Paper making process and starch compositions comprising a crosslinking agent for use in same
First Claim
Patent Images
1. A method for manufacturing paper or paperboard sheet with increased strength, the method comprising the steps of:
- providing a fiber slurry suitable for use in making paper or paperboard;
incorporating a gelatinized starch composition into the fiber slurry, wherein the gelatinized starch composition comprises;
gelatinized starch; and
an aldehyde generating compound capable of forming at least two or more covalent bonds to functional groups present in the starch or fiber when the aldehyde generating compound is heated above an activation temperature;
forming the paper or paperboard sheet;
heating the paper or paperboard sheet at a temperature above the activation temperature of the aldehyde generating compound which is sufficient to dry the paper or paperboard sheet.
1 Assignment
0 Petitions
Accused Products
Abstract
The present invention relates to methods for manufacturing paper or paperboard with improved strength and drainage by introduction into the fiber furnish, prior to sheet formation, an aqueous starch dispersion of a gelatinized, self-retaining starch, and an aldehyde generating compound or a glyoxal releasing compound. The present invention further relates to pre-gelatinized starch compositions comprising an aqueous mixture of a pre-gelatinized starch and an aldehyde generating compound or a glyoxal releasing compound.
-
Citations
41 Claims
-
1. A method for manufacturing paper or paperboard sheet with increased strength, the method comprising the steps of:
-
providing a fiber slurry suitable for use in making paper or paperboard;
incorporating a gelatinized starch composition into the fiber slurry, wherein the gelatinized starch composition comprises;
gelatinized starch; and
an aldehyde generating compound capable of forming at least two or more covalent bonds to functional groups present in the starch or fiber when the aldehyde generating compound is heated above an activation temperature;
forming the paper or paperboard sheet;
heating the paper or paperboard sheet at a temperature above the activation temperature of the aldehyde generating compound which is sufficient to dry the paper or paperboard sheet. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
-
-
28. A gelatinized starch composition for use strengthening paper or paperboard, the composition comprising:
-
a self-retaining gelatinized starch;
at least one aldehyde blocking compound capable of blocking aldehyde residues; and
an aldehyde generating compound according to the Formula I;
wherein A is an optionally substituted methylene group, an optionally substituted C2-4alkylene group, or a single bond;
B is carbonyl, thiocarbonyl, or an optionally substituted 1,2-ethylene residue;
X1 and X2 are independently selected from the group consisting of oxygen and. NR3;
R1 and R2 are independently selected from the group consisting of hydrogen, hydroxyl, optionally substituted C1-20alkyl, optionally substituted C1-20alkoxy, optionally substituted urea, optionally substituted thiourea, or R1 and R2, taken in combination, form a N,N′
-divalent urea;
R3 is independently selected at each occurrence of R3 from the group consisting of hydrogen, optionally substituted C1-20alkyl, and blocked glyoxal residues, where the blocked glyoxal residue is a 1-hydroxy-2-(protected aldehyde residue)-ethan-1-yl group;
wherein the aldehyde generating compound according to Formula I thermally degrades to generate at least one equivalent of aldehyde when heated above an activation temperature; and
wherein the aldehyde blocking compound loading is at least 10 molar % of the aldehyde generating compound. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41)
-
Specification