Production of paper and paperboard
AssigneeBetzDearborn Inc.
InventorsLawrence Lu Kuo, Roger Yiming Leung, Steven R. Prescott, Thord Hassler
Life of this patent
Estimating the term…
Abstract
A drainage/retention aid comprising a combination of a) microparticles; and b) a vinylamine copolymer having the general structure: wherein m is from 1-99 mol %, n is from 0 to 50 mol % and o is from 1 to 99 mol %; A is selected from the group consisting of one or more repeating units having the following general structures: and salts thereof wherein p, q and r are mol percentages from 1 to 99, each R1 is independently H or CH3, and X is —CN, —COOR2, —CONR3R4, —OR5, —OCOR6, and mixtures thereof; wherein R2, R3, R4, R5, R6 are independently selected from H or C1 to C4 alkyl; and wherein the vinylamine copolymer has a charge density in a range of from 2 to 24 mEq/g.
Claims13
A method of preparing paper or paper board from an aqueous pulp suspension comprising adding to the pulp suspension a drainage/retention aid comprising:
- a) microparticles;
- and
- b) a vinylamine copolymer having the general formula
- wherein m is from 1 to 99 mol %, n is from 0 to 50 mol % and o is from 1 to 99 mol %;
- A is selected from the group consisting of one or more repeating units having the following general structures:
- and salts thereof wherein p, q and r are mol percentages from 1 to 99, each R1 is independently H or CH3, and
- and mixtures thereof, wherein R2, R3, R4, R5, R6 are independently selected from H or C, to C4 alkyl;
- and wherein the vinylamine copolymer has a charge density in a range of from 2 to 24 mEq/g.
A paper or paperboard product containing a drainage/retention aid comprising:
- a) microparticles;
- and
- b) a vinylamine copolymer having the general structure:
- wherein m is from 1-99 mol %, n is from 0 to 50 mol % and o is from 1 to 99 mol %;
- A is selected from the group consisting of one or more repeating units having the following general structures:
- and salts thereof wherein p, q and r are mol percentages from 1 to 99, each R1 is independently H or CH3, and
- X is —CN, —COOR2, —CONR3R4, —OR5, —OCOR6,
- and mixtures thereof;
- wherein R2, R3, R4, R5, R6 are independently selected from H or C1 to C4 alkyl;
- and wherein the vinylamine copolymer has a charge density in a range of from 2 to 24 mEq/g.
Dependencies are inferred from the claim text.