JP2003292684A - Rubber composition and tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber composition which can maintain appearance properties hardly generating cracks or discoloration on the rubber surface over a long period of time; and a tire using the same. <P>SOLUTION: This rubber composition contains (a) 100 pts.wt. rubber component comprising at least one rubber selected from the group consisting of a natural rubber, an isoprene rubber, a butadiene rubber, and a styrene-butadiene rubber and (b) 0.1-20 pts.wt. polyolefin wax of which the melting point, measured by a differential scanning calorimeter (DSC), is 70-120°C and the number average mol.wt. (Mn), measured by gel permeation chromatography (GPC), is 500-5,000. The polyolefin wax is added to 100 pts.wt. rubber component in a ratio of 0.1-10 pts.wt. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber composition and a tire. More specifically, the present invention relates to a rubber composition and a rubber composition capable of maintaining appearance for a long period of time such that cracks or discoloration of the rubber surface hardly occur. Regarding tires.

[0002]

TECHNICAL BACKGROUND OF THE INVENTION Natural rubber, synthetic rubber, and other rubbers deteriorate with time due to the environment in which they are placed, causing cracks and hardening, and their original properties deteriorate. External causes that cause such rubber aging include
Oxygen, ozone, oxidizing substances, heat, light, radiation, metals,
Mechanical fatigue and the like are mentioned, and it is considered that these cause aging together with internal factors such as rubber composition.

In order to prevent such rubber aging, various anti-aging agents are used. When roughly classified, amine-based anti-aging agents, phenol-based anti-aging agents, and wax-based anti-aging agents are used. There is. These may be used alone or mixed with each other depending on the purpose of use of the rubber composition. Among wax type anti-aging agents, paraffin wax and microcrystalline wax having high melting points include those having high ozone resistance and high sun resistance, and are widely used as wax components in anti-aging agents.

Paraffin wax and microcrystalline wax as such an anti-aging agent are deposited on the surface of the rubber composition over time due to its blooming property, and have a role of preventing the influence of external oxygen, ozone, oxidizing substances, etc. Is playing. However, these anti-aging agents with remarkable blooming often have the problem that crystals precipitated on the surface of the rubber composition are whitened to impair the appearance of the product, and the precipitation deteriorates the anti-aging effect. However, it is desirable to suppress the bloom as much as possible from the viewpoint of the durability of the anti-aging effect.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art as described above, and has a long appearance that the amount of wax bloom is suppressed and cracks and discoloration of the rubber surface hardly occur. An object of the present invention is to provide a rubber composition which can be maintained for a period of time and a tire using the same.

[0006]

SUMMARY OF THE INVENTION The rubber composition according to the present invention comprises at least one selected from the group consisting of (a) natural rubber, isoprene rubber, butadiene rubber and styrene-butadiene rubber.
The rubber component of the seed and (b) the melting point measured by a differential scanning calorimeter (DSC) is in the range of 60 to 100 ° C., and the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is 400 to Polyolefin wax in the range of 5,000 is used, and the polyolefin wax (b) is used in an amount of 0.
It is characterized by containing 1 to 10 parts by weight.

In the present invention, the polyolefin wax (b) is preferably an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 8 carbon atoms, and particularly ethylene, propylene or 1 It is preferably a copolymer with butene.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The rubber composition and tire according to the present invention will be specifically described below. [Rubber composition] The rubber composition according to the present invention comprises a rubber component (a) and a polyolefin wax (b). First, each component forming these rubber compositions will be described.

((A) Rubber Component) The rubber component (a) used in the present invention is the main component of the rubber product and imparts elasticity to the rubber product. As the rubber component, natural rubber (N
R), isoprene rubber (IR), butadiene rubber (B
R) and at least one selected from the group consisting of styrene-butadiene rubber (SBR).

As the natural rubber, natural rubber standardized by Green Book (International quality packaging standard for various grades of natural rubber) is generally used. As isoprene rubber, isoprene rubber having a specific gravity of 0.91 to 0.94 and a Mooney viscosity [ML _{1 + 4} (100 ° C.)] of 30 to 120 is generally used.

The SBR has a specific gravity of 0.91 to 0.9.
8 and the Mooney viscosity [ML _{1 + 4} (100 ° C.)] is 2
SBRs of 0 to 120 are commonly used. As the BR, BR having a specific gravity of 0.90 to 0.95 and a Mooney viscosity [ML _{1 + 4} (100 ° C.)] of 20 to 120 is generally used. The rubber component (a) may include a rubber component other than the rubber components exemplified above. Other rubber components include, for example, isoprene-isobutylene rubber (IIR) and halogenated butyl rubber (X-II
R), ethylene-propylene-diene rubber (EPDM)
Etc.

((B) Polyolefin Wax) Wax forms a thin film of wax on its surface by blooming from a rubber product. The thin film blocks ozone from the rubber product, so that the generation of cracks on the surface of the rubber product is suppressed. The polyolefin wax (b) used in the present invention is an ethylene homopolymer or a copolymer of ethylene and α-olefin.

As the α-olefin, propylene having 3 carbon atoms, 1-butene having 4 carbon atoms, 1-pentene having 5 carbon atoms, 1-hexene having 6 carbon atoms,
4-methyl-1-pentene, 1-octene having 8 carbon atoms and the like can be mentioned, with preference given to propylene, 1-butene, 1-hexene and 4-methyl-1-pentene.
The constituent unit derived from such an α-olefin is contained in a proportion of preferably 20 mol% or less, more preferably 10 mol% or less.

The polyolefin wax (b) has a number average molecular weight (Mn) measured by gel permeation chromatography (GPC) of 400 to 5,000, preferably 400 to 3,000, more preferably 400 to 100.
It is in the range of 0. When the number average molecular weight of the polyolefin wax (b) is within the above range, the blooming property of the polyolefin wax (b) can be optimized and the antiaging effect can be expected to be durable.

The polyolefin wax (b) has a melting point of 60 to 100 ° C. measured by a differential scanning calorimeter (DSC),
Preferably 70-90 ° C, more preferably 80-90 ° C
Is in the range. When the melting point of the polyolefin wax (b) is within the above range, the polyolefin wax (b) melts within the kneading temperature of a rubber compounded product such as a tire and is appropriately dispersed in rubber.

The polyolefin wax (b) has a density of 880 to 910 kg / m ³ , preferably 885 to 905 kg / m ³ , and more preferably 8 as measured by a density gradient tube method.
It is in the range of 85 to 900 kg / m ³ . If the density of the polyolefin wax (b) is within the above range, the above-mentioned melting point is optimized, so that the polyolefin wax (b) melts within the kneading temperature of a rubber compounded product such as a tire like the above-mentioned melting point. , Moderately dispersed in rubber.

The polyolefin wax has a melt viscosity at 140 ° C. of 7 to 50 mPa · s, preferably 8 to 1
It is in the range of 5 mPa · s. When the melt viscosity of the polyolefin wax (b) is within the above range, the above-mentioned number average molecular weight is optimized, the blooming property of the polyolefin wax (b) can be optimized, and the durability of the antiaging effect can be expected.

The polyolefin wax (b) has a Mw /
Mn is 3 or less, preferably 2.5 or less, more preferably 2.0 or less. When Mw / Mn is within the above range,
Since the low molecular weight component contained in the polyolefin wax (b) is reduced, it becomes easier to control the amount of bloom. The polyolefin wax (b) is ethylene,
Ethylene / α obtained from propylene or 1-butene
It is preferably an olefin copolymer, and in this case, it is preferable to contain a structural unit derived from propylene or a structural unit derived from 1-butene in a proportion of 10 mol% or less.

The polyolefin wax (b) is solid at room temperature and becomes a low viscosity liquid at 80 to 120 ° C. or higher. The polyolefin wax (b) as described above is
For example, it can be produced using the following metallocene-based catalyst comprising a metallocene compound of a transition metal selected from Group 4 of the periodic table and an organoaluminumoxy compound and / or an ionizable ionic compound.

(Metallocene Compound) The metallocene compound forming the metallocene catalyst is a metallocene compound of a transition metal selected from Group 4 of the periodic table, and a specific example is a compound represented by the following general formula (1). Is mentioned. M ¹ Lx (1) where M ¹ is a transition metal selected from Group 4 of the periodic table, x
Is the valence of the transition metal M ¹ , and L is a ligand.

Examples of the transition metal represented by M ¹ include zirconium, titanium and hafnium. L is a ligand that coordinates to the transition metal M ^1, and at least one of the ligands L is a ligand having a cyclopentadienyl skeleton, and a ligand having this cyclopentadienyl skeleton. The ligand may have a substituent. Examples of the ligand L having a cyclopentadienyl skeleton include, for example, a cyclopentadienyl group, a methylcyclopentadienyl group, an ethylcyclopentadienyl group, n- or i-propylcyclopentadienyl group, n-, i-, sec- or t
-Alkyl- or cycloalkyl-substituted cyclopentadienyl group such as butylcyclopentadienyl group, dimethylcyclopentadienyl group, methylpropylcyclopentadienyl group, methylbutylcyclopentadienyl group, methylbenzylcyclopentadienyl group And further examples include an indenyl group, a 4,5,6,7-tetrahydroindenyl group, and a fluorenyl group. Hydrogen of the ligand having the cyclopentadienyl skeleton may be substituted with a halogen atom or a trialkylsilyl group.

When the above metallocene compound has two or more ligands having a cyclopentadienyl skeleton as the ligand L, the two ligands having a cyclopentadienyl skeleton among them are It may be bonded via an alkylene group such as ethylene and propylene; a substituted alkylene group such as isopropylidene and diphenylmethylene; a silylene group or a substituted silylene group such as a dimethylsilylene group, a diphenylsilylene group and a methylphenylsilylene group.

A ligand other than the ligand having a cyclopentadienyl skeleton (ligand having no cyclopentadienyl skeleton) L is a hydrocarbon group having 1 to 12 carbon atoms,
Alkoxy group, an aryloxy group, a sulfonic acid-containing group (-SO ₃ R ^1), a halogen atom or a hydrogen atom (wherein, R ¹ represents an alkyl group, an alkyl group substituted with a halogen atom, an aryl group, optionally substituted by a halogen atom Is an aryl group or an aryl group substituted with an alkyl group.) And the like.

(Example-1 of Metallocene Compound) When the metallocene compound represented by the above general formula (1) has a transition metal valence of 4, more specifically, it is represented by the following general formula (2). To be done. R ² _k R ³ _l R ⁴ _m R ⁵ _n M ¹ (2) Here, M ¹ is a transition metal selected from Group 4 of the periodic table, R ²
Is a group (ligand) having a cyclopentadienyl skeleton, R
³ , R ⁴ and R ⁵ are each independently a group (ligand) having or not having a cyclopentadienyl skeleton.
k is an integer of 1 or more, and k + l + m + n = 4.

Examples of metallocene compounds in which M ¹ is zirconium and at least two ligands having a cyclopentadienyl skeleton are included are shown below. Bis (cyclopentadienyl) zirconium monochloride monohydride, bis (cyclopentadienyl) zirconium dichloride, bis (1-methyl-3-butylcyclopentadienyl) zirconium bis (trifluoromethanesulfonate), bis (1, 3-dimethylcyclopentadienyl)
Zirconium dichloride, etc.

Among the above compounds, compounds in which the 1,3-position-substituted cyclopentadienyl group is replaced with a 1,2-position-substituted cyclopentadienyl group can also be used. Further, as another example of the metallocene compound, the above general formula (2)
In, at least two of R ² , R ³ , R ⁴ and R ⁵ ,
For example, R ² and R ³ are groups (ligands) having a cyclopentadienyl skeleton, and these at least two groups are bound to each other via an alkylene group, a substituted alkylene group, a silylene group or a substituted silylene group. It is also possible to use a bridge type metallocene compound. At this time R
⁴ and R ⁵ are independently the same as the ligand L other than the above-mentioned ligand having a cyclopentadienyl skeleton.

Examples of such bridge-type metallocene compounds are ethylenebis (indenyl) dimethylzirconium, ethylenebis (indenyl) zirconium dichloride, isopropylidene (cyclopentadienyl-fluorenyl) zirconium dichloride, diphenylsilylenebis (indenyl) zirconium. Dichloride,
Methyl phenyl silylene bis (indenyl) zirconium dichloride etc. are mentioned.

(Example-2 of Metallocene Compound) As another example of the metallocene compound, a metallocene compound represented by the following general formula (3) and described in JP-A-4-268307 can be mentioned.

[0029]

[Chemical 1]

Here, M ¹ is a transition metal of Group 4 of the periodic table, and specific examples thereof include titanium, zirconium and hafnium. R ¹¹ and R ¹² may be the same or different and each is a hydrogen atom; an alkyl group having 1 to 10 carbon atoms; an alkoxy group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms; a carbon atom. An aryloxy group having 6 to 10 carbon atoms; an alkenyl group having 2 to 10 carbon atoms; an arylalkyl group having 7 to 40 carbon atoms; 7 to 40 carbon atoms
Or an arylalkenyl group having 8 to 40 carbon atoms; or a halogen atom, and R ¹¹ and R ¹² are preferably chlorine atoms.

R ¹³ and R ¹⁴ may be the same or different and each is a hydrogen atom; a halogen atom; an optionally halogenated alkyl group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms. _{^{; -N (R 20) 2,}} -SR 20,
-OSi (R ²⁰⁾ _3, a -Si (R ^{2 0)} ₃ or -P (R ²⁰⁾ ₂ group. Here, R ²⁰ is a halogen atom, preferably a chlorine atom; an alkyl group having 1 to 10 carbon atoms, preferably 1 to 3 carbon atoms; or an aryl group having 6 to 10 carbon atoms, preferably 6 to 8 carbon atoms. R ¹³ and R ¹⁴ are particularly preferably hydrogen atoms.

R ¹⁵ and R ¹⁶ are the same as R ¹³ and R ¹⁴ except that they do not contain a hydrogen atom, and they may be the same or different from each other, preferably the same. R ¹⁵
And R ¹⁶ is preferably an optionally halogenated alkyl group having 1 to 4 carbon atoms, specifically, methyl, ethyl, propyl, isopropyl, butyl, isobutyl,
Examples thereof include trifluoromethyl and the like, with methyl being particularly preferred.

In the above general formula (3), R ¹⁷ is selected from the following group.

[0034]

[Chemical 2]

= BR^{twenty one}, = AlR^{twenty one}, -Ge-, -Sn
-, -O-, -S-, = SO, = SO ₂, = NR^{twenty one}, =
CO, = PR^{twenty one}, = P (O) R^{twenty one}Such. M²Is silicon,
Germanium or tin, preferably silicon or germanium
It is Ni. Where R^{twenty one}, R^{twenty two}And R^{twenty three}Are each other
May be the same or different, hydrogen atom; halogen source
Child; alkyl group having 1 to 10 carbon atoms; 1 to carbon atom
10 fluoroalkyl groups; ants having 6 to 10 carbon atoms
Group; fluoroaryl group having 6 to 10 carbon atoms; charcoal
Alkoxy group having 1 to 10 elementary atoms; 2 to 10 carbon atoms
Alkenyl group of 7 to 40 carbon atoms arylalkyl
Group; arylalkenyl group having 8 to 40 carbon atoms;
Is an alkylaryl group having 7 to 40 carbon atoms.
"R^{twenty one}And R^{twenty two}Or "R^{twenty one}And R^{twenty three}Is each
May form a ring with the atoms to which they bind
Yes.

Further, R ^{17 is, = CR 21 R 22, =} SiR 21
^{R 22, = GeR 21 R 22} , -O -, - S -, = SO, = P
R ²¹ or = P (O) R ²¹ is preferred. R ¹⁸
And R ¹⁹ may be the same or different from each other, and R ²¹
The same thing as is mentioned. m and n may be the same or different from each other and are 0, 1 or 2, preferably 0 or 1, and m + n is 0, 1 or 2, preferably 0 or 1.

Examples of the metallocene compound represented by the above general formula (3) include the following compounds. rac-
Ethylene (2-methyl-1-indenyl) ² -zirconium dichloride, rac-dimethylsilylene (2-
Methyl-1-indenyl) ² -zirconium-dichloride and the like. These metallocene compounds can be produced, for example, by the method described in JP-A-4-268307.

(Example 3 of metallocene compound) As the metallocene compound, a metallocene compound represented by the following general formula (4) can be used.

[0039]

[Chemical 3]

In the formula, M ³ represents a transition metal atom of Group 4 of the periodic table, specifically titanium, zirconium, hafnium or the like. R ²⁴ and R ²⁵ may be the same or different from each other, and are a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms, a silicon-containing group, oxygen. A containing group, a sulfur containing group, a nitrogen containing group or a phosphorus containing group is shown.

R ²⁴ is preferably a hydrocarbon group,
Especially methyl, ethyl or propyl having 1 to 3 carbon atoms
Is preferably an alkyl group of R ²⁵ is preferably a hydrogen atom or a hydrocarbon group, and particularly preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms such as methyl, ethyl or propyl.

R ²⁶ , R ²⁷ , R ²⁸ and R ^{29, which} may be the same or different, are each a hydrogen atom, a halogen atom,
Hydrocarbon group having 1 to 20 carbon atoms, 1 to 20 carbon atoms
The halogenated hydrocarbon group of is shown. Of these, a hydrogen atom, a hydrocarbon group or a halogenated hydrocarbon group is preferable. Even if at least one set of R ²⁶ and R ²⁷ , R ²⁷ and R ²⁸ , R ²⁸ and R ²⁹ is combined with the carbon atom to which they are bonded to form a monocyclic aromatic ring. Good.
When there are two or more hydrocarbon groups or halogenated hydrocarbon groups in addition to the group forming an aromatic ring, they may be bonded to each other to form a ring. When R ²⁹ is a substituent other than an aromatic group, it is preferably a hydrogen atom.

X ¹ and X ² may be the same or different from each other, and are a hydrogen atom, a halogen atom, or a carbon atom number of 1 to 2.
A hydrocarbon group of 0, a halogenated hydrocarbon group of 1 to 20 carbon atoms, an oxygen-containing group or a sulfur-containing group is shown. Y is
Divalent hydrocarbon group having 1 to 20 carbon atoms, 1 carbon atom
20 divalent halogenated hydrocarbon groups, divalent silicon-containing groups, divalent germanium-containing groups, divalent tin-containing groups,
-O -, - CO -, - S -, - SO -, - SO 2 -, -
^{NR 30 -, - P (R} 30) -, - P (O) (R 30) -, - BR 30
- or -AlR ³⁰ - (provided that, R ³⁰ is a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogenated hydrocarbon group having 1 to 20 carbon atoms) shows a.

In the formula (4), R ²⁶ and R ²⁷ , R ²⁷ and R
²⁸ , R ²⁸ and R ²⁹ include a monocyclic aromatic ring formed by bonding at least one pair to each other, and examples of the ligand coordinated to M ³ include those represented by the following formulae. To be

[0045]

[Chemical 4]

(In the formula, Y is the same as that shown in the above formula.) (Example 4 of metallocene compound) As the metallocene compound, a metallocene compound represented by the following general formula (5) is used. You can also

[0047]

[Chemical 5]

In the formula, M ³ , R ²⁴ , R ²⁵ , R ²⁶ , R ²⁷ and R
²⁸ and R ²⁹ are the same as those in the above general formula (4).
Of R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ , two groups including R ²⁶ are preferably alkyl groups, and R ²⁶ and R ²⁸ , or R ²⁸ and R ²⁹ are alkyl groups. preferable. This alkyl group is preferably a secondary or tertiary alkyl group. Further, this alkyl group may be substituted with a halogen atom or a silicon-containing group, and examples of the halogen atom and the silicon-containing group include the substituents exemplified for R ²⁴ and R ²⁵ .

Of R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ , groups other than the alkyl group are preferably hydrogen atoms. Two groups selected from R ²⁶ , R ²⁷ , R ²⁸ and R ²⁹ may be bonded to each other to form a monocyclic or polycyclic ring other than an aromatic ring. Examples of the halogen atom include those similar to the above R ²⁴ and R ²⁵ .

Examples of X ¹ , X ² and Y are the same as above. Specific examples of the metallocene compound represented by the above general formula (5) are shown below. rac-dimethylsilylene-bis (4,7-dimethyl-1-indenyl)
Zirconium dichloride, rac-dimethylsilylene-
Bis (2,4,7-trimethyl-1-indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2,4,6-trimethyl-1-indenyl) zirconium dichloride and the like.

In these compounds, a transition metal compound in which zirconium metal is replaced with titanium metal or hafnium metal can also be used. The transition metal compound is
Usually used as a racemate, but R type or S type can also be used. (Example-5 of metallocene compound) As the metallocene compound, a metallocene compound represented by the following general formula (6) can also be used.

[0052]

[Chemical 6]

In the formula, M ³ , R ²⁴ , X ¹ , X ² and Y are
It is the same as the general formula (4). R ²⁴ is preferably a hydrocarbon group, and particularly preferably an alkyl group having 1 to 4 carbon atoms such as methyl, ethyl, propyl or butyl. R ²⁵ represents an aryl group having 6 to 16 carbon atoms. R ²⁵ is preferably phenyl or naphthyl. The aryl group is a halogen atom or has 1 to 20 carbon atoms.
Or a halogenated hydrocarbon group having 1 to 20 carbon atoms may be substituted.

X ¹ and X ² are preferably a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms.
Specific examples of the metallocene compound represented by the above general formula (6) are shown below. rac-dimethylsilylene-bis (4
-Phenyl-1-indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2-methyl-4)
-Phenyl-1-indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2-methyl-4)
-(Α-naphthyl) -1-indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2-methyl-4- (β-naphthyl) -1-indenyl) zirconium dichloride, rac-dimethylsilylene-bis (2
-Methyl-4- (1-anthryl) -1-indenyl)
Zirconium dichloride, etc. Further, in these compounds, a transition metal compound in which zirconium metal is replaced with titanium metal or hafnium metal can also be used.

(Example-6 of Metallocene Compound) As the metallocene compound, a metallocene compound represented by the following general formula (7) can also be used. LaM ⁴ X ³ ₂ (7) Here, M ⁴ is a metal of Group ⁴ of the periodic table or a lanthanide series. La is a derivative of the delocalized π-bonding group, and is a group that imparts a constrained geometry to the metal M ⁴ active site. X ³ may be the same or different from each other, and are a hydrogen atom, a halogen atom, a hydrocarbon group having 20 or less carbon atoms,
It is a silyl group containing 20 or less silicon or a germanyl group containing 20 or less germanium.

Among these compounds, the compound represented by the following formula (8) is preferable.

[0057]

[Chemical 7]

M ⁴ is titanium, zirconium or hafnium. X ³ is the same as that described in the general formula (7). Cp is a substituted cyclopentadienyl group which is π-bonded to M ⁴ and has a substituent Z. Z is oxygen, sulfur, boron or an element of Group 4 of the periodic table (eg silicon, germanium or tin).

Y is a ligand containing nitrogen, phosphorus, oxygen or sulfur, and Z and Y may form a condensed ring. Specific examples of the metallocene compound represented by the formula (8) are shown below. (Dimethyl (t-butylamide)
(Tetramethyl-η ⁵ -cyclopentadienyl) silane)
Titanium dichloride, ((t-butylamido) (tetramethyl- [eta] ⁵ -cyclopentadienyl) -1,2-ethanediyl) titanium dichloride and the like. In addition, in this metallocene compound, a compound in which titanium is replaced with zirconium or hafnium can be given.

(Example-7 of Metallocene Compound) As the metallocene compound, a metallocene compound represented by the following general formula (9) can also be used.

[0061]

[Chemical 8]

M ³ is a transition metal atom of Group 4 of the periodic table, specifically titanium, zirconium or hafnium, preferably zirconium. R ³¹ may be the same as or different from each other, and at least one of them is an aryl group having 11 to 20 carbon atoms, an arylalkyl group having 12 to 40 carbon atoms, or 13 to 30 carbon atoms.
40 arylalkenyl groups, alkylaryl groups having 12 to 40 carbon atoms or silicon-containing groups, or at least two adjacent groups of the groups represented by R ³¹ together with the carbon atoms to which they are bonded, It forms one or more aromatic or aliphatic rings. In this case, the ring formed by R ^31, it is 4 to 20 carbon atoms in all including carbon atoms to which R ³¹ is bonded.

Aryl group, arylalkyl group, arylalkenyl group, alkylaryl group and aromatic ring,
R ³¹ other than R ³¹ that forms an aliphatic ring is a hydrogen atom,
It is a halogen atom, an alkyl group having 1 to 10 carbon atoms, or a silicon-containing group. R ^{32 s} may be the same as or different from each other, and each is a hydrogen atom, a halogen atom, or a carbon number of 1 to 1.
0 alkyl group, C 6-20 aryl group, C 2-10 alkenyl group, C 7-40
Is an arylalkyl group, an arylalkenyl group having 8 to 40 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, a silicon-containing group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group or a phosphorus-containing group.

Further, at least two adjacent groups of the groups represented by R ³² may form a single or plural aromatic ring or aliphatic ring together with the carbon atom to which they are bonded. In this case, the ring formed by R ³² is
Carbon atoms in all including carbon atoms to which R ³² is bonded is from 4 to 20, aromatic ring, R ³² other than R ³² that forms an aliphatic ring is a hydrogen atom, a halogen atom, a carbon atom It is an alkyl group or a silicon-containing group of the numbers 1 to 10.

In the group constituted by the two groups represented by R ³² by forming one or more aromatic rings or aliphatic rings, a fluorenyl group has a structure represented by the following formula. included.

[0066]

[Chemical 9]

R ³² is preferably a hydrogen atom or an alkyl group, particularly a hydrogen atom or methyl, ethyl,
It is preferably a hydrocarbon group having 1 to 3 carbon atoms of propyl. A preferable example of the fluorenyl group having R ³² as the substituent is a 2,7-dialkyl-fluorenyl group. In this case, the alkyl group of 2,7-dialkyl has 1 to 1 carbon atoms. And the alkyl group of 5. R ³¹ and R ³² may be the same or different from each other.

R ³³ and R ³⁴ may be the same as or different from each other, and are the same as the above hydrogen atom, halogen atom, alkyl group having 1 to 10 carbon atoms, aryl group having 6 to 20 carbon atoms, and carbon atom. Alkenyl group having 2 to 10 carbon atoms, arylalkyl group having 7 to 40 carbon atoms, and 8 carbon atoms
40 arylalkenyl groups, C 7-40 alkylaryl groups, silicon-containing groups, oxygen-containing groups, sulfur-containing groups, nitrogen-containing groups or phosphorus-containing groups. At least one of R ³³ and R ³⁴ is preferably an alkyl group having 1 to 3 carbon atoms.

X ¹ and X ² may be the same or different from each other, and are a hydrogen atom, a halogen atom, or a carbon number of 1 to 2.
It is a hydrocarbon group of 0, a halogenated hydrocarbon group of 1 to 20 carbon atoms, an oxygen-containing group, a sulfur-containing group or a nitrogen-containing group, or a conjugated diene residue formed from X ¹ and X ² . The conjugated diene residue formed from X ¹ and X ² is preferably a residue of 1,3-butadiene, 2,4-hexadiene, 1-phenyl-1,3-pentadiene or 1,4-diphenylbutadiene. , These residues may be further substituted with a hydrocarbon group having 1 to 10 carbon atoms.

X ¹ and X ² are preferably a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms or a sulfur-containing group. Y is a divalent hydrocarbon group having 1 to 20 carbon atoms, a divalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a divalent silicon-containing group, a divalent germanium-containing group, a divalent Tin-containing group, -O-, -CO-, -S-,
_{-SO -, - SO 2 -,} - NR 35 -, - P (R 35) -, -
^{P (O) (R 35)} -, - BR 35 - or -AlR ³⁵ - (provided that, R ³⁵ is a hydrogen atom, a halogen atom, carbon atom 1-2
A hydrocarbon group of 0 and a halogenated hydrocarbon group of 1 to 20 carbon atoms).

Among these divalent groups, those in which the shortest connecting portion of --Y-- is composed of 1 or 2 atoms are preferable. R ³⁵ is a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a halogenated hydrocarbon group having 1 to 20 carbon atoms. Y is preferably a divalent hydrocarbon group having 1 to 5 carbon atoms, a divalent silicon-containing group or a divalent germanium-containing group, more preferably a divalent silicon-containing group, and an alkyl group. Particularly preferred is silylene, alkylarylsilylene or arylsilylene.

(Example-8 of Metallocene Compound) As the metallocene compound, a metallocene compound represented by the following general formula (9) can also be used.

[0073]

[Chemical 10]

In the formula, M ³ is a transition metal atom of Group 4 of the periodic table, specifically titanium, zirconium or hafnium, preferably zirconium. R ³⁶
May be the same or different from each other, and are a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a silicon-containing group, It is an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group or a phosphorus-containing group. The alkyl group and alkenyl group may be substituted with a halogen atom.

Of these, R ³⁶ is preferably an alkyl group, an aryl group or a hydrogen atom, particularly methyl, ethyl, n-propyl, i-propyl hydrocarbon groups having 1 to 3 carbon atoms, phenyl, It is preferably an aryl group such as α-naphthyl or β-naphthyl, or a hydrogen atom. R ^{37 s} may be the same or different from each other, and are a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 20 carbon atoms, or 2 to 2 carbon atoms.
An alkenyl group having 10 carbon atoms, an arylalkyl group having 7 to 40 carbon atoms, an arylalkenyl group having 8 to 40 carbon atoms, an alkylaryl group having 7 to 40 carbon atoms, a silicon-containing group, an oxygen-containing group, a sulfur-containing group, A nitrogen-containing group or a phosphorus-containing group. The alkyl group, aryl group, alkenyl group, arylalkyl group, arylalkenyl group and alkylaryl group may be substituted with halogen.

Of these, R ³⁷ is preferably a hydrogen atom or an alkyl group, and particularly, a hydrogen atom or a methyl, ethyl, n-propyl, i-propyl, n-butyl or tert-butyl group having 1 to 1 carbon atoms. It is preferably a hydrocarbon group of 4. Further, R ³⁶ and R ³⁷ may be the same or different from each other. One of R ³⁸ and R ³⁹ is an alkyl group having 1 to 5 carbon atoms, and the other is a hydrogen atom, a halogen atom, an alkyl group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms. , A silicon-containing group, an oxygen-containing group, a sulfur-containing group, a nitrogen-containing group or a phosphorus-containing group.

Of these, one of R ³⁸ and R ³⁹ has 1 carbon atom such as methyl, ethyl or propyl.
It is preferable that it is an alkyl group of ~ 3 and the other is a hydrogen atom. X ¹ and X ² may be the same or different from each other, and are a hydrogen atom, a halogen atom, or a carbon atom number of 1 to 20.
Hydrocarbon group, halogenated hydrocarbon group having 1 to 20 carbon atoms, oxygen-containing group, sulfur-containing group or nitrogen-containing group,
Alternatively, it is a conjugated diene residue formed from X ¹ and X ² . Of these, halogen atoms or carbon atoms of 1 to
It is preferably 20 hydrocarbon groups.

Y is a divalent hydrocarbon group having 1 to 20 carbon atoms, a divalent halogenated hydrocarbon group having 1 to 20 carbon atoms, a divalent silicon-containing group, a divalent germanium-containing group,
Divalent tin-containing group, -O-, -CO-, -S-, -SO
_{-, - SO 2 -, -} NR 40 -, - P (R 40) -, - P (O)
^{(R 40) -, - BR} 40 - or -AlR ⁴⁰ - (wherein, R
⁴⁰ represents a hydrogen atom, a halogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a halogenated hydrocarbon group having 1 to 20 carbon atoms).

Of these, Y is 2 having 1 to 5 carbon atoms.
It is preferably a divalent hydrocarbon group, a divalent silicon-containing group or a divalent germanium-containing group, more preferably a divalent silicon-containing group, and an alkylsilylene, an alkylarylsilylene or an arylsilylene. Is particularly preferable. The metallocene compounds described above may be used alone or in combination of two or more. The metallocene compound may be diluted with a hydrocarbon or a halogenated hydrocarbon before use.

(Organoaluminum Oxy Compound) The organoaluminum oxy compound may be a known aluminoxane or a benzene-insoluble organoaluminum oxy compound. Such known aluminoxane is specifically represented by the following formula.

[0081]

[Chemical 11]

Here, R is a hydrocarbon group such as a methyl group, an ethyl group, a propyl group or a butyl group, preferably a methyl group or an ethyl group, particularly preferably a methyl group, and m
Is an integer of 2 or more, preferably 5 to 40. Aluminoxane is an alkyloxyaluminum unit represented by the formula (OAl (R ′)) and an alkyloxyaluminum unit represented by the formula (OAl (R ″)) (here, R ′).
And R ″ can exemplify the same hydrocarbon group as R, and R ′ and R ″ represent different groups. ) May be formed from a mixed alkyloxyaluminum unit. The organoaluminum oxy compound may contain a small amount of an organic compound component of a metal other than aluminum.

(Ionized Ionic Compound) Examples of the ionized ionic compound (sometimes referred to as ionic ionized compound or ionic compound) include Lewis acids, ionic compounds, borane compounds and carborane compounds. it can. Examples of the Lewis acid include compounds represented by BR ₃ (R is fluorine, a phenyl group which may have a substituent such as a methyl group or a trifluoromethyl group, or fluorine.). Specific examples of the Lewis acid include trifluoroboron, triphenylboron,
Tris (4-fluorophenyl) boron, Tris (3,
5-difluorophenyl) boron, tris (4-fluoromethylphenyl) boron, tris (pentafluorophenyl) boron, tris (p-tolyl) boron, tris (o-tolyl) boron, tris (3,5-dimethylphenyl) Examples include boron.

Examples of the ionic compounds include trialkyl-substituted ammonium salts, N, N-dialkylanilinium salts, dialkylammonium salts and triarylphosphonium salts. Examples of the trialkyl-substituted ammonium salt as the ionic compound include triethylammonium tetra (phenyl) boron, tripropylammonium tetra (phenyl) boron, tri (n-butyl) ammonium tetra (phenyl) boron and the like. Examples of the dialkyl ammonium salt as the ionic compound include di (1-propyl) ammonium tetra (pentafluorophenyl) boron and dicyclohexylammonium tetra (phenyl) boron.

As the ionic compound, triphenylcarbenium tetrakis (pentafluorophenyl) is used.
Examples thereof include borate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate, and ferrocenium tetra (pentafluorophenyl) borate. As the borane compound, decaborane (9); bis [tri (n-butyl) ammonium] nonaborate, bis [tri (n-butyl) ammonium]
Examples thereof include salts of metal borane anions such as decaborate and bis [tri (n-butyl) ammonium] bis (dodecahydride dodecaborate) nickelate (III).

Examples of the carborane compound include 4-carbanonaborane (9), 1,3-dicarbanonaborane (8), bis [tri (n-butyl) ammonium] bis (undecahydride-7-carbaundecaborate). ) Salts of metal carborane anions such as nickelate (IV). Such ionized ionic compounds may be used alone or in combination of two or more. Further, the organoaluminum oxy compound and the ionized ionic compound can also be used by supporting them on the above-mentioned carrier compound.

In forming the metallocene catalyst, the following organoaluminum compounds may be used together with the organoaluminum oxy compound and / or the ionized ionic compound. (Organoaluminum compound) The organoaluminum compound used as necessary has at least 1 in the molecule.
Compounds can be used with a number of Al- carbon bond Such compounds, for example an organoaluminum compound represented by the following general formula ^{(11), (R 6)} m Al (OR 7) n H p X 4 _q ... (11) (In the formula, R ⁶ and R ⁷ may be the same as or different from each other, and are a hydrocarbon group containing usually 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms. X ⁴ is halogen. It is an atom.m
Is 0 <m ≦ 3, n is 0 ≦ n <3, p is 0 ≦ p <3, q is a number satisfying 0 ≦ q <3, and m + n + p + q
= 3. ) Examples thereof include complex alkylated products of a Group 1 metal represented by the following general formula (12) and aluminum.

[0088] (M ⁵⁾ Al (R ⁶⁾ ... (12) (wherein, M ⁵ is Li, Na or K, R ⁶ is the same as R ⁶ in the formula (11).) ( Polymerization) The polyolefin wax used in the present invention can be obtained by homopolymerizing ethylene in a normal liquid phase or by copolymerizing ethylene and α-olefin in the presence of the above metallocene catalyst. At this time, a hydrocarbon solvent is generally used, but an α-olefin may be used as a solvent. The respective monomers used here are as described above.

Polymerization methods include suspension polymerization in which a polyolefin wax is polymerized in the state of being present as particles in a solvent such as hexane, vapor phase polymerization in which a solvent is not used, and polyolefin wax at a polymerization temperature of 140 ° C. or higher. It is possible to perform solution polymerization in which is polymerized in the state of coexisting with a solvent or alone, and among them, solution polymerization is preferable in terms of economy and quality.

The polymerization reaction may be carried out by either a batch method or a continuous method. When carrying out the polymerization batchwise, the above catalyst components are used in the concentrations described below. The concentration of the metallocene compound in the polymerization system is usually 0.00005 to 0.1 mmol / liter (polymerization volume), preferably 0.0001 to 0.05 mmol / liter.

The organoaluminum oxy compound has a molar ratio of aluminum atom to transition metal in the metallocene compound in the polymerization system (Al / transition metal) of 1 to 1000.
It is supplied in an amount of 0, preferably 10-5000. The ionized ionic compound is 0.5 to 2 in terms of the molar ratio of the ionized ionic compound to the metallocene compound in the polymerization system (ionized ionic compound / metallocene compound).
It is supplied in an amount of 0, preferably 1-10.

When an organoaluminum compound is used, it is usually used in an amount of about 0 to 5 mmol / liter (polymerization volume), preferably about 0 to 2 mmol / liter. The polymerization reaction usually has a temperature of −20 to −20.
+ 150 ° C., preferably 0 to 120 ° C., more preferably 0 to 100 ° C., and the pressure exceeds 0 to 7.8 MPa (8
0 kgf / cm ² , gauge pressure) or less, preferably more than 0 and 4.9 MPa (50 kgf / cm ² , gauge pressure) or less.

At the time of polymerization, ethylene and optionally an α-olefin are supplied to the polymerization system in such an amount ratio that a polyolefin wax having the above-mentioned specific composition can be obtained. A molecular weight modifier such as hydrogen may be added during the polymerization. When the polymerization is carried out in this manner, the produced polymer is usually obtained as a polymerization liquid containing the polymer, and thus the polyolefin wax according to the present invention can be obtained by treating the polymer in a usual manner.

For the polymerization reaction, it is particularly preferable to use the catalyst containing the metallocene compound shown in (Example-6 of metallocene compound). Furthermore, in the present invention, it is preferable to produce an ethylene / α-olefin copolymer. (Modified Polyolefin Wax) The polyolefin wax used in the present invention may be a modified polyolefin wax obtained by subjecting an unmodified polyolefin wax (hereinafter also referred to as “raw material wax”) to oxidation modification or acid graft modification.

The raw material polyolefin wax is not particularly limited as long as it is an ethylene homopolymer or an ethylene / α-olefin copolymer, which can obtain a polyolefin wax having the above-mentioned properties after modification, but preferably the metallocene as described above. Produced using a system catalyst, the number average molecular weight is in the range of 400 to 1,000,
An ethylene homopolymer or an ethylene / α-olefin copolymer having a density in the range of 880 to 910 kg / m ³ and a melting point in the range of 60 to 100 ° C.

(Oxidation Modification) The oxidation-modified modified polyolefin wax is obtained by bringing the raw material polyolefin wax into contact with oxygen or an oxygen-containing gas in a molten state with stirring. The raw material polyolefin wax is usually in a molten state at a temperature of 130 to 200 ° C, preferably 140 to 170 ° C.

In the case of oxidative modification, the raw material polyolefin wax is brought into contact with oxygen or an oxygen-containing gas in a molten state with stirring to perform an oxidation reaction. The term "oxygen or oxygen-containing gas" means pure oxygen (usually Oxygen obtained by liquid air fractionation or electrolysis of water, which may contain other components to the extent of impurities), a mixed gas of pure oxygen and other gases, such as air and ozone. To be

As a method of contacting the raw material polyolefin wax with oxygen or the like, specifically, a method of continuously supplying an oxygen-containing gas from the lower portion of the reactor to contact the raw material polyolefin wax is preferable. Further, in this case, the oxygen-containing gas is 1. per minute for 1 kg of the raw material mixture.
It is preferable to supply oxygen so that the amount of oxygen is equivalent to 0 to 8.0 NL.

The acid value (JIS K5902) of the modified polyolefin wax thus obtained is preferably 6 to 30 mgKOH / g, more preferably 10 to 20.
It is mgKOH / g. Here, the acid value refers to the number of mg of potassium hydroxide required for neutralization per 1 g of the sample.

(Acid-Graft Modified) The acid-modified polyolefin wax can be prepared by a conventionally known method. For example, a raw material polyolefin wax and an unsaturated carboxylic acid or its derivative or a sulfonate can be prepared as an organic compound. Melt-kneading in the presence of a polymerization initiator such as a peroxide, or a raw material polyolefin wax and an unsaturated carboxylic acid or its derivative or a sulfonate in a solution of an organic solvent such as an organic peroxide It can be obtained by kneading in the presence of a polymerization initiator.

Examples of the unsaturated carboxylic acid or its derivative used for the acid graft modification include, for example, methyl acrylate, ethyl acrylate, butyl acrylate, acrylic acid-sec-butyl, isobutyl acrylate, propyl acrylate, acrylic acid. Isopropyl, acrylic acid-2-
Octyl, dodecyl acrylate, stearyl acrylate, hexyl acrylate, isohexyl acrylate, phenyl acrylate, 2-chlorophenyl acrylate,
Acrylic acid esters such as diethylaminoethyl acrylate, 3-methoxybutyl acrylate, diethylene glycol ethoxylate acrylate, and 2,2,2-trifluoroethyl acrylate; methyl methacrylate, ethyl methacrylate, butyl methacrylate , Sec-butyl methacrylate, isobutyl methacrylate, propyl methacrylate, isopropyl methacrylate, 2-octyl methacrylate, dodecyl methacrylate, stearyl methacrylate, stearyl methacrylate, hexyl methacrylate, decyl methacrylate, phenyl methacrylate. Methacrylic acid ester such as 2-chlorohexyl methacrylate, diethylaminoethyl methacrylate, 2-hexylethyl methacrylate, and 2,2,2-trifluoroethyl methacrylate Kinds: Maleic acid esters such as ethyl maleate, propyl maleate, butyl maleate, diethyl maleate, dipropyl maleate and dibutyl maleate: Fumarate esters such as ethyl fumarate, butyl fumarate and dibutyl fumarate; Dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid, crotonic acid, nadic acid and methylhexahydrophthalic acid;
Maleic anhydride, itaconic anhydride, citraconic anhydride,
Examples thereof include allyl succinic anhydride, glutaconic anhydride, and nadic anhydride.

The acid-grafted modified polyolefin wax has a modification amount with an unsaturated carboxylic acid or a derivative thereof of 30 to 1 per 1 g of the polymer in terms of KOH titration.
It is preferably 00 mg KOH, 30 to 60 mg
More preferably KOH. When the amount of modification with the unsaturated carboxylic acid or its derivative is within the above range, the hygroscopicity of the fine particles obtained from the aqueous dispersion is appropriate, and the water resistance and the weather resistance tend to be excellent. Further, the phase inversion after addition of water is sufficient, and the aqueous dispersion tends to be obtained in high yield.

When modified with a sulfonate,
The modification amount is preferably 0.1 to 100 mmol, and more preferably 5 to 50 mmol, per 1 g of the polymer. When the amount of modification with the sulfonate is within the above range, the non-emulsified product is less likely to be generated, and the sulfonate salt aggregates other than the emulsified substance are less likely to be generated.

(Additives) The rubber composition according to the present invention contains, if necessary, a paraffinic, naphthene-based, aromatic-based mineral oil-based softening agent or dioctyl phthalate (DO).
P), dibutyl phthalate (DBP), dioctyl separate (DOS), dioctyl adipate (DOA) and other plasticizers; vulcanization aids such as zinc oxide and stearic acid; mercaptobenzothiazole (MBT) and benzothiazyl disulfide ( MBTS), N-tert-butyl-2-
Benzothiazolylsulfenamide, (TBBS), N
-A vulcanization accelerator such as a thiazole compound such as cyclohexyl-2-benzothiazyl sulfenamide (CBS) or a guanidine compound such as diphenylguanidine (DPG); a foaming agent; an additive such as an antioxidant May be.

(Composition) The rubber composition according to the present invention contains the polyolefin wax (b) in an amount of usually 0.1 to 10 parts by weight, preferably 3 to 10 parts by weight, based on 100 parts by weight of the rubber component (a). Parts, more preferably 5 to 10 parts by weight. The content of the polyolefin wax (b) is 100 parts by weight of the rubber component,
If the amount is less than 0.1 parts by weight, the absolute amount of wax that blooms on the surface of the rubber product decreases, and cracks are likely to occur. On the other hand, when the blending ratio of the polyolefin wax (b) exceeds 10 parts by weight with respect to 100 parts by weight of the rubber component, the polyolefin wax (b) may bloom too much on the surface of the rubber product, which may cause discoloration. .

As a method for producing the rubber composition, a known method can be adopted. For example, the above components are used at 120 to 150 ° C. for 5 to 10 ° C. using a rubber kneading device such as an open roll or a Banbury mixer. A method of kneading for minutes can be mentioned. [Tire] Tire The tire according to the present invention is a tire in which at least the surface layer of the tread portion and / or the sidewall portion is obtained from the rubber composition.

In the tire of the present invention, since these parts are obtained from the above rubber composition, the wax is not bloomed on the surface thereof, and the appearance is not damaged or cracks are not generated. The tire of the present invention is obtained by vulcanizing a raw tire. At the stage of a raw tire, at least the surface layer of the tread portion and / or the sidewall portion is made of the above rubber composition. This green tire is put in a mold vulcanizer and, for example, 140 to 180 ° C., 10
After vulcanization for ~ 15 minutes, a tire is obtained.

[0108]

EFFECTS OF THE INVENTION The rubber composition according to the present invention and the tire using the same maintain the external appearance such that cracks and discoloration of the rubber surface hardly occur for a long period of time.

[0109]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to these examples.

[0110]

[Synthesis Example 1] (Synthesis of Polyolefin Wax (WAX-1)) A polyolefin wax was produced as follows using a metallocene catalyst. Hexane 7 was placed in a stainless steel autoclave with an internal volume of 2 liters that had been sufficiently replaced with nitrogen.
Charge 90 ml and 80 ml of propene and add 5 kg of hydrogen.
/ Cm ² (gauge pressure) was introduced. Then, after raising the temperature of the system to 150 ° C., triisobutylaluminum 0.3 mmol, triphenylcarbenium tetrakis (pentafluorophenyl) borate 0.04 mmol, (t-butylamido) dimethyl (tetramethyl-η
Polymerization was initiated by press-fitting with 0.002 mmol of ⁵ -cyclopentadienyl) silane titanium dichloride (manufactured by Sigma-Aldrich) with ethylene. After that, the total pressure is 30k by continuously supplying only ethylene.
Polymerization was carried out at 150 ° C. for 20 minutes while maintaining g / cm ² (gauge pressure). After stopping the polymerization by adding a small amount of ethanol to the system, unreacted ethylene was purged. The obtained polymer solution was dried under reduced pressure at 100 ° C. overnight.

As a result, Mn was 500 and the density was 8
Was 90 kg / m ^3, the ethylene polymer DSC melting temperature of 80 ° C. The (WAX-1) was obtained 27 g.

[0112]

[Synthesis Example 2] (Synthesis of polyolefin wax (WAX-2)) A polyolefin wax was produced as follows using a metallocene catalyst. Hexane 8 was placed in a stainless steel autoclave with an internal volume of 2 liters that had been fully replaced with nitrogen.
Charge 50 ml and 100 ml of propene and add 3.
5 kg / cm ² (gauge pressure) was introduced. Then, after raising the temperature of the system to 150 ° C., triisobutylaluminum 0.3 mmol, triphenylcarbenium tetrakis (pentafluorophenyl) borate 0.04 mmol, (t-butylamido) dimethyl (tetramethyl-
Polymerization was initiated by press-fitting with 0.002 mmol of η ⁵ -cyclopentadienyl) silane titanium dichloride (manufactured by Sigma-Aldrich). afterwards,
The total pressure is 30 by supplying only ethylene continuously.
Polymerization was carried out at 150 ° C. for 20 minutes while maintaining kg / cm ² (gauge pressure). After stopping the polymerization by adding a small amount of ethanol to the system, unreacted ethylene was purged. The obtained polymer solution was dried under reduced pressure at 100 ° C. overnight.

As a result, 26 g of an ethylene polymer (WAX-2) having a Mn of 1,000, a density of 884 kg / m ³ and a DSC melting point of 85 ° C. was obtained.

[0114]

[Synthesis Example 3] (Synthesis of polyolefin wax (WAX-3)) A polyolefin wax was produced as follows using a metallocene catalyst. Hexane 8 was placed in a stainless steel autoclave with an internal volume of 2 liters that had been fully replaced with nitrogen.
Charge 70 ml and propene 80 ml, hydrogen 1kg
/ Cm ² (gauge pressure) was introduced. Then, after raising the temperature of the system to 150 ° C., triisobutylaluminum 0.3 mmol, triphenylcarbenium tetrakis (pentafluorophenyl) borate 0.04 mmol, (t-butylamido) dimethyl (tetramethyl-η
Polymerization was initiated by press-fitting with 0.002 mmol of ⁵ -cyclopentadienyl) silane titanium dichloride (manufactured by Sigma-Aldrich) with ethylene. After that, the total pressure is 30k by continuously supplying only ethylene.
Polymerization was carried out at 150 ° C. for 20 minutes while maintaining g / cm ² (gauge pressure). After stopping the polymerization by adding a small amount of ethanol to the system, unreacted ethylene was purged. The obtained polymer solution was dried under reduced pressure at 100 ° C. overnight.

As a result, 35 g of an ethylene polymer (WAX-3) having a Mn of 2,000, a density of 905 kg / m ³ and a DSC melting point of 95 ° C. was obtained.

[0116]

[Synthesis Example 4] (Synthesis of polyolefin wax (WAX-4)) A polyolefin wax was produced as follows using a metallocene catalyst. Hexane 9 was placed in a stainless steel autoclave with an internal volume of 2 liters that had been fully replaced with nitrogen.
Charge 30 ml and 20 ml of propene and add 7 kg of hydrogen.
/ Cm2 (gauge pressure) was introduced. Then, after raising the temperature of the system to 150 ° C., triisobutylaluminum 0.3 mmol, triphenylcarbenium tetrakis (pentafluorophenyl) borate 0.04 mmol, (t-butylamido) dimethyl (tetramethyl-η
Polymerization was initiated by press-fitting with 0.002 mmol of ⁵ -cyclopentadienyl) silane titanium dichloride (manufactured by Sigma-Aldrich) with ethylene. After that, the total pressure is 30k by continuously supplying only ethylene.
Polymerization was carried out at 150 ° C. for 20 minutes while maintaining g / cm ² (gauge pressure). After stopping the polymerization by adding a small amount of ethanol to the system, unreacted ethylene was purged. The obtained polymer solution was dried under reduced pressure at 100 ° C. overnight. As a result, the Mn was 600 and the density was 943.
a kg / m ^3, the ethylene polymer DSC melting temperature of 118 ° C. The (WAX-4) was obtained 19 g.

[0117]

[Synthesis Example 5] (Synthesis of polyolefin wax (WAX-5)) A polyolefin wax was produced as follows using a metallocene catalyst. Hexane 9 was placed in a stainless steel autoclave with an internal volume of 2 liters that had been fully replaced with nitrogen.
Charge 45 ml and 5 ml of propene and add 1.5 k of hydrogen.
g / cm ² (gauge pressure) was introduced. Then, after raising the temperature of the system to 150 ° C., triisobutylaluminum 0.3 mmol, triphenylcarbenium tetrakis (pentafluorophenyl) borate 0.04 mmol, (t-butylamido) dimethyl (tetramethyl-η
Polymerization was initiated by press-fitting with 0.002 mmol of ⁵ -cyclopentadienyl) silane titanium dichloride (manufactured by Sigma-Aldrich) with ethylene. After that, the total pressure is 30k by continuously supplying only ethylene.
Polymerization was carried out at 150 ° C. for 20 minutes while maintaining g / cm ² (gauge pressure). After stopping the polymerization by adding a small amount of ethanol to the system, unreacted ethylene was purged. The obtained polymer solution was dried under reduced pressure at 100 ° C. overnight.

As a result, Mn was 2,000, density was 970 kg / m ³ , and DSC melting point temperature was 122 ° C.
38 g of an ethylene polymer (WAX-5) that is

[0119]

[Synthesis Example 6] (Synthesis of polyolefin wax (WAX-6)) A polyolefin wax was produced as follows using a metallocene catalyst. Hexane 8 was placed in a stainless steel autoclave with an internal volume of 2 liters that had been fully replaced with nitrogen.
Charge 70 ml and 80 ml of propene and add 0.5 hydrogen.
kg / cm ² (gauge pressure) was introduced. Then, after raising the temperature of the system to 150 ° C., triisobutylaluminum 0.3 mmol, triphenylcarbenium tetrakis (pentafluorophenyl) borate 0.04 mmol, (t-butylamido) dimethyl (tetramethyl-η
Polymerization was initiated by press-fitting with 0.002 mmol of ⁵ -cyclopentadienyl) silane titanium dichloride (manufactured by Sigma-Aldrich) with ethylene. After that, the total pressure is 30k by continuously supplying only ethylene.
Polymerization was carried out at 150 ° C. for 20 minutes while maintaining g / cm ² (gauge pressure). After stopping the polymerization by adding a small amount of ethanol to the system, unreacted ethylene was purged. The obtained polymer solution was dried under reduced pressure at 100 ° C. overnight.

As a result, 33 g of an ethylene polymer (WAX-6) having a Mn of 8,000, a density of 905 kg / m ³ and a DSC melting point of 90 ° C. was obtained.

[0121]

[Synthesis Example 7] (Synthesis of polyolefin wax (WAX-7)) A polyolefin wax was produced as follows using a Ziegler catalyst. Hexane 8 was placed in a stainless steel autoclave with an internal volume of 2 liters that had been fully replaced with nitrogen.
Charge 30ml and propene 120ml, hydrogen 6k
g / cm ² (gauge pressure) was introduced. Next, after raising the temperature in the system to 150 ° C., triethylaluminum 0.1.
Polymerization was initiated by press-fitting 5 mmol and 0.05 mmol of titanium (Ziegler catalyst) with ethylene. After that, the total pressure was maintained at 30 kg / cm ² (gauge pressure) by continuously supplying only ethylene,
Polymerization was carried out for 0 minutes. After stopping the polymerization by adding a small amount of ethanol to the system, unreacted ethylene was purged. The obtained polymer solution was dried under reduced pressure at 100 ° C. overnight.

As a result, 18 g of an ethylene polymer (WAX-7) which is a liquid wax having Mn of 500 was obtained. The polyolefin waxes (WA
Table 1 shows the physical properties of X-1 to 7).

[0123]

[Table 1]

The following were used in the following examples and comparative examples. Natural rubber: Product name RRS # 1 Polybutadiene rubber: Product name Nipol BR-1220, manufactured by Zeon Corporation Carbon black: Product name N550 diamond black E, Mitsubishi Chemical process oil: Product name KF96-100, Shin-Etsu Chemical stearin Acid: For industrial use, manufactured by Tokyo Kasei Co., Ltd. Anti-aging agent: Trade name Antigen 6C, Sumitomo Chemical Co., Ltd. Zinc oxide: Trade name Zinc Hua No. 3 Vulcanization accelerator: Trade name Nox Cellar DM, Ouchi Shinko Chemical Co., Ltd. Paraffin Wax: Product name 155, manufactured by Nippon Seiro Co., Ltd.

[0125]

Examples 1 to 3 and Comparative Examples 1 to 4 The components shown in Table 2 were blended in the proportions shown in Table 2 and kneaded at 120 ° C. for 3 minutes using a Banbury mixer to prepare rubber compositions. did.

[0126]

[Table 2]

The obtained rubber composition was molded into a sheet, and 1
The test pieces vulcanized at 50 ° C. for 30 minutes were evaluated by the following test methods. The results are shown in Table 3. [Measurement of Ozone Crack Generation Amount] The crack of each test piece was evaluated by a static test and a dynamic test based on the measuring method of JIS K6301. Evaluation was made on a scale of 5 points, and the larger the value, the better.

[Roll Processability] The processability of the unvulcanized rubber on the roll was evaluated as follows. ⊚: Good wrapping around the roll and processing without problems. ◯: Slightly wound around the roll, but can be processed without problems. (Triangle | delta): The winding pair to a roll is bad, and it cannot process unless it is a back roll with a high roll rotation speed.

X: A level at which there is no winding around the roll and processing is difficult. [Measurement of Amount of Wax Bloom] The rubber sheet was hung in a thermostatic dryer, taken out after 10 days, the bloomed wax was carefully scraped off with a cutter knife, and the weight thereof was measured. Actually, the appearance of the rubber is whitened by wax blooming, which causes a problem in most cases when the room temperature is kept at 40 ° C or lower for a long time, but when the temperature is 20 ° C or lower, the amount of wax is small, so 40 The amount of wax bloom at ℃ was measured.

The evaluation symbols indicate the following evaluations, respectively. ◎: Very low ○: Low △: Normal ×:
Many [Measurement of Discoloration Degree] The appearances of the test pieces for which the amount of dynamic ozone crack generation was measured and the test pieces exposed to 50 ppm and 40 ° C. in ozone were visually evaluated. Evaluation was made on a scale of 5 points, and the larger the value, the better.

[0131]

[Table 3]

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hideo Toyoda             580-32 Nagaura, Sodegaura-shi, Chiba Mitsui Chemicals, Inc.             Inside the company F-term (reference) 4J002 AC011 AC031 AC061 AC081                       BB002 BB032 BB052 BB152                       FD020 FD072 FD150 GN01

Claims (3)

[Claims] 1. A rubber composition comprising: (a) at least one rubber component selected from the group consisting of natural rubber, isoprene rubber, butadiene rubber and styrene-butadiene rubber; and (b) a melting point measured by a differential scanning calorimeter (DSC). Is in the range of 60 to 100 ° C., and the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) is 400 to
Polyolefin wax in the range of 5,000.
A rubber composition comprising 0.1 to 10 parts by weight with respect to 00 parts by weight. 2. The rubber composition according to claim 1, wherein the polyolefin wax (b) is an ethylene homopolymer or a copolymer of ethylene and an α-olefin having 3 to 8 carbon atoms. object. 3. The rubber composition according to claim 1, wherein the polyolefin wax (b) is a copolymer of ethylene and propylene or 1-butene.