Abstract: The invention provides a catalyst composition suitable for hydrogenation of polymers containing ethylenic unsaturation, which comprise:(a) a titanium compound of the formula, ##STR1## wherein A.sub.1 and A.sub.2 are the same or different and each represents a substituted or unsubstituted cyclopentadienyl or indenyl group,wherein X.sub.1 and X.sub.2 are the same or different and each represents hydrogen, halogen, a lower alkyl or lower alkoxy, optionally substituted phenyl or phenoxy, or aralkyl having from 7 to 10 carbon atoms, or phenylalkoxy having from 7 to 10 carbon atoms, carboxyl, carbonyl, a --CH.sub.2 P(Phenyl).sub.2, --CH.sub.2 Si(lower alkyl).sub.3, or --P(phenyl).sub.2 group.(b) an alkalimetal hydride, added as such or prepared in situ in the polymer solution from the alkalimetal terminated living polymer and/or from additionally added alkalimetal alkyl and hydrogen, the molar ratio of the alkalimetal:titanium in the polymer solution during hydrogenation being at least 2:1;(c) a borium compoundB(R.

Abstract: The invention relates to the selective hydrogenation of unsaturated polymers, in particular elastomeric polymers which contain aromatic rings and carbon-carbon double rings, for example polymers prepared from styrene and butadiene. In this case, the polymer molecule contains internal and terminal-group double bonds, as well as unsaturated bonds in aromatic rings. According to the invention, only the unsaturated terminal and internal bonds are hydrogenated, whereby the thermal and weather resistance properties of the product are improved. Conventionally, hydrogenation has been performed by means of nickel or cobalt catalysts, but now it has been observed that a metallocene/alumoxane catalyst complex not only catalyzes the polymerization reaction of various olefinic compounds but also catalyzes the selective hydrogenation of unsaturated polymers, preferably styrene-butadiene-styrene block polymers.

Abstract: A saturated polymer having a terminal aldehyde or hydroxy substituent which may be used directly or in a derivative form as a dispersant for both fuel and lubricating oil compositions, wherein the saturated polymer has a M.sub.n of about 300 to 10,000, and is derived from a polyolefin which is derived from a monomer of the formula H.sub.2 C=CHR.sup.4, wherein R.sup.4 is hydrogen or a straight or branched chain alkyl radical, and wherein the polyolefin has at least about 30% terminal vinylidene unsaturation. Particularly desirable amine derivatives can be formed by either a single step aminomethylation process or a two step hydroformylation and reductive amination process.

Abstract: This invention provides sealant compositions which comprise a hydrogenated styrene-butadiene-styrene (SEBS) block copolymer which has an overall weight average molecular weight of from 30,000 to 300,000, a styrene block weight average molecular weight of from 4000 to 35,000, and a vinyl content of at least 45% by weight (% wt), preferably 45 to 90%, and an adhesion promoting resin. For every 100 parts by weight of copolymer, there should be at least 20 parts of adhesion promoting resin.

Abstract: There is provided a method for selectively hydrogenating living polymers having olefinic double bonds, in which the living polymers resulting from the polymerization initiated by alkyllithium compound are deactivated by contacting the polymerization terminators for a short time under a mild condition and hydrogenated in the presence of bis(cyclopentadienyl)titanium compound in high efficiency and high reproducibility without adjusting accurate molar ratio of the lithium compound to the titanium compound.

Abstract: The present invention provides a process for selective hydrogenation of a conjugated diene polymer. The process includes bringing the conjugated diene polymer in an inert organic solvent into contact with hydrogen in the presence of a specific hydrogenation catalyst combination including (A) a substituted or unsubstituted bis(cyclopentadienyl) Group VIII transition metal compound and (B) an organic lithium compound. The hydrogenation can be carried out in the presence of a small amount of the hydrogenation catalyst combination under mild conditions, and both the hydrogenation conversion and selectivity to conjugated diene units are high.

Abstract: A continuous process for the solution polymerization of appropriate polycycloolefins in a ROMP zone to obtain a processable ROMP homo- or copolymer in solution, and subsequent hydrogenation of the ROMP (co)polymer without removing the residual ROMP catalyst and co-catalyst, provides an optical product having a mol wt M.sub.w in the range from 50,000-300,000 and polydispersity M.sub.w /M.sub.n in the range from 1.3-5.0, more preferably from 1.3-3, the lower the polydispersity the more desirable the physical properties of the (co)polymer.

Abstract: The invention comprises a hydrogenated hydrocarbon resin suitable as tackifier for acrylic adhesive polymers, having greater than 20% aromatic protons after hydrogenation, a z-average molecular weight of less than about 1800, a narrow molecular weight distribution, typically of less than or equal to 2.1, and a softening point of from 40.degree. C. to about 120.degree. C. It additionally comprises a method for preparing a hydrogenated aromatic tackifier resin suitable as tackifier for acrylic adhesive polymers comprising the steps of: a) polymerizing under Friedel-Crafts polymerization conditions steam-cracked petroleum distillates, or fractions thereof; having boiling points between about 135.degree. C. and 220.degree. C. and containing at least 40% of by weight vinyl aromatic monomer contents, in the presence of a chain transfer agent; and b) catalytically hydrogenating the results of a) such that at least 75% of the aromaticity is retained.

Abstract: A saturated polymer having a terminal aldehyde or hydroxy substituent which may be used directly or in a derivative form as a dispersant for both fuel and lubricating oil compositions, wherein the saturated polymer has a M.sub.n of about 300 to 10,000, and is derived from a polyolefin which is derived from a monomer of the formula H.sub.2 C.dbd.CHR.sup.4, wherein R.sup.4 is hydrogen or a straight or branched chain alkyl radical, and wherein the polyolefin has at least about 30% terminal vinylidene unsaturation. Particularly desirable amine derivatives can be formed by either a single step aminomethylation process or a two step hydroformylation and reductive amination process.

Abstract: A resin obtained by subjecting a norbornene type monomer having an aromatic ring structure (e.g. 5-phenyl-2-norbornene) to ring-opening polymerization and hydrogenating 95% or more of the unsaturated bonds in the backbone structure of the resulting polymer by the use of a catalyst composed of a combination of a transition metal compound and an alkyl metal compound, while leaving 80% or more of the aromatic ring structures, which resin has not only a high refractive index but also characteristics of a hydrogenated norbornene ring-opening polymerization product, i.e., excellent heat resistance, transparency, low birefringent properties, weather resistance, light resistance, low water absorption properties, moisture resistance, small dielectric constant, small dielectric loss, chemical resistance, etc., said resin being usable in optical materials, medical tools and materials, tools and materials for treating electronic parts, etc.

Abstract: The invention comprises a hydrogenated hydrocarbon resin suitable as tackifier for acrylic adhesive polymers, having greater than 20% aromatic protons after hydrogenation, a z-average molecular weight of less than about 1800, a narrow molecular weight distribution, typically of less than or equal to 2.1, and a softening point of from 40.degree. C. to about 120.degree. C. It additionally comprises a method for preparing a hydrogenated aromatic tackifier resin suitable as tackifier for acrylic adhesive polymers comprising the steps of: a) polymerizing under Friedel-Crafts polymerization conditions stem-cracked petroleum distillates, or fractions thereof, having boiling points between about 135.degree. C. and 220.degree. C. and containing at least 40% of by weight vinyl aromatic monomer contents, in the presence of a chain transfer agent; and b) catalytically hydrogenating the results of a) such that at least 75% of the aromaticity is retained.

Abstract: A nitrile group-containing highly saturated copolymer rubber which is a product obtained by hydrogenating the conjugated diene portion of an unsaturated nitrile-conjugated diene copolymer. The highly saturated copolymer rubber has an alkylthio group having 12 to 16 carbon atoms, which include at least three tertiary carbon atoms, and having a sulfur atom which is directly bound to at least one of the tertiary carbon atom, and the highly saturated copolymer rubber further has a Mooney viscosity of 15 to 200 and an iodine value not larger than 80. The highly saturated copolymer rubber is produced copolymerizing an unsaturated nitrile, a conjugated diene and an optional copolymerizable monomer by using as a molecular weight modifier an alkylthiol compound having 12 to 16 carbon atoms, which include at least three tertiary carbon atoms, and having a sulfur atom which is directly bound to at least one of the tertiary carbon atoms; and then, hydrogenating the thus-obtained copolymer.

Abstract: The present invention is a process of hydrogenating high molecular weight aromatic polymers comprising hydrogenating the high molecular weight aromatic polymer in the presence of a silica supported metal hydrogenation catalyst, characterized in that the silica has a pore size distribution such that at least 98 percent of the pore volume is defined by pores having diameter of greater than 600 angstroms.

Abstract: The present invention discloses a polycyclic norbornene-based ring-opening polymer which comprises(A) 90-5% by mol of a repeating unit represented by the following formula [I] or the alkyl-substituted derivative thereof, and(B) 10-95% by mol of at least one repeating unit selected from a repeating unit represented by the following formula [II], the alkyl-substituted derivative thereof, a repeating unit represented by the following formula [III], the alkyl-substituted derivative thereof, or the alkylidene-substituted derivative thereof, and which has an intrinsic viscosity [.eta.] of 0.01-20 dl/g as determined in toluene at 25.degree. C., the hydrogenation products thereof, and a process for production thereof ##STR1## wherein ------ denotes a single bond or a double bond.

Abstract: This invention relates to functionalized polymers and a method to obtain them comprising combing a living polymer or a polymer having a terminal halide with an alkylsilylpseudohalide.

Abstract: Tackifiers having Mn's of 5,000 or less and Tg's above 0.degree. C. are produced by combining a single site catalyst with an alpha-olefin and a cyclic monomer under conditions designed to produce low molecular weight.

Abstract: Propylene polymers have a molecular weight ratio Q (M.sub.w /M.sub.n) of from 6 to 30 and are obtainable by Ziegler-Natta polymerization in the presence of hydrogen as molecular weight regulator and are particularly suitable for the production of films and moldings.

Abstract: Radiation-sensitive polymeric adducts of (1) a sulfonated polyester resin having a plurality of sulfonate groups, (2) a diazonium resin having a plurality of diazonium groups, and (3) a salt of quaternary ammonium or quaternary phosphonium. This invention also provides a radiation-sensitive article comprising a substrate bearing a coating containing a radiation-sensitive adduct.

Abstract: Polymers Ia and Ib carrying functional groups and obtainable byA)1. hydrogenation of the olefinic double bonds of a polymer IIa comprisinga) from 20 to 100% by weight of a conjugated diene,b) from 0 to 80% by weight of an aromatic vinyl compound, andc) from 0 to 20% by weight of further comonomers,to give the hydrogenated polymer IIb,2. metallation of IIb using an organoalkali metal compound to give IIc,3. reaction of IIc with a diaziridine III to give IId, and4. hydrolysis or alcoholysis of IId to give Ia, or byB)1. partial hydrogenation of IIa to give a partially hydrogenated polymer IIb',2. epoxidation of the double bonds of IIb' to give IIe, and3. reaction of IIe with a compound IV carrying functional groups, to give Ib,are suitable as viscosity index improvers for engine oils.

Abstract: A description follows of epoxydated block copolymers, either linear or branched, which can be defined with the following formulae:1) [A--(E--B--EPOX)].sub.n X2) A.sub.1 --(E.sub.1 --B.sub.1 --EPOX.sub.1)--A--HT--(E.sub.2 --B.sub.2 --EPOX.sub.2)3) [(E.sub.1 --B.sub.1 --EPOX.sub.1)--HT--A(E.sub.2 --B.sub.2 --EPOX.sub.2)].sub.x Xwhere A is a polyvinylaromatic block in a percentage ranging from 10 to 50% by weight, E--B--EPOX is a block composed of ethylene units, epoxydated butene and diene units in which the percentage by weight of the epoxy group ranges from 1% to 40%, HT is a tapered copolymer segment made up of hydrogenated and epoxydated diene monomeric units and vinylaromatic units whose content ranges from 0 to 20%, x is a radical having a valence ranging from 1 to 20.The block copolymers have an average molecular weight ranging from 30,000 to 400,000, a content of polyvinylaromatic blocks of between 10 and 50% by weight and a content of (E.sub.1 --B.sub.1 --EPOX.sub.1)+(E.sub.2 --B.sub.2 --EPOX.sub.

Abstract: The present invention provides the hydrogenated product of a thermoplastic norbornene polymer excellent in characteristics as optical materials by reducing the residual amounts of the transition metal atoms originating from the polymerization catalyst used at the polymerization to 1 ppm or less of the hydrogenated product.Reduction of the residual amounts to below the desired level is attained by treating the reaction solution with the adsorbent during or after production of the hydrogenated product from the thermoplastic norbornene polymer.The hydrogenated product of the thermoplastic norbornene polymer thus obtained in which the residual amounts of the transition metal atoms are 1 ppm or less, has a wide utilization field, including a material for optical articles having excellent utilization characteristics such as substrates for optical elements, lenses and the like.

Abstract: A description follows of epoxydated block copolymers, either linear or branched, which can be defined with the following formulae:1) [A-(E-B-EPOX)].sub.n X2) A.sub.1 -(E.sub.1 -B.sub.1 -EPOX.sub.1)-A-HT-(E.sub.2 -B.sub.2 -EPOX.sub.2)3) [(E.sub.1 -B.sub.1 -EPOX.sub.1)-HT-A(E.sub.2 -B.sub.2 -EPOX.sub.2)].sub.n Xwhere A is a polyvinylaromatic block in a percentage ranging from 10 to 50% by weight, E-B-EPOX is a block composed of ethylene units, epoxydated butene and diene units in which the percentage by weight of the epoxy group ranges from 1% to 40%, HT is a tapered copolymer segment made up of hydrogenated and epoxydated diene monomeric units and vinylaromatic units whose content ranges from 0 to 20%, x is a radical having a valence ranging from 1 to 20.The block copolymers have an average molecular weight ranging from 30,000 to 400,000, a content of polyvinylaromatic blocks of between 10 and 50% by weight and a content of (E.sub.1 -B.sub.1 -EPOX.sub.1)+(E.sub.2 -B.sub.2 -EPOX.sub.

Abstract: It has now been discovered that the hydrogenation of unsaturated homo and copolymers can be effectively carried out in the absence of added gaseous hydrogen by contacting the unsaturated polymer with a hydrogen donor compound in the presence of a Group VIII metal catalyst, especially a supported palladium catalyst, for a time and at a temperature sufficient to bring about the hydrogenation of the unsaturated polymer.

Abstract: A method for hydrogenating unsaturated low molecular weight polymers, preferably polydiene monool, diol and polyol polymers, which comprises contacting the polymers under hydrogenation conditions with hydrogen in the presence of a fixed bed heterogeneous catalyst which is comprised of platinum, palladium or a mixture of the two supported on an alpha alumina support.

Abstract: A process for producing partially hydrogenated diene pollers containing unsaturation in the endo and exo configurations while substantially eliminating the unsaturation in the 1,4-trans configuration, by isomerizing the unsaturation during hydrogenation in the presence of an arylphosphine isomerizing agent.

Abstract: A process for partially isomerized partially hydrogenated diene polishers containing unsaturation in endo and exo trisubstituted chain configurations while substantially eliminating the unsaturation in the 1,4-trans configuration remaining after hydrogenation, by isomerizing the unsaturation in the presence of a phosphine, borane, or alkali alkoxide isomerizing agent.

Abstract: This invention relates to a method for hydrogenation of poly(alkenyl aromatic) polymers or poly(alkenyl aromatic)/polydiene block copolymers that provides hydrogenated polymers with 99.5% or greater unsaturation and an MWD of less than about 3. Hydrogenated polymers and adhesives comprising the hydrogenated polymers and tackifier are also provided.

Abstract: A process for producing isomerized partially hydrogenated diene polymers containing unsaturation in endo and exo trisubstituted chain configurations while substantially eliminating the unsaturation in the 1,4-trans configuration remaining after hydrogenation, by isomerizing the unsaturation in the presence of a phosphine, borane, or alkali alkoxide isomerizing agent.

Abstract: A process for producing partially hydrogenated diene polymers containing unsaturation in the endo and exo configurations while substantially eliminating the unsaturation in the 1,4-trans configuration, by isomerizing the unsaturation during hydrogenation in the presence of an arylphosphine isomerizing agent.

Abstract: This invention relates to a process for minimizing or reducing the amount of residual free hydrazine in polymer latices. The process is particularly useful in the manufacture of hydrogenated nitrile rubber which is resistant to oxidative degradation at high temperatures, as well as resistant to corrosive environments such as acid environments. Nitrile rubbers are useful in the manufacture of fan belts, seals, gaskets, and hoses in increasingly small and hot-running car engines.

Abstract: A method is provided for hydrovisbreaking hydrocarbon polymers, particularly those derived from scrap articles, in which a mixture of at least one hydrocarbon polymer and a solvent is contacted with hydrogen under conditions sufficient to hydrovisbreak the polymer. The solvent comprises a combined weight percentage of C.sub.n H.sub.2n-8 and C.sub.n H.sub.2n-10 hydrocarbons of at least about 10 weight percent, where n is an integer of at least 8 in C.sub.n H.sub.2n-8 and n is an integer of at least 10 in C.sub.n H.sub.2n-10. The hydrovisbroken polymer can be fed to a catalytic cracker for cracking to cracked products.

Abstract: A process for preparing a resin having a low iodine value, comprising treating a resin having a residual unsaturated bond with a cationic polymerization catalyst. According to the process, a resin in which residual unsaturated bonds are decreased can be prepared, and the obtained resin having a low iodine value can be suitably used as raw materials for flame retarders, adhesives and the like.

Abstract: The present invention is an improvement upon a process for hydrogenating a diene polymer by contacting the polymer in the presence of hydrogen with a titanium hydrogenation catalyst. The improvement comprises preventing discoloration of the hydrogenated polymer by treating it with water, a peroxide or alcohol in the absence of oxygen and adding a non-phenolic antioxidant to the polymer.

Abstract: In a first embodiment of the present invention, poisoning or deactivation of conventional homogeneous catalysts to be used in hydrogenation of the backbone unsaturation in liquid monofunctional and difunctional-terminated conjugated diene polymers, is prevented by reacting a blocking agent compound with the functional end groups present in these polymers. More specifically, subsequent to formation of a selected starting material monofunctional or difunctional-terminated conjugated diene polymer, a suitable blocking agent is reacted with the functional end groups of the polymer enabling relatively inexpensive titanium, iron, cobalt, or nickel-based homogeneous catalysts to be used in hydrogenating the backbone unsaturation of the polymer to a high degree. Subsequent to hydrogenation, the polymer is subjected to conventional hydrolysis using a mineral acid or base to remove the blocking groups and return the hydrogenated conjugated diene polymer to its original functionality.

Abstract: The present invention is an improvement upon a process for hydrogenating a diene polymer by contacting the polymer in the presence of hydrogen with a titanium hydrogenation catalyst. The improvement comprises preventing discoloration of the hydrogenated polymer by treating it with water, a peroxide or alcohol in the absence of oxygen and adding a non-phenolic antioxidant to the polymer.

Abstract: Disclosed herein is a process for the selective hydrogenation of the carbon-carbon double bonds of an unsaturated, nitrile-group-containing polymer with hydrogen in the presence of a hydrogenation catalyst. An aqueous emulsion of the unsaturated, nitrile-group-containing polymer is used. Optionally, an organic solvent capable of dissolving or swelling the polymer is caused to exist at a volume ratio of the aqueous emulsion to the organic solvent in a range of from 1:3 to 1:0. A palladium compound is used as the hydrogenation catalyst. The aqueous emulsion is brought into contact with gaseous or dissolved hydrogen while maintaining an emulsified state.

Abstract: Poisoning or deactivation of conventional homogeneous catalysts to be used in hydrogenation of the backbone unsaturation in liquid monofunctional and difunctional-terminated conjugated diene polymers, is prevented by reacting a blocking agent compound with the functional end groups present in these polymers. More specifically, subsequent to formation of a selected starting material monofunctional or difunctional-terminated conjugated diene polymer, a suitable blocking agent is reacted with the functional end groups of the polymer enabling relatively inexpensive titanium, iron, cobalt, or nickel-based homogeneous catalysts to be used in hydrogenating the backbone unsaturation of the polymer to a high degree. Subsequent to hydrogenation, the polymer is subjected to conventional hydrolysis using a mineral acid or base to remove the blocking groups and return the hydrogenated conjugated diene polymer to its original functionality.

Abstract: A process for making polymers of conjugated dienes which contain hydroxyl groups, including highly reactive primary hydroxyl groups, in the diene blocks which comprises(a) making a precursor polymer by polymerizing at least one conjugated diene which leaves 1,2 disubstituted, 1,1 disubstituted, 1,1,2 trisubstituted or tetrasubstituted olefinic unsaturation in the polymer,(b) optionally partially hydrogenating said precursor polymer,(c) epoxidizing said precursor polymer such that epoxy groups form at said substituted sites and the amount of epoxy functionality in the polymer is from at least 0.1 Meq/g polymer, and(d) reacting the epoxidized polymer with an alcohol having one unprotected hydroxyl group in a solvent in the presence of a Lewis acid selected from the group consisting of MX.sub.n where M is selected from the group consisting of boron, aluminum, iron and tin, and X is a halogen, and organic complexes of such acids.A diene polymer containing 0.

Abstract: A process for making polymers of conjugated dienes which contain hydroxyl groups, including highly reactive primary hydroxyl groups, in the diene blocks which comprises(a) making a precursor polymer by polymerizing at least one conjugated diene which leaves 1,2 disubstituted, 1,1 disubstituted, 1,1,2 trisubstituted or tetrasubstituted olefinic unsaturation in the polymer,(b) optionally partially hydrogenating said precursor polymer,(c) epoxidizing said precursor polymer such that epoxy groups form at said substituted sites and the amount of epoxy functionality in the polymer is from at least 0.1 Meq/g polymer, and(d) reacting the epoxidized polymer with an alcohol having one unprotected hydroxyl group in a solvent in the presence of a Lewis acid selected from the group consisting of MX.sub.n where M is selected from the group consisting of boron, aluminum, iron and tin, and X is a halogen, and organic complexes of such acids.A diene polymer containing 0.

Abstract: An improved process is provided for the catalytic hydrogenation of nitrile rubber in solution in an organic medium using a ruthenium catalyst, the improvement being that the hydrogenation is undertaken in the presence of water and a selected organic additive whereby the molecular weight increase in the hydrogenation process is minimized and controlled.

Abstract: The present invention provides a process to remove phosphine residues from a hydrogenated polymer solution.

Abstract: This is a process for the hydrogenation of conjugated diolefin polymers which comprises polymerizing or copolymerizing at least one conjugated diolefin with an organo alkali metal polymerization initiator in a suitable solvent thereby creating a living polymer, terminating the polymerization by the addition of hydrogen and effecting selective hydrogenation of the unsaturated double bonds in the conjugated diolefin units of the terminated polymer by contacting the polymer with hydrogen in the presence of an organo alkali metal promoter and Tebbe's reagent.

Abstract: This is a process for the partial hydrogenation of conjugated diolefin polymers which comprises polymerizing at least one conjugated diolefin with an organo alkali metal polymerization initiator in a suitable solvent thereby creating a living polymer comprising (1) ethylenic unsaturation between backbone carbons wherein at least one of the doubly bound backbone carbons is substituted and (2) ethylenic unsaturation which is not between doubly bound backbone carbons wherein at least one is substituted, terminating the polymerization, and effecting selective hydrogenation of the ethylenic unsaturation in the conjugated diolefin units of the terminated polymer which is not between doubly bound backbone carbons wherein at least one is substituted, by contacting the polymer with hydrogen in the presence of no more than 0.02 mM of catalyst per gram of polymer of a bis(cyclopentadienyl)titanium catalyst.

Abstract: An improved process is provided for the catalytic hydrogenation of nitrile rubber in solution in an organic medium using a ruthenium catalyst, the improvement being that the hydrogenation is undertaken in the presence of water and a selected inorganic additive whereby the molecular weight increase in the hydrogenation process is minimized and controlled.

Abstract: High-temperature oil-resistant elastomers are prepared from butadiene alkenylpyridine copolymers, butadiene-acrylate copolymers, and copolymers of butadiene with 1,3-dienes containing fluorine. The unsaturated olefinic backbone and pendant unsaturation derived from the hydrocarbon diene of each of the copolymers is hydrogenated to a high degree by a catalyst which improves the heat resistance of the copolymer without hydrogenation of the polar groups thereof which would lower the oil-resistance of the copolymer. A complexing agent for the hydrogenation catalyst prevents poisoning of the catalyst by the polar groups of the copolymers thereby enabling the catalyst to complex with unsaturated sites along the olefinic copolymer backbone to achieve high levels of hydrogenation thereof.

Abstract: An improved process is provided for the catalytic hydrogenation of nitrile rubber using a ruthenium catalyst wherein the improvement is that the nitrile rubber is provided as an aqueous emulsion and a solvent and a selected inorganic additive are present during the hydrogenation, whereby the molecular weight increase in the hydrogenation process is minimized and controlled.

Abstract: An improved process is provided for the catalytic hydrogenation of nitrile rubber using a ruthenium catalyst wherein the improvement is that the nitrile rubber is provided as an aqueous emulsion and a solvent and a selected organic additive are present during the hydrogenation, whereby the molecular weight increase in the hydrogenation process is minimized and controlled.

Abstract: Substantially optically clear molding compositions comprising polymerized cycloolefin monomers (e.g., norbornene-type polymers) which, subsequent to polymerization have been hydrogenated are provided. The polymers have a weight average molecular weight of from about 37-47.times.10.sup.3.

Abstract: This is an improved process for the hydrogenation of conjugated diolefin polymers which comprises polymerizing or copolymerizing at least one conjugated diolefin with an organo alkali metal polymerization initiator in a suitable solvent thereby creating a living polymer, terminating the polymerization by the addition of hydrogen and effecting selective hydrogenation of the unsaturated double bonds in the conjugated diolefin units of the terminated polymer by contacting the polymer, in the absence of hydrocarbon lithium and alkoxy lithium compounds, with hydrogen in the presence of at least one bis(cyclopentadienyl)titanium compound. The improvement is the use of an alkyl benzoate as a promoter in the hydrogenation step.

Abstract: A process for producing a hydrogenation product of ring-opening polymer by hydrogenating, in the presence of a hydrogenation catalyst, the non-aromatic carbon-to-carbon double bond present in a ring-opening polymer obtained by subjecting to ring-opening polymerization at least one norbornene derivative represented by general formula (I): ##STR1## wherein A and B independently represent hydrogen atoms or hydrocarbon groups having 1-10 carbon atoms, X and Y independently represent hydrogen atoms, halogen atoms or monovalent organic groups, and m is 0 or 1, alone or in combination with a monomer copolymerizable with said norbronene derivative, characterized by using, as the hydrogenation catalyst, a ruthenium compound represented by general formula (II):RuH.sub.k Q.sub.n T.sub.p Z.sub.q (11)wherein Q represents a halogen atom, T represents at least one atomic group selected from the group consisting of CO, NO and CH.sub.3 COCH.sub.2 COCH.sub.3, Z represents PR.sup.1 R.sup.2 R.sup.3 (R.sup.1, R.sub.2 and R.sup.