Abstract: Tire rubbers which are prepared by anionic polymerization are frequently coupled with a suitable coupling agent, such as a tin halide, to improve desired properties. It has been unexpectedly found that greatly improved properties for tire rubbers, such as lower hysteresis, can be attained by asymmetrically coupling the rubber.

Abstract: Rubbery polymers made by anionic polymerization can be coupled with tin halides or silicon halides to improve the characteristics of the rubber for use in some applications, such as tire treads. In cases where the rubbery polymer is synthesized by anionic polymerization utilizing a polar modifier it is difficult to attain a high level of coupling.

Abstract: The present invention relates to a tire tread compound that is highly loaded with silica. This compound offers the advantages of silica compounding without the need for solution SBR. More specifically, the tire tread rubber formulations of this invention offer an excellent combination of traction, treadwear and rolling resistance characteristics. The subject invention discloses a tire which is comprised of a generally toroidal-shaped carcass with an outer circumferential tread, two spaced beads, at least one ply extending from bead to bead and sidewalls extending radially from and connecting said tread to said beads; wherein said tread is adapted to be ground-contacting; wherein the tread is comprised of (1) 10 phr to 35 phr of high vinyl polybutadiene rubber having a glass transition temperature which is within the range of −40° C. to 10° C., (2) 65 phr to 90 phr of tin-coupled isoprene-butadiene rubber having a glass transition temperature which is within the range of −90° C.

Abstract: The process and catalyst system of this invention can be utilized to synthesize a highly random styrene-butadiene rubber having a high trans content by solution polymerization. The styrene-butadiene rubber made by the process of this invention can be utilized in tire tread rubbers that exhibit improved wear characteristics. This invention more specifically reveals a catalyst system for use in isothermal polymerizations which consists essentially of (a) an organolithium compound, (b) a calcium alkoxide and (c) a lithium alkoxide. The subject invention further discloses a process for synthesizing a random styrene-butadiene rubber having a low vinyl content by a process which comprises copolymerizing styrene and 1,3-butadiene under isothermal conditions in an organic solvent in the presence of a catalyst system which consists essentially of (a) an organolithium compound, (b) a calcium alkoxide and (c) a lithium alkoxide.

Abstract: This invention discloses a process for making dilithium initiators in high purity. This process can be conducted in the absence of amines which is desirable since amines can act as modifiers for anionic polymerizations. The dilithium compounds made are highly desirable because they are soluble in aromatic solvents. The present invention more specifically discloses a process for synthesizing a dilithium initiator which comprises reacting diisopropenylbenzene with a tertiary alkyl lithium compound in an aromatic solvent at a temperature which is within the range of about 0° C. to about 100° C. The present invention further discloses a process for synthesizing m-di-(1-lithio-1-methyl-3,3-dimethylbutyl)benzene which comprises reacting diisopropenylbenzene with tertiary-butyllithium in an aromatic solvent at a temperature which is within the range of about 0° C. to about 100° C.

Abstract: The process and catalyst system of this invention can be utilized to synthesize a highly random styrene-butadiene rubber having a high trans content by solution polymerization. The styrene-butadiene rubber made by the process of this invention can be utilized in tire tread rubbers that exhibit improved wear characteristics. This invention more specifically reveals a catalyst system for use in isothermal polymerizations which consists essentially of (a) an organolithium compound, (b) a calcium alkoxide and (c) a lithium alkoxide. The subject invention further discloses a process for synthesizing a random styrene-butadiene rubber having a low vinyl content by a process which comprises copolymerizing styrene and 1,3-butadiene under isothermal conditions in an organic solvent in the presence of a catalyst system which consists essentially of (a) an organolithium compound, (b) a calcium alkoxide and (c) a lithium alkoxide.

Abstract: The present invention relates to a tire tread compound that is highly loaded with silica. This compound offers the advantages of silica compounding without the need for solution SBR. More specifically, the tire tread rubber formulations of this invention offer an excellent combination of traction, treadwear and rolling resistance characteristics. The subject invention discloses a tire which is comprised of a generally toroidal-shaped carcass with an outer circumferential tread, two spaced beads, at least one ply extending from bead to bead and sidewalls extending radially from and connecting said tread to said beads; wherein said tread is adapted to be ground-contacting; wherein the tread is comprised of (1) 5 phr to 40 phr of a polyisoprene rubber selected from the group consisting of natural rubber and synthetic polyisoprene, (2) 20 phr to 60 phr of high vinyl polybutadiene rubber having a glass transition temperature which is within the range of −40° C. to 10° C.

Abstract: This invention discloses a process for making dilithium initiators in high purity. This process can be conducted in the absence of amines which is desirable since amines can act as modifiers for anionic polymerizations. The dilithium compounds made are highly desirable because they are soluble in aromatic solvents. The present invention more specifically discloses a process for synthesizing a dilithium initiator which comprises reacting diisopropenylbenzene with a tertiary alkyl lithium compound in an aromatic solvent at a temperature which is within the range of about 0° C. to about 100° C. The present invention further discloses a process for synthesizing m-di-(1-methyl-3,3-dimethylbutyllithio) benzene which comprises reacting diisopropenylbenzene with tertiary-butyllithium in an aromatic solvent at a temperature which is within the range of about 0° C. to about 100° C.

Abstract: It has been unexpectedly found that greatly improved properties for tire rubbers, such as lower hysteresis, can be attained by coupling the rubber with both a tin halide, such as tin tetrachloride, and a silicon halide, such as silicon tetrachloride. Even better characteristics for use in tire tread compounds can be realized by asymmetrically coupling the rubbery polymer. This invention more specifically discloses a coupled rubbery polymer which is particularly valuable for use in manufacturing tire tread compounds, said coupled rubbery polymer being comprised of (1) tin atoms having at least three polydiene arms covalently bonded thereto and (2) silicon atoms having at least three polydiene arms covalently bonded thereto.

Abstract: It has been unexpectedly determined that isoprene-butadiene rubber having a high glass transition temperature within the range of about −40° C. to about −25° C. (high Tg IBR) can be loaded with silica as a filler and utilized in manufacturing tire treads that have outstanding performance characteristics. For instance, such tire treads offer lower hysteresis at high temperatures (improved rolling resistance) and higher hysteresis at low temperatures (improved wet traction characteristics). By utilizing high Tg IBR in tire tread compounds, the maximum benefits of silica compounding can be realized without the need for solution or emulsion styrene-butadiene rubber (SBR) in the tread rubber formulations. The tire tread rubber formulations of this invention will normally contain about 20 phr (parts per 100 parts of rubber) to about 100 phr of the high Tg IBR.

Abstract: This invention discloses a process for making dilithium initiators in high purity. This process can be conducted in the absence of amines which is desirable since amines can act as modifiers for anionic polymerizations. The dilithium compounds made are highly desirable because they are soluble in aromatic solvents. The present invention more specifically discloses a process for synthesizing a dilithium initiator which comprises reacting diisopropenylbenzene with a tertiary alkyl lithium compound in an aromatic solvent at a temperature which is within the range of about 0° C. to about 100° C. The present invention further discloses a process for synthesizing m-di-(1-methyl-3,3-dimethylbutyllithio) benzene which comprises reacting diisopropenylbenzene with tertiary-butyllithium in an aromatic solvent at a temperature which is within the range of about 0° C. to about 100° C.

Abstract: A host signal processor (HSP) modem has a software interface between HSP modem hardware and native audio hardware in a host computer. No hard wire connections between modem hardware and audio hardware are required for synchronization. Instead, a software clock recovery system matches a transfer rate of the HSP modem hardware and a transfer rate of the audio hardware by duplicating or deleting samples. The software interface allows the native audio hardware to make audible the handshaking sequence during modem connections which eliminates the need for a speaker and speaker drivers in the modem hardware. The combination of HSP modem hardware, audio hardware, and software executed by the host computer also allows the HSP modem to perform voice communication such as telephone or speakerphone functions.

Abstract: Cold flow is a problem that is commonly encountered in the handling and storage of low molecular weight linear rubbers, such as low vinyl polybutadiene rubber and isoprene-butadiene rubber. This invention is based upon the unexpected discovery that the cold flow of such rubbery polymers can be greatly reduced by incorporating a small block of polystyrene therein. The rubbery polymers of this invention which exhibit a low level of cold flow can be synthesized by simply terpolymerizing 1,3-butadiene, isoprene and from about 0.5 phm to about 3 phm of styrene under anionic polymerization conditions in the absence of a polar modifier. It is preferred to utilize batch .polymerization techniques. However, continuous polymerization techniques can also be utilized. This invention more specifically disclosed a rubbery polymer which is comprised of polymer chains containing repeat units which are derived from 1,3-butadiene, isoprene and from about 0.

Abstract: Cold flow is a problem that is commonly encountered in the handling and storage of low molecular weight linear rubbers, such as low vinyl polybutadiene rubber and isoprene-butadiene rubber. This invention is based upon the unexpected discovery that the cold flow of such rubbery polymers can be greatly reduced by incorporating a small block of polystyrene therein. The rubbery polymers of this invention which exhibit a low level of cold flow can be synthesized by simply terpolymerizing 1,3-butadiene, isoprene and from about 0.5 phm to about 3 phm of styrene under anionic polymerization conditions in the absence of a polar modifier. It is preferred to utilize batch polymerization techniques. However, continuous polymerization techniques can also be utilized. This invention more specifically disclosed a rubbery polymer which is comprised of polymer chains containing repeat units which are derived from 1,3-butadiene, isoprene and from about 0.

Abstract: Tire rubbers which are prepared by anionic polymerization are frequently coupled with a suitable coupling agent, such as a tin halide, to improve desired properties. It has been unexpectedly found that greatly improved properties for tire rubbers, such as lower hysteresis, can be attained by asymmetrically coupling the rubber.

Abstract: A host signal processor (HSP) modem has a software interface between HSP modem hardware and native audio hardware in a host computer. No hard wire connections between modem hardware and audio hardware are required for synchronization. Instead, a software clock recovery system matches a transfer rate of the HSP modem hardware and a transfer rate of the audio hardware by duplicating or deleting samples. The software interface allows the native audio hardware to make audible the handshaking sequence during modem connections which eliminates the need for a speaker and speaker drivers in the modem hardware. The combination of HSP modem hardware, audio hardware, and software executed by the host computer also allows the HSP modem to perform voice communication such as telephone or speakerphone functions.

Abstract: The process of this invention can be utilized to stabilize tin-coupled rubbery polymers. This process involves adding a chelating diamine or a sodium alkoxide to the rubbery polymer after the tin coupling has been carried out. This invention more specifically discloses a process for improving the stability of a tin-coupled rubbery polymer which comprises adding a sodium alkoxide to the tin-coupled rubbery polymer subsequent to the time at which the tin-coupled rubbery polymer is coupled. Sodium alkoxide is a representative example of a sodium alkoxide that can be used to stabilize the tin-coupled rubbery polymer.

Abstract: The subject invention discloses a liquid isoprene-butadiene rubber (IBR) which is particularly valuable for use in making treads for high performance automobile tires, including race tires, that exhibit superior dry traction characteristics and durability. The isoprene-butadiene rubber of this invention is a liquid at room temperature and is comprised of repeat units which are derived from about 5 weight percent to about 95 weight percent isoprene and from about 5 weight percent to about 95 weight percent 1,3-butadiene, wherein the repeat units derived from isoprene and 1,3-butadiene are in essentially random order. The IBR of this invention also has a low number average molecular weight which is within the range of about 3,000 to about 50,000 and has a glass transition temperature which is within the range of about −50° C. to about 20° C.

Abstract: The subject invention discloses a liquid isoprene-butadiene rubber (IBR) which is particularly valuable for use in making treads for high performance automobile tires, including race tires, that exhibit superior dry traction characteristics and durability. The isoprene-butadiene rubber of this invention is a liquid at room temperature and is comprised of repeat units which are derived from about 5 weight percent to about 95 weight percent isoprene and from about 5 weight percent to about 95 weight percent 1,3-butadiene, wherein the repeat units derived from isoprene and 1,3-butadiene are in essentially random order. The IBR of this invention also has a low number average molecular weight which is within the range of about 3,000 to about 50,000 and has a glass transition temperature which is within the range of about −50° C. to about 20° C.

Abstract: The process of this invention can be utilized to stabilize tin-coupled rubbery polymers. This process involves adding a chelating diamine or a metal salt of a cyclic alcohol to the rubbery polymer after the tin coupling has been carried out. This invention more specifically discloses a process for improving the stability of a tin-coupled rubbery polymer which comprises adding a metal salt of a cyclic alcohol to the tin-coupled rubbery polymer subsequent to the time at which the tin-coupled rubbery polymer is coupled. The use of metal salts of cyclic alcohols does not lead to recycle stream contamination because they do not co-distill with hexane or form compounds during steam-stripping which co-distill with hexane. In other words, the boiling points of these metal salts of cyclic alcohols are very high, so they do not co-distill with hexane and contaminate recycle streams. Additionally, metal salts of cyclic alcohols are considered to be environmentally safe.