DE1903596A1 - Treatment of polyphenylthioethers - Google Patents

Description

Attorney file 17 639 * ^Ύι ΛΛ 196S

Be / Öch

Monsanto Company, 800 North Lindbergh Boulevard, St. Louis, Miss. 63166 / USA

"Treatment of Polyphenylthioethers"

This invention relates to the treatment of certain polyphenyl thioethers, which can also be referred to as polyphenylene sulfides, this term being polyphenylene sulfide includes in which one or more, but not all, sulfur atoms are replaced by oxygen atoms for To improve their color, their odor and their oxidation stability and to reduce their corrosiveness

Gaae 0-2399 -2-

909835/1543

against metals.

Because of the wide variety of uses of functional fluids, a particular one occurs Liquid a competition of many, both physical and chemical, for a required purpose Properties on. The toughest demands on fluids are met by hydraulic systems t aircraft gas turbines and, in the case of Sehmiersystemen, of gas turbines. As the speed increases and increase the working height of the jet-powered aircraft, also increase the lubrication problems because of the higher working temperatures and the higher bearing pressures that arise result from the increased thrust necessary to achieve the greater speeds and heights. In the same way as the working conditions that occur are becoming increasingly harder, so will the service life, of course abbreviated to the functional fluid.

The service life of any lubricant or any hydraulic fluid can be based on many criteria can be assessed, such as the extent of the increase in viscosity, the extent of corrosion on metal surfaces, that come into contact with the lubricant and the extent of the deposits in the machine. There were so far to improve lubricants various

Found ways to delay the effects or to 909836/1543

that shorten the duration of a lubricant, for example small amounts of other materials or additives can be added to the lubricants that influence one or more of the properties of the basic lubricant. Often, however, it is difficult to find additives, especially in the case of working temperatures, which have the minimum value for which they are added _? also beißgaai ^ oH and did not raise any further problems.

i £ s have been proposed lthioather Pci ^ ^ lieEi as compounds issterschiedlishen in Ti-sl-3E applications such eLs iirfepsi ^ metallic! liquids, damping fluids, s ^ ulistiselie lubricant uad Ätomreaktorkühlmittel can be used.

It was nunmeßi? found that the oxidative stability and hence the useful life of polyphenylthioethers can be substantially extended, even under the severe ones Conditions such as those encountered in jet engines and other devices at temperatures of the order of magnitude working from 5OO ° F (260 ° G) and higher if one brings such thioethers in the liquid phase into contact with a contact agent, namely alkali metals and a Oxygen releasing gas, d. H. Metals of group Ia of the Periodic Table of the Elements (see manual of Chemistry and Pfeysics, published by Chemical Rubber

CS9835 / 1543

BATH

Publishing Company, 4-2. Edition, pages 448 and 44-9) and Gases such as air or oxygen-enriched air can be used in the process according to the invention. Continue to be Significant improvements after the method according to the invention with regard to the color and odor of such thioethers and their corrosiveness certain metals is significantly reduced.

W It is therefore an object of this invention thereof, a method of increasing the oxidative resistance of PoIypheny.lthioäthern and preparations to provide. Another object is to provide polyphenylthioethers and preparations thereof which have reduced attack on metal and reduced engine build-up. Another object of this invention is to provide methods of improving the color and odor of polyphenylthioethers.

The term “polyphenylthioether ¹¹ , as used here, includes a compound or a physical mixture of compounds of the formula I.

909 835/1543

BADQflfQJNÄL

where Jl, A ^, Ap ^ d ·% each has an ehalogen with an atomic number from δ to 16 _s provided that at least one of the beds A, A ^, Ag and A * has an atomic number of, each of the radicals X, X ^ , Xg * ^ 3 ^and - ^X 4 is hydrogen, alkyl, haloalkyl, halogen, arylalkyl and / or substituted arylalkyl, L, m and η are integers, each with a value from 0 to 8 and a is an integer bit one Value from 0 to 1 with the proviso that when a is »O, β is an integer with a value of 1 to 2. Typical examples of alkyl and substituted alkyl groups are given below. Examples of such polyphenyl thioethers are:

90983571543

bath

-6-

where m is an integer from 0 to 6,

III.

where A. and A * are oxygen and / or sulfur

where ζ and y are integers from 0 to 3 and the sum from χ + y is from 1 to 6 and A and A * are each oxygen and / or sulfur, but at least one of A and A ' Sulfur is.

Typical examples of folyp & tnylthioethers. are:

2-Paenylaer capto-4'-phenoxydiphenylsulphide 2-Phenylaercapto-3 ^l -phenoxydiphenylsulphide 2-phenoxy-3-phenylmercaptodiphenylsulphide 3-phenoxy-4 * -phenylmercaptodiphenylsulphide

909835/1543

-7-

2-phenoxy-4'-phenyl mercaptodiphenyl sulfide 2-phenoxy-2'-phenyl mercaptodiphenyl sulfide o-bis (phenylmercapto) -benzene p-bis (paenylmercapto) -benzol Phenylmercapto (phenoxy) biphenyl bis (o-phenyl mercaptophenyl) sulfide Bis (p-phenylfflercaptophenyl) sulfide Bis (m ~ phenyireercaptophenyl) sulfide 1,2,3-3? Ris (pjbenylniercapto) -benzene

1,2,4-Tris (plienylniercapto) benziol 1,3,5-2? Ris (phenylmercapto) benzene o-bis (o-piienylraor oaptopiienjlmercapt ο) -b enzol p-bis (p-piienylffi © rGaptoplienylmercapt6) -benzene p-bis (o-piienyliiiercaptopiieiiylraercapto) -beazole p-bis (m-pb.enylioaercapijopb.eriylrii er-capto) -benzene m-bis (p-plienylmercapoopb.enyliaercapto) -benzene o-bis (p-phenylffier capt ophenylmer saptfo) -b enzol

ar-bis (plienylraercapto) -ar '- (phenylmercapto) -benzene

2,2'-bis (piieayloier capt ο) -diphenyl ether 2,3'-bis (phenyliBercapto) -diphenyl ether 2,4 · '-Bis (phenylmercapt ο) -diphenyl ether 4,4 * -BisCia-tolyliaercapt ο) -diphenylether

., 3 * -Bis (ώ-tolylmercapto) -diphenyl ether 2,4 '~ Bie (m «* tolylinercapto) -diphenyl ether

., 4 ⁱ -Bis (m ~ tolylmercapto) -diphenyl ether

909835/1543 -8-

3 j 3'-bis (p-tolylmercaptο) -diphenylether 3,3'-bis (xylylmercapto) -diphenylether 4,4'-bis (xylylmercaptο) -diphenylether 3 ₁ 4. ' -Bis (xylylmercapto) -diphenylether 3,4'-bis (m-isopropylphenylmercapto) -diphenylether 3,3'-Ms (m-iBopropylphenylmercapto) -diphenylether 2,4'-bis (m-isopropylphenylmercapto) -dipheriylether 3,4 ' -Bis (pt ert.butylphenylmercaptο) -diphenylether

"4,4'-bis (pt.butylphenylmercaptο) diphenyl ether
3 »3'-bis (p-tert-butylphenyl mercapto) diphenyl ether
3,3'-bis (m-di-tert-butylphenylmercapto) -diphenylether 3,3'-bis (m-chlorophenylmercapto) -diphenylether
4,4'-bis (m-chlorophenyl mercapto) diphenyl ether
3,3 * -bis (m-trifluoromethylphenylmercapto) -diphenylether 4,4'-bis (m-trifluoromethylphenylmercapto) -diphenylether 3,4'-bis (m-trifluoromethylphenylmercapto) -diphenylabher 2,3'-bis (m-trifluoromethylphenylmercapto) -diphenyl ether

3 »3'-bis (p-trifluoromethylphenylmercapto) -diphenylether 3,3'-bis (o-trifluoromethylphenylmercapto) -diphenylether 3,3'-bis (m-methoxyphenylmercapto) -diphenylether 3,4 * -bis (m-isopropoxyphenylmercapto) -diphenyl ether 3,4'-bis (m-perfluorobutylphenylmercapto) -diphenylether 2-m-tolyloxy-2'-phenylmercaptodiphenyl sulfide 2-p-tolyloxy-3'-phenylmercaptodiphenyl sulfide 2-OxO? olyloxy-4 ^f -m-phenylsulfaptodip Tolyloxy-3'-phenyl mercaptodiphenyl sulfide 3-m-tolyloxy-4'-phenyl mercaptodiphenyl sulfide

909835/1543 -9_

- '-phenylmercaptodiphenylsulphide J-xylyloxy-4'-phenylmercaptodiphenylsulphide 3-xylyloxy-3'-phenylmercaptodiphenylsulphide 3-phenoxy-3'-m-tolylmercaptodiphenylsulphide 3-phenoxy-4'-m-tolyl-mercaptodiphenylsulphide 3-phenoxy-4'-m-tolyl-mercaptide 3-phenoxy-4'-m-tolyl-mercaptide 3-phenoxy-4'-m-tolyl-mercaptide 3-phenoxy-4 -'- m-isopropylphenylmercaptodiphenylsulfide 3-phenoxy-3'-m-isopropylphenylmercaptodiphenylsulfide 3-m-toloxy-3'-m-isopropylphenylmercaptodiphenylsulfide 4-m-'l ¹ rif luormethylphenoxy-4'-idiphenylsulfod 3-phenylsulfod m-trifluoromethylphenoxy-4'-phenylmercaptodiphenylsulfide 2-m-trifluoromethylphenoxy-4'-phenylmercaptodiphenylsulfide 3-m-trifluoromethylphenoxy-5'-phenylmercaptodiphenylsulfide 3-p-chlorophenoxy-3'-phenyl-4-bromophenoxy-3'-phenyl-4-bromophenoxy - and pihenylmercaptodiphenylsulfid.

Mixtures of polyphenylthioethers can also be used in the process of the invention. A typical example of Gemische'von Polyphenylthioäthern contains in G "w # ^ of about -5% to about 55 # m-Phenoxyphenr / l-ia'-phenylmercaptophenylsulfid, from about 255 to about 3595 ^ bis (m-phenylmercaptophenyl). - sul £ id and from about 18 # to about 25 ^ bis (m-phenoxyphenyl) sulphide.

Preferred polyphenyl thioethers of this invention are mixtures of m-BieCphanylraercapto) -benzene and determine

S09835 / 1SA3

BATH ORIGINAL

-ιο-

other materials that have the property to use them for to make the purposes discussed above suitable and especially for such applications as lubricants for nozzle assemblies, which require thermal and oxidative stability at high temperatures and a wide range of fluids.

Such other materials may advantageously be used in amounts of from about 20 to about 200 parts by weight per hundred Parts of m-bis (phenylmercapto) benzene are used. Among the other materials that are for use with m-ßis (phenylmercapto) -benzene intended to form such mixtures include:

(a) the three-, four-, five- and six-hing polyphenylthioethers, for example o-bis (phenylmercapto) benzene

V.

Bis (m-phenylmercaptophenyl) -su3.fid VI,

m-HieiiylmercaptopheDyl-p-piienyliBercaptophenylsulfid,

90-9 8 357 154

BATH ORIGINAL

-11-

VII.

the trisphenyl mercaptobenzenes, VIII.

such as 1, 2, 4-trisphenyl mercaptobenzene. 3,5'-bis (pheny! Mercapto) -biphenyl

IX.

ATI

m-bis (p ~ phenylmercaptophenylmercapto) -benzene _i

m-bis (m-phenylmercaptoplienylinercapto) -benzene

909835/1 543 -12-

and bis ^ -Cm-phenylmercaptophenylmercapto) -phenyl7-sulfide

Cb) You mixed polyphenyloxy thioethers of the formula

wherein R is phenyl, R _{1 is} phenylene, and Y and Y _{1 are} each oxygen and / or sulfur, provided that at least one of Y and Y _{1 is} sulfur and c is an integer from 1 to 5. Examples of such suitable polyphenyloxythioethers are α-phenyl mercaptodipheayl ethers

909835/1543

BATH

XIV.

3,3'-bis (phenoxy) diphenyl sulfide,

XV.

Q.

3-phenoxy-3-phenyl mercaptodiphenyl sulfide,

XVI.

3-Piienylmercapto-2i'-pheno3cydiph.enylether,

XVXI.

-l-bis (ph $ nylinercapto) »- diphenylätlier

xviii.

m-Biö (m-phenylBi8X'captopienoxy) -benzene, 909435/1543

BATH ORIGINAL

XIX.

and 3-phenylmercapto- ^ '- (m-phenylinercaptopheiiylinercapto) diphenyl ether,

XX.

(c) the four-, five- and six-ring polyphenyl ethers of formula

XXI.

where m «2, 3 or 4- | is, such as bis (m ~ phenoxyphenyl) ether,

phenoxy) -benzene, m-

-phenoxyphenoxy ^? - jB-phenoxyphenoxyJ ^ -benzene, p-bis (m-phenoxyphenoxy) 4benaol, m-bis (p-phenosyphenoxy) -;

benzene and orBis (m-pheno

henoxy) -benzene and combination

The connections vönl (&) to (c). The ones given above Compounds (a) and (b) WonnenÄehso alone or together

909835/1

S43

with each other and with (c) in the invention Procedures are used.

Certain limited formulations are given due to the various possible mixtures described above the wider liquid range and, in many cases, unexpectedly low evaporation losses, as well as others Properties which make such preparations suitable as lubricants for jet machines are preferred. the more restricted, preferred preparations are given in Table 1 below.

Table I.

CD O CD OO U)

No. Always be in a hurry Gew. ^ B area 1 m-bia (Phenylmercaptο) -benzene
a mixture of approx. 65 $ m-bie (m-phenoxyphenoxy) -benzene
50 $ mL (m-phenoxyphenoxy) (p-phenoxyphenoxy)] benzene
5 # m-bis (p-phenoxyphenoxy) benzene 80-70
20-50 IV) m-bis (Phenylmercapt ο) -benzene
m-bis (phenoxy) -diphenyl sulfide 55-45
45-55 5 m-bis (Phenylmercaptο) -benzene
5-phenoxy-5'-phenyl mercaptodiphenyl sulfide 65-35
55-65 4th m-bis (Phenylmercapt ο) -benzene
m-bis (phenylmercaptophenyl) sulfide
m-bis (phenoxy) -diphenyl sulfide 66-45
18- 6
40-27 5 m-bis (Phenylmercaptο) -benzene
m-bie (phenyl mercaptophenyl) sulfide
5-phenoxy-5 ^f -phenyl mercapt or phenyl sulfide 65-45
20- 6
45-25 6th m-bia (Phenylmercaptο) -benzene
m-bia (Phenylmercaptophenyl) -sulfid
m-bis (phenylmercaptophenyl) -ether 70-42
25-5
45-15 7th m-bis (phenylmercapto) benzene
m-bis (phenylmercaptophenyl) sulfide
m-Phenylmercaptophenyl-p-phenFlmercaptophenylsulfide 57-45
25-5
48-25 8th m-bis (Phenylmercaptο) -benzene
m-Phenylmercaptod iphenylather
o-bis (Phenylmercaptο) -benzene 54-45
52-19
51-22 9 m-bia (Phenylmercapt ο) -benzene
m-bis (phenyl mercaptophenyl) sulfide
3-phenoxy-5 * -phenyl mercapt or phenyl sulfide
m-bie (phenoxy) -diphenyl sulfide 55-45
20-10
50-10
50-10

As used herein, the term "metal" includes metals in their elemental form. Most Group Ia metals are commercially available in many forms, such as flakes, chips, crystals, Plates and granules, any of these shapes can be used in the method according to the invention. the preferred metals are sodium and potassium.

When carrying out the process according to the invention for the preparation of the improved polyphenylthioethers, the contacting can be carried out of the liquid, as would be the case for those skilled in the art of bringing liquids into contact with solids or gases known to be effected, for example by stirring a mixture of the liquid and the metal or Gas, by passing the liquid through a packed column of the metal or by bubbling the Oxygen-containing gas through the liquid. Under the term contact as it appears in the description and in the Claims used, therefore, is to be understood as the use of force acting on either the liquid that Metal or the oxygen-containing gas acts. Examples for such application of force are stirring the liquid 'speed and bubbling through the oxygen-containing gas through the liquids. After treatment, the liquid can be used for separating liquids from solids known means can be obtained, such as by filtering or distilling the liquid from the

909835/1543 -18-

action vessel. under reduced pressure.

In general, the improvements in the liquid properties obtained by the process according to the invention remain unaffected by the concentration of the metal, the contact time or temperature, but these should be carried out in such a way that minimal concentration, time and temperature values are used, since among these the process according to the invention cannot be carried out will. A minimum metal concentration of about 0.01 wt.% Of Polyphenylthioäthers should be used. On the other hand, the advantages obtained are influenced by the particle size. The degree of benefit obtained appears to increase as the particle size of the metal decreases. The contact time can vary depending on the particle size, but a minimum of about one hour at about 25 ° C should be used. In general, times from 1 to 48 hours are sufficient under most conditions.

The temperature at which the inventive method is carried out may range from about 25 0 to 35O ⁰ C or higher. The selection of a particular temperature is dictated by, for example, the time available, the facilities available, the particle size and amount of metal, and the properties of the liquid being treated. For example, if the metal is in

9Q9835 / 1543

Amounts is used by 0.5 to 1 wt.% Of the liquid, at a contact time of about 1 to 5 hours at temperatures in the range of about 100 ⁰ C to about 300 ⁰ C, an optimum efficiency in both the device and the purity the liquid achieved.

The mechanism by which the improvements in properties the ether treated according to the method according to the invention takes place, is not yet complete enlightened. However, such improvements are completely unexpected in view of the lack of cleaning effectiveness in the case of such metals and gases as are known or ascribed to them through an adsorption mechanism is. The improvements of the above-described, according to the process according to the invention, are particularly unexpected produced liquids in terms of color and smell.

Of the metals of Group Ia of the Periodic Table of the Elements, potassium is used in the process according to the invention mostly preferred because it is low cost and is generally available in many forms. It has been found that potassium powder in particular is best suited for the process of the invention, although if the process is carried out at temperatures above the melting point of the metal, the starting form is of no concern is.

909835/1543

BATH ORIGINAL

1Θ03596

The following, non-limiting examples illustrate the method according to the invention.

example 1

A flask equipped with a thermometer, distillation column and stirrer to agitate the contents was charged with 150.0 g of m-bis (phenylmercapto) benzene and 0.15 g of potassium metal. The mixture was heated under ötickstoff to approximately 200 ⁰ O and held for two hours .for this temperature for about with stirring. The metal was separated from the liquid by filtering it through a coarse glass filter. The liquid treated in this way had very little odor compared to the untreated liquid and was much lighter in color.

Example 2

In a suitable flask as described in Example 1, 150 g of 5.5 ^l -bis (phenylmercapto) -diphenyl ether are brought into contact with potassium metal in the manner described in Example 1, except that the temperature 25 ⁰ O and the contact time 24 hours. A liquid with improved odor, improved color and greater oxidative stability was obtained.

Separate samples of m-BiB (phenylaiercapto) ~ benzene, below designated as liquid Δ, were obtained by contacting with other metals of this invention in the manner

909835/1543 ₂₁

Treated by Example 1. Similarly, it was continued a! liquid, hereinafter referred to as liquid B, which is based on the weight of approximately 5O # m-ßis (phenylmercapto) benzene, 11 # m-bis (phenoxy) diphenyl sulfide, 15 $ m-bis (phenyl mercaptophenyl) sulfide and 24 $ 3-phenoxyphenyl-3'-phenylmercaptodiphenyl sulfide consists, treated by contacting the separated samples with potassium. The results of the treatments are summarized in Table II below. In each lalle were results similar to those given in Example 1 were obtained in terms of odor.

The values shown in Table II were obtained using evaluation methods to evaluate the oxidative stability of a lubricant. The procedure is described in the 'Federal Test Specification 791' Method 5308, except that the liquid is heated to a temperature of 50O ⁰ F (260 ⁰ O) for a period of 48 hours instead of 250 ⁰ F (121 ⁰ O) for 168 hours heated in the presence of certain metals and oxygen. The increase in viscosity of the lubricant was determined. Furthermore, information regarding the corrosiveness of a lubricant towards metals can also be obtained. In order to demonstrate the effectiveness of the method according to the invention for improving the oxidative stability and for reducing the corrosiveness of the liquids, samples of the as in the above 909835/1543 -22-

Example treated liquid and untreated samples of the same liquid tested, The metal test specimens used were steel, copper, silver, titanium, magnesium alloy and aluminum alloy. However, only the results for copper and silver are given because the untreated tested preparations have essentially no effect to steel, magnesium alloy, titanium and aluminum alloy. The viscosity measurements were determined according to ASTM method D-44-5-53T using a Gannon-Penske modified Ostwald viscometer. The percentage of viscosity increase was determined by measuring the viscosity of the samples before and after the test, the difference being divided by the initial viscosity and multiplied by the quotient 100. The corrosiveness to metals was determined by weighing the metal samples of known size before and after the test.

909835/1543

-25-

Example Mr. Liquid metal Table II Metal conc.

- * Viscous ate increasing attack T.Metall

at 100 ^W F v 37.8 ° C; mg / car

Ig

Cu

CO O CO OO CO

3 4 5 6 7 8 9

A B A

B A

A A

control

control

potassium

potassium

lithium

sodium

potassium

0.05 *

0.05 *

0.1 *

0.1 *

0.1 *

7.79 3.14 1.45 2.40 4.22 2.08 1.99

• 5.65 -3.27 -1.67 -1.50 -2.25 -2.02 -1.76

- 2.31

- 0.89

- 0.13

- 0.24

- 1.29

- 0.23

- 0.24 &

^x weight * liquid CO CJI CO

cn

According to the figures in Table II above, the decrease in the increase in viscosity shows the increased oxidation stability the polyphenyl thioether, provided that such thioethers have been brought into contact with alkali metals. In addition, the corrosiveness to copper and silver has been significantly reduced.

Example 10

In a suitable flask, distillation column, heating and gas introducing means was equipped with a thermometer, 1000 g, m-bis (phenylmercapto) benzene introduced, which were then heated to a temperature of about 200 ⁰ C. A small amount of low boiling material was removed at approximately 185 ° G. Air was, for a period of 16 hours at a speed of 175 ft in the liquid through a tube which extended to the bottom of the flask ⁵ / Ste (4.96 m ⁵ / STDE) bubbled in, keeping the temperature at approximately 200 ⁰ G was held. The liquid was then distilled from the flask at a temperature range from 187 ⁰ O to 195 ° 0 and the oxidative stability of the liquid was determined by the method described above. It was found that the liquid has a viscosity increase at 100 ⁰ G of 3.6 #, while another sample of the test liquid, treated as above, except that no air was flushed through, a viscosity increase at 100 ⁰ O of 8.5 # exhibited.

909 8-3 5/1543 -25-

«25 -

Similar results were obtained using the procedure of Example 8 but at temperatures from 25 ° 0 to 30O ⁰ O or higher. The contact time can be used from 1 to 24 hours and the gas flow rate adjusted according to the device used and the desired contact time. Therefore, the gas flow rate can range from 50 to 500 ft ^ / PRS © (1.4 * .to 14.2 m ^ / STDE), but usually in the range of 150 to 200 ft ⁵ / STDE (4.25 to 5, 66 m ⁵ / STDE) are during a time period of 2 to 8 hours at a temperature of about 150 to 25O ⁰ G.

The contact time can be enriched by using an oxygen in the air. In addition, any inert carrier gag mixed with oxygen can be used will. Gases such as carbon dioxide, nitrogen, or helium that contain oxygen in the range of 5 # to 50 # vol. contain, can be used.

Although this, noise finding in terms of various specific examples and embodiments are described it is clear that this does not limit it and that they are in various ways within the realm of subsequent claims can be carried out.

909835/1. 543

-26-

Claims (11)

Patent claims: 1. A process for the preparation of improved polyphenylthioethers, characterized in that a polyphenylthioather is mixed in the liquid phase with a contact agent, namely alkali metals and / or an oxygen-containing gas
brings in contact. 2. The method according to claim 1, characterized in that the contact agent is an alkali metal. 3. The method according to claim 1, characterized in that the contact agent is an oxygen-containing gas. 4-, The method according to claim 1, characterized in that the bringing into contact at a temperature in the range of
about 1CXi ⁰ C to about 350 ⁰ C is carried out. 5. The method according to claim 2, characterized in that Lnj is carried out to about 35O ⁰ C. contacting at a temperature of about 100 ⁰ C. 6. The method according to claim.1, characterized in that the polyphenylthioether has the formula -27-909835 / 1543 A h -H (A ₁ ) * wherein each of the radicals A, Δ-, A ~ ^un ^ · ^ 3 ^β ^ ^{η is} chalcogen having an atomic number of 8 to 16, provided that at least one of the radicals A, A ^ ₁ A ^ and A, has an atomic number of 16 , the radicals X, X ^, X ₂ , X * and X ^ are hydrogen, alkyl, haloalkyl, halogen, arylalkyl and / or substituted arylalkyl, L, in and η are integers with a value from 0 to 8 and a is a is an integer having a value from 0 to 1 provided that when a = O, m is an integer having a value from 1 to 2. 7. The method according to claim 4, characterized in that the polyphenylthioether has the formula where m is an integer from 0 to 6, A and A ¹ independently) Are oxygen and / or sulfur, provided that little- ' at least one of the beds A and A ^{1 is} sulfur. 909835/154 3 -28- BATH R - Y - (R ₁ - V ₀ - R where R is a phenyl group, R ^ © ine phenylene group and Y and Y ^ are oxygen and / or sulfur, provided that at least one of Y and Y ^ is sulfur and c is an integer from 1 to 5 ie * u * ¹ « ³ · (2) Mixtures of ( ⁷ I) is. 12. The method according to claim 5, characterized in that the oxygen-containing gas is air. 909835/1543 8. The method according to claim 4, characterized in that the polyphenyl ether has the formula wherein A and A ^{1 are} oxygen and / or sulfur. Process according to Claim H, characterized in that the polyphenylthioether is m-J3is (phenylmercapto) benzene. 10. The method according to claim 5, characterized in that the polyphenylthioether is a mixture of about 20 to 200 parts by weight of (1) a compound of the formula ) H - Y - (H ₁ - V ₀ - R where H is a phenyl group, H * is a phenylene group and Y and Y ^ are oxygen and / or sulfur and c is a whole Number is from 2 to 5; and (2) mixtures of (1) per 100 parts is m-bis (phenylmercapto) benzene. 11. The method according to claim 5, characterized in that the polyphenylthioether (1) is a compound of the formula 909835/1543 -29-