DE4005493A1 - Rubber compsns. partic. for running surfaces of tyres - for use on icy or snowy roads contain powdered leather or gelatin - Google Patents

Abstract

Rubber compsns. contg. leather powder (I) are claimed. Also claimed are: (1) rubber compsns. contg. gelatine powder with average particle size less than 500 microns. (2) Tyres with running surface of vulcanised rubber, cells having average aspect ratio up to 0.7 and prepd. from rubber compsn. contg. gelatine. (3) Spike-less winter tyres having running surface prepd. from rubber compsn. contg. (I) having reticulate and/or papillary layer with hierarchial structure of fibres of collagen protein. USE/ADVANTAGE - For soles and partic. tyres esp. for icy and snow-covered roads. Tyres have good abrasion resistance on usual road surfaces and improved sliding resistance on snow and ice.

Description

The invention relates to rubber compounds and tires that for ordinary cobbled streets, but especially for icy and snow-covered roads are suitable.

Spike tires, the spikes implanted in the tread are often used to operate motor vehicles applied to icy roads, however, have the disadvantage a strong development of noise, damage to the streets area and the associated dust development. It will therefore increasingly spike-less winter tires are used however, problems with abrasion resistance and Prepare heat.

It has already been suggested that the rubber be short Mixing fibers, however, this mixture is unfavorable in terms of abrasion resistance and durability. The Profile rubber has also been added to salt Form cells in the tread. The presence However, salt has the disadvantage of corrosion of the Steel cords. Foam rubber is easy to use producing organic or inorganic blowing agents, however, it has proven extremely difficult Foaming process in connection with the Vulcanizing speed, temperature and viscosity of the Regulate rubber and vulcanizing pressure.

The aim of the invention is to provide a rubber compound for tires and to provide soles that are particularly suitable for icy and snowy roads. goal of The invention is also the provision of tires with good abrasion resistance on ordinary roads have improved slip resistance on snow and ice.

The invention relates to a rubber composition material derived from leather, preferably leather powder, contains.  

The invention further relates to a rubber composition, the gelatin powder with an average particle diameter contains less than 500 µm.

The invention also relates to a tire which is characterized by a tread made of vulcanized Rubber, the cells with a medium axis ratio (English: aspect ratio) of up to 0.7 contains and from a rubber composition has been produced, which Contains gelatin.

The invention further relates to a spike-less Winter tire, which is characterized by a Tread that has been made from a Rubber composition, which contains a leather powder, the one Reticular layer and / or a papillary layer with a hierarchical structure of fibers from collagen protein having.

Leather mainly consists of collagen protein, the is a natural high molecular substance. Collagen protein has good low temperature properties and its molecules show unique, complex micro and Macrostructures. These characteristics and the ecology of Vertebrates in cold climates appear on it point out that collagen protein has good slip resistance lends on ice.

Extensive investigations have therefore attempted to Leather and rubber a rubber-like, viscoelastic composite material with excellent To create slip resistance on ice.

Because of the favorable distribution of hydrophilic and hydrophobic groups in the molecule Ability to absorb and release moisture. Extensive investigations have therefore attempted to  Gelatin and rubber are a rubber-like, elastic Composite material with excellent slip resistance Making ice cream.

As a rubber component of the invention Rubber compounds or tire treads are suitable for Example natural rubber (NR), butadiene rubber (BR), Styrene-butadiene rubber (SBR), isoprene rubber (IR), Butyl rubber (IIR) and mixtures of these rubbers.

In a first embodiment, the rubber composition according to the invention a leather powder. Even though Various leather powders are preferred Powder of beef, horse, pig, goat and Sheep leather applied. The leather powder has one Water content of preferably less than 25% by weight, in particular about 3-20% by weight. The blended amount of Leather powder is preferably about 3 to 50, especially about 5 to 30 parts per 100 parts of the Rubber component. Here and in the following refer all parts by weight.

The leather powder preferably has a medium one Particle size of up to 300 microns, especially about 3 to 100 µm. With an average particle size of more than 300 µm is the dispersibility of the leather powder in the Rubber compound somewhat affected and the Particle surface and reinforcement are something less favorable.

In a second embodiment, the Rubber composition gelatin according to the invention with a average particle size of preferably less than 500 μm, in particular about 20 to 450 microns. If the particle size is not smaller than 500 µm, shows the vulcanized Rubber has slightly improved slip resistance Ice, but deteriorated abrasion resistance. The the amount of gelatin added is preferably about 3 to  50 parts, especially about 5 to 40 parts per 100 parts the rubber component.

If you mix gelatin with the rubber to make it physically and to produce a composite material chemically, so effect the excellent low temperature properties of the Gelatin as a natural high molecular substance Reduction in the increase in hardness of the rubber composition and thus an improved coefficient of friction low temperatures. If you use one Rubber compound for tire treads and soles, see above their coefficient of friction improves especially in Presence of a quasi-liquid layer on ice at -5 ° C.

In a third embodiment, the invention relates a foam tire made from one Composite material made of rubber and gelatin as a natural high molecular substance and the microporous open Cells together with a characteristic structure which, by reaction on the rubber gelatin Interface arises. Submit the mixture Rubber and gelatin of a vulcanization, so apparently the gelatin partly at high temperature denatures and forms microporous open cells. Furthermore gelatin has the ability to absorb moisture and release as they are both hydrophilic and has hydrophobic groups in the molecule. Based on these Between the tire tread and water film present in the ice through the cells quickly eliminated and causes an ionic surface activity a higher friction between the tread and the icy or snow-covered road surface.

In this tire according to the invention, the average particle size and the amount of gelatin respective values in the second invention Embodiment. The cells obtained have a medium one Axis ratio (short axis / long axis) of up to  0.7. The axis ratio is determined by a cross section of the tread rubber of a test tire under an optical microscope with a magnification of about 300 × photographed, the length of the short or long one Axis of about 100 cells and measures the arithmetic mean of the axis ratios of these cells. At a The tire has no axis ratio above 0.7 satisfactory slip resistance on ice and snow.

In a fourth embodiment, the invention relates a tire whose tread is made of a rubber compound is produced, which contains a leather powder, wherein the leather has a reticular layer and / or a Papillary layer with a hierarchical structure of Collagen protein fibers included. Although different Types of leather can be used is leather from cattle, horses, Pigs, sheep and goats preferred. The Leather used according to the invention provides the Reticular layer and / or papillary layer of the leather. The leather can also have the epidermis, however is preferably not present. The leather powder will preferably in an amount of about 3 to 50 parts, especially about 5 to 30 parts, per 100 parts of rubber used.

The papillary layer and the reticular layer, which the Most of the leather is made up of mainly from collagen protein with amino acid groups. This protein has a hierarchical structure of high complexity. Collagen has a molecular weight of approximately 300,000 and the molecule is rod-shaped with a length of about 3000 Ångström and a diameter of about 15 Ångström. Such molecules regularly associate themselves Microfibrils, and the microfibrils in turn associate via covalent bonds within and between the collagen molecules to form insoluble fibrils. The fibrils associate themselves a fiber observed under an optical microscope  can be. The fibers form bundles of fibers, which Have diameters of up to about 500 microns, while the Fibrils only have a diameter of 50 to 200 nm. Leather therefore has a complex hierarchical structure. In the tire according to the invention, collagen protein is added Tread rubber added to tiny in the tread To generate waves. Although collagen protein mainly consists of superfine fibers, reduces its hierarchical structure during the orientation of the fiber the molding and vulcanization of the rubber, so that the Protein retains its flexibility and a cheap one Friction coefficient of the tread against ice and Snow causes. Because collagen protein is also its Flexibility preserved even at low temperatures and due to the amino acid groups hydrophilic properties the presence of this protein enables one maintaining the frictional force of the tire more effectively on frozen roads than when adding conventional ones synthetic fibers.

According to the invention, the rubber compositions conventional additives are of course added, e.g. Vulcanizing agent, vulcanization accelerator, Auxiliary vulcanization accelerator, vulcanization retarder, Reinforcing materials, fillers, antioxidants, Tackifiers and colorants. Examples of suitable ones Fillers are carbon black, silicon dioxide, clay and Calcium carbonate. These fillers are available in quantities of usually 20 to 150 parts, preferably 30 to 100 parts Parts, used per 100 parts of rubber.

The rubber compositions according to the invention can by Compounding the components mentioned in the usual Devices, e.g. Roller mills, Banbury mixers or Kneaders.

The tires according to the invention can be produced using customary methods using the rubber compositions according to the invention  made for the tread and profile area will.

The rubber compositions according to the invention have excellent low temperature properties and are suitable especially for icy and snowy roads. The same applies to the tires according to the invention, the high one Abrasion resistance and excellent Have low temperature properties.

The following examples illustrate the invention. All Parts refer to the weight.

Example A and Comparative Example A

100 parts of the rubbers mentioned in Table 1, the stated amounts of carbon black (N 339) and leather powder, 30 parts of naphthen oil, 3 parts of zinc oxide, 2 parts of stearic acid, 1 part of antioxidant (N- (1,3-dimethylbutyl) -N'- phenyl-p-phenylenediamine), 1 part paraffin wax, 1.4 parts vulcanization accelerator (N-cyclohexyl-2 benzothiazylsulfenamide) and 2 parts sulfur are mixed for 4 minutes in a Banbury mixer to a rubber mass, which is then in a mold at 160 for 20 minutes ° C is vulcanized. The hardness of the mass is measured according to ASTM D 2225 at -15 ° C and 23 ° C. The difference between the two values is expressed as Δ hardness. The smaller the value, the better the low temperature properties. Ice skid resistance is measured at -5 ° C and -15 ° C using a Stanley London portable skid resistance tester. The property is expressed as an index based on the slip resistance of the rubber composition No. 14, which is assumed to be 100. The higher the value, the better the slip resistance on ice. The BR rubber used has a high cis content and the SBR rubber is solution-polymerized SBR with a styrene content of 10%. The results are shown in Table 1. Compositions 1 to 11 are according to the invention, the other comparative examples.

Table 1

Table 1 (continued)

Example B and Comparative Example B

The procedure of Example A is repeated, however 100 parts of those mentioned in Table 2 are used Rubbers, 70 parts of carbon black (N 339), the stated amount Gelatin powder, 50 parts naphthenic oil, 3 parts zinc oxide, 2 Parts of stearic acid, 1 part of antioxidant, 1 part Paraffin wax, 1.4 parts vulcanization accelerator and 2 parts of sulfur. The slip resistance is expressed as an index, based on mass No. 24, which is 100 Is accepted. The BR rubber used has one high cis content and the SBR rubber is Solution polymerized SBR with a styrene content of 10%. The results are shown in Table 2. The crowds Nos. 16 to 22 are according to the invention, the rest Comparative examples.  

Table 2

Example C and Comparative Example C.

A rubber compound is made from 100 parts of the Rubbers mentioned in Table 3, the amounts indicated Carbon black (N 339), gelatin and naphthen oil, 3 parts zinc oxide, 2 Parts stearic acid, 2 parts antioxidant, 1 part Paraffin wax, 1.7 parts vulcanization accelerator and 1.7 parts of sulfur by adding the ingredients for 4 minutes mixes in a Banbury mixer. 165/80 tires R13 are used according to the usual procedure the mass obtained for the tread. The Mass No. 33 contains no gelatin. For mass No. 34 becomes a blowing agent (dinitrosopentamethylene tetramine) used instead of gelatin.

The rubber mass obtained is 20 minutes in one Mold vulcanized at 160 ° C. The hardness becomes at -5 ° C ASTM D 2228 measured. To reduce the braking effect on ice will determine the tire (size 165/80 R13) on a icy road at a speed of 40 km / h driven and then blocked. The slide after blocking until standstill is measured. These Property is expressed as the reciprocal of the measured distance, based on the corresponding reciprocal of mass No. 33, assumed to be 100 becomes. The higher the value, the better they are Braking properties on ice. The braking properties on Snow is tested in the same way. To wear to determine the amount rubbed off after a Running distance of 10,000 km measured. The value is as Index expressed in relation to the corresponding value with a tire from mass No. 33, which with 100 Is accepted. The larger the index, the better the abrasion resistance. The BR rubber used has has a high cis content and the SBR rubber Solution-polymerized SBR with a styrene content of 18%. The results are shown in Table 3. The crowds Nos. 26 to 32 are according to the invention, the others are Comparative examples.  

Table 3

Example D and Comparative Example D.

A rubber compound is made from 100 parts of the rubbers listed in Table 4, the amounts indicated on soot (N 339) and fibers or pulp made of leather reticulate or nylon fibers, 50 parts of naphthenic oil, 3 parts of zinc oxide, 2 parts stearic acid, 1 part antioxidant, 1 part Paraffin wax, 1.4 parts vulcanization accelerator and 2 parts of sulfur by mixing these ingredients for 4 minutes mixes in a Banbury mixer. Spike-less tires Size 165 SR13 are used in the usual way the mass obtained for the tread.

The rubber composition obtained is vulcanized in a mold at 160 ° C. for 20 minutes. The hardness of the mass is measured according to ASTM D 2228 at -15 ° C and 23 ° C and the difference between the two values is given as Δ hardness. The smaller the value, the better the low temperature properties. To determine the braking properties on ice, the tire (size 165 SR13) is driven on an icy road at a speed of 40 km / h and then blocked. The sliding distance of the tire after blocking to a standstill is measured. This property is given as the reciprocal of the measured distance, based on the corresponding reciprocal of mass No. 41, which is assumed to be 100. The larger the value, the better the braking properties on ice. The BR rubber used has a high cis content and the SBR rubber is solution-polymerized SBR with a styrene content of 10%. The results are shown in Table 4. The masses 35 to 40 are according to the invention, the others are comparative examples.

Claims (4)

1. rubber composition, characterized in that it contains a leather powder. 2. Rubber composition, characterized in that it is a Gelatin powder with an average particle size of contains less than 500 µm. 3. Tire, characterized by a tread a vulcanized rubber, the cells with a has an average axis ratio of up to 0.7 and was made from a rubber mass, which contains gelatin. 4. Spike-free winter tire, characterized by a Tread made from a rubber compound which contains a leather powder, wherein the leather powder has a reticular layer and / or Papillary layer with a hierarchical structure of fibers from collagen protein.