KR102264007B1 - Thermoplastic resin composition for blow molding, and molded article using the same - Google Patents

Abstract

(A) 20 to 40 wt% of a diene-based graft copolymer, (B) 10 to 20 wt% of an aromatic vinyl compound-vinyl cyanide compound copolymer, (C) 30 to 50 wt% of an alpha-methylstyrene copolymer, and ( D) 100 parts by weight of a base resin comprising 10 to 20% by weight of an N-phenylmaleimide copolymer; And it relates to a thermoplastic resin composition for blow molding comprising 0.1 to 3 parts by weight of inorganic particles that are (E) zinc sulfide, titanium dioxide, talc, or a combination thereof based on 100 parts by weight of the base resin, and a molded article using the same.

Description

Thermoplastic resin composition for blow molding and molded article using same {THERMOPLASTIC RESIN COMPOSITION FOR BLOW MOLDING, AND MOLDED ARTICLE USING THE SAME}

It relates to a thermoplastic resin composition for blow molding and a molded article using the same.

Acrylonitrile-butadiene-styrene copolymer (hereinafter referred to as ABS) resin has excellent physical properties such as impact resistance, chemical resistance, and molding processability, and is widely used in various office equipment, electrical and electronic parts, and interior and exterior materials of automobiles. Among them, a molding process of a rear spoiler, which is an automobile exterior material, is manufactured using blow molding.

Blow molding is a manufacturing method by molding a parison by injection, and injecting air thereto. Specifically, after melting the resin using an extruder, a die capable of forming a hollow shape such as a hollow pipe shape is attached to the end of the extruder to form a parison. After letting the vertically descending parison go into the open blow mold, close the mold to cut the parison, and then blow air into the parison to manufacture the desired molded product.

In general, the ABS resin has a risk of quality deterioration due to the occurrence of fine pores on the surface during blow molding, and accordingly, surface processing, that is, sanding is required.

In order to increase the ease of sanding, a method of lowering the surface hardness through an increase in the rubber content of the ABS resin has been conventionally used. However, when the rubber content is increased, it is difficult to maintain physical properties such as heat resistance and fluidity, and there is a limit in improving sanding easiness.

An object of the present invention is to provide a thermoplastic resin composition for blow molding that can improve the surface quality of a molded article by increasing the efficiency of surface processing after blow molding, that is, increase sanding easiness, as well as ensure heat resistance and fluidity.

The thermoplastic resin composition for blow molding according to an embodiment comprises (A) 20 to 40 wt% of a diene-based graft copolymer, (B) 10 to 20 wt% of a copolymer of an aromatic vinyl compound-vinyl cyanide compound, (C) alpha - Based on 100 parts by weight of the base resin comprising 30 to 50% by weight of the methylstyrene copolymer, and 10 to 20% by weight of the N-phenylmaleimide copolymer, (E) zinc sulfide, titanium dioxide, talc, or 0.1 to 3 parts by weight of inorganic particles that are a combination thereof.

A molded article according to another embodiment includes the above-described thermoplastic resin composition.

It is possible not only to secure heat resistance and fluidity, which are characteristics required for a general thermoplastic resin composition, but also to create fine irregularities on the surface in the surface processing operation after blow molding, thereby reducing the sanding operation time and increasing the post processing operation efficiency. .

1 and 2 are optical micrographs showing the surface of the specimen before and after the wear evaluation of Example 2, respectively, and FIGS. 3 and 4 are optical micrographs showing the surface of the specimen before and after the wear evaluation of Comparative Example 1, respectively.

Hereinafter, embodiments of the present invention will be described in detail. However, this is presented as an example, and the present invention is not limited thereto, and the present invention is only defined by the appended claims.

According to one embodiment, (A) 20 to 40 wt% of a diene-based graft copolymer, (B) 10 to 20 wt% of a copolymer of an aromatic vinyl compound-vinyl cyanide compound, (C) 30% by weight of an alpha-methylstyrene copolymer to 50% by weight, and (D) 100 parts by weight of a base resin comprising 10 to 20% by weight of an N-phenylmaleimide copolymer; And (E) provides a thermoplastic resin for blow molding comprising 1 to 3 parts by weight of inorganic particles that are zinc sulfide, titanium dioxide, talc, or a combination thereof based on 100 parts by weight of the base resin.

Hereinafter, each component included in the thermoplastic resin composition for blow molding will be described in detail.

(A) diene-based graft copolymer

The diene-based graft copolymer of the present invention may be a core-shell type graft copolymer in which a core is a diene-based rubbery polymer and a shell is a copolymer of an aromatic vinyl compound and a vinyl cyanide compound. This can be prepared by graft copolymerization of a mixture containing an aromatic vinyl compound and a vinyl cyanide compound to a diene-based rubbery polymer. The polymerization method is not limited as long as it is a method clearly known in the art, and may be prepared, for example, by bulk polymerization, suspension polymerization and emulsion polymerization.

As an example, the diene-based graft copolymer is, based on the total weight of the diene-based rubbery polymer, the aromatic vinyl compound, and the vinyl cyanide compound, in the presence of 40 to 60% by weight of the diene-based rubbery polymer, an aromatic vinyl compound and It can be prepared by graft copolymerization of 40 to 60% by weight of a mixture of vinyl cyanide compounds by emulsion polymerization.

In this case, the diene-based rubbery polymer may be a butadiene rubber, a copolymer rubber of butadiene and styrene, or a copolymer rubber of butadiene and acrylonitrile. More specifically, it may be a butadiene rubber.

In addition, the diene-based rubbery polymer may have an average particle diameter of 0.1 to 0.5 μm, for example, 0.1 to 0.3 μm. When the average particle diameter is less than 0.1 μm, impact resistance may decrease, and when it exceeds 0.5 μm, a problem of deterioration in appearance may occur.

The mixture of the vinyl cyanide compound and the aromatic vinyl compound graft-copolymerized to the diene-based rubbery polymer may be composed of 20 to 40 wt% of the vinyl cyanide compound and 60 to 80 wt% of the aromatic vinyl compound.

As the vinyl cyanide compound, acrylonitrile, methacrylonitrile, fumaronitrile, etc. may be used, and these may be used alone or in combination of two or more. For example, acrylonitrile may be used.

As the aromatic vinyl compound, styrene, C1-C10 alkyl-substituted styrene, halogen-substituted styrene, vinyl toluene, vinyl naphthalene, etc. may be used, and these may be used alone or in combination of two or more. For example, styrene may be used.

The diene-based graft copolymer may be included in an amount of 20 to 40% by weight, for example, 25 to 40% by weight, based on 100% by weight of the base resin including (A) to (D). When the diene-based graft copolymer is less than 20% by weight, impact resistance is lowered, and when it exceeds 40% by weight, moldability may be weakened.

(B) Copolymer of aromatic vinyl compound-vinyl cyanide compound

The copolymer of the aromatic vinyl compound-vinyl cyanide compound of the present invention is formed by copolymerizing a vinyl cyanide compound and an aromatic vinyl compound.

As the vinyl cyanide compound, one selected from the group consisting of acrylonitrile, methacrylonitrile, fumaronitrile, and combinations thereof may be used.

As the aromatic vinyl compound, C1 to C10 alkyl-substituted styrene, halogen-substituted styrene, vinyl toluene, vinyl naphthalene, etc. may be used, and these may be used alone or in combination of two or more thereof.

The copolymer of the vinyl cyanide compound-aromatic vinyl compound may be a styrene-acrylonitrile copolymer (SAN).

The thermoplastic resin composition according to an embodiment contains 50 to 90 parts by weight of a structural unit derived from an aromatic vinyl compound, and 10 structural units derived from a vinyl cyanide compound based on 100 parts by weight of the aromatic vinyl compound-vinyl cyanide copolymer. to 50 parts by weight.

The copolymer of the aromatic vinyl compound-vinyl cyanide compound may have a weight average molecular weight of 100,000 to 600,000 g/mol, for example, 100,000 to 300,000 g/mol, for example, 100,000 to 200,000 g/mol.

The aromatic vinyl compound-vinyl cyanide compound copolymer may be in an amount of 10 to 20 wt%, for example 12 to 18 wt%, based on 100 wt% of the base resin including (A) to (D). When the content of the copolymer of the aromatic vinyl compound-vinyl cyanide compound is out of the above range, there is a fear that the impact resistance and blow molding moldability of the thermoplastic resin composition may be deteriorated.

According to a preferred embodiment of the present invention, the copolymer of (B) aromatic vinyl compound-vinyl cyanide compound is a styrene-acrylonitrile copolymer (SAN) resin, and (C) an alpha-methylstyrene copolymer described later and It may have a different weight average molecular weight.

(C) α-Methylstyrene (AMS) copolymer

The alpha-methylstyrene copolymer is a copolymer of a mixture containing alpha-methylstyrene (AMS) and a monomer copolymerizable therewith, for example, a copolymer of alpha-methylstyrene and acrylonitrile, alpha-methylstyrene, and acrylonitrile. It may be a copolymer of nitrile, and styrene. The alpha-methylstyrene copolymer may be prepared by, for example, copolymerizing 50 to 80 parts by weight of alpha-methylstyrene, 20 to 50 parts by weight of acrylonitrile, and 0 to 10 parts by weight of styrene in a predetermined ratio. At this time, when the amount of alpha-methylstyrene is less than 50 parts by weight, there may be problems in that the heat resistance is lowered and discoloration is easily caused by heat during processing. There may be a problem in that a large amount of structures in which three or more alpha-methylstyrene, which are easily decomposed by heat, are continuously combined in the coalescing chain are generated. In addition, when the styrene content exceeds 10 parts by weight, there may be a problem that the heat resistance is lowered.

The alpha-methylstyrene copolymer may be in an amount of 30 to 50 wt%, for example 30 to 45 wt%, based on 100 wt% of the base resin including (A) to (D). When the amount of the alpha-methylstyrene copolymer is less than 30% by weight, sufficient heat resistance cannot be obtained, and when it exceeds 50% by weight, there is a risk that impact resistance may be deteriorated.

In addition, the content of the alpha-methylstyrene copolymer may be 200 to 400 parts by weight based on 100 parts by weight of the (B) aromatic vinyl compound-vinyl cyanide copolymer copolymer. When the alpha-methylstyrene copolymer is less than 200 parts by weight, sufficient heat resistance cannot be obtained, and when it exceeds 400 parts by weight, there is a problem in that impact resistance is lowered.

(D) N-Phenyl Maleimide (PMI) copolymer

The N-phenylmaleimide copolymer may be a copolymer of N-phenylmaleimide, an aromatic vinylic monomer, and maleic anhydride. The N-phenylmaleimide copolymer may be prepared by imidation of the aromatic vinyl-based monomer and the maleic anhydride copolymer, and the glass transition temperature (Tg) may be 180 to 200°C.

The N-phenylmaleimide copolymer may be, for example, a copolymer of N-phenylmaleimide-styrene-maleic anhydride. The copolymer of N-phenylmaleimide-styrene-maleic anhydride includes 45 to 55% by weight of structural units derived from N-phenylmaleimide, 40 to 50% by weight of structural units derived from styrene, and maleic anhydride. It may be composed of 1 to 10% by weight of the structural unit.

The N-phenylmaleimide copolymer may be in an amount of 10 to 20% by weight, for example, 10 to 15% by weight, based on 100% by weight of the base resin including (A) to (D). When the N-phenylmaleimide copolymer is less than 10% by weight, sufficient heat resistance cannot be obtained, and when it exceeds 20% by weight, there is a fear that appearance and impact resistance may be deteriorated.

In addition, the content of the N-phenylmaleimide copolymer may be 50 to 160 parts by weight based on 100 parts by weight of the (B) aromatic vinyl compound-vinyl cyanide copolymer copolymer. When the content of the N-phenylmaleimide copolymer is within the above range, excellent heat resistance and impact resistance may be exhibited.

In addition, the N-phenylmaleimide copolymer may be included in an amount of 25 to 40 parts by weight based on 100 parts by weight of the (C) alpha-methylstyrene copolymer. When the amount of the N-phenylmaleimide copolymer is less than 25 parts by weight, sufficient heat resistance cannot be obtained, and when it exceeds 40 parts by weight, it is difficult to finish (trimming) and there is a fear that post-processability may be deteriorated.

(E) inorganic particles

The thermoplastic resin composition for blow molding of the present invention may include one or more inorganic particles selected from _{zinc sulfide (ZnS), titanium dioxide (TiO 2 ), and talc.}

The average particle diameter (D50) of the inorganic particles may be 5 to 10 mm, but is not limited thereto. When the average particle diameter of the inorganic particles is within the above range, it is easy to sand (sanding), thereby exhibiting an excellent effect of post-processing properties.

The inorganic particles may be included in an amount of 0.1 to 3 parts by weight, for example, 0.5 to 3 parts by weight based on 100 parts by weight of the base resin. When the amount of the inorganic particles is less than 0.1 parts by weight, it is difficult to express the effect of sanding easiness, and when it exceeds 3 parts by weight, the size of the unevenness formed on the surface of the molded article during blow molding becomes too large, and there is a fear that the ease of sanding may be reduced.

(F) other additives

The thermoplastic resin composition for blow molding may optionally further include an additive according to its use. The additive may include a flame retardant, a lubricant, a plasticizer, a heat stabilizer, an antioxidant, a light stabilizer, or a colorant, and may be used by mixing two or more types according to the characteristics of the final molded product.

The flame retardant is a material that reduces combustibility, a phosphate compound, a phosphite compound, a phosphonate compound, a polysiloxane, a phosphazene compound, a phosphinate compound, or a melamine compound It may include at least one of, but is not limited thereto.

The lubricant is a material that lubricates the metal surface in contact with the thermoplastic resin composition during processing/molding/extrusion to help flow or movement of the resin composition, and a commonly used material may be used.

The plasticizer is a material that increases flexibility, processing workability, or expandability of the thermoplastic resin composition, and a commonly used material may be used.

The thermal stabilizer is a material that suppresses thermal decomposition of the thermoplastic resin composition when kneaded or molded at a high temperature, and a commonly used material may be used.

The antioxidant inhibits or blocks the chemical reaction between the thermoplastic resin composition and oxygen, thereby preventing the resin composition from being decomposed and losing intrinsic properties. Among the phenol-type, phosphite-type, thioether-type or amine-type antioxidants, the antioxidant It may include at least one, but is not limited thereto.

The light stabilizer is a material that inhibits or blocks the color change or loss of mechanical properties due to decomposition of the thermoplastic resin composition from ultraviolet rays, preferably at least one of a hindered phenol type, benzophenone type, or benzotriazole type light stabilizer. may be included, but is not limited thereto.

As the colorant, conventional pigments or dyes may be used.

The additive may be included in an amount of 0.1 to 15 parts by weight based on 100 parts by weight of the base resin.

The thermoplastic resin composition according to the present invention may be prepared by a known method for preparing a resin composition.

For example, the thermoplastic resin composition according to the present invention may be manufactured in the form of pellets by a method of melt-extruding in an extruder after mixing the components of the present invention and other additives at the same time.

The molded article according to an embodiment of the present invention may be manufactured from the above-described thermoplastic resin composition. The thermoplastic resin composition has excellent heat resistance and impact resistance, and excellent moldability and appearance, so that it can be applied without limitation to a molded article for blow molding, and specifically can be used as an exterior material for automobiles.

The molded article using the thermoplastic resin composition according to the present invention may have a heat deflection temperature of 95 to 105° C. measured according to ASTM D648.

Hereinafter, the present invention will be described in more detail through Examples and Comparative Examples, but the following Examples and Comparative Examples are for illustrative purposes and are not intended to limit the present invention.

Hereinafter, preferred embodiments of the present invention will be described. However, the following examples are only preferred examples of the present invention, and the present invention is not limited by the following examples.

Examples 1-2 and Comparative Examples 1-2

The resin compositions of Examples 1 and 2 and Comparative Examples 1 and 2 were prepared according to the component content ratios shown in Table 1 below.

In Table 1, the components (A, B, C, D) constituting the base resin are expressed in weight percent based on the total weight of the base resin, and the inorganic particles (E1, E2) added to the base resin are It is expressed in parts by weight based on 100 parts by weight of the resin.

The components listed in Table 1 were dry-mixed and quantitatively continuously added to the supply part of a twin-screw extruder (L/D=29, Φ=45 mm) to melt/knead. Then, after drying the pelletized thermoplastic resin composition through a twin-screw extruder at about 80 ° C. for about 2 hours, a 6 oz injection molding machine with a cylinder temperature of about 260 ° C and a mold temperature of about 60 ° C. injection molded.

division Example 1 Example 2 Comparative Example 1 Comparative Example 2 base resin
(Unit: % by weight) (A) 33 33 33 38 (B) 15 11 11 11 (C) 41 41 41 36 (D) 11 15 15 15 inorganic particles
(Unit: parts by weight) (E1) One 0 0 11 (E2) 0 One 0 0

A description of each configuration shown in Table 1 is as follows.

base resin

(A) diene-based graft copolymer

An acrylonitrile-butadiene-styrene graft copolymer (g-ABS) manufactured by Lotte Advanced Materials having an average particle diameter of about 0.3 μm and a butadiene rubber content of about 58 wt% was used.

(B) Copolymer of aromatic vinyl compound-vinyl cyanide compound

A styrene-acrylonitrile copolymer (SAN) manufactured by Lotte Advanced Materials Co., Ltd. having a structural unit content derived from acrylonitrile of about 32 wt% and a weight average molecular weight of about 120,000 g/mol was used.

(C) alpha-methylstyrene copolymer

Alpha-methylstyrene-styrene-acrylonitrile copolymer (AMS-SAN) of Lotte Advanced Materials, having a structural unit content derived from alpha-methylstyrene of about 54% by weight and a weight average molecular weight of about 130,000 g/mol was used.

(D) N-phenylmaleimide copolymer

Denka's N-phenylmaleimide-styrene-maleic acid having a structural unit content of about 50% by weight, a glass transition temperature (Tg) of 196°C, and a weight average molecular weight of about 150,000 g/mol derived from N-phenylmaleimide Anhydride copolymer (product name: MS-NB) was used.

inorganic particles

(E1) zinc sulfide (ZnS)

Zinc sulfide (product name: SACHTOLITH ^® HD-S) manufactured by Sachtleben Chemie was used.

(E2) titanium dioxide (TiO ₂ )

Cristal's titanium dioxide (product name: TiONA ^® 188) was used.

physical test

For the specimens prepared in Examples 1 to 2 and Comparative Examples 1 to 2, physical properties were tested as follows, and the results are shown in Table 2.

(1) Fluidity (unit: g/10 min)

Melt-flow index (MI) was measured at 220°C under a load of 10 kgf according to ASTM D1238.

(2) Heat resistance (unit: ℃)

(2-1) Vicat softening temperature (VST) was measured according to ISO 306/B50.

(2-2) Heat deflection temperature (HDT) was measured under a load of 1.8 MPa for a 1/4 inch thick specimen according to ASTM D648.

(3) Impact resistance (unit: kgf cm/cm)

Notched Izod impact strength (Izod impact strength, notched) was measured for a 1/4 inch thick specimen according to ASTM D256.

(4) Sanding properties (unit: wt%)

After stabilizing the 100 mm x 100 mm x 3.2 mm specimen at room temperature for 24 hours, use a wear-resistance evaluation equipment (manufacturer: Taber Industries, model name: Taber ^® Rotary Abraser 5135) for 40 minutes under the conditions of 1 kgf load and grinding machine rotation speed of 70 rpm. The wear evaluation was carried out and the amount of wear of the specimen was calculated using the difference in the weight of the specimen before and after evaluation. It was judged that the greater the amount of wear, the better the sanding (sanding) easiness.

(5) Surface appearance

The presence or absence of gas silver (silver streak) and/or whitening on the surface of the specimen was visually evaluated. When gas silver and/or whitening did not occur, it determined with (circle), and when it generate|occur|produced, it determined with x.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 MI 6.0 6.0 6.0 8.0 VST 112 112 112 108 HDT 101 101 100 95 Izod impact strength 20 19 19 21 wear 0.38 0.39 0.30 0.38 surface appearance ○ ○ × ×

On the other hand, optical micrographs showing the surface of the specimen before and after the wear evaluation of Example 2 and Comparative Example 1 are shown in FIGS. 1 to 4 .

1 and 2 are optical micrographs showing the surface of the specimen before and after the wear evaluation of Example 2, respectively, and FIGS. 3 and 4 are optical micrographs showing the surface of the specimen before and after the wear evaluation of Comparative Example 1, respectively.

Referring to Tables 1 and 2 and FIGS. 1 to 4, in the case of the thermoplastic resin compositions according to Examples 1 and 2, while maintaining excellent impact resistance and heat resistance, the surface appearance is improved and the ease of sanding is improved at the same time to improve the appearance quality and operation of the molded article It can be confirmed that ease and productivity are improved. It is understood that the inorganic particles contained in the thermoplastic resin composition according to Examples 1 and 2 generate fine irregularities on the surface of the molded article, thereby improving the ease of sanding.

In the above, the present invention has been described through preferred embodiments as described above, but the present invention is not limited thereto and various modifications and variations are possible without departing from the concept and scope of the claims described below. Those skilled in the art to which the invention pertains will readily understand.

Claims (10)

(A) 20 to 40 wt% of a diene-based graft copolymer,
(B) 10 to 20 wt% of an aromatic vinyl compound-vinyl cyanide compound copolymer;
(C) 30 to 50% by weight of an alpha-methylstyrene copolymer, and
(D) 100 parts by weight of a base resin comprising 10 to 20% by weight of an N-phenylmaleimide copolymer; And
0.1 to 3 parts by weight of inorganic particles (E) zinc sulfide, titanium dioxide, or a combination thereof based on 100 parts by weight of the base resin
including,
Based on 100 parts by weight of the (B) aromatic vinyl compound-vinyl cyanide copolymer copolymer, the (C) alpha-methylstyrene copolymer is 200 to 400 parts by weight, and the (D) N-phenylmaleimide copolymer is 50 to A thermoplastic resin composition for blow molding, which is included in 160 parts by weight. In claim 1,
Based on 100 parts by weight of the (C) alpha-methylstyrene copolymer, the (D) N-phenylmaleimide copolymer is included in an amount of 25 to 40 parts by weight of a thermoplastic resin composition for blow molding. delete In claim 1,
The (B) aromatic vinyl compound-vinyl cyanide compound copolymer has a weight average molecular weight of 100,000 to 600,000 g/mol of a thermoplastic resin composition for blow molding. In claim 1,
The content of the structural unit derived from the aromatic vinyl compound is 50 to 90 parts by weight with respect to 100 parts by weight of the copolymer of (B) the aromatic vinyl compound-vinyl cyanide compound, and the content of the structural unit derived from the vinyl cyanide compound is 10 to 50 parts by weight of silver, a thermoplastic resin composition for blow molding. In claim 1,
The (B) aromatic vinyl compound-vinyl cyanide compound copolymer is a styrene-acrylonitrile copolymer (SAN) resin for blow molding having a weight average molecular weight different from that of the (C) alpha-methylstyrene copolymer Thermoplastic resin composition. In claim 1,
The (A) diene-based graft copolymer is a thermoplastic resin composition for blow molding having a core-shell structure. In claim 7,
The core is made of butadiene rubber,
The shell is a thermoplastic resin composition for blow molding that is formed by graft polymerization of a copolymer of acrylonitrile and styrene to the core. A molded article using the thermoplastic resin composition for blow molding according to any one of claims 1, 2, and 4 to 8. In claim 9,
A molded article having a heat deflection temperature of 95 to 105°C measured according to ASTM D648.

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