Lignin-modified phenolic adhesives for pressed wood products
AssigneeReichhold, Inc.
InventorsStamatis M. Kambanis, Antoine Berchem, Dennis Gregoire, Jaroslav Rybicky
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Abstract
An improved modified phenol-formaldehyde resin, and a process for its preparation, which contains lignosulfonates is described. Typically, the lignosulfonates are in the form of black liquor. These resins are made by including with the phenol a small amount of potassium ferricyanide. Unlike the known processes utilizing black liquors and the like, this process appears to be far less susceptible to the inherent variability of these liquors. These resins can be easily converted into a solid by spray drying, and find use as adhesives, for example in board products.
Claims35
A process for the preparation of a lignin-modified phenol-formaldehyde resin which comprises reacting together phenol, formaldehyde, lignosulfonate, potassium ferricyanide, and an alkali or alkaline earth basic catalyst in the following ratios:
- (a) phenol/formaldehyde:
- from 1:1.8 to 1:3.0, on a molar basis;
- (b) phenol/basic catalyst:
- from 1:0.1 to 1:0.5, on a molar basis;
- (c) phenol/potassium ferricyanide:
- from 100:1 to 10:1, on a weight basis;
- and
- (d) phenol/lignosulfonate:
- from 1:0.1 to 1:0.5 on a weight basis as lignosulfonate solids, or from 1:0.2 to 1:1.0 on a weight basis as lignosulfonate liquor containing approximately 50% by weight solids,
- and continuing the reaction until a desired viscosity is reached, provided that the potassium ferricyanide is added either with or before the phenol.
A modified phenol-formaldehyde resin containing lignosulfonate, obtained by reacting together phenol, formaldehyde, lignosulfonate, potassium ferricyanide, and an alkali or alkaline earth basic catalyst in the following ratios:
- (a) phenol/formaldehyde:
- from 1:1.8 to 1:3.0, on a molar basis;
- (b) phenol/basic catalyst:
- from 1:0.1 to 1:0.5, on a molar basis;
- (c) phenol/potassium ferricyanide:
- from 100:1 to 10:1, on a weight basis;
- and
- (d) phenol/lignosulfonate:
- from 1:01 to 1:0.5 on a weight basis as lignosulfonate solids, or from 1:0.2 to 1:1.0 on a weight basis as lignosulfonate liquor containing approximately 50% by weight solids, and continuing the reaction until a desired viscosity is reached, provided that the potassium ferricyanide is added either with or before the phenol.
Dependencies are inferred from the claim text.