KR20150078902A - Polyester Resin Composition - Google Patents

Abstract

The present invention relates to a polyester resin composition, and more specifically, to a polyester resin composition comprising: 100 parts by weight of a basic resin including 80 to 95 parts by weight of a polybuthyleneterephthalate (PBT) resin, and 5 to 20 parts by weight of polycarbonate (PC); 0.1 to 0.5 parts by weight of aluminum particles based on 100 parts by weight of the basic resin; and 0.1 to 0.5 parts by weight of carbon black, thereby showing excellent surface properties, mechanical properties, thermal resistance stability, and dimensional stability needed for a bezel of a headlamp in a vehicle.

Description

TECHNICAL FIELD [0001] The present invention relates to a polyester resin composition,

The present invention relates to a polyester resin composition which can be used for automotive interior and exterior materials, in particular, bezel parts of automobile headlamps.

The bezel parts of automobile headlamps are generally made of polybutylene terephthalate resin or polycarbonate resin, but in the market mainly polybutylene terephthalate resin is molded into a hardened surface mold to deposit aluminum on the surface of the product, It is common to make.

However, the conventional method has a disadvantage that the defect rate due to aluminum deposition is somewhat present and the manufacturing cost is high.

Accordingly, development of a resin composition capable of exhibiting mechanical properties and surface characteristics suitable as a bezel component of an automobile headlamp has been demanded.

The present invention aims to provide a polyester resin composition which can exhibit excellent surface properties, mechanical properties, heat resistance stability and dimensional stability required for a bezel of an automobile head lamp.

Accordingly, the present invention provides, as a first preferred embodiment, 100 parts by weight of a base resin containing 80 to 95% by weight of polybutylene terephthalate (PBT) and 5 to 20% by weight of a polycarbonate resin (PC) 0.1 to 0.5 parts by weight of aluminum particles per 100 parts by weight of the base resin; And 0.1 to 0.5 parts by weight of carbon black.

The polybutylene terephthalate resin according to the embodiment may have an intrinsic viscosity of 0.8 to 1.2 dl / g and a viscosity average molecular weight (Mv) of 15,000 to 35,000 in the polycarbonate resin.

The aluminum particles according to the embodiment may be in the form of a powder having a size of 10 to 30 탆 or a master batch.

The carbon black according to the embodiment may have a size of 10 to 50 μm.

The present invention also provides, as a second preferred embodiment, a molded article produced from the polyester resin composition.

The polyester resin composition according to the present invention exhibits excellent surface properties, mechanical properties, heat resistance and dimensional stability at the same time and can be applied to a bezel of an automobile head lamp.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a resin composition comprising 100 parts by weight of a base resin comprising 80 to 95% by weight of a polybutylene tererephthalate (PBT) and 5 to 20% by weight of a polycarbonate resin (PC); 0.1 to 0.5 parts by weight of aluminum particles per 100 parts by weight of the base resin; And 0.1 to 0.5 parts by weight of carbon black.

[Basic Resin]

In the present invention, the base resin may include 80 to 95% by weight of polybutylene tererephthalate (PBT) and 5 to 20% by weight of a polycarbonate resin (PC).

The polybutylene terephthalate (PBT) resin can be produced by condensation polymerization through direct esterification reaction or transesterification reaction using butanediol and terephthalic acid or dimethyl terephthalate as monomers.

The PBT resin may have an intrinsic viscosity of 0.8 to 1.2 dl / g. When the intrinsic viscosity of the PBT resin is less than 0.8 dl / g, the overall mechanical property of the resin composition may deteriorate and flowability may be increased. If it is more than 1.2 dl / g, processing due to decrease in flowability during injection molding may be difficult due to high viscosity.

In this case, the intrinsic viscosity (?) Can be measured at 20 占 폚 using a Ureter-type viscosity tube after the sample to be measured is dissolved in methylene chloride.

The content of the PBT resin may be 80 to 95% by weight of the base resin. If the content of the PBT resin is less than 80% by weight, mechanical properties and thermal properties may be deteriorated. If the amount of the PBT resin is more than 95% Crystallization may result in deterioration of dimensional stability.

The polycarbonate (PC) resin may be an aromatic polycarbonate resin produced by an interfacial polycondensation reaction of bisphenol A and phosgene.

The PC resin may have a viscosity average molecular weight (Mv) of 15,000 to 35,000. If the viscosity average molecular weight of the PC resin is less than 15,000, the impact strength may be deteriorated. If the viscosity is more than 35,000, the flowability may be deteriorated.

The viscosity average molecular weight was determined by dissolving the polycarbonate pellet in methylene chloride and measuring the intrinsic viscosity [?] Of the resultant filtrate at 20 ° C using a Ubero type viscometer and then measuring the intrinsic viscosity [?] Can be calculated using equation

[?] = 1.23 X 10 ^ (-5) X Mv ^ (0.83)

If the content of the PC resin is less than 5% by weight, it may be difficult to ensure dimensional stability. If the content of the PC resin is more than 20% by weight, the thermal property may be deteriorated. have.

[Aluminum particles]

In the present invention, the aluminum particles may be contained in the composition to exhibit the metallic texture of the surface.

The aluminum particles are made of pure aluminum and are in the form of a powder having a size of 10 to 30 mu m or a master batch, and various particle sizes exist. If the particle size is less than 10 mu m, the metal texture may not be well developed, resulting in deterioration of physical properties. When the particle size is larger than 30 mu m, It may be difficult to exhibit the desired particle texture. At this time, the size of the aluminum particles means the longest length in the cross section.

The content of the aluminum particles may be 0.1 to 0.5 parts by weight based on 100 parts by weight of the base resin. If the content of the aluminum particles is less than 0.1 parts by weight, the metallic particles may not be expressed as intended, The mechanical properties may deteriorate and the cost may increase.

[Carbon black]

In the present invention, carbon black can be used as a black pigment. In general, carbon black exists in various diameters ranging from 1 nm to 1 mm, and the particles may exist in the form of a spherical shape in which several particles are aggregated.

If the size of the carbon black is less than 10 mu m, the aggregation of particles may occur and dispersion may be difficult. If the particle size is more than 50 mu m, a black pigment having high gloss This can be difficult.

The content of the carbon black may be 0.1 to 0.5 parts by weight based on 100 parts by weight of the base resin. If the content of the carbon black is less than 0.1 parts by weight, it may be difficult to exhibit black color. If the content is more than 0.5 parts by weight, mechanical properties may be deteriorated.

[additive]

The polyester resin composition according to the present invention may further contain additives according to the required characteristics.

The additive may be at least one selected from the group consisting of heat stabilizers, antioxidants, light stabilizers, mold release agents, compatibilizers, dyes, pigments, colorants, nucleating agents, plasticizers, impact modifiers, stabilizers and lubricants.

The antioxidant may be at least one selected from the group consisting of a phenol type, a phosphite type, a thioether type, and an amine type antioxidant.

The releasing agent may be at least one member selected from the group consisting of a fluorine-containing polymer, a silicone oil, a metal stearate, a montanic acid metal salt, a montanic ester wax, and a polyethylene wax.

[Manufacturing method]

Each component of the present invention can be applied to a compounding process for producing a molding chip by melting, kneading and extruding using an extruder to produce a polyester resin composition. In order to maximize the kneading of the composition, the mixer may be manufactured by kneading at 240 to 260 캜 using a twin-screw extruder. Further, the residence time can be minimized in order to prevent thermal decomposition of the composition during melt-kneading, and it is necessary to adjust the screw rotation speed in consideration of dispersibility in the composition, and can be carried out at a rotation speed of about 200 to 300 rpm .

The polyester resin composition according to the present invention has excellent surface properties, mechanical properties, thermal stability and dimensional stability. Specifically, it has an impact strength of 30 to 40 J / m (Izod 2.75 J) and a tensile strength of 500 to 700 kgf / , A heat distortion temperature (HDT) of 150 to 200 ° C, and a shrinkage ratio of 1.6 to 1.9%. The polyester resin composition according to the present invention exhibiting such characteristics can be applied to a bezel of an automobile head lamp.

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are only for describing the present invention in more detail and that the scope of the present invention is not limited by these embodiments.

Example  One

Each component was melted and kneaded in a twin-screw extruder heated to 240 to 260 ° C according to the composition shown in the following Table 1, and then a polyester resin composition was prepared in a chip state and dried at 120 ° C. for 5 hours using a dehumidifying dryer And dried.

Example  2 and Example  3

A polyester resin composition was prepared in the same manner as in Example 1 except that the content of PET resin and PC resin was changed.

Example  4 and Example  5

A polyester resin composition was prepared in the same manner as in Example 1, except that the content of aluminum particles was changed.

Example  6 and Example  7

A polyester resin composition was prepared in the same manner as in Example 1 except that the content of carbon black was changed.

Comparative Example  One

A polyester resin composition was prepared in the same manner as in Example 1, except that PET resin was used as a base resin.

compare Yes  2 and Comparative Example  3

A polyester resin composition was prepared in the same manner as in Example 1 except that the content of PET resin and PC resin was changed.

compare Yes  4 and Comparative Example  5

A polyester resin composition was prepared in the same manner as in Example 1, except that the content of aluminum particles was changed.

compare Yes  6 and Comparative Example  7

A polyester resin composition was prepared in the same manner as in Example 1 except that the content of carbon black was changed.

Impact strength, tensile strength, heat distortion temperature, mold shrinkage and surface properties were measured for the specimens of the polyester resin compositions prepared in Examples and Comparative Examples, and the results are shown in Table 2.

(1) Impact strength

A 1/4 inch specimen was prepared according to ASTM D256 and the Izod Notched impact strength was measured at room temperature (23 ° C).

(2) Tensile strength

A 1/8 inch dumbbell specimen was prepared according to ASTM D638 and the tensile strength measurement rate was set at 5 mm / min.

(3) Heat deformation temperature

A 1/4 inch specimen was prepared according to ASTM D648 and measured under a load of 0.45 MPa (4.6 kgf / cm 2).

(4) Mold Shrinkage

A disk mold having a diameter of 10 cm and a thickness of 3.2 mm was manufactured and evaluated according to ASTM D955.

(5) Surface properties

The polyester resin composition was used to examine the surface color and graininess of a specimen produced by a screw extruder with the naked eye, and the surface characteristics were evaluated on the basis of the following criteria.

Good: Surface color is black and aluminum is felt

Bad: Surface color is not black and aluminum is not felt

division Base resin (100 parts by weight) Aluminum particles
(Parts by weight) Carbon black
(Parts by weight) PET resin
(weight%) PC resin
(weight%) Example 1 90 10 0.3 0.3 Example 2 80 20 0.3 0.3 Example 3 95 5 0.3 0.3 Example 4 90 10 0.1 0.3 Example 5 90 10 0.5 0.3 Example 6 90 10 0.3 0.1 Example 7 90 10 0.3 0.5 Comparative Example 1 100 0 0.3 0.3 Comparative Example 2 75 25 0.3 0.3 Comparative Example 3 98 2 0.3 0.3 Comparative Example 4 90 10 0 0.3 Comparative Example 5 90 10 1.0 0.3 Comparative Example 6 90 10 0.3 0 Comparative Example 7 90 10 0.3 1.0

Impact strength
(J / m) The tensile strength
(kgf / cm2) Heat distortion temperature
(° C) Mold Shrinkage
(%) Surface property Example 1 35 590 163 1.7 O Example 2 42 510 151 1.6 O Example 3 32 610 172 1.8 O Example 4 36 590 162 1.7 O Example 5 31 600 165 1.7 O Example 6 36 600 162 1.7 O Example 7 31 610 166 1.7 O Comparative Example 1 28 640 185 2.2 O Comparative Example 2 45 480 145 1.5 O Comparative Example 3 30 630 180 2.1 O Comparative Example 4 36 600 161 1.7 X Comparative Example 5 28 620 165 1.7 O Comparative Example 6 36 590 160 1.7 X Comparative Example 7 29 610 164 1.7 O

As a result of measurement of physical properties, as shown in Table 2,

When PET alone was used as the base resin as in Comparative Example 1, the impact strength was lowered and the molding shrinkage ratio was found to be larger.

As in Comparative Example 2, when the amount of the PET resin in the base resin is less than the proper amount and the amount of the PC resin is more than the proper amount, the tensile strength and the heat distortion temperature are lowered. On the contrary, When the content is less than the proper amount, the molding shrinkage ratio is increased.

Also, as in Comparative Example 4, when the aluminum particles were less than the proper amount, the surface properties were not good, and when the aluminum particles were more than the proper amount as in Comparative Example 5, the impact strength was lowered.

Also, as in Comparative Example 6, when the content of carbon black was less than the proper amount, the surface properties were not good, and when the content of carbon black was more than the proper amount as in Comparative Example 7, the impact strength was decreased.

On the other hand, the polyester resin composition of the examples shows that all the components are used in an appropriate amount and exhibit excellent impact strength, tensile strength, heat distortion temperature, mold shrinkage and surface characteristics.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereto will be. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (5)

100 parts by weight of a base resin containing 80 to 95% by weight of polybutylene terephthalate (PBT) and 5 to 20% by weight of a polycarbonate resin (PC);
With respect to 100 parts by weight of the base resin,
0.1 to 0.5 parts by weight of aluminum particles; And
0.1 to 0.5 parts by weight of carbon black. The method of claim 1, wherein
The polybutylene terephthalate resin has an intrinsic viscosity of 0.8 to 1.2 dl / g,
Wherein the polycarbonate resin has a viscosity average molecular weight (Mv) of 15,000 to 35,000. The method of claim 1, wherein
Wherein the aluminum particles are in a powder form or a master batch form having a size of 10 to 30 占 퐉. The method of claim 1, wherein
Wherein the carbon black has a size of 10 to 50 占 퐉. A molded article produced from the polyester resin composition according to any one of claims 1 to 4.