JP5530765B2 - Rubber additive and rubber composition - Google Patents

Description

  The present invention relates to an additive for rubber and a rubber composition using the same.

With recent social demands for energy saving, attempts have been made to reduce heat generation (reduction of rolling resistance) of tire rubber for the purpose of saving fuel consumption of automobiles. In order to reduce the heat generation of rubber for tires, reduction of the amount of carbon black often used as a reinforcing filler for rubber, or the use of carbon black having a large particle size has been studied. However, in any case, it is known that the reinforcing property, the wear resistance, the grip property (driving stability) on the dry road surface and the wet road surface cannot be avoided.
On the other hand, hydrous silicic acid (wet silica) is known as a filler that achieves both low rolling resistance and handling stability on wet road surfaces. However, in this wet silica, particles tend to aggregate due to hydrogen bonding of silanol groups which are surface functional groups, and in order to improve dispersion of silica in rubber, it is necessary to lengthen the kneading time. Further, since the silica is not sufficiently dispersed in the rubber, the rubber composition has a high Mooney viscosity, and has disadvantages such as inferior processability such as extrusion. Furthermore, since the surface of the silica particles is acidic, the basic substance used as a vulcanization accelerator is adsorbed, the rubber composition is not sufficiently vulcanized, and the storage elastic modulus is not improved. Has the disadvantage that the steering stability is not sufficient.

As a method for improving the handling stability without impairing the fuel efficiency of the silica-containing rubber, a method of adding a resin (see, for example, Patent Documents 1 and 2), a compound having a polymerizable unsaturated bond and a specific functional group Has been proposed (for example, Patent Document 3). However, this rubber composition has a problem of surface roughness of the vulcanized rubber due to insufficient compatibility between these resins and rubber, and an effect of improving the storage elastic modulus. There was a problem that the stability was not sufficiently improved.
On the other hand, it is known that the use of sulfur-containing polyesters can give mechanical properties and good hysteresis properties of vulcanized rubber (for example, Patent Document 4), but there is no description about storage elastic modulus. Absent. Further, a rubber composition using a compound having a reactive group for rubber and an adsorbing group for an inorganic filler such as silica in the same molecule as an additive for rubber has been proposed (for example, Patent Document 5). However, although this rubber composition shows a certain effect in improving the storage elastic modulus, development of a rubber additive that achieves both good operational stability on a dry road surface and excellent rolling resistance is desired. ing.

JP 2000-80205 A JP 2000-290433 A JP 2002-179841 A JP-A-8-333488 JP 2003-176378 A

  An object of the present invention is to provide a rubber additive capable of imparting good steering stability on a dry road surface and excellent rolling resistance to a tire, a rubber composition containing the rubber additive, and a member obtained from the rubber composition. The tire used as is to provide.

  As a result of intensive studies to achieve the above object, the present inventors have found that the object can be achieved by a compound having a specific bonding group and a specific number average molecular weight. The present invention has been completed based on such findings. That is, the gist of the present invention is as follows.

1. A rubber additive comprising a compound having at least one bonding group A capable of chemically bonding to rubber and two or more bonding groups B capable of chemically bonding to silica and having a number average molecular weight of 900 to 15000 .
2. The bonding group A is a bonding group A1 that can be covalently bonded to rubber, the bonding group B includes a bonding group B1 that can be covalently bonded to silica, and a bonding group B2 that can be hydrogen bonded to silica. The rubber additive according to 1.
3. 3. The rubber additive according to 2 above, which has a linking group B2 between the linking group A1 and the linking group B1.
4). 4. The rubber additive according to 3 above, which has a bonding group B1 at the terminal.
5. 5. The rubber additive according to any one of 2 to 4 above, wherein the bonding group A1 is a sulfide group.
6). The rubber additive according to any one of 2 to 5 above, wherein the bonding group B1 is an alkoxysilyl group or a silanol group.
7). 7. The rubber additive according to any one of 2 to 6 above, wherein the bonding group B2 is an oxycarbonyl group and / or an ether group.
8). An additive for rubber containing a compound represented by the following general formula (1).

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ² represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a group represented by —R ⁷ R ⁸ R ^9. , R ⁷ represents a single bond or an alkanediyl group having 1 to 8 carbon atoms, R ⁸ represents a group represented by —S—CO— or —CS—O—, and R ⁹ represents a hydrogen atom or 1 carbon atom. R ³ represents an alkanediyl group having 1 to 8 carbon atoms, R ⁴ represents an alkanediyl group having 1 to 18 carbon atoms or an alkenediyl group having 2 to 18 carbon atoms, R ⁵ and R ⁶ represents an alkanediyl group having 1 to 8 carbon atoms or an alkenediyl group having 2 to 8 carbon atoms, and a plurality of R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ may be the same or different. K is an integer of 1 to 3, m is an integer of 0 to 2, and k + m = 3 is satisfied, n is 0 or 1, and w Is 0 or 1, x is an integer of 2-4 indicating the number of sulfur atoms, y is a number of 0.8-100 indicating the average polymerization number, and z is 1-31 indicating the average polymerization number. Number.)
9. The rubber additive according to any one of 1 to 8 above, containing 50% by mass or more of the compound.
10. A rubber composition comprising (A) natural rubber and / or a diene synthetic rubber, and (B) an inorganic filler containing silica and the rubber additive according to any one of 1 to 9 above.
11. 11. The rubber composition as described in 10 above, comprising the rubber additive in a proportion of 0.5 to 20 parts by mass with respect to 100 parts by mass of the component (B).
12 The rubber composition according to the above 10 or 11, comprising the component (B) at a ratio of 10 to 140 parts by mass with respect to 100 parts by mass of the component (A).
13. (B) The rubber composition according to any one of the above 10 to 12, wherein the component is silica.
14 14. The rubber composition according to any one of 10 to 13 used for a tire.
15. A tire using the rubber composition according to any one of 10 to 13 as a member.
16. 16. The tire according to 15 above, wherein the member is a tread and / or a tread base.

  According to the present invention, a rubber additive capable of imparting good steering stability to a tire on a dry road surface and excellent rolling resistance, a rubber composition containing the rubber additive, and the rubber composition as a member The tire used as can be obtained.

[Rubber additives]
The rubber additive of the present invention has at least one bonding group A that can be chemically bonded to rubber and two or more bonding groups B that can be chemically bonded to silica, and has a number average molecular weight of 900 to 15000. It is an additive for rubber | gum containing the compound which is.

<< Binding group A >>
The bonding group A used in the present invention is a group capable of chemically bonding to rubber contained in one or more rubber additives, and preferably a group capable of covalent bonding to rubber. The bonding group A is not particularly limited as long as it can be chemically bonded to the rubber, but preferably includes a sulfide group represented by -Sx- (x is an integer of 2 to 4 indicating the number of sulfur atoms). In particular, x is preferably 2 to 3, and a disulfide group in which x is 2 is more preferable. When the bonding group A is a sulfide group, the reactivity of the rubber additive with the rubber is improved and the heat generation becomes low, so that excellent rolling resistance can be obtained.

<< Binding group B >>
The bonding group B used in the present invention is a group capable of chemically bonding to silica contained in two or more of the rubber additive. The linking group B is preferably a linking group B1 that can be covalently bonded to silica and a linking group B2 that can be hydrogen bonded to silica, and may contain two or more of these. Although two types of group B2 may be included, in order to obtain good steering stability on a dry road surface and excellent rolling resistance, it is preferable to include two types of bonding group B1 and bonding group B2.

The bonding group B1 is not particularly limited as long as it can be covalently bonded to silica, but an alkoxysilane group and a silanol group are preferable, and these can be used alone or in combination.
The bonding group B2 is not particularly limited as long as it can hydrogen bond to silica, but an oxycarbonyl group and an ether group are preferable, and these can be used alone or in combination.

  In the rubber additive of the present invention, the bonding group B1 is preferably present at the terminal. The linking group B2 is preferably present between the linking group A and the linking group B1. In this way, the rubber additive ensures excellent chemical bond with silica and can also have excellent chemical bond with rubber, so it has good steering stability on dry road surface and excellent This is because rolling resistance can be obtained.

<Number average molecular weight>
The compound used for the rubber additive of the present invention needs to have a number average molecular weight of 900 to 15000, preferably 900 to 10,000, and more preferably 900 to 5000. If the number average molecular weight of the compound is within the above range, the storage elastic modulus is improved, so that good steering stability can be obtained. Here, the number average molecular weight of the polyester compound is a value measured using gel permeation chromatography (GPC) (polystyrene conversion). In addition, G2000HXL and G1000HXL (both manufactured by Tosoh Corporation) were connected in series to the column. The developing solvent was tetrahydrofuran (THF), and the sample / solvent was 0.04 g / 10 ml. However, if the compound has a bonding group B1, it may react with silica used as a carrier for a GPC column, and an accurate measurement value may not be obtained. In such a case, the precursor having no linking group B1 is measured, and the value obtained by adding the molecular weight of the modified portion having the linking group B1 introduced thereafter to the obtained measured value is used as the compound having the linking group B1. The number average molecular weight of

"Compound"
The rubber additive of the present invention contains a compound represented by the following general formula (1).

In formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and the alkyl group having 1 to 3 carbon atoms may be linear or branched, for example, a methyl group , Ethyl group, n-propyl group, and isopropyl group. R ¹ and R ² are preferably a hydrogen atom, a methyl group and an ethyl group, more preferably a hydrogen atom and an ethyl group. A plurality of R ¹ may be the same or different.

R ² represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or a group represented by —R ⁷ R ⁸ R ⁹ , and the plurality of R ² may be the same or different. R ⁷ represents an alkanediyl group having 1 to 8 carbon atoms, R ⁸ represents —S—CO— or —CS—O—, and R ⁹ represents an alkyl group having 1 to 18 carbon atoms.
Here, the alkyl group having 1 to 3 carbon atoms of R ² is the same as R ¹ .
R ⁷ is a single bond or an alkanediyl group having 1 to 8 carbon atoms, preferably an alkanediyl group having 1 to 4 carbon atoms, and the alkanediyl group may be linear or branched. Good. Examples of such alkanediyl groups include methylene group, ethylene group, 1,2-propanediyl group, 1,3-propanediyl group, and various butanediyl groups. Among these, a methylene group, an ethylene group, a 1,2-propanediyl group, a 1,3-propanediyl group and a 1,4-butanediyl group are preferable, and an ethylene group and a 1,3-propanediyl group are particularly preferable.

R ⁸ represents a group represented by —S—CO— or —CS—O—, and preferably a group represented by —S—CO—.
R ⁹ is a hydrogen atom having 1 to 18 carbon atoms or an alkyl group, preferably an alkyl group having 1 to 8 carbon atoms, and the alkyl group may be linear or branched. Examples of such an alkyl group include a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, s-butyl group, various pentyl groups, various hexyl groups, and various types. A heptyl group and various octyl groups are mentioned. Of these, R ⁹ is preferably an n-heptyl group.

R ³ represents an alkanediyl group having 1 to 8 carbon atoms, preferably an alkanediyl group having 1 to 4 carbon atoms, and the alkanediyl group may be linear or branched. Examples of such alkanediyl groups include methylene group, ethylene group, 1,2-propanediyl group, 1,3-propanediyl group, and various butanediyl groups. Among these, a methylene group, an ethylene group, a 1,2-propanediyl group, a 1,3-propanediyl group, and a 1,4-butanediyl group are preferable, and a 1,2-propanediyl group is particularly preferable. A plurality of R ³ may be the same or different.

R ⁴ represents an alkanediyl group having 1 to 18 carbon atoms or an alkenediyl group having 2 to 18 carbon atoms, preferably an alkanediyl group having 1 to 6 carbon atoms or an alkenediyl group having 2 to 6 carbon atoms, linear, Any of a branched shape may be used. Examples of such alkanediyl groups include methylene group, ethylene group, 1,2-propanediyl group, 1,3-propanediyl group, various butanediyl groups, various pentanediyl groups, and various hexanediyl groups. Among these, a methylene group, an ethylene group, a 1,2-propanediyl group, a 1,3-propanediyl group, a 1,4-butanediyl group and the like are preferable, and a 1,4-butanediyl group is particularly preferable.
Examples of the alkenediyl group include a vinylene group, 1-methylvinylene group, propenediyl group, various butenediyl groups, various pentenediyl groups, and various hexenediyl groups. Among these, a vinylene group, a propenediyl group, a 1-butenylene group, a 2-butenylene group and the like are preferable, and a 1-butenylene group and a 2-butenylene group are particularly preferable.
A plurality of R ⁴ may be the same or different. For example, R ⁴ O may be ethylene oxide alone or a combination of ethylene oxide and propylene oxide.

R ⁵ and R ⁶ represent an alkanediyl group having 1 to 8 carbon atoms or an alkenediyl group having 2 to 8 carbon atoms, preferably an alkanediyl group having 1 to 4 carbon atoms or an alkenediyl group having 2 to 4 carbon atoms, The shape may be either branched or branched. As such an alkanediyl group, for example, a methylene group, an ethylene group, a 1,2-propanediyl group, a 1,3-propanediyl group, and various butanediyl groups are preferable, and an ethylene group is particularly preferable. A plurality of R ⁵ and R ⁶ may be the same or different.

k represents an integer of 1 to 3, m represents an integer of 0 to 2, and k + m = 3 is satisfied. N is 0 or 1, and w is 0 or 1.
x is an integer of 2 to 4 indicating the number of sulfur atoms, and 2 is preferable. Further, the plurality of sulfur atoms x may be the same or different. For example, in the compound, only disulfide may be present, or disulfide and trisulfide may be present.
y is the number of 0.8-100 which shows an average number of polymerization, Preferably it is a number of 1-20, More preferably, it is a number of 1-10. Z is a number of 1 to 31 indicating the average number of polymerizations, preferably 2 to 21 and more preferably 2 to 10.

<< Production Method of Compound >>
A preferred embodiment of the method for producing the compound used for the rubber additive of the present invention will be described with reference to the case where the compound is represented by the general formula (1). The compound used for the rubber additive of the present invention is represented by the following general formula (2) or (3):

(In the formula, R ⁴ and z are the same as described above.)

A diol monomer represented by the following general formula (4):

(In the formula, R ⁵ , R ⁶ and x are the same as described above.)

A polyester compound obtained by polycondensation with a dicarboxylic acid monomer containing a sulfide group represented by the formula (II) under a condition in which the molar amount of hydroxyl group of the diol monomer is larger than the molar amount of carboxy group of the dicarboxylic acid monomer is used as a precursor. By polycondensation in such a blend, both ends of the polyester compound precursor become hydroxyl groups. Usually, hydroxyl group molar amount / carboxy group molar amount = about 100/99 to 100/50, preferably 100/98 to 100/60.

  Next, the obtained polyester compound precursor and the following general formula (5):

(In the formula, R ¹ , R ² , R ³ , k and m are the same as described above.)

Or a urethanization reaction with an isocyanate compound represented by the following general formula (6):

(Wherein R ¹ , R ² , k and m are the same as above).

The compound used for the additive for rubber | gum of this invention is obtained by performing the alcohol exchange reaction with the alkoxysilane compound shown by these.

(Diol monomer)
Examples of the diol monomer represented by the general formula (2) used in the above production method include alkanediols such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, and decanediol. An alkene diol such as butene diol is preferred.

  Moreover, as a diol monomer shown by General formula (3), on average, polyoxyethylene, polyoxypropylene, polyoxytrimethylene and / or polyoxytetramethylene is 1 to ethylene glycol, propylene glycol and butanediol. Preferable examples include those added with 30 mol, preferably 2 to 20 mol, polyoxyethylene glycol, polyoxypropylene glycol and the like.

(Dicarboxylic acid monomer containing sulfide group)
In the dicarboxylic acid monomer containing the sulfide group represented by the general formula (4) used in the above production method, the sulfide group is x from the viewpoint of suppressing the gelation of the polymer in the kneading operation in the preparation of the rubber composition. 2 to 4, preferably 2 disulfide groups.
Examples of the dicarboxylic acid monomer containing such a sulfide group include 2,2′-dithiodiacetic acid, 3,3′-dithiodipropionic acid, 4,4′-dithiodibutanoic acid, 5,5′-dithiodipentanoic acid, Preferred examples include 6,6′-dithiodihexanoic acid, 7,7′-dithiodiheptanoic acid, 8,8′-dithiodioctanoic acid, 9,9′-dithiodinonanoic acid, and 10,10′-dithiodidecanoic acid. Of these, 3,3′-dithiodipropionic acid is more preferable.

(Isocyanate compound)
Examples of the isocyanate compound represented by the general formula (5) used in the above production method include trimethoxysilylbutyl isocyanate, trimethoxysilylpropyl isocyanate, trimethoxysilylethyl isocyanate, triethoxysilylbutyl isocyanate, triethoxysilylpropyl isocyanate, Preferred is ethoxysilylethyl isocyanate. Of these, triethoxysilylbutyl isocyanate, triethoxysilylpropyl isocyanate, and triethoxysilylethyl isocyanate are more preferable from the viewpoint of safety during rubber kneading.

(Alkoxysilane)
Examples of the alkoxysilane represented by the general formula (6) used in the above production method include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, methyltrimethoxysilane, methyltripropoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, Preferable examples include 3-octanoylthio-1-propyltrimethoxysilane and 3-octanoylthio-1-propyltriethoxysilane. Of these, tetraethoxysilane, methyltriethoxysilane, and 3-octanoylthio-1-propyltriethoxysilane are preferable from the viewpoint of safety during rubber kneading.

(Synthesis of polyester compound precursor)
In the synthesis of the polyester compound precursor, the polycondensation method of the diol monomer and the dicarboxylic acid monomer is not particularly limited, and a method of directly esterifying the diol monomer and the dicarboxylic acid monomer, or a diol monomer and an alkyl ester of the dicarboxylic acid And the like. The polycondensation is preferably performed at a temperature of 60 to 220 ° C. and from the viewpoint of preventing the decomposition of sulfide bonds, preferably at 60 to 200 ° C., more preferably at 60 to 160 ° C., by removing water. If necessary, a solvent such as cyclohexane, benzene, toluene, and / or xylene can be used. In the polycondensation, for the purpose of promoting polycondensation, it is preferable to use a catalyst generally used in the above method, such as p-toluenesulfonic acid or methanesulfonic acid.

(Urethaneization reaction and alcohol exchange reaction)
There is no restriction | limiting in particular in the reaction conditions of a urethanation reaction using a polyester compound precursor and an isocyanate compound. The urethanization reaction proceeds rapidly at a low temperature even in the absence of a catalyst, but a catalyst such as triethylamine, which is usually used for the urethanization reaction, can be used as necessary.
Moreover, there is no restriction | limiting in particular in the conditions of alcohol exchange reaction using a polyester compound precursor and an alkoxysilane compound. If necessary, a catalyst such as tetraisopropoxytitanium or p-toluenesulfonic acid, which is usually used for alcohol exchange reaction, can be used.

《Rubber additive》
The rubber additive of the present invention can contain a known rubber additive in addition to the above-described compounds. In addition, the compound is diluted with an oil, an ester compound, or an organic compound that does not inhibit the effect of the compound, if desired.
The content of the compound in the rubber additive of the present invention is preferably 50% by mass or more, more preferably 50 to 99% by mass, and still more preferably from the viewpoint of suitably obtaining the effects of the present invention. It is 70-99 mass%, Most preferably, it is 80-99 mass%. If the content of the compound is within the above range, the rubber additive can give the tire good steering stability on a dry road surface and excellent rolling resistance.

[Rubber composition]
The rubber composition of the present invention comprises (A) natural rubber and / or diene-based synthetic rubber, and (B) an inorganic filler containing silica, and further the above-mentioned rubber additive.
The rubber additive is preferably contained in a proportion of 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass, and still more preferably 2 to 10 parts by mass with respect to 100 parts by mass of the component (B). If the content of the rubber additive is within the above range, the effect of blending the additive is sufficiently exerted, and the effect corresponding to the blending amount is improved, which is economically advantageous.

<< (A) Natural rubber and / or diene synthetic rubber >>
Examples of the diene synthetic rubber include polyisoprene synthetic rubber (IR), polybutadiene rubber (BR), styrene-butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), chloroprene rubber (CR), and butyl rubber (IIR). It is done. The natural rubber and diene synthetic rubber of component (A) may be used alone or in combination of two or more.

<< (B) Inorganic filler containing silica >>
The rubber composition of the present invention contains (B) an inorganic filler containing silica.
Silica means not only silicon dioxide in a narrow sense but also means a silicic filler. Specifically, in addition to anhydrous silicic acid, silica such as hydrous silicic acid, calcium silicate, and aluminum silicate. It contains acid salts.

Carbon black etc. are mentioned preferably as an inorganic filler containing (B) silica other than silica. Carbon black is a known carbon black in which ranges such as I ₂ adsorption amount, CTAB specific surface area, N ₂ adsorption amount, DBP adsorption amount are appropriately selected as long as it improves mechanical performance and improves processability. Can be used. As the type of carbon black, for example, known ones such as SAF, ISAF-LS, HAF, HAF-HS can be appropriately selected and used. In view of wear resistance, ISAF or SAF having a fine particle size is preferable.

  (B) The inorganic filler containing silica may be silica alone or a combination of silica and inorganic fillers other than silica, and in particular, silica alone or a combination of the above-described carbon black and silica. Are preferably used.

  The content of the inorganic filler containing (B) silica in the rubber composition of the present invention is preferably in the range of 10 to 140 parts by mass with respect to 100 parts by mass of the component (A). By setting the content of the component (B) to 10 to 140 parts by mass, the object of the present invention can be achieved without adversely affecting the reinforcing properties and other rubber properties. In this respect, the content of the component (B) is more preferably in the range of 10 to 90 parts by mass with respect to 100 parts by mass of the component (A). When (B) carbon black and silica are used in combination as an inorganic filler containing silica, the mixing ratio [carbon black] / [silica] of carbon black and silica is 0.04 to 6. 0 is preferable, 0.1 to 3.0 is more preferable, and 0.1 to 1.0 is more preferable.

  In the rubber composition of the present invention, various compounding agents usually used in the rubber industry, for example, silane coupling agents, vulcanizing agents, vulcanization accelerators, aging, as long as the object of the present invention is not impaired. An inhibitor, a scorch inhibitor, a softener, zinc white, stearic acid, and the like can be contained.

The method for adding the rubber additive, (B) silica-containing inorganic filler, and various compounding agents to the rubber composition in the present invention is not particularly limited, and (A) natural rubber and / or diene-based synthetic rubber Addition and mixing can be performed using an ordinary kneader, for example, a Banbury mixer, a roll, or an intensive mixer.
The rubber composition of the present invention thus obtained can be used as a tire member, and the member is particularly preferably used for a tread or a tread base. A pneumatic tire is manufactured by a normal method using the rubber composition of the present invention. That is, if necessary, the rubber composition of the present invention containing various chemicals as described above is extruded to a tread member, for example, at an unvulcanized stage and pasted on a tire molding machine by a usual method. The green tire is formed by attaching. The green tire is heated and pressed in a vulcanizer to obtain a tire.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
(Evaluation method)
(1) Dynamic viscoelasticity About the rubber composition of the compounding prescription shown in Table 2 and Table 3, using a spectrometer (dynamic viscoelasticity measuring tester) manufactured by Ueshima Seisakusho Co., Ltd., frequency 52 Hz, initial strain The storage elastic modulus (E ′) at 60 ° C. and the value of tan δ were measured at a rate of 2% and a dynamic strain rate of 1%, and are shown in Tables 3 and 4 as indices with Comparative Examples 1 and 3 as 100. It was. A larger index of storage elastic modulus (E ′) indicates better rubber physical properties, and a smaller index of tan δ indicates lower exothermic properties.
(2) Measurement of 300% modulus (M300) With respect to the rubber compositions having the compounding formulations shown in Tables 2 and 3, the 300% modulus (M300) was measured according to JIS K 7113 (plastic tensile test method). The measurement results are shown in Tables 2 and 3.
(3) Rolling resistance A pneumatic tire having a tire size of 225 / 45R17 was manufactured using a single-layer tread by using the rubber compositions having the compounding formulations shown in Tables 2 and 3 as tread members.
The tire resistance of the prototype was 250 kPa, and the rolling resistance when rotating at a speed of 80 km / h using a rotating drum with a diameter of 1700 mm under the action of a load of 3.92 kN was measured by the coasting method. Tables 2 and 3 show indexes with 1 and 3 as 100. The larger the rolling resistance index, the smaller and better the rolling resistance.
(4) Steering stability on dry road surface A pneumatic tire having a tire size of 225 / 45R17 was made as a tread having a single layer structure using the rubber compositions having the compounding formulations shown in Tables 2 and 3 as tread members.
The air pressure of the prototype tire was set to 250 kPa, and the tire was mounted on four wheels of a passenger car. A test driver ran on the test course in this test vehicle. The results of the test driver's feeling of driving stability and ride comfort on the dry road surface in comparison with the control tire (Comparative Examples 1 and 3) according to the following evaluation criteria These are shown in Tables 3 and 4.
+4: When a driver feels good enough to understand a general driver +3: When a driver feels good enough to understand a skilled driver +2: When a driver feels good enough to clearly understand a test driver +1: A test driver is subtly When it feels good enough to understand -1: When it feels bad enough to understand the test driver -2: When it feels bad enough to clearly understand the test driver -3: To the extent that a skilled driver can understand among general drivers -4: If you feel bad enough to understand a general driver

Production Example 1 (Production of Compound 1)
Polytetramethylene glycol (number average molecular weight: 250, hereinafter referred to as PTMG250) 1300 g (5.20 mol) and dithiodipropionic acid (hereinafter referred to as DTDPA) 984 g (4.68 mol) were added to a 2 L four-necked flask. ), 0.1% by mass of p-toluenesulfonic acid of the obtained mixture was added, and polycondensation was performed by stirring at 140 ° C. for 8 hours under reduced pressure (200 mmHg) / nitrogen stream. When water generated by polycondensation was removed, 2080 g of a pale yellow viscous oil (polyester compound precursor 1) was obtained. The number average molecular weight of the polyester compound precursor 1 was 3900.
Next, 550 g of the obtained polyester compound precursor 1 and 67 g of triethoxysilylpropyl isocyanate are charged into a 1 L four-necked flask and stirred at 60 ° C. for 8 hours in a dry nitrogen atmosphere to perform a urethanization reaction. Compound 1 was obtained.

Production Examples 2 to 4, 6 and 7 (Production of Compounds 2 to 4, 6 and 7)
Each component shown in Table 1 was mixed at the blending ratio shown in Table 1, and polycondensation and urethanization reaction were carried out in the same manner as in Production Example 1 to obtain compounds 2 to 4, 6 and 7.

Production Example 5 (Production of Compound 5)
Polycondensation was performed in the same manner as in Production Example 1 to obtain a polyester compound precursor 1, 1000 g of the obtained polyester compound precursor 1 and 102 g of tetraethoxysilane were charged, and the mixture was stirred at 100 ° C. for 6 hours in a dry nitrogen atmosphere. An alcohol exchange reaction was performed, and the produced ethanol was removed to obtain Compound 5.

Production Example 8 (Production of Compound 8)
Each component shown in Table 1 was mixed at the blending ratio shown in Table 1, and polycondensation and alcohol exchange reaction were performed in the same manner as in Production Example 5 to obtain Compound 8.

Production Example 9 (Production of Compound 9)
Each component shown in Table 1 was mixed at the mixing ratio shown in Table 1, and polycondensation and alcohol exchange reaction were performed in the same manner as in Production Example 5 to obtain Compound 9.

Production Example 10 (Production of Compound 10)
Each component shown in Table 1 was mixed at the mixing ratio shown in Table 1, and polycondensation and alcohol exchange reaction were performed in the same manner as in Production Example 5 to obtain Compound 10.

＊１，ポリテトラメチレングリコール（数平均分子量：２５０）
＊２，ポリテトラメチレングリコール（数平均分子量：１０００）
＊３，ポリテトラメチレングリコール（数平均分子量：２０００）
＊４，ポリエチレングリコール（数平均分子量：２００）
＊５，ジチオジプロピオン酸
＊６，Ａ：ウレタン化反応、Ｂ：アルコール交換反応

* 1, Polytetramethylene glycol (number average molecular weight: 250)
* 2, Polytetramethylene glycol (number average molecular weight: 1000)
* 3, polytetramethylene glycol (number average molecular weight: 2000)
* 4 Polyethylene glycol (number average molecular weight: 200)
* 5, Dithiodipropionic acid * 6, A: Urethane reaction, B: Alcohol exchange reaction

Examples 1-12, Comparative Examples 1-6
Each component shown in Table 2 to Table 4 was mixed at each compounding ratio to prepare a rubber composition. A Banbury mixer and a roll mixer were used for the preparation. Vulcanization was carried out at a temperature of 165 ° C., and the vulcanization time was defined as Curast T90 value (min) × 1.5 times. The obtained rubber composition was evaluated in a dynamic viscoelasticity measurement test using physical properties of vulcanized rubber as an index. The results are shown in Tables 2-4. In the dynamic viscoelasticity measurement test, the index was displayed based on Comparative Examples 1, 3, and 5.
Moreover, about the tire using the obtained rubber composition, rolling resistance and steering stability were evaluated as a tire performance parameter | index. The results are shown in Tables 2-4.

＊１，「ＳＢＲ＃１７１２（商品名）」：ジェイエスアール株式会社製、ＳＢＲ＃１７１２の１３７．５質量部中、３７．５質量部が油展である。
＊２，「シースト３００（商品名）」：東海カーボン株式会社製
＊３，「ニップシールＶＮ３（商品名）」：東ソーシリカ株式会社製
＊４，ビス（３−トリエトキシシリルプロピル）テトラスルフィド
＊５，製造例１で得られた化合物
＊６，製造例２で得られた化合物
＊７，製造例３で得られた化合物
＊８，製造例４で得られた化合物
＊９，製造例５で得られた化合物
＊１０，製造例６で得られた化合物
＊１１，製造例７で得られた化合物
＊１２，製造例８で得られた化合物
＊１３，製造例９で得られた化合物
＊１４，製造例１０で得られた化合物
＊１５，ＰＴＭＧ２５０を１０００ｇとＤＴＤＰＡを９２５ｇとの重縮合により得られた化合物
＊１６，Ｎ−（１，３−ジメチルブチル）−Ｎ’−フェニル−ｐ−フェニレンジアミン
＊１７，Ｎ−オキシジエチレン−２−ベンゾチアゾールスルフェンアミド
＊１８，ジフェニルグアニジン

* 1, “SBR # 1712 (trade name)”: 37.5 parts by mass of the 137.5 parts by mass of SBR # 1712 manufactured by JSR Corporation is the oil exhibition.
* 2, “Seast 300 (trade name)”: manufactured by Tokai Carbon Co., Ltd. * 3, “Nip seal VN3 (trade name)”: manufactured by Tosoh Silica Co., Ltd. * 4, bis (3-triethoxysilylpropyl) tetrasulfide * 5 , Compound * 6 obtained in Production Example 1, compound * 7 obtained in Production Example 2, compound * 8 obtained in Production Example 3, compound * 9 obtained in Production Example 4, obtained in Production Example 5 Compound * 10 obtained in Production Example 6, compound * 11 obtained in Production Example 7, compound * 12 obtained in Production Example 7, compound * 13 obtained in Production Example 8, compound * 14 obtained in Production Example 9, Compound * 15 obtained in Production Example 10, compound obtained by polycondensation of 1000 g of PTMG250 and 925 g of DTDPA * 16, N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine * 17, N- Oxydiethylene-2-benzothiazolesulfenamide * 18, diphenylguanidine

＊１９，「Ｚｅｏｓｉｌ Ｐｒｅｍｉｕｍ ２００ＭＰ（商品名）」：Ｒｈｏｄｉａ社製

* 19, “Zeosil Premium 200MP (trade name)” manufactured by Rhodia

＊２０，「ＳＢＲ＃１５００（商品名）」：ジェイエスアール株式会社製
＊２１，「シーストＫＨ（商品名）」：東海カーボン株式会社製
＊２２，「ニップシールＫＱ（商品名）」：東ソーシリカ株式会社製
＊２３，「ＮＸＴシラン（商標）」：モメンティブパフォーマンスマテリアルズ製
＊２４，「ノクラック６Ｃ（商標）」：大内新興化学工業株式会社製
＊２５，「サンセラーＤＭ（商標）」：三新化学工業株式会社製
＊２６，「サンセラーＮＳ（商標）」：三新化学工業株式会社製

* 20, "SBR # 1500 (trade name)": JSR Corporation * 21, "Seast KH (trade name)": Tokai Carbon Co., Ltd. * 22, "Nip seal KQ (trade name)": Tosoh Silica Corporation * 23 made by company, “NXT silane (trademark)”: manufactured by Momentive Performance Materials * 24, “NOCRACK 6C (trademark)”: made by Ouchi Shinsei Chemical Co., Ltd. * 25, “Sunceller DM (trademark)”: Sanshin Made by Chemical Industry Co., Ltd. * 26, “Sunseller NS (trademark)”: Made by Sanshin Chemical Industry Co., Ltd.

  The rubber additive of the present invention can impart good steering stability on a dry road surface and excellent rolling resistance to a tire. The rubber composition using the rubber additive is suitable for use as a tire tread or a tread base member.

Claims (12)

The linking group A capable of chemically binding to rubber having one or more and two or more linking groups B that can perform chemical bond the silica, saw including a number average molecular weight of 900 to 15,000 compounds, the binding A rubber additive comprising a bonding group A1 in which the group A is a sulfide group, a bonding group B1 in which the bonding group B is an alkoxysilyl group or a silanol group, and a bonding group B2 which is an oxycarbonyl group and / or an ether group . The rubber additive according to claim 1 , which has a linking group B2 between the linking group A1 and the linking group B1. The rubber additive according to claim 2 , which has a linking group B1 at its terminal. An additive for rubber containing a compound represented by the following general formula (1).

(In the formula, R ¹ represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R ² represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a group represented by —R ⁷ R ⁸ R ^9. , R ⁷ represents a single bond or an alkanediyl group having 1 to 8 carbon atoms, R ⁸ represents a group represented by —S—CO— or —CS—O—, and R ⁹ has 1 to 18 carbon atoms. Represents an alkyl group, R ³ represents an alkanediyl group having 1 to 8 carbon atoms, R ⁴ represents an alkanediyl group having 1 to 18 carbon atoms or an alkenediyl group having 2 to 18 carbon atoms, and R ⁵ and R ⁶ represent An alkanediyl group having 1 to 8 carbon atoms or an alkenediyl group having 2 to 8 carbon atoms is shown, and a plurality of R ¹ , R ² , R ³ , R ⁴ , R ⁵ and R ⁶ may be the same or different. k represents an integer of 1 to 3, m represents an integer of 0 to 2, and satisfies k + m = 3, n is 0 or 1, and w is 0 or 1. Yes, x is an integer of 2-4 indicating the number of sulfur atoms, y is a number of 0.8-100 indicating the average number of polymerizations, and z is a number of 1-31 indicating the average number of polymerizations.) The rubber additive according to any one of claims 1 to 4 , comprising 50% by mass or more of the compound. A rubber composition comprising (A) natural rubber and / or a diene synthetic rubber, and (B) an inorganic filler containing silica and the rubber additive according to any one of claims 1 to 5 . The rubber composition according to claim 6 , comprising a rubber additive in a proportion of 0.5 to 20 parts by mass with respect to 100 parts by mass of the component (B). The rubber composition according to claim 6 or 7 , comprising the component (B) at a ratio of 10 to 140 parts by mass with respect to 100 parts by mass of the component (A). The rubber composition according to any one of claims 6 to 8 , wherein the component (B) is silica. The rubber composition according to any one of claims 6 to 9 , which is used for a tire. A tire using the rubber composition according to any one of claims 6 to 9 as a member. The tire according to claim 11 , wherein the member is a tread and / or a tread base.