Vulcanizable rubber mixtures, vulcanized materials, and rubber products

Abstract

The present invention relates to vulcanizable rubber mixtures containing a) a diene rubber, b) silica, c) specific polyetheramines in a total mass proportion ranging from 0.1 to 10 phr, and d) one or more liquid polybutadienes having a number-average molar mass Mn ranging from 500 to 20,000 g / mol, measured using GPC.

Description

[Technical Field]

[0001] The present invention relates to vulcanizable rubber compounds, vulcanizates producible therefrom, and rubber articles, particularly pneumatic vehicle tires, containing the vulcanizates. [Background technology]

[0002] While the automotive industry has been shaped by numerous technological innovations, it is also one of the sectors that has faced fundamental challenges since the beginning of the 21st century. Rising customer awareness of environmental issues such as emission profiles and resource efficiency is calling for new concepts in mobility. At the same time, demands for improved vehicle functionality and requirements regarding driving safety are increasing. Meeting these challenges is not just the job of actual car manufacturers. In fact, many of these challenges are heavily influenced by the properties of vehicle tires, so optimizing tire properties is a key area of ​​innovation.

[0003] The key factors for optimizing the properties of vehicle tires and other rubber products, such as belts, drive belts, and hoses, are the vulcanizable rubber compounds used in their manufacture and the rubber stock obtained by vulcanization. Many relevant properties of pneumatic vehicle tires, such as wet grip, rolling resistance, and wear behavior, are closely related to the composition of the rubber stock, for example, of the tread. Therefore, the focus of much research effort is on optimizing the properties of the rubber compositions used, which usually imposes very high requirements. At the same time, conflicting objectives exist with regard to many properties of vehicle tires. This means that these properties cannot be optimized independently of each other, and improving one parameter may worsen another.

[0004] In recent decades, great advances have been made in the field of composition development, where a key innovation has been the at least partial replacement of, for example, carbon black-based fillers with silicon-containing compounds, in particular silicon dioxide compounds such as fumed silica and precipitated silica.

[0005] EP 2725059 A1 discloses that the combination of polyetheramines with silica results in advantageous rubber compounds with improved levels of performance, particularly with respect to wear behavior and the conflicting objectives between rolling resistance and wet grip. Furthermore, it has been found that the corresponding rubber compounds have improved processing properties. Additional information on the technical background of polyetheramines is disclosed, for example, in WO 2013 / 092526 A1, U.S. Patent Application Publication No. 2008 / 033082 A1, and WO 2016 / 030469 A1. Summary of the Invention [Problem to be solved by the invention]

[0006] Although the vulcanizable rubber compounds known from the prior art are capable of achieving generally advantageous results in many respects, it is believed that the corresponding compositions and the vulcanizates producible therefrom are often still in need of improvement with regard to application-related properties, in particular in order to meet the requirements of modern pneumatic vehicle tires for high-performance applications.

[0007] The main object of the present invention was to overcome or at least mitigate the drawbacks of the prior art and to provide an advantageous vulcanizable rubber compound having an advantageous property profile and corresponding vulcanizates producible therefrom.

[0008] In particular, it is an object of the present invention to provide vulcanizable rubber compounds that have excellent processing properties, which desirably can reduce the need for compounds that are potentially harmful to health and / or the environment, particularly guanidine-based accelerators.

[0009] It was further an object of the present invention to provide vulcanizable rubber compounds and corresponding vulcanizates producible therefrom which have excellent mechanical properties, in particular with regard to improved stiffness and robustness, but also with regard to improved tear properties, in particular on rough roads, and in particular with regard to improved wear properties.

[0010] In particular, the object of the present invention was to optimally resolve the existing objective conflict between processing properties and mechanical properties.

[0011] In this context, a further object of the present invention was to ensure that the vulcanizable rubber compounds and vulcanizates provided can be produced as far as possible using manufacturing processes and materials already in use today in the field of rubber processing.

[0012] A further object of the present invention was to provide corresponding rubber articles comprising the vulcanizates provided, in particular pneumatic vehicle tires, having advantageous properties.

[0013] The inventors of the present invention have now surprisingly found that the above object can be achieved when the vulcanizable rubber compound, as defined in the claims, contains not only a diene rubber and silica, but also specific parts by weight of specific polyetheramines and liquid polybutadiene. [Means for solving the problem]

[0014] The above-mentioned object is therefore achieved by the subject matter of the invention as defined in the claims. Preferred embodiments according to the invention will become apparent from the dependent claims and the following description. DETAILED DESCRIPTION OF THE INVENTION

[0015] In particularly preferred embodiments, the embodiments referred to below as preferred are combined with features of other embodiments referred to as preferred. Thus, combinations of two or more of the embodiments referred to below as particularly preferred are most highly preferred. Similarly, preferred are embodiments in which features of one embodiment referred to as somewhat preferred are combined with one or more additional features of other embodiments referred to as somewhat preferred. Preferred vulcanizate, rubber article, and use features will be apparent from the features of the preferred vulcanizable rubber compounds.

[0016] When the following text discloses, for a compound component, such as a diene rubber or polyetheramine, not only a specific amount / part of said compound component but also a preferred embodiment of the compound component, the text also specifically discloses the specific amount / part of the compound component of the preferred embodiment. Furthermore, for the corresponding specific total amount / part of the compound component, it is disclosed that at least a portion of the compound component may be of the preferred embodiment, and it is also specifically disclosed that the compound component of the preferred embodiment may be present in a specific amount / part within the specified total amount or total part range.

[0017] The present invention provides a vulcanizable rubber compound comprising: a) one or more diene rubbers; b) one or more fillers selected from the group consisting of silica; c) one or more polyetheramines in a total weight range of 0.1 to 10 phr, Formula I): I)R 1 R 2 N-(R 5 ) m -XR 6 -NR 3 R 4 and wherein in formula I) R 1 , R 2 , R 3 , and R4 are each independently hydrogen or a branched or unbranched hydrocarbon radical having 1 to 10 carbon atoms, m is 0 or 1, and R 5 and R 6 are each independently a branched or unbranched hydrocarbon chain having 1 to 10 carbon atoms; X is a group represented by formula II): II)-(CHR 7i -CHR 8i -O) x - In formula II), x is in the range of 2 to 30, and R 7i and R 8i is in each occurrence independently and independently of the other monomer units in the polyether chain, hydrogen or a hydrocarbon radical having 1 or 2 carbon atoms; d) one or more liquid polybutadienes having a number average molar mass Mn, measured by GPC, in the range of 500 to 20,000 g / mol; The present invention relates to a vulcanizable rubber compound containing

[0018] The vulcanizable rubber compound itself and its typical components, as well as the conventional manufacturing process for obtaining the corresponding vulcanizable rubber compound by mixing the components in particular, are well known to those skilled in the art of rubber processing.

[0019] According to standard practice, the above-defined components of a vulcanizable rubber compound are each referred to as "one or more." As is customary in the industry, the term "one or more" refers to the chemical nature of the corresponding compound, not its molar amount. For example, a vulcanizable rubber compound may contain only SBR as the diene rubber, which means that the vulcanizable rubber compound contains multiple corresponding molecules.

[0020] When parts by weight are given in the text below, they are often given as the total parts by weight of one or more components as is customary in the industry, thereby indicating that the combined parts by weight of the correspondingly formed components meet the corresponding criteria.

[0021] The unit phr (parts by weight per 100 parts by weight of rubber) used herein is a conventional indication of the amount of compound in the rubber industry and represents the weight parts of components in a rubber compound based on the amount of high molecular weight rubber (having a number average molar mass Mn of more than 60,000 g / mol as measured by GPC) present in the rubber compound, with the total weight parts of the high molecular weight rubber in the rubber compound corresponding to 100 phr. The unit phf (parts by weight per 100 parts by weight of filler) is also a conventional indication of the amount in the rubber industry of compound compounds, particularly filler coupling agents, and is based on the weight of the filler present in the rubber compound. In the context of the present invention, the unit phf is based only on the silica present in the vulcanizable rubber compound, the total weight parts of which correspond to 100 phf. In other words, other fillers, such as carbon black, which may be present, are not included in the phf calculation.

[0022] The vulcanizable rubber compound according to the present invention contains at least one diene rubber. As understood by those skilled in the art, diene rubber refers to rubber obtained by (co)polymerization of dienes and / or cycloalkenes, which consequently have C=C double bonds in the main chain or in side groups. The advantage of the vulcanizable rubber compound according to the present invention is that it has high flexibility in terms of the diene rubber used, so that in principle any diene rubber commonly used in industry can be used. In this regard, however, the inventors prefer vulcanizable rubber compounds according to the invention, in which 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 halobutyl rubber, and 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 the one or more diene rubbers are particularly preferably selected from the group consisting of solution-polymerized styrene-butadiene rubber and emulsion-polymerized styrene-butadiene rubber. In this regard, also preferred are vulcanizable rubber compounds according to the invention, in which at least one diene rubber, preferably all of the one or more diene rubbers, are end-group-modified and / or chain-modified diene rubbers, preferably end-group-modified diene rubbers, the modification being with one or more functional groups selected from the group consisting of hydroxyl, ethoxy, epoxy, siloxane, amino, aminosiloxane, carboxyl, phthalocyanine, and silane-sulfide groups.

[0023] In particular, SBR, BR, and IR / NR have been found to be suitable diene rubbers for obtaining vulcanizable rubber compounds which can be converted by vulcanization into particularly effective vulcanizates.

[0024] Therefore, first preference is given to a vulcanizable rubber compound according to the invention which comprises, as diene rubber, parts by weight of styrene-butadiene rubber, preferably solution-polymerized styrene-butadiene rubber, preferably in the range of 50 to 98 phr, particularly preferably in the range of 55 to 96 phr, most particularly preferably in the range of 60 to 90 phr.

[0025] Additionally or alternatively, preferred vulcanizable rubber compounds according to the invention comprise as diene rubber, preferably 1 to 35 parts by weight, particularly preferably 2 to 30 parts by weight, and most particularly preferably 5 to 25 parts by weight of butadiene rubber. The butadiene rubber may be, for example, a so-called high-cis-butadiene rubber or a low-cis-butadiene rubber, where high-cis-butadiene rubber refers to a polybutadiene having a cis content of 90% or more by mass.

[0026] Additionally or alternatively, preferred vulcanizable rubber compounds according to the present invention contain natural and / or synthetic polyisoprene, preferably natural polyisoprene, in a total weight ratio of 1 to 30 phr, particularly preferably 2 to 20 phr, and most particularly preferably 5 to 15 phr, as diene rubber. However, particularly for truck tire applications, weight ratios of 60 to 100 phr, preferably 60 to 80 phr, are also contemplated. The natural and / or synthetic polyisoprene may be cis-1,4-polyisoprene or 3,4-polyisoprene. However, it is preferred to use cis-1,4-polyisoprene, particularly one with a cis-1,4 content of 90% or more by mass.

[0027] It has been found to be advantageous to mix two or more diene rubbers in order to optimally adapt the physicochemical / mechanical properties of the vulcanizates that can be produced to the requirements of a particular application.Therefore, preferred vulcanizable rubber compounds according to the invention comprise two or more, preferably three or more different diene rubbers as diene rubbers, particularly preferably SBR and NR and / or BR, and most preferably SBR, NR and BR.

[0028] Additionally or alternatively, preference is given to vulcanizable rubber compounds according to the invention in which the diene rubber has a weight-average molar mass Mw, determined by GPC, in the range of 150,000 to 5,000,000 g / mol, preferably in the range of 250,000 to 2,500,000, particularly preferably in the range of 300,000 to 1,500,000. In the context of the present invention, the determination of the number-average molar mass or the weight-average molar mass is carried out by gel permeation chromatography in accordance with DIN 55672-1:2016-03 (GPC with tetrahydrofuran as eluent, polystyrene standards; size exclusion chromatography).

[0029] The vulcanizable rubber compound according to the present invention comprises one or more fillers selected from the group consisting of silica. In the context of the present invention, the German original text of this application uses the German term "Kieselsaeure" (silicic acid), which is commonly used in the industry, and related compounds are sometimes called "Silika" based on the English term "silica." For those skilled in the rubber processing industry, this traditional German term refers to amorphous, i.e., non-crystalline, silicon dioxide, particularly so-called fumed silica and precipitated silica. In other words, the vulcanizable rubber compound according to the present invention is a rubber compound comprising one or more fillers selected from the group consisting of fumed silica and precipitated silica, particularly preferably precipitated silica.

[0030] Basically, one or more fillers are used in a volume of 35 to 400 m 2 / g, preferably 35 to 350 m 2 / g, particularly preferably 85 to 320 m 2 Preference is given to vulcanizable rubber compounds according to the invention having a nitrogen surface area (BET surface area) according to DIN ISO 9277:2014-01 in the range of 30 to 400 m / g, most particularly preferably in the range of 120 to 235 m / g. Additionally or alternatively, one or more fillers may be present in an amount of 30 to 400 m / g. 2 / g, preferably 330 to 330m 2 / g, particularly preferably 80 to 300m2 / g, most particularly preferably 115 to 200m 2 Preferably, vulcanizable rubber compounds according to the present invention have a CTAB surface area according to ASTM D3765-03 in the range of 1000 / g.

[0031] With regard to the amount of filler that can be used, the inventors have found that the vulcanizable rubber compounds according to the invention advantageously show excellent results even at high filler contents. However, the inventors believe that the solutions specified in the context of the invention are most advantageous, especially at moderate filler contents. Therefore, vulcanizable rubber compounds according to the invention are preferred which contain one or more fillers in a total amount of parts by weight ranging from 5 to 250 phr, preferably from 20 to 180 phr, particularly preferably from 30 to 140 phr, and most particularly preferably from 40 to 110 phr.

[0032] In addition to the silica used according to the present invention, additional fillers may also be present, thereby making it possible to specifically adjust the properties of the vulcanizable rubber compound. Vulcanizable rubber compounds according to the present invention are preferred, comprising one or more additional fillers selected from the group consisting of carbon black, aluminum hydroxide, titanium dioxide, magnesium oxide, and phyllosilicates, with the total weight of the additional fillers preferably ranging from 0.1 to 100 phr, particularly preferably from 0.5 to 50 phr. The carbon black used preferably has an iodine adsorption capacity according to ASTM D1510 of 30 to 250 g / kg, preferably 30 to 180 g / kg, particularly preferably 40 to 130 g / kg, and a DBP value according to ASTM D2414 of 30 to 200 ml / 100 g, preferably 70 to 200 ml / 100 g, particularly preferably 90 to 200 ml / 100 g.

[0033] The vulcanizable rubber compound according to the present invention comprises at least one polyetheramine having a specific structure. Polyetheramines are well known to those skilled in the art. These are polyetherpolyols in which the terminal hydroxyl groups have been converted to amino groups by an amination reaction to produce polyamines. When linear, i.e., unbranched, polyetherdiols are aminated, the polyetheramines are diamines of polyalkylene glycols. The base polyetherdiol is preferably prepared from an alkylene oxide, such as butylene oxide, ethylene oxide, or propylene oxide. Polyetheramines are commercially available, in particular from Huntsman, under the trade names Jeffamine D-230, ED-600, ED-900, or EDR-148.

[0034] The polyetheramines used according to the invention are selected from the group consisting of polyetheramines of formula I): I)R 1 R 2 N-(R 5 ) m -XR 6 -NR 3 R 4 (In the formula, R 1 , R 2 , R 3 , and R 4 are each independently hydrogen or a branched or unbranched hydrocarbon radical having 1 to 10 carbon atoms, m is 0 or 1, and R 5 and R 6 are each independently a branched or unbranched hydrocarbon chain having 1 to 10 carbon atoms; X is a member of formula II): II)-(CHR 7i -CHR 8i -O) x - In formula II), x is in the range of 2 to 30, and R 7i and R 8iis in each occurrence, independently and independently of the other monomer units in the polyether chain, hydrogen or a hydrocarbon group having 1 or 2 carbon atoms).

[0035] R 1 , R 2 , R 3 , and R 4 The organic radicals in the formula (I) define the radicals of the amino groups of the diamine and are generated from the materials used in the amination reaction. As understood by those skilled in the art, these radicals are in principle independent of each other. This is true for example for R 2 Even if R is a hydrocarbon radical 1 means that R may be hydrogen. 1 , R 2 , R 3 , and R 4 are each independently hydrogen or a branched or unbranched, preferably unbranched, hydrocarbon radical having 1 to 5 carbon atoms, preferably 2 to 5 carbon atoms. 1 and R 2 At least one of the radicals and / or R 3 and R 4 Particularly preferred are vulcanizable rubber compounds according to the invention, in which at least one of the radicals is hydrogen. 1 Radicals and R 3 Radicals and / or R 2 Radicals and R 4 Most particularly preferred are vulcanizable rubber compounds according to the invention in which the radicals are identical. 1 , R 2 , R 3 , and R 4 Particular preference is given to vulcanizable rubber compounds according to the invention in which the radical is hydrogen.

[0036] One of the amino groups may be bonded directly to the polyether chain X (m=0) or through a hydrocarbon chain (m=1). In preferred polyetheramines, which are prepared from alkylene oxides, one of the amino groups is bonded directly to the polyether chain X (m=0) and the other amino group is bonded through a hydrocarbon chain R 6 The hydrocarbon chains are linked together, and this hydrocarbon chain ultimately becomes essentially the last building block of the polyether chain. However, this last building block no longer contains an oxygen atom as a result of the amination, and is therefore no longer considered part of the polyether chain X. Therefore, R 5 and R 6 are each independently a branched or unbranched hydrocarbon chain having 1 to 5 carbon atoms, preferably 2 or 3 carbon atoms. 6 Particular preference is given to vulcanizable rubber compounds according to the invention, in which is 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.

[0037] The polyether chain X contains x repeating units. Vulcanizable rubber compounds according to the invention in which x is in the range of 2 to 15 are preferred.

[0038] In each unit of the polyether chain X, i.e., the different monomer units identified herein by serial number i from i=1 to i=x, R 7i and R 8i are essentially independent of each other, specifically, R in each monomer unit 7i and R 8i Not only that, but all R 7i and all R 8i R in each monomer unit i is also independent. Since alkylene oxides with relatively short chain lengths are fundamentally advantageous, 7i and R 8iis in each case independently hydrogen or a methyl group, independent of the other monomer units in the polyether chain. 7i and R 8i Particular preference is given to vulcanizable rubber compounds according to the invention in which at least one of the radicals is in each case hydrogen.

[0039] In this regard, those skilled in the art will appreciate that R 7i and R 8i It will be appreciated that the nature of the radicals will depend inter alia on the chemical nature of the compounds used to prepare the polyetheramine, in particular the alkylene oxides used, and that more complex polyetheramines will be obtained, especially when different alkylene oxides are mixed together during the preparation of the polyetheramine.

[0040] According to the inventors, the polyether chain is represented by formula IV: IV)-(CHR 7i -CH2-O)- (In the formula, R 7i is preferably the same for all first monomer units i1, and R 7i is particularly preferably a methyl group for all first monomer units i1). and / or The polyether chain has the formula V): V)-(CH2-CH2-O)- and / or The polyether chain has the formula VI): VI)-(CH2-CHR 8i -O)- (In the formula, R 8i is preferably the same for all third monomer units i3, and R 8i is particularly preferably a methyl group for all third monomer units i3). and one or more third monomer units i3 of Preference is given to vulcanizable rubber compounds according to the invention in which the polyether chains preferably consist of these monomer units.

[0041] Regarding these monomer units, the vulcanizable rubber compound according to the present invention is basically preferred in which the number of first monomer units i1 in the polyether chain x1 is in the range of 1 to 7, preferably in the range of 2 to 6, particularly preferably in the range of 2 to 5, and / or the number of second monomer units i2 in the polyether chain x2 is in the range of 1 to 15, preferably in the range of 2 to 12, particularly preferably in the range of 3 to 10, and / or the number of third monomer units i3 in the polyether chain x3 is in the range of 1 to 7, preferably in the range of 2 to 6, particularly preferably in the range of 2 to 5. In this regard, the polyether chain x 1 / 3 Particularly preferred is a vulcanizable rubber compound according to the present invention, wherein the total number of first monomer units i1 and third monomer units i3 is in the range of 2-10, preferably 3-7.

[0042] In this context, firstly, most preferred are vulcanizable rubber compounds according to the invention in which the polyether chains consist preferably to an extent of more than 50%, particularly preferably to an extent of more than 75% and particularly preferably substantially completely of first monomer units i1, the number of first monomer units i1 in the polyether chain x1 being in the range from 1 to 5, preferably in the range from 2 to 4. Corresponding polyetheramines are commercially available, for example under the trade name Jeffamine D-230, in which x1 is about 2.5.

[0043] Additionally or alternatively, vulcanizable rubber compounds according to the invention having mixed polyether chains are also particularly preferred, i.e., the polyether chains comprise two or more, preferably three or more, monomer units selected from the group consisting of the first monomer unit i1, the second monomer unit i2, and the third monomer unit i3, and the polyether chains preferably consist of these monomer units. Relevant for most applications are vulcanizable rubber compounds according to the invention in which at least some, preferably all, of the two or more monomer units are randomly distributed in the polyether chain.

[0044] For mixed polyether chains, first, polyether chain x 1 / 3 Most particularly preferred are vulcanizable rubber compounds according to the invention, in which the total number of first and third monomer units i1 and i3 in the polyether chain x2 is in the range of 2 to 5, and the number of second monomer units i2 in the polyether chain x2 is in the range of 7 to 12. Corresponding polyetheramines are commercially available, for example, under the trade name Jeffamine e ED-600, in which x2 is about 9 and x 1 / 3 is about 3.6.

[0045] For mixed polyether chains, in addition or instead, polyether chain x 1 / 3 Also most particularly preferred are vulcanizable rubber compounds according to the invention, in which the total number of first and third monomer units i1 and i3 in the polyether chain x2 is in the range of 4 to 8, and the number of second monomer units i2 in the polyether chain x2 is in the range of 10 to 15. Corresponding polyetheramines are commercially available, for example, under the trade name Jeffamine e ED-900, in which x2 is about 12.5 and x 1 / 3 is about 6.

[0046] The present inventors believe that the use of such polyetheramines, particularly the commercial products Jeffamine D-230 and ED-600, which are typical representatives thereof, is preferred for achieving the objects of the present invention.

[0047] Thus, one or more polyetheramines may be polyetheramines of formula VII): VII) H2N-(CH(CH3)-CH2-O) x1 -CH2CH(CH3)-NH2 (wherein x1 is in the range of 2 to 6, preferably in the range of 2 to 5, particularly preferably in the range of 2 to 4, and most preferably in the range of 2 to 3), polyetheramines of formula VIII): VIII) H2N-X-CH2CH(CH3)-NH2 (Wherein X is Formula IV b ) the first monomer unit i 1b : IV b )-(CH(CH3)-CH2-O)-, Formula V b ) the second monomer unit i 2b : V b )-(CH2-CH2-O)-, and Equation VI b ) the third monomer unit i 3b : VI b )-(CH2-CH(CH3)-O)- a polymer chain consisting of two or more types of monomer units selected from the group consisting of Polyether chain x 1b / 3b The first monomer unit i in 1b and the third monomer unit i 3b The total number of polyether chains x is in the range of 2 to 5. 2b The second monomer unit i in 2b The number of (ranges from 8 to 10) Particularly preferred are vulcanizable rubber compounds according to the invention selected from the group consisting of:

[0048] Also preferred are vulcanizable rubber compounds according to the invention in which, based on the preparation or preparability of the polyetheramines, one or more polyetheramines are preparable by polymerization of alkylene oxides followed by amination, the alkylene oxides being preferably selected from the group consisting of butylene oxide, ethylene oxide, propylene oxide, and mixtures of these compounds, preferably propylene oxide. Additionally or alternatively, particularly preferred are vulcanizable rubber compounds according to the invention in which one or more polyetheramines are saturated compounds.

[0049] The polyetheramines preferably used are compounds with a relatively short chain length. In particular, vulcanizable rubber compounds according to the invention are particularly preferred, in which the weight-average molar mass of one or more polyetheramines is in the range of 100 to 800 g / mol, preferably in the range of 130 to 650 g / mol, particularly preferably in the range of 190 to 400 g / mol.

[0050] To further optimize the properties of the vulcanizable rubber compounds according to the invention and the vulcanizates producible therefrom, the inventors believe that different polyetheramines can be combined, and in particular preferred polyetheramine combinations such as can be achieved by combining, for example, the commercially available products Jeffamine D-230 and ED-600. Thus, vulcanizable rubber compounds according to the invention that contain two or more different polyetheramines are preferred.

[0051] Regardless of the exact chemical nature of the polyetheramines, the inventors have been able to identify particularly advantageous parts by weight of these components, which allow the above-mentioned objectives to be particularly well achieved. Specifically, preferred vulcanizable rubber compounds according to the invention contain one or more polyetheramines in a total amount ranging from 0.2 to 8 phr, preferably from 0.4 to 6 phr.

[0052] The vulcanizable rubber compound according to the present invention further contains one or more liquid polybutadienes, which have a number-average molar mass Mn in the range of 500 to 20,000 g / mol, as determined by GPC. Liquid polybutadienes are butadiene-based polymers. Corresponding liquid polybutadienes are generally known to those skilled in the art and are commercially available. Background information is found, for example, in EP 3303004 A1. Those skilled in the art will understand that the criteria for "liquid" are clear from the number-average molar mass indicated. In this context, the term "liquid" means that the polybutadiene is liquid at a temperature of 23°C and 100 kPa. A compound is considered liquid in any case if its kinematic viscosity at 23°C, measured according to DIN 53211:1987-06, is 20 Pa·s or less, preferably 10 Pa·s or less.

[0053] Liquid polybutadienes are polymers of butadiene, such as butadiene rubber, but their average molar mass is significantly lower than that of rubber, making them easily distinguishable from rubber. In this regard, those skilled in the art will understand that liquid polybutadienes are not included in the high molecular weight rubbers when calculating parts by weight in phr. In this regard, preferred vulcanizable rubber compounds according to the present invention are those in which one or more liquid polybutadienes have a number-average molar mass Mn, measured by GPC, in the range of 1,000 to 15,000 g / mol, preferably in the range of 2,000 to 12,000 g / mol, and particularly preferably in the range of 3,000 to 9,000 g / mol.

[0054] Based on the experiments carried out, the inventors have succeeded in identifying particularly advantageous parts by weight of liquid polybutadienes. Specifically, preferred vulcanizable rubber compounds according to the invention comprise one or more liquid polybutadienes in a total weight ratio ranging from 1 to 70 phr, preferably from 2 to 50 phr, particularly preferably from 3 to 40 phr, and most particularly preferably from 4 to 35 phr. Additionally or alternatively, preferred vulcanizable rubber compounds according to the invention comprise one or more liquid polybutadienes in a weight ratio of 30% or more, preferably 60% or more, particularly preferably 90% or more, and most particularly preferably essentially 100% of the total weight of all plasticizers in the vulcanizable rubber compound.

[0055] In this connection, the inventors have succeeded in identifying particularly preferred liquid polybutadienes for obtaining vulcanizable rubber compounds according to the invention which have a particularly excellent property profile.

[0056] First preference is given to vulcanizable rubber compounds according to the invention, in which the one or more liquid polybutadienes have a glass transition temperature Tg by DSC in the range of −95° C. to −30° C., preferably in the range of −90° C. to −40° C. In the context of the present invention, the glass transition temperature Tg is measured in the customary manner by dynamic scanning calorimetry (DSC according to DIN 53765:1994-03 or ISO 11357-2:1999-03, calibrated DSC with cryogenic equipment, calibration according to the type of instrument and the manufacturer's instructions, sample in an aluminium crucible with an aluminium lid, cooling at 10° C. / min to a temperature below −120° C.).

[0057] Additionally or alternatively, preference is given to vulcanizable rubber compounds according to the invention in which the one or more liquid polybutadienes have a vinyl content in the range of 10% to 40%, preferably in the range of 15% to 35%, particularly preferably in the range of 20% to 40%, and / or the one or more liquid polybutadienes have a 1,4-trans content in the range of 40% to 70%, preferably in the range of 45% to 60%. Corresponding contents are, for example, 13It can be measured by C-NMR.

[0058] Experiments have shown that it is most preferable to use chain- and / or end-modified liquid polybutadienes, in particular silicon-modified liquid polybutadienes, as disclosed, for example, in EP 3303004 A1. The corresponding silicon-modified liquid polybutadienes have been found to be particularly suitable for combining excellent wear resistance with particularly advantageous mechanical properties, especially at average parts by weight in the range of 1 to 15 phr, preferably 2 to 12 phr. Therefore, vulcanizable rubber compounds according to the invention are particularly preferred, in which the one or more liquid polybutadienes are selected from the group consisting of modified liquid polybutadienes, preferably organosilicon-modified liquid polybutadienes, and particularly preferably end-modified liquid polybutadienes.

[0059] Most particularly preferred are vulcanizable rubber compounds according to the invention, in which the one or more liquid polybutadienes are selected from the group consisting of organosilicon-modified liquid polybutadienes modified by radicals of formula A1): A1)(R a R b R c )Si- (In the formula, R a , R b , and R c are each independently a branched or unbranched alkoxy group or an alkyl group having 1 to 10 carbon atoms, and R a , R b , and R c At least one of the radicals is an alkoxy group). In this respect, particular preference is given to vulcanizable rubber compounds according to the invention, in which the one or more liquid polybutadienes are selected from the group consisting of organosilicon-modified liquid polybutadienes modified with radicals of formula A2): A2)(R a R b R c )Si-R d -R e - (In the formula, Ra , R b , and R c are each independently a branched or unbranched alkoxy or alkyl group having 1 to 10 carbon atoms, and R a , R b , and R c At least one of the radicals is an alkoxy group, and R d is a branched or unbranched hydrocarbon chain having 1 to 10 carbon atoms, and R e is preferably a functional group selected from the group consisting of ester, ether, urethane, urea, amine, amide, thioether, and thioester).

[0060] In addition to the diene rubber, filler, polyetheramine, and liquid polybutadiene, additional typical ingredients may be used in the vulcanizable rubber compound of the present invention, for example, to influence the physicochemical properties, such as processing and vulcanization properties, of the vulcanizable rubber compound or to optimize the mechanical properties of the vulcanizates producible therefrom.

[0061] In this respect, first preference is given to vulcanizable rubber compounds according to the invention which comprise one or more additional added substances, preferably selected from the group consisting of reinforcing resins, coupling agents and further plasticizers, preferably comprising the additional added substances in a total amount of parts by weight ranging from 10 to 100 phr, preferably from 20 to 80 phr, particularly preferably from 30 to 60 phr.

[0062] Examples that may be mentioned are vulcanizable rubber compounds according to the invention in which the reinforcing resin is selected from the group consisting of resorcinol-formaldehyde resins, in particular resorcinol-hexamethoxymethylmelamine resins (HMM) or resorcinol-hexamethylenetetramine resins (HEXA), and modified phenolic resins. Those skilled in the art of rubber processing can easily distinguish resins from diene rubbers, and in practice, this is done primarily by their average molar mass. In this regard, examples that may be mentioned are vulcanizable rubber compounds according to the invention in which 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.

[0063] An example that may also be mentioned is a vulcanizable rubber compound according to the invention, in which 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, preferably comprising the coupling agent in a total part by weight ranging from 0.2 to 30 phf, preferably from 1 to 15 phf.

[0064] Further examples which may be mentioned are vulcanizable rubber compounds according to the invention, wherein the further plasticizer is selected from the group consisting of mineral oils, synthetic plasticizers, fatty acids, fatty acid derivatives, plasticizer resins, factices, glycerides, terpenes, biomass-to-liquid oils (BTL oils) and rubber-to-liquid oils (RTL oils), preferably in a total weight range of 1 to 100 phr, preferably in the range of 10 to 80 phr, particularly preferably in the range of 20 to 60 phr.

[0065] Preferred are vulcanizable rubber compounds according to the invention which additionally or alternatively comprise one or more additional additives, preferably selected from the group consisting of methylene donors, antioxidants such as N-phenyl-N'-(1,3-dimethylbutyl)-p-phenylenediamine (6PPD), N,N'-diphenyl-p-phenylenediamine (DPPD), N,N'-ditolyl-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, chewing aids such as 2,2'-dibenzamidodiphenyl disulfide (DBD), and processing aids. Preference is given to vulcanizable rubber compounds according to the invention which comprise additional additives in total parts by weight in the range of 0.1 to 20 phr, preferably in the range of 0.5 to 15 phr, particularly preferably in the range of 1 to 10 phr.

[0066] In terms of vulcanization behavior, preference is given to vulcanizable rubber compounds according to the invention which contain 0.5 to 8.0 phr of sulfur, preferably 0.8 to 6 phr, particularly preferably 1 to 4 phr. In this regard, preference is also given to vulcanizable rubber compounds according to the invention which additionally or instead contain additional vulcanization components, which additional vulcanization components are selected from the group consisting of crosslinkers, 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.

[0067] It is particularly preferred to omit guanidine accelerators, especially diphenylguanidine.Thus, vulcanizable rubber compounds according to the invention are preferred which contain not more than 2 phr, preferably not more than 1 phr, particularly preferably not more than 0.5 phr, and most particularly preferably essentially 0 phr of guanidine accelerators, especially diphenylguanidine.

[0068] Vulcanizates and rubber articles can be produced from the vulcanizable rubber compounds according to the invention in a conventional manner. The corresponding processes for producing vulcanizates or rubber articles may, in addition to producing the vulcanizable rubber compounds according to the invention, additionally comprise, for example, the following steps: x) vulcanizing the vulcanizable rubber compound according to the invention, preferably as part of a rubber blank, particularly preferably as part of an unvulcanized vehicle tire blank, to obtain a vulcanizate, preferably as part of a rubber product, preferably as part of a pneumatic vehicle tire.

[0069] Here, the vulcanizable rubber compounds according to the invention are vulcanized by processes customary in the tire industry, for example by sulfur-based crosslinking.

[0070] The present invention therefore also relates to vulcanizates producible or produced by vulcanization of the vulcanizable rubber compound according to the invention. In this respect, preference is given to vulcanizates according to the invention that are producible by vulcanization at temperatures in the range from 130°C to 200°C, preferably in the range from 150°C to 180°C.

[0071] The present invention therefore also relates to a rubber product comprising a vulcanizate according to the invention. Examples that may be mentioned are rubber products according to the invention selected from the group consisting of shoe soles, drive belts, hoses, conveyor belts and belts. However, in virtually all cases, rubber products according to the invention are preferred which are vehicle tires, preferably pneumatic vehicle tires, which preferably comprise a vulcanizate according to the invention in the tread.

[0072] Finally, the use of the vulcanizable rubber compound according to the invention and / or the vulcanizate according to the invention in the manufacture of rubber products, in particular vehicle tyres, is also disclosed.

[0073] Hereinafter, the present invention and preferred embodiments thereof will be described in more detail and illustrated with reference to experiments. [Example]

[0074] A. Manufacturing of vulcanizable rubber compounds: The vulcanizable rubber compounds were prepared in a laboratory tangential mixer using conventional processes and under conventional conditions in the rubber industry in three stages, including first preparing a base mixture containing all the ingredients except the vulcanization system (sulphur and substances influencing vulcanization) in one or more mixing stages, to which the vulcanization system was then added to obtain the final compound.

[0075] The materials used in this regard are listed in Table 1.

[0076] [Table 1]

[0077] Using each vulcanizable rubber compound, the test was carried out at 160°C to 170°C under pressure. 95 ~t 100 Test specimens were prepared by vulcanization after the rheological properties (measured using a moving die rheometer according to ASTM D5289-19 / ISO6502) were measured. The test specimens were then subjected to the measurement of material properties typical in the rubber industry using the test methods specified in Section B.

[0078] B. Measurement of physicochemical properties of vulcanizates: The following physicochemical properties were measured for the vulcanizable rubber compounds and vulcanizates produced therefrom using the measurement methods listed in Table 2:

[0079] [Table 2]

[0080] C. Test series: Twelve vulcanizable rubber compounds were prepared, the compositions of which are listed in Tables 3 and 4.

[0081] [Table 3]

[0082] [Table 4]

[0083] The parts by weight of polyetheramine were adjusted in each case so that a constant molar amount was introduced.

[0084] The material properties measured for the relevant vulcanizates are summarized in Tables 5 and 6.

[0085] [Table 5]

[0086] [Table 6]

[0087] The results summarized in Tables 5 and 6 show that Polyetheramines 1 and 2 exhibit beneficial acceleration effects, reflected in shorter t10 and t90 times, which means that beneficial acceleration can be advantageously achieved without the use of DPG, resulting in shorter vulcanization times.

[0088] Without liquid polybutadiene, it was found that the use of polyetheramine 1 in V2 and polyetheramine 2 in V3 showed an undesirable decrease in E' (8%) compared to V1, while wear remained virtually unchanged and tensile strength improved only in polyetheramine 2.

[0089] In contrast, samples E1-E6, which additionally contain liquid polybutadiene, surprisingly show a clear improvement in wear behavior compared to their corresponding comparative examples. Furthermore, samples E1 and E2 show an improvement in E' (8%), which indicates higher stiffness and improved handling. Furthermore, samples E1-E4, which contain added polyetheramines, show a favorable improvement in wear, as well as an improvement in tensile strength for both polyetheramines.

[0090] With respect to the surprising improvement in abrasion resistance, the use of organosilicon-modified liquid polybutadienes is particularly advantageous. However, testing has shown that these compounds, at levels of 16 phr or higher, are less effective with respect to E' (8%) and tensile strength compared to lower weight parts. Therefore, with respect to the corresponding conflict of objectives, samples E3 and E4 are considered particularly preferred.

[0091] Furthermore, a particularly advantageous increase in HSTE is observed for polyetheramine 1, while this value remains at a similar level for polyetheramine 2. Samples E1, E3, and E5 therefore also exhibit advantageous tear properties on rough roads. Overall, sample E3 is therefore considered particularly preferred.

Claims

1. 1. A vulcanizable rubber compound comprising: a) one or more diene rubbers; b) one or more fillers selected from the group consisting of silica; c) a total weight range of 0.1 to 10 phr of one or more polyetheramines having Formula I: I)R １ R ２ N-(R ５ ) ｍ -X-R ６ -NR ３ R ４ and wherein in formula I) R １ , R ２ , R ３ , and R ４ are each independently hydrogen or a branched or unbranched hydrocarbon radical having 1 to 10 carbon atoms, m is 0 or 1, and R ５ and R ６ are each independently a branched or unbranched hydrocarbon chain having 1 to 10 carbon atoms; X is a group of formula II): II)-(CHR ７ｉ -CHR ８ｉ -O) ｘ - In formula II), x is in the range of 2 to 30, and R ７ｉ and R ８ｉ is in each occurrence independently and independently of other monomer units in the polyether chain, hydrogen or a hydrocarbon radical having 1 or 2 carbon atoms; d) one or more liquid polybutadienes having a number average molar mass Mn, measured by GPC, in the range of 500 to 20,000 g / mol; 1. A vulcanizable rubber compound comprising:

2. The diene rubber contains styrene-butadiene rubber, and / or the diene rubber contains butadiene rubber, 2. The vulcanizable rubber compound according to claim 1, further comprising natural polyisoprene and / or synthetic polyisoprene as diene rubber.

3. 3. The vulcanizable rubber compound of claim 1 or 2, comprising said one or more fillers in a total parts by weight ranging from 5 to 250 phr.

4. R in each monomer unit i ７ｉ and R ８ｉ 4. The vulcanizable rubber compound of claim 1, wherein each occurrence of is independently hydrogen or a methyl group, independent of other monomer units in the polyether chain.

5. The polyether chain is represented by formula IV: IV)-(CHR ７ｉ -CH ２ -O)- and / or The polyether chain has the formula V: V)-(CH ２ -CH ２ -O)- one or more second monomer units i ２ and / or The polyether chain is represented by formula VI: VI)-(CH ２ -CHR ８ｉ -O)- one or more third monomer units i ３ The vulcanizable rubber compound according to any one of claims 1 to 4, comprising:

6. the one or more polyetheramines polyetheramines of formula VII): VII)H ２ N-(CH(CH ３ )-CH ２ -O) ｘ１ -CH ２ CH(CH ３ )-NH ２ (In the formula, x １ is in the range of 2 to 6) and polyetheramines of formula VIII): VIII)H ２ N-X-CH ２ CH(CH ３ )-NH ２ (Wherein X is Formula III ｂ ) the first monomer unit i １ｂ : III ｂ )-(CH(CH ３ )-CH ２ -O)- Formula IV ｂ ) the second monomer unit i ２ｂ : IV ｂ )-(CH ２ -CH ２ -O)-, and Formula V ｂ ) the third monomer unit i ３ｂ : V ｂ ()-(CH ２ -CH(CH ３ )-O)- a polyether chain consisting of two or more types of monomer units selected from the group consisting of The polyether chain x １ｂ／３ｂ The first monomer unit i in １ｂ and a third monomer unit i ３ｂ The total number of the polyether chains x is in the range of 2 to 5, ２ｂ The second monomer unit i in ２ｂ the number of is in the range of 8 to 10) and The vulcanizable rubber compound according to any one of claims 1 to 5, selected from the group consisting of:

7. 7. The vulcanizable rubber compound of claim 1, comprising the one or more liquid polybutadienes in a total weight range of 1 to 70 phr.

8. 8. The vulcanizable rubber compound according to any one of claims 1 to 7, wherein the one or more liquid polybutadienes are selected from the group consisting of modified liquid polybutadienes, preferably organosilicon modified liquid polybutadienes.

9. A vulcanizate producible or produced by vulcanization of 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 vulcanizate of claim 9.

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