JP2020073620A - Composition - Google Patents

Abstract

To provide a material composition provided with excellent roll processability same as an ethylene-α-olefin-diene copolymer in some aspects according to the present invention by improving balance between normal physical property, heat resistance and oil resistance.SOLUTION: A composition according to the present invention contains an ethylene-alkylacrylate copolymer (A component) having a peroxide crosslinking functional group, an ethylene-α-olefin-diene copolymer (B component) and a filler (C component), in which a content of the A component(pts.mass)/a content of the B component (pts.mass) is 10/90 to 70/30, and a content of the C component relative to a total of 100 pts.mass of the content of the A component and the content of the B component is 10 to 500 pts.mass.SELECTED DRAWING: None

Description

  The present invention relates to compositions.

  Although chloroprene-based polymers are inexpensive, they have poor heat resistance. Although the ethylene-alkyl acrylate copolymer is expensive and has poor roll processability, it has excellent heat aging resistance. The ethylene / α-olefin / diene copolymer is poor in oil resistance, but excellent in heat resistance and roll processability.

  A composition having an excellent balance of oil resistance, heat resistance, roll processability and price is desired.

  In order to reduce the price of the ethylene-alkyl acrylate copolymer while maintaining the performance, there is a technique in which the ethylene-alkyl acrylate copolymer is diluted with an ethylene / propylene / diene copolymer and used. However, when 50 parts or more of an ethylene / propylene / diene copolymer was blended with 100 parts of an ethylene-alkyl acrylate copolymer and amine vulcanization was carried out, the vulcanization rate decreased, which made industrial practical application difficult. (Patent Document 1).

  Moreover, in the vulcanization of the ethylene-acrylate copolymer / ethylene / propylene / diene copolymer composition in the same patent, it is described that an amine-based vulcanizing agent and a peroxide vulcanizing agent are used in combination, The difference in vulcanization rate between the ethylene-alkyl acrylate copolymer and the ethylene / propylene / diene copolymer becomes noticeable, resulting in a decrease in mechanical strength, and the oil resistance derived from the ethylene / propylene / diene copolymer. The badness of was also remarkable.

Japanese Patent No. 4462267

  It is an object of the present invention to provide such a material composition having an improved balance of normal physical properties, heat resistance and oil resistance, and good roll processability equivalent to that of an ethylene / α-olefin / diene copolymer.

  The present invention has been made to solve at least a part of the problems described above, and can be realized as the following aspects or application examples.

[Application example 1]
One aspect of the composition according to the present invention is
An ethylene-alkyl acrylate copolymer (component A) having a peroxide-crosslinkable functional group,
An ethylene / α-olefin / diene copolymer (component B),
Containing a filler (C component),
Content of component A (parts by mass) / content of component B (parts by mass) = 10/90 to 70/30,
The content of the C component is 10 to 500 parts by mass with respect to a total of 100 parts by mass of the content of the A component and the content of the B component.

[Application example 2]
In the composition described in Application Example 1,
The organic peroxide cross-linking agent (D component) may be further contained in an amount of 0.2 to 50 parts by weight based on 100 parts by weight of the total amount of the A component content and the B component content.

[Application example 3]
In the composition described in Application Example 1 or Application Example 2,
In 100 parts by mass of the component B,
The content of the repeating unit derived from a diene is 1 to 15 parts by weight,
The content of repeating units derived from ethylene is 45 to 70 parts by weight,
The Mooney viscosity ML _{1 + 4} (100 ° C.) of the component A is 25 to 100,
The ratio of the Mooney viscosity of the B component (ML _{1 + 4} (100 ° C.)-1) and the Mooney viscosity of the A component (ML _{1 + 4} (100 ° C.)-2) is
It may be (ML _{1 + 4} (100 ° C.) −2) / (ML _{1 + 4} (100 ° C.) − 1) = 1.2 or more.

[Application example 4]
In the composition according to any one of Application Example 1 to Application Example 3,
The component B may be an ethylene / propylene / diene copolymer.

[Application example 5]
In the composition according to any one of Application Example 1 to Application Example 4,
The component A may have a repeating unit derived from methyl acrylate.

  Therefore, some aspects of the present invention have been able to improve the balance of normal state physical properties, heat resistance, and oil resistance by solving the above problems. In addition, some aspects of the present invention have found a material composition having good roll processability equivalent to that of an ethylene / α-olefin / diene copolymer.

Hereinafter, preferred embodiments according to the present invention will be described in detail. The present invention is not limited to the embodiments described below, and should be understood as including various modifications that are carried out within the scope without changing the gist of the present invention. In addition, in this specification, "-(meth) acrylate" is a concept which includes both "-acrylate" and "-methacrylate." In addition, "(meth) acrylic acid ~" is a concept including both "acrylic acid ~" and "methacrylic acid ~".
(A component)
This component is an uncrosslinked rubber capable of crosslinking with a peroxide, and an ethylene-alkyl acrylate copolymer can be used. Examples thereof include those obtained by copolymerizing at least one of acrylic acid alkyl ester and acrylic acid alkoxyalkyl ester with ethylene. The composition of the present invention can use one type or two or more types of the above rubbers.

Examples of the acrylic monomer include acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, n-octyl acrylate, methoxymethyl acrylate, methoxyethyl acrylate and ethoxyethyl acrylate. Examples of the methacrylic monomer include methacrylate corresponding to the acrylic monomer.
(B component)
This component is an uncrosslinked rubber capable of crosslinking with a peroxide, and an ethylene / α-olefin / diene copolymer can be used.

  The ethylene / α-olefin / diene copolymer is a ternary copolymer obtained by copolymerizing ethylene, α-olefin and diene. Examples of the α-olefin include propylene, 1-butene, 2-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 5-methyl-1-hexene, 1-octene, 1 -Nonene, 5-ethyl-1-hexene, 1-decene, 1-dodecene, 3-methyl-1-butene and the like can be mentioned, and among these, compounds having 3 to 5 carbon atoms are preferable.

  The diene is preferably a non-conjugated diene, such as 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,7-octadiene, 1,9-decadiene, 3,6-dimethyl- 1,7-octadiene, 4,5-dimethyl-1,7-octadiene, 5-methyl-1,8-nonadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 2, 5-norbornadiene etc. are mentioned. Of these, 5-ethylidene-2-norbornene is preferred.

  The content ratio of the ethylene unit constituting the ethylene / α-olefin / diene copolymer, the unit derived from the α-olefin, and the unit derived from the diene is preferably, respectively, when the total of these units is 100% by mass. Is 45 to 70% by mass, 15 to 54% by mass and 1 to 15% by mass.

The Mooney viscosity ML _{1 + 4} (100 ° C.) of the ethylene / α-olefin / diene copolymer is preferably 25 to 100. Mooney viscosity of the ethylene-alpha-olefin-diene copolymer _{(ML 1 + 4 (100 ℃} ) -1) and ethylene - the ratio of the Mooney viscosity of the alkyl acrylate copolymer _{(ML 1 + 4 (100 ℃} ) -2), (ML 1 + 4 In the case of (100 ° C.)-2) / (ML _{1 + 4} (100 ° C.)-1) = 1.2 or more, the characteristic expression (oil resistance) of the ethylene-alkyl acrylate copolymer is promoted, and the obtained composition is Workability can be further improved. The composition of the present invention can use one type or two or more types of the above components.
(C component)
As a filler (component C), carbon black such as SRF, GPF, FEF, HAF, ISAF, SAF, FT, MT, corn starch, calcium carbonate, clay, talc, diatomaceous earth, silica, alumina, aluminum sulfate, barium sulfate, sulfuric acid. Examples thereof include calcium, basic magnesium carbonate, aluminum hydroxide, high styrene resin, coumarone indene resin, phenol resin, lignin, modified melamine resin and petroleum resin.

The composition of the present invention may use one kind or two or more kinds of the above-mentioned fillers. With respect to a total of 100 parts by weight of the ethylene-alkyl acrylate copolymer (component A) and the ethylene / α-olefin / diene copolymer (component B), preferably 10 to 500 parts by mass, more preferably 20 to 400 parts by mass. Parts, more preferably 30 to 300 parts by mass. If the proportion of the filler is less than this range, the reinforcing effect of the reinforcing agent may be insufficient, and the mechanical properties of the rubber molded product may deteriorate. On the other hand, if the proportion of the filler exceeds the above range, the viscosity may be too high and molding may be difficult.
(D component)
Examples of the organic peroxide crosslinking agent (component D) include benzoyl peroxide, 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (Benzoylperoxy) hexane, di (tert-butylperoxy) diisopropylbenzene, 1,4-bis [(tert-butyl) peroxyisopropyl] benzene, di (tert-butylperoxy) benzoate, tert-butylperoxy Benzoate, dicumyl peroxide, tert-butyl cumyl peroxide, 2,5-dimethyl-2,5-di (tert-butylperoxy) hexane, ditert-butyl peroxide, 2,5-dimethyl-2,5 -Di (tert-butylperoxy) -3-hexene and the like can be mentioned. .

The composition of the present invention may use one kind or two or more kinds of the above organic peroxide crosslinking agents. The organic peroxide crosslinking agent (D component) is preferably 0 relative to 100 parts by weight in total of the ethylene-alkyl acrylate copolymer (A component) and the ethylene / α-olefin / diene copolymer (B component). 2 to 50 parts by weight, more preferably 0.5 to 30 parts by weight, still more preferably 1 to 20 parts by weight. If the proportion of the organic peroxide cross-linking agent is less than this range, the cross-linking will be insufficient, and it may not be possible to form a good rubber molded product having appropriate mechanical properties. On the other hand, if the proportion of the organic peroxide crosslinking agent exceeds the above range, scorch may occur during processing or molding.
(Other additives)
The composition of the present invention is a conventionally known compounding agent other than organic peroxide, which is a conventionally known compounding agent, depending on the properties required for a crosslinked rubber product (tensile strength, tensile elongation, abrasion resistance, conductivity, etc.). Cross-linking agents, cross-linking accelerators, co-cross-linking agents, organic foaming agents, processing aids, fillers, plasticizers, anti-aging agents, lubricants, flame retardants, stabilizers, anti-static agents, anti-bacterial and anti-mold agents, sliding You may contain a property improving agent, a coloring agent, etc.

  As the co-crosslinking agent for the organic peroxide cross-linking agent, a co-crosslinking agent composed of a polyfunctional unsaturated compound, a maleimide compound, and a quinone compound is preferably used in combination. Examples of the polyfunctional unsaturated compound, for example, ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, triallyl (iso) cyanurate, trimethylolpropane tri (meth) acrylate, triallyl trimellitate, and the like, Examples of the maleimide compound include N, N'-m-phenylene bismaleimide, toluylene bismaleimide, and the like. Examples of the quinone compound include quinone dioxime and dibenzoyl-p-quinone dioxime.

  Examples of the crosslinking accelerator include N-cyclohexyl-2-benzothiazolyl sulfenamide, N-tert-butyl-2-benzothiazolyl sulfenamide, N-oxyethylene-2-benzothiazolyl sulfenamide, N -Sulfenamide compounds such as oxyethylene-2-benzothiazolyl sulfenamide and N, N'-diisopropyl-2-benzothiazolyl sulfenamide; sodium dimethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate , Dibutyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc N-pentamethylenedithiocarbamate, zinc dibenzyldithiocarbamate and the like; tetramethylthiuram monosulfide, te Laethylthiuram monosulfide, tetraisopropylthiuram monosulfide, tetrabutylthiuram monosulfide, tetrabenzylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetraisopropylthiuram disulfide, tetrabutylthiuram disulfide, tetrabenzylthiuram disulfide, tetrakis ( 2-ethylhexyl) thiuram-based compounds such as thiuram disulfide; 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, 2- (4'-morpholinodithio) benzothiazole, zinc salt of 2-mercaptobenzothiazole, 2 -Thiazole compounds such as cyclohexylamine salt of mercaptobenzothiazole; 1,3-diphenylguanidine Guanidine compounds such as 1,3-di-o-tolylguanidine and 1-o-tolylbiguanide; thiourea compounds such as diethylthiourea; xanthate acid compounds such as sodium isopropylxanthate, zinc isopropylxanthate, zinc butylxanthate and the like. Compounds: Metal methacrylic acid salts such as magnesium dimethacrylate and zinc dimethacrylate, etc. may be mentioned.

  In the composition of the present invention, one kind or two or more kinds of the above crosslinking accelerators can be used.

Examples of the processing aids include zinc oxide: higher fatty acids such as ricinoleic acid, stearic acid, palmitic acid, and lauric acid; salts of higher fatty acids such as barium stearate, zinc stearate, calcium stearate; ricinoleic acid, stearic acid, and palmitine Examples thereof include esters of higher fatty acids such as acid and lauric acid.
The composition of the present invention may use one or more of the above processing aids.

Examples of the plasticizer include petroleum-based plasticizers such as process oil, lubricating oil, paraffin and vaseline; fatty oil-based plasticizers such as castor oil, linseed oil, rapeseed oil and coconut oil; tall oil; sub; beeswax and carnauba wax. , Waxes such as lanolin; fatty acids or fatty acid salts such as ricinoleic acid, palmitic acid, barium stearate, calcium stearate, zinc laurate; synthetic polymers such as petroleum resin, atactic polypropylene, coumarone indene resin, etc. .. With respect to a total of 100 parts by weight of the ethylene-alkyl acrylate copolymer (component A) and the ethylene / α-olefin / diene copolymer (component B), preferably 0 to 100 parts by mass, more preferably 0 to 80 parts by mass. Parts, and more preferably 0 to 50 parts by mass.
In the composition of the present invention, one kind or two or more kinds of the above plasticizers can be used.

Examples of the antioxidant include naphthylamine compounds, diphenylamine compounds, p-phenyldiamine compounds, quinoline compounds, hydroquinone derivatives, monophenol compounds, thiobisphenol compounds, hindered phenol compounds, phosphite compounds. A compound etc. are mentioned.
The composition of the present invention can use one or two or more of the above heat anti-aging agents.

Examples of the lubricant include paraffin wax, liquid paraffin, paraffin synthetic wax, polyethylene wax, zinc stearate, hydroxystearic acid, fatty acid amide, fatty acid ester, silicone gel, silicone oil, silicone powder, silicone-containing polymer, silicone graft. Examples thereof include polymers.
The rubber composition of the present invention can use one kind or two or more kinds of the above lubricants.
(Method for producing composition)
The composition of the present invention can be produced by mixing each component according to a conventional method.

  A preferred production method is a step of kneading a compounding agent excluding a crosslinking agent and a crosslinking accelerator, and rubber (first kneading step), the obtained kneaded material (hereinafter, referred to as “first kneaded material”), and cross-linking. In this method, the step of mixing the agent, the crosslinking accelerator, and the other compounding agent (mixing step) are sequentially performed.

  In the first kneading step, for example, a closed kneader such as a Banbury mixer, an intermixer, or a kneader can be used. The obtained first kneaded product is the composition of the present invention before the addition of the crosslinking agent and the like. The kneading temperature is 50 ° C or higher, more preferably 60 ° C or higher, and further preferably 70 ° C or higher. Further, it is 200 ° C. or lower, more preferably 180 ° C. or lower, still more preferably 170 ° C. or lower.

In the mixing step, the first kneaded product is blended with a crosslinking agent and a crosslinking accelerator, and the mixture is kneaded using an open roll or the like at 100 ° C. or lower, more preferably 90 ° C. or lower, further preferably 80 ° C. or lower. Preferably. The mixing time in the mixing step is usually 30 seconds to 10 minutes.
(Method for producing crosslinked composition)
The cross-linking composition can be formed by subjecting the composition containing the cross-linking agent to a conventionally known heating method or molding method such as press heating, steam heating, oven heating, and hot air heating. The method for producing the cross-linked composition is not particularly limited, and an injection molding machine, an extrusion molding machine and a non-pressurized heating device such as a vulcanization tank or a hot air oven, a vulcanization can, a compression molding machine, a transfer molding machine, etc. are used. It can be the way you were. The heating is preferably performed at 220 ° C. or lower, more preferably 210 ° C. or lower, and further preferably 190 ° C. or lower.
(Example)
Hereinafter, the present invention will be specifically described based on Examples, but the present invention is not limited to these Examples. "Parts" and "%" in Examples and Comparative Examples are based on mass unless otherwise specified.

Example 1
A kneaded material was prepared by mixing the components except the peroxide, the co-crosslinking agent, and the crosslinking agent in the types and amounts shown in Table 1 and kneading at 100 ° C. using a 600 cc plastomill (manufactured by Toyo Seiki Co., Ltd.). .. Then, the kind and amount of peroxide, co-crosslinking agent, and crosslinking agent shown in Table 1 were added to the kneaded product, and the mixture was kneaded with an open roll to prepare a composition.

At this time, the roll processability was evaluated by visually observing during kneading with an open roll.
When there was no strong adhesion to the roll, it was judged as good, and when strong adhesion was strong, it was judged as bad. The results are shown in Table 1.

  The obtained composition was compression molded at 180 ° C. for 15 minutes to obtain a sheet-shaped molded product having a thickness of 2 mm. Tensile strength, tensile elongation and Duro A hardness according to JIS K6253, 6251 were measured as the normal physical properties of the produced sheet-shaped molded product. As the properties of the produced sheet-shaped molded product after the heat resistance test, the tensile strength, the tensile elongation, and the Duro A hardness after the test at 150 ° C. for 70 hours were measured according to JIS K6257.

  Regarding normal state physical properties and tensile strength after heat resistance test, 10 MPa or more was judged as good and less than 10 MPa was judged as poor.

Based on the measurement results of normal physical properties and the measurement results after the heat resistance test, the rate of change in tensile strength, the rate of change in tensile elongation, and the rate of change in hardness were calculated according to the following formulas and evaluated as heat resistance.
Tensile strength change rate (%)
= (Tensile strength after heat resistance test-Tensile strength of normal physical properties) / Tensile strength of normal physical properties x 100
Tensile elongation change rate (%)
= (Tensile elongation after heat resistance-Tensile elongation of normal physical properties) / Tensile elongation of normal physical properties x 100
Hardness change rate (%) = Duro A hardness after heat resistance test-Duro A hardness of normal physical properties Change rate of tensile strength is within ± 30%, change rate of tensile elongation is within ± 50%, hardness change is within ± 7 The case of satisfying all was judged to be good, and the case of not satisfying all was judged to be bad. The results are shown in Table 1.

In addition, the oil resistance of the produced sheet-shaped molded product was 100 according to JIS K6258, using an oil resistance evaluation device (Toyo Seiki Seisakusho Co., Ltd., test tube aging tester) and Nippon San Oil Co., Ltd. IRM903 (product number). The volume change rate ΔV ₁₀₀ after 72 hours at ℃ was measured. A change rate of less than 120% was judged to be good, and a change rate of 120 or more was judged to be bad.

Examples 2-6, Comparative Examples 1-15
A composition was prepared and evaluated in the same manner as in Example 1 except that each component was changed to the type and amount shown in Table 1. The evaluation results are also shown in Table 1.

  In addition, the content of each component in 1 shows a mass part.

Further, the abbreviations of the components in Table 1 mean the following compounds, respectively.
A-1: VAMAC VMX2122 (trade name) manufactured by DuPont, having a peroxide crosslinking property, and Mooney viscosity ML _{1 + 4} (100 ° C.) 22
A-2: VAMAC G (trade name) manufactured by DuPont, having no peroxide cross-linking property, Mooney viscosity ML _{1 + 4} (100 ° C.) 16.5
B-1: manufactured by JSR, EP43, ethylene / propylene / diene copolymer, 1.5 parts by mass of repeating unit derived from diene, 6 parts by mass of repeating unit derived from ethylene, Mooney viscosity ML _{1 + 4} (100 ° C.) 47
B-2: manufactured by JSR, EP96, ethylene / propylene / diene copolymer, 5.8 parts by mass of repeating unit derived from diene, 66 parts by mass of repeating unit derived from ethylene, 50 phr of extender oil, Mooney viscosity ML _{1 + 4} ( 100 ° C) 77
B-3: manufactured by JSR, EP331, ethylene / propylene / diene copolymer, 11.3 parts by mass of repeating unit derived from diene, 47 parts by mass of repeating unit derived from ethylene, Mooney viscosity ML _{1 + 4} (100 ° C.) 28
B-4: manufactured by JSR, EP98, ethylene / propylene / diene copolymer, 4.5 parts by mass of repeating unit derived from diene, 66 parts by mass of repeating unit derived from ethylene, extending oil 60 phr, Mooney viscosity ML _{1 + 4} ( 100 ° C) 90
C-1: Tokai Carbon Co., Seast SO (trade name)
Organic peroxide: NOF Corporation, Perbutyl P-40 (trade name)
Anti-aging agent: Nocrac CD (trade name) manufactured by Ouchi Shinko Chemical Co., Ltd.
Processing aid 1: manufactured by Miyoshi Yushi Co., stearic acid, TST (trade name)
Processing aid 2: Dainippon Ink and Chemicals, Inc., GREC G-8205 (trade name)
Co-crosslinking agent: Barnock PM-P (trade name) manufactured by Ouchi Shinko Chemical Industry Co., Ltd.
Crosslinking agent: Duak No. manufactured by DuPont Elastomer Co., Ltd. 1 (Product name)
5.11. Results Examples 1 to 6 relating to the composition of the present invention have good normal state physical properties, heat resistance, oil resistance and roll processability. On the other hand, Comparative Examples 1 to 7, which were not the present invention, were defective.

  The present invention is not limited to the above embodiment, but various modifications can be made. The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations having the same function, method, and result, or configurations having the same purpose and effect). Further, the invention includes a configuration in which the non-essential part of the configuration described in the above embodiment is replaced with another configuration. Furthermore, the present invention also includes a configuration that achieves the same effect as the configuration described in the above embodiment or a configuration that can achieve the same object. Furthermore, the present invention also includes a configuration in which a known technique is added to the configurations described in the above embodiments.

Claims (5)

An ethylene-alkyl acrylate copolymer (component A) having a peroxide-crosslinkable functional group,
An ethylene / α-olefin / diene copolymer (component B),
A filler (C component),
Containing
Content of component A (parts by mass) / content of component B (parts by mass) = 10/90 to 70/30,
A composition in which the content of the C component is 10 to 500 parts by mass with respect to a total of 100 parts by mass of the content of the A component and the content of the B component.   The composition according to claim 1, further comprising 0.2 to 50 parts by weight of an organic peroxide crosslinking agent (D component) with respect to a total of 100 parts by weight of the content of the A component and the content of the B component. In 100 parts by mass of the component B,
The content of the repeating unit derived from a diene is 1 to 15 parts by weight,
The content of repeating units derived from ethylene is 45 to 70 parts by weight,
The Mooney viscosity ML _{1 + 4} (100 ° C.) of the component A is 25 to 100,
The ratio of the Mooney viscosity of the B component (ML _{1 + 4} (100 ° C.)-1) and the Mooney viscosity of the A component (ML _{1 + 4} (100 ° C.)-2) is
(ML _{1 + 4} (100 ° C.) −2) / (ML _{1 + 4} (100 ° C.) − 1) = 1.2 or more,
The composition according to claim 1 or 2.   The composition according to any one of claims 1 to 3, wherein the component B is an ethylene / propylene / diene copolymer. The composition according to any one of claims 1 to 4, wherein the component A has a repeating unit derived from methyl acrylate.