METHOD OF PRODUCING WATER-SOLUBLE RESOL-TYPE PHENOL-FORMALDEHYDE RESIN Russian patent published in 1994 - IPC

FIELD: chemical industry; manufacture of abrasive materials and tools. SUBSTANCE: water-soluble resol-type phenol-formaldehyde resin was prepared by polycondensation of phenol with formaldehyde in the presence of alkaline catalyst (sodium hydroxide) reaction admixture boiling temperature during 40 to 50 min to obtain water-soluble resin (170 to 190 % ). Polycondensation completed, resin was allowed to dry in vacuum to refraction coefficient of 1.555 to 1.560, added with 25-percent aqueous solution of ammonia and glycerine and then resin was further allowed to dry to refraction coefficient of at least 1.562 and viscosity of 1,500 to 3,000 MPa. s. Mass ratio of phenol, formaldehyde, sodium hydroxide, aqueous solution of ammonia and glycerine was 100 : (49 to 51) : 2.5 to 3.0) : (0.4 to 0.6) : (7.5 to 8.5) respectively. EFFECT: more effective binder for abrasives. 3 tbl