摘要 |
Aqueous dispersions of a phenolic resole and a thermoplastics polymeric material or a rubber, suitable for use as adhesives, are prepared by (a) dissolving a solid thermoplastics polymeric material, such as a polyvinyl acetal or a nylon polyamide, or rubber in a phenol, (b) adding a nonionic or anionic surface active agent and/or protective colloid, (c) adjusting the mixture to a pH above 7 by addition of a base, (d) adding aqueous formaldehyde solution, or a formaldehyde donor, to a molar ratio of phenol to formaldehyde within the range 1:1 to 1:3, (e) if necessary, adding water, and (f) heating the mixture to form a phenolic resole.
|