DE1420485C - Process for the production of poly phenylene oxides - Google Patents

Description

Processes for the oxidation of phenols in the presence of amines and copper (II) salts are known. Brackmann et al report in Rec. Trav. Chem. 74, 937/955, pp. 1021 to 1039, 1071 to 1080, UL to 1119 (1955), about an experimental work, in which oxygen with monocyclic and bicyclic phenols is reacted in the presence of a copper (II) salt and primary, secondary and tertiary amines. In Both the monocyclic and the bicyclic are present in the presence of primary and secondary amines Phenols oxidize with the formation of chemical compounds in which the amines are a constituent of the formed molecule. In the presence of a tertiary amine, only the bicyclic Phenols, e.g. B. naphthols, oxidize. In this case the products form simple connections, such as Naphthoquinones made from 1 or 2 molecules of naphthol, naphthones made from 2 molecules Naphthol were formed, as well as in the case of // - naphthol (naphthol-2), one of 3 molecules naphthoquinone formed by naphthol. On the other hand, there is no reaction if an attempt is made to monocyclic phenols in the presence of a cupric salt and tertiary amines to oxidize. Brackmann states on p. 939: “With regard to the phenols of the benzene series, tertiary amines are completely inactive «.

It has now been found that it is still possible to oxidatively link monobasic monocyclic phenols, being with almost quantitative yield

ίο higher molecular weight polyphenylene ethers with special favorable properties can be obtained. Here, the amine does not become a component of the reaction product, as is the case with the oxidation process of Brackmann et al is the case.

The invention relates to a process for the preparation of polyphenylene oxides, which is characterized in that a copper amine complex prepared from a tertiary amine and a copper (I) salt soluble therein is mixed in the presence of oxygen at temperatures not exceeding 100 ^° C. with phenols general formulas

OH

^R 0 ^x

R '

II

in which X is a hydrogen, chlorine, bromine or iodine atom, R 'is a halogen atom or R and R are Hydrogen atom, a hydrocarbon, hydrocarbonoxy, halohydrocarbon or a Halohydrocarbonoxy radical, where the aliphatic halogenated substituents at least Have 2 carbon atoms between the halogen atom and the phenol nucleus, all aliphatic substituents at least one hydrogen atom on the carbon atom bonded to the phenol nucleus carry and R and R 'in the general formula II not both a halogen atom or an aryl, hydrocarbonoxy or halocarbon oxy radicals.

Here, the halocarbon oxy radicals should have at least 2 carbon atoms between one Have halogen atom and the phenol nucleus. Halomethyl groups are hydrolytically so reactive that that they form undesirable by-products in the oxidation reaction. They are quite general Except for substituents R or R 'which carry an aliphatic tertiary carbon atom. the The reasons for this are set out below.

The hydrogen atom participates in the oxidation reaction in the presence of the copper catalyst system the phenolic group of a phenol molecule, a hydrogen, chlorine, bromine or iodine substituent in the ortho (2) or para (4) position of another phenol molecule and oxygen below the formation of water according to the following reaction scheme, which shows the para position applies:

3 2

J 2

, OH ["OH-] 5 h

5 <>

5 (>

- + H ₂ O

(A)

In the following, the numbers are used to designate the position of the substituents and the connecting points; η is an integer of at least 10 and is 100 to 1500 and more in the film and fiber-forming range.

The type of copper (I) salt used does not matter if it can only exist in the copper (II) state and form a complex with the tertiary amine which is soluble in the reaction medium. The necessity of being able to exist in the copper (II) state is based on the assumption that the oxidation of the phenol is brought about by an intermediate product of an activated copper (II) amine complex, which reacts with the phenol to regenerate the copper (I) -aminkoniplexcs responds. As far as can be determined, it is impossible to form this activated complex from a copper (II) salt. Typical examples of the copper (I) salts suitable for this process are: copper (I) chloride, copper (I) bromide, copper (I) sulfal, copper (I) azide, copper (I) tetramine sulfate, Copper (I) _: acetate, copper (I) propionate, copper (l) palmital, copper (l) benzoate, etc.

Copper (I) chloride, copper (I) broinide and copper (I) a / id provide the polyphenylene ethers with the highest molecular weight. Although you don't have copper (II) sulfite knows, copper (l) sulphate can be used, since it is apparently oxidized to copper (l) sulphate. Kiipfcr (l) -salzc, like Kupfcr (l) -iodide, Kupfei (l) -sulful, Kupler (l) -cyanid and copper (1 ') -iodanide are / are in use

not suitable in this process because they are either insoluble in tertiary amines or they are not can form stable copper (II) salts. For example, copper (II) cyanide and copper (II) rhodanide decompose autogenous to the corresponding copper (I) salts. The existence of copper (I) nitrate and copper (I) fluoride is not known, but the amine complexes can be prepared in situ. A substitute for the copper (I) salts by copper (II) chloride, copper (II) sulfate, copper (II) chlorate and copper (II) nitrate does not provide any oxy- ίο dation of monocyclic phenols in the presence of a tertiary amine. Confirm these results the work of B r a c k m a η η et al.

Examples of tertiary amines that can be used in the practice of the invention are aliphatic tertiary amines, such as trimethylamine, triethylamine, tripropylamine, tributylamine, diethylmethylamine, dimethylpropylamine, Allyl diethylamine, dimethyl-n-butylamine, diethylisopropylamine, benzyldimethylamine, Dioctylbenzylamine, dioctylchlorobenzylamine, dirnethylcyclohexylamine, Dimethylphenethylamine, benzylmethylethylamine, di- (chlorophenethyl) bromobenzylamine, l-dimethylamino-2-phenylpropane and 1-dimethylamino-4-pentane.

If aliphatic tertiary amines are used, at least two of the aliphatic groups should be used be straight chain hydrocarbon groups.

Examples of cyclic amines are the pyridines, such as pyridine itself, quinuclidine, the N-alkylpyrroles, the N-alkylpyrrolidines, the N-alkylpiperidines, the Quinolines, isoquinolines, N-alkyltetrahydroquinolines, N-alkyl tetrahydroisoquinolines and N-alkyl morpholines including the ring-substituted products of these cyclic amines in which one or more Hydrogen atoms on the ring-forming carbon atoms can be substituted by the following groups: Alkyl (ζ. Β. Methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl and their isomers and Homologues), alkoxyl (e.g. methoxyl, ethoxyl, propoxyl, butoxyl and the isomers and homologues), Aryl- (ζ. B. Phenyl-, ToIyI-, Dimethy, phenyl-, chlorine- < phenyl, bromotolyl, naphthyl, chlorobromonaphthyl and their isomers and homologues), oxyaryl (ζ. Β. Oxyphenyl, oxytolyl, oxyxylyl, oxychlorphenyl, oxynaphthyl groups and their isomers and homologues). The ring substituents can be identical or different hydrocarbon groups. Piperidines, Pyrroles, pyrrolidines, tetrahydroquinolines or tetrahydroisoquinolines are tertiary in the form Amines used in which a hydrocarbon radical, as defined above, with the amine nitrogen connected is.

The effect of an N-aryl group in tertiary Amines, e.g. B. N, N-dimethylaniline or methyldiphenylamine is the basicity of the amine to reduce, so that its ability to form the copper complex is largely reduced. Besides that the stability of the amine is also largely reduced under oxidizing conditions. Because For these two effects, it is better not to use tertiary amines that have an N-aryl substituent. The preferred inclusion of the ortho or para positions in the oxidation reaction is so pronounced that if one of the three positions is substituted by a halogen (except fluorine, which is not (\ s reacts) and the other two are substituted with a hydrocarbon radical which removes halogen In this case the llalogenatoni reacts with 1 molecule of the copper catalyst and inactivates it. Therefore it is necessary to use 1 mole of catalyst per Atom removed halogen to use. This halogen removal does not extend to phenols, the Carry a halogen in each of the two ortho positions, since in this case the electronegativity of the both halogens the phenolic hydroxyl group inactivated so that the phenol after this process cannot be oxidized. When a hydrocarbon and a halogen occupy the ortho positions and either hydrogen or a halogen, besides fluorine, the para position, only the para position appears to take part in the oxidation reaction. Take hydrogen and a hydrocarbon residue the ortho positions one and a halogen, except fluorine, the para position, then both can, the Hydrogen and the halogen, participate in the oxidation reaction in the same way as when both positions would be substituted with hydrogen. As a reaction involving the hydrogen atoms in the ortho or para positions does not destroy the catalyst, only a small one has to be catalytic amount applied, in the order of 0.1 to IO mole percent, based on the moles to be oxidized phenol. Therefore, phenols are preferred according to the invention, which at the in the Oxidation reaction involved ring position carry hydrogen.

Halomethyl groups are hydrolytically so reactive that they are undesirable in the oxidation reaction Form by-products. Hence, phenols containing such substituents become major reactants best excluded from the reaction mixture, although in small amounts may be present as modifiers. Other ring substituents, such as nitro, cyano, carboxyl and formyl groups which can react with amines or copper salts should also be used as substituents of the phenols used as major reactants are excluded, although phenols containing these groups are in small amounts can be used as a modifier of the polymer obtained.

It was also found that groups with large space requirements, i.e. H. approximately spherical groups, z. B. the tert-butyl group and higher homologues, aryl groups, oxyalkyl groups, the oxidation reaction not stopping, but only forming diphenylquinones.

This leads to the following observation regarding aliphatic Orthosubstituents on the phenolic starting materials: Substituents that form an aliphatic Carrying tertiary a-carbon atoms, deliver the corresponding diphenylquinones and prevent the formation of Polyphenylene ethers if at least one such ortho-substituent is present. Typical examples for such substituents are:

-C (CH.,),

C.
I. (CH.,), I.
C, Il S. C (C, Hs): C ₄ H,

-C (CHj) ₂

-C (C ₆ H ₅ ),
etc.

Substitutions which have an aliphatic secondary ίΐ-C atom prevent the formation of polyphenylene ethers not, but such ortho-substitution causes at least a minor one Formation of the corresponding diphenylquinone. Have two such ortho substituents result that the main part of the product consists of the corresponding diphenylquinone and me a A smaller proportion of the polyphenylene ether is .. Orthosubstituents, which are an aliphatic primary a-C atom do not prevent the formation of polyphenylene ethers.

It was also found that to obtain polyphenylene ethers with a very high molecular weight only the para position and the phenolic hydrogen take part in the oxidation reaction may. In contrast, polyphenylene ethers with low and medium molecular weights can pass through Oxidation of phenols obtained with only one reactive ortho position. Will oxidation performed with phenols, those with both ortho and para positions as well as with the phenolic Group can react, the polyphenylene ethers obtained represent a mixture of polyphenylene ethers with a three-dimensional structure. Such substances are extremely reactive and tend to transform liquids into gels without forming soluble solids that are isolated be able. Such substances are available as potting resins, impregnating agents or as thermosetting adhesives useful.

Surprisingly, you can according to the invention Processes produce polyphenylene ethers with a very high molecular weight, which are extraordinarily have high softening points in the range of 250 to 300 ° C or more, as can be seen from results in the required pressing temperatures for their deformation. Depending on the manufacturing conditions they remain either thermoplastic with continued heating in a vacuum to 250 ° C, or they harden to an infusible state in which they are no longer in the usual organic state Solvents, such as toluene, xylene, chloroform, nitrobenzene, etc., in which they are before the heat treatment were soluble, are soluble. Low molecular weight substances can be obtained by either controls the amount of reacting oxygen or by adding a liquid to the reaction mixture which forms a solvent for the starting material, but afterwards for the reaction products they have reached a predetermined molecular weight is not a solvent. The speed the oxidation is of the amount of what is present Copper (I) catalyst dependent. In order to achieve a sufficient reaction speed, it is preferred to use at least 1 mol percent copper (I) ~ catalyst, based on the Amount of phenol used. There should be 2 amine nitrogen atoms per copper atom. To the inventive method one can polyphenylene ethers with molecular weights of at least 10000 received.

These high molecular weight substances represent new chemical masses. So far, polyphenylene ethers were z. B. produced by the Ullman reaction between a parabromophenol and a potassium phenolate in the presence of copper powder. However, such a reaction is apparently unable to produce polyphenylene ethers having more than about eight repeating units, so that the molecular weights are limited to about 1,000. Such substances are still crystalline and have sharp melting points. Bromicrt z. B. Diphenyloxyd and reacts it with potassium phenolate, brominates the compound obtained again and reacts it again with potassium phenolate, so the extreme product to be obtained seems to be C ₆ H ₅ O (QH ₄ OItQHs, which has a melting point of 199 to 200 ⁰ C has.

The preferred class of phenols for making high molecular weight resins is equivalent to formula

OH

in which R and R "correspond to the definition of Formula 2 and the three positions shown with no substituents are one linked to the ring carbon Carry hydrogen atom.

Typical examples of monovalent hydrocarbon radicals, which in all of the above formulas R and R " are: alkyl, including cycloalkyl, ζ. B. methyl, ethyl, propyl, isopropyl, butyl, sec. Butyl, tert. Butyl, isobutyl, cyclobutyl, amyl, Cyclopentyl, hexyl, cyclohexyl, methylcyclohexyl, ethylcyclohexyl, octyl, decyl, octadecyl; Alkenyl, including cycloalkenyl, ζ. B. vinyl, allyl, butenyl, cyclobutenyl, isopentenyl. Cyclopentenyl, linolyl; Alkynyl e.g. B. propargyl; Aryl, including alkylaryl, z. B. Phenyl, ToIyI, ethylphenyl, XyIyI, naphthyl, methylnaphthyl; Arylalkyl, e.g. B. benzyl, phenylethyl, Phenylpropyl, tolylethyl. The monovalent halocarbon radicals can be the same as that hydrocarbon radicals indicated above, except methyl, in which one or more hydrogen atoms are replaced by halogen. Examples for this are:

Chloroethyl, bromoethyl, fluoroethyl, dichloroethyl, bromopropyl, difluoroiodoethyl, bromobutyl, fluoramyl, Chlorovinyl, bromallyl, fluoropropargyl, mono-, di-, tri-, tetra- and pentachlorophenyl, mono-, di-, tri- and tetrabromotolyl, chloroethylphenyl, ethylchlorophenyl, fluoroxylyl, chloronaphthyl, bromobenzyl, iodophenylethyl, Phenylchloroethyl and bromotolylethyl.

Typical examples of monovalent hydrocarbonoxy radicals are: methyloxy, ethoxy, propyloxy, Isopropyloxy, butyloxy, sec-butyloxy, tert-butyloxy, amyloxy, hexyloxy, octyloxy, decyloxy, vinyloxy, Allyloxy and butenyloxy. The monovalent halohydrocarbonoxy radicals may be the same as the above oxyhydrocarbons with the exception of the methyloxy radical in which one or more hydrogens by halogen, e.g. B. fluorine, chlorine, bromine or iodine are replaced.

As already mentioned, phenols with two reactive positions provide three-dimensional ones

Polymers that are extremely reactive and tend to be polymers of complex structure form, surprisingly it was found that Phenols which have two or three unsubstituted ortho- or para-positions, i.e. two or three 5 responsive positions, under. Formation of solid, fusible polyphenylene ethers can be oxidized, the same as those obtained from phenols, which have only one reactive ortho or para position own, were produced. This is achieved through the use of a tertiary amine in the catalyst system achieves that one or two large bulky substituents or spatially immobile groups wears one or both ortho positions effectively To block.

Apparently, the amine copper complex attaches itself to the phenolic hydroxyl group when it is used as a Oxidation catalyst works. Therefore, when the amine carries large bulky organic groups that Shielding or sterically hindering ortho positions, this has the effect that the reaction with the para position, if it is reactive, expires. If the para position is not reactive, then the reaction takes place still beyond one of the ortho positions, but the products have a much lower molecular weight, than was the case with phenols, which have only one reactive ortho position. It was found that the cyclic amines are particularly well suited for use in this catalyst system are if one or both ortho positions of the phenol should be blocked. With the cyclic amines, such as the pyridines and quinolines, the Rings spatially arranged in such a way that each substituent in either the 2- or 6-position is unsubstituted Ortho position of phenol blocked, while 35; rend substituents in both, the 2- and 6-position, block both unsubstituted ortho positions of a phenol. A phenol therefore only has an unsubstituted one In the ortho position, the cyclic amine only needs one substituent in the 2-position, e.g. B. α-Picoline- (2-methylpyridine). If both ortho positions of the phenol are unsubstituted, the cyclic amine would be Substituents in both the 2- and 6-positions require ^ z. B. 2,6-lutidine.

In general, amines, including tertiary amines, tend to break up in the presence of oxygen discolor, even if left in the presence of a limited amount of air. This tendency to Discoloration with simultaneous formation of complex products appears with pyridine and its ring-substituted derivatives not to be as pronounced as e.g. B. in the closely related quinolines. It was found that when using tertiary amines, which tend to discolour, in the absence a nitroaromatic compound, the products of the invention are not as pure and the physical ones Properties are not as favorable as when a tertiary amine is used, soft in Presence of oxygen is stable. Therefore, under such conditions, the use of Pyridine is preferred as the tertiary amine in the catalyst mixture.

It is assumed that 1 mole of cuprous salt forms a complex with 2 moles of amine. This complex can react with oxygen to form an oxidized intermediate that reacts to various Way can form a complex with the phenol. The latter complex activates the aryl core so that the polymer chains are formed with regression of the catalyst in the original state will. This assumption is based on the fact that when oxygen is introduced into the Catalyst system up to saturation with subsequent addition of phenol without further addition of oxygen 1 mole of phenol is oxidized per 2 moles of catalyst present. The following equations show these reactions, where an 0 represents the aryl nucleus of the phenolic reactant, (A) the tertiary amine and CuCl for a typical copper (I jsalz stands.

2 (A) + CuCl - ^ £ U H ₂ O: Cu: Cl -i3- »HO: Cu: Cl + H ₂ O

(A)

CfO: Cu: Cl

χα)

Herein, b can be two or more. The above equations also show the contribution of the water.

Although mixtures of tertiary amines and mixtures of copper (I) salts can be used, there is no benefit therefrom. The copper (I) salt is preferably dissolved in the tertiary amine before the phenolic reactant is added. In some cases, the dissolution of the copper salt can be accelerated by heating the mixture, bubbling in air or oxygen, or a combination of both. To fully utilize the copper, enough amine should be added to dissolve all of the added copper acid through complex formation. Bigger (A)
^ L (0O) ₁ , + H ₂ O: CuCl

Excesses of amine do not favorably influence the reaction, but they can in some cases be desirable to completely dissolve all phenolic reactants and as a solvent for the To serve reaction products. Other solvents such as alcohols, ketones, hydrocarbons, chlorinated hydrocarbons, Nitro hydrocarbons, ethers, esters, amides, mixed ether-esters or sulfoxides can be present in the reaction system as long as they do not interfere with the oxidation reaction or because of it take part. Then oxygen or an oxygen-containing one Gas introduced into the reaction mixture, where it causes an exothermic reaction to occur With formation of water as a by-product;

109Ä22 / 339

To prepare the polyphenylene oxides by the process according to the invention one prevents z. B. in batch operation, it is best to allow this water of reaction to escape from the reaction vessel, or the escape of the water is controlled in a manner known to those skilled in the art so that there is always 1 mole of water per mole of copper catalyst. In practicing the invention, the oxygen can be diluted with an inert gas such as nitrogen, helium, or argon, or air can be used. In order to avoid local overheating as a result of the exothermic reaction and the associated disruptive side effects, it is advisable to start the oxidation reaction at the lowest possible temperature, which is indicated by the release of heat during the reaction. Typically, the oxidation reaction is controlled by removal of heat so that the maximum temperature does not exceed 100 ° C and preferably not higher than 8O ⁰ C.

Usually the introduction of oxygen into the reaction mixture is continued until no heat more is released or the intended amount of oxygen is absorbed. But you can also during the oxidation reaction continuously or intermittently the same or a different phenol as the starting material add to make one mixed polyphenylene ether, the other. Has structure, as if one had used the mixed phenols as starting material. To stop the reaction, if the catalyst system is destroyed by adding an acid, preferably a mineral acid, such as hydrochloric acid or sulfuric acid, which reacts with the tertiary amine and with the copper (l) salt. Or the reaction product is separated from the catalyst, either by filtering off, if it has precipitated is, or by pouring the reaction mixture into a material suitable for the catalyst system Is solvent, but is not a solvent for the reaction product. For a change you can also precipitate the copper as an insoluble compound and before isolating the reaction product from filter off the solution, or a gelling agent is added which inactivates the copper. After if the reaction product has precipitated, it can be overturned any number of times for purification. Last will it is filtered and washed free of any remaining impurities. After drying the resin can be processed by compression molding, extrusion molding, or melt spinning, or one can Dissolve it in solvents to produce solutions that are useful in the production of coatings, Find fibers or adhesives use.

Modifiers for the reaction can be added to the reaction mixture in order to produce products with to obtain improved properties over those made without modifying agents.

Particularly suitable modifiers are: anion exchange resins, especially those that contain tertiary amine groups as an active ingredient, nitroaromatics, such as mono-, di- and trinitrobenzenes, mono-, di- and trinitrophenols; Peroxide deactivators, like heavy metals and their oxides; Adsorbents such as activated charcoal, Kresel gel or clay.

Although the anion exchange resins are insoluble in the reaction mixture, they are apparently somehow effective with the copper amine complex, likely as promoters or cocatalysts. The use of an anion exchange resin as a modifier is particularly useful when that is the case oxidizing phenol either in one or both ortho positions to the phenolic hydroxyl group is unsubstituted. As stated above, this reaction would usually be more specific using run tertiary amines. But it was found that anion exchange resins, which are insoluble Carrier-bound dialkylamino groups contain, in some respects, a beneficial effect on exercise the course of the reaction similar to those obtained with the specific amines. If z. B. Orthocresol in pyridine solution with a copper (I) chloride catalyst in the presence of an anion exchange resin is oxidized, which contains dimethylamino groups on a styrene divinylbenzo support, so will a soluble polymer is formed. If the same reaction is carried out in the absence of the anion exchange resin or the special amine catalysts, complex products are formed that are not so are useful. As far as is known, these resins do not have to meet any requirement other than that they contain anions can absorb, which is a characteristic of all anion exchange resins. Typical examples of such Anion exchange resins that can be used are amine modified or quaternized Polymers, e.g. B. crosslinked styrene divinylbenzene polymers, Styrene glycol dimethyl acrylate polymers, aniline formaldehyde resins, Aryl polyamine formaldehyde resins, phenol formaldehyde resins, urea formaldehyde resins, and Melamine-formaldehyde resins modified with amines. Those compounds that are reaction products from formaldehyde can be modified with amines as long as they are in the methylol state are. All compounds can be chloromethylated and then reacted with amines. Such Fabrics are quickly available and commercially available. Because primary and secondary amine groups with oxygen react, the amine group should be tertiary or quaternized, so that the effectiveness of the resin during the oxidation reaction is not impaired.

The effect of adding nitroaromatics, such as picric acid and nitrobenzenes, to the reaction mixture appears to lie in the destruction of by-products or the prevention of their formation. These would react with the main product to form impure material with less desirable ones Properties. The use of nitroaromatics is particularly advantageous in the manufacture of resins with a much lighter color than this is possible under the same reaction conditions without them is. Their use is particularly desirable when using tertiary amines as a catalyst, which are not resistant to oxidation, d. H. discolor easily in the presence of oxygen, e.g. B. aliphatic tertiary amines. Since the nitrophenols can form complexes with the copper amine catalyst, Sufficient catalyst should be used to allow an excess over that of the nitrophenol present responsive is guaranteed.

In order to prevent the accumulation of peroxides, which can cause attack on the phenol at an undesired position on the aromatic ring, peroxydcactivators can be used, ι. B. selenium, silicon, lead, mercury, copper, silver, gold, nickel, palladium, platinum, cobalt, rhodium,

Iridium, iron, ruthenium, osmium, manganese, chromium, molybdenum, tungsten, vanadium, niobium, cerium, thorium, as well as their oxides or salts. Other peroxide deactivators are on pages 467 to 501 of »Hydrogen Peroxides «by S c h u m b, Satterfield & Wentworth, Rheinhold Pub. Corp., New York, N.Y., 1955.

The reaction can also be carried out in the presence of adsorbents, which tend to produce by-products to remove which are present in a small amount and adversely affect the reaction be able. Examples of these adsorbents are: activated carbon, silica gel (including xerogels, aerogels, Silica, etc.), clay and magnesium silicate.

It has also been found that the quality of the polyphenylene ethers can be improved if a organic, sulfur-containing compound is added, resulting in a solution of the product at the end of the oxidation reaction also has reducing properties. Typical such compounds are thiourea and its derivatives. These substances not only remove all copper from the product, they remove it also destroy any color-forming by-products that may be undesirable in the final product. This Color formers appear to be diphenylquinones. These colored fabrics are chemical by-products and no parts of the polymer molecule as they can be removed from the polymer. However, if a If a colored end product is desired, one must purposely add hydroquinones to the reaction mixture or add quinones to achieve a controlled, desired color in the end product, as part of of the polymer film cannot be removed. Typical hydroquinones that can be used for this purpose are: Hydroquinones, catechol, substituted hydroquinones, such as toluhydroquinones (methylhydroquinone), halogen-substituted ones Hydroquinones, such as tetrachlorohydroquinone, the naphthohydroquinones, the dihydroxyanthracenes or the dihydroxyphenanthrenes.

The following basic procedure is used in the examples below:

In general, the oxidations are carried out at room temperature carried out by adding oxygen to a vigorously stirred solution containing the phenol and a Copper (I) salt contains, is introduced so quickly that not all can be absorbed. The latter are in dissolved in a suitable solvent, which is usually the amine or the amine with a to-Die The following examples illustrate the oxidation of 2,6-disubstituted phenols.

In a
phenol

example
Reaction mixture,

CH ₃

the 5 g of 2,6-methyl-

OH

CH ₃

Containing 1 g of Cu ₂ Cl ₂ and 100 ml of pyridine, oxygen was passed in for 10 minutes. During the reaction, the temperature rose to a maximum of 7O ⁰ C. No water was removed. The product was precipitated by pouring the reaction mixture into about 500 ml of dilute hydrochloric acid and separated by filtration.

The product, poly (2,6-dimethyl-1,4-phenyl) -ether, is characterized by repeating structural units the formula

It was obtained in a practically quantitative yield.

The molecular weight of the product was for the light scattering method in the range of 300,000 to 70000Ü and it did not melt at 300 ⁰ C. The powder obtained by precipitation could be compression molding, calendering or extrusion into a unitary piece at pressures of 140 kg / cm ² at 240 ⁰ C. From 10% strength solutions of the polymer in each of the following solvents, 1. benzene, 2. toluene, 3. xylene, 4. tetrahydrofuran, 5. pyridine, tough films could be produced by brushing on a glass surface and peeling off after the solvent had evaporated . These films were oriented by stretching and cold drawing. By extruding a saturated lo

Solution of the polymer in xylene. In air, fibers were additional suitable solvents. The oxygen 50 is made. This could also be done by stretching

is introduced into the reaction mixture until no more heat is developed. The temperature rises first and then begins to fall until the reaction is complete. Is the reaction product either soluble in the reaction mixture or partially soluble, the latter becomes about 5 times the volume of a nonsolvent for the Polymers added. So much for the nonsolvent When dilute hydrochloric acid is present, enough acid is used to neutralize any amine present in the reaction mixture. When If aqueous hydrochloric acid is the nonsolvent, it is somewhat abnormal, although more dilute or Concentrated solutions can also be used and cold-draw orientate.

B e i s ρ i e I 2

If air is used instead of oxygen, the reaction proceeds more slowly and the one obtained The maximum temperature is lower because the heat is dissipated by the inert nitrogen. If z. B. Air into a well-stirred mixture of 5 g of 2,6-dimethylphenol, 1 g of copper (I) chloride and 125 ml of pyridine is initiated, the temperature rises from 30 to 43 ° C. within 14 minutes and then falls during the next 9 minutes to 36 ° C. After this time, the reaction mixture was in Poured in methanol and then thoroughly

nen. The precipitated reaction product is then washed off, which is a sufficient amount filtered. As far as the original reaction product contains I2 molar hydrochloric acid, the methanol becomes acidic borrowed reaction mixture is insoluble, it will hold out. The yield was 4.9 g versus 4.92 g Filter removed. according to the theory, poly (2,6-dimethylphenyl-1,4) -ether,

which has the same repeating unit as above. It had a true viscosity of 0.625.

Example 3

The true viscosity and physical properties can be varied by controlling the amount of oxygen absorbed in the reaction mixture. In order to measure the amount of oxygen actually absorbed, it was necessary to use a closed system with a suitable storage vessel for the oxygen and a suitable leveling device to keep the whole system at atmospheric pressure. Two gas burettes, which were connected to a leveling ball by a series of stopcocks, an oxygen source, a manometer and the reaction vessel provided a suitable closed system in which one gas burette could be recharged with oxygen while the oxygen from the other burette was added was fed. Using this system, two batches of 50 g each of 2,6-dimethylphenol were oxidized in the presence of 1 g of copper (I) chloride and 500 ml of pyridine. The phenol was not added until the other materials were saturated with oxygen. The reaction temperature was maintained at 3O ⁰ C by the reaction vessel was immersed in a constant temperature bath partially. After 60 minutes, 102% of the theoretical amount of oxygen required to oxidize all phenols to polyaryl ether had been absorbed. At this point the reaction mixture was poured into water to precipitate the product. It was washed out with dilute aqueous hydrochloric acid until no more odor of pyridine could be detected, then washed with water. The polymer was digested six times in acetone, followed by dissolving in chloroform and precipitating in methanol. Both lots were combined by dissolving in chloroform, mixed and precipitated in methanol. This product is mixed up as product A in Table I. Product B was prepared in the same way as product A, but the reaction was continued for 70 minutes in the case of the 1st batch, which contained only 40 g of phenol, and in the case of the

ίο 2nd batch containing 50 g phenol for 90 minutes. In both cases 107% of the theoretical amount of oxygen was required for the oxidation of the phenols is absorbed. Product C is a polymer that is produced by a two-step process would. The procedure was the same as for product A, only 2.5 g of cuprous chloride was used. After 3.5 minutes, about 50% of the theoretical amount of oxygen had been absorbed. The reaction was stopped by adding so much hydrochloric acid that the solution became acidic. The Polymers were extracted from the aqueous solution with benzene and washed with 5% aqueous sodium hydroxide solution, to remove any unreacted phenol. The benzene solution was washed with water and dried with a desiccant. The benzene was withdrawn and a brittle polymer of low molecular weight isolated. 29 g of this low molecular weight polymer were dissolved in 620 ml of pyridine containing 3.1 g of copper (I) chloride and followed for 1 hour by the same procedure as oxidized in the first step. Product C was made from the reaction mass by the same procedure like product A isolated.

The physical and electrical properties of these three polymers are compared in Table I.

Table I.
Physical properties of poly (2,6-dimethylphenylene-1,4) ether

A. B. C. True viscosity 0.50
20,000
230 to 250
1.07
1 099 0.97
45,000
250 to 270
1.07
1 225 1.45
70,000
270 to 290
1.06
1 064 Approximate molecular weight
(after osmotic pressure)
Optimal pressing temperature, ⁰ C
Density (pressed film) 469 875 1 113 Ultimate tensile strength (kg / cm ² ) at
25 ° C 203 770 1 064 150 ⁰ C 357 686 175 ° C 72 81 64 200 ° C 71 133 170 Elongation, %, at
25 ° C - 53 167 230 150 ⁰ C 140 200 175 ° C 2.6
0.0006
! ■ H) ¹⁸ 2.60
0.0007
6 ■ 10 ¹⁷ 2.60
0.0008
1 ■ Ί0 » ¹ 200 ° C Electrical Properties ,
Dielectric constant 25 ° C
(60 Hz) tang f> (60 Hz), Specific direct current resistance
(Ohm cm)

continuation

Specific alternating current resistance

(Ohm ■ cm)

Dielectric constant 175 ° C

(60 Hz)

tang δ (60 Hz)

Specific DC resistance

(Ohm ■ cm)

Specific alternating current resistance

(Ohm cm)

1 · 10 ¹³

2.60 0.0034

9 · 10 ¹³ 5 · 10 ¹²

Are these three polymers in a saturated steam at 150 ° C (4.7 atm pressure) for 3 weeks exposed, the true viscosity is the same as before the test, from which it is found that the polymers not subject to hydrolysis. This resistance is also determined after the polymers have been used for 3 weeks heated to 175 ° C in a nitrogen atmosphere. Heating to this temperature in oxygen causes crosslinking of the polymer and some oxidation of the alkyl side chains.

B e i s ρ i e 1 4

Other tertiary amines can be used both as part of the catalyst and as solvents for the reaction be used. The procedure of Example 1 was repeated, only quinolines, N-methylmorpholine, a-picoline, 2,6-lutidine, tri-n-propylamine, triethylamine and Ν, Ν-dimethylbenzylamine in place used by pyridine. In each case the molecular weight and color of the final product changed with the amine used. The lightest colored products were with the monoarylcyclic Amines, ζ. B. pyridine, α-picoline and 2,6-lutidine. Aliphatic amines are poor solvents for the reaction, and so they are in theirs Use obtained products lower than with other amines.

45

55

Example 5

The reaction product can be derived from the reaction mixture from Example 1 except for that used there Dilute hydrochloric acid can also be precipitated by other means. The procedure of Example 1 was repeated, only methanol, ethanol, isopropanol and acetone were used as precipitants instead of the diluted hydrochloric acid is used. In either case, the product failed just as quickly and exactly like that easily filtered off like the product from Example 1. The special precipitating agents had no noticeable influence on the physical or chemical properties of the product. Although not necessary, it is usually desirable to have enough normal add aqueous hydrochloric acid for precipitation in order to neutralize the amine and the copper (I) salt to inactivate. This step aids in the formation of a cleaner product.

Example 6

Pyridine can be combined with other solvents to make a polymer. The results shown in Table 11 show that the molecular weight of the polymer formed is from the 2 x 10 ¹³

2.55
0.002

2 · 10 ¹³
4 · 10 ¹²

1 · 10 ¹³

2.60.
0.002

9 · 10 ¹⁴
5 · 10 ¹²

depends on the specific solvent system used. Propanol is a solvent for the starting materials but not for the reaction products. The molecular weight is the softening point and directly proportional to the true viscosity of the polymer.

Oxygen was passed in for about 10 minutes into reaction mixtures which contained 10 parts of 2,6-dimethylphenol, 1 part of Cu ₂ Cl ₂ and the stated amounts of pyridine and n-propanol. During the reaction period the temperature of the solutions rose from 30 ° C to maximum values in the range 60 to 70 ° C. No water was removed during the reaction, in which some precipitate was formed. The reaction products were completely precipitated by pouring into ethanol containing hydrochloric acid and separated off by filtration. The products had the same repeating unit as in Example 1, but the molecular weight decreased with increasing amounts of propanol, as the results of Table II show.

The true viscosity is determined by dissolving the polyaryl ether in a suitable solvent and measuring the relative viscosities over a certain one Concentration range determined. If a suitable solvent has been used, it gives a straight line plotting the viscosity-concentration values. By extrapolating this line the value of the true viscosity is obtained from the concentration.

Table II

Parts by weight
solvent used n-propanol Softening
Point Real
viscosity Pyridine 93.8 of the product 6.2 87.8 219 ° C 0.21 12.2 54.5 235 ° C 0.23 45.5 melts 0.64 at 300 ⁰ C not

Example 7

Molecular weight is not only influenced by the ratio of solvent to pyridine, but also the specific solvent catalyst concentration and the reaction time. Table III shows the Results obtained with different solvents as well as with different amines. In in all cases the oxidized phenol was 2,6-dimethylphenol.

109 622 339

CuCl 1 17th Pyride in 1 420 485 toluene Temperature "C
Start-max. 70 18th I. Real
viscosity (G) '(300) 2 1 Amine Pyridine Table III o-dichlorobenzene 50 73 reaction time 0.90 Phcno (ml) (50) solvent (50) (Minutes) (G) 1 1 Pyridine (ml) / f-methoxyethanol 30th 75 about 10 0.87 50 (50) (50) 1 1 Pyridine t-amyl alcohol 30th 72 5 0.67 10 (50) (50) 1 Pyridine / ί-acetoxyethanol 30th 74 4th 0.97 10 (50) (50) I. Pyridine Benzonitrile 30th 80 5 0.43 10 (50) (50) 1 Pyridine Dimethylformamide 30th 44 12th 0.48 10 (20) (120) 1 Triethylamine ß-phenoxyethanol 30th 50 4th 0.49 10 (100) (100) 1 Dimethylstearylamine Dichlorobenzene 36 39 4.5 0.35 10 (0.1) (100) 0.1 Dimethylstearylamine Dichlorobenzene 24 37 27 0.12 5 (1,0) ' (100) + 10 ml 0.1 Dimethyl sulfoxide 26th 41 0.78 5 Dimeth} istearylamine o-dichlorobenzene 40 (D (100) 240 5 0.1 t-amyl alcohol 26th 0.44 (10) Dimethylstearylamine Tetrachlorethylene 38 104 5 (D (100) 0.1 t-amyl alcohol 25th 0.36 Dimethylstearylamine Xylene 50 (1) (100) 142 5 0.1 t-amyl alcohol 25th 0.47 (10) Pyridine t-amyl alcohol 62 158 5 (50) (80) 1 Pyridine t-amyl alcohol 26th 61 0.75 (30) (50) 1 Dimethyl sulfoxide 26th 7th 0.52 10 (50) Dimethylbenzylamine Nitrobenzene 50 7th 10 (30) (100) Tributylamine Nitrobenzene 31 48 0.59 (30) (100) Pyridine t-amyl alcohol 32 66 32 0.36 5 (50) (80) Pyridine CH ₂ CI ₂ 27 51 31 0.69 5 (75) (50) 31 8th 0.88 10 27 5

Example 8

This example shows that polymers of different molecular weights differ based on solubility of the special polymer in the system.

The procedure of Example 6 was repeated with the highest ratio of propanol to pyridine, only the portion of the polymer which precipitated out during the reaction was filtered off (precipitate I). Thereon

the mother solution was poured into dilute hydrochloric acid as in Example 6 and the precipitate was separated off (precipitate N). The mother solution separated from the precipitate II was left to stand overnight and the precipitate which had separated out was filtered off. Precipitation I had a softening point of 200 ⁰ C, precipitation of l45 II "CundNiederschlagIII of 120" C.

Example 9

Was the procedure described in Example 1 using other 2,6- or 2,4-substituted

The results are summarized in Table IV.

ated phenols, other copper (I) salts or others repeated tertiary amines, polyphenylene ethers corresponding to the starting phenol were obtained.

Table IV

Oxidized starting material
(G) Copper (l) salt
<g) Pyridine
(ml) Temperature "C
Start-max. 75 40 Reaction time
(Minutes) True viscosity 2,6-dimethylphenol Cu ₂ SO ₃ 100 90 30th 0.25 (10) (1) 85 64 2,6-dimethylphenol CuOH 125 30th 100 0.19 (10) (1.6)
O
Il 59 64 2,6-dimethylphenol Il
CuOCCH ₃ 100 30th 8th 0.35 (10) (1.2) 41 2,6-dimethylphenol CuClO ₄ 100 30th 12th - (1.6) 56 2,6-dimethylphenol CuBR 125 30th 81 0.91 (10) (2) 56 2,6-dimethylphenol CuN ₃ *) 150 30th 7th 1.13 (5) (D 56 2-methyl-6-ethylphenol CuCl 100 30th 8th 0.29 (5) (1) 42. 2,6-diethylphenol CuCl 100 30th 8th - (5) (D heated to 90 ° C 2-methyl-6-isopropylphenol CuCl 100 27 20th 0.24 (5) (D heated to 80 ^° C. 2-chloro-6-phenylphenol CuCl 40 153 - (10) (D 29 2-chloro-6-methylphenol CuCl 125 31 - (5) (D 25th 2-methyl-6-methoxyphenol CuCl 130 12th 0.27 (3) (1) around 2-allyl-6-methylphenol CuCl 125 giving 12th - (5) (D 2,4-dimethylphenol CuCl 100 9 - (10) (D

*) The amount was calculated on the basis of the raw material. The connection cannot be isolated because it is dry is explosive.

The first six phenols form poly (2,6-dimethyl-50thylphenyl-1,6) -ether. The latter compound would have folphenyl-1,4) -ether with the following repeating unit:
Unit:

O-

CH ₃

CH ₃

while the other phenols depending on the form: poly-2- (methyl-6-ethylphenyl-1,4) -ether, poly-2,6-diethylphenyl-1,4) -ether, Poly (2-methyl-6-isopropylpheny I -1,4) ether. Poly (2 - chloro - 6 - phenylphenyl, 4) ether, Poly (2-chloro-6-methylphenyl-1,4) ether, poly (2-methyl-6-methoxyphenyl-1,4) ether, poly (2-allyl-6-methylphenyl-1,4 )-ether and poly (2,4-dimen-

while the other substances all have repeating units, similar to poly (2,6-dimethylphenyl-1,4) -ether, however, their substituents correspond to the name.

In some cases it may be desirable to produce a polyphenylene ether with a specific color. This can be done by adding quinones or hydroquinones to the reaction mixture before the oxy-

dation, creating a product that has a built-in color that is made by solvents cannot be removed. This color reaction can be modified to give different shades receives or prevents it entirely. Just like phenols with large voluminous groups in the The ortho position of the ring does not contain polyphenylene ether

can form, so can quinones and hydroquinone, that carry large, voluminous substituents on the ring, do not form colored products. Quinones and Hydroquinones in which all ring positions are substituted can also not contain colored compounds when the substituent is not halogen.

Example 10

The following examples explain the possibilities of the reaction product. In some cases

the preparation of polyphenylene ethers from Phe- the reaction had to be heated to initiate it,

nolen that have more than one reactive position in cases where a solid modifier

to have. The general procedure was as was enclosed, this was done prior to the precipitation of the

Game 1 with respect to the preparation of the reaction 15 polyphenylene ethers filtered out of the solution. the

Mixture, the introduction of oxygen and the ISO results are summarized in Table V.

CuCl Amine Table V Modification means Tcmpci ature C length of time Real
viscosity phenol (μ) (P) solvent Slarl Max. (Ρ) I. 2-benzyl pyridine (ml) 0.1 g 30th 45 91 0.1 Guiacol (5.2) Trichlorethylene Picric acid (10), I. 2-methyl (40) 0.1 g 70 - 310 0.2 phenol 6-undecyl pyridine s-tetrachloroethane Picric acid (75) (5) (150) 1 2- (5-nonyl) - - 26th 50 180 0.39 0 cresol pyridine Nitrobenzene (5) (6.2) (100) t-amyla alcohol 1 2-benzyl pyridine (10) - 150 - 155 0.11 o-phenylphenol (5.1) Nitrobenzene (K)) 1 s-collidine (125) - 91 - 111 0.06 m-phenyl (25 ml) Tetrachloroethane phcnol (250) (50) 1 2-amyl pyridine 4.2 MgSO ₄ 29 47 86 0.26 o-K resol (3) Tetrachloroethane (anh) (75) 1 2-amyl pyridine (15) 4.29 MgSO ₄ 29 46 107 0.42 o-cresol (3> Tetrachloroethane + ig (75) (125) 5% platinum on coals material I. 2- (5-nonyl) pyridine 5% Pt 28 32 1240 0.42 o-cresol (6.2) Tetrachloroethane carbon (5) (125) (D I. 2-amyl pyridine 5% Pt 30th 50 83 0.48 o-cresol (3) Tetrachloroethane carbon (7.5) (125) (D 2 2-ethyl pyridine 30th 98 9 0.14 o-cresol 100 ml - (15) 3 2- (5-nonyl) - - 50 - 94 0.3 o-cresol pyridine Phenylcellosolv (15) (18.5) (70) Benzonitrile I. 2-amyl pyridine (30) 5% Pt 50 - 145 0.24 o-chlorophenol (3) Tetrachloroethane carbon (15) (125) (D Phenylcellosolv I. 2-amyl pyridine (65) 5 ml (2% iso- 95 135 0.25 o-chlorophenol (3) Tetrachloroethane propyl (15) (125) vanadate in Isopropyl Phcnylcellosolv nol) (65)

CuCl
(G) 23 Amine
(G) 1 420 485 r Modifier ' 24 / 98 nature 'C
Max. length of time Real
viscosity 1 2-amyl pyridine 4.2 g MgSO ₄ 40 114 0.44 (3) continuation + ig Tem | iei
begin phenol
(G) solvent
(ml) 5% palla 29 o-cresol s-tetrachloroethane dium on 90 (75) (125) carbon 1 2-amyl pyridine - - 60 0.12 (3) o-chlorophenol Tetrachloroethane (15) 3 2- (5-nonyl) - (125) - - 137 0.21 pyridine Phenylcellosolv (18.5) (65) o-chlorophenol Phenylcellosolv (15) (70) Benzonitrile (30)

The reaction product from Guiacol (o-methoxyphenol) was poly (2-methoxyphenyl-1,4) ether, from Phenol = polyphenyl-1,4-ether, from o-cresol = poly- (2-methylphenyl-1,4) -ether, from o-phenylphenol = poly (2-phenylphenyl-1,4) ether, from m-phenylphenol = Poly (3-phenylphenyl-1,4) -ether and from ο - chlorophenol - poly - (2 - chlorophenyl -1,4) - ether. All these substances consist of recurring units with the same general structure:

in which the numbers indicate the position of the substituents.

As mentioned earlier, true viscosity is a measure of molecular weight. However, it provides more relative as well as specific measured values. In ¹ Table VI some of the ratios measured are given:

Table VI Polyaryl ether True viscosity

Molecular weight according to osmotic

pressure (Chloroform -.25'C)

Light scattering

Poly (2,6-dimethyl-1,4-phenyl) ether
Poly (2-methyl-1,4-phenyl) -ether ...
Poly (1,4-phenyl) ether ....

Poly (2-phenyl-1,4-phenyl) ether
Poly (2-chloro-1,4-phenyl) ether 0.185
2.04

0.19

0.45

0.20

0.115

0.095

0.085

0.070

0.15

0.24

16 500
165,000
44,000
63,000
80,000
58,000
41,000
28,000
18 500
47 700
82,000

114000

678,000

382,000

2,150,000

6,100,000

710000

66,000 1,220,000 5,400,000

Because of their excellent physical, mechanical, chemical, electrical and thermal Properties There are many and varied uses for the polymers of this invention. So you can z. B. can be used in powder molding compositions, either alone or with various fillers mixed, such as sawdust, diatomaceous earth, carbon black or silica, for the production of pressed parts, such as Spur gears, helical gears, worm or bevel gears, locking devices, bearings, cams, Butt parts, sealing rings, valve seats for high pressure oil and gas systems or other flowable Chemicals that must be resistant to chemicals. They can be used for the production of pressed, calendered or extruded articles, films, coatings, threads, fibers and tapes use. They have a “large area of application as plates, rods or strips and are can also be used for electrical purposes, such as cable clamps, terminal blocks, pads for electrical purposes Circuits or as components of dynamo-electric machines that work at high temperatures.

By suitable means such as dissolving or suspending in a suitable solvent and the following Applying to a surface from which the polymer is after evaporation of the solvent removed, by calendering or extrusion, films can be made from these materials. This Films (oriented or not) can be used as linings for metal and plastics, containers, Covers, closures, electrical insulating tapes,

109622/339

Tapes, pipe and wire wraps. Where a surface is desired that is excellent If the polymer possesses properties, these can be applied to any suitable substrate as a coating material apply in the form of a solution or suspension. They can be used as an encapsulation material, for electrical purposes Insulation, e.g. B. use as wire enamel. They can be put in a precipitation bath as a melt, solution or suspension or extrusion of the evaporation medium. Leave the fibers so produced (oriented or not) process into fabrics that can be used in many ways, e.g. B. as filter cloths where high chemical and heat resistance is desired. Make their excellent electrical properties Laminates made from this material can be used for electrical components, such as slot wedges in the armature of a door Electric motor, documents for printed circuits, switchboards for electrical devices, radio and television sets, small stamped electrical parts, transformer end plates, spacers for transformer end plates or spacers for transformer coils. The polymers can also be made with different Fillers or modifiers are mixed, such as dyes, pigments, stabilizers and plasticizers.

Claims (2)

Patent claims: 1. Process for the production of 'polyphenylene oxides, characterized in that one of a tertiary amine and one copper amine complex produced therein soluble in copper (I) salt in the presence of oxygen Temperatures not exceeding 100 "C with phenols of the general formulas or converts, in which X is a hydrogen, chlorine, bromine or iodine atom, R 'is a halogen atom or R and R a hydrogen atom, a hydrocarbon, hydrocarbonoxy, halocarbon or a halogenated hydrocarbon oxy radical, the aliphatic halogenated substituents at least 2 carbon atoms between the halogen atom and the Phenolic nucleus have all aliphatic substituents on the one attached to the phenolic nucleus Carbon atom carry at least one hydrogen atom and R and R 'in the general formula II not both a halogen atom or an aryl, hydrocarbonoxy or halohydrocarbonoxy radical may be. 2. The method according to claim 1, characterized in that there is used phenols in which R denotes a methyl or phenyl radical.