阅读说明：本技术 重量减轻的橡胶增强材料、其制备方法和包括其的轮胎 (Rubber reinforcement with reduced weight, method for the production thereof and tire comprising the same ) 是由 金多爱 全玉花 李敏镐 崔松莲 任钟河 于 2018-06-25 设计创作，主要内容包括：本发明的一个实施例提供一种橡胶增强材料,包括：纤维基底；设置在纤维基底上的粘合层；设置在粘合层上的橡胶化合物层；以及间苯二酚-甲醛-胶乳(RFL),其中,橡胶化合物层具有5μm至200μm的厚度。(One embodiment of the present invention provides a rubber reinforcing material comprising: a fibrous substrate; an adhesive layer disposed on the fibrous substrate; a rubber compound layer disposed on the adhesive layer; and resorcinol-formaldehyde-latex (RFL), wherein the rubber compound layer has a thickness of 5 μm to 200 μm.)

1. A rubber reinforcement comprising:

a fibrous substrate;

an adhesive layer disposed on the fibrous substrate; and

a rubber compound layer disposed on the adhesive layer,

wherein the rubber compound layer has a thickness of 5 μm to 200 μm.

2. The rubber reinforcement material according to claim 1,

the rubber compound layer has a thickness of 5 μm to 30 μm.

3. The rubber reinforcement material according to claim 1,

the rubber compound layer is formed from a rubber compound solution, and

the rubber compound solution includes 10 to 40 wt% of the elastomer composition and 60 to 90 wt% of the solvent, based on the total weight of the rubber compound solution.

4. The rubber reinforcement material according to claim 1,

the elastomer composition comprises at least one elastomeric polymer selected from the group consisting of natural rubber, styrene-butadiene rubber, chloroprene rubber, isobutylene rubber, isoprene rubber, nitrile rubber, butyl rubber, and chloroprene rubber.

5. The rubber reinforcement material according to claim 1,

the solvent includes at least one selected from the group consisting of toluene, naphtha, methanol, xylene, and tetrahydrofuran.

6. The rubber reinforcement material according to claim 1,

the adhesive layer comprises resorcinol-formaldehyde-latex RFL.

7. The rubber reinforcement material according to claim 1,

the fibrous substrate comprises at least one of a fibrous yarn and a textile substrate.

8. The rubber reinforcement material according to claim 1,

the textile substrate is a fabric formed by weaving fiber yarns.

9. The rubber reinforcement material according to claim 1,

the rubber reinforcement has an adhesion of 3N/inch or more.

10. A method of preparing a rubber reinforcement material comprising:

a step of preparing a textile substrate;

a step of forming an adhesive layer on the textile substrate; and

a step of coating a rubber compound solution on the adhesive layer and performing heat treatment to form a rubber compound layer on the adhesive layer,

wherein the rubber compound solution comprises 10 to 40 weight percent of the elastomer composition and 60 to 90 weight percent of the solvent, based on the total weight of the rubber compound solution.

11. The method for producing a rubber-reinforced material according to claim 10,

the rubber compound layer has a thickness of 5 μm to 200 μm.

12. The method for producing a rubber-reinforced material according to claim 10,

the rubber compound layer has a thickness of 5 μm to 30 μm.

13. The method for producing a rubber-reinforced material according to claim 10,

the elastomer composition comprises at least one elastomeric polymer selected from the group consisting of natural rubber, styrene-butadiene rubber, chloroprene rubber, isobutylene rubber, isoprene rubber, nitrile rubber, butyl rubber, and chloroprene rubber.

14. The method for producing a rubber-reinforced material according to claim 10,

the solvent includes at least one selected from the group consisting of toluene, naphtha, methanol, xylene, and tetrahydrofuran.

15. The method for producing a rubber-reinforced material according to claim 10,

the step of preparing the textile substrate includes the step of weaving the fiber yarns to prepare the textile substrate.

16. The method for producing a rubber-reinforced material according to claim 10,

the method further includes a step of cutting after the rubber compound layer is formed.

17. A tire comprising the rubber reinforcement material according to any one of claims 1 to 9.

18. The tire according to claim 17,

the rubber reinforcing material is applied to at least one of a cap ply, a belt and a carcass.

Technical Field

The present invention relates to a rubber-reinforced material capable of reducing the weight of a tire, a method for producing the rubber-reinforced material, and a tire comprising the rubber-reinforced material.

Background

As a rubber reinforcing material applied to a rubber structure such as a tire, a belt, a hose, a fiber type reinforcing material including synthetic fibers such as polyester fibers typified by polyethylene terephthalate (PET), polyamide fibers typified by nylon, and aromatic polyamide fibers, polyvinyl alcohol fibers, and the like is used.

Recently, as automobile performance and road conditions improve, the driving speed is getting faster. Therefore, it is required to maintain the stability and durability of the tire even during high-speed running. For this reason, much research has been conducted on tire cords used as reinforcements of tire rubber. In addition, recently, there is a demand for a tire that is light in weight and excellent in durability, in consideration of energy problems, fuel efficiency, and environmental problems.

The tire cords are classified according to the portion and the action of use into a carcass portion that supports the entire tire, a belt layer portion that supports a load and prevents any deformation that may be caused when high-speed running is performed, and a crown layer portion that prevents any deformation of the belt layer portion (see fig. 1). In particular, as the running speed becomes faster and faster due to improvement of the highway condition, the belt layer portion of the tire cord is deformed, resulting in degradation of the ride quality. Therefore, a cap ply portion for preventing deformation of the belt layer portion becomes more and more important.

For example, materials for the belt, carcass, and cap ply include nylon, rayon, aramid, and polyester containing PET.

Among them, nylon is used for tires of various sizes because it is less expensive and has excellent adhesion property and higher adhesion before and after fatigue compared to other materials. One of the main functions of the cap ply is to support the belt during high speed driving. Nylon has a high shrinkage stress and thus exhibits excellent performance for supporting the belt layer during high-speed running. However, nylon as a cap ply material has the disadvantage that flat spots may be caused due to the low modulus of nylon and the large variability between room temperature and high temperature.

Compared to nylon, aramid has lower shrinkage stress, superior creep performance, and very high modulus. In addition, the aramid exhibits little change in modulus of the aramid at room temperature and high temperature, and thus, when the aramid is used, it hardly causes a flat spot phenomenon in the tire even after a long-term parking. Although such aramid has been used for high-grade tires, for which tire quality is very important, it is difficult to apply to general-purpose tires due to high cost. Further, since the aramid has a high modulus, which makes it difficult to expand the tire in the tire building and curing process, it is difficult to apply the aramid to a general tire. Another disadvantage of aramids is also that their elongation at break is too low to ensure long-term durability.

To remedy the above drawbacks, a ply twisted yarn (pliidtwittedaran) of mixed structure has been developed, which comprises both nylon and aramid. When such ply-twisted yarns are used, problems associated with swelling and fatigue durability problems in tire manufacturing processes can be solved.

Tire cords composed of fibers such as nylon, rayon, aramid, PET, polyester, or hybrid plied twisted yarns are typically rolled with a rubber component to adhere to the rubber. That is, a rolling process is involved in the tire manufacturing process. Incidentally, when a rolling process for adhesion of a tire cord and rubber is applied in a tire manufacturing process, processing cost increases, and the density of a tire exceeds necessity due to rolling, thereby unnecessarily increasing the weight of the tire.

In the process of rolling rubber on a tire cord, solid rubber is generally used. It is difficult to form a product formed by such rubber rolling into a thin film of 200 μm or less. When these products are used as reinforcements, the thickness and weight of the tire increase.

On the other hand, recently, in order to reduce the weight of the tire and the weight of the reinforcing material, the tire manufacturer tries to reduce the thickness of the rubber layer. Rolling Resistance (R/R) is related to the weight of the tire and has a significant impact on the fuel consumption and carbon dioxide emissions of the vehicle. For example, the greater the rolling resistance (R/R), the higher the energy required to drive the vehicle. In addition, the resistance to rotation, tilting and acceleration of the vehicle is closely related to the weight of the vehicle. Therefore, reduction of the weight of the vehicle by reducing the weight of the tire, thereby reducing energy consumption, is also being studied.

Therefore, it is required to develop a tire cord having a thin thickness while exhibiting excellent adhesion with respect to rubber.

Disclosure of Invention

Technical problem

The present invention has been designed to solve the limitations and problems of the related art as described above.

An aspect of the present invention is directed to provide a rubber reinforcing material having excellent tackiness and excellent adhesiveness with respect to rubber.

Another aspect of the present invention is directed to provide a rubber reinforcing material that is thin in thickness but can exhibit excellent performance as a tire reinforcing material.

Another aspect of the present invention is directed to providing a rubber reinforcing material capable of contributing to the thickness of a rubber layer and weight reduction of a tire.

Another aspect of the present invention is directed to providing a rubber reinforcing material having a thin rubber compound layer, which is difficult to achieve through a rolling process using solid rubber.

Still another aspect of the present invention is directed to a method of preparing such a rubber reinforcement and a tire comprising such a rubber reinforcement.

Yet another aspect of the present invention is directed to a tire having reduced weight.

The various aspects of the invention described above, as well as other features and advantages of the invention, will be apparent from the description, or may be learned by those skilled in the art from the description.

Technical scheme

In order to achieve the above object, an embodiment of the present invention provides a rubber reinforcing material including: a fibrous substrate; an adhesive layer disposed on the fibrous substrate; and a rubber compound layer disposed on the adhesive layer, wherein the rubber compound layer has a thickness of 5 to 200 μm.

The rubber compound layer may have a thickness of 5 μm to 30 μm.

The rubber compound layer is formed from a rubber compound solution, and the rubber compound solution includes 10 to 40 wt% of the elastomer composition and 60 to 90 wt% of the solvent, based on the total weight of the rubber compound solution.

The elastomer composition comprises at least one elastomeric polymer selected from the group consisting of natural rubber, styrene-butadiene rubber, chloroprene rubber, isobutylene rubber, isoprene rubber, nitrile rubber, butyl rubber, and chloroprene rubber.

The solvent comprises at least one selected from the group consisting of toluene, naphtha, methanol, xylene and tetrahydrofuran.

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

The fibrous substrate includes at least one of a fiber yarn and a textile substrate.

The textile substrate is a fabric formed by weaving fiber yarns.

The rubber reinforcement has an adhesion of 3N/inch or more.

Another embodiment of the present invention provides a method for preparing a rubber reinforcing material, the method comprising: a step of preparing a textile substrate; a step of forming an adhesive layer on a textile substrate; and a step of coating a rubber compound solution on the adhesive layer and performing a heat treatment to form a rubber compound layer on the adhesive layer, wherein the rubber compound solution includes 10 to 40 wt% of the elastomer composition and 60 to 90 wt% of the solvent, based on the total weight of the rubber compound solution.

The rubber compound layer has a thickness of 5 μm to 200 μm. More specifically, the rubber compound layer may have a thickness of 5 μm to 30 μm.

The step of preparing the textile substrate comprises the step of weaving the fiber yarns to prepare the textile substrate.

The method of preparing the rubber reinforcing material further includes a step of slitting (slitting) after the rubber compound layer is formed.

Another embodiment of the present invention provides a tire comprising the rubber reinforcing material described above.

Rubber reinforcement is applied to at least one of the cap ply, belt and carcass of the tire.

The summary of the invention described above is intended only to illustrate or explain the invention and is not intended to limit the scope of the invention.

Advantageous effects

Since the rubber reinforcing material according to one embodiment of the present invention has excellent adhesion with respect to rubber, it can be firmly adhered to rubber without passing through a rolling process in a tire manufacturing process. According to the present invention, since the rubber reinforcing material is bonded to the rubber without going through the rolling process, the manufacturing cost of the tire is reduced, which prevents the density of the tire from being exceeded and the weight of the tire from being unnecessarily increased due to rolling.

When the rubber reinforcing material according to one embodiment of the present invention is used as a tire cap ply, a belt, a carcass, or the like, a rolling process can be omitted, and thus the manufacturing process of the tire can be simplified, and the thickness and the total weight of the tire can be reduced. Further, the viscosity of the rubber reinforcing material is greatly improved. Therefore, when a green tire is manufactured, air pockets are reduced, and thus the defect rate of the tire is reduced.

In addition, according to one embodiment of the present invention, it is possible to satisfy the demand of tire manufacturers aiming at reducing the thickness of the rubber layer to provide an ultra-light tire and a light-weight reinforcing material. According to the present invention, the weight of the tire is reduced by the rubber reinforcing material having a thin thickness and excellent rubber reinforcing performance, thereby reducing rolling resistance (R/R), improving fuel efficiency of the vehicle, and reducing carbon dioxide emissions.

In particular, in the case of an electric vehicle using a battery, it is required to reduce the weight of a vehicle body so as to improve mileage and fuel consumption. When the lightweight tire reinforcement according to one embodiment of the present invention is applied, the weight of the tire is reduced, and the fuel economy and the economic efficiency of the electric vehicle can be improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the figure:

FIG. 1 is a partial cross-sectional view of a tire according to one embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view of a rubber reinforcement according to another embodiment of the present invention.

Fig. 3 is a schematic illustration of a ply-twisted yarn.

Fig. 4 is a schematic cross-sectional view of a rubber reinforcement according to another embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention. Accordingly, the present invention includes all alternatives and modifications falling within the scope of the invention as described by the claims and equivalents thereof.

Shapes, sizes, ratios, angles, numbers, and the like, which are shown in the drawings to describe exemplary embodiments of the present invention, are only examples, and the present invention is not limited thereto. Like reference numerals generally refer to like elements throughout the specification.

Terms such as "comprising," having, "and" consisting of … …, "as used herein, are generally intended to allow for the addition of other components, unless the term is used with the term" only. Any reference to the singular may include the plural unless explicitly stated otherwise. Components are to be construed as including ordinary error ranges even if not explicitly stated.

When terms such as "upper", "above", "lower" and "near" are used to describe a positional relationship between two members, more than one member may be disposed between the two members unless the terms are used together with the terms "directly" or "directly".

When terms such as "after.," "continuous to," "next," "before.," are used to describe a chronological relationship, non-continuous situations may be included unless the terms are used with the terms "immediately" or "immediately".

The term "at least one" should be understood to include all combinations that may be given from one or more related items.

The features of the various embodiments of the present disclosure may be combined or combined with each other, in part or in whole, and may be interconnected and act in various techniques, and the various embodiments may be implemented independently of each other or in association with each other.

One embodiment of the present invention provides a tire 101, the tire 101 including rubber reinforcements 201 and 301 (see fig. 1 and 2).

FIG. 1 is a partial cross-sectional view of a tire 101 according to one embodiment of the present invention.

Referring to fig. 1, a tire 101 includes a tread 10, shoulders 20, sidewalls 30, beads 40, a belt 50, an innerliner 60, a carcass 70, and a cap ply 90.

The tread 10 is a portion that is in direct contact with the road surface. The tread 10 is a strong rubber layer attached to the outer side of the cap ply 90, and is made of rubber having excellent wear resistance. The tread 10 plays a direct role in transmitting the driving force and braking force of the vehicle to the ground. A groove 80 is formed in the area of the tread 10.

The shoulder 20 is a corner of the tread 10 and is a portion connected to the sidewall 30. The shoulder 20 together with the sidewalls 30 is one of the weakest parts of the tire.

Sidewalls 30 are the sides of tire 101 that connect tread 10 and beads 40, protect carcass 70, and provide lateral stability to the tire.

The bead 40 is a region including an iron wire wound around the end of the carcass 70, and has a structure in which the iron wire is covered with a rubber film to wrap a cord. The beads 40 are used to mount and fix the tire 101 to a rim.

The belt 50 is a coating layer located between the tread 10 and the carcass 70. The belt layer 50 serves to prevent damage to internal components such as the carcass 70 due to external impact or external conditions, and to keep the shape of the tread 10 flat so that the contact between the tire 101 and the road surface is maintained in an optimum state. According to another embodiment of the present invention, the belt 50 may include rubber reinforcements 201 and 301 (see fig. 2 and 4).

The inner liner 60 is used to replace an inner tube in a tubeless tire, and is made of special rubber having little or no air permeability. The inner liner 60 prevents air filled in the tire 101 from leaking.

The carcass 70 is made by overlapping a plurality of pieces of cord paper made of strong synthetic fibers, and is an important part forming the framework of the tire 101. The carcass 70 serves to receive a load or impact to which the tire 101 is subjected and maintain air pressure. According to another embodiment of the present invention, the carcass 70 may include rubber reinforcements 201 and 301.

The grooves 80 refer to thick voids in the tread area. The grooves 80 serve to increase the drainage of the tire when driving on a wet road.

The cap ply layer 90 is a protective layer under the tread 10 and protects other components therein. The cap ply layer 90 is basically applied to a vehicle running at a high speed. In particular, as the running speed of the vehicle increases, a problem occurs such as a decrease in ride comfort due to deformation of a belt layer portion of the tire. Therefore, the importance of the cap ply layer 90 for preventing the deformation of the belt layer portion increases. According to another embodiment of the present invention, the cap ply layer 90 may be made of rubber reinforcing materials 201 and 301.

Tire 101 according to one embodiment of the present invention includes rubber reinforcement materials 201 and 301. The rubber reinforcing materials 201 and 301 may be applied to the cap ply layer 90, and may also be applied to at least one of the belt 50 and the carcass 70.

Other embodiments of the present invention provide rubber reinforcement 201 and 301. Rubber reinforcing materials 201 and 301 according to other embodiments of the present invention include: fibrous substrates 210 and 110; an adhesive layer 220 disposed on the fibrous substrates 210 and 110; and a rubber compound layer 230 disposed on the adhesive layer 220.

The fibrous substrate may be any of a fiber yarn and a textile substrate 210. The fiber yarns include ply twisted yarns 110.

Fig. 2 is a schematic cross-sectional view of a rubber reinforcement 210 according to another embodiment of the present invention.

Fig. 2 shows the use of a textile substrate 210 as the fibrous substrate of the rubber reinforcement 201. However, another embodiment of the present invention is not limited thereto, and a fiber yarn may be used as the fiber base.

As the textile substrate 210, a fabric formed by weaving fiber yarns may be used. As the fiber yarn, for example, a twisted ply yarn 110 formed by double twisting two or more of the primary twisted yarns 111 and 112 (see fig. 3) may be used. The fiber yarn may include at least one of nylon, rayon, aramid, and polyester containing PET.

According to another embodiment of the present invention, a fabric made of nylon, rayon, aramid, and polyester containing PET may be used as the textile substrate 210. For example, the textile substrate 210 may be manufactured by weaving the ply-twisted yarn 110, the ply-twisted yarn 110 being formed such that primary twisted yarns 111 and 112 selected from nylon, rayon, aramid, and polyester containing PET are secondarily twisted.

According to another embodiment of the present invention, the ply-twisted yarn 110 includes a hybrid ply-twisted yarn formed such that two or more primary twisted yarns different from each other are secondarily twisted. For example, such hybrid ply-twisted yarns may include nylon and aramid first-twisted yarns.

Fig. 3 is a schematic illustration of ply-twisted yarn 110.

Referring to fig. 3, ply-twisted yarn 110 includes first and second as-twisted yarns 111 and 112. The first and second first twisted yarns 111 and 112 are twisted together twice. First twisted yarn 111 has a first twisting direction, second first twisted yarn 112 has a second twisting direction, and first and second first twisted yarns 111 and 112 are twisted together twice in a third twisting direction. Here, the second twisting direction may be the same direction as the first twisting direction, and the third twisting direction may be opposite to the first twisting direction. However, the twisting direction is not limited thereto.

The first twist and the second twist (twist number) may be the same as or different from each other. For example, first and second as-twisted yarns 111 and 112 may have a twist of 150TPM to 500 TPM.

The first as-twisted yarn 111 and the second as-twisted yarn 112 may be the same as or different from each other. For example, first and second as-twisted yarns 111 and 112 may be individually selected from nylon, rayon, aramid, and polyester containing PET. For example, ply-twisted yarn 110 may include a hybrid ply-twisted yarn in which first twisted yarn 111 is nylon and second first twisted yarn 112 is aramid.

According to another embodiment of the present invention, the adhesive layer 220 may include resorcinol-formaldehyde-latex. For example, the adhesive layer 220 may be formed of an adhesive coating solution containing resorcinol-formaldehyde-latex (RFL) and a solvent. However, the adhesive layer 220 according to an embodiment of the present invention is not limited thereto. The adhesive layer 220 may further include an epoxy compound layer and a resorcinol-formaldehyde-latex (RFL) layer disposed on the epoxy compound layer.

Resorcinol-formaldehyde-latex (also known as "RFL") is used as an adhesive. Specifically, the resorcinol-formaldehyde-latex improves the affinity and adhesive strength between the textile substrate 210 (the textile substrate 210 is a fibrous substrate) and the rubber composition, improves the adhesive strength between the textile substrate 210 and the rubber compound layer 230, and improves the adhesive strength between the rubber-reinforced substrate 201 and the rubber. Therefore, the textile substrate 210 and the rubber compound layer 230 are stably bonded without being separated from each other, and generation of defects in the manufacturing process of the tire 101 is prevented. In addition, after the vulcanization process, the rubber reinforcement 201 and rubber (e.g., tread, etc.) may be bonded together in the finished tire to maintain excellent adhesion.

The rubber compound layer 230 may be formed of a rubber compound solution including an elastomer composition and a solvent. The rubber compound solution may include 10 to 40 wt% of the elastomer composition and 60 to 90 wt% of the solvent. The elastomer composition contained in the rubber compound solution constitutes the rubber compound layer 230.

More specifically, the rubber compound solution may include 10 to 30 wt% of the elastomer composition and 70 to 90 wt% of the solvent, in consideration of volatilization of the solvent contained in the rubber compound solution. In this case, when the solvent is volatilized after the preparation of the rubber compound solution, the content of the elastomeric polymer contained in the rubber compound solution may be 10% by weight to 40% by weight.

The elastomeric composition may include 30 to 70 weight percent of the elastomeric polymer and 30 to 70 weight percent of the additive.

For example, the elastomeric composition may include at least one elastomeric polymer selected from the group consisting of Natural Rubber (NR), styrene-butadiene rubber (SBR), Butadiene Rubber (BR), Chloroprene Rubber (CR), isobutylene rubber (IBR), Isoprene Rubber (IR), nitrile-butadiene rubber (NBR), butyl rubber, and chloroprene rubber.

The additives may include additives for forming rubber compounds, for example, carbon black, paraoil (paraoil), zinc oxide, stearic acid, age resister, sulfur, vulcanization accelerator, activator, adhesive, binder, and the like.

In the elastomer composition, when the content of the elastomer polymer is less than 30% by weight, the elasticity and adhesive strength of the rubber compound layer 230 are reduced. When the content of the elastomeric polymer exceeds 70% by weight and the content of the additive is less than 30% by weight, processability is reduced when the rubber compound layer 230 is formed using the rubber compound solution. Therefore, in the elastomer composition, the content of the elastomer polymer is adjusted in the range of 30 to 70% by weight, and the content of the additive is adjusted in the range of 30 to 70% by weight.

The type of solvent is not particularly limited as long as it can dissolve the elastomeric polymer. In particular, according to one embodiment of the present invention, a substance capable of dissolving the composition of rubber may be used as the solvent. For example, the solvent may include at least one selected from the group consisting of toluene, naphtha, methanol, xylene, and tetrahydrofuran. Toluene, naphtha, methanol, xylene and tetrahydrofuran may be used alone or in combination.

When the concentration of the elastomer composition in the rubber compound solution is less than 10% by weight, the thickness of the rubber compound layer 230 becomes thin, and tack and adhesive strength may not be properly expressed. This causes problems such as a decrease in tire manufacturing characteristics and tire defects during running.

On the other hand, when the concentration of the elastomer composition in the rubber compound solution exceeds 40% by weight, the stirring performance is lowered due to the increase in viscosity, and the dispersibility of the rubber compound solution is lowered, whereby the coating performance is lowered and the coating thickness may not be uniform.

The rubber compound layer 230 may include at least one selected from the group consisting of Natural Rubber (NR), styrene-butadiene rubber (SBR), Butadiene Rubber (BR), Chloroprene Rubber (CR), isobutylene rubber (IBR), Isoprene Rubber (IR), nitrile-butadiene rubber (NBR), butyl rubber, and chloroprene rubber.

The rubber compound layer 230 has a thickness t1 of 5 μm to 200 μm.

As shown in fig. 2, the thickness t1 of the rubber compound layer 230 is measured by the distance from one surface of the rubber compound layer 230, which is in contact with the adhesive layer 220, to the other surface of the rubber compound layer 230, which is disposed opposite to the adhesive layer 220.

When the thickness t1 of the rubber compound layer 230 is less than 5 μm, the rubber compound layer 230 does not have sufficient tackiness and adhesive strength, thereby deteriorating tire manufacturing characteristics, becoming difficult to exhibit durability of the tire and possibly causing tire defects.

When the thickness t1 of the rubber compound layer 230 exceeds 200 μm, the thickness of the rubber reinforcing material 201 increases, and thus the thickness of the tire may increase. Specifically, when the thickness t1 of the rubber compound layer 230 exceeds 200 μm, bubbles are generated in the rubber compound layer 230 during volatilization of the solvent, making it difficult for the rubber reinforcing material 201 to have a uniform thickness. When this rubber reinforcing material 201 is applied to a tire, air pockets are generated in the tire, which results in a decrease in the quality of the tire and an increase in the defect rate. In addition, there is a disadvantage in that, in order to form the thick rubber compound layer 230, the coating operation must be performed a plurality of times, which is technically inefficient and may result in a reduction in tire quality and a defect rate.

More specifically, the rubber compound layer 230 may have a thickness t1 of 5 μm to 30 μm.

In the conventional rubber reinforcing material, a rubber substrate is rolled on the fiber substrates 210 and 110 to form a rubber layer corresponding to the rubber compound layer 230 of the present invention. Since the rubber base has a prescribed thickness, the rubber layer of the rubber reinforcing material formed according to the conventional method generally has a thickness of 1000 μm or more and a thickness of at least 800 μm or more.

On the other hand, since the rubber compound layer 230 according to another embodiment of the present invention is formed by dipping or coating a rubber compound solution, the rubber compound layer 230 may have a thickness t1 of 200 μm or less. According to one embodiment of the present invention, since the rubber compound layer 230 has the thin thickness t1 of 5 μm to 200 μm, the total thickness of the rubber reinforcing material 201 becomes thin. Therefore, the thickness of a tire using such a rubber reinforcing material 201 can be reduced.

The rubber reinforcement 201 according to another embodiment of the present invention has excellent adhesiveness. Stickiness can be expressed as a tack strength. For example, the rubber reinforcement 201 according to another embodiment of the present invention may have a tack strength of 3N/inch or more. Here, the tack strength is a value measured by the PEEL test method (crosshead speed 125mm/min) using an Instron Clamp (Grip, CAT. No. 2712-041).

When the viscous strength of the rubber reinforcing material 201 is 3N/inch or more, the rubber reinforcing material is attached to the rubber without causing a phenomenon of dropping in the tire manufacturing process, and thus the tire manufacturing process can be stably performed. If the adhesive strength of the rubber reinforcing material 201 is less than 3N/inch, defects may occur due to dropping during the tire manufacturing process. In addition, when the viscous strength of the rubber reinforcing material 201 is less than 3N/inch, air pockets may be generated when manufacturing the green tire, thereby increasing the defect rate of the tire.

On the other hand, if the adhesive strength of the rubber reinforcing material 201 is too high, inconvenience may be caused during storage of the rubber reinforcing material 201 due to excessive tackiness, and workability may be reduced because tension is unevenly applied during rewinding due to excessive tackiness between the rubber reinforcing materials 201 in manufacture of the tire. Therefore, the adhesive strength of the rubber reinforcing material 201 can be adjusted to a range of 40N/inch or less. More specifically, the adhesive strength of the rubber reinforcing material 201 can be adjusted to a range of 17N/inch or less. According to another embodiment of the present invention, for example, the adhesive strength of the rubber reinforcement 201 may be adjusted within a range of 4N/inch to 17N/inch. Alternatively, the adhesive strength of the rubber reinforcement 201 according to another embodiment of the present invention may be adjusted within a range of 5N/inch to 17N/inch.

Rubber reinforcement 201 according to another embodiment of the present invention may be applied to the cap ply 90, belt 50 or carcass 70 of tire 101.

Fig. 4 is a schematic cross-sectional view of a rubber reinforcement 301 according to another embodiment of the present invention.

The rubber reinforcement 301 of fig. 4 illustrates the use of ply-twisted yarns 110 as the fiber base. As described above, the ply-twisted yarn 110 may be formed such that two or more primary twisted yarns 111 and 112 are secondarily twisted. However, one embodiment of the present invention is not limited thereto, and other ply-twisted yarns known in the art may be used to manufacture the rubber reinforcing material 301.

The rubber reinforcing material 301 according to another embodiment of the present invention includes: ply-twisted yarns 110, the ply-twisted yarns 110 being a fibrous substrate; an adhesive layer 220 disposed on the ply-twisted yarn 110; and a rubber compound layer 230 disposed on the adhesive layer 220.

Since the ply-twisted yarn 110, the adhesive layer 220, and the rubber compound layer 230 have been described, detailed description thereof will be omitted to avoid repetition.

Hereinafter, a method of preparing the rubber reinforcing materials 201 and 301 according to another embodiment of the present invention will be described.

A method of preparing rubber reinforcing materials 201 and 301 according to an embodiment of the present invention includes: a step of preparing textile substrates 210 and 110; a step of forming an adhesive layer 220 on the textile substrates 210 and 110; and a step of coating a rubber compound solution on the adhesive layer 220 and performing heat treatment to form a rubber compound layer 230 on the adhesive layer 220.

The fibrous substrates 210 and 110 may be a fibrous yarn or textile substrate 210. Ply twisted yarns 110 may be used as the fiber yarns 210. The textile substrate 210 is formed by weaving fiber yarns. Thus, the step of preparing the textile substrate may include the step of weaving the fiber yarns to produce the textile substrate 210.

The ply yarn 110 used as the fiber yarn may include a hybrid ply twisted yarn formed such that two or more first twisted yarns different from each other are secondarily twisted.

According to another embodiment of the present invention, the hybrid plied twisted yarns may include nylon and aramid first twisted yarns. The nylon twist may have a denier of 300de to 2000de, and more particularly, the nylon twist may have a denier of 1100de to 1400 de. The aramid primarily twisted yarn may have a denier of 500 to 3000de, and more particularly, the aramid primarily twisted yarn may have a denier of 1300 to 1700 de.

For example, a twisted yarn 110 is manufactured by simultaneously performing primary twisting and secondary twisting by a Cable twister (Cable Corder twister) with a nylon filament of 300de to 2000de as a first primary twisted yarn 111 and an aramid filament of 500de to 3000de as a second primary twisted yarn 112, wherein the primary twisting is performed in a counterclockwise direction and the secondary twisting is performed in a clockwise direction. The ply twisted yarn may have a twist of 150TPM to 500 TPM.

The adhesive layer 220 is formed on the fibrous substrates 210 and 110.

The adhesive layer 220 may be formed of an adhesive coating solution including resorcinol-formaldehyde-latex (RFL) and a solvent. The step of forming the adhesive layer 220 may include the steps of coating an adhesive coating solution on the fiber substrates 210 and 110 and performing a heat treatment.

The method of coating the adhesive coating solution on the fiber substrates 210 and 110 is not particularly limited. For example, the binder coating solution may be coated on the fibrous substrates 210 and 110 by dipping the fibrous substrates 210 and 110 into the binder coating solution. For example, the impregnation process may be performed by passing the fiber substrates 210 and 110 through a binder coating solution. The impregnation process may be performed with an impregnator capable of adjusting tension, impregnation time, and temperature.

In addition to the dipping process, the adhesive coating solution may be coated on the fiber substrates 210 and 110 by coating using a blade or a coater or spraying using a sprayer. The step of forming the adhesive layer 220 may further include the step of coating the adhesive coating solution on the fiber substrates 210 and 110 and performing a heat treatment at 130 to 170 ℃ for 80 to 120 seconds. The heat treatment may be performed by a heat treatment apparatus. The resorcinol-formaldehyde-latex (RFL) layer 222 is cured and fixed by heat treatment to complete the adhesive layer 220. By this heat treatment, the adhesive layer 220 can be formed more stably.

After the adhesive layer 220 is formed, a rubber compound solution is coated on the adhesive layer 220 and heat-treated to form a rubber compound layer 230 on the adhesive layer 220.

The rubber compound solution includes an elastomer composition and a solvent. Specifically, the rubber compound solution includes 10 to 40% by weight of the elastomer composition and 70 to 90% by weight of the solvent. The rubber compound solution may include 10 to 30 wt% of the elastomer composition and 70 to 90 wt% of the solvent based on the manufacturing in consideration of volatilization of the solvent contained in the rubber compound solution. In this case, when the solvent is volatilized after the preparation of the rubber compound solution, the content of the elastomeric polymer contained in the rubber compound solution may be 10% by weight to 40% by weight.

When the concentration of the elastomer composition in the rubber compound solution is less than 10% by weight, the thickness t1 of the rubber compound layer 230 becomes thin, and tack and adhesive strength may not be properly expressed. This causes problems such as a decrease in tire manufacturing characteristics and tire defects during running. On the other hand, when the concentration of the elastomer composition in the rubber compound solution exceeds 40% by weight, the stirring performance of the adhesive solution is lowered due to the increase in viscosity, and the dispersibility of the rubber compound solution is lowered, whereby the coating performance is lowered and the coating thickness may not be uniform.

Therefore, the concentration of the elastomer composition in the rubber compound solution is adjusted in the range of 10 to 40% by weight.

The elastomeric composition may include 30 to 70 weight percent of the elastomeric polymer and 30 to 70 weight percent of the additive.

For example, the elastomer composition may include at least one elastomer selected from the group consisting of Natural Rubber (NR), styrene-butadiene rubber (SBR), Butadiene Rubber (BR), Chloroprene Rubber (CR), isobutylene rubber (IBR), Isoprene Rubber (IR), nitrile-butadiene rubber (NBR), butyl rubber, and chloroprene rubber. The additives may include additives for forming rubber compounds, for example, carbon black, paraoil (paraoil), zinc oxide, stearic acid, age resister, sulfur, vulcanization accelerator, activator, adhesive, binder, and the like.

The solvent may include at least one selected from the group consisting of toluene, naphtha, methanol, xylene and tetrahydrofuran, which may be used alone or in combination.

The method of applying the rubber compound solution on the adhesive layer 220 is not particularly limited, and a known application method may be used.

For example, in order to form the rubber compound layer 230, the fiber substrates 210 and 110 coated with the adhesive layer 220 may be immersed in a rubber compound solution. By this dipping, the rubber compound solution is coated on the adhesive layer 220.

In addition, the rubber compound solution may be coated on the adhesive layer 220 by comma coating using a comma coater (comma coater). At this time, the coating may be performed under a temperature condition of 80 to 100 ℃. This temperature corresponds to the lowest temperature at which the solvent can evaporate.

However, another embodiment of the present invention is not limited thereto, and the rubber compound solution may be applied by a gravure coating method, a micro-gravure coating method, or the like.

After the rubber compound solution is coated, the coated rubber compound solution may be subjected to a heat treatment. That is, the step of forming the rubber compound layer 230 may include a step of coating a rubber compound solution on the adhesive layer 220 and then performing heat treatment.

The heat treatment may be performed by a heat treatment apparatus. For the heat treatment, heating may be performed at a temperature of 80 ℃ to 160 ℃ for 30 seconds to 150 seconds. As a result, the rubber compound layer 230 is formed on the adhesive layer 220.

By this process, the rubber reinforcing materials 201 and 301 are prepared, and the prepared rubber reinforcing materials 201 and 301 are wound on a winder.

In this case, the rubber compound layer 230 may have a thickness t1 of 5 μm to 200 μm. The thickness t1 of the rubber compound layer 230 is less than 5 μm, and the rubber compound layer 230 does not have sufficient tackiness and adhesive strength, so tire manufacturing characteristics deteriorate and tire defects may occur. When the thickness t1 of the rubber compound layer 230 exceeds 200 μm, the thickness of the rubber reinforcing material 201 may increase, resulting in an increase in the thickness of the tire.

More specifically, the rubber compound layer 230 may have a thickness t1 of 5 μm to 30 μm.

Next, a cutting step may optionally be performed.

The method may further include a step of cutting the rubber reinforcing material 201 manufactured in a plate shape so as to meet the purpose or need of use. This cutting is called trimming. The cutting step may be omitted. The method of cutting or clipping is not particularly limited.

The cutting is performed by cutting the rubber reinforcing material 201 with a conventional cutting knife or heating knife according to the request of the user or customer, for example, using a width of 3mm to 50mm or limiting the number of warps. According to another embodiment of the present invention, the cut rubber reinforcement 201 may have a width of 3mm to 50 mm.

Through this process, the rubber reinforcing materials 201 and 301 according to the embodiment of the present invention are completed.

For example, the rubber reinforcing materials 201 and 301 manufactured in this manner can be used as the cap ply 90 of the tire 101.

The rubber reinforcement 201 according to one embodiment of the present invention has excellent adhesion with respect to rubber, and the rubber reinforcement 201 can be easily attached to rubber without a conventional rolling process. When such a rubber reinforcing material 201 is used as the cap ply 90, the rolling process can be omitted, and therefore, the manufacturing process of the tire can be simplified. Further, the tackiness of the cap ply layer 90 is greatly improved, and air pockets are reduced when manufacturing the green tire, thereby reducing the defect rate of the tire. In addition, since the rolling process is not performed, the tire 101 can be manufactured to be thin and light.

Such rubber reinforcing materials 201 and 301 may be applied to at least one of the belt and the carcass.

Hereinafter, the operation and effect of the present invention will be described in more detail by specific production examples and comparative examples. However, these preparation examples and comparative examples are presented only for illustrative purposes, and the scope of the present invention is not limited thereto.

< preparation example 1>

(1) Production of textile substrates: nylon/aramid plied twisted yarn knit

The twisted yarn 110 was manufactured by simultaneously performing primary twisting and secondary twisting with 1260de nylon filament (first primary twisted yarn) and 1500de aramid filament (second primary twisted yarn) by a cable twister, in which the primary twisting was performed in a counterclockwise direction and the secondary twisting was performed in a clockwise direction. The twist of ply-twisted yarn 110 is 300 TPM.

The textile substrate 210 in the form of a fabric is manufactured by weaving the fabric using the ply-twisted yarns 110 manufactured in this manner as warp yarns and using cotton yarns as weft yarns. The textile substrate 210 thus manufactured is used as a fibrous substrate.

(2) Formation of adhesive layer

The textile substrate 210 is immersed in the adhesive coating solution and then subjected to a heat treatment to complete the adhesive layer 220. At this time, the adhesive coating solution contained 15 wt% of resorcinol-formaldehyde-latex (RFL) and 85 wt% of solvent (water, H) based on the total weight₂O). In addition, the adhesive coating solution coated on the textile substrate 210 is dried by heat treatment at 150 ℃ for 100 seconds, and then heat treatment at 240 ℃ for 100 seconds again.

(3) Formation of a layer of a rubber compound

First, the following elastomer compositions were produced. The elastomer composition comprises 60 parts by weight of carbon black, 20 parts by weight of paraoil (paraoil), 3 parts by weight of zinc oxide, 2 parts by weight of stearic acid, 2 parts by weight of an age resistor (rubber antioxidant, BHT), 2 parts by weight of sulfur and 1 part by weight of a vulcanization accelerator (ZnBX) based on 100 parts by weight of styrene-butadiene rubber (SBR).

Next, a mixed solvent of toluene and tetrahydrofuran was prepared in a weight ratio of 20: 80.

Next, the elastomer composition was dispersed in the mixed solvent at a concentration of 13% to produce a rubber compound solution.

The rubber compound solution is coated on the coating layer 230 formed on the textile substrate 210 using a comma coater, and the solvent is volatilized at a temperature of 80 ℃ to form the rubber compound layer 230. Here, the thickness t1 of the rubber compound layer 230 is 13 μm. Thereby, the rubber reinforcement 201 is manufactured.

(4) Manufacture of rubber reinforcement for cap ply that has been cut to standard

The thus-produced rubber reinforcing material 201 was cut into a width of 10mm to produce a rubber reinforcing material for the cap ply 90. Cutting is performed using a cutting knife.

(5) Manufacture of tires

205/55R16 size tires were made with cut rubber reinforcement. For the manufacture of the tire, a ply (body plies) comprising 1300De/2ply HMLS tire cords and steel cord belts were used.

Specifically, a ply rubber was laminated on the inner liner rubber, the bead wire and the belt were laminated, and then the rubber reinforcing material prepared as described above was added. Rubber layers for forming the tread portion, shoulder portion and sidewall portion are formed in this order, thereby manufacturing a green tire. The green tire thus manufactured was put into a vulcanization mold and vulcanized at 170 ℃ for 15 minutes to manufacture a tire.

< preparation example 2>

A tire reinforcing material 210 and a tire were manufactured in the same manner as in preparation example 1, except that in the formation of the rubber compound layer 230, a rubber compound solution was prepared by dispersing an elastomer composition in a mixed solvent at a concentration of 17%, and the thickness t1 of the rubber compound layer 230 was 20 μm.

< preparation example 3>

A tire reinforcing material 210 and a tire were manufactured in the same manner as in preparation example 1, except that in the formation of the rubber compound layer 230, a rubber compound solution was prepared by dispersing an elastomer composition in a mixed solvent at a concentration of 25%, and the thickness t1 of the rubber compound layer 230 was 36 μm.

< comparative example 1>

A tire reinforcing material 210 and a tire were manufactured in the same manner as in preparation example 1, except that rubber having a thickness of 1.6mm was disposed on the adhesive layer 220 on the textile substrate 210 and rolled to form a rubber reinforcing material, without forming the rubber compound layer 230 using a rubber compound solution.

< comparative example 2>

A tire reinforcing material 210 and a tire were manufactured in the same manner as in preparation example 1, except that the process of forming the rubber compound layer 230 was omitted.

< comparative example 3>

A tire reinforcing material 210 and a tire were manufactured in the same manner as in preparation example 1, except that in the formation of the rubber compound layer 230, a rubber compound solution was prepared by dispersing an elastomer composition in a mixed solvent at a concentration of 5%, and the thickness t1 of the rubber compound layer 230 was 4.5 μm.

< comparative example 4>

A tire reinforcing material 210 and a tire were manufactured in the same manner as in preparation example 1, except that in the formation of the rubber compound layer 230, a rubber compound solution was prepared by dispersing the elastomer composition in a mixed solvent at a concentration of 45%, and the thickness t1 of the rubber compound layer 230 was 210 μm.

< preparation example 4>

(1) Preparation of the textile substrate: nylon plain weave fabric

The raw fabric (raw fabric) was woven using nylon filaments having a total denier of 630 de. At this time, the weaving density was set to 55 th/inch of warp density and 10 th/inch of weft density to prepare the textile substrate 210 in the form of a fabric.

Subsequently, (2) formation of an adhesive layer, (3) formation of a rubber compound layer (thickness of the rubber compound layer: 10 μm), (4) manufacture of a rubber reinforcing material for cap ply, which has been cut into a standard, and (5) manufacture of a tire were performed in the same manner as in production example 1, thereby manufacturing a tire reinforcing material 210 and a tire according to production example 4.

< preparation example 5>

A tire reinforcing material 210 and a tire were manufactured in the same manner as in preparation example 4, except that in the formation of the rubber compound layer 230, a rubber compound solution was prepared by dispersing an elastomer composition in a mixed solvent at a concentration of 17%, and the thickness t1 of the rubber compound layer 230 was 18 μm.

< preparation example 6>

A tire reinforcing material 210 and a tire were manufactured in the same manner as in preparation example 4, except that in the formation of the rubber compound layer 230, a rubber compound solution was prepared by dispersing an elastomer composition in a mixed solvent at a concentration of 25%, and the thickness t1 of the rubber compound layer 230 was 23 μm.

< preparation example 7>

A tire reinforcing material 210 and a tire were manufactured in the same manner as in preparation example 4, except that in the formation of the rubber compound layer 230, a rubber compound solution was prepared by dispersing an elastomer composition in a mixed solvent at a concentration of 35%, and the thickness t1 of the rubber compound layer 230 was 30 μm.

< comparative example 5>

A tire reinforcing material 210 and a tire were manufactured in the same manner as in preparation example 4, except that rubber having a thickness of 1.6mm was disposed on the adhesive layer 220 on the textile substrate 210 and rolled to form a rubber reinforcing material, without forming the rubber compound layer 230 using a rubber compound solution.

< comparative example 6>

A tire reinforcing material 210 and a tire were manufactured in the same manner as in preparation example 4, except that the process of forming the rubber compound layer 230 was omitted.

< comparative example 7>

A tire reinforcing material 210 and a tire were manufactured in the same manner as in preparation example 4, except that in the formation of the rubber compound layer 230, a rubber compound solution was prepared by dispersing an elastomer composition in a mixed solvent at a concentration of 5%, and the thickness t1 of the rubber compound layer 230 was 4 μm.

< comparative example 8>

A tire reinforcing material 210 and a tire were manufactured in the same manner as in preparation example 4, except that in the formation of the rubber compound layer 230, a rubber compound solution was prepared by dispersing the elastomer composition in a mixed solvent at a concentration of 40%.

< test example >

(1) Thickness measurement

The thickness of the rubber compound layer 230 manufactured in the preparation examples 1 to 7 and the comparative examples 1 to 8 was measured using a Mitutoyo Vernier Caliper (Mitutoyo Vernier Caliper).

(2) Tack Strength test

The rubber reinforcing materials manufactured in production examples 1 to 3 and comparative examples 1 to 4 were laminated on an unvulcanized rubber (thickness: 1.3mm) for a carcass layer, and the rubber reinforcing materials manufactured in production examples 4 to 7 and comparative examples 5 to 8 were laminated on an unvulcanized rubber (thickness: 1.3mm) for a belt layer. At this time, in order to compress the unvulcanized rubber and the rubber reinforcing material, the rubber reinforcing material was pressed three times using a metal columnar weight with a load of 5kgf to prepare a pressure-sensitive adhesive layer composite, and then cut to manufacture a test piece with a width of 1 inch. Next, a transparent adhesive tape (Scotch tape, TM) was attached to the exposed surface of the rubber reinforcing materials manufactured in production examples 1 to 7 and comparative examples 1 to 8 so as to prevent the test specimen from being stretched, and then the adhesive strength of the rubber reinforcing materials manufactured in production examples 1 to 7 and comparative examples 1 to 8 was measured by a PEEL-off (PEEL) test method using Instron clamp (Grip, cat.no. 2712-041). At this time, the crosshead speed was 125 mm/min. The tack strength is expressed in units of "N/inch".

(3) Adhesion Strength (PEEL) test

The adhesive peel strength of the rubber-reinforced materials manufactured in production examples 1 to 7 and comparative examples 1 to 8 on the carcass layer of the tire was measured in accordance with ASTM D4393, American society for testing and materials test Standard. Specifically, a 1.6mm thick rubber sheet, cord paper, each of the rubber reinforcing materials manufactured in production examples 1 to 7 and comparative examples 1 to 8, a 1.6mm thick rubber sheet, cord paper, and a 1.6mm thick rubber sheet were laminated in this order to prepare a sample, which was then subjected to 60kg/cm at 160 ℃²For 20 minutes under pressure. Next, the vulcanized sample was cut to prepare a test piece having a width of 1 inch. The thus-prepared test specimens were subjected to a peel test at 25 ℃ at a rate of 125mm/min using a general-purpose testing machine (Instron co., Ltd.), and then the adhesive peel strength of the rubber reinforcing materials produced in production examples 1 to 7 and comparative examples 1 to 8 on the carcass layer was measured. At this time, the average value of the load generated at the time of peeling was calculated from the adhesive strength. The bond strength is expressed in units of "N/inch".

(4) Weight index of rubber reinforcing material

The weights of 20 rubber reinforcing materials respectively manufactured in production examples 1 to 7 and comparative examples 1 to 8 were measured, an average value was found, and then comparison was made.

(5) Weight index of tire

In preparation examples 1 to 7 and comparative examples 1 to 8, 20 tires were manufactured, respectively. The weight of the tires thus manufactured was measured and averaged.

(6) Defect rate in tire manufacture

The incidence of defects in the manufacturing processes according to preparation examples 1 to 7 and comparative examples 1 to 8 was investigated. Due to the characteristics of the tire manufacturing process, when the rubber reinforcing material maintains the adhesive strength above a certain level, the rubber reinforcing material can be adhered to the rubber without causing a phenomenon of dropping to proceed up to the tire manufacturing process. If the adhesive strength of the rubber reinforcing material is not above a certain level, defects due to falling down during the tire manufacturing process may occur. In addition, if air pockets occur in the rubber compound layer, interfacial separation may occur in the rubber compound layer, resulting in tire defects.

20 tires were manufactured for each of the production examples 1 to 7 and the comparative examples 1 to 8, and whether defects exist was confirmed, and the defect rate in the tire manufacturing process was obtained according to the following formula 1.

[ formula 1]

Tire manufacturing defect rate (%) ([ (number of good quality tires)/(20, number of tires evaluated) ] × 100

The results of the above measurements are shown in tables 1 and 2 below.

[ TABLE 1]

[ TABLE 2 ]

Referring to table 1, it can be seen that, in the case of preparation examples 1 to 3 according to the present invention, the thickness of the rubber compound layer 230 was reduced by 90% or more as compared to comparative example 1 according to the conventional method, and, although the thickness of the rubber compound layer 230 was reduced, they also had excellent adhesive strength and equivalent level or higher adhesive strength. In addition, it was confirmed that the tires according to production examples 1 to 3 were lighter in weight than the tire according to comparative example 1 by 0.39kg to 0.45 kg.

On the other hand, the rubber-reinforced materials according to production examples 1 to 3 had excellent adhesive strength as compared with the rubber-reinforced materials of comparative examples 2 and 3, and thus the defect rate in the tire manufacturing process was greatly reduced. Further, it was confirmed that, in the tire manufacturing process, the occurrence of air pockets was reduced as compared with comparative example 4, thereby reducing the defect rate in the tire manufacturing. In the case of comparative example 4, a high defect rate was exhibited due to the occurrence of air pockets, and thus had a greater weight than that of production examples 1 to 3.

Referring to table 2, it can be seen that, in the case of preparation examples 4 to 7 according to the present invention, the thickness of the rubber compound layer 230 was reduced by 95% or more as compared to comparative example 5 according to the conventional method, and, although the thickness of the rubber compound layer 230 was reduced, it had the same level of adhesive adhesion and adhesive strength. In addition, it was confirmed that the tires according to production examples 4 to 7 were lighter in weight than the tire according to comparative example 5 by 0.39kg to 0.41 kg.

On the other hand, the rubber-reinforced materials according to production examples 4 to 7 had excellent adhesive strength as compared with the rubber-reinforced materials of comparative examples 6 and 7, so that the defect rate in the tire manufacturing process was greatly reduced. In the case of comparative example 6, since the rubber compound layer 230 was not formed, the adhesive strength thereof was low. In the case of comparative example 7, the rubber compound layer 230 was made of a rubber compound solution containing a low concentration of the elastomer composition, and the rubber compound layer 230 had a thin thickness of 4 μm and a low adhesive strength.

In addition, it was confirmed that, in the case of comparative example 8, the rubber compound layer 230 was made of a rubber compound solution containing a high concentration of the elastomer composition, and the thickness of the rubber compound layer was not uniform in the range of 180 to 230 μm, the occurrence of air pockets was increased during the tire manufacturing process, and the defect rate during the tire manufacturing process was greatly increased, as compared to the case where the reinforcing materials manufactured in preparation examples 4 to 7 were used.

[ description of reference numerals ]

10: the tread 20: tire shoulder

30: sidewall 40: tire bead

50: belt layer 60: inner liner

70: carcass 80: groove

90: cap ply layer 101: tyre for vehicle wheels

110: ply twisted yarn

111: first as-twisted yarn

112: second as-twisted yarn

201: rubber reinforcing material

210: textile substrate

220: adhesive layer

230: rubber compound layer