Water-absorbing polymer composition

Claim 2

A polymer composition which is water-absorbent comprising (i) a copolymer comprising (a) recurring units of an α,β -unsaturated monomer bearing groups independently selected from carboxyl groups and groups convertible to carboxyl groups, and (b) recurring units of a copolymerizable monomer; and (ii) a polyether derived from C 2 to C 10 alkylene oxides; wherein at least a portion of the said two groups attached to the recurring α,β -unsaturated monomer units of the copolymer either have hydrogen atoms thereon or are reacted to form hydrogen atoms thereon; and, wherein a least a portion of the oxide groups of the polyether are interacted with at least a portion of the hydrogen atoms such that the copolymer and the polyether are associated through hydrogen bonds.

Claim 3

A polymer composition as claimed in claim 1 in which at least a portion of the hydrogen atoms on the groups attached to the recurring α, β-unsaturated monomer units of the copolymer are modified by reaction with a strong base.

Claim 4

A polymer composition as claimed in claim 1 or claim 2 in which said groups convertible to carboxyl groups are selected from carboxylic acid salt groups, carboxylic acid amide groups, carboxylic acid imide groups, cerboyxlic acid anhydride groups, and carboxylic acid ester groups.

Claim 5

A polymer composition which is water-absorbent upon curing comprising: (i) a copolymer containing (a) from about 25 to about 75 mole percent recurring units of at least one α,β -unsaturated monomer bearing at least one pendant unit selected from carboxylic acid units, carboxylic acid salt units, carboxylic acid anhydride units, carboxylic acid imide units, carboxylic acid amide units and carboxylic acid ester units and (b) from about 75 to about 25 mole percent recurring units of a copolymerizable monomer; and, (ii) a polyether derived from C 2 , to C 10 alkylene oxides, wherein from about 20 to about 65 percent of the total pendant units introduced through the α,β-unsaturated monomer must either be carboxylic acid units or must be converted to carboxylic acid units and from about 35 to about 80 percent of the pendant units must either be carboxylic acid salt units or must be converted to carboxylic acid salt units and wherein at least a portion of the oxide groups on the polyether are interacted with the carboxyl hydrogen atoms on the pendant carboxylic acid units such that the copolymer and the polyether are associated through hydrogen bonds.

Claim 6

A polymer composition which is water-absorbent upon curing comprising: (i) a copolymer containing (a) from about 25 to about 75 mole percent recurring units of at least one α,β -unsaturated monomer bearing at least one pendant unit selected from carboxylic acid units, carboxylic acid salt units, carboxylic acid anhydride units, carboxylic acid imide units, carboxylic acid amide units and carboxylic acid ester units and (b) from about 75 to about 25 mole percent recurring units of a copolymerizable monomer; and, (ii) a polyether derived from C 2 , to C 10 alkylene oxides, wherein from about 20 to about 65 percent of the total pendant units introduced through the α,β-unsaturated monomer must either be carboxylic acid units or must be converted to carboxylic acid units and from about 35 to about 80 percent of the pendant units must either be carboxylic acid salt units or must be converted to carboxylic acid salt units and wherein at least a portion of the oxide groups on the polyether are interacted with the carboxyl hydrogen atoms on the pendant carboxylic acid units such that the copolymer and the polyether are associated through hydrogen bonds.

Claim 7

A polymer composition as claimed in claim 4 in which said copolymer is present in an amount within the range of from about 20 to about 80 weight percent, preferably from about 40 to about 60 weight percent.

Claim 8

A polymer composition as claimed in claim 4, or claim 5 in which said polyether is present in an amount within the range of from about 80 to about 20 weight percent, preferably from about 60 to about 40 weight percent:

Claim 9

A polymer composition as claimed in any one of claims 1 to 6 in which said copolymer is an about equimolar copolymer.

Claim 10

A polymer composition as claimed in any one of claims 1 to 7 in which said copolymerizable monomer is selected from ethylene. propylene, isobutylene, C 1 to C 4 alkyl acrylates, C1 to C 4 alkyl methacrylates, vinyl acetate, methyl vinyl ether and styrenic compounds having the formula: wherein R represents hydrogen or an alkyl group having from 1 to 6 carbon atoms and wherein the benzene ring may be substituted with low molecular weight alkyl or hydroxy groups.

Claim 11

A polymer composition as claimed in any one of claims 1 to 8 in which said copolymer is an isobutylene/maleic anhydride copolymer.

Claim 12

A polymer composition as claimed in any one of claims 1 to 9 in which said polyether derived from C 2 to C 10 alkylene oxides is selected from poly(ethylene oxide), poly(propylene oxide), poly(isobutylene oxide), poly(tetramethylene oxide) and random and block, linear or branched copolymers comprising recurring units of at least two monomers selected from ethylene oxide, propylene oxide, isobutylene oxide and tetrahydrofuran.

Claim 13

A polymer composition as claimed in any one of claims 1 to 10 in which said copolymer and said polyether are further associated through ion-dipole interactions.

Claim 15

A method as claimed in claim 12 including the step of forming the blend into one or more shaped articles after the blend is prepared but before it is fully cured.

Claim 16

A method as claimed in claim 13 in which the blend is formed into fibers, powder or film.

Claim 18

An article of manufacture having excellent water and electrolyte absorption capacity comprising a polymer composition as defined in any one of claims 1 to 11 and a means for supporting said composition for absorption usage.

Claim 19

An article of manufacture as claimed in claim 16 in which said support means is selected from bandages, surgical sponges, dental sponges, catamenial tampons, sanitary napkins, disposable diapers, and pads for absorption of perspiration.

Claim 21

A method as claimed in claim 18 in which said polymer composition is incorporated in fibrous form.