This invention relates broadly to the chemical modification of wool by reacting it simultaneously with a halogenated acid anhydride and an isocyanate. In particular, the invention concerns and has as its prime object the provision of processes wherein the reaction of wool with the above reagents is conducted in the presence of cresol, whereby to facilitate and promote the reaction. The unqualified term "cresol" used herein includes o-cresol, m-cresol, p-cresol, or any mixture of these isomers. Further objects and advantages of the invention will be apparent from the following description wherein parts and percentages are by weight, unless otherwise specified.
Although wool is a very useful fiber, it is often desirable to improve its properties for particular applications by chemically modifying it. Previously, wool has been shrinkproofed with isocyanates, but the product is not flameproof. Furthermore, wool has been flameproofed with halogenated acid anhydrides, but the product does not meet consumer requirements for shrinkproofing.
Wool which is both shrinkproof and flameproof has also been prepared. However, a two-step process is required-- the wool is first shrinkproofed and then flameproofed. The two-step process has the disadvantage of being less efficient and economical than a one-step process.