Patents by Inventor Ramesh C. Kumar

Ramesh C. Kumar 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: 5349004
    Abstract: Novel pressure-sensitive adhesives are described which show significant resistance to solvents and working fluids such as jet fuel, hydraulic fluid, de-icing fluid and the like. Adhesive compositions comprise nonaqueous dispersions of copolymers of acrylic monomers prepared in the presence of a vinyl-substituted fluoroalkyl siloxane having the general formula I and a macromonomeric stabilizer. The adhesives prepared from the adhesive compositions exhibit excellent adhesion to glass, aluminum, and low surface-energy materials such as fluoroalkyl siloxane elastomers.
    Type: Grant
    Filed: September 18, 1992
    Date of Patent: September 20, 1994
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Ramesh C. Kumar, Albert I. Everaerts, Yvan A. Bogaert
  • Patent number: 5240972
    Abstract: The present invention relates to an iniferter compound of the formula I(T).sub.n wherein I represents the free radical initiator portion of the iniferter compound and wherein I comprises a hydroxy-functional polyurethane polymer which comprises: (i) a polyurethane backbone; (ii) a plurality of cross-linkable hydroxy groups pendant from the polyurethane backbone, wherein the polyurethane backbone has a hydroxy equivalent weight of from about 500 to about 10,000; (iii) at least n organic groups X which can be the same or different pendant from the polyurethane backbone wherein each organic group X is also bonded to a T group; T represents the terminator portion of the iniferter; and n is an integer of at least 1; wherein T and X are organic groups selected so that the T--X bond is capable of dissociating upon being subjected to an appropriate energy source of forming a terminator free radical of the formula nT.multidot. and an initiator free radical of the formula I(.multidot.).sub.n .
    Type: Grant
    Filed: April 30, 1992
    Date of Patent: August 31, 1993
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Ramesh C. Kumar, Takatoshi Ohkubo
  • Patent number: 5229179
    Abstract: Iniferter prepared release coating compositions comprising vinyl-siloxane block copolymer and blends thereof with other polymeric materials on sheet materials and the backside of adhesive tapes are provided. Controlled and predictable release is obtained through variation of the molecular weight and weight percent of the siloxane block as well as the molecular weight and composition of the vinyl block or blocks.
    Type: Grant
    Filed: June 24, 1992
    Date of Patent: July 20, 1993
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Ramesh C. Kumar, Steven S. Kantner
  • Patent number: 5218072
    Abstract: The invention relates to a sulfonated, thiol, and hydroxy-functional polyurethane polymer which comprises: (i) a polyurethane backbone; (ii) at least one SO.sub.3 M group pendant from the polyurethane backbone, wherein the polyurethane backbone has an SO.sub.3 M equivalent weight of from about 2,000 to about 100,000, and wherein M is selected from the group consisting of H.sup.+, NR.sub.4.sup.+ wherein R can be H.sup.+ or an alkyl group, Li.sup.+, Na.sup.+, K.sup.+, and mixtures thereof; (iii) at least two crosslinkable hydroxy groups pendant from the polyurethane backbone, wherein the polyurethane backbone has a hydroxy equivalent weight of from about 500 to about 50,000; and (iv) at least one --SD group pendant from the polyurethane backbone. The invention also relates to vinyl/polyurethane copolymers made therewith which are particularly useful as binders in magnetic recording media and a method of making the copolymers.
    Type: Grant
    Filed: July 21, 1992
    Date of Patent: June 8, 1993
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Ramesh C. Kumar, James G. Carlson, Jeffrey T. Anderson
  • Patent number: 5202190
    Abstract: A method of preparing vinyl-silicone copolymers which involves the use of a mercapto-functional silicone compound as a macromolecular chain transfer agent. Release coatings and low adhesion backsizes comprising the vinyl-silicone copolymers.
    Type: Grant
    Filed: March 18, 1992
    Date of Patent: April 13, 1993
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Steven S. Kantner, Ramesh C. Kumar, Gilbert L. Eian
  • Patent number: 5200436
    Abstract: The present invention provides novel siloxane iniferter compounds, block copolymers made therewith, and a method of making the block copolymers. The siloxane iniferter compounds can be represented by the formula ##STR1## wherein T and X are organic groups selected so that the T-X bond is capable of dissociating upon being subjected to an appropriate energy source to form a terminator free radical of the formula T.multidot. and an initiator free radical;R.sub.1, R.sub.2, R.sub.5 and R.sub.6 are monovalent moieties selected from the group consisting of hydrogen, C.sub.1-4 alkyl, C.sub.1-4 alkoxy and aryl which can be the same or are different;R.sub.3 and R.sub.4 are monovalent moieties which can be the same or different selected from the group consisting of hydrogen, C.sub.1-4 alkyl, C.sub.
    Type: Grant
    Filed: July 25, 1991
    Date of Patent: April 6, 1993
    Assignee: Minnesota Mining and Manufacture Company
    Inventors: Ramesh C. Kumar, Milton H. Andrus, Jr., Miecyzslaw H. Mazurek
  • Patent number: 5134035
    Abstract: The invention relates to a sulfonated, thiol, and hydroxy-functional polyurethane polymer which comprises: (i) a polyurethane backbone; (ii) at least one SO.sub.3 M group pendant from the polyurethane backbone, wherein the polyurethane backbone has an SO.sub.3 M equivalent weight of from about 2,000 to about 100,000, and wherein M is selected from the group consisting of H.sup.+, NR.sub.4.sup.+ wherein R can be H.sup.+ or an alkyl group, Li.sup.+, Na.sup.+, K.sup.+, and mixtures thereof; (iii) at least two crosslinkable hydroxy groups pendant from the polyurethane backbone, wherein the polyurethane backbone has a hydroxy equivalent weight of from about 500 to about 50,000; and (iv) at least one --SH group pendant from the polyurethane backbone. The invention also relates to vinyl/polyurethane copolymers made therewith which are particularly useful as binders in magnetic recording media and a method of making the copolymers.
    Type: Grant
    Filed: June 25, 1990
    Date of Patent: July 28, 1992
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Ramesh C. Kumar, James G. Carlson, Jeffrey T. Anderson
  • Patent number: 5089336
    Abstract: Iniferter prepared release coating compositions comprising vinyl-siloxane block copolymer and blends thereof with other polymeric materials on sheet materials and the backside of adhesive tapes are provided. Controlled and predictable release is obtained through variation of the molecular weight and weight percent of the siloxane block as well as the molecular weight and composition of the vinyl block or blocks.
    Type: Grant
    Filed: August 14, 1989
    Date of Patent: February 18, 1992
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Ramesh C. Kumar, Steven S. Kantner
  • Patent number: 5057619
    Abstract: The present invention provides novel siloxane iniferter compounds, block copolymers made therewith, and a method of making the block copolymers. The siloxane iniferter compounds can be represented by the formula ##STR1## wherein T and X are organic groups selected so that the T-X bond is capable of dissociating upon being subjected to an appropriate energy source to form a terminator free radical of the formula T and an initiator free radical.r.sub.1, R.sub.2, R.sub.5 and R.sub.6 are monovalent moieties selected from the group consisting of hydrogen, C.sub.1-4 alkyl, C.sub.1-4 alkoxy and aryl which can be the same or are different;R.sub.3 and R.sub.4 are monovalent moieties which can be the same or different selected from the group consisting of hydrogen, C.sub.1-4 alkyl, C.sub.
    Type: Grant
    Filed: February 26, 1991
    Date of Patent: October 15, 1991
    Assignee: Minnesota Mining and Manufacturing Co.
    Inventors: Ramesh C. Kumar, Milton H. Andrus, Jr., Mieczyslaw H. Mazurek
  • Patent number: 5032460
    Abstract: A method of preparing vinyl-silicone copolymers which involves the use of a mercapto-functional silicone compound as a macromolecular chain transfer agent. Release coatings and low adhesion backsizes comprising the vinyl-silicone copolymers.
    Type: Grant
    Filed: August 14, 1989
    Date of Patent: July 16, 1991
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Steven S. Kantner, Ramesh C. Kumar, Gilbert L. Eian