DE1720829C3 - Process for the production of poly (1,4-phenylene ethers) - Google Patents

Description

where R has the above meaning, distilled off.

2. The method according to claim 1, characterized in that the heating in the liquid phase under Use of solvents takes place in which the phenoxyphenol used is soluble, and the have a sufficiently high boiling point to achieve the desired reaction temperature be able.

3. The method according to claim 1 and 2, characterized in that the heating in oxygen-free Atmosphere takes place.

4. The method according to claim 1 to 3, characterized in that the liquid phase consists of a Solution of a 4-phenoxyphenol in terphenyl, chlorinated biphenyl ether or mixtures thereof and that the reaction temperature is in the range between 300 ° C and the boiling point of the Solution lies.

5. The method according to claim 1 and 2, characterized in that the 4 - phenoxyphenol in oxygen-containing atmosphere is heated.

6. The method according to claim 1 to 5, characterized in that the liquid phase at least for the latter part of the heating in a thin layer and that the molten polymer then heated in an oxygen-containing atmosphere until solidification.

Polyphenylene ethers as a class represent an interesting group of polymers. They are, for example in U.S. Patents 33 06 874 and 06 875 and in a number of articles in J. Polymer Science, 58, 581-609 (1962). You can through an oxidative coupling reaction of various phenols in the presence of a complex of an amine and a basic one Copper (II) salt can be produced. The hydrogen of the hydroxyl group of the phenol and the hydrogen or the halogen on the benzene ring is removed in the formation of the poly (1,4-phenylene ethers).

It has surprisingly been found that certain phenoxyphenols are easily polymerized can, if heated to a temperature at which the monocyclic phenol, that of the terminal Corresponds to the phenoxy group of the phenoxyphenol used, distilled off from the reaction mixture will. The phenoxyphenols that can be polymerized by the process according to the invention, have the formula

in which η is an integer of 1 or 2 and R is door Is hydrogen, hydroxyl, methoxy or 4-hydroxyphenoxy.

The invention therefore provides a process for the preparation of poly (l, 4-phenylene ether) which characterized in that a 4-phenoxyphenol of the general formula

in which η is 1 or 2, and R denotes hydrogen, hydroxyl, methoxy or 4-hydroxyphenoxy, heated in the liquid phase to a temperature at which the monocyclic phenol of the formula corresponding to the terminal phenoxy group of 4-phenoxy · phenol

OH

where R has the above meaning, distilled off.

The phenoxyphenols falling under the above formula are

4-phenoxyphenol,

4- (4-hydroxyphenoxy) phenol,

4- (4-methoxyphenoxy) phenol,

1,4-bis (4-hydroxyphenoxy) benzoL

1- (4-methoxyphenoxy) -4- (4-hydroxyphenoxy) -

benzene and
4,4'-bis (4-hydroxyphenoxy) diphenyl ether,

also known as bis-4- (4-hydroxyphenoxy) -f> henylether referred to as. Of these, the first two phenoxyphenols are commercially available, while the the rest of these two phenols or other readily available materials by known methods can be produced. The methoxy derivatives can by methylation of the corresponding Phenol e.g. B. be made with dimethyl sulfate. The other non-methylated phenols can after the Ullmann reaction. For example, the last is phenol in the list above can be prepared from bis-4-bromophenyl ether and the potassium salt of hydroquinone monomethyl ether.

It can be easily seen that 4-phenoxyphenol is a dimeric oligomer and 4- (4-phenoxyphenoxy) phenol is the trimeric oligomer of poly (1,4-phenylene ether) and the other phenoxyphenols thereof Are hydroxy and methoxy derivatives. Two molecules react in this thermal polymerization reaction of these dimers or trimers with each other in a stepwise reaction in which 1 molecule of Phe-

nol and 1 molecule of the next higher oligomer are formed, ie 2 molecules of the dimer 4-phenoxyphenoi form 1 molecule of phenol and one molecule of the trimer, ie 4- (4 ~ phenoxy phenoxy ) phenol. In the next step, 1 molecule of the i and 1 molecule of the dimer react again

wherein smooth cast films of the polymers are formed of 25O ⁰ C to its boiling point.

The use of this solvent is necessary when using 4-phenoxyphenol itself as a starting material is used and in oxygen-free Atmoll Di Mterial is like that

Trimers and 1 molecule of the dimer should be heated under renewed sphere. This material is like that

Rildune of 1 molecule of phenol and 1 molecule of the volatile that it evaporates in the absence of it

Tetramers. It is also possible that 2 molecules of a solvent are heated before a lem-

Trimers with formation of 1 molecule of the dimer temperature is reached, which is sufficient to remove the phenol.

and distill 1 molecule of the tetramer in the same way. By using these solvents

react as if the trimer is the starting material, preventing this product from evaporating,

These 'two reactions will continue until a temperature at which the phenol will readily degrade

until finally no more phenol distilled off from the solution reaction mixture, reached and the Poiy-

can be distilled. When in oxygen-free · (1,4-phenylene ether) is formed. The usage

Atmosphere is heated, this reaction is limited 15 this solvent is also with the other ais

Even if a poly (1,4-phenylene ether) with phenoxyphenoies used by starting materials

incrementally up to 20 phenoxy units, d. H. with one of the above general formula expediently.

Value of 20 for «in the form] Ji, is formed. The solvent also suppresses the evaporation

If the reaction takes place in air or in one of these phenoxyphenols from the ^ eaKtions-

another oxygen-containing atmosphere stirred through the mixture, which increases the yield of polymer

will and also in cases in which this becomes through Erhtaen. "-", "" "- ht

_{polymers obtained in an} oxygen-free atmosphere. When the maximum polymer yield is desired

If the product is heated in oxygen, the poly-

The merization reaction continues until oxyphenols are closed in a solvent with exclusion

S an insoluble, tough, hard polymer gebil-> _S ,, of oxygen to nuclear phenolic more ^ ^ of the solution

that is no longer fusible. When one is distilled off. At this stage ^ ^tta l * ^ 2n

HümTe layer of these materials in the presence of an average of 14 to 20 Phenoxyemhe th

Oxygen-containing gas is heated, these are in the polymer molecule. This polymer can «ohert

eSteien slides are very flexible. You can end up in by adding a nonsolvent to the reaction mixture

Only webs or tapes are produced which are added or the reaction mixture, but not

K use the most varied of purposes ^^^^^^^^

The temperature required to carry out this in an oxygen-containing atmosphere R. Reaction is applied, must be so high that air, at a temperature at which the polymer in the the phenoxyphenoi, which is the terminal phenoxy, 5 liquid state, after eir ,, approximately present

m% hr ^{last phen} - ^{phenols corresponds to} ' issJ ^^ ss ^ st cm SS-

ie the formula ^^ ^. ^ ^^ _{If the solution at this} r

jT > temperature is maintained, the given

R ^ ^ OH 40 foils existing solvents, and the polymer

^N «= ^/ gradually solidifies and turns into an insoluble poly

merisat about. Since the polymer is insoluble, can

where R has the meaning already mentioned, the molecular weight of the end product or its is distilled off from the reaction mixture. In general, the actual chemical structure
In the meantime, this temperature is in the range of 250 45 den. Insolvency can affect one
mine lies ^ _{reaction in the} oxygen-containing state of the polymer, * ■ B- _; Mole <

will, and usually at or on

set phenoxyphenoi is soluble and uit uuui have a sufficiently high boiling point to be able to achieve the desired reaction temperature. As a solvent Terphenyl, the various halogenated derivatives of Biphenyl and biphenyl ethers, especially the chlorinated biphenyls and chlorinated biphenyl ethers, or their mixtures. The solvents are readily available commercially and are particularly useful because they when hot are solvents for the polymeric products to the point where the polymer is becomes insoluble in all solvents. When the solutions of the polymers in these solvents are cast in thin layers, the solvents easily evaporate at temperatures

hintci dem

in brackets.

the theoretical value

General procedure

The general procedure to be followed when only in an oxygenated atmosphere is heated, is carried out as follows: The Phenoxyphenoi is evenly on the to be coated Surface applied when heated in the absence of a solvent, or the phenoxyphenoi and the solvent are placed in a container, the bottom of which is the surface to be coated and is surrounded by the side winds. The

Phenoxyphenol is produced in an oxygen-containing atmosphere, ζ Β. Air, heated, which allows the volatile constituents to evaporate. The temperature to which heated is high enough to completely evaporate all of the solvent used, however not high enough to char the polymer film formed. Temperatures just above the melting point of the initially formed polymer film are suitable. At the point where essentially all the solvent has evaporated, remains one thin liquid, which becomes more viscous with further heating and eventually turns into a non-flowing one Solid passes over. At this point the polymer is tough, flexible and can be removed when the foil has been applied to a highly polished, inert surface.

In a series of experiments in which the heating was carried out in a tube furnace in which the temperature could be precisely controlled and measured, it was found that the optimum temperature was between 250 and 300 ° C. Temperatures above 300 ° C. during the distillation of the phenol resulted in an excess of the phenoxyphenol used distilling off, so that the polymer yield was reduced. At temperatures below 250 ° C the reaction was too sluggish for practice.

In a further series of tests, which was carried out at 275 C, the influence of the atmosphere determined using a covered container that used that as the starting material Phenoxyphenol contained, over which a controlled atmosphere in an amount of 28.3 l / h: geleitel would. When using pure nitrogen, no phenol was distilled from the container. With increasing The amount of oxygen in the nitrogen was the optimum yield of polymer in the range of 25 up to 50 percent by volume of oxygen is achieved. The yield increases above 50 percent by volume of oxygen admittedly further, however, the flexibility of the polymer product deteriorates. To achieve optimal Flexibility, therefore, the oxygen-containing gas should preferably not be more than 50 percent by volume of oxygen contain. However, if thicker cast parts are desired, e.g. B. when using the material as a potting compound, where flexibility is not required, higher amounts of oxygen can be used in the Oxygen-containing gas may be included. Air containing about 20 volume percent oxygen is suitable and is because of its low cost and its negligible influence on the yield of polymer generally used.

When the initial heating is carried out in a substantially oxygen-free atmosphere and the final step in an oxygen-containing atmosphere, the following general procedure applies: A distillation flask with a wide outlet port is fitted with a heating element for the vertical column. The phenoxyphenol and solvent are added to the still and heated under nitrogen. The heating element on Ausflußarm is maintained at a temperature of 210 to 22O ⁰ C, while the distillation flask is heated to the reflux temperature of the solvent used. The heating is stopped when no more phenol is distilled off. The hot solution can be used directly for casting films, which are then heated in an oxygen-containing atmosphere, or the polymer can be isolated in the manner already described.

In the described in the following examples, experiments trichlorobiphenyl was used as solvent and heated to the distillation flask to the reflux temperature of 330 ^D C.

example 1

This example illustrates the use of air as an oxygen-containing atmosphere during of the entire heating. The general procedure was followed. The phenoxyphenol used and its weight, yield and analytical values for the polymer are given in Table I. 5 ml of trichlorobiphenyl were used as the solvent. It was heated to 275 ° C until the entire solvent is evaporated and the product initially present as a melt in a non-flowing solid was converted. Petri dishes made of glass, open to the air, were used as containers used. The films could easily be peeled off the glass. They were strong, flexible, and tough in all Insoluble in common solvents.

Table I.

Phenoxyphenol (wt.)

Ge analysis
weight
of the C
Polymers

(G)

4-phenoxyphenol

(2.0 g) 0.73 78.0 (78.2) 4.4 (4.3)

4- (4- phenoxyphene-

oxy) phenol (2.0 g) 0.8 78.4 (78.2) 4.5 (4.3)

4- (4-hydroxyphene

oxy) -phenoi (2.0 g) 1.13 77.7 (78.2) 4.3 (4.3)

4- (4-methoxyphene-

oxy) phenol (2.0 g) 0.88 77.5 (78.2) 4.3 (4.3)

4,4'-bis (4-hydroxy-

phenoxy) -

diphenyl ether (10g) 0.8 77.7 (78.2) 4.3 (4.3)

Example 2

In this process, the resulting atmosphere was initially heated in a practically oxygen-free atmosphere Polymers obtained and then heated in an oxygen-containing atmosphere, as in Example 1 described. Using the general procedure described above in which 10 g of the respective phenol and 100 ml of trichlorobiphenyl were used as solvents, this was the end the reaction mixture distilled phenol collected. Heating continued for about 6 hours, whereupon no more phenol distilled off from the reaction vessel. By further heating over beyond this time phenol was no longer formed and the molecular weight of the polymer was not elevated. After cooling to room temperature, the slurry obtained was dissolved in an excess of methanol poured and the precipitated polymer filtered off and washed. A molecular weight determination on the chloroform-soluble portion of the polymer II showed that it had a molecular weight from around 1900. This corresponded to a through

cut of 19 repeating units in the polymer.

The results obtained are shown in Table 11 below. For those specified for the first stage Results are the results for heating in the absence of oxygen were obtained, while the results for the final foils are given for the second stage, which were obtained after the specified amounts by weight of the products of the first stage with ι ο 5 ml Trichlorbiphenyi were heated, as in the example 1 described.

Table Il phenol Weight analysis H Phenoxy (Weight) of C. phenol Polymers (G) 4.3 1st stage phenol 3.8 (1) 76.2 (4.3) 4-phenoxy (3.2) (77.8) 4.2 phenol Hydro 4.9 (11) 75.7 (4.3) 4- (4-hydroxy chinone (77.8) phenoxy) - (4.2) phenol 3.5 «) 2nd stage 2.0 71.7 ') 4.0 I (2 g) 1.9 76.0 H (2 g)

¹ ) Contains some residual solvent.

As described above, the can by heating in a practically oxygen-free atmosphere obtained polymers for the production of films

35 on a backing from which they can be peeled off or used to make protective coatings for the backing. They can also be used, for example, to coat aluminum wire, the wire being dipped into the hot solution and then passed through a heating chamber, where the coating on the aluminum wire is converted into its final, insoluble, flexible state.

The products can be made with monobasic or dibasic acids, anhydrides or acyl halides esterified, forming esters that act as plasticizers for the general class of Polyphenylene ethers are suitable.

The solutions of the phenoxyphenols used as starting materials or those obtained by heating in Solutions of the polymers obtained in a practically oxygen-free atmosphere can be applied to an endless surface poured and spread out and then passed through a heating furnace in which they are placed in a endless film made of insoluble, flexible polymer, which is stripped from the casting surface will. These foils can be processed into strips and ribbons and then with a magnetic Film for use as an audio tape or with photographic emulsions for use as a photographic films are coated. These foils can also be used as slot wedges in the rotor of electric motors or used as dielectric insulation.

The hot solutions of the polymers produced by heating in a practically oxygen-free atmosphere can be obtained with a wide variety of fillers and also with modifying agents, z. B. stabilizers and plasticizers, mixed and then heated to the insoluble, meltable state will. They can also be used as pouring compounds, casting compounds and electrical insulating compounds.

«09610/92

Claims (1)

Patent claims: 1. Process for the production of poly- (i, 4-phenylene ether), characterized in that a 4-phenoxyphenol of the general formula in which η is 1 or 2, and R is hydrogen, hydroxyl, methoxy or 4-hydroxyphenoxy, heated in the liquid phase to a temperature at which the monocyclic phenol of the formula corresponding to the terminal phenoxy group of 4-phenoxyphenol