摘要:
1,1,1-Trifluoro-2,2-dichloroethane is prepared by reacting, in the gas phase, 1,1,1-trifluoro-2-chloroethane with chlorine. The formation of the by-product 1,1,1-trifluorotrichloroethane is prevented by effecting the reaction with a chlorine/organic compound molar ratio of not higher than 1 at a temperature of from 350°C to 450°C and with residence times of the reagents in the reactor of from 5 to 25 seconds.
摘要:
Described are imido-percarboxylic acids having the general formula (I): wherein R and R₁, the same or different from each other, represent hydrogen atoms and optionally substituted alkyl groups or R and R₁ form an optionally substituted cycloaliphatic ring together with the carbon atoms to which they are linked; the symbol ..... indicates a single or olefinic double bond; R₂ represents hydrogen, alkyl or OH, and n is an integer different from 0. Also described is a process for the preparation of said percarboxylic acids and their use as bleaching agents.
摘要:
A solvent composition for defluxing printed circuits at room temperature comprises 4 to 10% ethanol , 0.5 to 1.5% a C₁₋₃ nitroalkane, 0.5 to 10% of a C₁₁₋₁₈ alkyl mono- or diester of phosphoric acid and balance perfluorochlorocarbon. In the defluxing process the printed circuit is immersed in the composition. The composition is good for dissolving flux but does not corrode the apparatus.
摘要:
Aqueous compositions containing from 1% to 40% by weight of a perfluoropolyethereal compound having a molecular weight ranging from 400 to 5,000 and containing carboxylic end groups, which are salified with an organic or inorganic base, said compositions being useful as lubricating/refrigerating liquids in the plastic cold processing processes of metals, in particular rolling, dishing, drawing and the like.
摘要:
Process for preparing perfluoro-(2-bromoethylvinylether) of formula BrF₂C-CF₂-O-CF=CF₂ by dechlorination of 2-bromo-1′,2′-dichloroperfluorodiethylether of formula BrF₂C-CF₂-O-CClF-CClF₂ in the presence of copper and in a solvent of formula wherein R₁ and R₂ are H, CH₃ or C₂H₅ and R₃ is CH₃ or C₂H₅; preferably at temperatures of from 100 to 160°C.
摘要:
Disclosed are heterocyclic (poly)percarboxylic acids with an amide function having the formula: R - CH₂ m - R′ (I) wherein: R and R′, the same or different from each other, represent hydrogen or a group of the formula: provided that at least one of R and R′ is different from H, and wherein R" represents a hydrogen atom or substituent which is inert towards the active oxygen of the percarboxylic group and/or the preparation conditions; m represents an integer from 1 to 12; n is selected from 0,1 and 2; p is an integer of from 1 to 3. Also described is a process for their preparation and their use as bleaching agents.
摘要:
Waterproofing sheets or membranes comprising a support composed of or comprising a vulcanized polyolefinic rubber enclosed in a sandwich-type structure between two layers of bituminous composition selected from:
(1) compositions comprising, by weight,
(A) 60-90% of bitumen (B) 3.5-20% of EPM or EPDM rubber (C) 3-20% of HD polyethylene (D) 1.5-10% of EVA copolymer (E) 0-10% of isotactic polypropylene (F) 0-20% of inorganic filler;
(2) compositions comprising, by weight,
(A) 60-90% of bitumen (B) 40-10% of elastomeric styrene-butadiene copolymer (C) 0-20% of amorphous polypropylene (D) 0-20% of inorganic filler.