CS214091B1 - Ionex catalyst - Google Patents

Abstract

The invention relates to an ion exchange catalyst, the polymer skeleton of which is formed by a copolymer of styrene with an optional admixture of ethylvinylbenzene and divinylbenzene as a crosslinking component. The crosslinking component is heterogeneously distributed in the volume of the ion exchange catalyst grains by the effect of solvents such as alcohols with 1 to 10 C either alone or in a mixture with aromatic hydrocarbons with 6 to 9 C, aliphatic halogenated hydrocarbons with 1 to 4 C or halogenated benzene derivatives, added to the polymerization mixture during the preparation of the polymer skeleton. The process according to the invention primarily enables easy removal of alcohols from the resulting polymer. In addition, in the case of alcohols, the lipophilic character of the molecule can be regulated by changing the length of the carbon chain and the desired modification of the polymer structure can be achieved without the addition of butanone. The essence of the invention and the possibilities of its use are best seen from the examples of use.

Description

The invention relates to an ion exchange catalyst. The copyright certificate is dependent on copyright certificate No. 191,785.

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Strongly acidic organic ion exchangers are increasingly used as catalysts for a large number of industrially important reactions, such as esterification, hydration, alkylation, condensation and others. Their advantage over soluble acids is easy separation from the reaction mixture, the possibility of operating the reaction in a continuous arrangement and the elimination of corrosion problems. Unlike classical catalysts with an inorganic skeleton, the reaction catalyzed by ion exchangers does not take place on the surface, but predominantly in the gel of the polymer mass. The nature of the structure of the polymer mass therefore has a determining influence on the catalytic activity of ion exchangers. The catalyzed reaction can only take place at a high rate in a well-permeable, low-crosslinked polymer mass, which, however, has a high mechanical strength. However, increasing the content of the reinforcing component, which improves the mechanical properties, results in a noticeable decrease in catalytic activity.

In the patent application AO 191 785, a method of preparing ion exchangers particularly suitable for catalytic purposes was described, in which good catalytic activity was achieved while maintaining satisfactory mechanical properties by creating a heterogeneous structure of a crosslinked polymer skeleton. A substantial part of the active groups in these ion exchangers is stored in a permeable, low-crosslinked polymer and the higher crosslinked residue of the polymer mass serves as a mechanical reinforcing element. This is achieved by adding solvents to the polymerization mixture during the preparation of the polymer skeleton of the ion exchanger catalyst. Two groups of solvents or their mixtures are used for this. The first group consists of solvents in which the resulting polymer does not swell. Suitable solvents of this type are aliphatic hydrocarbons with 5 to 13 C and fatty acids with 15 to 20 C. The second group consists of solvents in which the resulting polymer swells - suitable solvents are aromatic hydrocarbons with 6 to 9 C, aliphatic halogenated hydrocarbons with 1 to 4 C and halogenated benzene derivatives. The reason for using the addition of solvents to the polyaeration mixture is not the attempt to create a porous structure of the resulting polymer, as described, for example, in Czechoslovak Pat. 102 478 or British Pat. 849 122, but the modification of the structure of the polymer mass itself by emphasizing the natural tendenoe of copolymers.

I atyrene and divinylbenzene to the uneven distribution of the reinforcing component. The resulting cation exchange resins therefore have a small specific surface area, less than 10 m /g. ^!

A certain disadvantage of the solvents mentioned by name in AO 191 785 is the difficulty in removing some of these solvents, especially precipitants, from the finished polymer. Fatty acids must be extracted and aliphatic hydrocarbons remain partially absorbed in the polymer mass. The subject of the present invention is the preparation of strongly acidic ion exchangers particularly suitable for catalysis, similar to those described in AO 191 785, characterized in that as modifying solvents added to the starting mixture during the polymerization of its skeletons, alcohols with 1 to 10 C are used either alone or in a mixture with aromatic hydrocarbons with 6 to 9 C, aliphatic halogenated hydrocarbons with 1 to 4 C or halogenated benzene derivatives. The addition of alcohols, especially lower and 1 to 4 C, can be used as a precipitant in the sense of the desired effects according to AO 191 785 and optionally supplemented with an admixture of the aforementioned botnadels. In contrast to the precipitants recommended in the aforementioned copyright certificate, the removal of alcohols from the resulting polymer

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In addition, in the case of alcohols, by changing the length of the carbon chain, the lipophilic nature of the molecule can be regulated and the desired modification of the polymer structure can be achieved even with a single-component additive without a special addition of swelling agents, which can be advantageous from a technological point of view.

Below we present examples of the preparation of ionox catalysts.

Example 1

A mixture of 21.75 g of styrene and 2.33 g of technical divinylbenzene (61.5% DVB), 0.15 g of dibenzoyl peroxide (81% of the active ingredient) and 15.5 g of n-butanol is dispersed in 100 ml of a 0.12% solution of polyvinyl alcohol in which 0.35 g of potato starch has been dissolved. It is polymerized with constant stirring for 4 h at 80 °C and 2 h at 90 °C, then inerts and unreacted components are removed by steam distillation. The copolymer is washed with water and dried for 10 h at 80 °C. Fractions of 0.25 to 1 mm are separated from the dry copolymer. The sorted copolymer is sulfonated with an eightfold excess of 98% by weight after preswelling in 1,2-dichloroethane. sulfuric acid at 80 to 125 °C for 6 h. The excess acid is gradually washed off with water after the sulfonation is complete.

A strongly acidic cation exchange resin with an exchange capacity of 5.23 meq/g is obtained.

Example 2

A mixture of 209 g of styrene, 30.7 g of divinylbenzene (62.5% DVB), 196.2 g of 2-ethylhexanol and 1.5 g of dibenzoyl peroxide (80% of the active ingredient) is dispersed in 1200 g of a 0.15% solution of polyvinyl alcohol in which 4.5 g of potato starch has been dissolved. It is polymerized for 5 h at 76 °C and 5 h at 90 °C, then the inert and unreacted components are distilled off with steam. The copolymer is dried for 6 h at 40 °C and 6 h at 80 °C. The sorted fraction of 0.25 to 1.2 mm is sulfonated according to the procedure of Example 1. A strongly acidic cation exchange resin with an exchange capacity of 5.12 meq/g is obtained.

Example 3

A homogeneous mixture of 180.5 g of styrene, 19.5 g of divinylbenzene (61.5% DVB), 100 g of n-butanol, 100 g of toluene and 1.2 g of dibenzoyl peroxide (80% of the active ingredient) is dispersed in 800 g of a 0.2% solution of polyvinyl alcohol. It is polymerized for 4 h at 80 °C and 6 h at 90 °C. Inerts and unreacted components are distilled off with steam, the copolymer is washed with water and dried for 10 h at 80 °C. The grain fraction with a size of 0.25 to 1 mm is sulfonated according to the procedure of Example 1, thus obtaining a strongly acidic cation exchange resin with an exchange capacity of 5.20 meq/g.

Usage examples

All catalysts listed in preparation examples 1 to 3 were tested for the synthesis reaction of 4,4-(1-methylidene)biphenol (commercial names bisphenol A, diane) in a flow tube microreactor at 70 °C with a reaction mixture of phenol and acetone in a molar ratio of 8:1. The test also included commercial cation exchangers A and B, which are declared by the manufacturer as special ion exchangers for catalysis. All tested ion exchangers were previously modified by neutralizing 15% of the acidic active groups with mercaptoethylamine. The results are shown in the table.

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Activity test results of lonex catalysts.

Synthesis of bisphenol A, temperature 70 °C, reaction ratio of phenol and acetone 8 : 1

Catalyst Catalyst loading (g cat.h/mol acetone) Acetone conversion (X) Example 1 65 45 90 49 130 55 Example 2 65 43 90 51 130 55 Example 3 60 50 90 53 130 61 A 250 26 500 50 B 130 39 260 44 550 58

SUBJECT OF THE INVENTION

Claims (1)

SUBJECT OF THE INVENTION An ion exchange catalyst having a polymeric skeleton consisting of a styrene copolymer with an optional addition of ethylvinylbenzene and divinylbenzene as crosslinking component according to AO No. 191 785, characterized in that the crosslinking component is heterogeneously distributed in the grain volume of the ion exchange catalyst by C1-C10 alcohol solvents. , the cell alone or in admixture with an additive of 0 to 60 wt. aromatic hydrocarbons having from 6 to 9 carbon atoms, aliphatic halogenated hydrocarbons having from 1 to 4 carbon atoms, and nobo halogenated benzene derivatives added to the polymerization mixture in the preparation of the polymer backbone.