JP6181431B2 - Pneumatic tire - Google Patents
Pneumatic tire Download PDFInfo
- Publication number
- JP6181431B2 JP6181431B2 JP2013118553A JP2013118553A JP6181431B2 JP 6181431 B2 JP6181431 B2 JP 6181431B2 JP 2013118553 A JP2013118553 A JP 2013118553A JP 2013118553 A JP2013118553 A JP 2013118553A JP 6181431 B2 JP6181431 B2 JP 6181431B2
- Authority
- JP
- Japan
- Prior art keywords
- tread
- pneumatic tire
- rubber layer
- rubber
- tire
- 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.)
- Active
Links
- 229920001971 elastomer Polymers 0.000 claims description 55
- 239000005060 rubber Substances 0.000 claims description 55
- 238000004073 vulcanization Methods 0.000 claims description 32
- 238000005187 foaming Methods 0.000 claims description 16
- 239000000203 mixture Substances 0.000 claims description 15
- 239000004088 foaming agent Substances 0.000 claims description 11
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 claims description 8
- 229920001821 foam rubber Polymers 0.000 claims description 8
- 238000012360 testing method Methods 0.000 claims description 6
- 239000004156 Azodicarbonamide Substances 0.000 claims description 4
- XOZUGNYVDXMRKW-AATRIKPKSA-N azodicarbonamide Chemical group NC(=O)\N=N\C(N)=O XOZUGNYVDXMRKW-AATRIKPKSA-N 0.000 claims description 4
- 235000019399 azodicarbonamide Nutrition 0.000 claims description 4
- 229910000030 sodium bicarbonate Inorganic materials 0.000 claims description 4
- 235000017557 sodium bicarbonate Nutrition 0.000 claims description 4
- -1 4,4′-oxobisbenzenesulfonyl Chemical group 0.000 claims description 3
- MWRWFPQBGSZWNV-UHFFFAOYSA-N Dinitrosopentamethylenetetramine Chemical compound C1N2CN(N=O)CN1CN(N=O)C2 MWRWFPQBGSZWNV-UHFFFAOYSA-N 0.000 claims description 3
- 239000007790 solid phase Substances 0.000 claims description 3
- 239000004636 vulcanized rubber Substances 0.000 claims description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 2
- 239000011324 bead Substances 0.000 claims 1
- 239000010410 layer Substances 0.000 description 17
- 230000000694 effects Effects 0.000 description 12
- 239000005062 Polybutadiene Substances 0.000 description 9
- 229920002857 polybutadiene Polymers 0.000 description 9
- 229920003048 styrene butadiene rubber Polymers 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 8
- 239000002174 Styrene-butadiene Substances 0.000 description 7
- 238000010521 absorption reaction Methods 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 5
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 229910052717 sulfur Inorganic materials 0.000 description 5
- 239000011593 sulfur Substances 0.000 description 5
- OWRCNXZUPFZXOS-UHFFFAOYSA-N 1,3-diphenylguanidine Chemical compound C=1C=CC=CC=1NC(=N)NC1=CC=CC=C1 OWRCNXZUPFZXOS-UHFFFAOYSA-N 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 4
- 229920000459 Nitrile rubber Polymers 0.000 description 3
- 235000021355 Stearic acid Nutrition 0.000 description 3
- 239000000654 additive Substances 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 3
- 229910052782 aluminium Inorganic materials 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 3
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- 239000008117 stearic acid Substances 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- ZRALSGWEFCBTJO-UHFFFAOYSA-N Guanidine Chemical compound NC(N)=N ZRALSGWEFCBTJO-UHFFFAOYSA-N 0.000 description 2
- 244000043261 Hevea brasiliensis Species 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 230000003712 anti-aging effect Effects 0.000 description 2
- 239000006229 carbon black Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000006260 foam Substances 0.000 description 2
- 238000009472 formulation Methods 0.000 description 2
- 229920003049 isoprene rubber Polymers 0.000 description 2
- 229920003052 natural elastomer Polymers 0.000 description 2
- 229920001194 natural rubber Polymers 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 229920001084 poly(chloroprene) Polymers 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 239000013585 weight reducing agent Substances 0.000 description 2
- 239000011787 zinc oxide Substances 0.000 description 2
- ZBKFNNUJJCUVBY-UHFFFAOYSA-N 4-n-butyl-4-n-phenylbenzene-1,4-diamine Chemical compound C=1C=C(N)C=CC=1N(CCCC)C1=CC=CC=C1 ZBKFNNUJJCUVBY-UHFFFAOYSA-N 0.000 description 1
- 239000004604 Blowing Agent Substances 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- CHJJGSNFBQVOTG-UHFFFAOYSA-N N-methyl-guanidine Natural products CNC(N)=N CHJJGSNFBQVOTG-UHFFFAOYSA-N 0.000 description 1
- 239000006057 Non-nutritive feed additive Substances 0.000 description 1
- 229920005683 SIBR Polymers 0.000 description 1
- 239000006087 Silane Coupling Agent Substances 0.000 description 1
- FZWLAAWBMGSTSO-UHFFFAOYSA-N Thiazole Chemical compound C1=CSC=N1 FZWLAAWBMGSTSO-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 1
- 239000010426 asphalt Substances 0.000 description 1
- RTACIUYXLGWTAE-UHFFFAOYSA-N buta-1,3-diene;2-methylbuta-1,3-diene;styrene Chemical compound C=CC=C.CC(=C)C=C.C=CC1=CC=CC=C1 RTACIUYXLGWTAE-UHFFFAOYSA-N 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 229910052570 clay Inorganic materials 0.000 description 1
- 238000013329 compounding Methods 0.000 description 1
- 239000007822 coupling agent Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 229920003244 diene elastomer Polymers 0.000 description 1
- SWSQBOPZIKWTGO-UHFFFAOYSA-N dimethylaminoamidine Natural products CN(C)C(N)=N SWSQBOPZIKWTGO-UHFFFAOYSA-N 0.000 description 1
- 238000002389 environmental scanning electron microscopy Methods 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000010445 mica Substances 0.000 description 1
- 229910052618 mica group Inorganic materials 0.000 description 1
- 239000002480 mineral oil Substances 0.000 description 1
- 235000010446 mineral oil Nutrition 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- DEQZTKGFXNUBJL-UHFFFAOYSA-N n-(1,3-benzothiazol-2-ylsulfanyl)cyclohexanamine Chemical compound C1CCCCC1NSC1=NC2=CC=CC=C2S1 DEQZTKGFXNUBJL-UHFFFAOYSA-N 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 150000001451 organic peroxides Chemical class 0.000 description 1
- 238000013040 rubber vulcanization Methods 0.000 description 1
- 230000001953 sensory effect Effects 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- QAZLUNIWYYOJPC-UHFFFAOYSA-M sulfenamide Chemical compound [Cl-].COC1=C(C)C=[N+]2C3=NC4=CC=C(OC)C=C4N3SCC2=C1C QAZLUNIWYYOJPC-UHFFFAOYSA-M 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- KUAZQDVKQLNFPE-UHFFFAOYSA-N thiram Chemical compound CN(C)C(=S)SSC(=S)N(C)C KUAZQDVKQLNFPE-UHFFFAOYSA-N 0.000 description 1
- 229960002447 thiram Drugs 0.000 description 1
- VTHOKNTVYKTUPI-UHFFFAOYSA-N triethoxy-[3-(3-triethoxysilylpropyltetrasulfanyl)propyl]silane Chemical compound CCO[Si](OCC)(OCC)CCCSSSSCCC[Si](OCC)(OCC)OCC VTHOKNTVYKTUPI-UHFFFAOYSA-N 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Landscapes
- Tyre Moulding (AREA)
- Tires In General (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
Description
本発明は、発泡ゴム層をトレッド部に有する空気入りタイヤに関する。 The present invention relates to a pneumatic tire having a foam rubber layer in a tread portion.
近年、自動車の低燃費化のため、タイヤの軽量化を行うことが要求されているため、タイヤの軽量化の手段として、トレッド部に発泡ゴム層を有する空気入りタイヤが製造、市販されている。トレッド部に使用した発泡ゴムの気泡が、水の膜を取り除き、路面との接地を安定化させる。この発泡ゴムは、ソリッドゴムに熱分解型発泡剤を添加し、加硫することで得ることができ、加硫のための熱源がゴムの外側にあることから、外部から順に加硫が進むことにより、表面部の気泡が細かく、内部の気泡が大きくなる。これは、表面部ではゴムの加硫が発泡より先行することにより粘度が上昇し、気泡の発生が抑制され、内部では発泡が加硫よりも先行するため粘度が低いまま発泡が進行し、気泡が大きく成長できるためである(特許文献1および非特許文献1)。 In recent years, there has been a demand for reducing the weight of tires in order to reduce the fuel consumption of automobiles. As a means for reducing the weight of tires, pneumatic tires having a foamed rubber layer in the tread portion have been manufactured and marketed. . The foamed rubber bubbles used in the tread remove the water film and stabilize the contact with the road surface. This foamed rubber can be obtained by adding a pyrolytic foaming agent to solid rubber and vulcanizing it. Since the heat source for vulcanization is outside the rubber, vulcanization proceeds in order from the outside. As a result, the bubbles on the surface are fine and the bubbles inside are large. This is because the rubber vulcanization precedes foaming at the surface to increase the viscosity, and the generation of bubbles is suppressed. Inside, foaming precedes vulcanization, so the foaming progresses while the viscosity is low. This is because the growth can be greatly increased (Patent Document 1 and Non-Patent Document 1).
しかしながら、表面部の気泡が細かくなって、発泡ゴムの特長である吸水効果による濡れた路面での制動性能(ウエット制動性能)が十分に発揮できないといった問題点がある。また、全体の気泡径を大きくすることは可能であるが、大きな気泡径はゴムの貯蔵弾性率G’を低下させるため、高速走行するにあたって十分な操縦安定性を確保することが困難である。 However, there is a problem that the air bubbles in the surface portion become fine and the braking performance (wet braking performance) on the wet road surface due to the water absorption effect that is a feature of the foamed rubber cannot be sufficiently exhibited. Although it is possible to increase the overall bubble diameter, a large bubble diameter lowers the storage elastic modulus G ′ of the rubber, so that it is difficult to ensure sufficient steering stability when traveling at high speed.
また、特許文献2には、内側部分よりも、外側部分の発泡率が高いトレッドゴムが開示されている。しかしながら、タイヤ半径方向の外側を内側よりも高い温度で加熱し発泡させるものである。したがって、外側部分に細かい気泡が多数存在し、ウエット制動性能が十分に発揮できないという問題点がある。 Patent Document 2 discloses a tread rubber having a higher expansion ratio in the outer portion than in the inner portion. However, the outer side in the tire radial direction is heated and foamed at a higher temperature than the inner side. Therefore, there are a number of fine bubbles in the outer portion, and there is a problem that the wet braking performance cannot be sufficiently exhibited.
本発明は、発泡による軽量化効果を損なうことなく、吸水によるウエット制動性能、操縦安定性を高度に両立できる空気入りタイヤを提供することを目的とする。 An object of the present invention is to provide a pneumatic tire that can achieve both high wet braking performance and water handling stability due to water absorption without impairing the weight reduction effect due to foaming.
本発明者らは、タイヤのトレッド部に発泡ゴム層を有するタイヤについて検討したところ、発泡ゴム層の表面部の平均気泡径を大きくし、内部の平均気泡径を小さくすれば、軽量化を確保したうえで、吸水性によるウエット制動性能、操縦安定性を高い次元で両立できることを見出し、本発明を完成した。 The present inventors examined a tire having a foamed rubber layer in the tread portion of the tire. As a result, the weight of the foam was ensured by increasing the average bubble diameter of the surface portion of the foamed rubber layer and decreasing the average bubble diameter inside. In addition, the present inventors have found that wet braking performance by water absorption and steering stability can be achieved at a high level, and the present invention has been completed.
すなわち、本発明は、発泡ゴム層をトレッド部に用いた空気入りタイヤであって、発泡ゴム層のトレッド内部の平均気泡径が、トレッド表面部よりも小さいことを特徴とする空気入りタイヤに関する。 That is, the present invention relates to a pneumatic tire using a foam rubber layer in a tread portion, wherein the average cell diameter inside the tread of the foam rubber layer is smaller than the tread surface portion.
発泡ゴム層の気泡の平均気泡径が、トレッド表面部では40〜100μm、内部では5〜40μmであることが好ましい。 The average bubble diameter of the foamed rubber layer is preferably 40 to 100 μm at the tread surface and 5 to 40 μm inside.
トレッド表面部がタイヤ表面から中心方向に5〜10mm、トレッド内部が表面部最下部から中心方向に1〜7.5mmであることが好ましい。 The tread surface portion is preferably 5 to 10 mm in the center direction from the tire surface, and the inside of the tread is preferably 1 to 7.5 mm in the center direction from the lowermost portion of the surface portion.
加硫工程における加硫圧力が、1.4〜5.0MPaであることが好ましい。 The vulcanization pressure in the vulcanization step is preferably 1.4 to 5.0 MPa.
発泡ゴム層に使用するゴム組成物が、160℃における加硫速度曲線(JIS K 6300「未加硫ゴムの試験方法」に準じる)のトルクの最小値(ML)と最大値(MH)の差(MH−ML)をMEとしたときの、ML+0.1MEに到達する時間t10(分)が2.5分より遅いことが好ましい。 The difference between the minimum value (ML) and the maximum value (MH) of the torque of the vulcanization rate curve at 160 ° C. (according to JIS K 6300 “Testing method for unvulcanized rubber”) of the rubber composition used for the foam rubber layer When (MH−ML) is ME, it is preferable that time t10 (minute) to reach ML + 0.1ME is slower than 2.5 minutes.
上記発泡ゴムが熱分解型発泡剤を用いて製造されることが好ましい。 The foamed rubber is preferably produced using a pyrolytic foaming agent.
前記発泡剤が、アゾジカルボンアミド、N,N’−ジニトロソペンタメチレンテトラミン、4,4’−オキソビスベンゼンスルホニルヒドラジド、または、炭酸水素ナトリウムであることが好ましい。 The foaming agent is preferably azodicarbonamide, N, N′-dinitrosopentamethylenetetramine, 4,4′-oxobisbenzenesulfonyl hydrazide, or sodium bicarbonate.
前記発泡ゴム層の表面部および内部を総合した下記式:
発泡率=(加硫ゴムにおける固相部の密度/加硫ゴムの密度−1)×100%
で計算される発泡率が10〜50%であることが好ましい。
The following formula summarizing the surface portion and the inside of the foamed rubber layer:
Foaming rate = (density of solid phase in vulcanized rubber / density of vulcanized rubber−1) × 100%
It is preferable that the foaming rate calculated by is 10 to 50%.
本発明によれば、発泡ゴム層の発泡の平均気泡径を、トレッド表面部よりトレッド内部のほうを小さくすることによって、吸水性を確保することができ、濡れた路面での制動距離(ウエット制動距離)を短くすることができる。また、内部の気泡を微細気泡にすることで、貯蔵弾性率G’の低下を抑えることができ、高速走行での操縦安定性を確保することができる。 According to the present invention, the average bubble diameter of the foamed rubber layer can be ensured by making the inside of the tread smaller than the surface of the tread, so that water absorption can be secured, and the braking distance (wet braking on a wet road surface) can be ensured. Distance) can be shortened. In addition, by making the internal bubbles fine, it is possible to suppress a decrease in the storage elastic modulus G ′ and to ensure steering stability at high speeds.
本発明の空気入りタイヤは、発泡ゴム層をトレッド部に用いた空気入りタイヤであって、発泡ゴム層のトレッド内部の平均気泡径が、トレッド表面部よりトレッド内部のほうが小さいことを特徴とする。 The pneumatic tire of the present invention is a pneumatic tire using a foamed rubber layer in a tread portion, wherein the average cell diameter inside the tread of the foamed rubber layer is smaller in the tread surface portion than in the tread surface portion. .
トレッド部に用いた発泡ゴム層の平均気泡径は、トレッド表面部では40〜100μmが好ましく、50〜70μmがより好ましい。40μm未満では、十分な吸水効果が得られず、濡れた路面での制動性能が十分に得られにくくなる傾向がある。平均気泡径が100μmを超えると、耐摩耗性が悪化し、夏用タイヤとしての摩耗性能を確保できなくなる傾向がある。一方、トレッド内部では5〜40μmが好ましく、20〜40μmがより好ましい。40μmを超えると、貯蔵弾性率G’が低下し、十分な操縦安定性が確保できなくなる傾向がある。5μm未満では、発泡率が小さくなり、十分な軽量化効果を得ることができにくくなる傾向がある。 The average cell diameter of the foamed rubber layer used for the tread portion is preferably 40 to 100 μm and more preferably 50 to 70 μm at the tread surface portion. If it is less than 40 μm, a sufficient water absorption effect cannot be obtained, and the braking performance on wet road surfaces tends to be difficult to obtain sufficiently. When the average cell diameter exceeds 100 μm, the wear resistance tends to deteriorate, and the wear performance as a summer tire tends to be unable to be ensured. On the other hand, 5-40 micrometers is preferable inside a tread, and 20-40 micrometers is more preferable. If it exceeds 40 μm, the storage elastic modulus G ′ tends to decrease and sufficient steering stability cannot be ensured. If it is less than 5 μm, the foaming rate tends to be small and it becomes difficult to obtain a sufficient lightening effect.
ここで、トレッド表面部とはタイヤ表面から中心方向に5〜10mm、トレッド内部とは表面部最下部からタイヤ中心方向に1〜7.5mmの部位であることが好ましい。表面部の厚みが5mm未満であると、走行による摩耗により、内部の微細気泡が早期に現れ、十分な制動距離を得ることができなくなる傾向にある。また、トレッド表面部の厚みが10mmを超え、かつ/または、内部層の厚みが1mm未満では、走行するにあたり、十分な操縦安定性を確保することができなくなる傾向にある。そして、内部の厚みが10mm以上となると、表面層厚さを確保できず、十分な軽量化効果を得ることができなくなる傾向にある。 Here, it is preferable that the tread surface portion is a portion of 5 to 10 mm in the center direction from the tire surface, and the inside of the tread is a portion of 1 to 7.5 mm in the tire center direction from the lowermost portion of the surface portion. If the thickness of the surface portion is less than 5 mm, the internal fine bubbles appear early due to wear caused by running, and there is a tendency that a sufficient braking distance cannot be obtained. Moreover, when the thickness of the tread surface portion exceeds 10 mm and / or the thickness of the inner layer is less than 1 mm, sufficient steering stability tends to be unable to be ensured when traveling. And when the internal thickness is 10 mm or more, the surface layer thickness cannot be secured, and there is a tendency that a sufficient lightening effect cannot be obtained.
所望のトレッド表面部の平均気泡径を得るために、発泡ゴム層を形成するゴム組成物において、160℃における加硫速度曲線(JIS K 6300「未加硫ゴムの試験方法」に準じる)のトルクの最小値(ML)と最大値(MH)の差(MH−ML)をMEとしたときの、ML+0.1MEに到達する時間(スコーチタイム)t10(分)が、2.5〜3.5分が好ましく、2.8〜3.2分がより好ましい。t10を2.5分以上にすると、加硫が開始し粘度が上昇するまでに発泡反応を開始させ、表面部の気泡を大きくすることができる。t10が2.5分未満であると、加硫が発泡よりも早く起こるため、表面部に大粒径の気泡を得ることができなくなる傾向がある。また、t10を3.5分以下にすることで、生産性を確保することができ、3.5分を超えると、生産性が落ちる傾向にある。 In order to obtain the desired average cell diameter of the tread surface portion, the torque of the vulcanization rate curve at 160 ° C. (according to JIS K 6300 “Testing method for unvulcanized rubber”) in the rubber composition forming the foam rubber layer When the difference (MH−ML) between the minimum value (ML) and the maximum value (MH) is set to ME, the time (scorch time) t10 (minute) to reach ML + 0.1ME is 2.5 to 3.5. Minute is preferable, and 2.8 to 3.2 minutes is more preferable. When t10 is 2.5 minutes or more, the foaming reaction is started before the vulcanization starts and the viscosity increases, and the bubbles on the surface portion can be enlarged. When t10 is less than 2.5 minutes, vulcanization occurs earlier than foaming, and thus there is a tendency that bubbles having a large particle diameter cannot be obtained on the surface portion. Moreover, productivity can be ensured by making t10 into 3.5 minutes or less, and when it exceeds 3.5 minutes, there exists a tendency for productivity to fall.
スコーチタイムt10は、たとえば加硫促進剤である1,3−ジフェニルグアニジン(ノクセラーD)の配合量によって制御することができる。スコーチタイムt10を2.5〜3.5分にするには、たとえば、1,3−ジフェニルグアニジン(ノクセラーD)をゴム成分100質量部に対して、好ましくは0.1〜1.0質量部、より好ましくは0.2〜0.8質量部配合すればよい。 The scorch time t10 can be controlled by, for example, the amount of 1,3-diphenylguanidine (Noxeller D) that is a vulcanization accelerator. In order to adjust the scorch time t10 to 2.5 to 3.5 minutes, for example, 1,3-diphenylguanidine (Noxeller D) is preferably 0.1 to 1.0 part by mass with respect to 100 parts by mass of the rubber component. More preferably, 0.2 to 0.8 parts by mass may be blended.
さらに、所望のトレッド内部の平均気泡径を得るために、タイヤ用ゴム組成物の加硫工程において、加硫圧力を1.4〜5.0MPaにすることが好ましく、1.5〜3.0MPaがより好ましい。加硫圧力を1.4MPa以上にすることで、内部における気泡成長を抑制することができ、かつ、内部の熱周りが表面部よりも遅いことから、加硫反応が発泡よりも先行し、微細な気泡を生成させることができる。加硫圧力が1.4MPa未満であると、この気泡成長抑制の効果が十分でなく、内部でも大粒径の気泡が発生し、所望の気泡構造を得ることができない。ただし、加硫圧力が5.0MPaを超えると、金型にかかる圧力が高くなり、金型が圧力に耐え切れず安全上の問題が起こり易くなる傾向にある。
加硫温度は特に限定されないが、140〜180℃が好ましく、150〜170℃がより好ましい。
Furthermore, in order to obtain a desired average cell diameter inside the tread, in the vulcanization step of the rubber composition for a tire, the vulcanization pressure is preferably 1.4 to 5.0 MPa, and preferably 1.5 to 3.0 MPa. Is more preferable. By setting the vulcanization pressure to 1.4 MPa or more, it is possible to suppress bubble growth inside, and since the internal heat is slower than the surface portion, the vulcanization reaction precedes foaming and is fine. Bubbles can be generated. When the vulcanization pressure is less than 1.4 MPa, the effect of suppressing the bubble growth is not sufficient, and bubbles having a large particle diameter are generated inside, and a desired cell structure cannot be obtained. However, when the vulcanization pressure exceeds 5.0 MPa, the pressure applied to the mold increases, and the mold cannot withstand the pressure, and there is a tendency that a safety problem is likely to occur.
Although a vulcanization temperature is not specifically limited, 140-180 degreeC is preferable and 150-170 degreeC is more preferable.
発泡ゴム層は、熱分解型発泡剤を用いて製造することが好ましい。熱分解型発泡剤は、不活性ガスなどによるマイクロセルラーなどの発泡剤と比べ、加硫後のゴム組成物の物性に影響を与える残滓を生じ難いので、物性に悪影響を与え難いという特徴がある。 The foamed rubber layer is preferably produced using a pyrolytic foaming agent. Thermally decomposable foaming agents are less likely to produce residues that affect the physical properties of the rubber composition after vulcanization, as compared to foaming agents such as micro-cellular using inert gas. .
熱分解型発泡剤としては、とくに限定されないが、たとえばアゾジカルボンアミド、N,N’−ジニトロソペンタメチレンテトラミン、4,4’−オキソビスベンゼンスルホニルヒドラジド、炭酸水素ナトリウムなどが挙げられる。とくに、アゾジカルボンアミド、4,4’−オキソビスベンゼンスルホニルヒドラジド、および炭酸水素ナトリウムでは、加硫後のゴム組成物の物性に影響を与える残滓を生じ難くする傾向がある。これらの発泡剤は単独でも、複数のものを組み合わせて使用することもできる。 The pyrolytic foaming agent is not particularly limited, and examples thereof include azodicarbonamide, N, N′-dinitrosopentamethylenetetramine, 4,4′-oxobisbenzenesulfonylhydrazide, sodium hydrogen carbonate and the like. In particular, azodicarbonamide, 4,4'-oxobisbenzenesulfonyl hydrazide, and sodium hydrogen carbonate tend to make it difficult to produce a residue that affects the physical properties of the rubber composition after vulcanization. These foaming agents can be used alone or in combination.
熱分解型発泡剤の配合量は、とくに限定されないが、ゴム成分100質量部に対して3〜8質量部が好ましく、4〜7質量部がより好ましい。8質量部を超えると、発泡倍率が50%を超え、3質量部未満では、発泡倍率が10%未満となる傾向がある。 Although the compounding quantity of a thermal decomposition type foaming agent is not specifically limited, 3-8 mass parts is preferable with respect to 100 mass parts of rubber components, and 4-7 mass parts is more preferable. If it exceeds 8 parts by mass, the expansion ratio exceeds 50%, and if it is less than 3 parts by mass, the expansion ratio tends to be less than 10%.
前記発泡ゴムの表面部および内部を総合した下記式:
発泡率=(加硫ゴムにおける固相部の密度/加硫ゴムの密度−1)×100%
で算出される発泡率が10〜50%であることが好ましく、20〜40%であることがより好ましい。発泡率が10〜50%であることで、軽量化と操縦安定性、耐摩耗性、および耐久性とを、両立することができる。一方、発泡率が10%未満であると、軽量化の効果が小さくなり、50%を超えると、操縦安定性、耐摩耗性、および耐久性が低下する傾向がある。
The following formula that combines the surface and the inside of the foam rubber:
Foaming rate = (density of solid phase in vulcanized rubber / density of vulcanized rubber−1) × 100%
Is preferably 10 to 50%, more preferably 20 to 40%. When the foaming rate is 10 to 50%, it is possible to achieve both weight reduction and steering stability, wear resistance, and durability. On the other hand, when the foaming ratio is less than 10%, the effect of reducing the weight is reduced, and when it exceeds 50%, steering stability, wear resistance, and durability tend to be lowered.
本発明で使用するゴム組成物が含有するゴム成分としては特に限定されず、例えば、天然ゴム(NR)、イソプレンゴム(IR)、スチレンブタジエンゴム(SBR)、ブタジエンゴム(BR)、スチレンイソプレンブタジエンゴム(SIBR)、クロロプレンゴム(CR)、アクリロニトリルブタジエンゴム(NBR)などのジエン系ゴムが挙げられる。これらは単独で用いてもよいし、2種以上を併用してもよい。なかでも、耐亀裂成長性の改善効果が高いという点から、SBR、BRが好ましく、SBR及びBRの併用がより好ましい。 The rubber component contained in the rubber composition used in the present invention is not particularly limited. For example, natural rubber (NR), isoprene rubber (IR), styrene butadiene rubber (SBR), butadiene rubber (BR), styrene isoprene butadiene. Examples include diene rubbers such as rubber (SIBR), chloroprene rubber (CR), and acrylonitrile butadiene rubber (NBR). These may be used alone or in combination of two or more. Among these, SBR and BR are preferable because the effect of improving crack growth resistance is high, and the combined use of SBR and BR is more preferable.
SBR、BRとしては特に限定されず、タイヤ工業において一般的なものを使用できる。 SBR and BR are not particularly limited, and those common in the tire industry can be used.
ゴム成分100質量%中のSBRの含有量は、好ましくは30質量%以上、より好ましくは45質量%以上、更に好ましくは55質量%以上である。また、SBRの含有量は、100質量%であってもよいが、好ましくは90質量%以下である。上記範囲内であれば、本発明の効果が良好に得られる。 The content of SBR in 100% by mass of the rubber component is preferably 30% by mass or more, more preferably 45% by mass or more, and further preferably 55% by mass or more. Further, the SBR content may be 100% by mass, but is preferably 90% by mass or less. If it is in the said range, the effect of this invention will be acquired favorably.
ゴム成分100質量%中のBRの含有量は、好ましくは10質量%以上、より好ましくは15質量%以上である。また、BRの含有量は、好ましくは70質量%以下、より好ましくは55質量%以下、更に好ましくは45質量%以下である。上記範囲内であれば、本発明の効果が良好に得られる。 The content of BR in 100% by mass of the rubber component is preferably 10% by mass or more, more preferably 15% by mass or more. The BR content is preferably 70% by mass or less, more preferably 55% by mass or less, and still more preferably 45% by mass or less. If it is in the said range, the effect of this invention will be acquired favorably.
ゴム成分100質量%中のSBR及びBRの合計含有量は、好ましくは60質量%以上、より好ましくは80質量%以上、更に好ましくは90質量%以上であり、100質量%であってもよい。上記範囲内であれば、本発明の効果が良好に得られる。 The total content of SBR and BR in 100% by mass of the rubber component is preferably 60% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and may be 100% by mass. If it is in the said range, the effect of this invention will be acquired favorably.
本発明に使用するゴム組成物は、ゴム成分以外にゴム組成物の製造に一般に使用される添加剤を適宜配合することができる。添加剤としては、公知のものを用いることができ、硫黄などの加硫剤;チアゾール系加硫促進剤、チウラム系加硫促進剤、スルフェンアミド系加硫促進剤、グアニジン系加硫促進剤などの加硫促進剤;ステアリン酸、酸化亜鉛などの加硫活性化剤;有機過酸化物;カーボンブラック、シリカ、炭酸カルシウム、タルク、アルミナ、クレー、水酸化アルミニウム、マイカなどの充填剤;伸展油、滑剤などの加工助剤;老化防止剤;カップリング剤を例示することができる。 In addition to the rubber component, the rubber composition used in the present invention can be appropriately blended with additives generally used in the production of rubber compositions. Known additives can be used, such as sulfur vulcanizing agents; thiazole vulcanization accelerators, thiuram vulcanization accelerators, sulfenamide vulcanization accelerators, guanidine vulcanization accelerators. Vulcanization accelerators such as stearic acid and zinc oxide; organic peroxides; fillers such as carbon black, silica, calcium carbonate, talc, alumina, clay, aluminum hydroxide, mica; Examples thereof include processing aids such as oils and lubricants; anti-aging agents; and coupling agents.
発泡の形状については、とくに限定されるものではない。発泡ゴム層のトレッド内部の平均気泡径が、トレッド表面部よりも小さいことによって、操縦安定性が要求される夏用タイヤにも適用することができるようになり、また、発泡の吸水効果により、多少の雪道であれば走行可能となる。 The shape of the foam is not particularly limited. Since the average cell diameter inside the tread of the foam rubber layer is smaller than the tread surface part, it can be applied to summer tires that require steering stability, and due to the water absorption effect of foaming, It can be run on some snowy roads.
本発明の空気入りタイヤは、ゴム組成物を用いて通常の方法によって製造される。すなわち、必要に応じてゴム成分に各種添加剤を配合したゴム組成物を、未加硫の段階でタイヤのトレッドの形状に合わせて押し出し加工する。タイヤ成型機上にて通常の方法にて成形し、トレッド部材を、他のタイヤ部材とともに貼り合わせ、未加硫タイヤを形成する。この未加硫タイヤを加硫機中で加熱加圧して発泡させ、本発明の空気入りタイヤを製造することができる。 The pneumatic tire of the present invention is produced by a usual method using a rubber composition. That is, if necessary, a rubber composition in which various additives are blended with a rubber component is extruded in accordance with the shape of the tire tread at an unvulcanized stage. The tire is molded by a normal method on a tire molding machine, and the tread member is bonded together with other tire members to form an unvulcanized tire. This unvulcanized tire can be heated and pressurized in a vulcanizer to be foamed to produce the pneumatic tire of the present invention.
実施例に基づいて、本発明を具体的に説明するが、本発明はこれらのみに限定されるものではない。 The present invention will be specifically described based on examples, but the present invention is not limited to these examples.
以下に実施例及び比較例で用いた各種薬品について、まとめて説明する。
SBR:日本ゼオン(株)製のNipol 1502(スチレン量:23.5質量%) 80質量部
BR:宇部興産(株)製のハイシスBR150B 20質量部
カーボンブラック:キャボットジャパン(株)製のショウブラックN220(チッ素吸着比表面積(N2SA):125m2/g) 20質量部
シリカ:デグッサ社製のウルトラシルVN3(チッ素吸着比表面積(N2SA):175m2/g) 80質量部
シランカップリング剤:デグッサ社製のSi69(ビス(3−トリエトキシシリルプロピル)テトラスルフィド) 5質量部
老化防止剤:大内新興化学工業(株)製のノクラック6C(N−1,3−ジメチルブチル−N’−フェニル−p−フェニレンジアミン) 3質量部
ステアリン酸:日油(株)製のステアリン酸 5質量部
オイル:出光興産(株)製のミネラルオイルPW−380 10質量部
酸化亜鉛:三井金属鉱業(株)製の亜鉛華1号 2質量部
ワックス:大内新興化学工業(株)製のサンノックワックス 2質量部
硫黄:鶴見化学工業(株)製の粉末硫黄 2質量部
加硫促進剤1:大内新興化学工業(株)製のノクセラーD(1,3−ジフェニルグアニジン) 0.1〜1.5質量部
加硫促進剤2:大内新興化学工業(株)製のノクセラーCZ(N−シクロヘキシル−2−ベンゾチアゾリルスルフェンアミド) 2質量部
発泡剤:永和化成工業(株)製のネオセルボンN#1000SW(4,4’−オキソビスベンゼンスルホニルヒドラジド、平均粒径14μm) 5質量部
Hereinafter, various chemicals used in Examples and Comparative Examples will be described together.
SBR: Nipol 1502 manufactured by Nippon Zeon Co., Ltd. (styrene amount: 23.5% by mass) 80 parts by mass BR: Hisys BR150B manufactured by Ube Industries, Ltd. 20 parts by mass Carbon black: Show black manufactured by Cabot Japan Co., Ltd. N220 (nitrogen adsorption specific surface area (N 2 SA): 125 m 2 / g) 20 parts by mass Silica: Ultrasil VN3 (nitrogen adsorption specific surface area (N 2 SA): 175 m 2 / g) manufactured by Degussa Co. 80 parts by mass Silane coupling agent: Si69 (bis (3-triethoxysilylpropyl) tetrasulfide) manufactured by Degussa, Inc. 5 parts by mass anti-aging agent: NOCRACK 6C (N-1,3-dimethyl, manufactured by Ouchi Shinsei Chemical Co., Ltd.) Butyl-N′-phenyl-p-phenylenediamine) 3 parts by mass Stearic acid: 5 parts by mass of stearic acid manufactured by NOF Corporation Il: Mineral oil PW-380 manufactured by Idemitsu Kosan Co., Ltd. 10 parts by mass Zinc oxide: Zinc flower No. 1 manufactured by Mitsui Mining & Smelting Co., Ltd. 2 parts by weight Wax: Sunnock wax manufactured by Ouchi Shinsei Chemical Co., Ltd. 2 parts by mass sulfur: powdered sulfur produced by Tsurumi Chemical Industry Co., Ltd. 2 parts by mass vulcanization accelerator 1: Noxeller D (1,3-diphenylguanidine) produced by Ouchi Shinsei Chemical Industry Co., Ltd. 0.1-1. 5 parts by mass vulcanization accelerator 2: Noxeller CZ (N-cyclohexyl-2-benzothiazolylsulfenamide) manufactured by Ouchi Shinsei Chemical Co., Ltd. 2 parts by mass blowing agent: Neocerbon manufactured by Eiwa Kasei Kogyo Co., Ltd. N # 1000SW (4,4′-oxobisbenzenesulfonylhydrazide, average particle size 14 μm) 5 parts by mass
(実施例1〜12および比較例1〜2)
表1および2に示すジフェニルグアニジンの配合量に従って1.7Lバンバリーミキサーを用いて、硫黄及び加硫促進剤以外の材料を150℃の条件下で3分間混練りし、混練り物を得た。次に、得られた混練り物に硫黄及び加硫促進剤を添加し、オープンロールを用いて、50℃の条件下で5分間練り込み、未加硫ゴム組成物を得た。
得られた未加硫ゴム組成物を、表1および2に示す加硫圧力でトレッド形状に成形して、他のタイヤ部材と貼り合わせ、170℃で15分間加硫することにより、各実施例および比較例のタイヤ(タイヤサイズ 195/65R15)を作製した。得られたタイヤを用いて、以下の評価を行った。評価結果を表1および2に示す。
(Examples 1-12 and Comparative Examples 1-2)
According to the blending amount of diphenylguanidine shown in Tables 1 and 2, materials other than sulfur and a vulcanization accelerator were kneaded for 3 minutes at 150 ° C. using a 1.7 L Banbury mixer to obtain a kneaded product. Next, sulfur and a vulcanization accelerator were added to the obtained kneaded product, and kneaded for 5 minutes at 50 ° C. using an open roll to obtain an unvulcanized rubber composition.
The obtained unvulcanized rubber composition was formed into a tread shape at the vulcanization pressure shown in Tables 1 and 2, and bonded to other tire members, and vulcanized at 170 ° C. for 15 minutes, whereby each example. And the tire (tire size 195 / 65R15) of the comparative example was produced. The following evaluation was performed using the obtained tire. The evaluation results are shown in Tables 1 and 2.
<平均気泡粒径>
得られたタイヤよりトレッドのブロックを切り出し、厚み方向にスライスしたものを、走査型電子顕微鏡(Scanning Electron Microscope:SEM/フィリップ社製XL30 ESEM)で気泡を観察した。観察した気泡の直径を気泡径とし、1mm×1mmの範囲内にある全ての気泡について、円相当径を算出し、全ての円相当径の算術平均値を算出することで、トレッド表面部および内部それぞれで平均気泡粒径を測定した。
<Average cell diameter>
From the obtained tire, a tread block was cut out and sliced in the thickness direction, and bubbles were observed with a scanning electron microscope (Scanning Electron Microscope: SEM / XL 30 ESEM manufactured by Philippe). The diameter of the observed bubble is taken as the bubble diameter, and for all the bubbles in the range of 1 mm × 1 mm, the equivalent circle diameter is calculated, and the arithmetic average value of all the equivalent circle diameters is calculated. The average bubble diameter was measured for each.
<操縦安定性>
得られたタイヤを15×6JJのアルミホイールリムにリム組みし、かつ内圧210kPa(前後同一)を充填して、排気量2000ccの国産FF車の4輪に装着するとともに、テストコース内をドライバー1名乗車で走行して官能評価した。実施例1を100とする指数で評価した。数値が大きいほど良好である。
<Steering stability>
The resulting tire is assembled on a 15 x 6 JJ aluminum wheel rim, filled with internal pressure 210 kPa (same front and rear), mounted on four wheels of a 2000cc domestic FF vehicle, and driver 1 in the test course I drove with a passenger car and made a sensory evaluation. Example 1 was evaluated with an index of 100. The larger the value, the better.
<ウエット制動性能>
得られたタイヤを15×6JJのアルミホイールリムにリム組みし、かつ内圧210kPa(前後同一)を充填して、排気量2000ccの国産FF車の4輪に装着するとともに、テストコース内をドライバー1名で、湿潤アスファルト路面にて、初速度100km/hからの制動距離を測定した。そして、実施例1のウェットグリップ性能指数を100とする指数で評価した。評価は、以下に示す計算式により、各配合のウエット制動性能(ウエットグリップ性能)を指数表示した。数値が大きいほどウェット制動性能に優れることを示す。
(ウェット制動性能指数)=(実施例1の制動距離)/(各配合の制動距離)×100
<Wet braking performance>
The resulting tire is assembled on a 15 x 6 JJ aluminum wheel rim, filled with internal pressure 210 kPa (same front and rear), mounted on four wheels of a 2000cc domestic FF vehicle, and driver 1 in the test course By name, the braking distance from an initial speed of 100 km / h was measured on a wet asphalt road surface. And it evaluated by the index | exponent which sets the wet grip performance index | exponent of Example 1 to 100. FIG. In the evaluation, the wet braking performance (wet grip performance) of each formulation was displayed as an index according to the following formula. Larger values indicate better wet braking performance.
(Wet braking performance index) = (Brake distance of Example 1) / (Brake distance of each formulation) × 100
<耐摩耗性>
得られたタイヤを15×6JJのアルミホイールリムにリム組みし、かつ内圧210kPa(前後同一)を充填して、排気量2000ccの国産FF車の4輪自動車に装着し、一般道を走行した後、6ヶ月後の残溝を計測し、実施例1を100とする100点法で指数にて著した。数値が大きいほど良好である。
<Abrasion resistance>
After the tire was assembled on a 15x6 JJ aluminum wheel rim and filled with an internal pressure of 210 kPa (same front and rear), mounted on a four-wheeled vehicle with a 2000cc domestic FF car and running on a general road The remaining groove after 6 months was measured, and it was written as an index by a 100-point method with Example 1 as 100. The larger the value, the better.
<重量>
供試タイヤを水平な状態に固定した重量計に乗せ測定した。実施例1を100としたときの指数で示す。数値が大きいほど軽量化できており、良好である。
重量指数=実施例1の重量/各実施例または比較例の重量×100%
<Weight>
The test tire was measured on a weighing scale fixed in a horizontal state. It shows with an index when Example 1 is set to 100. The larger the value, the better the weight and the better.
Weight index = weight of Example 1 / weight of each Example or Comparative Example × 100%
実施例1〜12のタイヤでは比較例1および2のタイヤと比較して、操縦安定性およびウエット制動性能において高い次元で発揮できている。とくに、実施例1〜7のタイヤでは、耐摩耗性および重量においても高い次元で発揮できている。
In the tires of Examples 1 to 12, compared with the tires of Comparative Examples 1 and 2, the steering stability and wet braking performance can be exhibited at a higher level. Particularly, in the tires of Examples 1 to 7, the wear resistance and the weight can be exhibited at a high level.
Claims (8)
(但し、環状に形成されたトレッド部と、該トレッド部の両側に連なる一対のサイドウォール部およびビード部とを有する空気入りタイヤであって、前記トレッド部が、踏面部に複数のブロック列を含むトレッドパターンを有し、かつ、タイヤ半径方向外側からキャップゴム層とベースゴム層とを積層してなる二層構造を有する空気入りタイヤにおいて、前記ブロックが、タイヤ軸方向に対し傾きを持って、ショルダー部両側区域においては周方向隣接ブロック間で互いに略並行に、タイヤ幅方向に延びる複数本のサイプを有し、前記キャップゴム層がアルミナ入り筒状独立気泡を、前記ベースゴム層が球状独立気泡を、それぞれ含み、かつ、該ベースゴム層のショアA硬度が、該キャップゴム層のショアA硬度より大きいことを特徴とする空気入りタイヤを除く。) A pneumatic tire using a foamed rubber layer in a tread portion, wherein an average cell diameter inside the tread of the foamed rubber layer is smaller than a tread surface portion.
(However, it is a pneumatic tire having an annularly formed tread portion and a pair of sidewall portions and bead portions connected to both sides of the tread portion, wherein the tread portion has a plurality of block rows on the tread portion. In a pneumatic tire having a tread pattern including and having a two-layer structure in which a cap rubber layer and a base rubber layer are laminated from the outside in the tire radial direction, the block has an inclination with respect to the tire axial direction. In the both sides of the shoulder portion, there are a plurality of sipes extending in the tire width direction substantially parallel to each other between adjacent blocks in the circumferential direction, the cap rubber layer is cylindrical closed cells containing alumina, and the base rubber layer is spherical Each of which contains closed cells, and the Shore A hardness of the base rubber layer is larger than the Shore A hardness of the cap rubber layer. Except for the pneumatic tire.)
発泡率=(加硫ゴムにおける固相部の密度/加硫ゴムの密度−1)×100%
で計算される発泡率が10〜50%であることを特徴とする、請求項1〜7のいずれかに記載の空気入りタイヤ。
The following formula summarizing the surface portion and the inside of the foamed rubber layer:
Foaming rate = (density of solid phase in vulcanized rubber / density of vulcanized rubber−1) × 100%
The pneumatic tire according to any one of claims 1 to 7, wherein the foaming ratio calculated by the formula (1) is 10 to 50%.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2013118553A JP6181431B2 (en) | 2013-06-05 | 2013-06-05 | Pneumatic tire |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2013118553A JP6181431B2 (en) | 2013-06-05 | 2013-06-05 | Pneumatic tire |
Publications (2)
Publication Number | Publication Date |
---|---|
JP2014234127A JP2014234127A (en) | 2014-12-15 |
JP6181431B2 true JP6181431B2 (en) | 2017-08-16 |
Family
ID=52137131
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2013118553A Active JP6181431B2 (en) | 2013-06-05 | 2013-06-05 | Pneumatic tire |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP6181431B2 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2019117293A1 (en) * | 2017-12-14 | 2019-06-20 | 株式会社ブリヂストン | Tire |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3360921B2 (en) * | 1994-03-25 | 2003-01-07 | 株式会社ブリヂストン | Pneumatic tire |
JP2003292667A (en) * | 2002-03-29 | 2003-10-15 | Jsr Corp | Thermoplastic elastomer composition for crosslinking foaming, method for manufacturing molded article, and molded article |
JP2006142843A (en) * | 2004-11-16 | 2006-06-08 | Bridgestone Corp | Pneumatic tire |
-
2013
- 2013-06-05 JP JP2013118553A patent/JP6181431B2/en active Active
Also Published As
Publication number | Publication date |
---|---|
JP2014234127A (en) | 2014-12-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5571921B2 (en) | Rubber composition for snow tire tread and pneumatic snow tire | |
JP6620089B2 (en) | Heavy duty pneumatic tire | |
JP4263232B2 (en) | Pneumatic tire with excellent high-speed durability | |
JP7006211B2 (en) | Pneumatic tires | |
JP6097750B2 (en) | tire | |
JP4405928B2 (en) | Rubber composition for base tread | |
JP3692027B2 (en) | Run flat tire | |
JP5845723B2 (en) | Pneumatic tire | |
JP2006062379A (en) | Pneumatic tire | |
JP6267517B2 (en) | Pneumatic tire | |
JP4012160B2 (en) | Rubber composition for base tread and pneumatic tire | |
JP6181431B2 (en) | Pneumatic tire | |
JP5442278B2 (en) | studless tire | |
JP4796454B2 (en) | Side reinforcing rubber composition and run-flat tire using the same | |
JP2009119994A (en) | Pneumatic tire | |
JP4843549B2 (en) | Rubber composition | |
JP6562061B2 (en) | Pneumatic tire | |
JP2018002934A (en) | Method for producing rubber composition, rubber composition and tire | |
JP2010144069A (en) | Rubber composition for tire and pneumatic tire using the same | |
JP6267444B2 (en) | Pneumatic tire | |
JP2005187825A (en) | Pneumatic tire | |
JP2005264150A (en) | Sidewall-reinforcing rubber composition and run flat tire using the same | |
JP5060686B2 (en) | Rubber composition for tire and pneumatic tire | |
JP7348491B2 (en) | Pneumatic tires for heavy loads | |
JP2011225697A (en) | Rubber composition and pneumatic tire using the same |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20160427 |
|
A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20161216 |
|
A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20170110 |
|
A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20170309 |
|
TRDD | Decision of grant or rejection written | ||
A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20170704 |
|
A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20170720 |
|
R150 | Certificate of patent or registration of utility model |
Ref document number: 6181431 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
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 |