JP2006231980A - Tire particle aggregate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire particle aggregate capable of improving anti-cutting property of a side wall, and sealing a damaged portion more surely. <P>SOLUTION: This tire particle aggregate 100 is an aggregate of a tire 1 mounted to a vehicle and a plurality of hollow particles 4 filled in a tire air chamber 3 blocked by the tire 1 and a rim 2 along with high pressure gas with over atmospheric pressure. The tire 1 is equipped with a carcass reinforcing layer 6R constituted by a predetermined cord (for example, organic fiber cord) and rubber at least one part of a side wall SW including a position of a tire maximum width TW. The hollow particles 4 have an approximately spherical shape made of a continuous phase and closed cells of resin. When inner pressure of the tire air chamber 3 is lowered, a re-expansion starting temperature (Ts2) is reached to expand the tire. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tire particle assembly which is an assembly of a tire mounted on a vehicle and a plurality of hollow particles filled with a high-pressure gas exceeding atmospheric pressure in a tire air chamber defined by the tire and the rim. About.

  Conventionally, many proposals have been made on tires that can run even in a state where the internal pressure of a tire chamber partitioned by the tire and the rim is reduced (so-called puncture state).

For example, a hollow particle filled with a predetermined gas (or air) is filled in a tire chamber together with a high-pressure gas exceeding atmospheric pressure, so that a hole is damaged due to trauma to the tire (hereinafter, A technique is disclosed in which the wounded part) is sealed with the hollow particles to delay the leakage of the high-pressure gas filled in the tire chamber (for example, Patent Document 1).
JP 51-126604 A

  However, in the above-described conventional technology, the hollow particles can seal the small scratched part, but it is difficult to seal the large scratched part, and the tire together with the high-pressure gas in the tire chamber from the scratched part. Sometimes it erupted out of the air chamber.

  In particular, when a tire is damaged (so-called side cut) due to contact of rocks or rubble with the sidewall, the damaged portion generally becomes large. As a result, a large amount of hollow particles are ejected out of the tire chamber (the damaged part cannot be sealed), and the vehicle may not be able to travel.

  Therefore, the present invention has been made in view of such a situation, and provides a tire particle aggregate capable of improving the cut resistance of the sidewall and more reliably sealing the damaged portion. With the goal.

  In order to solve the above-described problems, the present invention has the following features. First, a feature of the present invention is that a high-pressure gas exceeding atmospheric pressure is provided in a tire (tire 1) mounted on a vehicle and a tire chamber (tire chamber 3) defined by the tire and the rim (rim 2). A tire particle aggregate (tire particle aggregate 100) that is an aggregate of a plurality of hollow particles (hollow particles 4) filled together, and the tire includes a position of a tire maximum width (tire maximum width TW). A carcass reinforcing layer (carcass reinforcing layer 6R) composed of a predetermined cord (for example, an organic fiber cord) and rubber is provided on at least a part of the side wall (sidewall SW), and the hollow particles are made of a continuous phase made of resin. And a substantially spherical shape consisting of closed cells, and when the internal pressure of the tire chamber decreases, the gist is to expand by reaching a predetermined temperature (re-expansion start temperature (Ts2))

  The predetermined temperature (Ts2) is a re-expansion start temperature (Ts2) corresponding to the glass transition temperature of the resin. In addition, the substantially spherical shape includes shapes such as oval and ellipse because of influence on manufacturing.

  According to such a feature, when the internal pressure of the tire chamber decreases (in a puncture state), the hollow particles expand when the hollow particles reach a predetermined temperature (Ts2), so that the hollow particles are ejected from the damaged portion. Therefore, the damaged portion can be more reliably sealed, and the internal pressure restoration function can be reliably realized.

  Here, the internal pressure restoration function means that the high pressure gas filled in the tire chamber is compressed by the expansion of the hollow particles in a state where the internal pressure in the tire chamber is reduced. It is a function that can revive.

  In addition, the carcass reinforcement layer is provided on at least a part of the sidewall including the position of the maximum width of the tire, so that damage (cut wound, etc.) when the sidewall comes into contact with rocks and rubble is less likely to occur. Cutability is improved. That is, the carcass reinforcing layer keeps the size of the damaged part constant, so that the damaged part is not enlarged, and the hollow particles can seal the damaged part more reliably.

  In addition, since the carcass reinforcing layer is provided on at least a part of the sidewall, the sidewall is difficult to bend even when the internal pressure of the tire chamber is lowered, and the hollow particles are expanded after being damaged. During this time, the vehicle can travel (move) safely and reliably.

  According to the feature of the present invention, the carcass reinforcing layer may be provided on at least a part of the tread shoulder (tread shoulder TS) including at least a part of the sidewall and the tread end part (tread end part 10e). Good.

  According to a feature of the present invention, the tire includes a pair of bead portions (bead portions 5) including at least a bead core (bead core 5a), and a carcass folded around the bead core from the tread width direction inner side to the tread width direction outer side. And a carcass reinforcing layer integrally formed with a carcass folded portion (carcas folded portion 6A) of the carcass layer that is a portion folded from the inner side in the tread width direction to the outer side in the tread width direction around the bead core. It may be.

  According to a feature of the present invention, the tire includes a first carcass layer (carcass layer 6) serving as a tire skeleton, and the carcass reinforcing layer serves as a tire skeleton together with the first carcass layer. The carcass layer (carcass layer 6a) may be used.

According to the feature of the present invention, the following general formula (I)
Filling ratio of hollow particles = (particle volume value / tire chamber volume value) × 100 (I)
The filling rate of the hollow particles calculated by the formula (1) is 5 vol% or more and 80 vol% or less, and the particle volume value is the total volume of all the hollow particles filled in the tire chamber under the atmospheric pressure, a total amount (cm ^3), tire chamber volume value was adjusted to be filled with only air used pressure (kPa) in the tire chamber, when the charge air pressure is discharged until the atmospheric pressure Using the filled air discharge (cm ³ ), the following general formula (II)
Tire chamber volume value = (filled air discharge) / (internal pressure / atmospheric pressure) (II)
(Cm ³ ) obtained from The filling rate of the hollow particles is more preferably 70 vol% or less, further preferably 60 vol% or less, and most preferably 50 vol% or less.

  Further, according to the feature of the present invention, the hollow part pressure that is the internal pressure of the hollow particles may be 70% or more of the internal pressure of the tire chamber. The hollow part pressure is more preferably 80% or more of the internal pressure in the tire air chamber, more preferably 90% or more, and most preferably 100% or more.

  Moreover, according to the characteristic of this invention, 90-200 degreeC may be sufficient as predetermined | prescribed temperature (Ts2). The predetermined temperature (Ts2) is more preferably 110 ° C to 200 ° C, further preferably 130 ° C to 200 ° C, and most preferably 160 ° C to 200 ° C.

Further, according to the feature of the present invention, the average particle diameter of the hollow particle group which is a plurality of hollow particles filled in the tire chamber is 40 to 200 μm, and the average of the hollow particle group filled in the tire chamber is The true specific gravity may be 0.01 to 0.06 (g / cm ³ ).

Further, according to the characteristics of the present invention, the gas inside the hollow particles is nitrogen, air, a linear or branched aliphatic hydrocarbon having 2 to 8 carbon atoms and a fluorinated product thereof, and 2 to 8 carbon atoms. And fluorinated products thereof, and the following general formula (III):
R ¹ —O—R ² (III)
(Wherein R ¹ and R ² are each independently a monovalent hydrocarbon group having 1 to 5 carbon atoms, and part of the hydrogen atoms of the hydrocarbon group may be replaced with a fluorine primitive) It may be at least one gas selected from the group consisting of ether compounds.

  According to a feature of the present invention, the continuous phase of the hollow particles may consist of at least one of a polyvinyl alcohol resin, an acrylonitrile polymer, an acrylic polymer, and a vinylidene chloride polymer.

  Further, according to the feature of the present invention, the continuous phase of the hollow particles is composed of an acrylonitrile polymer, and the acrylonitrile polymer is an acrylonitrile polymer, an acrylonitrile / methacrylonitrile copolymer, an acrylonitrile / methyl methacrylate copolymer. And at least one of acrylonitrile / methacrylonitrile / methyl methacrylate terpolymer and acrylonitrile / methacrylonitrile / methacrylic acid terpolymer.

  In addition, according to the feature of the present invention, the first tire pressure drop alarm function that warns the decrease of the internal pressure in the tire chamber based on the direct measurement method of the pressure in the tire chamber by the tire pressure sensor (tire pressure sensor 14). May be provided.

  In addition, according to the feature of the present invention, even if the second tire pressure drop alarm function is provided to warn the internal pressure drop in the tire chamber based on the wheel speed detected by the wheel speed sensor (wheel speed sensor 15). Good.

  Further, according to the feature of the present invention, the average bulk specific gravity under the atmospheric pressure in the tire chamber is larger than the average true specific gravity of the hollow particles, and a large number of foams are mixed with the hollow particles and filled in the tire chamber. May be provided.

  According to the characteristics of the present invention, the foam has a substantially spherical shape with a diameter of 1 to 15 mm or a cubic shape with one side of 1 to 15 mm, and an average bulk specific gravity of 0.06 to 0.3 (g / cc) and may have closed cells or open cells.

  ADVANTAGE OF THE INVENTION According to this invention, while improving the cut resistance of a sidewall, the tire particle aggregate which can seal a damaged part more reliably can be provided.

(Configuration of tire particle aggregate)
Next, an example of the tire particle aggregate according to the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones. Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  FIG. 1 is a cross-sectional view showing a tire particle assembly 100 in the present embodiment. As shown in FIG. 1, a tire particle aggregate 100 is filled with a high-pressure gas exceeding atmospheric pressure in a tire chamber 3 defined by a tire 1 mounted on a vehicle and the tire 1 and a rim 2. It is an aggregate with a plurality of hollow particles 4.

  The tire 1 has a pair of bead portions 5 including a bead core 5a and a bead filler 5b. Specifically, a steel cord or the like is used for the bead core 5a constituting the bead portion 5.

  The tire 1 has a carcass layer 6 that is a skeleton of the tire 1. Details of the carcass layer 6 will be described later.

  An inner liner 7 that is a highly airtight rubber layer corresponding to a tube is provided inside the carcass layer 6 in the tire radial direction. A belt layer 8 is disposed outside the carcass layer 6 in the tire radial direction. Specifically, the belt layer 8 includes a first belt layer 8a located on the outer side in the tire radial direction of the carcass layer 6 and a second belt layer 8b located on the outer side in the tire radial direction of the first belt layer 8a. Has been.

  Further, a tread portion 10 that is in contact with the road surface is disposed on the outer side of the belt layer 8 in the tire radial direction.

  The rim 2 has a valve 12 that dams the hollow particles 4 in the tire air chamber 3 and allows only gas to pass outside the tire air chamber. As shown in FIG. 2, the valve 12 includes a filter 13 made of a predetermined fiber (for example, non-woven fabric).

  By attaching such a tire valve 12, it is possible to perform a gas replenishing operation without leaking the hollow particles 4 against a natural drop in the internal pressure of the tire chamber 3 during normal traveling, and the tire chamber can be simply The internal pressure of 3 can be maintained. Further, when the tire particle assembly 100 of the present invention is manufactured, the hollow particles 4 can be filled into the tire chamber 3 with one valve 12, so that a general-purpose rim having only one valve hole is used as it is. Can be used.

  The hollow particles 4 are filled in a tire air chamber 3 defined by the tire 1 and the rim 2 together with a high-pressure gas exceeding atmospheric pressure. The details of the hollow particles 4 will be described later.

  Here, as long as the tire 1 is a tire according to the general standards such as tires for various automobiles, tires for trucks and buses, for example, tires for passenger cars, the structure is not particularly limited.

  By the way, when the vehicle travels while the internal pressure of the tire chamber 3 decreases (so-called “running in a puncture state”), the internal pressure is restored by the mechanism of the hollow particles 4 to be described later, so that the driver notices that the puncture has occurred in some situations. There may not be. At this time, since the tire 1 is punctured due to trauma, the tire 1 may break down if it continues to travel, which is very dangerous.

  Therefore, the tire pressure sensor 14 is provided in the tire 1 (in the vicinity of the valve 12 in FIG. 1) as a function of warning (notifying) that the driver has punctured. The tire pressure sensor 14 warns a decrease in internal pressure in the tire chamber 3 based on a direct measurement method of the internal pressure of the tire chamber 3.

  Specifically, as shown in FIG. 3, the tire pressure sensor 14 detects that the internal pressure in the tire chamber 3 has decreased (so-called puncture) based on the direct measurement method of the internal pressure of the tire chamber 3. In this case, data related to the puncture is transmitted to the receiving unit 50a of the vehicle 50.

  When the receiving unit 50a of the vehicle 50 receives the data related to the puncture, the driver can be warned (notified) via the warning unit 50b.

  In the present embodiment, the function of warning (notifying) the driver that the vehicle has been punctured is not limited to the tire pressure sensor 14, and a wheel speed sensor may be used.

  For example, as shown in FIG. 3, the wheel speed sensor 15 in the anti-lock brake system warns (informs) the driver via the alarm unit 50b when detecting that puncture has occurred based on the detected wheel speed. . The wheel speed sensor 15 is not limited to the wheel speed sensor 15 in the antilock brake system, and a wheel speed sensor different from the wheel speed sensor in the antilock brake system may be used.

  In the present embodiment, the function of warning the driver using the tire pressure sensor 14 constitutes a first tire pressure drop warning function, and the wheel speed sensor 15 in the antilock brake system is used to notify the driver. The function for warning constitutes a second tire pressure drop warning function.

(Configuration of carcass layer)
Next, the configuration of the carcass layer 6 described above will be described.

  The carcass layer 6 is folded from the inner side in the tread width direction to the outer side in the tread width direction around the bead core 5a. Specifically, the carcass layer 6 is composed of a cord (for example, an organic fiber cord) and rubber. The cord is preferably arranged at 70 to 90 degrees with respect to the tire equator line.

  A carcass folded portion 6A, which is a portion folded around the bead core 5a outward in the tread width direction, extends to exceed the position of the tire maximum width TW via the sidewall SW. The carcass folded portion 6A constitutes a carcass reinforcing layer 6R provided on the sidewall SW including the position of the tire maximum width TW. That is, the carcass reinforcing layer 6R is integrated with the carcass folded portion 6A.

  As described above, the carcass folding portion 6A extends until it exceeds the position of the maximum tire width SW, so that it is difficult for trauma (cut flaws, etc.) when the side wall SW comes into contact with rocks or rubble, and cut resistance. Will improve.

  Here, the carcass folded portion 6A only needs to extend through the sidewall SW until it exceeds the position of the tire maximum width TW. That is, the carcass folded portion 6A only needs to extend to the “A” range via the sidewall SW.

  For example, as shown in FIG. 4, the carcass folded portion 6A may extend from the tire maximum width TW to exceed the “B” distance via the sidewall SW (further than the carcass folded portion 6A in FIG. 1). May extend). As a result, even when the internal pressure of the tire chamber 3 is reduced, the sidewall SW becomes more difficult to bend and travels (moves) safely and reliably after the damage until the hollow particles 4 described later expand. )can do.

  Further, as shown in FIG. 5, the carcass folded portion 6A may extend to the tread shoulder TS including the tread end portion 10e. Specifically, the carcass folded portion 6A may extend from the belt end portion 8e through the sidewall SW to exceed the “C” distance.

  As a result, even when the internal pressure of the tire chamber 3 is reduced, a tread shoulder ts1 (hereinafter referred to as a side portion ts1) that does not contact the road surface in normal traveling is less likely to contact the road surface, and therefore wears more than the tread portion 10. It is possible to suppress the occurrence of a burst at the side portion ts1 having poor durability.

  Note that the carcass reinforcing layer 6R is not necessarily integral with the carcass folded portion 6A, and may be constituted by a member different from the carcass layer 6.

  For example, as shown in FIG. 6, the carcass reinforcing layer 6 </ b> R that is a separate member from the carcass layer 6 may be provided on the outer side in the tread width direction of the carcass layer 6. Specifically, the carcass reinforcing layer 6R is provided at a position “D” extending from the sidewall SW including the position of the tire maximum width TW and the tread shoulder TS including the tread end portion 10e. Further, the carcass reinforcing layer 6R has the same structure as the carcass layer described above, that is, is constituted by a cord (for example, an organic fiber cord) and rubber.

  In addition, as shown in FIG. 7, the carcass layer 6a (second carcass layer) serving as the skeleton of the tire 1 together with the carcass layer 6 (first carcass layer) may constitute the carcass reinforcing layer 6R.

(Configuration of hollow particles)
Next, the configuration of the hollow particles 4 described above will be described.

  The hollow particles 4 have closed cells surrounded by a continuous phase made of a substantially spherical resin. For example, it is a hollow body having a particle size distribution in the range of about 10 μm to 500 μm, or a spongy structure including a large number of small chambers due to closed cells.

  That is, the hollow particles 4 are particles that enclose closed closed cells that do not communicate with the outside, and the number of closed cells may be singular or plural.

  In the present embodiment, the “inside closed cells of the hollow particle group” is abbreviated as “hollow part”. The hollow particles 4 having closed cells indicate that the hollow particles 4 have “resin shells” for enclosing the closed cells in a sealed state. Furthermore, the continuous phase by the above-mentioned resin refers to this “continuous phase on the component composition constituting the resin shell”. The composition of the resin shell will be described later.

  The hollow particle group, which is a plurality (a large number) of the hollow particles 4, is filled inside the tire chamber 3 together with the high-pressure gas, so that the “internal pressure” of the tire is partially increased under normal use conditions. In addition, when the tire is injured (hereinafter referred to as “injured”), it serves as a source of the function of restoring (recovering) the internal pressure lost in the tire chamber 3. This “internal pressure restoration function” will be described later.

  Here, “internal pressure” refers to “a tire chamber pressure value (gauge pressure value) for each mounting position specified by an automobile manufacturer for each vehicle”.

  Now, when the conventional tire 1 travels in a state where the internal pressure of the tire chamber 3 is reduced to the atmospheric pressure, the tire 1 is greatly bent by the load, and the side portion ts1 of the tread portion 10 of the tire 1 is grounded to the road surface, Since the inner liners 8 are in contact with each other, the carcass layer 6 that is the skeleton of the tire 1 is fatigued due to heat generated by friction and repeated bending deformation, and the wear scratches on the side part finally penetrate into the tire chamber 3. Will lead to damage.

  Therefore, in the present embodiment, when the gas in the tire chamber 3 leaks due to trauma, the minimum internal pressure of the tire chamber 3 necessary for the subsequent travel is appropriately applied to restore the lost internal pressure. The main purpose.

  In the following, when the gas in the tire chamber 3 leaks due to trauma, which is one of the main purposes, the minimum internal pressure of the tire chamber 3 necessary for the subsequent driving is appropriately applied, and the lost internal pressure is restored. It explains about making it. Therefore, in this embodiment, the tire chamber 3 partitioned by the tire 1 and the rim 2 is regarded as a pressure vessel.

  That is, the damaged part of the tire chamber 3 damaged by the puncture is temporarily sealed with a group of hollow particles filled in the tire chamber 3, and the pressure lost by functioning the hollow particles 4 is restored. To achieve this goal.

  Even if the internal pressure of the tire chamber 3 is reduced to the atmospheric pressure, it is important to function as a pressure vessel by demonstrating the function of recovering the internal pressure lost early (an internal pressure recovery function described later).

More specifically, the hollow particles 4 filled in the tire chamber 3 are represented by the following formula (I)
Filling rate of hollow particles 4 = (particle volume value / tire chamber 3 volume value) × 100 (I)
It is preferable that the filling rate of the hollow particles 4 calculated by the above is 5 vol% or more and 80 vol% or less.

Here, the particle volume value is a total amount (cm ³ ) of the total volume of the hollow particle group filled in the tire chamber 3 under the atmospheric pressure and the void volume around the particle, and can be calculated by the following method. .

First, the average bulk specific gravity of the hollow particles 4 under atmospheric pressure is determined. For example, it is calculated by measuring the weight of a known volume under atmospheric pressure. First, the hollow particles 4 are weighed in a graduated cylinder under atmospheric pressure, and vibration is applied in an ultrasonic aqueous solution, and the packing between the hollow particles 4 is stabilized, and the total volume of the hollow particles 4 (around the particles) The average bulk specific gravity under the atmospheric pressure is calculated by measuring the void volume) and the total weight of the hollow particles 4. That is, the average bulk specific gravity of the hollow particles 4 under atmospheric pressure is
Average bulk specific gravity of hollow particles under atmospheric pressure = (total weight of particles) / (total volume of particles)
It is.

Next, the total weight of the hollow particles 4 filled in the tire chamber 3 is measured, and divided by the average bulk specific gravity of the hollow particles 4 under atmospheric pressure described above, the “particles filled in the tire chamber 3” Volume "can be calculated. That is,
Particle volume = (total weight of particles filled in tire) / (average bulk specific gravity of particles under atmospheric pressure)
It is.

  In addition, the hollow particles 4 having a desired particle volume can be filled in the tire 1 by a method of filling the tire chamber 3 while measuring the particles in a container having a known volume.

Further, the tire chamber volume value is adjusted until the tire chamber 3 defined by the tire 1 and the rim 2 is filled with only air and adjusted to the use internal pressure (kPa), and then the filled air is changed to the atmospheric pressure. It is a value (cm ³ ) obtained from the following formula (II) using the discharged amount of filled air (cm ³ ) when discharged.

Tire chamber volume value = (filled air discharge) / (internal pressure / atmospheric pressure) (II)
In the formula (II), the internal pressure used is a gauge internal pressure (kPa), and the atmospheric pressure value is an absolute value (kPa) measured by a barometer. That is, the atmospheric pressure is represented by 0 [kPa] in terms of the gauge pressure, but the atmospheric pressure value itself changes every day, so the absolute value observed from the barometer at that time is used. Therefore, for example, when the atmospheric pressure at a certain time is 1013 hPa, 101.3 kPa is used as the absolute value of atmospheric pressure in the formula (II).

  Next, the reason why the filling rate of the hollow particles 4 is 5 vol% or more and 80 vol% or less will be described in order from the normal use to the puncture state.

  First, the case where the tire air chamber 3 is filled with a large number of hollow particles 4 and the tire air chamber 3 is further filled with high-pressure gas, and the internal pressure of the tire air chamber 3 is set to the use internal pressure will be described.

  In this embodiment, after the tire chamber 3 is filled with the hollow particles 4, the internal space 11 around the hollow particles 4, in other words, the internal pressure of the tire chamber 3 is a desired use internal pressure such as a specified vehicle internal pressure. Thus, it is important to fill a high-pressure gas such as air or nitrogen.

  When the tire chamber 3 is filled with the hollow particles 4 and further filled with gas, and the internal pressure of the tire chamber 3 is set to a desired internal pressure, the hollow portion pressure of the hollow particles (internal pressure in the closed cells) is initially set to the tire gas. Since it is less than the internal pressure of chamber 3, the particles are reduced in volume. The shape of the hollow particles 4 at this time is not a substantially spherical shape, but is a flattened and distorted shape from a spherical shape (a so-called collapsed rugby ball shape).

  When the vehicle starts running with the shape of the hollow particles 4 flattened and distorted, the hollow particles 4 collide with the hollow particles 4 and the inner surfaces of the tire 1 and the rim 2 as compared with the spherical shape. It becomes easy to destroy by the collision. That is, when the hollow particles 4 are flattened and distorted, the input due to the collision cannot be uniformly dispersed, resulting in a great disadvantage in terms of durability.

  On the other hand, the flattened and distorted hollow particles 4 are in a state where the volume is reduced due to the difference between the hollow portion pressure and the internal pressure of the tire chamber 3, but the tire chamber 3 (the void 11 around the particle) over a certain period of time. The internal pressure of the hollow particles 4, in other words, the internal pressure of the closed cells of the hollow particles 4 can be increased to about the internal pressure of the tire chamber 3. That is, since the flattened hollow particles 4 are deformed, a force is exerted on the shell portion to return to the original substantially spherical shape.

  Moreover, since the hollow part pressure of the flattened hollow particles 4 is lower than the internal pressure of the tire air chamber 3, in order to eliminate the internal pressure difference, the gas molecules in the tire air chamber 3 are shells of a continuous phase made of resin. And penetrates into the hollow portion of the particle. Furthermore, since the hollow part of the hollow particle 4 is a closed cell and the gas in it is filled with the gas resulting from the foaming agent, it is different from the gas in the tire chamber 3 (the void 11 around the particle). There is. In this case, the high-pressure gas in the tire chamber 3 permeates into the particle hollow portion while following the partial pressure difference of the gas as well as the above-described difference in internal pressure until the partial pressure difference is eliminated.

  Thus, since the high pressure gas in the tire chamber 3 penetrates into the hollow portion of the hollow particle 4 with time, the internal pressure of the tire chamber 3 is reduced by the amount permeated into the hollow portion. Therefore, in order to make up for the amount of the hollow particles 4 that have penetrated into the hollow portion, the tire of the present embodiment adjusted to the desired use internal pressure can be obtained by continuously applying the desired internal pressure after filling the high-pressure gas. it can.

  While the hollow part pressure of the hollow particles 4 approaches the internal pressure of the tire chamber 3 (the void 11 around the hollow particles 4), the particle volume once reduced is restored, and the particle shape is flattened and distorted. It will be restored from its shape to its original spherical shape. In the process of restoring this shape, the hollow portion pressure of the hollow particles 4 increases to at least 70% with respect to the internal pressure of the tire chamber 3, so that the particle shape changes from a flattened state to a substantially spherical shape. It can be revived, thereby ensuring the durability of the hollow particles described above.

  In this way, high-pressure gas is interposed around the hollow particles 4, and the load borne by the hollow particles 4 during normal travel can be reduced to a negligible level. Further, in the hollow particles 4 whose particle volume has been restored, the particle shape is restored to a substantially spherical shape, so that fatigue and breakage applied to the hollow particles 4 can be significantly reduced along with repeated deformation during tire rolling. As a result, the durability of the hollow particles 4 is not impaired. The range in which the durability of the hollow particles 4 is not impaired is that the pressure of the hollow part 4 is restored while the volume of the hollow particles 4 is restored in the desired high-pressure environment such as the internal pressure specified by the vehicle to be mounted. In the process of increasing, the hollow part pressure of the hollow particles 4 is preferably 70% or more of the internal pressure of the tire chamber 3. Furthermore, it is recommended to set a high value of 80% or more, 90% or more, and 100% or more.

  Here, in order for the hollow part pressure of the hollow particles 4 to be at least 70% with respect to the internal pressure of the tire chamber 3, the pressure of the void gas around the hollow particles 4 is set to at least the vehicle-designated internal pressure to be mounted, etc. What is necessary is to hold | maintain in the state raised to 70% or more with respect to the internal pressure of the desired tire air chamber 3, and just to pass appropriate time, continuing applying this pressure. Alternatively, the hollow particles 4 are filled in a pressure vessel different from the tire 1, and the internal pressure of the voids 11 around the hollow particles 4 is held at least 70% higher than the internal pressure of the tire chamber 3. The tire chamber 3 is filled with the surrounding particles together with the surrounding gas after the pressure is maintained in the pressure vessel for an appropriate time while the pressure is continuously applied and the hollow portion pressure of the hollow particles 4 is increased. Also, the desired tire particle aggregate 100 can be obtained.

  The appropriate holding time described above is set in consideration of the permeability of the void gas to the shell portion of the hollow particle 4, that is, the continuous phase of the hollow particle, and the partial pressure difference between the gas in the particle hollow portion and the void gas. do it.

  Appropriately select and adjust the type and pressure of the gas filled in the tire chamber 3 (the void 11 around the hollow particles 4) in accordance with the process of changing the mechanism, shape, and volume of the hollow particles 4 described above. Thus, the hollow part pressure of the hollow particles 4 can be set in a desired range.

  As described above, the hollow particles 4 in which the hollow portion pressure of the hollow particles 4 is 70% or more of the internal pressure of the tire air chamber 3 are filled in the tire air chamber 3, so that the internal pressure of the tire air chamber 3 is atmospheric pressure. When the vehicle travels from this state, it is necessary to realize that the internal pressure of the tire chamber 3 is restored to at least the internal pressure of the tire chamber that enables traveling for a certain distance.

  Next, the function of restoring the internal pressure lost in the tire chamber 3 described above (so-called “internal pressure recovery function”) will be described.

  In the tire particle assembly 100 in which the above-described hollow particle group is filled in the tire chamber 3, when the tire 1 is damaged, the high-pressure gas in the tire chamber 3 existing in the void 11 around the hollow particles 4 is outside the tire 1. As a result, the internal pressure of the tire chamber 3 decreases to an internal pressure similar to the atmospheric pressure. In the process of lowering the internal pressure of the tire chamber 3, the following occurs in the tire chamber 3.

  First, when the tire 1 is damaged and the internal pressure of the tire chamber 3 starts to decrease, a large number of hollow particles 4 seal the damaged portion that is the damaged tire portion, and the abrupt tire chamber 3 Suppresses the decrease in internal pressure.

  Here, in this embodiment, the hollow part pressure of the hollow particles 4 is specified to be at least 70% of the internal pressure of the vehicle-designated tire at the time of normal running use, but the sealing ability of the damaged part depends on the hollow part pressure. To do. That is, although it has been described above that a substantially spherical shape can be maintained if the hollow portion pressure is 70% or more, a good fluidity and elasticity can be expressed by maintaining the substantially spherical shape, so that the hollow portion pressure is low. Compared to the case, the sealing limit of the damaged part is greatly improved.

  Further, as the internal pressure of the tire chamber 3 decreases, the amount of deflection of the tire 1 increases and the tire chamber volume decreases. Further, when the internal pressure of the tire chamber 3 decreases, the tire is greatly bent, and the temperature of the tire chamber 3 starts to increase due to the heat generated by the tire 1 itself.

  On the other hand, the hollow part pressure of the hollow particles 4 existing under the use internal pressure described above (the bubble internal pressure in the closed cells) remains high after the damage, in other words, before the damage. Therefore, it exists in the tire chamber 3 while maintaining the particle volume and the hollow portion pressure. Therefore, when the tire rolls further, the temperature of the hollow particles increases as the temperature of the tire chamber 3 increases.

  When the hollow particle temperature exceeds the re-expansion start temperature of the hollow particle 4 (Ts2: corresponding to the glass transition temperature of the resin), the shell of the hollow particle 4 starts to soften. At this time, in addition to the pressure inside the hollow part of the hollow particle 4 being a high pressure according to the working internal pressure, the hollow part pressure is further increased due to the rise in the temperature of the hollow particle, so that the hollow particle 4 expands in volume, Since the gas in the void 11 around the hollow particle 4 is compressed, the internal pressure of the tire chamber 3 can be restored (recovered).

  That is, when the internal pressure of the tire chamber 3 decreases (so-called tire is damaged), the hollow particles 4 are re-expanded (expanded) by reaching the re-expansion start temperature “Ts2”. In the present embodiment, the re-expansion start temperature “Ts2” indicates a predetermined temperature.

  Further, in order to restore the internal pressure of the tire air chamber 3, the hollow air particles 4 whose hollow portion pressure is at least 70% of the use internal pressure are filled into the tire air chamber at a filling rate of 5 vol% or more and 80 vol% or less. It is important to keep it. The reason is shown below.

  When the filling rate of the hollow particles 4 is smaller than 5 vol%, the damaged portion can be sealed without any problem, but since the absolute amount of the hollow particles 4 is insufficient, it is difficult to obtain a sufficient recovery internal pressure. On the other hand, if the filling ratio of the hollow particles exceeds 80 vol%, some tires expand due to heat generation due to particle friction during normal high-speed running, and thus exceed the re-expansion start temperature (Ts2) of the hollow particles 4. The internal pressure restoration function, which is the main function of the present embodiment, may be lost during normal traveling.

  Further, in order to reliably realize the internal pressure recovery function, it is important to securely seal the damaged portion before the internal pressure recovery function is realized. That is, if the wound part is not completely sealed, the internal pressure that should have been restored will leak from the wound part, and the internal pressure obtained by the internal pressure restoration function can only temporarily contribute to the subsequent travel. In addition, the running performance after the tire is damaged may not be guaranteed.

  Since the hollow particle 4 is a particle having a low specific gravity and high elasticity due to the hollow structure, when the gas in the void 11 around the particle begins to leak from the damaged portion where the tire 1 has been damaged, the void 11 Riding the flow caused by the leakage of gas immediately gathers in the wounded part and instantly seals the wounded part (scratch). Thus, the sealing function of the damaged part by the hollow particles 1 is an essential function that supports the internal pressure restoration function of the present embodiment.

  As described above, when the tire air chamber 3 partitioned by the tire 1 and the rim 2 is filled with the hollow particles 4, the tire air chamber volume is reduced and the amount of deflection of the tire 1 is increased due to a decrease in the internal pressure after puncture. Thus, the increase in the temperature of the hollow particles 4 accompanying the increase in the temperature of the tire chamber 3 restores the internal pressure due to the expansion of the hollow particles 4, thereby realizing safe traveling after being damaged.

  By the way, although the friction between the hollow particles 4 in the tire particle aggregate 100 is small, it is generated even under normal traveling. However, in the region where the traveling speed is 100 km / h or less, the generated frictional heat itself is small, and the generated heat is radiated to the outside air, so that the temperature of the hollow particles 4 is uniform in the range below the re-expansion start temperature (Ts2). I'm fighting.

  However, in a high-speed region exceeding 150 km / h, and in an extremely hot environment where the temperature circulation of the outside air is extremely high, the generated heat of friction is increased, but the heat release to the outside air is insufficient, and the temperature of the hollow particles 4 Will rise significantly. If such a situation continues for a long time, the temperature of the hollow particles 4 exceeds the re-expansion start temperature (Ts2), so that the hollow particles expand. As a result, the above-mentioned “internal pressure restoration function at the time of puncture is realized. There is something that can't be done (loss).

  That is, the tire 1 generates centrifugal force corresponding to the speed by rotating at high speed. The hollow particle group filled in the tire chamber 3 is also subjected to the same centrifugal force. This centrifugal force is proportional to the weight of the hollow particles 4 and proportional to the square of the speed, and inversely proportional to the radius of the tire 1. Furthermore, since the tire 1 has a certain amount of bending caused by bearing a load, and the area in contact with the road surface is in a state parallel to the road surface, this ground contact area has no curvature, Centrifugal force is almost zero.

  As a result, the hollow particles 4 in the tire particle assembly 100 that rotates while bearing a load are subjected to centrifugal force as described above in a non-contact area that is not in contact with the road surface. On the other hand, the hollow particles 4 are placed in a “state where centrifugal force fluctuations are repeated” in which the centrifugal force is released at the moment of entering the ground contact region.

  Therefore, it is preferable to suppress the particle weight as much as possible for the hollow particle group filled in the tire chamber 3. That is, the average true specific gravity of the hollow particles 4 is preferably selected as small as possible.

  When the filling rate of the hollow particles 4 exceeds 80 vol%, some tires expand due to heat generation due to particle friction during normal high-speed running, and thus exceed the re-expansion start temperature (Ts2) of the hollow particles 4, Since the internal pressure restoration function which is the main function of this embodiment may be lost, it is not preferable. Therefore, the preferable range of the hollow particle filling rate is 5 vol% or more and 80 vol% or less, and further 70 vol% or less, 60 vol% or less, and 50 vol% or less.

  Moreover, about the average particle diameter of the hollow particle 4, a preferable range is the range of 40-200 micrometers. When the average particle size of the hollow particles 3 is less than 40 μm, the above-mentioned true specific gravity distribution spreads and the heat resistance is increased by the relative inertia force difference of the large true specific gravity particle group with respect to the small true specific gravity particle group and the frictional heat generation due to the motion thereof. Since it gets worse, it is not preferable. On the other hand, when the average particle size of the hollow particles 4 exceeds 200 μm, the traveling state when the particles collide with each other under normal traveling or when the internal pressure of the tire chamber 3 becomes atmospheric pressure due to puncture (scratching). In a situation where the hollow particle group directly supports the load in a so-called puncture state, there is a disadvantage that it selectively breaks from the particles on the large particle size side and cannot obtain the desired running performance after being damaged. This is not preferable because of fear.

  The average true specific gravity of the hollow particles 4 is preferably in the range of 0.01 to 0.06 g / cc. That is, if it is less than 0.01 g / cc, the durability of the hollow particles 4 under normal running is lowered, and the “internal pressure restoration function” may be lost during normal use. On the other hand, if it exceeds 0.06 g / cc, the centrifugal force fluctuation input in the normal high-speed running becomes large and the calorific value becomes large, which is not preferable.

  Incidentally, the inventors diligently studied the actual heat generation of the hollow particles 4 and achieved further improvement in heat resistance and durability of the hollow particles 4.

  Now, the hollow particles 4 are obtained by heating and expanding the “expandable resin particles” that are the raw material, and the expandable resin particles have an expansion start temperature “Ts1”. Further, when the hollow particles 4 obtained by the thermal expansion are heated again, the hollow particles 4 start to expand further, and there exists a re-expansion start temperature “Ts2” of the hollow particles.

  As a result of manufacturing the hollow particles 4 from many expansible resin particles and studying them, the inventors have used the expansion start temperature “Ts1” as an index of heat resistance, but as an index of heat resistance, It has been found that the re-expansion start temperature “Ts2” is appropriate.

  First, the expansion behavior in the case of expanding (heating expansion) the expandable resin particles was observed. Since the expandable resin particles are in a stage before expansion, the particle diameter is extremely small and the thickness of the resin shell is extremely thick compared to the state of the hollow particles 4. Therefore, the microcapsule has a high rigidity. Therefore, even if the continuous phase of the resin shell exceeds the glass transition point in the process of thermal expansion, the expansion force of the internal gas wins over the rigidity of the shell until the shell is softened to some extent by further heating. I can't. Therefore, the expansion start temperature “Ts1” is higher than the actual glass transition point of the shell.

  On the other hand, when the hollow particles are expanded again (reheat expansion), the thickness of the shell of the hollow particles 4 is extremely thin, and the rigidity of the hollow body is low. Therefore, since the expansion of the continuous phase of the shell exceeds the glass transition point in the process of heating and expansion, the re-expansion start temperature “Ts2” is positioned lower than the expansion start temperature “Ts1”.

  In the present embodiment, since the expansion characteristics of the hollow particles 4 that have been expanded are utilized instead of utilizing the expansion characteristics of the expandable resin particles, in order to discuss heat resistance (durability) Instead of the conventional expansion start temperature “Ts1”, the reexpansion start temperature “Ts2” should be used as an index.

  It is important that the re-expansion start temperature “Ts2” of the hollow particles 4 is 90 ° C. to 200 ° C. This is because if the re-expansion start temperature “Ts2” of the hollow particles 4 is lower than 90 ° C., depending on the selected tire size, the hollow particles 4 may start to re-expand before reaching the guaranteed speed of the tire. Because there is.

  On the other hand, when the re-expansion start temperature “Ts2” of the hollow particles 4 exceeds 200 ° C., the re-expansion start temperature even if a sudden temperature rise due to frictional heat generation of the hollow particles 4 occurs in the run flat running after the damage. “Ts2” may not be reached, and thus the intended “internal pressure restoration function” may not be sufficiently developed.

  Therefore, the range of the re-expansion start temperature “Ts2” is 90 ° C. to 200 ° C., preferably 110 ° C. to 200 ° C., more preferably 130 ° C. to 200 ° C., and most preferably 160 ° C. to 200 ° C. is there.

  As described above, when the upper limit value and the lower limit value described above are followed, by filling the hollow particles 4 having the re-expansion start temperature “Ts2”, the function of restoring the internal pressure is surely exhibited, and the heat resistance during high-speed running is increased. By improving the durability, “internal pressure recovery function retention” during normal driving is achieved.

Next, the gas in the hollow part of the hollow particles includes nitrogen, air, linear or branched aliphatic hydrocarbons having 2 to 8 carbon atoms and fluorinated products thereof, and alicyclic carbonization having 2 to 8 carbon atoms. Hydrogen and its fluorides and the following general formula (III):
R ¹ —O—R ² (III)
(Wherein R ¹ and R ² are each independently a monovalent hydrocarbon group having 1 to 5 carbon atoms, and part of the hydrogen atoms of the hydrocarbon group may be replaced by fluorine atoms) It is preferable that it is at least one gas selected from the group consisting of ether compounds represented by:

  In addition, the gas filled in the tire chamber 3 may be air, but when the gas in the hollow particles 4 is not a fluorinated product, a gas containing no oxygen, such as nitrogen or an inert gas, is used for safety. There may be.

  The method for obtaining the hollow particles 4 having closed cells is not particularly limited, but a general method is to obtain “expandable resin particles” using a foaming agent and to expand them by heating. Examples of the foaming agent include a method utilizing vapor pressure such as high-pressure compressed gas and liquefied gas, and a method utilizing a thermally decomposable foaming agent that generates gas by thermal decomposition. In particular, many thermally decomposable foaming agents are characterized by generating nitrogen, and the particles obtained by appropriately controlling the reaction of the expandable resin particles obtained by foaming by these have mainly nitrogen in the bubbles. It will be a thing.

  Preferred examples of the thermally decomposable foaming agent include dinitrosopentamethylenetetramine, azodicarbonamide, paratoluenesulfonylhydrazine and derivatives thereof, and oxybisbenzenesulfonylhydrazine.

  Hereinafter, a method of obtaining “expandable resin particles” that become the hollow particles 4 by utilizing the vapor pressure of high-pressure compressed gas and liquefied gas will be described.

  When polymerizing the continuous phase of the resin that forms the hollow particles 4, a linear or branched aliphatic hydrocarbon having 2 to 8 carbon atoms and a fluorinated product thereof, an alicyclic hydrocarbon having 2 to 8 carbon atoms and its At least one selected from the group consisting of a fluorinated product and the ether compound represented by the above general formula (III) is liquefied under high pressure as a foaming agent, and emulsified while being dispersed in a reaction solvent. This is a polymerization method.

  This makes it possible to obtain the “expandable resin particles” encapsulated in the above-described resin continuous phase using the gas component shown above as a liquid foaming agent. Can be obtained.

  Further, the surface of the “expandable resin particles” is coated with an anti-blocking agent such as silica particles, carbon black fine powder, antistatic agent, surfactant, oil agent, etc. Can be obtained.

  The following methods can be cited as a device for further enhancing the effect of the present embodiment. That is, in addition to the hollow particles 4 described above, “expandable resin particles” are partly added. Thereby, the internal pressure restoration function according to the present embodiment after the tire is damaged can be realized even earlier.

  However, since it becomes a factor of reducing the durability of the coexisting hollow particles 4, application in the following range is preferable. As a range in which the contradictory properties of both can be used well, the content of the “expandable resin particles” is 40 mass% or less, further the content is 30 mass% or less, 20 mass% with respect to the total particle weight filled in the tire chamber 3. Below, it is preferable to set it as 10 mass% or less.

  Further, in order to apply the necessary minimum internal pressure by the hollow particles 4 in a state where the internal pressure of the tire chamber 3 is reduced due to the damage, the gas sealed at a predetermined pressure in the hollow portion of the hollow particles 4 is transferred to the outside of the particles. In other words, it is important that the continuous phase of the resin corresponding to the shell part of the hollow particles has a property that gas is difficult to permeate.

  That is, the resin constituting the continuous phase is made of a material having low gas permeability, specifically, at least one of an acrylonitrile copolymer, an acrylic copolymer, and a vinylidene chloride copolymer. It is important. Since these materials have flexibility as hollow particles with respect to input due to tire deformation, they are particularly effective in this embodiment.

  Moreover, it is preferable to apply any one of an acrylonitrile polymer, an acrylic polymer, and a vinylidene chloride polymer to the continuous phase of the hollow particles 4. More specifically, the polymer constituting the polymer is a polymer selected from acrylonitrile, methacrylonitrile, methyl methacrylate, methacrylic acid, and vinylidene chloride, preferably acrylonitrile / methacrylonitrile / methyl methacrylate terpolymer, acrylonitrile. At least one selected from the group consisting of / methacrylonitrile / methacrylic acid terpolymer is advantageously suitable. Since all of these materials have a small gas permeability coefficient and are difficult for gas to permeate, the gas in the hollow part of the hollow particles hardly leaks to the outside, and the pressure in the hollow part can be appropriately maintained.

Further, the continuous phase of the hollow particles 4 has a gas permeability coefficient at 30 ° C. of 300 × 10 ⁻¹² (cc · cm / cm ² · s · cmHg) or less, preferably a gas permeability coefficient at 30 ° C. of 20 × 10 ^−12. (Cc · cm / cm ² · s · cmHg) or less, more preferably a gas permeability coefficient at 30 ° C. of 2 × 10 ⁻¹² (cc · cm / cm ² · s · cmHg) or less is recommended.

This is because the gas permeability coefficient of the inner liner in a normal pneumatic tire is at a level of 300 × 10 ⁻¹² (cc · cm / cm ² · s · cmHg) or less and has a sufficient internal pressure holding function. In view of the above, the gas permeation coefficient at 30 ° C. was set to 300 × 10 ⁻¹² (cc · cm / cm ² · s · cmHg) or less for the continuous phase of the particles. However, at this bus permeability coefficient level, it is necessary to replenish the internal pressure once every 3 to 6 months. Therefore, from the standpoint of maintenance, 20 × 10 ⁻¹² (cc · cm / cm ² · s · cmHg) or less, more preferably 2 × 10 ⁻¹² (cc · cm / cm ² · s · cmHg) or less is recommended.

  Here, according to the present embodiment, when the tire air chamber 3 is filled with the hollow particles 4, the average bulk specific gravity is the average of the hollow particles in order to enhance the sealing function of the damaged portion when the tire 1 is damaged. Means for mixing a large number of foams larger than the true specific gravity in the hollow particle group is effective.

  Specifically, it has a substantially spherical shape with a diameter of 1 to 15 mm or a cubic shape with one side of 1 to 15 mm, has independent or open cells, has an average bulk specific gravity of 0.06 to 0.3 g / cc, and By adding a large number of foams having a bulk specific gravity value larger than the average true specific gravity of the particles, the period (timing) for restoring the internal pressure is accelerated, and the running ability after the tire is damaged can be increased.

  That is, since the hollow particles 4 have a substantially spherical shape, the fluidity is high, so that the inside of the tire chamber 3 can be easily filled from the inlet having a small inner diameter such as the tire valve 12. On the other hand, when the tire is damaged, the hollow particles 4 try to blow out together with the high-pressure gas in the tire chamber 3 from the damaged portion to the outside of the tire and collect on the inner surface of the damaged portion.

  However, since the wound path from the inner surface of the scratched part to the outer peripheral surface of the tire is not a straight line but presents a complicated and complicated shape, the hollow particles 4 entering from the wounded part are obstructed by the path along the path. 4 will gather in a compressed state on the inner surface of the damaged part, and the damaged part is temporarily sealed. Here, provisionally sealing refers to a state in which the gas in the void 11 around the hollow particle 4 gradually leaks, although the hollow particle 4 itself does not leak.

  At that time, depending on the shape and size of the wound at the wounded part, provisional sealing with only hollow particles may be incomplete. In such a case, the level of sealing can be improved as follows by adding a large number of the foams described above.

  That is, in the tire air chamber 3 that is rolling, a centrifugal force corresponding to the speed is generated. Under the centrifugal force, the foam having a large bulk specific gravity is directed to the inner liner 8 side of the tire 1 and has a true specific gravity. The small hollow particles 4 are unevenly distributed to the side closer to the rotation center than the foam.

  In this state, even if there is an external damage that cannot be sealed with the hollow particles 4 alone, many foams are unevenly distributed in the vicinity of the inner liner 8 disposed on the inner surface of the tire 1. When the foam is about to blow out to the outside of the tire 1 and quickly comes into close contact with the inner surface of the damaged part, the damaged part is sealed, which is extremely effective.

  In particular, if the foam is a foam made of thermoplastic urethane with open cells, it is highly compressible and easily adheres to the shape of the tire damage, and as a result, the large damage area is extremely complicated and refined by the foam. By being able to do so, it is possible to change the dissipated flow path of the complicated and miniaturized gas to a state most suitable for sealing with the hollow particles 4, which is a very effective means.

(Action / Effect)
According to the tire particle assembly 100 of the present invention, when the internal pressure of the tire chamber 3 decreases (a puncture state), the hollow particles 4 expand by reaching the re-expansion start temperature (Ts2). Since the particles 4 block the high-pressure gas ejected from the damaged part (scratch), the damaged part can be more reliably sealed and the internal pressure restoration function can be reliably realized.

  In addition, by extending the carcass folding portion 6A beyond the position of the maximum tire width SW, it becomes difficult for trauma (cut flaws, etc.) when the sidewall SW comes into contact with rocks and rubble, and cut resistance is improved. To do.

  In addition, the carcass folded portion 6A (carcass reinforcing layer 6R) keeps the size of the damaged portion constant so that the damaged portion does not increase, and the hollow particles 4 can more reliably seal the damaged portion, Even when the internal pressure of the tire chamber 3 is lowered, the sidewall SW is more difficult to bend, and the vehicle can travel (move) safely and reliably after the damage until the hollow particles 4 expand.

  Furthermore, when the carcass reinforcing layer 6R (the carcass folded portion 6A or the carcass layer 6a) is provided on at least a part of the tread shoulder TS including the tread end portion 10e, the internal pressure of the tire chamber 3 is reduced. However, since the side portion ts1 is less likely to come into contact with the road surface, it is possible to suppress the occurrence of a burst at the side portion ts1.

  Next, in order to further clarify the effects of the present invention, test results performed using tires according to the following comparative examples and examples will be described. In addition, the data regarding each tire particle aggregate were measured on the conditions shown below.

・ Tire size: 195 / 65R15
・ Wheel size: 6.5J × 15
・ Vehicle type: FR vehicle (displacement 3.000cc)
-Load conditions: Constant product Hereinafter, the cut resistance of the tire particle aggregates according to Comparative Example 1, Example 1, Example 2, and Example 3 will be described. Table 1 shows the number of carcass layers (including the carcass reinforcing layer) and the cut resistance in the range A (see FIG. 1) in each tire particle aggregate. Each tire particle aggregate is the same except for the number of carcass layers (including carcass reinforcing layers) in the A range.

  As shown in Table 1, the tire particle assembly according to Comparative Example 1 has one carcass layer in the A range, and the tire particle assembly according to Example 1 has two carcass layers in the A range. In the tire particle assembly according to Example 2, there are three carcass layers in the A range, and in the tire particle assembly according to Example 4, there are four carcass layers in the A range.

<Cut resistance>
Each tire particle aggregate was mounted on a test vehicle and evaluated for cut resistance in the A range when the vehicle was driven on a rough road at a constant speed and a constant distance. In addition, evaluation of cut resistance is shown below.

○: Large cut resistance Δ: Medium cut resistance ×: Small cut resistance As a result, the tire particle aggregates according to Example 1, Example 2 and Example 3 are the same as the tire particle aggregate according to Comparative Example 1. It was found that the cut resistance was excellent when compared. That is, since the tire particle aggregate having two or more carcass layers (or carcass reinforcing layers) in the A range has excellent cut resistance and the damaged portion is less likely to become large, the hollow particles more reliably provide the damaged portion. It was found that it can be sealed.

It is a tread width direction sectional view showing a tire particle aggregate concerning an embodiment of the present invention. It is a figure which shows an example of the valve | bulb provided with the filter used together with the hollow particle with which the tire particle aggregate which concerns on embodiment of this invention is filled, and gas filling. It is a block diagram which shows the apparatus and alarm which alert | report the fall of the pressure of the tire chamber which concerns on embodiment of this invention. It is a tread width direction sectional view showing a tire particle aggregate concerning an embodiment of the present invention. It is a tread width direction sectional view showing a tire particle aggregate concerning an embodiment of the present invention. It is a tread width direction sectional view showing a tire particle aggregate concerning an embodiment of the present invention. It is a tread width direction sectional view showing a tire particle aggregate concerning an embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Tire, 2 ... Rim, 3 ... Tire air chamber, 4 ... Hollow particle, 5 ... Bead part, 5a ... Bead core, 5b ... Bead filler, 6, 6a ... Carcass layer, 6A ... Carcass folding part, 6R ... Carcass reinforcement Layer, 7 ... inner liner, 8 ... belt layer, 8a ... first belt layer, 8b ... second belt layer, 8e ... belt end, 10 ... tread portion, 10e ... tread end, 11 ... around the hollow particles Air gap, 12 ... valve, 13 ... filter, 14 ... tire pressure sensor, 15 ... wheel speed sensor, 50 ... vehicle, 50a ... receiving part, 50b ... alarm part, 100 ... tire particle aggregate

Claims (15)

A tire particle assembly that is an assembly of a tire mounted on a vehicle, and a plurality of hollow particles filled with a high-pressure gas exceeding atmospheric pressure into a tire chamber defined by the tire and the rim,
The tire includes a carcass reinforcing layer formed of a predetermined cord and rubber on at least a part of the sidewall including the position of the tire maximum width,
The hollow particles have a substantially spherical shape composed of a continuous phase made of resin and closed cells, and expand when a predetermined temperature (Ts2) is reached when the internal pressure of the tire chamber decreases. Tire particle aggregate.   The tire particle assembly according to claim 1, wherein the carcass reinforcing layer is provided on at least a part of the tread shoulder including at least a part of the sidewall and a tread end part. The tire is
A pair of bead portions including at least a bead core;
A carcass layer folded from the inner side in the tread width direction to the outer side in the tread width direction around the bead core;
The carcass reinforcing layer is integrated with a carcass folded portion of the carcass layer, which is a portion folded from the inner side in the tread width direction to the outer side in the tread width direction around the bead core. Item 3. The tire particle aggregate according to Item 2. The tire includes a first carcass layer serving as a skeleton of the tire,
3. The tire particle assembly according to claim 1, wherein the carcass reinforcing layer is a second carcass layer that becomes a skeleton of the tire together with the first carcass layer. 4. The following general formula (I)
Filling ratio of hollow particles = (particle volume value / tire chamber volume value) × 100 (I)
The filling rate of the hollow particles calculated by the following is 5 vol% or more and 80 vol% or less,
The particle volume value is a total amount (cm ³ ) of the total volume under atmospheric pressure of all the hollow particles filled in the tire chamber and the void volume around the particles,
The volume value of the tire chamber is the amount of filled air discharged (cm ³ ) when the tire chamber is filled with only air and adjusted to the working internal pressure (kPa) and then the filled air is discharged until the internal pressure reaches atmospheric pressure. ), The following general formula (II)
Tire chamber volume value = (filled air discharge) / (internal pressure / atmospheric pressure) (II)
The tire particle aggregate according to any one of claims 1 to 4, wherein the tire particle aggregate is a value (cm ³ ) obtained from the formula (1).   The tire particle assembly according to any one of claims 1 to 5, wherein a hollow part pressure that is an internal pressure of the hollow particles is 70% or more of an internal pressure of the tire chamber.   The tire particle assembly according to any one of claims 1 to 6, wherein the predetermined temperature (Ts2) is 90 to 200 ° C. The average particle diameter of the hollow particle group that is the plurality of hollow particles filled in the tire chamber is 40 to 200 μm,
8. The average true specific gravity of the hollow particle group filled in the tire chamber is 0.01 to 0.06 (g / cm ³ ). The tire particle aggregate described in 1. The gas inside the hollow particles includes nitrogen, air, a linear or branched aliphatic hydrocarbon having 2 to 8 carbon atoms and a fluorinated product thereof, an alicyclic hydrocarbon having 2 to 8 carbon atoms and a fluoro thereof. And the following general formula (III):
R ¹ —O—R ² (III)
(Wherein R ¹ and R ² are each independently a monovalent hydrocarbon group having 1 to 5 carbon atoms, and part of the hydrogen atoms of the hydrocarbon group may be replaced with a fluorine primitive) The tire particle aggregate according to any one of claims 1 to 8, wherein the tire particle aggregate is at least one gas selected from the group consisting of ether compounds represented by:   The continuous phase of the hollow particles is composed of at least one of a polyvinyl alcohol resin, an acrylonitrile-based polymer, an acrylic polymer, and a vinylidene chloride-based polymer. The tire particle aggregate according to 1.   The continuous phase of the hollow particles is composed of an acrylonitrile-based polymer, and the acrylonitrile-based polymer is an acrylonitrile polymer, an acrylonitrile / methacrylonitrile copolymer, an acrylonitrile / methyl methacrylate copolymer, or an acrylonitrile / methacrylonitrile / methyl methacrylate 3. The tire particle aggregate according to any one of claims 1 to 10, wherein the tire particle aggregate is at least one of an original copolymer and an acrylonitrile / methacrylonitrile / methacrylic acid ternary copolymer.   12. A first tire pressure drop alarm function for warning a decrease in internal pressure in the tire chamber based on a direct measurement method of the pressure in the tire chamber by a tire pressure sensor. The tire particle aggregate according to any one of the above.   13. The vehicle according to claim 1, further comprising a second tire pressure decrease warning function that warns of a decrease in internal pressure in the tire chamber based on a wheel speed detected by a wheel speed sensor. The tire particle aggregate as described.   An average bulk specific gravity under atmospheric pressure in the tire chamber is larger than an average true specific gravity of the hollow particles, and includes a large number of foams mixed with the hollow particles and filled in the tire chamber. The tire particle aggregate according to any one of claims 1 to 13.   The foam has a substantially spherical shape with a diameter of 1 to 15 mm or a cubic shape with one side of 1 to 15 mm, an average bulk specific gravity of 0.06 to 0.3 (g / cc), and has closed cells or communication. The tire particle aggregate according to claim 14, which has bubbles.

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