Process for the preparation of naphthalenesulfonic acid/formaldehyde condensates having a low free formaldehyde content
US5101007A · kind A · utility
1Cited by
5References
5Claims
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Key dates
| Filing date | Feb 8, 1991 |
| Grant date | Mar 31, 1992 |
| Priority date | — |
| Expiry date | Feb 8, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G16/0237
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Process for the preparation of naphthalenesulfonic acid/formaldehyde condensates having a low content of free formaldehyde, in which the condensation products of naphthalenesulfonic acid and formaldehyde obtained after the condensation are brought to a pH of greater than 11.5 at a temperature of not less than 80.degree. C. immediately after the condensation, and are kept under these conditions until the desired formaldehyde content is reached. The resins are preferably used as plasticizers for building materials, for example as concrete plasticizers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.