Patents by Inventor Ramesh Krishnamurti
Ramesh Krishnamurti has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6258910Abstract: Disclosed is a method of polymerizing vinyl chloride or vinylidene chloride monomer. A mixture is prepared of (1) a monomer selected from the group consisting of vinyl chloride, vinylidene chloride, and mixtures thereof with up to about 20 wt % of a comonomer, (2) supercritical carbon dioxide, subcritical carbon dioxide, or liquid carbon dioxide in a weight ratio to the monomer of about 0.5 to about 5; and (3) about 0.1 to about 1 phr of a free radical initiator that is soluble in said supercritical carbon dioxide or a solution of said a free radical initiator in a solvent that is miscible with the carbon dioxide. The mixture is heated to a temperature of about 40 to about 70° C. to polymerize the monomer.Type: GrantFiled: June 9, 1999Date of Patent: July 10, 2001Assignee: Occidental Chemical CorporationInventors: Habib Hichri, Ramesh Krishnamurti, Thomas Smolka
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Patent number: 6232260Abstract: A single-site olefin polymerization catalyst and method of making it are disclosed. The catalyst comprises an activator and an organometallic complex. The complex comprises a Group 3 to 10 transition or lanthanide metal, M, and at least one indenoindolyl ligand that is &pgr;-bonded to M. The key ligand is made in two steps from readily available indanones and aryl hydrazines. Reaction of its anion with a source of the metal completes a remarkably simple synthetic route to a new family of single-site olefin polymerization catalysts.Type: GrantFiled: October 14, 1999Date of Patent: May 15, 2001Assignee: Equistar Chemicals, L.P.Inventors: Sandor Nagy, Bradley P. Etherton, Ramesh Krishnamurti, John A. Tyrell
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Patent number: 6228958Abstract: Disclosed is a catalyst having the general formula where L is a ligand having the formula L′ is L, Cp, Cp*, indenyl, fluorenyl, NR2, OR, or halogen, L can be bridged to L; X is halogen, NR2, OR, or alkyl from C1 to C12, M is zirconium or hafnium, R is alkyl from C1 to C12 or aryl from C6 to C12, R1 is R, alkaryl from C6 to C12, aralkyl from C6 to C12, hydrogen, or Si(R)3, R2 is R1, halogen, COR, COOR, SOR, or SOOR, R3 is R2, OR, N(R)2, SR, or a fused ring system, Cp is cyclopentadienyl, Cp* is pentamethylcyclopentadienyl, n is 0 to 3, and LB is an optional Lewis base. Also disclosed is a method of making a poly-&agr;-olefin comprising polymerizing an &agr;-olefin monomer using a catalyst such as that described above where M can be titanium, zirconium, or hafnium.Type: GrantFiled: April 27, 1999Date of Patent: May 8, 2001Assignee: Equistar Chemicals, L.P.Inventors: Sandor Nagy, Ramesh Krishnamurti, Bradley P. Etherton
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Patent number: 6204216Abstract: A single-site olefin polymerization catalyst is described. The catalyst comprises an activator and an organometallic compound that includes an amine derivative ligand. The catalyst is highly productive, incorporates comonomers well, and gives polymers with narrow molecular weight distributions. The compound is of the formula wherein M is a group 3-10 metal; A is O, S, N—R″ or P—R″; L is cyclopentadienyl, boraaryl, pyrrolyl, azaboralinyl, quinolinyl, or pyridinyl, or is another RR′N—A− or RR′C═N—A′ group; X is a hydride, halide, alkoxy, siloxy, hydrocarbyl or amido; R,R′ and R″ are hydrogen or hydrocarbyl; m+n equals the valence of M minus 1.Type: GrantFiled: April 15, 1999Date of Patent: March 20, 2001Assignee: Equistar Chemicals, L.P.Inventors: Sandor Nagy, Bradley P. Etherton, Ramesh Krishnamurti, John A. Tyrell
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Patent number: 6121181Abstract: Single site nitrogen and oxygen metallacyclic catalysts comprising at least two polymerization-stable anionic ancillary ligands and a Group 4-10 metal are disclosed wherein the nitrogen or oxygen heterocyclic catalyst is produced by dimerizing an alkylamido or trimerizing a metal containing oxane. The polymerization-stable anionic ancillary ligands are preferably either cyclopentadienyl, borataaryl, pyrrolyl, azaboralinyl, pyridinyl, or a quinolinyl ring. In a preferred embodiment, the invention relates to catalysts of the formula: ##STR1## wherein M is a transition metal of Groups 3-10;L is a polymerization-stable anionic ancillary ligand;R is a hydrocarbyl group containing up to about 12 carbon atoms optionally substituted with halogen; andE is R or halogen, alkoxy from C.sub.1 to C.sub.20, siloxy from C.sub.1 to C.sub.20, N(R).sub.2, hydrogen or another univalent anionic ligand, or mixtures thereof.Type: GrantFiled: August 7, 1998Date of Patent: September 19, 2000Assignee: Equistar Chemicals, L.P.Inventors: Bradley P. Etherton, Ramesh Krishnamurti, Sandor Nagy
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Patent number: 6114476Abstract: Disclosed is a method of inhibiting the formation of scale on reactor surfaces in contact with a polymerizing vinyl monomer comprising contacting said monomer with a terpolymer which comprises the condensation reaction product of(A) an aromatic compound that contains the group ##STR1## where Q is OR or SR and R is hydrogen, alkyl from C.sub.1 to C.sub.15, or aryl, alkaryl, or aralkyl from C.sub.6 to C.sub.15 :(B) about 0.1 to about 10 moles of a carbonyl compound per mole of said aromatic compound; and(C) about 0.1 to about 10 moles of a thiourea per mole of said aromatic compound.Type: GrantFiled: August 10, 1998Date of Patent: September 5, 2000Assignee: Occidental Chemical CorporationInventors: Ramesh Krishnamurti, Sandor Nagy, Qi Wang, Habib Hichri
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Patent number: 6114270Abstract: Single-site catalyst systems containing alkylimido ligands are disclosed. The catalyst systems comprise a co-catalyst and a Group 3-10 transition metal catalyst. The catalyst includes an alkyl- or arylimido ligand and a polymerization-stable, anionic ligand selected from boraaryl, pyrrolyl, and azaborolinyl. When used to polymerize olefins, the catalyst systems are highly productive, give good comonomer incorporation, and give polymers with narrow molecular weight distributions.Type: GrantFiled: August 7, 1998Date of Patent: September 5, 2000Assignee: Equistar Chemicals, L.P.Inventors: Ramesh Krishnamurti, Sandor Nagy, John Tyrell, Bradley P. Etherton
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Patent number: 6034027Abstract: Disclosed is a catalyst having the general formula ##STR1## where Q is a ligand containing the ring ##STR2## R is hydrogen, N(R').sub.2, OR', or R', each R' is independently selected from alkyl from C.sub.1 to C.sub.10, aryl from C.sub.6 to C.sub.15, alkaryl C.sub.7 to C.sub.15, and aralkyl from C.sub.7 to C.sub.15, each X is independently selected from hydrogen, halogen, alkoxy from C.sub.1 to C.sub.10, dialkylamino from C.sub.1 to C.sub.10, methyl, ##STR3## each R.sub.1 is independently selected from halogen, alkoxy from C.sub.1 to C.sub.10, and R', L is ##STR4## Q, or X, where one .pi.-ligand can be bridged to second .pi.-ligand, B is an optional base, "n" is 0 to 5, and M is a Group 3-10 metal.Type: GrantFiled: June 10, 1997Date of Patent: March 7, 2000Assignee: Equistar Chemicals, LPInventors: Ramesh Krishnamurti, Sandor Nagy, Bradley P. Etherton
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Patent number: 6025407Abstract: Disclosed is a process for polymerizing vinyl chloride monomer in the presence of light. A mixture is formed of liquid vinyl chloride monomer, preferably about 10 to about 250 ppm of a metallocene catalyst, about 1 to about 2000 moles of an aluminum-containing cocatalyst per mole of catalyst, and up to about 500 moles of a Lewis base per mole of aluminum in the cocatalyst. Selected alkyl groups from the aluminum-containing cocatalyst can be placed on the ends of the poly (vinyl chloride) chains.Type: GrantFiled: October 30, 1997Date of Patent: February 15, 2000Assignee: Occidental Chemical CorporationInventors: Sandor M. Nagy, Ramesh Krishnamurti, Mary K. Cocoman, Walter M. Opalinski, Thomas F. Smolka
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Patent number: 6001937Abstract: Disclosed is a method of inhibiting the formation of scale on reactor surfaces in contact with a polymerizing vinyl monomer. The reactor surfaces are contacted with a composition that contains, as a scale reducing agent, an acidic hydrazone condensate or a salt thereof. The scale reducing agent can be added to the polymerizing monomer or it can be placed in a composition containing a surfactant and an inorganic binder and the composition can be applied to the reactor surfaces or added to the monomer.Type: GrantFiled: November 17, 1998Date of Patent: December 14, 1999Assignee: Occidental Chemical CorporationInventors: Ramesh Krishnamurti, Sandor M. Nagy, Habib Hichri, Thomas F. Smolka
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Patent number: 5914408Abstract: A novel metallocene catalyst for the polymerization of olefin (co)polymers is of the general formula:Benzothiazole--E--M--X.sub.m L.sub.nwhere,M is a transition metal of Groups 3-10 of the Periodic Table;E is sulfur or oxygen; E being bond to the transition metal and to the carbon atom between sulfur and nitrogen of the benzothiazole moiety;L is a polymerization-stable anionic ancillary ligand;X is a halogen, alkoxy from C.sub.1 to C.sub.20, siloxy from C.sub.1 to C.sub.20, N(R.sub.1).sub.2, a hydrocarbyl group containing up to about 12 carbon atoms or hydrogen or mixtures thereof; preferably X is halogen, methoxy, ethoxy or siloxy (R.sub.1).sub.3 SiO--, where R.sub.1 is alkyl from C.sub.1 to C.sub.20 ; andm+n equals the valency of the M minus 1.Type: GrantFiled: August 7, 1998Date of Patent: June 22, 1999Assignee: Equistar Chemicals, LPInventors: Ramesh Krishnamurti, Sandor Nagy, John Tyrell, Bradley P. Etherton
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Patent number: 5902866Abstract: Disclosed is a catalyst having the general formula ##STR1## where L is a ligand having the formula ##STR2## L' is L, Cp, Cp*, indenyle fluorenyl, NR.sub.2, OR, or halogen, L can be bridged to L; X is halogen, NR.sub.2, OR, or alkyl from C.sub.1 to C.sub.12, M is zirconium or hafnium, R is alkyl from C.sub.1 to C.sub.12 or aryl from C.sub.6 to C.sub.12, R.sub.1 is R, alkaryl from C.sub.6 to C.sub.12, aralkyl from C.sub.6 to C.sub.12, hydrogen, or Si(R).sub.3, R.sub.2 is R.sub.1, halogen, COR, COOR, SOR, or SOOR, R.sub.3 is R.sub.2, OR, N(R).sub.2, SR, or a fused ring system, Cp is cyclopentadienyl, Cp* is pentamethylcyclopentadienyl, n is 0 to 3, and L.sub.B is an optional Lewis base. Also disclosed is a method of making a poly-.alpha.-olefin comprising polymerizing an .alpha.-olefin monomer using a catalyst such as that described above where M can be titanium, zirconium, or hafnium.Type: GrantFiled: November 13, 1996Date of Patent: May 11, 1999Assignee: Equistar Chemicals, L.P.Inventors: Sandor Nagy, Ramesh Krishnamurti, Bradley P. Etherton
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Patent number: 5872290Abstract: Disclosed is a method of making an acid chloride having the general formula ##STR1## where each R contains no unsaturated groups and is preferably independently selected from aliphatic from C.sub.1 to C.sub.7 and aryl from C.sub.6 to C.sub.15. A solution is formed in an inert solvent of an aldehyde having the general formula ##STR2## and chlorine gas is sparged into said solution. The reaction between the aldehyde and the chlorine gas to produce the acid chloride is performed in the absence of a catalyst, an initiator, and ultraviolet light. A chlorinated acid chloride can be prepared from the acid chloride by reacting it with additional chlorine in the presence of a chlorine free radical generator.Type: GrantFiled: November 7, 1997Date of Patent: February 16, 1999Assignee: Occidental Chemical CorporationInventors: James G. Colson, Ramesh Krishnamurti, Rose Adinolfe
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Patent number: 5817835Abstract: Novel benzothioxepanone and benzothioxepane thione compounds are characterized by the formula ##STR1## wherein Z is: ##STR2## R is Cl, Br, F, C.sub.1 to C.sub.8 alkyl, or C.sub.1 to C.sub.8 alkoxy; X and Y are each hydrogen, or taken together form a fused cyclopentyl or cyclohexyl ring, with the proviso that when Z is ?1!, X and Y represent a fused cyclopentyl or cyclohexyl ring; and n is 0, 1, or 2. The compounds are useful as co-catalysts in the para-directed nuclear chlorination of toluene.Type: GrantFiled: October 22, 1997Date of Patent: October 6, 1998Assignee: Occidental Chemical CorporationInventors: Ramesh Krishnamurti, Sandor Nagy, Thomas F. Smolka
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Patent number: 5756611Abstract: A catalyst useful in the polymerization of .alpha.-olefins comprises the reaction product of an alcohol having the general formula ##STR1## with an organometallic compound having the general formulaLM(X).sub.v-1wherein Q is --COR.sup.12, --CR"R"(OR.sup.12) and --CR"R"N(R").sub.2 ;wherein each R" is independently selected from H and R, R is a C.sub.1 to C.sub.12 alkyl group or a C.sub.6 to C.sub.24 aryl group, R.sup.12 is R or a radical of the formula --(CH.sub.2).sub.w --O--(CH.sub.2).sub.y H, w and y being independently selected from 1 to 4;L is a .pi.-bonded ligand selected from (i.) a cyclopentadienyl or substituted cyclopentadienyl ring; (ii.) a boraaryl ring; (iii) a 1,2-azaborolinyl ring; or (iv.) a 5-membered heterocyclic ring;M is a Group 3 to 7 metal of the Periodic Table;v is the valence of M; andeach X is independently selected from halogen or a C.sub.1 -C.sub.6 alkyl group or a C.sub.6 -C.sub.24 aryl group.Type: GrantFiled: February 21, 1997Date of Patent: May 26, 1998Assignee: Lyondell Petrochemical CompanyInventors: Bradley P. Etherton, Ramesh Krishnamurti, John A. Tyrell, Sandor Nagy
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Patent number: 5750811Abstract: Disclosed is a method of making m-chlorobenzotrifluoride. Benzotrifluoride is reacted with chlorine gas in the presence of about 0.1 to about 5 mole % (based on benzotrifluoride) of a metal chloride which can be FeCl.sub.3, SbCl.sub.3, or AlCl.sub.3 and about 0.025 to about 5.0 mole % (based on benzotrifluoride) of a catalyst having the formula ##STR1## where Z is halogen, alkyl from C.sub.1 to C.sub.6, alkoxy from C.sub.1 to C.sub.6, or fluoroalkyl from C.sub.1 to C.sub.6, n is 0 to 5, and the molar ratio of metal chloride to cocatalyst is about 0.5 to about 4.Type: GrantFiled: April 7, 1997Date of Patent: May 12, 1998Assignee: Occidental Chemical CorporationInventors: Robert A. Buchanan, Ramesh Krishnamurti, Habib Hichri, David C. Johnson
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Patent number: 5714603Abstract: A process for the pare-directed nuclear chlorination of an alkylbenzene, such as toluene, comprises reacting the alkylbenzene with chlorine in the presence of a Lewis acid catalyst and a novel co-catalyst of the formula: ##STR1## where Z is ##STR2## and R is Cl, Br, F, C.sub.1 to C.sub.8 alkyl to C.sub.1 to C.sub.8 alkoxy; x and y are each hydrogen, or taken together form a fused cyclopentyl or cyclohexyl ring; n is 0, 1 or 2, with the proviso that when Z is ?3!, n is 0 or 1.Type: GrantFiled: December 2, 1996Date of Patent: February 3, 1998Assignee: Occidental Chemical CorporationInventors: Ramesh Krishnamurti, Sandor Nagy, Thomas F. Smolka
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Patent number: 5710355Abstract: Disclosed is a method of making a chlorobenzene having the general formulas ##STR1## where X is Cl or F, and X' is X or CF.sub.3. A compound having the formula ##STR2## is sulfonated using at least 2 moles per mole of said compound of a sulfonating agent selected from the group consisting of sulfuric acid, chlorosulfonic acid, and mixtures thereof, to produce a sulfonated compound. The sulfonated compound is chlorodesulfonated to produce a chlorobenzene, such as 1,2,4-trichlorobenzene. Preferably, the starting material is ortho-dichlorobenzene.Type: GrantFiled: June 10, 1996Date of Patent: January 20, 1998Assignee: Occidental Chemical CorporationInventor: Ramesh Krishnamurti
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Patent number: 5637659Abstract: Disclosed is a catalyst having the general formula ##STR1## where Q is a ligand containing the ring ##STR2## R is hydrogen, N(R').sub.2, OR', or R', each R' is independently selected from alkyl from C.sub.1 to C.sub.10, aryl from C.sub.6 to C.sub.15, alkaryl C.sub.7 to C.sub.15, and aralkyl from C.sub.7 to C.sub.15, each X is independently selected from hydrogen, halogen, alkoxy from C.sub.1 to C.sub.10.sub., dialkylamino from C.sub.1 to C.sub.10, methyl, ##STR3## each R.sub.1 is independently selected from halogen, alkoxy from C.sub.1 to C.sub.10, and R', L is ##STR4## Q, or X, where L can be bridged to Q, B is an optional base, "n" is 0 to 5, and M is titanium, zirconium, or hafnium.Type: GrantFiled: May 17, 1996Date of Patent: June 10, 1997Assignee: Lyondell Petrochemical CompanyInventors: Ramesh Krishnamurti, Sandor Nagy, Bradley P. Etherton
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Patent number: 5637660Abstract: Disclosed is a novel bidentate pyridine transition metal catalyst having the general formula ##STR1## where Y is O, S, NR, ##STR2## each R is independently selected from hydrogen or C.sub.1 to C.sub.6 alkyl, each R' is independently selected from C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 alkoxy, C.sub.6 to C.sub.16 aryl, halogen, or CF.sub.3, M is titanium, zirconium, or hafnium, each X is independently selected from halogen, C.sub.1 to C.sub.6 alkyl, C.sub.1 to C.sub.6 alkoxy, or ##STR3## L is X, cyclopentadienyl, C.sub.1 to C.sub.6 alkyl substituted cyclopentadienyl, indenyl, fluorenyl, or ##STR4## and "n" is 1 to 4. Also disclosed is a method of making a poly-.alpha.-olefin comprising polymerizing an .alpha.-olefin monomer using that catalyst or a catalyst that has the general formula ##STR5## where Y, M, L, X, and R' were previously defined.Type: GrantFiled: April 17, 1995Date of Patent: June 10, 1997Assignee: Lyondell Petrochemical CompanyInventors: Sandor Nagy, Ramesh Krishnamurti, John A. Tyrell, Leonard V. Cribbs, Mary Cocoman