阅读说明：本技术 硅烷、含有该硅烷的橡胶混合物、在至少一个部件中包含该橡胶混合物的车辆轮胎、以及用于生产该硅烷的方法 (Silane, rubber mixture containing the silane, vehicle tire comprising the rubber mixture in at least one component, and method for producing the silane ) 是由 大卫-拉斐尔·道尔 尤利安·施特罗迈尔 安德里亚斯·雅各布 亚纳·于尔格斯 朱利安·达文 于 2020-03-25 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、以及一种用于生产该硅烷的方法。本发明的硅烷具有下式I)I)(R～(1))-(o)Si-R～(2)-S-R～(3)-S-R～(3)-S-X,其根据本发明包括-R～(2)-S-R～(3)-S-R～(3)-单元的间隔基团。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, and a method for producing the silane. The silane of the present invention has the following structureFormula I) I) (R) 1 ) o Si‑R 2 ‑S‑R 3 ‑S‑R 3 -S-X, which according to the invention comprises-R 2 ‑S‑R 3 ‑S‑R 3 -a spacer group of the unit. 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-S-R³-S-R³-S-X

wherein o may be 1,2 or 3, and R¹The groups may be the same or different and are 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, halogens, or alkyl polyether groups-O- (R) having 1 to 10 carbon atoms⁶-O)_r-R⁵Wherein R is⁶Identical or different and branched or unbranched, saturated or unsaturated, aliphatic, aromatic or mixed aliphatic/aromatic bridge C₁-C₃₀Hydrocarbyl, preferably-CH₂-CH₂-, R is an integer from 1 to 30, preferably 3 to 10, and R⁵Is an unsubstituted or substituted, branched or unbranched terminal alkyl, alkenyl, aryl or aralkyl radical, preferably-C₁₃H₂₇An alkyl group, a carboxyl group,

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 formula I) may be via R¹The radicals are bridged; and is

Wherein R is²And R³May be the same or different and is selected from the group consisting of: a linear or branched alkylene 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 X group is a hydrogen atom or-C (═ O) -R⁴Group or

-SiR⁷ ₃Group, wherein R⁴And R⁷Is selected from C₁-C₂₀Alkyl radical, C₄-C₁₀-cycloalkyl, C₆-C₂₀-aryl, C₂-C₂₀-alkenyl and C₇-C₂₀-aralkyl, and R⁷Further 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; and wherein the silane may also take the form of an oligomer formed via hydrolysis and condensation of the silane having the formula I).

2. The silane as claimed in claim 1, wherein R is³The groups are the same and are linear alkylene groups having from 1 to 20 carbon atoms, preferably from 2 to 10 carbon atoms, more preferably from 4 to 8 carbon atoms.

3. The silane according to one of the preceding claims, wherein the X group is-C (═ O) -R⁴Group, wherein R⁴Is selected from C₁-C₂₀-an alkyl group.

4. The silane according to any one of the preceding claims, wherein R is¹The radicals are identical or different and are alkoxy having 1 to 6 carbon atoms or halogen.

5. The silane of any one of the preceding claims, wherein R is²The group is a straight or branched chain alkylene group having 2 to 8 carbon atoms.

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

II)。

7. silica modified at least on its surface by at least one silane as claimed in any of claims 1 to 6.

8. A rubber mixture comprising at least one silane as claimed in any of claims 1 to 6 and/or at least one silica as claimed in claim 7.

9. A vehicle tire comprising in at least one component the rubber mixture as claimed in claim 8.

10. A process for preparing the silane as claimed in claim 1, comprising at least the following process steps:

a) providing a substance (R)¹)_oSi-R²-SH；

b) Providing the substance Cl-R³-Cl；

c) Reacting the substance from step a) with the substance from step b) in the presence of a base to obtain (R)¹)_oSi-R²-S-R³-Cl；

d) Bringing (R) from step c)¹)_oSi-R²-S-R³-Cl is reacted with a metal hydrosulfide (M-S-H) to obtain (R)¹)_oSi-R²-S-R³-SH, wherein M is a metal;

e) reacting (R) from step d)¹)_oSi-R²-S-R³-SH with a further moiety Cl-R³-Cl to obtain (R)¹)_oSi-R²-S-R³-S-R³-Cl；

f) Providing a substance M-S-X, wherein X is as defined in claim 1 and M is a metal;

g) making (R)¹)_oSi-R²-S-R³-S-R³-reacting Cl with M-S-X to obtain the silane having formula I): (R)¹)_oSi-R²-S-R³-S-R³-S-X；

h) Optionally purifying the silane of formula I) obtained in step g), wherein the two instances of M in steps d) and f) may be the same or different.

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, and a method for producing the silane.

Background

Silanes are known as additives for rubber mixtures, in particular for vehicle tires, and in particular specifically for rubber mixtures containing 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 a silane coupling agent is advantageous in terms of rolling resistance characteristics and workability of the rubber compound. To this end, the silanes typically have at least one sulfur moiety which participates in the vulcanization of the rubber mixture.

In principle it is possible to distinguish binding to only twoSilica or equivalent fillers and especially silanes having at least one silyl group for this purpose, with silanes having reactive sulfur moieties other than silyl groups, such as in particular S_xMoiety (wherein x>Or equal to 2) or mercapto groups S-H or blocked S-PG moieties (in which PG represents a protecting group) so that the silane can also pass through S in the sulfur vulcanization_xOr the reaction of the S-H moiety or the S-PG moiety after removal of the protecting group is bound to the polymer. The presence of-H or-PG may also be represented by X.

Furthermore, there is a change in the prior art of silyl groups with S_xOr the length of the spacer group between the S-X moieties. For example, EP 1375504B 1 discloses silanes having exactly one extended thioether unit within the spacer group.

Disclosure of Invention

The object of the present invention is to provide a novel silane and a rubber mixture containing the silane, by means of which a further improvement of the characteristic curves, including the rolling resistance characteristic, the grip characteristic (in particular wet grip), and the stiffness of the rubber mixture, in particular for use in vehicle tires, and thus a further improvement thereof, in particular of the steering prediction index, is achieved in comparison with the prior art.

This object is achieved by the silanes of the invention as claimed in claim 1, by silicas modified with the silanes of the invention, by the rubber mixtures of the invention comprising the silicas, and by the vehicle tires of the invention comprising the rubber mixtures of the invention in at least one part. The object is also achieved by a process for preparing the silanes as claimed in claim 10.

The silanes of the present invention have the following formula I):

I)(R¹)_oSi-R²-S-R³-S-R³-S-X，

wherein o can be 1,2 or 3, and R¹The groups may be the same or different and are 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, phenoxy groups having 6 to 6An aryl group of 20 carbon atoms, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aralkyl group having 7 to 20 carbon atoms, a halogen, 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 bridge C₁-C₃₀Hydrocarbyl, preferably-CH₂-CH₂-, R is an integer from 1 to 30, preferably 3 to 10, and R⁵Is an unsubstituted or substituted, branched or unbranched terminal alkyl, alkenyl, aryl or aralkyl radical, preferably-C₁₃H₂₇An alkyl group, a carboxyl group,

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) can be reacted via R¹The radicals are bridged; and is

Wherein R is²And R³May be the same or different and is selected from the group consisting of: a linear or branched alkylene 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 X group is a hydrogen atom or-C (═ O) -R⁴Group or

-SiR⁷ ₃Group, wherein R⁴And R⁷Is selected from C₁-C₂₀Alkyl radical, C₄-C₁₀-cycloalkyl, C₆-C₂₀-aryl, C₂-C₂₀-alkenyl and C₇-C₂₀-aralkyl, and R⁷Further 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; and wherein the silane may also take the form of an oligomer formed via hydrolysis and condensation of the silane having formula I).

having-R in comparison with the silanes known from the prior art²-S-R³-S-R³The silanes of the invention of the group have a relatively long spacer group comprising two thioether units. Thus, the present invention provides a novel silane. The rubber mixtures containing the silanes according to the invention have optimized characteristic curves including rolling resistance characteristics and stiffness. The rubber mixtures according to the invention therefore exhibit certain improvements in the characteristic curves including the steering predictors, and the vehicle tires according to the invention in particular exhibit improved steering characteristics.

The silanes of the invention and their preferred embodiments are explained below. Unless explicitly stated otherwise, all aspects also apply to the silanes in the rubber mixtures of the invention and in the vehicle tires of the invention, and to the preparation process.

In the context of the present invention, the terms "radical" and "group" are used synonymously in connection with a chemical formula component.

As shown in formula I), the silanes of the invention are blocked mercaptosilanes having S — X moieties, where X, due to its specified nature, is a hydrogen atom or a protecting group, so that the sulfur is then activated as described at the outset by removal of the protecting group so as to be able to participate in sulfur vulcanization.

The X radical being a hydrogen atom or-C (═ O) -R⁴A radical or-SiR⁷ ₃Group, wherein R⁴And R⁷Is selected from C₁-C₂₀Alkyl radical, C₄-C₁₀-cycloalkyl, C₆-C₂₀-aryl, C₂-C₂₀-alkenyl and C₇-C₂₀-aralkyl, and R⁷And is further 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.

In a particularly advantageous embodiment of the invention, X is — C (═ O) -R⁴A radical or-SiR⁷ ₃This means that in these advantageous embodiments the silane of the invention is a blocked mercaptosilane. This has the following advantages: only in the removal of the pairThe sulfur can only take part in the chemical reaction after the group mentioned for X and no unwanted side reactions occur beforehand. Thus, silanes are easier to process and, in particular, are easier to incorporate into rubber mixtures.

More preferably, the X group is-C (═ O) -R⁴Group, wherein R⁴Is selected from C₁-C₂₀-an alkyl group.

Where R is⁴Most preferably selected from C₁To C₇-alkyl, preferably in turn C₁-C₃Alkyl, especially C₁Alkyl, i.e. methyl.

Silyl group (R) of silane of the invention¹)_oR in Si-¹The groups may be the same or different and are selected from alkoxy having 1 to 10 carbon atoms, cycloalkoxy having 4 to 10 carbon atoms, phenoxy having 6 to 20 carbon atoms, aryl having 6 to 20 carbon atoms, alkyl having 1 to 10 carbon atoms, alkenyl having 2 to 20 carbon atoms, alkynyl having 2 to 20 carbon atoms, aralkyl having 7 to 20 carbon atoms, halogen, 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 bridge C₁-C₃₀Hydrocarbyl, preferably-CH₂-CH₂-, R is an integer from 1 to 30, preferably 3 to 10, and R⁵Is an unsubstituted or substituted, branched or unbranched terminal alkyl, alkenyl, aryl or aralkyl radical, preferably-C₁₃H₂₇An alkyl group, a carboxyl group,

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 formula I) may be via R¹The radicals are bridged.

All of the enumerated R¹The groups and linkages may be combined with each other within a silyl group.

When two haveWhen the silanes of the formula I) are bridged to one another, they share R¹A group. It is also possible for more than two silanes to be connected to one another in this way. After synthesis of the silanes of the formula I), it is therefore conceivable for two silanes of the formula I) to be present via R¹The radicals are bridged to one another. It is also possible for more than two silanes to be connected 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). This includes, firstly, oligomers of two or more silanes of the formula I). Secondly, according to the invention, this also includes oligomers formed by condensation of at least one silane of the formula I) with at least one further silane which does not conform to the formula I). The "further silane" may in particular be a silane coupling agent known to the person skilled in the art.

In an advantageous embodiment, in particular for the use of silanes in silica-containing rubber mixtures, a silane of the formula I) is present in each silyl group (R)¹)_oSi-comprising at least one R which can be used as a leaving group¹A group such as in particular an alkoxy group or any other mentioned group bonded to the silicon atom through an oxygen atom, or a halogen.

R¹The group preferably comprises an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, or a halogen, more preferably an alkoxy group having 1 to 6 carbon atoms, or a halogen.

In a particularly advantageous embodiment of the invention, in the silyl radical (R)¹)_oR in Si-¹The radicals are identical and are alkoxy having 1 or 2 carbon atoms, i.e. methoxy or ethoxy, most preferably ethoxy, where o ═ 3.

But even in the case of oligomers or if two R are present¹Forming dialkoxy, then remaining R¹The group is preferably an alkyl group having 1 to 6 carbon atoms or a halogen or an alkoxy group having 1 to 6 carbon atoms (preferably 1 or 2 carbon atoms), i.e. a methoxy or ethoxy group, most preferably an ethoxy group.

R of the silanes of the invention²And R³The groups may be the same or different within the molecule and are selected from the group consisting of: a linear or branched alkylene 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.

Preferably, R is³The radicals are identical or different and are straight-chain or branched alkyl radicals having from 1 to 20 carbon atoms, preferably from 1 to 10 carbon atoms, more preferably from 2 to 6 carbon atoms, in particular, for example, 6 carbon atoms, or cycloalkyl radicals having from 4 to 8 carbon atoms.

In a particularly advantageous embodiment, R³The groups are identical and are linear alkylene groups having from 1 to 20 carbon atoms, preferably from 2 to 10 carbon atoms, more preferably from 4 to 8 carbon atoms, especially for example 6 carbon atoms.

Preferably, R is²The group is a linear or branched alkylene group having 2 to 8 carbon atoms or a cycloalkyl group having 4 to 8 carbon atoms, such as in particular cyclohexyl.

In a particularly advantageous embodiment of the invention, R²Is a straight-chain or branched alkylene group having from 2 to 8 carbon atoms, preferably having from 2 to 6 carbon atoms, more preferably having from 2 to 4 carbon atoms, particularly preferably having 2 or 3 carbon atoms, very particularly preferably a propylene group having, for example, 3 carbon atoms.

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

II)。

herein, for formula I), o ═ 3, all R¹Is ethoxy, R²Is propylene, X is-C (═ O) -R⁴Wherein R is⁴Is methyl and R³The radical is hexylene.

Silanes of the formula II) constitute preferred embodiments of the invention. This achieves a particularly good characteristic curve for achieving the technical object.

The present invention further provides a process for preparing the silanes of the invention of the formula I). The method of the invention comprises at least the following method steps:

a) providing a substance (R)¹)_oSi-R²-SH；

b) Providing the substance Cl-R³-Cl；

c) Reacting the material from step a) with the material from step b) in the presence of a base to obtain (R)¹)_oSi-R²-S-R³-Cl；

d) Bringing (R) from step c)¹)_oSi-R²-S-R³-Cl is reacted with a metal hydrosulfide (M-S-H) to obtain (R)¹)_oSi-R²-S-R³-SH, wherein M is a metal;

e) reacting (R) from step d)¹)_oSi-R²-S-R³-SH with a further moiety Cl-R³-Cl to obtain (R)¹)_oSi-R²-S-R³-S-R³-Cl；

f) Providing a substance M-S-X, wherein X is as defined in claim 1 and M is a metal;

g) making (R)¹)_oSi-R²-S-R³-S-R³-Cl is reacted with M-S-X to obtain a silane having formula I): (R)¹)_oSi-R²-S-R³-S-R³-S-X；

h) Optionally purifying the silane of formula I) obtained in step g), wherein the two instances of M in steps d) and f) may be the same or different.

For R¹、R²、R³The above description applies to the radicals and o and X, unless explicitly stated otherwise.

The materials in steps a) and b) may be obtained and provided commercially.

The reaction in step c) is preferably carried out in an organic solvent, for example ethanol, especially if at least one R is present¹The radicals being ethoxy, or methanol, especially if at least one R is¹The radical is methoxy.

The reaction in step c) is preferably carried out under a protective gas atmosphere, e.g. argon, and at elevated temperatures, e.g. 60 ℃ to 90 ℃.

Preferably, first, the formula (R)¹)_oSi-R²-SH (e.g. 3- (mercaptopropyl) triethoxysilane) with a base such as in particular sodium ethoxide (especially when at least one R is present)¹Is an ethoxy group) and deprotonation is caused on the sulfur atom, in particular by heating for several hours, for example from 1 to 12 hours.

After deprotonation is complete, it can be cooled to Room Temperature (RT) and then the cooled ethanolic solution of the thiolate obtained after deprotonation is added dropwise to Cl — R³-Cl (e.g. 1, 6-dichlorohexane) and stirring at elevated temperature, e.g. 60 to 90 ℃, for several hours, e.g. 2 to 12 hours.

Subjecting the reaction product (R) obtained in step c)¹)_oSi-R²-S-R³-Cl is separated according to its state of matter and then purified.

In step d), carrying out (R) from step c)¹)_oSi-R²-S-R³Reaction of-Cl with M-S-H for example and preferably with sodium hydrosulfide (NaSH) to give (R)¹)_oSi-R²-S-R³-SH。

Hydrosulfides, such as sodium hydrosulfide, are especially anhydrous.

The reaction is preferably carried out in a polar aprotic organic solvent, such as Dimethylformamide (DMF), and while heating to, for example, 50 ℃ to 70 ℃, within hours, such as 2 to 12 hours.

After cooling, the solvent is removed and the reaction product (R) is extracted, for example by means of ethyl acetate¹)_oSi-R²-S-R³-SH and purification.

In step e), the (R) from step d) is reacted¹)_oSi-R²-S-R³-SH with another moiety Cl-R³-Cl to obtain (R)¹)_oSi-R²-S-R³-S-R³-Cl。

The reaction conditions as described in connection with step c) apply analogously here.

Separation ofAnd purifying the reaction product (R)¹)_oSi-R²-S-R³-S-R³-Cl。

In step f), providing a substance M-S-X, wherein X is as defined in claim 1 and M is a metal, wherein the metals are independently selected from the metals from step d). For example, and in a preferred embodiment, K-S-X is used in step f), wherein K represents potassium.

An example material is potassium thioacetate, which is commercially available and thus provided.

In step g), reacting (R)¹)_oSi-R²-S-R³-S-R³-Cl is reacted with K-S-X to obtain a silane having formula I): (R)¹)_oSi-R²-S-R³-S-R³-S-X。

The reaction is preferably carried out in a polar aprotic organic solvent, such as Dimethylformamide (DMF), and while heating to, for example, 40 ℃ to 60 ℃, within hours, such as 2 to 12 hours.

After cooling, the solvent is removed and the reaction product having formula I) is extracted:

I)(R¹)_oSi-R²-S-R³-S-R³-S-X

for example, by ethyl acetate, and purified.

In process step h), the silane of the formula I) obtained in step g) is optionally purified, the nature of the purification being determined by the state of the substance in which the silane is obtained.

However, it is also conceivable that the prepared silane is further used, for example absorbed onto silica, without purification steps, as described below.

The invention further provides a silica which has been modified at least on its surface by at least one silane according to the invention.

By way of example, the modification is achieved by at least the following method steps:

i) optionally dissolving the silane of the invention having the formula I) from step g) or h) in an organic solvent;

j) contacting at least one silica with the silane from step g) or h) or the solution from step i), and then stirring the resulting suspension, preferably for 30 minutes to 18 hours;

k) the obtained modified silica was dried.

The silica may be any silica known to the person skilled in the art, such as in particular the silica types listed in detail below.

These further process steps constitute the modification of the silica with the silanes prepared according to the invention and are a further aspect of the invention.

The rubber mixtures according to the invention comprise at least one silane according to the invention having the formula I). In principle, it is conceivable that the rubber mixtures comprise a plurality of inventive silanes from different examples, i.e. it is possible to have different groups X, and R in the mixture¹、R²And R³. The rubber mixtures may also comprise mixtures of two or more silanes I) or II), in particular. The rubber mixtures may also comprise the silanes of the invention of the formula I) or II) shown in combination with other silanes known in the art, optionally as oligomers as described above.

Such coupling agents known from the prior art are, in particular and for example, bifunctional organosilanes which have at least one alkoxy, cycloalkoxy or phenoxy group as leaving group on the silicon atom and have, as further functional group, a 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-thiocyanopropyltrimethoxysilane or a 3,3 '-bis (triethoxysilylpropyl) polysulfide having 2 to 8 sulfur atoms, such as 3,3' -bis (triethoxysilylpropyl) tetrasulfide (TESPT), the corresponding disulfide (TESPD) or else a mixture of sulfides having 1 to 8 sulfur atoms, with different contents of the various sulfur atomsCompound (ii). TESPT may also be, for example, available under the trade name carbon black (from Evonik corporation)) The mixture of (1) is added.

The prior art also discloses a silane mixture containing 40 to 100% by weight of disulfide, more preferably 55 to 85% by weight of disulfide, and most preferably 60 to 80% by weight of disulfide. Such a mixture is, for example, available under the trade name Si from winning-from-CreditThe mixtures are obtainable, for example, as described in DE 102006004062A 1.

Blocked mercaptosilanes, as are known, for example, from WO 99/09036, may also be used as silane coupling agents. It is also possible to use silanes as described in WO 2008/083241 a1, WO 2008/083242 a1, WO 2008/083243 a1 and WO2008/083244a 1. Useful silanes are, for example, those sold under the name NXT (e.g.3- (octanoylthio) -1-propyltriethoxysilane) in a number of variations by Momentive, USA, or VP Si by the winning Industrial company (Evonik Industries)Those sold under the name.

The silanes mentioned at the outset which have exactly one thioether unit in the spacer radical may also be present.

In a particularly advantageous embodiment of the invention, the rubber mixture contains a silane of the formula II).

The rubber mixtures of the invention are preferably rubber mixtures suitable for use in vehicle tyres and for this purpose preferably contain at least one diene rubber.

Diene rubbers are rubbers formed by polymerization or copolymerization of dienes and/or cycloolefins and thus have C ═ C double bonds in the main chain or in side groups.

The diene rubber is selected fromThe 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 isoprene-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.

Nitrile rubber, hydrogenated acrylonitrile-butadiene rubber, chloroprene rubber, butyl rubber, halobutyl rubber or ethylene-propylene-diene rubber are used in particular for the production of technical rubber articles, such as belts, drive belts and hoses, and/or shoe soles.

Preferably, the diene rubber is selected from the group consisting of: natural polyisoprene and/or synthetic polyisoprene and/or butadiene rubber and/or solution polymerized styrene-butadiene rubber and/or emulsion polymerized styrene-butadiene rubber.

In a preferred development of the invention, at least two different types of diene rubbers are used in the rubber mixture.

The rubber mixtures according to the invention preferably contain at least one silica as filler, which in particular brings about the advantages of the silanes according to the invention.

If the at least one silane of the invention is added to the rubber mixture of the invention to which silica has been applied, the rubber mixture can contain further silica.

The terms "silicic acid" and "silica" are used synonymously in the context of the present invention.

The silica may be silica known to those skilled in the art to be suitable as a filler for tire rubber compounds.However, the use of finely divided precipitated silicas having a particle size of from 35 to 400m is particularly preferably taken into consideration²G, preferably 35 to 350m²G, more preferably from 100 to 320m²G and most preferably 100 to 235m²Nitrogen surface area (BET surface area) in g (according to DIN ISO 9277 and DIN 66132), and from 30 to 400m²G, preferably 30 to 330m²G, more preferably 95 to 300m²G and most preferably 95 to 200m²CTAB surface area in g (according to ASTM D3765).

Such silicas give rise to rubber mixtures, for example for internal tire components, giving rise to particularly good physical properties of the vulcanizates. Advantages in the processing of the mixture by reducing the mixing time can also arise here, while retaining the same product properties, which leads to improved productivity. Thus, examples of silicas that may be used include silicas not only from the winning companiesVN3 (trade name), and also silicas having a relatively low BET surface area (e.g. from Solvay)1115 or1085) And highly dispersible silicas, known as HD silicas (for example from Solvay corporation)1165MP)。

The amount of at least one silica here is preferably from 5 to 300phr, more preferably from 10 to 200phr, most preferably from 20 to 180 phr. In the case of different silicas, the indicated amounts refer to the total amount of silica present.

The unit "phr" (parts per hundred parts of rubber by weight) used in this document is a conventional indication of the amount of mixture formulation in the rubber industry. The dosage of parts by weight of these individual substances is herein based on 100 parts by weight of the total mass of all high molecular weights (Mw greater than 20000 g/mol) present in the mixture and hence of the solid rubber.

The designation "phf" (parts per hundred parts filler by weight) as used herein is a conventional designation for the amount of coupling agent used for fillers in the rubber industry. In the context of the present application phf refers to the presence of silica, meaning that any other filler (such as carbon black) present is not included in the calculation of the amount of silane.

The rubber mixtures of the invention preferably comprise at least one silane of the formula I), preferably at least one silane of the formula II), in an amount of from 1 to 25phr and, preferably, silica as filler, preferably from 2 to 20 phf.

The silane or silanes of the invention are preferably added in at least one basic mixing stage during the production of the rubber mixtures of the invention, which preferably contain at least one diene rubber and preferably at least one silica as filler.

The present invention therefore further provides a process for producing the rubber mixtures according to the invention, wherein at least one silane according to the invention as described above is added, preferably in at least one basic mixing stage.

In an advantageous embodiment of the invention, the at least one silane according to the invention is previously adsorbed onto silica and mixed in this form into the rubber mixture.

In the process according to the invention for producing the rubber mixtures according to the invention, it is therefore preferred that the at least one silane according to the invention is previously adsorbed onto silica and is incorporated in this form into the rubber mixture.

The rubber base mixture comprising at least one silane of the invention and/or one silica of the invention is subsequently processed by adding vulcanization chemicals (see below), in particular a sulfur vulcanization system, to give a finished rubber mixture and then vulcanized, which provides the vulcanized rubber of the invention of the rubber mixture of the invention.

Further aspects of the invention are the production of base rubber mixtures comprising at least one silane of the invention and/or one silica of the invention and the production of finished rubber mixtures comprising at least one silane of the invention and/or one silica of the invention and the production of vulcanizates of the invention of the rubber mixtures of the invention.

The rubber mixtures of the invention may contain carbon black as further filler, in particular in an amount of preferably from 2 to 200phr, more preferably from 2 to 70 phr.

The rubber mixtures of the invention may contain further fillers, preferably in very small amounts, i.e. preferably from 0 to 3 phr. In the context of the present invention, further (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).

Furthermore, optional reinforcing fillers are for example carbon nanotubes ((CNTs), including discrete CNTs, 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.

The rubber mixtures may further contain conventional additives in conventional parts by weight, which are preferably added during the production of the mixtures in at least one basic mixing stage. These additives include

a) Aging stabilizers, 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 such as zinc oxide and fatty acids (e.g., stearic acid) and/or other activators such as zinc complexes, e.g., zinc ethylhexanoate,

c) an antiozonant wax which is a mixture of an antiozonant wax,

d) resins, particularly tackifying resins for internal tire components,

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) plasticizers, such as in particular aromatic, naphthenic or paraffinic mineral oil plasticizers, for example MES (mild extraction solvate) or RAE (residual aromatic extract) or TDAE (treated distillate aromatic extract), or liquid Rubber (RTL) or liquid Biomass (BTL) oils, preferably having a polycyclic aromatic hydrocarbon 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, the average molecular weight of which (determined by GPC ═ gel permeation chromatography using the method based on BS ISO 11344: 2004) is between 500 and 20000g/mol, with mineral oils being particularly preferred as plasticizers.

When mineral oil is used, it 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.

The total proportion of further additives is preferably from 3 to 150phr, more preferably from 3 to 100phr and most preferably from 5 to 80 phr.

Zinc oxide (ZnO) may be included in the total proportion of additional additives in the above amounts.

This may be any type of zinc oxide known to those skilled in the art, such as ZnO pellets or powder. 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".

The vulcanization of the rubber mixtures of the invention is preferably carried out in the presence of sulfur and/or sulfur donors by means of vulcanization accelerators, some of which may simultaneously act as sulfur donors. 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 a 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) or guanidine accelerators such as Diphenylguanidine (DPG).

The sulfur donor material used may be any sulfur donor material known to those skilled in the art. If the rubber mixture contains a sulfur donor substance, the latter 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 dipentamethylenethiuram tetrasulfide (DPTT)

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.

Additional network-forming systems, such as, for example, those under the trade nameOrThe network-forming systems available below, or described for example in WO 2010/049216 a2, can also be used in rubber mixtures. This system contains a vulcanizing agent crosslinked with a functionality greater than four and at least one vulcanization accelerator.

It is particularly preferred to use the accelerators TBBS and/or CBS and/or Diphenylguanidine (DPG).

Vulcanization retarders may also be present in the rubber mixture.

The terms "vulcanized" and "crosslinked" are used synonymously in the context of the present invention.

In a preferred development of the invention, accelerators are added in the final mixing stage during the production of the sulfur-crosslinkable rubber mixture.

The sulfur-crosslinkable rubber mixtures according to the invention are produced by the processes customary in the rubber industry, in which a base mixture comprising all the constituents except the vulcanization system (sulfur and substances which influence vulcanization) is first produced in one or more mixing stages. The final mixture is produced by adding the vulcanization system in the final mixing stage. For example, the final mixture is further processed and brought into the appropriate shape by means of an extrusion operation or calendering.

This is followed by further processing by vulcanization, wherein sulfur crosslinking takes place due to the addition of a vulcanization system in the context of the present invention.

The rubber mixtures according to the invention are particularly suitable for use in vehicle tyres, in particular pneumatic vehicle tyres. In principle, the application in all tire components is conceivable here, in particular in the tread, in particular in the crown of a tread of the crown/base construction.

Here the crown is the part of the tread of the vehicle tyre that is in contact with the running surface, while the base is the inner part of the tread that is radially below the crown and that is not in contact with the running surface.

For use in vehicle tyres, the mixture, which is the final mixture before vulcanization, is preferably brought into the shape of the tread and applied in a known manner during the production of a green vehicle tyre.

The production of the rubber mixtures of the invention is carried out as already described, the rubber mixtures being used as sidewalls or other body mixtures for vehicle tires. The difference is the formation after the extrusion operation/calendering of the mixture. The shape of the unvulcanized rubber mixture thus obtained for one or more different body mixtures is then used for the building of a green tyre.

By "body mix" is meant here a rubber mix for the inner components of the tire, such as mainly the squeegee, the inner liner (inner layer), the ring core profile, the belt, the shoulder, the belt profile, the carcass, the bead reinforcement, the bead profile, the flange profile and the belt. The green tyre, which has not been vulcanized, is then vulcanized.

For the use of 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.

The invention further provides a vehicle tire comprising in at least one component the rubber mixture according to the invention, which contains at least one silane according to the invention.

Vulcanized vehicle tires comprise at least one vulcanized rubber of the rubber mixtures of the invention in at least one component. It is known to the person skilled in the art that most substances, such as the rubbers and silanes present, in particular the silanes of the invention, are already present in chemically modified form after mixing or only after vulcanization.

In the context of the present invention, "vehicle tire" is understood to mean vehicle pneumatic tires and solid rubber tires, including tires for industrial and construction site vehicles, trucks, automobiles, and two-wheeled vehicle tires.

The vehicle tire of the invention preferably comprises the rubber mixture of the invention at least in the tread.

The vehicle tire of the invention preferably comprises the rubber mixture of the invention at least in the sidewall.

The rubber mixtures according to the invention are also suitable for other components of vehicle tires, such as, in particular, flange profiles, and also internal tire components. Furthermore, the rubber mixtures according to the invention are also suitable for other industrial rubber products, such as bellows, conveyor belts, air springs, belts, drive belts or hoses, and also shoe soles.

Detailed Description

The present invention will be explained in detail below with reference to working examples. Silanes of the formula III) as examples according to the invention are prepared in the following manner:

1. preparing (3- ((6-chlorohexyl) thio) propyl) triethoxysilane according to the synthetic scheme of formula III); (EtO) _{3 2 3 2 6} Si(CH)S(CH)Cl

III)

To a solution of sodium ethoxide (12.84g, 189.0mmol, 1.0 equiv.) in ethanol (60mL) was added dropwise 3- (mercaptopropyl) triethoxysilane (45.6mL, 45.00g, 189.0mmol, 1.0 equiv. (eq.) over 5min at 60 ℃ under argon atmosphere. Subsequently, the orange reaction mixture was heated at reflux for 3h to complete deprotonation and then allowed to cool back to Room Temperature (RT). The ethanolic thiolate solution was transferred to the dropping funnel and added dropwise to 1, 6-dichlorohexane (110.0mL, 117.0g, 755.0mmol, 4.0 equiv.) over 30min at 80 ℃. The resulting suspension was then stirred at 80 ℃ overnight. The resulting white solid (NaCl) was filtered off through a buchner funnel and the target molecule was purified by fractional distillation. The target compound was isolated as a second fraction (0.3 mbar at about 140 ℃) in the form of a pale yellow liquid (34.3g, 96.0mmol, 51%).

¹H NMR (Nuclear magnetic resonance) (500MHz, DMSO-d)₆)δ3.75(q,J＝7.0Hz,6H,-SiOCH ₂CH₃),3.62(t,J＝6.6Hz,2H,-CH₂Cl),2.47(dd,J＝14.9,7.5Hz,4H,-SCH₂-),1.71(dq,J＝8.0,6.6Hz,2H,-SiCH₂CH ₂CH₂-),1.62-1.49(m,4H,-CH₂-),1.42-1.33(m,4H,-CH₂-),1.15(t,J＝7.0Hz,9H,-SiOCH₂CH ₃),0.70-0.64(m,2H,-SiCH ₂CH₂CH₂-)。

¹³C NMR(126MHz,DMSO-d₆)δ57.72,45.34,34.03,31.98,30.85,29.11,27.47,25.90,18.23,9.24。

ESI-MS (electrospray ionization mass spectrometry) m/z (%): 311.13[ M + H-EtOH]⁺(100)。

2. Preparing (3- ((6-mercaptohexyl) thio) propyl) triethoxysilane according to the synthesis scheme of formula IV); (EtO) _{3 2 3 2 6} Si(CH)S(CH)SH

IV)

To a solution of anhydrous sodium hydrosulfide (NaHS) (3.77g, 67.2mmol, 1.2 equiv.) in Dimethylformamide (DMF) (40mL) was added dropwise (3- ((6-chlorohexyl) thio) propyl) triethoxysilane (20.00g, 56.0mmol, 1.0 equiv.) at 60 ℃ under argon atmosphere over a period of 10 min.

The resulting suspension was then stirred at 60 ℃ overnight.

After cooling to room temperature, the solvent was removed under reduced pressure, and the residue was dissolved in demineralized water (50mL) and extracted with ethyl acetate (3 × 50 mL). The combined organic phases were washed with demineralized water (50mL) and dried over sodium sulfate, and the solvent was removed under reduced pressure.

After purification by silica gel column chromatography (120g, cyclohexane/ethyl acetate 0% → 5%), the title compound (11.15g, 31.4mmol, 56%) was isolated as a colorless liquid.

¹H NMR(500MHz,DMSO-d₆)δ3.74(q,J＝7.0Hz,6H,-SiOCH ₂CH₃),2.49-2.43(m,6H,-SCH₂-),2.19(t,J＝7.7Hz,1H,-SH),1.60-1.46(m,6H,-CH₂-),1.36-1.29(m,4H,-CH₂-),1.15(t,J＝7.0Hz,9H,-SiOCH₂CH ₃),0.69-0.63(m,2H,-SiCH ₂CH₂CH₂-)。

¹³C-NMR (126MHz, chloroform-d) delta 58.48,35.25,33.98,31.94,29.65,28.42,28.06,24.67,23.32,18.42, 9.99.

ESI-MS m/z(％)：309.14[M+H-EtOH]⁺(100)。

3. Preparation of 1- (1-thio-3- (triethoxysilyl) propyl) -6- (1-thio) according to the synthetic scheme of formula V) _{3 2 3 2 6 2 6}6-chlorohexyl) hexane; (EtO) Si (CH) S (CH) Cl

V)

To a solution of sodium ethoxide (0.77g, 11.3mmol, 1.0 equiv) in ethanol (40mL) was added (3- ((6-mercaptohexyl) thio) propyl) triethoxysilane (4.00g, 11.3mmol, 1.0 equiv) at 60 ℃ under argon atmosphere. Subsequently, the reaction mixture was heated at 80 ℃ for 3h to complete deprotonation, and then allowed to cool back to room temperature.

The ethanolic thiolate solution was transferred to the dropping funnel and added dropwise to 1, 6-dichlorohexane (19.7mL, 20.99g, 135.0mmol, 12.0 equiv.) over 15min at 80 ℃. The resulting suspension was then stirred at 80 ℃ overnight.

The resulting white solid (NaCl) was filtered off via a Buchner funnel and the excess 1, 6-dichlorohexane was removed under reduced pressure.

After purification by silica gel column chromatography (80g, cyclohexane/ethyl acetate 0% → 5%), the title compound (2.30g, 4.9mmol, 43%) was isolated as a colorless oil.

¹H NMR(500MHz,DMSO-d₆)δ3.75(q,J＝7.0Hz,6H,-SiOCH ₂CH₃),3.62(t,J＝6.6Hz,2H,-CH₂Cl),2.49-2.43(m,8H,-SCH₂-),1.71(dq,J＝7.9,6.5Hz,2H,-SiCH₂CH ₂CH₂-),1.61-1.46(m,8H,-CH₂-),1.42-1.31(m,8H,-CH₂-),1.15(t,J＝7.0Hz,9H,-SiOCH₂CH ₃),0.69-0.63(m,2H,-SiCH ₂CH₂CH₂-)。

¹³C NMR(126MHz,DMSO-d₆)δ57.64,45.21,34.03,31.93,31.04,30.99,30.89,29.11,29.02,28.97,27.75,27.40,25.83,22.90,18.14,9.21。

ESI-MS m/z(％)：427.19[M+H-EtOH]⁺(100),490.26[M+Na]⁺(10)。

4. Preparation of silane 1- (1-thio-3- (triethoxysilane) having the formula II) according to the synthetic scheme of the formula VI) _{3 2 3 2 6 2 6}Yl) propyl) -6- (1-thio-6-thioacetyl hexyl) hexane; (EtO) Si (CH) S (CH) SAc

VI)

To a solution of potassium thioacetate (1.20g, 10.5mmol, 1.5 equiv.) in DMF (20mL) was added 1- (1-thio-3- (triethoxysilyl) propyl) -6- (1-thio-6-chlorohexyl) hexane (3.19g, 6.7mmol, 1.0 equiv.) dropwise over a period of 10min at 50 ℃.

The resulting yellowish suspension was stirred at 50 ℃ overnight, then cooled to room temperature and the white solid (NaCl) was filtered off via a buchner funnel. Ethyl acetate (50mL) was added to the filtrate and the organic phase was washed with demineralized water (2X 50mL) and saturated NaCl solution (2 in50mL) and washed with Na₂SO₄And (5) drying. The solvent was removed under reduced pressure. No column chromatography purification on silica gel was performed, as the crude product showed a sufficiently high purity, and otherwise the yield would be much lower.

After drying under high vacuum, the title compound was isolated as a pale yellow oil (3.13g, 6.1mmol, 91%).

¹H NMR(500MHz,DMSO-d₆)δ3.74(q,J＝7.0Hz,6H,-SiOCH ₂CH₃),2.81(t,J＝7.2Hz,2H,-CH ₂SC(O)CH₃),2.49-2.42(m,8H,-SCH₂-),2.31(s,3H,-SC(O)CH₃),1.60-1.52(m,2H,-SiCH₂CH ₂CH₂-),1.53-1.45(m,8H,-CH₂-),1.33(td,J＝7.1,3.4Hz,8H,-CH₂-),1.14(t,J＝7.0Hz,9H,-SiOCH₂CH ₃),0.69-0.62(m,2H,-SiCH ₂CH₂CH₂-)。

¹³C NMR(126MHz,DMSO-d₆)δ195.10,57.64,34.01,31.01,30.98,30.88,30.48,29.11,29.00,28.93,28.23,27.74,27.67,27.61,22.89,18.14,9.20。

ESI-MS m/z(％)：467.21[M+H-EtOH]⁺(61),530.28[M+NH₄]⁺(100)。

The silanes prepared having the formula II) 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 silane of the formula II) is preferably adsorbed onto the silica beforehand and is subsequently added in this form to the rubber mixture.

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

to a suspension of silica (e.g. particulate silica) in DMF at room temperature is added a solution of silane of formula II) dissolved in DMF at a desired silica/silane ratio. For example, silica (VN3, winning company) and 14.4phf silanes of formula II) were used.

For example, the resulting suspension is stirred at 120 ℃ overnight, and the solvent is subsequently removed under reduced pressure. After drying at 40 ℃ under high vacuum for one day, the modified silica thus obtained is comminuted with the aid of a mortar (possibly according to the desired fineness). It is then dried for another day, for example at 40 ℃ under high vacuum.

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

The invention will be illustrated in further detail by means of comparative and working examples of rubber mixtures summarized in table 1. The comparative mixture is designated V and the inventive mixture is designated E. The amount of silane calculated as phf is based on the corresponding amount of silica.

The mixtures were produced in multiple stages in a twin-screw extrusion mixer under conventional conditions. Test specimens which were produced from all mixtures by vulcanization and which were used to determine the material properties typical for the rubber industry.

The tests described for the test specimens were carried out by the following test methods:

standard: ISO 868, DIN 53505; shore A hardness at room temperature and 70 ℃.

Standard: ISO 4662, DIN 53512; resilience at room temperature and 70 ℃.

Standard: DIN 53513; maximum loss factor tan delta max at 55 ℃ as maximum of strain sweep from dynamic-mechanical measurements

Standard: ASTM D6601; loss factor tan delta (10%) and dynamic storage modulus (G '(1%), G' (100%) for the second strain scan at 1Hz and 70 deg.C

Standard: ISO 37, ASTM D412, DIN 53504; the elongation at break at room temperature and the energy density at break at room temperature, which is the work required to break based on the volume of the sample, were determined by tensile testing.

a) NR TSR: natural rubber.

b) SSBR: solution polymerized styrene-butadiene copolymers with hydroxyl groups from the prior art,NS 612, available from Eichhornia Corporation (Zeon Corporation).

c) Silicon dioxide: VN3 from winning companies.

d) The silane is pre-silanized/reacted in the appropriate amount with the silica mentioned in a separate step. Silica and silane are fed together as a modifying filler to the mixing process.

e) Additional additives: zinc oxide/aging stabilizer/antiozonant/stearic acid

The inventive mixture E1 (comprising the inventive silane having the formula II) shows a reduced resilience at room temperature and an increased resilience at 70 ℃ by comparison with the reference mixture V1 (comprising the silane TESPD). An increase in this difference (resilience at 70 ℃ C. -resilience at room temperature) is advantageous in terms of the compromise between rolling resistance and grip characteristics, and the maximum loss factor of E1 is additionally lower than V1. These characteristics show the improvement in rolling resistance in tire applications by those skilled in the art.

The observed predictive indicator of increased stiffness of E1 compared to V1 is an increase in shore a hardness at room temperature and 70 ℃.

Furthermore, in the case of E1, an increased elongation at break and energy density at break compared to V1 were observed.

These different characteristics lead to improved service life and tear resistance while improving rolling resistance characteristics and clearly show the benefits of the silanes of the present invention over the prior art.

TABLE 1