JPH11349632A - Preparation of polymer, polymer obtained and rubber composition using the polymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a modified diene polymer having good capability of being reinforced and good filler dispersing effect, regardless of the kind of the filler, and to provide a preparation process therefor, and to obtain a rubber composition having good failure characteristics, a good wear resistance and a low heat build-up without detriment to its wet properties. SOLUTION: A preparation process of a polymer comprises steps wherein conjugated diene monomers are polymerized or copolymerized using an organic lithium compound as an initiator in a hydrocarbon solvent and its polymerizable, active end is allowed to react with a compound containing a methylene amino group of the formula (wherein R, R', R'' and R''' are each a 1-18C alkyl group, an allyl group or an aryl group; (m) and (n) are each an integer of from 1 20 and from 1 to 3, respectively).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a polymer having simultaneously high fracture characteristics, abrasion resistance and low heat build-up, a polymer obtained, and a rubber composition using the polymer. Regarding the product, more specifically, a method for producing a modified diene-based polymer in which the terminal of the polymer obtained by anionic polymerization is modified to enhance the interaction with silica and carbon black, the obtained polymer, and The present invention relates to a rubber composition using the polymer.

[0002]

2. Description of the Related Art In recent years, demands for reducing fuel consumption of automobiles have become more severe in connection with the worldwide movement of carbon dioxide emission regulation accompanying the growing concern about environmental problems. In order to respond to such a demand, a reduction in rolling resistance has also been required for tire performance. As a method of reducing the rolling resistance of a tire, a method of optimizing a tire structure has been studied, but the use of a material having lower heat generation as the rubber composition is most commonly performed.

[0003] In order to obtain such a compound rubber having a low heat build-up, many technical developments have been made so far to enhance the dispersibility of the filler used in the rubber composition. Among them, a method of modifying the end of a diene polymer obtained by anionic polymerization using alkyl lithium with a functional group having an interaction with a filler is becoming the most common method.

[0004] As the most representative of these methods, there is known a method in which carbon black is used as a filler and the polymer terminal is modified with a tin compound. (Tokuhei 5
Similarly, a method of using a carbon black to introduce an amino group into a polymer terminal has also been used. (JP-A-62-207342)

[0005] Further, in recent years, with increasing interest in the safety of automobiles, not only low fuel consumption performance, but also performance on wet road surfaces (hereinafter referred to as wet performance), particularly braking performance, has been increasing. For this reason, the performance requirements for the rubber composition of the tire tread are not limited to simply reducing the rolling resistance, but those that highly satisfy both wet performance and low fuel consumption performance are required.

[0006] As a method for obtaining a rubber composition which simultaneously gives good fuel economy and good wet performance to a tire, carbon black which has been conventionally used as a reinforcing filler is replaced with carbon black. The method using silica has already been performed.

However, it has also been clarified that when silica is used as a reinforcing filler, the breaking strength and wear resistance of the rubber composition are significantly reduced as compared with carbon black. Furthermore, the dispersibility of silica is poor, and the workability at the time of kneading has also become a major problem in actually manufacturing tires.

In order to obtain a rubber composition having good heat build-up with good productivity, not only carbon black or silica is used alone as a reinforcing filler,
Combination use of silica and carbon black, furthermore, has a wide interaction with such various fillers, and a terminal modification that can provide good dispersibility of the filler and good abrasion resistance of the rubber composition. There is a need for polymers.

However, in the techniques described above, since the development of the modifying agent has been carried out for the purpose of a single filler, regardless of the type of the filler, a terminal having sufficient interaction with the filler is used. At present, modified polymers are extremely limited.

For example, although the tin compound described above has a large dispersing effect on carbon black, silica has almost no dispersing effect, and no reinforcing effect can be observed at all.

On the other hand, a method using an alkoxysilane, which is effective in improving the dispersing effect of silica and improving the reinforcing property, described in JP-A-1-188501, JP-A-8-53513 and JP-A-8-53576. Is
Since the alkoxysilyl group has no interaction with carbon black at all, it is apparent that there is no effect when carbon black is used as the filler. The same applies to other modified polymers for silica. For example, JP-A-9-71687 and JP-A-9-208633.
Although the method using aminoacrylamide disclosed in No. 1 has a certain effect on dispersion improvement of silica, when carbon black is used, the dispersion improvement effect is hardly observed, and carbon black and silica A combined rubber composition and a rubber composition containing carbon black have a problem that hysteresis loss increases.

Further, in recent years, a method of enhancing the modifying effect by modifying the terminal of a polymer polymerized by a lithium amide initiator with alkoxysilane has been carried out (JP-A-9-208621). It is known that a rather expensive polymerization initiator is required, and that when the obtained polymer is used for a rubber composition, there is a dispersion reinforcing effect, but there is a slight problem with the workability of the rubber composition. .

A modified polymer using a modifying agent in which a dialkylamino group has been introduced into alkoxysilane has also been reported (Japanese Patent Publication No. 6-53763, Japanese Patent Publication No. 6-37663).
No. 57767). In this method, although good workability and a reinforcing effect on silica compounding and a certain dispersing effect on both silica and carbon black are obtained, carbon black is particularly preferred due to a dialkyl group type in which amino groups have little effect on carbon black. For a composition having a large content, a sufficient effect cannot be obtained as compared with a method using a tin-based modifier.

[0014]

It is an object of the present invention to increase the level of interaction with both carbon black and silica by simultaneously increasing the level of interaction with both carbon black and silica, which was difficult to achieve with such known methods. Regardless of the type, a modified diene polymer having good reinforcing properties and a filler dispersing effect, and to provide a method for producing the same, furthermore, without impairing wet properties, good breaking properties,
An object of the present invention is to provide a rubber composition having abrasion resistance and low heat generation.

[0015]

The present inventors have conducted intensive studies on polymers having excellent interaction with the above-mentioned various fillers. As a result, both carbon black and silica were used as terminal modifiers for the polymers. It has been found that the use of a compound containing a methyleneamino group having a specifically favorable interaction with the compound provides an extremely excellent effect as compared with a polymer obtained by a known technique.

That is, the present invention has the following configuration. (1) After a conjugated diene monomer is polymerized or copolymerized in a hydrocarbon solvent using an organolithium compound as an initiator, a polymerized active terminal and a methyleneamino group represented by the above formula (1) are contained. A method for producing a polymer, characterized by reacting a compound to be produced. (2) The method for producing a polymer according to the above (1), wherein the polymer is a copolymer of a conjugated diene monomer and a monovinyl aromatic compound. (3) The method for producing a polymer according to the above (2), wherein the conjugated diene monomer and the vinyl aromatic hydrocarbon monomer used for copolymerization of the polymer are butadiene and styrene, respectively. (4) The method for producing a polymer according to any one of (1) to (3), wherein the methyleneamino group is (5) A polymer obtained by polymerization according to any one of the above (1) to (4). (6) The glass transition point measured by DSC is -90 ° C-
The polymer according to the above (5), wherein the temperature is 30 ° C. (7) Mooney viscosity (ML _{1 +} 4/100 ° C) 10-1
The polymer according to the above (5) or (6), which is 50. (8) The polymer according to any one of (5) to (7) is contained in a rubber component in an amount of 30% by weight or more, and silica or carbon black or both are used in an amount of 10 to 10 parts by weight of the rubber component. A rubber composition comprising 100 parts by weight.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The polymer of the present invention is obtained by polymerizing or copolymerizing a conjugated diene monomer in a hydrocarbon solvent using an organolithium compound as an initiator. It is obtained by reacting a compound containing a methyleneamino group represented by (Formula 1).

The conjugated diene monomer used in the present invention includes, for example, 1,3-butadiene, isoprene,
3-pentadiene, 2,3-dimethylbutadiene, 2-
Examples thereof include phenyl-1,3-butadiene and 1,3-hexadiene. These may be used alone or in combination of two or more. Among them, 1,
3-butadiene.

The vinyl aromatic hydrocarbon monomer used for copolymerization with a conjugated diene monomer includes styrene, α-methylstyrene, 1-vinylnaphthalene,
Examples thereof include vinyltoluene, ethylvinylbenzene, divinylbenzene, 4-cyclohexylstyrene, and 2,4,6-trimethylstyrene. Among them, styrene is preferred.

Further, when copolymerization is carried out using a conjugated diene monomer and a vinyl aromatic hydrocarbon as the monomer, it is practical to use 1,3-butadiene and styrene, respectively, particularly in order to easily convert the monomer. It is particularly preferable because it is available and has excellent anionic polymerization characteristics in terms of living properties and the like.

Examples of the initiator used for the polymerization include a hydrocarbon compound of lithium metal and the like. Preferably,
A lithium compound having 2 to 20 carbon atoms,
Specifically, ethyl lithium, n-propyl lithium,
i-propyl lithium, n-butyl lithium, sec-butyl lithium, t-octyl lithium, n-decyl lithium, phenyl lithium, 2-naphthyl lithium, 2-
Butyl-phenyllithium, 4-phenyl-butyllithium, cyclohexyllithium, 4-cyclopentyllithium, and reaction products of diisopropenylbenzene and butyllithium. The amount of the initiator used is 100
It is usually used in the range of 0.2 to 20 mmol per g.

The polymers of the present invention are run in solvents that do not destroy the organolithium initiator, such as hydrocarbon solvents. Suitable hydrocarbon solvents are selected from aliphatic hydrocarbons, aromatic hydrocarbons and alicyclic hydrocarbons, especially propane having 3 to 8 carbon atoms, n-butane, i-butane, n-pentane, i-pentane, n-hexane, cyclohexane,
Preferred are propene, 1-butene, i-butene, trans-2-butene, cis-2-butene, 1-pentene, 2-pentene, 1-hexene, 2-hexene, benzene, toluene, xylene, ethylbenzene and the like. These solvents can be used as a mixture of two or more kinds.

The concentration of the monomer in the solvent is usually 5 to
It is 50% by weight, preferably 10 to 30% by weight. In the case of copolymerization of a conjugated diene monomer and a vinyl aromatic hydrocarbon,
The content of the vinyl aromatic hydrocarbon in the charged monomer mixture is preferably 3 to 50% by weight, more preferably 5 to 45% by weight.
% By weight.

In the present invention, a known randomizer can be used for anionic polymerization of the conjugated diene monomer. The randomizer referred to here is a control of the microstructure of the conjugated diene polymer, for example, an increase in 1,2 bonds in a butadiene portion of a butadiene polymer or a butadiene-styrene polymer, an increase in 3,4 bonds in an isoprene polymer, and the like. Control of the composition distribution of the monomer units of the conjugated diene monomer vinyl aromatic hydrocarbon copolymer, for example, a compound having an action of randomizing butadiene units and styrene units of a butadiene-styrene copolymer. The randomizer of the present invention is not particularly limited, but includes all commonly used randomizers. Examples thereof include dimethoxybenzene, tetrahydrofuran, dimethoxyethane, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, bistetrahydrofurylpropane, triethylamine, pyridine, N-methylmorpholine, N, N, N ', N'-tetramethylethylenediamine, Examples thereof include ethers such as 2-dipiperidinoethane and tertiary amines. Further, potassium salts such as potassium-t-amylate and potassium-t-butoxide, and sodium salts such as sodium-t-amylate can also be used.

The randomizer is used in the range of 0.01 to 1000 molar equivalents per 1 molar equivalent of the organic lithium compound.

The terminal modifier used in the present invention must have a methyleneamino group in the molecule. The methyleneamino group has the same excellent basicity as the tertiary amino group and has little steric hindrance, and thus has the possibility of expressing various acidic functional groups and good hydrogen bonding strength.

When this terminal modifier is reacted with the active terminal of the polymer, a mixture of a nucleophilic substitution product with alkoxysilane and an addition reaction product with imine is obtained as shown in (Formula 2). It is thought that it is possible. In other words, when a nucleophilic substitution reaction occurs at the terminal of the polymer, an interaction is generated between the acidic functional group on the filler surface and the introduced methyleneamino group, and a good filler dispersing effect and a reinforcing effect are obtained. It can be expected to give at the same time. When added to the polymer terminal, it is converted to a secondary amine. Even in such a case, good silica dispersibility can be expected due to the secondary amine having a high hydrogen bond with the silanol group.

[0028]

Embedded image However, R, R ', R "and R'" have 1 to 1 carbon atoms.
8, an alkyl group, an allyl group, an aryl group, m, and
n represents an integer of 1 to 20, and an integer of 1 to 3, respectively.

The terminal modifier used in the present invention needs to have an alkoxysilyl group. The alkoxysilyl group introduced into the terminal of the polymer undergoes a condensation reaction with a silanol group on the silica surface, thereby providing an extremely high reinforcing effect due to a synergistic effect with the hydrogen bonding force of the methyleneamino group.

The terminal modifier used in the present invention may have a dimethylaminobenzene structure as a substituent of a methyleneamino group. In this case, the effect of the functional group having a strong interaction with the carbon black can further enhance the reinforcing effect with the filler.

As described above, the modified polymer can obtain good reinforcing properties in the compounding of silica and a mixture of silica and carbon black, and can obtain a compounded rubber having good abrasion characteristics and breaking characteristics.

Specific examples of the compound having a methyleneamino group used in the present invention include-(1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine and N- (1 -Methylethylidene) -3- (triethoxysilyl) -1-propanamine, N-ethylidene-3- (triethoxysilyl) -1-propanamine, N- (1-methylpropylidene) -3- (triethoxy) Silyl) -1-propanamine, N- (4-N, N
-Dimethylaminobenzylidene) -3- (triethoxysilyl) -1-propanamine;
(1-Methylpropylidene) -3- (triethoxysilyl) -1-propanamine, N- (1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine and the like are preferable.

The amount of the terminal modifier used in the present invention depends on the amount of the organic alkali metal used in the polymerization of the diene monomer.
It is usually 0.25 to 3.0 mol, preferably 0.5 to 1.5 mol, per mol. If the amount is less than 0.25 mol, the alkoxy group is undesirably consumed in the coupling reaction. On the other hand, if the amount exceeds 3 moles, an excessive amount of the modifier is wasted, and the terminal of the anionic polymerization is deactivated by impurities contained in the modifier.

As the reaction temperature of the terminal modifier of the present invention and the terminal lithium of the polymer, the polymerization temperature of the diene polymer can be used as it is. Specifically, a preferred range is 30 ° C to 100 ° C. If the temperature is lower than 30 ° C., the viscosity of the polymer tends to be too high, and if it is higher than 100 ° C., the terminal anion is easily deactivated, which is not preferable.

The timing and method of adding these terminal modifiers to the terminal of the polymer chain are not particularly limited, but generally when such modifiers are used, they are often carried out after completion of the polymerization.

The analysis of the polymer chain terminal modifying group can be performed by using high performance liquid chromatography (HPLC).

The obtained polymer or copolymer is obtained by DSC
The glass transition point (Tg) measured at −90 ° C. to −30
C. is preferred. It is difficult to obtain a polymer having a temperature of -90 ° C. or lower in the usual prescription of anionic polymerization, and a polymer having a temperature of -30 ° C. or higher becomes hard in a room temperature range and is somewhat inconvenient to be used as a rubber composition.

In the present invention, the Mooney viscosity (M
L _{1 + 4} , 100 ° C.) is 10 to 150, preferably 15 to 150.
70. If the Mooney viscosity is less than 10, sufficient rubber properties such as breaking characteristics cannot be obtained, and if it exceeds 150, workability is poor and it is difficult to knead the compound with the compounding agent.

The polymerization of the polymer of the present invention is about -80 to 150
It can be carried out at any temperature within the range of ℃, but -2
Temperatures of 0-100 ° C are preferred. Although the polymerization reaction can be carried out under the generated pressure, it is usually desirable to operate at a pressure sufficient to keep the monomer substantially in a liquid phase. That is,
The pressure depends on the particular substance to be polymerized, the diluent used and the polymerization temperature, but higher pressures can be used if desired, such pressure being applied to the reactor with a gas inert with respect to the polymerization reaction. It is obtained by an appropriate method such as pressing.

In general, it is preferred to remove water, oxygen, carbon dioxide and other catalyst poisons from all substances involved in the polymerization process, such as initiator components, solvents, monomers and the like.

In the present invention, together with the above polymer,
Rubber components commonly used in the tire industry can be used in combination. Examples of the rubber component used in combination include natural rubber and diene-based synthetic rubber. Examples of the diene-based synthetic rubber include styrene-butadiene copolymer (SBR), polybutadiene (BR), polyisoprene (IR), and butyl rubber. (IIR), ethylene-propylene copolymers, and mixtures thereof. Some of them may have a branched structure by using a polyfunctional modifier such as tin tetrachloride.

In the rubber composition of the present invention, carbon black or silica is used alone as a reinforcing filler.
Alternatively, both are used together.

The silica used in the present invention is not particularly limited, and includes, for example, wet silica (hydrous silicic acid), dry silica (silicic anhydride), calcium silicate, aluminum silicate, and the like. Preferred is wet silica, which is most remarkable in terms of the effect and the effect of achieving both wet grip properties and low rolling resistance.

The filler can be only silica. In this case, the silica is used in an amount of 10 to 100 parts by weight based on 100 parts by weight of the rubber component, and preferably 20 to 60 parts by weight from the viewpoint of the reinforcing property and the efficiency of improving various physical properties thereby. If the amount is less than 10 parts by weight, the breaking characteristics and the like are not sufficient, and if it exceeds 100 parts by weight, the workability is poor.

The carbon black used in the rubber composition of the present invention is not particularly limited.
F, HAF, ISAF, SAF and the like are used. Preferably, the iodine adsorption amount (IA) is 60 mg / g or more, and
Dibutyl phthalate oil absorption (DBP) is 80ml / 10
0 g or more of carbon black. By using carbon black, the effect of improving various physical properties increases, but in particular, HAF, ISAF, SAF, which are excellent in wear resistance,
Is preferred.

In the polymer composition of the present invention, when silica is used as a filler, a silane coupling agent can be used at the time of compounding in order to further improve its reinforcing property. ,It is as follows. Bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, 3- Mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, 3-
Nitropropyltrimethoxysilane, 3-nitropropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 2
-Chloroethyltrimethoxysilane, 2-chloroethyltriethoxysilane, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, -Triethoxysilylethyl-N, N-dimethylthiocarbamoyltetrasulfide, 3-trimethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3- Trimethoxysilylpropyl methacrylate monosulfide, bis (3-diethoxymethylsilylpropyl) tetrasulfide, 3-mercaptopropyldimethoxymethylsilane 3-nitropropyldimethoxymethylsilane, 3-chloropropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, dimethoxymethylsilylpropylbenzothiazoletetrasulfide and the like, and bis (3-triethoxy Silyl propyl)
Tetrasulfide, 3-trimethoxysilylpropylbenzothiazole tetrasulfide and the like are preferable from the viewpoint of the effect of improving the reinforcing property.

Since the polymer of the present invention has a functional group having a high affinity for silica in the molecule, even if the addition amount of the expensive silane coupling agent is reduced from the usual addition amount,
A rubber composition having the same physical properties can be obtained. Furthermore, kneading workability is improved by preventing gelation during kneading of rubber. The preferred compounding amount varies depending on the type of the silane coupling agent, the compounding amount of silica, and the like.
% By weight, preferably 5 to 15% by weight.

Examples of the vulcanizing agent include sulfur and the like. The amount of these used is preferably 0.1 to 10.0 parts by weight, more preferably 1.0 to 1.0 part by weight, based on 100 parts by weight of the rubber component. ５5.0 parts by weight. If it is less than 0.1 part by weight, the breaking strength, abrasion resistance and low heat build-up of the vulcanized rubber decrease,
If it exceeds 10.0 parts by weight, rubber elasticity is lost.

As the process oil that can be used in the rubber composition of the present invention, for example, paraffinic, naphthenic, aromatic and the like can be mentioned. For applications that emphasize tensile strength and abrasion resistance, aromatics are used, and for applications that emphasize hysteresis loss and low-temperature characteristics, naphthenes or paraffins are used. The amount used is based on 100 parts by weight of the rubber component. The amount is preferably from 0 to 100 parts by weight, and if it exceeds 100 parts by weight, the tensile strength and low heat build-up of the vulcanized rubber tend to deteriorate.

The vulcanization accelerator that can be used in the present invention is not particularly limited, but is preferably M (2-mercaptobenzothiazole), DM (dibenzothiazyl disulfide), or CZ (N-cyclohexyl-2). Benzothiazylsulfenamide) and other thiazole-based DPGs
(Diphenylguanidine) and other guadinine-based vulcanization accelerators.
The amount is preferably 0.1 to 5.0 parts by weight, more preferably 0.2 to 3.0 parts by weight, based on 0 parts by weight.

In the present invention, other additives usually used in the rubber industry, such as antioxidants, zinc oxide, stearic acid, antioxidants and antiozonants which are usually used in the rubber industry, are added. You can also.

The rubber composition of the present invention is obtained by kneading using a kneading machine such as a roll or an internal mixer. After molding, vulcanization is carried out to obtain a tire tread, an undertread, a carcass and a side. It can be used not only for tire applications such as wall and bead portions, but also for applications such as anti-vibration rubber, belts, hoses, and other industrial products, but is particularly suitably used as a rubber for tire treads.

[0053]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the present invention.

In the examples, parts and% mean parts by weight and% by weight, respectively, unless otherwise specified. Various measurements were made according to the following methods.

(1) Physical Properties of Polymer The number average molecular weight (Mn) and weight average molecular weight (M
The measurement of w) is carried out by gel permeation chromatography [GPC: Tosoh HLC-8020, column: Tosoh GMH-XL (two in series)], and monodisperse polystyrene is standardized using differential refractive index (RI). In terms of polystyrene. The Mooney viscosity of the polymer was measured using an RLM-01 tester manufactured by Toyo Seiki Co., Ltd.
The microstructure of the butadiene portion of the polymer was determined by an infrared method (Morello method). The bound styrene content in the polymer was calculated from the integral ratio of the ¹ H-NMR spectrum. The glass transition point (Tg) of the polymer was measured by using a differential thermal analyzer (DSC) Model 7 manufactured by Perkin Elmer Co., Ltd. after cooling to -100 ° C and then increasing the temperature at 10 ° C / min.

(2) Physical properties of rubber composition a) Low heat build-up Using a viscoelasticity measuring device (manufactured by Rheometrics), tan δ (50) at a temperature of 50 ° C., a strain of 5% and a frequency of 15 Hz.
° C). The smaller the tan δ (50 ° C.), the lower the heat generation. b) Wet properties Wet grip properties were measured using a Stanley London type portable skid tester. The results were expressed as an index with the control taken as 100. The larger the index, the better the performance. c) Fracture properties The strength at break (Tb), the elongation at break (Eb), and the tensile stress at 300% elongation (M ₃₀₀ ) are JIS K
Measured according to 6301-1995. d) Abrasion Resistance A Lambourn-type abrasion tester was used to measure the amount of abrasion at a slip rate of 60% at room temperature. The higher the index, the better.

(Production of Polymer) An experiment was carried out using dried and purified raw materials, unless otherwise specified, for the raw materials used in the polymerization.

In a dried and nitrogen-purged 800 ml pressure-resistant glass container, 300 g of cyclohexane, 32.5 g of 1,3-butadiene monomer, 17.5 g of styrene monomer,
Potassium-t-amylate 0.025 mmol, THF
1 mmol was injected, and n-butyllithium (Bu
Li) After adding 0.55 mmol, polymerization was carried out at 50 ° C. for 3 hours. The polymerization system was uniform and transparent without any precipitation from the start to the end of the polymerization. The polymerization conversion is approximately 1
00%.

A portion of the polymerization solution was sampled, isopropyl alcohol was added, and the solid was dried to obtain a rubbery polymer. The microstructure, molecular weight and molecular weight distribution of this polymer were measured. The results are shown in (Table 1).

The polymerization system further contains N-terminal as a terminal modifier.
(1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine (DMBTESPA) 0.55 m
After adding mol, a denaturation reaction was further performed for 30 minutes.
Thereafter, 0.5 m of a 5% solution of 2,6-di-t-butylparacresol (BHT) in isopropanol was further added to the polymerization system.
The reaction was stopped by adding 1 and the polymer A was obtained by drying according to a conventional method. The analytical values of the obtained polymer are shown in (Table 1).

Further, by replacing the amount of n-butyllithium and the type and amount of the modifier with the modifiers shown in Table 1, Polymers B to I were obtained.

The microstructure, molecular weight and molecular weight distribution of these polymers were measured in the same manner as for polymer A. The results are shown in (Table 1).

[0063]

[Table 1] BaseMw: molecular weight before denaturation reaction (Mw) TotalMw: molecular weight after denaturation reaction (Mw) Mw / Mn: molecular weight distribution after denaturation reaction METESPA: N- (1-methylethylidene) -3- (triethoxysilyl) -1 -Propanamine, ETMSPA: N-ethylidene-3- (trimethoxysilyl) -1-propanamine MPTESPA: N- (1-methylpropylidene) -3- (triethoxysilyl) -1-propanamine DMBTESPA: N- (1,3-dimethylbutylidene) -3-
(Triethoxysilyl) -1-propanamine DMABTESPA: N- (4-NN dimethylaminobenzylidene) -3- (triethoxysilyl) -1-propanamine TTC: tin tetrachloride TEOS: tetraethoxysilane DMPT: 3 -Dimethylaminopropyltriethoxysilane

Into a 800 ml pressure-resistant glass container which had been dried and purged with nitrogen, 300 g of cyclohexane, 40 g of 1,3-butadiene monomer, 10 g of styrene monomer, and 0.16 mmol of ditetrahydrofurylpropane were poured. .55 mmol of n-butyllithium (BuLi)
Was added, and polymerization was carried out at 50 ° C. for 2 hours. The polymerization system was uniformly transparent without any precipitation from the start to the end of the polymerization. The polymerization conversion was almost 100%.

A part of the polymerization solution was sampled, isopropyl alcohol was added, and the solid was dried to obtain a rubbery copolymer. The microstructure, molecular weight and molecular weight distribution of this copolymer were measured. The results are shown in (Table 2).

The polymerization system further contains N-terminal as a terminal modifier.
After adding (1,3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine and 0.55 mmol, a denaturation reaction was further performed for 30 minutes. Thereafter, 0.5 ml of a 5% solution of 2,6-di-t-butylparacresol (BHT) in isopropanol was added to the polymerization system to stop the reaction, followed by drying in a conventional manner to obtain polymer J. Was. The analytical values of the obtained polymer are shown in (Table 2).

Polymers K to N were obtained by substituting the amount of n-butyllithium and the type and amount of the modifier with the modifiers shown in Table 2.

The microstructure, molecular weight and molecular weight distribution of these polymers were measured in the same manner as for polymer L. The results are shown in (Table 2).

[0069]

[Table 2] BaseMw: molecular weight before denaturation reaction (Mw) TotalMw: molecular weight after denaturation reaction (Mw) Mw / Mn: molecular weight distribution after denaturation reaction ETMSPA: N-ethylidene-3- (trimethoxysilyl) -1-propanamine DMBTESPA: N- (1,3-dimethylbutylidene) -3-
(Triethoxysilyl) -1-propanamine DMABTESPA: N- (4-NN dimethylaminobenzylidene) -3- (triethoxysilyl) -1-propanamine TTC: tin tetrachloride TEOS: tetraethoxysilane DMPT: 3 -Dimethylaminopropyltriethoxysilane

300 g of cyclohexane, 50 g of 1,3-butadiene monomer, and 1 g of tetrahydrofuran (THF) were placed in an 800 ml pressure-resistant glass container which had been dried and purged with nitrogen.
mmol was added, and 0.55 mmol of n-butyllithium (BuLi) was added thereto, followed by polymerization at 50 ° C. for 2 hours. The polymerization system was uniformly transparent without any precipitation from the start to the end of the polymerization. The polymerization conversion is approximately 1
00%.

A part of the polymerization solution was sampled, isopropyl alcohol was added, and the solid was dried to obtain a rubbery polymer. The microstructure, molecular weight and molecular weight distribution of this polymer were measured. The results are shown in (Table 3).

In this polymerization system, DMBTESPA: N- (1,
After adding 0.55 mmol of (3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine, a denaturation reaction was further performed for 30 minutes. Thereafter, 0.5 ml of a 5% solution of isopropanol of BHT was further added to the polymerization system to stop the reaction, and the polymer was dried by a conventional method to obtain a polymer W. The analytical values of the obtained polymer are shown in (Table 3).

Polymers P and Q were obtained by replacing the amount of n-butyllithium and the type and amount of the modifier with the modifiers shown in Table 2.

[0074]

[Table 3] BaseMw: Molecular weight before denaturation reaction (Mw) TotalMw: Molecular weight after denaturation reaction (Mw) Mw / Mn: Molecular weight distribution after denaturation reaction TTC: Tin tetrachloride TEOS: Tetraethoxysilane

The polymers G, M and Q were prepared after the polymerization was completed.
Without performing a denaturation reaction, 0.5% solution of 2,6-di-t-butylparacresol (BHT) in isopropanol 0.5%
The reaction was stopped by adding ml, and the product was dried by a conventional method.

(Preparation of Rubber Composition) Using each polymer obtained as described above, based on the formulation shown in Table 4,
A rubber composition was prepared using carbon and / or silica as a filler, and the physical properties of each rubber composition were evaluated.

Examples 1 to 6 and Comparative Examples 1 to 4 Using Polymers A to I, rubber compositions were prepared according to Formulation 1 shown in Table 4 (the filler was only silica), and the physical properties were evaluated. did. The results are shown in Table 5-1. Comparative Example 1 (polymer G) was used as a control for the wet characteristics and the wear characteristics.

[0078]

[Table 4] Silica: Nipsil AQ manufactured by Nippon Silica Industry Co., Ltd. Coupling agent: Silane coupling agent manufactured by Degussa
Si69 (bis (3-triethoxysilylpropyl) tetrasulfide 6C: N- (1,3-dimethyl-butyl)
—N′-phenyl-p-phenylenediamine DPG: diphenylguanidine DM: mercaptobenzothiazyl disulfide NS: Nt-butyl-2-benzothiazylsulfenamide

[0079]

[Table 5-1]

Examples 6 to 10 and Comparative Examples 5 to 8 Next, using the same polymers A to I as in the previous study, each of the rubbers was used in the composition 2 shown in Table 4 (the filler was C / B only). A composition was prepared and its physical properties were evaluated. The results are shown in Table 5-2. Comparative Example 6 (Polymer G)
Was used as a control.

[0081]

[Table 5-2]

In both a system using silica as a filler and a system using carbon black, the conjugated diene polymers A to E of the present invention containing both alkoxysilyl groups and amino groups are used. The rubber compositions of Examples 1 to 5 are affected by the breaking property and wet performance as compared with the rubber composition of Comparative Example 2 or Comparative Example 6 using the unmodified diene polymer G. In addition, both abrasion characteristics and low heat generation are improved. In particular, in a system using carbon black as a filler, a point that has almost the same effect as a rubber composition using a polymer F modified with a tin compound, which has been considered to be very effective,
Notable. On the other hand, Comparative Examples 1 and 5 using the polymer F modified with tin tetrachloride and the system using carbon black as the filler are sufficiently effective in both low heat generation and wear characteristics. However, there is no effect in a system using silica as a filler. Comparative Example 3 using polymers H and I modified with alkoxysilane,
The rubber compositions of Nos. 4, 7 and 8 have no effect on low heat build-up or wear characteristics in a system using carbon black as a filler, and are unmodified even in a system using silica as a filler. Although it is more effective than the rubber composition using the polymer of the present invention or the tin-modified polymer, the effect is small as compared with the rubber composition using the polymer of the present invention.

As can be seen from the above formulation studies, the modified polymer according to the prior art has an effect only on silica-based fillers or an effect only on carbon, whereas the modified polymer according to the present invention has an effect only on carbon. It can be understood that the polymer using the modifier has an excellent dispersing effect as can be understood from the good low heat build-up of both fillers, and also has a reinforcing effect superior to the good wear characteristics.

Examples 11 to 16 and Comparative Examples 9 to 17 Using the polymers J to N, each rubber composition was prepared according to the formulation 3 shown in Table 4 (filler was used in combination with silica and C / B). And its physical properties were evaluated. Table 6 shows the results. Comparative Example 10 using a rubber composition containing the polymer M was used as a control for each of the wet characteristics and the wear characteristics.

[0085]

[Table 6] phr: parts by weight per 100 parts by weight of rubber component

As shown in Table 6, when the rubber composition of the present invention was used in the combination of carbon black and silica as the filler, regardless of the amount of the coupling agent, Even if not used together,
It turns out that it is especially excellent in low heat generation. In particular, in a system not using a coupling agent in combination, a clear improvement in both abrasion characteristics and low heat buildup can be confirmed with respect to a polymer using a known modifier shown in Comparative Example. In particular, even if the amount of the coupling agent is reduced from 2.5 parts by weight to 0 parts by weight per 100 parts by weight of the rubber, the rubber composition M of the present invention can suppress a decrease in abrasion characteristics and can further modify the terminal. This is almost the same as a control in which 2.5 parts by weight of a silane coupling agent was added to a polymer that was not used.

Examples 17 and 18 and Comparative Examples 18 to 20 Using Polymers A, E, F, G and H, rubber compositions were prepared according to Formulation 3 shown in Table 4 and the physical properties thereof were evaluated. . Table 7 shows the results. Comparative Example 20 (Polymer G) was used as a control for the wet characteristics and the wear characteristics. Table 7 shows the results.

[0088]

[Table 7]

As can be seen from the results, the same effect can be obtained even if the microstructure of the polymer changes.

Example 19, Comparative Examples 21 and 22 Using Polymers O, P and Q, Formulation 3 in Table 4 (filler:
A rubber composition was prepared on the basis of carbon black and silica), and the physical properties were evaluated. Table 8 shows the results. Comparative Example 22 (Polymer Q)
Was used as a control.

[0091]

[Table 8]

From the above results, even when BR having a low glass transition point is used for the main chain of the polymer, good low heat buildup and abrasion characteristics can be obtained when the polymer of the present invention is used. .

As is apparent from the above results, the rubber composition using the polymer of the present invention, which can interact with both fillers, has good filler irrespective of the type of polymer and the main chain structure. The low heat build-up property is improved by the dispersing effect, and the wear properties are improved by the reinforcing effect. This tendency is particularly remarkable in a system not using a silane coupling agent.

Further, in the rubber composition using the polymer of the present invention, even if the amount of the silane coupling agent is reduced, better low heat build-up than the rubber composition using the polymer out of the present invention is obtained. can get.

[0095]

According to the present invention, it is possible to provide a method for producing a modified diene-based polymer having enhanced interaction with both silica and carbon black, and to provide the obtained polymer. Thereby, the fracture properties, abrasion resistance, and low heat build-up of the rubber composition can be simultaneously maintained at a high level.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 15/00 C08L 15/00

Claims (8)

[Claims] After a conjugated diene monomer is polymerized or copolymerized in a hydrocarbon solvent using an organolithium compound as an initiator, the polymerizable active terminal and a methyleneamino group represented by the formula (1) are reacted. A method for producing a polymer, comprising reacting a compound contained in the polymer. Embedded image However, R, R ', R "and R'" have 1 to 1 carbon atoms.
8, an alkyl group, an allyl group, an aryl group, m, and
n represents an integer of 1 to 20, and an integer of 1 to 3, respectively. 2. The method for producing a polymer according to claim 1, wherein the polymer is a copolymer of a conjugated diene monomer and a monovinyl aromatic compound. 3. The polymer according to claim 2, wherein the conjugated diene monomer and the vinyl aromatic hydrocarbon monomer used for the copolymerization of the polymer are butadiene and styrene, respectively. Production method. 4. The method according to claim 1, wherein the methyleneamino group is an ethylideneamino group, a 1-methylpropylideneamino group, a 1,3-dimethylbutylideneamino group, a 1-methylethylideneamino group, a 4-N, N-dimethylaminobenzylideneamino group, Claims 1 to 3 characterized by the following.
Item 14. The method for producing a polymer according to any one of the above items. 5. A polymer obtained by polymerization according to any one of claims 1 to 4. 6. The glass transition point measured by DSC is -9.
The polymer according to claim 5, wherein the temperature is from 0C to -30C. 7. The polymer according to claim 5, wherein the Mooney viscosity (ML _{1 +} 4/100 ° C.) is 10 to 150. 8. A rubber component containing 30% by weight or more of the polymer according to any one of claims 5 to 7,
A rubber composition comprising 10 to 100 parts by weight of silica or carbon black or both based on 100 parts by weight of the rubber component.