Claims
- 1. A method for simultaneously preparing highly pure bisphenol F and a high molecular weight novolak phenol resin comprising the steps of:
- (1) a preparation step comprising reacting phenol with formaldehyde in the presence of an acid catalyst and removing the acid catalyst, water and the unreacted phenol from the resulting reaction product to give a crude bisphenol F;
- (2) a distillation step comprising continuously distilling a part of the crude bisphenol F in a still maintained at a pressure ranging from 1 to 5 mm Hg, while continuously withdrawing a still bottom product to give a highly pure bisphenol F, as a distillate, having a binuclear moiety-content of not less than 95% by weight and a novolak phenol resin, as a still-bottom product, having a binuclear moiety-content of not more than 15% by area; and
- (3) a step for polymerizing the novolak phenol resin with formaldehyde in the presence of an acid catalyst to give a high molecular weight novolak phenol resin.
- 2. The method for simultaneous preparation as set forth in claim 1 wherein phenol and formaldehyde are reacted at a molar ratio (P/F) ranging from 6 to 30.
- 3. The method for simultaneous preparation as set forth in claim 1 wherein, in the distillation step, the crude bisphenol F is continuously distilled in a still maintained at a pressure ranging from 1 to 5 mm Hg and a temperature ranging from 220.degree. to 250.degree. C., while continuously supplying the crude bisphenol F to the still, condensing a part of gases generated in the still in a partial condenser, returning the condensate to the still and continuously withdrawing the still-bottom product.
- 4. The method for simultaneous preparation as set forth in claim 1 wherein, in the distillation step, a distillation apparatus comprising a plurality of stills maintained at a pressure ranging from 1 to 5 mm Hg and a temperature ranging from 200.degree. to 250.degree. C. is provided and the crude bisphenol F is continuously distilled, while the crude bisphenol F is continuously supplied to a first still of the apparatus, the still-bottom product from each still is continuously supplied to each subsequent still; at least a part of evaporated gases discharged from a final still maintained at a temperature ranging from 220.degree. to 250.degree. C. and a pressure ranging from 1 to 5 mm Hg is condensed to return the condensate to the final still and the still-bottom product from the final still is continuously withdrawn.
- 5. The method for simultaneous preparation as set forth in claim 3 wherein the partial condenser is a multi-tubular cylindrical heat exchanger or a coil heat exchanger.
- 6. The method for simultaneous preparation as set forth in claim 3 wherein the partial condensation ratio (weight ratio) ranges from 0.05 to 0.5.
- 7. The method for simultaneous preparation as set forth in claim 3 wherein the binuclear moiety-content of the distillate is not less than 98% by weight.
- 8. The method for simultaneous preparation as set forth in claim 3 wherein the binuclear moiety-content of the still-bottom product is not more than 10% by area.
- 9. The method for simultaneous preparation as set forth in claim 4 wherein the partial condenser is a multi-tubular cylindrical heat exchanger or a coil heat exchanger.
- 10. The method for simultaneous preparation as set forth in claim 4 wherein the partial condensation ratio (weight ratio) ranges from 0.05 to 0.5.
- 11. The method for simultaneous preparation as set forth in claim 4 wherein the binuclear moiety-content of the distillate is not less than 98% by weight.
- 12. The method for simultaneous preparation as set forth in claim 4 wherein the binuclear moiety-content of the still-bottom product is not more than 10% by area.
- 13. A method for simultaneously preparing a bisphenol F for general use and a high molecular weight novolak phenol resin comprising the steps of:
- (1) a preparation step comprising reacting phenol with formaldehyde in the presence of an acid catalyst and removing the acid catalyst, water and the unreacted phenol from the resulting reaction product to give a crude bisphenol F;
- (2) a distillation step comprising continuously distilling a part of the crude bisphenol F in a still maintained at a pressure ranging from 1 to 5 mm Hg, while continuously withdrawing a still bottom product to give a highly pure bisphenol F, as a distillate, having a binuclear moiety-content of not less than 95% by weight and a novolak phenol resin, as a still-bottom product, having a binuclear moiety-content of not more than 15% by area;
- (3) a step for mixing the highly pure bisphenol F with the remaining crude bisphenol F to give a bisphenol F for general use; and
- (4) a step for polymerizing the novolak phenol resin with formaldehyde in the presence of an acid catalyst to give a high molecular weight novolak phenol resin.
- 14. The method for simultaneous preparation as set forth in claim 13 wherein phenol and formaldehyde are reacted at a molar ratio (P/F) ranging from 6 to 30.
- 15. The method for simultaneous preparation as set forth in claim 13 wherein, in the distillation step, the crude bisphenol F is continuously distilled in a still maintained at a pressure ranging from 1 to 5 mm Hg and a temperature ranging from 220.degree. to 250.degree. C., while continuously supplying the crude bisphenol F to the still, condensing a part of gases generated in the still in a partial condenser, returning the condensate to the still and continuously withdrawing the still-bottom product.
- 16. The method for simultaneous preparation as set forth in claim 13 wherein, in the distillation step, a distillation apparatus comprising a plurality of stills maintained at a pressure ranging from 1 to 5 mm Hg and a temperature ranging from 200.degree. to 250.degree. C. is provided and the crude bisphenol F is continuously distilled, while the crude bisphenol F is continuously supplied to a first still of the apparatus, the still-bottom product from each still is continuously supplied to each subsequent still; at least a part of evaporated gases discharged from a final still maintained at a temperature ranging from 220.degree. to 250.degree. C. and a pressure ranging from 1 to 5 mm Hg is condensed to return the condensate to the final still and the still-bottom product from the final still is continuously withdrawn.
- 17. The method for simultaneous preparation as set forth in claim 15 wherein the partial condenser is a multi-tubular cylindrical heat exchanger or a coil heat exchanger.
- 18. The method for simultaneous preparation as set forth in claim 15 wherein the partial condensation ratio (weight ratio) ranges from 0.05 to 0.5.
- 19. The method for simultaneous preparation as set forth in claim 15 wherein the binuclear moiety-content of the distillate is not less than 98% by weight.
- 20. The method for simultaneous preparation as set forth in claim 15 wherein the binuclear moiety-content of the still-bottom product is not more than 10% by area.
- 21. The method for simultaneous preparation as set forth in claim 16 wherein the partial condenser is a multi-tubular cylindrical heat exchanger or a coil heat exchanger.
- 22. The method for simultaneous preparation as set forth in claim 16 wherein the partial condensation ratio (weight ratio) ranges from 0.05 to 0.5.
- 23. The method for simultaneous preparation as set forth in claim 16 wherein the binuclear moiety-content of the distillate is not less than 98% by weight.
- 24. The method for simultaneous preparation as set forth in claim 16 wherein the binuclear moiety-content of the still-bottom product is not more than 10% by area.
CROSS-REFERENCES TO RELATED APPLICATION
This is a continuation-in-part application of U.S. patent application Ser. No. 08/021,577, filed on Feb. 24, 1993.
US Referenced Citations (1)
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Date |
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4937392 |
Imanari et al. |
May 1990 |
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Non-Patent Literature Citations (1)
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Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
21577 |
Feb 1993 |
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