JP2020200009A - Tire life extension agent - Google Patents

Abstract

To provide a tire life extension agent which can effectively radiate excess heat accumulated in a tire without special processing of a tire and special modification of a vehicle, prevents puncture without peeling layers of a carcass and a rubber material according to the purpose, and/or can suppress occurrence of rust of a wheel, and can easily and inexpensively extend a tire life.SOLUTION: A tire life extension agent is a composition in which water, ethylene glycol and bentonite are used as base materials, and the composition is composed of only the base materials or the base materials are mixed with either or both of an aramid fine fiber or a modified epoxy resin.SELECTED DRAWING: Figure 3

Description

The present invention relates mainly to a tire life extending agent for the purpose of extending the life of a tire mounted on a large vehicle such as a freight truck or a dump truck.

Tires mounted on vehicles have a short life due to various factors such as improper air pressure, excessive heat, flat tires and aging. Regarding the improper air pressure, the wear of the central part of the tread progressed in the state of excessive air pressure, and the wear of both ends of the tread progressed in the state of insufficient air pressure, which caused a shortening of life due to tire deformation. Regarding excess heat, frictional heat is generated due to dynamic friction between the road surface and the tread during running, and hysteresis loss due to expansion and contraction of the rubber material of the shoulder part and the sidewall part connected to it and the internal carcass, and the frictional heat accumulates. As a result, an excess heat state was formed, and the excess heat was a cause of shortening the life. Further, regarding a flat tire, when a sharp foreign substance such as a nail is pierced from the outside, air is released from the puncture, a phenomenon similar to the above-mentioned insufficient air pressure state occurs, and finally the flat tire becomes inoperable. With regard to aging, the vulcanized rubber treated to increase the strength and elasticity of the tire progresses to a supervulcanized state due to oxygen, ultraviolet rays and heat in the air, and further depolymerizes and oxidizes. The vulcanized rubber ages due to a chemical reaction such as, which causes deterioration of strength and elasticity, and the deterioration causes shortening of life.

Among the above-mentioned various factors, it is well known that the excess heat accelerates the deterioration of the rubber material and the reinforcing member constituting the tire, reduces the strength and elasticity of the tire, and shortens the life. In order to solve this problem, for example, in the publication (name of the invention: pneumatic tire) described in Patent Document 1, rods containing a rubber component and a highly thermally conductive material are arranged in parallel with each other and coated with a coated rubber. A tire is proposed in which one end of a rod-shaped body is exposed on the outer surface of the tire and the other end is located inside the tire, and the heat-dissipating member is described in Patent Document 2 (title of invention: (Pneumatic tires), a tire in which a coating agent having a high thermal radiation coefficient is applied to at least a part of the tire surface of the tread portion or the groove in the tread portion or the sidewall portion is proposed, and the publication (invention of the invention) described in Patent Document 3 In the name: tire cooling system and method), a liquid in which ethylene glycol and water are evenly mixed is put inside the tire, and a heat transfer device arranged inside the rim and the heat transfer device arranged outside the rim. A system has been proposed in which a tire is actively cooled by forming a liquid path formed by connecting the inlet / outlet of the liquid and the rotary wheel seal connected to the tire and a heat exchanger installed in the vehicle.

With regard to punctures, a chemical aqueous solution containing resin fine particles and short fibers is injected into the tire in advance, and when a sharp foreign substance such as a nail sticks, the chemical aqueous solution flows out from the puncture hole together with air, and the chemical aqueous solution flows out. There is a so-called puncture preventive agent in which resin fine particles and short fibers contained in the above seal puncture holes to prevent a puncture. For example, in the publication (title of the invention: tire puncture preventive agent) described in Patent Document 4, 100 parts by weight of water is used. On the other hand, the composition is characterized by consisting of 5 to 30 parts by weight of polyvinyl alcohol, 1 to 20 parts by weight of short fibers having an average fiber length of 0.1 mm or more, and 20 to 100 parts by weight of glycol having 2 to 4 carbon atoms. A tire puncture inhibitor has been proposed.

JP 2004 130885 JP-A-2005-199786 Special table SHO 58-500114 JP-A-10-017851

However, in order to dissipate excess heat, the tire described in Patent Document 1 uses an expensive material such as carbon nanotube as a heat radiating member and is configured by arranging the heat radiating member at the time of manufacturing. It has the disadvantage of high cost. Further, the tire described in Patent Document 2 can be used easily and inexpensively because it is only applied with a heat-dissipating coating agent, but it is quickly worn and used on a freight truck traveling a long distance or a dump truck traveling on a rough road. It has the drawback of not being able to withstand. Further, since the cooling system described in Patent Document 3 is a device that circulates a liquid obtained by mixing ethylene glycol and water contained in a tire via a heat exchanger installed in a vehicle, the rim, wheels and the cooling system There is a problem that the vehicle needs special modification and cannot be easily realized.

Further, in the puncture inhibitor described in Patent Document 4 in order to prevent puncture, it is said that the short fibers of the composition are preferably hemp and / or polyethylene fibers, but since the polyethylene fibers have a very high thermal expansion coefficient, they can be used in puncture holes. The problem is that the contained fibers expand due to excessive heat and the layers of the carcass and the rubber material are peeled off, and the chemical aqueous solution in which water, polyvinyl alcohol, glycol having 2 to 4 carbon atoms, etc. are mixed is made of iron. There was a problem that rust would occur if there were scratches or peeling of paint inside the tires of the wheels (hereinafter simply referred to as wheels).

The present invention has been made to solve the above-mentioned drawbacks and problems, and effectively releases excess heat accumulated in the tire without applying special modification to the tire or special modification to the vehicle. It can be heated, and depending on the purpose, the layers of the carcass and the rubber material can be prevented from peeling off and puncture can be prevented, and / and the occurrence of rust on the wheel can be suppressed, and it is simple and inexpensive. It is an object of the present invention to provide a tire life extending agent capable of extending the tire life.

In order to solve the above problems, the tire life extender of the present invention is used by injecting a solution consisting of the following composition into the tire to perform special processing on the tire or special modification to the vehicle. Excess heat accumulated in the tire can be effectively dissipated, and puncture is prevented without peeling of the layer between the carcass and the rubber material depending on the purpose, and / and the occurrence of rust on the wheel is suppressed. We solved what we could do through a wide range of experiments. That is, a solution is prepared by using water, ethylene glycol and bentonite as a base material, and mixing only the base material or one or both of aramid fine fibers and modified epoxy resin with the base material.

When only the heat dissipation effect of excess heat is obtained, the composition is water, ethylene glycol and bentonite, and the composition ratio of water is 47.5 to 45.5%, ethylene glycol is 47.5 to 45.5%, and bentonite is 5 to 9%. A solution consisting of (% by weight).

To obtain heat dissipation and puncture prevention effect of excess heat, the composition is water, ethylene glycol, bentonite and aramid fine fibers, and water 46.75 to 44%, ethylene glycol 46.75 to 44%, bentonite 5 to 9%, A solution having a composition ratio (% by weight) of 1.5 to 3% of aramid fine fibers is used.

In order to obtain the effect of dissipating excess heat and suppressing the generation of rust, the composition is water, ethylene glycol, bentonite and a modified epoxy resin, and water is 46 to 42.5%, ethylene glycol is 46 to 42.5%, and bentonite is 5 to 9. %, And the modified epoxy resin is a solution having a composition ratio (% by weight) of 3 to 6%.

In order to obtain the effect of heat dissipation of excess heat, prevention of puncture and suppression of rust generation, the composition is water, ethylene glycol, bentonite, aramid fine fiber and modified epoxy resin, and water is 45.25 to 41%, ethylene glycol is 45.25 to The solution comprises 41%, bentonite 5-9%, aramid fine fibers 1.5-3%, and modified epoxy resin 3-6% in a composition ratio (% by weight concentration).

The aramid fine fiber is a fine fiber obtained by grinding 100% aramid fiber with a stone mill type grinder or the like.

If an appropriate amount of the tire life extending agent of the present invention is injected into the tire and used, the tire life extending agent accumulated at the bottom of the tire during running will be generated by centrifugal force on the tread portion, shoulder portion and sidewall portion. It spreads evenly on the inner surface of the tire, efficiently guides the frictional heat generated in the tread and shoulders to the sidewalls, and by forced air cooling with the outside air due to the rotation of the tires on the tread and the sidewalls on the outer surface of the tire. It has the effect of dissipating the frictional heat and effectively dissipating excess heat. Further, even when the tire is stopped, the tire life extending agent remains on the inner surface of the tire in the tread portion and the sidewall portion for a while immediately after the stop, so that the heat dissipation by natural air cooling can be efficiently maintained. Further, in the case of a solution in which aramid fine fibers are mixed, the coefficient of thermal expansion of the aramid fine fibers is very low, so that the aramid fine fibers do not undergo thermal expansion and the layers of the carcass and the rubber material do not peel off. In the case of a solution mixed with a modified epoxy resin, a resin thin film is formed so that the modified epoxy resin covers the rust layer, and the solution is separated from the solution in which water and ethylene glycol are evenly mixed. , It has the effect of suppressing the occurrence of rust. Furthermore, bentonite in the base material closes the pores on the inner surface of the tire, and the aramid fine fibers prevent leakage of rims and beads, which also has the effect of preventing a natural decrease in air pressure.

It is sectional drawing of the tire in the initial state which injected the tire life extender of this invention. It is a cross-sectional view of a tire after injecting the tire life extending agent of this invention and having passed a sufficient use period. It is sectional drawing of the tire running by injecting the tire life extending agent of this invention. It is a figure which graphed the temperature measurement data of each part of a tire without injection of the tire life extender of this invention. It is the figure which graphed the temperature measurement data of each part of the tire with the injection of the tire life extender of this invention.

The method for producing the tire life extender of the present invention will be described in detail, although there are some differences depending on the purpose.

In this case, first, bentonite and aramid fine fibers are mixed with water and stirred sufficiently to swell the bentonite to form a pregel. The bentonite has a viscosity of 3000 to 5000 Pa. It is for adjusting to s, and bentonite for water system is used. The pregel is left to stand for a while to stabilize its viscosity, and then ethylene glycol and the modified epoxy resin are further mixed and sufficiently stirred to complete the production. When the coating on the inner surface of the wheel is peeled off and the metal comes into contact with water or rust has already occurred, the modified epoxy resin adheres to the metal to form a resin thin film on the surface thereof.

The composition ratio (% by weight concentration) of each composition was 45.25 to 41% for water, 45.25 to 41% for ethylene glycol, 5 to 9% for bentonite, 1.5 to 3% for aramid fine fibers, and 3 modified epoxy resins. A solution consisting of ~ 6%. A small amount of preservatives and antifoaming agents may be mixed during the above production.

The above-mentioned aramid fine fibers are obtained by cutting 100% aramid fibers to about 6 mm and grinding them with a millstone grinder or the like into pulp.

FIG. 1 is a cross-sectional view of a tire in an initial state in which the tire life extending agent of the present invention is injected, and an appropriate amount of the tire life extending agent 6 is injected into each tire 1 from an air valve (not shown) of the tire 1 using an injection tool. It shows the state of the tire. In this state, the tire life extending agent 6 is accumulated in the inner bottom portions of the tread portion 2 and the shoulder portion 3. Further, it shows a state in which rust 7 is generated in the central portion of the inner surface of the wheel 5. FIG. 2 is a cross-sectional view of the tire after the tire life extending agent of the present invention has been injected and after a sufficient period of use. After a sufficient period of use, the modified epoxy resin in the tire life extending agent 6 forms a layer of rust 7. A resin thin film 8 can be formed so as to cover the resin thin film 8 and separated from a solution in which water and ethylene glycol are evenly mixed to suppress the generation of rust 7.

Since the modified epoxy resin does not have an epoxy group, a curing agent is not required, but drying is required for curing. The inside of the tire 1 in which the tire life extending agent 6 is injected is a solution in which water and ethylene glycol are evenly mixed, but since the ethylene glycol has high hygroscopicity, it can be cured even in the sealed tire 1. Once the film is formed, it does not dissolve.

FIG. 3 is a cross-sectional view of a tire running with the tire life extending agent of the present invention injected, and the tire life extending agent 6 accumulated at the bottom of the tire 1 during running is a tread portion 2 and a shoulder due to centrifugal force. It spreads uniformly on the inner surface of the tire 1 of the portion 3 and the sidewall portion 4, efficiently guides the frictional heat generated in the tread portion 2 and the shoulder portion 3 to the sidewall portion 4, and causes the tread portion 2 and the side surface of the tire 1 outer surface. The wall portion 4 dissipates the frictional heat by forced air cooling with the outside air due to the rotation of the tire 1, and effectively dissipates excess heat. Further, even when stopped, the tire life extending agent 6 remains on the inner surface of the tire 1 of the tread portion 2 and the sidewall portion 4 for a while immediately after the stop, so that the heat dissipation effect by natural air cooling can be efficiently maintained.

A running experiment was conducted in order to demonstrate the effect of the tire life extending agent of the present invention produced by the above method. Under conditions of outdoor temperature of 27 ° C and cloudy weather, a tire life extension agent 6 was injected into the front wheel right tire of a 20-ton dump truck (full load) equipped with a tubeless tire (12R22.5), and the front wheel left tire was used for comparison. Traveled for 1 hour at 50 km / h without injection. Since the temperature of the tire 1 during running cannot be measured, the temperature of each tire 1 cannot be measured for a stop time of 30 minutes after running for 1 hour, so that each tire for a stop time of 30 minutes after running for 1 hour cannot be measured. The temperature of the tread portion 2, the sidewall portion 4, and the wheel 5 of No. 1 was measured every minute.

FIG. 4 is a graph showing temperature measurement data of each part of the tire without injection of the tire life extending agent of the present invention. From the figure, the temperature immediately after the running is stopped is 52.5 ° C. for the sidewall portion 4, 52.5 ° C. for the wheel 5, and 56.7 ° C. for the tread portion 2, and the tread that generates frictional heat due to the dynamic friction with the road surface. The temperature of part 2 is the highest. With the passage of time, the temperature of the wheel 5 gradually decreases due to natural air cooling, but the temperatures of the tread portion 2 and the sidewall portion 4 increase to 15 to 16 minutes, and then decrease sharply. The cause of the rise is that the frictional heat generated in the tread portion 2 and the sidewall portion 4 during running is caused by the forced air cooling with the outside air due to the rotation of the tire 1 in the tread portion 2 and the sidewall portion 4 on the outer surface of the tire 1. It can be seen that the accumulated heat cannot be sufficiently dissipated and becomes accumulated heat, and as soon as it stops and becomes naturally air-cooled, the accumulated heat becomes excessive heat and raises the temperature.

FIG. 5 is a graph showing the temperature measurement data of each part of the tire with the injection of the tire life extending agent of the present invention. From the figure, the temperature immediately after the running stop is 46.0 ° C. for the sidewall portion 4, 54.0 ° C. for the wheel 5, and 56.0 ° C. for the tread portion 2, and the temperature of the tread portion 2 is also the highest here. It has become. However, the temperature of the sidewall portion 4 is considerably lower than that of the tire 1 without injection of the tire life extending agent 6, and the temperatures of the tread portion 2 and the sidewall portion 4 sharply decrease with the passage of time. In minutes, it is about 10 ° C. lower than the temperature of the tire 1 without the injection of the tire life extender 6. The cause of the decrease is that the tire life extender 6 spreads uniformly on the inner surface of the tire 1 of the tread portion 2, the shoulder portion 3 and the sidewall portion 4 due to centrifugal force, and the frictional heat generated in the tread portion 2 and the shoulder portion 3 is efficiently used. The frictional heat is effectively dissipated by forced air cooling in the outside air by the rotation of the tire 1 at the tread portion 2 on the outer surface of the tire 1 and the sidewall portion 4 to effectively dissipate the excess heat. It can be seen that even if the tires are stopped and naturally air-cooled, the tires are not increased because there is no excess heat.

Table 1: In order to obtain the actual heat calories released from each part of the tire, the difference between the tire temperature and the test run outside air temperature of 27 ° C. must be obtained. This is the number required to compare the cooling effects. Then, the number obtained by integrating those numbers is the number in Table 1.

From the temperature measurement data of the tire without the injection of the tire life extension agent of FIG. 4 and the temperature measurement data of the tire with the injection of the tire life extension agent of FIG. 5 in each part of the tread portion 2, the sidewall portion 4 and the wheel 5. Obtain the integrated value for 30 minutes of the temperature obtained by subtracting the outside temperature from the measured temperature sampled and measured every minute, and use the temperature of the tire without injection of the tire life extension agent 6 as a reference for the tire with the injection of the tire life extension agent. The temperature ratio of was calculated.

As a result, by injecting the tire life extending agent 6 of the present invention, a large heat dissipation effect of 43.8% can be obtained in the tread portion 2, and a further higher heat dissipation effect of 44.9% can be obtained in the sidewall portion 4. It was. Further, although the direct influence of the tire life extending agent 6 on the wheel 5 is small, a heat dissipation effect of 11.6% was obtained due to the indirect influence on the tread portion 2 and the sidewall portion 4.

Regarding the puncture prevention function, the following experiments were conducted and good results were obtained. The tire life extender 6 of the present invention is injected into a tube tire of a forklift that allows air to escape immediately when a flat tire is punctured, and after running for several minutes, a nail (length 45 mm, diameter 2.45 mm) is pierced into the tire 1 and the nail is pierced. The tire was left with the puncture hole facing up, and although there was a slight air leak, the proper air pressure could be maintained for one year. Despite the poor condition of the tube tire and the puncture hole placed on the upper part of the tire where the solution drips, good results were obtained over a long period of time, and even better results were obtained with the tubeless tire. It seems that it will be done.

Regarding the occurrence of rust on the wheel 5, the following experiment was conducted and good results were obtained. In consideration of the temperature condition depending on the season, the tire life extender 6 of the present invention is injected into the tire 1 of the truck during the 6 months of summer (May-October) and the 6 months of winter (November-April). When the wheel 5 was inspected after normal use, the modified epoxy resin formed the resin thin film 8 so as to cover the layer of rust 7 on the inner surface of the wheel 5, and no new rust was generated.

Further, the vulcanized rubber which is the material of the tire 1 is a porous substance having a large number of fine pores, and the tire air pressure naturally decreases due to the slight leakage of air from the pores and the leakage of the rim or bead. However, since bentnite closes the pores on the inner surface of the tire 1, the rim and bead leakage prevention by the aramid fine fibers is also added, and the effect of preventing the natural decrease in air pressure is also obtained. The content of the experiment was that when the tire life extender 6 of the present invention was injected into a truck tubeless tire (12R22.5) and used for 6 months from April to September, the air pressure was 900 KPa at the time of injection. However, at the end of the inspection, it was 870 KPa, a decrease of only 3.3%, but for tire 1 without the tire life extension agent 6, it was 790 KPa, a decrease of 12.3%.

1 Tire 2 Tread part 3 Shoulder part 4 Side wall part 5 Wheel 6 Tire life extension agent 7 Rust 8 Resin thin film

Further, the vulcanized rubber which is the material of the tire 1 is a porous substance having a large number of fine pores, and the tire air pressure naturally decreases due to the slight leakage of air from the pores and the leakage of the rim and beads. However, since bentnite closes the pores on the inner surface of the tire 1, the rim and bead leakage are prevented by the aramid fine fibers, and the effect of preventing the natural decrease in air pressure is also obtained. As the content of the experiment, when the tire life extending agent 6 of the present invention was injected into a truck tubeless tire (12R22.5) and used for 6 months from April to September, the air pressure was 900 KPa at the time of injection. However, at the end of the inspection, it was 870 KPa, a decrease of only 3.3%, but for tire 1 without the tire life extender 6, it was 790 KPa, a decrease of 12.3%.
In each of the above explanations, the state of the tire 1 is assumed to be the tire currently in use, but the effect obtained even with a new tire or a rehabilitated tire at the time of tire replacement is the same, and in any state. It may be a tire.

Claims (6)

A tire life extension composition comprising water, ethylene glycol and bentonite as a base material, and the base material alone or a mixture of the base material with either one or both of aramid fine fibers and modified epoxy resin. Agent. When the composition is water, ethylene glycol and bentonite, it is a solution consisting of 47.5 to 45.5% of water, 47.5 to 45.5% of ethylene glycol and 5 to 9% of bentonite (molality). The tire life extending agent according to claim 1, which is characterized by being present. When the composition is water, ethylene glycol, bentonite and aramid fine fibers, the composition is 46.75 to 44% water, 46.75 to 44% ethylene glycol, 5 to 9% bentonite, and 1.5 to 3% aramid fine fibers. The tire life extending agent according to claim 1, wherein the solution comprises a ratio (% by weight). When the composition is water, ethylene glycol, bentonite and a modified epoxy resin, the composition ratio of water 46 to 42.5%, ethylene glycol 46 to 42.5%, bentonite 5 to 9%, and modified epoxy resin 3 to 6% ( The tire life extending agent according to claim 1, wherein the solution is composed of (% by weight). When the composition is water, ethylene glycol, bentonite, aramid fine fibers and modified epoxy resin, water 45.25 to 41%, ethylene glycol 45.25 to 41%, bentonite 5 to 9%, aramid fine fibers 1.5 to The tire life extending agent according to claim 1, wherein the solution comprises a composition ratio (weight% concentration) of 3% and 3 to 6% of a modified epoxy resin. The tire life extending agent according to claim 1, wherein the aramid fine fiber is a fine fiber obtained by grinding 100% aramid fiber with a stone mill type grinder or the like.

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