DE-102024210766-A1 - Rubber compound for aging protection

Abstract

The present invention relates to a rubber mixture in the form of a spray or coating for application to external surfaces of rubber products for aging protection, in particular to surfaces in grooves (1) of tires, which contains at least the following components: a) 100 phr ethylene propylene diene monomer rubber EPDM, b) 0 to 30 phr Carbon Black, c) 600 to 2000 phr paraffinic manufacturing oil. The invention further relates to a method for applying the mixture.

Inventors

• Christoph Vatterott
• Norbert Kendziorra
• Francesco Botti
• Muhamed Jesbeer Kallungal Abdul Jaleel

Assignees

• CONTINENTAL REIFEN DEUTSCHLAND GMBH

Dates

Publication Date

20260513

Application Date

20241108

Claims (11)

1. A rubber compound for application to the outer surfaces of unvulcanized or vulcanized rubber products for aging protection, in particular on surfaces in grooves (1) of tires, comprising at least the following components: a) over 95 phr, preferably over 98 phr, particularly preferably 100 phr ethylene propylene diene monomer rubber EPDM or ethylene propylene diene monomer rubber EPM, b) 0 to 30 phr carbon black, c) 600 to 2000 phr paraffinic manufacturing oil.
2. rubber compound according to Claim 1 , further containing up to 5 phr of vulcanizing chemicals, comprising sulfur and vulcanizing accelerators.
3. rubber compound according to Claim 1 , which does not contain sulfur, vulcanization accelerators or other vulcanizing chemicals.
4. Rubber compound according to one of the Claims 1 until 3 , which contains 600 to 1500 phr, preferably 600 to 1000 phr of paraffinic manufacturing oil.
5. Rubber compound according to one of the Claims 1 until 4 , which contains more than 0 phr carbon black, preferably more than 1 phr, more preferably more than 10 phr, particularly preferably more than 20 phr.
6. Rubber compound according to one of the Claims 1 until 5 , wherein the paraffinic manufacturing oil is preferably sulfur-free and/or highly refined and/or highly saturated.
7. Spray for application to the surfaces of rubber products, comprising the rubber compound according to one of the Claims 1 until 6 .
8. Use of the rubber compound according to one of the Claims 1 until 6 as an anti-aging agent for application to the surfaces of rubber products, especially to surfaces in the grooves of tires.
9. Rubber product, wherein at least one surface of the vulcanized material is coated with a rubber compound according to one of the Claims 1 until 6 It is coated to protect the surface from aging.
10. Vehicle tires, wherein the tire has a tread with grooves, wherein the rubber compound is according to one of the Claims 1 until 6 It is applied as a protective layer to the surfaces in the grooves.
11. Method for protecting the surface in the grooves of a vehicle tire from aging effects, wherein the rubber compound is formulated according to one of the Claims 1 until 6 The rubber mixture is provided, applied to the surfaces in the grooves by spraying or painting, and the vehicle tire with the applied rubber mixture is dried for at least 3 days at a temperature of 25 °C to 40 °C.

Description

The invention relates to a rubber compound for application to surfaces of rubber products for aging protection, in particular to surfaces in grooves of tires. The rubber composition largely determines the properties of a vehicle tire. Therefore, these rubber compounds are subject to high demands. In particular, the aging behavior plays a crucial role. Aging here refers specifically, but not exclusively, to the changes in the rubber material due to interactions with oxygen and especially ozone in the atmosphere. Aging leads, in particular, to an increasing porosity or stiffening of the rubber material, so that cracks increasingly appear under stress. In the current state of the art, there are basically two ways to protect a rubber compound from aging: The use of anti-aging agents in the rubber compound (see, for example: K. Berghus et al.: Handbook for the Rubber Industry, 2nd edition, Chapter 4 .) or the formation of a further age-resistant vulcanized layer on the surface of the vulcanizate to be protected, e.g. with a polymer with saturated carbon chains, such as from the KR 10208039 B1 or DE 19908122 A1 known. Both of the above-mentioned options have disadvantages. For example, the antioxidants used in current technology are inherently toxic. The necessary addition of antioxidants for antioxidant protection leads to significant environmental pollution. Therefore, legal limits regarding the use of known antioxidants such as 6PPD (N-(1,3-Dimethylbutyl)-N'-phenyl-p-phenylenediamine) or DTPD (N,N'-Di-(p-tolyl)-p-phenylenediamine, N,N'-(p-Phenylene)-ditoluidine) or other phenylenediamines (PD) are already under discussion. Applying additional coatings, in turn, involves difficulties and additional effort and costs in the processing and manufacturing of the tires. It is therefore at least one object of the present invention to provide a coating that can be applied easily and with little additional effort and provides sufficient protection against aging. The rubber compound according to the invention, for application to surfaces, can advantageously protect these surfaces from aging phenomena. The vulcanized or unvulcanized rubber product with the protected surface can therefore advantageously contain a reduced proportion of anti-aging agents. The invention encompasses all advantageous embodiments, which are reflected, inter alia, in the claims. In particular, the invention also encompasses embodiments resulting from the combination of different features, for example, components of the rubber compound or elements of the tire, with varying degrees of preference given to these features, such that a combination of a first feature designated as "preferred" or described within the framework of an advantageous embodiment with a further feature designated, for example, as "particularly preferred," is also encompassed by the invention. The following describes in more detail the components of the rubber compound according to the invention and the properties of a coating produced therefrom and of a coated unvulcanized or vulcanized rubber product. All information relating to the components of the rubber compound according to the invention, regardless of the degree of preference given to these features, also applies accordingly to the rubber product according to the invention, the vehicle tire according to the invention, and uses according to the invention. The unit phr (parts per hundred parts of rubber by weight) used in this document is the standard unit of measurement for compound formulations in the rubber industry. The dosage of the individual substances by weight is given in this document as 100 parts by weight of the total mass of all components in the... Mixture of existing rubbers with a molecular weight Mw according to GPC greater than 20000 g/mol. The specified value ranges always include the limit values. The rubber compound according to the invention serves for aging protection and is suitable for application to surfaces of rubber products for aging protection, in particular to surfaces in circumferential or transverse grooves of tires, especially the grooves in tire profiles, for aging protection of the surfaces in the grooves. The rubber compound according to the invention is suitable for being easily applied to surfaces of vulcanization products that are to be protected from aging and for curing or partially cross-linking there without vulcanization aids or chemicals, so that an aging protection layer is formed on the surface to be protected, which essentially comprises EPDM and optionally industrial carbon blacks or consists of EPDM and optionally added carbon black. The rubber compound according to the invention thus contains at least ethylene-propylene-diene rubber, or EPDM for short (ethylene, propylene, -diene monomers; M group). The proportion of EPDM is preferably more than 95 phr, more preferably more than 98 phr. The missing rubber components to reach 100 phr can be, in particular, diene rubbers co