JP2003048411A - Safety tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety tire enabling stable traveling even when the tire is damaged without sacrificing the rolling resistance and the ride quality during the normal traveling before the tire is damaged. SOLUTION: An internal space of a hollow doughnut-shaped tire is divided into a plurality of chambers, the gas is filled in at least one of the plurality of chambers, a compound material with closed bubbles diffused in a continuous phase of a polymer is disposed in at least one of the remaining chambers, the internal pressure at 25 deg.C of the bubbles in the compound material is set to be >=150 kPa by the absolute pressure, and the expansion starting time of the compound material is set to be 80-180 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety tire which is not affected by a flat tire due to external damage or the like, and more particularly to a safety tire which is excellent in durability and riding comfort in running after the tire is damaged.

[0002]

2. Description of the Related Art Pneumatic tires, for example, passenger car tires, have an air pressure of 250 to 350, which is a vacuum-based absolute pressure (hereinafter, simply referred to as internal pressure).
By maintaining the kPa at about kPa, tension is generated in the tire skeleton portion such as the carcass and belt of the tire, and this tension enables deformation and restoration of the tire with respect to input to the tire. That is, by maintaining the internal pressure of the tire within a predetermined range, a constant tension is generated in the skeleton of the tire to provide a load supporting function,
By increasing the rigidity, it provides the basic performance required for running the vehicle, 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 safety tires that enable traveling even in a punctured state. For example, as a pneumatic safety tire for automobiles,
Various types such as those having a double wall structure, those in which a load supporting device is arranged in the tire, and those in which tire side portions are reinforced have been 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 longitudinal spring constant and the front-rear spring constant of the tire, there is a disadvantage that rolling resistance is significantly deteriorated and 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 relatively high speed and long distance running, a core or the like is formed on the rim. A run flat tire having a structure in which an internal support is arranged to support a load during puncture is mainly applied.

However, the tire cannot withstand the local repetitive input generated between the tire and the internal support during the run-flat after the puncture, and as a result, the mileage after the puncture is about 100 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 conventional safety tires can exhibit the 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, the tire flexure is naturally small and maintains a shape close to a circle, so when the vehicle starts to move due to the driving force generated from the driving wheels at the time of start, the idle wheels will move as the vehicle moves. Start rolling. However, in the state after the puncture, the tire is largely bent, and the shape deviates from the circular shape. The idle wheel is a wheel that cannot roll on its own, that is, cannot generate a driving force. Therefore, 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)" 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 a "braking force adjustment function" that avoids tire lock during braking (Anti-lock brake system) "is not fully exerted, and there is a risk that the vehicle may become out of control due to malfunction. In particular,
Needless to say, in a vehicle in which the front wheels are idle wheels and the steered wheels, and the rear wheels are the drive wheels, the puncture of the front wheels causes the steering performance to be extremely reduced, resulting in a very dangerous state.

Further, a tire in which a closed-cell foam is filled in the inner cavity of an assembly of a tire and a rim to be assembled to the tire is disclosed in, for example, Japanese Patent Application Laid-Open No. 6-127207 and Japanese Patent Application Laid-Open No. 6-127207.
No. 183226, JP-A-7-186610 and JP-A-8-332805. The tires proposed for these are mainly agricultural tires,
It is limited to special or small tires such as rally tires, two-wheeled vehicle 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 all the foams have a low expansion ratio, they are heavy in weight in comparison with the composite having bubbles, and it is inevitable that vibration and riding comfort and fuel consumption are deteriorated, and 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 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, the foam heats up due to the repeated deformation during rolling of the tire, and the durability is significantly reduced. In addition, since it is difficult to form air bubbles independently of each other, it is difficult for the air bubbles to communicate with each other and it is difficult to hold the gas. Particularly, in running after the tire is damaged, a desired tire internal pressure (load supporting capacity or It has the disadvantage that it cannot retain its ability to suppress deflection, and so on.

[0012]

Therefore, the present invention is
An object of the present invention is to propose a safety tire that enables stable running even after the tire is damaged without sacrificing rolling resistance and riding comfort during normal running.

[0013]

Means for Solving the Problems The inventors of the present invention have made earnest studies to solve the above-mentioned problems, and found that in order to always maintain the internal pressure of the tire properly, the tire internal It has been found that it is effective to provide a structure in which gas does not leak from the. That is, the gist of the present invention is as follows.

(1) The inner space of a hollow donut-shaped tire is divided into a plurality of chambers, at least one of the plurality of chambers is filled with gas, and the remaining at least one chamber is filled with closed cells in a continuous phase of a polymer. The dispersed composite is placed, and the internal pressure at 25 ° C. of the bubbles contained in the composite is 150 in absolute pressure.
kPa or more, and the expansion start temperature of the composite is 80
A safety tire having a temperature of up to 180 ° C.

(2) A safety tire according to the above (1), characterized in that the partition wall for partitioning the plurality of chambers is made of a rubber composition containing butyl rubber in an amount of 50 mass% or more.

(3) A safety tire according to the above (1) or (2), wherein the expansion start temperature of the composite is 90 to 160 ° C.

(4) In the above item (3), the composite A has an expansion start temperature of 90 to 160 ° C., and a composite having an expansion start temperature higher than the expansion start temperature of the composite A by 10 ° C. or more. A safety tire including B.

(5) A safety tire according to the above (4), wherein the weight ratio of the composite B to the composite A is 0.1 to 2.0.

(6) In the above (1) to (5), the composite is a pyrolyzable foaming agent, liquefied fluorinated ethane, and liquefied C3-C8 linear aliphatic carbon. Hydrogen and its fluorinated product, liquefied C 3-8 branched aliphatic hydrocarbon and its fluorinated product, and liquefied C 3-8 alicyclic hydrocarbon and its fluorinated product. A safety tire, which is a composite obtained by causing at least one of the compounds to function as a foaming agent.

(7) In the above (6), the thermally decomposable foaming agent is
A safety tire comprising at least one selected from dinitrosopentamethylenetetramine, azodicarbonamide, paratoluenesulfonylhydrazine and its derivatives, and oxybisbenzenesulfonylhydrazine.

(8) The safety tire according to any one of (1) to (7) above, wherein the composite is composed of a resin continuous phase and closed cells.

(9) In any one of the above (1) to (8), the continuous phase of the composite is an acrylonitrile copolymer,
At least one of acrylic copolymer, vinylidene chloride copolymer, acrylonitrile / styrene resin, polyethylene resin, polypropylene resin, polyester resin, polystyrene / polyethylene copolymer, polyvinyl alcohol resin and nylon resin Safety tires characterized by.

(10) In any one of the above (1) to (9), the continuous phase of the composite is an acrylonitrile polymer, and the acrylonitrile polymer is an acrylonitrile polymer or an acrylonitrile / methacrylonitrile copolymer. A safety tire comprising at least one selected from acrylonitrile / methyl methacrylate copolymer and acrylonitrile / methacrylonitrile / methyl methacrylate terpolymer.

(11) In any one of (1) to (9) above, the continuous phase of the composite is made of an acrylic copolymer, and the acrylic copolymer is a methyl methacrylate resin or a methyl methacrylate / acrylonitrile copolymer. A safety tire comprising at least one selected from a polymer, a methyl methacrylate / methacrylonitrile copolymer, and a methyl methacrylate / acrylonitrile / methacrylonitrile terpolymer.

(12) In any one of the above (1) to (9), the continuous phase of the composite is a vinylidene chloride copolymer, and the vinylidene chloride copolymer is 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 / Methylmethacrylate copolymer, vinylidene chloride / acrylonitrile / methacrylonitrile / methylmethacrylate copolymer, at least one selected from the safety tires.

(13) In any one of the above (1) to (12), nitrogen, air, carbon dioxide,
Fluorinated products of ethane, linear aliphatic hydrocarbons having 3 to 8 carbon atoms and fluorinated products thereof, branched aliphatic hydrocarbons having 3 to 8 carbon atoms and fluorinated products thereof, and 3 to 8 carbon atoms
8. A safety tire comprising at least one gas selected from the alicyclic hydrocarbons of 8 and their fluorinated compounds.

(14) A safety tire according to any one of (1) to (13) above, wherein the internal pressure of the air bubbles contained in the composite at 25 ° C. is 200 kPa or more in absolute pressure.

(15) A safety tire according to the above (14), characterized in that the fluorinated gas among the gas components in the closed cells of the composite is sealed at 50 mass% or more.

(16) In any one of the above (1) to (15), the composite has a cell content of 80.00% by volume to 98.
A safety tire characterized by being 75% by volume.

(17) In any one of the above (1) to (16), the composite is a hollow particle obtained by heating and expanding a foamable composition in which a gas component is liquefied and encapsulated in a polymer particle. A safety tire including:

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION A safety tire according to the present invention will be described below with reference to FIGS. 1 and 2 showing cross sections in the width direction. That is, the safety tire of FIG. 1 has a plurality of chambers in the inner space of the tire 1, and in the illustrated example, the tire 1
Is divided into two chambers 2 and 3 which are continuous in the circumferential direction, and at least one of these chambers, the chamber 2 in the illustrated example, is filled with a gas such as air or nitrogen, and the remaining at least one chamber, the illustrated chamber 3, a composite 4 in which closed cells are dispersed in a continuous phase made of a polymer is 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 typical automobile tire,
A belt 7 and a tread 8 are sequentially arranged radially outward of a crown portion of a carcass 6 extending in a toroidal shape between a pair of bead cores 5. In the figure, reference numeral 9
Is an inner liner layer and 10 is a rim.

Further, the composite body 4 has closed cells in which individual bubbles are isolated by being surrounded by partition walls,
The internal pressure at 25 ° C. of the closed cells in the composite 4 was set to 15
It is important to set it to 0 kPa or more, preferably 200 kPa or more. Internal pressure of closed cells at 25 ℃ is 150
If the kPa is less than kPa, the flexure of the composite increases and the amount of repeated deformation during rolling of the tire increases, so that the fatigue history of the composite during normal running before tire damage increases and the composite caused by tire damage The rate of damage progression increases as the amount of deformation increases, and in this case also, the durability of the composite against repeated deformation remarkably decreases, and the performance during running in a tire-damaged state becomes insufficient. Here, the internal pressure value is expressed by assuming that the normal pressure (atmospheric pressure) is 100 kPa.
That is, the internal pressure of 200 kPa indicates that the pressure is twice the atmospheric pressure.

Further, it is essential that the composite 4 has an expansion starting temperature of 80 to 180 ° C. Here, the composite includes an unexpanded foamable composition, and when the composite reaches a certain temperature by heating the composite under a constant temperature rising condition, the continuous foamable composition The polymer and foaming agent that make up the phase become active, and the vaporization or thermal decomposition of the foaming agent trapped in the polymer is promoted, while the surrounding polymer softens, further promoting vaporization or thermal decomposition. As a result, foaming occurs and the composite expands. The primary cause of expansion of this composite is due to the unexpanded foamable composition contained therein. Therefore, in this invention, in order to grasp the expansion characteristics of each foamable composition, at a constant temperature rising rate, the displacement amount corresponding to the volume change due to expansion is measured, and the temperature at the rise of the displacement amount It was defined as the starting temperature.

The tire internal temperature under the conditions of use on the general market is about 50 to 60 ° C. However, when the composite is placed inside the tire, the internal temperature of the tire is further increased due to the heat storage characteristics of the composite. It is easy to guess. That is, if the expansion start temperature of the foamable composition to be the composite is set too low, the internal temperature of the tire may exceed the expansion start temperature. When the internal temperature of the tire exceeds the expansion start temperature, the flow of the continuous phase forming the composite and the thermal expansion of the bubbles cause disorder in the bubble structure, communication of the bubbles, and a significant increase in gas permeability of the continuous phase. It will be. If the tire is damaged under such a condition, it will not be able to exert its intended load supporting function, and the vehicle will be unable to run. Therefore, in order to surely exhibit the function of the safety tire having the composite arranged inside the tire, which is expected in the present invention, the expansion starts to a temperature range of 80 ° C. or higher which is sufficient to avoid the above-mentioned problems. It is essential to choose a foamable composition that has a temperature.

Further, it is preferable that the foamable composition to be the composite 4 is formed by combining foamable compositions having different expansion start temperatures. Because, by mixing the foamable composition having a different expansion start temperature, the tire temperature increases, and when the tire temperature reaches a certain value or more, in the foamable composition having a high expansion start temperature scattered in the composite. When the foaming agent causes foaming due to thermal decomposition or when the liquefied gas is vaporized, heat generation of the tire is consumed, so that the tire temperature is suppressed from rising and the heat aging of the tire is also suppressed. Also,
Under running after tire damage, the temperature inside the tire tends to rise with the running distance, and the expandable composition having a high expansion start temperature exerts thermal expansion force due to foaming during running, and thus the running distance is further increased. Can be extended.

In particular, the composite has a expansion start temperature of 90 to 16 which constitutes the composite in the tire during normal use.
It is preferable to include a composite A having a continuous phase of 0 ° C. and a composite B having a continuous phase having an expansion starting temperature higher than the expansion starting temperature of the composite A by 10 ° C. or more. This is because when the expansion start temperature of the composite A is less than 90 ° C., the continuous phase of the composite melts due to the tire heat generation during normal use, the closed cells may communicate with each other, and the gas permeability of the continuous phase may increase. There is. Further, if the expansion start temperature of the composite A exceeds 160 ° C., the thermal expansion force due to the heat generation at the initial stage of tire damage is small, and there is a concern that the running ability immediately after the damage cannot be guaranteed.

On the other hand, since the composite B has a function of recovering the internal pressure by exerting an expanding force while expanding and absorbing heat for the first time under abnormal heat generation at a low internal pressure running due to tire damage, for example, It must be in an unexpanded state during use. Further, in the method of producing a composite in the tire after the rim assembly, only the composite A needs to be surely heated and expanded. For that purpose, the temperature at the time of heating the tire is set to the expansion start of the composite A. Selective expansion becomes difficult unless the temperature is set higher than at least 5 ° C. Therefore, the expansion start temperature of the composite B needs to be higher than the softening point of the composite A by 10 ° C. or higher, preferably 20 ° C. or higher.

Further, the weight ratio of the composite B to the composite A is preferably 0.1 to 2.0. Because
When the weight ratio of the composite B to the composite A is less than 0.1,
Even if the composite B exerts an expansive force due to abnormal heat generation of the tire, since its absolute amount is small, the endothermic effect and the internal pressure recovery effect are small, so that the effect of extending the travelable distance after the tire is damaged becomes small. If the weight ratio exceeds 2.0, since the expansion force due to the heat generation at the time of tire damage based on the composite A is small, the running ability immediately after the damage cannot be guaranteed, and the tire weight is affected, and the tire weight This will lead to deterioration of rolling resistance due to the increase.

As the composite A, a composite which generates a main internal pressure during normal use is required, and a continuous phase having a low gas permeability described later and a gas having a high vapor pressure even at a low temperature such as nitrogen. , Air, carbon dioxide, liquefied fluorinated ethane, liquefied C3-C8 linear aliphatic hydrocarbon and its fluorinated product, liquefied C3-C8 branched aliphatic hydrocarbon And fluorinated compounds thereof, and liquefied alicyclic hydrocarbons having 3 to 8 carbon atoms and combinations thereof with fluorinated compounds are advantageous.

On the other hand, the composite B is a continuous phase having a low gas permeability even at high temperatures, in order to exert the effect of absorbing heat and recovering the internal pressure by foaming at the time of abnormal heat generation of the tire and exerting a thermal expansion force, For example, an acrylonitrile-based copolymer, a thermally decomposable foaming agent, a liquefied ethane fluoride, a liquefied linear aliphatic hydrocarbon having 3 to 8 carbon atoms and a fluorinated product thereof, and a liquefied carbon number of 3 to It is advantageous to include at least one blowing agent selected from branched aliphatic hydrocarbons of 8 and fluorinated compounds thereof, and liquefied alicyclic hydrocarbons of 3 to 8 carbons and fluorinated compounds thereof. .

In particular, the composite B is advantageously suitable in combination with isopentane, neopentane, isooctane, etc., which gasify at a high temperature to start foaming, that is, have a relatively low vapor pressure.

Further, at least one selected from dinitrosopentamethylenetetramine, azodicarbonamide, paratoluenesulfonylhydrazine and its derivatives, and oxybisbenzenesulfonylhydrazine may be used as the above-mentioned thermally decomposable foaming agent.

Here, in the safety tire of FIG. 1, as a device for maximizing the durability of the composite, the chamber 2 is filled with gas, preferably at about 200 to 300 kPa,
During normal driving (before tire damage), it is advantageous to positively compress the composite in the tire. With this device, it is possible to reduce the load bearing ratio of the complex during normal running, and it is possible to reduce the fatigue history associated with repeated deformation during rolling of the tire. Therefore, even if the air filled between the composite and the tire inner surface is dissipated due to tire damage, the running performance in a tire damaged state is significantly improved compared to the case where the above method is not adopted.

By disposing such a composite body 4 and applying a predetermined internal pressure to the tire, an essential internal pressure is applied to the tire. That is, instead of filling the inside of the tire with air, the composite body 4 is arranged inside the tire,
A structure capable of applying a predetermined internal pressure to the tire to generate tension in the tire skeleton such as the carcass and belt of the tire has been realized. Therefore, since the proper internal pressure is applied to the tire by the composite body 4, it is not necessary to regulate the tire structure itself, and a general-purpose tire and a general-purpose rim can be utilized to provide a new safety tire.

The tire in which the composite body 4 is disposed inside is characterized in that even if the tire is damaged, the tension of the case, unlike a normal pneumatic tire, does not easily decrease. Because when the tire is damaged, a part of the composite body 4 is damaged on the inner surface of the tire near the damage,
The gas in some closed bubbles in this damage can escape to the outside of the tire. However, this phenomenon is similar to that of a conventional pneumatic tire, in which internal pressure drop only occurs in a very small area, and therefore the tire loses tension as a pressure vessel due to partial damage of the composite body 4. In addition, the conventional pneumatic tire does not fall into a flat state. Further, the probability of damage to the composite body 4 due to the external damage of the tire is extremely low, and even if it is damaged, the area thereof is extremely limited. Therefore, the tire internal pressure given by the composite body 4 is lowered so as to impair the tire function. Is impossible.

Moreover, the pressure in the vicinity of the damaged closed bubbles is reduced to the atmospheric pressure, but the closed bubbles in the surrounding area have, for example, 15
As a result of expanding due to having an internal pressure of 0 kPa or more,
The damaged closed-cell region is compressed and the damaged site is closed, and so-called self-repair becomes possible.

The above state is a state in which the composite directly or indirectly bears a load to provide the minimum tire internal pressure required for running. The tire deflection in this state is relatively small, and it is possible to maintain a circular shape compared to the above-mentioned conventional safety tire, and thus it is possible to maintain a relatively uniform contact pressure distribution in the contact tread. By filling the particles of the present invention in a tire mainly used for road surface running in winter such as a studless tire, the basic performance of the studless tire is not deteriorated even after the tire is damaged. That is, even on a road surface having a low coefficient of friction such as on a snowy road, the driving performance such as driveability, braking performance, turning performance, etc. is not significantly deteriorated and the vehicle is not incapable of running.

When arranging a large number of composites inside the tire according to the present invention, it is important to add a liquid that does not substantially swell a continuous layer of the composite inside the tire. By adding this liquid, it is possible to further enhance the sealing function of the tire damaged portion when the tire is damaged and further extend the traveling distance after the tire is damaged. That is,
Since the composite has a substantially spherical shape, it has high fluidity, and therefore, the inside of the tire and the rim assembly can be easily filled from an inlet having a small inner diameter such as a valve of the tire. On the other hand, when the tire is damaged, the composite tends to blow out from the damaged portion to the outside of the tire and collects on the inner surface of the damaged portion. However, since the damaged route from the inner surface of the damaged portion to the outer peripheral surface of the tire has a complicated intricate shape instead of a straight line, the complex entering from the scratch on the inner surface of the tire is blocked on the way of the route, resulting in a large number of composites. The body gathers in a compressed state on the inner surface of the damaged part, and the damaged part is sealed by the composite. At that time, if a liquid is added to the inside of the tire together with the composite, it is possible to collect several to several thousand composites based on the affinity between the surface of the composite and the liquid and the viscosity of the liquid. Therefore, when a tire is damaged, it is possible to instantly fill the damaged portion with the composite body.

Further, since the liquid to be mixed has a significantly higher specific gravity than the composite, under normal running, a large amount of liquid will be distributed on the inner surface of the tire tread portion due to the centrifugal force associated with tire rolling. This indicates that there are many composites that are relatively large aggregates 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 composite bodies that are aggregated through a relatively large amount of liquid quickly seal the damaged part, which is extremely effective.

In order to obtain a composite-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 composite is filled in a highly fluid state, in other words, in a dry state before being mixed with the liquid. The composite forms an aggregate by mixing with the liquid as described above. Therefore, the composite mixed with the liquid has extremely low fluidity, which makes it difficult to fill the tire. Therefore, the method of applying the liquid to be mixed to the inner surface of the tire or the inner surface of the rim before the filling or the method of injecting the liquid into the tire and the rim assembly after the filling of the composite is efficient and reliable.

The liquid used here does not swell the continuous phase of the composite or causes a chemical reaction, as described above, and preferably does not cause a swell or a chemical reaction with respect to the inner liner layer. Furthermore, it is required to have performance such as being stable against heat generation during traveling. For example, silicone oil and aliphatic polyhydric alcohols represented by ethylene glycol and propylene glycol can be cited.

Here, in order to apply a predetermined tire internal pressure by the composite 4, the gas enclosed in the closed cells in the composite 4 at a predetermined pressure does not leak out of the composite to the outside of the composite.
In other words, as described above, it is essential that the continuous phase surrounding the closed cells in the composite 4 has a property that gas is difficult to permeate. For that purpose, the continuous phase surrounding the closed cells is Due to the material with low permeability,
Specifically, acrylonitrile polymer, acrylic polymer, vinylidene chloride polymer, acrylonitrile / styrene resin (AS), polyethylene resin (PE), polypropylene resin (PP), polyester resin (PE
T), polystyrene / polyethylene copolymer (PS / P
E), a polyvinyl alcohol resin, or a nylon resin is preferably used. Any of these materials can be formed into a composite in a tire with relative ease, and has flexibility with respect to input due to tire deformation, and thus is particularly effective for the present invention.

In particular, it is preferable to apply any one of an acrylonitrile polymer, an acrylic polymer, a vinylidene chloride polymer, a nylon resin and a polyvinyl alcohol resin to the continuous phase of the composite. Further, as an acrylonitrile-based polymer, acrylonitrile /
Methacrylonitrile copolymer, acrylonitrile / methyl methacrylate copolymer and acrylonitrile /
At least one selected from methacrylonitrile / methyl methacrylate terpolymer, as the acrylic polymer, methyl methacrylate resin, methyl methacrylate / acrylonitrile copolymer and methyl methacrylate / acrylonitrile / methacrylonitrile terpolymer At least one selected vinylidene chloride-based polymer is vinylidene chloride / acrylonitrile copolymer, vinylidene chloride / methylmethacrylate copolymer, vinylidene chloride / methacrylonitrile copolymer, vinylidene chloride / acrylonitrile / methylmethacrylate copolymer Coalescence, vinylidene chloride / acrylonitrile / methacrylonitrile copolymer, vinylidene chloride / methacrylonitrile / methyl methacrylate copolymer,
And at least one selected from vinylidene chloride / methyl methacrylate / acrylonitrile / methacrylonitrile copolymer, and as a nylon resin,
Nylon 6, Nylon 11, Nylon 12, Nylon 6
At least one selected from the / 66 copolymer and the nylon 6/12 copolymer are each suitable. Since all of these materials have a small gas permeability coefficient and a low gas permeability, the gas inside the closed bubbles does not leak to the outside, and the internal pressure of the closed bubbles can be maintained within a predetermined range.

Next, the continuous phase of the composite at 30 ° C.
Gas permeability coefficient is 300 × 10^-12 (Cc · cm / cm² 
・ S · cmHg) or less, preferably gas at 30 ° C.
Transmission coefficient is 20 × 10^-12 (Cc · cm / cm² ・ S ・
cmHg) or less, more preferably gas at 30 ° C.
Transmission coefficient is 2 × 10^-12 (Cc · cm / cm² ・ S ・ c
mHg) or less is recommended. This is usually
Of inner liner layer of pneumatic tires
Over coefficient is 300 × 10^-12 (Cc · cm / cm ² ・ S ・
cmHg) and a sufficient internal pressure holding function at a level below
Considering the track record that we have, the continuous phase of the composite is also 3
Gas permeation coefficient at 0 ° C is 300 × 10^-12 (Cc ・
cm / cm² ・ S · cmHg) or less.
However, at this level of gas permeability coefficient,
It is necessary to replenish the internal pressure about once.
20 × 10 from the standpoint of performance^-12 (Cc · cm / cm² 
· S · cmHg) or less, more preferably 2 × 10^-12 
(Cc · cm / cm² ・ S ・ cmHg) or less
Is recommended.

By using a normal device for filling the tire with air, or by arranging the tire in a closed chamber in which a desired gas is filled and kept at a predetermined internal pressure, the gas is refilled in the bubble to obtain the internal pressure of the bubble. Can be readjusted, but when a polymer having a large gas permeation coefficient is used in the continuous phase, this refilling operation must be performed frequently, which is not practical.

In the closed cells of the composite, fluorinated compounds of nitrogen, air, carbon dioxide, ethane, linear aliphatic hydrocarbons having 3 to 8 carbon atoms and fluorinated compounds thereof, and 3 to 8 carbon atoms are contained. It is preferable that at least one selected from the group consisting of the branched aliphatic hydrocarbons and fluorinated compounds thereof, and the alicyclic hydrocarbons having 3 to 8 carbon atoms and fluorinated compounds thereof is encapsulated. That is, as the foaming agent for obtaining the composite, a pyrolyzable foaming agent, a fluorinated product of ethane, a linear aliphatic hydrocarbon having 3 to 8 carbon atoms and its fluorinated product, and a fluorinated product having 3 to 8 carbon atoms are used. Examples thereof include liquefied branched aliphatic hydrocarbons and fluorinated products thereof, and alicyclic hydrocarbons having 3 to 8 carbon atoms and fluorinated products thereof.

Many of the thermally decomposable foaming agents are characterized by generating nitrogen by thermal decomposition, and the composite obtained by appropriately controlling the reaction has nitrogen in its bubbles. As the heat-decomposable foaming agent, at least one selected from dinitrosopentamethylenetetramine (DPT), azodicarbonamide (ADCA), paratoluenesulfonylhydrazine (TSH) and its derivatives, and oxybisbenzenesulfonylhydrazine (OBSH). Is appropriate. A desired composite can be obtained by blending these thermally decomposable foaming agents with the resin constituting the molten continuous phase.

When the continuous phase forming the composite is melted and filled in the tire with air at high pressure to form the composite, air remains in the bubbles.

Further, during the 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.

Furthermore, the expandable resin particles containing a liquefied gas such as propane, butane and pentane are filled in the tire together with the melt of the continuous phase forming the composite, and the inside is heated. It is also possible to obtain a tire in which the composite is arranged.

The desired tire can be obtained by heating and foaming the surface of the expandable resin particles coated with a surface active agent, an oil agent or the like in the tire. Furthermore, the target tire can also be obtained by preliminarily heat-foaming the resin particles containing the liquefied gas to form hollow particles having a substantially spherical shape and filling the hollow particles in the tire.

Finally, the bubble content rate in the composite 4 is 8
It is preferably from 0.00% by volume to 98.75% by volume. This is because if the content of bubbles is less than 80.00% by volume, when the composite is deformed inside the tire, stress is sporadically concentrated in the continuous phase portion between the bubbles, and cracks are likely to occur in the continuous phase, which causes repeated The durability of the composite against deformation is significantly reduced. Further, when the bubble content rate exceeds 98.75% by volume, the degree of damage to the composite due to the tire damage increases and the rate of propagation thereof also increases,
Also in this case, the durability of the composite against repeated deformation is significantly reduced.

Here, the bubble content rate is a percentage of the volume of the bubble volume with respect to the volume of the composite material placed inside the tire and is expressed by the following formula. You can Bubble content = {1- (volume of resin or composition constituting composite / indoor volume)} × 100, where "volume of resin or composition constituting composite" in the above formula , Refers to the volume of the composition in the previous step of forming closed cells by foaming due to heating or the like, and is therefore a volume value not including closed cell volume.

The volume of the resin or composition constituting the composite to be used is determined, for example, by weighing out the composition in advance in a container of known volume under atmospheric pressure.
In particular, when the resin or composition constituting the composite is in the form of particles, the composition is weighed in a graduated cylinder under atmospheric pressure, and the graduated cylinder is immersed in an ultrasonic water bath and vibration is applied to the composition. The volume value when the packing between the object particles is stable was adopted. Therefore, when the resin or composition is in the form of particles, the volume used means the sum of the total volume of the particles and the total volume of voids between the particles of the composition.

The safety tire of the present invention is particularly characterized in that the internal pressure of the closed cells of the composite body arranged inside is higher than the atmospheric pressure. To realize such a safety tire, Much depends on the following new manufacturing method. The manufacturing method will be specifically described below, but in any method, it is preferable to monitor the tire internal pressure and the tire internal temperature during the manufacturing process and control the generation and growth of bubbles while appropriately adjusting.

In the first method, after the foamable composition constituting the composite is placed inside the tire, the tire is incorporated into the rim, and then the tire assembly is heated to foam the inside of the tire. is there. The heating can be performed by using microwaves or electron beams in addition to the oven or steam, and this is the same in the following method.

The second method is, for example, Expancel (trademark) or the like, in which a foamable composition which is resin particles in which bubble gas such as butane, propane or pentane is liquefied and enclosed is rim-assembled into a tire assembly. It is injected into the inside of the solid body, and then the tire assembly is heated to foam the inside of the tire.

In particular, when the component gas composition containing an aliphatic fluorocarbon containing no chlorine is used as the gas bubble of the composite, each of the above methods can be used, but the following method is suitable. That is, the third method is tetrafluoroethane, difluoroethane, fluoroethane, octafluoropropane, 2H-heptafluoropropane,
A foamable composition that is a resin particle in which bubble gas such as decafluorobutane, cyclofluorobutane, and dodecafluoropentane is liquefied and encapsulated is injected into the tire assembly after the rim assembly, and then the tire assembly is heated, Foaming is performed inside the tire. In this case, the continuous phase of the composite becomes the polymer that constitutes the resin particles.

In the fourth method, a foamable composition, which is a resin particle in which bubble gas such as butane, propane or pentane is liquefied and encapsulated, such as, for example, Expancel under the trade name, is preliminarily heated and foamed. Spherical hollow particles are filled in the tire and rim assembly. In this case, the continuous phase of the composite refers to a polymer forming the shell of the resin particles. In particular, each of the above methods can be used even when the composition of the bubbles containing aliphatic fluorocarbon containing no chlorine is used as the gas bubble of the composite.

When the chamber 3 is filled with the composite material by the above-mentioned method, after the partition walls for partitioning the plurality of chambers have been installed in the tire assembly in advance, a gas having a volume equal to or larger than the tire internal volume is filled in the chamber 2. Encapsulate. At this time, the chamber 3 and the outside air need to communicate with each other through a valve or the like mounted on the wheel. Thereby, the volume of the chamber 3 can be substantially zero. Next, a negative pressure can be generated in the chamber 3 by sucking the gas filled in the chamber 2, and the negative pressure generated is used to introduce the foamable composition into the chamber 3. Meanwhile, the chamber 2 filled with gas can be formed. Further, in the chamber 3, a gas such as nitrogen or air can be mixed in addition to the composite.

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 softening point of 170 to 230 ° C. and an isobutylene paramethylstyrene copolymer. It is preferable that the thermoplastic elastomer composition is formed by dynamically vulcanizing an elastomer component containing a halide to a gelation rate of 50 to 95%. This is because, unlike the conventional inner liner layer mainly composed of butyl rubber, by using a nylon resin as a continuous phase, the gas permeation resistance becomes extremely good, and as a result, the function of the inner liner layer can be strengthened. On the other hand, the gelling ratio of the elastomer component containing the halide of isobutylene paramethylstyrene copolymer is 50 to 50
By using a thermoplastic elastomer composition that is dynamically vulcanized to 95%, an inner liner layer that is highly flexible and has excellent heat resistance and durability can be obtained. The inner liner layer having the above characteristics can create an environment in which the gas in the closed cells of the composite body can easily remain in the bubbles.

The gelation rate means that the pelletized compound after biaxial kneading is Soxhlet extracted 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- (acetone extraction amount + n-hexane extraction amount-stearic acid amount)} / weight of total formulation] × 100

[0073] 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 matrix (continuous phase) forming the composite has high gas permeability, if the gas permeability of the inner liner layer is good, it is possible to prevent the bubble gas in the composite from leaking to the outside of the tire. This is because it is possible to maintain the internal pressure of the tire. That is, the superiority or inferiority of the gas permeability of the inner liner layer is a factor that directly determines the pressure holding property of the tire as a pressure container. Of course, it is fundamental that the continuous phase forming the composite has low gas permeability, and on top of that, it is ideal to use the inner liner layer having low gas permeability.

In the safety tire shown in FIG. 2, the composite body 4 is arranged in the chamber 2 of the safety tire shown in FIG.
Is filled with gas, and the other structure is the same as that of the tire of FIG. That is, the complex 4 in the chamber 2 is filled with gas, for example, air in the chamber 3 so that the complex 4
The inner pressure is compensated for while shrinking the. In this case, when the tire is damaged, the air in the chamber 3 is dissipated to the outside, but the pressure difference generated after the air is dissipated causes the complex 4 to expand, and as a result, the internal pressure is sufficient to allow traveling a limited distance. That is, since the composite can exhibit the deflection suppressing ability and the load supporting function, the run flat tire has sufficient performance.

Here, the state of the partition wall that divides the plurality of chambers is
It will be described below. That is, the partition wall has a melting point of 170 to 23.
An elastomer component containing a 0 ° C. nylon resin and a halide of isobutylene paramethylstyrene copolymer,
It is preferably composed of the thermoplastic elastomer composition dynamically vulcanized to the gelation rate of 50 to 95%. The reason for this is that by using nylon resin as the continuous phase, gas permeability becomes extremely good, and as a result, the function as a tube can be enhanced. Further, by providing a thermoplastic elastomer composition in which an elastomer component containing a halide of an isobutylene paramethylstyrene copolymer is dynamically vulcanized to have a gelation rate of 50 to 95%, it is highly flexible,
In addition, a partition wall having excellent heat resistance and durability can be obtained.

Also in this partition, the gas permeation coefficient at 30 ° C. is 300 × 10 ⁻¹² (cc · cm / cm ² ·.
s · cmHg) or less, preferably 20 × 10 ⁻¹² (c
c · cm / cm ² · s · cmHg) or less, more preferably 2 × 10 ⁻¹² (cc · cm / cm ² · s · cmH)
g) The following is recommended. Because, even if the gas permeability of the continuous phase of the composite is high, if the gas permeability of the partition wall is low, the bubble gas in the composite is less likely to leak outside the partition wall, and the internal pressure of the tire is maintained. This is because it is advantageous to

[0077]

EXAMPLES Example 1 A tire having the structure shown in FIG. 1 or FIG.
The composites of various specifications shown in
Applied as shown in the table, tire size 205 / 60R
15 and a passenger car safety tire-rim assembly having a rim size of 6.0J-15 were prototyped. Here, the tire 1 complies with a general structure of the tire type and size.
The contents of the foamable composition and the additives in Tables 1 and 2 are as shown in Tables 3 and 4, and similarly, the rubber type of the inner liner layer is as shown in Table 5, respectively.

Here, the expansion start temperature in Tables 1, 2 and 3 and Tables 6 and 7 described later is the temperature at the rise of the displacement amount when the expansion displacement amount is measured under the following conditions. . Equipment: Nishizawa PERKIN-ELMER 7 Series
(Thermal Analysis System) Measurement conditions: temperature rising rate 10 ° C./min, measurement start temperature 25
℃, measurement end temperature 200 ℃, measurement physical quantity: measure the expansion displacement due to heating.

Next, Tables 1 and 2 and Table 6 described later
The pressure inside the bubble shown in is based on the following definition.
Was calculated. Bubble pressure (kPa) = [(Wt / ρs) / Vt] 101.325 ---- (A) where: Wt: Weight of the composite filled in the tire chamber Vt: Contents of the chamber used for filling Product ρs: Specific gravity of the composite sampled from the tire under the atmospheric pressure, expressed as ρs = Ws / Vs, where Vs: Volume of the composite sampled from the tire under the atmospheric pressure Ws: Tire Weight of complex sampled from

Then, for the tire-rim assembly filled with the composite, 5000 km and a load of 4.5 were applied.
Before and after running a drum of 8 kN, the amount of change in tire deflection (tire height of tire before running under load-tire height after running under load) was measured, and tire height before running under load of each tire was measured. The index when the height is 100 was obtained for each tire and used as the deflection rate. The smaller this index is, the higher the internal pressure holding performance is and the better the result is.

Each tire / rim assembly after running on the drum was mounted on a 2000 cc class passenger car, and then a tire having a diameter of 3 mm and a length of 3 cm was penetrated from the outside of the tire tread into the tread. After being injured by the method, a load equivalent to that for four passengers was applied, the test course was run at 90 km / h, and a maximum of 300 km was carried out, and the travelable distance was measured.
In addition, as a criterion, a mileage of 200 km or more was determined to be acceptable. The results of these investigations are also shown in Table 1 and Table 2.

[0082]

[Table 1]

[0083]

[Table 2]

[0084]

[Table 3]

[0085]

[Table 4]

[0086]

[Table 5]

By the way, in Comparative Example 3 in Table 2, since the expandable composition having a continuous phase having an expansion starting temperature of 195 ° C. was filled, it was necessary to add a temperature of 200 ° C. or higher for foaming. Therefore, the heat aging of the tire itself was promoted, and although a tire filled with the composite was obtained,
Since the durability of the tire was remarkably reduced, various tests could not be conducted.

Example 2 A composite having various specifications shown in Table 6 was applied to the tire having the structure shown in FIG. 1 or FIG. A / 70R14 passenger car safety tire was built into a 5.5Jx14 rim and prototyped. Here, the tire 1 complies with a general structure of the tire type and size. The contents of the foamable composition and the added foaming agent in Table 6 are as shown in Table 7, and similarly, the rubber type of the inner liner layer is as shown in Table 5.

Each tire-rim assembly thus obtained was run on a drum under 5000 km and a load load of 4.18 kN, and then each tire was mounted on a 2000 cc class passenger car, and then the tire had a diameter of 3 mm and a length of 3 mm. : 3
After causing damage by penetrating the tread from the outside of the tire tread with a cm nail, load a load equivalent to that of 4 passengers, run at 90 km / h on the test course and run up to 500 km. The travelable distance was measured. Then, it is displayed as an index when the runnable distance in each comparative example corresponding to each invention example is 100. The larger this value is, the better the result is. Further, the tire internal temperature was measured immediately after the above test was completed. The results of these investigations are also shown in Table 6.

[0090]

[Table 6]

[0091]

[Table 7]

[0092]

According to the present invention, a safety tire that enables stable running even if the tire is damaged without sacrificing rolling resistance and riding comfort during normal running before the tire is damaged. Can be provided. Further, since abnormal heat generation of the tire can be avoided, it is possible to improve the durability of the tire.

[Brief description of drawings]

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

FIG. 2 is a sectional view in the tire width direction showing another safety tire according to the present invention.

[Explanation of symbols]

1 tire 2 rooms 3 rooms 4 complex 5 bead core 6 carcass 7 belt 8 treads 9 Inner liner layer 10 rims

Claims (17)

[Claims] 1. An inner space of a hollow donut-shaped tire is divided into a plurality of chambers, at least one of the plurality of chambers is filled with gas, and the remaining at least one chamber is dispersed with closed cells in a continuous phase of a polymer. The composite is placed, and the internal pressure of the air bubbles contained in the composite at 25 ° C. is 150 k in absolute pressure.
Pa or more and the expansion start temperature of the composite is 80 to
A safety tire having a temperature of 180 ° C. 2. The safety tire according to claim 1, wherein the partition wall that divides the plurality of chambers is made of a rubber composition containing 50 mass% or more of butyl rubber. 3. The safety tire according to claim 1, wherein the expansion start temperature of the composite is 90 to 160 ° C. 4. The composite A according to claim 3, wherein the expansion start temperature of the composite is 90 to 160 ° C., and the composite B having an expansion start temperature higher than the expansion start temperature of the composite A by 10 ° C. or more. A safety tire including: 5. The safety tire according to claim 4, wherein the weight ratio of the composite B to the composite A is 0.1 to 2.0. 6. The composite according to claim 1, wherein the composite is a pyrolyzable foaming agent, a liquefied fluorinated product of ethane, a liquefied linear aliphatic hydrocarbon having 3 to 8 carbon atoms and a fluorocarbon thereof. At least one selected from liquefied compounds, liquefied branched aliphatic hydrocarbons having 3 to 8 carbon atoms and fluorinated compounds thereof, and liquefied alicyclic hydrocarbons having 3 to 8 carbon atoms and fluorinated compounds thereof. A safety tire, which is a composite obtained by functioning as a foaming agent. 7. The heat-decomposable foaming agent according to claim 6,
A safety tire comprising at least one selected from dinitrosopentamethylenetetramine, azodicarbonamide, paratoluenesulfonylhydrazine and its derivatives, and oxybisbenzenesulfonylhydrazine. 8. The method according to claim 1, wherein
The composite tire is a safety tire characterized by comprising a continuous phase made of resin and closed cells. 9. The method according to claim 1, wherein
The continuous phase of the composite is an acrylonitrile copolymer, acrylic copolymer, vinylidene chloride copolymer, acrylonitrile / styrene resin, polyethylene resin, polypropylene resin, polyester resin, polystyrene / polyethylene copolymer, polyvinyl alcohol resin. And a safety tire comprising at least one of a nylon resin. 10. The composite phase according to claim 1, wherein the continuous phase of the composite is an acrylonitrile polymer, and the acrylonitrile polymer is an acrylonitrile polymer, an acrylonitrile / methacrylonitrile copolymer, or acrylonitrile / methyl. A safety tire comprising at least one selected from a methacrylate copolymer and an acrylonitrile / methacrylonitrile / methyl methacrylate terpolymer. 11. The composite phase according to claim 1, wherein the continuous phase of the composite is an acrylic copolymer, and the acrylic copolymer is a methyl methacrylate resin, a methyl methacrylate / acrylonitrile copolymer, or a methyl copolymer. A safety tire comprising at least one selected from a methacrylate / methacrylonitrile copolymer and a methyl methacrylate / acrylonitrile / methacrylonitrile terpolymer. 12. The composite phase according to claim 1, wherein the continuous phase of the composite comprises a vinylidene chloride copolymer, and the vinylidene chloride copolymer is 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 / Methylmethacrylate copolymer, vinylidene chloride / acrylonitrile / methacrylonitrile / methylmethacrylate copolymer, at least one selected from the safety tires. 13. The composite cell according to claim 1, wherein nitrogen, air, carbon dioxide,
Fluorinated products of ethane, linear aliphatic hydrocarbons having 3 to 8 carbon atoms and fluorinated products thereof, branched aliphatic hydrocarbons having 3 to 8 carbon atoms and fluorinated products thereof, and 3 to 8 carbon atoms
8. A safety tire comprising at least one gas selected from the alicyclic hydrocarbons of 8 and their fluorinated compounds. 14. The safety tire according to claim 1, wherein the internal pressure of the air bubbles contained in the composite at 25 ° C. is 200 kPa or more in absolute pressure. 15. The safety tire according to claim 14, wherein a fluorinated gas is contained at 50 mass% or more among the gas components in the closed cells of the composite. 16. The composite according to claim 1, wherein the composite has a cell content of 80.00% by volume to 98.
A safety tire characterized by being 75% by volume. 17. The method according to claim 1, wherein the composite includes hollow particles obtained by heating and expanding a foamable composition in which a gas component is liquefied and encapsulated in polymer particles. A featured safety tire.