JP4012342B2 - Carbon black for functional rubber member and rubber composition for functional member - Google Patents
Carbon black for functional rubber member and rubber composition for functional member Download PDFInfo
- Publication number
- JP4012342B2 JP4012342B2 JP22317199A JP22317199A JP4012342B2 JP 4012342 B2 JP4012342 B2 JP 4012342B2 JP 22317199 A JP22317199 A JP 22317199A JP 22317199 A JP22317199 A JP 22317199A JP 4012342 B2 JP4012342 B2 JP 4012342B2
- Authority
- JP
- Japan
- Prior art keywords
- rubber
- carbon black
- functional
- less
- rubber composition
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired - Lifetime
Links
Landscapes
- Compositions Of Macromolecular Compounds (AREA)
- Pigments, Carbon Blacks, Or Wood Stains (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、各種工業用機能ゴム部材、例えば自動車のエンジンマウントなどに用いられる防振ゴム部材や窓枠シール部材をはじめとしてホース、ベルトなどの機能ゴム部材に配合されるカーボンブラック、及び、このカーボンブラックを配合した機能部材用ゴム組成物に関する。
【０００２】
【従来の技術】
ゴム補強用のカーボンブラックには具備特性に応じた多様の品種があり、これらの品種特性がゴムに配合した場合の諸性能を決定する主要な因子となることから、ゴムへの配合に当たっては部材用途に適合する品種特性のカーボンブラックが選定使用されている。
【０００３】
例えば、自動車のエンジンマウントなどに用いられる防振ゴム部材や窓枠シール部材をはじめホース、ベルトなどの各種工業用機能ゴム部材には、使用時に加えられる伸長、圧縮などの多様な物理的外力に耐えることが必要であり、特にこれらの機能ゴム部材には破壊特性が高く、耐疲労性に優れていることが要求される。
【０００４】
従来から、これら機能ゴム部材に配合されるカーボンブラックとしては粒子径が大きく、比表面積の小さいソフト系カーボンブラックが有用されている。そこで、配合するカーボンブラックのコロイダル特性の改善により耐疲労性に優れ、機能ゴム部材として好適なゴム組成物を得る試みが盛んに行われている。例えば本出願人は、１μ以上の微小球状炭化物の含有率が０．３％以下、窒素吸着比表面積が７０m2/g未満のオイルファーネスブラックを、ゴム成分１００重量部に対して２０〜２００重量部の割合で配合してなることを特徴とするゴム組成物（特開昭64−31843 号公報）を開発した。
【０００５】
更に、本出願人は凝集体の遠心沈降法(DCF法) により測定されるモード径(Dst) が１５０nm以上、前記モード径(Dst) とその半値幅 (ΔDst)の比 (ΔDst/Dst)が１．５０以上、着色力(T) とブラックネス(B) との比(B/T) が１．２０以上の特性を備える機能部品ゴム配合用カーボンブラック（特開平３−14848 号公報）や天然ゴムまたはジエン系合成ゴム１００重量部に対し、窒素吸着比表面積(N2SA)≦６０m2/g、ＤＢＰ吸油量≦１００ml/100g 、１３０nm≦Ｄst≦２２０nm、ΔＤst／Ｄst≦０．９５の選択的特性を有するカーボンブラックを２０〜１００重量部配合したゴム組成物（特開平４−18438 号公報）などを開発提案した。
【０００６】
【発明が解決しようとする課題】
しかしながら、機能ゴム部材にもより厳しい使用環境下における製品寿命の延長化に対する要求が強く、更なる改良が望まれている。そこで、本発明者らは耐疲労性に優れ、機能用ゴム部材として好適な性能を付与し得るカーボンブラックの開発について鋭意研究した結果、ゴム成分中におけるカーボンブラックの分散状態が大きく影響するとともにゴム組成物に物理的外力が作用した際に破壊の起点となる核を低減させることが有効であることを見出した。
【０００７】
すなわち、本発明は上記の知見に基づいて開発されたものであって、その目的はゴム成分に配合してゴム組成物とした際に、伸長、圧縮などの多様な物理的外力に対する耐破壊性が高く、優れた耐疲労性能を付与することのできる機能ゴム部材用カーボンブラック、及び、このカーボンブラックを配合した機能部材用ゴム組成物を提供することにある。
【０００８】
【課題を解決するための手段】
上記目的を達成するための本発明に係る機能ゴム部材用カーボンブラックは、窒素吸着比表面積（Ｎ２ＳＡ）が７０ｍ２／ｇ以下であって、造粒粒子の硬さ（ＩＰＨ）の平均値が１０ｃＮ以下で８．４ｃＮ以上、標準偏差（σｎ−１）が４ｃＮ以下で３．０ｃＮ以上の造粒粒子性状を備えることを構成上の特徴とする。
【０００９】
また、好ましくは上記構成において、ふるい残分(Gr45)が０．０００２wt％以下に設定される。
【００１０】
本発明の機能部材用ゴム組成物は、ゴム１００重量部に対し、窒素吸着比表面積（Ｎ２ＳＡ）が７０ｍ２／ｇ以下であって、造粒粒子の硬さ（ＩＰＨ）の平均値が１０ｃＮ以下で８．４ｃＮ以上、標準偏差（σｎ−１）が４ｃＮ以下で３．０ｃＮ以上の造粒粒子性状を備えるカーボンブラック、または更に、ふるい残分（Ｇｒ４５）が０．０００２ｗｔ％以下であるカーボンブラックを、１０〜２００重量部配合してなることを構成上の特徴とする。
【００１１】
【発明の実施の形態】
本発明で特定した機能ゴム部材用カーボンブラックの特性のうち、窒素吸着比表面積(N2SA)が７０m2/g以下の要件は、ゴム組成物とした場合に耐疲労性能を向上させるための前提的要件となるものであり、この値が７０m2/gを越えるとゴム組成物が硬質化し、また発熱性が増大して熱老化を招くなど、機能部材用途には不適となる。
【００１２】
本発明の機能ゴム部材用カーボンブラックは、上記の窒素吸着比表面積（Ｎ２ＳＡ）が７０ｍ２／ｇ以下の前提的要件に加えて、造粒粒子の硬さ（ＩＰＨ）の平均値が１０ｃＮ以下で８．４ｃＮ以上、その標準偏差（σｎ−１）が４ｃＮ以下で３．０ｃＮ以上の造粒粒子性状を備えることが必要である。
【００１３】
カーボンブラックをゴムに混練してゴム成分中に分散させる過程は、先ずカーボンブラックの造粒粒子が破壊され、壊れながらゴム中に混入していく。この混練時に造粒粒子は破壊されながらアグロメレートの状態へと解砕され、更に混練を続けると分散の最小単位であるアグリゲートの状態にまでカーボンブラックを微分散させることができる。すなわち、カーボンブラックをゴム成分に配合して補強性能を充分に発現させるためには、ゴム中におけるカーボンブラックの分散状態が大きく影響し、アグリゲートの状態で分散（ミクロ分散）させることが重要となる。
【００１４】
カーボンブラックの凝集形態は、数個から数十個のカーボンブラックの基本微粒子が不規則で複雑な鎖状に融着結合して最小単位の凝集体（アグリゲート）を形成し、更にこれらのアグリゲートが相互に絡み合ったり、付着して再凝集した集合体（アグロメレート）から構成されている。したがって、カーボンブラックはゴム中においてアグリゲートの状態で分散（ミクロ分散）させることが重要となり、アグロメレートの状態での分散（マクロ分散）をできるだけ避けることが望ましいこととなる。
【００１５】
この分散過程において、カーボンブラックの造粒粒子の硬さ（ＩＰＨ）が高い場合には、ゴム成分との混練時に造粒粒子の破壊が円滑に進まず、均質なマクロ分散状態を形成することが困難となる。その結果、混練を継続しても均一なミクロ分散状態へ移行させることが難しくなる。そこで、本発明は均質なミクロ分散状態を形成させるために、造粒粒子の硬さ（ＩＰＨ）の平均値を１０ｃＮ（センチニュートン）以下に設定するものである。造粒粒子の硬さ（ＩＰＨ）の平均値が１０ｃＮを越えると初期混練時において造粒粒子が充分に破壊されないために、ゴム中においてカーボンブラック未分散塊が生じ易く、均質にマクロ分散させることが困難となる。その結果、均一なミクロ分散状態への移行が難しくなり、分散不良による耐疲労性能の低下がもたらされることになる。一方、造粒粒子の硬さ（ＩＰＨ）が低くなると、カーボンブラックのハンドリングの過程で造粒粒子の破壊が生じ易くなり、微粉量が増大することになる。微粉量が増大するとゴム練り加工時においてゴム成分への分散性が低下し、またハンドリング性も悪化することになる。そこで、造粒粒子の硬さ（ＩＰＨ）の平均値を８．４ｃＮ以上に設定する。
【００１６】
更に、造粒粒子の硬さ（ＩＰＨ）の標準偏差（σｎ−１）は４ｃＮ以下であることが必要である。カーボンブラックのゴム中への分散性は、上述のように造粒粒子の硬さ（ＩＰＨ）が大きく影響するが、ＩＰＨの影響は平均値のみでなく個々の造粒粒子の硬さの影響も大きく、ＩＰＨが高い造粒粒子が存在するとゴムとの混練時に充分に破壊されずに未分散塊となって、ゴム中への拡散が妨げられるためミクロ分散不良の原因となる。すなわち、分散不良の原因となる硬い造粒粒子の存在を排除するために、本発明は造粒粒子の硬さ（ＩＰＨ）の平均値を１０ｃＮ以下に設定するとともに、その標準偏差（σｎ−１）を４ｃＮ以下の造粒粒子性状に設定する。標準偏差（σｎ−１）が４ｃＮを越える硬粒が存在すると、ゴム成分に混練する際に硬粒の破壊が円滑に進まないためにマクロ分散性が低下し、更にミクロ分散への移行が妨げられ、分散不良による耐疲労性能の低下がもたらされる。また、標準偏差（σ ｎ−１ ）が４ｃＮを越える場合には造粒粒子の硬さ（ＩＰＨ）の分布が広くなるので、硬粒が存在するのと同様に軟らかい粒子の存在頻度も増大することになる。軟粒の存在量が多くなれば、ハンドリング時に微粉化が生じ易くなり、またゴムとの混練時におけるゴム成分への分散性の低下が起こる。そのため、造粒粒子の硬さ（ＩＰＨ）の標準偏差（σ ｎ−１ ）は３．０ｃＮ以上に設定される。
【００１７】
本発明の機能ゴム部材用カーボンブラックは、上記の特性に加えて、ふるい残分(Gr45)の値が０．０００２wt％以下に設定される。カーボンブラックは、その生成過程において原料炭化水素の熱分解時にごく一部の原料炭化水素が急速かつ高度に重縮合して硬質なコークス粒を生成し易い。また、コークスとは別に、製造装置から混入する、例えば製造炉煉瓦の剥離片や製造装置の劣化による鉄錆などの金属錆片が混入する。これらのコークス、煉瓦剥離片、金属錆片などの異物（グリット）は適宜な手段により除去されるが、ごく一部はカーボンブラック中に残存する。
【００１８】
これらのグリットは表面活性が極めて低いために、ゴム成分との結合力が殆どなく、ゴム組成物中においては夾雑物として存在することとなる。したがって、ゴム組成物に伸長、圧縮などの物理的外力が繰り返し作用するとグリットが離脱してその部分が空洞化し、破壊の起点となり易い。また、グリットが大きいほど空洞部も大きくなり、破壊の進行が助長されることとなる。そこで、本発明はカーボンブラック中に混在するグリットとして４５μm 以上のグリット(Gr45)を対象に、その量を０．０００２wt％以下とすることによりゴム組成物に物理的外力が作用した際の破壊の起点となる核生成の低減化を図るものである。
【００１９】
上記の構成におけるカーボンブラックの各特性は、下記の測定方法によって得られた値が適用される。
▲１▼窒素吸着比表面積（Ｎ2 ＳＡ）；
ＡＳＴＭ Ｄ3037−88 “Standard Test Methods for Carbon Black-Surface Area by Nitrogen Absorption”Method Bによる。
▲２▼造粒粒子の硬さ（ＩＰＨ）；
ＪＩＳＫ6219−1997「ゴム用カーボンブラックの基本性能の試験方法」７項Ａ法による。
▲３▼ふるい残分（Ｇｒ45）；
ＪＩＳＫ6218−1997「ゴム用カーボンブラックの試験方法」７項による。
【００２０】
本発明の機能ゴム部材用カーボンブラックはオイルファーネス法により製造され、空気量、燃料油量、原料油量などを制御するとともに造粒条件を制御することにより製造される。また、グリット量の調整は遠心力分級、強制渦流分級などの適宜な分級手段により行われる。
【００２１】
本発明の機能ゴム部材用カーボンブラックは、常法に従って加硫剤、加硫促進剤、老化防止剤、軟化剤、可塑剤などの必要成分とともにゴム成分に配合して、混練、加硫処理することにより目的とする機能部材用ゴム組成物が得られる。ゴム成分としては、天然ゴムをはじめスチレンブタジエンゴム、ポリブタジエンゴム、エチレン−プロピレンゴムなどの各種合成ゴムや混合ゴムが対象となる。これらのゴム成分に配合するカーボンブラック量は、ゴム成分１００重量部に対しカーボンブラック１０〜２００重量部の量比に設定される。カーボンブラックの配合比が１０重量部未満では充分な強度が得られず、一方２００重量部を越えると加工性が低下することとなる。
【００２２】
【実施例】
以下、本発明の実施例を比較例と対比して説明する。
【００２３】
実施例１〜４、比較例１〜４
カーボンブラック製造炉に供給する空気量、燃料油量、原料油量などを制御して発生した窒素吸着比表面積(N2SA)の異なるカーボンブラックを、分級プロセスに通してグリットの摩砕、分級除去を行い、次いで、湿式造粒法により造粒機のピン回転数、粉末カーボンブラック供給量、造粒水量などを変更して造粒粒子性状及びふるい残分(Gr45)の異なるカーボンブラックを製造した。
【００２４】
次に、これらのカーボンブラックを、表１に示す配合比率で天然ゴムに配合した。
【００２５】
【表１】
これらの配合物を１６０℃の温度で１０分間加硫してゴム組成物を作製し、得られたゴム組成物についてゴム物性を測定した。得られた結果をカーボンブラックの性状とともに表２に示した。なお、ゴム物性の測定は下記の方法により行った。
【００２７】
▲１▼硬さ：
ＪＩＳＫ6301「加硫ゴム物理試験方法」により測定。
▲２▼伸長疲労寿命：
ゴム疲労試験機〔（株）インフィニット・ニシ製〕を用いて、以下の条件で測定し、切断までの平均寿命回数（MTTF、n;16）を求めた。
試料；３号ダンベル
歪み条件；20mmの標線間の歪み率 0〜80％
加振周波数； 5Hz
雰囲気温度；室温
▲３▼カーボンブラック分散率：
ＡＳＴＭ Ｄ2663Ｂ法により測定。
【００２８】
【表２】
表２の結果から、Ｎ2 ＳＡが同等である実施例１、３と比較例１、３及び実施例２、４と比較例２、４とを対比すると、ＩＰＨの平均値が１０cNを越え、標準偏差σn-1 が４cNを上回る造粒粒子性状のカーボンブラックを配合した比較例のゴム組成物は、対応する実施例のゴム組成物に比べて伸長疲労寿命が短く、ゴム組成物中におけるカーボンブラック分散率も低位にあることが判る。
【００３０】
更に、カーボンブラック中のグリットの混在量として、ふるい残分（Ｇｒ45）を０．０００２wt％以下に調整することにより、伸長疲労寿命の延命化を図ることができることが認められる。
【００３１】
【発明の効果】
以上のとおり、窒素吸着比表面積（Ｎ２ＳＡ）が７０ｍ２／ｇ以下であって、造粒粒子の硬さ（ＩＰＨ）の平均値が１０ｃＮ以下で８．４ｃＮ以上、標準偏差（σｎ−１）が４ｃＮ以下で３．０ｃＮ以上の造粒粒子性状を備えた本発明の機能ゴム部材用カーボンブラックは分散性能に優れており、ゴム成分中へミクロな分散状態で、すなわちアグリゲートの状態で均一に分散させることができる。したがって、ゴムに配合してゴム組成物とした際に、分散不良による耐疲労性能の低下を抑制することが可能となる。更に、カーボンブラック中に混在するグリット（ふるい残分Ｇｒ４５）を０．０００２ｗｔ％以下とすることにより、ゴム組成物に物理的外力が作用した際の破壊の起点となる核生成が低減化し、耐疲労性をより向上させることが可能となる。
【００３２】
したがって、例えば、自動車のエンジンマウントなどに用いられる防振ゴム部材や窓枠シール部材をはじめホース、ベルトなどの各種工業用機能ゴム部材に配合される機能ゴム部材用カーボンブラック、及びこのカーボンブラックを配合した機能部材用ゴム組成物として産業上極めて有用である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to various industrial functional rubber members, for example, carbon black blended in functional rubber members such as vibration-proof rubber members and window frame seal members used for automobile engine mounts, hose and belt, and the like. The present invention relates to a rubber composition for a functional member containing carbon black.
[0002]
[Prior art]
There are various varieties of carbon black for rubber reinforcement depending on the characteristics of these materials, and these varieties are the main factors that determine the performance when blended with rubber. Carbon black with variety characteristics suitable for the application is selected and used.
[0003]
For example, various industrial functional rubber members such as expansion and compression applied at the time of use can be applied to vibration-proof rubber members and window frame seal members used in automobile engine mounts, as well as various industrial functional rubber members such as hoses and belts. In particular, these functional rubber members are required to have high fracture characteristics and excellent fatigue resistance.
[0004]
Conventionally, soft carbon black having a large particle size and a small specific surface area has been useful as a carbon black blended in these functional rubber members. Therefore, many attempts have been made to obtain a rubber composition that is excellent in fatigue resistance and is suitable as a functional rubber member by improving the colloidal characteristics of carbon black to be blended. For example, the present applicant applies 20 to 200 weights of oil furnace black having a content of fine spherical carbide of 1 μm or more and 0.3% or less and a nitrogen adsorption specific surface area of less than 70 m 2 / g with respect to 100 parts by weight of the rubber component. A rubber composition (Japanese Patent Laid-Open No. 64-31843) characterized by being blended at a ratio of parts was developed.
[0005]
Further, the applicant has a mode diameter (Dst) of 150 nm or more measured by the centrifugal sedimentation method (DCF method) of the aggregate, and the ratio (ΔDst / Dst) of the mode diameter (Dst) and its half-value width (ΔDst) is Carbon black for compounding functional parts rubber having a characteristic of 1.50 or more and a ratio (B / T) of coloring power (T) to blackness (B) of 1.20 or more (Japanese Patent Laid-Open No. 3-14848) Nitrogen adsorption specific surface area (N 2 SA) ≦ 60 m 2 / g, DBP oil absorption ≦ 100 ml / 100 g, 130 nm ≦ Dst ≦ 220 nm, ΔDst / Dst ≦ 0.95 with respect to 100 parts by weight of natural rubber or diene synthetic rubber A rubber composition containing 20 to 100 parts by weight of carbon black having selective characteristics (JP-A-4-18438) has been developed and proposed.
[0006]
[Problems to be solved by the invention]
However, there is a strong demand for extending the service life of the functional rubber member in a more severe use environment, and further improvement is desired. Accordingly, as a result of earnest research on the development of carbon black that has excellent fatigue resistance and can provide suitable performance as a functional rubber member, the present inventors have greatly influenced the dispersion state of carbon black in the rubber component and the rubber. It has been found that it is effective to reduce nuclei that are the starting points of destruction when a physical external force is applied to the composition.
[0007]
That is, the present invention has been developed based on the above knowledge, and its purpose is to have a fracture resistance against various physical external forces such as elongation and compression when blended with a rubber component to form a rubber composition. The object of the present invention is to provide a carbon black for a functional rubber member that is high and can impart excellent fatigue resistance, and a rubber composition for a functional member that contains this carbon black.
[0008]
[Means for Solving the Problems]
The carbon black for functional rubber members according to the present invention for achieving the above object has a nitrogen adsorption specific surface area (N 2 SA) of 70 m 2 / g or less, and an average value of the hardness (IPH) of the granulated particles. Is characterized by having a granulated particle property of 10 cN or less and 8.4 cN or more , and a standard deviation (σ n-1 ) of 4 cN or less and 3.0 cN or more .
[0009]
Preferably, in the above configuration, the sieve residue (Gr 45 ) is set to 0.0002 wt% or less.
[0010]
The rubber composition for a functional member of the present invention has a nitrogen adsorption specific surface area (N 2 SA) of 70 m 2 / g or less and an average value of the hardness (IPH) of the granulated particles with respect to 100 parts by weight of rubber. Carbon black having a granulated particle property of 10 cN or less and 8.4 cN or more and a standard deviation (σ n-1 ) of 4 cN or less and 3.0 cN or more , or a sieve residue (Gr 45 ) of 0.0002 wt% or less It is a structural feature that 10 to 200 parts by weight of carbon black is blended.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Among the characteristics of the carbon black for functional rubber members specified in the present invention, the requirement that the nitrogen adsorption specific surface area (N 2 SA) is 70 m 2 / g or less is to improve the fatigue resistance when a rubber composition is used. This is a prerequisite, and if this value exceeds 70 m 2 / g, the rubber composition becomes hard, and the exothermic property increases, leading to heat aging, which makes it unsuitable for functional member applications.
[0012]
The carbon black for functional rubber members of the present invention has an average value of the hardness (IPH) of the granulated particles of 10 cN in addition to the precondition that the nitrogen adsorption specific surface area (N 2 SA) is 70 m 2 / g or less. It is necessary to have a granulated particle property of 8.4 cN or more and a standard deviation (σ n-1 ) of 4 cN or less and 3.0 cN or more .
[0013]
In the process of kneading carbon black into rubber and dispersing it in the rubber component, first, the granulated particles of carbon black are broken and mixed into the rubber while being broken. During this kneading, the granulated particles are crushed to agglomerate while being broken, and when the kneading is continued, carbon black can be finely dispersed to the aggregate state which is the minimum unit of dispersion. In other words, in order for carbon black to be added to the rubber component and to fully develop the reinforcing performance, it is important that the dispersion state of the carbon black in the rubber is greatly affected and dispersed in the aggregate state (micro dispersion). Become.
[0014]
The aggregate form of carbon black is that several to several tens of basic carbon black particles are fused and bonded in an irregular and complex chain to form aggregates (aggregates) of the smallest units. The gates are composed of aggregates (agglomerates) that are intertwined with each other or adhere and reaggregate. Therefore, it is important to disperse carbon black in an aggregated state (microdispersion) in the rubber, and it is desirable to avoid dispersion (macrodispersion) in an agglomerate state as much as possible.
[0015]
In this dispersion process, when the hardness (IPH) of the granulated particles of carbon black is high, the destruction of the granulated particles does not proceed smoothly during kneading with the rubber component, and a homogeneous macro-dispersed state can be formed. It becomes difficult. As a result, it is difficult to shift to a uniform micro-dispersed state even if kneading is continued. Therefore, in the present invention, in order to form a homogeneous micro-dispersed state, the average value of the hardness (IPH) of the granulated particles is set to 10 cN (centinewton) or less. If the average value of the hardness (IPH) of the granulated particles exceeds 10 cN, the granulated particles are not sufficiently destroyed at the initial kneading, so that an undispersed lump of carbon black is likely to occur in the rubber, and it is uniformly macro-dispersed. It becomes difficult. As a result, it becomes difficult to shift to a uniform micro-dispersed state, resulting in a decrease in fatigue resistance due to poor dispersion. On the other hand, when the hardness (IPH) of the granulated particles is lowered, the granulated particles are easily broken in the process of handling carbon black, and the amount of fine powder is increased. When the amount of fine powder is increased, the dispersibility into the rubber component is lowered during the rubber kneading process, and the handling property is also deteriorated. Therefore, the average value of the hardness (IPH) of the granulated particles is set to 8.4 cN or more.
[0016]
Furthermore, the standard deviation (σ n-1 ) of the hardness (IPH) of the granulated particles needs to be 4 cN or less. The dispersibility of carbon black in rubber is greatly influenced by the hardness of the granulated particles (IPH) as described above. The influence of IPH is not only the average value but also the hardness of individual granulated particles. When granulated particles having a large and high IPH are present, they are not sufficiently broken when kneaded with rubber and become an undispersed lump, which prevents diffusion into the rubber and causes micro-dispersion failure. That is, in order to eliminate the presence of hard granulated particles that cause poor dispersion, the present invention sets the average value of the hardness (IPH) of the granulated particles to 10 cN or less and the standard deviation (σ n− 1 ) is set to a granulated particle property of 4 cN or less. When hard grains having a standard deviation (σ n-1 ) exceeding 4 cN are present, macro-dispersibility is deteriorated because the breakage of the hard grains does not proceed smoothly when kneaded into a rubber component, and further, the transition to micro dispersion occurs. This results in a decrease in fatigue resistance due to poor dispersion. Further, when the standard deviation (σ n-1 ) exceeds 4 cN, the distribution of the hardness (IPH) of the granulated particles becomes wide, so that the presence frequency of the soft particles increases as the hard particles exist. It will be. If the abundance of soft granules increases, pulverization tends to occur during handling, and the dispersibility to the rubber component decreases during kneading with rubber. Therefore, the standard deviation (σ n-1 ) of the hardness (IPH) of the granulated particles is set to 3.0 cN or more.
[0017]
In addition to the above characteristics, the carbon black for functional rubber members of the present invention has a sieve residue (Gr 45 ) value set to 0.0002 wt% or less. Carbon black tends to produce hard coke grains by rapid and highly polycondensation of a small portion of the raw material hydrocarbon during the pyrolysis of the raw material hydrocarbon in the production process. Moreover, apart from coke, for example, stripped pieces of manufacturing furnace bricks or metal rust pieces such as iron rust due to deterioration of the manufacturing apparatus are mixed. Foreign matter (grit) such as coke, brick peeling pieces, and metal rust pieces is removed by an appropriate means, but only a small part remains in the carbon black.
[0018]
Since these grit have extremely low surface activity, they have almost no binding force with the rubber component and are present as impurities in the rubber composition. Therefore, when a physical external force such as elongation or compression is repeatedly applied to the rubber composition, the grit is detached and the portion is hollowed out, which tends to be a starting point of destruction. In addition, the larger the grit, the larger the cavity portion, and the progress of destruction is promoted. Therefore, the present invention is intended for grit (Gr 45 ) of 45 μm or more as grit mixed in carbon black, and the amount is 0.0002 wt% or less, so that the destruction is caused when physical external force acts on the rubber composition. This is intended to reduce the nucleation that is the starting point of the above.
[0019]
Values obtained by the following measurement methods are applied to the respective characteristics of carbon black in the above configuration.
(1) Nitrogen adsorption specific surface area (N 2 SA);
According to ASTM D3037-88 “Standard Test Methods for Carbon Black-Surface Area by Nitrogen Absorption” Method B.
(2) Granulated particle hardness (IPH);
According to JIS K6219-1997 “Testing method for basic performance of carbon black for rubber”, item 7A.
(3) Sieve residue (Gr 45 );
According to JIS K6218-1997 “Testing method of carbon black for rubber”, item 7.
[0020]
The carbon black for functional rubber members of the present invention is produced by an oil furnace method, and is produced by controlling the amount of air, the amount of fuel oil, the amount of raw material oil, and the like, as well as the granulation conditions. The grit amount is adjusted by appropriate classification means such as centrifugal force classification or forced vortex classification.
[0021]
The carbon black for functional rubber members of the present invention is kneaded and vulcanized according to a conventional method by blending with rubber components together with necessary components such as a vulcanizing agent, a vulcanization accelerator, an anti-aging agent, a softening agent and a plasticizer. Thus, the intended rubber composition for functional members is obtained. The rubber component includes natural rubber, styrene butadiene rubber, polybutadiene rubber, various synthetic rubbers such as ethylene-propylene rubber, and mixed rubber. The amount of carbon black blended in these rubber components is set to a ratio of 10 to 200 parts by weight of carbon black with respect to 100 parts by weight of the rubber component. When the compounding ratio of the carbon black is less than 10 parts by weight, sufficient strength cannot be obtained, while when it exceeds 200 parts by weight, the workability is lowered.
[0022]
【Example】
Examples of the present invention will be described below in comparison with comparative examples.
[0023]
Examples 1-4, Comparative Examples 1-4
Carbon black with different nitrogen adsorption specific surface area (N 2 SA) generated by controlling the amount of air, fuel oil, raw material oil, etc. supplied to the carbon black production furnace is ground and classified through the classification process. Next, carbon black with different granulated particle properties and sieve residue (Gr 45 ) is obtained by changing the pin rotation speed of the granulator, the amount of powder carbon black supplied, the amount of granulated water etc. by wet granulation method. Manufactured.
[0024]
Next, these carbon blacks were blended with natural rubber at a blending ratio shown in Table 1.
[0025]
[Table 1]
These blends were vulcanized at a temperature of 160 ° C. for 10 minutes to prepare rubber compositions, and the rubber properties of the obtained rubber compositions were measured. The obtained results are shown in Table 2 together with the properties of carbon black. The rubber physical properties were measured by the following method.
[0027]
▲ 1 ▼ Hardness:
Measured according to JIS K6301 “Vulcanized Rubber Physical Test Method”.
(2) Elongation fatigue life:
Using a rubber fatigue tester (manufactured by Infinite Nishi Co., Ltd.), measurement was performed under the following conditions, and the average number of times of life until cutting (MTTF, n; 16) was obtained.
Sample: No. 3 dumbbell distortion condition: 20-80mm distortion rate between 0 and 80%
Excitation frequency: 5Hz
Atmospheric temperature; room temperature (3) Carbon black dispersion ratio:
Measured by ASTM D2663B method.
[0028]
[Table 2]
From the results of Table 2, when Examples 1 and 3 having the same N 2 SA and Comparative Examples 1 and 3 and Examples 2 and 4 are compared with Comparative Examples 2 and 4, the average value of IPH exceeds 10 cN, The rubber composition of the comparative example blended with carbon black having a granulated particle property with a standard deviation σ n-1 exceeding 4 cN has a shorter elongation fatigue life than the rubber composition of the corresponding example, and the rubber composition in the rubber composition It can be seen that the carbon black dispersion ratio is also low.
[0030]
Furthermore, it is recognized that the elongation fatigue life can be extended by adjusting the sieve residue (Gr 45 ) to 0.0002 wt% or less as the amount of grit in the carbon black.
[0031]
【The invention's effect】
As described above, the nitrogen adsorption specific surface area (N 2 SA) is 70 m 2 / g or less, the average value of the hardness (IPH) of the granulated particles is 10 cN or less , 8.4 cN or more , and the standard deviation (σ n− 1 ) The carbon black for functional rubber members of the present invention having a granulated particle property of 4 cN or less and 3.0 cN or more is excellent in dispersion performance and is in a micro-dispersed state in the rubber component, that is, in an aggregate state Can be uniformly dispersed. Therefore, when blended with rubber to obtain a rubber composition, it is possible to suppress a decrease in fatigue resistance due to poor dispersion. Furthermore, by making the grit (sieving residue Gr 45 ) mixed in the carbon black 0.0002 wt% or less, nucleation as a starting point of fracture when physical external force acts on the rubber composition is reduced, It becomes possible to further improve the fatigue resistance.
[0032]
Therefore, for example, carbon black for functional rubber members to be blended in various industrial functional rubber members such as vibration-proof rubber members and window frame seal members used for automobile engine mounts, hoses, belts, and the like. Industrially useful as a blended rubber composition for functional members.
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22317199A JP4012342B2 (en) | 1999-08-06 | 1999-08-06 | Carbon black for functional rubber member and rubber composition for functional member |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22317199A JP4012342B2 (en) | 1999-08-06 | 1999-08-06 | Carbon black for functional rubber member and rubber composition for functional member |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001049027A JP2001049027A (en) | 2001-02-20 |
| JP4012342B2 true JP4012342B2 (en) | 2007-11-21 |
Family
ID=16793924
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22317199A Expired - Lifetime JP4012342B2 (en) | 1999-08-06 | 1999-08-06 | Carbon black for functional rubber member and rubber composition for functional member |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4012342B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101528864B (en) * | 2006-10-20 | 2012-10-10 | 电气化学工业株式会社 | Granular acetylene black, process for production thereof, and composition |
| JP5542416B2 (en) * | 2009-11-04 | 2014-07-09 | 旭カーボン株式会社 | Soft-type furnace carbon black for anti-vibration rubber compounding and anti-vibration rubber composition containing the same |
| JP2017036362A (en) * | 2015-08-07 | 2017-02-16 | 東洋ゴム工業株式会社 | Rubber composition |
-
1999
- 1999-08-06 JP JP22317199A patent/JP4012342B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JP2001049027A (en) | 2001-02-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3810098B2 (en) | Rubber composition | |
| JP6250537B2 (en) | Elastomer composition comprising regenerated vulcanized elastomer particles with wide size distribution and chemically modified vulcanized elastomer particles | |
| JP2000080302A (en) | Hard-based high structure carbon black and rubber composition blended with carbon black | |
| JP6383602B2 (en) | Rubber composition, crosslinked rubber composition and tire | |
| KR20100101079A (en) | Elastomer composition with reclaimed filler materials | |
| JP4012342B2 (en) | Carbon black for functional rubber member and rubber composition for functional member | |
| JP3895210B2 (en) | Carbon black and rubber composition thereof | |
| JPH11323024A (en) | Tread rubber composition for studless tire | |
| JPH08169983A (en) | Rubber composition for tire tread | |
| US5225475A (en) | Rubber composition | |
| JP5543284B2 (en) | Rubber composition and tire using the same | |
| JP3456759B2 (en) | Furnace carbon black | |
| JP2006199832A (en) | Tire tread rubber composition | |
| JP2003096332A (en) | Hard carbon black | |
| JPH06212025A (en) | Rubber composition | |
| CN1302055C (en) | Method for vulcanizing caoutchouc or latex by applying a mixture of sulfur and a complexing agent | |
| JPH1030066A (en) | Production of carbon black and rubber composition | |
| JP3316267B2 (en) | Rubber composition for tire tread | |
| JP3929838B2 (en) | Carbon black and rubber composition thereof | |
| JP3152445B2 (en) | Rubber composition | |
| JP2903097B2 (en) | Carbon black and rubber composition containing the same | |
| RU2119508C1 (en) | Curable carbon chain-based rubber compound | |
| JPH0471950B2 (en) | ||
| RU2765552C2 (en) | Method for producing filler for rubber mixtures from composition of one-type granular technical carbons | |
| JP2007131774A (en) | Resin composition |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20050615 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20050617 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20050914 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20070809 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20070907 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4012342 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100914 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110914 Year of fee payment: 4 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120914 Year of fee payment: 5 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120914 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130914 Year of fee payment: 6 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| EXPY | Cancellation because of completion of term |