Pneumatic tires and methods for their manufacture

Abstract

A method for manufacturing a pneumatic tire, the method comprising: attaching a sensor unit (20) to a tire inner surface (Ts), irradiating the tire inner surface (Ts) with a laser to remove a release agent, adjusting a thickness (g) of the release agent, determined by an electron microscope, at least in a mounting area (S) for the sensor unit (20) to 0.1 µm to 100 µm, and attaching the sensor unit (20) to the mounting area (S) for the sensor unit (20) via an adhesive layer (10), wherein the sensor unit (20), the adhesive layer (10) and a release agent layer (11) are layered on top of each other from an inner side in the tire radial direction.

Description

Technical field

[0001] The present invention relates to a pneumatic tire with a sensor unit that detects tire information and a method for its manufacture, and in particular to a pneumatic tire and a method for its manufacture which can provide improved adhesion between a tire inner surface and a sensor unit, while ensuring air retention properties by connecting the sensor unit to the tire inner surface in a state in which a release agent is applied to the tire inner surface. State of the art

[0002] To obtain information from inside the tire, such as internal pressure and temperature, various types of sensors are installed in a tire cavity (see, for example, patent specifications 1 and 2).

[0003] On the other hand, when vulcanizing a tire blank using a bellows, it is likely that the bellows will bond to an inner surface of the tire blank. Therefore, a release agent is applied to the inner surface of the tire blank to prevent this bonding. In such a case, attempting to bond and attach the sensor unit directly to the inner surface of the tire presents the problem of poor adhesion between the inner surface, to which the release agent is applied, and the sensor unit, resulting in the sensor unit easily peeling off.

[0004] In contrast, it has been proposed to apply a release agent to an inner surface of a tire blank, vulcanize the tire blank, and then grind the inner surface to remove the release agent (for example, patent document 3). However, such grinding has a problem, as it reduces the thickness of the inner liner and thus impairs the air retention properties. It has also been proposed to pre-bond a ply to an inner surface of a tire blank, apply a release agent to the inner surface of the tire blank while the ply is bonded, and then peel off the ply after vulcanization to remove the release agent (for example, patent document 4). However, this step of peeling off the ply after vulcanization impairs the air retention properties.Furthermore, it was suggested that the inner surface of the tire, where the release agent is applied, be cleaned. However, a problem with this technique is that the release agent cannot be sufficiently removed. List of literature on patent literature Patent document 1: JP 6272225 B Patent Document 2: JP 2016-505438 T Patent Document 3: JP 4410753 B Patent Document 4: JP 2015-107690 A Brief description of the invention: Technical problem

[0005] An object of the present invention is to provide a pneumatic tire and a method for its manufacture which can provide improved adhesion between a tire inner surface and a sensor unit, while simultaneously ensuring air retention properties by bonding the sensor unit to the tire inner surface in a state in which a release agent is applied to the tire inner surface. Solution to the problem

[0006] A pneumatic tire according to an embodiment of the present invention for achieving the above-described objective includes at least one sensor unit which is attached to an inner surface of the tire via an adhesive layer, and includes a sensor which detects tire information, and a thickness of a separating agent which is determined by an electron microscope is at least 0.1 µm to 100 µm in a mounting area for the sensor unit.

[0007] A method for manufacturing a pneumatic tire according to an embodiment of the present invention is a method for manufacturing a pneumatic tire, including vulcanizing a tire blank using a bellows enclosing a coating layer made of a release agent, wherein the method includes, when attaching a sensor unit to an inner surface of a tread section of a vulcanized pneumatic tire, adjusting a thickness of the release agent, determined by an electron microscope, to at least 0.1 µm to 100 µm in an attachment area for the sensor unit, and attaching the sensor unit to the attachment area for the sensor unit via an adhesive layer.

[0008] Furthermore, a method for manufacturing a pneumatic tire according to an embodiment of the present invention includes, when attaching a sensor unit to an inner surface of the tire, irradiating the inner surface of the tire with a laser to remove a release agent, adjusting the thickness of the release agent, which is determined by an electron microscope, to 0.1 µm to 100 µm at least in an attachment area for the sensor unit, and attaching the sensor unit to the attachment area for the sensor unit via an adhesive layer. Advantageous effects of the invention

[0009] In one embodiment of the present invention, the thickness of a release agent, determined by an electron microscope, is set to 0.1 µm to 100 µm, at least in one mounting area for a sensor unit, and the sensor unit is fixed in a state in which a trace amount of the release agent is applied to the inner surface of the tire. While the release agent inhibits the penetration of air from the inner surface of the tire and improves the air retention properties, sufficient adhesion between the inner surface of the tire and the sensor unit can thus be ensured.

[0010] In one embodiment of the present invention, the adhesive layer preferably has an adhesive strength in the range of 0.4 N / nm. 2 up to 100 N / nm 2Therefore, work to install the sensor unit can be carried out easily while maintaining good adhesion of the adhesive layer. The adhesion strength (tensile shear strength) of the adhesive layer complies with both JIS-K6850 and JIS-Z0237 and is the adhesion strength measured under standard conditions (23 °C, 50% RH).

[0011] In one embodiment of the present invention, the adhesive layer is preferably formed from a cyanoacrylate-based adhesive. Accordingly, the working time for installing the sensor unit can be reduced.

[0012] In one embodiment of the present invention, the sensor unit is preferably arranged inwards in the tire width direction from a side located at the edge of the road contact. Accordingly, in a case where a sensor detects the degree of wear of a tread section, the sensor can accurately acquire tire information.

[0013] In one embodiment of the present invention, the sensor unit is preferably directly attached to the inner surface of the tire. Accordingly, in a case where a sensor detects the degree of wear of a tread section, the sensor can accurately acquire tire information.

[0014] In a preferred embodiment of the present invention, a base is inserted between the sensor unit and the adhesive layer. Accordingly, in a case where a material that allows subsequent tire deformation is used as the base material, detachment of the sensor unit due to tire deformation can be prevented.

[0015] In one embodiment of the present invention, in a step for forming the coating layer on the bellows, a coating time t (hour) and a temperature T (°C) of the coating layer preferably satisfy the conditions t ≥ 0.0001 T2 - 0.07T + 9 and T ≤ 180 °C. Accordingly, the time required to apply the release agent in the bellows enclosing the coating layer can be reduced, and a reduction in the bellows' service life can be prevented.

[0016] In one embodiment of the present invention, ground contact edge refers to an end section in the tire axial direction of a tire mounted on a regular rim, inflated to a regular internal pressure, and arranged vertically on a flat surface with a regular load applied to the tire. A "regular rim" is a rim defined by a standard for each tire according to a system of standards that includes standards which the tires meet, and refers to a "standard rim" as defined by the Japan Automobile Tyre Manufacturers Association Inc. (JATMA), a "design rim" as defined by the Tire and Rim Association Inc. (TRA), and a "measurement rim" as defined by the European Tyre and Rim Technical Organisation (ETRTO).In the system of standards that tires meet, "regular inflation pressure" refers to an air pressure defined for each tire and is the maximum air pressure as defined by JATMA, the maximum value shown in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" as defined by TRA, and "inflation pressure" as defined by ETRTO. However, the "regular inflation pressure" is 250 kPa in the case of a tire for a passenger car.In the system of standards that tires meet, "regular load" is a load defined by each standard for each tire and is the maximum load capacity as defined by JATMA, the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" as defined by TRA, and the "LOAD CAPACITY" as defined by ETRTO. However, "regular load" is a load that is 80% of the load described above in a case where a tire is a tire for a passenger car. List of characters Fig. Figure 1 is a meridian cross-sectional view illustrating an example of a pneumatic tire according to an embodiment of the present invention. Fig. Figure 2 is an enlarged cross-sectional view of a section of the pneumatic tire made of Fig. 1. Fig. Figure 3 is a cross-sectional view of a modified example of a pneumatic tire according to an embodiment of the present invention. Fig. Figure 4 is a perspective view of another modified example of the pneumatic tire according to an embodiment of the present invention. Description of embodiments

[0017] Configurations of embodiments of the present invention are described in detail below with reference to the accompanying drawings. Fig. 1 and Fig. Figure 2 illustrates a pneumatic tire according to an embodiment of the present invention. It should be noted that in Fig. 1 CL denotes a tire center line.

[0018] As in Fig. As illustrated in Figure 1, a pneumatic tire according to an embodiment of the present invention includes a tread section extending in the circumferential direction of the tire. 1in a ring-shaped form, a pair of side wall sections 2 , 2 , which are on both sides of the tread section 1 are arranged, and a pair of bead sections 3 , 3 , which, viewed in the radial direction of the tire, are inwards from the sidewall sections 2 are arranged, one.

[0019] A carcass layer 4 is located between the pair of bead sections. 3 , 3 The carcass layer 4 encloses a plurality of reinforcing cord threads running in the tire radial direction and is folded from one tire inside to one tire outside around a bead core 5, which is located in each of the bead sections. 3a bead filler 6, which has a triangular cross-sectional shape and is made of a rubber compound, is arranged on an outer circumference of the bead core 5. Then an inner liner 9 is placed in an area between the pair of bead sections. 3 , 3 arranged on the inner surface of a tire. The inner liner 9 forms an inner surface of the tire. Ts .

[0020] On the other hand, a plurality of belt layers 7 are in an outer circumferential side of the carcass layer 4 in the tread section 1Embedded within the belt layers 7 are multiple reinforcing cord threads inclined relative to the tire's circumferential direction. The directions of the reinforcing cord threads in the different layers overlap. The angle of inclination of the reinforcing cord threads in the belt layers 7, relative to the tire's circumferential direction, is set within a range of, for example, 10° to 40°. Steel cords are preferably used as the reinforcing cords in the belt layers 7. To improve high-speed resistance, at least one belt cover layer 8, formed by arranging reinforcing cord threads at an angle of, for example, no more than 5° relative to the tire's circumferential direction, is arranged on the outer circumferential side of the belt layers 7. Organic fiber cord threads, such as nylon and aramid, are preferably used as the reinforcing cord threads in the belt cover layer 8.

[0021] It should be noted that the tire internal structure described above is a typical example for a pneumatic tire, but is not limited to that.

[0022] The pneumatic tire described above has at least one sensor unit 20 fixed in an area that corresponds to the running surface section 1 the inner surface of the tire Ts corresponds. As in Fig. As illustrated in 2, the sensor unit 20 via an adhesive layer 10 to the inner surface of the tire Ts bound.

[0023] The adhesive layer 10 It can include a liquid adhesive or double-sided adhesive tape. Examples of the adhesive include a reactive-curing adhesive, which includes an epoxy resin or a urethane resin. In particular, the adhesive layer 10preferably formed from a cyanoacrylate-based adhesive (instant adhesive) to reduce the working time required to install the sensor unit 20 on the inner surface of the tire Ts to reduce.

[0024] The sensor unit 20 The device includes a housing 21 and an electronic component 22. The housing 21 has a hollow structure and contains the electronic component 22. Depending on requirements, the electronic component 22 includes a sensor 23, which detects tire information, a transmitter, a receiver, a control circuit, a battery, and the like. Examples of tire information detected by the sensor 23 include the internal temperature and pressure of the pneumatic tire and the degree of wear of the tread section. 1One example is a temperature sensor or a pressure sensor used to measure the internal temperature or pressure. In a case where the wear level of the tread section is determined... 1 The detection can be carried out by a piezoelectric sensor that is connected to the inner surface of the tire. Ts comes into contact when sensor 23 is used, and the piezoelectric sensor detects an output voltage corresponding to a deformation of a tire during driving, and detects a degree of wear of the tread section. 1 based on the output voltage. In addition, an accelerometer or a magnetic sensor can also be used. Furthermore, the sensor unit 20 configured to transmit the tire information captured by sensor 23 out of the tire. It should be noted that the internal structure of the in Fig. 2 illustrated sensor unit 20This is one example of the sensor unit and is not limited to it.

[0025] In the pneumatic tire described above, a release agent layer 11, which includes a release agent applied in a process for manufacturing a pneumatic tire, is located between the inner surface of the tire. Ts and the adhesive layer 10 present. That is, the sensor unit. 20 , the adhesive layer 10 The release agent layer 11 is stacked on top of itself from the inner side in the tire radial direction. The thickness g of the release agent layer 11 is at least in one mounting area S for the sensor unit. 20 the inner surface of the tire Tsfrom 0.1 µm to 100 µm. The thickness g of the release agent layer 11 can be determined using an electron microscope. When measuring the thickness g of the release agent layer 11 using an electron microscope, the thickness of the release agent layer 11 is measured at a total of five locations, including the center point of the mounting area S for the sensor unit. 20 , two points on both sides in the tire circumferential direction with the center as the middle and two points on both sides in the tire width direction with the center as the middle, and the thickness at the five points are averaged to calculate the thickness g (average thickness) of the release agent layer 11.

[0026] Examples of a component that can be incorporated into the release agent layer 11 include a component containing a silicone component as an active ingredient. Examples of the silicone component include organopolysiloxanes, for example, diethylpolysiloxane, alkylphenylpolysiloxane, alkylaralkylpolysiloxane, and 3,3,3-trifluoropropylmethylpolysiloxane. Dialkylpolysiloxanes include, for example, dimethylpolysiloxane, diethylpolysiloxane, methylisopropylpolysiloxane, and methyldodecylpolysiloxane. Examples of alkylphenylpolysiloxanes include methylphenylpolysiloxane, a dimethylsiloxane-methylphenylsiloxane copolymer, and a dimethylsiloxane-diphenylsiloxane copolymer. Alkylaralkylpolysiloxanes include, for example, methyl(phenylethyl)polysiloxane and methyl(phenylpropyl)polysiloxane. One type, two, or more types of these organopolysiloxanes can be used in combination.

[0027] In the pneumatic tire described above, the thickness g of the separating agent, which is determined by an electron microscope, is at least in the mounting area S for the sensor unit. 20 set to 0.1 µm to 100 µm, and the sensor unit 20 is fixed in a state in which a trace amount of the release agent is applied to the inner surface of the tire. Ts is applied. While the release agent inhibits the penetration of air from the inner tire surface and improves the air retention properties, the adhesion between the inner tire surface and the tire can thus be improved. Ts and the sensor unit 20 Sufficiently ensured. Here, if the thickness g of the release agent in the mounting area S for the sensor unit is sufficient, 20 If the thickness is less than 0.1 µm, no improvement in air retention properties is achieved, and if the thickness g is more than 100 µm, the adhesion of the sensor unit deteriorates. 20, and sufficient consistency cannot be achieved.

[0028] In Fig. 1 and Fig. 2 is the sensor unit 20 viewed in the direction of tire width, positioned inwards from a ground contact edge. In the case where the sensor 23 detects a wear degree of the tread section 1 The sensor unit is detected 20 arranged in this way, and thus sensor 23 can accurately capture the tire information.

[0029] Furthermore, the sensor unit 20 directly with the inner surface of the tire Ts connected. In the case where sensor 23 detects a wear level of the tread section 1 The sensor unit is detected 20 in this way directly to the inner surface of the tire Ts bound, and thus sensor 23 can accurately record the tire information.

[0030] In the pneumatic tire described above, the adhesive strength of the adhesive layer is10 preferably in the range of 0.4 N / mm 2 up to 100 N / mm 2 In particular, the adhesive strength is preferably in the range of 5.0 N / mm². 2 up to 80 N / mm 2 The adhesive strength of the adhesive layer 10 This will ensure that work can be carried out to install the sensor unit. 20 easily carried out, while ensuring good adhesion of the adhesive layer 10 is maintained. If the adhesive strength of the adhesive layer is maintained here 10 less than 0.4 N / mm 2 If the amount decreases, the adhesion between the inner surface of the tire deteriorates. Ts and the sensor unit 20 , and the sensor unit 20 It detaches easily. On the other hand, if the adhesive strength of the adhesive layer... 10 more than 100 N / mm 2 This amounts to exchange work when replacing the sensor unit. 20 not easily accomplished.

[0031] Fig. Figure 3 illustrates a modified example of a pneumatic tire according to an embodiment of the present invention. As shown in Fig. As illustrated in 3, there is a connection between the sensor unit 20 and an adhesive layer 10 a base 24 was used, which includes a sensor unit 20 The base 24 acts as a damping material to prevent the sensor unit from moving. 20detaches due to tire deformation. Examples of materials for the base 24 include natural rubber (NR), chloroprene rubber (Cr), butyl rubber (IIR), ethylene propylene diene monomer (EPDM), urethane rubber, NBR, a thermoplastic elastomer, and a thermosetting elastomer. If the base 24 is made of these materials, it is less likely to be damaged by tire deformation. In particular, the base 24 can be made of rubber with an elongation at break of 80% or more. Furthermore, the base 24 is preferably in a solid state and more preferably porous. If the base 24 is porous, it has excellent damping properties and is advantageous against detachment of the sensor unit. 20due to tire deformation. Base 24 is made of the material described above, and thus base 24 can adapt its shape to tire deformation, preventing the sensor unit from detaching. 20 This can be prevented due to tire deformation. It should be noted that in the Fig. Figure 3 illustrates an example in which the base 24 is formed in a U-shape in a cross-sectional view in the tire width direction, but the shape of the base 24 is not particularly restricted. Fig. 3 corresponds to a mounting area S for the sensor unit 20 a mounting area for base 24, which holds the sensor unit 20 holds.

[0032] Fig. Figure 4 illustrates a further modified example of a pneumatic tire according to an embodiment of the present invention. As in Fig. As illustrated in section 4, the sensor unit 20 via an adhesive layer10 to the smooth surface M of a tire's inner surface Ts bound. The smooth surface M is formed during vulcanization molding using a bellows in a section central to the tire's width. The smooth surface M is an annular, flat surface extending in the tire's circumferential direction. When the sensor unit 20 on the smooth surface M of the inner tire surface Ts If arranged, the adhesion between the inner surface of the tire can be increased. Ts and the sensor unit 20 can be effectively improved. It should be noted that in Fig. 4 a mounting area S for the sensor unit 20 a mounting area for a sensor unit 20 This corresponds to a holding base of 24.

[0033] Next, a method for manufacturing a pneumatic tire according to an embodiment of the present invention is described. In the vulcanization of a tire blank, a bellows is first coated (preferably by firing) with a release agent, and a coating layer produced from the release agent is formed on an outer surface of the bellows. The step of forming the coating layer on the outer surface of the bellows is carried out while the bellows coated with the release agent is stored, for example, for 1 hour at 150 °C and 4 hours at 90 °C, or for 8 hours at room temperature. Furthermore, the step of forming the coating layer on the outside of the bellows is carried out at least once and at most three times. The tire blank is vulcanized using the bellows in which the coating layer has been formed in this way. Then, the sensor unit is attached to the vulcanized tire. 20over the adhesive layer 10 at the mounting area S for the sensor unit 20 on the inner surface of the tire Ts of the tread section 1 fixed. When vulcanization is carried out using the bellows with the coating layer produced in this way from the release agent, the release agent layer 11 is applied to the inner surface of the tire. Ts of the vulcanized pneumatic tire. In the release agent layer 11, the release agent is not completely applied to the inner surface of the tire. Ts transferred, but is applied to the inner surface of the tire. Ts scattered.

[0034] Instead of performing vulcanization using the bellows that encloses the coating layer produced from the release agent, as described above, the step of vulcanizing the tire blank can also involve applying the release agent to an inner surface of the tire blank, vulcanizing the tire blank using a regular bellows, and then blasting the inner surface of the tire. Ts enclose the vulcanized tire with a laser to enclose the area on the inner tire surface Ts to remove applied release agents.

[0035] As described above, vulcanization is carried out using the bellows, including the coating layer produced from the release agent, or vulcanization is carried out using a regular bellows and the inner tire surface TsThe vulcanized tire is irradiated with a laser to remove the release agent, thus reducing the thickness g of the release agent to at least the mounting area S for the sensor unit. 20 The thickness can be adjusted to between 0.1 µm and 100 µm. If a trace amount of the release agent is applied to the inner surface of the tire in this way... Ts is applied while the release agent prevents air from permeating out of the inner tire surface Ts inhibits and improves air retention properties, which can increase the adhesion between the inner tire surface Ts and the sensor unit 20 Sufficiently ensured.

[0036] In particular, during the step of forming the coating layer on the outer surface of the bellows, the coating time t (hours) and the temperature T (°C) of the coating layer preferably meet t ≥ 0.0001 T 2- 0.07T + 9 and T ≤ 180 °C. Furthermore, the relationship between the coating time t and the temperature T described above is preferably satisfied, and the coating time t is in the range of 1 to 8 hours. More preferably, the temperature T is 90 °C and the coating time t is 4 hours, and most preferably, the temperature T is 150 °C and the coating time t is 1 hour. Under such conditions, the time required to apply the release agent in the bellows enclosing the coating layer can be reduced, and a reduction in the bellows' service life can be prevented. Here, with increasing temperature T (°C), the coating layer can be formed in a short time, but it is more likely that the bellows will deteriorate and its service life will be reduced. Examples

[0037] Tires according to Comparative Examples 1 to 5 and Examples 1 to 7 were manufactured. The tires each have a tire size of 275 / 40R21 and include at least one sensor unit fixed to the inner tire surface by an adhesive layer and containing a sensor that acquires tire information. A method for removing a release agent, applying the release agent to the inner tire surface, using a bellows enclosing a coating layer produced from the release agent during vulcanization, and the thickness of the release agent in the inner tire surface are specified as shown in Table 1.

[0038] In comparative example 1, the release agent was applied to the inner surface of the tire, and no removal of the release agent was performed. Furthermore, in comparative examples 2 through 4, the release agent was applied to the inner surface of the tire, and its removal was performed after completion of the vulcanization step. Specifically, in comparative example 2, the release agent was removed from the inner surface of the tire by grinding; in comparative example 3, a previously bonded film was peeled off to remove the release agent from the inner surface of the tire; and in comparative example 4, the inner surface of the tire was cleaned to remove the release agent.

[0039] It should be noted that in Table 1 the thickness (µm) of the release agent on the inner surface of the tire is obtained using a scanning electron microscope (SEM-EDX) to measure the thickness of the release agent at a total of five locations, including a center point of the mounting area for the sensor unit in each test tire, obtained after the end of the manufacturing step, two locations on each side in the circumferential direction of the tire with the center point as the middle, and two locations on each side in the width direction of the tire with the center point as the middle, averaging the measured values.

[0040] The test tires were evaluated with regard to the adhesion of the sensor unit and the air retention properties using a test procedure described below. The results of the evaluation are also given in Table 1. Furthermore, the tires were evaluated with regard to bellows lifespan according to Examples 1 to 3 and 5 to 7 and Comparative Example 5, and the results of the evaluation are also given in Table 1. Adhesive strength of the sensor unit

[0041] The adhesion of the sensor unit, as used herein, indicates the assessment of detachment from an adhesive surface between the tire's inner surface and the sensor unit. Each test tire was mounted on a wheel with a rim size of 21x9.5 J, and a road test was conducted using a drum testing machine at a driving speed of 80 km / h, an air pressure of 120 kPa, a load of 8.5 kN, and a distance of 6480 km. After completion of the test, it was visually observed whether the sensor unit fell off or peeled away.If the sensor unit does not fall off or peel away, this is indicated as "excellent"; if less than 1 / 8 of the entire sensor unit is peeled off, this is indicated as "good"; if 1 / 8 or more and less than 1 / 4 of the entire sensor unit is peeled off, this is indicated as "adequate"; and if 1 / 4 or more of the entire sensor unit is peeled off, this is indicated as "poor". Air retention properties

[0042] Each test tire was mounted on a wheel with a rim size of 21 x 9.5 J and left for 24 hours at an air pressure of 270 kPa and a temperature of 21 °C. An initial air pressure of 250 kPa was then set, and the air pressure was measured for 42 days. The rate of air leakage from day 15 to day 42 was determined. The evaluation results are expressed as index values ​​using the reciprocals of the measured values, with comparison example 1 assigned as the reference numeral 100. Higher index values ​​indicate better air retention properties. Bellows lifespan

[0043] Vulcanization was carried out using a bellows, including a coating layer formed from a release agent, and the number of tire blanks that could be vulcanized in a condition where the thickness of the release agent transferred to a tire inner surface was within the range specified in one embodiment of the present invention was measured. The evaluation results are expressed as index values, with Example 1 being assigned reference numeral 100. Higher index values ​​indicate superior bellows life. [Table 1-I] Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Methods for removing release agents — Sanding Peeling off the coating cleaning Applying a release agent to the inner surface of the tire Yes Yes Yes Yes Use of a bellows including a coating layer made from release agent during vulcanization No No No No Thickness of the release agent on the inner tire surface (µm) 450 0 0 150 Coating time t (upper stage) and temperature T (lower stage) of the coating layer — — — — Adhesive strength of the sensor unit Bad Terrific Terrific Sufficient Air retention properties 100 89 96 100 Bellows lifespan — — — — [Table 1-II] Example 1 Example 2 Example 3 Example 4 Methods for removing release agents — — — laser irradiation Applying a release agent to the inner surface of the tire No No No Yes Use of a bellows including a coating layer made from release agent during vulcanization Yes Yes Yes No Thickness of the release agent on the inner tire surface (µm) 0,1 20 100 100 Coating time t (upper stage) and temperature T (lower stage) of the coating layer 2 h 23 °C 5 h 23 °C 8 h 23 °C - Adhesive strength of the sensor unit Terrific Terrific Good Good Air retention properties 98 99 100 100 Bellows lifespan 100 100 102 — [Table 1-III] Comparative example 5 Example 5 Example 6 Example 7 Methods for removing release agents — — — — Applying a release agent to the inner surface of the tire No No No No Use of a bellows including a coating layer made from release agent during vulcanization Yes Yes Yes Yes Thickness of the release agent on the inner tire surface (µm) 110 100 100 100 Coating time t (upper stage) and temperature T (lower stage) of the coating layer 9 h 23 °C 4 h 90 °C 1 h 150 °C 30 min 170 °C Adhesive strength of the sensor unit Sufficient Good Good Good Air retention properties 100 100 100 100 Bellows lifespan 101 103 105 101

[0044] As shown in Table 1, compared to Example 1, the adhesion of the sensor unit was improved in the pneumatic tires according to Examples 1 to 7, while the air retention properties were maintained. In particular, the bellows service life was improved in Examples 3 and 5 to 7.

[0045] On the other hand, in comparative example 2, because the inner tire surface was ground down, the thickness of the inner liner was reduced, thus impairing the air retention properties. In comparative example 3, because the coating was bonded to the inner tire surface and peeled off after vulcanization, the air retention properties also deteriorated. In comparative example 4, although the inner tire surface was cleaned, the release agent could not be completely removed, and a relatively large amount remained. This reduced the adhesion of the sensor unit. In comparative example 5, a large thickness of release agent was applied to the inner tire surface, and therefore, the improvement in the adhesion of the sensor unit was insufficient. Reference symbol list 1 tread section 2 Side wall section 3 bead section 10 Adhesive layer 20 sensor units Ts tire inner surface QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 6272225 B

[0004] JP 2016505438 T

[0004] JP 4410753 B

[0004] JP 2015107690 A

[0004]

Claims

[1] Pneumatic tires, including: at least one sensor unit which is attached to an inner tire surface via an adhesive layer and includes a sensor which captures tire information; wherein a thickness of the separating agent, which is determined by an electron microscope, is at least 0.1 µm to 100 µm in a mounting area for the sensor unit. [2] Pneumatic tires according to claim 1, wherein The adhesive layer has an adhesive strength in the range of 0.4 N / mm². 2 up to 100 N / mm 2 exhibits. [3] Pneumatic tires according to claim 1 or 2, wherein The adhesive layer is formed from a cyanoacrylate-based adhesive. [4] Pneumatic tires according to any one of claims 1 to 3, wherein The sensor unit is positioned inwards from a ground contact edge when viewed in the direction of tire width. [5] Pneumatic tires according to any one of claims 1 to 4, wherein the sensor unit is directly attached to the inner surface of the tire. [6] Pneumatic tires according to any one of claims 1 to 4, wherein A base is inserted between the sensor unit and the adhesive layer. [7] Method for manufacturing a pneumatic tire, comprising vulcanizing a tire blank using a bellows enclosing a coating layer made from a release agent, the method comprising: When attaching a sensor unit to an inner surface of a tread section of a vulcanized pneumatic tire, the thickness of the release agent, which is determined by an electron microscope, is set to at least 0.1 µm to 100 µm in an attachment area for the sensor unit, and the sensor unit is attached to the attachment area for the sensor unit via an adhesive layer. [8] Method for manufacturing a pneumatic tire according to claim 7, wherein in a step to form the coating layer on the bellows a coating time t (hour) and a temperature T (°C) of the coating layer t ≥ 0.0001 T 2 - 0.07T + 9 and T ≤ 180 °C must be met. [9] Method for manufacturing a pneumatic tire, wherein The method comprises: when attaching a sensor unit to an inner tire surface, irradiating the inner tire surface with a laser to remove a release agent, adjusting the thickness of the release agent, determined by an electron microscope, to at least 0.1 µm to 100 µm in an attachment area for the sensor unit, and attaching the sensor unit to the attachment area for the sensor unit via an adhesive layer.