Ethyl Corporation

Albemarle Corporation

General Electric Company

Ablemarle Corporation

John Semen

John J Rogers

Edwin D Hornbaker

Willem F Borman

Robert J Axelrod

Jesse D Jones

Frank N Liberti

William E Moehle

A compacted particulate polymer additive composition in a dry granular form formed from a substantially uniform mixture of the following components:

Granular polymer additives and their preparation

Sterically hindered phenol antioxidant additive granules are formed from a paste comprising an organic processing agent comprising a friability reduction agent. The friability reduction agent preferably is an alcohol, more preferably an alkanol having up to about 8 carbon atoms, most preferably methanol, ethanol, and/or isopranol. After drying, the granules consist essentially of the sterically hindered phenol antioxidant additive system. The granules have a balanced hardness that provides sufficient abrasion resistance while permitting ready dispersion into a polymer host.

Sterically hindered phenol antioxidant granules having balanced hardness

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.

Additive system for polymers in pellet form which provides proportioned stabilization and internal mold release characteristics

The present invention is directed to a process for the production of agglomerates of a sterically hindered phenol antioxidant such that the agglomerates have a balanced hardness so as to resist abrasion during conveyance yet being readily dispersed in a host plastic. Such novel agglomerates are achieved through the use of a processing aid consisting of a solvent selected from the group consisting of methylene chloride, chloroform, toluene, acetone, methylethylketone, xylene, cyclohexane, styrene, methylcyclohexane and hexane having at least one gram of antioxidant dissolved therein per 100 mL of solvent and from about 20 to about 50 weight percent of an alcohol of the formula ROH wherein R is an alkyl group of 1 to 8 carbon atoms and thereafter using the resulting solution of solvent, alcohol, and antioxidant to form a paste of additional portions of the antioxidant which is thereafter agglomerated and dried. The present invention further provides a novel process for controlling the hardness of an agglomerated sterically hindered phenol antioxidant or a mixture of such antioxidant and a secondary phosphite antioxidant through the use of a processing aid wherein there is employed from 20 to about 50 weight percent of an alcohol of the formula ROH and wherein the hardness of the resulting agglomerate is inverse to the amount of alcohol employed in the system.

Low dust balanced hardness antioxidant agglomerates and process for the

The present invention is directed to a process for the production of agglomerates of a blend of a sterically hindered phenol antioxidant and an acid neutralizer such that the agglomerates have a balanced hardness to resist abrasion during conveyance yet being readily dispersed in a host plastic. Such agglomerates are achieved through the use of a processing aid consisting of an alcohol of the formula ROH wherein R is an alkyl group of 1 to 8 carbon atoms, either alone or having up to 80% by volume of a cosolvent selected from the group consisting of methylene chloride, chloroform, toluene, acetone, methylethylketone, xylene, cyclohexane, styrene, methylcyclohexane, and hexane. The cosolvent processing aid has at least 1 gram of antioxidant dissolved therein per 100 mL of solvent. The processing aids are used to form a paste of a mixture of antioxidant and an acid neutralizer. The resulting paste is then subjected to agglomeration and the resulting agglomerates are thereafter dried. Through the controlled use of alcohol in the processing aid there is achieved a control on the hardness of the resulting agglomerates which is inverse to the amount of alcohol employed in the system.

The present invention is directed to a process for the production of pellets of a sterically hindered phenol antioxidant such that the pellets have a balanced hardness so as to resist abrasion during conveyance yet being readily dispersed in a host plastic. Such novel pellets are achieved through the use of a processing aid consisting of a solvent selected from the group consisting of methylene chloride, chloroform, toluene, acetone, methylethylketone, xylene, cyclohexane, styrene, methylcyclohexane and hexane having at least 1 gram of antioxidant dissolved therein per 100 grams of solvent and thereafter using the resulting solution of solvent and antioxidant to form a paste of additional portions of the antioxidant which is thereafter extruded, pelleted, and dried. The present invention further provides a novel process for controlling the hardness of a pelleted sterically hindered phenol antioxidant through the addition of from 0 to 80 weight percent of an alcohol of the formula ROH wherein R is an alkyl group of from 1 to 8 carbon atoms to the solvent system employed in the preparation of the processing aid and paste of antioxidant for further processing. The hardness of the resulting pellets is inverse to the amount of alcohol employed in the system.

Low dust balanced hardness antioxidant pellets and process for the

Low density silicon nitride ceramics having improved bending an specific strengths over known silicon nitride ceramics derived from silicon nitride powder and polysilazane precursors are prepared by (A) intimately mixing about 50-80% by weight of silicon nitride powder with about 15-50% by weight of perceramic polysilazane binder, (B) pulverizing the mixture to form particles having a particle size smaller than 105 micrometers, (C) separating from those particles any particles having a particle size larger than about 105 micrometers, (D) molding the resultant composition having a particle size not larger than about 105 micrometers, and (E) pyrolyzing the molded composition in an inert atmosphere to a temperature of about 1200.degree.-1450.degree. C.; said preceramic binder being at least one polysilazane prepared by reacting an organodihalosilane with ammonia, treating the ammonolysis product with a basic catalyst which is capable of deprotonating an NH group that is adjacent to an SiH group, and quenching the resultant product with an electrophilic quenching reagent.

Preceramic compositions and ceramic products

Preceramic molding compositions capable of forming low density ceramics having acceptable strength and improved wear resistance are compositions having a particle size not larger than about 105 micrometers and comprising an intimate mixture of (A) about 50-90 parts by weight of powder ingredients comprising about 2-50% by weight of graphite powder and about 98-50% by weight of a second powder selected from silicon carbide, silicon nitride, and mixtures thereof and (B) correspondingly, about 50-10 parts by weight of a preceramic polysilazane binder.

Low density silicon nitride ceramics having improved bending and specific strengths over known silicon nitride ceramics derived from silicon nitride powder and polysilazane precursors are prepared by (A) intimately mixing about 50-85% by weight of silicon nitride powder with about 15-50% by weight of a preceramic polysilazane binder, (B) pulverizing the mixture to form particles having a particle size smaller than 105 micrometers, (C) separating from those particles any particles having a particle size larger than about 105 micrometers, (D) molding the resultant composition having a particle size not larger than about 105 micrometers, and (E) pyrolyzing the molded composition in an inert atmosphere to a temperature of about 1200.degree.-1450.degree. C.; said preceramic binder being at least one polysilazane prepared by reacting an organodihalosilane with ammonia, treating the ammonolysis product with a basic catalyst which is capable of deprotonating an NH group that is adjacent to an SiH group, and quenching the resultant product with an electrophilic quenching reagent.

Preceramic compositions

Low density SiC ceramics having improved bending and specific strengths are prepared by (A) intimately mixing about 50-85% by weight of SiC powder with about 15-50% by weight of a preceramic polysilazane binder, (B) pulverizing the mixture to form particles having a particle size smaller than 105 micrometers, (C) separating from those particles any particles having a particle size larger than about 105 micrometers, (D) molding the resultant composition having a particle size not larger than about 105 micrometers, and (E) pyrolyzing the molded composition in an inert atmosphere to a temperature of about 1200.degree.-1450.degree. C. In a preferred embodiment of the invention, the preceramic binder is at least one polysilazane prepared by reacting an organodihalosilane with ammonia, treating the ammonolysis product with a basic catalyst which is capable of deprotonating an NH group that is adjacent to an SiH group, and quenching the resultant product with an electrophilic quenching reagent.

The strength of SiC ceramic parts derived from certain preceramic compositions is improved by (A) cooling the parts in an inert atmosphere to a temperature at least as low as about 800.degree. C. after preparing them by molding and pyrolyzing the preceramic compositions, (B) then heating them in air to about 1200.degree.-1300.degree. C., and (C) keeping them in air at that temperature for at least about one hour before allowing them to cool. The preceramic compositions from which the ceramics are derived are mixtures of SiC powders and polysilazanes having an alkali metal content of 0-100 ppm and prepared by reacting an organodihalosilane with ammonia, treating the ammonolysis product with a basic catalyst which is capable of deprotonating an NH group that is adjacent to an SiH group, and quenching the resultant product with an electrophilic quenching reagent.

Process for improving strength of SiC ceramics

The inter-layer adhesion of laminates comprised of alternating layers of thermoplastic polyester and ethylene-vinyl acetate copolymer is greatly enhanced by a method of treatment of the laminate with a stream of inert gas at elevated temperatures which is described. The treated articles in general exhibit a T-peel strength of 1 in. lb./in..sup.2 and greater, which is far in excess of the peel strengths typical of the untreated article.

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Baton Rouge, LA, United States of America

John Semen