KR20020038052A - Composition of epdm and polypropylene - Google Patents

Abstract

PURPOSE: Provided is a composition of ethylene-propylene-diene-monomer(EPDM) and polypropylene, which is excellent in properties and contains waste EPDM, therefore, it can reduce the cost and is good for environment. CONSTITUTION: The composition of the EPDM and the polypropylene comprises raw EPDM, polypropylene, an additive, and an oil, wherein the weight ratio of the raw EPDM and the polypropylene is 2:1-3:1. The composition contains additionally 1-40wt%(based on raw EPDM) of waste EPDM powder having a particle size of 5-30 micrometer.

Description

Ethylene propylene diene terpolymer and polypropylene composition {COMPOSITION OF EPDM AND POLYPROPYLENE}

The present invention relates to a composition consisting of ethylene propylene diene terpolymer (ethylen-propylene-dinen-monomer, hereinafter referred to as "EPDM") and polypropylene. More particularly, it relates to a recyclable composition consisting of EPDM and / or waste EPDM powder and polypropylene.

Recently, the amount of waste rubber caused by the development of the automobile industry has been rapidly increased, so the problem of disposal of waste rubber has been raised socially. However, the current technology for treating waste rubber has been caused by incineration and landfill, and environmental problems are serious. Therefore, the best way to solve the environmental problems caused by incineration and landfill by recycling the waste rubber is to suffer from economic problems and poor technology development.

There has been a blending method for preparing a mixture until now, but when forming the material by the conventional blending method, the formation of flow marks and mechanical strength on the surface of the molded part due to incomplete mixing, uncrosslinking, difficulty in establishing proper processing conditions, etc. Due to the deterioration of the actual situation is difficult to follow.

Therefore, in view of this point, the present invention solves problems of conventional products by changing the proportion of materials such as EPDM, polypropylene, and additives, and develops more advanced products. In addition, waste EPDM was added to the raw EPDM to suggest a method for waste rubber treatment that is a social problem in the environment.

1 is a view showing the structure of the waste EPDM / EPDM / polypropylene.

2 is a diagram showing the tensile strength and elongation at break of samples prepared at various screw speeds.

3 is a view showing the hardness and specific gravity of samples prepared at various screw speeds.

In the present invention, EPDM and polypropylene are added to a mixer or banbury mixer, and additives and oil are added to carry out compounding. At this time, the ratio of EPDM and polypropylene is 2: 1 to 3: 1 by weight, and 1-40 wt% of waste EPDM was added to the raw EPDM. The used waste EPDM is in powder form and has a particle size of 5 to 30 µm. The waste EPDM powder is already crosslinked. The distribution of each component in the mixture is shown in FIG. 1. EPDM and waste EPDM particles are distributed in the molten polypropylene, have elasticity of rubber at room temperature, and have thermoplastic properties during processing.

Hereinafter, the present invention will be described in detail with reference to the following examples.

Example 1

1. Manufacture

The internal mixer was operated after setting the conditions at 170 to 220 ° C. and 30 to 50 rpm. EPDM was added to the internal mixer, and after 2-4 minutes, polypropylene (mp: 165 ° C.) was added, followed by a filler. Then oil was added, a curing agent was added and a curing accelerator was added. The amount of each component is shown in the following table.

ingredient Usage (phr) EPDM 100-200 Polypropylene 50-100 Curing agent (phenolic resin: SP-1045) 2 to 8 Curing accelerator (SnCl ₂ ㆍ 2H ₂ O) 1 to 5

Polypropylene is generally used in olefin polymer blends, and polypropylene is rarely used. The reason is that polypropylene is a crystalline resin having a relatively high melting point in general purpose resins, and has chemical resistance, electrical insulation, and mechanical strength. And heat resistance is superior to other general-purpose resins.

After mixing with an internal mixer, screw speeds of 30, 50, 70, and 90 at a cylinder temperature (190-210 ° C) were used with a single screw extruder (Dongjin Machinery Co., Ltd., screw diameter: 30 °, L / D: 25). Extrusion tests were carried out with varying rpms and made into pellets after cooling.

2. Manufacture of Specimen

The extruded material was used as a press press (Wonil press co., Ltd.), the temperature of the first and second zones of the nozzle and the heater was 200 ℃, 195 ℃, 190 ℃, respectively, the pressure was 144 bar It was. Specimens were produced by injection into a mold made to the ASTM D 1708 standard, and used after leaving in a constant temperature and humidity room for 48 hours.

3. Test method

In the measurement of basic physical properties, the tensile test was performed four times using a universal test machine (LLOYD INSTRUMENTS, LR10K) using a tensile speed of 500 mm / min and a load cell of 10 kN. Tensile strength and elongation at break were determined, and hardness was used as the spring type (shore A) by KSM 6518 vulcanized rubber physical test method.

4. Mechanical characteristics

Table 2 shows the results of the tensile test, elongation, hardness and specific gravity test to determine the mechanical properties of the prepared specimen.

Physical Properties of EPDM / Polypropylene Compositions characteristic unit Screw speed 30 rpm 50 rpm 70 rpm 90 rpm Hardness Shore a 71 71 72 73.8 importance - 0.96 0.97 1.00 0.99 The tensile strength kg _f / cm ² 69 71 71 58 Elongation % 367.5 403.7 322.3 281.1

Example 2

Table 3 shows the results of tensile test, elongation, hardness and specific gravity test of the prepared specimens, which were carried out in the same manner as in Example 1 except that EPDM and waste EPDM were used instead of EPDM.

Physical Properties of EPDM / Waste EDPM / Polypropylene Compositions characteristic unit Screw speed 50 rpm 70 rpm Hardness Shore a 79 81 importance - 1.3 1.4 The tensile strength kg _f / cm ² 50 46 Elongation % 190 180

The present invention will bring vitality to the poor rubber industry through the localization of thermoplastic rubber, which has been dependent on imports. It is urgent to develop parts in consideration of environmental problems of rubber products used as automobile parts, and to recycle the scraps generated during molding by reusing blends with EPDM and polypropylene and to reuse the waste rubber. In addition, it is expected to have a significant effect on cost reduction and securing national competitiveness by reducing imports of raw materials.

Claims (4)

Composition consisting of raw EPDM, polypropylene, additives and oils. The composition according to claim 1, wherein the ratio of the raw EPDM and the polypropylene is from 2: 1 to 3: 1 by weight. The composition according to claim 1, wherein 1-40% by weight of waste EPDM is added to the raw EPDM. The composition of claim 3, wherein the waste EPDM is 5-30 μm in size in powder form.