DE2629997A1 - PHENOLIC COMPOUNDS - Google Patents

Description

MÜLLER-BORE · GROENING · DEUFEL · SCHÖN · HERTEL

DR.WOLFQANQ m0LLER-BOR £ (PATENT ADVOCATE FROM 1927-1070) HANS W. QROENINQ ₁ DIPL-INO, DR.PAUL DEUFELDIPL-CHEM. DR. ALFRED SCHUN, DIPL.-CHEM. WERNER HERTEL, DIPL-PHY3.

S / G 17-226

The Goodyear Tire & Rubber Company, Akron, Ohio, USA

Phenolic compounds

The invention relates to the use of sulfur-containing Phenolic compounds as antioxidants for polymers, both saturated and unsaturated as well as vulcanized and unvulcanized. It also relates to a method for producing such compounds.

There is a constant search for new and effective antioxidants to stabilize polymers against oxidative degradation. In all areas it is desirable that an antioxidant has a reduced tendency to discolour a polymer, either before or after exposure, of aging conditions, especially high temperature aging conditions, on the polymer. Resistance to oxidation and discoloration is essential on the

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SIEBERTS1K. i · 8000 MÜNCHEN 80 · POB 800720 · KABEI .: ΙΠΤΕΒΟΡΛΤ ■ TEL ·. (080) 4710 VO TELEX 5-22G3S

ORIGINAL INSPECTED

th of particular concern on which polypropylene is used. ■ '- ■■

Phenolic compounds have occasionally been used to impart antioxidant protection. There are already bisphenols for Used (see for example US-PS 3,459,7Q4, 3,679,744 and 3,637,809 as well as CA-PS 812,262).

The object of the invention is to provide phenolic antioxidants to protect polymers against oxidative degradation. The invention is intended to provide polymers that are stabilized against oxidative degradation. Furthermore, a method for the production of such antioxidants is intended to be provided.

The invention provides sulfur-containing phenolic compounds of the structural formula given below and used as an antioxidant used in diene rubber:

AXA ¹

where A and A are selected from the following structures I and IT:

CD

R7R ° CH ₂ -I -.C- (CH ₂ ) J _n Y ¹ COCHCH- ^(II)

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and X for

^; f '■■' '■

where Y ^{1 is} -O- or -NH- and R and R are selected from the group consisting of tertiary alkyl radicals with 4 to 8 carbon atoms and cycloalkyl radicals with 5 to 12 carbon atoms, while R, R, R, R, R and R are selected from the group consisting of hydrogen and alkyl radicals with 1 to 4 carbon atoms, R is selected from the group consisting of alkylene radicals with 2 to 6 carbon atoms, cycloalkylene radicals with 5 to 12 carbon atoms and alkylcycloalkylene radicals of the following formula:

-R ¹¹ - ^. '

consists in which R is an alkylene radical having 2 to 6 carbon atoms Y is selected from the group consisting of -O-, -S-, 1,4-phenylene as

-COR ¹³ OC- · ·

Il II

ο "ο '·'. '■■

and where η is 0 or 1, x + y + z 0 or an integer Number is from 2 to 12, R is a cycloalkylene radical with 5 to 12

11 12
Carbon atoms, R and R are alkylene radicals with 1 to 6 carbon

2 13

mean material atoms and η is 0 or 1, and also R is an alkylene radical with 2 to 6 carbon atoms, optionally with one or two groups of the structure

ti

- OCB

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may be substituted, in which B of the structural formula

R ⁸ ASR ⁷ -

14th
and wherein R is selected from the group consisting of alkyl radicals having 1 to 4 carbon atoms and phenyl, and m is 0 or 1, with the ^{proviso that when Y 1 is} -0-, m is 1.

1 2 3 4 5

Preferably R and R are tertiary butyl radicals, R, R, R, R and R is hydrogen or methyl, R is hydrogen, R and R is ethylene, η 0, χ Q to 3, y 0 or 1, ζ Q or 1, as well as x + y + z 0, 2 or

10 11 2

3. Preferably, R is cyclohexyl, R is ethylene and η is 0.

The following compounds are examples of compounds according to the invention Compounds without, however, restricting the invention to the compounds mentioned.

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number

Bis- (3,5-di-tert-buty1-4-hydroxyphenyl) -4,10-dithia-7-oxatridecanedioate

II bis (3,5-di-tert-buty1-4-hydroxyphenyl) -4,7,1Q-tri-thiatridecanedioate

III bis- [2,2-dimethyl-3- (3,5-di-tert-buty1-4-hydroxyphenyl) propyll-4,7,1O-trithia-2,12-dimethyltridecanedioate

IV bis-f2,2-dimethy1-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propyrj -4.1 0 ~ -dithia-7 ~ oxa-2,1 2-dimethyltridecanedioate

V N, N'-Bis-D, 1-dimethyl-2- (3,5-di-tert, -butyl-4-hydroxyphenyl) -äthyrj -4,1O-dithia-7-oxatridecandiamide

VI N, N'-Bis-n, 1_-dimethy 1-2- (3, 5-di-tert-buty 1-4-hydroxyphenyl) ethyl] -4,7-dithia-5-methyldecanediamide

VII bis (3,5-di-tert-buty1-4-hydroxyphenyl) -4,7-dithia-2,9-dimethyl decanedioate

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number

VIII

XIII

XVII

XVIII
XIX

Bis- (3,5-di-tert-butyl-4-hydroxyphenyl) -4,7-dithia-2, 5,9-trimethyl decanedioate

Bis- [4- (3,5-di-tert-butyl-4-hydroxyphenyl) -2-butyl -4,7,1Q-trithia-2,12-dimethyltridecanedioate

Bis- £ 4- (3,5-di-tert-butyl-4-hydroxyphenyl) -2-butyl -4,7-dithia-2,9-dimethyl decanedioate

Bis- [4- (3,5-di-tert-butyl-4-hydroxyphenyl) -2-butyl] 4,7-dithiadecanedioate

Bis-L2,2-dimethyl-3 (3,5-di-tert-butyl-4-hydroxyphenyl) propyl] -4,7-dithia-2,9-dimethyl decanedioate

Bis-C2,2-dimethyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propyl] -4,7-dithiadecanedioate

Bis-Γ2,2-bis (3,5-di-tert-butyl-4-hydroxybenzyl) propylj-4,7-dithiadecanedioate

Bis-f2,2-bis- (3,5-di-tert-butyl-4-hydroxybenzyl) butyl] -4,7-dithiadecanedioate

1,1,1-tris- [methylene-6- (3,5-di-tert-butyl-4-, hydroxyphenoxycarbonyl) -4 -thiahexanoate'-propane

1,1,1-Tris- [methylene-6- / 3- (3,5-di-tert-butyl-4-hydroxyphenyl) -2,2-dimethylpropoxycarbonyi] -4-thiahexano atj-propane

Tetrakis C-methylene-6- (3,5-di-tert-butyl-4-hydroxyphenoxycarbonyl) -4-thiahexanoate] methane

Tetrakis-Cmethylene-6- £ 3- (3,5-di-tert-butyl-4-hydroxyphenyl) -2,2-dimethylpropoxycarbonyi] -4-thiahexanoate-methane

All of the above compounds I to IX were prepared. Compounds I to IV are the compounds of Working Examples 1 to 4.

Further compounds, which as examples of the invention Connections are to be considered are the following:

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Ν, Ν ¹ -Bis- (3,5-di-tert-butyl-4-hydroxyphenyl) -4,9-dithiadodecanediamide

Bis-C3- (3,5-di-tert-buty 1-4-hydroxyphenyl) -propyl} 3,3 '- (1, S-cyclooctanedithio) -dipropionate bis- (3,5-di-tert. ^ buty 1-4-hydroxyphenyl) -3,3 '- [3,8-tricyclo- (5.2.1.0 ') -decandithiq] dipropionate

Bis-Γ2- (3, 5-di-tert-butyl-4-hydroxyphenyl) -ethylj -6,6 '(1,4-phenylene) -bis- (4-thiahexanoate)

Ν, Ν'-bis-ti-methyl-2- (3,5-di-tert-butyl-4-hydroxyphenyl) -ethylj-4,7-dithia-3 , 8-dimethyldecanediamide 1,6-hexanediyl-bis - [6- (3,5-di-tert »-buty1-4-hydroxyphenoxycarbonyl) -4-thiahexanoate]

Bis- [3,5-bis- (1,1-dimethylpropyl) -4-hydroxyphenyl] -4,7-dithiadecanedioate

Bis-C2,2-bis- (3,5-di-tert-butyl-4-hydroxybenzyl) -2-phenylethylj-4,7-dithiadecanedioate

Ν, Ν ¹ -BXS-C1 , 1-bis (3,5-di-tert-butyl-4-hydroxybenzyl) ethyl] -4,7-dithiadecanediamide

The compounds according to the invention can by the base-catalyzed Addition of a polymer cappan to a 3,5-di-tert-alkyl-4-hydroxypheir? IaUcylester or amide of an oC, ß-unsaturated carboxylic acid. The reaction is usually taking Use of an inert solvent carried out at a temperature between Z always tempera door and the boiling point of the solvent fluctuates. The manufacturing process is not critical to the use of these compounds as antioxidants .

The following examples explain the preparation of the compounds according to the invention Antioxidants using the method according to the invention. These examples are not intended to limit the invention.

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example 1

Bis- (3,5-di-tert-butyl-4-hydroxyphenyl) -4,10-dithia-7-oxate: ridecanedioate (R, R ¹ = tert-butyl; x, y, z- = 0; R ⁵ , R ⁶ , R ⁸ = H;
r7, r9 = C ₂ H ₄ ; Y = 0; n1 = 1

1 ml of triethylamine is added to a solution of 11 g of 3,5-di-tert-butyl-4-hydroxyphenyl acrylate and 2.74 g of 2-mercaptoethyl ether in 75 ml of ethanol. The temperature rises from 26 to 31 ^° C. over a period of a few minutes. The mixture is stirred for a few hours before being poured into water. The viscous oil which precipitates is separated off by extraction with benzene. The benzene is evaporated, leaving 13 g of a viscous yellow oil.

Example 2

If 3.1 g of 2-mercaptoethyl sulfide are used instead of the 2-mercaptoethyl ether according to Example 1, 14 g of bis (3,5-di-tert-butyl-4-hydroxyphenyl) -4,7,1O-trithiatridecanedioate are obtained
also in the form of a viscous oil. (R, R ¹ = tert-butyl; x, y, z = 0; R ⁵ , R ⁶ , R ⁸ = H; R ⁷ , R ⁹ = C ₃ H ₄ ; Y = S; n ¹ = 1)

Example 3

Bis-t2,2-dimethyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) -4,7,10- trithia-2,12-dimethyltridecanedioatej

To a solution of 18 g of 2,2-dimethyl-3- (3,5-di-tert-butyl-4-hydroxyphenyD-propyl methacrylate and 3.85 g of 2-mercaptoethyl sulfide in 75 ml of ethanol is a solution of 1 g of potassium hydroxide given in 10 ml of ethanol. The temperature rises from 24 to 32 ° C over a period of a few minutes. The reaction mixture is stirred for a period of 3 hours,

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before it is poured into water. The precipitated viscous oil is separated off by extraction with hexane. The extract is evaporated, leaving 17 g of a viscous oil which is slowly crystallized on standing.

Example 4

If 3.46 g of 2-mercaptoethyl ether are used instead of the 2-mercaptoethyl sulfide in Example 3, 19.5 g of bis-2,2-dimethyl-3- (3,5-di-tert-buty1-4-hydroxyphenyl) are obtained ) propyl] -4,10-difchia-7-oxa-2,12-dimethyl tridecanedioate. (R, R '= tert-butyl; χ = 2; y = O; 2 = 1; R ³ , R ⁴ , R ⁵ = CH ₃ ; R ⁶ , R ⁸ = H; R ⁷ , R ⁹ = C ₃ H ₄ ; Y = 0; η ¹ = 1)

Example 5

A mixture of 30 g of sodium hydroxide, 5 g of tetrabutylammonium bromide, 60 ml of water and 250 ml of benzene is heated to 70 ⁰ C. A solution of 127.5 g of 3,5-di-tert-butyl-4-hydroxybenzyl chloride and 17.5 g of propionaldehyde in 125 ml of benzene is added over a period of 5 hours. The Reaktonssmischung is stirred for a period of a further 30 minutes at 70 ⁰ C, and then by the addition of a solution of 50 ml of concentrated hydrochloric acid in 100 ml of water neutralized. The layers separate. The benzene is removed from the organic layer on a rotary evaporator. The viscous residue crystallizes when mixed with hexane. The solid is separated off by filtration. 67.5 g of 2,2-bis- (3,5-di-tert-butyl-4-hydroxybenzyl-propionaldehyde are obtained.

The product obtained in the reaction described above is dissolved in 300 ml of ethanol, whereupon 2.6 g of sodium borohydride added to the solution over a period of 10 minutes.

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The reaction mixture is for a period of 3 hours touched. Excess sodium borohydride is eliminated by the addition neutralized by 10 ml of a dilute (3: 1) hydrochloric acid. The mixture is filtered. The filtrate is poured into water. An amorphous mass precipitates out of which the water is decanted off. The sticky mass is dissolved in boiling hexane. 2,2-BiS- (S, 5-di-tert-buty1-4-hydroxybenzyl) propanol crystallizes on cooling the solution and is filtered off. The product weighs 53.4 g and melts at 162 to 164 ° C.

5.6 g of acryloyl chloride are added dropwise to a solution of 24.8 g of 2,2-bis (3,5-di-tert-butyl-4-hydroxybenzyl) propanol and 10 g of triethylamine in 1Q ml of tetrahydrofuran. During the addition, the temperature rises from 25 to 52 ^° C. The reaction mixture is stirred for a period of 4 1/2 hours and then poured into water. The mixture is stirred until the oil that has precipitated out has crystallized. The product is filtered off and allowed to dry. This gives 27 g - _r * 2 2-bis (3,5-di-tert-butyl-4-hydroxybenzyl) propyl acrylate melting at 175 ° to 179 ° C.

The product of the reaction described above is dissolved in 1QQ ml of ethanol together with 2.3 g of ethanedithiol and 1 ml of a 40% solution of benzyltrimethylammonium hydroxide in methanol. This mixture is heated to reflux for a period of 5 hours and then allowed to cool. The solid which precipitates during the heating period is filtered off. This gives 19.3 g of bis [2 _r 2-bis- (3,5-di-tert-butyl-4-hydroxybenzyl) propyl] -4,7'-dxthiadecandioat, melting at 156-161 ⁰ C. .

The polymers, which in an expedient manner by the inventive Connections that can be protected are vulcanized

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as well as non-vulcanized polymers that are susceptible to oxygen degradation, such as natural rubber, balata, gutta-percha and synthetic polymers, both saturated and unsaturated, ie those containing carbon-carbon double bonds. Representative examples of the synthetic see polymers that can be used to practice the invention are polychloroprene, homopolymers of a conjugated 1 _A 3 -biene, such as isoprene and butadiene, and copolymers of conjugated 1,3-bees, such as isoprene and butadiene, with up to 40% by weight of at least one copolymerizable monomer such as styrene and acrylonitrile, butyl rubber, which is a polymerization product of a major amount of a monoolefin and a minor amount of a multiolefin such as butadiene or isoprene. Poly ™ urethanes that contain carbon-carbon double bonds, as well as polymers and copolymers made from monoolefins that have little or no unsaturation, such as polyethylene, polypropylene, ethylene / propylene copolymers and terpolymers made from ethylene, propylene and a non-conjugated diene.

The exact amount of antioxidant to be used depends somewhat on the type of polymer as well as the severity of the harmful Conditions to which the polymer is exposed. In unsaturated Polymers, such as those made from conjugated dienes, is the amount of antioxidant required greater than the amount required by a saturated polymer such as polyethylene.

In general, the stabilizers according to the invention are used in antioxidant amounts of about 0.0005 to about 10 parts by weight per 100 parts by weight of the polymer, although these values vary with the respective polymer. A particularly preferred range is between about 0.025 and about 1 _f 5 parts. The compounds are particularly suitable

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for stabilizing polyethylene and polypropylene. The inventive Antioxidants have a high molecular weight, making them less volatile and less easy to remove Polymers are more extractable than antioxidants with lower levels of extract Molecular weight.

The antioxidants are independent of whether they are used alone or in the presence of other mixed ingredients, effective. Representative examples of such ingredients are metal oxides, reinforcing agents, pigments, fillers, plasticizers, other antioxidants, plasticizing agents, hardening agents or the like.

The antioxidants according to the invention can be added to the polymer can be added by any conventional method such as adding to the latex or solution form of the polymer or by adding directly to the polymer in solid form in one Mill or in a Banbury ». ·

Compounds I, II and IV to XIX were tested for Xn SBR in an amount of 1.0 part. Compounds IV to IX and XII were tested in polypropylene. The results are summarized below:

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262999

Compound days to failure at hours until 1% oxygen No. 140 ⁰ C in polypropylene ^{is absorbed at 100 0} C in SBR-1006

III

IV

VII

VIII

XII

XIII

XIV

XV

XVI

XVII

XVIII

XIX

494 (464) 523 Il 536 (464) 436 (328) 468 Il 593 Il 579 Il 653 Il 549 (282) 481 Il 701 (328) 434 (282) 362 (237) 371 (237) 375 (280) 371 Il 340 Il 438 Il

The values in brackets represent the oxygen absorption value for a butylated, octylated phenolic antioxidant as a reference substance.

All compounds tested improve the resistance of the polypropylene and SBR to degradation. In the absence of an antioxidant, the polypropylene fails in 1 to 2 days, while the SBR _{absorbs 1.0% O 2} in 5 to 10 hours.

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All phenolic antioxidants according to the invention can can be used to carry out the working examples described above and protect the polymers described.

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Claims (1)

Claims L 1./compound of the formula: AXA where A and A are selected from the following structures 1 and II: R ^e
ι (CH ₂ ) _x (CH) _Y (C) _z Y ^f COCHCK - '(D -C- . I t S COCHCH CU) and X for where Y ^{1 is} -O- or * -ΝΗ- and R and R ¹ are selected from the group consisting of tertiary alkyl radicals having 4 to 8 carbon atoms and cycloalkyl radicals having 5 to 12 carbon atoms 70981 1/1050 - 13 - consists, while R, R, R, R, R and R are selected from the group consisting of hydrogen and alkyl radicals with 1 to 4 carbon atoms, R _{1 is} selected from the group consisting of alkylene radicals with 2 to 6 carbon atoms, Cycloalcylene radicals with 5 to 12 carbon atoms and alkylcycloalkylene radicals of the following formula: η ' consists in which R is an alkylene radical having 2 to 6 carbon atoms Y is selected from the group consisting of -0-, -S-, 1,4-phenylene as 11 " O O and where η is 0 or 1, x + y + z 0 or an integer Number is from 2 to 12, R is a cycloalkylene radical with 5 to 12 11 12 Carbon atoms, R and R are alkylene radicals with 1 to 6 carbon 2 13 mean material atoms and η is 0 or 1, and also R is an alkylene radical with 2 to 6 carbon atoms, optionally with one or two groups of the structure Il - OCB may be substituted, in which B of the structural formula R ⁸ ASR ⁷ - 70981 1/1050 14th
and wherein R is selected from the group consisting of alkyl radicals having 1 to 4 carbon atoms and phenyl, and m is 0 or 1, with the ^{proviso that when Y 1 is} -0-, m is 1. 2. Compound according to claim 1, characterized in that it is incorporated into a polymer that is opposite to an oxidative Degradation is prone. 3. A compound according to claim 2, characterized in that A and A and A have a structure according to structure I. 4. A compound according to claim 3, characterized in that R and R are tertiary butyl radicals, R, R, R, R and R are hydrogen or methyl, R is hydrogen, R and R • I Are ethylene, η is 0, χ is 0 to 3, y is 0 or 1, ζ Means 0 or 1, and x + y + z is 0, 2 or 3. 5. A compound according to claim 4, characterized in that R 11 2 Is cyclohexyl, R is ethylene and η is 0. 6. A compound according to claim 2, characterized in that A and A have a structure according to structure II. 7. A compound according to claim 6, characterized in that R 1 5 8 and R are tertiary butyl radicals, R and R are hydrogen or methyl fi 7 9 1 mean, R is hydrogen, R and R are ethylene and η 0 709811/1050