JPH0713158B2 - tire - Google Patents

Description

TECHNICAL FIELD The present invention relates to rubber tires such as pneumatic tires and solid tires, and more particularly to a tire whose performance is economically improved by applying a rubber composition containing a silane compound-modified rubbery polymer and silica to the rubber tire.

BACKGROUND ART Conventionally, white fillers such as silica and magnesium carbonate have been used
Compared with carbon black for reinforcing rubber, the vulcanizates produced from it have poor tensile strength, modulus and impact resilience, and therefore it is rarely compounded into rubber compositions for tires.

In contrast, Japanese Patent Publication No. 40-20262 discloses that a tire having a tread in which silica is compounded with a rubber composition containing butadiene rubber, oil, and carbon has improved skid resistance, but is expected to have poor wear resistance due to its low modulus.

In addition, Japanese Patent Publication No. 38-26765 discloses that silica sol is mixed with rubber latex and then spray-dried to obtain the following:
A method has been proposed to obtain rubber with a higher modulus than that obtained by conventional kneading methods.

However, even this method does not currently offer the same reinforcing effect as carbon black.

Furthermore, Japanese Patent Application Laid-Open No. 50-88150 proposes a tread rubber for winter tires that has excellent slip resistance due to the use of a silane compound containing silica and sulfur atoms, but a large amount of the silane compound is required to obtain desirable tread properties.

Furthermore, Japanese Patent Publication No. 49-36957 proposes a method for improving processability by reacting a lithium-terminated polymer obtained using an organolithium compound as a catalyst with silicon tetrahalide, trichloromethylsilane, etc. to produce a branched polymer centered on the silane compound. However, since the resulting polymer does not contain any functional groups reactive with silica, the tensile strength of the vulcanizate using silica as a filler is insufficient. Furthermore, rubber containing silica in the unvulcanized state has increased viscosity and green strength, which can be rolled and extruded, but it has the disadvantage of large permanent set and dynamic heat buildup.

Furthermore, Japanese Patent Laid-Open Publication No. 104906/1981 discloses the addition of a silane compound having at least two hydrolyzable functional groups per molecule and represented by the following general formula: SiXnYmR4 _- n _- m (wherein X is a halogen atom, Y is a hydrolyzable organic group other than halogen, R is an alkyl group, aryl group, vinyl group or halogenated alkyl group, n is 0 or 1, m is an integer from 1 to 4, and the sum of n and m is at least 2). Here, an alkoxy group is preferred as the hydrolyzable organic group other than halogen, and the most suitable silane compounds listed are tetraethoxysilane, triethoxymonochlorosilane, diethoxymonochloromonomethylsilane, triethoxymonomethylsilane, trimethoxymonomethylsilane, diethoxydimethylsilane, dimethoxydimethylsilane, dimethyldiacetoxysilane, methyltriacetoxysilane, chloromethyltriethoxysilane and 3-chloropropyltriethoxysilane.

However, the hydrolyzable alkoxy group is hydrolyzed during steam coagulation after the polymerization reaction is completed.
It is impossible to improve tire performance by using the resulting silane compound-modified rubber polymer in a rubber composition containing silica as a reinforcing agent.

The present invention has been made in view of the above-mentioned conventional technical problems, and aims to economically achieve simultaneous improvements in tire performance such as abrasion resistance, cut resistance and heat buildup, as well as improvements in processability, which have been considered difficult with conventional technology, by using a rubber composition in a tire that has sufficiently high tensile strength and abrasion resistance, even in a vulcanizate that uses a white filler such as silica, without using a large amount of a conventional reinforcing aid such as a silane coupling agent.

DISCLOSURE OF THE INVENTION That is, the present invention provides a method for polymerizing a living polymer obtained by polymerizing a monomer using an organic alkali metal catalyst, by attaching to the active terminal of the polymer a compound represented by the following general formula (I): XnSi(OR) _mR'4 -m _- n (I) (wherein X represents a halogen atom such as a chlorine atom, a bromine atom, or an iodine atom; OR represents a non-hydrolyzable alkoxy group, aryloxy group, or cycloalkoxy group having 4 to 20 carbon atoms; R' represents an alkyl group, aryl group, vinyl group, or halogenated alkyl group having 1 to 20 carbon atoms; m represents a substituted or unsubstituted alkyl group having 1 to 4 carbon atoms;
n is an integer from 0 to 2, and the sum of m and n is from 2 to 4
A silane compound-modified rubbery polymer (hereinafter simply referred to as "silane compound-modified rubbery polymer") obtained by reacting a silane compound represented by the formula (I) with a rubber component is used.
The present invention provides a tire characterized in that a rubber composition containing 10% by weight or more of a hydroxy group carboxylate and 5 to 200 parts by weight of silica per 100 parts by weight of the rubber component is applied to at least one location of a tire rubber component.

Examples of the inert organic solvent used in the production of the silane compound-modified rubber polymer of the present invention include pentane, hexane, cyclohexane, heptane, benzene,
Xylene, toluene, tetrahydrofuran, diethyl ether, etc. are used.

In this case, a Lewis base can be used as a randomizer in the case of copolymerization, and also as a regulator of the microstructure of the conjugated diene when a conjugated diene is used as a monomer, if necessary. Examples of such a Lewis base include ethers such as dimethoxybenzene, tetrahydrofuran, dimethoxyethane, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, triethylamine, pyridine, N-methylmorpholine, N,N,N',N-tetramethylethylenediamine, and 1,2-dipiperidinoethane, and tertiary amines.

In addition, examples of the organic alkali metal catalyst used in the production of the silane compound-modified rubbery polymer of the present invention include alkyllithiums such as n-butyllithium, sec-butyllithium, t-butyllithium, 1,4-dilithiumbutane, and the reaction product of butyllithium with divinylbenzene, alkylenedilithium, phenyllithium, stilbene dilithium, diisopropenylbenzene dilithium, sodium naphthalene, and lithium naphthalene.

The monomers used in the silane compound-modified rubbery polymer of the present invention include all monomers that can be subjected to living polymerization using an organic alkali metal catalyst, such as conjugated dienes,
Examples of the vinyl aromatic compound include vinylpyridine, acrylonitrile, methacrylonitrile, methyl methacrylate, and acrylic esters.

Of these, conjugated dienes and/or vinyl aromatic compounds are preferred.

Here, the conjugated diene includes 1,3-butadiene, 2,3-
Dimethylbutadiene, Isoprene, Chloroprene, 1,3
However, 1,3-butadiene or isoprene is preferred because of its ease of copolymerization with other monomers.
The repeating units of the conjugated diene are mainly as follows:

(wherein R' represents a hydrogen atom, a methyl group, or a chlorine atom). Examples of aromatic vinyl compounds include styrene,
Examples of the aromatic vinyl compounds include α-methylstyrene, p-methylstyrene, o-methylstyrene, p-butylstyrene, and vinylnaphthalene, and preferably styrene. These aromatic vinyl compounds can be used alone or in combination of two or more.

The repeating units of aromatic vinyl compounds are mainly as follows:

(wherein ^R2 is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms,
or a halogen atom.) When a conjugated diene and an aromatic vinyl compound are used in combination, the molar ratio of conjugated diene/aromatic vinyl compound is 100/0 to 40/60, preferably 95/5 to 55/45.

In the method for polymerizing the living polymer used in the present invention, the inert organic solvent used in the present invention, the monomers and the organoalkali metal catalyst, and optionally a Lewis base, are charged all at once or, if necessary, are added intermittently or continuously into a reactor whose polymerization system has been purged with nitrogen, and polymerization is carried out.

The polymerization temperature is usually −120 to +150° C., preferably −80 to
The polymerization temperature is +120°C and the polymerization time is usually 5 minutes to 24 hours, preferably 10 minutes to 10 hours.

The polymerization temperature may be constant within the above temperature range, or the polymerization may be carried out at an elevated temperature or under adiabatic conditions.
The polymerization reaction may be batch or continuous.

The concentration of the monomer in the solvent is usually 5 to 50% by weight, preferably 10 to 35% by weight.

Furthermore, in order to produce a living polymer, care must be taken to minimize the inclusion of compounds that have a deactivating effect, such as halogen compounds, oxygen, water, or carbon dioxide gas, in the polymerization system, in order to prevent the deactivation of the organic alkali metal catalyst and the living polymer.

The silane compound-modified rubbery polymer used in the present invention is
A specific silane compound is reacted with the active terminal of the living polymer thus obtained in the polymerization system to produce a modified rubbery polymer having a Si-O-R bond (where R is as defined above) that is substantially non-hydrolyzable.

Here, "substantially no hydrolysis" means that 60 g of a rubber sheet molded at 120°C with a roll gap of 0.5 mm is placed in a stainless steel container with 3 parts of hot water, and steam is blown in to bring the hot water to a boil, and the resulting polymer is left for 30 minutes, and the increase in Mooney viscosity (ML ₁₊₄ , 100°C) of the polymer after drying is 10 points or less, preferably 5 points or less, compared to the untreated polymer.
This refers to cases where the number of points is less than or equal to the number of points.

The silane compound to be reacted with the living polymer of the present invention is a silane compound having a non-hydrolyzable alkoxy group in one molecule, and is represented by the following general formula (I).

XnSi(OR) _mR'4 -m _- n (I) (wherein X represents a halogen atom such as a chlorine atom, a bromine atom, or an iodine atom; OR represents a non-hydrolyzable alkoxy group, aryloxy group, or cycloalkoxy group having 4 to 20 carbon atoms; R' represents an alkyl group, aryl group, vinyl group, or halogenated alkyl group having 1 to 20 carbon atoms; and m represents a group of 1 to 4
n is an integer from 0 to 2, and the sum of m and n is from 2 to 4
That is, the silane compound of the present invention is an alkoxysilane compound having a non-hydrolyzable alkoxy group, and among these, R is preferably a hydrocarbon group having three carbon atoms bonded to the carbon at the α-position, a hydrocarbon group having a hydrocarbon group with one or more carbon atoms bonded to the carbon at the β-position, or an aromatic hydrocarbon group represented by a phenyl group or a toluyl group.

Among R', examples of alkyl groups include methyl, ethyl, n-propyl, and t-butyl groups; examples of aryl groups include phenyl, toluyl, and naphthyl groups; and examples of halogenated alkyl groups include chloromethyl, bromomethyl, iodomethyl, and chloroethyl groups.

In the general formula (I), when n is 0 and m is 2, an example is a dialkyldialkoxysilane; when n is 0 and m is 3, an example is a monoalkyltrialkoxysilane; when n is 0 and m is 4, an example is a tetraalkoxysilane; when n is 1 and m is 1, an example is a monohalogenated dialkylmonoalkoxysilane; when n is 1 and m is 2, an example is a monohalogenated monoalkyldialkoxysilane; when n is 1 and m is 3, an example is a monohalogenated trialkoxysilane; when n is 2 and m is 1, an example is a dihalogenated monoalkylmonoalkoxysilane; and when n is 2 and m is 2, an example is a dihalogenated dialkoxysilane. All of these are compounds that are reactive with the active terminal of a living polymer.

In particular, monoalkyltriaryloxysilanes in which n is 0 and m is 3 and tetraaryloxysilanes in which n is 0 and m is 4 are preferred from the viewpoints of improving processability by coupling with living polymers and imparting functional groups having high affinity with silica and the like to polymers.

Specific examples of the silane compound represented by the general formula (I) used in the present invention include tetrakis(2-ethylhexyloxy)silane, methyltris(2-ethylhexyloxy)silane, ethyltris(2-ethylhexyloxy)silane, vinyltris(2-ethylhexyloxy)silane, vinyltris(2-ethylhexyloxy)silane, methylvinylbis(2-ethylhexyloxy)silane, and the like, which are alkoxy-type compounds without halogens; and tetraphenoxysilane, ethyltriphenoxysilane, vinyltriphenoxysilane, phenyltris(2-ethylhexyloxy)silane, and the like, which are aryloxy-type compounds without halogens. Examples of silanes containing halogens and containing a non-hydrolyzable alkoxy group in which R in the OR group in the formula has 4 carbon atoms include tri-t-butoxymonochlorosilane, dichloro-di-t-butoxysilane, di-t-butoxydiiodosilane, etc. Examples of silanes containing halogens and containing a non-hydrolyzable alkoxy group in which R in the OR group in the formula has 5 or more carbon atoms include monochloromethylbis(2-ethylhexyloxy)silane, monobromoisopropenylbis(2-ethylhexyloxy)silane,
Examples of the halogen-free alkoxy type include vinyltris(3-methylbutoxy)silane, methyltris(2-methylbutoxy)silane, and vinyltris(2-methylbutoxy)silane. Examples of the halogen-containing aryloxy type include triphenoxymonochlorosilane, monochloromethyldiphenoxysilane, monobromoethyldiphenoxysilane, monobromovinyldiphenoxysilane, ditolyldichlorosilane, and diphenoxydiiodosilane.

Among these silane compounds, silane compounds in which n is 0 or 1, and among these, methyltriphenoxysilane is particularly preferred. These silane compounds can be used alone or in combination of two or more.

The silane compound-modified rubbery polymer of the present invention is obtained by reacting the silane compound represented by general formula (I) with the active terminal of the living polymer. In this case, the amount of the silane compound used is preferably 1/100 of the active terminal of the living polymer.
Preferably, 0.7 molecules or more per molecule, more preferably
It is obtained by reacting 0.7 to 5.0, or more preferably 0.7 to 2.0 molecules. If the number of molecules is less than 0.7, a large amount of branched polymer is produced, the molecular weight distribution fluctuates significantly, and control of the molecular weight and molecular weight distribution becomes difficult. If the number of molecules exceeds 5.0, the effect of improving physical properties is saturated, which is not economically preferable.

In this case, it is also possible to add the silane compound in two stages, for example, by first adding a small amount of a silane compound to the active terminal of the living polymer to form a polymer having a branched structure, and then modifying the remaining active terminal with another silane compound.

In the present invention, the reaction between the active terminal of the living polymer and the silane compound having a functional group is carried out by adding the compound to a solution of the polymerization system of the living polymer, or by adding a solution of the living polymer to an organic solution containing the silane compound.

The reaction temperature is −120 to +150° C., preferably −80 to +120° C.
° C., and the reaction time is 1 minute to 5 hours, preferably 5 minutes to 2 hours.

After the reaction is complete, the solvent is removed by blowing steam into the polymer solution, or a poor solvent such as methanol is added to solidify the silane compound-modified rubbery polymer, which is then dried with a hot roll or under reduced pressure to obtain the silane compound-modified rubbery polymer.

Alternatively, the solvent can be directly removed from the polymer solution under reduced pressure to obtain a silane compound-modified rubbery polymer.

The molecular weight of the silane compound-modified rubbery polymer of the present invention can be varied over a wide range, but its Mooney viscosity (ML ₁₊₄ , 100°C) is preferably in the range of 10 to 150. If it is less than 10, the tensile properties will be poor.
If it exceeds 150, the processability will be poor and this is not preferred.

When the silane compound-modified rubbery polymer of the present invention is a copolymer, it may be a block copolymer or a random copolymer according to the structure of a living polymer.

The silane compound-modified rubber polymer of the present invention exhibits, for example, an absorption at about 1,100 cm ⁻¹ due to Si—O—C bonds and an absorption at about 1,200 cm −1 due to Si—O-φ bonds in an infrared absorption spectrum.
Absorption around 50 cm ^-1 or due to Si-C bond 1,16
The structure can be confirmed by absorption around 0 cm ⁻¹ .

Thus, the silane compound-modified rubbery polymer of the present invention has the following properties:
It is used alone or in blends with natural rubber, cis-1,4 polyisoprene, emulsion-polymerized styrene-butadiene copolymer, solution-polymerized styrene-butadiene copolymer, low-cis-1,4 polybutadiene, high-cis-1,4 polybutadiene, ethylene-propylene-diene copolymer, chloroprene, halogenated butyl rubber, NBR, etc. to form rubber compositions, but the rubber weight fraction must be at least 10% by weight, preferably at least 20% by weight. If the rubber weight fraction is less than 10% by weight, the improving effect on silica reinforcement cannot be seen.

The filler to be blended in the silane compound-modified rubbery polymer of the present invention contains silica as an essential component.

The amount of silica compounded is 5 to 2 parts by weight per 100 parts by weight of the rubber component.
If it is less than 5 parts by weight, the reinforcing effect is small, while if it exceeds 200 parts by weight, the processability and breaking properties are unfavorably deteriorated.

In addition, when the rubber composition used in the present invention is used as a tire tread rubber, the processability, abrasion resistance, cut resistance, and skid resistance can be improved by using carbon black and silica in combination as fillers compared to the use of silica alone.
The weight ratio of silica is preferably in the range of 95/5 to 10/90 in order to maintain or improve abrasion resistance, but if aesthetics or skid resistance on wet ice are important and a slight decrease in abrasion resistance is not an issue, silica alone may be used.

In addition, to prepare the rubber composition used in the present invention,
It is preferable to compound silica into the silane compound modified rubber-like polymer, compound carbon black into the other rubber, and then knead both rubber components together with other compounding ingredients, thereby selectively dispersing the filler in the rubber and achieving desired tire performance. For example,
Silane compound modified styrene-
A tire using a rubber composition obtained by kneading a butadiene rubber compounded with silica, a butadiene rubber compounded with carbon black, and other rubber compounding agents,
Tires made using a rubber composition obtained by kneading silane compound-modified butadiene rubber with silica and natural rubber with carbon black have excellent heat buildup and abrasion resistance, making them suitable for large tires such as truck tires and tires for large buses. Tires made using a rubber composition obtained by kneading silane compound-modified styrene-butadiene rubber with silica and natural rubber with carbon black have excellent cut resistance and heat buildup, making them suitable for construction tires and solid tires.

In addition, when the silane compound-modified rubbery polymer is used alone or in a blend with other rubbers in combination with silica and carbon black in the sidewall of a tire, damage caused by curb rub is improved compared to the use of silane alone, while rolling resistance is improved compared to the use of carbon black alone.

Furthermore, tires using a rubber composition as the white side rubber, which is obtained by compounding a silane compound-modified rubbery polymer with silica and, if necessary, a white filler such as titanium white, have increased resistance to external damage compared to tires using a rubber that is not modified with a silane compound as the white side rubber.

Furthermore, since the rubber composition of the present invention has a high stress during minute deformation, when it is used in a portion of a tire where minute deformation is required, such as a bead feeler, cornering power can be improved.
The use of the rubber composition of the present invention allows for the production of tires with excellent maneuverability and low rolling resistance due to their high hardness and low heat buildup, and provides effects that could not be achieved by increasing or decreasing the amount of carbon black. Furthermore, when the rubber composition of the present invention is used as the rubber embedded in tire cords, its low heat buildup reduces hysteresis loss due to dynamic repeated deformation experienced by the tie cords and the embedded rubber, resulting in the production of tires with low rolling resistance and high durability.

The rubber composition used in the present invention may further contain, as required, powdered fillers such as magnesium carbonate, calcium carbonate, and clay, fibrous fillers such as glass fiber and whiskers, as well as usual vulcanized rubber compounding ingredients such as zinc oxide, antioxidants, vulcanization accelerators, and vulcanizing agents.

The rubber composition may also contain dibutyltin diacetate, dibutyltin dioctoate, dibutyltin laurate, stannous trioxide, ferrous octoate, lead naphthenate, zinc caprylate, 2-ethylhexanoic acid iron, cobalt naphthenate, titanate esters, and chelate compounds, which are known as silanol condensing agents.

As described above, the rubber composition used in the present invention can dramatically improve tire performance by being used in all parts constituting a tire, such as the tread, undertread, sidewall, belt, carcass, bead, etc. Furthermore, tire performance can also be improved by using the rubber composition in a tire's chafer rubber, shoulder wedge rubber, inter-sheet rubber, and cushion rubber.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to the following examples in any way as long as it does not depart from the gist of the invention.

In the examples, parts and percentages are by weight unless otherwise specified.

In addition, various measurements in the examples were carried out according to the following methods.

The reaction of the active terminals of the living polymer with the silane compound was confirmed by the change in Mooney viscosity and infrared absorption spectrum of the copolymer before and after the reaction.

The Mooney viscosity was measured at a temperature of 100°C after 1 minute of preheating and 4 minutes of measurement.

The microstructure of the butadiene portion was determined by infrared absorption spectroscopy (Morello method).

The styrene content was measured by infrared absorption spectroscopy based on the absorption of phenyl groups at 699 cm ⁻¹ using a previously prepared calibration curve.

The glass transition temperature (Tg) was measured using a low-temperature DSC (Digital Scanning Calorimeter) manufactured by Rigaku Electric Co., Ltd.
Measurements were carried out using a CN8208A2 model low-temperature DSC DTA, a CN8059L2 model unit, and a PTC-10A model programmable temperature controller, based on a previously determined calibration curve.

The vulcanization properties were measured in accordance with JIS K6301.

The Lambourn abrasion index, which is an abrasion resistance test, was measured using the Lambourn abrasion method. The measurement conditions were a load of 4.5 kg,
The surface speed of the grinding wheel was 100 m/sec, the test piece speed was 130 m/sec, the slip ratio was 30%, the sand drop rate was 20 g/min, and the measurement temperature was room temperature.

The Lambourn abrasion index is calculated by taking the value of unmodified styrene-butadiene copolymer (vinyl content = 60%, styrene content = 20%) as 100. The higher the value, the better the abrasion resistance.
Good abrasion resistance.

The internal loss (tanδ) was measured using a viscoelasticity spectrometer manufactured by Iwamoto Seisakusho Co., Ltd. under the conditions of a tensile dynamic strain of 1%, a frequency of 10 Hz, and 50°C. The test specimen was a slab sheet with a thickness of approximately 2 mm and a width of 5 mm, and the sample was sandwiched at a distance of 2 cm.
The initial weight was set at 100g.

The rolling resistance index was evaluated using the following formula, calculated from the moment of inertia at a given speed after the tire was placed in contact with a drum with an outer diameter of 1.7 m and the drum was rotated and then increased to a certain speed.

Wet skid resistance was evaluated by measuring the distance from when the wheels locked to when the vehicle stopped suddenly at a speed of 80 km/h on a wet concrete road surface with 3 mm of water, and then evaluating the skid resistance of the test tire using the following formula.

Slip resistance on ice was measured by braking suddenly from a speed of 80 km/h on an ice surface at an ice surface temperature of -20°C, measuring the distance from when the wheels locked to when the car came to a stop, and calculating an index using the same formula as for skid resistance above.

The wear resistance index was evaluated by running the tire for 40,000 km, measuring the remaining groove depth at 10 points, and using the average value according to the following formula.

The drum heat generation temperature was measured by filling the test tire with the normal internal pressure, pressing it against a drum testing machine with an outer diameter of 1.7 m and a speed of 60 km/h under a normal load, and running it for 3 hours, and then measuring the surface temperature at the center of the tread.

The cut resistance index is calculated by driving a vehicle 3,000 km on rough roads with many protruding rocks, such as quarries, and then evaluating the number of large cuts (scratches 5 mm or more deep) and small cuts (scratches 1 mm to less than 5 mm deep) per 100 ^cm2 of the tread surface. The higher the number, the better the performance.

Maneuverability is tested in accordance with the US standard ASTM F516-77.
Evaluated.

The sidewall wear resistance index was evaluated by measuring the amount of wear after a certain distance of cornering on a test course, and then using an index to evaluate the wear. A higher index indicates better performance.

The side damage was evaluated by striking a rubber block on the side of the tire with a steel blade from a certain height using a pendulum-type impact cut tester, measuring the depth of the cut, and expressing it as an index.
The larger the value, the better the side trauma resistance.

The drum bead durability index was determined by filling the test tire to the normal internal pressure, pressing it against a drum testing machine with an outer diameter of 1.8 m and a speed of 70 km/h under a normal load, and measuring the crack length in the bead section after running 10,000 km, and then indexing it using the following formula.

The temperature of the belt portion heated by the drum was measured by filling the test tire with the normal internal pressure, pressing it against a drum testing machine with an outer diameter of 1.7 m and a speed of 60 km/h under the normal load, and running it for 3 hours, and then measuring the temperature of the belt portion after running.

Reference Example 1 A 5-volume autoclave equipped with a stirrer and a jacket was dried and purged with nitrogen. 2,500 g of previously purified and dried cyclohexane, 100 g of styrene,
400 g of 1,3-butadiene and 25 g of tetrahydrofuran were then introduced. The temperature inside the autoclave was then raised to 10°C, and the cooling water was stopped while stirring at 2 revolutions per minute. 0.300 g of n-butyllithium was added and polymerized for 30 minutes. A portion of this polymer solution was taken out and measured for Mooney viscosity (ML ₁₊₄ , 100
The temperature (°C) was measured and found to be below 14°C.

Next, 9.38 ml of a cyclohexane solution of monomethyltriphenoxysilane (concentration 0.50 mol/L) was added to the remaining polymer solution.
When the solution was added (the molar ratio of monomethyltriphenoxysilane to n-butyllithium was 1.00), the yellow-red color of the living anions disappeared and the solution viscosity increased. The reaction was then continued at 50°C for 30 minutes.

After a predetermined time, 0.7 g of 2,6-di-t-butylphenol (BHT) was added per 100 g of polymer, and after steam desolvation, the mixture was heated at 100°C.
The polymer was dried on a heated roll at 100°C. The yield of the polymer was almost quantitative.

In the following reference examples, the polymer yield was also quantitative.

This polymer was dissolved in tetrahydrofuran without any insoluble matter, and the infrared absorption spectrum of this modified polymer showed absorption at 1250 cm ^-1 due to the Si-O-φ bond.

On the other hand, when the resin was molded using a hot roll and then steam-heated under the same conditions as above, the Mooney viscosity was
The value was 43, almost the same as before treatment.

The silane compound-modified rubber polymer was vulcanized according to the following formulation, and its physical properties were evaluated: The polymer, silica, DBTDL, stearic acid, and zinc oxide were premixed using a heated roll at 145°C, and then the remaining ingredients were mixed using a roll at 50°C.

This compound was molded and press-vulcanized at 145° C. The vulcanization was carried out in the same manner in all of the following reference examples. The results of this reference example are shown in Table 1. Compounding Treatment (parts) Polymer 100 Silica (Nipsil VN3, Nippon Silica Co., Ltd.) 40 Stearic acid 2 Zinc oxide 3 Antioxidant: 810NA ^*1 1 Same as TP ^*2 0.8 Vulcanization accelerator: D ^*3 0.6 Same as DM ^*4 1.2 Sulfur 1.5 Triethanolamine 1.5 DBTDL ^*5 1.0 Total 152.6 *1) N-phenyl-N'-isopropyl-p-phenylenediamine *2) Sodium dibutyldithiocarbamate *3) Diphenylguanidine *4) Dibenzothiazyl disulfide *5) Dibutyltin dilaurate Reference Examples 2 to 8 Modification of styrene-butadiene copolymer was carried out in the same manner as in Reference Example 1, except that the monomethyltriphenoxysilane in Reference Example 1 was replaced by the silane compounds shown in Table 1 below. The polymerization results and the vulcanized physical properties of the resulting polymer are shown in Table 1.

Reference Example 9 Modification of a styrene-butadiene copolymer was carried out in the same manner as in Reference Example 1, except that the amount of monomethyltriphenoxysilane used was half that of Reference Example 1. The polymerization results and the vulcanization properties of the resulting polymer are shown in Table 1.

Comparative Reference Examples 1 and 2 Polymers were produced in the same manner as in Reference Example 1, except that monochlorotriethoxysilane and methyltriethoxysilane were used instead of the monomethyltriphenoxysilane in Reference Example 1. The polymerization results and the vulcanized physical properties of the obtained polymers are shown in Table 1.

Comparative Reference Example 3 A polymer was produced in the same manner as in Reference Example 1, except that it was not modified with a silane compound. The physical properties of the polymer and the vulcanized properties of the obtained polymer are shown in Table 1.

The resulting polymer was hydrolyzed by steam treatment, resulting in a high Mooney viscosity, indicating that the resulting rubber was highly hydrolyzable. Furthermore, Reference Example 1 and Comparative Reference Examples 1 to 3 demonstrate that monomethyltriphenoxysilane specifically acts to improve tensile strength and Lambourn abrasion index.

Reference Example 10: A 5-volume autoclave equipped with a stirrer and a jacket was dried and purged with nitrogen. 2,500 g of previously purified and dried cyclohexane, 500 g of 1,3-butadiene, and 25 g of tetrahydrofuran were introduced into the autoclave. The temperature inside the autoclave was then raised to 10°C, and the cooling water was stopped while stirring at 2 revolutions per minute. 0.5 g of n-butyllithium was then added.
300 g of the polymer solution was added and polymerized for 30 minutes. A portion of the polymer solution was taken out and measured for Mooney viscosity (ML ₁₊₄ , 100°C), which was 10 or less.

Next, 9.38 ml of a cyclohexane solution of monomethyltriphenoxysilane (concentration 0.50 mono/
When the solution was added (the molar ratio of monomethyltriphenoxysilane to n-butyllithium was 1.00), the yellow-red color of the living anions disappeared and the solution viscosity increased. The reaction was then continued at 50°C for 30 minutes.

After a predetermined time, 0.7 g of 2,6-di-t-butylphenol (BHT) was added per 100 g of polymer, and the solvent was removed with steam.
The polymer was dried on a heated roll at 100° C. The yield of the polymer was almost quantitative.

The polymer yield was also quantitative in the following Reference Example 11 and Comparative Reference Examples 4 and 5. As in Reference Example ¹ , this polymer did not contain any insoluble matter when dissolved in tetrahydrofuran. In addition, the infrared absorption spectrum of this modified polymer showed a Si
Absorption due to the -O-φ bond was present.

Next, this polymer was evaluated in the same manner as in Reference Example 1.
Vulcanized compounds were also prepared. The polymer bond and vulcanized physical properties of the polymer are shown in Table 2.

Reference Example 11: The same procedure as in Reference Example 10 was repeated except that tetraphenoxysilane was used instead of monomethyltriphenoxysilane.
Modification of polybutadiene polymer was carried out in the same manner as in Example 10. The polymerization results and the vulcanized physical properties of the obtained polymer are shown in Table 2.

Comparative Reference Example 4 A polymer was produced in the same manner as in Reference Example 10, except that monochlorotriethoxysilane was used instead of monomethyltriphenoxysilane in Reference Example 10. The polymerization results and the vulcanized physical properties of the obtained polymer are shown in Table 2.

Comparative Reference Example 5 A polymer was produced in the same manner as in Reference Example 10, except that it was not modified with a silane compound. The polymerization results and the vulcanized physical properties of the resulting polymer are shown in Table 2.

Comparative Test Examples 1 to 8 and Test Examples 1 to 10 Using the rubbery polymers obtained in Reference Example 1 or Reference Example 10, vulcanization was carried out in the same manner as in Reference Example 1 according to the compounding formulations shown in Table 3, and the physical properties were evaluated. The results are shown in Table 3.

In Table 3, the silane compound-modified rubbery polymer a used for compounding is the polymer obtained in Reference Example 1, and the same polymer b is the polymer obtained in Reference Example 10. On the other hand, the silane compound-unmodified polymer a' in Table 3 is the polymer obtained in the same manner as Reference Example 1 except that it was not modified with a silane compound (Mooney viscosity (ML ₁₊₄ : 100°C);
40, vinyl content: 60%, styrene content: 21%, glass transition temperature: -46°C. Polymer b' is a polymer obtained in the same manner as in Reference Example 10, except that it was not modified with a silane compound. [Mooney viscosity (ML
₁₊₄ : 100℃); 40, vinyl content; 30%, glass transition temperature;
-97°C] for Comparative Reference Example 5.

Example 1 Comparative Test Examples 1, 4, 7 and 8, and Test Examples 1, 7 and 10
The rubber composition is used as a tread rubber, and a tire size is
Tires of 165SR13 were manufactured and evaluated for rolling resistance index, skid resistance on wet roads, slip resistance on ice, and abrasion resistance index. The results are shown in Table 4.

As is clear from Table 4, tire A, which uses a rubber composition containing the conventional silane compound unmodified rubber-like polymer a' and carbon black as a filler, is insufficient in rolling resistance, skid resistance on wet roads, and slip resistance on ice. Meanwhile, tire B, which uses a rubber composition containing the polymer a' and silica as a filler, is insufficient in rolling resistance, skid resistance on wet roads, and slip resistance on ice.
Although the rolling resistance, skid resistance on wet roads, and slip resistance on ice are improved, the abrasion resistance is significantly inferior and not suitable for practical use. On the other hand, tire C, which uses a rubber composition in which silica is blended with a silane compound-modified rubbery polymer, shows improvements in all aspects compared to tire B, and although its abrasion resistance is inferior to tire A, which uses carbon black as a filler, it is still fully practical, demonstrating the effect of using a silane compound-modified rubbery polymer in the rubber component. Furthermore, tire D, which uses a rubber composition in which silica and carbon black are used as fillers in addition to a silane compound-modified rubbery polymer as a tread, shows improved rolling resistance and slip resistance with the road surface, and its abrasion resistance is also superior to tire A.
This is almost the same level as the previous model, making it suitable as an all-season tire.

Furthermore, in tire E, which uses a rubber composition in which only carbon black is blended as an inorganic filler with a silane compound-modified rubber-like polymer, the performance is equivalent to that of the unmodified rubber-like polymer, and it is clear that the modification effect cannot be achieved.

Example 2 The tread portion was divided into two parts into a cap/base structure, and the rubber compositions of Comparative Test Example 4 and Test Example 7 were used as tread cap rubber to prepare 10.00-20 truck and bus tires.
The drum heat generation temperature and cut resistance index were evaluated, and the results are shown in Table 5.

As is clear from Table 5, tire G, which uses a rubber composition in its tread, in which silica and carbon black have been blended with a silane compound-modified rubbery polymer, has improved cut resistance and heat buildup, and is suitable for use as a heavy-duty tire running on rough roads.

In contrast, tire I, which uses a rubber composition in which only carbon black is blended as an inorganic filler with a silane compound-modified rubbery polymer, exhibits the same properties as when an unmodified rubbery polymer is used, and it is clear that the modification effect cannot be achieved.

Example 3 Tires were produced and evaluated using the rubber compositions of Test Example 8 and Comparative Test Example 5 as the base tread rubber for passenger car tire 165SR13 having a tread portion with a cap/base structure. The results are shown in Table 6.

As is clear from Table 5, tire K to which the rubber composition of the present invention is applied has a rolling resistance and a rolling resistance which are lower than those of conventional tire J.
It can be seen that the handling and wear resistance are improved. In addition, since the tire of this example has a two-layer tread structure, if the thickness of the tread base rubber is appropriately selected, the slip sign becomes clearly discernible.
This example is an example of a tire for a passenger car, but when used in a large tread base rubber for a truck, bus, or construction machine, heat buildup and cut resistance can be improved.

Example 4 Passenger tires 165SR13 were manufactured and evaluated using the rubber compositions of Test Examples 1 and 7 and Comparative Test Examples 1 and 4 as sidewall rubbers. The results are also shown in Table 7.

As is clear from Table 7, the tires using the rubber composition of the present invention are improved in rolling resistance, abrasion resistance index and side damage resistance.

Example 5 Passenger car tires 165SR13 were manufactured using the rubber compositions of Test Example 1 and Comparative Test Example 4 as bead fillers. The evaluation results are shown in Table 8.

As is clear from Table 8, the tires using the rubber compositions of the present invention are improved in rolling resistance, maneuverability and durability.

Example 6 The rubber compositions of Comparative Test Example 6 and Test Example 9 were used as rubber for embedding steel cords to prepare radial tires 165SR13 for passenger cars having two steel cord belt layers, and the tires were evaluated. The results are shown in Table 9.

As is clear from Table 9, the tires using the rubber compositions of the present invention are improved in both rolling resistance and heat buildup.

INDUSTRIAL APPLICABILITY The present invention makes it possible to economically achieve simultaneous improvements in tire performance such as abrasion resistance, cut resistance, and heat buildup, as well as improvements in processability, which have been considered difficult with conventional technologies, by using a rubber composition for tires that has sufficiently high tensile strength and abrasion resistance, even in vulcanizates that use white fillers such as silica, without using large amounts of conventional reinforcing aids such as silane coupling agents.

Claims (5)

[Claims] [Claim 1] A living polymer obtained by polymerizing a monomer using an organic alkali metal catalyst has attached to its active terminal a compound represented by the following general formula: XnSi(OR) _mR'4 -m _- n (wherein X represents a halogen atom such as a chlorine atom, a bromine atom, or an iodine atom; OR represents a non-hydrolyzable alkoxy group, aryloxy group, or cycloalkoxy group having 4 to 20 carbon atoms; R' represents an alkyl group, aryl group, vinyl group, or halogenated alkyl group having 1 to 20 carbon atoms; m represents a group having 1 to 4 carbon atoms).
n is an integer from 0 to 2, and the sum of m and n is from 2 to 4
The silane compound-modified rubbery polymer obtained by reacting a silane compound represented by the formula (I) with a silane compound represented by the formula (II) is used as a rubber component.
% by weight or more and 5 to 200 parts by weight of silica per 100 parts by weight of the rubber component, and the rubber composition is applied to at least one portion of the tire rubber member. [Claim 2] A living polymer obtained by polymerizing a monomer using an organic alkali metal catalyst, wherein the active terminal of the living polymer has a group represented by the following general formula: Si(OR)mR' _4- m (wherein OR is a non-hydrolyzable alkoxy group, aryloxy group or cycloalkoxy group having 4 to 20 carbon atoms, R'
2. The tire according to claim 1, characterized in that a rubber composition containing, as a rubber component, 10% by weight or more of a silane compound-modified rubbery polymer obtained by reacting a silane compound represented by the formula (I) with a silane compound represented by the formula (I), wherein m is an alkyl group, aryl group, vinyl group or halogenated alkyl group having 1 to 20 carbon atoms, and m is an integer of 2 to 4, and containing 5 to 200 parts by weight of silica per 100 parts by weight of the rubber component, is applied to at least one location of a tire rubber member. [Claim 3] A living polymer obtained by polymerizing a monomer using an organic alkali metal catalyst has attached to its active terminal a compound of the following general formula: XnSi(OR) _mR'4 -m _- n (wherein X represents a halogen atom such as a chlorine atom, a bromine atom, or an iodine atom, OR represents a non-hydrolyzable aryloxy group having 4 to 20 carbon atoms, and R' represents an alkyl group, aryl group, vinyl group, or halogenated alkyl group having 1 to 20 carbon atoms,
wherein m is an integer of 1 to 4, n is an integer of 0 to 2, and the sum of m and n is 2 to 4.
2. The tire according to claim 1, wherein a rubber composition containing 5 to 200 parts by weight of the rubber composition per 100 parts by weight of the rubber composition is applied to at least one location of a tire rubber member. [Claim 4] A living polymer obtained by polymerizing a monomer using an organic alkali metal catalyst, wherein the active terminal of the living polymer has the following general formula: Si(OR)mR'4 _- m wherein OR is a non-hydrolyzable aryloxy group having 6 to 20 carbon atoms,
R' represents an alkyl group, an aryl group, a vinyl group or a halogenated alkyl group having 1 to 20 carbon atoms, and m is an integer of 2 to 4.
4. The tire according to claim 2 or 3, wherein a rubber composition containing 10% by weight or more of the rubber component and 5 to 200 parts by weight of silica per 100 parts by weight of the rubber component is applied to at least one location of the tire rubber member. [Claim 5] A tire described in any one of claims 1 to 4, characterized in that the silane compound-modified rubbery polymer is obtained by reacting 0.7 or more molecules of the silane compound per active end of the living polymer.