WO2012164960A1 - Pneumatic tire and method for manufacturing same - Google Patents

Pneumatic tire and method for manufacturing same Download PDF

Info

Publication number
WO2012164960A1
WO2012164960A1 PCT/JP2012/003638 JP2012003638W WO2012164960A1 WO 2012164960 A1 WO2012164960 A1 WO 2012164960A1 JP 2012003638 W JP2012003638 W JP 2012003638W WO 2012164960 A1 WO2012164960 A1 WO 2012164960A1
Authority
WO
WIPO (PCT)
Prior art keywords
tire
pneumatic tire
short fibers
peripheral surface
inner peripheral
Prior art date
Application number
PCT/JP2012/003638
Other languages
French (fr)
Japanese (ja)
Inventor
渡辺　敏幸
Original Assignee
株式会社ブリヂストン
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社ブリヂストン filed Critical 株式会社ブリヂストン
Publication of WO2012164960A1 publication Critical patent/WO2012164960A1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D30/00—Producing pneumatic or solid tyres or parts thereof
    • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
    • B29D30/0681—Parts of pneumatic tyres; accessories, auxiliary operations
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C19/00—Tyre parts or constructions not otherwise provided for
    • B60C19/002—Noise damping elements provided in the tyre structure or attached thereto, e.g. in the tyre interior
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C5/00—Inflatable pneumatic tyres or inner tubes
    • B60C5/12—Inflatable pneumatic tyres or inner tubes without separate inflatable inserts, e.g. tubeless tyres with transverse section open to the rim
    • B60C5/14—Inflatable pneumatic tyres or inner tubes without separate inflatable inserts, e.g. tubeless tyres with transverse section open to the rim with impervious liner or coating on the inner wall of the tyre
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D30/00—Producing pneumatic or solid tyres or parts thereof
    • B29D30/06—Pneumatic tyres or parts thereof (e.g. produced by casting, moulding, compression moulding, injection moulding, centrifugal casting)
    • B29D30/0681—Parts of pneumatic tyres; accessories, auxiliary operations
    • B29D2030/0682—Inner liners

Definitions

  • the present invention relates to a pneumatic tire and a method for manufacturing the same, and more particularly to a pneumatic tire with reduced cavity resonance noise and a method for manufacturing the same.
  • One of the causes of noise generated by a pneumatic tire during travel is a cavity resonance caused by the length of the circular pipe inside the tire.
  • This cavity resonance sound is generated by resonance that occurs when the tread portion vibrates due to road surface irregularities when the tire rolls, and the vibration of the tread portion vibrates the air inside the tire.
  • the cavity resonance frequency is 200 to 270 Hz from the circumference of any passenger car tire, and when transmitted to the axle, it appears as a sharp peak different from the other bands. It contributes to room noise.
  • a method of absorbing sound inside the tire is effective.
  • a method of arranging a sound absorbing material such as urethane on the inner surface of the tire, or a patent document A method of adhering short fibers to the tire inner peripheral surface as described in 1 is proposed.
  • An object of the present invention is to provide a pneumatic tire that is easy to manufacture and can reliably reduce cavity resonance noise, and a method for manufacturing the same.
  • a pneumatic tire according to the present invention includes a tread portion, a pair of sidewall portions, a pair of bead portions, and at least one carcass ply extended in a toroid shape between bead cores embedded in each bead portion. And an inner liner including a resin layer disposed on the inner peripheral surface side of the tire, and short fibers are fixed to the tire inner peripheral surface side of the inner liner. It is characterized by.
  • the “inner peripheral surface of the tire” refers to the inner surface of the tire body that comes into contact with the air chamber when the tire body is mounted on the outer periphery of the rim, and other layers such as an inner liner are formed on the inner side in the tire radial direction. In the case where it is provided, the inner surface in the tire radial direction of the tire body in contact with the air chamber including these layers is used.
  • “Short fiber is fixed” means that a part of the short fiber is firmly fixed to the inner peripheral surface of the tire, and the other part is attached so as to be able to move freely.
  • the resin comprises a modified ethylene-vinyl alcohol copolymer obtained by reacting an ethylene-vinyl alcohol copolymer and an epoxy compound.
  • the short fibers are fixed with an adhesive.
  • the area of the region where the short fibers are fixed to the tire inner peripheral surface is 25% or more with respect to the surface area of the tire inner peripheral surface.
  • 100 or more are provided per square centimeter in the region where the short fibers are fixed to the tire inner peripheral surface.
  • the average length of the short fibers is in the range of 0.5 to 10 mm, and preferably the average diameter of the short fibers is in the range of 1 to 500 ⁇ m.
  • the region where the short fibers are fixed is composed of short fiber groups, and the plurality of short fiber groups are fixed independently of each other.
  • the short fibers are provided on the tire inner peripheral surface by electrostatic flocking.
  • the short fibers are fixed to the inner peripheral surface side of the inner liner so that these short fibers are attached to the inner peripheral surface of the air chamber formed when the tire is attached to the rim. Will be provided. Therefore, according to this pneumatic tire, it is possible to absorb the cavity resonance sound, and as a result, it is possible to reduce the noise caused by the cavity resonance phenomenon.
  • FIG. 1 is a cross-sectional view in the width direction illustrating one embodiment of a pneumatic tire according to the present invention with respect to a half portion of a tire in a tire posture before assembly to an applied rim.
  • (A) to (c) are diagrams each schematically showing an adhesive pattern of short fibers used in the present invention. It is a figure which shows typically the measurement of the axial force of the tire used in the Example. It is a figure which shows the measurement result in an Example.
  • 1 is a tread portion
  • 2 is a pair of side wall portions extending radially inward continuously to the respective side portions of the tread portion 1
  • 3 is continuously inward in the radial direction of the sidewall portion 2.
  • the illustrated pneumatic tire extends in a toroidal shape between a pair of bead portions 3 and bead cores 4 embedded in each bead portion 3, and is folded around each bead core 4 from the inner side to the outer side in the tire width direction.
  • a carcass 5 made of a single carcass ply is provided.
  • the carcass ply can be formed by a ply cord such as an organic fiber extending in a direction orthogonal to the tire circumferential direction.
  • a belt 6 consisting of three belt layers and a tread rubber 7 are arranged on the outer side in the radial direction of the carcass 5, and the surface of the tread rubber 7 is omitted in the figure.
  • a plurality of circumferential grooves and the like extending in the tire circumferential direction are formed.
  • the outer side surfaces of the carcass 5 in the tire width direction are covered with side rubbers 8 arranged along the outer side surfaces.
  • An inner liner 9 is disposed on the inner peripheral surface side of the tire, and the inner liner 9 can maintain the internal pressure in the tire so that air or the like does not leak.
  • innumerable short fibers 10 are fixed to the inner peripheral surface side of such an inner liner 9 substantially at right angles to the inner peripheral surface of the tire.
  • the inner liner 9 needs to contain the layer which consists of resin from a viewpoint of improving gas barrier property.
  • the resin include polyamide resins such as nylon 6, nylon 66, nylon 46, nylon 11, nylon 12, nylon 610, nylon 612, nylon 6/66, nylon 6/66/610, nylon MXD6; Polyester resins such as polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyetherimide (PEI), polyaryl ester (PAR), polybutylene naphthalate (PBN); polynitrile resin; polymethacrylate resin; ethylene -Polyvinyl resins such as vinyl acetate copolymer (EVA), polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride (PVDC), and polyvinyl chloride (PVC).
  • the ethylene - vinyl alcohol copolymer is preferred.
  • the ethylene - vinyl alcohol copolymer is preferred.
  • the resin is more preferably a modified ethylene-vinyl alcohol copolymer (C) obtained by reacting an ethylene-vinyl alcohol copolymer (A) with an epoxy compound (B).
  • the resin comprises a modified ethylene-vinyl alcohol copolymer obtained by reacting an ethylene-vinyl alcohol copolymer and an epoxy compound
  • the elastic modulus of the ethylene-vinyl alcohol copolymer can be greatly reduced.
  • the internal pressure retention can be greatly improved by improving the breakability at the time of bending and the degree of occurrence of cracks.
  • short fibers can be reliably bonded to the tire inner peripheral surface without applying a release agent to the tire inner peripheral surface in the vulcanization molding step as in a tire having a normal rubber inner liner. For this reason, it is not necessary to remove the mold release agent after the vulcanization molding, and the production becomes easy.
  • the ethylene-vinyl alcohol copolymer (A) preferably has an ethylene content of 25 to 50 mol%.
  • the lower limit of the ethylene content is more preferably 30 mol% or more, and further preferably 35 mol% or more.
  • the upper limit of the ethylene content is more preferably 48 mol% or less, and still more preferably 45 mol% or less.
  • the saponification degree of the ethylene-vinyl alcohol copolymer (A) is preferably 90% or more.
  • the saponification degree is more preferably 95% or more, further preferably 98% or more, and optimally 99% or more. If the degree of saponification is less than 90%, the gas barrier properties of the inner liner and the thermal stability during molding may be insufficient.
  • a suitable melt flow rate (MFR) (190 ° C., under a load of 2160 g) of the ethylene-vinyl alcohol copolymer (A) is 0.1 to 30 g / 10 minutes, and more preferably 0.3 to 25 g / 10 minutes.
  • MFR melt flow rate
  • the melting point of the ethylene-vinyl alcohol copolymer (A) is around 190 ° C or over 190 ° C, it is measured at multiple temperatures above the melting point under a load of 2160g.
  • the logarithm of MFR is plotted on the vertical axis and expressed as a value extrapolated to 190 ° C.
  • the epoxy compound (B) is not particularly limited, but is preferably a monovalent epoxy compound.
  • a crosslinking reaction with the ethylene-vinyl alcohol copolymer (A) occurs, and the quality of the inner liner may be deteriorated due to the generation of gels and blisters.
  • preferred monovalent epoxy compounds include glycidol and epoxypropane.
  • the modified ethylene-vinyl alcohol copolymer (C) is preferably obtained by reacting 1 to 50 parts by weight of the epoxy compound (B) with 100 parts by weight of the ethylene-vinyl alcohol copolymer (A). More preferably, the mixing ratio of (A) and (B) is (B) 2 to 40 parts by weight with respect to (A) 100 parts by weight, and more preferably (A) with respect to 100 parts by weight (B ) 5 to 35 parts by weight.
  • the method for producing the modified ethylene-vinyl alcohol copolymer (C) by reacting the ethylene-vinyl alcohol copolymer (A) with the epoxy compound (B) is not particularly limited, but the ethylene-vinyl alcohol copolymer ( A suitable method is a production method in which A) and the epoxy compound (B) are reacted in a solution.
  • the modified ethylene-vinyl alcohol copolymer (C) is obtained by reacting the epoxy compound (B) with the solution of the ethylene-vinyl alcohol copolymer (A) in the presence of an acid catalyst or an alkali catalyst.
  • the reaction solvent is preferably a polar aprotic solvent which is a good solvent for the ethylene-vinyl alcohol copolymer (A) such as dimethyl sulfoxide, dimethylformamide, dimethylacetamide and N-methylpyrrolidone.
  • Reaction catalysts include acid catalysts such as p-toluenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, sulfuric acid and boron trifluoride, and alkali catalysts such as sodium hydroxide, potassium hydroxide, lithium hydroxide and sodium methoxide Is mentioned. Of these, it is preferable to use an acid catalyst.
  • the amount of the catalyst is suitably about 0.0001 to 10 parts by weight with respect to 100 parts by weight of the ethylene-vinyl alcohol copolymer (A).
  • the modified ethylene-vinyl alcohol copolymer (C) can also be produced by dissolving the ethylene-vinyl alcohol copolymer (A) and the epoxy compound (B) in a reaction solvent and performing a heat treatment.
  • the melt flow rate (MFR) (under 190 ° C. and 2160 g load) of the modified ethylene-vinyl alcohol copolymer (C) is not particularly limited, but from the viewpoint of obtaining good gas barrier properties, flex resistance and fatigue resistance.
  • the melt flow rate (MFR) of the modified ethylene-vinyl alcohol copolymer (C) is preferably 0.1 to 30 g / 10 minutes, more preferably 0.3 to 25 g / 10 minutes, More preferably, it is 5 to 20 g / 10 min. However, when the melting point of the modified ethylene-vinyl alcohol copolymer (C) is around 190 ° C.
  • the modified ethylene-vinyl alcohol copolymer (C) is preferably crosslinked.
  • the layer made of the modified ethylene-vinyl alcohol copolymer (C) is significantly deformed and uniform in the vulcanization process for producing a pneumatic tire. The layer cannot be retained, and the gas barrier property, flex resistance, and fatigue resistance of the inner liner may be deteriorated.
  • the method for forming a crosslinked structure in the modified ethylene-vinyl alcohol copolymer (C) is not particularly limited, but a preferable method is a method of irradiating energy rays.
  • the energy rays include ionizing radiation such as ultraviolet rays, electron beams, X-rays, ⁇ rays, and ⁇ rays, and electron beams are preferable.
  • the dose of the electron beam is not particularly limited, but is preferably within a range of 10 to 60 Mrad.
  • the electron dose to irradiate is lower than 10 Mrad, it becomes difficult to crosslink.
  • the electron dose to be irradiated exceeds 60 Mrad, the molded body tends to deteriorate. More preferably, the electron dose range is 20-50 Mrad.
  • the inner liner 9 preferably has an oxygen permeation amount of 3.0 ⁇ 10 ⁇ 12 cm 3 ⁇ cm / cm 2 ⁇ sec ⁇ cmHg or less at 20 ° C. and 65 RH%, and 1.0 ⁇ 10 ⁇ 12 cm 3 ⁇ cm. / Cm 2 ⁇ sec ⁇ cmHg or lower, more preferably 5.0 ⁇ 10 ⁇ 13 cm 3 ⁇ cm / cm 2 ⁇ sec ⁇ cmHg or lower.
  • the modified ethylene-vinyl alcohol copolymer (C) is formed into a film, sheet or the like by melt molding for use as the inner liner 9 for a pneumatic tire.
  • extrusion molding etc. are mentioned as melt molding methods, such as a film and a sheet
  • the method of extrusion molding is not particularly limited, and examples thereof include a T-die method and an inflation method.
  • the melting temperature varies depending on the melting point of the copolymer and is preferably about 150 to 270 ° C.
  • the inner liner 9 is used for a pneumatic tire as a multilayer structure including at least one layer made of a modified ethylene-vinyl alcohol copolymer (C), in addition to being used for a pneumatic tire as a single-layer molded product. Can be done.
  • the inner liner may include an auxiliary layer 11 made of an elastomer adjacent to the layer made of the modified ethylene-vinyl alcohol copolymer (C).
  • the inner liner 9 has a layer made of the modified ethylene-vinyl alcohol copolymer (C) bonded to an auxiliary layer 11 made of an elastomer such as butyl rubber or a diene elastomer via at least one adhesive layer. Can be done.
  • the inner liner 9 having gas barrier properties is divided into two layers, a layer made of a modified ethylene-vinyl alcohol copolymer obtained by reacting an ethylene-vinyl alcohol copolymer and an epoxy compound, and a layer made of a resin containing a thermoplastic polyurethane.
  • a stacked structure in which more than one layer is stacked can also be used. With this structure, in addition to the gas barrier property by the inner liner 9, a multilayer structure having both high stretchability and thermoformability by a layer made of a resin containing thermoplastic polyurethane can be obtained.
  • the inner liner 9 including a layer made of resin can have various configurations. However, in order to greatly improve internal pressure retention, a layer made of resin on the innermost peripheral surface side of the inner liner 9. Are preferably arranged.
  • the inner liner 9 preferably has a layer thickness of 50 ⁇ m or less made of the modified ethylene-vinyl alcohol copolymer (C).
  • the merit of weight reduction becomes smaller than the inner liner using butyl rubber, halogenated butyl rubber or the like currently used.
  • the bending resistance and fatigue resistance of the layer made of the modified ethylene-vinyl alcohol copolymer (C) are lowered, and the bending deformation at the time of rolling of the tire is likely to cause breakage and cracking, and the crack is easy to extend. Therefore, the internal pressure retention after use of the tire may be lower than before use.
  • the thickness of the layer made of the modified ethylene-vinyl alcohol copolymer (C) is more preferably 1 to 40 ⁇ m, and further preferably 5 to 30 ⁇ m.
  • region where the short fiber 10 is being fixed to the tire internal peripheral surface of a short fiber is 25% or more with respect to the surface area of the internal peripheral surface of a tire.
  • the short fibers 10 can be provided with 100 or more per square centimeter in the region where the short fibers 10 are fixed to the tire inner peripheral surface, and this configuration is insufficient in reducing the cavity resonance. Therefore, the effect of reducing the cavity resonance can be sufficiently exhibited.
  • the short fiber 10 has an average length in the range of 0.5 to 10 mm, and with this configuration, the effect of reducing the cavity resonance is sufficiently exhibited without the effect of reducing the cavity resonance being insufficient. be able to.
  • the average length of the short fibers 10 is less than 0.5 mm, the cavity resonance noise may not be reduced.
  • the average length of the short fibers 10 exceeds 10 mm, the short fibers are easily entangled. As a result, workability deteriorates and uniform dispersion on the tire inner peripheral surface becomes difficult, and the sound absorption effect tends to be insufficient.
  • the short fibers 10 have an average diameter in the range of 1 to 500 ⁇ m. With this configuration, the effect of reducing cavity resonance can be sufficiently exhibited without the effect of reducing cavity resonance being insufficient.
  • the average diameter of the short fibers 10 is less than 1 ⁇ m, yarn breakage frequently occurs in the manufacturing process of the short fibers 10, and the productivity of the short fibers 10 may be reduced.
  • the weight tends to increase, which tends to affect the rotational balance of the tire.
  • the region to which the short fibers 10 are fixed is composed of short fiber groups, and a plurality of short fiber groups can be fixed independently of each other.
  • the region to which the short fibers 10 are fixed By disposing them in a continuous manner, even if the adhesive layer may be peeled off, the peeling range is very small and the effect of reducing cavity resonance can be maintained.
  • Such a short fiber 10 can be adhered to the inner peripheral surface of the tire by various methods, but it is preferable to use electrostatic flocking. Specifically, first, an adhesive is applied to the inner liner 9 and bonded to an auxiliary layer 11 made of an elastomer such as butyl rubber or a diene elastomer, thereby producing an inner liner made of the inner liner 9 and the auxiliary layer 11. Then, a tire is manufactured by a conventional method using this inner liner. Next, an adhesive is applied to the inner peripheral surface side of the tire, and innumerable short fibers subjected to the electrodeposition treatment are attached to the tire by static electricity on the portion where the adhesive is applied, and the adhesive is applied to the portion where the adhesive is applied. Only the short fiber 10 is bonded and fixed.
  • an adhesive is applied to the inner liner 9 and bonded to an auxiliary layer 11 made of an elastomer such as butyl rubber or a diene elastomer, thereby producing an inner liner made of the
  • a myriad of short fibers 10 can be easily fixed to the inner peripheral surface side of the inner liner, and a pneumatic tire capable of obtaining a sound absorbing effect can be efficiently manufactured.
  • electrostatic flocking is a processing technology that charges short fibers and implants the short fibers vertically onto an object that has been pre-applied with an electrostatic force.
  • Short fibers can be planted, which is suitable for planting short fibers on a tire inner circumferential surface having a three-dimensional curvature. Further, in the electrostatic flocking process, the short fibers 30 can be uniformly attached in the circumferential direction, so that the rotational balance is not deteriorated.
  • organic synthetic fibers organic synthetic fibers, inorganic fibers, regenerated fibers, natural fibers, and the like can be used.
  • organic synthetic fibers include polyolefins such as polyethylene, polypropylene and polybutylene, aliphatic polyamides such as nylon, aromatic polyamides such as Kevlar, polyethylene terephthalate, polyethylene naphthalate, polyethylene succinate, polyester, syndiotactic-1, Examples thereof include 2-polybutadiene, acrylonitrile-butadiene-styrene copolymer, polystyrene, and copolymers thereof.
  • the inorganic fiber include carbon fiber and glass fiber.
  • Examples of the recycled fiber include rayon and cupra.
  • natural fibers include cotton, silk, wool, and the like.
  • the short fibers 10 can be arranged in an adhesive pattern such as horizontal stripes, check and diagonal stripes, and preferably (a) horizontal stripes. If horizontal stripes are used, the area for bonding the short fibers can be widened, and the operation of applying the adhesive is simplified.
  • the product is precipitated in 100 parts by weight of distilled water, and N-methyl-2-pyrrolidone and unreacted glycidol are thoroughly washed with a large amount of distilled water to obtain a modified ethylene-vinyl alcohol copolymer (C).
  • the obtained modified ethylene-vinyl alcohol copolymer (C) was pulverized to a particle size of about 2 mm with a pulverizer, and then sufficiently washed with a large amount of distilled water again.
  • the washed particles were vacuum-dried at room temperature for 8 hours, and then melted at 200 ° C. using a twin-screw extruder to be pelletized.
  • a tire having a structure as shown in FIGS. 1 and 2 (a) and having a tire size of 195 / 65R15 was manufactured using the inner liner.
  • Nylon short fibers with a thickness of 15 denier (17 dtex) ( ⁇ 45 ⁇ ) and length of 2.5 mm were planted at about tens of thousands of fibers / cm 2 in an area of about 75% of the tire inner peripheral surface.
  • Example tires were prepared. The cavity resonance sound was evaluated for each of the example tire and the comparative example tire.
  • the comparative example tire does not require modification to the tire structure except that the short fiber is not provided, it was assumed to be similar to the example tire.
  • Example tires and comparative tires were each assembled on a 6JJ-15 rim, with a filling internal pressure of 220 kPa and a load mass of 4.25 kN.
  • Each tire is rolled at a speed of 80 km / h using a drum testing machine having a steel plate surface with a diameter of 1.7 m, and the vertical tire axial force is measured in a manner schematically shown in FIG. Measured and evaluated.
  • FIG. 4 shows the frequency spectrum of the in-vehicle noise predicted based on the result.
  • each of the example tire and the comparative example tire was assembled to a 6JJ-15 rim, and the internal pressure was set to 220 kPa, and the tire was mounted on a 2000 cc class passenger car. Then, in the case of using each tire, a passenger car on which two people got on traveled on an asphalt road rough at a vehicle speed at a speed of 50 km / h, and noise was measured at the driver's ear. Also in this example, it was possible to confirm the effect of reducing the cavity resonance sound equivalent to the result shown in FIG.

Abstract

A pneumatic tire is provided with: a tread section (1); a pair of sidewall sections (2); a pair of bead sections (3); a carcass (5) comprising a carcass ply toroidally extended between bead cores (4) respectively embedded in the bead sections (3); and an inner liner (9) disposed on the inner peripheral surface side of the tire and consisting of a resin. The pneumatic tire is characterized in that short fibers are secured to the inner peripheral surface side of the inner liner (9).

Description

空気入りタイヤおよびその製造方法Pneumatic tire and manufacturing method thereof
　本発明は、空気入りタイヤおよびその製造方法、特に、空洞共鳴音を低減させた空気入りタイヤおよびその製造方法に関するものである。 The present invention relates to a pneumatic tire and a method for manufacturing the same, and more particularly to a pneumatic tire with reduced cavity resonance noise and a method for manufacturing the same.
　空気入りタイヤが走行時に発生させる騒音の原因の一つに、タイヤ内部の円管長さに起因する空洞共鳴音がある。この空洞共鳴音は、タイヤが転動するときにトレッド部が路面の凹凸によって振動し、そのトレッド部の振動がタイヤ内部の空気を振動させるときに起こる共鳴によって生じるものである。
　そして空洞共鳴周波数は、いずれの乗用車用タイヤにおいても、その周長から２００～２７０Ｈｚとなり、車軸に伝達される際にはそれ以外の帯域と異なる鋭いピークとなって表れ、この共鳴は不快な車室内騒音の一因となっている。 One of the causes of noise generated by a pneumatic tire during travel is a cavity resonance caused by the length of the circular pipe inside the tire. This cavity resonance sound is generated by resonance that occurs when the tread portion vibrates due to road surface irregularities when the tire rolls, and the vibration of the tread portion vibrates the air inside the tire.
The cavity resonance frequency is 200 to 270 Hz from the circumference of any passenger car tire, and when transmitted to the axle, it appears as a sharp peak different from the other bands. It contributes to room noise.
　この空洞共鳴周波数は、発生要因がタイヤ内部の空気の共鳴であることから、タイヤ内部で吸音させる方法が有効であり、例えば、タイヤの内面にウレタン等の吸音材を配置する手法や、特許文献１に記載のようなタイヤ内周面に短繊維を接着する手法等が提案されている。 Since the cause of the cavity resonance frequency is the resonance of air inside the tire, a method of absorbing sound inside the tire is effective. For example, a method of arranging a sound absorbing material such as urethane on the inner surface of the tire, or a patent document A method of adhering short fibers to the tire inner peripheral surface as described in 1 is proposed.
　しかしながら、タイヤの内周面にはゴム製インナーライナーを具えることが一般的であり、その場合には加硫成型工程において内周面にシリコン等の離型材を塗布する必要がある。ここで、短繊維を固着させるには加硫成型後に離型剤を除去する必要があった。
　また、加硫成型前に短繊維を接着した場合には、接着後に離型材を塗布するため、短繊維等に離型材が付着して吸音効果が減少し、空洞共鳴音を十分に低減できないおそれがあった。 However, it is common to provide a rubber inner liner on the inner peripheral surface of the tire. In this case, it is necessary to apply a release material such as silicon to the inner peripheral surface in the vulcanization molding process. Here, in order to fix the short fibers, it was necessary to remove the release agent after the vulcanization molding.
In addition, when short fibers are bonded before vulcanization molding, a release material is applied after bonding, so that the release material adheres to the short fibers and the like and the sound absorption effect is reduced, and the cavity resonance noise may not be sufficiently reduced. was there.
特開２００４－８２３８７号公報JP 2004-82387 A
　本発明の目的は、特に、製造が容易で確実に空洞共鳴音の低減を図ることのできる空気入りタイヤおよびその製造方法を提供することである。 An object of the present invention is to provide a pneumatic tire that is easy to manufacture and can reliably reduce cavity resonance noise, and a method for manufacturing the same.
　本発明にかかる空気入りタイヤは、トレッド部と、一対のサイドウォール部と、一対のビード部と、各ビード部に埋設されたビードコア間にトロイド状に延在させた少なくとも一枚のカーカスプライからなるカーカスと、タイヤの内周面側に配設された、樹脂からなる層を含むインナーライナーとを具えてなるものであって、前記インナーライナーのタイヤ内周面側に短繊維を固着してなることを特徴とするものである。 A pneumatic tire according to the present invention includes a tread portion, a pair of sidewall portions, a pair of bead portions, and at least one carcass ply extended in a toroid shape between bead cores embedded in each bead portion. And an inner liner including a resin layer disposed on the inner peripheral surface side of the tire, and short fibers are fixed to the tire inner peripheral surface side of the inner liner. It is characterized by.
　ここで、「タイヤの内周面」とは、タイヤ本体をリムの外周に装着した際に空気室と接するタイヤ本体の内側表面をいい、そのタイヤ径方向内側にインナーライナーなどの他の層が設けられているような場合には、これらの層も含めて空気室と接するタイヤ本体のタイヤ径方向内側表面とする。
　「短繊維を固着」とは、短繊維の一部をタイヤの内周面にしっかりと固定し、それ以外の部分は自由に動くことができる状態で、立つように取り付けることとする。 Here, the “inner peripheral surface of the tire” refers to the inner surface of the tire body that comes into contact with the air chamber when the tire body is mounted on the outer periphery of the rim, and other layers such as an inner liner are formed on the inner side in the tire radial direction. In the case where it is provided, the inner surface in the tire radial direction of the tire body in contact with the air chamber including these layers is used.
“Short fiber is fixed” means that a part of the short fiber is firmly fixed to the inner peripheral surface of the tire, and the other part is attached so as to be able to move freely.
　このような空気入りタイヤにおいてより好ましくは、前記樹脂は、エチレン－ビニルアルコール共重合体とエポキシ化合物を反応させて得られる変性エチレン－ビニルアルコール共重合体からなる。
　好ましくは、前記短繊維を接着剤にて固着する。 In such a pneumatic tire, more preferably, the resin comprises a modified ethylene-vinyl alcohol copolymer obtained by reacting an ethylene-vinyl alcohol copolymer and an epoxy compound.
Preferably, the short fibers are fixed with an adhesive.
　また好ましくは、前記短繊維のタイヤ内周面に固着されている領域の面積は、タイヤの内周面の表面積に対して２５％以上である。好ましくは前記短繊維のタイヤ内周面に固着されている領域において、１平方センチメートル当たりに１００本以上設ける。さらに好ましくは短繊維の平均長さが０．５～１０ｍｍの範囲であり、好ましくは、短繊維の平均直径が１～５００μｍの範囲である。 Preferably, the area of the region where the short fibers are fixed to the tire inner peripheral surface is 25% or more with respect to the surface area of the tire inner peripheral surface. Preferably, 100 or more are provided per square centimeter in the region where the short fibers are fixed to the tire inner peripheral surface. More preferably, the average length of the short fibers is in the range of 0.5 to 10 mm, and preferably the average diameter of the short fibers is in the range of 1 to 500 μm.
　そしてまた好ましくは、前記短繊維の固着されている領域が、短繊維群からなり、複数の短繊維群が互いに独立して固着される。 Also preferably, the region where the short fibers are fixed is composed of short fiber groups, and the plurality of short fiber groups are fixed independently of each other.
　ところで、このような空気入りタイヤの製造方法としては、インナーライナーのタイヤ内周面側に接着剤を塗布する工程と、接着剤を塗布した部位に短繊維を接着させる工程とを有する。 By the way, as a manufacturing method of such a pneumatic tire, there are a step of applying an adhesive to the inner peripheral surface side of the inner liner and a step of adhering short fibers to a portion where the adhesive is applied.
　また好ましくは、前記短繊維を、静電植毛加工によりタイヤ内周面に設ける。 Preferably, the short fibers are provided on the tire inner peripheral surface by electrostatic flocking.
　本発明の空気入りタイヤでは、インナーライナーのタイヤ内周面側に短繊維を固着させることで、タイヤをリムに装着したときに形成される空気室の内周面に対してこれらの短繊維が設けられることになる。そのため、この空気入りタイヤによれば、空洞共鳴音を吸音して、その結果空洞共鳴現象に起因する騒音を低減することができる。 In the pneumatic tire of the present invention, the short fibers are fixed to the inner peripheral surface side of the inner liner so that these short fibers are attached to the inner peripheral surface of the air chamber formed when the tire is attached to the rim. Will be provided. Therefore, according to this pneumatic tire, it is possible to absorb the cavity resonance sound, and as a result, it is possible to reduce the noise caused by the cavity resonance phenomenon.
本発明の空気入りタイヤの一の実施形態を、適用リムへの組付け前のタイヤ姿勢で、タイヤの半部について示す幅方向断面図である。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view in the width direction illustrating one embodiment of a pneumatic tire according to the present invention with respect to a half portion of a tire in a tire posture before assembly to an applied rim. （ａ）～（ｃ）本発明で用いられる短繊維の接着パターンをそれぞれ模式的に示す図である。(A) to (c) are diagrams each schematically showing an adhesive pattern of short fibers used in the present invention. 実施例で用いたタイヤの軸力の測定を模式的に示す図である。It is a figure which shows typically the measurement of the axial force of the tire used in the Example. 実施例における測定結果を示す図である。It is a figure which shows the measurement result in an Example.
　以下に、図面を参照しながら本発明の空気入りタイヤを詳細に説明する。
　図中１はトレッド部を、２はトレッド部１のそれぞれの側部に連続して半径方向内方へ延びる一対のサイドウォール部を、そして３はサイドウォール部２の半径方向内方に連続するビード部をそれぞれ示す。 Hereinafter, the pneumatic tire of the present invention will be described in detail with reference to the drawings.
In the figure, 1 is a tread portion, 2 is a pair of side wall portions extending radially inward continuously to the respective side portions of the tread portion 1, and 3 is continuously inward in the radial direction of the sidewall portion 2. Each bead portion is shown.
　図示の空気入りタイヤは、一対のビード部３と、各ビード部３に埋設されたビードコア４間にトロイド状に延在し、各ビードコア４の周りにタイヤ幅方向の内側から外側に向けて折り返してなる、一枚のカーカスプライからなるカーカス５を具える。
　ここで、カーカスプライは、タイヤ周方向に直交する方向に延在する、例えば有機繊維等のプライコードによって形成することができる。 The illustrated pneumatic tire extends in a toroidal shape between a pair of bead portions 3 and bead cores 4 embedded in each bead portion 3, and is folded around each bead core 4 from the inner side to the outer side in the tire width direction. A carcass 5 made of a single carcass ply is provided.
Here, the carcass ply can be formed by a ply cord such as an organic fiber extending in a direction orthogonal to the tire circumferential direction.
　トレッド部１のカーカス５の半径方向外方には、図では三枚のベルト層からなるベルト６およびトレッドゴム７が配置され、このトレッドゴム７の表面には、図では省略されているが、タイヤ周方向に延びる複数本の周溝等が形成されている。 In the figure, a belt 6 consisting of three belt layers and a tread rubber 7 are arranged on the outer side in the radial direction of the carcass 5, and the surface of the tread rubber 7 is omitted in the figure. A plurality of circumferential grooves and the like extending in the tire circumferential direction are formed.
　サイドウォール部２およびビード部３では、カーカス５のタイヤ幅方向の外側面が、それらの外側面に沿わせて配置されたサイドゴム８によって覆われている。 In the sidewall portion 2 and the bead portion 3, the outer side surfaces of the carcass 5 in the tire width direction are covered with side rubbers 8 arranged along the outer side surfaces.
　タイヤの内周面側にはインナーライナー９を配置し、このインナーライナー９により、タイヤ内の内圧を保持して、空気等を漏れないようにすることができる。 An inner liner 9 is disposed on the inner peripheral surface side of the tire, and the inner liner 9 can maintain the internal pressure in the tire so that air or the like does not leak.
　そして、このようなインナーライナー９の内周面側には、タイヤの内周面に対して略直角に、無数の短繊維１０を固着させる。 And, innumerable short fibers 10 are fixed to the inner peripheral surface side of such an inner liner 9 substantially at right angles to the inner peripheral surface of the tire.
　ここで、インナーライナー９は、ガスバリア性を改善する観点から、樹脂からなる層を含むことを要する。
　ここで、樹脂としては、例えば、ナイロン６、ナイロン６６、ナイロン４６、ナイロン１１、ナイロン１２、ナイロン６１０、ナイロン６１２、ナイロン６／６６、ナイロン６／６６／６１０、ナイロンＭＸＤ６等のポリアミド系樹脂；ポリブチレンテレフタレート（ＰＢＴ）、ポリエチレンテレフタレート（ＰＥＴ）、ポリエーテルイミド（ＰＥＩ）、ポリアリールエステル（ＰＡＲ）、ポリブチレンナフタレート（ＰＢＮ）等のポリエステル系樹脂；ポリニトリル系樹脂；ポリメタクリレート系樹脂；エチレン－酢酸ビニル共重合体（ＥＶＡ）、ポリビニルアルコール（ＰＶＡ）、エチレン－ビニルアルコール共重合体（ＥＶＯＨ）、ポリ塩化ビニリデン（ＰＶＤＣ）、ポリ塩化ビニル（ＰＶＣ）等のポリビニル系樹脂が挙げられ、これらの中でも、柔軟性とガスバリア性の観点から、エチレン－ビニルアルコール共重合体が好ましい。なお、これら樹脂に用いることができる樹脂は、一種単独で用いてもよいし、二種以上を組み合わせて用いてもよい。 Here, the inner liner 9 needs to contain the layer which consists of resin from a viewpoint of improving gas barrier property.
Here, examples of the resin include polyamide resins such as nylon 6, nylon 66, nylon 46, nylon 11, nylon 12, nylon 610, nylon 612, nylon 6/66, nylon 6/66/610, nylon MXD6; Polyester resins such as polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyetherimide (PEI), polyaryl ester (PAR), polybutylene naphthalate (PBN); polynitrile resin; polymethacrylate resin; ethylene -Polyvinyl resins such as vinyl acetate copolymer (EVA), polyvinyl alcohol (PVA), ethylene-vinyl alcohol copolymer (EVOH), polyvinylidene chloride (PVDC), and polyvinyl chloride (PVC). Among the, from the viewpoint of flexibility and gas barrier properties, the ethylene - vinyl alcohol copolymer is preferred. In addition, the resin which can be used for these resins may be used individually by 1 type, and may be used in combination of 2 or more type.
　前記樹脂は、エチレン－ビニルアルコール共重合体（Ａ）とエポキシ化合物（Ｂ）を反応させて得られる変性エチレン－ビニルアルコール共重合体（Ｃ）であることがさらに好ましい。 The resin is more preferably a modified ethylene-vinyl alcohol copolymer (C) obtained by reacting an ethylene-vinyl alcohol copolymer (A) with an epoxy compound (B).
　前記樹脂が、エチレン－ビニルアルコール共重合体とエポキシ化合物を反応させて得られる変性エチレン－ビニルアルコール共重合体からなることで、エチレン－ビニルアルコール共重合体の弾性率を大幅に下げることができ、屈曲時の破断性、クラックの発生度合いを改良して、内圧保持性を大幅に向上させることができる。
　また、通常のゴム製インナーライナーを有するタイヤのように加硫成型工程でタイヤ内周面に離型材を塗布することなく、タイヤ内周面に短繊維を確実に接着させることができる。このため、加硫成型後に離型剤を除去する必要がなく、製造が容易となる。 Since the resin comprises a modified ethylene-vinyl alcohol copolymer obtained by reacting an ethylene-vinyl alcohol copolymer and an epoxy compound, the elastic modulus of the ethylene-vinyl alcohol copolymer can be greatly reduced. The internal pressure retention can be greatly improved by improving the breakability at the time of bending and the degree of occurrence of cracks.
Further, short fibers can be reliably bonded to the tire inner peripheral surface without applying a release agent to the tire inner peripheral surface in the vulcanization molding step as in a tire having a normal rubber inner liner. For this reason, it is not necessary to remove the mold release agent after the vulcanization molding, and the production becomes easy.
　ここで、エチレン－ビニルアルコール共重合体（Ａ）としては、好ましくはエチレン含有量は２５～５０モル％である。良好な耐屈曲性及び耐疲労性を得る観点からは、エチレン含有量の下限はより好ましくは３０モル％以上であり、さらに好ましくは３５モル％以上である。また、ガスバリア性の観点からは、エチレン含有量の上限はより好ましくは４８モル％以下であり、さらに好ましくは４５モル％以下である。
　エチレン含有量が２５モル％未満の場合は耐屈曲性及び耐疲労性が悪化したり、溶融成形性が悪化したりするおそれがある。一方、５０モル％を超えるとガスバリア性が不足する傾向がある。 Here, the ethylene-vinyl alcohol copolymer (A) preferably has an ethylene content of 25 to 50 mol%. From the viewpoint of obtaining good bending resistance and fatigue resistance, the lower limit of the ethylene content is more preferably 30 mol% or more, and further preferably 35 mol% or more. From the viewpoint of gas barrier properties, the upper limit of the ethylene content is more preferably 48 mol% or less, and still more preferably 45 mol% or less.
When the ethylene content is less than 25 mol%, the bending resistance and fatigue resistance may be deteriorated, or the melt moldability may be deteriorated. On the other hand, when it exceeds 50 mol%, gas barrier properties tend to be insufficient.
　上記エチレン－ビニルアルコール共重合体（Ａ）のケン化度は、好ましくは９０％以上である。ケン化度は、より好ましくは９５％以上であり、さらに好ましくは９８％以上であり、最適には９９％以上である。
　ケン化度が９０％未満では、インナーライナーのガスバリア性および成形時の熱安定性が不十分となるおそれがある。 The saponification degree of the ethylene-vinyl alcohol copolymer (A) is preferably 90% or more. The saponification degree is more preferably 95% or more, further preferably 98% or more, and optimally 99% or more.
If the degree of saponification is less than 90%, the gas barrier properties of the inner liner and the thermal stability during molding may be insufficient.
　上記エチレン－ビニルアルコール共重合体（Ａ）の好適なメルトフローレート（ＭＦＲ）（１９０℃、２１６０ｇ荷重下）は０．１～３０ｇ／１０分であり、より好適には０．３～２５ｇ／１０分である。但し、エチレン－ビニルアルコール共重合体（Ａ）の融点が１９０℃付近あるいは１９０℃を超えるものは２１６０ｇ荷重下、融点以上の複数の温度で測定し、片対数グラフで絶対温度の逆数を横軸、ＭＦＲの対数を縦軸にプロットし、１９０℃に外挿した値で表す。 A suitable melt flow rate (MFR) (190 ° C., under a load of 2160 g) of the ethylene-vinyl alcohol copolymer (A) is 0.1 to 30 g / 10 minutes, and more preferably 0.3 to 25 g / 10 minutes. However, when the melting point of the ethylene-vinyl alcohol copolymer (A) is around 190 ° C or over 190 ° C, it is measured at multiple temperatures above the melting point under a load of 2160g. The logarithm of MFR is plotted on the vertical axis and expressed as a value extrapolated to 190 ° C.
　また、エポキシ化合物（Ｂ）は特に制限はされないが、一価エポキシ化合物であることが好ましい。二価以上のエポキシ化合物である場合、エチレン－ビニルアルコール共重合体（Ａ）との架橋反応が生じ、ゲル、ブツ等の発生によりインナーライナーの品質が低下するおそれがある。変性エチレン－ビニルアルコール共重合体（Ｃ）の製造の容易性、ガスバリア性、耐屈曲性および耐疲労性の観点から、好ましい一価エポキシ化合物としてグリシドール及びエポキシプロパンが挙げられる。 The epoxy compound (B) is not particularly limited, but is preferably a monovalent epoxy compound. In the case of an epoxy compound having a valence of 2 or more, a crosslinking reaction with the ethylene-vinyl alcohol copolymer (A) occurs, and the quality of the inner liner may be deteriorated due to the generation of gels and blisters. From the viewpoint of ease of production of the modified ethylene-vinyl alcohol copolymer (C), gas barrier properties, flex resistance, and fatigue resistance, preferred monovalent epoxy compounds include glycidol and epoxypropane.
　変性エチレン－ビニルアルコール共重合体（Ｃ）は、好ましくはエチレン－ビニルアルコール共重合体（Ａ）１００重量部に対して、エポキシ化合物（Ｂ）１～５０重量部を反応させて得られる。より好ましくは、（Ａ）および（Ｂ）の混合比は、（Ａ）１００重量部に対して（Ｂ）２～４０重量部であり、さらに好ましくは（Ａ）１００重量部に対して（Ｂ）５～３５重量部である。 The modified ethylene-vinyl alcohol copolymer (C) is preferably obtained by reacting 1 to 50 parts by weight of the epoxy compound (B) with 100 parts by weight of the ethylene-vinyl alcohol copolymer (A). More preferably, the mixing ratio of (A) and (B) is (B) 2 to 40 parts by weight with respect to (A) 100 parts by weight, and more preferably (A) with respect to 100 parts by weight (B ) 5 to 35 parts by weight.
　エチレン－ビニルアルコール共重合体（Ａ）とエポキシ化合物（Ｂ）とを反応させて変性エチレン－ビニルアルコール共重合体（Ｃ）を製造する方法は特に限定されないが、エチレン－ビニルアルコール共重合体（Ａ）とエポキシ化合物（Ｂ）とを溶液中で反応させる製造法が好適な方法として挙げられる。 The method for producing the modified ethylene-vinyl alcohol copolymer (C) by reacting the ethylene-vinyl alcohol copolymer (A) with the epoxy compound (B) is not particularly limited, but the ethylene-vinyl alcohol copolymer ( A suitable method is a production method in which A) and the epoxy compound (B) are reacted in a solution.
　溶液反応による製造法では、エチレン－ビニルアルコール共重合体（Ａ）の溶液に酸触媒あるいはアルカリ触媒存在下でエポキシ化合物（Ｂ）を反応させることによって変性エチレン－ビニルアルコール共重合体（Ｃ）が得られる。反応溶媒としては、ジメチルスルホキシド、ジメチルホルムアミド、ジメチルアセトアミドおよびＮ－メチルピロリドン等のエチレン－ビニルアルコール共重合体（Ａ）の良溶媒である極性非プロトン性溶媒が好ましい。反応触媒としては、ｐ－トルエンスルホン酸、メタンスルホン酸、トリフルオロメタンスルホン酸、硫酸および三フッ化ホウ素等の酸触媒や水酸化ナトリウム、水酸化カリウム、水酸化リチウム、ナトリウムメトキシド等のアルカリ触媒が挙げられる。これらの内、酸触媒を用いることが好ましい。触媒量としては、エチレン－ビニルアルコール共重合体（Ａ）１００重量部に対し、０．０００１～１０重量部程度が適当である。また、エチレン－ビニルアルコール共重合体（Ａ）およびエポキシ化合物（Ｂ）を反応溶媒に溶解させ、加熱処理を行うことによっても変性エチレン－ビニルアルコール共重合体（Ｃ）を製造することができる。 In the production method by solution reaction, the modified ethylene-vinyl alcohol copolymer (C) is obtained by reacting the epoxy compound (B) with the solution of the ethylene-vinyl alcohol copolymer (A) in the presence of an acid catalyst or an alkali catalyst. can get. The reaction solvent is preferably a polar aprotic solvent which is a good solvent for the ethylene-vinyl alcohol copolymer (A) such as dimethyl sulfoxide, dimethylformamide, dimethylacetamide and N-methylpyrrolidone. Reaction catalysts include acid catalysts such as p-toluenesulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, sulfuric acid and boron trifluoride, and alkali catalysts such as sodium hydroxide, potassium hydroxide, lithium hydroxide and sodium methoxide Is mentioned. Of these, it is preferable to use an acid catalyst. The amount of the catalyst is suitably about 0.0001 to 10 parts by weight with respect to 100 parts by weight of the ethylene-vinyl alcohol copolymer (A). The modified ethylene-vinyl alcohol copolymer (C) can also be produced by dissolving the ethylene-vinyl alcohol copolymer (A) and the epoxy compound (B) in a reaction solvent and performing a heat treatment.
　上記変性エチレン－ビニルアルコール共重合体（Ｃ）のメルトフローレート（ＭＦＲ）（１９０℃、２１６０ｇ荷重下）は特に制限はされないが、良好なガスバリア性、耐屈曲性および耐疲労を得る観点からは、変性エチレン－ビニルアルコール共重合体（Ｃ）のメルトフローレート（ＭＦＲ）が０．１～３０ｇ／１０分であることが好ましく、０．３～２５ｇ／１０分であることがより好ましく、０．５～２０ｇ／１０分であることがさらに好ましい。但し、変性エチレン－ビニルアルコール共重合体（Ｃ）の融点が１９０℃付近あるいは１９０℃を超えるものは２１６０ｇ荷重下、融点以上の複数の温度で測定し、片対数グラフで絶対温度の逆数を横軸、ＭＦＲの対数を縦軸にプロットし、１９０℃に外挿した値で表す。 The melt flow rate (MFR) (under 190 ° C. and 2160 g load) of the modified ethylene-vinyl alcohol copolymer (C) is not particularly limited, but from the viewpoint of obtaining good gas barrier properties, flex resistance and fatigue resistance. The melt flow rate (MFR) of the modified ethylene-vinyl alcohol copolymer (C) is preferably 0.1 to 30 g / 10 minutes, more preferably 0.3 to 25 g / 10 minutes, More preferably, it is 5 to 20 g / 10 min. However, when the melting point of the modified ethylene-vinyl alcohol copolymer (C) is around 190 ° C. or exceeds 190 ° C., it is measured at a plurality of temperatures above the melting point under a load of 2160 g. The logarithm of the axis and MFR is plotted on the vertical axis and expressed as a value extrapolated to 190 ° C.
　上記変性エチレン－ビニルアルコール共重合体（Ｃ）が架橋されていることが好ましい。変性エチレン－ビニルアルコール共重合体（Ｃ）が架橋されていない場合、空気入りタイヤを製造する加硫工程において変性エチレン－ビニルアルコール共重合体（Ｃ）からなる層が著しく変形してしまい均一な層を保持できなくなり、インナーライナーのガスバリア性、耐屈曲性、耐疲労性を悪化するおそれが生じる。 The modified ethylene-vinyl alcohol copolymer (C) is preferably crosslinked. When the modified ethylene-vinyl alcohol copolymer (C) is not cross-linked, the layer made of the modified ethylene-vinyl alcohol copolymer (C) is significantly deformed and uniform in the vulcanization process for producing a pneumatic tire. The layer cannot be retained, and the gas barrier property, flex resistance, and fatigue resistance of the inner liner may be deteriorated.
　上記変性エチレン－ビニルアルコール共重合体（Ｃ）に架橋構造を形成させる方法に関しては特に限定されないが、好ましい方法としてエネルギー線を照射する方法が挙げられる。エネルギー線としては、紫外線、電子線、Ｘ線、α線、γ線等の電離放射線が挙げられ、好ましくは電子線が挙げられる。 The method for forming a crosslinked structure in the modified ethylene-vinyl alcohol copolymer (C) is not particularly limited, but a preferable method is a method of irradiating energy rays. Examples of the energy rays include ionizing radiation such as ultraviolet rays, electron beams, X-rays, α rays, and γ rays, and electron beams are preferable.
　電子線の照射方法に関しては、押出成形によるフィルム、シート加工の後、電子線照射装置に成形体を導入し、電子線を照射する方法が挙げられる。電子線の線量に関しては特に限定されないが、好ましくは１０～６０Ｍｒａｄの範囲内である。照射する電子線量が１０Ｍｒａｄより低いと、架橋が進み難くなる。一方、照射する電子線量が６０Ｍｒａｄを越えると成形体の劣化が進行しやすくなる。より好適には電子線量の範囲は２０～５０Ｍｒａｄである。 Regarding the electron beam irradiation method, a method of irradiating an electron beam by introducing a molded body into an electron beam irradiation apparatus after processing a film or sheet by extrusion molding. The dose of the electron beam is not particularly limited, but is preferably within a range of 10 to 60 Mrad. When the electron dose to irradiate is lower than 10 Mrad, it becomes difficult to crosslink. On the other hand, when the electron dose to be irradiated exceeds 60 Mrad, the molded body tends to deteriorate. More preferably, the electron dose range is 20-50 Mrad.
　インナーライナー９は２０℃、６５ＲＨ％における酸素透過量が３．０×１０－１２ｃｍ３・ｃｍ／ｃｍ２・ｓｅｃ・ｃｍＨｇ以下であることが好ましく、１．０×１０－１２ｃｍ３・ｃｍ／ｃｍ２・ｓｅｃ・ｃｍＨｇ以下であることがより好ましく、５．０×１０－１３ｃｍ３・ｃｍ／ｃｍ２・ｓｅｃ・ｃｍＨｇ以下であることがさらに好ましい。 The inner liner 9 preferably has an oxygen permeation amount of 3.0 × 10 −12 cm 3 · cm / cm 2 · sec · cmHg or less at 20 ° C. and 65 RH%, and 1.0 × 10 −12 cm 3 · cm. / Cm 2 · sec · cmHg or lower, more preferably 5.0 × 10 −13 cm 3 · cm / cm 2 · sec · cmHg or lower.
　変性エチレン－ビニルアルコール共重合体（Ｃ）は、空気入りタイヤ用インナーライナー９として用いるために溶融成形によりフィルム、シート等に成形される。また、フィルム、シート等の溶融成形法としては押出成形等が挙げられる。押出成形の方法は特に限定されず、Ｔダイ法、インフレーション法が挙げられる。溶融温度は該共重合体の融点等により異なるが１５０～２７０℃程度が好ましい。 The modified ethylene-vinyl alcohol copolymer (C) is formed into a film, sheet or the like by melt molding for use as the inner liner 9 for a pneumatic tire. Moreover, extrusion molding etc. are mentioned as melt molding methods, such as a film and a sheet | seat. The method of extrusion molding is not particularly limited, and examples thereof include a T-die method and an inflation method. The melting temperature varies depending on the melting point of the copolymer and is preferably about 150 to 270 ° C.
　インナーライナー９は、単層の成形物として空気入りタイヤに供せられる以外に、変性エチレン－ビニルアルコール共重合体（Ｃ）からなる層を少なくとも１層含む多層構造体として空気入りタイヤに供せられることができる。また、本発明ではインナーライナーが、変性エチレン－ビニルアルコール共重合体（Ｃ）からなる層に隣接して、エラストマーからなる補助層１１を具えることができる。 The inner liner 9 is used for a pneumatic tire as a multilayer structure including at least one layer made of a modified ethylene-vinyl alcohol copolymer (C), in addition to being used for a pneumatic tire as a single-layer molded product. Can be done. In the present invention, the inner liner may include an auxiliary layer 11 made of an elastomer adjacent to the layer made of the modified ethylene-vinyl alcohol copolymer (C).
　また、インナーライナー９は、変性エチレン－ビニルアルコール共重合体（Ｃ）からなる層が、少なくとも１層以上の接着剤層を介してブチルゴム、ジエン系エラストマー等のエラストマーからなる補助層１１に貼り合わせられることができる。 The inner liner 9 has a layer made of the modified ethylene-vinyl alcohol copolymer (C) bonded to an auxiliary layer 11 made of an elastomer such as butyl rubber or a diene elastomer via at least one adhesive layer. Can be done.
　また、ガスバリア性を有するインナーライナー９を、エチレン－ビニルアルコール共重合体とエポキシ化合物を反応させて得られる変性エチレン－ビニルアルコール共重合体からなる層と熱可塑性ポリウレタンを含む樹脂からなる層を二層以上に重ね合わせた積層構造とすることもできる。
　この構造により、インナーライナー９によるガスバリア性に加え、熱可塑性ポリウレタンを含む樹脂からなる層による高い延伸性及び熱成形性を併せ持つ多層構造とすることができる。 Further, the inner liner 9 having gas barrier properties is divided into two layers, a layer made of a modified ethylene-vinyl alcohol copolymer obtained by reacting an ethylene-vinyl alcohol copolymer and an epoxy compound, and a layer made of a resin containing a thermoplastic polyurethane. A stacked structure in which more than one layer is stacked can also be used.
With this structure, in addition to the gas barrier property by the inner liner 9, a multilayer structure having both high stretchability and thermoformability by a layer made of a resin containing thermoplastic polyurethane can be obtained.
　エチレン－ビニルアルコール共重合体は－ＯＨ基を有するため、比較的ゴムとの接着を確保するのが容易である。例えば、塩化ゴム・イソシアネート系の接着剤を接着層に用いれば、タイヤに使用されているゴム組成物との接着が確保できる。
　以上のように樹脂からなる層を含むインナーライナー９は様々な構成とすることができるが、内圧保持性を大幅な向上等させるために、インナーライナー９の最内周面側に樹脂からなる層が配置するのが好ましい。 Since the ethylene-vinyl alcohol copolymer has an —OH group, it is relatively easy to ensure adhesion with rubber. For example, if a chlorinated rubber / isocyanate adhesive is used for the adhesive layer, adhesion to the rubber composition used in the tire can be ensured.
As described above, the inner liner 9 including a layer made of resin can have various configurations. However, in order to greatly improve internal pressure retention, a layer made of resin on the innermost peripheral surface side of the inner liner 9. Are preferably arranged.
　インナーライナー９は、変性エチレン－ビニルアルコール共重合体（Ｃ）からなる層の厚さが５０μｍ以下であるのが好ましい。５０μｍを越える場合、現在用いられているブチルゴム、ハロゲン化ブチルゴムなどを使用したインナーライナーに対して重量低減のメリットが小さくなる。さらに、変性エチレン－ビニルアルコール共重合体（Ｃ）からなる層の耐屈曲性、耐疲労性が低下し、タイヤ転動時の屈曲変形により破断・亀裂が生じやすく、また、亀裂が伸展しやすくなるため、タイヤ使用後の内圧保持性が使用前と比べて低下することがあった。一方、インナーライナーのガスバリア性の観点から０．１μｍ以上であることが好ましい。ガスバリア性、耐屈曲性、および耐疲労性の観点から変性エチレン－ビニルアルコール共重合体（Ｃ）からなる層の厚さは１～４０μｍがより好ましく、５～３０μｍが更に好ましい。 The inner liner 9 preferably has a layer thickness of 50 μm or less made of the modified ethylene-vinyl alcohol copolymer (C). When it exceeds 50 μm, the merit of weight reduction becomes smaller than the inner liner using butyl rubber, halogenated butyl rubber or the like currently used. Further, the bending resistance and fatigue resistance of the layer made of the modified ethylene-vinyl alcohol copolymer (C) are lowered, and the bending deformation at the time of rolling of the tire is likely to cause breakage and cracking, and the crack is easy to extend. Therefore, the internal pressure retention after use of the tire may be lower than before use. On the other hand, it is preferable that it is 0.1 micrometer or more from a viewpoint of the gas barrier property of an inner liner. From the viewpoint of gas barrier properties, flex resistance, and fatigue resistance, the thickness of the layer made of the modified ethylene-vinyl alcohol copolymer (C) is more preferably 1 to 40 μm, and further preferably 5 to 30 μm.
　ところで、短繊維１０は、短繊維のタイヤ内周面に固着されている領域の面積は、タイヤの内周面の表面積に対して２５％以上であることが好ましい。
　この構成により、空洞共鳴の低減効果を十分に発揮することができる。
　一般的な乗用車用のタイヤの場合では、吸音効果を得るための短繊維の重量は数１０ｇ程度で十分であり、タイヤ重量への影響は殆ど無視できる。また、使用量が少ないので、短繊維の付着に多少のむらがあっても回転バランスへの影響は無視することができる。 By the way, it is preferable that the area of the area | region where the short fiber 10 is being fixed to the tire internal peripheral surface of a short fiber is 25% or more with respect to the surface area of the internal peripheral surface of a tire.
With this configuration, the effect of reducing cavity resonance can be sufficiently exhibited.
In the case of a general tire for a passenger car, the weight of the short fiber for obtaining the sound absorption effect is sufficient to be about several tens of grams, and the influence on the tire weight can be almost ignored. In addition, since the amount used is small, the influence on the rotation balance can be ignored even if there is some unevenness in the adhesion of the short fibers.
　また好ましくは、短繊維１０は、短繊維１０がタイヤ内周面に固着されている領域において、１平方センチメートル当たりに１００本以上設けることができ、この構成により、空洞共鳴の低減効果が不足することなく、空洞共鳴音の低減効果を十分に発揮することができる。 Preferably, the short fibers 10 can be provided with 100 or more per square centimeter in the region where the short fibers 10 are fixed to the tire inner peripheral surface, and this configuration is insufficient in reducing the cavity resonance. Therefore, the effect of reducing the cavity resonance can be sufficiently exhibited.
　そしてまた好ましくは、短繊維１０は、平均長さが０．５～１０ｍｍの範囲であり、この構成により、空洞共鳴の低減効果が不足することなく、空洞共鳴音の低減効果を十分に発揮することができる。 Preferably, the short fiber 10 has an average length in the range of 0.5 to 10 mm, and with this configuration, the effect of reducing the cavity resonance is sufficiently exhibited without the effect of reducing the cavity resonance being insufficient. be able to.
　すなわち、短繊維１０の平均長さが０．５ｍｍ未満では、空洞共鳴音を低減することができなくなるおそれがある一方、短繊維１０の平均長さが１０ｍｍを超えると、短繊維同士が絡み易くなって作業性が悪化すると共に、タイヤ内周面への均一な分散が困難となり、吸音効果が十分に発現できなくなる傾向がある。 That is, if the average length of the short fibers 10 is less than 0.5 mm, the cavity resonance noise may not be reduced. On the other hand, if the average length of the short fibers 10 exceeds 10 mm, the short fibers are easily entangled. As a result, workability deteriorates and uniform dispersion on the tire inner peripheral surface becomes difficult, and the sound absorption effect tends to be insufficient.
　好ましくは、短繊維１０は、平均直径が１～５００μｍの範囲であり、この構成により、空洞共鳴の低減効果が不足することなく、空洞共鳴音の低減効果を十分に発揮することができる。 Preferably, the short fibers 10 have an average diameter in the range of 1 to 500 μm. With this configuration, the effect of reducing cavity resonance can be sufficiently exhibited without the effect of reducing cavity resonance being insufficient.
　すなわち、短繊維１０の平均直径が１μｍ未満では、短繊維１０の製造工程において糸切れが多発し、短繊維１０の生産性が低下するおそれがある一方、５００μｍを超えると、短繊維１０の総重量が大きくなり、タイヤの回転バランスに与える影響する傾向がある。 That is, when the average diameter of the short fibers 10 is less than 1 μm, yarn breakage frequently occurs in the manufacturing process of the short fibers 10, and the productivity of the short fibers 10 may be reduced. The weight tends to increase, which tends to affect the rotational balance of the tire.
　また好ましくは、短繊維１０の固着されている領域を、短繊維群からなり、複数の短繊維群が互いに独立して固着させることができ、この構成により、短繊維１０の固着されている領域を、連続せずに設けることにより、仮に接着層がはがれることがあったとしても、はがれる範囲が極わずかでとどまり、空洞共鳴を低減する効果を維持することができる。 Preferably, the region to which the short fibers 10 are fixed is composed of short fiber groups, and a plurality of short fiber groups can be fixed independently of each other. With this configuration, the region to which the short fibers 10 are fixed By disposing them in a continuous manner, even if the adhesive layer may be peeled off, the peeling range is very small and the effect of reducing cavity resonance can be maintained.
　このような短繊維１０は、種々の方法でタイヤの内周面に接着させることができるが、静電植毛加工を用いることが好ましい。具体的には、まず、インナーライナー９に、接着剤を塗布し、ブチルゴム、ジエン系エラストマー等のエラストマーからなる補助層１１と貼り合わせることにより、インナーライナー９および補助層１１からなるインナーライナーを作製し、このインナーライナーを用い常法によりタイヤを製作する。次いでこのタイヤの内周面側に接着剤を塗布して、この接着剤を塗布した部位に電着処理の行われた無数の短繊維が静電気によりタイヤに付着され、接着剤を塗布した部分にのみ短繊維１０が接着固定される。 Such a short fiber 10 can be adhered to the inner peripheral surface of the tire by various methods, but it is preferable to use electrostatic flocking. Specifically, first, an adhesive is applied to the inner liner 9 and bonded to an auxiliary layer 11 made of an elastomer such as butyl rubber or a diene elastomer, thereby producing an inner liner made of the inner liner 9 and the auxiliary layer 11. Then, a tire is manufactured by a conventional method using this inner liner. Next, an adhesive is applied to the inner peripheral surface side of the tire, and innumerable short fibers subjected to the electrodeposition treatment are attached to the tire by static electricity on the portion where the adhesive is applied, and the adhesive is applied to the portion where the adhesive is applied. Only the short fiber 10 is bonded and fixed.
　上述の方法により、無数の短繊維１０を簡単にインナーライナーの内周面側に固着させることができ、吸音効果を得ることのできる空気入りタイヤを効率的に製造することができる。 By the above-described method, a myriad of short fibers 10 can be easily fixed to the inner peripheral surface side of the inner liner, and a pneumatic tire capable of obtaining a sound absorbing effect can be efficiently manufactured.
　ここで、静電植毛加工は、短繊維を帯電させ、静電気力により、予め接着剤を塗布した物体に短繊維を垂直に植毛する加工技術であるため、複雑な形状の物体表面にも均一に短繊維を植毛することができ、３次元的に曲率をもったタイヤ内周面に短繊維を植毛するのに適している。
　また、静電植毛加工では、短繊維３０を周方向へ均一に付着させることができるので、回転バランスを悪化させることが無い。 Here, electrostatic flocking is a processing technology that charges short fibers and implants the short fibers vertically onto an object that has been pre-applied with an electrostatic force. Short fibers can be planted, which is suitable for planting short fibers on a tire inner circumferential surface having a three-dimensional curvature.
Further, in the electrostatic flocking process, the short fibers 30 can be uniformly attached in the circumferential direction, so that the rotational balance is not deteriorated.
　このような短繊維１０としては、有機合成繊維、無機繊維、再生繊維、天然繊維等を用いることができる。 As such short fibers 10, organic synthetic fibers, inorganic fibers, regenerated fibers, natural fibers, and the like can be used.
　有機合成繊維としては、例えば、ポリエチレン、ポリプロピレン、ポリブチレン等のポリオレフィン、ナイロン等の脂肪族ポリアミド、ケブラー等の芳香族ポリアミド、ポリエチレンテレフタレート、ポリエチレンナフタレート、ポリエチレンサクシネート、ポリエステル、シンジオタクチック－１，２－ポリブタジエン、アクリロニトリル－ブタジエン－スチレン共重合体、ポリスチレン、及びこれらの共重合体等が上げられる。
　無機繊維としては、例えば、カーボン繊維、グラスファイバー等が挙げられる。
　再生繊維としては、例えば、レーヨン、キュプラ等が挙げられる。
　天然繊維としては、例えば、綿、絹、羊毛等が挙げられる。 Examples of organic synthetic fibers include polyolefins such as polyethylene, polypropylene and polybutylene, aliphatic polyamides such as nylon, aromatic polyamides such as Kevlar, polyethylene terephthalate, polyethylene naphthalate, polyethylene succinate, polyester, syndiotactic-1, Examples thereof include 2-polybutadiene, acrylonitrile-butadiene-styrene copolymer, polystyrene, and copolymers thereof.
Examples of the inorganic fiber include carbon fiber and glass fiber.
Examples of the recycled fiber include rayon and cupra.
Examples of natural fibers include cotton, silk, wool, and the like.
　短繊維１０は、図２（ａ）～（ｃ）に模式的に示すように、横縞、チェックおよび斜め縞のような接着パターンで配置することができ、好ましくは（ａ）横縞である。横縞とすれば、短繊維を接着する面積を広くとれ、接着剤を塗布する作業が簡単となる。 As schematically shown in FIGS. 2 (a) to 2 (c), the short fibers 10 can be arranged in an adhesive pattern such as horizontal stripes, check and diagonal stripes, and preferably (a) horizontal stripes. If horizontal stripes are used, the area for bonding the short fibers can be widened, and the operation of applying the adhesive is simplified.
　以下、実施例にて本発明をさらに詳しく説明するが、これらの実施例によって本発明は何ら限定されるものではない。 Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
＜変性エチレン－ビニルアルコール共重合体（Ｃ）の合成＞
　加圧反応槽に、エチレン含量４４モル％、ケン化度９９．９％のエチレン－ビニルアルコール共重合体（Ａ）２重量部およびＮ－メチル－２－ピロリドン８重量部を加えた。そして、１２０℃で加熱しながら２時間攪拌することにより、エチレン－ビニルアルコール共重合体（Ａ）を完全に溶解させた。これにエポキシ化合物（Ｂ）としてグリシドール０．４重量部を添加した後、１６０℃で４時間加熱した。加熱終了後、蒸留水１００重量部に生成物を析出させ、多量の蒸留水で充分にＮ－メチル－２－ピロリドンおよび未反応のグリシドールを洗浄し、変性エチレン－ビニルアルコール共重合体（Ｃ）を得た。さらに、得られた変性エチレン－ビニルアルコール共重合体（Ｃ）を、粉砕機で粒子径２ｍｍ程度に粉砕した後、再度多量の蒸留水で十分に洗浄した。洗浄後の粒子を、８時間室温で真空乾燥した後、２軸押出機を用いて２００℃で溶融し、ペレット化した。 <Synthesis of modified ethylene-vinyl alcohol copolymer (C)>
2 parts by weight of an ethylene-vinyl alcohol copolymer (A) having an ethylene content of 44 mol% and a saponification degree of 99.9% and 8 parts by weight of N-methyl-2-pyrrolidone were added to the pressurized reaction vessel. The ethylene-vinyl alcohol copolymer (A) was completely dissolved by stirring for 2 hours while heating at 120 ° C. After adding 0.4 weight part of glycidol as an epoxy compound (B) to this, it heated at 160 degreeC for 4 hours. After heating, the product is precipitated in 100 parts by weight of distilled water, and N-methyl-2-pyrrolidone and unreacted glycidol are thoroughly washed with a large amount of distilled water to obtain a modified ethylene-vinyl alcohol copolymer (C). Got. Further, the obtained modified ethylene-vinyl alcohol copolymer (C) was pulverized to a particle size of about 2 mm with a pulverizer, and then sufficiently washed with a large amount of distilled water again. The washed particles were vacuum-dried at room temperature for 8 hours, and then melted at 200 ° C. using a twin-screw extruder to be pelletized.
　得られた変性エチレン－ビニルアルコール共重合体（Ｃ）のペレットを用いて、４０ｍｍφ押出機（プラスチック工学研究所製ＰＬＡＢＯＲ　ＧＴ－４０－Ａ）とＴダイからなる製膜機を用いて、下記押出条件で製膜し、厚み２０μｍのフイルム状のインナーライナーを得た。
　形式：　　　　　　単軸押出機（ノンベントタイプ）
　Ｌ／Ｄ：　　　　　２４
　口径：　　　　　　４０ｍｍφ
　スクリュー：　　　一条フルフライトタイプ、表面窒化鋼
　スクリュー回転数：４０ｒｐｍ
　ダイス：　　　　　５５０ｍｍ幅コートハンガーダイ
　リップ間隙：　　　０．３ｍｍ
　シリンダー、ダイ温度設定：Ｃ１／Ｃ２／Ｃ３／アダプター／ダイ
　　＝１８０／２００／２１０／２１０／２１０（℃） Using the resulting modified ethylene-vinyl alcohol copolymer (C) pellets, a 40 mmφ extruder (PLABOR GT-40-A manufactured by Plastics Engineering Laboratory) and a T-die film forming machine were used for the following extrusion. A film was formed under the conditions to obtain a film-like inner liner having a thickness of 20 μm.
Type: Single screw extruder (non-vent type)
L / D: 24
Diameter: 40mmφ
Screw: Single-row full flight type, surface nitrided steel Screw rotation speed: 40rpm
Die: 550 mm wide coat hanger die Lip gap: 0.3 mm
Cylinder, die temperature setting: C1 / C2 / C3 / adapter / die = 180/200/210/210/210 (° C.)
　図１および２（ａ）に示すような構造を有し、上記インナーライナーを用いて、タイヤのサイズが１９５／６５Ｒ１５のタイヤを試作した。太さ１５デニール（１７ｄｔｅｘ）（φ４５μ）、長さ２．５ｍｍのナイロン製短繊維約３０ｇを、数万本／ｃｍ２で、このタイヤのタイヤ内周面の約７５％の領域に植毛加工して実施例タイヤを作製した。実施例タイヤ、および比較例タイヤのそれぞれにつき、空洞共鳴音を評価した。
　なお、比較例タイヤは、短繊維を設けない点以外についてはタイヤ構造に改変を要しないため、実施例タイヤに準ずるものとした。 A tire having a structure as shown in FIGS. 1 and 2 (a) and having a tire size of 195 / 65R15 was manufactured using the inner liner. Nylon short fibers with a thickness of 15 denier (17 dtex) (φ45μ) and length of 2.5 mm were planted at about tens of thousands of fibers / cm 2 in an area of about 75% of the tire inner peripheral surface. Example tires were prepared. The cavity resonance sound was evaluated for each of the example tire and the comparative example tire.
In addition, since the comparative example tire does not require modification to the tire structure except that the short fiber is not provided, it was assumed to be similar to the example tire.
　実施例タイヤおよび、比較例タイヤのそれぞれにつき６ＪＪ－１５のリムに組み付けて、充填内圧を２２０ｋＰａ、負荷質量を４．２５ｋＮとした。そして、それぞれのタイヤを、時速８０ｋｍ／ｈで、直径１．７ｍの鉄板表面を持つドラム試験機を用いて転動させ、上下方向タイヤ軸力を、図３に模式的に示すような方法で測定して評価した。その結果に基づいて予測した車内騒音の周波数スペクトルを図４に示す。 Example tires and comparative tires were each assembled on a 6JJ-15 rim, with a filling internal pressure of 220 kPa and a load mass of 4.25 kN. Each tire is rolled at a speed of 80 km / h using a drum testing machine having a steel plate surface with a diameter of 1.7 m, and the vertical tire axial force is measured in a manner schematically shown in FIG. Measured and evaluated. FIG. 4 shows the frequency spectrum of the in-vehicle noise predicted based on the result.
　図４の結果から、２２５Ｈｚ、２４０Ｈｚ付近に見られるピークが空洞共鳴によるものであるが、これらのピークにおいて５～７ｄＢの低減が見られ、大きな低減効果が得られている。 From the results of FIG. 4, the peaks seen in the vicinity of 225 Hz and 240 Hz are due to cavity resonance, but a reduction of 5 to 7 dB is observed in these peaks, and a large reduction effect is obtained.
　また、実施例タイヤ、および比較例タイヤのそれぞれを６ＪＪ－１５のリムに組み付けて、充填内圧を２２０ｋＰａとして、２０００ｃｃクラスの乗用車に装着した。そして、それぞれのタイヤを用いた場合について、２名が乗車した乗用車を、時速５０ｋｍ／ｈで、車速で荒れたアスファルト路を走行させ、ドライバーの耳元で騒音を測定した。
　この実施例においても、図４に示す結果と同等の空洞共鳴音の低減の効果を確認することができた。 In addition, each of the example tire and the comparative example tire was assembled to a 6JJ-15 rim, and the internal pressure was set to 220 kPa, and the tire was mounted on a 2000 cc class passenger car. Then, in the case of using each tire, a passenger car on which two people got on traveled on an asphalt road rough at a vehicle speed at a speed of 50 km / h, and noise was measured at the driver's ear.
Also in this example, it was possible to confirm the effect of reducing the cavity resonance sound equivalent to the result shown in FIG.
　１　　トレッド部
　２　　サイドウォール部
　３　　ビード部
　４　　ビードコア
　５　　カーカス
　６　　ベルト
　７　　トレッドゴム
　８　　サイドゴム
　９　　インナーライナー
　１０　短繊維
　１１　補助層 DESCRIPTION OF SYMBOLS 1 Tread part 2 Side wall part 3 Bead part 4 Bead core 5 Carcass 6 Belt 7 Tread rubber 8 Side rubber 9 Inner liner 10 Short fiber 11 Auxiliary layer

Claims (10)

  1. 　トレッド部と、一対のサイドウォール部と、一対のビード部と、各ビード部に埋設されたビードコア間にトロイド状に延在させた少なくとも一枚のカーカスプライからなるカーカスと、タイヤの内周面側に配設された、樹脂からなる層を含むインナーライナーとを具えてなる空気入りタイヤにおいて、
    　前記インナーライナーのタイヤ内周面側に短繊維を固着してなることを特徴とする空気入りタイヤ。     A tread portion, a pair of sidewall portions, a pair of bead portions, a carcass made of at least one carcass ply extending in a toroid shape between bead cores embedded in each bead portion, and an inner peripheral surface of the tire In a pneumatic tire comprising an inner liner including a resin layer disposed on the side,
    A pneumatic tire comprising short fibers fixed to a tire inner peripheral surface side of the inner liner.
  2. 　前記樹脂は、エチレン－ビニルアルコール共重合体とエポキシ化合物を反応させて得られる変性エチレン－ビニルアルコール共重合体からなる請求項１に記載の空気入りタイヤ。 The pneumatic tire according to claim 1, wherein the resin comprises a modified ethylene-vinyl alcohol copolymer obtained by reacting an ethylene-vinyl alcohol copolymer and an epoxy compound.
  3. 　前記短繊維は接着剤にて固着されてなる請求項１に記載の空気入りタイヤ。 The pneumatic tire according to claim 1, wherein the short fibers are fixed with an adhesive.
  4. 　前記短繊維のタイヤ内周面に固着されている領域の面積は、タイヤの内周面の表面積に対して２５％以上である請求項１に記載の空気入りタイヤ。 2. The pneumatic tire according to claim 1, wherein an area of the region of the short fibers fixed to the inner peripheral surface of the tire is 25% or more with respect to a surface area of the inner peripheral surface of the tire.
  5. 　前記短繊維は、前記短繊維のタイヤ内周面に固着されている領域において、１平方センチメートル当たりに１００本以上設けている請求項１に記載の空気入りタイヤ。 2. The pneumatic tire according to claim 1, wherein 100 or more of the short fibers are provided per square centimeter in a region where the short fibers are fixed to an inner peripheral surface of the tire.
  6. 　前記短繊維は、平均長さが０．５～１０ｍｍの範囲である請求項１に記載の空気入りタイヤ。 The pneumatic tire according to claim 1, wherein the short fibers have an average length in a range of 0.5 to 10 mm.
  7. 　前記短繊維は、平均直径が１～５００μｍの範囲である請求項１に記載の空気入りタイヤ。 The pneumatic tire according to claim 1, wherein the short fibers have an average diameter in the range of 1 to 500 µm.
  8. 　前記短繊維の固着されている領域は、短繊維群からなり、複数の短繊維群が互いに独立して固着されてなる請求項１に記載の空気入りタイヤ。 The pneumatic tire according to claim 1, wherein the region where the short fibers are fixed is composed of short fiber groups, and a plurality of short fiber groups are fixed independently of each other.
  9. 　トレッド部と、一対のサイドウォール部と、一対のビード部と、各ビード部に埋設されたビードコア間にトロイド状に延在させた少なくとも一枚のカーカスプライからなるカーカスと、タイヤの内周面側に配設された、樹脂からなる層を含むインナーライナーとを具えてなる空気入りタイヤにおいて、
    　前記インナーライナーのタイヤ内周面側に接着剤を塗布する工程と、接着剤を塗布した部位に短繊維を接着させる工程とを有することを特徴とする空気入りタイヤの製造方法。     A tread portion, a pair of sidewall portions, a pair of bead portions, a carcass made of at least one carcass ply extending in a toroid shape between bead cores embedded in each bead portion, and an inner peripheral surface of the tire In a pneumatic tire comprising an inner liner including a resin layer disposed on the side,
    A method for manufacturing a pneumatic tire, comprising: a step of applying an adhesive to a tire inner peripheral surface side of the inner liner; and a step of bonding a short fiber to a portion where the adhesive is applied.
  10. 　前記短繊維を、静電植毛加工によりタイヤ内周面に設ける請求項９に記載の空気入りタイヤの製造方法。 The method for producing a pneumatic tire according to claim 9, wherein the short fibers are provided on the inner peripheral surface of the tire by electrostatic flocking.
PCT/JP2012/003638 2011-06-03 2012-06-01 Pneumatic tire and method for manufacturing same WO2012164960A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2011125231A JP2012250635A (en) 2011-06-03 2011-06-03 Pneumatic tire and method for manufacturing the same
JP2011-125231 2011-06-03

Publications (1)

Publication Number Publication Date
WO2012164960A1 true WO2012164960A1 (en) 2012-12-06

Family

ID=47258829

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2012/003638 WO2012164960A1 (en) 2011-06-03 2012-06-01 Pneumatic tire and method for manufacturing same

Country Status (2)

Country Link
JP (1) JP2012250635A (en)
WO (1) WO2012164960A1 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014097557A1 (en) * 2012-12-19 2014-06-26 株式会社ブリヂストン Pneumatic tire, and method of manufacturing pneumatic tire
US20140224400A1 (en) * 2013-02-13 2014-08-14 Bridgestone Corporation Pneumatic tire
CN105008144A (en) * 2013-02-20 2015-10-28 株式会社普利司通 Pneumatic tire
EP2993063A4 (en) * 2013-05-01 2016-04-27 Bridgestone Corp Pneumatic tire
CN105829127A (en) * 2013-12-25 2016-08-03 株式会社普利司通 Side-Reinforced Run-Flat Tire

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5478745B1 (en) * 2013-02-20 2014-04-23 株式会社ブリヂストン Pneumatic tire and manufacturing method thereof
JP5478746B1 (en) * 2013-02-20 2014-04-23 株式会社ブリヂストン Pneumatic tire and manufacturing method thereof
JP6484951B2 (en) * 2014-08-04 2019-03-20 横浜ゴム株式会社 Pneumatic tire

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004082387A (en) * 2002-08-23 2004-03-18 Bridgestone Corp Method for producing pneumatic tire, pneumatic tire, and tire rim assembly
JP2011037399A (en) * 2009-08-18 2011-02-24 Yokohama Rubber Co Ltd:The Pneumatic tire and method for manufacturing same
JP2011105066A (en) * 2009-11-13 2011-06-02 Bridgestone Corp Inner liner and tire using the inner liner

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004082387A (en) * 2002-08-23 2004-03-18 Bridgestone Corp Method for producing pneumatic tire, pneumatic tire, and tire rim assembly
JP2011037399A (en) * 2009-08-18 2011-02-24 Yokohama Rubber Co Ltd:The Pneumatic tire and method for manufacturing same
JP2011105066A (en) * 2009-11-13 2011-06-02 Bridgestone Corp Inner liner and tire using the inner liner

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014097557A1 (en) * 2012-12-19 2014-06-26 株式会社ブリヂストン Pneumatic tire, and method of manufacturing pneumatic tire
JP2014118129A (en) * 2012-12-19 2014-06-30 Bridgestone Corp Pneumatic tire and production method thereof
CN104884269A (en) * 2012-12-19 2015-09-02 株式会社普利司通 Pneumatic tire, and method of manufacturing pneumatic tire
US20140224400A1 (en) * 2013-02-13 2014-08-14 Bridgestone Corporation Pneumatic tire
US9440500B2 (en) * 2013-02-13 2016-09-13 Bridgestone Corporation Pneumatic tire
CN105008144A (en) * 2013-02-20 2015-10-28 株式会社普利司通 Pneumatic tire
EP2960076A4 (en) * 2013-02-20 2016-11-02 Bridgestone Corp Pneumatic tire
EP2993063A4 (en) * 2013-05-01 2016-04-27 Bridgestone Corp Pneumatic tire
CN105829127A (en) * 2013-12-25 2016-08-03 株式会社普利司通 Side-Reinforced Run-Flat Tire
EP3088207A4 (en) * 2013-12-25 2016-12-21 Bridgestone Corp Side-reinforced run-flat tire
CN105829127B (en) * 2013-12-25 2017-12-08 株式会社普利司通 Side enhanced run-flat tire
US10099517B2 (en) 2013-12-25 2018-10-16 Bridgestone Corporation Side-reinforced run-flat tire

Also Published As

Publication number Publication date
JP2012250635A (en) 2012-12-20

Similar Documents

Publication Publication Date Title
WO2012164960A1 (en) Pneumatic tire and method for manufacturing same
JP4589615B2 (en) Inner liner for pneumatic tire and pneumatic tire
EP3093165B1 (en) Sealant tire and method for producing the sealant tire
JP5592616B2 (en) Film, inner liner for tire, and tire using the same
JP5039332B2 (en) Inner liner for pneumatic tire and pneumatic tire provided with the same
JP5591225B2 (en) Pneumatic tire
JP5461822B2 (en) tire
EP2058359B1 (en) Innerliner for tire and tire using the same
JP2006256557A (en) Tire for heavy load
JP2008024217A (en) Inner liner for pneumatic tire and pneumatic tire equipped with the same
JP4939863B2 (en) INNERLINER FOR PNEUMATIC TIRE, MANUFACTURING METHOD THEREOF, AND PNEUMATIC TIRE
JP2009190448A (en) Tire
JP5767862B2 (en) tire
JP5551414B2 (en) Inner liner and tire using the same
JP2014213839A (en) Pneumatic radial tire for passenger car
JP2009040117A (en) Tire
JP4468073B2 (en) Emergency pneumatic tires
JP2007276581A (en) Pneumatic tire
JP5736239B2 (en) tire
JP2007276587A (en) Tire
JP6144957B2 (en) Pneumatic radial tire for passenger cars
JP2006213300A (en) Pneumatic tire
JP4468074B2 (en) Run flat tire
JP5783806B2 (en) Tire and method for manufacturing the tire
JP2012158156A (en) Method for manufacturing pneumatic tire

Legal Events

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

Ref document number: 12792194

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12792194

Country of ref document: EP

Kind code of ref document: A1