SU589740A1 - Method of producing esters - Google Patents

Description

(54) METHOD OF OBTAINING COMPLEX ETHERS

An advanced method for the preparation of esters of dicarboxylic acid-aliphatic series and di-nli polycarboxylic acids of the aromatic series, which are various polymeric materials.

The known method of obtaining ester eger1}) by ikation of aromatic dihydric acids with saturated unsubstituted al5 "}) attic alcohols, during the precipitation, as a catalyst, organic compounds of tetravalent titanium and zinc compounds i |.

Odrshko this process is long. The closest to the present invention is a method for producing aromatic dicarboxylic acid esters of 2j, which involves the esterification of the corresponding acid or its anhydride with an aliphatic alcohol of normal or isostrate containing 4-12 carbon atoms, or a mixture of these alcohols in the presence of a titanium-containing catalyst when heated to 15O- 250

with a gradual decrease in pressure from atmospheric to residual 80 mm PTJC

Upon reaching a given acid number, the ether is purified by treating the crude ether with a solution of mineral alkali.

However, during the esterification process, the titanium-containing catalyst is partially hydrolyzed to form insoluble titanium hydroxide. At the same time, the activity of the catalyst decreases, as a result of which the duration of the process increases.

Hydrogate titanium litters tech. The equipment, especially the heat exchange surface, is deposited in the form k (s, so the equipment comes to clean periodically. The duration of the process, due to the deterioration of heat transfer from the heat exchange surface, increases. The duration of the process leads to a corresponding increase in energy consumption. The purpose of the invention is to intensify process and reduced energy consumption. To achieve the goal of the objective, dicarboxylic acid is proposed for the aliphatic row of the i- di- or popicarboxylic acid. an aromatic acid with carbon numbers of 6-18 or its anhydride is heated with normal or iso-aliphatic alcohol with carbon numbers of 4-12 or with a mixture of these alcohols up to 150-200 ° C under atmospheric pressure or to residual 2SO mm and maintain the reaction mixture at the specified temperature and pressure for about 5-6 h. Then a titanium-containing catalyst is introduced into the reaction mixture and the process is completed when a given acid number is reached at a temperature of 17025 ° C and a pressure from atmospheric to residual 80 mm Hg The desired product is isolated in a known manner. In the reaction mixture, an excess of alcohol and volatile components are distilled off with acute superheated iar, residues of catalysis are washed with water and neutralized with a weakly alkaline solution, after which the reaction mixture is worked up. sorbents, distilled vrdu and filter. The yield of the target product is 99.2-09.5%. The difference between this OTjaaeecTi method is that the aliphatic acid dicarboxylic acid or di- or polycarboxylic acid of the aromatic carbon number or its anhydride is used as the acid or its anhydride, the reaction mass is first heated to 15 ° C with pressure from atmospheric D residual 250 mm Hg. and maintain the temperature and pressure data in the flow {0.5-6 h, then the titanium-containing catalyst is introduced into the reaction mass and the process is completed at 17 O-250 ° C and atmospheric to residual pressure 80 mm Hg. The method has advantages over the known one. The titanium closes the catalyst, which is introduced into the ampli? C after the main part of the reaction water is distilled off, is practically not hydrolyzed, which makes it possible to increase the activity of the catalyst and, accordingly, shorten the reaction time. Pszholysu does not hydrolyze the catalyst, the titanium hydroxide is present in the reaction mixture, and therefore, there is no need for periodic cleaning of the equipment and the heat transfer from the heat exchange surfaces to the reaction mixture is improved, since the latter are not clogged with titanium hydrostatic. As a result, the duration of the process is shortened by 10-25% due to faster heating. The shortening of the process duration results in a corresponding reduction in energy costs. The method can be carried out on installations of both periodic and continuous action. With periodic production, carboxylic acid or its anhydride is loaded into the reactor and the reaction mixture is heated with alcohol at an atmospheric pressure of up to 250 mmHg. to a temperature of 15–200 ° C and maintained for 0.5–6 h at the indicated temperature. Then, a titanium-containing catalysis Op is introduced into the reaction mixture and the process is completed at 170250 ° C and atmospheric to residual pressure of 80 mm Hg. In the case of continuous production, carboxylic acid or its anhydride and alcohol are continuously injected at a predetermined ratio into the forphyrizer, which is served by the first apparatus of the cascade of reactors or the first section of a partitioned reactor. In the forizer, the temperature is maintained at 15 ° -200 ° C and the pressure. From a sphere to a residual 250 mm Hg The reaction mixture from a constant foreofermer level is continuously withdrawn into the second cascade apparatus or into the second section of the sectional reactor, where the titanium-containing catalyst is introduced and where the temperature is maintained at 17 ° –250 ° С and the pressure is from atmospheric to residual VO mm. If the continuous plant includes a bottoms foraerizer and a partitioned etherizer, the mixture of the acid or its anhydride with alcohol is introduced into the forg and the titanium-containing catalyst into the first section of the sectional reactor. EXAMPLE 1. At a periodic installation, an operation that includes a one-liter flask with a stirrer and a jacket to supply a heating agent, a condensate water {-fridge, connected to a Florentine vessel with a vacuum line and a water receiver, receive di- (2- ethylgvxyl) phthalate by the interaction of phthalic anhydride with 2-ethylhexanol in the presence of tetrabutylsigitane. The vapors of the reaction water and 2-ethyl-gwxanol, boiled away in the reaction process, are sent to refrigerators, from where the cooled K01 condensate is sent to a Florentine vessel. From the Florentine vessel, water through the bottom drain is continuously withdrawn into the water receiver, and alcohol from the top level is continuously transferred through a hydraulic seal along the buried perforated drain to the reaction flask. The flask is charged with 148 g of phthalic anhydride, 364 g of 2-ethylhexanol, and the reaction mixture is heated to 190 ° C with a residual pressure of 460 mm Hg. and maintain it at the specified temperature for 2 hours. Then, 1.5 g of tetrabutoxytitanium is introduced into the reaction mass at 200 ° C and a residual pressure of 360 mm Hg. they react to the kinetic number 0.5 mgKOH / g. The total time of the etheri}) process, including the heating step, is 195 minutes. For comparison, a similar synthesis by the known technology is used. The flask is charged with 148 g of phthalic anhydride, 364 g of 2-ethylhexanol and 1.5 g of tetrabut titanium. The reaction mixture is heated to 2OO C and with residual

Color iodometrical ikale, №

o3

Density at 20 C, g / cm

Acid number, mg KOH / g Number of ohms; Uni, mg KOH / g

Volume resistivity at 20 ° C, ohm-cm

The quality of plasticizers obtained by various methods is almost the same and corresponds to 1 sorghum according to GOST 8728-66.

PRI mme R 2. In the installation described in Example 1, dialkyl adipate is obtained by reacting an adipin quartz with a mixture of normal isodools Cd – Cd. 400 g of alcohols Cu – Co and 202 g of adipic acid are loaded into the flask.

heat the reaction mass to 180 C at atmospheric pressure and you, 5 (3,982

0.06 289

eleven

eleven

3-10

3.1: 10

keep at this temperature for 0.5 h. Next, 2 g of tetrabutoxytitanium is introduced into the reaction mixture and at 190 ° C a residual pressure of 60 mm Hg. react to an acid number of 0.5 mg KOH / g. The esterification reaction time is 195 minutes.

For comparison, a similar synthesis is carried out by a known technology with the simultaneous introduction of reagents and catalyst into the process. The time required to reach an acid number of 0.5 mgKOH / g, a pressure of 360 mm Hg. Art. the reaction is adjusted to an acid value of 0.5 mg KOH / g. The total process time is 235 mV. The yield of the product in both cases reaches 99.5 wt.%. To compare the quality of plasticizers obtained by known and proposed methods, samples are taken that are processed by a known method, namely, at 150 ° C and a residual pressure of 60 mm Hg. Excess alcohol and volatile components are distilled off with a solid superheated steam, then the raw di- (2-ethylhexyl) phthalate is cooled to 95 ° C and treated with a 45% aqueous solution of soda ash at this temperature and atmospheric pressure for 0.5 h. After that, acticulants ugy and clay (sorbent consumption according to O, 5% by weight of plasticizer) and at a temperature of 1OO C and residual pressure of ZOO mm rglt are introduced. the treatment is carried out with sorbents a for 0.5 h. Then, ar 120 C and residual pressure of 10 mm | Hg the water is distilled off and the col content is filtered. The results of the qualitative analysis of ether obtained by the proposed and known methods are shown in the table.

in this case, it is 260 minutes. The yield of the product in both cases reaches 99.2 wt. %

PRI me R 3. In the installation described in example 1, trioctyl trimellitate is obtained by the interaction of 2-ethylhexanol and trimellitic acid, the reaction mixture is heated to a temperature of 150 ° C with a residual pressure of 250 mm Hg. and kept under these conditions for 3 hours. Next, 2.1 g of tetraiso-opo-titanium is introduced into the reaction mixture and the process is completed at 170 ° C and a residual pressure of 80 mm Hg. The acid number of the crude ester is O, 45mg KOH / The total esterification reaction time is 295 minutes. For comparison, a similar synthesis is carried out according to known technology with the introduction of a catalyst into the initial reaction mixture. The burden required to reach an acid value of 0.5 mgKOH / g is 325 minutes. The product yield in either case is 99.5%. PRI me R 4. In the installation described in example 1, dodecyl phthalate is obtained by reacting dodecyl alcohol with phthalic anhydride. 4OO g of dodecyl alcohol and 74 g of phthalic anhydride are loaded into the flask, then the reagents are heated to 2OO C at atmospheric pressure and the reaction mixture is kept at this temperature for 1 hour. Then 1, O g of tetra- (2-ethylhexyl) is introduced into the reaction mixture. titanium and at a temperature and residual pressure of 460 mm Hg. they react to an acid number of 0.35 mg KOH / G. The process time is 210 minutes. The product yield in both cases is above 99%. PRI me R 5. In the installation described in Example 1, butyl stearate is obtained by reacting stearic acid and butano. 5OO g of stearic acid and 185 butanol are loaded into the reaction flask, the reagents are heated to 180 ° C at atmospheric pressure and kept at this temperature for 1 hour. Next, 2.2 g of tetrabut (titanium and the process is completed at 190 ° C and atmospheric pressure. The acid number of the raw butyl stearate obtained is O, 75 mgKOH / Reaction time is 210 minutes. The product has a yield of 99.5% in both cases. Pr and m 6. Dialkyl phthalate is obtained by reacting phthalic anhydride with alcohols presence

Claims (1)

tetrabutoxygigan continuous way. Reagents are fed continuously to a 20-liter reactor: 0.85 kg / h of phthalic anhydride and 2.1 kg / h of a mixture of synthetic fatty alcohols C - 190 ° C and atmospheric pressure are maintained in this apparatus. Alcohol and water boiling off from the reactor are condensed and cooled in the refrigerator, after. What is divided in a Florentine vessel with the return of alcohol to the process and the discharge of water into the sewer system. The residence time in the cube (pulp reactor 6 hours. From the bottom reactor, the reaction mass is continuously fed from a constant level into the first section of the sectioned reactor, consisting of 6 sections with a total volume of 12 p. In the same section, getrabutoxytigane is introduced at a rate of О, ОО85 kg / h. The temperature in the first two sections of the reactor is 19 ° C, and in the remaining sections 2 ° C, the residual pressure is 25 ° C mmg. Dialkylfat atoms with an acid number of 0.3-0 are taken from the bottom section section reactive 5 mg KOH / G. For comparison, a similar synthesis is carried out according to the known The technologies are carried out as described earlier, but the reagent and the catalyst are simultaneously continuously introduced into the bottom reactor.At the same residence time, the acid value of the crude ether at the exit of the reactor is 0.6 / 0.9 mg KOH / g. of the invention. A method for producing esters by the esterification of dicarboxylic acid or its anhydride with aliphatic alcohol of normal or from trophic OC with 4-12 carbon atoms or with a mixture of these alcohols in the presence of a tantroic -1 catalyst at 15 O-250 C and atmospheric to residual pressure 80 mmHg, characterized by i-eM, that, in order to intensify the process and reduce energy consumption, dicarboxylic acid is used as the acid or its anhydride, alchophatically, or OR of a di- or polycarboxylic acid of an aromatic series with a carbon number of 6- 18 or its anhydride and the reaction mass is first heated to 15O-2OO C at a pressure from atmospheric) to a residual 25O mm Hg. and hold out at a given temperature and pressure for 0 hours, after which the titanium-containing catalysis is introduced into the reaction mass and the process is completed 9589740 .10 at 17 0-250 0 and pressure from atmospheres-1. US patent N 3418339, foot to a residual 80 mm Hg, cp. 260-475, 1974. Sources of information accepted by v2. French Patent No. 2181956, attention in the examination; C 07 C 67/02, 1974,