Modified phenol resins

摘要

Modified phenolic resins and processes for producing these are described, as also are phenolic-resin formulations which comprise the modified phenolic resins, and processes for producing these. Specific uses of appropriate phenolic resins and, respectively, phenolic-resin formulations, and the use of block copolymers for producing phenolic resins, are also described.

主权项

1. A phenolic resin with increased crosslinked density, comprising: a block copolymer, said block copolymer being a reaction product of a soft segment which is a liquid rubber with a hard segment which comprises aromatic units, wherein the phenolic resin is characterized by stable methylene bridges joined to said aromatic unit residue and formed by a chemical reaction of a phenolic compound with an aldehyde compound, such that the block copolymer is incorporated into the phenolic resin by way of increased crosslinking, wherein the proportion of block copolymer in the phenolic resin is from 0.5 to 15% by weight, based on the phenolic component wherein the phenolic resin is transparent and homogenous and exhibits no phase separation within 2 months at 8° C.