Solid tire and method for producing the same

Abstract

A solid tire incorporating a two-dimensional code for efficient quality control and life cycle management for each product, and capable of providing sufficient protection for the two-dimensional code, and a method for producing the same are provided. A solid tire (10) has a road-contacting-side tread rubber layer (1) and a rim-side base rubber layer (2), and a two-dimensional code (11) is arranged on an outer surface (S) of the solid tire (10), excluding a base surface (B) in contact with a rim bottom. An unvulcanized tire (10X) is manufactured by winding a rubber strip (20) in multiple layers, applying a base material (13) made of a plastic film, on which the two-dimensional code (11) is printed, to the unvulcanized tire (10X), and then vulcanizing the unvulcanized tire (10X) with the two-dimensional code (11) in a mold.

Description

Technical field

[0001] The present invention relates to a solid tire represented by an air cushion tire for a commercial vehicle and a method for manufacturing the same, and in particular relates to a solid tire which has a two-dimensional code for efficient quality control and life cycle management for each product and which can provide sufficient protection for the two-dimensional code, and a method for manufacturing the same. State of the art

[0002] A pneumatic tire for a commercial vehicle is a solid tire for a forklift that has an appearance similar in shape to a pneumatic tire. This type of solid tire is used under conditions of low speed and high load, and in some cases is used under difficult conditions, such as when operating a steering wheel while the vehicle is stationary.

[0003] A solid tire generally has a tread rubber layer on the road contact surface and a base rubber layer on the rim side. The base rubber layer is made of a hard rubber or rubber compound, and the tread rubber layer is made of a rubber or rubber compound in which grip properties, wear resistance, chipping properties, heat build-up, and rolling resistance play a particularly important role (see, for example, patent specifications 1 to 3).

[0004] There is a need for quality control and lifecycle management for each of the aforementioned solid tires. Unfortunately, no specific means for efficiently implementing quality control and lifecycle management for each product within a solid tire range have yet been proposed. List of literature on patent literature Patent Document 1: JP H10-147107 A Patent Document 2: JP 2010-163123 A Patent Document 3: JP 2016-117296 A Brief description of the invention: Technical problem

[0005] One object of the present invention is to provide a solid tire which contains a two-dimensional code for efficient quality control and life cycle management for each product and offers sufficient protection for the two-dimensional code, as well as a method for producing the same. Solution to the problem

[0006] A solid tire of an embodiment of the present invention for achieving the aforementioned objective is a solid tire comprising a tread rubber layer on a road contact surface and a base rubber layer on a rim surface. A two-dimensional code is arranged on an outer surface of the solid tire, excluding a base surface therein that is in contact with the underside of the rim.

[0007] A method for manufacturing a solid tire of an embodiment of the present invention is a method for manufacturing the solid tire described above and includes forming an unvulcanized tire by winding a rubber strip in several layers; applying a base material of a plastic film, on which the two-dimensional code is printed, to the unvulcanized tire; and then vulcanizing the unvulcanized tire with the two-dimensional code in a mold.

[0008] Another method for producing a solid tire of an embodiment of the present invention is a method for producing the solid tire described above and includes forming an unvulcanized tire by winding a rubber strip in several layers; arranging a base material of a plastic film, on which the two-dimensional code is printed, on an inner surface of a mold; and vulcanizing the unvulcanized tire together with the two-dimensional code in the mold. Advantageous effects of the invention

[0009] One embodiment of the present invention is a solid tire that includes the tread rubber layer on the road contact patch side and the base rubber layer on the rim side, wherein the two-dimensional code is arranged on the outer surface of the solid tire, excluding the base surface, thus enabling quality control and lifecycle management for each product. Since the base surface of the solid tire is subjected to considerable stress both during rim mounting and while driving, the two-dimensional code becomes damaged and difficult to read if it is located on the base surface. However, since the two-dimensional code is arranged on the outer surface of the solid tire, excluding the base surface, sufficient protection for the two-dimensional code can be ensured, and quality control and lifecycle management for each product can be carried out over a long period.

[0010] In the present invention, the two-dimensional code is preferably arranged in a position outside a rim friction zone, which is defined as within a range of -15% to +15% of the rim flange height, with the apex of the rim flange as its center. During driving, the solid tire flexes in the radial, lateral, and circumferential directions and rubs against the rim flange near its apex. Therefore, if the two-dimensional code is located within the rim friction zone as defined above, there is a risk of damage to the two-dimensional code. Conversely, sufficient protection for the two-dimensional code can be achieved if it is arranged in a position outside the rim friction zone.The rim flange height is the radial height of a rim from a rim diameter position on a specified rim to a rim flange apex. "Specified rim" refers to a rim defined within a standards system that includes standards upon which tires are based, according to the standards for each tire. For example, it refers to a rim that complies with JATMA (Japan Automobile Tyre Manufacturers Association, Inc.). The dimensions of the rim that comply with JATMA are defined by JIS-D6402 "Wheels for industrial vehicles and off-the-road service—contours of rims."

[0011] The two-dimensional code is preferably located on the inside of the tire, radially from the apex of the rim flange, at a position outside the rim friction zone. If the two-dimensional code is located on the outside of the tire, radially from the apex of the rim flange, there is a risk of scratches or dirt getting onto it while driving. In contrast, if the two-dimensional code is located on the inside of the tire, radially from the apex of the rim flange, the risk of scratches or dirt getting onto it is reduced.

[0012] The two-dimensional code is preferably positioned in a range of 0% to 45% of the rim flange height. Within this range, the movement of the base rubber layer is reduced, thereby minimizing friction against the rim flange and effectively preventing wear of the two-dimensional code.

[0013] Preferably, the two-dimensional code is arranged on the base rubber layer, and the base rubber layer has a JIS-A hardness of 80 or more. By arranging the two-dimensional code on the hard base rubber layer, movements of the base rubber layer in the tire radial, lateral, and circumferential directions are reduced during driving, thereby reducing friction against the rim flange and effectively preventing wear of the two-dimensional code. The JIS-A hardness in the present invention is the durometer hardness measured according to JIS-K6253 using a type A durometer at a temperature of 23 °C ± 2 °C.

[0014] Short fibers are preferably mixed into a rubber compound forming the base rubber layer. This increases the modulus in an area of ​​low elongation of the base rubber layer and reduces the movement of the base rubber layer in the tire radial, lateral, and circumferential directions during driving, thereby reducing friction on the rim flange and effectively preventing wear of the two-dimensional code.

[0015] In the present invention, the base material, a plastic film onto which the two-dimensional code is printed, is preferably bonded to the outer surface via an adhesive layer. This allows the two-dimensional code to be added to the outer surface of the solid tire easily and securely.

[0016] Preferably, the rubber layer in the section where the base material is bonded contains at least 30 phr of natural rubber and sulfur as a vulcanizing agent, and the adhesive layer consists of a natural rubber-based pressure-sensitive adhesive containing only a vulcanization accelerator without a vulcanizing agent. If the natural rubber-based pressure-sensitive adhesive contains a vulcanizing agent, vulcanization occurs during storage prior to tire molding, and the adhesive strength tends to decrease during use. Therefore, the adhesive strength of the adhesive layer can be maximized and the two-dimensional bond maintained over a long period by including sulfur as a vulcanizing agent in the rubber layer in the area where the base material is bonded, while the adhesive layer consists of a natural rubber-based pressure-sensitive adhesive containing only a vulcanization accelerator without a vulcanizing agent.

[0017] The bond strength between the outer surface and the base material is preferably 60 N / 10 mm or more. Such a bond strength prevents the base material from detaching and ensures that the two-dimensional code remains intact over a long period.

[0018] A primer layer of resorcinol-formaldehyde latex is preferably arranged between the adhesive layer and the base material. The inclusion of such a primer layer increases the bond strength between the adhesive layer and the base material.

[0019] The method for producing a solid tire of an embodiment of the present invention makes it easy to produce the solid tire described above by forming an unvulcanized tire by winding a rubber strip in several layers, applying a base material made of a plastic film on which a two-dimensional code is printed, and then vulcanizing the unvulcanized tire with the two-dimensional code in a mold.

[0020] In the method for manufacturing a solid tire according to one embodiment of the present invention, a base layer of unvulcanized rubber with a thickness of 0.5 mm to 10 mm is preferably applied to a surface of the unvulcanized tire, and a base material made of a plastic film, on which the two-dimensional code is printed, is laid overlapping onto the base layer and applied thereon. When an unvulcanized tire is manufactured by winding a rubber strip in several layers, a height difference arises at a boundary between the layers of rubber strips, and during vulcanization, this height difference causes rubber flow. Such rubber flow leads to a misalignment of the two-dimensional code and also causes the two-dimensional code to be hidden in the rubber.By overlapping and applying the base material, a plastic film onto which the two-dimensional code is printed, to the base layer, misalignment and obscuration of the two-dimensional code can be prevented.

[0021] In the method for manufacturing a solid tire according to one embodiment of the present invention, the base material, consisting of a plastic film on which the two-dimensional code is printed, is preferably arranged on a section of the unvulcanized tire that corresponds to a flat section of a mold. The surface of a mold has a complex shape. Therefore, if a part of the mold with which the two-dimensional code comes into contact during vulcanization is inclined or curved, there is a risk of misalignment or deformation of the two-dimensional code, rendering it unreadable. Therefore, by arranging the base material, consisting of the plastic film on which the two-dimensional code is printed, on the section of the unvulcanized tire that corresponds to the flat section of the mold, misalignment or deformation of the two-dimensional code can be prevented.

[0022] In the method for manufacturing a solid tire according to one embodiment of the present invention, the base material, a plastic film on which the two-dimensional barcode is printed, is preferably arranged on a section of the unvulcanized tire, excluding the beginning and end of the rubber strip winding. When an unvulcanized tire is manufactured by winding a rubber strip in multiple layers, gaps and irregularities form at the beginning and end of the rubber strip windings on the tire's sidewall and tread surface. During vulcanization, these gaps and irregularities cause rubber to flow. Such rubber flow leads to misalignment of the two-dimensional code and also causes the two-dimensional code to become embedded in the rubber.Therefore, by arranging the base material made of plastic film, on which the two-dimensional barcode is printed, on a section of the unvulcanized tire excluding the beginning and end ends of the winding of the rubber strip, misalignment and obscuration of the two-dimensional code can be prevented.

[0023] In another method for producing a solid tire of an embodiment of the present invention, the solid tire described above can be easily produced by forming an unvulcanized tire by winding a rubber strip in several layers, arranging a base material made of a plastic film, on which a two-dimensional code is printed, on an inner surface of a mold, and vulcanizing the unvulcanized tire together with the two-dimensional code in the mold. Brief description of the drawings Fig.Figure 1 is a meridian cross-sectional view illustrating a solid tire according to an embodiment of the present invention. Fig. Figure 2 is a meridian cross-sectional view illustrating a rim friction area in a solid tire. Fig. Figure 3 is a meridian cross-sectional view illustrating a solid tire according to another embodiment of the present invention. Fig. Figure 4 is an enlarged cross-sectional view illustrating part of a base rubber layer into which short fibers are mixed. Fig. Figure 5 is a cross-sectional view illustrating a state in which a base material, onto which a two-dimensional code is printed, is bonded to an outer surface. Fig.Figure 6 is a meridian cross-sectional view illustrating an unvulcanized tire in a method for manufacturing a solid tire according to an embodiment of the present invention. Fig. Figure 7 is a meridian cross-sectional view illustrating an unvulcanized tire in a method for manufacturing a solid tire according to a further embodiment of the present invention. Fig. Figure 8 is a meridian cross-sectional view illustrating an unvulcanized tire and a mold in a method for manufacturing a solid tire according to yet another embodiment of the present invention. Fig. Figure 9 is a meridian cross-sectional view illustrating an unvulcanized tire in a method for manufacturing a solid tire according to yet another embodiment of the present invention. Fig.Figure 10 is a meridian cross-sectional view illustrating an unvulcanized tire and a mold for producing a solid tire according to yet another embodiment of the present invention. Fig. Figure 11 is a meridian cross-sectional view illustrating a solid tire according to yet another embodiment of the present invention. Fig. Figure 12 is a meridian cross-sectional view showing an unvulcanized tire during a process for manufacturing the in Fig. 11 illustrated full tires illustrated. Fig. Figure 13 is a top view that schematically illustrates a test track. Description of embodiments

[0024] Configurations of embodiments of the present invention are described in detail below with reference to the accompanying drawings. Fig.Figure 1 illustrates a solid tire (air cushion tire for a commercial vehicle) according to an embodiment of the present invention.

[0025] As in Fig. As illustrated in Figure 1, a solid tire 10 of the present embodiment has a toroidal shape and has a tread rubber layer 1 positioned on the road contact surface side (outside in tire radial direction) and a base rubber layer 2 positioned on the rim side (inside in tire radial direction).

[0026] The tread rubber layer 1 is formed from a rubber compound consisting mainly of a diene-based rubber, such as natural rubber, styrene-butadiene rubber, or butadiene rubber. Carbon black or silica may be added to the rubber compound forming the tread rubber layer 1 as a reinforcing agent, and in the case of silica, an organic silane adhesion promoter or the like may also be added. An example of the organic silane adhesion promoter may include bis(triethoxysilylpropyl)tetrasulfide (TESPT). The rubber compound forming the tread rubber layer 1 may contain other commonly used compounding agents, resins, oils, plasticizers, and the like.

[0027] The JIS-A hardness of the tread rubber layer 1 is not particularly limited, but preferably lies, for example, in the range of 50 to 75. If the JIS-A hardness of the tread rubber layer 1 is below 50, the amount of distortion in the tire radial direction becomes too large and the horizontal stiffness too low due to a reduction in stiffness. Conversely, if the JIS-A hardness of the tread rubber layer 1 is above 75, the amount of distortion in the tire radial direction is reduced due to an increase in stiffness, and the vibration absorption effect is reduced, thereby impairing ride comfort.

[0028] The base rubber layer 2 is formed from a rubber compound consisting primarily of a dien-based rubber, such as natural rubber, styrene-butadiene rubber (SBR), or butadiene rubber. SBR with a high styrene content may be used to increase hardness. Carbon black and, furthermore, a phenolic resin, an oil-modified phenolic resin, or the like may be added to the rubber compound forming the base rubber layer 2 as reinforcing agents. Hexamethylenetetramine or the like may be added as a hardening agent for the phenolic resin. The rubber compound of which the base rubber layer 2 is composed may contain other commonly used compounding agents, resins, oils, plasticizers, and the like.

[0029] The base rubber layer 2 preferably has a JIS-A hardness of 80 or higher. If the JIS-A hardness of the base rubber layer 2 is below 80, the amount of distortion in the tire's radial direction becomes too great, and the horizontal stiffness becomes too low due to a reduction in stiffness. Insufficient stiffness of the base rubber layer 2 causes rim friction during driving due to contact between the base rubber layer 2 and the rim flange.

[0030] In the base rubber layer 2, two or more bead cores 3 are arranged in a ring-like fashion along a circumferential direction of the tire. The bead cores 3 are arranged symmetrically with respect to an equatorial plane of the tire. The bead core 3 can be a bead core formed by repeatedly winding a multitude of bead wires (so-called stranded bead wire), a bead core formed by repeatedly winding a single bead wire, a bead core formed from a single steel ring, or the like. To ensure adhesion to the base rubber layer 2, its surface is generally zinc-plated or brass-plated with tin and copper, and, if a steel ring is used, its surface is generally coated with various vulcanizing adhesives. Instead of providing the bead core 3, short fibers can be embedded in the rubber or steel forming the base rubber layer 2.The rubber composition can be mixed. If necessary, short fibers can be mixed into the rubber composition forming the base rubber layer 2 while simultaneously providing the bead cores 3. These short fibers can be made from organic fibers such as nylon, polyester, rayon, aramid, and Vinalon.

[0031] In the solid tire 10 described above, a two-dimensional code 11 is arranged on an outer surface S, excluding a base surface B that is in contact with the underside of a rim. The base surface B is an inner circumferential surface formed on an inner side in the tire width direction by a curved heel section that is in contact with a rim flange of the solid tire 10. Fig.1. The two-dimensional codes 11 are arranged at several locations on the outer surface S, excluding the base surface B; however, the two-dimensional code 11 may be arranged at at least one location on the outer surface S, excluding the base surface B. The two-dimensional code 11 may be arranged on the tread (including the inside of a groove) or the sidewall of the solid tire 10, provided that it is the outer surface S, excluding the base surface B.

[0032] The two-dimensional Code 11 is a matrix-type code that contains information in two mutually orthogonal directions. Examples of the two-dimensional Code 11 include QR code (registered trademark), DataMatrix (registered trademark), MaxiCode, PDF-417 (registered trademark), 16K code (registered trademark), 49 code (registered trademark), Aztec code (registered trademark), SP code (registered trademark), VeriCode (registered trademark), and CP code (registered trademark).

[0033] In the case of the solid tire 10, which has the tread rubber layer 1 on the road contact surface and the base rubber layer 2 on the rim side, the two-dimensional code 11 is arranged on the outer surface S, excluding the base surface B. This allows for quality control and traceability management for each product using the two-dimensional code 11. In other words, it is possible to perform quality control by linking an identification number stored in the two-dimensional code 11 to a manufacturing condition, and to ensure traceability after shipment by using the identification number stored in the two-dimensional code 11. The base surface B of the solid tire 10 is subjected to strong compression both during rim mounting and while driving.Therefore, if the two-dimensional code 11 is arranged on the base surface B, the two-dimensional code becomes damaged and difficult to read. In contrast, since in one embodiment of the present invention the two-dimensional code 11 is arranged on the outer surface B of the solid tire 10, excluding the base surface B, sufficient protection can be provided for the two-dimensional code 11, and quality control and lifecycle management can be carried out for each product over a long period of time.

[0034] The two-dimensional code 11 is preferably located in a region of 75% or less of the tire's cross-sectional height. This is because the solid tire 10 wears down during driving. To ensure the effectiveness of the two-dimensional code 11 over a long period, it is therefore preferably positioned outside a tread-side region of 25% of the tire's cross-sectional height. The solid tire 10 typically has a wear indicator marking at a tread-side position of 25% of the tire's cross-sectional height.The wear threshold marking is an indicator to prevent a deterioration of driving comfort, a reduction in braking performance, a reduction in rolling resistance, an increase in heat generation due to heat build-up, a reduction in speed, a reduction in starting power and the like when the tire wears beyond this marking.

[0035] Fig. Figure 2 illustrates a rim friction area for a solid tire. The two-dimensional code 11 is preferably arranged at a position that lies outside a rim friction area X. That is, the solid tire 10 is, as shown in Fig.Figure 2 illustrates that, when mounted on a rim R at the time of use, but under demanding operating conditions such as sudden acceleration, sudden braking, and sharp turns, wear or damage due to rim friction is likely to occur near the apex of a rim flange F. Therefore, by arranging the two-dimensional code 11 at a position outside the rim friction zone X, which is defined as within a range of -15% to 15% of a rim flange height H with the apex of the rim flange F as its center, the protective effect for the two-dimensional code 11 can be sufficiently ensured, even if rim friction occurs in the solid tire 10.

[0036] The two-dimensional code 11 is preferably located on the inside of the tire at a point outside the rim friction zone X, extending radially from the apex of the rim flange F. If the two-dimensional code 11 is located on the outside of the tire at the apex of the rim flange F, there is a risk of scratches or dirt accumulating on it while driving. For example, if the two-dimensional code 11 rubs against or is struck by a foreign object such as the side of a pallet, a step, or a stone while driving, it will be scratched. Dust, dirt, oil, or similar substances can make the two-dimensional code 11 difficult to read. In contrast, if the two-dimensional code 11 is located on the inside of the tire at the apex of the rim flange F, extending radially from the tire, the likelihood of scratches or dirt accumulating on it is reduced.In this case, the two-dimensional code 11 is checked after removing the rim R.

[0037] The two-dimensional code 11 is preferably arranged in a range of 0% to 45% of the height H of the rim flange F. In such a range, the movement of the base rubber layer 2 is reduced, thereby decreasing friction on the rim flange F and effectively preventing wear of the two-dimensional code 11.

[0038] Preferably, the two-dimensional code 11 is arranged on the base rubber layer 2, and the JIS-A hardness of the base rubber layer 2 is 80 or higher. By arranging the two-dimensional code 11 on the hard base rubber layer 2, the movement of the base rubber layer 2 in the tire radial, tire width, and tire circumferential directions during driving is reduced, thereby reducing friction on the rim flange F and effectively preventing wear of the two-dimensional code 11.

[0039] Fig.Figure 3 shows a solid tire according to a further embodiment of the present invention. Fig.3. An intermediate rubber layer 4 with a high cushioning effect is inserted between the tread rubber layer 1 and the base rubber layer 2. Inserting such an intermediate rubber layer 4 suppresses heat build-up in the tread rubber layer 1 and improves its wear resistance. The rubber or compound used for the intermediate rubber layer 4 is preferably one that is softer than both the tread rubber layer 1 and the base rubber layer 2 and has a low loss factor tan δ. The intermediate rubber layer 4 can consist of not only one layer, but also two or more layers. Alternatively, the intermediate rubber layer 4 can have a rubber hardness between that of the tread rubber layer 1 and the base rubber layer 2. This ensures adequate vertical and horizontal stiffness, etc.In the case of the solid tire 10, which has the tread rubber layer 1 on the road contact surface side, the base rubber layer 2 and the intermediate rubber layer 4 arranged in between, the two-dimensional code 11 is arranged on the outer surface S excluding the base surface B.

[0040] In the solid tire 10 described above, as in Fig.Figure 4 illustrates that short fibers 5 are preferably mixed into the rubber or rubber composition forming the base rubber layer 2. This increases the modulus of the base rubber layer 2 in a low-elongation region and reduces the movement of the base rubber layer 2 in the tire radial, tire width, and tire circumferential directions during driving, thereby reducing friction on the rim flange F and effectively preventing wear of the two-dimensional code 11. This enhances the protective effect of the two-dimensional code 11. When the rubber containing the mixed short fibers 5 is rolled out into a strip, the short fibers 5 often align in a strip-rolling direction. For this reason, the short fibers 5 in the base rubber layer 2 are preferably oriented in the tire circumferential direction.By aligning the short fibers 5 of the base rubber layer 2 in the circumferential direction of the tire in this way, the protective effect for the two-dimensional code 11 and a barrel tire effect on the rim is effectively created, and the effect of increasing the vertical stiffness and the horizontal stiffness of the tire can be improved in addition to the effect of preventing rim slippage.

[0041] The short fibers 5, which are not limited to a specific fiber type, can, for example, contain Vinalon fibers from 0.5 phr to 10 phr with a fiber length of 2 mm to 10 mm and a fiber diameter of 5 µm to 50 µm. Such a Vinalon fiber is suitable as a reinforcing material for the base rubber layer 2. Here, the amount of Vinalon fibers mixed in, less than 0.5 phr, reduces the modulus in the low-elongation region, and the base rubber layer 2 exhibits reduced stiffness and bends easily, thus reducing the protective effect for the two-dimensional Code 11. On the other hand, if the amount of Vinalon fibers mixed in exceeds 10 phr, the modulus in the low-elongation region becomes too high, and the tire's mountability on rims deteriorates. Due to the fiber length of less than 2 mm, the modulus decreases in the low strain area, thus reducing the protective effect for the two-dimensional Code 11.On the other hand, a fiber length greater than 10 mm leads to an excessively high modulus in the low-stretch region, which impairs mountability on rims. Furthermore, if the fiber diameter is less than 5 µm, the dispersibility of the short fibers during rubber kneading is reduced, while if the fiber diameter exceeds 50 µm, the modulus in the low-stretch region is reduced due to a decrease in the specific surface area of ​​the Vinalon fiber, thus reducing the protective effect for the two-dimensional Code 11. Additionally, if the fiber diameter is too large, it becomes a foreign substance, which is undesirable.

[0042] Fig. Figure 5 illustrates a state in which the base material 13, onto which the two-dimensional code 11 is printed, is bonded to the outer surface S. More precisely, in Fig.5 The base material 13, consisting of a plastic film with a printed layer 12 containing the two-dimensional code 11, is bonded to the outer surface S via an adhesive layer 14. The base material 13, made of plastic film and bearing the printed two-dimensional code 11, is bonded to the outer surface S via the adhesive layer 14, allowing the two-dimensional code 11 to be easily and securely applied to the outer surface S of the solid tire 10.

[0043] The printing ink used for printing layer 12 is preferably a resin-based ink. If a surface of the resin-based ink is additionally coated with a transparent resin, the mold will not be contaminated with ink components during the rubber vulcanization process. Examples of resins used in the ink include polyester-based, polyamide-based, acrylic-based, polycarbonate-based, and phenol-based resins. Of these, polyester-based resins are preferable. The resins contained in the ink can be used alone or in a combination of two or more resins.

[0044] Examples of coating materials used in coating treatment include resins such as polyester-based resins (e.g., polyester, polyester polyether, polyester polyurethane, and polyester vinyl); acrylic-based resins; acrylic-urethane resins; acrylic-silicone resins; urethane-based resins; vinyl chloride resins; vinyl chloride-vinyl acetate resins; phenol-based resins; epoxy-based resins; or combinations thereof. Examples of ester-based resins used as coating agents include saturated ester-based resins such as the "Vylon" series (available from Toyobo Co., Ltd.) (e.g., Vylon 29SS), the "Polyester" series (available from Nippon Synthetic Chemical Industry Co., Ltd.) (e.g., Polyester LP050), the "Espel" series (available from Hitachi Chemical Co., Ltd.) (e.g., Espel 9940A), "Rigolac" (available from Showa Denko KK), and the "Arakyd" series (available from Arakawa Chemical Industries, Ltd.) (e.g.,7063) as well as unsaturated ester-based resins such as “Sundhoma” and “Exdhoma” (available from DIC Corporation).

[0045] There are no particular restrictions on the coating treatment, and it can be carried out on the plastic film using a method appropriate to the material, for example, a coating process using a rod coater, an engraving roller, or the like, or a hot melt coating process. The thickness of the layer formed by the coating treatment, consisting of the coating material, is not subject to any particular restrictions, but is preferably, for example, 0.1 µm to 30 µm, and more preferably 0.1 µm to 20 µm.

[0046] The plastic film of the base material 13 preferably consists of a synthetic resin with a melting point of 200°C or higher. This means that, since the vulcanization temperature of a tire is at most about 160°C, the plastic film with the aforementioned melting point does not melt during vulcanization.

[0047] The plastic film can consist of at least one resin selected from the group comprising polyester-based resin, polyimide-based resin, polyamide-based resin, polycarbonate-based resin, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyvinylidene chloride, nylon 6, nylon 66, polyphenylene sulfide, polyetherimide, polysulfone, polyamide-imide, acetylcellulose, cellulose propionate, ethylcellulose, polyethylene naphthalate, modified polyphenylene ether, polyarylate, and polymethylpentene. These resins can be used alone or as a mixture of two or more resins, and the plastic film can have a single-layer or multi-layer structure. Of these, a plastic film made from a polyester-based resin is preferred, and for reasons of cost and handling, a polyethylene terephthalate resin is more preferred.

[0048] Polyethylene terephthalate resin has a melting point of 260°C and a cold resistance down to -60°C. Therefore, it does not melt during tire vulcanization and does not crack when used in low-temperature environments. Polyethylene terephthalate resin is superior to polyethylene and polypropylene resins in terms of adhesive properties. These resins adhere poorly to the rubber layer. Polyethylene terephthalate resin possesses excellent mechanical properties and is used for photographic films, industrial adhesive tapes, packaging materials, and similar applications. It is also highly recyclable and does not release toxic gases, even when burned. To make the printed design stand out, a white filler is preferably included in the plastic film.

[0049] The thickness of the base material 13 is preferably 50 µm to 1000 µm. Base material 13 with a thickness of less than 50 µm becomes too thin and can wrinkle or tear easily due to rubber flow during vulcanization, which is not preferred. Base material 13 with a thickness of more than 1000 µm becomes too hard and can partially detach due to rubber bending or the like during use as a tire, and, if detached, cracks or the like may occur in the detached sections, which is not preferred. The thickness of the base material 13 is preferably 50 µm to 500 µm and more preferably 100 µm to 300 µm.

[0050] Preferably, the rubber layer (for example, the base rubber layer 2) in a section where the base material 13 is bonded contains at least 30 phr of natural rubber and sulfur as a vulcanizing agent, and the adhesive layer 14 consists of a natural rubber-based pressure-sensitive adhesive containing only a vulcanization accelerator and no vulcanizing agent. If the natural rubber-based pressure-sensitive adhesive contains a vulcanizing agent, vulcanization occurs during storage prior to tire molding, and the adhesive strength tends to decrease during use. The adhesive layer 14 consists of a natural rubber-based pressure-sensitive adhesive containing only a vulcanization accelerator and no vulcanizing agent, thus enabling the adhesive layer 14 to be stored for extended periods.On the other hand, the vulcanizing agent required for the vulcanization of the adhesive layer 14 is provided by being transferred from the rubber layer side to the area where the base material 13 is bonded during vulcanization. This allows the adhesive strength of the adhesive layer 14 to be maximized and the two-dimensional code 11 to be maintained over a long period of time.

[0051] The natural rubber-based pressure-sensitive adhesive of which the adhesive layer 14 consists is produced by using either natural rubber or isoprene rubber alone, or a rubber-based polymer consisting mainly of natural rubber or isoprene rubber and containing an additional component of butadiene rubber, styrene-butadiene rubber, nitrile rubber, butyl rubber or the like in a total amount of 100 phr, and appropriately blending 5 to 50 phr of a tackifier, 1 to 10 phr of a vulcanization accelerator and other additives such as amine- or phenol-based anti-aging agents, oil and plasticizers. Examples of the pressure-sensitive adhesive include an acrylic-based pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, and a natural rubber-based pressure-sensitive adhesive, and in the present invention, a sulfur-crosslinked natural rubber-based pressure-sensitive adhesive is best suited.

[0052] For example, one or more of the following can be used as tackifiers to regulate adhesion strength and the like: terpene-based resins, rosin-based resins, hydrogenated rosin-based resins, phenol-based resins, oil-modified phenol resins, alkylphenol-based resins and their glycerol esters, coumaron-indene-based resins, terpenephenol-based resins, aliphatic or aromatic petroleum-based resins, and the like.

[0053] One or more vulcanization accelerators from the group of thiuram-based vulcanization accelerators such as TMTD, TETD, TBTD, TBZTD, TMTM, TRA and TOT-N and dithiocarbamate-based vulcanization accelerators such as ZDMC, ZDEC, ZDBC, ZEPC, ZPMC and ZDBZC can be used.

[0054] The thickness of the adhesive layer 14 is preferably 10 µm to 50 µm and more preferably 15 µm to 40 µm. A thickness of less than 10 µm for the adhesive layer 14 reduces the adhesive strength and can lead to insufficient adhesion to the unvulcanized tire, which is not preferred. On the other hand, a thickness greater than 50 µm can cause the adhesive to protrude excessively during processing, resulting in minimal improvement in adhesion and an excessively high quality, which is not preferred.

[0055] A primer layer 15 is preferably arranged between the adhesive layer 14 and the base material 13. The adhesion strength between the adhesive layer 14 and the base material 13 can be increased by interposing such a primer layer 15. A mixture of resorcinol and formaldehyde or the like is preferred as the primer forming the primer layer 15. Of these, a chlorophenol-based RFL primer (resorcinol, formaldehyde, latex) is preferred. In this case, the amount of RFL used is appropriately determined depending on the desired adhesion strength, but is generally preferably 100 parts by weight or less, more preferably 5 to 80 parts by weight, even more preferably 10 to 67 parts by weight, and particularly preferably 10 to 50 parts by weight per 100 parts by weight of chlorophenol. The composition of RFL is typically in the weight ratio R: F: L = 1.0:0.5 to 2.0:2.0 to 10.0.

[0056] The viscosity of the primer is not subject to any particular restrictions, but is preferably between 2 mPa·s and 10 Pa·s, and more preferably between 10 mPa·s and 7 Pa·s, as this allows the primer to be applied evenly and also ensures excellent adhesion between the primer layer and the plastic film. The viscosity of the primer is measured using a type B viscometer.

[0057] The thickness of the primer layer 15 is preferably 2 µm to 50 µm, more preferably 5 µm to 30 µm, and even more preferably 10 µm to 20 µm. A primer layer thickness of less than 2 µm reduces the adhesion strength and can easily lead to partially thin sections, resulting in unstable adhesion. On the other hand, a thickness greater than 50 µm does not significantly improve the adhesion strength and results in an excessively high-quality finish, which is not preferred.

[0058] Based on the adhesive structure described above, the adhesive strength between the outer surface S of the solid tire 10 and the base material 13 is preferably 60 N / 10 mm or more. By ensuring such an adhesive strength, it is possible to prevent detachment of the base material 13 and to maintain the two-dimensional code 11 over a long period of time.

[0059] Fig. Figure 6 illustrates an unvulcanized tire in a method for manufacturing a solid tire according to an embodiment of the present invention. Fig. 6 denotes D a cylindrical mounting drum that can be extended and retracted. In the manufacture of the solid tire 10 described above, as in Fig.Figure 6 shows an unvulcanized tire 10X formed by wrapping a rubber strip 20 in several layers around the forming drum D. The base material 13, consisting of a plastic film on which the two-dimensional code 11 is printed, is then applied to the unvulcanized tire 10X. The unvulcanized tire 10X with the two-dimensional code 11 is then vulcanized in a mold with a cavity corresponding to the shape of the solid tire 10. This allows the solid tire 10 described above to be easily manufactured.

[0060] Fig.Figure 7 illustrates an unvulcanized tire in a method for manufacturing a solid tire according to another embodiment of the present invention. In the above-described method for manufacturing the solid tire 10, a base layer 21 of unvulcanized rubber with a thickness of 0.5 mm to 10 mm can be applied to the unvulcanized tire 10X, and the base material 13, consisting of a plastic film on which the two-dimensional code 11 is printed, can be laid overlapping onto and applied to the base layer 21. When an unvulcanized tire 10X is formed by winding the rubber strip 20 in several layers, a height difference arises at a boundary between the layers of the rubber strip 20, and during vulcanization, rubber flow occurs due to this height difference.Such rubber flow causes a positional misalignment of the two-dimensional code 11 and also leads to the two-dimensional code 11 being hidden within the rubber. Overlapping and applying the base material 13, made of plastic film and bearing the printed two-dimensional code 11, to the base layer 21 prevents positional misalignment and the concealment of the two-dimensional code 11. If the thickness of the base layer 21 is less than 0.5 mm, it becomes too thin, and there is a risk of positional misalignment or concealment due to rubber flow during vulcanization. If the thickness exceeds 10 mm, it becomes too thick, and there is also a risk of positional misalignment or concealment.When the thick base layer 21 is applied to the unvulcanized tire 10X and is thus located near a boundary between the tread rubber layer 1 and the base rubber layer 2, the interface between the two layers can be disrupted. The thickness of the base layer 21 is preferably 2 mm to 6 mm. The tread surface is among the objects to which the base layer 21 is attached.

[0061] In the above-described method for manufacturing the solid tire 10, the base material 13, on which the two-dimensional code 11 is printed, can be attached to the unvulcanized tire 10X during its formation by winding the rubber strip 20 in multiple layers. In this case, preferably, when winding the rubber strip 20 in multiple layers, an outer diameter position of the build-up drum D is used as a reference. A winding position of the rubber strip 20 in the radial direction of the unvulcanized tire 10X is calculated according to a winding length and thickness of the rubber strip 20, and the base material 13, on which the two-dimensional code 11 is printed, can be attached according to the winding position. In this way, the base material 13, on which the two-dimensional code 11 is printed, can be attached during or after the multi-layer winding process.

[0062] For example, if the two-dimensional code 11 is applied during multi-layer winding, the winding of the rubber strip 20 can be temporarily stopped at a predetermined position, the base material 13, on which the two-dimensional code 11 is printed, can be applied, and then the winding can continue. This process can be repeated multiple times if a large number of two-dimensional codes 11 are applied. For example, in a tire with a two-layer construction and a size of 5.00-8, the base rubber strip has a width of 120 mm and a thickness of 8 mm, and the winding is stopped once when the base rubber strip has been wound in four layers. The base material 13, on which the two-dimensional code 11 is printed, is applied, and the base rubber strip is then wound further in two layers.The tread rubber strip is then wound, and the unvulcanized 10X tire with a total height of 110 mm is complete. When this is vulcanized in a predetermined shape to create a finished product, the two-dimensional code 11 is positioned at approximately 200% of the rim flange height H. This allows for highly accurate placement of the two-dimensional code 11. The application process can also be automated if the winding position of the rubber strip in the radial direction of the unvulcanized 10X tire is calculated according to the winding length and thickness of the rubber strip, and the base material 13, onto which the two-dimensional code 11 is printed, is applied according to the winding position.

[0063] As another method, when winding the rubber strips 20 in several layers in the manufacturing process for the solid tire 10, the outer diameter position of the forming drum D is used as a reference. A position of the unvulcanized tire 10X in the radial direction, for example in three-dimensional spatial coordinates (X, Y, Z), is detected. The position and shape of the object are measured using a three-dimensional measuring device, an image recognition sensor, or the like, and the two-dimensional code 11 is applied accordingly. The two-dimensional code 11 can be applied during or after the multi-layer winding.In particular, for example, if the two-dimensional code 11 is applied during multi-layer winding, the winding of the rubber strips 20 can be temporarily stopped at a stage where a predetermined position is reached, the two-dimensional code 11 can be applied, and then the winding can be continued. This process can be repeated multiple times when applying a large number of two-dimensional codes 11 at different positions. Using this method, the running surface and the position corresponding to the groove can also be measured, and the two-dimensional code 11 applied based on the measurement result. The process of applying the two-dimensional code 11 can also be automated.

[0064] Fig.Figure 8 illustrates an unvulcanized tire and a mold in a method for manufacturing a solid tire according to yet another embodiment of the present invention. Fig. 8 denotes M a mold for vulcanizing the solid tire 10. In the above-described process for manufacturing the solid tire 10, as in Fig.Figure 8 shows the base material 13, consisting of a plastic film, on which the two-dimensional code 11 is printed, preferably arranged on a section of the unvulcanized tire 10X corresponding to a flat section of the mold M. A mold surface of the mold M has a complex shape. Therefore, if a section of the mold M with which the two-dimensional code 11 comes into contact during vulcanization is inclined or curved, there is a risk of misalignment or deformation of the two-dimensional code 11, rendering it unreadable. Therefore, by arranging the base material 13, made of plastic film, on which the two-dimensional code 11 is printed, on the section of the unvulcanized tire 10X corresponding to the flat section of the mold M, misalignment or deformation of the two-dimensional code 11 can be prevented.The flat section of shape M does not need to be precisely specified and any section can be chosen that does not cause positional misalignment or deformation of the two-dimensional code 11.

[0065] Fig. Figure 9 illustrates a method for manufacturing a solid tire according to a further embodiment of the present invention. In the method for manufacturing the solid tire 10 described above, as in Fig.Figure 9 shows the base material 13, consisting of a plastic film, on which the two-dimensional barcode 11 is printed, preferably arranged on a section of the unvulcanized tire 10X, excluding a start end 20s of the winding and a finish end 20e of the winding of the rubber strip 20. When the unvulcanized tire 10X is formed by winding the rubber strips 20 in several layers, gaps and irregularities form at the start and finish ends 20s of the winding of the rubber strips 20, and during vulcanization, rubber flow occurs due to these gaps and irregularities. Such rubber flow causes a positional misalignment of the two-dimensional code 11 and also leads to the two-dimensional code 11 being hidden in the rubber.Therefore, by arranging the base material 13, made of plastic film on which the two-dimensional barcode 11 is printed, on a section of the unvulcanized tire 10X, excluding the beginning and end 20s of the winding of the rubber strips 20, misalignment and burying of the two-dimensional code 11 can be prevented. A step can form at the end 20e of the winding not only on the sidewall but also on the tread surface of the unvulcanized tire 10X, and it is preferable to avoid arranging the base material in this section.

[0066] Fig. Figure 10 illustrates an unvulcanized tire and a mold in a method for manufacturing a solid tire according to yet another embodiment of the present invention. Fig. 10 designates M a form for vulcanizing the solid tire 10. In the production of the solid tire 10 described above, as in Fig.As shown in Figure 10, the unvulcanized tire 10X is formed by multi-layered winding of the rubber strips 20, while the base material 13, made of plastic film on which the two-dimensional code 11 is printed, can be arranged on the inside of the mold M. The unvulcanized tire 10X, together with the two-dimensional code 11, can then be vulcanized in the mold M. This allows the base material 13, on which the two-dimensional code 11 is printed, to be bonded to the outer surface of the solid tire 10 by vulcanization. The base material 13 is positioned so that the two-dimensional code 11 is in contact with the inner surface of the mold M.

[0067] In the case of the solid tire 10 described above, when arranging the base material 13 on the inner surface of the mold M, it is necessary to ensure that the base material 13 remains immobile during vulcanization. As a method for securing the base material 13, a recess can be formed in the inner surface of the mold M and the base material 13 inserted into the recess, or an adhesive can be applied to a portion of a surface (for example, the printed layer 12) of the base material 13 on the side of the mold M to temporarily attach the base material 13 to the mold M. In particular, the adhesive can be applied to a section where the two-dimensional code 11 is not present.If the base material 13, for example, has a rectangular shape, the two-dimensional code 11 is positioned longitudinally in a central section of it, with adhesive sections placed on both sides. This prevents the two-dimensional code 11 from becoming contaminated. It is also possible to utilize the recess formation and temporary fixation by the pressure-sensitive adhesive in combination. If the base material 13 is positioned on the side of the mold M as described above, positioning the two-dimensional code 11 is straightforward. In particular, if the base material 13 is attached to the mold M with a pressure-sensitive adhesive, the likelihood of misalignment and embedding of the two-dimensional code 11 during vulcanization is reduced.

[0068] In the present invention, the construction of the solid tire is not particularly limited, as long as the solid tire has the tread rubber layer on the road contact surface side and the base rubber layer on the rim side. For example, it is also possible to use a construction in which an additional reinforcing element made of steel, organic fibers, or high-hardness rubber is embedded in the solid tire, or a construction in which an additional cushioning element made of low-hardness rubber is embedded in the solid tire.

[0069] Fig. Figure 11 illustrates a solid tire according to yet another embodiment of the present invention. Fig.A solid tire 10 comprises a tread rubber layer 1 positioned on the road contact surface side, a base rubber layer 2 positioned on the rim side, a pair of bead cores 3 arranged on an outer side in the width direction of the base rubber layer 2, a side rubber layer 6 consisting of rubber extending radially from each bead core 3 to an outer side, and a fiber-reinforced layer 7 embedded in the side rubber layer 6 such that it extends radially from each bead core 3 to an outer side. An assembly consisting of the bead core 3, the side rubber layer 6, and the fiber-reinforced layer 7 is generally referred to as a sidewall. Furthermore, a cover rubber layer 8 is arranged on an outer side in the width direction of the sidewall composed of the bead core 3, the side rubber layer 6, and the fiber-reinforced layer 7. The side rubber layer 6 can be omitted.In this case, the facing fiber-reinforced layers 7 are directly bonded together. The presence or absence of the sidewall rubber layer 6 and the properties of the rubber are determined by the tire's size, performance, and other characteristics. In the solid tire 10 configured in this way, the two-dimensional code 11 can be arranged on the outer surface S, excluding the base surface B, which is in contact with the underside of the rim. The bead core 3 can also be embedded in the base rubber layer 2, in which case the rim slip suppression effect can be improved.

[0070] Fig. Figure 12 illustrates an unvulcanized tire during the process of manufacturing a Fig. 11 illustrated full tires. In Fig. 12 designates D a cylindrical mounting drum that can be extended and retracted. In the manufacture of the solid tire 10 described above, as in Fig.Figure 12 illustrates a rubber strip 20 being wound in several layers around the assembly drum D. Subsequently, the sidewalls, each composed of the bead core 3, the side rubber layer 6, and the fiber-reinforced layer 7, are attached to a multi-layered structure of the rubber strip 20 from both sides in the tire width direction. Furthermore, the cover rubber layers 8 are attached to the outside of this structure to form an unvulcanized tire 10X. Finally, the base material 13, consisting of a plastic film on which the two-dimensional code 11 is printed, is applied to the unvulcanized tire 10X.

[0071] In the embodiment described above, the base material 13, consisting of a plastic film onto which the two-dimensional code 11 is printed, is applied to the unvulcanized tire 10X. However, in the present invention, the two-dimensional code 11 can also be added to the solid tire 10 as a vulcanized product. For example, the two-dimensional code 11 can be printed onto the outer surface S of the solid tire 10 after vulcanization by sealing, laser processing, or burning in an identification mark. Since the two-dimensional code 11 is printed directly onto the product, the adhesion of the base material 13 to the two-dimensional code 11 and the rubber flow during vulcanization do not need to be considered.When providing a large number of two-dimensional codes 11, the method described above and the method using the base material 13 made from a plastic film can be combined.

[0072] The two-dimensional code 11 can also be printed onto the outer surface S of the solid tire 10 by means of a serial number plate arranged in a mold. That is, instead of the method in which the base material 13, consisting of a plastic film onto which the two-dimensional code 11 is printed, is glued on as described above, a system is used in which a metallic serial number plate can be attached to a mold and the two-dimensional code 11 is pre-engraved onto the serial number plate. This allows the pattern of the two-dimensional code 11 to be formed on the product by vulcanization in the mold. Since the two-dimensional code 11 is printed directly onto the product, the adhesion of the base material 13 to the two-dimensional code 11 and the rubber flow during vulcanization do not need to be taken into account.When providing a large number of two-dimensional codes 11, the method described above and the method using the base material 13 made from a plastic film can be combined.

[0073] The two-dimensional code 11 is preferably provided near the sidewall of the solid tire 10, which, when the solid tire is mounted on the vehicle, is located on the outside of the vehicle. Providing the two-dimensional code 11 on the sidewall located on the outside of the vehicle when the solid tire is mounted in this way makes the two-dimensional code 11 easily verifiable. If the two-dimensional codes 11 are arranged at a plurality of positions spaced 180° apart or at a plurality of positions spaced 90° apart in the circumferential direction of the tire, other two-dimensional codes 11 can be verified even if one two-dimensional code 11 is obscured by the machine base.In this case, the advantage is that even if one two-dimensional barcode becomes unreadable due to a scratch or dirt, the other two-dimensional codes can still be read. Example

[0074] Several types of test tires (Comparison Example 1 and Examples 1 to 7) were manufactured for air cushion tires for industrial vehicles with a tire size of 5.00-8 and a road-contact-side tread rubber layer and a rim-side base rubber layer. In the test tires, a base material with a two-dimensional code printed on it was bonded to the tire via an adhesion promoter layer and a primer layer, with the position of the two-dimensional code being varied.

[0075] In comparative example 1 and examples 1 to 7, the base rubber layer compound, the JIS-A hardness of the tread rubber layer, the JIS-A hardness of the base rubber layer, and the position of the two-dimensional code are as shown in Table 1. A polyethylene terephthalate resin base material with dimensions of 8 mm × 20 mm × 140 µm thickness was used as the base material for the two-dimensional code.

[0076] A 20 µm thick adhesive layer was obtained by applying a solution in which 100 parts by weight of natural rubber, 35 parts by weight of petroleum-based resin, 4 parts by weight of thiuram-based vulcanization accelerator (Nocceler TRA, available from Ouchi Shinko Chemical Industrial Co., Ltd.) and 3 parts by weight of phenol-based anti-aging agent were uniformly dissolved in 200 parts by weight of toluene, followed by drying at 140°C for 2 minutes. A 5 µm thick primer layer was applied by means of a mixture containing 100 parts by weight of a chlorophenol-based primer, 4.0 parts by weight of resorcinol, 3.8 parts by weight of formaldehyde, 47.9 parts by weight of vinylpyridine latex (solids content: 41 wt.%), 12.0 parts by weight of SBR latex (solids content: 40 wt.%), and 6.8 parts by weight of a 5 wt.-% sodium hydroxide solution was evenly mixed with 27.1 parts by weight of soft water, and subsequently dried for 2 minutes at 150°C. The positions of the two-dimensional codes were (A) the position of the base surface, (B) the position on the side surface of the tread rubber layer, (C) the position on the side surface of the base rubber layer on the outside of the rim flange's apex in the tire radial direction (position outside the rim friction zone), (D) the position on the side surface of the base rubber layer corresponding to the rim flange's apex, (E) the position on the side surface of the base rubber layer corresponding to 45% of the rim flange's height, and (F) the position on the side surface of the base rubber layer corresponding to 25% of the rim flange's height.

[0077] The test tires were subjected to the following real-world vehicle test. Specifically, the test tire was mounted on an 8 × 3.00D rim, which was then mounted on each of the left and right rear wheels of a forklift. The forklift was then driven for 100 hours with a 500 kg load at a speed of 8.8 km / h on a test track with a dry, flat, concrete surface. The test track is located in Fig.The illustrated circuit has a circumference of 56 m. The test was conducted discontinuously with a driving time of 5 hours per day. After completion of the test, the abrasion and delamination of the two-dimensional code were evaluated. Regarding abrasion, a case where reading was possible and the wear was low was indicated by "⊚", a case where reading was possible was indicated by "◯", a case where reading was difficult due to abrasion was indicated by "Δ", and a case where reading was impossible due to abrasion was indicated by "×". The results are listed in Table 1. Regarding delamination, the area ratio of the delamination occurring in the base material of the two-dimensional code was measured. Table 1 Mixture of the base rubber layer comparative example Example Example Example Example Example Example Example 1 1 2 3 4 5 6 7 natural rubber 45 45 45 45 45 45 45 45 SBR1500 55 55 55 55 55 55 55 55 Oil-modified phenolic resin 7 7 7 7 7 7 4 10 Soot (N330) 82 82 82 82 82 82 82 82 Stearic acid 2 2 2 2 2 2 2 2 zinc oxide 5 5 5 5 5 5 5 5 Age-retardant agent (6PPD) 2 2 2 2 2 2 2 2 wax 1 1 1 1 1 1 1 1 Aroma oil 11 11 11 11 11 11 11 11 sulfur 2,5 2,5 2,5 2,5 2,5 2,5 2,5 2,5 Vulcanization accelerator (CBS) 1 1 1 1 1 1 1 1 Hexamethylenetetramine 0,7 0,7 0,7 0,7 0,7 0,7 0,4 1,0 JIS-A hardness of tread rubber 63 63 63 63 63 63 63 63 JIS-A hardness of the base rubber layer 80 80 80 80 80 80 76 84 Position of the two-dimensional code A B C D E F F F abrasion × ⊚ ⊚ Δ ◯ ◯ ◯ ◯ Replacement (%) 50 5 3 10 2 2 4 1

[0078] As can be seen from Table 1, the tires in examples 1 to 7 showed less abrasion and detachment of the two-dimensional code after the test. On the other hand, abrasion and detachment of the two-dimensional code were significant in the tire of comparison example 1 after the test.

[0079] Next, short fibers were mixed into the rubber compound forming the base rubber layer of the tire in Example 5, and several test tire types (Examples 11 to 20) were produced, varying the amount of short fibers mixed in. The short fibers used were either a Vinalon fiber (Vinalon Fiber 1) with a fiber length of 4 mm and a fiber diameter of 12 µm or a Vinalon fiber (Vinalon Fiber 2) with a fiber length of 8 mm and a fiber diameter of 50 µm.

[0080] In Examples 11 to 20, the base rubber compound, the JIS-A hardness of the tread rubber layer, the JIS-A hardness of the base rubber layer, the modulus at 10% elongation of the base rubber layer, and the position of the two-dimensional code are as listed in Table 2. The modulus at 10% elongation of the base rubber layer was measured by vulcanizing an unvulcanized rubber strip at 155°C for 30 minutes using an autograph available from Shimadzu Corporation according to JIS K6251 with a Type 1 dumbbell at a speed of 100 mm / minute.

[0081] The test tires were subjected to an actual vehicle test, and the abrasion and peeling caused by the two-dimensional code were evaluated as described above. The results are listed in Table 2. [Table 2-I] Mixture of the base rubber layer Example 11 Example 12 Example 13 Example 14 Example 15 natural rubber 45 45 45 45 45 SBR1500 55 55 55 55 55 Oil-modified phenolic resin 7 7 7 7 7 Soot (N330) 82 82 82 82 82 Stearic acid 2 2 2 2 2 zinc oxide 5 5 5 5 5 Aging retardant (6PPD) 2 2 2 2 2 wax 1 1 1 1 1 Aroma oil 11 11 11 11 11 Vinalon fiber 1 0,5 1 5 10 12 Vinalon fiber 2 - - - - - sulfur 2,5 2,5 2,5 2,5 2,5 Vulcanization Accelerator (CBS) 1 1 1 1 1 Hexamethylenetetramine 0,7 0,7 0,7 0,7 0,7 JIS-A hardness of tread rubber 63 63 63 63 63 JIS-A hardness of the base rubber layer 80 80 80 81 81 Modulus (MPa) at 10% elongation of the base rubber layer 2,1 2,4 3,1 4,7 5,7 Position of the two-dimensional code F F F F F abrasion ◯ ⊚ ⊚ ⊚ ⊚ Replacement (%) 2 1 1 1 1 [Table 2-II] Mixture of the base rubber layer Example 16 Example 17 Example 18 Example 19 Example 20 natural rubber 45 45 45 45 45 SBR1500 55 55 55 55 55 Oil-modified phenolic resin 7 7 7 7 7 Soot (N330) 82 82 82 82 82 Stearic acid 2 2 2 2 2 zinc oxide 5 5 5 5 5 Aging retardant (6PPD) 2 2 2 2 2 wax 1 1 1 1 1 Aroma oil 11 11 11 11 11 Vinalon fiber 1 - - - - - Vinalon fiber 2 0,5 1 5 10 12 sulfur 2,5 2,5 2,5 2,5 2,5 Vulcanization Accelerator (CBS) 1 1 1 1 1 Hexamethylenetetramine 0,7 0,7 0,7 0,7 0,7 JIS-A hardness of tread rubber 63 63 63 63 63 JIS-A hardness of the base rubber layer 80 80 80 81 81 Modulus (MPa) at 10% elongation of the base rubber layer 2,2 2,6 3,5 5,1 6,2 Position of the two-dimensional code F F F F F abrasion ◯ ⊚ ⊚ ⊚ ⊚ Replacement (%) 2 1 1 1 1

[0082] As can be seen from Table 2, the tires in examples 11 to 20 showed less abrasion and detachment of the two-dimensional code after the test.

[0083] Next, several types of test tires (Examples 21 to 25) were produced for the tire from Example 5, varying the thickness of the primer layer. Example 23 is the same as Example 5.

[0084] In Examples 21 to 25, the base rubber compound, the JIS-A hardness of the tread rubber layer, the JIS-A hardness of the base rubber layer, the primer layer thickness, the adhesion of the base material to the tire's outer surface, and the position of the two-dimensional code are as listed in Table 3. The adhesion of the base material to the tire's outer surface is measured by layering an unvulcanized rubber strip of the same rubber compound as the tire's outer surface and the base material. Vulcanization is performed for 30 minutes at 155°C, and a 180° pull-off test is conducted according to JIS Z0237 using an autograph available from Shimadzu Corporation.

[0085] The test tires were subjected to an actual vehicle test, and the abrasion and peeling caused by the two-dimensional code were evaluated as described above. The results are listed in Table 3. [Table 3] Mixture of the base rubber layer Example 21 Example 22 Example 23 Example 24 Example 25 natural rubber 45 45 45 45 45 SBR1500 55 55 55 55 55 Oil-modified phenolic resin 7 7 7 7 7 Soot (N330) 82 82 82 82 82 Stearic acid 2 2 2 2 2 zinc oxide 5 5 5 5 5 Aging retardant (6PPD) 2 2 2 2 2 wax 1 1 1 1 1 Aroma oil 11 11 11 11 11 sulfur 2,5 2,5 2,5 2,5 2,5 Vulcanization Accelerator (CBS) 1 1 1 1 1 Hexamethylenetetramine 0,7 0,7 0,7 0,7 0,7 JIS-A hardness of tread rubber 63 63 63 63 63 JIS-A hardness of the base rubber layer 80 80 80 80 80 Primer layer thickness (µm) 1,5 2 5 14 25 Bond strength of the base material (N / 10 mm) 49 60 66 71 76 Position of the two-dimensional code F F F F F abrasion ◯ ◯ ◯ ◯ ◯ Replacement (%) 5 3 2 1 1

[0086] As can be seen from Table 3, the tires of examples 21 to 25 showed less abrasion and detachment of the two-dimensional code after the test. List of reference symbols 1 tread rubber layer 2 Base rubber layer 3 bead core 4 Intermediate rubber layer 5 Short fiber 10 solid tires 10X Unvulcanized Tire 11 Two-dimensional code 12 Printed Layers 13 Basic material 14 Adhesive layer 15 Primer layer 20 rubber strips 21 Primer layer R rim F rim horn B Base surface S Outer 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 H10-147107 A

[0004] JP 2010-163123 A

[0004] JP 2016-117296 A

[0004]

Claims

[1] Solid tires, including: a tread rubber layer on the road contact surface; and a base rubber layer on the rim side; a two-dimensional code that is arranged on an outer surface of the solid tire, excluding a base surface thereof that is in contact with a rim underside. [2] Solid tire according to claim 1, wherein the two-dimensional code is arranged at a position outside a rim friction area, which is defined as being within a range of -15% to +15% of a rim flange height with a vertex of a rim flange as the center. [3] Solid tire according to claim 2, wherein the two-dimensional code is arranged on an inside in the tire radial direction from the apex of the rim flange. [4] Solid tire according to claim 3, wherein the two-dimensional code is arranged in a range of 0% to 45% of the rim flange height. [5] Solid tires according to any one of claims 1 to 4, wherein the two-dimensional code is arranged on the base rubber layer and the base rubber layer has a JIS-A hardness of 80 or more. [6] Solid tires according to claim 5, wherein short fibers are mixed into a rubber or rubber composition forming the base rubber layer. [7] Solid tire according to one of claims 1 to 6, wherein a base material made of a plastic film, on which the two-dimensional code is printed, is bonded to the outer surface via an adhesive layer. [8] Solid tires according to claim 7, wherein the rubber layer in a section to which the base material is bonded contains at least 30 phr of natural rubber and sulfur as a vulcanizing agent, and the adhesive layer consists of a pressure-sensitive adhesive based on natural rubber, that contains only a vulcanization accelerator without vulcanizing agent. [9] Solid tires according to claim 7 or 8, wherein the adhesion strength between the outer surface and the base material is 60 N / 10 mm or more. [10] Solid tires according to one of claims 7 to 9, wherein a primer layer of resorcinol-formaldehyde latex is arranged between the adhesive layer and the base material. [11] Method for producing the solid tire described in any one of claims 1 to 10, the method comprising: Forming an unvulcanized tire by wrapping a strip of rubber in several layers; the application of a base material made of a plastic film, onto which the two-dimensional code is printed, to the unvulcanized tire; and then Vulcanizing the unvulcanized tire with the two-dimensional code in a mold. [12] Method for producing a solid tire according to claim 11, the method comprising: Applying a base layer of unvulcanized rubber with a thickness of 0.5 mm to 10 mm to a surface of the unvulcanized tire and Overlapping and fastening the base material made of plastic film, onto which the two-dimensional code is printed, to the base layer. [13] Method for producing a solid tire according to claim 11 or Claim 12, comprising the method: Arranging the base material from the plastic film, onto which the two-dimensional code is printed, on a section of the unvulcanized tire that corresponds to a flat section of the mold. [14] Method for producing a solid tire according to one of claims 11 to 13, comprising arranging the base material from the plastic film on which the two-dimensional barcode is printed on a section of the unvulcanized tire excluding the beginning and end ends of the winding of the rubber strip. [15] Method for producing the solid tire described in any one of claims 1 to 10, the method comprising: Forming an unvulcanized tire by wrapping a strip of rubber in several layers; Meanwhile, arranging a base material consisting of a plastic film, onto which the two-dimensional code is printed, on an inner surface of a mold; and Vulcanizing the unvulcanized tire along with the two-dimensional code in the mold.

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