JPS6347642B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to improvements in solid rubber tires made by vulcanizing and adhering tread rubber to a baseband or wheel. Conventionally, this type of tire is constructed by integrating a tread rubber (a) onto the outer peripheral surface of a steel baseband (b) or wheel (c) by vulcanization adhesive, as shown in FIG. 1 or 2. In addition, this type of tire is required to have various characteristics such as wear resistance, cut resistance, chipping resistance, and low rolling resistance, but in order to improve these characteristics, adjusting the rubber compound of the tread can improve Generally, such treaded rubber reduces the adhesive force to the baseband b, etc. In other words, in order to improve the above properties, methods such as increasing the amount of filler such as carbon or adding organic or inorganic short fibers for reinforcement can be considered, but these methods reduce the fluidity of the tread rubber. This results in a loss of adhesive strength, and as a result, the adhesive does not adhere uniformly to the rough surface of the baseband, leaving an air layer at the interface between the two. In particular, in the manufacturing process of this type of tire, vulcanization is press vulcanized with a pressing force in a direction parallel to the interface between the tread rubber and the baseband.
The pressing force of the tread rubber against the base band is not sufficient, and therefore, combined with the low fluidity of the tread rubber, the adhesive force at the interface is low. The present invention solves such problems by improving properties such as abrasion resistance, cut resistance, and chipping resistance, as well as improving the adhesion between the tread rubber and the baseband or wheel, thereby extending the durability life. The purpose of the present invention is to provide a rubber solid tire that can further improve performance. As shown in FIG. 3, the present invention provides a solid rubber tire in which a tread rubber 3 is vulcanized and bonded to a baseband 2 or a wheel via a cushion rubber 4, in which the cushion rubber 4 has (a) a Mooney viscosity (ML ₁₊₄ ); , 130℃) is lower than that of treaded rubber 3 and its value is in the range of ₃₀ to 50; It is a solid rubber tire characterized by a range of up to 30 minutes. First, the rubber solid tire 1 of the present invention is composed of a baseband 2 and a tread rubber 3, and a cushion rubber 4 is further arranged in an intermediate layer between the two. Here, the cushion rubber 4 becomes fluidized by the temperature increase during the vulcanization process, easily penetrates into the microscopic unevenness voids of the baseband 2, and increases the adhesive interface, so that its Mooney viscosity (ML ₁₊₄ , 130 ℃) is 30~
Set to a range of 50. If the Mooney viscosity exceeds 50, the fluidity will be insufficient, resulting in poor adhesion to the surface of the baseband 2, resulting in a decrease in adhesive strength.On the other hand, if the Mooney viscosity is less than 30, the physical properties of the cushion rubber 4 itself will deteriorate, resulting in agglomeration of this part. The breakage results in a decrease in the adhesive strength between the tread rubber 3 and the baseband 2. Furthermore, in order to separate the tread rubber 3, which generally has low adhesiveness, from the baseband 2 and safely cover the surface of the baseband 2 with the cushion rubber 4, the Mooney viscosity of the cushion rubber 4 must be smaller than that of the tread rubber 3. Next, the vulcanization speed of the cushion rubber 4 has an important effect on the adhesiveness with the baseband 2. In other words, the tread rubber 3, cushion rubber 4, and baseband 2 are bonded together at the same time as vulcanization, but in order to strengthen the adhesion between the baseband 2 and cushion rubber 4, the cushion rubber 4 is first fluidized at the vulcanization temperature. It is necessary for the tread rubber 3 to fit well with the irregularities of the baseband 2, and then to be fluidized and to press the cushion rubber 4 to the baseband 2 with its expansion pressure. Therefore, it is necessary that the scorch time (t ₁₀ , 130° C.) of the cushion rubber 4 is slower than that of the tread rubber 3, and the scorch time is in the range of 8 to 30 minutes. If the scorch time is less than 8 minutes, rubber processing,
On the other hand, if it is slower than 30 minutes, it will impair storage stability.
It takes an extremely long time to cure and is not economical. The rubber composition of the cushion rubber 4 that satisfies the above conditions is one of natural rubber, synthetic polyisoprene rubber, styrene-butadiene rubber, butyl rubber, and butadiene rubber, or a mixture thereof, carbon,
Oil, vulcanizing agent, vulcanization aid, and vulcanization accelerator can be mixed and used, but in particular, by adding thermosetting resin such as phenol resin, xylene resin, melamine resin, etc. It is possible to improve the adhesion with 2. The cushion rubber 4 is usually used in the form of a sheet having a thickness of 1 to 6 mm. The tread rubber 3 used in the present invention has an increased amount of carbon and can be filled with short fibers in order to improve wear resistance, chipping resistance, and cut resistance, and the base band 2 is usually made of steel. It is also possible to use one made of aluminum with an adhesive applied to the surface, or to connect it directly to the wheel instead of the baseband. As mentioned above, in the rubber solid tire of the present invention, the cushion rubber is arranged and its Mooney viscosity and scorch time are set within a specific range in relation to the tread rubber, so that the tire flows well to the baseband surface. Moreover, the bond between the baseband or wheel and the tread rubber can be further strengthened. Example 1 The surface of an iron plate with a width of 25 mm, a length of 165 mm, and a thickness of 4 mm was sandblasted, washed with toluene, and an adhesive (Chemlock) was applied on top of the sandblast, and the product was prepared as Cushion Rubber 4 as shown in Table 1. Unvulcanized sheets (thickness: 4 mm) having the compositions A to C were laminated, and the tread rubber 3 having the composition C in the table was further laminated thereon and bonded by vulcanization. Table 2 shows the measurement results of the adhesive force between the iron plate surface and the cushion rubber 4 for various combinations, and FIG. 4 shows the relationship between the adhesive force and the adhesive surface pressure. Further, FIG. 5 shows the results of measuring the effect on adhesive force by varying the Mooney viscosity of the cushion rubber 4. In this case, the amount of vulcanization was 30 ECU, and the surface pressure during vulcanization was 3 Kgf/cm ² .

【table】

【table】

[Table] Shows the results.
From Table 2, it is recognized that the adhesive strength of the examples of the present invention is considerably improved, and from FIG. I understand.

[Brief explanation of drawings]

Figures 1 and 2 are cross-sectional views illustrating a conventional solid tire, Figure 3 is a cross-sectional view illustrating an embodiment of the solid tire of the present invention, and Figure 4 shows the adhesive strength between the example product of the present invention and the conventional product. A diagram showing a comparison, FIG. 5 is a diagram illustrating adhesive force when Mooney viscosity is changed. 2...Baseband, 3...Treaded rubber, 4
...Cushion rubber.

Claims (1)

[Scope of Claims] 1. A solid rubber tire formed by vulcanizing and adhering tread rubber to a baseband or wheel via a cushion rubber, wherein the cushion rubber is made of at least one of a phenol resin, a xylol resin, and a melamine resin. In addition, (a) the Mooney viscosity (ML ₁₊₄ , 130℃) is lower than that of treaded rubber, and the value is lower than that of Mooney.
(b) A scorch time (t ₁₀ , 130°C) is slower than that of treaded rubber, and the value is in the range of 8 to 30 minutes.