JPH07216768A - Parallel bundle wire for reinforcing rubber article and composite of the wire and rubber - Google Patents

Abstract

PURPOSE:To obtain a parallel bundle wire for the reinforcement of a rubber article having excellent oblique shear strength characteristics and obtain a composite material such as tire, conveyor belt and high-pressure hose by embedding the wire as a reinforcing material in rubber. CONSTITUTION:This parallel bundle wire can be produced by preparing thin filaments 1 having metal-plated surface, parallelly aligning 9 to 30 filaments in such a manner as to form a polygonal cross-section and winding 1 to 5 metal filaments 2 on the outer circumference of the thin filament bundle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a parallel bundle wire for reinforcing a rubber article having excellent diagonal shear strength properties, and a tire, a conveyor belt, and a high pressure hose made by embedding this wire in rubber as a reinforcing material. Etc. regarding the complex.

[0002]

2. Description of the Related Art Reinforcing materials used to reinforce rubber articles are usually made of high carbon steel wire (JIS G 3502 piano wire) and have brass, copper or zinc on the surface to provide adhesion with rubber. It is metal-plated and wire-drawn to a diameter of 0.1 to 0.5 mm, then single-twisted, multi-twisted, or layer-twisted, widely used as a reinforcing material for automobile tires, conveyor belts, high-pressure hoses, etc. It is used.

For example, a metal cord having a 3 + 6 two-layer twist structure is used as a belt reinforcing member for a radial tire for a truck bus.

Quality characteristics required for this kind of rubber reinforcing material include adhesiveness with rubber, corrosion resistance and various other mechanical performances (diagonal shear load, cutting load, rigidity, etc.).

[0005]

Among the quality characteristics required for the rubber reinforcing material as described above, with respect to the corrosion resistance, when the rubber uncovered portion is present in the reinforcing material embedded in the rubber,
When the tire is cut by stepping on stones or nails while running and reaches the reinforcing material, the cutting load and corrosion resistance of the reinforcing material decrease.

Further, the adhesiveness between the reinforcing material and the rubber is lowered,
There is also a risk of peeling and causing quality problems in the cut separation of the tire.

Therefore, in order to prevent such cut separation due to corrosion propagation, a cord structure has been proposed in which rubber sufficiently penetrates into the metal cord. For example, JP-A-63-235587 and JP-A-2-15454.
086 and Japanese Patent Laid-Open No. 5-44184 have three cores.
It is disclosed that the number of strands is reduced to 7 to 8 in order to facilitate rubber infiltration while the number of strands is reduced to 2 to eliminate the sealed space, and the filaments of the strands have a patterning ratio of more than 100%. ing.

Further, in Japanese Patent Laid-Open No. 4-327278, in order to maintain a cord cutting load and facilitate rubber penetration,
A metal cord having a single twist structure of × N (N ≧ 6) has been proposed.

[0009] In all of the above-mentioned disclosed examples, the focus is on facilitating rubber permeation and suppressing corrosion propagation, thereby suppressing a decrease in strength due to cord corrosion.

However, this type of cord is subject to oblique shear stress when a stone or the like having sharp corners is stepped on, and the filaments constituting the cord may be broken in addition to the tire tread surface being cut.

Furthermore, for the purpose of preventing the filament from breaking due to diagonal shear stress, a HE cord (high elongation cord) of 4 × 4 or 3 × 7 structure having a small twist pitch with a double twist structure is adopted just below the tire tray. Although tires can be seen (Japanese Patent Laid-Open No. 62-96104), it is difficult to obtain a high elongation even after burying the rubber, and the effect has not been actually obtained.

An object of the present invention is to provide a 3 + 6 two-layer cord, which is commonly used as a reinforcing material for a belt portion of a tire,
A parallel bundled wire with improved corrosion resistance and diagonal shear strength, which has been a problem in the past, and a tire, a conveyor belt, which has improved durability using the parallel bundled wire as a reinforcing material,
It is to provide a composite such as a high pressure hose.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides m (m = m) plates whose surfaces are metal-plated.
9 to 30) thin metal filaments are aligned so as to have a polygonal cross section, and n (n = 1 to 5) thin metal filaments are wound around the outer circumference thereof.

Further, at least m of these metal filaments have a carbon content of 0.65 to 0.78% by weight.
It is more preferable to use the steel wire in the range of m and the m pieces of the restrained metal filaments have a spiral wave-like habit, and the spiral expansion angle is in the range of 78 to 85 °.

On the other hand, the winding pitch pw of n metal filaments is in the range of 4 to 20 mm, and p is the peculiar pitch of m metal filaments, pw <P
Those satisfying the relationship of are preferable.

Further, the diameter of m metal filaments is in the range of 0.15 to 0.30 mm, and this diameter is d
If c and n of them are dw, it is preferable to satisfy the relationship of dw <dc.

A tire, a conveyor belt, a high-pressure hose, etc. made by embedding such a parallel bundled wire as a reinforcing material in a rubber mainly composed of natural rubber or synthetic rubber is the rubber composite of the present invention. Is more durable than the disclosed conventional composites.

The metal plating applied to the surface of the metal filament is brass, in order to improve adhesion with rubber.
It is desirable to coat copper, zinc, or brass with a plating such as a ternary alloy in which an element such as Co, Ni, or Sn is added.

[0019]

In order to improve the diagonal shear strength of the metal cord or the metal filament alone, the filament diameter is made as small as possible, and the twisting amount of the filament by twisting is reduced (the twist pitch is a large pitch). )
Etc., and the metal cord or metal filament embedded in the composite, that is, the tire or the like, can maintain the elongation as high as possible, and the vulcanization molding temperature (140 to
170 ° C.), the influence of blue heat brittleness (or age hardening phenomenon) is small.

As a result of intensive studies from the above viewpoints, in the present invention, a plurality of small-diameter filaments are aligned in a polygonal cross section without being twisted into a metal cord, and then one or more filaments are aligned. A parallel bundle wire was formed by winding with a filament so as not to impair the characteristics of the metal cord.

The number of filaments to be restrained is set to 9 to 30, but if the number is less than 9, it may be unfavorably large in diameter from the filament diameter of the conventional 3 + 6 cord from the viewpoint of maintaining strength, and if it exceeds 30 filaments are aligned. Therefore, it is not preferable because the cost for throwing it into the filament supply device is high and the filament diameter has to be made extremely small in order to suppress the outer diameter of the parallel bundled wire, resulting in an increase in cost compared with the conventional cord.

The cross-sectional shape is polygonal because a circle or an ellipse is preferable from the viewpoint of suppressing the outermost diameter, but a rectangular cross-section (rectangular, semicircular, etc.) may be widely applied depending on the application.

On the other hand, the reason why the number of winding filaments is set to 1 to 5 is that even one filament has a restraining effect, but it is necessary to make the winding pitch relatively small. Although they can be made large, the purpose of these filaments is to restrain the filaments that are aligned and does not contribute to the cutting load and diagonal shear strength. did.

Next, at least the carbon content of the metal filament to be constrained is set in the range of 0.65% to 0.78% by weight. If it is less than 0.65% by weight, the filament diameter is increased to maintain the cutting load as a reinforcing material. Since it is necessary to make the diameter larger, the diagonal shear strength will be reduced, and if it exceeds 0.78% by weight, the influence of blue heat brittleness due to the temperature during vulcanization molding will be large, and the cutting load can be increased. However, since the diagonal shear strength will decrease, this range is desirable.

The constrained metal filament is not twisted, but is imparted with a spiral wave-like habit to facilitate rubber penetration. However, if the temporary twist pitch is made too small, it will be twisted temporarily. Since the filament will be twisted, it is necessary to regulate the spiral expansion angle obtained from the false pitch during false twisting. As a result of repeated tests with various changes in the number of filaments to be restrained and the false twisting curling pitch, when the spiral expansion angle of the filaments located in the outermost layer is set to less than 78 °, the diagonal shear strength sharply decreases and 85 ° If it exceeds, the eccentric deformation becomes an elastic region, and the spiral wave habit does not remain, so the content is set within this range.

If the winding pitch of the filament on the restraining side is less than 4 mm, productivity is impaired and cost is increased, which is not preferable, and if it exceeds 20 mm, the restraining force becomes weak.
Since it is easy to cause a birdcage when a compressive load is applied, this range is set. If the main pitch is equal to or more than the false twisting pitch, the same problem as when it exceeds 20 mm occurs. Therefore, the main pitch is preferably less than the false twisting pitch.

By the way, the diameter of the constrained metal filament that contributes to the strength is smaller as the diameter is smaller as described above, but the smaller the diameter is, the more the cost is increased and the required number is required for maintaining the cutting load. Is needed, and it is necessary to increase the number of feeding devices for bundling in parallel, which is not preferable.
Therefore, considering the number of metal filaments and the cutting load, the appropriate range is set to 0.15 to 0.30 mm.

Since the diameter of the constrained metal filament is desirably suppressed as much as possible as a whole, it is desirable to make it thinner than at least the constrained filament.

[0029]

[Example] Nine of the constrained metal filaments 1 having a diameter of 0.30 mm obtained by brass-plating a steel element wire having a carbon content of 0.72% were preliminarily provided with a spiral wavy habit with a spiral expansion angle of 84 °. Two pieces of the metal filaments 2 having a diameter of φ0.15 mm are bundled at a winding pitch of 8 mm in the applied product, and the result is shown in FIG.
The parallel bundle wire of Example 1 shown to A was obtained.

Next, as shown in FIGS. 1A and 1B, the number and diameter of the restrained filaments 1 were changed to produce a parallel bundled wire having a cutting load of substantially the same level. This is set as Examples 2, 3, and 4 shown in Table 1.

Further, while changing the carbon content rate of the steel wire and the squeezing pitch of the constrained bundled metal filaments, a parallel bundled wire was produced in which other conditions were adjusted to the above contents as much as possible. Examples 1, 2, 3 and Examples 5, 6
And

Conventional cords having a 3 + 6 structure were manufactured by changing only the carbon content, and the cords are designated as Conventional Examples 1 to 4 in Table 1.

Using the above samples, the oblique shear strength retention rate, which is a substitute characteristic of the cut resistance of the tire tread surface, and the rubber penetration, which is a substitute characteristic of the corrosion resistance, were measured. The results are shown in Table 1 below. As can be seen from the table, Examples 1 to 6
Has a higher oblique shear strength retention rate as compared to Conventional Examples 1 to 4 and Comparative Examples 1 to 3, and has a much higher rubber penetration than Conventional Examples 1 to 4, and is superior to conventional cords and Comparative Examples. Has been obtained.

In the diagonal shear load test apparatus shown in FIG. 3, a screw is formed in a guide 5 on the side of the intermediate portion of the sample 3 such as a metal cord and a parallel bundle wire that are laid between a pair of cylindrical fixing pins 4. A moving pin 7 whose tip is an arc having a radius R is attached to the tip of the screwed-in screw rod 6 through a joint so that the moving pin 7 does not rotate even if the screw rod 6 rotates. Then, one end of the sample 3 is fixed by the chucking jig 10, the screw rod 6 is rotated by the handle 12, and when the sample 3 is passed through the tip of the movable pin and the fixed pin 4, positioning is performed so as to have a predetermined bending angle α. Then, while pressing the cord on the tip of the radius R of the moving pin 7, the fixed pin 4
While the sample 3 is sandwiched by one chucking jig 11 via the indexing device and indexed in one direction, the load at the time of cutting at the position of the moving pin 7 is measured.

[0035]

[Table 1]

The "oblique shear strength retention rate" in Table 1 is the oblique shear load in which bending is applied under a constant condition with respect to the cutting load of the sample, and is expressed as a percentage. The test condition is α in FIG. = 40 ° and R = 0.2 mm. The "cord / rubber composite" in Table 1 is a sample for a tensile test after embedding and vulcanizing the sample in the rubber and taking out so that the rubber having a thickness of 1 mm remains in the test piece. The "rubber penetration" in Table 1 is a value obtained by embedding and vulcanizing in rubber and then collecting the wire of the center layer and measuring the rubber adhesion rate on the surface.

[0037]

[Effect] As described above, according to the present invention, it is possible to suppress the decrease in diagonal shear strength and to improve the corrosion resistance due to the good rubber penetration, so that it can be sufficiently applied to tires such as trucks and buses. Also, in terms of manufacturing, there is no need to twist the cords unlike the conventional cords, and therefore, there is an advantage that the manufacturing can be performed efficiently and inexpensively.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of an embodiment.

FIG. 2 is an enlarged cross-sectional view of a conventional example.

FIG. 3 is a side view of a diagonal shear load test device.

[Explanation of symbols]

 1 constrained metal filament 1'metal filament 2 metal filament 3 sample 4 fixing pin 5 guide 6 screw rod 7 moving pin 10 chucking jig 11 chucking jig 12 handle α bending angle R bending radius

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[Procedure amendment]

[Submission date] March 2, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

Further, the adhesiveness between the reinforcing material and the rubber is lowered,
There is a risk of peeling and causing quality problems such as tire cut separation.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction content]

In the diagonal shear load test apparatus shown in FIG. 3, a screw is formed in a guide 5 on the side of the intermediate portion of the sample 3 such as a metal cord and a parallel bundle wire that are laid between a pair of cylindrical fixing pins 4. the tip of the screw rod 6 is screwed to attach the moving pin 7 in which the tip an arc of radius R as the mobile pin 7 also threaded rod 6 is rotated attached via a joint does not rotating. Then, attach one end of the sample 3 to the chucking jig 1
After fixing with 0, the screw rod 6 is turned by the handle 12 and positioned so that a predetermined bending angle α is obtained when the sample 3 is passed through the movable pin tip and the fixed pin 4, and then the movable pin 7 has a radius R. via the fixing pins 4 while pressing the cord while 牽 pulling in one direction across the sample 3 by one of the chucking jig 11 to measure the load when cut at a position of the moving pins 7.

[Procedure amendment]

[Submission date] October 12, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

Further, the adhesiveness between the reinforcing material and the rubber is lowered,
There is a risk of peeling and causing quality problems such as tire cut separation.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction content]

In the diagonal shear load test apparatus shown in FIG. 3, a screw is formed in a guide 5 on the side of the intermediate portion of the sample 3 such as a metal cord and a parallel bundle wire that are laid between a pair of cylindrical fixing pins 4. the tip of the screw rod 6 is screwed to attach the moving pin 7 in which the tip an arc of radius R as the mobile pin 7 also threaded rod 6 is rotated attached via a joint does not rotating.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area // B29K 21:00

Claims (7)

[Claims] 1. m pieces (m = 9) whose surface is plated with metal.
To 30) thin metal filaments are aligned so as to have a polygonal cross section, and n (n = 1 to 5) thin metal filaments are wound around the outer circumference of the parallel bundled wire. 2. The parallel bundled wire according to claim 1, wherein at least m of the metal filaments are steel strands having a carbon content in the range of 0.65 to 0.78% by weight. . 3. The m-piece restrained metal filaments have a spiral wave-like habit, and the spiral expansion angle of the metal filaments is in the range of 78 to 85 °. Parallel bundled wires. 4. The winding pitch pw of the n metal filaments is in the range of 4 to 20 mm, and p is the pitch of the m metal filaments.
The parallel bundled wire according to any one of claims 1 to 3, characterized in that the relationship (1) is satisfied. 5. The diameter of the m metal filaments is in the range of 0.15 to 0.30 mm.
The parallel bundled wire according to any one of 1. 6. The diameter of the m metal filaments is d
c, and the diameter of the n metal filaments is dw,
The parallel bundled wire according to any one of claims 1 to 5, which satisfies a relationship of dw <dc. 7. A tire, a conveyor belt, a high pressure hose, etc. made by embedding the parallel bundled wire according to any one of claims 1 to 6 in a rubber mainly composed of natural rubber or synthetic rubber as a reinforcing material. A composite of parallel bundled wires and rubber.