KR20030015679A - A thermoplastic of composition comprising polypropylene and ABS having highly-compatibility - Google Patents

Abstract

PURPOSE: Provided is a thermoplastic resin composition produced by adding a compatibilizer to blend of polypropylene and ABS(poly(acrylonitrile-butadiene-styrene)) polymers which are immiscible with each other, wherein the compatibilizer exhibits the compatibility to both of two polymers. CONSTITUTION: The thermoplastic resin composition comprises a polypropylene, a poly(acrylonitrile-butadiene-styrene), and a copolymer of propylene and styrene- acrylonitrile(PP-SAN) which is a copolymer compatibilizer. The content of the copolymer of propylene and styrene-acrylonitrile is 5-10 phr. The copolymer of propylene and styrene-acrylonitrile is a block copolymer having copolymerization degree of 70:30 and number average molecular weight of 50,000-80,000. The content of the polypropylene is 35-60 wt%.

Description

Thermoplastic composition comprising a polypropylene and poly (acrylonitrile-butadiene-styrene) polymer exhibiting excellent compatibility {A thermoplastic of composition comprising polypropylene and ABS having highly-compatibility}

FIELD OF THE INVENTION The present invention relates to thermoplastic resin compositions comprising polypropylene and poly (acrylonitrile-butadiene-styrene) polymers, and more particularly to polypropylene and poly (acrylonitrile-butadiene-styrene) as compatibilizers. And it relates to a thermoplastic resin composition containing a copolymer of poly (styrene-acrylonitrile) in a certain amount, the thermoplastic resin composition of the present invention prevents the deterioration of mechanical properties due to incompatibility when mixing the conventional polymer and between each composition The mechanical properties are greatly improved by increasing the compatibility, which makes it particularly suitable for automobile parts manufacturing.

Recently, as environmental regulations are strengthened around the world, the use of polymer materials is increasing rapidly as automobiles are lighter in weight for the purpose of improving fuel efficiency and reducing emissions of automobiles.

Most of the materials used in automobiles are made of polymers, and the proportion of each polymer is different for each vehicle type, but polypropylene and poly (acrylonitrile-butadiene-styrene) (hereinafter referred to as "ABS") are mainly used. . The polymers usually exceed 80% by mass.

Currently, the population of automobiles is increasing exponentially, new models of cars are produced every year, and the number of scrapped cars is increasing accordingly.

The disposal method of waste plastics generated in the abandoned vehicles is mainly dependent on landfill, and some of them are incinerated. Recently, a serious social problem is caused by the secondary environmental pollution such as the absolute shortage of landfill and the generation of harmful gases due to incineration. It is becoming a problem.

In particular, the incineration process has the advantage of high throughput of waste plastics and maximum heat utilization, but the high calorific value of the plastic itself and the corrosive combustion such as SOx, NOx and HCI generated when incineration of some plastics. Due to the gas, incineration furnaces are frequently shut down, and there are problems of tertiary environmental pollution due to exhaust gas and dust.

Accordingly, as the problem of environmental pollution caused by the disposal of used vehicles has emerged, research on recycling of used vehicles has rapidly increased.

Until now, these waste plastic materials are usually processed through a passive and highly device-dependent method of decomposing the resin by pyrolysis or chemical decomposition regeneration to produce fuel oil or naphtha, or simply burning the waste plastic material to obtain energy. It is true.

As a patent related to recycling of polymer materials for automobiles in the prior art, Korean Patent Publication No. 99-049342 discloses effective recycling of a waste bumper by effectively removing a thermosetting paint film attached to a resin layer of an automobile bumper.

In addition, Japanese Patent No. 11,156,854 discloses the possibility of recycling an automobile sheet into an automobile interior material by mixing it with an unfoamed material.

However, no patents have been published for polypropylene and poly (acrylonitrile-butadiene-styrene) polymer mixtures, which account for more than 80% of automotive interior materials.

On the other hand, the polymer blend is used as a method for developing new polymers by simply mixing two or more polymers that are already commercially produced to achieve breakthrough physical properties. However, most of the polymers are incompatible with each other (immiscible), leading to severe degradation of mechanical properties. Therefore, if you can overcome this, you can achieve the desired purpose.

Methods for increasing the incompatibility of a polymer include a copolymer compatible with both polymers as a compatibilizer; Using a copolymer having a functional group to cause a reaction with the polymer during mixing; And a method of activating the surface of the polymer through a plasma treatment.

Various methods of commercialization have been studied and reported so far, but the use of a compatibilizer as an additive is most effectively known, and most commercially successful polymer alloys are manufactured using a compatibilizer addition method.

Polymer compatibilizers are added to effectively mix two or more types of polymers. As the polymer compatibilizer, graft or block copolymer having the same chemical structure as the blend component is known to be effective, and pre-made block and graft copolymer and in-situ type are mixed depending on the method of introducing the compatibilizer during the mixing process. Divided into reactive compatibilizers. In the case of reactive compatibilizers, block or graft copolymers are introduced at the interface through chemical reaction between the compositional polymer and the functional groups introduced into the compatibilizer during melt mixing.

However, there have been no reports of compatibilizers for polypropylene and ABS used in automobiles at present.

Accordingly, the present inventors have tried to prepare a composition having excellent mechanical properties by blending polypropylene and ABS used in automobiles with an appropriate compatibilizer, and thus a copolymer of propylene and styrene-acrylonitrile (PP-SAN). The thermoplastic resin composition was prepared using as a compatibilizer. The thermoplastic resin composition of the present invention improved the flexural strength, impact strength, tensile strength, elongation, and heat deformation temperature, which are important as mechanical properties, compared to the mixture without the compatibilizer. The present invention was completed by finding that it can be usefully used as a plastic.

Accordingly, an object of the present invention is to provide a thermoplastic resin composition prepared by adding a compatibilizer exhibiting compatibility to both polymers to a polypropylene and ABS polymer blend showing incompatibility with each other.

1 to 5 show photographs of the surface of the thermoplastic resin composition obtained in Examples and Comparative Examples of the present invention under an electron scanning microscope.

The present invention provides a thermoplastic resin composition comprising a polypropylene, an ABS polymer and a copolymer of propylene and styrene-acrylonitrile as a compatibilizer.

This invention will be described in more detail.

Thermoplastic resin composition of the present invention is characterized by increasing the mechanical properties by increasing the compatibility of the polymer using a specific compatibilizer.

The polypropylene (hereinafter referred to as "PP") and poly (acrylonitrile-butadiene-styrene) (hereinafter referred to as "ABS") is not compatible with each other is poor compatibility with each other, the polymers are aggregated together and impossible to use. Even if the product is manufactured, even if it is damaged, its physical properties are very poor.

In the present invention, by using a compatibilizer having excellent compatibility with each of the polymers to lower the interfacial tension of the polymer to increase the compatibility. Using the copolymer of PP and SAN as the compatibilizer to improve the compatibility between the polymer and provides a physical property of the thermoplastic resin produced by mixing.

The thermoplastic resin composition of the present invention comprises 35 to 60% by weight of polypropylene, 40 to 65% by weight of poly (acrylonitrile-butadiene-styrene), and propylene and styrene-acrylonitrile copolymer as a compatibilizer (poly (styrene- acrylonitrile) copolymer: hereinafter referred to as "PP-SAN") 5 to 20 phr.

The PP-SAN copolymer is a block copolymer represented by the following Chemical Formula 1.

Formula 1

The PP-SAN copolymer shows compatibility with both PP and ABS resins. The PP-SAN copolymer used in the present invention is present at the interface of each polymer when blending the PP and ABS resins, thereby lowering the interfacial tension of the polymer, thereby densifying the size of each polymer particle, resulting in compatibility. Raised.

PP-SAN used in the present invention is a block copolymer having a copolymerization ratio (ratio) of 70:30, a number average molecular weight of 50,000 to 80,000, and a melt index of 8.0 to 9.0.

If the content of the copolymer compatibilizer is less than the above range, the compatibility between the polymers is lowered, and the physical properties of the prepared composition are lowered. If the content of the copolymer compatibilizer is exceeded, the compatibility is increased, but no further meaning is not economically desirable. .

Specifically, according to an embodiment of the present invention, the thermoplastic resin composition to which the copolymer compatibilizer is added can be seen that the impact strength, tensile strength, elongation and heat deformation temperature are improved as the content of the compatibilizer is used.

More specifically, when the surface of the thermoplastic resin composition containing or not the copolymer compatibilizer was examined by electron scanning microscope, the surface of the thermoplastic resin composition containing no copolymer compatibilizer (FIG. 5) containing the compatibilizer (Fig. 5). Compared with 1-5, it turns out that a very rough surface is shown. In addition, it can be seen that the agglomerates of the polymer lumps at the interface of the mixture disappears. This can be said to increase the compatibility of the mixture by reducing the interfacial tension while reacting with the mixed polymer by the addition of a compatibilizer.

In addition, the polymer used in the present invention is specifically as follows.

The PP is a polymer represented by the following formula (2).

Formula 2

The PP used in the present invention uses a virgin PP and a PP containing 10 to 30% by weight of an inorganic filler. PP is an isotactic polymer, which resists stress, cracking, etc., and has excellent tensile strength and heat resistance, high impact resistance, and excellent transparency.

The PP has a number average molecular weight of 200,000 to 250,000, a melt index of 8 to 10 g / 10 min, and a density of 0.9 to 0.95 g / cm ³ . In the present invention, the content of PP is contained 4 to 60% by weight based on the total thermoplastic resin composition.

The inorganic filler is used to increase the mechanical strength of PP and contains 10 to 30% by weight. In this case, if the content is less than the above range, the effect as a reinforcing material is low, and if it exceeds the above range, it is not preferable due to process difficulties. This inorganic filler is selected from the group consisting of talc, mica, calcium carbonate, preferably using talc.

The PP used in the present invention uses a grade substantially used for automobile materials.

The ABS is a polymer represented by the following formula (3).

Formula 3

ABS resin of the present invention is excellent in heat resistance and impact resistance has been used as interior and exterior materials of automobiles. The ABS resin has a number average molecular weight of 30,000 to 35,000, a melt index of 0.8 to 0.9 g / 10 min, and a density of 1.02 to 1.05 g / cm ³ . In the present invention, the content of the ABS resin is 36 to 45% by weight based on the total thermoplastic resin composition. .

In particular, the PP and ABS resin used in the present invention can be used that is recovered from the waste vehicle.

In the thermoplastic resin composition of the present invention, an additive may be added according to various purposes, and the type and content of the additive are selected by those skilled in the art. For example, the additive may include a heat stabilizer, an antioxidant, an ultraviolet stabilizer or a colorant.

According to the present invention, the thermoplastic resin composition using the PP-SAN copolymer as a compatibilizer for PP and ABS resins does not exhibit incompatibility generated during conventional polymer blending and has excellent compatibility and thus improves mechanical properties.

Specifically, according to the embodiment of the present invention, it can be seen that the thermoplastic resin composition to which the copolymer compatibilizer is added increases the impact strength, tensile strength, elongation and heat deformation temperature as the content of the copolymer compatibilizer is used.

More specifically, the surface of the thermoplastic resin composition with or without the copolymer compatibilizer was examined by electron scanning microscopy. As a result, the surface of the thermoplastic resin composition without the copolymer compatibilizer (Fig. 5) contained the compatibilizer (Fig. 5). It can be seen that compared to 1 to 4) shows a very rough surface.

The thermoplastic resin composition of the present invention is manufactured by compression molding, extrusion molding, injection molding, blow molding, and vacuum molding by a conventionally used polymer blending method. vaccum molding) and the like may be used, and the present invention is not particularly limited.

For example, pure PP, an inorganic filler, an ABS resin, and a compatibilizer are injected into a hopper, dried, injected into a twin screw extruder, extruded, and manufactured into pellets. The prepared pellet is molded into a desired shape through an injection machine.

As described above, the thermoplastic resin composition of the present invention has low specific gravity and high impact strength, as well as excellent heat resistance, excellent moldability and bendability, and good workability. In particular, the PP of the present invention is very economical as it is possible to use the PP recovered from the vehicle, it is possible to suppress the environmental pollution caused by waste, and it is possible to re-apply the thermoplastic resin composition to the parts of the vehicle to reduce the weight of the automobile Of course, recycling of resources is possible.

Hereinafter, the present invention will be described in detail by the following examples.

However, the present invention is not limited by the following examples and various modifications and supplements are possible within the scope of the claims.

Examples 1-4 and Comparative Example 1

Next, a thermoplastic resin composition including the composition of Table 1 was prepared.

Furtherance Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Polymer (% by weight) PP with talc 43 43 43 43 43 Pure PP 11 11 11 11 11 ABS resin 46 46 46 46 46 Compatibilizer (phr) PP-SAN 5 10 15 20 -

Specifically, pure PP used a melt index of 10.0 g / 10 min (according to ASTM D1238), ABS resin using a melt index of 0.9 g / 10 min (according to ASTM D1238), and a particle size of 20 PP having a melt index of 10 g / 10 min with talc in mm was used.

As compatibilizers were added 0, 5 phr (parts per one hundred resin (weight fraction based on resin 100)), 10 phr, 15 phr and 20 phr, respectively, of PP-SAN.

First, talc-containing PP, pure PP, ABS resin, and a compatibilizer PP-SAN were injected into a drying oven, and then dried at 90 ° C. for 3 hours. Subsequently, after the completion of the drying process, the mixture was injected into a hopper and melt mixed using a twinscrew extruder. At this time, the temperature of the extruder was set to 150 → 180 → 200 → 220 → 230 → 240 → 250 ° C. in the die direction from the hopper, and the same direction as the (screw length) / (screw diameter) of 32 The thermoplastic resin composition was prepared by mixing pure PP, PP containing talc, and ABS resin at a speed of 200 rpm using a bi-screw.

Test Example 1: Measurement of mechanical properties

In order to measure the physical properties of the thermoplastic resin composition prepared in Examples 1 to 4 and Comparative Example 1 was carried out as follows.

First, the prepared thermoplastic resin composition was processed into pellets, and then dried in a drying oven at 90 ° C. for 3 hours. The dried mixture pellets are prepared into specimens via an injection molding machine. The temperature of the injection machine was set to 220 → 240 → 250 → 250 ° C. in the nozzle direction in the hopper, and the injection pressure was set to 40 → 45 → 50 kg / cm 2. this?? The holding pressure was performed at 50 kg / cm 2 for 5 seconds, and the back pressure was set at 55 kg / cm 2.

The following physical properties were measured using the prepared specimens, and the results are shown in Table 2 below.

Flexural strength (MPa)

In accordance with ASTM D790 it was measured in a three-point bending method at room temperature conditions.

2. Impact strength (MPa)

In accordance with ASTM D256 it was measured by the Izod method at room temperature conditions.

3. tensile strength (MPa)

In accordance with ASTM D638 was measured in a mode 1 manner at room temperature conditions.

4. Elongation (%)

In accordance with ASTM D638 was measured in a mode 1 manner at room temperature conditions.

5. Heat distortion temp (℃)

According to ASTM D648 it was measured at 4.6 kg / cm ² load at 120 ℃ C / hr conditions.

Mechanical properties Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Flexural Strength (Mpa) 38.5 38.0 35.3 37.7 33.1 Impact strength (MPa) 2.42 2.45 2.47 2.54 2.35 Tensile Strength (MPa) 23.1 23.9 21.0 21.8 18.8 % Elongation 1.93 1.94 1.87 1.89 1.75 Heat Deflection Temperature (℃) 91.6 92.3 89.2 88.2 89.0

According to Table 2, the flexural strength showed a physical property value of 33.1 MPa in Comparative Example 1 without adding a compatibilizer, but in Example 1 with 10 phr of a compatibilizer, the maximum value was 38.5 MPa.

Impact strength (impact strength) tended to increase continuously as the amount of added compatibilizer increased from 5 phr to 20 phr.

Tensile strength also exhibited a physical property value of 18.8 MPa in Example 1 without adding a compatibilizer, and showed a maximum value of the physical property at 23.9 MPa in Example 3 with 10 phr of a compatibilizer.

The extensional ratio was also shown to be the maximum value of 19.4% in the vicinity of Example 3, and the heat distortion temperature was also added to the compatibilizer (PP-SAN) at 89 ° C. of Comparative Example 1, in which no compatibilizer was added. In Example 4, the temperature was increased to 92.3 ° C.

The compatibilizer is present at the interface of the polymer to lower the interfacial tension of the polymer when mixed, thereby increasing the compatibility of the polymer mixture.

From the above measurement results, PP-SAN, a copolymer compatibilizer used in the present invention, increased the compatibility of PP and ABS, and showed an improvement in mechanical properties when the addition amount of the compatibilizer (PP-SAN) was 5-10 phr. there was.

Test Example 2 Surface Analysis

In order to observe the surfaces of the thermoplastic resin compositions of Examples 1 to 4 and Comparative Example 1 were measured using an electron scanning microscope (SEM), these results are shown in Figures 1 to 5.

1 shows the surface of a specimen prepared from a thermoplastic resin composition containing 5 phr of the copolymer compatibilizer of Example 1,

Figure 2 shows the surface of the specimen made of a thermoplastic resin composition containing 10 phr of the copolymer compatibilizer of Example 2,

Figure 2 shows the surface of the specimen made of a thermoplastic resin composition containing 15 phr of the copolymer compatibilizer of Example 3,

Figure 4 shows the surface of the specimen made of a thermoplastic resin composition containing 20 phr copolymer compatibilizer of Example 4,

Figure 5 shows the surface of a specimen made of a thermoplastic resin composition containing no copolymer compatibilizer of Comparative Example 1.

1 to 4, the interfacial tension of the mixed polymers decreases due to the addition of the copolymer compatibilizer (PP-SAN), so that the fracture surface of the mixture is dense. It can be seen.

In contrast, according to FIG. 5 (Comparative Example 1) without adding a copolymer compatibilizer, it can be seen that a very rough surface morphology is formed as compared with FIGS. 1 to 4 (Examples 1 to 4).

As described above, the present invention was prepared by adding a PP-SAN copolymer compatibilizer to the non-mixing PP and ABS resin to prepare a thermoplastic resin composition having excellent compatibility, the resin composition has excellent surface properties and mechanical properties, As the PP can use waste plastic, it is possible to recycle resources, which is very economical and can reduce environmental pollution due to waste. In particular, the technology using the copolymer compatibilizer of the present invention is very important as a source technology of the new material and recycled material mixing technology in the future as a technology of mixing the two materials with extreme physical properties.

Claims (8)

A thermoplastic resin composition comprising polypropylene, poly (acrylonitrile-butadiene-styrene), and a copolymer of propylene and styrene-acrylonitrile (PP-SAN) as a copolymer compatibilizer. The thermoplastic resin composition according to claim 1, wherein the content of the copolymer of propylene and styrene-acrylonitrile is 5 to 10 phr. The copolymer according to any one of claims 1 to 2, wherein the copolymer of propylene and styrene-acrylonitrile is a block copolymer having a copolymerization degree (ratio) of 70:30 and a number average molecular weight of 50,000 to 80,000. Thermoplastic resin composition. The thermoplastic resin composition according to claim 1, wherein the polypropylene content is 35 to 60% by weight. The thermoplastic resin composition according to claim 1, wherein the content of the poly (acrylonitrile-butadiene-styrene) is 40 to 65% by weight. The thermoplastic resin composition according to claim 1 or 4, wherein the polypropylene comprises 10 to 30% by weight of an inorganic filler. 7. The thermoplastic resin composition according to claim 6, wherein the inorganic filler is selected from talc, mica and calcium carbonate. An automobile part manufactured using the thermoplastic resin composition of claim 1.