KR101843937B1 - Polyester resin composition - Google Patents

Abstract

(화학식 1에서, n은 14~18의 정수이다),
(d) 산화방지제 및 표면 성능 개선제로 하기 화학식 2로 표시되는 산성피로인산나트륨 0.1 중량% 내지 1 중량% 및
<화학식 2>

(e) 탈크 20 중량% 내지 30 중량%를 포함하는 폴리에스테르 수지 조성물에 관한 것이다.(B) 10 to 20% by weight of a polyethyleneterephthalate resin; (c) a polybutylene terephthalate resin represented by the following formula 0.1 to 0.5% by weight of a branched fatty ester expressed by 1,
&Lt; Formula 1 >

(In the formula (1), n is an integer of 14 to 18)
(d) 0.1% to 1% by weight of an acidic pyrophosphate represented by the following formula (2) as an antioxidant and a surface performance improver; and
(2)

(e) 20 to 30% by weight of talc.

Description

[0001] POLYESTER RESIN COMPOSITION [0002]

The present invention relates to a polyester resin composition, and more particularly to a polyester resin composition which is improved in mechanical properties, thermal stability, surface characteristics, paintability and vapor deposition so as to be suitable for a material for a head lamp bezel for an automobile, &Lt; / RTI &gt;

Generally, a mixture of polycarbonate resin, polybutylene terephthalate and polybutylene terephthalide and polyethylene terephthalate is used as a material for automobile headlamp bezel.

Automotive headlamps have different rising temperatures when lighting depending on design structure, type of bulb or other factors. When automobile head lamps are turned on, resins with high heat resistance are used as they rise to high temperatures. Therefore, a mixture of polybutylene terephthalate and polyethylene terephthalate having relatively high heat resistance is widely used.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile head lamp bezel, and more particularly, to an automobile head lamp bezel.

Since a bezel molded product is injection-molded at high speed, it is preferable to use a material having low gas generation and good surface characteristics.

Further, in the BACK-END PROCESS, after the coating and deposition processes are performed, high adhesion between the molded product, the coating, and the deposition material is required.

Further, in the head lamp assembly process, it is necessary to use a material having excellent ductility in order to prevent the parts of the head lamp from breaking or cracking during assembly.

In this example, inert inorganic metal salts of a nucleating agent and a crystal growth agent, montanic acid, and other paraffin were used to improve the moldability of the resin.

In addition, alkyl silane or alkylate silane, silane epoxide, montan wax and heat resistance agent were added to the mixture of PBT and polyethylene terephthalate in order to improve surface characteristics and secondary processability of the automobile headlamp.

However, in the related art, when the automobile head lamp is turned on, there is a problem that the microreaction material is generated in the resin due to the rising temperature. Such a migration material is solidified on the inner surface of the automobile headlamp lens and has a problem of lowering the light transmittance of the automobile headlamp.

In order to solve this problem, researches have been sought on techniques for improving the surface characteristics and vapor deposition properties of automobile headlamps.

An invention such as that disclosed in Korean Patent Laid-Open Publication No. 2000-0040679 (name of the invention: aromatic polyester resin composition) has been proposed as a conventional technique.

Disclosure of the Invention The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide a resin composition for a headlamp bezel which is improved in mechanical properties, thermal stability, surface characteristics, paintability, And an ester resin composition.

In order to solve the above problems, the present invention provides a resin composition comprising (a) 44.5 to 69.7% by weight of a polybutylene terephthalate resin; (b) 10 to 20% by weight of a polyethylene terephthalate resin; (c) 0.1% to 0.5% by weight of a branched fatty ester represented by the following formula (1) as an internal lubricant;

&Lt; Formula 1 >

(In the above formula (1), n is an integer of 14 to 18)

(d) 0.1% by weight to 1% by weight of an acidic pyrophosphate represented by the following formula (2) as an antioxidant and a surface performance improver; And

(2)

(e) 20 to 30% by weight of talc.

In addition, the intrinsic viscosity of the polybutylene terephthalate resin (a) may be 0.7 to 1.2 dl / g.

The intrinsic viscosity of the polyethylene terephthalate resin (b) may be 0.45 to 1 dl / g.

The polyester resin composition may further comprise an antioxidant, a heat stabilizer, a lubricant, a pigment, a light stabilizer, and at least one additive selected from a moisture release agent.

The additive may be added in an amount of 0.1% by weight to 5.0% by weight based on the total weight of the polyester resin composition.

It is also possible to provide a molded article for an automobile headlamp bezel molded using a polyester resin composition.

The polyester resin composition according to the present invention can provide a thermoplastic polyester resin composition for automobile headlamp bezel improved in mechanical properties and heat resistance.

In addition, the present invention can provide a thermoplastic polyester resin composition excellent in paintability and vapor deposition property so as to conform to the surface characteristics required for an automobile headlamp bezel.

In addition, the present invention has an effect of reducing the occurrence of haze of the automobile headlamp bezel.

Hereinafter, the description of the present invention with reference to the drawings is not limited to a specific embodiment, and various transformations can be applied and various embodiments can be made. It is to be understood that the following description covers all changes, equivalents, and alternatives falling within the spirit and scope of the present invention.

In the following description, the terms first, second, and the like are used to describe various components and are not limited to their own meaning, and are used only for the purpose of distinguishing one component from another component.

Like reference numerals used throughout the specification denote like elements.

As used herein, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It is also to be understood that the terms &quot; comprising, "" comprising, "or" having &quot;, and the like are intended to designate the presence of stated features, integers, And should not be construed to preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to Table 1 and Table 2 attached hereto.

The present invention describes a thermoplastic polyester resin composition suitable for automotive headlamp bezels.

The thermoplastic polyester resin composition according to an embodiment of the present invention comprises (a) 44.5 to 69.7% by weight of a polybutylene terephthalate resin, (b) 10 to 20% by weight of a polyethylene terephthalate resin %, (c) 0.1 to 0.5% by weight of a branched fatty ester represented by the following formula (1) as an internal lubricant,

&Lt; Formula 1 >

(In the above formula (1), n is an integer of 14 to 18)

(d) 0.1% to 1% by weight of an acidic pyrophosphate represented by the following formula (2) as an antioxidant and a surface performance improver; and

(2)

(e) 20% to 30% by weight of talc.

(a) Polybutylene terephthalate ( Polybutylene 테레피thalate , PBT) resin

The polybutylene terephthalate (PBT) resin, which is a base resin in the polyester resin composition of the present invention, has a unit represented by Chemical Formula 3 and has a melting temperature of about 215 ° C to 235 ° C.

(3)

(Wherein n is an average degree of polymerization in the range of 50 to 200)

Considering the workability and mechanical properties of the polybutylene terephthalate resin, the polybutylene terephthalate resin (a) preferably has an intrinsic viscosity (IV) of 0.7 to 1.2 dl / g . The polybutylene terephthalate resin (a) preferably has an Intrinsic Viscosity (IV) of 0.8 to 1.1 dl / g.

Further, the content of the polybutylene terephthalate resin may be 44.5% by weight to 69.7% by weight based on the whole polyester resin composition.

When the content of the polybutylene terephthalate resin is less than 44.5% by weight, the solidification rate may be delayed during injection molding, which may lead to a problem of a prolonged cycle time. Further, when the content of the polybutylene terephthalate resin exceeds 69.7% by weight, there is a problem that a relatively large amount of post-deformation occurs.

(b) Polyethylene terephthalate ( Polyethyleneterephthalate ) Suzy

In the polyester resin composition of the present invention, the polyethylene terephthalate resin is represented by the general formula (4), and the melting temperature is about 255 ° C to 265 ° C.

&Lt; Formula 4 >

(In the formula (4), n represents an integer of 1 or more, preferably an integer of 40 to 160. When considering the processability and mechanical properties of the polyethylene terephthalate resin,

The polyethyleneterephthalate resin (b) preferably has an intrinsic viscosity (IV) of 0.45 to 1.0 dl / g. It is most preferable that the polyethylene terephthalate resin (b) has an intrinsic viscosity (IV) of 0.5 to 0.8 dl / g.

The content of the polyethylene terephthalate resin may be 10% by weight to 20% by weight based on the whole polyester resin composition.

If the content of the polyethylene terephthalate resin is less than 10% by weight, the surface quality of the injection-molded product may deteriorate. When the content of the polyethylene terephthalate resin is more than 20% by weight, the solidification rate may be lowered, resulting in lower productivity and lower heat resistance.

(c) Internal lubricant

The polyester resin composition of the present invention includes a branched fatty acid ester having 14 to 18 carbon atoms, which is a compound represented by the general formula (1) as an internal lubricant.

The internal lubricant can reduce the shearing force in the extrusion process of the resin and facilitate the kneading.

The content of the internal lubricant may be 0.1% by weight to 0.5% by weight based on the whole polyester resin composition.

When the content of the internal lubricant is less than 0.1% by weight, it may be difficult to serve as a lubricant. If the content of the internal lubricant is more than 0.5% by weight, the residual amount of the internal lubricant may be discharged to the surface of the molded article during injection molding, which may result in deterioration of surface characteristics.

(d) Antioxidant and surface performance improving agent

The polyester resin composition of the present invention includes an acidic sodium pyrophosphate represented by the general formula (2) to improve the heat resistance and surface properties.

The content of the acidic sodium pyrophosphate compound may be 0.1% by weight to 1% by weight based on the total polyester resin composition.

If the content of the acidic sodium pyrophosphate compound is less than 0.1% by weight, the effect of improving the heat resistance and surface properties to be achieved may be insignificant. When the content of the acidic sodium pyrophosphate compound exceeds 1% by weight, the mechanical properties are deteriorated.

(e) Talc

The polyester resin composition of the present invention may contain talc to variously adjust and improve mechanical strength and heat resistance.

The content of talc may be 20% by weight to 30% by weight based on the total polyester resin composition. If the content of talc is less than 20% by weight, mechanical rigidity and heat resistance characteristics may be deteriorated. When the content of the talc exceeds 30% by weight, the mechanical brittleness is remarkably lowered and the surface gloss is lowered.

In addition, the polyester resin composition according to the embodiment of the present invention may further contain an antioxidant, a heat stabilizer, a lubricant, a pigment, a light stabilizer, and at least one additive selected from an iodine releasing agent to the extent that the object of the present invention is not impaired can do. In this case, the additive is preferably added in an amount of 0.1% by weight to 5.0% by weight based on the total weight of the polyester resin composition.

Example  1 to 4 and Comparative Example  1 to 4

The components used in Examples 1 to 4 and Comparative Examples 1 to 4 of the present invention are as follows, and the respective contents are as shown in Table 1.

(a) Polybutylene terephthalate resin (TRIBIT 1500, Samyang Corp.) having an intrinsic viscosity of 0.84 dl / g,

(b) Polyethyleneterephthalate resin (SB CHIP, Huvis) having an intrinsic viscosity of 0.64 dl / g,

(c) Fatty acid methyl ester (Loxiol EP861, manufactured by HENKEL) as an internal lubricant.

(d) Sodium pyrophosphate (SAPP, YONEYAM KAGAKU KOUGYO KAISYA) as antioxidant and surface improving agent,

(e) Talc (KCM-6300, KOCH; Median Particle Size (占 퐉): 6 max)

The molding process of the polyester resin composition of the present invention is as follows.

(A) a polybutylene terephthalate resin (TRIBIT 1500, Samyang Corp.) having an intrinsic viscosity of 0.84 dl / g, (b) a polybutylene terephthalate resin having an intrinsic viscosity of 0.64 dl / g (C) Fatty acid methyl ester (Loxiol EP 861, HENKEL) as an internal lubricant; and (d) an antioxidant and a surface performance improver as acid fatigue Sodium Phosphate (SAPP, YONEYAM KAGAKU KOUGYO KAISYA) is uniformly mixed and dispersed with a Henschel mixer. Thereafter, it is introduced into the primary inlet of a twin-screw extruder (specification: L / D = 40, diameter = 25 (mm)). (E) Talc (KCM-6300, KOCH; Median Particle Size (μm): 6 max) was charged into the secondary inlet (side inlet) of the secondary extruder and the extrusion temperature was adjusted to 245 to 275 ° C And extruded at a screw rotating speed of 150 to 250 rpm to form pellets.

If the extrusion temperature is higher than 275 ° C, the possibility of thermal decomposition of the polyester resin increases, which may result in deterioration of mechanical properties and other physical properties. If the extrusion temperature is less than 245 ° C, the melt viscosity of the resin is low, and friction heat due to the shearing force may be generated to cause excessive migration of the polyester resin composition.

The pellets thus prepared were set at a cylinder temperature of 250 ° C to 280 ° C and a mold temperature of 70 ° C, and injection molding of specimens was conducted under the conditions of an injection pressure of 80 kgf / cm 2.

Table 1 shows the results of evaluation of the properties of the polybutylene terephthalate (a), the polyethylene terephthalate (b), the internal lubricant (c), and the polyoxyalkylene terephthalate of Examples 1 to 4 and Comparative Examples 1 to 4 prepared in the molding step of the above- (D) and talc (e) content of the surface active agent.

[Table 1]

The physical properties, haze, paintability and vapor deposition properties of the specimens molded according to the above-described Examples 1 to 4 and Comparative Examples 1 to 4 were measured by the following methods.

- Intrinsic viscosity: ASTM D2857 [phenol / tetrachloroethane (50:50 weight ratio), 25 C]

- Flow Index: (MI): ASTM D1238 (270 DEG C, 2.16 kg)

- Tensile strength: ASTM D638

- Flexural Strength and Modulus: ASTM D790

- Heat distortion temperature (HDT): ASTM D648 (18.6 kgf / cm 2)

- Haze: ASTM D1003 (23 ± 2 ° C, 50 ± 5%)

- Durability: A rectangular specimen with an area of 8 * 8 (WxH) cm and a thickness of 3 mm was molded and coated with a primary hard coating agent, and the coating was evaluated for uniformity of coating on the specimen.

- Deposition property: The actual automobile headlamp bezel was molded and the surface of the molded product was coated with a hard coating agent first. Thereafter, aluminum was deposited in a vacuum state. Then, with a sharp blade, the deposition surface is cut into 11 rows and 11 rows at regular intervals of 1 mm, and 100 squares having an area of 1 mm 2 are formed. The prepared sample was evaluated by observing the degree of surface delamination with a square piece of water which was peeled apart while attaching a prescribed adhesive tape. When the number of pieces of rectangular pieces to be peeled off from the adhesive tape is 5 or less, it is represented by the best (⊚). When the number of pieces is 6 to 10, excellent (∘) and when it is 11 or more, good (△).

High temperature Under the environment  In resin Migration  Material evaluation

The degree of the migration material contained in the resin under the high-temperature environment of the specimen molded according to the above-described Examples 1 to 4 and Comparative Examples 1 to 4 was compared and evaluated. For this purpose, a disk specimen on a 6 cm diameter sheet was produced using an injection molding machine LGH-100N (LS Cable). The prepared specimens were cut to a width of 2 mm and a length of 2 mm. 5 g of the specimens were placed in a glass chalet having a glass cover with a diameter of 50 mm and allowed to stand for 5 hours on a hot plate at 160 ° C. (± 1 ° C.) After that, the degree of haze due to the condensed migration material in the chalet glass cover was evaluated using a haze meter.

Table 2 shows the results of the measured physical properties as described above.

[Table 2]

As shown in Table 2, the compositions of Examples 1 to 4 exhibited less haze while maintaining mechanical properties, and were excellent in paintability and vapor deposition properties, as compared with the compositions of Comparative Examples 1 to 4.

Particularly, when a compound composed of a polyphosphoric acid and a disodium salt was added as an antioxidant and a surface performance improving agent in all the compositions of the Examples, the occurrence of haze was reduced, and paintability and vapor deposition properties were excellent.

On the other hand, Comparative Examples 3 and 4 have many haze hazards and poor paintability and vapor deposition properties, making them unsuitable as materials for implementing final products.

In another embodiment, the polyester resin composition of Examples 1 to 4 may further contain a polyamide, polycarbonate, polyacetal, polyphenylene oxide, polyphenylene sulfide, polyarylate, polyamide, polyimide, poly At least one resin selected from the group consisting of polyimides having a phenyl trimethyl indene structure, polysulfone, polyether sulfone, polyether ketone, polyether ether ketone, polyaramid, polyether nitrile and polybenzimidazole May be mixed or dissolved in the polyester resin composition.

In this case, the blending amount of the additive [F] is preferably 0.5 to 5% by weight in the polyester resin compositions of Examples 1 to 4.

When the amount of the additive [F] is less than 0.5% by weight, the effect of improving the vapor deposition property of the polyester resin composition may be insignificant. Further, when the amount of the additive [F] is more than 5% by weight, there is a problem that the glass transition temperature (Tg) is lowered.

As described above, it can be confirmed that the polyester resin composition according to the present invention has excellent paintability and vapor deposition property. In addition, the polyester resin composition according to the present invention has less haze and is suitable for use as a material for an automobile headlamp bezel.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be clear to the person.

In addition, since the components shown in the drawings can be enlarged or reduced for convenience of description, the present invention is not limited to the size and the shape of the components shown in the drawings, Those skilled in the art will appreciate that various modifications and equivalent embodiments are possible. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims (6)

(a) 44.5 wt.% to 69.2 wt.% polybutylene terephthalate resin;
(b) 10 to 20% by weight of a polyethylene terephthalate resin;
(c) 0.1 to 0.5% by weight of a branched fatty acid ester represented by the following formula (1) as an internal lubricant;
&Lt; Formula 1 >

(In the above formula (1), n is an integer of 14 to 18)
(d) 0.1% by weight to 1% by weight of an acidic pyrophosphate represented by the following formula (2) as an antioxidant and a surface performance improver; And
(2)

(e) 20% to 30% by weight of talc;
Polyimide, polyetherimide, polyimide having a phenyltrimethylindene structure, polysulfone, polyether sulfone, polyether sulfone, polyether sulfone, polyether sulfone, polyether sulfone, , An additive [F] comprising at least one resin selected from the group consisting of polyether ketone, polyether ether ketone, polyaramid, polyether nitrile and polybenzimidazole is mixed or dissolved,
Wherein the additive [F] is 0.5 wt% to 5 wt%.
The method according to claim 1,
Wherein the polybutylene terephthalate resin (a) has an intrinsic viscosity of 0.7 to 1.2 dl / g.
The method according to claim 1,
Wherein the polyethyleneterephthalate resin (b) has an intrinsic viscosity of 0.45 to 1 dl / g.
The method according to claim 1,
The above-mentioned polyester resin composition,
An antioxidant, a heat stabilizer, a lubricant, a pigment, a light stabilizer, and at least one additive selected from moisture release.
5. The method of claim 4,
Preferably,
0.1 to 5.0% by weight based on the total weight of the polyester resin composition.
A molded article for an automobile headlamp bezel molded using the polyester resin composition according to any one of claims 1 to 5.