CZ300661B6 - Synthetic rubber-based rubber compound - Google Patents

Abstract

In the present invention, there is disclosed a synthetic rubber-based rubber compound for the manufacture of shaped parts by vulcanization comprising per 100 parts by weight of butadiene-styrene rubber, 10 to 20 parts by weight of styrene sulfonate stabilizer, 30 to 40 parts by weight of colloidal sulfur and 0.2 to 1 part by weight of a vulcanization accelerator, optionally 5 to 40 parts by weight of granulated cork or cork dust. The rubber compound according to the present invention is continuously processed within a whisking apparatus consisting of a whisking chamber (1) into which the base mixture and compressed air (5) are supplied by a positive-displacement pump (4) through a supply piping (2). A discharge pipe (3) for the processed base mixture and counter-pressure air (8) is connected to the outlet side of the whisking chamber (1).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber composition based on synthetic rubber, in particular for the production of moldings by vulcanization, a process for its preparation and an apparatus for carrying out the process.

BACKGROUND OF THE INVENTION

It is known that rubber blends based on butadiene-styrene rubber have low impact toughness and are relatively hard. Therefore, moldings in which greater flexibility and softness of the material is desired are made of rubber latex. The rubber latex is prepared by reacting synthetic rubber terminated with reactive groups with a crosslinking agent. The thus prepared masterbatch is mechanically whipped and other agents, such as kaolin, are added to the whipped masterbatch to increase toughness.

The parts of the treated compositions have greater softness, but the disadvantage is the increased tensile brittleness and narrow elasticity interval. This greatly limits the variability in the preparation of the composition for different uses. Another significant disadvantage of this method of producing rubber mixtures is the poor controllability of the whipping size and hence the specific weight and the impossibility of continuous processing of the mixture from the beginning up to the casting of the mixture into vulcanization molds.

SUMMARY OF THE INVENTION

The above-mentioned drawbacks are eliminated by a synthetic rubber-based rubber composition, a process for its preparation and an apparatus for carrying out the process according to the invention, comprising 100 parts by weight of butadiene-styrene rubber, 10 to 20 parts by weight of a styrene sulfonate stabilizer, 30 to 40 parts by weight. and 0.2 to 1 part by weight of a vulcanization accelerator. Preferably, 5-40 parts by weight of cork pulp or dust can be added to the mixture.

The invention also relates to a process for the production of a rubber composition according to the invention, which consists in mixing the individual parts of the base mixture and subsequently feeding them continuously to the frothing device together with the compressed air. The foamed mixture is discharged into mixing vessels, where a vulcanization accelerator or filler is added to the mixture at normal temperature and the mixture thus prepared is filled into molds followed by controlled vulcanization. In order to improve the control of the foaming process, it is advantageous that, at the same time as the base mixture and the compressed air, backpressure air is introduced into the foaming device from the opposite side.

In order to achieve the necessary physical properties of the rubber compound treated in this way, it is essential that the apparatus for its manufacture consisting of a frothing chamber and a nav45 positive displacement pump is of interest connected by the feed line of the base mixture. pressure air piping fitted with a pressure regulator. At the outlet side of the foaming chamber, a discharge line of the treated masterbatch is connected. The actual foaming chamber is in the form of a horizontal cylinder formed by a stator in which a rotor mounted coaxially with the stator is mounted on the drive shaft.

The inner circumference of the stator as well as the outer circumference of the rotor are provided with at least two rows of radially arranged pins. The individual rows of pins are arranged on the rotor so as to extend into the gaps between the individual rows of pins arranged on the stator.

For proper operation, it is advantageous that a backpressure air duct fitted with a backpressure regulator is connected to the foaming chamber at the outlet side of the foaming chamber.

- 1 GB 300661-6

The progress achieved by the solution according to the invention consists in that the method of processing the mixture enables its continuous preparation with a wide range of achieved specific weight of the resulting mixture. This makes it possible to process the compositions without increasing the content of various reagents. This is positively reflected in the improvement of the physico-mechanical properties of the finished products. The solution according to the invention achieves higher tensile strength, elasticity and resistance to permanent deformation.

The progress achieved by the solution according to the invention is also characterized in that the products according to the invention are characterized by good cohesion of the basic components and good adhesion to reinforcing materials such as cork, textiles and others.

BRIEF DESCRIPTION OF THE DRAWINGS

An exemplary embodiment of a device for producing a composition according to the invention is shown in the accompanying drawings, in which Figure 1 is a block diagram of a foaming device and Figure 2 is a detail of the internal configuration of a foaming chamber.

DETAILED DESCRIPTION OF THE INVENTION

The following examples serve to illustrate the invention in more detail.

Example 1

Basic composition:

Butadienstyren ................................................. ................... 100 parts by weight

Styrenesulfonate stabilizer, eg SLIPOL® F21 .......... 10 parts by weight

Colloidal sulfur, eg SUPROTEX® SGL ........................... 30 parts by weight

The masterbatch is whipped to a specific gravity of 0.3 g / cm ³ and a vulcanization accelerator such as SUPROGEL® NSC is added in a volume of 0.2 parts by weight. The vulcanization mixture is poured into molds and subsequently vulcanized at 180 ° C.

Example 2

Basic composition:

Butadienstyren ................................................. ................... 100 parts by weight

Styrenesulfonate stabilizer, eg SLIPOL® F21 .......... 10 parts by weight

Colloidal sulfur, eg SUPROTEX® SGL ................................ 30 parts by weight

The masterbatch is whipped to a specific gravity of 0.6 g / cm ³ and a vulcanization accelerator such as SUPROGEL® NSC is added in a volume of 0.4 parts by weight. The vulcanization mixture is poured into molds and subsequently vulcanized at 180 ° C.

Example 3

Basic composition:

Butadienstyren ................................................. ................... 100 parts by weight

Styrenesulfonate stabilizer, eg SLIPOL® F21 .......... 10 parts by weight

Colloidal sulfur, eg SUPROTEX® SGL ............................. 30 parts by weight

Cork powder ................................................ ................... 15 parts by weight

-2GB 300661 B6

The masterbatch is whipped to a specific gravity of 1 g / cm ² and a vulcanization accelerator such as SUPROGEL® NSC is added in a volume of 0.6 parts by weight. The vulcanization mixture is poured into molds and subsequently vulcanized at 180 ° C.

The apparatus for producing the rubber compound according to the above examples consists of a foaming chamber 1 and a displacement pump 4. The displacement pump 4 and the foaming chamber 1 are connected by a supply line 2. On the same side a pressure air supply 5 fitted with a pressure regulator 6 is connected to the foaming chamber. On the opposite side, the foaming chamber 3 is connected to the foaming chamber 3 and the inlet air 8 is provided with a backpressure regulator 7. The foaming chamber 1 is single-chambered and consists of a cylindrical stator 9 in which a rotor 10 coaxially coincides with the stator 9. is mounted on a drive shaft 11 of a drive (not shown). The inner side of the stator 9 and the outer periphery of the rotor 10 are provided with radially arranged mixing elements in the form of a pin 12. The pins 12 are arranged in several rows such that the pins 12 arranged on the rotor 10 are oriented into gaps formed by pins 12 arranged on the rotor. the stator 9 and the head planes of the two sets of pins 12 overlap one another.

The function of the rubber compound manufacturing apparatus according to the present invention is to continuously foaming the masterbatches, the resulting specific weight of the masterbatch after foaming and the dosage amount being continuously variable. At the same time, adjust the required pressure and the quantity of compressed air 5 supplied to the foaming chamber 1 by means of the pressure pump 4. At the outlet side of the foaming chamber 1, set the desired value of the backpressure air 8 via the back pressure regulator 7. it passes through the frothing chamber 1 and is mixed and frothed. The mixing members formed by the pins 12 and arranged on the rotor 10 move in the spaces between the pins 12 arranged on the stator 9 and in close proximity to the inner wall of the stator 9. The pins 12 stir the feed mixture but without substantial shifting in the flow direction. The duct 3 is only supplied by the compressed air supply 5. By means of the rotary movement and the action of the pins 12, a perfectly homogeneous mixture and its intensive whipping are obtained. At the moment of equalization of the pressure in the foaming chamber 1 and the value of the back pressure, the foamed paste starts to flow out through the discharge line 3. The desired specific gravity of the basic mixture after foaming is achieved by changing the pressure and amount of compressed air supplied 5.

Industrial applicability

The solution according to the invention can be used in the production of shaped parts for various branches of the processing industry. It is widely used in the manufacture of shoemaking components, damping and sealing elements for the mechanical engineering industry.

Claims (6)

CLAIMS 1. Synthetic rubber-based rubber composition, in particular for the production of moldings by vulcanization comprising butadiene-styrene rubber, optionally further components and a stabilizer, comprising 50 parts by weight of butadiene-styrene rubber, 10 to 20 parts by weight of a styrene sulfonate stabilizer. up to 40 parts by weight of colloidal sulfur and 0.2 to 1 part by weight of a vulcanization accelerator. Synthetic rubber-based rubber composition according to claim 1, characterized by 55, further comprising 5 to 40 parts by weight of cork pulp or dust. -3 CZ 300661 B6 A process for producing a synthetic rubber-based rubber composition according to claim 1 or claim 2, characterized in that the individual parts of the masterbatch are mixed and then continuously fed to the frothing device together with the compressed air and the foamed blend. is being diverted 5 into mixing containers, where a vulcanization accelerator or filler is added to the mixture at normal temperature, and the mixture thus prepared is poured into molds and subjected to controlled vulcanization. 4. A process for the production of a synthetic rubber-based rubber composition according to claim 3, characterized in that, at the same time as the base mixture and the compressed air, backpressure air is supplied to the foaming and pressure equipment. An apparatus for producing a rubber composition according to claim 1 or claim 2 and a process as recited in claim 3 or claim 4 and comprising a foaming chamber and a positive displacement pump connected to each other by a masterbatch feed line, characterized in that 15, a compressed air line (5) fitted with a pressure regulator (6) and a discharge line (3) of the processed mixture on its outlet side are connected to the chamber (1) by the base mixture supply line (2), the foaming chamber (1) having the shape a horizontal cylinder formed by a stator (9), in which a rotor (10) mounted on the drive shaft (11) is arranged coaxially with the stator (9), the inner circumference of the stator (9) and the outer circumference of the rotor (10) being provided with at least 20 with two rows of radially arranged pins (12) axially displaced so that the pins arranged on the rotor (10) extend into the gaps between the individual rows of pins arranged on the stator (9). 6. An apparatus for producing a rubber composition as claimed in claim 5, wherein: On the outlet side of the foaming chamber (1), a backpressure air duct (8) fitted with a back pressure regulator (7) is connected to the foaming chamber (1).