Method for esterification of polyatomic alcohols with acids substituted with tertiary alkyls
SUBSTANCE: method involves reaction of a polyatomic alcohol - neopentyl glycol, trimethylol propane, pentaerythritol with trialkylacetic acid in molar ratio 1:1 in the presence of an acid catalyst which is a sulphonic acid derivative having pKa between -2 and +2, carried out at temperature 180°C or lower.
EFFECT: invention enables to obtain hydrolysis-resistant esters.
8 cl, 3 tbl, 15 ex
The present invention relates to a method for producing esters of polyols from tert-alkyl acid under reduced homopolymerization polyhydric alcohols. It is known that esters trialkylborane acids have high hydrolytic stability and enhance the hydrolytic stability present a number of complex ester. For this reason, they are highly appreciated in the coatings and/or target applications in the construction industry that require resistance to hydrolysis. This property is due to spatial difficulty due to trialkyltin group acid. Therefore, polyhydric alcohols, partially esterified trialkylborane acid, regarded as the elementary units in the synthesis of resins for coatings or applications in the construction industry.
Etherification of alcohol trialkylborane acid is difficult, and for this reason, this acid is even used as a catalyst to accelerate the esterification reaction is less complicated spatial acid with alcohol (WO 0144156).
The application of conventional esterification catalysts for the esterification of spatial hindered acid alcohol or polyhydric alcohol is known from Jour. Am. Oil. Chem. Soc., Vol 45, 5-10, January 1968, the conditions Used are, according to the authors, more stringent than for non-complicated question is rantenna acid or alcohol, and in the case of polyhydric alcohols worked with excess acid to achieve complete esterification of an alcohol functional groups.
Also known etherification strongly branched (spatial difficult) acids using non-traditional catalysts for esterification. The use of CHLOROSILANES (Bull. Chem. Soc. Jpn, 54, 1267-1268) is effective in the case of monosperma due to the formation of alkoxysilanes as the active ingredients. However, given the technology of application of this method for the partial esterification of polyols.
Of the above cited publications can be established that previous technological solutions has drawbacks, such as the use of expensive catalysts or the inability to use conditions to provide partial esterification of a polyhydric alcohol with the formation of mainly monoamino polyhydric alcohols with only small amounts of compounds of higher molecular weight, resulting from side reactions of esterification.
The way in which you can use the usual esterification catalysts to obtain mainly monoamino polyhydric alcohols, which are invaluable industry, because such a monomer is considered to be a valuable basic element for use in further synthesis resins.p> To date, the result of extensive research and experimentation it was unexpectedly found that the choice of certain conditions in combination with a specific catalyst makes possible the predominant formation of low-viscosity complex monoether with hydroxyl functional groups of the tert-alkyl carboxylic acids and polyhydric alcohols.
Suddenly, to date, been found that the use of derivatives of sulfonic acids in mild temperature conditions is an effective combination for the production of complex monoether polyhydric alcohol without significant formation of polyethers. These polyethers are unwanted homopolymer by-products and are considered to be the product of the reaction between an alcohol functional groups; this reaction is a competing reaction, if the esterification is slow or if alcohol is used in excess relative to the acid functional groups. The present invention provides a solution to the problems, i.e. improved selective obtaining of complex monoether of polyhydric alcohols and spatial difficult carboxylic acids.
Method for the above-mentioned selective esterification reaction is carried out in the presence of the tvii acidic catalyst at a temperature below 180°C.
Suitable polyhydric alcohols may be selected from ethylene glycol, propylene glycol, oligomers of glycols (n from 2 to 10), glycerol, neopentyl glycol, trimethylolpropane, pentaerythritol, and combinations thereof. The preferred polyhydric alcohol selected from ethylene glycol, neopentyl glycol, trimethylolpropane, pentaerythritol. Most preferred are neopentylglycol, trimethylolpropane.
Derived acid selected from acids of the General formula (I)
in which R1, R2independently are aliphatic alkyl radicals of from 1 to 10 carbon atoms, the total number of carbon atoms of the three radicals (CH3+R1+R2) is from 3 to 20, preferably from 3 to 13.
The acidic catalyst is selected from the derived sulfonic acids, such as methanesulfonate, econsultancy, triftormetilfullerenov, para-toluensulfonate, cellsurvival acid, and the preferred acid catalysts are methansulfonate acid or para-toluensulfonate acid. These acids are used in the range from 0.05 to 4 wt.% relative to the weight of the acid and a polyhydric alcohol. The preferred interval is from 0.10 to 2.5 wt.% from acid and a polyhydric alcohol. The most preferred catalyst is one which by methansulfonate acid.
Hydroxyl-containing ester obtained from the above-mentioned polyhydric alcohol and alanovoy acid of the formula (I)may further be used as basic units in obtaining polyester resin with improved chemical resistance.
Thus obtained resin are oligomers that can be used mainly in compositions for coatings, compositions for impregnation of fibres and as a lubricating oil.
Description of measurements and analytical methods
Measurement of strength at impact: ISO 6272-93 (E)
Measurement of the hardness of the decay time of the oscillations of the pendulum hardness according to könig): according to ISO 1522-73 (E) or DIN 53157
A brief description of the method of determining the resistance to methyl ethyl ketone (MEK)
Floor wipe with a piece of cotton wool soaked in MEK (using a pressure of about 2 kg). If the surface is wiped with a hundred times up and down with no signs of any damage, the coating is considered fully utverzhdennym. If after x double proteron MEK floor collapsed by the solid line going from top to bottom panels, the floor is considered destroyed after x double proteron IEC". Resistance to IEC was measured on hardened surfaces.
The viscosity of Newtonian systems using Brookfield viscometer: ISO 2555-89.
The invention posn what is more detail in the following examples, without limiting, however, the amount of data specific implementation options. All percentages are content by weight and all parts are parts by weight unless otherwise indicated.
Uses a 1 l round bottom glass reactor, equipped with anchor stirrer, stainless steel, thermocouple, reflux condenser Dean-stark and inlet for N2. The reactor was placed tert-alanovoy acid and polyhydric alcohol (see Tables 1 and 2 for compositions) with a molar ratio of acid/ethanol 1:1. The reaction is carried out in an atmosphere of N2with constant stirring and gradual heating. At 130°C add solvent (xylene) and the catalyst. The temperature was raised to
- 150°C when using trimethylhexanoic acid (V5)
- 170°C when using the neo-decanoas acid (V10)
(Versatic acid 10 from Resolution Performance Products).
Temperature constant support until the acid number reaches a constant value. At this point the reaction is stopped and the reaction mixture cooled down.
Below diagram shows the structure of the products, which were identified by GC-MS analysis (with ionization detection mode POS-C1) for examples based on trimethylolpropane (TSR) as a polyhydric alcohol. In the samples simple poly is Fira were not detected.
a pair of toluensulfonate (pTSA)
methansulfonate acid (MSA 70% in water).
Mass %, are presented below in Tables for MSA, refer to the weight of the delivered solution.
pTSA was supplied in the form of solids, 97.5%, from Acros
MSA was supplied in the form of a solution (70% in water) from Atofina.
Polyhydric alcohol came:
trimethylolpropane (TSR) 97%, Aldrich
neopentylglycol (NPG) 99%, Aldrich
pentaerythritol 98%, Aldrich
Examples trimethylhexanoic acid (V5)
|The molar ratio of alcohol/acid||1/1||1/1||1/1||1/1||1/1||1/1||1/1||1/1|
|the concentration is not carried out; * yield based on unreacted acid (consumption of catalyst: all expressed in mass of the total mass of the acid and a polyhydric alcohol)|
Examples of Versatic acid 10 (V10)
Example 12. Polyester resin derived from a complex ester of a polyhydric alcohol obtained in example 6
Used a 1 l round bottom glass reactor, equipped with anchor stirrer, stainless steel, thermocouple, reflux condenser and inlet for N2. The product from example 6 (of 177.8 g) and succinic anhydride (153,6 g) were placed in the reactor in a molar ratio of 1-1 (assuming that ideally, the structure of the adduct is a complex monoether). The mixture was heated with stirring to 105°C, approximately at a given temperature is the heat release and temperature increases is raised to 160°C.
These reaction conditions, save to reach an acid number of. Then the reaction mixture was cooled to about 140°C, before added Cardura E10 (401 g), the temperature was maintained constant within 1 hour.
Properties of polyester resin:
Color (Pt/Co): 130
Viscosity: 12 to 690 MPa·s
The coating composition
The cross-linking agent Cymel 301 from CYTEC.
The curing catalyst: pTSA is used in the form of a 40% solution in butanol, the concentration of 1 wt.% of the total number.
Attitude: polyester 12/Cymel=80/20.
The conditions of curing the coated Q panel: 30 min 140°C.
Coating: 60 to 65 microns.
Properties of the coating: the strength of direct/reverse impact>WIM×lb
Poor penetration 9 mm
Resistance to IEC>100 double proteron (MEK=methyl)
Examples 13 and 14. The polyester obtained from trimethylhexanoic acid, a polyhydric alcohol, and other acid or anhydride.
Polyesters with compositions shown in Table 3, were obtained in a glass reactor, equipped with stirrer, heater/fridge and a nozzle Dean-stark. All the ingredients were heated to 160-200°C to achieve the desired acid number. To remove the reaction water by azeotropic distillation used xylene.
|Ingredients||Example 13||Example 14|
|Methylhexahydrophthalic anhydride (mol)||1||1|
|The amount of catalyst||0.02 wt.%||0.02 wt.%|
|The content HE %||6,8||5,1|
|(V5): trimethylhexane acid|
Example 15. Coating based on polyester 14
Estimated polyester 14 as a reaction solvent for the isocyanate cured coating. At first it was mixed with 40 wt.% with acrylic polyhydric alcohol. As the hardener used Desmodur N3600, aliphatic isocyanate of the Bayer; the catalyst was a mixture of dibutylamine of dilaurate and 1,4-diazabicyclo-2,2,2-octane; the system was diluted with butyl acetate to 100 MPa·S.
This system was compared with a similar coating composition prepared from acrylic polyhydric alcohol without polyester. A mixture containing 40%, had a much less volatile organic compounds (VOC)than the material for comparison (400 against 458 g/l), but showed excellent speed of solidification and appearance. After less than 30 minutes at 60°C. the system was slipnoose.
1. The method of obtaining esters, polyhydric alcohol and tert-alanovoy acid, comprising the reaction of a specified polyhydric alcohol and specified alanovoy carboxylic acid in a molar ratio of 1:1 in the presence of acidic catalyst comprising a derivative of sulfonic acid having a pKa ranging from -2 to +2, carried out at a temperature below 180°C and, if necessary, in the presence of an inert organic solvent.
2. The method according to claim 1, where the acid catalyst is selected from methansulfonate, econsultancy, triftormetilfullerenov, para-toluensulfonate, cellsurvival acids.
3. The method according to claim 1, where the acid catalyst is methanesulfonate or para-toluensulfonate acid.
4. The method according to claim 1, where the acid catalyst is used in the range from 0.05 to 4 wt.%, p is edocfile from 0.10 to 2.5 wt.% relative to the weight of the acid and a polyhydric alcohol.
5. The method according to claim 1, characterized in that the derived acid selected from acids of the General formula (I),
in which R1, R2independently are aliphatic alkyl radicals of from 1 to 10 carbon atoms, the total number of carbon atoms of the three radicals (CH3+R1+R2) is from 3 to 20, preferably from 3 to 13.
6. The method according to claim 1, characterized in that the polyhydric alcohol may be selected from ethylene glycol, propylene glycol, oligomer glycol (with n from 2 to 10), glycerol, neopentyl glycol, trimethylolpropane, pentaerythritol, and combinations thereof, preferably neopentyl glycol, trimethylolpropane, pentaerythritol.
7. The resin obtained from the complex ester obtained according to any one of claims 1 to 6.
8. The coating composition containing utverzhdennuyu the resin composition according to claim 7.
SUBSTANCE: invention relates to a method for thermal treatment of polyester granules for fractional crystallisation, where molten polyester is fed into an underwater granulation system and granulates. The obtained granulated material is loaded at a short distance from the underwater granulation system into a device for separating the water/solid phase. The dried granulated material is fed into a treatment apparatus without supply or external energy or heat at temperature above 100°C, and thermal treatment for fractional crystallisation takes place due to inherent heat of the granulated material. The treatment apparatus is made in form of reactor which at least inclined, in which the granulated material is fed at temperature above 100°C, passes through it from the loading point to the discharge point under the effect of its own weight and comes out at temperature above 130°C.
EFFECT: disclosed thermal treatment method simplifies the process of fractional crystallisation owing to use of inherent heat of the granules.
7 cl, 2 dwg
SUBSTANCE: aqueous medium contains A) one or more water-diluted polyester polyols with hydroxyl number ranging from 20 to 300 mg KOH/g and acid number from 20 to 80 mg KOH/g B) one or more cross linking agents which are active towards OH groups, C) water, D) neutralising agent, and can also contain solvents, auxiliary agents and additives.
EFFECT: good adhesion to metals and high resistance to aggressive media.
13 cl, 4 ex, 2 tbl
SUBSTANCE: described is an agent for processing oil, containing polyester, obtained from reacting an anionic monomer of a dicarboxylic acid or its anhydride with polytetrahydrofuran or poly(ethyleneglycol)-block-poly(propyleneglycol)-block-poly(ethyleneglycol). Described also is a method of processing oil using an effective amount of the said polyester.
EFFECT: higher degree of oil dehydration compared to known levels.
18 cl, 3 tbl, 6 ex
SUBSTANCE: invention relates to field of processing plastics, in particular to additive for processing polyolefins, which represents monoepoxyester of diane resin with molecular weight from 4000-4500 units and carboxylic acid - abietene, benzoic or salicylic. Obtained additive can be used as 100% product or in form of concentrate of said monoepoxyester in polyethylene with content of basic substance 10-20%.
EFFECT: increase of polyolefin melt index and 20-25°C reduction of processing temperature per each per cent of additive.
3 cl, 2 tbl, 6 ex
SUBSTANCE: invention refers to method for making bulk, high resilience slabstock or moulded foam, used for upholstery, automobile seats and panel cushions, for packing, other applications to softening and energy management, for sealing and other applications. The presented method involves as follows. Organic polyisocyanate contacts with polyol compound containing high mass equivalent polyol or mixed polyols with foaming agent, gelling catalyst and surface-active substance added. At least 10 wt % of high mass equivalent polyol (polyols) represent one or more equivalent mass hydoxymethyl-containing polyesterpolyols at least 400 up to 15000 produced by interaction of hydoxymethyl group containing fatty acid with 12-26 carbon or this acid ester atoms and compound initiator polyol or polyamine, thereby polyesterpolyol contains as follows: [H-X](n-p)-R-[X-Z]p, where R is residual compound initiator, X is independent, -O-, -NH- or -NR'-, while Z- represents linear or branched chain containing one or more groups A, independently chosen of groups A1, A2, A3, A4 and A5, expressed by formulas (II), (III), (IV), (V) and (VI), respectively. Besides there is disclosed polyurethane foam made by the declared method. Declared method ensures making polyurethane foams with using polyol from renewable source.
EFFECT: improved UV resistance and heat stability, and improved gas-invoked discoloring resistance.
9 cl, 8 tbl, 41 ex
SUBSTANCE: mixture consists of polyols expressed by compositions and . Besides there is disclosed method for producing mixed polyols including (i) mixing of the initiator representing polyol, polyamine, amino alcohol or their mixture, and monomer of at least one formula , and , herewith amount of composition (III) is at least 0.05 wt % of mixed polyols and (ii) heating of the mixture to reaction temperature, during reaction time, in vacuum and with the catalyst added, and method for making mixed polyols, including (i) heating with the catalyst added, of monomer described by least one formula (I), (II) and (III), and amount of composition (III) is at least 0.05 wt % of mixed polyols until some monomers react, and then (ii) adding of the initiator during time and at temperature sufficient to produce mixed polyols in vacuum environment, as well as polyurethane containing interaction product of polyisocyanate and specified mixed polyols.
EFFECT: mixed polyols are characterised with high molecular weight without gelling, application of such mixed polyols in foamed polyurethanes production improves pore size of foam plastics, pore structure, touch perception or tactile quality and its wear resistance.
32 cl, 19 tbl, 67 ex, 3 dwg
FIELD: organic chemistry, polymers, chemical technology.
SUBSTANCE: invention relates to a method for synthesis of complex polyesters that are used in synthesis of polyurethanes. Invention proposes a method for synthesis of complex polyesters by the polycondensation reaction of phthalic anhydride and diethylene glycol in the molar ratio = 1:(1.2-2.5) at temperature 205 ± 5°C or adipic acid and ethylene glycol in the molar ratio = 1:(1.5-1.6) at 195 ± 5°C, or adipic acid, ethylene glycol and 1,4-butanediol in the molar ratio = 1:(0.42-0.78) at 200 ± 5°C to acid number value 35-42 mg KOH/h followed by addition to the reaction mixture tetrabutoxytitanium as a catalyst and vacuum condensation is carried out to acid number value 1 mg KOH/g, not above. Proposed methods require by 1.4-2-fold less time as compared with the known ones and provide significant reducing energy consumption.
EFFECT: simplified method for synthesis of complex polyesters for polyurethanes.
3 cl, 1 tbl, 7 ex
FIELD: organic chemistry of polymers, chemical technology.
SUBSTANCE: invention relates to a method for preparing cross-linked polymers of enhanced resistance to heat. Invention proposes polyester synthesized by using glycerol - an organic base with functionality value f = 3 and organic acid as the parent components and comprising additionally an organic base with value f ≥ 3 - triethanolamine or polyethylenepolyamine. As an organic acid method involves using adipic acid with value f = 2, or tartaric acid with value f = 2, or citric acid with value f = 3 in the following ratio of components, wt.-%: glycerol, 10-17; triethanolamine or polyethylenepolyamine, 17-32; adipic, tartaric or citric acid, 58-66; f means amount of reactive functional groups of basic and acid type in each molecule of the component. Method for preparing polyester involves carrying out synthesis at increased temperature from the parent components and hardening stage in a single reaction volume simultaneously. Invention provides enhancing resistance to heat of material and decreasing consumptions for its preparing.
EFFECT: improved preparing method.
2 cl, 1 tbl, 9 ex
SUBSTANCE: invention relates to an improved method of producing dialkyl ether of naphthalene dicarboxylic acid used in production of different polymer materials such as polyesters or polyamides from a liquid-phase reaction mixture containing low-molecular alcohol, naphthalene dicarboxylic acid, and material which contains polyethylene naphthalate, in mass ratio of alcohol to acid between 1:1 and 10:1, at temperature between 260°C and 370°C and pressure between 5 and 250 absolute atmospheres.
EFFECT: method enables production of highly pure NDC.
6 cl, 2 ex
SUBSTANCE: method of regioselective obtainment of 1-R1-2-R2-3-acetyl-glycerol derivative of the Formula 1 involves the following stages: Obtainment of 1-R1-3-(protective group)-glycerol of Formula 3 by adding protective group to 3rd position in 1-R1-glycerol of Formula 2; obtainment of 1-R1-2-R2-3-(protective group)-glycerol of Formula 4 by adding R2 group to 2nd position of 1-R1-3-(protective group)-glycerol of Formula 3, where R2 group is added by reaction of R2-OH with 1-R1-3-(protective group)-glycerol in the presence of aprotic organic solvent, catalyst and dehydrating medium; aprotic organic solvent is selected out of group consisting of hexane, heptane, dichloromethane, ethyl acetate, tetrahydrofuran and mixes thereof; dimethylaminopyridine is catalyst; and dicyclohexylcarbodiimide is dehydration medium; simultaneous removal of protective group and acetylation of 1-R1-2-R2-3-(protective group)-glycerol of Formula 4, where protective group removal reaction and acetylation reaction are performed using Lewis acid and acetic anhydride or using acetylation agent; Lewis acid is selected out of group including zink chloride (ZnC2), tin chloride (SnCl2), boron trifluoride diethyl ether (BF3Et2O) and mixes thereof; acetylation agent is selected out of group including acetylchloride, acetylbromide and mixes thereof, where compounds of Formulae 1-4 are racemic or optically active; R1 is palmitic acid group, R2 is linoleic acid group; P is trityl or trialkylsilyl as protective group; alkyl in trialkylsilyl is an alkylic group containing 1-5 carbon atoms, so that if the protective group is trityl then 1-R1-3-(protective group)-glycerol is obtained in the presence of pyridine solvent at 40-60°C or in the presence of nonpolar aprotic organic solvent and organic base within 0°C to room temperature range; nonpolar aprotic organic solvent is selected out of group including pyridine, dichloromethane, tetrahydrofuran, ethyl acetate and mixes thereof; organic base is selected out of group including triethylamine, tributylamine, 1,8-diazabicyclo[5,4,0]-7-undecene (DBU) and mixes thereof, and if the protective group is trialkylsilyl then 1-R1-3-(protective group)-glycerol is obtained in the presence of aprotic organic solvent and organic base within 0°C to room temperature range; aprotic organic solvent is selected out of group including dichloromethane, tetrahydrofuran, ethyl acetate, dimethylformamide and mixes thereof; and organic base is selected out of group including imidazole, triethylamine, and mixes thereof. [Formula 1] , [Formula 2] , [Formula 3] , [Formula 4] .
EFFECT: obtainment of glycerol derivative with high efficiency and output.
8 cl, 10 ex
SUBSTANCE: invention relates to an improved method of regenerating surfactants based on fluorinated acids or their salt from adsorbent particles on which the said surfactants are adsorbed, based on fluorinated acids, involving saturation of adsorbing particles with surfactants based on fluorinated acids or their salt, washing particles of adsorbent on which the surfactant based on fluorinated acid or its salt is adsorbed with water; mixing particles of the adsorbent on which the surfactant based on fluorinated acid or its salt is adsorbed with alcohol or inorganic acid in the presence of water, initiation of etherification of the said surfactant based on fluorinated acid or its salt with the said alcohol to obtain an ether derivative of the said fluorinated surfactant, distillation of the said mixture to obtain a distillate containing the said ether derivative, separation of the said ether derivative from the said distillate and optional return of the remaining distillate to the said mixture and optional conversion of the said ether derivative to the corresponding surfactant based on fluorinated acid or its salt.
EFFECT: efficient method enables use of minimal amount of regenerating liquid and leads to obtaining regenerated particles of adsorbent which can be used repeatedly.
8 cl, 18 ex
SUBSTANCE: invention relates to an improved method of producing butylacrylate involving: reaction of acrylic acid with butanol in the presence of water and a catalyst in a reactor; where the starting material is an aqueous solution of acrylic acid which is at least one of: (1) condensed water, obtained from vapour used in a kinetic vacuum pump which transports gas after trapping fluid process medium- vapour which is blown at high speed, (2) water for hydraulic sealing in a liquid ring pump which isolates liquid-water after air is let into the housing, (3) water used for collecting acrylic acid in the device which collects acrylic acid from an acrylic acid-containing gas, and acrylic acid which is not present in the aqueous solution of acrylic acid, where the device used for collecting acrylic acid is one or more devices selected from a group comprising a packed column, a plate-type column, a spray column and a scrubber. The invention also relates to a method of producing a super-absorbing polymer based on acrylic acid, involving the following steps: polymerisation of acrylic acid, in which the aqueous phase used is an emulsified aqueous solution of an acrylic acid monomer and water, dehydration of the obtained mixture during azerotropic distillation, where the starting material is aqueous acrylic acid solution which is at least one of the following: condensed water obtained from vapour used in a kinetic vacuum pump which transports gas after trapping fluid process medium - vapour, which is blown at high speed, water for hydraulic sealing in a liquid ring pump which isolates liquid-water after air is let into the housing, water used for collecting acrylic acid in the device which collects acrylic acid from an acrylic acid-containing gas, and acrylic acid which is not present in the aqueous solution of acrylic acid, where the device used for collecting acrylic acid is one or more devices selected from a group comprising a packed column, a plate-type column, a spray column and a scrubber.
EFFECT: design of an efficient method of using aqueous solution of (meth)acrylic acid with low concentration, formed at the stage for producing/storing (meth)acrylic acid.
13 cl, 2 ex
SUBSTANCE: invention relates to organic synthesis, specifically to a method of producing methyl formate, which is used as an intermediate product during synthesis of organic acids such as formic acid, acetic acid, propionic acid and esters thereof, as well as an additive to diesel fuel. The method of producing methyl formate from a gas which contains a mixture of carbon oxide and hydrogen involves treating the mixture of hydrogen and carbon oxide with alkali with formation of an alkali metal formate and purified hydrogen. The obtained alkali metal formate is then dissolved in water and treated with sulphuric acid with formation of formic acid, while separating sulphur impurities, and the formic acid is reduced to methanol with hydrogen using a hydrogenation catalyst. The formic acid is reduced until conversion of 50-90 mol %. The cooled mixture of methanol and formic acid is rectified in the presence of an acid catalyst, while esterifying the reaction to methyl formate.
EFFECT: increased output of high-quality end product while using material with various degree of purity.
7 cl, 2 ex
SUBSTANCE: present invention refers to the method for preparation of aloe-emodin, and rein or diacerein used for treatment of the diseases concerned with anomalous dystrophy of connective tissues. The method for preparation of aloe-emodin includes oxidation of aloin dissolved in the polyatomic alcohol with oxygen-containing gas in the presence of acid. The method for preparation of rein or diacerein includes the following stages: a) oxidation of aloin dissolved in the polyatomic alcohol with oxygen-containing gas in the presence of acid to aloe-emodin; b) oxidation of aloe-emodin with chrome-free oxidising media to rein; c) purification of the rein obtained on the stage b) and d) optional acetylation of the rein obtained on the stage c) with acetylation agent to diacerein. The claimed method allows obtaining of aloe-emodin with good yield and purity level without using of toxic or harmful substances and complicated purification methods.
EFFECT: claimed method allows also diacerein obtaining without using of hexavalent; chrome as oxidiser and without complicated purification methods.
17 cl, 1 tbl, 5 ex
SUBSTANCE: invention concerns organic compound synthesis, particularly method of obtaining 4-biphenylmetacrylate of the formula . Obtained compound is applied in production of heat and weather resistant polymer materials. Claimed method involves dissolution of 4-phenylphenol in 10 wt % aqueous solution of caustic soda, further dosage of acylating agent in the form of metacrylic acid anhydride agent in reaction mix preliminarily cooled to 0-(+5°)C at such rate so as to keep the mix temperature below +10°C at molar ratio of 4-phenylphenol and metacrylic acid anhydride of 1:(1.1-1.5), reaction mix maturing at room temperature with stirring, organic layer extraction, flushing by alkali solution, and drying.
EFFECT: enhanced output of 4-biphenylmetacrylate, admixture content of non-reacted 4-phenylphenol reduced to 0,003-0,005 wt %.
3 cl, 1 tbl, 10 ex
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
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
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).
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to the improved method for preparing dimethyl-1,5-naphthalene dicarboxylate that is used in preparing polymers based on thereof and articles made of these polymers. The economic and effective method involves the following stages: (1) dehydrogenation of 1,5-dimethyltetraline to yield 1,5-dimethylnaphthalene; (2) oxidation of 1,5-dimethylnaphthalene prepared at dehydrogenation stage to yield 1,5-naphthalene dicarboxylic acid being without accompanying isomerization stage, and (3) esterification of 1,5-naphthalene dicarboxylic acid prepared at oxidation stage in the presence of methanol to yield the final dimethyl-1,5-naphthalene dicarboxylate.
EFFECT: improved preparing method.
9 cl, 3 dwg, 5 ex