Acrylic acid purification technique and method of production of (meth)acrylic acid ethers

FIELD: chemistry.

SUBSTANCE: invention refers to advanced method of production of (meth)acrylic acid ester including (meth)acrylic acid purification by contacting raw (meth)acrylic acid containing manganese as an impurity manganese, and cation-exchange resin to remove manganese. To ensure contacting raw (meth)acrylic acid and cation-exchange resin, water is pre-added to (meth)acrylic acid. Besides, the method involves reaction of purified (meth)acrylic acid and alcohol with acid catalyst added.

EFFECT: method allows preventing effectively deactivation of the acid catalyst used in etherification reaction, equipment plugging and can ensure stable ester manufacturing.

3 cl, 5 tbl, 5 ex

 

The technical FIELD TO WHICH the INVENTION RELATES

The present invention relates to a method of purifying (meth)acrylic acid and method of producing esters of (meth)acrylic acid.

Prior art

Esters of (meth)acrylic acid are used in various fields in the form of raw materials for paints, adhesives, binders, synthetic resins, fibers or the like. Esters of (meth)acrylic acid usually obtained through the esterification reaction with (meth)acrylic acid and an alcohol in the presence of an acid catalyst.

(Meth)acrylic acid used in the esterification reaction, usually obtained by oxidation reaction of propylene in the gas phase and the de-hydration and then purifying the resulting product to remove the low-boiling and high-boiling impurities. Proposed industrial useful ways in which acrylic acid is purified at low cost by omitting the stage of removal of high-boiling impurities (for example, laid patent application of Japan No. 9-157213, 10-237012, 10-306052 and 2001-213839).

However, when the esterification reaction is subjected to acrylic acid still containing high boiling impurities, which is obtained by the above methods, the following problems occur. That is, acrylic acid contains, in addition to the high-boiling impurities, the components of the transition is metal, the source of which is the polymerization inhibitor used at the stage of purification of acrylic acid. When the acrylic acid-containing components such transition metal, is subjected to the esterification reaction used it a catalyst for the esterification reaction has a tendency significantly influenced by transition metals. For example, in the case where the catalyst for the esterification reaction has the form of a solid acid catalyst, the components of transition metals tend to be absorbed on the active sites of the catalyst, the result is by disabling the catalyst. In addition, in the case of organic acid catalysts components of transition metals interact with the organic acid with the formation of complexes and, therefore, moving in the insoluble state, and dropping into the sediment, resulting in clogging of pipelines, as well as the inability to continue a stable operation for a long period of time.

On the other hand, even if the above-mentioned acrylic acid, containing high-boiling impurities, purify, using the column for the separation of high-boiling impurities, the purified acrylic acid, distilled from the top of the column for the separation of high-boiling impurities, has a tendency to contain components of transition metals due to zahwah is and spray distillation. Thus, even if the esterification reaction is subjected to such purified acrylic acid, the catalyst for the esterification reaction also tends to suffer from the same fundamental problems as described above.

Description of the INVENTION

The TASKS to BE solved BY the present INVENTION

The present invention is made to solve the above problems. The present invention is the provision of a method of purification of (meth)acrylic acid by effective removal of components of transition metals from crude (meth)acrylic acid-containing components of transition metals as impurities, as well as an improved method of producing esters of (meth)acrylic acid, which can prevent the deactivation of the acid catalyst used in the esterification reaction, can solve the above problems, such as blockage in the apparatus, and can ensure stable production of esters of (meth)acrylic acid over a long period of time when using the purified (meth)acrylic acid obtained by the method described above, in the form of raw material.

MEANS FOR SOLVING THIS PROBLEM

As a result of the applicants serious research on solving the above problems found that if the exercise contact the licensing crude (meth)acrylic acid, containing as impurity components of transition metals, with a cation exchange resin to remove from it the components of transition metals, the removal of components of transition metals can be an extremely effective way previously adding to the crude (meth)acrylic acid water. The present invention is made on the basis of the above detection.

For solving the problem in the first aspect of the present invention proposes a method of purification of (meth)acrylic acid by contacting the crude (meth)acrylic acid-containing components of transition metals as impurities, with a cation exchange resin to remove the component of transition metals, and pre-to the crude (meth)acrylic acid add water to contact the crude (meth)acrylic acid with a cation exchange resin.

In the second aspect of the present invention features a method of producing ether (meth)acrylic acid by contacting (meth)acrylic acid with an alcohol in the presence of an acid catalyst, and (meth)acrylic acid, obtained by the above purification method, applied in the form of raw material.

The TECHNICAL RESULT of the present INVENTION

Thus, according to the present invention, a method of purification of (meth)acrylic acid by effectivnogo component removal of transition metals from crude (meth)acrylic acid, containing as impurity components of transition metals, as well as an improved method of producing esters of (meth)acrylic acid, which can prevent the deactivation of the acid catalyst used in the esterification reaction, can solve such problems as clogging in the apparatus, and can ensure stable production of esters of (meth)acrylic acid over a long period of time when using the purified (meth)acrylic acid obtained as described above, in the form of raw material.

The PREFERRED IMPLEMENTATION of THIS INVENTION

The present invention is described in detail below.

First, explained is the method of purification of (meth)acrylic acid according to the present invention. In this method of purification of (meth)acrylic acid according to the present invention the crude (meth)acrylic acid containing components of transition metals as impurities, are used as raw material. As a method of obtaining such a crude (meth)acrylic acid can apply well-known methods. Namely, acrylic acid is obtained by oxidation in the gas phase propane, propylene and/or acrolein and methacrylic acid is obtained by oxidation in the gas phase of isobutylene and/or tert-butyl alcohol. The method of obtaining the acrylic is islote usually includes the following stages (1)to(5). Incidentally, the following stages (1)to(5) typical method of producing acrylic acid, but can also be used to obtain methacrylic acid.

(1) stage of formation gas containing acrylic acid, with the method of the single-stage oxidation, in which acrylic acid is obtained by a direct interaction of propane, propylene and/or acrolein (isobutylene and/or tert-butyl alcohol in the case of methacrylic acid with a gas containing molecular oxygen, in the presence of a solid oxidation catalyst based on molybdenum oxide and others; or a method of two-stage oxidation, which first made by the interaction of propylene with a gas containing molecular oxygen, in the presence of a solid oxidation catalyst based on molybdenum oxide, etc. in the first reaction zone with getting acrolein and then spend the interaction of the obtained acrolein with molecular oxygen in the presence of a solid oxidation catalyst based on molybdenum oxide, etc. in the second reaction zone to obtain acrylic acid.

(2) the stage of interaction in a counter thus obtained gas containing acrylic acid, with water in an absorption column with obtaining an aqueous solution of crude acrylic acid.

(3) the stage of extraction of the resulting aqueous solution of crude acre the gross acid with an organic solvent, such as, for example, methyl isobutyl ketone and Diisobutylene, and subsequent distillation of the resulting extract to obtain the liquid containing acrylic acid, in the form of a residual fraction; or direct azeotropic dehydration of the obtained aqueous solution of the crude acrylic acid with azeotropic agent such as toluene, butyl acetate and octane, for example, at a temperature of from 80 to 100°C at a pressure of from 6,67 to 20 kPa with obtaining a liquid containing acrylic acid, in the form of the residual fraction.

(4) stage of treatment by distillation of the thus obtained liquid containing acrylic acid, to remove low-boiling components, such as acetic acid, and then further distillation of the obtained residual liquid with obtaining crude acrylic acid in the form of a light fraction and a high boiling point substances, including dimer of acrylic acid, in the form of residual liquid.

(5) the stage of further processing by distillation dimer of acrylic acid obtained in the form of residual liquid, obtaining crude acrylic acid in the form of a light fraction.

The crude acrylic acid obtained in the above stage (4) and (5)optionally driven by known methods to remove impurities such as maleic key is lots and aldehydes. As a method of distillation can be applied in various ways, such as simple distillation and accurate distillation. Processing by distillation can be carried out either periodic manner or a continuous manner. Among these methods, the continuous method is preferred from the industrial point of view. As the distillation apparatus can be applied well-known devices. Meanwhile, in some cases, the crude acrylic acid can be directly processed to clean (meth)acrylic acid according to the present invention without the removal of such impurities as maleic acid and aldehydes.

As (meth)acrylic acid is an easily polymerizable compound, the above-described respective stage distillation is usually carried out by adding a known inhibitor of polymerization, i.e. the agent, breaking a chain, or a polymerization retarder. Examples of polymerization inhibitors typically include copper compounds such as copper chloride, copper acetate, copper carbonate, copper acrylate, copper dimethyldithiocarbamate, copper diethyldithiocarbamate, and dibutyldithiocarbamate copper; manganese compounds, such as dialkyldithiocarbamate manganese (where the alkyl groups are methyl, ethyl, propyl or butyl and may be the same or different), definiltely the carbamate manganese, the manganese formate, manganese acetate, octanoate manganese, manganese naphthenate, permanganate manganese and manganese salt and ethylenediaminetetraacetic acid. These polymerization inhibitors can be used in the form of a mixture of any two of them or more or can be used in combination with other inhibitors of polymerization.

Examples of other polymerization inhibitors may include N-oxyl compound, such as tert-butylnitrone, 2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl, 2,2,6,6-tetramethylpiperidine-1-oxyl, 2,2,6,6-tetramethylpiperidine, 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy and 4,4',4”-Tris-1-(2,2,6,6-tetramethylpiperidinyloxy)hospit; phenolic compounds such as hydroquinone, mackinon, pyragollole, catechol and resorcinol; and phenothiazine compounds such as phenothiazines, bis-(a-methylbenzyl)phenothiazines, 3,7-dioctylphthalate and bis-(a-dimethylbenzyl)phenothiazines. These polymerization inhibitors may be used in combination of any two of them or more. The polymerization inhibitors are usually added in amounts of from 1 to 1000 ppm from the amount of crude (meth)acrylic acid.

Crude (meth)acrylic acid, from which impurities are not removed, such as maleic acid and aldehydes, contains components of transition metals usually in an amount of from 1 to 10 ppm from the amount of crude (meth)acrylic acid. Suppose that the components plumage is adnych metals are mixed with the crude (meth)acrylic acid due to the capture of spray above-mentioned polymerization inhibitor, used in the method of obtaining a (meth)acrylic acid during the distillation.

Transition metals, mixed with the (meth)acrylic acid, are metal elements belonging 7-12 groups of the periodic system, with 18 groups of elements. Specific examples of transition metals include manganese, iron, cobalt, Nickel, copper and zinc. Among these transition metals manganese tends to have a significant effect on the catalyst in the esterification reaction used in the method of obtaining a (meth)acrylic acid. Thus, it is preferable to remove manganese from the raw (meth)acrylic acid in the method of purification of (meth)acrylic acid according to the present invention.

In the method of purification of (meth)acrylic acid according to the present invention to the crude (meth)acrylic acid containing the above transition metals, add water and then communicate the resulting mixture with a cation exchange resin. The amount of added water is usually from 1 to 10 wt.%, preferably from 1 to 5 wt.%, of the mass of the crude (meth)acrylic acid-containing transition metals. If the amount of added water is less than 1 wt.%, there can be demonstrated a significant effect of increasing udaljenost to remove components of transition metals from raw (IU is)acrylic acid. If the amount of added water is more than 10 wt.%, the efficiency of the subsequent esterification reaction tends to deteriorate when the mixture of crude (meth)acrylic acid and water then use in the method of producing esters of (meth)acrylic acid.

Water can be added to the crude (meth)acrylic acid containing components of transition metals, at any stage without special restrictions, if this stage goes up to the stage of interaction of the crude (meth)acrylic acid with a cation exchange resin for removal of transition metals. As a method of adding water to the crude (meth)acrylic acid containing components of transition metals, can be applied, for example, a method of directly connecting the piping, through which flows the crude (meth)acrylic acid, to the pipeline for water and method of adding water into the reaction vessel while still ensuring homogeneous mixing and sufficient residence time. Also in the case of products with (meth)acrylic acid water can be added directly to them.

In the present invention believe that the effect of the water added to the crude (meth)acrylic acid, is as follows, although it is not obvious. Namely, the added water act, expanding the pores that are present around the active area, during the adsorption of the components of transition metals, the cation exchange resin and promotora the adsorption of components of transition metals, resulting in increased udaljenost to remove components of transition metals from crude (meth)acrylic acid.

Further interact crude (meth)acrylic acid, to which was added water, with a cation exchange resin to remove components of transition metals. As the cation exchange resin can be used a variety of cation-exchange resin without any special restrictions with regard to the properties of the resin, such as its structure and the density of the stitching. For example, preferably, you can use strongly acidic cation-exchange resin porous type or gel type. Among these resins are particularly preferred strongly acidic cation-exchange resin porous type. Examples of strongly acidic cation-exchange resin porous type may include “MSC-1” produced by Dow Chemical Company, “PK-208”, “PK-212”, “PK-216”, “PK-220”, “PK-208” and “PK-228”, all manufactured by Mitsubishi Chemical Corporation, “Amber List 16”, “IR-116”, “IR-118”, “IR-122, C-26, C-26TR”, “C-264” and “C-265”, all production Rohm & Haas Co., Ltd., “SPC-108 and SPC-112”, both manufactured by Bayer AG, and KC-470” produced by Sumitomo Chemical Co., Ltd. Examples of strongly acidic cation-exchange resin of the gel type may include “HCR-S”, “HCR-W2” and “HGR-W2”, all manufactured by Dow Chemical Company, SK W2”, “SK-106” and “SK-110”, all manufactured by Mitsubishi Chemical Corporation, “Duolite C20H” and “Duolite C255LFH”, both production Rohm & Haas Co., Ltd., and “1221” and “K1431”, both manufactured by Bayer AG. In addition, you can also apply a weak acid cation exchange resin. These cation exchange resin can be applied on one or a mixture of any two of them or more.

The interaction of the crude (meth)acrylic acid, to which was added water, with a cation exchange resin can be, for example, by way of course of the crude (meth)acrylic acid through a fixed layer, consisting of a cation exchange resin. In this case, the amount of crude (meth)acrylic acid flowing through the fixed layer has no particular restriction, and is usually from 0.1 to 10 parts by volume per hour, preferably from 1 to 5 parts by volume per hour per volume part of the cation exchange resin. From the point of view of good operating properties temperature used when interacting crude (meth)acrylic acid with a cation exchange resin, preferably has a value in the range from room temperature to the boiling point of (meth)acrylic acid. In addition, from the viewpoint of good operating properties of the communication process can be preferably carried out at atmospheric pressure.

(Meth)acrylic acid, treated by the purification method of the present invention contains the components of transition metals in quantity, usually exceeding 0.1 ppm, preferably not more than predeliberation by weight (meth)acrylic acid.

The following explains a method of producing esters of (meth)acrylic acid in accordance with the second aspect of the present invention. In this method of producing esters of (meth)acrylic acid according to the present invention carry out the reaction of the esterification of (meth)acrylic acid obtained above described method of purification of (meth)acrylic acid in accordance with the present invention, and alcohol in the presence of an acid catalyst.

Examples of the acid catalyst used in the esterification reaction may include inorganic acids such as sulfuric acid, organic acids such as para-toluensulfonate acid and methanesulfonamide acid, and solid acids such as cation exchange resins. In particular, when using an organic acid catalyst and a solid acid catalysts, the effect of the purified (meth)acrylic acid, from which the removed components of transition metals, can be expressed more noticeable.

Examples of esters of (meth)acrylic acid obtained by the method of the present invention may include methyl(meth)acrylate, ethyl(meth)acrylate, n-butyl(meth)acrylate, isobutyl(meth)acrylate, tert-butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, isononyl(meth)acrylate and methoxyethyl(meth)acrylate. Among these esters are preferred esters obtained the use of alcohols, having 4 or more carbon atoms. The esters obtained by the use of alcohols containing 3 or less carbon atoms, have a boiling point below the boiling point of water, so sometimes may be difficult to drive the water after the esterification reaction.

The esterification reaction can be conducted in the usual way. Namely, in the esterification reaction can appropriately determine the molar ratio of (meth)acrylic acid and alcohols in the form of raw materials, the type and amount of catalyst, methods of interaction and reaction conditions in accordance with the type of alcohol. A solution of the ester of (meth)acrylic acid obtained by the esterification reaction can also be subjected to various stages of processing, such as washing, separation of liquid-liquid extraction, evaporation and distillation to separate the catalyst, and the concentration and purification of the reaction product to obtain at this purified esters of (meth)acrylic acid.

EXAMPLES

The present invention is described in more detail using examples, but the examples are only illustrative and are not intended to limit the scope of the present invention. Meanwhile, below is described a method for quantitative determination contained in the acrylic acid manganese, which is used in the following example the X.

Quantitative determination of manganese

As a pre-processing thermally decompose the sample in the presence of a mixture of sulfuric acid and nitric acid and then mixed with distilled water, getting 50 ml of an aqueous solution. Then, the thus obtained aqueous solution is subjected to quantitative analysis method ICP-AES using an ICP emission spectroscopic instrument "JY-138U" produced by Horiba Limited.

Example 1

Acetate anhydrous manganese(II) are added to a solution containing 99 wt.% acrylic acid and 1 wt.% distilled water, so that the manganese concentration in the solution was 1200 ppm by weight of the solution, thus obtaining a solution of acrylic acid containing manganese. After establishing the temperature of the fixed layer, consisting of 40 ml of strongly acidic cation-exchange resin porous type “DIAION PK-216H” manufactured by Mitsubishi Chemical Corporation, 25aboutWith the above solution of acrylic acid containing manganese, passed through a fixed layer with a flow rate of one volume part per hour per volume fraction of resin. After 2 h, 3 h, 4 h and 5 h after the start of flow of solution through the fixed layer is extracted corresponding effluent streams and analyze them on the concentration of manganese. The concentration of manganese in the corresponding solution is x before and after the flow of solution through the fixed layer shown in table 1.

Table 1
The time course of solutionManganese concentration in the output stream (ppm wt.)
Before passing1200
After 2 hNot defined
After 3 hNot defined
After 4 h30
After 5 h100

This is followed by continuous reaction of esterification thus obtained discharge flow and n-butanol as the alcohol in the presence of para-toluensulfonate acid as an organic acid catalyst, using a conventional apparatus for carrying out the esterification reaction. The result confirmed that there is no deposition of complex organic acid catalyst even after 120 h, it is possible consistently to carry out continuous reaction of esterification.

Comparative example 1

Perform a similar procedure as defined in example 1, except that do not add distilled water. After 2 h, 3 h and 4 h after started the flow of solution through the fixed layer is extracted corresponding effluent streams and analyze them in the concentration of manganese. The concentration of manganese in the respective solutions before and after the flow of solution through the fixed layer shown in table 2.

Table 2
The time course of solutionManganese concentration in the output stream (ppm wt.)
Before passing1200
After 2 h80
After 3 h480
After 4 h810

This is followed by continuous reaction of esterification thus obtained discharge flow and n-butanol as the alcohol in the presence of para-toluensulfonate acid as an organic acid catalyst, using a conventional apparatus for carrying out the esterification reaction. The result confirmed that the nozzle of the apparatus is contaminated with sediment after 40 hours Therefore, the reaction of esterification should be discontinued.

Example 2

Perform a similar procedure as defined in example 1, except that distilled water is added in an amount of 5 wt.%. After 2 h, 3 h, 4 h, 5 h, 12 h and 24 h after the beginning of the PROTEK is of the solution through the fixed layer is extracted corresponding effluent streams and analyze them in the concentration of manganese. The concentration of manganese in the respective solutions before and after the flow of solution through the fixed layer shown in table 3.

Table 3
The time course of solutionManganese concentration in the output stream (ppm wt.)
Before passing1200
After 2 hNot defined
After 3 hNot defined
After 4 hNot defined
After 5 hNot defined
After 12 hNot defined
After 24 h140

Example 3

Perform a similar procedure as defined in example 2, except that the amount of acrylic acid flowing through the fixed layer, changing to 10 ppm. per hour per volume fraction of the resin. After 0.5 h and 2 h after the start of flow of solution through the fixed layer is extracted corresponding effluent streams and analyze them to the ncentratio manganese. The concentration of manganese in the respective solutions before and after the flow of solution through the fixed layer shown in table 4.

Table 4
The time course of solutionManganese concentration in the output stream (ppm wt.)
Before passing1200
After 0.5 h10
After 2 h520

Comparative example 2

Perform a similar procedure as defined in example 3, except that do not add distilled water. After 1 h, 2.5 h and 4 h after the start of flow of solution through the fixed layer is extracted corresponding effluent streams and analyze them in the concentration of manganese. The concentration of manganese in the respective solutions before and after the flow of solution through the fixed layer shown in table 5.

Table 5
The time course of solutionManganese concentration in the output stream (ppm wt.)
Before passing1200
After 1 h1100
After 2.5 h1100
After 4 h1100

1. The method of producing ether (meth)acrylic acid, including cleaning of the (meth)acrylic acid by contacting the crude (meth)acrylic acid, containing as impurities manganese, with cation exchange resin to remove manganese, and to the crude (meth)acrylic acid pre-add water before contacting the crude (meth)acrylic acid with a cation exchange resin, the interaction of the purified (meth)acrylic acid with an alcohol in the presence of an acid catalyst.

2. The method according to claim 1, where the acid catalyst is a cation exchange resin or an organic acid.

3. The method according to claim 2, where the cation exchange resin is a strongly acidic cation-exchange resin porous type.



 

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FIELD: chemistry.

SUBSTANCE: invention relates to improved method of obtaining (meth)acrylic ester including stage of etherification of (meth)acrylic acid with C1-C4alcohol in presence of catalyst from highly acidic cation-exchange resin in form of immovable layer for obtaining (meth)acrylic ester; addition of polymerisation inhibitor into reactor or into distillation column for isolation; stage of isolation, at which (meth)acrylic acid that did not react is separated from reaction solution, obtained at reaction stage, where temperature in distillation column still is in the range from 60 to 100°C, and pressure at the top of distillation column is in the range from 1.33 to 26.7 kPa; and recirculation stage in order to return thus obtained (meth)acrylic acid, that did not react, to reaction stage, where solid substances, contained in isolated (meth)acrylic acid that did not react and is returned to reaction stage, are isolated from it. In industry used method of obtaining (meth)acrylic esters is improved in such way as to prolong service life of used in it catalyst from highly acidic cation-exchange resin.

EFFECT: elaboration of improved method of obtaining (meth)acrylic ester.

5 cl, 2 ex, 1 dwg

FIELD: chemistry.

SUBSTANCE: raw material composition based on fatty acids or esters of fatty acids, obtained by hydrolysis of oil from seeds or by re-etherification of oil from seeds with C1-8-alkanol, contains more than 70 wt % of unsaturated fatty oleic acid, and less than 1.5 milliequivalents of admixture(s), poisoning methathesis catalyst, per kilogram of composition, after purification with adsorbent. Admixture contains one or more organic hydroperoxides. Method of olefin methathesis lies in contacting of raw composition, obtained from seed oil and containing one or more unsaturated fatty acids or esters of unsaturated fatty acids, with lower olefin in presence of catalyst based on phosphororganic transition metal complex. Used raw material composition contains less than 25 milliequivalents of admixture(s), poisoning methathesis catalyst, per kilogram of raw material composition, able to inhibit methathesis catalyst. As a result of reaction olefin with shortened chain and unsaturated acid or unsaturated ester with shortened chain is obtained. Method of obtaining complex polyether polyepoxide lies in carrying out the following stages. At the first stage raw material compositiojn, obtained from seed oil, containing one or more unsaturated fatty acids or esters of fatty acids, contacts with lower olefin in presence of olefin methathesis catalyst. Used raw material composition contains less than 25 milliequivalents of admixture(s), poisoning methathesis catalyst, per kilogram of composition. At the second stage (re)etherification of obtained unsaturated acid with shortened chain or unsaturated ester with shortened chain with polyol is carried out. At the third stage epoxidation of obtained complex polyether polyolefin is carried out with epoxidising agent optionally in presence of catalyst. Method of obtaining α,ω-oxoacid, complex α,ω-oxyester and/or α,ω-diol with shortened chain lies in carrying out the following stages. At the first stage raw material composition, obtained from seed oil, containing one or more unsaturated fatty acids or esters of fatty acids contacts with lower olefin in presence of olefin methathesis catalyst. Used raw material composition contains less than 25 milliequivalents of admixture(s), poisoning methathesis catalyst, per kilogram of composition. At the second stage hydroformilation is carried out with hydrating of obtained unsaturated acid or ester with shortened chain in presence of hydroformiolation/hydration catalyst.

EFFECT: increase of catalyst serviceability and obtaining chemical compounds with high productivity.

25 cl, 3 tbl, 12 ex

FIELD: biologically active substances.

SUBSTANCE: invention relates to improved method of obtaining total amount of phenol acid including following steps: (a) multi-rooted sage is extracted with water and filtered; (b) filtrate is placed in polyamide column and washed with water to neutral reaction, wash water is removed, and polyamide column is eluted with weak aqueous alkali solution, and obtained fractions are connected; (c) alkali fractions obtained in step (b) are acidified and placed in absorption column with macroporous resin, column is washed to neutral state, wash water is removed, column is eluted with aqueous or anhydrous lower alcohol, eluent is collected, evaporated at reduced pressure to remove alcohol, and dried. Yield of final product exceeds 4% based on amount of crude drug and content of total amount of phenol acid exceeds 80%. Thus obtained total amount of phenol acid can be used as drug for prevention and treatment of brain vessel diseases.

EFFECT: enlarged resource of vegetable material for preparation of vascular drugs.

15 cl, 7 ex

The invention relates to a method of separation of carboxylic acids or their methyl esters of high purity and can be used in various cleaning processes, the division and separation of carboxylic acids from different colored hydrocarbon mediums: oil, oil products, the dispersed organic matter of rocks, etc

FIELD: chemistry.

SUBSTANCE: invention relates to improved method of obtaining (meth)acrylic ester including stage of etherification of (meth)acrylic acid with C1-C4alcohol in presence of catalyst from highly acidic cation-exchange resin in form of immovable layer for obtaining (meth)acrylic ester; addition of polymerisation inhibitor into reactor or into distillation column for isolation; stage of isolation, at which (meth)acrylic acid that did not react is separated from reaction solution, obtained at reaction stage, where temperature in distillation column still is in the range from 60 to 100°C, and pressure at the top of distillation column is in the range from 1.33 to 26.7 kPa; and recirculation stage in order to return thus obtained (meth)acrylic acid, that did not react, to reaction stage, where solid substances, contained in isolated (meth)acrylic acid that did not react and is returned to reaction stage, are isolated from it. In industry used method of obtaining (meth)acrylic esters is improved in such way as to prolong service life of used in it catalyst from highly acidic cation-exchange resin.

EFFECT: elaboration of improved method of obtaining (meth)acrylic ester.

5 cl, 2 ex, 1 dwg

FIELD: chemistry.

SUBSTANCE: present invention pertains to improvement of the method of producing (met)acrylic acid and complex (met)acrylic esters, involving the following stages: (A) reacting propane, propylene or isobutylene and/or (met)acrolein with molecular oxygen or with a gas, containing molecular oxygen through gas-phase catalytic oxidation, obtaining crude (met)acrylic acid; (B) purification of the obtained crude (met)acrylic acid, obtaining a (met)acrylic acid product; and (C) reacting raw (met)acrylic acid with alcohol, obtaining complex (met)acrylic esters, in the event that the installation used in any of the stages (B) and (C), taking place concurrently, stops. The obtained excess crude (met)acrylic acid is temporarily stored in a tank. After restoring operation of the stopped installation, the crude (met)acrylic acid, stored in the tank, is fed into the installation, used in stage (B), and/or into the installation used in stage (C). (Met)acrylic acid output of the installation used in stage (A) should be less than total consumption of (met)acrylic acid by installations used in stages (B) and (C).

EFFECT: the method allows for processing (met)acrylic acid, temporarily stored in a tank, when stage (B) or (C) stops, without considerable change in workload in stage (A).

2 ex

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method, by which the carboxylic acid/diol mixture, that is suitable as the initial substance for the manufacture of polyester, obtained from the decolourised solution of carboxylic acid without actually isolating the solid dry carboxylic acid. More specifically, the invention relates to the method of manufacturing a mixture of carboxylic acid/diol, where the said method includes the addition of diol to the decolourised solution of carboxylic acid, which includes carboxylic acid and water, in the zone of the reactor etherification, where diol is located at a temperature sufficient for evaporating part of the water in order to become the basic suspending liquid with the formation of the specified carboxylic acid/diol mixture; where the said carboxylic acid and diol enter into a reaction in the zone of etherification with the formation of a flow of a complex hydroxyalkyl ether. The invention also relates to the following variants of the method: the method of manufacture of the carboxylic acid/diol mixture, where the said method includes the following stages: (a) mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of damp carboxylic acid; where the said carboxylic acid is selected from the group, which includes terephthalic acid, isophthatic acid, naphthalenedicarboxylic acid and their mixtures; (b) discolourisation of aforesaid solution of damp carboxylic acid in the zone for reaction obtaining the decolourised solution of carboxylic acid; (c) not necessarily, instantaneous evaporation of the said decolourised solution of carboxylic acid in the zone of instantaneous evaporation for the removal of part of the water from the decolourised solution of carboxylic acid; and (d) addition of diol to the decolourised solution of carboxylic acid in the zone of the reactor of the etherification, where the said diol is located at a temperature, sufficient for the evaporation of part of the water in order to become the basic suspending liquid with the formation of the carboxylic acid/diol mixture; where the aforesaid carboxylic acid and diol then enter the zone of etherification with the formation of the flow of complex hydroxyalkyl ether; and relates to the method of manufacture of carboxylic acid/diol, where the said method includes the following stages: (a) the mixing of the powder of damp carboxylic acid with water in the zone for mixing with the formation of the solution of carboxylic acid; (b) discolourisation of the said solution of damp carboxylic acid in the reactor core with the formation of the decolourised solution of carboxylic acid; (c) crystallisation of the said decolourised solution of carboxylic acid in the zone of crystallisation with the formation of an aqueous suspension; and (d) removal of part of the contaminated water in the aforesaid aqueous solution and addition of diol into the zone of the removal of liquid with the obtaining of the said carboxylic acid/diol mixture, where diol is located at a temperature sufficient for evaporating part of the contaminated water from the said aqueous suspension in order to become the basic suspending liquid.

EFFECT: obtaining mixture of carboxylic acid/diol.

29 cl, 4 dwg

Catalyst and method // 2316396

FIELD: organic synthesis and catalysts.

SUBSTANCE: invention relates to esterification method utilizing organotitanium or organozirconium catalyst and provides catalytic composition useful in preparation of esters, including polyesters, which contains (i) product of reaction between metal M alcoholate or condensed alcoholate selected from titanium, zirconium, and hafnium alcoholates, (ii) alcohols containing at least two hydroxy groups, (iii) 2-hydroxycarboxylic acid, and (iv) base, wherein molar ratio of base to hydroxycarboxylic acid is within the range between 0.01:1 and 0.79:1. Esterification reaction in presence of above catalyst is also described.

EFFECT: avoided yellowness in final product, raised temperature for the beginning of crystallization and crystallization temperature of polyester.

14 cl, 4 tbl, 20 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for synthesis of chlorine-substituted phenoxyacetic acid esters by the esterification reaction of corresponding acid with (C7-C9)-alcohol of normal structure of isomers, or in the combination. The esterification reaction is carried out in the mole ratio alcohol : acid = (1.1-1.75):1.0 by step-by-step increasing the temperature process. At the first step the process is carried out at the boiling point of azeotrope alcohol : water depending on the residual pressure value generated in the system for separation of the main mass of formed reaction water followed by increasing temperature by 20-60°C for the complete termination of the esterification reaction. The process can be carried out in the presence of catalytic amounts of mineral acids 0.01-0.03 wt.-% of the reaction mass. Invention provides high quality and high yield of the end product.

EFFECT: improved method of synthesis.

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to a method for synthesis of saturated aliphatic carboxylic acids with stable carbon isotopes (1-13C). Method involves the hydrocarboxylation reaction of α-olefins with carbon monoxide (13CO) and water at temperature 100-170°C and under pressure not exceeding 5 MPa in the presence of a solvent and catalytic system containing palladium compound as complex PdCl2(PPh3)2 and triphenylphosphine PPh3 taken in the ratio from 1:2 to 1:100, respectively. Synthesized carboxylic acids can be used as diagnostic test-preparations in medicine practice and in criminology, scientific investigations and in other fields. Invention provides synthesis of enanthic acid and caprylic acid labeled by stable carbon isotope 13C at position 1 for a single step, to increase yield of acids as measured for isotope raw, to decrease cost price of acids and to obtain derivatives of (1-13C)-caprylic acid - (1-13C0-caprylate sodium and (carboxy-13C)-trioctanoine.

EFFECT: improved methods of synthesis.

9 cl, 6 ex

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to the improved method for synthesis of carboxylic acid esters that are used as components of lacquered resins and components of paint-and varnish materials, especially, as plasticizer for plastics. Method involves interaction of di- or polycarboxylic acids or their anhydrides with alcohols wherein reaction water is removed by azeotropic distillation with alcohol, and liquid removed from reaction by azeotropic distillation is replaced with alcohol completely again. The improvement of periodic method used in synthesis of esters provides enhancing yield of the end product and reducing the reaction process time.

EFFECT: improved method of synthesis.

5 cl, 4 ex

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