US5280079A — Absorbent products and their manufacture

Claim 1

Independent Claim 93 words

An extruded, water absorbent, water insoluble polymeric element that has a gel capacity of at least 50 grams deionized water per gram dry polymer and that is in the form of fibre or film, wherein the polymer is a cross linked copolymer of a water soluble blend of ethylenically unsaturated monomers comprising a monomer that provides carboxylic acid groups and a monomer that is a hydroxy alkyl ester of a carboxylic monomer, and in which the cross links are ester linkages formed between the carboxylic acid groups and the hydroxy alkyl ester groups.

Claim 2

Dependent Claim 93 words

An extruded, water absorbent, water insoluble polymeric element that has a gel capacity of at least 50 grams deionized water per gram dry polymer and that is in the form of fibre or film, wherein the polymer is a cross linked copolymer of a water soluble blend of ethylenically unsaturated monomers comprising a monomer that provides carboxylic acid groups and a monomer that is a hydroxy alkyl ester of a carboxylic monomer, and in which the cross links are ester linkages formed between the carboxylic acid groups and the hydroxy alkyl ester groups.

Claim 3

Dependent Claim 26 words

An element according to claim 1 in which the monomer that provides the carboxylic acid groups is selected from acrylic acid and water soluble salts thereof.

Claim 4

Dependent Claim 17 words

An element according to claim 1 in which the hydroxy alkyl esters are of (meth) acrylic acid.

Claim 5

Dependent Claim 46 words

An element according to claim 1 in which the carboxylic acid monomer is present as a mixture of free carboxylic acid and alkali metal salt groups in the ratio 1:1 to 1:10 and the total amount thereof is at least 40% by weight of the monomers.

Claim 6

Dependent Claim 46 words

An element according to claim 4 in which the carboxylic acid is acrylic acid, the hydroxy alkyl esters are of (meth) acrylic acid and in which the monomer blend includes from 10 to 45% by weight of plasticizing monomer selected from C 1-24 alkyl (meth) acrylate.

Claim 7

Dependent Claim 19 words

An element according to claim 1 in which the monomer blend includes 2 to 50% by weight plasticizing monomer.

Claim 8

Dependent Claim 25 words

An element according to claim 6 in which the plasticizing monomer is selected from styrenes, vinyl esters, acrylonitrile and alkyl esters or ethylenically unsaturated acid.

Claim 9

Dependent Claim 32 words

An element according to claim 6 in which the plasticising monomer is selected from C 1-24 alkyl (meth) acrylates in an amount of from 10 to 45% by weight of the monomers.

Claim 10

Dependent Claim 49 words

An element according to claim 1 in which the monomer blend comprises at least 50% by weight carboxylic acid monomer, 0.1 to 15% hydroxy alkyl esters of vinyl carboxylic monomers, and up to 50% plasticising monomer selected from styrenes, vinyl esters, acrylonitrile and alkyl esters of ethylenically unsaturated acids.

Claim 11

Dependent Claim 47 words

An element according to claim 1 in which the blend comprises at least 50% by weight (meth) acrylic acid or water soluble salt thereof, 1 to 10% by weight hydroxy alkyl ester of (meth) acrylic acid and 10 to 45% by weight C 1-24 alkyl (meth) acrylate.

Claim 12

Dependent Claim 21 words

An element according to claim 1 in which the fibre or film is stretched before the formation of the cross linkages.

Claim 13

Dependent Claim 99 words

In a polymeric element formed of a cross linked copolymer of a water soluble blend of ethylenically unsaturated monomers comprising at least 50% by weight of a monomer that provides carboxylic acid groups and a monomer that is a hydroxy alkyl ester of a carboxylic monomer, and in which the cross links are ester linkages formed between the carboxylic acid groups and the hydroxy alkyl ester groups, the improvement in which the element is an extruded water absorbent water insoluble fibre or film that has a gel capacity of at least 50 grams deionised water per gram dry polymer.

Claim 14

Dependent Claim 99 words

In a polymeric element formed of a cross linked copolymer of a water soluble blend of ethylenically unsaturated monomers comprising at least 50% by weight of a monomer that provides carboxylic acid groups and a monomer that is a hydroxy alkyl ester of a carboxylic monomer, and in which the cross links are ester linkages formed between the carboxylic acid groups and the hydroxy alkyl ester groups, the improvement in which the element is an extruded water absorbent water insoluble fibre or film that has a gel capacity of at least 50 grams deionised water per gram dry polymer.

Claim 15

Dependent Claim 85 words

An element according to claim 12 in which the monomer that provides the carboxylic acid groups is a mixture of free acrylic acid and water soluble alkali metal salts thereof in a ratio of 1:1 to 1:10 and the total amount thereof is at least 50% by weight of the monomers, the hydroxy alkyl esters are of (meth) acrylic acid, and in which the monomer blend includes 10 to 45% by weight of the monomers of plasticising monomer selected from C 1-24 alkyl (meth) acrylates.

Claim 16

Dependent Claim 145 words

In a polymeric element formed of a cross linked copolymer of a water soluble blend ethylenically unsaturated monomers comprising a monomer that provides at least 50% by weight carboxylic acid groups and a 0.1 to 15% by weight of a monomer that is a hydroxy alkyl ester of a carboxylic monomer, and in which the cross links are ester linkages formed between the carboxylic acid groups and the hydroxy alkyl ester groups, the improvement in which the element is an extruded water absorbent water insoluble fibre or film that has a gel capacity of at least 50 grams deionised water per gram dry polymer and which has been made by extruding a linear copolymer of the said blend in the form of the fibre or film and then forming the said ester cross linkages between the carboxylic acid groups and the hydoxy alkyl ester groups.

Claim 17

Dependent Claim 145 words

In a polymeric element formed of a cross linked copolymer of a water soluble blend ethylenically unsaturated monomers comprising a monomer that provides at least 50% by weight carboxylic acid groups and a 0.1 to 15% by weight of a monomer that is a hydroxy alkyl ester of a carboxylic monomer, and in which the cross links are ester linkages formed between the carboxylic acid groups and the hydroxy alkyl ester groups, the improvement in which the element is an extruded water absorbent water insoluble fibre or film that has a gel capacity of at least 50 grams deionised water per gram dry polymer and which has been made by extruding a linear copolymer of the said blend in the form of the fibre or film and then forming the said ester cross linkages between the carboxylic acid groups and the hydoxy alkyl ester groups.

Claim 18

Dependent Claim 84 words

An element according to claim 14 in which the monomer that provides the carboxylic acid groups is a mixture of free acrylic acid and water soluble alkali metal salts thereof in a ratio of 1:1 to 1:10 and the total amount thereof is at least 50% by weight of the monomers, the hydroxy alkyl esters are of (meth) acrylic acid, and which the monomer blend includes 10 to 45% by weight of the monomers of plasticising monomer selected from C 1-24 alkyl (meth) acrylates.

Claim 19

Dependent Claim 139 words

An extruded, water absorbent, water insoluble polymeric element that has a gel capacity of at least 50 grams deionised water per gram dry polymer and that is in the form of fibre or film, wherein the polymer is a cross linked copolymer of a water soluble blend of ethylenically unsaturated monomers comprising at least 50% by weight of a monomer that provides carboxylic acid groups and 0.1 to 15% by weight of a hydroxylic monomer that provides hydroxyl groups and that has the formula CHR 1 ═CR 2 --Y--Ma--OH where R 1 is hydrogen or carboxy, R 2 is hydrogen, carboxy or methyl, Y is O, CH 2 O or COO, M is alkyleneoxy and a is at least 5 and in which the cross links are linkages formed between the carboxylic acid groups and the said hydroxyl groups.

Claim 20

Dependent Claim 139 words

An extruded, water absorbent, water insoluble polymeric element that has a gel capacity of at least 50 grams deionised water per gram dry polymer and that is in the form of fibre or film, wherein the polymer is a cross linked copolymer of a water soluble blend of ethylenically unsaturated monomers comprising at least 50% by weight of a monomer that provides carboxylic acid groups and 0.1 to 15% by weight of a hydroxylic monomer that provides hydroxyl groups and that has the formula CHR 1 ═CR 2 --Y--Ma--OH where R 1 is hydrogen or carboxy, R 2 is hydrogen, carboxy or methyl, Y is O, CH 2 O or COO, M is alkyleneoxy and a is at least 5 and in which the cross links are linkages formed between the carboxylic acid groups and the said hydroxyl groups.

Claim 21

Dependent Claim 139 words

In a polymeric element formed of a cross linked copolymer of a water soluble blend of ethylenically unsaturated monomers comprising at least 50% by weight of a monomer that provides carboxylic acid groups and 0.1 to 15% by weight of a hydroxylic monomer that provides hydroxyl groups and that has the formula CHR 1 'CR 2 --Y--Ma--OH where R 1 is hydrogen or carboxy, R 2 is hydrogen, carboxy or methyl, Y is O, CH 2 O or COO, M is alkyleneoxy and a is at least 5, and in which the cross links are linkages formed between the carboxylic acid groups and the said hydroxyl groups, the improvement in which the element is an extruded water absorbent water insoluble fibre or film that has a gel capacity of at least 50 grams deionised water per gram dry polymer.

Claim 22

Dependent Claim 139 words

In a polymeric element formed of a cross linked copolymer of a water soluble blend of ethylenically unsaturated monomers comprising at least 50% by weight of a monomer that provides carboxylic acid groups and 0.1 to 15% by weight of a hydroxylic monomer that provides hydroxyl groups and that has the formula CHR 1 'CR 2 --Y--Ma--OH where R 1 is hydrogen or carboxy, R 2 is hydrogen, carboxy or methyl, Y is O, CH 2 O or COO, M is alkyleneoxy and a is at least 5, and in which the cross links are linkages formed between the carboxylic acid groups and the said hydroxyl groups, the improvement in which the element is an extruded water absorbent water insoluble fibre or film that has a gel capacity of at least 50 grams deionised water per gram dry polymer.

Claim 23

Dependent Claim 188 words

A water absorbent, water insoluble, polymeric element having a gel capacity of at least 50 grams deionised water per gram dry polymer and that has been made by a process comprising providing a solution of a water soluble, substantially linear, polymer that has been made be copolymerisation of a water soluble blend of monoethylenically unsaturated monomers comprising at least 50% by weight carboxylic monomer that provides carboxyl groups and 0.1 to 15% by weight hydroxylic monomer that provides hydroxyl groups and that has the formula CHR 1 'CR 2 --Y--M a --OH where R 1 is hydrogen or carboxy, R 2 is hydrogen, carboxy or methyl, Y is O, CH 2 O or COO, M is alkyleneoxy and a is at least 5, shaping the solution by a shaping step selected from extrusion, coating, impregnation and foaming to shape the linear polymer into the shape of the desired element, and then heating the shaped element to cause the said carboxylic and hydroxylic groups to react in the shaped element to form cross linkages of the formula --Y--M a --OCO-- where Y, M and a are as defined above.

Claim 24

Dependent Claim 188 words

A water absorbent, water insoluble, polymeric element having a gel capacity of at least 50 grams deionised water per gram dry polymer and that has been made by a process comprising providing a solution of a water soluble, substantially linear, polymer that has been made be copolymerisation of a water soluble blend of monoethylenically unsaturated monomers comprising at least 50% by weight carboxylic monomer that provides carboxyl groups and 0.1 to 15% by weight hydroxylic monomer that provides hydroxyl groups and that has the formula CHR 1 'CR 2 --Y--M a --OH where R 1 is hydrogen or carboxy, R 2 is hydrogen, carboxy or methyl, Y is O, CH 2 O or COO, M is alkyleneoxy and a is at least 5, shaping the solution by a shaping step selected from extrusion, coating, impregnation and foaming to shape the linear polymer into the shape of the desired element, and then heating the shaped element to cause the said carboxylic and hydroxylic groups to react in the shaped element to form cross linkages of the formula --Y--M a --OCO-- where Y, M and a are as defined above.

Claim 25

Dependent Claim 32 words

An element according to claim 18 in which the monomer blend contains 10 to 45% by weight plasticising monomer selected from alkyl esters of ethylenically unsaturated acids, acrylonitriles, styrenes, and vinyl esters.

Claim 26

Dependent Claim 34 words

An element according to claim 18 in which R 1 is hydrogen, R 2 is hydrogen or methyl, M is selected from ethyleneoxy, propyleneoxy and butyleneoxy, Y is COO and a is from 5-100.

Claim 27

Dependent Claim 40 words

An element according to claim 20 in which the blend comprises 0.1 to 10% by weight of the hydroxylic monomer, 50 to 89.9% by weight acrylic acid (or water soluble salt thereof) and 10 to 30% by weight methyl acrylate.

Claim 28

Dependent Claim 12 words

An element according to claim 18 in which M a is hexapropyleneoxy.

Claim 29

Dependent Claim 193 words

In a water absorbent, water insoluble, polymeric element having a gel capacity of at least 50 grams deionised water per gram dry polymer and that has been made by a process comprising providing a solution of a water soluble, substantially linear, polymer that has been made by copolymerisation of a water soluble blend of monoethylenically unsaturated monomers comprising at least 505 by weight carboxylic monomer that provides carboxyl groups and 0.1 to 15% by weight hydroxylic monomer that provides hydroxyl groups and that has the formula CHR 1 'CR 2 --Y--M a --H where R 1 is hydrogen or carboxy, R 2 is hydrogen, carboxy or methyl, Y is O, CH 2 O or COO, and M is alkyleneoxy, shaping the solution by a shaping step selected from extrusion, coating, impregnation and foaming to shape the linear polymer into the shape of the desired element, and then heating the shaped element to cause the said carboxylic and hydroxylic groups to react in the shaped element to form cross linkages of the formula --Y--M a --OCO-- where Y, M and a are as defined above, the improvement which comprises a being at least 5.

Claim 30

Dependent Claim 193 words

In a water absorbent, water insoluble, polymeric element having a gel capacity of at least 50 grams deionised water per gram dry polymer and that has been made by a process comprising providing a solution of a water soluble, substantially linear, polymer that has been made by copolymerisation of a water soluble blend of monoethylenically unsaturated monomers comprising at least 505 by weight carboxylic monomer that provides carboxyl groups and 0.1 to 15% by weight hydroxylic monomer that provides hydroxyl groups and that has the formula CHR 1 'CR 2 --Y--M a --H where R 1 is hydrogen or carboxy, R 2 is hydrogen, carboxy or methyl, Y is O, CH 2 O or COO, and M is alkyleneoxy, shaping the solution by a shaping step selected from extrusion, coating, impregnation and foaming to shape the linear polymer into the shape of the desired element, and then heating the shaped element to cause the said carboxylic and hydroxylic groups to react in the shaped element to form cross linkages of the formula --Y--M a --OCO-- where Y, M and a are as defined above, the improvement which comprises a being at least 5.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1997-01-17	1997-07-19	1998-01-18	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2001-01-17	2001-07-19	2002-01-18	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2005-01-17	2005-07-19	2006-01-18	$7700.00	Window Closed / Lapsed

Absorbent products and their manufacture

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