Rubber reinforcing material with reduced weight, process for its preparation and tyre comprising the same

Abstract

The present invention relates to a rubber reinforcing material having reduced weight, a method for producing the same, and a tire including the rubber reinforcing material. According to the present invention, a rubber reinforcing material having a thin thickness and light weight but having excellent durability is provided. The reinforcing material not only reduces the weight of the tire, but also enables improved rolling resistance.

Description

Technical Field

[0001] The present invention relates to a weight-reducing rubber reinforcement material, a method for preparing the same, and a tire comprising such a rubber reinforcement material. Background Technology

[0002] With improvements in vehicle performance and road conditions, tires are required to maintain stability and durability during high-speed driving. Furthermore, considering environmental, energy, and fuel efficiency concerns, tires that are lightweight yet possess excellent durability are needed. As one solution to meet these requirements, research is actively underway on tire cords, the rubber reinforcing materials used in tires.

[0003] Tire cords can be categorized based on their location and function. For example, tire cords can be primarily divided into the tire carcass, which typically supports the tire; the belt layer, which bears the load and prevents deformation due to high-speed driving; and the crown belt layer, which prevents deformation of the belt layer (see [link to product description]). Figure 1 ).

[0004] Examples of materials used for tire cords include nylon, rayon, aramid, and polyester.

[0005] Typically, tire cords are rolled together with the rubber component to bond with the rubber. That is, a rolling process is involved in tire manufacturing. However, using a rolling process to bond the tire cords and rubber during tire manufacturing increases process costs, and due to rolling, the tire density increases beyond what is needed, thus unnecessarily increasing the tire's weight.

[0006] Solid rubber is typically used in the process of rolling rubber into tire cords. However, it is difficult to prepare products formed by rolling solid rubber into film form with a thickness of less than 200 μm, especially 5 μm to 30 μm, and the thickness and weight of the tire increase when such products are used as rubber reinforcement materials.

[0007] Recently, tire manufacturers have been trying to reduce the thickness of the rubber layers to achieve ultra-lightweight tires and lighter reinforcing materials. Rolling resistance (R / R) is related to tire weight and has a significant impact on vehicle fuel consumption and CO2 emissions. For example, when rolling resistance (R / R) is high, the energy required for vehicle operation increases. Furthermore, the resistance to vehicle rotation, gradient, and acceleration is related to vehicle weight. Therefore, research is underway to reduce vehicle weight by reducing tire weight, thereby reducing energy consumption. Summary of the Invention

[0008] Technical issues

[0009] One object of the present invention is to provide a rubber-reinforced material having a thin thickness but excellent durability.

[0010] Another object of the present invention is to provide a method for preparing a rubber-reinforced material with thin thickness but excellent durability.

[0011] Another object of the present invention is to provide a tire comprising the rubber reinforcing material.

[0012] Technical solution

[0013] According to one embodiment of the present invention, a rubber reinforcing material is provided, comprising:

[0014] Fiber substrate;

[0015] An adhesive layer located on the fiber substrate; and

[0016] The rubber compound layer located on the adhesive layer,

[0017] The fiber substrate is a fabric woven from warp and weft yarns.

[0018] The warp yarns are single-ply yarns with a fineness of 420 denier to 800 denier, and are included in the fabric with a warp density of 55 / inch to 65 / inch.

[0019] According to the standard test method of ASTM D 885 (177°C, 2 minutes, load of 0.05 g / de), the dry heat shrinkage of the weft yarn is -1.0% to +3.0%.

[0020] According to another embodiment of the present invention, a method for preparing a rubber-reinforced material is provided, comprising the following steps:

[0021] Prepare a fiber substrate using warp yarns of 420 to 800 denier fineness and weft yarns of -1.0% to +3.0% dry heat shrinkage according to the standard test method of ASTM D 885 (177°C, 2 minutes, load of 0.05 g / de) at a warp density of 55 to 65 / inch.

[0022] An adhesive layer is formed on the fiber substrate; and

[0023] A rubber coating solution is applied to the adhesive layer and then heat-treated to form a rubber composite layer on the adhesive layer.

[0024] According to another embodiment of the present invention, a tire comprising the said rubber reinforcing material is provided.

[0025] The following will describe in detail the rubber reinforcement material according to embodiments of the present invention, its preparation method, and the tire including the rubber reinforcement material.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of effectively explaining particular embodiments only and is not intended to limit the invention.

[0027] Singular expressions include their plural expressions unless explicitly stated or clearly indicated from the context.

[0028] As used herein, the term "comprising" is intended to indicate the presence of features, quantities, steps, structural elements, or combinations thereof in the implementation, and is not intended to exclude the possibility of the presence or addition of one or more other features, quantities, steps, structural elements, or combinations thereof.

[0029] Although various modifications can be made to the invention and the invention can take many forms, specific examples will be described and explained in detail below. However, it should be understood that these are not intended to limit the invention to the specific disclosure, and the invention includes all modifications, equivalents, or substitutions thereto without departing from its spirit and scope.

[0030] When the positional relationship between two components is explained by terms such as "above," "on top," "below," "beside," etc., other components may be located between these two components, unless the terms "exactly" or "directly" are used.

[0031] When time series are described using terms such as “after,” “then,” “next,” or “before,” discontinuous cases may be included, unless the expressions “exactly” or “directly” are used.

[0032] The term "at least one" should be understood to include all combinations in which one or more related items may exist.

[0033] 1. Rubber reinforced materials

[0034] According to one embodiment of the present invention, a rubber reinforcing material is provided, comprising:

[0035] Fiber substrate;

[0036] An adhesive layer located on the fiber substrate; and

[0037] The rubber compound layer located on the adhesive layer,

[0038] The fiber substrate is a fabric woven from warp and weft yarns.

[0039] The warp yarns are single-ply yarns with a fineness of 420 denier to 800 denier, and are included in the fabric with a warp density of 55 / inch to 65 / inch.

[0040] According to the standard test method of ASTM D 885 (177°C, 2 minutes, load of 0.05 g / de), the dry heat shrinkage of the weft yarn is -1.0% to +3.0%.

[0041] As a result of the inventors’ continuous research, it has been confirmed that the rubber-reinforced material including the fiber substrate has a thin thickness but exhibits excellent durability.

[0042] Furthermore, because the rubber reinforcing material of the above embodiment has excellent adhesion strength to rubber, it can bond firmly to rubber during tire manufacturing without a rolling process. Therefore, the rubber reinforcing agent can reduce tire manufacturing costs and prevent unnecessary increases in tire density and weight due to rolling.

[0043] Because the rubber reinforcement material has excellent bonding strength with rubber, air pockets can be reduced during the manufacturing of green tires, thereby reducing the tire defect rate.

[0044] Because of its thin thickness, the rubber reinforcement material meets the requirement of reducing the thickness of the rubber layer for ultra-lightweight tires. Furthermore, the rubber reinforcement material can reduce rolling resistance and improve fuel efficiency in automobiles. In particular, it can improve the fuel efficiency and driving performance of electric vehicles.

[0045] Figure 2 This is a schematic cross-sectional view of a rubber-reinforced material (201) according to an embodiment of the present invention.

[0046] The rubber reinforcement material (201) includes: a fiber substrate (210), an adhesive layer (220) on the fiber substrate (210), and a rubber composite layer (230) on the adhesive layer (220).

[0047] According to one embodiment of the invention, the fiber substrate is a fabric woven from warp and weft yarns.

[0048] In the fiber substrate, the warp and weft yarns may each comprise one or more materials selected from nylon, rayon, aramid, polyester, and cotton.

[0049] Preferably, the warp yarn may comprise one or more materials selected from nylon, rayon, aramid, and polyester. More preferably, the weft yarn may comprise one or more materials selected from nylon, rayon, aramid, polyester, and cotton.

[0050] In particular, the fiber substrate (210) has a high density in the warp direction.

[0051] Specifically, the warp yarn is a single-ply yarn with a fineness of 420 denier to 800 denier and is included in the fabric with a warp density of 55 / inch to 65 / inch.

[0052] Preferably, the warp density of the fiber substrate is 55 / inch or more, so that the rubber reinforcement (201) can have a thin thickness but exhibit excellent durability.

[0053] If the warp density is too high, it will be difficult to arrange the warp yarns evenly. Furthermore, due to the overlapping of misaligned warp yarns, wrinkles will form on the fiber substrate, and these wrinkles will cause the fiber substrate's properties to become uneven. Therefore, preferably, the warp density of the fiber substrate is 65 / inch or less.

[0054] The warp yarn is a single strand, and its fineness can be determined taking into account the warp density. However, to ensure the durability of the fiber base, the warp yarn fineness is preferably 420 denier or higher.

[0055] Preferably, the density between warp yarns of the fiber substrate is 65% or more.

[0056] The density between warp yarns represents the area occupied by warp yarns per inch. Specifically, it can be expressed as {(fineness of one warp yarn (inches) * number of warp yarns per inch (n)) / inch} * 100 (%).

[0057] Specifically, the density between warp yarns can be 65% or more, or 75% or more, or 90% or more. When the density between warp yarns is 65% or more, the desired effect of the present invention can be fully achieved.

[0058] The warp yarns can be twisted. The twist of the warp yarns can range from 0 to 250 TPM (twist per meter). Twisting the warp yarns can improve the cohesiveness and fatigue resistance of the fiber matrix.

[0059] When the fiber substrate (210) comprises highly dense warp yarns, it also comprises weft yarns that enable the warp yarns to be evenly aligned.

[0060] Specifically, preferably, the dry heat shrinkage of the weft yarn is -1.0% to +3.0% according to the standard test method of ASTM D 885 (177°C, 2 minutes, load of 0.05 g / de).

[0061] Here, a value of (+) for the dry heat shrinkage rate indicates shrinkage behavior, while a value of (-) indicates relaxation behavior.

[0062] During the manufacturing process of the rubber-reinforced material, a predetermined amount of heat is applied to the fiber substrate. Here, in the fiber substrate, weft shrinkage occurs due to stretching and heat in the warp direction. However, since the fiber substrate comprises highly dense warp yarns, wrinkles are generated on the fiber substrate due to the overlapping of misaligned warp yarns. These wrinkles inhibit the proper formation of the adhesive layer (220) and the rubber composite layer (230) sequentially located on the fiber substrate (210).

[0063] According to an embodiment of the invention, since the dry heat shrinkage rate of the weft yarns included in the fiber substrate (210) is ±0.5% according to the standard test method of ASTM D 885 (177°C, 2 minutes, load of 0.05 g / de), the overlap of the warp yarns can be effectively suppressed.

[0064] The dry heat shrinkage rate of the weft yarn was measured according to the standard test method of ASTM D 885. The test was performed by applying a load of 0.05 g / de to a weft yarn sample (60 cm in length), heating it at 177°C for 2 minutes, and then measuring the change in the length of the weft yarn sample.

[0065] Preferably, according to the standard test method of ASTM D 885 (177°C, 2 minutes, load of 0.05 g / de), the dry heat shrinkage rate of the weft yarn can be -1.0% to +3.0%, or -1.0% to +2.0%, or -0.5% to +2.0%, or -0.5% to +1.5%, or -0.5% to +1.0%, or -0.50% to +0.50%, or -0.40% to +0.50%, or -0.40% to +0.40%, or -0.30% to +0.40%, or -0.30% to +0.30%, or -0.20% to +0.30%.

[0066] According to an embodiment of the present invention, the weft yarn is a single-ply yarn with a fineness of 420 denier to 800 denier.

[0067] The weft yarn may be included in the fabric with a weft density of 0.05 / mm to 5 / mm, or 0.05 / mm to 4.5 / mm, or 0.05 / mm to 4 / mm, or 0.05 / mm to 3.5 / mm, or 0.05 / mm to 3 / mm, or 0.05 / mm to 2.5 / mm.

[0068] The thickness of the fiber substrate (201) can be from 100 μm to 600 μm, or from 200 μm to 500 μm, or from 200 μm to 400 μm. Within the above thickness range, the fiber substrate can have excellent durability.

[0069] According to the standard test method of ASTM D 885 (specimen size: 60 cm in length and 1 cm in width in the weft direction, 177°C, 2 minutes, based on a weft load of 0.05 g / de), the dry heat shrinkage rate of the fiber substrate can be from -1.0% to +3.0%. Here, a dry heat shrinkage rate value of (+) indicates shrinkage behavior, and a dry heat shrinkage rate value of (-) indicates relaxation behavior.

[0070] The dry heat shrinkage rate of the fiber substrate was measured according to the standard test method of ASTM D 885. The test was performed by applying a load of 0.05 g / de based on the weft fineness to the fiber substrate specimen (60 cm in length and 1 cm in width in the weft direction), heating it at 177°C for 2 minutes, and then measuring the changes in the length and width of the fiber substrate specimen.

[0071] Preferably, according to the ASTM D 885 standard test method (sample size: 60cm length × 1cm width in the weft direction, 177°C, 2 minutes, based on a weft load of 0.05g / de), the dry heat shrinkage rate of the fiber substrate can be -1.0% to +3.0%, or -1.0% to +2.0%, or -0.5% to +2.0%, or -0.5% to +1.5%, or -0.5% to +1.0%, or -0.50% to +0.50%, or -0.40% to +0.50%, or -0.40% to +0.40%, or -0.30% to +0.40%, or -0.30% to +0.30%.

[0072] Meanwhile, the rubber reinforcement material (201) includes an adhesive layer (220) located on the fiber substrate (210).

[0073] The adhesive layer comprises resorcinol-formaldehyde-latex (RFL).

[0074] For example, the adhesive layer (220) can be formed by an adhesive coating solution containing resorcinol-formaldehyde-latex (RFL) and a solvent.

[0075] Resorcinol-formaldehyde-latex acts as an adhesive component. Resorcinol-formaldehyde-latex improves the affinity and adhesive strength, particularly between the fiber substrate (210) and the rubber component. Therefore, the adhesive layer (220) improves the internal adhesive strength between the fiber substrate (210) and the rubber composite layer (230), and also improves the external adhesive strength between the rubber reinforcement (201) and the rubber (e.g., tread).

[0076] Therefore, the fiber substrate (210) and the rubber compound layer (230) can be stably bonded to each other without separating, thereby reducing the defect rate in the manufacturing process of the tire (101).

[0077] Meanwhile, the rubber reinforcing material (201) includes a rubber composite layer (230) located on the adhesive layer (220).

[0078] The rubber composite layer (230) may include one or more elastic polymers selected from natural rubber and synthetic rubber.

[0079] The rubber composite layer (230) can be formed by coating a liquid rubber coating solution containing an elastic polymer onto the adhesive layer (220). Therefore, the rubber reinforcement (201) can have a thin rubber composite layer (230), a thickness that is difficult to achieve using a rolling process with solid rubber. Due to the reduced thickness of the rubber composite layer (230), it can contribute to weight reduction in both the rubber reinforcement (201) it comprises and the tire comprising the rubber reinforcement (201).

[0080] Specifically, the rubber composite layer (230) may be formed from a rubber coating solution comprising an elastic polymer composition and a solvent.

[0081] The elastic polymer composition may contain an elastic polymer and additives.

[0082] The elastic polymer can be one or more rubbers selected from natural rubber and synthetic rubber. For example, the elastic polymer can be one or more rubbers selected from natural rubber (NR), styrene-butadiene rubber (SBR), cis-butadiene rubber (BR), chloroprene rubber (CR), isobutylene rubber (IBR), isoprene rubber (IR), nitrile rubber (NBR), butyl rubber, and chloroprene rubber.

[0083] Additives that can be included in elastic polymer compositions include carbon black, para oil, zinc oxide, stearic acid, anti-aging agents, sulfur, vulcanization accelerators, activators, pressure-sensitive adhesives, and adhesives.

[0084] There are no particular restrictions on the types of solvents contained in the rubber coating solution, as long as they can dissolve the elastic polymer. For example, the solvent may include at least one selected from toluene, naphtha, methanol, xylene, and tetrahydrofuran.

[0085] Based on the total weight of the rubber coating solution, the rubber coating solution may contain 10% to 40% by weight of an elastic polymer composition and 60% to 90% by weight of a solvent.

[0086] If the concentration of the elastic polymer composition in the rubber coating solution is too low, the thickness of the rubber composite layer will become too thin and will not exhibit the required pressure-sensitive adhesive strength and bond strength. Therefore, preferably, the rubber coating solution contains more than 10% by weight of the elastic polymer composition.

[0087] However, if the concentration of the elastic polymer composition in the rubber coating solution is too high, the stirring performance of the rubber coating solution will deteriorate due to increased viscosity, and the dispersion performance of the components will decrease, thus deteriorating the coating performance and causing the coating thickness to become uneven. Therefore, preferably, the rubber coating solution contains less than 40% by weight of the elastic polymer composition.

[0088] The thickness (t1) of the rubber composite layer (230) can be 5 μm to 200 μm, or 5 μm to 150 μm, or 5 μm to 100 μm, or 5 μm to 50 μm.

[0089] like Figure 2 As shown, the thickness of the rubber compound layer (230) is measured as the longest distance from one side of the rubber compound layer (230) adjacent to the adhesive layer (220) to the other side of the rubber compound layer (230) located on the opposite side of the adhesive layer (220).

[0090] In existing rubber-reinforced materials, a rubber substrate is rolled onto a fiber substrate to form a rubber layer. Therefore, the thickness of the rubber layer is usually 1 mm or more, or at least 0.8 mm or more.

[0091] Conversely, since the rubber composite layer (230) is formed from a rubber coating solution, it can have a thickness of less than 200 μm. Therefore, the total thickness of the rubber reinforcement material (201) will be thinner, and in addition, the thickness of the tire (101) including the rubber reinforcement material (201) will be thinner.

[0092] If the rubber compound layer (230) is too thin, it will not have sufficient pressure-sensitive adhesive strength and bond strength, thus increasing the defect rate during tire manufacturing and degrading tire durability. Therefore, preferably, the thickness of the rubber compound layer (230) is 5 μm or more.

[0093] However, if the rubber composite layer (230) is too thick, it is not suitable for the present invention to provide a rubber reinforcement material (201) with a thin thickness. In particular, if the rubber composite layer (230) is too thick, bubbles will form in the rubber composite layer (230) during solvent evaporation, making it difficult for the rubber reinforcement material (201) to have a uniform thickness. Furthermore, cavitation will occur in tires using it, thus deteriorating tire quality and increasing the defect rate. Moreover, multiple coating operations are required to form a thick rubber composite layer (230), thus reducing process efficiency. Therefore, preferably, the thickness (t1) of the rubber composite layer (230) is 200 μm or less.

[0094] Meanwhile, according to the standard test method of ASTM D 885 (specimen size: 60cm length × 1cm width in the weft direction, 150°C, 2 minutes, load of 10g), the dry heat shrinkage of the rubber reinforcement material (201) according to the above embodiment can be -4% to -2%.

[0095] The dry heat shrinkage rate of rubber-reinforced materials is measured according to the standard test method of ASTM D 885. A load of 10g is applied to a rubber-reinforced material specimen (60cm in length and 1cm in width in the weft direction), heated at 150°C for 2 minutes, and then the changes in the length and width of the rubber-reinforced material specimen are measured.

[0096] In a tensile test of a specimen (size: 25cm in length and 1cm in width in the weft direction) at 150°C, the rubber reinforcement material (201) according to the above embodiment can exhibit a maximum load of 1.0kgf to 1.2kgf or 1.1kgf to 1.2kgf.

[0097] In a tensile test of a specimen (size: 25cm in length and 1cm in width in the weft direction) at 160°C, the rubber reinforcement (201) can exhibit a maximum load of 1.0kgf to 1.2kgf or 1.0kgf to 1.1kgf.

[0098] In a tensile test of a specimen (size: 25cm in length and 1cm in width in the weft direction) at 177°C, the rubber reinforcement (201) can exhibit a maximum load of 0.8kgf to 1.1kgf or 0.9kgf to 1.1kgf.

[0099] Furthermore, in a tensile test of a specimen (size: 25cm in length and 1cm in width in the weft direction) at 150°C, the tensile strain of the rubber reinforcement material (201) according to the above embodiment can be 11.0% to 13.0% or 11.0% to 12.0%.

[0100] In a tensile test of a specimen (size: 25cm in length and 1cm in width in the weft direction) at 160°C, the tensile strain of the rubber reinforcement material (201) can be 13.0% to 15.0% or 14.0% to 15.0%.

[0101] In a tensile test of a specimen (size: 25cm in length and 1cm in width in the weft direction) at 177°C, the tensile strain of the rubber reinforcement material (201) can be 13.0% to 15.0% or 14.0% to 15.0%.

[0102] Tensile testing can be performed using a half-chamber, taking into account the structure of the rubber reinforcement. In a conventional high-temperature chamber, the entire specimen is placed inside, heated, and left at the high temperature for a certain period before evaluating tensile properties. However, the rubber reinforcement has a formed rubber composite layer (230) on its exterior, making it difficult to measure properties when using a conventional high-temperature chamber due to slippage of the gripping portion caused by the high temperature. Therefore, it is preferable to use a half-chamber capable of heating only the middle portion of the rubber reinforcement specimen for tensile testing.

[0103] The rubber reinforcement material (201) according to the above embodiment can be applied to at least one of the crown layer (90), belt layer (50) and carcass (70) of a tire.

[0104] II. Preparation methods of rubber-reinforced materials

[0105] According to another embodiment of the present invention, a method for preparing a rubber-reinforced material is provided, comprising the following steps:

[0106] Prepare a fiber substrate using warp yarns of 420 to 800 denier fineness and weft yarns of -1.0% to +3.0% dry heat shrinkage according to the standard test method of ASTM D 885 (177°C, 2 minutes, load of 0.05 g / de) at a warp density of 55 to 65 / inch.

[0107] An adhesive layer is formed on the fiber substrate; and

[0108] A rubber coating solution is applied to the adhesive layer and then heat-treated to form a rubber composite layer on the adhesive layer.

[0109] A fiber base (210) woven at a warp density of 55 / inch to 65 / inch was prepared using warp yarns of 420 denier to 800 denier fineness and weft yarns of -1.0% to +3.0% dry heat shrinkage according to the standard test method of ASTM D 885 (177°C, 2 minutes, load of 0.05 g / de).

[0110] For details regarding the fiber substrate (210), please refer to the explanation in "I. Rubber Reinforced Materials".

[0111] The step of forming an adhesive layer (220) on a fiber substrate (210) is performed.

[0112] The adhesive layer (220) can be formed by an adhesive coating solution containing resorcinol-formaldehyde-latex (RFL) and a solvent.

[0113] For example, the adhesive coating solution can be applied to the fiber substrate (210) by immersing it in the adhesive coating solution. Alternatively, the impregnation process can be performed by passing the fiber substrate (210) through the adhesive coating solution. This impregnation can be carried out in an impregnation apparatus where the tension, impregnation time, and temperature can be controlled.

[0114] In addition, the adhesive coating solution can be applied to the fiber substrate (210) by using a doctor blade or a coating machine or by spraying with a sprayer.

[0115] The step of forming the adhesive layer (220) may further include applying an adhesive coating solution to the fiber substrate (210) and heat-treating it at 130°C to 250°C for 80 to 120 seconds. The heat treatment can be performed in conventional equipment for heat treatment. Through heat treatment, the resorcinol-formaldehyde-latex (RFL) can be cured or fixed to form the adhesive layer (220). This heat treatment allows for a more stable formation of the adhesive layer (220).

[0116] Then, the steps of coating the adhesive layer (220) with a rubber coating solution and heat-treating it are carried out to form a rubber composite layer (230) on the adhesive layer (220).

[0117] The rubber composite layer (230) may be formed from a rubber coating solution comprising an elastic polymer composition and a solvent.

[0118] The elastic polymer composition may contain an elastic polymer and additives.

[0119] The elastic polymer can be one or more rubbers selected from natural rubber and synthetic rubber. For example, the elastic polymer can be one or more rubbers selected from natural rubber (NR), styrene-butadiene rubber (SBR), cis-butadiene rubber (BR), chloroprene rubber (CR), isobutylene rubber (IBR), isoprene rubber (IR), nitrile rubber (NBR), butyl rubber, and chloroprene rubber.

[0120] Additives that can be included in elastic polymer compositions include carbon black, para oil, zinc oxide, stearic acid, anti-aging agents, sulfur, vulcanization accelerators, activators, pressure-sensitive adhesives, and adhesives.

[0121] There are no particular restrictions on the types of solvents contained in the rubber coating solution, as long as they can dissolve the elastic polymer. For example, the solvent may include at least one selected from toluene, naphtha, methanol, xylene, and tetrahydrofuran.

[0122] Based on the total weight of the rubber coating solution, the rubber coating solution may contain 10% to 40% by weight of an elastic polymer composition and 60% to 90% by weight of a solvent.

[0123] If the concentration of the elastic polymer composition in the rubber coating solution is too low, the thickness of the rubber composite layer will become too thin and will not exhibit the required pressure-sensitive adhesive strength and bond strength. Therefore, preferably, the rubber coating solution contains more than 10% by weight of the elastic polymer composition.

[0124] However, if the concentration of the elastic polymer composition in the rubber coating solution is too high, the stirring performance of the rubber coating solution will deteriorate due to increased viscosity, and the dispersion performance of the components will decrease, thus deteriorating the coating performance and causing the coating thickness to become uneven. Therefore, preferably, the rubber coating solution contains less than 40% by weight of the elastic polymer composition.

[0125] There are no particular limitations on the method of applying the rubber coating solution to the adhesive layer (220), and known coating methods can be used.

[0126] For example, in order to form a rubber composite layer (230), a fiber substrate on which an adhesive layer (220) is formed can be immersed in a rubber coating solution. By impregnation, the rubber coating solution can be applied to the adhesive layer (220).

[0127] As a coating method, gravure coating, microgravure coating, comma coating, etc., can be used. For example, by using comma coating on a comma coating machine, a rubber coating solution can be coated onto the adhesive layer (220). Here, the coating can be carried out at a temperature that allows the solvent to evaporate, for example, at a temperature of 65°C to 100°C.

[0128] After applying the rubber coating solution to the adhesive layer (220), further heat treatment is performed. The heat treatment can be carried out in conventional equipment for heat treatment. For heat treatment, heating can be performed at a temperature of 50°C to 160°C for 30 to 150 seconds.

[0129] The amount of rubber coating solution applied per unit area can be 75g / m². 2Up to 300g / m 2 or 100g / m 2 Up to 200g / m 2 By controlling the amount of rubber coating solution applied per unit area of ​​the adhesive layer (220) within the above range, a rubber-reinforced material (101) with a thin thickness but excellent adhesion and durability can be prepared.

[0130] The thickness (t1) of the rubber composite layer (230) can be 5 μm to 200 μm, or 5 μm to 150 μm, or 5 μm to 100 μm, or 5 μm to 50 μm.

[0131] Simultaneously, after forming the rubber composite layer (230), a cutting step can optionally be performed. The cutting step is the step of cutting the rubber reinforcement material (201) into a sheet shape as needed or according to the intended use. Cutting can be performed using a conventional cutting knife or a heated knife.

[0132] The rubber-reinforced material (201) prepared by the above method can be wound in a winding machine.

[0133] III. Tires

[0134] According to another embodiment of the present invention, a tire comprising the above-described rubber reinforcing material is provided.

[0135] Figure 1 This is a partial cross-sectional view of a tire (101) according to an embodiment of the present invention.

[0136] Reference Figure 1 The tire (101) includes a tread (10), a shoulder (20), a sidewall (30), a bead (40), a belt layer (50), an airtight layer (60), a carcass (70), and a crown layer (90).

[0137] The tread (10) is the part that directly contacts the road surface. The tread (10) is a robust rubber layer attached to the outside of the crown belt layer (90) and is made of rubber with excellent wear resistance. The tread (10) performs the direct function of transmitting the driving and braking forces of the vehicle to the ground. Grooves (80) are formed in the tread (10) area.

[0138] The shoulder (20) is the edge and connects to the sidewall (30). Apart from the sidewall (30), the shoulder (20) is one of the weakest parts of the tire.

[0139] The sidewall (30) is the side of the tire (101) that connects the tread (10) and the bead (40), which protects the tire carcass (70) and provides lateral stability to the tire.

[0140] The bead (40) is the area comprising the end of a steel wire wrapped around the tire carcass (70), wherein the steel wire is coated with rubber and covered with cord. The bead (40) is used to assemble and secure the tire (101) to the rim.

[0141] The belt layer (50) is a coat layer located between the tread (10) and the carcass (70). The belt layer (50) serves to prevent damage to internal structural elements such as the carcass (70) from external impacts or conditions, and to maintain the flatness of the tread (10), thereby ensuring optimal contact between the tire (101) and the road surface. The belt layer (50) may include a rubber reinforcement material (201) according to another embodiment of the invention (see...). Figure 2 ).

[0142] The airtight layer (60) is used in place of the inner tube in tubeless tires and is made of a special rubber with very low or no air permeability. The airtight layer (60) prevents air leakage from the tire (101).

[0143] The carcass (70) is formed of overlapping sheets of cords made of high-strength synthetic fibers and is an important component forming the skeleton of the tire (101). The carcass (70) is used to withstand the loads and impacts applied to the tire (101) and to maintain air pressure. The carcass (70) may include a rubber reinforcing material (201) according to another embodiment of the invention.

[0144] Grooves (80) refer to large gaps in the tread area. Grooves (80) improve drainage performance and grip when driving on wet roads.

[0145] The crown layer (90) is a protective layer beneath the tread (10) and protects other internal structural elements. The crown layer (90) must be applied to vehicles traveling at high speeds. In particular, as vehicle speed increases, the belt layer of the tire deforms, reducing ride comfort; therefore, the importance of the crown layer (90) in preventing belt layer deformation increases. The crown layer (90) may include a rubber reinforcement material (201) according to another embodiment of the invention.

[0146] A tire (101) according to one embodiment of the present invention includes a rubber reinforcement material (201). The rubber reinforcement material (201) may be applied to at least one of the crown layer (90), the belt layer (50), and the carcass (70).

[0147] Beneficial effects

[0148] His invention provides a rubber reinforcement material with a thin thickness and light weight, yet excellent durability. This reinforcement material not only reduces the weight of the tire but also achieves improved rolling resistance. Attached Figure Description

[0149] Figure 1 This is a partial cross-sectional view of a tire according to an embodiment of the present invention;

[0150] Figure 2 This is a schematic cross-sectional view of a rubber-reinforced material according to an embodiment of the present invention;

[0151] Figure 3 The images shown are of the exterior of the fiber substrates according to (a) Example 1 and (b) Comparative Example 1 after the dry heat shrinkage rate was measured.

[0152] <Figure Labels>

[0153] 10: Tread 20: Shoulder

[0154] 30: Sidewall; 40: Bead

[0155] 50: Belt layer; 60: Airtight layer

[0156] 70: Tire body; 80: Groove

[0157] 90: Crown belt layer 101: Tire

[0158] 201: Rubber reinforcement material; 210: Fiber matrix

[0159] 220: Adhesive layer; 230: Rubber compound layer Detailed Implementation

[0160] In the following description, preferred embodiments are given to better understand the present invention. However, these embodiments are presented merely as illustrative of the invention, and the invention is not limited thereto.

[0161] Example 1

[0162] As warp yarn, a single-ply nylon yarn with a fineness of 630 denier (twist of 200 TPM) was prepared. As weft yarn, a single-ply cotton yarn with a fineness of 260 denier (twist of 200 TPM) was prepared. According to the standard test method of ASTM D 885 (177°C, 2 minutes, load of 0.05 g / de), the dry heat shrinkage of the weft yarn was -0.16% (see the experimental example below).

[0163] A fiber base (210) with a thickness of 45 μm and a warp density of 55 / inch (90% between warps) and a weft density of 2.5 / mm is woven using warp and weft yarns.

[0164] The fiber substrate (210) is immersed in an adhesive coating solution containing 15% by weight resorcinol-formaldehyde-latex (RFL) and 85% by weight solvent (water, H2O), and then heat-treated at 150°C for 100 seconds to form an adhesive layer (220).

[0165] Then, using a comma coater, apply 120 g / m² of the adhesive layer (220) to each unit area. 2 Up to 130g / m 2 A rubber coating was applied to the rubber, and then the solvent was evaporated at 70°C to prepare a rubber-reinforced material (201) comprising a rubber composite layer (230) with a thickness (t1) of 10 μm.

[0166] Here, as a rubber coating solution for forming the rubber composite layer (230), a solution in which the elastic polymer composition is dispersed at a concentration of 12% by weight in a mixed solvent in which toluene and tetrahydrofuran are mixed in a weight ratio of 20:80 is used.

[0167] As an elastic polymer composition, a mixture of 100 parts by weight of styrene-butadiene rubber (SBR), 60 parts by weight of carbon black, 20 parts by weight of Para oil, 3 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 2 parts by weight of anti-aging agent (RUBBERANTIOXIDANTS, BHT), 2 parts by weight of sulfur and 1 part by weight of vulcanization accelerator (ZnBX) is used.

[0168] The rubber reinforcement material (201) was cut into 10 mm widths to prepare the rubber reinforcement material for the coronal layer (90). A cutting tool was used for cutting.

[0169] The cut rubber reinforcement material is used to manufacture tires of the 205 / 55R16 standard. For tire manufacturing, a ply consisting of 1300De / 2 strand HMLS tire cords and a steel cord belt layer is used.

[0170] Specifically, rubber layers for the ply are laminated onto the airtight rubber layer, followed by lamination of the bead wires and belt layers. Then, the aforementioned rubber reinforcement material is introduced, and rubber layers for forming the tread, shoulder, and sidewall portions are sequentially formed to manufacture the green tire. The green tire is placed in a vulcanizing mold and vulcanized at 170°C for 15 minutes to produce the tire.

[0171] Example 2

[0172] Except for using a single strand of rayon yarn with a fineness of 260 denier (twist of 200 TPM) as the weft yarn, the rubber reinforcement material and the tire comprising the rubber reinforcement material were prepared by the same method as in Example 1. According to the standard test method of ASTM D 885 (177°C, 2 minutes, load of 0.05 g / de), the dry heat shrinkage of the weft yarn was +0.27% (see the experimental example below).

[0173] Comparative Example 1

[0174] Except that a single strand of nylon yarn with a fineness of 630 denier (twist of 200 TPM) was used as the weft yarn, the rubber reinforcement material and the tire comprising the rubber reinforcement material were prepared by the same method as in Example 1. According to the standard test method of ASTM D 885 (177°C, 2 minutes, load of 0.05 g / de), the dry heat shrinkage of the weft yarn was +5.06% (see Experimental Example below).

[0175] Comparative Example 2

[0176] Except for using cotton-covered nylon yarn (twist of 200 TPM) with a fineness of 160 denier as the weft yarn, the rubber reinforcement material and the tire comprising the rubber reinforcement material were prepared by the same method as in Example 1. According to the standard test method of ASTM D 885 (177°C, 2 minutes, load of 0.05 g / de), the dry heat shrinkage of the weft yarn was +1.04% (see the experimental example below).

[0177] Experimental Example

[0178] (1) Thickness measurement

[0179] The thickness of the fiber substrate and rubber compound layer in each rubber reinforcement material according to the examples and comparative examples was measured using a vernier caliper from Mitutoyo Corporation.

[0180] (2) Measurement of the dry heat shrinkage rate of weft yarn

[0181] According to the standard test method of ASTM D 885, a load of 0.05 g / de was applied to each weft sample (60 cm in length) used in the examples and comparative examples, and the samples were heated at 177°C for 2 minutes. The change in length of the weft sample was then measured. A total of 5 measurements were taken, and the average rate of change (%) of the weft sample length is shown in Table 1 below. A dry heat shrinkage value of (+) indicates shrinkage behavior, and a value of (-) indicates relaxation behavior.

[0182] (3) Measurement of the dry heat shrinkage rate of the fiber substrate

[0183] According to the standard test method of ASTM D 885, based on the fineness of the weft yarn, a load of 0.05 g / de was applied in the weft direction to each fiber substrate specimen (60 cm in length × 1 cm in width) according to the examples and comparative examples, and heated at 177°C for 2 minutes. The changes in length and width of the fiber substrate specimens were then measured. A total of 5 measurements were performed, and the average rate of change (%) of the area of ​​the fiber substrate specimens is shown in Table 1 below. A dry heat shrinkage value of (+) indicates shrinkage behavior, and a value of (-) indicates relaxation behavior.

[0184] [Table 1]

[0185] Dry heat shrinkage rate (%) Example 1 Example 2 Comparative Example 1 Comparative Example 2 weft yarn -0.16 +0.27 +5.06 -1.04 Fiber substrate -0.25 +0.21 +5.02 -1.08

[0186] (4) Measurement of dry heat shrinkage rate of rubber reinforced materials

[0187] According to the standard test method of ASTM D 885, each rubber reinforcement specimen (60 cm in length × 1 cm in width) according to the examples and comparative examples was subjected to a load (5 g or 10 g) in the weft direction and heated (25°C, 150°C, 160°C, or 177°C) for 2 minutes, and then the changes in length and width of the rubber reinforcement specimen were measured. A total of 5 measurements were performed, and the average rate of change (%) of the area of ​​the rubber reinforcement specimen is shown in Table 2 below. A dry heat shrinkage value of (+) indicates shrinkage behavior, and a value of (-) indicates relaxation behavior.

[0188] [Table 2]

[0189]

[0190] (5) Appearance of fiber substrate

[0191] After measuring the dry heat shrinkage rate of the fiber substrate according to Experimental Example 3, the appearance of each fiber substrate according to Example 1 and Comparative Example 1 was photographed using a camera. The photographed images are shown below. Figure 3 (a) Example 1, (b) Comparative Example 1).

[0192] refer to Figure 3 It can be confirmed that in the fiber substrate of Comparative Example 1, wrinkles are generated due to the overlapping of misaligned warp yarns. Conversely, it can be confirmed that in the fiber substrate of Example 1, the warp yarns are evenly arranged and no wrinkles are generated.

[0193] (6) Measurement of tensile properties of rubber-reinforced materials

[0194] Each rubber-reinforced material specimen (size: 25 cm in length and 1 cm in width in the weft direction) according to Example 1 and Comparative Example 1 was installed in a half-chamber to measure tensile properties.

[0195] The specimen was mounted perpendicular to the horizontal plane in the upper and lower clamps of the half-chamber (distance between clamps: 20 cm). The portion of the specimen located between the clamps (heated length 12 cm) was heated (25°C, 150°C, 160°C, or 177°C) for 2 minutes, and then stretched at a speed of 300 mm / min. The maximum load (kgf) and tensile strain at specimen fracture were measured. A total of 5 measurements were taken, and the average values ​​are shown in Table 3 below.

[0196] [Table 3]

[0197]

[0198] Referring to Table 3, the rubber reinforcement material of Comparative Example 1 exhibits higher tensile strain compared to the rubber reinforcement material of Example 1. This indicates that due to the overlap of the fabric during the preparation process, it is difficult to prepare a uniform product using the rubber reinforcement material of Comparative Example 1. Therefore, it can be expected that the rubber reinforcement material of Comparative Example 1 has relatively poor preparation uniformity.

[0199] (7) Evaluation of tire performance

[0200] As a reference example, a standard 205 / 60R16 tire is manufactured using tire cords prepared by a rolling process (using two strands of nylon with a fineness of 840 denier as warp yarns, with a warp density of 25 / inch).

[0201] For each tire of the Reference Example and Example 1, the following performance was measured. The performance values ​​of the tire of Example 1 are converted from the performance values ​​(100%) of the tire of the Reference Example.

[0202] - Material weight: The weight of the rubber reinforcement material in Example 1 and the tire cord in the reference example.

[0203] - Tire weight: Tire weights in Example 1 and the reference example

[0204] - High-speed driving performance: Measured according to the US FMVSS 139H standard test method.

[0205] -Durability I: Measured according to the US FMVSS 139E standard test method.

[0206] -Durability II: Measured according to the European ECE-R119 standard test method

[0207] - Rolling resistance (RRc): Measured according to the standard test method of ISO 28580.

[0208] [Table 4]

[0209] tire Example 1 (Index) Reference example (index) Material weight 30 100 Tire weight 98 100 High-speed driving performance 104 100 Durability I 106 100 Durability II 105 100 Rolling resistance (RRc) 102 100

[0210] Referring to Table 4, it can be confirmed that since the tire of Example 1 includes a rubber reinforcing material according to an embodiment of the present invention, it has a reduced weight but exhibits excellent high-speed driving performance, durability and rolling resistance.

Claims

1. A rubber-reinforced material, comprising: Fiber substrate; An adhesive layer located on the fiber substrate; and The rubber compound layer located on the adhesive layer, The fiber substrate is a fabric woven from warp and weft yarns. The warp yarns are single-ply yarns with a fineness of 420 denier to 800 denier, and are included in the fabric with a warp density of 55 / inch to 65 / inch. According to the standard test method of ASTM D 885, with a load of 0.05 g / de applied and heated at 177°C for 2 minutes, the dry heat shrinkage rate of the weft yarn is -0.50% to +0.50%. The weft yarn is a single-ply yarn with a fineness of 420 denier to 800 denier, and is included in the fabric with a weft density of 0.05 / mm to 5 / mm. In a tensile test at 150°C with a sample size of 25 cm in the weft direction and 1 cm in width, the maximum load of the rubber reinforcement was 1.0 kgf to 1.2 kgf and the tensile strain was 11% to 13%.

2. The rubber reinforcing material according to claim 1, wherein, The warp and weft yarns each comprise one or more materials selected from nylon, rayon, polyester, and cotton.

3. The rubber reinforcing material according to claim 1, wherein, The warp yarn and the weft yarn each comprise an aromatic polyamide.

4. The rubber reinforcing material according to claim 1, wherein, The thickness of the fiber substrate is 100 μm to 600 μm.

5. The rubber reinforcing material according to claim 1, wherein, According to the standard test method of ASTM D 885, a load of 0.05 g / de based on the weft fineness was applied to the fiber substrate specimen, the specimen size was 60 cm in length and 1 cm in width in the weft direction, and it was heated at 177°C for 2 minutes. The dry heat shrinkage rate of the fiber substrate was -0.50% to +0.50%.

6. The rubber reinforcing material according to claim 1, wherein, The adhesive layer comprises resorcinol-formaldehyde-latex (RFL).

7. The rubber reinforcing material according to claim 1, wherein, The rubber composite layer comprises one or more elastic polymers selected from natural rubber and synthetic rubber.

8. The rubber reinforcing material according to claim 1, wherein, The thickness of the rubber composite layer is from 5 μm to 200 μm.

9. A method for preparing a rubber-reinforced material according to claim 1, comprising the following steps: Prepare a fiber substrate using warp yarns of 420 to 800 denier fineness and weft yarns of -0.50% to +0.50% dry heat shrinkage, woven at a warp density of 55 to 65 / inch; according to the standard test method of ASTM D 885, a load of 0.05 g / de is applied and the substrate is heated at 177°C for 2 minutes. An adhesive layer is formed on the fiber substrate; and A rubber coating solution is applied to the adhesive layer and then heat-treated to form a rubber composite layer on the adhesive layer. The weft yarn is a single-ply yarn with a fineness of 420 denier to 800 denier, and is included in the fabric with a weft density of 0.05 / mm to 5 / mm. In a tensile test at 150°C with a sample size of 25 cm in the weft direction and 1 cm in width, the maximum load of the rubber reinforcement was 1.0 kgf to 1.2 kgf and the tensile strain was 11% to 13%.

10. The preparation method according to claim 9, wherein, The adhesive layer comprises resorcinol-formaldehyde-latex (RFL).

11. The preparation method according to claim 9, wherein, The rubber coating solution comprises: 10% to 40% by weight of an elastic polymer composition selected from one or more natural rubbers and synthetic rubbers; and 60% to 90% by weight of a solvent.

12. A tire comprising the rubber reinforcing material according to claim 1.

13. The tire according to claim 12, wherein, The rubber reinforcement material is applied to at least one of the crown layer, belt layer, and carcass.

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