COPOLIMEROS DE INJERTO ELASTOMEROS CON ESTRUCTURA DE NUCLEO Y ENVOLTURA

COPOLIMEROS ELASTOMEROS EN FORMA DE PARTICULAS CON ESTRUCTURA DE ENVOLTURA DE NUCLEO A) CONSTANDO DE UN POLIMERO ORGANOSILICEO Y UNA ENVOLTURA ORGANOPOLIMERA C) DOS ENVOLTURAS B) Y C), CON LO CUAL, LA ENVOLTURA INTERIOR CONSTA DE UN POLIMERO ORGANOSILICEO, Y EL COPOLIMERO SE COMPONE DE A) DE 0.05 A 95% DEL PESO, REFERENTE AL PESO TOTAL DEL COPOLIMERO, DE UN POLIMERO DE NUCLEO (R SUB 2 SIO SUB 2/2)SUB X (RSIO SUB 2/2)SUB Y (SIO SUB 4/2)SUB Z CON X=0 A 99.5 MOL, Y=0.5 HASTA 100% MOL, Z=0 HASTA 50% MOL, B) DE 0 A 94.5% DEL PESO, REFERIDO AL PESO TOTAL DEL COPOLIMERO, UNA ENVOLTURA DE POLIDIALQUILSILOXAN DE UNIDADES DE (R SUB 2 SIO SUB 2/2) C) DE 5 HASTA 95% DEL PESO, REFERIDO AL PESO TOTAL DEL COPOLIMERO, UNA ENVOLTURA DE ORGANOPOLIMERO DE MONOMEROS MONOOLEFINICOS NO SATURADOS, Y LAS PARTICULAS TIENEN UN TAMAÑO DE PARTICULAS 10 A 300 NM Y UN REPARTO DEL TAMAÑO DE PARTICULAS MONOMODALMENTE CON UN INDICE DE POLIDISPERSION MAXIMO DE (SIGMA) SUB 2=0.2. LA INVENCION CONSISTE ADEMAS EN UN PROCEDIMIENTO PARA LA FABRICACION DE LOS COPOLIMEROS PARA INJERTO. LOS COPOLIMEROS PARA INJERTO, SEGUN LA INVENCION, SON APROPIADOS ESPECIALMENTE PARA SU EMPLEO COMO TERMOPLASTICOS MODIFICADOS, ASI COMO PARA SU USO COMO ADITAMENTOS PARA LA MODIFICACION DE POLIMERO. Elastomeric particulate copolymers having a core/shell structure composed of a core (a) comprising an organosilicon polymer and an organopolymeric shell (c) or two shells (b) and (c), the inner shell (b) comprising an organosilicon polymer, and the copolymer being composed of (a) from 0.05 to 95 percent by weight, based on the total weight of the copolymer, of a core polymer (R2SiO2/2)x.(RSiO3/2)y.(SiO4/2)z where x=0 to 99.5 mol%, y=0.5 to 100 mol% and z=0 to 50 mol%, (b) from 0 to 94.5 percent by weight, based on the total weight of the copolymer, of a polydialkylsiloxane shell comprising (R2SiO2/2) units, and (c) from 5 to 95 percent by weight, based on the total weight of the copolymer, of a shell comprising an organopolymer of monoolefinically unsaturated monomers, and the particles have a particle size of from 10 to 300 nm and a monomodal particle size distribution having a maximum polydispersity index sigma 2=0.2. The invention furthermore relates to a process for preparing the graft copolymers. The graft copolymers of this invention are particularly suitable for use as modified thermoplastics or for use as additives for modifying polymers.