JP2002120510A - Safe tire, complex and expandable composition used for it, and manufacturing method of safe tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safe tire allowing stable running even in a damaged state of the tire without sacrificing rolling resistance and riding comfortableness in normal running before the damage of the tire. SOLUTION: In this safe tire having a complex having independent air bubble dispersed in a continuous phase made of a polymer body is disposed inside the hollow doughnut like tire, the inner pressure of the independent air bubble built in the complex at 25 deg.C is 150 kPa or higher, and number of kinds of gas filled into the complex is two or more.

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 puncture caused by an injury or the like, and more particularly to a safety tire which is excellent in both durability and riding comfort in running after being damaged.

[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 and an absolute pressure based on a vacuum (hereinafter, simply referred to as an internal pressure) is 250 to 350.
By maintaining the pressure at about kPa, tension is generated in the tire skeleton 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, a constant tension is generated in the skeleton of the tire, and while imparting a load supporting function,
The stiffness is increased to provide the basic performance required for vehicle travel, such as driving, braking and turning performance.

[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, as a result of losing the load support function, driving, braking and turning performance obtained by applying a predetermined internal pressure to the tire,
The vehicle equipped with the tires becomes unable to 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 so-called run flat tire having a flatness ratio of 60% or less.

However, a technique for adding a side reinforcing layer is as follows.
Since the longitudinal spring constant and the longitudinal spring constant of the tire are 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 technology 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, which have a structure in which an internal support is arranged to support a load during puncturing, are mainly applied.

However, the tire cannot withstand local repeated input generated between the tire and the internal support during 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 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.

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.
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, tires for trucks and buses and the like, in particular, tires that emphasize rolling resistance and ride comfort has been unknown. And since all foams have a low expansion ratio, the weight is large in place of the composite having air bubbles, and it is inevitable that the riding comfort and the fuel consumption deteriorate, and the inside of the closed cells is at atmospheric pressure. ,
Conventionally, it was not functionally sufficient to substitute high pressure air for tires.

[0010] Further, Japanese Patent No. 2987076 discloses a puncture tire in which a foam filler is inserted into an inner peripheral portion. 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 is a disadvantage that cannot be maintained.

[0011]

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

[0012]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and found that in order to constantly maintain the internal pressure of the tire properly, the inside of the tire should not be damaged even if it is injured. It has been found that it is effective to provide a structure that does not allow gas to leak out of the device. That is, the gist configuration of the present invention is as follows.

(1) In a safety tire in which a composite composed of a continuous phase of resin and closed cells is disposed inside a hollow donut-shaped tire, the internal pressure of the built-in closed cells at 25 ° C. is 150 kPa or more in absolute pressure. A safety tire characterized in that there are two or more types of gas sealed in the complex.

(2) A safety tire according to the above (1), wherein at least a part of the closed cells is formed by enclosing a mixed gas in each of the cells.

(3) In the above (1) or (2), the gas sealed in the closed cell is 200 kP absolute at 0 ° C.
A safety tire comprising a component having a vapor pressure of not less than a.

(4) In the above (1), (2) or (3), the gas sealed in the complex is nitrogen, air, fluorinated ethane, or a linear aliphatic having 3 to 8 carbon atoms. At least one selected from the group consisting of hydrocarbons and fluorinated products thereof, branched aliphatic hydrocarbons having 3 to 8 carbon atoms and fluorinated products thereof, and alicyclic hydrocarbons having 3 to 8 carbon atoms and fluorinated products thereof; A safety tire, comprising:

(5) In any one of the above (1) to (4), the air bubble content of the composite is from 80.00% by volume to 9%.
8.75% by volume of a safety tire.

(6) In any one of the above (1) to (5), the internal pressure of the closed cells at 25 ° C. is 200 k
A safety tire having a pressure of Pa or more.

(7) In any one of the above (1) to (6), the continuous phase of the composite comprises an acrylonitrile-based polymer, an acrylic polymer, a vinylidene chloride-based polymer, an acrylonitrile / styrene resin, a polyethylene resin, A safety tire comprising at least one selected from a polypropylene resin, a polyester resin, a polystyrene / polyethylene copolymer, a polyvinyl alcohol resin, a nylon resin, a diene rubber and butyl rubber.

(8) In any one of the above (1) to (7),
The continuous phase of the composite comprises a nylon-based resin, wherein the nylon-based resin is nylon 6, nylon 11, nylon 12,
A safety tire characterized in that it is at least one selected from nylon 6/66 copolymer and nylon 6/12 copolymer.

(9) A safety tire according to any one of the above (1) to (7), wherein the continuous phase of the composite comprises a polyvinyl alcohol resin.

(10) In any one of the above (1) to (7), the continuous phase of the composite comprises an acrylonitrile-based polymer, and the acrylonitrile-based polymer is an acrylonitrile polymer, an acrylonitrile / methacrylonitrile copolymer. A safety tire characterized in that it is at least one selected from acrylonitrile / methyl methacrylate copolymer and acrylonitrile / methacrylonitrile / methyl methacrylate terpolymer.

(11) In any one of the above (1) to (7), the continuous phase of the composite comprises a vinylidene chloride-based polymer, and the vinylidene chloride-based polymer is a vinylidene chloride / acrylonitrile copolymer, Vinylidene / methyl methacrylate copolymer, vinylidene chloride / methacrylonitrile 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.

(12) In any one of the above (1) to (7), the continuous phase of the composite comprises an acrylic polymer, and the acrylic polymer is a methyl methacrylate resin, a methyl methacrylate / acrylonitrile copolymer. A safety tire characterized in that it is at least one selected from a methyl methacrylate / methacrylonitrile copolymer and a methyl methacrylate / acrylonitrile / methacrylonitrile terpolymer.

(13) In any one of the above (1) to (12), 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.

(14) In any one of the above (1) to (13), the continuous phase of the composite has a gas permeability coefficient at 30 ° C. of 20 × 10 ⁻¹² (cc · cm / cm ² · s · cmHg).
A safety tire characterized by the following.

(15) In any one of the above (1) to (14), the continuous phase of the composite has a gas permeability coefficient at 30 ° C. of 2 × 10 ⁻¹² (cc · cm / cm ² · s · cmHg). A safety tire characterized by the following.

(16) The safety tire according to any one of the above (1) to (15), wherein the gas in the closed cells is a gas generated by foaming of a foaming agent.

(17) In any one of the above (1) to (16), the tire has an inner liner layer on the inner peripheral surface thereof, and the inner liner layer is formed of a nylon resin having a softening point of 170 to 230 ° C. and isobutylene paraffin. The gelation rate of the elastomer component, including the methyl styrene copolymer halide, is 50%.
A safety tire comprising a thermoplastic elastomer composition dynamically vulcanized to about 95%.

(18) In the above (17), the inner liner layer has a gas permeability coefficient at 30 ° C. of 20 × 10 ^−12.
(Cc · cm / cm ² · s · cmHg) or less.

(19) A composite having a continuous phase and closed cells, wherein the internal pressure of the closed cells contained in the composite at 25 ° C. is 150 kPa or more in absolute pressure, and the gas sealed in the composite is A complex, which is of two or more types.

(20) Acrylonitrile copolymer, acrylic polymer, vinylidene chloride polymer, acrylonitrile / styrene resin, polyethylene resin, polypropylene resin, polyester resin, polystyrene / polyethylene copolymer, polyvinyl alcohol resin, nylon resin ,
At least one polymer selected from diene rubbers and butyl rubbers, and nitrogen, air, fluorinated ethane,
C3-C8 linear aliphatic hydrocarbon and its fluorinated product, C3-C8 branched aliphatic hydrocarbon and its fluorinated product, and C3-C8 alicyclic hydrocarbon and its fluorocarbon At least two selected from the group consisting of
A foamable composition containing a seed.

(21) A method of manufacturing a safety tire by disposing a composite of hollow particles in which a gas component liquefied and sealed in polymer particles is heated and expanded inside a hollow donut-shaped tire. In forming the composite,
A method for manufacturing a safety tire, comprising using one or both of polymer particles containing two or more gas components and two or more polymer particles containing different gas components.

[0034]

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 is configured by disposing a composite 2 having closed cells inside the tire 1. In addition,
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. In the drawings, reference numeral 7 denotes an inner liner layer, and reference numeral 8 denotes a rim.

The composite 2 has closed cells in which individual cells are isolated by being surrounded by partition walls.
The internal pressure of the closed cells in the composite 2 at 25 ° C.
It is important that the pressure be 0 kPa or more, preferably 200 kPa or more. The internal pressure of the closed cell at 25 ° C is 150
If the pressure is less than kPa, the flexure of the composite becomes large and the amount of repeated deformation during rolling of the tire becomes large. Therefore, in addition to the increase in the fatigue history of the composite during normal running before the tire is injured, the composite caused by tire injuries The rate of damage development increases with an increase in the amount of deformation, and in this case also, the durability of the composite against repeated deformation is significantly reduced, and the performance when the tire is damaged and running is insufficient. Here, the internal pressure value is expressed as normal pressure (atmospheric pressure) of 100 kPa.
That is, the internal pressure of 200 kPa indicates that the pressure is twice the atmospheric pressure.

Further, it is important that two or more types of gas are filled in the complex 2 in the complex 2. This is because by mixing different types of gases in the complex, the internal pressure of the tire can be adjusted to a desired range according to, for example, changes in the outside air temperature or the tire temperature.

That is, enclosing two or more types of gases in the complex means that gases having different vapor pressure characteristics are mixed in the complex. For example, when two types of gases A and B are mixed, the closed cell 25
After maintaining the internal pressure at 200 ° C. or more at 200 ° C., a gas type B having a lower vapor pressure at the same temperature or a lower temperature at the same vapor pressure as gas type A is applied to gas type A. In other words, if the gas type B is given a property that it is liquid when the tire is not used or the tire temperature is low, and is vaporized when the temperature of the tire rises above the temperature range during normal continuous use, When the temperature rises above a predetermined range, the liquid gas type B is vaporized, and the heat of vaporization makes it possible to suppress a further rise in the temperature of the tire. As a result, an improvement in tire durability is achieved.

As the gas type B or the third gas type C, a gas which is a gas in the normal use temperature range of a tire, but liquefies in a low temperature range of 0 ° C. or less is mixed, for example, in the winter. When the temperature of the tire is low, such as on an icy road, the tire internal pressure can be reduced by liquefying a part of the mixed gas. Since the contact area of the tire is increased due to the decrease in the internal pressure, it is effective for improving the performance of the tire on an icy road, for example.

Suppression of the abnormal temperature rise of the tire,
Since the expansion of the contact area of the tire can be achieved by selecting and using gas types corresponding to the respective tires, the durability and the icy and snowy road can be obtained by appropriately mixing the gas types B and C in addition to the main gas type A. The tire which improved the tire performance at the same time can be provided. The gas type A is
At least 50 ma to give the tire a predetermined internal pressure
ss% must exist

As the gas type A, fluorinated products of ethane, propane and cyclopropane and their fluorinated products are preferable, while gas types B and C are preferable.
As cyclopropane, isobutane, n-butane,
Neopentane, cyclobutane, isopentane, n-pentane, cyclopentane, hexane, cyclohexane and fluorinated products thereof are preferred.

Here, two or more kinds of gases can be sealed in the complex according to the following three modes. That is, the first mode is a case where two or more types of gas are contained as a mixed gas in one closed cell, and the closed cells containing such a mixed gas constitute at least a part of all closed cells. is there. Next, the second mode is a mode in which one kind of gas is filled in each closed cell, but closed cells containing different gases are mixed. And the third
The aspect is an aspect that is a combination of the first aspect and the second aspect.

The bubble content of the composite 2 is 8
It is preferably from 0.00% to 98.75% 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. Further, when the bubble content exceeds 98.75% by volume, the degree of damage to the composite due to tire trauma increases, and the speed of its development also increases,
Also in this case, the durability of the composite against repeated deformation is significantly reduced.

Here, the bubble content is a ratio of the bubble volume to the volume of the composite disposed in the tire, expressed as a percentage, and can be specifically calculated by the following equation. . Air bubble content = {1− (use volume of resin or composition constituting composite / volume of tire)} × 100 where “the volume of use of resin or composition constituting composite” in the above formula 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 volume of the resin or composition constituting the composite is determined, for example, by weighing the composition in advance into 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 resin or 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 volume value in a state where the packing between the resin or composition particles was stable was adopted. Therefore, the volume used when the composition is in the form of particles means the sum of the total volume of the composition particles and the total volume of the voids between the composition particles.

Here, the following method can be used as a device for maximizing the durability of the composite used in the present invention. That is, during normal running (before tire damage)
200-300 kPa between the complex and the tire inner surface
Filling a certain amount of air actively compresses the complex in the tire. With this contrivance, it is possible to reduce the load share ratio of the composite 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 charged air between the composite and the inner surface of the tire is dissipated due to the tire damage, the running performance in the tire damaged state is greatly improved as compared with the case where the above method is not adopted.

The composite 2 is arranged to apply an indispensable internal pressure to the tire. That is, a structure was realized in which the composite 2 was disposed inside the tire, a predetermined internal pressure was applied to the tire, and tension was generated in the tire frame such as the carcass and belt of the tire. Therefore, since the proper internal pressure is applied to the tire by the composite 2, there is no need to regulate the tire structure itself, and a new safety tire can be provided by using a general-purpose tire and a general-purpose rim.

The tire in which the composite 2 is disposed inside is characterized in that even if the tire is damaged, the tension of a case such as a normal pneumatic tire does not easily decrease. Because, when the tire is damaged, a part of the complex 2 is damaged on the inner surface of the tire near the wound,
The gas in some closed cells of this damaged part may escape to the outside of the tire. However, if this phenomenon is compared to a conventional pneumatic tire, the internal pressure is reduced only in a very small part of the region. Also, there is no puncture in the conventional pneumatic tire. Furthermore, since the probability of damage to the composite 2 due to tire trauma is extremely low and the area of the damage is extremely limited, the internal pressure of the tire given by the composite 2 may be so low as to impair the tire function. Is impossible.

In addition, although the vicinity of the damaged closed cell drops to the atmospheric pressure, the closed cells in the surrounding area have a pressure of 150 kP.
As a result of expansion due to having an internal pressure equal to or higher than a, the damaged closed cell region is compressed and the damaged portion is closed, so-called self-repair becomes possible.

Here, when arranging the composite inside the tire according to the present invention, by adding a liquid that does not substantially swell the continuous layer of the composite inside the tire, a tire damaged portion when the tire is damaged is added. It is possible to enhance the sealing function of the tire and further extend the running distance after the tire is damaged. That is, since the composite has a substantially spherical shape, it has high fluidity, and therefore can be easily filled into the tire and the rim assembly through an inlet having a small inner diameter such as a valve of the tire. On the other hand, when the tire is injured, the composite will collect on the inner surface of the injured part in an attempt to blow out from the injured part to the outside of the tire. However, since the damaged path from the inner surface of the damaged portion to the outer peripheral surface of the tire has a complicated and intricate shape instead of a straight line, the complex that has entered through the wound on the inner surface of the tire is impeded from moving along the path,
A large number of composites will gather in a compressed state on the inner surface of the damaged part, and the damaged part will be sealed by the composite. At that time, if the liquid is added together with the complex inside the tire, based on the affinity of the complex surface and the liquid and the viscosity of the liquid,
Since several to several thousand composites can be assembled, the damaged portion can be instantaneously filled with the aggregate of composites when the tire is damaged.

Furthermore, since the liquid to be mixed has a clearly higher specific gravity than the composite, during normal running, a large amount of the liquid is distributed on the inner surface of the tire tread due to the centrifugal force accompanying the rolling of the tire. This indicates that there are a large number of relatively large aggregates near the inner surface of the tire tread portion during normal running. Therefore, when the tire is injured by stepping on a foreign substance or the like, many of the composites 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 must be considered in production. That is, when filling the tire, it is important to fill the complex in a state of high fluidity, 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, a method of applying the liquid to be mixed to the inner surface of the tire or rim before filling, or a method of injecting the liquid into the tire and rim assembly after filling the complex is efficient and reliable.

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

In order to provide a predetermined tire pressure by the composite 2, the gas sealed at a predetermined pressure in the closed cells in the composite 2 must not leak from the bubbles to the outside of the foam. As described above, it is important that the matrix of closed cells has a property that gas is difficult to permeate in 2 in order to achieve this. A material having low property, specifically, acrylonitrile-based polymer, acrylic polymer, vinylidene chloride-based polymer, acrylonitrile / styrene resin (AS), polyethylene resin (PE), polypropylene resin (PP), polyester resin (PET), polystyrene / polyethylene copolymer (PS / PE), polyvinyl alcohol resin, nylon resin, diene It is preferably made of at least any one of rubber and butyl rubber. These materials are particularly effective for the present invention, since any of these materials can be relatively easily formed into a composite in a tire and has flexibility against input due to tire deformation.

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 the acrylonitrile-based polymer, at least one selected from acrylonitrile polymer, acrylonitrile / methacrylonitrile copolymer, acrylonitrile / methyl methacrylate copolymer, and acrylonitrile / methacrylonitrile / methyl methacrylate terpolymer; The polymer is at least one selected from methyl methacrylate resin, methyl methacrylate / acrylonitrile copolymer, methyl methacrylate / methacrylonitrile copolymer and methyl methacrylate / acrylonitrile / methacrylonitrile terpolymer. Examples of the coalesce include vinylidene chloride / acrylonitrile copolymer, vinylidene chloride / methyl methacrylate copolymer, vinylidene chloride / methacrylic acid. Ronitrile 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, As the nylon resin, at least one selected from the group consisting of nylon 6, nylon 11, nylon 12, nylon 6/66 copolymer and nylon 6/12 copolymer is advantageously adapted. Each of these materials has a small gas permeability coefficient and low gas permeability, so that the gas in the closed cells does not leak to the outside, and the internal pressure of the closed cells can be maintained in a predetermined range.

Next, the continuous phase of the composite at 30 ° C.
Gas permeability coefficient is 300 × 10^-12 (Cc · cm / cm^Two 
S · cmHg) or less, preferably at 30 ° C.
Permeability coefficient is 20 × 10^-12 (Cc · cm / cm^Two ・ S ・
cmHg) or less, more preferably gas at 30 ° C.
Permeability coefficient is 2 × 10^-12 (Cc · cm / cm^Two ・ S ・ c
mHg) or less is recommended. This is usually
Gas Permeability of Inner Liner Layer in Pneumatic Tires
Excess coefficient is 300 × 10^-12 (Cc · cm / cm ^Two ・ S ・
cmHg) or less and sufficient internal pressure holding function
In view of its experience, the continuous phase of the composite
The gas permeability coefficient at 0 ° C. is 300 × 10^-12 (Cc ・
cm / cm^Two S · cmHg) or less.
However, at this level of gas permeability coefficient,
Since the internal pressure needs to be replenished about once, the maintenance
20 × 10^-12 (Cc · cm / cm^Two 
S · cmHg) or less, more preferably 2 × 10^-12 
(Cc · cm / cm^Two ・ S ・ cmHg) or less
Is recommended.

The gas is refilled into the bubbles by using a normal device for filling the tire with air, or by placing the tire in a closed room filled with a desired gas and maintaining a predetermined internal pressure. Can be adjusted again, but when a polymer having a large gas permeability coefficient is used for the continuous phase, this refilling operation must be performed frequently, which is not practical.

The gas sealed in the complex is nitrogen, air, fluorinated ethane, a linear aliphatic hydrocarbon having 3 to 8 carbon atoms and its fluorinated product, and 3 carbon atoms.
To 8 branched aliphatic hydrocarbons and fluorinated products thereof, and at least one selected from the group consisting of alicyclic hydrocarbons having 3 to 8 carbon atoms and fluorinated products thereof. 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.

The method for forming a composite having closed cells is not particularly limited, but it is preferable to use a foaming agent.
Examples of the foaming agent include a high-pressure compressed gas and a liquefied gas, in addition to a pyrolytic foaming agent that generates a gas by thermal decomposition. In particular, many thermally decomposable blowing agents have a characteristic of generating nitrogen, and a composite obtained by appropriately controlling the reaction has nitrogen in bubbles. Many of the pyrolytic foaming agents have a characteristic of generating nitrogen by thermal decomposition, and a 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.

When the resin continuous phase forming the composite is melted and filled into the tire at a high pressure together with the air to form the composite, air remains in the air bubbles. Further, during the above resin continuous phase polymerization, propane, butane, pentane, hexane, heptane, octane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane and cyclooctane, etc. are liquefied under high pressure and dispersed in the reaction solvent. There is also a method of emulsion polymerization, whereby the gas components such as propane, butane, pentane, hexane, heptane, octane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane and cyclooctane are continuously converted into a liquid state by the above resin. It is possible to obtain expandable resin particles encapsulated in a phase, which is filled into a tire, and when a composite is formed by heating, propane, butane, pentane,
Hexane, heptane, octane, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane and cyclooctane are encapsulated. The isomers of butane, pentane, hexane, heptane and octane include isobutane, isopentane, neopentane, 2-methylpentane, 2,2-dimethylbutane, methylhexanes, dimethylpentanes, trimethylbutane, methylheptane, dimethyl Hexanes, trimethylpentanes and the like can be mentioned.

Further, expandable resin particles containing a liquefied gas such as propane, butane, and pentane are filled into a tire together with a melt of a resin continuous phase forming a composite, and heated to form an inner portion. It is also possible to obtain a tire on which the composite is arranged.

The target tire can be obtained by subjecting the foamable resin particles, which have been subjected to surface coating such as a surfactant and an oil agent, to the surface of the foamable resin particles and heating and foaming them in a tire. Further, the target tire can also be obtained by preliminarily heating and foaming the resin particles containing the liquefied gas to form substantially spherical hollow particles, and filling the hollow particles into the tire.

The safety tire of the present invention is characterized in that the pressure inside the closed cell of the composite disposed particularly is higher than the atmospheric pressure. The following new manufacturing methods largely depend. Although the production method will be specifically described below, it is preferable to monitor the internal pressure and the internal temperature of the tire during the production process and control the generation and growth of bubbles while appropriately adjusting the production method.

In the first method, after a predetermined amount of the foamable composition is charged into the tire, the tire is incorporated into a rim,
Next, the tire assembly is heated to foam inside the tire. In addition, heating can be performed using microwaves or electron beams in addition to an oven or steam, and the same applies to the following method.

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 material, and inject into the tire assembly after rim assembly, Next, the tire assembly is heated to foam inside the tire.

A third method is to inject butane, propane, pentane, or the like in polymer particles in a liquefied state, such as Expancel (trademark), into the tire assembly after the rim assembly. Then, the tire assembly is heated to foam inside the tire.

A fourth technique is to melt the raw material to be the continuous phase of the composite, and in a state where fluidity has appeared, put high-pressure air or high-pressure gas such as CO ₂ or N ₂ inside the tire after the rim is assembled. At the same time, the mixture is injected into the tire assembly to form a composite inside the tire assembly.

The fifth technique is to form a predetermined amount of the foamable composition into an annular shape, insert it into the tire,
The tire is incorporated into a rim and the tire assembly is then heated and foamed inside the tire. The foamable composition does not necessarily have to be annular, but is preferably annular from the viewpoint of workability and uniform filling.

The sixth technique is to liquefy and enclose butane, propane, pentane and the like in polymer particles together with a melt of a resin continuous phase forming a composite, such as Expancel (trade name). Then, the tire is assembled into a rim-assembled tire, and then the tire assembly is heated as required to foam inside the tire.

A seventh method is to liquefy and enclose butane, propane, pentane, or the like in polymer particles, such as Expancel (trade name), and heat-foam them in advance to form roughly spherical hollow particles. This is filled into the tire and rim assembly. In this case, the continuous phase of the composite is
Refers to a polymer constituting the shell of the hollow particle. In particular, when the composite gas contains a component composition containing an aliphatic fluorocarbon containing no chlorine, the above-described methods can be used, but the following methods are suitable.

That is, in the eighth method, tetrafluoroethane, difluoroethane, fluoroethane, octafluoropropane, 2H-heptafluoropropane, decafluorobutane, cyclofluorobutane, dodecafluoropentane, and the like are liquefied in polymer particles. The sealed product is poured into the tire assembly after the rim is assembled, and then the tire assembly is heated to foam inside the tire. In this case, the continuous phase of the composite becomes a polymer constituting the shell of the hollow particle.

In the ninth method, tetrafluoroethane, difluoroethane, fluoroethane, octafluoropropane, 2H-heptafluoropropane, decafluorobutane, cyclofluorobutane, dodecafluoropentane and the like are liquefied and sealed in polymer particles. The particles are preliminarily heated and foamed to form substantially spherical hollow particles, which are filled in the tire and rim assembly. In this case, the continuous phase of the composite becomes a polymer constituting the shell of the hollow particle.

The continuous phase includes an acrylonitrile polymer, an acrylic polymer, a vinylidene chloride polymer, an acrylonitrile / styrene resin (AS), a polyethylene resin (PE), a polypropylene resin (PP), and a polyester resin (PET). At least one selected from polystyrene / polyethylene copolymer (PS / PE), polyvinyl alcohol resin, nylon resin, diene rubber and butyl rubber is suitable.

On the other hand, a tire usually has an inner liner layer on the inner peripheral surface thereof. The inner liner layer is formed of 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 comprises a thermoplastic elastomer composition obtained by dynamically vulcanizing an elastomer component containing a halide to a gelation ratio of 50 to 95%. This is because, unlike a conventional inner liner layer mainly composed of butyl rubber, by using a nylon resin as a continuous phase, the gas permeability becomes extremely low, so that the function of the inner liner layer can be enhanced. on the other hand,
A thermoplastic elastomer composition obtained by dynamically vulcanizing an elastomer component containing a halide of an isobutylene paramethylstyrene copolymer to a gelation ratio of 50 to 95% provides high flexibility, heat resistance and durability. An excellent inner liner layer is obtained. The inner liner layer having the above characteristics can create an environment that facilitates the gas in the closed cells of the composite to remain in the cells.

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 further removing the residue by n-h for 8 hours.
By Soxhlet extraction with hexane, the unvulcanized elastomer component was extracted with a solvent, and the acetone and n-hexane extracts were dried and the weight of the solvent was measured. Gelation rate (%) = [{weight of all formulations-(extracted amount of acetone + extracted amount of n-hexane-amount of stearic acid)] / weight of all formulations] x 100

[0075] Further, the inner liner layer, the gas permeability coefficient at 30 ° C. is ^{20 × 10 -1 2 (cc ·} cm / c
m ² · s · cmHg) or less. Even if the gas in the air bubbles leaks out of the composite for some reason, if the gas permeability of the inner liner layer is sufficiently low, the gas in the air bubbles in the composite leaks out of the tire. This is because it is less likely to come out, which is advantageous for maintaining the internal pressure of the tire. That is, the gas permeability of the inner liner layer is a factor that directly determines the pressure retention of the tire as a pressure vessel. Of course, it is fundamental that the gas permeability of the continuous phase forming the composite is low, and it is ideal to use an inner liner layer having a low gas permeability.

FIG. 1 shows the application of the composite to a general-purpose tire. However, for example, as shown in FIG. 2, the composite can be applied to a tire having a structure suitable for a run flat. . That is, the tire shown in FIG. 2 is provided with a side reinforcing layer 9 made of hard rubber particularly inside the sidewall portion of the tire to reinforce the side portion.

[0077]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A composite having various specifications shown in Tables 1 and 2 is applied to a tire having the structure shown in FIG. 1 or 2 as shown in the table, and a safety tire for passenger cars of size 185 / 70R14 is prototyped. did. Here, the tire 1 conforms to the general structure of the type and size of the tire. Table 1
The contents of the foaming composition and the foaming agent in the cases 2 and 2 are as shown in Table 3, and similarly, the rubber type of the inner liner layer is as shown in Table 4.

The pressures in the bubbles shown in Tables 1 and 2 were calculated by the following equation (A) based on the following definitions. 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 ρs : Specific gravity of the composite sampled from the tire under atmospheric pressure, expressed as ρs = Ws / Vs. Where, Vs: the volume of the composite sampled from the tire under atmospheric pressure Ws: the weight of the composite sampled from the tire

Next, with respect to the tire filled with the composite, 5000 km and a load 4 were applied at a room temperature of 38 ° C.
Drum running at 17 kN was performed to give a certain running history to each tire. At this time, the tire temperature during the running of the drum was measured by a non-contact thermometer, and the temperature value when the tire reached a flat state was compared to compare the heat generation characteristics of each tire. In addition,
For comparison, Comparative Example 1 was used as a control. The same applies to the following evaluations.

The grip performance of the tires on ice and snowy roads was measured and compared on a test course on icy roads and snowy roads at a speed of 20 km / h on icy roads and snowy roads. The exponent is displayed as the reciprocal,
The larger the value, the better.

Furthermore, each tire and rim assembly after the above-mentioned drum running was mounted on a 2000 cc class passenger car, and a nail having a diameter of 3 mm and a length of 3 cm was passed through the tread from outside the tire tread. After the injury was caused, a load corresponding to four passengers was applied, the test course was run at 90 km / h, a maximum of 300 km was traveled, and the possible travel distance was measured. The criterion was that a travel distance of 200 km or more was accepted. The results of these surveys are shown in Tables 1 and 2.

[0082]

[Table 1]

[0083]

[Table 2]

[0084]

[Table 3]

[0085]

[Table 4]

[0086]

According to the present invention, a safety tire capable of running stably even in a tire-damaged state without sacrificing rolling resistance and riding comfort during normal running before the tire is damaged. Can be provided. In addition, since abnormal heat generation of the tire can be avoided, it is possible to improve the durability of the tire, and it is possible to improve the grip performance especially on an icy and snowy road by adjusting the internal pressure according to the use environment temperature of the tire. .

[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 another safety tire according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 tire 2 composite 3 bead core 4 carcass 5 belt 6 tread 7 inner liner layer 8 rim 9 side reinforcement layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08J 9/32 CEZ C08J 9/32 CEZ CFG CFG C08L 23/28 C08L 23/28 77/00 77/00 / / B29K 105: 04 B29K 105: 04 C08L 101: 00 C08L 101: 00 F term (reference) 4F074 AA37A AA48A AA49A BA13 BA35 BA36 BA37 BA39 BA53 CB52 CB61 CB66 CB68 DA12 DA59 4F212 AA04 AA11 AAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AH20 UA02 UB01 VC07 4J002 BB18X BB24X BC04X CL00W GN01

Claims (21)

[Claims] 1. A safety tire in which a composite comprising a continuous phase of resin and closed cells is disposed inside a hollow donut-shaped tire, wherein the internal pressure of the built-in closed cells at 25 ° C. is 150 kPa or more in absolute pressure. A safety tire, wherein two or more types of gas are sealed in the composite body. 2. The safety tire according to claim 1, wherein at least a part of the closed cells has a mixed gas sealed in each cell. 3. The safety tire according to claim 1, wherein the gas sealed in the closed cells contains a component having a vapor pressure of 200 kPa or more at 0 ° C. in absolute pressure. 4. The gas according to claim 1, 2 or 3, wherein the gas enclosed in the complex is nitrogen, air, a fluorinated ethane, a linear aliphatic hydrocarbon having 3 to 8 carbon atoms and a fluorinated product thereof. A branched aliphatic hydrocarbon having 3 to 8 carbon atoms and a fluorinated product thereof, and at least one selected from the group consisting of an alicyclic hydrocarbon having 3 to 8 carbon atoms and a fluorinated product thereof. Safety tires. 5. The method according to claim 1, wherein
The composite has a cell content of 80.00% by volume to 98.7% by volume.
A safety tire characterized by being 5% by volume. 6. The method according to claim 1, wherein
The internal pressure of the closed cell at 25 ° C is 200 kPa absolute
A safety tire characterized by the above. 7. The method according to claim 1, wherein
The continuous phase of the composite is composed of an acrylonitrile-based polymer, an acrylic polymer, a vinylidene chloride-based polymer, an acrylonitrile / styrene resin, a polyethylene resin, a polypropylene resin, a polyester resin, a polystyrene / polyethylene copolymer, a polyvinyl alcohol resin, and a nylon-based polymer. A safety tire comprising at least one selected from resin, diene rubber and butyl rubber. 8. The method according to claim 1, wherein
The continuous phase of the composite comprises a nylon-based resin, wherein the nylon-based resin is nylon 6, nylon 11, nylon 12,
A safety tire characterized in that it is at least one selected from nylon 6/66 copolymer and nylon 6/12 copolymer. 9. The method according to claim 1, wherein
A safety tire, wherein the continuous phase of the composite comprises a polyvinyl alcohol resin. 10. The composite according to claim 1, wherein the continuous phase of the composite comprises an acrylonitrile-based polymer, wherein the acrylonitrile-based polymer is an acrylonitrile polymer, an acrylonitrile / methacrylonitrile copolymer, and acrylonitrile / methyl. A safety tire comprising at least one selected from a methacrylate copolymer and an acrylonitrile / methacrylonitrile / methyl methacrylate terpolymer. 11. The composite according to claim 1, wherein the continuous phase of the composite comprises a vinylidene chloride polymer, wherein the vinylidene chloride polymer is a vinylidene chloride / acrylonitrile copolymer, a vinylidene chloride / methyl methacrylate. Copolymer, vinylidene chloride / methacrylonitrile 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. 12. The composite according to claim 1, wherein the continuous phase of the composite comprises an acrylic polymer, wherein the acrylic polymer is a methyl methacrylate resin, a methyl methacrylate / acrylonitrile copolymer, a methyl methacrylate / A safety tire comprising at least one selected from a methacrylonitrile copolymer and a methyl methacrylate / acrylonitrile / methacrylonitrile terpolymer. 13. The composite phase according to claim 1, 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. 14. The continuous phase of a composite according to claim 1, wherein the continuous phase of the composite has a gas permeability coefficient at 30 ° C. of 20 × 10 ⁻¹² (cc · cm / cm ² · s · cmHg).
A safety tire characterized by the following. 15. The continuous phase of the composite according to claim 1, wherein a gas permeability coefficient at 30 ° C. is 2 × 10 ⁻¹² (cc · cm / cm ² · s · cmHg) or less. Safety tire characterized by the following. 16. The safety tire according to claim 1, wherein the gas in the closed cells is a gas generated by foaming of a foaming agent. 17. The tire according to claim 1, further comprising an inner liner layer on the inner peripheral surface of the tire, wherein the inner liner layer is formed of a nylon resin having a softening point of 170 to 230 ° C. and isobutylene paramethylstyrene. The gelation rate of the elastomer component including the unified halide is 50%.
A safety tire comprising a thermoplastic elastomer composition dynamically vulcanized to 95%. 18. The inner liner layer according to claim 17, wherein the inner liner layer has a gas permeability coefficient at 30 ° C. of 20 × 10 ^−12.
(Cc · cm / cm ² · s · cmHg) or less. 19. A composite having a continuous phase and closed cells, wherein the internal pressure of the closed cells contained in the composite at 25 ° C. is 150 kPa or more in absolute pressure, and the gas sealed in the composite is 2 kPa. A complex, wherein the complex is at least one kind. 20. An acrylonitrile copolymer, an acrylic polymer, a vinylidene chloride polymer, an acrylonitrile / styrene resin, a polyethylene resin, a polypropylene resin, a polyester resin, a polystyrene / polyethylene copolymer, a polyvinyl alcohol resin, a nylon resin,
At least one polymer selected from a diene rubber and a butyl rubber, and nitrogen, air, and a fluorinated ethane;
C3-8 straight-chain aliphatic hydrocarbon and its fluorinated product, C3-8 branched aliphatic hydrocarbon and its fluorinated product, and C3-8 alicyclic hydrocarbon and its fluorocarbon At least two selected from the group consisting of
A foamable composition containing a seed. 21. A method for manufacturing a safety tire by arranging a composite of hollow particles in which a gas component liquefied and sealed in polymer particles is heated and expanded inside a hollow donut-shaped tire. In molding the composite,
A method for manufacturing a safety tire, comprising using one or both of polymer particles enclosing two or more gas components and two or more polymer particles enclosing different gas components.