- PREPARATION OF HIGH ASSAY DECABROMODIPHENYLALKANE PRODUCT WITH LOW OCCLUDED FREE BROMINE CONTENT
-
A high assay decabromodiphenylalkane product in which the alkylene group contains in the range of about 1-10 carbon atoms and has an occluded free bromine content of a liquid phase reaction mixture, at least one α,ω-diphenylalkane having an alkylene group of 1-10 carbon atoms, with a limited excess of bromine, in the presence of an aluminum, aluminum halide or a ferric halide catalyst in which the original halogen atoms of such halides are chlorine atoms, bromine atoms, or both. The limited excess of bromine is such that the maximum excess amount of bromine used in conducting the reaction is about 20 mole % relative to the stoichiometric amount required to convert the amount of α,ω-diphenylalkane used to decabromodiphenylalkane. Crude high assay decabromodiphenylalkane product is prepared without use of heat treatment, oven ageing, or grinding or other forms of pulverization.
- -
-
Page/Page column 7; 8
(2011/02/24)
-
- Process for separation of bromine from gaseous hydrogen bromide and use of such process in production of decabromodiphenylethane
-
Bromine is scrubbed from a gaseous mixture of bromine and hydrogen bromide by passing the mixture into a mixture formed from (i) diphenylethane and/or partially brominated diphenylethane with average bromine number less than about 2 and (ii) a catalytic quantity of iron and/or iron halide in which the halogen atoms are bromine atoms and/or chlorine atoms. Component (i) is brominated, and during such bromination, the mixture is kept hot enough to melt the organics to provide a liquid phase in the scrubber. Gaseous mixtures of bromine and hydrogen bromide are formed in processes of the invention in which decabromodiphenylethane products are produced using the partially brominated diphenylethane as feed to the bromination, which is conducted using an aluminum-based catalyst. Effective ways of removing iron catalyst residues from partially brominated diphenylethane or from decabromodiphenylethane product are also described.
- -
-
Page/Page column 13-14; 16
(2008/12/07)
-
- PREPARATION AND PROVISION OF HIGH ASSAY DECABROMODIPHENYLETHANE
-
High assay, reaction-derived decabromodiphenylethane product is prepared by feeding (i) diphenylethane or (ii) partially brominated diphenylethane having an average bromine number less than about two, or (iii) both of (i) and (ii), into the liquid confines of a reaction mixture. Such reaction mixture is (a) formed from components comprised of excess liquid bromine and aluminum-based Lewis acid bromination catalyst, and (b) maintained at one or more elevated reaction temperatures of from about 45°-90° C., and at least when elevated pressure is needed to keep a liquid state in the reaction mixture at the temperature(s) used, the reaction mixture is at such an elevated pressure, whereby ar-bromination occurs. The feeding is conducted at a rate slow enough to form high assay reaction-derived decabromodiphenylethane product, which is an effective flame retardant.
- -
-
Page/Page column 6-7
(2008/12/07)
-
- PREPARATION AND PROVISION OF HIGH ASSAY DECABROMODIPHENYLETHANE
-
High assay reaction-derived decabromodiphenylethane product is produced and provided. The process comprises feeding diphenylethane, a partially brominated diphenylethane, or both subsurface into the liquid phase of a reaction mixture formed from components comprising excess liquid bromine and aluminum-based Lewis acid bromination catalyst. The temperature of the reaction mixture, the catalyst concentration in the excess bromine in the reaction mixture, and the feed time are coordinated in the processes to produce high assay reaction-derived decabromodiphenylethane product. Ways of effecting such coordination are described.
- -
-
Page/Page column 4-5
(2008/12/07)
-
- PROCESSING OF SOLID BROMINATED AROMATIC ORGANIC COMPOUNDS CONTAINING OCCLUDED BROMINE
-
Solid-state highly brominated compounds such as solid brominated flame retardants with bromine contents of at least about 60 wt % often contain occluded bromine. Because of their high bromine contents, such compounds have relatively low solubility in common organic solvents. Despite this low solubility, the content of occluded bromine in such solid brominated compounds is effectively reduced by agitating a concentrated agitated slurry of the compound in an inert solvent at a suitable temperature for at least about 1 hour. Thereafter, solids with reduced content of occluded bromine are isolated or recovered from the slurry. Novel products having substantially reduced or eliminated occluded bromine contents and other very desirable characteristics are also provided.
- -
-
Page/Page column 9
(2008/12/05)
-
- Reaction of 2,3,4,5,6-pentabromobenzyl bromide with 2,4,6-triphenylpyranyl
-
The main process in the reaction of 2,4,6-triphenylpyranyl with 2,3,4,5,6-pentabromobenzyl bromide in 2-propanol is electron transfer to give 2,4,6-triphenylpyrylium bromide and 2,3,4,5,6-pentabromobenzyl radical. 2004 MAIK "Nauka/Interperiodica".
- Burtasov,Mishunyaeva,Pryanichnikova,Shishkin,Tanaseichuk
-
p. 1400 - 1402
(2007/10/03)
-
