Patents Assigned to Commtech International
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Patent number: 5183549Abstract: An electrolytic sensor is set forth for measuring the amounts of an ionic and of a vaporous species in a liquid. The system has an electrode sensitive to an ionic species and another electrode sensitive to a vaporous species. A unitary membrane covers the electrodes and the requisite electrolyte with the membrane being permeable to the vaporous species, impermeable to the liquid and having dispersed in it an ionophore which senses the ionic species via selective transfer into the membrane of a quantity of the ionic species determined by the concentration of the ionic species in the liquid. Such quantities as hydrogen ion concentration, carbon dioxide concentration and oxygen concentration can be determined by a single electrolytic cell structure.Type: GrantFiled: January 26, 1990Date of Patent: February 2, 1993Assignee: Commtech International Management CorporationInventors: Jose P. Joseph, Marc J. Madou
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Patent number: 5153090Abstract: Novel compounds useful as charge directors in color electrophotographic processes are described. Developer compositions containing the novel charge directors are provided as well. The developer compositions display high particle-mediated conductivity and charge and thus give rise to a final print of exceptionally high quality. Methods of manufacturing the toner and developer compositions are also disclosed, as are processes for using the various compounds and compositions in consecutive multicolor image development.Type: GrantFiled: June 28, 1990Date of Patent: October 6, 1992Assignee: CommTech International Management CorporationInventor: Ronald Swidler
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Patent number: 5069995Abstract: A novel liquid developer composition for use in electrophotographic processes, particularly consecutive color toning, is described. The composition contains, dispersed in a hydrocarbon medium, toner particles of colorant-containing resin and an antistatic agent substantially immiscible with the resin. The antistatic agent effectively eliminates the image staining frequently obtained in consecutive color toning processes. Methods for preparing and using the novel composition are also provided.Type: GrantFiled: May 23, 1989Date of Patent: December 3, 1991Assignee: CommTech International Management CorporationInventor: Ronald Swidler
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Patent number: 5045425Abstract: An electrophotographic liquid developer composition is provided containing a charge director which is a salt of a trivalent metal and an aromatic acid such as diisopropyl salicylic acid. For consecutive color toning processes, it is preferred that the concentration of charge director be maintained below some defined maximum value so that substantially all of the charge director is associated with toner. Methods for making and using the novel compositions are provided as well.Type: GrantFiled: August 25, 1989Date of Patent: September 3, 1991Assignee: CommTech International Management CorporationInventor: Ronald Swidler
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Patent number: 4772678Abstract: Novel liquid crystalline extended chain polymer compositions comprising a high concentration of one or more extended chain homopolymer(s), copolymer(s), or block polymer(s) and certain strong acids are prepared by admixing a high concentration of one or more selected homo- or hetero-bifunctional monomer(s) with or without oxidation protecting atoms or groups and one or more of a substantially non-oxidizing strong acid(s) having a high or low P.sub.2 O.sub.5 content. Such compositions are capable of exhibiting excellent cohesive strength, and are especially suited to the production of high molecular weight ordered polymer fibers by dry-jet wet spinning. These liquid crystalline compositions are capable of being drawn through long air gap distances and spun at exceptionally high spin draw ratios. Fibers, films and other articles formed from these liquid crystalline compositions exhibit exceptionally high physical and heat resistant properties.Type: GrantFiled: August 5, 1985Date of Patent: September 20, 1988Assignee: CommTech International Management CorporationInventors: Joanne R. Sybert, James F. Wolfe, Paul D. Sybert, Blake Wilson
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Patent number: 4703103Abstract: Novel compositions comprising a high concentration of one or more extended chain homopolymer, copolymer, or block polymer and certain polyphosphoric acids are prepared under conditions to exercise control of molecular weight as characterized by intrinsic visoscity. Such compositions are optically anisotropic (liquid crystlaline), capable of exhibiting excellent cohesive strength, and are especially suited to the production of high molecular weight ordered polymer fibers by dry-jet wet spinning. These liquid crystalline compositions are capable of being drawn through long air gap distances and spun at excptionally high spin draw ratios. Fibers, films and other articles formed from these liquid crystalline compositions exhibit exceptionally high physical and heat resistant properties.Type: GrantFiled: March 16, 1984Date of Patent: October 27, 1987Assignee: CommTech InternationalInventors: James F. Wolfe, Paul D. Sybert
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Patent number: 4566133Abstract: An FM diversity receiver system and method are disclosed which include two antennas and a switch for switching the receiver from one antenna to the other. A fade control signal is produced which is related to the received FM signal, in which fade control signal both multipath and non-multipath disturbances are manifested. Disturbances in the fade control signal are compared with a threshold voltage and, when the disturbance exceeds the threshold voltage, antenna switching is momentarily prevented to prevent antenna switching in response to electrical noise impulses, such as ignition noise, which are shorter than the period during which antenna switching is momentarily prevented. If the fade control signal disturbance continues to exceed the threshold voltage after the momentary period of disablement, the threshold voltage is reset to a level related to the maximum level of the fade control signal disturbance, after which antenna switching takes place.Type: GrantFiled: February 13, 1984Date of Patent: January 21, 1986Assignee: Commtech InternationalInventor: William R. Rambo