JP2010042593A - Method of repairing pneumatic tire and repairing material of tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of repairing a pneumatic tire, capable of repairing a damaged part of an inner liner layer of the tire to improve air impermeability and durability, and to provide a tire repairing material used for the method. <P>SOLUTION: In the method of repairing the pneumatic tire T having the inner liner layer 1 on the inner surface of the tire and having the damaged part h<SB>1</SB>on at least the inner liner layer 1, powder 2 (tire repairing material) composed of a thermoplastic resin or a thermoplastic resin elastomer composition obtained by blending the thermoplastic resin with elastomer is sprayed so as to cover the damaged part h<SB>1</SB>of the inner liner layer 1 from the inner surface of the tire, and the sprayed powder is heated and melted to be layered. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for repairing a pneumatic tire and a tire repair material. More specifically, when an inner liner layer provided on the inner surface of a tire is damaged, the damaged portion is improved in air permeation prevention and durability. The present invention relates to a method for repairing a pneumatic tire to be repaired and a tire repair material used therefor.

  As a method in which a pneumatic tire receives a through-hole that has passed from the outer surface of the tire to the inner surface of the tire due to nailing, etc., and the inner liner layer is damaged, Patent Document 1 discloses a method for repairing the inner surface of the tire. A method of attaching a thin film repair material made of a thermoplastic resin with high air permeation resistance to a repair location by an adhesive or welding is proposed.

However, since the thermoplastic resin has a higher elastic modulus than rubber, the material made into a film-like thin film can be affixed to the rubber inner wall surface in the depth direction of the damaged part so as not to embed air. It is difficult, and it becomes easy to cause damage from the bubble as a starting point. In addition, if the thin film repair material is made too thin in order to make it easier to adapt to the damaged part, wrinkles are likely to occur in the thin film repair material when it is applied, and air traps are also likely to occur. For this reason, there has been a problem that the air permeation prevention and durability of the pneumatic tire after repair are not always sufficient.
JP 2006-272809 A

  An object of the present invention is to provide a method for repairing a pneumatic tire and a tire repair material used therefor, in which the damaged portion of the inner liner layer received by the tire can be repaired so as to improve air permeation prevention and durability. It is in.

  A method for repairing a pneumatic tire according to the present invention that achieves the above object is a method for repairing a pneumatic tire having an inner liner layer provided on an inner surface of a tire and having at least a damaged portion in the inner liner layer, wherein A powder made of a thermoplastic resin elastomer composition in which a thermoplastic resin or a thermoplastic resin and an elastomer are blended is sprayed so as to cover the damaged portion of the liner layer, and the sprayed powder is melted by heating to be layered. It is characterized by that.

  When the damaged portion of the inner liner layer is a through hole that has passed through from the tire outer surface to the tire inner surface, the through hole is filled with unvulcanized rubber from the tire outer surface side, and the powder is sprayed on the tire inner surface side. These unvulcanized rubber and powder are preferably heat-treated at the same time.

  The powder may be preliminarily mixed with a tire pressure-sensitive adhesive or liquid unvulcanized rubber and sprayed with the suspension. Moreover, after apply | coating an adhesive agent beforehand to the said damaged part, the said powder can also be sprayed. The heat treatment is preferably performed under conditions of 150 to 250 ° C. and 1 to 10 minutes.

  The thermoplastic resin elastomer composition may be composed of 20 to 80% by weight of a polyamide-based resin and 20 to 80% by weight of an elastomer. The average particle size of the powder is preferably 1 to 100 μm.

  The tire repair material of the present invention that achieves the above object is characterized by comprising a powder made of a thermoplastic resin elastomer composition obtained by blending a thermoplastic resin or a thermoplastic resin and an elastomer.

  The average particle size of the powder constituting the tire repair material is preferably 1 to 100 μm. The tire repair material can also be a suspension in which the powder is mixed with a tire pressure-sensitive adhesive or liquid unvulcanized rubber. The thermoplastic resin elastomer composition may be composed of 20 to 80% by weight of a polyamide-based resin and 20 to 80% by weight of an elastomer.

  According to the method for repairing a pneumatic tire of the present invention, since the tire repair material is made of powder made of a thermoplastic resin or a thermoplastic resin elastomer composition, this is so covered as to cover the damaged portion of the inner liner layer from the tire inner surface. By spraying onto the inner liner layer, air can be easily penetrated in the depth direction of the damaged portion of the inner liner layer, and by heating and melting it, a layer containing no bubbles can be formed. This layer improves the air permeation preventive property of the pneumatic tire after repair, and air does not remain in the interior or wrinkles are not generated, so that the tire durability can be improved.

  According to the tire repair material of the present invention, since it is composed of a powder made of a thermoplastic resin elastomer composition in which a thermoplastic resin or a thermoplastic resin and an elastomer are blended, as described above, air is applied to the damaged portion of the inner liner layer. Can be intruded and adhered so as not to be embraced, and the air permeation prevention and durability of the pneumatic tire after repair can be improved.

  In the tire repair material of the present invention, a thermoplastic resin or a thermoplastic resin elastomer composition obtained by blending a thermoplastic resin and an elastomer is formed as a powder. Since this tire repair material is a powder, even a damaged portion formed in a complicated uneven shape on the inner liner layer is easy to penetrate in the depth direction of the damaged portion by the blowing operation, and air is contained inside. You can avoid embrace. The powder sprayed in this way can be stratified by simply making the powder continuous by heating and melting. Therefore, the damaged part can be filled up so that bubbles and soot are not generated. For this reason, bubbles remaining in the damaged part do not cause breakage, and air leakage does not occur due to soot. Further, since this powder tire repair material is not bulky, it requires less space for storage than a thin film made of thermoplastic resin, and is excellent in storage.

  The powder constituting the tire repair material can be prepared by pulverizing a thermoplastic resin or a thermoplastic resin elastomer composition under an ultra-low temperature state below zero. The average particle size of the powder is preferably 1 to 100 μm, more preferably 10 to 50 μm. When the average particle diameter of the powder is less than 1 μm, it is difficult to sufficiently increase the flying speed at the time of injection, and thus it is difficult to adhere to the damaged portion of the inner liner layer. On the other hand, if the average particle diameter exceeds 100 μm, it becomes difficult to enter the depth direction of the damaged part, and gaps are likely to be formed between the particles. The average particle diameter of the powder means a value defined by a volume average particle diameter obtained using a laser diffraction / scattering particle diameter measuring apparatus.

  In the tire repair material of the present invention, the thermoplastic resin forming the powder is not particularly limited as long as it is a thermoplastic polymer. For example, polyamide resin, polyester resin, polynitrile resin, polymethacrylate Resin, polyvinyl resin, cellulose resin, fluorine resin, imide resin and the like are preferable, and polyamide resin is particularly preferable. Examples of polyamide resins include nylon 6 (N6), nylon 66 (N66), nylon 46 (N46), nylon 11 (N11), nylon 12 (N12), nylon 610 (N610), nylon 612 (N612), nylon Examples thereof include 6/66 copolymer (N6 / 66).

  Further, the thermoplastic resin elastomer composition forming the powder is constituted by blending a thermoplastic resin and an elastomer. As a thermoplastic resin, the thing similar to the thermoplastic resin mentioned above can be used. Examples of the elastomer include diene rubber and hydrogenated product thereof, olefin rubber, halogen-containing rubber [eg brominated product of isobutylene paramethylstyrene copolymer (Br-IPMS)], silicon rubber, sulfur-containing rubber, fluorine rubber, and the like. It can be illustrated.

  The composition ratio of the thermoplastic resin to the elastomer of the thermoplastic resin elastomer composition is not particularly limited, but is preferably 10/90 to 90/10, more preferably 20/80 to 85/15 by weight. Is good. In particular, when a polyamide-based resin is blended, a composition composed of 20-80% by weight of a polyamide-based resin and 20-80% by weight of an elastomer is preferable. By setting the blending ratio of the polyamide resin and the elastomer within the above-mentioned range, a structure in which the elastomer is dispersed as a discontinuous phase is formed in the matrix of the polyamide resin, and the impact resistance is improved by the elastomer. A thermoplastic resin elastomer composition having high gas impermeability can be obtained by the polyamide resin. The repair material composed of this thermoplastic resin elastomer composition is effective in preventing deterioration from the repaired portion.

  In the tire repair material of the present invention, powder may be sprayed alone, but preferably the powder is used as a suspension mixed with a tire adhesive or liquid unvulcanized rubber. By spraying the damaged part as such a suspension, the flying speed of the powder is improved and it is easy to adhere to the damaged part. The mixing amount of the tire pressure-sensitive adhesive or liquid unvulcanized rubber is preferably 5 to 40 parts by weight, more preferably 10 to 20 parts by weight with respect to 100 parts by weight of the powder. By adjusting the mixing amount of the tire pressure-sensitive adhesive or liquid unvulcanized rubber within such a range, it is possible to improve the adhesion workability by injection and to form a continuous layer excellent in air permeation prevention properties. .

  Examples of the tire pressure-sensitive adhesive include paraffin oil, aroma oil, adipate plasticizer, and phosphate plasticizer. Examples of the liquid unvulcanized rubber include liquid butyl rubber and liquid butadiene rubber.

  The method for repairing a pneumatic tire according to the present invention is not limited to repairing a through-hole that has passed from the outer surface of the tire to the inner surface of the tire by nailing or the like. It can also be applied to damage received as such.

  1A to 1C are explanatory views illustrating a method for repairing a pneumatic tire having a through hole from the tire outer surface to the inner surface.

In FIG. 1A, a pneumatic tire T includes an inner liner layer 1 on the inner surface of the tire. The inner liner layer 1 may be made of a rubber composition containing butyl rubber as a main component, or may be made of a thermoplastic resin or a thermoplastic resin elastomer composition. The inner liner layer 1, there is a through hole h ₁ is exited from the tire outer surface to the inner surface of the tire due to stepping nails. The through hole h _{1 is} first filled with the unvulcanized rubber 4 so as to be in close contact with the entire wall surface from the tire outer surface side of the through hole h ₁ . The unvulcanized rubber 4 may be any rubber composition that is normally used as a tire rubber composition having a function of being vulcanized or crosslinked by heating. Moreover, by filling the unvulcanized rubber from the tire outer surface, it is possible to prevent the constituent layers inside the tire such as the inner liner layer and the carcass layer from being damaged as compared with the case of filling from the tire inner surface.

Note that the unvulcanized rubber 4 by the size of the through-holes h ₁ (thickness), may be filled as needed, if the through hole is fine may not fill the unvulcanized rubber . Further, instead of unvulcanized rubber, a vulcanized rubber such as a rubber plug for filling holes may be press-fitted into the through hole, and the protruding portion may be cut.

When finished filling of the unvulcanized rubber is then as shown in FIG. 1 (B), blowing the powder 2 composed of the present invention described above from the tire inner surface side so as to cover the through hole h _1. The powder 2 is sprayed so as to be stacked _{one by one in} the depth direction from the tire inner surface side of the through-hole h1 individually, and the air gap is held between the inner end portion of the previously filled unvulcanized rubber. It is buried so as not to be included. Such an effect can be made more remarkable by adjusting the average particle diameter of the powder 2 to 1 to 100 μm. Moreover by spraying in the pre-adhesive or is applied to the periphery of the through-holes h _1, it was mixed with the powder in an adhesive or a liquid uncured rubber tire suspension as described below, the powder through holes it can be easy to be more attached to the periphery of h _1. The apparatus used for spraying powder is not particularly limited, and a spraying apparatus used for spraying ordinary powder particles can be used.

Finally, as shown in FIG. 1 (C), heat-treated at the same time to press the trowel 10 to the through-holes h unvulcanized rubber 4 and sprayed powder 2 filled in _1. By this heat treatment, the unvulcanized rubber 4 is for vulcanized rubber and vulcanized around the through-hole h _1, to improve the durability of the pneumatic tire after repair. The through-holes h ₁ powder 2 blown to cover the stratified and melted by heating, or air bubbles remaining can wrinkles to form the repair layer 3 which is not or generated. Since the repair layer 3 is made of a thermoplastic resin or a thermoplastic resin elastomer composition, the air permeation coefficient is extremely low, and the air permeation preventive property around the through hole can be improved. Moreover, since the tire after repair has few air leaks from a through-hole, tire durability can be improved further by preventing the oxidative degradation of a tire structural member.

  The conditions of temperature and time when heat-treating the powder and unvulcanized rubber are such that the heating temperature is preferably 150 to 250 ° C, more preferably 170 to 190 ° C, and the heating time is preferably 1 to 10 minutes. Preferably it is good for 5 to 10 minutes. If the heating temperature is less than 150 ° C., the powder may not be melted and layered, or the vulcanized adhesion of unvulcanized rubber may be insufficient. If the heating temperature exceeds 250 ° C., the tire constituent material, powder, and unvulcanized rubber may be thermally deteriorated. If the heating time is shorter than 1 minute, layering of the powder may be incomplete, or vulcanized adhesion of unvulcanized rubber may be insufficient. In addition, when the heating time is longer than 10 minutes, the work efficiency of tire repair decreases.

  During the heat treatment, pressurization may be performed simultaneously. The pressurizing conditions are not particularly limited, but are preferably 100 to 5000 kPa, more preferably 500 to 4000 kPa. By setting the pressure within such a range, the powder can be easily layered and the components of the pneumatic tire such as the inner liner layer and the carcass layer can be prevented from being damaged.

  In the present invention, as described above, it is preferable to apply an adhesive around the through-holes in advance when spraying the powder or suspension thereof. By spraying the powder after the applied adhesive is dried, the powder can be reliably attached to the periphery of the through hole. Examples of the adhesive include an epoxy resin adhesive, an α-olefin adhesive, a urethane adhesive, and a phenol adhesive.

  2A and 2B are explanatory views illustrating an example of a tire repair method when the inner liner layer is damaged such as scratches.

In FIG. 2A, the pneumatic tire T has an inner liner layer 1 on the inner surface of the tire, and a damaged portion h ₂ is present in a part of the inner liner layer 1. In this repair method, as first cover the damaged portion h ₂ of the inner liner layer 1 blows the powder 2 from the inner surface of the tire. This powder 2 is the tire repair material described above. By spraying the powder 2 in the damaged portion h ₂ of the inner liner layer 1, engulfed the case and powder 2 bubbles inside the depth direction from the tire inner surface of the damaged portion h ₂ in the same manner of the embodiment of Figure 1 It penetrates while laminating sequentially so that there is no. Thus, the powder 2 is to cover the inside and periphery of the lesion h _2.

Next, as shown in FIG. 2 (B), heat treatment to press the trowel 10 to powder 2 was sprayed on the damaged portion h _2. This heat treatment may be the same as in the case of FIG. 1, and is preferably performed under conditions of 150 to 250 ° C. and 1 to 10 minutes. Thus since the powder 2 to form the repair layer 3 continuous stratified by melting, to improve the air impermeability of the peripheral portion of the damaged portion h _2. Also, the tire after repair can be further improved tire durability by preventing oxidative deterioration of the tire components the air leakage is reduced from the damaged portion h _2.

  In the tire repair method shown in FIGS. 2 (A) and 2 (B), as in the repair method of FIGS. It is preferable to use a suspension mixed with vulcanized rubber, and it is preferable to spray a tire repair material after applying an adhesive to the damaged part in advance.

  In the tire repair method of the present invention, the powder is sprayed so as to cover the damaged portion of the inner liner layer and heated to be layered, so a thin film for repair made of a thermoplastic resin or a thermoplastic resin elastomer composition is formed. It is simpler than the method of cutting it to the required size and then sticking it to the damaged part of the inner liner layer, and is excellent in air permeation prevention and tire durability.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, the scope of the present invention is not limited to these Examples.

  A pneumatic tire having a tire size of 165SR13 is prepared, and a pneumatic tire having a damaged portion in the inner liner layer is formed by forming a through hole having a diameter of 5 mm that penetrates from the tire tread portion to the inner liner layer using a cutting tool. Produced. In repairing the pneumatic tire having the through hole, after filling the through hole with unvulcanized rubber from the tire outer surface (tread portion) and treating the tire inner surface (in Comparative Example 1, the tire inner surface is treated). 5 types of methods (Examples 1 to 3) in which the treatment method of the tire inner surface and the time for pressing the iron were varied as shown in Table 1 under the common condition that the iron heated to 160 ° C. was pressed. In Comparative Examples 1 and 2, repair was performed to obtain a pneumatic tire after repair.

  In the repair method of Example 3, an adhesive (epoxy resin adhesive, a toluene solution of AT501 manufactured by Daicel Corporation) was applied in advance to the tire inner surface of the through hole, and after the adhesive was dried, the tire repair material 1 Sprayed. In the repair method of Comparative Example 2, an adhesive (epoxy resin adhesive, a toluene solution of AT501 manufactured by Daicel) was applied in advance to the tire inner surface of the through hole, and after the adhesive was dried, a repair thin film was applied. It was.

  Moreover, the unvulcanized rubber, tire repair materials 1 and 2, and the repair thin film used for tire repair in the above Examples and Comparative Examples were prepared by the following methods.

Preparation of unvulcanized rubber A rubber composition having the following composition was weighed with the ingredients except sulfur and a vulcanization accelerator, kneaded for 4 minutes with a 1.7 L Banbury mixer, and a master batch was prepared at a temperature of 160 ° C. Release and cool to room temperature. This master batch was subjected to a 1.7 L Banbury mixer, and sulfur and a vulcanization accelerator were added and mixed to prepare an unvulcanized rubber.
・ Natural rubber (STR-20 manufactured by TECK BEE HANG): 50 parts by weight-Styrene butadiene rubber (Nipol 1502 manufactured by Nippon Zeon Co., Ltd.): 50 parts by weight-Carbon black (Niteron #GN manufactured by Nippon Nihon Carbon Co., Ltd.): 50 parts by weight Parts / terpene resin (manufactured by Yashara Chemical Co., Ltd.): 5 parts by weight anti-aging agent (Antigen 6C, manufactured by Sumitomo Chemical Co., Ltd.): 2 parts by weight, sulfur: (Sanfel manufactured by Sanshin Chemical Industry Co., Ltd.): 3 parts by weight, vulcanization acceleration Agent: (Noxeller CZ-G manufactured by Ouchi Shinsei Chemical Co., Ltd.): 1 part by weight

Preparation of tire repair material and tire repair material 1: Weigh 50% by weight of nylon 6 (Nylon 5033B manufactured by Ube Industries) and bromide of isobutylene paramethylstyrene copolymer (MDX90-10 manufactured by ExxonMobil Chemical). The mixture was kneaded with a biaxial kneader to prepare a thermoplastic resin elastomer composition. The obtained composition was pulverized using a pulverizer (rotor speed mill manufactured by FRITSCH) to obtain a tire repair material 1. When the particle diameter of the tire repair material 1 was measured by the method described above, the average particle diameter was 10 μm.
Tire repair material 2: 10 parts by weight of paraffin oil (G spindle manufactured by Cosmo Oil Co., Ltd.) is mixed with 100 parts by weight of the tire repair material 1 obtained as described above to make the tire repair material 1 into a suspension. The thing was designated as tire repair material 2.

Preparation of thin film for repair 50% by weight of nylon 6 (Nylon 5033B manufactured by Ube Industries) and 50% by weight of bromide of isobutylene paramethylstyrene copolymer (MDX90-10 manufactured by ExxonMobil Chemical) were weighed and biaxially kneaded. A thermoplastic resin elastomer composition was prepared by kneading with a machine. The obtained composition was subjected to an extrusion molding machine to obtain a repair thin film having a thickness of 50 μm.

  The air pressure retention and durability of the pneumatic tire after repair obtained by the repair method described above were evaluated by the following methods, respectively.

Air pressure retention A pneumatic tire after repair is mounted on a rim (15 x 6 JJ), filled with 140 kPa air pressure, applied to an indoor drum tester (drum diameter 1707 mm) in accordance with JIS D4230, and loaded under an atmosphere of 38 ° C. The air pressure after running 100,000 km under the conditions of 5.5 km and speed 80 km / h was measured. The obtained results are shown in Table 1 as an index with the air pressure of Comparative Example 1 as 100. The higher this index is, the better the air permeation preventive property is.

Durability A pneumatic tire after repair is mounted on a rim (15 x 6 JJ), filled with air pressure of 140 kPa, and subjected to an indoor drum tester (drum diameter 1707 mm) in accordance with JIS D4230 in an atmosphere of 38 ° C under JATM regulations. 160% of the load was applied, and the running time until belt failure occurred under the condition of speed 80 km / h was measured. The obtained results are shown in Table 1 as x when the running time until the belt failure occurred was less than the running time of Comparative Example 1, and ○ when the running time exceeded Comparative Example 1.

(A)-(C) is explanatory drawing which shows typically an example of the repair method of the pneumatic tire of this invention, (A) is the process of filling unvulcanized rubber, (B) sprays powder. Step (C) represents a step of heat treatment. (A) (B) is explanatory drawing which shows typically the other example of the repair method of the pneumatic tire of this invention, (A) is the process of spraying powder, (B) represents the process of heat-processing. .

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner liner layer 2 Powder 3 Repair layer 4 Unvulcanized rubber T Pneumatic tire h ₁ Through-hole h ₂ Damaged part of inner liner layer

Claims (11)

  A method for repairing a pneumatic tire having an inner liner layer provided on an inner surface of a tire and having at least a damaged portion in the inner liner layer, wherein the thermoplastic resin or the thermoplastic is covered so as to cover the damaged portion of the inner liner layer from the inner surface of the tire A method for repairing a pneumatic tire, in which a powder made of a thermoplastic resin elastomer composition in which a resin and an elastomer are blended is sprayed, and the sprayed powder is melted by heating to form a layer.   The damaged part of the inner liner layer is a through-hole that has passed from the outer surface of the tire to the inner surface of the tire, and the through-hole is filled with unvulcanized rubber from the outer surface of the tire and the powder is sprayed on the inner surface of the tire The method for repairing a pneumatic tire according to claim 1, wherein the unvulcanized rubber and the powder are heat-treated at the same time.   The method for repairing a pneumatic tire according to claim 1 or 2, wherein the powder is preliminarily mixed with a tire pressure-sensitive adhesive or liquid unvulcanized rubber, and the suspension is sprayed.   The method for repairing a pneumatic tire according to claim 1, 2 or 3, wherein the powder is sprayed after applying an adhesive to the damaged portion in advance.   The method for repairing a pneumatic tire according to any one of claims 1 to 4, wherein the thermoplastic resin elastomer composition comprises 20 to 80% by weight of a polyamide-based resin and 20 to 80% by weight of an elastomer.   The method for repairing a pneumatic tire according to claim 1, wherein an average particle diameter of the powder is 1 to 100 μm.   The method for repairing a pneumatic tire according to any one of claims 1 to 6, wherein the heat treatment is performed under conditions of 150 to 250 ° C and 1 to 10 minutes.   A tire repair material comprising a powder comprising a thermoplastic resin elastomer composition obtained by blending a thermoplastic resin or a thermoplastic resin and an elastomer.   The tire repair material according to claim 8, wherein the powder has an average particle diameter of 1 to 100 μm.   The tire repair material according to claim 8 or 9, wherein the powder is made into a suspension mixed with an adhesive for tires or liquid unvulcanized rubber.   The tire repair material according to claim 8, 9 or 10, wherein the thermoplastic resin elastomer composition comprises 20 to 80% by weight of a polyamide-based resin and 20 to 80% by weight of an elastomer.

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