Patents by Inventor Lester T. C. Lee

Lester T. C. Lee 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: 4550150
    Abstract: Process of detecting the presence of certain gases, including certain pollutants, in small concentrations; or to cause partial polymerization of certain polyacetylene compositions for use in time/temperature history indicators or radiation dosage indicators. The process involves contacting a reactive gas, such as a nitrogen oxide, a halide or ozone, with a crystalline substituted acetylenic monomer containing at least two conjugated triple bonds and substituents having at least one atom of oxygen or nitrogen. In particular the acetylenic compound is 2,4-hexadiyne-1,6-bis(phenylurethane) crystallized from tetrahydrofuran or acetone.
    Type: Grant
    Filed: November 19, 1980
    Date of Patent: October 29, 1985
    Assignee: Allied Corporation
    Inventors: Gordhanbhai N. Patel, Anthony F. Preziosi, Himangshu R. Bhattacharjee, Lester T. C. Lee
  • Patent number: 4355116
    Abstract: Stable single film bipolar membranes of prolonged life and improved performance particularly for use in electrodialysis water splitting process, are prepared by introducing a more stable interface in the membrane structure. After the cationic exchange groups are preformed on an insoluble cross-linked aromatic polymeric matrix, the dissociable anionic exchange groups may be introduced more intimately chemically bonded in position by using multi-functional compounds containing mixed tertiary, secondary and primary amine groups, so that the resulting interface is comparatively more stable, and is less likely to be neutralized, therefore, attaining longer life-time and a higher level of performance.
    Type: Grant
    Filed: December 29, 1980
    Date of Patent: October 19, 1982
    Assignee: Allied Corporation
    Inventors: Lester T. C. Lee, Kang-Jen Liu
  • Patent number: 4336356
    Abstract: Partially unsaturated polymers are dissolved in a two component solvent comprising a first component having a reactivity toward ozone less than carbon-carbon double bonds but more reactive than carbon-carbon single bonds and a second component being inert toward ozone. Introduction of ozone into the solution produces ozonides which are readily cleft into difunctional aliphatic species that can be converted to e.g. carboxy-terminated or multifunctional carboxy substituted aliphatic compounds. These may be used as monomeric species in various polymerization schemes as such, in preparation of polyamides, for example, or may be reduced to aldehydes or alcohols to be used in the preparation of such polymers as polyesters, polyurethanes, poly (Schiff bases), etc. The carboxylated products may also be employed as ionomers, which are useful as surfactants. Monocarboxyl terminated polyethylene having a number average molecular weight of from about 4,000 to 100,000 are provided.
    Type: Grant
    Filed: August 25, 1980
    Date of Patent: June 22, 1982
    Assignee: Allied Corporation
    Inventors: Shaul M. Aharoni, Dusan C. Prevorsek, George J. Schmitt, Gary A. Harpell, Lester T. C. Lee
  • Patent number: 4253900
    Abstract: Superior bipolar membranes are prepared having high performances. The improvement is achieved by (1) using high performance component ion exchange membranes, and (2) controlling the method of joining two component membranes into a bipolar membrane. The method of preparation of high performance component ion exchange membranes is also disclosed.
    Type: Grant
    Filed: February 28, 1977
    Date of Patent: March 3, 1981
    Assignee: Allied Chemical Corporation
    Inventors: Gerald J. Dege, Frederick P. Chlanda, Lester T. C. Lee, Kang-Jen Liu
  • Patent number: 4116889
    Abstract: Stable bipolar membranes of high permselectivity and low potential drop are prepared using either an anion or cation preformed first layer upon which a second layer or coating of an ion exchange resin of the opposite charge carried in a matrix polymer is applied. The second layer may be suitably applied such as by casting as a slurry of the ion exchange resin in a solution or by laminating a layer comprising a dispersion of the resin in a solid or fused polymer. Optionally, the surface of the first layer may be treated to increase the resin concentration and/or bonding at the interface, such as by sanding, etching, etc.
    Type: Grant
    Filed: August 19, 1976
    Date of Patent: September 26, 1978
    Assignee: Allied Chemical Corporation
    Inventors: Frederick P. Chlanda, Lester T. C. Lee, Kang-Jen Liu
  • Patent number: 4083768
    Abstract: Novel polyelectrolyte membranes of substantially improved efficiency and durability are prepared from a preswollen film containing a relatively high amount of an insoluble cross-linked aromatic polymer. By preswelling the insoluble matrix under controlled conditions preferably to an equilibrium stage, the dissociable ion-exchange groups may be introduced more uniformly onto the aromatic nuclei of the matrix to a desired depth of the film. Controlled penetration of functional groups is important in preparing high performance cationic, anionic membranes as well as bipolar membranes. The membranes so prepared have low electrical resistance, improved current efficiency, undergo negligible degradation and with excellent durability.
    Type: Grant
    Filed: May 24, 1976
    Date of Patent: April 11, 1978
    Assignee: Allied Chemical Corporation
    Inventors: Lester T. C. Lee, Kang-Jen Liu
  • Patent number: 4057481
    Abstract: Improved novel single film bipolar membranes having an ion selectivity above 80% in an electrolyte medium of about one mole, are prepared containing a relatively high amount, i.e. at least 15% of an insoluble cross-linked aromatic polymer. Before the styrenated sheet is chemically functionalized, the film surface is specifically treated, i.e. cleaned to make it more receptive to functional groups, so that the cationic-exchange groups and anion-exchange groups can be introduced homogeneously from each side of the surface-cleaned film, and a single-film bipolar membrane of superior durability, stability, and quality control results.
    Type: Grant
    Filed: May 24, 1976
    Date of Patent: November 8, 1977
    Assignee: Allied Chemical Corporation
    Inventors: Lester T. C. Lee, Gerald J. Dege, Kang-Jen Liu
  • Patent number: 4024185
    Abstract: Novel cycloaliphatic diamines have been prepared which are consisting of two unequivalent amine groups. The diamines are prepared by reduction of aromatic dinitro compounds. The polyamides made from these diamines are useful in forming fibers and films having excellent high temperature properties.
    Type: Grant
    Filed: December 4, 1974
    Date of Patent: May 17, 1977
    Assignee: Allied Chemical Corporation
    Inventor: Lester T. C. Lee
  • Patent number: 3957504
    Abstract: A system utilizing membrane extraction is provided to recover metal values. The system may be used to separate metal ions from an aqueous solution through the membrane by an organic liquid containing a chelating agent. This invention also contemplates the recovery of metal values from an organic phase, containing the metal complexed with a chelating agent, by an aqueous phase using membrane extraction. In the former case, the metal ion is passed through the membrane from the aqueous phase to the organic phase where it forms a complex with a chelating agent present in the organic phase. In the latter case the metal is extracted from the organic phase into the aqueous phase through the membrane. In both cases a chelating exchange reaction is involved at the interface between the membrane and one of the two phases. This hydro-metallurgical process employs membranes with metal ion diffusivity in the range of about 10.sup..sup.-5 to about 10.sup..sup.-8 cm.sup.2 /sec.
    Type: Grant
    Filed: November 11, 1974
    Date of Patent: May 18, 1976
    Assignee: Allied Chemical Corporation
    Inventors: Win-Sow Ho, Lester T. C. Lee, Kang-Jen Liu
  • Patent number: 3956112
    Abstract: A membrane solvent extraction system is utilized to separate two substantially immiscible liquids and extract a solute through a solvent swollen membrane from one solvent liquid phase to the extracting solvent liquid without direct contact between the liquid phases. The membrane extraction method has advantages over conventional solvent extraction and may be applied as the mechanism in separation, purification, pollutant removal and recovery processes.
    Type: Grant
    Filed: March 13, 1975
    Date of Patent: May 11, 1976
    Assignee: Allied Chemical Corporation
    Inventors: Lester T. C. Lee, Win-Sow Ho, Kang-Jen Liu
  • Patent number: 3951789
    Abstract: Novel membrane compositions are prepared from polymers comprising tertiary amine containing polyamideamine functional groups. The membranes are durable, highly selective and have excellent homogeneity and high diffusivity. Asymmetric membranes can be prepared by solution casting or melt processing techniques can be used to produce homogeneous, high performance, symmetric membranes. The specific compositions of the membranes can be adjusted so as to achieve a membrane possessing a required degree of hydrophilicity and porosity. These membranes may be used in a variety of separation applications, particularly in two-phase solvent extraction.
    Type: Grant
    Filed: October 11, 1973
    Date of Patent: April 20, 1976
    Assignee: Allied Chemical Corporation
    Inventors: Lester T. C. Lee, Win-Sow Ho, Kang-Jen Liu
  • Patent number: 3948823
    Abstract: Novel cross-linked interpolymer membranes of substantially improved efficiency and durability are prepared from a co-mixture of a hydrophilic polymer of [1, .omega.-alkylene(2,6-diketopiperazine)-1,4-dicarboxamide] and a hydrophobic polymer such as polyvinylidene fluoride, by dissolving these polymers in a suitable solvent, forming films of suitable thickness from the solution and thereafter preferably crosslinking the dissolved mixture.
    Type: Grant
    Filed: August 1, 1972
    Date of Patent: April 6, 1976
    Assignee: Allied Chemical Corporation
    Inventors: Lester T. C. Lee, Kang-Jen Liu