KR102371139B1 - Pneumatic tire - Google Patents

Abstract

The present invention relates to a pneumatic tire, and more specifically, to a pneumatic tire which improves electric conductivity in the tire to prevent an accident of a vehicle due to static electricity generation. In the pneumatic tire according to one embodiment of the present invention, a belt layer is laminated on an upper side of a carcass ply inside a tread unit, a plurality of air vent yarns are arranged at regular intervals between the carcass ply and the belt layer, and at least a part of the plurality of air vent yarns is made of conductive air vent yarn.

Description

Pneumatic tire

The present invention relates to a pneumatic tire, and more particularly, to a pneumatic tire which improves electrical conductivity and breathability in the tire, thereby preventing accidents due to static electricity generation in a vehicle in advance.

Unless otherwise indicated herein, the material described in this section is not prior art to the claims of this application, and inclusion in this section is not an admission that it is prior art.

When refueling a car, there is a possibility that a fire may occur due to the driver's static electricity. In particular, in dry changing seasons or in winter, static electricity is generated by touching the fuel nozzle or the fuel port, and in severe cases, a spark may occur with a sparking sound, which may lead to a fire. However, the vehicle also needs a means to prevent static electricity.

In order for a vehicle to conduct electricity, the tire is the part that makes contact with the road surface, so inevitably, electricity must also pass through the tire. Conventionally, electricity was induced to flow through the side rubber of the tire, but there was a limit to having electrical conductivity while maintaining the physical properties of the side rubber. In order to overcome the above limitation, research to allow electricity to pass through other rubber and semi-finished products of tires is continuously being conducted, and technologies for inserting a conductive cord to pass electricity from the tread to the rim are being developed. .

The conductive cord is manufactured by coating PET or nylon fiber with carbon black or a metal solution, and its breathability is significantly lower than that of cotton yarn used as an air vent yarn. In the process of forming a pneumatic tire, a semi-finished belt product for forming a belt layer is wound on the upper side of the carcass ply and attached to each other. can't

In this regard, Korean Patent Registration No. 10-2007869 of the same applicant discloses an invention for preventing static electricity accidents in automobiles by forming an air vent yarn having electrical conductivity inside the tread of a tire. More specifically, "a belt layer is laminated on the upper side of the carcass ply inside the tread part, and a plurality of air vent yarns are arranged at regular intervals between the carcass ply and the belt, and at least some of the air vent yarns are By forming a gap between the carcass ply and the belt to be electrically conductive, static electricity generated in the body of the vehicle is discharged through the tread grounded to the road surface via the carcass ply electrically connected to the tire wheel. discloses a pneumatic tire that can prevent accidents that may occur due to static electricity in advance.

However, in the process of applying the conductive carbon yarn to have electrical conductivity to the field through the registered patent of the same applicant, there is no problem in normal times, but there is a problem that the process humidity rises during the rainy season, such as the summer monsoon season, resulting in defective air intake. there was. In particular, the conductive carbon yarn coated with carbon has no air permeability and only has electrical conductivity, so when the process humidity increases, the possibility of air inlet failure is high, so it cannot be applied to all pneumatic tires and has a problem that it must be applied only to some standards. In addition, as it is vulnerable to defects, it has technical limitations in terms of lowering productivity and expanding application of various production conditions due to low temperature and long-time vulcanization to reduce air intake defects.

1. Korean Patent Registration No. 10-2007869 (2019.07.31. Announcement)

In order to improve the electrical conductivity in the tire, the use of conductive cord is minimized, and electrical conductivity is given so that a part of the existing air vent yarn can be used instead, and a belt semi-finished product for forming a belt layer on the upper side of the carcass ply during the tire forming process. After winding and attaching the tires, the function as an air vent company to discharge the air between them in the process of pressing and fixing them to the outside provides stable electrical conductivity without additional equipment investment during the tire manufacturing process. We want to provide pneumatic tires that can be secured.

In addition, it is not limited to the technical problems as described above, and it is obvious that another technical problem may be derived from the following description.

In the pneumatic tire according to an embodiment of the present invention, a belt layer is laminated on the upper side of the carcass ply inside the tread portion, and a plurality of air vent yarns are arranged at regular intervals between the carcass ply and the belt layer, At least some of the plurality of air vent yarns are made of conductive air vent yarns.

According to a preferred feature of the present invention, the conductive air vent yarn is characterized in that it is composed of a carbon coating yarn having electrical conductivity and an air vent yarn braided.

According to a preferred feature of the present invention, the thickness of the carbon coating yarn (Denier) is made of 100D to 300D, it is characterized in that the thickness of the conductive air vent yarn consists of 20 to 50 numbers.

According to a preferred feature of the present invention, the conductive air vent yarn is made in a braiding method in which the air vent yarn is twisted spirally along the long axis direction of the carbon coating yarn, and the number of twists of the conductive air vent yarn to be braided is 20 TPM to 50 TPM. characterized.

According to a preferred feature of the present invention, the carbon-coated yarn is made of any one of nylon yarn and PET yarn, and the surface of the carbon-coated yarn is characterized in that it consists of a carbon coating layer formed by coating liquid carbon.

According to a preferred feature of the present invention, N ₂ SA of the liquid carbon is characterized in that it consists of 83 to 125 (m ² /g).

According to a preferred feature of the present invention, DBP (Dibutyl Phthalate) of the liquid carbon is characterized in that it consists of 70 to 125 (cm ³ /100g).

According to a preferred feature of the present invention, the liquid carbon is characterized in that it contains 50 to 60% by weight of water, 37 to 43% by weight of carbon black, and 1 to 5% by weight of a surfactant.

According to the embodiment of the present invention, electrical conductivity is secured through the conductive air vent yarn arranged between the carcass ply and the belt layer, so that static electricity generated inside the vehicle is electrically connected to the tire wheel via the carcass ply to the road surface. It is possible to prevent accidents that can occur due to static electricity in the vehicle by discharging it through the tread grounded to the vehicle, and at the same time, the air vent and the conductive air vent with a twisted structure of the carbon coating company secure the air permeability of the tire. During the molding process during the manufacturing process, the semi-finished belt product for forming the belt layer on the upper side of the carcass ply is wound and attached, and then the air between them can be easily discharged to the outside in the process of pressing and fixing the work. .

It should be understood that the effects of the present invention are not limited to the above-described effects, and include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

1 is a partial front sectional view of a pneumatic tire according to an embodiment of the present invention;
Figure 2 is an enlarged cross-sectional view of part A of Figure 1;
3 is a schematic diagram illustrating a process in which liquid carbon is coated on the surface of a carbon-coated yarn in a pneumatic tire according to an embodiment of the present invention;
Figure 4 is a schematic view showing the process of braiding the conventional carbon coating and air vent.
5 is a schematic view showing a process of braiding a carbon-coated company and an air vent company in a pneumatic tire according to an embodiment of the present invention;
6 is a schematic view showing a test method for confirming the presence or absence of air permeability of a conductive air vent yarn in a pneumatic tire according to an embodiment of the present invention;

Hereinafter, with reference to the accompanying drawings, look at the configuration, operation and effect of the pneumatic tire according to the preferred embodiment. For reference, in the following drawings, each component is omitted or schematically illustrated for convenience and clarity, and the size of each component does not reflect the actual size. In addition, the same reference numerals refer to the same components throughout the specification, and reference numerals for the same components in individual drawings will be omitted.

1 is a partial front sectional view of a pneumatic tire according to an embodiment of the present invention, and FIG. 2 is an enlarged view of part A of FIG. 1 .

In the pneumatic tire 1 according to an embodiment of the present invention, the belt layer 5 is laminated on the upper side of the carcass ply 6 inside the tread 2, and the carcass ply 6 and the A plurality of air vent yarns 62 are arranged at regular intervals between the belt layers 5 , and at least some of the plurality of air vent yarns 62 are made of conductive air vent yarns 64 .

1 and 2, in the pneumatic tire 1, the sidewall part 3 and the bead part 4 are sequentially extended to be symmetrical with each other in the width direction from both sides around the tread part 2 is formed The inner liner 7 and the carcass ply 6 are sequentially stacked inside the tread part 2, the sidewall part 3 and the bead part 4, and in particular, the carcass ply inside the tread part 2 (6) The belt layer 5 is laminated|stacked on the upper side. Inside the carcass ply 6, a plurality of rolled yarns 61 (fabric cord) arranged radially in the width direction of the pneumatic tire 1 are arranged to be spaced apart by a predetermined interval along the circumferential direction. Between the carcass ply 6 and the belt layer 5, a plurality of air vent yarns 62 are configured to be radially arranged at regular intervals like the rolled yarns 61 described above. Here, the air vent yarn 62 is present between the semi-finished belt products for forming the belt layer 5 on the upper side of the carcass ply 6 in the tire forming process, and then in the process of pressing and fixing them to each other. It serves as a passage through which the air to be exhausted can be exhausted to the outside.

According to an embodiment of the present invention, at least one or more air vent yarns 62 selected from among the air vent yarns 62 are electrically energized between the carcass ply 6 and the belt layer 5 so as to be able to conduct electricity. It is made of a conductive air vent yarn 64 having conductivity.

The conductive air vent yarn 64 is to have electrical conductivity by including the carbon coating yarn 63 to be described later, and through the conductive air vent yarn 64 including the carbon coating yarn 63, the carcass fly ( By allowing the current flowing to 6) to flow to the belt layer 5, static electricity generated in the vehicle can be discharged to the ground through the tire 1, thereby preventing the generation of static electricity in the vehicle.

According to a preferred feature of the present invention, the conductive air vent yarn 64 is characterized in that the carbon coating yarn 63 and the air vent yarn 62 having electrical conductivity are braided together.

When the conductive air vent yarn 64 is made of only the carbon-coated yarn 63 having electrical conductivity, the conductive carbon yarn coated with carbon does not have air permeability and has only electrical conductivity. Due to its vulnerability to generation, it has technical limitations in terms of reduced productivity and expanded application of various production conditions due to low temperature and long-term vulcanization to reduce air intake defects. According to an embodiment of the present invention to solve this problem, the carbon coating yarn 63 is provided with not only electrical conductivity but also breathability due to the conductive air vent yarn 64 formed by braiding the air vent yarn 62 in the vehicle. The effect of facilitating air discharge in the process of pressing and fixing the belt layer 5 on the upper side of the carcass ply 6 while preventing the generation of static electricity is recognized.

According to a preferred feature of the present invention, the carbon-coated yarn 63 is made of any one of nylon yarn and PET yarn, and the surface of the carbon-coated yarn 63 is formed of a carbon coating layer formed by coating liquid carbon. do it with

3 is a schematic diagram illustrating a process in which liquid carbon is coated on the carbon-coated yarn 63 in the pneumatic tire 1 according to an embodiment of the present invention.

3, after dipping the fiber cord into the liquid carbon contained in the container 8, take it out and dry it using a dryer 81. On the outer peripheral surface of the fiber cord, a carbon coating layer has a predetermined thickness. The carbon-coated yarn 63 that is uniformly formed with

In this embodiment, the air vent yarn 62 may be made of cotton yarn, and the carbon-coated yarn 63 may be made of PET yarn, but is not necessarily limited thereto, and the carbon-coated yarn 63 is nylon yarn. , it is natural that it may be made of any one selected from among PET yarns.

According to a preferred feature of the present invention, the thickness (Denier) of the carbon coating yarn (63) is made of 100D to 300D, and the thickness of the conductive air vent yarn (64) is characterized in that it consists of 20 to 50 numbers.

The conductive air vent yarn 64 is characterized in that the carbon coating yarn 63 and the air vent yarn 62 are braided, and among them, the carbon coating yarn 63 has a thickness of 100D to 300D, and the conductive air The thickness of the bent yarn 64 may be 20 to 50 numbers.

Hereinafter, Tables 1 to 3 show the experimental results for the presence or absence of conductivity and air permeability according to the thickness of the carbon coating yarn 63 and the air vent yarn 62 constituting the conductive air vent yarn 64 .

First, in Table 1, the thickness (Denier) of the carbon coating yarn 63 is configured from 50D to 600D, and as a result of the experiment to check the presence or absence of electrical conductivity according to each thickness, the carbon coating yarn that can uniformly coat the conductive carbon with the minimum tensile load. As for the thickness of (63), 50D to 500D are suitable. Here, when the thickness of the carbon-coated yarn 63 is made less than 50D, it does not reach the minimum tensile load and breaks without enduring the tensile force generated in the carcass ply 6 rolling process, and when it exceeds 500D, the carbon to be described later It is not uniformly coated on the surface of the air vent yarn 62, so it has a variation in electrical conductivity.

carbon coating 50D 100D 170D 200D 300D 400D 450D 500D 550D 600D conductivity ○ ○ ○ ○ ○ ○ ○ ○ X X

Next, as a result of checking the presence or absence of air permeability according to the thickness of the cotton yarn of the air vent yarn 62 constituting the conductive air vent yarn 64 in Table 2, the minimum thickness for air permeability must be 50 or more, and the thickness of the cotton yarn is When the number exceeds 10, when the conductive air vent yarn 64 is positioned between the carcass ply 6 and the inner liner 7 after the pneumatic tire 1 is vulcanized, the thickness of the air vent yarn 62 There is a problem that the conductive air vent yarn 64 can be seen exposed to the inner liner 7 after vulcanization because it is too thick, and there is a disadvantage that it is disadvantageous for the poor air intake due to moisture content in the air, so 10 or less It is preferable to have a thickness of (here, the higher the number, the thicker the cotton yarn thickness means, and the lower the number, the thicker the thickness. Therefore, numerically limiting the thickness of the air vent yarn 62 In terms of things, it is expressed as more than 50 and less than 10).

In order to measure the air permeability, as shown in FIG. 6 , when a conductive air vent yarn 64 is inserted between the rubber 11 layers and nitrogen is passed at a pressure of 50 kpa, the height of the sensor for checking the water level is The degree of air permeability was confirmed by measuring the time it takes to rise by 30 mm, and it means that the longer the time in this method, the lower the air permeability. In addition, the air permeability measurement value of the generally used air vent yarn 62 is made less than 35s, and having a value of 35s or more means that the air permeability is insufficient. As shown in Table 2 below, when the air vent yarn 62 is made up of 60 or more, it can be seen that it has a value of 40 to 51s, which is more than double the value of 40 to 51s, which is more than twice the air permeability of 21 to 23s, which is 50 numbers or more. It can be seen that the ventilation efficiency of the air vent yarn 62 made of

air vent
(cotton yarn) number 60 50 numbers number 40 number 30 number 20 number 10 breathable X ○ ○ ○ ○ ○ 40~51s 21-23s 20-21s 18-22s 15-18s 10-13s

Table 3 shows the experimental results for confirming the presence or absence of electrical conductivity and air permeability according to the thickness and configuration of the conductive air vent yarn 64 in which the carbon coating yarn 63 with the carbon coating layer is formed and the air vent yarn 62 are braided together. As shown in Table 3, when the carbon coating yarn 63 is 100D to 300D and the conductive air vent yarn 64 is made of 20 to 50 numbers, it can be confirmed that electrical conductivity and air permeability can be stably secured. In particular, in terms of air permeability, it can be seen that, in the case of 20 to 50 numbers, the measured values of 9 to 14s to 19 to 22s are obtained, whereas in the case of 60 numbers, it can be seen that the air permeability measured value is significantly increased to 46s. In addition, when the carbon-coated yarn 63 is made of 50D, the carbon-coated yarn 63 satisfies the electrical conductivity before braiding, but does not satisfy the conductivity standard after braiding. will be.

carbon coating 50D 100D 170D 200D 300D air vent number 20 number 30 number 40 50 numbers number 60 conductivity X ○ ○ ○ ○ breathable ○ ○ ○ ○ X 9-14s 17-22s 19-24s 19-22s 46s

Table 4 below shows the electrical resistance index results according to the case in which the air vent yarn 62 having a thickness of 40 was braided to the carbon coating yarn 63 having various thicknesses in the conductive air vent yarn 64 . Here, the carbon coating yarn 63 has a carbon coating layer of carbon grade N330 (N ₂ SA 83 , DBP 101) on a nylon yarn material. Here, the electrical resistance index refers to the number of digits for an integer × 10^ (eg, 5.1 × 10^5), and the preceding integer is omitted under the judgment of measurement deviation. For example, 5.1×10^5 and 5.9×10^5 can be judged to have similar electrical resistance on the tire.

As shown in Table 4, in general, the electrical resistance index of a conventional tire to which nylon yarn (Raw Cord) is applied is 8 level. In the conductive air vent yarn 64 according to an embodiment of the present invention, the carbon coating yarn ( 63), since the electrical resistance index is less than 8 in the range of 5 to 7, when the thickness is 100D to 300D, it can be confirmed that it has sufficient electrical conductivity to prevent static electricity.

Conductive Air Vent
(Carbon coating company + Air vent company) 50D+40 number 100D+40 water 200D+40 water 300D+50 number electrical resistance index
(10^Ω) >8 6-7 5-6 5-6

According to a preferred feature of the present invention, the conductive air vent yarn 64 is made in a braiding method in which the air vent yarn 62 is twisted spirally along the long axis direction of the carbon coating yarn 63, and the conductive air vent yarn 62 is braided. The twist number of the air vent yarn 64 is characterized in that it consists of 20 TPM to 50 TPM.

In the conventional method using only the carbon coating yarn 63, the role of the carbon coating yarn 63 as an air vent yarn is incomplete. After winding and attaching the semi-finished belts, there was a limit to their role as a passage through which the air between them could be discharged to the outside in the process of pressing and fixing them. In order to solve this, as shown in FIG. 4, the plying of the carbon coated yarn 63 and the air vent yarn 62 (the carbon coated yarn 63 and the air vent yarn 62 cross each other and twist in a spiral) method) to form the conductive air vent yarn 64, but in this twisting method, there was a problem in that the performance as a conductive yarn was deteriorated due to the loss of the amount of carbon black coated during the process of twisting different types of fibers.

Accordingly, as shown in FIG. 5, by locating the carbon coating yarn 63 in the center and twisting the air vent yarn 62 in a spiral based on the long axis direction of the carbon coating yarn 63, the coating Without loss of carbon black, it is possible to simultaneously give the role of energization and air vent.

6 is a test method devised to check the air permeability of the conductive air vent yarn 64, in which a plurality of conductive air vent yarns 64 are arranged side by side at regular intervals, and these plurality of conductive air vent yarns 64 A layer of rubber 11 is located at the top and bottom with a gap between them, and moisture is deposited on the surface of the rubber 11 in contact with the conductive air vent yarn 64 and vulcanized after vulcanization. was confirmed about

Table 5 below shows the experimental results of the electrical resistance index according to the difference in the twisting process of the conductive air vent yarn 64.

As shown in Table 5, in the braiding process of the carbon-coated yarn 63 and the air vent yarn 62, that is, the twisting process, as shown in FIG. It can be confirmed that the value has a lower electrical resistance index compared to that taken in the method of FIG. 4 and thus the electrical conductivity is higher.

twist method Fig. 4 scheme Fig. 5 scheme Number of samples (N) One 2 3 4 One 2 3 4 Electrical resistance index (10^Ω) 7-8 7-8 7-8 7-8 4-5 4-5 4-5 4-5

In Table 6 below, in the conductive air vent yarn 64 according to an embodiment of the present invention, the electrical resistance index according to the number of twists (TPM) between the carbon coating yarn 63 and the air vent yarn 62 is shown. The experimental results are shown.

As shown in Table 6, when the number of twists (TPM) is 50 TPM or more, it can be confirmed that the electrical resistance index is sharply increased compared to 40 TPM, so that the electrical conductivity is lowered (in the case of 40 TPM, the electrical resistance index is 10 ^{4 ~ 6} Ω , In the case of 50TPM, the electrical resistance index is 10 ^7-8 Ω), and in the case of less than 20TPM, the twist between the carbon coating yarn 63 and the air vent yarn 62 is not stable, so it is preferably made of 20TPM to 40TPM.

Twists (TPM) 10 20 30 40 50 60 Electrical resistance index (10^Ω) 4-5 4-5 4-5 4-6 7-8 7-8

In addition, according to a preferred feature of the present invention, N ₂ SA of the liquid carbon is made up of 83 to 125 (m ² /g), and DBP (Dibutyl Phthalate) of the liquid carbon is 70 to 125 (cm ³ / g) 100 g).

Here, N ₂ SA represents the surface area where N ₂ molecules can be adsorbed to carbon. If N ₂ SA is low, it means that the surface area is small and the minimum particle size that can be broken is large, and if N ₂ SA is high, the surface area of carbon is high. It means that the surface area is large and the minimum breakable particles are small.

Here, when the N ₂ SA is less than 83 m ² /g, the carbon minimum particle is too large, so even if it is applied to the conductive air vent yarn 64, the phenomenon of falling from the yarn (the phenomenon of blowing carbon)

As a result, the electrical conductivity of the conductive air vent yarn 64 on which the carbon coating layer 63 is formed appears too low, and when N ₂ SA exceeds 125 m ² /g, inter-particle agglomeration is strong and dispersion is not good, so the carbon coating layer 63 ), a deviation occurs in the electrical conductivity value of the conductive air vent yarn 64 formed thereon.

In addition, DBP (Dibutyl Phthalate) indicates the degree of structural development of the minimum particle size of carbon, and the larger the value, the greater the development. Therefore, the more the structure develops, the more oil is absorbed between the particles, and the lower the electrical resistance, the better the electricity flows.

Here, when the DBP is less than 70 (cm ³ /100g), the carbon particle size becomes very large (N990 Grade), and the electrical conductivity decreases due to the phenomenon of carbon flying when applied, and when the DBP is more than 125 (cm ³ /100g), the above-described N ₂ The specific surface area of carbon according to SA is very high (N134 Grade), so the aggregation between carbon particles is strong and dispersion is difficult.

According to a preferred feature of the present invention, the liquid carbon is characterized in that it contains 50 to 60% by weight of water, 37 to 43% by weight of carbon black, and 1 to 5% by weight of a surfactant.

Here, when the carbon black exceeds the range of 43% by weight, the liquid carbon for forming the carbon coating layer is too viscous, so carbon agglomeration occurs, water is 60% by weight, and surfactant is 5% by weight ( If the range of 7% by weight) is exceeded for other medicinal materials including surfactants, the carbon black becomes too diluted to 37% by weight or less, and electrical conductivity is low even when carbon is coated, so it is meaningless. Sufficient electrical conductivity can be ensured by the carbon coating layer 63 coated with liquid carbon.

Although preferred embodiments of the present invention have been described with reference to the accompanying drawings, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention and represent all of the technical spirit of the present invention. Therefore, it should be understood that there may be various equivalents and modifications that can be substituted for them at the time of filing the present application. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is indicated by the following claims rather than the detailed description, and the meaning and scope of the claims and their All changes or modifications derived from the concept of equivalents should be construed as being included in the scope of the present invention.

1: Pneumatic tire
2: tread part
3: side wall part
4: bead part
5: belt layer
6: Carcass fly
7: Inner liner
8 : courage
61: rolled yarn
62: air vent company
63: carbon coating yarn
64: conductive air vent company
65: fiber cord
81: dryer
9: axis of rotation
11: rubber

Claims (5)

A belt layer is laminated on the upper side of the carcass ply inside the tread,
A plurality of air vent yarns are arranged at regular intervals between the carcass ply and the belt layer,
At least some of the plurality of air vent yarns are made of conductive air vent yarns,
The conductive air vent company,
It is composed of a carbon coating yarn with electrical conductivity and an air vent yarn,
The air vent yarn is made in a braiding method in which the carbon coating yarn is twisted spirally along the long axis direction,
The pneumatic tire, characterized in that the number of twists of the conductive air vent yarn to be braided is 20 TPM to 40 TPM. delete According to claim 1,
The thickness of the carbon coating yarn (Denier) is made of 100D to 300D,
The thickness of the conductive air vent yarn is a pneumatic tire, characterized in that consisting of 20 to 50 numbers. delete According to claim 1,
The carbon coating yarn is made of any one of nylon yarn and PET yarn,
The surface of the carbon coating yarn is a pneumatic tire, characterized in that consisting of a carbon coating layer formed by coating liquid carbon.

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