KR101437679B1 - Pneumatic tire - Google Patents

Abstract

The present invention relates to a pneumatic tire, wherein the pneumatic tire comprises a sealant layer formed on the inner surface, wherein the sealant layer comprises 100 parts by weight of butyl rubber, 200 to 400 parts by weight of polyisobutylene, 10 to 100 parts by weight of an inorganic additive 1 to 15 parts by weight of a vulcanization agent, and 0.01 to 10 parts by weight of foamed bead particles.
The pneumatic tire can reduce the noise inside the tire by dispersing the noise energy causing the resonance in the tire or by changing the frequency of occurrence, without concern about shear deformation occurring between the sound absorbing material and the tire.

Description

Pneumatic tire {PNEUMATIC TIRE}

The present invention relates to a pneumatic tire, and more particularly, to a pneumatic tire which disperses noise energy causing resonance in a tire or changes the frequency of occurrence thereof without concern for shear deformation occurring between the noise- The present invention relates to an air pressure tire capable of reducing internal noise of a tire.

Resonance tones inside the tires are noise generated inside the tires. Recently, interest in the noise has been increasing in the car and tire companies. Such noise is caused by a change in the pressure inside the tire due to the irregular road surface shape when the tire is infused with air, and is transmitted through the vehicle path and occurs as a sound having a sharp peak in the car interior Giving the driver a sense of discomfort and reducing the ride quality. As the standard of the tire mounted on a vehicle is peaceful and inches up, the resonance noise of such a tire has become a major problem.

Various conventional noise reducing tires have been proposed in order to reduce the resonance noise inside the tire. Specifically, Korean Patent Laid-Open Publication No. 2006-125502 (Patent Document 1) discloses a method of mounting a special sponge having a sound absorbing performance on the inner surface of a tire, and Korean Patent Publication No. 2005-102110 (Patent Document 2) Discloses a technology for providing an annular body in the inside of a tire or a rim of a wheel to deform the internal space or attaching a fur or the like to the wheel surface to reduce noise caused by resonance inside the tire.

In another method, Japanese Patent Application Laid-Open No. 2002-240507 (Patent Document 3) discloses a technique for reducing tire resonance noises by incorporating a spherical sound absorbing material of 40 to 100 mm in a tire without being fixed. The above method is useful for the standard of a tire for a passenger car and does not require adhesion to prevent heat generation. However, when the tire rotates while it is not fixed to the inside of the tire, a spherical body shape deformation or an unbalance problem may occur.

In addition, Korean Patent Laid-Open Publication No. 2009-18418 (Patent Document 4) discloses a method of reducing tire noise by attaching a sound absorbing material having a size of 1/4 or 1/8 of the circumferential length of the tire to the inner surface of the inner liner of the tire have. In this case, it is troublesome to attach the sound absorbing material more than twice.

Korean Patent Publication No. 2006-125502 (published on December 6, 2006). Korean Patent Publication No. 2005-102110 (published on October 25, 2005). Japanese Patent Laid-Open No. 2002-240507 (published on Aug. 28, 2002). Korean Patent Publication No. 2009-18418 (published on February 20, 2009).

It is an object of the present invention to provide a tire capable of reducing noise inside the tire by dispersing noise energy which is a cause of resonance in the tire or changing the frequency of occurrence of the noise in the tire without concern about shear deformation occurring between the noise- To provide an air-pressure tire.

In order to achieve the above object, the pneumatic tire according to an embodiment of the present invention includes a sealant layer formed on the inner surface, wherein the sealant layer comprises 100 parts by weight of butyl rubber, 200 to 400 parts by weight of polyisobutylene, 10 to 100 parts by weight, 1 to 15 parts by weight of a vulcanization agent, and 0.01 to 10 parts by weight of foamed bead particles.

The polyisobutylene may have a weight average molecular weight of 1000 to 3000 g / mol.

The inorganic additive may be selected from the group consisting of carbon black, silica, calcium carbonate, calcium silicate, magnesium oxide, aluminum oxide, barium sulfate, talc, mica, and mixtures thereof.

The sealant layer may have a thickness of 1 to 5 mm.

The foamed bead particles may be expanded polystyrene particles.

The average particle diameter of the foamed bead particles may be 0.1 to 3 mm.

Other details of the embodiments of the present invention are included in the following detailed description.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can readily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments and drawings described herein.

Normally, when a noise absorbing material for noise reduction is mounted inside a tire, it is bonded and fixed using a peroxide type adhesive or a volatile adhesive. However, the peroxide-based adhesives or volatile adhesives are often detached easily due to bending of the adhesive portions or generated heat generated when the tire is running.

In view of this, the inventors of the present invention have found that in a pneumatic tire composed of a tread portion, a side wall portion, a bead portion and an inner liner or the like, foamed bead particles are contained in a sealant having a very high adhesion to the inner liner inner surface of the tire, The noise generated by the vibration can be effectively reduced, and at the same time, the noise absorbing material for noise reduction and the shear deformation generated in the middle of the tire can be buffered.

1 is a side sectional view of a pneumatic tire according to an embodiment of the present invention. Referring to Fig. 1, the pneumatic tire 1 according to the present invention includes a sealant layer 2 formed on the inner surface of the tire 1. As shown in Fig.

The sealant layer 2 includes foamed bead particles (not shown) for reducing resonance noise generated in the tire interior space.

The foamed bead particles may be a conventional porous member used as a sound absorbing material. Specifically, any one selected from the group consisting of sponge, foamed polyester particles, expanded polystyrene particles and mixtures thereof can be used, and polystyrene particles can be preferably used.

The foamed bead particles have an average particle diameter of 0.1 to 3 mm. If the average particle diameter of the foamed bead particles is less than 0.1 mm, the dispersion performance of the beads and the sound absorption performance may be deteriorated. If the average particle diameter of the foamed beads is more than 3 mm, there may be a problem of sealing due to disturbance of flow to the hole during tire puncture.

The sealant layer (2) may contain 0.01 to 10 parts by weight, preferably 0.01 to 1 part by weight, of the foamed bead particles with respect to 100 parts by weight of the butyl rubber. If the content of the foamed bead particles exceeds 10 parts by weight, the adhesive force of the sealant may be significantly lowered. If the content of the foamed beads is less than 0.01 parts by weight, the vibration and sound absorbing ability of the tire may be greatly deteriorated.

The sealant layer (2) includes butyl rubber, polyisobutylene, an inorganic additive and a vulcanizing agent in addition to the foamed bead particles, and may further include other additives. The sealant layer 2 having the above components is a material designed to self-seal holes formed by nails or protrusions of 5 mm or less, and has strong adhesion and temperature stability so that it can be sufficiently rested when traveling on a tire.

In order to achieve the above effect, the polyisobutylene preferably has a weight average molecular weight of 1000 to 3000 g / mol.

The polyisobutylene may be contained in an amount of 200 to 400 parts by weight based on 100 parts by weight of the butyl rubber. If the content of the polyisobutylene is less than 200 parts by weight, there is a fear that the temperature stability is lowered. If the content is more than 400 parts by weight, adhesion and buffering effect of the sealant may be deteriorated. Specifically, in order to improve adhesion and buffering effect of the sealant layer (2), the polyisobutylene is preferably used in an amount of 300 to 400 parts by weight based on 100 parts by weight of the butyl rubber. In order to improve the temperature stability, Butylene is preferably used in an amount of 200 to 300 parts by weight.

The inorganic additive is selected from the group consisting of carbon black, silica, calcium carbonate, calcium silicate, magnesium oxide, aluminum oxide, barium sulfate, talc, mica, and mixtures thereof for controlling the amount of heat generated by the sealant layer Can be used. The inorganic additive may be included in an amount of 10 to 100 parts by weight, preferably 30 to 50 parts by weight, based on 100 parts by weight of the butyl rubber.

The vulcanizing agent helps crosslink the sealant layer (2) and may be included in an amount of 1 to 15 parts by weight, preferably 5 to 10 parts by weight, based on 100 parts by weight of the butyl rubber.

As the vulcanizing agent, metal oxides such as sulfur vulcanizing agents, organic peroxides, resin vulcanizing agents, and magnesium oxide can be used. The sulfur vulcanizing agent may be an inorganic vulcanizing agent such as powdered sulfur (S), insoluble sulfur (S), precipitated sulfur (S), or colloid sulfur.

If the content of the butyl rubber, the polyisobutylene, the inorganic additive and the vulcanizing agent is out of the above range, the adhesion to the tire may be deteriorated or the sealant layer 2 may flow during running of the tire.

The sealant layer (2) may further comprise other additives selected from the group consisting of a crosslinking accelerator, a vulcanization accelerator aid, an adhesive, and a mixture thereof.

Examples of the crosslinking accelerator for accelerating the crosslinking include sulfenamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamate, aldehyde-amine, aldehyde-ammonia, imidazoline, And a combination of these. The crosslinking accelerator may be included in an amount of 0 to 10 parts by weight, preferably 3 to 5 parts by weight, based on 100 parts by weight of the butyl rubber.

The above-mentioned vulcanization accelerating assistant may be used together with zinc oxide and stearic acid as a compounding agent which is used in combination with the vulcanization accelerator to complete its promoting effect. When the zinc oxide and the stearic acid are used together, they may be used in an amount of 1 to 5 parts by weight and 0.5 to 3 parts by weight, respectively, based on 100 parts by weight of the butyl rubber in order to serve as a proper vulcanization accelerator.

Examples of adhesives for improving the adhesive strength of the sealant include natural resin such as phenol resin, rosin resin or terpene resin and synthetic resin such as petroleum resin, coal tar or alkylphenolic resin Can be used. In this case, the adhesive may be included in an amount of 0 to 10 parts by weight, preferably 3 to 5 parts by weight, based on 100 parts by weight of the butyl rubber.

Since the sealant layer 2 having the above composition is formed by crosslinking with the composition based on the butyl rubber, the viscosity change does not occur largely even at a high temperature, and the sealant layer 2, due to the centrifugal force generated upon rotation of the tire, Or spread does not occur. In addition, it has strong adhesion and temperature stability so that it can be held sufficiently when driving a tire.

The sealant layer 2 as described above has a thickness of 1 to 5 mm and is excellent in adhesion properties and buffering action against shear deformation of the tire and can self-seal against punctures generated by nails or protrusions of 5 mm or less have.

The width of the sealant layer 2 is preferably 100 to 120% of the width of the tire tread portion.

The pneumatic tire according to the present invention having the above-described structure can be produced by applying the composition for forming a sealant layer on the inside of a tire and then crosslinking the sealant.

The kind and content of the butyl rubber, polyisobutylene, inorganic additive, vulcanizing agent and foamed bead constituting the composition for forming the sealant layer are as described above, and may further contain other additives as required. The kind and content of the other additives are as described above.

Specifically, the composition for forming a sealant layer is prepared by mixing the butyl rubber, polyisobutylene, an inorganic additive, a vulcanizing agent, a foamed bead particle and optionally other additives, and then the thickness of the sealant layer finally formed on one side of the porous sound- Is 1 to 5 mm, and the sealant crosslinking reaction is carried out at a high temperature of 140 to 180 ° C to prepare the sealant layer (2).

The pneumatic tire according to the present invention can be a tire for a passenger car, a race tire, an airplane tire, an agricultural machine tire, an off-the-road tire, a truck tire or a bus tire, . Further, the tire may be a radial tire or a bias tire, and preferably a radial tire.

INDUSTRIAL APPLICABILITY The pneumatic tire of the present invention can effectively reduce noise generated by resonance and vibration in a tire for a vehicle and does not significantly change the viscosity of the sealant layer even at a high temperature and prevents the sealant from deviating due to centrifugal force The sealant layer has strong adhesion and temperature stability so that it can be sufficiently rested when the tire is running.

1 is a side sectional view of a pneumatic tire according to an embodiment of the present invention.
FIG. 2 is a graph showing the results of observation of resonance noise preventing effects of tires manufactured in Examples and Comparative Examples of the present invention. FIG.

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.

[ Manufacturing example : noise Reduction  Manufacture of Sound Absorbing Member]

( Example  One)

The composition for forming a sealant layer was prepared by mixing the components as shown in the following Table 1, and then applied to the inside of the inner liner of a tire (spec. 235 / 45R17) and subjected to a crosslinking reaction at a high temperature of 170 캜, A sealant layer was formed to produce a tire.

( Comparative Example  One)

A tire was prepared in the same manner as in Example 1 except that the composition for forming a sealant layer in Example 1 did not contain foamed bead particles.

( Comparative Example  2)

A tire was produced in the same manner as in Example 1 except that the sealant layer was not formed in Example 1.

Raw material Content (parts by weight) Butyl rubber 100 Polyisobutylene (Mw = 2300) 300 Carbon black (N330) 40 ZnO 5 Stearic acid One sulfur 5 accelerant
(Zinc dibenzyldithiocarbamate, ZBEC) 2 Foamed bead particles (expanded polystyrene, average particle diameter 1.5 to 2.0 mm) 0.2

[ Experimental Example : Noise of tire Abatement  Performance evaluation]

The tires prepared in the above Examples and Comparative Examples were mounted on a regular rim, and the presence of noise reduction and adhesion state of the sealant layer were judged by the test equipment of normal air pressure condition. The results of the noise analysis were as shown in the graph of FIG. 2, and it was confirmed that the noise reduction effect of about 2 to 3 dB was observed in the running, and the adhesion state of the sealant layer was also good after the running was completed.

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.

1: Tire
2: sealant layer

Claims (6)

And a sealant layer formed on the inner surface,
Wherein the sealant layer comprises 100 parts by weight of butyl rubber, 200 to 400 parts by weight of polyisobutylene, 10 to 100 parts by weight of an inorganic additive, 1 to 15 parts by weight of a vulcanization agent, and 0.01 to 1 part by weight of foamed bead particles. The method according to claim 1,
Wherein the polyisobutylene has a weight average molecular weight of 1000 to 3000 g / mol. The method according to claim 1,
Wherein the inorganic additive is selected from the group consisting of carbon black, silica, calcium carbonate, calcium silicate, magnesium oxide, aluminum oxide, barium sulfate, talc, mica, and mixtures thereof. The method according to claim 1,
Wherein the sealant layer has a thickness of 1 to 5 mm. The method according to claim 1,
Wherein the foamed bead particles are expanded polystyrene particles. 6. The method of claim 5,
Wherein the foamed bead particles have an average particle diameter of 0.1 to 3 mm.

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