JP2006256060A - Method for holding adhesive force of extrusion member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for holding the adhesive force of an extrusion member which can prevent the lowering of the adhesive force of the extrusion member by passing through a cooling water tank and hold proper adhesive force as the extrusion member of an intermediate material. <P>SOLUTION: In the method for holding the adhesive force of the extrusion member 2 in which the adhesive force of the extrusion member 3 extruded by an extruder 2 is held even after passing through the cooling water tank 30, the cooling water in the tank 30 for cooling the extrusion member 3 is controlled to keep its hardness 25° or below and its sodium ion concentration 150 ppm or below, and the extrusion member 3, when its temperature is at least 90°C, is quenched to 45°C or below by the cooling water. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for maintaining an adhesive force of an extruded member, and more particularly to a method for maintaining an adhesive force of an extruded rubber member that can be widely applied to a tire molded member.

  In the manufacturing process of rubber products such as tires, an adhesive force (tackiness) as an appropriate member is required for each intermediate material mainly for the purpose of eliminating product defects and smoothing molding operations. In order to meet such demand, conventionally, a part of the intermediate member has been dealt with by applying rubber paste to the extruded member. In particular, since the extruded member is extruded at a high temperature, a cooling water tank is always provided, and the adhesive force of the extruded member is reduced by direct contact between the extruded member and water in the cooling water tank. The glue application process was indispensable.

  For example, Patent Document 1 discloses a technique in which an extruded member extruded at a high temperature is transferred to a water-permeable belt provided in water and cooled. Further, Patent Document 2 is a semi-finished product having a high surface adhesion made of rubber or a rubber-like synthetic resin, and a technique for rapidly cooling a hot-finished product that has been calendered or extruded to 0 ° C. or lower. It is disclosed. Furthermore, in Patent Document 3, the extruded rubber extruded by the extruder is sufficiently contracted by applying vibration in the extrusion train, and then the extruded rubber is cooled to thereby contract the extruded rubber member obtained from the extruded rubber. A method and apparatus for reducing the volume is disclosed.

In order to prevent a decrease in the adhesive strength of the extruded member, a rubber paste is conventionally applied to the extrusion line because the high-temperature extruded rubber or the like as described in these patent documents is cooled. An apparatus has been installed, and rubber paste has been applied to the extruded member.
Japanese Patent Laid-Open No. 5-1224034 (Claims etc.) JP-A-6-8308 (Claims etc.) JP-A-8-244090 (Claims etc.)

As described above, since the adhesive strength of the extruded member is reduced by passing through the cooling water tank in the tire manufacturing process, conventionally, rubber paste has been applied to the extruded member. However, due to the nature of the applied rubber paste, the following is applied. A problem has arisen.
(1) The production line is very dirty.
(2) Dirt adheres to the extruded member, and foreign matters are mixed into the product.
(3) Since an organic solvent is used for the rubber paste, attention must be paid to the environment, safety and fire.
Therefore, it has been desired to eliminate the use of rubber paste from the past, and for that purpose, development of a method for suppressing a decrease in the adhesive strength of the extruded member has been desired.

  Accordingly, an object of the present invention is to provide a method for maintaining the adhesive force of an extruded member that can prevent a decrease in the adhesive strength of the extruded member due to passage through a cooling water tank and can maintain an appropriate adhesive force as an extruded member of an intermediate material. is there.

  As a result of intensive studies to solve the above problems, the present inventor has found that the cause of the decrease in the adhesive strength of the extruded member is the generation of metal soap and the precipitation of the chemical compound in the rubber (bloom), and further prevents them. As a result of repeated studies, the present invention has been completed.

That is, the method for maintaining the adhesive force of the extruded member according to the first aspect of the present invention is the method for maintaining the adhesive force of the extruded member that retains the adhesive force of the extruded member extruded by the extruder even after passing through the cooling water tank.
The cooling water (chiller water) in the cooling water tank for cooling the extruded member is controlled to have a hardness of 25 degrees or less and a sodium ion concentration of 150 ppm or less.

Further, the method for maintaining the adhesive force of the extruded member according to the second aspect of the present invention is the method for maintaining the adhesive force of the extruded member that retains the adhesive force of the extruded member extruded by the extruder even after passing through the cooling water tank.
The extruded member is rapidly cooled to 45 ° C. or lower with cooling water in the cooling water tank when the temperature is 90 ° C. or higher.

Furthermore, the method for maintaining the adhesive force of the extruded member according to the third aspect of the present invention is the method for maintaining the adhesive force of the extruded member that holds the adhesive force of the extruded member extruded by the extruder even after passing through the cooling water tank.
The cooling water in the cooling water tank for cooling the extruded member is controlled to have a hardness of 25 degrees or less and a sodium ion concentration of 150 ppm or less,
The extruded member is rapidly cooled to 45 ° C. or lower with cooling water in the cooling water tank when the temperature is 90 ° C. or higher.

  In this invention, it is preferable to manage the pH of the cooling water in the said cooling water tank to 6-7.7.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive force fall of the extrusion member by passage of a cooling water tank can be prevented, and appropriate adhesive force can be hold | maintained as an extrusion member of an intermediate material. Therefore, it can be widely applied to tire forming members and the like.

Hereinafter, embodiments of the present invention will be specifically described.
Hereinafter, a tire extrusion line 1 which is a preferred embodiment according to the present invention shown in FIG. 1 will be described. FIG. 1 is a side view showing a schematic configuration of an apparatus for maintaining the adhesive force of an extruded rubber member 3 according to the present invention. In FIG. 1, an extruder 2 is disposed on the most upstream side of the extrusion line 1, and an extruded rubber member that is a flat unvulcanized rubber from an extrusion die 2a by driving of an extrusion screw (not shown). 3 is extruded continuously.

  The temperature of the extruded rubber member 3 immediately after being extruded is normally 100 to 140 ° C., and the extruder 2 is connected via a belt conveyor 20 constituted by pulleys 21 and 22 and an endless belt 23 and a plurality of rolling rollers 25. To the tow rubber sheet presetting device 10 disposed on the downstream side.

  A cooling water tank 30 is disposed downstream of the tow rubber sheet presetting device 10 after inversion. An aqueous medium 32 is placed in the main body 31 of the cooling water tank 30, and the temperature of the medium 32 is set to a predetermined temperature. It can be set. In the apparatus 10, a toe rubber sheet 11 is laminated on the extruded rubber member 3.

  A belt conveyor 33 is provided in the main body 31, and the belt conveyor 33 includes a pair of pulleys 34 and 35 and an endless belt 36 wound around the pulleys 34 and 35. The pulley 35 is driven by a motor (not shown) to drive an endless belt 36, and conveys the extruded rubber 3 placed on the endless belt 36 to the downstream side. . The extruded rubber member 3 is cooled to a desired temperature while being conveyed through the medium 32. The cooling water tank 30 includes a main body 31, a medium 32, a belt conveyor 33, pulleys 34 and 35, an endless belt 36, and the like.

  Although not shown, a conveyor conveyer is provided on the downstream side of the cooling water tank 30 via a pulley 37 to convey the extruded rubber material 3 to a take-up cart (not shown).

  In the first invention, the cooling water in the cooling water tank 30 of the above-described extrusion line 1 has a hardness of 25 degrees or less, preferably, in order to prevent the formation of metal soap that causes a decrease in the adhesive strength of the extruded rubber member. It is important to control it to 20 degrees or less and a sodium ion concentration of 150 ppm or less, preferably 100 ppm or less. Similarly, from the viewpoint of preventing the formation of metal soap, it is preferable to control the pH of the cooling water to 6 to 7.7. By managing the cooling water in this way, it is possible to suppress the formation of metal soap caused by the combination of alkali metal ions in the cooling water and the rubber compounding chemical of the extruded rubber member.

  In the second invention, the temperature of the extruded rubber member 3 is 90 ° C. or higher, preferably 95 ° C. or higher in order to prevent zinc stearate from precipitating from the rubber compounding chemical of the extruded rubber member 3 on the member surface. In some cases, it is important to rapidly cool to 45 ° C. or lower with cooling water. Therefore, in order to be able to convey the extruded rubber member 3 to the cooling water tank 30 before the extruded rubber member 3 becomes 90 ° C. or lower, it is necessary to design the position of the cooling water tank 30 as shown in FIG. That is, in the conventional extrusion line shown in FIG. 2, the rubber paste applying device 40 is installed on the line, and after passing through the rubber paste applying device 40, the extruded rubber member 3 is conveyed to the cooling water tank 30. In the second invention, as shown in FIG. 1, the extruded rubber member 3 is conveyed directly from the extruder 2 to the cooling water tank 30 without going through the rubber paste applying device 40, and the distance from the extruder 2 to the cooling water tank 30. Need to be shortened.

  The third invention is a combination of the first invention and the second invention, and can simultaneously prevent formation of metal soap and prevention of precipitation of zinc stearate on the member surface. This is more effective for maintaining the adhesive strength of the rubber member 3.

Hereinafter, the present invention will be specifically described based on examples.
The adhesive strength of the extruded rubber member was evaluated by the following adhesive strength test 1 and adhesive strength test 2.
Adhesion test 1
As an extrusion condition, an extruded rubber member for a tire was extruded from the extruder 2 and conveyed directly from the extruder to the cooling water tank 30 without passing through a rubber paste applicator as shown in FIG. At this time, the adhesive strength of the extruded rubber member 3 was evaluated when both the hardness of the cooling water and the sodium ion concentration in the cooling water tank 30 were varied. For the evaluation, a tack meter (Pikuma) was used. FIG. 3 shows the relationship between the hardness and sodium ion concentration of the obtained cooling water and the adhesive strength of the extruded rubber member.

Adhesion test 2
In the extrusion line 1 shown in FIG. 2, when the extruded rubber member 3 is conveyed from the extruder 2 to the cooling water tank 30 and rapidly cooled to 45 ° C. or less, the sampling positions shown in Table 1 below from the extruder 2 to the cooling water tank 30 are shown. Were sampled, and the member temperature and adhesive strength at the position were evaluated, and the presence or absence of folding of zinc stearate after rapid cooling was evaluated. The obtained results are also shown in Table 1 below. For reference, the extruded rubber member 3 extruded from the extruder 2 by applying a rubber paste with the rubber paste applying device 40 and then transported to the cooling water tank 30 is also used as a reference example. The same evaluation was performed.

  From Table 1 above, it can be seen that if the temperature of the extruded member is 95 ° C. or higher, precipitation of zinc stearate can be suppressed by rapid cooling, and adhesive strength can be secured at a level of 450 g or higher. In addition, although the water temperature of cooling water was performed at 9 degreeC and 27 degreeC, the difference did not arise in a result.

It is a schematic diagram of the extrusion line for tires concerning one embodiment of the present invention. It is a schematic diagram of the conventional extrusion line for tires. It is a graph which shows the relationship between the hardness of a cooling water, a sodium ion concentration, and the adhesive force of an extrusion rubber member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Extrusion line 2 Extruder 3 Extruded rubber member 10 Toe rubber sheet preset apparatus 11 Toe rubber sheet 21, 22 Pulley 23 Endless belt 30 Cooling water tank 31 Cooling water tank main body 32 Water medium 33 Belt conveyors 34, 35, 37 Pulley 36 Endless belt 40 Rubber glue applicator

Claims (5)

In the method for maintaining the adhesive force of the extruded member that retains the adhesive force of the extruded member extruded by the extruder even after passing through the cooling water tank,
A method for maintaining the adhesive strength of an extruded member, wherein the cooling water in the cooling water tank for cooling the extruded member is controlled to have a hardness of 25 degrees or less and a sodium ion concentration of 150 ppm or less.   The method for maintaining an adhesive force of an extruded member according to claim 1, wherein the pH of the cooling water is controlled to 6 to 7.7. In the method for maintaining the adhesive force of the extruded member that retains the adhesive force of the extruded member extruded by the extruder even after passing through the cooling water tank,
A method for maintaining the adhesive strength of an extruded member, wherein the extruded member is rapidly cooled to 45 ° C. or lower with cooling water in the cooling water tank when the temperature is 90 ° C. or higher. In the method for maintaining the adhesive force of the extruded member that retains the adhesive force of the extruded member extruded by the extruder even after passing through the cooling water tank,
Managing the cooling water in the cooling water tank for cooling the extruded member to a hardness of 25 degrees or less and a sodium ion concentration of 150 ppm or less, and
A method for maintaining the adhesive force of an extruded member, wherein the extruded member is rapidly cooled to 45 ° C. with cooling water in the cooling water tank when the temperature is 90 ° C. or higher.   The method for maintaining the adhesive force of the extruded member according to claim 4, wherein the pH of the cooling water is controlled to 6 to 7.7.

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