SU1038346A1 - Process for preparing electron-exchange resins - Google Patents

Abstract

The invention relates to the area of polymer chemistry, in particular to an electron-exchanger resin, to a process for the preparation thereof, and to the use thereof. The electron-exchanger resin has a three-dimensional structure whose elemental units conform to the formulae below: <IMAGE> in which R is <2bL>CH2 or -SO3H, n is from 1 to 6 and m is from 1 to 3, and <IMAGE> in which R, n and m are as defined above, where the ratio between the units of the formula I and the units of the formula II is from 0.1 to 99.9:99.9 to 0.1. The process for the preparation of said resin comprises sulphonating a mixture of phenol and para-phenylenediamine and subsequently cocondensing the resultant sulphonation product with formaldehyde, where the phenol, para-phenylenediamine and formaldehyde are used in a molar ratio of from 2 to 7:1 to 3:4 to 17. The resin described is used as a structure-forming additive to carbon graphite electrodes intended for the arc melting of metals.

Description

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35 The invention relates to the production of polycondensation resins, and more specifically to the production of polycondensation resins with redox properties, before, "predominantly assigned" for use in the carbon-graphite industry as a catalytic additive that improves the quality of filtered electrodes, as well as to dehydrate the water and get hydrogen peroxide. A known method of producing resins capable of oxidation reactions of reduction, co-condensation with phenol and formaldehyde hydroquinone. The lack of resins - low swelling due to the low content of fixed ionic groups in the matrix, and hence the small static reducing capacity (l, 52, 0 mg-eq. / g). A known method for producing resins. to extract oxygen from water capable of forming n-or o-quinoid structures during oxidation and regeneration. These resins are obtained by the condensation of formaldehyde with phenols, aminophenols, phenylene polyamines or their derivatives, containing less than two amino groups or hydroxyl groups in the p- or o-position 2. The disadvantage of this method is an insignificant number of fixed ionic groups, which leads to low swelling and low static recovery capacity. . There is also known a method for producing granulated redoxite Ghelektro (part of an exchanger)), which is obtained by polycondensation of formalin, pyrocatechin, and an aromatic diamine. Redoxite is obtained by polycondensation of a mixture of formalin, pyrocatechin and an aromatic amine in an inert dispersion. medium containing alcohols with the number of carbon atoms from 3 to 20, at 70 ° C for 2 h, followed by washing with acetone and drying in air or in vacuum at 100. C h However, a small amount of ionic groups fixed on the matrix also leads to a low static resin recovery capacity. In addition, granulation of the resin in the mixture of alcohols and subsequent washing with cetone causes a sharp decrease in the technical and economic performance of the process, and the use of solvents in the production of resin causes an increased fire hazard of the process. The closest to the present invention is a method for producing electron-exchange resins by co-condensation of pre-sulfated phenol and hydroquinone or pyrocatechol with the Ldehyde form. The presence in the matrix of fixed sulfo groups causes an increase in swelling (up to 2.2 2, 3 ml / g) and static reducing capacity (3 3.5 mEq / g | 4}. However, for practical use, electron exchangers with higher swelling and reduction capacity are necessary. The purpose of the invention is to increase the static reduction The objective is achieved by the fact that, according to the method for producing electron-exchange resins, by sulfonating a phenol and a substance capable of reversible redox reactions, followed by co-condensation of the resulting product with formaldehyde, as a substance capable of reversible redox reactions, p-phenylenediamine is used. The first stage of the process consists in ampli? cating sulfonation of phenol and p-phenylenediamine, for which the calculated amount of 95% sulfuric acid is loaded into the reactor, molten phenol and p-fenylendiamina. The sulfonation is carried out at 75-80 ° C for 2 hours. After cooling the reaction mass to 30-ЗЗ, the calculated amount of 37% formalin is poured into the reactor. After stirring at 55-bO-c, the reaction mass is poured into the curing chamber for carrying out the polycondensation process at 70-110 ° C for 24-28 h. The resulting product is crushed and washed with desalted water to the absence of sulfuric acid and low molecular weight in the washing water . At the end of the wash, the resin is dried to the desired humidity. The resin obtained by the proposed method has a specific volume higher than the prototype (3.6 4, 0 ml / g due to the presence of amino groups and sulfo groups in the structure of the polymer matrix. This ensures high kinetic properties and an increase in the reduction capacity to 5-6 mg-eq / g When used in the carbon-graphite industry, the obtained resin possesses better catalytic properties than the prototype, contributing to improved structuring of the electrode by graphitization of electrodes. it greatly improved their quality: heat resistance of electrodes is increased from 4,200 to 4,700 W, the thermal expansion coefficient is reduced from 1.75 to 1 ,, the operating current density of the electrodes increasing the .ets 10-12%.

The proposed method provides. production of electron-exchange resins, possessing simultaneously oxidation-reduction and ion-exchange cation-exchange and anion-exchange properties. Such resins may be used as electron exchangers or ion exchangers, or for both purposes simultaneously.

Example1., 107 parts by weight are loaded into the reactor. 95% sulfuric acid, while the mixer is running, 21.6 parts by weight are introduced. p-phenylenediamine and 28.2 weight.h. molten phenol. The sulfonation is carried out at 75-80 ° C for. 2 hours, then the reaction mixture is cooled to 30-3 and 73 parts by weight are added to the reactor. 37% fomalina. Next, the mass is stirred at 55-60 ° C for 10-15 minutes and poured into the curing chamber. The polycondensation is carried out at 70-100 ° C for 26-28 hours, after which the resin is crushed and washed with desalted water to the absence of sulfuric acid in the washing waters and low molecular weight products.

At the end of the wash, the resin is dried to a moisture content of 15 i 5%.

Electron exchange resin has the following characteristics:

Static

all stopping capacity

mg-eq / g6,2

Specific

volume, ml / g4,4

Sulfur content:

Calculated,%: 16.26.

Found,%: 15.85.

Example 2; 107 parts by weight are charged to the reactor. 95% sulfuric acid, while the mixer is running, 10.8 parts by weight are introduced. p-phenylenediamine and 37.6 weight.h. molten phenol. The sulfonation is carried out at 75-80 ° C for 2 hours. Then the reaction mixture is cooled to 30-35 ° C and 73 parts by weight are added to the reactor. 37% formalin. Next, the mass is stirred at 55-60 ° C for 10-15 min. And poured into the curing chamber. Poly condensation was carried out at 70-100 ° C (for 26-28 hours. Next, the resin was crushed, washed with desalted water at room temperature until no IB washes of acid and low molecular weight products were dried and dried as in Example 1.

Properties of the resulting product: Static recovery capacity,

MG-EKZ / G5,2;

Specific

volume, ml / g4,0

Sulfur content:

 Calculated,%: 11.06.

Found%: 11.42.o

Target .. In the reactor load 107 weight.h. 95% sulfuric acid, with the stirrer 5 injected, 9.2 parts by weight p-phenylenediamine and 40.0 weight.h. molten phenol. The sulfonation is carried out at 75-80 seconds for 2 4, then re. the cooling mass is cooled to 30-35 with 10 and 73 weight parts are fed into the reactor.

37% formalin. The mass is mixed pr 50-60 s. for 1015 minutes and poured into the curing chamber. Polycondensation is carried out

5 at 70-100 ° C for 26-28 hours,

whereupon the resin is crushed and washed with desalted water until sulfuric acid is not present in the washing waters. low molecular weight products. At the end of the rinse, the resin is dried in a manner similar to Example 1.

The electron-exchange resin has the following characteristic: Static reducing capacity, mEq / g4.6 Specific

-volume, ml / g3,8: Sulfur content:

0 Calculated,% 10.19: Found,% 10.07 - PRI me R 4. 107 parts by weight are charged to the reactor. 95% sulfuric acid, - with the mixer running 5, 21.6 parts by weight of p-phenylenediamine are introduced. and 28.2 weight.h. molten phenol.

The sulfonation is carried out at 75-80 ° C. within 2 hours, after an hour; 73 parts by weight of the reaction mixture is cooled to 30–35 Siv. 37%

0 formalin. The mass is stirred at 55-60 ° C for 10-15 minutes and groan into the curing chamber.

Polycondensation is carried out at. 90-110С В - for 24-26 hours, after. 5 of which, the resin was crushed and washed with desalted water until oaric acid and low molecular weight products were absent in the cold waters. At the end of the washing, the resin is dried to a moisture content of 15%.

The electron exchange resin has the following characteristic;

Static recovery em5

, bone, mEq / g5 8

Specific volume, MP / g4,2

Sulfur content:

Calculated% 13,96

Found% 13.85

Example5. 107 parts by weight are loaded into the reactor. 95% sulfuric acid, with the stirrer in operation, | 9.2 parts by weight are introduced. p-phenylenediamine and 40.0 weight.h. molten phenol. The sulfonation is carried out at 75-80 ° C li. 73 parts by weight of 37% formalin are added to the reactor. The mass is stirred at 55-C 0 for 10-15 minutes and drained into the curing chamber. Polycompensation is carried out at 95-110 ° C for 24-26 hours, after which the resin is crushed and washed with desalted water until absent in the washing waters of sulfuric acid and low molecular weight products. At the end of the washing, the resin is dried similarly to Example 1. The electron-exchange resin has the following characteristic: Static reducing capacity, mg-ec / g 4.7. Specific36 volume, ml / t. Sulfur content: Calculated, 7.31 Found,% 7.6. Technical and economic advantages of the proposed method of obtaining electron-exchange resins as compared to the known method consist in obtaining a material with a higher reduction capacity and better structure-forming properties, which allows to reduce the amount of the electron-exchanger introduced in a composite charge, to reduce the specific consumption of electrodes when smelting steel. . In addition, the use of p-phenylendIamine instead of the expensive and deficient hydroquinone or pyrocatechol p-phenylend provides a reduction in the resistance of the electron exchanger obtained by the proposed method and the achievement of a significant economic effect.

Claims (1)

{54) METHOD FOR PRODUCING ELECTRON EXCHANGE RESINS by sulfonation of phenol and a substance capable of reversible redox reactions, followed by co-condensation of the obtained product with formaldehyde, it is necessary to increase the static reduction capacity , p-phenylenediamine is used as a substance capable of reversible redox reactions.