Patents by Inventor Donald R. Stevenson

Donald R. Stevenson 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).

  • Patent number: 9982112
    Abstract: A copolymeric polyphosphite is described: wherein each R1 through R5 can be the same or different and independently selected from the group consisting of C12-20 alkyl, C12-22 alkenyl, C12-40 cycloalkyl, C12-40-cycloalkenyl, C12-20 alkyl glycol ethers and A-OH and B—OH are different end-capping groups and independently selected from the group consisting of C2-40 alkylene, C7-40 cycloalkylene, C3-20 alkyl glycol ethers, C3-40 alkyl lactone, and —R7—N(R8)—R9—; wherein R7 and through R9 are independently selected from the group C1-20 alkyl, C2-22 alkenyl, C6-40 cycloalkyl, C7-40 cycloalkylene and H; m and n are integers from 1 to 100 inclusive, with various provisos.
    Type: Grant
    Filed: July 16, 2014
    Date of Patent: May 29, 2018
    Assignee: Dover Chemical Corporation
    Inventors: Michael R. Jakupca, Jacob M. Lance, Donald R. Stevenson
  • Patent number: 9745425
    Abstract: A polymeric polyphosphite and copolymeric polyphosphite is described which contains a cycloaliphatic moiety, preferably cyclohexane dimethanol, in the polyphosphite backbone chain. Incorporation of the polymeric polyphosphite into synthetic polymers reduces the yellowness index of any polymer into which the polymeric polyphosphite additive has been added, as well as increased hydrolytic stability as well as increased resistance to migration in food packaging.
    Type: Grant
    Filed: June 19, 2014
    Date of Patent: August 29, 2017
    Assignee: Dover Chemical Corporation
    Inventors: Michael R. Jakupca, Jacob M. Lance, Donald R. Stevenson
  • Publication number: 20160340493
    Abstract: The invention pertains generally to an improved polymer composition which contains at least one polymeric polyphosphite or copolymeric polyphosphite additive containing no alkylphenols. Alkylphenol-free polymeric polyphosphites offer distinct advantages over conventional phosphite technology in rubbers and rubber compounds. Polymeric polyphosphites offer improved performance in regards to the prevention of color formation during high temperature processing and NOx aging.
    Type: Application
    Filed: August 1, 2016
    Publication date: November 24, 2016
    Applicant: Dover Chemical Corporation
    Inventors: Michael R. Jakupca, Jacob M. Lance, Donald R. Stevenson
  • Publication number: 20140378590
    Abstract: A polymeric polyphosphite and copolymeric polyphosphite is described which contains a cycloaliphatic moiety, preferably cyclohexane dimethanol, in the polyphosphite backbone chain. Incorporation of the polymeric polyphosphite into synthetic polymers reduces the yellowness index of any polymer into which the polymeric polyphosphite additive has been added, as well as increased hydrolytic stability as well as increased resistance to migration in food packaging.
    Type: Application
    Filed: June 19, 2014
    Publication date: December 25, 2014
    Applicant: DOVER CHEMICAL CORPORATION
    Inventors: Michael R. Jakupca, Jacob M. Lance, Donald R. Stevenson
  • Publication number: 20140329943
    Abstract: An alkylphenol-free colorless liquid copolymeric polyphosphite is described of generic formula: wherein each R1, R2, R3, R4 and R5 can be the same or different and independently selected from the group consisting of C12-20 alkyl, C12-22 alkenyl, C12-40 cycloalkyl, C12-40-cycloalkenyl, C12-20 alkyl glycol ethers and A-OH and B—OH as an end-capping groups; each A and B are different and independently selected from the group consisting of C2-40 alkylene, C7-40 cycloalkylene, C3-20 alkyl glycol ethers, C3-40 alkyl lactone, and —R7—N(R8)—R9—; wherein R7, R8 and R9 are independently selected from the group C1-20 alkyl, C2-22 alkenyl, C6-40 cycloalkyl, C7-40 cycloalkylene and H; m and n are integral values ranging from 1 to 100 inclusive, with the proviso that when —O-A or —O—B are C3-20 alkyl glycol ethers, x or y is an integral value no less than 7; x and y are integral values ranging from 1 to 1,000 wherein x+y sum to at least 3; and further wherein no more than two of R1, R2, R3, R4 and R5 are terminated w
    Type: Application
    Filed: July 16, 2014
    Publication date: November 6, 2014
    Applicant: DOVER CHEMICAL CORPORATION
    Inventors: Michael R. Jakupca, Jacob M. Lance, Donald R. Stevenson
  • Publication number: 20110196079
    Abstract: A process to stabilize a polymer is described utilizing the step of adding a phosphite reaction product of a triphenyl phosphite or lower molecular weight trialkyl phosphite (e.g., trimethyl phosphite) or triaryl phosphite, with from approximately 1 to 2 moles of preferably a paracumyl phenol, and with from approximately 1 to 2 moles of at least C12-20 carbon alkyl or C12-20 alkenyl alcohol.
    Type: Application
    Filed: February 5, 2010
    Publication date: August 11, 2011
    Applicant: DOVER CHEMICAL CORPORATION
    Inventors: Michael JAKUPCA, Jacob M. LANCE, Nina BERSAGLINI, Donald R. STEVENSON
  • Patent number: 7595412
    Abstract: A novel composition and methods of its use and preparation of polybasic metal carboxylate complexes having the general formula: (A)2M.nD(OH)2.xH2O.m(B)2N wherein: A is an organic fatty acid and is selected from the group consisting of saturated C12-24 carboxylic acids, unsaturated C12-24 carboxylic acids, aromatic C12-24 carboxylic acids, alicyclic C12-24 carboxylic acids, polycarboxylic acid derivatives thereof, anhydride derivatives thereof and blends thereof, preferably stearate; M is a divalent metal cation, preferably calcium; n is a fractional or whole number from about 1 to about 10 inclusive; D is an alkali earth metal, preferably calcium; x is a fractional or whole number from about 0 to about 3 inclusive; N is a divalent metal cation other than calcium, preferably zinc; and m is a fractional or whole number from 0 to about 1.
    Type: Grant
    Filed: August 5, 2002
    Date of Patent: September 29, 2009
    Assignee: Dover Chemical Corporation
    Inventors: Thomas Jennings, Ssatyan Kodali, W. Matthew Fender, Donald R. Stevenson
  • Patent number: 7470735
    Abstract: Various phenol-free phosphites for use in PVC as an alternative to the conventional phenol-containing products phenyl diisodecyl phosphite and diphenyl isodecyl phosphite were tested. These phosphites utilize para-cumyl phenol-based derivatives in order to provide a phenol free derivative of the above mentioned conventional phosphites.
    Type: Grant
    Filed: May 14, 2004
    Date of Patent: December 30, 2008
    Assignee: Dover Chemical Corporation
    Inventors: Donald R. Stevenson, Duong N. Nguyen, Mark E. Harr, Michael R. Jakupca
  • Patent number: 7320764
    Abstract: The invention relates to liquid polymer additive compositions comprising blends of phosphite esters selected from the group consisting of aryl phosphites, alkyl phosphites, aryl/alkyl phosphites, bisphenol-A phosphites, dialkylene glycol phosphites and polydialkylene glycol phosphites, pentaerythritol phosphites, p-cumyl phenol phosphites with from 50 to 800 ppm inclusive of zinc per 100 parts resin. The stabilizer is used as either a complete or a partial replacement of toxic-metal containing antioxidant stabilizer additives.
    Type: Grant
    Filed: May 11, 2004
    Date of Patent: January 22, 2008
    Assignee: Dover Chemical Corporation
    Inventors: Donald R. Stevenson, Thomas C. Jennings, Mark E. Harr, Michael R. Jakupca
  • Patent number: 7294684
    Abstract: The invention relates to a process and composition-of-matter for the preparation of dimeric and polymeric alkylphenol polysulfides based on paracumyl phenol for use in vulcanizable rubbers in which the additive is a dimeric or polymeric alkylphenol polysulfide non-nitrosamine-releasing additive based on paracumyl phenol.
    Type: Grant
    Filed: November 11, 2006
    Date of Patent: November 13, 2007
    Assignee: Dover Chemical Corporation
    Inventors: Donald R. Stevenson, Satyan Kodali, Duong N. Nguyen
  • Patent number: 7176252
    Abstract: A solid phosphite composite, having at least a portion in amorphous form, which includes at least one, preferably two or more phosphite antioxidants or alternatively at least one phosphite and at least one other polymer additive. The phosphites, at least one of which can initially be a liquid, are generally uniformly distributed since they are melt blended. A desired class of phosphites are the bis(arylalkylphenyl)pentaerythritol diphosphites, at least a portion of which is in amorphous form.
    Type: Grant
    Filed: February 13, 2004
    Date of Patent: February 13, 2007
    Assignee: Dover Chemical Corporation
    Inventors: Donald R. Stevenson, Satyan Kodali, Carroll W. Larke
  • Publication number: 20040242908
    Abstract: A novel composition and methods of its use and preparation of polybasic metal carboxylate complexes having the general formula: (A)2M.nD(OH)2.xH2O.m (B)2N wherein: (a) A is an organic fatty acid and is selected from the group consisting of saturated C12-24 carboxylic acids, unsaturated C12-24 carboxylic acids, aromatic C12-24 carboxylic acids, alicyclic C12-24 carboxylic acids, polycarboxylic acid derivatives thereof, anhydride derivatives thereof and blends thereof, preferably stearate; (b) M is a divalent metal cation, preferably calcium; (c) n is a fractional or whole number from about 1 to about 10 inclusive; (d) D is an alkali earth metal, preferably calcium; (e) x is a fractional or whole number from about 0 to about 3 inclusive; (f) N is a divalent metal cation other than calcium, preferably zinc; and (g) m is a fractional or whole number from 0 to about 1.
    Type: Application
    Filed: February 12, 2004
    Publication date: December 2, 2004
    Inventors: Thomas Jennings, Ssatyan Kodali, W. Matthew Fender, Donald R Stevenson
  • Publication number: 20040183054
    Abstract: The invention relates to liquid polymer additive compositions comprising blends of phosphite esters selected from the group consisting of aryl phosphites, alkyl phosphites, aryl/alkyl phosphites, bisphenol-A phosphites, dialkylene glycol phosphites and polydialkylene glycol phosphites, pentaerythritol phosphites, p-cumyl phenol phosphites with from 50 to 800 ppm inclusive of zinc per 100 parts resin. The stabilizer is used as either a complete or a partial replacement of toxic-metal containing antioxidant stabilizer additives.
    Type: Application
    Filed: May 11, 2004
    Publication date: September 23, 2004
    Applicant: DOVER CHEMICAL CORPORATION
    Inventors: Donald R. STEVENSON, Thomas C. JENNINGS, Mark E. HARR, Michael R. Jakupca
  • Publication number: 20040180999
    Abstract: Various phenol-free phosphites for use in PVC as an alternative to the conventional phenol-containing products phenyl diisodecyl phosphite and diphenyl isodecyl phosphite were tested. These phosphites utilize para-cumyl phenol-based derivatives in order to provide a phenol free derivative of the above mentioned conventional phosphites.
    Type: Application
    Filed: May 14, 2004
    Publication date: September 16, 2004
    Applicant: DOVER CHEMICAL CORPORATION
    Inventors: Donald R. STEVENSON, Duong N. NGUYEN, Mark E. HARR, Michael R. JAKUPCA
  • Publication number: 20040164279
    Abstract: A solid phosphite composite, having at least a portion in amorphous form, which includes at least one, preferably two or more phosphite antioxidants or alternatively at least one phosphite and at least one other polymer additive. The phosphites, at least one of which can initially be a liquid, are generally uniformly distributed since they are melt blended. A desired class of phosphites are the bis(arylalkylphenyl)pentaerythritol diphosphites, at least a portion of which is in amorphous form.
    Type: Application
    Filed: February 13, 2004
    Publication date: August 26, 2004
    Inventors: Donald R. Stevenson, Satyan Kodali, Carroll W. Larke
  • Patent number: 6362260
    Abstract: Liquid organic phosphites of low volatility, based on pentaerythritol, alkyl alcohols and alkyl phenols, which are essentially phenol-free are disclosed. These phosphites are excellent stabilizers for polymers, especially PVC resins. The phenol-free phosphite stabilizers are compatible with mixed metal stabilizers and give excellent color and processing stability.
    Type: Grant
    Filed: December 22, 1999
    Date of Patent: March 26, 2002
    Assignee: Dover Chemical Corporation
    Inventors: Donald R. Stevenson, Duong Nguyen
  • Patent number: 6174125
    Abstract: The present invention is directed towards a method for racking or unracking pipe to or from a rack and a device to facilitate the process. The method provides a controllable procedure for inserting or withdrawing the pipe that is less dangerous than prior art methods and does not damage the pipe end. The method entails inserting a pipe gripper having an expansion sleeve into an accessible end of a pipe. The expansion sleeve is forced against an inner wall of the pipe, coupling the pipe gripper to the pipe. Depending upon the application, the pipe is then either pushed fully onto the rack or is pulled partially off the rack. For unracking operations, a crane sling is attached to the partially unracked pipe and the pipe is further manipulated off the rack.
    Type: Grant
    Filed: September 29, 1999
    Date of Patent: January 16, 2001
    Assignee: Newport News Shipbuilding & Dry Dock Company
    Inventors: Marney L. Davis, George H. Wallace, Loren C. Cave, Donald R. Stevenson
  • Patent number: 5939366
    Abstract: The invention pertains to chlorine-free extreme pressure metalworking fluid additives and lies in the recognition of the improved hydrolytic stability of alkanoic acid esters of cyclohexane dimethanol and other esters embodying similar structures. The various derivatives which are effective as extreme pressure additives include those which fall within the generic description ##STR1## wherein R.sup.1 through R.sup.4 are independently selected from the group hydrogen and C.sub.1-24 hydrocarbyl groups and R.sup.5 and R.sup.6 are independently selected from the group C.sub.3-24 hydrocarbyl groups.
    Type: Grant
    Filed: February 26, 1998
    Date of Patent: August 17, 1999
    Assignee: Dover Chemical Corp.
    Inventors: James MacNeil, Donald R. Stevenson, Barbara A. Wade, Joseph C. Fette
  • Patent number: 5780400
    Abstract: The invention pertains to chlorine-free extreme pressure metalworking fluid additives and lies in the recognition of the improved hydrolytic stability of alkanoic acid esters of cyclohexane dimethanol and other esters embodying similar structures. The various derivatives which are effective as extreme pressure additives include those which fall within the generic description ##STR1## wherein R.sup.1 through R.sup.4 are independently selected from the group hydrogen and C.sub.1-24 hydrocarbyl groups and R.sup.5 and R.sup.6 are independently selected from the group C.sub.3-24 hydrocarbyl groups.
    Type: Grant
    Filed: July 21, 1997
    Date of Patent: July 14, 1998
    Assignee: Dover Chemical Corp.
    Inventors: James MacNeil, Donald R. Stevenson, Barbara A. Wade, Joseph C. Fette
  • Patent number: 5532401
    Abstract: An improved process for the preparation of tris(nonylphenyl) phosphite is described which includes the steps of combining at least a 4 weight percent excess of nonylphenol (preferably 8 weight percent excess) with PCl.sub.3 with agitation and heating sufficient to liberate HCl formed during the synthetic reaction as a by-product and removing the excess nonylphenol from the tris(nonylphenyl) phosphite by thin film distillation to reduce the residual chloride level to 90 ppm or less, an acid number of 0.1 or less and a nonylphenol content after stripping of 0.1 weight percent or less. The temperature of the reaction was from room temperature to 130.degree. C., and the temperature of the evaporator which removes the excess nonylphenol is from 100.degree. C. to 350.degree. C., preferably from 150.degree. C. to 250.degree. C., under a system vacuum of from 0.01 mm Hg to 5 mm Hg.
    Type: Grant
    Filed: January 19, 1995
    Date of Patent: July 2, 1996
    Assignee: Dover Chemical Corporation
    Inventors: Donald R. Stevenson, Daniel L. Clark, John C. Debevec, Charles N. Slater, Carroll W. Larke