KR101475225B1 - Tire cord and tire comprising the same - Google Patents

Abstract

The present invention relates to a tire cord and a tire comprising the tire cord, wherein the tire cord comprises nettle fibers. The tire cord replaces a steel cord to reduce the weight of the tire and prevent environmental pollution, while securing physical properties equal to or higher than that of the steel cord and improving the running performance.

Description

TIRE CORD AND TIRE COMPRISING THE SAME "

The present invention relates to a tire cord and a tire including the tire cord. More specifically, the present invention relates to a tire cord and a tire including the same, And a tire including the tire cord.

In order for the tire to exhibit sufficient durability, it is necessary to reinforce its strength or rigidity with various reinforcing materials. In general, reinforcing materials used in automotive tires include fiber cords and steel cords. The fiber cord has a relatively small weight, a good ride quality, and a high adhesion to rubber, but has low strength and heat resistance. On the other hand, the steel cord has a high strength, but has a disadvantage in that the adhesive strength with rubber is low and the weight is heavy.

Further, in the tire cord, the strength and durability of the tire cord are gradually improved as the organic fibers such as cotton, rayon, nylon or polyester appear in succession. After that, high-strength steel cords appeared to improve the running speed and steering stability of tires. Recently, fiberglass such as high-strength organic fiber has been continuously developed.

On the other hand, the global automobile market is trying to reduce the weight of vehicles in order to cope with eco-friendly technology, such as high oil prices and environmental problems. In line with this, the tire market is also trying to develop lighter tires. Particularly, among the materials constituting the tire, the tire cord occupies 9 to 12% by weight in the case of PCR (Passenger Car Radial) tire and 12 to 15% by weight in the case of TBR (Truck Bus Radial)

In addition, the steel cord causes environmental pollution when the tire is discarded. Therefore, it is necessary to develop an environmentally friendly code while exhibiting the same level of physical properties as those of the high-strength steel cord.

Korean Patent Publication No. 2013-0024054 (Publication date: March 3, 2013) Korean Patent Publication No. 2013-0010723 (Published on 2013.01.29) Korea Public Patent No. 2012-0071810 (Published on July 3, 2012)

An object of the present invention is to provide a tire cord which can replace a steel cord to make the tire lighter and prevent environmental pollution, ensure a physical property equal to or higher than that of the steel cord, and improve running performance.

Another object of the present invention is to provide a tire comprising the tire cord.

In order to achieve the above object, a tire cord according to an embodiment of the present invention includes nettle fibers.

The surface of the nettle fibers may be modified with a carboxylic acid group.

The nettle fiber may be surface-modified with 1 to 4 parts by weight of organic acid per 10 parts by weight of the nettle fiber.

The nettle fibers may have a diameter of 0.05 to 0.3 mm.

A tire according to another embodiment of the present invention includes the tire cord.

The tire cord may be arranged at 20 to 36 EPI (ends per inch) intervals.

Hereinafter, the present invention will be described in more detail.

The tire cord comprises nettle fibers.

The scientific name of the nettle is Urtica dioica , grows in temperate and tropical wastelands, and can grow to 2 to 4 meters in height. The leaves begin to grow from early spring, the leaves are roughly 10cm long, with a rough heart shape, one end round and the other end long and sharp. There are large serrations on the edges of the leaves, and the leaves and stems are covered with fur. The peduncle comes out from the upper part of the larva, and the flower runs on the end of the cone when it is from June to October. Male flowers are mainly gathered on the upper side, female flower is gathered on the lower side, and moisture (powder receiver) is made by wind. When the skin touches the flecks or spikes on the leaves or stems of the nettle, the blisters may form very badly.

The nettle fiber is a woven fabric obtained by processing celluloid extracted from the stem of a nettle. The nettle fiber has a very high tensile strength and has the same physical properties as steel cords and is very light. Therefore, when the netting fiber is used as the tire cord in place of the steel cord, the tire can be lightened and environmental pollution can be prevented, property of a level equal to or higher than that of the steel cord can be secured, and driving performance can be improved .

The nettle fiber can be used by modifying the surface of the nettle fiber with a carboxylic acid group. Natural fibers such as the nettle fibers are vulnerable to use as tire cords because of their high water absorbency. The water absorption problem can be solved by modifying the surface of the nettle fiber with the carboxylic acid group.

Specifically, the nettle fiber may be surface-modified with 1 to 4 parts by weight of organic acid per 10 parts by weight of the nettle fiber. When the surface of the nettle fiber is modified with the organic acid, the water absorption problem of the nettle fiber can be solved, and the affinity with the rubber can be further increased.

The organic acid is specifically selected from the group consisting of oleic acid, linoleic acid, lauric acid, pentadecylic acid, margaric acid, palmitic acid, stearic acid, and a combination thereof. Stearic acid may be preferably used.

The nettle fiber may be surface-modified with 1 to 4 parts by weight of the organic acid per 10 parts by weight of the nettle fiber. If the content of the organic acid is less than 1 part by weight, the effect of increasing the affinity with the rubber due to surface modification is hardly effected. If the content of the organic acid is more than 4 parts by weight, the effect of improving tire physical properties and running performance may be impaired.

The nettle fibers may have a diameter of 0.05 to 0.3 mm. If the diameter of the nettle fiber is less than 0.05 mm, there may be a problem of cohesion between fibers. If the diameter is more than 0.3 mm, it may be a starting point of cracking during repetitive motion.

According to another embodiment of the present invention, there is provided a tire including the tire cord. 1 is a cross-sectional view schematically showing a cross section of the tire.

1, the tire 200 includes a tread portion 210, a side wall portion 220, a belt portion 230, a carcass portion 240, and an inner liner portion 250. The tire cord may be applied to the tread portion 210, the side wall portion 220, the belt portion 230, the carcass portion 240, or the inner liner portion 250 as a reinforcing material, (230). The structure of the tire 200 is not limited to the above structure, and all structures of conventional tires can be applied.

The tread portion 210 transmits the driving force and the braking force of the automobile to the road surface, and includes a cap tread 211 and an under tread 212. The site wall 220 serves as an intermediate position for protecting the carcass part 240 from an external shock and transmitting the movement of the steering wheel to the tread part 210 via a bead (not shown). The belt part 230 includes a belt for adjusting the performance of a road surface grounding force and handling and a reinforcing cap fly for preventing separation between the steel belt layers and a belt cushion can do. That is, the belt unit 230 may use a tire cord including the nettle fiber by replacing the steel cord as the belt.

The carcass part 240 serves as a skeleton that forms the skeleton of the tire and maintains the air pressure together with the inner liner 250 to support a load added from the outside. The inner liner 250 functions to maintain the air pressure inside the tire.

The tire 200 may be a racing tire, but the present invention is not limited thereto. The tire 200 may be a tire for an automobile, an airplane tire, an agricultural machine tire, an off-the-road tire, A tire, a truck tire, or a bus tire. Also, the tire 200 may be a radial tire or a bias tire.

The tire cord of the present invention can substitute for a steel cord to secure a physical property equal to or higher than that of the steel cord while reducing the weight of the tire and preventing environmental pollution and improve driving performance.

1 is a cross-sectional view schematically showing a cross section of a tire according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[ Experimental Example : Performance evaluation of tire]

Tire cords were arranged at regular intervals as shown in Table 1 below, and the tire belts were rolled, and the tires (240 / 640R18 F200) were manufactured using the tire cords.

Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Example 5 Steel cord 24 EPI - - - - - Nettle fiber ⁽¹⁾ - 20 EPI 24 EPI 28 EPI 32 EPI 36 EPI

(1) Nettle fibers: nettle fibers having a surface modified with a carboxylic acid group and having a diameter of 0.05 to 0.3 mm

Comparative Example 1 Example 1 Example 2 Example 3 Example 4 Example 5 Rolling performance 5 9 9 9 9 9 Adhesion between belt and cord 6 8 8 8 9 9 Initial grip performance 6 10 9 8 8 8.5 Late grip performance 2 10 8 7 6 6 Endurance performance 100 120 132 134 139 145

- Rolling performance was measured by checking the degree of topping (cord exposure level) during operation and by giving a low score when exposure was excessive or blooming occurred during rolling.

* Rolling Performance Score Table: 1 (very bad) ~ 10 (very good)

- The adhesion between the belt and the cord was measured by the adhesion test between the rubber belt and the cord (drawing test).

* Adhesion Score Table: 1 (very bad) ~ 10 (very good)

- The grip performance was evaluated by measuring the lap time of each running after 10 consecutive circuit courses (2 km) in dry conditions under test conditions with the air pressure of 200 kPa, and evaluating the initial grip performance and the sustainability of the grip performance.

* Grip Performance Score Table: 1 (very bad) ~ 10 (very good)

- The durability was measured by JIS K6264.

As shown in the above Table 2, compared with the comparative example using steel cord, the rolling performance of the embodiment using the nettle fiber was excellent, and in particular, the nettle fiber had excellent basic properties and the fiber diameter was small, It is possible to confirm that the durability and grip performance of the tire are improved.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

200: Tire
210:
211: cap tread 212: under tread
220: side wall part
230:
240: Kakasubu
250: Inner liner part

Claims (6)

A tire cord comprising nettle fibers woven by processing celluloid extracted from the stem of a nettle. The method according to claim 1,
Wherein the nettle fibers are surface modified with a carboxylic acid group. 3. The method of claim 2,
Wherein the nettle fiber is a surface modified with 1 to 4 parts by weight of organic acid per 10 parts by weight of the nettle fiber. The method according to claim 1,
Wherein the nettle fibers have a diameter of 0.05 to 0.3 mm. A tire comprising the tire cord according to claim 1. 6. The method of claim 5,
Wherein the tire cord is arranged at 20 to 36 EPI (ends per inch) intervals.

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