JP2018135475A - METHOD FOR TREATING ETHYLENE/α-OLEFIN/NONCONJUGATED POLYENE COPOLYMER - Google Patents

Abstract

SOLUTION: To provide a method for treating an ethylene/α-olefin/nonconjugated polyene copolymer by mixing 100 g of an ethylene/α-olefin/nonconjugated polyene copolymer (A) having an Mw/Mn of 2.0 to 3.0 with 0.00015 to 0.00080 mol of an organic peroxide (B), followed by heat treatment.EFFECT: A method for treating an ethylene/α-olefin/nonconjugated polyene copolymer of the present invention can improve processability during kneading and molding while maintaining the intrinsic performance for an ethylene/α-olefin/nonconjugated polyene copolymer having a narrow molecular weight distribution of an ethylene/α-olefin/nonconjugated polyene copolymer polymerized by using a metallocene catalyst.SELECTED DRAWING: None

Description

  The present invention relates to a method for treating an ethylene / α-olefin / non-conjugated polyene copolymer, and more specifically, while maintaining the performance inherent to the copolymer in the ethylene / α-olefin / non-conjugated polyene copolymer. Further, the present invention relates to a processing method that imparts further superior performance.

  In recent years, thermoplastic elastomers have been actively studied as recyclable rubber materials. Thermoplastic elastomers exhibit rubber elasticity like normal vulcanized rubber at room temperature, and the matrix phase plasticizes and flows at high temperatures, and can be handled in the same way as thermoplastic resins. Furthermore, energy saving and productivity improvement are possible compared with vulcanized rubber. Due to these characteristics, demand for thermoplastic elastomers is increasing mainly in the fields of automobiles, building materials, sporting goods, medical applications and industrial parts.

  Olefin-based thermoplastic elastomers are broadly classified into crosslinked and non-crosslinked types. From the viewpoint of tensile strength, elongation at break, rubber properties (for example, permanent elongation, compression set) and heat resistance, non-crosslinked types. Cross-linked olefinic thermoplastic elastomers are superior to these olefinic thermoplastic elastomers.

  However, even though it is a cross-linked olefin-based thermoplastic elastomer, its physical properties are made of a conventionally known vulcanized rubber such as natural rubber, SBR (Styrene-Butadiene-Rubber), EPDM (Ethylene / Propylene / Diene with Methylene Linkage), etc. Compared to vulcanized rubber, it is excellent in workability and energy saving, but it is still inferior in tensile strength and rubber elasticity.

Therefore, it is strongly desired to improve the tensile properties and rubber elasticity of the cross-linked olefin-based thermoplastic elastomer.
In recent years, ethylene-α-olefin-nonconjugated polyene copolymer (EPDM), which is one of the main raw materials of cross-linked olefinic thermoplastic elastomers, has been synthesized using metallocene catalysts to produce conventional Ziegler catalysts. It has been reported that EPDM that exhibits excellent physical properties can be obtained as compared with the case of using it (see, for example, Non-Patent Document 1). Specifically, EPDM polymerized with a metallocene catalyst generally has a narrow molecular weight distribution, and therefore has excellent mechanical properties.

  On the other hand, however, EPDM having a narrow molecular weight distribution such as EPDM polymerized with a metallocene catalyst has a problem of poor workability during kneading and molding.

B. A. Harrington, M. G. Williams, "RUBBER WORLD" 2004, May, p.20-26

  An object of this invention is to provide the processing method which improves the workability at the time of the kneading | mixing and shaping | molding, hold | maintaining the performance which an ethylene * alpha-olefin * nonconjugated polyene copolymer has originally.

  As a result of intensive studies to achieve the above object, the present inventors have made a small amount of peroxide act on the ethylene / α-olefin / non-conjugated polyene copolymer to produce ethylene / α-olefin / The present inventors have found that the processability during kneading and molding of a non-conjugated polyene copolymer can be improved, and the present invention has been completed.

  That is, the present invention relates to an organic peroxide (B) 0.00015 with respect to 100 g of ethylene / α-olefin / non-conjugated polyene copolymer (A) having an Mw / Mn in the range of 2.0 to 3.0. This is a method for treating an ethylene / α-olefin / non-conjugated polyene copolymer, characterized in that ˜0.00080 mol is mixed and heat-treated.

  The ethylene / α-olefin / non-conjugated polyene copolymer treatment method of the present invention is an ethylene / α-olefin having a narrow molecular weight distribution such as an ethylene / α-olefin / non-conjugated polyene copolymer polymerized using a metallocene catalyst. The olefin / non-conjugated polyene copolymer can be further improved in workability during kneading and molding while maintaining its inherent performance.

FIG. 1 is a graph showing the molecular weight distribution of rubbers obtained in Example 1 and Comparative Example 1. FIG. 2 is a graph showing the relationship between MLRA and tan δ in the rubber obtained in Example 1 and Comparative Example 1 and the known EPDM.

  The method for treating an ethylene / α-olefin / non-conjugated polyene copolymer of the present invention is an ethylene / α-olefin / non-conjugated polyene copolymer (A) having an Mw / Mn in the range of 2.0 to 3.0. The organic peroxide (B) 0.00015-0.00080 mol is mixed with respect to 100 g, and it heat-processes, It is characterized by the above-mentioned.

  The α-olefin in the ethylene / α-olefin / non-conjugated polyene copolymer (A) is preferably an α-olefin having 3 to 20 carbon atoms, for example, propylene, 1-butene, 1-pentene, 1- Examples include hexene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-eicocene. Of these, α-olefins having 3 to 8 carbon atoms such as propylene, 1-butene, 1-hexene and 1-octene are preferable. These α-olefins may be used alone or in combination of two or more.

  The non-conjugated polyene in the ethylene / α-olefin / non-conjugated polyene copolymer (A) is, for example, a non-conjugated polyene having 5 to 20 carbon atoms, preferably 5 to 10, and 1,4-pentadiene. 1,4-hexadiene, 1,5-hexadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, 2-methyl-1,5-hexadiene, 6-methyl -1,5-heptadiene, 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 4,8-dimethyl-1,4,8-decatriene, dicyclopentadiene, cyclo Hexadiene, dicyclooctadiene, methylenenorbornene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methyle 2-norbornene, 5-vinylidene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, 2,3-diisopropylidene-5-norbornene, 2- Examples thereof include ethylidene-3-isopropylidene-5-norbornene and 2-propenyl-2,2-norbornadiene. Of these, dicyclopentadiene, 5-vinylidene-2-norbornene, 5-ethylidene-2-norbornene and the like are preferable. These non-conjugated polyenes may be used alone or in combination of two or more.

  In the ethylene / α-olefin / non-conjugated polyene copolymer (A), the content of structural units derived from ethylene is preferably 40 to 72% by mass, more preferably 41 to 70% by mass, and still more preferably 42 to 65%. The content of the structural unit derived from non-conjugated polyene is preferably 2 to 15% by mass, more preferably 3 to 14% by mass, and further preferably 4 to 12% by mass.

  The ethylene / α-olefin / non-conjugated polyene copolymer (A) has Mw / Mn in the range of 2.0 to 3.0, preferably in the range of 2.5 to 3.0. Such ethylene / α-olefin / non-conjugated polyene copolymers having a narrow molecular weight distribution are generally excellent in mechanical properties and the like, and on the other hand, are often inferior in workability.

  Such an ethylene / α-olefin / non-conjugated polyene copolymer (A) having Mw / Mn in the range of 2.0 to 3.0 is obtained by, for example, converting ethylene, α-olefin and non-conjugated polyene into a metallocene catalyst. Can be obtained by copolymerization according to a conventional method. Examples of the metallocene catalyst include metallocene catalysts having a structure represented by the following formula (α) or (β).

(In formula (α), R ¹ and R ² are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and at least one of R ₁ and R ₂ is not a hydrogen atom.
R ^{3 to} R ⁶ are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. R ^{1 to} R ⁶ may be bonded to each other to form a ring. M is titanium.

Y is -O-, -S-, -NR ^* -, -PR ^* -.
Z ^{* _{is, SiR * 2, CR * 2}} , SiR * 2 SiR * 2, CR * 2 CR * 2, CR * = CR *, a CR ^* ₂ SiR ^* _2, or GeR ^* _2.

Each R ^* is independently a hydrogen atom, a hydrocarbyl group, a hydrocarbyloxy group, a silyl group, a halogenated alkyl group, or a halogenated aryl group, and when R ^* is not hydrogen, R ^* is up to 20 It has atoms other than hydrogen atoms. May be two R where Z has ^* (when R ^* is not hydrogen atom) may form a ring, R ^* may form a ring having the R ^* and Y having the Z ^*.

p is 0, 1 or 2.
q is zero or one.
However, when p is 2, q is zero, M is in the +4 oxidation state, and each X is independently methyl or benzyl.

  When p is 1, q is zero, M is in the +3 oxidation state, X is 2- (N, N-dimethyl) aminobenzyl, or M is in the +4 oxidation state, and X is 1,3-butadienyl.

  When p is 0, q is 1, M is a formal oxidation state of +2, and X ′ is 1,4-diphenyl-1,3-butadiene, 2,4-hexadiene, or 1,3-pentadiene. It is. )

(In the formula (β), each R is independently a group or hydrogen atom selected from hydrocarbyl, halohydrocarbyl, silyl, germyl and combinations thereof, and the number of atoms other than hydrogen atoms contained in the group is 20 or less.

M is titanium, zirconium or hafnium.
Y is -O-, -S-, -NR ^* -or -PR ^* -.
R ^* is a hydrogen atom, hydrocarbyl group, hydrocarbyloxy group, silyl group, halogenated alkyl group or halogenated aryl group, and when R ^* is not hydrogen, R ^* represents up to 20 non-hydrogen atoms. contains.

Z is a divalent group containing boron or a group 14 element and containing nitrogen, phosphorus, sulfur or oxygen, and the divalent group has 60 or less atoms other than hydrogen atoms. is there.
X is independently an anionic ligand having 60 or less atoms (excluding a cyclic ligand having a delocalized π bond) when a plurality of X are present.

X ′ is a neutral linking compound having 20 or less atoms.
p is 0, 1 or 2;
q is 0 or 1.

  However, when p is 2 and q is 0, M is in the +4 oxidation state, X is halide, hydrocarbyl, hydrocarbyloxy, di (hydrocarbyl) amide, di (hydrocarbyl) phosphide, hydrocarbyl sulfide, silyl group, An anionic ligand selected from a halo-substituted derivative, a di (hydrocarbyl) amino-substituted derivative, a hydrocarbyloxy-substituted derivative and a di (hydrocarbyl) phosphino-substituted derivative, wherein the number of atoms other than the hydrogen atom of X is 20 or less It is.

  When p is 1 and q is 0, M is in the +3 oxidation state and X is selected from allyl, 2- (N, N-dimethylaminomethyl) phenyl and 2- (N, N-dimethyl) aminobenzyl. Or M is in the +4 oxidation state and X is a divalent derivative of a conjugated diene, and M and X together form a metallocyclopentene group.

And when p is 0 and q is 1, M is in the +2 oxidation state, X ′ is a neutral conjugated or non-conjugated diene optionally substituted with one or more hydrocarbyl groups; Has no more than 40 carbon atoms and forms a π complex with M. )
As the organic peroxide (B), dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-diethyl-2,5-di (t-butylperoxy) hexyne-3, di-t-butylperoxide, di-t-butylperoxy-3,3,5-trimethylcyclohexane, t-dibutylhydroperoxide, etc. Can be illustrated. Of these, dicumyl peroxide, di-t-butyl peroxide, and di-t-butylperoxy-3,3,5-trimethylcyclohexane are preferable, and dicumyl peroxide is particularly preferable.

  In the processing method of the ethylene / α-olefin / non-conjugated polyene copolymer of the present invention, the organic peroxide (B) is 0.00015 to 100 g of the ethylene / α-olefin / non-conjugated polyene copolymer (A). 0.00080 mol, preferably 0.00015 to 0.00070 mol, more preferably 0.00015 to 0.00060 mol is mixed and heat treatment is performed.

  When the organic peroxide acts on polyethylene, it functions as a cross-linking agent and cross-links polyethylene. On the other hand, when it acts on polypropylene, it decomposes polypropylene and does not function as a crosslinking agent. When an organic peroxide is allowed to act on the ethylene / α-olefin / non-conjugated polyene copolymer, crosslinking occurs in the ethylene chain portion and decomposition occurs in the propylene chain portion. When the organic peroxide (B) is allowed to act on the ethylene / α-olefin / non-conjugated polyene copolymer (A) at a low ratio such as the above ratio, the balance between crosslinking and decomposition is controlled, and the copolymer ( A) causes such a change that the molecular weight distribution Mw / Mn slightly increases. As a result, the performance such as processability of the ethylene / α-olefin / non-conjugated polyene copolymer can be enhanced without significantly impairing the inherent performance of the copolymer (A).

  When using an organic peroxide as a cross-linking agent, it is usually not effective if the organic peroxide has a low ratio such as the above mass ratio ((A) / (B)). No organic peroxide is used. That is, in the processing method of the ethylene / α-olefin / non-conjugated polyene copolymer of the present invention, the organic peroxide (B) is not used as a crosslinking agent but is used as a physical property improver of the copolymer. Characterized by points.

  The mixing and heat treatment of the ethylene / α-olefin / non-conjugated polyene copolymer (A) and the organic peroxide (B) are performed by supplying the copolymer (A) and the organic peroxide (B) to the kneading apparatus. And kneading. As a kneading apparatus, a mixing roll, an intensive mixer (for example, a Banbury mixer, a kneader), a single screw or a twin screw extruder, or the like can be used. The kneading apparatus may be either a non-open type or an open type.

Mixing and heat treatment are preferably performed in an atmosphere of an inert gas such as nitrogen or carbon dioxide.
The temperature at the time of mixing and heat treatment is usually 150 to 270 ° C, preferably 170 to 250 ° C. The kneading time is usually 1 to 20 minutes, preferably 1 to 10 minutes. Further, the shear force applied is typically, 10～50,000Sec ^-1 shear rate, preferably in the range of 100~20,000sec ^-1.

  By subjecting the ethylene / α-olefin / non-conjugated polyene copolymer to the ethylene / α-olefin / non-conjugated polyene copolymer, the ethylene / α-olefin / non-conjugated polyene copolymer originally has While maintaining the performance, workability during kneading and molding is further improved. This is because the ethylene / α-olefin / non-conjugated polyene copolymer before treatment is compared with the ethylene / α-olefin / non-conjugated polyene copolymer after treatment, and after treatment, the molecular weight distribution Mw / Mn This is supported by the fact that the Mooney stress relaxation area MLRA obtained by a crosslinkability test described later is increased.

Test methods and evaluation methods performed in Examples and Comparative Examples are shown below.
(Crosslinking test)
The rubber obtained in the examples and comparative examples was subjected to a crosslinkability test using a rubber vulcanization tester (moving die rheometer (MDR), manufactured by Alpha Technologies Co., Ltd.).

  From the results of the crosslinkability test, the minimum torque “ML”, the maximum torque “MH”, TC90, ts1, and the Mooney stress relaxation area “MLRA” were measured. TC90 means the time required for the torque to rise 90% from the minimum torque ML when “maximum torque MH−minimum torque ML” is 100%. The smaller the value of TC90, the better the crosslinking speed. . ts1 is the scorch time measured by MDR at 160 ° C. MLRA was determined from the area of the stress relaxation curve for 60 seconds. Moreover, ML after rubber | curing hardening was also calculated | required.

(Roll processability evaluation)
The roll processability uses an 8-inch roll (manufactured by Nippon Roll Co., Ltd.), the surface temperature of the front roll is 50 ° C, the surface temperature of the rear roll is 50 ° C, the rotation speed of the front roll is 16 rpm, and the rotation speed of the rear roll is 18 rpm The roll gap was set to 0.2 mm, the compound was wound around a roll, and the state of the sheet was observed. Those with cracks were evaluated as bad, and those without cracks were evaluated as good.

(Molecular weight (Mn, Mw), molecular weight distribution (Mw / Mn) measurement)
The molecular weight and molecular weight distribution of the polymer was determined by liquid chromatography using TSKgelGMH6-HT × 2 and TSKgelGMH6-HTL × 2 columns (both column sizes were 7.5 mm in diameter and 300 mm in length) connected in series as columns. It was measured using a graphic (Waters Alliance / GPC2000 model). The mobile phase medium uses o-dichlorobenzene and 0.025% by mass of BHT (Takeda Pharmaceutical) as an antioxidant, the sample concentration is 0.15% (V / W), the flow rate is 1.0 mL / min, and 140 ° C. Measurements were made. As the standard polystyrene, those manufactured by Tosoh Corporation were used for molecular weights of 500 to 20,600,000. Mn, Mw and Mw / Mn were calculated by analyzing the obtained chromatogram using a calibration curve using a standard polystyrene sample by a known method using data processing software Empower2 manufactured by Waters.

(Dynamic viscoelasticity measurement)
Using a viscoelasticity measuring apparatus ARES (TA Instruments Japan Inc.), the temperature dependence of the viscosity of each sheet-like crosslinked body sample was measured under the following measurement conditions. The ratio (G ″ / G ′: loss tangent) between the storage elastic modulus (G ′) and the loss elastic modulus (G ″) obtained by the measurement was defined as tan δ.

(Measurement condition)
Frequency: 0.44 rad / s
Temperature: -70 to 80 ° C
Ramp Rate: 4.0 ° C./min Strain: 0.5%

(Shore A hardness measurement)
According to ASTM D2240, using a hydraulic hot press molding machine set at 190 ° C, the sample was heated for 5 minutes, then pressurized for 2 minutes, and immediately cooled in a cooling bath set at 20 ° C for 4 minutes to 3 mm. A press sheet having a thickness was prepared and stored for 72 hours in an environment of 23 ° C. ± 2 ° C., and then Shore A hardness was measured. In the measurement, an A-type measuring device was used, and the scale was read immediately after contact with the push needle.

(Tensile test)
A sample was punched out to produce a No. 3 dumbbell test piece described in JIS K 6251 (2001). Using this test piece, in accordance with the method defined in JIS K 6251, a tensile test was performed under the conditions of a measurement temperature of 23 ° C. and a tensile speed of 500 mm / min, and the tensile breaking point stress (T _B ) and tensile breaking point elongation (E _B ) and tensile stresses M100 and M200 were measured.

(Compression set (CS) measurement)
The compression set was measured by the following method according to JIS K6262.
The sample was compressed 25%, held at 70 ° C. for 22 hours, then released, and the thickness was measured after the test. From this result, the residual strain (compression set) after 22 hours was calculated according to the following formula.
Residual strain (%) = 100 × (pre-test thickness−post-test thickness) / (pre-test thickness−compressed thickness)

[Example 1]
Ethylene / propylene / 5-ethylidene-2-norbornene (ENB) copolymer (Mitsui EPT4045M, manufactured by Mitsui Chemicals, Inc., structural unit content derived from ethylene: 45 mass%, structural unit content derived from ENB: 7 .6 mass%, Mooney viscosity [ML _{1 + 4} (100 ° C.)]: 45) 100 g and park mill D-40 (manufactured by NOF Corporation, dicumyl peroxide (DCP) concentration: 40 mass%) 0.204 g ( Rubber A was obtained by kneading and heating 0.00030 mol) as dicumyl peroxide under the following conditions using an open roll and a heating press.
Open roll: 8 inch roll (manufactured by Nippon Roll Co., Ltd.), front roll surface temperature 50 ° C., rear roll surface temperature 50 ° C., front roll rotation speed 16 rpm, rear roll rotation speed 18 rpm, The roll gap was 0.2 mm.
-Heating press: A 50-ton press (manufactured by Kotaki Co., Ltd.) was used under the conditions of 160 ° C. and vulcanization time of 10 minutes.

  The above crosslinkability test was performed on rubber A at 160 ° C. for 30 minutes, and ML, MH, MH-ML, MLRA and ML after curing were determined. The above roll processability evaluation was performed on rubber A. The results are shown in Table 1.

  The molecular weight (Mn, Mw) and molecular weight distribution (Mw / Mn) of rubber A were determined by the above measurement method. The results are shown in Table 1 and FIG. In FIG. 1, the solid line is a curve showing the molecular weight distribution of rubber A.

  The tan δ of rubber A was determined by the above measurement method. The results are shown in Table 1 and FIG. FIG. 2 plots tan δ against MLRA. In FIG. 2, □ is a plot of rubber A. FIG. 2 also shows a plot {circle around (3)} for rubber a1 obtained in Comparative Example 1 described later, and a plot {circle around (1)} for three known EPDMs described in the following documents.

Reference: Mark. F Welker et al., 2012, A new EPDM with improved processing characteristics for automotive hose, RUBBER WORLD, April: 22-29.
The three types of EPDM are EPDM-C (MLRA: 209, tan δ: 1.25), Vistalon 6602 (MLRA: 344, tan δ: 1.01) and EPDM-B (MLRA: 1110, described in the above document). tan δ: 0.6). The MLRA and tan δ of the three types of EPDM were obtained by the same method as the method for measuring MLRA and tan δ, respectively.

80 parts by mass of carbon black and 50 parts by mass of paraffin oil were added to 100 parts by mass of rubber A, and kneaded with a Mixtron BB-2 mixer to prepare rubber composition A.
The rubber composition A was subjected to the above crosslinkability test at 170 ° C. for 20 minutes to determine ML, MH, MH-ML, TC90, and ts1. The results are shown in Table 2.

For the rubber composition A, Shore A hardness, compression set (CS), tensile breaking stress (T _B ), tensile breaking elongation (E _B ), and tensile stress M100 and M200 were determined by the above methods. The results are shown in Table 2.

[Comparative Example 1]
A rubber a1 was obtained in the same manner as in Example 1 except that Park Mill D-40 was not used.

  A crosslinkability test was performed on rubber a1 in the same manner as in Example 1 at 160 ° C. for 30 minutes, and MLRA and ML after curing were determined. The roll processability evaluation was performed on the rubber a1. The results are shown in Table 1.

  The molecular weight (Mn, Mw) and molecular weight distribution (Mw / Mn) of the rubber a1 were determined by the above measurement method. The results are shown in Table 1 and FIG. In FIG. 1, the dotted line is a curve showing the molecular weight distribution of the rubber a1.

The tan δ of the rubber a1 was determined by the above measuring method. The results are shown in Table 1 and FIG. In FIG. 2, ■ is a plot of rubber a1.
The straight line representing the relationship between MLRA and tan δ shown in FIG. 2 is obtained from the plot for rubber a1 obtained in Comparative Example 1 and the plot for known EPDM. This straight line is represented by the following formula (1).

(Tan δ) = − 0.0005 × (MLRA) +1.2044 (1)
When viewed on the same MLRA as the MLRA of rubber A, the plot □ of rubber A is located below the straight line represented by the formula (1). That is, it is presumed that the ethylene / α-olefin / non-conjugated polyene copolymer processing method of the present invention is preparing an ethylene / α-olefin / non-conjugated polyene copolymer satisfying the following formula (2). The

(Tan δ) <− 0.0005 × (MLRA) +1.244 (2)
To 100 parts by mass of rubber a1, 80 parts by mass of carbon black and 50 parts by mass of paraffin oil were added and kneaded with a Mixtron BB-2 mixer to prepare a rubber composition a1.

The rubber composition a1 was subjected to the above crosslinkability test at 170 ° C. for 20 minutes to obtain ML, MH, MH-ML, TC90, and ts1. The results are shown in Table 2.
The Shore A hardness, compression set (CS), tensile breaking stress (T _B ), tensile breaking elongation (E _B ), and tensile stress M100 and M200 were determined for the rubber composition a1 by the above methods. The results are shown in Table 2.

[Comparative Example 2]
A rubber a2 was obtained in the same manner as in Example 1 except that the amount of Park Mill D-40 used was 2.03 g (0.0030 mol as dicumyl peroxide (DCP)).

The rubber a2 was subjected to a crosslinkability test at 160 ° C. for 30 minutes in the same manner as in Example 1 to obtain TC90, ML, MH and MH-ML.
The results are shown in Table 1.

[Comparative Example 3]
A rubber a3 was obtained in the same manner as in Example 1 except that the amount of Park Mill D-40 used was 0.68 g (0.0010 mol as dicumyl peroxide (DCP)).

The rubber a3 was subjected to a crosslinkability test at 160 ° C. for 30 minutes in the same manner as in Example 1 to obtain TC90, ML, MH and MH-ML.
The results are shown in Table 1.

[Comparative Example 4]
A rubber a5 was obtained in the same manner as in Example 1 except that the amount of Park Mill D-40 used was 0.068 g (0.00010 mol as dicumyl peroxide (DCP)).

The rubber a5 was subjected to a crosslinkability test in the same manner as in Example 1 at 160 ° C. for 30 minutes to obtain TC90, ML, MH and MH-ML.
The results are shown in Table 1.

  From Table 1, the addition of 0.00030 mol of dicumyl peroxide to 100 g of ethylene / propylene / 5-ethylidene-2-norbornene copolymer slightly increases the torque of the resulting rubber and increases the MLRA after crosslinking. And it turns out that Mw / Mn becomes wide and roll workability improves.

Claims (4)

  For 100 g of ethylene / α-olefin / non-conjugated polyene copolymer (A) having Mw / Mn in the range of 2.0 to 3.0, 0.00015 to 0.00080 mol of organic peroxide (B) is added. A method for treating an ethylene / α-olefin / non-conjugated polyene copolymer comprising mixing and heat-treating.   The ethylene / α-olefin / non-conjugated polyene copolymer (A) and the organic peroxide (B) are mixed and heat-treated at a temperature of 200 to 320 ° C. using a kneader. Of ethylene / α-olefin / non-conjugated polyene copolymer.   The method for treating an ethylene / α-olefin / non-conjugated polyene copolymer according to claim 1, wherein the ethylene / α-olefin / non-conjugated polyene copolymer (A) is produced using a metallocene catalyst.   The method for treating an ethylene / α-olefin / nonconjugated polyene copolymer according to claim 1, wherein the organic peroxide (B) is dicumyl peroxide.

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