Sulfur-crosslinkable rubber mixture, vulcanized rubber of rubber mixture and vehicle tire
阅读说明：本技术 硫可交联的橡胶混合物、橡胶混合物的硫化橡胶和车辆轮胎 (Sulfur-crosslinkable rubber mixture, vulcanized rubber of rubber mixture and vehicle tire ) 是由 尤利娅·舍费尔 诺贝特·米勒 卡拉·雷克 克里斯蒂娜·韦伯 格萨·塔拉托拉 大卫-拉斐尔· 于 2018-09-04 设计创作，主要内容包括：本发明涉及一种硫可交联的橡胶混合物、其硫化橡胶、以及车辆轮胎。所述硫可交联的橡胶混合物含有至少以下成分：-至少一种二烯橡胶；以及-10phr至300phr的至少一种二氧化硅；以及-1phf至30phf的至少一种硅烷A,其具有经验通式A-I)和/或A-XI)A-I)(R<Sup>1</Sup>)<Sub>o</Sub>Si-R<Sup>2</Sup>-(S-R<Sup>3</Sup>)<Sub>q</Sub>-S<Sub>x</Sub>-(R<Sup>3</Sup>-S)<Sub>q</Sub>-R<Sup>2</Sup>-Si(R<Sup>1</Sup>)<Sub>o</Sub>；A-XI)(R<Sup>1</Sup>)<Sub>o</Sub>Si-R<Sup>2</Sup>-(S-R<Sup>3</Sup>)<Sub>s</Sub>-S-X；以及-0.5phf至30phf的至少一种硅烷B,其具有经验通式B-I)B-I)(R<Sup>1</Sup>)<Sub>o</Sub>Si-R<Sup>4</Sup>-S-R<Sup>4</Sup>-Si(R<Sup>1</Sup>)<Sub>o</Sub>其中x是从2至10的整数,q是1、2或3并且s是0、1、2或3,并且X是氢原子或-C(＝O)-R<Sup>8</Sup>基团,其中R<Sup>8</Sup>选自氢、C<Sub>1</Sub>-C<Sub>20</Sub>-烷基、C<Sub>6</Sub>-C<Sub>20</Sub>-芳基、C<Sub>2</Sub>-C<Sub>20</Sub>-烯基和C<Sub>7</Sub>-C<Sub>20</Sub>-芳烷基。(The invention relates to a sulfur-crosslinkable rubber mixture, a vulcanized rubber thereof, and a vehicle tire. The sulfur-crosslinkable rubber mixture contains at least the following components: -at least one diene rubber; and-10 phr to 300phr of at least one silica; and-1 phf to 30phf of at least one silane A of empirical formula A-I) and/or A-XI) A-I) (R 1 ) o Si‑R 2 ‑(S‑R 3 ) q ‑S x ‑(R 3 ‑S) q ‑R 2 ‑Si(R 1 ) o ；A‑XI)(R 1 ) o Si‑R 2 ‑(S‑R 3 ) s -S-X; and-0.5 phf to 30phf of at least one silane B of empirical formula B-I) B-I) (R 1 ) o Si‑R 4 ‑S‑R 4 ‑Si(R 1 ) o Wherein X is an integer from 2 to 10, q is 1,2 or 3 and s is 0, 1,2 or 3, and X is a hydrogen atom or-C (═ O) -R 8 Group, wherein R 8 Selected from hydrogen, C 1 ‑C 20 Alkyl radical, C 6 ‑C 20 -aryl, C 2 ‑C 20 -alkenyl and C 7 ‑C 20 -an aralkyl group.)
1. A sulfur-crosslinkable rubber mixture comprising at least the following components:
-at least one diene rubber; and
-from 10phr to 300phr of at least one silica; and
-1phf to 30phf of at least one silane A of empirical formula A-I) and/or A-XI)
A-I)(R1)oSi-R2-(S-R3)q-Sx-(R3-S)q-R2-Si(R1)o；
A-XI)(R1)oSi-R2-(S-R3)s-S-X; and
0.5phf to 30phf of at least one silane B of empirical formula B-I)
B-I)(R1)oSi-R4-S-R4-Si(R1)o
Wherein o may be 1 or 2 or 3, and the radical R1May be the same or different and is selected from C1-C10-alkoxy, C6-C20-phenoxy group, C2-C10-cyclic dialkoxy, C2-C10Di-alkoxy, C4-C10Cycloalkoxy, C6-C20-aryl, C1-C10Alkyl radical, C2-C20-alkenyl, C2-C20-alkynyl, C7-C20Aralkyl, halide or
Alkyl polyether radical-O- (R)6-O)r-R7Wherein the radical R6Identical or different and branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C1-C30A hydrocarbon radical, R is an integer from 1 to 30, and the radical R7Is an unsubstituted or substituted, branched or unbranched, monovalent alkyl, alkenyl, aryl or aralkyl radical, or
Two R1Corresponds to a dialkoxy radical having 2 to 10 carbon atoms, where in this case o<3，
Or two or more silanes of the formulae A-I) and/or A-XI) and/or B-I) may be present via the radical R1Or bridged by condensation; and is
With the proviso that in each of the formulae A-I) and A-XI) and B-I) (R1)oIn the Si group, at least one R1Selected from the above options, wherein R is1: i) bonded to a silicon atom via an oxygen atom, or ii) is a halide; and is
Wherein each molecule neutralizes the intramolecular radical R2、R3And R4May be identical or different and are branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C1-C30A hydrocarbyl group; and wherein x is an integer from 2 to 10, and q is 1 or 2 or 3; and wherein s is 0 or 1 or 2 or 3; and X is a hydrogen atom or-C (═ O) -R8Group, wherein R8Selected from hydrogen, C1-C20Alkyl radical, C6-C20-aryl, C2-C20-alkenyl and C7-C20-an aralkyl group.
2. A sulfur-crosslinkable rubber composition according to claim 1, wherein q is 1.
3. A sulfur-crosslinkable rubber composition according to any one of the preceding claims, wherein s is 0 or 1.
4. Sulfur-crosslinkable rubber mixture according to any one of the preceding claims, characterized in that R3Is an alkyl group having 4 to 8 carbon atoms.
5. Sulfur-crosslinkable rubber mixture according to any one of the preceding claims, characterized in that R4Is an alkyl group having 2 to 6 carbon atoms.
6. A sulfur-crosslinkable rubber mixture according to any one of the preceding claims, characterized in that the silane a-I has the following structure according to formula a-II):
A-II)
wherein x is an integer from 2 to 10.
7. A sulfur-crosslinkable rubber compound according to any one of the preceding claims, characterized in that k is an integer from 2 to 4, preferably 2.
8. Sulfur-crosslinkable rubber mixture according to any one of the preceding claims, characterized in that X is an alkanoyl group having 1 to 10 carbon atoms.
9. A sulfur-crosslinkable rubber mixture according to any one of the preceding claims, characterized in that the silane a-XI) has the following structure according to formula a-XII):
A-XII)(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-CH3。
10. sulfur-crosslinkable rubber mixture according to any one of the preceding claims, characterized in that the silane a-XI) has the following structure according to the formula a-XIII):
A-XIII)(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-(CH2)6-CH3。
11. a sulfur-crosslinkable rubber mixture according to any one of the preceding claims, characterized in that the silane a-XI) has the following structure according to formula a-XIV):
A-XIV)(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-(CH2)16-CH3。
12. a sulfur-crosslinkable rubber mixture according to any one of the preceding claims, characterized in that the silane a-XI) has the following structure according to the formula a-XV):
A-XV)(EtO)3Si-(CH2)3-S-C(＝O)-(CH2)16-CH3。
13. sulfur-crosslinkable rubber mixture according to any one of the preceding claims, characterized in that the silane B has the following structure according to the formula B-II):
B-II)(EtO)3Si-(CH2)3-S-(CH2)3-Si(OEt)3。
14. a vulcanized rubber obtained by sulfur vulcanization of at least one rubber mixture according to any one of claims 1 to 13.
15. A vehicle tyre, characterized in that it comprises at least one vulcanized rubber according to claim 14 in at least one component part, preferably in the tread.
Technical Field
The invention relates to a sulfur-crosslinkable rubber mixture, to a vulcanized rubber thereof, and to a vehicle tire.
Background
The rubber composition of the tread determines to a large extent the driving characteristics of vehicle tires, in particular pneumatic vehicle tires.
Likewise, rubber mixtures, which are used in particular in drive belts and other belts and in mechanically stressed parts of hoses, play an important role in the stability and life of these rubber articles. Therefore, high demands are placed on these rubber mixtures for pneumatic vehicle tires, belts (including transmission belts) and hoses.
There are conflicts between most known tire characteristics, such as wet grip behavior, dry braking, handling behavior, rolling resistance, winter characteristics, wear behavior, and tear characteristics.
In particular in pneumatic vehicle tires, many attempts have been made, in particular in tread mixtures, to positively influence the properties of the tire by modifying the polymer components, fillers and other additives.
It must be noted that an improvement in one tire characteristic often entails a deterioration in another characteristic.
In a given mixture system, for example, there are various known options for optimizing the handling behavior by increasing the stiffness of the rubber mixture. Mention may be made here, for example, of increasing the filler level and increasing the crosslink density of the vulcanized rubber mixtures. Although increasing the filler content brings about disadvantages in terms of rolling resistance, the reinforcing network leads to a deterioration of the tear properties and wet grip performance of the rubber mixtures.
It is also known that rubber mixtures, in particular for treads for pneumatic vehicle tires, may contain silica as filler. It is also known that advantages are obtained in terms of the rolling resistance behavior and the processability of the rubber mixtures when silica is bonded to one or more polymers by means of silane coupling agents.
Silane coupling agents known from the prior art are disclosed, for example, in DE 2536674C3 and DE 2255577C 3.
It is possible in principle to distinguish silanes which are bonded only to silica or equivalent fillers, and to this end in particular silanes which comprise at least one silyl group and, in addition to the silyl group, also a reactive sulfur moiety, such as, in particular, SxMoiety (wherein x>Or equal to 2) or mercapto groups S-H or block S-PG moieties (in which PG represents a protecting group) such that, after removal of the protecting group during sulfur vulcanization, there is a passage through SxOr S-H moieties or S-PG moieties, alsoCan be bonded to a polymer.
In some cases, the prior art also discloses combinations of selected silanes.
EP 1085045B 1 discloses a rubber mixture containing a combination of polysulphide silanes (a mixture having a disulphide content of 69 to 79% by weight, a trisulphide content of 21 to 31% by weight and a tetrasulphide content of 0 to 8% by weight) and silanes containing only one sulphur atom and therefore being unable to bond to a polymer. When used in the tread of a vehicle tyre, such a silane mixture makes it possible, in combination with carbon black and silica as fillers, to obtain an optimum distribution of properties in terms of laboratory prediction, in particular rolling resistance and wear, and optimum tyre characteristics.
WO 2012092062 discloses the combination of a blocked mercaptosilane (NXT) with a filler reinforcing silane comprising non-reactive alkyl groups between silyl groups.
Disclosure of Invention
The problem addressed by the present invention was therefore to provide a rubber mixture which exhibits an improvement in hysteresis behavior and tear behavior compared with the prior art. At the same time, other physical properties of the rubber mixtures used in tires should not be negatively affected or should even be likewise improved. In particular, the rubber mixtures should have comparable hardness levels.
This problem is solved by a rubber mixture comprising the following components:
-at least one diene rubber; and
-from 10phr to 300phr of at least one silica; and
-1phf to 30phf of at least one silane A of empirical formula A-I) and/or A-XI)
A-I)(R1)oSi-R2-(S-R3)q-Sx-(R3-S)q-R2-Si(R1)o；
A-XI)(R1)oSi-R2-(S-R3)s-S-X; and-0.5 phf to 30phf of at least one silane B of empirical formula B-I)
B-I)(R1)oSi-R4-S-R4-Si(R1)o
Wherein o may be 1 or 2 or 3, and the radical R1May be the same or different and is selected from C1-C10-alkoxy, C6-C20-phenoxy group, C2-C10-cyclic dialkoxy, C2-C10Di-alkoxy, C4-C10Cycloalkoxy, C6-C20-aryl, C1-C10Alkyl radical, C2-C20-alkenyl, C2-C20-alkynyl, C7-C20Aralkyl, halide or
Alkyl polyether radical-O- (R)6-O)r-R7Wherein the radical R6Identical or different and branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C1-C30A hydrocarbon radical, R is an integer from 1 to 30, and the radical R7Is an unsubstituted or substituted, branched or unbranched, monovalent alkyl, alkenyl, aryl or aralkyl radical, or
Two R1Corresponds to a dialkoxy radical having 2 to 10 carbon atoms, where in this case o<3，
Or two or more silanes of the formulae A-I) and/or A-XI) and/or B-I) may be present via the radical R1Or bridged by condensation; and is
With the proviso that in each of the formulae A-I) and A-XI) and B-I) (R1)oIn the Si group, at least one R1Selected from the above options, wherein R is1: i) bonded to a silicon atom via an oxygen atom, or ii) is a halide; and is
Wherein each molecule neutralizes the intramolecular radical R2、R3And R4May be identical or different and are branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C1-C30A hydrocarbyl group; and wherein x is an integer from 2 to 10And q is 1 or 2 or 3; and wherein s is 0 or 1 or 2 or 3; and X is a hydrogen atom or-C (═ O) -R8Group, wherein R8Selected from hydrogen, C1-C20Alkyl radical, C6-C20-aryl, C2-C20-alkenyl and C7-C20-an aralkyl group.
It has now been found, surprisingly, that combinations of silanes A and B (where silane A can also be due to polysulfide S)xGroups or reactive S-X groups bonded to the polymer) achieve an improvement in hysteresis behavior and tear properties in combination with a comparable hardness of the rubber mixtures according to the invention. This effect also occurs unexpectedly when a portion of silane a is replaced by silane B.
The invention further provides at least one vulcanized rubber of the rubber mixture according to the invention.
The invention further provides a vehicle tire comprising at least one vulcanized rubber according to the invention of a rubber mixture according to the invention in at least one component part. It is preferred that the vehicle tyre comprises at least one vulcanized rubber at least in the tread.
The vulcanized rubber according to the invention and the vehicle tyre according to the invention are characterized by an optimum rolling resistance behaviour and a longer structural durability under stress.
In the case of a two-part tread (upper: crown and lower: base), the rubber mixtures according to the invention can be used both for the crown and for the base. Preference is given to vulcanizates according to the invention in which at least the crown or at least the base or at least the crown and the base comprise at least one rubber mixture according to the invention.
In the context of the present invention, vehicle tires are understood to mean pneumatic vehicle tires and solid rubber tires, including tires for industrial and construction site vehicles, HGV tires, passenger car tires and bicycles, and motorcycle tires.
The rubber mixtures according to the invention are furthermore also suitable for other components of vehicle tires, such as in particular flange profiles, and also for internal tire components. The rubber mixtures according to the invention are further suitable for other industrial rubber articles, such as bellows, conveyor belts, air springs, belts (including drive belts) or hoses, and shoe soles.
The composition of the sulfur-crosslinkable rubber mixture according to the invention will be described in more detail hereinafter. All statements also apply to the vulcanizates according to the invention and to the vehicle tires according to the invention which comprise at least one vulcanizate according to the invention of the rubber mixtures according to the invention in at least one component part.
The unit "phr" (parts per hundred parts of rubber by weight) used in this document is the unit of quantity customary for the formulation of mixtures in the rubber industry. In this document, the dosage of parts by weight of the various substances is 100 parts by weight, based on the total mass of all the rubbers present in the mixture having a molecular weight M of more than 20000 g/molw(GPC)。
The unit phf (parts per hundred parts filler by weight) used in this document is the unit of the customary quantity of coupling agent for fillers in the rubber industry.
In the context of the present application phf relates to the silica present, i.e. any other filler (such as carbon black) that may be present is not included in the calculation of the amount of silane.
According to the invention, the rubber mixture is sulfur-crosslinkable and contains for this purpose at least one diene rubber.
Diene rubbers are understood to mean rubbers which are formed by polymerization or copolymerization of dienes and/or cycloolefins and thus contain C ═ C double bonds in the main chain or in side groups.
The diene rubber is preferably selected from the group consisting of: natural polyisoprene and/or synthetic polyisoprene and/or epoxidized polyisoprene and/or butadiene rubber and/or butadiene-isoprene rubber and/or solution polymerized styrene-butadiene rubber and/or emulsion polymerized styrene-butadiene rubber and/or styrene-isoprene rubber and/or liquid rubber (having a molecular weight M of more than 20000 g/mol)w) And/or halobutyl rubber and/or polynorbornene and/or isopreneDiene-isobutylene copolymer and/or ethylene-propylene-diene rubber and/or nitrile rubber and/or chloroprene rubber and/or acrylate rubber and/or fluoro rubber and/or silicone rubber and/or polysulfide rubber and/or epichlorohydrin rubber and/or styrene-isoprene-butadiene terpolymer and/or hydrogenated acrylonitrile-butadiene rubber and/or hydrogenated styrene-butadiene rubber.
In particular, nitrile rubber, hydrogenated acrylonitrile-butadiene rubber, neoprene rubber, butyl rubber, halobutyl rubber or ethylene-propylene-diene rubber are employed in the production of industrial rubber articles such as belts (including power transmission belts) and hoses and/or shoe soles. For these rubbers, it is preferred to use mixture formulations known to the person skilled in the art, and in particular in respect of fillers, plasticizers, vulcanization systems and additives.
The rubber mixtures are particularly suitable for vehicle tires, in particular and in principle can be used in any component parts, such as in particular treads, sidewalls, flange profiles, and also in other so-called body parts.
Preferably the diene rubber is selected from the group consisting of: natural polyisoprene (NR), synthetic polyisoprene (IR), Butadiene Rubber (BR), solution polymerized styrene-butadiene rubber (SSBR), emulsion polymerized styrene-butadiene rubber (ESBR), butyl rubber (IIR), and halobutyl rubber.
In a particularly preferred embodiment of the invention, the diene rubber is 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). The rubber mixtures are particularly suitable for treads for vehicle tires.
In a particularly advantageous embodiment of the invention, the rubber mixture contains at least one natural polyisoprene, preferably in an amount of from 2phr to 100phr, and in a particularly advantageous embodiment of the invention in an amount of from 5phr to 30phr, very particularly preferably in an amount of from 5phr to 15 phr. This achieves a particularly good processability of the rubber mixtures according to the invention.
In a particularly advantageous embodiment of the invention, the rubber mixture contains at least one polybutadiene (butadiene rubber), preferably in an amount of from 2phr to 100phr, and according to a particularly advantageous embodiment of the invention in an amount of from 5phr to 50phr, very particularly preferably from 10phr to 25 phr. This achieves particularly good wear and tear properties and good processability, as well as low hysteresis losses of the rubber mixtures according to the invention.
In a particularly advantageous embodiment of the invention, the rubber mixture contains at least one styrene-butadiene rubber (SBR) in an amount of preferably from 2phr to 100phr, and in a particularly advantageous embodiment of the invention in an amount of from 25phr to 80phr, very particularly preferably from 65phr to 85 phr. This achieves good processability and low hysteresis losses of the rubber mixtures according to the invention and also good wear and tear properties.
Here, the SBR is preferably an SSBR, which yields the best hysteresis properties.
In a particularly advantageous embodiment of the invention, the rubber mixture contains the polymer blends of the named rubbers NR, BR and SBR, preferably SSBR, preferably in the amounts named in each case in any possible combination, with the sum of all rubbers present being 100 phr.
In a particularly advantageous embodiment, the rubber mixture contains from 5phr to 30phr of at least one natural polyisoprene and/or at least one synthetic polyisoprene, and from 25phr to 80phr of at least one styrene-butadiene rubber and from 5phr to 50phr of at least one butadiene rubber.
The natural polyisoprene and/or the synthetic polyisoprene in all examples may be cis-1, 4-polyisoprene or 3, 4-polyisoprene. However, it is preferred to use cis-1, 4-polyisoprene having a cis-1, 4 content of > 90% by weight. First, such polyisoprenes can be obtained by stereospecific polymerization in solution using a Ziegler-Natta (Ziegler-Natta) catalyst or using finely divided alkyllithium. Secondly, Natural Rubber (NR) is cis-1, 4-polyisoprene of this type, wherein the cis-1, 4 content in natural rubber is more than 99% by weight.
Mixtures of one or more natural polyisoprenes with one or more synthetic polyisoprenes are also conceivable.
These include, inter alia, the so-called high cis type and the low cis type, wherein polybutadiene having a cis content of not less than 90% by weight is referred to as high cis type and polybutadiene having a cis content of less than 90% by weight is referred to as low cis type an example of low cis polybutadiene is L i-BR (lithium-catalyzed butadiene rubber) having a cis content of 20 to 50% by weight, high cis BR achieving particularly good wear characteristics and low hysteresis of the rubber mixture.
The polybutadiene or polybutadienes employed may be end-group modified and/or functionalized by modification and functionalization along the polymer chain. The modification can be with hydroxyl and/or ethoxy and/or epoxy and/or siloxane groups and/or amino and/or aminosiloxane and/or carboxyl and/or phthalocyanine groups and/or silyl sulfide groups. However, further modifications, also referred to as functionalisation, known to the person skilled in the art are also suitable. Such functionalization may comprise a metal atom as a constituent.
In the case where at least one styrene-butadiene rubber (styrene-butadiene copolymer) is present in the rubber mixture, it may be a solution-polymerized styrene-butadiene rubber (SSBR) or an emulsion-polymerized styrene-butadiene rubber (ESBR), and a mixture of at least one SSBR and at least one ESBR may also be employed. The terms "styrene-butadiene rubber" and "styrene-butadiene copolymer" are used synonymously in the context of the present invention.
The styrene-butadiene copolymer employed may be end-group modified and/or functionalized along the polymer chain with the modifications and functionalizations listed above for polybutadiene.
According to the invention, the rubber mixture contains from 10phr to 300phr of at least one silica.
The silica may be selected from the silica types known to those skilled in the art and suitable as fillers for tire rubber compounds. However, it is particularly preferred to use a composition having a particle size of 35 to 400m2A/g, preferably from 35 to 350m2Per g, particularly preferably from 85 to 320m2Per g and very particularly preferably from 120 to 235m2Nitrogen surface area (BET surface area) in g (according to DIN ISO9277 and DIN 66132) and from 30 to 400m2A/g, preferably from 30 to 330m2Per g, particularly preferably from 80 to 300m2G and very particularly preferably from 110 to 230m2Finely divided, precipitated silica of CTAB surface area (according to ASTM D3765) per g. Such silicas give rise, for example, to particularly good physical properties of vulcanizates in rubber mixtures for tire treads. Advantages are also obtained in the processing of the mixture due to the reduction of the mixing time, while maintaining the same product characteristics resulting in improved productivity. The silicas used therefore include, for example, those from EvonikSilicas of the type VN3 (trade name) or highly dispersible so-called HD silicas (for example from Suwei corporation (Solvay))1165MP)。
In a preferred embodiment of the invention, the rubber mixtures according to the invention contain from 20phr to 300phr, preferably from 30phr to 250phr, particularly preferably from 30phr to 150phr and very particularly preferably from 80phr to 110phr, of at least one silica.
In particular, a relatively high silica content of up to 300phr or 250phr or 150phr or 110phr in combination with the two listed silanes A and B, which are described in more detail below, leads to advantageous properties, in particular optimum hysteresis properties and improved tear properties at the same hardness, in particular in terms of the tire properties of the rubber mixtures and their vulcanizates.
In the case of the presence of at least two different silicas (for example differing in their BET surface area) in the rubber mixtures according to the invention, the amounts listed are always related to the total amount of all silicas present.
The rubber mixtures according to the invention may further contain at least one carbon black, in particular industrial carbon black.
Suitable carbon blacks include all carbon black types known to those skilled in the art.
In one embodiment, the carbon black has an iodine value according to ASTM D1510 (also known as iodine adsorption value) of between 30 and 250g/kg, preferably 30 to 180g/kg, particularly preferably 40 to 180g/kg, and very particularly preferably 40 to 130g/kg, and has a DBP value according to ASTM D2414 of 30 to 200ml/100g, preferably 70 to 200ml/100g, particularly preferably 90 to 200ml/100 g.
The specific absorption volume of carbon black or light weight filler was determined using dibutyl phthalate according to the DBP value of ASTM D2414.
The use of carbon black of this type in rubber mixtures, in particular for vehicle tires, ensures the greatest possible compromise between abrasion resistance and heat build-up, which in turn affects the ecologically relevant rolling resistance. It is preferred to use only one type of carbon black in a particular rubber mixture, but it is also possible to incorporate different types of carbon black into the rubber mixture. However, the total amount of carbon black present is preferably from 0phr to 250 phr.
In an advantageous embodiment of the invention, the rubber mixture contains from 0phr to 20phr, preferably from 0phr to 10phr, of at least one carbon black and from 30phr to 300phr, preferably from 30phr to 200phr, of at least one silica.
In another advantageous embodiment of the invention, the rubber mixture contains from 30phr to 150phr of at least one carbon black, and from 10phr to 30phr of at least one silica, and thus constitutes part of the silica mixture.
The rubber mixtures according to the invention may preferably contain the smallest possible amount of further fillers, i.e. preferably from 0phr to 20phr, particularly preferably from 0phr to 10 phr. In the context of the present invention, additional (non-reinforcing) fillers include aluminosilicates, kaolin, chalk, starch, magnesium oxide, titanium dioxide or rubber gels and also fibers (e.g. aramid fibers, glass fibers, carbon fibers, cellulose fibers).
Further optional reinforcing fillers include, for example, carbon nanotubes ((CNTs), including discrete CNTs, so-called Hollow Carbon Fibers (HCF) and modified CNTs containing one or more functional groups such as hydroxyl, carboxyl and carbonyl), graphite and graphene, and so-called "carbon-silica dual-phase fillers".
In the context of the present invention, zinc oxide is not included in the filler.
According to the invention, the rubber mixtures contain 1phf to 30phf, preferably 2phf to 20phf, particularly preferably 2phf to 10phf, at least one silane A) of the empirical formula A-I) and/or A-XI)
A-I)(R1)oSi-R2-(S-R3)q-Sx-(R3-S)q-R2-Si(R1)o；
A-XI)(R1)oSi-R2-(S-R3)s-S-X，
And 0.5phf to 30phf, preferably 0.5phf to 20phf, particularly preferably 1phf to 10phf, of at least one silane B) of the empirical formula B-I)
B-I)(R1)oSi-R4-S-R4-Si(R1)o，
Wherein o may be 1 or 2 or 3, and the radical R1May be the same or different and is selected from C1-C10-alkoxy, C6-C20-phenoxy group, C2-C10-cyclic dialkoxy, C2-C10Di-alkoxy radical, C4-C10Cycloalkoxy, C6-C20-aryl, C1-C10Alkyl radical, C2-C20-alkenyl, C2-C20-alkynyl, C7-C20Aralkyl, halide or
Alkyl polyether radical-O- (R)6-O)r-R7Wherein the radical R6Is the same as orDifferent and branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C1-C30A hydrocarbon radical, R is an integer from 1 to 30, and the radical R7Is an unsubstituted or substituted, branched or unbranched, monovalent alkyl, alkenyl, aryl or aralkyl radical, or
Two R1Corresponding to a dialkoxy radical having 2 to 10 carbon atoms, wherein then o<3(o is less than 3),
or two or more silanes of the formulae A-I) and/or A-XI) and/or B-I) may be present via the radical R1Or bridged by condensation; and is
With the proviso that in each of the formulae A-I) and A-XI) and B-I) (R1)oIn the Si group, at least one R1Selected from the above options, wherein R is1: i) bonded to a silicon atom via an oxygen atom, or ii) is a halide; and is
Wherein each molecule neutralizes the intramolecular radical R2、R3And R4May be identical or different and are branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C1-C30A hydrocarbyl group; and wherein x is an integer from 2 to 10, and q is 1 or 2 or 3; and wherein s is 0 or 1 or 2 or 3; and X is a hydrogen atom or-C (═ O) -R8Group, wherein R8Selected from hydrogen, C1-C20Alkyl radical, C6-C20-aryl, C2-C20-alkenyl and C7-C20-an aralkyl group.
The at least one silane a present according to the invention is due to the fact that the S-X moiety (silane a-XI)) is formed by elimination of X (i.e. a hydrogen atom or-C (═ O) -R)8Groups) silanes which can be bonded to polymers, or by SxA group (silane A-I) and since X is at least 2, a sulfur group S may be usedxA silane bonded to the polymer.
In each individual molecule, x is an integer from 2 to 8, and mixtures of different molecules with different values of x may also be present.
It is preferred when x is 2 to 4. In a particularly advantageous embodiment of the invention, x is 2.
Different silanes with different groups X may also be present in a mixture.
X is a hydrogen atom or-C (═ O) -R8Group, wherein R8Selected from hydrogen, C1-C20Alkyl, preferably C1-C17，
C6-C20-an aryl group, preferably a phenyl group,
C2-C20-alkenyl and C7-C20-aralkyl.
Preferably, X is-C (═ O) -R8When radical, wherein R8Particularly preferably C1-C20-an alkyl group; thus, in this case, X is alkanoyl.
Very particular preference is given to when X is alkanoyl having a total of from 1 to 10 carbon atoms.
In an advantageous embodiment, the alkanoyl group has a total of 1 to 3 carbon atoms, in particular 2 carbon atoms.
In another advantageous embodiment, the alkanoyl group has a total of 7 to 9 carbon atoms, especially 8 carbon atoms.
The index q may take the value 1 or 2 or 3. It is preferred when q is 1.
The index s may take the value 0 or 1 or 2 or 3. It is preferred when s is 0 or 1.
The silanes B present according to the invention have only one sulfur atom and are therefore unable to bond to the polymer.
The following relates to R1、R2、R3And R4The statements in (A) apply to the extent present in the molecule to the silanes according to the formulae A-I), A-XI) and B-I) and unless otherwise stated.
R2、R3And R4May be, in particular and preferably, -CH2-、-CH2CH2-、-CH2CH2CH2-、-CH2CH2CH2CH2-、-CH(CH3)-、-CH2CH(CH3)-、-CH(CH3)CH2-、-C(CH3)2-、-CH(C2H5)-，-CH2CH2CH(CH3)-、-CH(CH3)CH2CH2-、-CH2CH(CH3)CH2-、-CH2CH2CH2CH2CH2-，-CH2CH2CH2CH2CH2CH2-、-CH2CH2CH2CH2CH2CH2CH2-，-CH2CH2CH2CH2CH2CH2CH2CH2-、-CH2CH2CH2CH2CH2CH2CH2CH2CH2-，-CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2-，-CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2-，-CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2-，-CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2-，-CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2CH2-
Or (2).
R2Preference is given to alkyl having 2 or 3 carbon atoms, and particular preference to-CH2CH2-or-CH2CH2CH2-, particularly preferably-CH2CH2CH2-。
R3Preferably, it isAlkyl having 4 to 8 carbon atoms, and-CH is particularly preferred2CH2CH2CH2CH2-、-CH2CH2CH2CH2CH2CH2-、-CH2CH2CH2CH2CH2CH2CH2-、-CH2CH2CH2CH2CH2CH2CH2CH2-, particularly preferably-CH2CH2CH2CH2CH2CH2-。
R4Preferred is an alkyl group having 2 to 10 carbon atoms (further preferably 2 to 6 carbon atoms, and particularly preferably 2 or 3 carbon atoms), preferably-CH2CH2-or-CH2CH2CH2-, particularly preferably-CH2CH2CH2-。
All radicals R enumerated1And via the radical R1The bridging silane or silanes may be combined with each other within the silyl group.
In which two R are1Corresponding to a dialkoxy radical having 2 to 10 carbon atoms and then o<In the case of 3(o is less than 3), the silicon atom is part of a ring system.
In the case where two silanes of the formulae A-I) and/or A-XI) and/or B-I) are bridged to one another, they share the group R1Or by two Si-R1The combination of groups are linked to each other via an oxygen atom. This also allows more than two silanes to be attached to each other. After synthesis of the silanes of the formulae A-I) and/or A-XI) and/or B-I), it is thus conceivable for the two silanes of the formulae A-I) and/or A-XI) and/or B-I) to be present via an oxygen atom or a radical R1Are bridged to each other. This also allows more than two silanes to be attached to each other, for example via a dialkoxy group.
The rubber mixtures according to the invention may therefore also contain oligomers formed by hydrolysis and condensation or by bridging via dialkoxy groups, R as silanes A and/or B (silanes of the formulae A-I) and/or A-XI) and/or B-I)1。
Therefore, the premise isIs in the formulae A-I) and A-XI) and B-I), in each (R)1)oIn the Si group, at least one R1Selected from the above options, wherein R is1: i) bonded to the silicon atom via an oxygen atom, or ii) is a halide, the silanes of the formulae A-I) and A-XI) and B-I) each comprising at least one group R which can act as a leaving group1。
These are therefore in particular alkoxy groups, phenoxy groups or any other radicals listed which are bonded to the silicon atom via an oxygen atom, or halides.
Preference is given to the radical R1Containing an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms or a halide ion, particularly preferably an alkoxy group having 1 to 6 carbon atoms.
In a particularly advantageous embodiment of the invention, in the silyl radical (R)1)oRadical R in Si-1Identical and are alkoxy having 1 or 2 carbon atoms, i.e. methoxy or ethoxy, very particularly preferably ethoxy, where o is 3.
However, in the case of oligomers or in which two R are present1In the case of formation of dialkoxy radicals, the remaining radicals R1Preference is given to alkyl having 1 to 6 carbon atoms or halides or alkoxy having 1 to 6 carbon atoms, preferably 1 or 2 carbon atoms, i.e. methoxy or ethoxy, very particularly preferably ethoxy.
In the context of the present invention, ethoxy groups in the formula of silanes are abbreviated EtO or OEt. Both symbols indicate that alkoxy groups (like ethoxy groups) are bonded to the silicon atom Si via the oxygen atom O.
However, the abbreviations OEt and EtO may in principle be used synonymously in the context of the present invention.
Silanes a of the formula a-I) may preferably be:
(EtO)3Si-CH2-S2-CH2-Si(OEt)3、(EtO)3Si-(CH2)2-S2-(CH2)2-Si(OEt)3、(EtO)3Si-(CH2)3-S2-(CH2)3-Si(OEt)3、(EtO)3Si-(CH2)6-S2-(CH2)6-Si(OEt)3、(EtO)3Si-(CH2)8-S2-(CH2)8-Si(OEt)3、(EtO)3Si-(CH2)12-S2-(CH2)12-Si(OEt)3、(EtO)3Si-CH2-S4-CH2-Si(OEt)3、(EtO)3Si-(CH2)2-S4-(CH2)2-Si(OEt)3、(EtO)3Si-(CH2)3-S4-(CH2)3-Si(OEt)3、(EtO)3Si-CH2-S-(CH2)-S2-(CH2)-S-CH2-Si(OEt)3、(EtO)3Si-(CH2)2-S-(CH2)-S2-(CH2)-S-(CH2)2-Si(OEt)3、(EtO)3Si-(CH2)3-S-(CH2)-S2-(CH2)-S-(CH2)3-Si(OEt)3、(EtO)3Si-CH2-S-(CH2)2-S2-(CH2)2-S-CH2-Si(OEt)3、(EtO)3Si-(CH2)2-S-(CH2)2-S2-(CH2)2-S-(CH2)2-Si(OEt)3、(EtO)3Si-(CH2)3-S-(CH2)2-S2-(CH2)2-S-(CH2)3-Si(OEt)3、(EtO)3Si-CH2-S-(CH2)3-S2-(CH2)3-S-CH2-Si(OEt)3、(EtO)3Si-(CH2)2-S-(CH2)3-S2-(CH2)3-S-(CH2)2-Si(OEt)3、(EtO)3Si-(CH2)3-S-(CH2)3-S2-(CH2)3-S-(CH2)3-Si(OEt)3、(EtO)3Si-CH2-S-(CH2)4-S2-(CH2)4-S-CH2-Si(OEt)3、(EtO)3Si-(CH2)2-S-(CH2)4-S2-(CH2)4-S-(CH2)2-Si(OEt)3、(EtO)3Si-(CH2)3-S-(CH2)4-S2-(CH2)4-S-(CH2)3-Si(OEt)3、(EtO)3Si-CH2-S-(CH2)5-S2-(CH2)5-S-CH2-Si(OEt)3、(EtO)3Si-(CH2)2-S-(CH2)5-S2-(CH2)5-S-(CH2)2-Si(OEt)3、(EtO)3Si-(CH2)3-S-(CH2)5-S2-(CH2)5-S-(CH2)3-Si(OEt)3、(EtO)3Si-CH2-S-(CH2)6-S2-(CH2)6-S-CH2-Si(OEt)3、(EtO)3Si-(CH2)2-S-(CH2)6-S2-(CH2)6-S-(CH2)2-Si(OEt)3、(EtO)3Si-(CH2)3-S-(CH2)6-S2-(CH2)6-S-(CH2)3-Si(OEt)3。
in a preferred embodiment of the invention, the silane a having the variant of the formula a-I) has the following structure according to the formula a-II):
A-II)
wherein x is an integer from 2 to 10.
Silanes A of the formulae A to II) achieve particularly good hysteresis behavior and optimized tear properties.
In a particularly advantageous embodiment of the invention, an optimized hysteresis behavior and thus an optimized rolling resistance predictor and a very good wear behavior are particularly produced, preferably when x is 2.
In this example, the silane has the formula (EtO)3Si-(CH2)3-S-(CH2)6-S2-(CH2)6-S-(CH2)3-Si(OEt)3。
Mixtures of at least two silanes of the formula a-II) with different numbers of sulfur atoms (x ═ 2 or 3 or 4 or 5 or 6 or 7 or 8) may also be present, where each possible combination is conceivable, and monosulfides (where x ═ 1) may additionally be present in each mixture.
Silanes A of the formulae A to XI) may preferably be:
(EtO)3Si-(CH2)3-S-C(＝O)-CH3、(EtO)3Si-(CH2)3-S-C(＝O)-C2H5、(EtO)3Si-(CH2)3-S-C(＝O)-C3H7、(EtO)3Si-(CH2)3-S-C(＝O)-C4H9、(EtO)3Si-(CH2)3-S-C(＝O)-C5H11、(EtO)3Si-(CH2)3-S-C(＝O)-C6H13、(EtO)3Si-(CH2)3-S-C(＝O)-C7H15、(EtO)3Si-(CH2)3-S-C(＝O)-C9H19、(EtO)3Si-(CH2)3-S-C(＝O)-C11H23、(EtO)3Si-(CH2)3-S-C(＝O)-C13H27,(EtO)3Si-(CH2)3-S-C(＝O)-C15H31、(EtO)3Si-(CH2)3-S-C(＝O)-C17H35、(EtO)3Si-(CH2)3-S-(CH2)-S-C(＝O)-CH3、(EtO)3Si-(CH2)3-S-(CH2)-S-C(＝O)-C2H5，(EtO)3Si-(CH2)3-S-(CH2)-S-C(＝O)-C3H7、(EtO)3Si-(CH2)3-S-(CH2)-S-C(＝O)-C4H9，(EtO)3Si-(CH2)3-S-(CH2)-S-C(＝O)-C5H11、(EtO)3Si-(CH2)3-S-(CH2)-S-C(＝O)-C6H13，(EtO)3Si-(CH2)3-S-(CH2)-S-C(＝O)-C7H15、(EtO)3Si-(CH2)3-S-(CH2)-S-C(＝O)-C9H19，(EtO)3Si-(CH2)3-S-(CH2)-S-C(＝O)-C11H23、(EtO)3Si-(CH2)3-S-(CH2)-S-C(＝O)-C13H27，(EtO)3Si-(CH2)3-S-(CH2)-S-C(＝O)-C15H31、(EtO)3Si-(CH2)3-S-(CH2)-S-C(＝O)-C17H35，(EtO)3Si-(CH2)3-S-(CH2)2-S-C(＝O)-CH3、(EtO)3Si-(CH2)3-S-(CH2)2-S-C(＝O)-C2H5，(EtO)3Si-(CH2)3-S-(CH2)2-S-C(＝O)-C3H7、(EtO)3Si-(CH2)3-S-(CH2)2-S-C(＝O)-C4H9，(EtO)3Si-(CH2)3-S-(CH2)2-S-C(＝O)-C5H11、(EtO)3Si-(CH2)3-S-(CH2)2-S-C(＝O)-C6H13，(EtO)3Si-(CH2)3-S-(CH2)2-S-C(＝O)-C7H15、(EtO)3Si-(CH2)3-S-(CH2)2-S-C(＝O)-C9H19，(EtO)3Si-(CH2)3-S-(CH2)2-S-C(＝O)-C11H23、(EtO)3Si-(CH2)3-S-(CH2)2-S-C(＝O)-C13H27，(EtO)3Si-(CH2)3-S-(CH2)2-S-C(＝O)-C15H31、(EtO)3Si-(CH2)3-S-(CH2)2-S-C(＝O)-C17H35，(EtO)3Si-(CH2)3-S-(CH2)3-S-C(＝O)-CH3、(EtO)3Si-(CH2)3-S-(CH2)3-S-C(＝O)-C2H5，(EtO)3Si-(CH2)3-S-(CH2)3-S-C(＝O)-C3H7、(EtO)3Si-(CH2)3-S-(CH2)3-S-C(＝O)-C4H9，(EtO)3Si-(CH2)3-S-(CH2)3-S-C(＝O)-C5H11、(EtO)3Si-(CH2)3-S-(CH2)3-S-C(＝O)-C6H13，(EtO)3Si-(CH2)3-S-(CH2)3-S-C(＝O)-C7H15、(EtO)3Si-(CH2)3-S-(CH2)3-S-C(＝O)-C9H19，(EtO)3Si-(CH2)3-S-(CH2)3-S-C(＝O)-C11H23、(EtO)3Si-(CH2)3-S-(CH2)3-S-C(＝O)-C13H27，(EtO)3Si-(CH2)3-S-(CH2)3-S-C(＝O)-C15H31、(EtO)3Si-(CH2)3-S-(CH2)3-S-C(＝O)-C17H35，(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-CH3、(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-C2H5，(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-C3H7、(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-C4H9，(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-C5H11、(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-C6H13，(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-C7H15、(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-C9H19，(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-C11H23、(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-C13H27，(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-C15H31、(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-C17H35。
in a preferred embodiment of the invention, silane A, which has the variant of formula A-XI), has the following structure according to formula A-XII):
A-XII)(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-CH3，
this results in, inter alia, improved hysteresis behavior and improved tear properties.
In a preferred embodiment of the invention, silane A, having the variant of formula A-XI), has the following structure according to the formulae A-XIII):
A-XIII)(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-(CH2)6-CH3，
this results in, inter alia, improved hysteresis behavior and improved tear properties.
In a preferred embodiment of the invention, silane A, having the variant of formula A-XI), has the following structure according to formula A-XIV):
A-XIV)(EtO)3Si-(CH2)3-S-(CH2)6-S-C(＝O)-(CH2)16-CH3，
this results in, inter alia, improved hysteresis behavior and improved tear properties.
In a preferred embodiment of the invention, silane a, having the variant of formula a-XI), has the following structure according to the formula a-XV):
A-XV)(EtO)3Si-(CH2)3-S-C(＝O)-(CH2)6-CH3，
this results in, inter alia, improved hysteresis behavior and improved tear properties.
It is also conceivable for the rubber mixtures according to the invention to contain mixtures of two or more silanes A-II), A-III), A-XII), A-XIII), A-XIV), A-XV).
It is also conceivable that the rubber mixtures according to the invention contain mixtures of the cited silanes with at least one further silane of the above formulae A-I) and/or A-XI).
The total amount of silanes A present according to the formulae A-I) and A-XI) is in each case from 1phf to 30phf, preferably from 2phf to 20phf, particularly preferably from 2phf to 10 phf.
In an advantageous development of the invention, the amount of silane a present is at least 2.5 phf.
In a further advantageous development of the invention, the amount of silane a present is at least 3 phf.
In a further advantageous development of the invention, the amount of silane a present is at least 3.5 phf.
The preferred minimum amounts of the respective amounts also apply when only one type a of silane is present.
The particularly preferred and particularly preferred amounts and the cited developments/embodiments lead to very good properties with regard to the rolling resistance prediction index and the optimized tear properties.
Silanes B of the formula B-I) may preferably be:
(EtO)3Si-(CH2)-S-(CH2)-Si(OEt)3、(EtO)3Si-(CH2)2-S-(CH2)2Si(OEt)3、(EtO)3Si-(CH2)3-S-(CH2)3Si(OEt)3、(EtO)3Si-(CH2)4-S-(CH2)4Si(OEt)3、(EtO)3Si-(CH2)5-S-(CH2)5Si(OEt)3、(EtO)3Si-(CH2)6-S-(CH2)6Si(OEt)3、(EtO)3Si-(CH2)7-S-(CH2)7Si(OEt)3、(EtO)3Si-(CH2)8-S-(CH2)8-Si(OEt)3、(EtO)3Si-(CH2)9-S-(CH2)9-Si(OEt)3、(EtO)3Si-(CH2)10-S-(CH2)10-Si(OEt)3。
in a preferred embodiment of the invention, silane B has the following structure according to formula B-II):
B-II)(EtO)3Si-(CH2)3-S-(CH2)3-Si(OEt)3。
it is also conceivable for the rubber mixtures according to the invention to contain a mixture of two silanes of the formula B-I), for example B-II), with another silane of the formula B-I).
The total amount of silanes B of the formula B-I) is in each case from 0.5phf to 30phf, preferably from 0.5phf to 20phf, particularly preferably from 1phf to 10 phf.
In an advantageous development of the invention, the amount of silane B present is at least 0.7 phf.
In a further advantageous development of the invention, the amount of silane B present is at least 1.0 phf.
In a further advantageous development of the invention, the amount of silane B present is at least 1.5 phf.
The respective preferred minimum amounts also apply when only one type B of silane is present.
The particularly preferred and particularly preferred amounts and developments lead to very good properties with regard to the rolling resistance prediction index and the optimized tear properties.
The silanes A and/or B present according to the invention can be applied to a support, for example a wax, a polymer or carbon black, and can be added in this form to the rubber mixture. The silanes a and/or B present according to the invention can be applied to the silicon dioxide, wherein the bonding can be physical or chemical.
Silanes a and B may be applied to the silica separately from one another and then the silicas are added to the mixture, or silanes a and B may be applied together to one silica.
When ethoxy-substituted silanes (R) are used1As ethoxy), the application of the silanes a and/or B present according to the invention to the silica reduces the emission of, for example, volatile by-products (e.g. ethanol).
Particular preference is given to silane A being present in a molar ratio to silane B being present of from 20:80 to 90:10, preferably from 25:75 to 90:10, particularly preferably from 30:70 to 90:10, very particularly preferably from 35:65 to 90: 10.
Preferably, at least silane a is present in an amount of at least 2phf, particularly preferably at least 2.5phf, and at least silane B is present in an amount of at least 0.7phf, preferably at least 1.0phf, particularly preferably at least 1.5 phf.
In an advantageous embodiment of the invention, the silane or silanes A and B are preferably mixed with one another in the molar ratios A and B listed before addition to the rubber mixture.
Thus the silane needs to be added only once and thus only one form of addition is needed.
The mixing of the silanes can be carried out with the exclusion of air. The mixing of the silanes can be carried out under a protective atmosphere, for example under argon or nitrogen, preferably under nitrogen.
The mixing of the silanes can be carried out at standard pressure, elevated pressure or reduced pressure. The mixing of the silanes can preferably be carried out at standard pressure. The high pressure can be a pressure of from 1.1 bar to 100 bar, preferably from 1.1 bar to 50 bar, particularly preferably from 1.1 bar to 10 bar and very particularly preferably from 1.1 bar to 5 bar. The reduced pressure can be a pressure of 1 mbar to 1000 mbar, preferably 250 mbar to 1000 mbar, particularly preferably 500 mbar to 1000 mbar.
The mixing of the silanes can be carried out at between 20 ℃ and 100 ℃, preferably between 20 ℃ and 50 ℃, particularly preferably between 20 ℃ and 30 ℃.
The mixing of the silane may be performed in a solvent such as methanol, ethanol, propanol, butanol, cyclohexanol, N-dimethylformamide, dimethyl sulfoxide, pentane, hexane, cyclohexane, heptane, octane, decane, toluene, xylene, acetone, acetonitrile, carbon tetrachloride, chloroform, dichloromethane, 1, 2-dichloroethane, tetrachloroethylene, diethyl ether, methyl tert-butyl ether, methyl ethyl ketone, tetrahydrofuran, dioxane, pyridine or methyl acetate, or a mixture of the above solvents. The mixing of the silanes is preferably carried out in the absence of a solvent.
It is further conceivable that the rubber mixtures according to the invention contain at least one further silane coupling agent which is not silane a or silane B.
Furthermore, the rubber mixtures may contain further activators and/or agents for binding fillers, in particular carbon black. Examples thereof are the compounds S- (3-aminopropyl) thiosulfuric acid and/or metal salts thereof disclosed in EP 2589619A 1, which achieve very good physical properties of the rubber mixtures, in particular in combination with at least one carbon black as filler.
The rubber mixtures may further contain conventional additives in conventional weight fractions, which are preferably added in at least one basic mixing stage in the production of the mixtures. These additives include
a) Anti-aging additives, for example N-phenyl-N '- (1, 3-dimethylbutyl) -p-phenylenediamine (6PPD), N' -diphenyl-p-phenylenediamine (DPPD), N '-ditolyl-p-phenylenediamine (DTPD), N-isopropyl-N' -phenyl-p-phenylenediamine (IPPD), 2, 4-trimethyl-1, 2-dihydroquinoline (TMQ),
b) activators, for example zinc oxide and fatty acids (e.g. stearic acid) and/or other activators, such as zinc complexes, for example zinc ethylhexanoate,
c) the amount of wax is such that,
d) hydrocarbon resins, such as in particular optional binder resins,
e) plasticating auxiliaries, for example 2, 2' -dibenzamidodiphenyl disulfide (DBD), and
f) processing aids, such as in particular fatty acid esters and metal soaps, for example zinc soaps and/or calcium soaps,
g) and (3) a plasticizer.
The plasticizers used in the context of the present invention comprise all plasticizers known to the person skilled in the art, such as aromatic, naphthenic or paraffinic mineral oil plasticizers, for example MES (mild extraction solvate) or RAE (residual aromatic extract) or TDAE (treated distilled aromatic extract), or liquid rubber-to-liquid oil (RT L) or liquid biomass-to-liquid oil (BT L) preferably having a polycyclic aromatic content of less than 3% by weight according to method IP 346, or triglycerides, for example rapeseed oil or factice or hydrocarbon resins, or liquid polymers having an average molecular weight between 500g/mol and 20000 g/mol (determined by GPC, based on BS ISO 11344: 2004).
The plasticizer is preferably selected from the group consisting of the above plasticizers.
The plasticizer is particularly preferably selected from the group consisting of: hydrocarbon resins, liquid polymers and mineral oils.
When mineral oil is used, the oil is preferably selected from the group consisting of: DAE (distilled aromatic extract) and/or RAE (residual aromatic extract) and/or TDAE (treated distilled aromatic extract) and/or MES (mild extracted solvent) and/or naphthenic oils.
In a preferred embodiment of the invention, the rubber mixture contains at least one mineral oil plasticizer, preferably at least TDAE and/or RAE as plasticizer. This results in particularly good processability characteristics of the rubber mixtures, in particular good miscibility.
In a preferred embodiment of the invention, the rubber mixture contains at least one liquid polymer as plasticizer.
In a preferred embodiment of the invention, the rubber mixture contains at least one hydrocarbon resin as plasticizer.
The person skilled in the art will understand that hydrocarbon resins are polymers composed of monomers, and that hydrocarbon resins linked to each other via monomers formally consist of derivatives of the monomers. However, in the context of the present invention, these hydrocarbon resins are not included in the rubber. In the context of the present application, the term "hydrocarbon resin" includes resins which may comprise carbon and hydrogen atoms and optionally heteroatoms, such as in particular oxygen atoms. The hydrocarbon resin may be a homopolymer or a copolymer. In this application, according toAt line version 3.28, homopolymer is understood to mean a polymer "formed from only one type of monomer". These monomers may be chosen from any of the monomers of hydrocarbon resins known to the person skilled in the art, such as aliphatic C5Monomers, and further unsaturated compounds which can be cationically polymerized, including aromatic compounds and/or terpenes and/or olefins and/or cyclic olefins.
In a preferred embodiment of the invention, the hydrocarbon resin is selected from the group consisting of: aliphatic C5Resin and α -hydrocarbon resins of methyl styrene and styrene.
The hydrocarbon resins preferably have a softening point according to ASTM E28 (Ring and ball method) of from 10 ℃ to 180 ℃, particularly preferably from 60 ℃ to 150 ℃, very particularly preferably from 80 ℃ to 99 ℃. The hydrocarbon resins preferably also have a molecular weight Mw of from 500 to 4000g/mol, preferably from 1300 to 2500 g/mol.
The amount fraction of the total amount of further additives is from 3 to 150phr, preferably from 3 to 100phr and particularly preferably from 5 to 80 phr.
Zinc oxide (ZnO) may be included in the total amount fraction of other additives. It may be selected from all types of zinc oxide known to the person skilled in the art, such as ZnO particles or powders. Conventionally used zinc oxides generally have a particle size of less than 10m2BET surface area in g. However, it is also possible to use a filter having 10m2G to 100m2Zinc oxide with a BET surface area of/g, for example the so-called "nano-zinc oxide".
In particular, when using the rubber mixtures according to the invention for the interior components of tires or industrial rubber articles which are in direct contact with the strength members present, it is also customary to add suitable adhesive systems (often in the form of adhesive resins) to the rubber mixtures.
The vulcanization is preferably carried out in the presence of sulfur and/or a sulfur donor and with the aid of vulcanization accelerators, some of which can also act as sulfur donors.
In a final mixing step sulphur and/or a further sulphur donor and one or more accelerators are added to the rubber mixture. The accelerator is selected from the group consisting of: a thiazole accelerator and/or a mercapto group-containing accelerator and/or a sulfenamide accelerator and/or a thiocarbamate accelerator and/or a thiuram accelerator and/or a phosphorothioate accelerator and/or a thiourea accelerator and/or a xanthate accelerator and/or a guanidine accelerator.
It is preferred to use at least one sulfenamide accelerator selected from the group consisting of: n-cyclohexyl-2-benzothiazolesulfenamide (CBS) and/or N, N-dicyclohexylbenzothiazole-2-sulfenamide (DCBS) and/or benzothiazolyl-2-sulfenylmorpholine (MBS) and/or N-tert-butyl-2-benzothiazolesulfenamide (TBBS).
The sulfur donating species that can be used can be any sulfur donating species known to those skilled in the art. When the rubber mixture contains a sulfur-donating substance, said substance is preferably selected from the group comprising, for example, thiuram disulfides, such as tetrabenzylthiuram disulfide (TBzTD) and/or tetramethylthiuram disulfide (TMTD) and/or tetraethylthiuram disulfide (TETD), and/or thiuram tetrasulfide, such as dipentamethylenethiuram tetrasulfide (DPTT) and/or dithiophosphates, such as
Dipdis (bis (diisopropyl) thiophosphoryl disulfide) and/or bis (O, O-2-ethylhexyl thiophosphoryl) polysulfides (e.g. Rhenocure SDT)Rheinchemie GmbH) and/or zinc dichlorooxydisulphosphate (e.g., Rhenocure)Rhine chemical company) and/or zinc alkyldithiophosphates, and/or 1, 6-bis (N, N-dibenzylthiocarbamoyldithio) hexane and/or diaryl polysulfides and/or dialkyl polysulfides.
Further additives such as, for example, those known under the trade name, may be used in the rubber mixture OrA network forming system available from below, or a network forming system as described, for example, in WO2010/049216a 2. This system contains a vulcanizing agent crosslinked with a functionality greater than four and at least one vulcanization accelerator.
The required amount of additional sulphur in the form of elemental sulphur and/or additional sulphur donors depends on the field of use of the respective rubber mixture. The corresponding amounts added are known to the person skilled in the art. For the addition of elemental sulphur, the amount in the case of a rubber mixture for the beads of vehicle tyres is for example between 0phr and 5 phr. For treads for vehicle tires, which generally have a lower sulfur content than the beads, the amount of elemental sulfur to be added is preferably from 0phr to 4 phr.
In an advantageous development of the invention, a plurality of accelerators is used. Preference is given to using sulfenamide accelerators, particularly preferably CBS, in combination with guanidine accelerator DPG (diphenylguanidine). The amount of DPG here is from 0phr to 5phr, preferably from 0.1phr to 3phr, particularly preferably from 0.5phr to 2.5phr, very particularly preferably from 1phr to 2.5 phr.
Curing retarders may also be present in the rubber mixture.
The terms "vulcanized" and "crosslinked" are used synonymously in the context of the present invention.
The invention further provides a process for producing the sulfur-crosslinkable rubber mixtures according to the invention, in which a base mixture comprising all the constituents except the vulcanization system is first produced in one or more mixing stages. The final mixture is produced in the final mixing stage by adding a vulcanization system. The final mixture is further processed, for example by an extrusion operation or calendering, and brought into a suitable shape. This is followed by further processing by vulcanization, wherein sulfur crosslinking occurs due to the vulcanization system added in the context of the present invention.
In an advantageous embodiment of the process according to the invention, the silane or silanes a and B are mixed with one another, preferably in the listed molar ratios a and B and under the abovementioned conditions, including all the specifications described, before being added to the rubber mixture.
In an advantageous embodiment of the process according to the invention, the silanes a and/or B have been applied to the silica, wherein the bonding can be physical or chemical, and is preferably added to the rubber mixture in this form in the basic mixing stage.
The rubber mixtures according to the invention are particularly suitable for use in vehicle tires, in particular pneumatic vehicle tires. In principle, use in any tire component is conceivable, in particular in a tread, in particular in the crown of a tread having the above-described crown/base construction.
For use in vehicle tyres, the mixture is preferably brought into the shape of the tread as the final mixture before vulcanization and applied in a known manner to the production process of a green vehicle tyre.
As mentioned above, the production of the rubber mixtures according to the invention is carried out, which are used as sidewalls or other body mixtures for vehicle tires. The difference is the formation after the extrusion operation/calendering of the mixture. The so obtained form of the not yet vulcanized rubber mixture for one or more different bulk mixtures is then used for the building of a green tyre.
The term "body mix" is understood to mean a rubber mix for other component parts of the tire, such as, mainly, separator plates, inner linings (inner layers), ring core profiles, belts, shoulders, belt profiles, carcasses, bead reinforcements, bead profiles, flange profiles and belts. In order to use the rubber mixtures according to the invention in transmission belts and other belts, in particular in conveyor belts, the extruded, not yet vulcanized mixture is shaped appropriately and often simultaneously or subsequently provided with strength members, such as synthetic fibers or steel cords. This generally provides a multilayer construction consisting of one and/or more rubber compound layers, one and/or more identical and/or different strength member layers and one and/or more additional layers of the same and/or another rubber compound.
Detailed Description
The invention will now be explained in more detail with the aid of comparative and working examples, which are summarized in the following table.
The general composition of the rubber mixtures on which the examples are based is summarized in table 1 as R1 (formulation 1). Both the type of silane and the amount of silane used were then varied in tables 2 to 8 to provide comparative and inventive mixtures. The comparative mixture is labeled V and the inventive mixture is labeled E. Tables 2 to 4 are relevant and relevant tests include the addition of silane B in addition to silane a. Tables 5 to 8 show further working examples and associated test series, which here include the complete or partial replacement of silane a with silane B, starting from the comparative mixture.
In each case, the respective silanes are premixed with one another and then added to the rubber mixture in the basic mixing stage. The amount of silane reported (in phf) is related to 95phr of silica.
Production of 1-chloro-6-thiopropyltriethoxysilylhexane
NaOEt (21% in EtOH; 1562 g; 4.820mol) was added to mercaptopropyltriethoxysilane (1233 g; 5.170mol) over 1h with stirring at room temperature. Once the addition was complete, the reaction mixture was heated at reflux for 2 hours and then cooled to room temperature. The intermediate formed was added to 1, 6-dichlorohexane (4828 g; 31.14mol) which had been heated to 80 ℃ within 30 min. Once the addition was complete, the reaction mixture was heated at reflux for 3 hours and then cooled to room temperature. The reaction mixture was filtered and the filter cake was rinsed with EtOH. Volatile components were removed under reduced pressure, and 1-chloro-6-thiopropyltriethoxysilylhexane (yield: 89%, molar ratio: 97% of 1-chloro-6-thiopropyltriethoxysilylhexane, 3% of bis (thiopropyltriethoxysilyl) hexane), an intermediate product was obtained as a colorless to brown liquid; in weight percent: 95% by weight of 1-chloro-6-thiopropyltriethoxysilylhexane, 5% by weight of 1, 6-bis (thiopropyltriethoxysilyl) hexane.
f)The silane was produced as follows:
first, Na is added2CO3(59.78 g; 0.564mol) and an aqueous solution of NaSH (40%; 79.04 g; 0.564mol in water) were added together with water (97.52 g). Tetrabutylphosphonium bromide (TBPB) (50% in water; 3.190 g; 0.005mol) was then added and acetyl chloride (40.58 g; 0.517mol) was added dropwise over 1h, maintaining the reaction temperature between 25 ℃ and 32 ℃. After completion of acetyl chloride addition, the mixture was stirred at room temperature for 1 h. TBPB (50%; 3.190 g; 0.005mol) and 1-chloro-6-thiopropyltriethoxysilylhexane (see above; 167.8 g; 0.470mol) were then added and the mixture was heated at reflux for 3-5 h. The progress of the reaction was monitored by gas chromatography. Once 1-chloro-6-thiopropyltriethoxysilaneReaction of the hexane to>To a degree of 96%, water is added until all salts are dissolved and the phases are separated. The volatile constituents of the organic phase are removed under reduced pressure and a yellow to brown liquid is obtained
S- (6- ((3- (triethoxysilyl) propyl) thio) hexyl) thioacetate)
(yield: 90%, molar ratio: 97% S- (6- ((3- (triethoxysilyl) propyl) thio) hexyl) thioacetate (silane a-XII), 3% bis (thiopropyltriethoxysilyl) hexane;
in weight percent: 96% by weight of S- (6- ((3- (triethoxysilyl) propyl) thio) hexyl) thioacetate (silane a-XII), 4% by weight of 1, 6-bis (thiopropyltriethoxysilyl) hexane).
g)The silane was produced as follows:
first, Na is added2CO3(220.2 g; 2.077mol) and an aqueous solution of NaSH (40%; 291.2 g; 2.077mol in water) were added together with water (339.2 g). Tetrabutylammonium bromide (TBAB) (50% in water; 10.96 g; 0.017mol) was then added and octanoyl chloride (307.2 g; 1.889mol) was added dropwise over 2.5h, maintaining the reaction temperature at 24 ℃ to 28 ℃. After the octanoyl chloride addition was complete, the mixture was stirred at room temperature for 1 h. TBAB (50% in water; 32.88 g; 0.051mol) and 1-chloro-6-thiopropyltriethoxysilylhexane (see above; 606.9 g; 1.700mol) were then added and the mixture was heated at reflux for 10 h. Water was then added until all salts were dissolved and the phases separated. The volatile components of the organic phase were removed under reduced pressure and S- (6- ((3- (triethoxysilyl) propyl) thio) hexyl) thiocaprylate was obtained as a yellow to brown liquid (yield: 95%,
the molar ratio is as follows: 97% S- (6- ((3- (triethoxysilyl) propyl) thio) hexyl) thiooctanoate (silane A-XIII), 3% bis (thiopropyltriethoxysilyl) hexane;
in weight percent: 96% by weight of S- (6- ((3- (triethoxysilyl) propyl) thio) hexyl) thiooctanoate, 4% by weight of 1, 6-bis (thiopropyltriethoxysilyl) hexane).
According to synthetic examples 1 and 3 in JP 2012149189, from 1-chloro-6-thiopropyltriethoxysilylhexane (see above) h)Silane。
S- (6- ((3- (triethoxysilyl) propyl) thio) hexyl) thiooctadecanoate (yield: 89%, molar ratio: 97% S- (6- ((3- (triethoxysilyl) propyl) thio) hexyl) thiooctadecanoate (silane A-XIV), 3% bis (thiopropyltriethoxysilyl) hexane; in% by weight: 97% by weight S- (6- ((3- (triethoxysilyl) propyl) thio) hexyl) thiooctadecanoate, 3% by weight 1, 6-bis (thiopropyltriethoxysilyl) hexane) is obtained as a yellow to brown liquid.
i)The silane was produced as follows:
6-bis (thiopropyltriethoxysilylhexyl) disulfide was produced according to synthesis example 1 and example 1 of EP 1375504.
In contrast to synthesis example 1 of EP 1375504, no intermediates were distilled.
And (3) analysis: (yield: 88%, molar ratio:
silanes having the formula a-II: 94% (EtO)3Si(CH2)3S(CH2)6S2(CH2)6S(CH2)3Si(OEt)3And 6% (EtO)3Si(CH2)3S(CH2)6S(CH2)3Si(OEt)3，
In weight percent: silanes having the formula a-II: 95% by weight (EtO)3Si(CH2)3S(CH2)6S2(CH2)6S(CH2)3Si(OEt)3And 5% by weight (EtO)3Si(CH2)3S(CH2)6S(CH2)3Si(OEt)3)。
k)Production of bis (triethoxysilylpropyl) sulfide (silane, B-II)
To a solution of chloropropyltriethoxysilane (361 g; 1.5 mol; 1.92 eq) in ethanol (360ml) was added in portions Na at a rate such that the temperature did not exceed 60 deg.C2S (61.5 g; 0.78 mol; 1.00 eq.). Once the addition was complete, the mixture was heated at reflux for 3 hours and then allowed to cool to room temperature. The reaction product was filtered to remove precipitated salts. Purification by distillation (0.04 mbar; 110 ℃) gave the product (yield: 73%, purity:>99％，13C-NMR) as a clear liquid.
NMR method: the molar ratios and mass fractions reported in the examples as analytical results were determined by13Obtained by C-NMR measurement, using the following parameters: 100.6MHz, 1000 scans in CDCl solvent3Internal standards for calibration: tetramethylsilane, relaxation agent Cr (acac)3To determine the mass fraction in the product, a defined amount of dimethyl sulfone is added as an internal standard and the molar ratio of the product to it is used to calculate the mass fraction.
In addition, the mixture production is carried out by the methods customary in the rubber industry in three stages under typical conditions in a laboratory mixer having a capacity of 300 ml to 3 l, in the first mixing stage (basic mixing stage) all the ingredients except the vulcanization system (sulfur and substances influencing vulcanization) being first mixed at 145 ℃ to 165 ℃ (target temperature 152 ℃ to 157 ℃) for 200 to 600 seconds. In the second stage, the mixture from stage 1 is mixed again, i.e. subjected to so-called regrinding. In the third stage (final mixing stage) the vulcanization system is added, resulting in a final mixture, which is mixed at 90 to 120 ℃ for 180 to 300 seconds.
Passing t under pressure at 160 ℃ to 170 ℃95To t100Vulcanization (measured on a moving disk rheometer according to ASTM D5289-12/ISO 6502) all the mixtures were used to produce test samples and these test samples were used to determine typical material properties for the rubber industry with the test methods reported hereinafter.
Shore A hardness at room temperature according to DIN ISO 7619-1
Dynamic storage modulus E' reported values at 55 ℃ from dynamic mechanical measurements (strain scans at 0.15% and 8% elongation) according to DIN 53513: e 'at 0.15% minus E at 8'
Loss factor tan (10%) and dynamic storage modulus (G '(1%), G' (100%)) from a second strain scan at 1Hz and 70 ℃ from RPA (rubber processing analyzer) based on ASTM D6601; reporting a value: g 'at 1% minus G at 100'
Energy density at break determined in the tensile test in accordance with DIN 53504, where the energy density at break is the work required up to break based on the sample volume Table 1
Composition (I)
Unit of
R1
NR TSR
phr
10
BRo)
phr
18
SSBRp)
phr
72
Silicon dioxidea)
phr
95
TDAE
phr
50
Other additivesb)
phr
9
Silane (different)d)
phf
Is different
Acceleratorc)
phr
4
Sulfur
phr
2
The substances used were:
a) silicon dioxide: VN3 winning company
b) Other additives: anti-aging additive, antiozonant wax, zinc oxide, stearic acid
c)DPG+CBS
d) Silane variants according to e) to m)
e) NXT, Momentive (miiki group); containing silanes of the formula A-XV) to an extent of > 90% by weight
f) Containing 97 mol% of a silane of the formula A-II), produced as described above
g) Containing 97 mol% of a silane of the formula A-III), produced as described above
h) Containing 97 mol% of silanes of the formulae A to IV), produced as described above
i) Containing a silane having the formula a-II), wherein x ═ 2: (EtO)3Si-(CH2)3-S-(CH2)6-S2-(CH2)6-S-(CH2)3-Si(OEt)3(6-bis (thiopropyltriethoxysilylhexyl) disulfide) with a purity of 94 mol% (95% by weight)
j)SiA winning and creating company; contains TESPD: a silane having the formula a:
A*(EtO)3Si-(CH2)3-Sx-(CH2)3-Si(Oet)3bonded but not under the formula A-I) according to the invention, comprises 75% by weight of S in the silane mixture2(x ═ 2) and 7% by weight of S1(x ═ 1) (and 18% by weight, x>2)
k) Silane B-II): (EtO)3Si-(CH2)3-S-(CH2)3-Si(Oet)3Produced as above
l) the mole fraction of non-bonded silanes B-II) in the mole fraction of the silane mixture, in% of non-bonded silanes B-II) in the silane mixture): from added silanesj)And silanesk)Calculated (i.e. taking into account silane)j)Medium to low mol% silane B-II))
m) silane B: bis-triethoxysilyloctane from the company ABCR, not bound but not according to the invention, under the formula B-I)
n) mole fraction of non-bonded silanes B in the silane mixture:
o) polybutadiene: europrene Neocci BR 40, Polymer (Polimeri)
p)S L R-4601, Shengxi ao corporation (Trinseo)
TABLE 2
TABLE 3
TABLE 4
TABLE 5
TABLE 6
TABLE 7
Silane
Unit of
E14
E15
E16
E17
E18
E19
Silanei)
phf
8.6
6.4
4.3
-
-
-
Silanef)
phf
-
-
-
9.6
7.2
4.8
Silanek)
phf
1.3
2.7
4.0
1.3
2.7
4.0
B-II)l)Mol% of
Mol％
20
40
60
11
25
43
Tan d(10％)
0.160
0.161
0.165
0.159
0.161
0.169
Hardness at room temperature
Shore A
61.0
61.0
58.5
60.5
60.4
59.0
TABLE 8
It is evident from the table that the rubber mixtures according to the invention exhibit a reduced payne effect compared to the prior art, as is evident from the smaller difference in the dynamic storage modulus E 'measured by eplex and the dynamic stiffness G' measured by RPA. The rubber mixtures according to the invention therefore exhibit an improved hysteresis behavior and thus an improved rolling resistance index. This is also evident from the lower values of tan. In addition, the rubber mixtures according to the invention exhibit an increased energy density at break and thus improved tear properties. Furthermore, the hardness of the rubber mixtures according to the invention is maintained at a comparable level compared with the prior art.