US5626718A — Use of polymers in the recycled fiber washing/dei…

Claim 1

Independent Claim 66 words

In the deinking of wastepaper in which ink particles are removed from an aqueous slurry of recycled fibers, followed by a washing and thickening step wherein said slurry is treated to further remove ink particles from said recycled fibers, the improvement comprising adding to the slurry an effective amount of cationic polyacrylamide polymer to increase the retention of recycled fibers in said washing and thickening step.

Claim 2

Dependent Claim 66 words

In the deinking of wastepaper in which ink particles are removed from an aqueous slurry of recycled fibers, followed by a washing and thickening step wherein said slurry is treated to further remove ink particles from said recycled fibers, the improvement comprising adding to the slurry an effective amount of cationic polyacrylamide polymer to increase the retention of recycled fibers in said washing and thickening step.

Claim 3

Dependent Claim 29 words

The method as recited in claim 1 wherein from about 0.025 to 25 pounds of active polymer per ton of furnish solids is added to the aqueous papermaking system.

Claim 4

Dependent Claim 17 words

The method as recited in claim 1 wherein the cationic polyacrylamide polymer is a cationic (meth)acrylamide copolymer.

Claim 5

Dependent Claim 68 words

The method as recited in claim 3 wherein the cationic (meth)acrylamide copolymer comprises as a substituent a monomer: ##STR3## wherein R 1 =H or CH 3 ; A=--NH or --O--; x=0-8; R 2 , R 3 , R 4 are each independently H, CH 3 , C 2 -C 8 alkyl, benzyl or C 2 -C 8 alkyl benzyl; and X=Cl, F, Br, I or SO 4 .

Claim 6

Dependent Claim 49 words

The method as recited in claim 3 wherein the cationic (meth)acrylamide copolymer comprises as a substituent a monomer: ##STR4## wherein x=0-8; R 1 =H, CH 3 , C 2 -C 8 alkyl, benzyl or C 2 -C 8 alkyl benzyl; and X=Cl, F, Br, I or SO 4 .

Claim 7

Dependent Claim 20 words

The method as recited in claim 3 wherein said washing and thickening step is performed on a double nip thickener.

Claim 8

Dependent Claim 22 words

The method as recited in claim 1 wherein said cationic polyacrylamide polymer has a molecular weight of from about 3,000,000 to 30,000,000.

Claim 9

Independent Claim 23 words

The method as recited in claim I wherein said cationic polyacrylamide polymer has a percent mole charge of from about 1 to 80%.

Claim 10

Dependent Claim 18 words

The method as recited in claim 1 wherein said cationic polyacrylamide polymer is a 2-acryloyloxyethyltrimethyl ammonium chloride/acrylamide copolymer.

Claim 11

Dependent Claim 75 words

In the manufacture of recycled fibers which includes (1) the repulping of recovered paper, followed by (2) the removal of printing inks from fibers, followed by (3) the treatment of the fibers through a double nip thickener in order to further remove contaminants, and retain furnish solids, the improvement comprising adding to said slurry an effective amount of a cationic polyacrylamide polymer to increase the retention of said furnish solids on said double nip thickener.

Claim 12

Dependent Claim 75 words

In the manufacture of recycled fibers which includes (1) the repulping of recovered paper, followed by (2) the removal of printing inks from fibers, followed by (3) the treatment of the fibers through a double nip thickener in order to further remove contaminants, and retain furnish solids, the improvement comprising adding to said slurry an effective amount of a cationic polyacrylamide polymer to increase the retention of said furnish solids on said double nip thickener.

Claim 13

Dependent Claim 29 words

The method as recited in claim 10 wherein from about 0.025 to 25 pounds of active polymer per ton of furnish solids is added to the aqueous papermaking system.

Claim 14

Dependent Claim 18 words

The method as recited in claim 10 wherein the cationic polyacrylamide polymer is a cationic (meth) acrylamide copolymer.

Claim 15

Dependent Claim 69 words

The method as recited in claim 12 wherein the cationic (meth) acrylamide copolymer comprises as a substituent a monomer: ##STR5## wherein R 1 =H or CH 3 ; A=--NH or --O--; x=0-8; R 2 , R 3 , R 4 are each independently H, CH 3 , C 2 -C 8 alkyl, benzyl or C 2 -C 8 alkyl benzyl; and X=Cl, F, Br, I or SO 4 .

Claim 16

Dependent Claim 48 words

The method as recited in claim 12 wherein the cationic (meth) acrylamide copolymer comprises as a substituent a monomer: ##STR6## wherein x=1-8; R 1 =H, CH 3 , C 2 -C 8 alkyl, benzyl or C 2 -C 8 alkyl benzyl; and X=Cl,F,Br, I or SO 4 .

Claim 17

Dependent Claim 22 words

The method as recited in claim 10 wherein said cationic polyacrylamide polymer has a molecular weight of from about 3,000,000 to 30,000,000.

Claim 18

Dependent Claim 23 words

The method as recited in claim 10 wherein said cationic polyacrylamide polymer has a percent mole charge of from about 1 to 80%.

Claim 19

Dependent Claim 18 words

The method as recited in claim 10 wherein said cationic polyacrylamide polymer is a 2-acryloyloxyethyltrimethyl ammonium chloride/acrylamide copolymer.

Claim 20

Dependent Claim 68 words

In the deinking of wastepaper in which ink particles are removed from an aqueous slurry of recycled fibers followed by a highspeed washing and thickening step wherein said slurry is treated to further remove ink particles from said recycled fibers, the improvement comprising adding to said slurry an effective amount of cationic polyacrylamide to increase the retention of fumish solids in said high speed washing and thickening step.

Claim 21

Dependent Claim 68 words

In the deinking of wastepaper in which ink particles are removed from an aqueous slurry of recycled fibers followed by a highspeed washing and thickening step wherein said slurry is treated to further remove ink particles from said recycled fibers, the improvement comprising adding to said slurry an effective amount of cationic polyacrylamide to increase the retention of fumish solids in said high speed washing and thickening step.

Claim 22

Independent Claim 143 words

A method of treating a pulp slurry containinq contaminant solid particles and fiber solids in a washing/thickening device of the type having a rotating roller and a wire in close proximity to said roller, said roller and said wire in combination, defining a nip interface therebetween, said method comprising: (1) treating said pulp slurry by adding a cationic polyacrylamide polymer thereto in an amount from about 0.025-25 pounds of said polymer per ton solids in said pulp slurry; (2) feeding said pulp slurry to said nip; and (3) forcing water and at least some of said contaminant solid particles from said pulp slurry through said wire along said nip interface to separate at least some of said contaminants from said slurry, whereby the amount of fiber solids remaining with said pulp after said step (3) is increased in comparison to untreated pulp slurries.

Claim 23

Independent Claim 143 words

A method of treating a pulp slurry containinq contaminant solid particles and fiber solids in a washing/thickening device of the type having a rotating roller and a wire in close proximity to said roller, said roller and said wire in combination, defining a nip interface therebetween, said method comprising: (1) treating said pulp slurry by adding a cationic polyacrylamide polymer thereto in an amount from about 0.025-25 pounds of said polymer per ton solids in said pulp slurry; (2) feeding said pulp slurry to said nip; and (3) forcing water and at least some of said contaminant solid particles from said pulp slurry through said wire along said nip interface to separate at least some of said contaminants from said slurry, whereby the amount of fiber solids remaining with said pulp after said step (3) is increased in comparison to untreated pulp slurries.

Claim 24

Dependent Claim 18 words

The method as recited in claim 19 wherein the cationic polyacrylamide polymer is a cationic (meth) acrylamide copolymer.

Claim 25

Dependent Claim 66 words

The method as recited in claim 20 wherein the cationic (meth)acrylamide copolymer comprises as a substituent a monomer: ##STR7## wherein R 1 =H or CH 3 ; A=--NH or --O--; x=0-8; R 2 , R 3 , R 4 are each independently H, CH 3 , C 2 -C 8 alkyl, benzyl or C 2 -C 8 alkyl benzyl; and X═Cl,F,Br, I or SO 4 .

Claim 26

Dependent Claim 47 words

The method as recited in claim 20 wherein the cationic (meth)acrylamide copolymer comprises as a substituent a monomer: ##STR8## wherein x=0-8; R 1 =H, CH 3 , C 2 -C 8 alkyl, benzyl or C 2 -C 8 alkyl benzyl; and X=Cl,F,Br, I or SO 4 .

Claim 27

Dependent Claim 22 words

The method as recited in claim 19 wherein said cationic polyacrylamide polymer has a molecular weight of from about 3,000,000 to 30,000,000.

Claim 28

Dependent Claim 23 words

The method as recited in claim 19 wherein said cationic polyacrylamide polymer has a percent mole charge of from about 1 to 80%.

Claim 29

Dependent Claim 18 words

The method as recited in claim 19 wherein said cationic polyacrylamide polymer is a 2-acryloyloxyethyltrimethyl ammonium chloride/acrylamide copolymer.

Claim 30

Independent Claim 109 words

A method for increasing the amount of fibrous solids material retained in a pulp stock containing contaminant solid particles and said fibrous solids material treated in a washer/thickener device having a rotatable roller and a wire trained around a portion of said roller to define a nip location; said method comprising: (1) adding a cationic polyacrylamide polymer to said pulp stock in an amount of about 0.025-25 pounds of said polymer per ton solids in said pulp slurry; (2) feeding said pulp stock to said nip location and subjecting said pulp stock to centrifugal force thereat to express liquid and some of said contaminant solid particles through said wire.

Claim 31

Independent Claim 109 words

A method for increasing the amount of fibrous solids material retained in a pulp stock containing contaminant solid particles and said fibrous solids material treated in a washer/thickener device having a rotatable roller and a wire trained around a portion of said roller to define a nip location; said method comprising: (1) adding a cationic polyacrylamide polymer to said pulp stock in an amount of about 0.025-25 pounds of said polymer per ton solids in said pulp slurry; (2) feeding said pulp stock to said nip location and subjecting said pulp stock to centrifugal force thereat to express liquid and some of said contaminant solid particles through said wire.

Claim 32

Dependent Claim 18 words

The method as recited in claim 26 wherein the cationic polyacrylamide polymer is a cationic (meth) acrylamide copolymer.

Claim 33

Dependent Claim 66 words

The method as recited in claim 27 wherein the cationic (meth)acrylamide copolymer comprises as a substituent a monomer: ##STR9## wherein R 1 =H or CH 3 ; A=--NH or --O--; x=0-8; R 2 , R 3 , R 4 are each independently H, CH 3 , C 2 -C 8 alkyl, benzyl or C 2 -C 8 alkyl benzyl; and X=Cl,F,Br, I or SO 4 .

Claim 34

Dependent Claim 46 words

The method as recited in claim 27 wherein the cationic (meth)acrylamide copolymer comprises as a substituent a monomer: ##STR10## wherein x=0-8;R 1 =H, CH 3 , C 2 -C 8 alkyl, benzyl or C 2 -C 8 alkyl benzyl; and X=Cl,F,Br, I or SO 4 .

Claim 35

Dependent Claim 22 words

The method as recited in claim 26 wherein said cationic polyacrylamide polymer has a molecular weight of from about 3,000,000 to 30,000,000.

Claim 36

Dependent Claim 23 words

The method as recited in claim 26 wherein said cationic polyacrylamide polymer has a percent mole charge of from about 1 to 80%.

Claim 37

Dependent Claim 18 words

The method as recited in claim 26 wherein said cationic polyacrylamide polymer is a 2-acryloyloxyethyltrimethyl ammonium chloride/acrylamide copolymer.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2000-05-05	2000-11-04	2001-05-06	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2004-05-05	2004-11-04	2005-05-06	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2008-05-05	2008-11-04	2009-05-06	$7700.00	Window Closed / Lapsed

Use of polymers in the recycled fiber washing/deinking process

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