JP2779227B2 - Foamed rubber composition and pneumatic tire using the same - Google Patents
Foamed rubber composition and pneumatic tire using the sameInfo
- Publication number
- JP2779227B2 JP2779227B2 JP1243300A JP24330089A JP2779227B2 JP 2779227 B2 JP2779227 B2 JP 2779227B2 JP 1243300 A JP1243300 A JP 1243300A JP 24330089 A JP24330089 A JP 24330089A JP 2779227 B2 JP2779227 B2 JP 2779227B2
- Authority
- JP
- Japan
- Prior art keywords
- rubber
- foamed rubber
- rubber composition
- foaming
- tread
- 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 - Fee Related
Links
- 229920001971 elastomer Polymers 0.000 title claims description 60
- 239000005060 rubber Substances 0.000 title claims description 60
- 239000000203 mixture Substances 0.000 title claims description 26
- NBOCQTNZUPTTEI-UHFFFAOYSA-N 4-[4-(hydrazinesulfonyl)phenoxy]benzenesulfonohydrazide Chemical compound C1=CC(S(=O)(=O)NN)=CC=C1OC1=CC=C(S(=O)(=O)NN)C=C1 NBOCQTNZUPTTEI-UHFFFAOYSA-N 0.000 claims description 16
- 238000004073 vulcanization Methods 0.000 claims description 16
- 239000004088 foaming agent Substances 0.000 claims description 9
- 229920003244 diene elastomer Polymers 0.000 claims description 8
- CMAUJSNXENPPOF-UHFFFAOYSA-N n-(1,3-benzothiazol-2-ylsulfanyl)-n-cyclohexylcyclohexanamine Chemical compound C1CCCCC1N(C1CCCCC1)SC1=NC2=CC=CC=C2S1 CMAUJSNXENPPOF-UHFFFAOYSA-N 0.000 claims description 2
- 238000005187 foaming Methods 0.000 description 33
- 230000000052 comparative effect Effects 0.000 description 14
- 230000000694 effects Effects 0.000 description 8
- 244000043261 Hevea brasiliensis Species 0.000 description 4
- 241001441571 Hiodontidae Species 0.000 description 4
- 239000003795 chemical substances by application Substances 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 229920003052 natural elastomer Polymers 0.000 description 4
- 229920001194 natural rubber Polymers 0.000 description 4
- 238000000034 method Methods 0.000 description 3
- 230000000704 physical effect Effects 0.000 description 3
- 229920002857 polybutadiene Polymers 0.000 description 3
- 239000007790 solid phase Substances 0.000 description 3
- 229920003048 styrene butadiene rubber Polymers 0.000 description 3
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 description 2
- MHKLKWCYGIBEQF-UHFFFAOYSA-N 4-(1,3-benzothiazol-2-ylsulfanyl)morpholine Chemical compound C1COCCN1SC1=NC2=CC=CC=C2S1 MHKLKWCYGIBEQF-UHFFFAOYSA-N 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 2
- 229920001577 copolymer Polymers 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 229920001821 foam rubber Polymers 0.000 description 2
- 238000004898 kneading Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 229920003051 synthetic elastomer Polymers 0.000 description 2
- 239000005061 synthetic rubber Substances 0.000 description 2
- UOYIYWCAYFTQLH-UHFFFAOYSA-N 3,7-dinitro-1,3,5,7-tetrazabicyclo[3.3.1]nonane Chemical compound C1N2CN([N+](=O)[O-])CN1CN([N+]([O-])=O)C2 UOYIYWCAYFTQLH-UHFFFAOYSA-N 0.000 description 1
- MWRWFPQBGSZWNV-UHFFFAOYSA-N Dinitrosopentamethylenetetramine Chemical compound C1N2CN(N=O)CN1CN(N=O)C2 MWRWFPQBGSZWNV-UHFFFAOYSA-N 0.000 description 1
- 239000005063 High cis polybutadiene Substances 0.000 description 1
- 239000005064 Low cis polybutadiene Substances 0.000 description 1
- 235000021355 Stearic acid Nutrition 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 1
- 230000003712 anti-aging effect Effects 0.000 description 1
- 229920005549 butyl rubber Polymers 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000000428 dust Substances 0.000 description 1
- -1 for example Polymers 0.000 description 1
- 230000009477 glass transition Effects 0.000 description 1
- 229920005555 halobutyl Polymers 0.000 description 1
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 1
- 229920001084 poly(chloroprene) Polymers 0.000 description 1
- 229920001195 polyisoprene Polymers 0.000 description 1
- 238000010058 rubber compounding Methods 0.000 description 1
- 239000008117 stearic acid Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000004636 vulcanized rubber Substances 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
- 235000014692 zinc oxide Nutrition 0.000 description 1
Classifications
-
- Y02T10/862—
Landscapes
- Tyre Moulding (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Tires In General (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） この発明は、独立気泡形成に適する発泡ゴム組成物、
特に安定した発泡率を有し、安定した物性を与える改良
発泡ゴム組成物に関する。また、この発明は、この発泡
ゴム組成物をトレッドに用いた空気入りタイヤに関す
る。The present invention relates to a foamed rubber composition suitable for forming closed cells,
In particular, the present invention relates to an improved foamed rubber composition having a stable foaming rate and providing stable physical properties. The present invention also relates to a pneumatic tire using the foamed rubber composition for a tread.
（従来の技術） 従来、空気入りタイヤは、氷雪路面上を走行する際の
駆動性、制動性及び操縦性（以下、単に氷雪性能とい
う）を確保するために、スパイクピンを用いたが、スパ
イクピンによる粉塵公害及び道路の損傷が起こり、大き
な社会問題になっている。一方、スパイクピンを用いな
い、いわゆるスタッドレスタイヤについて発明者らは、
種々検討を行った結果、独立気泡を有する発泡ゴムをト
レッドに用いた、スパイクピンを使用しないスタッドレ
スタイヤが氷雪性能に著しく効果があることを見いだ
し、特開昭62−283001号、特開昭63−235921号、特開昭
63−90403号公報などに開示した。(Prior Art) Conventionally, pneumatic tires use spike pins to ensure driveability, braking performance and maneuverability (hereinafter simply referred to as ice and snow performance) when traveling on ice and snow road surfaces. Dust pollution and road damage caused by pins have become a major social problem. On the other hand, for so-called studless tires that do not use spike pins, the inventors have:
As a result of various studies, it was found that a studless tire using a foamed rubber having closed cells for a tread and not using a spike pin had a remarkable effect on ice and snow performance, and was disclosed in JP-A-62-283001 and JP-A-63-283001. -235921, JP
63-90403.
しかしながら、独立気泡を有する発泡ゴムをスタッド
レスタイヤのトレッドゴムに適用することは、氷雪性能
には著しい効果が認められるが、常に安定した発泡ゴム
トレッドを作ることが必須の条件となって来る。However, applying foam rubber having closed cells to the tread rubber of a studless tire has a remarkable effect on ice and snow performance, but it is essential to always produce a foam rubber tread that is stable.
すなわち、製品での発泡率のバラツキを極力減少させ
なければならない。発泡率を変動させる要因は数多く見
られ、例えば、練温度、押出温度が変動することで製品
での発泡率が変わり、また未加硫ゴムの放置環境、時間
等によっても製品の発泡率が変動することが分かった。
この発泡率の変動は、氷雪性能のバラツキ、耐摩耗性能
のバラツキなどを生じる。本問題の解決の為には、工程
の管理で多少改善できるが充分なものでなく、むしろ管
理コスト、工数が増加し生産性が低下するなど得策では
ないことが分かった。That is, the variation in the foaming rate in the product must be reduced as much as possible. There are many factors that cause the foaming rate to fluctuate.For example, fluctuations in the kneading temperature and extrusion temperature change the foaming rate of the product, and the foaming rate of the product also fluctuates depending on the uncured rubber leaving environment and time. I found out.
This variation in the foaming ratio causes variations in ice and snow performance, variations in wear resistance performance, and the like. In order to solve this problem, it has been found that the process management can be improved to some extent, but it is not sufficient, but rather it is not an effective measure such as an increase in management cost and man-hour and a decrease in productivity.
（発明が解決しようとする課題） この発明の目的は、生産性を低下させることなく製品
での発泡率のバラツキを少なくし、これによって発泡ゴ
ムの物性を安定させる発泡ゴム組成物を提供することで
ある。また、他の目的は、この発泡ゴム組成物をトレッ
ドに用い、安定した発泡率に基づく安定したタイヤ性能
を有する空気入りタイヤを提供することである。(Problems to be Solved by the Invention) An object of the present invention is to provide a foamed rubber composition which reduces variation in foaming rate in a product without lowering productivity and thereby stabilizes the physical properties of foamed rubber. It is. Another object of the present invention is to provide a pneumatic tire using the foamed rubber composition for a tread and having stable tire performance based on a stable foaming rate.
（課題を解決するための手段） 本発明者らは、前記課題を解決すべく、鋭意研究を重
ねた結果、ジエン系ゴムに下記の特定の発泡剤と加硫促
進剤を組み合わせて配合することにより、意外にも上記
課題を有利に解決しうることを確かめ、この発明を完成
するに至った。(Means for Solving the Problems) The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result, the following specific foaming agents and vulcanization accelerators have been combined with diene rubbers. As a result, it has been surprisingly confirmed that the above problem can be advantageously solved, and the present invention has been completed.
すなわち、この発明は、ジエン系のゴムの少なくとも
１種よりなるゴム成分に発泡剤として式Ｉ で表されるp,p′−オキシビス（ベンゼンスルホニルヒ
ドラジド）（以下OBSHと略称する。）と、加硫促進剤と
して式II で表されるN,N−ジシクロヘキシル−２−ベンゾチアゾ
リルスルフェンアミド（以下DZと略称する。）とを組み
合わせて配合した独立気泡形成に適する発泡ゴム組成物
である。That is, the present invention provides a rubber component comprising at least one diene rubber as a foaming agent of the formula I And p, p'-oxybis (benzenesulfonylhydrazide) (hereinafter abbreviated as OBSH) represented by the following formula: And N, N-dicyclohexyl-2-benzothiazolylsulfenamide (hereinafter abbreviated as DZ).
更に第二の発明として前記発泡ゴム組成物をトレッド
の少なくとも一部に用いた空気入りタイヤを提供する。Furthermore, as a second invention, a pneumatic tire using the foamed rubber composition for at least a part of a tread is provided.
（作 用） この発明の発泡ゴム組成物のゴム成分は、ジエン系ゴ
ム、例えば天然ゴム、ポリイソプレンゴム、高シス及び
低シスポリブタジエンゴム、乳化重合及び溶液重合スチ
レンブタジエン共重合体ゴム、クロロプレンゴム、アク
リロニトリルブタジエン共重合体ゴム、ブチルゴム、ハ
ロゲン化ブチルゴム、エチレンプロピレンジエン共重合
体ゴムの単独又はこれらジエン系ゴムの２種以上のブレ
ンド系である。スタッドレスタイヤのトレッドゴム組成
物として用いる場合、上記ゴムでも充分効果があるがそ
の中でも−60℃以下のガラス転移温度を有するジエン系
ゴムが好ましい。これは、これらのジエン系ゴムを用い
ることによってトレッドが低温においても充分ゴム弾性
を有しているからである。(Operation) The rubber component of the foamed rubber composition of the present invention is a diene rubber, for example, natural rubber, polyisoprene rubber, high cis and low cis polybutadiene rubber, emulsion-polymerized and solution-polymerized styrene-butadiene copolymer rubber, chloroprene rubber Acrylonitrile butadiene copolymer rubber, butyl rubber, halogenated butyl rubber, ethylene propylene diene copolymer rubber alone or a blend of two or more of these diene rubbers. When used as a tread rubber composition for a studless tire, the above rubbers are sufficiently effective, but among them, a diene rubber having a glass transition temperature of −60 ° C. or less is preferable. This is because the tread has sufficient rubber elasticity even at a low temperature by using these diene rubbers.
発泡剤としてアゾビスイソブチロニトリル、ジニトロ
ソペンタメチレンテトラミン、パラトルエンスルホニル
ヒドラジド、OBSH等数種の発泡剤を鋭意検討した結果、
特に驚くべきことにはOBSHが未加硫ゴムの放置安定性が
ずばぬけてよく長期間の放置に対して発泡率の変動が極
めて少ないことがわかった。As a result of intensive study of several foaming agents such as azobisisobutyronitrile, dinitrosopentamethylenetetramine, paratoluenesulfonylhydrazide, OBSH as foaming agents,
In particular, it was surprisingly found that OBSH had excellent storage stability of the unvulcanized rubber, and showed very little change in the foaming ratio over a long period of time.
また、混練、押出し工程における熱履歴に対して安定
した発泡状態を得るべくOBSHと、スルフェンアミド系の
中でも遅効性と言われている加硫促進剤の組合せを鋭意
検討した結果、加硫促進剤としてDZをOBSHと組み合わせ
て使用することによって安定した発泡状態が得られ、ゴ
ム物性としても充分な弾性率が得られた。In addition, to obtain a stable foaming state with respect to the heat history in the kneading and extrusion processes, we studied the combination of OBSH and a vulcanization accelerator, which is said to be slow-acting among sulfenamides, and found that vulcanization was accelerated. By using DZ in combination with OBSH as an agent, a stable foaming state was obtained, and a sufficient elastic modulus was obtained as rubber properties.
OBSHの使用量は、ゴム成分100重量部に対して１〜20
重量部（PHR）であることが好ましく、３〜10PHRである
ことが更に好ましい。1PHR未満では所定の発泡が困難で
あり、20PHRを超える場合、発泡率が高過ぎ、これをト
レッドに用いた空気入りタイヤの耐摩耗性が劣る。この
発明の発泡ゴム組成物の発泡率は、氷雪性能を確保する
為にトレッドに用いた場合、１〜100％が好ましく、５
〜50％であることが更に好ましい。The amount of OBSH used is 1 to 20 with respect to 100 parts by weight of the rubber component.
It is preferably in parts by weight (PHR), more preferably 3 to 10 PHR. If it is less than 1 PHR, predetermined foaming is difficult, and if it exceeds 20 PHR, the foaming ratio is too high, and the abrasion resistance of a pneumatic tire using this as a tread is inferior. The foaming rate of the foamed rubber composition of the present invention is preferably 1 to 100% when used for a tread in order to ensure ice and snow performance, and is preferably 5 to 100%.
More preferably, it is 5050%.
DZの使用量は、ゴム成分100重量部に対して0.2〜5PHR
が好ましい。0.2PHR未満では所定の加硫物性が得難く、
5PHRを超えると焦けの問題が発生し、製造上安定した発
泡ゴム組成物が得難い。DZ is used in an amount of 0.2 to 5 PHR based on 100 parts by weight of the rubber component.
Is preferred. If it is less than 0.2 PHR, it is difficult to obtain the desired vulcanization properties,
If it exceeds 5 PHR, a problem of burning occurs, and it is difficult to obtain a foamed rubber composition which is stable in production.
この発明の発泡ゴム組成物において、前記の発泡剤、
加硫促進剤のほかにカーボンブラック、アロマオイル、
スピンドルオイルなどの軟化剤、老化防止剤、他の加硫
促進剤、ステアリン酸、亜鉛華などの加硫促進助剤、加
硫剤などのゴム用配合剤を通常の範囲内でゴム組成物に
配合することができる。In the foamed rubber composition of the present invention, the foaming agent,
In addition to the vulcanization accelerator, carbon black, aroma oil,
Softeners such as spindle oil, anti-aging agents, other vulcanization accelerators, vulcanization accelerators such as stearic acid and zinc white, and rubber compounding agents such as vulcanizing agents are added to the rubber composition within the usual range. Can be blended.
また、空気発泡ゴム組成物を用いたこの発明の空気入
りタイヤは、この発明の発泡ゴム組成物をトレッドゴム
として用いて通常のタイヤ製造法に従って加熱加圧する
ことによりトレッド部に所定の発泡率で独立気泡を形成
して製造することができる。Further, the pneumatic tire of the present invention using the air-foamed rubber composition, the foamed rubber composition of the present invention is used as a tread rubber, and heated and pressurized in accordance with a normal tire manufacturing method, so that the tread portion has a predetermined foaming rate. It can be manufactured by forming closed cells.
この発明の空気入りタイヤにおいて、発泡率VSは、１
〜100％の範囲であり、好ましくは５〜50％、更に好ま
しくは５〜35％である。発泡率VSが１％未満では、氷雪
性能の改良効果が出ず、また、100％を超えると、耐摩
耗性能が低下し、更に、発泡ゴムの歪み復元力が低下
し、いわゆる耐ヘタリ性が低下することに加え、製造時
に安定した形状を得ることが困難であるからである。ま
た、好ましい例では、トレッドが路面に接する外側トレ
ッド層とこの放射内側トレッド層とから構成され、前記
発泡ゴム層を外側トレッド層に適用する。また、外側ト
レッド層に比較して内側トレッド層のかたさ（JIS硬
度）が高いことが必要である。In the pneumatic tire of the present invention, the foaming ratio V S is 1
-100%, preferably 5-50%, more preferably 5-35%. The expansion ratio V S is less than 1%, not out effect of improving performance on ice and snow, and if it exceeds 100%, abrasion resistance is reduced further, the strain restoring force of the foamed rubber is lowered, so-called permanent set resistance This is because it is difficult to obtain a stable shape at the time of manufacture in addition to the decrease in In a preferred example, the tread is constituted by an outer tread layer in contact with a road surface and the radial inner tread layer, and the foamed rubber layer is applied to the outer tread layer. Further, it is necessary that the hardness (JIS hardness) of the inner tread layer is higher than that of the outer tread layer.
また、この発明の空気入りタイヤにおいて、トレッド
中発泡ゴム組成物よりなる部分がトレッドの全体積の10
％以上の体積を有する必要があり、好ましくは10〜70
％、更に好ましくは40〜60％の体積を有する。10％未満
の体積では氷雪性能の改良効果が少ない。Further, in the pneumatic tire of the present invention, the portion made of the foamed rubber composition in the tread has a total volume of 10% of the tread.
% By volume, preferably 10-70
%, More preferably 40 to 60% by volume. If the volume is less than 10%, the effect of improving ice and snow performance is small.
この発明において、発泡率VSは、次式 VS＝｛（ρ０−ρｇ）／（ρ１−ρｇ）−１｝×100
（％） …（１） で表され、ρ１は発泡ゴムの密度（g/cm3）、ρ０は発
泡ゴムのゴム固相部の密度（g/cm3）、ρｇは発泡ゴム
の気泡内のガム部の密度（g/cm3）である。In the present invention, the foaming ratio V S is expressed by the following equation: V S = {(ρ 0 −ρ g ) / (ρ 1 −ρ g ) −1} × 100
(%) ... is represented by (1), [rho 1 is the density of the foamed rubber (g / cm 3), ρ 0 is the density of the rubber solid phase portion of the foamed rubber (g / cm 3), ρ g is the foamed rubber It is the density (g / cm 3 ) of the gum inside the bubbles.
発泡ゴムはゴム固相部と、ゴム固相部によって形成さ
れる（独立気泡）空洞、すなわち気泡内のガス部とから
構成されている。ガム部の密度ρｇは極めて小さく、ほ
ぼ零に近く、かつ、ゴム固相部の密度ρ０に対して極め
て小さいので、式（１）は、次式 VS＝（ρ０−ρ１−１）×100（％） …（２） とほぼ同等となる。The foamed rubber is composed of a rubber solid phase portion and a cavity (closed cell) formed by the rubber solid phase portion, that is, a gas portion in the bubble. Since the density ρ g of the gum portion is extremely small, almost close to zero, and extremely small with respect to the density ρ 0 of the rubber solid portion, the equation (1) is expressed by the following equation V S = (ρ 0 −ρ 1 −) 1) × 100 (%) ほ ぼ (2)
（実施例） 次に実施例及び比較例によってこの発明を更に詳細に
説明する。(Examples) Next, the present invention will be described in more detail with reference to Examples and Comparative Examples.
実施例１〜4,比較例１〜７ 第１表に示す発泡ゴム組成物を内容量２の小形バン
バリーで混練り、調製した。これらを未放置及び所定時
間放置後150℃の温度、15kg/cm2の圧力で加熱加圧し
て、発泡ゴムを調製し、その際130℃ムーニースコーチ
タイム、スコーチタイムインデックス、130℃発泡開始
までの時間及び発泡率の変化Δ％を測定した。Examples 1 to 4 and Comparative Examples 1 to 7 The foamed rubber compositions shown in Table 1 were kneaded with a small Banbury having an internal volume of 2 and prepared. These were left untouched and left for a predetermined time, then heated and pressurized at a temperature of 150 ° C. and a pressure of 15 kg / cm 2 to prepare foamed rubber, at which time 130 ° C. Mooney scorch time, scorch time index, 130 ° C. until foaming started The change in time and foaming rate Δ% was measured.
発泡ゴムの試験は、下記の方法により行った。 The test of the foamed rubber was performed by the following method.
（イ）発泡率 発泡ゴムの試料を厚さ3mμの薄片にし、加硫後１週間
放置して安定しさた後、密度ρ１（g/cm3）を測定し、
一方無発泡ゴム（固相ゴム）のトレッドの密度ρ０を測
定し、前記式（２）を用いて求めた。(A) Foaming rate A foamed rubber sample is made into a thin piece having a thickness of 3 μm, left for one week after vulcanization to stabilize, and the density ρ 1 (g / cm 3 ) is measured.
On the other hand, the density ρ 0 of the tread of the non-foamed rubber (solid rubber) was measured and determined using the above equation (2).
（ロ）発泡率の変化Δ％ 未加硫ゴムを厚さ7mmのシート状にして40℃、80RHの
状態で４日間放置した後、加硫後の発泡率を測定し、未
放置ゴムの発泡率とを用いて次式により算出する。(B) Change in foaming rate Δ% Unvulcanized rubber is made into a sheet having a thickness of 7 mm and left at 40 ° C. and 80 RH for 4 days. The ratio is calculated using the following equation.
発泡率の変化Δ％＝放置ゴム発泡率（％）− 未放置ゴムの発泡率（％） この値が小さい程安定した発泡率を有する。 Change in foaming rate Δ% = leaved rubber foaming rate (%) − foaming rate of unleaved rubber (%) The smaller this value is, the more stable the foaming rate is.
（ハ）ムーニースコーチタイム JIS K−6300に準じて行った。スコーチタイムインデ
ックスは、比較例２のスコーチタイムを100として指数
表示した。ただし実施例４は比較例７を100として指数
表示した。(C) Mooney scorch time The test was performed according to JIS K-6300. The scorch time index was expressed as an index with the scorch time of Comparative Example 2 being 100. However, in Example 4, the index was indicated by setting Comparative Example 7 to 100.
結果を第１表に示す。 The results are shown in Table 1.
比較例１〜６、実施例１〜３は、天然ゴム系、比較例
７及び実施例４は、合成ゴム系での結果である。Comparative Examples 1 to 6 and Examples 1 to 3 are results of a natural rubber type, and Comparative Examples 7 and 4 are results of a synthetic rubber type.
天然ゴムとポリブタジエンゴムのブレンドにおいて、
比較例１と比較例２で発泡剤としてそれぞれジニトロペ
ンタメチレンテトラミン（発泡剤：尿素＝1:1）とOBSH
を用い加硫促進剤として同じNOBSを用いた場合を比較し
ているが、発泡率の変化Δ％の値がOBSHの場合大幅に小
さい、すなわち発泡率が著しく安定しているという利点
が見られる。しかし、両方ともムーニースコーチタイム
と発泡開始までの時間が短いという欠点がある。OBSHと
加硫促進剤との組合せとして加硫促進剤をスルフェンア
ミド系の中でも遅効性促進剤の中から選び、NOBS（比較
例２）、CZ（比較例３）、NS（比較例４）、DZ（実施例
１）について検討した結果、意外にもDZのみがムーニー
スコーチタイム、発泡開始までの時間がともに大幅に増
し改良されることが分かった。実施例２のようにDZの外
にDMのような合の加硫促進剤を組み合わせてもよい。そ
の場合、DZ対他の加硫促進剤の比は、1/5以上が好まし
く、1/3以上が更に好ましい。比較例５及び比較例６
は、OBSHに組み合わせる加硫促進剤が２種の組合せであ
る場合でもDZを含まない場合にはムーニースコーチタイ
ムと発泡開始までの時間の改善効果がないことを示す。
実施例３は、天然ゴムとスチレンブタジエンゴムとのブ
レンド系でも、OBSHとDZの組合せの効果が見られること
を示す。 In the blend of natural rubber and polybutadiene rubber,
In Comparative Examples 1 and 2, dinitropentamethylenetetramine (foaming agent: urea = 1: 1) and OBSH were used as foaming agents, respectively.
Is compared with the case where the same NOBS is used as a vulcanization accelerator, but the value of the change Δ% of the foaming rate is significantly smaller in the case of OBSH, that is, the advantage that the foaming rate is remarkably stable is seen. . However, both have the disadvantage that the Mooney scorch time and the time until foaming start are short. As a combination of OBSH and a vulcanization accelerator, a vulcanization accelerator is selected from slow-acting accelerators among sulfenamides, and NOBS (Comparative Example 2), CZ (Comparative Example 3), NS (Comparative Example 4) As a result of examining DZ (Example 1), it was found that surprisingly, only DZ was significantly improved in both Mooney scorch time and foaming start time. As in Example 2, a combined vulcanization accelerator such as DM may be combined in addition to DZ. In that case, the ratio of DZ to the other vulcanization accelerator is preferably 1/5 or more, more preferably 1/3 or more. Comparative Example 5 and Comparative Example 6
Indicates that there is no effect of improving the Mooney scorch time and the time until the start of foaming when DZ is not contained even when the vulcanization accelerator combined with OBSH is a combination of two kinds.
Example 3 shows that the effect of the combination of OBSH and DZ is also seen in a blend system of natural rubber and styrene butadiene rubber.
合成ゴム同志のブレンド系であるポリブタジエンゴム
／スチレンブタジエンゴム系でも、実施例４と比較例７
が示すようにOBSHとDZの組合せでは効果があるがOBSHと
DM＋DPGでは効果がない。The polybutadiene rubber / styrene butadiene rubber system, which is a blend of synthetic rubbers, is also used in Example 4 and Comparative Example 7.
As shown, the combination of OBSH and DZ is effective,
No effect with DM + DPG.
（発明の効果） 以上実施例及び比較例で説明したように、ジエン系ゴ
ムよりなるゴム成分に発泡剤としてOBSHを、加硫促進剤
としてDZを配合した発泡ゴム組成物は、押出し温度、未
加硫ゴムの放置環境、放置時間などの製造工程の変動に
対して安定した発泡率、発泡開始時間、スコーチタイム
を有し、したがって安定した物性を与える。この発泡ゴ
ム組成物をトレッドに使用した空気入りタイヤ（スタッ
ドレスタイヤ）は、生産性の低下を伴うことなく、製品
の発泡率のバラツキが著しく改善され、これにより品質
が安定化される。(Effects of the Invention) As described in the above Examples and Comparative Examples, a foamed rubber composition in which OBSH as a foaming agent and DZ as a vulcanization accelerator are blended with a rubber component composed of a diene rubber has an It has stable foaming rate, foaming start time, and scorch time against fluctuations in the manufacturing process such as the vulcanized rubber standing environment and standing time, and thus provides stable physical properties. In a pneumatic tire (studless tire) using the foamed rubber composition for a tread, the variation in the foaming rate of the product is significantly improved without a decrease in productivity, and the quality is thereby stabilized.
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 ＦＩ // Ｂ２９Ｄ 30/52 Ｂ２９Ｄ 30/52 Ｃ０８Ｌ 21:00 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 6 Identification code FI // B29D 30/52 B29D 30/52 C08L 21:00
Claims (3)
ム成分に発泡剤としてp,p′−オキシビス（ベンゼンス
ルホニルヒドラジド）と、加硫促進剤として、N,N−ジ
シクロヘキシル−２−ベンゾチアゾリルスルフェンアミ
ドとを組み合わせて配合したことを特徴とする独立気泡
形成に適する発泡ゴム組成物。1. A rubber component comprising at least one diene rubber, p, p'-oxybis (benzenesulfonylhydrazide) as a foaming agent and N, N-dicyclohexyl-2-benzothiazolyl as a vulcanization accelerator. A foamed rubber composition suitable for forming closed cells characterized by being combined with rusulfenamide.
ビス（ベンゼンスルホニルヒドラジド）１〜20重量部、
N,N−ジシクロヘキシル−２−ベンゾチアゾリルスルフ
ェンアミド0.2〜５重量部を配合する請求項１記載の発
泡ゴム組成物。2. 1 to 20 parts by weight of p, p'-oxybis (benzenesulfonyl hydrazide) per 100 parts by weight of a rubber component.
The foamed rubber composition according to claim 1, further comprising 0.2 to 5 parts by weight of N, N-dicyclohexyl-2-benzothiazolylsulfenamide.
物をトレッドの少なくとも一部に用いた空気入りタイ
ヤ。3. A pneumatic tire using the foamed rubber composition according to claim 1 for at least a part of a tread.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1243300A JP2779227B2 (en) | 1989-09-21 | 1989-09-21 | Foamed rubber composition and pneumatic tire using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1243300A JP2779227B2 (en) | 1989-09-21 | 1989-09-21 | Foamed rubber composition and pneumatic tire using the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03106946A JPH03106946A (en) | 1991-05-07 |
| JP2779227B2 true JP2779227B2 (en) | 1998-07-23 |
Family
ID=17101785
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1243300A Expired - Fee Related JP2779227B2 (en) | 1989-09-21 | 1989-09-21 | Foamed rubber composition and pneumatic tire using the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2779227B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102008050219B4 (en) * | 2007-10-05 | 2020-06-10 | The Yokohama Rubber Co., Ltd. | Rubber composition for tires, manufacture and use of the like and vulcanized composition |
-
1989
- 1989-09-21 JP JP1243300A patent/JP2779227B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03106946A (en) | 1991-05-07 |
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