Process for decreasing the hygroscopicity of polycarboxylates
US3987218A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 1974 |
| Grant date | Oct 19, 1976 |
| Priority date | — |
| Expiry date | Jun 11, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2998
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process for decreasing the hygroscopicity of a polycarboxylate, said process comprising preparing a melt of a composition having a melting point of about 40.degree. - 120.degree. C, said composition giving an acid or neutral pH in an aqueous solution or suspension, said composition being less hygroscopic than said polycarboxylate, said composition capable of being free flowing under equilibrium conditions at about 30.degree. C and in an air atmosphere of at least about 40% relative humidity; heating said melt in a mixer to a temperature of up to about 140.degree. C; gradually adding said polycarboxylate as a powder to said melt while mixing said melt; wherein said composition comprises at least about 3 and at most about 40% by weight of the mixture resulting after all polycarboxylate has been added to said melt.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.