JP2002103929A - Safety tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight safety tire allowing a stable travel even when the tire is broken into a puncture state without sacrificing the rolling resistance and comfortableness in a normal travel. SOLUTION: The inside space of the hollow doughnut-like tire is divided into a plurality of chambers, gas is filled in at least one of the chambers, and a foaming composition is filled into at least one of the remaining chambers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel safety tire which exhibits a new function when the tire is punctured due to an injury or the like, and more particularly to a riding tire during normal running which is maintained at a predetermined internal pressure. The present invention relates to a safety tire that eliminates disadvantages related to comfort and weight reduction.

[0002]

2. Description of the Related Art In a pneumatic tire, for example, in the case of a tire for a passenger car, air is sealed in the tire to reduce the internal pressure to two.
By maintaining the pressure at about 50 to 350 kPa, tension is generated in a tire frame such as a carcass and a belt of the tire, and this tension enables deformation and restoration of the tire with respect to an input to the tire. That is, by maintaining the internal pressure of the tire in a predetermined range, by generating a constant tension in the skeleton of the tire, imparting a load supporting function, increasing the rigidity, such as driving, braking and turning performance, It provides the basic performance required for running the vehicle.

[0003] By the way, if the tire maintained at the predetermined internal pressure receives an injury, air leaks out through the injury and the tire internal pressure decreases to the atmospheric pressure, resulting in a so-called puncture state. Most of the tension generated in the part is lost. Then, the load supporting function and the driving, braking, and turning performances obtained by applying a predetermined internal pressure to the tires are also lost, so that the vehicle equipped with the tires cannot run.

[0004] Therefore, many proposals have been made for safety tires that can run even in a punctured state. For example, as a pneumatic safety tire for automobiles,
Various types have been proposed, such as those having a double wall structure, those having a load supporting device disposed in a tire, and those having a reinforced tire side portion. Among these proposals, the technology actually used is a tire provided with a side reinforcing layer made of relatively hard rubber on the inner surface from the shoulder portion to the bead portion around the sidewall portion of the tire. This type of tire is mainly used as a run-flat tire having an aspect ratio of 60% or less.

However, a technique for adding a side reinforcing layer is as follows.
Since the longitudinal spring constant of the tire is increased by increasing the tire weight by 30 to 40%, there is a disadvantage that the rolling resistance is significantly deteriorated and the riding comfort during normal running before puncturing is reduced.
Therefore, it has a bad influence on the performance, fuel efficiency and environment during normal running, and is therefore a technique that is still poor in versatility.

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

However, the tire cannot withstand local repeated input generated between the tire and the internal support during the so-called run flat running after the puncture, and as a result, the running distance after the puncture is 100 It was limited to about 200 km. In addition, the operation of assembling the tire to the rim after disposing the internal support inside the tire has been a problem in that it is complicated and takes a long time. In this regard, there has been proposed a device in which a difference is provided in the rim diameter between the one end side and the other end side in the width direction of the rim so that the internal support can be easily inserted, but a sufficient effect has not been obtained.

In order to extend the running distance after puncturing 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 ride comfort during normal use, so it is not practical to employ this method. Furthermore, the addition of the skeleton material causes an increase in the weight of the tire, which hinders the reduction in the weight of the tire required for improving the fuel efficiency of automobiles.

Further, a tire in which closed-cell foam is filled into an internal cavity of an assembly of a tire and a rim to be attached thereto is disclosed in, for example, JP-A-6-127207 and JP-A-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, motorcycle tires and bicycle tires.
Therefore, its application to tires for passenger cars, tires for trucks and buses, and particularly to tires that emphasize rolling resistance and ride comfort has been unknown. Since all foams have a low expansion ratio, they have a large weight in place of the composite having bubbles, and inevitable deterioration in vibration riding comfort and fuel efficiency, and the inside of the closed cells is at atmospheric pressure. Therefore, it was not functionally sufficient to replace the high pressure air of the conventional tire.

[0010] Further, Japanese Patent No. 2987076 discloses a puncture-free tire in which a foam filler is inserted into the inner peripheral portion. In addition to the disadvantage that the pressure of the foam is extremely close to the atmospheric pressure, the foamless tire has a disadvantage. Is urethane-based, so that the energy loss due to the intermolecular hydrogen bonding of the urethane group is large and the self-heating property is high. Therefore, when the urethane foam is filled in the tire, the foam is heated by repeated deformation during rolling of the tire, and the durability is greatly reduced. In addition, since a material that is difficult to form air bubbles independently is used, air bubbles are easily communicated and it is difficult to retain gas, and a desired tire internal pressure (load supporting ability or deflection suppressing ability, the same applies hereinafter). There are disadvantages that cannot be obtained.

Further, Japanese Patent Application Laid-Open No. 48-70002 discloses that the outer periphery of a multi-cellular body mainly composed of closed cells is integrally wrapped with a 0.5 to 3 mm thick outer coating film of rubber, synthetic resin or the like. A puncture-less tire has been proposed in which a large number of sealed inflated pressure bubbles are filled in a tire and the tire is maintained at a specified internal pressure. In this technology, the amount of the foaming agent in the closed-cell body forming and blending raw material to be expanded pressure bubbles is at least equal to or greater than the tire inner volume in order to make the pressure inside the cells of the foam higher than normal pressure. The compounding amount of the foaming agent that generates gas is set, thereby aiming at the same performance as at least a normal pneumatic tire.

The technology described in Japanese Patent Application Laid-Open No. 48-70002 does not provide a new function required for running when the tire falls into a punctured state, similarly to the tire filled with the foam. In addition, since the internal pressure was given by the foam, it was inevitable that the tire performance during normal running, which is not a punctured state, would be deteriorated as compared with a normal pneumatic tire.

[0013]

SUMMARY OF THE INVENTION Therefore, the present invention
The purpose of the present invention is to propose a lightweight safety tire that enables stable running even in the event of a puncture caused by tire damage without sacrificing rolling resistance and riding comfort during normal running. I do.

[0014]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and found that when the internal pressure of the tire is reduced due to an injury or the like, the puncture state triggers the internal pressure of the tire. The present inventors have found that it is extremely effective to newly develop a substitute function for the leaked gas, and have completed the present invention. That is, the gist configuration of the present invention is as follows.

(1) The inner space of a hollow donut-shaped tire is divided into a plurality of chambers, and at least one of the plurality of chambers is filled with a gas and at least one of the remaining chambers is filled with a foamable composition. A safety tire characterized in that:

(2) The safety tire according to the above (1), wherein the partition partitioning the plurality of chambers is made of a rubber composition containing 50 mass% or more of butyl rubber.

(3) A safety tire according to the above (1) or (2), wherein the foamable composition is a single substance of a thermally decomposable foaming agent.

(4) The safety tire according to (1) or (2), wherein the foamable composition comprises a polymer and a foaming agent.

(5) The safety tire according to (4), wherein the foamable composition is obtained by encapsulating a foaming agent in particles having a polymer as a continuous phase.

(6) The safety tire according to the above (4), wherein the foamable composition is obtained by dispersing a foaming agent in a polymer.

(7) The safety tire according to any one of the above (4) to (6), wherein the foaming agent is a pyrolytic foaming agent.

(8) The above (3) to (7).
Wherein the thermally decomposable blowing agent is at least one selected from the group consisting of dinitrosopentamethylenetetramine, azodicarbonamide, paratoluenesulfonylhydrazine and derivatives thereof, and oxybisbenzenesulfonylhydrazine. Safety tire.

(9) In any one of the above (4) to (7), the blowing agent may be a fluorinated product of nitrogen, air or ethane, a linear aliphatic hydrocarbon having 3 to 8 carbon atoms and a fluorinated product thereof. It is at least one selected from the group consisting of a branched aliphatic hydrocarbon having 3 to 8 carbon atoms and a fluorinated product thereof, and an alicyclic hydrocarbon having 3 to 8 carbon atoms and a fluorinated product thereof. Safety tire.

(10) In any one of the above (4) to (9), the polymer is a polyvinyl alcohol resin, a nylon resin, an acrylonitrile polymer, an acrylic polymer,
Vinylidene chloride polymer, acrylonitrile / styrene resin, polyethylene resin, polypropylene resin, polyester resin and polystyrene / polyethylene copolymer,
A safety tire comprising at least one member selected from the group consisting of butyl rubber.

(11) In any one of the above (4) to (10), the polymer is a nylon resin, and the nylon resin is nylon 6, nylon 11, nylon 12, or nylon 6/66 copolymer. And at least one selected from nylon 6/12 copolymer.

(12) In any one of the above (4) to (10), the polymer comprises an acrylonitrile polymer, and the acrylonitrile polymer is an acrylonitrile polymer, an acrylonitrile / methyl methacrylate copolymer, an acrylonitrile / Methacrylonitrile copolymer and at least one selected from acrylonitrile / methyl methacrylate / methacrylonitrile terpolymer
A safety tire characterized by being a seed.

(13) In any one of the above (4) to (10), the polymer comprises an acrylic polymer, and the acrylic polymer is a methyl methacrylate resin, a methyl methacrylate / acrylonitrile copolymer, A safety tire comprising at least one selected from methacrylate / methacrylonitrile copolymer and methyl methacrylate / acrylonitrile / methacrylonitrile copolymer.

(14) In any one of the above (4) to (10), the polymer is a vinylidene chloride polymer, and the vinylidene chloride polymer is a vinylidene chloride / acrylonitrile copolymer, a vinylidene chloride / vinylidene chloride polymer. Methacrylonitrile copolymer, vinylidene chloride / methyl methacrylate copolymer, vinylidene chloride / acrylonitrile / methacrylonitrile copolymer, vinylidene chloride / acrylonitrile / methyl methacrylate copolymer, vinylidene chloride / methacrylonitrile / methyl methacrylate copolymer, chloride A safety tire comprising at least one member selected from the group consisting of vinylidene / acrylonitrile / methacrylonitrile / methyl methacrylate copolymer.

(15) In any one of the above (4) to (14), the gas permeability coefficient of the polymer at 30 ° C. is 300 × 1.
^0-12 (cc · cm / cm ² · s · cmHg) or less.

(16) A safety tire according to any one of the above (1) to (15), wherein at least one auxiliary layer of a foamable composition is provided.

(17) The safety tire according to the above (16), wherein the auxiliary layer constitutes an inner liner layer of the tire.

(18) The safety tire according to the above (16) or (17), wherein the auxiliary layer is provided adjacent to the carcass of the tire.

(19) The safety tire according to any one of the above (16) to (18), wherein the auxiliary layer is provided adjacent to the partition wall.

(20) The safety tire according to any one of the above (1) to (19), wherein the foamable composition forms a composite comprising a continuous phase and bubbles after foaming.

(21) The safety tire according to the above (20), wherein the cells of the composite are closed cells.

(22) In the above (20) or (21), the gas existing in the bubbles of the composite is a fluorinated product of ethane, a linear aliphatic hydrocarbon having 3 to 8 carbon atoms and a fluorinated product thereof. It is at least one selected from the group consisting of a branched aliphatic hydrocarbon having 3 to 8 carbon atoms and a fluorinated product thereof, an alicyclic hydrocarbon having 3 to 8 carbon atoms and a fluorinated product thereof, nitrogen, and air. Features safety tires.

(23) In any one of the above (20) to (22), the continuous phase of the composite comprises a polyvinyl alcohol resin, a nylon resin, an acrylonitrile polymer, an acrylic polymer, a vinylidene chloride polymer, Acrylonitrile /
A safety tire comprising at least one of styrene resin, polyethylene resin, polypropylene resin, polyester resin, polystyrene / polyethylene copolymer, and butyl rubber.

(24) In any one of the above (20) to (23), the continuous phase of the composite comprises a nylon resin, and the nylon resin is nylon 6, nylon 11, nylon 1
2. A safety tire characterized in that it is at least one selected from nylon 6/66 copolymer and nylon 6/12 copolymer.

(25) In any one of the above (20) to (23), the continuous phase of the composite comprises an acrylonitrile-based polymer, and the acrylonitrile-based polymer is an acrylonitrile polymer, an acrylonitrile / methyl methacrylate copolymer. A safety tire characterized in that it is at least one selected from acrylonitrile / methacrylonitrile copolymer and acrylonitrile / methyl methacrylate / methacrylonitrile terpolymer.

(26) In any one of the above (20) to (23), the continuous phase of the composite comprises an acrylic polymer, and the acrylic polymer is a methyl methacrylate resin, a methyl methacrylate / acrylonitrile copolymer. And a methyl methacrylate / methacrylonitrile copolymer and at least one selected from a methyl methacrylate / acrylonitrile / methacrylonitrile copolymer.

(27) In any one of the above (20) to (23), the continuous phase of the composite comprises a vinylidene chloride polymer, and the vinylidene chloride polymer is a vinylidene chloride / acrylonitrile copolymer, Vinylidene / methacrylonitrile copolymer, vinylidene chloride / methyl methacrylate copolymer, vinylidene chloride / acrylonitrile /
At least one selected from methacrylonitrile copolymer, vinylidene chloride / acrylonitrile / methyl methacrylate copolymer, vinylidene chloride / methacrylonitrile / methyl methacrylate copolymer, vinylidene chloride / acrylonitrile / methacrylonitrile / methyl methacrylate copolymer A safety tire characterized by the following.

(28) In any one of the above (20) to (27), the gas permeability coefficient of the continuous phase of the composite at 30 ° C. is 3
00 × 10 ^-12 (cc · cm / cm ² · s · cmH
g) A safety tire characterized by the following.

(29) A safety tire according to any one of the above (1) to (28), wherein a side reinforcing layer made of hard rubber is arranged inside the sidewall portion of the tire.

(30) In any one of the above (1) to (29), the partition wall has a gas permeability coefficient at 30 ° C. of 300 × 10
^-12 (cc · cm / cm ² · s · cmHg) or less.

(31) In any one of the above (1) to (30), the partition wall has a gas permeability coefficient at 30 ° C. of 20 × 10
^-12 (cc · cm / cm ² · s · cmHg) or less.

(32) In any one of the above (1) to (31), the partition wall has a gas permeability coefficient at 30 ° C. of 2 × 10
^-12 (cc · cm / cm ² · s · cmHg) or less.

[0047]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A safety tire according to the present invention will be described below with reference to FIG. That is, the illustrated safety tire includes a tire 1 and a partition 2 filled with a foamable composition therein. Note that the structure of the tire 1 is not particularly limited as long as the tire 1 generally follows various kinds of automobile tires, for example, passenger car tires. For example, the illustrated tire is a general automobile tire, and a belt 5 and a tread 6 are arranged on a crown portion of a carcass 4 extending in a toroidal shape between a pair of bead cores 3 in a radially outward direction of the tire. . In the drawings, reference numeral 7 denotes an inner liner layer and reference numeral 8 denotes a rim, and reference numeral 9 denotes an auxiliary layer provided on the radially back side of the carcass crown portion.

The partition wall 2 is preferably made of a rubber composition containing butyl rubber of 50 mass% or more and has high elasticity. The inside of the partition wall 2 is filled with a foaming composition. For example, as shown in FIG. It is arranged along the rim 8. At the time of normal use adjusted to a predetermined air pressure, it is preferable that the partition wall 2 be brought into close contact with the rim 8 so as not to contact the inner surface of the tire. Even if the tire receives a large input and deforms so much that the partition 2 and the inner surface of the tire come into contact with each other, the partition 2 is flexible, so that it does not cause a large impact and the ride comfort during normal use is reduced. It will not be inhibited.

The inside of the partition wall 2 is filled with a foaming composition that starts foaming at a predetermined temperature, and when a puncture occurs due to damage during use of the tire, the foaming composition is filled with the foaming composition. It is characterized by foaming to form a composite inside the tire.

That is, when the tire is damaged during normal use of the tire, the internal pressure of the tire gradually or rapidly decreases. When the internal pressure of the tire decreases, the internal temperature increases due to the self-heating of the tire. When the internal temperature of the tire reaches a predetermined temperature, the expandable composition in the partition wall 2 expands by foaming. When the inflation is completed, as shown in FIG. 2, a complex 20 sufficient to support the load applied to the tire is generated inside the tire 1, and a predetermined internal pressure is applied to the tire by the complex 20 so that the tire 1 A structure capable of generating tension in a tire skeleton such as a carcass and a belt is realized. As a result, the predetermined internal pressure is again applied to the tire that has fallen into a punctured state, so that healthy running can be performed even after the tire is damaged.

Here, the temperature at which the foamable composition in the partition walls 2 starts to expand by foaming must be set in a temperature range that exceeds the temperature range in normal use. May be selected as appropriate depending on the type of the material and the use conditions. For example, the use temperature range of a summer tire is higher than that of a studless tire (a winter tire), and thus the expansion start temperature needs to be set higher.

Since the rim assembling operation of the tire is performed at normal temperature and normal pressure, the foamable composition in the partition 2 disposed inside the tire does not foam. Therefore, first, a gas is filled until the pressure in the partition reaches 200 kPa at an absolute internal pressure (hereinafter, the pressure is also indicated by the absolute pressure), and then the gas is further increased to 300 kPa between the tire inner surface and the partition outer surface. Fill until ready. Then, the partition is compressed and the internal pressure of the partition in the tire is reduced to about 30 as a result.
0 kPa. When the tire is injured and the air inside the tire is dissipated, the partition wall expands toward the tire inner surface and the internal pressure becomes about 200 kPa again, and the vehicle temporarily runs under the load supported by the partition wall 2. Will be done. However, from normal running at an internal pressure of 300 kPa,
When the vehicle shifts to running under a reduced pressure of 0 kPa, the amount of flexure of the tire increases significantly compared to the normal running, so that the tire itself generates heat and the internal temperature of the tire rapidly rises, so that foaming of the foamable composition starts instantaneously. Due to the expansion, the tire internal pressure can be restored to about 300 kPa again. That is, an increase in temperature due to an increase in the amount of tire deflection accompanying a decrease in the tire internal pressure triggers the start of foaming and consequently the expansion of the partition walls.

The diameter of the partition 2 is preferably equal to or less than the diameter of the rim 8. Because, due to the weight of the foamable composition and the partition walls, during rotation of the tire, the partition walls 2 bulge outward due to centrifugal force, preventing the inner surface of the tire from being rubbed or rubbed, and providing excellent ride comfort. This is because it is advantageous.

As described above, it is preferable to apply an internal pressure to the inside of the partition. First, by applying the internal pressure to the inside of the partition, the partition can be fitted to the rim to prevent unnecessary rotation during normal use, and the tire can be prevented from being completely crushed when the internal pressure of the tire is dissipated.
Next, filling the space between the inner surface of the tire and the outer surface of the partition further with the gas until the target internal pressure is reached is very effective in avoiding the partition being damaged when the tire is injured because the partition can be compressed. become.

Here, the gas filled in the partition is preferably a gas containing no oxygen. That is, when the foamable composition filled in the partition walls may be charged with static electricity due to friction, and when a resin in which a gas having about 3 to 8 carbon atoms is liquefied and sealed under pressure is used as the foamable composition, This is because, when the gas leaks out of the resin, if there is oxygen, there is a risk of explosion due to a spark. Therefore, for example, it is preferable that the gas to be liquefied and sealed be fluorinated, the gas to be filled in the partition be a fluorinated gas, or be filled with nitrogen or the like.

By the way, since the partition wall is rich in elasticity, it is easy to assemble the rim, so that it is free from long and complicated work such as conventional load supports made of resin or rubber. Performance can be improved. There is no need to use special rims, and conventional general-purpose rims can be applied. Furthermore, since the composite is generated in the partition wall, the weight is light, so that fuel saving, improvement in riding comfort and maneuverability can be expected.

Next, as the foamable composition, a thermally decomposable foaming agent alone, a composition obtained by blending a polymer and a foaming agent, especially a foaming agent encapsulated in particles having a polymer as a continuous phase. Or a dispersion of a blowing agent in a polymer is advantageously suitable.

That is, when a simple substance of a thermally decomposable foaming agent is used as the foamable composition, after the foaming, the inside of the partition is filled with gas, and the embodiment becomes like a conventional tire with a partition. Further, when a foaming composition comprising a combination of a polymer and a foaming agent is used, a composite comprising a continuous phase of the polymer and cells, preferably closed cells, is obtained.

In particular, when the internal pressure applying means is used after the tire is damaged, it is preferable to form a composite composed of a continuous phase of a polymer and closed cells in a partition wall arranged inside the tire. Such a composite has closed cells in which individual cells are isolated surrounded by partition walls, and has a cell content of 80.00% by volume to 98.7% by volume in the composite.
It is preferably 5% by volume. Because, when the bubble content is less than 80.00% by volume, when the composite is deformed inside the tire, stress sporadically concentrates in a continuous phase portion between the bubbles, and cracks are easily generated in the continuous phase, and repeated. The durability of the composite to deformation is significantly reduced. Also,
If the bubble content exceeds 98.75% by volume, the durability of the composite against repeated deformation may be significantly reduced.

Here, the bubble content is a percentage of the volume of the bubble with respect to the volume of the composite disposed in the partition, and can be specifically calculated by the following equation. . Bubble content = [1- {Used volume of resin or composition constituting composite / (Tire inner volume−Volume of partition wall)}] × 100 where the used volume of resin or composition constituting composite is Refers to the volume of the composition before the formation of closed cells by foaming by heating or the like, and is a volume value that does not include the closed cell volume.

The used volume of the resin or the composition constituting the composite is determined, for example, by weighing the composition in advance into a container having a 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 measuring cylinder under atmospheric pressure, and the measuring cylinder is immersed in an ultrasonic water bath to give vibration, The method of integrating the volume values in a state where the packing between the material particles is stable is straightforward. Further, in this method, since the bulk specific gravity of the composition particles can be calculated, the target weight of the composition particles corresponding to the target volume can be calculated. Therefore, by weighing the partition walls in advance and measuring the weight increase due to the arrangement of the composition particles, it is possible to adjust to the target volume used. Therefore, when the resin or the composition is in the form of particles, the used volume means the sum of the total volume of the particles and the total volume of the voids between the composition particles.

Further, at 25 ° C. of closed cells in the composite
Internal pressure at 150 kPa or more, preferably 200 kPa
It is preferable to be Pa or more. If the internal pressure of the closed cells at 25 ° C. is less than 150 kPa, the deflection of the composite becomes large, and the amount of repeated deformation during rolling of the tire becomes large, so that the performance when the tire is damaged and running is insufficient. Here, the internal pressure value is the normal pressure (atmospheric pressure) of 100 kPa.
Shall be expressed as That is, the internal pressure is 200 kP
a indicates that the pressure is twice the atmospheric pressure.

Here, the pressure in the bubble can be calculated by the following equation (A) based on the following definition. Bubble pressure (kPa) = [(Wt / ρs) / Vt] 101.325 (A) where, Wt: weight of composite filled in tire Vt: (internal volume of tire used for filling ) − (Volume of partition wall) ρs: Specific gravity of the composite sampled from the tire at atmospheric pressure, ρs = Ws / Vs, where Vs: atmospheric pressure of the composite sampled from the tire Ws: weight of composite sampled from tire

By disposing a partition wall having an expanding force by such a composite in the tire, a predetermined internal pressure is applied to the tire, and an indispensable internal pressure is applied to the tire. A structure capable of generating tension in the tire frame portion is realized.

When the tire in which the composite is formed inside is further damaged, the partition wall and a part of the composite are damaged on the inner surface of the tire near the injury, and some of the damaged portions are independent. The gas in the bubbles may escape to the outside of the tire. However, if this phenomenon is compared to a conventional pneumatic tire, the internal pressure drops only in a very small part of the area, so that the tire does not lose its case tension due to partial damage of the composite, There is no puncture in the conventional pneumatic tire. Furthermore, the probability of damage to the composite due to tire trauma is extremely low, and even if it is damaged, the area is extremely limited, so the tire internal pressure given by the composite may be reduced enough to impair tire function. I can't get it.

In addition, the vicinity of the damaged closed cell drops to the atmospheric pressure, but the closed cells in the surrounding area are, for example, 15 atmospheres.
As a result of instantaneous expansion due to having an internal pressure of 0 kPa or more, the area of the damaged closed cell is contracted and the damaged portion is instantly closed, and so-called self-healing becomes possible.

Here, in order to apply a predetermined tire internal pressure by the composite, in consideration of the breakage of the partition wall, the gas sealed at a predetermined pressure in the closed cells in the composite must not leak from the bubbles to the outside of the composite. In other words, it is important that the continuous phase of the composite has a property that the gas does not easily permeate. That is, the continuous phase of the composite is made of a material having low gas permeability, specifically, polyvinyl alcohol resin, nylon resin, acrylonitrile polymer, acrylic polymer, vinylidene chloride polymer, acrylonitrile / styrene. Resin, polyethylene resin, polypropylene resin,
At least one selected from the group consisting of polyester resin, polystyrene / polyethylene copolymer, and butyl rubber
It is essential that they consist of seeds. Any of these materials can be relatively easily composited in a tire,
It has flexibility with respect to input due to tire deformation.

In particular, it is preferable to use any one of a nylon resin, an acrylonitrile polymer, a polyvinyl alcohol resin, an acrylic polymer and a vinylidene chloride polymer. Furthermore, as a nylon resin,
Nylon 6, Nylon 11, Nylon 12, Nylon 6
Acrylonitrile polymer, acrylonitrile / methyl methacrylate copolymer, acrylonitrile / methacrylonitrile copolymer, and acrylonitrile / acrylonitrile-based polymer. At least one selected from methyl methacrylate / methacrylonitrile terpolymer, and acrylic polymers include methyl methacrylate resin, methyl methacrylate / acrylonitrile copolymer, methyl methacrylate /
At least one selected from methacrylonitrile copolymer and methyl methacrylate / acrylonitrile / methacrylonitrile copolymer, and vinylidene chloride-based polymers include vinylidene chloride / acrylonitrile copolymer, vinylidene chloride / methacrylonitrile copolymer Copolymer, vinylidene chloride / methyl methacrylate copolymer, vinylidene chloride / acrylonitrile / methacrylonitrile copolymer, vinylidene chloride / acrylonitrile / methyl methacrylate copolymer, vinylidene chloride / methacrylonitrile / methyl methacrylate copolymer,
At least one selected from vinylidene chloride / acrylonitrile / methacrylonitrile / methyl methacrylate copolymer is advantageously suitable.

The continuous phase of the composite obtained using the above materials has a gas permeability coefficient at 30 ° C. of 300 × 10 3
^-12 (cc · cm / cm ² · s · cmHg) or less, preferably a gas permeability coefficient at 30 ° C of 20 × 10
⁻¹² (cc · cm / cm ² · s · cmHg) or less, more preferably a gas permeability coefficient at 30 ° C. of 2 × 10
^{-1 2} that ^{(cc · cm / cm 2 ·} s · cmHg) or less is recommended. The smaller the gas permeability coefficient of the continuous phase of the composite, the more preferable it is because the gaseous gas can be retained in the composite and the traveling distance after puncturing can be increased.

The gas filled in the closed cells of the composite includes nitrogen, air, fluorinated ethane, linear aliphatic hydrocarbons having 3 to 8 carbon atoms and fluorinated products thereof, and 3 carbon atoms. To 8 branched aliphatic hydrocarbons and fluorinated products thereof, and at least one member selected from the group consisting of alicyclic hydrocarbons having 3 to 8 carbon atoms and fluorinated products thereof.
Use seeds. That is, as a foaming agent for obtaining a composite, a pyrolytic foaming agent, a fluorinated product of nitrogen, air, and ethane, a linear aliphatic hydrocarbon having 3 to 8 carbon atoms and its fluorinated product, Examples thereof include those obtained by liquefying a branched aliphatic hydrocarbon having 3 to 8 and a fluorinated product thereof, and an alicyclic hydrocarbon having 3 to 8 carbon atoms and a fluorinated product thereof.

Many of the pyrolytic foaming agents have a characteristic of generating nitrogen by thermal decomposition, and the composite obtained by appropriately controlling the reaction has nitrogen in the bubbles. As the thermally decomposable blowing 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 pyrolytic foaming agents with the resin constituting the molten matrix.

Further, when polymerizing the resin constituting the continuous phase, fluorinated ethane and C 3 -C 8
Linear aliphatic hydrocarbons and fluorinated products thereof, C 3 to C 8 branched aliphatic hydrocarbons and fluorinated products thereof, and C 3 to C 8 alicyclic hydrocarbons and fluorinated products thereof, Specifically, propane, butane, pentane, hexane, heptane, octane, cyclopropane, cyclobutane, cyclopentane, cyclohexane,
There is also a method of liquefying cycloheptane and cyclooctane and dispersing them in a reaction solvent, and performing emulsion polymerization.
This makes it possible to obtain a material in which gas components such as propane, butane, pentane, hexane, heptane, octane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane and cyclooctane are sealed in a liquid state with the resin, When this is filled into the partition wall and a composite is formed due to an increase in the tire internal temperature at the time of puncturing, the bubble gas is propane, butane, pentane, hexane, heptane, octane, cyclopropane, cyclobutane, cyclopentane, cyclohexane,
It becomes cycloheptane and cyclooctane. The isomers of butane, pentane and hexane include isobutane, isopentane, neopentane, 2-methylpentane, 2,2-dimethylbutane, methylhexanes, dimethylpentanes, trimethylbutane, methylheptane, dimethylhexanes and Trimethylpentanes and the like can be mentioned. Furthermore, resin particles containing a liquefied gas such as propane, butane, pentane, and hexane may be filled in the partition wall together with a melt of the resin forming the continuous phase of the composite.

The safety tire of the present invention is characterized in that the foamable composition in the partition wall particularly arranged inside the tire forms a composite at the time of puncture and serves as a load support for the tire. The realization of such a safety tire largely depends on the following new manufacturing method. Hereinafter, the manufacturing method will be specifically described.

The first method is to fill a predetermined amount of the foamable composition into the inside of the partition wall, and then, when assembling the tire and the rim,
The partition is located in the tire.

The second technique is to melt a material to be a continuous phase of a composite, add a foaming agent (including a foaming aid) to the inside, fill the inside of a partition wall, and then incorporate a tire and a rim. Occasionally, the partition is placed in the tire.

A third technique is to fill the inside of a partition with a liquid particle of butane, propane, pentane or the like in polymer particles, such as Expancel (trademark), and then mount the tire and rim. When incorporated, the septum is placed in the tire.

A fourth technique is to use butane, propane, or the like in polymer particles, such as Expancel (trade name).
The liquefied pentane or the like is injected into the partition together with the melt of the raw material to be the continuous phase of the composite, and the partition is disposed in the tire when the tire and rim are assembled.

The continuous phase of the composite is a combination of at least one polymer selected from polyvinyl alcohol resin, acrylic polymer, acrylonitrile polymer, vinylidene chloride polymer, nylon resin and butyl rubber. Can be. Further, as a foaming agent, at least one selected from dinitrosopentamethylenetetramine (DPT), azodicarbonamide (ADCA), paratoluenesulfonylhydrazine (TSH) and its derivatives, and oxybisbenzenesulfonylhydrazine (OBSH) is used. The purpose can be achieved by using them together.

Further, the mode of the partition will be described below. That is, a nylon resin having a melting point of 170 to 230 ° C. and an elastomer component containing a halide of isobutylene paramethylstyrene copolymer are gelled at a partition ratio of 50 to 95%.
And a thermoplastic elastomer composition dynamically vulcanized. This is because by using a nylon resin as the continuous phase, the gas permeability becomes extremely good, so that the function as a partition can be enhanced. Also,
The thermoplastic elastomer composition obtained by dynamically vulcanizing an elastomer component containing a halide of isobutylene paramethylstyrene copolymer to a gelation ratio of 50 to 95% provides high flexibility, heat resistance and durability. Excellent partition walls are obtained.

The gelation ratio was determined by soxhlet extraction of the pelletized mixture after biaxial kneading with acetone in a water bath for 8 hours, and the residue was further n-h-extracted for 8 hours.
By Soxhlet extraction with hexane, the unvulcanized elastomer component is extracted with a solvent, and acetone and n
-The value obtained by measuring the weight of the hexane extract after drying the solvent, and calculating by the following formula. Gelation ratio (%) = [weight of all formulations-{(extracted amount of acetone + extracted amount of n-hexane) -amount of stearic acid}] / weight of all formulations × 100

In this partition, the gas permeability coefficient at 30 ° C. is 300 × 10 ⁻¹² (cc · cm / cm ² · s · c).
mHg) or less, preferably 20 × 10 ⁻¹² (cc · c)
m / cm ² · s · cmHg) or less, more preferably 2 ×
It is recommended that it be 10 ⁻¹² (cc · cm / cm ² · s · cmHg) or less. Because, even when the gas permeability of the continuous phase of the composite is high, if the gas permeability of the partition is low, the gas bubbles in the composite are less likely to leak to the outside of the partition, and the internal pressure of the tire is maintained. This is because it is advantageous. That is, the gas permeability of the partition is a factor that directly determines the pressure retention of the partition as a pressure vessel.

Further, in the safety tire of the present invention, as shown in FIG. 1, it is advantageous to provide at least one auxiliary layer 9 made of a foamable composition in order to prevent the damage of the tire from reaching the partition walls. It is. That is, in addition to the example shown in FIG. 1, the auxiliary layer can be provided as the above-described inner liner layer or can be provided adjacent to the partition wall. In addition, it can function as a buffer layer for injury.

That is, a sheet of an unvulcanized rubber composition containing a foaming agent is arranged between the carcass and the inner liner layer during tire molding, and the sheet is foamed during tire vulcanization. Alternatively, the auxiliary layer can be disposed on the inner surface of the tire by a method of blending a foaming agent with the inner liner rubber and foaming the inner liner rubber layer itself during vulcanization of the tire.

FIG. 1 shows the application of the present invention to a general-purpose tire. For example, as shown in FIG. 3 and FIG.
The present invention can be applied to a tire having a structure more suitable for run-flat running. That is, the tire shown in FIGS. 3 and 4 is provided with the side reinforcing layer 10 made of hard rubber particularly inside the sidewall portion of the tire.
The side part is reinforced.

[0085]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1 or FIG. 3, a tire of size 185 / 70R14 and a size of 5.5J ×
14 rims were prepared, and tubes (partitions) filled with foamable compositions having various specifications shown in Tables 1 and 2 were arranged inside the tires when the tires and the rims were assembled, whereby a safety tire for passenger cars was obtained. A rim assembly was prototyped. here,
The tire 1 follows the general structure of the type and size of the tire. The types of foamable compositions in Tables 1 and 2 are as shown in Table 3. Similarly, the rubber type of the auxiliary layer is shown in Table 4, and the compounding of the side reinforcing rubber is shown in Table 5,
Each is as shown.

In Tables 1 and 2, Comparative Example 1 is an example serving as a reference for the entire evaluation tire. Similarly, Comparative Example 2 is a comparative object of Invention Example 1, Comparative Example 3 is a comparative object of Invention Example 2, and
Comparative Example 4 is Comparative Example of Invention Example 3, Comparative Examples 10 to 16 and Comparative Example 5 is Comparative Example of Invention Examples 4 to 9.

Further, the expansion start temperature in Tables 1 and 2 is the temperature at the time when the amount of expansion displacement is measured under the following conditions. Equipment: Nishizawa PERKIN-ELMER 7Series
(ThermalAnalysis System) Measurement conditions: heating rate 10 ° C./min, measurement start temperature 25
° C, Measurement end temperature 200 ° C, Physical quantity measured: Measures the amount of expansion displacement due to heating

For each of the tires thus obtained, the riding comfort and rolling resistance during normal use were examined. That is, the ride comfort was determined by mounting a prototype tire on a 2000 cc class passenger car, performing a feeling test on ride comfort by two specialized drivers, performing an evaluation out of 10 points, and calculating the average. The greater this value, the better the ride comfort.

The rolling resistance was measured by the coasting method. The tire internal pressure (absolute internal pressure) was 270 kPa, the load was JIS 100% load, and the coasting start temperature was 100.
The test was performed under the condition of km, and the work amount corresponding to the rolling resistance of the tire was determined from the speed drop curve of the coasting drum. The measurement result is 100% for the tire of Comparative Example 1.
It was shown by the index when The smaller this number is,
This indicates that the rolling resistance is small.

Further, each tire is mounted on a 2000 cc class passenger car, and then the tire has a diameter of 3 mm and a length of:
Injury was caused by penetrating the tread from the outside of the tire tread with a 3 cm nail, and then a load equivalent to 4 passengers was applied, and the test course was run at 90 km / h to run a maximum of 500 km. , And the possible running distance was measured. The results of these surveys are shown in Tables 1 and 2.

[0091]

[Table 1]

[0092]

[Table 2]

[0093]

[Table 3]

[0094]

[Table 4]

[0095]

[Table 5]

[0096]

According to the present invention, stable running can be achieved even in the event of a puncture after tire damage without sacrificing rolling resistance and ride comfort during normal running before tire damage. A possible safety tire can be provided.

[Brief description of the drawings]

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

FIG. 2 is a sectional view in the tire width direction showing a state after puncturing of a safety tire according to the present invention.

FIG. 3 is a sectional view in the tire width direction showing another safety tire according to the present invention.

FIG. 4 is a sectional view in the tire width direction showing another safety tire according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tire 2 Partition wall 3 Bead core 4 Carcass 5 Belt 6 Tread 7 Inner liner layer 8 Rim 9 Auxiliary layer 10 Side reinforcing layer 20 Composite

Claims (32)

[Claims] An inner space of a hollow donut-shaped tire is divided into a plurality of chambers, and at least one of the plurality of chambers is filled with a gas, and at least one of the remaining chambers is filled with a foamable composition. Safety tire characterized by the following. 2. The safety tire according to claim 1, wherein the partition partitioning 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 foamable composition is a single thermally decomposable foaming agent. 4. The safety tire according to claim 1, wherein the foamable composition comprises a polymer and a foaming agent. 5. The safety tire according to claim 4, wherein the foamable composition is obtained by encapsulating a foaming agent in particles having a polymer as a continuous phase. 6. The safety tire according to claim 4, wherein the foamable composition is obtained by dispersing a foaming agent in a polymer. 7. The method according to claim 4, wherein
A safety tire, wherein the foaming agent is a pyrolytic foaming agent. 8. The method of claim 3, wherein the pyrolytic blowing agent is selected from the group consisting of dinitrosopentamethylenetetramine, azodicarbonamide, paratoluenesulfonylhydrazine and derivatives thereof, and oxybisbenzenesulfonylhydrazine. A safety tire comprising at least one kind. 9. The method according to claim 4, wherein
The blowing agent is nitrogen, air, a fluorinated ethane, a linear aliphatic hydrocarbon having 3 to 8 carbon atoms and a fluorinated product thereof,
It is at least one selected from the group consisting of a branched aliphatic hydrocarbon having 3 to 8 carbon atoms and a fluorinated product thereof, and an alicyclic hydrocarbon having 3 to 8 carbon atoms and a fluorinated product thereof. Safety tire. 10. The polymer according to claim 4, wherein the polymer is a polyvinyl alcohol resin, a nylon resin, an acrylonitrile polymer, an acrylic polymer,
Vinylidene chloride polymer, acrylonitrile / styrene resin, polyethylene resin, polypropylene resin, polyester resin and polystyrene / polyethylene copolymer,
A safety tire comprising at least one member selected from the group consisting of butyl rubber. 11. The method according to claim 4, wherein the polymer comprises a nylon resin, and the nylon resin comprises nylon 6, nylon 11, nylon 12, nylon 6/66 copolymer and nylon 6/66. A safety tire comprising at least one member selected from the group consisting of 12 copolymers. 12. The method according to claim 4, wherein the polymer is an acrylonitrile-based polymer, and the acrylonitrile-based polymer is an acrylonitrile polymer, an acrylonitrile / methyl methacrylate copolymer, or an acrylonitrile / methacrylonitrile copolymer. At least one selected from a polymer and an acrylonitrile / methyl methacrylate / methacrylonitrile terpolymer
A safety tire characterized by being a seed. 13. The method according to claim 4, wherein the polymer comprises an acrylic polymer, and the acrylic polymer is a methyl methacrylate resin, a methyl methacrylate / acrylonitrile copolymer, a methyl methacrylate / methacrylonitrile. A safety tire characterized by being at least one selected from a copolymer and a methyl methacrylate / acrylonitrile / methacrylonitrile copolymer. 14. The polymer according to claim 4, wherein the polymer comprises a vinylidene chloride polymer, wherein the vinylidene chloride polymer is a vinylidene chloride / acrylonitrile copolymer, a vinylidene chloride / methacrylonitrile copolymer. Copolymer, vinylidene chloride / methyl methacrylate copolymer, vinylidene chloride / acrylonitrile / methacrylonitrile copolymer, vinylidene chloride / acrylonitrile / methyl methacrylate copolymer, vinylidene chloride / methacrylonitrile / methyl methacrylate copolymer, vinylidene chloride / acrylonitrile / A safety tire characterized in that it is at least one selected from methacrylonitrile / methyl methacrylate copolymer. 15. The polymer according to claim 4, wherein the gas permeability coefficient of the polymer at 30 ° C. is 300 × 1.
^0-12 (cc · cm / cm ² · s · cmHg) or less. 16. A safety tire according to claim 1, wherein at least one auxiliary layer made of a foamable composition is provided. 17. The safety tire according to claim 16, wherein the auxiliary layer constitutes an inner liner layer of the tire. 18. The safety tire according to claim 16, wherein the auxiliary layer is provided adjacent to the carcass of the tire. 19. The safety tire according to claim 16, wherein the auxiliary layer is provided adjacent to the partition wall. 20. The safety tire according to claim 1, wherein the foamable composition forms a composite including a continuous phase and bubbles after foaming. 21. The safety tire according to claim 20, wherein the cells of the composite are closed cells. 22. The gas according to claim 20, wherein the gas present in the bubbles of the composite is a fluorinated product of ethane,
C3-C8 linear aliphatic hydrocarbon and its fluorinated product, C3-C8 branched aliphatic hydrocarbon and its fluorinated product, C3-C8 alicyclic hydrocarbon and its fluorinated product A safety tire characterized in that it is at least one selected from the group consisting of nitrogen, nitrogen and air. 23. The composite according to claim 20, wherein the continuous phase of the composite is a polyvinyl alcohol resin,
Nylon resin, acrylonitrile polymer, acrylic polymer, vinylidene chloride polymer, acrylonitrile / styrene resin, polyethylene resin, polypropylene resin, polyester resin, polystyrene / polyethylene copolymer, and at least one of butyl rubber A safety tire characterized by being made. 24. The composite according to claim 20, wherein the continuous phase of the composite comprises a nylon-based resin, wherein the nylon-based resin comprises nylon 6, nylon 11, nylon 12, a nylon 6/66 copolymer and Nylon 6/12
A safety tire, which is at least one selected from copolymers. 25. The composite according to claim 20, wherein the continuous phase of the composite comprises an acrylonitrile-based polymer, wherein the acrylonitrile-based polymer is an acrylonitrile polymer, an acrylonitrile / methyl methacrylate copolymer, and acrylonitrile / methacrylate. A safety tire comprising at least one selected from an acrylonitrile copolymer and an acrylonitrile / methyl methacrylate / methacrylonitrile terpolymer. 26. The composite according to claim 20, wherein the continuous phase of the composite comprises an acrylic polymer, wherein the acrylic polymer is methyl methacrylate resin, methyl methacrylate / acrylonitrile copolymer, methyl methacrylate / A safety tire comprising at least one selected from a methacrylonitrile copolymer and a methyl methacrylate / acrylonitrile / methacrylonitrile copolymer. 27. The composite according to claim 20, wherein the continuous phase of the composite comprises a vinylidene chloride-based polymer, wherein the vinylidene chloride-based polymer is a vinylidene chloride / acrylonitrile copolymer, a vinylidene chloride / methacrylonitrile. Copolymer, vinylidene chloride / methyl methacrylate copolymer, vinylidene chloride / acrylonitrile /
At least one selected from methacrylonitrile copolymer, vinylidene chloride / acrylonitrile / methyl methacrylate copolymer, vinylidene chloride / methacrylonitrile / methyl methacrylate copolymer, vinylidene chloride / acrylonitrile / methacrylonitrile / methyl methacrylate copolymer A safety tire characterized by the following. 28. The composite according to claim 20, wherein the continuous phase of the composite has a gas permeability coefficient at 30 ° C. of 300 × 10 ⁻¹² (cc · cm / cm ² · s · cmH).
g) A safety tire characterized by the following. 29. A safety tire according to claim 1, wherein a side reinforcing layer made of hard rubber is disposed inside the sidewall portion of the tire. 30. The partition wall according to claim 1, wherein the partition wall has a gas permeability coefficient of 300 × 10 3 at 30 ° C.
^-12 (cc · cm / cm ² · s · cmHg) or less. 31. The partition according to claim 1, wherein the partition wall has a gas permeability coefficient of 20 × 10 at 30 ° C.
^-12 (cc · cm / cm ² · s · cmHg) or less. 32. The partition wall according to claim 1, wherein the partition wall has a gas permeability coefficient at 30 ° C. of 2 × 10.
^-12 (cc · cm / cm ² · s · cmHg) or less.