JPS62299331A - Topping sheet for tire - Google Patents

Abstract

PURPOSE:To obtain a topping sheet for a tire having not only a good linearity but also an excellent flatness, by specifying a ratio of an aging ratio (S) and an intermediate elongation (E) as a code, and using the code treated with an adhesive. CONSTITUTION:Codes arranged parallel in one direction used in a topping sheet have a ratio of an aging ratio (S) and an intermediate elongation (E) of 0<S/E<=0.25, preferably 0<S/E<0.20; in case of S/E>0.25 no flat topping sheet is obtained. A fiber material constituting each code comprises a polyamide fiber comprising nylon 6, 66 or 46 or a polyester fiber represented by polyethylene terephthalate. As materials of a rubber sheet to be used, natural rubber, styrene/butadiene copolymer rubber, carbon black, a vulcanizing agent, a vulcanization accelerator, a vulcanization retarder, an aging inhibitor, a lubricant, process oil and a release agent etc. are used and a topping sheet manufacturing process is performed in order of yarn twisting, adhesive treatment, setting, relaxing and topping. By this method, a uniform high grade tire can be formed.

Description

[Detailed description of the invention] 3. Detailed description of the invention <Industrial application field> The invention relates to a topping sheet for tires.

More specifically, this article relates to 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 achieving excellent flatness and capable of producing Akane grade tires. 〉 Conventional tire topping sheets are single or l! !
The cord obtained by heating several yarns is warped and woven into a blind fabric with a weft density of 6 to 12 threads/10 threads on a loom, and the blind fabric is coated on at least one side, usually on both sides. Formed by pasting rubber #.

However, these weft yarns are not originally effective in reinforcing tires, and are also a factor in preventing uniform inflation 2 during tire molding, especially radial tires. In other words, it is important for the carcan material of radial tires to uniformly undergo the large deformation that occurs during vulcanization molding in order to ensure the uniformity of the tire. Spun yarns made of cotton, rayon, borino, resin, nylon, ester, etc., intersect with the cord, restricting the degree of freedom of the cord and inhibiting uniform inflation during vulcanization. For this purpose, 1) the weft is cut by a rubber sheet sandwiching process (hereinafter referred to as topping) using a latitudinal cutting device called a cube breaker; 2) a high elongation weft using undrawn yarn or the like is used; These methods have been used to reduce as much as possible the resistance force between the cords due to inflation during tire vulcanization molding, and to promote uniform deformation. These methods have achieved uniform inflation during tire molding.

On the other hand, the performance requirements for tires are becoming increasingly higher and stricter, and there is a need to develop more uniform and high-quality tires. One solution to this problem is to straighten the warp cords, which float up and down due to intersecting the wefts. That is, by using a special loom or a warp machine, or by using a hot melt adhesive or the like, an attempt is made to obtain a sheet-like product in which warp cords do not intersect with other materials.

However, all of these methods increase the amount of other material components other than the cord, such as the 1-inch weft, and the weight of the reinforcing material increases; 2) Troubles are likely to occur in the adhesive treatment process; 3)
) The cords tend to move during the processing process, so the flatness of the topping sheet as a whole is not good.

<Problems to be Solved by the Invention> In order to manufacture high-quality tires, the present invention is capable of uniform inflation during vulcanization molding, has good straightness of the cord itself, is lightweight, and has good flatness as a whole. The purpose of the present invention is to provide an excellent tire topping sheet.

The present invention provides a topping sheet in which a rubber layer is adhered to at least one side of a sheet-like sheet in which cords of a plurality of rates are arranged in parallel without being mutually restrained. The cord has a ratio of release contraction rate (S) and intermediate elongation (1) of 0<S
/]! , ≦0,25, and is achieved by a topping sheet for tires characterized by using an adhesive-treated cord. By using the inventive topping sheet, it is not only possible to omit the conventional weaving process, but also to provide a homogeneous tire by promoting uniform deformation between the cords during vulcanization molding. be able to.

Typically, cords made of fibrous materials are tensioned and heat set before or after adhesive treatment to improve their dimensional stability as reinforcement. However, in this process, it is difficult to completely set the fine barrel structure and twisted structure of the cord, and due to subsequent changes in the external environment such as heating and humidification, the internal distortion that was temporarily fixed at the time of setting becomes apparent and shrinks. exhibits a phenomenon. Namely, adhesive treatment and setting? Ordinary cords that have just been applied will shrink during the topping process.

The present invention is characterized by the use of a stable cord that exhibits extremely low shrinkage during the topping process. If the cord shrinks due to the thermal history it undergoes during the topping process, which is usually carried out at 100-150C, a flat topping sheet cannot be obtained.

Particularly when the shrinkage rates between the cords are greatly different, the workability itself in the topping process becomes a major issue.

That is, the cords arranged in parallel in one direction used in the topping sheet of the present invention have a release contraction rate (S) and an intermediate elongation (E
) is preferably 0<s/≦α25, preferably 0<s/≦CL
It needs to be 20.

S is a property commensurate with the shrinkage rate in the topping process,
A method for making S smaller is important.

S/. >0.25, problems in the topping step as described above are likely to occur.

In the present invention, S and E are selected depending on tire performance and the material of the reinforcing material, but usually E is in the range of 1≦E≦10, preferably 2≦E≦9, and if E is small, When S/X becomes large and E becomes large, the yield of the manufactured tire decreases.

Also, S is usually in the range of 0≦S≦2, preferably 0≦S≦t5, and in order to maintain flatness, it is better to have S smaller, but S is negative, that is, if it stretches, there will be a gap between many cords. It becomes difficult to match the characteristics of The method of obtaining the code having the characteristic of 0/8≦CL25 used in the present invention is not particularly limited, but for example, the following method can be considered.

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

2) Arrange relaxed chords in parallel and add topping.

Furthermore, the method of relaxation can be selected so that S is in the range of 0≦S≦2, and generally under low tension, hot air, superheated steam, heated heaters, heated rolls, etc. Heat treatment may be performed using infrared heating, dielectric heating, etc. alone or in combination.

Furthermore, since the topping sheet of the present invention is bonded to the rubber layer in the topping step, it must be treated with an adhesive to the rubber. If no adhesive treatment is performed, the adhesion to rubber will be poor. The method of adhesive treatment is not particularly limited; 1) Untreated cords are arranged in parallel and treated with adhesive before the binding process.

2. Single cords are treated with adhesive in advance and placed in parallel.

etc. are possible.

The content of the adhesive may also be selected depending on the fiber mass and tire type. For example, epoxy resins used as adhesives for tire reinforcing materials; A polysulfurized polyphenol compound; a mixed liquid of resorcin/formalin initial condensate and rubber latex; rubber glue, etc. may be appropriately selected and used alone, in combination, or in combination, but the present invention is 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.

Additives such as anti-aging agents, antioxidants, heat stabilizers, thickeners, antifoaming agents, smoothing agents, pigments, and carbon black are added to the adhesive to improve properties such as adhesiveness and processability. It may contain.

Further, the drying and curing performed subsequent to the application of the adhesive may be performed by applying 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% by weight, preferably 3 to 6% by weight.

Furthermore, the fiber material constituting the cord, which is the object of the invention, includes all organic fibers that are used or can be used as tire cords, such as nylon 6.66.4.
6 and other polyamide fibers; aramid fibers typified by copolymers of phenylene tereathalamide and aromatic ether; polyester fibers typified by polyethylene terephthalate; wholly aromatic polyester fibers;
vinylon fiber; rayon m fiber; polyolefin fiber such as ultra-high molecular weight polyethylene; polyoxymethylene fiber;
and so on. Depending on the case, appropriate amounts of carbon fibers, ceramic fibers, resin 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, heat stabilizers, antioxidants, light stabilizers, smoothing agents, plasticizers, thickeners, pigments, brightening agents, flame retardants, and the like may be included.

A large number of cords arranged in one direction are usually narrowed from both sides with a thin rubber sheet in a topping process, but this process is not particularly limited either. Code opening M [Considering the spacer mechanism to maintain uniformity, it is sufficient to laminate one side at a time or both sides simultaneously with a rubber sheet using an L-type or 2-type calender.

The materials used for the rubber sheet can be mixed as appropriate depending on the tire reinforcement area, etc., and are usually natural rubber, styrene/butadiene copolymer rubber, carbon plastic, vulcanizing agent, vulcanization accelerator, Vulcanization retarders, anti-aging agents, lubricants, process oils, mold release agents, etc. are used.

The manufacturing process of the topping sheet according to the invention consists of twisting, adhesive treatment and setting, relaxing, and topping. In implementation, each step may be performed separately, or if possible, a plurality of steps may be performed consecutively.

For example, the twisting and setting, the twisting, setting, and adhesive treatment may be performed at the same time, or the adhesive treatment, 7, 7, and relaxing may be performed successively.

The number of twists of the cord is, where the number of twists per 10 (to) T1 is the total denier of the yarn that makes up the cord, = T
The twist coefficient determined by X V5 is 1700≦≦2200
, preferably in the range of 1800≦X≦2100.

By using the topping cord according to the present invention having the configuration described above, it is possible to manufacture uniform and high-quality tires.

If cords that do not have the characteristics specified by the present invention are simply arranged in parallel and subjected to topping processing, trouble will occur in the topping process. If the cutting method is adopted, unnecessary weft threads remain in the rubber, and problems arise in that the weft threads are overlapped and the straightness of the cord is not perfect.

<Example> The present invention will be explained below based on examples.

Prior to the explanation of the examples, the elongation rate (S) and the intermediate elongation (K
) and how to measure it.

The elongation (El) is measured from cords taken within one hour before topping, and the intermediate elongation (E) is measured from cords taken within one hour after adhesive treatment.

The degree of contraction S is measured by the T measurement method shown in FIG.

That is, sample S. 5? / Drooping length at 0° load point at the center of the sample under the initial load of the cord. So that a.

Fix the sample at point b. Then, the initial load was removed and the sample was left under its own weight in an atmosphere of 24C and 55% RH for 6 days. Thereafter, the sample S is hung again under the initial load, hl at the O4 point is read, and S is determined from the following formula using 'kLo, h1Tr:'.

to = 2X (ho”+L2)/2t1= 2X
(h,'+L2)7'2 Intermediate elongation <V) is obtained from the load-elongation curve measured with a tensile tester 2, 68X10 XI) Xl, 14X1
/P (D is the total denier of the yarn constituting the cord, P is the specific gravity of the yarn) 11:00 elongation rate.

Specifically, nylon is 1260 D/2; polyester and aramid are 1500 D/2; rayon 1
650D/2; for vinylon 1300 D/2, &7
This refers to the elongation rate at 5kp, 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 25a1k, tensile speed 30 plows/min,
Chart speed is 60Cm/min, 24C x 55%RH
, measured 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 66 nylon yarns 1890D were separately twisted (32 times/10 (m) in two directions), pulled together, and further twisted (32 times/10% in the S direction). 1890D
/2 code was created. Next, after immersing this cord in resorcin/formalin, the first zone temperature was 160C,
Tension heat at 2.0 to 9/cord, time 120 seconds; second zone temperature 232C, tension 4.0kp/cord, time 40 seconds; third zone temperature 252C, tension 2.6kp/cord, time 40 seconds. I did a set.

A large number of cords obtained in the same way were lined up and the tension was about 50.
1/cord, the topping process was performed by relaxing in the heating zone 180CX for 2 seconds.

The cord/rubber laminate sheet was rolled up together with the liner and its flatness was determined. The characteristics of the cord used are shown in Table 1. Example 2 Kepler (Aramid fiber yarn 1500D manufactured by Debon Co., Ltd.)
A 1500 D/2 cord was created by separately adding a first twist (69 turns/10 m in the two directions) to the two strands, then pulling the two strands together and adding a final twist (39 twists/10 m in the S direction). Then,
After immersing this cord in a 2% epoxy resin aqueous solution, the first zone humidity was 250 C1, the tension was 3.5, 9/cord, and the time was 60.
Second zone temperature 16C1, tension 2ky/cord, time 10 after second kina treatment and immersion in resorcin/formalin.
0 seconds; 3rd zone temperature 250C, tension 2 l/cord,
Tension heat setting was performed for 60 seconds.

Immediately before winding the cord, roll it using a hot roll for about 10 minutes.
Relaxation was performed at 150C for 1.5 seconds under a tension of 0p/cord.

A large number of codes obtained in the same way were arranged, tagged, and pinged. Table 1 shows the characteristics of the code used.

Example 3゜In Example 1, the temperature of the heating zone was changed from 50 to 200C.
We have obtained codes with various characteristics. Edit these codes according to Example 1.

I did a ping. Table 1 shows the characteristics of the codes used.

Example 4 Two 1500D polyester yarns were first twisted separately (40 times in two directions/10 dll), and then the two yarns were twisted together (40 times in S direction/10Cn&) and twisted to 1500 D.
I created a code for D/2. Then change this code to
Valkabond E (Varna, manufactured by Cus?a) was immersed in a mixed solution containing 20 parts by weight of resorcin/formalin 100 fij, the first zone temperature was 160 G, and the tension was 2.0.
kp/: 7-cord, time 120 seconds; second zone wetness 245 tl; tension 3.0 kl/cord, time 60 seconds; third zone temperature 245 tT.

Tension heat setting was performed at a tension of 2.5 kp/cord and a time of 60 seconds.

A large number of cords obtained in the same way were arranged and tensile
) / Under the code, I relaxed at 200CX 1 second at the dove rate and topped it. The cord/rubber laminate sheet was rolled up along with the liner and its flatness was determined. Table 1 shows the characteristics of the codes used.

A comparative example was used in Example 1 without relaxing immediately before topping.The characteristics of the cord used and the topping processability are shown in Table 1.

If relaxation is not carried out, the cord will shrink significantly during pinging, resulting in folded cords and poor flatness of the laminated sheet.

Table 1 Main advantages (effects of the invention) Since the topping sheet for tires according to the invention is constructed as described above, it is possible to manufacture tires with excellent flatness and high quality by using this topping sheet. . Furthermore, it is possible to omit the process of binding the cords to each other, such as weaving for weft insertion, which helps reduce manufacturing costs.

[Brief explanation of the drawings] Figure 1 is an explanatory diagram of the method for measuring the elongation contraction rate (S).O8o: Sample when fixed under initial load (length tQ)
, S: Sample under initial load after being left for 6 days (length 1.
), a, b: Fixed point, ho: Height of sample when fixed, h,: Height after 6 days of release. Procedural amendment (voluntary) August 15, 1985 Commissioner of the Japan Patent Office Black 1) Mr. Yu Aki 1, Indication of the case 1986 Patent Application No. 141408 2, Name of the invention Tire topping sheet 3, Person making the amendment Relationship to the case Patent applicant name (003) Asahi Kasei Corporation 4, agent address 5-8-10 Toranomon-chome, Minato-ku, Tokyo 105
In column 6 of "Detailed Description of the Invention" of the specification to be amended, "within one hour before topping" in line 5 of page 12 of the statement of contents of the amendment is amended to "immediately before topping."

Claims (1)

[Claims] 1. A topping sheet in which a rubber layer is attached to at least one side of a sheet-like sheet in which a plurality of cords are arranged in parallel without being restrained from each other, and the cords have a release shrinkage rate (S). The ratio of intermediate elongation (E) is 0<S/E≦0.2
A topping sheet for a tire, characterized in that it is the same as No. 5 and uses an adhesive-treated cord.