阅读说明：本技术 硅烷、含有该硅烷的橡胶混合物以及在至少一个部件中具有该橡胶混合物的车辆轮胎 (Silane, rubber mixture containing the silane, and vehicle tire having the rubber mixture in at least one component ) 是由 安德里亚斯·雅各布 大卫-拉斐尔·道尔 尤利安·施特罗迈尔 尤利娅·舍费尔 卡拉·雷克 基 于 2018-05-14 设计创作，主要内容包括：本发明涉及一种硅烷、一种包含该硅烷的橡胶混合物以及一种在至少一个部件中包含该橡胶混合物的车辆轮胎。本发明的硅烷具有以下式I)(R<Sup>1</Sup>)<Sub>o</Sub>Si-R<Sup>2</Sup>-X-A-Y-[A-Y-]<Sub>m</Sub>-A-S<Sub>k</Sub>-A-[-Y-A]<Sub>m</Sub>-Y-A-X-R<Sup>2</Sup>-Si(R<Sup>1</Sup>)<Sub>o</Sub>,其中,根据本发明,该硅烷在相应的甲硅烷基与S<Sub>k</Sub>部分之间具有间隔基,这些间隔基具有至少两个芳族基团A和连接单元X和Y,其中分子内的基团X可以彼此相同或不同,并且选自基团-HNC(＝O)-、-C(＝O)NH-、-C(＝O)O-、-OC(＝O)-、-OC(＝O)NH-、-HNC(＝O)O-、-R<Sup>3</Sup>NC(＝O)NR<Sup>3</Sup>-、-R<Sup>3</Sup>NC(＝NR<Sup>3</Sup>)NR<Sup>3</Sup>-、-R<Sup>3</Sup>NC(＝S)NR<Sup>3</Sup>-,其中每个基团X内的至少一个R<Sup>3</Sup>是氢原子；并且其中分子内的基团Y可以彼此相同或不同,并且选自基团-HNC(＝O)-、-C(＝O)NH-、-C(＝O)O-、-OC(＝O)-、-OC(＝O)NH-、-HNC(＝O)O-、-R<Sup>4</Sup>NC(＝O)NR<Sup>4</Sup>-、-R<Sup>4</Sup>NC(＝NR<Sup>4</Sup>)NR<Sup>4</Sup>-、-R<Sup>4</Sup>NC(＝S)NR<Sup>4</Sup>-,其中每个基团Y内的至少一个R<Sup>4</Sup>是氢原子。本发明的橡胶混合物包含至少一种本发明的硅烷。(The invention relates to a silane, a rubber mixture containing the silane and a vehicle tire containing the rubber mixture in at least one component. The silanes of the invention have the following formula I) (R) 1 ) o Si‑R 2 ‑X‑A‑Y‑[A‑Y‑] m ‑A‑S k ‑A‑[‑Y‑A] m ‑Y‑A‑X‑R 2 ‑Si(R 1 ) o Wherein, according to the invention, the silane is reacted in the corresponding silyl group with S k Between partsHaving spacers which have at least two aromatic radicals A and linking units X and Y, where the radicals X in the molecule may be identical to or different from one another and are selected from the groups-HNC (═ O) -, -C (═ O) NH-, -C (═ O) O-, -OC (═ O) -, -OC (═ O) NH-, -HNC (═ O) O-, -R ═ O) -, -O 3 NC(＝O)NR 3 ‑、‑R 3 NC(＝NR 3 )NR 3 ‑、‑R 3 NC(＝S)NR 3 -, where at least one R in each radical X 3 Is a hydrogen atom; and wherein the groups Y within the molecule may be the same or different from each other and are selected from the groups-HNC (═ O) -, -C (═ O) NH-, -C (═ O) O-, -OC (═ O) NH-, -HNC (═ O) O-, -R-, -O 4 NC(＝O)NR 4 ‑、‑R 4 NC(＝NR 4 )NR 4 ‑、‑R 4 NC(＝S)NR 4 -, where at least one R in each radical Y 4 Is a hydrogen atom. The rubber mixtures according to the invention comprise at least one silane according to the invention.)

1. A silane having the formula I):

I)(R¹)_oSi-R²-X-A-Y-[A-Y-]_m-A-S_k-A-[-Y-A]_m-Y-A-X-R²-Si(R¹)_o

wherein o can be 1,2 or 3, and k is an integer greater than or equal to 2, and is in the silyl group (R)¹)_oSi-and groups R on both sides of the molecule¹May be the same as or different from each other and is selected from alkoxy groups having 1 to 10 carbon atoms, cycloalkoxy groups having 4 to 10 carbon atoms, phenoxy groups having 6 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, alkyl groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, aralkyl groups having 7 to 20 carbon atoms, a halide, or

Alkyl polyether radical-O- (R)⁶-O)_r-R⁵Wherein R is⁶Identical or different and branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C₁-C₃₀Hydrocarbyl, preferably-CH₂-CH₂-, R is an integer from 1 to 30, preferably from 3 to 10, and R⁵Is an unsubstituted or substituted, branched or unbranched, monovalent alkyl, alkenyl, aryl or aralkyl radical, preferably-C₁₃H₂₇Alkyl radical

Or

Two R¹Form a cyclic dialkoxy radical having from 2 to 10 carbon atoms, in which case o is<3，

Or two or more silanes of the formula I) may pass through the radical R¹Bridging; and is

Wherein the radicals R are intramolecular²May be the same or different, andis a linear or branched alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 4 to 12 carbon atoms or an aryl group having 6 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms; and is

Wherein the groups X in the molecule may be identical to or different from each other and are selected from the groups-HNC (═ O) -, -C (═ O) NH-, -C (═ O) O-, -OC (═ O) NH-, -HNC (═ O) O-, -R-, -O³NC(＝O)NR³-、-R³NC(＝NR³)NR³-、-R³NC(＝S)NR³-, where the radicals R are in the radical X and in the molecule³May be the same or different and is selected from a hydrogen atom or at least one R as in each group X³Is a hydrogen atom for R²As defined; and is

Wherein the groups A in the molecule may be the same as or different from each other and are aromatic groups, and

wherein the groups Y in the molecule may be identical to or different from each other and are selected from the groups-HNC (═ O) -, -C (═ O) NH-, -C (═ O) O-, -OC (═ O) NH-, -HNC (═ O) O-, -R-, -O⁴NC(＝O)NR⁴-、-R⁴NC(＝NR⁴)NR⁴-、-R⁴NC(＝S)NR⁴-, where the radicals R are in the radical Y and in the molecule⁴May be identical or different and is selected from a hydrogen atom or at least one R as in each radical Y⁴Is a hydrogen atom for R²As defined; and wherein each m is independently an integer from 0 to 4, and wherein the silane may also be in the form of an oligomer formed by hydrolysis and condensation of a silane of formula I).

2. The silane of claim 1, wherein each m is 0.

3. The silane according to any one of the preceding claims, wherein the radicals X are selected from the groups-HNC (═ O) -, -C (═ O) NH-, -OC (═ O) NH-, -HNC (═ O) O-, -R³NC(＝O)NR³-、-R³NC(＝NR³)NR³-、-R³NC(＝S)NR³-。

4. The silane according to any one of the preceding claims, wherein the radicals Y are selected from the groups-HNC (═ O) -, -C (═ O) NH-, -OC (═ O) NH-, -HNC (═ O) O-, -R⁴NC(＝O)NR⁴-、-R⁴NC(＝NR⁴)NR⁴-、-R⁴NC(＝S)NR⁴-。

5. The silane according to any one of the preceding claims, characterized in that the aromatic groups a are selected from the group consisting of: phenyl, naphthyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, quinolinyl, pyrrolyl, furanyl, thiophenyl, pyrazolyl, imidazolyl, thiazolyl, and oxazolyl groups.

6. The silane according to any of the preceding claims, wherein the radicals R are¹Is an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms or a halide.

7. The silane according to any of the preceding claims, wherein the radicals R are²Is a straight or branched alkyl group having 2 to 8 carbon atoms or a cycloalkyl group having 4 to 8 carbon atoms.

8. The silane of claim 1, having the following formula II):

II)

9. the silane of claim 1, having the following formula III):

III)

10. the silane of any one of the preceding claims, wherein k is an integer from 2 to 8.

11. A rubber compound comprising at least one silane as claimed in any one of claims 1 to 10.

12. A vehicle tire comprising the rubber mixture of claim 11 in at least one component.

Technical Field

The invention relates to a silane, a rubber mixture containing the silane and a vehicle tire containing the rubber mixture in at least one component.

Background

Silanes are known as additives for rubber mixtures, in particular for vehicle tires, and in particular as additives for rubber mixtures which comprise at least one silica as filler. Silanes known from the prior art are disclosed, for example, in DE 2536674C 3 and DE 2255577C 3. In this case, the silica is attached to the polymer or polymers by means of such silanes, which are therefore also referred to as coupling agents. The attachment of silica by means of silane coupling agents is advantageous with respect to the rolling resistance characteristics and processability of the rubber mixtures. To this end, the silanes typically have at least one sulfur moiety which participates in the vulcanization of the rubber mixture.

However, in addition to the properties mentioned, other properties of the rubber mixtures also play an important role, in particular when used in vehicle tires, such as in particular the stiffness of the mixture, which influences in particular the handling characteristics of the vehicle tire.

WO 2015/172915 a1 discloses a rubber mixture comprising urea-containing silanes having a higher stiffness than in the prior art, with almost constant indices of rolling resistance and wet grip. The urea groups are present here in the spacer, that is to say between the silicon (attached to the filler) and the sulfur (attached to the diene rubber).

JP P2002-201312 a proposes silanes for rubber mixtures having urea moieties or acid amide and phenyl groups in the spacer, whereby it would be possible to achieve improved dispersion of carbon black or silica as filler in the rubber mixture.

Disclosure of Invention

The object of the present invention is to provide a novel silane and to provide a rubber mixture comprising the silane, by means of which a further improvement in the stiffness and thus in the handling prediction index of the rubber mixture over the prior art is achieved, in particular for use in vehicle tires.

This object is achieved by the inventive silane, the inventive rubber mixture comprising this silane and also the inventive vehicle tire comprising the inventive rubber mixture in at least one component as claimed in claim 1.

The silane of the present invention has the following formula I):

I)(R¹)_oSi-R²-X-A-Y-[A-Y-]_m-A-S_k-A-[-Y-A]_m-Y-A-X-R²-Si(R¹)_o，

wherein o can be 1,2 or 3, and k is an integer greater than or equal to 2, and is in the silyl group (R)¹)_oSi-and groups R on both sides of the molecule¹May be the same as or different from each other and is selected from alkoxy groups having 1 to 10 carbon atoms, cycloalkoxy groups having 4 to 10 carbon atoms, phenoxy groups having 6 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, alkyl groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, aralkyl groups having 7 to 20 carbon atoms, a halide, or

Alkyl polyether radical-O- (R)⁶-O)_r-R⁵Wherein R is⁶Identical or different and branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C₁-C₃₀Hydrocarbyl, preferably-CH₂-CH₂-, R is an integer from 1 to 30, preferably from 3 to 10, and R⁵Is an unsubstituted or substituted, branched or unbranched, monovalent alkyl, alkenyl, aryl or aralkyl radical, preferably-C₁₃H₂₇Alkyl radical

Or

Two R¹Form a cyclic dialkoxy radical having from 2 to 10 carbon atoms, in which case o is<3，

Or two or more silanes of the formula I) may pass through the radical R¹Bridging; and is

Wherein the radicals R are intramolecular²May be the same or different and contains a straight-chain or branched alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 4 to 12 carbon atoms or an aryl group having 6 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms or a substituted or unsubstituted alkyl group having 4 to 12 carbon atomsAralkyl having 7 to 20 carbon atoms; and is

Wherein the groups X in the molecule may be identical to or different from each other and are selected from the groups-HNC (═ O) -, -C (═ O) NH-, -C (═ O) O-, -OC (═ O) NH-, -HNC (═ O) O-, -R-, -O³NC(＝O)NR³-、-R³NC(＝NR³)NR³-、-R³NC(＝S)NR³-, where the radicals R are in the radical X and in the molecule³May be the same or different and is selected from a hydrogen atom or at least one R as in each group X³Is a hydrogen atom for R²As defined; and is

Wherein the groups A in the molecule may be the same as or different from each other and are aromatic groups, and

wherein the groups Y in the molecule may be identical to or different from each other and are selected from the groups-HNC (═ O) -, -C (═ O) NH-, -C (═ O) O-, -OC (═ O) NH-, -HNC (═ O) O-, -R-, -O⁴NC(＝O)NR⁴-、-R⁴NC(＝NR⁴)NR⁴-、-R⁴NC(＝S)NR⁴-, where the radicals R are in the radical Y and in the molecule⁴May be identical or different and is selected from a hydrogen atom or at least one R as in each radical Y⁴Is a hydrogen atom for R²As defined; and wherein each m is independently an integer from 0 to 4, and wherein the silane may also be in the form of an oligomer formed by hydrolysis and condensation of a silane of formula I).

In contrast to the silanes known from the prior art, the compounds of the invention have a group-R²-X-A-Y-[A-Y-]_mThe silanes of-A-have relatively long and rigid spacers comprising at least two aromatic groups A and linking units X and Y. Thus, the present invention provides a novel silane. Surprisingly, the rubber mixtures comprising the silanes of the invention have a higher and thus improved stiffness, which is attributable in particular to the two aromatic groups A present in the spacer (i.e. at S) in combination with the linking units X and Y_kOn each side of the section). Thus, the rubber mixture of the present invention has an improved steering prediction index, and the vehicle of the present inventionThe tire in particular exhibits improved handling characteristics.

The silanes of the invention and their preferred embodiments are explained below. All aspects also apply to the rubber mixtures according to the invention and to the silanes in the vehicle tires according to the invention.

As shown in formula I), the general basic structure of the silanes is symmetrical, where S_kThe group is considered the central point. However, the various parts and parameters on both sides may differ, and thus the molecules need not be specifically mirror-symmetrical.

S_kThe moieties and parameters on both sides of the group are preferably the same, which allows for a relatively simple synthetic route.

In formula I), m on both sides may each independently assume a value from 0 to 4. Thus, the moiety [ A-Y-]May additionally be present on each of the two sides of the molecule or only on the sulphur moiety S_kThereby, the silane has three aromatic groups a on each side or only on one side, or may be repeated independently on one or both sides (wherein m ═ 2 or 3 or 4), with a corresponding increase in the number of aromatic groups a. According to a preferred embodiment of the invention, m is 0 on both sides, that is, preferably each m is 0. In the case of the inventive nature of the molecule, such a molecule is relatively simple to produce, i.e. two aromatic groups present on each side in combination with the linkages X and Y in the spacer, so that improved rigidity in the rubber mixture is achieved only in this connection.

As described for formula I), the groups X within the molecule may be identical to or different from each other and are selected from the groups-HNC (═ O) -, -C (═ O) NH-, -C (═ O) O-, -OC (═ O) NH-, -HNC (═ O) O-, -R³NC(＝O)NR³-、-R³NC(＝NR³)NR³-、-R³NC(＝S)NR³-, where the radicals R are in the radical X and in the molecule³May be the same or different and is selected from a hydrogen atom or at least one R as in each group X³Is a hydrogen atom for R²As defined.

The groups-HNC (═ O) -and-C (═ O) NH-Is a carboxamide group, where two different symbols are intended to express possible intra-molecular connectivity. It is thus conceivable, in the acid amide embodiment, for the nitrogen atom of the radical X to be associated with the aromatic radical A or the radical R²And (4) connecting.

The radicals-C (═ O) O-and-OC (═ O) -are ester groups, analogous to acid amide groups, where both symbols here are also referred to in respect of A and R²Different connectivity of (a).

The radicals-OC (═ O) NH-and-HNC (═ O) O-are urethane groups, analogous to acid amide groups, where both symbols here are also referred to in respect of A and R²Different connectivity of (a).

group-R³NC(＝O)NR³-represents a urea group, wherein the group R³At least one of which is a hydrogen atom.

group-R³NC(＝NR³)NR³-represents a guanidine group, wherein the group R³At least one of which is a hydrogen atom.

group-R³NC(＝S)NR³-represents a thiourea group, wherein the group R³At least one of which is a hydrogen atom.

Preferably, each R of each group X³Is a hydrogen atom.

For R in the formula³As for R²In the case of defined organic radicals, particular preference is given to R³Selected from alkyl groups having from 1 to 7 carbon atoms or aromatic groups having from 6 to 10 carbon atoms, such as, for example, phenyl groups.

Preferably, the group X is selected from the group consisting of-HNC (═ O) -, -C (═ O) NH-, -OC (═ O) NH-, -HNC (═ O) O-, -R³NC(＝O)NR³-、-R³NC(＝NR³)NR³-、-R³NC(＝S)NR³-, and in particular the use of the above for R³The specifications are given.

The radical X is particularly preferably selected from the groups-HNC (═ O) -, -C (═ O) NH-, -OC (═ O) NH-, -HNC (═ O) O-, -R³NC(＝O)NR³-, further preferably selected from the groups-HNC (═ O) -, -C (═ O) NH-, -R³NC(＝O)NR³-。

According to a particularly advantageous embodiment of the invention, X is identical on both sides of the molecule and is a urea group-HNC (═ O) NH-, wherein each R is³Hydrogen atom.

As described for formula I), the groups Y within the molecule may be identical to or different from each other and are selected from the groups-HNC (═ O) -, -C (═ O) NH-, -C (═ O) O-, -OC (═ O) NH-, -HNC (═ O) O-, -R⁴NC(＝O)NR⁴-、-R⁴NC(＝NR⁴)NR⁴-、-R⁴NC(＝S)NR⁴-, where the radicals R are in the radical Y and in the molecule⁴May be identical or different and is selected from a hydrogen atom or at least one R as in each radical Y⁴Is a hydrogen atom for R²As defined.

The statements made above with respect to X apply to the corresponding radicals.

Each R⁴Preference is also given to hydrogen atoms in the corresponding radicals. For R in the formula⁴As for R²In the case of defined organic radicals, particular preference is given to R⁴Selected from alkyl groups having from 1 to 7 carbon atoms or aromatic groups having from 6 to 10 carbon atoms, such as, for example, phenyl groups.

Preferably, the group Y is selected from the group consisting of-HNC (═ O) -, -C (═ O) NH-, -OC (═ O) NH-, -HNC (═ O) O-, -R⁴NC(＝O)NR⁴-、-R⁴NC(＝NR⁴)NR⁴-、-R⁴NC(＝S)NR⁴-, and in particular the use of the above for R⁴The specifications are given.

The radical Y is particularly preferably selected from the groups-HNC (═ O) -, -C (═ O) NH-, -OC (═ O) NH-, -HNC (═ O) O-, -R⁴NC(＝O)NR⁴-, further preferably selected from the groups-HNC (═ O) -, -C (═ O) NH-, -R³NC(＝O)NR³-。

According to a particularly advantageous embodiment of the invention, Y is identical on both sides of the molecule and is an acid amide group HNC (═ O) -or-C (═ O) NH-.

Preference is given here to the fact that the connectivity in the simple example (where m ═ 0) has the following appearance:

(R¹)_oSi-R²-X-A-HN-C(＝O)-A-S_k-。

according to this preferred embodiment, the nitrogen atom of the acid amide group on both sides of the molecule is attached to the aromatic group a connecting X and Y. This preferred embodiment is not limited to m ═ 0, but is valid for all combinations of two instances of m having values from 0 to 4.

The aromatic groups A can in principle be any aromatic groups, where A within the molecule and on each side of the molecule can be identical to or different from one another. The aromatic radical A may here contain heteroatoms and/or bear substituents (for the corresponding hydrogen atoms) on one or more atoms of the aromatic skeleton, in particular in addition to the substituents X, Y and S according to formula_kAnd (c) out.

The aromatic groups a are preferably selected from the group consisting of: phenyl, naphthyl, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl, quinolinyl, pyrrolyl, furanyl, thiophenyl, pyrazolyl, imidazolyl, thiazolyl, and oxazolyl groups.

In the case where m ═ 1 to 4, the group A links X and Y and also Y and S_kAnd also Y and Y, where in each case X, Y and S_kFormally also a substituent of the corresponding aromatic radical A.

The radicals mentioned may be attached to the corresponding aromatic radicals here via all conceivable atoms of the aromatic skeleton. In monocyclic aromatic systems having six atoms in the backbone, such as phenyl groups, this means, for example, that these groups can be arranged in para, meta or ortho position relative to one another.

According to a particularly advantageous embodiment of the invention, all a's on both sides of the molecule are phenyl groups.

According to a preferred embodiment of the invention, in the case where m is 1 to 4, X and Y and also Y and S_kAnd also Y and Y are each arranged in para position relative to one another on the corresponding aromatic radical A.

This results in an elongated molecular structure of the silane, especially in rubber mixtures, which can contribute to a further increase in its stiffness.

According to another preferred embodiment of the invention, in the case of m ═ 1 to 4, on the corresponding aromatic group a, X and Y and also Y and Y are arranged in para position with respect to one another, and Y and S are arranged in para position with respect to one another_kEach arranged in an adjacent position relative to each other.

This leads to a rigid molecular structure of the silane, especially in rubber mixtures, which can contribute to a further increase in its stiffness.

In the silyl radical (R)¹)_oSi-and the radicals R of the silanes of the invention on both sides of the molecule¹May be the same as or different from each other and is selected from alkoxy groups having 1 to 10 carbon atoms, cycloalkoxy groups having 4 to 10 carbon atoms, phenoxy groups having 6 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, alkyl groups having 1 to 10 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, alkynyl groups having 2 to 20 carbon atoms, aralkyl groups having 7 to 20 carbon atoms, a halide, or

Alkyl polyether radical-O- (R)⁶-O)_r-R⁵Wherein R is⁶Identical or different and branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic divalent C₁-C₃₀Hydrocarbyl, preferably-CH₂-CH₂-, R is an integer from 1 to 30, preferably from 3 to 10, and R⁵Is an unsubstituted or substituted, branched or unbranched, monovalent alkyl, alkenyl, aryl or aralkyl radical, preferably-C₁₃H₂₇Alkyl radical

Or

Two R¹Form a cyclic dialkoxy radical having 2 to 10 carbon atoms, where then o<3，

Or two or more silanes of the formula I) may pass through the radical R¹And (3) bridging.

All the radicals R mentioned¹And the connecting bonds may be combined with each other within the silyl group.

When two silanes of the formula I) are bridged to one another, they share the group R¹. It is also possible for more than two silanes to be present in this wayThis connection. After synthesis of the silanes of the formula I), it is therefore conceivable for two silanes of the formula I) to pass through the group R¹Are bridged to each other. It is also possible for more than two silanes to be linked to one another in this way, for example via a dialkoxy group.

The silanes of the invention may also comprise oligomers formed by hydrolysis and condensation of silanes of the formula I).

Silanes of the formula I) are preferably present in each silyl group (R)¹)_oSi-comprising at least one group R which can act as a leaving group¹Such as in particular alkoxy or any other mentioned group bonded to the silicon atom via an oxygen atom, or a halide.

Radical R¹Preferably 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.

According to a particularly advantageous embodiment of the invention, at 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 ═ 3.

However, including in the case of oligomers or if two R are present¹Forming dialkoxy, the remaining radical 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.

Intramolecular radical R of a silane according to the invention²May be the same as or different from each other, and is a straight-chain or branched alkyl group having 1 to 20 carbon atoms or a cycloalkyl group having 4 to 12 carbon atoms or an aryl group having 6 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms or an aralkyl group having 7 to 20 carbon atoms.

Radical R²Preference is given to straight-chain or branched alkyl radicals having from 2 to 8 carbon atoms or cycloalkyl radicals having from 4 to 8 carbon atoms, such as, in particular, cyclohexyl radicals.

According to a particularly advantageous embodiment of the invention, all radicals R within the molecule²Are identical and are alkyl radicals having from 2 to 6 carbon atoms, preferably from 2 to 4 carbon atoms, particularly preferably 2 or 3 carbon atoms, of which the propyl radical having 3 carbon atoms is very particularly preferred.

Part S_kIs a sulfur bridge consisting of k sulfur atoms, wherein the k sulfur atoms are linked together in a chain such that the molecule has a polysulfide moiety. The index k here is an integer greater than or equal to 2.

Preferably, k is an integer from 2 to 10 (including 2 and 10), particularly preferably from 2 to 8, very particularly preferably 2, 3 or 4.

As is known to the person skilled in the art, the disulfide moiety which has been obtained as a result of the synthesis can be converted into a polysulfide by means of vulcanization in a further process step by adding elemental Sulfur, resulting in a k of greater than or equal to 3, see in this respect Wang et al, Journal of sulfuration Chemistry, 2013,34, 55-66.

In principle, the sulfurization can also be carried out at an earlier stage of the process, such as in particular in the starting molecules in the synthesis, so that the molecules having the formula I) can be synthesized as polysulfides with k greater than or equal to 3.

According to a particularly advantageous embodiment of the invention, k is equal to 2 and therefore the molecule has a disulphide moiety.

In a particularly preferred and exemplary embodiment of the present invention, the silane of the present invention has the following formula II):

II)

in this case, with respect to formula I), m ═ 0, R¹All examples of (A) are ethoxy, R²Both examples of (a) are propyl groups, both examples of X are urea groups, all examples of a are phenyl groups, wherein all linkages are arranged in para position, and each example of Y is an acid amide group, the nitrogen atom of which is attached to the corresponding phenyl group in the direction of the urea group (X).

Silanes of the formula II) represent preferred embodiments of the invention. With this silane, particularly high stiffness and low resilience are achieved in the rubber mixtures of the invention. The latter therefore has improved handling and wet braking performance.

It is particularly preferred here that k is equal to 2, which leads to the above-mentioned advantages to a certain extent.

Exemplary and preferred silanes are shown in formula IV) where k ═ 2:

IV)

in another particularly preferred and exemplary embodiment of the invention, the silanes of the invention

In this case, with respect to formula I), m ═ 0, R¹All examples of (A) are ethoxy, R²Are both propyl groups, are both urea groups, are all phenyl groups, wherein S is compared to formula II)_kThe groups and the corresponding acid amide groups are arranged in ortho position relative to each other on the phenyl group.

Silanes of the formula III) represent preferred embodiments of the invention. With this silane, particularly high stiffness is achieved in the rubber mixtures according to the invention. Thus, the latter has an improved handling index.

It is particularly preferred here that k is equal to 2, which leads to the above-mentioned advantages to a certain extent.

Exemplary and preferred silanes are shown in formula V) where k ═ 2:

V)

the rubber mixtures according to the invention comprise at least one silane according to the invention. In principle, it is conceivable for the rubber mixture to comprise rubber mixtures from different embodimentsMixtures of a plurality of silanes of the invention, that is to say, possibly having different radicals X, Z, A, R¹、R²Possibly R³Different linkages to the aromatic group A and also different values of k and/or m. The rubber mixtures may also comprise mixtures of two or more silanes I), II), III), IV) or V). The rubber mixtures may also comprise the silanes of the invention of the formulae I) to V) shown in combination with other silanes known in the prior art.

Such coupling agents known from the prior art are bifunctional organosilanes which have at least one alkoxy, cycloalkoxy or phenoxy group as leaving group on the silicon atom and have a group as further functional group which can possibly enter into a chemical reaction with the double bond of the polymer after dissociation. The latter group may for example be the following chemical group:

-SCN、-SH、-NH₂or-Sx- (wherein x ═ 2 to 8).

For example, the silane coupling agent used may be 3-mercaptopropyltriethoxysilane,

3-thiocyanatopropyltrimethoxysilane or 3,3 '-bis (triethoxysilylpropyl) polysulfides having from 2 to 8 sulfur atoms, such as, for example, 3' -bis (triethoxysilylpropyl) tetrasulfide (TESPT), the corresponding disulfides (TESPD), or else mixtures of sulfides having from 1 to 8 sulfur atoms with various sulfide contents. TESPT may also be sold under the trade name of industrial carbon black (from Evonik, Inc.)

) The mixture of (a) is added.

Detailed Description

The invention will be explained in more detail below with reference to exemplary embodiments.

Silanes of the formula IV) as examples of the invention are prepared in the following manner:

1. preparation of bis (4-carboxyphenyl) disulfide according to the synthetic scheme of formula VI)

VI)

A saturated ethanolic iodine solution (25 ml total) was added dropwise to a solution of 4-mercaptobenzoic acid (7.50g, 48.6mmol, 1.0 equiv.) in ethanol (500ml, EtOH) at room temperature. Upon addition, the iodine solution was decolorized and the reaction mixture became turbid. The addition of iodine was continued until the resulting suspension obtained a pale yellow color due to excess iodine.

The reaction mixture was then filtered using a buchner funnel and the residue was washed with cold demineralised water (4 x 50ml) and cold ethanol (4 x 50ml) to remove excess iodine.

After drying under high vacuum, the title compound was isolated as a white powder (6.69g, 21.8mmol, 90%).

¹H NMR(500MHz,DMSO-d₆(ii) a Dimethylsulfoxide) delta 13.08(s,2H),7.97-7.88(m,4H),7.67-7.59(m, 4H).

¹³C NMR(126MHz,DMSO-d₆)δ167.22,141.16,130.83,130.31,126.54。

2. Preparation of 1- (4' -aminophenyl) -3- (3) according to the synthetic scheme of formula VII)”- (triethoxysilyl) propane Yl) urea

VII)

3- (isocyanatopropyl) triethoxysilane (11.44ml, 11.44g, 46.2mmol, 1.0 equiv.) is added dropwise to a solution of p-phenylenediamine (10.00g, 92.5mmol, 2.0 equiv.) in dichloromethane (300ml of DCM) at room temperature. After stirring overnight, the solvent was removed on a rotary evaporator to afford the crude product as a grey solid (21.57 g).

Purification by column chromatography was carried out on silica gel (DCM/EtOH 9:1) in small portions of about 3-4g each (yield of about 74% by weight in each case).

After drying under high vacuum, the title compound is isolated in the form of a pale gray powder (extrapolated for the total product: 15.96g, 44.9mmol, 97% based on silane).

¹H NMR(500MHz,DMSO-d₆)δ7.82(s,1H),6.98(d,J＝8.7Hz,2H),6.45(d,J＝8.7Hz,2H),5.91(t,J＝5.8Hz,1H),4.66(s,2H),3.74(q,J＝7.0Hz,6H),3.00(q,J＝6.8Hz,2H),1.48-1.39(m,2H),1.14(t,J＝7.0Hz,9H),0.57-0.49(m,2H)。

¹³C NMR(126MHz,DMSO-d₆)δ155.69,143.33,129.62,120.22,114.12,57.70,41.81,23.49,18.24,7.25。

3. Preparation of bis (4-carboxychlorophenyl) disulfide (bis (4- carboxylchloridophenyl) disulphide) (in situ)

VIII)

Dimethylformamide (0.1ml of DMF, catalyst) was added to a suspension of bis (4-carboxyphenyl) disulfide (1.96g, 6.4mmol, 1.0 eq) in tetrahydrofuran (60ml of THF). Oxalyl chloride (5.49ml, 8.12g, 64.0mmol, 10.0 equiv.) was added dropwise to the reaction mixture at 0 ℃ and the mixture was stirred at this temperature for 30 min. The resulting yellow solution was then stirred at room temperature for a further 3 h. The solvent and excess oxalyl chloride were then distilled off. A yellow solid was isolated which was used for the next synthetic step (due to its reactivity) without further analysis or purification.

4. Preparation of silanes of the formula II) according to the synthetic scheme of the formula IX)

IX)

A solution of bis (4-carboxychlorophenyl) disulfide (1.12g, 3.26mmol, 1.0 equiv.) in THF (40ml) was added dropwise to a solution of 1- (4-aminophenyl) -3- (3- (triethoxysilyl) propyl) urea (2.55g, 7.17mmol, 2.2 equiv.) and triethylamine (2.11ml, 1.65g, 16.3mmol, 5.0 equiv.) in THF (10ml) at room temperature over a period of 15 min. The resulting pale yellow suspension was then stirred overnight and then filtered. The filter cake was washed with cold THF (2X 10 ml). After drying under high vacuum, the title compound was isolated as a white powder (2.39g, 2.44mmol, 75%).

¹H NMR(500MHz,DMSO-d₆)δ10.13(s,2H),8.45(s,2H),7.94(d,J＝8.5Hz,4H),7.67(d,J＝8.6Hz,4H),7.56(d,J＝9.0Hz,4H),7.34(d,J＝9.0Hz,4H),6.23(t,J＝5.8Hz,2H),3.74(q,J＝7.0Hz,12H),3.03(q,J＝6.6Hz,4H),1.52-1.41(m,4H),1.14(t,J＝7.0Hz,18H),0.60-0.51(m,4H)。

¹³C NMR(126MHz,DMSO-d₆)δ164.32,155.34,139.05,136.78,134.16,132.49,128.75,126.38,121.10,117.79,57.80,56.12,41.84,23.45,18.31,7.32。

²⁹Si NMR(99MHz,DMSO-d₆)δ-44.52。

As another example of the present inventionOf silane V) ofThe preparation, that is to say of the silanes having ortho-bonded disulfide groups, proceeds in principle analogously to the preparation of silane IV). Therefore, only the differences are described below.

The synthesis starts from commercially available bis (2-carboxyphenyl) disulfide, which is converted to bis (2-carboxychlorophenyl) disulfide by means of oxalyl chloride according to scheme X):

X)

DMF (0.15ml, catalyst) was added to a suspension of bis (2-carboxyphenyl) disulfide (2.94g, 9.6mmol, 1.0 equiv.) in THF (60 ml). Oxalyl chloride (8.23ml, 12.19g, 96.0mmol, 10.0 equiv.) is added dropwise to the reaction mixture at 0 ℃ and the mixture is stirred at this temperature for 30 min. The resulting yellow solution was then stirred at room temperature for a further 3 h. The solvent and excess oxalyl chloride were then distilled off.

A yellow solid was isolated which was used for the next synthetic step (due to its reactivity) without further analysis or purification.

This was followed by reaction with 1- (4-aminophenyl) -3- (3- (triethoxysilyl) propyl) urea prepared as described above according to synthesis scheme XI).

A solution of bis (2-carboxychlorophenyl) disulfide (3.30g, 9.6mmol, 1.0 equiv.) in THF (80ml) was added dropwise over a period of 15min at room temperature to a solution of 1- (4-aminophenyl) -3- (3- (triethoxysilyl) propyl) urea (7.51g, 21.1mmol, 2.2 equiv.) and triethylamine (6.65ml, 4.86g, 48.0mmol, 5.0 equiv.) in THF (30 ml). The resulting pale yellow suspension was then stirred overnight and then filtered. The filtrate was concentrated and additional solid precipitated was filtered off again. The filter cake was washed with cold THF (2X 25ml) and demineralised water (2X 25 ml).

After drying under high vacuum, the title compound was isolated as a white powder (2.70g, 2.75mmol, 29%).

¹H NMR(500MHz,DMSO-d₆)δ10.41(s,2H),8.39(s,2H),7.76(d,J＝7.6Hz,1H),7.72(d,J＝8.1Hz,1H),7.60(d,J＝9.0Hz,3H),7.50(ddd,J＝8.5,7.4,1.5Hz,2H),7.40-7.34(m,6H),6.14(t,J＝5.7Hz,2H),3.75(q,J＝7.0Hz,12H),3.05(q,J＝6.6Hz,4H),1.54-1.42(m,4H),1.15(t,J＝7.0Hz,18H),0.63-0.51(m,4H)。

¹³C NMR(126MHz,DMSO-d₆)δ165.20,155.21,136.85,136.49,134.67,132.32,131.30,128.37,126.25,126.09,120.76,117.77,57.73,41.77,23.39,18.25,7.27。

²⁹Si NMR(99MHz,DMSO-d₆)δ-44.57。

The silanes prepared having the formula IV) and/or V) are mixed into the rubber mixtures according to the invention, which comprise at least one diene rubber and at least one silica as filler. For this purpose, the silanes of the formulae IV) and/or V) are preferably previously adsorbed onto silica and subsequently added to the rubber mixture in this form.

The adsorption onto silica is carried out, for example, as follows:

to a suspension of silica, e.g. particulate silica, in DMF, a solution of a silane of formula IV) and/or V) dissolved in DMF is added at room temperature at a desired silica/silane ratio. For example, 31.2g of silica (VN3, winning company) and 4.62g of silanes of the formula IV) and/or V) are used. The resulting suspension was stirred at 120 ℃ overnight and the solvent was subsequently removed under reduced pressure. After drying at 40 ℃ under high vacuum for one day, the modified silica thus obtained was pulverized with the aid of a mortar. It was then dried under high vacuum at 40 ℃ for another day.

For example, the rubber mixture of the invention is applied to a green tyre in the form of a pre-shaped tread of a vehicle tyre (as described above) and subsequently vulcanized together with the latter.

Exemplary rubber mixtures according to the invention comprising silanes of the formula IV) or V) are described below and compared with rubber mixtures comprising silanes known from the prior art. The compositions and results are summarized in table 1. The comparative mixture is identified with C and the inventive mixture is identified with I. In each case, the mixtures C1 and I1, and C2 and I2, and C3 and I3 and I4 contain equimolar amounts of silanes from the prior art (C1, C2, C3) or silanes IV) of the invention (I1, I2, I3) or silanes V) of the invention (I4).

In each case, the silane was adsorbed onto the silica (95 phr in each mixture) so that the silane-modified silica was mixed separately. Thus, the indicated amounts refer to the product of the modification reaction, wherein 95phr of silica is used in each mixture. The remaining amount (difference: table minus 95phr) thus represents the silane bound to the silica.

The mixture is furthermore produced in a laboratory mixer having a volume of 80ml to 3 l in two stages under standard conditions by the methods customary in the rubber industry, wherein in the first mixing stage (basic mixing stage) all the ingredients except the vulcanization system (sulfur and substances influencing vulcanization) are first mixed at 145 ℃ to 165 ℃ (where the target temperature is 152 ℃ to 157 ℃) for 200 to 600 seconds. The final mixture is produced by adding the vulcanization system in the second stage (last mixing stage), where mixing is carried out at 90 ℃ to 120 ℃ for 180 to 300 seconds.

At 160 ℃ underBy vulcanization under pressure to t₉₅All mixtures were used to produce test specimens (measured on a moving disk rheometer according to ASTM D5289-12/ISO 6502) and these test specimens were used to determine the material properties typical in the rubber industry by the test methods specified hereinafter.

Shore A hardness at room temperature according to ISO 868 (Sh A)

Rebound resilience at room temperature according to ISO 4662

Dynamic storage modulus E 'at 55 ℃ according to DIN 53513 at 0.15% and 6% elongation'

Stress values at 50%, 100%, 200%, 300% and 400% elongation at room temperature according to ISO 37 for the test specimen (dumbbell type 3)

The substances used were:

a) silicon dioxide: winning and creating company

VN3, in each case 95phr, the remainder in each case being bound silane

b) TESPD (3,3' -bis (triethoxysilylpropyl) disulfide)

c) Inventive silanes of the formula IV) prepared as described above

d) Inventive silanes of the formula V) prepared as described above

e) Ageing stabilizers, antiozonants waxes, zinc oxide, stearic acid

f) DPG and CBS.

As can be seen in table 1, the rubber mixtures I1 to I4 have a higher level of stiffness and have a higher hardness. According to exemplary embodiments of the present invention, that is to say mixtures comprising silanes prepared according to the invention, improved handling properties are therefore shown in particular.

Examples I1 to I3 of the invention comprising silanes according to formula IV) additionally have improved wet braking performance and lower rebound resilience (compared to C1 to C3).

TABLE 1