CS220822B1

CS220822B1 - Way of preparing dian

Info

Publication number: CS220822B1
Application number: CS410581A
Authority: CS
Inventors: Oldrich Jerabek; Stanislav Jirasek; Jiri Kroupa; Vitezslav Homola
Original assignee: Oldrich Jerabek; Stanislav Jirasek; Jiri Kroupa; Vitezslav Homola
Priority date: 1981-06-03
Filing date: 1981-06-03
Publication date: 1983-04-29

Abstract

Předmětem vynálezu je způsob přípravy dianu kondenzací fenolu s acetonem. Úkolem bylo dosáhnout vysokého výtěžku a čistoty produktu při maximální efektivitě celého procesu. Výsledku bylo dosaženo vedením reakce acetonu s fenolem za přítomnosti komplexního katalyzátoru, připraveného částečnou neutralizací silně kyselých katexů s vysokou aktivitou sekundárními nebo terciárními aminothioly.The subject of the invention is a method for preparing diane by condensation of phenol with acetone. The task was to achieve a high yield and purity of the product with maximum efficiency of the entire process. The result was achieved by conducting the reaction of acetone with phenol in the presence of a complex catalyst, prepared by partial neutralization of strongly acidic cation exchangers with high activity with secondary or tertiary aminothiols.

Description

The subject of the invention is a method for preparing diane by condensation of phenol with acetone.

The task was to achieve high yield and product purity while maximizing the efficiency of the entire process.

The result was achieved by conducting the reaction of acetone with phenol in the presence of a complex catalyst, prepared by partial neutralization of strongly acidic cation exchangers with high activity by secondary or tertiary aminothiols.

The subject of the invention is a method for preparing diane, catalyzed by strongly acidic cation exchangers, modified with compounds containing thiol and amine groups.

Dian, or also bisphenol A or diphenolpropane, is one of the basic raw materials needed in the production of epoxy resins, polycarbonates, some special condensates with formaldehyde, etc. It is produced by acid-catalyzed condensation of phenol with acetone. The acidic environment was originally created with dilute sulfuric acid, later with concentrated hydrochloric acid, but processes using phosphoric acid and combinations of the aforementioned acids are known. The acidic environment itself is not sufficient and for the condensation to proceed sufficiently quickly, it is necessary to use catalysts, which are usually various compounds containing —SH groups, such as hydrogen sulfide, mercaptans, etc. Condensation in an acidic environment caused a number of problems of a technical and technological nature, the most serious of which were corrosion problems and the processing of difficult strongly acidic waste. The use of acids was later replaced by the use of strongly acidic ion exchangers, especially cation exchangers based on phenol-formaldehyde condensates containing —SO3H groups and sulfonated styrene-divinylbenzene copolymers.

This technology found wider application only after the preparation of cation exchangers with high surface activity was solved, allowing for sufficiently high reaction rates of condensation. The advantage of the technology of condensation of phenol with acetone in the presence of cation exchangers is the easy separation of cation exchangers from the reaction mixture, the elimination of difficulties in processing large volumes of acidic waste and also greater purity of the product. The technology itself is most often flow-through, with the cation exchanger forming a catalyst bed, which can be stationary or in suspension. The stream of raw materials can flow through the cation exchanger either in the direction of the lines of force or against the direction of the lines of force of the gravitational field.

The most serious problem was the problem of a sufficiently effective catalyst, which determines the magnitude of the condensation reaction rates and thus the achieved product yield. The mercaptans used are effective, but they pollute the product. Therefore, a certain compromise is chosen, where at the cost of losing a smaller amount of —SO3H groups, the necessary amount of catalyst is anchored to the cation exchange resin, which are aminoalkylthiols Ci to C4, thiazolidines and thiols containing quaternary ammonium groups. The complex formed by partial neutralization of cation exchanges with the appropriate aminothiol represents a very effective catalytic system for the condensation of phenol with acetone. However, the disadvantage is the very difficult availability and high price of these special aminothiols and in many cases their weak anchoring to the cation exchange resin, causing a gradual decrease in the catalytic efficiency of the complex.

It has now been found that palm can be prepared by condensation of phenol with acetone in a molar ratio of 5 to 15 to 1 by the action of strongly acidic cation exchangers catalyzed by aminothiols, by a process according to the invention, which consists in bringing a mixture of phenol with acetone into contact with a bed of strongly acidic cation exchanger, of which 5 to 30% of the — SO3H groups are neutralized by compounds of the general formula

Y — X - SH where

Rl\'

Y is 'N—

R2 while

R 1 is H, C 1 to C 10 alkyl, (CH 2 )„ -SH

R2 is alkyl C1 to C10, (CH2) _n -SH, alkylaromatic residue n is 1 to 10 or alkylheterocyclic residue C1 to C12, optionally substituted with —OH, —SH on the alkyl chain, bonded via tertiary nitrogen and X is alkylene C2 or _Cm , where m is 3 to 12, wherein carbon atoms C2 to _{Cm_i} may be substituted with —OH or —SH at a space velocity of 0.5 to 8 h ^-1 and a temperature of 313 to 373 K, after which the entrained cation exchange resin, unreacted substances and water of reaction are separated.

The advantage of the process according to the invention is that it achieves high yields and product purity in the synthesis of diane. Another significant advantage of the preparation method according to the invention is that it provides a final reaction mixture from which the phenol-diane adduct is eliminated significantly more easily and more quickly, especially at relatively higher temperatures, than from a mixture with the same diane concentration prepared by the previous reaction methods.

This indicates a certain specific effect of tertiary or secondary aminothiols on the properties of the reaction mixture. The several times faster and easier crystallization precipitation of the phenol-diane adduct achieved by the process according to the invention can be advantageously used in the refining of technical diane. By controlling the crystallization temperature, we can regulate the amount of precipitated adduct from the reaction mixture in a relatively small crystallization device with high efficiency.

Another advantage of the invention is that it allows operation in shorter catalyst life cycles and thus achieves higher average performances of the production equipment.

Aminothiols of the general formula for the method according to the invention can be easily prepared in the required purity from commonly available raw materials. Strongly acidic cation exchangers prepared by sulfonation of styrene-divinylbenzene copolymers with high surface activity are used. Part of the formed —SO3H groups (5 to 30 percent) is neutralized by aminothiols of the general formula. The cation exchanger thus prepared forms a complex catalyst, which is introduced in the required amount into a flow reactor, where it forms a catalytic bed. After the activity of the bed has decreased below the tolerable limit, the worn-out complex catalyst must be replaced with a new one. The diane obtained has a high content of the desired p, p'-isomer and a lower content of undesirable impurities, due to the greater selectivity of the catalyst for the method according to the invention.

Example 1 to 6

The cation exchange resin, prepared by sulfonation of a styrene-di8 vinylbenzene copolymer containing 4.0 wt. % divinylbenzene, whose capacity was 5.1 equivalents/1 kg of dry cation exchange resin, was partially neutralized with aminothiol as follows:

A water-swollen cation exchange resin containing 3 g of dry matter was placed in a flask equipped with a stirrer and an aqueous solution of aminothiol hydrochloride was added. The mixture was stirred for 2 to 4 hours, after which the mother liquor was aspirated and the treated cation exchange resin was washed with distilled water.

Table 1

Aminothiol hydrochloride used Solution concentration Amount of solution Conditions for the process according to the invention in the process according to the invention (% by weight) (g) reaction temperature reaction rate

T(K)' h ^_1

LO OJ Η Η H

CO CO CO CQ CO CM 'Φ Tfl Three what what what what what fx. co co^ co in 00 θ''Φ cnT

CM CM CO CM CO in

WHAT's up

CM about

what is it? in ΙΟ θ'θ' O rT rH

O

>μ, >řM

P P P P' o

>t-4

P

The obtained complex catalyst was transferred in an amount of 9.7 g (at a dry matter of 31.2 wt. percent) into a tubular reactor with a diameter of 8 mm and a length of 250 mm, tempered to the reaction temperature. By introducing phenol preheated to this temperature, the catalyst bed was dewatered, after which a mixture of phenol and acetone in a molar ratio of 8 to 1 was brought into contact with the catalyst through the bottom of the reactor. After separation of unreacted phenol, acetone and reaction water, a product with the following parameters was obtained.

Table 2

Complex catalyst Diane yield (% of theory) Melting point (K) Dian parameters BPX wt. % 4,4'-iso. wt. % 2.4 -is. wt. % 1 41.6 426.0 90.1 5.6 1.26 2 50.3 425.6 89.5 5.8 1.4 3 51.9 426.3 90.8 5.4 1.11 4 52.6 426.4 91.1 4.9 1.07 5 53.0 425.9 90.3 5.2 1.20 6 51.4 425.1 88.7 5.7 1.42

Example 7 to 10 dehydrated with phenol, preheated to a temperature

343 K. The tube reactor was heated to 343 K.

The cation exchange resin described in Example 1 was the same

Claims

I will invent the object

A process for the preparation of diane by condensation of phenol with acetone in a molar ratio of 5 to 15 to 1 by the action of strongly acidic cation exchangers with high surface activity under catalysis of aminoalkylthiols, characterized in that the phenol / acetone mixture is contacted with a strongly acidic cation exchange bed. 30% of the —SO5H groups are neutralized by the compounds of formula

Y — X — SH where

Ri where

R1 is H, C1-C10 alkyl, (CH2) _n -SH

R2 is Ci to Cio alkyl, (Chajna -SH alkylaromatic radical n is 1 to 10 or alkylheterocyclic radical Cl-C12, optionally substituted with -OH, -SH on the alkyl chain which is bonded via a tertiary nitrogen and X is alkylene of C 2 or C _m, wherein m is 3 to 12, wherein the carbon atoms C2 to _m _i can be substituted with -OH or -SH space velocity of from 0.5 to 8 h ^_1 at a temperature of 313 to 373 ° K, after which cation exchanger is separated entrained, unreacted materials and reaction water.