Radiation induced graft polymerization
First Claim
Patent Images
1. Method of preparing moisture-swellable absorbent material comprising:
- (a) treating a substrate capable of forming graft polymers with an acrylate salt under the influence of high energy ionizing radiation, with an aqueous monomer dispersion of(i) an acrylate salt selected from the group consisting of sodium acrylate, potassium acrylate, lithium acrylate, ammonium acrylate and mixtures thereof, and;
(ii) a water-dispersible cross-linking monomer in amounts from about 2 percent to 10 percent by weight of said acrylate salt, said aqueous dispersion having sufficient acrylate salt and cross-linking monomer to form a reaction product with said substrate in amounts from about 60 percent to 200 percent by weight of the substrate; and
(b) irradiating said treated substrate with high energy ionizing radition having an energy of at least about 150,000 electron volts at a dose rate no greater than 90 megarads per second to provide a dosage from about 0.5 to 25 megarads, to thereby form a graft polymer on the surface of, and on interpenetrating network within, said substrate.
1 Assignment
0 Petitions
Accused Products
Abstract
An absorbent material is prepared by treating a substrate with an aqueous monomer dispersion of an acrylate salt and a cross-linking monomer and thereafter irradiating the treated substrate with high energy ionizing radiation to form a cage matrix of the polymer and monomer substrate. The absorbent material can be swelled with a solution containing a volatile additive to dispense said additive over a period of time.
106 Citations
21 Claims
-
1. Method of preparing moisture-swellable absorbent material comprising:
-
(a) treating a substrate capable of forming graft polymers with an acrylate salt under the influence of high energy ionizing radiation, with an aqueous monomer dispersion of (i) an acrylate salt selected from the group consisting of sodium acrylate, potassium acrylate, lithium acrylate, ammonium acrylate and mixtures thereof, and; (ii) a water-dispersible cross-linking monomer in amounts from about 2 percent to 10 percent by weight of said acrylate salt, said aqueous dispersion having sufficient acrylate salt and cross-linking monomer to form a reaction product with said substrate in amounts from about 60 percent to 200 percent by weight of the substrate; and (b) irradiating said treated substrate with high energy ionizing radition having an energy of at least about 150,000 electron volts at a dose rate no greater than 90 megarads per second to provide a dosage from about 0.5 to 25 megarads, to thereby form a graft polymer on the surface of, and on interpenetrating network within, said substrate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. The moisture-swellable absorbent material formed by the process which comprises:
-
(a) treating a substrate capable of forming graft polymers with an acrylate salt under the influence of high energy ionizing radiation with an aqueous monomer dispersion of (i) an acrylate salt selected from the group consisting of sodium acrylate, potassium acrylate, lithium acrylate, ammonium acrylate and mixtures thereof, and; (ii) a water-dispersible cross-linking monomer in amounts from about 2% to 10% by weight of said acrylate salt in said aqueous dispersion having sufficient acrylate salt and cross-linking monomer to form a reaction product with said substrate in amounts from about 60 percent to 200 percent by weight of substrate, (b) by irradiating said treated substrate with high energy ionizing radiation having an energy of at least about 150,000 electron volts at a dose rate up to about 90 megarads per second to provide a dosage from about 0.5 to 25 megarads to thereby form a graft polymer on the surface and an interpenetrating network within, said substrate. - View Dependent Claims (14, 15, 16)
-
-
17. A method for preparing a swelled article capable of dispensing volatile additives which comprises forming a moisture swellable absorbent material by:
-
(a) treating substrate capable of forming graft polymers with an acrylate salt under the influence of high energy ionizing radiation, with an aqueous monomer dispersion of (i) an acrylate salt selected from the group consisting of sodium acrylate, potassium acrylate, lithium acrylate, ammonium acrylate and mixtures thereof, and; (ii) a water-dispersible cross-linking monomer in amounts from about 2 to 10 percent by weight of said acrylate salt, said aqueous dispersion having sufficient acrylate salt and cross-linking monomer to form a reaction product with said substrate in amounts from about 60 percent to 200 percent by weight of the substrate; (b) irradiating said treated substrate with high energy ionizing radiation having an energy of at least about 150,000 electron volts at a dose rate no greater than about 90 megarads per second to provide a dosage from 0.5 to 25 megarads and thereby form a graft polymer on the surface of, and an interpenetrating network within, said substrate, and (c) treating said swellable material with an aqueous solution or dispersion containing said volatile additive to permit said material to absorb said aqueous solution or dispersion. - View Dependent Claims (18)
-
-
19. A swelled article capable of dispensing predetermined amounts of volatile additive formed by the process which comprises forming a moisture swellable absorbent material by:
-
(a) treating substrate capable of forming graft polymers with an acrylate salt under the influence of high energy ionizing radiation, with an aqueous monomer dispersion of (i) an acrylate salt selected from the group consisting of sodium acrylate, potassium acrylate, lithium acrylate, ammonium acrylate and mixtures thereof, and; (ii) a water-dispersible cross-linking monomer in amounts from about 2 to 10 percent by weight of said acrylate salt, said aqueous dispersion having sufficient acrylate salt and cross-linking monomer to form a reaction product with said substrate in amounts from about 60 percent to 200 percent by weight of the substrate; (b) irradiating said treated substrate with high energy ionizing radiation having an energy of at least about 150,000 electron volts at a dose rate no greater than about 90 megarads per second to provide a dosage from 0.5 to 25 megarads and thereby form a graft polymer on the surface, and in an interpenetrating network within, said substrate, and (c) treating said swellable material with an aqueous solution or dispersion containing said volatile additive to permit said material to absorb said aqueous solution or dispersion. - View Dependent Claims (20, 21)
-
Specification