JPS5967107A - Rubber composite material and tire using the material - Google Patents

Abstract

PURPOSE:To increase adhesion between rubber and steel cords by interwining two or more strands consisting of two interwound steel filaments to form a steel cord and embedding it in the rubber of a tire as a reinforcing member. CONSTITUTION:To construct rubber composite materials, two steel filaments (f) are interwound at a particular twisting pitch to form a strand, and two strands 2a, 2b are interwound to form a steel cord C, which is embedded in the rubber for a tire. The twisting pitch of the strands 2a, 2b are varied between each other, and the twisting pitch of the steel cord C is usually determined in the range of approximately 3 to 20mm.. Thereby, voids are completely prevented from being created within the steel cord C, improving its adhesion to the rubber.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite of a steel cord and a comb, and a tire using the composite, in particular, the steel cord has a slunt made by twisting two filaments with different twisting lipids. The present invention relates to a composite using a plurality of strands and a tire using the composite.

In general, the cords used in comb composites such as breakers of tires for passenger cars, carcass of tires for heavy vehicles, breakers, timing belts, etc. have special characteristics such as high elasticity, strength, dimensional stability, and adhesiveness. Many of these cords use steel coat, which has excellent elasticity and strength. The steel cord used for flakers or karnonos has a so-called layered structure in which 3 to 5 filaments are twisted together and several more strands are twisted together, or multiple filaments are arranged in concentric circles and twisted. Some have a so-called layered structure.

For example, in the case of the twisted structure of steel cord used in passenger car tire breakers, the 1×5 structure is the first structure.
In the figure, a 1×4 structure is shown in its cross-sectional shape in FIG. The cross-sectional shapes of these steel coats are the same in the longitudinal direction, and therefore a gap (Sl, S2) is formed in the center of the cross-section into which rubber cannot penetrate. Therefore, if moisture enters these voids (Sl, S2), the moisture will expand in the longitudinal direction of the steel cord within the void at the center of this cross section, destroying the bond between the steel cord and the comb, and causing the steel cord to Causes surface rust. Therefore, in order to solve the above two problems, a so-called oven-twisted steel cord was proposed, which widened the distance between the steel filaments to make it easier for the rubber to penetrate into the voids in the middle heat section of the cross section.

However, the steel coat of these structures inherently has a relatively large elongation, which not only inhibits τJN-stability but also causes the composite to become sorted. In this case, there is a drawback that the edge of the sheet is warped, which significantly impairs workability when forming a tire.

The present invention eliminates these drawbacks and provides a comb composite with improved adhesion to the core. The purpose of this product is to further improve durability by applying it to the carcass of Soal tires.

According to the present invention, a strand 1ζ is formed by tying together two steel filaments (with a specific twisting pitch), and a steel core 1' is produced by twisting a plurality of strands with mutually different twisting pitches. It is a rubber composite characterized by being buried in the rubber as a small shrine.

The steel cord used in the composite of the present invention, -1, will be explained with reference to the drawings. Fig. 3 shows a sectional view of a steel cord having a 2x2 structure.

Here, two steel filaments (5) are twisted together to form a strand l' (2a) (2b), and two strands (2a) and (2b) are twisted together to form a steel cord (C,). 1. By adopting such a structure, the gap (S1) (S2) in the center of the steel cord seen in Figures 1 and 2 can be completely removed, and the comb and steel cord can be separated. Since the contact area increases, the contact t4 +'l is improved by -. layer. Kotesu [・
Rant' (2a) (2b) Rihi.

It is more preferable to use a combination of different cables to further increase the contact area of the rubber to the surface of the steel cord. If it is in the range of ~20η+111 or less than 3 mrs, the strength and productivity of the cord will decrease, and if it exceeds -20 η +111, the bending fatigue resistance and cohesiveness of the cord will decrease. 'Hata 1+! ('fr 0.10~040M
Is it brass-plated or used? From the viewpoint of wire drawability and adhesion, it is copper-zinc-konolt binary alloy plating, and its composition is, for example, 55-74% copper, 13-13% zinc. It is preferable to use 42 fi 1%, cord 1.04 to 12 wt%. Also, in order to prevent friction damage between the strands, when the strands are bundled and twisted into a cord, it is preferable to use It is desirable that the twisting direction is the same as that of the strands.

Next, FIG. 4 shows a sectional view of a 3×2 structure Nostyl cord according to another embodiment of the present invention. Here ← Next thread □ Rad (4
a), (4b), and (4C) may all have different twist pitches, or only the strand of one tree may be different from the body of the other two trees =≠sI land. Note that it is preferable to set the shortest twist pitch within a range of 30% or more of the longest twist pitch in order to prevent distortion of the coat.

The same can be said of the 2×2 structure shown in FIG. 3 and the 7X (2×2) structure described later.

Further, FIG. 5 shows a sectional view of a steel cord having a 7×(2×2) structure according to another embodiment of the present invention. Core strand (5b) (5C) (5d)' (5e) (5f) (5g
(7) It is possible to adopt a configuration in which the twisting pitches are made to differ by Iff, or a configuration in which the twisting pinches of the side lands are made to differ from each other.

Next, in the present invention, a rubber composite in which the steel cords described above are embedded in a comb is applied to a tire carcass.

That is, in the 61st λ1, the pneumatic tire (1
) consists of a ply with a metal coat aligned in the radial direction of the tire, and the carcass (3) is made by wrapping both ends of this braai from the inside to the outside around the heat core (2), and the crown of this carcass. Multiple breaker layers consisting of metal cords arranged at shallow angles in the circumferential direction of the tire (
4) On the outside of this breaker layer, there is a layer of 1 and 2 (5).
A structure is shown in which a strip com (6) whose thickness is gradually reduced from the heat core (2) in the direction of the site anatomical direction is arranged in a part surrounded by the carcass and its rolled-up part (3a). has been done. Note that the left half of the cross section of the tire is symmetrical to the right half and is therefore omitted. Here the breaker layer (4)
and the carcass (2) with the widest flaker layer (4B)
A cushion rubber (7) whose thickness gradually decreases in both directions centering on the end of the carcass is interposed, and the coat' of the carcass is
A strand is made by twisting two steel filaments together at a specific twisting pitch, and the strand has a different twisting pitch at the 41st stitch.G? A steel cord made by twisting several U strands together is used. When used as a carcass cord for tires for electric vehicles, a steel cord is suitably used, which is made by bundling seven strands of different twists and twisting them in the same direction as the steel cord. The carcass cord of conventional radial tires for heavy vehicles is 1x
The filament of the carcass cord is found in the area from the boundary between the noyorda part and the sidewall part to the end of the breaker layer (= near J?). Mutual friction damage,
There was a tendency for so-called fretting to occur. The inventors conducted various investigations into the causes of this, and found that the twisted structure of the steel cord, the adhesion between the steel cord and the comb,
It has been found that the fretting is caused by stress strain at one end of the breaker. Therefore, the present invention uses a multiple twisted cord of 2×2 strands,
In particular, a steel cord of 7x (2x2) structure as shown in Fig. 5 is used for the carcass, and
), the problem was effectively solved. Koteri・7yo/com (7) is JI
Soft steel with S hardness of 45° to 66°, especially 500 to 55°
Its lower end (7a) extends from the intersection point (P+) of the tread radial direction normal Ll and the tire maximum width position (WP) to a distance Vl in the tire maximum width position (WP). The wall thickness at the edge (CB) is equal to the wall thickness at the tread edge (TE) (T
It is preferable to set the distance between E and P within 11i of 10% to 35%. On the other hand, the upper end of the left/right rubber ends near the tore soto center monk 1, or it is placed on the 1-ren 1- side of the force so that the breaker layer (4) and carcass (3) are completely separated. They may be arranged integrally. However, in the radial tire of the present invention, when an impact is transmitted from the trend surface toward the carcass, the strain in this area is dispersed and absorbed because the 7-inch hump is placed at one end of the breaker, and the carcass cord is quickly moved. The contact area between the two filaments is reduced, and the contact area with the comb is increased, so the Flex 1 ink is significantly IIL￥
Embodiments of the present invention will now be described.

A rubber 19 composite was created by embedding the various steel cords shown in Table 1 into a comb having a composition shown in Table 2, and then using this comb composite to form a rubber cord as shown in FIG. 6. A prototype tire was made using the carcass of a 1000R20 Nodrakhas River all-steel radial tire.

Twisting of steel cord] In order to understand the degree of comb penetration into the steel cord of the prototype tire, we evaluated the air permeability of the cord and the degree of rust on the cord after running in a salt water drum, and the results are the first! NinF.

The performance evaluation method is as follows.

(1) Cord air permeability Cut the steel cord ply from the belt layer or case of the trial tire and test piece with the shape shown in Figure 7.
11) Perform molding and vulcanization. In the figure, 9 is a vulcanized rubber plate;
10 is Sujiru Court Bligh. Therefore, the test Q' (n) is shown in Fig. 9.
) and υj pores 14) are placed in the measuring device (16). So when back pressure 3 K9/c and scraps are loaded,
The volume of air exiting from the exhaust hole (14) in one minute was measured. The measured value of Comparative Example 8 is set as 100, and the relative value is shown.

(2) Incidence of steel cord rust after running on a salt water drum The tread of the tire has 3 drilled holes in the radial direction from the inner surface of the tire, and 500 cc of 10% salt water was applied to the tire and tube. Intermediate 7. 7 5 Multiply the inner ring of K9/c4.

Cargo 3 6 4 5 K9, speed 50 km/h
After conducting a drum test under the following conditions and driving 30,000 km,
Dismantle the tire, cut out the belt layer or carcass ply, and calculate the average value of the length of rust generated along the steel cord IJ around the drill hole divided by the total length of each cord as the steel cord degree. .

(3) Frette ink property W1/Value method IM Remove the Carno J Scord from the tire after running on the water drum. After burning the comb on the surface of the steel cord, break the steel cord into filament 111 pieces. Firamen)
- Wipe off carbon black, etc. on the surface with a cloth. play h
The condition of thick abrasion damage of the filament in the portion corresponding to the 'f'# section is observed using a 20x stereoscopic microscope. The damage state of the filament is determined by the force that causes the worst damage (to what percentage of the filament diameter) to evaluate the fretting. The worst thing about Fure Notenku is Firameno L-17
J-resistance is occurring.

Table 2 1 Main 1) 2.24-trimethyl-1,2-chlorohequinol/Note 2) N-chlorohequinol-2-henzothiacylsulfenamide (CZ manufactured by Suminen Kagaku d)

[Brief explanation of drawings]

Figures 1 and 2 are cross sections of conventional 1x5 and ■x4 steel structures, Figure 3 is a 2x2 structure, Figure 4 is a 3x2 structure, and Figure 5 is a 7x ( 6 is a partial cross-sectional view of the tire of the present invention, and FIG. 7 is a schematic cross-sectional view of an air permeability measuring device. Patent applicant Sumitomo Com-C Gyo Co., Ltd. Agent Patent attorney Nakamura prosthetic hand c1 4b Figure 7

Claims (4)

[Claims] (1) Two steel filaments are twisted together at a specific twist pitch to form a strand, and a steel coat made by twisting multiple filaments with different twist pitches is reinforced in the tire comb. Qom complex characterized by being buried as a shrine (2) The comb composite according to claim 1, wherein the steel coat is twisted in the same direction as the strands. (3) Consists of a ply in which metal cords are aligned in the radial direction of the tire, with both ends of this ply wrapped around the heat core from the inside to the outside, and arranged at a shallow angle in the tire circumferential direction on the crown of this carcass. A layer of multiple breakers made of a metal coat coated with a metal coating, and a red layer was placed on the outside of this layer of breakers, and the thickness was gradually reduced in the direction from the heat core to the sidewall in the area surrounded by the carcass and its rolled up part. In a pneumatic tire in which a stockcom is arranged, (a) between the breaker layer and the carcass, a piece of rubber whose thickness gradually decreases in both directions centering on the edge of the breaker with the maximum width is arranged; O) a metal coat of the carcass; This pneumatic tire is characterized by using a steel coat made by twisting two pieces of steel filament together in a specific twist to form a strand, in which a plurality of strands having mutually different twist pitches are twisted together. (4) The metal cord of the carcass has an IQ of twist pitch.
Pneumatic tire according to claim 3, which is a steel coat made by bundling seven strands of strand I and twisting them in the same direction as strand I. (5) The steel cord is not wrapped. A pneumatic tire according to claim 3, characterized in that: