Free-flowing urea resin compositions with silane or siloxane additive added before hardening

In the manufacture of a urea-formaldehyde molding composition wherein:

• A. a liquid urea-formaldehyde resin composition is formed by condensing a urea with a formaldehyde;
• B. said resin is combined with a filler;
• and
• C. to said filler containing urea-formaldehyde resin composition there is added a hardening accelerator to harden said composition to a solid urea-formaldehyde molding composition, the improvement for improving the free-flowing qualities of the resultant solid urea-formaldehyde molding composition when heated at elevated temperatures which comprises introducing into said liquid urea-formaldehyde resin prior to hardening:
• A. a polyorganosiloxane having recurring units of the formula
• X(R).sub.a SiO.sub.3-a/ 2
• wherein
• X is alkyl, alkylene or a hydrocarbon radical having a functional group;
• R is hydrogen, alkyl, alkoxy or aryl;
• a is a value from 0 to 2;
• in an amount of 0.05 to 1.6 weight percent based on the weight of the urea in the resin
• or
• B. a silane of the formula
• Y--A.sub.n --Si(R").sub.b (OR').sub.3--b
• wherein
• Y is a substituted or unsubstituted amino, carboxyl, glycidyl, mercapto or alkenyl group;
• A is a bivalent straight or branched-chained alkylene radical which can contain oxygen in the chain;
• R' is an alkyl or hydroxyl alkyl radical;
• R" is a C.sub.1-4 alkly radical;
• n is 0 or 1, and
• b is 0, 1 or 2;
• or a hydrolysis product thereof in an amount of 0.8 to 3.0 weight percent based on the weight of urea in said resin.