WO2000078562A1

WO2000078562A1 - Low-noise tire

Info

Publication number: WO2000078562A1
Application number: PCT/JP1999/003308
Authority: WO
Inventors: Yasuyuki Ohira; Mitsuo Hori
Original assignee: Shishiai-Kabushikigaisha
Priority date: 1999-06-21
Filing date: 1999-06-21
Publication date: 2000-12-28

Abstract

A low-noise tire for automobiles, having an excellent damping performance, characterized in that a base resin contains a damping material comprising an active component adapted to increase a dipole moment in the base resin.

Description

Akitoda, Quiet tire Technical field

TECHNICAL FIELD The present invention relates to a silent tire for an automobile in which noise during running is reduced. Background art

Generally, as shown in Fig. 8, an automobile tire 1 has a tread portion 2 on an outer surface that comes into contact with a road surface, a force portion 9 on an inner surface side of the tread portion 2, a breaker belt portion 3, and a radial ply 4. Or an inner layer made of a bias ply or the like. The tread portion 2 is formed in an annular shape having a substantially U-shaped cross section, and a rib portion 6 including a beat wire 5 is formed at both ends thereof so that the rib portion 6 is fitted into the rim flange 8 of the wheel 7. It has become. Such tires are required to have various performances such as abrasion resistance, wet braking performance, and rolling resistance.However, when a vehicle is running, it is caused by vibration or air bombing that occurs when the tire tread surface comes into contact with the road surface. There is a problem that noise is generated inside and outside the vehicle. Conventionally, various proposals have been made for the purpose of preventing such a problem, that is, noise during traveling. For example, Japanese Patent Application Laid-Open No. 1-254411 discloses that by providing a layer of a foamed rubber composition having a foaming rate of 150% or more inside a tire, the tire characteristics are not impaired, and the tire is manufactured with a low performance. Proposals have been made to reduce noise. However, even such an attempt did not achieve the noise reduction effect enough to sufficiently solve the above problem, and an effective solution was required. An object of the present invention is to provide a silent vehicle tire having reduced noise during traveling. It is the purpose. Disclosure of the invention

The silent tire according to the present invention is characterized by including a damping material in which an active component that increases the amount of dipole moment in the base resin is mixed with the base resin. In the silent tire according to the present invention, the damping material contained in the tire reliably attenuates noises that enter and exit the vehicle due to vibration or air bombing generated when the tire tread surface contacts the road surface. It is like that. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view showing one embodiment of the silent tire of the present invention.

FIG. 2 is an enlarged sectional view showing another embodiment of the silent tire of the present invention.

FIG. 3 is a schematic diagram showing a dipole in the base resin.

Fig. 4 is a schematic diagram showing the state of the dipole in the base resin when vibration energy is applied.

FIG. 5 is a schematic diagram showing a state of a dipole in a base resin when an active ingredient is blended.

FIG. 6 is a schematic diagram showing a test device for measuring a noise level during running of the tires of the example and the comparative example.

FIG. 7 is a graph showing the noise level (d B A) during running for the tires of the example and the comparative example at each frequency.

FIG. 8 is a perspective view showing the structure of a conventional general tire. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the silent tire of the present invention will be described in more detail. This silent tire is for an automobile, and includes a base resin and a vibration damping material in which an active component that increases the amount of dipole moment in the base resin is blended. Applied to this damping material Base resins include polyvinyl chloride (PVC), polyethylene (PE), chlorinated polyethylene (CPE), polypropylene (PP), ethylene-vinyl acetate copolymer, polymethyl acrylate (PMMA), polyvinylidene fluoride, Polymers such as polyisoprene (IP), polystyrene (PS), styrene-butadiene-acrylonitrile copolymer (ABS), styrene-acrylonitrile copolymer (AS), polycarbonate, or natural rubber (NR), styrene Halogenated rubbers such as butadiene rubber (SBR), butadiene rubber (BR), butyl rubber, isobutylene isoprene rubber (IIR), chlorinated butyl rubber, and brominated butyl rubber, and ethylene.propylene-gen-based copolymer rubber (EPDM) , Acrylonitrile-butadiene rubber (NBR), isoprene rubber (IR), etc. One selected from the above rubber-based polymers or a mixture thereof can be used. The present inventor has clarified the mechanism of absorption and attenuation of new vibration energy through research on vibration damping materials. The mechanism is as follows. That is, FIG. 3 shows an arrangement state of the dipole 32 inside the base resin 31 before the vibration energy is transmitted. It can be said that the arrangement state of the dipole 32 is in a stable state. However, when vibration energy is transmitted to this, displacement occurs in the dipoles 32 existing inside the base resin 31, and as shown in FIG. Will be placed in an unstable state, and each dipole 32 will try to return to a stable state as shown in FIG. At this time, energy is consumed. It is considered that vibration energy is absorbed through the displacement of the dipole inside the base resin 31 and the energy consumption by the restoring action of the dipole. From the mechanism of such vibration damping, as the amount of the dipole moment inside the base resin 31 as shown in FIGS. 3 and 4 increases, the damping property of the base resin 31 increases. It is considered to be. For this reason, it is difficult to use a resin having a large dipole moment inside the molecule as the base resin. This is very useful in ensuring high vibration energy absorption performance (damping performance). When selecting the base resin, it may be appropriately determined according to the application site of the tire, for example, a tread portion, a belt portion, a radial ply or a bias ply, that is, in consideration of the performance required for the application site. It is desirable to consider the magnitude of the dipole moment inside the molecule. It is also good to consider the size and shape of the application area, as well as the handleability, moldability, availability, temperature performance (heat resistance and cold resistance), weather resistance, and price of the base resin. The active component is a component that dramatically increases the amount of dipole moment in the base resin, and the active component itself has a large dipole moment, or the active component itself has a small dipole moment. It refers to a component that can dramatically increase the amount of dipole moment in the base resin by combining the active component. For example, the amount of the dipole moment generated in the base resin 31 under a predetermined temperature condition and the magnitude of the energy can be adjusted by blending the active ingredient into the base resin 31 as shown in FIG. It will increase by a factor of 3 or 10 below. Along with this, it is considered that the energy consumption due to the restoring action of the dipole 32 when the above-mentioned energy is added also increases drastically, and vibration damping performance far exceeding the prediction is produced. Examples of active ingredients that induce such effects include N, N-dicyclohexylbenzothiazyl-2-sulfenamide (DCHBSA), 2-mercaptobenzothiazole (MBT), dibenzothiazylsulfide (MBTS), Cyclohexyl benzothiaziru 2-sulfenamide (CBS), N-tert

-2-sulfenamide (BBS), N-oxyxeti

—Sulfenamide (〇BS), N, N—diisopropyl A compound containing a benzothiazyl group, such as benzothiazyl 2-sulfenamide (DPBS), and a benzotriazole with an azole group bonded to the benzene ring as the mother nucleus, to which a phenyl group is bonded. —Hide mouth 3 '― (3 ", 4", 5 ", 6" tetrahydroflophthalimide methyl) 1 5' —Methylphenyl} Benzotriazole (2HPMMB), 2-{2 ' 1-Hydrox—5′—Methylphenyl} —Benzotriazole (2HMPB), 2- {2′Hydroxy—3′-t-butyl-1-5′—Methylphenyl} 1—5-Hydroxy Benzotriazole groups such as benzotriazole (2HBMP CB), 2- {2'-hydroxy-3 ', 5'-di-t-butylphenyl} -5-chlorobenzototriazole (2HDBPCB) A compound having the following: ethyl 2-cyano-3,3-diphenylacrylate Which compounds contain diphenyl acrylate groups, or 2-hydroxy-4-methoxybenzophenone (HMBP), 2-hydroxy-4-methoxybenzophenone- 15-sulfonic acid (HMBPS) And one or more compounds selected from compounds having a benzophenone group. Incidentally, the amount of dipole moment in the above-mentioned active ingredient is variously different depending on the type of the active ingredient, similarly to the amount of dipole moment in the base resin. Even when the same active component is used, the amount of dipole moment generated in the base resin changes depending on the temperature when vibration energy is applied. The amount of dipole moment also changes depending on the magnitude of the vibration energy applied to the base resin. For this reason, it is desirable to select and use the active component that gives the largest amount of the dipole moment in consideration of the temperature and energy at the time of application. In deciding the active ingredient to be blended in the base resin, it is good to select the one with a similar value in consideration of the compatibility between the active ingredient and the base resin, that is, the SP value. It is desirable that the compounding amount is 10 to 400 parts by weight based on 100 parts by weight of the base resin. That is, if the amount of the active ingredient is less than 10 parts by weight, the sufficient effect of dramatically increasing the amount of the dipole moment in the base resin cannot be obtained. If the amount is more than 0 parts by weight, an increase in the amount of dipole moment cannot be expected by the increased amount even if the amount is increased, and furthermore, there is a risk of causing a disadvantage that the formability is deteriorated. When two or more of the above active ingredients are blended, at least two or more active ingredients having different glass transition points can be blended into the base resin to extend the temperature range in which vibration absorption performance is exhibited. It is. For example, a combination of DCHBSA and 2 HP MMB when BR is used as a base resin, and a combination of DCHBSA, 2 HP MMB and ECDPA when SBR is used as a base resin can be given. In addition, the above-mentioned vibration damping material is filled with an inorganic filler such as my flakes, glass pieces, glass fiber, carbon fiber, calcium carbonate, barite, precipitated barium sulfate, etc. for the purpose of further improving the vibration damping performance. You can also. The inorganic filler is preferably contained in a proportion of 100 to 100 parts by weight based on 100 parts by weight of the base resin. For example, when the filling amount of the inorganic filler is less than 10 parts by weight, even if the filling of the inorganic filler is performed, the vibration damping performance is not sufficiently improved. Even if the amount exceeds 100 parts by weight, adverse effects may occur if filling cannot be actually performed or mechanical strength decreases. In addition to the above components, anti-oxidants, reinforcing agents and reinforcement Agents, antistatic agents, flame retardants, lubricants, foaming agents, coloring agents, and the like. The silent tire of the present invention contains the above-described vibration damping material. As a preferred mode, as shown in FIG. 1, the tread portion 12 constituting the tire 11 and the inner surface thereof In this case, the component itself of the tire 11 such as the carcass part 19, the breaker belt part 13, and the radial ply 14 may be formed of the damping material. For example, the tread portion 12 is a rubber layer composed of a mixture of SBR and BR or a mixture of NR and BR mixed with carbon black depending on the type of tire, and the active ingredient is compounded in these rubber materials. This gives the tread portion 12 itself vibration damping properties. In this case, depending on the amount of the active ingredient, the tire performance such as abrasion resistance, wet damping property and rolling resistance may be impaired. In the embodiment shown in FIG. 1, the tread portion 12 has a two-layer structure of a cap tread 12a and an inner tread 12b, and the inner tread 12b at the inner side is made of the above-described vibration damping material. The carcass portion 19 is formed by laminating a plurality of layers each having a rubber layer on the upper surface of a bamboo cloth, and the carcass portion 19 itself is compounded by mixing an active ingredient into the rubber material constituting the rubber layer. It gives vibration damping properties to In this case, depending on the amount of the active ingredient, sufficient care must be taken because the strength may be reduced and the function of withstanding the load, impact and air pressure received by the tire may be impaired. The breaker belt portion 13 is disposed between the tread portion 12 and the carcass portion 19 to mitigate an external impact, and cracks and scratches generated in the tread portion 12 are directly applied to the carcass portion 19. It is a part that has the function of preventing the influence, but this belt part 13 also has a rubber layer on the upper surface of It is a combination. Also in the case of the belt portion 13, the active material is blended into the rubber material constituting the rubber layer to impart vibration damping properties to the belt portion 13 itself. The three examples in which the tire component itself is made of the damping material have been described above. However, the present invention is not limited to this, and the tire can be freely changed, for example, a plurality of tire components are made of the damping material. Also, instead of constituting the component itself of the tire 11 with the damping material, for example, as shown in FIG. 2, the damping material is formed into a sheet, and the damping sheet 20 is attached to the tread portion 1. For example, it can be applied to the tire as a part separate from the constituent parts of the tire 11 by bonding to the inner surface side of the tire 2. In the case of the embodiment shown in FIG. 2, since it is only necessary to bond the vibration damping sheet to the inner surface of the tread portion 12, there is the simplicity that a commercially available tire can be used as it is. Example

95.0 parts by weight of CPE (Eraslen 352 NA manufactured by Showa Denko KK), 65.0% by weight of My power scales (Kuraray My Power, 30C, manufactured by Kuraray Co., Ltd.) and 26.0% by weight of DC HB SA This mixture was put into a kneading roll set at 160 ° C and kneaded, and the obtained kneaded product was sandwiched between molds heated to 180 ° C and heated for 180 seconds. The sheet was pressed with a press machine at a pressure of 80 kg · f / cm ² for 30 seconds to obtain a vibration-damping sheet having a thickness of lmm. As shown in FIGS. 2 and 6, the vibration damping sheet 20 was adhered to the inner surface of the tread portion 12 with an adhesive. The tire 11 is rotatably supported by the support 23, and the tire 11 is placed on a rotating roller 21 provided with irregularities on its surface, and the rotating roller is rotated to rotate the tire 11 and The noise level (dBA) was picked up by a sound level meter. The results are shown in FIG. The noise was measured at a temperature of 25 ° C and a tire rotation speed of 20 rpm. For comparison, a similar experiment was carried out for a tire without a vibration damping sheet (comparative example), The sound level was measured and also shown in Figure 7.

Claims

Scope of word blue

1. A silent tire characterized by including a base resin containing a vibration damping material containing an active component that increases the amount of dipole moment in the base resin.

2. The silent tire according to claim 1, wherein the component parts of the tire are made of a vibration damping material obtained by mixing an active ingredient with a base resin.

3. The silent tire according to claim 1, wherein a vibration damping material obtained by mixing an active ingredient with a base resin is formed in a sheet shape, and the sheet is disposed on an inner surface side of the tire.

4. Base resin is polyvinyl chloride (PVC), polyethylene (PE), chlorinated polyethylene (CPE), polypropylene (PP), ethylene-vinyl acetate copolymer, polymethyl methacrylate (PMMA), and poly (vinylidene fluoride) , Polyisoprene (IP), polystyrene (PS), styrene-butadiene-acrylonitrile copolymer (ABS), styrene-acrylonitrile copolymer (AS), polymer such as polyacrylonitrile, or natural rubber (NR) , Styrene-butadiene rubber

(SBR), butadiene rubber (BR), butyl rubber, isobutylene isoprene rubber (IIR), chlorinated butyl rubber, halogenated rubber such as brominated butyl rubber, etc., ethylene / propylene / copolymer rubber (EPDM), acrylonitrile — The silent sound according to any one of claims 1 to 3, wherein the rubber is one selected from rubber-based polymers such as butadiene rubber (NBR) and isoprene rubber (IR) or a mixture thereof. tire.

5. The silent tire according to any one of claims 1 to 3, wherein the active ingredient is one kind or two or more kinds selected from compounds containing a benzothiazyl group.

6. The silent tire according to any one of claims 1 to 3, wherein the active ingredient is at least one compound selected from compounds having a benzotriazole group.

7. The silent tire according to any one of claims 1 to 3, wherein the active ingredient is at least one compound selected from compounds having a diphenyl atalylate group.

8. The silent tire according to any one of claims 1 to 3, wherein the active ingredient is one kind or two or more kinds selected from compounds having a benzophenone group.

9. The silent tire according to any one of claims 1 to 3, wherein the active ingredient is contained in an amount of 10 to 400 parts by weight based on 100 parts by weight of the base resin.