Patents Assigned to National Patent Development Corporation
  • Patent number: 4003991
    Abstract: An ophthalmic "ointment" comprising water, a solid water-soluble polymer of controlled molecular weight, and a medicament or therapeutic agent such as pilocarpine in its pharmacologically acceptable salts.
    Type: Grant
    Filed: August 27, 1974
    Date of Patent: January 18, 1977
    Assignee: National Patent Development Corporation
    Inventors: David L. Krohn, Samuel H. Ronel
  • Patent number: 3998945
    Abstract: N-haloamines also containing a hydroxy group, a sulfonic acid group, and N-acyl group or a carboxylic acid group are useful in treating teeth to remove caries, dissolve or remove plaque, to help in the prevention of calculus formation and in the brightening of teeth. The compounds can be used in solution or in carrier form as a paste.
    Type: Grant
    Filed: June 24, 1975
    Date of Patent: December 21, 1976
    Assignee: National Patent Development Corporation
    Inventor: Jeroslav Vit
  • Patent number: 3990381
    Abstract: Hydrophilic polymers, i.e., hydrophilic cellulose esters, hydrophilic cellulose ethers, hydrophilic polyurethanes, hydrophilic vinyl lower alkyl ether polymers, vinyl alcohol group containing polymers, partially hydrolized polyacrylonitrite, ethylene-maleic anhydride copolymer, stryene-maleic anhydride copolymer, proteins, high molecular weight polyalkylene oxides or phenoxy resins, having encapsulated therein either or both anti-fouling agents or pigments is applied as a coating to underwater portions of a marine structure so as to reduce the drag of said structure.
    Type: Grant
    Filed: September 27, 1974
    Date of Patent: November 9, 1976
    Assignee: National Patent Development Corporation
    Inventors: Thomas H. Shepherd, Francis E. Gould
  • Patent number: 3991107
    Abstract: N-haloamines also containing a hydroxy group, a sulfonic acid group, an N-acyl group or a carboxylic acid group are prepared by reacting an amine with a different N-haloamine to form the N-haloamine of the free amine.
    Type: Grant
    Filed: October 26, 1972
    Date of Patent: November 9, 1976
    Assignee: National Patent Development Corporation
    Inventor: Jaroslav Vit
  • Patent number: 3963495
    Abstract: An image-receiving material for silver salt diffusion transfer process having at least two layers wherein (I) a polymer layer containing diffusible compound, which can change the property of silver image formed in a binder layer containing silver deposition nuclei, and (II) the binder layer containing silver deposition nuclei on said polymer layer are provided on support, said polymer layer comprising at least one water insoluble hydrophilic polymer selected from the group consisting of homopolymers, copolymers and graft polymers of monoacrylates of polyhydric alcohols and homopolymers, copolymers and graft polymers of monomethacrylates of polyhydric alcohols.
    Type: Grant
    Filed: March 20, 1974
    Date of Patent: June 15, 1976
    Assignees: Fuji Photo Film Co., Ltd., National Patent Development Corporation
    Inventors: Kazunobu Kato, Shinji Sakaguchi
  • Patent number: 3941858
    Abstract: A process for preparing hydrophilic cross-linked polymers and products prepared thereby, said process comprising admixing in a solvent-free system in the presence of a free radical, vinyl polymerization catalyst and reacting a major amount of a water-soluble polymerizable monoester of an olefinic acid having at least one substituted functional group with a minor amount of a polymerizable diester of one of said olefinic acids having at least two esterifiable hydroxyl groups. The novel products include a solid friable foam which can be disintegrated to powder. Shaped bodies can be prepared in the form of articles which can be cast with additives such as fragrances, medicinals, flavors, chemicals and the like, which are gradually released from the article when it is wetted in water or alcohol. Liquid casting syrups adapted to be polymerized in situ with or without additives can be formed.
    Type: Grant
    Filed: August 7, 1973
    Date of Patent: March 2, 1976
    Assignee: National Patent Development Corporation
    Inventors: Thomas H. Shepherd, Francis E. Gould
  • Patent number: 3935368
    Abstract: A hydrophilic hydroxyalkyl or lower alkoxyalkyl acrylate or methacrylate polymer is employed as a protective coating for a vinyl chloride resin or polymer flooring material. A glossy surface is produced which can be maintained by buffing without waxing. Improved soil and stain resistance are also imparted to the flooring.
    Type: Grant
    Filed: July 1, 1971
    Date of Patent: January 27, 1976
    Assignee: National Patent Development Corporation
    Inventor: Jonas Weiss