A compacted particulate polymer additive composition in a dry granular form formed from the following components: (a) at least one particulate organic phosphite, organic phosphonite, and/or organic phosphonate, and (b) one or more particulate polymer additives other than an organic phosphite, organic phosphonite, or organic phosphonate; wherein the particles of said composition are held together in compacted dry granular form exclusively or substantially exclusively by contact with dried surfaces of in situ desolvated particles from particles of one or more at least partially solvated components of (a), and optionally by contact with dried surfaces of in situ desolvated particles from particles of one or more at least partially solvated components of (b). Compositions of this type except that there is no component (b) are also described.

The present invention provides a mineral filled thermoplastic olefin (MFTPO) composition comprising a polymer mixture, a mineral and a flexural modulus modifying agent and/or a heat deflection temperature modifying agent, and a method for producing the same. The flexural modulus modifying agent and/or a heat deflection temperature modifying agent significantly increases the flexural modulus and/or a heat deflection temperature of the MFTPO without substantially affecting the falling weight impact resistance of the MFTPO relative to a similar MFTPO composition which lacks the flexural modulus modifying agent and/or a heat deflection temperature modifying agent.

A pelleted stabilizer additive system and a method of making same with a good pellet yield, preferably at least about 90 wt. %. The stabilizer additive system comprises at least a stabilizer and a processing aid, preferably a mold release agent. The processing aid has a lower melting temperature than the stabilizer. The stabilizer comprises less than 50 wt. % the combined total weight of the stabilizer and the mold release agent.

A compacted particulate polymer additive composition in a dry granular form formed from a substantially uniform mixture of the following components: (a) at least one particulate sterically-hindered phenolic compound; and (b) one or more particulate polymer additives other than a sterically-hindered phenolic compound; wherein the particles of said composition are held together in compacted dry granular form exclusively or substantially exclusively by contact with dried surfaces of in situ desolvated particles from particles of one or more at least partially solvated components of (a), and optionally by contact with dried surfaces of in situ desolvated particles from particles of one or more at least partially solvated components of (b). Compositions of this type except that there is no component (b) are also described.