DE1253453B - Process for stabilizing copolymers made from ethylene, an alpha-olefin and at least one polyunsaturated hydrocarbon - Google Patents

Description

GERMAN WW ^ SS PATENT OFFICE

German class: 39 b -22/06

EDITORIAL

Number: 1253 453

File number: C 37126IV c / 39 b

1 253 453 filing date: October 12, 1965

Open date: November 2, 1967

It is known to oppose synthetic and natural rubbers by adding certain compounds to stabilize unwanted changes. These undesirable changes in the rubbers occur through storage over long periods of time, thermal stress, oxygen or exposure to light on, whereby z. B. Changes in the processing behavior or in the color can occur.

In general, a combined protective effect is sought. The ones previously used for stabilization Compounds are either amines, such as. B. PhenyljÖ-naphthylamine, N-phenyl-N'-isopropyl-p-phenylenediamine, Aldol-a-naphthylamine, di- / 3-naphthyl-pphenylenediamine, or phenols, such as. B. 2,2-methylene - bis - (4 - methyl - 6 - tert - butylphenol). The compounds will either contribute to the rubber its manufacture, e.g. B. in the course of the work-up process, or afterwards at one of the added to further processing. In almost all cases, the stabilizers used work for the raw rubber also in the vulcanizate as an anti-aging agent. In this way, natural rubber, Butadiene-styrene rubber, polybutadiene rubber, butadiene-acrylonitrile rubber, polychloroprene rubber and unsaturated and saturated ethylene-α-olefin rubber, olefin oxide rubber and Stabilize butyl rubber.

The weakly unsaturated rubbers, such as unsaturated ethylene-propylene rubber, butyl rubber or the similarly structured polyolefin oxide rubber, in contrast to the more unsaturated rubbers in general and especially against the influence of heat only small amounts of stabilizers. Under special conditions, e.g. B. when using higher However, it is advisable to use mixed temperatures or particularly tough bearing loads Avoid damaging the rubbers and the vulcanizates made from them To use stabilizers in the amounts known from the more unsaturated rubbers.

Depending on the desired protective effect and the polymer structure, various Stresses in the course of polymer production, processing, long-term storage, production or processing of mixtures as mentioned above Stabilizers used in various amounts.

In any case, the highest possible stabilizing effect is desired, the ideal case being a non-discoloring one Stabilizer is the highest possible protective effect at low dosage.

The stabilization method applies to the stabilizers known to date

of copolymers made of ethylene,

an α-olefin and at least one multiple

unsaturated hydrocarbon

Applicant:

Chemical works Hüls Aktiengesellschaft,
Marl (district of Recklinghausen)

Named as inventor:

Dr. Harald Blümel, Marl (district of Recklinghausen)

As a rule, the particularly effective stain strongly, whereas the non-staining are comparatively weak

ao stabilize.

The stabilizing effect is generally determined by a short test.

It has now been found that copolymers of ethylene, an α-olefin and at least

»5 a polyunsaturated hydrocarbon against the effects of light and heat compared to the previous one known stabilization can stabilize more advantageously if 0.05 to 5.0 parts by weight, based on 100 parts of the rubber, of Ν, Ν-substituted diamines of the general formula

R ₁ -. / R4

J ^ NR ₃ -N ^
Ro Rc

^{2 5}

used, in which R ₁ and R _{2 represent} an alkyl, alkenyl or oxyalkyl _{radical, R 3} an alkylene radical and R ₄ and R _{5 represent} hydrogen, an alkyl or oxyalkyl radical and the alkyl, alkenyl and oxyalkyl radicals 1 to 16, preferably Have 1 to 5 carbon atoms.

Among the unvulcanized, unsaturated copolymers are those manufactured according to Ziegler elastomeric, vulcanizable copolymers of ethylene and another «-olefin with more than 2 carbon atoms as well as z. B. dicyclopentadiene, hexadiene (1,5), hexadiene (1,4), decatriene (1,4,9), Cyclooctadiene- (l, 5), 5-methylene-norbornene or other addition products of CycIopentadiene with Understood unsaturated compounds.

The diamines are added either in the course of polymer production or processing

709 680/447

or during the preparation or processing of the mixture.

As Ν, Ν-substituted diamines once N ₅ N-dialkyl or Ν, Ν-dialkenyl or Ν, Ν-dioxyalkyl-alkyleneamines, such as. B. N, N-diethyl-ethylenediamine, Ν, Ν-dimethylamino-propylamine, N, N-diethylamino-propylamine, N, N-dimethyl-trimethylenediamine, N, N-diethyl-trimethylenediamine, N, N-di-n- butyl-trimethylenediamine, N, N-bis-hydroxyethyl-trimethylenediamine, into consideration.

Also suitable are N, N-dialkyl, Ν, Ν-dialkenyl or N, N-dioxyalkyl-alkylene-N'-alkylamines, such as. B. N, N-diethyl-trimethylene-N'-propylamine, Ν, Ν-dimethylethylene-N'-ethylamine, N, N-dibutyl-trimethylene-N'-isopropylamine.

Finally, Ν, Ν-DialkyI-, Ν, Ν-Dialkenyl- or Ν, Ν-Dioxyalkyl-alkyIen-, N ', N'-Dialkyl-, Ν ', Ν'-dialkylene, Ν', Ν'-dioxyalkylamines, such as. B. N, N, N ', N'-tetra - (/ 3-hydroxypropyl) ethylenediamine, use.

The alkyl, alkylene or oxyalkyl radicals can also be any of the aforementioned types of compounds be exchanged for each other. For example, N-alkyl-N-alkylene, N-alkyl, N-oxalkylalkyleneamines or their substitution products are suitable.

The alkyl, alkylene and oxalkyl radicals have 1 to 16, preferably 1 to 5, carbon atoms.

The unsaturated ethylene-α-olefin rubbers stabilized in this way have increased resistance to thermal stress with or without simultaneous mechanical stress and oxygen access at the same time a lower tendency to discolour. This makes their shelf life in particular Dimensions increased.

The use of diamines in polyolefins of various structures for protection against electrostatic Charges is already from U.S. Patents 2,891,027, 2,891,029, and 2,959,567 known. The intended use of the diamines described in this context is, however thus completely different from that of the present proceedings. That is not the case with the known methods Was even remotely thought of a stabilizing effect, it already follows from the fact that the addition of the Diamines to polymers of completely different structure, such as. B. polyvinyl chloride or polyethylene, takes place, that is, of polymers that, according to the current state of the art, are made with the same stabilizers not let it stabilize at all.

To illustrate the problem underlying the invention, the table 1 shows the Description of the rubber types specified, the copolymers of ethylene and propylene homopolyethylene and also high-impact polystyrene according to Example 9 of the aforementioned US Pat. No. 2,891,027 juxtaposed. The order of the polymers results from increasing thermal stability.

While the polymers mentioned under V and VI are not then those within the scope of the invention The high-impact polystyrene mentioned under II speaks for the stabilization provided by the process practically just as little as the butadiene-styrene rubber mentioned under I on the claimed Stabilizers on.

The addition of diamines to the saturated copolymers or polyethylene turns out to be of from the outset as superfluous, as a crosslinking (viscosity) due to a temperature-time effect here

need not be suppressed. The proof of this is provided following the tables Diagram showing the curve progression given for mixed polymers or polyethylene in the time-viscosity diagram reproduces schematically.

The teachings given according to the state of the art can thus not be resolved without overcoming one Prejudice transferred to the unsaturated ethylene-propylene terpolymers to be stabilized according to the invention.

The process is explained in more detail using the following examples:

example 1

To determine the effect of various stabilizers, a newer type of Brabender plastograph with continuous recording of the torque by a writer is used. The kneading unit used in this way has a capacity of 75 cm ³ and is equipped with a stamp. The rotation speed of the two kneading arms provided with cams can be varied. The following test conditions are used:

Filling level of the kneader 0.8

Temperature in the kneader 190 ° C

Rpm 120

Filling time of the kneader 1 minute

An unsaturated ethylene-propylene rubber with a propylene content of about 40 percent by weight and dicyclopentadiene used as the tertiary component. The degree of unsaturation is about eight double bonds for every 1000 carbon atoms. Will this rubber under Treated the specified test conditions in the Brabender kneader, one obtains in addition to the first one Maximum at the beginning of the kneading work after about 20 minutes a second maximum of the Drea-, momentary display, which is caused by the crosslinking reactions that occur. The timing of the maximum represents a measure of the thermal stability of the rubber and is dependent on this on the unsaturation of the rubber, as well as by those listed in Table 1, extraordinarily short times for reaching the second maximum of the polydiene rubbers is proven. By adding known stabilizers or anti-aging agents, both phenolic and even of the aminic type, the time to reach the second maximum can be significantly increased.

Table 2 shows the effect of various stabilizers used in an amount of 0.25 and 1.0 parts by weight Rubber can be added to IOO parts. From this it can be seen that the effectiveness of depends on the amount of stabilizer used. The most favorable are the strongly discoloring p-phenylenediamine derivatives.

Finally, Table 3 shows the special protective effect of N, N-diethylethylenediamine, which only is achieved by N-phenyl-N'-isopropyl-p-phenylenediamine.

This protective effect is not only expressed at doses below 0.2 parts, but becomes especially interesting because the stabilizers according to the invention do not discolour are.

I 253 453

Example 2

Under the same test conditions as given in Example 1, N, N-dimethyl-trimethylenediamine shows As can be seen from Table 4, a similarly excellent protective effect as that in Example 1 used stabilizer.

Example 3

Under the same test conditions as indicated in Example 1, N, N-diethyl-aminopropylamine shows a similarly excellent protective effect as the stabilizer used in Example 1 (Table 5).

Table 1
(Comparison tests)

Type of rubber

Double bonds

on Carbon atoms

Type of stabilization

Time from the beginning the kneading treatment

until reaching of the second maximum of the torque display (viscosity)

Butadiene-styrene-cold rubber (22 percent by weight styrene 78 percent by weight butadiene)

High-impact polystyrene according to Example 9 or Claim 6 of US Pat. No. 2,891,027
85% polystyrene
5% polyacrylonitrile and 10% polybutadiene

Unsaturated ethylene-propylene rubber about 8 C = / 1000 carbon atoms (40 percent by weight propylene 52 percent by weight ethylene 8 percent by weight dicyclopentadiene)

Unsaturated ethylene-propylene rubber about 2 C = / 1000 carbon atoms (44 percent by weight propylene

54 weight percent ethylene

2 percent by weight dicyclopentadiene)

Saturated copolymers of ethylene + propylene (ML-4 ^ 50) (45 percent by weight propylene

55 percent by weight ethylene)

Polyethylene

about 200

about 20

1.25 weight
percent phenyl - /? - naphthylamine

Tetrahydroxyethylbutylenediamine

no stabilizer

no stabilizer

no stabilizer

no stabilizer

about 3 minutes

about 3 minutes

about 20 minutes

about 60 minutes

there is no maximum under the experimental conditions; H. no networking, on

there is no maximum under the experimental conditions; H. no networking, on

Table 2
(Comparison tests)

Time from the beginning the kneading treatment until the second maximum is reached Type of rubber Type of stabilization the torque display (viscosity) 1.0 part 0.25 parts stabilizer stabilizer la) Unsaturated Ethylene Mercaptobenzimidazole ³ ) 24 minutes about 20 minutes ⁴ ) Propylene rubber ¹ ) about 8 C = / 1000 coals material atoms b) the same Laurylamine ³ ) > 45 minutes 28 minutes

Footnote at the end of the table.

7 8

Table 2 (continued)

Time from the start of the kneader treatment until the second maximum is reached IN, α U IaCil UKdrL / \ n ucr oiauuisierung the torque display (viscosity) 1.0 part 0.25 parts Stabilizer stabilizer rA unsaturated / vuiyien- ^ ycionexyiainyiamin j > 45 minutes 30 minutes Propylene rubber ⁱ ) about 8 C = / 1000 coals material atoms d) the same Phenyl - /? - naphthylamine ² ) > 45 minutes 33 minutes e) the same Aldol - «- naphthylamine ² ) > 45 minutes 38 minutes f) the same Di-jß-naphthyl-p-phenylene- > 45 minutes > 45 minutes diamine ² ) G) the same N-phenyl-N'-isopropyl- > 45 minutes > 45 minutes p-phenylenediamine ² )

*) Mooney viscosity ML-4: 45 to 55. Unsaturated component: dicyclopentadiene, propylene content about 40 percent by weight

^a ) Discolouring.

^a ) Does not discolour.

*) That means practically the same as the value for the unstabilized rubber I in Table 1.

Table 3

Type of rubber Type of stabilization Time from the beginning of the kneading hand
until reaching the second
Maximum of the torque display
(Viscosity) 1.0 part
stabilizer 0.1 part
stabilizer la)
(Comparison) Unsaturated Ethylene Propylene
Rubber,
about 8 C = / 1000 carbon
atoms ³ ) Di - /? - naphthyl-p-phenylene-
diamine ¹ ) > 45 minutes 35 minutes b)
(Comparison) the same N-phenyl-N'-isopropyl-
p-phenylenediamine ¹ ) > 45 minutes > 45 minutes c)
(Invention) the same N, N-diethylethylenediamine ^a ) > 45 minutes > 45 minutes

*) Discolouring.

*) Does not discolour.

³ ) Mooney viscosity ML-4: 45 to 55. Unsaturated component: dicyclopentadiene, propylene content about 40 percent by weight

Table 4

Type of rubber Type of stabilization Time from the beginning of the kneading hand
until reaching the second
Maximum of the torque display
(Viscosity) 1.0 teü
stabilizer 0.1 teü
stabilizer la)
(Comparison) Unsaturated Ethylene Propylene
Rubber,
about 8 C = / 1000 carbon
atoms ⁸ ) Di - /? - naphthyl-p-phenylene-
diamine ¹ ) > 45 minutes 35 minutes b)
(Comparison) the same N-phenyl-N'-isopropyl-
p-phenylenediamine ¹ ) > 45 minutes > 45 minutes c)
(Invention) the same N, N'-dimethyltrimethylene
diamine ² ) > 45 minutes > 45 minutes

^r J Discolouring.

*) Does not discolour.

^s ) Mooney viscosity ML-4: 45 to 55. Unsaturated component: dicyclopentadiene, propylene content about 40 percent by weight.

Claims (1)

1 253 453 9 Table 5 10 Type of rubber Type of stabilization Time from the beginning of the kneading hand
until reaching the second
Maximum of the torque display
(Viscosity) 1.0 TeU
stabilizer 0.1 TeU
stabilizer la)
(Comparison) Unsaturated Ethylene Propylene
Rubber,
about 8 C = / 1000 carbon
atoms ³ ) Di - /? - naphthyl-p-phenylene-
diamine ¹ ) > 45 minutes 35 minutes b)
(Comparison) the same N-phenyl-N'-isopropyl-
p-phenylenediamine ¹ ) > 45 minutes > 45 minutes c)
(Invention) the same N, N-diethyl aminopropyl
amine ⁸ ) > 45 minutes > 45 minutes *) Discolouring. ') Does not discolour. *) Mooney viscosity ML-4: 45 to 55. Unsaturated component: dicyclopentadiene, propylene content about 40 percent by weight. Claim: Process for stabilizing copolymers of ethylene, an -olefin and at least a polyunsaturated hydrocarbon against the effects of light and heat, thereby characterized in that the stabilizer used is 0.05 to 5.0 parts by weight, based on 100 parts of the rubber, of N, N-substituted diamines of the general formula n - r , - n: R. r ₄
r ₅ used in which r ₁ and r _{2 represent} an alkyl, alkenyl or oxyalkyl _{radical, r 3} an alkylene radical and r ₄ and r _{5 represent} hydrogen, an alkyl or oxyalkyl radical and the alkyl, alkenyl and oxyalkyl radicals have 1 to 16 carbon atoms . Considered publications:
U.S. Patent Nos. 2,891,027, 2,891,029, 959,567. 1 sheet of drawings 709 680/447 10.67 ® Bundesdruckerei Berlin