Search

BR-112025016133-B1 - A mixture of cross-linkable rubber with sulfur, vulcanized rubber mixture, and vehicle tire.

BR112025016133B1BR 112025016133 B1BR112025016133 B1BR 112025016133B1BR-112025016133-B1

Abstract

A crosslinkable rubber mixture with sulfur, a vulcanized rubber mixture, and a vehicle tire. The present invention relates to a crosslinkable rubber mixture with sulfur, a vulcanized mixture thereof, and a vehicle tire. The sulfur-containing crosslinkable rubber mixture comprises at least the following constituents: - 50 to 100 phr of natural polyisoprene (NR), - 0 to 50 phr of at least one additional diene rubber, - 5 to 80 phr of at least one regenerated rubber produced using at least one regenerating agent selected from the group consisting of dithiophosphoryl polysulfides and silanes having a polysulfane group from a rubber mixture produced in an internal mixer, wherein the rubber mixture consists of at least 50% by weight of comminuted tread bands from heavy vehicle radial tires and/or bus radial tires, - 1 to 30 phr of at least one tack-enhancing resin, and - 50 to 100 phr of at least one filler.

Inventors

  • Christian Weber

Assignees

  • CONTINENTAL REIFEN DEUTSCHLAND GMBH

Dates

Publication Date
20260310
Application Date
20240118
Priority Date
20230222

Claims (15)

  1. 1. A crosslinkable rubber mixture with sulfur, characterized in that it comprises at least the following constituents: - 50 to 100 phr (parts by weight, based on 100 parts by weight of all rubbers present in the mixture) of natural polyisoprene (NR), - 0 to 50 phr of at least one additional diene rubber, - 5 to 80 phr of at least one regenerated rubber produced using at least one regenerating agent selected from the group consisting of dithiophosphoryl polysulfides and silanes having a polysulfane group of a rubber mixture produced in an internal mixer, wherein the rubber mixture consists of at least 50% by weight of comminuted tread bands from radial heavy vehicle tires and/or radial bus tires, - 1 to 30 phr of at least one tackiness-enhancing resin, and - 50 to 100 phr of at least one filler.
  2. 2. A mixture of crosslinkable rubber with sulfur, according to claim 1, characterized in that it contains: - 60 to 90 phr of natural polyisoprene, and - 10 to 40 phr of at least one additional diene rubber.
  3. 3. A mixture of crosslinkable rubber with sulfur, according to claim 2, characterized in that it contains, as at least one additional diene rubber, 10 to 40 phr of butadiene rubber (BR).
  4. 4. Mixture of crosslinkable rubber with sulfur, according to any one of claims 1 to 3, characterized in that it contains 5 to 40 phr of at least one regenerated rubber.
  5. 5. Mixture of crosslinkable rubber with sulfur, according to any one of claims 1 to 4, characterized in that the regenerating agent is selected from bis(O,O-2-ethylhexylthiophosphoryl) polysulfide and/or (bis(triethoxysilyl)propyltetrasulfane (TESPT)).
  6. 6. A mixture of crosslinkable rubber with sulfur, according to any one of claims 1 to 5, characterized in that the rubber mixture consists of at least 70% by weight of comminuted tread bands from radial tires of heavy vehicles and/or radial bus tires.
  7. 7. A mixture of crosslinkable rubber with sulfur, according to any one of claims 1 to 6, characterized in that it contains 2.5 to 10 phr of at least one tack-enhancing resin.
  8. 8. Mixture of crosslinkable rubber with sulfur, according to any one of claims 1 to 7, characterized in that the tack-enhancing resin(s) has/have a ring-ball softening point according to DIN 52011 of 50 to 160 °C, preferably 125 to 160 °C.
  9. 9. Mixture of crosslinkable rubber with sulfur, according to any one of claims 1 to 8, characterized in that the tack-enhancing resin(s) is/are selected from the group consisting of aliphatic hydrocarbon resins, phenolic resins, terpene resins, terpene-phenol resins, AMS resins, coumarone-indene resins and rosin resins.
  10. 10. Mixture of crosslinkable rubber with sulfur, according to claim 9, characterized in that the tack-enhancing resin(s) is/are selected from the group consisting of aliphatic hydrocarbon resins and phenolic resins.
  11. 11. Mixture of crosslinkable rubber with sulfur, according to any one of claims 1 to 10, characterized in that it contains, as filler, 5 to 45 phr, preferably 10 to 30 phr, of silica and 20 to 80 phr, preferably 40 to 65 phr, of carbon black.
  12. 12. Vulcanized, characterized in that it is obtained by vulcanization with sulfur of at least one rubber mixture, as defined in any one of claims 1 to 11.
  13. 13. Vehicle tire, characterized in that it includes at least one vulcanized component, as defined in claim 12.
  14. 14. Vehicle tire, according to claim 13, characterized in that it includes at least one vulcanized layer, as defined in claim 12, at least in the tread.
  15. 15. Vehicle tire, according to claim 14, characterized in that it includes at least one vulcanized section, as defined in claim 12, at the base of the tread.

Description

[001] The present invention relates to a mixture of crosslinkable rubber with sulfur, to the vulcanized mixture thereof and to a vehicle tire. [002] The composition of the tread rubber largely determines the driving characteristics of a vehicle tire, particularly those of a pneumatic vehicle tire. [003] Rubber compounds that find use, particularly in drive belts, hoses and belts that are subjected to severe mechanical stress, are substantially responsible for the stability and long service life of these rubber articles. Therefore, very high demands are placed on these rubber compounds for pneumatic vehicle tires, belts, drive belts and hoses. [004] There are trade-offs between most known tire properties, such as wet grip characteristics, braking characteristics, handling characteristics, rolling resistance, winter properties, abrasion characteristics and friction properties. [005] In particular, in the case of pneumatic vehicle tires, several attempts have been made to positively influence tire properties by varying polymer components, fillers, and other additives. In this context, it is necessary to consider that an improvement in one tire property often leads to a deterioration in another property. [006] In addition to the aforementioned objectives regarding the properties of the mixture and the vulcanizate, efforts are currently being made to reduce dependence on fossil raw materials and minimize greenhouse gas emissions. When designing more sustainable production processes, the recycling of old products that are no longer needed is becoming increasingly important. In many areas of technology, these “secondary” raw materials already allow for savings in the materials used in production, which improves the sustainability of production and the products thus produced. [007] For example, it is known from the prior art that rubber materials from old conveyor belts or used tires can be processed for use as added material in vulcanizable rubber mixtures, which can then undergo shaping in the course of producing tires or other rubber products and vulcanization to the desired rubber products. These “regenerated” rubber materials can, in principle, be produced in various ways. In particular, there are known materials prepared from the prior art in which, although still a rubber material in the strictest sense, i.e., cross-linked rubber, its plasticity is adjusted to that of unvulcanized rubber by means of suitable treatment methods, in particular employing thermochemical stress and chemicals. A process for producing regenerated rubber using special regenerating agents is described, for example, in document DE 10 2012 108 096 A1. Furthermore, there are regenerated rubbers in which there is at least partial devulcanization, that is, the breaking of chemical bonds in the rubber material, and in which the depolymerization of the previously cross-linked rubber material consequently contributes to an increase in plasticity. [008] The production of regenerated rubber from rubber materials employs various technologies and processes, for example, steam regeneration, mechanical regeneration, thermal regeneration, sound wave-based regeneration, radiation-based regeneration, chemical regeneration and combinations of these methods. [009] Since these processes for the production of regenerated rubber are being applied to structurally highly complex, disordered and inherently non-structurally describable starting materials and induce very different physicochemical changes depending on the processes and process parameters employed, the different regenerated rubber exhibit very different properties depending on the rubber materials originally used, whose chemical composition varies depending in particular on the nature of the recycled rubber products and the method used for devulcanization. [0010] When using different regenerated rubber in vulcanizable rubber blends, especially in the field of tire production with the prevailing profusion of very different requirement profiles in this sector, there is therefore often a compromise between adding the largest possible amount of regenerated rubber and at the same time obtaining the best possible performance characteristics, which preferably should not differ from those obtained for vulcanizable rubber blends from primary raw materials. [0011] When reclaimed rubber is used in mixtures containing a high proportion of natural rubber, it can, for example, lead to a deterioration in the crack resistance and heat buildup of the vulcanizates. [0012] The objective of the present invention is to provide a rubber mixture containing a proportion of regenerated rubber, whose vulcanizates exhibit high resistance to cracking and low heat buildup. [0013] This objective is achieved by a rubber mixture comprising at least the following constituents: - 50 to 100 phr (parts by weight, based on 100 parts by weight of all rubbers present in the mixture) of natural polyisoprene, - 0 to 50 phr of at least o