JPS5952635A - Shortening method of vulcanizing time of rubber article - Google Patents

Abstract

PURPOSE:To shorten the vulcanizing time of a rubber article or the like while using a conventional quantity of a conventional vulcanization accelerator, by a method wherein a vulcanization accelerator is maintained in an atmosphere of a predetermined humidity and a predetermined temperture for a predetermined period of time before being kneaded into a blended rubber. CONSTITUTION:A fan 7 is fitted to a lower side of a conveyor 2, an upper- lower pair of heaters 8, 9 are provided on the lower side of the fan 7, the lower heater 9 is immersed in water 10, water vapor generated by the heaters is forcibly fed upward by the fan 7, and the vulcanization accelerator 11 being conveyed on the conveyor 2 is heated and moistened at a relative humidity of 0- 100% and a temperature of 20-200 deg.C. After completing the moist heat treatment, the vulcanization accelerator decomposed is discharged into a container 13, and is fed to a kneading step. The quantity of the vulcanization accelerator decomposed by the moist heat treatment can be made to be constant, and the quantity is controlled between summer and winter.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a method of reducing the vulcanization time of rubber articles.

Conventionally, vulcanization accelerators have been widely used to accelerate the vulcanization reaction of compounded rubber. The vulcanization accelerator decomposes in the compounded rubber and accelerates the vulcanization reaction. Generally, the vulcanization reaction progresses quickly, and the vulcanization time is shortened accordingly, which improves productivity. To increase the vulcanization speed of compounded rubber, increase the amount of vulcanizing agent in compounded rubber, change the type of vulcanization accelerator (fast-acting vulcanization accelerator, slow-acting vulcanization accelerator), etc. Although it is conceivable to mix two or more types, this method has problems such as high cost due to an increase in the amount of vulcanization accelerator combined, and a low cost rate and high cost due to an increase in the brands of vulcanization accelerators used. Therefore, there is a limit to increasing the amount of vulcanization accelerator and the like.

This invention uses a conventionally used vulcanization accelerator,
Another object of the present invention is to provide a method for shortening the vulcanization time of a nidistomer or rubber article, which can shorten the vulcanization time while maintaining the same amount of compounding as before.

The outline of the method of the present invention is that before kneading the vulcanization accelerator into the compounded rubber, it is kept in a predetermined humidity and an ambient atmosphere for a predetermined period of time. As the agent, N-cyclohexyl-2-benzothiazolyl sulfenamide, 2-mercaptobenzothiazole, tetramethylthiuram disulfide, N-7 tylacandehyde aniline, N,N-diphenylthiourea, 1.3 -diphenylguanidi 7, etc., but are not limited to these. When this vulcanization accelerator is decomposed in advance under moist heat conditions and then kneaded into this compounded rubber, it immediately reacts with the accelerator (zinc white) in the compounded rubber to form Zn chloride flakes. This causes the ring-opening of sulfur molecules, and as a result, the sulfur becomes ready to bond (crosslink) with the carbon atoms in the compounded rubber under heating (vulcanization process). Therefore, this state is called vulcanization. Since the product 1 has already been formed at the beginning of the process, the crosslinking reaction is immediately scorched when the vulcanization process begins, and the vulcanization time is shortened accordingly. However, in the conventional method,
The vulcanization accelerator enters the vulcanization stage in the compounded rubber and rises to 1.
Vulcanization is promoted by full-fledged V-decomposition and vulcanization.

The above-mentioned moist heat environment is, for example, as shown in principle in Fig. 1, a moist heat device consisting of an oven 1 whose temperature and humidity are controlled, and a belt conveyor 2 that passes through the oven 1' and leads to, for example, a kneading process. Use. In this case, a temperature measurement section 3 and a temperature measurement section 4 are attached to the upper stage of the conveyor 2t, and these are electrically connected to a heat and humidity recording section 5 and a heat and humidity control section 6. A fan 7 is installed on the lower stage of the conveyor 2, and heaters 8 and 9 are installed on the lower stage of the fan 7. The lower heater 9 is submerged in water 10, and the water taste generated by the heater is removed. The vulcanization accelerator 11 that is forcibly sent in the F direction by the fan 7 and transferred on the conveyor 2 is heated and humidified and then circulated through the duct 12. Humidity is between 0 and 100°C, and temperature is generally between 20 and 200°C. still,
The liquid vulcanization accelerator is placed in a container and transported on a conveyor F. The operation steps of the heat and humidity control by the heat and humidity control section 6 are summarized as follows.

Settings were made using the control unit 6 using the principle of a psychrometric thermometer. The heaters 8 and 9 operate so that the dry bulb temperature and wet bulb temperature become equal to the temperatures measured in steps 3 and 4.

For example, if the temperature of the temperature measuring section 5 is lower than the setting, the heater 8 is activated, and if the humidity of the II+11 humidity section 4 is lower than the setting, the heater 9 is activated.

The decomposed vulcanization accelerator that has been subjected to the moist heat treatment is stored in container 15.
The humidity and temperature are controlled at each location and transferred to the kneading process. By keeping the vulcanization accelerator in a humid atmosphere for a certain period of time, it is possible to keep the vulcanization accelerator component 1!1 vffi constant. For example, by controlling the amount of decomposition in the summer and increasing the amount in the winter, the difference in vulcanization time between summer and winter can be made for the same type and amount of vulcanization accelerator. Vulcanization will be faster by kneading 847214 start-up accelerator/quick-acting accelerator than by kneading, for example, 10% of vulcanization accelerator into hard rubber, so mix the slow-acting accelerator by 20% before kneading. If left to stand, there is no need to knead the quick-acting accelerator.Therefore, according to the method of the present invention, it is possible to save the amount used, reduce the number of brands used, and save labor.

In addition, after adjusting the moisture content by leaving the vulcanization accelerator in a room filled with water in the acid part for a certain period of time so that the moisture content of the vulcanization accelerator is 0 to 6.0%, CM Chini 20C
It is also possible to decompose the vulcanization accelerator by heating in a preheated oven of known construction to ~200C. Moisture content can be measured by the Karl-Huischer method.

Next, examples and comparative examples of the present invention will be shown.

Additive (ILTC) Accelerator N-cyclohexyl-2-benzothiazolyl sulfenamide +? The compounded rubber composition shown in Table 1 was kneaded in a Banbury mixer to obtain compounded rubber composition A.Also, the same vulcanization accelerator was immediately mixed with water after adjusting the moisture content so that the moisture content was in the 3 range. It was decomposed by heating in a preheated oven at ℃ for 5 hours and kneaded into the compounded rubber shown in Table 1 to obtain compounded rubber composition B.On the other hand, the same vulcanization accelerator was subjected to heat treatment in advance. The mixture was kneaded into the compounded rubber shown in Table 1 to obtain a compounded rubber composition C.

” 1 Compounded rubber composition A + 'B + and C by JSR
-C vulcanization using a type Curalastometer (standard conditions, sample size 42g my +
Scorch Time). The results are shown in Table 2.
It can be seen that the vulcanization rate of those subjected to moist heat treatment is 20 times faster than those not subjected to moist heat treatment, and therefore the vulcanization time is significantly shortened.

Example L relates to tires, but also includes rubber hoses, rubber belts, and fenders.

It can be carried out in the production of rubber articles such as rubber mats.

``As mentioned above, when using this invention, the vulcanization accelerator can be treated with a single layer of moist heat before kneading.'' (!) The vulcanization reaction can be accelerated and the vulcanization time can be shortened. The operational efficiency of expensive vulcanization equipment can be improved, and the use of vulcanization accelerators can be reduced.

[Brief explanation of drawings]

The figure is a schematic configuration diagram showing an example of a moist heat treatment apparatus used in the method of the present invention. 1... Oven, 2... Belt conveyor, 5...
1llll IFin section, 4...Humidity measurement section, 5...Moisture heat recording section, 6...Moisture heat control section, 7...Fan, 8.9
...Heater, 10...Water, 11...Vulcanization accelerator, 12-...Duct, 13...Container patent issued - 1 person Sumitomo Rubber Industries, Ltd.]] 1-Series 15 Ne city j ] Ni 1 ■, Indication of minor matters 1982 Patent Application No. 162792, No. 2, Name of the invention Method for shortening vulcanization time of rubber articles I3 3. Person making the amendment Relationship with I11 44j Applicant 4, Order for amendment No. 1” Jin 1 (spontaneous) 5. 1. Detailed explanation of the invention in the specification subject to amendment. 6. Contents and Procedures for Amendments Sode Tadashi p) (Method) 1. Indication of the case Patent Application No. 362792 of 1982 2. Name of the invention Method for shortening the vulcanization time of rubber articles 6. Person making the amendment Relationship with the case Patent applicant January 25, 1981 (shipment date) 5. Name of the invention in the subject application and specification column 6. Contents of the sleeve correction [+1*fi document as attached. (2) In the title of the invention column of the specification, the statement ``Method for shortening the vulcanization time of rubber products'' was replaced with ``Method for shortening the vulcanization time of rubber articles 17''.
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Claims (1)

[Claims] (1) In the manufacturing process of rubber articles, before kneading the vulcanization accelerator in the compound comb, the vulcanization time of rubber articles is characterized by keeping the vulcanization accelerator in a P atmosphere at a predetermined humidity and temperature for a predetermined period of time. shortening method.