DE962022C - Anti-aging agent for rubber - Google Patents

Description

The invention relates to improvements in the manufacture of age-resistant natural ones and synthetic rubber compounds and articles made therefrom.

It has been found that 2-allylphenols, which in the 4-position have an alkoxy substituent which has not more than 12 carbon atoms, very much represent valuable anti-aging agents for natural and synthetic rubber compounds.

In particular, it has been found that such rubber mixtures have excellent, non-discoloring and fracture and bending-resistant properties. Such masses are particularly valuable for the white sidewalls of car tires. The allyl alkoxyphenols can be prepared according to the procedures described for the methoxy and ethoxy derivatives in Journal für Praktisches Chemie, 1921, 102, 44 and Journal of the American Chemical Society, 1944, 66, 1077. The isopropoxy, n-butoxy, γεε-Ύή- methylhexoxy and n-dodecoxy derivatives can be mentioned as preferred compounds which can be used according to the invention.

These anti-aging agents are used in the manufacture of rubber articles according to the usual

Union method used, preferably in amounts of about ¹ J ₁ to 2 percent by weight of the rubber.

According to the invention, synthetic rubber is used for example, polymers of i, 3-butadiene and 2-chlorobutadiene-i, 3 and copolymers of these Compounds with acrylic acid, styrene, methyl methacrylate understood.

In the following examples, in which parts mean parts by weight, the invention is explained in more detail without however, to be limited to that.

example 1

The following mixes were prepared using standard mixing procedures, once 2-Allyl-4-methoxyphenol was used as an anti-aging agent and in the other case none was used.

Mixture A B

Light crepe ΐοο, ο ΐοο, ο

Zinc oxide 10.0 10.0

Barium sulfate 75.0 75.0

Stearic acid 1.0 1.0

Sulfur 3.0 3.0

Diphenylguanidine 0.5 0.5

2-Allyl-4-methoxyphenol 1.0, -

Panels were made from each mixture and cured at 141 ^° C. for 75 minutes. Aging tests were carried out with the vulcanizates.

The results of the aging tests were as follows:

Mixture A

tensile strenght Elongation at break (kg / cm ² ) i * Vo Unaged 144 637 in the oxygen bomb at 70 ⁰ and 21 kg / cm ² , 8 days aged long 38 496

Mixture B. The sample spoiled in the aging test carried out in the oxygen bomb after 2 days.

Example 2

The following mixtures were prepared in the usual way, once with and in the other case without 2-allyl-4-methoxyphenol.

mixture

AWAY

Smoked sheets 100.0 ΐοο, ο

Zinc oxide 5, ° 5, °

Carbon black 47.5 47.5

Stearic acid 3.0 3 °

Sulfur 3.0 3.0

Mercaptobenzothiazole 0.85 9.85

2-Allyl-4-methoxyphenol 1.0 -

Panels of each mixture were vulcanized for 45 minutes at 141 ° and the flexural strength test subject. the number of

Bends that lead to a common level of brittleness were as follows:

Mixture A B

Bends io ~ ³

Pinholes 63 9.0

small fractions 150 18.0

average fractions 265 27.0

deep fractions 340 31.5

Example 3.

In order to show the non-discoloring properties of the anti-aging agents, the following were used Mixtures prepared in the usual way, once with and the other time without 2-allyl-4-methoxyphenol.

mixture

AWAY

Light crepe 100.0 100.0

Zinc oxide 10.0 10.0

Barium sulfate 75.0 75.0

Stearic acid 1.0 1.0

Titanium dioxide 10.0 10.0

Sulfur 2.0 2.0

Zinc diethyl dithiocarbamate ....... 0.375 0.375

2-AUyl-4-methoxyphenol 1.0 -

A plate of each mixture was vulcanized for 12 minutes at 125 ^0th Samples of the vulcanized material were exposed to ultraviolet light and the following results were obtained:

Mixture A B

Appearance after 8 hours

Exposure as with the cream

Blind colors

attempt appearance after 16 hours

Exposure also deep cream-colored

Example 4

The following mixtures were prepared using 2-AHyl-4-ethoxyphenol, of 2-allyl-4-dodecoxyphenol and without anti-aging agents.

Light crepe 100.0

Zinc oxide 5.0

Titanium dioxide 50.0

activated calcium carbonate. 35.0

Aluminum silicate 25.0

Stearic acid 0.25

Vaseline «1.0

Sulfur 2.5

Mercaptobenzothiazole 0.75

2-allyl-4-ethoxyphenol 1.0

2-AHyl-4-dodecoxyphenol ..

Mixture B

100.0 100.0 5.0 5.0 50.0 50.0 35, o 35, o 25.0 25.0 0.25 0.25 1.0 1.0 2.5 2.5 o, 75 o, 75

- 1.0 -

Plates of each mixture of 30 minutes, cured at 141 ⁰ long.

Bending tests were carried out with test pieces in the manner described in Example 2 and achieved the following results:

Mixture ABC

Bends io ~ ³

Pinholes ... 13.5 12.0 6

small fractions .. 22.5 22.5 12

medium fractions 46.0 40.5 17

deep breaks .. 54.0 49.5 21

Example 5

The following mixtures were prepared using 2-AHyl-4-methoxyphenol, of 2-allyl-4-ethoxyphenol, of 2-allyl-4-dodecoxyphenol and without anti-aging agents.

Mixture ABCD

Light crepe ΐοο, ο ΐοο, ο ΐοο, ο ΐοο, ο

Zinc oxide 10.0 ΐο, ο ΐο, ο ΐο, ο

Barium sulfate 75 »° 75> ο 75» ° 75 »°

Stearic acid ΐ, ο ΐ, ο ΐ, ο ΐ, ο

Sulfur 3.0 3.0 3.0 3.0

Diphenylguanidine 0.5 0.5 0.5 0.5

2-AUyl-4-methoxyphenol. 1.0 - - -

2-Allyl-4-ethoxyphenol ... - 1.0 - -

2-AlIyI ^ dOdCCOXyPhBnOl. - - ΐ, ο -

Sheets of each mixture were vulcanized for 75 minutes at 141 °, and with the vulcanizates aging tests were carried out.

The results of the aging tests were as follows:

Tensile strength (kg / cm ² )

Mixture ABCD:

Unaged 164 179 164 177

in the oxygen bomb
at 70 ⁰ and 21 kg / cm ²

Aged for 8 days 58 69 68 spoiled 12 - - - 32 40 39 -

16 - - - 35 42 46

Example 6

The mixture and vulcanization treatment were the same as in Example 1.

It became 2-AHyl-4-n-butoxyphenol with 2-allyl-4-methoxyphenol compared, the properties of which have already been explained.

Anti-aging agents

2-allyl-4-methoxyphenol ..
2-Allyl-4-n-butoxyphenol ..,

Mixture A B

Tensile strength (kg / cm ²

Mixture * A B

Unaged

in the oxygen bomb

70 ° and 21 kg / cm ²
"Aged for 8 days
12 16 -

at

165

60

31

21

161

66 38 32

Example 9

The mixture and vulcanization treatment were the same as in Example 2.

. Anti-aging agents. ° τ>

2-Allyl-4-methoxyphenol ... 1 -

2-Allyl-4-n-butoxyphenol ... - 1

Fracture stages bends io ~ ³

Pinholes 40.5 58

small fractions 90.0 144

middle. Fractions 234.0 297

deep fractions: 300.0 390

Claims (1)

Claim: Use of a 2-allyl phenol, which has an alkoxy substituent with not more than 12 carbon atoms in the 4-position, as an anti-aging agent for natural or synthetic rubber, preferably in amounts of ¹ ^ to 2 percent by weight of the rubber. © «B 659/496 10.56 (609 863 4.57)