KR20160141432A - Thermoplastic resin composition for vehicle interior material and molded product of vehicle interior material - Google Patents

Abstract

The present invention relates to a thermoplastic resin composition for an automobile interior material, and to a molded article for an automobile interior material. More particularly, the thermoplastic resin composition for an automobile interior material is environment-friendly, and has excellent mechanical properties such as impact resistance, heat resistance, and the like while remarkably reducing the amount of volatile organic compounds generated, by mixing a polycarbonate resin or a recycled polycarbonate resin, and a vinyl copolymer to a styrene-acrylonitrile copolymer and a rubber-modified graft copolymer.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition for automobile interior materials,

The present invention relates to a thermoplastic resin composition for an automobile interior material and an automobile interior material molded article, and more particularly to a styrene-acrylonitrile copolymer and a rubber-modified graft copolymer which are obtained by mixing a polycarbonate resin or a recycled polycarbonate resin with a vinyl copolymer , Which is environmentally friendly, greatly reduces the amount of volatile organic compounds generated, and has excellent mechanical properties such as impact resistance and heat resistance, and relates to a thermoplastic resin composition and automobile interior material molded article for automotive interior materials.

ABS (Acrylonitrile-butadiene-styrene) resin is excellent in practicality due to impact resistance by butadiene rubber polymer and moldability and durability by styrene-acrylonitrile copolymer. . In addition, surface treatment such as plating and coating is easy and applied to various fields, but it has a disadvantage of low heat resistance.

When applied to automotive interiors, such ABS resins are applied with AMS (Alpha Methyl Stryene) or PMI (N-phenylmaleimide) based copolymer to compensate for the heat resistance required according to room temperature rise and component usage characteristics. Respectively. However, when the above-mentioned components are applied, there are problems such as impact resistance and lowering of moldability, and there is a limitation in use such as addition of a compatibilizing agent separately.

On the other hand, in general, in order to be applied to the use of an automobile interior material, besides physical and chemical properties such as heat resistance, chemical resistance and impact resistance, there is a growing demand for resins having low volatile organic compounds (VOCs) have. However, in the case of ABS resin, volatile organic compounds (VOCs) contained in the resin cause an unpleasant smell or generate a chemical that is not good for health, and organic chemicals in the automobile glass are fog ) May cause functional problems such as lowering the transparency of the glass.

Conventional Korean Patent Publication No. 2010-0067223 discloses an environmentally friendly thermoplastic resin composition comprising a recycled polyester resin, a modified aromatic vinyl compound-vinyl cyanide copolymer resin, and an aromatic vinyl-based graft copolymer resin. However, It is difficult to realize a homogeneous physical property due to a variation in reactivity during processing due to application of a reactive compound to increase intermolecular compatibility and it has a disadvantage that it can not be applied to interior parts requiring high heat resistance due to low heat resistance.

In addition, International Publication No. 2014-119827 discloses a polycarbonate-based thermoplastic resin composition containing a polycarbonate resin, a rubber-modified acrylic graft copolymer resin, and a silicone-based compound and having excellent fluidity without deteriorating impact strength and heat resistance However, there is a disadvantage in that heat resistance of automobile parts is lowered due to acrylic graft copolymer and silicone compound having low heat resistance.

Korean Patent Publication No. 2014-0022835 discloses a polymer composition having an improved balance of tensile modulus, impact strength, ductility and flow characteristics, including polycarbonate polymer, inorganic filler and sulfonate salt. However, There is a disadvantage in that the specific gravity is increased and the drawing characteristic and the impact resistance inherent to the resin are lowered.

In Korean Patent No. 1322145, phosphorus flame retardant, nitrogen-based flame retardant and inorganic activator are added to an acrylonitrile-butadiene-styrene (ABS) base resin containing 25 to 50 parts by weight of a recycled thermoplastic resin as a whole Free thermoplastic ABS flame retardant resin composition which contains a halogen-free thermoplastic ABS flame retardant resin composition. However, it has a disadvantage that it is difficult to apply to a part requiring high heat resistance and high impact by using recycled polyethylene terephthalate (PET).

Therefore, it is required to develop a new resin which satisfies physical and chemical properties such as heat resistance, chemical resistance, and impact resistance while having low volatile organic compound characteristics in terms of user convenience and function when applied to automobile parts.

Korea Patent Publication No. 2010-0067223 International Patent Publication No. 2014-119827 Korean Patent Publication No. 2014-0022835 Korea Patent No. 1322145

In order to solve the above-mentioned problems, the present invention relates to a styrene-acrylonitrile copolymer and a rubber-modified graft copolymer which are environmentally-friendly by mixing a polycarbonate resin or a recycled polycarbonate resin and a vinyl copolymer, And the mechanical properties such as impact resistance and heat resistance can be improved. Thus, the present invention has been completed.

Accordingly, an object of the present invention is to provide a thermoplastic resin composition for automotive interior materials that is environmentally friendly and can significantly reduce the amount of volatile organic compounds generated.

Another object of the present invention is to provide an automotive interior material molded article having excellent mechanical properties such as impact resistance and heat resistance.

The present invention relates to a resin composition comprising 10 to 40% by weight of a polycarbonate resin or a recycled polycarbonate resin; 20 to 70% by weight of a styrene-acrylonitrile copolymer; 10 to 40% by weight of a vinyl copolymer; And 10 to 40% by weight of a rubber-modified graft copolymer; and a thermoplastic resin composition for automotive interior materials.

The present invention also provides a molded article of an automobile interior material made of the thermoplastic resin composition for an automobile interior material.

The thermoplastic resin composition for an automobile interior material according to the present invention is produced by mixing a styrene-acrylonitrile copolymer and a rubber-modified graft copolymer with a recycled polycarbonate resin, thereby reducing the processing cost and being eco-friendly. The generation amount of the compound can be greatly reduced.

Further, when the polycarbonate resin, the recycled polycarbonate resin and the vinyl copolymer are mixed with the styrene-acrylonitrile copolymer and the rubber-modified graft copolymer, mechanical properties such as impact resistance and heat resistance are excellent.

Hereinafter, the present invention will be described in more detail with reference to one embodiment.

The present invention relates to a resin composition comprising 10 to 40% by weight of a polycarbonate resin or a recycled polycarbonate resin; 20 to 70% by weight of a styrene-acrylonitrile copolymer; 10 to 40% by weight of a vinyl copolymer; And 10 to 40% by weight of a rubber-modified graft copolymer; and a thermoplastic resin composition for automotive interior materials.

According to a preferred embodiment of the present invention, the polycarbonate resin or the recycled polycarbonate resin is excellent in mechanical properties such as impact resistance and heat resistance and generates little volatile organic compounds (VOCs), and in particular, the recycled polycarbonate resin is an abandoned polycarbonate The recycled resin is eco-friendly and has the advantage of reducing the cost of the process. If the content of the polycarbonate resin or the recycled polycarbonate resin is less than 10% by weight, improvement in heat resistance and impact resistance, which are advantages of the polycarbonate, can not be expected. If the content is more than 40% by weight, Degradation may be caused.

According to a preferred embodiment of the present invention, the styrene-acrylonitrile copolymer has excellent flow properties and can improve moldability during injection molding. The styrene-acrylonitrile copolymer may be prepared by copolymerizing a mixture containing 70 to 80% by weight of styrene and 20 to 30% by weight of acrylonitrile. Specifically, if the content of the acrylonitrile is out of the above range, compatibility with the polycarbonate resin may be deteriorated and physical properties may be deteriorated.

According to a preferred embodiment of the present invention, the styrene-acrylonitrile copolymer may be used in an amount of 20 to 70% by weight. If the content of the styrene-acrylonitrile copolymer is less than 20% by weight, The heat resistance may be lowered.

According to a preferred embodiment of the present invention, the vinyl copolymer may use phenylmaleimide, alpha-methylstyrene or a mixture thereof as a copolymerizable monomer in order to improve heat resistance. Preferably a phenylmaleimide-styrene-maleic anhydride copolymer. The vinyl copolymer may be used in an amount of 10 to 40% by weight. If the content of the vinyl copolymer is less than 10% by weight, improvement in heat resistance can not be achieved, and if it is more than 40% by weight, impact may be deteriorated.

According to a preferred embodiment of the present invention, the rubber-modified graft copolymer is obtained by graft-polymerizing 35 to 60 parts by weight of a monomer mixture of acrylonitrile, styrene or a mixture thereof in 40 to 65 parts by weight of butadiene rubber polymer . Preferably, the monomer mixture is a mixture of 70 to 80% by weight of styrene and 20 to 30% by weight of acrylonitrile.

According to a preferred embodiment of the present invention, the rubber-modified graft copolymer blocks the movement path of cracks in the resin and can be used to reinforce impact resistance. When the content is less than 10% by weight, If it is more than 40% by weight, heat resistance may be deteriorated due to inherent thermal properties.

According to a preferred embodiment of the present invention, a thermoplastic resin composition for automobile interior material is prepared by mixing 1, 2, 3 or 4 selected from the group consisting of dyes, pigments, fillers, stabilizers, light stabilizers, lubricants, antimicrobial agents and mold release agents to control injection moldability, And may further contain more than two kinds of additives.

According to a preferred embodiment of the present invention, the amount of volatile organic compounds (VOCs) generated in the thermoplastic resin composition for an automobile interior material may be 130 ppm or less. In recent years, there has been an increasing demand for resins that generate less volatile organic compounds as the automobile industry and European environmental regulations are strengthened.

Meanwhile, the present invention provides an automotive interior material molded article made of the thermoplastic resin composition for automobile interior material.

Accordingly, the thermoplastic resin composition for automobile interior material according to the present invention can reduce the processing cost by mixing the styrene-acrylonitrile copolymer and the rubber-modified graft copolymer with the polycarbonate resin or the recycled polycarbonate resin, and is environmentally friendly, The amount of volatile organic compounds generated can be greatly reduced. Further, when the polycarbonate resin, the recycled polycarbonate resin and the vinyl copolymer are mixed with the styrene-acrylonitrile copolymer and the rubber-modified graft copolymer, mechanical properties such as impact resistance and heat resistance are excellent.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by the following Examples.

Examples 1 to 4 and Comparative Examples 1 to 6

The following resin compositions were prepared according to the thermoplastic resin composition for automobile interior materials and the contents shown in Table 1 below.

division Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 The polycarbonate resin (A-1) 20 The recycled polycarbonate resin (A-2) 20 40 10 20 20 20 20 The styrene-acrylonitrile copolymer (B-1) 45 45 25 45 50 40 60 52 15 Styrene-acrylonitrile copolymer (B-2) 45 The vinyl copolymer (C) 15 15 15 15 30 30 15 8 45 The rubber-modified graft copolymer (D) 20 20 20 20 20 30 20 20 20 20 (A-1) Polycarbonate resin <Samsung SDI>: polycarbonate resin having MI 13 ± 2 (250 ° C./10 kg)
(A-2) Recycled polycarbonate resin < DG Chem &gt;: MI 14 ± 3 (250 ° C / 10Kg condition)
Suzy
(B-1) styrene-acrylonitrile copolymer <Samsung SDI>: styrene-acrylonitrile copolymer copolymerized from a mixture of acrylonitrile 24 wt% and styrene 76 wt% and having a weight average molecular weight of about 120,000 g / mol coalescence
(B-2) styrene-acrylonitrile copolymer <Samsung SDI>: styrene-acrylonitrile copolymer copolymerized with a mixture of 32% by weight of acrylonitrile and 68% by weight of styrene and having a weight average molecular weight of about 120,000 g / mol coalescence
(C) Vinyl Copolymer < Denka &gt;: A vinyl copolymer (product name: IP MS-NA) having a weight average molecular weight of about 150,000 g / mol was mixed with phenylmaleimide- styrene- maleic anhydride copolymer,
(D) Rubber-Modified Graft Copolymer (Samsung SDI): A rubber-modified polymer obtained by graft-polymerizing 42 parts by weight of a monomer mixture composed of 25% by weight of acrylonitrile and 75% by weight of styrene in 58 parts by weight of butadiene rubber polymer D50) is 270 nm, a core-shell type rubber-modified graft copolymer

Experimental Example: Evaluation of physical properties

A thermoplastic resin composition in the form of a pellet was prepared by extruding / processing a composition obtained by further mixing a stabilizer, a lubricant, an anti-light agent, and a release agent as additives in the thermoplastic resin compositions prepared in Examples 1-4 and Comparative Examples 1-6. At this time, a twin-screw extruder having an L / D of 29 and a diameter of 45 mm was used for the extrusion, and the barrel temperature was set at 250 ° C. The prepared pellets were dried at 80 DEG C for 2 hours, and then molded into a specimen and a door garnish for properties evaluation by setting a cylinder temperature of 250 DEG C and a mold temperature of 60 DEG C using a 60 oz injection molding machine. Using the thus-prepared specimens for evaluation of physical properties and molded articles, the physical properties were evaluated as follows. However, properties such as impact resistance, heat sagging and heat distortion temperature were measured using ASTM specimens. Reliability evaluation such as light resistance and heat resistance was evaluated using door garnish molding products. Respectively.

[Assessment Methods]

It was measured at a load of 18.56 kg _f by the evaluation method described in ASTM D648: (1) Heat distortion temperature (HDT).

(2) Evaluation of heat sagging: The gate part of the specimen for ASTM tensile strength measurement was hanged in a heat sag evaluation fixture (manufactured by Samsung SDI), left in an oven at 85 ± 3 ° C for 3 hours, And the degree of bending of the specimen was measured and evaluated.

(3) Izod Izod: The notched Izod impact strength was measured using a 1/8 inch thick specimen according to the evaluation method described in ASTM D256.

(4) Amount of volatile organic compounds (VOCs) generated: The pellets were volatilized at 120 ° C for 30 minutes using a static head space sampler, and the area of the peak was calculated using GC to calculate the amount of VOCs generated.

(5) Fogging evaluation (mold deposit simulation): 4 g of pellets were placed in a petri dish and heated at 250 ° C for 3 hours, and then the weight of the deposit deposited in the Petri dish lid was measured.

(6) Light fastness evaluation: The surface of the door garnish molded product was post-treated with paint, insert film, and water transfer agent by the method specified in Hyundai Motor's MS210-11, 03 or MS652-12, and the Xenon arc test method specified in SAE J 1885 When the adhesive strength is M-2.5 or more and ΔE is 2.0 or less after irradiating 126 MJ / m ² at 89 ± 3 ° C and 50 ± 5% RH, If not, Fail.

(7) Evaluation of heat resistance: After the surface of the door garnish is coated, the insert film, and the post-treatment process of the mercury transfer, by the method specified in MS210-11, 03 or MS652-12, If the adhesion after the cycle of the standard heat resistance is M-2.5 or more, ΔE is 2.0 or less and the gray scale is the grade 3 or more, it is indicated as Pass, otherwise it is indicated as Fail.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 HDT (° C) 105 105 108 104 104 98 100 104 97 107 Heat sagging (mm) 35 35 30 40 50 55 45 45 57 35 Izod (kgf · cm / cm) 26 25 38 20 10 22 28 18 26 10 VOCs 115 120 105 130 250 320 160 140 180 180 Fogging (ppm) 320 330 300 350 740 860 450 350 400 420 Light resistance evaluation Pass Pass Pass Pass Pass Pass Pass Pass Pass Pass Heat resistance evaluation Pass Pass Pass Pass Pass Fail Fail Pass Fail Pass

According to the results shown in Table 2, in Examples 1 to 4 prepared according to the present invention, the amount of volatile organic compounds generated was as low as 130 ppm or less as compared with Comparative Examples 1 to 6, And heat resistance were both excellent.

Specifically, in the case of Comparative Examples 1 and 2, when a styrene-acrylonitrile copolymer is applied without adding a polycarbonate resin or a recycled polycarbonate resin, heat resistance and impact resistance can be satisfied, It was found that the amount of fogging and the amount of volatile organic compounds generated were high.

In addition, in Comparative Example 3 in which only the recycled polycarbonate resin and styrene-acrylonitrile copolymer were added without applying the vinyl copolymer, it was confirmed that there was a problem that the heat resistance required by the high heat-resistant parts was not satisfied.

In addition, in the case of Comparative Example 4 in which a styrene-acronylate copolymer having an acrylonitrile content of 30 wt% or more was used, it was found that the impact resistance was lowered due to the lower compatibility of the polycarbonate resin and the styrene- there was.

In Comparative Example 5 in which the vinyl copolymer was used in an amount of less than 10% by weight, high heat resistance was not exhibited and the heat resistance was not improved. In Comparative Example 6, which was applied in an amount exceeding 40% by weight, it was confirmed that the impact resistance was deteriorated due to the brittle characteristic.

Therefore, the thermoplastic resin composition for automobile interior materials manufactured in Examples 1 to 4 significantly reduces the amount of volatile organic compounds generated by mixing the polycarbonate resin or the recycled polycarbonate resin and the vinyl copolymer, and at the same time, the mechanical properties such as impact resistance and heat resistance The characteristic has an excellent effect.

Claims (7)

10 to 40% by weight of a polycarbonate resin or a recycled polycarbonate resin;
20 to 70% by weight of a styrene-acrylonitrile copolymer;
10 to 40% by weight of a vinyl copolymer; And
10 to 40% by weight of a rubber-modified graft copolymer;
And a thermoplastic resin composition for automobile interior.
The method according to claim 1,
Wherein the styrene-acrylonitrile copolymer comprises 70 to 80 wt% of styrene and 20 to 30 wt% of acrylonitrile.
The method according to claim 1,
Wherein the vinyl copolymer is selected from the group consisting of phenylmaleimide, alpha-methylstyrene, and mixtures thereof as a copolymerizable monomer.
The method according to claim 1,
Wherein the rubber-modified graft copolymer is obtained by graft-polymerizing 40 to 65 parts by weight of a butadiene rubber polymer and 35 to 60 parts by weight of a monomer mixture comprising acrylonitrile, styrene or a mixture thereof.
The method according to claim 1,
The thermoplastic resin composition for automobile interior material according to claim 1, further comprising at least one additive selected from the group consisting of dyes, pigments, fillers, stabilizers, light stabilizers, lubricants, antimicrobial agents and mold release agents.
The method according to claim 1,
Wherein the thermoplastic resin composition for an automobile interior material has an amount of volatile organic compounds (VOCs) generated of 130 ppm or less.
A molded article of an automobile interior material made of the thermoplastic resin composition for automobile interior material according to any one of claims 1 to 6.