Claims for Patent: 4,786,385

Summary for Patent: 4,786,385

Title:	Method of preventing undesirable gas generation between electrodes of an electrocoagulation printing system
Abstract:	The invention is concerned with a method of preventing undesirable gas generation between a pair of opposite, electrically energized negative and positive electrodes spaced from one another by a gap filled with an aqueous electrolyte solution. According to the invention, the positive electrode is coated with an olefinic substance to form micro-droplets thereof on the surface of the positive electrode prior to electrically energizing the electrodes such that upon electrical energization hydrogen generated as a result of electrolysis is consumed by reaction with the olefinic substance to convert same by hydrogenation into an ethylenically saturated product, the hydrogenation reaction being carried out in the presence of a metallic oxide catalyst. In this manner, undesirable hydrogen generation and accumulation at the negative electrode is prevented. The method of the invention is particularly useful in electrocoagulation printing systems where an image is reproduced by electrocoagulation of an electrolytically coagulable colloid on a positive electrode to form dots of coagulated colloid representative of a desired image, the invention enabling the electrical resistance which is created at the interface of the negative electrode by the accumulation of hydrogen and causes an erratic formation of the dots of coagulated colloid to be suppressed.
Inventor(s):	Castegnier; Adrien (Outremont, CA)
Assignee:	Elcorsy Inc. (St.-Laurent, CA)
Application Number:	07/061,224
Patent Claims:	1. A method of preventing undesirable gas generation between a pair of opposite, electrically energized negative and positive electrodes spaced from one another by a gap filled with an aqueous electrolyte solution, which comprises coating the positive electrode with an olefinic substance to form micro-droplets thereof on the surface of the positive electrode prior to electrically energizing said electrodes such that upon electrical energization gas generated as a result of electrolysis is consumed by reaction with said olefinic substance, said reaction being carried out in the presence of a metallic oxide catalyst, thereby preventing undesirable gas generation between said electrodes. 2. A method as claimed in claim 1, wherein said olefinic substance is selected from the group consisting of unsaturated fatty acids, unsaturated vegetable oils and waxes. 3. A method as claimed in claim 2, wherein said olefinic substance is an unsaturated fatty acid selected from the group consisting of arachidonic acid, linoleic acid, linolenic acid, oleic acid and palmitoleic acid. 4. A method as claimed in claim 2, wherein said olefinic substance is an unsaturated vegetable oil selected from the group consisting of corn oil, linseed oil, olive oil, peanut oil and soybean oil. 5. A method as claimed in claim 3, wherein said unsaturated fatty acid is linoleic or oleic acid and wherein said positive electrode is made of stainless steel having a chromium oxide surface layer, said chromium oxide acting as said metallic oxide catalyst. 6. A method as claimed in claim 1, wherein said olefinic substance is an unsaturated vegetable oil and is applied to said positive electrode in the form of a dispersion containing said metallic oxide catalyst. 7. A method as claimed in claim 6, wherein said metallic oxide catalyst is present in an amount of about 1 to about 10% by weight, based on the total weight of said dispersion. 8. A method as claimed in claim 6, wherein said metallic oxide catalyst is selected from the group consisting of aluminum oxide, ceric oxide, chromium oxide, cupric oxide, cuprous oxide, ferric oxide, ferrous oxide, lead oxide, magnesium oxide, manganese oxide and zinc oxide. 9. A method as claimed in claim 8, wherein said dispersion contains about 88 wt. % of an unsaturated vegetable oil selected from the group consisting of olive oil, corn oil and peanut oil, about 2 wt. % of oleic acid and about 10 wt. % of ferric oxide. 10. In a method of reproducing an image by electrocoagulation of an electrolytically coagulable colloid, wherein a layer of an aqueous colloidal dispersion containing an electrolytically coagulable colloid, water and a soluble electrolyte is interposed between at last one pair of opposite, electrolytically inert negative and positive electrodes spaced from one another by a gap filled with said aqueous colloidal dispersion and said electrodes are electrically energized to pass electric current through the layer at selected points to cause point-by-point selective coagulation and adherence of the colloid on the positive electode and formation of a series of corresponding dots of coagulated colloid representative of a desired image, the improvement which comprises coating the positiv electrode with an olefinic substance to form micro-droplets thereof on the surface of the positive electrode prior to electrically energizing said electrodes such that upon electrical energization hydrogen generated as a result of electrolysis is consumed by reaction with said olefinic substance said reaction being carried out in the presence of a metallic oxide catalyst, thereby preventing undesirable gas generation and accumulation at the between the electrodes. 11. A method as claimed in claim 10, wherein said olefinic substance is selected from the group consisting of unsaturated fatty acids, unsaturated vegetable oils and waxes. 12. A method as claimed in claim 11, wherein said olefinic substance is an unsaturated fatty acid selected from the group consisting of arachidonic acid, linoleic acid, linolenic acid, oleic acid and palmitoleic acid. 13. A method as claimed in claim 11, wherein said olefinic substance is an unsaturated vegetable oil selected from the group consisting of corn oil, linseed oil, olive oil, peanut oil and soybean oil. 14. A method as claimed in claim 12, wherein said unsaturated fatty acid is linoleic or oleic acid and wherein said positive electrode is made of stainless steel having a chromium oxide surface layer, said chromium oxide acting as said metallic oxide catalyst. 15. A method as claimed in claim 10, wherein said olefinic substance is an unsaturated vegetable oil and is applied to said positive electrode in the form of a dispersion containing said metallic oxide catalyst. 16. A method as claimed in claim 15, wherein said metallic oxide catalyst is present in an amount of about 1 to about 10% by weight, based on the total weight of said dispersion. 17. A method as claimed in claim 15, wherein said meallic oxide catalyst is selected from the group consisting of aluminum oxide, ceric oxide, chromium oxide, cupric oxide, cuprous oxide, ferric oxide, ferrous oxide, lead oxide, magnesium oxide, manganese oxide and zinc oxide. 18. A method as claimed in claim 17, wherein said dispersion contains about 88 wt. % of an unsaturated vegetable oil selected from the group consisting of olive oil, corn oil and peanut oil, about 2 wt. % of oleic acid and about 10 wt. % of ferric oxide. 19. A method as claimed in claim 10, wherein said dots of coagulated colloid are contacted with an end-use support to cause transfer of the coagulated colloid onto said end-use support and thereby imprint said end-use support with said image, and wherein said olefinic substance is an unsaturated vegetable oil such that upon reaction the micro-droplets of vegetable oil are converted into micro-droplets of fat weakening the adherence of said dots of coagulated colloid to said positive electrode and thereby facilitating the transfer of said coagulated colloid onto said end-use support upon contact therewith. 20. A method as claimed in claim 12, wherein said positive electrode is made of stainless steel having a chromium oxide surface layer, and wherein said unsaturated fatty acid is oleic acid and is applied in the form of a dispersion containing ferric oxide as said metallic oxide catalyst, said electrolytically coagulable colloid comprising a linear polyacrylamide having a molecular weight of about 250,000.

Details for Patent 4,786,385

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Aimmune Therapeutics, Inc.	PALFORZIA	peanut (arachis hypogaea) allergen powder-dnfp	Powder	125696	January 31, 2020	4,786,385	2007-06-12