DD291088A5 - USE OF CYCLIC MULTIPOSE PHENOLES AS AGING PROTECTION IN RUBBER ARTICLES - Google Patents

Abstract

The invention relates to the use of calixarenepolyols as anti-aging agents in rubber-based rubber materials, the plastic sealants (raw rubber) produced therefrom and rubber articles (vulcanizates) with high heat aging, weather, ozone and media resistance, such as profiles, hoses, cable sheathing, sleeves, buffers , Rubber-metal elements, Belaegen, plates, gaskets, tires o. The like. And as a primary stabilizer in synthetic rubbers. Calixarenpolyole as anti-aging agent or as Primaer stabilizer have high antioxidant activity with long-term effects even in the presence of liquid media, provide protection against fatigue, ozone attack and rubber poisons and prevent the "crazing" effect {calixarenpolyols; Anti-aging agents; Rubber materials; Rubber; Rubber products; Sealants; Hoses; Tire; Primaerstabilisator; Antioxidant; Waermealterungsbestaendigkeit; antiozonant; Wetterbestaendigkeit; "Crazing" effect}

Description

2. Use of cyclic Mehrkernphenole according to claim 1, characterized in that in the mixing process of the rubber mixture Calixarenpolyole in a dosage of 0.05 to 10 parts by mass, preferably 0.5 to 4.0 parts by mass, based on 100 parts by mass of elastomer be added.

3. Use of cyclic Mehrkernphenole according to claim 1, characterized in that a calix [4] arenpolyol in combination with a non-discoloring and / or discoloring anti-aging agent, preferably with a mercaptobenzimidazole and / or substituted p-phenylenediamine, is added.

4. Use of cyclic Mehrkernphenole according to claim 1, characterized in that in the emulsion, Lösunge- or suspension polymerization for the preparation of synthetic rubbers in the form of homopolymers or copolymers Calixarenpolyole as primary stabilizer in a dosage of 0.05 to 5 mass Teilo, preferably 0 , 5 to 3 parts by mass, based on 100 parts by mass of rubber.

Field of application of the invention The invention relates to the use of calix [4] arene polyols and their derivatives as anti-aging agents

- in light-colored and soot-filled technical rubber articles such. B.

In profiles, hoses, cable sheaths subject to the process of salt bath, water bath, steam or hot air vulcanization at relatively high temperatures,

• in profiles, hoses, cable sheathing, sleeves, buffers, rubber-metal elements, linings, sheets, seals and tires, which are required to withstand high weather, ozone and / or heat aging,

• in profiles, hoses, linings, plates, gaskets, sleeves, buffers, rubber-metal elements, which are exposed to the influence of hot water, coolants, hydraulic fluids or fuels and lubricants,

- In nichtkorttaktverfärbenden light-colored and soot-filled rubber articles such. B.

• in profiles, buffers, sleeves, hoses, plates, linings, gaskets which are subject to the conditions already mentioned during manufacture or use,

- In little discolored light colored rubber articles such. B.

• in profiles, hoses, tires, plates, linings, sleeves, buffers, seals,

in plastic sealants,

- in synthetic rubbers (as a primary stabilizer).

Rubber materials based on elastomers of natural and / or synthetic rubber are used for these rubber articles, the following synthetic rubbers - also in the form of blends - representing the field of application of calix [4] arene polyols as anti-aging agents:

- Isoprene rubber IR

- Styrene-ButadlervKautechuk SBR

- butadiene rubber BR

- Acrylonitrile butadiene rubber NBR

- Chloroprene-Kautechuk CR

- Ethylene-propylene-Dlen-rubber EPDM

- chlorinated ethylene rubber CM

Acrylonitrile Butadiene Rubber Polyvinyl Chloride Compound

Hydrogenated acrylonitrile-butadiene rubber HNBR

- Epichlorohydrin rubber ECO

Butyl rubber HR

Chlorosulfonated polyethylene CSM

- Block polymers based on butadiene / styrene

Characteristic of the known state of the art

As protective agents with long-term action in rubber vulcanizates are according to H.Fries (rubber, asbestos, plastics 40 [1987] p.238-258) aminic substances, in particular substituted p-phenylenediamines and substituted naphthylamines in the first place. These substances, however, in the practical use of the rubber articles in question under the influence of light and / or heat cause a discoloration of the rubber or of other materials in contact with it, from brown to black. Further disadvantages of the aminic anti-aging agents are:

Leachability of substituted naphthylamines and especially the most active members of the class, the substituted p-phenylenediamino,

relatively high thermal volatility, especially for Ν, Ν'-dialkyl and N, N'-aralkyl derivatives of p-phenylenediamines and also substituted naphthylamines,

more or less pronounced influence on the scorching time of crude rubber mixtures,

- cancerogone effect of ß-naphthylamine as an impurity of the anti-aging agent phenyl-ß-naphthylamine. Therefore, in those cases where the discoloration or contact discoloration of the gum products plays the dominant role, there is a switch to non-or little discoloring phenolic antioxidants, to mono- and bifunctional phenols. However, according to L Ruetz (The Bisphenol Anti-Aging Agents, 1985, No. 2.15, p. 1-12), the antioxidant activity of the monofunctional phenolic compounds is high due to their volatility in the vulcanization process of the rubber blanks and / or at high use temperatures of the rubber articles decreasing concentration.

Further disadvantages of the monofunctional phenols as anti-aging agents are

easy extraction by water, alcohols, hydrocarbons and other solvents,

no protection against ozone and fatigue cracking,

- Low protection against heat and oxygen as well as heavy metal poisons compared to bisphenols. Disadvantages of the bifunctional phenols as anti-aging agents in rubber products are

no protection against ozone cracking under static and / or dynamic mechanical conditions,

- in the light slight discoloration to yellow, pink or brownish,

Extractability by alcohols, hydrocarbons and other solvents,

- higher production costs.

To eliminate the non-existent ozone protection of phenolic antioxidants in rubber materials, there is an additional use of non-discoloring antiozonants based on enol ethers, acetals, thioureas or nickel salts of substituted dithiocarbamates. However, the disadvantages of these non-staining antiozonants are

- no good heat and fatigue protection,

no long-term effect due to excessive volatility and extractability,

- no broad application spectrum, i. Limitation to rubber materials with a special elastomer basis,

- efflorescence effects at higher dosage.

To avoid the hardening and embrittlement of synthetic rubbers according to W. Breuers and H. Luttropp (Buna-production, testing and properties, VEB Verlag Technik Berlin 1954, p.73-89) substituted aromatic amines, such as. Phenyl-ß-naphthylamine or N, N'-dinaphthyl-p-phenylenediamine, added as a primary stabilizer in the polymerization process. These are substances with a high antioxidant effect, but discolored on exposure to light and / or heat

 Primary stabilizers based on

- substituted phenols such as. As 2,6-di-tert-butyl-4-methyl-phenol, tert-butylnaphthol,

phenolic derivatives of diphenyls, e.g. p-oxydiphenyl, 4,4'-dioxydiphenyl, p-dioxydiphenyl sulfide,

- Phenolic derivatives of diphenylmethane such. B. ρ, ρ'-Dioxydiphenyldimethy! Methane,

- alkylated aryl phosphites

Although little to no discoloring, but significantly weaker in terms of their anti-aging effect.

Object of the invention

The object of the invention is to eliminate the described disadvantages of the known anti-aging agents in rubber products, in plastic sealants and synthetic rubbers.

Explanation of the essence of the invention The object of the invention is to find antioxidants for rubber articles which have at least the same advantages as

known products, but at the same time have a significantly lower volatility, are effective against ozone cracking, in

Alcohols, hydrocarbons and other solvents are difficult or insoluble and produced inexpensively

can be. In plastic sealants and synthetic rubbers, the antioxidants are said to prevent premature hardening and embrittlement.

The object is achieved in that cyclic as antioxidants in rubber-based rubber products Condensation products of polyhydric phenols are added with carbonyl compounds. It is particularly advantageous Calix (4) arenpolyole the structure I use that are economically feasible on an industrial scale. These substances can in a conventional manner by acid-catalyzed condensation of polyhydric phenols with Aldehydes (J. Am. Chem. Soc., 62, 2512 (1940)).

R ³

HO

With

R ¹ = H ₁ alkyl, aryl

R ² = H alkyl

R ³ = H ₍ OH.alkyl, aryl, aminoalkyl

Calix [4] arene polyols are cyclic condensation products of low volatility and decomposability, which are difficult or insoluble in almost all solvents.

Although some calix [4] arene polyols are known per se, however, since there are no or few studies on their properties, it was surprising to find the said new use. It has been recognized that calix [4] arene polyols have the following advantages over the known bisphenolic antidegradants:

- greater protection against heat and oxygen,

Antiozonanswirksamkeit in the presence of microcrystalline waxes, which is particularly in difficult to protect nitrile rubber materials to bear and the reinforced by substituted p-phenylenediamines protective effect even more,

- no thermal volatility,

no extractability by water, alcohols and hydrocarbons,

low solubility in the known solvents,

- long-term protection against heat, oxygen and metal poisoning,

- Fatigue protection in the presence of 2-mercaptobenzimidazole, 4- or 5-methyl-2-mercaptobenzimidazole and / or their zinc salts.

While the known anti-aging agent 2,2'-methylene-bis / 4-methyl-6-tert-butyl-phenol / (Vulkanox BKF) at Room temperature to 1 to 5g in 100ml gasoline soluble, in toluene, acetone and alcohols even more than 5g in 100ml Solvent, i. are readily soluble, are from tetramethylcalix [4] arenoctol at room temperature in all mentioned Solvents less than 0.1 g dissolved in 100ml. The cyclic anti-aging agents according to the invention prolong the life and useful life of rubber products,

they allow the use of rubber articles for special purposes and increase the utility value of the rubber.

The following examples are intended to illustrate the effectiveness of the calix [4] arene polyols and to explain their applicability,

without restricting it.

embodiments example 1 Silica-filled NR / SBR material of Shore hardness A60 ± 5 without and with Calix [4] arene polyol

not according to the invention 2 invention 4 mixtures Ma. parts mixtures Ma. parts 1 51.00 3 51.00 components Ma.-Telle 49,00 Ma. parts 49,00 natural rubber 51.00 * 9,20 51.00 9.20 ölverstreckterButadien-styrene rubber 49,00 11,80 49,00 11,80 high molecular weight butadiene-styrene plasticizer 9.20 29,60 9.20 29,60 zinc oxide 11,80 28,90 11,80 28,90 kaolin 29,60 37.50 29,60 37.50 precipitated silica 28,90 4.90. 28,90 4.90 Zinc sulfide / barium sulfate filler 37.50 2.30 37.50 2.30 Fact is 4.90 5.30 4.90 5.30 stearic acid 2.30 4.90 2.30 4.90 rosin 5.30 0.00 5.30 0.00 Ozone protection wax 4.90 2.00 4.90 0.00 2,6-di-tert-butyl-4-methylphenol 2.00 0.00 0.00 0.00 2,2'-methylene-bis- [4-methyl-6-t-butyl-phenol] 0.00 0.00 0.00 2.00 Tetramethyl CaLiX [4larenoctol 0.00 0.20 2.00 0.20 Tetramethyl-calix [4] arendodecaol 0.00 0.72 0.00 0.72 diphenylguanidine 0.20 0.85 0.20 0.85 tetramethylthiuram 0.72 2.60 0.72 2.60 mercaptobenzothiazole 0.85 0.85 sulfur 2.60 2.60

240.77

Vulcanization of the elastomer raw mixtures: 10 minutes at 15O ⁰ C Characteristics of the vulcanizates

240.77

240.77

A: heat aging behavior Percentage loss of tensile strength Δσ _Β / σ _Β · 100% and elongation at break Δε _Β / ε _Β 100% after heat aging of 7 Days at 70 ° C or 7 days at Tt) O ⁰ C determined according to TGL14366 or 14367 to ring bodies of 6mm thickness property

Material of mixture 1 2

21 -15 -12 -12 35 -28 -22 -20 44 -37 -35 -34 63 -59 -54 -53

_Δσ Β / _σ Β x 100 after 7d / 70 ° C _Δε Β / _ε Β · 100nach7d / 70 "C _Δσ Β / _σ Β x 100 after 7d / 100 ° C _B Ae / e _B -100nach7d / 100 ^° C

B: Ozone aging behavior Initial strain (crack-free strain range) Di in%, number of cracks A and crack depth T in the strain zone Z2 in the range of 11 to

20% elongation after ozone aging at an ozone concentration of 50 pphm, a temperature of 4O ⁰ C and a

Test duration of 72 hours, determined according to TGL 24418 at 0 to 50% continuously expanded hollow cylindrical specimens of 3 mm

thickness

Explanation of terms: Initial strain D, in% is the static strain at which the first crack occurs. A D, value of 30% means that between

and 29% lying strain area remains crack-free. Crack number A and crack depth T are classified as follows:

AO A1 A2 A3 A4

no cracks ibis 5 cracks 6 to 40 cracks 41 to 120 cracks over 120 cracks

property TO no cracks T1 surface cracks approx. 0.1 to 0.55 mm deep T2 cracks about 1 mm deep T3 cracks over 1 mm deep T4 openwork specimens

Material of mixture 1 2

Initial elongation Di in% Number of cracks A Crack depth T

10 14 19 20 4 3-4 2 2 1 1 1 1

C: weathering behavior Initial elongation Di in%, number of cracks A and depth of crack T in the expansion zone Z5 after a weathering period of 29 days under

following Central European meteorological standard conditions:

mean ozone concentration 29 mg / m ³

mean air temperature 8,5 ⁰ C

average daily sunshine duration 4,7h

 average daily rainfall 1,6mm

determined according to TGL16890 on the sun and shadow side at 0 to 50% continuously stretched hollow cylindrical specimens of 3 mm thickness.

Material of mixture

property 1 2 3 4 Sunny side of the specimen Initial strain Di in% 30 40 45 46 Number of cracks A 3 2 2 2 Crack depth T 2-3 2 2 2 Shadow side of the specimens Initial strain D ₁ in% 28 33 41 42 Number of cracks A 3 2-3 2 2 Crack depth T 2 2 2 2

D: Deterioration behavior

Mean cracking resistance RBW as the decadic logarithm of the kilocycles until reaching the mean cracking level C after a compression deflection test according to De Mattia (TGL 14378) determined on strip specimens of 6.3 mm thickness.

Material of mixture Property 1 2 3 4

RBW 0.58 0.89 0.93 0.95

E: contact coloration Lacquer discoloration of white alkyd resin paint to factory standard GKTS 802-3 / 01 on specimens of dimensions

100mm -20mm -2mm

Material of mixture Property 12 3 4

Discoloration after 21 days Outdoor exposure none none none none

(under following meteorological

Conditions:

average air temperature = 9.8 ⁰ C

average daily sunshine duration = 3.1 hrs

average daily rainfall = 7.9mm)

F: "crazing" effect after a sunshine duration of 470 hours:

Material of mixture 12 3 4

Intensity of the "crazing" effect not present not available not available

available

Example 2 Carbon black NBR material of Shore hardness A65 ± 6 without and with Calix | 4] arenepolyol

not according Erflndungsgemäße 6 invention 8th mixtures Ma. parts mixtures Ma. parts 5 100.00 7 100.00 components Ma. parts 0.93 Ma. parts 0.93 Butadiene-acrylonitrile rubber 100.00 1.43 100.00 1.43 phthalic anhydride 0.93 0.00 0.93 0.00 N-lsoprdpyl-N'-phenyl-p-phenylenediamine 1.43 1.43 1.43 0.00 Phenyl-beta-naphthylamine 1.43 0.00 Tetramethylcalix [4] arenoctol 0.00 0.00 0.00 0.00 Ν, Ν-dimethylaminomethylene 0.00 1.43 tetramethylcalix [4] arenoctol 0.00 6.43 1.43 6.43 Piperidinomethylen-tetramethylcalix [4] arenoctol 0.00 2.50 0.00 2.50 zinc oxide 6.43 15.71 ' 6.43 15.71 stearic acid 2.50 62.86 2.50 62.86 chalk 15.71 6.43 15.71 6.43 soot 62.86 6.43 62.86 6.43 microcrystalline ozone protection wax 6.43 12.50 6.43 12.50 triphenyl 6.43 2.38 6.43 2.38 Phthfisäuredibutylester 12.50 1.07 12.50 1.07 sulfur 2.38 2.38 N-cyclohexyl-sulfenamide ^ -benzothiazyl 1:07 1.07

220.10

220.10

220.10

220,! Ο

Vulcanization in a steam-heated press: 40 minutes at 15O ⁰ C The characteristic values of the vulcanizates were determined by the TGL indicated in Example 1 and on specimens described there

determined. An exception is the determination of the heat aging method. Itens, the 2mm thick bar specimens

took place.

property

Material of mixture 5 6

A: heat aging behavior Relative change of Elongation at break Δε _Β / ε _Β % after 3d / 100 ° C -35 Relative change of Elongation at break Δε _Β / ε _Β % after one

3 days of storage in the gasifier fuel 88bei 20 ⁰ C and a subsequent

Heat aging of 3d / 100 ° C -40

-28

-34

-34

-14

-30

-13

B: Weathering behavior 21 44 28 27 Initial strain D |% 2 1-2 1-2 2-3 Number of cracks A (strain zone Z5) 3 2 3 3 RißtiefeT (DehnungszoneZ5) on the specimen sun side after one Ventilation of 100 days be! following Central European meteorological Standard conditions: mittl.Ozonkonz. 29pgm ~ ³ mittl.Lufttemp.8,5 ° C mittl.tägl. Sunshine duration 4.7 hours mittl.tägl. Rainfall 1.6mm C: fatigue behavior 1.78 1.78 1.93 2.15 Medium cracking resistance RBW D: Ozone aging behavior 21 34 27 23 Initial strain D |% 2 0 1 2 Number of cracks A (strain zone Z3) 1 0 1 1 Cracking depth T (strain zone Z3) after an ozone aging at 50pphm / 40 ° C / 72 h 20 33 26 21 Initial strain D |% 2 0 1-2 2 Number of cracks A (strain zone Z3) 1 0 1 1 Crack depth T (strain zone Z3)

after an aging of the ozone at 100 pphm / 50 ° C / 96h

property

Material of mixture 5 β

Number of cracks A 3 3 2-3

Cracked teas 3-4.3 3-4

after a 3t8g! gen storage in the

Carburetor fuel 88 at 20 "C and a

subsequent heat aging of 3d

at 100 ⁰ C determined on 2 mm strip-shaped

Test specimens according to TGL 24418

(Test conditions:

Ozone concentration: lOOpphm Test chamber temperature = 5O ⁰ C Test duration = 48 h

sta .. strain = 20%)

Example 3 Silica-filled NR / SBR material with different anti-theft agents for the detection of

synergistic effect

3 2-3

components

not inventive invention

Mixture mixtures

10 11

2-mercaptobenzimidazole

Tetramethyl-calix [4] areroctol

2,6-di-tert-butyl-4-meth / l-phenol

2,2'-methylenebis [4-methyl-6-t-butyl-phenol] tetramethyl-calix [4] arenedodecaol

2.00 0.00 0.00 0.00 0.00

0.00 1.00 2.00 1.00 0.00 0.00 0.00 0.00 0.00 0.00

Other components as in the mixtures 1 to 4 of Example 1

Vulcanization of the elastomer blends: 10 minutes at 1 ¹ V ⁰ C. The characteristic values of the vulcanizates were determined by the TGL indicated in Example 1 and on specimens described there

determined.

'iigenschaft

Material of mixture 10

A: heat aging behavior Relative change of the elongation at break _Δε Β / _ε Β x 100% after 7 d at 70 ⁰ C x 100% nach7dbei100 ° C

B: Fatigue behavior

Mittle rer crack resistance RBW RBW after heat aging of 7 d / 70 ° C

-26 -57

0.95 0.64

-22

-54

1.16 0.70

Example 4

Soot-filled EPDM material of Shore hardness A: 70 ± 5 without and with Calix [4] arene polyol

-17 -43

1.43 1.07

not inventive • invention proper mixture contemporary mixture components 12 13 EPDM rubber 100.00 100.00 Ma.-T. stearic acid 1.10 1,10Ma.-T. zinc oxide 3.65 3,65Ma.-T. soot 116.40 116.40 Ma.-T. paraffin oil 36.40 36.4OMa ₁ -T. paraffin wax 3.65 3.65 Ma.-T. polym. 2,2,4-trimethyl, 2-dihydroquinoline 0.57 0.00 Ma.-T. Tetramethylcalix [4] arenoctol 0.00 0.57 Ma.-T. sulfur 0.34 0.34 Ma.-T. tetramethylthiuram 1.45 1.45 Ma.-T. Zinkdiäthyldithiocarbamat 2.09 2.09 Ma.-T. 4,4'-dithiomorpholine 1.45 1.45 Ma.-T. 267.10 267.1 OMa ₁ -T.

Vulcanization in a steam-heated press: 50 minutes at 150 ⁰ C property

Material from> 12 lischung

13

A: Thermal aging behavior according to TGL14367

Relative change in the elongation at break ε _Β

after 7 days exposure to an ethylene glycol / water mixture (37:63) at 90 ° C. (determined on 2 mm thick rod specimens)

- after a heat aging of 7d at 100 ^° C in hot air determined 6mm thick ring specimens)

-14% -27%

-10% -24%

Example S

Soot-filled CR / SBR material of Shore hardness A: 55 ± 5 without and with Calix | 4] arene polyol

components

not according to the invention

mixture

14

erfindungsgemäßa

mixtures

15

chloroprene rubber 67,00 Materials on mixture 15 67,00 67.00Ma.-T. 16 Butadiene-styrene rubber 33,00 14 33,00 33,00Ma.-T. zinc oxide 4.50 4.50 4,50Ma.-T. Stearinsäuro 1.95 1.95 1,95Ma.-T. magnesia 3.00 3.00 3,00Ma.-T. chalk 11.90 11.90 11,90Ma.-T. soot 53.70 53.70 53.70 Ma.-T. Fact is 43.30 43.30 43.30 Ma.-T. petroleum softeners 23,90 23,90 23.90 Ma.-T. calcium oxide 4.50 4.50 4.50 Ma.-T. microcrystalline protective wax 4.50 4.50 4.50 Ma.-T. Tetramethylcalix ^ larenoctol 0.00 1.95 0,00Ma.-T. 2,2'-methylene-bis [4-methyl-6-tert-butyl-phenoll 1.95 0.00 0.00 Ma.-T. Tetramethylcalix | 4] arendodecaol 0.00 0.00 1,95 Ma.-T. sulfur 1.84 1.84 1.84 Ma.-T. tetramethylthiuram 0.73 0.73 0,73 Ma.-T. Zinkphenyläthyldithiocarbamat 1.06 1.06 1.06 Ma.-T. dibenzothiazyldisulfide 0.28 0.28 0.28 Ma.-T. 2-thioxo-4-thiozolidinon 0.36 0.36 0.36 Ma.-T. 257.67 257.67 257.67 Ma.-T. Vulcanization in a steam-heated press: 15 minutes at 150 ° C property

A: Heat aging behavior according to TGL14367, determined on 2 mm thick specimens

Relative change in the elongation at break ε _Β

- after heat aging of 7d at 7O ⁰ C in hot air -37% -30% -28%

- after heat aging of 7d at 100 ° C -50% -45% -44%

B: Ozone aging behavior

according to TGL 24418, determined on 0 to 50% elongated hollow cylindrical specimens under the test conditions:

Ozone concentration: lOOpphm test room temperature: 50 "C

Test duration: 96h.

Initial strain D | 15% 19% 19%

Number of cracks A (in zone Z2) 2 1 1

Cracking depth T (in expansion zone ~! 2) 2 1 1

C: Weathering behavior in accordance with TGL16890 determined on 40% of dumbbell specimens after 12 days of growth cleavage on the sunny side of the specimen under standard European meteorological conditions:

av. Ozone concentration:

av. Air temperature:

av. daily sunshine duration:

av. daily rainfall:

Number of cracks A

Crack depth T

29pg / m ³ 1 1-2 8,5 ⁰ C 1 1 4,7Stdn. 1,6mm 3-4 1

Claims (1)

claims: 1. Use of cyclic Mehrkernphenole as an anti-aging agent in rubber-based rubber articles, the plastic sealants (raw rubber) and rubber products (Vulkanlsate) such as profiles, hoses, cable sheathing, sleeves, buffers, rubber-metal elements, coverings, plates, gaskets, tires o. like. and are used as primary stabilizer in synthetic rubbers, characterized in that one or more calix [4] arene polyols of general structure I are used as anti-aging agents. HO With R ¹ -H, alkyl. aryl R ² = H, alkyl R ³ = H. OH. alkyl, aryl,
aminoalkyl