Vulcanizable rubber mixture, vulcanizable material and rubber product

Abstract

The present invention relates to a vulcanizable rubber compound comprising a) a diene rubber, b) silica, and c) a combined part by weight of a specific polyetheramine in the range of 0.1 to 10 phr, the vulcanizable rubber compound comprising a natural polyisoprene in the range of 25 to 100 phr by weight as the diene rubber, and the vulcanizable rubber compound comprises the one or more fillers in a combined part by weight of 55 phr or less.

Description

Field of the Invention

[0001] The present invention relates to a vulcanizable rubber compound, to a vulcanized rubber producible therefrom, and to a rubber product, in particular a pneumatic vehicle tire, comprising the vulcanized rubber. Background Art

[0002] The automotive industry has been facing fundamental challenges since the beginning of the 21st century and has been defined by numerous technological innovations. The increasing awareness of consumers regarding environmental issues such as emission characteristics and resource efficiency requires new mobility concepts. At the same time, the demand for improved vehicle characteristics and requirements related to driving safety are increasing. Meeting these challenges is not just the task of vehicle manufacturers. In practice, many of these issues are significantly influenced by the characteristics of vehicle tires, and thus the optimization of tire characteristics is an important area of innovation.

[0003] The main components for optimizing the characteristics of vehicle tires and other rubber products such as belts, conveyor belts, and hoses are the vulcanizable rubber compounds used for production and the rubber materials obtained therefrom by vulcanization. Many relevant characteristics of pneumatic vehicle tires, such as wet grip, rolling resistance, and wear behavior, are closely related to the composition of the rubber material of, for example, the tread. Therefore, much research work has focused on optimizing the characteristics of the rubber compositions used, which are often subject to very high requirements. At the same time, there are target conflicts regarding many characteristics of vehicle tires, which means that these characteristics cannot be optimized independently of each other and that the improvement of one parameter may lead to the deterioration of another parameter.

[0004] In recent decades, significant progress has been made in the field of composition development. The key innovations here are, for example, the at least partial replacement of carbon black fillers with silicon-containing compounds, in particular silica compounds such as fumed silica or precipitated silica.

[0005] EP 2725059 A1 discloses that the combination of polyetheramines and silica can result in advantageous rubber compounds that particularly have an improved performance level with respect to wear behavior and the target conflict between rolling resistance and wet grip. Furthermore, it has been found that improved processing characteristics can be obtained in the corresponding rubber compounds. Additional information regarding the technical background of polyetheramines is disclosed, for example, in WO 2013 / 092526 A1, US 2008 / 033082A1, and WO2016 / 030469 A1.

[0006] Although vulcanizable rubber compounds known from the prior art can achieve generally advantageous results in many respects, in many cases the corresponding compositions and the vulcanized rubbers producible therefrom are still considered to require improvement in terms of application-related properties, especially in order to meet the requirements for high-performance applications of modern pneumatic vehicle tires. Summary of the Invention

[0007] The main object of the present invention is to overcome or at least reduce the disadvantages of the prior art and to provide a vulcanizable rubber compound and a corresponding vulcanized rubber producible therefrom having an advantageous property profile.

[0008] In particular, the object of the present invention is to provide a vulcanizable rubber compound having excellent processing properties, and it is desirable to reduce the need for compounds potentially harmful to health and / or the environment (in particular guanidine accelerators).

[0009] Furthermore, the object of the present invention is to provide a vulcanizable rubber compound and a corresponding vulcanized rubber producible therefrom having excellent rolling properties, in particular favorable rolling resistance.

[0010] Furthermore, the object of the present invention is to provide a vulcanizable rubber compound and a corresponding vulcanized rubber producible therefrom, which vulcanized rubbers have excellent mechanical properties, especially in terms of improved wear properties and favorable durability, and especially also in terms of improved tear properties on rough roads.

[0011] In particular, the object of the present invention is to optimally resolve the existing objective conflict between processing properties, mechanical properties and rolling properties.

[0012] In this regard, another object of the present invention is that the vulcanizable rubber compound and the vulcanized rubber to be provided should be producible as far as possible using production methods and materials already used in the rubber processing field today.

[0013] Another object of the present invention is to provide corresponding rubber products, in particular pneumatic vehicle tires having favorable properties, comprising the vulcanized rubber to be provided.

[0014] The inventors of the present invention have now surprisingly found that the above objects can be achieved when, as defined in the claims, the vulcanizable rubber compound contains not only a diene rubber and silica, but also a specific polyetheramine in a specific weight portion, a maximum content of silica, and natural rubber is used as the diene rubber.

[0015] Therefore, the above objects are achieved by the subject matter of the present invention as defined in the claims. Preferred embodiments of the present invention will become apparent from the dependent claims and the following discussion.

[0016] In a particularly preferred embodiment, the features of the embodiments hereinafter referred to as preferred are combined with the features of other embodiments hereinafter referred to as preferred. Accordingly, combinations of two or more of the embodiments hereinafter referred to as particularly preferred embodiments are the most particularly preferred. Embodiments in which the features of one embodiment hereinafter referred to as preferred to some extent are combined with one or more further features of other embodiments hereinafter referred to as preferred to some extent are likewise preferred. The features of the preferred vulcanizable rubber compounds, rubber products and uses will become apparent from the features of the preferred vulcanizable rubber blends.

[0017] In the following text, where specific amounts / parts of the blend components (such as diene rubbers or polyetheramines) are disclosed not only for the blend components, but also preferred embodiments of the blend components are disclosed, the text in particular also discloses the specific amounts / parts of the blend components of these preferred embodiments. In addition, it is disclosed that, in the case of the respective specific total amounts / total parts of the blend components, at least some of these blend components can be of the preferred embodiments, and in particular it is also disclosed that the blend components of the preferred embodiments can in turn be present in these specific amounts / parts within these specific total amounts or total parts.

[0018] The present invention relates to a vulcanizable rubber blend comprising:

[0019] a) one or more diene rubbers,

[0020] b) one or more fillers selected from the group consisting of silica, and

[0021] c) one or more polyetheramines in a combined weight part range of from 0.1 to 10 phr,

[0022] These polyetheramines are selected from the group consisting of polyetheramines having the formula I):

[0023] I) R 1 R 2 N-(R 5 ) m -X-R 6 -NR 3 R 4 ,

[0024] wherein R 1 、R 2 、R 3 and R 4 are each independently hydrogen or a branched or unbranched hydrocarbon group having 1 to 10 carbon atoms, where m is 0 or 1, and wherein R 5 and R 6 are each independently a branched or unbranched hydrocarbon chain having 1 to 10 carbon atoms,

[0025] wherein X is a polyether chain having the formula II):

[0026] II)-(CHR 7i -CHR 8i -O) x -

[0027] where x ranges from 2 to 30, and wherein R in each monomer unit i 7i and R 8i are each independently of one another and independently of the other monomer units in the polyether chain hydrogen or a hydrocarbon group having 1 or 2 carbon atoms.

[0028] The vulcanizable rubber blend contains natural polyisoprene in an amount in the range of 25 to 100 phr by weight as the diene rubber, and

[0029] the vulcanizable rubber blend contains a combined amount of 55 phr or less of the one or more fillers.

[0030] The vulcanizable rubber blend itself, its typical components, and also the customary production methods for obtaining the corresponding vulcanizable rubber blend (in particular by mixing these components) are well known to those skilled in the art of rubber processing.

[0031] According to standard practice, the components of the vulcanizable rubber blend as defined above are each used in the form of "one or more". As is customary in the industry, the expression "one or more" refers to the chemical nature of the corresponding compound, not to its molar amount. For example, the vulcanizable rubber blend can contain only SBR as the diene rubber, which would mean that the vulcanizable rubber blend contains a large amount of the corresponding molecules.

[0032] In cases where the following text indicates parts by weight, as is customary in the industry, they are in many cases indicated in the form of the combined parts by weight of the one or more components, whereby the added parts by weight of the components thus formed meet the corresponding standards.

[0033] The measure phr (parts per hundred parts of rubber by weight) used herein is the customary representation of the amounts used in the formulation of rubber compounds in the rubber industry and indicates the parts by weight of the components in a rubber compound based on the weight of the high molecular weight rubber (weight average molar mass Mw determined by GPC greater than 60 000 g / mol) present in the rubber compound, where the combined parts by weight of said high molecular weight rubber in the rubber compound corresponds to 100 phr. Similarly, the measure phf (parts per hundred parts of filler by weight) is the customary representation of the amounts used in the formulation of rubber compounds, in particular for coupling agents for fillers, based on the weight of the filler present in the rubber compound. In the context of the present invention, the measure phf is based only on the silica present in the vulcanizable rubber compound, and the combined parts by weight of this silica corresponds to 100 phf, which means that other fillers that may be present (such as carbon black) are not included in the calculation of phf.

[0034] The vulcanizable rubber compound according to the invention comprises at least one diene rubber. As will be understood by those skilled in the art, a diene rubber is a rubber obtained by the (co)polymerization of a diene and / or a cycloolefin and thus having C═C double bonds in the main chain or in a side group.

[0035] According to the invention, the vulcanizable rubber compound comprises natural rubber as the diene rubber. Natural rubber is well known to those skilled in the art in the field of tire production and is commercially available. Natural rubber is natural polyisoprene, in particular cis-1,4-polyisoprene, where the cis-1,4 content in natural rubber is greater than 99% by weight.

[0036] An advantage of the vulcanizable rubber blend according to the invention can be considered to be that, in addition to natural rubber, further diene rubbers can be present and there is a high degree of flexibility in their selection and thus, in principle, all combinations of diene rubbers customary in industry can be used. In this regard, according to the inventors, it is preferred for the vulcanizable rubber blend according to the invention that the one or more diene rubbers are selected from the group consisting of natural polyisoprene, synthetic polyisoprene, epoxidized polyisoprene, butadiene rubber, solution-polymerized styrene-butadiene rubber, emulsion-polymerized styrene-butadiene rubber, polynorbornene, ethylene-propylene-diene rubber, nitrile rubber, acrylate rubber, styrene-isoprene-butadiene terpolymer, butyl rubber and halogenated butyl rubber, wherein the one or more diene rubbers are preferably selected from the group consisting of natural polyisoprene (NR), synthetic polyisoprene (IR), butadiene rubber (BR), solution-polymerized styrene-butadiene rubber (SSBR) and emulsion-polymerized styrene-butadiene rubber (ESBR), and wherein the one or more diene rubbers are particularly preferably selected from the group consisting of natural polyisoprene and butadiene rubber. In this regard, additionally or alternatively, it is also preferred for the vulcanizable rubber blend according to the invention that at least one of these diene rubbers is a terminally modified and / or chain-modified diene rubber, preferably a terminally modified diene rubber. The modification can be one or more functional groups selected from the group consisting of hydroxyl, ethoxy, epoxy, siloxane groups, amino, aminosiloxane groups, carboxyl, phthalocyanine groups and silane-sulfide groups.

[0037] Regarding the content of natural polyisoprene, it is preferred for the vulcanizable rubber blend according to the invention that the vulcanizable rubber blend contains natural polyisoprene as a diene rubber in an amount of 50 phr or more, preferably 60 phr or more, and particularly preferably 65 phr or more by weight parts. Additionally or alternatively, it is preferred for the vulcanizable rubber blend according to the invention that the vulcanizable rubber blend contains natural polyisoprene as a diene rubber in an amount of 90 phr or less, and preferably 80 phr or less by weight parts.

[0038] It has been found that BR and IR, in particular for combination with natural polyisoprene, are suitable diene rubbers for obtaining a vulcanizable rubber blend that can be converted by vulcanization into a particularly effective vulcanized rubber.

[0039] Accordingly, a preferred vulcanizable rubber compound according to the present invention is one in which the vulcanizable rubber compound contains a butadiene rubber as a diene rubber, preferably in an amount of from 1 to 75 phr by weight, particularly preferably in the range of from 5 to 55 phr, and most particularly preferably in the range of from 10 to 35 phr. The butadiene rubber can be, for example, a so-called high-cis or low-cis butadiene rubber, and the high-cis butadiene rubber refers to polybutadiene having a cis content of 90% or more based on mass.

[0040] Furthermore, additionally or alternatively, a preferred vulcanizable rubber compound according to the present invention is one in which the vulcanizable rubber compound contains synthetic polyisoprene as a diene rubber, preferably in a combined amount of from 1 to 75 phr by weight, particularly preferably in the range of from 5 to 55 phr, and most particularly preferably in the range of from 10 to 35 phr. The synthetic polyisoprene can be cis-1,4-polyisoprene or 3,4-polyisoprene. However, it is preferred to use cis-1,4-polyisoprene.

[0041] Additionally or alternatively, a preferred vulcanizable rubber compound according to the present invention is one in which the one or more diene rubbers have a weight-average molar mass Mw measured by GPC in the range of from 150,000 to 5,000,000 g / mol, preferably in the range of from 250,000 to 2,500,000, and particularly preferably in the range of from 300,000 to 1,500,000. In the context of the present invention, the determination of the number-average or weight-average molar mass is carried out by gel permeation chromatography (GPC using tetrahydrofuran as the eluent and polystyrene standards; size exclusion chromatography) in accordance with DIN 55672-1:2016-03.

[0042] The vulcanizable rubber compound according to the present invention contains one or more fillers selected from the group consisting of silica. In the context of the present invention, in the original German text of the present application, the industrially customary German term [silicic acid] is used, and related compounds are sometimes also referred to as "Silika" according to the English term "silica". For those skilled in the rubber processing industry, this historically inherited German term refers to amorphous (i.e., non-crystalline) silica, particularly so-called fumed silica and precipitated silica. In other words, the vulcanizable rubber compound according to the present invention is a rubber compound containing one or more fillers selected from the group consisting of fumed silica and precipitated silica, particularly preferably precipitated silica.

[0043] Fundamentally preferred is a vulcanizable rubber compound according to the present invention, wherein the one or more fillers have a BET surface area in the range of from 35 to 400 m2 in the range of / g, preferably in the range of 35 to 350 m 2 / g, particularly preferably in the range of 85 to 320 m 2 / g, and most particularly preferably in the range of 120 to 235 m 2 / g of the nitrogen surface area (BET surface area). Additionally or alternatively, preferably the curable rubber blend according to the invention, wherein the one or more fillers have a BET surface area in the range of 30 to 400 m 2 / g, preferably in the range of 30 to 330 m 2 / g, particularly preferably in the range of 80 to 300 m 2 / g, and most particularly preferably in the range of 115 to 200 m 2 / g of the CTAB surface area.

[0044] Regarding the amount of filler that can be used, the inventors have found that when combined with natural rubber and polyetheramine, if a favorable curable rubber blend is to be obtained, there is an upper limit that should not be exceeded for the parts by weight of silica. Thus, the curable rubber blend is included in a combined parts by weight of 55 phr or less.

[0045] The inventors have found that a favorable property profile can particularly be achieved in the case of a relatively low parts by weight of silica. Fundamentally preferably, the curable rubber blend according to the invention, wherein the curable rubber blend contains the one or more fillers in a combined parts by weight of 50 phr or less, preferably 40 phr or less, and particularly preferably 35 phr or less.

[0046] Those skilled in the art will understand that those skilled in the art will not wish to select too low a parts by weight of silica, due to the fundamentally positive properties of silica, especially in tread compounds. Thus, additionally or alternatively, preferably the curable rubber blend according to the invention, wherein the curable rubber blend contains the one or more fillers in a combined parts by weight in the range of 5 to 55 phr, preferably in the range of 10 to 50 phr, particularly preferably in the range of 15 to 45 phr, and most particularly preferably in the range of 20 to 40 phr.

[0047] The experiments of the inventors have shown that a particular parts by weight of silica in combination with a particular parts by weight of natural polyisoprene results in particularly favorable properties of the vulcanized rubber. Preferably, the curable rubber blend according to the invention,

[0048] i) wherein the curable rubber compound comprises the one or more fillers in a combined amount by weight in the range of 40 to 50 phr, and wherein the curable rubber compound comprises natural polyisoprene in an amount by weight in the range of 60 to 80 phr,

[0049] or

[0050] ii) wherein the curable rubber compound comprises the one or more fillers in a combined amount by weight in the range of 20 to 40 phr, and wherein the curable rubber compound comprises natural polyisoprene in an amount by weight in the range of 90 to 100 phr.

[0051] Additionally or alternatively, particularly preferably, the curable rubber compound according to the invention, wherein the combined amount by weight of the natural polyisoprene and the one or more fillers is in the range of 30 to 150 phr, preferably in the range of 60 to 140 phr, and particularly preferably in the range of 90 to 135 phr.

[0052] In addition to the silica to be used according to the invention, additional fillers may additionally be present, thereby allowing for a specific adjustment of the properties of the curable rubber compound. Preferably, the curable rubber compound according to the invention, wherein the curable rubber compound comprises one or more additional fillers selected from the group consisting of carbon black, aluminum hydroxide, titanium dioxide, magnesium oxide, and layered silicates, and the combined amount by weight of these additional fillers is preferably in the range of 0.1 to 100 phr, and particularly preferably in the range of 0.5 to 50 phr.

[0053] According to the inventors, particularly advantageous properties become particularly evident in combination with carbon black as an additional filler. Preferably, the curable rubber compound according to the invention, wherein the curable rubber mixture comprises carbon black, preferably in a combined amount by weight of 1 phr or more and preferably 2 phr or more.

[0054] Particularly preferably, the contents of silica and carbon black are matched to each other. For this purpose, preferably, the curable rubber compound containing carbon black according to the invention, wherein the combined amount by weight of all the fillers (the fillers to be used according to the invention and these additional fillers) in the curable rubber compound is in the range of 30 to 80 phr, and preferably in the range of 40 to 70 phr. In this regard, particularly preferably, the curable rubber compound, wherein based on the total mass of all the fillers, the combined mass ratio of silica is in the range of 30% to 75%, preferably in the range of 35% to 70%.

[0055] The carbon black used is preferably a carbon black having an iodine adsorption value according to ASTM D 1510 of 30 to 250 g / kg, preferably 30 to 180 g / kg, and particularly preferably 40 to 130 g / kg, and a DBP value according to ASTM D 2414 of 30 to 200 ml / 100 g, preferably 70 to 200 ml / 100 g, and particularly preferably 90 to 200 ml / 100 g.

[0056] The vulcanizable rubber compound according to the invention comprises at least one polyetheramine having a specific structure. Polyetheramines are well known to those skilled in the art. They are polyether polyols in which the terminal hydroxyl groups have been converted to amino groups in an amination reaction, thus obtaining polyamines. In the case of amination of particularly preferred straight-chain (i.e., non-branched) polyether diols, the polyetheramines are accordingly diamines of polyalkylene diols. The base polyether diols are preferably prepared from alkylene oxides (such as butylene oxide, ethylene oxide or propylene oxide). Polyetheramines are commercially available, in particular from Huntsman, for example under the trade names Jeffamine D-230, ED-600, ED-900 or EDR-148.

[0057] The polyetheramine to be used according to the invention is selected from the group consisting of polyetheramines having the formula I):

[0058] I) R 1 R 2 N-(R 5 ) m -X-R 6 -NR 3 R 4 ,

[0059] wherein R 1 , R 2 , R 3 and R 4 are each independently hydrogen or a branched or unbranched hydrocarbon group having 1 to 10 carbon atoms, where m is 0 or 1, wherein R 5 and R 6 are each independently a branched or unbranched hydrocarbon chain having 1 to 10 carbon atoms,

[0060] wherein X is a polyether chain having the formula II):

[0061] II)-(CHR 7i -CHR 8i -O) x -

[0062] where x is in the range from 2 to 30, where R 7i and R 8iIn each case independently of one another and independently of the other monomer units in the polyether chain, it is hydrogen or a hydrocarbon group having 1 or 2 carbon atoms.

[0063] R 1 , R 2 , R 3 and R 4 The organic groups define the groups of the amino groups of the diamine and are in particular produced by the substances used for the amination reaction. As understood by those skilled in the art, these groups are in principle independent of one another, which means that, for example, R 1 can be hydrogen, even if R 2 is a hydrocarbon group. In this regard, a vulcanizable rubber compound according to the invention is preferred, wherein R 1 , R 2 , R 3 and R 4 are each independently hydrogen or a branched or unbranched, preferably unbranched, hydrocarbon group having 1 to 5 carbon atoms, preferably having 2 to 5 carbon atoms. Particularly preferred is a vulcanizable rubber compound according to the invention, wherein at least one of the R 1 and R 2 groups and / or one of the R 3 and R 4 groups is hydrogen. Most particularly preferred is a vulcanizable rubber compound according to the invention, wherein the R 1 and R 3 groups and / or the R 2 and R 4 groups are the same. Particularly preferred is a vulcanizable rubber compound according to the invention, wherein R 1 , R 2 , R 3 and R 4 groups are hydrogen.

[0064] One of these amino groups can be bonded directly (m = 0) or via a hydrocarbon chain (m = 1) to the polyether chain X. In the preferred polyetheramines, due to the preparation from alkylene oxides, one of these amino groups is bonded directly to the polyether chain X (m = 0), while the other amino group is bonded via an R 6 hydrocarbon chain, which R 6 hydrocarbon chain will ultimately be the last building block of the polyether chain; however, this last building block no longer has an oxygen atom due to amination and can therefore no longer be regarded as part of the polyether chain X. Thus, first preferred is a vulcanizable rubber compound according to the invention, wherein R 5 and R 6 are each independently a branched or unbranched hydrocarbon chain having 1 to 5 carbon atoms, preferably having 2 or 3 carbon atoms. In this regard, particularly preferred is a vulcanizable rubber compound according to the invention, wherein m = 0, wherein R6 Preferably a branched or unbranched hydrocarbon chain having 2 or 3 carbon atoms, particularly preferably a branched or unbranched hydrocarbon chain having 3 carbon atoms.

[0065] The polyether chain X comprises x repeating units. Preferably, the vulcanizable rubber blend according to the invention, wherein x is in the range of 2 to 15.

[0066] In each unit of the polyether chain X, i.e., in the different monomer units identified herein by the sequential number i numbered correspondingly from i = 1 to i = x, R 7i and R 8i are substantially independent of each other. Specifically, not only are R 7i and R 8i in each monomer unit substantially independent of each other, but all R 7i and all R 8i in the polyether chain are substantially independent of each other. Due to the fundamental advantage of alkylene oxides having a relatively short chain length, preferably the vulcanizable rubber blend according to the invention, wherein R 7i and R 8i in each monomer unit i are each independently and independently of the other monomer units in the polyether chain hydrogen or methyl. Particularly preferably, in the vulcanizable rubber blend according to the invention, wherein, in each monomer unit i, at least one of R 7i and R 8i groups is hydrogen in each case.

[0067] In this regard, those skilled in the art will understand that the nature of the R 7i and R 8i groups depends in particular on the chemical nature of the compounds used in the preparation of the polyetheramine (especially the alkylene oxides used), and in particular when different alkylene oxides are mixed together in the preparation of the polyetheramine, more complex polyetheramines can be obtained.

[0068] According to the inventors, preferably the vulcanizable rubber blend according to the invention, wherein the polyether chain comprises one or more first monomer units i1 having the formula IV):

[0069] IV) - (CHR 7i -CH2-O)-,

[0070] wherein R 7i is preferably the same for all first monomer units i1, wherein R 7i is particularly preferably methyl for all first monomer units i1, and / or

[0071] wherein the polyether chain comprises one or more second monomer units i2 having the formula V):

[0072] V)-(CH2-CH2-O)-, and / or

[0073] wherein the polyether chain comprises one or more third monomer units i3 having the formula VI):

[0074] VI)-(CH2-CHR 8i -O)-,

[0075] wherein R 8i is preferably the same for all third monomer units i3, wherein R 8i is particularly preferably methyl for all third monomer units i3, and the polyether chain preferably consists of these monomer units.

[0076] For these monomer units, a curable rubber blend according to the invention is fundamentally preferred, wherein the number x1 of the first monomer units i1 in the polyether chain is in the range from 1 to 7, preferably in the range from 2 to 6, and particularly preferably in the range from 2 to 5, and / or wherein the number x2 of the second monomer units i2 in the polyether chain is in the range from 1 to 15, preferably in the range from 2 to 12, and particularly preferably in the range from 3 to 10, and / or wherein the number x3 of the third monomer units i3 in the polyether chain is in the range from 1 to 7, preferably in the range from 2 to 6, and particularly preferably in the range from 2 to 5. In this regard, a curable rubber blend according to the invention is particularly preferred, wherein the combined number x 1 / 3 of the first monomer units i1 and the third monomer units i3 in the polyether chain is in the range from 2 to 10, preferably in the range from 3 to 7.

[0077] In this regard, first and most particularly preferred is a curable rubber blend according to the invention, wherein the polyether chain consists of the first monomer units i1 to a preferably greater than 50% extent, particularly preferably to a greater than 75% extent, and very particularly preferably substantially entirely, and the number x1 of the first monomer units i1 in the polyether chain is in the range from 1 to 5, and preferably in the range from 2 to 4. A corresponding polyetheramine is commercially available, for example, under the trade name Jeffamine D-230, wherein x1 is about 2.5.

[0078] Additionally or alternatively, a curable rubber blend according to the invention having a mixed polyether chain is also particularly preferred, i.e., wherein the polyether chain comprises two or more, preferably three or more monomer units selected from the group consisting of the first monomer units i1, the second monomer units i2, and the third monomer units i3, and the polyether chain preferably consists of these monomer units. Relevant for most applications is a curable rubber blend according to the invention, wherein at least some and preferably all of the two or more monomer units are randomly distributed in the polyether chain.

[0079] For the mixed polyether chains, first and most particularly preferred is the vulcanizable rubber blend according to the invention, wherein the combined number x of the first monomer unit i1 and the third monomer unit i3 in the polyether chain 1 / 3 is in the range from 2 to 5, and wherein the number x2 of the second monomer unit i2 in the polyether chain is in the range from 7 to 12. A corresponding polyetheramine is commercially available, for example, under the trade name Jeffamine ED-600, wherein x2 is about 9 and x 1 / 3 is about 3.6.

[0080] For the mixed polyether chains, additionally or alternatively, also most particularly preferred is the vulcanizable rubber blend according to the invention, wherein the combined number x of the first monomer unit i1 and the third monomer unit i3 in the polyether chain 1 / 3 is in the range from 4 to 8, and wherein the number x2 of the second monomer unit i2 in the polyether chain is in the range from 10 to 15. A corresponding polyetheramine is commercially available, for example, under the trade name Jeffamine ED-900, wherein x2 is about 12.5 and x 1 / 3 is about 6.

[0081] The inventors particularly consider that the use of such polyetheramines, typified by the commercial products Jeffamine D-230 and ED-600, is preferred for achieving the object of the invention.

[0082] Thus, particularly preferred is the vulcanizable rubber blend according to the invention, wherein the one or more polyetheramines are selected from the group consisting of:

[0083] - a polyetheramine having the formula VII):

[0084] VII) H2N-(CH(CH3)-CH2-O) x1 -CH2CH(CH3)-NH2,

[0085] wherein x1 is in the range from 2 to 6, preferably in the range from 2 to 5, particularly preferably in the range from 2 to 4, and most particularly preferably in the range from 2 to 3, and

[0086] - a polyetheramine having the formula VIII):

[0087] VIII) H2N-X-CH2CH(CH3)-NH2,

[0088] wherein X is a polyether chain composed of two or more monomer units selected from the group consisting of

[0089] a first monomer unit i having the formula IV b ) 1b :

[0090] IV b )-(CH(CH3)-CH2-O)-,

[0091] having a second monomer unit i of formula V b ) 2b :

[0092] V b )-(CH2-CH2-O)-, and

[0093] having a third monomer unit i of formula VI b ) 3b :

[0094] VI b )-(CH2-CH(CH3)-O)-,

[0095] wherein the combined number x of the first monomer unit i 1b and the third monomer unit i 3b in the polyether chain is in the range of 2 to 5, and the number x of the second monomer unit i 1b / 3b in the polyether chain is in the range of 8 to 10. 2b 2b

[0096] Based on the preparation or preparability of the polyetheramine, it is also highly preferred to use a vulcanizable rubber blend according to the invention, wherein the one or more polyetheramines are preparable by polymerization of an alkylene oxide followed by amination, the alkylene oxide preferably being selected from the group consisting of butylene oxide, ethylene oxide, propylene oxide and mixtures of these compounds (preferably propylene oxide). Additionally or alternatively, it is also particularly preferred to use a vulcanizable rubber blend according to the invention, wherein the one or more polyetheramines are saturated compounds.

[0097] The polyetheramines preferably used are compounds having a relatively short chain length. Specifically, it is particularly preferred to use a vulcanizable rubber blend according to the invention, wherein the one or more polyetheramines have a weight-average molar mass in the range of 100 to 800 g / mol, preferably in the range of 130 to 650 g / mol, and particularly preferably in the range of 190 to 400 g / mol.

[0098] ​​In order to further optimize the properties of the vulcanizable rubber blend according to the invention and the vulcanized rubber producible therefrom, different polyetheramines can be combined. Among them, in particular, a combination of polyetheramines, for example, as achieved by combining the commercial products Jeffamine D-230 and ED-600, is considered advantageous by the inventors. Therefore, a preferred vulcanizable rubber blend according to the invention is one in which the vulcanizable rubber blend contains two or more different polyetheramines.

[0099] Regardless of the exact chemical nature of the polyetheramine, the inventors have successfully determined particularly advantageous parts by weight of these components, by which the above object can be particularly well achieved. Specifically, a preferred vulcanizable rubber blend according to the invention is one in which the vulcanizable rubber blend contains the one or more polyetheramines in a combined parts by weight in the range of 0.2 to 8 phr, and preferably in the range of 0.4 to 6 phr.

[0100] In addition to the diene rubber, filler, and polyetheramine, other typical components can also be used in the vulcanizable rubber blend according to the invention, for example, for influencing the physicochemical properties (such as processing and vulcanization properties) of the vulcanizable rubber blend or for optimizing the mechanical properties of the vulcanized rubber producible therefrom.

[0101] In this regard, first preferred is a vulcanizable rubber blend according to the invention, in which the vulcanizable rubber blend contains one or more additionally added substances, which are preferably selected from the group consisting of reinforcing resins, coupling agents, and plasticizers. The vulcanizable rubber blend preferably contains these additionally added substances in a combined parts by weight in the range of 10 to 100 phr, preferably in the range of 20 to 80 phr, and particularly preferably in the range of 30 to 60 phr.

[0102] Examples that may be mentioned are vulcanizable rubber blends according to the invention, wherein the reinforcing resin is selected from the group consisting of resorcinol-formaldehyde resins (in particular resorcinol-hexamethoxymethylmelamine resin (HMMM) or resorcinol-hexamethylenetetramine resin (HEXA)), and modified phenolic resins. A person skilled in the art of rubber processing can easily distinguish the resin from the diene rubber, and in practice, this is achieved in particular by the average molar mass. In this regard, examples that may be mentioned are vulcanizable rubber blends according to the invention, wherein the one or more additional resins have a weight-average molar mass Mw measured by GPC in the range of 200 to 50,000 g / mol, preferably in the range of 400 to 40,000 g / mol, particularly preferably in the range of 600 to 30,000 g / mol, and most particularly preferably in the range of 800 to 20,000 g / mol.

[0103] Examples that may also be mentioned are vulcanizable rubber blends according to the invention, wherein the coupling agent is selected from the group consisting of 3-mercaptopropyltriethoxysilane, 3-thiocyanatopropyltrimethoxysilane, and 3,3'-bis(triethoxysilylpropyl) polysulfides having 2 to 8 sulfur atoms, and the vulcanizable rubber blend preferably contains the coupling agent in a combined weight part range of 0.2 to 30 phr, and preferably in the range of 1 to 15 phr.

[0104] Furthermore, examples that may be mentioned are vulcanizable rubber blends according to the invention, wherein the plasticizer is selected from the group consisting of mineral oil, synthetic plasticizer, fatty acid, fatty acid derivative, plasticizer resin, ointment, glyceride, terpene, biomass-to-liquid oil (BTL oil), and rubber-to-liquid oil (RTL oil), and the vulcanizable rubber blend preferably contains the plasticizer in a combined weight part range of 1 to 100 phr, preferably in the range of 10 to 80 phr, and particularly preferably in the range of 20 to 60 phr.

[0105] Additionally or alternatively, it is preferred that the vulcanizable rubber blend according to the present invention, wherein the vulcanizable rubber blend comprises one or more additional additives, which additional additives are preferably selected from the group consisting of: methylene donors, anti-aging agents such as N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (6PPD), N,N'-diphenyl-p-phenylenediamine (DPPD), N,N'-dimethylxyl-p-phenylenediamine (DTPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), 2,2,4-trimethyl-1,2-dihydroquinoline (TMQ), activators such as zinc oxide and fatty acids, waxes, mastication aids such as 2,2'-dibenzamidodiphenyldisulfide (DBD), and processing aids. It is preferred that the vulcanizable rubber blend according to the present invention, wherein the vulcanizable rubber blend comprises these additional additives in a combined weight fraction in the range of 0.1 to 20 phr, preferably in the range of 0.5 to 15 phr, and particularly preferably in the range of 1 to 10 phr.

[0106] Regarding the vulcanization behavior, it is preferred that the vulcanizable rubber blend according to the present invention, wherein the vulcanizable rubber blend comprises 0.5 to 8.0 phr, preferably 0.8 to 6 phr, and particularly preferably 1 to 4 phr of sulfur. In this regard, additionally or alternatively, it is also preferred that the vulcanizable rubber blend according to the present invention, wherein the vulcanizable rubber blend comprises additional vulcanization components, which additional vulcanization components are selected from the group consisting of crosslinking agents, vulcanization retarders, and vulcanization accelerators (such as thiazole accelerators, mercapto accelerators, sulfenamide accelerators, thiocarbamate accelerators, thiuram accelerators, thiophosphate accelerators, thiourea accelerators, xanthate accelerators, or guanidine accelerators).

[0107] It is particularly preferred to dispense with the use of guanidine accelerators (especially diphenylguanidine). Thus, it is preferred that the vulcanizable rubber blend according to the present invention, wherein the vulcanizable rubber blend comprises 2 phr or less, preferably 1 phr or less, particularly preferably 0.5 phr or less, and most particularly preferably substantially 0 phr of guanidine accelerators, especially diphenylguanidine.

[0108] From the vulcanizable rubber blend according to the present invention, vulcanized rubber and rubber products can be produced in a conventional manner. The corresponding method for producing vulcanized rubber or rubber products, in addition to producing the vulcanizable rubber blend according to the present invention, further includes, for example, the following steps:

[0109] x) The vulcanizable rubber compound according to the invention, which is preferably part of a rubber blank and particularly preferably part of an unvulcanized vehicle tire blank, is vulcanized to obtain vulcanized rubber which is preferably part of a rubber product and preferably part of an inflated vehicle tire.

[0110] Here, the vulcanizable rubber compound according to the invention is vulcanized, for example, by conventional methods in the tire industry, such as by sulfur-based crosslinking.

[0111] Accordingly, the invention also relates to a vulcanized rubber which can be produced or is produced by vulcanizing the vulcanizable rubber compound according to the invention. In this regard, preference is given to the vulcanized rubber according to the invention, wherein the vulcanized rubber can be produced by vulcanization at a temperature in the range from 130 °C to 200 °C, preferably in the range from 150 °C to 180 °C.

[0112] Accordingly, the invention also relates to a rubber product which comprises the vulcanized rubber according to the invention. Examples which may be mentioned are rubber products according to the invention, wherein the rubber product is selected from the group consisting of shoe soles, conveyor belts, hoses, conveyor belts, and belts. However, for substantially all cases, preference is given to rubber products according to the invention, wherein the rubber product is a vehicle tire, preferably an inflated vehicle tire, which preferably comprises the vulcanized rubber according to the invention in the tread.

[0113] Finally, the use of the vulcanizable rubber compound according to the invention and / or the vulcanized rubber according to the invention in the production of rubber products, in particular vehicle tires, is also disclosed. Detailed Description

[0114] The invention and preferred embodiments of the invention will be explained and described in more detail below with reference to experiments.

[0115] A. Production of the vulcanizable rubber compound:

[0116] The vulcanizable rubber compound is produced in a laboratory tangential mixer by conventional methods in the rubber industry under conventional conditions in three stages, which method comprises first preparing a base compound containing all the components except the vulcanization system (sulfur and substances affecting vulcanization) in one or more mixing stages, and subsequently adding the vulcanization system thereto to obtain the final compound.

[0117] The substances used in this regard are listed in Table 1.

[0118] Table 1 - Substances Used

[0119]

[0120]

[0121] Each of these vulcanizable rubber compounds was vulcanized at 160 °C to 170 °C under pressure for t 95 -t 100 (measured using a moving die rheometer according to ASTM D 5289-19 / ISO 6502) and then test specimens were produced, and the material properties typical of the rubber industry were determined for the test specimens so produced using the test methods specified in Part B.

[0122] B. Determination of the physicochemical properties of vulcanized rubber:

[0123] The following physicochemical properties were determined for the vulcanizable rubber compounds and the vulcanized rubber produced therefrom using the determination methods listed in Table 2:

[0124] Table 2 - Determination methods used

[0125]

[0126]

[0127] C. Test series:

[0128] Ten vulcanizable rubber compounds were produced, the composition of which is detailed in Table 3.

[0129] Table 3 - Vulcanizable rubber compounds (all data in phr)

[0130] Ingredient V1 E1 V2 E2 V3 E3 V4 E4 V5 V6 NR 100 100 70 70 30 30 100 100 100 100 BR 0 0 30 30 70 70 0 0 0 0 Filler 1 46 46 46 46 46 46 30 30 60 60 Filler 2 3 3 3 3 3 3 3 3 3 3 Polyether-amine 0 1.09 0 1.09 0 1.09 0 1.09 0 1.09 Silane 3.31 3.31 3.31 3.31 3.31 3.31 2.16 2.16 4.32 4.32 Additive 1 1 1 1 1 1 1 1 1 1 1 Additive 2 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 Additive 3 1 1 1 1 1 1 1 1 1 1 Additive 4 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 Additive 5 3 3 3 3 3 3 3 3 3 3 Additive 6 2 2 2 2 2 2 2 2 2 2 DPG 1 - 1 - 1 - 1 - 1 - TBBS 1 1 1 1 1 1 1 1 1 1 Sulfur 1.65 1.65 1.65 1.65 1.65 1.65 1.65 1.65 1.65 1.65

[0131] The material properties determined for the relevant vulcanized rubber are summarized in Table 4.

[0132] Table 4 - Material properties

[0133]

[0134]

[0135] The results summarized in Table 4 show that the polyetheramine exhibits a favorable accelerating effect, which is manifested as a shortening of the t10 and t90 times. This means that advantageously, a favorable accelerating effect can be achieved without using DPG and a shorter vulcanization time can be achieved.

[0136] For the properties tested, samples E1 to E4 exhibit a favorable property profile, while wear is unduly adversely affected at higher silica contents.

[0137] In particular, the Payne effect, tested by E’(0.15%) - E’(8%) and G’(1%) - G’(100%), was not deteriorated in samples E1 to E4, and moreover, was improved for E2 and E3, indicating that these vulcanized rubbers exhibit improved rolling resistance.

[0138] Moreover, samples E2 and E4 unexpectedly exhibit improved wear compared to their respective comparative samples.

[0139] Furthermore, samples E2 and E4 show a favorable improvement in tear propagation resistance, as an indicator of better durability, compared to their respective comparative samples.

[0140] In addition, all polyetheramine-containing samples show an increase in high-speed tear energy (HSTE) compared to their comparative samples, as an indicator of improved tear properties on rough roads or generally of higher durability of the blend.

[0141] In summary, samples E2 and E4 are considered particularly advantageous, with sample E2 in particular having a particularly favorable property profile.

[0142] D. Additional series of tests:

[0143] To examine the applicability of vulcanized rubber blends with different reinforcing resins, experiments V1 and E1 were conducted in the presence of specific reinforcing resins in five sub-experiments and tested for their t10 / t90 values. Here, 5 phr of the reinforcing resin and 1.25 phr of hexamethoxymethylmelamine (65%) were used in each case. The reinforcing resins used were i) phenol novolak type phenolic resin, ii) resorcinol, iii) resorcinol-formaldehyde novolak type phenolic resin, iv) phenol-formaldehyde-urethane novolak type phenolic resin, and v) resorcinol-formaldehyde-styrene novolak type phenolic resin. Compared to DPG, the accelerating effect of i), iii), iv), and v) was improved, while ii) remained at a comparable level.

Claims

1. A vulcanizable rubber compound comprising: a) one or more diene rubbers, b) one or more fillers selected from the group consisting of silica, and c) one or more polyetheramines in a combined weight portion ranging from 0.1 to 10 phr, wherein these polyetheramines are selected from the group consisting of polyetheramines having the formula I): I)R 1 R 2 N-(R 5 ) m -X-R 6 -NR 3 R 4 , wherein R 1 , R 2 , R 3 and R 4 are each independently hydrogen or a branched or unbranched hydrocarbon group having 1 to 10 carbon atoms, where m is 0 or 1, wherein R 5 and R 6 are each independently a branched or unbranched hydrocarbon chain having 1 to 10 carbon atoms wherein X is a polyether chain having the formula II): II)-(CHR 7i -CHR 8i -O) x - where x is in the range from 2 to 30, and where R in each monomer unit i 7i and R 8i is, in each case independently of one another and independently of the other monomer units in the polyether chain, hydrogen or a hydrocarbon group having 1 or 2 carbon atoms The vulcanizable rubber compound comprises natural polyisoprene in a weight portion ranging from 25 to 100 phr as the diene rubber, and The vulcanizable rubber compound comprises the one or more fillers in a combined weight portion of 55 phr or less.

2. The vulcanizable rubber blend according to claim 1, wherein, The vulcanizable rubber compound comprises butadiene rubber as the diene rubber, and / or wherein the vulcanizable rubber compound comprises synthetic polyisoprene as the diene rubber.

3. The vulcanizable rubber blend according to any one of claims 1 and 2, wherein, The vulcanizable rubber compound comprises the one or more fillers in a combined weight portion ranging from 5 to 55 phr.

4. The vulcanizable rubber blend according to any one of claims 1 to 3, wherein, R in each monomer unit i 7i and R 8i are each independently of one another and independently of the other monomer units in the polyether chain hydrogen or methyl in each case.

5. The vulcanizable rubber blend according to any one of claims 1 to 4, wherein The polyether chain comprises one or more first monomer units i1 having the formula IV): IV)-(CHR 7i -CH2-O)-, and / or wherein the polyether chain comprises one or more second monomer units i2 having the formula V): V)-(CH2-CH2-O)-, and / or wherein the polyether chain comprises one or more third monomer units i3 having the formula VI): VI)-(CH2-CHR 8i -O)-。 6. The vulcanizable rubber blend according to any one of claims 1 to 5, wherein, The one or more polyetheramines are selected from the group consisting of: - polyetheramines having the formula VII): VII) H2N-(CH(CH3)-CH2-O) x1 -CH2CH(CH3)-NH2, wherein x1 is in the range of 2 to 6, and - polyetheramines having the formula VIII): VIII)H2N-X-CH2CH(CH3)-NH2, wherein X is a polyether chain composed of two or more monomer units selected from the group consisting of having the formula III b ) of the first monomer unit i 1b : III b )-(CH(CH3)-CH2-O)-, Having formula IV b ) of the second monomer unit i 2b : IV b )-(CH2-CH2-O)-, and Having formula V b ) of the third monomer unit i 3b : V b )-(CH2-CH(CH3)-O)-, wherein the number x of the combination of the first monomer unit i and the third monomer unit i in the polyether chain is in the range of 2 to 5, and the number x of the second monomer unit i in the polyether chain is in the range of 8 to 10. 1b and the third monomer unit i 3b is in the range of 2 to 5, where the number x of the second monomer unit i 1b / 3b in the polyether chain 2b is in the range of 8 to 10. 2b ​ 7. The vulcanizable rubber blend according to any one of claims 1 to 6, wherein The combined weight portion of natural polyisoprene and the one or more fillers is in the range of 30 to 150 phr.

8. The vulcanizable rubber compound according to any one of claims 1 to 7, wherein, The vulcanizable rubber compound comprises carbon black as an additional filler.

9. A vulcanized rubber producible or produced by vulcanizing the vulcanizable rubber compound according to any one of claims 1 to 8.

10. A rubber product, in particular a pneumatic vehicle tire, comprising the vulcanized rubber according to claim 9.

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