CN1178213A - Manufacture of bisphenol-A - Google Patents

Abstract

An integrated process for the preparation and recovery of BPA in pure form utilizes a series of steps to crystallize pure BPA of improved color stability and recycle separated impurities to improve overall yields. The principal impurity recycled to the process is Omicron, Rho-BPA which functions as a color stabilizer in the product and in polycarbonate resins prepared from the BPA.

Description

The preparation of dihydroxyphenyl propane

The present invention relates to the preparation method of dihydroxyphenyl propane.

Dihydric phenol, 2,2-double mutual-hydroxy phenenyl oxide (often being called " dihydroxyphenyl propane ", " BPA " or " pp-BPA ") industrial be by in the presence of an acidic catalyst, the condensation of acetone of 2 moles phenol and 1 mole is formed.In reaction, phenol usage exceeds 1 mole of stoichiometric calculation demand.In condensation reaction, form the impurity that some are considered to purpose product B PA, for example the by product of the isomeric form of BPA.These impurity are brought in the product stream in self-condensation reaction district, comprise water, by described catalyzer deutero-trace acidic material, unreacted phenol and acetone.Generally speaking, the purifying of purpose product B PA is an expensive and rapid process of multistep.

The main application of BPA is the monomer as polyreaction, so that obtain polycarbonate and polyestercarbonate resin.With regard to many these class polymer resins, color, lack color and color stability for its end-use for example transparent lens be important.Recently, found one of isomer of BPA, 2-(4-hydroxyl-phenyl)-2-(2-hydroxy phenyl) propane (be also referred to as o, p-BPA, it in above-mentioned mechanicals as impurity) in the resin of the preparation of the polymerization by BPA as colour stabilizer.Its recent research shows that in polymerization process, at least about the o of 100ppm concentration, p-BPA can prepare the polycarbonate resin of the color (measuring according to yellowness index) with improvement in described BPA monomer.

The present invention utilizes above-mentioned latest find, by improving the preparation of monomers B PA, so that increase the o in the product, and the content of p-BPA impurity, thereby increase its value as the polycarbonate resin precursor of colour stable.The advantage that the present invention improves one's methods is to avoid increasing with BPA to prepare for example concentration of BPX-II, BPX-I, dimer etc. of other relevant impurity.

Two kinds of important BPA industry synthetic methods that are usually used in are arranged.A kind of is and the relevant method of used an acidic catalyst (hydrogenchloride) to be sometimes referred to as " HCl " method.

Second kind of industrial building-up reactions comprises uses the active ion exchange catalysts, is called as " IER " method sometimes.Two kinds of synthetic methods all comprise makes phenol, acetone and circulation by product by comprising the reactor of an acidic catalyst, passes through the BPA purge process then." IER method " can be finished according to one of two kinds of approach: first kind of approach be, up to basic whole acetone are exhausted till; Second kind of approach also is that optimal approach is " part acetone conversion ".This technology is introduced in United States Patent (USP) the 5315042nd, is attached among the present invention, as a reference at this.Described BPA reaction can be selected in free mercaptan for example the 3-thiohydracrylic acid exists down or the promotor of use and EIR resin chemistry or covalent bonding or do not use the promotor acceleration.These resins are generally known composition, and same its preparation method also is known.For example No. the 3037052nd, the visible United States Patent (USP) of its preparation method, is attached among the present invention as a reference at this.

The reaction effluent of IER method comprises affixture and the BPA isomer by product and the promotor (when using) of unreacted acetone, phenol, BPA, BPA and phenol.This effluent (or HCl method reaction effluent) can be supplied with the reextraction process, so that remove moisture, residual acetone and the phenol of dereaction.

Be used for making phenol condensation with acetone with the visible United States Patent (USP) of more detailed description of the method that obtains BPA No. 4346247, No. 4396728, No. 4400555, No. 4424283, No. 4584416, No. 4766254 and No. 4847433 about above-mentioned, be attached among the present invention as a reference at this.The common ground of all these known methods and process is in the step after condensation reaction, needs purifying and reclaims the BPA product.Another all normal householder method of using in the BPA of HCl or IER preparation method is " recovery method " that is used for reclaiming from efflux flow useful matter.It can produce and reclaim phenol (for example No. 4131749 described content of United States Patent (USP)), also can pass through adduction crystallization (adduct crystallization) (No. the 5210329th, United States Patent (USP)) or finish by distillation (for example, see United States Patent (USP) No. 5300702 or be published in purpose European patent (U.K.) 055251A number in September 13 nineteen ninety-five) by described effluent catalytic cracking.

The present invention improves one's methods for the pure BPA's of production in the fully integrated chemical industry process that begins with condensation reaction products.

The present invention comprises the method for preparing BPA, and it comprises:

(a) in the presence of an acidic catalyst of excessive phenol of stoichiometric calculation and catalytic proportions, make phenol and acetone in the reaction zone condensation, thereby, the reaction zone effluent that obtains comprising unreacted phenol, unreacted acetone, water, tar and comprise BPA isomer by product, described BPA isomer by product comprises the o in the mixture with the required BPA of phenol addition, p-BPA;

(b) crystallization of BPA/ phenol affixture is separated out from this effluent, stay mother liquor;

(c) from this process, emit the described mother liquor of at least a portion;

(d) with isolated BPA/ phenol affixture crystallization recrystallization;

(e) dehydration and the distillation mother liquor of emitting are so that obtain comprising o, the lighting end of p-BPA; With

(f) at least a portion lighting end was added before above-mentioned re-crystallization step (d) from mother liquor in the crystallization of isolated BPA/ phenol affixture, so that regulate wherein o, p-bis-phenol content is to the ratio that makes colour stable.

Accompanying drawing is for showing the block diagram of embodiment of the invention method.

Industrial important method for the preparation of BPA comprises: at acidic catalyst agent and chemistry meter Excessive phenol reactant thing exists lower, makes 2 moles phenol and 1 mole condensation of acetone, For example referring to above-mentioned United States Patent (USP). As the accompanying drawing that is used for explanation embodiments of the invention method Shown in, this reaction is the initial point that rises of the inventive method. Can use any previous reaction condition and Catalyst is in order to obtain carrying out according to the inventive method the reaction zone outflow thing of subsequent treatment.

The method of condensing of introducing in No. the 5315042nd, the preferred United States Patent (USP) is attached to this at this In bright as a reference.

Described in accompanying drawing, condensation reaction generally can be carried out in reaction zone (12). Generally To comprise BPA phenol crude product, BPA isomers [o that comprises 0-5% (weight), p-BPA], water, The reaction effluent of acetone and other byproduct of reaction is brought multi-step crystallization process into, wherein, and extremely Carry out less a crystallization process (unit 14) and a recrystallization process (unit 16), in order to make BPA/ phenol addition thing crystallization. Behind crystallization each time, 18,20 advance in the unit Row solid/liquid separation (filtration or centrifugal) is in order to isolate mother liquor. In described crystallization and filtration After the process, remove the phenol in the described pure addition thing in phenol recovery unit 22, in order to obtain The BPA product.

Pure BPA product from the melting of recovery unit 22 is restored, bag with various forms Draw together at rotary cooling drum and solidify " thin slice " that described melt obtains or obtained by the granulation process " bead ".

Generally make isolated first mother liquor in the BPA/ phenol addition thing crystallization of separating out Dehydration and be circulated back to reaction zone 12 in unit 24 is in order to reclaim the section that is included in the mother liquor Divide phenol and BPA useful component. In addition, can be before the crystallization of addition thing except anhydrate (with not The acetone of reaction, if present). Except moisture, this first's mother liquor generally wraps Contain a high proportion of o, p-BPA, isomerization will in reaction thereafter, take place at reaction zone 12 in it. In order to avoid increasing the undesirable impurity to BPA, the first that will dewater before this Mother liquor remainder lease making exhaust pipeline 25 is discharged to recovery treatment stage by above-mentioned process pipeline, so that Transfer comprises first of phenol and heats up in a steamer branch (reextractor 26). Then, make in the reextractor 26 The product of extracting phenols is processed by destilling tower 30 (or multi-stage column) distillation, in order to separate p, p-Valuable accessory substance light fraction during BPA, benzodihydropyran and other BPA are synthetic. Receive Collection this light fraction in container 32 comprises a high proportion of o, p-BPA, and it can be used to adjust by list O in BPA/ phenol addition thing first crystallization that unit 18 obtains, p-BPA content. Described adjustment Be by with at least a portion from the light fraction of container 32 before unit 16, to provide enough The ratio of colour stable join in the first addition thing crystallization and finish. Colour stable ratio one As in the scope of the pp-BPA of about 0.01-about 3% (weight), preferred 0.01-0.3% (weight), More preferably from about about 0.1% (weight) of 0.015-, most preferably from about about 0.08% (weight) of 0.02-. Advancing Enter before the unit 16, add additive in the product of unit 18 through conduit 36 (such as dotted line institute Show) in technology pipeline 34.

Can use known method, by further distillation, make from stripping column 26, with Comprise the distillation phenol of form of mixtures of some moisture and some acetone with pure, substantially anhydrous State reclaims, so that in reaction zone 12 further condensations.

Following embodiment has introduced and has implemented mode of the present invention and method, and provide by the present inventor contemplated finish optimised form of the present invention, still, do not limited.

Embodiment

Obtain in the industrial production of feeding liquid (residual crystallization solution) by the BPA after crystallization for the first time of the BPA/ of described condensation reactor effluent phenol affixture and sepn process.The aliquots containig analysis of described feeding liquid shows composition shown in the following table 1.

Table 1 Table 2 Table 3 Table 4

Wt％ Wt％ Wt％ Wt％

Phenol 67.81 0.4 0.01 0.01

pp-BPA 25.81 23.3 99.91 99.94

op-BPA 2.38 40.3 0.041 0.007

Dimer 2.04 2.0 0.000 0.000

Chroman 0.61 22.3 0.000 0.000

Spiro 0.25 0.1 0.000 0.000

BPX-I 0.56 0.0 0.001 0.002

BPX-II 0.54 1.0 0.02 0.028

Make above-mentioned mother liquor dehydration, filter and reduce pressure at 35mmHg (absolute pressure), phenol is removed in about 410 distillations down.Less than the pressure of 1mmHg, the second distillation under about 450-470 produces lighting end, shows that by analysis its content sees the above table in 2 approximately.

With part described " gently " cut be added to again the institute isolated, in the BPA/ phenol affixture crystallization with melt form, and carry out recrystallization.After the phenol desorb, the analytical results that recrystallization goes out product sees the above table 3.Table 4 provides one not utilize exemplary composition of the present invention (promptly not adding the material in the table 2 in the table 1 in the recrystallization process of material).

The person skilled in the art will understand the o that increases in described product, the amount of p-BPA will depend on the composition of described lighting end of the composition of first affixture, selected distillation condition, generation and the amount that the described lighting end of after-fractionating stage is sent in selection.The method that the invention provides the useful low-boiling point material of recovery and reuse (o, p-BPA and pp-BPA) and remove " last running " (BPX-I, BPX-II, dimer etc.).Described " last running " by product can be colorific source, can bring out polymerization branching or other physical properties is produced detrimental action.Can change the composition of described light effluent, so that concentration as requested, provide the by product of various compositions.In described light effluent, o, the concentration of p-BPA can be in the scope of about 10% (weight)-Yue 80% (weight).Under the condition of the most normal use, the o that described light effluent has, p-BPA content are about 20% (weight)-Yue 70% (weight).

This principle also is applicable to the industrial BPA method that other uses the rapid purification system of multistep, for example melt recrystallization (for example seeing United States Patent (USP) No. 5243093).In this case, can will be rich in o, the processing effluent of p-BPA to be increasing the o in the product, the concentration of p-BPA and do not have the consumption of obviously influence to be added to a certain stage of described crystallisation process to the concentration of other impurity of product.

At this, described United States Patent (USP) is attached among the present invention, as a reference.

Claims (2)

1. be used to prepare the method for BPA, it comprises:

(a) in the presence of an acidic catalyst of excessive phenol of stoichiometric calculation and catalytic proportions, make phenol and acetone in the reaction zone condensation, thereby, obtain comprising unreacted phenol, unreacted acetone, water, tar and comprise o, the reaction zone effluent of the BPA isomer by product of p-BPA;

(b) crystallization of BPA/ phenol affixture is separated out from this effluent, stay mother liquor;

(c) from this process, emit the described mother liquor of at least a portion;

(d) with isolated BPA/ phenol affixture crystallization recrystallization;

(e) dewater and distill described mother liquor of emitting or by product and flow out thing so that obtain comprising o, the lighting end of p-BPA; With

(f) at least a portion of described lighting end was added before above-mentioned re-crystallization step (d) from mother liquor in the crystallization of isolated described BPA/ phenol affixture, so that regulate wherein o, p-BPA content is to the ratio that makes colour stable.

2. be used to prepare the method for BPA, it comprises:

(a) in the presence of an acidic catalyst of excessive phenol of stoichiometric calculation and catalytic proportions, make phenol and acetone in the reaction zone condensation, thereby, obtain comprising unreacted phenol, unreacted acetone, water, tar and comprise o, the reaction zone effluent of the BPA isomer by product of p-BPA;

(b) crystallization of BPA/ phenol affixture is separated out from this effluent, stay mother liquor;

(c) before crystallization, by removing moisture in described mother liquor or reactor and the effluent;

(d) Recycling Mother Solution to the reaction zone with the dehydration of described first part further reacts;

(e) from described process, emit second section dehydration mother liquor;

(f) recrystallization is carried out in crystallization to isolated BPA/ phenol affixture;

(g) from the affixture of recrystallization, remove phenol;

(h) extracting phenols from described second section dehydration mother liquor of emitting;

(i) the described liquid of emitting of removing phenol of distillation comprises o, the lighting end of p-BPA so that shift; With

(j) before above-mentioned re-crystallization step (f), the described lighting end of at least a portion is added in the crystallization of the isolated BPA/ phenol of described mother liquor affixture, so that regulate its o, p-BPA content is to the ratio that makes colour stable.

Images