JP2936348B2 - Kneading method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a kneading method for increasing viscosity reduction efficiency and improving productivity without reducing physical properties of raw rubber.

[Conventional technology]

Conventionally, a kneading method of kneading the kneaded rubber discharged from the closed-type mixer with an undermixer is generally performed.In the case of this kneading method, the released high-temperature rubber is put into an undermixer, The mixture is returned to the closed mixer to perform kneading.

[Problems to be solved by the invention]

However, since the high-temperature rubber is not actively cooled even after it is directly introduced into the undermixer, the efficiency of lowering the viscosity of the rubber in the undermixer is low, and as a result, the closed type is used to obtain the initial processability. Preparation work such as extending the kneading time in the mixer, increasing the number of passes, adding a peptizer, and further narrowing the cap of the roll is required, and also has a negative effect on the physical properties of the rubber. There was a problem.

[Object of the invention]

The present invention has been devised in view of such conventional problems, without increasing the physical properties of the raw rubber due to heat or peptizing agent, increasing the viscosity reduction efficiency, and maintaining the dispersibility while maintaining the mixing productivity. It is an object of the present invention to provide a kneading method capable of improving the kneading.

[Means for solving the problem]

In order to achieve the above object, the present invention, when kneading rubber discharged from the closed type mixer, is repeatedly kneaded while passing through a cooling device and a roll, at least cool the roll input temperature of the kneaded rubber to 90 ℃ or less. The main point is to repeatedly perform the kneading.

[Function of the invention]

The present invention is configured as described above, the rubber discharged from the under mixer is formed into a pellet or a sheet, and a cooling device for reducing the temperature to 90 ° C. or less, preferably 80 ° C. or less is provided in front of the roll, and kneading is performed. By always setting the temperature of the roll of rubber to 90 ° C or less, the viscosity reduction efficiency can be increased without lowering the physical properties of the raw rubber, and the mixing productivity can be improved while maintaining the dispersibility. is there.

(Example of the invention)

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic explanatory view of a kneading roll system showing a first embodiment of the present invention, wherein 1 is a closed type mixer, 2 is an undermixer, and this undermixer 2 has
A plurality of sets of pass trains 5 each composed of a cooling device 3 and a roll 4 are arranged in series, and the number of roll passes is maintained at the conventional number of passes to prevent the dispersibility from deteriorating. , Always below 90 ° C, preferably below 80 ° C, 40 ° C
After being cooled by the cooling device 3 attached to the undermixer 2 as described above, it is put into the roll 4.

At temperatures other than the above (40 ° C or lower, 90 ° C or higher),
Since a mechanical problem occurs, the rubber is charged into the roll 4 while maintaining the above temperature. That is, as is clear from the graph of FIG. 3 showing the amount of viscosity decrease per constant number of rotations of the roll, the relationship between the amount of viscosity decrease and the rubber temperature at the time of injection is as follows.
If the temperature at the time of the roll input is 90 ° C. or higher, the efficiency of viscosity reduction is significantly reduced.In order to effectively increase the viscosity reduction efficiency, the roll input temperature of the kneaded rubber must be 90 ° C.
It is necessary to use at a temperature of 80 ° C. or less, and preferably at 80 ° C. or less.

On the other hand, as is clear from the graph of FIG. 4 showing the relationship between the rolling force and the rubber temperature, when the rubber temperature at the time of charging becomes 90 ° C. or less, the rolling force of the kneading rolls starts to increase rapidly,
If the temperature is lower than 40 ° C., the strength of the roll approaches, and the work becomes impossible.

Therefore, in order to increase the efficiency of lowering the viscosity of the rubber within the range of the strength capability of the roll, it is necessary to control the rubber temperature at the time of charging the roll to 40 ° C. or more and 90 ° C. or less.

Further, the cooled rubber W cooled by the cooling device 3 keeps the viscosity reduction efficiency by passing through the roll 4 several times without being wound around the roll 4, and furthermore, the roll 4 is limited to the same roll. Instead, another roll may be used.

The rubber W kneaded after passing through the past train 5 is stacked in a sheet form on the pallet 6 as shown in FIG. 1 and carried out.

FIG. 2 shows a second embodiment of the present invention. In this embodiment, as in the first embodiment, a plurality of past trains 5 each including a cooling device 3 and a roll 4 are arranged in series. This is a method in which rubber is repeatedly kneaded by a set of cooling devices 3a and 3b and a roll 4a. In this case, too, the cooling devices 3a and 3b
The temperature at the time of charging the rubber W is always 90 ° C. or less, preferably
Kneading is repeated at a temperature set at 80 ° C or lower.

Other methods are the same as those in the above-described embodiment, and thus the same reference numerals are given and the description is omitted.

〔The invention's effect〕

The present invention relates to a method for repeatedly kneading the kneaded rubber discharged from the closed mixer as described above while passing the kneaded rubber through a cooling device and a roll. Because of kneading, without deteriorating the physical properties of the raw rubber due to heat or peptizer,
This has the effect of increasing the viscosity lowering efficiency and improving the mixing productivity while maintaining the dispersibility.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of a kneading roll system showing a first embodiment of the present invention, FIG. 2 is a schematic explanatory view of a kneading roll system showing a second embodiment of the present invention, and FIG. FIG. 4 is a graph illustrating the amount of decrease in viscosity per rotation speed, and FIG. 4 is a graph illustrating the relationship between the rolling force and the rubber temperature. DESCRIPTION OF SYMBOLS 1 ... Closed mixer, 2 ... Under mixer, 3 ... Cooling device, 4 ... Roll, 5 ... Paste-lane, W ... Rubber.

Claims (1)

(57) [Claims] 1. A kneaded rubber discharged from a closed type mixer,
In a kneading method of passing through a kneading train of an under mixer equipped with at least one roll and performing kneading, the kneaded rubber discharged from the hermetic mixer is repeatedly kneaded while passing through a cooling device and a roll. A kneading method in which kneading is repeated while cooling at least the roll charging temperature of the kneaded rubber to 90 ° C. or less.