Sealing sheet for pneumatic tire

Abstract

One aspect of the present invention provides a sealing sheet for a pneumatic tire, comprising at least a sealing material layer to be adhered to the inner surface of a pneumatic tire, wherein when the thickness of the sealing material layer is defined as T [mm] and the storage modulus of the sealing material layer at 60°C is defined as E [kPa], T and E satisfy the following relationship: [(1000×T) / E]<50. Another aspect of the present invention provides a sealing sheet for a pneumatic tire, comprising at least a sealing material layer to be adhered to the inner surface of a pneumatic tire, wherein the storage modulus of the sealing material layer at -5°C is less than 500 kPa and the storage modulus at 60°C is greater than 10 kPa. Another aspect of the present invention provides a sealing sheet for a pneumatic tire, which includes at least a sealing material layer to be adhered to the inner surface of the pneumatic tire, wherein the storage modulus of the sealing material layer at 23°C is less than 350 kPa, the storage modulus of the sealing material layer at 60°C after 30 days at 100°C is more than 10 kPa, and the maximum stress of the sealing material layer at 23°C is more than 1.0 N / 10 mm.

Description

[0001] Cross-reference of related applications

[0002] This application claims priority to Japanese Patent Application Nos. 2024-041343, 2024-041383 and 2024-041391, which are incorporated herein by reference. Technical Field

[0003] This invention relates to, for example, sealing sheets for pneumatic tires used to prevent pneumatic tire blowouts. Background Technology

[0004] Bicycles or motorcycles, for example, are equipped with pneumatic tires and travel on roads. When such a vehicle travels over a sharp object (such as a nail, a shard of glass, etc.) located on the road, part of the object may puncture the pneumatic tire, causing air to leak out and potentially causing a tire blowout.

[0005] To address this, compositions for forming a sealing material layer by being applied to the inner surface of a pneumatic tire (e.g., Patent Document 1) are known to prevent tire blowouts. The composition described in Patent Document 1 is a curable liquid (liquid sealant) containing latex or the like. By applying the aforementioned liquid composition to the inner surface of the tire, a sealing material layer can be formed, which can suppress air leakage to some extent, thus preventing tire blowouts.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: U.S. Patent Application Publication No. 2003 / 0136490 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] However, the composition (liquid sealant) described in Patent Document 1 sometimes results in hands becoming contaminated with the liquid sealant during use, or accidental dripping of the liquid sealant, leading to poor workability. On the other hand, sealing sheets for pneumatic tires with a sheet-like, non-liquid sealing material layer are known. The sealing material layer adheres well to the inner surface of the tire, but sealing sheets for pneumatic tires with such a sealing material layer have not been sufficiently studied. Furthermore, sealing sheets for pneumatic tires with a sealing material layer that can be easily adhered to curved portions of the inner surface of the tire and can closely conform to the adhered curved portions have also not been sufficiently studied.

[0011] In addition, there is a need for a sealing sheet for pneumatic tires that can suppress the leakage of gas from inside the tire to the outside even if the thickness of the sealing material layer is relatively thin (hereinafter also referred to as good sealing performance), but such sealing sheets for pneumatic tires have not yet been sufficiently studied.

[0012] Therefore, one aspect of the present invention is to provide a sealing sheet for a pneumatic tire, which has a sealing material layer in sheet form, thus exhibiting good adhesion to the inner surface of the tire. The sealing material layer can be easily adhered to curved portions of the inner surface of the tire, can closely conform to the adhered curved portions, and provides good sealing even when the thickness is relatively thin.

[0013] On the other hand, there is a need for a sealing sheet for inflatable tires that, even when the sealing material layer is first applied to the inner surface of the tire, can prevent gas inside the tire from leaking out to the outside (hereinafter also referred to as having good sealing performance) when holes are made in the sealing material layer applied to the inner surface of the tire in low-temperature winter conditions or high-temperature summer conditions. However, such sealing sheets for inflatable tires have not yet been sufficiently studied.

[0014] Therefore, another aspect of the present invention is to provide a sealing sheet for a pneumatic tire, which has a sealing material layer in sheet form, thus exhibiting good adhesion to the inner surface of the tire. The sealing material layer can be easily adhered to curved portions of the inner surface of the tire, and can closely conform to the adhered curved portions. Furthermore, the sealing material layer exhibits good low-temperature sealing and high-temperature sealing properties.

[0015] Furthermore, on the other hand, sealing sheets for pneumatic tires that have a sealing material layer with openings in it, capable of preventing gas leakage from inside the tire to the outside (hereinafter also referred to as having good sealing performance), have not been sufficiently studied. In addition, for the purpose of tire reuse, there is a requirement for sealing sheets for pneumatic tires that have a sealing material layer that is easily peeled off when the sealing material layer adhered to the inner surface of the tire is removed (hereinafter also referred to as having good recyclability), but such sealing sheets for pneumatic tires have not yet been sufficiently studied.

[0016] Therefore, another aspect of the present invention is to provide a sealing sheet for a pneumatic tire, which has a sealing material layer in sheet form, thus exhibiting good adhesion to the inner surface of the tire. The sealing material layer can be easily adhered to curved portions of the inner surface of the tire, and can closely conform to the adhered curved portions. Furthermore, the sealing material layer exhibits both good sealing performance and good recyclability.

[0017] means for solving problems

[0018] To address the aforementioned issues, one aspect of the present invention provides a sealing sheet for a pneumatic tire that includes at least a layer of sealing material to be adhered to the inner surface of the pneumatic tire. When the thickness of the sealing material layer is set as T [mm] and the energy storage modulus of the sealing material layer at 60°C is set as E [kPa], T and E satisfy the following relationship.

[0019] [(1000×T) / E]<50

[0020] To address the aforementioned issues, another aspect of the present invention provides a sealing sheet for pneumatic tires that includes at least a layer of sealing material to be adhered to the inner surface of the pneumatic tire. The energy storage modulus of the sealing material layer is less than 500 kPa at -5°C and greater than 10 kPa at 60°C.

[0021] To address the aforementioned issues, another aspect of the present invention provides a sealing sheet for pneumatic tires that includes at least a layer of sealing material to be adhered to the inner surface of the pneumatic tire. The energy storage modulus of the sealing material layer at 23°C is below 350 kPa, and after 30 days at 100°C, the energy storage modulus of the sealing material layer at 60°C is above 10 kPa. The maximum stress of the sealing material layer at 23°C is greater than 1.0 N / 10 mm. Attached Figure Description

[0022] Figure 1A This is a schematic cross-sectional view of an example of the sealing sheet for an inflatable tire according to this embodiment, cut along the thickness direction.

[0023] Figure 1B This is a schematic cross-sectional view showing an example of a sealing material layer of a sealing sheet for an inflatable tire being adhered to an object.

[0024] Figure 1C This is a schematic cross-sectional view showing one specific example of the sealing material layer in this embodiment.

[0025] Figure 2A This is a schematic cross-sectional view showing another example of the sealing sheet for a pneumatic tire according to this embodiment cut along the thickness direction.

[0026] Figure 2B This is a schematic cross-sectional view showing the shape of a sealing material layer just after it has been adhered to the object, representing another example of a sealing sheet for an inflatable tire.

[0027] Figure 2C This is a schematic cross-sectional view showing the form in which a sealing material layer for a pneumatic tire sealant is adhered to an object.

[0028] Figure 3 This is a schematic diagram showing the state in which most of the sealing sheet for the pneumatic tire of this embodiment is wound up.

[0029] Figure 4 It is a rough diagram showing the wheels of a bicycle.

[0030] Figure 5 It is a schematic cross-sectional view showing a portion of the bicycle wheel cut off along a plane orthogonal to the circumference of the wheel. Figure 4 (VV-line sectional view).

[0031] Figure 6A This is a schematic cross-sectional view showing the shape of a nail piercing a layer of sealing material on a pneumatic tire with a sealing strip attached. Figure 5 Part A of the document.

[0032] Figure 6B This is a schematic cross-sectional view showing the shape of a pneumatic tire after the nail has been removed from the tire, where a layer of sealing material (such as a tire sealant) has been applied. Figure 5 Part A). Detailed Implementation

[0033] Hereinafter, embodiments of the sealing sheet for pneumatic tires of the present invention will be described with reference to the accompanying drawings. The first to third embodiments will be described, but parts common to each other in the first to third embodiments will not be described again. For parts where the configuration of any embodiment differs from that of the other embodiments, each embodiment will be described separately. It should be noted that the term "this embodiment" is sometimes used to refer to all of the first to third embodiments.

[0034] The pneumatic tire sealing sheet 1 of this embodiment includes at least a sheet-like sealing material layer 11. The pneumatic tire sealing sheet 1 (hereinafter also simply referred to as a tire sealing sheet) may also include a substrate layer 12 overlapping one side of the sealing material layer 11. When the pneumatic tire sealing sheet 1 of this embodiment also includes the aforementioned substrate layer 12, the component consisting of at least the sealing material layer 11 and the substrate layer 12 is also referred to as a substrate-layered tape 10.

[0035] The tire sealing sheet 1 of this embodiment may also have a release liner 20 on at least one side of the sealing material layer 11.

[0036] The tire sealing sheet 1 of this embodiment can be, for example, as follows: Figure 1AThe diagram shows an adhesive tape 10 with a substrate layer, comprising a sealing material layer 11 and a substrate layer 12, and a release liner 20 overlapping one side of the sealing material layer 11. The adhesive tape 10 is composed of at least the sealing material layer 11 and the substrate layer 12, for example, in a state where the sealing material layer 11 and the substrate layer 12 overlap each other. The adhesive tape 10 may be a portion from the tire sealant 1 with the release liner 20 removed.

[0037] On the other hand, the tire sealing sheet 1 of this embodiment can, for example, Figure 2A The device includes: a sealing material layer 11, and a release liner 20 overlapping on one side of the sealing material layer 11 or two release liners 20 overlapping on both sides of the sealing material layer 11.

[0038] The tire sealing sheet 1 in this embodiment is as follows: Figures 1A to 1C and Figures 2A to 2C The following method is used: Remove the release liner 20 and adhere either side of the sealant layer 11 to the object X. The sealant layer 11 has pressure-sensitive adhesive properties. The object X is an inflatable tire, etc., that will be installed on the wheel of a bicycle or motorcycle.

[0039] The thickness of the tire sealing sheet 1 in this embodiment is preferably 50 μm or more, more preferably 100 μm or more, even more preferably 150 μm or more, even more preferably 200 μm or more, and particularly preferably 500 μm or more.

[0040] The thickness of the tire sealing sheet 1 in this embodiment is preferably 2500 μm or less, more preferably 2000 μm or less, even more preferably 1500 μm or less, and particularly preferably 1000 μm or less.

[0041] In the tire seal 1 of the first embodiment, when the thickness of the sealing material layer 11 is set to T [mm] and the storage modulus of the sealing material layer 11 at 60°C is set to E [kPa], T and E satisfy the following relationship. In the tire seal 1 of the second and third embodiments, T and E can satisfy the following relationship.

[0042] [(1000×T) / E]<50

[0043] The sealing material layer 11 is sheet-like, thus providing good workability when applied to the inner surface of the tire. Furthermore, the sealing material layer 11 can be easily applied to curved portions of the tire's inner surface, conforming closely to the curved areas to which it is applied.

[0044] Therefore, even if the thickness of the sealing material layer 11 is relatively thin, the sealing material layer 11 can still have good sealing performance.

[0045] In the preferred embodiment of the tire sealant 1 described above, as described later, it has high transparency and good visual visibility, thus allowing for visual confirmation of temporary lifting or peeling after the sealing material layer 11 has been adhered to the substrate. Furthermore, in the preferred embodiment of the tire sealant 1 described above, even if the sealing material layer 11 is relatively thin, it can maintain a sufficiently coiled state. Additionally, in the preferred embodiment of the tire sealant 1 described above, as described later, it has good recyclability.

[0046] In the tire seal 1 of the second embodiment, the storage modulus of the sealing material layer 11 at -5°C is less than 500 kPa and the storage modulus at 60°C is greater than 10 kPa. In the tire seal 1 of the first and third embodiments, these storage moduli can respectively satisfy the above values.

[0047] The sealing material layer 11 is sheet-like, thus offering good workability when applied to the inner surface of the tire. Furthermore, the sealing material layer 11 can be easily applied to curved portions of the tire's inner surface, conforming closely to the curved areas. Therefore, even with a relatively thin layer, the sealing material layer 11 provides excellent sealing performance.

[0048] Furthermore, the sealing material layer 11 can prevent gas leakage from inside the tire to the outside in both low-temperature and high-temperature environments. That is, the sealing material layer 11 has good low-temperature sealing and high-temperature sealing properties.

[0049] In the preferred embodiment of the tire sealant 1 described above, as described later, it has high transparency and good visual visibility, thus allowing for visual confirmation of temporary lifting or peeling after the sealing material layer 11 has been adhered to the substrate. Furthermore, in the preferred embodiment of the tire sealant 1 described above, even if the sealing material layer 11 is relatively thin, it can maintain a sufficiently coiled state. Additionally, in the preferred embodiment of the tire sealant 1 described above, as described later, it has good recyclability.

[0050] In the tire seal 1 of the third embodiment, the storage modulus of the sealing material layer 11 at 23°C is 350 kPa or less, the storage modulus of the sealing material layer 11 at 60°C after 30 days at 100°C is 10 kPa or more, and the maximum stress of the sealing material layer 11 at 23°C is 1.0 N / 10 mm or more. In the tire seal 1 of the first and second embodiments, these storage modulus and maximum stress values ​​can respectively satisfy the above values.

[0051] The sealing material layer 11 is sheet-like, thus offering good workability when applied to the inner surface of the tire. Furthermore, the sealing material layer 11 can be easily applied to curved portions of the tire's inner surface, conforming closely to the curved areas. Therefore, even with a relatively thin layer, the sealing material layer 11 provides excellent sealing performance.

[0052] Furthermore, the sealing material layer 11 that is first attached to the tire can be peeled off relatively easily, making it suitable for tire recycling.

[0053] In the preferred embodiment of the tire sealant 1 described above, as described later, it has high transparency and good visual visibility, thus enabling visual confirmation of temporary lifting or peeling after the sealant layer 11 has been adhered to the substrate. Furthermore, in the preferred embodiment of the tire sealant 1 described above, even if the sealant layer 11 is relatively thin, it can be sufficiently maintained in a wound state.

[0054] (Sealing material layer)

[0055] The thickness of the sealing material layer 11 is preferably 50 μm or more, more preferably 100 μm or more, even more preferably 150 μm or more, and even more preferably 200 μm or more.

[0056] The thickness of the sealing material layer 11 is preferably 2000 μm or less, more preferably 1500 μm or less, even more preferably 1200 μm or less, even more preferably 1000 μm or less, and even more preferably 800 μm or less.

[0057] By ensuring the thickness of the sealing material layer 11 is within the aforementioned range, the tire sealant 1 exhibits excellent lightweight properties and improves its workability when applied to tires with highly curved surfaces, such as bicycle tires. Furthermore, when the tire sealant 1 has a release liner, it is easy to maintain a rolled shape (wound state), and the protrusion of the adhesive paste can also be suppressed.

[0058] The sealing material layer 11 can have a single-layer structure or a multi-layer structure formed by stacking multiple layers with different components.

[0059] In the tire seal 1 of this embodiment, the storage modulus of the sealing material layer 11 at 23°C is preferably 350 kPa or less, more preferably 100 kPa or less, and even more preferably 50 kPa or less. The storage modulus of the sealing material layer 11 at 23°C is preferably 10 kPa or more, more preferably 20 kPa or more, and even more preferably 30 kPa or more. Within the above numerical ranges, the sealing performance of the sealing material layer 11 at room temperature (its adhesion to the tire and its ability to fill a portion of the through-holes described later) is improved.

[0060] In the tire sealing sheet 1 of this embodiment, the storage modulus of the sealing material layer 11 at -5°C is preferably less than 500 kPa, more preferably less than 400 kPa, and even more preferably less than 200 kPa. The storage modulus of the sealing material layer 11 at -5°C is preferably 50 kPa or more, more preferably 100 kPa or more, and even more preferably 150 kPa or more. Within the above-mentioned numerical ranges, there is an advantage that the sealing performance of the sealing material layer 11 at low temperatures is improved.

[0061] In the tire sealing sheet 1 of this embodiment, the storage modulus of the sealing material layer 11 at 60°C is preferably 50 kPa or less, more preferably 40 kPa or less, and even more preferably 30 kPa or less. The storage modulus of the sealing material layer 11 at 60°C is preferably greater than 10 kPa, more preferably 15 kPa or more, and even more preferably 20 kPa or more. Within the above numerical ranges, there is an advantage that the sealing performance of the sealing material layer 11 at high temperatures becomes better.

[0062] In the tire sealing sheet 1 of the first embodiment, when the thickness of the sealing material layer 11 is set to T [mm] and the energy storage modulus of the sealing material layer 11 at 60°C is set to E [kPa], the T and the E satisfy the following relationship.

[0063] [(1000×T) / E]<50

[0064] In the tire sealing sheet 1 of this embodiment, the value on the left side of the above formula is preferably 45 or less, more preferably less than 45, further preferably 40 or less, and even more preferably 30 or less. The value on the left side of the following formula is preferably 0.1 or more, more preferably 1 or more, and even more preferably 5 or more. Within the above numerical ranges, the following advantages are achieved: the sealing material layer 11 can better conform to the curved portion of the inner surface of the tire, and the sealing performance of the sealing material layer 11 becomes better.

[0065] The ratio of the storage modulus of the sealing material layer 11 at -5°C to its storage modulus at 60°C is preferably 20 or less, more preferably 10 or less, and even more preferably 8 or less. This ratio is preferably 1 or more, more preferably 3 or more, and even more preferably 4 or more. Within the above numerical range, good sealing performance at both low and high temperatures can be achieved.

[0066] The storage modulus of the sealing material layer 11 at various specified temperatures can be increased, for example, by increasing the content of thermoplastic elastomer contained in the sealing material layer 11.

[0067] The storage modulus of the sealing material layer 11 at various specified temperatures refers to the storage modulus measured by a dynamic viscoelasticity measuring device. The measurement conditions are as follows.

[0068] [Measurement Conditions]

[0069] • Measuring apparatus: Dynamic viscoelasticity measuring apparatus

[0070] (For example, manufactured by TA Instruments, the device is named "ARES-G2")

[0071] • Test specimen: A circular plate with a diameter of 8 mm and a thickness of 1.0 mm (cut from the sealing material layer).

[0072] • Probe: 8mm in diameter

[0073] • Deformation mode: Sine wave

[0074] • Frequency: 1Hz

[0075] • Heating rate: 5℃ / min

[0076] • Measurement temperature: -60℃~150℃

[0077] By reading the values ​​of the energy storage modulus at -5℃, 23℃, or 60℃ from the obtained measurement data, the value of the energy storage modulus at each temperature can be calculated.

[0078] In the tire seal 1 of this embodiment, after the sealing material layer 11 is subjected to 100°C for 30 days, the storage modulus of the sealing material layer 11 at 60°C is preferably 5 kPa or more, more preferably 10 kPa or more, and even more preferably 20 kPa or more. This storage modulus is preferably 50 kPa or less, more preferably 40 kPa or less, and more preferably 30 kPa or less. Within the above-mentioned numerical range, the sealing performance of the sealing material layer 11 can be improved.

[0079] As mentioned above, the energy storage modulus of the sealing material layer 11 at 23°C after long-term placement in a high-temperature environment can be increased, for example, by increasing the content of thermoplastic elastomer contained in the sealing material layer 11.

[0080] The tensile modulus of the sealing material layer 11 at 23°C is preferably 0.30 MPa or less, more preferably 0.20 MPa or less, and even more preferably 0.15 MPa or less. The tensile modulus of the sealing material layer 11 at 23°C is preferably 0.01 MPa or more, more preferably 0.05 MPa or more, and even more preferably 0.10 MPa or more. Within the above-mentioned numerical ranges, the sealing performance of the sealing material layer 11 can be improved.

[0081] The tensile modulus of the sealing material layer 11 at 23°C can be reduced, for example, by decreasing the content of thermoplastic elastomer contained in the sealing material layer 11.

[0082] The tensile modulus of the sealing material layer 11 was calculated based on the results of the tensile test. The tensile test was conducted under the following conditions.

[0083] Test environment: 23℃±2℃, 50%RH±10%RH

[0084] Test piece shape: 10mm wide, 50mm long

[0085] Stretching speed: 300mm / minute

[0086] Distance between clamps: 10mm

[0087] The tensile modulus is determined by the slope of the stress-strain curve relative to strain at two specified points (the ratio of tensile stress to its corresponding strain within the tensile proportional limit). Specifically, the tensile modulus is calculated according to the following formula.

[0088] Tensile modulus (MPa) =

[0089] σ1: Tensile stress measured when strain ε1 = 0.10

[0090] σ2: Tensile stress measured when strain ε2 = 0.05

[0091] In the tire seal 1 of this embodiment, the maximum stress value of the sealing material layer 11 at 23°C is preferably 1.0 N / 10 mm or more, more preferably 3.0 N / 10 mm or more, and even more preferably 5.0 N / 10 mm or more. This maximum stress value is preferably 20.0 N / 10 mm or less, more preferably 10.0 N / 10 mm or less, and even more preferably 8.0 N / 10 mm or less. Within the above-mentioned numerical range, it becomes easier to peel off the sealing material layer 11 that has been first adhered to the tire. That is, recyclability becomes better. It should be noted that this maximum stress value is obtained by converting the maximum stress value observed during the tensile test into a value per 10 mm width.

[0092] The maximum stress at 23°C of the sealing material layer 11 can be increased, for example, by increasing the content of thermoplastic elastomer contained in the sealing material layer 11.

[0093] The elongation at break of the sealing material layer 11 at 23°C is preferably 100% or more, more preferably 500% or more, even more preferably 1000% or more, even more preferably 2000% or more, and particularly preferably 3000% or more. This elongation at break is preferably 8000% or less, more preferably 7000% or less, and even more preferably 6000% or less. Within the above-mentioned numerical range, the sealing performance of the sealing material layer 11 is improved. Furthermore, even when the sealing material layer 11 is adhered to the curved surface of the tire, it adheres firmly. It should be noted that the above-mentioned elongation at break is a value measured under the conditions of the tensile test described above.

[0094] The elongation at break at 23°C of the sealing material layer 11 can be increased, for example, by increasing the content of the softener contained in the sealing material layer 11.

[0095] The tensile stress relaxation rate of the sealing material layer 11 at 23°C is preferably less than 85%, more preferably less than 80%, and even more preferably less than 75%. This tensile stress relaxation rate is preferably 50% or more, more preferably 60% or more, and even more preferably 65% ​​or more. Within the above numerical range, there are advantages such as: when a hole is made in the tire, the sealing material layer blocks at least a portion of the hole, and then the sealing material layer stops flowing and remains, thereby improving the sealing performance. Furthermore, it has the advantage of easily maintaining the tire sealing sheet 1 in a wound state. Additionally, it has the aforementioned advantage of improved recyclability.

[0096] The tensile stress relaxation rate of the sealing material layer 11 at 23°C can be reduced, for example, by decreasing the content of thermoplastic elastomer contained in the sealing material layer 11.

[0097] The tensile stress relaxation rate mentioned above is calculated based on the results obtained under the following test conditions and according to the following formula.

[0098] [Experimental Conditions]

[0099] Using a 10mm wide sealing material layer 11 as a test piece, with the distance between the clamps set to 10mm, the test piece was stretched at 500mm / min at 23℃ until the elongation reached 100%, and then left to stand for 100 seconds.

[0100] Tensile stress relaxation rate [%] = 100 × [(PQ) / P]

[0101] P: Load at 100% elongation; Q: Load after 100 seconds from 100% elongation The preferred mass per unit area of ​​the sealing material layer 11 is 1800 g / m². 2 The following is more preferably 1500g / m2 The following is a further preferred value: 1200g / m 2 The following is a preferred mass per unit area of ​​the sealing material layer 11: 100 g / m². 2 The above, more preferably 150g / m 2 The above is further preferred to be 200g / m 2 The above values ​​indicate that, within the range described above, it is possible to reduce the weight of the tire sealant 1 while maintaining the various properties of the sealing material layer 11.

[0102] The density of the sealing material layer 11 is preferably 1.20 g / cm³. 3 The following is more preferably 1.10 g / cm³ 3 The following is a further preferred value of 1.00 g / cm³. 3 The following applies. The preferred mass per unit area of ​​the sealing material layer 11 is 0.70 g / cm³. 3 The above, more preferably 0.80 g / cm 3 The above is further preferred to be 0.90 g / cm³. 3 The above values ​​indicate that, within the range described above, it is possible to reduce the weight of the tire sealant 1 while maintaining the various properties of the sealing material layer 11.

[0103] The adhesion strength of the sealing material layer 11 to the tire at -5°C is preferably 0.5 N / 10 mm or more, more preferably 1.0 N / 10 mm or more, and even more preferably 2.0 N / 10 mm or more. This further suppresses the peeling of the sealing material layer 11 from the tire at low temperatures. This adhesion strength is preferably 15.0 N / 10 mm or less, more preferably 10.0 N / 10 mm or less, and even more preferably 8.0 N / 10 mm or less.

[0104] The adhesion strength of the sealing material layer 11 to the tire at 23°C is preferably 0.5 N / 10 mm or more, more preferably 1.0 N / 10 mm or more, and even more preferably 2.0 N / 10 mm or more. This further suppresses the peeling of the sealing material layer 11 from the tire. This adhesion strength is preferably 15.0 N / 10 mm or less, more preferably 10.0 N / 10 mm or less, and even more preferably 5.0 N / 10 mm or less.

[0105] The adhesion strength of the sealing material layer 11 to the tire at 60°C is preferably 0.1 N / 10 mm or more, more preferably 0.2 N / 10 mm or more. This further suppresses the peeling of the sealing material layer 11 from the tire at high temperatures. This adhesion strength is preferably 1.5 N / 10 mm or less, more preferably 1.2 N / 10 mm or less, and even more preferably 1.0 N / 10 mm or less.

[0106] After the sealing material layer 11 is subjected to 30 days at 100°C, the adhesion strength of the sealing material layer 11 to the tire at 23°C is preferably 10.0 N / 10 mm or less, more preferably 8.0 N / 10 mm or less. This provides the aforementioned advantage of improved recyclability. The adhesion strength can be 1.0 N / 10 mm or more, or 2.0 N / 10 mm or more.

[0107] The adhesion of the sealing material layer 11 to the tire at various temperatures can be increased, for example, by increasing the content of the tackifier contained in the sealing material layer 11.

[0108] The adhesive strength was measured as follows.

[0109] (1) Cut a 20mm wide piece from the 0.5mm thick sealing material layer as a test piece for measurement.

[0110] (2) A polyethylene terephthalate (PET) resin film (25 μm thick) is laminated onto one side of the test piece to create a laminate.

[0111] (3) Cured the laminate and tubeless tire at 23°C and 50%RH for 1 hour. The tubeless tire was Formula Pro Hookless Tubeless RBCC 700×25C (model 190636, manufactured by Inoue Rubber Industry Co., Ltd.).

[0112] (4) Under conditions of 23°C and 50%RH relative humidity, the exposed surface of the sealing material layer in the laminate is adhered to the inner surface of the tubeless tire. It should be noted that the adhesion is performed by rolling a 2kg roller back and forth once.

[0113] (5) The tubeless tire with the laminated sealing material layer bonded to it was cured for another 30 minutes at a specified temperature (23°C) and relative humidity of 50%RH. Then, using a tensile testing machine, under the above-mentioned specified temperature conditions, at a peel angle of 180° and a tensile speed of 300 mm / min, the adhesion force (peel force) of the sealing material layer to the tubeless tire was measured. The adhesion force was measured using three test pieces, and the arithmetic mean was used as the value of the adhesion force.

[0114] The sealing material layer 11 preferably has a thickness retention rate of 60% or more, more preferably 70% or more, and even more preferably 80% or more. This results in good dimensional stability when the sealing material layer 11 is stored in a wound state. The thickness retention rate is a value obtained as follows.

[0115] A sealant layer was cut into squares with sides of 1 cm and sandwiched between two release liner gaskets. This was then further sandwiched between 3 mm thick SUS304 sheets. A load of 200 g was applied to both sides of the two SUS304 sheets, and the sheets were left to stand at 50°C for 3 days. The thickness of the sealant layer was then measured. The thickness of the sealant layer after standing (thickness retention rate) was then expressed as a percentage relative to the thickness of the sealant layer before standing at 50°C for 3 days.

[0116] After the sealing material layer 11 is left to stand at 50°C for 3 days as described above, the protrusion length of the part that protrudes the most from its original size (1 cm square) is preferably less than 2 mm, more preferably less than 1 mm. As a result, the dimensional stability when the sealing material layer 11 is stored in a rolled-up state can be improved.

[0117] The sealing material layer 11 may contain, for example, an elastomeric component such as a thermoplastic elastomer. Examples of thermoplastic elastomers include styrene-based thermoplastic elastomers and acrylic-based thermoplastic elastomers.

[0118] Examples of styrene-based thermoplastic elastomers include styrene-ethylene block copolymers, styrene-isoprene block copolymers, styrene-isobutene block copolymers, styrene-butadiene block copolymers, and styrene-ethylene-propylene block copolymers. Each of these copolymers may contain both diblock and triblock copolymers.

[0119] Specific examples of the above-mentioned triblock copolymers include: styrene-ethylene-butadiene-styrene block copolymer (SEBS), styrene-isoprene-styrene block copolymer (SIS), styrene-isobutylene-styrene block copolymer (SIBS), styrene-butadiene-styrene block copolymer (SBS), or styrene-ethylene-propylene-styrene block copolymer (SEPS), etc.

[0120] Examples of the aforementioned acrylic thermoplastic elastomers include acrylic rubbers that have at least one structural unit of (meth)acrylate in their molecule. Examples of acrylic rubbers include copolymers of (meth)acrylate and 2-chloroethyl vinyl ether, copolymers of (meth)acrylate and acrylonitrile, and copolymers of (meth)acrylate and acrylic acid.

[0121] The above-mentioned thermoplastic elastomer preferably includes the above-mentioned styrene-based thermoplastic elastomer, and more preferably includes styrene-isoprene-styrene block copolymer (SIS) as a styrene-based thermoplastic elastomer.

[0122] The weight-average molecular weight of the thermoplastic elastomer is preferably 20,000 or more and 1.5 million or less. This weight-average molecular weight can be determined by GPC (gel permeation chromatography) as a conversion value for standard polystyrene. The above-mentioned weight-average molecular weight can be determined using the HLC-8420 GPC manufactured by Tosoh Corporation according to the following determination method and conditions.

[0123] [Preparation of the test sample]

[0124] (1) Prepare a 1.0 g / L THF solution from the sample collected from the sealing material layer containing thermoplastic elastomer and let it stand overnight.

[0125] (2) The THF solution after standing overnight was filtered using a membrane filter with a pore size of 0.45 μm, and the resulting filtrate was used as the test sample.

[0126] [GPC Measurement Conditions]

[0127] • Pillar: A pillar consisting of TSKgel SuperHZM-H, TSKgel SuperHZ4000, TSKgel SuperHZ3000, and TSKgel SuperHZ200 (all manufactured by Tosoh Corporation) connected in series using a clamping method.

[0128] • Column dimensions: 6.0mm I.D. × 150mm each

[0129] • Elution buffer: THF

[0130] • Flow rate: 0.6 mL / min

[0131] Column temperature: 40℃

[0132] • Detector: RI

[0133] • Injection volume: 20 μL

[0134] The diblock fraction of the aforementioned styrene-based thermoplastic elastomer is preferably 10% or more, more preferably 15% or more. This diblock fraction is preferably 80% or less. With the diblock fraction of the styrene-based thermoplastic elastomer within the above-mentioned range, the sealing material layer 11 can exhibit more sufficient adhesion over a wide temperature range from low temperature (e.g., -10°C) to high temperature (e.g., 60°C).

[0135] The above-mentioned biblock ratio is calculated using the following formula.

[0136] Diblock copolymer percentage (mass %) = 100 × [parts by mass of diblock copolymer / (parts by mass of diblock copolymer + parts by mass of triblock copolymer)]

[0137] Having determined the diblock copolymer ratio through chemical analysis, the diblock copolymer ratio was determined using the following method. Specifically, the molecular weight of the styrene-based thermoplastic elastomer was determined by gel permeation chromatography (GPC), and the diblock copolymer ratio was calculated based on the area ratio of the peaks attributed to the diblock copolymers to the peaks attributed to the triblock copolymers in the resulting graph. It should be noted that the GPC method was performed under the aforementioned GPC determination conditions.

[0138] The diblock ratio of styrene-based thermoplastic elastomers can be adjusted by changing the ratio of polymerization initiator to coupling agent used during polymerization (coupling agent dosage / polymerization initiator dosage).

[0139] The styrene content (styrene amount) in styrene-based thermoplastic elastomers is preferably 10% by mass or more, more preferably 13% by mass or more, and even more preferably 15% by mass or more. The styrene content in styrene-based thermoplastic elastomers is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less.

[0140] The sealing material layer 11 may also include softeners, tackifiers, anti-aging agents (antioxidants, etc.).

[0141] Examples of softeners mentioned above include: paraffin waxes, waxes, cycloalkanes, aromatic compounds, asphalt, drying oils (such as linseed oil), animal and vegetable oils, petroleum oils (such as process oils), polybutene, polyisobutylene, ethylene-α-olefin copolymers, low molecular weight polyethylene glycol, phthalates, phosphate esters, stearic acid or its esters, or alkyl sulfonates. A softener may contain one or more of these components.

[0142] Relative to 100 parts by weight of the aforementioned thermoplastic elastomer, the sealing material layer 11 preferably contains 10 parts by weight or more of the aforementioned softener, more preferably 20 parts by weight or more of the aforementioned softener, and even more preferably 30 parts by weight or more of the aforementioned softener. Relative to 100 parts by weight of the aforementioned thermoplastic elastomer, the sealing material layer 11 preferably contains 150 parts by weight or less of the aforementioned softener, more preferably 130 parts by weight or less of the aforementioned softener, and even more preferably 120 parts by weight or less of the aforementioned softener. Within the above numerical ranges, the sealing material layer 11 can possess appropriate flexibility.

[0143] Examples of tackifiers mentioned above include: rosin resins, terpene resins, styrene resins, petroleum resins (hydrocarbon resins), phenolic resins, or hydrogenated resins obtained by hydrogenating these resins. Tackifiers may contain one or more of these components alone.

[0144] Examples of rosin-type resins include rosin resin, rosin ester resin, and rosin phenol resin.

[0145] Examples of terpene resins include compounds having structural units derived from isoprene. Specifically, examples include terpene resins, aromatic modified terpene resins, and terpene phenolic resins.

[0146] Examples of styrene-based resins include copolymers of styrene monomers such as α-methylstyrene or β-methylstyrene with aliphatic monomers.

[0147] Examples of petroleum-based resins include: C5 hydrocarbon resins, which are polymers of C5 fractions such as pentene, isoprene, isoprene, and at least 1,3-pentadiene produced by the thermal decomposition of naphtha; and C9 hydrocarbon resins (aromatic petroleum resins), which are polymers of C9 fractions such as indene or vinyltoluene produced by the thermal decomposition of naphtha.

[0148] Examples of phenolic resins include alkylphenol resins, xylene-formaldehyde resins, methyl phenolic resins, and phenolic varnish resins.

[0149] The sealing material layer 11 preferably contains a petroleum-based resin as a tackifier.

[0150] The sealing material layer 11 preferably contains 50 parts or more of a tackifier relative to 100 parts by weight of thermoplastic elastomer, more preferably 70 parts or more of a tackifier, and even more preferably 90 parts or more of a tackifier.

[0151] Relative to 100 parts by weight of thermoplastic elastomer, the sealing material layer 11 preferably contains 400 parts by weight or less of a tackifier, more preferably 380 parts by weight or less of a tackifier, even more preferably 350 parts by weight or less of a tackifier, and even more preferably 140 parts by weight or less of a tackifier.

[0152] As the aforementioned anti-aging agents, conventionally known anti-aging agents can be used. Examples of anti-aging agents include: phosphorus-containing anti-aging agents, phenolic anti-aging agents, hindered amine anti-aging agents, benzotriazole anti-aging agents, aromatic amine anti-aging agents, sulfur-containing anti-aging agents, etc.

[0153] The sealing material layer 11 contains an anti-aging agent, which can inhibit the oxidation and deterioration of the thermoplastic elastomer contained in the sealing material layer 11. The anti-aging agent may contain only one of the above-mentioned components, or it may contain two or more of them.

[0154] Relative to 100 parts by weight of the above-mentioned thermoplastic elastomer, the sealing material layer 11 may contain 1 part by weight or more of an anti-aging agent, or 2 parts by weight or more of an anti-aging agent, or 3 parts by weight or more of an anti-aging agent.

[0155] Relative to 100 parts by weight of the above-mentioned thermoplastic elastomer, the sealing material layer 11 may contain 10 parts by weight or less of an anti-aging agent, or 8 parts by weight or less of an anti-aging agent, or 6 parts by weight or less of an anti-aging agent.

[0156] The sealing material layer 11 may also include filler materials. Examples of filler materials include: calcium carbonate (e.g., heavy calcium carbonate or light calcium carbonate), calcium stearate, talc, titanium dioxide, silicon dioxide, magnesium oxide, etc.

[0157] (Substrate layer)

[0158] In addition to the sealing material layer 11, the tire sheet of this embodiment may also have a substrate layer 12. The substrate layer 12 may be, for example, as... Figure 1A As shown, it overlaps on one side of the sealing material layer 11. The substrate layer 12 can also be, for example, as shown... Figure 1C The configuration shown is between two sealing material layers 11.

[0159] The substrate layer 12 is composed of a sheet formed of various materials. The substrate layer 12 supports the sealing material layer 11 in a manner that maintains the prescribed shape. The substrate layer 12 overlaps the surface of the sealing material layer 11 opposite to the surface to which it is adhered. Therefore, the substrate layer 12 can protect one side of the sealing material layer 11. The substrate layer 12 also functions as an anti-adhesion layer.

[0160] The substrate layer 12 is preferably composed of a sheet material selected from the group consisting of fiber sheets, foam sheets, solid sheets, and multilayer sheets formed by stacking at least two of these.

[0161] The materials mentioned above can be organic materials such as cotton, wool, hemp, pulp (cellulose), rubber, and plastic; inorganic materials such as carbon, glass, ceramics, and metals; or mixtures thereof.

[0162] As the sheet material, organic fiber sheets, inorganic fiber sheets, rubber foam sheets, plastic foam sheets, solid rubber sheets (non-foamed sheets), solid plastic sheets (non-foamed sheets), solid metal sheets, or sheets with solid plastic sheets laminated on solid metal sheets can be used. Among these, fiber sheets are preferred.

[0163] The fibers constituting the above-mentioned fiber sheet can be synthetic resin fibers such as synthetic plastic fibers and synthetic rubber fibers; natural fibers such as cellulose fibers; or semi-synthetic fibers; or organic fibers. The fibers constituting the above-mentioned fiber sheet can also be metal fibers such as copper fibers, aluminum fibers, and iron fibers; glass fibers; basalt fibers; alumina fibers; ceramic fibers such as rock wool; or inorganic fibers such as carbon fibers.

[0164] The fibers constituting the above-mentioned fiber sheet are preferably the synthetic resin fibers. Examples of such synthetic resin fibers include fibers containing thermoplastic resins and fibers containing thermosetting resins. The synthetic resin fibers are preferably fibers containing thermoplastic resins.

[0165] Examples of thermoplastic resins mentioned above include: polyolefin resins such as polyethylene (PE) and polypropylene (PP); polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polylactic acid (PLA), and polybutylene succinate (PBS); polyamide resins such as polyamide 6 or polyamide 6,6; or cellulose resins such as cellulose acetate. These thermoplastic resins can be used alone or in combination of two or more.

[0166] Of these, polyolefin resins or polyester resins are preferred as the aforementioned thermoplastic resins. Polypropylene (PP) is preferred as the aforementioned polyolefin resin. Polyethylene terephthalate (PET) is preferred as the aforementioned polyester resin.

[0167] The fiber sheet can be a non-woven fabric sheet or a woven fabric sheet.

[0168] The nonwoven fabric sheet can be manufactured by various common methods. The nonwoven fabric sheet can be manufactured by either a dry process or a wet process.

[0169] Examples of nonwoven fabric sheets include: spunbond nonwoven fabric sheets, thermally bonded nonwoven fabric sheets, chemically bonded nonwoven fabric sheets, stitch-bonded nonwoven fabric sheets, needle-punched nonwoven fabric sheets, meltblown nonwoven fabric sheets, spunlace nonwoven fabric sheets, or steam-jet nonwoven fabric sheets, etc.

[0170] The preferred unit area weight of the nonwoven fabric sheet is 10 g / m². 2 The above, more preferably 20g / m 2 The above is further preferred to be 30g / m 2 The above. The preferred unit area weight of the nonwoven fabric sheet is 200 g / m². 2 The following is more preferably 180g / m 2 The following is a further preferred value: 160g / m 2 the following.

[0171] Within the aforementioned range of unit area weight, the substrate layer 12, composed of the nonwoven fabric sheet, possesses sufficient tensile strength. Furthermore, it can prevent the sealing material layer 11 from peeling off the inner surface of the tire due to excessive rigidity of the substrate layer 12.

[0172] The woven fabric sheet can be manufactured using various common looms. The fabric sheet can be woven using any weaving method. Examples of woven fabric sheets include: plain weave fabric sheets, twill weave fabric sheets, or satin weave fabric sheets, etc.

[0173] Compared to solid rubber or plastic sheets, the fiber sheets described above have an advantage in terms of high puncture strength when foreign objects with sharp tips (such as nails, glass shards, etc.) are inserted.

[0174] On the other hand, when the substrate layer 12 is composed solely of fiber sheets, components such as tackifiers that may be present in the sealing material layer 11 may migrate into the substrate layer 12. From the viewpoint of sufficiently suppressing such component migration, the sheet constituting the substrate layer 12 is preferably a multilayer sheet formed by laminating fiber sheets and solid sheets. In the case where the substrate layer 12 is composed of such a multilayer sheet, it is preferable that the solid sheet of the multilayer sheet overlaps with the sealing material layer 11. An example of such a multilayer sheet can be cited as an example: a multilayer sheet formed by laminating fiber sheets and solid sheets (e.g., polyethylene sheets or polypropylene sheets) of polyolefin resins with a thickness thinner than the fiber sheets.

[0175] The sheet constituting the substrate layer 12 can also be a multilayer sheet formed by laminating spunbond nonwoven fabric and meltblown nonwoven fabric with fibers finer and smaller mesh than the spunbond nonwoven fabric. When the substrate layer 12 is composed of such a multilayer sheet, it is preferable that the meltblown nonwoven fabric of the multilayer sheet overlaps with the sealing material layer 11.

[0176] The sheet constituting the substrate layer 12 can also be a solid plastic sheet (non-foamed sheet). Examples of solid plastic sheets include thermoplastic polyurethane films made of thermoplastic polyurethane resin. Commercially available products containing the aforementioned thermoplastic polyurethane film include, for example, "Tough Grace TG88-I 25 / 50" manufactured by Takeda Industries, Ltd. It should be noted that "Tough Grace TG88-I 25 / 50" is obtained by laminating a 50μm thick polyethylene release liner on one side of a 25μm thick thermoplastic polyurethane film.

[0177] The thickness of the substrate layer 12 is preferably 5 μm or more, more preferably 8 μm or more, even more preferably 10 μm or more, even more preferably 15 μm or more, and even more preferably 20 μm or more.

[0178] The thickness of the substrate layer 12 is preferably 10 mm or less, more preferably 5 mm or less, even more preferably 3 mm or less, even more preferably 1 mm or less, and even more preferably 100 μm or less.

[0179] By ensuring the thickness of the substrate layer 12 is within the aforementioned range, the sealing sheet 1 for pneumatic tires exhibits excellent lightweight properties, improving workability when bonded to tires with highly curved surfaces, such as bicycle tires. Furthermore, in embodiments incorporating the release liner described later, it is easy to maintain a roll shape.

[0180] The tensile modulus of the substrate layer 12 at 23°C is preferably 20 MPa or less, more preferably 18 MPa or less, and even more preferably 15 MPa or less. The tensile modulus of the substrate layer 12 at 23°C is preferably 5 MPa or more, more preferably 8 MPa or more, and even more preferably 10 MPa or more. Within the above numerical ranges, the sealing performance of the substrate layer tape 10 (hereinafter, also simply referred to as substrate layer tape 10), which is composed of at least the substrate layer 12 and the sealing material layer 11, can be improved. The substrate layer tape 10 is, for example, a laminate of the substrate layer 12 and the sealing material layer 11.

[0181] The thickness of the adhesive tape 10 with substrate layer, which is composed of at least a sealing material layer 11 and a substrate layer 12 (e.g., a laminate), is preferably 60 μm or more, more preferably 100 μm or more, even more preferably 150 μm or more, and even more preferably 200 μm or more.

[0182] The thickness of the adhesive tape 10 with substrate layer is preferably 2000 μm or less, more preferably 1500 μm or less, even more preferably 1200 μm or less, and even more preferably 1000 μm or less.

[0183] The tensile modulus of the adhesive tape 10 with the substrate layer at 23°C is preferably 500 MPa or less, more preferably 100 MPa or less, and even more preferably 50 MPa or less. The tensile modulus of the adhesive tape 10 with the substrate layer at 23°C is preferably 1 MPa or more, more preferably 2 MPa or more, and even more preferably 3 MPa or more. Within the above numerical ranges, the adhesive tape 10 with the substrate layer, when adhered to the inner surface of the tire, can better follow the deformation of the tire, thereby achieving good adhesion and good sealing. It should be noted that this tensile modulus is measured in the same manner as the tensile modulus of the sealing material layer 11 described above.

[0184] The maximum stress of the adhesive tape 10 with the substrate layer at 23°C is preferably 10 N / 10 mm or more, more preferably 15 N / 10 mm or more, and even more preferably 20 N / 10 mm or more. The maximum stress of the adhesive tape 10 with the substrate layer at 23°C is preferably 250 N / 10 mm or less, more preferably 200 N / 10 mm or less, and even more preferably 150 N / 10 mm or less. Within the above-mentioned numerical range, the adhesive tape 10 with the substrate layer is easier to peel off from the inner surface of the tire, and its recyclability is improved. It should be noted that this maximum stress is measured in the same manner as the maximum stress of the sealing material layer 11 described above.

[0185] The elongation at break of the adhesive tape 10 with the substrate layer at 23°C is preferably 100% or more, more preferably 300% or more, and even more preferably 500% or more. The elongation at break of the adhesive tape 10 with the substrate layer at 23°C is preferably 1200% or less, more preferably 1000% or less. Within the above numerical ranges, the following advantages are achieved: the sealing performance of the sealing material layer 11 is improved, and the sealing material layer 11 adheres more firmly even to the curved surfaces of the tire. It should be noted that this elongation at break is measured in the same manner as the elongation at break of the sealing material layer 11.

[0186] The ratio of the thickness of the substrate layer 12 to the thickness of the adhesive tape 10 (the percentage of the substrate layer thickness in the total thickness of the adhesive tape) is preferably 0.3 (30%) or less, more preferably 0.2 (20%) or less, and even more preferably 0.15 (15%) or less. This makes it easier to adhere the sealing material layer 11 with the adhesive tape 10 to the tire. Furthermore, improved adhesion to the inner surface of the tire results in better sealing. This thickness ratio is preferably 0.01 (1%) or more, more preferably 0.02 (2%) or more, and even more preferably 0.03 (3%) or more. This improves recyclability.

[0187] The tensile stress relaxation rate of the adhesive tape 10 with the substrate layer at 23°C is preferably less than 85%, more preferably less than 70%, and even more preferably less than 60%. The tensile stress relaxation rate of the adhesive tape 10 with the substrate layer at 23°C is preferably 10% or more, more preferably 20% or more, and even more preferably 30% or more. Within the above numerical ranges, there are advantages such as: when a hole is made in the tire, the sealing material layer blocks at least a portion of the hole, and then the sealing material layer does not flow but remains, thereby improving the sealing performance. Furthermore, it has the advantage of easily maintaining the tire sealing sheet 1 in a wound state. Additionally, it has the advantage of improved recyclability. It should be noted that this maximum stress value is measured in the same way as the tensile stress relaxation rate of the sealing material layer 11.

[0188] The stiffness (elasticity) of the substrate layer tape 10 or the sealant layer 11 is preferably low. With low stiffness (elasticity), when the sealant layer 11 is adhered to the curved portion of the inner surface of the tire, which is the adherend, the substrate layer tape 10 or the sealant layer 11 can follow the curved portion more fully while maintaining adhesiveness, resulting in good sealing performance.

[0189] The peel force between the sealing material layer 11 and the substrate layer 12 in the adhesive tape 10 with the substrate layer is preferably greater than the adhesion force of the sealing material layer 11 to the tire at 23°C. This prevents peeling between the sealing material layer 11 and the substrate layer 12 and allows the adhesive tape 10 with the substrate layer to be easily peeled off from the adhered object. Therefore, the recyclability is improved.

[0190] (Peeling off the liner)

[0191] The release liner 20 can be, for example, a resin film or paper. Examples of resin films include polyethylene terephthalate (PET) resin films, polyethylene films, or polypropylene films. Preferably, at least the surface of the release liner 20 that overlaps with the sealing material layer 11 is treated with a surface treatment agent. Examples of surface treatment agents include, for example, silicone-based surface treatment agents and fluorine-containing surface treatment agents.

[0192] The thickness of the peeling liner 20 is preferably 0.02 mm or more, more preferably 0.05 mm or more, and even more preferably 0.08 mm or more.

[0193] The thickness of the peeling liner 20 is preferably 0.8 mm or less, more preferably 0.5 mm or less, and even more preferably 0.3 mm or less.

[0194] By peeling the liner 20 to within the aforementioned thickness range, the pneumatic tire sealing sheet 1 can be easily and smoothly adhered to the curved surface of the tire, thereby improving the sealing performance. Furthermore, it is easy to maintain a rolled shape (wound state).

[0195] The ratio of the thickness of the tire seal 1 to the thickness of the release liner 20 in this embodiment (thickness of the tire seal 1 / thickness of the release liner 20) is preferably 30 or less, more preferably 25 or less, even more preferably 20 or less, and particularly preferably 10 or less.

[0196] The thickness ratio is preferably 0.5 or more, more preferably 1.0 or more, and even more preferably 2.0 or more.

[0197] Therefore, the sealing material layer 11, with the aforementioned release liner 20 attached, can be easily and smoothly adhered to the curved surface of the tire, resulting in better sealing. Furthermore, it is easy to maintain in a rolled state (wound state), and the protrusion of the adhesive paste can be suppressed.

[0198] The tensile modulus of the release liner 20 (especially the release liner 20 attached to the sealant layer 11 during bonding) at 23°C is preferably 4000 MPa or less, more preferably 3000 MPa or less, and even more preferably 2000 MPa or less. The relatively softness of the release liner 20 improves workability when bonding the sealant layer 11 together with the release liner 20 to the inner surface of a tire with a highly curved surface, such as a bicycle tire.

[0199] The tensile modulus of the release liner 20 at 23°C is preferably 50 MPa or more, and more preferably 100 MPa or more. This prevents the release liner 20 from breaking due to pressure during the bonding operation described above.

[0200] The tire seal 1 in this embodiment is preferably strip-shaped. The width (mm) of the pneumatic tire seal 1 is preferably 10% or more, more preferably 25% or more, further preferably 50% or more, and even more preferably 100% or more, relative to the length (mm) along the inner surface of the cross section perpendicular to the circumference of the pneumatic tire in the ETRTO standard.

[0201] The tire sealant 1 of this embodiment preferably has a total light transmittance of 75% or more, and more preferably 80% or more. This results in higher transparency, making it easier to detect lifting and peeling of the sealing material layer 11 after it has been adhered to the substrate. In other words, visual recognizability is improved.

[0202] The total light transmittance mentioned above can be increased, for example, by using materials with high transparency or by combining materials that are easily compatible with each other as components contained in the sealing material layer 11.

[0203] The total transmittance mentioned above can be measured using a haze meter HM-150N (manufactured by Murakami Color Technology Research Institute, measuring beam: entrance opening diameter 20mm, beam diameter 14mm) according to JIS K7361-1:1997.

[0204] In the strip-shaped tire seal 1, preferably, on at least one side in the width direction, the edge of the release liner 20 protrudes outwards from the edge of the sealant layer 11. A so-called dry edge is preferably formed. More preferably, dry edges are formed on both sides in the width direction. It should be noted that when the sealant layer 11 with the substrate layer tape 10 overlaps with the release liner 20, it is preferable that the edge of the release liner 20 protrudes outwards from the edge of the substrate layer tape 10.

[0205] By pinching the dry edge (protruding part), the release liner 20 can be easily peeled off from the sealant layer 11 adhered to the tire. Furthermore, during peeling, the sealant layer 11, which is bonded to the tire, can be prevented from accidentally detaching from the tire. Therefore, the process of attaching the sealant layer 11 to the tire becomes easier. Additionally, in the wound state of the tire sealant 1, adhesive residue protrusion is prevented.

[0206] For the aforementioned dry edge, the protruding length on one side in the width direction is preferably 1.0 mm or more, more preferably 1.5 mm or more, and even more preferably 2.0 mm or more. This protruding length is preferably 4.0 mm or less, more preferably 3.5 mm or less, and even more preferably 3.0 mm or less. Within the above numerical range, as described above, it is easier to peel the release liner 20 from the sealing material layer 11, further suppressing accidental peeling of the sealing material layer 11 from the tire, and further preventing adhesive protrusion in the wound tire sealant 1.

[0207] The tire sealing sheet 1 in this embodiment can be, for example, as follows: Figure 3 The coiled state is shown. Figure 3 As shown, the sealed sheet 1 for an inflatable tire in a wound state may be in a state where it does not have a base material layer, and two release liner 20 are overlapped on both sides of the sealing material layer 11 and wound up.

[0208] On the other hand, the sealed sheet 1 for a pneumatic tire in a wound state may also be in a state where it does not have a base material layer, and a release liner 20 is overlapped on one side of the sealing material layer 11 and on the side opposite to the winding axis (the side facing outward) and wound.

[0209] Alternatively, the sealed sheet 1 for a pneumatic tire in a wound state may also be in a state having a base material layer 12 and a release liner 20, wherein a base material layer 12 is overlapped on one side of the sealing material layer 11 and on the side of the winding axis (the side of the core), and a release liner 20 is overlapped on one side of the opposite side of the sealing material layer 11 (the side facing outward) and wound.

[0210] In the wound state of the tire seal 1, the ratio (percentage) of the maximum width of the wound tire seal 1 to the average width of the tire seal 1 before winding is preferably less than 125%. This ratio can be 100% or more.

[0211] (Example of manufacturing method for sealing sheets for pneumatic tires)

[0212] The method for manufacturing a tire sealant according to this embodiment includes, for example, a step of making a sealing material layer, and, if necessary, a step of overlapping the sealing material layer with a substrate layer, or a step of overlapping the sealing material layer with a release liner 20.

[0213] In the process of making the sealing material layer, for example, a composition containing the above-mentioned elastomer components, as well as softeners, tackifiers and anti-aging agents as needed, is applied to one side of the release liner, and a drying process is performed as needed, thereby making the sealing material layer.

[0214] If the above composition has the property of flowing even at high temperatures without organic solvents (i.e., it has heat-melting properties), a sealing material layer can be made using a hot melt coating machine. In this case, the composition is kneaded and then molded into a sheet.

[0215] The mixing of the above-mentioned composition can be carried out using, for example, a kneader, a Banbury mixer, a mixing roller, or a continuous mixer such as a twin-screw mixer. The sheet forming of the above-mentioned composition can be carried out using forming equipment such as an extruder, a calender roll, or a press (hot press). Specifically, the mixed composition is heated to, for example, a temperature of about 150°C and applied to one side of a release liner or substrate layer to achieve a specified thickness.

[0216] A release liner can be further overlapped on the sealant layer on the release liner as needed. Alternatively, the above composition can be applied to a substrate layer, and a sealant layer overlapping one side of the substrate layer can be prepared in the same manner as described above. A release liner can also be overlapped on the sealant layer on the substrate layer.

[0217] (Example of the use of sealing sheets for pneumatic tires)

[0218] Next, an example of using the pneumatic tire sealing sheet 1 of this embodiment will be described. Hereinafter, an example of using it by attaching the sealing material layer 11 of the pneumatic tire sealing sheet 1 of this embodiment to the inner surface of a bicycle tire will be described.

[0219] Figure 4 This indicates a rough representation of the bicycle wheels. Figure 4 This is a diagram of the wheel viewed from one side along the axis of rotation. The wheel 1000 includes an inflatable tire 100 and a wheel 200 on which the inflatable tire 100 is mounted. The wheel 200 can be disc-shaped or spoked. It should be noted that... Figure 4 The wheel 200 shown is spoked.

[0220] The wheel 200 is positioned inside the outer periphery of the pneumatic tire 100. The wheel 200 includes: a disc-shaped hub 210, which is rotatably mounted on a bicycle fork-like component (not shown); multiple spokes 220 extending radially outward from the outer periphery of the hub 210; and a rim 230, which is fixed by the spokes 220.

[0221] Figure 5 This is a schematic cross-sectional view showing a portion of the wheel cut along a plane perpendicular to the circumference. The rim 230 has a base portion 231 for fixing the outer ends of the spokes 220. The base portion 231 is cylindrical with the axis of rotation of the wheel 1000 as its cylindrical axis. The dimension of the base portion 231 in the cylindrical axis direction (the width direction W of the pneumatic tire 100) is substantially the same as the width of the pneumatic tire 100. The rim 230 also has a flange portion 232. The flange portion 232 extends radially outward from both ends of the base portion 231 in the aforementioned width direction W.

[0222] The pneumatic tire 100 is mounted on the wheel 200 by inserting a portion of the inner side of the radial direction D into the inner side of the flange portion 232.

[0223] like Figure 5 As shown, in the rim 230, the cross-sectional shape of the base portion 231 and the flange portion 232 is U-shaped in a cross-section cut along a plane orthogonal to the circumferential direction R of the wheel 1000. The cross-sectional shape of the pneumatic tire 100 is also U-shaped, but the U-shape of the flange portion 232 is oriented in the opposite direction.

[0224] The pneumatic tire 100 has a ground contact portion 110 that contacts the ground and two sidewall portions 120 that extend from the ground contact portion 110 toward the base portion 231 at the portion furthest from the base portion 231 (the bottom portion of the U-shape). The sidewall portions 120 extend radially inward from both ends of the ground contact portion 110 in the width direction W.

[0225] The pneumatic tire 100 also has a bead portion 140 that protrudes slightly outward in the width direction W at the portion furthest in the radial direction from the ground contact portion 110 (the end of the sidewall portion 120). In addition, the front end of the flange portion 232 of the wheel 200 is curved inward.

[0226] The pneumatic tire 100 is mounted on the rim 230 by at least contacting the inner surface of the flange portion 232 with the bead portion 140 and engaging with the front end of the flange portion 232.

[0227] The wheel 1000 includes a valve 240 for pressurizing a gas, such as air or nitrogen, into the internal space S enclosed by the rim 230 and the pneumatic tire 100. In one example of this embodiment, the pneumatic tire 100 is configured such that, by pressurizing gas from the valve 240, a pair of sidewall portions 120 spaced apart in the width direction W deform in a direction away from each other, thereby making strong contact with the flange portion 232. In this way, the pneumatic tire 100 is securely fixed to the rim 230.

[0228] In a specific example of this embodiment, the wheel 1000 does not have an inner tube that expands due to internal gas within the internal space S. For example... Figure 5As shown, the wheel 1000 includes a tire sealing sheet 1 (sealing material layer 11) that is adhered to the inner surface of the pneumatic tire 100. It should be noted that... Figure 5 In the tire sealing sheet 1 shown, even though it has a base material layer 12, the base material layer 12 is omitted.

[0229] Next, refer to Figure 6A and Figure 6B The mechanism by which the tire sealant 1 is adhered to the inner surface of the pneumatic tire 100 to suppress tire blowout is explained.

[0230] like Figure 6A As shown, when a nail N pierces the pneumatic tire 100, a through hole H is formed in the pneumatic tire 100 from the outer surface (the contact surface with the road surface) to the inner surface. When a bicycle or other vehicle is traveling on the road with the nail N piercing the pneumatic tire 100, the wheel 200 may be damaged by the nail N. Therefore, the rider of the bicycle or other vehicle usually pulls the nail N out of the pneumatic tire 100. As a result, gas may leak from the inside of the pneumatic tire 100 to the outside through the through hole H (see reference). Figure 6B ).

[0231] To prevent gas leakage and seal the through-hole H, the sealing material layer 11 of the tire seal 1 needs to have physical properties that allow it to follow the nail N when it is pulled outwards. Specifically, the sealing material layer 11 needs not only to have sufficient physical properties to adhere to the nail N, but also to have properties such as… Figure 6B The material properties shown are suitable for filling a portion of the through-hole H. Furthermore, after forming the sealant that fills a portion of the through-hole H, the sealant must not be squeezed out of the pneumatic tire 100 by the increased internal pressure due to road travel such as riding a bicycle. Therefore, the sealing material layer 11 forming the sealant needs to have a suitable hardness as a physical property.

[0232] From the above perspective, the sealing material layer 11 needs to not only have sufficient adhesiveness to adhere to the nail N, but also moderate viscoelastic properties to fill part of the through hole H, or to prevent it from being squeezed out of the pneumatic tire 100 when it becomes a sealant in the through hole H.

[0233] In the tire seal 1 of this embodiment, the sealing material layer 11 has a specific range of energy storage viscoelasticity, so it can not only form a seal that fills part of the above-mentioned through hole H, but also sufficiently suppress the seal from being squeezed out to the outside by the internal pressure of the pneumatic tire 100.

[0234] It should be noted that the tire sealing sheet 1 is preferably applied to the inner surface of the pneumatic tire 100 in the following manner. Specifically, when the length along the inner surface 100a from the lowest point 100b (the point closest to the road surface) of the inner surface 100a of the pneumatic tire 100 to the upper end of the pneumatic tire 100 is set to L (mm), it is preferably applied as follows: Figure 5 As shown, the tire sealing sheet 1 is affixed in such a way that it covers an area extending 0.1L (mm) on each side of the width direction W from the lowest point 100b.

[0235] In other words, the tire seal 1 is preferably configured to cover the inner surface of the pneumatic tire 100 with a length of 10% or more of the total length (2L) extending along the inner surface of the pneumatic tire 100 from the upper end of one side to the upper end of the other side. More preferably, the tire seal 1 is configured to cover the inner surface with a length of 15% or more of the total length (2L) extending along the inner surface of the pneumatic tire 100, and even more preferably, it is configured to cover the inner surface with a length of 20% or more. It should be noted that the tire seal 1 may also be configured to cover the inner surface with a length of less than 100% of the total length (2L) along the inner surface of the pneumatic tire 100.

[0236] By attaching the tire sealing sheet 1 to the inner surface 100a of the pneumatic tire 100 as described above, it is possible to prevent nails or the like from piercing the pneumatic tire 100 and causing a blowout.

[0237] The sealing sheet for pneumatic tires in this embodiment is as illustrated above, but the present invention is not limited to the sealing sheet for pneumatic tires illustrated above.

[0238] That is, various forms used in general pneumatic tire sealing sheets and the like can be adopted without compromising the effects of the present invention.

[0239] The matters disclosed in this specification are as described in the first embodiment above, and in one aspect include the following.

[0240] (1) A sealing sheet for a pneumatic tire, wherein the sealing sheet for a pneumatic tire has at least a layer of sealing material to be adhered to the inner surface of the pneumatic tire. When the thickness of the sealing material layer is set to T [mm] and the storage modulus of the sealing material layer at 60°C is set to E [kPa], T and E satisfy the following relationship: [(1000×T) / E]<50.

[0241] The sealing sheet for the pneumatic tire has a sealing material layer. The sealing material layer is sheet-shaped, so it has good adhesion to the inner surface of the tire. The sealing material layer can be easily adhered to the curved part of the inner surface of the tire, can follow the curved part to form a tight seal, and has good sealing performance even when the thickness is relatively thin.

[0242] (2) The sealing sheet for pneumatic tires as described in (1) above, wherein the elongation at break of the sealing material layer at 23°C is 100% or more.

[0243] (3) The sealing sheet for pneumatic tires according to (1) or (2) above, wherein the tensile stress relaxation rate of the sealing material layer at 23°C is less than 85%.

[0244] (4) The sealing sheet for a pneumatic tire according to any one of (1) to (3) above, wherein the sealing material layer comprises an elastomer.

[0245] (5) The sealing sheet for a pneumatic tire according to any one of (1) to (4) above, wherein the sealing sheet for a pneumatic tire further comprises a substrate layer supporting the sealing material layer. The substrate layer is stacked on one side of the sealing material layer, or disposed inside the sealing material layer.

[0246] (6) The sealing sheet for a pneumatic tire according to any one of (1) to (5) above, wherein the adhesive force of the sealing material layer to the tire at -5°C is 1.0 N / 10 mm or more.

[0247] (7) The sealing sheet for pneumatic tires according to (5) above, wherein the elongation at break of the tape with the substrate layer having the sealing material layer and the substrate layer is 100% or more at 23°C.

[0248] (8) The sealing sheet for pneumatic tires according to (5) above, wherein the tensile modulus of the tape with the substrate layer having the sealing material layer and the substrate layer at 23°C is 500 MPa or less.

[0249] (9) The sealing sheet for pneumatic tires according to (5) above, wherein the tensile stress relaxation rate of the tape with the substrate layer having the sealing material layer and the substrate layer at 23°C is less than 85%.

[0250] (10) The sealing sheet for pneumatic tires according to (5) above, wherein the substrate layer is composed of any one of fiber sheet, foam sheet, solid sheet, or laminated sheet obtained by stacking two or more of these sheets.

[0251] (11) The sealing sheet for a pneumatic tire according to any one of (1) to (10) above, wherein the total light transmittance of the sealing sheet for a pneumatic tire is 75% or more.

[0252] (12) The sealing sheet for a pneumatic tire according to any one of (1) to (11) above, wherein a release liner is further provided on at least one side of the sealing material layer. The tensile modulus of the peeling liner at 23°C is below 4000 MPa.

[0253] (13) The sealing sheet for a pneumatic tire as described in (5) above, wherein the sealing sheet for a pneumatic tire is in the form of a strip and is in a wound state. The adhesive tape having the sealing material layer and the substrate layer has a thickness of less than 3 mm, a width of more than 20 mm, and a length of more than 50 cm. The thickness of the sealing material layer is less than 2 mm.

[0254] (14) The sealing sheet for a pneumatic tire according to any one of (1) to (13) above, wherein the sealing sheet for a pneumatic tire is strip-shaped. At least one side of the sealing material layer also has a release liner. On at least one side of the width direction of the sealing sheet for the pneumatic tire, the edge of the release liner protrudes more than 1 mm beyond the edge of the sealing material layer.

[0255] (15) The sealing sheet for a pneumatic tire according to any one of (1) to (14) above, wherein the sealing sheet for a pneumatic tire is strip-shaped. The sealing sheet for the pneumatic tire also includes a substrate layer disposed on one side of the sealing material layer and a release liner disposed on the other side of the sealing material layer. On at least one side of the width direction of the sealing sheet for the pneumatic tire, the edge of the release liner protrudes more than 1 mm beyond the edge of the sealing material layer or the substrate layer.

[0256] (16) A sealing sheet for a pneumatic tire according to any one of (1) to (15) above, wherein the pneumatic tire is a tubeless tire or a tubeless ready tire.

[0257] (17) A sealing sheet for a pneumatic tire according to any one of (1) to (16) above, wherein the pneumatic tire is a bicycle tire or a motorcycle tire.

[0258] The matters disclosed in this specification are as described in the second embodiment above, and in another aspect include the following.

[0259] (1') A sealing sheet for a pneumatic tire, wherein the sealing sheet for a pneumatic tire has at least a layer of sealing material to be adhered to the inner surface of the pneumatic tire. The energy storage modulus of the sealing material layer is less than 500 kPa at -5°C and greater than 10 kPa at 60°C.

[0260] The sealing sheet for the pneumatic tire has a sealing material layer, which is sheet-shaped and therefore has good adhesion to the inner surface of the tire. The sealing material layer can be easily adhered to the curved part of the inner surface of the tire, can follow the curved part to form a tight seal, and has good low-temperature sealing and high-temperature sealing performance.

[0261] (2') The sealing sheet for a pneumatic tire as described in (1') above, wherein the elongation at break of the sealing material layer at 23°C is 100% or more.

[0262] (3') The sealing sheet for pneumatic tires according to (1') or (2') above, wherein the tensile stress relaxation rate of the sealing material layer at 23°C is less than 85%.

[0263] (4') A sealing sheet for a pneumatic tire according to any one of (1') to (3') above, wherein the mass of the sealing material layer per unit area is 1800 g / m². 2 the following.

[0264] (5') A sealing sheet for an inflatable tire according to any one of (1') to (4') above, wherein the sealing material layer comprises an elastomer.

[0265] (6') A sealing sheet for a pneumatic tire according to any one of (1') to (5') above, wherein the sealing sheet for a pneumatic tire further comprises a substrate layer supporting the sealing material layer. The substrate layer is stacked on one side of the sealing material layer, or disposed inside the sealing material layer.

[0266] (7') A sealing sheet for a pneumatic tire according to any one of (1') to (6') above, wherein the sealing material layer has an adhesion force of 1.0 N / 10 mm or more to the tire at -5°C, and the sealing material layer has an adhesion force of 0.1 N / 10 mm or more to the tire at 60°C.

[0267] (8') The sealing sheet for pneumatic tires according to (6') above, wherein the tensile modulus of the tape with the substrate layer having the sealing material layer and the substrate layer at 23°C is 500 MPa or less.

[0268] (9') The sealing sheet for pneumatic tires as described in (6') above, wherein the elongation at break of the tape with the substrate layer having the sealing material layer and the substrate layer is 100% or more at 23°C.

[0269] (10') According to the sealing sheet for pneumatic tires described in (6') above, the tensile stress relaxation rate of the tape with the substrate layer having the sealing material layer and the substrate layer at 23°C is less than 85%.

[0270] (11') The sealing sheet for pneumatic tires according to (6') above, wherein the substrate layer is composed of any one of fiber sheet, foam sheet, solid sheet, or laminated sheet obtained by laminating two or more of these sheets.

[0271] (12') A sealing sheet for a pneumatic tire according to any one of (1') to (11') above, wherein a release liner is further provided on at least one side of the sealing material layer. The tensile modulus of the peeling liner at 23°C is below 4000 MPa.

[0272] (13') A sealing sheet for a pneumatic tire according to any one of (1') to (12') above, wherein the sealing sheet for a pneumatic tire is in a strip shape and in a wound state. The adhesive tape having the sealing material layer and the substrate layer has a thickness of less than 3 mm, a width of more than 20 mm, and a length of more than 50 cm. The thickness of the sealing material layer is less than 2 mm.

[0273] (14') A sealing sheet for a pneumatic tire according to any one of (1') to (13') above, wherein the pneumatic tire is a tubeless tire or a quasi-tubeless tire.

[0274] (15') A sealing sheet for a pneumatic tire according to any one of (1') to (14') above, wherein the pneumatic tire is a bicycle tire or a motorcycle tire.

[0275] The matters disclosed in this specification, as described in the third embodiment above, also include the following in another aspect.

[0276] (1”) A sealing sheet for a pneumatic tire, wherein the sealing sheet for a pneumatic tire has at least a layer of sealing material to be adhered to the inner surface of the pneumatic tire. The energy storage modulus of the sealing material layer at 23°C is below 350 kPa, and after 30 days at 100°C, the energy storage modulus of the sealing material layer at 60°C is above 10 kPa. The maximum stress of the sealing material layer at 23°C is greater than 1.0 N / 10 mm.

[0277] The sealing sheet for the pneumatic tire has a sealing material layer that is sheet-shaped, thus providing good adhesion to the inner surface of the tire. The sealing material layer can be easily adhered to the curved portion of the inner surface of the tire, can follow the adhered curved portion to form a tight seal, and has both good sealing and recyclability.

[0278] (2”) The sealing sheet for pneumatic tires as described in (1”) above, wherein the tensile stress relaxation rate of the sealing material layer at 23°C is less than 85%.

[0279] (3”) The sealing sheet for a pneumatic tire according to (1”) or (2”) above, wherein the adhesive force of the sealing material layer to the tire at 23°C is more than 0.5 N / 10 mm, and the adhesive force of the sealing material layer to the tire at 23°C after 30 days at 100°C is less than 10.0 N / 10 mm.

[0280] (4”) A sealing sheet for a pneumatic tire according to any one of (1”) to (3”) above, wherein the elongation at break of the sealing material layer at 23°C is 100% or more.

[0281] (5”) A sealing sheet for an inflatable tire according to any one of (1”) to (4”) above, wherein the sealing material layer comprises an elastomer.

[0282] (6”) A sealing sheet for a pneumatic tire according to any one of (1”) to (5”) above, wherein the sealing sheet for a pneumatic tire further comprises a substrate layer supporting the sealing material layer. The substrate layer is stacked on one side of the sealing material layer, or disposed inside the sealing material layer.

[0283] (7”) According to the sealing sheet for pneumatic tires described in (6”) above, the maximum stress of the tape with the substrate layer at 23°C having the sealing material layer and the substrate layer is 10 N / 10 mm or more.

[0284] (8”) The sealing sheet for pneumatic tires according to (7”) above, wherein the tensile modulus of the tape with substrate layer at 23°C is less than 500 MPa.

[0285] (9”) The sealing sheet for pneumatic tires according to (6”) above, wherein the elongation at break of the tape with the substrate layer having the sealing material layer and the substrate layer is 100% or more at 23°C.

[0286] (10”) According to the above (6”) sealing sheet for pneumatic tires, wherein the tensile stress relaxation rate of the tape with the substrate layer having the sealing material layer and the substrate layer at 23°C is less than 85%.

[0287] (11”) The sealing sheet for a pneumatic tire as described in (6”) above, wherein the substrate layer is composed of any one of fiber sheet, foam sheet, solid sheet, or laminated sheet obtained by laminating two or more of these sheets.

[0288] (12”) The sealing sheet for an inflatable tire as described in (6”) above, wherein the sealing sheet for an inflatable tire is in the form of a strip and is in a wound state. The adhesive tape having the sealing material layer and the substrate layer has a thickness of less than 3 mm, a width of more than 20 mm, and a length of more than 50 cm. The thickness of the sealing material layer is less than 2 mm.

[0289] (13”) A sealing sheet for an inflatable tire according to any one of (1”) to (12”) above, wherein the inflatable tire is a tubeless tire or a quasi-tubeless tire.

[0290] (14”) A sealing sheet for a pneumatic tire according to any one of (1”) to (13”) above, wherein the pneumatic tire is a bicycle tire or a motorcycle tire.

[0291] Example

[0292] Next, the invention will be described in more detail by means of experimental examples, but the following embodiments are used to illustrate the invention in more detail and are not intended to limit the scope of the invention.

[0293] The following details the raw materials used to manufacture seals for pneumatic tires.

[0294] [Raw material for the sealing layer]

[0295] (A) Thermoplastic elastomers

[0296] • Styrene-isoprene block copolymer (containing SIS as the main component)

[0297] 19% styrene by mass, 30% diblock fraction by mass, and mass-average molecular weight of 200,000.

[0298] The product name is "Quintac3450" manufactured by Zeon Corporation of Japan.

[0299] (B) Tackifier

[0300] (B-1)

[0301] "Quinton N180" unhydrogenated hydrocarbon resin (manufactured by Zeon Corporation, Japan)

[0302] Softening point 98℃, number average molecular weight 970

[0303] (B-2)

[0304] "T-REZ RB100" unhydrogenated hydrocarbon resin (manufactured by ENEOS)

[0305] Softening point 98℃, number average molecular weight 1230

[0306] (C) Softener

[0307] ·(C-1)

[0308] Polybutene, product name "HV-300" (manufactured by ENEOS).

[0309] Number average molecular weight 1400, viscosity (40℃) 26000 mm 2 / s

[0310] (C-2)

[0311] Polybutene, product name "PB1300" (manufactured by DAELIM).

[0312] Number average molecular weight 1300

[0313] (C-3)

[0314] Petroleum-based oil, product name "Diana Process Oil PW-380" (manufactured by Idemitsu Kosan Co., Ltd.)

[0315] Number average molecular weight 1100, viscosity (40℃) 409 mm 2 / s

[0316] (D) Anti-aging agents

[0317] ·(D-1)

[0318] "SONGNOX 1010PW" phenolic antioxidant (manufactured by Songwon Company)

[0319] Melting point 110℃~125℃, molecular weight 1178

[0320] (D-2)

[0321] "Irgafos 168" is a phosphorus-containing processing stabilizer manufactured by BASF.

[0322] Melting point 185℃~187℃, molecular weight 647

[0323] [Substrate Layer]

[0324] The substrate layer with the release film described below was used during manufacturing, but the release film was eventually removed.

[0325] (Base layer only)

[0326] The product name is "NES85" manufactured by Okura Kogyo Co., Ltd.

[0327] Substrate layer: Polyurethane film (thicknesses of 10μm, 30μm, and 50μm)

[0328] Release film: Made of polyethylene resin (60μm thick)

[0329] [Remove the liner]

[0330] • Single-sided treated paper (single-sided silicone-treated kraft paper), thickness 0.1mm

[0331] • Single-sided treated PE (single-sided silicone-treated polyethylene resin film), with a thickness of 0.05mm.

[0332] • Double-sided treated paper (double-sided silicone-treated kraft paper), 0.1mm thick.

[0333] • Double-sided treated PET (double-sided silicone-treated PET resin film), thickness 0.05mm

[0334] <First Implementation Method>

[0335] [Preparation of compositions for use in making sealing material layers]

[0336] Thermoplastic elastomers, tackifiers, and softeners were mixed with the formulations shown in Table 1-1 and stirred while heating to prepare compositions for various sealing material layers (compositions A to D).

[0337] [Table 1-1]

[0338] [Example 1-1]

[0339] The composition shown in Composition A of Table 1-1 was applied to the release liner (single-sided treated paper) to form a sealing material layer. Specifically, while heating the composition to 150°C, a hot melt coating machine was used to apply the sealing material layer to the release liner (single-sided treated paper) to achieve the thickness shown in Table 1-2.

[0340] Next, the separately prepared release liner (single-sided treated PE) is bonded to the sealing material layer to manufacture a sealing sheet for pneumatic tires (hereinafter referred to as a sealing sheet).

[0341] It should be noted that the manufactured sealing strip for pneumatic tires is strip-shaped, with dry edges on both sides in the width direction. That is, the sealing material layer and the release liner are configured such that the edge of the release liner protrudes outward by the length (dry edge width) shown in Table 1-1 beyond the edge of the sealing material layer.

[0342] [Examples 1-2 to 1-6, 1-10 to 1-12]

[0343] Except for changing the combination or structure shown in Tables 1-2 or 1-3, the sealing sheets of each embodiment were manufactured in the same manner as in Example 1-1.

[0344] [Examples 1-7 to 1-9]

[0345] Except for changing the composition or structure shown in Tables 1-3, the sealing sheets of each embodiment were manufactured in the same manner as in Examples 1-1. However, instead of the release liner (single-sided treated PE), the substrate layer with the release film was used, and this substrate layer was bonded to the sealing material layer, and then the release film was removed. It should be noted that the substrate layer is formed with the same shape and size as the release liner and overlaps with it. The dry edges are provided such that the two end edges of the release liner and the substrate layer protrude outwards from the two end edges of the sealing material layer by a predetermined length in the width direction.

[0346] [Comparative Examples]

[0347] Except for changing the combination composition or structure shown in Tables 1-3, the sealing sheets of each embodiment were manufactured in the same manner as in Examples 1-1.

[0348] <Physical Property Determination>

[0349] For the sealing sheets manufactured as described above, the properties of the sealing material layer and the properties of the adhesive tape with the substrate layer, which is a laminate of the sealing material layer and the substrate layer, were measured. Specifically, the storage modulus, tensile modulus, elongation at break, and tensile stress relaxation rate at various temperatures were measured according to the methods described above. The results are shown in Tables 1-2 and 1-3, respectively.

[0350] [Table 1-2]

[0351] [Table 1-3]

[0352] <Adhesion>

[0353] The adhesive strength of the sealing material layers in each embodiment was measured at various temperatures according to the method described above. A tubeless tire (Formula Pro RBCC 700×25C) was used as the bonded object. It should be noted that the adhesive strength of the sealing material layers was measured at 60°C after being stored at 100°C for 30 days (after high-temperature storage). The results are shown in Tables 1-2 and 1-3, respectively.

[0354] [Amount of the sealing material layer protruding after heating]

[0355] A sealant layer was cut into squares with sides of 1 cm and sandwiched between two release liner gaskets. It was then further sandwiched between 3 mm thick SUS304 sheets. A load of 200 g was applied from both sides of the two SUS304 sheets, and the sheets were left to stand at 50°C for 3 days. The length of the sealant layer protruding most from its original size (1 cm square) was then measured. The results are shown in Tables 1-2 and 1-3.

[0356] [Thickness retention rate of the sealing material layer after heating]

[0357] The thickness of the sealing material layer was measured as described above when the protrusion was measured. The thickness of the sealing material layer after standing (thickness retention rate) was then expressed as a percentage relative to the thickness of the sealing material layer before standing for 3 days at 50°C. For example, the thickness retention rate is 100% if the thickness remains unchanged. The results are shown in Tables 1-2 and 1-3, respectively.

[0358] [Roll shape retention]

[0359] Based on the evaluation results of the protrusion amount and thickness retention rate of the sealing material layer, the shape retention was determined according to the following evaluation criteria. The results are shown in Tables 1-2 and 1-3, respectively.

[0360] Good (○): Protrusion less than 2mm and thickness retention rate above 60%.

[0361] Defective (×): Protrusion exceeding 2mm or thickness retention less than 60%.

[0362] [Evaluation of Sealing Performance]

[0363] The sealing performance of a through-hole formed in a pneumatic tire was evaluated using either the sealing material layer of the sealing sheet in each example, or a substrate-layered tape that is a laminate of the sealing material layer and the substrate layer (hereinafter referred to as a test sheet), following the operating procedures. The sealing performance evaluation was carried out at room temperature (23°C).

[0364] (1) A test piece with a planar size of 30mm×50mm was made, and then the sealing material layer of the test piece was attached to the inner surface of the tubeless tire. As a tubeless tire, the product name "IRCRoad Tire (Formula Pro Hookless Tubeless RBCC 700×25C (Model 190636, manufactured by Inoue Rubber Industry Co., Ltd.)" was used.

[0365] (2) The tubeless tire with the test piece attached as described above was mounted on the wheel (manufactured by SHIMANO, product name "WH-RS500", rim dimensions: width 20.8mm, height 24mm). It should be noted that the installation of the tubeless tire on the wheel was carried out without injecting sealant material into the inside of the tubeless tire.

[0366] (3) Inflate the tubeless tire with air until the specified pressure (95 psi (approximately 0.66 MPa)) is reached. Then, observe the pressure change over a certain period of time (approximately one day) and determine the leakage rate V1 (psi / min) of the reference (Ref). That is, determine the leakage rate when no through-hole is formed in the tubeless tire. It should be noted that the pressure is measured by installing a pressure gauge on the valve of the wheel. The pressure measurement is performed with the tubeless tire and wheel as a single unit in a static state. The following pressure measurements are also performed in the same manner.

[0367] (4) Inject air back into the tubeless tire until the specified pressure (95 psi (approximately 0.66 MPa)) is reached, and then insert a 2.1 mm thick (1.2 mm diameter) needle into the area where the test piece is attached to the tire to a depth of 20 mm. Then, remove the needle from the tubeless tire to create a through hole.

[0368] (5) The observation starting point (0 min) is the time when the needle is pulled out and a through hole is formed. The pressure change is observed over a certain period of time (approximately 5 minutes), and the leakage rate V2 (psi / min) after the through hole is formed is calculated. Then, the difference between the leakage rate V2 and the leakage rate V1 (V2-V1) (leakage rate V3) is calculated. The closer the leakage rate V3 is to 0, the better the sealing effect. The sealing performance was then evaluated according to the following evaluation criteria. The evaluation results of the sealing performance at the specified temperature are shown in Tables 1-2 and 1-3, respectively.

[0369] Good (○): 0 ≤ V3 ≤ 1.0

[0370] Defective (×): 1.0 < V3

[0371] [Adhesion to the tire's surface curvature (curves on the tire's surface)]

[0372] The sealing material layer was cut to a width of 35 mm and a length of 100 mm. This sealing material layer was then bonded to the inner surface of the tubeless tire by applying a load of 5 kg three times. It should be noted that, without a substrate layer, the load was applied to the sealing material layer (located between the release liner and the tire) through the release liner. Conversely, with a substrate layer, the load was applied to the sealing material layer (located between the substrate layer and the tire) through the substrate layer. The evaluation was conducted according to the following evaluation criteria. The results are shown in Tables 1-2 and 1-3, respectively. It should be noted that in Examples 1-12, the release liner was hard, thus reducing workability during bonding and resulting in poor results; however, the adhesiveness of the sealing material layer itself was the same as in Examples 1-11.

[0373] Good (〇): The area of ​​the tire peeling off and lifting from the curved surface is less than 50%; Slightly undesirable (△): The area ratio of the raised area is less than 50%, but the area on one side of the sealing material layer sample in one direction of the face is peeled off and raised; Defective (×): The area of ​​the tire that peels off and lifts off the surface is more than 50%.

[0374] [Tire recyclability]

[0375] The sealing material layer was cut to a width of 10 mm and a length of 100 mm. This sealing material layer was pressed onto the inner surface of the tubeless tire and then left to stand at 100°C for 30 days. The sealing material layer was then peeled off at a peel angle of 180 degrees and a peeling speed of 300 mm / min. It should be noted that, without a substrate layer attached to the sealing material layer, a 25 μm thick PET resin film was adhered to it as a backing before peeling. After peeling, the extent to which a portion of the sealing material layer remained on the tire surface was visually confirmed. The results are shown in Tables 1-2 and 1-3.

[0376] 〇 (Good): The residue of sealing material is less than 50%; × (Poor): More than 50% of the sealing material remains. According to the results in Tables 1-2 and 1-3, the sealing material layer of the first embodiment exhibits good sealing performance even when it is relatively thin. In contrast, the sealing material layer of the comparative example, while exhibiting good sealing performance, is relatively thick, or although relatively thin, it exhibits poor sealing performance.

[0377] <Second Implementation Method>

[0378] [Preparation of compositions for use in making sealing material layers]

[0379] Thermoplastic elastomers, tackifiers, and softeners were mixed with the formulations shown in Table 2-1 and stirred while heating to prepare compositions for various sealing material layers (compositions a to e).

[0380] [Table 2-1]

[0381] [Example 2-1]

[0382] The composition shown in composition a of Table 2-1 was applied to the release liner (single-sided treated paper) to form a sealing material layer. Specifically, while heating the composition to 150°C, a hot melt coating machine was used to apply the sealing material layer to the release liner (single-sided treated paper) to achieve the thickness shown in Table 2-2.

[0383] Next, the separately prepared release liner (single-sided treated PE) is bonded to the sealing material layer to manufacture a sealing sheet for pneumatic tires (hereinafter referred to as a sealing sheet).

[0384] It should be noted that the manufactured sealing strip for pneumatic tires is strip-shaped, with dry edges on both sides in the width direction. That is, the sealing material layer and the release liner are configured such that the edge of the release liner protrudes outward by the length (dry edge width) shown in Table 2-1 beyond the edge of the sealing material layer.

[0385] [Examples 2-2 to 2-6, 2-10 to 2-12]

[0386] Except for changing the combination or structure shown in Table 2-2 or Table 2-3, the sealing sheets of each embodiment were manufactured in the same manner as in Example 2-1.

[0387] [Examples 2-7 to 2-9]

[0388] Except for changing the composition or structure shown in Tables 2-3, the sealing sheets of each embodiment were manufactured in the same manner as in Example 2-1. However, instead of the release liner (single-sided treated PE), the substrate layer with the release film was used, and this substrate layer was bonded to the sealing material layer, and then the release film was removed. It should be noted that the substrate layer is formed with the same shape and size as the release liner, and they overlap each other. The dry edges are provided such that the two end edges of the release liner and the substrate layer protrude outwards from the two end edges of the sealing material layer by a predetermined length in the width direction.

[0389] [Comparative Examples]

[0390] Except for changing the combination or structure shown in Tables 2-3, the sealing sheets of each embodiment were manufactured in the same manner as in Example 2-1.

[0391] <Physical Property Determination>

[0392] For the sealing sheets manufactured as described above, the properties of the sealing material layer and the properties of the adhesive tape with the substrate layer, which is a laminate of the sealing material layer and the substrate layer, were measured. Specifically, the storage modulus, tensile modulus, elongation at break, and tensile stress relaxation rate at various temperatures were measured according to the methods described above. The results are shown in Tables 2-2 and 2-3, respectively.

[0393] [Table 2-2]

[0394] [Table 2-3]

[0395] <Adhesion>

[0396] The adhesive strength of the sealing material layers in each embodiment was measured at various temperatures according to the method described above. A tubeless tire (Formula Pro RBCC 700×25C) was used as the bonded object. It should be noted that the adhesive strength of the sealing material layers was measured at 60°C after being stored at 100°C for 30 days (after high-temperature storage). The results are shown in Tables 2-2 and 2-3, respectively.

[0397] [Amount of the sealing material layer protruding after heating]

[0398] A sealant layer was cut into squares with sides of 1 cm and sandwiched between two release liner gaskets. It was then further sandwiched between 3 mm thick SUS304 sheets. A load of 200 g was applied from both sides of the two SUS304 sheets, and the sheets were left to stand at 50°C for 3 days. The length of the sealant layer protruding most from its original size (1 cm square) was then measured. The results are shown in Tables 2-2 and 2-3.

[0399] [Thickness retention rate of the sealing material layer after heating]

[0400] The thickness of the sealing material layer was measured as described above when the protrusion was measured. The thickness of the sealing material layer after standing (thickness retention rate) was then expressed as a percentage relative to the thickness of the sealing material layer before standing for 3 days at 50°C. For example, the thickness retention rate is 100% if the thickness remains unchanged. The results are shown in Tables 2-2 and 2-3, respectively.

[0401] [Roll shape retention]

[0402] Based on the evaluation results of the protrusion amount and thickness retention rate of the sealing material layer, the shape retention was determined according to the following evaluation criteria. The results are shown in Tables 2-2 and 2-3, respectively.

[0403] Good (○): Protrusion less than 2mm and thickness retention rate above 60%.

[0404] Defective (×): Protrusion exceeding 2mm or thickness retention less than 60%.

[0405] [Evaluation of Sealing Performance]

[0406] The sealing performance of a through-hole formed in a pneumatic tire was evaluated using either the sealing material layer of the sealing sheet in each example, or a substrate-layered tape that is a laminate of the sealing material layer and the substrate layer (hereinafter referred to as a test sheet), following the operating procedures. The sealing performance evaluation was carried out at room temperature (23°C), as well as at low temperature (-5°C) and high temperature (60°C).

[0407] (1) A test piece with a planar size of 30mm×50mm was made, and then the sealing material layer of the test piece was attached to the inner surface of the tubeless tire. As a tubeless tire, the product name "IRCRoad Tire (Formula Pro Hookless Tubeless RBCC 700×25C (Model 190636, manufactured by Inoue Rubber Industry Co., Ltd.)" was used.

[0408] (2) The tubeless tire with the test piece attached as described above was mounted on the wheel (manufactured by SHIMANO, product name "WH-RS500", rim dimensions: width 20.8mm, height 24mm). It should be noted that the installation of the tubeless tire on the wheel was carried out without injecting sealant material into the inside of the tubeless tire.

[0409] (3) Inflate the tubeless tire with air until the specified pressure (95 psi (approximately 0.66 MPa)) is reached. Then, observe the pressure change over a certain period of time (approximately one day) and determine the leakage rate V1 (psi / min) of the reference (Ref). That is, determine the leakage rate when no through-hole is formed in the tubeless tire. It should be noted that the pressure is measured by installing a pressure gauge on the valve of the wheel. The pressure measurement is performed with the tubeless tire and wheel as a single unit in a static state. The following pressure measurements are also performed in the same manner.

[0410] (4) Inject air back into the tubeless tire until the specified pressure (95 psi (approximately 0.66 MPa)) is reached, and then insert a 2.1 mm thick (1.2 mm diameter) needle into the area where the test piece is attached to the tire to a depth of 20 mm. Then, remove the needle from the tubeless tire to create a through hole.

[0411] (5) The observation starting point (0 min) is the time when the needle is pulled out and a through hole is formed. The pressure change is observed over a certain period of time (approximately 5 minutes), and the leakage rate V2 (psi / min) after the through hole is formed is calculated. Then, the difference between the leakage rate V2 and the leakage rate V1 (V2-V1) (leakage rate V3) is calculated. The closer the leakage rate V3 is to 0, the better the sealing effect. The sealing performance was then evaluated according to the following evaluation criteria. The evaluation results of the sealing performance at the specified temperature are shown in Tables 2-2 and 2-3, respectively.

[0412] Good (○): 0 ≤ V3 ≤ 1.0

[0413] Defective (×): 1.0 < V3

[0414] [Adhesion to the tire's surface curvature (curves on the tire's surface)]

[0415] The sealing material layer was cut to a width of 35 mm and a length of 100 mm. This sealing material layer was then bonded to the inner surface of the tubeless tire by applying a load of 5 kg three times. It should be noted that, without a base layer, the load was applied to the sealing material layer (located between the release liner and the tire) through the release liner. Conversely, with a base layer, the load was applied to the sealing material layer (located between the base layer and the tire) through the base layer. The evaluation was conducted according to the following evaluation criteria. The results are shown in Tables 2-2 and 2-3, respectively. It should be noted that in Example 2-12, the release liner was hard, thus reducing workability during bonding and resulting in poor results; however, the adhesiveness of the sealing material layer itself was the same as in Example 2-11.

[0416] Good (〇): The area of ​​the tire peeling off and lifting from the curved surface is less than 50%; Slightly undesirable (△): The area ratio of the raised area is less than 50%, but the area on one side of the sealing material layer sample in one direction of the face is peeled off and raised; Defective (×): The area of ​​the tire that peels off and lifts off the surface is more than 50%.

[0417] [Tire recyclability]

[0418] The sealing material layer was cut to a width of 10 mm and a length of 100 mm. This sealing material layer was pressed onto the inner surface of the tubeless tire and then left to stand at 100°C for 30 days. The sealing material layer was then peeled off at a peel angle of 180 degrees and a peeling speed of 300 mm / min. It should be noted that, without a substrate layer attached to the sealing material layer, a 25 μm thick PET resin film was adhered to it as a backing before peeling. After peeling, the extent to which a portion of the sealing material layer remained on the tire surface was visually confirmed. The results are shown in Tables 2-2 and 2-3.

[0419] 〇 (Good): The residue of sealing material is less than 50%; × (Poor): More than 50% of the sealing material remains. According to the results in Tables 2-2 and 2-3, the sealing material layer of the second embodiment exhibits good low-temperature sealing and high-temperature sealing performance. In contrast, the sealing material layer of the comparative example exhibits poor low-temperature sealing and high-temperature sealing performance.

[0420] <Third Implementation Method>

[0421] [Preparation of compositions for use in making sealing material layers]

[0422] Thermoplastic elastomers, tackifiers, and softeners were mixed with the formulations shown in Table 3-1 and stirred while heating to prepare compositions for various sealing material layers (compositions I to VI).

[0423] [Table 3-1]

[0424] [Example 3-1]

[0425] The composition shown in Composition I of Table 3-1 was applied to the release liner (single-sided treated paper) to form a sealing material layer. Specifically, while heating the composition to 150°C, a hot melt coating machine was used to apply the sealing material layer to the release liner (single-sided treated paper) to achieve the thickness shown in Table 3-2.

[0426] Next, the separately prepared release liner (single-sided treated PE) is bonded to the sealing material layer to manufacture a sealing sheet for pneumatic tires (hereinafter referred to as a sealing sheet).

[0427] It should be noted that the manufactured sealing strip for pneumatic tires is strip-shaped, with dry edges on both sides in the width direction. That is, the sealing material layer and the release liner are configured such that the edge of the release liner protrudes outward by the length (dry edge width) shown in Table 3-1 beyond the edge of the sealing material layer.

[0428] [Examples 3-2 to 3-6, 3-10 to 3-12]

[0429] Except for changing the combination or structure shown in Table 3-2 or Table 3-3, the sealing sheets of each embodiment were manufactured in the same manner as in Example 1.

[0430] [Examples 3-7 to 3-9]

[0431] Except for changing the composition or structure shown in Table 3-2, the sealing sheets of each embodiment were manufactured in the same manner as in Example 1. However, instead of the release liner (single-sided treated PE), the substrate layer with the release film was used, and this substrate layer was bonded to the sealing material layer, and then the release film was removed. It should be noted that the substrate layer is formed with the same shape and size as the release liner, and they overlap each other. The dry edges are provided such that the two end edges of the release liner and the substrate layer protrude outwards from the two end edges of the sealing material layer by a predetermined length in the width direction.

[0432] [Comparative Examples]

[0433] Except for changing the combination or structure shown in Table 3-3, the sealing sheets of each embodiment were manufactured in the same manner as in Example 1.

[0434] <Physical Property Determination>

[0435] For the sealing sheets manufactured as described above, the properties of the sealing material layer and the properties of the adhesive tape with the substrate layer, which is a laminate of the sealing material layer and the substrate layer, were measured. Specifically, the storage modulus, tensile modulus, elongation at break, and tensile stress relaxation rate at various temperatures were measured according to the methods described above. The results are shown in Tables 3-2 and 3-3, respectively.

[0436] [Table 3-2]

[0437] [Table 3-3]

[0438] <Adhesion>

[0439] The adhesive strength of the sealing material layers in each embodiment was measured at various temperatures according to the method described above. A tubeless tire (Formula Pro RBCC 700 × 25C) was used as the bonded object. It should be noted that the adhesive strength of the sealing material layers was measured at 60°C after being stored at 100°C for 30 days (after high-temperature storage). The results are shown in Tables 3-2 and 3-3, respectively.

[0440] [Amount of the sealing material layer protruding after heating]

[0441] A sealant layer was cut into squares with sides of 1 cm and sandwiched between two release liner gaskets. It was then further sandwiched between 3 mm thick SUS304 sheets. A load of 200 g was applied from both sides of the two SUS304 sheets, and the sheets were left to stand at 50°C for 3 days. The protrusion length of the sealant layer from its original 1 cm square was then measured. The results are shown in Tables 3-2 and 3-3.

[0442] [Thickness retention rate of the sealing material layer after heating]

[0443] The thickness of the sealing material layer was measured as described above when the protrusion was measured. The thickness of the sealing material layer after standing (thickness retention rate) was then expressed as a percentage relative to the thickness of the sealing material layer before standing for 3 days at 50°C. For example, the thickness retention rate is 100% if the thickness remains unchanged. The results are shown in Tables 3-2 and 3-3, respectively.

[0444] [Roll shape retention]

[0445] Based on the evaluation results of the protrusion amount and thickness retention rate of the sealing material layer, the shape retention was determined according to the following evaluation criteria. The results are shown in Tables 3-2 and 3-3, respectively.

[0446] Good (○): Protrusion less than 2mm and thickness retention rate above 60%.

[0447] Defective (×): Protrusion exceeding 2mm or thickness retention less than 60%.

[0448] [Evaluation of Sealing Performance]

[0449] The sealing performance of a through-hole formed in a pneumatic tire was evaluated using either the sealing material layer of the sealing sheet in each example, or a substrate-layered tape that is a laminate of the sealing material layer and the substrate layer (hereinafter referred to as a test sheet), following the operating procedures. The sealing performance evaluation was carried out at room temperature (23°C).

[0450] (1) A test piece with a planar size of 30mm × 50mm was made, and then the sealing material layer of the test piece was attached to the inner surface of the tubeless tire. As a tubeless tire, the product name "IRCRoad Tire (Formula Pro Hookless Tubeless RBCC 700×25C (Model 190636, manufactured by Inoue Rubber Industry Co., Ltd.)" was used.

[0451] (2) The tubeless tire with the test piece attached as described above was mounted on the wheel (manufactured by SHIMANO, product name "WH-RS500", rim dimensions: width 20.8mm, height 24mm). It should be noted that the installation of the tubeless tire on the wheel was carried out without injecting sealant material into the inside of the tubeless tire.

[0452] (3) Inflate the tubeless tire with air until the specified pressure (95 psi (approximately 0.66 MPa)) is reached. Then, observe the pressure change over a certain period of time (approximately one day) and determine the leakage rate V1 (psi / min) of the reference (Ref). That is, determine the leakage rate when no through-hole is formed in the tubeless tire. It should be noted that the pressure is measured by installing a pressure gauge on the valve of the wheel. The pressure measurement is performed with the tubeless tire and wheel as a single unit in a static state. The following pressure measurements are also performed in the same manner.

[0453] (4) Inject air back into the tubeless tire until the specified pressure (95 psi (approximately 0.66 MPa)) is reached, and then insert a 2.1 mm thick (1.2 mm diameter) needle into the area where the test piece is attached to the tire to a depth of 20 mm. Then, remove the needle from the tubeless tire to create a through hole.

[0454] (5) The observation starting point (0 min) is the time when the needle is pulled out and a through hole is formed. The pressure change is observed over a certain period of time (approximately 5 minutes), and the leakage rate V2 (psi / min) after the through hole is formed is calculated. Then, the difference between the leakage rate V2 and the leakage rate V1 (V2-V1) (leakage rate V3) is calculated. The closer the leakage rate V3 is to 0, the better the sealing effect. The sealing performance was then evaluated according to the following evaluation criteria. The evaluation results of the sealing performance at the specified temperature are shown in Tables 3-2 and 3-3, respectively.

[0455] Good (○): 0 ≤ V3 ≤ 1.0

[0456] Defective (×): 1.0 < V3

[0457] [Adhesion to the tire's surface curvature (curves on the tire's surface)]

[0458] The sealing material layer was cut to a width of 35 mm and a length of 100 mm. This sealing material layer was then bonded to the inner surface of the tubeless tire by applying a load of 5 kg three times. It should be noted that, without a substrate layer, the load was applied to the sealing material layer (located between the release liner and the tire) through the release liner. Conversely, with a substrate layer, the load was applied to the sealing material layer (located between the substrate layer and the tire) through the substrate layer. The evaluation was conducted according to the following evaluation criteria. The results are shown in Tables 3-2 and 3-3, respectively. It should be noted that in Example 3-12, the release liner was hard, thus reducing workability during bonding and resulting in poor results; however, the adhesiveness of the sealing material layer itself was the same as in Example 3-11.

[0459] Good (〇): The area of ​​the tire peeling off and lifting from the curved surface is less than 50%; Slightly undesirable (△): The area ratio of the raised area is less than 50%, but the area on one side of the sealing material layer sample in one direction of the face is peeled off and raised; Defective (×): The area of ​​the tire that peels off and lifts off the surface is more than 50%.

[0460] [Tire recyclability]

[0461] The sealing material layer was cut to a width of 10 mm and a length of 100 mm. This sealing material layer was pressed onto the inner surface of the tubeless tire and then left to stand at 100°C for 30 days. The sealing material layer was then peeled off at a peel angle of 180 degrees and a peeling speed of 300 mm / min. It should be noted that, without a substrate layer attached to the sealing material layer, a 25 μm thick PET resin film was adhered to it as a backing before peeling. After peeling, the extent to which a portion of the sealing material layer remained on the tire surface was visually confirmed. The results are shown in Tables 3-2 and 3-3.

[0462] 〇 (Good): The residue of sealing material is less than 50%; × (Poor): More than 50% of the sealing material remains. According to the results in Tables 3-2 and 3-3, the sealing material layer of the third embodiment exhibits good sealing performance and recyclability. In contrast, the sealing material layer of the comparative example exhibits poor sealing performance and recyclability.

[0463] Industrial practicality

[0464] The sealing sheet for pneumatic tires of the present invention is suitable, for example, for preventing tire blowouts by being adhered to the inner surface of tubeless tires such as bicycles.

[0465] Label Explanation

[0466] 1: Sealing sheets for pneumatic tires, 11: Sealing material layer, 12: Substrate layer, 10: Adhesive tape with substrate layer, 20: Release liner.

Claims

1. A sealing sheet for a pneumatic tire, wherein, The sealing sheet for the pneumatic tire has at least a layer of sealing material to be adhered to the inner surface of the pneumatic tire. The energy storage modulus of the sealing material layer at 23°C is below 350 kPa, and after 30 days at 100°C, the energy storage modulus of the sealing material layer at 60°C is above 10 kPa. The maximum stress of the sealing material layer at 23°C is greater than 1.0 N / 10 mm.

2. The sealing sheet for a pneumatic tire according to claim 1, wherein, The tensile stress relaxation rate of the sealing material layer at 23°C is less than 85%.

3. The sealing sheet for a pneumatic tire according to claim 1 or 2, wherein, The adhesive strength of the sealing material layer to the tire at 23°C is greater than 0.5N / 10mm, and the adhesive strength of the sealing material layer to the tire at 23°C after 30 days at 100°C is less than 10.0N / 10mm.

4. The sealing sheet for a pneumatic tire according to claim 1 or 2, wherein, The elongation at break of the sealing material layer at 23°C is over 100%.

5. The sealing sheet for a pneumatic tire according to claim 1 or 2, wherein, The sealing material layer contains an elastomer.

6. The sealing sheet for a pneumatic tire according to claim 1 or 2, wherein, The sealing sheet for the pneumatic tire also includes a substrate layer that supports the sealing material layer. The substrate layer is stacked on one side of the sealing material layer, or disposed inside the sealing material layer.

7. The sealing sheet for a pneumatic tire according to claim 6, wherein, The maximum stress of the adhesive tape with the sealing material layer and the substrate layer at 23°C is 10 N / 10 mm or more.

8. The sealing sheet for a pneumatic tire according to claim 7, wherein, The tensile modulus of the tape with the substrate layer at 23°C is below 500 MPa.

9. The sealing sheet for a pneumatic tire according to claim 6, wherein, The elongation at break of the tape having the sealing material layer and the substrate layer at 23°C is 100% or more.

10. The sealing sheet for a pneumatic tire according to claim 6, wherein, The tensile stress relaxation rate of the adhesive tape with the sealing material layer and the substrate layer at 23°C is less than 85%.

11. The sealing sheet for a pneumatic tire according to claim 6, wherein, The substrate layer is composed of any one of fiber sheets, foam sheets, solid sheets, or laminated sheets obtained by stacking two or more of these sheets.

12. The sealing sheet for a pneumatic tire according to claim 6, wherein, The sealing sheet for the pneumatic tire is in the form of a strip and is in a wound state. The adhesive tape having the sealing material layer and the substrate layer has a thickness of less than 3 mm, a width of more than 20 mm, and a length of more than 50 cm. The thickness of the sealing material layer is less than 2 mm.

13. The sealing sheet for a pneumatic tire according to claim 1 or 2, wherein, The pneumatic tire is a tubeless tire or a quasi-tubeless tire.

14. The sealing sheet for a pneumatic tire according to claim 1 or 2, wherein, The pneumatic tire is a bicycle tire or a motorcycle tire.

15. A sealing sheet for a pneumatic tire, wherein, The sealing sheet for the pneumatic tire has at least a layer of sealing material to be adhered to the inner surface of the pneumatic tire. The energy storage modulus of the sealing material layer is less than 500 kPa at -5°C and greater than 10 kPa at 60°C.

16. The sealing sheet for a pneumatic tire according to claim 15, wherein, The elongation at break of the sealing material layer at 23°C is over 100%.

17. The sealing sheet for a pneumatic tire according to claim 15 or 16, wherein, The tensile stress relaxation rate of the sealing material layer at 23°C is less than 85%.

18. The sealing sheet for a pneumatic tire according to claim 15 or 16, wherein, The mass of the sealing material layer per unit area is 1800 g / m². 2 the following.

19. The sealing sheet for a pneumatic tire according to claim 15 or 16, wherein, The sealing material layer contains an elastomer.

20. The sealing sheet for a pneumatic tire according to claim 15 or 16, wherein, The sealing sheet for the pneumatic tire also includes a substrate layer that supports the sealing material layer. The substrate layer is stacked on one side of the sealing material layer, or disposed inside the sealing material layer.

21. The sealing sheet for a pneumatic tire according to claim 15 or 16, wherein, The sealing material layer has an adhesion force of 1.0 N / 10 mm or more to the tire at -5°C, and an adhesion force of 0.1 N / 10 mm or more to the tire at 60°C.

22. The sealing sheet for a pneumatic tire according to claim 20, wherein, The tensile modulus of the tape with the sealing material layer and the substrate layer at 23°C is less than 500 MPa.

23. The sealing sheet for a pneumatic tire according to claim 20, wherein, The elongation at break of the tape having the sealing material layer and the substrate layer at 23°C is 100% or more.

24. The sealing sheet for a pneumatic tire according to claim 20, wherein, The tensile stress relaxation rate of the adhesive tape with the sealing material layer and the substrate layer at 23°C is less than 85%.

25. The sealing sheet for a pneumatic tire according to claim 20, wherein, The substrate layer is composed of any one of fiber sheets, foam sheets, solid sheets, or laminated sheets obtained by stacking two or more of these sheets.

26. The sealing sheet for a pneumatic tire according to claim 15 or 16, wherein, At least one side of the sealing material layer also has a release liner. The tensile modulus of the peeling liner at 23°C is below 4000 MPa.

27. The sealing sheet for a pneumatic tire according to claim 20, wherein, The sealing sheet for the pneumatic tire is in the form of a strip and is in a wound state. The adhesive tape having the sealing material layer and the substrate layer has a thickness of less than 3 mm, a width of more than 20 mm, and a length of more than 50 cm. The thickness of the sealing material layer is less than 2 mm.

28. The sealing sheet for a pneumatic tire according to claim 15 or 16, wherein, The pneumatic tire is a tubeless tire or a quasi-tubeless tire.

29. The sealing sheet for a pneumatic tire according to claim 15 or 16, wherein, The pneumatic tire is a bicycle tire or a motorcycle tire.

30. A sealing sheet for a pneumatic tire, wherein, The sealing sheet for the pneumatic tire has at least a layer of sealing material to be adhered to the inner surface of the pneumatic tire. When the thickness of the sealing material layer is set to T [mm] and the storage modulus of the sealing material layer at 60°C is set to E [kPa], T and E satisfy the following relationship: [(1000×T) / E]<50.

31. The sealing sheet for a pneumatic tire according to claim 30, wherein, The elongation at break of the sealing material layer at 23°C is over 100%.

32. The sealing sheet for a pneumatic tire according to claim 30 or 31, wherein, The tensile stress relaxation rate of the sealing material layer at 23°C is less than 85%.

33. The sealing sheet for a pneumatic tire according to claim 30 or 31, wherein, The sealing material layer contains an elastomer.

34. The sealing sheet for a pneumatic tire according to claim 30 or 31, wherein, The sealing sheet for the pneumatic tire also includes a substrate layer that supports the sealing material layer. The substrate layer is stacked on one side of the sealing material layer, or disposed inside the sealing material layer.

35. The sealing sheet for a pneumatic tire according to claim 30 or 31, wherein, The sealing material layer has an adhesion force of 1.0 N / 10 mm or more to the tire at -5°C.

36. The sealing sheet for a pneumatic tire according to claim 34, wherein, The elongation at break of the tape having the sealing material layer and the substrate layer at 23°C is 100% or more.

37. The sealing sheet for a pneumatic tire according to claim 34, wherein, The tensile modulus of the tape with the sealing material layer and the substrate layer at 23°C is less than 500 MPa.

38. The sealing sheet for a pneumatic tire according to claim 34, wherein, The tensile stress relaxation rate of the adhesive tape with the sealing material layer and the substrate layer at 23°C is less than 85%.

39. The sealing sheet for a pneumatic tire according to claim 34, wherein, The substrate layer is composed of any one of fiber sheets, foam sheets, solid sheets, or laminated sheets obtained by stacking two or more of these sheets.

40. The sealing sheet for a pneumatic tire according to claim 30 or 31, wherein, The total light transmittance of the sealing sheet for the pneumatic tire is above 75%.

41. The sealing sheet for a pneumatic tire according to claim 30 or 31, wherein, At least one side of the sealing material layer also has a release liner. The tensile modulus of the peeling liner at 23°C is below 4000 MPa.

42. The sealing sheet for a pneumatic tire according to claim 34, wherein, The sealing sheet for the pneumatic tire is in the form of a strip and is in a wound state. The adhesive tape having the sealing material layer and the substrate layer has a thickness of less than 3 mm, a width of more than 20 mm, and a length of more than 50 cm. The thickness of the sealing material layer is less than 2 mm.

43. The sealing sheet for a pneumatic tire according to claim 30 or 31, wherein, The sealing strip for the pneumatic tire is in the form of a strip. At least one side of the sealing material layer also has a release liner. On at least one side of the width direction of the sealing sheet for the pneumatic tire, the edge of the release liner protrudes more than 1 mm beyond the edge of the sealing material layer.

44. The sealing sheet for a pneumatic tire according to claim 30 or 31, wherein, The sealing strip for the pneumatic tire is in the form of a strip. The sealing sheet for the pneumatic tire also includes a substrate layer disposed on one side of the sealing material layer and a release liner disposed on the other side of the sealing material layer. On at least one side of the width direction of the sealing sheet for the pneumatic tire, the edge of the release liner protrudes more than 1 mm beyond the edge of the sealing material layer or the substrate layer.

45. The sealing sheet for a pneumatic tire according to claim 30 or 31, wherein, The pneumatic tire is a tubeless tire or a quasi-tubeless tire.

46. ​​The sealing sheet for a pneumatic tire according to claim 30 or 31, wherein, The pneumatic tire is a bicycle tire or a motorcycle tire.

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