CS207704B2 - Mixture for making the tyre tread - Google Patents

Abstract

1514283 Tyre tread compositions BASF AG 24 June [1975 25 June 1974] 26730/75 Addition to 1501922 Headings C3M and C3Q Tyre treads are prepared by vulcanizing in situ on a tyre carcase a tread mixture comprising rubber, filler, stabilizer, 1 to 25 PHR of the resin product of condensing an alkyl phenol with acetylene in a molar ratio of 1 : 1 to 1 : 1À7 or with an equivalent molar amount of formaldehyde or acetaldehyde and 2 to 25 PHR of polyisobutylene of molecular weight of 340,000 to 3,300,000. The exemplied mixture comprises smoked sheet, carbon black, silica, vulcanizing agents, the condensation resin and the polyisobutylene.

Description

BACKGROUND OF THE INVENTION The present invention relates to a tire tread compound having a rubber component.

Such mixtures must have special properties. In particular, adhesion, abrasion stability as well as aging stability (especially when hot) are important properties for which constant improvement efforts are directed.

The technology for producing tires and their components has been described many times, see for example Bostrom "Handbuch der Kautschuktechnologie", then Kleemann "Einfíihrung in die Rezeptenentwicklung der Gummi-Industrie".

It has been found that vehicle tires equipped with auxiliary mechanical gripping means, such as so-called prongs or similar measures, are disadvantageous in many respects. The task now arises to find rubber-based tire compounds which exhibit good adhesion on wet or icy or snow-covered roads, and these have lost their existing advances in the field of tire technology.

Tire compounds with improved grip on wet surfaces are already known. For example, attempts have already been made with polyalkylene glycols as an additive, but these are disadvantageous because they are water soluble and over time they wash out of the tire tread surface.

Compounds have also been tested in which the carbon black as a conventional filler has been replaced wholly or partially with active silicic acid (aerogels), but tires with this filler have a shorter service life.

The purpose of the invention is to improve the properties of tires with a new compound for the manufacture of their tread.

The composition for producing a tire tread with a rubber component according to the invention is characterized in that it comprises a condensation product prepared by condensation of alkylphenol with acetylene in a molar ratio of 1: 1 to 1: 1.7, in an amount of from 2 to 25. % rubber in the mixture.

The composition according to the invention preferably contains polyisobutylene having an average molecular weight in the range from 30,000 to 200,000, in each case in an amount of from 2 to 25% of the rubber in the mixture.

It has been found that a tire tread containing, in addition to the conventional components, i.e. natural or synthetic rubbers, active or other fuels, stabilizers and possibly other components, also a novel composition according to the invention, has substantially improved road grip with virtually all surface properties. .

The addition of the condensation product to the rubber composition on the kneading device or rolling mill can be carried out by any suitable method.

Notwithstanding some of the problems associated with the use of active silicic acid as part of tires, it may be advantageous in some cases to use mixtures of carbon black and silicic acid instead of carbon black as such, for example in a ratio of 20:80 to 80 ·: 20. *

Furthermore, it is advantageous to add a certain amount, for example about 2 to 25, especially 2 to 15% of polyisobutylene, with an average molecular weight of from about 30 to about 200,000, in particular to improve the adhesion of the tire mixtures. Both additives seem to have an independent effect on the adhesion, so that there is an additional advantage over the actual addition of the condensation resin and the polyisobutylene in each case.

The condensation product or condensation resins for the purposes of the present invention are condensation products which can be prepared in a known manner from, for example, tert-butylphenol and acetylene or other alkylphenols, for example 2-ethylhexylphenol, as well as compounds which behave similarly to -acetylene. for example, such as acetaldehyde and optionally formaldehyde. The preparation of such compounds is described, for example, by Marvel, Gander and Chambers in J. Poly. Sci. 4,669-702 (1949), and in connection specifically with this problem, reference is made herein.

Condensation resins of the type mentioned are, for example, obtainable under the trade names Koresin (manufacturer BASF Aktiengesellschaft, Ludwigshafen).

The rubber (elastomers) suitable for the tire compositions of the present invention are, for example, natural rubber or rubber. diluted with oil, styrene-butadiene rubber, optionally. oil-diluted, cispolybutadiene, cis-polyisoprene; Depending on the application, for example, for the treads of passenger cars, industrial vehicles - or trucks - different base mixtures are used.

Possible active fillers in the context of the present invention are, for example, carbon black, such as carbon black from HAF, ISAF, SAF, and the like carbon black, and silicic acid; silicic acid is most conveniently used with certain so-called activators, for example of the type-certain -organosilanes-containing-sulfur.

Pre-aging agents which are particularly useful in the context of the present invention, and in particular have a beneficial effect on the properties of the rubber compositions obtained, include: p-phenylenediamine (i derivatives), phenylnaphthalines, phenol (and derivatives) quinoline (and derivatives).

Applicable anti-aging agents - They are described, e.g. lähde: Voigt a Die- Stabilicierung der Kunststoffe gegen Licht und Wämme, Springer, 1966, Berlin. In this connection, reference is also made to the aforementioned book by Kleemann, where the use of existing rubber auxiliaries is also discussed.

Appropriate measurements were made on vulcanized rubber discs having a thickness of 6 mm and a diameter of 60 mm. Various substrates were used as substrates, the character of which was adapted to correspond to street and road surfaces, and measurements were carried out at room temperature, as well as in the range of 0 ac to -25 ° C. The measuring device is shown schematically in the attached figure, where the numerical designations mean:

la = rubber disc lb = ice layer lc = road surface 2 = load weight 3a, b, c = temperature measurement = aeration = hygrometer

6a, b = load cell 6c = -oscilograph 8 = air-conditioning package

The rubber disks are subjected to normal forces of 50, 100 and 150 N. The disks move evenly by rotating the threaded spindle at a lower sliding speed without tearing. A force transducer ring is built into the tensile system by guiding it in a straight line, the collapse of which is inductively measured and measured on the oscillograph as a measure of the friction force.

The friction coefficient is calculated from:

R where R is the friction force (Newton) N = -m. g ~ -normal force m Mass of the load body in kg g = Earth acceleration in m

• s2

Example 1

Test compound (car tires)

AND (B) C cf. rubber (Buna Hiils 1500) 40 ........ 40 40 40 rubber (Buna CB) 60 60 60 60 carbon black N 220 50 50 50 50 naphthalene, plasticizer 10 10 10 10 4010 NA 1 1 1 1 phenyl-5S-naphthylamine 1 1 1 1 zinc oxide 3 3 3 3 stearic acid 1.5 1.5 1.5 1.5 sulfur 1,8 1,8 1,8 1,8 Vulk. CZ 1,2 1,2 1,2 1,2 Vulk. D 0.2 0.2 0.2 0.2 condensation resins (Koresin) 1 3 5 - Physical data (vulcanization 20 min / 151 ° C) AND (B) C cf. Module (300% kp / cm ² ) 95 83 75 97 strength (kp / cm2) 146 146 166 155 elongation (%) 412 450 514 426 Hardness (° Shore A) 63 61 59 62 abrasion, standard (mm ³ ) 43 36 38 40 Results (coefficient of friction) Load 50 N Fine asphalt, dry 1.08 1,23 1.17 1.04 wet 1.18 1,21 1.13 1.05 Coarse asphalt, dry 1,21 1.37 1.33 1.19 wet 1.00 1.05 1.09 0.92 Concrete dry 1.38 1.48 1.59 1,25 wet 0.90 1.12 1.19 0.88 Basalt, wet 1.13 1.13 1.13 1.06 dry 0.77 0.73 0.69 0.61

Example 2

Test compound · (tires for: trucks)

And cf.

Rubber (smoked RSS1) 40 40 rubber (Buna CB) 60 60 silicic acid 65 65 silicic acid activator (Degussa X 50) 65 65 zinc oxide 5 5 stearic acid 2 2 naft., plasticizer 12 12 phenyl- 3-naphthylamine 1 1 phenyl-α-naphthylamine 0.5 0.5 anti - aging agent 0.8 0.8 sulfur 1.75 1.75 Vulkacit CZ 1 1 Vulkacit D 1.3 1.3 Condensation Resins (Koresin) 5 -

cf.

Physical data (vulcanization 40 min / 151 ° C) modulus (300% kp / cm ² ) 48 strength (kp / cm ² ) 149 ductility ( ¹⁰ / o) 708

Hardness (°, Shore A) 67 abrasion, stand. (mm ³⁾ 64

164

664

Results (coefficient of friction)

Load 50 N Asphalt

dry 22 ° C 0.87 0.77 22 ° C 0.87 0.66 Ice on asphalt 5 ° C 0.12 0.06 - 10 ° C 0.20 0.08 - 15 ° C 0.16 0.08 —20 ° C 0.37 0.32

Example 3

Test compound (truck tire)

А В cf.

Rubber (smoked RSS1) 40 40 40 rubber (Buna CB) 60 60 60 carbon black N 220 35 35 35 silicic acid 27 Mar: 27 Mar: 27 Mar: silicic acid activator (Degussa X 50) 6 6 6 zinc oxide 5 5 5 stearic acid 2 2 2 naphthenic plasticizer 12 12 12 phenyl- N -naphthylamine 1.5 1.5 1.5 - protective means against aging 4010 NA 0.8 0.8 0.8 sulfur 1.75 1.75 1.75 Vulkacit CZ 1 1 1 Vulkacit D 1 1 1 Polyisobutylene (Oppanol В 50) - 10 10 phenolic resin (Koresin) 5 5 - Physical data (vulcanization 30 min / 151 ° C) Module (300% kp / cm ² ) 49 46 67 strength (kp / cm ² ) 169 139 178 elongation ('%) 674 636 590 Hardness (° Shore A) 52 50 57 oder, stand. (mm ³ ) 58 70 62 Results (coefficient of friction) load 50 N Basalt smooth, dry Deň: 18 ° C 2.1 2.1 1.80 Basalt wet 22 1.13 1,23 1.09 Smooth icing 5 ° C 0.58 0.56 0.51 - 10 ° C 0.63 0.67 0.56 —15 ° C 0.87 0.89 0.77 —20 ° C 0.95 0.98 0.89 —25 ° C 1.05 1.08 0.89

Claims (2)

SUBJECT OF THE INVENTION A composition for producing a tire tread with a rubber component, characterized in that it comprises a condensation product prepared by condensing alkylphenol with acetylene in a molar ratio. 1: 1 to 1: 1.7 in an amount of from 2 to 25% of the rubber in the mixture. ' 2. A composition according to claim 1, characterized in that it comprises polyisobutylene having an average molecular weight in the range from 30,000 to 200,000, in each case in an amount of from 2 to 25% of the proportion of rubber in the composition.