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Production of hexabromocyclododecane of enhanced gamma isomer content

A technology of dodecatriene and dioxane, applied in the field of preparing hexabromocyclododecane, can solve the problems of increasing a few percentage points, reducing yield, increasing initial melting point and the like

Inactive Publication Date: 2005-02-23
ALBEMARLE CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Mixtures of the three isomers show an extended melting point range, but it is generally accepted that increasing the gamma isomer content of the HBCD product also increases the initial melting point of the product
French patent FR 1,553,410 can add 10% water to acetic acid or propionic acid solvent to increase the yield, but the yield is only increased by a few percentage points
Therefore, the prior art shows that for the extraction of HBCD from organic solvents, the addition of water gives only a small increase in yield

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment I

[0053] A 500 ml multi-neck ball bottom flask was charged with 90 g of pure 1,2-diethoxyethane and 25 g of 60% HBr in water (0.19 moles of HBr). Cyclododecatriene (CDT) (30 grams, 0.19 moles, 50% loading) and bromine (93.3 grams, 0.58 moles) were prepared for the co-feed. Part of the bromine (3 g) was pre-charged to the reactor before the CDT feed was started. The CDT and bromine feed rates were adjusted so that both feeds ended nearly simultaneously. The reaction temperature should not exceed 28°C during the feed. For operational convenience, the reaction mass was then stirred overnight at ambient conditions. At this point, a thermal processing step is appropriate in order to convert some of the tetrabromocyclododecane intermediates to complementary products. Therefore, the reaction mass is maintained at 75-80°C for about 180 minutes. After this period, the reaction mass was cooled to ambient temperature. 750 mg of Monawet MO-70 (dioctyl sodium sulfosuccinate, Mona Indust...

Embodiment II～X

[0054] Embodiment II~XXV

[0055] The general procedure described below was used to obtain the isomer data in Table 1. The reactor used was a four-neck small test flask with an open head 100 ml flask. A typical test was as follows: a flask was charged with 39.1 grams of glyme (1,2-dimethoxyethane) and 310.9 grams of 60% HBr in water (13% HBr based on solvent charge). The contents were frozen to 10°C using an ice bath, at which point the co-feeds were initiated. 1 / 32 at flow rates of 1.0 and 1.2 mL / min, respectively N Teflon tubing with bromine (26.2 grams, 5% xs) and CDT (8.4 grams, 40% fill) added subsurface. Bromine was added slightly ahead of the CDT, with a total pre-addition of 15 grams. When the feed was complete, the ice bath was removed and the slurry was stirred for 15 minutes before warming the reaction slurry with a 70°C water bath for 15 minutes. HPLC analysis of the slurry was performed at this point. This description is for a 40% loading test; different loa...

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PUM

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Abstract

Hexabromocyclododecane with enhanced gamma isomer content is produced by brominating cyclododecatriene in a liquid medium comprised of (1) at least 50 wt% of at least one liquid inert organic solvent other than 1,4-dioxane having a solubility in water of at least 1 wt% at 25 DEG C, and (2) water in an amount of up to 40 wt%, in the presence of (3) 0.5 to 30 wt% of bromide ion (Br[-]), each wt% being based on the total weight of the liquid portion of the liquid medium.

Description

technical field [0001] The present invention relates to an improved process for the preparation of hexabromocyclododecane. The method can produce hexabromocyclododecane products with increased gamma isomer content. Background technique [0002] Hexabromocyclododecane (1,2,5,6,9,10-hexabromocyclododecane, HBCD) is a well known flame retardant used in various thermoplastics. HBCD is generally composed of three isomers called alpha, beta and gamma. Among the three isomers, the pure gamma isomer has the highest melting point. Mixtures of the three isomers show an extended melting point range, but it is generally believed that increasing the gamma isomer content of the HBCD product also increases the initial melting point of the product. HBCD products with a higher initial melting point are most desired in the industry, and a number of methods have been explored to increase the gamma isomer content of HBCD. One of the methods includes washing, pulverizing, or recrystallizing ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C17/02C07C23/02
CPCC07C17/02C07C23/02
Inventor 约翰K·肯德尔
Owner ALBEMARLE CORP