JP5668562B2 - Method for producing bisphenol A - Google Patents

Description

  The present invention relates to a liquid containing a strongly acidic ion exchange resin in which a strong acid group is introduced into gel-type beads obtained by copolymerization of a polymerizable monomer containing a styrene monomer and a crosslinkable monomer, and bis (hydroxyphenyl) propanes. Is a method for producing bisphenol A, which includes a step of isomerizing to bisphenol A.

Bisphenol A (2,2-di (4-hydroxyphenyl) propane, hereinafter "4,4 '
Is sometimes important as a raw material for epoxy resins and polycarbonate resins, and demand is increasing in recent years. In order to obtain a high-quality resin at a lower cost, a method for more efficiently producing colorless and high-purity bisphenol A is required.
Usually, bisphenol A is continuously produced by subjecting a stoichiometric excess of phenol and acetone to a condensation reaction in the presence of an acid catalyst such as an ion exchange resin. Then, bisphenol A is contained in the adduct after being recovered as an adduct of bisphenol A and phenol (hereinafter sometimes abbreviated as “adduct”) by cooling the concentrated liquid of the condensation reaction product. It is obtained as a product by removing phenol. Then, the mother liquor from which the adduct has been separated after crystallization is circulated in the reaction step, crystallization step, etc., and reused in the process.

In addition to bisphenol A, the mother liquor obtained when crystallization of the adduct of bisphenol A and phenol includes 2- (2-hydroxyphenyl) -2- (4-hydroxyphenyl) propane (hereinafter, “2, Bis (hydroxyphenyl) propanes that can be isomerized to bisphenol A, including the “4 ′ form” (sometimes abbreviated as “4 ′ form”). It is important to recover the isomerizable component by isomerization to bisphenol A. In this isomerization step, an ion exchange resin into which a strong acid group such as sulfonic acid is introduced is usually used as a catalyst (hereinafter sometimes referred to as “isomerization catalyst”), but this catalyst has a high deterioration rate. However, there has been a problem in that the frequency of catalyst replacement is increased.

As a technique for suppressing deterioration of the isomerization catalyst, a method of extending the life of the isomerization catalyst by controlling the water concentration of the mother liquor or the like brought into contact with the isomerization catalyst is disclosed (see Patent Document 1). . However, when water is added, it is necessary to remove water in a later process, and energy for the removal process is required. Moreover, since the reactivity is lowered by adding water, there is a problem that the amount of catalyst needs to be increased in order to maintain the reaction rate.
That is, depending on the above method, the life of the isomerization catalyst is not sufficiently extended, and it is necessary to perform a special treatment. Therefore, the deterioration of the isomerization catalyst is more easily suppressed, and bisphenol A is advantageously industrially advantageous. There was a need for a method of producing

JP 2007-217301 A

The present invention provides an acid catalyst that is used in an isomerization reaction in a method for producing bisphenol A having an isomerization reaction step and that is moderately deteriorated. Furthermore, by using the acid catalyst, bisphenol A is provided. It is an object of the present invention to provide a method for efficiently manufacturing a product.

In order to solve the above problems, the present inventors have provided a strongly acidic ion exchange resin in which a strong acid group is introduced into a gel-type bead obtained by a copolymerization reaction of a polymerizable monomer containing a styrene monomer and a crosslinking monomer. When isomerizing to bisphenol A by bringing it into contact with a liquid containing bis (hydroxyphenyl) propanes, the catalytic activity is maintained high when the average particle size of the strongly acidic ion exchange resin is 650 μm or less. And found that its deterioration is moderate.

The present invention has been completed based on these findings.
That is, the present invention
[1] A liquid containing a strongly acidic ion exchange resin in which a strong acid group is introduced into gel-type beads obtained by copolymerization of a polymerizable monomer containing a styrene monomer and a crosslinkable monomer, and bis (hydroxyphenyl) propanes; In the process for producing bisphenol A, which includes an isomerization step of isomerizing to bisphenol A by bringing the strong acidic ion exchange resin into an average particle size of 650 μm.
m or less, a method for producing bisphenol A,
[2] The method for producing bisphenol A according to the above [1], wherein the strongly acidic ion exchange resin has a crosslinking degree of 2 to 6%.
[3] In the method for manufacturing bisphenol A consisting of the following from (A) (G) step, following
The average particle size of the strongly acidic ion exchange resin used in the step (F) is 650 μm or less;
(A) a condensation reaction step in which an excess amount of phenol and acetone is subjected to a condensation reaction in the presence of an acidic catalyst;
(B) a concentration step for concentrating the reaction mixture obtained in the condensation reaction step;
(C) a crystallization / solid-liquid separation step for crystallizing an adduct of bisphenol A and phenol by cooling the concentrate obtained in the concentration step and separating the adduct into a mother liquor,
(D) a phenol removal step of removing phenol from an adduct of bisphenol A and phenol and recovering bisphenol A; and
(E) having a granulation step of granulating bisphenol A obtained in the phenol removal step;
(F) an isomerization step in which at least a part of the mother liquor obtained in the crystallization / solid-liquid separation step is brought into contact with a strongly acidic ion exchange resin to isomerize to bisphenol A;
(G) a bisphenol recovery step for separating and recovering bisphenol A from the isomerization treatment liquid obtained in the isomerization step,
[4] The method for producing bisphenol A according to the above [3], wherein the strongly acidic ion exchange resin has a particle size of 30 to 650 μm is 50% or more of the whole.

The present invention provides an acid catalyst for use in an isomerization reaction in a method for producing bisphenol A having an isomerization reaction step, which is moderately deteriorated. Furthermore, by using the acid catalyst, the catalyst life is extended, and particularly in terms of cost, bisphenol A
It has the effect that the method of manufacturing industrially advantageous is provided.

It is a figure which shows the superposition | polymerization apparatus used for the manufacturing method of a gel type bead. It is a figure which shows the nozzle member installed in a droplet manufacturing apparatus. It is a figure which shows the relationship between the average particle diameter and uniformity coefficient of an isomerization reaction catalyst, and a catalyst lifetime. It is a figure which shows the relationship between the gel type | mold and macroporous type | mold of an isomerization reaction catalyst, and catalyst lifetime.

The present invention relates to a liquid containing a strongly acidic ion exchange resin in which a strong acid group is introduced into gel-type beads obtained by copolymerization of a polymerizable monomer containing a styrene monomer and a crosslinkable monomer, and bis (hydroxyphenyl) propanes. In the process for isomerizing to bisphenol A (isomerization process), wherein the average particle size of the strongly acidic ion exchange resin is 650 μm or less. Is the method.

The method for producing bisphenol A is a known method except for the isomerization catalyst used in the isomerization step. Specifically, an excess amount of phenol and acetone are subjected to a condensation reaction in the presence of a strongly acidic ion exchange resin catalyst (hereinafter referred to as “condensation reaction step”), and the resulting bisphenol A, unreacted phenol, water After concentrating the reaction mixture containing the above (hereinafter referred to as “concentration step”), the adduct of bisphenol A and phenol is crystallized by cooling, and the adduct is separated from the mother liquor (hereinafter referred to as “crystal”). And then removing phenol from the adduct (hereinafter referred to as “phenol removal step”) and recovering bisphenol A to produce bisphenol A, and at least one of the above mother liquors. After the part is brought into contact with a strongly acidic ion exchange resin and subjected to an isomerization treatment, bisphenol A is recovered (hereinafter referred to as “isomerization step”). The detail of the said process is as follows.

(A) Condensation reaction step The raw material phenol and acetone are reacted in a stoichiometric excess of phenol. The molar ratio of phenol to acetone is in the range of phenol / acetone = 3-30, preferably 5-20. The reaction temperature is usually 50 to 100 ° C. As the catalyst, a strongly acidic cation exchange resin such as a sulfonic acid type is used.

Although the manufacturing method of the said phenol includes the well-known method used normally, the phenol collect | recovered within the bisphenol manufacturing process explained in full detail behind can also be used.
The above-mentioned phenol (excluding the phenol recovered in the bisphenol production process described later) can be used as it is as long as it has a high purity, but generally it is preferably used after purification. The method for purifying phenol is not particularly limited. For example, phenol is reacted at 40 to 110 ° C. with an acidic catalyst such as a general cation exchanger having a strong acid group to remove impurities contained in phenol. For example, a method of removing the heavy component by distilling after making it heavy can be mentioned. The same acidic catalyst as the isomerization catalyst described below can be used. Usually, the purified phenol is used as it is, but when the moisture is contained in the phenol, it is generally preferable to use it after removing the moisture. Although there is no restriction | limiting in particular as a method of removing the water | moisture content in phenol, For example, the method of distilling the phenol containing a water | moisture content in presence of an azeotropic agent, and isolate | separating a phenol and a water | moisture content etc. is mentioned. The phenol thus obtained is used as a reaction raw material by supplying it to the reactor. The main form of the cation exchanger having a strong acid group is preferably a gel type. In addition, a porous type (a porous type, a high porous type, or a macroporous type) is also preferable from the viewpoint of ensuring substance diffusibility, resin durability, and strength. The gel type includes a simple gel type copolymer and an expanded network type gel copolymer, both of which can be used. On the other hand, the porous type is a porous copolymer, which can be used with any surface area, porosity, average pore diameter and the like.

As a method for preparing a cation exchanger having a gel-type or porous-type strong acid group, a conventionally known method can be used. For example, “Technology and Application of Ion Exchange Resin” (issued by Organo Corporation, revised edition, Showa) (May 16, 1981, pages 13-21).
The size of the strongly acidic ion exchanger (hereinafter sometimes referred to as “catalyst beads”) and the modified strong acid type cation exchanger described below is such that the average particle size is usually 0.2 mm or more and 2.0 mm or less. The uniformity of the particle size distribution is usually 1.6 or less, preferably 1.5 or less. Further, as particularly preferred catalyst beads, catalyst beads having an average particle size of 30 to 650 μm, or modified strong acid cation exchanger described below are 50% or more of the whole, preferably 60% or more, more preferably 80% or more. Most preferably, it occupies 90% or more.

The catalyst beads may be produced by any method as long as the catalyst beads having the size described above can be produced. The following is a copolymerization reaction of a polymerizable monomer containing a styrene monomer and a crosslinkable monomer. The gel type catalyst beads obtained in the above will be described in detail as an example.
The styrenic monomer that is a raw material for the gel-type catalyst beads is a monomer having an arbitrary substituent in a range that does not impair the function as an ion exchange resin on styrene or a benzene ring of styrene or a vinyl group of styrene, Polymers such as polyesters, polycarbonates, polyamides, polyolefins, poly (meth) acrylic acid esters, polyethers, polystyrenes, and macromonomers in which the ends of oligomers have a styryl structure may also be used. Here, “(meth) acryl” means “acryl” and “methacryl”. The same applies to “(meth) acryloyl” described later. As the styrenic monomer, a monomer represented by the following formula (1) is preferable.

(In the formula, X1, X2, and X3 each represent a hydrogen atom, an alkyl group, an aryl group, an alkoxy group, a halogen atom, an alkylsilyloxy group, a nitro group, or a nitrile group, and Y represents a hydrogen atom or an amino group. , Alkylamino groups, alkyl groups, alkenyl groups, alkynyl groups, halogen atoms, haloalkyl groups, aryl groups such as phenyl groups and naphthyl groups, aralkyl groups such as benzyl groups, alkoxyalkyl groups, nitro groups, alkanoyl groups, benzoyl groups, etc. Aroyl, alkoxycarbonyl, allylalkoxycarbonyl, alkoxy, haloalkoxy, allyloxy, aralkyloxy, alkoxyalkyloxy, alkanoyloxy, alkoxycarbonyloxy, aralkyloxycarbonyloxy, or alkyl N represents an integer of 1 to 5, X1, X2, and X3 may be the same or different from each other, and a plurality of Ys when n is 2 or more may be the same or different. .)
Specific examples of the styrenic monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, fluorostyrene, chlorostyrene, and bromo. A vinyl group such as styrene such as styrene in which a benzene ring is substituted with an alkyl group having 1 to 4 carbon atoms or a halogen atom, α-methylstyrene, α-fluorostyrene, β-fluorostyrene, or the like is used. And styrene substituted with an alkyl group or a halogen atom. Of these, styrene is most preferable as the styrene monomer. Moreover, these styrene-type monomers may be used individually by 1 type, and 2 or more types may be mixed and used for them.

The crosslinkable monomer is a compound having two or more carbon-carbon double bonds copolymerizable with the styrenic monomer in the molecule. Specifically, polyvinylbenzene such as divinylbenzene and trivinylbenzene, divinyltoluene and the like Two or more benzene rings such as alkyldivinylbenzene, bis (vinylphenyl), bis (vinylphenyl) methane, bis (vinylphenyl) ethane, bis (vinylphenyl) propane, bis (4-vinylphenyl) sulfone Or the aromatic divinyl compound which has a structure couple | bonded through coupling groups, such as an alkylene group and a styrylene group, is mentioned. Polymers such as polyester, polycarbonate, polyamide, polyolefin, poly (meth) acrylic acid ester, polyether, polystyrene, etc. Polymeric carbon-carbon double bonds such as styryl structure at both ends of oligomer and (meth) acrylic structure It may be a macromonomer having Among these, divinylbenzene is preferable as the crosslinkable monomer. Depending on the divinylbenzene, ethylvinylbenzene (ethylstyrene) may be produced as a by-product when it is produced, and this divinylbenzene may be used in the present invention. can do. These crosslinkable monomers may be used individually by 1 type, and 2 or more types may be mixed and used for them.

The polymerizable monomer includes the styrenic monomer and the crosslinkable monomer, but may further include other monomers that can be polymerized therewith as necessary. Specific examples of such polymerizable monomers (hereinafter sometimes referred to as “third monomers”) include polycyclic aromatic skeletons such as naphthalene, anthracene, and phenanthrene, such as vinylnaphthalene and vinylanthracene. Vinyl monomers; (meth) acrylic acid esters such as methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate; diene hydrocarbon compounds such as butadiene and isoprene; α-olefins such as 1-pentene and 1-hexene ; (Meth) acrylonitrile and the like. These may be used alone or in combination of two or more.

  In addition, by using such a third monomer, an effect such as an increase in oxidation resistance can be obtained. In this case, the amount used is usually 50 mol% or less with respect to the styrene monomer, preferably It is 20 mol% or less, and particularly preferably 10 mol% or less. If the amount of the third monomer used is too large, the amount of strong acid groups per unit weight that can be introduced into the resulting copolymer decreases, and the desired catalytic activity may not be obtained.

  The degree of crosslinking of the gel-type beads, which are a copolymer obtained by polymerizing a polymerizable monomer containing a styrene monomer and a crosslinking monomer, is preferably 1% or more, more preferably 2% or more, and preferably 8% or less. 6% or less is more preferable. The degree of cross-linking here refers to the concentration of the cross-linkable monomer in the polymerizable monomer to be subjected to polymerization on the weight basis, and is the same as the definition used in this field.

  If the degree of crosslinking is too small, it will be difficult to maintain the strength of the resulting catalyst beads and modified strong acid type cation exchanger, and when used as a catalyst, a mixed solvent of phenol or phenol and water before use. The catalyst beads and modified strong acid cation exchangers are crushed by swelling and shrinking when they are brought into contact with the like, which is not preferable. On the other hand, if the degree of crosslinking is too large, the resulting catalyst beads and modified strong acid type cation exchanger will not easily swell, so that diffusion resistance in the catalyst beads and modified strong acid type cation exchanger will easily occur, and catalytic activity will be increased. This is not preferable because it causes a significant decrease in.

  The copolymerization reaction of a polymerizable monomer containing a styrene monomer and a crosslinkable monomer can be performed based on a known technique using a radical polymerization initiator. As the radical polymerization initiator, one or more of benzoyl peroxide, lauroyl peroxide, t-butyl hydroperoxide, azobisisobutyronitrile and the like are used. Usually, the weight of the polymerizable monomer (total monomer) Weight) to 0.05 wt% or more and 5 wt% or less.

  The polymerization mode is not particularly limited, and can be carried out in various modes such as solution polymerization, emulsion polymerization, suspension polymerization, etc. In order to keep the uniformity coefficient and average particle size described below within a specified range, a sieve is used. It is also possible to classify by. And in this invention, the well-known method of obtaining the spherical copolymer of a uniform particle size is applied suitably. For example, prior to polymerization, a method is known in which an oil-in-water dispersion in which monomer-containing droplets of uniform particle size are dispersed in a separate apparatus is prepared, and this dispersion is charged into a polymerization vessel and polymerized. As a method for producing an oil-in-water dispersion with a uniform particle size, a nozzle plate having an upwardly formed ejection hole is provided at the bottom of a water-filled container, and the monomer-containing liquid is supplied into the water through this ejection hole. By doing so, a method of dispersing the monomer-containing droplets in water (for example, see Japanese Patent Application Laid-Open No. 2003-252908 and Japanese Patent No. 3899786) can be used. This method is employed in the embodiments described later.

  The polymerization temperature in the copolymerization reaction is usually room temperature (about 18 to 25 ° C.) or higher, preferably 40 ° C. or higher, more preferably 70 ° C. or higher, and usually 250 ° C. or lower, preferably 150 ° C. or lower, more preferably. Is 140 ° C. or lower. If the polymerization temperature is too high, depolymerization occurs at the same time, and the degree of polymerization completion is reduced. If the polymerization temperature is too low, the degree of polymerization completion will be insufficient. The polymerization atmosphere can be carried out under air or an inert gas, and nitrogen, carbon dioxide, argon or the like can be used as the inert gas.

  The method for introducing strong acid groups into the gel-type beads, which are copolymers obtained by the above copolymerization reaction, is not particularly limited, and can be performed according to a conventional method. The strong acid group is preferably a sulfonic acid group, and the method of introducing a sulfonic acid group (sulfonation) is, for example, in the absence of an organic solvent, or benzene, toluene, xylene, nitrobenzene, chlorobenzene, tetrachloromethane. In the presence of an organic solvent such as dichloroethane, trichloroethylene or propylene dichloride, the gel-type beads as a copolymer are reacted with a sulfonating agent such as sulfuric acid, chlorosulfonic acid or fuming sulfuric acid. Here, as for an organic solvent and a sulfonating agent, all may be used individually by 1 type, and 2 or more types may be mixed and used for them. The reaction temperature at this time is usually about 0 to 150 ° C., and is appropriately selected according to the sulfonating agent and the organic solvent to be used.

  The exchange capacity (amount of strong acid group) as the cation exchanger having a strong acid group is usually 0.5 meq / mL or more, preferably 1.0 meq / mL or more per unit volume of the resin in the water state. On the other hand, it is usually 3.0 meq / mL or less, preferably 2.0 meq / mL or less. In the case of a dry resin, it is usually 1.0 meq / g or more per unit weight, preferably 2.0 meq / g or more, and usually 6.0 meq / g or less, preferably 5.5 meq / g or less. is there. In the wet state in which the adhering water is removed from the water-containing resin, it is usually 0.5 meq / g or more, preferably 1.0 meq / g or more, while usually 3.0 meq / g or less, preferably 2.0 meq / g. It is as follows. If this exchange capacity is too low, the catalytic activity is insufficient, and a cation exchanger having an excessively high exchange capacity is difficult to produce.

The exchange capacity of the cation exchanger having a strong acid group is, for example, “Diaion, Ion Exchange Resin / Synthetic Adsorbent Manual 1” (Mitsubishi Chemical Corporation, revised 4th edition, issued on October 31, 2007, 133). ˜Page 135) or a method according to this method.
The cation exchanger having a strong acid group is obtained by separating the gel-type beads into which the strong acid group has been introduced by washing, isolation or the like according to a conventional method. When the catalyst is used in a fixed bed flow system, among the catalyst beads contained or the modified strong acid cation exchanger described below, those having a particle size of 30 to 600 μm account for 50% or more. Those are preferably used.

When the catalyst bead or the modified strong acid type cation exchanger described below has a particle size of 30 to 650 μm is 50% or more of the total, excellent performance in terms of catalyst activity and desired bisphenol selectivity can get. On the other hand, when the catalyst beads or the modified strong acid cation exchanger described below has a particle size of 30 to 650 μm is less than 50% of the total, the catalyst activity is lowered due to diffusion resistance in the catalyst particles. At the same time, the sequential reaction within the catalyst particles causes a decrease in selectivity.

  When the average particle diameter of the catalyst beads or the modified strong acid cation exchanger described below is smaller than 100 μm, it is necessary to remarkably increase the supply pressure of the raw material to the catalyst layer, and the force applied to the catalyst particles increases. Since the catalyst particles are easily worn and refined, the life of the catalyst packed bed is shortened. In addition, when the raw material supply pressure is increased, the amount of energy consumption is increased and the economic efficiency of the process is deteriorated. Therefore, the average particle size is preferably 100 μm or more, and the pressure in the catalyst packed bed when used in the fixed bed flow system Since the loss can be suppressed to a low level, the average particle size is more preferably 300 μm or more.

  Further, when the particle size uniformity coefficient of the catalyst beads or the modified strong acid cation exchanger described below is 1.10 or less, the pressure loss in the catalyst packed bed when used in a fixed bed flow system is low. Can be suppressed. Therefore, when using it on a fixed bed, it is preferable that the uniformity coefficient is 1.05 or less because the same effect is further improved. On the other hand, if the uniformity coefficient is greater than 1.10, it is necessary to remarkably increase the supply pressure of the raw material to the catalyst layer, the force applied to the catalyst particles is increased, and the catalyst particles are likely to be worn and refined. The life of the catalyst packed bed is shortened. Further, when the raw material supply pressure is increased, the energy consumption is increased correspondingly, and the economic efficiency of the process is deteriorated.

In addition, the average particle diameter and the grain system distribution uniformity referred to in this specification for the resin are those when the resin is swollen with water before filling, and Diaion Manual 1 (Mitsubishi Chemical Corporation, 4th 2007). Plate, pages 140-142) and is defined by the value calculated by the following formula.
Average particle diameter = diameter uniformity coefficient corresponding to 50% of the cumulative volume of resin = diameter corresponding to the cumulative volume on the large particle side corresponding to 40% / diameter corresponding to the cumulative volume on the large particle side corresponding to 90%. It can also be used as the value of the sieving method by converting the measured value obtained by using a method other than the centrifugal sedimentation method, Coulter method, image analysis method, laser diffraction scattering method and the like.

The condensation reaction of phenol and acetone (hereinafter sometimes referred to as “main reaction step”) is carried out by a continuous bed flow system, a fixed bed flow system, or a suspension batch system. In the case of a fixed bed flow system, the liquid space velocity of the raw material liquid supplied to the reactor is 0.2 to 50 hr ⁻¹ . When the suspension batch method is used, the amount of the resin catalyst is generally in the range of 20 to 100% by weight with respect to the raw material liquid, although it varies depending on the reaction temperature and reaction pressure, and the treatment time is 0.5. About 5 hours.
(B) Concentration step In this step, a crystallization raw material containing bisphenol A concentrated by separating a low boiling point component from the reaction mixture obtained in the condensation reaction step is prepared. As used herein, the low-boiling component is a component having a lower boiling point than phenol. For example, a non-supported promoter such as unreacted acetone, by-product water, alcohol contained as an impurity, isopropylphenol, alkylthiol, etc. Examples include promoters when used. Examples of the method for separating low-boiling components include a method in which a distillation tower is used, the reaction mixture obtained in the reaction step is distilled, and the low-boiling components are separated from the top of the column. The bottom liquid is a liquid component containing bisphenol A and phenol. One or a plurality of known distillation towers can be used, but it is preferable to perform the separation with one group.

When distillation is carried out, it is carried out below the boiling point of phenol, preferably by distillation under reduced pressure. The vacuum distillation is usually performed at a temperature of 50 to 150 ° C. and a pressure of 5 to 40 kPa. A part of the unreacted phenol contained in the reaction mixture may be extracted from the top of the column together with the low-boiling components. Further, if desired, an additional distillation column may be used to remove phenol, or the concentration of bisphenol A may be adjusted by adding phenol. The crystallization raw material obtained by these treatments is supplied to the next crystallization process.

(C) Crystallization-solid-liquid separation process In this process, after forming the slurry containing an adduct from the crystallization raw material obtained at said process, it isolate | separates into an adduct and mother liquid. As the crystallizer, a continuous crystallizer is usually used. As the continuous crystallizer, there are known cooling type crystallizers using jackets and internal coils, external circulation cooling type crystallizers, evaporative cooling type crystallizers, etc., but there is no particular limitation, but external circulation cooling type A crystallizer and a jacket type crystallizer are preferably used. The external circulation cooling type crystallizer is formed by a circulation path composed of piping, valves, etc., between the crystallization tank and a cooler arranged outside thereof, and a multi-tube type cooler is suitable as the cooler. used. Moreover, it is preferable to provide the dissolution tank or heater for melt | dissolving a microcrystal. The jacket-type crystallizer is a type that has a jacket around a container for crystallization, passes a refrigerant through the jacket, and cools it through the wall surface of the container. A container equipped with a stirring blade or baffle in the container and capable of satisfactorily stirring the internal liquid is preferable. Moreover, it is preferable that any type has a draft tube inside for the improvement of a mixing property. In order to control the shape and size of the crystal, a classification device may be provided in the device or provided outside. Examples of the classifier include those using the difference in the sedimentation rate of the crystal depending on the shape and size of the crystal, and those utilizing the difference in the dissolution rate. If necessary, heating can be performed during the crystallization operation, or a crystal dissolution operation can be performed. In such a case, a heat medium is used instead of the refrigerant.

Examples of the solid-liquid separator include a horizontal belt filter, a rotary vacuum filter, a rotary pressure filter, a centrifugal filter separator, a centrifugal sedimentation separator, and a hybrid centrifugal separator (screen ball decanter).
(D) Phenol removal step In this step, phenol is separated from the adduct obtained in the above step to recover bisphenol A. In this phenol removal step (D), the adduct is usually heated and melted at 100 to 160 ° C., and the obtained melt is used, for example, by using a distillation apparatus, a thin film evaporator, a flash evaporator or the like. A method of removing a portion of phenol is employed. In addition, a method of purifying bisphenol A after removing the residual phenol by steam stripping or the like after the above operation is performed to remove a trace amount of phenol remaining in the melt. . This method is described in, for example, JP-A-63-132850 and JP-A-2-28126.

(E) Bisphenol A granulation step The high-purity, molten bisphenol A obtained as described above is sent to a granulation tower or a flaker, and becomes a solid prill or flake to become product bisphenol A. For example, when a granulation tower is used, molten bisphenol A is fed to the top of the granulation tower and sprayed from a number of holes provided in a nozzle plate installed at the top of the tower. The sprayed melt is cooled by a circulating gas rising from the bottom of the granulation tower, and is extracted from the bottom as a particulate solid called prill, and becomes product bisphenol A. Moreover, the obtained bisphenol A can be transferred to the next step in a molten state without being solid, as in the case where it is used for producing a polycarbonate resin by a melting method.

(F) Isomerization step In this step, a part of the mother liquor separated and divided in the crystallization-solid-liquid separation step (C) is brought into contact with the isomerization catalyst. Here, isomerization means that the 2,4 'isomer in the mother liquor is bisphenol.
Means conversion to A (4,4 'form). The ratio of the mother liquor supplied to the isomerization step is the amount of acid and impurities (substances excluding water, acetone, phenol, bisphenol A) contained in the mother liquor separated in the crystallization-solid-liquid separation step (C). Is preferably determined by:
The total amount of acid and impurities contained in the mother liquor is usually in the range of 0.3 to 2 times by weight, preferably 0.3 to 1.5 times by weight as the concentration with respect to bisphenol A.

In the isomerization step, the mother liquor and the acid catalyst are brought into contact. Prior to this, it is preferable to reduce the concentration of water in the mother liquor to 1% by weight or less. A single-stage or multi-stage flash evaporator or a distillation column is preferably used for the process of reducing the moisture in the mother liquor. When the mother liquor is concentrated due to the accompanying evaporation of water, the concentration of bisphenol A in the mother liquor after dehydration is usually 15% by weight, preferably by adjusting the treatment conditions and adding phenol. It should not exceed 14% by weight. This is to prevent the adduct of bisphenol A and phenol from precipitating in the acid catalyst reactor used in the isomerization step.

The reaction temperature during isomerization is usually 50 ° C. to 90 ° C., and the liquid space velocity is usually 0.1 to 50 hr ⁻¹ . The optimum steady state is a state in which the reaction proceeds about 80 to 100% from the composition of the mother liquor with respect to the chemical equilibrium ratio between the 2,4 ′ form and the 4,4 ′ form (bisphenol A). When the reaction proceeds further, a large amount of a cyclic dimer of isopropenylphenol is produced, and the reaction yield to bisphenol A is extremely deteriorated. The reaction rate is preferably adjusted mainly at the reaction temperature and is preferable in terms of operation, but can also be adjusted by the liquid flow rate, the amount of acid catalyst, and the like.

  The catalyst used for the isomerization treatment is a strongly acidic ion exchange resin in which a strong acid group is introduced into a gel-type bead obtained by a copolymerization reaction of a polymerizable monomer containing a styrene monomer and a crosslinkable monomer, The average particle size is 650 μm or less, preferably 550 μm or less, and the lower limit is preferably 300 μm. As the above isomerization catalyst, those having an average particle size larger than 650 μm have reduced catalyst activity due to diffusion resistance in the catalyst particles, and also accumulated heavy substances due to sequential reaction in the catalyst particles, thereby reducing the catalyst life. This is not preferable because If the average particle size of the isomerization catalyst is smaller than 300 μm, the supply pressure of the raw material to the catalyst layer needs to be remarkably increased, and the force applied to the catalyst particles increases, and the catalyst particles are likely to be worn and refined. The life of the catalyst packed bed is shortened. Further, when the raw material supply pressure is increased, the energy consumption is increased correspondingly, and the economic efficiency of the process is deteriorated. Therefore, the average particle size is preferably 300 μm or more, and the pressure in the catalyst packed bed when used in a fixed bed flow system. Since the loss can be suppressed to a low level, the average particle size is more preferably 400 μm or more.

Further, when the isomerization catalyst of the present invention is used in the condensation reaction step, particularly, the gel type catalyst beads consisting of gel type catalyst beads and having a particle size of 30 to 650 μm are 50% or more of the total. Preferably, it accounts for 60% or more, more preferably 80% or more, and most preferably 90% or more, so that the high selectivity of bisphenol A in the condensation reaction is maintained.

Here, the average particle diameter is a resin when swollen with water before filling, and is described in Diaion Manual 1 (published by Mitsubishi Chemical Corporation, 4th edition, 2007, pages 140 to 142). It is defined by the value calculated by the following formula.
Average particle diameter = diameter corresponding to 50% of the cumulative volume of the resin The method for producing the isomerization catalyst is the same as that for the catalyst gel described above. However, in the case of the isomerization catalyst, the form is a gel type. It will be necessary.

(G) Bisphenol A recovery step The isomerization treatment liquid recovers bisphenol A contained therein to obtain a product. As a specific method for recovering bisphenol A, for example, a method of circulating the isomerization treatment liquid to any of the condensation reaction step, concentration step, and crystallization / solid-liquid separation step, or isomerization reaction treatment solution Is recovered and crystallized by the method described in JP-A-2009-242316, and then recycled to any one of the condensation reaction step, the concentration step, and the crystallization / solid-liquid separation step. Here, as the strongly acidic ion exchange resin used in the recombination reaction step described in JP-A-2009-242316, the isomerization catalyst of the present invention can also be used.

Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited to the following examples.
In the following, “part” means “part by weight”.
[Example 1]
(1) Preparation of raw material solution for isomerization reaction catalyst evaluation First, according to the method described in JP-A-2005-97568, an excess amount of phenol and acetone are subjected to a condensation reaction in the presence of a strongly acidic cation exchange resin catalyst. Reaction step (A), concentration step (B) for preparing a crystallization raw material containing bisphenol A concentrated by separating low-boiling components and phenol from the obtained reaction mixture, and bisphenol A from the obtained crystallization raw material. A crystallization-solid-liquid separation step (C) in which a slurry containing an adduct with phenol is formed and then separated into an adduct of bisphenol A and phenol and a mother liquor, a part of this mother liquor is supplied to the mother liquor treatment step, The other mother liquor was circulated as part of the raw material for the reaction process, and was collected when the composition of the mother liquor was stabilized. The composition was determined using high performance liquid chromatography. Table 1 shows the results.

(2) Production of copolymer (gel-type beads) Using a droplet production apparatus and a polymerization reaction apparatus with an underwater speaker attached as a vibration apparatus shown in FIG. Hereinafter, it may be referred to as “copolymer”).
The droplet manufacturing apparatus 1 includes a droplet manufacturing tank 3 that holds an aqueous medium 2 that forms a continuous phase, a hydrophobic liquid storage tank 5 that holds a hydrophobic liquid 4 that is immiscible with the aqueous medium 2, and a hydrophobic liquid storage tank. And a hydrophobic liquid supply pipe 6 for supplying the hydrophobic liquid 4 stored in 5 to the droplet production tank 3. In addition, the droplet manufacturing apparatus 1 is in contact with the aqueous medium 2 and includes a nozzle member 7 having an ejection hole 11 for ejecting the hydrophobic liquid 4 supplied from the hydrophobic liquid supply pipe 6, and the inside of the droplet manufacturing tank 3. An underwater speaker (underwater acoustic device) 8 which is a vibration means for mechanically vibrating the aqueous medium 2, an aqueous medium storage tank 9 for storing the aqueous medium 2, and the aqueous medium 2 stored in the aqueous medium storage tank 9. And an aqueous medium supply pipe 10 for supplying the liquid to the droplet production tank 3. Here, reference numeral 12 denotes a hydrophobic liquid ejection storage tank, and reference numerals 13 and 14 denote a supply pump for the hydrophobic liquid and the aqueous medium, respectively.

As the nozzle member 7, as shown in FIG. 2, a circular plate having an outer diameter of 100 mm and 345 ejection holes 11 having a diameter of 0.125 mm arranged in an annular shape was used.
Further, the polymerization reaction device 16 in FIG. 1 is a polymerization in which the droplet 15 in the droplet production tank 3 of the droplet production device 1 is transferred together with the aqueous medium 2 and the polymerization reaction is performed without coalescing and crushing the droplet 15. The aqueous medium 2 can be used without attaching and crushing the droplet 15 from the droplet production tank 3 to the reaction tank 17 and the polymerization reaction tank 17.
And a hydrophobic liquid droplet transfer pipe 18 that is transferred together with the liquid crystal.

  In the droplet manufacturing apparatus 1, the droplet is transferred from the hydrophobic liquid storage tank 5 through the hydrophobic liquid supply pipe 6 to the aqueous medium 2 that is held in the droplet manufacturing tank 3 to form a continuous phase. The hydrophobic liquid 4 can be ejected from the ejection holes 11 provided in the nozzle member 7 to form an ejection flow of the hydrophobic liquid 4. At that time, the aqueous medium 2 side is vibrated by, for example, an underwater speaker 8 to break the jet flow into droplets 15 of a hydrophobic liquid having a uniform particle diameter, and the aqueous medium storage tank 9 A flow of the aqueous medium 2 can be formed in the droplet production tank 3 by supplying the aqueous medium 2 stored in the droplet production tank 3 by the supply pump 14. The droplet 15 of the hydrophobic liquid thus made can be moved.

  That is, a hydrophobic liquid ejection storage tank 12 exists in the lower part inside the droplet production tank 3, and a nozzle having an ejection hole 11 that opens toward the aqueous medium 2 and ejects the hydrophobic liquid 4 in the upper part thereof. A member 7 is attached. For this reason, the hydrophobic liquid 4 supplied by the supply pump 13 from the hydrophobic liquid storage tank 5 through the hydrophobic liquid supply pipe 6 is stored in the liquid discharge storage tank 12, and the ejection holes provided in the nozzle member 7. 11 is ejected straight upward. As shown in FIG. 2, a plurality of ejection holes 11 for the hydrophobic liquid 4 are arranged in the nozzle member 7 at a predetermined interval. The diameter of the ejection hole 11 is set according to a desired droplet size.

Since the droplet production tank 3 is connected to the polymerization reaction tank 17 by a droplet transfer pipe 18, droplet production formed by supplying the aqueous medium 2 from the aqueous medium storage tank 9 into the droplet production tank 3. Due to the flow of the aqueous medium 2 in the tank 3, the hydrophobic liquid droplets 15 produced in the droplet production tank 3 are continuously transferred to the polymerization reaction tank 17 together with the aqueous medium 2 and used for the polymerization reaction. .
In this example, first, as the aqueous medium 2, an aqueous solution containing 0.05% by weight of polyvinyl alcohol was filled from the aqueous medium storage tank 9 into the droplet production tank 3 and the polymerization reaction tank 17. The polyvinyl alcohol aqueous solution was heated to 40 ° C. and held until the polymerization reaction started. On the other hand, 96 parts of styrene containing benzoyl peroxide as a polymerization initiator, 4 parts of a polymerizable monomer mixed liquid consisting of divinylbenzene, and a flow rate of 1 from the ejection hole 11 of the nozzle member 7 from the hydrophobic liquid storage tank 5 as a hydrophobic liquid. It was ejected into the droplet production tank 3 at a rate of .54 mL / min / hole. At that time, vibration of 1400 Hz was applied to the jet stream from the underwater speaker 8 in order to break up the jet stream of the polymerizable monomer mixed liquid into droplets 15 having a uniform particle size. The average particle size of the droplets 15 of the polymerizable monomer mixture obtained at this time was 0.32 mm, and the uniformity coefficient was 1.01. The average particle size and uniformity coefficient of the droplet 15 were calculated by taking an enlarged photograph of the droplet and obtaining the particle size distribution by an image analysis method.

The generated droplets 15 were transferred to the polymerization reaction tank 17 along with the flow of the aqueous medium 2. Next, the mixture is polymerized by heating at 75 ° C. for 8 hours while stirring at a rotation speed that does not coalesce or crush the droplets 15 in the polymerization reaction tank 17 (crosslinking degree 4%). It was.
The obtained copolymer slurry was subjected to solid-liquid separation using a centrifuge, and recovered without containing a polyvinyl alcohol aqueous solution. The obtained copolymer was spherical particles having an average particle diameter of 0.29 mm and a uniformity coefficient of 1.02.

(3) Production of gel-type catalyst beads 180 g of the copolymer obtained in (2) above is placed in a 1 L four-necked flask, 198 g of nitrobenzene is added, and the mixture is heated and stirred at 70 ° C. for 1.5 hours. The polymer was swollen. After cooling, 324 g of nitrobenzene, 360 g of 98% by weight sulfuric acid and 189 g of fuming sulfuric acid were added, the temperature was raised to 70 ° C., heated for 4 hours, then heated to 105 ° C. and held for 3 hours.

After the reaction, a large amount of water was added to dilute and remove the sulfuric acid in the flask, and then demineralized water was added and heated and stirred to distill off nitrobenzene. The obtained resin was washed with demineralized water to obtain gel type catalyst beads (hereinafter sometimes referred to as “strongly acidic cation exchange resin”).
The exchange capacity, average particle size, uniformity coefficient, and catalyst bead content with a particle size of 30 to 650 μm were determined for the strongly acidic cation exchange resin obtained, and the results are shown in Table 2.

The average particle diameter and uniformity coefficient of the catalyst beads are described in “Diaion, Ion Exchange Resin / Synthetic Adsorbent Manual 1” (Mitsubishi Chemical Corporation, 4th revised edition, published on October 31, 2007, pages 140 to 141). From the particle size distribution measured by the sieving method described, it was calculated by the following formula.
Average particle diameter = diameter corresponding to 50% of the cumulative volume of resin Uniformity coefficient = diameter corresponding to the cumulative volume on the large particle side corresponding to 40% / diameter corresponding to the cumulative volume on the large particle side corresponding to 90%. The catalyst bead content of ˜650 μm was calculated from the particle size distribution obtained by the sieving method as in the case of the copolymer.

(4) Evaluation of isomerization reaction catalyst 50 mL of the gel type catalyst beads produced in the above (3) was packed in a glass column with a jacket having an inner diameter of 17.6 mm and a total length of 240 mm. While controlling the jacket temperature at 75 ° C., phenol was passed through the top of the reactor filled with the catalyst at 50 mL / hr for 24 hours to completely replace the water in the catalyst with phenol, and then the mother liquor having the composition shown in Table 1 was added. The reaction was carried out by continuously flowing down the flow from the top of the reactor at 75 mL at 50 mL / hr. Each time after the start of the reaction, the reaction solution was collected, and each composition concentration in the reaction solution was quantified by high performance liquid chromatography and a Karl Fischer moisture meter under the following conditions. The rate at which the 2,4 ′ body / 4,4 ′ body reached the 75 ° C. equilibrium value was calculated as the conversion rate of the 2,4 body using the following equation. The results are shown in FIG. The equilibrium value of the 2,4 ′ body / 4,4 ′ body at 75 ° C. was 0.107.

<Calculation formula for conversion rate of 2,4 bodies>
2,4 conversion = 1-((reaction liquid 2,4 ′ / 4,4 ′ ratio) −0.107) / (raw material 2,4 ′
/ 4, 4 'ratio) -0.107)
<Analysis method>
High-performance liquid chromatography: “LC-10A” manufactured by Shimadzu Corporation
Column: Waters Sun Fire ™ C18 5 μm, 4.6φ × 250 mm Detector: UV 280 nm
Eluent: Solution A 90% acetonitrile aqueous solution, solution B 0.59 mol / L 1 mL of phosphoric acid aqueous solution diluted with 1 L of 0.5% sodium dihydrogen phosphate aqueous solution [Example 2]
To a 3 L four-necked flask equipped with a nitrogen introduction tube and a cooling tube, 2316 mL of demineralized water and 27.5 mL of a 6 wt% aqueous polyvinyl alcohol solution were added, and nitrogen was introduced to remove dissolved oxygen.

  On the other hand, a polymerizable monomer mixed solution containing 306.8 g of styrene, 43% by weight of ethylvinylbenzene, 23.2 g of 57% by weight of divinylbenzene, and 0.43 g of benzoyl peroxide having a water content of 25% by weight was added. Prepared. This polymerizable monomer mixture was put into the flask and stirred at 130 rpm to form a suspension. After stirring at room temperature for 30 minutes, the temperature was raised to 75 ° C. and held at 75 ° C. for 8 hours to carry out a copolymerization reaction. . After the polymerization, the aqueous polyvinyl alcohol solution was removed to obtain a copolymer. The copolymer was treated with water tank to remove small particles.

  Using the above copolymer, a strongly acidic cation exchange resin was produced in the same manner as in Example 1. Similarly, the exchange capacity, average particle size, uniformity coefficient, particle size of the obtained strongly acidic cation exchange resin The content of catalyst beads having a diameter of 30 to 650 μm was determined, and the results are shown in Table 2. The isomerization reaction was performed in the same manner as in Example 1 using the above strongly acidic cation exchange resin, and the results calculated from the analysis by liquid chromatography are shown in FIG.

[Example 3]
In the same manner as in Example 2, a polyvinyl alcohol aqueous solution and a polymerizable monomer mixture were prepared, stirred at 120 rpm to form a suspension, and held at 75 ° C. for 8 hours to carry out a copolymerization reaction. After the polymerization, the aqueous polyvinyl alcohol solution was removed to obtain a copolymer. This copolymer was treated with water tank to remove small particles.

  Using the above copolymer, a strongly acidic cation exchange resin was produced in the same manner as in Example 1. Similarly, the exchange capacity, average particle size, uniformity coefficient, particle size of the obtained strongly acidic cation exchange resin The content of catalyst beads having a diameter of 30 to 650 μm was determined, and the results are shown in Table 2. The isomerization reaction was performed in the same manner as in Example 1 using the above strongly acidic cation exchange resin, and the results calculated from the analysis by liquid chromatography are shown in FIG.

As is apparent from FIG. 3, it was found that when the average particle size of the isomerization reaction catalyst is set to 650 μm or less, the catalyst activity is maintained high and the deterioration thereof is moderated. It was also found that the smaller the particle size, the greater the advantage.
[Comparative Example 1]
As the strongly acidic cation exchange resin, a gel type strongly acidic cation exchange resin (trade name: Diaion (registered trademark) SK104) manufactured by Mitsubishi Chemical Corporation with a degree of crosslinking of 4% was prepared. The exchange capacity, average particle size, uniformity coefficient, and catalyst bead content with a particle size of 30 to 650 μm were determined for this strongly acidic cation exchange resin, and the results are shown in Table 2. The isomerization reaction was performed in the same manner as in Example 1 using the above strongly acidic cation exchange resin, and the results calculated from the analysis by liquid chromatography are shown in FIG.

[Reference Example 1]
7.5 mL of a gel type strongly acidic cation exchange resin (trade name: Diaion (registered trademark) SK104) 4% cross-linked by Mitsubishi Chemical Corporation was packed in a stainless steel column having an inner diameter of 1 cm and a total length of 44 cm. Phenol at 75 ° C was passed through the top of the reactor filled with the catalyst at 26 mL / hr for 24 hours to completely replace the water in the catalyst with phenol, and then the mother liquor having the composition shown in Table 1 was added to 26 mL at 75 ° C. The reaction was conducted by continuously flowing down the flow from the top of the reactor at / hr. Each time after the start of the reaction, the reaction solution was collected, and each composition concentration in the reaction solution was quantified by high performance liquid chromatography and a Karl Fischer moisture meter under the following conditions. The results calculated from the analysis by liquid chromatography are shown in FIG.

[Reference Example 2]
As the strongly acidic cation exchange resin, a macroporous strong acid cation exchange resin (trade name: Diaion (registered trademark) RCP160M) manufactured by Mitsubishi Chemical Corporation was prepared. The exchange capacity, average particle size, uniformity coefficient, and catalyst bead content with a particle size of 30 to 650 μm were determined for this strongly acidic cation exchange resin, and the results are shown in Table 2. The isomerization reaction was performed in the same manner as in Reference Example 1 using the above strongly acidic cation exchange resin, and the results calculated from the analysis by liquid chromatography are shown in FIG.

DESCRIPTION OF SYMBOLS 1 Droplet production apparatus 2 Aqueous medium 3 Droplet production tank 4 Hydrophobic liquid 5 Hydrophobic liquid storage tank 6 Hydrophobic liquid supply pipe 7 Nozzle member 8 Underwater speaker 9 Aqueous medium storage tank 10 Aqueous medium supply pipe 11 Ejection hole 12 Hydrophobic liquid Jet storage tank 13, 14 Supply pump 15 Droplet 16 Polymerization reactor 17 Polymerization reactor 18 Droplet transfer pipe

Claims (4)

A strongly acidic ion exchange resin in which a strong acid group is introduced into a gel-type bead obtained by a copolymerization reaction of a polymerizable monomer containing a styrene monomer and a crosslinkable monomer is brought into contact with a liquid containing bis (hydroxyphenyl) propanes. In the method for producing bisphenol A including an isomerization step of isomerizing to bisphenol A, the strongly acidic ion exchange resin has an average particle size of 650 μm or less.   The method for producing bisphenol A according to claim 1, wherein the strongly acidic ion exchange resin has a crosslinking degree of 2 to 6%. In the method for producing bisphenol A comprising the following steps (A) to (G), the following (F
) A method for producing bisphenol A, wherein the strongly acidic ion exchange resin used in the step has an average particle size of 650 μm or less.
(A) a condensation reaction step in which an excess amount of phenol and acetone is subjected to a condensation reaction in the presence of an acidic catalyst;
(B) a concentration step for concentrating the reaction mixture obtained in the condensation reaction step;
(C) a crystallization / solid-liquid separation step for crystallizing an adduct of bisphenol A and phenol by cooling the concentrate obtained in the concentration step and separating the adduct into a mother liquor,
(D) a phenol removal step of removing phenol from an adduct of bisphenol A and phenol and recovering bisphenol A; and
(E) having a granulation step of granulating bisphenol A obtained in the phenol removal step;
(F) an isomerization step in which at least a part of the mother liquor obtained in the crystallization / solid-liquid separation step is brought into contact with a strongly acidic ion exchange resin to isomerize to bisphenol A;
(G) A bisphenol recovery step of separating and recovering bisphenol A from the isomerization solution obtained in the isomerization step.   4. The method for producing bisphenol A according to claim 3, wherein the strongly acidic ion exchange resin has a particle size of 30 to 650 [mu] m is 50% or more of the whole.

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