Patents by Inventor Sheau-Hwa Ma

Sheau-Hwa Ma 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).

  • Publication number: 20060003106
    Abstract: The present invention relates to a process for producing a multi-coat system on various substrates, particularly automotive bodies. A crosslinkable component of the composition includes an acid functional acrylic copolymer polymerized from a monomer mixture comprising 2 percent to 12 percent of one or more carboxylic acid group containing monomers, percentages based on total weight of the acid functional acrylic copolymer, and 0.2 percent to 2 percent of amorphous silica, percentages based on total weight of the crosslinkable component. The crosslinking component can includes polyisocyanates, melamines, or a combination thereof.
    Type: Application
    Filed: December 30, 2003
    Publication date: January 5, 2006
    Inventors: Sheau-Hwa Ma, James Matthews, Henry Tronco Jr.
  • Patent number: 6852803
    Abstract: A polymer dispersant for pigments based on a graft copolymer which contains a new type of urea functional group as the pigment anchoring group. The urea groups are attached to the graft copolymer by a convenient method which involves reaction of hydroxyl functional groups built in the graft copolymer with a diisocyanate that is capped at one end with ammonia or a primary or secondary amine. The reaction is convenient and clean. Substantial crosslinking or gelling of the polymer can be easily avoided by judicious selection of appropriate ingredients and processing conditions. These materials are effective in dispersing and stabilizing a wide range of pigments in solvent based systems and are particularly useful in forming pigment dispersions that are used in a variety of solvent borne coating compositions for automobiles and trucks, where they provide improved efficiency of pigment use, lower paint viscosity, and reduced emission of volatile organic solvent.
    Type: Grant
    Filed: June 3, 2002
    Date of Patent: February 8, 2005
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Sheau-Hwa Ma
  • Publication number: 20040131786
    Abstract: The present invention relates to a coating composition for coating various substrates, particularly automotive bodies. A crosslinkable component of the composition includes an acid functional acrylic copolymer polymerized from a monomer mixture comprising 2 percent to 12 percent of one or more carboxylic acid group containing monomers, percentages based on total weight of the acid functional acrylic copolymer, and 0.2 percent to 2 percent of amorphous silica, percentages based on total weight of the crosslinkable component. The crosslinking component can includes polyisocyanates, melamines, or a combination thereof.
    Type: Application
    Filed: October 29, 2003
    Publication date: July 8, 2004
    Inventors: Sheau-Hwa Ma, James F. Matthews, Henry A. Tronco
  • Publication number: 20040115357
    Abstract: The present invention relates to a process for producing a multi-coat system on various substrates, particularly automotive bodies. A crosslinkable component of the composition includes an acid functional acrylic copolymer polymerized from a monomer mixture comprising 2 percent to 12 percent of one or more carboxylic acid group containing monomers, percentages based on total weight of the acid functional acrylic copolymer, and 0.2 percent to 2 percent of amorphous silica, percentages based on total weight of the crosslinkable component. The crosslinking component can includes polyisocyanates, melamines, or a combination thereof.
    Type: Application
    Filed: October 29, 2003
    Publication date: June 17, 2004
    Inventors: Sheau-Hwa Ma, James F. Matthews, Henry A. Tronco
  • Publication number: 20030225207
    Abstract: A polymer dispersant for pigments based on a graft copolymer which contains a new type of urea functional group as the pigment anchoring group. The urea groups are attached to the graft copolymer by a convenient method which involves reaction of hydroxyl functional groups built in the graft copolymer with a diisocyanate that is capped at one end with ammonia or a primary or secondary amine. The reaction is convenient and clean. Substantial crosslinking or gelling of the polymer can be easily avoided by judicious selection of appropriate ingredients and processing conditions. These materials are effective in dispersing and stabilizing a wide range of pigments in solvent based systems and are particularly useful in forming pigment dispersions that are used in a variety of solvent borne coating compositions for automobiles and trucks, where they provide improved efficiency of pigment use, lower paint viscosity, and reduced emission of volatile organic solvent.
    Type: Application
    Filed: June 3, 2002
    Publication date: December 4, 2003
    Inventor: Sheau-Hwa Ma
  • Patent number: 6521715
    Abstract: A polymer dispersant for pigments based on an acrylic graft copolymer wherein the graft copolymer has a weight average molecular weight of 3,000-100,000 and comprises a polymeric backbone and macromonomer side chains attached to the backbone, wherein (1) the polymeric backbone is formed of polymerized ethylenically unsaturated monomers and (2) the side chains are macromonomers that are attached to the backbone at a single terminal point and are formed from polymerized ethylenically unsaturated monomers and have a weight average molecular weight of about 1,000-30,000 wherein the graft copolymer contains about 2 to 70% by weight, based on the weight of the graft copolymer, of polymerized ethylenically unsaturated monomers containing acetoacetate groups that are polymerized into the backbone, side chains, or both, and the acetoacetate groups are reacted with a primary amine to form a pendant acetoacetyl amine group on the graft copolymer which serves as the pigment anchoring group.
    Type: Grant
    Filed: August 22, 2000
    Date of Patent: February 18, 2003
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Sheau-Hwa Ma
  • Patent number: 6495618
    Abstract: A polymer dispersant for pigments based on a graft copolymer wherein the graft copolymer has a weight average molecular weight of at least 3000 and has 10 to 90% by weight of a polymeric backbone and 90 to 10% by weight of macromonomer side chains attached to the backbone and wherein at least 20% by weight of the polymeric backbone has attached thereto an amide group which serves as a pigment anchoring group. The backbone may also have attached thereto an additional pigment anchoring group selected from the group consisting of aromatic ester, aromatic amine, aliphatic amine, and quaternary ammonium groups, or mixtures thereof. These materials disperse a wide variety of pigments and are useful in solvent borne coatings where they can provide improved efficiency of pigment use, lower paint viscosity, and reduced emission of volatile organic solvent.
    Type: Grant
    Filed: December 17, 1999
    Date of Patent: December 17, 2002
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Sheau-Hwa Ma
  • Patent number: 6472463
    Abstract: A polymer dispersant for pigments based on an acrylic graft copolymer wherein the graft copolymer has a weight average molecular weight of at least 3000 and has 10 to 90% by weight of a polymeric backbone and 90 to 10% by weight of macromonomer side chains attached to the backbone and wherein the graft copolymer has at least about 1% by weight of a pigment anchoring group selected from the group consisting of an aromatic ester group, aromatic amine group, and quaternary ammonium group, or mixtures thereof, attached to the backbone or the macromonomer. These materials disperse a wide variety of pigments and are useful in solvent borne coatings where they can provide improved efficiency of pigment use, lower paint viscosity, and reduced emission of volatile organic solvent.
    Type: Grant
    Filed: December 17, 1999
    Date of Patent: October 29, 2002
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Sheau-Hwa Ma
  • Patent number: 6455628
    Abstract: A process for preparing an aqueous dispersion by wet milling an aqueous carrier medium, a particulate solid, and a polymeric dispersant; wherein the polymeric dispersant is a combination of at least 50% by weight of a block copolymer; and a random copolymer; and wherein the block and random copolymers are prepared from substantially the same monomers. This invention provides an easy dispersion process for particulate solids, in particular colorants such as pigments or disperse dyes, at higher loadings, and a reduction of dispersion time which improves the productivity. Resulting dispersions have particular utility as inks for ink-jet printers.
    Type: Grant
    Filed: October 1, 2001
    Date of Patent: September 24, 2002
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Sheau-Hwa Ma, Walter Raymond Hertler
  • Patent number: 6451950
    Abstract: A polymer dispersant for pigments based on a random copolymer wherein the copolymer has a weight average molecular weight of at least 3000 and comprises a polymeric backbone of primarily acrylic monomers wherein the backbone contains multiple pigment anchoring groups attached thereto including at least one amide group and one or more additional pigment anchoring groups selected from the group consisting of aromatic esters, aromatic amines, and quaternary ammonium salts. These materials disperse a wide variety of pigments and are useful in solvent borne coatings where they can provide improved efficiency of pigment use, lower paint viscosity, and reduced emission of volatile organic solvent.
    Type: Grant
    Filed: July 5, 2000
    Date of Patent: September 17, 2002
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Sheau-Hwa Ma
  • Patent number: 6433117
    Abstract: The present invention relates to aqueous ink jet inks containing a copolymer dispersant comprising at least one polymerized monomer having the general formula: CH2═C(R3)C(O)OXa(C2H4O)b—(C3H6O)c—R4 where a=0 or 1; when a=1, X is an akyl, aryl, or alkaryl diradical connecting group of 1-9 carbon atoms; b and c are independently selected from the range of 0-100 provided that b and c are not simultaneously 0; R3 is H or CH3; and R4 is preferably PO3H2.
    Type: Grant
    Filed: August 4, 1999
    Date of Patent: August 13, 2002
    Assignee: E. I. du Pont de Nemours & Company
    Inventors: Sheau-Hwa Ma, Edward Francis McBride
  • Publication number: 20020035173
    Abstract: A process for preparing an aqueous dispersion by wet milling an aqueous carrier medium, a particulate solid, and a polymeric dispersant; wherein the polymeric dispersant is a combination of at least 50% by weight of a block copolymer; and a random copolymer; and wherein the block and random copolymers are prepared from substantially the same monomers. This invention provides an easy dispersion process for particulate solids, in particular colorants such as pigments or disperse dyes, at higher loadings, and a reduction of dispersion time which improves the productivity. Resulting dispersions have particular utility as inks for ink-jet printers.
    Type: Application
    Filed: October 1, 2001
    Publication date: March 21, 2002
    Inventors: Sheau-Hwa Ma, Walter Raymond Hertler
  • Patent number: 6306994
    Abstract: The present invention relates to block copolymer dispersants comprising a hydrophobic block and a hydrophilic block having at least one polymerized monomer including a primary amine functionality. The inventive block copolymer dispersant is used to make aqueous dispersants such as inks that have enhanced paper binding characteristics.
    Type: Grant
    Filed: May 14, 1999
    Date of Patent: October 23, 2001
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Dennis Scott Donald, Walter Raymond Hertler, Sheau-Hwa Ma
  • Patent number: 6232369
    Abstract: An ink for ink jet printers contains an aqueous carrier medium; an aqueous carrier medium insoluble colorant; a polymeric dispersant; and a hydrosol polymer is stable, exhibits excellent print quality, and provides excellent smear resistance after drying and good decap or crusting time.
    Type: Grant
    Filed: December 27, 1996
    Date of Patent: May 15, 2001
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Sheau-Hwa Ma, Waifong Liew Anton
  • Patent number: 6117921
    Abstract: Dispersions of an aqueous carrier medium, an insoluble particle, and a graft copolymer dispersant having backbone and side chain portions wherein both portions are prepared from ethylenically unsaturated monomers and either the backbone or sidechain portion is hydrophilic and the other portion is hydrophobic. In a preferred embodiment, the dispersion is formulated as an ink that exhibits excellent resistance to flocculation and provides images with a high color strength and gloss when used in a thermal ink jet printer.
    Type: Grant
    Filed: August 30, 1996
    Date of Patent: September 12, 2000
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Sheau-Hwa Ma, Michael Fryd
  • Patent number: 6037390
    Abstract: An ink jet ink composition is provided which contains an aqueous vehicle; a colorant; and a polymeric dispersant comprising 2 to 50% by weight of monomers selected from .beta.-diketone containing monomers and ureido monomers, as well as a combination of such ink with a media having basic groups such as primary or secondary amines and divalent cations.
    Type: Grant
    Filed: December 31, 1997
    Date of Patent: March 14, 2000
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Loretta Ann Grezzo Page, Sheau-Hwa Ma, John A. Simms
  • Patent number: 6020400
    Abstract: Inks for ink jet printers containing an aqueous carrier medium; a pigment; a polymeric dispersant; and an emulsion polymer additive stabilized with a structured polymer are stable, have low viscosity, exhibit excellent print quality, provide excellent smear resistance after drying, have good decap and crusting time, and also demonstrate good charging stability when used in continuous flow printers.
    Type: Grant
    Filed: December 27, 1996
    Date of Patent: February 1, 2000
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Waifong Liew Anton, Milan Bohuslav Bednarek, Robert Paul Held, Sheau-Hwa Ma, Joseph Edward Reardon, Arthur Charles Shor, Harry Joseph Spinelli, Soodabeh Tronson
  • Patent number: 5854331
    Abstract: Aqueous dispersions having improved stability and which are particularly well suited for use as aqueous ink jet ink compositions comprise an aqueous vehicle which comprises water or a mixture of water and an organic solvent; a particulate solid, preferably a pigment; and a polyoxazoline or polyoxazine dispersant selected from the group of AB, ABA, and BAB block copolymers wherein the A block is hydrophobic, and the B block is hydrophilic, and wherein the polymer as a whole has a solubility in the aqueous vehicle of at least 0.1 wt % at 25.degree. C.
    Type: Grant
    Filed: November 4, 1997
    Date of Patent: December 29, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: Sheau-Hwa Ma, Jose N. Rodriguez-Parada
  • Patent number: 5801738
    Abstract: A process for alleviating bleed and improving color in printed elements comprises applying an anionic printing liquid and a cationic printing liquid to a substrate adjacent to one another, wherein at least one of the printing liquids contains a polymer and reacting the anionic and cationic printing liquids with one another; wherein the color integrity of the anionic and cationic printing liquids is maintained.
    Type: Grant
    Filed: February 15, 1996
    Date of Patent: September 1, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: John Lawrence Stoffel, Arthur Charles Shor, Harry Joseph Spinelli, Sheau-Hwa Ma, Howard Matrick, Mark Leland Choy, Loren Eugene Johnson
  • Patent number: 5721330
    Abstract: A macromonomer composition, wherein at least 80 mol % of the macromonomer is a random copolymer of 2 to 1,000 units of monomers and having a very high content of acid monomers, i.e. >50% by weight of acid monomers, and an end group linked to the random copolymer having the formula:CH.sub.2 .dbd.C(C(O)OR.sub.1)(CH.sub.2 .paren close-st.,wherein R.sub.1 is selected from the group consisting essentially of H; an alkyl group of 1 to 8 carbon atoms; and X.sub.n (CH.sub.2 CH.sub.2 O).sub.m --R.sub.4 wherein n is 0 or 1, X is an alkyl, aryl or alkaryl diradical connecting group of 1 to 9 carbon atoms, m is 2 to 50, and R.sub.4 is H or an alkyl group of 1 to 4 carbon atoms. These macromonomers can be used effectively in solution form to prepare structured polymers such as block copolymers and graft copolymers for industrial applications.
    Type: Grant
    Filed: December 15, 1995
    Date of Patent: February 24, 1998
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Sheau-Hwa Ma