Patents by Inventor Paul N. Chen, Sr.

Paul N. Chen, Sr. 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: 5739193
    Abstract: A polymeric composition having a high dielectric constant which varies little with temperature is made from a thermoplastic polymer, a high dielectric ceramic having a dielectric constant of at least about 50 at 1.0 Ghz and 20.degree. C., and a second ceramic material having a dielectric constant of at least about 5.0 at 1.0 GHz and 20.degree. C., where the high dielectric ceramic and the second ceramic material have temperature coefficients that are opposite in sign from one another.
    Type: Grant
    Filed: May 7, 1996
    Date of Patent: April 14, 1998
    Assignee: Hoechst Celanese Corp.
    Inventors: Lak M. Walpita, Paul N. Chen, Sr., Harris A. Goldberg, Christopher Zipp
  • Patent number: 5695710
    Abstract: A process for making a transparent blow molded product made of a copolyester of PET and PEN that does not thermally deform at temperatures up to 85-87 C., and the product of that process, especially a transparent blow molded bottle. The copolyester is made by transesterifying a 20/80 (w/w) PEN/PET via melt extrusion at a temperature of from about 250 C. to about 290 C. for a time sufficient to produce about 1-20% transesterification of said polymers, forming a copolymer. The copolyester is then injection molded at a temperature of from 290 C. to about 320 C. to form a transparent preform in which the copolymer has a glass transition temperature of about 85 C. or higher and a melting point temperature of at least about 225 C. The copolymer is then thermo-stretch blow molded to form a transparent product.
    Type: Grant
    Filed: May 9, 1995
    Date of Patent: December 9, 1997
    Assignee: Hoechst Celanese Corp.
    Inventors: Paul N. Chen, Sr., Kenith P. Music, Gerald W. McNeely
  • Patent number: 5308909
    Abstract: A moldable hollow glass filled PBI composition. The composition may be prepared by making a well-mixed slurry of glass microspheres in a solution of PBI in a suitable solvent, and then spinning the slurry through a jet or die under pressure and into a water bath where the particles coagulate. The solvent dissolves in the water, allowing solvent-free PBI-glass composite particles to be isolated.
    Type: Grant
    Filed: February 19, 1993
    Date of Patent: May 3, 1994
    Assignee: Hoechst Celanese Corp
    Inventors: Paul N. Chen, Sr., Victor C. Astone, William M. Cooper, O. Richard Hughes
  • Patent number: 5216073
    Abstract: A moldable thermoset composition comprising about 5-60% liquid crystal polymer and about 95-40% of an epoxy-functional rubber by weight, a process for making and a process for using same. The composition is made by melt mixing the LCP and the epoxy-rubber to form a blend. This blend is then cooled and may be molded, extruded, or otherwise formed into a desired shape. The composition is then heat-treated to make it set.
    Type: Grant
    Filed: July 1, 1992
    Date of Patent: June 1, 1993
    Assignee: Hoechst Celanese Corp.
    Inventors: M. Ishaq Haider, Vincent J. Sullivan, Paul N. Chen, Sr., Harry S. Pulaski
  • Patent number: 5173541
    Abstract: A graft copolymer having a polyolefinic main chain with muconic acid groups pendant therefrom. The acid groups are bonded to the backbone of the polyolefin by free radical addition across a muconic acid double bond. Preferably, the copolymer is prepared via a reactive extrusion process. The copolymer's applications include use as a reactive compatibilizer for polymer blends. The preferred polyolefin is polypropylene.
    Type: Grant
    Filed: December 5, 1990
    Date of Patent: December 22, 1992
    Assignee: Hoechst Celanese Corp.
    Inventors: Paul N. Chen, Sr., Morton M. Glick, Michael M. Jaffe, Alex Forschirm
  • Patent number: 5137985
    Abstract: A miscible blend comprising from about 5 to about 95 weight percent of a polybenzimidazole and from about 95 to about 5 weight percent of a polyamide-imide having fluorine-containing linking groups, total weight percent of the two polymers being 100. A process for preparing the blends comprises dissolving in a mutual solvent from about 5 to about 95 weight percent of the aromatic polybenzimidazole to about 95 to about 5 weight percent of the polyamide-imide having fluorine-containing linking groups, based on the total weight of those polymers and subsequently evaporating the solvent, thereby producing a dried blend of a polybenzimidazole and a polyamide-imide having fluorine-containing linking groups. The blends, particularly in the form of films, fibers or fibrets, may be post-treated with heat or sulfuric acid in order to minimize their shrinkage when subsequently subjected to heat and in order to increase their resistance to solvents and acid.
    Type: Grant
    Filed: September 22, 1989
    Date of Patent: August 11, 1992
    Assignee: Hoechst Celanese Corp.
    Inventors: Paul N. Chen, Sr., Morton Glick, Rohitkumar H. Vora, Michael Jaffe
  • Patent number: 5120825
    Abstract: The present invention provides for hybrid polybenzimidazole and polybenzimidazolone polymers which are characterized as containing both imidazole and imidazolone structural units in the polymer chain. These polymers are characterized as containing at least one recurring monomer unit containing the structure of the formula: ##STR1## wherein Ar is a tetravalent aromatic moiety derived from an aromatic tetraamine and Ar.sub.1 is a trivalent aromatic moiety derived from a trifunctional acid, an acid anhydride or amine-reactive derivatives thereof, said polymers further characterized by an inherent viscosity of at least about 0.01 dl/g measured as a 0.5% solution in N-methyl pyrrolidone at 25.degree. C.The polymers of this invention exhibit many of the advantageous properties of both polybenzimidazole and polybenzimidazolone polymers. They are characterized as being extremely resistant to chemical attack such as by solvents, acids and bases.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: June 9, 1992
    Assignee: Hoechst Celanese Corp.
    Inventors: Rohitkumar H. Vora, Paul N. Chen, Sr.
  • Patent number: 5120826
    Abstract: The present invention provides for a novel heat stable class of polyamide-imide polymers having excellent flow properties and hydrolytic stability which are prepared by forming the polycondensation product of one or more aromatic or aliphatic diamines and a comonomer comprising a tri- or hexafluoro-substituted tricarboxylic acid anhydride (or acid derivative thereof) having the structure: ##STR1## wherein R is CF.sub.3 or a phenyl radical. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, good resistance to attack by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as good thermal properties, including resistance to thermooxidative degradation.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: June 9, 1992
    Assignee: Hoechst Celanese Corp.
    Inventors: Rohitkumar H. Vora, Paul N. Chen, Sr.
  • Patent number: 5109107
    Abstract: The present invention provides for a novel heat stable class of polyamide-imide polymers having excellent flow properties and hydrolytic stability which are prepared by forming the polycondensation product of one or more aromatic or aliphatic diamines, one or more additional comonomers selected from the group consisting of a tetrafunctional aromatic dianhydride, an aromatic or aliphatic dicarboxylic acid (or acid derivative thereof) and mixtures thereof, and a comonomer comprising a tri- or hexafluoro-substituted tricarboxylic acid anhydride (or acid derivative thereof) having the structure: ##STR1## wherein Z is CF.sub.3 or a phenyl radical.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: April 28, 1992
    Assignee: Hoecht Celanese Corp.
    Inventors: Rohitkumar H. Vora, Paul N. Chen, Sr.
  • Patent number: 5077383
    Abstract: New polybenzimidazolone polymers produced from the reaction of an aromatic tetraamine with a hexafluoro dianhydride. These hexafluoro polybenzimidazolone polymers based on an aromatic hexafluoro dianhydrides show improved solubility, easy processability, low moisture uptake, high thermal stability, resistance to solvent and other improvements over conventional polybenzimidazolone polymers.
    Type: Grant
    Filed: March 15, 1990
    Date of Patent: December 31, 1991
    Assignee: Hoechst Celanese Corp.
    Inventors: Rohitkumar H. Vora, Paul N. Chen, Sr., Joseph D. Menczel
  • Patent number: 5070144
    Abstract: A compatible polymer blend containing a polyacetal, a hydroxylated polyacetal, polypropylene, and an acid-grafted polyolefine such as a muconic acid-polypropylene graft copolymer. The polyacetal is preferably a polyoxymethylene polymer such as Celcon.RTM.. The preferred hydroxylated polyacetal is one having a structure very similar to the polyacetal. The invention also includes a process for forming a compatible blend containing polypropylene and polyacetal by melt mixing polypropylene and polyacetal with an acid grafted polyolefin and hydroxylated polyacetal.
    Type: Grant
    Filed: December 5, 1990
    Date of Patent: December 3, 1991
    Assignee: Hoechst Celanese Corp.
    Inventors: Paul N. Chen, Sr., Alex Forschirm, Morton Glick, Michael Jaffe
  • Patent number: 5025089
    Abstract: Copolyimides derived from the reaction product of 3,3'-6 F diamine or 4,4'-6 F diamine, at least one other diamine, and pyromellitic dianhydride can be rendered solvent soluble while at the same time exhibiting an improvement in both mechanical and electrical properties by the inclusion of at least one other dianhydride having a diaryl nucleus in the reaction media. Suitable such dianhydrides include bis (3,4 dicarboxy phenyl) ether dianhydride, 3,3'4,4' benzophenone tetracarboxylic dianhydride, 3,3',4,4' diphenyl tetracarboxylic acid dianhydride and 2,2 bis(3,4 dicarboxyphenyl) hexafluoropropane dianhydride (6F-DA). Such polyimides are soluble in common organic solvents such as methyl ethyl ketone or N-methyl pyrrolidone, and exhibit excellent film forming properties with improved mechanical and electrical properties as compared to the corresponding homopolyimides. They possess excellent heat stability (Tg's in excess of about 350.degree. C.
    Type: Grant
    Filed: November 13, 1989
    Date of Patent: June 18, 1991
    Assignee: Hoechst Celanese Corp.
    Inventors: Rohitkumar H. Vora, Paul N. Chen, Sr.
  • Patent number: 4963434
    Abstract: A composite comprising a polyarylate or an aromatic polybenzimidazole article and a coating on at least one surface of the article comprised of a blend of from about 5 to about 95 weight percent of a polyarylate and from about 95 to about 5 weight percent of an aromatic polybenzimidazole. A process for preparing the composites comprises dissolving in a mutual solvent from about 5 to about 95 weight percent of the aromatic polybenzimidazole to about 95 to about 5 weight percent of the polyarylate, based on the total weight of those polymers, heating a polyarylate or aromatic polybenzimidazole article to a surface temperature over 100.degree. C., e.g., from about 120.degree. C., to about 180.degree. C., and then coating the polyarylate or aromatic polybenzimidazole article with the solution and subsequently evaporating the solvent, thereby producing a dried coating of a blend of a polyarylate and an aromatic polybenzimidazole on at least one surface of the article.
    Type: Grant
    Filed: August 3, 1988
    Date of Patent: October 16, 1990
    Assignee: Hoechst Celanese Corp.
    Inventors: Paul N. Chen, Sr., Paul J. Harget, Thomas J. Dolce
  • Patent number: 4963628
    Abstract: A novel miscible composition comprising from about 5 parts by weight to about 95 parts by weight of a polyarylate and from about 95 parts by weight to about 5 parts by weight of an aromatic polybenzimidazole. In a composition mostly comprised of an aromatic polybenzimidazole, it is preferred that the polyarylate be present in the composition in an amount sufficient to make the aromatic polybenzimidazole more thermally processable and also less susceptible to moisture. More preferably, such compositions are comprised of from about 60 parts by weight to about 95 parts by weight of an aromatic poloybenzimidazole and from about 40 parts by weight to about 5 parts by weight of a polyarylate. Most preferably, such compositions are comprised of at least about 10 parts by weight of a polyacrylate.
    Type: Grant
    Filed: August 26, 1987
    Date of Patent: October 16, 1990
    Assignee: Hoechst Celanese Corp.
    Inventors: Paul N. Chen, Sr., Tai-Shung Chung, Paul J. Harget
  • Patent number: 4963647
    Abstract: The present invention provides novel heat stable polyamide-imide polymers having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one or more aromatic diamines and one or more trifunctional acid anhydride monomers, wherein at least one of said diamine monomers is a 12F-Diamine or 12F-Oxydiamine containing at least two CF.sub.3 ##STR1## R groups linking two aromatic moieties, wherein R is CF.sub.3 or phenyl. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, improved resistance to attack by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as excellent thermal properties including resistance to thermooxidative degredation.
    Type: Grant
    Filed: February 27, 1989
    Date of Patent: October 16, 1990
    Assignee: Hoechst Celanese Corp.
    Inventors: Rohitkumar H. Vora, Paul N. Chen, Sr., Jeffrey S. Devolve
  • Patent number: 4962183
    Abstract: The present invention provides novel heat stable polyamide-imide polymers having excellent flow properties and moisture stability which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one or more aromatic diamines, one or more tetrafunctional aromatic dianhydrides, and a difunctional aromatic carboxylic acid or amide-forming derivative thereof containing the groups ##STR1## linking two aromatic moieties, wherein R is CF.sub.3 or phenyl. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, improved resistance to attack by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as excellent thermal properties, including resistance to thermooxidative degradation.
    Type: Grant
    Filed: May 8, 1989
    Date of Patent: October 9, 1990
    Assignee: Hoechst Celanese Corp.
    Inventors: Paul N. Chen, Sr., Rohitkumar H. Vora
  • Patent number: 4954610
    Abstract: The present invention provides novel heat stable polyamide-imide polymers having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one or more aromatic diamines and one or more trifunctional acid anhydride monomers, at least one of said diamine monomers containing the group ##STR1## linking two aromatic moieties, wherein R is CF.sub.3 or phenyl. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, improved resistance to attack by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as excellent thermal properties including resistance to thermooxidative degradation.
    Type: Grant
    Filed: February 27, 1989
    Date of Patent: September 4, 1990
    Assignee: Hoechst Celanese Corp.
    Inventors: Paul N. Chen, Sr., Rohitkumar H. Vora
  • Patent number: 4954611
    Abstract: The present invention provides for shaped articles made from novel heat stable polyamide-imide polymers having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one or more aromatic diamines, one or more trifunctional acid anhydride monomers, and one or more tetrafunctional aromatic dianhydrides, at least one of said monomers containing the groups ##STR1## linking two aromatic moieties, wherein R is CF.sub.3 or phenyl. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, improved resistance to attach by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as excellent thermal properties including resistance to thermooxidative degradation.
    Type: Grant
    Filed: February 27, 1989
    Date of Patent: September 4, 1990
    Assignee: Hoechst Celanese Corp.
    Inventors: Paul N. Chen, Sr., Rohitkumar H. Vora
  • Patent number: 4923960
    Abstract: The present invention provides novel heat stable polyamide-imide polymers having excellent flow properties which render them more readily processible into fibers, films, sheets and other molded articles. The polymers are prepared by forming the polycondensation product of one of more aromatic diamines, one or more trifunctional acid anhydride monomers, and one or more tetrafunctional aromatic dianhydrides, at least one of said monomers containing the groups ##STR1## linking two aromatic moieties, wherein R is CF.sub.3 or phenyl. In addition to improved flow properties, the polyamide-imide polymers of this invention also exhibit improved solubility properties in most organic solvents, improved resistance to attack by chlorinated solvents such as trichloroethylene as compared with polyimides, improved hydrophobic properties as well as excellent thermal properties including resistance to thermooxidative degradation.
    Type: Grant
    Filed: February 27, 1989
    Date of Patent: May 8, 1990
    Assignee: Hoechst Celanese Corp.
    Inventors: Paul N. Chen, Sr., Rohitkumar H. Vora
  • Patent number: 4842740
    Abstract: This invention discloses novel membranes comprised of a blend of polyarylate and polybenzimidazole polymers. A membrane prepared from the blend of polybenzimidazole and polyarylate polymers exhibits enhanced properties over membranes prepared solely from either a polyarylate or a polybenzimidazole polymer. The addition of the polyarylate to the polybenzimidazole membrane allows the composition to be more thermally processable and less susceptible to moisture. The presence of the polybenzimidazole renders the polyarylate less reactive to solvents and increases its thermal stability. In addition, it has been surprisingly found that membranes prepared from the polybenzimidazole polyarylate blends show high regeneration capacity while retaining good flux ranges. The membranes prepared by this process exhibit good separation characteristics and provide an improved membrane with enhanced qualities over prior art membranes.
    Type: Grant
    Filed: August 5, 1988
    Date of Patent: June 27, 1989
    Assignee: Hoechst Celanese Corporation
    Inventors: Tai-Shung Chung, Paul N. Chen, Sr., Vincent J. Provino