DE2107537A1 - Elastomeric mass - Google Patents

Description

2107537 Andrejewski & Honke patent attorneys

Attorney's file: 36 350 / Ti Physicist Dr. Walter Andrejewski Graduate engineer

Essen, February 15, 1971 Kettwiger Strasse 36 ( ^th )

Patent application

BRIDGESTONE TIRE COMPANY LIMITED
1-1, 1-chome, Kyobashi, Chuo-ku,
Tokyo / - Japan -

Elastomeric mass.

The invention relates to an elastomeric composition made from a copolymer of styrene and butadiene with an additive, which in particular for the production of the running surfaces of driving I is intended to give them an improved cutting resistance.

When driving on unpaved roads, especially stony ones Paths with a sharp-edged surface become the tread of the tire often damaged by the sharp edges of the rock, gravel or the like, so that more or less deep cuts in the Running surface arise and from this more or less large

109837/1481

Patent attorneys Dr. W. Andrejewski, Dr. M. Honke, 43 Essen, Kettwiger Strasse 36

Particles are torn off. As a result, the tire industry has long tried to find new ^ and to develop improved materials for the tread of large tires for heavy goods vehicles, buses and also for construction site vehicles, such as in gravel pits, in order to to avoid such injuries to the tread, which very often lead to tire breakages with their often catastrophic pole pieces.

In the development of such new substances or mixtures, however, great difficulties have arisen because of the relationships between the cutting strength and the physical properties of vulcanized rubber by laboratory tests Determination of the cutting resistance and the like. Were not clearly determinable. But it could now be established that a sharp-edged stone, gravel or the like. Which at relatively high speed and high load on the vehicle under the tread of the tire gets, briefly penetrates into the tread and damages it. The applicant is therefore of it assumed to increase the cutting resistance of the tread of a tire by reducing the wear and tear at high speeds improve which in the case of a reproduction of the cuts in the tread in wear tests carried out on the test stand can be observed at speed. The speed in question here is 5 m / sec (18 km / h), which is βθθ times the speed (500mm / min) at ordinary Rubber strength tests as specified in Japanese Industrial Standard (JIS) No. K-6301. As from the Publication by G. Fromandi, R. Ecker and W. Heidemann in "Kautschuk und Gummi", Volume 13, WT 25, 1960 is known

1C3837 / US1

Patent attorneys Dr. W. Andrejewski, Dr. M. Honke, 43 Essen, Kettwiger Strasse

no relationship between such two speeds in Regarding the wear properties. In the speed wear tests To reproduce the cuts, a metal blade was inserted into the tread at high speed bumped, except for those during speed wear tests usual measurements also the cuts were taken into account. After those were found out of numerous material mixtures, which a laboratoriua. Moderately as satisfactory ascertainable wear resistance | showed at high speeds, these mixtures were subjected to real driving tests on bad roads, in order to develop the compounds for the tread which have the desired cutting strength.

Extensive attempts have been made with elastomers such as natural rubber and styrene-butadiene rubber (the latter hereinafter referred to as SBR) and carbon blackness performed. It's general known that an addition of a great deal of carbon blackness to it the rubber compound on the one hand can improve the cutting resistance, but on the other hand the tread of such a mixture can be worsened in other properties, as they are particularly necessary on bad roads, e.g. off- * sufficient tear resistance, elasticity, exothermic behavior and processability. From this point of view, 40-50 Parts by weight of carbon black 100 parts by weight of natural rubber respectively 50-60 parts by weight added to SBR, but gave even these compromising blends do not give satisfactory results in terms of the desired cutting strength the treads.

BADORKSINAL

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Patent attorneys Dr. W. Andrejewski, Dr. M. Honke, 43 Essen, Kettwiger Strasse

Further tests produced the surprising result that some petroleum resins, especially cyclopentadiene or des dicyclopentadiene, when used instead of the usual carbon black, the wear at high speeds significantly reduced and consequently the cutting resistance of the treads significantly improved.

An elastomeric composition according to the invention with improved cutting resistance is characterized in that it contains 5-40 parts by weight of a petroleum resin per 100 parts by weight of an elastomeric copolymer of styrene and butadiene, the petroleum resin being composed of polymers of cyclopentadiene and / or dicyclopentadiene and copolymers of cyclopentadiene and / or dicyclopentadiene and an olefin hydrocarbon copolymerizable therewith and the cyclopentadiene and / or the dicyclopentadiene makes up more than 30 % by weight of the mixture. make up, wherein the softening point of the petroleum resin is 5-200 ⁰ C, preferably 80-15O ° C, and the bromine value of the petroleum resin is 40-150.

It is particularly surprising that such an additive is also excellently suited as a plasticizer. To improve workability A wide variety of plasticizers have hitherto been used in the elastomeric mixtures, but their addition is often used Destroyed or at least reduced the physical properties of the vulcanized rubber, as the softener himself not only did not have elasticity, but there was also no reaction of the same with the rubber compound. That according to the invention petroleum resin used can not only be used for processing

109837 / U61

Patent attorneys Dr. W. Andrejewski, Dr. M. Honke, 43 Essen, Kettwiger Strasse

ability of rubber as a plasticizer in not yet vulcanized Conditions of the rubber compound contribute, but it can also improve the elastomeric properties of the compound, which possibly based on the chemical reaction or the mutual physical effect with the actual rubber compound is. In contrast to the machining oils customary up to now, this can be done essentially from cyclopentadiene or dicyclopentadiene existing petroleum resin according to the invention, the tensile strength at high speeds and the cutting strength f The ability of the elastomeric mixture to be improved considerably without affecting the processability and the exothermic behavior were disturbed. Such an effect was different from the usual Do not expect plasticizers or machining oils.

This is possibly due to the secondary weak bond of the petroleum resin in the elastomeric compound, whose Shore hardness and low tensile stress are higher than in the case of the conventional elastomeric compounds mixed with the usual machining oil, in which the main bond of rubber / rubber and rubber / carbon blacks is detected. Such weak binding would break when the tensile stress at normal velocity g ness increases from 500 mm / min, however, would be quite sufficient to a short-time deformation counteract, particularly at voltages at high speed or impact, whereby the wear resistance of the tread compound at high Speed would be increased and the sharp edge of the metal blade or stones would be prevented from cutting into the tread.

109837/1461

Patent attorneys Dr. W. Andrejewski, Dr. M. Honke, 43 Essen, Kettwiger Strasse

The olefin hydrocarbons used in the mixture according to the invention include, for example, monoolefinic aliphatic hydrocarbons such as, for example, 1-butylene, 2-butylene, isobutylene, 1-pentene, 2-pentene, 2-methyl-1-butylene, 3-methyl-1-butylene Butylene, 2-methyl-2-butylene; diolefinic aliphatic hydrocarbons such as butadiene, isoprene, 2-methyl-1,3-butadiene, Iy3-pentadiene, 3-methyl-1,2-butadiene; and vinyl substituted aromatic hydrocarbons such as styrene, p-vinyltoluene, m-vinyltoluene, o-vinylfeoluene, & -methylstyrene, 3-methylstyrene, m-ethylstyrene, p-ethylstyrene, indene, 3-methylindene, 1-vinylnaphthalene, 2- Vinyl naphthalene each of which is copolymerizable with cyclopentadiene or dicyclopentadiene by means of Friedel-Crafts reaction, etc. in the presence of a suitable catalyst.

However, these petroleum resins have a softening point (according to the ring and ball test in accordance with JIS K-5902) of 50-200 ⁰ C and preferably from 8O-15O ° C and a bromine value (ASTM D-II58-57T) of 4O I5O and preferably 50-150 in view of the molecular weight and reactivity of the double bond in order to achieve the desired physical properties of the vulcanized rubber.

Natural rubber, polybutadiene rubber, SBR and the like can be used as the elastomeric element for the mixture of the present invention, but the combination with SBR shows particularly excellent wear resistance at high speed, from which it can be seen that in addition to the reaction of sulfur with the petroleum resin, also during vulcanization the mutual 9Γ " electron effect between the cyclopentadiene ring and styrene plays a role. As a result, the petroleum resin according to the invention plays a special role in connection with SBR.

109837 / U61

Patent attorneys Dr. W. Andrejewski, Dr. M. Honke, 43 Essen, Kettwiger Strasse

With regard to the workability of the not yet vulcanized Material and the desired properties of the tread compound should be the petroleum resin in an amount of 5-40 parts by weight, in particular 5-20 parts by weight, with 100 parts by weight of SBR are mixed.

If the elastomeric composition of the invention is intended particularly as a material for producing the running surfaces of vehicle tires, so this mass can of course also for other items d 'use where a corresponding cut-resistance is required. Two examples are intended to explain the invention in detail below.

example 1

The composition of the elastomeric compositions of the invention composed of cyclopentadiene petroleum resin and SBR is shown below Table 1 shown in comparison to the compositions combined with aromatic machining oils and coumarone-indene resin are commonly used as plasticizers in SBR. When wax, antioxidants and vulcanization accelerators were used | the usual substances used in the manufacture of tread compounds used. The ratios given are in their entirety parts by weight.

The individual components were in the usual catfish with a Bumbüry mixer No. 11 mixed together. The physical properties in terms of hardness, tensile strength at 500mm / min

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Patent attorney Dr. W. Andrejewski, Dr. M. Honke, 43 Essen, Kettwiger Strasse

and the peel strength were determined in accordance with JIS K-6J5O1 measured. The speed tensile strength tests at 5 m / sec were carried out in accordance with DIN No.J5 with test pieces made of 2 mm thick vulcanized material using a Plastecon tensile tester carried out. The impact cutting tests were carried out in such a way that a steel blade of the pendulum impact tester was driven into the specimen to determine the depth of the cuts. The information Regarding the appearance of the tread, measurements are taken after a running time of 2200 km on stony paths in the gravel pit with frequent sudden braking, whereby the Tires had a dimension of 1,000-20 for the motor vehicle and each had a tread of four parts, each of which were made from four different tread compounds, namely two tires with four tread parts of the compounds X-A-B-D and the other two tires with the compounds X-C-D-E.

109837 / U61

Patent attorneys Dr. W. Andrejewski, Dr. M. Honke, 43 Essen, Kettwiger Strasse 36 Table 1

SBR-I500 100 2 - 3 , 6 100 2 3 100 2 3 500 mm / min: 590 580 , 6 100 2 3 , 6 100 2 , 6 15th 3 , 4 Natural rubber - HAF carbon base 6θ Cyclopentadiene resin A ^xx - 3 - 60 3 - 60 3 242 212 - 60 3 - 60 85 3 , 5 Stearic acid Esso machining oil H-2 20 H tjXXX
~ τ £ 3 - - 10 19.7 20, - - 3 Kumaron BM * Wax and antioxidants 1; 20th 1.6 - 1, 4th 103 91 - 1, - 45 0, ZnO 2 - 2 10 2 61 58 20th 2 - 10 2, Vulcanizing 60 - 63 - 64 m / sec: - 67 20th - 57 accelerator from 5 745 680 , 3 , 4 3 .5 - , 2 sulfur 530 181 188 630 3 - 520 Hardness (Japanese Indian standard) 205 119 121 215 267 At train speed 18 26.2 14, 2I ₁ 1, 17, Strain (#) 87 4th 92 2 83 Tensile strength (kp / cm) 54 • 3.3 1, 62 68 85 100 % module (kp / cm ² ) from 5 9.6 6, 300 % - "τ (kp / cm ² ) 705 4th 3.3 2, 7th 680 6th 600 3 690 1 Tensile strength (kp / cm ² ) 170 2 195 202 161 At train speed 100 9 134 6th 21 5 85 3 Strain (#) 30, 4th 0, 4th 88 6th 28, 2 Tensile strength (kp / cm) XXX3? 8th 8th 61 0 1 300 % module (kp / cm ² ) 3, 0, 3, Sohlag cutting test (mm) 14, 3, 675 11 Appearance of the tread 4, 0, 193 6, Big cuts 129 Small - " - 1, cutlet 0, 4, 1,

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Patent attorneys Dr. W. Andrejewski, Dr. M. Honke, 43 Essen, Kettwiger Strasse

- 10 -

In the above table 1:

A coumarone resin from the Pa. Ohuchi Shinko Kabushiki Kalsha with

21;

with a softening point of 72 C and a bromine value

xx A copolymer of about 50 % cyclopentadiene, about 40 % aromatic hydrocarbons and about 10 % other olefins, with a softening point of 105 C and a bromine value of 99;

xxx A copolymer of about 70 % cyclopentadiene and about 50 % other olefins, with a softening point of 102 ° C. and a bromine value of 107;

xxxx The number of cuts and chips per 100 cm of running surface after the running test, whereby "large cuts" those with a cutting depth of over 5 mm, "small Cuts "those with a depth of between 1 and 5 mm and" Schnitzel "torn treads

P.
pieces of more than 25 mm mean

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Patent attorneys Dr. W. Andrejewski, Dr. M. Honke, 43 Essen, Kettwiger Strasse

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As can be seen from the table above, the cyclopentadiene resin carries Compared to the usual machining oil and coumarone resin, it significantly improves the cutting resistance of the elastomeric mass. It is also found that the invention elastomeric compound made from SBR and cyclopentadiene petroleum resin the usual natural rubber compound (E) mixed with the same resin is strong in cutting resistance is superior.

Example 2

As in Example 1, the mixtures and tests were carried out in the same way, but with the appearance of the Tread indicated as the result of driving tests with tires one of which is a tread made from the four mixtures X-P-G-H and the other is a tread made from the mixtures X-I-J-K owned.

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Patent attorneys Dr. W. Andrejewski, Dr, M. Honke, 43 Essen, Kettwiger Strasse 36

- 12 -

X Table 2 P. G H I. J K 100 100 100 100 100 100 100 SBR 1500 2 2 2 2 2 2 2 Stearic acid 60 60 60 60 60 60 60 HAP charcoal
blackness 20th Esso edit
processing oil H-2

Cyclopentadiene resin C ^x

20th

_ J)

XX

20th

XXXXXX

Wax and

Antioxidants

Vulcanization accelerator

sulfur

3
3

1.6

3 3

1.6 2

3 3

1.6 2

At a pulling speed of 5 m / secs

Elongation (#) 670 69Ο tensile strength

(kp / cm ² ) 172 194 300 % modulus

(kp / cm ² ) 95 108

Punch-cutting
Test (mm)

21.5 2.6

Appearance of the tread ^

"l, l 5.2

Large cuts 4.9 Small - "- 18.2 Schnitzel 3.1

0.4

690 196 110

3.2

1.1

6.1

o, 3

660 195 121

20th

3
3

1.6
2

660
205
123
0.7

0.7

3.4

0.5

3 3

1.6 2

710 168

20th

3 3

., 6

630 180

91

18.4 15.1

4.0 4.1

15.4 1 ^, 9

2.4 3.5

1 0 9 8 3 7 / U 6

Patent attorneys Dr. W. Andrejewski, Dr. M. Honke, 43 Essen, Kettwiger Strasse 36

- 13 -

In the above table 2:

A χ cyclopentadiene resin having a softening point of 148 ⁰ C and a bromine value 131;

xx A copolymer of about 50 % cyclopentadiene, about 10 % aromatic olefins and about 40 % other olefins, with a softening point of 72 ° C and a bromine value of 115;

xxx A copolymer of about 35 % cyclopentadiene, about 55 % aromatic olefins and about 10 % other olefins, with a softening point of 109 ° C and a bromine value of 59;

xxxx A copolymer of about 85 % cyclopentadiene and about 10 % aromatic olefins, with a softening point of 145 ° C. and a bromine value of 122;

xxxxx A copolymer of about 15% cyclopentadiene, about 25% aromatic olefins, and about 60% of other olefins, having a softening point of 42 ⁰ C and a bromine value 97;

xxxxxx A copolymer of about 10 % cyclopentadiene and about 90 % aromatic olefins, with a softening point of 15I ⁰ C and a bromine value of 31

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Patent attorneys Dr. W. Andrejewski, Dr. M. Honke, 43 Essen, Keftwiger Strasse

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From this Table 2 it can be seen that the cyclopentadiene petroleum resins Improve the sonic strength of the SBR mixtures, but if the amount of resin is too low or the bromine value is too low or too low a softening point of the resins, the effect, as the mixtures j and K show, is worse than in the compositions according to the invention, albeit cyelopentadiene petroleum resins still give better results than the usual additives.

Expectations;

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Claims (4)

Patent attorneys Dr. W. Andrejewski, Dr. M. Honke, 43 Essen, Kettwiger Strasse 1S Claims. 1. Elastomeric composition with improved cutting resistance, characterized in that it contains 5- ^ 0 parts by weight of a petroleum resin to 100 parts by weight of an elastomeric copolymer of styrene and butadiene, the petroleum resin of polymers of cyclopentadiene and / or dicyclopentadiene and copolymers of cyclopentadiene and / or dicyclopentadiene and a copolymerizable olefin ^ is hydrocarbon and cyclopentadiene and / or dicyclopentadiene more than λ BEZW constitutes 50 weight ^ of the mixture. turn off. 2. Elastomeric composition according to claim 1, characterized in that the softening point of the petroleum resin is 50-200 ° C, preferably 8O-150 ° C. 5. Elastomeric composition according to claim 1, characterized in that that the bromine value of the petroleum resin is 40-150. 4. Elastomeric composition according to claim 1, characterized in that it contains 5-20 parts by weight of the petroleum resin per 100 parts by weight of the elastomeric copolymer of styrene and butadiene. Ä Patent attorney. 109837/1461