Abstract: An article comprises a laminate with a layer comprising a first latex composition containing a cross-linker component selected from sulfur, organic peroxide, vulcanizing activators, and vulcanizing accelerator; and a second layer comprising a second latex composition free of the cross-linker component. The laminate is formed by dipping a mold into the first latex composition then into the second latex composition forming a laminated film, then curing the laminated film by heating to a temperature between 90° C. to 140° C. Lastly, the laminated film is removed from the mold via inversion such that the second layer is inwards and the first layer is outwards.

Abstract: Branched block copolymers, derived from alkenyl aromatic hydrocarbon-1,3-diene monomer system, and branched polyisoprene homopolymers, derived from isoprene, are obtained by polymerization in the presence of an anionic initiator; at a temperature from 0° C. to 100° C.; followed by coupling with a multifunctional coupling agent of formula (R1O)3Si—Y—Si(OR2)3, wherein R1 and R2 are independently C1-C6 alkyl groups; and Y is a C2-C8 alkylene group. The polymers thus obtained can be used in many applications, including rubber cements having high solids content and low zero shear viscosities, and for producing aqueous latices therefrom.

Abstract: Branched block copolymers, derived from alkenyl aromatic hydrocarbon-1,3-diene monomer system, and branched polyisoprene homopolymers, derived from isoprene, are obtained by polymerization in the presence of an anionic initiator; at a temperature from 0° C. to 100° C.; followed by coupling with a multifunctional coupling agent of formula (R1O)3Si—Y—Si(OR2)3, wherein R1 and R2 are independently C1-C6 alkyl groups; and Y is a C2-C8 alkylene group. The polymers thus obtained can be used in many applications, including rubber cements having high solids content and low zero shear viscosities, and for producing aqueous latices therefrom.

Abstract: The disclosure relates to rubber latex formed from any of: branched block copolymers derived from alkenyl aromatic hydrocarbon—1,3-diene monomer system, and branched polyisoprene homopolymers derived from isoprene. The polymers in embodiments are obtained by polymerization in the presence of an anionic initiator; at a temperature from 0° C. to 100° C.; followed by coupling with a multifunctional coupling agent of formula (R1O)3Si—Y—Si(OR2)3, wherein R1 and R2 are independently C1-C6 alkyl groups; and Y is a C2-C8 alkylene group. The polymers are obtained as rubber cements having high solids content and low zero shear viscosities. The rubber cements are valuable for making latices for further applications.

Abstract: Dipped formed latex articles with improved properties are formed from branched block copolymers, derived from alkenyl aromatic hydrocarbon—1,3-diene monomer system, and branched polyisoprene homopolymers, derived from isoprene. The polymers are obtained by polymerization in the presence of an anionic initiator; at a temperature from 0° C. to 100° C.; followed by coupling with a multifunctional coupling agent of formula (R1O)3Si—Y—Si(OR2)3, wherein R1 and R2 are independently C1-C6 alkyl groups; and Y is a C2-C8 alkylene group. The polymers are obtained as rubber cements having high solids content and low zero shear viscosities. The rubber cements are valuable for making latices and latex articles such as dipped goods, e.g., condoms, gloves, etc., with improved properties.

Abstract: An article comprises a laminate with a layer comprising a first latex composition containing a cross-linker component selected from sulfur, organic peroxide, vulcanizing activators, and vulcanizing accelerator; and a second layer comprising a second latex composition free of the cross-linker component. The laminate is formed by dipping a mold into the first latex composition then into the second latex composition forming a laminated film, then curing the laminated film by heating to a temperature between 90° C. to 140° C. Lastly, the laminated film is removed from the mold via inversion such that the second layer is inwards and the first layer is outwards.

Abstract: The invention concerns an olefinically unsaturated radial styrenic block copolymer having the general formula A-B—Y—(B-A)n wherein each A is independently a polymer block composed of at least 90 mol. % of an alkenyl aromatic hydrocarbon, each B is independently a polymer block composed of at least 90 mol. % of one or more conjugated dienes, Y is the remnant of a coupling agent, and n is an integer from 2 to 5. The invention is also an improved vulcanizer-free latex comprising water and the olefinically unsaturated radial styrenic block copolymer. Moreover, the invention concerns a process for preparing articles by coagulation dipping from the improved latex and dipped goods made from such latex.

Abstract: A method for the curing of aqueous latexes comprising block copolymers is disclosed. The block copolymers have the general formula A-B-A or A-B-Y-(B-A)n. The curing is conducted using vulcanization systems that are free of guanidine and thiuram compounds. The cured latexes are useful in the manufacture of elastic films, surgical, examination and electrical insulation gloves, industrial gloves and condoms.

Abstract: Articles with enhanced tensile strength and comfort are prepared from a latex comprising water and a styrenic block copolymer, wherein the styrenic block copolymer has 2 or more poly(vinyl aromatic) blocks and at least one block of polymerized conjugated diene, wherein the styrenic block copolymer has a weight average molecular weight of 150,000 to 250,000, the poly(vinyl aromatic) blocks have a weight average molecular weight ranging from 9,000 to 15,000, and the content of poly(vinylaromatic) blocks in the styrenic block copolymer ranges from 8 to 15% wt, based on the total styrenic block copolymer, by a process which comprises coating a surface with the latex to obtain a film, wherein the latex comprises a vulcanizing agent. The invention also provides a latex comprising such a styrenic block copolymer and a vulcanizing agent, as well as a styrenic block copolymer that is particularly suitable for use in such a latex.

Abstract: The invention concerns an olefinically unsaturated radial styrenic block copolymer having the general formula A-B—Y—(B-A)n wherein each A is independently a polymer block composed of at least 90 mol. % of an alkenyl aromatic hydrocarbon, each B is independently a polymer block composed of at least 90 mol. % of one or more conjugated dienes, Y is the remnant of a coupling agent, and n is an integer from 2 to 5. The invention is also an improved vulcanizer-free latex comprising water and the olefinically unsaturated radial styrenic block copolymer. Moreover, the invention concerns a process for preparing articles by coagulation dipping from the improved latex and dipped goods made from such latex.

Abstract: Articles with enhanced tensile strength and comfort are prepared from a latex comprising water and a styrenic block copolymer, wherein the styrenic block copolymer has 2 or more poly(vinyl aromatic) blocks and at least one block of polymerized conjugated diene wherein the styrenic block copolymer has a weight average molecular weight of 150,000 to 250,000, the poly(vinyl aromatic) blocks have a weight average molecular weight ranging from 9,000 to 15,000, and the content of poly(vinylaromatic) blocks in the styrenic block copolymer ranges from 8 to 15% wt, based on the total styrenic block copolymer, by a process which comprises coating a surface with the latex to obtain a film, wherein the latex comprises a vulcanising agent. The invention also provides a latex comprising such a styrenic block copolymer and a vulcanising agent, as well as a styrenic block copolymer that is particularly suitable for use in such a latex.

Abstract: A process of producing an artificial latex, comprising the steps: (a) cement formation, wherein a rubber is dissolved in a suitable hydrocarbon solvent; (b) emulsification of the cement formed in step (a), together with an aqueous soap solution, thus forming an oil-in-water emulsion; (c) hydrocarbon solvent removal, resulting in a latex of the rubber having particles of a median particle size in the range of from about 0.5 to 2.0 ?m, and optionally (d) latex concentration, forming an artificial latex with a higher solids content, characterized in that in step (b) a premix is formed first, which is subsequently homogenized into an oil-in-water emulsion, and wherein the premix is formed by mixing the cement with the aqueous soap solution at a volume ratio of 1:1.

Abstract: A process of producing an artificial latex, comprising the steps: (a) cement formation, wherein a rubber is dissolved in a suitable hydrocarbon solvent; (b) emulsification of the cement formed in step (a), together with an aqueous soap solution, thus forming an oil-in-water emulsion; (c) hydrocarbon solvent removal, resulting in a latex of the rubber having particles of a median particle size in the range of from about 0.5 to 2.0 ?m, and optionally (d) latex concentration, forming an artificial latex with a higher solids content, characterized in that in step (b) a premix is formed first, which is subsequently homogenized into an oil-in-water emulsion, and wherein the premix is formed by mixing the cement with the aqueous soap solution at a volume ratio of 1:1.

Abstract: Disclosed is a method for making selectively hydrogenated block copolymers of vinyl aromatic hydrocarbons and conjugated dienes comprising: a) anionically polymerizing vinyl aromatic hydrocarbons and conjugated dienes to produce block copolymers with living chain ends; b) terminating the living chain ends; to produce a terminated block copolymer, with a member from the group consisting of an alcohol, hydrogen, and mixtures thereof, to prepare a terminated block copolymer; and c) contacting the terminated block copolymers with hydrogen at a temperature of from 20 to 175° C. in the presence of a catalyst prepared by combining a cobalt carboxylate with an aluminum alkyl, wherein: (i) if the polymer is terminated with an alcohol and the alcohol is a linear alcohol, the linear alcohol is used to terminate the living chain ends in an amount such that the alcohol:living chain end molar ratio is from 0.05 to 1.

Abstract: The present invention relates to a process for preparing a partially hydrogenated butadiene polymer comprising no more than 3 mol % 1,2-butadiene-recurring units (A) and no more than 3 mol % ethylene recurring units (D), calculated on the total content mol/mol of recurring units, wherein a butadiene polymer comprising 1,2-butadiene recurring units (A) and 1,4-butadiene recurring units (B) is hydrogenated in the presence of hydrogen and a titanium-, zirconium- and/or hafnium-based metallocene compound as hydrogenation catalyst and a cocatalyst, characterized in that: a) the hydrogenation catalyst has a reaction rate ratio of r1/r2 greater than 5, wherein r1 and r2 are the hydrogenation rates of recurring units (A) and (B) respectively at the same reaction conditions, b) the cocatalyst is an alkali metal hydride, added as such or prepared in situ, and c) hydrogenation of the conjugated diene is carried out until at least 97% of recurring units (A) have been hydrogenated.

Abstract: The present invention concerns a bituminous composition which comprises a bituminous component (I), a block copolymer (II), comprising at least two terminal blocks of a poly(monovinylaromatic hydrocarbon) and at least one block of a poly(conjugated diene), and optionally a filler (III), wherein (II) is a partially hydrogenated block polymer, comprising butadiene as the conjugated diene, wherein the poly(conjugated diene) block upon partial hydrogenation comprises less than 3 mol % 1,2-dine recurring units (A) and less than 20 mol % preferably less than 3 mol % ethylene recurring units (D), calculated on the total content mol/mol of conjugated diene recurring units.

Abstract: The present invention concerns a bituminous composition which comprises a bituminous component (I), a block copolymer (II), comprising at least two terminal blocks of a poly(monovinylaromatic hydrocarbon) and at least one block of a poly(conjugated diene), and optionally a filler (III), wherein (II) is a partially hydrogenated block polymer, comprising butadiene as the conjugated diene, wherein the poly(conjugated diene) block upon partial hydrogenation comprises less than 3 mol % 1,2-dine recurring units (A) and less than 20 mol % preferably less than 3 mol % ethylene recurring units (D), calculated on the total content mol/mol of conjugated diene recurring units.

Abstract: Disclosed is a method for making selectively hydrogenated block copolymers of vinyl aromatic hydrocarbons and conjugated dienes comprising: a) anionically polymerizing vinyl aromatic hydrocarbons and conjugated dienes to produce block copolymers with living chain ends; b) terminating the living chain ends; to produce a terminated block copolymer, with a member from the group consisting of an alcohol, hydrogen, and mixtures thereof, to prepare a terminated block copolymer; and c) contacting the terminated block copolymers with hydrogen at a temperature of from 20 to 175° C. in the presence of a catalyst prepared by combining a cobalt carboxylate with an aluminum alkyl, wherein: (i) if the polymer is terminated with an alcohol and the alcohol is a linear alcohol, the linear alcohol is used to terminate the living chain ends in an amount such that the alcohol: living chain end molar ratio is from 0.05 to 1.

Abstract: The present invention relates to a process for preparing a partially hydrogenated butadiene polymer comprising no more than 3 mol % 1,2-butadiene recurring units (A) and no more than 3 mol % ethylene recurring units (D), calculated on the total content mol/mol of recurring units, wherein a butadiene polymer comprising 1,2-butadiene recurring units (A) and 1,4-butadiene recurring units (B) is hydrogenated in the presence of hydrogen and a titanium, zirconium- and/or hafnium-based metallocene compound as hydrogenation catalyst and a cocatalyst, characterized in that: a) the hydrogenation catalyst has a reaction rate ratio of r1/r2 greater than 5, wherein r1 and r2 are the hydrogenation rates of recurring units (A) and (B) respectively at the same reaction conditions, b) the cocatalyst is an alkali metal hydride, added as such of prepared in situ, and c) hydrogenation of the conjugated diene is carried out until at least 97 % of recurring units (A) have been hydrogenated.

Abstract: The invention provides a catalyst composition for hydrogenation of polymers containing ethylenical unsaturation which comprises at least:(a) a titanium compound of the formula ##STR1## (I) wherein A.sub.1 represents an optionally substituted indenyl group of the formula ##STR2## wherein substituents R.sub.1 and R.sub.2 may be the same or different and each may be selected from halogen, phenyl which optionally may bear one or more the same or different substituents, lower alkyl, alkoxy, phenoxy, phenylalkoxy, benzyl, and a bulky substituent containing one or more hetero atoms such as tri (loweralkyl)silyl, --NPh.sub.2, --NHPh, --BPh.sub.2, and --B(OPh).sub.2, wherein n may be an integer of from 0 to 4 and m may be an integer of from 0 to 3,(II)wherein A.sub.2 has the same meaning as A.sub.1 or alternatively represents an optionally substituted cyclopentadienyl group, and wherein L.sub.1 and L.sub.