Laminate, method for manufacturing laminate, and tire

Abstract

The present application provides a laminated body of vulcanized rubbers having excellent adhesion stability, a manufacturing method of the laminated body, and a tire including the laminated body. The laminated body of the present application is a laminated body including, in order, a first layer made of a vulcanized rubber, an adhesion layer made of a cured product of a cyanoacrylate-based adhesive, a second layer made of a vulcanized rubber, and a sensor layer including a sensor, the cured product having a softening point of 71°C or higher.

Description

Technical Field

[0001] This invention relates to laminates, methods for manufacturing laminates, and tires. Background Technology

[0002] Previously, laminates obtained by bonding vulcanized rubbers together with cyanoacrylate-based adhesives were known (e.g., Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2020 / 022160 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In Patent Document 1, the tire liner and the sensor unit are bonded together using a cyanoacrylate-based adhesive (instant adhesive). In this case, intermittent loads are applied between the liner and the sensor unit by means of tire rotation, etc.

[0008] The inventors studied laminates obtained by bonding vulcanized rubbers together with cyanoacrylate-based adhesives, and the results showed that under intermittent loads as described above, the vulcanized rubbers sometimes peeled off. That is, it was found that the adhesive stability was sometimes insufficient.

[0009] Therefore, in view of the above-mentioned actual situation, the present invention aims to provide a laminate of vulcanized rubbers with excellent adhesive stability, a method for manufacturing the laminate, and a tire comprising the laminate.

[0010] Methods for solving problems

[0011] In order to solve the above-mentioned problems, the inventors conducted in-depth research and found that by using a substance with a softening point within a specific range after curing as a cyanoacrylate adhesive, the bonding stability was critically improved, thus completing the present invention.

[0012] That is, the inventors have discovered that the above-mentioned problems can be solved by the following configuration.

[0013] (1) A laminate comprising, in sequence, a first layer made of vulcanized rubber, an adhesive layer made of a cured product of a cyanoacrylate adhesive, a second layer made of vulcanized rubber, and a sensor layer containing a sensor, wherein the softening point of the cured product is 71°C or higher.

[0014] (2) According to the laminate described in (1) above, the cyanoacrylate in the cyanoacrylate adhesive comprises alkyl cyanoacrylate.

[0015] (3) According to the laminate described in (1) or (2) above, the vulcanized rubber in the first layer is butyl rubber or a vulcanized halogenated butyl rubber.

[0016] (4) The laminate according to any one of (1) to (3) above, wherein the vulcanized rubber in the second layer is a vulcanizate selected from at least one of natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, halogenated butyl rubber, chloroprene rubber and nitrile rubber.

[0017] (5) A method for manufacturing a laminate, wherein the laminate as described in any one of (1) to (4) is obtained by bonding the first layer to the second layer holding the sensor layer using the cyanoacrylate adhesive.

[0018] (6) According to the manufacturing method of the laminate described in (6) above, before bonding the first layer and the second layer using the cyanoacrylate adhesive, trichloroisocyanuric acid is coated on the surface of the first layer or the second layer.

[0019] (7) A tire comprising any one of the laminates described in (1) to (4) above.

[0020] The effects of the invention

[0021] As shown below, according to the present invention, a laminate of vulcanized rubbers with excellent adhesive stability, a method for manufacturing the laminate, and a tire comprising the laminate can be provided. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view of one embodiment of the laminate of the present invention.

[0023] Figure 2 This is a cross-sectional view of one embodiment of the tire of the present invention.

[0024] Figure 3 for Figure 1 A magnified view of a portion of it. Detailed Implementation

[0025] The following describes the laminate of the present invention, the method for manufacturing the laminate of the present invention, and the tire of the present invention.

[0026] In addition, the numerical range indicated by “~” in this specification refers to the range of values ​​recorded before and after “~” as the lower and upper limits.

[0027] Each ingredient can be used alone or in combination with two or more ingredients. Here, when two or more ingredients are used together, the so-called content of an ingredient, unless otherwise specified, refers to the total content.

[0028] [Laminated structure]

[0029] The laminate of the present invention is a laminate comprising, in sequence, a first layer made of vulcanized rubber, an adhesive layer made of a cured product of a cyanoacrylate adhesive, a second layer made of vulcanized rubber, and a sensor layer containing a sensor, wherein the softening point of the cured product is 71°C or higher.

[0030] [Explanation of the use of the attached drawings]

[0031] First, the laminate of the present invention will be described using the accompanying drawings.

[0032] Figure 1 This is a cross-sectional view of one embodiment of the laminate of the present invention.

[0033] Figure 1 The stack 100 shown is a stack comprising, in sequence, a first layer 40 made of vulcanized rubber, an adhesive layer 50 made of a cured cyanoacrylate adhesive (softening point above 71°C), a second layer 60 made of vulcanized rubber, and a sensor layer 70 containing a sensor.

[0034] The layers constituting the stack of the present invention will be described below.

[0035] [Level 1]

[0036] As described above, the laminate of the present invention comprises a first layer made of vulcanized rubber.

[0037] There are no particular restrictions on the first layer being made of vulcanized rubber, as long as the first layer is made of vulcanized rubber (cured rubber).

[0038] There are no particular limitations on the aforementioned vulcanized rubbers. Specific examples include natural rubber (NR), butadiene rubber (BR), aromatic vinyl compound / conjugated diene rubber, isoprene rubber (IR), nitrile rubber (NBR), butyl rubber (IIR), halogenated butyl rubber (e.g., brominated butyl rubber (BIIR), chlorinated butyl rubber (CIIR)), and chloroprene rubber (CR) vulcanizates. Examples of the aforementioned aromatic vinyl compound-conjugated diene copolymer rubbers include styrene-butadiene rubber (SBR) and styrene / isoprene rubber.

[0039] Based on the superior performance of the present invention, the above-mentioned vulcanized rubber is preferably a vulcanizate of butyl rubber or halogenated butyl rubber.

[0040] [Adhesive layer]

[0041] As described above, the laminate of the present invention comprises an adhesive layer made of a cured product of a cyanoacrylate-based adhesive. Here, the softening point of the cured product is 71°C or higher.

[0042] <Cyanoacrylate adhesives>

[0043] Cyanoacrylate adhesives are adhesives containing cyanoacrylate.

[0044] There are no special restrictions as long as the cyanoacrylates mentioned above are esters of cyanoacrylate.

[0045] For the sake of superior performance of the present invention, the above-mentioned cyanoacrylate is preferably an alkyl ester of cyanoacrylate (alkyl cyanoacrylate).

[0046] The number of carbon atoms in the alkyl group of the above-mentioned cyanoacrylate is not particularly limited, but for the sake of superior performance of the present invention, it is preferably 1 to 5, more preferably 1 to 3, further preferably 1 to 2, and particularly preferably 2. That is, for the sake of superior performance of the present invention, the alkyl cyanoacrylate is preferably methyl cyanoacrylate or ethyl cyanoacrylate, more preferably ethyl cyanoacrylate.

[0047] Regarding the cyanoacrylate content in the cyanoacrylate-based adhesive, based on the superior effect of the present invention, it is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. There is no particular limit to the upper limit of the cyanoacrylate content in the cyanoacrylate-based adhesive, which is 100% by mass.

[0048] <Cured product>

[0049] Cyanoacrylate adhesives typically cure (polymerize) by reacting with moisture in the air.

[0050] (Softening point)

[0051] The softening point of the cured cyanoacrylate adhesive is above 71°C.

[0052] For the sake of superior performance of the present invention, the softening point of the cured product is preferably 80°C or higher, more preferably 90°C or higher, even more preferably 100°C or higher, particularly preferably 110°C or higher, and most preferably 120°C or higher. There is no particular limitation on the upper limit of the softening point of the cured product, but for the sake of superior performance of the present invention, it is preferably 200°C or lower, more preferably 190°C or lower, even more preferably 180°C or lower, even more preferably 170°C or lower, particularly preferably 160°C or lower, and most preferably 150°C or lower.

[0053] In addition, the softening point mentioned above is the Vicat softening temperature measured according to JIS K7206.

[0054] There are no particular limitations on the method for making the softening point of the above-mentioned cured material within the desired range. For example, methods such as adjusting the number of carbon atoms of the alkyl group in the cyanoacrylate can be used.

[0055] [Level 2]

[0056] As described above, the laminate of the present invention comprises a second layer made of vulcanized rubber.

[0057] There are no particular restrictions on the second layer, which is made of vulcanized rubber, as long as it is made of vulcanized rubber (cured rubber).

[0058] The specific examples of the vulcanized rubber described above are the same as those in the first layer. However, for the sake of superior performance of the present invention, it is preferable to use a vulcanizate selected from at least one of natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, halogenated butyl rubber, chloroprene rubber, and nitrile rubber. More preferably, it is a vulcanizate of a rubber containing at least natural rubber. Even more preferably, it is a vulcanizate of a mixture of natural rubber and butadiene rubber. When the vulcanized rubber is a vulcanizate of a rubber containing natural rubber, for the sake of superior performance of the present invention, the content of natural rubber is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more.

[0059] [Sensor layer]

[0060] As described above, the stack of the present invention includes a sensor layer containing a sensor (detector).

[0061] The aforementioned sensor layer preferably includes mechanical components coated with resin or metal.

[0062] The aforementioned sensor layer preferably includes a housing and electronic components. The housing preferably has a hollow structure, with the electronic components housed inside.

[0063] The aforementioned electronic components are preferably configured to include sensors, transmitters, receivers, control circuits, and batteries for acquiring information.

[0064] When the laminate of the present invention is used in a tire, specific examples of the aforementioned sensors include a temperature sensor for measuring internal temperature, a pressure sensor for measuring internal pressure, and a sensor for detecting the amount of wear on the tread.

[0065] [Manufacturing Method]

[0066] There are no particular limitations on the method for manufacturing the laminate of the present invention. For example, a method in which the first layer and the second layer are bonded together using the cyanoacrylate-based adhesive described above can be used. Here, the sensor layer is retained in the second layer.

[0067] In the above method, for the sake of superior performance of the present invention, it is preferable to coat the surface of the first or second layer with trichloroisocyanuric acid (chlorinating agent) before bonding the first layer and the second layer using a cyanoacrylate-based adhesive. Trichloroisocyanuric acid has the effect of improving adhesion.

[0068] There are no particular limitations on the method of holding the sensor layer in the second layer. Examples include bonding the second layer to the sensor layer with an adhesive, using a vulcanized rubber container as the second layer and housing the sensor layer (e.g., electronic components containing the sensor) therein, etc.

[0069] [tire]

[0070] The tire of the present invention is a tire comprising the laminate of the present invention described above.

[0071] The tire of the present invention will now be described using the accompanying drawings.

[0072] Figure 2 This is a cross-sectional view of one embodiment of the tire (pneumatic tire) of the present invention.

[0073] Figure 2 The tire 200 shown has a tread portion 12, a shoulder portion 14, a sidewall portion 16, and a bead portion 18 as its main components.

[0074] Additionally, in the following explanation, such as in Figure 2 As indicated by the arrows, the tire width direction refers to the direction parallel to the tire's axis of rotation (not shown), while the tire radial direction refers to the direction orthogonal to the axis of rotation. Furthermore, the tire circumferential direction refers to the direction of rotation about the axis of rotation as its center.

[0075] Furthermore, the so-called inner side of the tire refers to the radial side of the tire. Figure 2 The underside of the tire, that is, the inner surface of the tire facing the cavity area R that applies a specified internal pressure to the tire; the outer side of the tire refers to... Figure 2 The upper side of the tire, that is, the outer surface of the tire that is visually recognizable to the user, opposite to the inner circumference of the tire. Figure 2 The symbol CL stands for tire equatorial plane. The tire equatorial plane CL is a plane that is orthogonal to the axis of rotation of tire 200 and passes through the center of the tire width of tire 200.

[0076] Tire 200 mainly comprises a carcass layer 20, a belt layer 22, a belt auxiliary reinforcement layer 24, a bead core 28, a bead filler 30, a tread rubber layer 32 constituting the tread portion 12, a sidewall rubber layer 34 constituting the sidewall portion 16, a rim cushioning rubber layer 36, and an inner liner layer 42 disposed on the inner circumferential surface of the tire. The inner liner layer 42 is made of vulcanized rubber.

[0077] The bead portion 18 includes a pair of left and right bead cores 28 that function to fix the tire 200 to the wheel by folding back the carcass layer 20, and a bead filler 30 that is connected to the bead cores 28. Therefore, the bead cores 28 and the bead filler 30 are sandwiched between the main body portion 20a and the folded-back portion 20b of the carcass layer 20.

[0078] The carcass layer 20 extends along the tire width direction from the portion corresponding to the tread portion 12, through the portions corresponding to the shoulder portion 14 and the sidewall portion 16, to the bead portion 18 to form the skeleton of the tire 200.

[0079] The carcass layer 20 is composed of reinforcing cords arranged in a rubber coating. The carcass layer 20 folds back from the inside to the outside of the tire around a pair of bead cores 28, forming an end portion 20e in the area of ​​the sidewall portion 16. It is formed by a main body portion 20a bounded by the bead cores 28 and a folded-back portion 20b. That is, in this embodiment, one carcass layer 20 is mounted between the pair of bead portions 18. The number of carcass layers 20 is not limited to one; multiple layers can be used depending on the structure and application.

[0080] Furthermore, the carcass layer 20 can be composed of a single sheet or multiple sheets. In the case of multiple sheets, the carcass layer 20 has a joint (connection).

[0081] The organic fiber cords of the carcass layer 20 are formed, for example, from PET (polyethylene terephthalate), polyethylene naphthalate (PEN), rayon, or nylon.

[0082] The cord coating rubber of the carcass layer 20 is preferably selected from one or more rubbers selected from natural rubber (NR), styrene-butadiene rubber (SBR), butadiene rubber (BR), and isoprene rubber (IR).

[0083] A vulcanized rubber container 62 is bonded to the inner liner 42 of the tire 200 via an adhesive layer 52. The adhesive layer 52 is a cured product of a cyanoacrylate adhesive (softening point above 71°C). A sensor 72 is housed within the vulcanized rubber container 62.

[0084] Figure 3 for Figure 1 A magnified view of a portion of it.

[0085] like Figures 2-3 As shown, the tire 200 comprises a laminate 110 having a first layer (inner liner 42) made of vulcanized rubber, an adhesive layer 52 made of a cured cyanoacrylate adhesive (softening point above 71°C), a second layer made of vulcanized rubber (part of the vulcanized rubber container 62), and a sensor layer (sensor 72) containing a sensor.

[0086] The tires mentioned above are preferably pneumatic tires, which can be filled with inactive gases such as air and nitrogen, as well as other gases.

[0087] Example

[0088] The present invention will be further described in detail below through examples, but the present invention is not limited thereto.

[0089] [Laminated body]

[0090] <Manufacturing of Laminated Structures>

[0091] Prepare the vulcanized rubber listed in the first column of Table 1 and the vulcanized rubber listed in the second column of Table 1. In addition, a sensor layer containing the sensor is maintained in the vulcanized rubber (second layer).

[0092] The prepared vulcanized rubber (first layer) and vulcanized rubber (second layer) were bonded together using the adhesives listed in the adhesive column of Table 1.

[0093] This operation yields a stack consisting of a first layer made of vulcanized rubber, an adhesive layer made of cured adhesive, a second layer made of vulcanized rubber, and a sensor layer containing a sensor.

[0094] <90° Peel Test>

[0095] Regarding the obtained laminates, the second layer was peeled off from the first layer by a 90° peel test, and the damage state of the peel surface was visually confirmed.

[0096] The results are shown in Table 1. MF indicates material failure of the vulcanized rubber, and CF indicates coagulation failure of the adhesive layer. If it is MF, then the adhesion can be said to be excellent.

[0097] 〔tire〕

[0098] <Tire Manufacturing>

[0099] A tire having an inner liner made of vulcanized rubber as described in the first column of Table 1 is prepared. Furthermore, a container made of vulcanized rubber (vulcanized rubber container) as described in the second column of Table 1 is prepared. Additionally, an electronic component containing a sensor is housed within the vulcanized rubber container.

[0100] The vulcanized rubber container was bonded to the inner lining of the prepared tire by applying the adhesive listed in the adhesive column of Table 1.

[0101] This was obtained through this operation. Figures 2-3 The tire shown comprises a laminate consisting of a first layer (inner liner) made of vulcanized rubber, an adhesive layer made of cured adhesive, a second layer (part of a vulcanized rubber container) made of vulcanized rubber, and a sensor layer (electronic components containing the sensor) containing a sensor.

[0102] <Tire Driving Test>

[0103] The obtained tires were mounted on wheels with rim sizes of 21×9.5J and subjected to driving tests using a drum tester (air pressure 120 kPa, relative to 102% of the maximum load, driving speed 81 km / h, driving distance 10,000 km). The condition of the vulcanized rubber container after the driving test was visually confirmed, and the adhesion stability was evaluated according to the following criteria.

[0104] The results are shown in Table 1. From the viewpoint of adhesive stability, ○ or △ is preferred, and ○ is more preferred.

[0105] ○: Almost no delamination is observed between the inner lining and the vulcanized rubber container.

[0106] △: Delamination was observed between several inner lining layers and the vulcanized rubber container.

[0107] ×: Significant delamination was observed between the inner liner and the vulcanized rubber container.

[0108]

[0109] <Vulcanized Rubber>

[0110] The vulcanized rubbers listed in the columns for Layer 1 and Layer 2 in Table 1 are as follows: • BIIR: Brominated Butyl Rubber (Vulcanizate)

[0111] • IIR: Butyl rubber (vulcanizate)

[0112] • NR / BR: Natural rubber / Butadiene rubber = 95 / 5 (mass ratio) (vulcanizate)

[0113] • NR / SBR: Natural rubber / Styrene-butadiene rubber = 40 / 60 (mass ratio) (vulcanizate)

[0114] •CR: Chloroprene rubber (vulcanizate)

[0115] • NBR: Nitrile rubber (vulcanizate)

[0116] <Adhesive>

[0117] The adhesives listed in Table 1 are as follows.

[0118] • Adhesive 1: Shannon SR, cyanoacrylate adhesive (ethyl cyanoacrylate), manufactured by High Pressure Gas Industry Co., Ltd., softening point of cured product: 145℃

[0119] • Adhesive 2: Alonalfaextra 2000, a cyanoacrylate adhesive (ethyl cyanoacrylate), manufactured by Toa Synthetic Co., Ltd., with a softening point of 145°C after curing.

[0120] • Adhesive 3: Alonalfa 602PF, a cyanoacrylate adhesive, manufactured by Toa Synthetic Co., Ltd., with a softening point of 110°C after curing.

[0121] • Adhesive 4: Alonalfa 802, a cyanoacrylate adhesive, manufactured by Toa Synthetic Co., Ltd., with a softening point of the cured product of 60°C.

[0122] • Adhesive 5: Alonalfa 101, a cyanoacrylate adhesive (methyl cyanoacrylate), manufactured by Toa Synthetic Co., Ltd., with a softening point of 165°C after curing.

[0123] Additionally, in Table 1, the softening point column shows the softening point [°C] of the cured adhesive.

[0124] As shown in Table 1, compared with Comparative Example 1, which used a cyanoacrylate adhesive with a softening point of less than 71°C after curing, Examples 1-9, which used a cyanoacrylate adhesive with a softening point of 71°C or higher after curing, exhibited excellent adhesive stability. Among them, Examples 1-2 and Examples 4-8, which used cyanoacrylate adhesives with a softening point of 120-160°C after curing, showed even better adhesive stability.

[0125] Explanation of symbols

[0126] 12th pregnancy face

[0127] 14. Tire shoulder

[0128] 16. Sidewall

[0129] 18. Bead section

[0130] 20 layers of the fetal body

[0131] 20a carcass layer 20 main body

[0132] 20b carcass layer 20 fold back

[0133] The end of the 20e carcass layer 20

[0134] 22 Belt Layers

[0135] 22a Inner Belt Layer

[0136] 22b Outer band layer

[0137] 22e end of belt layer 22

[0138] 24 Belt-assisted reinforcement layer

[0139] 28 Bead core

[0140] 30 Bead filler

[0141] 32 Tread rubber layers

[0142] 34 Sidewall rubber layer

[0143] 36. Rim buffer rubber layer

[0144] 40 The first layer is made of vulcanized rubber.

[0145] 42 Inner Liner

[0146] 50, 52 Adhesive layers

[0147] 60 Second layer made of vulcanized rubber

[0148] 62. Containers made of vulcanized rubber

[0149] 70 Sensor layer containing sensors

[0150] 72 Electronic components containing sensors

[0151] 100, 110 laminated bodies

[0152] 200 tires (pneumatic tires).

Claims

1. A laminate comprising, sequentially comprising, a first layer made of vulcanized rubber, an adhesive layer made of a cured product of a cyanoacrylate-based adhesive, a second layer made of vulcanized rubber, and a sensor layer comprising a sensor, wherein the cured product has a softening point of 120–160°C, and the vulcanized rubber in the second layer is a vulcanized compound of a mixture of natural rubber and butadiene rubber, wherein the content of the natural rubber in the vulcanized compound is 50% by mass or more.

2. The laminate according to claim 1, wherein the cyanoacrylate in the cyanoacrylate adhesive comprises an alkyl cyanoacrylate.

3. The laminate according to claim 1 or 2, wherein the vulcanized rubber in the first layer is butyl rubber or a vulcanizate of halogenated butyl rubber.

4. A method for manufacturing a laminated body, wherein, By bonding the first layer and the second layer, on which the sensor layer is held, using the cyanoacrylate adhesive, a laminate as described in any one of claims 1 to 3 is obtained.

5. In the method for manufacturing the laminate according to claim 4, before bonding the first layer and the second layer using the cyanoacrylate adhesive, trichloroisocyanuric acid is coated on the surface of the first layer or the second layer.

6. A tire comprising the laminate according to any one of claims 1 to 3.

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