of the polymer in the dry state, of active amino groups selected from primary amino groups and secondary amino groups, and thereafter interfacially crosslinking a surface portion of said thin layer with a crosslinking agent comprising a cyclic compound having at least two functional groups (a) selected from the group consisting of carbonyl halide, sulfonyl halide, isocyanate and acid anhydride groups;
- the improvement wherein
(1) said polymeric material contains dispersed therein a polyfunctional aliphatic compound having at least two functional groups (b) which are selected from the group consisting of --CH(OH)CH2 X1, --COOA1, --NHCOOA2, ##STR86## and active halomethyl groups, in which X1 and X2 each represent a halogen atom, A1 and A2 each represent a hydrogen atom or an organic radical capable of being split off together with the oxygen atom to which it is bonded, and A3 represents a trivalent or tetravalent saturated aliphatic groups having 2 to 5 carbon atoms, and are substantially incapable of reacting with the primary or secondary amino groups in said polymer at a temperature at which the interfacial crosslinking is carried out, but capable of reacting easily with either the primary or secondary amino groups or both in said polymer at a temperature at least 30°
C. higher than said crosslinking temperature, and(2) the interfacially crosslinked thin layer is heated to a temperature at which said polyfunctional compound reacts with the primary or secondary amino groups or both in said polymer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32)
- the improvement wherein
Specification