Purification of bisphenols by removing residual solvent
First Claim
1. A process for purifying a bisphenol to remove small amounts of organic solvent remaining from a crystallization which comprises (a) adding bisphenol crystals containing said solvent to water maintained at a temperature which will produce a water-bisphenol molten phase, (b) maintaining that temperature for a period of time sufficient to permit the organic solvent to transfer to said water, (c) flash distilling substantially all of said solvent away from said water, (d) cooling said molten bisphenol-water phase to precipitate the crystalline bisphenol, and (e) separating said crystalline bisphenol from said water and (f) drying said crystalline bisphenol.
1 Assignment
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Accused Products
Abstract
Occluded organic solvent is removed from bisphenol crystals by placing in water maintained at a temperature sufficient to form a molten water-bisphenol phase, holding at that temperature for a time sufficient to transfer the organic solvent to the water phase, flash distilling the organic solvent, cooling molten water-bisphenol phase to produce crystallization and thereafter recovering the bisphenol.
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Citations
7 Claims
- 1. A process for purifying a bisphenol to remove small amounts of organic solvent remaining from a crystallization which comprises (a) adding bisphenol crystals containing said solvent to water maintained at a temperature which will produce a water-bisphenol molten phase, (b) maintaining that temperature for a period of time sufficient to permit the organic solvent to transfer to said water, (c) flash distilling substantially all of said solvent away from said water, (d) cooling said molten bisphenol-water phase to precipitate the crystalline bisphenol, and (e) separating said crystalline bisphenol from said water and (f) drying said crystalline bisphenol.
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7. A process for purifying a bisphenol to remove small amounts of organic solvent remaining from a crystallization which comprises (a) adding bisphenol crystals containing said solvent to water maintained at a temperature which will produce a water-bisphenol molten phase, (b) maintaining that temperature for a period of time sufficient to permit the organic solvent to transfer to said water, (c) flash distilling substantially all of said solvent away from said water, (d) stripping said water from said molten water-bisphenol phase, (e) separating solid bisphenol as a prill or flake and (f) drying said prill or flake.
Specification