JP2006188100A - Tire-particle assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire-particle assembly, capable of restricting grounding of a side wall part after flat tire, and allowing stable travel even after flat tire. <P>SOLUTION: This tire-particle assembly is an assembly of a tire having a belt layer, and a plurality of hollow particles charged in a tire air chamber parted by the tire and a rim with compression gas exceeding atmospheric pressure. The tire comprises at least one belt reinforcing layer covering a plurality of cords disposed in parallel at about 90° to a tire equator, disposed inward to the tire diametric direction or outward to the tire diametric direction of the belt layer. The hollow particle is roughly shaped like a ball comprising a continuous phase of resin and separate bubbles. In case where the inner pressure of the tire air chamber is lowered, it expands when reaching a prescribed temperature Ts2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tire particle assembly which is an assembly of a tire having a belt layer and a plurality of hollow particles filled in a tire air chamber partitioned by a tire and a rim together with a high-pressure gas exceeding atmospheric pressure.

  Conventionally, many proposals have been made on so-called safety tires that can travel even in a puncture state.

For example, a pneumatic tire is known in which particles having closed cells maintained at a pressure higher than atmospheric pressure are inserted into a tire chamber (for example, Patent Document 1). A pneumatic tire in which particles having closed cells held at a pressure higher than the atmospheric pressure are inserted into the tire chamber is filled with the particles when the tire is punctured. However, the vehicle can travel over a certain distance.
JP 2003-118332 A

  However, when the particles block the wound part as described above, if the wound part is large or the like, it takes a longer time than usual to completely seal the wound part. As the pressure continues to decrease, the deflection proceeds, so that the sidewall portion may be grounded and the sidewall portion may be damaged. Here, if the sidewall portion is greatly damaged, it becomes difficult to block the damaged portion with the particles, and it may be impossible to travel a certain distance after puncture.

  Then, in view of the said subject, this invention makes it a subject to provide the tire particle aggregate which suppresses that a side wall part touches down after puncture and can obtain the stable driving | running | working after puncture.

  As a result of intensive investigations to solve the above-described situation, the inventors suppressed the ground contact of the sidewall portion when the gas in the tire chamber leaks due to damage, and obtains stable running even after puncture. It has been found that this is necessary, and the present invention has been completed.

  First, the first feature of the present invention is an aggregate of a tire having a belt layer and a plurality of hollow particles filled in a tire air chamber defined by the tire and the rim together with a high-pressure gas exceeding atmospheric pressure. In the tire particle assembly, the tire includes at least one belt reinforcing layer in which a plurality of cords arranged in parallel with each other at about 90 ° with respect to the tire equator line are covered with rubber. The hollow particles, which are arranged on the outer side in the direction, have a substantially spherical shape composed of a continuous phase and closed cells made of resin, and expand when a predetermined temperature (Ts2) is reached when the internal pressure of the tire chamber decreases. Is the gist.

  According to such a feature, when the internal pressure of the tire chamber decreases, the hollow particles expand by reaching a predetermined temperature (Ts2), so that the function of restoring the internal pressure can be surely exhibited at the time of puncture. .

  Here, the function of restoring the internal pressure of the tire after being injured is a high-pressure gas filled in the tire chamber by the expansion of the hollow particles when the internal pressure in the tire chamber is reduced to the atmospheric pressure (a puncture state). This is a function that can restore the internal pressure of the tire chamber.

  Here, the predetermined temperature (Ts2) is a re-expansion start temperature corresponding to the glass transition temperature (Ts2) of the resin.

  In addition, since the hollow particles have a substantially spherical shape, it is possible to prevent the hollow particles from hitting the wall surface of the tire chamber and the like due to centrifugal force during running and damaging the hollow particles. As a result, the hollow particles can reliably exhibit the function of restoring the internal pressure after being damaged.

  In addition, since at least one belt reinforcing layer in which a plurality of cords arranged in parallel at about 90 ° with respect to the tire equator line are covered with rubber is disposed on the inner side in the tire radial direction or the outer side in the tire radial direction of the belt layer, When the tire is punctured, it is possible to suppress the tread portion from being bent, thereby preventing the sidewall portion from being grounded. Here, since the plurality of cords are juxtaposed at about 90 ° with respect to the tire equator line, the force for suppressing the tread portion bent in the tire radial direction is the largest.

  As described above, since the sidewall portion is prevented from being grounded, damage to the sidewall portion can be prevented, and the hollow particles can surely exhibit the function of restoring the internal pressure.

  The second feature of the present invention relates to the first feature of the present invention, and is summarized in that the width of the belt reinforcing layer is 50% or more of the maximum width of the belt layer.

The third feature of the present invention relates to the first feature or the second feature of the present invention, and 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 and the void volume around the particles. 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)
The gist is the value (cm ³ ) obtained from

  The fourth feature of the present invention relates to the first feature to the third feature of the present invention, and is that the hollow portion pressure, which is the internal pressure of the hollow particles, is 70% or more of the internal pressure of the tire chamber. To do.

  The fifth feature of the present invention relates to the first feature to the fourth feature of the present invention, and is summarized in that the predetermined temperature (Ts2) is 90 to 200 ° C.

A sixth feature of the present invention relates to the first feature to the fifth feature of the present invention, and the average particle size of the hollow particle group which is a plurality of hollow particles filled in the tire chamber is 40 to 200 μm. In summary, the average true specific gravity of the group of hollow particles filled in the tire chamber is 0.01 to 0.06 (g / cm ³ ).

The seventh feature of the present invention relates to the first feature to the sixth feature of the present invention, and the gas inside the hollow particles is nitrogen, air, linear or branched carbon having 2 to 8 carbon atoms. Aliphatic hydrocarbons and fluorinated products thereof, alicyclic hydrocarbons having 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 by fluorine atoms) And at least one gas selected from the group consisting of ether compounds.

  The eighth feature of the present invention relates to the first feature to the seventh feature of the present invention, and the continuous phase of the hollow particles is a polyvinyl alcohol resin, an acrylonitrile polymer, an acrylic polymer, and a vinylidene chloride polymer. It consists of at least 1 type of these.

  A ninth feature of the present invention relates to the first feature to the eighth feature of the present invention, wherein the continuous phase of the hollow particles is composed of an acrylonitrile polymer, and the acrylonitrile polymer is an acrylonitrile polymer, acrylonitrile. And / or a methacrylonitrile / methacrylonitrile copolymer, an acrylonitrile / methyl methacrylate copolymer, an acrylonitrile / methacrylonitrile / methyl methacrylate terpolymer, and an acrylonitrile / methacrylonitrile / methacrylic acid terpolymer. To do.

  A tenth feature of the present invention relates to the first feature to the ninth feature of the present invention, and warns of 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 gist is to provide a first tire pressure drop warning function.

  An eleventh feature of the present invention relates to the first feature to the tenth feature of the present invention, and is based on the wheel speed detected by the wheel speed sensor, and a second tire pressure that warns of a decrease in internal pressure in the tire chamber. The gist is to provide a lowering alarm function.

  A twelfth feature of the present invention relates to the first feature to the eleventh feature of the present invention, wherein the average bulk specific gravity under atmospheric pressure in the tire chamber is larger than the average true specific gravity of the hollow particles, and the hollow particles And a large number of foams filled in the tire chamber.

  A thirteenth feature of the present invention relates to the twelfth feature of the present invention, wherein 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. It is 0.06 to 0.3 (g / cc), and it is summarized as having closed cells or open cells.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that a sidewall part touches down after puncture, and can provide the tire particle aggregate which can obtain the stable driving | running after puncture.

(Tire particle assembly)
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 shows a tire particle assembly 100 in the present embodiment. As shown in FIG. 1, a tire particle assembly 100 includes a tire 1 having a belt layer, and a tire chamber 3 partitioned by the tire 1 and the rim 2 and filled with a plurality of high-pressure gases exceeding atmospheric pressure. It is an aggregate with the 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 folded from the inner side in the tire width direction to the outer side in the tire width direction around the bead core 5a. The carcass layer 6 is obtained by coating a plurality of cords arranged in parallel at 70 to 90 ° with a rubber with respect to the tire equator line.

  The tire 1 is a portion that is most bent during running of the tire, and has a sidewall portion 7 for protecting the carcass layer.

  An inner liner 8 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 9 is disposed on the outer side of the carcass layer 6 in the tire radial direction. In the figure, two belt layers 9 of a belt layer 9a and a belt layer 9b are arranged.

  A belt reinforcing layer 16 is disposed on the inner side in the tire radial direction or the outer side in the tire radial direction of the belt layer 9. In the figure, the belt reinforcing layer 16 is disposed on the outer side in the tire radial direction of the belt layer 9. The belt reinforcing layer 16 will be described later.

  Further, a tread portion 10 that is in contact with the road surface is disposed on the outer side in the tire radial direction of the belt reinforcing layer 16.

  The rim 2 is provided with 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 decrease in the internal pressure of the tire chamber 3 during normal running, and the tire chamber 3 can be simply The internal pressure 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 only one valve 12, so that a general-purpose rim having only one valve hole is provided. It can be used as it is.

  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 is lowered (so-called puncture), the internal pressure is restored by the mechanism of the hollow particles 4 described later, so that the driver notices that the puncture occurred depending on the situation. There may not be. In addition, since the tire 1 is punctured due to trauma, the tire 1 may break down if it continues to travel as it is, which is very dangerous.

  Therefore, a tire pressure sensor 14 is disposed in the vicinity of the valve 12 as a function for 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 alerted (notified) via the alarm 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 the puncture 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 15 in the antilock brake system may be used.

  In the present embodiment, the function capable 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 anti-lock brake system is used. The function capable of warning the driver constitutes a second tire pressure drop warning function.

(Belt reinforcement layer)
Next, the belt reinforcing layer 16 according to the present invention will be described with reference to the drawings.

  4 is a view showing a cross section A in FIG. Originally, the belt layer 9 and the belt reinforcing layer 16 are continuously formed in the tire circumferential direction S, but in the same figure, in order to make each layer easy to see, each layer is divided at different positions. ing.

  As shown in the figure, the belt reinforcing layer 16 is disposed on the outer side in the tire radial direction of the belt layers 9a and 9b in which cords parallel to the tire equator line CL are inclined at a predetermined angle r and covered with rubber. Yes. Here, the predetermined angle r is preferably 90 ° or more or 90 ° or less.

  The belt reinforcing layer 16 is a layer in which a plurality of cords arranged in parallel at about 90 ° with respect to the tire equator line CL are covered with rubber. Specifically, the angle R at which the tire equator line CL and the cord intersect is about 90 °. Here, about 90 ° is 85 to 95 °, and ± 5 ° is an error in manufacturing.

  The width B of the belt reinforcing layer 16 is preferably 50% or more of the maximum width C of the belt layer 9. Since the width B of the belt reinforcing layer 16 is 50% or more of the largest maximum width C among the widths of the belt layer 9, that is, it has a relatively large width with respect to the belt layer 9, It is possible to suppress the tread portion 10 from being bent in a wide range.

  In the figure, the belt layer 9a is longer in the tire width direction W than the belt layer 9b, but is not limited to this, and the belt layer 9b is longer than the belt layer 9a in the tire width direction. The length in W may be long, and the length in the tire width direction W of the belt layer 9a and the belt layer 9b may be the same.

(Modification 1)
Hereinafter, Modification Example 1 of the tire particle assembly 100 according to the present embodiment will be described with reference to FIG. Note that FIG. 5 is a modification of FIG. 1, so only the parts different from FIG. 1 will be described here.

  As shown in the figure, the belt reinforcing layer 16 is disposed on the inner side in the tire radial direction of the belt layer 9. Since the belt reinforcing layer 16 is disposed on the inner side in the tire radial direction of the belt layer 9, the belt reinforcing layer 16 is used in a tensile region when the tread portion 10 is bent, so that deformation can be effectively suppressed.

(Modification 2)
Hereinafter, Modification Example 2 of the tire particle assembly 100 according to the present embodiment will be described with reference to FIG.

  As shown in the figure, the belt reinforcing layer 16 is disposed on the inner side in the tire radial direction of the carcass layer 6. Since the belt reinforcing layer 16 is disposed on the inner side in the tire radial direction of the carcass layer 6, the belt reinforcing layer 16 can be used more effectively in a tensile region when the tread portion 10 is bent, so that deformation can be suppressed.

(Modification 3)
Hereinafter, Modification Example 3 of the tire particle assembly 100 according to the present embodiment will be described with reference to FIG.

  As shown in the figure, the belt reinforcing layer 16 is disposed between the two carcass layers 6. Since the belt reinforcing layer 16 is disposed between the two carcass layers 6, the belt reinforcing layer 16 is used in a tensile region when the tread portion 10 including the carcass layer 6 is bent. It is possible to suppress deformation.

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

  The hollow particle 4 has closed cells surrounded by a continuous phase of a substantially spherical resin, for example, a hollow body having a particle size distribution in the range of about 10 μm to 500 μm, or a large number of small chambers by closed cells. Is a spongy structure.

  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 pneumatic tire 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 due to the load. However, it may be difficult to block the damaged part with the hollow particles 4.

  Therefore, in this embodiment, when the gas in the tire chamber 3 leaks due to an injury, the sidewall portion 7 is prevented from being grounded, and the minimum internal pressure of the tire chamber 3 necessary for the subsequent traveling is reduced. The main objective is to give it properly and restore the lost internal pressure. 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, after temporarily sealing the damaged portion of the tire chamber 3 damaged by puncture with the hollow particle group filled in the tire chamber 3 before the tire is grounded by the sidewall portion 7, This purpose is achieved by restoring the pressure lost by making the hollow particles 4 function.

  Even if the internal pressure of the tire chamber 3 is reduced to the atmospheric pressure, by arranging the belt layer 9 on the inner side in the tire radial direction or on the outer side in the tire radial direction, the tread portion 10 is prevented from being bent. It is important to function as a pressure vessel by preventing the sidewall 7 from being grounded and exhibiting a function of restoring the internal pressure lost early (an internal pressure restoration 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 the atmospheric pressure described above, the “particles filled inside the tire 1” 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.

  The internal pressure in the hollow portion of the hollow particle 4 approaches the internal pressure of the tire chamber 3 (the void 11 around the hollow particle 4), and the particle volume once reduced is restored, and the particle shape is flattened and distorted. The shape will be restored to the original spherical shape. In the process of reviving this shape, the internal pressure in the hollow part 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 is changed from a flattened state to a substantially spherical shape. Thus, the durability of the hollow particles 4 described above can be ensured.

  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 portion 4 is restored while the volume of the hollow particles 4 is restored in a desired high-pressure environment such as the specified internal pressure of the vehicle in which the tire chamber 3 is 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% or more 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-specified internal pressure to be mounted. For example, the pressure may be maintained in a state where the pressure is increased to 70% or more with respect to the desired internal pressure of the tire chamber 3, and an appropriate time may be allowed to elapse while the pressure is continuously applied. 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 the present 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 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 the substantially spherical shape can be maintained if the hollow portion pressure is 70% or more, good fluidity and elasticity can be expressed by maintaining the substantially spherical shape, so that the internal pressure of the hollow portion 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 (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, the hollow particles 4 are re-expanded (expanded) by reaching the re-expansion start temperature “Ts2” when the internal pressure of the tire chamber 3 is reduced (so-called tire is damaged). In the present embodiment, the re-expansion start temperature “Ts2” indicates a predetermined temperature.

  In order to restore the internal pressure of the tire chamber 3, the hollow air particles 4 whose hollow portion internal pressure is at least 70% of the used internal pressure are filled into the tire chamber under 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, when the filling rate of the hollow particles exceeds 80 vol%, some tires expand due to heat generation due to particle friction during high-speed running during normal use, resulting in expansion exceeding 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 regular running.

  Further, in order to reliably develop the internal pressure recovery function, it is important to securely seal the damaged portion before the internal pressure recovery function is expressed. 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 void gas around the hollow particle starts to leak from the damaged portion where the tire 1 has been damaged, the flow due to the leakage of the void gas Get on the wound and immediately gather in the wound area, instantly seal the wound of the wound area. Thus, the sealing function of the damaged part by the hollow particles 4 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 minute, it is generated even under normal running. 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 within 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, the tire 1 has a certain amount of bending caused by bearing a load, and the area that is in contact with the road surface is in a state parallel to the road surface. Therefore, the contact area does not have a curvature. The centrifugal force becomes 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-grounding region 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.

  If the filling rate of the hollow particles 4 exceeds 80 vol%, depending on the tire, due to heat generation due to particle friction at high speed during normal use, the hollow particles 4 expand beyond the reexpansion start temperature (Ts2), 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 a hollow particle, a preferable range is the range of 40-200 micrometers. When the average particle size of the hollow particles is less than 40 μm, the above-mentioned true specific gravity distribution spreads, and the heat resistance is deteriorated due to 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 generated by the motion. Therefore, it is not preferable. On the other hand, when the average particle size of the hollow particles exceeds 200 μm, the situation where the particles collide with each other under normal running or when the internal pressure of the tire chamber 3 becomes atmospheric pressure due to puncture (scratching). In the situation where the hollow particle group directly supports the load in the so-called puncture state, the particles are selectively broken from the particles on the large particle size side, and there is a disadvantage that the desired running performance after being damaged cannot be obtained. This is not preferable because of fear.

  Furthermore, 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 smaller 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 regular 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 regular running is achieved.

Next, 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, an alicyclic hydrocarbon having 2 to 8 carbon atoms, and The fluorinated product 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.

  Although it does not specifically limit as this thermally decomposable foaming agent, Dinitroso pentamethylenetetramine, azodicarbonamide, para-toluene sulfonyl hydrazine and its derivative (s), and oxybisbenzene sulfonyl hydrazine can be mentioned suitably.

  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.

  As a result, the above-described “expandable resin particles” encapsulated in the resin continuous phase can be obtained using the gas component shown above as a liquid foaming agent, and the desired hollow particles 4 can be obtained by heating and expanding the particles. Can be obtained.

  In addition, 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. Obtainable.

  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 13. 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.

(Operation / Effect of Tire Particle Aggregation According to this Embodiment)
According to the tire particle assembly 100 of the present invention, the hollow particles 4 expand when reaching the predetermined temperature (Ts2) when the internal pressure of the tire chamber 3 decreases. Function can be demonstrated.

  Further, since the hollow particles 4 have a substantially spherical shape, it is possible to prevent the hollow particles 4 from hitting the wall surface of the tire chamber and the like due to the centrifugal force during running and being damaged. As a result, the hollow particles 4 can reliably exhibit the function of restoring the internal pressure after being damaged.

  Further, at least one belt reinforcing layer 16 in which a plurality of cords arranged in parallel at about 90 ° with respect to the tire equator line are covered with rubber is disposed on the inner side in the tire radial direction or the outer side in the tire radial direction of the belt layer 9. Therefore, when the tire is punctured, it is possible to suppress the tread portion 10 from being bent, thereby preventing the sidewall portion 7 from being grounded. Here, since the plurality of cords are juxtaposed at about 90 ° with respect to the tire equator line, the force for suppressing the tread portion 10 bent in the tire radial direction is the largest.

  Further, since the width B of the belt reinforcing layer 16 is 50% or more of the largest maximum width C among the widths of the belt layer 9, that is, the belt layer 9 has a relatively large width, the tread portion In the wider range in 10, it can suppress that the tread part 10 bends.

  Thus, since the side wall part 7 is restrained from being grounded, damage to the side wall part 7 can be prevented, and the hollow particles 4 can reliably exhibit the function of restoring the internal pressure.

  Examples of the tire particle aggregate according to the embodiment of the present invention will be described in detail below.

  A tire particle in which a belt reinforcing layer in which a plurality of cords arranged in parallel at about 90 ° with respect to the tire equator line of the present invention are covered with rubber is arranged on the outer side in the tire radial direction of the belt layer 9 as shown in FIG. An assembly (Example 1) was manufactured, and the occurrence state of a tread buckling in which the tread portion was bent and the ground contact state of the sidewall portion were examined during puncture. Further, as a comparison, a tire particle assembly (Comparative Example 1) having a belt reinforcing layer in which a plurality of cords parallel to each other at 0 ° with respect to the tire equator line are covered with rubber, and at 20 ° with respect to the tire equator line. Tire particle assembly (Comparative Example 2) having a belt reinforcing layer in which a plurality of cords covered with rubber and a belt reinforcing layer in which a plurality of cords arranged parallel to the tire equator line at 45 ° are covered with rubber A particle aggregate (Comparative Example 3) and a tire particle aggregate (Comparative Example 4) having a belt reinforcing layer in which a plurality of cords arranged parallel to the tire equator line at 70 ° are covered with rubber are manufactured under the same conditions. Investigated under.

  The tire size used was 215 / 45R17.

<Tread buckling occurrence>
The tire particle aggregates of Example 1 and Comparative Examples 1 to 4 were mounted on a vehicle and punctured, and the occurrence of tread buckling after the running-in (10 km) was evaluated. Moreover, (circle) * in evaluation has shown the following.

○… Small tread buckling △… During tread buckling ×… Large tread buckling <Side contact on the side wall>
When the tire particle aggregates of Example 1 and Comparative Examples 1 to 4 are mounted on a vehicle, punctured, and the presence or absence of ground contact of the sidewall portion after the finish running (10 km), the sidewall portion is grounded In the state of damage in Moreover, (circle) * in evaluation has shown the following.

  ○: Almost no contact with the road surface.

  Δ: Scraping occurs due to contact with the road surface.

X: Wear occurs when in contact with the road surface.

  From the results in Table 1, it was found that Comparative Example 1 to Comparative Example 3 had a large tread buckling, and wear was caused by contacting the road surface even in the sidewall portion.

  Moreover, compared with the comparative example 1 thru | or the comparative example 3, compared with the comparative example 1 thru | or the comparative example 3, although a tread buckling became small, it turned out that a rubbing generate | occur | produces because a sidewall part contact | connects a road surface.

  Compared with Comparative Examples 1 to 4, Example 1 has the smallest tread buckling and the side wall portion hardly contacts the road surface.

  As a result, the belt reinforcement layer, in which a plurality of cords arranged in parallel at about 90 ° with respect to the tire equator line are covered with rubber, is arranged on the inner side in the tire radial direction or the outer side in the tire radial direction of the belt layer. In this case, since the tread portion is prevented from being bent, the sidewall portion can be prevented from being grounded, and it has been found that stable running can be obtained even after puncture.

It is a tire 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 for tire 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 figure which shows the belt layer and belt reinforcement layer which concern on embodiment of this invention. It is a tire width direction sectional view showing example 1 of change of a tire particle aggregate concerning an embodiment of the present invention. It is tire width direction sectional drawing which shows the modification 2 of the tire particle aggregate which concerns on embodiment of this invention. It is a tire width direction sectional view showing modification 3 of the tire particle aggregate concerning the 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 ... Carcass 7 ... Side wall part 8 ... Inner liner 9 ... Belt layer 9a ... Belt layer 9b ... Belt layer DESCRIPTION OF SYMBOLS 10 ... Tread part 11 ... Space | gap 12 around hollow particle ... Valve 13 ... Filter 14 ... Tire pressure sensor 15 ... Vehicle speed sensor 16 ... Belt reinforcement layer 50 ... Vehicle 50a ... Reception part 50b ... Alarm part

Claims (13)

A tire particle assembly that is an assembly of a tire having a belt layer and a plurality of hollow particles filled with a high-pressure gas exceeding atmospheric pressure into a tire air chamber partitioned by the tire and the rim,
In the tire, at least one belt reinforcing layer in which a plurality of cords arranged in parallel with each other at about 90 ° with respect to the tire equator line is covered with rubber is disposed on the inner side in the tire radial direction or the outer side in the tire radial direction of the belt layer
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 width of the belt reinforcing layer is 50% or more of the maximum width of the belt layer. 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. Using the following general formula (II)
Tire chamber volume value = (filled air discharge) / (internal pressure / atmospheric pressure) (II)
The tire particle aggregate according to claim 1 or 2, which is a value (cm ³ ) obtained from   The tire particle assembly according to any one of claims 1 to 3, 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 4, 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,
6. The average true specific gravity of the hollow particle group filled in the tire air chamber is 0.01 to 0.06 (g / cm ³ ). 6. 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 by fluorine atoms) The tire particle assembly according to any one of claims 1 to 6, wherein the tire particle assembly 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 8, wherein the tire particle aggregate is at least one of an original copolymer and an acrylonitrile / methacrylonitrile / methacrylic acid terpolymer.   10. A first tire pressure drop warning function for warning a drop 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.   11. 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 11. The foam has a substantially spherical shape with a diameter of 1 to 15 mm or a cubic shape with a 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. It has a bubble, The tire particle aggregate of Claim 12 characterized by the above-mentioned.

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