Did You Know...
...that two musicians were responsible for the invention of color print film? Fascinated by photography, Leopold Godowsky and Leopold Mannes worked together to produce an easy-to-use, practical color film. They worked full time as music teachers and gave concerts while experimenting during their off hours in Mannes' kitchen. Their success earned them full-time, well-paying jobs at Kodak and their efforts resulted in Kodachrome film, which was introduced in 1935.
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| Number | Title | Issue Date |
| 7993622 | Method for preparing dithionite The present invention relates to a method for preparing dithionite solution with a reaction wherein sodium bisulfite is reduced with sodium borohydride solution to obtain dithionite, wherein the rise of the pH of the solution is prevented by adjusting the pH with ca... | 08/09/2011 |
| 7968076 | Method for producing sodium dithionite The invention relates to a process for the preparation of sodium dithionite, comprising the steps (a) provision of a synthesis batch comprising sodium formate, sulfur dioxide and an alkaline sodium compound in aqueous methanolic solution with formation ... | 06/28/2011 |
| 7163564 | Method for brightening virgin mechanical pulp A method for brightening virgin mechanical pulp. The method comprises combining: (i) an aqueous solution comprising sodium borohydride and sodium hydroxide; and (ii) an aqueous solution comprising sodium bisulfite, in a chemical mixer and adding output of the chemic... | 01/16/2007 |
| 7029554 | Method for brightening pulp with hydrosulfite solution generated from borohydride and bisulfite A method for brightening pulp at a pH from 4.5 to 9. The method comprises the steps of: (a) combining an alkali metal borohydride, an alkali metal hydroxide, an alkali metal bisulfite and phosphoric acid to form a reducing solution; and (b) adding the reducing solut... | 04/18/2006 |
| 6555078 | Method of preparing lithium salts The present invention provides an inexpensive process for the preparation of lithium salts of formula LiX having a desired or required level of purity using lithium chloride and lithium sulfate. In the process of the invention, a lithium salt selected fro... | 04/29/2003 |
| 5391526 | Situ method for producing hydrosulfite bleach and use thereof A process for reacting metallic iron with sulfur dioxide (SO2) gas in the presence of water and bleachable matter, especially iron-contaminated kaolin clay, whereby the kaolin or the like is bleached in situ and the viscosity of the kaolin is l... | 02/21/1995 |
| 5336479 | High yield sodium hydrosulfite generation An improved high yield process and apparatus for producing sodium hydrosulfite by simultaneously contacting a first reaction mixture of sodium borohydride, sodium hydroxide, and water with a second reaction mixture of an acidic sulfur-containing compound ... | 08/09/1994 |
| 5296210 | Stabilized sodium dithionite A process for stabilizing sodium dithionite is disclosed, whereby a selected additive is used.... | 03/22/1994 |
| 5283046 | Method for re-use of aqueous co-product from manufacture of sodium dithionite Aqueous co-product, produced by distillation of reaction filtrate from a batch reaction for manufacturing sodium dithionite by reacting sodium formate, sodium hydroxide, and sulfur dioxide in aqueous methanol solution, is rapidly evaporated to remove abou... | 02/01/1994 |
| 5188807 | Apparatus for producing high yield sodium hydrosulfite An improved high yield apparatus for producing sodium hydrosulfite is disclosed wherein sodium borohydride, sulfur dioxide, sodium hydroxide and sodium bisulfite are reacted. Improved results are obtained according to the invention by a novel feed system ... | 02/23/1993 |
| 5122279 | Ferrous dithionite process and compositions for removing dissolved heavy metals from water Heavy metal ions react with ferrous dithionite in acidic aqueous solution. They are reduced to metallic particles that are suitable for recycling and reuse when recovered from the acidic water. When chelating agents are present, they are deactivated by bo... | 06/16/1992 |
| 5114698 | Method for stabilizing sodium dithionite A method of stabilizing sodium dithionite is disclosed which comprises exposing a quantity of sodium dithionite to a quantity of amino material under pressure, wherein the partial pressure of amino material is at least 0.5 atmospheres.... | 05/19/1992 |
| 5098679 | Purification of alkali metal hydrosulfite solutions A process for treating an alkali metal hydrosulfite solution which comprises contacting the alkali metal hydrosulfite solution with aluminum in a reaction mixture, and admixing carbon dioxide gas with the reaction mixture to remove dissolved aluminum as a... | 03/24/1992 |
| 5094833 | High yield sodium hydrosulfite generation An improved high yield process and apparatus for producing sodium hydrosulfite by reacting sodium borohydride, sulfur dioxide, sodium hydroxide, and sodium bisulfite is provided. The improved result of the invention is obtained by a feed system that requi... | 03/10/1992 |
| 5034210 | Method of reducing ethylene oxide emissions Vent gas from the condenser-scrubber system of a reactor, in which dithionites are made by reacting a formate, sulfur dioxide, and an alkali in aqueous methanol, is reduced in its ethylene oxide content to less than 10 ppm maintaining the ratio of sulfur ... | 07/23/1991 |
| 5034202 | Removal of thiosulfate from hydrosulfite solutions A process for treating an alkali metal hydrosulfite solution which comprises contacting the alkali metal hydrosulfite solution, having a residual alkalinity of from about 1 to about 20 grams per liter of hydroxide ion, with aluminum. The process of the in... | 07/23/1991 |
| 5006327 | Alkali metal hydrosulfite solutions An aqueous solution comprising alkali metal hydrosulfite and hydroxide ions in an amount to provide a residual alkalinity of at least 0.25 moles per liter results in the decomposition of thiosulfate ions present and inhibits their formation during storage... | 04/09/1991 |
| 4973471 | Method for producing dust-free sodium dithionite There is disclosed a method for the production of dust-free sodium dithionite from the reaction of a alkaline formate sulfur dioxide and an alkaline metal agent in the presence of a thiosulfate reactive compound by introducing a water-soluble polymer havi... | 11/27/1990 |
| 4919755 | Process for bleaching Process for bleaching of materials, at which an aqueous solution of borohydride containing borohydride corresponding to from 15 to 35 percent by weight of sodium borohydride and hydroxylic ions corresponding to not more than 10 percent by weight of NaOH i... | 04/24/1990 |
| 4871373 | Continuous preparation of solutions of low viscosity solvents and high viscosity, pasty products Solutions of low viscosity solvents and high viscosity, pasty products, for example water and sodium dithionite formulations, are prepared in a continuous manner in a matter of seconds in static and dynamic mixers connected in series while at the same tim... | 10/03/1989 |
| 4859447 | Process for the production of sodium hydrosulfite An improved high yield process and apparatus for producing sodium hydrosulfite by reacting sodium borohydride, sulfur dioxide, sodium hydroxide and sodium bisulfite is disclosed. A continuously recirculating split process stream may be used along with con... | 08/22/1989 |
| 4810483 | Process for producing anhydrous alkali metal hydrosulfites A process for producing an anhydrous alkali metal hydrosulfite comprises contacting hydrate crystals of an alkali metal hydrosulfite with an alkaline aqueous solution of a dehydrating agent having a pH of at least about 7. The slurry formed is maintained ... | 03/07/1989 |
| 4788041 | Apparatus for the production of sodium hydrosulfite An improved high yield process and apparatus for producing sodium hydrosulfite by reacting sodium borohydride, sulfur dioxide, sodium hydroxide and sodium bisulfite is disclosed. A continuously recirculating split process stream may be used along with con... | 11/29/1988 |
| 4729886 | Method of preparing reproducibly stable aqueous suspensions of sodium dithionite for woodpulp bleaching Aqueous sodium dithionite slurries or suspensions, which are nonsettling during shipment thereof and are thereafter pumpable after storage at 32°-40° F. for at least fourteen days, comprise, on a weight basis, about 34% of sodium dithionite, about 0.17%... | 03/08/1988 |
| 4693880 | Process for producing dithionites A process for producing an anhydrous dithionite which comprises reacting formic acid or a formate, an alkaline compound and sulfur dioxide in the presence of water and an organic solvent, filtering the resulting dithionite crystal from the mother liquor, ... | 09/15/1987 |
| 4680136 | Method for preparing compositions which can be used in the production of sodium dithionite; and the use of such compositions There is provided a method for producing compositions which can be used for preparing sodium dithionite, in which sulphur dioxide is brought into contact with a recirculating aqueous solution of sodium hydroxide and previously absorbed sulphur dioxide to ... | 07/14/1987 |
| 4676961 | Stabilized water-containing sodium dithionite formulations which have been rendered alkaline Stabilized water-containing sodium dithionite formulations which have been rendered alkaline have the consistency of a pumpable paste. They additionally contain readily soluble sodium salts and/or potassium salts which are inert to sodium dithionite and w... | 06/30/1987 |
| 4622216 | Treatment of sodium dithionite reaction mixture A method is taught for increasing the yield of anhydrous sodium dithionite by adding an organic compound that is thiosulfate reactive to a batch reactor containing a puddle solution of methanol and fed with formic acid or an alkali formate as a first feed... | 11/11/1986 |
| 4614647 | Stabilized sodium dithionite formulations containing inert organic liquids, and the use of these formulations Sodium dithionite formulations containing inert organic liquids have the consistency of a pumpable paste.... | 09/30/1986 |
| 4590058 | Process for producing high purity solutions of alkali metal hydrosulfites High purity solutions of alkali metal hydrosulfites having low concentrations of alkali metal thiosulfates are produced in a process which comprises feeding an alcohol-free aqueous solution of an alkali metal hydrosulfite containing an alkali metal thiosu... | 05/20/1986 |
| 4582510 | Stabilized dithionite solutions Guar and xanthan gums are used as additives to sodium dithionite aqueous solutions for enhancing the stability of such solutions when in contact with air and used for vat dyeing of textiles and bleaching. The gums are added at levels of 0.1-0.2% by wt. an... | 04/15/1986 |
| 4534954 | Sodium hydrosulfite slurries Aqueous sodium dithionite slurries, which are non-settling during shipment thereof and are thereafter pumpable, and a method for their manufacture are provided. The slurries contain at least 25% by weight of crystalline pure sodium dithionite and at least... | 08/13/1985 |
| 4388291 | Process for the production of dithionites An improvement in the process for producing anhydrous dithionites by reacting formic acid or a formate with an alkali compound and sulfurous acid anhydride in a mixture of water and organic solvent; filtering dithionite crystals from the mother liquor; an... | 06/14/1983 |
| 4357256 | Sodium hydrosulfite composition A bleaching composition comprises sodium hydrosulfite, hexamethylenetetramine and a water soluble sulfite such as sodium sulfite or ammonium sulfite, or further a polyphosphate such as a pyrophosphate or a tripolyphosphate and is used in bleaching pulp wi... | 11/02/1982 |
| 4283303 | Process for manufacture of stable sodium dithionite slurries Substantially stable slurries containing 30-35% by weight of sodium dithionite are manufactured by evaporating sodium dithionite solutions while maintaining the heating medium at 220°-250° F. and the solution and slurry at 110°-155° F. under a vacuum ... | 08/11/1981 |
| 4237318 | Manufacture of aqueous methanolic solution of sodium formate In a process for the manufacture of sodium dithionite by reacting sulfur dioxide with sodium formate and aqueous sodium hydroxide solution in the presence of methanol, an aqueous methanolic solution of sodium formate is first produced by reacting carbon m... | 12/02/1980 |
| 4218429 | Production of alkali metal dithionites from sulfur dioxide, alkali metal formates, and slurried bisulfite compounds at high reactant concentrations A batch process, in which a sodium bisulfite compound is the alkaline agent, is described for producing anhydrous sodium dithionite at high productivity by reduction of sulfur dioxide with the formate radical in concentrated aqueous methanolic solution. M... | 08/19/1980 |
| 4199472 | Oxygen absorbent composition An oxygen absorbent composition consisting essentially of (a) an oxygen absorbent comprising a dithonite as a main component and (b) a fiber material in an amount of from about 1 to about 50 parts by weight per 100 parts by weight of the oxygen absorbent ... | 04/22/1980 |
| 4177247 | Process for producing dithionites Dithionites are produced by reacting hydroquinones with bisulfites, pyrosulfites, alkyl sulfites, or aryl sulfites, substances capable of forming these salts upon reacting with sulfur dioxide or sulfurous acid, and sulfur dioxide or sulfurous acid.... | 12/04/1979 |
| 4157980 | Hydrosulfite preparation Aluminum metal is activated with hydrochloric acid and then reacted with an aqueous solution of sulfur dioxide to produce an aluminum hydrosulfite (dithionite) liquor useful for bleaching materials such as clay. The aluminum hydrosulfite can be converted ... | 06/12/1979 |
