JPH09208796A - Thermoplastic resin composition improved in mold staining - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic resin composition which is excellent in appearance, flexural modulus, tensile elongation, heat resistance, surface hardness and shock resistance and is suitable for injection moldings such as car interior parts items. SOLUTION: One hundred parts by weight of a resin composition comprising (A) 55-75wt.% of propylene-ethylene block copolymer, (B) 0-10wt.% of ethylene- propylene copolymer, (C) 5-15wt.% of ethylene α-olefin copolymer rubber and (D) 15-25wt.% of tale are mixed with (E) 0.05-2 pts.wt. of a hindered amine of the formula (R is a hydrocarbon group of 3 or more carbon atoms such as an ester group) and (F) 0.01-1 pt.wt. of triaryl phosphite and (G) 0.05-4 pts.wt. of a metal salt of the formula: (RCOO)2 X (R is a monovalent hydrocarbon group with a molecular weight of 290-500; X is Zn, Mg, Ca) to provide a thermoplastic resin composition improved in mold staining.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a propylene / ethylene block copolymer, an ethylene / propylene copolymer rubber, an ethylene / α-olefin copolymer resin, talc, and an additive mixture. Good workability at the time, excellent appearance, bending elastic modulus, heat resistance,
The present invention relates to a thermoplastic resin composition having good surface hardness, impact resistance, and tensile elongation, which is suitable for injection-molded articles such as automobile interior parts and the like, which has suppressed mold contamination.

[0002]

2. Description of the Related Art There have been many attempts to improve impact resistance and rigidity by adding ethylene / propylene copolymers, various ethylene copolymers and talc to polypropylene. For example, the compositions described in JP-B-63-42929, JP-A-64-150, JP-A-64-66263, and JP-A-1-204946, which have excellent impact resistance, are known. There is. However, the composition described in Japanese Patent Publication No. 63-42929 does not have sufficient flexural modulus and heat resistance because polypropylene having a significantly high crystallinity is not used. Also, JP-A-64-150, JP-A-64-66263 and JP-A-1
The compositions described in the respective publications of -204946 are suitable for applications such as bumpers due to the low content of talc, but the flexural modulus is significantly insufficient for use as interior materials. is there. In addition, JP-B-4-1593 containing an ethylene / α-olefin copolymer and a large amount of an inorganic filler.
The composition described in Japanese Patent Publication No. 45 is known, but it is not preferable from the viewpoint of having a large specific gravity and reducing the weight of an automobile.

On the other hand, polypropylene-based composite materials containing talc are required to have a very high level of performance in molding and processing, especially at production sites.
During continuous production, it was pointed out that the bleeding material adhered to the mold and the bleeding material clogged in the product appearance, especially the grain of the grain structure, resulting in high product gloss, especially in automobile interior materials. Has been done. Propylene polymers capable of solving such problems and maintaining physical properties are disclosed in JP-A-5-209094 and JP-A-6-17.
Although it has been proposed in Japanese Patent Publication No. 982, there is no mention of a weather-resistant formulation in the publication, and it is still solved in view of the fact that a stabilizer generally used for improving weather resistance adversely affects such a problem. It is the current situation that points are left.

[0004]

DISCLOSURE OF THE INVENTION The present invention has solved such problems and has a high fluidity, excellent moldability, suppressed mold contamination, and excellent physical properties. It is intended to provide a thermoplastic resin composition suitable for an injection molded product such as an automobile interior part including an instrument panel.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that propylene / ethylene having a propylene homopolymer portion having high fluidity and extremely high crystallinity. By mixing the block copolymer with an elastomeric copolymer containing a crystalline segment in the molecule and talc in a specific ratio, high fluidity, excellent moldability, and good physical properties were exhibited. The inventors have found that a thermoplastic resin composition can be obtained, and completed the present invention. That is, in the present invention, the components (A) to (D) below are based on the sum of the components thereof, and the components (E) to (G) below are added to 100 parts by weight of the sum. A thermoplastic resin composition characterized by improved mold contamination. Component (A): The propylene homopolymerization portion has a melt flow rate (MFR) of 15 to 50 g / 10 minutes, an isotactic pentad fraction of 0.97 or more, and a block copolymer MFR of 10 Propylene / ethylene block copolymer having an ethylene content of 2 to 6% by weight of -30 g / 10 min 55 to 75% by weight (B) component: having a melting temperature of 30 to 60 ° C and an MFR of 0.2 to Ethylene / propylene copolymer rubber of 2 g / 10 minutes 0 to 10% by weight (C) component: ethylene / α- having a melting temperature of 60 to 100 ° C. and an MFR of 0.3 to 2 g / 10 minutes Olefin copolymer rubber 5 to 15% by weight (D) component: Talc having an average particle size of 5 μm or less and a specific surface area of 3.5 m ² / g or more 15 to 25% by weight (E) component:

[0006]

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Hindered amine having a structure (R is a hydrocarbon group which may contain an ester group or an ether group having 3 or more carbon atoms) 0.05 to 2 parts by weight (F) Component: Triaryl phosphite 01 to 1 part by weight Component (G): Metal salt represented by the following general formula [I] 0.05 to 4 parts by weight General formula [I] (RCOO) ₂ X (where R in the formula is a molecular weight of 290 to 500) A monovalent hydrocarbon group, X represents Zn, Mg or Ca.)

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION

[I] Component (A) Propylene / ethylene block copolymer ((A)
Component) Physical Properties of Propylene / Ethylene Block Copolymer The propylene / ethylene block copolymer ((A) component) constituting the thermoplastic resin composition of the present invention has a melt flow rate (MFR: 230 ° C., 2.16 kg load). ) Is 1
0 to 30 g / 10 minutes, preferably 12 to 28 g / 10
Min, particularly preferably 15 to 25 g / 10 min. MF of propylene / ethylene block copolymer
When R is less than the above range, the fluidity is insufficient, and a molding machine having a large mold clamping force is required when molding a thin-walled molded product, or it is necessary to raise the molding temperature. It adversely affects productivity. When the MFR of the propylene / ethylene block copolymer exceeds the above range, properties such as impact resistance are insufficient. The MFR of the propylene / ethylene block copolymer was adjusted at the time of polymerization,
Alternatively, it may be prepared with an organic peroxide such as diacyl peroxide or dialkyl peroxide after the polymerization. The ethylene content in the propylene / ethylene block copolymer is 2 to 6% by weight, preferably 3 to 6%.
The content of ethylene in the block copolymer portion is preferably 30 to 50% by weight. When the ethylene content is less than the above range, the heat resistance is poor, and conversely, when the ethylene content exceeds the above range, bending elasticity and surface hardness are insufficient.

The propylene homopolymer portion of the propylene / ethylene block copolymer has an MFR of 15 to
50 g / 10 min, preferably 17 to 45 g / 10 min, particularly preferably 20 to 40 g / 10 min, and its isotactic pentad fraction is 0.97 or more, preferably 0.975 or more, and particularly preferably. 0.98 to 0.99. When the MFR of the propylene homopolymer portion in the propylene / ethylene block copolymer is less than the above range, the compound material has a low MFR and the moldability is poor, and when the MFR exceeds the above range, the impact resistance is low. It becomes defective. Further, if the isotactic pentad fraction (P) of the propylene homopolymer portion in the propylene / ethylene block copolymer is less than the above range, the flexural modulus is insufficient, which is not suitable. The isotactic pentad fraction (P) is the isotactic fraction in the pentad unit in the polypropylene molecular chain measured by ¹³ C-NMR.

Of propylene / ethylene block copolymer
Production A highly stereoregular catalyst is used in the production of the propylene / ethylene block copolymer. As a production example of the highly stereoregular catalyst, a titanium trichloride composition obtained by reducing titanium tetrachloride with an organoaluminum compound and further treating it with various electron donors and electron acceptors, and an organoaluminum compound And a method of combining with an aromatic carboxylic acid ester (JP-A-56-100806, JP-A-5
No. 6-120712, JP-A-58-104907), and a method of a supported catalyst in which titanium tetrachloride and various electron donors are contacted with magnesium halide (JP-A-57-63310). JP-A-63-43915
And Japanese Patent Laid-Open No. 63-83116). In the presence of the above catalyst, by applying a manufacturing process such as a gas phase fluidized bed, a solution method, a slurry method,
It can be obtained by block-copolymerizing propylene and ethylene.

Blending ratio The blending amount of the propylene / ethylene block copolymer is 55 to 75 based on the total amount of the components (A) to (D).
It is important that the content is wt%, preferably 56 to 70 wt%, particularly preferably 60 to 70 wt%. If the content is less than the above range, the flexural modulus will be poor, and conversely, if it exceeds the range, the impact resistance will be reduced.

(B) Ethylene / Propylene Copolymer Rubber (Component (B)) Physical Properties of Ethylene / Propylene Copolymer Rubber The ethylene / propylene copolymer rubber ((( Component B) has a melt flow rate (MFR: 230 ° C., 2.16 kg load) of 0.2 to 2 g / 10 minutes, preferably 0.3 to 1.
An ethylene / propylene copolymer rubber having a weight of 5 g / 10 minutes is used. If the MFR of the above copolymer rubber is less than the above range, the impact strength is lowered. On the contrary, when the amount exceeds the above range, the product has a high gloss, which is unsuitable for a product requiring a matte appearance.

Further, it is important that the ethylene / propylene copolymer rubber has an appropriate amount of crystalline segments in the molecule, and a differential scanning calorimeter (DSC: Differen) is used.
tial scanning calorimeter
r) measured at 30-60 ° C, preferably 35-55
A material having a melting temperature of ℃, particularly preferably 40 to 50 ℃ is used. When the melting temperature is less than the above range, the crystallinity is low and the surface hardness is insufficient. On the other hand, if the content exceeds the above range, the impact resistance is insufficient, so that it becomes unsuitable. The ethylene / propylene copolymer rubber having a propylene content of 12 to 30% by weight, particularly 15 to 25% by weight is preferable from the viewpoint of impact resistance and surface hardness. This ethylene / propylene copolymer rubber has ethylidene norbornene, 1,4 as the third component.
-Hexadiene, dicyclopentadiene and the like may be used. The ethylene / propylene copolymer rubber does not have to be one type, and may be a mixture of two or more types.

Production of Ethylene / Propylene Copolymer Rubber The above ethylene / propylene copolymer rubber is the above (A).
Like the components, in the presence of a Ziegler type catalyst, an ionic polymerization catalyst such as Phillips type catalyst, a gas phase fluidized bed, a solution method,
It is obtained by applying a manufacturing process such as a slurry method to copolymerize ethylene and propylene, and optionally by adding a third component.

Blending Ratio The blending amount of the above ethylene / propylene copolymer rubber is 0 to 10% by weight, preferably 2 to 10% by weight in the thermoplastic resin composition.
It is important to contain 8% by weight, particularly preferably 3 to 6% by weight. If the blending amount exceeds the above range, the surface hardness tends to decrease.

(C) Ethylene / α-olefin Copolymer Rubber (Component (C)) Physical Properties of Ethylene / α-Olefin Copolymer Rubber Ethylene / α-constituting the thermoplastic resin composition of the present invention
The olefin copolymer rubber ((C) component) is a differential scanning calorimeter (DSC: Differential Scann).
ing Calorimeter) 60 ~
100 ° C., preferably 65-90 ° C., particularly preferably 7
A material having a melting temperature of 0 to 80 ° C. is used. When the melting temperature is less than the above range, the crystallinity is low and the surface hardness is insufficient. On the contrary, if it exceeds the above range, the impact resistance becomes insufficient. Further, the melt flow rate (MFR:
230 ° C, 2.16 kg load) is 0.3 to 2 g / 10
Min, preferably 0.4 to 1.9 g / 10 min. If the MFR is less than the above range, IZO
D Physical properties such as impact are deteriorated. On the contrary, if the content exceeds the above range, the effect of improving the impact resistance decreases.

The α-olefin copolymerizable with ethylene is a terminal olefin compound having 4 to 12 carbon atoms, preferably 4 to 8 carbon atoms, specifically 1-butene, 3-methyl-1-butene, 1-butene. Pentene, 1-hexene, 1-heptene, etc. can be mentioned. Among these, a copolymer with 1-butene is particularly preferable because it has an excellent balance of impact strength, tensile elongation and surface hardness. These copolymerized α-
The olefin does not have to be one type, and may be a multi-component copolymer using a mixture of two or more types in some cases. In the case of such a multi-component copolymer, it has 4 to 12 carbon atoms.
In addition to the above α-olefin, propylene can also be used. The density of the ethylene / α-olefin copolymer rubber is less than 0.90 g / cm ³ , particularly 0.87.
From the viewpoint of impact resistance and surface hardness, it is more preferable that the content is from 0.89 g / cm ^{3 to} 0.89 g / cm ³ . The ethylene / α-olefin copolymer rubber does not have to be one type, and may be a mixture of two or more types.

Of ethylene / α-olefin copolymer rubber
Production The ethylene / α-olefin copolymer rubber is produced by applying a production process such as a gas phase fluidized bed, a solution method and a slurry method in the presence of an ion polymerization catalyst such as a Ziegler type catalyst and a Phillips type catalyst to produce ethylene and It can be obtained by copolymerizing an α-olefin. It is sufficient that the melting temperature is within the above range regardless of the content of α-olefin. The content of this α-olefin is 5 to 25% by weight,
Particularly, 17 to 23% by weight is preferable from the viewpoint of impact resistance and surface hardness.

Blending ratio The blending amount of the above ethylene / α-olefin copolymer rubber is 5 to 15% by weight, preferably 6 to 13% by weight, particularly preferably 8 to 12% by weight in the thermoplastic resin composition. It is important to include it. If the blending amount is less than the above range, the impact resistance is lowered, and conversely, if it exceeds the above range, the surface hardness is lowered.

(D) Talc (Component (D)) Physical Properties of Talc Talc ((D) which constitutes the thermoplastic resin composition of the present invention
(Component), the average particle size is 5 μm or less, preferably 0.5 to 3 μm, and the specific surface area is 3.5 m ² / g.
As described above, it is preferably 3.5 to ⁶ m ² / g. If these are out of the above range, the impact resistance is lowered, so that it is unsuitable. The average particle size is determined from the particle size value at a cumulative amount of 50% by weight read from a particle size cumulative curve measured by a liquid layer sedimentation type light transmission method (for example, CP type manufactured by Shimadzu Corporation). To be The measurement of the specific surface area is obtained from the measurement value by an air permeation method (for example, SS-100 type constant pressure ventilation type specific surface area measuring device manufactured by Shimadzu Corporation). Further, these talcs are generally produced by dry pulverization and then dry classification. Talc is various organic titanate coupling agents, silane coupling agents, fatty acids, for the purpose of improving the adhesiveness or dispersibility with the polymer.
You may use what was surface-treated with fatty acid metal salt, fatty acid ester, etc.

Blending ratio The blending amount of talc is 15 to 25% by weight, preferably 17 to 23% by weight. If the blending amount of talc is less than the above range, the flexural modulus is insufficient, and if it exceeds the above range, the specific gravity becomes too large.

(E) Hindered amine component ((E) component) The thermoplastic resin composition of the present invention contains a weathering agent.

[0023]

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A hindered amine having a structure (R is a hydrocarbon group which may have an ester group or an ether group having 3 or more carbon atoms) is used. This hindered amine is preferably a hindered amine having a tetramethylpiperidyl structure, and specifically, [4- (4-hydroxy-3,5-di-t-butylphenyl) propionyl] -N- (4-hydroxy-). 3,5-Di-t-butylphenyl) methyl-2,2,6,6-tetramethylpiperidine, [4- (4-hydroxyphenyl) propionyl] -N- (4-hydroxy-3,5-di- t-butylphenyl) methyl-2,2,6,6-tetramethylpiperidine, [4- (4-hydroxyphenyl) propionyl] -N- (4-hydroxyphenyl) methyl-2,
2,6,6-tetramethylpiperidine, poly- (N-β
-Hydroxyethyl-2,2,6,6-tetramethyl-
4-hydroxy-piperidyl succinate) and the like. Among these hindered amine compounds, [4- (4-hydroxy-3,5-di-t-butylphenyl) propionyl] -N- (4-hydroxy-
3,5-di-t-butylphenyl) methyl-2,2
6,6-Tetramethylpiperidine, Poly- (N-β-hydroxyethyl-2,2,6,6-tetramethyl-4-
(Hydroxy-piperidyl succinate) is particularly preferable in that weather resistance can be exhibited without contaminating the mold.

The amount of the hindered amine-based stabilizer compounded is 0.05 based on 100 parts by weight of the components (A) to (D).
˜2 parts by weight, preferably 0.08 to 0.5 parts by weight, particularly preferably 0.1 to 0.3 parts by weight. If the blending amount exceeds the above range, it adversely affects the mold contamination, and conversely,
If it is less than the above range, the practical weather resistance is deteriorated.

(F) Triaryl phosphite component ((F) component) In the thermoplastic resin composition of the present invention, triaryl phosphite is used as an antioxidant. Examples of the triaryl phosphite include triphenyl phosphite, trisnonyl phenyl phosphite, tris dinonyl phenyl phosphite, and tris- (pt
-Butylphenyl) phosphite, tris- (2,4
-Di-t-butylphenyl) phosphite and the like can be mentioned. Among these compounds, tris- (2,4-di-t-butylphenyl) phosphite or the like is preferably used from the viewpoints of hydrolysis resistance, processing stability at high temperature, and mold contamination prevention. The amount of the triaryl phosphite compounded is 0.01 to 1 part by weight, preferably 0.01 to 0. 0, based on 100 parts by weight of the components (A) to (D).
5 parts by weight, particularly preferably 0.01 to 0.15 parts by weight. If the blending amount exceeds the above range, the mold contamination is adversely affected. On the contrary, if the blending amount is less than the above range, the stability during molding is deteriorated.

(G) Metal Salt Component (Component (E)) In the thermoplastic resin composition of the present invention, a metal salt represented by the following general formula [I] is used as a dispersant. General formula [I] (RCOO) ₂ X (wherein R represents a monovalent hydrocarbon group having a molecular weight of 290 to 500, preferably 290 to 400, and X represents Zn, Mg or Ca.) The metal salt Is used as a talc dispersant and a pigment dispersant when coloring, and in order to highly prevent mold contamination, it is important to use the metal salt represented by the above general formula [I]. If the molecular weight of R is less than the above range, the mold is likely to be contaminated. On the other hand, if it exceeds the above range, the dispersibility of talc or pigment is poor.

Concretely, calcium behenate, magnesium behenate, zinc behenate, zinc montanate, calcium montanate, magnesium montanate, calcium melicinate, magnesium mericinate, zinc melicinate, calcium serotiate, serotic acid. magnesium,
Examples thereof include zinc serotiate, calcium lignocerate, magnesium lignocerate, and zinc lignocerate. Among these metal salts, it is preferable to use calcium behenate, magnesium behenate, zinc behenate, zinc montanate, magnesium montanate, calcium montanate, and the like. The amount of these metal salts blended is
0.05 to 4 with respect to 100 parts by weight of the components (A) to (D)
It is preferably 0.1 to 2 parts by weight, particularly preferably 0.2 to 1 part by weight. If the blending amount exceeds the above range, the mold contamination is adversely affected. On the contrary, if the blending amount is less than the above range, the dispersibility of the pigment, talc and the like is insufficient and the physical properties are adversely affected.

(H) Additional component (optional component) The thermoplastic resin composition of the present invention includes the above (A) to (G).
In addition to the above essential components, additional components other than the above can be added within a range that does not significantly impair the effects of the present invention. Examples of such additional components ((H) component) include phenolic antioxidants, quinacridone, perylene, phthalocyanine, carbon black and other coloring substances, fibrous potassium titanate, fibrous magnesium oxysulfate, fibrous aluminum borate. , Whiskers such as calcium carbonate,
Materials such as carbon fiber and glass fiber can be exemplified. [II] Method for producing thermoplastic resin composition (1) Kneading In the thermoplastic resin composition of the present invention, the above components are used in a conventional extruder, Banbury mixer, roll, Brabender plastograph, kneader, etc. It is produced by kneading at room temperature, but of these, it is preferable to use an extruder, particularly a twin-screw extruder. (2) Molding Processing The molding processing method of the thermoplastic resin composition of the present invention is not particularly limited, but from the viewpoint of the effect of the invention exhibited, it is most suitable to use the injection molding method. .

[III] Thermoplastic Resin Composition (1) Physical Properties The thermoplastic resin composition of the present invention produced by the above-mentioned method has good processability during injection molding, excellent appearance, and flexural modulus. The following physical properties can be exhibited, which are excellent in impact resistance, tensile elongation, surface hardness, and heat resistance, and in which the mold stain resistance is suppressed. (A) MFR: 8 g / 10 minutes or more, preferably 9
g / 10 minutes or more, (b) flexural modulus: 20,000 kg / cm ² or more,
Preferably 21,000 kg / cm ² or more, (c) Izod impact value (23 ° C.): 1
5 kg · cm / cm or more, preferably 17 kg · cm /
cm or more, (d) Tensile elongation: 200% or more, preferably 210
% Or more, (e) Heat distortion temperature: 120 ° C. or more, preferably 125
℃ or more, (f) Rockwell hardness: 70 or more, preferably 74
As described above, (g) Gloss: 55% or less, preferably 48% or less, and when the thermoplastic resin composition of the present invention is used to mold a molded product with a mold that is surface-textured for low gloss. It is preferable that the amount of change in gloss of the die-textured portion is 1.0 or less after 2,000 shot molding.

(2) Applications It is possible to process various molded products because it is a material capable of exhibiting the above-mentioned physical properties. Above all, injection molded products such as automobile interior material parts, particularly instruments. It is preferably molded into panels, door trims, console boxes, various pillar materials, and the like.

[0032]

The present invention will be described more specifically with reference to the following experimental examples. [I] Measuring Method (1) MFR: Based on ASTM-D1238, it was measured at a temperature of 230 ° C. under a load of 2.16 kg. (2) Isotactic pentad fraction (P): ¹³
Macromolecule, 8, using C-NMR
687 (1975). (3) Melting temperature: Differential scanning calorimeter (DSC: Di
differential Scanning Calori
and melt the sample by heating it up to a temperature of 180 ° C. at a rate of 10 ° C./min to −100 ° C.
It was cooled to the temperature of 10 ° C., then heated at a rate of 20 ° C./min, and read from the peak position of the obtained thermogram.

(4) Flexural Modulus: ASTM-D79
The bending speed at 23 ° C. was 2 mm / min. (5) Impact resistance: In accordance with ASTM-D785,
It was evaluated by the Izod impact value at 23 ° C. (6) Tensile elongation: In accordance with ASTM-D638,
A tensile test was performed at 23 ° C. at a speed of 10 mm / min to measure the elongation rate. (7) Surface hardness: According to ASTM-D785,
The Rockwell hardness at 23 ° C. was evaluated on the R scale. (8) Heat distortion temperature (HDT: Heat Deform)
ation Temperature): AST
Based on M-D523, it measured with a 4.6 kg load.

(9) Gloss: ASTM-D52
According to 3, the measurement was performed under the condition of an incident angle of 60 degrees. (10) Mold Contamination: A mold having a depth of 180 to 220 μm and an overall texture of 0.5 to 15 μm for matting, 350 mm × 100 m.
When a test piece with a shape of m × 3 mmt is molded for 2,000 shots, the change in the gloss of the die-textured portion between the first shot and the 2,000th shot is measured, and the change amount is 1.0 or less. Was judged to be ◯, and a case of exceeding 1.0 was judged to be ×. (11) Weather resistance: Fade meter (Suga Test Instruments Co., Ltd. FAL-AU-H type tester, black panel 83
Under conditions (° C., no rain), those in which cracks occurred within 1,000 hours were evaluated as x, and those that did not occur were evaluated as o.

[II] Experimental Examples Examples 1 to 21 and Comparative Examples 1 to 21 The raw materials shown in Tables 1 to 7 were blended in the composition ratios shown in Tables 8 and 9, and tetrakis [ Methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane (trade name “RA1010” manufactured by Ciba-Geigy Co., Ltd.) was blended at a ratio of 0.1 parts by weight, and these were mixed. 5 with Kawada Manufacturing Super Mixer
After mixing for 2 minutes, use an FCM twin-screw kneader manufactured by Kobe Steel Ltd. 2
A thermoplastic resin composition was obtained by kneading and granulating at a set temperature of 10 ° C. After that, various test pieces were prepared at an injection molding machine with a mold clamping force of 100 tons at a molding temperature of 210 ° C. and measured according to the above-mentioned various measuring methods, and the evaluation results are shown in Table 1.
0 and Table 11. Regarding the mold contamination, the above test piece was continuously pressed by a molding machine with a mold clamping pressure of 265 tons for 2,000.
0 shot molding was performed and evaluation was performed according to the above-mentioned measuring method. Furthermore, about Examples 1-8, 10,0
Molding was performed up to 00 shots and the rate of change in gloss was measured. The rate of change was 1.0 or less. The evaluation results are shown in Tables 10 and 11.

[0036]

[Table 1]

[0037]

[Table 2]

[0038]

[Table 3]

[0039]

[Table 4]

[0040]

[Table 5]

[0041]

[Table 6]

[0042]

[Table 7]

[0043]

[Table 8]

[0044]

[Table 9]

[0045]

[Table 10]

[0046]

[Table 11]

[0047]

The thermoplastic resin composition of the present invention has a propylene / ethylene block copolymer, an ethylene / propylene copolymer rubber, an ethylene / α-olefin copolymer resin, talc, and a specific compound. Since it is composed of additives, it has good processability during injection molding, excellent appearance, good bending elastic modulus, impact resistance, tensile elongation, heat resistance, surface hardness, and mold contamination resistance. It can be preferably used for the suppressed injection-molded articles such as automobile interior parts.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08K 5/3432 C08K 5/3432 5/524 5/524 // (C08L 53/00 23:08) (72) Inventor Yuki Hana 1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Chemical Co., Ltd., Yokkaichi Research Institute (72) Inventor Ikuo Tsutsumi 1, Toho-cho, Yokkaichi-shi, Mie Mitsubishi Chemical Co., Ltd. ) Inventor Hiroki Sato 1 Toho-cho, Yokkaichi-shi, Mie Mitsubishi Chemical Co., Ltd. Yokkaichi Research Institute

Claims (3)

[Claims] 1. The following components (A) to (D) are based on the sum of the components, and the following (E) is added to 100 parts by weight of the sum.
A thermoplastic resin composition having improved mold stain resistance, which is characterized by containing (G) component. Component (A): The propylene homopolymerization portion has a melt flow rate (MFR) of 15 to 50 g / 10 minutes, an isotactic pentad fraction of 0.97 or more, and a block copolymer MFR of 10 Propylene / ethylene block copolymer having an ethylene content of 2 to 6% by weight of -30 g / 10 min 55 to 75% by weight (B) component: having a melting temperature of 30 to 60 ° C and an MFR of 0.2 to Ethylene / propylene copolymer rubber of 2 g / 10 minutes 0 to 10% by weight (C) component: ethylene / α- having a melting temperature of 60 to 100 ° C. and an MFR of 0.3 to 2 g / 10 minutes Olefin copolymer rubber 5 to 15% by weight (D) component: Talc having an average particle size of 5 μm or less and a specific surface area of 3.5 m ² / g or more 15 to 25% by weight (E) component: ] Hindered amine having a structure (R is a hydrocarbon group which may have an ester group or an ether group having 3 or more carbon atoms) 0.05 to 2 parts by weight (F) component: triaryl phosphite 0.01 to 1 Parts by weight (G) component: Metal salt represented by the following general formula [I] 0.05 to 4 parts by weight General formula [I] (RCOO) ₂ X (wherein R in the formula is a monovalent having a molecular weight of 290 to 500). Hydrocarbon group, X represents Zn, Mg or Ca.) 2. The composition has an MFR of 8 g / 10 minutes or more,
Flexural modulus at 23 ° C is 20,000 kg / cm ²
Above, Izod impact value of 15kg · cm / cm or more,
The thermoplastic resin composition according to claim 1, which has a tensile elongation of 200% or more, a heat deformation temperature of 120 ° C. or more, and a Rockwell hardness of 70 or more. 3. When a molded product is molded with a mold that is surface-textured for the purpose of low gloss, the amount of change in gloss of the mold-textured part is 1.0 or less after 2,000 shot molding. The thermoplastic resin composition according to claim 1, which is