A conductive pneumatic tire

Abstract

The present invention relates to the field of tires, and particularly to a conductive pneumatic tire. The tire includes a tread portion, a sidewall portion, a bead portion, and a conductive film; the bead portion is provided with bead conductive rubber, and when the tire is mounted on a rim, the bead conductive rubber contacts the rim; the tread portion is provided with a conductive belt layer, a conductive chimney rubber, and tread conductive rubber, both ends of the conductive film are respectively connected to the bead conductive rubber and one end of the belt layer, and the other end of the belt layer is connected to one end of the chimney rubber through the tread conductive rubber; the radially outer surface of the tread portion is used to contact the ground, and the other end of the chimney rubber passes through the tread portion and exposes the radially outer surface of the tread portion; the resistance value of the chimney rubber is A, the resistance value of the belt layer is B, and the resistance value of the conductive film is C, and the following relationship is satisfied among the three. This tire improves the conductive performance of the tire and reduces the resistance value of the entire tire.

Description

Technical Field

[0001] The invention relates to the field of tires, and in particular to a conductive pneumatic tire. Background Art

[0002] Most car tires are made of rubber, which is an insulating material. Most tires today use white carbon black, which has a high resistivity. The static charge generated by the friction between the tire and the ground is easy to accumulate inside the tire and is not easy to discharge. Once static electricity is generated while the car is driving, when the person in the car touches the metal of the car with his hand after getting off the car, the static electricity carried by the car begins to discharge to the ground, causing road safety accidents. Generally speaking, there are two sources of static electricity in cars: one is the friction between the tires and the ground; the other is the friction between the car and the air.

[0003] There are several normal modes of static discharge: one is to add iron chains to the vehicles carrying oil tanks or other hazardous chemicals. When the oil tanker is transporting, the oil will rub against the barrel wall to generate electricity. A chain is dragged behind the oil tanker and dropped on the road to transfer the generated charge to the ground in time so that the static charge can be removed at any time, so as to avoid the risk of explosion. The advantages of this static discharge mode are low cost and easy installation; the disadvantages are high noise and easy damage to the road surface. One is to add a tire anti-static device in the car, but the effect of this static discharge is unstable. One is to use tire conductivity. The current tire technology has a high SiO2 content in rubber and poor tire conductivity. By changing the tire structure and adding conductive rubber strips, the static electricity of the tire can be eliminated. This static discharge mode changes the structure of the tire. The outer side of the shoulder and the outer surface of the groove of the tire are still in contact with the ground, which has a long-term anti-static effect.

[0004] like Figure 1 The figure shows a schematic diagram of the structure of an existing tire, which includes a tread portion 1, a sidewall portion 2, a bead portion 3 and a conductive rubber sheet 4; the tread portion 1 is provided with a conductive belt layer 11 and a conductive chimney rubber 12, and the conductive rubber sheet 4 extends from the bead portion 3 to the sidewall portion 2 and does not contact the belt layer 11.

[0005] The existing technology has the following deficiencies: the conductive rubber sheet 4 of the existing tire does not directly contact the belt layer 11, but indirectly contacts the belt layer 11 through the conductive rubber between the conductive rubber sheet 4 and the belt layer 11 to transmit static electricity; and the resistance value of the conductive rubber is greater than the resistance value of the conductive rubber sheet 4, thereby reducing the conductivity of the tire. At the same time, the resistance value of the chimney rubber is A, the resistance value of the belt layer is B, and the resistance value of the conductive rubber is C, and the three do not meet It is not conducive to the formation of a conductive path in the tire and increases the resistance value of the entire tire. Summary of the invention

[0006] The object of the present invention is: to solve the above problems, to transfer static electricity by directly contacting the conductive film with the belt layer, so as to improve the electrical conductivity of the tire; at the same time, the resistance value A of the chimney rubber, the resistance value B of the belt layer, and the resistance value C of the conductive film satisfy a conductive pneumatic tire which is beneficial to form a conductive path for the tire and reduce the resistance value of the whole tire.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A conductive pneumatic tire, which includes a tread portion, a sidewall portion, a bead portion and a conductive film; a bead conductive rubber is provided on the bead portion, and when the tire is installed on the rim, the bead conductive rubber contacts the rim; a conductive belt layer, a conductive chimney rubber and a tread conductive rubber are provided on the tread portion, both ends of the conductive film are respectively connected to the bead conductive rubber and one end of the belt layer, and the other end of the belt layer is connected to one end of the chimney rubber through the tread conductive rubber; the radially outer surface of the tread portion is used to contact the ground, and the other end of the chimney rubber passes through the tread portion and exposes the radially outer surface of the tread portion; the resistance value of the chimney rubber is A, the resistance value of the belt layer is B, and the resistance value of the conductive film is C, and the three satisfy

[0009] Preferably, the width of the conductive film is 60-200 mm, and the thickness of the conductive film is 0.6-1 mm.

[0010] Preferably, the tire further includes a carcass ply; the conductive film is adhered to the outside of the carcass ply, and the conductive film is axially inside the sidewall portion.

[0011] Preferably, the conductive film includes a base rubber and carbon black, wherein the BET specific surface area of the carbon black is more than 78 m2 / g.

[0012] Preferably, the base rubber of the conductive film is a diene rubber.

[0013] Preferably, the base rubber of the conductive film is styrene-butadiene rubber, and the dosage of styrene-butadiene rubber is 0-100 PHR.

[0014] Preferably, the BET specific surface area of the carbon black in the conductive film is 78 m2 / g-143 m2 / g.

[0015] Preferably, the dosage of carbon black is 20-100 PHR.

[0016] Preferably, the conductive film is composed of styrene in 30-45% emulsion-polymerized styrene-butadiene rubber and carbon black.

[0017] Preferably, the emulsion-polymerized styrene-butadiene rubber and carbon black are prepared by a wet mixing process.

[0018] The advantages of a conductive pneumatic tire adopting the above technical solution of the present invention are as follows:

[0019] When static electricity is generated on the wheel, it is transmitted in sequence along the rim - bead conductive rubber - conductive film - belt layer - tread conductive rubber - chimney rubber - ground, forming a conductive path; thereby, it can effectively and quickly conduct the static electricity generated during the use of the tire into the ground, prevent the accumulation of static electricity and generate danger, and ensure the safety during the driving of the vehicle. In this way, the conductive film is in direct contact with the belt layer to transmit static electricity, avoiding the situation that the conductive film indirectly transmits static electricity to the belt layer through conductive rubber with a relatively large resistance value, and improving the conductive performance of the tire. At the same time, when the resistance value A of the chimney rubber, the resistance value B of the belt layer, and the resistance value C of the conductive film satisfy it is beneficial for the tire to form a conductive path and reduce the resistance value of the whole tire. Description of the Drawings

[0020] Figure 1 is a schematic structural diagram of the present invention.

[0021] Figure 2 is a schematic structural diagram of the inner ring heat dissipation channel and the outer ring heat dissipation channel.

[0022] 13 - cap ply, 31 - bead wire, 32 - inner liner, 33 - filler. Detailed Embodiments

[0023] The following is a detailed description of the specific embodiments of the present invention with reference to the drawings.

[0024] Embodiment 1

[0025] As Figure 2 shown, a conductive pneumatic tire includes a tread portion 1, a sidewall portion 2, a bead portion 3, and a conductive film 4; the bead portion 3 is provided with bead conductive rubber, and when the tire is installed on the rim, the bead conductive rubber is in contact with the rim; the tread portion 1 is provided with a conductive belt layer 11, a conductive chimney rubber 12, and tread conductive rubber, both ends of the conductive film 4 are respectively connected to the bead conductive rubber and one end of the belt layer 11, and the other end of the belt layer 11 is connected to one end of the chimney rubber 12 through the tread conductive rubber; the radially outer surface of the tread portion 1 is used to contact the ground, and the other end of the chimney rubber 12 passes through the tread portion 1 and exposes the radially outer surface of the tread portion 1; the resistance value of the chimney rubber 12 is A, the resistance value of the belt layer 11 is B, and the resistance value of the conductive film 4 is C, and the three satisfy In this method, when static electricity is generated on the wheel, it is sequentially transmitted along the rim - bead conductive rubber - conductive film 4 - belt layer 11 - tread conductive rubber - chimney rubber 12 - ground to form a conductive path; thus, it can effectively and quickly conduct the static electricity generated during the use of the tire into the ground, prevent the accumulation of static electricity and generate danger, and ensure the safety during the driving of the vehicle. In this method, the conductive film 4 is in direct contact with the belt layer 11 to transmit static electricity, avoiding the situation where the conductive film 4 indirectly transmits static electricity to the belt layer 11 through conductive rubber with a relatively large resistance value, and improving the conductive performance of the tire.

[0026] The width of the conductive film 4 is 60 - 200 mm, and the thickness of the conductive film 4 is 0.6 - 1 mm to avoid additional weight gain of the tire after adding the conductive film 4.

[0027] The tire further includes a carcass ply 5; the conductive film 4 is adhered to the outer side of the carcass ply 5, and the conductive film 4 is located axially inside the sidewall portion 2 to prevent the conductive film 4 from being worn.

[0028] The conductive film 4 includes basic rubber and carbon black, and the BET specific surface area of the carbon black is above 78 m2 / g.

[0029] The basic rubber of the conductive film 4 is a diene rubber.

[0030] The basic rubber of the conductive film 4 is styrene - butadiene rubber, and the amount of styrene - butadiene rubber used is 0 - 100 PHR.

[0031] The BET specific surface area of the carbon black in the conductive film 4 is 78 m2 / g - 143 m2 / g.

[0032] The amount of carbon black used is 20 - 100 PHR.

[0033] The conductive film 4 is composed of 30 - 45% of styrene in emulsion - polymerized styrene - butadiene rubber and carbon black. The emulsion - polymerized styrene - butadiene rubber and carbon black are prepared by a wet - mixing process, that is, the polymer emulsion and carbon black filler are fully mixed in the liquid phase to increase the dispersion of the conductive filler.

[0034] Select the conductive film 4 with a width of 120 mm and a thickness of 0.8 mm, and the conductive film 4 is extruded separately to conduct the following three groups of experiments:

[0035] Experiment 1 is conducted on tires that all adopt the structure of the present invention as shown in Figure 2 However, the conductive film 4 using the common dry - mixing process and the new wet - mixing process is respectively used for testing. Among them, the dry - mixing process is to complete the mixing of the emulsion - polymerized styrene - butadiene rubber and carbon black in a conventional internal mixer; the wet - mixing process is to complete the mixing of the emulsion - polymerized styrene - butadiene rubber emulsion and carbon black in the liquid phase; the test results of the resistance values of the conductive film 4 with different mixing processes are shown in Table 1:

[0036] Experiment 1 Dry mixing resistance value of conductive film 4 Wet mixing resistance value of conductive film 4 Tire with the structure of the present invention <![CDATA[8.48×10 8 Ω·m]]> <![CDATA[6.46×10 7 Ω·m]]>

[0037] Table 1

[0038] Experiment 2 was conducted on the conductive film 4 both made by the wet mixing process, but the resistance values were measured for the tires with the existing structure as shown in Figure 1 and the tires with the structure of the present invention as shown in Figure 2 respectively; the results are shown in Table 2:

[0039] Experiment 2 Resistance value of tire with existing structure Resistance value of tire with the structure of the present invention Different structures <![CDATA[7.01×10 9 Ω·m]]> <![CDATA[6.46×10 7 Ω·m]]>

[0040] Table 2

[0041] Experiment 3 was conducted on the conductive film 4 both obtained by mixing emulsion-polymerized styrene-butadiene rubber and semi-silica in a conventional internal mixer, but the resistance values were measured for the tires with the existing structure as shown in Figure 1 and the tires with the structure of the present invention as shown in Figure 2 respectively; the results are shown in Table 3:

[0042] Example 3 Resistance value of tire with existing structure Resistance value of tire with the structure of the present invention Different structures <![CDATA[7.01×10 9 Ω·m]]> <![CDATA[7.81×10 9 Ω·m]]>

[0043] Table 3

[0044] In Experiment 1 and Experiment 2, measured by the ACL Staticide 395 surface resistance tester: the resistance value A of the chimney rubber 12 was approximately 4.39×10 9 Ω·m, the resistance value B of the belt layer 11 was approximately 7.73×10 9 Ω·m, the resistance value C of the conductive film 4 made by the dry mixing process was approximately 5.38×10 6 Ω·m, and the resistance value C of the conductive film 4 made by the wet mixing process was approximately 6.39×10 5 Ω·m; the resistance value A of the chimney rubber 12, the resistance value B of the belt layer 11, and the resistance value C of the conductive film 4 satisfied Thus, the conductive path from the bead part 3 to the tread part 1 was ensured, and the resistance of the two groups of test tires was reduced by 10 1 -10 2 Ω·m, and the smaller the resistance, the better the conductivity. In Experiment 3, the resistance value C of the conductive film 4 obtained by mixing emulsion-polymerized styrene-butadiene rubber and semi-silica in a conventional internal mixer was approximately 8.43×10 9 Ω·m; the resistance value A of the chimney rubber 12, the resistance value B of the belt layer 11, and the resistance value C of the conductive film 4 did not satisfy and no conductive path could be formed, having no positive effect on the conductivity of the tire. That is, when the resistance value A of the chimney rubber 12, the resistance value B of the belt layer 11, and the resistance value C of the conductive film 4 satisfy When it is, it is conducive to the formation of a conductive path in the tire, reducing the resistance value of the entire tire. Moreover, compared with the existing structure tires, the appearance of the tire of the present invention has no change. After adding the conductive film 4, except for the obvious change in resistance, the tire can pass other indoor performance tests without much change.

Claims

1. A conductive pneumatic tire, characterized in that, The tire includes a tread portion (1), a sidewall portion (2), a bead portion (3), a conductive film (4), and a carcass ply (5); the bead portion (3) is provided with bead conductive rubber which contacts the rim when the tire is mounted on the rim; the tread portion (1) is provided with a conductive belt layer (11), a conductive chimney rubber (12), and tread conductive rubber, the conductive film (4) is bonded to the outer side of the carcass ply (5), and the conductive film (4) is axially inside the sidewall portion (2); both ends of the conductive film (4) are respectively connected to the bead conductive rubber and one end of the belt layer (11), and the other end of the belt layer (11) is connected to one end of the chimney rubber (12) through the tread conductive rubber; the radially outer surface of the tread portion (1) is used for contacting the ground, and the other end of the chimney rubber (12) passes through the tread portion (1) and exposes the radially outer surface of the tread portion (1); the resistance value of the chimney rubber (12) is A, the resistance value of the belt layer (11) is B, and the resistance value of the conductive film (4) is C, and the following is satisfied among the three: ； The conductive film (4) consists of styrene in 30 - 45% of emulsion polymerized styrene butadiene rubber and carbon black; the emulsion polymerized styrene butadiene rubber and carbon black are obtained by a wet mixing process, and the polymer emulsion and carbon black filler are fully mixed in the liquid phase to increase the dispersion of the conductive filler; the BET specific surface area of the carbon black is 78 m 2 / g - 143 m 2 / g; the dosage of the carbon black is 20 - 100 PHR.

2. The electrically conductive pneumatic tire according to claim 1, wherein The width of the conductive film (4) is 60 - 200 mm, and the thickness of the conductive film (4) is 0.6 - 1 mm.

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