Atom Other Than C, O, H, P, Or Hal Patents (Class 524/148)
  • Patent number: 5378740
    Abstract: A waterborne structural adhesive bonding primer composition (a) that can be effectively applied to an adherend for structural adhesive applications, (b) that emits a VOC content of less than about 250 grams per liter, (c) is thermally stable, and (d) may be employed with 350.degree. F. (176.7.degree. C.) cure epoxy resin systems, which contains the combination of (i) a dialkanol amine adduct of an oxazolidinone modified polyglycidyl ether of a tris(hydroxyphenyl)alkane dissolved in a water vehicle, and (ii) a rigid ring substituted polyethylenically unsaturated carboxylate, carboxamide or carboximide intimately dispersed in the water vehicle and the dialkanol amine adduct of an oxazolidinone modified polyglycidyl ether of a tris(hydroxyphenyl)alkane. Formulations are described that contain chromate-free corrosion inhibitors.
    Type: Grant
    Filed: April 30, 1992
    Date of Patent: January 3, 1995
    Assignee: The Dexter Corporation
    Inventor: Yiuto D. Ng
  • Patent number: 5357030
    Abstract: The invention relates to a process for producing chain extended polyamide compositions which comprise one or more polyamides and one or more lactamyl phosphites.
    Type: Grant
    Filed: June 3, 1992
    Date of Patent: October 18, 1994
    Assignee: AlliedSignal Inc.
    Inventors: Bruce VanBuskirk, Murali K. Akkapeddi, Jeffrey H. Glans
  • Patent number: 5322871
    Abstract: Compounds of the formula I ##STR1## in which x is 1, 2 or 3, and, if x=1, R.sup.1 is C.sub.1 -C.sub.30 alkyl, C.sub.1 -C.sub.18 alkyl substituted by halogen, --COOR.sup.2, --CN, --NR.sup.3 R.sup.4 or by --CONR.sup.3 R.sup.4, C.sub.2 -C.sub.18 alkyl which is interrupted by --NR.sup.5 --, --O-- or --S--, C.sub.3 -C.sub.18 alkenyl, C.sub.5 -C.sub.12 cycloalkyl, phenyl-C.sub.1 -C.sub.4 alkyl, phenyl which is unsubstituted or substituted by C.sub.1 -C.sub.12 alkyl, halogen, phenyl-C.sub.1 -C.sub.4 alkyl and/or C.sub.1 -C.sub.4 alkoxy, or R.sub.1 is naphthyl, a radical of the formula ##STR2## R.sub.2, R.sub.3, R.sub.4 and R.sub.5, independently of one another, are hydrogen, C.sub.1 -C.sub.18 alkyl, C.sub.5 -C.sub.12 cycloalkyl or phenyl-C.sub.1 -C.sub.4 alkyl, R.sup.6 is hydrogen, methyl, allyl or benzyl, R.sup.7 is hydrogen or --OR.sup.9, R.sup.8 is hydrogen or methyl, R.sup.9 is hydrogen or C.sub.1 -C.sub.30 alkyl, R.sup.10 and R.sup.11, independently of one another, are hydrogen or C.sub.1 -C.sub.
    Type: Grant
    Filed: April 20, 1993
    Date of Patent: June 21, 1994
    Assignee: Ciba-Geigy Corporation
    Inventors: Rita Pitteloud, Peter Hofmann, Rudolf Maul, Volker Schenk, Eduard Troxler, Horst Zinke
  • Patent number: 5281640
    Abstract: Diarylphosphinous acid aryl esters are made by the disclosed process. These compounds are useful for stabilizing plastics, in particular polymerization plastics, and hence can be incorporated into a plastic molding composition.
    Type: Grant
    Filed: July 24, 1992
    Date of Patent: January 25, 1994
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Dieter Regnat, Manfred Bohshar, Hans-Jerg Kleiner, Gerhard Pfahler
  • Patent number: 5256718
    Abstract: The present invention provides resin compositions containing thermoplastic resins. Thermoplastic resins employable for the compositions are polyolefin resins, polyester resins, polystyrene resins, polyamide resins and polyphenylene ether resins. The present invention can be particularly effected by using polyamide, particularly, specific aromatic polyamides.In the present invention, the resin compositions can be improved in various chemical and physical properties such as flame-retardance, moldability, color tone, heat stability, mechanical strength by the use of other resin component and stabilizers such as halogenated organic compounds, modified polyolefins, antimony compounds, phosphorus-containing compounds, amine- or phosphorus-type stabilizers.
    Type: Grant
    Filed: February 12, 1991
    Date of Patent: October 26, 1993
    Assignee: Mitsui Petrochemical Industries, Ltd.
    Inventors: Sanehiro Yamamoto, Hideki Sakai, Hirotaka Aso, Kazuo Ishiwatari, Fumitoshi Ikejiri
  • Patent number: 5151455
    Abstract: A flame retardant having excellent resistance to water and acid for a long period of time and comprising 100 parts by weight of magnesium hydroxide of which the surface is treated with a phosphoric ester of formula (I) ##STR1## wherein R represents an alkyl or alkenyl group having 10 to 30 carbon atoms, M represents an atom belonging to group IA of the periodic table or NH.sup.4+, and n represents 1 or 2, and 0.1 to 10 parts by weight of a salt of a metal other than alkali metals with a higher fatty acid, and a resin composition containing the flame retardant.
    Type: Grant
    Filed: July 10, 1990
    Date of Patent: September 29, 1992
    Assignee: Kyowa Chemical Industry
    Inventors: Shigeo Miyata, Makoto Yoshii
  • Patent number: 5145894
    Abstract: A stabilized polyaryl ether ketone molding composition contains as essential componentsA: from 50 to 99.99% by weight of a polyaryl ether ketone A prepared by electrophilic polycondensation and at least 50 mol % of which is made up of units of the general formula I ##STR1## where s and t are each 0, 1,2, or 3 and T and T' are each --O-- or --CO--, or a ring-substituted C.sub.1 -C.sub.8 -alkyl, c.sub.6 -C.sub.20 -arly or halogen derivative thereof,B: from 0.01 to 4% by weight of a phosphorus compound B containing units of the general formula IIa ##STR2## or of the general formula IIb ##STR3## in which the substituents and indices have the following meanings: V is oxygen or sulfur,Q.sup.1 is C.sub.1 -C.sub.25 -alkyl or aryl or from 6 to 25 carbon atoms in which the aromatic rings can be monosubstituted, disubstituted or trisubstituted by slkyl of from 1 to 4 carbon atoms,Q.sup.2 and Q.sup.3 are each independently of the other C.sub.1 -C.sub.20 -alkyl, C.sub.1 -C.sub.
    Type: Grant
    Filed: July 10, 1991
    Date of Patent: September 8, 1992
    Inventors: Juergen Koch, Gregor Schuermann, Gerhard Heinz
  • Patent number: 5116919
    Abstract: A process for increasing the relative viscosity of a polyamide includes heating the polyamide in the presence of a base and a catalyst with the catalyst being at least one compound of the formula:X--(CH.sub.2).sub.n PO.sub.3 R.sub.2wherein X is 2-pyridyl, 4-morpholino, 1-pyrrolidino, 1-piperidino or R'.sub.2 --N-- wherein R' is an alkyl group having between 1 and 12 carbon atoms;n is an integer from 2 to 5; andR, being the same or different, is H or an alkyl group having between 1 and 12 carbon atoms.
    Type: Grant
    Filed: December 5, 1990
    Date of Patent: May 26, 1992
    Assignee: E. I. du Pont de Nemours and Company
    Inventors: John F. Buzinkai, Marion R. DeWitt, Jr., Robert C. Wheland
  • Patent number: 5096951
    Abstract: A polyoxymethylene molding composition which exhibits improved ambient and heat aged color stability includes a metal deactivator and calcium hydroxystearate. One preferred composition of the invention includes: (a) greater than about 95 weight percent of polyoxymethylene, (b) between about 0.01 to about 0.1 weight percent of 3 salicyloyl-amido-1,2,4 triazole or tris-2-tert.butyl- 4-thio-(2'methyl-4'hydroxy-5'tert.butyl) phenyl-5-methyl phenyl phosphite, (c) between about 0.015 to about 0.4 weight percent of 2,4,6-triamino-sym-triazine, (d) between about 0.25 to about 1.0 weight percent of tetrakis(methylene-(3,5-di-tert-butyl- 4-hydroxyhydrocinnamate)) methane, (e) between about 0.05 to about 0.2 weight percent of calcium 12-hydroxystearate, and (f) between about 0.1 to about 0.3 weight percent of N-N'-ethylenebisstearamide. Due to their enhanced color stability, the compositions of this invention find particular utility as molded automobile components.
    Type: Grant
    Filed: December 13, 1990
    Date of Patent: March 17, 1992
    Assignee: Hoechst Celanese Corporation
    Inventor: Andrew Auerbach
  • Patent number: 5045579
    Abstract: The preparation and use of unique, environmentally benign, economical and selectively modified polynorbornene sponges are described as selective absorbents for hydrocarbons, their halogenated analogs and selected oxygenated derivatives thereof. The modified polynorbornene material contains organo-titanium phosphates or oligophosphates and is environmentally stable for extended periods, easy to use, efficient and absorbate-retentive. Exhausted product will not drip or exude absorbate under conventional landfill disposal conditions and will produce only minimal ash when incinerated.
    Type: Grant
    Filed: May 18, 1990
    Date of Patent: September 3, 1991
    Assignee: Liquid Waste Corporation
    Inventor: Gerald Sugerman
  • Patent number: 4983656
    Abstract: An aqueous pressure-sensitive adhesive consisting essentially of (1) 100 parts by weight (in terms of solids content) of an aqueous copolymer emulsion obtained by emulsion-polymerizing a monomer mixture consisting of 70-99.9% by weight of at least one alkyl (meth)acrylate in which the alkyl group has 4-12 carbon atoms, 0.1-10% by weight of an .alpha.,.beta.-unsaturated carboxylic acid and 0-29.9% by weight of a monomer copolymerizable therewith, (2) 0.1-10 parts by weight of a phosphoric acid ester compound, and (3) a polyglycidyl compound in such an amount that the proportion of the epoxy group in the polyglycidly compound is 0.1-3 equivalents per equivalent of the carboxyl group in the aqueous copolymer. This aqueous pressure-sensitive adhesive has excellent balance in adhesion to adherend, peelability from adherend and anchoring to substrate; and the peelability from adherend is not varied depending upon the type of adherend and does not change with time or by heating.
    Type: Grant
    Filed: March 10, 1989
    Date of Patent: January 8, 1991
    Assignee: Japan Synthetic Rubber Co., Ltd.
    Inventors: Toshiyuki Ito, Yorinobu Ikeda, Yasuhisa Watanabe, Hiroshi Tadenuma
  • Patent number: 4957954
    Abstract: Polyvinyl chloride resin stabilizer compositions are provided, comprising a 2,2,6,6-tetramethyl piperidinyl compound and an ammonium or metal perchlorate; and also stabilized polyvinyl chloride resin compositions containing such stabilizers, and optionally including a plasticizer, and particularly as molded articles with polyurethane foam backing.
    Type: Grant
    Filed: January 25, 1989
    Date of Patent: September 18, 1990
    Assignee: Adeka Argus Chemical Co., Ltd.
    Inventors: Shunichi Iizuka, Yoshiyuki Sakamaki, Noriyuki Shimoyama
  • Patent number: 4946909
    Abstract: A process for forming random copolymers which comprises forming a polymer melt containing one or more polyamides and one or more aryl phosphoryl azide compounds, such as diphenyl phosphoryl azide; and heating said melt for a period of time sufficient to form the desired amount of the copolymer.
    Type: Grant
    Filed: November 3, 1988
    Date of Patent: August 7, 1990
    Assignee: Allied-Signal Inc.
    Inventors: Himangshu R. Bhattacharjee, Yash P. Khanna
  • Patent number: 4900785
    Abstract: The invention relates to thermoplastic molding compounds containing1. thermoplastic aromatic polycarbonates and/or thermoplastic aromatic polyesters,2. graft polymers,3. special copolymers corresponding to formula (Ia)[A-X-B].sub.r (Ia)and, optionally,2a. thermoplastic copolymers, stabilizers, pigments, mold release agents, flameproofing agents and/or antistatic agents.The invention also relates to a process for the production of the molding compounds.
    Type: Grant
    Filed: March 6, 1989
    Date of Patent: February 13, 1990
    Assignee: Bayer Aktiengesellschaft
    Inventors: Edgar Leitz, Herbert Eichenauer, Karl-Heinz Ott, Horst Peters, Jochen Schoeps
  • Patent number: 4871793
    Abstract: Polyphenylene sulfide resin compositions are provided having improved light stability and comprising an alkylidene bis(benzotriazolyl phenol) having the formula: ##STR1## wherein: R.sub.1 is selected from the group consisting of hydrogen and alkyl having from one to about eleven carbon atoms;R.sub.2 is selected from the group consisting of alkyl having from one to about twelve carbon atoms; and arylalkyl having from seven to about eighteen carbon atoms; andX is selected from the group consisting of hydrogen; halogen; alkyl having from one to about twelve carbon atoms; aryl alkyl having from seven to about eighteen carbon atoms; alkoxy having from one to about twelve carbon atoms; phenoxy; arylalkoxy having from seven to about eighteen carbon atoms; and phenyl.
    Type: Grant
    Filed: January 21, 1987
    Date of Patent: October 3, 1989
    Inventors: Yutaka Nakahara, Atsushi Nishimura, Toshio Nakajima
  • Patent number: 4812499
    Abstract: Compositions of thermoplastic polymers comprising, in mixture, a thermoplastic polymer and a mixture of self-extinguishability-conferring additives, formed by:ammonium phosphate or ammonium polyphosphate: ##STR1## (wherein p is preferably equal to or greater than 50); phosphorus-containing compound definable by means of the general formula: ##STR2## (wherein R.sub.1, R.sub.2 and R.sub.3 have the meaning as indicated in the disclosure).
    Type: Grant
    Filed: March 20, 1986
    Date of Patent: March 14, 1989
    Assignee: Enichem Sintesi S.p.A.
    Inventors: Gioacchino Cipriani, Gianluigi Landoni
  • Patent number: 4812500
    Abstract: An improved polyolefin pipe or wire and coating composition having improved resistance to deterioration in the presence of chlorinated and nonchlorinated water and having improved resistance to temperatures in the range of about 0.degree. C., as well as in cool water consisting of a blend of:(a) about 93 to about 99.5 percent by weight of an isotactic poly-1-butene polymer;(b) about 0.05 to about 0.50 percent by weight of a hindered amine UV stabilizer;(c) about 0.05 to about 1.1 by weight of a hindered phenolic thermal stabilizer having a molecular weight above 530;(d) about zero to about 0.5 percent by weight of a nucleating agent;(e) about zero to about 4 percent by weight of a pigment;(f) about zero to about 3.0 percent by weight of a filler; and(g) up to about 3.0 percent by weight of a chelating agent.
    Type: Grant
    Filed: September 30, 1987
    Date of Patent: March 14, 1989
    Assignee: Shell Oil Company
    Inventor: Earl E. Hayden
  • Patent number: 4812498
    Abstract: Polycarbonate resin compositions are provided having improved light stability and comprising an alkylidene bis(benzotriazolyl phenol)having the formula: ##STR1## wherein: R.sub.1 is selected from the group consisting of hydrogen and alkyl having from one to about eleven carbon atoms;R.sub.2 is selected from the group consisting of alkyl having from one to about twelve carbon atoms; and arylalkyl having from seven to about eighteen carbon atoms; andX is selected from the group consisting of hydrogen; halogen; alkyl having from one to about twelve carbon atoms; aryl alkyl having from seven to about eighteen carbon atoms; alkoxy having from one to about twelve carbon atoms; phenoxy; arylalkoxy having from seven to about eighteen carbon atoms; and phenyl.
    Type: Grant
    Filed: December 22, 1986
    Date of Patent: March 14, 1989
    Assignee: Adeka Argus Chemical Co., Ltd.
    Inventors: Yutaka Nakahara, Atsushi Nishimura, Toshio Nakajima
  • Patent number: 4798836
    Abstract: Bis-(2,2,6,6-tetramethyl-piperidyl)diimides are provided, having the formula: ##STR1## in which R is selected from the group consisting of hydrogen; oxyl; alkyl and alkenyl having from one to about eighteen carbon atoms; epoxy and hydroxyalkyl having from two to about eight carbon atoms; acyl having from two to about eight carbon atoms; and phenalkyl having from seven to about twelve carbon atoms; and Z is a tetravalent aliphatic or cycloaliphatic hydrocarbon group having from two to about eighteen carbon atoms; and stabilizer and synthetic polymer compositions containing such diimides having improved resistance to deterioration when exposed to light.
    Type: Grant
    Filed: October 26, 1987
    Date of Patent: January 17, 1989
    Assignee: Adeka Argus Chemical Co., Ltd.
    Inventors: Motonobu Minagawa, Yutaka Nakahara, Bunji Hirai, Kazuo Sugibuchi
  • Patent number: 4792579
    Abstract: There is disclosed a stabilized oxymethylene copolymer composition comprising a blend of an oxymethylene copolymer and an alkaline earth metal salt of an ester of a tribasic inorganic acid of an organic carboxylic acid monoester of an alcohol having two or more hydroxyl groups, as the stabilizer.
    Type: Grant
    Filed: February 19, 1988
    Date of Patent: December 20, 1988
    Assignee: Asahi Kasei Kogyo Kabushiki Kaisha
    Inventors: Seinosuke Satoh, Minoru Hamada
  • Patent number: 4776981
    Abstract: The present invention relates to phthalimide compounds of the formula (I) ##STR1## wherein X denotes H or halogen, for example chlorine or bromine,a and b independently of one another denote 0 or 1 andR denotes a C.sub.1 -C.sub.4 -alkyl radical,which, in combination with alkali metal salts, are suitable as flameproofing agent combinations for thermoplastic, branched, aromatic polycarbonates, and the preparation of these compounds.
    Type: Grant
    Filed: August 24, 1987
    Date of Patent: October 11, 1988
    Assignee: Bayer Aktiengesellschaft
    Inventors: Hans-Jurgen Kress, Klaus Kircher
  • Patent number: 4745144
    Abstract: The silicone rubber composition comprises, in addition to the conventional ingredients of a high-polymeric diorganopolysiloxane and a reinforcing silica filler, a specific phosphorus-containing organic compound, such as phosphinates, phosphonates and phosphates, in a limited amount. By virtue of this unique ingredient, the composition can give a cured silicone rubber product having greatly improved resistance against dynamic fatigue.
    Type: Grant
    Filed: August 14, 1986
    Date of Patent: May 17, 1988
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Kunio Itoh, Kiyoshi Imai, Takeshi Fukuda, Nobuyuki Uesugi
  • Patent number: 4742099
    Abstract: A new polyimide film which contains 30 to 800 ppm of titanium based on the weight of the film, and a process for producing a new polyimide film which comprises introducing an organic titanium compound substance into the film-forming polyimide resin prior to the casting step. This process enables one to control the film surface forming process and improve directly the adhesive properties of the film.
    Type: Grant
    Filed: December 1, 1986
    Date of Patent: May 3, 1988
    Assignee: Kanegafuchi Kagaku Kogyo Kabushiki Kaisha
    Inventors: Hirosaku Nagano, Junji Takase, Hideki Kawai, Hitoshi Nojiri, Tsuneo Yamamoto
  • Patent number: 4704418
    Abstract: A fire-resistant thermoplastic composition comprising polyvinyl butyral resin and a compatible mixture in an amount sufficient to provide fire-resistant properties to such composition which includes (a) a plasticizer blend of a char-forming component, such as an organic phosphate, and an oxygen sequestering agent, such as an organic phosphite, wherein the char-forming component is the major constituent; (b) a nucleating agent such as fumed silica for dispersing the fire decomposition products of the composition; and (c) a heat reactive bonding resin.
    Type: Grant
    Filed: December 23, 1985
    Date of Patent: November 3, 1987
    Assignee: Monsanto Company
    Inventor: I. Luis Gomez
  • Patent number: 4661543
    Abstract: The present invention relates to phthalimide compounds of the formula (I) ##STR1## wherein X denotes H or halogen, for example chlorine or bromine,a and b independently of one another denote 0 or 1 andR denotes a C.sub.1 -C.sub.4 -alkyl radical,which, in combination with alkali metal salts, are suitable as flameproofing agent combinations for thermoplastic, branched, aromatic polycarbonates, and the preparation of these compounds.
    Type: Grant
    Filed: October 17, 1984
    Date of Patent: April 28, 1987
    Assignee: Bayer Aktiengesellschaft
    Inventors: Hans-Jurgen Kress, Klaus Kircher
  • Patent number: 4569962
    Abstract: Polymeric compositions are provided in which perfluoropolyethers have been solubilized in non-fluorinated solvents by combining them with a solubilizing agent such as azotic conjugated compounds, and phosphorylated compounds. Typical of the perfluoropolyethers is ##STR1## Typical of the solubilizing agents is phosphorylated methacryloyloxyhydroxypropylisophthalate. The perfluoropolyether and the solubilizing agent are mixed to form a paste which is soluble in organic solvents such as methylethylketone. These compositions find utility as protective lubricant coatings for thin film magnetic recording media. They have the advantage that only one coating step is required in order to apply both the phosphorylated compound and the lubricating polyether. Recording media lubricated with these compositions have demonstrated excellent wear characteristics.
    Type: Grant
    Filed: September 19, 1983
    Date of Patent: February 11, 1986
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Mario D. Burguette, George D. Foss
  • Patent number: 4488985
    Abstract: Novel phosphoramidates of the general formula: ##STR1## wherein R, R' and R" represent certain specified substituent groups, are useful as stabilizing agents for organic materials, such as natural and synthetic rubbers and lubricating oils. The combined use of these compounds with certain sulfur-containing compounds shows a surprising synergistic effect.
    Type: Grant
    Filed: July 21, 1983
    Date of Patent: December 18, 1984
    Assignee: Akzona Incorporated
    Inventors: Paul K. Battey, Peter Hope
  • Patent number: 4404339
    Abstract: This invention relates to the suspension polymerization of vinyl halides and vinylidene halides in an aqueous medium to make polymers and copolymers which are designed for use in making plastisols. The process is conducted in an aqueous medium using a free-radical yielding catalyst, and in the presence of a hydrolyzed polyvinyl acetate (polyvinyl alcohol) having a degree of hydrolysis in the range of about 65% to about 85% and a compound having a hydrophile-lipophile balance (HLB) less than about 3.5. The important aspect of the present new process is the use of agitation ramping, that is, changing the degree of agitation during the course of the reaction, and adding the catalyst to the reaction medium after the same has reached the reaction temperature whereby these are produced polymer particles which are dense spherical glassy beads having an average diameter in the range of about 10 to about 100 microns.
    Type: Grant
    Filed: October 15, 1979
    Date of Patent: September 13, 1983
    Assignee: The B. F. Goodrich Company
    Inventors: Charles N. Bush, Thomas J. Doyle
  • Patent number: 4377652
    Abstract: An article for electrical use such as insulative substrates, electrical circuit borads and electrical elements, wholly or partly consisting out of an aromatic polyamide-imide having a reduced viscosity of from about 0.3 to 1.5, which polyamide-imide may contain a granular material dispersed therein, and a composition comprising 100 parts by weight of said polyamide-imide and additional about 100 to 4,000 parts by weight of a granular material and optionally about 10 to 10,000 parts by weight of a polar organic solvent.
    Type: Grant
    Filed: February 8, 1979
    Date of Patent: March 22, 1983
    Assignee: Asahi Kasei Kogyo Kabushiki Kaisha
    Inventors: Kaoru Ohmura, Ichiro Shibasaki, Takeo Kimura
  • Patent number: 4363887
    Abstract: There is disclosed a water-in-oil emulsion enamel composition having water dispersed in an organic solvent soluble resin and solvent, and having the polar enamel pigment dispersed through the use of titanium derived coupling agents. Amine salts of pyrophosphato titanium derived coupling agents act as pigment dispersants and as the water-in-oil emulsifying agent. The composition may be mixed with a hydrocarbon propellant miscible in the continuous phase in suitable containers to produce a water containing aerosol spray enamel.
    Type: Grant
    Filed: June 11, 1981
    Date of Patent: December 14, 1982
    Assignee: Seymour of Sycamore, Inc.
    Inventor: Gus W. Leep
  • Patent number: 4356280
    Abstract: A dispersion is provided for incorporation with a synthetic fiber-forming polymer. The dispersion comprises a polymer additive, such as titanium dioxide, and a glyceride which is non-resin forming when exposed to certain temperatures and pressures for specified time periods and which has an average molecular weight of between about 600 and 2400.
    Type: Grant
    Filed: April 15, 1981
    Date of Patent: October 26, 1982
    Assignee: Allied Corporation
    Inventors: Rodney L. Wells, Monty L. Rowe, Samuel L. Yates, George R. Muller