JP2001123030A - Rubber composition for automobile waterhose and building material gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automobile waterhose having a small cold-temperature flexibility and high-temperature compression set and a building material gasket having a silicone sealant stain resistance and a small cold-temperature flexibility and high-temperature compression set without deteriorating the heat resistance nor the weather resistance. SOLUTION: A rubber composition for automobile waterhose comprises a random copolymer rubber (A) comprising structural units derived from ethylene, a 3-20C α-olefin and a specific triene compound, a vulcanizing agent (B) and a filler (C).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automotive water hose and a rubber composition for a building material gasket, and more particularly, to a vulcanization rate capable of high-speed molding of an automotive water hose excellent in low-temperature flexibility and small in high-temperature compression set. Fast rubber composition for automotive water hose, and silicone sealant stain resistance, blooming resistance,
The present invention relates to a rubber composition for a building material gasket having a high vulcanization rate, which is excellent in low-temperature flexibility and capable of high-speed molding of a building material gasket having a small high temperature compression set.

[0002]

BACKGROUND OF THE INVENTION Ethylene / propylene / non-conjugated diene copolymer rubber (hereinafter sometimes referred to as EPT)
Because of its excellent weather resistance, ozone resistance and heat aging resistance, it is often used in water hoses such as radiator hoses and heater hoses of automobiles. However, since EPT has a slow vulcanization rate, a vulcanization accelerator and a vulcanization aid are added to a rubber composition used for an automobile water hose in order to increase the vulcanization rate. Two or more vulcanization accelerators and vulcanization aids are used in combination. As described above, the vulcanization process of the conventional rubber composition for automotive water hoses is complicated because various types of vulcanization accelerators and the like are used. Even if such a complicated vulcanization process is employed, there is a limit to increasing the vulcanization rate, and the productivity of automotive water hoses has not been sufficiently improved. Further, the conventional rubber composition for automotive water hoses has a problem in that it requires a combination of various kinds of vulcanization accelerators, which hinders the rationalization of the measuring step and the like.

[0003] In addition, automotive water hoses are required to be excellent in low-temperature flexibility and small in high-temperature compression set since they are exposed to cold and high temperatures and are loaded. However, although the conventional EPT compositions have good low-temperature flexibility, they are not yet sufficient and have room for improvement. Further, the conventional EPT composition has a small high-temperature compression set, but there is a demand from the automobile industry to further reduce the high-temperature compression set, and there is room for improvement.

[0004] By the way, since EPT is excellent in weather resistance, ozone resistance and heat aging resistance, it is often used for building material gaskets. However, building material gaskets are often used in combination with a silicone sealant, and contamination of the silicone sealant may be a problem. This silicone sealant contamination is EPT
It is affected by the type of vulcanization accelerator and process oil contained in the composition.

According to tests by silicone rubber manufacturers, vulcanization accelerators which do not contaminate the silicone sealant include MBTS (dibenzothiazyl disulfide),
ZnBDC (zinc dibutyldithiocarbamate), Zn
EDC (Zinc diethyldithiocarbamate), ZnEP
DC (zinc N-ethyl-N-phenyldithiocarbamate), CBS (N-cyclohexyl-2-benzothiazolylsulfenamide) and CMBT (cyclohexylamine salt of 2-mercaptobenzothiazole). It is said that MBT (2-mercaptobenzothiazole) and EU (2-mercaptoimidazoline) can be used if present.

[0006] However, these vulcanization accelerators have a problem that the vulcanization rate is low or blooming is easy. Therefore, the conventional rubber composition for a building material gasket containing EPT as a main component has a problem that the vulcanization rate is low due to the use of the vulcanization accelerator as described above, and the productivity of the building material gasket is poor. Further, the EPT composition having a high vulcanization rate and good productivity has a problem of silicone sealant contamination.

[0007] As a process oil, a paraffin-based process oil having a medium and high viscosity is said to be good against silicone sealant contamination. Further, since a gasket for building materials is exposed to cold and high temperatures and is subjected to a load, it is required to have excellent low-temperature flexibility and small high-temperature compression set. However, conventional EP
Although T compositions have good low temperature flexibility, they are still inadequate and have room for improvement. Further, the conventional EPT composition has a small high-temperature compression set, but there is room for improvement to further reduce the high-temperature compression set.

[0008] The present inventors have developed an automotive water hose composition which is excellent in low-temperature flexibility and has a small high-temperature compression set, or has excellent silicone sealant stain resistance, blooming resistance and low-temperature flexibility. Intensive research has been conducted to obtain a building material gasket composition having a smaller compression set at high temperature, and identification of 4,8-dimethyl-1,4,8-decatriene (DMDT) or the like as a structural unit derived from a triene compound constituting EPT. If you select the compound of
It has been found that a composition suitable for the above purpose can be obtained, and this composition can be molded at a high speed and has a high vulcanization rate.

As a rubber composition for automobile water hoses and building material gaskets, JP-A-10-139950
Discloses an ethylene / propylene / 4-ethylidene-8-methyl-1,7-nonadiene copolymer rubber (E) produced using a specific Group IVB transition metal catalyst.
MND-EPT), a vulcanizing agent, and a filler have been proposed, but the ethylene propylene 4,8-dimethyl-1,4,8-decatriene ( By using DMDT-EPT), the scorch stability is further improved while the vulcanization rate is equal.

[0010]

SUMMARY OF THE INVENTION The object of the present invention is to solve the problems associated with the prior art as described above, and to reduce the low temperature without deteriorating the excellent heat aging and weather resistance inherent of EPT. It is an object of the present invention to provide a rubber composition for an automotive water hose having a high vulcanization rate, which is excellent in flexibility and capable of high-speed molding of an automotive water hose having a small high-temperature compression set.

Further, the present invention provides a rubber for building material gaskets having a high vulcanization rate, which is excellent in silicone sealant stain resistance, blooming resistance and low-temperature flexibility, and is capable of high-speed molding of building material gaskets having a small high-temperature compression set. It is intended to provide a composition.

[0012]

SUMMARY OF THE INVENTION The rubber composition for automotive water hoses according to the present invention comprises ethylene and α-C 3 -C 20.
It comprises a random copolymer rubber (A) comprising an olefin, a structural unit derived from a triene compound represented by the following general formula [1], a vulcanizing agent (B), and a filler (C). And the random copolymer rubber (A) comprises (i)
The molar ratio of ethylene to α-olefin having 3 to 20 carbon atoms (ethylene / α-olefin) is 99/1 to 30 /
70, (ii) the content of the structural unit derived from the triene compound is 0.1 to 30 mol%, and (ii)
i) The intrinsic viscosity [η] measured in decalin at 135 ° C. is in the range of 0.1 to 10 dl / g.

[0013]

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[In the formula [1], R ¹ and R ² are each independently a hydrogen atom, a methyl group or an ethyl group, and R ³ and R ⁴ are each independently a methyl group or an ethyl group. Further, the rubber composition for a building material gasket according to the present invention is a random composition comprising ethylene, an α-olefin having 3 to 20 carbon atoms, and a structural unit derived from the triene compound represented by the general formula [1]. Copolymer rubber (A)
And a vulcanizing agent (B) and a filler (C). The random copolymer rubber (A) comprises (i) a mole of ethylene and an α-olefin having 3 to 20 carbon atoms. The ratio (ethylene / α-olefin) is in the range of 99/1 to 30/70, (ii) the content of the structural unit derived from the triene compound is 0.1 to 30 mol%, and (iii) 13
Intrinsic viscosity [η] measured in decalin at 5 ° C is 0.1 to 1
It is characterized by being in the range of 0 dl / g.

[0015]

DETAILED DESCRIPTION OF THE INVENTION The rubber composition for automotive water hoses and the rubber composition for building material gaskets according to the present invention will be specifically described below.

The rubber composition for automobile water hoses and the rubber composition for gaskets for building materials according to the present invention contain a specific random copolymer rubber (A), a vulcanizing agent (B) and a filler (C). Do it.

Random Copolymer Rubber (A) The random copolymer rubber (A) used in the present invention comprises ethylene, an α-olefin having 3 to 20 carbon atoms, and a structural unit derived from a triene compound. Become.

Examples of the α-olefin having 3 to 20 carbon atoms include propylene, 1-butene,
1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-
Pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 1-octene, 1-decene,
Examples thereof include 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, and 1-eicosene. Among them, propylene, 1-butene, 1-hexene and 1-octene are preferably used.

These α-olefins can be used alone or in combination of two or more. The structural unit derived from the triene compound is represented by the following general formula [1].

[0020]

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[In the formula [1], R ¹ and R ² are each independently a hydrogen atom, a methyl group or an ethyl group, and R ³ and R ⁴ are each independently a methyl group or an ethyl group. ]

Among the triene compounds represented by the above formula [1], a compound in which R ³ and R ⁴ are both methyl groups is preferable, and a random copolymer rubber obtained by using such a triene compound as a monomer material is It is particularly excellent in the balance between vulcanization rate and scorch characteristics.

Specific examples of the triene compound represented by the formula [1] include the following compounds.

Embedded image These compounds can be produced by the method described in Japanese Patent Application No. 11-146429.

Among the above triene compounds, 4,8-dimethyl-1,4,8-decatriene (hereinafter abbreviated as DMDT), which is the first exemplified, is preferable. The triene compound represented by the formula [1] may be a mixture of a trans form and a cis form, or may be a trans form alone or a cis form alone.

The triene compound represented by the formula [1] is obtained by reacting a compound having a conjugated diene represented by the following formula [2] with ethylene in the presence of a catalyst comprising a transition metal compound and an organoaluminum compound. Can be manufactured.

[0026]

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[0027] (wherein ^{[2], R 1, R} 2, R 1 in R ³ and R ⁴ in general formula described above, respectively ^{[1], R 2, R} 3
And R ⁴ are the same. In the random copolymer rubber (A) used in the present invention, the structural units derived from the monomers of the ethylene, α-olefin and triene compounds as described above are randomly arranged and bonded to form a triene rubber. It has a branched structure due to the compound, and the main chain has a substantially linear structure.

The fact that the copolymer rubber has a substantially linear structure and substantially does not contain a gel-like crosslinked polymer means that the copolymer rubber is dissolved in an organic solvent and the insoluble content is substantially reduced. It can be confirmed by not including it. For example, when the intrinsic viscosity [η] is measured, it can be confirmed that the copolymer rubber is completely dissolved in decalin at 135 ° C.

In such a random copolymer rubber (A), the structural unit derived from the triene compound has a structure substantially represented by the following formula [3].

[0030]

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[0031] (wherein ^{[2], R 1, R} 2, R 1 in R ³ and R ⁴ in general formula described above, respectively ^{[1], R 2, R} 3
And R ⁴ are the same. The fact that the structural unit derived from the triene compound has the above structure can be confirmed by measuring the ¹³ C-NMR spectrum of the copolymer.

The random copolymer rubber (A) used in the present invention has the following composition and properties. (I) The random copolymer rubber (A) used in the rubber composition for automotive water hoses has a molar ratio of ethylene to an α-olefin having 3 to 20 carbon atoms (ethylene / α
-Olefin) from 99/1 to 30/70, preferably 8
0/20 to 50/50, particularly preferably 80/20 to 6
It is in the range of 0/40. Ethylene and 3-20 carbon atoms
When the random copolymer rubber (A) having a molar ratio (ethylene / α-olefin) to the above α-olefin in the above range is used, an automobile water hose excellent in low-temperature flexibility can be provided. A rubber composition is obtained.

The random copolymer rubber (A) used in the rubber composition for building material gaskets has a molar ratio of ethylene to α-olefin having 3 to 20 carbon atoms (ethylene / α-olefin) of 99 /. 1/30/70, preferably 80/20 to 50/50, particularly preferably 80/20
６０60/40. Ethylene and carbon number 3 ~
When a random copolymer rubber (A) having a molar ratio (ethylene / α-olefin) of 20 to an α-olefin in the above range is used, a building material gasket excellent in low-temperature flexibility can be provided. A rubber composition is obtained.

(Ii) The random copolymer rubber (A) used in the rubber composition for automobile water hoses and the rubber composition for building material gaskets has a content of structural units derived from a triene compound of 0.1 to 30 mol. %, Preferably in the range of 0.5 to 10 mol%, especially 0.5 to 5 mol%. When a random copolymer rubber (A) having a content of a structural unit derived from a triene compound in the above range is used, an automobile water hose and a building material gasket having a small high-temperature compression set can be provided. A rubber composition having a high sulfuration rate can be obtained.

(Iii) The random copolymer rubber (A) used in the rubber composition for automobile water hoses and the rubber composition for building material gaskets has an intrinsic viscosity [η] of 0.1 to 0.10 measured in decalin at 135 ° C. It is in the range of 10 dl / g, preferably 2-6, particularly preferably 2-4. In these applications, the amount of the filler (C) is often large, but when the random copolymer rubber (A) having the intrinsic viscosity [η] in the above range is used, the tensile strength is high. In addition, a rubber composition capable of providing an automotive water hose and a building material gasket having a small high-temperature compression set can be obtained.

The above random copolymer rubber (A)
Can be obtained by copolymerizing ethylene, an α-olefin having 3 to 20 carbon atoms, and a structural unit derived from the triene compound represented by the general formula [1] in the presence of a catalyst.

As such a catalyst, a Ziegler catalyst comprising a transition metal compound such as vanadium (V), zirconium (Zr) or titanium (Ti) and an organic aluminum compound (organic aluminum oxy compound) can be used.

In the present invention, [a] a catalyst comprising a soluble vanadium compound and an organoaluminum compound, or [b] a metallocene compound of a transition metal selected from Group IVB of the periodic table, and an organoaluminum oxy compound or an ionized ionic compound A catalyst comprising a compound is particularly preferably used.

In the present invention, the catalyst [a] (a catalyst comprising a soluble vanadium compound and an organoaluminum compound) or the catalyst [b] (a metallocene compound of a transition metal selected from Group IV of the periodic table) and an organic Ethylene in the presence of an aluminum oxy compound or a catalyst comprising an ionized ionic compound) and ethylene having an α of 3 to 20 carbon atoms.
-An olefin and a structural unit derived from a triene compound are usually copolymerized in a liquid phase.

In this case, a hydrocarbon solvent is generally used, but an α-olefin such as propylene may be used as the solvent. Specific examples of such hydrocarbon solvents include pentane, hexane, heptane, octane, decane, dodecane, aliphatic hydrocarbons such as kerosene and halogen derivatives thereof, cyclohexane, methylcyclopentane,
Alicyclic hydrocarbons such as methylcyclohexane and halogen derivatives thereof, aromatic hydrocarbons such as benzene, toluene and xylene, and halogen derivatives such as chlorobenzene are used.

These solvents may be used in combination.
The copolymerization of ethylene, an α-olefin having 3 to 20 carbon atoms and a structural unit derived from a triene compound may be carried out by either a batch method or a continuous method. When the copolymerization is carried out by a continuous method, the above-mentioned catalyst is used in the following concentration.

In the present invention, when the above-mentioned catalyst [a], that is, a catalyst comprising a soluble vanadium compound and an organoaluminum compound, is used, the concentration of the soluble vanadium compound in the polymerization system is usually 0.01 to 5%. Mmol / liter (polymerization volume), preferably 0.05 to 3 mmol / liter. This soluble vanadium compound is desirably supplied at a concentration of 10 times or less, preferably 1 to 7 times, more preferably 1 to 5 times the concentration of the soluble vanadium compound present in the polymerization system.

The organoaluminum compound has a ratio of aluminum atoms to vanadium atoms in the polymerization system (A
1 / V), and is supplied in an amount of 2 or more, preferably 2 to 50, more preferably 3 to 20.

The catalyst [a] comprising a soluble vanadium compound and an organoaluminum compound is usually diluted with the above-mentioned hydrocarbon solvent and / or a liquid α-olefin having 3 to 20 carbon atoms and a branched polyene compound. Supplied. At this time, the soluble vanadium compound is desirably diluted to the concentration described above, and the organoaluminum compound is diluted to, for example, 50% of the concentration in the polymerization system.
It is desirable to adjust the concentration to an arbitrary concentration of 2 times or less and supply it to the polymerization system.

In the present invention, when a catalyst [b] comprising a metallocene compound and an organic aluminum oxy compound or an ionized ionic compound (also referred to as an ionic ionized compound or an ionic compound) is used, a polymerization system is used. The concentration of the metallocene compound in is usually 0.1.
0.0005-0.1 mmol / liter (polymerization volume),
Preferably it is 0.0001-0.05 mmol / l.

The organic aluminum oxy compound is
It is supplied in an amount of 1 to 10,000, preferably 10 to 5,000 in terms of the ratio of aluminum atoms to the metallocene compound in the polymerization system (Al / transition metal).

In the case of the ionized ionic compound, the molar ratio of the ionized ionic compound to the metallocene compound in the polymerization system (ionized ionic compound / metallocene compound) is 0.5 to 20, preferably 1 to 10. Supplied.

When an organoaluminum compound is used, it is generally used in an amount of about 0 to 5 mmol / l (polymerization degree), preferably about 0 to 2 mmol / l.

In the present invention, ethylene, an α-olefin having 3 to 20 carbon atoms and a structural unit derived from a triene compound are copolymerized in the presence of a catalyst [a] comprising a soluble vanadium compound and an organoaluminum compound. When it is carried out, the copolymerization reaction is usually carried out at a temperature of -50C to 10C.
The reaction is carried out at 0 ° C., preferably at −30 ° C. to 80 ° C., more preferably at −20 ° C. to 60 ° C., and at a pressure of 5 MPa or less, preferably 2 MPa or less. However, the pressure is not zero.

In the present invention, ethylene, an α-olefin having 3 to 20 carbon atoms and a triene compound are derived in the presence of a catalyst [b] comprising a metallocene compound and an organic aluminum oxy compound or an ionized ionic compound. When copolymerizing with a structural unit, the temperature of the copolymerization reaction is usually from -20 ° C to 150 ° C, preferably 0 ° C.
C. to 120.degree. C., more preferably 0.degree. C. to 100.degree. C., and a pressure of 8 MPa or less, preferably 5 MPa or less.

The reaction time (average residence time when the copolymerization is carried out by a continuous method) varies depending on conditions such as the catalyst concentration and the polymerization temperature, but is usually 5 minutes to 5 hours, preferably 10 minutes. ~ 3 hours.

In the present invention, ethylene, C 3 -C 2
The structural unit derived from the α-olefin and the triene compound of 0 is supplied to the polymerization system in such an amount as to obtain the random copolymer rubber having the above specific composition. Further, upon copolymerization, a molecular weight regulator such as hydrogen may be used.

As described above, ethylene and carbon atoms 3
When structural units derived from α-olefins and triene compounds of from 20 to 20 are copolymerized, a random copolymer rubber is usually obtained as a polymerization liquid containing the same. This polymerization liquid is
It is processed by a conventional method to obtain a random copolymer rubber.

The method for preparing the random copolymer rubber (A) [unsaturated ethylenic copolymer] as described above is described in detail in the specification of Japanese Patent Application No. 7-69986 filed by the present applicant. Have been.

Vulcanizing Agent (B) Examples of the vulcanizing agent (B) used in the present invention include sulfur, sulfur compounds, and organic peroxides.

Specific examples of the sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur, and insoluble sulfur. As sulfur compounds,
Specific examples include sulfur chloride, sulfur dichloride, polymer polysulfide, and the like. Sulfur compounds that release active sulfur at the vulcanization temperature and vulcanize, such as morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide, and the like can also be used.

In the present invention, the sulfur or the sulfur compound is used in a proportion of 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the random copolymer rubber (A). Can be

When sulfur or a sulfur compound is used as the vulcanizing agent (B), it is preferable to use a vulcanization accelerator in combination. Specific examples of the vulcanization accelerator include N-cyclohexyl-2-benzothiazolesulfenamide (CBS), N-oxydiethylene-2-benzothiazolesulfenamide, N, N-diisopropyl-2-benzothiazole Sulfenamide, 2-mercaptobenzothiazole (MBT), 2- (2,4-dinitrophenyl) mercaptobenzothiazole, 2- (2,6-diethyl-4-morpholinothio) benzothiazole, dibenzothiazyl disulfide (MBTS ); Guanidine compounds such as diphenylguanidine, triphenylguanidine, diorsonitrile guanidine, orthonitrile biguanide, diphenylguanidine phthalate; acetaldehyde-aniline reactant, butyraldehyde-aniline condensate, hexamethylenetetramine, Aceto Aldehydeamine or aldehyde-ammonia compounds such as aldehyde ammonia; imidazoline compounds such as 2-mercaptoimidazoline (EU); Thiuram-based compounds such as tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, pentamethylenethiuram tetrasulfide; zinc dimethyldithiocarbamate (ZnMDC), zinc diethyldithiocarbamate (Z
nEDC), zinc di-n-butyldithiocarbamate (Z
nBDC), zinc ethylphenyldithiocarbamate (ZnEPDC), zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate (NaM
DC), dithioacid salt compounds such as selenium dimethyldithiocarbamate and tellurium dimethyldithiocarbamate;
Xanthate compounds such as zinc dibutylxanthogenate; and compounds such as zinc white.

In the present invention, among the rubber compositions for building material gaskets, vulcanization accelerators with low silicone sealant contamination, such as MBTS and ZnBD, are used for glazing gaskets requiring silicone sealant contamination resistance.
C, ZnEDC, CBS, CMBT (cyclohexylamine salt of 2-mercaptobenzothiazole) is preferred,
If the amount is small, MBT and EU can be used.

In the present invention, the vulcanization accelerator is used in an amount of 0.1 to 100 parts by weight of the random copolymer rubber (A).
It is used in a proportion of 20 parts by weight, preferably 0.2 to 10 parts by weight.

The organic peroxide may be any compound usually used for peroxide vulcanization of rubber. For example, dicumyl peroxide, di-t-butyl peroxide,
Di-t-butylperoxy-3,3,5-trimethylcyclohexane, t-butyl hydroperoxide, t-butylcumyl peroxide, benzoyl peroxide, 2,5-dimethyl-2,5-di (t-butyl Peroxin) hexyne-3,2,
5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2,5-mono (t-butylperoxy)-
Hexane, α, α′-bis (t-butylperoxy-m-isopropyl) benzene and the like can be mentioned. Among them, dicumyl peroxide, di-t-butyl peroxide,
Di-t-butylperoxy-3,3,5-trimethylcyclohexane is preferably used. These organic peroxides
One type or a combination of two or more types is used.

In the present invention, the organic peroxide is added in an amount of 0.1 to 100 parts by weight of the random copolymer rubber (A).
Although it is used in a proportion of 10 to 10 parts by weight, it is desirable to appropriately determine an optimum amount according to required physical properties.

When an organic peroxide is used as the vulcanizing agent (B), it is preferable to use a vulcanizing aid in combination. Specific examples of the vulcanization aid include sulfur; quinone dioxime compounds such as p-quinone dioxime; methacrylate compounds such as polyethylene glycol dimethacrylate; allyl compounds such as diallyl phthalate and triallyl cyanurate; Other maleimide compounds include divinylbenzene.

In the present invention, it is preferable to use sulfur or a sulfur compound as the vulcanizing agent (B), and it is desirable to use a vulcanization accelerator in combination. Filler (C) The filler (C) used in the present invention includes a filler having a reinforcing property and a filler having no reinforcing property.

The filler having a reinforcing property has an effect of improving mechanical properties such as tensile strength, tear strength and abrasion resistance of the vulcanized rubber. As such a filler, specifically,
Examples thereof include carbon black, silica, activated calcium carbonate, and fine talc, which may be subjected to a surface treatment with a silane coupling agent. In the present invention, any type of carbon black that is commonly used for rubber can be used regardless of its type.

The filler having no reinforcing property can increase the hardness of the rubber product without significantly affecting the physical properties,
Used to reduce costs. As such a filler, specifically, talc, clay,
Calcium carbonate and the like.

Among the rubber compositions for building material gaskets, for glazing gaskets that require silicone sealant contamination resistance, fillers such as carbon black with low silicone sealant contamination are used.

In the present invention, the filler (C) is used in an amount of 20 to 100 parts by weight of the random copolymer rubber (A).
It is used in a proportion of 200 parts by weight, preferably 50 to 150 parts by weight.

In the rubber composition for an automotive water hose according to the present invention, in addition to the above random copolymer rubber (A), vulcanizing agent (B) and filler (C), Accelerators and vulcanization aids can be compounded, but in addition, softeners, processing aids, ethylene glycol-based activators, organic amine-based activators, heat aging inhibitors, UV absorbers and other rubber compounds Agents can be added within a range that does not impair the purpose of the present invention.

In the rubber composition for building material gaskets according to the present invention, in addition to the random copolymer rubber (A), the vulcanizing agent (B) and the filler (C), as described above, Although a sulfur accelerator and a vulcanization aid can be compounded, in addition to the above, a softener, a processing aid, a heat-resistant anti-aging agent, an ultraviolet absorber, a tackifier and other compounding agents for rubber are used in the present invention. Can be blended in a range that does not impair.

Among the rubber compositions for building material gaskets, glazing gaskets which are required to have silicone sealant stain resistance include, as in the case of the vulcanization accelerator and filler (C) described above, silicone sealant stains. Less softener or the like is used.

The rubber composition for an automotive water hose and the rubber composition for a building material gasket according to the present invention can be prepared, for example, by the following method. That is, the rubber composition for an automotive water hose and the rubber composition for a building material gasket according to the present invention are prepared by mixing a random copolymer rubber (A) with a mixer such as a Banbury mixer,
Necessary additives such as filler (C) and softener are
After kneading at a temperature of 70 ° C. for about 3 to 10 minutes, using a roll such as an open roll, a vulcanizing agent (B) and, if necessary, a vulcanization accelerator or a vulcanization aid are additionally mixed. After kneading at a roll temperature of 40 to 80 ° C. for 5 to 30 minutes, the mixture can be prepared by dispensing. The rubber composition thus obtained is a ribbon-shaped or sheet-shaped rubber compound.

The rubber composition for an automotive water hose and the rubber composition for a building material gasket according to the present invention are:
The random copolymer rubber (A), the vulcanizing agent (B), the filler (C) and the above additives are directly supplied to an extruder heated to about 80 to 100 ° C., and the residence time is about 0.5. It can be granulated for 5 minutes to prepare a pellet.

[0074]

According to the present invention, a random copolymer rubber (A) comprising ethylene, an α-olefin having 3 to 20 carbon atoms, and a structural unit derived from the triene compound represented by the general formula [1] is used. Is the molar ratio of ethylene to the branched polyene compound, iodine value and intrinsic viscosity [η]
Is in a specific range, so that a vulcanized rubber excellent in low-temperature flexibility can be provided, and the vulcanization speed is high.

Further, the random copolymer rubber (A)
Has excellent properties such as weather resistance, ozone resistance and heat aging resistance. The rubber composition for an automotive water hose according to the present invention contains the above random copolymer rubber (A), a vulcanizing agent (B), and a filler (C).
A high-speed automotive water hose having excellent low-temperature flexibility and having a small high-temperature compression set can be formed at a high speed without impairing the excellent heat aging resistance, weather resistance, and the like inherently possessed by the above.

The rubber composition for a building material gasket according to the present invention contains the above-mentioned random copolymer rubber (A), vulcanizing agent (B) and filler (C). It is excellent in silicone sealant stain resistance, blooming resistance and low-temperature flexibility, and enables high-speed molding of a building material gasket having a small high-temperature compression set.

Since these rubber compositions have a high vulcanization rate and can complete vulcanization in a short time, the productivity of automobile water hoses and building material gaskets can be improved, and the vulcanization accelerator Since the amount of used can be reduced, the production cost can be reduced.

Hereinafter, the present invention will be described with reference to Examples.
The present invention is not limited to these examples. The evaluation test methods for the ethylene / α-olefin / non-conjugated polyene copolymer rubber and the vulcanized rubber in Examples and Comparative Examples are as follows.

[1] Physical property test of unvulcanized rubber The physical property test of the unvulcanized rubber was performed in accordance with JIS K6300. The scorch stability was measured using a Mooney viscometer (model SMV-202) manufactured by Shimadzu Corporation at 125 ° C. and the change in Mooney viscosity was measured at t ₅ [min].
As a guide. The t ₅ indicates the longer scorch that stability is good. The vulcanization rate was measured at 150 ° C and 170 ° C using a rotorless rheometer (model MDR2000) manufactured by Monsanto Co.
tc (90) was obtained and used as a standard. The shorter the tc (90), the higher the vulcanization rate.

[2] Tensile test A vulcanized rubber sheet was punched out and JIS K6251 (199)
No. 3 dumbbell test piece described in (3 years), and using this test piece, a measurement temperature of 25 ° C. and a tensile speed of 50 were applied in accordance with the method specified in JIS K 6251, Paragraph 3.
Subjected to tensile test at 0 mm / min conditions, the 300% modulus (M _300), tensile stress at break T _B and tensile elongation at break E _B were measured.

[3] Hardness Test The hardness test was performed in accordance with JIS K 6253 (1993), and the spring hardness H _A (Shore A hardness) was measured.

[4] Compression Set Test The compression set test is based on JIS K 6262 (1993).
And the high temperature compression set (C _S ) was determined.

Test conditions for rubber composition for automotive water hose Heating temperature: 120 ° C. Time: 24 hours Load: 10.5 kg Test condition for rubber composition for building material gasket Heating temperature: 100 ° C. Time: 24 hours Load: 10.5 kg [5] Aging test In the example of the rubber composition for an automobile water hose, the aging test was performed by an air heating aging test at 135 ° C. for 70 hours according to JI.
In accordance with SK 6257 (1993), the rate of change in tensile strength (T _B ), the rate of change in elongation (E _B ), and the rate of change in Shore A hardness ( _HA ) were determined. In Examples of the rubber composition for building material gaskets, the aging test was conducted at 100 ° C.
Aging test for 70 hours in JIS K 6257 (1)
993), and a retention rate for physical properties before aging, that is, a tensile strength retention rate A _R (T _B ) and an elongation retention rate A
_R (E _B ) was determined. The rate of change was determined for Shore A hardness ( _HA ).

[6] Antifreeze liquid resistance test The antifreeze liquid resistance test was performed on the rubber composition for automobile water hoses. The antifreeze test is based on JIS K6
258 (1993), tensile strength (T _B )
, The change in elongation (E _B ), the change in Shore A hardness (H _A ), and the volume expansion coefficient.

[7] Glass transition temperature (Tg) The Tg of the ethylene / α-olefin / non-conjugated polyene copolymer rubber was measured by a differential scanning calorimeter (DSC). This Tg is an index of the low-temperature flexibility of the ethylene / α-olefin / non-conjugated polyene copolymer rubber.

Temperature cycling in measurement of Tg by DSC A sample was heated from normal temperature (25 ° C) to 180 ° C at a rate of 20 ° C / min.
After the temperature was raised to 180 ° C. for 2 minutes, the sample was cooled to −80 ° C. at a rate of −20 ° C./min.
The temperature was maintained at 80 ° C., and then the temperature of the sample was raised again at a rate of 20 ° C./min to determine the Tg of the sample.

Further, the ethylene and ethylene used in Examples and Comparative Examples were used.
The α-olefin / non-conjugated polyene copolymer rubber (random copolymer rubber) is as shown in Table 1.

[0088]

[Table 1]

[Examples and Comparative Examples of Rubber Composition for Automotive Water Hose]

[0090]

Example 1 100 parts by weight of the copolymer (1) shown in Table 1, 5 parts by weight of Zinhua No. 3 [manufactured by Sakai Chemical Industry Co., Ltd.], and 1 part by weight of stearic acid [manufactured by Kao Corporation] Parts, 135 parts by weight of FEF carbon black [filler, manufactured by Showa Cabot Co., Ltd.] and paraffin oil [PA-
90] 90 parts by weight and polyethylene glycol # 400
0 [manufactured by Kao Corporation] and 1 part by weight were kneaded for 6 minutes using a 1.7 liter Banbury mixer [manufactured by Kobe Steel Ltd.] to obtain 332 parts by weight of a master batch.

The master batch 3 thus obtained is
32 parts by weight of CBS (vulcanization accelerator, N-cyclohexyl
0.5 parts by weight of 2-benzothiazolesulfenamide), 1.5 parts by weight of ZnBDC (vulcanization accelerator, zinc dibutyldithiocarbamate), 0.5 part of TMTD (vulcanization accelerator, tetramethylthiuram disulfide) Parts by weight, EU
(Vulcanization accelerator, 2-mercaptoimidazoline) 0.5 part by weight, morpholine disulfide (vulcanizing agent, 4,4'-dithiodimorpholine) 1.5 part by weight and sulfur 0.4
After adding the parts by weight and kneading for 15 minutes on an 8-inch roll having a roll width of 20 inches (the temperature of the front roll and the rear roll is 40 ° C.), the mixture is separated into a sheet and 13 minutes at 150 ° C. At 150 ° C. for 18 minutes] to obtain a vulcanized sheet having a thickness of 2 mm.

The obtained vulcanized sheet was subjected to the above-mentioned physical properties test and the like according to the above-mentioned method. Further, for the unvulcanized rubber composition before performing the above vulcanization, according to the above method,
t ₅ (125 ° C.) and t _c (90) (150 ° C.) were determined.

Table 2 shows the results.

[0094]

Example 2 The procedure of Example 1 was repeated, except that the copolymer (2) shown in Table 1 was used instead of the copolymer (1).

Table 2 shows the results.

[0096]

Comparative Examples 1 and 2 In Example 1, copolymer (4) and copolymer (5) shown in Table 1 were used instead of copolymer (1).
At 150 ° C. for 20 minutes [150 for compression set measurement]
At 25 ° C. for 25 minutes] in the same manner as in Example 1.

Table 2 shows the results.

[0098]

[Table 2]

[Examples and Comparative Examples of Rubber Compositions for Building Material Gaskets]

[0100]

Example 3 100 parts by weight of the copolymer (1) shown in Table 1, 5 parts by weight of Zinhua No. 3 [manufactured by Sakai Chemical Industry Co., Ltd.], and 1 part by weight of stearic acid [manufactured by Kao Corporation] Parts, 110 parts by weight of FEF carbon black [filler, manufactured by Showa Cabot Co., Ltd.] and paraffin-based oil [PA-
90] and 75 parts by weight were kneaded for 6 minutes with a 1.7 liter Banbury mixer [manufactured by Kobe Steel Ltd.] to obtain 291 parts by weight of a master batch.

Master batch 2 thus obtained
To 91 parts by weight, 1.5 parts by weight of MBTS (vulcanization accelerator, dibenzothidyl disulfide), 2.5 parts by weight of ZnBDC (vulcanization accelerator, zinc dibutyldithiocarbamate) and 0.7 part by weight of sulfur In addition, an 8-inch roll having a roll width of 20 inches (the temperature of the front roll and the rear roll is 40
C.) for 15 minutes, then dispensed into a sheet,
13 minutes at 0 ° C [18% at 170 ° C for compression set measurement]
Min] and press vulcanization to prepare a vulcanized sheet having a thickness of 2 mm.

The obtained vulcanized sheet was subjected to the above-mentioned physical properties test and the like according to the above-mentioned method. Further, for the unvulcanized rubber composition before performing the above vulcanization, according to the above method,
t ₅ (125 ° C.) and t _c (90) (170 ° C.) were determined.

Table 3 shows the results.

[0104]

Example 4 The procedure of Example 3 was repeated, except that the copolymer (3) shown in Table 1 was used instead of the copolymer (1).

Table 3 shows the results.

[0106]

Comparative Examples 3 and 4 In Example 3, copolymer (4) and copolymer (5) shown in Table 1 were used instead of copolymer (1).
At 170 ° C for 20 minutes [170 for compression set measurement]
At 25 ° C. for 25 minutes] in the same manner as in Example 3.

Table 3 shows the results.

[0108]

[Table 3]

Claims (2)

[Claims] 1. A random copolymer rubber (A) comprising ethylene, an α-olefin having 3 to 20 carbon atoms, and a structural unit derived from a triene compound represented by the following general formula [1]: The random copolymer rubber (A) comprises (i) a molar ratio of ethylene to an α-olefin having 3 to 20 carbon atoms (ethylene / Α-olefin) is in the range of 99/1 to 30/70, (ii) the content of the structural unit derived from the triene compound is 0.1 to 30 mol%, and (iii) 135 ° C.
Intrinsic viscosity [η] measured in decalin is 0.1 to 10 d
1 / g rubber composition for automotive water hoses; [In the formula [1], R ¹ and R ² are each independently a hydrogen atom, a methyl group or an ethyl group, and R ³ and R ⁴ are each independently a methyl group or an ethyl group. ] 2. A random copolymer rubber (A) comprising ethylene, an α-olefin having 3 to 20 carbon atoms and a structural unit derived from a triene compound represented by the following general formula [1]: The random copolymer rubber (A) comprises (i) a molar ratio of ethylene to an α-olefin having 3 to 20 carbon atoms (ethylene / Α-olefin) is in the range of 99/1 to 30/70, (ii) the content of the structural unit derived from the triene compound is 0.1 to 30 mol%, and (iii) 135 ° C.
Intrinsic viscosity [η] measured in decalin is 0.1 to 10 d
a rubber composition for a building material gasket, which is in the range of 1 / g; [In the formula [1], R ¹ and R ² are each independently a hydrogen atom, a methyl group or an ethyl group, and R ³ and R ⁴ are each independently a methyl group or an ethyl group. ]