JPS5838145A - Method of molding tire - Google Patents

Abstract

PURPOSE:To mold efficiently a tire, by applying the surfaces of a turnup bladder and a drum bladder of a tire molder with an organic halogen compound that can prevent unvulcanized rubber that will be vulcanized on said surfaces from adhering on said surfaces. CONSTITUTION:The surfaces of the drum bladder, the turnup bladder and an expand drum cover attached to the tire molder are coated with an organic halogen compound (e.g. N-bromosuccimide, trichloroisocyanuric acid, diisocynuric acid and dichlorodimethylhydatoin). Thus the unvulcanized rubber is prevented from adhering to the accessories of the tire molder, and deformation or failure of joining of the rubber would not occur.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for molding a tire, and more specifically, the present invention relates to a method for molding a tire, and more specifically to a drum plader, turn-up plader, or extended drum cover (hereinafter collectively referred to as these) made of vulcanized rubber attached to a tire molding machine. In order to prevent adhesion between the bladder (referred to as a bladder) and unvulcanized rubber for tires, an organic halogen compound having a 10-N- (X is halogen) bond in the molecule is coated on the surface of the bladder. This invention relates to a method for forming tires.

Conventionally, to prevent adhesion between the vulcanized rubber bladder and the unvulcanized rubber used for tire molding, a powder or liquid mold release agent such as zinc stearate, paraffin, or surfactant was applied to the bladder surface. Although it is customary to do so, it required reapplication each time the tire was molded or after several molds. Furthermore, since these mold release agents adhere to unvulcanized rubber for tires, they have the disadvantage that, depending on the type and application amount of the mold release agent, the quality of the tire may be degraded.

As a way to solve this problem,
No. 0 discloses a method for obtaining a bladder with good mold release durability by providing a silicone rubber layer on the bladder surface, but in this case, the mold release durability from unvulcanized rubber is improved. However, because there is no technology to achieve sufficient adhesion between the bladder made of vulcanized rubber and the silicone rubber layer, the bladder may be prematurely destroyed due to peeling from the adhesive surface, making it difficult to obtain sufficient durability for practical use. There are no drawbacks. As a method to improve this early failure of the bladder, Utility Model Application No. 56-41629 proposes a method of making the entire bladder from silicone rubber, but in this case, silicone rubber inherently lacks the rubber strength. Therefore, it still has the disadvantage that the bladder breaks down prematurely.

As described above, a method for effectively preventing adhesion between a bladder made of vulcanized rubber and unvulcanized tire rubber, which is a problem in tire molding methods using tire molding machines, has not yet been found.

The present invention prevents adhesion between unvulcanized rubber for tires and drum bladders, turn-up bladders, or extended drum covers, which has been a problem in the past in tire molding methods using tire molding machines, and also prevents mold release. The purpose of the present invention is to provide a tire molding method with improved durability.

X is halogen).

That is, the present invention provides a method for molding a tire using a tire molding machine, by applying a gene compound in the molecule to the surface of a drum bladder, turnup bladder, or extend drum cover attached to the tire molding machine. This is a tire molding method characterized by preventing adhesion with unvulcanized rubber for tires.

The organic halogen compound used in the present invention is necessary from the viewpoint of preventing molecules from sticking to unvulcanized rubber. Examples include halogenated incyanuric acid such as halogenated incyanuric acid, halogenated hydatoin such as dichlorodimethylhydantoin, and halogenated incyanuric acid is particularly preferred.

The amount of this tvaa halogen compound applied to the bladder surface has a non-adhesive effect even in a very small amount, but it is preferably 3 to 1.
5 ji/m"; if too small a quantity, the non-adhesive effect will be poor, and even if a large quantity is applied, the coating effect will not improve any further and the rubber will harden, reducing the flex fatigue resistance and shortening the life of the bladder. This is not desirable because it causes

The organic halogen compound is applied to the bladder surface as a solution in a solvent that does not react with it. Solvents include aromatic hydrocarbons such as benzene and xylene, ethers such as diethyl ether, dioxane and tetrahydrofuran, esters such as ethyl acetate, ketones such as methyl ethyl ketone and hiscyclohexanone, ethyl chloride, At least one solvent that does not react with organic compounds such as chlorinated hydrocarbons such as chloroform and carbon tetrachloride, and tertiary alcohols such as tertiary butyl alcohol is appropriately used. The concentration of the organic halogen compound in the solution varies depending on the solubility in the solvent and the boiling point of the solvent, but generally, a concentration of 0.1 to 2.0% by weight, preferably 05 to 10% by weight, effectively provides the non-adhesive effect of the bladder. Improve.

If the concentration is too low, the working efficiency will be poor, and if the concentration is too high, the reaction between the organic halogen compound and the bladder rubber will not be completed before the solvent dries.

A solution of the organic halogen compound is applied to the bladder surface by dipping, brushing, or spraying, and while the solvent dries, the organic halogen compound reacts with the double bond portion of the vulcanized rubber that makes up the bladder. to make the surface non-adhesive. Therefore, the polymer used for bladder rubber must contain at least 5 parts by weight of a polymer having double bonds in the molecule, based on 100 parts by weight of the polymer.
Examples of such polymers include natural rubber, synthetic polyisoprene rubber, styrene-butadiene rubber, polybutadiene rubber, chloroprene rubber, nitrile-butadiene rubber, and ethylene-propylene-diene terpolymer rubber.

Next, the tire molding process using the tire molding machine used in the present invention will be briefly explained with reference to the drawings.

Tires are broadly classified into radial tires and bias tires based on their structure, and the tire molding machines are also different for each type. FIG. 1 is a cross-sectional view of the upper half from the center of a typical radial tire molding machine, in which 1 is a drum bladder and 12 is a turn-up bladder, each of which is made of vulcanized rubber. In the bias tire molding machine, the drum bladder 1 is made of metal, or a rubber cover is attached to a divided drum made of metal. The in-tip plug 2 is made of vulcanized rubber like the radial tire molding machine.

First, an inner liner rubber layer 3 in the form of a thin rubber sheet is applied onto the drum bladder 1, and then a carcass rubber layer 4 is applied. Next, the drum bladder 1 is inflated as shown in FIG. 2, and at the same time the bead 5 is joined.

Next, the turn-up bladder 2 is inflated and the end of the carcass rubber layer 4 is folded back so as to wrap around the bead 5. Thereafter, the turn-up bladder 2 is retracted and returns to the state shown in FIG.

Drum bladder still inflated
On top of the carcass rubber layer 4 on top of the carcass rubber layer 1, layers of belt rubber, trend rubber, and side rubber (not shown) are further applied.Finally, the drum bladder 1 is left in a contracted state and the unvulcanized tire is transferred to the molding machine. removed from the list.

During this series of steps, when the turn nap bladder 2 shrinks after folding the carcass, or after the completion of molding, the drum bladder 1 is used to remove the unvulcanized tire from the molding machine.
When the tire shrinks, conventionally, the Prada and the unvulcanized tire rubber have adhered to each other and come off poorly, causing deformation and poor bonding, which significantly impedes workability. Also, in extreme cases, it will be scrapped at this stage. However, in the present invention, as described above, this problem is solved by applying a solution of an organic halogen compound to the Prada surface.

The present invention will be specifically described below based on Examples and Comparative Examples.

Examples 1 to 4 and Comparative Examples 1 to 3 In a radial tire molding machine of 165 SR13 size, 0 to 0 to 50 g of each treatment solution of a 5% by weight solution of trichloroisocyanuric acid in ethyl acetate, a 5% by weight solution of oleic acid in isopropyl alcohol, and a 3% by weight suspension of zinc stearate in ethyl alcohol was applied using a nozzle. Thereafter, the surface of the drum plader was air-dried for 50 minutes to dry the solvent and a tire was molded. Table 2 shows the results of visual inspection of the effectiveness of the application effect and the durability of the 9 effects per treatment. The effectiveness of the coating effect was evaluated as (0) if the tire did not deform and could be peeled off smoothly when the drum bladder shrunk after the completion of molding, and (3) if the tire deformed and formed a dense layer.

Furthermore, the durability of the effect per treatment was expressed by the number of times that tire molding could be continuously performed in one application treatment.

At the same time, in order to measure the adhesion between the drum bladder and the inner liner rubber, the rubber compositions shown in Table 1 were mixed with 211
The sheet was vulcanized at 150° C. for 30 minutes) and immersed in each of the above-mentioned treatment solutions for 30 seconds, and then air-dried for 60 minutes to dry the solvent.

This treated vulcanized rubber sheet was layered with a 2111 thick unvulcanized rubber sheet for inner liner, and the weight was 2 kg 7 cm.
After applying a load with a press at 30°C for 120 seconds, it was cut into 1 inch width and tested with a peel tester.
The adhesiveness was examined by peeling at a speed of ,/min. The results are shown in Table 2.

1st coating *1: N, N'-9 queny-p-phenylene diamine, *2 dichlorohexyl benzothiazyl sul 7-enamide \ \ \ As shown in Table 2, Comparative Example 1 in which only ethyl acetate was applied was High adhesion and no application effect at all.

Comparative Examples 2 and 3 in which an oleic acid solution and a zinc stearate solution were applied had low adhesive strength, and although the coating effect was effective, the durability was poor. On the other hand, Examples 1 to 4 in which trichloroin cyanuric acid was applied had low adhesion, good coating effect, and excellent durability.

Examples 5 to 7 and Comparative Examples 4 to 5 In a radial tire molding machine of 185/70 HR14 size, the drum bladder and turn nap bladder made of vulcanized rubber having the composition shown in Table 1 were coated with a third Brush each treatment solution shown in the table to calculate 8,!
Apply an amount of i'/m' and then coat the bladder surface with
The tire was air-dried for 0 minutes to dry the solvent and mold a tire. The effectiveness of the application effect and the durability of the effect per treatment were investigated according to the method of Example 1, and the results are shown in Table 6.

Table 3 From Table 3, when the treatment liquid was applied to the drum bladder and turnup bladder, similar results were obtained. In addition, not only the -trichloroisocyanuric acid solution (Example 5) but also the N-promosuccinimide solution (Example 6) and the diclodimethylhydantoin solution (Example 7) have excellent effectiveness and sustainability of the application effect. I understand that. However, in Comparative Example 4 in which a glycerin solution was applied, the durability of the application effect was poor. This shows that a solution of a branched halogen compound is an excellent treatment solution.

+1 1 As explained above, a solution of an organic halogen compound having a 10-N- bond (X is a halogen) in the molecule is
In the present invention, which is characterized in that the coating is applied to the unvulcanized rubber for tires, it not only provides good mold releasability between the Prada and the unvulcanized rubber for tires over a long period of time, but also re-applies when the anti-adhesive effect decreases. The effect can be easily restored by coating, and since the treatment liquid applied is non-migratory, this is a tire molding method that reduces the quality of the tire.

[Brief explanation of drawings]

flE I Figure i1 This is a cross-sectional view of the upper half of the Nirasial tire molding machine from the center, and Figure 2 is a cross-sectional view showing the drum plader and turn-up plader in Figure 1 in an inflated state. It is. 1 Nidrum Bladder 12: Turnup Bladder, 3:
Inner liner rubber layer, 4: Carcass rubber layer, 5: Bead Patent applicant Yokohama Rubber Co., Ltd. Zeon Kosan Co., Ltd. Agent Patent attorney Tatsuo Ito Tetsuya Ito

Claims (1)

[Claims] In a tire molding method using a tire molding machine, a drum bladder, a turn-up bladder, or an expandable drum attached to the tire molding machine is coated with an organic halogen compound to form an unvulcanized rubber for tires. A tire molding method characterized by preventing adhesion.