Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Reexamination Certificate
2003-03-06
2004-01-06
Shippen, Michael L. (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
Reexamination Certificate
active
06673973
ABSTRACT:
TECHNICAL FIELD
The invention relates to a process for production of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (referred to as “BPTMC” hereinafter). More particularly, the invention relates to a process for production of BPTMC by an acid condensation reaction of phenol with 3,3,5-trimethylcyclohexanone (referred to as “TMC” hereinafter) wherein the filtrate which is obtained in the crystallization and filtration step for the resulting reaction product is heated as it is thereby not only to reduce the amount of residue (industrial wastes) generated in the reaction which cannot be recovered for reuse but also to recover phenol efficiently.
BACKGROUND ART
In recent years, BPTMC is used as raw materials for the production of optical products such as optical disks, as well as synthetic resins for optical use such as polycarbonate resins for optical use. In order to supply BPTMC to this use, it is demanded to produce uncolored high purity BPTMC which is free of by-products, and besides free of high boiling point by-products or colored by-products derived from purification processes for the obtained reaction product and residual phenol or trace impurities such as sodium in high selectivity and in high yield in an industrially stable manner.
A variety of processes for the production of BPTMC are already known. According to one of such processes, phenol is reacted with TMC using hydrogen chloride gas as a catalyst and an alkyl mercaptan as a promoter in the presence of an inactive organic solvent or in the absence of a solvent and then phenol remained unreacted is removed from the reaction mixture by steam distillation, as described in Japanese Patent Application Laid-open No. 2-88634. It is also described therein that, after the reaction, water is added to the reaction mixture, and then an alkali to neutralize the reaction mixture, followed by heating, cooling and removing an aqueous phase, thereby obtaining the desired BPTMC.
A further process is known, as is described in Japanese Patent Application Laid-open No. 8-505644. According to the process, phenol is reacted with TMC using hydrogen chloride gas as a catalyst and an alkyl mercaptan such as octanethiol as a promoter. After the reaction, water is added to the reaction mixture to form a slurry, and the slurry is filtered to provide 1:1 adduct crystals of BPTMC and phenol, and then the phenol is removed from the adduct crystals, thereby providing the desired BPTMC.
A process is also known, as described in Japanese Patent Application Laid-open No. 4-282334. The process provides the desired BPTMC by the reaction of phenol with TMC using water-insoluble cation exchange resins having sulfonic acid groups therein as a catalyst and a mercaptan compound as a promoter. In Japanese Patent Application Laid-open No. 5-213803, there is described a process in which an acid catalyst such as benzenesulfonic acid is added to a mixture of phenol, TMC, a mercaptan compound as a promoter and water, whereupon the reaction is started with stirring, and the desired BPTMC is obtained in high selectivity.
However, according to the known processes, phenol is used usually in a large excess relative to TMC so that it is important how to recover unreacted phenol efficiently and how to recycle to the reaction. In particular, the filtrate which is obtained by crystallizing and collecting the desired reaction product after the completion of the reaction contains phenol, BPTMC dissolved in the phenol, and reaction by-products such as isomers, it is very important to treat the filtrate efficiently to recover phenol in an economical manner, but also to reduce the amount of the resulting residue (industrial wastes) as much as possible in order to produce BPTMC advantageously in an industrial scale.
On the other hand, in respect of 2,2-bis(4-hydroxy-phenyl)propane (referred to as “bisphenol A” hereunder), a process for production including reuse of filtrate from a crystallization stage after the completion of the reaction is proposed. For example, Japanese Patent Application Laid-open No. 5-345737 describes a process as follows. Phenol adduct crystals of bisphenol A are crystallized out of a phenol solution containing bisphenol A, the crystals are collected by filtration, the resulting mother liquor is subjected to distillation to recover the phenol and the thus recovered phenol is recycled to the reaction stage. The bottom liquid in a distilling tower is heated and decomposed in the presence of an alkali catalyst. The resulting substance is recovered under a reduced pressure and purified by using an ion exchange resin, followed by recycling to the reaction.
In Japanese Patent Application Laid-open No. 6-321834, it is described that after phenol adduct crystals of bisphenol are crystallized and separated out of the reaction mixture, the resulting mother liquor is made contact with an acid catalyst to isomerize o- and p-isomers to p- and p′-isomers, and then the resulting isomers are recycled back to the crystallization stage for reuse.
Further in Japanese Patent Application Laid-open No. 10-59888, the following is described. Phenol is reacted with acetone in the presence of an ion exchange resin catalyst to produce bisphenol A, and the bisphenol A produced is led to a phenol removal unit to separate unreacted phenol therefrom. The obtained bisphenol A is led to a melt crystallizer to separate residual phenol and isomers therefrom. The separated phenol and isomers are cracked, and the thus recovered phenol is recycled back to the reaction stage for reuse.
However, it is difficult to predict the behavior of formation of BPTMC by a condensation reaction of TMC which is an alicyclic ketone having three methyl groups in the molecule with phenol based on the behavior of production of bisphenol A by a condensation reaction of acetone and phenol. As a matter of fact, nothing has been known how to treat a filtrate efficiently which is obtained from the steps of crystallizing and filtering the reaction products and contains phenol and BPTMC dissolved in the phenol and how to treat the resulting filtrate to reduce the amount of the resulting residue (industrial wastes) as much as possible while how to recover the phenol efficiently so that BPTMC can be produced advantageously in an industrial manner.
The invention has been accomplished to solve such problems as involved in the known processes for the production of BPTMC by an acid condensation reaction of phenol and TMC.
Therefore, it is an object of the invention to provide a process for production of BPTMC advantageously in an industrial manner in which phenol adduct crystals of BPTMC are crystallized and separated from the reaction mixture and the resulting filtrate is treated effectively to reduce the amount of residue (industrial wastes) which can not be recovered for reuse, but also to recover phenol efficiently so that BPTMC is produced advantageously in an industrial manner.
SUMMARY OF THE INVENTION
The invention provides a process for production of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane which comprises reacting phenol with 3,3,5-trimethylcyclohexanone in the presence of an acid catalyst, adding an aqueous solution of alkali to the resulting reaction mixture to neutralize it, removing a water phase from the thus neutralized reaction mixture, cooling the resulting oil phase to crystallize phenol adduct crystals of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane while obtaining a primary filtrate, wherein the primary filtrate is heated to a temperature. of 150-250° C. in the presence of an alkali catalyst in an inert gas atmosphere under a reduced pressure to thermally decompose the 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane contained in the primary filtrate.
BEST MODE FOR CARRYING OUT THE INVENTION
According to the invention, phenol is reacted with TMC in the presence of an acid catalyst (reaction step), an alkali solution is added to the resulting reaction mixture to neutralize it (neutralization step), the resulting phenol adduct crystals of BPTMC are dissolved in the thus ne
Ekawa Kenji
Isota Yoichiro
Nakaguchi Toru
Yao Kazuhiko
Honshu Chemical Industry Co. Ltd.
Shippen Michael L.
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