RU2523800C1 - Method of producing catalyst for synthesis of oligo- and polyethylene terephthalates and method of producing oligo- and polyethylene terephthalates - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method of producing catalyst includes treating antimony trioxide with a polyfluorinated alcohol selected from 1,1,3-trihydroperfluoropropanol-1, 1,1,5-trihydroperfluoropentanol-1, 1,1,7-trihydroperfluoroheptanol-1 and 1,1,9-trihydroperfluorononanol-1, in molar ratio of 1:6, respectively, at temperature of 180°C, ultrasonic frequency of 40 kHz for 6 hours. The method of producing oligo- and polyethylene terephthalates is carried out by polycondensation of terephthalic acid and ethylene glycol while heating in the presence of the obtained catalyst.

EFFECT: obtaining a catalyst for synthesis of oligo- and polyethylene terephthalates characterised by avoiding the need to use auxiliary ingredients and additives, fewer secondary processes, and obtaining oligo- and polyethylene terephthalates in the presence of a catalyst with easy separation of the catalyst from the reaction products and high degree of polymerisation of the obtained product.

2 cl, 1 tbl, 1 ex

Description

The invention relates to a method for producing a catalyst for producing a polyester and a method for producing oligo- and polyethylene terephthalates, which can be used in the future to obtain fibrous, film, and injection compositions with enhanced hydrolytic and thermal stability.

; M - простой или комплексный ион металла, одно-, двух-, трех- или четырехвалентный, либо органический ион; А-P, S, B, Si, As или C, в этом случае R - перфторалкильная группа; R, R, R - одинаковые или отличающиеся друг от друга радикалы, содержащие до 20 атомов углерода, выбираемые из алкилов или арилов, линейных или разветвленных, насыщенных циклических или ароматических; m=0, 1 или 2; y≥1; x≥0) (Заявка RU 96110417, МПК C08F 4/00, опубл. 27.09.1998):A known catalytic system for producing polyethylene terephthalate by polymerization of bis (2-hydroxyethyl) terephthalate or its homologous oligomers, including a compound of the formula or its anhydride (Z-OH, OM, OR ^/ , $$\text{A.}N\text{A.}{R}_2^{//}$$

; M is a simple or complex metal ion, one-, two-, three- or tetravalent, or an organic ion; AP, S, B, Si, As or C, in which case R is a perfluoroalkyl group; R, R, R are the same or different from each other radicals containing up to 20 carbon atoms, selected from alkyl or aryl, linear or branched, saturated cyclic or aromatic; m is 0, 1 or 2; y≥1; x≥0) (Application RU 96110417, IPC C08F 4/00, publ. 09/27/1998):

Z _X -A (O) _m -R _y

and one of the derivatives of antimony or germanium, taken in such quantities that the content of antimony or germanium in the final polymer is from 5 to 130 ppm.

The disadvantage of using the developed catalytic system is the inaccessibility of the compounds used and the lack of data on their thermal stability.

Fluorine-containing catalysts for the polycondensation of terephthalic acid and ethylene glycol are known, including fluorides of lead, cobalt, manganese and magnesium, as well as tantalum hexafluoride (Petukhov BV Polyester fibers. M: Chemistry, 1976, p.60).

The disadvantage of using these catalysts is their inaccessibility and the possibility of partial hydrolysis with moisture present in ethylene glycol.

A known catalyst for solid-phase polymerization of polyester for resins with a low formation of acetaldehyde, comprising the step of polycondensing the polyester resin in the presence of a tin compound in an amount of from 50 to 120 ppm and an antimony compound in an amount of from 95 ppm to 300 ppm of the polyester resin and the stage of solid-state polymerization of the polyester resin for a time sufficient to increase the characteristic viscosity of the resin by at least 0.15 dl / g (Pat. RU 2428437, IPC C08G 63/85, C08G 63/80, C08F 4 / 16, C08F 4/20, publ. 09/10/2011).

The disadvantage of this method of producing a complex polyester resin is a wide molecular weight distribution, and the catalyst composition itself is characterized by inaccessibility and multicomponent composition.

Known polycondensation using a catalyst and a catalyst activator to obtain a polyester (Application RU 2002100706, IPC C08G 63/82, B01J 21/06, B01J 31/04, B01J 31/18, publ. 10.12.2003). The catalyst composition used contains titanyl oxalate and a catalyst activator containing oxalic or carboxylic acid or their corresponding salt.

The disadvantage of the used catalyst is its inaccessibility and multicomponent composition.

A known method of producing complex polyesters and copolyesters in the presence of a titanium-containing catalyst in the form of a precipitate of titanium dioxide and silicon dioxide (Pat. RU 2151779, IPC C08G 63/85, C08G 63/87, publ. 27.06.2000).

The disadvantage of this method is the complexity of the preparation of the catalyst, its variable composition, the complexity of separating the catalyst from polyester.

A known method of producing polyethylene terephthalate, including heating dimethyl terephthalate and ethylene glycol in the presence of a catalyst - spirodibutoxybisboroxy titanate and the reaction product of phosphoric and boric acid (Pat. RU 2050376, IPC C08G 63/85, publ. 20.12.1995).

The disadvantage of this method is the inaccessibility and multicomponent composition of the catalyst and the complexity of its separation from polyethylene terephthalate.

A known catalyst for producing polyester, a method for producing polyester and copolyester, in which the catalyst is a solid titanium compound containing titanium, oxygen, hydrogen and having a Ti-O bond or titanium-containing solution, in which the product of a titanium halide hydrolyzate or titanium alcoholate hydrolyzate with a polyhydric alcohol dissolved in ethylene glycol in an amount of from 3000 to 100000 ppm in terms of titanium atoms (Pat. RU No. 2237068, publ. 09/27/2004).

The disadvantages of this method are the difficulties in the preparation of the catalyst for the production of polyethylene terephthalate, including the stages of cooling, dosing aqueous ammonia and maintaining the desired pH value of the medium, and the method of producing polyester and copolyester is characterized by the difficulty of achieving a high degree of conversion of the starting reagents.

The closest is a polycondensation catalyst for producing a polyester and a method for producing a polyester using a polycondensation catalyst (Pat. RU 2418817, IPC C08G 63/12, C08G 63/181, C08G 63/78, C08G 63/82, C08G 63/85, B01J 21/06, published on 05/20/2011). The catalyst contains solid base particles having a titanic acid coating layer on their surfaces in an amount of from 0.1 to 50 parts by weight, calculated on titanium dioxide, per 100 parts by weight of the solid base. A method for producing a polyester is to carry out the esterification of glycol with a dicarboxylic acid in the presence of a polycondensation catalyst.

The disadvantage of this method is the complexity of the preparation of the catalyst and its multicomponent composition, and the polymer obtained in this way contains a difficult to separate catalyst, which complicates its further use in the food and cosmetic industry.

Objective: the development of technological methods for producing a catalyst for the synthesis of oligo- and polyethylene terephthalates.

The technical result of the proposed method is the possibility of technologically producing a catalyst for the synthesis of oligo- and polyethylene terephthalates, characterized by the absence of the need to use auxiliary ingredients and additives (solvents, buffer solutions, activators), as well as a decrease in the proportion of side processes.

The technical result of the proposed method is the possibility of technologically producing oligo- and polyethylene terephthalates in the presence of a catalyst, characterized by the possibility of easy separation of the catalyst from the reaction products and a high degree of polymerization of the obtained product.

The technical result according to claim 1 is achieved in a method for producing a catalyst for the synthesis of oligo- and polyethylene terephthalates of the general formula:

Sb (OCH ₂ (CF ₂ CF ₂ ) _n H) ₃ , n = 1-4

by treating the antimony trioxide with a polyfluorinated alcohol selected from the series 1,1,3-trihydroperfluoropropanol-1, 1,1,5-trihydroperfluoropentanol-1, 1,1,7-trihydroperfluoropentanol-1 and 1,1,9-trihydroperfluorononanol-1, at a molar ratio of 1: 6, respectively, at a temperature of 180 ° C, an ultrasound frequency of 40 kHz for 6 hours

The technical result according to claim 2 of the claims in a method for producing oligo- and polyethylene terephthalates is achieved by polycondensation of terephthalic acid and ethylene glycol by heating in the presence of a catalyst of the general formula:

The advantages of the catalyst preparation method are the industrial availability of antimony trioxide and polyfluorinated alcohols, the increased acidity of the latter (as compared to non-fluorinated), promotes the reaction of alcohol formation and the production of hydrolytically stable compounds.

The advantages of the method for producing oligo- and polyethylene terephthalates are the possibility of easy separation of the catalyst from the reaction products and a high degree of polymerization of the obtained product.

As polyfluorinated alcohol, 1,1,3-trihydroperfluoropropanol-1, 1,1,5-trihydroperfluoropentanol-1, 1,1,7-trihydroperfluoroheptanol-1 and 1,1,9-trihydroperfluorononanol-1 are used (TU 2421-151- 05807960-2005).

Use antimony trioxide with a basic substance content of 99.98% (TU 01 / 25.09.2003, DIN 50049 / 3.1B).

To obtain the polyester, terephthalic acid (TU 2477-012-00209421-2003) and ethylene glycol (TU 6-01-512-93) are used.

The catalyst preparation temperature of 180 ° C is optimal, since its increase above 180 ° C contributes to an increase in the proportion of resinous compounds due to the dehydrofluorination of polyfluorinated alcohol, which complicates the isolation and purification of the reaction product. In turn, a decrease in temperature below 180 ° C reduces the degree of conversion of the starting reagents.

The molar ratio of antimony trioxide and polyfluorinated alcohol, 1: 6, is optimal, since a decrease or, conversely, an increase in the content of the amount of reagents violates the stoichiometric composition, which leads to difficulty in the isolation and identification of reaction products.

The reaction to obtain a catalyst at an ultrasound frequency of 40 kHz promotes homogenization of the solution. An increase in the frequency of ultrasound above 40 kHz or, conversely, less than 40 kHz does not have a positive effect on increasing the degree of conversion of polyfluorinated alcohol.

A treatment time of antimony trioxide with polyfluorinated alcohol of 6 hours is also optimal, since a reduction in the reaction time of less than 6 hours helps to reduce the degree of conversion of the starting reagents. Increasing the reaction time over 6 hours contributes to a side reaction of dehydrofluorination.

The claimed method is as follows.

Antimony trioxide and polyfluorinated alcohol are placed in the flask, heated to 180 ° C and incubated for 6 hours at an ultrasound frequency of 40 kHz, then the resulting product is separated, washed and dried.

The method for producing the polycondensation catalyst of terephthalic acid and ethylene glycol is illustrated by the following example.

Example. 1.0 g (3.42 · 10 ^-3 mol) of antimony trioxide and 0.88 g (2.05-10 ^-3 ) are placed in a glass reactor equipped with a tap with an attached refrigerator and a receiving flask to drain the water released during the reaction. mol) of polyfluorinated alcohol. The flask was thermostated at 180 ° C for 6 hours at an ultrasound frequency of 40 kHz. The resulting reaction product was separated, washed with ethanol and diethyl ether, and dried over anhydrous calcium chloride.

The interaction of 1,1,3-trihydroperfluoropropanol-1 with antimony trioxide produces antimony tris- (1,1,3-trihydroperfluoropropoxide) antimony, n = 1. The pasty substance is white-pink. IR spectrum, ν, cm ^-1 : 2914-2986 (ν _CH ), 1168-1198 (CF).

The interaction of 1,1,5-trihydroperfluoropropanol-1 with antimony trioxide produces antimony tris- (1,1,5'-trihydroperfluoropentoxide) antimony, n = 2. The pasty substance is white-pink. IR spectrum, ν, cm ^-1 : 2926-2990 (ν _CH ), 1170-1176 (CF).

The interaction of 1,1,7-trihydroperfluoroheptanol-1 with antimony trioxide produces antimony tris- (1,1,7-trihydroperfluoroheptoxide) antimony, n = 3. The pasty substance is white-pink. IR spectrum, ν, cm ^-1 : 2926-2990 (ν _CH ), 1170-1176 (CF).

The interaction of 1,1,9-trihydroperfluorononanol-1 with antimony trioxide produces antimony tris- (1,1,9-trihydroperfluorononoxide), n = 4. The pasty substance is white-pink. IR spectrum, ν, cm ^-1 : 2921-2998 (ν _CH ), П71-1183 (CF).

The polycondensation reaction of terephthalic acid with ethylene glycol in the presence of the obtained catalysts made it possible to establish that with an increase in the degree of telomerization n, a decrease in the fraction of the high molecular weight fraction in the mixture of oligo- and polyethylene terephthalates is observed (table).

Table The influence of the chemical structure of the catalyst on the degree of conversion of ethylene glycol and the composition of the reaction products Catalyst The degree of conversion of terephthalic acid,% The composition of the products of the polycondensation reaction,% wt. m = 1 m = 2 m = 3 m = 4-100 Sb (OCH ₂ CF ₂ CF ₂ H) ₃ 64 10 12 twenty 58 Sb (OCH ₂ (CF ₂ CF ₂ ) ₂ H) ₃ 51 7 19 26 48 Sb (OCH ₂ (CF ₂ CF ₂ ) ₃ H) ₃ 46 28 19 17 36 Sb (OCH ₂ (CF ₂ CF ₂ ) ₄ H) ₃ 32 41 thirty 17 22

The temperature for producing oligo- and polyethylene terephthalates is 280 ° C.

The molar ratio of terephthalic acid, ethylene glycol and catalyst is 1: 2.5: 10 ^-3 . With a decrease or, conversely, with an increase in the content of the number of reagents, the stoichiometric composition is violated, which leads to difficulty in the isolation and identification of reaction products.

The reaction time for the production of oligo- and polyethylene terephthalates is 2 hours, which allows to obtain a product with a polymerization degree m = 4-100.

The method of synthesis of oligo- and polyethylene terephthalates is illustrated by the following example.

Example. 100 g of terephthalic acid (1 mol), 90 g of ethylene glycol (2.5 mol), 0.05 g of catalyst (10 ^-3 mol) are mixed in a polycondensation flask, then the temperature is slowly raised to 280 ° C and the reaction mass is maintained for 2 h, sequentially driving off ethylene glycol released during polycondensation. After cooling the reaction mass, it is subjected to fractionation. The product m = 1 is soluble in water at 60 ° C, the dimer m = 2 is soluble in water when boiled, the trimer m = 3 is soluble when boiled in a water-alcohol solution, and the product m = 4-100 is soluble in o-chlorophenol.

Bis (2-hydroxyethyl) terephthalate (m = 1). IR spectrum, ν, cm ^-1 : 3344-3212 (ν _OH ), 1712 (ν _{C = O} , ester). Mp 109-110 ° C.

Dimer (m = 2). IR spectrum, ν, cm ^-1 : 3351-3330 (ν _OH ), 1708 (ν _{C = O} , ester). Mp 173-175 ° C.

Trimer (m = 3). IR spectrum, ν, cm ^-1 : 3355-3347 (ν _OH ), 1711 (ν _{C = O} , ester). Mp 204-206 ° C

High molecular weight product (m = 4-100). IR spectrum, ν, cm ^-1 : 3350-3418 (ν _OH ), 1700 (ν _{C = O} , ester). Mp 252-263 ° C. Intrinsic viscosity 0.71 dl / g.

IR spectra of substances were recorded on a Nicolet-6700 IR Fourier spectrometer and a Specord-M82 spectrometer.

The melting points of the substances were determined on a Mettler Toledo MP50 instrument at a heating rate of 2 ° C / min.

The characteristic viscosity was measured using a Ubbelode glass capillary viscometer (type 1C according to ISO 3105) by dissolving a portion of the polymer in a phenol: tetrachloroethane solvent mixture (60:40 mass).

The degree of polymerization of the high molecular weight product was determined by acetylation with acetic anhydride in the presence of pyridine, followed by titration with alkali of the precipitated acetic acid.

Thus, technological methods have been developed: producing a catalyst for the synthesis of oligo- and polyethylene terephthalates, which allows one to obtain a hydrolytically stable polycondensation catalyst, which is easily separated from the reaction product and does not require additional use of solvents, buffer solutions, and activators; obtaining oligo- and polyethylene terephthalates in the presence of a catalyst, which allows to obtain a product with a high degree of polymerization and ease of separation of the catalyst from the reaction product.

Claims (2)

1. A method of producing a catalyst for the synthesis of oligo - and polyethylene terephthalates of the General formula:
Sb (OCH ₂ (CF ₂ CF ₂ ) _n H) _3, n = 1-4,
comprising treating the antimony trioxide with a polyfluorinated alcohol selected from the range of 1,1,3-trihydroperfluoropropanol-1, 1,1,5-trihydroperfluoropentanol-1, 1,1,7-trihydroperfluoropentanol-1 and 1,1,9-trihydroperfluorononanol-1, at a molar ratio of 1: 6, respectively, at a temperature of 180 ° C, an ultrasound frequency of 40 kHz for 6 hours 2. A method of producing oligo- and polyethylene terephthalates, including the polycondensation of terephthalic acid and ethylene glycol by heating in the presence of a catalyst, characterized in that they use a catalyst of the general formula:
Sb (OCH ₂ (CF ₂ CF ₂ ) _n H) ₃ , n = 1-4
according to claim 1.