Method and composition for the sizing of paper with a mixture of a polyacid and a polybase
AssigneeSRI International
InventorAsutosh Nigam
Life of this patent
Estimating the term…
Abstract
Compositions and methods are provided for the sizing of paper, to enhance the quality of images printed thereon. The novel sizing compositions contain as a sizing agent a mixture of a polyacid and a polybase. When applied to a paper substrate, such as in an internal or external sizing process, the sizing compositions result in a sized paper substrate that provides high quality printed images when printed with an ink containing a reactive dye having ionizable and/or nucleophilic groups capable of reacting with the sizing agent. Images printed on a paper substrate coated with the sizing compositions of the invention are bleed-resistant, water-resistant (e.g., water-fast), and/or are characterized by an enhanced chroma and hue.
Claims45
In an internal sizing process for manufacturing a sized paper product using a sizing composition, the improvement which comprises using as a sizing agent in the sizing composition a combination of a monomeeric or polymeric polyacid containing two or more carboxylic, sulfonic and/or phosphonic acid groups and a monomeric polybase containing two or more primary, secondary and/or tertiary amine groups.
In an internal sizing process for manufacturing a sized paper product using a sizing composition, the improvement which comprises using as a sizing agent in the sizing composition a combination of a monomeric or polymeric polyacid containing two or more carboxylic, sulfonic and/or phosphonic acid groups and a polymeric polybase comprised of a nitrogenous polymer selected from the group consisting of:
- (a) polymers containing two or more primary amine groups, secondary amine groups and/or tertiary amine groups;
- (b) polyyimines;
- (c) polymers containing two or more three- to five-membered nitrogen-containing heterocycles;
- and (d) combinations thereof.
Dependencies are inferred from the claim text.