JP6707982B2 - Tire deterioration determination device and pneumatic tire including the same - Google Patents

Description

The present invention relates to a tire deterioration determination device and a pneumatic tire provided with the determination rubber layer, which is provided for a deterioration level determination test, on a tire inner surface, and more specifically, foreign matter adheres to the determination rubber layer. The present invention relates to a tire deterioration determination device that can be easily peeled from an inner surface of a tire in a non-operating state, and a pneumatic tire including the device.

In recent years, from the viewpoint of effective use of resources and energy saving, a retreaded tire obtained by recycling the pneumatic tire after the tread portion of the pneumatic tire has been worn out and is unusable has become popular. In particular, retreaded tires are widely used as heavy-duty pneumatic tires used for trucks and buses.

When a used pneumatic tire is rehabilitated, a base tire in which a tread rubber is ground is produced, and the base tire is covered with a new tread rubber. When performing such rehabilitation work, in order to confirm the remaining durability of the base tire, it is performed to confirm the presence or absence of internal separation by shearography inspection and the presence or absence of external damage by appearance inspection. ing. However, such an inspection cannot fully evaluate the degree of deterioration of the rubber composition that constitutes the pneumatic tire.

On the other hand, a tire deterioration determination tool in which a core rubber made of a sulfur-crosslinkable diene rubber composition is covered with a cover rubber having an oxygen permeability coefficient equal to or higher than that of the inner liner layer of the tire is provided on the tire inner surface. It has been proposed to install and determine the degree of deterioration of a pneumatic tire based on the result of a bending test of the tire deterioration determining tool (for example, see Patent Document 1). In this case, the tire deterioration judging tool is adhered to the inner surface of the tire in advance, and is peeled off when judging the tire deterioration.

However, when such a tire deterioration determination tool is firmly adhered to the tire inner surface with an adhesive, there is a problem that it is difficult to peel off the tire deterioration determination tool from the tire inner surface. Moreover, when the tire deterioration determining tool is peeled off from the inner surface of the tire, foreign matter such as adhesive is attached to the tire deterioration determining tool when determining the degree of deterioration of the pneumatic tire using the tire deterioration determining tool. It is necessary to remove the foreign matter from the tire deterioration determining tool, and the removing work is extremely complicated. Further, when the tire deterioration determining tool is greatly distorted during the peeling work, it may be a factor of lowering the determination accuracy when determining the deterioration degree of the pneumatic tire using the tire deterioration determining tool.

JP, 2006-327469, A

An object of the present invention is to configure a tire deterioration determination device in which a determination rubber layer used for a deterioration degree determination test is mounted on a tire inner surface, and the determination rubber layer is easily attached from the tire inner surface in a state where no foreign matter is attached. It is intended to provide a tire deterioration determination device that can be peeled off and a pneumatic tire including the same.

The tire deterioration determination device of the present invention for achieving the above object is constituted by a determination rubber layer made of a rubber composition and an adhesive layer laminated on the determination rubber layer, and the determination rubber layer is the adhesive layer. Is attached to the tire inner surface through the, the contact area between the tire inner surface and the adhesive layer is larger than the contact area between the adhesive layer and the determination rubber layer, characterized in that. ..

Further, the pneumatic tire of the present invention for achieving the above object is provided with a tire deterioration determination device including a determination rubber layer made of a rubber composition and an adhesive layer laminated on the determination rubber layer. In a pneumatic tire, the judgment rubber layer is attached to the tire inner surface via the pressure-sensitive adhesive layer, and the contact area between the tire inner surface and the pressure-sensitive adhesive layer is the pressure-sensitive adhesive layer and the judgment rubber layer. It is characterized in that it is larger than the contact area between them.

In the present invention, a tire deterioration determination device is composed of a determination rubber layer made of a rubber composition and an adhesive layer laminated on the determination rubber layer, and the determination rubber layer is attached to the tire inner surface by the adhesive layer. The determination rubber layer can be easily peeled off from the inner surface of the tire when determining the tire deterioration. Moreover, by making the contact area between the tire inner surface and the adhesive layer larger than the contact area between the adhesive layer and the determination rubber layer, the adhesive layer and the determination rubber layer rather than the interface between the tire inner surface and the adhesive layer. Peeling occurs preferentially at the interface of, so that the judgment rubber layer can be collected in a state where no foreign matter made of the adhesive layer adheres. Therefore, it is not necessary to remove foreign matter from the determination rubber layer when determining the degree of deterioration of the pneumatic tire using the determination rubber layer. Further, since the judgment rubber layer is peeled off without difficulty, the strain applied to the judgment rubber layer during the peeling work is suppressed, and the judgment accuracy when judging the deterioration degree of the pneumatic tire using the judgment rubber layer is improved. It is also possible to do so.

In the present invention, the average peeling force when removing the judgment rubber layer from the inner surface of the tire is preferably 2.0 N/inch to 100 N/inch. This allows the judgment rubber layer to be firmly held on the inner surface of the tire when the tire is running, while the judgment rubber layer can be easily peeled off from the inner surface of the tire when the tire deterioration is judged.

The elastic modulus of the adhesive layer is smaller than the elastic modulus of the member forming the inner surface of the tire, and the thickness of the adhesive layer is preferably 0.01 mm to 3.0 mm. By making the elastic modulus of the adhesive layer smaller than the elastic modulus of the member forming the tire inner surface, the adhesive layer can sufficiently follow the strain generated on the tire inner surface during tire running. Then, by sufficiently securing the thickness of the adhesive layer, it is possible to prevent the determination rubber layer from peeling from the tire inner surface due to the influence of strain generated on the tire inner surface during tire running. Further, by defining the upper limit of the thickness of the adhesive layer, it is possible to suppress the mass imbalance on the tire circumference due to the adhesive layer.

At the interface between the judgment rubber layer and the adhesive layer, there are non-adhesive areas where both do not directly contact with each other and adhesive areas where both directly contact with each other, and at least one of these non-adhesive area and adhesive area is divided into a plurality by the other. Preferably. In this way, by providing the non-adhesive region and the adhesive region at the interface between the judgment rubber layer and the adhesive layer and dividing at least one of the non-adhesive region and the adhesive region into a plurality by the other, sufficient adhesiveness based on the adhesive layer is obtained. It is possible to easily peel off the judgment rubber layer while maintaining the above.

Further, it is preferable that a release material is interposed at least at a part of the interface between the judgment rubber layer and the adhesive layer. Accordingly, a non-adhesive region can be formed on the interface between the determination rubber layer and the adhesive layer based on the release material, and the determination rubber layer can be easily peeled off.

The peeling force between the adhesive layer and the release material is preferably larger than the peeling force between the release material and the judgment rubber layer. More specifically, the release material has a laminated structure including a plurality of layers having different releasability, and the layer having the lowest releasability contacts the adhesive layer while the layer having the highest releasability is the judgment rubber. It is preferable that a release material is disposed between the determination rubber layer and the adhesive layer so as to contact the layer. If a release material is present at the interface between the judgment rubber layer and the adhesive layer, the release material may adhere to the judgment rubber layer when the judgment rubber layer is peeled off. When the peeling force is made larger than the peeling force between the release material and the judgment rubber layer, it is possible to prevent the release material from adhering to the judgment rubber layer.

In the present invention, the average peeling force is measured in accordance with the measuring method of "90° peeling adhesive force" described in JIS-Z0237 "Test method for adhesive tape/adhesive sheet". This average peeling force is measured by pulling the end portion of the judgment rubber layer while grasping the end portion. The elastic modulus is the elastic modulus (MPa) measured according to JIS-K7161:1994.

1 is a meridional sectional view showing a pneumatic tire for heavy load according to an embodiment of the present invention. It is a perspective view showing an example of a tire deterioration judging device concerning the present invention. It is a side view showing an example of a tire deterioration judging device concerning the present invention. It is a side view which shows the state which has begun to peel off the judgment rubber layer in the tire deterioration determination apparatus of FIG. It is a side view which shows the modification of the tire deterioration determination apparatus which concerns on this invention. It is a side view which shows the other modification of the tire deterioration determination apparatus which concerns on this invention. It is a side view which shows the further another modification of the tire deterioration determination apparatus which concerns on this invention. (A)-(b) is a top view which shows another modification of the tire deterioration determination apparatus which concerns on this invention, respectively. FIG. 3 is a side view showing an example of a release material used in the tire deterioration determination device according to the present invention. It is a side view which shows the modification of the mold release material used for the tire deterioration determination apparatus which concerns on this invention.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a pneumatic tire for heavy load according to an embodiment of the present invention, and FIGS. 2 to 4 show a tire deterioration determining device according to the present invention.

As shown in FIG. 1, the pneumatic tire of the present embodiment has a tread portion 1 extending in the tire circumferential direction and forming an annular shape, and a pair of sidewall portions 2 and 2 arranged on both sides of the tread portion 1. And a pair of bead portions 3, 3 arranged inside the sidewall portions 2 in the tire radial direction.

A carcass layer 4 is mounted between the pair of bead portions 3 and 3. The carcass layer 4 includes a plurality of reinforcing cords extending in the tire radial direction, and is folded back from the tire inner side to the outer side around the bead core 5 arranged in each bead portion 3. A bead filler 6 made of a rubber composition having a triangular cross section is arranged on the outer periphery of the bead core 5.

On the other hand, a plurality of belt layers 7 are embedded on the outer peripheral side of the carcass layer 4 in the tread portion 1. These belt layers 7 include a plurality of reinforcing cords that are inclined with respect to the tire circumferential direction, and the reinforcing cords are arranged so as to intersect each other between the layers. In the belt layer 7, the inclination angle of the reinforcing cord with respect to the tire circumferential direction is set in the range of, for example, 10° to 60°. A steel cord is preferably used as the reinforcing cord of the belt layer 7.

In the pneumatic tire, as shown in FIGS. 1 to 3, a sheet-shaped determination rubber layer 11 is detachably attached to a tire inner surface S facing the tire air chamber via a sheet-shaped adhesive layer 12. ing. That is, the adhesive layer 12 holds the determination rubber layer 11 in a removable state based on its adhesiveness. The determination rubber layer 11 and the adhesive layer 12 constitute the tire deterioration determination device 10. It is desirable that the tire deterioration determination device 10 is arranged in the tread portion 1 or the bead portion 3 which is relatively small in deformation during traveling. The tire deterioration determination device 10 may be attached to the inner surface S of the tire before or after vulcanization of the pneumatic tire, or only the adhesive layer 11 may be attached before vulcanization. Usually, the tire deterioration determination device 10 including the determination rubber layer 11 and the adhesive layer 12 is attached to the tire inner surface S after vulcanization.

As the rubber composition forming the judgment rubber layer 11, for example, a sulfur-crosslinkable diene rubber composition can be used. As the diene rubber, natural rubber (NR), isoprene rubber (IR), epoxidized natural rubber, styrene-butadiene rubber (SBR), butadiene rubber (BR), nitrile rubber (NBR), hydrogenated NBR, hydrogenated SBR, etc. Can be mentioned. However, the rubber used for the judgment rubber layer 11 is not limited to the above-mentioned diene rubber, and the rubber includes sulfur, a vulcanization accelerator, an antioxidant, a filler such as carbon black, and a softening agent such as oil. Agents, resins, waxes, metal salts such as cobalt salts, and additives such as stearic acid and zinc white can be appropriately mixed. In particular, when judging the oxidative deterioration of the tire, a natural rubber-based rubber composition that easily causes oxidative deterioration is preferable, and one containing sulfur and further a metal salt is preferable.

As the adhesive layer 12, for example, a double-sided tape in which an adhesive is applied to both surfaces of a base material or a sheet made of an adhesive can be used. As the adhesive, it is particularly preferable to use an acrylic adhesive. The acrylic pressure-sensitive adhesive is a suitable pressure-sensitive adhesive because the pressure-sensitive adhesive strength does not significantly decrease even at high temperatures (for example, about 100° C.).

In the pneumatic tire, the contact area between the tire inner surface S and the adhesive layer 12 is set to be larger than the contact area between the adhesive layer 12 and the determination rubber layer 11. More specifically, while the tire inner surface S and the adhesive layer 12 are in contact with each other over the entire interface, at least one recess 13 is formed at the interface of the adhesive layer 12 with the determination rubber layer 11. Thus, the adhesive layer 12 is in a non-contact state with the determination rubber layer 11 in the portion corresponding to the recess 13.

In the pneumatic tire described above, the tire deterioration determination device 10 is configured by the determination rubber layer 11 made of the rubber composition and the adhesive layer 12 laminated on the determination rubber layer 11, and the determination rubber layer 11 is the adhesive layer 12. Since it is attached to the tire inner surface S by pulling the end portion of the determination rubber layer 11 as shown in FIG. 4, the determination rubber layer 11 can be easily peeled from the tire inner surface S when the tire deterioration is determined. .. Moreover, by making the contact area between the tire inner surface S and the adhesive layer 12 larger than the contact area between the adhesive layer 12 and the determination rubber layer 11, the adhesive surface is more adhesive than the interface between the tire inner surface S and the adhesive layer 12. Peeling occurs preferentially at the interface between the layer 12 and the judgment rubber layer 11, so that the judgment rubber layer 11 can be collected in a state in which no foreign matter composed of the adhesive layer 12 is attached. Therefore, when determining the degree of deterioration of the pneumatic tire using the determination rubber layer 11, it is not necessary to remove foreign matter from the determination rubber layer 11. Further, since the judgment rubber layer 11 is peeled off without difficulty, it is possible to suppress the strain applied to the judgment rubber layer 11 during the peeling work. As a result, there is also an advantage that it is possible to improve the determination accuracy when determining the degree of deterioration of the pneumatic tire using the determination rubber layer 11.

In the above pneumatic tire, when the contact area between the tire inner surface S and the adhesive layer 12 is A1 and the contact area between the adhesive layer 12 and the determination rubber layer 11 is A2, 0.3×A1≦A2 It is preferable to satisfy the relationship of ≦0.7×A1 and more preferably the relationship of 0.4×A1≦A2≦0.6×A1. If the contact area A2 is less than 30% of the contact area A1, the judgment rubber layer 11 may separate from the adhesive layer 12 when the tire is running, and conversely if the contact area A2 is greater than 70% of the contact area A1, The effect of causing peeling preferentially at the interface with the judgment rubber layer 11 is reduced, and the adhesive layer 12 may partially adhere to the judgment rubber layer 11 when the judgment rubber layer 11 is peeled off.

In the pneumatic tire, the average peeling force when removing the judgment rubber layer 11 from the tire inner surface S is 2.0 N/inch to 100 N/inch, more preferably 10 N/inch to 50 N/inch, and further preferably 20 N. /Inch to 40 N/inch is preferable. Thereby, the judgment rubber layer 11 can be firmly held on the tire inner surface S when the tire is running, while the judgment rubber layer 11 can be easily peeled off from the tire inner surface S when the tire deterioration is judged. If the average peeling force of the judgment rubber layer 11 is less than 2.0 N/inch, the judgment rubber layer 11 may be separated from the tire inner surface S when the tire is running, and conversely, if it exceeds 100 N/inch, the judgment rubber layer 11 may be separated. It becomes difficult to peel off 11.

In the pneumatic tire, the elastic modulus of the adhesive layer 12 is smaller than the elastic modulus of the member forming the tire inner surface S, and the thickness t (see FIG. 3) of the adhesive layer 12 is 0.01 mm to 3.0 mm, more preferably Is 0.03 mm to 2.0 mm, and more preferably 0.03 mm to 1.0 mm. By making the elastic modulus of the pressure-sensitive adhesive layer 12 smaller than the elastic modulus of the member forming the tire inner surface S (for example, the inner liner layer), the pressure-sensitive adhesive layer 12 is sufficiently resistant to the strain generated on the tire inner surface S during tire running. You can follow. If the thickness t of the adhesive layer 12 is less than 0.01 mm, the determination rubber layer 11 may be peeled off from the tire inner surface S due to the strain generated on the tire inner surface S during tire running, and conversely 3.0 mm. If it exceeds, the mass balance on the tire circumference due to the adhesive layer 12 will be deteriorated. When the elastic modulus of the adhesive layer 12 is E1 and the elastic modulus of the member forming the tire inner surface S is E2, the ratio E1/E2 is preferably 0.001 to 0.7, for example.

FIG. 5 shows a modification of the tire deterioration determination device according to the present invention. In FIG. 5, a rugged portion 14A including a concave portion and/or a convex portion is formed on the tire inner surface S, and another undulated portion 14B matching the undulated portion 14A is formed at the interface of the adhesive layer 12 with the tire inner surface S. Has been formed. By adopting a structure in which the undulations 14A and the other undulations 14B mesh with each other at the interface between the tire inner surface S and the adhesive layer 12 as described above, the contact area between the tire inner surface S and the adhesive layer 12 is It is set to be larger than the contact area between 12 and the judgment rubber layer 11. In this case, when the judgment rubber layer 11 is peeled off, peeling occurs preferentially at the interface between the adhesive layer 12 and the judgment rubber layer 11 rather than at the interface between the tire inner surface S and the adhesion layer 12.

FIG. 6 shows another modification of the tire deterioration determination device according to the present invention. In FIG. 6, the release material 15 is interposed at least at a part of the interface between the determination rubber layer 11 and the adhesive layer 12. As a result, the non-adhesive region X1 is formed on the interface between the determination rubber layer 11 and the adhesive layer 12 based on the release material 15, so that the determination rubber layer 11 can be easily peeled off.

7 and 8(a)-(b) show still another modified example of the tire deterioration determination device according to the present invention. In FIG. 7, a plurality of release materials 15 are interposed at the interface between the judgment rubber layer 11 and the adhesive layer 12. These release materials 15 are arranged at intervals along the interface between the judgment rubber layer 11 and the adhesive layer 12. As a result, a non-adhesive region X1 in which the two are not in direct contact with each other and an adhesive region X2 in which both are in direct contact with each other are formed at the interface between the determination rubber layer 11 and the adhesive layer 12. In a plan view, as shown in FIGS. 8A and 8B, the non-adhesive region X1 in which the both are not in direct contact with each other is in direct contact with the interface between the judgment rubber layer 11 and the adhesive layer 12. An adhesive area X2 (hatched area) exists, and at least one of the non-adhesive area X1 and the adhesive area X2 is divided into a plurality by the other. As described above, the non-adhesive region X1 and the adhesive region X2 are provided at the interface between the determination rubber layer 11 and the adhesive layer 12, and at least one of the non-adhesive region X1 and the adhesive region X2 is divided into a plurality of parts by the other to form the adhesive layer. The determination rubber layer 11 can be easily peeled off while sufficiently maintaining the adhesiveness based on 12.

The release material 15 may have a single-layer structure of a release layer made of a silicone-based resin, a fluorine-based resin, a solvent, or the like. However, the structure of the release material 15 is not particularly limited, and various laminated structures can be adopted.

FIG. 9 shows an example of a release material used in the tire deterioration determination device according to the present invention. In FIG. The release material 15 is composed of a film-shaped base material layer 15A and release layers 15B and 15B adhered to both surfaces of the base material layer 15A. As the constituent material of the base material layer 15A, resin, paper, or the like can be used. On the other hand, as a constituent material of the release layer 15B, a silicone-based resin, a fluorine-based resin, or the like can be used.

FIG. 10 shows a modified example of the release material used in the tire deterioration determination device according to the present invention. In FIG. 10, the release material 15 is composed of a film-shaped base material layer 15A and a release layer 15B applied to one surface of the base material layer 15A. The release layer 15B has a higher releasability than the base material layer 15A. The release material 15 is disposed between the determination rubber layer 11 and the adhesive layer 12 so that the base material layer 15A contacts the adhesive layer 12 and the release layer 15B contacts the determination rubber layer 11. Thereby, the peeling force between the adhesive layer 12 and the release material 15 is larger than the peeling force between the release material 15 and the determination rubber layer 11. In this way, when the peeling force between the adhesive layer 12 and the release material 15 is made larger than the peeling force between the release material 15 and the judgment rubber layer 11, the release material is peeled off when the judgment rubber layer 11 is peeled off. It is possible to more reliably prevent 15 from adhering to the judgment rubber layer 11.

In the example of FIG. 10, the case where the mold release material 15 is composed of the base material layer 15A and the mold release layer 15B has been described, but a mold release material having a laminated structure including a plurality of layers having different mold releasability is configured. At this time, for example, it is also possible to laminate release layers on both sides of the base material layer and to make the constituent materials of these release layers different from each other.

Hereinafter, a tire deterioration determination method using the tire deterioration determination device 10 described above will be briefly described. First, in a pneumatic tire, the determination rubber layer 11 of the tire deterioration determination device 10 is detachably attached to the tire inner surface S by the adhesive layer 12. The tire deterioration determination device 10 may be mounted immediately after the pneumatic tire is manufactured, or may be mounted at the start of use of the pneumatic tire. The judgment rubber layer 11 of the tire deterioration judgment device 10 is one in which the physical characteristics of a new product are known in advance. Then, the judgment rubber layer 11 attached to the tire inner surface S is removed at an arbitrary time after the start of use of the tire. For example, the determination rubber layer 11 is removed from the tire inner surface S at the time when the vehicle travels an arbitrary mileage during the tire use process, when performing rehabilitation work, or when discarding the tire. Then, the physical properties of the determination rubber layer 11 are measured, the amount of change in the physical properties from the time of new product is obtained using the measured value, and the degree of deterioration of the pneumatic tire is determined based on the amount of change.

Examples of physical properties include weight (specific gravity), oxygen adsorption amount, electric resistance, hardness, rupture property, viscoelastic property, and the like. When the judgment rubber layer 11 deteriorates due to oxidation, the weight (specific gravity), the amount of oxygen adsorbed, the electric resistance, the hardness, the breaking property, and the viscoelastic property change with the deterioration. The degree of deterioration of the pneumatic tire can be accurately determined based on the above. It is also possible to chemically analyze the judgment rubber layer 11 and use the analysis result as an index of the degree of deterioration.

A tire deterioration determination device including a determination rubber layer made of a rubber composition and an adhesive layer laminated on the determination rubber layer is prepared, and each of the tire deterioration determination devices is a pneumatic tire having a tire size of 11R22.5. It was attached to the inner surface of (No. 1 of Comparative Example and Examples 1 to 6). The tire deterioration determination device was mounted on the inner surface of the tire at the tire equator position.

In Comparative Example 1 and Examples 1 to 6, by interposing a release material at the interface between the judgment rubber layer and the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer and the pressure-sensitive adhesive rubber layer with respect to the contact area between the inner surface of the tire and the pressure-sensitive adhesive layer. The contact area ratio (contact area ratio of the pressure-sensitive adhesive layer) was varied as shown in Table 1. Further, the average peeling force when removing the judgment rubber layer from the tire inner surface and the thickness of the adhesive layer were set as shown in Table 1. An acrylic adhesive was used as the adhesive of the adhesive layer. The elastic modulus of this adhesive layer is smaller than the elastic modulus of the inner liner layer forming the inner surface of the tire.

On the other hand, a tire deterioration determination device of the type in which the determination rubber layer is adhered to the tire inner surface with an adhesive was prepared, and the tire deterioration determination device was attached to the tire inner surface (conventional example). A chloroprene rubber adhesive was used as the adhesive.

With respect to the pneumatic tires equipped with the tire deterioration determination devices of the conventional example, the comparative example 1 and the examples 1 to 6 described above, the retaining property and the peeling easiness of the determination rubber layer were evaluated by the following methods, and the results were obtained. The results are also shown in Table 1.

Judgment rubber layer retention:
Each test tire was mounted on a wheel with a rim size of 22.5 x 7.50 and mounted on a drum tester equipped with a drum with a diameter of 1707 mm, and a running test of 20000 km was carried out under the conditions of an air pressure of 700 kPa, a load of 37 kN and a speed of 45 km/h. After running, the holding state of the judgment rubber layer was examined. The evaluation results are shown by "A" when the judgment rubber layer is firmly held on the tire inner surface, and by "B" when the judgment rubber layer is held on the tire inner surface but is unstable. The case where the judgment rubber layer is separated from the inner surface of the tire is indicated by "C".

Ease of peeling the judgment rubber layer:
The judgment rubber layer was peeled from the inner surface of each test tire, and the ease of peeling at that time was evaluated. The evaluation results are shown by "A" when the judgment rubber layer could be easily peeled off without any foreign matter adhering, and when the judgment rubber layer was peeled off, the judgment rubber layer had a foreign substance composed of an adhesive layer. The case where they are attached is shown by "B", and the case where the judgment rubber layer is deformed or damaged by peeling is shown by "C".

As is clear from Table 1, in the tires of Examples 1 to 6, the judgment rubber layer could be easily peeled off from the tire inner surface, and the judgment rubber layer could be collected in a good state. Further, in the tires of Examples 1 to 6, the retaining property of the judgment rubber layer was also good. On the other hand, in the conventional tire, although the retaining property of the determination rubber layer was good, it was difficult to peel off the determination rubber layer, and the peeled determination rubber layer was largely deformed. In addition, in the tire of Comparative Example 1, the operation of peeling off the judgment rubber layer was rather difficult, and foreign matter composed of an adhesive layer adhered to the peeled judgment rubber layer.

1 Tread Part 2 Sidewall Part 3 Bead Part 4 Carcass Layer 5 Bead Core 6 Bead Filler 7 Belt Layer 10 Tire Deterioration Judgment Device 11 Judgment Rubber Layer 12 Adhesive Layer 13 Recesses 14A, 14B Undulating Part 15 Release Agent 15A Base Material Layer 15B Release Mold Layer S Tire inner surface

Claims (14)

It is composed of a judgment rubber layer made of a rubber composition and an adhesive layer laminated to the judgment rubber layer, the judgment rubber layer is attached to the tire inner surface via the adhesion layer, and the tire inner surface and the tire A tire deterioration determination device, wherein a contact area between the adhesive layer and the adhesive layer is larger than a contact area between the adhesive layer and the determination rubber layer. The tire deterioration determination device according to claim 1, wherein an average peeling force when removing the determination rubber layer from the inner surface of the tire is 2.0 N/inch to 100 N/inch. The elastic modulus of the adhesive layer is smaller than the elastic modulus of a member forming the tire inner surface, and the thickness of the adhesive layer is 0.01 mm to 3.0 mm. Tire deterioration determination device. At the interface between the judgment rubber layer and the adhesive layer, there are non-adhesive areas where both do not directly contact each other and adhesive areas where both directly contact each other, and at least one of these non-adhesive area and adhesive area is divided into a plurality by the other. The tire deterioration determination device according to claim 1, wherein the tire deterioration determination device is provided. The tire deterioration determination device according to claim 1, wherein a release material is interposed at least at a part of an interface between the determination rubber layer and the adhesive layer. The tire deterioration determination device according to claim 5, wherein a peeling force between the adhesive layer and the release material is larger than a peeling force between the release material and the determination rubber layer. The release material has a laminated structure including a plurality of layers having different releasability, and the layer having the lowest releasability contacts the adhesive layer while the layer having the highest releasability contacts the judgment rubber layer. The tire deterioration determination device according to claim 6, wherein the release material is disposed between the determination rubber layer and the adhesive layer so as to be in contact with each other. A pneumatic tire equipped with a tire deterioration determination device composed of a determination rubber layer made of a rubber composition and an adhesive layer laminated to the determination rubber layer, wherein the determination rubber layer is provided via the adhesive layer. And a contact area between the tire inner surface and the adhesive layer is larger than a contact area between the adhesive layer and the determination rubber layer. The pneumatic tire according to claim 8, wherein an average peeling force when removing the determination rubber layer from the inner surface of the tire is 2.0 N/inch to 100 N/inch. The elastic modulus of the adhesive layer is smaller than the elastic modulus of a member forming the tire inner surface, and the thickness of the adhesive layer is 0.01 mm to 3.0 mm. Pneumatic tires. At the interface between the judgment rubber layer and the adhesive layer, there are non-adhesive areas where both do not directly contact each other and adhesive areas where both directly contact each other, and at least one of these non-adhesive area and adhesive area is divided into a plurality by the other. The pneumatic tire according to any one of claims 8 to 10, wherein the pneumatic tire is a tire. The pneumatic tire according to any one of claims 8 to 11, wherein a release material is interposed at least at a part of an interface between the judgment rubber layer and the adhesive layer. The pneumatic tire according to claim 12, wherein a peeling force between the adhesive layer and the release material is larger than a peeling force between the release material and the determination rubber layer. The release material has a laminated structure including a plurality of layers having different releasability, and the layer having the lowest releasability contacts the adhesive layer while the layer having the highest releasability contacts the judgment rubber layer. The pneumatic tire according to claim 13, wherein the release material is disposed between the determination rubber layer and the adhesive layer so as to be in contact with each other.

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