摘要:
By utilizing the vapor phase polymerization techniques of the present invention, numerous distinct and highly beneficial advantages are realized. For instance, cis-1,4-polyisoprene rubber and high cis-1,4-polybutadiene rubber having a consistent and controllable molecular weight can be easily and practically prepared without utilizing a solvent. The subject invention more specifically discloses a method for vapor phase polymerizing isoprene into cis-1,4-polyisoprene in a process comprising the steps of:(1) charging into a reaction zone said isoprene and a preformed catalyst system which is made by reacting an organoaluminum compound with titanium tetrachloride, preferably in the presence of at least one ether; wherein the isoprene is maintained in the vapor phase in said reaction zone by a suitable combination of temperature and pressure;(2) allowing said isoprene to polymerize into cis-1,4-polyisoprene at a temperature within the range of about 35.degree. C. to about 70.degree. C.; and(3) withdrawing said cis-1,4-polyisoprene from said reaction zone. It has been determined that gel formation can be reduced by conducting the polymerization of isoprene monomer in the presence of a diarylamine, such as para-styrenated diphenylamine.
摘要:
By utilizing the techniques of this invention, trans-1,4-polybutadiene can be synthesized continuously to a high level of conversion utilizing a low level of a highly active cobalt-based catalyst system. The trans-1,4-polybutadiene made with the cobalt-based catalyst system of this invention also typically has a molecular weight which is acceptable for use in tire applications without the need for employing a molecular weight regulator. It is also not typically necessary to utilize a gel inhibitor, such as carbon disulfide, in the polymerizations of this invention. Since a low level of residual cobalt is present in the trans-1,4-polybutadiene which is made utilizing the catalyst system of this invention, it is much more stable than trans-1,4-polybutadiene made with standard cobalt-based catalyst systems. This invention specifically relates to a process for synthesizing trans-1,4-polybutadiene by polymerizing 1,3-butadiene monomer in the presence of a catalyst system which is comprised of cobalt (III) acetylacetonate, an organoaluminum compound and a para-alkyl-substituted phenol, wherein the cobalt (III) acetylacetonate is mixed with the para-substituted phenol prior to the polymerization. Such polymerizations can be conducted on a batch or a continuous basis.
摘要:
It has been determined that 1,3-butadiene monomer can be polymerized into cis-l,4-polybutadiene rubber utilizing a cobalt-based catalyst system which is comprised of (a) an organocobalt compound, (b) a trialkylaluminum compound and (c) hexafluoro-2-propanol. The use of this catalyst system results in extremely fast rates of polymerization. The molecular weight of the cis-1,4- polybutadiene rubber made utilizing this cobalt-based catalyst system can be regulated by conducting the polymerization in the presence of 1,5-cyclooctadiene. This present invention more specifically discloses a catalyst system which is particularly useful for polymerizing 1,3-butadiene monomer into cis-1,4-polybutadiene, said catalyst system being comprised of (a) an organocobalt compound, (b) a trialkylaluminum compound and (c) hexafluoro-2-propanol. The subject invention further discloses a process for synthesizing cis-1,4-polybutadiene rubber which comprises polymerizing 1,3-butadiene in the presence of (a) an organocobalt compound, (b) a trialkylaluminum compound and (c) hexafluoro-2-propanol.
摘要:
This invention is based upon the unexpected discovery that elastomeric trans-1,4-polybutadiene can be made by utilizing a catalyst system that is comprised of an organocobalt compound, an organoaluminum compound, a para-alkyl substituted phenol, and ortho-phenyl phenol wherein the molar ratio of the para-substituted phenol to the organoaluminum compound is within the range of about 1.2:1 to about 1.8:1, and wherein the molar ratio of the ortho-phenyl phenol to the organoaluminum compound is within the range of about 0.7:1 to about 1.3:1. Accordingly, the elastomeric trans-1,4-polybutadiene made by the process of this invention does not need to be heated, such as in a hot-house, before being used in making rubber stocks.
摘要:
By utilizing the vapor phase polymerization techniques of the present invention, numerous distinct and highly beneficial advantages are realized. For instance, cis-1,4-polyisoprene rubber and high cis-1,4-polybutadiene rubber having a consistent and controllable molecular weight can be easily and practically prepared without utilizing a solvent. The subject invention more specifically discloses a method for vapor phase polymerizing isoprene into cis-1,4-polyisoprene in a process comprising the steps of:(1) charging into a reaction zone said isoprene and a preformed catalyst system which is made by reacting an organoaluminum compound with titanium tetrachloride, preferably in the presence of at least one ether; wherein the isoprene is maintained in the vapor phase in said reaction zone by a suitable combination of temperature and pressure;(2) allowing said isoprene to polymerize into cis-1,4-polyisoprene at a temperature within the range of about 35.degree. C. to about 70.degree. C.; and(3) withdrawing said cis-1,4-polyisoprene from said reaction zone. It has been determined that gel formation can be reduced by conducting the polymerization of isoprene monomer in the presence of a diarylamine, such as para-styrenated diphenylamine.
摘要:
It has been unexpectedly discovered that cis-1,4-polybutadiene that is synthesized utilizing Zeigler-Natta catalyst systems has superior characteristics for utilization in solid golf ball cores if the polymerization is terminated utilizing a carboxylic acid of the structural formula RCOOH, wherein R represents an alkyl group containing from 1 to about 30 carbon atoms.
摘要:
The synthesis of cis-1,4-polyisoprene by polymerizing isoprene with a catalyst system which is comprised of a titanium tetrahalide, a trialkylaluminum compound and diphenylether is plagued with the formation of gel. This invention is based upon the unexpected discovery that gel formation can be reduced by conducting such polymerizations in the presence of a diarylamine, such as para-styrenated diphenylamine. The subject invention more specifically discloses a process for synthesizing cis-1,4-polyisoprene having a low gel content which comprises polymerizing isoprene in an inert organic solvent with a preformed catalyst system which is made by reacting an organoaluminum compound with titanium tetrahalide, such as titanium tetrachloride, in the presence of at least one ether, wherein said polymerization is conducted at a temperature which is within the range of about 0.degree. C. to about 100.degree. C., and wherein said polymerization is conducted in the presence of a diarylamine.
摘要:
By utilizing the vapor phase polymerization techniques of the present invention, numerous distinct and highly beneficial advantages are realized. For instance, cis-1,4-polyisoprene rubber and high cis-1,4-polybutadiene rubber having a consistent and controllable molecular weight can be easily and practically prepared without utilizing a solvent. The subject invention more specifically discloses a method for vapor phase polymerizing isoprene into cis-1,4-polyisoprene in a process comprising the steps of:(1) charging into a reaction zone said isoprene and a preformed catalyst system which is made by reacting an organoaluminum compound with titanium tetrachloride, preferably in the presence of at least one ether; wherein the isoprene is maintained in the vapor phase in said reaction zone by a suitable combination of temperature and pressure;(2) allowing said isoprene to polymerize into cis-1,4-polyisoprene in said reaction zone at a temperature within the range of about 0.degree. C. to about 100.degree. C. in the presence of a diarylamine, wherein said reaction zone is a horizontal, stirred reactor of substantially circular cross section containing a centrally-located drive shaft extending longitudinally through said reactor to which are attached a plurality of adjacently located paddles, which paddles cause essentially no forward or backward movement of the cis-1,4-polyisoprene contained in said reactor; and(3) withdrawing said cis-1,4-polyisoprene from said reaction zone.
摘要:
This invention is based upon the unexpected discovery that elastomeric trans-1,4-polybutadiene can be made by utilizing a catalyst system that is comprised of an organocobalt compound, an organoaluminum compound, a para-alkyl substituted phenol, and ortho-phenyl phenol wherein the molar ratio of the para-substituted phenol to the organoaluminum compound is within the range of about 1.2:1 to about 1.8:1, and wherein the molar ratio of the ortho-phenyl phenol to the organoaluminum compound is within the range of about 0.7:1 to about 1.3:1. Accordingly, the elastomeric trans-1,4-polybutadiene made by the process of this invention does not need to be heated, such as in a hot-house, before being used in making rubber stocks. This invention more specifically discloses a process for synthesizing elastomeric trans-1-4-polybutadiene by polymerizing 1,3-butadiene monomer in the presence of a catalyst system that is comprised of an organocobalt compound, an organoaluminum compound, a para-alkyl substituted phenol, and ortho-phenyl phenol, wherein the molar ratio of the para-substituted phenol to the organoaluminum compound is within the range of about 1.2:1 to about 1.8:1, and wherein the molar ratio of the ortho-phenyl phenol to the organoaluminum compound is within the range of about 0.7:1 to about 1.3:1.
摘要:
Syndiotactic 1,2-polybutadiene is a thermoplastic resin which has double bonds attached in an alternating fashion to its polymeric backbone. Films, fibers and molded articles can be made utilizing syndiotactic 1,2-polybutadiene. It can also be blended into rubbers and cocured therewith. It is generally preferred to synthesize syndiotactic 1,2-polybutadiene in an aqueous medium by suspension or emulsion polymerization utilizing a cobalt-based catalyst system. This invention is based upon the unexpected finding that certain substituted benzoic acids can be employed to deactivate such cobalt based catalyst systems. This invention more specifically discloses a process for synthesizing and deactivating syndiotactic 1,2-polybutadiene which comprises (1) polymerizing 1,3-butadiene monomer in the aqueous medium in the presence of a catalyst system which is comprised of (a) transition metal compound, (b) an organoaluminum compound and (c) at least one member selected from the group consisting of carbon disulfide, phenyl isothiocyanate and xanthic acid to produce an aqueous medium which contains the syndiotactic 1,2-polybutadiene; and (2) subsequently adding a substituted benzoic acid to the aqueous medium which contains the syndiotactic 1,2-polybutadiene to deactivate the catalyst system.