JP2003306005A - Tire and rim assembly body, and foaming composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire and a rim assembly body enabling stable traveling over the required distance even when an internal pressure of the tire is reduced after the tire is damaged without sacrificing rolling resistance and riding comfortableness in ordinary traveling before the tire is damaged. <P>SOLUTION: The tire is mounted on an application rim. Many particles composed of continuous phases of resin and independent air bubbles and having a substantially spherical shape are arranged in the inside of the tire partitioned by the tire and the application rim under the predetermined filling volume. A ratio of an average film thickness with respect to an average particle diameter of the particle is set 0.006 or less. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an assembly of a tire and a rim that enables normal running even after being damaged by an injury, and in particular, has excellent durability and riding comfort in running after damage to the tire, and The present invention relates to a tire-rim assembly having improved safety.

[0002]

2. Description of the Related Art In a pneumatic tire, for example, a passenger car tire, air is trapped inside the tire under a gauge pressure of about 150 kPa to 250 kPa to generate tension in a tire skeleton such as a carcass and a belt. This tension enables the tire to be deformed and restored in response to the input to the tire. That is,
By keeping the internal pressure of the tire within a predetermined range,
By generating a certain amount of tension in the skeleton of the tire to give it a load supporting function and increasing its rigidity, it gives the basic performance required for vehicle running, such as driving, braking and turning performance.

When the tire held at the predetermined internal pressure is damaged, air leaks to the outside through the damage and the internal pressure of the tire is reduced to atmospheric pressure. Most of the tension generated in the part is lost. Then, as a result of losing the load supporting function, driving, braking and turning performance obtained by applying a predetermined internal pressure to the tire,
A vehicle equipped with the tires becomes unable to run.

Therefore, many proposals have been made for so-called safety tires that allow the vehicle to run even in a punctured state. For example, as pneumatic safety tires and rim assemblies for automobiles, there are various types such as those having a double wall structure, those in which a load supporting device is provided in the tire, and those in which tire side portions are reinforced. Proposed.
Among these proposals, the technique actually used is a tire having a side reinforcing layer made of relatively hard rubber on the inner surface from the shoulder portion to the bead portion centering on the sidewall portion of the tire. This type of tire is mainly used as a so-called run-flat tire having a flatness ratio of 60% or less.

However, the method of adding the side reinforcing layer is as follows.
Since the tire weight is increased by 30% to 40% to increase the vertical spring constant of the tire, there are disadvantages that the rolling resistance is significantly deteriorated and the riding comfort during normal running before puncture is deteriorated. Therefore, it is a technology that is still lacking in versatility because it adversely affects the performance, fuel efficiency, and environment during normal driving.

On the other hand, in a pneumatic tire having a high tire cross-section height and an aspect ratio of 60% or more, in order to avoid heat generation in the sidewall portion due to traveling at a relatively high speed and a long distance, a core or the like is attached to the rim. Run-flat tires having a structure in which the internal support of is fixed to support the load at the time of puncture are mainly applied.

However, the tire cannot withstand the local repetitive stress generated between the tire and the internal support during the run-flat after puncture, and as a result, the mileage after puncture is about 100 km to 200 km. Was limited to. In addition, the work of assembling the tire on the rim after disposing the inner support inside the tire is complicated and requires a long time, which is also a problem. In this regard, there has been proposed a device for facilitating the insertion of the internal support by providing a difference in the rim diameter between the one end side and the other end side in the width direction of the rim, but the sufficient effect has not been obtained.

In order to extend the mileage after puncture of a run flat tire having an internal support, it is effective to add a frame material to make the tire structure heavier.
The addition of the skeletal material deteriorates rolling resistance and riding comfort during normal use, so it is not practical to adopt this method.

Further, these safety tires of the prior art can exhibit running ability after puncture to some extent on a normal asphalt road surface or a road surface having a relatively high friction coefficient such as an uneven road surface. However, on a road surface having a low coefficient of friction, which is represented by an icy road or a snowy road in winter, if the punctured tire is not the drive wheel but the idle wheel, a serious drawback is revealed. That is, in the state before puncture, of course, the tire deflection is small and the shape close to a circle is maintained,
When the vehicle starts to move due to the driving force generated from the driving wheels at the time of starting, the idle wheel starts rolling along with the movement of the vehicle.
However, in the state after the puncture, the tire is largely bent, and the shape deviates from the circular shape. Since the idle wheel is a wheel that cannot roll itself, that is, cannot generate a driving force, the rolling of the idle wheel depends on the movement of the vehicle and the friction coefficient of the road surface. Therefore, on a road surface with a low coefficient of friction, even if the vehicle starts to move, the tire that has deflected significantly due to puncture and deviates from the circular shape due to the low coefficient of friction on the road surface will cause a large slip in the ground contact tread and roll. Without being dragged, it will move with the vehicle.
The reason is that the ground contact pressure distribution in the ground contact tread becomes extremely non-uniform along with a large bending deformation as compared with the relatively uniform state before puncture. Such a situation occurs not only at the time of starting but also at the time of braking. Therefore, a "driving force adjustment function (traction control system)" that is a function that is installed in the vehicle in advance to supplement safe driving on a road surface with a low friction coefficient, and "braking force adjustment" that avoids tire lock during braking Not only is the function (anti-lock braking system) not fully exerted, but there is also the risk of malfunction and loss of control of the vehicle. In particular, in a vehicle in which the front wheels are idle wheels and steered wheels, and the rear wheels are drive wheels, it goes without saying that if the front wheels are punctured, the steerability will be extremely reduced and a very dangerous state will result.

Further, a tire in which a foam having closed cells is filled in an inner cavity of an assembly of a tire and a rim to be assembled to the tire is disclosed, for example, in Japanese Patent Laid-Open Nos. 6-127207 and 6-183226. It is described in, for example, Kaihei 7-186610 and JP-A-8-332805. The tires proposed therein are mainly limited to special or small tires such as agricultural tires, rally tires, motorcycle tires and bicycle tires. Therefore, its application to tires for passenger cars and tires for trucks and buses, such as tires that emphasize rolling resistance and riding comfort, has been unknown. And since any foam has a low expansion ratio, it has a large weight in place of the foam having bubbles, and it is inevitable that vibration riding comfort and fuel consumption are deteriorated, and since the inside of the closed cells is at atmospheric pressure,
It was not functionally sufficient as a substitute for the high pressure air of conventional tires.

Further, Japanese Patent No. 2987076 discloses a puncture tire in which a foam filler is inserted in the inner peripheral portion. However, in addition to the disadvantage that the internal pressure of bubbles is extremely close to the atmospheric pressure, Since it is a urethane type, energy loss due to intermolecular hydrogen bond of urethane group is large and self-heating property is high. Therefore, when the urethane foam is filled in the tire, repeated deformation during rolling of the tire causes the foam to generate heat, resulting in a significant decrease in durability. In addition, since it is difficult to form air bubbles independently of each other, it is difficult for air bubbles to communicate with each other and it is difficult to retain gas, and the desired tire internal pressure (load supporting ability or deflection suppressing ability, the same applies below) is obtained. There are disadvantages that cannot be obtained.

Further, in Japanese Unexamined Patent Publication (Kokai) No. 48-47002, the outer circumference of a multi-cell body mainly composed of closed cells is integrally covered with an outer coating film such as rubber or synthetic resin having a thickness of 0.5 to 3 mm. A puncture-less tire has been proposed in which a large number of expanded pressure bubbles that have been sealed are filled in a tire and the tire is maintained at a specified internal pressure. In this technique, in order to make the bubble internal pressure of the foam higher than normal pressure, the amount of the foaming agent compounded in the closed foam forming compound material that becomes the expansion pressure bubble is at least equal to or more than the tire internal volume. The amount of foaming agent that generates gas is set so that at least the same performance as ordinary pneumatic tires is aimed at.

In the above-mentioned technique, in order to prevent the gas in the bubbles in the expanded pressure bubble from being dissipated, the outer envelope film is integrally encapsulated and sealed. The material of the outer envelope film is exemplified by an automobile. Materials such as tubes for use or formulations for forming the tubes. In other words, a soft elastic envelope film mainly composed of butyl rubber having a low nitrogen gas permeability, which is used for a tire tube or the like, is used for covering and sealing, and many of these are filled in the tire. As a manufacturing method, an unvulcanized tire tube was used as a soft elastic envelope film, and an unvulcanized closed-cell body-forming compounding raw material was used as an expanding pressure bubble body, and many of these were placed inside a tire-rim assembly. The foam-filled tire is obtained by foaming by heating. The atmospheric air inside the tire due to the expansion of the foam is naturally exhausted from the exhaust small holes formed in the rim.

Since the internal pressure of a passenger car tire is generally set to about 150 to 250 kPa at room temperature, the above foam-filled tire is manufactured by heating during vulcanization molding (140 ° C.). It is estimated from the equation of state of gas that the absolute pressure is about 1.5 times the internal pressure. However, at such a pressure level, it is unavoidable that the vulcanization pressure is insufficient and blown out. In order to avoid this blown phenomenon, it is necessary to greatly increase the compounding amount of the foaming agent to increase the pressure generated by foaming and increase the heating temperature. However, the method of increasing the amount of the foaming agent blended has been difficult to substitute for the conventional pneumatic tire because the internal pressure at room temperature greatly exceeds 300 kPa due to the increase of the blending amount of the foaming agent. In addition, the method of increasing the heating temperature causes a great damage to the tire due to heat aging and significantly deteriorates the durability of the tire, which causes a problem in the durability in long-term use. On the other hand, inside the tire and rim assembly, a large number of expansion pressure bubbles wrapped in a soft elastic envelope film are arranged. However, friction between the soft elastic envelope films caused by the blow, inner tire surface and rim inner surface There is a big problem in terms of durability such as friction with. From the above, it can be said that the above-mentioned problem is a large defect caused by disposing a large number of divided expanded pressure bubbles, unlike the case where the expanded pressure bubbles have an integral donut shape.
Further, although the exhaust small hole formed in the rim is effective for naturally exhausting the normal pressure air inside the tire due to the expansion of the inflation pressure bubble, it does not function as a dissipation path for the gas in the bubble in the inflation pressure bubble. Therefore, it cannot withstand long-term use.

Further, as the soft elastic envelope film, a compounded composition mainly composed of butyl rubber having a small nitrogen gas permeability such as a tire tube is used. However, since butyl rubber has an extremely slow vulcanization reaction rate, A large heating time is required at a temperature of about 140 ° C. to complete the reaction. This means that the cross-linking density of the soft elastic envelope coating is insufficient, and it goes without saying that it becomes a factor in the occurrence of peeling of the soft elastic envelope coating. Further, the extension of the heating time further increases the damage of the tire due to the above-mentioned heat aging, so that the deterioration of the durability cannot be avoided and is not a good measure.

[0016]

Therefore, the present invention is
An assembly of a tire and a rim that can stably travel a required distance even when the tire internal pressure decreases after the tire is damaged without sacrificing rolling resistance and riding comfort during normal driving. The purpose is to provide.

Another object of the present invention is to provide a guarantee that the above-mentioned performance after the tire is damaged can be surely exhibited over the period of use from the time of new tire to the end of life due to wear or the like. It is to provide a foamable resin composition which is a raw material of particles to be arranged inside an assembly of a rim and a rim.

[0018]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the inventors have found that in order to enable stable running even when the tire internal pressure decreases after injury.
It has been found that it is effective to apply the minimum tire pressure necessary for the subsequent running by an appropriate means when gas in the tire leaks due to external damage.

That is, the gist of the present invention is as follows. (1) A tire is mounted on an applicable rim, and a large number of substantially spherical particles made of a resin continuous phase and closed cells are provided in the tire partitioned by the tire and the applicable rim, and the following upper limit value and An assembly of a tire and a rim, which is arranged under a filling volume amount according to a lower limit value and has a ratio of an average film thickness to an average particle diameter of the particles of 0.006 or less. The upper limit of the filling volume: A tire and rim assembly adjusted to the internal pressure specified by the vehicle on which the tire and rim assembly is mounted is mounted on the vehicle, and the load applied to each axle of the vehicle is Inner volume of the assembly when loaded. Lower limit of filling volume: A tire-rim assembly having an internal pressure set to atmospheric pressure is mounted on the vehicle, and a load of 2.0 times the load applied to each axle of the vehicle at the upper limit is applied to the tire and the rim. Inner volume of the assembly when and is loaded. However, the filling volume of particles refers to the total volume of all particles filled inside the tire-rim assembly under atmospheric pressure, and includes the void volume around the particles.

(2) A tire-rim assembly according to the above (1), wherein the ratio of the average film thickness to the average particle size of the particles is 0.005 or less.

(3) The tire-rim assembly according to the above (1), wherein the ratio of the average film thickness to the average particle size of the particles is 0.004 or less.

(4) In any one of (1) to (3) above, the total volume of particles arranged inside the tire under the internal pressure specified by the vehicle is the total volume of the particles under atmospheric pressure. 80% or more of the tire and rim assembly.

(5) In any one of (1) to (4) above, the continuous phase of particles is at least one of polyvinyl alcohol resin, acrylonitrile polymer, acrylic polymer and vinylidene chloride polymer. A tire-rim assembly comprising:

(6) In any one of (1) to (5) above, the continuous phase of the particles comprises an acrylonitrile polymer, and the acrylonitrile polymer is an acrylonitrile polymer, an acrylonitrile / methacrylonitrile copolymer, An assembly of a tire and a rim, which is at least one selected from an acrylonitrile / methyl methacrylate copolymer and an acrylonitrile / methacrylonitrile / methyl methacrylate terpolymer.

(7) In any one of (1) to (5) above, the continuous phase of the particles is made of an acrylic polymer,
The acrylic polymer is at least one selected from a methyl methacrylate resin, a methyl methacrylate / acrylonitrile copolymer, a methyl methacrylate / methacrylonitrile copolymer and a methyl methacrylate / acrylonitrile / methacrylonitrile terpolymer. An assembly of a tire and a rim.

(8) In any one of the above (1) to (5), the continuous phase of the particles comprises a vinylidene chloride polymer, and the vinylidene chloride polymer is vinylidene chloride /
Acrylonitrile copolymer, vinylidene chloride / methylmethacrylate copolymer, vinylidene chloride / methacrylonitrile copolymer, vinylidene chloride / acrylonitrile / methacrylonitrile copolymer, vinylidene chloride / acrylonitrile / methylmethacrylate copolymer, vinylidene chloride / methacrylonitrile / Methyl methacrylate copolymer and at least one selected from vinylidene chloride / acrylonitrile / methacrylonitrile / methyl methacrylate copolymer.

(9) In any one of the above (1) to (8), nitrogen, air, linear and branched aliphatic hydrocarbons having 2 to 8 carbon atoms and fluorinated compounds thereof are contained in the bubbles of the particles. An alicyclic hydrocarbon having 2 to 8 carbon atoms and a fluorinated compound thereof, and the following general formula (I): R ¹ —O—R ² ---- (I) (wherein R ¹ and R ² are , Each independently has 1 carbon
At least 1 selected from the group consisting of a monovalent hydrocarbon group of 5 to 5 and some of the hydrogen atoms of the hydrocarbon group may be replaced with fluorine atoms). A tire and rim assembly having a species of gas.

(10) In (9) above, an inner liner layer is provided on the inner peripheral surface of the tire, and the gas permeability coefficient at 30 ° C. of the inner liner layer is 20 × 10 ^-12 (cc).
-Cm / cm ² · s · cmHg) or less tire and rim assembly.

(11) In any one of the above (1) to (10), the tire internal pressure drop warning function based on the wheel speed detection by the wheel speed sensor of the antilock brake system and the method for directly measuring the tire internal pressure by the pressure sensor are further provided. A tire and rim assembly having one or both of the following tire pressure drop warning functions.

(12) A foamable composition containing the following resin (A) and one or both of the following thermally decomposable foaming agent (B) and the following foaming agent (C). (A) At least one kind selected from polyvinyl alcohol resin, acrylonitrile-based polymer, acrylic polymer and vinylidene chloride-based polymer (B) dinitrosopentamethylenetetramine, azodicarbonamide, paratoluenesulfonylhydrazine and derivatives thereof. And at least one (C) linear or branched aliphatic hydrocarbon having 2 to 8 carbon atoms selected from oxybisbenzenesulfonylhydrazine and its fluorinated product, and alicyclic hydrocarbon having 2 to 8 carbon atoms And a fluorinated compound thereof, and the following general formula (I): R ¹ —O—R ² ---- (I) (R ¹ and R ² in the formula each independently have 1 carbon atom.
To 5 monovalent hydrocarbon groups, in which a part of the hydrogen atoms of the hydrocarbon groups may be replaced by fluorine atoms), at least one selected from ether compounds

Here, the internal pressure described in the text refers to a gauge pressure (pressure shown in the gauge) unless otherwise specified. That is, the atmospheric pressure is represented by a gauge pressure of 0 [kPa], and there is a relation that the gauge pressure is 0 [kPa] = absolute pressure 100 [kPa].

[0032]

BEST MODE FOR CARRYING OUT THE INVENTION A tire-rim assembly according to the present invention will be described below with reference to FIG. 1, which shows a cross section in the width direction, when the inside thereof is filled with substantially spherical particles. That is, the tire-rim assembly shown in the figure has the tire 1 mounted on the application rim 2, and the tire 1 divided by the tire 1 and the application rim 2 is composed of a resin continuous phase and closed cells. , A large number of substantially spherical particles 3 are arranged. The structure of the tire 1 is not particularly limited as long as it is a tire for various automobiles, such as a tire for passenger cars, which is generally used. For example, the illustrated tire is a general automobile tire, and a crown portion of a carcass 5 extending in a toroidal shape between a pair of bead portions 4 is provided with
A belt 6 and a tread 7 are arranged in this order radially outward. In the figure, reference numeral 8 is an inner liner layer, and 9 is a void around the particle 3.

The particles 3 have a closed cell surrounded by a continuous phase made of a substantially spherical resin, for example, a hollow body having a diameter of about 10 μm to 500 μm, or a spongy structure including a large number of small chambers of closed cells. Is. That is, the particles 3 are particles that contain closed cells that are closed without communicating with the outside, and the number of the closed cells may be singular or plural. The fact that the particles have closed cells means that the particles have a resin shell that encloses the closed cells in a sealed state. The continuous phase of the above-mentioned resin refers to the continuous phase in terms of the component composition that constitutes the resin shell. The composition of the resin shell will be described later.

By arranging a large number of the particles 3 inside the tire under the filling volume amount according to the following upper and lower limits, the internal pressure of the tire is partially responsible and
The minimum internal pressure required when a tire is damaged is secured. The upper limit of the filling volume: A tire and rim assembly adjusted to the internal pressure specified by the vehicle on which the tire and rim assembly is mounted is mounted on the vehicle, and the load applied to each axle of the vehicle is Inner volume of the assembly when loaded. Lower limit of filling volume: A tire-rim assembly having an internal pressure set to atmospheric pressure is mounted on the vehicle, and a load of 2.0 times the load applied to each axle of the vehicle at the upper limit is applied to the tire and the rim. Inner volume of the assembly when and is loaded. Here, the particle filling volume refers to the total volume of all particles filled inside the tire / rim assembly under atmospheric pressure, and includes the void volume around the particles.

The total volume of all particles placed inside the tire-rim assembly under atmospheric pressure is calculated by the following method. First, the average bulk specific gravity of the particles at atmospheric pressure is determined. The method is calculated, for example, by measuring the weight of a known volume under atmospheric pressure. Here, the particles are weighed in a graduated cylinder under atmospheric pressure, and are oscillated in an ultrasonic water bath, and the total volume of the particles (including the void volume around the particles) is measured while the packing between the particles is stable. The average bulk specific gravity under the above atmospheric pressure was calculated by measuring the total weight of the particles. That is, the average bulk specific gravity of the particles under the atmospheric pressure is the average bulk specific gravity of the particles under the atmospheric pressure = (total weight of particles) / (total volume of particles).

Next, the total weight of the particles filled in the tire is measured and divided by the average bulk specific gravity of the particles calculated above under the atmospheric pressure to obtain the total weight of all the particles placed inside the tire under the atmospheric pressure. The total volume at can be calculated. That is, (total volume of all particles arranged inside the tire under atmospheric pressure) = (total weight of particles packed in the tire) / (average bulk specific gravity of particles under atmospheric pressure)

The internal volume of the tire-rim assembly is defined by the volume enclosed by the tire and rim. Therefore, after assembling the rim to the tire, an incompressible fluid such as water having a known specific gravity was filled into the rim, and the inner volume of the tire-rim assembly was determined from the weight increase.

In a tire-rim assembly in which a large number of the particles 3 are arranged inside the tire 1 under the above-mentioned volume filling rate, when the tire is damaged, the tire together with the particles 3 is tired. As a result of gas leaking to the outside of the tire existing in the voids 9 between the particles 3 that had given the internal pressure specified by the vehicle, the internal pressure of the tire-rim assembly is about the same as the outside of the tire. Fall to. Then, in the process of lowering the internal pressure, the following things occur in the tire.

First, when the tire is damaged and the internal pressure starts to drop, particles seal the damaged part and suppress a sudden decrease in internal pressure. On the other hand, the amount of bending of the tire increases with the decrease of the tire internal pressure, and the inner volume of the tire-rim assembly decreases, so that the inner volume of the tire-rim assembly reduces the total volume of the filled particles. Approaching. When the tire internal pressure is further reduced, the internal volume of the tire-rim assembly is reduced to a state approximately equal to the total volume of the filled particles. From this state, the particles themselves directly bear the load, and the minimum amount of tire bending necessary for the subsequent running is maintained. On the other hand, the bubble internal pressure in the closed bubbles of the particles that existed under the internal pressure specified by the vehicle (hereinafter, referred to as the vehicle specified internal pressure) maintained the same pressure as the vehicle specified internal pressure even after being damaged. In other words, in other words,
The particles exist in the assembly of the tire and the rim while maintaining the total particle volume before the damage. Therefore, as the tire further rolls, the particles themselves directly bear the load, while the particles cause friction and self-heat,
The temperature of the particles in the tire and rim assembly rises sharply.
Then, the thermal expansion start temperature of the resin that forms the continuous phase of the particles is exceeded, and in addition to the pressure inside the bubbles in the closed cells of the particles being the pressure according to the vehicle specified internal pressure, the pressure inside the bubbles is further increased due to the sudden increase in the particle temperature. Since the particle size is rising, the particles expand in volume at once and the internal pressure of the tire can be restored to a state close to that before the damage.

In the above-mentioned state, the particles directly bear the load to give the minimum tire internal pressure required for running. The tire deflection in this state is comparatively small, and it is possible to maintain a circular shape compared to the safety tire according to the prior art, and therefore it is possible to maintain a relatively uniform contact pressure distribution in the contact tread. In the tire and rim assembly of the present invention in which the above hollow particles are filled in a tire mainly used for road surface running in winter such as a studless tire, the studless tire has a basic structure even after the tire is damaged. Performance is not reduced. That is,
Even on a road surface with a low coefficient of friction such as ice and snow, driveability,
It does not deteriorate driving performance such as braking performance and turning performance, and it does not impede running.

The above effect can be obtained by arranging the particles inside the tire under a predetermined filling volume amount,
It is not necessary to regulate the tire structure itself, a general-purpose tire,
Then, a general-purpose rim can be utilized to newly provide a safety tire and a rim assembly.

Next, "the upper limit value of the volume of packed particles is adjusted to the internal pressure specified by the vehicle in which the tire / rim assembly is mounted, and the tire / rim assembly is mounted in the vehicle. The internal volume of the assembly when a load applied to each shaft of the vehicle is applied will be described. In the present invention, the tire internal pressure is restored by the expression mechanism described above. Therefore, if particles with a volume exceeding the above-mentioned upper limit value are filled, friction between particles may occur during traveling at a specified internal pressure before tire damage, and this friction may increase rolling resistance. . This is not preferable from the viewpoint of fuel economy.

In addition, "the lower limit of the filling volume is set to the vehicle with the tire-rim assembly whose internal pressure is set to the atmospheric pressure, and the load applied to each axle of the vehicle at the upper limit of 2.0 The reason why the double load is applied to the tire-rim assembly will be described. That is, in the present invention, the tire internal pressure is restored by the expression mechanism described above. Therefore, when the particles having a volume less than the above lower limit value are filled, the particles themselves cannot directly bear the load even if the tire internal pressure is reduced to the atmospheric pressure, and the friction between the particles is less likely to be caused. As a result, the recovery of tire internal pressure cannot be guaranteed.

As described above, by filling the particles under the filling volume amount according to the above upper limit value and the lower limit value, the function of recovering the internal pressure can be surely exhibited, and with this, a constant value after the tire is damaged. Driving safely over a distance is achieved. In addition, the upper limit of the filling volume of the particles,
It suffices to appropriately respond to each axial load of the vehicle depending on the running conditions of the vehicle, the usage method and conditions depending on the number of passengers, the load capacity of the luggage, and the like. That is, in the use situation in which the number of passengers and the load of cargo fluctuate day by day, it is preferable to lower the upper limit value of the particle volume in view of the above concern. That is, it is preferable that the inner volume of the tire / rim assembly is 1.2 times, more preferably 1.5 times, and further preferably 2.0 times the load applied to each axle of the vehicle.

Similarly, the lower limit of the filling volume of the particles can be described as a preferable range for the following reason. That is,
When the internal pressure starts to decrease due to tire damage, friction between particles immediately occurs and the internal pressure is restored when the filling volume is close to the upper limit value. In this situation, the difference in wheel speed between the left and right wheels is not large and the amount of pressure drop in the direct measurement with the tire internal pressure sensor is not large, so the sensitivity to detect internal pressure drop due to tire damage is reduced, and the danger information is appropriate to the driver. You may not be able to inform. On the other hand, when the filling volume is close to the lower limit, when the internal pressure decreases due to tire damage,
Due to a large decrease in internal pressure, the amount of bending increases and the internal volume of the tire also decreases, and friction between particles then occurs, which leads to the recovery of internal pressure. Under this circumstance, the tire internal pressure is once greatly reduced, so that the tension of the tire frame member such as the carcass is also greatly reduced. Therefore, there is a concern that the bead portion of the tire fitted to the rim may come off from the rim in a low internal pressure (= low tension) state until the internal pressure is restored for a very short time. Therefore, in order to avoid such a concern, it is preferable that the lower limit value is high. Specifically, the lower limit is
Under a load of 2.0 times the load applied to each axle of the vehicle, the internal volume when the tire internal pressure is atmospheric pressure, preferably the internal volume when the tire internal pressure is 10% of the designated internal pressure,
The inner volume is further preferably 30%, more preferably 40%, and most preferably 50%.

In the present invention, the particles are arranged inside the tire under a predetermined filling volume, and then a gas such as air or nitrogen is filled so that the pressure in the voids around the particles becomes the vehicle-specified internal pressure. It is essential. That is, when gas is filled and the pressure in the void is set to the vehicle-specified internal pressure, the volume of the particle decreases because the internal pressure of the particle is smaller than the pressure in the void. The shape of the particles at this point is not a substantially spherical shape, but a distorted shape that is flattened from a spherical shape. When traveling is started with the particle shape flattened and distorted, the particles are more likely to be broken due to collision of particles with each other or collision with the inner surface of the tire and the rim, as compared with the case of spherical shape. That is, in the flattened and distorted shape, the input due to the collision cannot be uniformly dispersed, which brings about a great disadvantage in terms of durability.

On the other hand, the flattened and distorted particles decrease in volume due to the difference between the internal pressure of the particles and the pressure in the voids, and then the pressure in the voids around the particles is maintained for a certain period of time, in other words For example, the internal pressure of the closed cells in the particles can be increased to the pressure of the voids. That is, since the flattened particles have been deformed, the force of returning to the original substantially spherical shape acts on the shell portion of the particles. Further, since the gas pressure in the flattened particles is lower than the pressure of the void gas, the gas in the voids penetrates into the particles in order to eliminate the pressure difference. Furthermore, the gas in the closed cells in the particles may be different from the gas in the void portion because it is a gas caused by the foaming agent, and in this case,
The permeation of the gas in the voids into the particles follows not only the above-mentioned mere pressure difference but also the partial pressure difference of the gas, and the gas permeates in the direction of eliminating the partial pressure difference. In this way, the bubble pressure of the closed bubbles in the particles approaches the void pressure around the particles and recovers the reduced particle volume once, and the particle shape changes from the flattened distorted shape to the original substantially spherical shape. Return to. According to the above mechanism and the shape of the particles, the process of changing the volume, by appropriately adjusting the type and pressure of the gas filling the voids inside the tire, the bubble pressure of the closed bubbles in the particles within a predetermined range. Can be set.

By setting the bubble internal pressure of the closed bubbles in the particles to a high pressure equal to or higher than the atmospheric pressure by the above method, the above-mentioned internal pressure restoring function after the tire is damaged can be surely exhibited. In addition, since high-pressure gas is passed around the particles, the load that the particles bear during normal traveling can be reduced to a negligible level, and in the particles that have recovered the particle volume described above, the particle shape is substantially spherical. Therefore, fatigue and breakage applied to the particles due to repeated deformation during rolling of the tire can be significantly reduced, and the durability of the particles is not impaired. The range in which the durability of the particles is not impaired is at least 70% of the volume of the particles based on the particle volume at atmospheric pressure in the process of recovering the volume in a high-pressure environment such as a desired vehicle-specified internal pressure. It is recommended to recover the volume up to 80%, preferably 80% or more, more preferably 90% or more.

Here, in order to make the particle volume under the vehicle specified internal pressure 70% or more of the particle volume at atmospheric pressure, as described above, it is appropriate to keep the void pressure around the particles high. The particle volume can be recovered over time. Alternatively, the particles are filled in a pressure container different from the tire, and in a state in which the void pressure is set to be high, the particles are stored in the pressure container for an appropriate time, and the particles in the state where the volume is restored are By filling the tire together with the atmosphere, the particle volume can be adjusted to a desired ratio.

In order to maintain the particle volume without destroying the particles whose volume has been recovered under normal use, the ratio of the average film thickness to the average particle diameter of the particles is preferably 0.006 or less. Is 0.005 or less, more preferably 0.004 or less. That is, the particles that have recovered the particle volume under the high pressure environment described above,
Although it has recovered to a substantially spherical shape, when the ratio of the average film thickness to the average particle size of the particles exceeds 0.006, the rigidity of the particles increases because the film thickness of the particles is too thick with respect to the particle size. It becomes difficult to absorb the impact caused by the collision of the particles described above by the deformation of the particles themselves. Then, the impact of the collision is directly received by the particles, and the durability of the particles is significantly reduced. Therefore, it is necessary to regulate the ratio of the average film thickness to the average particle size of the particles to 0.006 or less.

Here, in order to control the ratio of the average film thickness to the average particle size of the particles to be 0.006 or less, in molding the particles described later, first, in the polymerization of the resin continuous phase forming the particles, the monomer and the gas are The desired particle size and film thickness can be obtained by changing the amount ratio with or by appropriately adjusting the heat-foaming conditions in the expandable resin particles in which the gas component is enclosed in the resin continuous phase, such as the heating temperature and the heating time. Can be obtained.

Further, in order to surely exhibit the above-mentioned internal pressure restoring function, it is essential to surely seal the damaged portion before the internal pressure restoring function is exhibited. In other words, if the damaged part is not completely sealed, the internal pressure that should have been restored will leak from the damaged part, and the internal pressure obtained by restoring the internal pressure can only temporarily contribute to the traveling performance thereafter. This is because there is a risk that the driving performance after injury may not be guaranteed. Since the particles are particles having a low specific gravity and a high elasticity due to the hollow structure, when the tire is damaged and the void gas around the particles begins to leak from the damaged portion, it immediately rides on the flow due to the leakage of the void gas. It closes up on the damaged area and instantly seals the wound area of the damaged area. As described above, the function of sealing the damaged portion with the particles is an essential function that supports the internal pressure restoring function of the present invention.

Here, in arranging the particles inside the tire according to the present invention, in order to enhance the sealing function of the damaged portion of the tire when the tire is damaged, a liquid which does not substantially swell the continuous layer of the particles. It is possible to extend the expression period of the internal pressure restoring function and increase the running ability after the tire is damaged by adding the.

That is, since the particles have a substantially spherical shape, they have a high fluidity, and therefore can be easily filled into the tire-rim assembly from the inlet having a small inner diameter such as a tire valve. On the other hand, when the tire is damaged, the particles gather on the inner surface of the damaged part in an attempt to blow out from the damaged part to the outside of the tire. However, since the damage route from the inner surface of the damaged portion to the outer peripheral surface of the tire has a complicated intricate shape rather than a straight line, the particles that have entered from the scratch on the inner surface of the tire block the way along the path, resulting in a large number of particles. As a result of gathering in a compressed state on the inner surface of the damaged part, the damaged part is provisionally sealed. Here, provisionally sealing means a state in which the particles themselves do not leak but the void gas around the particles gradually leaks.

At that time, when a liquid is added together with the particles inside the tire, the aggregate of the particles in the compressed state at the damaged portion is based on the affinity between the surface of the particles and the liquid and the viscosity of the liquid. The liquid flows into the gaps between the particles, and the damaged portion can be filled in an instant.

Further, since the liquid to be mixed has a large specific gravity as compared with particles, under normal running, a large amount of liquid is distributed on the inner surface of the tire tread portion due to the centrifugal force caused by rolling of the tire. This means that a large number of the particles, which are relatively large aggregates, are present near the inner surface of the tire tread portion during normal running. Therefore, when the tire is damaged by stepping on a foreign substance or the like, most of the particles that have become an aggregate through a relatively large amount of liquid quickly seal the damaged part, which is extremely effective.

In order to obtain the particle-filled tire in which a liquid is mixed, the following points should be noted in production. That is, when filling the tire, it is important that the particles are filled in a highly fluid state, in other words, in a dry state before being mixed with the liquid. The particles have a property of easily forming an aggregate when mixed with a liquid as described above. Therefore, the particles mixed with the liquid have extremely low fluidity, which makes it difficult to fill the tire. Therefore, the liquid to be mixed, a method of applying to the tire inner surface or rim inner surface before filling,
The method of injecting the liquid into the tire-rim assembly after filling the particles is efficient and reliable.

Specific examples of the liquid used in the present invention include silicone oil and aliphatic polyhydric alcohols represented by ethylene glycol and propylene glycol.

By the way, although the specific gravity of the particles is extremely small, not all of the particles are uniform, but the particles have a specific gravity distribution. As a measure for separating these particles into two components from the viewpoint of specific gravity, a component (specific gravity: 0.79) that precipitates in ethanol (specific gravity: 0.79) is used.
The above particles) and floating components (particles having a specific gravity of 0.79 or less) were tried to be separated, and each particle was positioned under the definition such as the content rate of the precipitated component with respect to the total weight of the sample. Here, the facts found from the definition of the precipitation component content rate are as follows.

That is, of the particles arranged inside the tire, the content of particles having a specific gravity of 0.79 or more is preferably 40 mass% or less. First, the content rate of particles having a specific gravity of 0.79 or more was defined because it was found that the component having a specific gravity of 0.79 or more controls the durability of the particles. Therefore, the content of particles having a specific gravity of 0.79 or more is 4
If it exceeds 0 mass%, when the air pressure around the particles becomes atmospheric due to tire damage, the particles will break down extremely rapidly, causing the tire to bend significantly, and the tire will run while dragging the side parts. There is a risk that the tire may be damaged before the target distance is reached due to local wear of the portion.

For the above reasons, it is recommended that the content of particles having a specific gravity of 0.79 or more be 40 mass% or less.
Furthermore, the content rate is 30 mass% or less, 20 mass% or less,
And it is more preferable to set it to 10 mass% or less.

Further, in order to apply the minimum required internal pressure by the particles in a low internal pressure state after the tire is damaged, the gas enclosed in the closed cells of the particles at a predetermined pressure should not leak out of the particles. In other words, it is essential that the continuous phase of closed cells in the particles has a property of making it difficult for gas to permeate. That is, the continuous phase of the particles forming the matrix of the closed cells is made of a material having low gas permeability, specifically, polyvinyl alcohol resin, acrylonitrile-based copolymer, acrylic copolymer, vinylidene chloride-based copolymer. , Acrylonitrile / styrene resin (AS), polyethylene resin (PE), polypropylene resin (P
P), polyester resin (PET) and polystyrene / polyethylene copolymer (PS / PE). All of these materials are particularly effective for the present invention because they can be foamed relatively easily in the tire and have flexibility for input due to tire deformation.

In particular, it is preferable to apply any one of polyvinyl alcohol resin, acrylonitrile polymer, acrylic polymer and vinylidene chloride polymer to the continuous phase of particles. Further, as the acrylonitrile-based polymer, acrylonitrile polymer, acrylonitrile / methacrylonitrile copolymer, acrylonitrile / methylmethacrylate copolymer and acrylonitrile / methacrylonitrile / methylmethacrylate 3
At least one selected from the original copolymers, as the acrylic polymer, methyl methacrylate resin (MMA),
Methyl methacrylate / acrylonitrile copolymer (M
MA / AN), methyl methacrylate / methacrylonitrile copolymer (MMA / MAN) and methyl methacrylate / acrylonitrile / methacrylonitrile 3
At least one selected from the former copolymers (MMA / AN / MAN), and as the vinylidene chloride-based polymer,
Vinylidene chloride / acrylonitrile copolymer, vinylidene chloride / methyl methacrylate copolymer, vinylidene chloride / methacrylonitrile copolymer, vinylidene chloride /
Acrylonitrile / methacrylonitrile copolymer, vinylidene chloride / acrylonitrile / methyl methacrylate copolymer, vinylidene chloride / methacrylonitrile /
At least one selected from the group consisting of methyl methacrylate copolymer, vinylidene chloride / acrylonitrile / methacrylonitrile / methyl methacrylate copolymer is preferably suitable. Since all of these materials have a low gas permeability coefficient and a low gas permeability, the gas in the closed cells does not leak to the outside and the air pressure in the closed cells can be maintained.

Further, the continuous phase of particles has a gas permeability coefficient of 300 × 10 ⁻¹² (cc · cm / cm ^{2) at} 30 ° C.
· S · cmHg) or less, preferably a gas permeability coefficient at 30 ° C. of 20 × 10 ⁻¹² (cc · cm / cm ² · s · c)
mHg) or less, more preferably a gas permeability coefficient at 30 ° C. of 2 × 10 ⁻¹² (cc · cm / cm ² · s · cmH)
It is recommended that g) or less. Because, the gas permeability coefficient of the inner liner layer in a normal pneumatic tire is 300 × 10 ⁻¹² (cc · cm / cm ² · s · cm).
Considering the track record of having a sufficient internal pressure holding function at a level of Hg) or less, the gas permeation coefficient at 30 ° C. of the continuous phase of particles is 300 × 10 ⁻¹² (cc · cm / cm 2).
cm ² · s · cmHg) or less. However, at this gas permeation coefficient level, it is necessary to replenish the internal pressure about once every 3 to 6 months, so from the viewpoint of maintainability,
20 x 10 ^-12 (Cc · cm / cm ² ・ S ・ cmHg)
^Or less, more preferably 2 × 10 ⁻¹² (cc · cm / c)
m ² · s · cmHg) or less is recommended.

As the gas forming the closed cells of the particles, nitrogen, air, linear and branched aliphatic hydrocarbons having 2 to 8 carbon atoms and fluorinated compounds thereof, and alicyclic rings having 2 to 8 carbon atoms are used. Formula hydrocarbon and its fluorinated compound, and the following general formula (I): R ¹ —O—R ² ---- (I) (R ¹ and R ² in the formula each independently have a carbon number of 1).
At least 1 selected from the group consisting of a monovalent hydrocarbon group of 5 to 5 and some of the hydrogen atoms of the hydrocarbon group may be replaced with fluorine atoms). Seed. The gas filled in the tire may be air, but when the gas in the particles is not a fluorinated product, a gas containing no oxygen, such as nitrogen or an inert gas, is preferable in terms of safety.

The method of forming particles having closed cells is not particularly limited, but it is preferable to use a foaming agent. Examples of the foaming agent include a thermally decomposable foaming agent that generates a gas by thermal decomposition, a high-pressure compressed gas and a liquefied gas. In particular, many of the heat-decomposable foaming agents are characterized by generating nitrogen, and the particles obtained by appropriately controlling the reaction of the expandable resin particles by these have nitrogen in the bubbles.

Further, during the above resin continuous phase polymerization for forming particles, propane, butane, pentane, hexane, heptane, octane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane and the like are liquefied under high pressure. Then, while dispersing in the reaction solvent, there is also a method of emulsion polymerization, by which propane, butane, pentane, hexane, heptane, octane, cyclopropane, cyclobutane, cyclopentane,
Cyclohexane, cycloheptane and cyclooctane gas components such as liquid can be obtained foamable resin particles that are contained in the resin continuous phase in the liquid state, filled in the tire with this, when the particles by heating, Propane, butane, pentane, hexane, heptane,
Octane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane and cyclooctane are included. The isomers of butane, pentane, hexane, heptane and octane include isobutane, isopentane, neopentane, 2-methylpentane, 2,2-dimethylbutane, methylhexanes, dimethylpentanes, trimethylbutane, methylheptanes. , Dimethylhexanes, trimethylpentanes and the like.

In the above polymerization, as described above,
The particle size and the film thickness of the particles can be controlled by appropriately adjusting the amount ratio of the monomer and the gas and the heating and foaming conditions of the liquefied gas.

Further, the target tire is obtained by heat-foaming a product obtained by coating the surface of the expandable resin particles with an anti-blocking agent, an antistatic agent, a surfactant, an oil agent, etc. in the tire. You can Further, the target tire can be obtained by preliminarily heat-foaming the expandable resin particles to form substantially spherical particles and filling the particles into the tire and rim assembly.

Although the effects of the present invention have been described above, the following methods can be mentioned as measures for further enhancing the effects of the present invention. That is, in addition to the expanded spherical particles, the expandable resin particles are partially added. As a result, the function of recovering the internal pressure according to the present invention after the tire is damaged can be further enhanced. However, the expandable resin particles have a large specific gravity as compared with the expanded particles, which causes an increase in the weight of the tire-rim assembly, and also causes a decrease in the durability of the expanded particles. That was mentioned above. Therefore, the content ratio of the expandable resin particles to the total weight of the filled particles is 40 mass% or less, and further the content ratio is 30 mass% or less, 20 mass% or less, and 10 mass % Or less is preferable.

The foamable composition used in the present invention preferably contains a foaming agent. The foaming is not particularly limited, but it is preferable to use a thermally decomposable foaming agent.
Preferable examples of the thermally decomposable foaming agent include dinitrosopentamethylenetetramine, azodicarbonamide, paratoluenesulfonylhydrazine and its derivatives, and oxybisbenzenesulfonylhydrazine.

On the other hand, a tire usually has an inner liner layer on its inner peripheral surface. The inner liner layer comprises a nylon resin having a melting point of 170 to 230 ° C. and a halogen of isobutylene paramethylstyrene copolymer. And a thermoplastic elastomer composition in which an elastomer component containing a compound is dynamically vulcanized to a gelation rate of 50 to 95%,
preferable. This is because, unlike the conventional inner liner layer mainly composed of butyl rubber, by using a nylon resin as the continuous phase, the gas permeability becomes extremely low, so that the function of the inner liner layer can be enhanced. On the other hand, the gelling rate of the elastomer component containing the halide of isobutylene paramethylstyrene copolymer is 50 to 95%.
By using the dynamically vulcanized thermoplastic elastomer composition, it is possible to obtain an inner liner layer having excellent flexibility, heat resistance and durability. The inner liner layer having the above characteristics can create an environment in which the gas in the closed bubbles of the particles can easily remain in the bubbles.

The gelation rate means that the pelletized mixture after biaxial kneading is subjected to Soxhlet extraction with acetone in a water bath for 8 hours, and the residue is further subjected to n-
It is a value calculated by the following formula by extracting the unvulcanized elastomer component with a solvent by Soxhlet extraction with hexane and measuring the weight of the acetone and n-hexane extract after solvent drying. Gelation rate (%) = [weight of total formulation − {(amount of acetone extracted + amount of n-hexane extracted) −amount of stearic acid}] / weight of total formulation × 100

[0074] Further, the inner liner layer, the gas permeability coefficient at 30 ° C. is ^{20 × 10 -1 2 (cc ·} cm / c
It is preferably m ² · s · cmHg) or less. This is because even if the gas in the bubbles leaks from the particles for some reason, the gas in the bubbles in the particles may leak to the outside of the tire if the gas permeability of the inner liner layer is sufficiently low. Is less, which is advantageous for maintaining the internal pressure of the tire. That is, the gas permeability of the inner liner layer is a factor that directly determines the pressure retention of the tire as a pressure vessel. Of course, it is fundamental that the gas permeability of the continuous phase forming the particles is low, and it is ideal that an inner liner layer having low gas permeability is used.

Since the above effects are obtained by arranging particles inside the tire, it is not necessary to regulate the tire structure itself, and a general-purpose tire and a general-purpose rim are utilized to newly add a safety tire and A rim assembly can be provided.

Furthermore, the tire-rim assembly of the present invention includes a tire internal pressure drop warning function based on a wheel speed detection by a wheel speed sensor of an antilock brake system and a tire based on a direct measurement method of a tire internal pressure by a pressure sensor. Either or both of the internal pressure drop alarm functions can be provided, and safety can be further enhanced.

[0077]

EXAMPLES Particles of various specifications shown in Table 1 were applied to a tire having the structure shown in FIG.
A passenger car safety tire and a rim assembly in which a 5 / 70R13 tire was incorporated into a rim of size 5J × 13 were prototyped. Here, the tire 1 complies with a general structure of the tire type and size. The types of compositions constituting the continuous phase of the particles in Table 1 are as shown in Table 2, and the resin particles enclosing the gas bubble component shown in Table 2 are heated to be foamed into particles. . The particles were heated to a temperature 10 ° C. or higher higher than the thermal expansion start temperature shown in Table 2 and held for 30 minutes to control the degree of expansion due to foaming, and the particle size and film thickness were adjusted appropriately.
For the particles thus obtained, the ratio of the film thickness to the average particle size was investigated by the measurement method described below, and the results are shown in Table 1. These particles were then loaded into the tire and rim assembly under the fill volumes shown in Table 1. Similarly, the rubber types of the inner liner layer are as shown in Table 3, respectively.

Next, the assembly of the passenger car tire and the rim was filled with nitrogen gas to adjust the internal pressure to 200 kPa.
Next, after investigating the particle volume recovery behavior in advance by the investigation method described later, calculate the leaving time corresponding to the target particle volume recovery rate, while maintaining the internal pressure at room temperature while recovering the particle volume. The test tires were prepared.

The test tire thus obtained was set to 1500
It was mounted on a cc class passenger car, and vibration and riding comfort under normal internal pressure were evaluated by a professional driver on a scale of 10 points. The evaluation result shows that the higher the score, the better.

Further, for each of the above tires, a load of 3.53 kN and a speed of 90 km / h and a distance of 50,000 k
Drum running was carried out for m and the history of running was added. After that, a 1500 CC class passenger car was set to a loading capacity equivalent to four passengers, and an evaluation tire was attached to the left front wheel, and the axle weight of the left front wheel of the vehicle was measured. The axle weight of the left front wheel was 3.92 kN. Next, diameter 5.0mm, length 5
Four 0 mm nails were pushed from the tread surface of the evaluation tire toward the inside of the tire, and after confirming that the internal pressure of the tire had dropped to atmospheric pressure, the tire was run on the circuit of the test course at a speed of 90 km / h. The temperature inside the and rim assembly and the void pressure around the particles were continuously measured to investigate the expression status of the internal pressure recovery function. An internal pressure sensor that monitors the internal pressure is installed on the inner surface of the rim of the tire and rim assembly to be evaluated, and the signal of the measured internal pressure data is transmitted by radio waves using a commonly used telemeter, and is transmitted inside the test vehicle. The change in internal pressure was measured while receiving with the installed receiver. The temperature was measured with a temperature sensor on the inner surface of the rim. The results of these investigations are also shown in Table 1.

The rolling resistance was measured by the coasting method, and tire internal pressure: 170 kPa and load: JI.
The test was conducted under the conditions of S100% load and coasting start temperature: 100 km, and the work amount corresponding to the rolling resistance of the tire was obtained from the speed decrease curve of the coasting drum. The measurement result is shown as an index when the result of the tire of Comparative Example 1 is 100. The smaller this value is, the smaller the rolling resistance is. The results of these investigations are also shown in Table 1.

Here, the thermal expansion starting temperature of the particles in Table 2 was measured, the internal volume of the tire-rim assembly was measured, the recovery behavior of the particle volume was investigated, and the ratio of the average film thickness to the average particle diameter of the particles was determined. Each calculation method is as follows. [Measurement Method of Thermal Expansion Start Temperature of Particles] The thermal expansion start temperature in Table 2 was measured by measuring the expansion displacement amount under the following conditions and used as the temperature at the rise of the displacement amount. Equipment: Nishizawa PERKIN-ELMER 7 Series (Thermal Analysis System) Measurement conditions: Temperature rising rate 10 ° C / min, measurement start temperature 25
℃, end temperature of measurement 200 ℃, measurement physical quantity: measure the expansion displacement due to heating. Table 2 shows the measurement results of the thermal expansion start temperature of the particles used in the present invention.

[Method of Measuring Inner Volume of Tire-Rim Assembly] The method of measuring the inner volume of the tire-rim assembly will be described by the following procedure. Step 1-1: The tire-rim assembly is filled with an incompressible fluid such as water having a known specific gravity at atmospheric pressure while the tire-rim assembly is kept unloaded, and the tire-rim assembly is measured by weighing after filling. The initial internal volume V ₀ (liter) of is obtained. According to the above procedure, the internal volume of the tire and rim assembly was determined in the unloaded state when the tire internal pressure was atmospheric pressure.

Step 2-1: With the tire and rim assembly held in a state in which no load is applied, air at room temperature is filled to obtain a predetermined internal pressure P ₂ . At this time, the tire expands due to the internal pressure, and the internal volume V ₂ at the predetermined internal pressure increases more than the initial internal volume V ₀ .

Procedure 2-2: The tire valve is opened, and the volume V ₁ of the discharged air under atmospheric pressure is measured by the integrating flowmeter. At this time, the tire expanded to V ₂ by the internal pressure returns to the initial internal volume V ₀ . The integrated flow meter is a DC DRY gas meter manufactured by Shinagawa Seiki.
DC-2C, intelligent counter SSF was used.

Step 2-3: P ₁ × (V ₀ + V ₁ ) = P ₂ × V ₂ Equation (1) According to the equation (1), the tire internal volume V ₂ at a predetermined internal pressure is obtained. . Here, V ₀ = initial internal volume of the tire and rim assembly (liter) P ₁ = atmospheric pressure (absolute pressure: kPa) V ₁ = air volume at atmospheric pressure (liter) P ₂ = predetermined internal pressure (absolute Pressure: kPa) V ₂ = Internal volume of tire-rim assembly with no load set to predetermined internal pressure (liter) The volume of the tire-rim assembly without load at each internal pressure was determined by the above procedure.

Step 3-1: Load on tire and rim assembly
Filling with room temperature air while maintaining a non-burden state
Then, the predetermined internal pressure P_TwoTo get Step 3-2: The tire and rim assembly is put on a road surface with a predetermined load.
Internal pressure P _ThreeIs measured with a pressure sensor. This
Since the tire will bend under the load of
Internal volume V of rim and rim assembly_ThreeWith unloaded tires
Internal volume of rim assembly V_TwoLess than. Its internal volume
Due to the reducing action, the tire internal pressure P under load_ThreeIs unloaded
Tire internal pressure P_TwoMore than. The pressure sensor
The amplifier has a built-in amplifier pressure transformer manufactured by Copal Electronics Co., Ltd.
Juicer PA-400-352G was used.

Step 3-3: P ₂ × V ₂ = P ₃ × V ₃ (Equation (2)) of the tire and the rim at the predetermined internal pressure in the unloaded state obtained in Steps 2-1 to ₃ Based on the inner volume V ₂ of the assembly and the equation (2), the inner volume V ₃ of the tire and the rim under a predetermined load is determined. Here, P ₂ = predetermined internal pressure (absolute pressure: kPa) V ₂ = internal volume of the tire-rim assembly with no load, set to a predetermined internal pressure (liter) P ₃ = predetermined internal pressure a tire, a tire inner pressure when applying a predetermined load (absolute pressure: kPa) V 3 ₌ the tire set to a predetermined internal pressure, the internal volume of the tire-rim assembly when applying a predetermined load (l)

By the above procedure, the volume of the tire / rim assembly under load at each internal pressure was determined. Table 4 shows the internal volume measurement results of the tire-rim assembly under each internal pressure and each load according to the above procedure.

[Measurement of recovery behavior of total volume of particles under high pressure]
A cylindrical pressure-resistant container made of transparent acrylic resin having an internal volume of 10 liters is prepared, and the particles of the present invention are charged into the container while vibrating the container with an ultrasonic water bath or the like. Next, the height of the inside of the container under atmospheric pressure, that is, the height of the container filled with particles (hereinafter referred to as the container height)
After measuring, the container and the nitrogen cylinder are connected to each other, and nitrogen gas is filled until the pressure reaches a pressure designated by the vehicle. As the pressure increases, the volume of particles in the container decreases, and the filling height of particles decreases. When the pressure inside the container reaches the target pressure,
After shaking the container for 5 minutes with an ultrasonic water bath or the like, the container is left standing for 5 minutes. Then, when the particle filling height in the container is stable, the height (hereinafter referred to as particle filling height) is measured, and the percentage value of the particle filling height with respect to the container height is calculated. That is, particle volume recovery rate (%) = (particle volume under vehicle specified pressure / particle volume under atmospheric pressure) x 100 = (particle filling height in container under set pressure / container height) x 100

Next, with the above pressure applied, the particle filling height was measured at regular intervals, and the change over time in the particle volume recovery rate according to the above equation was recorded, and the particle filling height due to volume recovery was recorded. The measurement is continued until the value does not change. Based on the above measurement results, the time required to reach the target volume recovery rate was determined, and after the tire-rim assembly filled with particles was filled with nitrogen gas at the vehicle specified internal pressure,
The total particle volume recovery procedure was performed according to the recovery time determined.

[Calculation of Ratio of Average Film Thickness to Average Particle Diameter] First, the average particle diameter D of a particle sample 20 cc is measured by a device: Particlc Size Analysis manufactured by HELOS.
The dispersion pressure is 5 bar and the degree of vacuum is 5.0 mbar. Further, the true specific gravity Gp is measured by a liquid displacement method (Archimedes method) using isopropanol. Next, the expanded particles are precisely weighed, heated to a temperature 10 ° C. or more higher than the thermal expansion start temperature shown in Table 2 under vacuum, and held for 30 minutes to release the gas in the particles. By cooling this to room temperature and measuring the volume and weight, the specific gravity Gs of the portion forming the particle film (shell) and the gas weight percentage (gas%) in the foamed particles are determined. Here, the particle volume of the average particle size Vp = 4π / 3 (D / 2) ³ The particle weight of the average particle size Wp = Vp × Gp The weight of the shell portion of the particles of the average particle size Ws = Wp (100−
gas%) / 100 Volume of shell part of particles of average particle size D Vs = Ws / Gs Then, when X is the internal diameter of the expanded particles, Vp−
The relationship of [4π / 3 (X / 2) ³ ] = Vs is established. Therefore, X ³ = 8 (Vp−Vs) 4 / 3π. From the above, the film thickness value S was calculated from the film thickness S = 8 (D−X) / 2 based on the X value.

[0093]

[Table 1]

[0094]

[Table 2]

[0095]

[Table 3]

[0096]

[Table 4]

[0097]

According to the present invention, a safety tire that enables stable running even in a tire-damaged state without sacrificing rolling resistance and riding comfort during normal running before the tire is damaged, and A rim assembly can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view in a tire width direction showing a safety tire and a rim assembly according to the present invention.

[Explanation of symbols]

1 tire 2 rims 3 particles 4 bead part 5 carcass 6 belts 7 tread 8 Inner liner layer

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08J 9/04 101 C08J 9/04 101 CER CER // C08L 101: 00 C08L 101: 00

Claims (12)

[Claims] 1. A tire is attached to an applicable rim, and a large number of substantially spherical particles composed of a continuous phase and closed cells made of a resin are provided inside a tire partitioned by the tire and the applicable rim. Value and the lower limit of the filling volume, the ratio of the average film thickness to the average particle size of the particles is 0.00
An assembly of a tire and a rim, which is 6 or less. The upper limit of the filling volume: A tire and rim assembly adjusted to the internal pressure specified by the vehicle on which the tire and rim assembly is mounted is mounted on the vehicle, and the load applied to each axle of the vehicle is Inner volume of the assembly when loaded. Lower limit of filling volume: A tire-rim assembly having an internal pressure set to atmospheric pressure is mounted on the vehicle, and a load of 2.0 times the load applied to each axle of the vehicle at the upper limit is applied to the tire and the rim. Inner volume of the assembly when and is loaded. However, the filling volume of particles refers to the total volume of all particles filled inside the tire-rim assembly under atmospheric pressure, and includes the void volume around the particles. 2. The tire / rim assembly according to claim 1, wherein the ratio of the average film thickness to the average particle size of the particles is 0.005 or less. 3. The tire / rim assembly according to claim 1, wherein the ratio of the average film thickness to the average particle size of the particles is 0.004 or less. 4. The method according to any one of claims 1 to 3,
The total volume of the particles placed inside the tire under the internal pressure specified by the vehicle is 8 times the total volume of the particles under atmospheric pressure.
A tire-rim assembly comprising 0% or more. 5. The method according to any one of claims 1 to 4,
An assembly of a tire and a rim, wherein a continuous phase of particles is made of at least one selected from a polyvinyl alcohol resin, an acrylonitrile polymer, an acrylic polymer and a vinylidene chloride polymer. 6. The method according to any one of claims 1 to 5,
The continuous phase of the particles is composed of an acrylonitrile-based polymer, and the acrylonitrile-based polymer includes an acrylonitrile polymer, an acrylonitrile / methacrylonitrile copolymer, an acrylonitrile / methylmethacrylate copolymer and an acrylonitrile / methacrylonitrile / methylmethacrylate ternary copolymer. A tire-rim assembly comprising at least one selected from a combination. 7. The method according to any one of claims 1 to 5,
The continuous phase of the particles is made of an acrylic polymer, and the acrylic polymer is a methyl methacrylate resin, a methyl methacrylate / acrylonitrile copolymer, a methyl methacrylate / methacrylonitrile copolymer and a methyl methacrylate / acrylonitrile / methacrylonitrile terpolymer. A tire-rim assembly comprising at least one selected from polymers. 8. The method according to any one of claims 1 to 5,
The continuous phase of the particles is composed of vinylidene chloride-based polymer, and the vinylidene chloride-based polymer includes vinylidene chloride / acrylonitrile copolymer, vinylidene chloride / methyl methacrylate copolymer, vinylidene chloride / methacrylonitrile copolymer, vinylidene chloride / At least one selected from acrylonitrile / methacrylonitrile copolymer, vinylidene chloride / acrylonitrile / methyl methacrylate copolymer, vinylidene chloride / methacrylonitrile / methyl methacrylate copolymer and vinylidene chloride / acrylonitrile / methacrylonitrile / methyl methacrylate copolymer A tire and rim assembly characterized by being a seed. 9. The method according to claim 1, wherein
In the bubbles of the particles, nitrogen, air, linear and branched aliphatic hydrocarbons having 2 to 8 carbon atoms and fluorinated compounds thereof,
An alicyclic hydrocarbon having 2 to 8 carbon atoms and a fluorinated product thereof, and the following general formula (I): R ¹ —O—R ² ---- (I) (wherein R ¹ and R ² are Each independently has 1 carbon
At least 1 selected from the group consisting of a monovalent hydrocarbon group of 5 to 5 and some of the hydrogen atoms of the hydrocarbon group may be replaced with fluorine atoms). A tire and rim assembly having a species of gas. 10. The inner liner layer according to claim 9, further comprising an inner liner layer on an inner peripheral surface of the tire.
Gas permeation coefficient at ℃ is 20 × 10 ^-12 (cc · cm
/ Cm ² · s · cmHg) or less, a tire-rim assembly. 11. The tire internal pressure drop alarm function based on the wheel speed detection by the wheel speed sensor of the antilock brake system according to claim 1, and the tire internal pressure drop based on the method of directly measuring the tire internal pressure by the pressure sensor. A tire and rim assembly with either or both alarm functions. 12. A foamable composition containing the following resin (A) and one or both of the following thermally decomposable foaming agent (B) and the following foaming agent (C). (A) At least one kind selected from polyvinyl alcohol resin, acrylonitrile-based polymer, acrylic polymer and vinylidene chloride-based polymer (B) dinitrosopentamethylenetetramine, azodicarbonamide, paratoluenesulfonylhydrazine and derivatives thereof. And at least one (C) linear or branched aliphatic hydrocarbon having 2 to 8 carbon atoms selected from oxybisbenzenesulfonylhydrazine and its fluorinated product, and alicyclic hydrocarbon having 2 to 8 carbon atoms And a fluorinated compound thereof, and the following general formula (I): R ¹ —O—R ² ---- (I) (R ¹ and R ² in the formula each independently have 1 carbon atom.
To 5 monovalent hydrocarbon groups, in which a part of the hydrogen atoms of the hydrocarbon groups may be replaced by fluorine atoms), at least one selected from ether compounds