Abstract: Disclosed are a polybutadiene having a controlled microstructure, a narrow molecular weight distribution, minimal gel content, and a low APHA color, a modified polybutadiene, producing methods for both, and a rubber-reinforced styrene resin composition using the same. The polybutadiene of the present invention is characterized in that the ratio (Tcp/ML1+4) of a 5% toluene melting viscosity (Tcp) measured at 25° C. and the Mooney viscosity (ML1+4) at 100° C. is 2.0 or higher, the molecular weight distribution (Mw/Mn) is 2.80 or less, the gel content is 0.06 wt % or less, and the APHA color is 20 or less.

Abstract: A process for making a substantially saturated dendritic hydrocarbon polymer. The process has the following steps: (a) polymerizing an amount of a first alkadiene monomer under anionic conditions in the presence of a first organic monolithium initiator to produce a linear polyalkadiene having a lithiated chain end; (b) reacting the linear polyalkadiene with an amount of a second organic monolithium initiator in the presence of tetramethylethylene diamine to form a multilithiated polyalkadiene; (c) reacting the multilithiated polyalkadiene with an amount of a second alkadiene monomer to form a branched polyalkadiene; (d) repeating steps (b) and (c) with the branched polyalkadiene one or more times to prepare a dendritic polyalkadiene; and (e) hydrogenating the dendritic polyalkadiene to form the substantially saturated dendritic hydrocarbon polymer.

Abstract: Gypsum wallboard can be made lighter and less dense, without sacrificing strength, by adding to the gypsum slurry used in making the board a styrene butadiene polymer latex substantially stable against divalent ions in which the styrene butadiene polymer includes at least 0.25 wt. % of an ionic monomer.

Abstract: [Problem] To provide a conjugated diene polymer cyclized product free from coloring, a conjugated diene polymer cyclized product that has a narrow molecular weight distribution and is free from coloring, and a method for producing these conjugated diene polymer cyclized products. [Means for Resolution] A conjugated diene polymer cyclized product having a Gardner color scale of not more than 3.0. A conjugated diene polymer cyclized product having a Gardner color scale of not more than 3.0 and a ratio of weight average molecular weight/number average molecular weight of not more than 1.5. A method for producing a conjugated diene polymer cyclized product includes adding water to a conjugated diene polymer solution obtained by polymerizing a conjugated diene in a solvent by using an organoalkali metal compound as an initiator, thereby terminating the polymerization and then subjecting the subject conjugated diene polymer to a cyclization reaction.

Abstract: A thermoplastic resin composition for a refrigerator according to the present invention can include (A) about 20 to about 40 parts by weight of an acrylonitrile-butadiene-styrene graft copolymer resin prepared by grafting in emulsion polymerization about 60 to about 30% by weight of a monomer mixture comprising a cyanide vinyl compound and an aromatic vinyl compound to about 40 to about 70% by weight of a rubber polymer having an average particle size of about 0.1 to about 0.4 ?m; (B) about 1 to about 20 parts by weight of a styrenic copolymer comprising (b1) about 0 to about 75% by weight of a styrenic copolymer prepared by copolymerizing about 5 to about 20% by weight of a rubber polymer having an average particle size of about 0.

Abstract: A polymer latex suitable for use in gypsum wallboard or other applications. The polymer latex is a styrene butadiene latex that is substantially stable against divalent ions. The polymer latex includes styrene, butadiene, and an ionic monomer comprised of a 2-acrylamido-2-methyl propanesulfonic acid salt. The polymer latex may also include hydrophilic adjunct comonomers. The latex includes at least 0.25 wt. % of the ionic monomer.

Abstract: The present invention provides solid support media for use in oligomer synthesis, methods of producing the media, and methods of using the media. In some embodiments, the processes of the invention comprise (a) providing an organic phase comprising an olefin monomer, a cross-linker, a functionalizing reagent and an initiator; and (b) contacting the organic phase with an aqueous phase under conditions of time and temperature effective to form the polymeric bead.

Abstract: Aqueous polymer compositions are provided that are suitable as coatings when dry. The coatings formed from such compositions have desirably low level of yellowness, both when new and upon aging. Also provided are methods of making such compositions.

Abstract: The present invention provides solid support media for use in oligomer synthesis, methods of producing the media, and methods of using the media. In some embodiments, the processes of the invention comprise (a) providing an organic phase comprising an olefin monomer, a cross-linker, a functionalizing reagent and an initiator; and (b) contacting the organic phase with an aqueous phase under conditions of time and temperature effective to form the polymeric bead.

Abstract: A conjugated diene rubber gel comprising 80–99 weight % of conjugated diene monomer units and 20–1 weight % of aromatic vinyl monomer units and having a swelling index of 16 to 70 as measured in toluene. A rubber vulcanizate made from a rubber composition comprising this conjugated diene rubber gel and a rubber capable of being crosslinked with sulfur exhibits good abrasion resistance and low heat-build up without deterioration of mechanical properties, and thus, is suitable for tire materials. This conjugated diene rubber gel can be produced with high efficiency by emulsion-polymerization of a monomer mixture comprising 50–99.9 weight % of a conjugated diene monomer, 0–30 weight % of an aromatic vinyl monomer, 0–20 weight % of a crosslinking monomer.

Abstract: The invention relates to a method for preparing butadiene-based aqueous dispersions in the presence of at least one azocarboxylic acid ester.

Abstract: A process for preparing an aqueous styrene-butadiene polymer dispersion by free-radical aqueous emulsion polymerization of a monomer mixture M that comprises styrene, butadiene, and if desired up to 30% by weight, per 100% by weight of monomers, of ethylenically unsaturated comonomers other than styrene and butadiene; by a monomer feed technique that includes supplying to the polymerization reaction a regulator system containing, from 0.02 to 0.4% by weight of terpinolene and from 0.5 to 2% by weight of an organic compound S containing at least one SH group.

Abstract: A conjugated diene rubber gel comprising 80-99 weight % of conjugated diene monomer units and 20-1 weight % of aromatic vinyl monomer units and having a swelling index of 16 to 70 as measured in toluene. A rubber vulcanizate made from a rubber composition comprising this conjugated diene rubber gel and a rubber capable of being crosslinked with sulfur exhibits good abrasion resistance and low heat-build up without deterioration of mechanical properties, and thus, is suitable for tire materials. This conjugated diene rubber gel can be produced with high efficiency by emulsion-polymerization of a monomer mixture comprising 50-99.9 weight % of a conjugated diene monomer, 0-30 weight % of an aromatic vinyl monomer, 0-20 weight % of a crosslinking monomer.

Abstract: The invention relates to a method for producing caoutchouc particles (K) by means of emulsion polymerisation in the presence of an emulsifier and a polymerisation initiator. Said particles contain A) 80 to 100 wt. % of one or more conjugated diene monomers (A) in relation to (K) and B) 0 to 20 wt. % of one or more monoethylenically unsaturated comonomers (B) in relation to (K) in the polymerised form. The inventive method is characterised in that 1) a mixture (M1) containing water and an emulsifier is provided, 2) a mixture (M2) containing one or more monomers in the monomer or polymerised form selected from styrole, &agr;-methylstyrole, butadiene, n-butylacrylate, MMA and acrylnitrile and optionally comonomers is added, 3) polymerisation of the obtained mixture starts in the presence of a polymerisation initiator at temperature of 5 to 95° C., 4) a mixture (M3) containing 0 to 100 wt. % of the comonomers (B) in relation to (B) and 0 to 25 wt.

Abstract: An objective of the invention is to provide a conjugated diene-based rubber having a specific composition and an oil extended rubber using the same, as well as a rubber composition capable of being converted into a vulcanized rubber which has a low rolling resistance, an excellent wearing resistance and the like, and is useful for a tire or the like. A conjugated diene-based rubber in the invention has repeating units consisting of 1 to 30% by mass of an olefinically unsaturated nitrile monomer unit such as acrylonitrile, 10 to 50% by mass of an aromatic vinyl monomer unit such as styrene, 19.9 to 88.9% by mass of a conjugated diene monomer unit such as 1,3-butadiene and 0.1 to 10% by mass of a monomer unit having one polymerizable unsaturated group and at least one functional group selected from the group consisting of an amino group, a hydroxyl group, an epoxy group, a carboxyl group and an alkoxysilyl group, and has a specific glass transition point and a Mooney viscosity [ML1+4(100° C.

Abstract: The invention relates to a method for producing caoutchouc particles (K) by means of emulsion polymerisation in the presence of an emulsifier and a polymerisation initiator. Said particles contain A) 80 to 100 wt. % of one or more conjugated diene monomers (A) in relation to (K) and B) 0 to 20 wt. % of one or more monoethylenically saturated comonomers (B) in relation to (K) in the polymerised form The inventive method is characterised in that 1) a mixture (M1) containing water and an emulsifier is provided, 2) a mixture (M2) containing one or more monomers in the monomer or polymerised form selected from styrole, &agr;-methylstyrole, butadiene, n-butylacrylate, MMA and acrylnitrile and optionally comonomers is added, 3) polymerisation of the obtained mixture starts in the presence of a polymerisation initiator at temperature of 5 to 95° C., 4) a mixture (M3) containing 0 to 100 wt. % of the comonomers (B) in relation to (B) and 0 to 25 wt.

Abstract: A process for production of diene rubber polymers wherein, during production of a diene rubber polymer by emulsion polymerization, the polymerization is initiated using a portion of the starting material and the polymerization is continued with either continuous or intermittent dropwise addition of the remainder of the starting material during the polymerization, and wherein at least ½ of the total amount of the water and of the monomer in the starting material used is added dropwise during the polymerization, and the temperature of the dropwise added water and monomer is kept to at least 20° C. below the polymerization temperature. The process can produce industrially useful diene rubber polymer latexes at a high productivity rate.

Abstract: A process for the reaction of an organic compound in the presence of a catalyst comprising, as active metal, ruthenium alone or together with at least one Group Ib, VIIb, or VIIIb metal in an amount of from 0.01 to 30 wt %, based on the total weight of the catalyst, applied to a support, wherein from 10 to 50% of the pore volume of the support comprises macropores having a pore diameter in the range of from 50 nm to 10,000 nm and from 50 to 90% of the pore volume of the support comprises mesopores having a pore diameter in the range of from 2 to 50 nm, the sum of said pore volumes being 100%, and said catalyst as such.

Abstract: The invention provides functionalized copolymers in the form of their aqueous dispersions or water-redispersible powders, based on