JP2002241478A - Process for preparation of polyester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for preparing a polyester enabling efficient separation, recovery and recycling of a catalyst in a synthesis of a polyester. SOLUTION: A polyester is prepared by reacting an aryl diiodide, an aliphatic or aryl diol and carbon monoxide in the presence of a catalyst and an organic base. The process is preferably carried out in a solvent. The catalyst is a heterogeneous catalyst containing a metal selected from the group consisting of palladium, platinum, nickel and cobalt. Following the preparation of the polyester, the catalyst can be easily separated and efficiently recycled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] The present invention relates to a method for producing polyester. More particularly, the present invention relates to a process for preparing a polyester from an aromatic diiodide, an alkyl or aryl diol and carbon monoxide. More specifically, the present invention is a process for producing a polyester by contacting an aryl diiodide and an alkyl or aromatic diol with carbon monoxide in the presence of a catalyst, wherein the catalyst is recovered and further treated. Regarding how to be recycled.

BACKGROUND OF THE INVENTION Polyesters constitute an important class of polymers with a wide range of commercial uses. Interest in polyester as an industrial material stems from its excellent heat resistance, high strength and high modulus. In general, polyesters include: 1. direct polyesterification (eg, dicarboxylic acid + diol); 2. transesterification (dialkyl or diaryl ester + diol); 3. polycondensation of acid chloride and diol; It is produced by lactone ring-opening polymerization.

[0003] Although there are many other different processes for the preparation of polyesters, most of such conventional processes are difficult to handle with labile aromatic diacids or dichlorides, expensive starting materials and production. It is characterized by a high reaction temperature during the reaction.

The prior art teaches that polyesters are prepared by treating aromatic diiodide or dibromide and diols with carbon monoxide using a palladium catalyst, as exemplified in US Pat. Nos. 4,933,419 and 4,948,864. It shows that it can be manufactured by the following. This method by polycondensation of aromatic dihalides and diols for the production of polyesters based on the Heck reaction by palladium-catalyzed carbonylation was first developed by Emai and co-workers, and then by Perry and co-workers. Has been developed. A commonly used solvent is monochlorobenzene. The resulting polyester is soluble in the reaction diluent and can be recovered by precipitation in methanol. Thus, all reactants, including the reacting monomers, catalyst and resulting polyester, are soluble in the reaction medium. To date, only homogeneous catalyst compositions have been used in such methods. A particular drawback that neglected the commercial use of such homogeneous catalysts is the difficulty in efficient separation, recovery and further recycling of the catalyst. The loss of precious metals during frequent recovery cycles makes it uneconomical to operate such processes, and this loss undermines the technically attractive conversions obtained with homogeneous catalysts.

[0005] Due to the commercial interest in polyesters, the attention of academia as well as industry has been increasingly directed to the study of the development of new methods for their manufacture. In view of the advantages and features of the present invention, the method of the present invention would be a significant advance in the state of the art for polyester synthesis.

[0006] Polyesters constitute an important class of synthetic polymers, and have enjoyed commercial and commercial interest because of their high performance properties, such as excellent mechanical strength and heat resistance. Conventional methods for preparing polyesters are characterized by the handling of unstable and expensive reactants such as diacids, chlorides and the like and high temperatures. The literature shows that only homogeneous catalysts have been studied so far. A particular disadvantage of the commercial use of such homogeneous catalysts is the efficient separation of the catalyst,
Recovery and further recycling are difficult.
The loss of precious metals during frequent recovery cycles makes it uneconomical to operate such processes, and this loss undermines the technically attractive conversions obtained with homogeneous catalysts.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a polyester production method with catalyst recovery. A further object of the present invention is to provide a method for producing polyester using a noble metal catalyst such as a palladium catalyst, wherein the noble metal catalyst can be easily recovered and reused. .

SUMMARY OF THE INVENTION Accordingly, the present invention provides a compound of the general formula (III) [-CO-Ar ¹ -CO-O-Ar ^2-
O-] n wherein Ar ¹ is a divalent aromatic residue and Ar ²
Is an aromatic or alkyl residue), which comprises a catalyst containing a Group VIII metal and a heterogeneous carrier or carrier, a base and a solvent in the presence of a general formula (I) I-Ar -I (wherein Ar ¹ is a divalent aromatic residue) and an aromatic diiodide of the general formula (II) HO-R-OH (wherein Ar ² is a divalent aromatic or alkyl group And reacting with carbon monoxide.

In one embodiment of the present invention, the aromatic diiodide is m-diiodobenzene, p-diiodobenzene, 4,4'-diiodobiphenyl, bis (4-iodophenyl) ether and 2,7-diiodide. Selected from the group consisting of iodonaphthalene.

In one embodiment of the present invention, the diol is bisphenol A, 4,4'-dihydroxybiphenyl,
It is selected from the group consisting of 4'-biphenol, 4,4'-dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfone, 1,4-butanediol, 1,6-hexanediol and 1,3-propanediol.

In a further embodiment of the present invention, the Group VIII metal in the catalyst is selected from the group consisting of rhodium, palladium, platinum, nickel and cobalt.

[0012] In one embodiment of the invention, the catalyst is a heterogeneous palladium catalyst.

In a further embodiment of the present invention, the heterogeneous palladium catalyst is selected from the group consisting of Pd / C, Pd / Al ₂ O ₃ , Pd / CaCO ₃ , Pd / ZSM-5 and Pd / MgCl ₂ .

In another embodiment of the invention, the carrier is an inorganic material selected from the group consisting of carbon powder, alumina, silica, carbonates and chlorides of calcium, carbonates and chlorides of magnesium and zeolites; Alternatively, it is an organic carrier selected from the group consisting of polymers such as polystyrene, polyvinylpyrrolidene, polyaniline, and polyethylene glycol.

In another embodiment of the present invention, the catalyst is preferably a phosphine selected from the group consisting of triphenylphosphine, tritolylphosphine and trialkylphosphoin, or 1,3-diphenylphosphinepropane, 1,3 And diphosphine selected from the group consisting of 4-diphenylphosphinobutan and 1,3-diethylphosphinopropane.

In another embodiment of the present invention, the solvent is selected from the group consisting of dimethylacetamide, dimethylformamide, N-methylpyrrolidine, pyridene, benzene, toluene, monochlorobenzene, xylene and tetrahydrofuran.

In another embodiment of the present invention, the base used is of the general formula NR ₃ , wherein each R is an alkyl, aryl, cycloalkyl residue, which may be substituted or unsubstituted. Tertiary amines, metal hydroxides and metal carbonates.

In a further aspect of the invention, the base is D
It is selected from the group consisting of BU, DBN, DABCO, triethylamine, tributylamine, Na ₂ CO ₃ , KOH, NaOH and sodium acetate.

In a further embodiment of the invention, the base is used in the free state or immobilized on a carrier.

In a further embodiment of the present invention, the reaction is performed at a pressure between 0.1 and 100 bar.

In a further aspect of the invention, the CO used is pure.

In a further embodiment of the invention, the CO is diluted with another gas selected from the group consisting of argon, nitrogen and helium.

In a further embodiment of the present invention, the reaction comprises 6
The reaction is performed at a temperature of 0 to 210 ° C.

In another embodiment of the present invention, the heterogeneous catalyst is recycled.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the preparation of polyesters by contacting an aromatic diiodide, alkyl or aryl diol and carbon monoxide in the presence of a catalyst, an organic base and preferably a liquid reaction diluent. Provide a way. This catalyst is
Heterogeneous catalyst compositions comprising a Group VIII metal, preferably palladium. Hereinafter, the present invention will be described in more detail.

The catalyst used is a heterogeneous catalyst comprising a Group VIII metal and a heterogeneous carrier or support. As used herein and in the claims, the term "Group VIII metal" includes rhodium, palladium, platinum, nickel and cobalt. Catalyst compositions containing palladium are more preferred. According to the present invention, a wide range of compounds can act as carriers or carriers for the transition metals in the catalyst system. The support is preferably inert under the reaction conditions for better catalytic performance. The carrier may be an inorganic material or an organic compound. Examples of typical carriers include carbon powder, alumina, silica, carbonates and chlorides of calcium, carbonates and chlorides of magnesium, zeolites and the like. Suitable examples for organic carriers include polymers such as polystyrene, polyvinylpyrrolidene, polyaniline, polyethylene glycol. Typical examples of such catalysts are Pd on carbon, Pd / silica, Pd / γ-Al ₂ O ₃ , Pd / CaC
O ₃ , including Pd-ZSM5. The catalysts of the present invention can be easily prepared by procedures described in the literature without adversely affecting catalyst performance and without undue effort and modification. The metal / carrier ratio is not a true variable and can be adjusted by process constraints. In a typical composition, the metal / support ratio is between 0.001 and 1000. Catalyst compositions with metal / carrier ratios below or above these may be used if desired.

The amount of catalyst that can be used in the present process can vary widely.
It can be changed within the range. Generally, the amount of catalyst is
Based on the amount of diiodide used, at least about
10 ^-FiveMol%. Usually, the amount of catalyst is
0.00001 to 100 mol% of iodide. this
There is no real upper limit on the amount of catalyst used in the process.
And mainly due to the ease and cost efficiency of the method
It is decided.

It is advantageous to add a phosphine compound to the catalyst. Typical examples of phosphines that can be used are:
Includes triphenylphosphine, tritolylphosphine and trialkylphosphoin. Alternatively, a diphosphine compound can also be used. Typical examples of diphosphines include 1,3-diphenylphosphinepropane, 1,4-diphenylphosphinobutan, 1,3-diethylphosphinopropane. Alternatively, an active catalyst system can be prepared by supporting a preformed transition metal-phosphine ligand on a carrier. The amount of phosphine that can be used can vary widely, and usually a ligand to metal ratio of 6 to 0.01 is preferred.

[0029] In another embodiment, the method of the present invention can be performed using monofunctional or polyfunctional compounds. Monofunctional compounds act as endcapping agents. In a general context, bifunctional materials provide linear polyesters, while the use of more than two functional monomers provides branched polyesters. The reactive material should preferably not contain other functional groups that can react under the reaction conditions in order to avoid the formation of undesired by-products.

In another embodiment, the process of the present invention is not limited to a particular aromatic iodine compound, and includes various iodoaromatic compounds capable of reacting under the reaction conditions used to provide the polyester. It can be used as a monomer. The iodoaromatic compound has the general formula (I)
Ar is a hydrocarbon such as benzene, naphthalene, biphenyl, nitrogen, oxygen, an aromatic compound containing a hetero atom such as sulfur, such as pyridene, isoquinoline, dibenzofuran, thiophene, etc. Residue. The iodo substituents need not be attached to the same aromatic nucleus and may be separated by a bridging group. Preferred iodoaromatic compounds are m-diiodobenzene, p-diiodobenzene, 4,4′-diiodobiphenyl, 3,3′-diiodobiphenyl, 1,4-diiodonaphthalene, 2,6-diiodobenzene Includes iodonaphthalene, bis (4-iodophenyl) ether, 2,5-diiodothiophene.

The polyol used in the present invention is:
It can be represented by the general formula (II), wherein R can be alkyl or aryl. Examples of aryl R include aromatic diols where Ar is an aromatic system of (I). Typical examples of aromatic diols are 4,4'-biphenol, 1,4-dihydroxybenzene, 2,7-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, bis (4-hydroxyphenyl) ether, bis (4 -Hydroxyphenyl sulfone) and the like. Examples of alkyl R include those of the general formula (II
This is indicated by I). Suitable examples of aliphatic diols are linear _{diols, OH- (CH 2) n -OH} ( wherein, n 1 and 1
0). Alternatively, the aliphatic diol need not be essentially linear, and branched or substituted diols such as 2,2-dimethyl-1,3-propanediol and the like may be used.

The process according to the invention is preferably carried out in the presence of a liquid reaction medium. Various solvents may be used as the liquid reaction medium. Suitable examples are monochlorobenzene, N,
N-dimethylacetamide (DMAc), N, N-dimethylformamide (DMF), dimethylsulfoxide (DMS
O), N-methylpyrrolidone (NMP), and hexamethylphosphoramide. Examples of other solvents that can be used as solvents include tetrahydrofuran (THF), 1,4-dioxane, diglyme, alkane. The amount of solvent used is not limited and is preferably such as to ensure the most intimate mixing of the reactants.

The process according to the invention is preferably carried out in the presence of a base which acts as a neutralizing agent for hydrogen iodide which forms as a by-product during the course of the reaction. Preferably,
The base used according to the present invention has the general formula NR ₃ (wherein each R
Is independently selected from the group comprising alkyl, aryl, cycloalkyl residues, which may be substituted or unsubstituted). Suitable examples for such a base include DBU, DBN, DABCO, triethylamine, tributylamine. Or other bases such as metal hydroxides or metal carbonates, for example Na ₂ C
O ₃ , KOH, NaOH, sodium acetate may also be used. The base may be used in the free state or may be immobilized on a carrier. The amount of such base used should be at least sufficient to neutralize the hydrogen halide, but an excess may be used if desired.

In such a method, the preferred CO pressure is between 0.1 and 100 bar, especially between 1 and 30 bar. The CO used may be very pure or diluted with other gases such as argon, nitrogen or helium, and the amount of diluent may vary widely.

The process is preferably carried out at a temperature in the range from 20 to 300 ° C. Temperatures in the range from 70 to 160C are preferred. It is further disclosed that temperatures and pressures outside the indicated ranges may be used if desired.

A process for the catalytic production of polyesters is provided which comprises the separation, recovery and reuse of the catalyst. Catalysts that are insoluble in the reaction diluent can be easily separated because all other components, including the starting monomer, polyester product, are soluble. The catalyst can be washed with a suitable solvent, such as the solvent used as the reaction solvent, to better remove the substances adhering to its surface. The catalyst may be used as recovered in the next reaction or may be activated by typical activation methods such as calcination and the like. The polyester can be recovered by precipitation in methanol.

Although the reactions described herein to exemplify the catalytic activity and methods involve reference to individual monomeric compounds, the scope of the present invention is not limited to individual compounds, and the above described to provide polyesters. Includes various substrates of similar type that react under the presence and conditions of the catalyst. The advantageous features of the above catalyst systems and methods are as required by the ease of operation during and after the process, such as batch size, substrate reactivity, agitation, separation of catalyst and product, etc. Can be changed in a wide range.

The catalytic process according to the invention for preparing polyesters does not require high temperatures and the starting materials are particularly stable and easy to handle. The process of the present invention is based on a heterogeneous metal catalyst, which can be easily separated and efficiently recycled during the next process. This is difficult with competitive methods using homogeneous palladium catalysts.

The present invention will be described in more detail with reference to the following examples. The examples are illustrative only and should not be construed as limiting the scope of the invention.

Example 1 A polymerization reactor was charged with 4,4'-diiodobiphenyl (1.015 g, 2.5
Mmol), bisphenol A (0.570 g, 2.5 mmol), DBU (0.760 g, 5 mmol), triphenylphosphine (104 mg, 0.4 mmol), 5% Pd / CaCO ₃ (214 mg,
The Pd content was 10.7 mg, 0.1 mmol) and monochlorobenzene (20 ml) was charged. The polymerization reaction was carried out in a 50 ml volume SS autoclave supplied by Autoclave Engineers equipped with a stirrer, pressure transducer and pressure inlet and release valves. Thereafter, the reaction mixture was stirred and flushed twice with nitrogen, then with carbon monoxide and then heated to 140 ° C. When the desired temperature of 140 ° C. was reached, the vessel was pressurized with 300 psig carbon monoxide. The reaction was allowed to proceed for 3 hours. At the end of the reaction time, the vessel was cooled to room temperature and excess gas was vented off. Thereafter, the contents of the container were transferred to a glass jar and filtered. The heterogeneous catalyst was collected on filter paper and washed with 2 × 5 ml of monochlorobenzene to ensure that any adhering reactants or products were removed. The filtrate from the washing was poured into 100 ml of vigorously stirred methanol to precipitate the polyester as a white solid. Thereafter, it is filtered under vacuum and the solid content is
Washed with x20 ml methanol and dried in vacuo. The yield was 550 mg. The IR of the polymer is
17 which is characteristic of the carbonyl group C ＝ O of the ester function
It showed a peak at 34 cm ^-1 . O with a concentration of 3 g / l
By analyzing a solution of the polymer in -chlorophenol at 30 ° C., the reduced viscosity was determined to be 0.2 dL / g.

The above filtered catalyst was recycled without any treatment in the next test, using the same amounts of all other reactants as previously taken. Polymerization was performed essentially as before, yielding 310 mg of polyester. IR is 1734 which is characteristic of ester carbonyl.
A peak was shown at cm ^-1 . Analysis of a solution of the polymer in o-chlorophenol at a concentration of 3 g / l at 30 ° C. showed a reduced viscosity of 0.18 dL / g.

Example 2 Instead of 5% Pd / CaCO ₃ , 5% Pd / γ-Al ₂ O was used as a catalyst.
The procedure of Example 1 was repeated exactly, except that ₃ (214 mg, Pd content 10.7 mg, 0.1 mmol, in pellet form) was used. The polymerization reaction was carried out as detailed in Example 1. The yield was 350 mg. The IR of the polymer is 173, which is characteristic of the carbonyl group C ＝ O of the ester function.
It showed a peak at 4 cm ^-1 . O- at a concentration of 3 g / l
At 30 ° C. in chlorophenol, the reduced viscosity is 0.
It was determined to be 12 dL / g.

The catalyst from this reaction was recycled as described in Example 1 to give 80 mg of polyester. I
R showed a peak at 1734 cm ^-1 characteristic of ester carbonyl. Analysis of a solution of the polymer in o-chlorophenol at a concentration of 3 g / l at 30 ° C. showed a reduced viscosity of 0.11 dL / g.

Example 3 Exactly the procedure of Example 1 except that the catalyst used was based on a zeolite composition in which the active catalyst Pd (PPh ₃ ) ₂ was encapsulated (encapsulated) in a zeolite structure. Repeated. The net Pd content was determined by XRD to be 10.7%. After calcination for 14 hours, the catalyst was used in the polymerization reaction. The amount of catalyst taken was 100 mg, the Pd content was 10.7 mg, 0.1 mmol.

The polymerization reaction was carried out as described in Example 1 to give 210 mg of polyester. Polymer IR
Showed a peak at 1734 cm ^-1 which is characteristic of the carbonyl group C = O of the ester function. By analyzing a solution of the polymer in o-chlorophenol at a concentration of 3 g / l at 30 ° C., the reduced viscosity was determined to be 0.5 dL / g.

The above catalyst was recycled essentially as detailed in Example 1 to give 240 mg of polyester. IR is 1734 cm characteristic of ester carbonyl
^The peak was shown at ^-1 . Analysis of a solution of the polymer in o-chlorophenol at a concentration of 3 g / l at 30 ° C. showed a reduced viscosity of 0.45 dL / g.

Example 4 The catalyst used was 5% Pd / carbon (214 mg, Pd content 10.7 mg,
The procedure of Example 1 was repeated exactly, except that it was 0.1 mmol).

The polymerization reaction was carried out as detailed in Example 1 and 3
70 mg of polymer were obtained. The IR of the polymer is 1734c which is characteristic of the carbonyl group C = O of the ester function.
The peak was shown at m- ¹ . By analyzing a solution of the polymer in o-chlorophenol at a concentration of 3 g / l at 30 ° C., the reduced viscosity was determined to be 0.7 dL / g.

The catalyst was recycled as detailed in Example 1 to give 80 mg of polyester. IR showed a peak at 1734 cm ^-1 characteristic of ester carbonyl. Analysis of a solution of the polymer in o-chlorophenol at a concentration of 3 g / l at 30 ° C. showed a reduced viscosity of 0.7 dL / g.

Advantageous Features of the Invention The present invention demonstrates for the first time the use of heterogeneous catalysts for the production of polyesters using the catalytic carbonylation of diiodide and diol. 2. In contrast to competing homogeneous catalysts, heterogeneous catalysts as proposed in the present invention can be easily separated, recovered and subsequently efficiently recycled.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Sri Kant Maduka Kurkany India, Maharashtra, Pyun 411 008, National Chemical Laboratories (72) Inventor Lagunas Vittard Chardari India, Maharashtra, Pyun 411 008, National Chemical Laboratories F Term (reference) 4J029 AA08 AB04 AC02 BA02 BA04 BA05 BB09A BB10A BB13A BH02 CB01 CC03A DB13 HA01 HB05 HB07 HC08 JC033 JC551 JC561 JC571 JF561 JF571 JF581 KD01 KD05

Claims (18)

[Claims] 1. A compound of the general formula (III) [—CO—Ar ¹ —CO—O—Ar ² —O—]
_{n wherein} Ar ¹ is a divalent aromatic residue and Ar ² is an aromatic or alkyl residue, comprising a Group VIII metal and a heterogeneous carrier. Alternatively, in the presence of a catalyst comprising a carrier, a base and a solvent, a compound of the formula (I) I-Ar-I
(Wherein Ar is a divalent aromatic residue) and an aromatic diiodide represented by the general formula (II) OH-R-OH (wherein R
Is a divalent aromatic or alkyl group) and carbon monoxide. 2. The aromatic diiodide is a group consisting of m-diiodobenzene, p-diiodobenzene, 4,4′-diiodobiphenyl, bis (4-iodophenyl) ether and 2,7-diiodonaphthalene. The method of claim 1, wherein the method is selected from the group consisting of: 3. The diol is bisphenol A, 4,4 ′.
-Dihydroxybiphenyl, 4,4'-biphenol, 4,4'-
The method according to claim 1, wherein the method is selected from the group consisting of dihydroxydiphenylsulfone, 4,4'-dihydroxydiphenylsulfone, 1,4-butanediol, 1,6-hexanediol, and 1,3-propanediol. 4. The group VIII metal in the catalyst is rhodium,
The method of claim 1, wherein the method is selected from the group consisting of palladium, platinum, nickel and cobalt. 5. The method of claim 4, wherein said catalyst is a heterogeneous palladium catalyst. 6. The heterogeneous palladium catalyst is Pd / C, Pd / A
_{l 2 O 3, Pd / CaCO} 3, Pd / are selected from ZSM-5 and the group consisting of Pd / MgCl _2, The method of claim 5, wherein. 7. The method of claim 1, wherein said carrier is an inorganic material selected from the group consisting of carbon powder, alumina, silica, calcium carbonate and chloride, magnesium carbonate and chloride, and zeolite. 8. The method of claim 1, wherein said carrier is selected from the group consisting of polymers such as polystyrene, polyvinylpyrrolidene, polyaniline and polyethylene glycol. 9. The catalyst according to claim 1, wherein the phosphine is selected from the group consisting of triphenylphosphine, tritolylphosphine and trialkylphosphoin; or
The method of claim 1, comprising a diphosphine selected from the group consisting of 1,3-diphenylphosphinepropane, 1,4-diphenylphosphinobutan, and 1,3-diethylphosphinopropane. 10. The method of claim 1, wherein said solvent is selected from the group consisting of dimethylacetamide, dimethylformamide, N-methylpyrrolidine, pyridene, benzene, toluene, monochlorobenzene, xylene and tetrahydrofuran. 11. The base used is of the general formula NR ₃ , wherein each R is independently from the group comprising alkyl, aryl, cycloalkyl residues, which may be substituted or unsubstituted. The method according to claim 1, wherein the tertiary amine is selected from the group consisting of tertiary amines, metal hydroxides and metal carbonates. 12. The base is DBU, DBN, DABC.
O, triethylamine, tributylamine, Na ₂ C
O _3, KOH, selected from the group consisting of NaOH and sodium acetate The method of claim 11, wherein. 13. The method according to claim 1, wherein the base is used in a free state or immobilized on a carrier. 14. The process according to claim 1, wherein the reaction is carried out at a pressure of from 0.1 to 100 bar. 15. The method according to claim 1, wherein the CO used is pure. 16. The method according to claim 1, wherein the CO is diluted with a gas selected from the group consisting of argon, nitrogen and helium. 17. The method according to claim 1, wherein the reaction is carried out at a temperature in the range from 60 to 210 ° C. 18. The heterogeneous catalyst is recycled.
The method of claim 1.