Abstract: A process is disclosed for manufacturing coupled radial block copolymers of the S—B—Li type having improved optical properties, which process utilizes coupling agents having from about 3 to about 7 epoxy groups per mole.

Abstract: A process for reducing the water take up of a vinyl aromatic-conjugated diene polymer when subjected to a humid environment, the process comprising solution polymerising at least one vinyl aromatic hydrocarbon and a conjugated diene in the presence of a catalyst based on an alkali metal to produce alkalimetal derivatives of a vinyl aromatic-conjugated diene polymer and neutralising the derivatives with a C9-C16 alkyl dicarboxylic acid.

Abstract: A process for producing a vinyl aromatic-conjugated diene block copolymer, the process comprising solution polymerising at least one vinyl aromatic hydrocarbon and a conjugated diene in the presence of a catalyst based on an alkali metal to produce copolymer chains which end with an alkali metal and treating the copolymer chains in solution with an alkyl dicarboxylic acid having at least 2 carbon atoms and the acid being in the form of a slurry in an organic liquid with the acid being granulated and having an average granule size of less than 50 microns.

Abstract: The present invention relates to bituminous compositions used for roofing and waterproofing membranes or material comprising asymmetrical coupled polyvinyl aromatic-polydiene block copolymers having improved physical properties over broader ranges of service temperatures than those obtained from bituminous compositions prepared with symmetrical block copolymers of similar type. The asymmetry of the copolymer which is characterised by polyvinyl aromatic endblocks of at least two different molecular weights, one high and one low, ensures improved physical performance to roofing and waterproofing membranes made from such compositions.

Abstract: A process for eliminating color from vinyl aromatic/conjugated diene copolymers which process comprises treating the copolymers with a monocarboxylic acid having general formula R—COOH, where R is a hydrocarbon radical comprising 2 to 4 carbon atoms and R further comprises linear or branched aliphatic radicals, cycloaliphatic radicals, alkenic radicals, aromatic radicals or alkylaromatic radicals.

Abstract: A process is disclosed for manufacturing coupled radial block copolymers of the S-B-Li type having improved optical properties, which process utilizes coupling agents having from about 3 to about 7 epoxy groups per mole.

Abstract: The present invention related to a process for the treatment of vinyl aromatic/conjugated diene block copolymers. More particularly, the present invention relates to a process for the treatment of such copolymers obtained starting from a (co)polymerization-initiating stage performed by means of alkaline based catalysts (Me), deactivated in such a way that they show a termination of the alkali metal-alcoholate type (--O--Me), and treated with a cyclic anhydride of polycarboxylic acid, and optically a C.sub.2 -C.sub.4 monocarboxylic acid.

Abstract: A process for eliminating color from vinyl aromatic/conjugated diene copolymers which process comprises treating the copolymers with a monocarboxylic acid having the general formula R--COOH, where R is a hydrocarbon radical comprising 2 to 4 carbon atoms and R further comprises linear or branched aliphatic radicals, cycloaliphatic radicals, alkenic radicals, aromatic radicals or alkylaromatic radicals.

Abstract: The present invention relates to bituminous compositions used for roofing and waterproofing membranes or material comprising asymmetrical linear polyvinyl aromatic-polydiene block copolymers having improved physical properties over broader ranges of service temperatures than those obtained from bituminous compositions prepared with symmetrical block copolymers of similar type.The asymmetry of the copolymer which is characterised by polyvinyl aromatic endblocks of at least two different molecular weights, one high and one low, ensures improved physical performance to roofing and waterproofing membranes made from such compositions.

Abstract: Coupling of block base copolymers terminated by a lithium atom of the typical formula S-B-Li, in which S is a monovinylaromatic hydrocarbon block and B is a conjugated diene block, by the use of at least one difunctional deactivating coupling agent and at least one polyfunctional deactivating coupling agent in a molar ratio such that the linear polymer obtained by coupling represents 65 to 95% by weight of the total polymer material obtained by coupling.

Abstract: Transparent linear resinous conjugated diene/monovinyl-substituted aromatic block copolymers of improved properties are prepared by forming a monovinyl-substituted aromatic homopolymer block referred to as S.sub.1, followed by forming a conjugated diene homopolymer block, referred to as B.sub.1 and linked to segments S.sub.1, followed by the formation of a conjugated diene/monovinyl-substituted aromatic random copolymer block, referred to as B/S and linked to segment B.sub.1, followed by the formation of a monovinyl-substituted aromatic homopolymer block, referred to as S.sub.2 and linked to segment B/S thereby forming the block copolymer S.sub.1 -B.sub.1 -B/S-S.sub.2 wherein the molecular weight of the S.sub.2 block is significantly greater than the molecular weight of the S.sub.1 block.

Abstract: Vinyl aromatic-conjugated diene copolymers having polymer chains which end with an alkali metal and which are obtained by the polymerization in solution of at least one vinyl aromatic hydrocarbon and of a conjugated diene in the presence of a catalyst based on an alkali metal are decolorized by treating the copolymer with a monocarboxylic acid of general formula(Y).sub.2-n --X--(R--COOH).sub.nin which X is S, S--CH.sub.2 --S, or S--S, and Y and R are alkyl radicals having 1 to 16 carbon atoms and n is 1 or 2.

Abstract: A continuous mass polymerization process for preparing rubber reinforced styrenic copolymers comprising forming a solution in an inert solvent of a styrenic polymer matrix and a monomer material capable of polymerizing to form a cross-linked rubbery polmyer, continuously charging the solution into a polymerization reactor and subjecting the solution to mass polymerization conditions whereby there is formed in situ a cross-linked rubbery polymer dispersed in the styrenic polymer matrix, continuously withdrawing the reaction mixture from the polymerization reactor and recovering the resulting rubber reinforced styrenic copolymer.

Abstract: A continuous process for preparing rubber reinforced resins which are copolymers of styrenic compound, acrylonitrile and diolefinic compound.

Abstract: A continuous process for polymerizing a monomer mixture of acrylate and diolefinic compound in the presence of a copolymeric matrix of styrene and acrylonitrile.

Abstract: Disclosed is an ABS type polyblend composition exhibiting improved physical properties, which comprises from about 5 to 60% by weight of a copolymer of styrene and acrylonitrile; from about 10 to 70% by weight of a graft copolymer of styrene, acrylonitrile, and a butadiene polymer having an average rubber particle size of from about 1 to 10.mu.; and from about 10 to 70% of a high butadiene content backbone copolymer of styrene, acrylonitrile, and a butadiene polymer having an average rubber particle size of less than abut 0.5.mu., the ratios of the backbone copolymer and the styrene-acrylonitrile-butadiene polymer copolymer being adjusted such that from about 15 to 25% by weight of the total butadiene polymer content of the polyblend is provided by the larger rubber particle size graft copolymer.

Abstract: An improved process for preparing rubber reinforced styrenic resins which are composite systems containing a copolymer of styrene and unsaturated nitrile together with copolymers of acrylates and conjugated diolefins.

Abstract: Disclosed is a process for the production of rubber-modified styrene copolymers, particularly high rubber content styrene copolymers, such as high rubber content ABS polymers, by suspension polymerization, comprising suspension polymerizing an admixture of polymerizable materials comprising styrene monomer, rubber polymer, and optional additional monomers copolymerizable therewith; and melt extruding the resultant rubber-modified styrene copolymer under extrusion conditions having a shear force sufficient to homogeneously disperse the rubber phase throughout the copolymer. Through the use of the process of the instant invention, high rubber content styrene copolymers may be produced in a single suspension step, with impact properties and surface appearance comparable to copolymers produced in the conventional two-step polymerization process.

Abstract: An improved high-impact polystyrene is disclosed comprising a blend of a polystyrene having a large rubber particle size and a polystyrene having a very fine rubber particle size, combined in such proportions that an improved balance of properties is achieved. Preferably, each polystyrene graft copolymer is prepared by a mass-suspension polymerization process and has a specific degree of grafting.

Abstract: The present invention relates to bituminous compositions used for roofing and waterproofing membranes or material comprising asymmetrical linear polyvinyl aromatic-polydiene block copolymers having improved physical properties over broader ranges of service temperatures than those obtained from bituminous compositions prepared with symmetrical block copolymers of similar type. The asymmetry of the copolymer which is characterised by polyvinyl aromatic endblocks of at least two different molecular weights, one high and one low, ensures improved physical performance to roofing and waterproofing membranes made from such compositions.