Patents by Inventor Yunn H. Chiang

Yunn H. Chiang 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: 5380695
    Abstract: An image-receiving element and a method of using same in the production of images by thermal dye transfer processing, the image-receiving element comprising a support, a polymeric security layer having a printed security layer, and an image-receiving layer for receiving dye by thermal transfer from a dye donor sheet, the polymeric security layer having cohesivity less than its adhesivity for each layer contiguous and the printed security pattern being destroyed by an attempted delamination of the image-receiving layer from the image-receiving element.
    Type: Grant
    Filed: April 22, 1994
    Date of Patent: January 10, 1995
    Assignee: Polaroid Corporation
    Inventors: Yunn H. Chiang, Russell A. Gaudiana
  • Patent number: 5141669
    Abstract: Liquid crystal compounds which show a ferroelectric phase and which exhibit high spontaneous polarization values and smectic behavior over a range of temperatures have the formula ##STR1## wherein R.sup.1 is alkyl of from 1 to 16 carbon atoms; alkoxy; haloalkyl; alkoxyalkyl, wherein the alkoxy substituent thereof comprises a chain of carbon atoms including one or more oxygen ether atoms; or alkoxyalkoxy, wherein the alkoxy substituent thereof comprises a chain of carbon atoms including one or more oxygen ether atoms; R.sup.2 is alkyl of from 1 to 4 carbon atoms; each of R.sup.3 and R.sup.4 is alkylene; n is an integer 1 or 2; and W is alkyl of from 1 to 12 carbon atoms or fluoroalkyl of the formula ##STR2## wherein each of X, Y and Z is hydrogen or fluorine, m is zero or an integer from 1 to 6, and at least one of X, Y and Z is fluorine when m is zero.
    Type: Grant
    Filed: June 30, 1989
    Date of Patent: August 25, 1992
    Assignee: Polaroid Corporation
    Inventors: Iris B. K. Bloom, Yunn H. Chiang, William J. Cumming, Russell A. Gaudiana, Richard A. Minns
  • Patent number: 5024989
    Abstract: A process for thermal imaging uses a donor sheet and a receiving sheet. The donor sheet comprises a support and a dye capable of being transferred by heat, while the receiving sheet is adapted to receive the dye and thereby form an image. The donor and receiving sheets are placed adjacent one another, and at least one of the adjacent faces of the donor and receiving sheets has a layer of a polymeric liquid crystal thereon. Selected portions of the donor sheet are heated so as to transfer dye from the donor sheet to the receiving sheet, thereby forming an image on the receiving sheet.
    Type: Grant
    Filed: April 25, 1990
    Date of Patent: June 18, 1991
    Assignee: Polaroid Corporation
    Inventors: Yunn H. Chiang, Russell A. Gaudiana
  • Patent number: 4405781
    Abstract: There is described a novel method for preparing and isolating novel salts of 6-chloropurine and strong acids. According to the method hypoxanthine is reacted with phosphorus oxychloride in the presence of an organic base to form 6-chloropurine, a solvent is added to the reaction mixture and the latter is reacted with a strong acid to form a 6-chloropurine salt which is then isolated. In a preferred embodiment 6-chloropurine is freed from the salt with water, preferably in the presence of a base. In another preferred embodiment the 6-chloropurine is aminated with various amines.
    Type: Grant
    Filed: March 2, 1981
    Date of Patent: September 20, 1983
    Assignee: Polaroid Corporation
    Inventors: Henry Bader, Yunn H. Chiang
  • Patent number: 4195038
    Abstract: Bromination of large batches of 2,6-dimethyl-2,5-heptadiene-4-one below -20.degree. C. followed by dehydrobromination without intermediate isolation and recrystallization to produce 3,5-dibromo-2,6-dimethyl-2,5-heptadiene-4-one which can be cyclized without isolation to high yields of 3-bromo-2-hydroxy-4,4,5,5-tetramethylcyclopenta-2-enone is disclosed.
    Type: Grant
    Filed: September 1, 1978
    Date of Patent: March 25, 1980
    Assignee: Polaroid Corporation
    Inventor: Yunn H. Chiang
  • Patent number: 4180513
    Abstract: There is described a method for the synthesis of Acid Blue Dye 104 (Color Index. No. 42735) wherein N-benzyl-N-ethyl-toluidinesulfonic acid is reacted with p-diethylaminobenzaldehyde to form leuco Acid Blue Dye 104 which is then isolated and purified with a solvent such as a lower alcohol to provide a very high purity product. The leuco dye is dissolved in a buffer solution of acetic acid and oxalic acid and oxidized by rapidly adding sodium dichromate solution. The Acid Blue Dye is collected and purified to obtain a final product of very high purity and optical transparency.
    Type: Grant
    Filed: July 17, 1978
    Date of Patent: December 25, 1979
    Assignee: Polaroid Corporation
    Inventor: Yunn H. Chiang
  • Patent number: 3983137
    Abstract: This invention is concerned with a novel class of protonated compounds, namely, 3-(indol-3-yl)dehydronaphthalide hydrochlorides, with their synthesis by the reaction of a 3-(indol-3-yl)naphthalide and a high-potential quinone in an inert anhydrous aprotic solvent in the presence of a carboxylic acid catalyst, and with the synthesis of indole naphthalide indicator dyes by reacting the said dehydronaphthalide hydrochlorides and an indole in an aromatic hydrocarbon solvent in the presence of a carboxylic acid catalyst.
    Type: Grant
    Filed: September 4, 1975
    Date of Patent: September 28, 1976
    Assignee: Polaroid Corporation
    Inventor: Yunn H. Chiang
  • Patent number: 3933854
    Abstract: This invention is concerned with a novel class of protonated compounds, namely, 3-(indol-3-yl)dehydronaphthalide hydrochlorides, with their synthesis by the reaction of a 3-(indol-3-yl)naphthalide and a high-potential quinone in an inert anhydrous aprotic solvent in the presence of a carboxylic acid catalyst, and with the synthesis of indole naphthalide indicator dyes by reacting the said dehydronaphthalide hydrochlorides and an indole in an aromatic hydrocarbon solvent in the presence of a carboxylic acid catalyst.
    Type: Grant
    Filed: December 3, 1973
    Date of Patent: January 20, 1976
    Assignee: Polaroid Corporation
    Inventor: Yunn H. Chiang