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
06673974
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) in high yield and in high selectivity by an acid condensation reaction of phenol with 3,3,5-trimethylcyclohexanone (referred to as “TMC” hereinafter) in a stable manner.
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. 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 as residue.
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.
As mentioned hereinbefore, BPTMC is used as raw materials for polycarbonate resins for optical use. In order to supply BPTMC to this use, it is more and more strongly demanded to produce high purity BPTMC which is free of by-products derived from the reaction, 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.
It is essentially important to increase the selectivity and yield of the reaction to produce the desired high purity and high quality product in a stable manner. However, according to the known processes for production of BPTMC by the condensation reaction of phenol with TMC in the presence of an acid catalyst, the selectivity of reaction is so small as about 70% so long as the present inventors know.
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 suitable for industrial production of BPTMC in high selectivity and in high yield in a stable 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 wherein the reaction of phenol with 3,3,5-trimethylcyclohexanone is started in a slurry comprising phenol adduct crystals of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane and hydrated phenol in the presence of an acid catalyst, and then the reaction is continued in the slurry.
BEST MODE FOR CARRYING OUT THE INVENTION
According to the process of the invention for production of 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, the reaction of phenol with TMC is started and carried out using an acid catalyst in the presence of hydrated phenol which contains phenol adduct crystals of BPTMC, so that the BPTMC generated in the reaction forms adduct crystals with phenol immediately in the reaction mixture. Thus, the reaction is carried out in a slurry from the start to the completion of the reaction.
In order to start and continue the reaction of phenol with TMC in the presence of an acid catalyst in a slurry which contains phenol adduct crystals of BPTMC as mentioned above, it is preferred that, for example, phenol and water are placed in a reaction vessel before the reaction is started and, while the mixture of phenol and water (i.e., hydrated phenol), which is often referred to the starting liquid mixture, is maintained at a temperature in the range of 15° C. to 40° C. at which phenol adduct crystals of BPTMC do not decompose nor are soluble in the starting liquid mixture, phenol adduct crystals of BPTMC are added to the starting liquid mixture so that phenol adduct crystals of BPTMC are already present in the starting liquid mixture before the start of the reaction. Subsequently an acid catalyst is introduced into the reaction vessel and then a mixture of TMC and phenol to start the reaction while the reaction mixture is maintained at the temperature in the range above mentioned throughout the reaction.
The amount of BPTMC present in the starting liquid mixture before the start of the reaction depends on the temperature of the starting liquid mixture, but it is usually not less than 3% by weight, preferably in the range of 5-15% by weight of the phenol in the starting liquid mixture so that BPTMC readily forms phenol adduct crystals therein.
When phenol is reacted with TMC in the presence of water using an acid catalyst according to the known processes, the generated BPTMC is dissolved in phenol since the reaction mixture contains excess phenol. Accordingly, no adduct crystals are formed throughout the reaction depending on the amount of phenol in the reaction mixture or the temperature of the reaction mixture, or no adduct crystals are formed until the generated BPTMC exceeds its saturation solubility in phenol at the reaction temperature, that is, usually for several hours after the reaction has been started.
In contrast, according to the invention, the reaction of phenol with TMC is started and continued using an acid catalyst in the presence of hydrated phenol which contains phenol adduct crystals of BPTMC. Accordingly, BPTMC generated in the reaction forms adduct crystals with phenol immediately in the reaction mixture so that the reaction is carried out in a slurry from the start of the reaction.
In this manner, the starting liquid mixture is a slurry which contains phenol adduct crystals of BPTMC, and the reaction is started in the slurry according to the invention. Consequently, BPTMC generated by the reaction of phenol with TMC forms phenol adduct crystals immediately in the reaction mixture from the start of the reaction. Thus, BPTMC generated by the reaction of phenol with TMC is excluded as phenol adduct crystals or a solid phase from the liquid phase of the reaction mixture which contains phenol, TMC and water from the start of the reaction. Accordingly, undesired side reactions are suppressed, but also the desired reaction is promoted, and as a result, the selectivity and yield of the reaction improves.
The ratio of phenol (A) and TMC (B) both used as raw materials is in the range of 4 to 9, preferably in the range of 6 to 8, in terms of A/B molar ratio. In addition, aromatic hydrocarbons such as toluene, xylene or mesitylene may be used together with phenol in an amount of 10% by weight or less based on the reaction mixture.
According to the invention, water is used together with phenol usually in an amount o
Ekawa Kenji
Isota Yoichiro
Nakaguchi Toru
Yao Kazuhiko
Honshu Chemical Industry Co. Ltd.
Shippen Michael L.
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