JP2009138112A - Puncture sealant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly seal even a puncture hole by a relatively thick nail having a diameter exceeding 4 mm, and to easily remove dirt inside a tire caused by an emergency repair by the puncture sealant. A puncture sealant that can be washed away is provided.
As a puncture sealing agent for sealing a hole in a punctured tire, a puncture sealing agent is constituted by containing a water-soluble acrylic resin, an antifreezing agent, resin particles and short fibers.
The content of the water-soluble acrylic resin is preferably 0.3 to 10% by mass, the content of the antifreezing agent is preferably 5 to 60% by mass, and the total content of the resin particles and short fibers is 2 to 10% by mass. Preferably there is.
[Selection figure] None

Description

  The present invention relates to a puncture sealant for sealing a hole in a punctured tire.

  When light puncture occurs in the tire due to a nail or the like, a puncture sealing agent for injecting the inside of the tire and sealing the puncture hole has been proposed for emergency repair (for example, Patent Documents 1 and 2). .

  However, conventional puncture sealants are mainly made of natural rubber latex, or synthetic rubber latex such as synthetic isoprene rubber (IR) or acrylonitrile-butadiene rubber (NBR). Had.

  That is, the puncture sealant mainly composed of rubber latex as described above can quickly seal against a small puncture hole having a diameter of 4 mm or less, but if the puncture hole becomes large, When sealing could not be performed and it took a long time to seal, there was a problem that the puncture sealing agent that continued to be ejected from the puncture hole contaminated the vehicle body and road around the tire.

  In addition, an adhesive film of natural rubber or synthetic rubber is fixed inside the tire that has been repaired with the puncture sealant, which has hindered full-scale repair with a tire patch or the like. In addition, anti-freezing agents are added to enable repair in cold conditions, but the stability of latex is impaired by the addition of anti-freezing agents, so the rubber solids content necessary for stability and sealing of latex In order to ensure this, the addition amount of the antifreezing agent must be kept within a certain range, and therefore, the use limit is around -30 ° C.

Japanese Patent No. 3210863 Japanese Patent No. 3802212

  The present invention solves the problems of the conventional puncture sealant as described above, and even a puncture hole such as a relatively thick nail having a diameter exceeding 4 mm can be quickly sealed, An object of the present invention is to provide a puncture sealing agent that can easily wash away dirt inside a tire caused by emergency repair using the puncture sealing agent.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor, when comprising a puncture sealing agent by containing a water-soluble acrylic resin, an antifreezing agent, resin particles, and short fibers, The present inventors have found that the problem can be solved and have completed the present invention.

  That is, the present invention is a puncture sealing agent for sealing a hole in a punctured tire, characterized in that it contains a water-soluble acrylic resin, an antifreezing agent, resin particles and short fibers. .

  According to the puncture sealing agent of the present invention, even a puncture hole formed by a nail having a diameter of about 6 mm can be quickly sealed. In addition, the puncture sealant of the present invention can easily remove the puncture sealant adhering to the vicinity of the puncture hole by washing with water after sealing the puncture hole, so that it does not hinder full-scale repair with a tire patch or the like. . Furthermore, the puncture sealant of the present invention can be used even at a low temperature of −40 ° C. As a result, the usable temperature range can be expanded to a wide range of −40 ° C. to + 70 ° C.

  As described above, the puncture sealing agent of the present invention contains four components of water-soluble acrylic resin, antifreezing agent, resin particles, and short fibers as essential components. The resin particles and the short fibers work as a plugging material for preventing the air from puncturing and causing air (air) leakage from the puncture hole. Water-soluble acrylic resin works as a thickener to disperse those occlusive materials in a stable state, but because it is water-soluble, it will end the role of emergency repair and attempt full-scale repairs with tire patches etc. In this case, it can be easily removed by washing with water.

  This water-soluble acrylic resin can be obtained by neutralizing a commercially available alkali-soluble acrylic resin emulsion with an alkali. As a commercially available product of the alkali-soluble acrylic resin emulsion as described above, for example, an alkali-soluble acrylic acid ester copolymer emulsion is marketed under the trade name “Boncoat VE” from Dainippon Ink and Chemicals, Inc. This “Boncoat VE (trade name)” is itself a low-viscosity, smooth emulsion, but when used, it can be neutralized by adding an alkali to obtain a desired high viscosity. it can. Examples of the alkali include organic amines such as ammonia and triethanolamine, and alkali metal hydroxides such as sodium hydroxide and potassium hydroxide. These alkalis are alkali-soluble acrylic resins. In neutralizing the emulsion, it is preferable to make it into an aqueous solution in advance. The water-soluble acrylic resin may be used for the preparation of the puncture sealing agent in a state where the alkali-soluble acrylic resin emulsion is neutralized with an alkali in advance to prepare a water-soluble acrylic resin. Moreover, it is good also as a water-soluble acrylic resin by adding an alkali in the state which mixed the alkali-soluble acrylic resin emulsion with the other component, and carrying out alkali neutralization. In view of workability, the latter is preferable. In other words, since the alkali-soluble acrylic resin emulsion has a low viscosity and can be easily mixed with other components, the alkali-soluble acrylic resin emulsion having a low viscosity is mixed with other components in advance, and an alkali is added to the mixture to When the water-soluble acrylic resin is made thicker, the workability is better than the preparation of the puncture-sealant using the water-soluble acrylic resin whose viscosity is already high.

  As content in the puncture sealing agent of the said water-soluble acrylic resin, 0.3-10 mass% as solid content, Especially 0.4-7 mass% is preferable. When the content of the water-soluble acrylic resin is less than the above, it becomes difficult to hold the occlusion material such as resin particles and short fibers in a dispersed state, and when the content of the water-soluble acrylic resin is higher than the above, the puncture sealing agent There is a possibility that the workability at the time of injecting the puncture sealing agent from the valve into the tire will deteriorate.

  The puncture sealant of the present invention contains the above four components based on water, or its liquidity is in the range of pH 5 to 9 as a standard for discharging waste liquid after washing to the sewer. It is preferable to keep it.

  Further, since the puncture sealant may come into contact with the steel belt of the tire or the wheel made of iron or aluminum, it is more preferable to keep the pH in the range of 6 to 8 in order not to corrode them. .

  The resin particles and short fibers as the plugging material preferably have various particle sizes, lengths, shapes, etc. in order to quickly close and seal puncture holes of various shapes and sizes, and their contents Is preferably 2 to 10% by mass, particularly 4 to 7% by mass in total of resin particles and short fibers. That is, when the content of the blocking material is less than the above, the puncture hole cannot be sufficiently closed and sealed, and when the content of the blocking material is higher than the above, the blocking material is included in the puncture sealing agent. They may be entangled with each other and workability when the puncture sealing agent is injected into the tire from the valve may be deteriorated.

  In order for the resin particles as the plugging material to remain in the puncture hole and efficiently seal the puncture hole, the shape thereof is preferably irregular (that is, not uniform).

  For example, those having a uniform shape such as a bead shape or the same cylindrical shape are not suitable for sealing by sealing the puncture holes because they are not sufficiently caught between the resin particles or the peripheral portion of the puncture holes. The specific gravity of the resin particles is preferably in the range of 1.0 to 1.4. When the specific gravity is smaller (that is, lighter) than this, it floats in the puncture sealant, and when the specific gravity is larger than this (that is, when it is heavier), it precipitates in the puncture sealant and is easily separated. And it is preferable that the particle size of this resin particle is a wide distribution range so that it can respond to various puncture hole diameters.

  However, if the resin particles are too small, it becomes difficult to seal the puncture holes, and if the resin particles are too large, the resin particles may clog the supply valve. Therefore, the particle size of the resin particles is about 0.05 to 1 mm. It is preferable that The particle size of the resin particles is a value estimated from the scale of the optical micrograph.

  The material of the resin particles is preferably, for example, polyester resin or polyamide resin, particularly PET (polyethylene terephthalate) resin or nylon 12, but is not limited thereto, and examples thereof include polycarbonate resin, methacrylic resin, polystyrene resin, and ABS. Resin, vinyl chloride resin, polyurethane resin may be used, and nylon 6 and nylon 66 may be used as the polyamide resin.

  Short fibers can be used in combination with straight short fibers, crimped short fibers, and short fibers (hereinafter referred to as “fiber powder” according to the common name) called finer fiber powder. preferable. The straight short fibers together with the resin particles form a skeleton of the occluding material, and the shrunken fibers help entangle the occluding materials. Moreover, fiber powder has the effect of filling those gaps. The straight short fiber is not particularly limited to a specific material, but is preferably a polyamide resin type such as nylon 6, and has a length distribution as a shortened short fiber and fine fiber powder. Large cellulosic materials are preferred. The length of the short fiber is preferably 10 mm or less in order to prevent the fibers from being entangled with each other in the puncture sealant, and 7 mm at the longest to obtain the best balance in dispersibility and sealability. The average length is preferably 0.05 to 6 mm, particularly 3 to 5 mm.

  In the present invention, resin particles and short fibers are used as the plugging material. When the puncture sealing agent injected into the tire flows out of the puncture holes, the resin particles first remain in the puncture holes, and the short fibers This is because a plug-like body that entangles and closes and seals the puncture hole is formed, whereby the puncture hole can be tightly sealed.

  And as a ratio of the resin particle and short fiber which comprises this obstruction | occlusion material, it is preferable that it is resin particle: short fiber = 2: 3-3: 2 by mass ratio.

  When the ratio of the resin particles is smaller than the above, when the puncture sealing agent flows out of the puncture holes, the probability that the resin particles stay in the puncture holes is reduced, so that the short fibers are not entangled with the resin particles, and the puncture sealing agent May continue to flow out of the puncture hole, if the ratio of the resin particles is more than the above, it is not possible to make a strong seal due to the entanglement of short fibers, but once sealed, by bending of the tire during running, The seal state may be destroyed and air may leak out.

  In the present invention, the short fibers are preferably used in combination of straight short fibers, crimped short fibers, and finer fiber powders, but as such, straight short fibers, crimped short fibers and fibers. In the case of using in combination with powder, the ratio is preferably a straight short fiber: crimped short fiber: fiber powder = 1: 0.8: 5 to 1: 1.2: 10 in terms of mass ratio. That is, by mass ratio, the short fibers shrunk with respect to the straight short fibers 1 are 0.8 to 1.2 (straight short fibers: crimped short fibers = 1: 0.8 to 1.2), straight fibers. The range of 5 to 10 fiber powder (short straight fiber: fiber powder = 1: 5 to 10) with respect to the short fiber 1 is preferable. If the ratio of straight short fibers is less than the above, it will be difficult to entangle the short fibers with the resin particles that initially stayed in the puncture holes, and the puncture sealant may continue to flow out of the puncture holes. When the ratio of the short fibers is larger than the above, it may be difficult to inject the puncture sealing agent from the valve into the tire due to the entanglement between the resin particles and the short fibers in the puncture sealing agent before injection. When the ratio of the crimped short fibers is smaller than the above, the plug-like body formed by the entanglement between the resin particles and the straight short fibers cannot be firmly solidified, and the plug-like body is caused by bending of the tire during running. If the ratio of the shrunken fibers is higher than the above, the puncture may occur due to the entanglement between the resin particles and the short fibers in the puncture sealant before injection. It may be difficult to inject the sealing agent from the valve into the tire. When the ratio of the fiber powder is less than the above, the gap between the plug-like bodies formed by the entanglement between the resin particles and straight short fibers or crimped short fibers cannot be completely filled with the fiber powder. If the ratio of fiber powder is higher than the above, an increase in the effect of fiber powder cannot be obtained, and the cost increases because fiber powder is an expensive material. It becomes a factor of.

  The antifreezing agent is added for the purpose of preventing the puncture sealing agent from freezing and becoming unusable in winter. As this antifreeze, it is preferable to use propylene glycol which is less harmful to the human body and the environment, but diethylene glycol, monoethylene glycol and the like can also be used. The content of the antifreezing agent in the puncture sealing agent is preferably 5 to 60% by mass, particularly preferably 30 to 60% by mass.

  If the content of the anti-freezing agent in the puncture sealing agent is less than the above, the puncture sealing agent may freeze and become unusable in winter, and the content of the anti-freezing agent in the puncture sealing agent may be If it is more, it can be used at a temperature lower than −40 ° C., but it is not necessary for practical use, and there is no point in increasing the content of the antifreezing agent further. In addition, it is preferable to adjust the usage amount (content of the puncture sealing agent) of the antifreezing agent within the above range according to the climate of the region where the puncture sealing agent is used. When making it into object, it is preferable to set it as content of 50 mass% or more in a puncture sealing agent.

  The puncture sealing agent of the present invention preferably has a viscosity at 20 ° C. of 1,000 to 15,000 mPa · s. When the viscosity of the puncture sealant is lower than the above, the blocking material settles and separates faster, and when the puncture sealing agent is injected into the tire, the blocking material in the puncture sealing agent settles and separates and reaches the puncture hole. If the viscosity of the puncture sealant is higher than the above, it may be difficult to inject the puncture sealant into the tire. Viscosity increases as the temperature decreases and it becomes difficult to inject the puncture sealant into the tire. Therefore, when targeting cold regions, the viscosity at 20 ° C. may be 1,000 to 3,000 mPa · s. preferable. In the present invention, the viscosity of the puncture sealant is measured with a B-type viscometer.

  As described above, the puncture sealing agent of the present invention is configured to contain a water-soluble acrylic resin, an antifreezing agent, resin particles, and short fibers for products that are not intended for extremely cold regions. If the viscosity is not lowered significantly, there is a risk of lacking practicality. In that case, due to a significant decrease in viscosity, the plugging material consisting of resin particles and short fibers may settle and separate in the puncture sealant, but in that case, it should be shaken before use and mixed uniformly. Good. Moreover, when there exists a possibility that the obstruction | occlusion material may settle in that way, a part of water-soluble acrylic resin can be replaced with bentonite for the purpose of delaying the sedimentation. Bentonite has a thickening effect similar to water-soluble acrylic resins, but it has thixotropic properties, so fluidity increases by shaking the puncture sealant containing bentonite well before use, and further injection into the tire. Can be easily.

  As content in the puncture sealing agent of bentonite as the above viscosity reducing agents, 0.5-5 mass% is preferable. When the content of bentonite is less than the above, the settling material consisting of resin particles and short fibers settles faster, and the puncture hole may not be sealed, and the content of bentonite is higher than the above. In such a case, the viscosity may become too high and it may be difficult to inject the puncture sealant into the tire.

  The puncture sealing agent of the present invention may further contain a rust inhibitor such as triethanolamine, an antifoaming agent, a preservative and the like.

  As a puncture repair method using the puncture sealing agent of the present invention as described above, a known method can be applied. That is, the valve core is removed from the valve of the punctured tire, the hose of the container filled with the puncture sealing agent is connected to the valve port, and the puncture sealing agent is injected into the tire. Thereafter, a valve core is attached, filled with air, and adjusted to a prescribed internal pressure.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to them. In the following, “%” indicating concentration and content is based on “mass%” unless otherwise specified.

Example 1
The puncture sealant of Example 1 was prepared with the composition shown in Table 1. In addition, the amount of each component shown in Table 1 is an amount as a solid content, and this is the same in the following tables showing the composition of the puncture sealing agent. And the puncture sealing agent of Example 1 prepared in this way had a viscosity of 1,500 mPa · s at 20 ° C. and a pH of 8.

  The water-soluble acrylic resin used in the preparation of the puncture sealant of Example 1 was Boncoat VE (a product of an alkali-soluble acrylate copolymer emulsion having a solid content concentration of 30% manufactured by Dainippon Ink & Chemicals, Inc. Name) was added and neutralized with an aqueous solution of triethanolamine to generate and increase the viscosity. However, the water-soluble acrylic resin was produced and thickened by mixing the Boncoat VE (trade name) with other components and then adding a triethanolamine aqueous solution thereto. Propylene glycol is used as the antifreeze agent. The PET particles are ester particles # 40A (trade name) manufactured by Sanyo Chemical Co., Ltd. The nylon 12 particles are nylon 12P3014U (trade name) manufactured by Ube Industries, Ltd. Nylon 6 short fiber is a nylon raw yarn 6 denier 3 mm cut product manufactured by Hashimoto Co., Ltd., and this nylon 6 short fiber is straight and its length is cut to 3 mm. The cellulose short fiber is a pure parf manufactured by Sanyo Kasei Co., Ltd., and the length is cut to 5 mm. However, since it is shrunk, the length in the shrunken state is unknown. Cellulose fiber powder is KC Flock W-50 (trade name) manufactured by Nippon Paper Chemicals. The total amount of PET particles and nylon 12 particles as resin particles is 3.67% of the whole puncture sealant, and the total amount of nylon 6 short fibers, cellulose short fibers and cellulose fiber powder is the whole puncture sealant. It is 2.94% of the total, and 6.61% of the whole plugging material composed of resin particles and short fibers. The ratio of the resin particles to the short fibers is, by mass ratio, resin particles: short fibers≈55.5: 44.5, and the ratio of the straight short fibers to the short fibers in the short fibers and the crimped short fibers to the fiber powder is: In terms of mass ratio, straight short fibers: crimped short fibers: fiber powder≈1: 1: 5.95.

  As Bentonite, Hogel Co., Ltd. Wengel HVP (trade name of a bentonite refined product) is used, Triethanolamine is used as a rust preventive agent, and BYK021 manufactured by BYK-Chem BmbH (Product) is used as an antifoaming agent. Name, 10% aqueous solution).

Comparative Example 1
A commercially available puncture sealant mainly composed of natural rubber and propylene glycol was used as the puncture sealant of Comparative Example 1.

Comparative Example 2
A commercially available puncture sealant mainly composed of natural rubber and ethylene glycol was used as the puncture sealant of Comparative Example 2.

  About the puncture sealing agent of Example 1 and the puncture sealing agents of Comparative Examples 1 and 2 prepared as described above, (1) Puncture hole sealability [Puncture hole sealability (A) and puncture hole seal] (B)], (2) cleaning workability, and (3) injection workability were evaluated. The results are shown in Tables 2-3. In addition, those test methods are as follows.

(1) -1 Puncture hole sealability (A)
As a test tire, an automobile tire 195 / 65R14 (nominal width of cross section: 195 mm, nominal ratio of flatness: 65, tire structure symbol: radial, nominal diameter of rim: 14 inches) is used. The puncture hole sealability of the agent was examined using a drum tester for tire running test.

  This drum tester has a mechanism capable of realizing a state close to running by rotating the drum while pressing the tire at a position of 270 ° clockwise from the top of an iron drum having a diameter of 1707.6 mm. A screw nail (4 to 6 mm in diameter is used as a screw nail for the test) is placed at a position of 270 ° in the clockwise direction from the top of the drum so that the tip thereof faces the outer side in the radial direction of the drum. When the tire is pressed against the nail, a puncture hole is formed in the tread at a position of 90 ° in the clockwise direction from the top of the tire. Rotate the tire by a quarter turn by hand so that the puncture hole comes to the position of 180 ° C clockwise from the apex (that is, by doing so, the puncture hole is directly below) Then, remove the valve core from the valve of the punctured tire, connect the hose of the injector filled with the puncture sealing agent to the valve port, inject 450 ml of the puncture sealing agent into the tire, and then fill the tire with air The puncture sealant moves toward the puncture hole and eventually seals the puncture hole while being ejected from the puncture hole. The puncture hole sealability (A) was evaluated by the ejection time and ejection amount of the puncture sealing agent. The results are shown in Table 2.

(1) -2 Puncture hole sealability (B)
After filling the tire with the puncture hole sealed in the puncture hole sealability (A) test (that is, the tire where the puncture sealant injection stopped) with the internal pressure adjusted to 200 kPa, the screw nail is removed from the drum. Remove the tire, press the tire filled with the above-mentioned puncture hole and fill it with air, and run it for 200 km under the conditions of a load of 4 km and a running speed of 100 km / hr. After running, the tire internal pressure was measured, and soap water was applied to the puncture hole to check for air leaks. The results are shown in Table 2.

(2) Cleaning workability The inside of the tire after the running test is washed with water, and it is evaluated whether it is easy to remove the solid content of the puncture sealant. The results are shown in Table 2. When cleaning the inside of the tire after the running test, first remove the wheel from the tire after the running test and scoop out the liquid puncture sealant in the tire (if the punctured sealant is poured into The puncture sealant adhering to the inner surface of the tire was washed off with running water to see if it was easy to remove. The results are shown in Table 2 as “easy” or “difficult”.

(3) Injection workability:
The puncture sealant was injected and repaired into the tire in an environment of -40 to + 70 ° C. The puncture sealant and the tire were left in the environment for 20 hours and brought to the same temperature as the environment. The injection amount of the puncture sealing agent at that time was 450 ml, and it was examined whether injection was possible. The results are shown in Table 3.

  As shown in Table 2, regarding the puncture hole generated by the nail having a diameter of 4 mm, the puncture sealant of Example 1 and Comparative Examples 1 and 2 are both puncture hole sealability (A) and puncture hole sealability (B). However, in the case of a puncture hole formed by a nail having a diameter of 6 mm, the puncture sealant of Example 1 has a short ejection time, and the amount of ejection is also small. Although there were few, the puncture sealing agent of Comparative Examples 1-2 was longer than the puncture sealing agent of Example 1, and the ejection amount was also large.

  Regarding the cleaning workability, the puncture sealing agent of Example 1 was easy to clean regardless of the size of the puncture hole, but the puncture sealing agents of Comparative Examples 1 and 2 were affected by the size of the puncture hole. The cleaning workability was poor.

  That is, the puncture sealant of Example 1 can seal within 1 second not only to the puncture hole generated by the 4 mm diameter nail but also to the puncture hole generated by the 6 mm diameter nail, Moreover, the leakage of the puncture sealing agent (the amount of the puncture sealing agent ejected) generated when sealing the puncture hole was only about 1 ml. In addition, the puncture hole sealed with the puncture sealant of Example 1 has no air leakage during and after traveling, even if it is a large puncture hole generated by a nail having a diameter of 6 mm. This puncture sealant can be easily removed by washing with water, so it has been confirmed that it is suitable as an emergency repair agent before full-scale repairs using tire patches.

  Furthermore, it was confirmed that the puncture sealing agent of Example 1 can be used in a wide temperature range of −40 ° C. to + 70 ° C. as shown in Table 3.

Example 2
The puncture sealant of Example 2 was prepared with the composition shown in Table 4. And the puncture sealing agent of Example 2 prepared in this way had a viscosity of 11,000 mPa · s at 20 ° C. and a pH of 8.

  The water-soluble acrylic resin used in the preparation of the puncture sealing agent of Example 2 was generated and thickened by adding a sodium hydroxide aqueous solution to the same Boncoat VE (trade name) as in Example 1 and neutralizing it. The water-soluble acrylic resin was produced and thickened by mixing Boncoat VE (trade name) with other components in the same manner as in Example 1, and then adding an aqueous sodium hydroxide solution thereto. It was done by doing. Propylene glycol is used as the antifreeze agent. The PET particles are the same ester particles # 40A (trade name) as in Example 1, and the nylon 6 short fiber is a 3 mm cut product of the same nylon raw yarn 6 denier as in Example 1. This nylon 6 short fiber is straight. The length is cut to 3 mm. The cellulose short fiber is the same pure parf as in Example 1 and the length is cut to 5 mm. However, since it is shrunk, the length in the shrunken state is unknown. Cellulose fiber powder is the same KC floc W-50 (trade name) as in Example 1. The blending amount of the PET particles as the resin particles is 2.74% in the whole puncture sealing agent, and the total amount of nylon 6 short fiber, cellulose short fiber and cellulose fiber powder is 3.46% in the whole puncture sealing agent. It is 6.2% in the whole plugging material composed of resin particles and short fibers. The ratio of the resin particles to the short fibers is, by mass ratio, resin particles: short fibers≈44.2: 55.8, and the ratio of the straight short fibers to the short fibers in the short fibers and the crimped short fibers to the fiber powder is: In terms of mass ratio, straight short fibers: crimped short fibers: fiber powder≈1: 1: 7.6.

  And as a rust preventive agent, the triethanolamine is used similarly to Example 1, and the antifoaming agent is also using BYK021 (brand name) similarly to Example 1.

  About the puncture sealing agent of Example 2 prepared as described above, as in Example 1, (1) Puncture hole sealability [puncture hole sealability (A) and puncture hole sealability (B)], (2) Washing Workability and (3) injection workability were evaluated. The results are shown in Tables 5 and 6 together with the results of the puncture sealing agents of Comparative Examples 1 and 2.

  As shown in Table 5, the puncture sealant of Example 2 is similar to the puncture sealant of Example 1 as well as the puncture generated by the nail having a diameter of 6 mm as well as the puncture hole generated by the nail having a diameter of 4 mm. The hole can be sealed within 1 second, and the leakage of the puncture sealant (the amount of the puncture sealant ejected) generated when sealing the puncture hole is only about 1 ml, and the puncture hole is large. As a result, the superiority of the puncture sealing agents of Comparative Examples 1 and 2 was evident with respect to the sealing performance of the puncture holes.

In addition, the puncture hole sealed with the puncture sealant of Example 2 does not leak air during and after running, even if it is a large puncture hole caused by a 6 mm nail. Similarly to the puncture sealant of Example 1, the puncture sealant 2 can be easily removed by washing with water, so it is suitable as an emergency repair agent prior to full-scale repair with a tire patch or the like. The superiority of the puncture sealing agents of Comparative Examples 1 and 2 was obvious.
However, unlike the puncture sealant of Example 1, the puncture sealant of Example 2 was not suitable for use at -40 ° C. as shown in Table 6 because it was not a product for extremely cold regions. It was confirmed that it could be used in a wide temperature range from -10 ° C to + 70 ° C.

Claims (9)

  A puncture sealing agent for sealing a hole in a punctured tire, comprising a water-soluble acrylic resin, an antifreezing agent, resin particles and short fibers.   The content of the water-soluble acrylic resin is 0.3 to 10% by mass as the solid content, the content of the antifreezing agent is 5 to 60% by mass, and the total content of the resin particles and the short fibers is 2 to 10% by mass. The puncture sealing agent according to claim 1, wherein   The puncture sealing agent according to claim 1 or 2, wherein the resin particles are particles of a polyester resin and / or a polyamide resin.   The puncture sealing agent according to any one of claims 1 to 3, wherein the resin particles have an irregular shape.   The puncture sealing agent according to any one of claims 1 to 4, wherein the short fiber is a short fiber of cellulose and / or polyamide fiber.   The puncture sealing agent according to any one of claims 1 to 5, wherein the short fibers are a mixture of straight short fibers, crimped short fibers, and finer fiber powder.   The length of a short fiber is 0.01-10 mm, The puncture sealing agent in any one of Claims 1-6.   Furthermore, the puncture sealing agent in any one of Claims 1-7 containing a bentonite.   The puncture sealing agent according to claim 8, wherein the bentonite content is 0.5 to 5 mass%.