DE2011711B2 - Process for the production of polyphenylene ethers - Google Patents

Description

OH

Q '

corresponds to, wherein Q and Q 'represent alkyl radicals having 1 to 8 carbon atoms and the reaction in Presence of a catalyst complex of anhydrous copper (II) salts, hydrated copper (II) salts or aqueous solutions of copper (II) salts and a straight-chain aliphatic amine and a low molecular weight alkyl alcohol in an amount of not more than 5% by volume of the reaction mixture composed of the monovalent phenol, the catalyst complex and the solvent.

2. The method according to claim 1, characterized in that the alcohol in the range from 0.5 to 3.0% by volume of the total reaction mixture is present.

3. The method according to claim 1 or 2, characterized in that the alcohol is methanol.

4. The method according to any one of claims 1 to 3, characterized in that the monovalent Phenol is 2,6-dimethylphenol.

Process according to Claim 4, characterized in that the copper (II) salt is a copper (II) halide is.

6. The method according to claim 5, characterized in that the copper-II halide is copper-II chloride is.

7. The method according to claim 5, characterized in that the copper-II halide is copper-II bromide is.

8. The method according to one or more of claims I to 7, characterized in that the Amine is di-n-butylamine.

The invention relates to a process for the production of high molecular weight polyphenylene ethers a monovalent phenol through an oxidative coupling reaction in the presence of a catalyst complex made from a non-basic copper-II salt and a primary or secondary amine in the presence of a solvent and optionally an activator.

Polyphenylene ethers and processes for their preparation are well known and in numerous ways Publications, for example US Patents 06 874, 33 06 875 and 33 84 619 and in the at the same time as this application filed its own patent applications DE-OS 20 Π 710 and DE-OS 20 11 709) described.

The process according to the aforementioned US Pat. No. 33 06 875 comprises the self-condensation of a monohydric phenol precursor using a catalyst of a tertiary amine-basic Copper (II) salt complex contains die after this process polymerizable phenols have 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, and halogenated hydrocarbon radicals having at least 2 carbon atoms between the halogen atom and the phenol nucleus, oxyhydrocarbon radicals and haloxyhydrocarbon radicals with at least 2 carbon atoms between the halogen atom and the phenol nucleus; Q 'and Q "have the same meaning as Q and

jo also mean halogen with the proviso that Q, Q 'and Q "are all free of a tertiary cn carbon atom. The polymers formed from the aforementioned phenols correspond to the following structural formula:

wherein the ether oxygen atom of one repeating unit with the phenylene nucleus of the next repeating unit Unit is connected; Q, Q 'and Q "have the given definition and η is an integer that is at least equal to 100.

In the method according to the aforementioned US Patents 33 06 874 and 33 06 875 includes Formation of the polyphenylene ethers the self-condensation of a phenol in the presence of a catalyst system, which is a tertiary amine-basic copper (II) salt complex contains. It is disclosed therein that the copper salt which is used to form the complex Catalyst is used, is not critical and is either a basic copper (II) salt or a Can be copper I salt, provided that if

fco a copper I salt is used, it is able to in to pass the copper-II state. If a copper I-salt is used, the catalyst is presumably formed by reacting with oxygen and water a tertiary amine-copper-I-salt complex occurring as an intermediate product, thereby forming a tertiary amine-basic copper (II) salt complex. It various processes have already been described for the formation of the complex catalyst

a copper (II) salt, for example, it has been reported that a reducing agent together with a Copper (II) salt can be used to form the copper (I) salt on the spot, whichever in turn forms the tertiary amine-basic copper (II) salt complex when it is mixed together with the amine. 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 making copper (II) salts with an alkaline salt of a phenol can be implemented by treating a copper (II) salt with an ion exchange resin with exchangeable hydroxyl groups by converting a base to a Copper (II) salt is added or by adding copper (II) hydroxide to a copper (II) salt. the US Pat. No. 3,3 06,874 is similar to the above except that primary and secondary amines can be used in place of the tertiary amines.

The aforementioned US Pat. No. 3,384,619 also relates to a method for self-condensation of Phenols with the formation of high molecular weight polyphenyl ethers, but it differs from the two method described above in that a catalyst is used which is a tertiary amine and contains a non-basic copper (II) salt. It is claimed therein that the reaction must be carried out in a solvent system which is at least 5% Has wt .-% alcohol, so as to obtain a high molecular weight polymer. In addition, this is Process, the catalyst concentration in the reaction mixture is extremely high, and that is omitted typically 9 parts of amine to 1 part of phenol, making the overall process expensive and economical becomes uninteresting. Finally, wildly noted in this patent that attempts to produce an iOlyphenylenäther in toluene, at these high Catalyst concentrations and in the absence of the alcohol were unsuccessful and no polymer was formed.

The aforementioned simultaneously filed patent application (DE-OS 20 11 709) is on an improved Process for the self-condensation of high molecular weight polyphenylene ethers directed, wherein a complex catalyst is used, which consists of a primary or secondary amine and an anhydrous non-basic copper (II) salt is formed. That The method according to this application is characterized by the use of the anhydrous, non-basic K.upfer-11 salts and represents an improvement over of US Patent 33 84 619, in which the concentration of the catalyst components in relation on the concentration of the monomer is relatively small and, accordingly, the overall cost of the process are significantly reduced. In addition, the method according to this application represents an improvement compared to the other previously known processes, namely because the molecular weight of the in Polyphenylene ether formed in a given reaction time is greater than in the case of the other way obtainable or, in other words, the reaction time is shorter for obtaining a polymer of comparable molecular weight.

The invention now represents a further improvement of that disclosed in its own laid-open specification 20 11 709 described invention, and it is based on the finding that the addition of a small amount an alcohol, in an amount less than 5% by weight of the reaction ingredients, the use

of both hydrated non-basic copper Π salts and aqueous solutions of non-basic Copper (II) salts for the manufacture of the complex catalysts used in the formation of Polyphenylene ethers also allow the addition of the alcohol to the reaction system likewise the formation of polymers with a higher molecular weight or the formation of the same molecular weights in a shorter reaction time when using formation of anhydrous copper (II) salts, hydrated copper (H) salts and aqueous solutions thereof. the Ability to use hydrated cupric salts or their aqueous solutions is important there these materials are much more readily available than that anhydrous copper (II) salts and accordingly less are expensive.

The process for preparing the high molecular weight polyphenylene ethers according to the invention is thereby characterized in that the monovalent phenol of formula

corresponds to, in which Q and Q 'are alkyl radicals with 1 to 8 Represent carbon atoms and the reaction in Presence of a catalyst complex of anhydrous copper-H-salts, hydrated copper-I-salts or aqueous solutions of copper-II-salts and a straight-chain aliphatic amine and one low molecular weight alkyl alcohol in an amount of not more than 5% by volume of the reaction mixture of the monovalent phenol, the catalyst complex and the solvent.

Examples of the phenols used in the present invention

include 2,6-dimethylphenol, 2,0-diethyIphenol, 2-methyl-6-ethylphenol, 2-methyl-6-alIyiphenol, 2-Me ethyl-6-phenylphenol, 2,6-dibutylphenol and 2-methyl-6- propyl phenol.

The primary or secondary amine component

of the catalyst complex are straight-chain aliphatic amines such as dibutylamine and diethylamine. The concentration of the amines can be in the The reaction mixture can vary within wide limits, but it is expedient to use a low concentration added. A preferred range is 2.0 to 25.0 moles per 100 moles of the monomer.

Typical examples of those suitable for the method Copper (II) salts include copper (II) chloride, copper (II) bromide, copper (II) sulfate, and copper (II) azide. Copper-II-Te- tramine sulfate, copper (II) acetate, copper (II) butyrate Copper (II) toluate. Preferred copper (II) salts are Copper-II halides, with copper-II bromide am is most preferred. The concentration of the copper salts is expediently kept low and varied preferably from 0.2 to 2.5 moles per 100 moles of the phenolic monomer.

In the patent application filed at the same time DE-OS 20 11 719 has already been recorded that the non-basic copper (II) salts that lead to the formation of the complex catalyst are used in their must be in an anhydrous form rather than in a hydrated form. In this said application is this is a requirement because a small amount of water that

is present in the system prior to the formation of the complex of the amine and the non-basic salt is detrimental to the polymerization reaction and essential to the formation of a catalyst complex with a decreased catalytic activity For example, it was found that with a complex catalyst of copper (II) chloride dihydrate and an amine, a polymer is formed, which has an intrinsic viscosity less than about 50% that of a polymer which using an amine and anhydrous copper (II) chloride catalyst been isL

The alcohol used in the reaction system is a lower aliphatic alcohol. Examples are methanol, ethanol, propanol and butanol. Methanol is the most preferred because this alcohol is often used as an anti-solvent to precipitate and recover the polymer from the reaction solution. In a corresponding manner, no additional organic compound is introduced into ice reaction system by the use of the Methanois. The amount of alcohol is preferably kept low and can be, for example, 0.2% by volume of the entire reaction system. The alcohol content is preferably in a range from 0.5 to 3.0% by volume of the reaction system.

The polymerization reaction is carried out in a solvent from the general class such as those described in US Pat aforementioned US patents 33 06 874 and 33 06 875 is carried out. Aromatic Solvents like benzene and toluene give the best results. In addition, the reaction mixture an activator such as a diarylguanidine, for example as described in the co-pending patent application DE-OS 20 11 710, or contain a diarylformamidine. In other ways are the process for forming the polymer and the conditions for it, such as temperature or oxygen flow rate essentially the same as in the two aforementioned US patents 33 06 874 and 33 06 875 are described, although the reaction time for the production of high molecular weight polymers is decreased. The aforementioned concentration ranges are preferred, although these ranges are in to some extent, depending on the oxygen flow rate or the reaction temperature can vary. For economic reasons, lower concentrations are used Copper (II) salt and amine are preferred. It's for that Invention characteristic that a reaction system using an alcohol and a catalyst complex, formed from a primary or secondary amine and a non-basic copper-II salt is the production of high molecular weight polymers with lower concentrations of copper (II) salts and Amin allowed than would otherwise be allowed.

The invention is explained in more detail by the following examples, examples 1 to 4 methods compare for the formation of a polyphenylene ether. In Example 1, a catalyst complex is made of one 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 a copper-III halide and an amine and in Example 4 an aqueous solution of a Kupt'c, -Il halide and an amine in Presence of an alcohol used.

Comparative example 1

A catalyst complex was prepared in 100 ml of toluene in which 0.42 g of anhydrous copper (II) bromide, 10.9 g of a di-n-butylamine and 4 ml of a 55% strength by weight solution of 2,6-xylenol in Toluene were stirred together. The catalyst complex produced in this way was placed in a 1 liter bottle which was provided with a cooling coil, a thermometer and gas inlet tubes for oxygen and the monomer. Following the preparation of the catalyst, 400 ml of toluene were added and the mixture was stirred at a rate of 1500 revolutions / minute through a single 5 cm χ 0.63 cm turbine mixer, while oxygen was passed into the reaction mixture at a rate of 2831 / hour became. 127 g of a 55% strength by weight solution of 2,6-xylenol dissolved in toluene were then added over the course of 8 minutes. The temperature was maintained at 30 ° C. during the period by flowing water from a Honsianien temperature bath 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% strength by weight aqueous acetic acid solution were added in order 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. 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), measured in chloroform at 3O ⁰ C.

example 1

That in comparison example! ! described procedure was repeated, but 6 ml of methanol was added to the components of the catalyst. the 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-xylenoIs in Toluene. The polymer was obtained in a yield of 97% of theory and had an intrinsic molar mass Viscosity of 0.65 dl / g.

Comparative example 2

The procedure of Comparative Example 1 was repeated except that 0.84 g of a 50 wt .-% aqueous copper (II) bromide solution instead of the anhydrous copper (II) bromide in the comparative example 1 stepped. The polymer was obtained in an amount of 58% of theory and had a base molar Viscosity of 0.09 dl / g.

Example 2

The procedure of Comparative Example H2 was repeated except that 6 ml of methanol were added Components of the catalyst system given. The polymer was obtained in 96% yield Theory obtained and had an intrinsic viscosity of 0.55 dl / g.

The results of the preceding examples are shown in FIG the following table compiled again:

Copper salt additive

Comparative example 1
example 1

Comparative example 2
Example 2

CuBr, (anh) CuBr, (anh) CuBr ₂ (aq) CuBr ₂ (aq) MeOH
MeOH

yield Basal molars viscosity (%) (dl / g) 90 0.61 97 0.65 58 0.09 96 0.55

Comparing Comparative Example I and Example I. shows diili when using anhydrous Copper-II-Btomid the addition of methanol improves both the yield and the base molar viscosity. In Comparative Example 2 where an aqueous solution of copper-II-bromide for the formation of the catalyst was used, you were · hatching low and the intrinsic viscosity unacceptable. The addition of methanol in Example 2 resulted in a substantial Increase in the yield and an intrinsic molar viscosity. which are clearly in the acceptable Area lay.

Comparative example 3

A catalyst complex was prepared in 100 ml of toluene by adding 0.7bl ^{t of} anhydrous copper-II chloride. 10.4 g of di-n-butylamine and 4 ml of a 55% strength by weight solution of 2,6-xylenol in toluene were stirred together. The catalyst complex produced in this way was placed in a two-liter bottle, which was provided with cooling coils, a thermometer and linear tubes for oxygen and the monomer. Following the preparation of the catalyst, 400 ml of toluene were added and the mixture was stirred with a simple 5 cm χ 0.63 cm turbine stirrer at a speed of 1500 revolutions / minute, oxygen being introduced into the reaction mixture at a rate of 28.3 l / hour . Then 123 g of a 55% solution of 2,6-xylene, dissolved in toluene, were added over the course of 8 minutes. The temperature was kept at 30 ° C. during the reaction by flowing water from a constant temperature bath through the coils in the reaction mixture ml of a 55% ^by weight aqueous f. acetic acid solution was added to terminate 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 treated with 7O ⁰ C dried under vacuum. There was (theory 95%) having an intrinsic viscosity of 0.46 obtained dl / g, a yield of 65.0 g poly (2.6-dimethyl-l, 4-phenylene) ether.

Example 3

The procedure of Comparative Example 3 was repeated, but 6 ml of methanol (approx % By volume of the total reaction components including monomers and solvents in the reaction mixture) added to the components of the catalyst. The polymer was obtained in a yield of 92% of theory and possessed a basal molar Viscosity of 0.61 dl / g. A comparison of this example with Comparative Example 3 showed an essential one Increase in the liquid molar viscosity due to the Adding the methanol.

Example 4

The procedure of Example 3 was repeated, but the amount of methanol was reduced to 12 m urslpi ^ pri ii h sie hiMrHtf (Ins Πηηηρίΐρ rinr in Rpknipl ^;

u ι- ■ ■ c- - ■ ■ r r - ■ - ■ - - ■ r ■ - ■

amount used. The polymer was obtained in a yield equal to or less than the theory possessed basal viscosity of 0.63 dl / g.

Example 5

The procedure according to Example 3 was repeated, instead of methanol, however, isopropyl alcohol was used. The polymer was in a yield of 97% dr · theory received and had a basal molar Vi 'viscosity number of 0.53 dl / g.

Example 6

The process according to Example 3 was repeated, but the concentration of the copper (II) chloride was reduced by 50%. The polymer was obtained in a ^{theoretical yield of 95 n} / n and had an intrinsic viscosity of 0.46 di / g.

Comparative example 4

Hin tubular reaction vessel, which with a vibrating mixer. Thermometer and an oxygen inlet tube was provided. was with 120 ml of toluene. 0.73 g of n-butylamine and 0.223 g (0.01 mol) of anhydrous copper (II) bromide are charged. The mixture was stirred and 10.0 g of the 2,6-xylenol dissolved in 20 ml of toluene were added. Oxygen was bubbled through the stirred mixture for approximately 120 minutes, during which time the reaction temperature increased to 25 ^; C was held. The polymerization reaction was stopped with acetic acid, the acid layer was removed and the polymer was precipitated with methanol. The polymer, which had been slurried with methanol and then dried in a vacuum, weighed 9.1 g (93% of theory) and had an intrinsic viscosity of 0.44 dl / g.

Example 9

The process according to Comparative Example 4 was repeated with the addition of 1% by volume of methanol (based on the total volume of the reaction system). The polymer was used in an amount of 91% obtained from theory and had an intrinsic viscosity of 0.50 dl / g.

Example 10

The procedure of Example 9 was repeated, replacing the methanol with 3% isopropyl alcohol became. The polymer bulge was 92.8% of theory and the polymer had an intrinsic molar Viscosity of 0.60 dl / g.

Claims (1)

Patent claims: 1. Process for the production of high molecular weight polyphenylene ethers from a monovalent phenol by an oxidative coupling reaction in the presence of a catalyst complex of a non-basic copper-11 salt and one primary or secondary amine in the presence of a solvent and optionally an activator, characterized in that the monovalent Phenol of the formula