Patents by Inventor James R. Larson
James R. Larson 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).
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Patent number: 5066821Abstract: A process for preparing an improved positive-working electrostatic liquid developer comprising(A) dispersing at an elevated temperature in a vessel a thermoplastic resin and a nonpolar liquid having a Kauri-butanol value of less than 30, while maintaining the temperature in the vessel at a temperature sufficient to plasticize and liquify the resin and below that at which the nonpolar liquid degrades and the resin decomposes,(B) cooling the dispersion, either(1) without stirring to form a gel or solid mass, followed by shredding the gel or solid mass and grinding by means of particulate media;(2) with stirring to form a viscous mixture and grinding by means of particulate media; or(3) while grinding by means of particulate media to prevent the formation of a gel or solid mass;(C) separating the dispersion of toner particles having an average particle size of less than 30 .mu.Type: GrantFiled: May 11, 1990Date of Patent: November 19, 1991Assignee: DXImagingInventors: William A. Houle, James R. Larson, Kathryn A. Pearlstine
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Patent number: 5034299Abstract: A positive charged electrostatic liquid developer consisting essentially of(A) a non-polar liquid having a Kauri-butanol value of less than 30,(B) thermoplastic resin particles, average by area particle size of less than 10 .mu.m,(C) a charge director compound, and(D) at least one inorganic acid having a solubility of at least 0.5% based on the weight of charge director compound in a mixture of (A) and (C) and represented by the formula:H.sub.x Ywherein x is an integer from 1-4 and is equal to the negative charge on the anion,Y is a moiety selected from the group consisting of Cl.sup.-, F.sup.-, NO.sub.3.sup.-, NO.sub.2.sup.-, PO.sub.4.sup.-3, SO.sub.4.sup.-2, SO.sub.3.sup.-2, ClO.sub.4.sup.-, and IO.sub.4.sup.-.The liquid developer is useful in copying, color proofing, digital color proofing, making lithographic printing plates, and resists.Type: GrantFiled: May 11, 1990Date of Patent: July 23, 1991Assignee: DXImagingInventors: William A. Houle, James R. Larson, Kathryn A. Pearlstine, Torence J. Trout
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Patent number: 5028508Abstract: An electrostatic developer consisting essentially of (A) a nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount; (B) thermoplastic resin particles, less than 30 .mu.m average particle size, a nonpolar liquid soluble ionic or zwitterionic charge director compound (C), and (D) a metal salt of a .beta.-diketone as described. The process of preparation of the liquid electrostatic developer is also described. The liquid developers of the invention are useful in copying, color proofing, including digital color proofing, lithographic printing plates and resists.Type: GrantFiled: December 20, 1989Date of Patent: July 2, 1991Assignee: DXImagingInventors: Gregg A. Lane, James R. Larson, Ronald L. Mueller
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Patent number: 5017451Abstract: A continuous process for the preparation of a dispersion of liquid and resin or polymer particles having at least one additive dispersed in the resin comprisingA. introducing an intimate blend of resin and at least one additive continuously into or blending the ingredients in an apparatus having means for melting the resin and dispersing the additive in the resin,B. melting the resin in the apparatus at an elevated temperature but below that at which the resin and/or additive decomposes,C. moving continuously the blend of melted resin and additive through at least one mixing element of the apparatus dispersing thoroughly the additive in the melted resin (molten blend),D.Type: GrantFiled: November 22, 1989Date of Patent: May 21, 1991Assignee: E. I. Du Pont de Nemours and CompanyInventors: James R. Larson, Kenneth W. Leffew
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Patent number: 4950576Abstract: An electrostatic liquid developer consisting essentially of (A) a nonpolar liquid having a Kauributanol value of less than 30, present in major amount; (B) thermoplastic resin particles less than 30 .mu.m average particle size; (C) a chromium, molybdenum or tungsten compound having an oxidation state of at least +3 wherein the anionic component is as defined above, and (D) a nonpolar liquid soluble ionic or zwitterionic charge director compound. The process of preparation of the electrostatic liquid developer is also described. The liquid developers are useful in copying, color proofing including digital color proofing, lithographic printing plates, and resists.Type: GrantFiled: May 10, 1989Date of Patent: August 21, 1990Assignee: E. I. DuPont De Nemours and CompanyInventor: James R. Larson
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Patent number: 4937158Abstract: An electrostatic liquid developer consisting essentially of (A) a nonpolar liquid having a Kauri-butanol value of less than 30, present in major amount; (B) thermoplastic resin particles, less than 30 .mu.m average particle size, having dispersed therein a nickel (II) salt; and a nonpolar liquid soluble ionic or zwitterionic charge director compound. The process of preparation of the electrostatic liquid developer is also described. The liquid developers of the invention are useful in copying, color proofing including digital color proofing, lithographic printing plates, and resists.Type: GrantFiled: May 10, 1989Date of Patent: June 26, 1990Assignee: E. I. du Pont de Nemours and CompanyInventor: James R. Larson
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Patent number: 4935328Abstract: Electrostatic liquid developer having improved negative charging characteristics consisting essentially of(A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount,(B) thermoplastic resin particles having an average by area particle size of less than 10 .mu.m,(C) charge director compound, and(D) at least one soluble solid or liquid organic monofunctional amine compound of the formula: R.sub.n NH.sub.3-n wherein R is alkyl, cycloalkyl or alkylene, or substituted alkyl, the alkyl, cycloalkyl, alkylene or substituted alkyl group being of 1 to 50 carbon atoms, and n is an integer of 1 to 3.Optionally, a colorant, e.g., a pigment; metallic soap, adjuvant can be present. The electrostatic liquid developer is useful in copying, making proofs including digital color proofs, lithographic printing plates, and resists.Type: GrantFiled: April 7, 1988Date of Patent: June 19, 1990Assignee: E. I. du Pont de Nemours and CompanyInventors: Lyla M. El-Sayed, James R. Larson, Torence J. Trout
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Patent number: 4923778Abstract: Process for preparation of toner particles for electrostatic liquid developers utilizing a single vessel wherein (A) a thermoplastic resin and hydrocarbon liquid having a Kauri-butanol value of less than 120 at a total of solids of at least 22% by weight are dispersed in the vessel by moving particulate media (crating shear) at elevated temperature to plasticize and liquify the resin, (B) while the particulate media are maintained in continuous motion the dispersion is cooled whereby the resin precipitates in the form of toner particle having an average by area particle size of 10 .mu.m or less, and (C) the particulate media are removed. Liquid electrostatic developers are prepared by the addition of a charge director compound. The liquid developers are prepared in a shorter time that previously known processes. The liquid developers are useful for preparation of copies and proofs of various colors.Type: GrantFiled: December 23, 1988Date of Patent: May 8, 1990Assignee: D X ImagingInventors: David E. Blair, Bradley J. Gollhardt, James R. Larson
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Patent number: 4783389Abstract: Process for the preparation of toner particles for liquid electrostatic imaging comprising(A) mixing a thermoplastic resin and a nonpolar liquid at a temperature sufficient to plasticize and liquify the resin and below that at which the nonpolar liquid boils and the resin decomposes,(B) cooling the mixture to form resin particles in the nonpolar liquid,(C) reducing the size of the resin particles to below about 30 .mu.m by passing the product of step (B) through at least one liquid jet interaction chamber at a liquid pressure of at least 1000 p.s.i., e.g., a Microfluidizer.RTM..The process produces liquid electrostatic developer quicker than other known processes, the developer being useful in copying, making proofs, including digital proofs, etc.Type: GrantFiled: March 27, 1987Date of Patent: November 8, 1988Assignee: E. I. Du Pont de Nemours and CompanyInventors: Torence J. Trout, James R. Larson
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Patent number: 4783388Abstract: Negative-working electrostatic liquid developer having improved charging characteristics consisting essentially of(A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount,(B) thermoplastic resin particles having an average by area particle size of less than 10 .mu.m,(C) nonpolar liquid soluble ionic or zwitterionic compound, and(D) a quaternaryammonium hydroxide compound as defined, e.g., tetraethylammonium hydroxide, tetrabutylammonium hydroxide, etc., soluble in an amount of at least 0.5 part per million by weight in the nonpolar liquid.The electrostatic liquid developer is useful in copying, making proofs including digital color proofs, lithographic printing plates, and resists.Type: GrantFiled: June 17, 1987Date of Patent: November 8, 1988Assignee: E. I. Du Pont de Nemours and CompanyInventors: Lyla M. El-Sayed, James R. Larson
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Patent number: 4780388Abstract: Electrostatic liquid developer having improved charging characteristics consisting essentially of(A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount,(B) thermoplastic resin particles having an average by area particle size of less than 10 .mu.m,(C) nonpolar liquid soluble ionic compound, and(D) at least one organic polyamine compound having at least 2 amino groups present on adjacent carbon atoms.Optionally, a colorant, e.g., a pigment; metallic soap can be present. The electrostatic liquid developer is useful in copying, making proofs including digital color proofs, lithographic printing plates, and resists.Type: GrantFiled: May 26, 1987Date of Patent: October 25, 1988Assignee: E. I. Du Pont de Nemours and CompanyInventor: James R. Larson
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Patent number: 4772528Abstract: A liquid electrostatic developer containing negatively chargeable resin particles with improved charging characteristics, said developer consisting essentially of(A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount;(B) resin particles of a blend of at least two polymers, at least one polymer containing at least one acidic constituent having a pKa of less than 4.5 measured at 25.degree. C. in water, and the blend having an acid number of at least one due to said acidic constitutent; the resin particles having an average by area particle size of less than 10 .mu.m, and(C) nonpolar liquid soluble ionic or zwitterionic charge director compound.A preferred polymer blend is composed of polystyrene and a sulfonated polymer, e.g., poly(2-acrylamido-2-methyl-1-propanesulfonic acid). The average resin particle size by area is less than 10 .mu.m. Optionally a colorant and other additives or adjuvants are present.Type: GrantFiled: May 6, 1987Date of Patent: September 20, 1988Assignee: E. I. Du Pont de Nemours and CompanyInventors: James R. Larson, Torence J. Trout
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Patent number: 4760009Abstract: Process for preparation of toner particles for electrostatic imaging comprising (A) dispersing in a vessel at elevated temperature thermoplastic resin, nonpolar liquid and optionally a colorant, e.g., pigment, using moving particulate media, the temperature being sufficient to plasticize and liquify the resin and below the decomposition temperature of resin and/or colorant and below nonpolar liquid boiling point; (B) cooling the dispersion while maintaining continuous movement of the particulate media during and subsequent to cooling whereby toner particles are formed having an average by area particle size of less than 10 .mu.m and a plurality of fibers; and (C) separating the dispersion having a concentration of toner particles from the particulate media. After step (C) the dispersion can be diluted with additional nonpolar solvent and/or a charge director can be added. The dispersion having a concentration of toner particles is useful for the preparation of copies and proofs of various colors.Type: GrantFiled: December 4, 1985Date of Patent: July 26, 1988Assignee: E. I. Du Pont de Nemours and CompanyInventor: James R. Larson
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Patent number: 4736522Abstract: Process for loading of test pins into printed circuit board test fixtures. Test pins are loaded into a loader body, and locked thereto by a sliding locking plate through frictional engagement at an interface where in test pin hole is of a reduced surface area. Upon alignment of the loading body to the sliding lock plate, increasing surface area of each test pin hole, the test pins drop through the loading body into the test fixture. The lower surface area of the head of the test pin controls movement of the test pin between the loading body and the test fixture through gravity free fall. After circuit board testings, the test pins are reloaded back to the original location within the loader body for subsequent new circuit loading and testing.Type: GrantFiled: January 5, 1987Date of Patent: April 12, 1988Assignee: Holaday Circuits, Inc.Inventor: James R. Larson
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Patent number: 4709207Abstract: Loading system for loading of test pins into printed circuit board test fixtures. Test pins are loaded into a loader body, and locked thereto by a sliding locking plate through frictional engagement at an interface where in test pin hole is of a reduced surface area. Upon alignment of the loading body to the sliding lock plate, increasing surface area of each test pin hole, the test pins drop through the loading body into the test fixture. The lower surface area of the head of the test pin controls movement of the test pin between the loading body and the test fixture through gravity free fall. After circuit board testings, the test pins are reloaded back to the original location within the loader body for subsequent new circuit loading and testing.Type: GrantFiled: August 8, 1985Date of Patent: November 24, 1987Assignee: Holaday Circuits, Inc.Inventor: James R. Larson
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Patent number: 4702985Abstract: Electrostatic liquid developer having improved charging characteristics comprising(A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount,(B) thermoplastic resin particles having an average by area particle size of less than 10 .mu.m,(C) nonpolar liquid soluble ionic or zwitterionic compound, and(D) at least one aminoalcohol compound.The electrostatic liquid developer is useful in copying, making proofs including digital color proofs, lithographic printing plates, and resists.Type: GrantFiled: April 28, 1986Date of Patent: October 27, 1987Assignee: E. I. Du Pont de Nemours and CompanyInventor: James R. Larson
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Patent number: 4681831Abstract: A liquid electrostatic developer containing negatively chargeable resin particles with improved charging characteristics, said developer consisting essentially of(A) nonpolar liquid having a Kauri-butanol value of less than 30, present in a major amount,(B) nonpolar liquid soluble ionic or zwitterionic charge director compound, and(C) resin particles of a polymer containing at least one acidic constituent having a pKa less than 4.5, preferably 3.0, at 25.degree. C. in water and an acid number due to said acidic constituent of at least one. The average resin particle size by area is less than 10 .mu.m. Optionally a colorant and other additives or adjuvants are present. The liquid electrostatic developer is useful in copying making proofs including digital color proofs, lithographic printing plates, and resists.Type: GrantFiled: June 30, 1986Date of Patent: July 21, 1987Assignee: E. I. Du Pont de Nemours and CompanyInventors: James R. Larson, Torence J. Trout