Carbon Attached Directly Or Indirectly To The Silicon By Nonionic Bonding (e.g., Silanes, Etc.) Patents (Class 556/465)
  • Patent number: 4649207
    Abstract: Derivatives of diphenylhexafluoropropane having the formula: ##STR1## where R is an unsubstituted or substituted alkylene, an epoxy, a silyl or alkoxysilyl group; and where X and Y are hydrogen or halogen. The derivatives are useful in formulating polymer structures.
    Type: Grant
    Filed: May 13, 1986
    Date of Patent: March 10, 1987
    Assignee: Hughes Aircraft Company
    Inventors: Kreisler S. Y. Lau, William J. Kelleghan
  • Patent number: 4642356
    Abstract: New organosilicon compounds of the formula ##STR1## R represents a hydrogen radical with 1 to 6 carbon atoms, or a phenyl radical;R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same or different and represent hydrogen or methyl radicals;R.sup.5, R.sup.6, R.sup.7 and R.sup.8 are the same or different and represent hydrogen, fluorine or hydrocarbon radicals with 1 to 8 carbon atoms, or fluorinated hydrocarbon radicals, in which at least one R.sup.5, R.sup.6 R.sup.7 or R.sup.8 radicals must be a fluorine or a fluorinated hydrocarbon radical;Y is a hydrolyzable radical, hydroxyl radical or organosiloxanyl radical;A represents ##STR2## in which R.sup.9 may be the same or different and represents a hydrogen or a methyl radical; anda has a value of 0, 1, 2, or 3.
    Type: Grant
    Filed: June 14, 1985
    Date of Patent: February 10, 1987
    Assignee: Th. Goldschmidt AG
    Inventors: Jaroslav Langner, Christian Weitemeyer
  • Patent number: 4640792
    Abstract: A random siloxane copolymer composition, and a process for using the composition in a hydraulic brake system of a vehicle, is described. The random copolymer consists essentially of alkylmethylsiloxane and dimethylsiloxane units, wherein said alkyl group contains from five to ten carbon atoms, and the viscosity of said fluid is 15-50 cS at 25.degree. C. Within a relatively narrow compositional range, these fluids dissolve at least 15% less air than comparable polydimethylsiloxane fluids. Moreover, the copolymer may be readily formulated into brake fluid compositions which meet Department of Transportation (DOT 5) and, in the case of preferred compositions, Military (MIL-B-46176) specifications. The potential benefit of reduced air solubility is an improved margin of safety under harsh driving conditions.
    Type: Grant
    Filed: November 25, 1985
    Date of Patent: February 3, 1987
    Assignee: Dow Corning Corporation
    Inventors: Eugene D. Groenhof, David J. Romenesko, Rick D. Streu
  • Patent number: 4634546
    Abstract: An improved procedure is provided for increasing the electrical conductivity of graphite via intercalation. It has been found that fully halogenated hydrocarbons (as described) have the ability to substantially aid the intercalation of graphite by previously known intercalant mixtures of (a) fluorosulfonic acid, chlorosulfonic acid, or mixtures thereof, and (b) a boron trihalide, a tetrahalide of a Group IV element, a pentahalide of a Group V element, or mixtures thereof. The presence of a fully halogenated hydrocarbon, such as carbon tetrachloride, during the graphite intercalation reaction has been found to expedite the rate at which intercalation takes place and possibly enables the achievement of a greater electrical conductivity than would have otherwise been obtained. In a preferred embodiment the graphite carbon is present within a carbonaceous fibrous material at the time of its intercalation and the resulting product is substantially electrically oriented along the axis of the fiber.
    Type: Grant
    Filed: July 19, 1985
    Date of Patent: January 6, 1987
    Assignee: Celanese Corporation
    Inventors: Ilmar L. Kalnin, Harris A. Goldberg, George J. Breckenridge, Jr.
  • Patent number: 4632775
    Abstract: An improved procedure is provided for increasing the electrical conductivity of graphite via intercalation. It has been found that sulfur trioxide has the ability to substantially aid the intercalation of graphite by previously known intercalants such as (a) fluorosulfonic acid, chlorosulfonic acid, or mixtures thereof, (b) a boron trihalide, a tetrahalide of a Group IV element, a pentahalide of a Group V element, or mixtures thereof, and (c) mixtures of (a) and (b). Such presence of sulfur trioxide during the graphite intercalation reaction has been found to expedite the rate at which intercalation takes place and possibly enables the achievement of a greater electrical conductivity than would have otherwise been obtained. In a preferred embodiment the graphitic carbon is present within a carbonaceous fibrous material at the time of its intercalation and the resulting product is substantially electrically oriented along the axis of the fiber.
    Type: Grant
    Filed: May 28, 1985
    Date of Patent: December 30, 1986
    Assignee: Celanese Corporation
    Inventors: Ilmar L. Kalnin, Harris A. Goldberg, George J. Breckenridge, Jr.
  • Patent number: 4623741
    Abstract: An ethylidenenorbornyl group-containing chlorosilanes compound represented by the general formula:Y.sub.a (R.sup.1).sub.b Si(Cl).sub.4-a-bwherein R.sup.1 stands for a saturated or unsaturated monovalent hydrocarbon group of 1 to 8 carbon atoms, Y for ##STR1## a for an integer of the value of 1 to 3, b for an integer of the value of 0 to 2, and a+b for an integer of the value of 1 to 3.
    Type: Grant
    Filed: January 24, 1986
    Date of Patent: November 18, 1986
    Assignee: Toshiba Silicone Co., Ltd.
    Inventors: Junichiro Watanabe, Yuichi Funahashi
  • Patent number: 4611042
    Abstract: A xylene-soluble, resinous copolymer containing SiO.sub.2 units, trimethylsiloxane units, and alkenyldimethylsiloxane units such as 5-hexenyldimethylsiloxane units is disclosed. The resinous copolymer is useful as a component in silicone coatings, especially silicone release coatings, to provide intermediate range release forces against adhesives. The higher alkenyl functionality provides faster reaction with other coating components and reduced odor during cure of UV curable mercaptosilicone compositions.
    Type: Grant
    Filed: October 3, 1985
    Date of Patent: September 9, 1986
    Assignee: Dow Corning Corporation
    Inventors: Stacia A. Rivers-Farrell, Antony P. Wright
  • Patent number: 4604480
    Abstract: A method for the preparation of a first sulfone compound of the formula: ##STR1## wherein R.sub.a is ##STR2## where R.sub.b is Br and R.sub.c is H except that R.sub.b and R.sub.c together may be an electron pair when R.sub.6 is a radical of the formula: ##STR3## wherein X.sub.1 is independently chlorine, bromine or iodine and R.sub.1 and R.sub.2 are independently at each occurrence hydrogen or, substituted or unsubstituted, phenyl or alkyl where the substituents are halogen or alkoxy or additional --SO.sub.2 Br groups; provided that, each carbon atom of R.sub.1 or R.sub.2 which contains --SO.sub.2 Br also contains an X.sub.1 group and wherein R.sub.3 through R.sub.9 are independently --OZ,--C.sub.6 M.sub.5,--Z,--SiZ.sub.3 or --X.sub.2, where Z is hydrogen or substituted or unsubstituted phenyl, alkyl, alkenyl or alkynyl; X.sub.2 is chlorine, bromine, iodine or fluorine; M is independently at each occurrence Z or X.sub.2 ; R.sub.3 and R.sub.4 may together be an electron pair; two or more of R.sub.3, R.sub.
    Type: Grant
    Filed: August 15, 1983
    Date of Patent: August 5, 1986
    Assignee: The Research Foundation of State University of New York
    Inventors: Eric Block, Mohammad Aslam
  • Patent number: 4579966
    Abstract: Novel terpenoid alkoxysilanes having the general formula: ##STR1## wherein Y is hydrogen or Si(R.sup.2).sub.n X.sub.m (OR.sup.3).sub.3-(N-m), Z is hydrogen or Si(R.sup.2).sub.n X.sub.m (OR.sup.3).sub.3-(n+m), one of Y and Z being Si(R.sup.2).sub.n X.sub.m (OR.sup.3).sub.3-(n+m), R.sup.2 and R.sup.3 being the same or different C.sub.1 -C.sub.3 alkyl group, X is halogen, m and n are independently selected from 1 and 0, and II W is Si(R.sup.2).sub.n X.sub.m (OR.sup.3).sub.3-(n+m), where R.sup.2, R.sup.3, X, n and m are as defined above.
    Type: Grant
    Filed: January 14, 1985
    Date of Patent: April 1, 1986
    Assignee: SCM Corporation
    Inventors: Ralph J. De Pasquale, Paul W. Kremer
  • Patent number: 4572791
    Abstract: The silahydrocarbon product containing at least 75 weight percent of saturated silahydrocarbons with the remainder being unsaturated silahydrocarbons is produced by a process in which admixture comprising(A) at least one alpha-olefin containing from 2 to about 20 carbon atoms per molecule, and(B) at least one alkylsilane selected from the group consisting of(i) a dialkylsilane having the formulaR--SiH.sub.2 --R.sub.1(ii) a trialkylsilane having the formula ##STR1## and (iii) mixtures thereof,wherein R and R.sub.1, the same or different, each represent an alkyl radical of from one to 20 carbon atoms per molecule with a catalyst comprising a homogeneous rhodium-containing catalyst or a heterogeneous rhodium-containing catalyst in a halogen-free inert solvent, under hydrosilylation reaction conditions to produce a mixture containing saturated and unsaturated silane hydrocarbons useful as lubricants.
    Type: Grant
    Filed: December 6, 1984
    Date of Patent: February 25, 1986
    Assignee: Gulf Research & Development Company
    Inventors: Anatoli Onopchenko, Edward T. Sabourin
  • Patent number: 4564467
    Abstract: This invention concerns an oil composition comprising a major proportion by weight of an oil having a kinematic viscosity of 5 to 30 cSt at 40.degree. C. e.g. a transformer oil, and a minor proportion by weight of an organo siloxane having the formula: ##STR1## wherein R.sup.1 is independently methyl, ethyl or propyl,R.sup.2 is independently a C.sub.10 to C.sub.20 alkyl group andn is 12 to 28.Such oil compositions having low pour points and excellent dielectric properties can be used as electrical oils.
    Type: Grant
    Filed: December 28, 1983
    Date of Patent: January 14, 1986
    Assignee: Exxon Research and Engineering Co.
    Inventor: Alain J. Rauline
  • Patent number: 4541936
    Abstract: An aqueous emulsion comprising an aminoorgano-substituted organopolysiloxane fluid, a silane which bears a hydrophilic group, one or more surfactants and water are useful for treating fibers, such as thread, yard and textiles. When applied to a fiber and heated the composition undergoes a curing reaction and durably imparts desirable properties, such as excellent hand and moisture absorbability, to the fiber.
    Type: Grant
    Filed: August 20, 1984
    Date of Patent: September 17, 1985
    Assignee: Toray Silicone Company, Ltd.
    Inventors: Isao Ona, Masaru Ozaki
  • Patent number: 4513137
    Abstract: Mono- or bis(iodonium salts) are produced in neutral organic solvents by the reaction of an [hydroxy (organosulfonyloxy)iodo]arene with a bis(triorganosilyl)arene, a bis(trihalosilyl)arene, or with a mono- or bis(triorganosilyl)heterocyclic compound, or a mono- or bis(trihalosilyl)heterocyclic. The iodonium salts are made under conditions of regiospecific control.
    Type: Grant
    Filed: April 9, 1981
    Date of Patent: April 23, 1985
    Assignee: The University of Akron
    Inventors: Gerald F. Koser, Carol S. Carman
  • Patent number: 4505905
    Abstract: Certain 7-oxobicyclo[3.2.0] hept-2-en-2-carboxylic acids, esters, and salts thereof useful as antibacterial agents or as intermediates for antibacterial agents, and methods for making and using them.
    Type: Grant
    Filed: April 15, 1982
    Date of Patent: March 19, 1985
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: George A. Boswell, Jr., Anthony J. Cocuzza
  • Patent number: 4502973
    Abstract: Electroviscous (EV) fluids consisting of solid hydrophilic particles dispersed in hydrophobic liquids, where the liquid contains a diaryl derivative component of general formula I ##STR1## in which R is CY.sub.2,O,S,SO,SO.sub.2,SiF.sub.2, or O--SiY.sub.2 --O,X.sup.1 and X.sup.2 are halogens, (m+n) is between 1 and 3 on average, and (p+q) is between 0 and 1 on average. EV fluids containing these novel components possess generally improved properties in terms of lower viscosities, electrical conductivities, toxicities and freezing points. In a preferred embodiment, the component is a mixture of brominated diphenyl methanes in which R is CH.sub.2,n=O,X.sup.1 =Br,(m+n) is approximately one, and (p+q)=0.
    Type: Grant
    Filed: February 3, 1983
    Date of Patent: March 5, 1985
    Assignee: National Research Development Corporation
    Inventor: James E. Stangroom
  • Patent number: 4458087
    Abstract: There are prepared silafluoroolefins and polymers thereof by reacting carbon with silicon tetrafluoride and a source of hydrogen followed by polymerization. The polymers are useful for architectural purposes.
    Type: Grant
    Filed: October 16, 1981
    Date of Patent: July 3, 1984
    Inventor: Roy E. McAlister
  • Patent number: 4421657
    Abstract: A heavy duty laundering and textile softening detergent composition, in particulate form, useful for automatic machine washing of laundry in water, especially hot water, and readily dispensable from a charging compartment of an automatic washing machine (by action of water being fed through such compartment) includes a synthetic organic detergent, a builder for such detergent and a laundry softening proportion of bentonite, with which there is present a dispensing assisting proportion of a siliconate or similarly functioning derivative of such siliconate. In addition to tending to inhibit firm adherence to the charging compartment walls of the bentonite, which is advantageously in separately agglomerated bead form, and promoting release thereof from such walls, the siliconate also aids in controlling the foaming activity of the built synthetic organic detergent and strengthening the bentonite agglomerates.
    Type: Grant
    Filed: April 8, 1982
    Date of Patent: December 20, 1983
    Assignee: Colgate-Palmolive Company
    Inventors: Edwin Allen, Alan Dillarstone, Joseph A. Reul
  • Patent number: 4419250
    Abstract: A heavy duty laundering and textile softening detergent composition, in particulate form, useful for automatic machine washing of laundry in water, especially hot water, and readily dispensable from a charging compartment of an automatic washing machine (by action of water being fed through such compartment) includes a synthetic organic detergent, a builder for such detergent and a laundry softening proportion of bentonite, with which there is present a dispensing assisting proportion, at least 0.15%, of a siliconate or similarly functioning derivative of such siliconate. In addition to inhibiting adherence to the charging compartment walls of the bentonite, which is advantageously in separately agglomerated bead form, and promoting release thereof from such walls, the siliconate also aids in controlling the foaming activity of the built synthetic organic detergent and strengthening the bentonite agglomerates.
    Type: Grant
    Filed: April 8, 1982
    Date of Patent: December 6, 1983
    Assignee: Colgate-Palmolive Company
    Inventors: Edwin Allen, Alan Dillarstone, Joseph A. Reul
  • Patent number: 4411740
    Abstract: A method for separating close-boiling chlorosilanes by the procedures of extractive distillation using sulfolane as the extractive solvent is described. An example of close-boiling chlorosilanes which can be separated by this method include dimethyldichlorosilane and methyltrichlorosilane containing mixtures. The invention comprises heating a mixture of the close-boiling chlorosilanes with sulfolane to distill the lower-boiling chlorosilane from the mixture and thereafter separating the sulfolane and the high-boiling chlorosilane.
    Type: Grant
    Filed: September 20, 1982
    Date of Patent: October 25, 1983
    Assignee: Dow Corning Corporation
    Inventors: Ora L. Flaningam, Roland L. Halm
  • Patent number: 4408017
    Abstract: Lithium metal-terminated polymers of one or more alkadienes and of one or more monoalkenyl arenes are coupled by reaction with a coupling agent which has the general formula ##STR1## where X is hydrogen, halogen or an alkyl group and Y is halogen or an alkoxy group.
    Type: Grant
    Filed: May 26, 1982
    Date of Patent: October 4, 1983
    Assignee: Shell Oil Company
    Inventor: Michael K. Martin
  • Patent number: 4381377
    Abstract: A homo- or copolymer of a 1,3-diene bound to reactive silyl groups, whereby it contains 0.4-12% by weight of bound silicon, is prepared by reacting, at a temperature of 190.degree.-300.degree. C., a 1,3-diene homo- or copolymer, with more than 1% of its aliphatic double bonds in conjugation and having a molecular weight (Mn) of 400-6,000, with a silane of the formula ##STR1## wherein R is an unsaturated aliphatic hydrocarbon radical of 2-20 carbon atoms,X is halogen, C.sub.1-6 alkoxy, C.sub.1-6 alkoxyalkoxy, C.sub.6-12 aryloxy, C.sub.1-8 alkanoyloxy, C.sub.1-6 ketoximato or C.sub.1-10 hydrocarbylamido, andY and Z are independently one of the X groups, hydrogen, alkyl of 1-8 carbon atoms, cycloalkyl of 5-12 carbon atoms, or optionally substituted phenyl.
    Type: Grant
    Filed: February 2, 1981
    Date of Patent: April 26, 1983
    Assignee: Chemische Werke Huels, AG
    Inventors: Wolfgang Kampf, Roland Streck, Horst-guenter Haag
  • Patent number: 4374291
    Abstract: Bis(ethynylphenyl) compounds are prepared by an improved synthesis process which increases yield and is suitable for large scale synthesis operations. Aromatic dianilines are diazotized to form aromatic halides that are subsequently coupled with an end-protecting group having acetylenic moieties. The end-protecting groups are subsequently removed leaving the desired diethynyl derivative in quantitative yields.
    Type: Grant
    Filed: November 6, 1981
    Date of Patent: February 15, 1983
    Assignee: Hughes Aircraft Company
    Inventor: Kreisler S. Y. Lau
  • Patent number: 4328353
    Abstract: There is provided an improved process for removing residual silicon and copper powder from the gaseous organohalosilane products of a direct process reactor which utilizes sintered metal filtering elements to filter out the said powder from gaseous organoalosilanes which have been processed in primary and secondary cyclones.
    Type: Grant
    Filed: March 30, 1981
    Date of Patent: May 4, 1982
    Assignee: General Electric Company
    Inventor: Bakulesh N. Shah
  • Patent number: 4297499
    Abstract: Novel disubstituted dichlorosilane compounds which have two different specified substituents and are necessary as monomers for preparing special silicone resin are provided and a method for producing same without accompaniment of by-product production is also provided.
    Type: Grant
    Filed: April 11, 1978
    Date of Patent: October 27, 1981
    Assignee: Chisso Corporation
    Inventors: Isao Koga, Yohji Terui, Masuhito Ohgushi, Tohru Kitahara
  • Patent number: 4287354
    Abstract: Nonpolar, organic solvent-soluble tellurium compounds and complexes are disclosed. The compounds are tellurium(II) compounds and are represented by the formula:Te[ (CH.sub.2).sub.n SiRR'R"].sub.2wherein:n is an integer from 1 to 10 andR, R' and R" are independently selected from the group consisting of alkyl, aryl and heterocyclic radicals. Photosensitive complexes of these compounds with transition metals, as well as photographic elements having layers comprising these complexes, are also disclosed.
    Type: Grant
    Filed: October 20, 1980
    Date of Patent: September 1, 1981
    Assignee: Eastman Kodak Company
    Inventor: Henry J. Gysling
  • Patent number: 4269780
    Abstract: A process for forming non-polymeric disproportionation products of non-conjugated olefins using catalysts comprising (1) at least one of certain neutral carbene complexes, and (2) at least one of certain compounds of Groups IVa, IVb, Vb, VIb, VIIb, VIII, and Ib of the Periodic Table of the Elements.
    Type: Grant
    Filed: December 6, 1979
    Date of Patent: May 26, 1981
    Assignee: Phillips Petroleum Company
    Inventor: Dennis S. Banasiak
  • Patent number: 4268682
    Abstract: Novel .omega.alkenyl silane monoadducts and bis-.alpha., .omega.-silyl alkanes are disclosed. The .omega.-alkenyl silanes or bis-.alpha.,.omega.-silyl alkanes are prepared by the selective addition of silane having chlorine, alkoxy or acyloxy groups to an .alpha.,.omega.-diene. The additions may be carried out in the liquid phase in the presence of free radical and/or metal and/or metal salt catalyst.
    Type: Grant
    Filed: December 12, 1977
    Date of Patent: May 19, 1981
    Assignee: Exxon Research & Engineering Co.
    Inventors: Alexis A. Oswald, Lawrence L. Murrell
  • Patent number: 4258128
    Abstract: Nonpolar, organic solvent-soluble tellurium compounds and complexes are disclosed. The compounds are tellurium(II) compounds and are represented by the formula:Te----CH.sub.2).sub.n SiRR'R"].sub.2wherein:n is an integer from 1 to 10 andR, R' and R" are independently selected from the group consisting of alkyl, aryl and neterocyclic radicals. Photosensitive complexes of these compounds with transition metals, as well as photographic elements having layers comprising these complexes, are also disclosed.
    Type: Grant
    Filed: December 1, 1978
    Date of Patent: March 24, 1981
    Assignee: Eastman Kodak Company
    Inventor: Henry J. Gysling
  • Patent number: 4254271
    Abstract: In the addition of an unsaturated compound into a silane of the formulaR.sub.1 R.sub.2 SiXHwhereinX is Cl or Br, andR.sub.1 and R.sub.2 each independently is an alkyl, aryl or aralkyl radical with up to 20 C atoms, or an alkenyl or alkinyl radical with up to 12 C atoms,the improvement which comprises effecting the addition reaction in the presence of at least one of aluminum chloride, aluminum bromide, aluminum oxychloride and aluminum oxybromide.
    Type: Grant
    Filed: January 12, 1979
    Date of Patent: March 3, 1981
    Assignee: Bayer Aktiengesellschaft
    Inventors: Ulrich Finke, Hans-Heinrich Moretto
  • Patent number: 4245056
    Abstract: A silicon peroxide selected from the formulas:(R').sub.4-n --Si--(OOR).sub.n (a) ##STR1## wherein n is an integer of 1-3; R is a t-octyl group in which a tertiary carbon atom is directly bonded to the peroxy group; and R' is selected from alkyl, phenyl, and alkenyl (provided n is not more than 2), and a carbon chain which forms a saturated heterocyclic ring with the silicon atom, each R' group having up to about 10 carbon atoms. Typical is trimethyl (2,4,4-trimethyl-2-pentylperoxy) silane. These molecules are useful as catalysts for curing polyester resins and are particularly advantageous as crosslinking agents for high density polyethylene in that crosslinking is effected at lower temperatures than required by the prior art.
    Type: Grant
    Filed: November 23, 1979
    Date of Patent: January 13, 1981
    Assignee: Argus Chemical Corporation
    Inventors: Lawrence A. Bock, Reidar Halle
  • Patent number: 4243611
    Abstract: Prostaglandin derivatives having a 19,20-didehydro, a 19-hydroxy, or a 19-keto feature are disclosed, including processes for preparing them and the appropriate intermediates.A typical 19-hydroxy compound of this invention is 19-hydroxy-19-methyl-PGF.sub.2.alpha.
    Type: Grant
    Filed: April 2, 1979
    Date of Patent: January 6, 1981
    Assignee: The Upjohn Company
    Inventor: John C. Sih
  • Patent number: 4214914
    Abstract: According to the invention, the method for producing mineral polymer fillers containing graft hydroperoxide groups consists in treating mineral fillers at a temperature of 50.degree. to 150.degree. C. and a pressure of 1.33.10.sup.2 to 4.10.sup.5 Pa (1 mm Hg to 4 atm) with organosilicon compounds of the general formula:R.sub.4-y SiX.sub.yorR'R.sub.3-z SiX.sub.z,whereR is vinyl, allyl or norbornyl,X is chlorine, alkoxy or acyloxy,y=1-3,z=1-2,R' is methyl, ethyl or propyl,whereupon the mineral filler containing graft unsaturated groups is separated from the reaction mixture, dried and ozonized with an ozone-oxygen mixture containing 4 to 6 percent by volume of ozone at a temperature of -20.degree. C. to +20.degree. C. in an aliphatic saturated monohydric alcohol or aliphatic saturated monohydric acid.The method for producing mineral polymer fillers containing graft hydroperoxide groups is quite simple and makes it possible to carry out the filling and grafting of polymers at a reduced temperature of 50.degree.
    Type: Grant
    Filed: November 20, 1978
    Date of Patent: July 29, 1980
    Inventors: Sergei S. Ivanchev, Nikolai S. Enikolopov, Boris V. Polozov, Anatoly A. Syrov, Oleg N. Primachenko, Zorislav N. Polyakov