DE1191961B - Process for the production of elastomeric molded articles - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C08f

German class: 39 b -22/06

Number:
File number:
Registration date:
Display day:

1191 961
F28597IVc / 39b
June 3, 1959
April 29, 1965

A method for producing crosslinked elastomers has already been proposed, according to which copolymers of ethylene and vinyl compounds containing at least one tertiary carbon atom, in particular vinyl esters, in a manner known per se in the presence of radical-forming Substances, preferably organic peroxides, exposed to elevated temperatures. According to this procedure products with good elastic rubber-like properties are obtained, which are also characterized by a high resistance to atmospheric influences, such as the effects of oxygen and ozone, distinguish. However, a reduction in the mechanical properties of these elastomers occurs when the Vulcanized ethylene copolymers exposed to high temperatures for a long time will.

It was also proposed the mechanical properties of copolymers made of ethylene and vinyl compounds by adding preferably at least three polymerizable carbon-carbon double bonds containing compounds, e.g. B. triallyl cyanurate, in the presence of to improve radical-forming substances during crosslinking. Here, too, are the mechanical properties the elastomers are insufficient if the vulcanized ethylene copolymers are used for a longer period of time Exposed to high temperatures.

It has now been found that the good mechanical 3 " Properties of the process products described even after exposure to higher temperatures are retained when in the production of elastomeric moldings with crosslinking of copolymers from ethylene and a vinyl compound containing at least one tertiary carbon atom at elevated temperatures in the presence of radical-forming substances, organic compounds with at least two polymerizable carbon-carbon double bonds anti-aging agents and optionally fillers that crosslink using such unsaturated polymerizable Compounds that have three allyl groups, and in the presence of as anti-aging agents for olefinically unsaturated synthetic or natural rubbers known per se secondary, aromatic Amines, heterocyclic compounds and / or phenols is carried out.

This finding is surprising insofar as it could not be foreseen that the aging inhibitors mentioned, which are known per se as free radical scavengers, have no adverse effect on the crosslinking process for the production of elastomers
Moldings

Applicant:

Paint factories Bayer Aktiengesellschaft,

Leverkusen

Named as inventor:

Dr. Herbert Bartl, Cologne-Stammheim;

Dr. Julius Peter, Vienna

the copolymers would have with the help of radical formers.

Examples of suitable anti-aging agents are: alkylated and aralkylated diphenylamines, 4-alkoxy- and 4,4'-dialkoxydiphenylamine, phenyl-oc- and - / S-naphthylamine, aldol-a- and - / S-naphthylamine, N, N'-di- / 3-naphthyl-p-phenylene-dia min, Ν, Ν'-diphenyl- and N-phenyl-N'-cyclohexyl-pphenylenediamine. 2-mercapto-benzimidazole, polymeric 2,2,4-trimethyldihydroquinoline and 6-phenyl-2,2,4-trimethyldihydroquinoline, 5,5'-diacridine, 4-oxydiphenyl, 4,4'-dioxydiphenyl, phenols aralkylated with styrene, alkylated and aralkylieite dioxybenzenes, alkylphenol sulfides, Reaction products of alkylene phenols and aliphatic aldehydes, e.g. B. 2,2'-methylenebis (4-methyl-6-tert-butylphenol) Mannich bases from alkylated phenols, formaldehyde and aliphatic or heterocyclic amines.

The aging inhibitors mentioned are preferably used in amounts of 0.05 to 5, in particular 0.1 to 1 percent by weight, based on the copolymers used.

Polymerizable compounds containing three alkyl groups which are suitable for carrying out the process described are, for example, triallyl cyanurate and triallyl phosphate. These compounds are preferably used in amounts of 0.5 to 20%, but preferably 1 to 10 ° / _0, based on the weight of the copolymers. The individual conditions to be observed in this connection correspond to the procedure described in French patent specification 1,225,704.

For example, the copolymer of ethylene and one containing at least one tertiary carbon Vinyl compound with peroxides of a compound having three allyl groups and the

509 567/351

Mixed anti-aging agents and vulcanized for 5 to 30 minutes at temperatures of 150 to 180 ° C.

In the following examples the parts given are parts by weight.

example 1

The following mixtures are produced on a rolling mill with full cooling:

Copolymer of 45 parts of vinyl acetate and 55 parts of ethylene

Pyrogenically derived silica

Dicumyl peroxide

Triallyl cyanurate

4,4'-thio-bis- (6-tert-butyl-3-methylphenol)

Parts A I B

100

15th

100

15th

The mixtures are vulcanized in the vulcanization press for 30 minutes at 151 ° C. (= 4.0 atmospheric steam pressure) and the test specimens obtained are exposed to hot air at 150 ° C. for 0, 7, 14, 21 and 28 days. The physical values of the vulcanizates before and after the various stages of aging are as follows. (Tensile strength [kg / cm ⁸ ], elongation [%]> hardness [Shore]).

0 days 50 ° C hot air

7 days of 50 ° C hot air

14 days of 50 ° C hot air

21 days 50 ° C hot air

Vulcanizate from mixture A I B

154/520/55 completely hardened completely hardened completely hardened

177/475/54 155/275/60

54/120/63

20/70/68

Example 2

The following mixtures are produced in an internal mixer with full cooling:

Copolymer of 45 parts of vinyl propionate and 55 parts of ethylene Pyrogenically derived silica ...

Triallyl phosphate

Di-tert-butyl peroxide

Bis (3-cyclohexyl-5-methyl-2-oxyphenyl) methane

Parts C 1 D

100 15

2.5 2.5

100 15

2.5 2.5

1.0

The mixtures are vulcanized in the vulcanization press for 30 minutes at 151 ° C. (= 4.0 atmospheric steam pressure) and the test specimens obtained are exposed to hot air at 150 ° C. for 0, 7, 14, 21 and 28 days. The physical values of the vulcanizates before and after the various aging stages are as follows (tensile strength [kg / cm ² ], elongation [· /,], hardness [Shore]).

OTage 150 ° C hot air

7 days 150 ° C hot air

14 days of 50 ° C hot air

21 days 150 ° C hot air

Vulcanizate from mixture C I D

104/320/55 completely hardened completely hardened completely hardened

114/360/55

127/290/60

60/190/62

50 / 70/67

Example 3

The following mixtures are produced on a rolling mill with full cooling.

Copolymer of 30 parts of vinyl acetate and 70 parts of ethylene

Active carbon black

Dicumyl peroxide

Triallyl cyanurate

Phenyl-oc-naphthylamine

Parts

100

30th

The mixtures are vulcanized in the vulcanization press for 5 minutes at 180 ° C. in an electrically heated press and the test specimens obtained are exposed to the action of hot air at 150 ° C. for 0, 7, 14, 21 and 28 days. The physical values of the vulcanizates before and after vulcanization are as follows (tensile strength [kg / cm ² ], elongation, hardness [Shore]).

25th

Days 150 ° C. Hot air Vulcanizate from mixture F. Days 150 ° C. Hot air E. 170/475/84 0 Days 150 ° C. Hot air 160/350/85 182/380/86 7th Days 150 ° C. Hot air 104/220/87 120/270/84 14th Days 150 ° C. Hot air hardened 80/210/87 21 hardened 90/110/87 28 hardened

Example 4

The following mixtures are produced on a rolling mill with full cooling:

40 mixed polymer of 45 parts of vinyl acetate and 55 parts of ethylene ..

Pyrogenically derived silica ...

Dicumyl peroxide

Triallyl phosphate

N-Cyclohexyl-N'-phenyl-phenylenediamine

Parts G H

100 15 2 2.5

100

The mixtures are vulcanized in the vulcanization press for 20 minutes at 15 ° C. (= 4.0 atmospheric steam pressure) and the test specimens obtained are exposed to the action of hot air at 150 ° C. The physical values of the vulcanizates before and after the various aging stages were as follows (tensile strength [kg / cm ² ], elongation [° / ₀ ], hardness [Shore]).

öo - Days 150 ° C. Hot air Vulcanizate from mixture H Days 150 ° C. Hot air G 130/420/50 0 Days 150 ° C. Hot air 154/520/55 140/370/50 65 7 Days 150 ° C. Hot air hardened 130/310/54 14th Days 150 ° C. Hot air hardened 103/290/55 21 hardened 87/250/56 28 hardened

Example 5

Mixtures of the same structure as in Example 4 using a Copolymer made from 40 parts of propylene and parts of ethylene and the mixtures Vulcanized minutes at 150 ° C in the press. Here, too, the mixture with the addition of amine shows a considerably better heat aging.

Claims (1)

Claim: Process for the production of elastomeric moldings with crosslinking of copolymers from ethylene and a vinyl compound containing at least one tertiary carbon atom at elevated temperatures, in the presence of radical-forming substances, organic Compounds with at least two polymerizing 10 baren carbon-carbon double bonds, anti-aging agents and optionally fillers, characterized in that the crosslinking using such unsaturated polymerizable compounds which have three allyl groups and in the presence of secondary, aromatic rubbers known per se as anti-aging agents for olefinically unsaturated synthetic or natural rubbers Amines, heterocyclic compounds and / or phenols is carried out. Considered publications:
Belgian patent specification No. 569 958. Legacy Patents Considered:
German Patent No. 1 125 648. 509 567/351 4.65 © Bundesdruckerei Berlin