JPS6347130A - Manufacture of topping sheet for tire - Google Patents

Abstract

PURPOSE:To eliminate the need of a sewing process and at the same time obtain a homogeneous tire by a method wherein the supply of a plurality of cords arranged in the form of a sheet to a topping device is performed by rewinding a plurality of cords from a beam, onto which a plurality of the cords have been wound-up so as to be arranged parallel to one another. CONSTITUTION:A plurality of dip cords are rewound from a beam 1, onto which a plurality of the dip cords have been wound up, and fed through a plurality of guide rollers, accumulators 2 and tension control rolls 3 to calender rollers 4, at which rubber is topped. In order to manufacture an excellent topping sheet, the ratio of shrinkage factor (S) to intermediate elongation (E) of cords, which are paralleled in one direction, must be O<S/E<=0.25, preferably, O<S/E<=0.20. As for the method to obtain a cord having the characteristic of O<S/E<=0.25, there is no special requirement. For example, the following method may be adopted. (1) A large number of cords are arranged in parallel and subjected to relaxing treatment before topping. (2) Relaxed cords are arranged in parallel and, after that, topped.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing a topping sheet for tires. More specifically, the present invention relates to a method for producing a tire topping sheet in which a plurality of cords constituting the topping sheet are arranged in parallel without being restrained from each other, thereby producing a tire with excellent flatness and high quality.

[Conventional technology]

Conventionally, topping sheets for tires are made by warping cords obtained by heating a single or multiple threads and weaving them into a blind fabric with a weft density of 6 to 12 threads/10 cm using a loom. It is formed by attaching a rubber layer to at least one side, usually both sides, of a fabric. Note that the cord is treated with an adhesive, that is, treated with a dizzo treatment, before being attached to the rubber layer.

However, originally, this weft yarn is not effective at all in reinforcing the tire, and is also a factor that prevents uniform inflation during tire molding, especially radial tires. In other words, it is important for carcass materials for radial tires to uniformly undergo the large deformation that occurs during vulcanization molding in order to ensure uniformity of the tire. Spun yarns made of , cotton, rayon, polynosic, nylon, ester, etc. intersect with the cord, which restricts the degree of freedom of the cord and inhibits uniform inflation during vulcanization. For this purpose, 1) the weft is cut by a latitudinal cutting device called a big breaker in the process of sandwiching it between rubber sheets (hereinafter referred to as topping); 2)
By using a high elongation weft obtained from undrawn yarn such as nylon or polyester, the resistance between the cords due to inflation during tire vulcanization molding can be reduced as much as possible and uniform deformation can be promoted. It has been done.

These methods have achieved uniform inflation during molding of the tire.

On the other hand, the performance requirements for tires are becoming increasingly higher and stricter, and there is a need for the development of uniform, high-quality tires. One solution to this problem is to straighten the warp cords, which tend to rise and fall vertically due to intersecting the weft threads. That is, by using a special loom or warp knitting machine, or by using a hot melt adhesive or the like, it is attempted to obtain a sheet-like product in which warp cords do not intersect with other materials.

However, all of these methods 1) involve a large amount of other material components other than the cord, such as wefts, which increases the weight of the reinforcing material; 2) troubles are likely to occur during the adhesive treatment process; 3)
There are problems such as: the flatness of the topping sheet as a whole is not good because the cord moves easily during the processing process.

[Problem that the invention seeks to solve]

In order to manufacture high quality tires, the present invention is an industry that manufactures tire topping sheets that allow uniform inflation during vulcanization molding, have good straightness of the cord itself, are lightweight, and have excellent overall flatness. The purpose is to provide a simple and convenient method.

[Means for solving problems]

An object of the present invention is to provide a method for manufacturing a tire topping sheet by applying a rubber layer to at least one side of a sheet-like sheet in which a plurality of cords are arranged in parallel without being constrained by each other using a topping device. A method for manufacturing a tire topping sheet, wherein the plurality of sheet-like cords are supplied to the topping device by unwinding the plurality of cords from a beam in which the cords are arranged in parallel and wound. It is achieved by being busy.

As described above, the method for manufacturing a tire topping sheet according to the present invention is characterized in that a plurality of cords are supplied from a beam. The entire process of manufacturing tire topping sheets includes a dipping process to treat the twisting yarn and adhesive, a tension heat setting process to improve the dimensional stability of the cord, a beam winding process, and a topping process. As will be described later, relaxation processing is performed before or after beam winding in order to bring the characteristics of the cord into a desirable range.

The adhesive-treated cord, that is, the dip cord, may be wound onto the beam directly by a commonly used multi-type cord processing machine (the number of cords supplied is, for example, 50 to 500), or the dip cord may be wound once on the beam. ? After wrapping it in a hin, many? The bottles may be aligned and re-wound onto the beam, and various methods may be employed.

Also, each dip cord can be wound onto the beam. The cord needs to be wound up under uniform conditions, preferably under a load of o, oi to 0.5 g/D (D indicates the total denier of the yarn constituting the cord). The cord density of the dip cord wound onto the beam may be appropriately selected within a range that does not interfere with the supply to the topping.

To arrange the cords uniformly in parallel, various commonly used guides such as a rotating type or a comb type, a grooved roller, etc. may be used. Furthermore, a sheet such as a liner cloth may be rolled up between the cord layers so that the plurality of cords can be released from the beam without any hindrance during topping. At the beginning and end of the beam winding, in order to facilitate the joining of the cords, it is preferable to use, for example, a spacer, a holding plate, a sandwiching sheet, etc. that will keep the cords in a parallel state.

FIG. 2 shows an example of the topping step in the method for producing a topping sheet according to the present invention. The multiple dip cords are unwound from the beam 1 into which the multiple dip cords are wound, and the multiple dip cords are sent to the idle roller and accumulator 2.
, and is supplied to a calender roller 4 via a tension adjustment roll 3, where it is topped with rubber. The plurality of topping-treated cords are formed into a sheet shape, passed through a cooling roll 3ζ accumulator 2', and are wound up on a topping sheet winding beam 6 together with liner cloth supplied from a liner cloth supply roll 5.

Typically, cords constructed from fibrous materials are subjected to tension heat setting before or after adhesive treatment, as described above, to improve their dimensional stability as reinforcement.

However, in this process, it is difficult to completely set the fine structure and twisted structure of the cord, and internal strains that were temporarily fixed during the setting become apparent due to subsequent changes in the external environment such as heating and humidification, causing shrinkage. present. As a result, ordinary cords that have only been treated with adhesive and set will shrink during the topping process. That is, if the cord shrinks due to the thermal history it undergoes during the topping process, which is usually carried out at 100 to 150°C, a flat topping sheet cannot be obtained.

In particular, when the shrinkage rates between the cords are significantly different, the workability itself in the topping process becomes a problem.

Therefore, in order to manufacture an excellent topping sheet by the manufacturing method according to the present invention, it is necessary to wind up a stable cord with extremely low shrinkage rate during the topping process and supply it to the topping process. That is, the cords arranged in parallel in one direction used in the manufacturing method according to the present invention have a ratio of release contraction rate (S) to intermediate elongation (E) of O<S/
E≦0.25, preferably 0<S/E≦0.20. S has a characteristic commensurate with the shrinkage rate in the topping process, and a method for reducing S is important. When S/E) is 0.25, problems tend to occur in the topping process as described above.

S and E are selected depending on the tire performance and the material of the reinforcing material, but usually E is 1≦E≦101, preferably 2≦E≦
In the range of 9, if E is small, S/E will be large, and E
If the value is large, the rigidity of the manufactured tire will decrease.

Also, S is usually in the range of 0≦S≦2, preferably O≦S≦1.5, and in order to maintain flatness, it is better to have a smaller S, but if S is negative, that is, if it stretches It becomes difficult to match the characteristics among many codes.

Although the method for obtaining the code having the characteristics of 0 (S/E≦0, 25) is not particularly limited, the following method may be considered, for example.

1) Parallel a large number of codes and perform relaxation processing before topping.

2) Arrange relaxed chords in parallel and add topping.

Furthermore, the relaxation method should be selected so that S is in the range of 0≦S≦2. - For boat fishing, under low tension, use hot air, superheated steam, heating heater, heating roll, infrared heating. , dielectric heating, etc. alone or in combination may be applied.

The fiber material constituting the cord used in the manufacturing method of the present invention includes all organic fibers that are used or can be used as tire cords, such as nylon 6.66
．． Polyamide fibers such as Noyara phenylene terephthalamide and aromatic ether copolymers; Polyester fibers such as polyethylene terephthalate; Fully aromatic polyester fibers; Vinylon fibers; Rayon fibers : Polyolefin fibers such as ultra-high molecular weight polyethylene; polyoxymethylene fibers; etc. Depending on the case, appropriate amounts of carbon fibers, ceramic fibers, metal fibers, etc. may be used in combination.

The organic fiber material may contain various additives that are commonly used to improve productivity or properties in the manufacturing process or processing process of raw yarn.

For example, it may contain a heat stabilizer, an antioxidant, a light stabilizer, a smoothing agent, a plasticizer, a thickener, a pigment, a gloss imparting agent, a flame retardant, and the like.

The number of twists of the cord is T1, the number of twists per 10 crn, and D, the total denier of the yarn that makes up the cord, K = TX
The twist coefficient determined by 1” T5- is 1700≦≦22
00, preferably in the range of 1800≦2100.

The adhesive applied to the cord may be selected depending on the fiber type and tire type. For example, epoxy resin: isocyanate compound used as an adhesive for tire reinforcement materials;
Polyurethane compounds; ethylene urea compounds; polyethylene imine compounds; phenolic compounds: halodanated phenol and formalin condensates; melamine compounds; polysulfurized polyphenol compounds; resorcinol/formalin initial condensates and rubber latex mixture; Dem glue, etc. are selected as appropriate. However, they may be used alone, in combination, or in combination, but are not limited to these.

The method of applying adhesive to the cord may also be selected from commonly used methods. Examples include, but are not limited to, a dipping method, a coating method, a spray method, a nozzle method, and the like.

The adhesive contains anti-aging agents, antioxidants, heat stabilizers, thickeners, antifoaming agents, smoothing agents, pigments, carton black, etc. for the purpose of improving properties such as adhesiveness and processability. It may also contain additives.

Further, drying and curing performed subsequent to the application of the adhesive may be performed using a method appropriately selected from among the various heat media used for relaxing the cords described above.

The amount of adhesive applied is 2 to 7 parts by weight, preferably 3 to 6 parts by weight.

A large number of cords supplied from a beam and arranged in one direction are usually narrowed from both sides by a thin comb sheet in a topping process, but this process is not particularly limited either. The distance between the cords should be maintained evenly - considering the mechanism,
It may be laminated with a comb sheet on one side at a time or on both sides simultaneously using a mold or a two-type calender.

The materials used for the rubber sheet may be mixed appropriately depending on the tire type, reinforcement area, etc., and are usually natural rubber, styrene/butadiene copolymer comb, carbon black, vulcanizing agent, vulcanization accelerator, and vulcanization. Retarders, anti-aging agents, lubricants, process oils, mold release agents, etc. are used.

The tires manufactured according to the present invention are not particularly limited, and are radial tires, such as those used for passenger cars, light trucks, truck passes, construction vehicles, industrial vehicles, motorcycles, bicycles, etc. However, there is no problem in applying it to other uses and bias tires.

Note that the sheet-like material in which multiple cords are arranged in parallel without being constrained by each other in Kikiri and Hosobi primarily refers to sheet-like materials that do not use wefts, such as in blind weaving, but there are other Materials that are entangled, pinched, or in contact with the weft cord, such as entangled threads, hot melt adhesives, thermosetting resins, rubbers, or mixtures thereof.It also refers to sheet-like materials that do not use weft threads. do.

〔Example〕

The present invention will be explained below based on examples.

Prior to the description of Examples, the definition and measurement method of the elongation ratio (S) and the intermediate elongation (E) described in this specification will be explained.

The elongation (S) is measured from cords taken immediately before topping, and the intermediate elongation (E) is measured from cords taken within 1 hour after adhesive treatment. The degree of contraction S is measured by the measuring method shown in FIG. That is, sample S. The sample is fixed at points a and b so that the hanging length of load point C8 at the center of the sample becomes ho under an initial load of 3 g/cord. Then, the initial load was removed and the product was left under its own weight in an atmosphere of 24°C and 55% RH for 6 days.

After that, the sample S1 is hung again under the initial load, BL at point 01 is read, and S is calculated using the following formula using 6, ho, and h.

tQ=2 2, 68X10 XDXl, 14X1/ρ (D
is the total denier of the yarn constituting the cord, and ρ is the elongation rate when the specific gravity of the yarn is > kg.

Specifically, nylon is 1260D/2: polyester, aramid: 1500D/2: rayon 1650D
/2; 6.75kli for vinylon 1300D/2
It refers to the elongation rate at 1 o'clock, and if the fibers have different deniers, the elongation rate under load may be calculated according to the denier ratio.

The measurement conditions were: sample length 25 mm, tensile speed 30 crn/min,
Chart speed is 60m/min, 24℃×551RH,
Measurement is performed after being left under its own weight for 24 hours.

In addition, the topped rubber/cord composite sheet was wound up into a roll, left indoors for one week, then pulled out, and the quality of the topping sheet was qualitatively judged.

Example 1 Two 1260D 66 nylon threads were separately twisted (39 times/10 tyn in two directions), then the two threads were pulled together, and further twisted (39 times/10 cm in the S direction). I created a code for 1260D/2. Next, this cord was immersed in RF/LK, and the first zone temperature was 160°C.
Tension: 14 kg/cord, time: 120 seconds; 2nd zone temperature: 227°C, tension: 2.8 kg/cord, time: 4'0 seconds; 3rd zone temperature: 227°C, tension: 1.8 to 9/cord time: 4
Tension heat setting was performed in 0 seconds.

50 cords obtained in the same way were pulled together and the tension was about 6
It was wound onto a beam with a width of 5 crn under 0 g/cord and relaxing in a heating zone of 180'°C x 1.5 seconds. Next, it was topped with tire carcass rubber using three rolls. The cord/rubber laminate sheet was rolled up along with the liner and its flatness was determined. Table 1 shows the characteristics of the obtained code.

Example 2゜ 150002 polyester raw yarns were separately twisted (40 times/10 in two directions), then the two yarns were pulled together and further twisted (40 times/10 cm in the S direction) to create a twist of 150,000.
I created a code for D/2. Next, use this code as Noruka? RF/L
Immersed in a mixed solution containing 20 parts by weight per 100 parts by weight, first zone temperature 160°C, tension 3.0 kg/cord, time 120 seconds: second zone temperature 245°C, tension 3.0
kg/cord, time 45 seconds: 3rd zone temperature 245℃,
Tension heat setting was performed at a tension of 2.0 kg/cord and a time of 45 seconds. Pick up the 50 codes obtained in the same way,
190 with hot roller under tension of about 50g/cord
It was relaxed for 1 second at ℃ and then rolled up into a beam with a width of 6 cTn.

Next, topping was performed according to Example 1, and the flatness of the laminated sheet was determined. Table 1 shows the characteristics of the obtained code.
Shown below.

Example 3 Two 840D 66 nylon yarns were first twisted separately (four in two directions).
9 times/10 cm) and align these two pieces,
Further twist (49 times/10 cm in S direction) is added to make 8
40 Created a D/2 code. This code is 10
After being immersed in RF/L by a multi-code processing machine for zero weight,
1st zone temperature 150℃, stretch +8, time 10
0 seconds; 2nd zone temperature 225°C, stretch +1, 5, time 40 seconds; 3rd zone temperature 225°C, stretch -
2.0%, tension heat set for 40 seconds, tension approximately 4
At 0 g/cord, a polyethylene sheet with a thickness of about 0.05 mm was sandwiched in a width of 8 saws and rolled up onto a beam.

Just before topping, heat on hot plate 200℃, 0.7
After relaxing for a few seconds, topping was performed according to Example 1. Table 1 shows the flatness of the laminated sheet and the characteristics of the obtained cord.

Example 4 Kevlar (aramid fiber manufactured by DuPont) yarn 1500D
First twist the three strands separately (30 times/10(1) in two directions), pull these three strands together, and then top twist (30 times/10 c in the S direction).
rn) to create a 1500D/3 code.

Next, this cord was immersed in an aqueous solution of epoxy resin 2, treated at 250°C in zone 1, tension 4.5 kg/cord, for 90 seconds, and then immersed in RF/L, treated in zone 2 at 160°C, tension 3yu/code, time 120 seconds; 3rd
Tension heating was performed at a zone temperature of 250° C., a tension of 3 Yu/cord, and a time of 60 seconds.

50 cords obtained in the same way were pulled together and the tension was approximately 1.
00g/cord, hot roll 200℃ x o, s
A second relaxation was performed and the beam was rolled up to a width of 10 crn.

Topping was performed according to Example 1, and the flatness of the laminated sheet was determined. Table 1 shows the characteristics of the obtained code.

Comparative Example 1, Example 1. In this case, the topping was done without relaxing when hoisting onto the beam. Table 1 shows the characteristics of the cord and topping processability.

If you do not relax, the cord will shrink unevenly during topping, which will hinder the topping process.
The flatness of the laminated sheet is also not good.

Margins below [Effects of the Invention] By using the manufacturing method according to the present invention, the conventional weaving process can be omitted, and the preparation process for the topping process can be simplified.

Furthermore, since no weft is used, uniform deformation between the cords during vulcanization and molding is promoted, thereby making it possible to provide a homogeneous tire.

[Brief explanation of drawings]

Figure 8g1 is a diagram explaining the method for measuring the emissivity S. A: Sample when fixed under initial load (length t.), 6th: height of sample when fixed, h: height after being left for 6 days. FIG. 2 is a schematic front view showing an example of the topping step in the method for producing a topping sheet according to the present invention. 1 is a beam around which dip cord is wound, 2 and 2' are an accumulator, 3 is a tension adjustment roll, 3' is a cooling roll, 4 is a calendar roll, 5 is a liner cloth supply roll, and 6 is a topping sheet winding beam. be.

Claims (1)

[Claims] 1. A method for manufacturing a tire topping sheet by pasting a rubber layer on at least one side of a sheet-like material in which a plurality of cords are arranged in parallel without being constrained by each other using a topping device, the manufacturing method comprising: A method for producing a topping sheet for a tire, wherein a plurality of sheet-like cords are supplied to a topping device by being unwound from a beam on which the plurality of cords are arranged in parallel and wound.