Kraft process for the production of wood pulp by adding a copolymer of 1,2-dihydroxy-3-butene antiscalant
US6146495A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 1998 |
| Grant date | Nov 14, 2000 |
| Priority date | — |
| Expiry date | Aug 31, 2018 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C11/106
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
An improved process for inhibiting calcium carbonate scaling in aqueous systems such as that employed in the kraft process for the production of wood pulp. Such an improved process is achieved by the addition to the system of at least one antiscalant comprising at least one monomer unit derived from the group consisting of 1,2-dihydroxy-3-butene, N-(hydroxymethyl) acrylamide, and N-(sulfomethyl) acrylamide, and at least one monomer unit derived from the group consisting of maleic acid, acrylic acid, acrylamide, methacrylic acid, itaconic acid, vinyl sulfonic acid, styrene sulfonic acid, N-tertbutylacrylamide, butoxymethylacrylamide, N,N-dimethylacrylamide, sodium acrylamidomethyl propane sulfonic acid, and salts thereof, with the proviso that said polymers do not contain the monomer unit --(CH.sub.2 --CH.dbd.CH--CH.sub.2 --O)--.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.