DE2011711A1 - Process for the production of polyphenylene ethers - Google Patents

Description

The present invention relates to the formation of synthetic Polymer made from phenolic precursors, and it is particularly concerned with formation of polyphenylene ethers by self-condensation of phenols in a reaction system, which is an alcohol and contains a complex catalyst composed of a non-basic copper (II) salt and a primary or secondary amine is formed.

Polyphenylene ethers and processes for their preparation are well known and in numerous publications, for example U.S. Patents 3,306,874, 3,306,875, and 3,384,619, and in those concurrently with the present invention Application filed patent applications (1439-8CH-1245 and 1436-8CH-113).

0 098 40/21 oil

The process of the aforesaid US Pat. No. 3,306,875 involves the self-condensation of a monohydric phenol precursor using a catalyst which contains a tertiary amine-basic copper (II) salt complex. the polymerizable by this process η phenols have the the following structural formula:

Q "'

wherein X is a substituent selected from the group consisting of hydrogen, chlorine, bromine and iodine, Q is a monovalent substituent selected from the group consisting of hydrogen, hydrocarbon radicals, halogenated hydrocarbon radicals with at least 2 carbon atoms between the halogen atom and the phenol nucleus, oxyhydrocarbon radicals and halogenoxyhydrocarbon radicals with at least 2 carbon atoms between the halogen atom and the phenol nucleus; Q ¹ and Q ″ have the same meaning as Q and also mean halogen with the proviso that Q, Q ¹ and Q ″ are all free of a tertiary oil carbon atom. The polymers formed from the aforementioned phenols correspond to the following structural formula:

Q Q "

wherein the Äthersaue rstoffatom one repeating unit is connected to the phenylene nucleus of the next repeating unit; Q, Q · and Q "are as given above

009840/2101

Definition and η is an integer that is at least equal 100 is.

In the process according to the aforementioned US Pat. Nos. 3,306,874 and 3,306,875, the formation of the polyphenylene ethers comprises the self-condensation of a phenol in the presence of a catalyst system which contains a tertiary amine-basic η copper (II) salt complex. It is disclosed therein that the copper salt used to form the complex catalyst is not critical and can be either a basic copper (II) salt or a copper (I) salt, provided that when a copper (I) -Salt is used, it is able to exist in the copper-II state. If a copper (I) salt is used, the catalyst is presumably formed by reacting oxygen and water with an intermediate tertiary amine / copper (I) salt complex, thereby forming a tertiary amine-basic copper (II) salt complex . Various processes have already been described for the formation of the complex catalyst from a copper (II) salt. For example, it has been reported that a reducing agent can be used in conjunction with a copper (II) salt to form the copper (II) salt in place, which in turn forms the tertiary amine basic copper (II) salt complex when it does with which Am is mixed together. On the other hand, it has already been reported that the complex between a tertiary amine and a basic copper (II) salt is formed by reacting copper (II) salts with an alkaline salt of a phenol by reacting a copper (II) salt with an ion Exchanger resin with exchangeable hydroxyl groups Is treated by adding a base to a copper (II) salt or by adding copper (II) hydroxide to a copper (II) salt . U.S. Patent 3,306,874 is similar to the above with the exception that primary and secondary amines in place of tertiary amines.

0098AÖ / 2101

The aforementioned US Pat. No. 3,384,619 also relates to a process for the self-condensation of phenols with formation of high molecular weight polyphenylene ethers, but it differs from the two processes described above in that a catalyst is used which contains a tertiary amine and a non-basic copper (II) salt. It will claims therein that the reaction takes place in a solvent system must be carried out, which has at least 5 wt .-% alcohol, so as to obtain a high molecular weight polymer. In addition, the catalyst concentration in the reaction mixture is extraordinary in this process high, typically 9 parts of amine to 1 part of phenol, which makes the overall process expensive and becomes economically uninteresting. Finally, in that patent notes that attempts to make a polyphenylene ether in toluene have been made at these high catalyst concentrations and in the absence of the alcohol were unsuccessful and no polymer was formed.

The aforementioned co-filed patent application (1436-8CH-113) is directed to an improved method for the Self-condensation of high molecular weight polyphenylene ethers directed, using a complex catalyst consisting of a primary or secondary amine and an anhydrous non-basic copper (II) salt is formed. The method according to this application is characterized by the use the anhydrous, non-basic copper-11 salts and represents an improvement over US Patent 3,384,619 in which the concentration of the catalyst components in is relatively small with respect to the concentration of the monomer and accordingly significantly reduces the overall cost of the process are. In addition, the method according to this application represents an improvement over the other previously known Process, because the molecular weight of the formed in a given reaction time

009840/2101

Palyphenylene ether is larger than that of the other ways available or in other words, the response time for obtaining a polymer of comparable molecular weight shorter.

The present invention is now a further improvement on the invention described in co-filed patent application (1436-8CH-113), and it is based on the finding that the addition of a small amount of an alcohol, typically less than 3 wt. -% of the reaction components, the use of both hydrated non-basic copper (II) salts and aqueous solutions of non-basic copper (II) salts for the preparation of the complex catalysts for use in the formation of polyphenylene ethers. In addition, the addition of the alcohol to the reaction system also allows higher molecular weight polymers to be formed or the same molecular weights to be formed in a shorter reaction time using anhydrous cupric salts, hydrated cupric salts and aqueous solutions thereof. The ability to use hydrated copper (II) salts or their aqueous solutions is important as these materials are much more readily available than the anhydrous copper (II) salts and, accordingly, are less expensive. The process for forming the polyphenylene ethers according to the present invention therefore comprises passing ^! an oxygen-containing case with a solution containing the phenolic monomer and the complex catalyst formed from the primary or secondary amine and the non-basic copper salt in the presence of an alcohol.

The method according to the invention is generally applicable to such Pihe no le π, as they are in the aforementioned US patents ^ 3Q6 874 and 3 306 875 are described. However, it is particularly useful in conjunction with phenols, which are the

ÖQ984Q / 2101

correspond to the following structural formula:

OH

wherein Q and Q * are as defined above. The most preferred phenols in the process of the invention are those in which Q and Q ^{1 represent} hydrocarbon radicals having 1 to 8 carbon atoms. Examples of these most preferred phenols include 2,6-dimethylphenol, 2,6-diethylphenol, 2-methyl-6-ethylphenol, 2-methyl-6-allylphenol, 2-methyl-6-phenylphenol, 2,6-dibutylphenol, and 2-methyl-6-propyl-phenol.

The primary or secondary amine component of the catalyst complex corresponds to that described in the aforementioned US patent 3,306,874 are disclosed. Typical examples include aliphatic amines including cycloaliphatic amines in which the cycloaliphatic group is attached to the amine nitrogen is, e.g. mono- and dipropylamine, mono- and dibutylamine, Mono- and di-sec.-propylamine, mono- and dicyclohexylamine, Ethyl-methylamine, morpholine, methylcyclohexylamine, Ν, Ν'-dialkyl-ethylenediamines, the N ^ -dialkylpropanedimines, the Ν, Ν, Ν'-trialkylpentanediamines etc.

It will be apparent that mixtures of the primary and secondary amines can also be used if desired. Lower straight chain dialkyl monoareas such as dibutylamine and diethylamine are preferred. The concentration of the amines in the reaction mixture can vary within wide limits, but they are expediently added in lower concentrations. A preferred range is about 2.0 to 25.0 moles per 100 moles of the monomer.

009840/2101

■■■■■ -. _r 7 - ■ "■ '., ■

Typical examples of the copper (II) salts suitable for the process include copper (II) chloride, copper (II) bromide, Copper-II-sulfate, copper-H-azide, copper-ΙΪ-Τβtramine sulfate, Copper-II-acetate, copper-II-butyrate, copper-II-toluate etc. Preferred copper-11 salts are the Kupf e r-H-Ha loge η ide, with cupric bromide being most preferred. The concentration of the copper salts is expediently kept low, and preferably varies from about 0.2 to 2.5 moles per 100 moles of the phenolic monomer.

In the simultaneously filed patent application (1436) is it has already been stated that the non-basic copper (II) salts that are used to form the complex catalyst must be in their anhydrous form, instead of in a hydrate for ». In said application, this is a requirement because a small amount of water, which is present in the system prior to the formation of the complex of the amine and the non-basic salt, very detrimental to is the polymerization reaction and leads to the formation of a catalyst complex with a substantially reduced catalytic activity. For example, it was found that with a vain complex catalyst of copper (II) chloride dihydrate and an amine, a polymer is formed which is a has intrinsic viscosity less than about 50% of that of a polymer which using a catalyst composed of an amine and a anhydrous copper-1I chloride has been produced.

If, according to the present invention, an alcohol is added to the Reaction mixture is added, the copper (II) salt in a hydrated form or in an aqueous solution are present. The reason for this is not apparent, but the Ultimately, results are crucial. Since the hydrated copper salts and the aqueous solutions of the same are much more readily available and therefore cheaper

00 9 840/2101

there are therefore very decisive advantages. In addition, according to the invention, the further one results The advantage that the addition of the alcohol in a given reaction time leads to the formation of polymers with higher Molecular weight leads, or in other words, polymers with a corresponding molecular weight are in a shorter Response time received.

The nature of the alcohol used in the reaction system is not critical, although lower aliphatic alcohols to be favoured. Examples thereof are methanol, ethanol, propanol, butanol, allyl alcohol and the like. Methanol is the most preferred because it is often used as an anti-solvent for precipitation and recovery of the alcohol Polymers from the reaction solution is used. In a corresponding manner, the use of the methanol does not result in any additional organic compound is introduced into the reaction system. The amount of the alcohol is preferably low held and can for example 0.2 vol .-% of the total Reaction system. Preferably, the alcohol content is in the range of 0.5 to 3.0% by volume of the reaction system.

The polymerization reaction is carried out in a solvent of the general class described in the aforesaid U.S. Patents 3,306,874 and 3,306,875. Aromatic solvents like benzene and toluene give the best results. In addition, the reaction mixture can contain an activator, such as a diarylguanidine, as described, for example, in the patent application filed at the same time (1439-8CH-1245), or a diarylformamidine. In other respects, the method of forming the polymer and the conditions therefor, such as temperature, oxygen flow rate, and the like, are essentially the same as described in both of the aforesaid U.S. Patents 3,306,874 and 3,306,875

Q09840 / 2101

are, adjust the reaction time to generate high molecular weight Polymer is reduced. The aforementioned concentration ranges are preferred, although these ranges in to a certain extent, depending on the oxygen flow rate, the reaction temperature and the like. For economic reasons lower concentrations of copper · I I salt and Am in preferred. It is characteristic of the present invention that a reaction system using an alcohol and a catalyst complex consisting of a primary or secondary amine and a non-basic copper (II) salt is formed, the production of high molecular weight polymers with lower concentrations of copper (II) salts and amine permitted than would otherwise be permitted.

The invention is further illustrated by the following examples illustrated, Examples 1 to 4 procedures for the Compare the formation of a polyphenylene ether. In example 1 is a catalyst complex of an anhydrous, non-basic copper (II) halide and amine, in Example 2 an anhydrous copper (II) halide and an amine in the presence of an alcohol, in Example 3 an aqueous solution of one Copper (II) halides and an amine and in Example 4 one aqueous solution of a copper (II) halide and an amine used in the presence of an alcohol.

Example 1 ,

A catalyst complex was prepared in 100 ml of toluene in which 0.42 g of anhydrous Ruptfer-II bromide. 10.9 g of a di-n-butylamine and 4 ml of a 55% by weight solution of 2,6-xyleno! were stirred together in toluene, the catalyst complex prepared in this way was placed in a 1 ^ liter bottle marked with #ineY ^f TÄlscKla ^ and GftSein-

Conductive tubes for % iu ^ fs € of f and that the monomers were provided; Following in the preparation of the catalyst were 400 ml

Toluene was added and the mixture was rotated at a speed of 1500 revolutions / minute by a single 2 inch χ 1/4 inch turbine mixer while stirring oxygen at a rate of 1.0 cubic feet / hour in the reaction mixture was initiated. 127 g of a 55% strength by weight solution of 2,6-xylenol were then dissolved in Toluene added within 8 minutes. The temperature was kept at 30 ° C. during the reaction time by Water from a constant temperature bath was passed through the coil in the reaction mixture. After one hour and 45 minutes the temperature was increased to 35 ° C and after 15 minutes 30 ml of a 50 wt .-% aqueous Acetic acid solution added to stop the reaction. The mixture was centrifuged and the polymer added precipitated by methanol from the upper toluene phase. The polymer was filtered off, washed with methanol and stored at 70 ° C dried under vacuum. The poly (2,6-dimethyl-1,4-phenylene) ether was obtained in a yield of 90% of theory and the polymer had an intrinsic viscosity of 0.61 deciliters per gram (dl / g) as measured in chloroform at 30 ° C.

Example 2

The procedure described in Example 1 was repeated, but 6 ml of methanol were added to the components of the catalyst. The amount of methanol added corresponded to 1% by volume of the total reaction components in the reaction mixture. This was followed by the addition of the 2,6-xylenol in toluene. The polymer was obtained in a yield of 97% of theory and had an intrinsic viscosity of 0.65 dl / g.

0098 ^ 0/2101

Example 3

The process of Example 1 was repeated with the exception that 0.84 g of a 50% strength by weight aqueous copper (II) bromide solution was used instead of the anhydrous copper (II) bromide occurred in Example 1. The polymer was used in an amount of 58% of theory was obtained and had an intrinsic viscosity of 0.09 dl / g.

Example 4

The procedure of Example 3 was repeated, there were however 6 ml of methanol to the constituents of the catalyst system given. The polymer was obtained in a yield of 96% of theory and had an intrinsic viscosity of 0.55 dl / g.

The results of the preceding examples are in the following Table compiled again:

Example Copper Salt Addition Yield Base Molecular No. (%) Viscosity

(dl / g)

1 CuBr ₂ (anh) ~ 90 0.61

2, CuBr ₂ (anh) MeOH 97 P » ⁶⁵

0.09

3 CuBr ₂ (aq) - 58

4 CuBr ₂ (eq) MeOH 96 0.55

A comparison of Examples 1 and 2 shows that in the

application of anhydrous copper-11 brom id the addition of Methanol improves both the yield and the intrinsic viscosity. In Example 3 where an aqueous solution of cupric bromide was used to form the catalyst, the yield was low and the intrinsic viscosity unacceptable. The addition of methanol in

0098A0721D1 ^ _;

Example 4 led to a substantial increase in the yield and an intrinsic viscosity that was clearly was in the acceptable range.

Example 5

A catalyst complex was prepared in 100 ml of toluene by stirring together 0.76 g of anhydrous copper (II) chloride, 10.9 g of di-n-butylamine and 4 ml of a 55% strength by weight solution of 2,6-xylenol in toluene became. The catalyst complex prepared in this way was placed in a 1 liter bottle which was provided with cooling coils, a thermometer and inlet tubes for oxygen and the monomer. Following the preparation of the catalyst, 400 ml of toluene was added and the mixture was stirred with a simple 2 inch χ 1/4 inch turbine stirrer at a rate of 1500 revolutions per minute, with oxygen in the reaction mixture at a rate of 1.0 Cubic feet / hour was initiated. Then 123 g of a 55% solution of 2,6-xylenol dissolved in toluene were added over the course of 8 minutes. The temperature was kept at 30 ° C. during the reaction by passing water from a constant temperature bath through the coils in the reaction mixture . After one hour and 45 minutes, the temperature was increased to 35 ° C. and 15 minutes later 30 ml of a 55% strength by weight aqueous acetic acid solution were added to stop the reaction. The mixture was centrifuged and the polymer was precipitated from the upper toluene phase by adding methanol. The polymer was filtered off, washed with methanol and dried at 70 ° C. under vacuum. A yield of 65.0 g of poly (2,6-dimethyl-1,4-phenylene) ether (95% of theory) with an intrinsic viscosity of 0.46 dl / g was obtained.

009840/2101

Example 6

The procedure of Example 5 was repeated, there were but 6 ml of methanol (approximately 1% by volume of the total reaction components including monomers and solvents in the reaction mixture) added to the constituents of the catalyst. The polymer was in a yield of 92% of theory was obtained and had an intrinsic viscosity of 0.61 dl / g. A comparison of this example with example 5 showed a substantial increase in the basal molar Viscosity due to the addition of the methanol.

■ if "cn

- Hnir ■ "- - ■ _:

Example 7 «

The procedure of Example 6 was repeated, but the amount of methanol was increased to 12 ml, i.e. it was twice the amount used in Example 6. That Polymers were obtained in a yield of 93% of theory and had an intrinsic viscosity of 0.63 dl / g.

Example, 8

The procedure of Example 6 was repeated instead of the di-n-butylamine, however, 12.1 g tripropylamine was used. At the end of the two hour reaction time there was no Polymer isolated from the reaction mixture.

Example 9

The procedure of Example 6 was repeated instead however, of methanol, isopropyl alcohol was used. That Polymers were obtained in a yield of 97% of theory and had an intrinsic viscosity of 0.53 dl / g.

0 09 8 A Q A3 TO 1

Example 10

The procedure of Example 6 was repeated, but the concentration of cupric chloride was reduced by 50%. The polymer was obtained in a yield of 95% of theory and had an intrinsic viscosity of 0.46 dl / g.

Example 11

A tube-like reaction vessel, which is equipped with a Vibro-Idischer, Provided with a thermometer and an oxygen inlet tube was charged with 120 ml of toluene, 0.73 g of n-butylamine and 0.223 g (0.01 mol) of anhydrous cupric bromide. The mixture was stirred and 10.0 g of 2,6-xylenol dissolved in 20 ml of toluene was added. Oxygen was about Passed through the stirred mixture for 120 minutes, during which time the reaction temperature increased to 25 ° C was held. The polymerization reaction was carried out with acetic acid brought to a halt, the acid layer removed and the polymer precipitated with methanol. The polymer that comes with Methanol had been slurried and then dried in vacuo, weighed 9.1 g (93% of theory) and had an intrinsic molar Viscosity of 0.44 dl / g.

Example 12

The process according to Example 11 was repeated with the addition of 1% by volume of methanol (based on the total volume of the reaction system). The polymer was obtained in an amount of 91% of theory and had an intrinsic molecular viscosity of 0.50 dl / g.

Example 13

The procedure of Example 12 was repeated, replacing the methanol with 3% isopropyl alcohol. The polymer yield was 92.8% of theory and the polymer had an intrinsic molecular viscosity of 0.60 dl / g.

0098A0 / 2101

Claims (25)

"- 15 - patent claim 1. Process for the preparation of high molecular weight polyphenylenes ether from a manovalent phenol through an oxidative one Coupling reaction in the presence of a catalyst complex, that of a non-basic copper salt and an am in from the group of primary and secondary Amines, characterized in that the catalyst has been prepared in the presence of an alcohol. 2, method according to claim 1, characterized in, that the monovalent phenol of the formula corresponds to, wherein Q is a monovalent substituent from the Group consisting of hydrogen, hydrocarbon radicals, halogenated hydrocarbon radicals with at least 2 carbon atoms between the halogen atom and the phenol nucleus, oxyhydrocarbon radicals and (^ halogenated hydrocarbon residues with at least 2 carbon atoms between the halogen and the phenol nucleus and Q 'has the same meaning as Q and can also represent halogen with the proviso that Q and Q * are free of a tertiary carbon atom are. 3. The method according to claim 2, characterized in that g e k en η, that Q and Q 'represent alkyl radicals having 1 to 4 carbon atoms. 0Ö9B40 / 2101 4. The method according to claim 3, characterized in that the copper (II) salt from the group
is selected from anhydrous copper-II salts, hydrated copper-II salts and aqueous solutions of copper-II salts. 5. The method according to claim 3, characterized in that the alcohol in an amount of
no more than 5% by volume of the reaction mixture including the monovalent phenol of the catalyst complex
and the solvent is present. 6. The method according to claim 5, characterized in that the alcohol is in the range of 0.5
up to 3.0% by volume of the total reaction mixture is present. 7. The method according to claim 5, ^ characterized in that that the alcohol is a low molecular weight alkyl alcohol. 8. The method according to claim 7, characterized in that the alcohol is methanol. 9. The method according to claim 5, characterized in that the monovalent phenol is 2,6-dimethylphenol is. 10. The method according to claim 9, characterized in that that the copper-II-salt is a copper-II-Halögeηid is. 11. The method according to claim 10, characterized in that the copper (II) halide is copper (II) chloride is. 009840/2101 12. The method according to claim 1.0, characterized in that g e k e η η draws that the copper (II) halide copper (II) bromide is. 13. The method according to claim 10, characterized in that g e k e η η ze refuses- that the Am is converted into a straight-chain a iphatic Amine is. 14. The method according to claim 13, d a d u r c h e know - ζ e i c h η et that the amine is di-n-butylamine. 15, the method according to claim 10, characterized in that g e k e η η show h η e t,. that the copper (II) halide in its hydrated (water-containing) form. 16, the method according to claim 10, characterized ge kenn draws that the copper (II) halide in the form an aqueous solution is present » 17, Process for the formation of a high molecular weight polyphenylene ether the formula where Q and Q ^{s represent} monovalent substituents from the group consisting of lower aliphatic radicals with 1 to 4 carbon atoms and phenyl and η is an integer of at least 100, by oxidative coupling of a phenol frijröduct in the presence of an Ines' polymerisation catalyst complex a non-basic copper ^ II halide and an amine from the group consisting of primary and secondary amines, characterized in that that the catalyst is in the presence of an alcohol in an amount not greater than 5% by volume of the reaction mixture including the phenol, the catalyst complex and the solvent. 18. The method according to claim 17, characterized in that the alcohol is methanol and in
is present in an amount of from 0.5 to 3.0 percent by volume of the total reaction mixture. 19. The method according to claim 18, characterized in that Q and Q ^{1 are} each methyl. 20. The method according to claim 19, characterized in that the non-basic copper (II) halide Copper (II) chloride is. 21. The method according to claim 19, characterized in that that the non-basic copper (II) halide Copper (II) bromide is. 22. The method according to claim 19, characterized in that that the amine is an aliphatic ifonoamine is. 23. The method according to claim 22, characterized in that the amine is di-n-butylamine. 24. The method according to claim 19, characterized in that the copper-I! -Halide from the
Group of anhydrous copper (II) halides, hydrated copper (II) halides and aqueous solutions of
Copper (II) halides is selected. 009840/2101 25. yerfahreη according to claim 24, characterized in that g e k e η η ζ e ic h η e t that the kuipfer-II-Haiogenid in the form an aqueous solution is present.