Superplasticizers for cementitious compositions
US4441929A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 1982 |
| Grant date | Apr 10, 1984 |
| Priority date | — |
| Expiry date | Aug 24, 2002 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B28/04
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Superplasticizers for cementitious compositions are produced from a raw material mixture of (1) naphthalenesulfonic acid formaldehyde condensate and (2) free sulfuric acid using a 1-step process or a 2-step process. In the 1-step process, the mixture is neutralized with a zinc compound such as zinc oxide to a pH of about 2 to obtain a superplasticizer mixture of the free acid of the naphthalenesulfonic acid formaldehyde condensate and zinc sulfate. In the 2-step process, the mixture is first neutralized with a zinc compound such as zinc oxide to a pH of about 2 and then with a base such as sodium hydroxide to a pH of about 6 to obtain a superplasticizer mixture of the sodium salt of the naphthalenesulfonic acid formaldehyde condensate and zinc sulfate. These superplasticizer mixtures are superior to a low salt content commercial sodium salt of a naphthalenesulfonic acid formaldehyde condensate where sodium sulfate content has been reduced by lime treatment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.