Abstract: A novel, fatigue resistant fitting of the joint ring type used between bolted, flanged sections of high pressure tubing is provided which safely and durably serves the dual functions of high pressure joint sealing and convenient instrumentation tap access. The fitting comprises two concentric, thick-walled cylindrical shells with the outer shell shrink-fitted onto the inner shell which is free of threaded portions or other stress concentration points except for one or two radial bores at about its midlength, and in axial alignment with each of said radial bores, a cleanly threaded aperture of substantially larger diameter through said outer shell. For maximum fatigue resistance under difficult service, the compound shell fitting is also subjected to an autofrettage treatment.
Abstract: A crystallization apparatus and process especially useful for the continuous regeneration of metal processing solutions, such as copper etchants, where direct recovery of metal values in the form of large crystals of high solids content is achieved and fouling of heat exchange surfaces is obviated by a scouring action obtained through addition of preformed crystals to the heat exchange zone.
Abstract: This invention relates to the use of indium compounds as thermal stabilizers for vinyl halide resins. Very small additions of indium compounds to vinyl halide resins, with or without the inclusion of other stabilizers, have been found to contribute marked improvements in resistance to high temperature discoloration. For example, additions sufficient to provide less than 100 ppm of indium based upon the weight of said resin are particularly effective in helping to maintain original color over a longer period of time at elevated temperatures such as are encountered during hot processing and fabricating operations.
Abstract: Clean etchings at high rates are obtained using a solution containing sulfuric acid, hydrogen peroxide, a catalytic amount of a selenium compound of a +4 oxidation state and a secondary or tertiary alcohol.
Abstract: Improved metal dissolution rates are obtained when using a solution containing sulfuric acid, hydrogen peroxide and an effective amount of a ketone soluble in the solution.
Abstract: Liquid antimony organic sulfur-containing compounds are rendered stable at ambient conditions by incorporating an effective amount of a phenol. Liquid antimony organic sulfur-containing compounds such as antimony mercaptoacid esters, and the like, are also rendered shelf stable by phenols such as catechol, t-butyl catechol and butylated hydroxy anisole. The stable liquid compositions contribute to the heat stability of vinyl halide resins.
Abstract: Process for the telomerization of olefins with secondary alcohols comprising admixing a secondary alcohol telogen with a mono-olefinically unsaturated hydrocarbon taxogen in catalytically effective amounts of a free radical generating initiator in a reaction zone, the telogen to taxogen molar ratio in the reaction zone being greater than about 1:1 as measured on the effluent stream from the reaction zone, at a temperature ranging from about 125.degree. C. to about 275.degree. C. and that a pressure varying from about 2000 psi to about 10,000 psi.
Type:
Grant
Filed:
March 20, 1974
Date of Patent:
May 22, 1979
Assignee:
Dart Industries Inc.
Inventors:
Michael Erchak, George E. Cremeans, Elmer J. Bradbury
Abstract: Phosphorus oxytrichloride modified titanium trichloride polymerization catalysts of improved efficiency and/or isotacticity are obtained when the modification reaction is carried out in the presence of methylene chloride.
Abstract: An integrated process for the recovery of copper from impure copper bearing materials is provided by leaching the copper bearing material with sulfuric acid to convert the copper value to the soluble copper sulfate, selectively extracting the copper value from the leach liquor by contacting the liquor with an organic extractant stripping the copper from the organic copper extractant by contacting with liquor of enhanced acid content resulting from a subsequent reduction step, thus regenerating the organic extractant, contacting and thus reacting the acidified copper containing solution with an organic solution of amine extractant to reduce its acid concentration to a desired level, and recovering the copper metal by reacting the copper containing solution of lowered acid content with sulfur dioxide.
Abstract: Aqueous hydrogen peroxide solutions used in metal dissolution processes are effectively stabilized against decomposition caused by metal ion contaminants by addition of saccharin or an alkali-metal salt of saccharin to the solutions.
Abstract: Clean etchings at high rates are obtained using a solution containing sulfuric acid, hydrogen peroxide, a catalytic amount of a selenium compound of a +4 oxidation state and t-butyl hydroperoxide.
Type:
Grant
Filed:
November 8, 1977
Date of Patent:
February 20, 1979
Assignee:
Dart Industries Inc.
Inventors:
Ronald A. Kent, John L. H. Allan, Philip D. Readio
Abstract: An electrolytic plating cell is provided, wherein by means of flow directional baffle arrangements a rapid, uniform parallel movement of the electrolyte past all electrode surfaces can be maintained, while minimizing energy losses in moving the electrolyte.
Abstract: Improved metal dissolution rates are obtained when using a solution containing sulfuric acid, hydrogen peroxide and a catalytic amount of a thiosulfate of sodium or potassium.
Abstract: A method useful in the regeneration of a spent chromic acid-sulfuric acid plastic etch solution and also in the recovery of such etchant chemicals from rinse water associated with a plastic etching process, which method involves an electrolytic treatment, in which oxidation of trivalent chromium impurities to the serviceable hexavalent state takes place simultaneously with expulsion of organic impurities from the solution.
Type:
Grant
Filed:
April 20, 1976
Date of Patent:
October 3, 1978
Assignee:
Dart Industries Inc.
Inventors:
Theodore Frank Korenowski, Leslie Emery Lancy
Abstract: A polyolefin composition having excellent stability against degradation caused by exposure to heat and oxygen in the presence of copper, which composition is stabilized with a synergistic stabilizer system containing at least one phenolic antioxidant and calcium stearate.
Abstract: Novel coupling agents for use in filled polymers to improve physical properties e.g. melt flow and impact strength, which agents are organic borates containing at least one functional group reactive with the filler and at least one functional group compatible with the polymer.
Type:
Grant
Filed:
December 15, 1976
Date of Patent:
February 14, 1978
Assignee:
Dart Industries, Inc.
Inventors:
Marvin M. Fein, Birendra K. Patnaik, Frank K. Y. Chu
Abstract: Polyolefins pigmented with copper phtalocyanine complexes are rendered stable against heat and oxidation by addition of a metal chelating agent.
Type:
Grant
Filed:
July 14, 1976
Date of Patent:
January 3, 1978
Assignee:
Dart Industries, Inc.
Inventors:
Kornel Dezso Kiss, John Leslie Hugh Allan, Marvin Michael Fein
Abstract: Polypropylene molding compositions of improved impact strength are obtained by subjecting certain block copolymers of ethylene and propylene to controlled oxidative degradation.
Abstract: An extraction resistant, smoke resistant linear polymeric phenolic antioxidant containing sulfonic acid groups or salts thereof in at least a portion of the recurring phenolic ring groups.
Type:
Grant
Filed:
April 15, 1976
Date of Patent:
November 22, 1977
Assignee:
Dart Industries Inc.
Inventors:
John Leslie Hugh Allan, John James Roderick