Method for making salts hydroxy-substituted hydrocarbons

A method for preparing a disodium salt of a dihydroxy-substituted aromatic hydrocarbon which comprises the steps of:

• (i) contacting at least one dihydroxy-substituted aromatic hydrocarbon with sodium hydroxide in solvent media comprising water, wherein the amounts of dihydroxy-substituted aromatic hydrocarbon and sodium hydroxide deviate from stoichiometry by no more than plus/minus 0.4 mole %, and wherein the alkali metal salt is essentially soluble in the solvent media;
• (ii) devolatilizing the solvent media comprising the disodium salt by spraying the solvent media into a substantially water-immiscible organic solvent in a vessel comprising subsurface baffles, at least one agitator and at least one spray nozzle for introduction of solvent media, wherein said organic solvent is at a temperature in a range of between about 110° C. and about 200° C., wherein heat is provided to the organic solvent by circulating said solvent, optionally comprising disodium salt, through a pump-around loop comprising a centrifugal pump, and a spiral beat exchanger or a self-cleaning reboiler;
• wherein the amount of water removed during devolatilizing is greater than about 99 wt. %;
• and wherein said salt is at a solids level in a range of between about 10% and about 20% following devolatilizing;
• and
• (iii) reducing the disodium salt particle size at least once in a slurry of the organic solvent.

A method for preparing the disodium salt of bisphenol A which comprises the steps of:

• (i) contacting bisphenol A with sodium hydroxide in solvent media comprising water, wherein the amounts of bisphenol A and sodium hydroxide deviate from stoichiometry by no more than plus/minus 0.4 mole %;
• (ii) devolatilizing the solvent media comprising the disodium salt by spraying the solvent media into ortho-dichlorobenzene in a vessel comprising subsurface baffles, at least one agitator and at least one spray nozzle for introduction of solvent media, wherein said ortho-dichlorobenzene is at a temperature in a range of between about 130° C. and about 180° C., wherein heat is provided to the ortho-dichlorobenzene by circulating said ortho-dichlorobenzene, optionally comprising disodium salt, through a pump-around loop comprising a centrifugal pump, and a spiral heat exchanger or a self-cleaning reboiler;
• wherein the amount of water removed during devolatilizing is greater than about 99 wt. %;
• and wherein said salt is at a solids level in a range of between about 10% and about 20% following devolatilizing;
• (iii) reducing the disodium salt particle size at least once in a slurry of ortho-dichlorobenzene to provide said disodium salt comprising less than 25% of particles with a diameter of greater than about 200 nm;
• and less than 2% of particles with a diameter of greater than about 500 nm, wherein the particle size is reduced using equipment which comprises one or more of a centrifugal pump, grinder, drop-down blender, particle size reduction homogenizer or delumper;
• and
• (iv) drying at least once to remove residual water remaining after step (iii), wherein said drying step comprises distilling ortho-dichlorobenzene and water from the vessel either with or without introduction of dry ortho-dichlorobenzene to the vessel to provide said disodium salt with an amount of water remaining after one or more drying steps of less than about 20 ppm.

A method for preparing an alkali metal salt of a hydroxy-substituted aromatic hydrocarbon which comprises the steps of:

• (i) contacting at least one hydroxy-substituted aromatic hydrocarbon with a base in solvent media comprising water and at least one water-soluble protic organic solvent, wherein the amounts of hydroxy-substituted aromatic hydrocarbon and base deviate from stoichiometry by no more than plus/minus 0.4 mole %, and wherein the alkali metal salt is essentially soluble in the solvent media;
• (ii) devolatilizing the solvent media comprising the salt by adding the solvent media into a substantially water-immiscible organic solvent in a vessel comprising subsurface baffles, at least one agitator and at least one inlet for introduction of solvent media, wherein said organic solvent is at a temperature in a range of between about 110° C. and about 200° C., wherein heat is provided to the organic solvent by circulating said solvent, optionally comprising disodium salt, through a pump-around loop comprising a centrifugal pump, and a spiral heat exchanger or a self-cleaning reboiler;
• wherein the amount of water removed during devolatilizing is greater than about 99 wt. %;
• and wherein said salt is at a solids level in a range of between about 10% and about 20% following devolatilizing;
• and
• (iii) reducing the salt particle size at least once in a slurry of the organic solvent.

A method for preparing the disodium salt of bisphenol A which comprises the steps of:

• (i) contacting bisphenol A with sodium hydroxide in solvent media comprising water and methanol, wherein the amounts of bisphenol A and sodium hydroxide deviate from stoichiometry by no more than plus/minus 0.4 mole %;
• (ii) devolatilizing the solvent media comprising the disodium salt by adding the solvent media to ortho-dichlorobenzene in a vessel comprising subsurface baffles, at least one agitator and at least one inlet for introduction of solvent media, wherein said ortho-dichlorobenzene is at a temperature in a range of between about 130° C. and about 180° C., wherein heat is provided to the ortho-dichlorobenzene by circulating said ortho-dichlorobenzene, optionally comprising disodium salt, through a pump-around loop comprising a centrifugal pump, and a spiral heat exchanger or a self-cleaning reboiler;
• wherein the amount of water removed during devolatilizing is greater than about 99 wt. %;
• and wherein said salt is at a solids level in a range of between about 10% and about 20% following devolatilizing;
• (iii) reducing the disodium salt particle size at least once in a slurry of ortho-dichlorobenzene to provide said disodium salt comprising less than 25% of particles with a diameter of greater than about 200 nm;
• and less than 2% of particles with a diameter of greater than about 500 nm, wherein the particle size is reduced using equipment which comprises one or more of a centrifugal pump, grinder, drop-down blender, particle size reduction homogenizer or delumper;
• and
• (iv) drying at least once to remove residual water remaining after step (iii), wherein said drying step comprises distilling ortho-dichlorobenzene and water from the vessel either with or without introduction of dry ortho-dichlorobenzene to the vessel to provide said disodium salt with an amount of water remaining after one or more drying steps of less than about 20 ppm.