JP3960907B2 - Acrylic rubber composition - Google Patents

Description

（式中のＲ１は第三ブチル基、Ｒ２は第三ブチル基、Ｒ３は炭素数１〜８のアルキル基またはＣＨ_２ＣＨ_２ＣＯＯＲ４：但しＲ４は炭素数１〜１８のアルキル基）
【００２４】
化学式（１）で示されるフェノール系老化防止剤としては、２，６−ジ−第三ブチル−４−メチルフェノール、２，６−ジ−第三ブチル−４−エチルフェノール、２，６−ジ−第三ブチル−４−プロピルフェノール、２，６−ジ−第三ブチル−４−ブチルフェノール、２，６−ジ−第三ブチル−４−ペンチルフェノール、２，６−ジ−第三ブチル−４−ヘキシルフェノール、２，６−ジ−第三ブチル−４−ヘプチルフェノール、２，６−ジ−第三ブチル−４−オクチルフェノール、ｎ−オクチル−３−（４’−ヒドロキシ−３’５’−ジ−第三ブチルフェニル）プロピオネート、ｎ−オクタデシル−３−（４’−ヒドロキシ−３’５’−ジ−第三ブチルフェニル）プロピオネートなどが挙げられる。
【００２５】
フェノール系老化防止剤の添加量は、アクリル系ゴム１００質量部に対して、０．３〜１０質量部が好ましく、０．５〜５質量部が更に好ましい。
０．３質量部未満では熱劣化の防止効果が不十分であり、１０質量部を越えると常態物性が悪くなり好ましくない。
【００２６】
モノアミン化合物としては、１級アミン、２級アミン、３級アミンのうち少なくとも１種以上のモノアミン化合物が用いられる。
【００２７】
１級アミン化合物としては、メチルアミン、エチルアミン、プロピルアミン、ブチルアミン、ペンチルアミン、ヘキシルアミン、ヘプチルアミン、オクチルアミン、ノニルアミン、デシルアミン、ウンデシルアミン、ドデシルアミン、テトラデシルアミン、ヘキサドデシルアミン、ステアリルアミン、オクタデシルアミン、エイコシルアミン、メタノールアミン、エタノールアミン、アニリン、シクロヘキシルアミン、ベンジルアミン、２−アミノトルエン、３−アミノトルエン、４−アミノトルエン、２，４−ジメチルアニリン、２，３−ジメチルアニリン、２，５−ジメチルアニリン、２，６−ジメチルアニリン、３，４−ジメチルアニリン、３，５−ジメチルアニリン、２，４，５−トリメチルアニリン、２，４，６−トリメチルアニリン、３，４，５，６−テトラメチルアニリン、２，４，５，６−テトラメチルアニリン、２，３，５，６−テトラメチルアニリン、２−エチル−３−ヘキシルアニリン、２−エチル−４−ヘキシルアニリン、２−エチル−５−ヘキシルアニリン、２−エチル−６−ヘキシルアニリン、３−エチル−４−ヘキシルアニリン、３−エチル−５−ヘキシルアニリン、３−エチル−２−ヘキシルアニリン、４−エチル−２−ヘキシルアニリン、５−エチル−２−ヘキシルアニリン、４−エチル−３−ヘキシルアニリン、６−エチル−２−ヘキシルアニリン、５−エチル−３−ヘキシルアニリン、３，４，６−トリエチルアニリン、２−メトキシアニリン、３−メトキシアニリン、４−メトキシアニリン、２−メトキシ−３−メチルアニリン、２−メトキシ−４−メチルアニリン、２−メトキシ−５−メチルアニリン、２−メトキシ−６−メチルアニリン、３−メトキシ−２−メチルアニリン、３−メトキシ−４−メチルアニリン、３−メトキシ−５−メチルアニリン、３−メトキシ−６−メチルアニリン、４−メトキシ−２−メチルアニリン、４−メトキシ−３−メチルアニリン、２−エトキシアニリン、３−エトキシアニリン、４−エトキシアニリン、４−メトキシ−５−メチルアニリン、４−メトキシ−６−メチルアニリン、２−メトキシ−３−エチルアニリン、２−メトキシ−４−エチルアニリン、２−メトキシ−５−エチルアニリン、２−メトキシ−６−エチルアニリン、３−メトキシ−２−エチルアニリン、３−メトキシ−４−エチルアニリン、３−メトキシ−５−エチルアニリン、３−メトキシ−６−エチルアニリン、４−メトキシ−２−エチルアニリン、４−メトキシ−３−エチルアニリン、２−メトキシ−２，３，４−トリメチルアニリン、３−メトキシ−２，４，５−トリメチルアニリン、４−メトキシ−２，３，５−トリメチルアニリン、ビス（２−シアノエチル）アミンなどが挙げられる。
【００２８】
２級アミン化合物としては、ジメチルアミン、ジエチルアミン、ジプロピルアミン、ジブチルアミン、ジペンチルアミン、ジヘキシルアミン、ジヘプチルアミン、ジオクチルアミン、ジノニルアミン、ジデシルアミン、ジウンデシルアミン、ジドデシルアミン、ジテトラデシルアミン、ジヘキサデシルアミン、ジメタノールアミン、ジエタノールアミン、ジフェニルアミン、ジシクロヘキシルアミン、ニトロソジメチルアミン、ニトロソジフェニルアミンなどが挙げられる。
【００２９】
３級アミン化合物としては、トリメチルアミン、トリエチルアミン、トリプロピルアミン、トリブチルアミン、トリペンチルアミン、トリヘキシルアミン、トリヘプチルアミン、トリオクチルアミン、トリノニルアミン、トリデシルアミン、トリウンデシルアミン、トリドデシルアミン、トリテトラデシルアミン、トリヘキサドデシルアミン、トリステアリルアミン、トリオクタデシルアミン、トリエイコシルアミン、トリメタノールアミン、トリエタノールアミン、トリフェニルアミン、トロシクロヘキシルアミンなどが挙げられる。
【００３０】
上記モノアミン化合物の添加量はアクリル系ゴム１００質量部に対して、０．０１〜１０質量部が好ましく、０．０５〜２質量部が更に好ましい。０．０１質量部未満ではロール加工性が著しく悪くなり、一方１０質量部を越えると加硫が遅くなり十分な加硫物特性が発現しなくなる。
【００３１】
本発明のアクリル系ゴム組成物は、実用に供するに際してその目的に応じ、充填剤、補強剤、可塑剤、滑剤、老化防止剤、安定剤、シランカップリング剤等を添加して成形、加硫を行うことができる。
【００３２】
アミン系老化防止剤、ヒドロキノン系老化防止剤、キノリン系老化防止剤、ベンズイミダゾール系老化防止剤、チオウレア系老化防止剤、カルバミン酸塩系老化防止剤、亜リン酸系老化防止剤など請求項記載以外の老化防止剤は、要求されるゴム物性から、２種以上を混合して使用することが可能である。
これらの添加量は合計で、アクリル系ゴム１００質量部に対して０．５〜１０質量部程度添加することができる。
【００３３】
また、カーボンブラック、無水ケイ酸、表面処理炭酸カルシウムなどの充填剤、補強剤も、要求されるゴム物性から、２種以上を混合して使用することが可能である。
これらの添加量は合計で、アクリル系ゴム１００質量部に対して３０〜１００質量部が好ましい。
【００３４】
可塑剤としては、通常ゴム用として使用されている可塑剤を添加することができる。例えばエステル系可塑剤、ポリオキシエチレンエーテル系可塑剤、トリメリテート系可塑剤などが挙げられるが、上記に限定されるものではなく、各種の可塑剤が使用できる。
可塑剤の添加量としては、アクリル系ゴム１００質量部に対して、５０質量部程度まで添加できる。
【００３５】
本発明で用いられるアクリル系ゴム組成物におけるゴム成分は、アクリル系ゴムを主成分とするものであるが、アクリル系ゴムの他に、必要に応じて天然ゴム、合成ゴム、例えばＩＩＲ、ＢＲ、ＮＢＲ、ＨＮＢＲ、ＣＲ、ＥＰＤＭ、ＦＫＭ、Ｑ、ＣＳＭ、ＣＯ、ＥＣＯ、ＣＭ等を含有することができる。
【００３６】
また、本発明のアクリル系ゴム組成物及びその加硫物を混練、成型、加硫する機械としては、通常ゴム工業で用いるものを使用することができる。
【００３７】
本発明のアクリル系ゴム組成物及びその加硫物は特にゴムホースやガスケット、パッキング等のシール部品及び防振部材として好適に用いられる。また、ゴムホースとしては、具体的には自動車、建設機械、油圧機器等のトランスミッションオイルクーラーホース、エンジンオイルクーラーホース、エアダクトホース、ターボインタークーラーホース、ホットエアーホース、ラジエターホース、パワーステアリングホース、燃料系ホース、ドレイン系ホース等に使用されるホースに用いられる。
また、シール部品としては、具体的には、エンジンヘッドカバーガスケット、オイルパンガスケット、オイルシール、リップシールパッキン、Ｏ−リング、トランスミッションシールガスケット、クランクシャフト、カムシャフトシールガスケット、バルブステム、パワーステアリングシールベルトカバーシール、ＣＶＪ及びＲ＆Ｐブーツ材等が挙げられる。
また、防振ゴム部品としては、ダンパープーリー、センターサポートクッション、サスペンションブッシュ等が挙げられる。
【００３８】
ゴムホースの構成としては、本発明のアクリル系ゴム組成物から得た単一ホース、あるいは、ゴムホースの用途によっては、本発明のアクリル系ゴムからなる層に本発明のアクリル系ゴム以外の合成ゴム、例えば、フッ素系ゴム、フッ素変性アクリルゴム、ヒドリンゴム、ＣＳＭ、ＣＲ、ＮＢＲ、ＨＮＢＲ、エチレン・プロピレンゴム等を内層、中間層、あるいは外層として組み合わせた複合ホースへの適用も可能である。
また、ゴムホースに要求される特性によっては、一般的に行われているように補強糸あるいはワイヤーをホースの中間あるいは、ゴムホースの最外層に設けることも可能である。
【００３９】
「実施例」
以下に実施例をもって本発明を更に詳細に説明するが、本発明はこれらの実施例によって何ら制限されるものではない。
「実験例１」
ポリマーＡの作製
内容積４０リットルの耐圧反応容器に、アクリル酸エチル７．８Ｋｇ、アクリル酸ｎ−ブチル３．４Ｋｇ、マレイン酸モノブチル０．５Ｋｇ、部分ケン化ポリビニルアルコール４質量％の水溶液１７Ｋｇ、酢酸ナトリウム２２ｇを投入し、攪拌機であらかじめよく混合し、均一懸濁液を作製した。槽内上部の空気を窒素で置換後、エチレンを槽上部に圧入し、圧力を２０Ｋｇ／ｃｍ２に調整した。攪拌を続行し、槽内を５５℃に保持した後、別途注入口よりｔ−ブチルヒドロペルオキシド水溶液を圧入して重合を開始させた。反応中槽内温度は５５℃に保ち、６時間で反応が終了した。生成した重合液に硼酸ナトリウム水溶液を添加して重合体を固化し、脱水及び乾燥を行って生ゴムとした
【００４０】
「実験例２」
ポリマーＢの作製
エチレンを導入しない以外は実験例１と同様な方法で生ゴムを得た。
【００４１】
「実施例及び比較例」
表１に示した配合処方により、８インチロールを用いて配合して得たアクリル系ゴム組成物について評価した。
加硫物の物性試験は、配合物をスチーム加熱式の熱プレスにて１７０℃×２０分間加硫して、試験片（一次加硫物）を作製した。更に熱空気（ギヤーオーブン）にて１７０℃×４時間加硫した後、この試験片（二次加硫物）を用いて、引張強さ、切断時伸び等の力学的特性を、ＪＩＳ Ｋ６２５１に準拠して測定した。
硬さはＪＩＳ Ｋ６２５３に準拠してデュロメータ硬さ計を用いて、測定を行った。
圧縮永久歪み試験は、ＪＩＳ Ｋ６２６２に準拠して行った（試験条件は１５０℃×７０時間）。
耐熱性は、ＪＩＳ Ｋ６２５７に準拠し、１７５℃×７０時間曝露後の引張試験の引張強さの変化率を求めた。変化率は、その絶対値が小さいほど耐熱性が良いことを示す。
【００４２】
【表１】

【００４３】
【表２】

【００４４】
表１及び表２で用いたＭＡＦは、東海カーボン株式会社製シースト１１６である。
【００４５】
【発明の効果】
実施例と比較例の対比で示すように、本発明のアクリル系ゴム組成物からなる加硫物は、常態物性、圧縮永久歪み特性に優れ、且つ熱老化時の引張強さの変化率と伸びの変化率のバランスに優れている。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an acrylic rubber composition. More specifically, the acrylic rubber composition is excellent in normal physical properties and compression set characteristics and excellent in the balance between the tensile strength change rate and the elongation change rate during heat aging. The present invention relates to a rubber composition.
[0002]
[Prior art]
Acrylic rubber is used as a heat and oil resistant material for hose parts and seal parts in the engine room of automobiles. However, due to recent measures against exhaust gas and higher engine output, thermal conditions are becoming more severe. Therefore, more heat resistance than before is desired.
[0003]
In addition, hose parts and seal parts are required to have physical properties such as normal properties and compression set properties, and in recent years, scorch is used to improve vulcanization speed and workability for the purpose of improving productivity. There is a need for improvement in sex.
[0004]
As described above, acrylic rubber having a carboxyl group as a crosslinking site has been used as a material having a balance of processability, vulcanization speed, normal physical properties, compression set characteristics, heat resistance and the like.
[0005]
A conventional acrylic rubber composition having a carboxyl group as a crosslinking site is also recognized as a material having a balance of processability, vulcanization speed, normal physical properties, compression set properties, heat resistance, etc. Due to such severe use conditions, further improvement in heat resistance is demanded, and in particular, there is a demand for stricter change in tensile strength and elongation in thermal aging (for example, patents). Reference 1).
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 11-1000047 (page 4-5, table)
[0007]
[Problems to be solved by the invention]
The present invention solves the above problems, is an acrylic rubber composition excellent in normal physical properties, compression set characteristics, and excellent balance between the tensile strength change rate and elongation change rate during heat aging, and its vulcanization An object and a hose part, a seal part, and a vibration-proof rubber part using the same are provided.
[0008]
[Means for Solving the Problems]
As a result of intensive studies in order to solve the above-mentioned problems, the present inventors have combined a guanidine compound, a diamine compound, and a phenolic anti-aging agent with a carboxyl group-containing acrylic rubber to obtain normal properties, compression permanent Acrylic rubber composition with excellent strain characteristics and excellent balance between the rate of change in tensile strength and the rate of change in elongation during heat aging, its vulcanizate, and hose parts, seal parts, vibration-proof rubber parts using the same The present invention has been found to be able to be provided.
[0009]
The present invention is described in detail below.
The carboxyl group-containing acrylic rubber of the present invention is an unsaturated carboxylic acid such as acrylic acid or methacrylic acid, or an aliphatic unsaturated dicarboxylic acid such as maleic acid, fumaric acid, itaconic acid or citraconic acid. Or monomethylmalate, monoethylmalate, mono-n-propylmalate, monoisopropylmalate, mono-n-butylmalate, monoisobutylmalate, monomethylfumarate, monoethylfumarate, mono-n-propylfumarate , Monoisopropyl fumarate, mono-n-butyl fumarate, monoisobutyl fumarate, monomethyl itaconate, monoethyl itaconate, mono-n-propyl itaconate, mono-n-propyl citraconate, mono-n-butyl Citraconate, monoisobuty Acrylic rubber characterized by copolymerizing one or more monomers selected from the group of aliphatic dicarboxylic acid monoesters such as citraconate at a ratio of about 0.1 to 30% by mass in the polymer It is.
[0010]
The carboxyl group-containing acrylic rubber of the present invention is obtained by copolymerizing the above carboxyl group-containing unsaturated fatty acid and an unsaturated monomer such as an alkyl acrylate ester.
Examples of the acrylic acid alkyl ester include methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-pentyl acrylate, n-hexyl acrylate, n-octyl acrylate, and 2-ethylhexyl acrylate.
[0011]
Further, other copolymerizable acrylic acid alkyl esters include n-decyl acrylate, n-dodecyl acrylate, n-octadecyl acrylate, cyanomethyl acrylate, 1-cyanoethyl acrylate, 2-cyanoethyl acrylate, 1-cyanopropyl acrylate, 2- Examples include cyanopropyl acrylate, 3-cyanopropyl acrylate, 4-cyanobutyl acrylate, 6-cyanohexyl acrylate, 2-ethyl-6-cyanohexyl acrylate, and 8-cyanooctyl acrylate.
[0012]
Also, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2- (n-propoxy) ethyl acrylate, 2- (n-butoxy) ethyl acrylate, 3-methoxypropyl acrylate, 3-ethoxypropyl acrylate, 2- (n Examples thereof include alkoxyalkyl esters of acrylic acid such as -propoxy) propyl acrylate and 2- (n-butoxy) propyl acrylate.
[0013]
Further, 1,1-dihydroperfluoroethyl (meth) acrylate, 1,1-dihydroperfluoropropyl (meth) acrylate, 1,1,5-trihydroperfluorohexyl (meth) acrylate, 1,1,2,2-tetrahydro Fluorine-containing compounds such as perfluoropropyl (meth) acrylate, 1,1,7-trihydroperfluoroheptyl (meth) acrylate, 1,1-dihydroperfluorooctyl (meth) acrylate, 1,1-dihydroperfluorodecyl (meth) acrylate ( Hydroxyl group-containing (meth) acrylic acid ester such as (meth) acrylic acid ester, 1-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxyethyl (meth) acrylate, diethylaminoethyl (meta) Acrylates, tertiary amino group-containing, such as dibutyl aminoethyl (meth) acrylate (meth) acrylic acid esters, methacrylic acid esters such as methyl acrylate, octyl methacrylate.
[0014]
Further, the carboxyl group-containing acrylic rubber of the present invention may be a copolymer obtained by copolymerizing another monomer copolymerizable with the above-mentioned monomer within a range not impairing the object of the present invention.
Other monomers that can be copolymerized include alkyl vinyl ketones such as methyl vinyl ketone, vinyl and allyl ethers such as vinyl ethyl ether and allyl methyl ether, styrene, α-methyl styrene, chlorostyrene, vinyl toluene, and vinyl. Vinyl aromatic compounds such as naphthalene, vinyl nitriles such as acrylonitrile and methacrylonitrile, acrylamide, vinyl acetate, ethylene, propylene, butadiene, isoprene, pentadiene, vinyl chloride, vinylidene chloride, vinyl fluoride, vinylidene fluoride, vinyl propionate , Epoxy group-containing compounds such as ethylenically unsaturated compounds such as alkyl fumarate, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, methallyl glycidyl ether, 2 Chloroethyl vinyl ether, 2-chloroethyl acrylate, vinyl benzyl chloride, vinyl chloroacetate, and active chlorine-containing compounds such as allyl chloroacetate.
[0015]
The carboxyl group-containing acrylic rubber of the present invention can be obtained by copolymerizing the above monomers using a known method such as emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization and the like.
[0016]
The acrylic rubber composition of the present invention combines a carboxyl group-containing acrylic rubber with a guanidine compound, a diamine compound, and a phenolic anti-aging agent, thereby vulcanizing products such as good hose parts, seal parts, vibration-proof rubber parts, etc. Can be obtained.
[0017]
Examples of the guanidine compound include guanidine, tetramethylguanidine, dibutylguanidine, diphenylguanidine, di-o-tolylguanidine, and di-o-tolylguanidine is preferably used.
[0018]
The addition amount of the guanidine compound is preferably 0.1 to 10 parts by mass, more preferably 0.3 to 5 parts by mass with respect to 100 parts by mass of the acrylic rubber. When the amount is less than 0.1 parts by mass, the vulcanization reaction is not sufficiently performed, and when the amount exceeds 10 parts by mass, overvulcanization occurs. In this case, compression set at a high temperature is deteriorated.
[0019]
Hexamethylenediamine, hexamethylenediamine carbamate, aliphatic diamine such as triethylenetetramine, tetraethylenepentamine, 4,4′-diaminodicyclohexylmethane, 3,3′-dimethyl4,4′-diaminodicyclohexylmethane, 1,3 -Alicyclic diamines such as bis (aminomethyl) cyclohexane, dihydrazides such as adipic acid dihydrazide, sebacic acid dihydrazide, isophthalic acid dihydrazide, 4,4'-methylenedianiline, o-phenylenediamine, m-phenylenediamine, p- Examples include phenylenediamine, o-toluylenediamine, m-toluylenediamine, o-xylylenediamine, m-xylylenediamine, p-xylylenediamine, and aromatic diamines represented by the following structural formula (1). ,processing From the viewpoint of stability, an aromatic diamine represented by the following structural formula (1) is preferably used.
Formula _{(1): H 2 N-} ph-M-ph-NH 2
However, M is one of O, S, SO ₂ , CONH or O—R—O.
However, O-R-O for _{R, ph, ph-ph, ph} -SO 2 -ph, (CH 2) m ··· where _{m = 3~5, ph -C (CX} 3) 2 -p h ... X = H or F, or one of (CH ₂ ) C (CH ₃ ) ₂ (CH ₂ ).
ph represents a benzene ring.
[0020]
As the compound of the structural formula (1), 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-diaminodiphenyl sulfide, 1,3-bis (4-aminophenoxy) -2,2-dimethyl Propane, 1,3-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) pentane, 2,2-bis [4- ( 4-aminophenoxy) phenyl] propane, 4,4′-diaminodiphenylsulfone, bis (4-3-aminophenoxy) phenylsulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzanilide, bis [4- ( - such aminophenoxy) phenyl] sulfone and the like.
[0021]
The addition amount of the diamine compound is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass with respect to 100 parts by mass of the acrylic rubber.
If it is 0.01 parts by mass or less, the vulcanization reaction is not sufficiently performed, and if it exceeds 10 parts by mass, the processing stability is deteriorated.
[0022]
Examples of phenolic antioxidants include 1-oxy-3-methyl-4-isopropylbenzene, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol 2,6-di-tert-butyl-α-dimethylamino-p-cresol, 2,2′-methylene-bis- (4-methyl-6-tert-butylphenol), 2,2′-methylene-bis- (4-ethyl-6-tert-butylphenol), 4,4′-methylene-bis- (2,6-di-tert-butylphenol), 4,4′-thiobis- (6-tert-butyl-3-methyl) Phenol, 4,4′-butylidenebis- (3-methyl-6-tert-butylphenol), n-octadecyl-3- (4′-hydroxy-3′5′-di-tert-butylphenyl) propionate, tetrakis- [ Methylene 3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionate] phenolic antioxidants such as methane, and the like, but phenolic antioxidants represented by the following chemical formula (1) Are preferably used.
[0023]
[Chemical 2]

(Wherein R1 is a tertiary butyl group, R2 is a tertiary butyl group, R3 is an alkyl group having 1 to 8 carbon atoms or CH ₂ CH ₂ COOR4, where R4 is an alkyl group having 1 to 18 carbon atoms)
[0024]
Examples of the phenolic anti-aging agent represented by the chemical formula (1) include 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,6-diphenol. Tert-butyl-4-propylphenol, 2,6-di-tert-butyl-4-butylphenol, 2,6-di-tert-butyl-4-pentylphenol, 2,6-di-tert-butyl-4 -Hexylphenol, 2,6-di-tert-butyl-4-heptylphenol, 2,6-di-tert-butyl-4-octylphenol, n-octyl-3- (4'-hydroxy-3'5'- And di-tert-butylphenyl) propionate and n-octadecyl-3- (4′-hydroxy-3′5′-di-tert-butylphenyl) propionate.
[0025]
The addition amount of the phenolic anti-aging agent is preferably 0.3 to 10 parts by mass, more preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the acrylic rubber.
If it is less than 0.3 parts by mass, the effect of preventing thermal deterioration is insufficient, and if it exceeds 10 parts by mass, the normal physical properties are deteriorated.
[0026]
As the monoamine compound, at least one monoamine compound of primary amine, secondary amine, and tertiary amine is used.
[0027]
Primary amine compounds include methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tetradecylamine, hexadodecylamine, stearylamine , Octadecylamine, eicosylamine, methanolamine, ethanolamine, aniline, cyclohexylamine, benzylamine, 2-aminotoluene, 3-aminotoluene, 4-aminotoluene, 2,4-dimethylaniline, 2,3-dimethylaniline 2,5-dimethylaniline, 2,6-dimethylaniline, 3,4-dimethylaniline, 3,5-dimethylaniline, 2,4,5-trimethylaniline, 2,4,6-trimethylaniline 3,4,5,6-tetramethylaniline, 2,4,5,6-tetramethylaniline, 2,3,5,6-tetramethylaniline, 2-ethyl-3-hexylaniline, 2-ethyl -4-hexylaniline, 2-ethyl-5-hexylaniline, 2-ethyl-6-hexylaniline, 3-ethyl-4-hexylaniline, 3-ethyl-5-hexylaniline, 3-ethyl-2-hexylaniline 4-ethyl-2-hexylaniline, 5-ethyl-2-hexylaniline, 4-ethyl-3-hexylaniline, 6-ethyl-2-hexylaniline, 5-ethyl-3-hexylaniline, 3,4, 6-triethylaniline, 2-methoxyaniline, 3-methoxyaniline, 4-methoxyaniline, 2-methoxy-3-methylaniline, 2-methyl Xyl-4-methylaniline, 2-methoxy-5-methylaniline, 2-methoxy-6-methylaniline, 3-methoxy-2-methylaniline, 3-methoxy-4-methylaniline, 3-methoxy-5-methyl Aniline, 3-methoxy-6-methylaniline, 4-methoxy-2-methylaniline, 4-methoxy-3-methylaniline, 2-ethoxyaniline, 3-ethoxyaniline, 4-ethoxyaniline, 4-methoxy-5- Methylaniline, 4-methoxy-6-methylaniline, 2-methoxy-3-ethylaniline, 2-methoxy-4-ethylaniline, 2-methoxy-5-ethylaniline, 2-methoxy-6-ethylaniline, 3- Methoxy-2-ethylaniline, 3-methoxy-4-ethylaniline, 3-methoxy-5-ethylaniline 3-methoxy-6-ethylaniline, 4-methoxy-2-ethylaniline, 4-methoxy-3-ethylaniline, 2-methoxy-2,3,4-trimethylaniline, 3-methoxy-2,4 Examples include 5-trimethylaniline, 4-methoxy-2,3,5-trimethylaniline, bis (2-cyanoethyl) amine and the like.
[0028]
Secondary amine compounds include dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, diundecylamine, didodecylamine, ditetradecylamine, ditetramine. Examples include hexadecylamine, dimethanolamine, diethanolamine, diphenylamine, dicyclohexylamine, nitrosodimethylamine, and nitrosodiphenylamine.
[0029]
The tertiary amine compounds are trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, triundecylamine, tridodecylamine. , Tritetradecylamine, trihexadecylamine, tristearylamine, trioctadecylamine, trieicosylamine, trimethanolamine, triethanolamine, triphenylamine, trocyclohexylamine and the like.
[0030]
The addition amount of the monoamine compound is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 2 parts by mass with respect to 100 parts by mass of the acrylic rubber. If it is less than 0.01 parts by mass, the roll processability is remarkably deteriorated. On the other hand, if it exceeds 10 parts by mass, the vulcanization is delayed and sufficient vulcanizate properties are not exhibited.
[0031]
The acrylic rubber composition of the present invention is molded and vulcanized by adding a filler, a reinforcing agent, a plasticizer, a lubricant, an anti-aging agent, a stabilizer, a silane coupling agent, etc. It can be performed.
[0032]
Claims such as amine-based anti-aging agent, hydroquinone-based anti-aging agent, quinoline-based anti-aging agent, benzimidazole-based anti-aging agent, thiourea-based anti-aging agent, carbamate-based anti-aging agent, phosphorous acid-based anti-aging agent Antiaging agents other than can be used in combination of two or more, because of the required rubber properties.
These addition amounts can be added in a total amount of about 0.5 to 10 parts by mass with respect to 100 parts by mass of the acrylic rubber.
[0033]
In addition, fillers such as carbon black, anhydrous silicic acid, and surface-treated calcium carbonate, and reinforcing agents can also be used as a mixture of two or more kinds from the required rubber properties.
The total amount of these additives is preferably 30 to 100 parts by mass with respect to 100 parts by mass of the acrylic rubber.
[0034]
As a plasticizer, a plasticizer usually used for rubber can be added. Examples include ester plasticizers, polyoxyethylene ether plasticizers, trimellitate plasticizers, and the like, but are not limited to the above, and various plasticizers can be used.
The addition amount of the plasticizer can be added up to about 50 parts by mass with respect to 100 parts by mass of the acrylic rubber.
[0035]
The rubber component in the acrylic rubber composition used in the present invention is mainly composed of acrylic rubber. In addition to the acrylic rubber, natural rubber, synthetic rubber such as IIR, BR, NBR, HNBR, CR, EPDM, FKM, Q, CSM, CO, ECO, CM and the like can be contained.
[0036]
Moreover, what is normally used in the rubber industry can be used as a machine which knead | mixes, shape | molds, and vulcanizes the acrylic rubber composition of this invention and its vulcanizate.
[0037]
The acrylic rubber composition and the vulcanized product thereof of the present invention are particularly suitably used as sealing parts such as rubber hoses, gaskets and packings and vibration-proof members. Specific examples of rubber hoses include transmission oil cooler hoses, engine oil cooler hoses, air duct hoses, turbo intercooler hoses, hot air hoses, radiator hoses, power steering hoses, fuel hoses for automobiles, construction machinery, hydraulic equipment, etc. Used in hoses used for drain hoses and the like.
Specific seal parts include engine head cover gasket, oil pan gasket, oil seal, lip seal packing, O-ring, transmission seal gasket, crankshaft, camshaft seal gasket, valve stem, power steering seal belt Cover seals, CVJ, R & P boot materials and the like.
In addition, examples of the vibration-proof rubber parts include a damper pulley, a center support cushion, a suspension bush, and the like.
[0038]
As a structure of the rubber hose, a single hose obtained from the acrylic rubber composition of the present invention, or depending on the use of the rubber hose, a synthetic rubber other than the acrylic rubber of the present invention in a layer made of the acrylic rubber of the present invention, For example, it can be applied to a composite hose in which fluorine rubber, fluorine-modified acrylic rubber, hydrin rubber, CSM, CR, NBR, HNBR, ethylene / propylene rubber or the like is combined as an inner layer, an intermediate layer, or an outer layer.
Further, depending on the characteristics required for the rubber hose, it is possible to provide a reinforcing thread or wire in the middle of the hose or in the outermost layer of the rubber hose, as is generally done.
[0039]
"Example"
The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.
"Experiment 1"
Preparation of polymer A In a pressure resistant reaction vessel having an internal volume of 40 liters, ethyl acrylate 7.8 kg, n-butyl acrylate 3.4 kg, monobutyl maleate 0.5 kg, partially saponified polyvinyl alcohol 4 mass% aqueous solution 17 kg, acetic acid Sodium 22g was added and mixed well in advance with a stirrer to prepare a uniform suspension. After replacing the air in the upper part of the tank with nitrogen, ethylene was injected into the upper part of the tank, and the pressure was adjusted to 20 kg / cm 2. Stirring was continued, and the inside of the tank was maintained at 55 ° C., and then an aqueous t-butyl hydroperoxide solution was injected from a separate inlet to initiate polymerization. During the reaction, the temperature in the tank was maintained at 55 ° C., and the reaction was completed in 6 hours. A sodium borate aqueous solution was added to the resulting polymerization solution to solidify the polymer, followed by dehydration and drying to obtain a raw rubber.
"Experimental example 2"
Preparation of polymer B Raw rubber was obtained in the same manner as in Experimental Example 1 except that ethylene was not introduced.
[0041]
“Examples and Comparative Examples”
The acrylic rubber composition obtained by blending using an 8-inch roll according to the blending formulation shown in Table 1 was evaluated.
In the physical property test of the vulcanized product, the blend was vulcanized at 170 ° C. for 20 minutes with a steam heating type hot press to prepare a test piece (primary vulcanized product). Furthermore, after vulcanization at 170 ° C. for 4 hours in hot air (gear oven), using this test piece (secondary vulcanized product), the mechanical properties such as tensile strength and elongation at break were measured according to JIS K6251. Measured in conformity.
The hardness was measured using a durometer hardness meter in accordance with JIS K6253.
The compression set test was performed according to JIS K6262 (test conditions are 150 ° C. × 70 hours).
The heat resistance was determined in accordance with JIS K6257, and the rate of change in tensile strength in a tensile test after exposure at 175 ° C. for 70 hours was determined. The change rate indicates that the smaller the absolute value, the better the heat resistance.
[0042]
[Table 1]

[0043]
[Table 2]

[0044]
The MAF used in Tables 1 and 2 is Tokai Carbon Co., Ltd. Seast 116.
[0045]
【The invention's effect】
As shown in the comparison between the examples and comparative examples, the vulcanizate comprising the acrylic rubber composition of the present invention is excellent in normal physical properties and compression set properties, and the change rate and elongation of tensile strength during heat aging. The balance of change rate is excellent.

Claims (6)

1,100 to 10 parts by weight of a guanidine compound, 0.01 to 10 parts by weight of 2,2-bis [4- (4-aminophenoxy) phenyl] propane , relative to 100 parts by weight of a carboxyl group-containing acrylic rubber ; 6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 4,4′-thiobis- (6-tert-butyl-3-methylphenol), 4, Phenolic anti-aging selected from 4'-butylidenebis- (3-methyl-6-tert-butylphenol) and n-octadecyl-3- (4'-hydroxy-3 ', 5'-di-tert-butylphenyl) propionate An acrylic rubber composition comprising 0.3 to 10 parts by mass of an agent. Primary amine, secondary amine, claim 1 acrylic rubber composition according made by blending at least one kind of monoamine compound of the tertiary amine. A vulcanized product obtained by vulcanizing the acrylic rubber composition according to any one of claims 1 and 2 . A hose component comprising the vulcanized product according to claim 3 . A seal part comprising the vulcanizate according to claim 3 . Anti-vibration rubber parts comprising the vulcanizate according to claim 3 .