Abstract: In order to prevent a thermoplastic resin possessing an unsaturated nitrile unit from discoloration, the thermoplastic resin prepared by copolymerizing at least an unsaturated nitrile compound as a polymerizing component in the presence or absence of a rubbery polymer is blended with 2,4-di-t-amyl-6-[1-(3,5-di-t-amyl-2-hydroxyphenyl)ethyl]phenyl acrylate. The resulting composition shows little discoloration during the production and processing stages.

Abstract: A polyolefin composition comprising a polyolefin, and the following components:(A) a phenolic compound such as 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate;(B) an acrylate compound represented by the formula (I): ##STR1## wherein R.sup.1 is an alkyl of 1 to 5 carbon atoms, R.sup.2 is an alkyl of 1 to 8 carbon atoms, R.sup.3 is hydrogen or an alkyl of 1 to 8 carbon atoms, and R.sup.4 is hydrogen or methyl;(C) an organic phosphorous compound such as bis(2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite; and(D) a hindered piperidine compound such as poly[{6-(1,1,3,3-tetramethylbutyl)imino-1,3,5-triazin-2,4-diyl}{(2,2,6,6-t etramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl )imino}]. This composition is stable against thermal processing, thermal oxidation, light oxidation and discoloration, and it is especially useful for fibers and films.

Abstract: In a process for producing a thermoplastic resin by emulsion polymerization using a conjugated diene rubber, an aromatic vinyl compound and a vinyl cyanide compound, and by successive flocculation and direct pelletizing, the direct pelletizing is effected in the presence of a phenolic compound represented by ##STR1## wherein R.sup.1 and R.sup.4 are each hydrogen or methyl, and R.sup.2 and R.sup.3 are each an alkyl of 1 to 9 carbon atoms. The use of the phenolic compound is effective to prevent the resin from thermal deterioration during the direct pelletizing, thereby producing the thermoplastic resin excellent in properties such as impact resistance.

Abstract: A polyolefin composition comprising a polyolefin, and the following components:(A) a phenolic compound which is a derivative of pentaerythritol,(B) a phenolic acrylate compound,(C) at least one organic phosphorous compound such as bis(2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite. This composition is stable against thermal processing, thermal oxidation and discoloration, and it is especially useful for fibers and films. Further incorporation of a polycondensate of dimethyl succinate with 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine is effective to inprove the light stability of the composition.

Abstract: Tris[2-hydroxy-3-(2,2,6,6-tetramethyl-4-piperidylamino)propyl] isocyanurate is useful as a light stabilizer for organic materials. A composition comprising an organic material and the isocyanurate is stable against light and also excellent in heat resistance. The isocyanurate can be produced by the reaction between tris(2,3-epoxypropyl) isocyanurate and 4-amino-2,2,6,6-tetramethylpiperidine.

Abstract: A compound represented by the formula of: ##STR1## wherein R is hydrogen or methyl. This compound is useful as a stabilizer for butadiene polymers.