Lignin-containing resin adhesive
US4303562A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 24, 1980 |
| Grant date | Dec 1, 1981 |
| Priority date | — |
| Expiry date | Jul 24, 2000 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09J197/005
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Novel lignin-phenol-formaldehyde resins, suitable for use as wood bonding adhesives, are provided by a two-step method which comprises reacting formaldehyde and phenol in the presence of an alkaline catalyst for a period sufficient to produce a partially condensed phenol-formaldehyde resin, thereafter reacting said precondensed resin with sodium hydroxide, formaldehyde and a lignin concentrate having at least 40% solids and comprising lignin dissolved in (a) phenol and water; or (b) phenol, water and sodium hydroxide or ammonia, the lignin to phenol weight ratios in said solution being less than 70:30 and more than 40:60. The second stage of the method is conducted at reflux temperature initially after which reaction is conducted below reflux temperature to control the degree of condensation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.