Resinous butadiene/styrene reinforcing copolymers

Claim 2

A BUTADIENE/STYRENE COPOLYMER REINFORCING RESINS PREPARED BY A TWO STEP POLYMERIZATION PROCESS COMPRISING THE STEPS OF (A) POLYMERIZING, UNDER AQUEOUS EMULSION POLYMERIZATION CONDITIONS, A FIRST MONOMERIC MIXTURE CONSISTING OF FROM 5 TO 15 PARTS BY WEIGHT OF BUTADIENE MONOMER AND FROM 95 TO 85 PARTS BY WEIGHT OF STYRENE MONOMER, ALL PARTS BASED ON THE TOTAL WEIGHT OF THE COMBINED MONOMERS POLYMERIZED IN STEP (A) TO OBTAIN A FIRST BUTADIENE/STYRENE COPOLYMER LATEX AND (B) ADDING TO AND POLYMERIZING IN SAID FIRST BUTADIENE/STYRENE COPOLYMER LATEX A SECOND MONOMERIC MIXTURE CONSISTING OF FROM 20 TO 35 PARTS BY WEIGHT OF BUTADIENE MONOMER AND FROM 80 TO 65 PARTS BY WEIGHT OF STYRENE MONOMER, ALL PARTS BASED ON THE TOTAL WEIGHT OF THE COMBINED MONOMERS POLYMERIZED IN STEP (B) WHEREIN THE RARIO OF THE TOTAL WEIGHT OF THE COMBINED MONOMERS IN STEP (A) TO THE TOTAL WEIGHT OF THE COMBINED MONOMERS IN STEP (B) RANGES FROM 75/25 TO 25/75 AND WHEREIN THE MONOMERIC MIXTURE POLYMERIZED IN STEP (A) RANGES FROM 5 TO 32 PERCENT BY WEIGHT HIGHER IN STYRENE CONTENT THAN THE MONOMERIC MIXTURE ADDED POLYMERIZED IN STEP (B).

Claim 3

Butadiene/styrene copolymer reinforcing resins according to claim 1 characterized by Mooney viscosities, as determined by ASTM D-1646 ranging from about 50 to about 70; Olson Flow times as determined by ASTM D-569 at 120* C. ranging from about 0.5 to about 8.0 seconds and softening points ranging from about 40* to about 60* C.

Claim 4

A two step polymerization process for preparing butadiene/styrene copolymer reinforcing resins, said resins being characterized by Mooney viscosities as determined by ASTM D-1646 ranging from about 50 to about 70; Olson Flow times as determined by ASTM D-569 at 120* C. ranging from about 0.5 to about 8.0 seconds and softening points ranging from about 40* to about 60* C., comprising the steps of (A) polymerizing, under aqueous emulsion polymerization conditions, a first monomer mixture consisting of from 5 to 15 parts by weight of butadiene monomer and from 95 to 85 parts by weight of styrene monomer, all parts based on the total weight of the combined monomers polymerized in step (A) to obtain a first butadiene/styrene copolymer latex and (B) adding to and polymerizing in said first butadiene/styrene copolymer latex a second monomeric mixture consisting of from 20 to 35 parts by weight of butadiene monomer and from 80 to 65 parts by weight of styrene monomer, all parts based on the total weight of the combined monomers polymerized in step (B) wherein the ratio of the total weight of the combined monomers polymerized in step (A) to the total weight of the combined monomers polymerized in step (B) ranges from 75/25 to 25/75 and wherein the monomeric mixture polymerized in step (A) ranges from 5 to 32 percent by weight higher in styrene content than the monomeric mixture added and polymerized in step (B).

Claim 5

A two step polymerization process for preparing butadiene/styrene copolymer reinforcing resins, said resins being characterized by Mooney viscosities as determined by ASTM D-1646 ranging from about 50 to about 70; Olson Flow times as determined by ASTM D-569 at 120* C. ranging from about 0.5 to about 8.0 seconds and softening points ranging from about 40* to about 60* C., comprising the steps of (A) polymerizing, under aqueous emulsion polymerization conditions, a first monomer mixture consisting of from 5 to 15 parts by weight of butadiene monomer and from 95 to 85 parts by weight of styrene monomer, all parts based on the total weight of the combined monomers polymerized in step (A) to obtain a first butadiene/styrene copolymer latex and (B) adding to and polymerizing in said first butadiene/styrene copolymer latex a second monomeric mixture consisting of from 20 to 35 parts by weight of butadiene monomer and from 80 to 65 parts by weight of styrene monomer, all parts based on the total weight of the combined monomers polymerized in step (B) wherein the ratio of the total weight of the combined monomers polymerized in step (A) to the total weight of the combined monomers polymerized in step (B) ranges from 75/25 to 25/75 and wherein the monomeric mixture polymerized in step (A) ranges from 5 to 32 percent by weight higher in styrene content than the monomeric mixture added and polymerized in step (B).