JP2011168183A - Tire for passenger car - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire for a passenger car capable of improving steering stability while achieving reduction of weight of the tire. <P>SOLUTION: The tire 10 for the passenger car includes beads 11 including a pair of bead cores 1 and a pair of bead fillers 3, carcasses 2 folded back from the inner side of the beads 11 to the outer side thereof, treads 13 at the outer side in the tire radial direction of the carcasses 2, and a pair of sidewall rubbers 12 between the beads 11 and the treads 13 at the outer side in the tire width direction of the carcasses 3. The height h1 of the bead fillers 3 from the upper end of the bead cores 1 is 40% or less of a height h4 of a tire cross section and a height h2 of an upper end of carcass folding-back parts 2B from the upper end of the bead cores 1 is 50% or less of h4 while assembled into a normal rim and filled with regular internal pressure, and a film or the like formed of a resin containing polyphenylene ether is arranged at the outer side in the tire width direction of the carcass folding-back parts 2B. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a passenger car tire (hereinafter, also simply referred to as “tire”), and more particularly, to a passenger car tire in which steering stability is improved while reducing the weight of the tire.

  In recent years, there has been an increasing demand for weight reduction of tires in order to improve the fuel efficiency of automobiles. As a method for reducing the weight of the tire, it is conceivable to reduce the rubber of the bead filler or reduce the amount of cord to be used by reducing the folded height of the ply cord. However, simply applying the above method significantly impairs the steering stability of the tire.

  In order to improve the handling stability, it is generally known that a highly rigid member is arranged near the bead part and the side wall part, but reducing the bead filler rubber and lowering the ply folding height Contrary to this. As a method for solving this problem, for example, Patent Document 1 discloses a method using a second bead filler. Patent Document 2 discloses a method of disposing a spiral belt-like cord member in the circumferential direction at a position higher than the first bead filler in the tire radial direction.

JP 2007-290299 A JP 2002-59714 A

  In order to apply the technique described in Patent Document 1, it is necessary to cure the rubber composition constituting the bead filler. In this case, a cured product is often obtained by reacting a curable resin such as phenol or epoxy and a curing agent such as amine during vulcanization, and amine is widely used as a ply material for passenger car tires. It has a function of causing a chemical reaction with the polyester fiber to deteriorate it, and it is not preferable to use it positively. Moreover, as long as it is used as a reinforcing material, it is desirable to have high rigidity, but in the case of a rubber composition, the rigidity is lower than that of a resin alone. On the other hand, although the technique described in Patent Document 2 is sufficient as rigidity, it is necessary to devise a tire molding method and is not easy. In any case, until now, it has been difficult to sufficiently improve steering stability by a simple method while reducing the weight of the tire.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a passenger car tire with improved steering stability while reducing the weight of the tire.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that the above-mentioned problems can be solved by setting the tire to the following configuration, and has completed the present invention.

That is, the passenger vehicle tire of the present invention includes a bead portion including a pair of bead cores and a bead filler disposed on the outer side in the tire radial direction of the bead core, a carcass folded back from the inside to the outside of the bead portion, A tire for a passenger car comprising a tread portion arranged on the outer side in the tire half direction, and a pair of sidewall rubbers arranged between the bead portion and the tread portion on the outer side in the tire width direction of the carcass, In a state where it is assembled in a normal rim and filled with normal internal pressure, the height h1 of the bead filler in the tire radial direction from the upper end of the bead core is 40% or less of the tire cross-section height h4, and the upper end of the bead core In the passenger car tire in which the height h2 of the upper end of the folded carcass is 50% or less of the tire cross-section height h4,
A film or a molded body made of a resin containing polyphenylene ether is disposed on the outer side in the tire width direction of the folded carcass.

  Here, the “regular rim” is a rim determined for each tire in the standard system including the standard on which the tire is based, for example, a standard rim for JATMA, “Design Rim” for TRA, Alternatively, in the case of ETRTO, “Measuring Rim” is set. In addition, “regular internal pressure” is the air pressure that each standard defines for each tire in the standard system including the standard on which the tire is based. The maximum air pressure is JATMA, and the table “TIRE LOAD LIMITS” is TRA. If it is ETRTO, the maximum value described in “AT VARIOUS COLD INFRATION PRESURES” is set to “INFLATION PRESSURE”.

  In the present invention, the height h3 in the tire radial direction from the upper end of the bead core to the upper end of the film or molded body is preferably 60% or less of the tire cross-sectional height. The polyphenylene ether is preferably poly-2,6-dimethyl-1,4-phenylene ether resin. Furthermore, it is preferable that at least one film or molded body is disposed concentrically in the tire circumferential direction. Furthermore, it is preferable that styrene-butadiene rubber is contained in the rubber adjacent to the film or molded body. Furthermore, the resin preferably contains a polystyrene resin that is compatible with the polyphenylene ether resin. Furthermore, the resin is preferably reinforced with a reinforcing material selected from the group consisting of long fibers, short fibers, and fillers. Furthermore, it is preferable that the film or the molded body is disposed in the tire by one or more methods selected from the group consisting of adjacent, hollowed out, and laminated. Furthermore, the cross-sectional shape of the molded body is preferably a shape selected from the group consisting of a triangle, a rectangle, a trapezoid, an ellipse, a circle, a crescent, a concave, and a convex.

  According to the present invention, it is possible to provide a tire with excellent steering stability while reducing the weight of the tire.

1 is a cross-sectional view in the width direction showing an example of a tire for a passenger car according to a preferred embodiment of the present invention. (A)-(c) is explanatory drawing which shows the arrangement position of the film or molded object which consists of resin containing the PPE film of the tire for passenger cars of Examples 1-3, respectively.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view in the width direction of an example of a tire for a passenger car of the present invention. The passenger car tire 10 shown in the figure has a pair of left and right bead portions 11 and sidewall portions 12, and a tread portion 13 connected between both sidewall portions 12, and extends between the bead portions 11 in a toroid shape. The carcass 2 including at least one sheet for reinforcing each of these parts, in the illustrated example, one carcass ply is provided. Further, a bead core 1 is embedded in each bead portion 11, and a bead filler 3 is disposed between the main body portion 2 </ b> A and the folded portion 2 </ b> B of the carcass 2 on the outer side in the tire radial direction.

  In the illustrated example, two belt layers 5 are arranged on the outer side in the tire radial direction of the carcass 2 in the tread portion 13. The belt layer 5 is formed by rubberizing steel cords arranged in parallel, and the cord angle can be 0 ° to 45 ° with respect to the tire circumferential direction. Moreover, the cap layer 6 and the layer layer 7 can be arrange | positioned as needed in the tire radial direction outer side of the belt layer 5. FIG. In the illustrated example, the cap layer 6 is disposed by one layer over the entire width of the belt layer 5 and rubberized organic fiber cords arranged substantially parallel to the tire circumferential direction. Further, in the illustrated example, the layer layer 7 is formed by rubberizing organic fiber cords that are disposed in both end regions of the belt layer 5 and arranged substantially parallel to the tire circumferential direction. Furthermore, a tread pattern is appropriately formed on the surface of the tread portion 13, and an inner liner is formed on the innermost layer of the tread portion 13 (not shown).

  In the passenger car tire of the present invention, the height h1 of the bead filler 3 in the tire radial direction from the upper end of the bead core 1 is 40% or less of the tire cross-section height h4 in a state in which the tire is assembled in a normal rim and filled with a normal internal pressure. In addition, the height h2 of the upper end of the folded portion 2B of the carcass 2 folded from the upper end of the bead core 1 is 50% or less of the tire cross-section height, and the polyphenylene is disposed outside the folded portion 2B of the carcass 2 in the tire width direction. It is important that a film 4 or a molded body (film in the illustrated example) made of a resin containing ether (PPE) is disposed. By arranging the film 4 or the molded body made of a resin containing PPE, it is possible to obtain high rigidity while being lightweight compared to the case where the rubber composition is arranged, and the weight reduction of the tire and the steering stability can be obtained. Improvements can be achieved at the same time. In addition, since the film 4 or the molded body is only stretched on the side at the end of the tire molding process and it is not necessary to use a curing agent, there is an advantage that it is a simple method.

  Here, when h1 is larger than 40% of h4, or when h2 is larger than 50% of h4, it is not possible to obtain advantages of weight reduction compared to tires generally used in the market today. Preferably h1 is 15-25% of h4 and h2 is 15-30% of h4.

  In general, in the method using such a resin, there is a problem of adhesion between the resin and the rubber. However, PPE has a property of being easily compatible with styrene, and styrene-butadiene copolymer generally used for tires. The styrene segment of rubber (SBR) diffuses into the PPE during heating by rubber vulcanization and mixes at the molecular level (Polymer Digest 2002.1 p90-105 Mitsuteru Rokuda: see). For this reason, it is possible to obtain strong adhesion without particularly performing an adhesion process. Therefore, in order to obtain sufficient adhesiveness, the styrene-butadiene copolymer rubber is preferably 10% by mass or more, particularly preferably 25% by mass or more in the rubber component. When this styrene-butadiene copolymer rubber is blended, other rubbers are not particularly limited. For example, natural rubber (NR), nitrile-butadiene copolymer rubber (NBR), polyisoprene rubber ( IR), polybutadiene rubber (BR), and isobutylene / isoprene rubber (IIR).

  The reason for using for passenger cars is as follows. First, in the case of large tires, the thickness is so thick that the vulcanization temperature is lower than that for passenger cars. This is because the lower temperature is disadvantageous for adhesion. Second, because the tensile fracture strength of PPE is about several tens to one hundred and several tens of MPa, it is not suitable for heavy loads. Thirdly, the reason why a reinforcing material such as an insert material is generally required is a tire for passenger cars.

  As the PPE used in the present invention, poly (1,4-phenylene ether) or a derivative thereof is preferable, and poly- (2,6-dimethyl-1,4-phenylene ether) is particularly preferable.

  In the present invention, the height h3 in the tire radial direction from the upper end of the bead core 1 to the upper end of the film 4 or the molded body is preferably 60% or less of the tire cross-section height h4. If h3 exceeds 60% of h4, the contribution to steering stability may not be clear. Preferably, it is 30 to 60% of h4.

  In the present invention, it is preferable that one or more films 4 or molded bodies containing a polyphenylene ether resin are arranged concentrically in the tire circumferential direction. Thereby, the reinforcement effect of a tire can be raised significantly.

  The resin containing PPE preferably contains polystyrene that is compatible with PPE. This is because the melt viscosity of the resin is reduced by being compatible with polystyrene, and it becomes easy to form into a film or the like.

  Furthermore, a copolymer comprising two or more monomers containing PPE as a structural unit, and for the purpose of improving workability, for example, by grafting or block copolymerization of a vinyl aromatic compound such as polystyrene and polyphenylene ether Modified PPE is also included. In the present invention, in order to obtain a better effect, it is preferable that 50% by mass or more of PPE is contained in the resin. Furthermore, additives such as plasticizers and stabilizers can be appropriately blended in the resin as desired.

  The film 4 and the molded body according to the present invention have an advantage that the selection range of the width and thickness of the reinforcing material is wider than that of the conventional one. In other words, a conventional tire reinforcing material requires a cutting process, and it has been difficult to produce a narrow reinforcing layer because it has to be cut without destroying the properties of the fiber material inside the reinforcing layer. This is because, in the form of the film 4 or the molded body as in the invention, such a restriction is hardly received.

  Furthermore, tire reinforcing materials (especially woven fabrics) made of conventional fiber materials are often bulky and further require a calendering process in addition to the thickness of the reinforcing material itself. However, in the present invention, since such a calendar is not required, the thickness of the additional rubber can be omitted. Thereby, like the film 4, it becomes advantageous for thickness reduction and weight reduction. In addition, the reinforcing material of the present invention is less likely to be a fracture nucleus and is advantageous not only in terms of durability, but also advantageous in that the selection of application positions is widened because it is less likely to be a fracture nucleus.

  In this invention, it is preferable that the film 4 or a molded object is a structure formed by adjoining, hollowing out, and laminating | stacking in a tire. In the prior art, when a highly rigid material is arranged near the bead portion and the side portion, the ride comfort level may be lowered. However, if it is reinforced with resin as in the present invention, it is possible to suppress the influence on the riding comfort level by arranging not only a single piece in the tire but also adjacent, hollow, laminated, etc. .

  Moreover, the molded object which concerns on this invention can give a change to a reinforcement effect by changing the cross-sectional shape (thickness). For example, when a gradually higher reinforcement effect is required from the inside in the radial direction of the tire to the outside, the conventional reinforcing material can only be laminated by adding another narrow reinforcing layer on the outside in the radial direction of the tire. Although there was no method, in the present invention, if the cross-sectional shape of the molded body is, for example, an acute triangle, and the base of the acute triangle is located on the outer side in the radial direction of the tire, the upward reinforcing effect can be easily achieved. It becomes possible to make it higher. In addition, the cross-sectional shape of the reinforcing material can be appropriately selected from a rectangular shape, a trapezoidal shape, an elliptical shape, a circular shape, a crescent shape, a concave shape, a convex shape, and the like according to applications. Reinforcement using such a reinforcing material is possible only when the resin used in the present invention is sufficiently bonded to rubber.

  Furthermore, in the present invention, long fibers or short fibers such as organic fibers, glass fibers and ceramic fibers, and fillers can be blended in the resin, and the strength and elastic modulus can be appropriately increased. Moreover, the film 4 or the molded body according to the present invention can have a planar shape of a waveform such as a waveform, a saw shape, or a triangle.

  In the passenger car tire of the present invention, it is only important to arrange the resin containing PPE in the above range, and other details of the tire structure and materials of each member are not particularly limited, and are conventionally known. It can be configured by appropriately selecting from those.

  For example, in the tire of the present invention, a tread pattern is appropriately formed on the surface of the tread portion 13, and an inner liner (not shown) is formed on the innermost layer. In the tire of the present invention, as the gas filled in the tire, normal or air having a changed oxygen partial pressure, or an inert gas such as nitrogen can be used.

Hereinafter, the present invention will be described in detail based on examples.
Example 1
A film 4 made of a resin containing PPE having a thickness of 0.8 mm is applied to a tire for a passenger car having a tire size of 205 / 55R16 (carcass ply: polyester 1670 dtex / 2, 1 ply) of the type shown in FIG. They were arranged concentrically at the positions shown in (a). Here, h1 to h4 in Table 1 and FIG. 2 are values when the tire is incorporated into a rim of size 6.5JJ × 16 and the internal pressure is 210 kPa, and h1 is the bead filler 3 from the upper end of the bead core 1. , H2 is the height from the upper end of the bead core 1 to the upper end of the folded portion 2B of the carcass 2, and h3 is the height in the tire radial direction from the upper end of the bead core 1 to the upper end of the film 4. H4 is the tire cross-section height. These conditions are summarized in Table 1. In addition, as a resin containing PPE, Daicel Tegusa Co., Ltd. Best Run 1900 was used.

(Example 2)
A tire was manufactured in the same manner as in Example 1 except that the film containing PPE of Example 1 was formed into a molded body 14 formed of a resin containing PPE as shown in FIG. The shape of the molded body 14 is concentric, and its cross-sectional shape gradually increases in thickness from the lower end of the molded body 14 toward the outside in the radial direction, reaching a maximum thickness of 2 mm at 12 mm from the lower end of the molded body 14. Thereafter, the thickness gradually decreases over 43 mm. The arrangement position of the molded body 14 is as shown in Table 1 and FIG. As a resin containing PPE, Bestell 1900GF20 manufactured by Daicel Tegusa Co., Ltd. was used.

(Example 3)
A tire was manufactured in the same manner as in Example 1 except that the film containing PPE of Example 1 was formed into a molded body 24 formed of a resin containing PPE as shown in FIG. The shape of the molded body 24 is such that three molded bodies 24 having a thickness of 1.3 mm and a height of 12 mm are arranged concentrically in the tire radial direction at a pitch of 3 mm. The arrangement position of the molded body 24 is as shown in Table 1 and FIG. As a resin containing PPE, Bestell 1900GF20 manufactured by Daicel Tegusa Co., Ltd. was used.

(Comparative Example 1 and Comparative Example 3)
A tire was produced in the same manner as in Example 1 except that no film or molded body made of a resin containing PPE was disposed.

(Comparative Example 2)
A tire was manufactured in the same manner as in Example 1 except that the arrangement position of the film containing the PPE of Example 1 was changed. The arrangement position of the film is as shown in Table 1. As a resin containing PPE, Bestell 1900GF20 manufactured by Daicel Tegusa Co., Ltd. was used.

<Steering stability and ride comfort>
Four tires obtained from the actual vehicle were attached, and the vehicle was run straight at a speed of 40 to 120 km / hour and lane change was performed. At that time, Comparative Example 1 was used as a reference. The higher the number, the better the result.

  From Table 1, it can be seen that the passenger car tire of the present invention has improved steering stability while reducing the weight.

1 Bead core 2 Carcass (2A body part, 2B folded part)
3 Bead Filler 4 Film 5 Belt Layer 6 Cap Layer 7 Layer Layer 10 Passenger Car Tire 11 Bead Part 12 Side Wall Part 13 Tread Part 14, 24 Molded Body

Claims (9)

A bead portion including a pair of bead cores and a bead filler disposed on the outer side in the tire radial direction of the bead core, a carcass folded back from the inside of the bead portion, and a tread portion disposed on the outer side in the tire half direction of the carcass And a tire for a passenger car including a pair of sidewall rubbers disposed between the bead portion and the tread portion on the outer side in the tire width direction of the carcass, and is incorporated in a regular rim and filled with a regular internal pressure. In this state, the height h1 of the bead filler in the tire radial direction from the upper end of the bead core is not more than 40% of the tire cross-section height h4, and the height h2 of the folded upper end of the carcass from the upper end of the bead core. In a passenger car tire in which the tire cross-section height h4 is 50% or less,
A passenger car tire characterized in that a film or a molded body made of a resin containing polyphenylene ether is arranged on the outer side in the tire width direction of the folded carcass.   The tire for a passenger car according to claim 1, wherein a height h3 in a tire radial direction from an upper end of the bead core to an upper end of the film or the molded body is 60% or less of a tire cross-sectional height h4.   The tire for passenger cars according to claim 1 or 2, wherein the polyphenylene ether is poly-2,6-dimethyl-1,4-phenylene ether resin.   The tire for passenger cars as described in any one of Claims 1-3 by which the said film or a molded object is arrange | positioned 1 or more concentrically at the tire circumferential direction.   The tire for passenger cars as described in any one of Claims 1-4 in which the styrene-butadiene rubber is contained in the rubber adjacent to the said film or a molded object.   The tire for passenger cars as described in any one of Claims 1-5 in which the said resin contains the polystyrene resin compatible with polyphenylene ether resin.   The tire for a passenger car according to any one of claims 1 to 6, wherein the resin is reinforced with a reinforcing material selected from the group consisting of long fibers, short fibers, and fillers.   The tire for a passenger car according to any one of claims 1 to 7, wherein the film or the molded body is arranged in the tire by one or more methods selected from the group consisting of adjacent, hollowed out, and laminated.   9. The cross-sectional shape of the molded body is a shape selected from the group consisting of a triangle, a rectangle, a trapezoid, an ellipse, a circle, a crescent, a concave, and a convex. Tires for passenger cars.

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