Pneumatic tires, methods for manufacturing pneumatic tires

Abstract

This invention provides a pneumatic tire equipped with a sealant layer and a sound-absorbing layer, which is highly effective in suppressing the deterioration of puncture resistance. [Solution] The tire 1 comprises a pair of beads 10, a pair of sidewalls 20 extending radially outward from each of the pair of beads 10, a tread 30 positioned between the pair of sidewalls 20 and having a contact surface 331, a carcass ply 40 spanning between the pair of beads 10, an inner liner 50 positioned on the inner cavity side of the carcass ply 40, a sealant layer 60 positioned on the inner surface of the inner liner 50 on the inner cavity side of the sealant layer 60, and a sound-absorbing layer 70 positioned on the inner cavity side of the sealant layer 60, wherein the sound-absorbing layer 70 partially has a bonding suppression portion 75 on the side facing the sealant layer 60 to suppress bonding with the sealant layer 60.

Description

Technical Field

[0001] The present disclosure relates to a pneumatic tire and a method for manufacturing a pneumatic tire.

Background Art

[0002] Conventionally, a pneumatic tire having a puncture prevention function in which a hole in the tire formed when a foreign object such as a nail pierces the tire is automatically blocked by a sealant layer provided on the inner surface of the tire is known. For example, Patent Document 1 describes a pneumatic tire in which a sealant layer is provided on the inner surface of the tire and a sound deadening body is provided inside the sealant layer. It is known that when the sealant layer and the sound deadening body are adhered, the puncture resistance performance deteriorates. Therefore, in the pneumatic tire of Patent Document 1, when a foreign object penetrating the tread portion contacts the sound deadening body, a technique for suppressing a decrease in air seal performance by peeling the sound deadening body from the sealant layer is disclosed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the above Patent Document 1, since the sound deadening body peels off due to a foreign object penetrating the tread portion, there is a possibility that the sound deadening effect cannot be maintained, or the peeled sound deadening body scatters into the tire, resulting in an increase in noise or the generation of abnormal noise.

[0005] An object of the present disclosure is to provide a pneumatic tire including a sealant layer and a sound absorbing layer, which has a high effect of suppressing a decrease in puncture resistance performance.

Means for Solving the Problems

[0006] The pneumatic tire of this disclosure comprises a pair of beads, a pair of sidewalls extending radially outward from each of the pair of beads, a tread having a contact surface and positioned between the pair of sidewalls, a carcass ply spanning between the pair of beads, an inner liner positioned on the inner side of the carcass ply towards the inner cavity of the tire, a sealant layer positioned on the inner surface of the inner liner towards the inner cavity of the tire, and a sound-absorbing layer positioned on the inner side of the sealant layer towards the inner cavity of the tire, wherein the sound-absorbing layer partially has a bonding-restricting portion on the side facing the sealant layer that suppresses bonding with the sealant layer. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a pneumatic tire that includes a sealant layer and a sound-absorbing layer, and is highly effective in suppressing the deterioration of puncture resistance. [Brief explanation of the drawing]

[0008] [Figure 1] This figure shows a cross-sectional view in the axial direction of tire 1, which is a pneumatic tire according to this embodiment. [Figure 2] This is a diagram illustrating the manufacturing method of tire 1. [Figure 3] This is a diagram illustrating the manufacturing method of tire 1. [Figure 4] This is a diagram illustrating the manufacturing method of tire 1. [Modes for carrying out the invention]

[0009] The embodiments will be described below with reference to the drawings. Figure 1 is a diagram showing a cross-sectional view in the axial direction of tire 1, which is a pneumatic tire according to this embodiment. Tire 1 is, for example, a tire for a passenger car. The basic structure of tire 1 is symmetrical in the cross-section in the axial direction of tire 1. In the figure, the symbol S1 is the tire equatorial plane. The tire equatorial plane S1 is a plane that is perpendicular to the tire rotation axis (tire meridian) and is located at the center in the axial direction of tire 1.

[0010] The cross-sectional view in Figure 1 is an axial cross-sectional view (tire meridian cross-section) of the tire in an unloaded state, with tire 1 mounted on a specified rim and filled to the specified internal pressure. The specified rim refers to the standard rim defined by JATMA corresponding to the tire size. The specified internal pressure is, for example, 180 kPa if the tire is for a passenger car.

[0011] Here, the tire axis direction is the direction parallel to the tire rotation axis, and in the cross-sectional view of Figure 1, it is the left-right direction on the paper. In Figure 1, it is shown as the tire axis direction X. The inner direction in the tire axis direction is the direction approaching the tire equatorial plane S1, and in Figure 1, it is the center side of the paper. The outer direction in the tire axis direction is the direction away from the tire equatorial plane S1, and in Figure 1, it is the left and right sides of the paper. The tire radial direction is the direction perpendicular to the tire rotation axis, and in Figure 1, it is the up-down direction on the paper. In Figure 1, it is shown as the tire radial direction Y. The outer direction in the tire radial direction is the direction away from the tire rotation axis, and in Figure 1, it is the bottom side of the paper. The inner direction in the tire radial direction is the direction approaching the tire rotation axis, and in Figure 1, it is the top side of the paper.

[0012] As shown in Figure 1, the tire 1 comprises a pair of beads 10 provided on both sides of the tire axial direction, a pair of sidewalls 20 extending radially outward from each of the pair of beads 10, a tread 30 positioned between the pair of sidewalls 20, a carcass ply 40 positioned between the pair of beads 10, and an inner liner 50 positioned on the inner side of the carcass ply 40.

[0013] The bead 10 comprises a bead core 11, a bead filler 12 extending radially outward from the bead core 11, a chaff 13, and a rim strip rubber 14.

[0014] The bead core 11 is an annular member formed by winding a rubber-coated metal bead wire multiple times, and is a member that fixes the air-filled tire 1 to the rim. The bead filler 12 is a rubber member that tapers towards the outside in the radial direction of the tire. The bead filler 12 is a member provided to increase the rigidity of the peripheral part of the bead 10 and ensure high maneuverability and stability. The bead filler 12 is made of rubber that is harder than the surrounding rubber member, for example.

[0015] The chaff 13 is located on the radially inner side of the carcass ply 40, which is provided around the bead core 11. The rim strip rubber 14 is positioned on the axially outer side of the chaff 13 and carcass ply 40. The rim strip rubber 14 is a component that contacts the rim on which the tire 1 is mounted.

[0016] The sidewall 20 includes sidewall rubber 21 positioned on the axial side of the carcass ply 40. The sidewall rubber 21 constitutes the outer wall surface of the tire 1. The sidewall rubber 21 is the part that flexes the most when the tire 1 performs its cushioning action, and is usually made of a flexible rubber with fatigue resistance.

[0017] The tread 30 comprises an endless belt 31 and a cap ply 32, and tread rubber 33.

[0018] The belt 31 is positioned on the radially outer side of the carcass ply 40. The cap ply 32 is positioned on the radially outer side of the belt 31. The belt 31 is a member that reinforces the tread 30. In this embodiment, the belt 31 has a two-layer structure comprising an inner belt and an outer belt 312. Both the inner belt 311 and the outer belt 312 have a structure in which multiple steel cords or the like are covered with rubber. Note that the belt 31 is not limited to a two-layer structure; it may also have a one-layer structure or a structure with three or more layers.

[0019] The cap ply 32 is a member that reinforces the tread 30 together with the belt 31. The cap ply 32 has a structure in which a plurality of insulating organic fiber cords, such as polyamide fibers, are covered with rubber. By providing the cap ply 32, it is possible to improve durability and reduce road noise during driving.

[0020] The tread rubber 33 is disposed on the outer side in the tire diameter direction of the cap ply 32. The tread rubber 33 is a member that constitutes the ground contact surface (tread surface) 331 during normal driving. The ground contact surface 331 of the tread rubber 33 is provided with a tread pattern 34 composed of, for example, a plurality of grooves. The tread pattern 34 has a plurality of main grooves 341 arranged in the tire axial direction. Each of the plurality of main grooves 341 extends along the tire circumferential direction.

[0021] The carcass ply 40 constitutes a ply that forms the skeleton of the tire 1. The carcass ply 40 is embedded in the tire 1 in a manner that passes between a pair of beads 10 through a pair of sidewalls 20 and the tread 30. The carcass ply 40 includes a plurality of carcass cords that form the skeleton of the tire 1. The plurality of carcass cords extend, for example, in the tire axial direction and are arranged side by side in the tire circumferential direction. The carcass cords are composed of insulating organic fiber cords such as polyester and polyamide. The plurality of carcass cords are covered with rubber to form the carcass ply 40.

[0022] The carcass ply 40 has a ply main body portion 401 that extends from one bead core 11 to the other bead core 11 and extends between the tread 30 and the bead 10, a pair of bent portions 402 that are folded back by the bead core 11 from the ply main body portion 401, and a pair of folded-back portions 403 that extend outward in the tire diameter direction from each of the bent portions 402. The ply main body portion 401, the bent portions 402, and the folded-back portions 403 are continuous.

[0023] The ply body portion 401 is positioned radially inward of the tire and axially inward of the bead core 11 and bead filler 12. The folded portion 403 is positioned radially inward of the tire and axially outward of the bead core 11 and bead filler 12. In portions other than the bead core 11 and bead filler 12, the folded portion 403 is superimposed on the ply body portion 401. The bent portion 402 constitutes the innermost part of the carcass ply 40 in the radial direction of the tire.

[0024] Although the carcass ply 40 in this embodiment has a single-layer structure, the carcass ply 40 is not limited to a single-layer structure; it may have a two-layer structure or a structure with three or more layers.

[0025] The bead 10's chamfer 13 is provided to surround the inner end of the carcass ply 40 in the tire radial direction, including the bent portion 402. The rim strip rubber 14 is positioned on the tire axial side outward from the chamfer 13 and the folded portion 403 of the carcass ply 40. The outer end of the rim strip rubber 14 in the tire radial direction is covered with the sidewall rubber 21 described above.

[0026] The inner liner 50 covers the inner surface of the tire between the pair of beads. The inner liner 50 covers the inner surface of the ply body 401 of the carcass ply 40 and the inner surface of the chamfer 13 of the pair of beads 10. The inner liner 50 is made of air-permeable rubber to prevent air from leaking out of the tire cavity.

[0027] As shown in Figure 1, the tire 1 according to this embodiment further comprises a sealant layer 60 and a sound-absorbing layer 70.

[0028] The sealant layer 60 is positioned on the inner surface 501 of the inner liner 50 that is at least on the inner side of the tire cavity corresponding to the tread 30. The sealant layer 60 is attached to the inner liner 50 by its own adhesive properties. The thickness of the sealant layer 60 is, for example, about 1 mm to 10 mm. By providing the sealant layer 60, if a hole is created in the tread 30 that reaches the sealant layer 60, for example, when a nail is driven into it, the hole is automatically sealed by the sealant layer 60, preventing a puncture.

[0029] A sealant material (sealant) that is a fluid with adhesive properties can be used to form the sealant layer 60. Conventional sealant materials known for puncture sealing can be used as the sealant material for the sealant layer 60. Examples of sealant materials that can be used for the sealant layer 60 include silicone compounds, styrene compounds, urethane compounds, and ethylene compounds. More specifically, an adhesive sealant material can be used, which is made by blending unvulcanized or semi-vulcanized butyl rubber with a plasticizer such as polyisobutylene or polybutene, a tackifier such as a thermoplastic olefin / diolefin copolymer, and a filler such as carbon black or silica. However, the sealant material is not limited to these, and other conventionally used and known sealant materials (sealants) may also be used to form the sealant layer 60.

[0030] The sound-absorbing layer 70 is positioned on the inner surface 601 of the sealant layer 60 on the inner side of the tire cavity. The sound-absorbing layer 70 is attached to the sealant layer 60 by the adhesive properties of the sealant layer 60. The material (sound-absorbing material) constituting the sound-absorbing layer 70 in this embodiment is a sponge with numerous pores formed from a foamed material, and a foamed resin such as polyurethane foam is preferably used. The sound-absorbing layer 70 in this embodiment has a substantially rectangular cross-sectional shape in the tire axial cross-section shown in Figure 1, and is positioned symmetrically with respect to the tire equatorial plane S1 as the central plane of symmetry.

[0031] The sound-absorbing layer 70 is constructed by attaching at least one sheet-like sound-absorbing material in a substantially ring shape along the inner surface 601 of the sealant layer 60. The sound-absorbing layer 70 can be constructed by joining the ends of a single sound-absorbing material along the inner surface 601 of the sealant layer 60 in the circumferential direction of the tire in a substantially ring shape. The sound-absorbing layer 70 may also be constructed in an annular shape with two or more members divided in the circumferential direction of the tire, or it may be arranged intermittently in the circumferential direction of the tire at predetermined intervals rather than in an annular shape. Alternatively, a single sound-absorbing material that has been pre-formed into an annular shape may be joined to the inner surface 601 of the sealant layer 60. By providing the sound-absorbing layer 70, it is possible to reduce in-vehicle noise by reducing cavity resonance that occurs in the tire cavity and absorbing road noise during driving.

[0032] In order for the sealant layer 60 to prevent punctures, it is necessary for the sealant layer 60 to be deformable. However, in areas where the sealant layer 60 and the sound-absorbing layer 70 are firmly bonded, the sound-absorbing layer 70 may inhibit or suppress the deformation of the sealant layer 60, raising concerns about a decrease in the puncture resistance performance that the sealant layer 60 is supposed to provide.

[0033] Therefore, in the tire 1 of this embodiment, the deterioration of puncture resistance is suppressed by providing a bonding suppression portion 75 in the sound-absorbing layer 70. This point will be explained in detail below.

[0034] The sound-absorbing layer 70 has a bonding suppression portion 75 on the side facing the sealant layer 60 that suppresses bonding between the sealant layer 60 and the sound-absorbing layer 70. Specifically, the bonding suppression portion 75 in this embodiment is provided in the region on the inner side of the sound-absorbing layer 70, i.e., in the region on the inner side of the tire axial direction, rather than at both ends (ends 71, 71) of the sound-absorbing layer 70 in the tire axial direction in the cross section of the tire.

[0035] The bonding suppression portion 75 in this embodiment is a region on the sound-absorbing layer 70 to which a release agent is partially applied. That is, the bonding suppression portion 75 is formed by applying a release agent to the sound-absorbing layer 70. Therefore, the bonding suppression portion 75 in this embodiment is formed on the surface of the sound-absorbing layer 70 on the sealant layer 60 side and penetrates to some extent into an unillustrated void provided in the sound-absorbing layer 70. Note that in Figure 1 and other figures, the thickness of the bonding suppression portion 75 is exaggerated for ease of understanding, but in reality, it is formed thinly on the sound-absorbing layer 70.

[0036] As the release agent for forming the bonding inhibition portion 75, for example, fluorine-based release agents, oil / wax-based release agents, silicone-based release agents, surfactant-based release agents, etc., can be used. Furthermore, the material that can be used as the bonding inhibition portion 75 is not limited to release agents; lubricants can also be used as substitutes, for example, semi-solid lubricants such as grease may be used.

[0037] Furthermore, it is desirable that the bonding suppression portion 75 be made of a material that is highly effective in suppressing bonding between the sealant layer 60 and the sound-absorbing layer 70. Therefore, for example, if the sealant layer 60 is made of a silicone-based material, it is desirable that the bonding suppression portion 75 be made of a non-silicone-based material.

[0038] The inner surface 601 of the sealant layer 60 in this embodiment has an inner opposing region 601a, an outer opposing region 601b, 601b, and a non-opposing region 601c, 601c.

[0039] The inner opposing region 601a is the region where the sealant layer 60 and the sound-absorbing layer 70 face each other via the bonding suppression portion 75, and is the region inward in the tire axial direction from both ends (ends 71, 71) of the sound-absorbing layer 70 in the tire axial direction in the tire axial cross-section. The inner opposing region 601a is the region from the position through which the tire equatorial plane S1 passes, that is, the position which is the center in the tire axial direction, outward in the tire axial direction, to both ends of the bonding suppression portion 75 in the tire axial direction.

[0040] The outer opposing regions 601b, 601b are regions where the sealant layer 60 and the sound-absorbing layer 70 face each other, and in the tire axial cross-section, they are regions that are further outward in the tire axial direction than the inner opposing region 601a, and further inward in the tire axial direction than both ends (ends 71, 71) of the sound-absorbing layer 70. The width in the tire axial direction of one outer opposing region 601b is approximately equal to the width in the tire axial direction of the other outer opposing region 601b.

[0041] The non-opposing regions 601c, 601c are located further outward in the tire axial direction than the outer opposing regions 601b, 601b, and are regions that do not face the sound-absorbing layer 70. The width in the tire axial direction of one non-opposing region 601c is approximately equal to the width in the tire axial direction of the other non-opposing region 601c.

[0042] Both the inner opposing region 601a and the outer opposing regions 601b, 601b are positioned opposite the sound-absorbing layer 70. However, in the inner opposing region 601a, the sealant layer 60 and the sound-absorbing layer 70 face each other via the bonding suppression portion 75. Therefore, the bonding force between the sealant layer 60 and the sound-absorbing layer 70 is higher in the outer opposing regions 601b, 601b than in the inner opposing region 601a. ​​In this embodiment, in the outer opposing regions 601b, 601b, where the sealant layer 60 and the sound-absorbing layer 70 are in contact, the sealant layer 60 and the sound-absorbing layer 70 are bonded together. On the other hand, in the inner opposing region 601a, the sealant layer 60 and the sound-absorbing layer 70 are in contact, but bonding is suppressed or inhibited by the bonding suppression portion 75, so they are not substantially bonded together. Note that the state of not substantially bonded together includes not only the case where the bonding force between the two is zero, but also the case where they are in contact with a slight bonding force due to intermolecular forces, etc.

[0043] In other words, in the inner opposing region 601a, the bonding force between the sealant layer 60 and the sound-absorbing layer 70 is zero or very small. Therefore, the sound-absorbing layer 70 does not suppress the deformation of the sealant layer 60, or the sound-absorbing layer 70 has almost no effect in suppressing the deformation of the sealant layer 60. Consequently, the decrease in puncture resistance can be suppressed in the inner opposing region 601a.

[0044] Furthermore, by providing the outer opposing regions 601b, 601b, the sound-absorbing layer 70 is properly fixed within the tire cavity, and a stable noise suppression effect during driving can be obtained. In the outer opposing regions 601b, 601b, there is a risk of a decrease in puncture resistance, so it is desirable that the width of the outer opposing regions 601b, 601b in the tire axial direction be narrow in order to suppress the decrease in puncture resistance. On the other hand, from the viewpoint of fixing the sound-absorbing layer 70, it is desirable that the width of the outer opposing regions 601b, 601b in the tire axial direction be wide. Therefore, it is important to set the width of the outer opposing regions 601b, 601b in the tire axial direction to an appropriate value.

[0045] The width in the tire axial direction of the outer opposing regions 601b, 601b that face each other at both ends (ends 71, 71) of the sound-absorbing layer 70 is preferably between 10% and 30% of the tire axial direction width of the sound-absorbing layer 70. If the tire axial direction width of the outer opposing regions 601b, 601b is less than 10% of the tire axial direction width of the sound-absorbing layer 70, the fixing of the sound-absorbing layer 70 may become unstable. Also, if the tire axial direction width of the outer opposing regions 601b, 601b exceeds 30% of the tire axial direction width of the sound-absorbing layer 70, the proportion occupied by the outer opposing regions 601b, 601b becomes too large, which may reduce the puncture resistance performance of the sealant layer 60.

[0046] In this embodiment, the width of the outer opposing regions 601b, 601b in the tire axial direction is 15% of the width of the sound-absorbing layer 70 in the tire axial direction.

[0047] Furthermore, it is desirable that the width in the tire axial direction of the outer opposing regions 601b, 601b that face each other at both ends (ends 71, 71) of the sound-absorbing layer 70 be between 10 mm and 20 mm. If the width in the tire axial direction of the outer opposing regions 601b, 601b is less than 10 mm, the fixing of the sound-absorbing layer 70 may become unstable. Also, if the width in the tire axial direction of the outer opposing regions 601b, 601b exceeds 20 mm, the proportion occupied by the outer opposing regions 601b, 601b becomes too large, which may reduce the puncture resistance performance of the sealant layer 60.

[0048] In this embodiment, the width of the outer opposing regions 601b, 601b in the tire axial direction is 12.5 mm each.

[0049] Furthermore, it is desirable that the width of the inner opposing region 601a is greater than the width of the outer opposing region 601b. That is, it is desirable that the relationship (width of inner opposing region 601a) > (width of outer opposing region 601b) is satisfied. By satisfying the above relationship, the possibility of exhibiting puncture resistance can be increased.

[0050] Furthermore, it is desirable that the width of the inner opposing region 601a is greater than the combined width of the two outer opposing regions 601b, 601b. In other words, it is desirable that the relationship (width of inner opposing region 601a) > 2 × (width of outer opposing region 601b) is satisfied. By satisfying the above relationship, the possibility of achieving puncture resistance can be increased.

[0051] Furthermore, the sealant layer 60 is positioned to be further outward in the tire axial direction than all of the main grooves 341. The main grooves 341 are areas where the thickness of the tread rubber 33 in the tire radial direction is thinner than other parts, making them highly susceptible to punctures by foreign objects. By positioning the sealant layer 60 to be further outward in the tire axial direction than all of the main grooves 341, the sealant layer 60 is positioned on the inner side of the tire cavity of all the main grooves 341, thereby increasing the likelihood of achieving puncture resistance.

[0052] Furthermore, it is desirable that the inner opposing region 601a be positioned to be further outward in the tire axial direction than all of the main grooves 341. In other words, it is desirable that the bonding suppression portion 75 be positioned to be further outward in the tire axial direction than all of the main grooves 341. With this arrangement, the deformation of the sealant layer 60, which is located on the inner lumen side of all the main grooves 341, is not hindered by the sound-absorbing layer 70, and a decrease in puncture resistance can be suppressed.

[0053] Furthermore, the sealant layer 60 is positioned further outward from the belt 31 in the tire axial direction. This allows the sealant layer 60 to cover almost the entire area of ​​the tire cavity where there is a high risk of foreign objects puncturing it, thereby increasing the likelihood of achieving puncture resistance.

[0054] Furthermore, the sealant layer 60 is positioned further outward from the cap ply 32 in the tire axial direction. This allows the sealant layer 60 to cover almost the entire area of ​​the tire cavity where there is a high risk of foreign objects puncturing it, thereby increasing the likelihood of achieving puncture resistance.

[0055] Furthermore, the axial width of the non-opposing regions 601c and 601c is wider than the axial width of the outer opposing regions 601b and 601b, respectively. This increases the likelihood that the sealant layer 60 will not have its deformation suppressed by the sound-absorbing layer 70 over a wider area, thereby allowing it to exhibit puncture resistance.

[0056] (Manufacturing method) Next, the manufacturing method of the tire 1 of this embodiment will be described. Figures 2 to 4 are diagrams illustrating the manufacturing method of the tire 1. The manufacturing method of the tire 1 will be described below with reference to Figures 2 to 4.

[0057] (Step of applying the material constituting the bonding suppression part 75 to the sound-absorbing layer 70) First, a material constituting a partial bonding suppression portion 75 is applied to the side of the sound-absorbing layer 70 facing the sealant layer 60 (see Figure 2). In this embodiment, a release agent is applied to the sound-absorbing layer 70 near the center in the width direction. Although Figure 2 shows the release agent being applied with a roller, this is just one example, and the release agent may be applied by other methods, such as spraying. If necessary, further steps may be provided to dry or harden the applied release agent.

[0058] (Sealant application step) The remaining parts of the tire 1 that do not have the sealant layer 60 and the sound-absorbing layer 70 are manufactured in advance by a conventionally known manufacturing method. Then, a sealant material that will form the base of the sealant layer 60 is applied to the inner surface 501 of the inner liner 50 using a nozzle (not shown) or the like (see Figure 3). For example, the sealant material may be discharged from the nozzle onto the inner surface 501 of the inner liner 50 while the tire 1 is rotated around its axis and the nozzle is moved in the axial direction of the tire. This sealant material application step may be performed before the step of applying the material constituting the bonding suppression part 75 to the sound-absorbing layer 70, or after the step of applying the material constituting the bonding suppression part 75 to the sound-absorbing layer 70.

[0059] (Step of joining the sound-absorbing layer 70) Next, before the sealant applied to the inner surface 501 on the inner side of the tire cavity hardens, the sound-absorbing layer 70 is placed on top of the sealant layer 60 (sealant material) with the bonding suppression portion 75 of the sound-absorbing layer 70 facing each other (see Figure 4). After placing the sound-absorbing layer 70, if necessary, the sound-absorbing layer 70 may be pressed outward in the radial direction of the tire, i.e., toward the sealant layer 60. The unhardened sealant material and the vicinity of the ends 71, 71 of the sound-absorbing layer 70 are superimposed, and then, as the sealant material hardens, the sealant layer 60 and the sound-absorbing layer 70 are bonded together in the area where the bonding suppression portion 75 of the sound-absorbing layer 70 is not placed. That is, the sealant layer 60 and the sound-absorbing layer 70 are bonded together in the outer opposing region 601b of the sealant layer 60. On the other hand, in the region where the bonding suppression portion 75 of the sound-absorbing layer 70 is located, the bonding suppression portion 75 prevents the sealant layer 60 and the sound-absorbing layer 70 from bonding, and the sealant layer 60 and the sound-absorbing layer 70 do not adhere to each other. In other words, the sealant layer 60 and the sound-absorbing layer 70 do not adhere to each other in the inner opposing region 601a of the sealant layer 60.

[0060] This configuration can be more clearly understood by disassembling the tire 1 and peeling the sound-absorbing layer 70 from the sealant layer 60. Specifically, in the outer opposing regions 601b, 601b, the sealant layer 60 and the sound-absorbing layer 70 are bonded together, while in the inner opposing region 601a, the sealant layer 60 and the sound-absorbing layer 70 are facing each other in a state where they can be peeled off via the bonding suppression portion 75. Therefore, if the sound-absorbing layer 70 is forcibly peeled off from the sealant layer 60, in the outer opposing regions 601b, 601b, the sealant layer 60 or the sound-absorbing layer 70 will be partially damaged, and it will not peel off cleanly. In contrast, in the inner opposing region 601a, the sealant layer 60 and the sound-absorbing layer 70 can be easily peeled off cleanly.

[0061] The tire 1 according to the embodiment described above provides the following effects.

[0062] (1) The tire 1 according to this embodiment comprises a pair of beads 10, a pair of sidewalls 20 extending radially outward from each of the pair of beads 10, a tread 30 disposed between the pair of sidewalls 20 and having a contact surface 331, a carcass ply 40 spanning between the pair of beads 10, an inner liner 50 disposed on the inner side of the carcass ply 40 on the inner side of the inner liner 50 on the inner side of the inner liner 50, and a sound-absorbing layer 70 disposed on the inner side of the sealant layer 60, wherein the sound-absorbing layer 70 partially has a bonding suppression portion 75 on the side facing the sealant layer 60 that suppresses bonding with the sealant layer 60.

[0063] This makes it possible to provide a pneumatic tire that effectively prevents or suppresses adhesion between the sealant layer 60 and the sound-absorbing layer 70 by having the bonding suppression portion 75 prevent or suppress adhesion, thereby suppressing a decrease in puncture resistance.

[0064] (2) A pneumatic tire as described in (1), wherein the bonding suppression portion 75 is provided in a region inside the sound-absorbing layer 70, in the tire axial cross section, beyond both ends of the sound-absorbing layer 70 in the tire axial direction.

[0065] This makes it possible to enhance the effect of suppressing the decrease in puncture resistance on the inner side of the tire's axial direction.

[0066] (3) A pneumatic tire as described in (1) or (2), wherein the bonding suppression portion 75 is a region on the sound-absorbing layer 70 to which a mold release agent is partially applied.

[0067] This makes it easy to form the bonding suppression portion 75.

[0068] (4) A pneumatic tire according to any one of (1) to (3), wherein the sealant layer 60 is made of a silicone-based material and the bonding suppression portion 75 is made of a non-silicone-based material.

[0069] As a result, when the sealant layer 60 is made of a silicone-based material, the bonding suppression part 75 can appropriately exert its effect of suppressing bonding between the sealant layer 60 and the sound-absorbing layer 70, thereby increasing the effect of suppressing the decrease in puncture resistance.

[0070] (5) A pneumatic tire according to any one of (1) to (4), wherein the sealant layer 60 has an inner opposing region 601a, which is a region in the tire axial direction that is inward of the sound-absorbing layer 70 than both ends of the sound-absorbing layer 70 in the tire axial direction in a tire axial cross-section, and an outer opposing region 601b, which is a region in the tire axial direction that is outward of the inner opposing region 601a than inward of the sound-absorbing layer 70 in a tire axial cross-section, and inward of the sound-absorbing layer 70 than both ends, and the width in the tire axial direction of the outer opposing region 601b that faces the sound-absorbing layer 70 at both ends is 10% or more and 30% or less of the width of the sound-absorbing layer 70 in the tire axial direction.

[0071] This makes it possible to enhance the effect of suppressing the decrease in puncture resistance while ensuring the stability of the sound-absorbing layer 70 in place.

[0072] (6) A pneumatic tire according to any one of (1) to (5), wherein the sealant layer 60 has an inner opposing region 601a, which is a region in the tire axial direction that is inward of the ends of the sound-absorbing layer 70 in the tire axial direction in a tire axial cross-section, and an outer opposing region 601b, which is a region in the tire axial direction that is outward of the inner opposing region 601a in a tire axial cross-section, and inward of the ends of the sound-absorbing layer 70 in the tire axial direction, and the width in the tire axial direction of the outer opposing region 601b that faces the sound-absorbing layer 70 at both ends is 10 mm or more and 20 mm or less, respectively.

[0073] This makes it possible to enhance the effect of suppressing the decrease in puncture resistance while ensuring the stability of the sound-absorbing layer 70 in place.

[0074] (7) A pneumatic tire according to any one of (1) to (6), wherein the contact surface 331 of the tread 30 has at least one main groove 341 that extends continuously along the circumferential direction of the tire, and the sealant layer 60 is positioned to be outward in the tire axial direction from all of the main grooves 341.

[0075] This ensures that the sealant layer 60 is placed on the inner side of all main grooves 341, increasing the likelihood of achieving puncture resistance.

[0076] (8) A pneumatic tire according to any one of (1) to (7), wherein the tread 30 is provided with a belt 31 disposed on the outer circumference side of the carcass ply 40, and the sealant layer 60 is disposed to a position that is outward in the tire axial direction from the belt 31.

[0077] This allows the sealant layer 60 to cover almost the entire area of ​​the tire cavity where there is a high risk of foreign objects puncturing it, thereby increasing the likelihood of achieving puncture resistance.

[0078] (9) A pneumatic tire according to any one of (1) to (8), wherein the sealant layer 60 has an inner opposing region 601a, which is a region in the tire axial direction that is inward of the sound-absorbing layer 70 than both ends of the sound-absorbing layer 70 in the tire axial direction in a tire axial cross section, and an outer opposing region 601b, which is a region in the tire axial direction that is outward of the inner opposing region 601a than inward of the sound-absorbing layer 70 in a tire axial cross section, and inward of the sound-absorbing layer 70 than both ends of the sound-absorbing layer 70 in a tire axial cross section, and the sealant layer 60 has non-opposing regions 601c, which are each located outward of the outer opposing region 601b in the tire axial direction and do not oppose the sound-absorbing layer 70, and the width of the non-opposing region 601c in the tire axial direction is wider than the width of the outer opposing region 601b in the tire axial direction.

[0079] This increases the likelihood that the sealant layer 60 will not have its deformation suppressed by the sound-absorbing layer 70 over a wider area, thereby allowing it to exhibit puncture resistance.

[0080] A method for manufacturing a pneumatic tire according to any one of (1) to (9), comprising the steps of: applying a material that partially constitutes the bonding suppression portion 75 to the side of the sound-absorbing layer 70 facing the sealant layer 60; and placing the sound-absorbing layer 70 on top of the sealant material such that the bonding suppression portion 75 of the sound-absorbing layer 70 faces the sealant material applied to the inner surface of the inner liner 50 on the inner cavity side of the tire.

[0081] This makes it possible to easily manufacture a pneumatic tire that has a bonding suppression portion 75, in which the deformation of the sealant layer 60 in the inner opposing region 601a is not inhibited by the sound-absorbing layer 70, and the reduction in puncture resistance is suppressed.

[0082] (Transformed form) The embodiments described above are not limited to those described above, and various modifications and changes are possible, which are also within the scope of this disclosure.

[0083] (Modified form 1) In this embodiment, the bonding suppression portion 75 was described as being formed by applying a release agent to the sound-absorbing layer 70. However, the invention is not limited to this, and for example, the bonding suppression portion may be constructed by placing a film-like or sheet-like material that can suppress the bonding between the sealant layer and the sound-absorbing layer between the sealant layer and the sound-absorbing layer.

[0084] (Modified form 2) In the embodiment described, the sealant layer 60 was shown to have a non-facing region 601c. However, the sealant layer may not have a region corresponding to the non-facing region and may face the sound-absorbing layer 70 over its entire surface.

[0085] While each embodiment and its variations can be used in combination as appropriate, a detailed explanation is omitted. Furthermore, this disclosure is not limited to the embodiments described above. [Explanation of symbols]

[0086] 1 tire 10 beads 11 Bead core 12 Bead Fillers 13 Cheha 14 Rim strip rubber 20 Sidewall 21 Sidewall rubber 30 tread 31 belt 32 Cap Ply 33 Tread Rubber 34 Tread Pattern 40 Carcass Ply 50 Inner Liner 60 sealant layer 70 Sound-absorbing layer 71 End 75 Joint suppression part 311 Belt 312 belt 331 Ground plane 341 Main groove 401 Main body 402 Bending section 403 Fold-over section 501 Inner self 601 Inner self 601a Medial facing area 601b Outer facing area 601c Non-opposed area

Claims

1. A pair of beads, A pair of sidewalls extending radially outward from each of the pair of beads, A tread having a contact surface is positioned between the pair of sidewalls, A carcass ply is stretched between the pair of beads, The inner liner is positioned on the inner side of the tire cavity of the carcass ply, A sealant layer is disposed on the inner surface of the inner liner on the inner side of the tire cavity, The sealant layer comprises a sound-absorbing layer disposed on the inner side of the tire cavity, A pneumatic tire wherein the sound-absorbing layer has a bonding-restricting portion on the side facing the sealant layer, which is used to suppress bonding with the sealant layer.

2. In the pneumatic tire described in claim 1, The bonding suppression portion is provided in a region inside the sound-absorbing layer, in a cross-section of the tire in the axial direction, rather than at both ends of the sound-absorbing layer in the axial direction of the tire, in a pneumatic tire.

3. In the pneumatic tire according to claim 1 or claim 2, The bonding suppression portion is a region on the sound-absorbing layer to which a release agent is partially applied, in a pneumatic tire.

4. In the pneumatic tire according to claim 1 or claim 2, The sealant layer is composed of a silicone-based material. The aforementioned bonding suppression portion is made of a non-silicone material, in a pneumatic tire.

5. In the pneumatic tire according to claim 1 or claim 2, The sealant layer is The region where the sealant layer and the sound-absorbing layer face each other via the bonding suppression portion, the inner opposing region being the region in the tire axial direction inward from both ends of the sound-absorbing layer in the tire axial direction in the tire axial cross-section, The region where the sealant layer and the sound-absorbing layer face each other is an outer opposing region which, in a cross-section of the tire axis, is located further outward in the tire axis direction than the inner opposing region and further inward in the tire axis direction than both ends of the sound-absorbing layer, It has, A pneumatic tire in which the width in the tire axial direction of the outer opposing regions facing each other at both ends of the sound-absorbing layer is 10% or more and 30% or less of the width in the tire axial direction of the sound-absorbing layer.

6. In the pneumatic tire according to claim 1 or claim 2, The sealant layer is The region where the sealant layer and the sound-absorbing layer face each other via the bonding suppression portion, the inner opposing region being the region in the tire axial direction inward from both ends of the sound-absorbing layer in the tire axial direction in the tire axial cross-section, The region where the sealant layer and the sound-absorbing layer face each other is an outer opposing region which, in a cross-section of the tire axis, is located further outward in the tire axis direction than the inner opposing region and further inward in the tire axis direction than both ends of the sound-absorbing layer, It has, A pneumatic tire in which the width in the tire axial direction of the outer opposing regions facing each other at both ends of the sound-absorbing layer is 10 mm or more and 20 mm or less, respectively.

7. In the pneumatic tire according to claim 1 or claim 2, The contact surface of the tread has at least one main groove that extends continuously along the circumferential direction of the tire. A pneumatic tire in which the sealant layer is positioned to be outward in the tire axial direction from all of the main grooves.

8. In the pneumatic tire according to claim 1 or claim 2, The tread comprises a belt disposed on the outer circumference side of the carcass ply, A pneumatic tire in which the sealant layer is positioned to be outward from the belt in the tire axial direction.

9. In the pneumatic tire according to claim 1 or claim 2, The sealant layer is The region where the sealant layer and the sound-absorbing layer face each other via the bonding suppression portion, the inner opposing region being the region in the tire axial direction inward from both ends of the sound-absorbing layer in the tire axial direction in the tire axial cross-section, The region where the sealant layer and the sound-absorbing layer face each other is an outer opposing region which, in a cross-section of the tire axis, is located further outward in the tire axis direction than the inner opposing region and further inward in the tire axis direction than both ends of the sound-absorbing layer, It has, The sealant layer is positioned further outward in the tire axial direction than the outer opposing region and has non-opposing regions that do not face the sound-absorbing layer. A pneumatic tire in which the width in the axial direction of the non-opposing region is wider than the width in the axial direction of the outer opposing region.

10. A method for manufacturing a pneumatic tire according to claim 1 or claim 2, The steps include applying a material that partially constitutes the bonding suppression portion to the side of the sound-absorbing layer facing the sealant layer, A method for manufacturing a pneumatic tire, comprising the steps of: placing the sound-absorbing layer on top of the sealant material such that the bonding suppression portion of the sound-absorbing layer faces the sealant material applied to the inner surface of the inner liner on the inner side of the tire cavity;

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