JP6848744B2 - Pneumatic tires - Google Patents

Description

The present invention relates to a pneumatic tire.

As a pneumatic tire having a puncture prevention function (hereinafter, the pneumatic tire is also simply referred to as a tire), a sealant tire in which a sealant material is applied to the inner peripheral surface of the tire is known. In sealant tires, the holes formed during a puncture are automatically closed by the sealant material.

As a method for manufacturing a sealant tire, a method or a batch method in which an organic solvent is added to the sealant material to reduce the viscosity and easy to handle is attached to the inner surface of the tire, and the organic solvent is removed from the diluted sealant material after the attachment. A method of mixing a main agent and a curing agent prepared by a formula kneading device using a static mixer or a dynamic mixer to prepare a sealant material and then attaching it to the inner peripheral surface of a tire (for example, Patent Document 1) is known. Has been done.

Attempts have also been made to form a sealant layer by continuously spirally applying a string-shaped sealant material to the inner peripheral surface of a tire, or to form a two-layer sealant layer (for example). , Patent Document 2).

Special Table 2010-528131 Special Publication No. 60-2203

As a result of diligent studies by the present inventor, the following has been found.
A sealant layer formed by continuously applying a string-shaped sealant material to the inner peripheral surface of a tire, that is, a substantially string-shaped sealant layer that is continuously arranged in a spiral shape along the inner peripheral surface of the tire. In the sealant layer composed of a string-shaped sealant material, when a foreign substance causing a puncture (for example, a nail having a diameter of 5 mm and a length of 60 mm) is pierced into a tire, the punctured portion is the boundary surface between adjacent sealant materials (for example, a nail having a length of 60 mm). If it is an adhesive surface), the boundary surface portion between adjacent sealant materials may be torn in the circumferential direction, making it impossible to seal. In particular, since the sealant material in a low temperature state has a high viscosity, if a foreign substance causing a puncture sticks to the interface between adjacent sealant materials in a low temperature state, it is more likely to tear in the circumferential direction, and the sealing performance may be deteriorated.
That is, in the sealant layer composed of the substantially string-shaped sealant materials continuously spirally arranged along the inner peripheral surface of the tire, when a foreign substance causing a puncture is stuck in the boundary surface between the adjacent sealant materials. , There is a risk of tearing, and good tear resistance of the sealant layer may not be obtained.

The present invention solves the above-mentioned problems, and even if the sealant layer is composed of a substantially string-shaped sealant material continuously spirally arranged along the inner peripheral surface of the tire, the sealant layer has tear resistance. The purpose is to provide excellent pneumatic tires.

The present invention is a pneumatic tire having a sealant layer inside the inner liner in the radial direction of the tire.
The sealant layer has a structure in which the first sealant layer and the second sealant layer are laminated in this order from the inner liner side.
The first sealant layer is composed of a substantially string-shaped sealant material that is continuously spirally arranged along the inner peripheral surface of the tire.
The second sealant layer is composed of a substantially string-shaped sealant material which is continuously spirally arranged along the first sealant layer.
The sealant material constituting the first sealant layer and the sealant material constituting the second sealant layer are arranged in the same circumferential direction and are arranged so as to be offset in the tire width direction (pneumatic tire (). Sealant tires).

The sealant material forming the first sealant layer and the sealant material forming the second sealant layer have substantially the same width W and are 2 mm to 5 mm, and form the first sealant layer. _{It is preferable that the deviation d gap} between the sealant material and the sealant material constituting the second sealant layer in the tire width direction satisfies the following formula.
[W / 4] ≤d _gap ≤ [W / 2]

It is preferable that the first sealant layer and the second sealant layer have different viscosities.

It is preferable that the viscosity of the first sealant layer is lower than the viscosity of the second sealant layer.

It is preferable that the thickness of the first sealant layer and the thickness of the second sealant layer are different.

The present invention is a pneumatic tire having a sealant layer inside the inner liner in the tire radial direction, wherein the sealant layer is laminated in this order from the inner liner side. The first sealant layer is composed of a substantially string-shaped sealant material continuously spirally arranged along the inner peripheral surface of the tire, and the second sealant layer is the first sealant layer. It is composed of a substantially string-shaped sealant material continuously spirally arranged along one sealant layer, and the sealant material constituting the first sealant layer and the sealant material constituting the second sealant layer. Since the sealant material is a pneumatic tire (sealant tire) arranged in the same circumferential direction and shifted in the tire width direction, it is continuously arranged in a spiral shape along the inner peripheral surface of the tire. Even if the sealant layer is made of a substantially string-shaped sealant material, the sealant layer has excellent tear resistance.

It is explanatory drawing which shows typically an example of the coating apparatus used in the manufacturing method of a sealant tire. It is an enlarged view near the tip of the nozzle which constitutes the coating apparatus shown in FIG. It is explanatory drawing which shows typically the positional relationship of the nozzle with respect to a tire. It is explanatory drawing which shows typically an example of the state in which the sealant material of a substantially string shape is continuously attached to the inner peripheral surface of a tire in a spiral shape. It is an enlarged view near the tip of the nozzle which constitutes the coating apparatus shown in FIG. It is explanatory drawing which shows typically an example of the sealant material attached to the sealant tire. It is explanatory drawing which shows typically an example of the manufacturing equipment used for the manufacturing method of a sealant tire. It is explanatory drawing which shows typically an example of the cross section of the sealant material when the sealant material of FIG. 4 is cut by the straight line AA orthogonal to the coating direction (length direction) of the sealant material. It is explanatory drawing which shows an example of the cross section of a pneumatic tire schematically. It is a graph which shows the outline of an example of the result of having measured the steady flow shear viscosity of a sealant material. It is explanatory drawing which shows an example of the 1st sealant layer and the 2nd sealant layer schematically. It is explanatory drawing which shows an example of the 1st sealant layer and the 2nd sealant layer schematically. It is explanatory drawing which shows typically the behavior of the 1st sealant layer and the 2nd sealant layer when a tire is punctured by a nail. It is explanatory drawing which shows typically the behavior of the 1st sealant layer and the 2nd sealant layer when a tire is punctured by a nail.

The pneumatic tire of the present invention is a pneumatic tire having a sealant layer inside in the tire radial direction of the inner liner, and the sealant layer is from the inner liner side, and the first sealant layer and the second sealant layer are in this order. The first sealant layer has a laminated structure, and the first sealant layer is composed of a substantially string-shaped sealant material continuously spirally arranged along the inner peripheral surface of the tire, and the second sealant layer. Is composed of a substantially string-shaped sealant material continuously spirally arranged along the first sealant layer, and the sealant material constituting the first sealant layer and the second sealant layer. The sealant material constituting the tire is a pneumatic tire (sealant tire) arranged in the same circumferential direction and shifted in the tire width direction.

As described above, the sealant layer formed by continuously applying a string-shaped sealant material to the inner peripheral surface of the tire in a spiral shape, that is, continuously spirally along the inner peripheral surface of the tire. In the sealant layer composed of the arranged substantially string-shaped sealant materials, when a foreign substance causing puncture (for example, a nail having a diameter of 5 mm and a length of 60 mm) pierces the tire, the punctured parts are adjacent to each other. If it is the boundary surface (adhesive surface) of the sealant, the boundary surface between the adjacent sealant materials may be torn in the circumferential direction, and it may not be possible to seal the sealant materials. If it is stuck in the boundary surface of the tire, it may be more easily torn in the circumferential direction, and the sealing performance may be deteriorated. That is, in the sealant layer composed of the substantially string-shaped sealant materials continuously spirally arranged along the inner peripheral surface of the tire, when a foreign substance causing a puncture is stuck in the boundary surface between the adjacent sealant materials. , There is a risk of tearing, and good tear resistance of the sealant layer may not be obtained.

As a result of further diligent studies on the problem newly discovered by the present inventor, the following findings were obtained.
The sealant layer has a structure in which the first sealant layer and the second sealant layer are laminated in this order from the inner liner side, and the first sealant layer is continuously spirally formed along the inner peripheral surface of the tire. It is composed of the substantially string-shaped sealant material arranged, and the second sealant layer is composed of the substantially string-shaped sealant material continuously spirally arranged along the first sealant layer. In the case where the sealant material forming the first sealant layer and the sealant material forming the second sealant layer are the sealant layers arranged in the same circumferential direction, the following (i), (Ii) will be described separately.
(I)
When the sealant material forming the first sealant layer and the sealant material forming the second sealant layer are arranged (aligned) in the tire width direction (see FIG. 13A). , In the first sealant layer and the second sealant layer, the boundary surface portion between adjacent sealant materials exists at the same position in the tire width direction, and a puncture-causing foreign substance sticks to the boundary surface between adjacent sealant materials. (See FIG. 13 (b)) In both the first sealant layer and the second sealant layer, the boundary surface portion between the adjacent sealant materials is torn in the circumferential direction, and as a result, the sealant material is contained in the foreign matter causing a puncture. It may not adhere and may not be able to be sealed (see FIG. 13 (c)).
(Ii)
On the other hand, when the sealant material forming the first sealant layer and the sealant material forming the second sealant layer are arranged so as to be offset in the tire width direction (see FIG. 13D), the first In the sealant layer and the second sealant layer, the boundary surface portion between the adjacent sealant materials does not exist at the same position in the tire width direction, and the foreign matter causing a puncture is the boundary surface between the adjacent sealant materials of any of the sealant layers. (See FIG. 13E), the other sealant layer can prevent the boundary surface between adjacent sealant materials from tearing in the circumferential direction, and as a result, the other sealant layer. The sealant material adheres to the puncture-causing foreign substance, and the sealant material can be pulled by the puncture-causing foreign substance to be suitably sealed (see FIG. 13 (f)).

As described in (ii) above, the pneumatic tire of the present invention is a pneumatic tire having a sealant layer inside in the tire radial direction of the inner liner, and the sealant layer is formed from the inner liner side to the first sealant layer and The second sealant layer has a structure in which the second sealant layer is laminated in this order, and the first sealant layer is composed of a substantially string-shaped sealant material which is continuously spirally arranged along the inner peripheral surface of the tire. The second sealant layer is composed of a substantially string-shaped sealant material continuously spirally arranged along the first sealant layer, and the sealant material constituting the first sealant layer. Since the sealant material constituting the second sealant layer is a pneumatic tire (sealant tire) arranged in the same circumferential direction and shifted in the tire width direction, the first sealant layer. And in the second sealant layer, the boundary surface portion between the adjacent sealant materials does not exist at the same position in the tire width direction, and even if the boundary surface between the adjacent sealant materials of one sealant layer is pierced. In the other sealant layer, it is possible to prevent the boundary surface between adjacent sealant materials from tearing in the circumferential direction, and the substantially string-shaped sealant is continuously arranged in a spiral shape along the inner peripheral surface of the tire. Even if the sealant layer is made of a material, the sealant layer has excellent tear resistance.

The sealant layer may be composed of at least two layers, a first sealant layer and a second sealant layer, and other layers may be further arranged as long as the effects of the present invention are not impaired.

In general, in a sealant tire having a sealant layer on the inner surface for preventing a puncture, what is the sealing performance?
1) Sealing performance when foreign matter such as nails sticks while driving.
2) When traveling at high speed after the holes formed by the foreign matter have expanded due to the destruction of the rubber around the part where the foreign matter has been stabbed due to the squeezing or heating of the foreign matter when traveling with the foreign matter stuck. Sealing performance when foreign matter comes out of the tire due to centrifugal force.
3) After driving with a foreign object stuck, the hole formed by the foreign substance expands, air gradually leaks from the tire, the internal pressure decreases, the internal pressure alarm device is activated, and the driver notices a flat tire. , Sealing performance when the driver pulls out foreign matter.
4) Sealing performance when the atmosphere of 3) is extremely low temperature.
It is roughly divided into four types.

Conventional sealant tires usually satisfy the sealing performance (initial sealing performance) of 1), but the sealing performance of 2) and 3) (sealing performance after running) is not sufficient. Further, the sealing performance of 2) and 3) can be ensured by using a relatively high-viscosity sealant material, but the high-viscosity sealant material becomes too viscous at low temperatures, and the sealing of 4) It was difficult to achieve both performance (sealing performance at low temperature).

On the other hand, the sealant layer arranged inside the inner liner in the tire radial direction has a laminated structure of a low-viscosity first sealant layer and a high-viscosity second sealant layer, and the first sealant layer is provided on the inner liner side. By arranging the second sealant layer on the tire cavity side (inside the tire radial direction of the first sealant layer), the second sealant layer has a high viscosity for large holes, and the first sealant layer has a low viscosity at low temperatures. Can be sealed with. As a result, it is possible to achieve both the sealing performance after running and the sealing performance at a low temperature, which was difficult with the conventional sealant tire, and further, a good initial sealing performance can be obtained.
In addition, since it is possible to seal with a high-viscosity second sealant layer in the hot summer and a low-viscosity first sealant layer in the cold winter, both the sealing performance in the summer and the sealing performance in the winter are compatible. You can also let it.

As described above, in the present invention, the viscosity of the first sealant layer is made lower than the viscosity of the second sealant layer, so that the tires are continuously arranged in a spiral shape along the inner peripheral surface of the tire. Even if the sealant layer is made of a roughly string-shaped sealant material, the sealant layer has excellent tear resistance, and the sealing performance after running and the sealing performance at low temperature, which were difficult with conventional sealant tires, are improved. Both are possible, and good initial sealing performance can be obtained. In addition, since it is possible to seal with a high-viscosity second sealant layer in the hot summer and a low-viscosity first sealant layer in the cold winter, both the sealing performance in the summer and the sealing performance in the winter are compatible. You can also let it.

FIG. 11 is an explanatory view schematically showing an example of the first sealant layer and the second sealant layer, and FIG. 14 is a schematic diagram of the behavior of the first sealant layer and the second sealant layer when the tire is punctured by a nail. It is explanatory drawing which shows. As shown in FIGS. 11 and 14, the sealant layer 22 has a structure in which the first sealant layer 22a and the second sealant layer 22b are laminated in this order from the inner liner 19 side of the tire 10. Then, as shown in FIG. 14A, when the nail A is pulled out after the nail A is pierced into the tire 10, the hole formed by the nail A is sealed by the sealant layer 22. As shown in FIG. 14 (b), the second sealant layer 22b having a high viscosity mainly seals at a high temperature or when the hole is large, and when the temperature is low or the hole is small, FIG. 14 (c) is used. As shown by, the first sealant layer 22a having a low viscosity is mainly sealed. In this way, while ensuring good initial sealing performance, it is possible to achieve both sealing performance after running and sealing performance at low temperatures, and both sealing performance in summer and sealing performance in winter. it can.

Further, by continuously spirally applying a string-shaped sealant material to the inner peripheral surface of the tire and the first sealant layer to form a sealant layer, the sealant material is a uniform sealant layer (inside the tire). A sealant layer composed of a substantially string-shaped sealant material continuously spirally arranged along the peripheral surface) can be formed on the inner peripheral surface of the tire, and a sealant tire having excellent sealing properties can be stably produced. Can be manufactured with good productivity. The sealant tire obtained by the manufacturing method is excellent in sealing property because the sealant material has a uniform sealant layer in the tire circumferential direction and the tire width direction (particularly, the tire circumferential direction). In addition, the balance of the tire is less likely to be lost due to the sealant material, and deterioration of tire uniformity can be reduced.

Further, in particular, by using a sealant material having a composition described later as the sealant material, the effect can be more preferably obtained. Further, in the sealant material having a composition described later, the holes formed at the time of puncture are automatically closed by the sealant material even in a low temperature environment.

As the sealant material having the composition described later, specifically, by using an organic peroxide as a cross-linking agent or by using a rubber component containing a butyl rubber mixed with a liquid polymer such as liquid polybutene, the sealant material can be used. The adhesiveness, sealing property, fluidity, and processability of the rubber are improved in a well-balanced manner, and the effect is more preferably obtained. This is because the liquid polymer component is introduced into the organic peroxide cross-linking system using butyl rubber as the rubber component to impart adhesiveness, and the liquid polymer having a different viscosity gives the liquid polymer a different viscosity during high-speed running (at high temperature). It is presumed that the performance of the sealant material is improved in a well-balanced manner by suppressing the flow of the sealant material. Further, by blending 1 to 30 parts by mass of the inorganic filler with respect to 100 parts by mass of the rubber component, the adhesiveness, sealing property, fluidity and processability of the sealant material are improved in a more balanced manner, and the effect is more preferable. can get.

Hereinafter, a preferred example of the method for producing a sealant tire of the present invention will be described.

For a sealant tire, for example, each component constituting the sealant material is mixed to prepare a sealant material, and then the obtained sealant material is attached to the inner peripheral surface of the tire by coating or the like to form a sealant layer. Can be manufactured. The sealant tire has a sealant layer inside the inner liner in the radial direction of the tire.

It is necessary to control the hardness (viscosity) of the sealant material according to the rubber component and the amount of cross-linking to control the viscosity according to the operating temperature. Therefore, as a control of the rubber component, the type and amount of liquid rubber, plasticizer, and carbon black are adjusted. On the other hand, in order to control the amount of cross-linking, the type and amount of the cross-linking agent and the cross-linking aid are adjusted. In this way, the viscosities of the first sealant layer and the second sealant layer can be easily adjusted.

The sealant material is not particularly limited as long as it has adhesiveness, and a normal rubber composition used for puncture sealing of tires can be used. Butyl-based rubber is used as the rubber component constituting the main component of the rubber composition. Examples of the butyl rubber include butyl rubber (IIR), halogenated butyl rubber (X-IIR) such as brominated butyl rubber (Br-IIR) and chlorinated butyl rubber (Cl-IIR). Among them, either one or both of butyl rubber and halogenated butyl rubber can be preferably used from the viewpoint of fluidity and the like. Further, it is preferable to use pelletized butyl rubber. As a result, the butyl rubber can be accurately and suitably supplied to the continuous kneader, and the sealant material can be produced with high productivity.

As a butyl rubber, from the viewpoint of suppressing a decrease in the fluidity of the sealant material, a butyl rubber A having a Mooney viscosity ML1 + 8 at 125 ° C. of 20 or more and less than 40 and / or a butyl rubber having a Mooney viscosity ML1 + 8 at 125 ° C. of 40 or more and 80 or less. The use of rubber B is preferable, and at least butyl rubber A is particularly preferable. When butyl rubbers A and B are used in combination, the blending ratio may be appropriately set.

The Mooney viscosity ML1 + 8 of the butyl rubber A at 125 ° C. is more preferably 25 or more, further preferably 28 or more, still more preferably 38 or less, still more preferably 35 or less. If it is less than 20, the fluidity may decrease, and if it is 40 or more, the effect may not be obtained when used in combination.

The Mooney viscosity ML1 + 8 of the butyl rubber B at 125 ° C. is more preferably 45 or more, further preferably 48 or more, still more preferably 70 or less, still more preferably 60 or less. If it is less than 40, the effect may not be obtained when used in combination. If it exceeds 80, the sealing property may be deteriorated.

The Mooney viscosity ML1 + 8 at 125 ° C. conforms to JIS K-6300-1: 2001, and the rotor having an L-shape has a residual heat time of 1 minute and a rotor rotation time of 8 minutes at a test temperature of 125 ° C. It is what is measured.

As rubber components, natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene butadiene rubber (SBR), styrene isoprene butadiene rubber (SIBR), ethylenepropylene diene rubber (EPDM), chloroprene rubber (CR) , Acrylonitrile-butadiene rubber (NBR), diene rubber such as butyl rubber (IIR), and other components may be used in combination, but from the viewpoint of fluidity, etc., the content of butyl rubber in 100% by mass of the rubber component Is preferably 90% by mass or more, more preferably 95% by mass or more, and particularly preferably 100% by mass.

Liquid polymers in the sealant material include liquid polybutene, liquid polyisobutene, liquid polyisoprene, liquid polybutadiene, liquid poly α-olefin, liquid isobutylene, liquid ethylene α-olefin copolymer, liquid ethylene propylene copolymer, and liquid ethylene butylene. Examples include polymers. Of these, liquid polybutene is preferable from the viewpoint of imparting adhesiveness and the like. Examples of the liquid polybutene include a copolymer having a molecular structure of a long-chain hydrocarbon obtained by reacting isobutene as a main component and normal butene, and a hydrogenated liquid polybutene can also be used.

As a liquid polymer such as liquid polybutene, from the viewpoint of preventing the flow of the sealant material during high-speed running, the kinematic viscosity of 100 ° C. is 550 to 625 mm, and the kinematic viscosity of ² / s is liquid polymer A and / or the kinematic viscosity of 100 ° C. is 3540 to 4010 mm. ^{The use of 2} / s liquid polymer B is preferable, and the combined use of the liquid polymers A and B is more preferable.

The kinematic viscosity of the liquid polymer A such as liquid polybutene at 100 ° C. is preferably 550 mm ² / s or more, and more preferably 570 mm ² / s or more. If it is less than 550 mm ² / s, the sealant material may flow. The kinematic viscosity at 100 ° C. is preferably 625 mm ² / s or less, more preferably 610 mm ² / s or less. If it exceeds 625 mm ² / s, the viscosity of the sealant material becomes high, and the extrudability may deteriorate.

The kinematic viscosity of the liquid polymer B such as liquid polybutene at 100 ° C. is preferably 3600 mm ² / s or more, and more preferably 3650 mm ² / s or more. If it is less than 3540 mm ² / s, the viscosity of the sealant material becomes too low, and it becomes easy to flow during use of the tire, which may deteriorate the sealing property and uniformity.
The kinematic viscosity at 100 ° C. is preferably 3900 mm ² / s or less, more preferably 3800 mm ² / s or less. If it exceeds 4010 mm ² / s, the sealing property may deteriorate.

Kinematic viscosity at 40 ° C. of liquid polymer A, such as liquid polybutene is preferably 20000 mm ² / s or more, more preferably 23000mm ² / s or more. If it is less than 20000 mm ² / s, the sealant material is soft and may flow. The kinematic viscosity at 40 ° C. is preferably 30,000 mm ² / s or less, more preferably 28,000 mm ² / s or less. If it exceeds 30,000 mm ² / s, the viscosity of the sealant material becomes too high, and the sealing property may deteriorate.

The kinematic viscosity of the liquid polymer B such as liquid polybutene at 40 ° C. is preferably 120,000 mm ² / s or more, and more preferably 150,000 mm ² / s or more. If it is less than 120,000 mm ² / s, the viscosity of the sealant material becomes too low, and it becomes easy to flow during use of the tire, which may deteriorate the sealing property and uniformity.
The kinematic viscosity at 40 ° C. is preferably 200,000 mm ² / s or less, more preferably 170,000 mm ² / s or less. If it exceeds 200,000 mm ² / s, the viscosity of the sealant material becomes too high, and the sealing property may deteriorate.

The kinematic viscosity is a value measured under the conditions of 100 ° C. and 40 ° C. in accordance with JIS K2283-2000.

In the case of the sealant material used for the first sealant layer, the content of the liquid polymer (total amount of the liquid polymers A, B, etc.) is preferably 200 parts by mass or more, preferably 230 parts by mass or more, based on 100 parts by mass of the rubber component. Is more preferable. The upper limit is not particularly limited, and may be about 300 parts by mass or less. Further, in the case of the sealant material used for the second sealant layer, 250 parts by mass or less is preferable, and 220 parts by mass or less is more preferable with respect to 100 parts by mass of the rubber component. The lower limit is not particularly limited, and may be about 150 parts by mass or more. If it is within the above range, the effect can be obtained more preferably.

When the liquid polymers A and B are used in combination, the blending ratio (content of the liquid polymer A / content of the liquid polymer B) is preferably 10/90 to 90/10, more preferably 30/70 to 70 /. 30, more preferably 40/60 to 60/40. When it is within the above range, good adhesiveness is imparted.

The organic peroxide (crosslinking agent) is not particularly limited, and conventionally known compounds can be used. In the organic peroxide cross-linking system, the adhesiveness, sealing property, fluidity, and processability are improved by using a butyl rubber or a liquid polymer.

Examples of the organic peroxide include acyl peroxides such as benzoyl peroxide, dibenzoyl peroxide, and p-chlorobenzoyl peroxide, 1-butyl peroxyacetate, t-butylperoxybenzoate, and t-butylperoxy. Peroxyesters such as phthalates, ketone peroxides such as methyl ethyl ketone peroxide, alkyl peroxides such as di-t-butylperoxybenzoate, 1,3-bis (1-butylperoxyisopropyl) benzene, t- Examples thereof include hydroperoxides such as butyl hydroperoxide, dicumyl peroxide, and t-butyl cumyl peroxide. Among them, acyl peroxides are preferable, and dibenzoyl peroxide is particularly preferable, from the viewpoint of adhesiveness and fluidity. Further, it is preferable to use an organic peroxide (crosslinking agent) in a powder state. As a result, the organic peroxide (crosslinking agent) can be accurately and appropriately supplied to the continuous kneader, and the sealant material can be produced with high productivity.

In the case of the sealant material used for the first sealant layer, the content of the organic peroxide (crosslinking agent) is preferably 15 parts by mass or less, more preferably 12 parts by mass or less, based on 100 parts by mass of the rubber component. The lower limit is not particularly limited, and may be about 5 parts by mass or more. Further, in the case of the sealant material used for the second sealant layer, 15 parts by mass or more is preferable, and 18 parts by mass or more is more preferable with respect to 100 parts by mass of the rubber component. The upper limit is not particularly limited, and may be about 25 parts by mass or less. If it is within the above range, the effect can be obtained more preferably.

As the cross-linking aid (vulverization accelerator), sulfenamide-based, thiazole-based, thiuram-based, thiourea-based, guanidine-based, dithiocarbamine-based, aldehyde-amine-based, aldehyde-ammonia-based, imidazoline-based, xanthogenic acid-based, And at least one selected from the group consisting of a quinonedioxime compound (kinoid compound) can be used, and for example, a quinonedioxime compound (kinoid compound) can be preferably used. By using a butyl rubber or a liquid polymer in a cross-linking system in which a cross-linking aid is further added to an organic peroxide, adhesiveness, sealing property, fluidity, and processability are improved.

Examples of the quinone dioxime compound include p-benzoquinone dioxime, p-quinone dioxime, p-quinone dioxym diacetate, p-quinone dioxymudicaploate, p-quinone dioxym dilaurate, and p-quinone dioxym distea. Rate, p-quinone dioxym dicrotonate, p-quinone dioxym dinaphthenate, p-quinone dioxym succinate, p-quinone dioxym adipate, p-quinone dioxym difuroate, p- Quinone dioxym dibenzoate, p-quinone dioxymudi (o-chlorobenzoate), p-quinone dioxymudi (p-chlorobenzoate), p-quinone dioxymudi (p-bitrobenzoate), p-quinone dioxime Di (m-bitrobenzoate), p-quinone dioxymudi (3,5-dinitrobenzoate), p-quinone dioxymudi (p-methoxybenzoate), p-quinone dioxymudi (n-amyloxybenzoate), Examples thereof include p-quinone dioxymudi (m-bromobenzoate). Of these, p-benzoquinone dioxime is preferable from the viewpoint of adhesiveness, sealing property, and fluidity. Further, it is preferable to use a cross-linking aid (vulcanization accelerator) in a powder state. As a result, the cross-linking aid (vulcanization accelerator) can be accurately and appropriately supplied to the continuous kneader, and the sealant material can be produced with high productivity.

In the case of the sealant material used for the first sealant layer, the content of the cross-linking aid such as the quinone dioxime compound is preferably 15 parts by mass or less, more preferably 12 parts by mass or less, based on 100 parts by mass of the rubber component. The lower limit is not particularly limited, and may be about 5 parts by mass or more. Further, in the case of the sealant material used for the second sealant layer, 15 parts by mass or more is preferable, and 18 parts by mass or more is more preferable with respect to 100 parts by mass of the rubber component. The upper limit is not particularly limited, and may be about 25 parts by mass or less. If it is within the above range, the effect can be obtained more preferably.

Sealant materials include carbon black, silica, calcium carbonate, calcium silicate, magnesium oxide, aluminum oxide, barium sulfate, talc, mica and other inorganic fillers, aromatic process oils, naphthenic process oils, and paraffinic process oils. A plasticizer such as the above may be added.

In the case of the sealant material used for the first sealant layer, the content of the inorganic filler is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, based on 100 parts by mass of the rubber component. The lower limit is not particularly limited, and may be about 10 parts by mass or more. Further, in the case of the sealant material used for the second sealant layer, 40 parts by mass or more is preferable, and 45 parts by mass or more is more preferable with respect to 100 parts by mass of the rubber component. The upper limit is not particularly limited, and may be about 65 parts by mass or less. If it is within the above range, the effect can be obtained more preferably.

Carbon black is preferable as the inorganic filler from the viewpoint of preventing deterioration due to ultraviolet rays. In the case of the sealant material used for the first sealant layer, the carbon black content is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, based on 100 parts by mass of the rubber component. The lower limit is not particularly limited, and may be about 10 parts by mass or more. Further, in the case of the sealant material used for the second sealant layer, 40 parts by mass or more is preferable, and 45 parts by mass or more is more preferable with respect to 100 parts by mass of the rubber component. The upper limit is not particularly limited, and may be about 65 parts by mass or less. If it is within the above range, the effect can be obtained more preferably.

The content of the plasticizer is preferably 1 part by mass or more, and more preferably 5 parts by mass or more with respect to 100 parts by mass of the rubber component. If it is less than 1 part by mass, the adhesiveness to the tire is lowered, and there is a possibility that sufficient sealing property cannot be obtained. The content is preferably 40 parts by mass or less, more preferably 20 parts by mass or less. If it exceeds 40 parts by mass, slippage may occur in the kneader and it may be difficult to knead the sealant material.

The sealant material is preferably prepared by mixing pelletized butyl rubber, powder cross-linking agent, and powder cross-linking aid, and pelletized butyl rubber and liquid polybutene. , Plasticant, powder carbon black, powder cross-linking agent, and powder cross-linking aid are more preferably prepared. As a result, each raw material can be suitably supplied to the continuous kneader, and the sealant material can be produced with high productivity.

The sealant material is preferably a mixture of a rubber component containing butyl rubber and a predetermined amount of a liquid polymer, an organic peroxide (crosslinking agent), and a crosslinking aid.

Adhesiveness, sealing property, and fluidity can be achieved by using a sealant material in which a liquid polymer such as liquid polybutene is mixed with butyl rubber, and in particular, by using two or more materials having different viscosities as the butyl rubber and the liquid polymer. , Workability is improved in a well-balanced manner. This is because a liquid polymer component is introduced into an organic peroxide cross-linking system using butyl rubber as a rubber component to impart adhesiveness, and a liquid polymer or solid butyl rubber having a different viscosity is used as a sealant material during high-speed running. By suppressing the flow, the adhesiveness, sealing property, fluidity, and processability are improved in a well-balanced manner.

The viscosities of the first sealant layer and the second sealant layer (viscosities of the sealant materials used for the first sealant layer and the second sealant layer) can be appropriately adjusted.
As described above, it is preferable that the viscosities of the first sealant layer and the second sealant layer are different because the sealing performance at low temperature to high temperature can be ensured. Since the temperature range that can be sealed differs depending on the viscosity of the sealant material, the viscosity of the first sealant layer and the second sealant layer differs, so that sealing is possible compared to the case of only one layer or the case of applying the same composition repeatedly. The temperature range is widened.
Further, the viscosity of the first sealant layer is increased because it is possible to achieve both the sealing performance after running and the sealing performance at a low temperature, which was difficult with the conventional sealant tire, and further, a good initial sealing performance can be obtained. It is preferably lower than the viscosity of the second sealant layer.

The viscosity of the first sealant layer at 0 ° C. is preferably less than 35 kPa · s, more preferably 25 kPa · s or less, and preferably 5 kPa · s or more, more preferably 10 kPa · s or more. The viscosity of the first sealant layer at 95 ° C. is preferably less than 6 kPa · s, more preferably 4 kPa · s or less, and preferably 1 kPa · s or more, more preferably 2 kPa · s or more. If it is within the above range, the effect can be obtained more preferably.

The viscosity of the second sealant layer at 0 ° C. is preferably 35 kPa · s or more, more preferably 40 kPa · s or more, and preferably 60 kPa · s or less, more preferably 45 kPa · s or less. The viscosity of the second sealant layer at 95 ° C. is preferably 6 kPa · s or more, preferably 15 kPa · s or less, and more preferably 9 kPa · s or less. If it is within the above range, the effect can be obtained more preferably.

The difference between the 0 ° C. viscosity of the first sealant layer and the 0 ° C. viscosity of the second sealant layer (the value obtained by subtracting the 0 ° C. viscosity of the first sealant layer from the 0 ° C. viscosity of the second sealant layer) is preferably 1 kPa · s. As described above, it is more preferably 10 kPa · s or more, further preferably 20 kPa · s or more, and preferably 55 kPa · s or less, more preferably 40 kPa · s or less, still more preferably 35 kPa · s or less.
The difference between the 95 ° C. viscosity of the first sealant layer and the 95 ° C. viscosity of the second sealant layer (the value obtained by subtracting the 95 ° C. viscosity of the first sealant layer from the 95 ° C. viscosity of the second sealant layer) is preferably 0.1 kPa. · S or more, more preferably 2 kPa · s or more, preferably 25 kPa · s or less, more preferably 15 kPa · s or less, still more preferably 12 kPa · s or less.
If it is within the above range, the effect can be obtained more preferably.

In the present specification, the viscosity of the sealant layer means the viscosity of the sealant material constituting the sealant layer, and the measurement is performed under the following conditions, and the measured strain is on the horizontal axis and the shear viscosity is on the vertical axis for each measurement temperature. The maximum value of the shear viscosity when the graph was created is the viscosity at each temperature (0 ° C., 95 ° C.).
FIG. 10 shows an outline of an example in which the steady flow shear viscosity of the sealant material is measured and a graph is created in which the measured strain is on the horizontal axis and the shear viscosity is on the vertical axis.
<Measurement conditions>
Measuring machine: Rheometer MCR52 (two-disk type rotational viscometer manufactured by Anton Pearl Co., Ltd.)
Measurement mode: Steady flow shear viscosity Measurement temperature: 0 ° C or 95 ° C
Preheating time: 1 minute (time after sandwiching between plates heated to the set temperature)
Gap: 1 mm (distance between plates, but no sealant material sticks out)
Measurement time: 15 (seconds)
Measurement distortion: 0 to 10,000 (%)
Shear velocity: 6 (1 / s)
Rotor shape: Circular plate (parallel flat plate type, disk diameter: 12 mm)

By mixing the above-mentioned materials to prepare a sealant material and applying the produced sealant material to the inner peripheral surface of the tire (preferably the inner part in the tire radial direction of the inner liner), the inner liner is placed inside the tire radial direction. A sealant tire having a sealant layer can be produced, but mixing of each material constituting the sealant material can be carried out using, for example, a known continuous kneader. Of these, it is preferable to mix using a multi-screw kneading extruder that rotates in the same direction or in a different direction, particularly a twin-screw kneading extruder.

The continuous kneader (particularly, the twin-screw kneading extruder) preferably has a plurality of supply ports for supplying raw materials, more preferably has at least three supply ports, and at least three on the upstream side, the middle flow side, and the downstream side. It is more preferred to have one supply port. By sequentially supplying the various raw materials to a continuous kneader (particularly, a twin-screw kneading extruder), the various raw materials are mixed, and a sealant material is sequentially and continuously prepared.

It is preferable that the raw materials are supplied to the continuous kneader (particularly, the twin-screw kneading extruder) in order from the material having the highest viscosity. As a result, each material can be sufficiently mixed to prepare a sealant material having a constant quality. In addition, it is desirable to add the powder material upstream as much as possible because the kneadability is improved when the powder material is added.

It is preferable that the organic peroxide is supplied to the continuous kneader (particularly, the twin-screw kneading extruder) from the supply port on the downstream side. As a result, the time from the supply of the organic peroxide to the application of the sealant material to the tire can be shortened, so that the sealant material can be applied to the tire before the curing progresses, and the sealant tire can be manufactured more stably.

If a large amount of liquid polymer is put into a continuous kneader (particularly a twin-screw kneading extruder) at one time, kneading will not be successful. It is preferable to do it by mouth. This makes it possible to more preferably knead the sealant material.

When a continuous kneader (particularly a twin-screw kneading extruder) is used, the sealant material is a continuous kneader (particularly a twin-screw kneading extruder) having at least three supply ports, and the continuous kneader (particularly two) is used. A rubber component such as butyl rubber, an inorganic filler, and a cross-linking aid are supplied from the supply port on the upstream side of the shaft kneading extruder), liquid polymer B is supplied from the supply port on the middle stream side, and the liquid polymer B is supplied on the downstream side. It is preferably prepared by supplying the liquid polymer A, the organic peroxide, and the plasticizing agent from the supply port and kneading and extruding. Although all or part of each material such as a liquid polymer may be supplied from each supply port, it is preferable to supply 95% by mass or more of the total amount of each material.

It is preferable that all the raw materials charged into the continuous kneader are controlled by a supply device capable of controlling a fixed amount of supply and charged into the continuous kneader. This makes it possible to prepare the sealant material in a continuous and automated state.

The feeding device is not particularly limited as long as the fixed quantity feeding can be controlled, and a known feeding device can be used. For example, a screw type feeder, a plunger pump, a gear pump, a mono pump and the like can be used.

Solid raw materials (particularly pellets and powders) such as pelletized butyl rubber, powder carbon black, powder cross-linking agent, and powder cross-linking aid are quantitatively supplied using a screw feeder. Is preferable. As a result, it becomes possible to supply a solid raw material in an accurate and quantitative manner, and it is possible to manufacture a higher quality sealant material and, by extension, a higher quality sealant tire.

Further, it is preferable that each solid raw material is supplied by a separate supply device. As a result, it is not necessary to blend each raw material in advance, so that the material can be easily supplied at the time of mass production.

The plasticizer is preferably supplied in a fixed quantity using a plunger pump. As a result, the plasticizer can be accurately and quantitatively supplied, and a higher quality sealant material and, by extension, a higher quality sealant tire can be manufactured.

The liquid polymer is preferably quantitatively supplied using a gear pump. As a result, the liquid polymer can be accurately and quantitatively supplied, and a higher quality sealant material and, by extension, a higher quality sealant tire can be manufactured.

The liquid polymer to be supplied is preferably controlled at a constant temperature. By controlling the temperature at a constant temperature, it becomes possible to supply a fixed amount of the liquid polymer with higher accuracy. The temperature of the supplied liquid polymer is preferably 20 to 90 ° C, more preferably 40 to 70 ° C.

Mixing of a continuous kneader (particularly, a twin-screw kneading extruder) is preferably carried out at a barrel temperature of 30 (preferably 50) to 150 ° C. from the viewpoint of ease of mixing, extrusion property, dispersibility, and cross-linking reaction. ..

From the viewpoint of sufficient mixing, the mixing time of the material supplied on the upstream side is preferably 1 to 3 minutes, and the mixing time of the material supplied on the middle stream side is preferably 1 to 3 minutes. On the other hand, from the viewpoint of preventing cross-linking, the mixing time of the material supplied on the downstream side is preferably 0.5 to 2 minutes. Each mixing time refers to the residence time from being supplied to the continuous kneader (particularly, the twin-screw kneading extruder) to being discharged. For example, the mixing time of the material supplied on the downstream side is the downstream side. It is the residence time from the time of supply to the supply port to the time of discharge.

The temperature of the sealant material discharged from the discharge port can be adjusted by setting the screw rotation speed of the continuous kneader (especially the twin-screw kneading extruder) and the temperature controller, and by extension, the curing acceleration speed of the sealant material can be controlled. .. In a continuous kneader (particularly, a twin-screw kneading extruder), the kneadability and the material temperature increase as the number of rotations of the screw increases. The rotation speed of the screw does not affect the discharge amount. The rotation speed of the screw is preferably 50 to 700 (preferably 550) rpm from the viewpoint of sufficient mixing and control of the curing acceleration rate.

The temperature of the sealant material discharged from the discharge port of the continuous kneader (particularly, the twin-screw kneading extruder) is preferably 70 to 150 ° C. from the viewpoint of sufficient mixing property and control of the curing acceleration rate. More preferably, it is 90 to 130 ° C. When the temperature of the sealant material is within the above range, the cross-linking reaction starts from the time of application, the tire has good adhesiveness to the inner peripheral surface of the tire, and the cross-linking reaction proceeds more favorably, so that the sealant tire having high sealing property Can be manufactured. Moreover, the cross-linking step described later is not required.

The amount of the sealant material discharged from the discharge port of the continuous kneader (particularly, the twin-screw kneading extruder) is determined based on the amount of the raw material supplied to the supply port. The amount of raw material supplied to the supply port is not particularly limited and can be appropriately set by those skilled in the art.
It is preferable that the amount (discharge amount) of the sealant material discharged from the discharge port is substantially constant because a sealant tire having excellent uniformity and sealing property can be preferably obtained.
Here, in the present specification, when the discharge amount is substantially constant, the fluctuation of the discharge amount is 93 to 107% (preferably 97 to 103%, more preferably 98 to 102%, still more preferably 99 to 101%). ) Means to fit.

It is preferable to connect a nozzle to the discharge port of the continuous kneader (particularly, the twin-screw kneading extruder). Since a continuous kneader (particularly a twin-screw kneading extruder) can discharge a material at a high pressure, a nozzle (preferably a small diameter nozzle having a large resistance) is attached to the discharge port to form a thin substantially string-shaped sealant material (preferably a small diameter nozzle with a large resistance). It can be made into a bead shape and attached to the tire. That is, by discharging the sealant material from the nozzle connected to the discharge port of the continuous kneader (particularly, the twin-screw kneading extruder) and sequentially applying it to the inner peripheral surface of the tire, the thickness of the sealant material is substantially reduced. It becomes constant, deterioration of tire uniformity can be prevented, and a sealant tire having an excellent weight balance can be manufactured.

Next, the mixed sealant material is discharged from a nozzle connected to the discharge port of an extruder such as a continuous kneader (particularly a twin-screw kneading extruder) to directly feed the mixed sealant material to the inner peripheral surface of the vulcanized tire. , Sealant tires are manufactured by applying to the inner peripheral surface. As a result, the sealant material that has been mixed by a twin-screw kneading extruder or the like and whose progress of the cross-linking reaction in the extruder is suppressed can be applied to the inner peripheral surface of the tire as it is. It has good adhesiveness to the peripheral surface, and the cross-linking reaction proceeds favorably. As a result, the sealant material applied to the inner peripheral surface of the tire forms a sealant layer while preferably maintaining a substantially string-like shape. Therefore, the sealant coating process becomes possible in a series of steps, and the productivity is further improved. Further, by applying the sealant material to the inner peripheral surface of the vulcanized and molded tire, the sealant tire can be manufactured with higher productivity. Further, it is preferable to sequentially apply the sealant material discharged from the nozzle connected to the discharge port of the continuous kneader (particularly, the twin-screw kneading extruder) directly to the inner peripheral surface of the tire. As a result, the sealant material in which the progress of the crosslinking reaction in the continuous kneader (particularly the twin-screw kneading extruder) is suppressed can be continuously applied to the inner peripheral surface of the tire as it is, so that the crosslinking reaction starts from the time of application. A sealant tire having good adhesiveness to the inner peripheral surface of the tire and having a suitable cross-linking reaction can be produced, which is more productive and has an excellent weight balance.

The sealant material may be applied to the inner peripheral surface of the tire at least on the inner peripheral surface of the tire corresponding to the tread portion, more preferably at least on the inner peripheral surface of the tire corresponding to the breaker. By omitting the application of the sealant material to the unnecessary portion, the sealant tire can be manufactured with higher productivity.
Here, the inner peripheral surface of the tire corresponding to the tread portion means the inner peripheral surface of the tire located inside the tire radial direction of the tread portion in contact with the road surface, and the inner peripheral surface of the tire corresponding to the breaker is defined as the inner peripheral surface of the tire. It means the inner peripheral surface of the tire located inside the breaker in the tire radial direction. The breaker is a member arranged inside the tread and outside in the radial direction of the carcass, and specifically, is a member shown in the breaker 16 or the like in FIG.

Normally, unvulcanized tires are vulcanized using a bladder. This bladder expands during vulcanization and comes into close contact with the inner peripheral surface (inner liner) of the tire. Therefore, a mold release agent is usually applied to the inner peripheral surface (inner liner) of the tire so that the bladder and the inner peripheral surface (inner liner) of the tire do not adhere to each other when the vulcanization is completed.

As the release agent, a water-soluble paint or a release rubber is usually used. However, if the release agent is present on the inner peripheral surface of the tire, the adhesiveness between the sealant material and the inner peripheral surface of the tire may decrease. Therefore, it is preferable to remove the mold release agent from the inner peripheral surface of the tire in advance. In particular, it is more preferable to remove the release agent in advance at least in the portion of the inner peripheral surface of the tire where the sealant material is to be applied. It is more preferable to remove the mold release agent in advance from all the portions of the inner peripheral surface of the tire to which the sealant material is applied. As a result, the adhesion of the sealant material to the inner peripheral surface of the tire is further improved, and a sealant tire having a higher sealing property can be manufactured.

The method for removing the release agent from the inner peripheral surface of the tire is not particularly limited, and examples thereof include known methods such as buffing, laser treatment, high-pressure water washing, and removal with a detergent (preferably a neutral detergent).

Here, an example of a manufacturing facility used in a method for manufacturing a sealant tire will be briefly described with reference to FIG. 7.
The manufacturing equipment includes a twin-screw kneading extruder 60, a material feeder 62 that supplies raw materials to the twin-screw kneading extruder 60, and a rotary drive device 50 that fixes and rotates the tire 10 and moves the tire in the width direction and the radial direction. Has. The twin-screw kneading extruder 60 has five supply ports 61. Specifically, it has three supply ports 61a on the upstream side, one supply port 61b on the middle stream side, and one supply port 61c on the downstream side. Further, a nozzle 30 is connected to the discharge port of the twin-screw kneading extruder 60.

Raw materials are sequentially supplied from the material feeder 62 to the twin-screw kneading extruder 60 via the supply port 61 of the twin-screw kneading extruder 60, and each raw material is kneaded by the twin-screw kneading extruder 60 to sequentially prepare a sealant material. Will be done. The prepared sealant material is continuously discharged from the nozzle 30 connected to the discharge port of the twin-screw kneading extruder 60. Traverse and / or move up and down (move in the width direction and / or radial direction of the tire) while rotating the tire with the tire drive device, and sequentially apply the sealant material discharged from the nozzle 30 directly to the inner peripheral surface of the tire. As a result, the sealant material can be continuously and spirally attached to the inner peripheral surface of the tire. That is, while rotating the tire and moving it in the width direction and / or the radial direction of the tire, the sealant material continuously discharged from the continuous kneader (particularly, the twin-screw kneading extruder) is sequentially applied to the inner peripheral surface of the tire. By applying it directly, the sealant material can be continuously and spirally attached to the inner peripheral surface of the tire.

By continuously spirally pasting the sealant material on the inner peripheral surface of the tire, deterioration of tire uniformity can be prevented, and a sealant tire having an excellent weight balance can be manufactured. Further, by continuously spirally pasting the sealant material on the inner peripheral surface of the tire, the sealant material can form a uniform sealant layer in the tire circumferential direction and the tire width direction (particularly, the tire circumferential direction), so that the sealant can be sealed. A sealant tire with excellent properties can be manufactured stably and with good productivity. The sealant material is preferably attached so as not to overlap in the width direction, and more preferably it is attached without a gap. As a result, deterioration of tire uniformity can be further prevented, and a more uniform sealant layer can be formed.
Further, for the reason that the effect can be obtained more preferably, it is preferable that the adjacent sealant materials are in contact with each other in the first sealant layer, and it is more preferable that the sealants are not overlapped in the width direction and are attached without gaps. preferable. For the same reason, it is preferable that the adjacent sealant materials are in contact with each other in the second sealant layer, and it is more preferable that the sealant materials are not overlapped in the width direction and are attached without gaps.

Further, the raw materials are sequentially supplied to a continuous kneader (particularly, a twin-screw kneading extruder), and the sealant material is sequentially prepared by the continuous kneader (particularly, a twin-screw kneading extruder), and the prepared sealant material is continuously kneaded. It is continuously discharged from a nozzle connected to the discharge port of the machine (particularly, a twin-screw kneading extruder), and the sealant material is sequentially applied directly to the inner peripheral surface of the tire. As a result, the sealant tire can be manufactured with high productivity.

The sealant layer is preferably formed by continuously and spirally applying a string-shaped sealant material to the inner peripheral surface of the tire. This makes it possible to form a sealant layer composed of a substantially string-shaped sealant material continuously spirally arranged along the inner peripheral surface of the tire on the inner peripheral surface of the tire.
When laminating the first sealant layer and the second sealant layer, first, the first sealant layer is arranged in a spiral shape, and then the second sealant layer is arranged in a spiral shape so as to overlap the first sealant layer. do it.

Here, the first sealant layer is composed of a substantially string-shaped sealant material that is continuously spirally arranged along the inner peripheral surface of the tire, and the second sealant layer is the first sealant layer. It is composed of a substantially string-shaped sealant material that is continuously spirally arranged along the tire, and the sealant material that constitutes the first sealant layer and the sealant material that constitutes the second sealant layer have the same circumference. First, the first sealant layer is spirally arranged so as to be arranged in the direction and shifted in the tire width direction, and then the second sealant layer is arranged so as to overlap the first sealant layer. It may be arranged in a spiral shape similar to that of the first sealant layer by shifting it from one sealant layer in the tire width direction. That is, it is preferable that the first sealant layer and the second sealant layer are formed by continuously and spirally applying a substantially string-shaped sealant material except that the sealant layer is displaced in the tire width direction.

In the present specification, the sealant material constituting the first sealant layer and the sealant material constituting the second sealant layer are arranged in the same circumferential direction in the first sealant layer and the second sealant layer. , It means that the direction in which the substantially string-shaped sealant material extends (the direction in which the sealant material is applied) is the same circumferential direction. When the sealant material constituting the first sealant layer and the sealant material constituting the second sealant layer are arranged in the same circumferential direction, when the sealant material is cut in a straight line orthogonal to the coating direction (length direction) of the sealant material. The cross section of the sealant layer is as shown in FIG. 12, for example.

Further, in the present specification, the sealant material forming the first sealant layer and the sealant material forming the second sealant layer are arranged so as to be offset in the tire width direction, as shown in FIG. In the cross section of the sealant layer when cut in a straight line orthogonal to the coating direction (length direction), the central portion of each sealant material constituting the first sealant layer in the tire width direction and each sealant material constituting the second sealant layer. It means that the central portion in the tire width direction of the above is present at a different position in the tire width direction.

It is preferable that the sealant material forming the first sealant layer and the sealant material forming the second sealant layer have substantially the same width W of the sealant material because the effect can be more preferably obtained. If the widths of the sealant material forming the first sealant layer and the sealant material forming the second sealant layer are different, even if the first sealant layer and the second sealant layer are arranged so as to be offset in the tire width direction. , In the boundary surface portion between some adjacent sealant materials, in the first sealant layer and the second sealant layer, the boundary surface portion between the adjacent sealant materials may exist at the same position in the tire width direction. However, such a possibility can be eliminated by making the width W of the sealant material substantially the same.
Here, in the present specification, the width W of the sealant material is substantially the same as the width of the sealant material forming the second sealant layer is 90 to 90 to the width of the sealant material forming the first sealant layer. It means that it is contained in 110% (preferably 95 to 105%, more preferably 98 to 102%, still more preferably 99 to 101%).

The sealant material forming the first sealant layer and the sealant material forming the second sealant layer have substantially the same width W of the sealant material, and are 2 mm to 5 mm, because the effect can be obtained more preferably. It is preferable that the _gap d gap between the sealant material forming the first sealant layer and the sealant material forming the second sealant layer in the tire width direction satisfies the following formula.
[W / 4] ≤d _gap ≤ [W / 2]
The width W of the sealant material is preferably 2.5 mm or more, preferably 4 mm or less, and more preferably 3.5 mm or less.
The d _gap is preferably [W / 3] or more, and more preferably d _gap = [W / 2].
Further, in the present specification, d _gap refers to the central portion of the sealant material constituting the first sealant layer in the tire width direction and the central portion of the sealant material constituting the second sealant material adjacent to the sealant material in the tire width direction. Means the length (deviation) in the tire width direction (see FIG. 12).

It is preferable that the thickness of the first sealant layer and the second sealant layer are different. As a result, for example, the second sealant layer (sealant material used for the second sealant layer) is made thicker than the first sealant layer (sealant material used for the first sealant layer), thereby improving the sealing performance after running. It can be further improved, and conversely, by making the first sealant layer (the sealant material used for the first sealant layer) thicker than the second sealant layer (the sealant material used for the second sealant layer), sealing at a low temperature can be achieved. The performance can be further improved, and the performance according to the usage environment can be imparted to the sealant layer.

The thickness of the first sealant layer (sealant material used for the first sealant layer) is preferably 1 mm or more, more preferably 1.3 mm or more, further preferably 2 mm or more, and preferably 5 mm or less, more preferably. Is 4 mm or less, more preferably 3 mm or less.
The thickness of the second sealant layer (sealant material used for the second sealant layer) is preferably 1 mm or more, more preferably 1.3 mm or more, still more preferably 2 mm or more, and preferably 5 mm or less, more preferably. Is 4 mm or less, more preferably 3 mm or less.
The total thickness of the first sealant layer and the second sealant layer is preferably 7 mm or less, more preferably 6 mm or less, and preferably 3 mm or more, more preferably 4 mm or more.
If it is within the above range, the effect can be obtained more preferably.

The number of times the sealant material is wrapped around the inner peripheral surface of the tire is preferable because it can prevent deterioration of the tire uniformity, has an excellent weight balance, and can more productively manufacture a sealant tire having good sealing properties. It is 20 to 70 times, more preferably 20 to 60 times, still more preferably 35 to 50 times. Here, the number of times of winding is 2 times means that the sealant material is applied so as to make two turns around the inner peripheral surface of the tire, and in FIG. 4, the number of times of winding the sealant material is 6 times.

By using a continuous kneader (particularly a twin-screw kneading extruder), the sealant material can be prepared (kneaded) and the sealant material can be discharged (applied) at the same time, resulting in high viscosity and high adhesiveness. The sealant material, which is difficult to handle, can be applied directly to the inner peripheral surface of the tire without handling, and the sealant tire can be manufactured with high productivity. In addition, when a sealant material is prepared by kneading the sealant material with a batch kneading device, the time from the preparation of the sealant material to the attachment to the tire is not constant, but the raw materials containing the organic peroxide are continuously kneaded. By sequentially applying the sealant material, which is sequentially prepared by mixing with a machine (particularly, a twin-screw kneading extruder), to the inner peripheral surface of the tire, the time from the preparation of the sealant material to the attachment to the tire becomes constant. Therefore, when the sealant material is applied using the nozzle, the amount of the sealant material discharged from the nozzle is stable, and further, the sealant material has a constant adhesiveness while suppressing a decrease in the adhesiveness to the tire. Even if a sealant material with high viscosity, high adhesiveness and difficult handling is used, it can be applied to the inner peripheral surface of the tire with high accuracy, and a sealant tire of constant quality can be stably produced.

Next, a method of applying the sealant material to the inner peripheral surface of the tire will be described below.

<First Embodiment>
In the first embodiment, in the sealant tire, the adhesive sealant material is applied to the inner peripheral surface of the tire by the nozzle while rotating the tire and moving at least one of the tire and the nozzle in the width direction of the tire. When applying, based on the step (1) of measuring the distance between the inner peripheral surface of the tire and the tip of the nozzle with a non-contact displacement sensor and the measurement result, at least one of the tire and the nozzle is in the radial direction of the tire. The step (2) of adjusting the distance between the inner peripheral surface of the tire and the tip of the nozzle to a predetermined distance by moving the tire to, and applying the sealant material to the inner peripheral surface of the tire for which the distance has been adjusted. It can be manufactured by performing the step (3) and the like.

By measuring the distance between the inner peripheral surface of the tire and the tip of the nozzle using a non-contact displacement sensor and feeding back the measurement result, the distance between the inner peripheral surface of the tire and the tip of the nozzle is kept constant. Can be kept. Then, since the sealant material is applied to the inner peripheral surface of the tire while keeping the above interval at a constant distance, the thickness of the sealant material is made uniform without being affected by the variation in the tire shape and the unevenness of the joint portion and the like. Can be. Further, since it is not necessary to input the coordinate values for each tire size as in the conventional case, the sealant material can be applied efficiently.

FIG. 1 is an explanatory diagram schematically showing an example of a coating device used in a method for manufacturing a sealant tire. Further, FIG. 2 is an enlarged view of the vicinity of the tip of the nozzle constituting the coating device shown in FIG.

FIG. 1 shows a cross section of a part of the tire 10 cut in the meridional direction (a cross section cut in a plane including the width direction and the radial direction of the tire), and FIG. 2 shows a part of the tire 10 cut around the tire circumference. A cross section cut by a plane including a directional direction and a radial direction is shown. In FIGS. 1 and 2, the X direction is the tire width direction (axial direction), the Y direction is the tire circumferential direction, and the Z direction is the tire radial direction.

The tire 10 is set in a rotation drive device (not shown) that fixes and rotates the tire and moves the tire in the width direction and the radial direction. This rotation drive device independently enables rotation of the tire around an axis, movement in the width direction of the tire, and movement in the radial direction of the tire.

Further, the rotary drive device includes a control mechanism (not shown) capable of controlling the amount of movement of the tire in the radial direction. The control mechanism may be capable of controlling the amount of movement of the tire in the width direction and / or the rotational speed of the tire.

The nozzle 30 is attached to the tip of an extruder (not shown) and can be inserted inside the tire 10. Then, the adhesive sealant material 20 extruded from the extruder is discharged from the tip 31 of the nozzle 30.

The non-contact displacement sensor 40 is attached to the nozzle 30 and measures the distance d between the inner peripheral surface 11 of the tire 10 and the tip 31 of the nozzle 30.
As described above, the distance d measured by the non-contact displacement sensor is the distance in the radial direction of the tire between the inner peripheral surface of the tire and the tip of the nozzle.

In the method for manufacturing a sealant tire of the present embodiment, first, the tire 10 formed in the vulcanization step is set in the rotary drive device, and the nozzle 30 is inserted inside the tire 10. Then, as shown in FIGS. 1 and 2, the sealant material 20 is discharged from the nozzle 30 while rotating the tire 10 and moving the tire 10 in the width direction to continuously reach the inner peripheral surface 11 of the tire 10. Apply to the tire. The movement of the tire 10 in the width direction is performed along the profile shape of the inner peripheral surface 11 of the tire 10 that has been input in advance.

As will be described later, the sealant material 20 preferably has a substantially string-like shape, and more specifically, when the sealant material is applied to the inner peripheral surface of the tire, the sealant material retains the substantially string-like shape. It is preferable, in this case, the substantially string-shaped sealant material 20 is continuously attached to the inner peripheral surface 11 of the tire 10 in a spiral shape.

In the present specification, the substantially string-like shape means a shape having a length longer than a width and having a certain width and thickness. FIG. 4 schematically shows an example of a state in which a substantially string-shaped sealant material is continuously and spirally attached to the inner peripheral surface of the tire. Further, FIG. 8 schematically shows an example of a cross section of the sealant material when the sealant material of FIG. 4 is cut along a straight line AA orthogonal to the coating direction (length direction) of the sealant material. As described above, the substantially string-shaped sealant material has a certain width (length indicated by W in FIG. 8) and a certain thickness (length indicated by D in FIG. 8). Here, the width of the sealant material means the width of the sealant material after application, and the thickness of the sealant material is the thickness of the sealant material after application, more specifically, the thickness of the sealant layer. Means.

Specifically, the substantially string-shaped sealant material has a thickness of the sealant material (thickness of the sealant material after application, thickness of the sealant layer, length indicated by D in FIG. 8), which will be described later. A sealant material that satisfies a preferable numerical range and a preferable numerical range of the width of the sealant material (width of the sealant material after coating, length indicated by W in FIG. 4, length indicated by W _{0 in FIG. 6).} More preferably, the sealant material satisfies the preferable numerical range of the ratio of the thickness of the sealant material to the width of the sealant material (thickness of the sealant material / width of the sealant material), which will be described later. It is also a sealant material that satisfies a preferable numerical range of the cross-sectional area of the sealant material, which will be described later.

In the method for manufacturing a sealant tire of the present embodiment, the sealant material is applied to the inner peripheral surface of the tire by the following steps (1) to (3).

<Process (1)>
As shown in FIG. 2, the non-contact displacement sensor 40 measures the distance d between the inner peripheral surface 11 of the tire 10 and the tip 31 of the nozzle 30 before the sealant material 20 is applied. The distance d is measured every time the sealant material 20 is applied to the inner peripheral surface 11 of each tire 10, and is performed from the start of application of the sealant material 20 to the end of application.

<Process (2)>
The measurement data of the distance d is transferred to the control mechanism of the rotation drive device. Based on the measurement data, the control mechanism adjusts the amount of movement of the tire in the radial direction so that the distance between the inner peripheral surface 11 of the tire 10 and the tip 31 of the nozzle 30 is a predetermined distance.

<Process (3)>
Since the sealant material 20 is continuously discharged from the tip 31 of the nozzle 30, it will be applied to the inner peripheral surface 11 of the tire 10 whose interval has been adjusted. By the above steps (1) to (3), the sealant material 20 having a uniform thickness can be applied to the inner peripheral surface 11 of the tire 10.

FIG. 3 is an explanatory diagram schematically showing the positional relationship of the nozzle with respect to the tire.
As shown in FIG. 3, while the nozzle 30 moves to the positions indicated by (a) to (d) with respect to the tire 10, the distance between the inner peripheral surface 11 of the tire 10 and the tip 31 of the nozzle 30 is a predetermined distance. The sealant material can be applied while keeping _{d 0.}

The reason that the effect can be obtained more suitably, adjusted distance _{d 0} of is preferably 0.3mm or more, more preferably 1.0mm or more. If it is less than 0.3 mm, the tip of the nozzle is too close to the inner peripheral surface of the tire, and it becomes difficult to apply a sealant material having a predetermined thickness. The adjusted interval d ₀ is preferably 3.0 mm or less, more preferably 2.0 mm or less. If it exceeds 3.0 mm, the sealant material may not be attached to the tire well, and the manufacturing efficiency may decrease.
Here, the adjusted interval d ₀ is the distance in the radial direction of the tire between the inner peripheral surface of the tire and the tip of the nozzle after being adjusted by the above step (2).

_{Further, the interval d 0} after adjustment is preferably 30% or less, more preferably 20% or less of the thickness of the sealant material after application, and the sealant material after application is more preferable, because the effect can be obtained more preferably. 5% or more is preferable, and 10% or more is more preferable.

The thickness of the sealant material (thickness of the sealant material after application, thickness of the sealant layer, length indicated by D in FIG. 8) is not particularly limited, but is preferable because the effect can be obtained more preferably. Is 1.0 mm or more, more preferably 1.5 mm or more, still more preferably 2.0 mm or more, particularly preferably 2.5 mm or more, and preferably 10.0 mm or less, more preferably 8.0 mm or less, further. It is preferably 5.0 mm or less. If it is less than 1.0 mm, it becomes difficult to reliably close the puncture hole when the tire punctures. Further, even if it exceeds 10.0 mm, the effect of closing the puncture hole does not change so much, and the weight of the tire increases, which is not preferable. The thickness of the sealant material can be adjusted by adjusting the rotation speed of the tire, the moving speed in the width direction of the tire, the distance between the tip of the nozzle and the inner peripheral surface of the tire, and the like.

The thickness of the sealant material (thickness of the sealant material after application, thickness of the sealant layer) is preferably substantially constant. As a result, deterioration of tire uniformity can be further prevented, and a sealant tire having a better weight balance can be manufactured.
Here, in the present specification, when the thickness is substantially constant, the variation in thickness is 90 to 110% (preferably 95 to 105%, more preferably 98 to 102%, still more preferably 99 to 101%). ) Means to fit.

It is preferable to use a substantially string-shaped sealant material because the nozzle is less clogged and has excellent operational stability, and because the effect can be obtained more preferably. It is more preferable to attach the tire to the inner peripheral surface in a spiral shape. However, a sealant material that does not have a substantially string shape may be used, and the sealant material may be applied by spraying on the inner peripheral surface of the tire.

When a substantially string-shaped sealant material is used, the width of the sealant material (width of the sealant material after application, length indicated by W in FIG. 4) is not particularly limited, but it is said that the effect can be obtained more preferably. For this reason, it is preferably 0.8 mm or more, more preferably 1.3 mm or more, still more preferably 1.5 mm or more. If it is less than 0.8 mm, the number of times the sealant material is wound around the inner peripheral surface of the tire increases, and the manufacturing efficiency may decrease. The width of the sealant material is preferably 18 mm or less, more preferably 13 mm or less, further preferably 9.0 mm or less, particularly preferably 7.0 mm or less, most preferably 6.0 mm or less, and even more preferably 5.0 mm. It is as follows. If it exceeds 18 mm, weight imbalance may easily occur.

The thickness of the sealant material (thickness of the sealant material after application, the thickness of the sealant layer, the length indicated by D in FIG. 8) and the width of the sealant material (width of the sealant material after application, in FIG. 4). The ratio (thickness of sealant material / width of sealant material) (length represented by W) is preferably 0.6 to 1.4, more preferably 0.7 to 1.3, and even more preferably 0. It is 8 to 1.2, particularly preferably 0.9 to 1.1. The closer the ratio is to 1.0, the more the shape of the sealant material becomes an ideal string-like shape, and a sealant tire having a high sealing property can be manufactured with higher productivity.

The cross-sectional area of the sealant material (cross-sectional area of the sealant material after coating, the area calculated by D × W in FIG. 8) is preferably 0.8 mm ² or more because the effect can be obtained more preferably. preferably 1.95 mm ² or more, more preferably 3.0 mm ² or more, particularly preferably 3.75 mm ² or more, preferably 180 mm ² or less, more preferably 104 mm ² or less, more preferably 45 mm ² or less, particularly preferably Is 35 mm ² or less, most preferably 25 mm ² or less.

The width of the area where the sealant material is attached (hereinafter, also referred to as the width of the application area and the width of the sealant layer, the length represented by 6 × W in FIG. 4, and W ₁ + 6 × W ₀ in FIG. The length represented) is not particularly limited, but 80% or more, 90% or more, more preferably 100% or more, and 120% or more of the tread contact width are preferable, and 100% or more is more preferable, because the effect can be obtained more preferably. % Or less is preferable, and 110% or less is more preferable.

The width of the sealant layer is preferably 85 to 115%, preferably 95 to 105% of the breaker width of the tire (the length of the breaker in the tire width direction) because the effect is more preferably obtained. More preferred.
In the present specification, when a plurality of breakers are provided on the tire, the length of the breaker in the tire width direction is the length in the tire width direction of the breaker having the longest length in the tire width direction among the plurality of breakers. Means length.

In the present specification, the tread ground contact width is defined as follows. First, the outermost contact position in the tire axial direction when a normal load is applied to a non-load normal tire that is rim-assembled on a regular rim and is filled with a regular internal pressure and is grounded on a flat surface at a camber angle of 0 degrees. Is defined as the "grounding end" Te. Then, the distance between the ground contact ends Te and Te in the tire axial direction is defined as the tread ground contact width TW. Unless otherwise specified, the dimensions and the like of each part of the tire are values measured in this normal state.

The above "regular rim" is a rim defined for each tire in the standard system including the standard on which the tire is based. In the case of JATTA, it is a "standard rim", and in the case of TRA, it is "Design Rim". , ETRTO is "Measuring Rim". Further, the above "regular internal pressure" is the air pressure defined for each tire in the standard system including the standard on which the tire is based. In the case of JATTA, the "maximum air pressure" is used, and in the case of TRA, the table " The maximum value described in "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES", and "INFLATION PRESSURE" for ETRTO, but 180 kPa when the tires are for passenger cars.

In addition, the above "regular load" is the load defined for each tire in the standard system including the standard on which the tire is based. The maximum value described in "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES", and "LOAD CAPACITY" for ETRTO, but when the tire is for a passenger car, the load is equivalent to 88% of the above load.

The rotation speed of the tire when the sealant material is applied is not particularly limited, but is preferably 5 m / min or more, more preferably 10 m / min or more, and preferably 30 m or more because the effect can be obtained more preferably. It is / min or less, more preferably 20 m / min or less. When it is less than 5 m / min and when it exceeds 30 m / min, it becomes difficult to apply a sealant material having a uniform thickness.

By using the non-contact displacement sensor, it is possible to reduce the risk of failure due to the sealant material adhering to the sensor. The non-contact displacement sensor to be used is not particularly limited as long as it can measure the distance between the inner peripheral surface of the tire and the tip of the nozzle, and examples thereof include a laser sensor, an optical sensor, and a capacitance sensor. .. These sensors may be used alone or in combination of two or more. Among them, a laser sensor and an optical sensor are preferable, and a laser sensor is more preferable, from the viewpoint of measuring rubber. When using a laser sensor, the inner peripheral surface of the tire is irradiated with a laser, the distance between the inner peripheral surface of the tire and the tip of the laser sensor is measured from the reflection of the laser, and the tip of the laser sensor and the tip of the nozzle are measured from that value. By subtracting the distance from, the distance between the inner peripheral surface of the tire and the tip of the nozzle can be obtained.

The position of the non-contact displacement sensor is not particularly limited as long as it can measure the distance between the inner peripheral surface of the tire and the tip of the nozzle before applying the sealant material, but it is preferable to attach the sealant material to the nozzle. It is more preferable to install it in a position where it does not adhere.

In addition, the number and size of non-contact displacement sensors are not particularly limited.

Since the non-contact displacement sensor is sensitive to heat, it should be protected with a heat insulating material and / or cooled with air in order to prevent the heat effect from the high temperature sealant material discharged from the nozzle. Is preferable. Thereby, the durability of the sensor can be improved.

In the description of the first embodiment, an example in which the nozzle does not move and the nozzle moves as the movement in the width direction and the radial direction of the tire has been described, but the tire may not move and the nozzle may move, and the tire and the tire may move. Both nozzles may move.

Further, it is preferable that the rotary drive device has a means for widening the width of the bead portion of the tire. When the sealant material is applied to the tire, the sealant material can be easily applied to the tire by widening the width of the bead portion of the tire. In particular, when the nozzle is introduced near the inner peripheral surface of the tire after the tire is set in the rotary drive device, the nozzle can be introduced simply by moving the nozzle in parallel, which facilitates control and improves productivity.

The means for widening the width of the bead portion of the tire is not particularly limited as long as the width of the bead portion of the tire can be widened, but two sets of devices having a plurality of (preferably two) rolls that do not change positions with each other. A mechanism or the like in which each moves in the tire width direction can be mentioned. The device may be inserted into the tire from both sides of the tire opening to widen the width of the bead portion of the tire.

In the above manufacturing method, since the sealant material that has been mixed by a twin-screw kneading extruder or the like and whose progress of the crosslinking reaction in the extruder is suppressed is applied to the inner peripheral surface of the tire as it is, the crosslinking reaction starts from the time of application. A sealant tire having good adhesiveness to the inner peripheral surface of the tire, the cross-linking reaction proceeds more preferably, and a sealant tire having a high sealing property can be produced. Therefore, it is not necessary to further crosslink the sealant tire coated with the sealant material, and good productivity can be obtained.

If necessary, a cross-linking step of further cross-linking the sealant tire coated with the sealant material may be performed.
In the cross-linking step, it is preferable to heat the sealant tire. As a result, the cross-linking speed of the sealant material can be improved, the cross-linking reaction can proceed more favorably, and the sealant tire can be manufactured with higher productivity. The heating method is not particularly limited, and a known method can be adopted, but a method using an oven is preferable. In the cross-linking step, for example, the sealant tire may be placed in an oven at 70 ° C. to 190 ° C. (preferably 150 ° C. to 190 ° C.) for 2 to 15 minutes.
It is preferable to rotate the tire in the tire circumferential direction at the time of cross-linking because the sealant material that easily flows immediately after application can prevent the flow and carry out the cross-linking reaction without deteriorating the uniformity. The rotation speed is preferably 300 to 1000 rpm. Specifically, for example, an oven with a rotating mechanism may be used as the oven.

Further, even if the cross-linking step is not performed separately, it is preferable to rotate the tire in the tire circumferential direction until the cross-linking reaction of the sealant material is completed. As a result, even a sealant material that easily flows immediately after application can be crosslinked without preventing the flow and deteriorating the uniformity. The rotation speed is the same as in the case of the cross-linking step.

In order to improve the cross-linking speed of the sealant material, it is preferable to warm the tire in advance before applying the sealant material. As a result, the sealant tire can be manufactured with higher productivity. The preheating temperature of the tire is preferably 40 to 100 ° C, more preferably 50 to 70 ° C. By setting the preheating temperature of the tire within the above range, the cross-linking reaction starts favorably from the time of application, the cross-linking reaction proceeds more favorably, and a sealant tire having a high sealing property can be produced. Further, by setting the preheating temperature of the tire within the above range, it is not necessary to carry out the cross-linking step, so that the sealant tire can be manufactured with high productivity.

Continuous kneaders (particularly twin-screw kneading extruders) generally operate continuously. On the other hand, when manufacturing a sealant tire, it is necessary to replace the tire when the application to the tire of 1 is completed. At this time, the following methods (1) and (2) may be adopted in order to manufacture a higher quality sealant tire while suppressing a decrease in productivity. The method (1) has the disadvantages of lowering the quality and the method (2) has the disadvantage of increasing the cost. Therefore, it may be used properly according to the situation.
(1) The continuous kneader and all the supply devices are operated and stopped at the same time to control the supply of the sealant material to the inner peripheral surface of the tire. All the feeders may be stopped at the same time, the tires may be replaced (preferably within 1 minute), the continuous kneader and all the feeders may be operated at the same time, and the application to the tires may be resumed. By replacing the tires promptly (preferably within 1 minute), deterioration of quality can be suppressed.
(2) The supply of the sealant material to the inner peripheral surface of the tire is controlled by switching the flow path while the continuous kneader and all the supply devices are operating. A flow path different from the nozzle that feeds directly to the tire may be provided, and when the application to one tire is completed, the prepared sealant material may be discharged from the other flow path until the tire replacement is completed. In this method, since the sealant tire can be manufactured while the continuous kneader and all the feeding devices are in operation, a higher quality sealant tire can be manufactured.

The carcass cord used for the carcass of the sealant tire is not particularly limited, and examples thereof include a fiber cord and a steel cord. Of these, steel cords are preferred. In particular, a steel cord made of a hard steel wire rod specified in JIS G3506 is desirable. In sealant tires, by using a high-strength steel cord instead of the commonly used fiber cord as the carcass cord, the side cut resistance is significantly improved (for the cut of the tire side part caused by riding on a curb, etc.). Resistance) can be improved, and the puncture resistance of the entire tire including the side portion can be further improved.

The structure of the steel cord is not particularly limited, and for example, a single-twisted steel cord having a 1 × n structure, a layer-twisted steel cord having a k + m structure, a bundle-twisted steel cord having a 1 × n structure, and a double-twisted steel having an m × n structure. Code etc. can be given. Here, the single-twisted steel cord having a 1 × n structure is a one-layer twisted steel cord obtained by twisting n filaments. The layer-twisted steel cord having a k + m structure is a steel cord having a two-layer structure having different twisting directions and twisting pitches, having k filaments in the inner layer and m filaments in the outer layer. Further, the bundled twisted steel cord having a 1 × n structure is a bundled twisted steel cord obtained by bundling and twisting n filaments. Further, the double-twisted steel cord having an m × n structure is a double-twisted steel cord obtained by twisting m strands obtained by down-twisting n filaments. n is an integer of 1 to 27, k is an integer of 1 to 10, and m is an integer of 1 to 3.

The twist pitch of the steel cord is preferably 13 mm or less, more preferably 11 mm or less, and preferably 5 mm or more, more preferably 7 mm or more.

The steel cord preferably contains at least one spirally shaped typed filament. Such a molded filament can improve rubber permeability by providing a relatively large gap in the steel cord, can maintain elongation at a low load, and can prevent the occurrence of molding defects during vulcanization molding.

The surface of the steel cord is preferably plated with brass, Zn or the like in order to improve the initial adhesiveness to the rubber composition.

The elongation of the steel cord under a load of 50 N is preferably 0.5 to 1.5%. If the elongation at 50 N load exceeds 1.5%, the elongation of the reinforcing cord becomes small at high load, and there is a possibility that the disturbance absorption cannot be maintained. On the contrary, if the elongation under the load of 50 N is less than 0.5%, the elongation cannot be sufficiently extended at the time of vulcanization molding, and molding defects may occur. From such a viewpoint, the elongation under 50 N load is more preferably 0.7% or more, and more preferably 1.3% or less.

The end of the steel cord is preferably 20 to 50 (pieces / 5 cm).

<Second Embodiment>
With only the method of the first embodiment, when the sealant material has a substantially string-like shape, it may be difficult to attach the sealant material to the inner peripheral surface of the tire. As a result of the examination by the present inventor, it has become clear that there is a problem of being easy. In the second embodiment, in the manufacturing method of the sealant tire, after attaching the sealant material and the distance between the inner circumferential surface and the tip of the nozzle of the tire at a distance d _1, the distance the distance d ₁ is larger than the distance d It is characterized by setting it to _{2 and pasting the sealant material.} As a result, by reducing the distance between the inner peripheral surface of the tire and the tip of the nozzle at the start of sticking, the width of the sealant material corresponding to the sticking start portion can be widened, and at least the tire corresponding to the tread portion. A sticky and substantially string-shaped sealant material is continuously spirally attached to the inner peripheral surface of the tire, and at least one of the end portions of the sealant material in the length direction is in the length direction. A sealant tire characterized by having a wider portion wider than a portion adjacent to the tire can be easily manufactured. In the sealant tire, by widening the width of the sealant material corresponding to the sticking start portion, the adhesive force of the portion can be improved and the peeling of the sealant material at the portion can be prevented.
In the description of the second embodiment, only the points different from those of the first embodiment will be mainly described, and the description of the contents overlapping with the first embodiment will be omitted.

5A and 5B are enlarged views of the vicinity of the tip of the nozzle constituting the coating apparatus shown in FIG. 1, where FIG. 5A shows a state immediately after the start of application of the sealant material, and FIG. 5B shows a state after a predetermined time has elapsed. There is.

FIG. 5 shows a cross section of a part of the tire 10 cut by a plane including the circumferential direction and the radial direction of the tire. In FIG. 5, the X direction is the tire width direction (axial direction), the Y direction is the tire circumferential direction, and the Z direction is the tire radial direction.

In the second embodiment, first, the tire 10 formed in the vulcanization step is set in the rotary drive device, and the nozzle 30 is inserted inside the tire 10. Then, as shown in FIGS. 1 and 5, the sealant material 20 is discharged from the nozzle 30 while rotating the tire 10 and moving the tire 10 in the width direction to continuously reach the inner peripheral surface 11 of the tire 10. Apply to the tire. The movement of the tire 10 in the width direction is performed, for example, along the profile shape of the inner peripheral surface 11 of the tire 10 that has been input in advance.

Since the sealant material 20 has adhesiveness and has a substantially string-like shape, it is continuously spirally attached to the inner peripheral surface 11 of the tire 10 corresponding to the tread portion.

At this time, as shown in FIG. 5A, the sealant material 20 is pasted _{with the distance d 1} between the inner peripheral surface 11 of the tire 10 and the tip 31 of the nozzle 30 during the predetermined time from the start of pasting. wear. Then, after a predetermined time has elapsed, as shown in FIG. 5 (b), by changing the interval distance d ₁ is greater than the distance d ₂ by moving the tire 10 radially paste sealant material 20.

_{The above interval may be returned from the distance d 2} to the distance d ₁ before the application of the sealant material is completed, but from the viewpoint of manufacturing efficiency and the weight balance of the tire, the application of the sealant material is completed. The distance to d ₂ is preferable.

Further, it is preferable to keep the value of the _{distance d 1} constant during the predetermined time from the start of pasting, _{and keep the value of the distance d 2} constant after the lapse of the predetermined time, but the relationship of _{d 1} <d _{2 is established. The values of the distances d 1} and d ₂ do not necessarily have to be constant as long as they are satisfied.

The value of the distance d ₁ is not particularly limited, but is preferably 0.3 mm or more, more preferably 0.5 mm or more, because the effect can be obtained more preferably. If it is less than 0.3 mm, the tip of the nozzle is too close to the inner peripheral surface of the tire, so that the sealant material easily adheres to the nozzle, and the nozzle may be cleaned more frequently. The value of the distance d ₁ is preferably 2 mm or less, more preferably 1 mm or less. If it exceeds 2 mm, the effect of providing the wide portion may not be sufficiently obtained.

The value of the distance d ₂ is also not particularly limited, but is preferably 0.3 mm or more, more preferably 1 mm or more, and preferably 3 mm or less, more preferably 2 mm or less because the effect can be obtained more preferably. Is. The distance d ₂ is preferably the same as the above-mentioned adjusted interval d _0.

In the present specification, the distances d ₁ and d ₂ between the inner peripheral surface of the tire and the tip of the nozzle are the distances in the radial direction of the tire between the inner peripheral surface of the tire and the tip of the nozzle.

The rotation speed of the tire when the sealant material is attached is not particularly limited, but is preferably 5 m / min or more, more preferably 10 m / min or more, and preferably 30 m or more because the effect can be obtained more preferably. It is / min or less, more preferably 20 m / min or less. If it is less than 5 m / min or more than 30 m / min, it becomes difficult to attach a sealant material having a uniform thickness.

By the above steps, the sealant tire of the second embodiment can be manufactured.
FIG. 6 is an explanatory diagram schematically showing an example of a sealant material attached to the sealant tire of the second embodiment.

The substantially string-shaped sealant material 20 is wound around the tire in the circumferential direction, and is continuously attached in a spiral shape. Then, one end of the sealant material 20 in the length direction is a wide portion 21 having a width wider than the portion adjacent to the sealant material 20 in the length direction. The wide portion 21 corresponds to the portion where the sealant material is applied.

The width of the wide portion of the sealant material because it (the width of the wide portion of the sealant material after coating, in FIG. 6, the length represented by W ₁₎ is not particularly limited, effects can be obtained more suitably, the wide portion A width other than the above (the _{length indicated by W 0} in FIG. 6) is preferably 103% or more, more preferably 110% or more, still more preferably 120% or more. If it is less than 103%, the effect of providing the wide portion may not be sufficiently obtained. The width of the wide portion of the sealant material is preferably 210% or less, more preferably 180% or less, still more preferably 160% or less of the width other than the wide portion. If it exceeds 210%, the tip of the nozzle must be brought too close to the inner peripheral surface of the tire in order to form a wide portion, so that the sealant material tends to adhere to the nozzle and the nozzle may be cleaned more frequently. There is. In addition, the weight balance of the tire may be lost.

The width of the wide portion of the sealant material is preferably substantially constant in the length direction, but there may be a portion that is not substantially constant. For example, the wide portion may have a shape in which the width of the sticking start portion is the widest and the width becomes narrower in the length direction. Here, in the present specification, when the width is substantially constant, the fluctuation of the width is 90 to 110% (preferably 97 to 103%, more preferably 98 to 102%, still more preferably 99 to 101%). It means that it fits.

The length of the wide portion of the sealant material (the length of the wide portion of the sealant material after coating, in FIG. 6, the length shown by L ₁₎ because it is not particularly limited, effects can be obtained more suitably, It is preferably less than 650 mm, more preferably less than 500 mm, still more preferably less than 350 mm, and particularly preferably less than 200 mm. If it is 650 mm or more, the time that the tip of the nozzle is brought close to the inner peripheral surface of the tire becomes long, so that the sealant material easily adheres to the nozzle, and the frequency of cleaning the nozzle may increase. In addition, the weight balance of the tire may be lost. The shorter the length of the wide portion of the sealant material, the more preferable it is, but considering controlling the distance between the inner peripheral surface of the tire and the tip of the nozzle, the limit is about 10 mm.

The width other than the wide portion of the sealant material (the width other than the wide portion of the sealant material after application _{, the length indicated by W 0} in FIG. 6) is not particularly limited, but the effect can be obtained more preferably. It is preferably 0.8 mm or more, more preferably 1.3 mm or more, still more preferably 1.5 mm or more. If it is less than 0.8 mm, the number of times the sealant material is wound around the inner peripheral surface of the tire increases, and the manufacturing efficiency may decrease. The width of the sealant material other than the wide portion is preferably 18 mm or less, more preferably 13 mm or less, further preferably 9.0 mm or less, particularly preferably 7.0 mm or less, most preferably 6.0 mm or less, and most preferably. Is 5.0 mm or less. If it exceeds 18 mm, weight imbalance may easily occur. W ₀ is preferably the same as W described above.

The width of the sealant material other than the wide portion is preferably substantially constant in the length direction, but there may be a portion that is not substantially constant.

The width of the area to which the sealant material is attached (hereinafter, also referred to as the width of the affixed area and the width of the sealant layer, the _{length represented by W 1} + 6 × W ₀ in FIG. 6) is not particularly limited, but is effective. Is more preferably 80% or more, more preferably 90% or more, further preferably 100% or more, still more preferably 120% or less, and even more preferably 110% or less of the tread contact width.

The width of the sealant layer is preferably 85 to 115%, preferably 95 to 105% of the breaker width of the tire (the length of the breaker in the tire width direction) because the effect is more preferably obtained. More preferred.

In the sealant tire of the second embodiment, the sealant materials are preferably attached so as not to overlap in the width direction, and more preferably they are attached without gaps.

Further, in the sealant tire of the second embodiment, the other end portion (the end portion corresponding to the pasting end portion) of the sealant material in the length direction is also a wide portion wider than the portion adjacent in the length direction. It may be.

The thickness of the sealant material (thickness of the sealant material after application, thickness of the sealant layer, length indicated by D in FIG. 8) is not particularly limited, but is preferable because the effect can be obtained more preferably. Is 1.0 mm or more, more preferably 1.5 mm or more, still more preferably 2.0 mm or more, particularly preferably 2.5 mm or more, and preferably 10 mm or less, more preferably 8.0 mm or less, still more preferably. It is 5.0 mm or less. If it is less than 1.0 mm, it becomes difficult to reliably close the puncture hole when the tire punctures. Further, even if it exceeds 10 mm, the effect of closing the puncture hole does not change so much and the weight of the tire increases, which is not preferable.

The thickness of the sealant material (thickness of the sealant material after application, thickness of the sealant layer) is preferably substantially constant. As a result, deterioration of tire uniformity can be further prevented, and a sealant tire having a better weight balance can be manufactured.

The thickness of the sealant material (thickness of the sealant material after application, the thickness of the sealant layer, the length indicated by D in FIG. 8) and the width other than the wide portion of the sealant material (the width of the sealant material after application). The ratio of the width other than the portion, the _{length indicated by W 0} in FIG. 6 (thickness of the sealant material / width other than the wide portion of the sealant material) is preferably 0.6 to 1.4, more preferably. It is 0.7 to 1.3, more preferably 0.8 to 1.2, and particularly preferably 0.9 to 1.1. The closer the ratio is to 1.0, the more the shape of the sealant material becomes an ideal string-like shape, and a sealant tire having a high sealing property can be manufactured with higher productivity.

The cross-sectional area of the sealant material (cross-sectional area of the sealant material after coating, the area calculated by D × W in FIG. 8) is preferably 0.8 mm ² or more because the effect can be obtained more preferably. preferably 1.95 mm ² or more, more preferably 3.0 mm ² or more, particularly preferably 3.75 mm ² or more, preferably 180 mm ² or less, more preferably 104 mm ² or less, more preferably 45 mm ² or less, particularly preferably Is 35 mm ² or less, most preferably 25 mm ² or less.

In the second embodiment, even if the viscosity of the sealant material is within the above range, particularly even if the viscosity is relatively high, by widening the width of the sealant material corresponding to the attachment start portion, the portion is adhered. It is possible to improve the force and prevent the sealant material from peeling off at the portion.

The sealant tire of the second embodiment is preferably manufactured by the above-mentioned manufacturing method, but is manufactured by any other suitable manufacturing method as long as at least one end of the sealant material can be a wide portion. May be good.

In the above description, in particular, in the description of the first embodiment, the case where the non-contact displacement sensor is used when applying the sealant material to the inner peripheral surface of the tire has been described, but the measurement is performed by the non-contact displacement sensor. Instead, the sealant material may be applied to the inner peripheral surface of the tire by controlling the movement of the nozzle and / or the tire based on the coordinate values input in advance.

A sealant tire having a sealant layer inside the inner liner in the tire radial direction can be manufactured by the above-mentioned manufacturing method or the like. In particular, the sealant layer is coated on the inner peripheral surface of the vulcanized tire because it is less likely to cause problems due to the flow of the sealant material and can be handled by programming even if the tire size changes. It is preferable that the tire is formed by a manufacturing method. Further, because the sealant material is easy to handle and has high productivity, it is formed by a manufacturing method in which the sealant material sequentially prepared by mixing the raw materials containing the cross-linking agent with a continuous kneader is sequentially applied to the inner peripheral surface of the tire. It is preferable that the tire is made.

The present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

The various chemicals used in the examples will be described below.
Butyl rubber: Regular butyl 065 (manufactured by Nippon Butyl Co., Ltd., Mooney viscosity at 125 ° C. ML1 + 8 = 32)
Liquid polybutene: liquid polybutene A (Nippon Polybutene HV300 (JX Nippon Oil & Energy Ltd., dynamic viscosity 590 mm ² / s in kinematic viscosity 26,000mm ² / s, 100 ℃ at 40 ° C., a number average molecular weight 1,400)) and , liquid polybutene B (Nisseki polybutene HV1900 (JX Nippon Oil & energy Ltd., dynamic viscosity 3,710mm ² / s in kinematic viscosity 160,000mm ² / s, 100 ℃ at 40 ° C., a number average molecular weight 2,900)) Carbon black: N330 (manufactured by Cabot Japan Co., Ltd., HAF grade, DBP oil absorption 102 ml / 100 g)
Crosslinking aid: Barnock GM (manufactured by Ouchi Shinko Kagaku Co., Ltd., p-benzoquinone dioxime)
Cross-linking agent: NOF NS (manufactured by NOF CORPORATION, dibenzoyl peroxide (40% diluted product, dibenzoyl peroxide: 40% dibutyl phthalate: 48%), the amount in Table 1 is the amount of pure benzoyl peroxide)

(Example)
<Manufacturing of sealant tires>
According to the formulation shown in Table 1, butyl rubber, carbon black and a cross-linking aid are supplied from the upstream side supply port of the twin-screw kneading extruder, liquid polybutene B is provided from the middle stream supply port, and liquid polybutene A and the cross-linking agent are provided from the downstream supply port. The sealant material was prepared by charging and kneading under the conditions of a barrel temperature of 100 ° C. and 200 rpm. As for the liquid polybutene, the liquid polybutene at 50 ° C. was charged from the supply port.
(Kneading time of each material)
Mixing time of butyl rubber, carbon black and cross-linking aid: 2 minutes Mixing time of liquid polybutene B: 2 minutes Mixing time of liquid polybutene A and cross-linking agent: 1.5 minutes

Tires attached to the rotary drive (215 / 55R17, 94W, rim: 17X8J, cavity cross-sectional area when the tire rim is assembled: 194 cm ² , vulcanized, tire rotation speed 12 m / min, preheating temperature: 40 ° C, tire breaker A sealant material (viscosity 10000 Pa · s (40 ° C.), substantially string-shaped) is attached to a width: 180 mm), and the sealant material (temperature 100 ° C.) prepared sequentially is biaxially kneaded so that the width of the area to be attached is 180 mm. It was extruded from an extruder and continuously spirally attached to the inner peripheral surface of the tire according to FIGS. 1 to 4 (applied in a spiral shape) through a nozzle to form a first sealant layer. Further, a sealant material was attached to the inside of the formed sealant layer in the radial direction of the tire by the same operation to form a second sealant layer.
The width of the sealant material was adjusted so as to be substantially constant in the length direction. Further, the thickness and displacement of the sealant layer and the width of the sealant material were adjusted so as to have the values shown in Table 2.
Overall tire cavity volume: 36600 cm ³

(Comparison example)
In Comparative Example 1, the sealant layer is not formed.

The obtained sealant tires were evaluated as follows.

<Test 1 (Rip resistance of sealant layer)>
The initial internal pressure of the tire was set to 250 kPa, and at an atmospheric temperature of 0 ° C., 20 nails (body diameter 5.2 mm) processed to 50 mm were driven into the block part of the tire to the head and left for 1 hour. Later, the nails were removed, the tire was left at an atmospheric temperature of 0 ° C. for a whole day, the rim of the tire was removed, and the number of tears in the sealant layer was confirmed.
The smaller the index, the better the tear resistance of the sealant layer.

<Test 2 (sealability after running)>
The initial internal pressure of the tire was set to 250 kPa, and at an atmospheric temperature of 25 ° C, 20 nails (body diameter 5.2 mm) processed to 50 mm were driven into the block of the tire to the head, and the atmospheric temperature was 25 ° C. After running the 750km drum under the conditions of speed 150km / h and load 4.2kN, the nails were removed, the tires were left at an ambient temperature of 25 ° C for a whole day, and soapy water was applied to leak air. The number of nail holes was confirmed.
The larger the index, the better the sealing property after running.

<Test 3 (sealing property at low temperature)>
After running the drum under the same conditions as in Test 2, leave the tires in a room with an ambient temperature of -10 ° C for 12 hours, remove the nails, and then apply soapy water to check the number of nail holes that do not leak air. did.
The larger the index, the better the sealing property at low temperature.

A pneumatic tire having a sealant layer inside the inner liner in the tire radial direction, wherein the sealant layer has a structure in which a first sealant layer and a second sealant layer are laminated in this order from the inner liner side. The first sealant layer is composed of a substantially string-shaped sealant material continuously spirally arranged along the inner peripheral surface of the tire, and the second sealant layer is formed on the first sealant layer. The sealant material is composed of a substantially string-shaped sealant material continuously spirally arranged along the line, and the sealant material forming the first sealant layer and the sealant material forming the second sealant layer are composed of the sealant material. The pneumatic tires (sealant tires) of the embodiment, which are arranged in the same circumferential direction and shifted in the tire width direction, are substantially spirally arranged continuously along the inner peripheral surface of the tire. Even the sealant layer made of a string-shaped sealant material had excellent tear resistance.

Further, the tire is a pneumatic tire having a sealant layer inside the inner liner in the radial direction of the tire, and the sealant layer has a configuration in which the first sealant layer and the second sealant layer are laminated in this order from the inner liner side. However, the pneumatic tire having a viscosity of the first sealant layer lower than the viscosity of the second sealant layer had good levels of sealing performance after running and sealing performance at low temperature.

10 Tire 11 Tire inner peripheral surface 14 Tread part 15 Carcass 16 Breaker 17 Band 19 Inner liner 20 Sealant material 21 Wide part 22 Sealant layer 22a First sealant layer 22b Second sealant layer 30 Nozzle 31 Nozzle tip 40 Non-contact displacement Sensor 50 Rotation drive device 60 Biaxial kneading extruder 61 (61a 61b 61c) Supply port 62 Material feeder d, d ₀ , d ₁ , d ₂ Distance between the inner peripheral surface of the tire and the tip of the nozzle A Nail

Claims (5)

A pneumatic tire that has a sealant layer inside the inner liner in the radial direction of the tire.
The sealant layer has a structure in which the first sealant layer and the second sealant layer are laminated in this order from the inner liner side.
The first sealant layer is composed of a substantially string-shaped sealant material that is continuously spirally arranged along the inner peripheral surface of the tire.
The second sealant layer is composed of a substantially string-shaped sealant material which is continuously spirally arranged along the first sealant layer.
A pneumatic tire in which the sealant material forming the first sealant layer and the sealant material forming the second sealant layer are arranged in the same circumferential direction and are arranged so as to be offset in the tire width direction. The sealant material forming the first sealant layer and the sealant material forming the second sealant layer have substantially the same width W and are 2 mm to 5 mm, and form the first sealant layer. The pneumatic tire according to claim 1 _{, wherein the deviation d gap} between the sealant material and the sealant material constituting the second sealant layer in the tire width direction satisfies the following formula.
[W / 4] ≤d _gap ≤ [W / 2] The pneumatic tire according to claim 1 or 2, wherein the first sealant layer and the second sealant layer have different viscosities. The pneumatic tire according to any one of claims 1 to 3, wherein the viscosity of the first sealant layer is lower than the viscosity of the second sealant layer. The pneumatic tire according to any one of claims 1 to 4, wherein the thickness of the first sealant layer and the thickness of the second sealant layer are different.

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