WO2010038720A1 - Highly saturated copolymer rubber containing nitrile group, cross-linkable rubber composition comprising same, and cross-linked product - Google Patents

Highly saturated copolymer rubber containing nitrile group, cross-linkable rubber composition comprising same, and cross-linked product Download PDF

Info

Publication number
WO2010038720A1
WO2010038720A1 PCT/JP2009/066906 JP2009066906W WO2010038720A1 WO 2010038720 A1 WO2010038720 A1 WO 2010038720A1 JP 2009066906 W JP2009066906 W JP 2009066906W WO 2010038720 A1 WO2010038720 A1 WO 2010038720A1
Authority
WO
WIPO (PCT)
Prior art keywords
monomer unit
nitrile group
unit
highly saturated
copolymer rubber
Prior art date
Application number
PCT/JP2009/066906
Other languages
French (fr)
Japanese (ja)
Inventor
順二 寺田
誠 長屋
新也 池田
Original Assignee
日本ゼオン株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日本ゼオン株式会社 filed Critical 日本ゼオン株式会社
Priority to JP2010531850A priority Critical patent/JP5652205B2/en
Publication of WO2010038720A1 publication Critical patent/WO2010038720A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F236/00—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds
    • C08F236/02—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds
    • C08F236/04—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated
    • C08F236/12—Copolymers of compounds having one or more unsaturated aliphatic radicals, at least one having two or more carbon-to-carbon double bonds the radical having only two carbon-to-carbon double bonds conjugated with nitriles
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08C—TREATMENT OR CHEMICAL MODIFICATION OF RUBBERS
    • C08C19/00—Chemical modification of rubber
    • C08C19/02—Hydrogenation
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L15/00—Compositions of rubber derivatives

Definitions

  • the present invention relates to a nitrile group-containing highly saturated copolymer rubber, a crosslinkable rubber composition containing the nitrile group, and a cross-linked product, and more particularly, a nitrile that provides a cross-linked product having excellent oil resistance and cold resistance and low compression set
  • the present invention relates to a group-containing highly saturated copolymer rubber, a crosslinkable rubber composition containing the same, and a crosslinked product.
  • Nitrile group-containing highly saturated copolymer rubbers typified by hydrogenated acrylonitrile-butadiene copolymer rubber have attracted attention.
  • Nitrile group-containing highly saturated copolymer rubbers are heat and oil resistant compared to common nitrile group-containing copolymer rubbers with many carbon-carbon unsaturated bonds in the main chain structure, such as acrylonitrile-butadiene copolymer rubber. It has the property of being excellent in ozone resistance.
  • the nitrile group-containing copolymer rubber depends on the nitrile group content of the nitrile group-containing highly saturated copolymer rubber and the proportion of unsaturated bonds in the carbon-carbon bond. In some cases, the cold resistance was inferior to that of polymer rubber.
  • nitrile group-containing copolymer rubber cold resistance can be improved by reducing the nitrile group content.
  • a nitrile group-containing highly saturated copolymer rubber even if the nitrile group content is reduced, the cold resistance is not always improved.
  • Patent Document 1 discloses that ⁇ , ⁇ -ethylenically unsaturated nitrile monomer units, ⁇ , ⁇ -ethylenic units are used to improve the cold resistance of nitrile group-containing highly saturated copolymer rubber crosslinked products.
  • Nitrile group-containing highly saturated copolymer rubbers containing unsaturated carboxylic acid ester monomer units, conjugated diene monomer units and saturated conjugated diene monomer units have been proposed.
  • this patent document 1 only the content rate of the monomer unit in the nitrile group containing highly saturated copolymer rubber to be used is shown, and it is not clarified about controlling the glass transition temperature.
  • Patent Document 1 does not disclose an embodiment in which monobutyl maleate or monobutyl fumarate is used as the ⁇ , ⁇ -ethylenically unsaturated carboxylic acid ester monomer unit. Therefore, in this Patent Document 1, the resulting crosslinked product of the nitrile group-containing highly saturated copolymer rubber does not necessarily exhibit a sufficient effect on the requirement for cold resistance, and further, compression set, particularly an O-ring shape. In some cases, the compression set (O-ring compression set) was not sufficient.
  • An object of the present invention is to provide a highly saturated copolymer rubber containing a nitrile group which is excellent in oil resistance and cold resistance and gives a crosslinked product having a small compression set.
  • Another object of the present invention is to provide a cross-linkable rubber composition obtained by adding a cross-linking agent to such a nitrile group-containing highly saturated copolymer rubber and a cross-linked product obtained by cross-linking the same.
  • the inventors of the present invention have used ⁇ , ⁇ -ethylenically unsaturated nitrile monomer units (a) as monomer units constituting nitrile group-containing highly saturated copolymer rubbers.
  • a nitrile group-containing highly saturated copolymer rubber having a temperature difference between the outer glass transition start temperature (Tig) and the extrapolated glass transition end temperature (Teg) of 5 to 11 ° C.
  • a crosslinkable rubber composition comprising the nitrile group-containing highly saturated copolymer rubber and a crosslinking agent.
  • the said crosslinking agent is a polyamine type crosslinking agent.
  • crosslinking the said crosslinkable rubber composition is provided.
  • the cross-linked product of the present invention is preferably an O-ring.
  • the ratio of monomers constituting the monobutyl maleate unit (b1) and / or monobutyl fumarate unit (b2) used at the start of copolymerization is 100% of the total amount of the monomers. It is preferably 10 to 90% by weight with respect to the weight%.
  • a nitrile group-containing highly saturated copolymer rubber and a crosslinkable rubber composition which are excellent in oil resistance and cold resistance and give a cross-linked product having a small compression set, and obtained using these, oil resistance and A crosslinked product having excellent cold resistance and low compression set can be provided.
  • the nitrile group-containing highly saturated copolymer rubber of the present invention comprises ⁇ , ⁇ -ethylenically unsaturated nitrile monomer unit (a) 10 to 60% by weight, monobutyl maleate unit (b1) And / or 0.1 to 20% by weight of monobutyl fumarate unit (b2) and a total of 20 to 89.9% by weight of conjugated diene monomer unit (c) and saturated conjugated diene monomer unit (d)
  • the content of the monomer unit (d) with respect to the total content of the monomer unit (c) and the monomer unit (d) is 70% by weight or more, and differential scanning calorimetry
  • the rubber has a temperature difference between the extrapolation glass transition start temperature (Tig) and the extrapolation glass transition end temperature (Teg) of 5 to 11 ° C.
  • the ⁇ , ⁇ -ethylenically unsaturated nitrile monomer for constituting the ⁇ , ⁇ -ethylenically unsaturated nitrile monomer unit (a) is as follows: Examples include acrylonitrile; ⁇ -halogenoacrylonitrile such as ⁇ -chloroacrylonitrile and ⁇ -bromoacrylonitrile; and ⁇ -alkylacrylonitrile such as methacrylonitrile and ethacrylonitrile. Of these, acrylonitrile is preferred. These ⁇ , ⁇ -ethylenically unsaturated nitrile monomers may be used alone or in combination of two or more.
  • the content of the ⁇ , ⁇ -thylene unsaturated nitrile monomer unit (a) in the nitrile group-containing highly saturated copolymer rubber is 10 to 60% by weight, preferably 10 to 45% by weight, more preferably 15 to 40% by weight.
  • the content of the ⁇ , ⁇ -ethylenically unsaturated nitrile monomer unit (a) is too small, the oil resistance of the resulting crosslinked product tends to be lowered. On the other hand, if the amount is too large, the cold resistance of the resulting crosslinked product tends to decrease.
  • the content of the monobutyl maleate unit (b1) and / or the monobutyl fumarate unit (b2) (hereinafter referred to as monomer units (b1) and (b2) as appropriate) is 0.1 to 20% by weight, Preferably, the content is 0.5 to 10% by weight, more preferably 1 to 7% by weight.
  • the nitrile group-containing highly saturated copolymer rubber contains a specific amount of monobutyl maleate unit (b1) and / or monobutyl fumarate unit (b2).
  • a crosslinkable rubber composition having an excellent balance between cold resistance and oil resistance can be obtained by crosslinking the crosslinkable rubber composition.
  • Monomers for constituting the conjugated diene monomer unit (c) include 1,3-butadiene, isoprene, 2,3-dimethyl-1, Examples thereof include conjugated dienes such as 3-butadiene and 1,3-pentadiene. Of these, 1,3-butadiene is preferred.
  • the monomer unit (c) is obtained by copolymerizing a conjugated diene and has a carbon-carbon double bond remaining.
  • the carbon-carbon double bond of the monomer unit (c) was saturated by hydrogenation.
  • the ⁇ -olefin preferably has 2 to 12 carbon atoms, and examples thereof include ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene and 1-octene.
  • the saturated conjugated diene monomer unit (d) is preferably obtained by hydrogenating a carbon-carbon double bond of a conjugated diene unit.
  • the total content of the monomer unit (c) and the monomer unit (d) in the nitrile group-containing highly saturated copolymer rubber is 20 in total as the monomer unit (c) and the monomer unit (d). -89.9% by weight, preferably 45-89.5% by weight, more preferably 53-84% by weight. If the total content of the monomer unit (c) and the monomer unit (d) is too small, the rubber elasticity of the resulting crosslinked product tends to be lowered. On the other hand, if the amount is too large, the cold resistance and oil resistance of the resulting crosslinked product tend to decrease.
  • the total content of the monomer unit (c) and the monomer unit (d) in the nitrile group-containing highly saturated copolymer rubber is 100% by weight, a single amount relative to the total content
  • the proportion of the body unit (d) is 70% by weight or more, preferably 75% by weight or more, more preferably 80% by weight or more, and particularly preferably 90% by weight or more. If the ratio of the monomer unit (d) to the total content of the monomer unit (c) and the monomer unit (d) is too low (that is, the saturation is too low), a cross-linked product is obtained. The heat resistance of the steel tends to be reduced.
  • an ⁇ , ⁇ -ethylenically unsaturated nitrile monomer, monobutyl maleate, monobutyl fumarate, conjugated diene, and ⁇ -- are used as long as the effects of the present invention are not impaired. It may contain other monomer units copolymerizable with olefins. Other monomers that form monomer units include ⁇ , ⁇ -ethylenically unsaturated groups other than monobutyl maleate and monobutyl fumarate, such as methyl acrylate, ethyl methacrylate, dimethyl maleate, and diethyl fumarate.
  • Carboxylic acid esters ⁇ , ⁇ -ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and fumaric acid; ⁇ , ⁇ -ethylenically unsaturated polyvalent carboxylic acid anhydrides such as maleic anhydride; styrene, Aromatic vinyl monomers such as vinyl pyridine; fluorine-containing vinyl monomers such as fluoroethyl vinyl ether and tetrafluoroethylene; copolymerizable anti-aging agents such as N- (4-anilinophenyl) acrylamide; . These may be used individually by 1 type and may use multiple types together. The content of these other copolymerizable monomer units is preferably 50% by weight or less, more preferably 10% by weight or less, and particularly preferably 1% by weight or less in 100% by weight of all monomer units. It is.
  • the Mooney viscosity [ML 1 + 4 (100 ° C.)] of the nitrile group-containing highly saturated copolymer rubber of the present invention is preferably 10 to 100, and more preferably 40 to 100.
  • Mooney viscosity of the nitrile group-containing highly saturated copolymer rubber is too low, mechanical strength such as tensile strength of the resulting crosslinked product tends to decrease.
  • the Mooney viscosity of the nitrile group-containing highly saturated copolymer rubber is too high, the processability tends to decrease.
  • the nitrile group-containing highly saturated copolymer rubber of the present invention has a temperature difference ( ⁇ T) of 5 to 11 ° C. between the extrapolated glass transition start temperature (Tig) and the extrapolated glass transition end temperature (Teg) in differential scanning calorimetry.
  • the temperature is preferably 6 to 10 ° C, more preferably 7 to 10 ° C.
  • the temperature difference ( ⁇ T) can be measured in accordance with JIS K7121 “Plastic transition temperature measurement method”. By controlling this temperature difference ( ⁇ T) within the above range, the cold resistance of the resulting crosslinked product can be improved.
  • the nitrile group-containing highly saturated copolymer rubber of the present invention includes, for example, each monomer that constitutes each monomer unit (a), (b1), (b2), (c), (d). It can be produced by preparing a monomer mixture to be contained, copolymerizing the monomer mixture, and selectively hydrogenating the obtained copolymer.
  • a monomer mixture containing each monomer constituting each monomer unit (a), (b1), (b2), (c), (d) is prepared.
  • the ⁇ , ⁇ -ethylenically unsaturated nitrile monomer constituting the monomer unit (a), the monomer unit (b1) and / or the monomer unit (b2) By preparing monobutyl maleate and / or monobutyl fumarate to be constituted and conjugated diene monomer that will constitute the monomer units (c) and (d), and mixing them, A monomer mixture is prepared.
  • monobutyl maleate and / or monobutyl fumarate a monomer mixture is prepared using a part of monobutyl maleate and / or monobutyl fumarate used for polymerization.
  • copolymerization is performed using the obtained monomer mixture.
  • a copolymerization method any of an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, and a solution polymerization method can be used. From the viewpoint of ease of control of the polymerization reaction, etc., as a conventionally known rubber production method, The polymerization is preferably carried out by a commonly used emulsion polymerization method under normal pressure.
  • the remainder of monobutyl maleate and / or monobutyl fumarate used for polymerization is added during the copolymerization of the monomer mixture. That is, in the present invention, the copolymerization is started in a state where only a part of monobutyl maleate and / or monobutyl fumarate used for the polymerization is added to the monomer mixture used for the copolymerization.
  • the method of adding the remainder in the middle of copolymerization is employ
  • the ratio of monobutyl maleate and / or monobutyl fumarate previously contained in the monomer mixture with respect to the total of these is preferably 10 to 90% by weight, more preferably 20 to 80% by weight, still more preferably Is 40 to 70% by weight.
  • the proportion of monobutyl maleate and / or monobutyl fumarate added during the copolymerization is preferably 10 to 90% by weight, more preferably 20 to 80% by weight, still more preferably 30 to 60% by weight. It is.
  • the addition time of monobutyl maleate and / or monobutyl fumarate to be additionally added during the copolymerization is not particularly limited, but the copolymerization of the monomer mixture starts, and the polymerization conversion rate is preferably 10 to 75. %, More preferably 15 to 70%, still more preferably 20 to 65%.
  • the first addition is performed when the polymerization conversion rate is preferably 10% or more and less than 50%, and the polymerization conversion rate is preferably 50 to 75%. It is preferable to perform the second addition at this point.
  • the nitrile group-containing highly saturated copolymer rubber of the present invention can be produced by selectively hydrogenating the obtained copolymer.
  • the type and amount of the hydrogenation catalyst used for hydrogenation, the hydrogenation temperature, etc. may be determined according to known methods.
  • crosslinkable rubber composition of the present invention comprises the above nitrile group-containing highly saturated copolymer rubber and a crosslinking agent.
  • crosslinking agent conventionally used for crosslinking rubber such as polyamine compounds, organic peroxides, polyvalent epoxy compounds, polyvalent isocyanate compounds, aziridine compounds, sulfur compounds, basic metal oxides and organometallic halides.
  • a known crosslinking agent can be used.
  • polyamine compounds and organic peroxides are preferable, and a polyamine compound (hereinafter referred to as “polyamine-based cross-linking agent”) is more preferable because a rubber cross-linked product having excellent mechanical properties and low compression set is easily obtained. .
  • the polyamine-based crosslinking agent is not particularly limited as long as it is (1) a compound having two or more amino groups, or (2) a compound having two or more amino groups at the time of crosslinking.
  • a compound in which a plurality of hydrogen atoms of an aromatic hydrocarbon or aromatic hydrocarbon are substituted with an amino group or a hydrazide structure (a structure represented by —CONHNH 2 , CO represents a carbonyl group) is preferable.
  • aliphatic polyvalent amines such as hexamethylenediamine, hexamethylenediamine carbamate, tetramethylenepentamine, hexamethylenediamine cinnamaldehyde adduct, hexamethylenediamine dibenzoate salt; 2,2-bis ⁇ 4- Aromatic polyamines such as (4-aminophenoxy) phenyl ⁇ propane, 4,4′-methylenedianiline, m-phenylenediamine, p-phenylenediamine, 4,4′-methylenebis (o-chloroaniline); Compounds having two or more hydrazide structures such as isophthalic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, and the like are mentioned, and hexamethylenediamine carbamate is particularly preferable.
  • aliphatic polyvalent amines such as hexamethylenediamine, hexamethylenediamine carb
  • the content of the crosslinking agent in the crosslinkable rubber composition of the present invention is preferably 0.2 to 20 parts by weight, more preferably 1 to 15 parts by weight with respect to 100 parts by weight of the nitrile group-containing highly saturated copolymer rubber. Particularly preferred is 1.5 to 10 parts by weight. If the content of the crosslinking agent is too small, it may be difficult to obtain a rubber cross-linked product having excellent tensile stress and low compression set. Conversely, if it is too high, the bending fatigue resistance of the rubber cross-linked product may be reduced. There is.
  • the crosslinkable rubber composition of the present invention contains a compounding agent usually used in the rubber processing field, for example, a crosslinking accelerator, a crosslinking aid, a crosslinking delay.
  • a crosslinking accelerator for example, a crosslinking accelerator, a crosslinking aid, a crosslinking delay.
  • Agent reinforcing filler (carbon black, silica, etc.), non-reinforcing filler (calcium carbonate, clay, etc.), anti-aging agent, antioxidant, light stabilizer, primary amine scorch inhibitor, plasticizer, Processing aids, lubricants, adhesives, lubricants, flame retardants, antifungal agents, acid acceptors, antistatic agents, colorants, and the like can be blended.
  • the compounding amount of these compounding agents is not particularly limited as long as the effect of the present invention is not impaired, and an amount corresponding to the compounding purpose can be appropriately compounded.
  • a rubber other than the nitrile group-containing highly saturated copolymer rubber of the present invention described above may be blended as long as the effects of the present invention are not impaired.
  • the amount of rubber other than the nitrile group-containing highly saturated copolymer rubber of the present invention is usually 30 parts by weight or less, preferably 20 parts by weight or less, based on 100 parts by weight of the nitrile group-containing highly saturated copolymer rubber of the present invention. More preferably, it is 10 parts by weight or less.
  • Examples of such rubbers include acrylic rubber, ethylene-acrylic acid copolymer rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber (excluding hydride), polybutadiene rubber, and ethylene-propylene copolymer rubber.
  • Ethylene-propylene-diene terpolymer rubber epichlorohydrin rubber, urethane rubber, chloroprene rubber, silicone rubber, fluorine rubber, natural rubber, polyisoprene rubber and the like.
  • the crosslinkable rubber composition of the present invention may be prepared by a general method for preparing a rubber composition in the same manner as other rubber compositions, and may be kneaded using a closed mixer or an open roll.
  • a crosslinking agent or crosslinking aid it is also common to adjust the temperature so that it does not crosslink during kneading after the blending of the crosslinking agent or crosslinking aid so that it is below the crosslinking start temperature. This is the same as the method for preparing a rubber composition.
  • these crosslinking-related components are blended at a temperature lower than the crosslinking initiation temperature corresponding to them. , Mix.
  • Cross-linked product The cross-linked product of the present invention is obtained by cross-linking the cross-linkable rubber composition of the present invention described above.
  • the method for crosslinking the crosslinkable rubber composition is not particularly limited, but the temperature during crosslinking is preferably 100 to 200 ° C, more preferably 130 to 180 ° C. If the temperature at the time of crosslinking is too low, the crosslinking time may be required for a long time, or the crosslinking density of the resulting crosslinked product may be lowered. If the temperature at the time of crosslinking is too high, molding failure may occur.
  • the crosslinking time varies depending on the crosslinking method, the crosslinking temperature, the shape of the crosslinked product, etc., but is preferably in the range of 1 minute or more and 5 hours or less from the viewpoint of the crosslinking density and production efficiency of the obtained crosslinked product.
  • the heating method for crosslinking may be appropriately selected from methods usually used for rubber crosslinking such as press heating, steam heating, oven heating, and hot air heating.
  • the cross-linked product of the present invention thus obtained is obtained by using the nitrile group-containing highly saturated copolymer rubber of the present invention described above, and therefore has excellent oil resistance and cold resistance, compression set, particularly O -It has a characteristic that the compression set (O-ring compression set) in the case of a ring-shaped molded product is small.
  • Such a cross-linked product of the present invention makes use of its characteristics to provide O-rings, packings, diaphragms, oil seals, shaft seals, bearing seals, mechanical seals, well head seals, electrical / electronic device seals, pneumatic pressure Equipment seals, chlorofluorocarbon or fluorohydrocarbon or carbon dioxide sealing seals used in air conditioner cooling devices or air conditioner refrigerator compressors, supercritical carbon dioxide or sublimation used in cleaning media for precision cleaning Seals for sealing critical carbon dioxide, seals for rolling devices (rolling bearings, automotive hub units, automotive water pumps, linear guide devices, ball screws, etc.), valves and valve seats, BOP (Blow Out Preventar), platters Rubber members for various seals such as Intake manifold gaskets attached to the connecting portion between the intake manifold and the cylinder head, cylinder head gaskets attached to the connecting portion between the cylinder block and the cylinder head, and rockers attached to the connecting portion between the rocker cover and the cylinder head A cover gasket, an oil pan gasket
  • the rubber cross-linked product of the present invention includes various rolls such as a printing roll, a steel roll, a paper roll, an industrial roll, and an office machine roll; a flat belt (film core flat belt, cord flat belt, laminated flat belt). Belts, single unit flat belts, etc.), V belts (wrapped V belts, low edge V belts, etc.), V ribbed belts (single V ribbed belt, double V ribbed belt, wrapped V ribbed belt, back rubber V ribbed belt, upper cog V ribbed belt, etc.), CVT Belts such as belts, timing belts, toothed belts, conveyor belts, fuel hoses, turbo air hoses, oil hoses, radiator hoses, heater hoses, water hoses, vacuum brake hoses, control hoses, air conditioning hoses, brake hoses, Power steering ho Various hoses such as springs, air hoses, marine hoses, risers, flow lines; various boots such as CVJ
  • Glass transition temperature Nitrile group-containing highly saturated copolymer rubber was subjected to heat flux differential scanning calorimetry in accordance with JIS K7121, and extrapolated glass transition start temperature (Tig) and extrapolated glass transition end temperature (Teg).
  • the heating rate was changed from 20 ° C./min to 10 ° C./min.
  • ⁇ T is the absolute value of the difference between Teg and Tig.
  • Mooney viscosity (Polymer Mooney) The Mooney viscosity (polymer Mooney, [ML 1 + 4 (100 ° C.)]) of the highly saturated copolymer rubber containing nitrile group was measured according to JIS K6300-1.
  • the tensile strength and elongation of the crosslinked product are measured according to JIS K6251, and the hardness of the crosslinked product is measured using a durometer hardness tester type A according to JIS K6253. Was measured.
  • Cold resistance (Geman torsion test) The cold resistance of the rubber cross-linked product was evaluated by measuring T 10 (° C.) according to JIS K 6261. The temperature of the T 10 is determined to excellent low enough cold resistance.
  • Disk compression set (Disk set test) Using a mold having an inner diameter of 29 mm and a depth of 12.5 mm, the crosslinkable rubber composition is press-molded at 170 ° C. for 20 minutes while being pressurized to obtain a sheet-like cross-linked product, which is put into a gear-type oven. A test piece for a disk set test was obtained by performing secondary crosslinking at 170 ° C. for 4 hours. And the disk compression set was measured according to JISK6262 on the conditions hold
  • O-ring compression set (O-ring set test) Using a mold having an inner diameter of 30 mm and a ring diameter of 3 mm, the cross-linkable rubber composition is press-molded at 170 ° C. for 20 minutes while being pressurized to obtain a ring-shaped cross-linked product, which is 170 in a gear-type oven.
  • a test piece for an O-ring set test was obtained by performing secondary crosslinking at 4 ° C. for 4 hours. Then, using the obtained test piece, the distance between the two planes sandwiching the O-ring was compressed by 25% in the ring thickness direction and maintained at 150 ° C. for 168 hours, and at 150 ° C. for 504 hours.
  • the O-ring compression set was measured in accordance with JIS K6262 under the two conditions of holding.
  • Example 1 In a reactor, 180 parts of ion-exchanged water, 25 parts of a 10% strength by weight sodium dodecylbenzenesulfonate aqueous solution, 37 parts of acrylonitrile, 3 parts of mono-n-butyl maleate, 0.5 part of t-dodecyl mercaptan (molecular weight regulator) In this order, the internal gas was replaced with nitrogen three times, and then 57 parts of 1,3-butadiene was charged.
  • the polymerization reaction was stopped by adding 0.1 part of a 10% strength by weight aqueous solution of hydridoquinone (polymerization terminator), then the residual monomer was removed using a rotary evaporator at a water temperature of 60 ° C., and acrylonitrile-butadiene-maleic acid mono An n-butyl copolymer rubber latex (solid content concentration of about 30% by weight) was obtained.
  • a palladium catalyst (ion exchange water equal in weight to 1 wt% palladium acetate acetone solution) was added to the autoclave so that the palladium content was 1000 ppm with respect to the dry rubber weight contained in the latex.
  • the mixed solution was added and a hydrogenation reaction was performed at a hydrogen pressure of 3 MPa and a temperature of 50 ° C. for 6 hours to obtain a nitrile group-containing highly saturated copolymer rubber latex.
  • the resulting nitrile group-containing highly saturated copolymer rubber latex was added with twice the volume of methanol to coagulate the nitrile group-containing highly saturated copolymer rubber, and then vacuum dried at 60 ° C. for 12 hours to obtain a nitrile group-containing highly saturated copolymer rubber.
  • a polymer rubber was obtained.
  • Table 1 shows the content and physical properties of each monomer unit in the entire polymer of the obtained nitrile group-containing highly saturated copolymer rubber.
  • the content ratio of the monomer unit in the nitrile group-containing highly saturated copolymer rubber is a value determined based on 1 H-NMR.
  • FEF carbon black (Asahi 60, manufactured by Asahi Carbon Co., Ltd.), trimellitic acid ester (Adekasizer C-8, Asahi Denka Co., Ltd., plasticizer) 5 parts, stearic acid (crosslinking accelerator) 1 part, 4,4′-di- ( ⁇ , ⁇ ′-dimethylbenzyl) diphenylamine (Naugard 445, Crompton, anti-aging agent) ) 1.5 parts and 1.5 parts of 2-mercaptobenzimidazole (NOCRACK MB, manufactured by Ouchi Shinsei Co., Ltd., anti-aging agent) are added and mixed, then the mixture is transferred to a roll and 1,3- 2 parts of di-o-tolylguanidine (Noxeller DT, manufactured by Ouchi Shinsei Co., Ltd., crosslinking accelerator) and hexamethylenediamine carbamate (Diak # 1, Duponder) 2.5 parts of a crosslinker manufactured by E
  • Example 2 The amount of mono n-butyl maleate used at the start of the polymerization was 2 parts, and the timing and amount of the middle addition of mono n-butyl maleate were 2 parts when the polymerization conversion was 40%, and the polymerization conversion was 60%.
  • a nitrile group-containing highly saturated copolymer rubber having the composition shown in Table 1 was prepared in the same manner as in Example 1 except that the amount was further 2 parts. Evaluation was performed. The results are shown in Table 1.
  • Comparative Example 1 A nitrile group-containing highly saturated composition having the composition shown in Table 1 was used in the same manner as in Example 1 except that the amount of mono-n-butyl maleate used at the start of the polymerization was 6 parts and no monobutyl maleate was added. A copolymer rubber was prepared, a crosslinked product was obtained in the same manner, and each evaluation was performed. The results are shown in Table 1.
  • a mono-n-butyl maleate unit (b1) is contained at a predetermined ratio, and a temperature difference ( ⁇ T) between the extrapolation glass transition start temperature (Tig) and the extrapolation glass transition end temperature (Teg).
  • ⁇ T temperature difference between the extrapolation glass transition start temperature (Tig) and the extrapolation glass transition end temperature (Teg).
  • the cross-linked product obtained by using a nitrile group-containing highly saturated copolymer rubber having a temperature of 5 to 11 ° C. has excellent cold resistance while maintaining good normal state properties, Disk compression set, and O-ring compression strain was smaller (excellent) (Examples 1 and 2).

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Abstract

Disclosed is a highly saturated copolymer rubber containing a nitrile group, which comprises 10 to 60 wt% of an α,β-ethylenically unsaturated nitrile monomer unit (a), 0.1 to 20 wt% of a monobutyl maleate unit (b1) and/or a monobutyl fumarate unit (b2), and a conjugated diene monomer unit (c) and a saturated conjugated diene monomer unit (d) in the total amount of 20 to 89.9 wt%, wherein the content of the monomer unit (d) relative to the total content of the monomer unit (c) and the monomer unit (d) is 70 wt% or more.  The highly saturated copolymer rubber containing a nitrile group has a difference between the extrapolated onset temperature for glass transition (Tig) and the extrapolated end temperature for glass transition (Teg) of 5 to 11°C as measured by differential scanning calorimetry.

Description

ニトリル基含有高飽和共重合ゴム、これを含有する架橋性ゴム組成物および架橋物Nitrile group-containing highly saturated copolymer rubber, crosslinkable rubber composition and crosslinked product containing the same
　本発明は、ニトリル基含有高飽和共重合ゴム、これを含有する架橋性ゴム組成物および架橋物に係り、さらに詳しくは、耐油性および耐寒性に優れ、圧縮永久ひずみの小さい架橋物を与えるニトリル基含有高飽和共重合ゴム、これを含有する架橋性ゴム組成物および架橋物に関する。 The present invention relates to a nitrile group-containing highly saturated copolymer rubber, a crosslinkable rubber composition containing the nitrile group, and a cross-linked product, and more particularly, a nitrile that provides a cross-linked product having excellent oil resistance and cold resistance and low compression set The present invention relates to a group-containing highly saturated copolymer rubber, a crosslinkable rubber composition containing the same, and a crosslinked product.
　近年、水素化アクリロニトリル－ブタジエン共重合ゴムによって代表されるニトリル基含有高飽和共重合ゴムが注目されている。ニトリル基含有高飽和共重合ゴムは、アクリロニトリル－ブタジエン共重合ゴムなどの、主鎖構造に炭素－炭素間不飽和結合の多い一般的なニトリル基含有共重合ゴムに比べて、耐熱性、耐油性、耐オゾン性などに優れるという性質を有している。 Recently, nitrile group-containing highly saturated copolymer rubbers typified by hydrogenated acrylonitrile-butadiene copolymer rubber have attracted attention. Nitrile group-containing highly saturated copolymer rubbers are heat and oil resistant compared to common nitrile group-containing copolymer rubbers with many carbon-carbon unsaturated bonds in the main chain structure, such as acrylonitrile-butadiene copolymer rubber. It has the property of being excellent in ozone resistance.
　しかし、このようなニトリル基含有高飽和共重合ゴムにおいては、ニトリル基含有高飽和共重合ゴムのニトリル基含有量や炭素－炭素間結合中の不飽和結合の割合などによっては、ニトリル基含有共重合ゴムに比べて耐寒性に劣る場合があった。 However, in such a nitrile group-containing highly saturated copolymer rubber, the nitrile group-containing copolymer rubber depends on the nitrile group content of the nitrile group-containing highly saturated copolymer rubber and the proportion of unsaturated bonds in the carbon-carbon bond. In some cases, the cold resistance was inferior to that of polymer rubber.
　一般的に、ニトリル基含有共重合ゴムにおいては、ニトリル基含量を低減させることにより、耐寒性を改良することができる。しかし、ニトリル基含有高飽和共重合ゴムにおいては、ニトリル基含量を低減させても、必ずしも耐寒性が改良されるとは限らない。 Generally, in a nitrile group-containing copolymer rubber, cold resistance can be improved by reducing the nitrile group content. However, in a nitrile group-containing highly saturated copolymer rubber, even if the nitrile group content is reduced, the cold resistance is not always improved.
　これに対して、たとえば、特許文献１では、ニトリル基含有高飽和共重合ゴム架橋物の耐寒性を向上させるため、α，β－エチレン性不飽和ニトリル単量体単位、α，β－エチレン性不飽和カルボン酸エステル単量体単位、共役ジエン単量体単位および飽和化共役ジエン単量体単位を含有するニトリル基含有高飽和共重合ゴムが提案されている。しかしながら、この特許文献１においては、用いるニトリル基含有高飽和共重合ゴム中の単量体単位の含有割合が示されているのみであり、ガラス転移温度を制御する点について明らかにされていない。また、この特許文献１では、α，β－エチレン性不飽和カルボン酸エステル単量体単位として、マレイン酸モノブチルやフマル酸モノブチルを用いた態様は開示されていない。そのため、この特許文献１では、得られるニトリル基含有高飽和共重合ゴムの架橋物は、必ずしも、耐寒性に対する要求に十分な効果を示さなかったり、さらには、圧縮永久ひずみ、特にＯ－リング形状の成形体とした場合における圧縮永久ひずみ（Ｏ－リング圧縮永久ひずみ）が十分でない場合があった。 In contrast, for example, Patent Document 1 discloses that α, β-ethylenically unsaturated nitrile monomer units, α, β-ethylenic units are used to improve the cold resistance of nitrile group-containing highly saturated copolymer rubber crosslinked products. Nitrile group-containing highly saturated copolymer rubbers containing unsaturated carboxylic acid ester monomer units, conjugated diene monomer units and saturated conjugated diene monomer units have been proposed. However, in this patent document 1, only the content rate of the monomer unit in the nitrile group containing highly saturated copolymer rubber to be used is shown, and it is not clarified about controlling the glass transition temperature. Further, Patent Document 1 does not disclose an embodiment in which monobutyl maleate or monobutyl fumarate is used as the α, β-ethylenically unsaturated carboxylic acid ester monomer unit. Therefore, in this Patent Document 1, the resulting crosslinked product of the nitrile group-containing highly saturated copolymer rubber does not necessarily exhibit a sufficient effect on the requirement for cold resistance, and further, compression set, particularly an O-ring shape. In some cases, the compression set (O-ring compression set) was not sufficient.
特開昭６３－９５２４２号公報JP-A 63-95242
　本発明は、耐油性および耐寒性に優れ、圧縮永久ひずみの小さい架橋物を与えるニトリル基含有高飽和共重合ゴムを提供することを目的とする。また、本発明は、このようなニトリル基含有高飽和共重合ゴムに、架橋剤を添加してなる架橋性ゴム組成物およびこれを架橋してなる架橋物を提供することも目的とする。 An object of the present invention is to provide a highly saturated copolymer rubber containing a nitrile group which is excellent in oil resistance and cold resistance and gives a crosslinked product having a small compression set. Another object of the present invention is to provide a cross-linkable rubber composition obtained by adding a cross-linking agent to such a nitrile group-containing highly saturated copolymer rubber and a cross-linked product obtained by cross-linking the same.
　本発明者らは、上記課題を解決すべく鋭意研究した結果、ニトリル基含有高飽和共重合ゴムを構成する単量体単位として、α，β－エチレン性不飽和ニトリル単量体単位（ａ）、共役ジエン単量体単位（ｃ）および飽和化共役ジエン単量体単位（ｄ）を特定量有するとともに、マレイン酸モノブチル単位（ｂ１）および／またはフマル酸モノブチル単位（ｂ２）を特定量含有させ、ニトリル基含有高飽和共重合ゴムの示差走査熱量測定における補外ガラス転移開始温度（Ｔｉｇ）と補外ガラス転移終了温度（Ｔｅｇ）の温度差を５～１１℃の範囲に制御することにより、上記目的を達成できることを見出し、本発明を完成させるに至った。 As a result of diligent research to solve the above-mentioned problems, the inventors of the present invention have used α, β-ethylenically unsaturated nitrile monomer units (a) as monomer units constituting nitrile group-containing highly saturated copolymer rubbers. A specific amount of the conjugated diene monomer unit (c) and the saturated conjugated diene monomer unit (d), and a specific amount of the monobutyl maleate unit (b1) and / or the monobutyl fumarate unit (b2). By controlling the temperature difference between the extrapolated glass transition start temperature (Tig) and the extrapolated glass transition end temperature (Teg) in the differential scanning calorimetry of the highly saturated copolymer rubber containing nitrile group to a range of 5 to 11 ° C., The inventors have found that the above object can be achieved and have completed the present invention.
　すなわち、本発明によれば、α，β－エチレン性不飽和ニトリル単量体単位（ａ）１０～６０重量％、マレイン酸モノブチル単位（ｂ１）および／またはフマル酸モノブチル単位（ｂ２）０．１～２０重量％、ならびに、共役ジエン単量体単位（ｃ）および飽和化共役ジエン単量体単位（ｄ）の合計２０～８９．９重量％を含有し、前記単量体単位（ｃ）と前記単量体単位（ｄ）との合計含有量に対する前記単量体単位（ｄ）の含有量が７０重量％以上であるニトリル基含有高飽和共重合ゴムであって、示差走査熱量測定における補外ガラス転移開始温度（Ｔｉｇ）と補外ガラス転移終了温度（Ｔｅｇ）の温度差が５～１１℃であるニトリル基含有高飽和共重合ゴムが提供される。 That is, according to the present invention, α, β-ethylenically unsaturated nitrile monomer unit (a) 10 to 60% by weight, monobutyl maleate unit (b1) and / or monobutyl fumarate unit (b2) 0.1 And a total of 20 to 89.9% by weight of the conjugated diene monomer unit (c) and the saturated conjugated diene monomer unit (d), and the monomer unit (c) A nitrile group-containing highly saturated copolymer rubber in which the content of the monomer unit (d) is 70% by weight or more with respect to the total content of the monomer unit (d), and is a supplement in differential scanning calorimetry. There is provided a nitrile group-containing highly saturated copolymer rubber having a temperature difference between the outer glass transition start temperature (Tig) and the extrapolated glass transition end temperature (Teg) of 5 to 11 ° C.
　本発明によれば、上記ニトリル基含有高飽和共重合ゴムと、架橋剤と、を含有してなる架橋性ゴム組成物が提供される。
　また、上記架橋剤が、ポリアミン系架橋剤であることが好ましい。
　そして、本発明によれば、上記架橋性ゴム組成物を架橋してなる架橋物が提供される。本発明の架橋物は、好ましくはＯ－リングである。 According to the present invention, there is provided a crosslinkable rubber composition comprising the nitrile group-containing highly saturated copolymer rubber and a crosslinking agent.
Moreover, it is preferable that the said crosslinking agent is a polyamine type crosslinking agent.
And according to this invention, the crosslinked material formed by bridge | crosslinking the said crosslinkable rubber composition is provided. The cross-linked product of the present invention is preferably an O-ring.
　さらに、本発明によれば、上記ニトリル基含有高飽和共重合ゴムを製造する方法であって、前記α，β－エチレン性不飽和ニトリル単量体単位（ａ）、前記共役ジエン単量体単位（ｃ）および前記飽和化共役ジエン単量体単位（ｄ）を構成することとなる単量体の全量、ならびに、前記マレイン酸モノブチル単位（ｂ１）および／またはフマル酸モノブチル単位（ｂ２）を構成することとなる単量体の全量のうち一部を用いて、共重合を開始し、次いで、重合転化率が１０～７５％となった時点で、マレイン酸モノブチル単位（ｂ１）および／またはフマル酸モノブチル単位（ｂ２）を構成することとなる単量体の全量のうちの残部を追加添加して共重合体を得た後、該共重合体に対して、選択的に水素添加するニトリル基含有高飽和共重合体ゴムの製造方法が提供される。 Further, according to the present invention, there is provided a method for producing the above nitrile group-containing highly saturated copolymer rubber, the α, β-ethylenically unsaturated nitrile monomer unit (a), the conjugated diene monomer unit. (C) and the total amount of monomers constituting the saturated conjugated diene monomer unit (d) and the monobutyl maleate unit (b1) and / or the monobutyl fumarate unit (b2) Copolymerization was started using a part of the total amount of monomers to be produced, and then when the polymerization conversion rate reached 10 to 75%, the monobutyl maleate unit (b1) and / or fumarate A nitrile group selectively hydrogenated with respect to the copolymer after adding the remainder of the total amount of monomers constituting the acid monobutyl unit (b2) to obtain a copolymer High saturation copolymerization A method for producing body rubber is provided.
　本発明の製造方法において、共重合開始時に用いる前記マレイン酸モノブチル単位（ｂ１）および／またはフマル酸モノブチル単位（ｂ２）を構成することとなる単量体の比率が、該単量体の全量１００重量％に対して１０～９０重量％であることが好ましい。 In the production method of the present invention, the ratio of monomers constituting the monobutyl maleate unit (b1) and / or monobutyl fumarate unit (b2) used at the start of copolymerization is 100% of the total amount of the monomers. It is preferably 10 to 90% by weight with respect to the weight%.
　本発明によれば、耐油性および耐寒性に優れ、圧縮永久ひずみの小さい架橋物を与えるニトリル基含有高飽和共重合ゴムおよび架橋性ゴム組成物、ならびに、これらを用いて得られ、耐油性および耐寒性に優れ、圧縮永久ひずみの小さい架橋物を提供することができる。 According to the present invention, a nitrile group-containing highly saturated copolymer rubber and a crosslinkable rubber composition which are excellent in oil resistance and cold resistance and give a cross-linked product having a small compression set, and obtained using these, oil resistance and A crosslinked product having excellent cold resistance and low compression set can be provided.
　ニトリル基含有高飽和共重合ゴム
　本発明のニトリル基含有高飽和共重合ゴムは、α，β－エチレン性不飽和ニトリル単量体単位（ａ）１０～６０重量％、マレイン酸モノブチル単位（ｂ１）および／またはフマル酸モノブチル単位（ｂ２）０．１～２０重量％、ならびに、共役ジエン単量体単位（ｃ）および飽和化共役ジエン単量体単位（ｄ）の合計２０～８９．９重量％を含有し、前記単量体単位（ｃ）と前記単量体単位（ｄ）との合計含有量に対する前記単量体単位（ｄ）の含有量が７０重量％以上であり、示差走査熱量測定における補外ガラス転移開始温度（Ｔｉｇ）と補外ガラス転移終了温度（Ｔｅｇ）の温度差が５～１１℃のゴムである。 Nitrile Group-Containing Highly Saturated Copolymer Rubber The nitrile group-containing highly saturated copolymer rubber of the present invention comprises α, β-ethylenically unsaturated nitrile monomer unit (a) 10 to 60% by weight, monobutyl maleate unit (b1) And / or 0.1 to 20% by weight of monobutyl fumarate unit (b2) and a total of 20 to 89.9% by weight of conjugated diene monomer unit (c) and saturated conjugated diene monomer unit (d) The content of the monomer unit (d) with respect to the total content of the monomer unit (c) and the monomer unit (d) is 70% by weight or more, and differential scanning calorimetry The rubber has a temperature difference between the extrapolation glass transition start temperature (Tig) and the extrapolation glass transition end temperature (Teg) of 5 to 11 ° C.
　α，β－エチレン性不飽和ニトリル単量体単位（ａ）（以下、適宜、単量体単位（ａ）という）を構成するためのα，β－エチレン性不飽和ニトリル単量体としては、アクリロニトリル；α－クロロアクリロニトリル、α－ブロモアクリロニトリルなどのα－ハロゲノアクリロニトリル；メタクリロニトリル、エタクリロニトリルなどのα－アルキルアクリロニトリルなどが挙げられる。これらのなかでも、アクリロニトリルが好ましい。これらα，β－エチレン性不飽和ニトリル単量体は、一種を単独で用いてもよく、複数種を併用してもよい。 The α, β-ethylenically unsaturated nitrile monomer for constituting the α, β-ethylenically unsaturated nitrile monomer unit (a) (hereinafter, appropriately referred to as monomer unit (a)) is as follows: Examples include acrylonitrile; α-halogenoacrylonitrile such as α-chloroacrylonitrile and α-bromoacrylonitrile; and α-alkylacrylonitrile such as methacrylonitrile and ethacrylonitrile. Of these, acrylonitrile is preferred. These α, β-ethylenically unsaturated nitrile monomers may be used alone or in combination of two or more.
　ニトリル基含有高飽和共重合ゴム中のα，β－チレン性不飽和ニトリル単量体単位（ａ）の含有量は、１０～６０重量％であり、好ましくは１０～４５重量％、より好ましくは１５～４０重量％である。α，β－エチレン性不飽和ニトリル単量体単位（ａ）の含有量が少なすぎると、得られる架橋物の耐油性が低下する傾向にある。一方、多すぎると、得られる架橋物の耐寒性が低下する傾向にある。 The content of the α, β-thylene unsaturated nitrile monomer unit (a) in the nitrile group-containing highly saturated copolymer rubber is 10 to 60% by weight, preferably 10 to 45% by weight, more preferably 15 to 40% by weight. When the content of the α, β-ethylenically unsaturated nitrile monomer unit (a) is too small, the oil resistance of the resulting crosslinked product tends to be lowered. On the other hand, if the amount is too large, the cold resistance of the resulting crosslinked product tends to decrease.
　マレイン酸モノブチル単位（ｂ１）および／またはフマル酸モノブチル単位（ｂ２）（以下、適宜、単量体単位（ｂ１）、（ｂ２）という）の含有量は、０．1～２０重量％であり、好ましくは０．５～１０重量％、より好ましくは１～７重量％である。本発明においては、ニトリル基含有高飽和共重合ゴム中に、マレイン酸モノブチル単位（ｂ１）および／またはフマル酸モノブチル単位（ｂ２）を特定量含有させているため、これにより、スコーチ安定性、取り扱い性及び成形性に優れた架橋性ゴム組成物が得られ、かつ、該架橋性ゴム組成物を架橋することにより、耐寒性及び耐油性のバランスに優れた架橋物を得ることができる。マレイン酸モノブチル単位（ｂ１）および／またはフマル酸モノブチル単位（ｂ２）の含有量が少なすぎると、得られる架橋物の耐寒性が低下する傾向にある。一方、多すぎると、得られる架橋物の耐油性が低下する傾向にある。 The content of the monobutyl maleate unit (b1) and / or the monobutyl fumarate unit (b2) (hereinafter referred to as monomer units (b1) and (b2) as appropriate) is 0.1 to 20% by weight, Preferably, the content is 0.5 to 10% by weight, more preferably 1 to 7% by weight. In the present invention, the nitrile group-containing highly saturated copolymer rubber contains a specific amount of monobutyl maleate unit (b1) and / or monobutyl fumarate unit (b2). A crosslinkable rubber composition having an excellent balance between cold resistance and oil resistance can be obtained by crosslinking the crosslinkable rubber composition. When there is too little content of the monobutyl maleate unit (b1) and / or the monobutyl fumarate unit (b2), the cold resistance of the resulting crosslinked product tends to be lowered. On the other hand, if the amount is too large, the oil resistance of the resulting crosslinked product tends to decrease.
　共役ジエン単量体単位（ｃ）（以下、適宜、単量体単位（ｃ）という）を構成するための単量体としては、１，３－ブタジエン、イソプレン、２，３－ジメチル－１，３－ブタジエン、１，３－ペンタジエンなどの共役ジエンが挙げられる。これらのなかでも、１，３－ブタジエンが好ましい。なお、単量体単位（ｃ）は、共役ジエンを共重合して得られ、炭素－炭素間二重結合が残存しているものをいう。 Monomers for constituting the conjugated diene monomer unit (c) (hereinafter, appropriately referred to as monomer unit (c)) include 1,3-butadiene, isoprene, 2,3-dimethyl-1, Examples thereof include conjugated dienes such as 3-butadiene and 1,3-pentadiene. Of these, 1,3-butadiene is preferred. The monomer unit (c) is obtained by copolymerizing a conjugated diene and has a carbon-carbon double bond remaining.
　飽和化共役ジエン単量体単位（ｄ）（以下、適宜、単量体単位（ｄ）という）は、単量体単位（ｃ）の炭素－炭素間二重結合が水素添加により飽和化された構造単位および／またはα－オレフィンを共重合することによって得られる構造単位である。α－オレフィンとしては、炭素数２～１２のものが好ましく、エチレン、プロピレン、１－ブテン、４－メチル－１－ペンテン、１－ヘキセン、１－オクテンなどが挙げられる。なお、飽和化共役ジエン単量体単位（ｄ）は、共役ジエン単位の炭素－炭素間二重結合を水素添加して得られたものであることが好ましい。 In the saturated conjugated diene monomer unit (d) (hereinafter referred to as monomer unit (d) where appropriate), the carbon-carbon double bond of the monomer unit (c) was saturated by hydrogenation. A structural unit obtained by copolymerizing a structural unit and / or an α-olefin. The α-olefin preferably has 2 to 12 carbon atoms, and examples thereof include ethylene, propylene, 1-butene, 4-methyl-1-pentene, 1-hexene and 1-octene. The saturated conjugated diene monomer unit (d) is preferably obtained by hydrogenating a carbon-carbon double bond of a conjugated diene unit.
　ニトリル基含有高飽和共重合ゴム中における単量体単位（ｃ）および単量体単位（ｄ）の含有量は、単量体単位（ｃ）および単量体単位（ｄ）の合計で、２０～８９．９重量％であり、好ましくは４５～８９．５重量％、より好ましくは５３～８４重量％である。単量体単位（ｃ）と単量体単位（ｄ）との合計の含有量が少なすぎると、得られる架橋物のゴム弾性が低下する傾向にある。一方、多すぎると、得られる架橋物の耐寒性、耐油性が低下する傾向にある。 The total content of the monomer unit (c) and the monomer unit (d) in the nitrile group-containing highly saturated copolymer rubber is 20 in total as the monomer unit (c) and the monomer unit (d). -89.9% by weight, preferably 45-89.5% by weight, more preferably 53-84% by weight. If the total content of the monomer unit (c) and the monomer unit (d) is too small, the rubber elasticity of the resulting crosslinked product tends to be lowered. On the other hand, if the amount is too large, the cold resistance and oil resistance of the resulting crosslinked product tend to decrease.
　さらに、ニトリル基含有高飽和共重合ゴム中における単量体単位（ｃ）と単量体単位（ｄ）との合計の含有量を１００重量％とした場合に、この合計の含有量に対する単量体単位（ｄ）の割合は、７０重量％以上であり、好ましくは７５重量％以上、より好ましくは８０重量％以上、特に好ましくは９０重量％以上である。単量体単位（ｃ）と単量体単位（ｄ）との合計の含有量に対する単量体単位（ｄ）の割合が低すぎると（すなわち、飽和度が低すぎると）、得られる架橋物の耐熱性が低下する傾向にある。 Furthermore, when the total content of the monomer unit (c) and the monomer unit (d) in the nitrile group-containing highly saturated copolymer rubber is 100% by weight, a single amount relative to the total content The proportion of the body unit (d) is 70% by weight or more, preferably 75% by weight or more, more preferably 80% by weight or more, and particularly preferably 90% by weight or more. If the ratio of the monomer unit (d) to the total content of the monomer unit (c) and the monomer unit (d) is too low (that is, the saturation is too low), a cross-linked product is obtained. The heat resistance of the steel tends to be reduced.
　本発明のニトリル基含有高飽和共重合ゴムには、本発明の効果を損なわない範囲で、α，β－エチレン性不飽和ニトリル単量体、マレイン酸モノブチル、フマル酸モノブチル、共役ジエン及びα－オレフィン、と共重合可能なその他の単量体単位を含有することができる。その他の単量体単位を形成する単量体としては、アクリル酸メチル、メタクリル酸エチル、マレイン酸ジメチル、フマル酸ジエチルなどの、マレイン酸モノブチル及びフマル酸モノブチル以外のα，β－エチレン性不飽和カルボン酸エステル；アクリル酸、メタクリル酸、マレイン酸、フマル酸などのα，β－エチレン性不飽和カルボン酸；無水マレイン酸などのα，β－エチレン性不飽和多価カルボン酸無水物；スチレン、ビニルピリジンなどの芳香族ビニル単量体；フルオロエチルビニルエーテル、テトラフルオロエチレンなどのフッ素含有ビニル単量体；Ｎ－（４－アニリノフェニル）アクリルアミドなどの共重合性老化防止剤；などが挙げられる。これらは、一種を単独で用いてもよく、複数種類を併用してもよい。
　これらの共重合可能なその他の単量体単位の含有量は、全単量体単位１００重量％中に、好ましくは５０重量％以下、より好ましくは１０重量％以下、特に好ましくは１重量％以下である。 In the nitrile group-containing highly saturated copolymer rubber of the present invention, an α, β-ethylenically unsaturated nitrile monomer, monobutyl maleate, monobutyl fumarate, conjugated diene, and α-- are used as long as the effects of the present invention are not impaired. It may contain other monomer units copolymerizable with olefins. Other monomers that form monomer units include α, β-ethylenically unsaturated groups other than monobutyl maleate and monobutyl fumarate, such as methyl acrylate, ethyl methacrylate, dimethyl maleate, and diethyl fumarate. Carboxylic acid esters; α, β-ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and fumaric acid; α, β-ethylenically unsaturated polyvalent carboxylic acid anhydrides such as maleic anhydride; styrene, Aromatic vinyl monomers such as vinyl pyridine; fluorine-containing vinyl monomers such as fluoroethyl vinyl ether and tetrafluoroethylene; copolymerizable anti-aging agents such as N- (4-anilinophenyl) acrylamide; . These may be used individually by 1 type and may use multiple types together.
The content of these other copolymerizable monomer units is preferably 50% by weight or less, more preferably 10% by weight or less, and particularly preferably 1% by weight or less in 100% by weight of all monomer units. It is.
　本発明のニトリル基含有高飽和共重合ゴムのムーニー粘度〔ＭＬ１＋４（１００℃）〕は、１０～１００であることが好ましく、４０～１００であることがより好ましい。ニトリル基含有高飽和共重合ゴムのムーニー粘度が低すぎると、得られる架橋物の引張強さ等の機械的強度が低下する傾向にある。一方、ニトリル基含有高飽和共重合ゴムのムーニー粘度が高すぎると、加工性が低下する傾向にある。 The Mooney viscosity [ML 1 + 4 (100 ° C.)] of the nitrile group-containing highly saturated copolymer rubber of the present invention is preferably 10 to 100, and more preferably 40 to 100. When the Mooney viscosity of the nitrile group-containing highly saturated copolymer rubber is too low, mechanical strength such as tensile strength of the resulting crosslinked product tends to decrease. On the other hand, if the Mooney viscosity of the nitrile group-containing highly saturated copolymer rubber is too high, the processability tends to decrease.
　本発明のニトリル基含有高飽和共重合ゴムは、示差走査熱量測定における補外ガラス転移開始温度（Ｔｉｇ）と補外ガラス転移終了温度（Ｔｅｇ）の温度差（ΔＴ）が５～１１℃であり、好ましくは６～１０℃、より好ましくは７～１０℃、である。なお、この温度差（ΔＴ）は、ＪＩＳ Ｋ７１２１「プラスチックの転移温度測定方法」にしたがって測定することができる。この温度差（ΔＴ）を上記範囲に制御することにより、得られる架橋物の耐寒性を向上させることができる。 The nitrile group-containing highly saturated copolymer rubber of the present invention has a temperature difference (ΔT) of 5 to 11 ° C. between the extrapolated glass transition start temperature (Tig) and the extrapolated glass transition end temperature (Teg) in differential scanning calorimetry. The temperature is preferably 6 to 10 ° C, more preferably 7 to 10 ° C. The temperature difference (ΔT) can be measured in accordance with JIS K7121 “Plastic transition temperature measurement method”. By controlling this temperature difference (ΔT) within the above range, the cold resistance of the resulting crosslinked product can be improved.
　次いで、本発明のニトリル基含有高飽和共重合ゴムを製造する方法の、好適な例について説明する。
　本発明のニトリル基含有高飽和共重合ゴムは、たとえば、各単量体単位（ａ）、（ｂ１）、（ｂ２）、（ｃ）、（ｄ）を構成することとなる各単量体を含有する単量体混合物を調製し、この単量体混合物を共重合させ、得られた共重合体を選択的に水素添加することにより製造することできる。 Next, a preferred example of the method for producing the nitrile group-containing highly saturated copolymer rubber of the present invention will be described.
The nitrile group-containing highly saturated copolymer rubber of the present invention includes, for example, each monomer that constitutes each monomer unit (a), (b1), (b2), (c), (d). It can be produced by preparing a monomer mixture to be contained, copolymerizing the monomer mixture, and selectively hydrogenating the obtained copolymer.
　まず、各単量体単位（ａ）、（ｂ１）、（ｂ２）、（ｃ）、（ｄ）を構成することとなる各単量体を含有する単量体混合物を調製する。本発明においては、単量体単位（ａ）を構成することとなるα，β－エチレン性不飽和ニトリル単量体と、単量体単位（ｂ１）および／または単量体単位（ｂ２）を構成することとなるマレイン酸モノブチルおよび／またはフマル酸モノブチルと、単量体単位（ｃ）、（ｄ）を構成することとなる共役ジエン単量体とを準備し、これらを混合することにより、単量体混合物を調製する。ここで、本発明においては、マレイン酸モノブチルおよび／またはフマル酸モノブチルとしては、重合に使用するマレイン酸モノブチルおよび／またはフマル酸モノブチルのうち一部を用いて、単量体混合物を調製する。 First, a monomer mixture containing each monomer constituting each monomer unit (a), (b1), (b2), (c), (d) is prepared. In the present invention, the α, β-ethylenically unsaturated nitrile monomer constituting the monomer unit (a), the monomer unit (b1) and / or the monomer unit (b2) By preparing monobutyl maleate and / or monobutyl fumarate to be constituted and conjugated diene monomer that will constitute the monomer units (c) and (d), and mixing them, A monomer mixture is prepared. Here, in the present invention, as monobutyl maleate and / or monobutyl fumarate, a monomer mixture is prepared using a part of monobutyl maleate and / or monobutyl fumarate used for polymerization.
　そして、得られた単量体混合物を用いて共重合を行う。共重合させる方法としては、乳化重合法、懸濁重合法、塊状重合法および溶液重合法のいずれも用いることができるが、重合反応の制御の容易性等から、従来公知のゴムの製造法として一般的に用いられている常圧下での乳化重合法により重合させることが好ましい。なお、乳化重合法により共重合させる場合には、通常の方法を用いればよく、また、重合開始剤、重合停止剤、乳化剤等は一般的に用いられる従来公知のものを使用すればよい。 Then, copolymerization is performed using the obtained monomer mixture. As a copolymerization method, any of an emulsion polymerization method, a suspension polymerization method, a bulk polymerization method, and a solution polymerization method can be used. From the viewpoint of ease of control of the polymerization reaction, etc., as a conventionally known rubber production method, The polymerization is preferably carried out by a commonly used emulsion polymerization method under normal pressure. In addition, what is necessary is just to use a normal method when making it copolymerize by an emulsion polymerization method, and what is necessary is just to use the conventionally well-known thing generally used for a polymerization initiator, a polymerization terminator, an emulsifier, etc.
　本発明においては、単量体混合物の共重合の途中に、重合に使用するマレイン酸モノブチルおよび／またはフマル酸モノブチルのうちの残部を添加する。すなわち、本発明においては、共重合に供する単量体混合物中に、重合に使用するマレイン酸モノブチルおよび／またはフマル酸モノブチルのうちの一部のみを、添加した状態で共重合を開始させ、これらのうち残部については、共重合の途中で追加添加するという方法を採用する。そして、このような方法を採用することにより、示差走査熱量測定における補外ガラス転移開始温度（Ｔｉｇ）と補外ガラス転移終了温度（Ｔｅｇ）の温度差（ΔＴ）を上記範囲に制御することができる。 In the present invention, the remainder of monobutyl maleate and / or monobutyl fumarate used for polymerization is added during the copolymerization of the monomer mixture. That is, in the present invention, the copolymerization is started in a state where only a part of monobutyl maleate and / or monobutyl fumarate used for the polymerization is added to the monomer mixture used for the copolymerization. Among these, the method of adding the remainder in the middle of copolymerization is employ | adopted. By adopting such a method, the temperature difference (ΔT) between the extrapolation glass transition start temperature (Tig) and the extrapolation glass transition end temperature (Teg) in the differential scanning calorimetry can be controlled within the above range. it can.
　なお、予め単量体混合物中に含有させるマレイン酸モノブチルおよび／またはフマル酸モノブチルと、共重合の途中で追加添加するマレイン酸モノブチルおよび／またはフマル酸モノブチルと、の合計を１００重量％とした場合に、これらの合計に対する、予め単量体混合物中に含有させるマレイン酸モノブチルおよび／またはフマル酸モノブチルの割合は、好ましくは１０～９０重量％であり、より好ましくは２０～８０重量％、さらに好ましくは４０～７０重量％である。また、共重合の途中で追加添加するマレイン酸モノブチルおよび／またはフマル酸モノブチルの割合は、好ましくは１０～９０重量％であり、より好ましくは２０～８０重量％、さらに好ましくは３０～６０重量％である。共重合の途中で追加添加するマレイン酸モノブチルおよび／またはフマル酸モノブチルの割合が低すぎても、また、高すぎても、補外ガラス転移開始温度（Ｔｅｇ）が高くなってしまい、結果として、温度差（ΔＴ）が大きくなり過ぎてしまう。 When the total of monobutyl maleate and / or monobutyl fumarate previously added in the monomer mixture and monobutyl maleate and / or monobutyl fumarate added during the copolymerization is 100% by weight In addition, the ratio of monobutyl maleate and / or monobutyl fumarate previously contained in the monomer mixture with respect to the total of these is preferably 10 to 90% by weight, more preferably 20 to 80% by weight, still more preferably Is 40 to 70% by weight. The proportion of monobutyl maleate and / or monobutyl fumarate added during the copolymerization is preferably 10 to 90% by weight, more preferably 20 to 80% by weight, still more preferably 30 to 60% by weight. It is. If the proportion of monobutyl maleate and / or monobutyl fumarate added during the copolymerization is too low or too high, the extrapolated glass transition start temperature (Teg) becomes high, and as a result, The temperature difference (ΔT) becomes too large.
　また、共重合の途中で追加添加するマレイン酸モノブチルおよび／またはフマル酸モノブチルの添加時期としては、特に限定されないが、単量体混合物の共重合が開始し、重合転化率が好ましくは１０～７５％、より好ましくは１５～７０％、さらに好ましくは２０～６５％となった時点とすることが好ましい。 Further, the addition time of monobutyl maleate and / or monobutyl fumarate to be additionally added during the copolymerization is not particularly limited, but the copolymerization of the monomer mixture starts, and the polymerization conversion rate is preferably 10 to 75. %, More preferably 15 to 70%, still more preferably 20 to 65%.
　さらに、マレイン酸モノブチルおよび／またはフマル酸モノブチルを共重合の途中で追加添加する際には、複数回に分けて添加することが、上記温度差（ΔＴ）を所定の範囲に制御し易いため、好ましい。たとえば、２回に分けて添加する場合には、重合転化率が好ましくは１０％以上、５０％未満となった時点で１回目の添加を行い、重合転化率が好ましくは５０～７５％となった時点で２回目の添加を行うことが好ましい。 Furthermore, when additional addition of monobutyl maleate and / or monobutyl fumarate in the middle of the copolymerization, it is easy to control the temperature difference (ΔT) within a predetermined range by adding in multiple times, preferable. For example, in the case of adding in two portions, the first addition is performed when the polymerization conversion rate is preferably 10% or more and less than 50%, and the polymerization conversion rate is preferably 50 to 75%. It is preferable to perform the second addition at this point.
　そして、得られた共重合体に対して、選択的に水素添加することにより、本発明のニトリル基含有高飽和共重合ゴムを製造することができる。なお、水素添加に用いる水素添加触媒の種類と量、水素添加温度などは、公知の方法に準じて決めればよい。 The nitrile group-containing highly saturated copolymer rubber of the present invention can be produced by selectively hydrogenating the obtained copolymer. The type and amount of the hydrogenation catalyst used for hydrogenation, the hydrogenation temperature, etc. may be determined according to known methods.
　架橋性ゴム組成物
　本発明の架橋性ゴム組成物は、上記ニトリル基含有高飽和共重合ゴムと、架橋剤と、を含有してなるものである。 Crosslinkable rubber composition The crosslinkable rubber composition of the present invention comprises the above nitrile group-containing highly saturated copolymer rubber and a crosslinking agent.
　架橋剤としては、ポリアミン化合物、有機過酸化物、多価エポキシ化合物、多価イソシアナート化合物、アジリジン化合物、硫黄化合物、塩基性金属酸化物および有機金属ハロゲン化物などのゴムの架橋に通常用いられる従来公知の架橋剤を用いることができる。なかでもポリアミン化合物および有機過酸化物が好ましく、機械的特性に優れ、圧縮永久ひずみが小さいゴム架橋物が得られ易いことから、ポリアミン化合物（以下、「ポリアミン系架橋剤」という。）がより好ましい。 As a crosslinking agent, conventionally used for crosslinking rubber such as polyamine compounds, organic peroxides, polyvalent epoxy compounds, polyvalent isocyanate compounds, aziridine compounds, sulfur compounds, basic metal oxides and organometallic halides. A known crosslinking agent can be used. Among them, polyamine compounds and organic peroxides are preferable, and a polyamine compound (hereinafter referred to as “polyamine-based cross-linking agent”) is more preferable because a rubber cross-linked product having excellent mechanical properties and low compression set is easily obtained. .
　ポリアミン系架橋剤としては、（１）２つ以上のアミノ基を有する化合物、または（２）架橋時に２つ以上のアミノ基を有する化合物の形態になるもの、であれば特に限定されないが、脂肪族炭化水素や芳香族炭化水素の複数の水素原子が、アミノ基またはヒドラジド構造（－ＣＯＮＨＮＨ２で表される構造、ＣＯはカルボニル基を表す。）で置換された化合物が好ましい。その具体例として、ヘキサメチレンジアミン、ヘキサメチレンジアミンカルバメート、テトラメチレンペンタミン、ヘキサメチレンジアミンシンナムアルデヒド付加物、ヘキサメチレンジアミンジベンゾエート塩などの脂肪族多価アミン類；２，２－ビス｛４－（４－アミノフェノキシ）フェニル｝プロパン、４，４’－メチレンジアニリン、ｍ－フェニレンジアミン、ｐ－フェニレンジアミン、４，４’－メチレンビス（ｏ－クロロアニリン）などの芳香族多価アミン類；イソフタル酸ジヒドラジド、アジピン酸ジヒドラジド、セバシン酸ジヒドラジドなどのヒドラジド構造を２つ以上有する化合物；などが挙げられるが、ヘキサメチレンジアミンカルバメートが特に好ましい。 The polyamine-based crosslinking agent is not particularly limited as long as it is (1) a compound having two or more amino groups, or (2) a compound having two or more amino groups at the time of crosslinking. A compound in which a plurality of hydrogen atoms of an aromatic hydrocarbon or aromatic hydrocarbon are substituted with an amino group or a hydrazide structure (a structure represented by —CONHNH 2 , CO represents a carbonyl group) is preferable. Specific examples thereof include aliphatic polyvalent amines such as hexamethylenediamine, hexamethylenediamine carbamate, tetramethylenepentamine, hexamethylenediamine cinnamaldehyde adduct, hexamethylenediamine dibenzoate salt; 2,2-bis {4- Aromatic polyamines such as (4-aminophenoxy) phenyl} propane, 4,4′-methylenedianiline, m-phenylenediamine, p-phenylenediamine, 4,4′-methylenebis (o-chloroaniline); Compounds having two or more hydrazide structures such as isophthalic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, and the like are mentioned, and hexamethylenediamine carbamate is particularly preferable.
　本発明の架橋性ゴム組成物中における架橋剤の含有量は、ニトリル基含有高飽和共重合ゴム１００重量部に対し、好ましくは０．２～２０重量部、より好ましくは１～１５重量部、特に好ましくは１．５～１０重量部である。架橋剤の含有量が少なすぎると、引張応力に優れ、圧縮永久ひずみが小さいゴム架橋物が得られにくいおそれがあり、逆に、多すぎるとゴム架橋物の耐屈曲疲労性が低下する可能性がある。 The content of the crosslinking agent in the crosslinkable rubber composition of the present invention is preferably 0.2 to 20 parts by weight, more preferably 1 to 15 parts by weight with respect to 100 parts by weight of the nitrile group-containing highly saturated copolymer rubber. Particularly preferred is 1.5 to 10 parts by weight. If the content of the crosslinking agent is too small, it may be difficult to obtain a rubber cross-linked product having excellent tensile stress and low compression set. Conversely, if it is too high, the bending fatigue resistance of the rubber cross-linked product may be reduced. There is.
　本発明の架橋性ゴム組成物には、上記ニトリル基含有高飽和共重合ゴム、および架橋剤以外に、ゴム加工分野において通常使用される配合剤、例えば、架橋促進剤、架橋助剤、架橋遅延剤、補強性充填材（カーボンブラック、シリカなど）、非補強性充填材（炭酸カルシウム、クレーなど）、老化防止剤、酸化防止剤、光安定剤、一級アミンなどのスコーチ防止剤、可塑剤、加工助剤、滑剤、粘着剤、潤滑剤、難燃剤、防黴剤、受酸剤、帯電防止剤、着色剤などを配合することができる。これらの配合剤の配合量は、本発明の効果を阻害しない範囲であれば特に限定されず、配合目的に応じた量を適宜配合することができる。 In addition to the nitrile group-containing highly saturated copolymer rubber and the crosslinking agent, the crosslinkable rubber composition of the present invention contains a compounding agent usually used in the rubber processing field, for example, a crosslinking accelerator, a crosslinking aid, a crosslinking delay. Agent, reinforcing filler (carbon black, silica, etc.), non-reinforcing filler (calcium carbonate, clay, etc.), anti-aging agent, antioxidant, light stabilizer, primary amine scorch inhibitor, plasticizer, Processing aids, lubricants, adhesives, lubricants, flame retardants, antifungal agents, acid acceptors, antistatic agents, colorants, and the like can be blended. The compounding amount of these compounding agents is not particularly limited as long as the effect of the present invention is not impaired, and an amount corresponding to the compounding purpose can be appropriately compounded.
　本発明の架橋性ゴム組成物には、本発明の効果を阻害しない範囲で、上述した本発明のニトリル基含有高飽和共重合ゴム以外のゴムを配合してもよい。本発明のニトリル基含有高飽和共重合ゴム以外のゴムの配合量は、本発明のニトリル基含有高飽和共重合ゴム１００重量部に対して、通常、３０重量部以下、好ましくは２０重量部以下、より好ましくは１０重量部以下である。
　このようなゴムとしては、アクリルゴム、エチレン－アクリル酸共重合体ゴム、スチレン－ブタジエン共重合体ゴム、アクリロニトリル－ブタジエン共重合ゴム（水素化物を除く）、ポリブタジエンゴム、エチレン－プロピレン共重合体ゴム、エチレン－プロピレン－ジエン三元共重合体ゴム、エピクロロヒドリンゴム、ウレタンゴム、クロロプレンゴム、シリコーンゴム、フッ素ゴム、天然ゴム、ポリイソプレンゴムなどが挙げられる。
　また、水素化していないアクリロニトリル－ブタジエン共重合ゴムのような不飽和度の高いニトリル基含有共重合ゴムを配合する場合に、その配合量が多すぎると、得られる架橋物の耐空気加熱老化性、耐屈曲疲労性、伸び、が低下し、圧縮永久ひずみが増大する傾向にある。
　なお、本発明のニトリル基含有高飽和共重合ゴム以外のゴムを配合する場合は、それらのゴムを架橋できる架橋剤を必要量加えてもよい。 In the crosslinkable rubber composition of the present invention, a rubber other than the nitrile group-containing highly saturated copolymer rubber of the present invention described above may be blended as long as the effects of the present invention are not impaired. The amount of rubber other than the nitrile group-containing highly saturated copolymer rubber of the present invention is usually 30 parts by weight or less, preferably 20 parts by weight or less, based on 100 parts by weight of the nitrile group-containing highly saturated copolymer rubber of the present invention. More preferably, it is 10 parts by weight or less.
Examples of such rubbers include acrylic rubber, ethylene-acrylic acid copolymer rubber, styrene-butadiene copolymer rubber, acrylonitrile-butadiene copolymer rubber (excluding hydride), polybutadiene rubber, and ethylene-propylene copolymer rubber. Ethylene-propylene-diene terpolymer rubber, epichlorohydrin rubber, urethane rubber, chloroprene rubber, silicone rubber, fluorine rubber, natural rubber, polyisoprene rubber and the like.
In addition, when blending a nitrile group-containing copolymer rubber having a high degree of unsaturation such as an unhydrogenated acrylonitrile-butadiene copolymer rubber, if the blending amount is too large, the resulting crosslinked product is resistant to air heat aging. , Bending fatigue resistance and elongation tend to decrease, and compression set tends to increase.
In addition, when mix | blending rubber | gum other than the nitrile group containing highly saturated copolymer rubber of this invention, you may add required amount of crosslinking agents which can bridge | crosslink those rubber | gum.
　本発明の架橋性ゴム組成物は、他のゴム組成物と同様に一般的なゴム組成物の調製方法で調製すればよく、密閉式混合機やオープンロールなどを用いて混練すればよい。架橋剤や架橋助剤を配合する際に、架橋剤や架橋助剤の配合以降は、混練中に架橋しないように、架橋開始温度以下になるように温度調整をするのも一般的な架橋性ゴム組成物の調製方法と同様であり、通常は、架橋剤、架橋助剤などを含有しないゴム組成物を調製した後、これらの架橋に関わる成分をそれらに応じた架橋開始温度未満で配合し、混合すればよい。 The crosslinkable rubber composition of the present invention may be prepared by a general method for preparing a rubber composition in the same manner as other rubber compositions, and may be kneaded using a closed mixer or an open roll. When blending a crosslinking agent or crosslinking aid, it is also common to adjust the temperature so that it does not crosslink during kneading after the blending of the crosslinking agent or crosslinking aid so that it is below the crosslinking start temperature. This is the same as the method for preparing a rubber composition. Usually, after preparing a rubber composition containing no crosslinking agent, crosslinking aid, etc., these crosslinking-related components are blended at a temperature lower than the crosslinking initiation temperature corresponding to them. , Mix.
　架橋物
　本発明の架橋物は、上述した本発明の架橋性ゴム組成物を架橋することにより得られるものである。 Cross-linked product The cross-linked product of the present invention is obtained by cross-linking the cross-linkable rubber composition of the present invention described above.
　架橋性ゴム組成物を架橋する方法は、特に限定されないが、架橋時の温度は、１００～２００℃とすることが好ましく、より好ましくは１３０～１８０℃である。架橋時の温度が低すぎると、架橋時間が長時間必要となったり、得られる架橋物の架橋密度が低くなったりする場合がある。架橋時の温度が高すぎると、成形不良となる場合がある。 The method for crosslinking the crosslinkable rubber composition is not particularly limited, but the temperature during crosslinking is preferably 100 to 200 ° C, more preferably 130 to 180 ° C. If the temperature at the time of crosslinking is too low, the crosslinking time may be required for a long time, or the crosslinking density of the resulting crosslinked product may be lowered. If the temperature at the time of crosslinking is too high, molding failure may occur.
　また、架橋時間は、架橋方法、架橋温度、架橋物の形状などにより異なるが、得られる架橋物の架橋密度や生産効率の面より、１分以上、５時間以下の範囲が好ましい。架橋のための加熱方法としては、プレス加熱、蒸気加熱、オーブン加熱、熱風加熱などのゴムの架橋に通常用いられる方法から適宜選択すればよい。 The crosslinking time varies depending on the crosslinking method, the crosslinking temperature, the shape of the crosslinked product, etc., but is preferably in the range of 1 minute or more and 5 hours or less from the viewpoint of the crosslinking density and production efficiency of the obtained crosslinked product. The heating method for crosslinking may be appropriately selected from methods usually used for rubber crosslinking such as press heating, steam heating, oven heating, and hot air heating.
　このようにして得られる本発明の架橋物は、上述した本発明のニトリル基含有高飽和共重合ゴムを用いて得られるものであるため、耐油性および耐寒性に優れ、圧縮永久ひずみ、特にＯ－リング形状の成形体とした場合における圧縮永久ひずみ（Ｏ－リング圧縮永久ひずみ）が小さいという特性を有するものである。 The cross-linked product of the present invention thus obtained is obtained by using the nitrile group-containing highly saturated copolymer rubber of the present invention described above, and therefore has excellent oil resistance and cold resistance, compression set, particularly O -It has a characteristic that the compression set (O-ring compression set) in the case of a ring-shaped molded product is small.
　そして、このような本発明の架橋物は、その特性を活かして、Ｏ－リング、パッキン、ダイアフラム、オイルシール、シャフトシール、ベアリングシール、メカニカルシール、ウェルヘッドシール、電気・電子機器用シール、空気圧機器用シール、エアコンディショナの冷却装置や空調装置の冷凍機用コンプレッサに使用されるフロン若しくはフルオロ炭化水素または二酸化炭素の密封用シール、精密洗浄の洗浄媒体に使用される超臨界二酸化炭素または亜臨界二酸化炭素の密封用シール、転動装置(転がり軸受、自動車用ハブユニット、自動車用ウォーターポンプ、リニアガイド装置およびボールねじ等)用のシール、バルブおよびバルブシート、ＢＯＰ（Ｂｌｏｗ　Ｏｕｔ　Ｐｒｅｖｅｎｔａｒ）、プラターなどの各種シール用ゴム部材；および、インテークマニホールドとシリンダヘッドとの連接部に装着されるインテークマニホールドガスケット、シリンダブロックとシリンダヘッドとの連接部に装着されるシリンダヘッドガスケット、ロッカーカバーとシリンダヘッドとの連接部に装着されるロッカーカバーガスケット、オイルパンとシリンダブロックあるいはトランスミッションケースとの連接部に装着されるオイルパンガスケット、正極、電解質板および負極を備えた単位セルを挟み込む一対のハウジング間に装着される燃料電池セパレーター用ガスケット、ハードディスクドライブのトップカバー用ガスケットなどの各種ガスケット；として好適に用いられる。
　また、本発明のゴム架橋物は、印刷用ロール、製鉄用ロール、製紙用ロール、工業用ロール、事務機用ロールなどの各種ロール；平ベルト（フィルムコア平ベルト、コード平ベルト、積層式平ベルト、単体式平ベルト等）、Ｖベルト（ラップドＶベルト、ローエッジＶベルト等）、Ｖリブドベルト（シングルＶリブドベルト、ダブルＶリブドベルト、ラップドＶリブドベルト、背面ゴムＶリブドベルト、上コグＶリブドベルト等）、ＣＶＴ用ベルト、タイミングベルト、歯付ベルト、コンベアーベルト、などの各種ベルト；燃料ホース、ターボエアーホース、オイルホース、ラジェターホース、ヒーターホース、ウォーターホース、バキュームブレーキホース、コントロールホース、エアコンホース、ブレーキホース、パワーステアリングホース、エアーホース、マリンホース、ライザー、フローラインなどの各種ホース；ＣＶＪブーツ、プロペラシャフトブーツ、等速ジョイントブーツ、ラックアンドピニオンブーツなどの各種ブーツ；クッション材、ダイナミックダンパ、ゴムカップリング、空気バネ、防振材などの減衰材ゴム部品；ダストカバー、自動車内装部材、タイヤ、被覆ケーブル、靴底、電磁波シールド、フレキシブルプリント基板用接着剤等の接着剤、燃料電池セパレーターの他、化粧品、および医薬品の分野、食品と接触する分野、エレクトロニクス分野など幅広い用途に使用することもできる。 Such a cross-linked product of the present invention makes use of its characteristics to provide O-rings, packings, diaphragms, oil seals, shaft seals, bearing seals, mechanical seals, well head seals, electrical / electronic device seals, pneumatic pressure Equipment seals, chlorofluorocarbon or fluorohydrocarbon or carbon dioxide sealing seals used in air conditioner cooling devices or air conditioner refrigerator compressors, supercritical carbon dioxide or sublimation used in cleaning media for precision cleaning Seals for sealing critical carbon dioxide, seals for rolling devices (rolling bearings, automotive hub units, automotive water pumps, linear guide devices, ball screws, etc.), valves and valve seats, BOP (Blow Out Preventar), platters Rubber members for various seals such as Intake manifold gaskets attached to the connecting portion between the intake manifold and the cylinder head, cylinder head gaskets attached to the connecting portion between the cylinder block and the cylinder head, and rockers attached to the connecting portion between the rocker cover and the cylinder head A cover gasket, an oil pan gasket attached to a connecting portion between an oil pan and a cylinder block or a transmission case, a fuel cell separator gasket attached between a pair of housings sandwiching a unit cell having a positive electrode, an electrolyte plate, and a negative electrode; It is suitably used as various gaskets such as a hard disk drive top cover gasket.
Further, the rubber cross-linked product of the present invention includes various rolls such as a printing roll, a steel roll, a paper roll, an industrial roll, and an office machine roll; a flat belt (film core flat belt, cord flat belt, laminated flat belt). Belts, single unit flat belts, etc.), V belts (wrapped V belts, low edge V belts, etc.), V ribbed belts (single V ribbed belt, double V ribbed belt, wrapped V ribbed belt, back rubber V ribbed belt, upper cog V ribbed belt, etc.), CVT Belts such as belts, timing belts, toothed belts, conveyor belts, fuel hoses, turbo air hoses, oil hoses, radiator hoses, heater hoses, water hoses, vacuum brake hoses, control hoses, air conditioning hoses, brake hoses, Power steering ho Various hoses such as springs, air hoses, marine hoses, risers, flow lines; various boots such as CVJ boots, propeller shaft boots, constant velocity joint boots, rack and pinion boots; cushion materials, dynamic dampers, rubber couplings, air springs Damping material rubber parts such as anti-vibration materials; dust covers, automotive interior parts, tires, coated cables, shoe soles, electromagnetic wave shields, adhesives for flexible printed circuit boards, fuel cell separators, cosmetics, and pharmaceuticals It can also be used for a wide range of applications, such as the field of contact with food, the field of contact with food, and the field of electronics.
　以下、本発明を、さらに詳細な実施例に基づき説明するが、本発明は、これら実施例に限定されない。本実施例における「部」は、特記しない限り重量基準である。なお、試験、評価は下記によった。 Hereinafter, the present invention will be described based on more detailed examples, but the present invention is not limited to these examples. “Parts” in this example are based on weight unless otherwise specified. The test and evaluation were as follows.
　ガラス転移温度
　ニトリル基含有高飽和共重合ゴムについて、ＪＩＳ Ｋ７１２１にしたがい、熱流束示差走査熱量測定を行い、補外ガラス転移開始温度（Ｔｉｇ）および補外ガラス転移終了温度（Ｔｅｇ）を測定した。本実施例においては、測定精度を高めるために、加熱速度を毎分２０℃から毎分１０℃に変更して測定した。なお、ΔＴは、ＴｅｇとＴｉｇとの差の絶対値である。 Glass transition temperature Nitrile group-containing highly saturated copolymer rubber was subjected to heat flux differential scanning calorimetry in accordance with JIS K7121, and extrapolated glass transition start temperature (Tig) and extrapolated glass transition end temperature (Teg). In this example, in order to increase the measurement accuracy, the heating rate was changed from 20 ° C./min to 10 ° C./min. ΔT is the absolute value of the difference between Teg and Tig.
　ムーニー粘度（ポリマームーニー）
　ニトリル基含有高飽和共重合ゴムのムーニー粘度（ポリマームーニー、〔ＭＬ１＋４（１００℃）〕）を、ＪＩＳ　Ｋ６３００－１に従って測定した。 Mooney viscosity (Polymer Mooney)
The Mooney viscosity (polymer Mooney, [ML 1 + 4 (100 ° C.)]) of the highly saturated copolymer rubber containing nitrile group was measured according to JIS K6300-1.
　常態物性（引張強さ、伸び、硬さ）
　縦１５ｃｍ、横１５ｃｍ、深さ０．２ｃｍの金型を用いて、架橋性ゴム組成物を、加圧しながら１７０℃で２０分間プレス成形することにより、シート状架橋物を得て、これをギヤー式オーブンにて１７０℃、４時間の条件で、二次架橋させることにより、厚さ２ｍｍの架橋物のシートを得た。次いで、得られた架橋物のシートを、３号形ダンベルを用いて打ち抜くことにより、シート状の試験片を作製した。そして、得られたシート状の試験片を用いて、ＪＩＳ Ｋ６２５１に従い、架橋物の引張強さ、および伸びを測定し、ＪＩＳ Ｋ６２５３に従い、デュロメータ硬さ試験機タイプＡ形を用いて架橋物の硬さを測定した。 Normal physical properties (tensile strength, elongation, hardness)
Using a mold having a length of 15 cm, a width of 15 cm, and a depth of 0.2 cm, a crosslinkable rubber composition is press-molded at 170 ° C. for 20 minutes while being pressed to obtain a sheet-like cross-linked product, which is then used as a gear. By carrying out secondary crosslinking under the conditions of 170 ° C. and 4 hours in a type oven, a crosslinked sheet having a thickness of 2 mm was obtained. Subsequently, the obtained cross-linked sheet was punched out using a No. 3 type dumbbell to prepare a sheet-like test piece. Then, using the obtained sheet-like test piece, the tensile strength and elongation of the crosslinked product are measured according to JIS K6251, and the hardness of the crosslinked product is measured using a durometer hardness tester type A according to JIS K6253. Was measured.
　耐寒性（ゲーマンねじり試験）
　ゴム架橋物の耐寒性は、ＪＩＳ　Ｋ　６２６１に従い、Ｔ１０（℃）を測定することにより評価した。Ｔ１０の温度が低いほど耐寒性に優れると判断される。 Cold resistance (Geman torsion test)
The cold resistance of the rubber cross-linked product was evaluated by measuring T 10 (° C.) according to JIS K 6261. The temperature of the T 10 is determined to excellent low enough cold resistance.
　Ｄｉｓｋ圧縮永久ひずみ（Ｄｉｓｋセット試験）
　内径２９ｍｍ、深さ１２．５ｍｍの金型を用いて、架橋性ゴム組成物について、加圧しながら１７０℃で２０分間プレス成形することにより、シート状架橋物を得て、これをギヤー式オーブンにて１７０℃、４時間にて、二次架橋を行うことによりＤｉｓｋセット試験用の試験片を得た。そして、得られた試験片を用いて、２５％圧縮した状態で、１５０℃にて１６８時間保持の条件でＪＩＳ　Ｋ６２６２にしたがって、Ｄｉｓｋ圧縮永久ひずみを測定した。 Disk compression set (Disk set test)
Using a mold having an inner diameter of 29 mm and a depth of 12.5 mm, the crosslinkable rubber composition is press-molded at 170 ° C. for 20 minutes while being pressurized to obtain a sheet-like cross-linked product, which is put into a gear-type oven. A test piece for a disk set test was obtained by performing secondary crosslinking at 170 ° C. for 4 hours. And the disk compression set was measured according to JISK6262 on the conditions hold | maintained at 150 degreeC for 168 hours in the state compressed 25% using the obtained test piece.
　Ｏ－リング圧縮永久ひずみ（Ｏ－リングセット試験）
　内径３０ｍｍ、リング径３ｍｍの金型を用いて、架橋性ゴム組成物について、加圧しながら１７０℃で２０分間プレス成形することにより、リング状架橋物を得て、これをギヤー式オーブンにて１７０℃、４時間にて、二次架橋を行うことによりＯ－リングセット試験用の試験片を得た。そして、得られた試験片を用いて、Ｏ－リングを挟んだ二つの平面の距離をリング厚み方向に２５％圧縮した状態で１５０℃にて１６８時間保持の条件、および１５０℃にて５０４時間保持の条件の２条件で、ＪＩＳ　Ｋ６２６２にしたがって、Ｏ－リング圧縮永久ひずみを測定した。 O-ring compression set (O-ring set test)
Using a mold having an inner diameter of 30 mm and a ring diameter of 3 mm, the cross-linkable rubber composition is press-molded at 170 ° C. for 20 minutes while being pressurized to obtain a ring-shaped cross-linked product, which is 170 in a gear-type oven. A test piece for an O-ring set test was obtained by performing secondary crosslinking at 4 ° C. for 4 hours. Then, using the obtained test piece, the distance between the two planes sandwiching the O-ring was compressed by 25% in the ring thickness direction and maintained at 150 ° C. for 168 hours, and at 150 ° C. for 504 hours. The O-ring compression set was measured in accordance with JIS K6262 under the two conditions of holding.
　実施例１
　反応器に、イオン交換水１８０部、濃度１０重量％のドデシルベンゼンスルホン酸ナトリウム水溶液２５部、アクリロニトリル３７部、マレイン酸モノｎ－ブチル３部、ｔ－ドデシルメルカプタン（分子量調整剤）０．５部の順に仕込み、内部の気体を窒素で３回置換した後、１，３－ブタジエン５７部を仕込んだ。反応器を５℃に保ち、クメンハイドロパーオキサイド（重合開始剤）０．１部を仕込み、攪拌しながら重合反応を継続し、途中重合転化率が４０％、及び６０％になった時点で、それぞれ１．５部のマレイン酸モノｎ－ブチルを添加し１６時間重合反応を継続した。濃度１０重量％のハイドドキノン水溶液（重合停止剤）０．１部を加えて重合反応を停止した後、水温６０℃のロータリーエバポレータを用いて残留単量体を除去し、アクリロニトリル－ブタジエン－マレイン酸モノｎ－ブチル共重合ゴムラテックス（固形分濃度約３０重量％）を得た。 Example 1
In a reactor, 180 parts of ion-exchanged water, 25 parts of a 10% strength by weight sodium dodecylbenzenesulfonate aqueous solution, 37 parts of acrylonitrile, 3 parts of mono-n-butyl maleate, 0.5 part of t-dodecyl mercaptan (molecular weight regulator) In this order, the internal gas was replaced with nitrogen three times, and then 57 parts of 1,3-butadiene was charged. Maintaining the reactor at 5 ° C., charging 0.1 parts of cumene hydroperoxide (polymerization initiator), continuing the polymerization reaction while stirring, and when the polymerization conversion rate reached 40% and 60% during the process, 1.5 parts of mono-n-butyl maleate was added to each, and the polymerization reaction was continued for 16 hours. The polymerization reaction was stopped by adding 0.1 part of a 10% strength by weight aqueous solution of hydridoquinone (polymerization terminator), then the residual monomer was removed using a rotary evaporator at a water temperature of 60 ° C., and acrylonitrile-butadiene-maleic acid mono An n-butyl copolymer rubber latex (solid content concentration of about 30% by weight) was obtained.
　得られた共重合ゴムラテックスについて、該ラテックスに含有される乾燥ゴム重量に対してパラジウム含有量が１０００ｐｐｍになるようにオートクレーブにパラジウム触媒（１重量％酢酸パラジウムアセトン溶液と等重量のイオン交換水を混合した溶液）を添加して、水素圧３ＭＰａ、温度５０℃で６時間水素添加反応を行い、ニトリル基含有高飽和共重合ゴムラテックスを得た。
　得られたニトリル基含有高飽和共重合ゴムラテックスに２倍容量のメタノールを加えて、ニトリル基含有高飽和共重合ゴムを凝固した後、６０℃で１２時間真空乾燥してニトリル基含有高飽和共重合ゴムを得た。 About the obtained copolymer rubber latex, a palladium catalyst (ion exchange water equal in weight to 1 wt% palladium acetate acetone solution) was added to the autoclave so that the palladium content was 1000 ppm with respect to the dry rubber weight contained in the latex. The mixed solution was added and a hydrogenation reaction was performed at a hydrogen pressure of 3 MPa and a temperature of 50 ° C. for 6 hours to obtain a nitrile group-containing highly saturated copolymer rubber latex.
The resulting nitrile group-containing highly saturated copolymer rubber latex was added with twice the volume of methanol to coagulate the nitrile group-containing highly saturated copolymer rubber, and then vacuum dried at 60 ° C. for 12 hours to obtain a nitrile group-containing highly saturated copolymer rubber. A polymer rubber was obtained.
　得られたニトリル基含有高飽和共重合ゴムの全重合体中における、各単量体単位の含有割合および物性を表１に示す。なお、ニトリル基含有高飽和共重合ゴム中の単量体単位の含有割合は、１Ｈ－ＮＭＲに基づいて求めた値である。 Table 1 shows the content and physical properties of each monomer unit in the entire polymer of the obtained nitrile group-containing highly saturated copolymer rubber. The content ratio of the monomer unit in the nitrile group-containing highly saturated copolymer rubber is a value determined based on 1 H-NMR.
　次いで、バンバリーミキサを用いて上記にて調製したニトリル基含有高飽和共重合ゴム１００部に、ＦＥＦカーボンブラック（旭６０、旭カーボン社製）４０部、トリメリット酸エステル（アデカサイザーＣ－８、旭電化社製、可塑剤）５部、ステアリン酸（架橋促進助剤）１部、４，４’－ジ－（α，α’－ジメチルベンジル）ジフェニルアミン（ナウガード４４５、Ｃｒｏｍｐｔｏｎ社製、老化防止剤）１．５部、および、２－メルカプトベンズイミダゾール（ノクラックＭＢ、大内新興社製、老化防止剤）１．５部を添加して混合し、次いで、混合物をロールに移して１，３－ジ－ｏ－トリルグアニジン（ノクセラーＤＴ、大内新興社製、架橋促進剤）２部、および、ヘキサメチレンジアミンカルバメート（Ｄｉａｋ＃１、デュポンダウエラストマー社製、架橋剤）２．５部を添加して混練し、架橋性ニトリルゴム組成物を調製した。そして、得られた架橋性ゴム組成物を用いて、上記方法にしたがい、架橋物を作製し、常態物性、耐寒性、Ｄｉｓｋ圧縮永久ひずみ、およびＯ－リング圧縮永久ひずみの各評価を行った。結果を表１に示す。 Subsequently, 40 parts of FEF carbon black (Asahi 60, manufactured by Asahi Carbon Co., Ltd.), trimellitic acid ester (Adekasizer C-8, Asahi Denka Co., Ltd., plasticizer) 5 parts, stearic acid (crosslinking accelerator) 1 part, 4,4′-di- (α, α′-dimethylbenzyl) diphenylamine (Naugard 445, Crompton, anti-aging agent) ) 1.5 parts and 1.5 parts of 2-mercaptobenzimidazole (NOCRACK MB, manufactured by Ouchi Shinsei Co., Ltd., anti-aging agent) are added and mixed, then the mixture is transferred to a roll and 1,3- 2 parts of di-o-tolylguanidine (Noxeller DT, manufactured by Ouchi Shinsei Co., Ltd., crosslinking accelerator) and hexamethylenediamine carbamate (Diak # 1, Duponder) 2.5 parts of a crosslinker manufactured by Elastomer Co., Ltd. was added and kneaded to prepare a crosslinkable nitrile rubber composition. Then, using the obtained crosslinkable rubber composition, a crosslinked product was produced in accordance with the above method, and each of normal properties, cold resistance, Disk compression set, and O-ring compression set was evaluated. The results are shown in Table 1.
　実施例２
　重合開始時に用いるマレイン酸モノｎ－ブチルの量を２部とし、マレイン酸モノｎ－ブチルの中途添加の時期および量を、重合転化率４０％となった時点で２部、重合転化率６０％となった時点でさらに２部とした以外は、実施例１と同様にして、表１に示す組成を有するニトリル基含有高飽和共重合ゴムを調製し、同様にして架橋物を得て、各評価を行った。結果を表１に示す。 Example 2
The amount of mono n-butyl maleate used at the start of the polymerization was 2 parts, and the timing and amount of the middle addition of mono n-butyl maleate were 2 parts when the polymerization conversion was 40%, and the polymerization conversion was 60%. A nitrile group-containing highly saturated copolymer rubber having the composition shown in Table 1 was prepared in the same manner as in Example 1 except that the amount was further 2 parts. Evaluation was performed. The results are shown in Table 1.
　比較例１
　重合開始時に用いるマレイン酸モノｎ－ブチルの量を６部とし、マレイン酸モノブチルの中途添加を行わなかった以外は、実施例１と同様にして、表１に示す組成を有するニトリル基含有高飽和共重合ゴムを調製し、同様にして架橋物を得て、各評価を行った。結果を表１に示す。 Comparative Example 1
A nitrile group-containing highly saturated composition having the composition shown in Table 1 was used in the same manner as in Example 1 except that the amount of mono-n-butyl maleate used at the start of the polymerization was 6 parts and no monobutyl maleate was added. A copolymer rubber was prepared, a crosslinked product was obtained in the same manner, and each evaluation was performed. The results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000001
  
Figure JPOXMLDOC01-appb-T000001
  
　表１に示すように、マレイン酸モノｎ－ブチル単位（ｂ１）を所定割合で含有し、補外ガラス転移開始温度（Ｔｉｇ）と補外ガラス転移終了温度（Ｔｅｇ）との温度差（ΔＴ）が５～１１℃の範囲にあるニトリル基含有高飽和共重合ゴムを用いて得られる架橋物は、常態物性を良好に保ちながら、耐寒性に優れ、Ｄｉｓｋ圧縮永久ひずみ、およびＯ－リング圧縮ひずみが小さくなる（優れる）結果となった（実施例１、２）。 As shown in Table 1, a mono-n-butyl maleate unit (b1) is contained at a predetermined ratio, and a temperature difference (ΔT) between the extrapolation glass transition start temperature (Tig) and the extrapolation glass transition end temperature (Teg). The cross-linked product obtained by using a nitrile group-containing highly saturated copolymer rubber having a temperature of 5 to 11 ° C. has excellent cold resistance while maintaining good normal state properties, Disk compression set, and O-ring compression strain Was smaller (excellent) (Examples 1 and 2).
　これに対して、マレイン酸モノｎ－ブチルを中途添加しない場合には、温度差（ΔＴ）が１３℃と本発明で規定する範囲外となり、圧縮永久ひずみが大きく（劣っている）、耐寒性に劣る結果となった（比較例１）。 On the other hand, when mono n-butyl maleate is not added halfway, the temperature difference (ΔT) is 13 ° C., which is outside the range specified in the present invention, the compression set is large (inferior), and the cold resistance (Comparative Example 1).

Claims (7)

  1. 　α，β－エチレン性不飽和ニトリル単量体単位（ａ）１０～６０重量％、マレイン酸モノブチル単位（ｂ１）および／またはフマル酸モノブチル単位（ｂ２）０．１～２０重量％、ならびに、共役ジエン単量体単位（ｃ）および飽和化共役ジエン単量体単位（ｄ）の合計２０～８９．９重量％を含有し、前記単量体単位（ｃ）と前記単量体単位（ｄ）との合計含有量に対する前記単量体単位（ｄ）の含有量が７０重量％以上であるニトリル基含有高飽和共重合ゴムであって、
    　示差走査熱量測定における補外ガラス転移開始温度（Ｔｉｇ）と補外ガラス転移終了温度（Ｔｅｇ）の温度差が５～１１℃であるニトリル基含有高飽和共重合ゴム。     α, β-ethylenically unsaturated nitrile monomer unit (a) 10 to 60% by weight, monobutyl maleate unit (b1) and / or monobutyl fumarate unit (b2) 0.1 to 20% by weight, and conjugation A total of 20 to 89.9% by weight of the diene monomer unit (c) and the saturated conjugated diene monomer unit (d), the monomer unit (c) and the monomer unit (d) A nitrile group-containing highly saturated copolymer rubber having a content of the monomer unit (d) of 70% by weight or more based on the total content of
    Nitrile group-containing highly saturated copolymer rubber having a temperature difference of 5 to 11 ° C. between the extrapolated glass transition start temperature (Tig) and the extrapolated glass transition end temperature (Teg) in differential scanning calorimetry.
  2. 　請求項１に記載のニトリル基含有高飽和共重合ゴムと、架橋剤と、を含有してなる架橋性ゴム組成物。 A crosslinkable rubber composition comprising the nitrile group-containing highly saturated copolymer rubber according to claim 1 and a crosslinking agent.
  3. 　前記架橋剤が、ポリアミン系架橋剤である請求項２に記載の架橋性ゴム組成物。 The crosslinkable rubber composition according to claim 2, wherein the crosslinking agent is a polyamine-based crosslinking agent.
  4. 　請求項２又は３に記載の架橋性ゴム組成物を架橋してなる架橋物。 A cross-linked product obtained by cross-linking the cross-linkable rubber composition according to claim 2 or 3.
  5. 　Ｏ－リングである請求項４に記載の架橋物。 The cross-linked product according to claim 4, which is an O-ring.
  6. 　請求項１に記載のニトリル基含有高飽和共重合ゴムを製造する方法であって、
    　前記α，β－エチレン性不飽和ニトリル単量体単位（ａ）、前記共役ジエン単量体単位（ｃ）および前記飽和化共役ジエン単量体単位（ｄ）を構成することとなる単量体の全量、ならびに、前記マレイン酸モノブチル単位（ｂ１）および／またはフマル酸モノブチル単位（ｂ２）を構成することとなる単量体の全量のうち一部を用いて、共重合を開始し、
    　次いで、重合転化率が１０～７５％となった時点で、マレイン酸モノブチル単位（ｂ１）および／またはフマル酸モノブチル単位（ｂ２）を構成することとなる単量体の全量のうちの残部を追加添加して共重合体を得た後、
    　該共重合体に対して、選択的に水素添加するニトリル基含有高飽和共重合体ゴムの製造方法。     A method for producing the nitrile group-containing highly saturated copolymer rubber according to claim 1,
    Monomers that constitute the α, β-ethylenically unsaturated nitrile monomer unit (a), the conjugated diene monomer unit (c), and the saturated conjugated diene monomer unit (d) And a part of the total amount of monomers constituting the monobutyl maleate unit (b1) and / or the monobutyl fumarate unit (b2), and the copolymerization is started.
    Subsequently, when the polymerization conversion rate becomes 10 to 75%, the remainder of the total amount of monomers constituting the monobutyl maleate unit (b1) and / or the monobutyl fumarate unit (b2) is added. After adding to obtain a copolymer,
    A method for producing a highly saturated copolymer rubber containing a nitrile group, wherein the copolymer is selectively hydrogenated.
  7. 　共重合開始時に用いる前記マレイン酸モノブチル単位（ｂ１）および／またはフマル酸モノブチル単位（ｂ２）を構成することとなる単量体の比率が、該単量体の全量１００重量％に対して１０～９０重量％である請求項６に記載のニトリル基含有高飽和共重合体ゴムの製造方法。 The ratio of the monomers constituting the monobutyl maleate unit (b1) and / or the monobutyl fumarate unit (b2) used at the start of copolymerization is 10 to 10% with respect to 100% by weight of the total amount of the monomers. The method for producing a nitrile group-containing highly saturated copolymer rubber according to claim 6, which is 90% by weight.
PCT/JP2009/066906 2008-09-30 2009-09-29 Highly saturated copolymer rubber containing nitrile group, cross-linkable rubber composition comprising same, and cross-linked product WO2010038720A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2010531850A JP5652205B2 (en) 2008-09-30 2009-09-29 Crosslinkable rubber composition and cross-linked product

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2008-252349 2008-09-30
JP2008252349 2008-09-30

Publications (1)

Publication Number Publication Date
WO2010038720A1 true WO2010038720A1 (en) 2010-04-08

Family

ID=42073481

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2009/066906 WO2010038720A1 (en) 2008-09-30 2009-09-29 Highly saturated copolymer rubber containing nitrile group, cross-linkable rubber composition comprising same, and cross-linked product

Country Status (2)

Country Link
JP (1) JP5652205B2 (en)
WO (1) WO2010038720A1 (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015146973A1 (en) * 2014-03-26 2015-10-01 日本ゼオン株式会社 Nitrile copolymer rubber composition
WO2016148055A1 (en) * 2015-03-13 2016-09-22 日本ゼオン株式会社 Nitrile rubber composition and crosslinked rubber product
WO2016148054A1 (en) * 2015-03-13 2016-09-22 日本ゼオン株式会社 Nitrile rubber composition and crosslinked rubber substance
WO2017010370A1 (en) * 2015-07-15 2017-01-19 日本ゼオン株式会社 Nitrile rubber composition and crosslinked rubber product
CN106916349A (en) * 2015-12-04 2017-07-04 住友橡胶工业株式会社 Rubber composition and the pneumatic tire with the tyre surface produced using the rubber composition
WO2018198998A1 (en) * 2017-04-26 2018-11-01 日本ゼオン株式会社 Method for producing crosslinked rubber object

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5420091A (en) * 1977-07-18 1979-02-15 Japan Synthetic Rubber Co Ltd Preparation of heat-resistant, flexing-resistant rubber
JPH07268004A (en) * 1995-03-13 1995-10-17 Nippon Zeon Co Ltd Production of modified hydrogenated nitrile rubber
JP2001114940A (en) * 1999-10-15 2001-04-24 Nippon Zeon Co Ltd Rubber, crosslinkable rubber composition and crosslinked product
WO2005030859A1 (en) * 2003-09-30 2005-04-07 Zeon Corporation Crosslinkabel rubber composition and crosslinked object
JP2006131918A (en) * 2006-02-16 2006-05-25 Nippon Zeon Co Ltd Vulcanizable rubber composition including ethylenically unsaturated carboxylic metal salt
JP2008163074A (en) * 2006-12-27 2008-07-17 Nippon Zeon Co Ltd Cross-linkable nitrile rubber composition and cross-linked rubber

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5420091A (en) * 1977-07-18 1979-02-15 Japan Synthetic Rubber Co Ltd Preparation of heat-resistant, flexing-resistant rubber
JPH07268004A (en) * 1995-03-13 1995-10-17 Nippon Zeon Co Ltd Production of modified hydrogenated nitrile rubber
JP2001114940A (en) * 1999-10-15 2001-04-24 Nippon Zeon Co Ltd Rubber, crosslinkable rubber composition and crosslinked product
WO2005030859A1 (en) * 2003-09-30 2005-04-07 Zeon Corporation Crosslinkabel rubber composition and crosslinked object
JP2006131918A (en) * 2006-02-16 2006-05-25 Nippon Zeon Co Ltd Vulcanizable rubber composition including ethylenically unsaturated carboxylic metal salt
JP2008163074A (en) * 2006-12-27 2008-07-17 Nippon Zeon Co Ltd Cross-linkable nitrile rubber composition and cross-linked rubber

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10266628B2 (en) 2014-03-26 2019-04-23 Zeon Corporation Nitrile copolymer rubber composition
CN106103569A (en) * 2014-03-26 2016-11-09 日本瑞翁株式会社 Lonitrile copolymer rubber composition
JPWO2015146973A1 (en) * 2014-03-26 2017-04-13 日本ゼオン株式会社 Nitrile copolymer rubber composition
WO2015146973A1 (en) * 2014-03-26 2015-10-01 日本ゼオン株式会社 Nitrile copolymer rubber composition
WO2016148055A1 (en) * 2015-03-13 2016-09-22 日本ゼオン株式会社 Nitrile rubber composition and crosslinked rubber product
WO2016148054A1 (en) * 2015-03-13 2016-09-22 日本ゼオン株式会社 Nitrile rubber composition and crosslinked rubber substance
JPWO2016148054A1 (en) * 2015-03-13 2017-12-28 日本ゼオン株式会社 Nitrile rubber composition and rubber cross-linked product
JPWO2016148055A1 (en) * 2015-03-13 2017-12-28 日本ゼオン株式会社 Nitrile rubber composition and rubber cross-linked product
US10287382B2 (en) 2015-03-13 2019-05-14 Zeon Corporation Nitrile rubber composition and cross-linked rubber
WO2017010370A1 (en) * 2015-07-15 2017-01-19 日本ゼオン株式会社 Nitrile rubber composition and crosslinked rubber product
CN106916349A (en) * 2015-12-04 2017-07-04 住友橡胶工业株式会社 Rubber composition and the pneumatic tire with the tyre surface produced using the rubber composition
US10106667B2 (en) * 2015-12-04 2018-10-23 Sumitomo Rubber Industries, Ltd. Rubber composition and pneumatic tire comprising tread formed from said rubber composition
WO2018198998A1 (en) * 2017-04-26 2018-11-01 日本ゼオン株式会社 Method for producing crosslinked rubber object
JPWO2018198998A1 (en) * 2017-04-26 2020-03-12 日本ゼオン株式会社 Method for producing cross-linked rubber
JP7103352B2 (en) 2017-04-26 2022-07-20 日本ゼオン株式会社 Method for manufacturing rubber crosslinked products

Also Published As

Publication number Publication date
JPWO2010038720A1 (en) 2012-03-01
JP5652205B2 (en) 2015-01-14

Similar Documents

Publication Publication Date Title
JP5640748B2 (en) Nitrile group-containing highly saturated copolymer rubber
JP5861698B2 (en) Highly saturated nitrile rubber composition and rubber cross-linked product
EP2902437B1 (en) Crosslinkable rubber composition and crosslinked rubber
JP5742719B2 (en) Crosslinkable nitrile rubber composition and method for producing the same
JP5092395B2 (en) Crosslinkable nitrile rubber composition and rubber cross-linked product
WO2012090941A1 (en) Rubber composition and crosslinked rubber product
US10287382B2 (en) Nitrile rubber composition and cross-linked rubber
JP5716585B2 (en) Crosslinkable rubber composition and rubber cross-linked product
JP6465103B2 (en) Crosslinkable rubber composition and method for producing crosslinked rubber
JP5652205B2 (en) Crosslinkable rubber composition and cross-linked product
JP5983626B2 (en) Nitrile rubber composition and rubber cross-linked product
JP6380107B2 (en) Nitrile rubber composition and rubber cross-linked product
JP2008179671A (en) Cross-linkable nitrile rubber composition and rubber cross-linked product
JP6614153B2 (en) Highly saturated nitrile rubber composition and rubber cross-linked product
JP5135792B2 (en) Crosslinkable rubber composition and rubber cross-linked product

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09817752

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2010531850

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09817752

Country of ref document: EP

Kind code of ref document: A1