Abstract: A novel class of compounds is disclosed of the formula ##SPC1##Wherein R.sub.1 and R.sub.2 are lower-alkoxy or di(lower-alkyl)amino and R.sub.1 can be hydrogen and R.sub.3 and R.sub.4 are hydrogen, lower-alkoxy or di(lower-alkyl)amino and n is an integer from 1 to 5. The compounds are sensitizers for photosensitive compounds particularly polymers containing sulfonazido groups as the light-sensitive moiety.

Abstract: Methods and apparatus are disclosed for continuous mixing of formulations for urethane products. A hydroxyl mixture and isocyanate, the major foam components, are supplied to a mixer. In the mixer, the components are mixed by transverse shearing and agitation means. The degree of agitation is varied along the length of the mixer, which runs at a constant speed, by varying the shearing pin configuration. The flow path through the mixer is arranged to control pressure on the fluid as well as minimize the tendency of internal foam build-up to occur.