DE2208845B2 - Compounds curable under shaping - Google Patents

Description

Polymers based on ethylene-propylene copolymers. or ethylene-propylene-diene terpolymers show excellent ozone and UV resistance. Materials made from these substances are therefore used in Used to a greater extent where there is a need for resistance against the effects of the weather is particularly important. To a certain extent, the good weathering properties these polymers by admixing these substances to other, less weatherproof Substances are transferred.

Thus, the patent application 1939 926 describes thermoplastic bitumen compounds whose properties are achieved by adding 0.5 to 25%, in particular 1.5 up to 12%, ethylene propylene rubber can be improved compared to the pure bitumen properties. According to Description of the mentioned laid-open specification is intended to improve improvements that are not defined in more detail mechanical properties as well as an improvement in permanent resistance and UV and ozone resistance be achieved.

The same publication describes masses r-.r. which small proportions, up to 11% of the rubber in üitumen, can be crosslinked with the help of sulfur, which also improves thermoplastic bitumen masses should arise.

In the publication 1946999 similar compositions are described in which an ethylene-propylene rubber is added to the bitumen to improve the properties of bitumen or related substances and then homogenization of the composition is carried out by blowing in oxygen. Bitumen compounds produced in this way and modified with ethylene-propylene copolymers, however, only show improved bitumen properties, ie it is a purely thermoplastic material which, according to information, softens in the heat at relatively low temperatures between about 55 and 105 ° C and therefore for the preparation of Formteilcn as building profiles, sealing profiles, and especially films unsupported not suitable. in order to form such parts of the said raw materials to produce, had to be carried out with mechanical reinforcements, eg. in the manufacture of construction films by using mechanically stronger carrier materials such as textile fabrics, fiberglass fabrics or non-woven materials.

ίο Molded parts of the type mentioned above with good mechanical strength are therefore through vulcanization made from ethylene-propylene-copolymer or ethylene-propylene-diene terpolymer raw materials. Such crosslinked rubbers stand out next to the already

The favorable weathering properties mentioned are characterized by high mechanical tear strengths, by their favorable behavior at low temperatures and their good thermal resistance. In contrast to the previously mentioned bitumen-like thermoplastic materials

Ao fen show these crosslinked ethylene-propylene rubbers elastomeric properties. One disadvantage thicker Materials is the relatively low tear resistance, which means that it is widely used for many molded parts, especially for construction films, stands in the way. The tear strength shows especially then only mediocre Values if carbon black in amounts of more than 100 percent by weight, based on the rubber mass, is used as a reinforcing filler. On the other hand, the rubber types mentioned above Type are particularly highly fillable, this also creates an economic disadvantage (compare e.g. techn.

Report DT / 17 from Cabot GmbH, Groß-Auheirn,

P. 14 and 15).

The elongation at break of cross-linked ethylene propylene

len copolymer or ethylene-propylene-diene terpolymer rubbers on the other hand, with increasing content of active fillers, such as. B. RuD of low particle size and high structure ,, strongly (See Cabot technical report already cited).

* o For certain molded parts, e.g. B. Expansion joints or to bridge cracks, but it is desirable to use a rubber material with a particularly high elastic extensibility to use. The same applies whenever there are strong mechanical alternating loads act on the material.

There is therefore an urgent technical and economic need for molded parts that are made of networked Ethylene-propylene copolymer or ethylene-propylene-di-polymer rubber wcrden and improved tear resistance as well Have extensibility of 400 and more percent up to break.

The invention thus relates to shaping thermosetting compositions for the production of moldings with improved tear strength and increased elongation, consisting of:

A. a rubbery / hylcn-propylcn mixed polymer or a rubber-like ethylene-propylene-thin polymer and

B. 1 to 30 parts by weight, based on 100 parts by weight of component A of the composition, bitumen, whereby the plasticizer oil usually used either completely or partially through Bitumen is replaced.

According to the invention, the crosslinked rubbers with increased tear strength accordingly contain from 1 to 30 parts by weight, preferably from

5 to 20 weight pieces, Hitunicn. Suitable bitumen are especially the commercially available Primilrbitumen nut softening ring and ball between 25 and 60 ⁰ C, and a Penetration 45-600 '/ "ο mm. However, softer Vsr-S cut bitumen, oxidized bitumen, extraction bitumen or vacuum bitumen can also be used.

In order to increase the elongation of the crosslinked material, the normally used aliphatic, naphthenic or aromatic plasticizer oil is wholly or at least partially replaced by bitumen in the vulcanization mixture. The bitumen content should not be higher than the rubber content in the mixture. The Bituroenanteü can also be added in the form of a premix with an Ethylcn copolymer, so z. B. an ethylene acrylic copolymer. Often, vulcanization mixtures made from titanium-propylene-copolymer or ethylene-propylene-poly-rubber are used to denote butyl rubber. The inventiveness so proper use of lower Bilumenanteile in such a crosslinkable mixtures ν ^ IGTE in the described case, the same effect as in mixtures without addition of butyl rubber.

In the disclosure code 1 939 926 already cited it is stated that high amounts of bitumen are likely to prevent rubber from crosslinking. The same reference describes cross-linking attempts of arylene-propylene-diene-terpoly n -.- r-rubber in bitumen, in which due to very high dosed sulfur systems crosslinking oes rubber content in der Bitumenmischur.g 'is to be achieved, again thermoplastic, improved bituminous masses develop. It is not clear to what extent the action of these sulfur systems has one Crosslinking of the rubber portion or, in a known manner, sulfurization of the bitumen and thus causing elasticization of the entire material. at the process of the invention for the production of molded parts from cross-linked! Ethylene Propylene Copolymer or ethylene-propylene-diene terpolymer rubber with improved tear strength and increased elongation, in which mixtures with only a relatively low bitumen content are used, can, as is common in the rubber industry, with the known vulcanizing systems based on Sulfur or peroxide are crosslinked in a known manner. There are no changed procedure conditions Bitumen-free systems are necessary compared to vulcanization.

Moldings produced according to the invention show in general tear strengths that are twice or several times as high as those without addition small amounts of bitumen for the initial mix. The shaping takes place in the usual way before vulcanization Weiss, ζ. Β. by extrusion, calendering or injection molding.

The elongation at break of crosslinked materials produced according to the invention is also not compared to that The basic formulation containing bitumen is significantly increased. With full replacement of the plasticizer oil through soft bitumen, it can be 1000 percent or more, based on the initial value.

As an additional effect, it can be stated on various occasions that when ethylen-propybn or Ethyien-Propylen-Dicn-Tcrpoiynier-FornUcilen made with bitumen are bonded, higher shear strengths result than when the rubber mixture is made without bitumen. In the following examples, the properties of molded parts produced with the addition of bitumen (foils in the present case) are compared with those obtained without the addition of bitumen. From these examples, in addition to the findings made above, it can also be seen that the improvement is above. Further tear resistance and elongation at break is possible with different types of bitumen, depending on whether a softer or harder bitumen is used. It is also shown that mixtures of ethylene-propylene rubber together with other crosslinkable types of rubber, such as butyl rubber, can also be processed according to the invention and give favorable mechanical values compared to zero.

The examples also show that the use of different vulcanization systems has no effect is on the processing of inventive compositions.

The parts given here represent parts by weight. The mixtures are based on 100 parts of rubber. The tear strength (kp / cm ² ) and elongation at break (%) of the molded parts were determined in accordance with DIN 53 455. The values for the tear strength (kp / mm) were determined in accordance with DIN 53 363.

To explain the following examples, the following should be pointed out:

The values given for the tear strength according to DIN 53 363 are comparatively 10 times this high if the information is given in kp / cm (cf., for example, the value in Example 4: Earth tear strength 10.0 kp / mm corresponds to 100 kp / cm).

example 1

Below said components were homogeneously mixed in a conventional manner and then vulcanized after molding by extrusion for 20 minutes at 16O ⁰ C in an autoclave.

75 parts

50 parts

Ethylene propylene diene terpolymer chewing

chuk (propylene content 39.5%, terpoly

0.35 mol / kg ethylidene norbornene),

Ethylene propylene diene terpolymer chewing

chuk (propylene content 35%, terpolymer

0.35 mol / kg ethylidene norbornene, 50%

Oil content related to the rubber),

APF soot,

HAF carbon black with a low structure,

Filler mixture (silica and calcium

calcium carbonate),

naphlhenic oil,

Stearic acid,

Zinc oxide,

Sulfur,

Tramethylthiuram disulfide,

Dipintamethylene thiuram tetrasulfide,

Tellurium diethyl dithiocarbamate.

A film produced in this way had an average tear strength of 77.6 kg / cm ² with an elongation at break of 320% and a tear strength of 3.2 kg / mm.

80 Parts 30th Parts: 45 Parts 55 Parts 1 part 5 Parts 2 Parts 0 , 8 parts 0 , 8 parts 0 , 8 parts

Example 2

The above mixture was before shaping and vulcanization with 5 parts of a soft bitumen with softening point by ring and ball from about 30 ⁰ C and a penetration of about 6001/10 mm at 25 ⁰ C was added (= 1.45% of the total mixture).

After curing for 20 minutes at ioü'C in the autoclave has an average tear strength of 79,4kp / cra ^s was determined mm at a slightly increased elongation at break of 390% and an improved tear strength of 6.5 kgf /.

Example 3 _1S

The rubber mixture given in Example 1 was mixed with 15 parts (-4.3% of the total) of the bitumen already described before molding. After extrusion and vulcanization under the same conditions, a film was obtained with a ^{mean tear strength of 79.7 kg / cm 1} , increased elongation at break of 470% and a further increased tear strength of 7.1 kg / mm.

B c i s ρ i e 1 4

A further increase in the percentage of bitumen to 20 parts (= 5.8% of the total mixture, bitumen as in Examples 2 and 3) of the rubber mixture. ^ Of Example 1 resulted in a slight drop in tensile strength of 6.5 kg / cm after shaping and vulcanization of the material ^s at 480% elongation at break and an even higher tear strength of 10.0 kp / mm.

Example 5

The rubber mixture mentioned below was mixed, calendered and at for 30 minutes 160 ° C ii .. autoclave vulcanized.

25 parts of ethylene-propylene-diene terpolymer rubber (Propylene content 48.5%, terpolymer 0.224 mol / kg ethylidene norbornene),

50 parts of ethylene-propylene-diene terpolymer rubber (Propylene content 27.5%, terpolymer 0.216 mol / kg ethylidene norbornene),

25 parts. Butyl rubber,

90 parts of FEF carbon black,

40 parts of nap'nthermal oil,

1 part stearic acid,
5 parts of zinc oxide,

2 parts sulfur,

2 parts TctramcthyHhiuram disulfide,
i part mercaptobenzothiazole.

Example 7

Further increase of the addition of vacuum bitumen to 5U parts («17.2% of the total mixture) J.cß after calendering and vulcanization in the manner described, the mean value for the tear strength to 35.5 kp / cm ^Ä with increased elongation at break of 535% and increased tear strength of 3.85 kp / mm drop.

Such high additions of harder bitumen are so for the production of z. B. usable construction films no longer suitable because the tear strengths drop too much. This example is intended to limit the Show bitumen additive to increase tear strength and elongation at break.

Example 8

After mixing, the raw rubber mixture described below was shaped by extrusion and vulcanized at 160 ° C. for 30 minutes

50 parts of ethylene propylev. ■ diene-polymer-K.au-

chuk (propylene-based 48.5%, terpoly

mer 0.224 mol / kg ethylidene norbornene), 50 parts of ethylene propylene diene terpolymer K.au-

chuk (propylene content 27.5%, terpoly

mer 0.216 mol / kg ethylidene norbornene),

FEF soot,

naphthenic oil,

Stearic acid,

Zinc oxide,

Sulfur,

Tetramethykhiuram disulfide,

Mercaptobenzothiazole.

The film produced in the manner described showed an elasticity of 119.5 kg / cm ² with an elongation at break of 255% and a tear strength of 2.3 kg / mm.

100 parts
50 parts
Part 1
5 parts
1.5 parts
1.5 parts
0.5 parts

A film produced in this way had an average tear strength of 115.5 kg / cm ² and an elongation at break of 295%. The tear strength was very low at 2.45 kg / mm.

Example 9

The recipe given in Example 8 was varied in such a way that the 50 parts of naphthenic oil were replaced by 60 parts of the above-described W.ichbitumen with a softening point of 30.degree. After shaping by extrusion and vulcanization for 30 minutes at 16O ⁰ C, a film was 58 kgf / cm medium tensile strength, 445% elongation and greatly increased tear strength of 5.6 kgf / mm obtained.

Example 10

Replacement of the 50 parts of naphthenic oil in the procedure according to Example S with 100 parts of the soft bitumen described above resulted in a material with an average tear strength of 55 kp / cm ² at star after extrusion and vulcanization; increased elongation at break of 970% and a tear strength of 5.6 kp / mm.

Example 6

60

25 parts (= 9.4% of the total mixture) of the vacuum bitumen B 130/140 were added to the mixture mentioned in Example 5 and mixed in homogeneously. After Ka'.andrierung and vulcanization ur.tcr the same Bcdiiu i: r. <: Cn as in Example 5, this showed:.: .. ·.: .-, ..! .V ₁ ^ average tear strength of 53.5 kn / cm ² with a crude tear strength of 430% and increased tear strength of 3.9 kp / mm.

Example 11

The basic mixture already described in Example 8 was varied in such a way that the proportion of naphthenic oil was reduced to half and for this purpose 50 Te ₁ Ic of a 1: 1 mixture of bitumen B 80 and an ethylene-acrylate copolymer were added. The material was then deformed by calendering. After curing for 30 minutes at 160 ⁰ C a tear strength of 70 kp / cm ³ at elevated elongation at break of 395% and -.tark increased tear strength of 7.0 kgf / mm was measured.

Claims (3)

Patent claims: 1. Compounds that can be thermally hardened by shaping for the production of moldings with improved weather resistance and increased elongation the end: A. a rubbery ethylene-propylene copolymer or a rubbery ethylene-propylene-diene terpolymer and B. 1 to 30 parts by weight, based on 100 parts by weight of component A of the composition, bitumen, the plasticizer oil usually used being replaced either in whole or in part by bitumen. 2. Thermosetting compositions according to claim 1 for the production of moldings, characterized in that that in addition to the rubbery Ethylcn-Propylene copolymer another crosslinkable rubber is contained in the mixture. 3. Process for the production of molded bodies according to Claims 1 and 2, characterized in that that the bitumen portion in the form of a premix with an ethylene copolymer is added.