KR101876021B1 - Polypropylene composition with excellent surface appearance and scratch resistance - Google Patents

Abstract

The present invention relates to a high-crystalline polypropylene resin, a rubber component and an inorganic filler comprising a block copolymer having a polydispersity index (PI) of 5 or more, a micro talc having an average particle diameter of 0.5 to 0.1 탆, a compatibilizer, The present invention relates to a polypropylene resin composition excellent in appearance and scratch resistance.
Also, the resin composition according to the present invention is excellent in terms of processability such as moldability and cycle time, and can be suitably used as a bumper, a side seal molding, a garnish, Widely applicable to parts.

Description

TECHNICAL FIELD [0001] The present invention relates to a polypropylene resin composition having excellent appearance and scratch resistance. [0002] POLYPROPYLENE COMPOSITION WITH EXCELLENT SURFACE APPEARANCE AND SCRATCH RESISTANCE [

The present invention relates to a polypropylene resin composition which can be used for an automobile exterior material, which comprises a highly crystalline polypropylene resin including a block copolymer having a polydispersity index (PI) of 5 or more, an inorganic filler having a rubber component and a different size, And to a polypropylene resin composition excellent in appearance and scratch resistance characteristics including a predetermined amount of scratch additive of a newly synthesized silica master batch.

BACKGROUND ART Polypropylene resin compositions that are widely used for automotive exterior materials mainly include bumper, side seal molding, garnish, and the like. Recently, It is a tendency to digest the design.

Especially, in the case of exterior parts that do not paint, various embosses can be applied to the surface in order to express a good appearance. Especially, it has a vulnerability that can easily be damaged by scratches due to external factors.

The present invention relates to a polypropylene resin composition having such excellent appearance and excellent properties of scratch resistance.

Korean Unexamined Patent Publication No. 2004-0008806 discloses a polypropylene resin composition, which can be used for polypropylene, a rubber component, an inorganic component and the like, which can be developed without any difficulty in ensuring dimensional stability or moldability. However, A separate scratch additive is required.

However, the scratch characteristics of the scratch additive can be easily improved as the content of the scratch additive increases, but it generally has a bad influence on appearance factors such as occurrence of surface stains.

Therefore, there is a need for a polypropylene resin composition which can simultaneously realize appearance and scratch resistance.

1: Korean Patent Publication No. 2004-0008806

Accordingly, the present inventors have found that by simultaneously adjusting the particle size of the inorganic material for reinforcing stiffness and the compatibility of the compatibilizer with polypropylene as the organic material and optimizing the content thereof, The scratch characteristics were all excellent. Also, it was found that the compatibilizer used in this study should be able to control the molding flow according to the whole part structure and optimizing the general molding flow scale.

Accordingly, an object of the present invention is to provide a polypropylene resin composition which can simultaneously realize appearance and scratch resistance.

In order to solve the above problems, the present invention provides a cemented carbide comprising at least one member selected from the group consisting of high crystalline homopolypropylene and block copolymer polypropylene having an isotactic peptad fraction of 96% or more by the C ¹³ -NMR method 30 to 88% by weight of a qualitative polypropylene resin; 1 to 30% by weight of a rubber component; 1 to 15% by weight of an inorganic filler; 10 to 25% by weight of fine talc having an average particle size of 0.5 to 0.1 탆; 0.1 to 3.0% by weight of a compatibilizer; And 0.1 to 3.0% by weight of an scratch additive comprising peroxide and maleic anhydride in a resin composition comprising a polypropylene resin and a silicone oil, the polypropylene resin composition having excellent appearance and scratch resistance to provide.

The resin composition according to the present invention can easily satisfy the component requirement characteristics by improving the surface appearance characteristics of the parts and dramatically improving the scratch resistance.

In addition, in the injection molding process of existing parts, it is possible to achieve the same or further improvement in terms of processability such as moldability and cycle time in comparison with the conventional resin composition.

In addition, mold release agent for mold release is minimized, appearance stain is minimized, and there is no problem in long term heat resistance or durability performance. The compatibilizer is used to optimize the molecular weight of modified polypropylene using maleic anhydride, It can be easily increased to improve miscibility with the main component polypropylene and to improve the scratch resistance.

Therefore, the resin composition according to the present invention can be widely applied to exterior components such as bumper, side seal molding, garnish, and the like.

1 shows the scratch resistance evaluation results of Comparative Example 5 (left) and Example 5 (right).

Hereinafter, the present invention will be described in detail.

The polypropylene resin composition for use in the conventional exterior component includes a main component including a rubber component including a polypropylene resin, an ethylene-octene rubber (EOOR) and an ethylene butene rubber (EBR) An excessive amount of a scratch additive in a silicone system and a slip agent have been used. However, when the scratch additive and the slip agent are mixed in an excessive amount, the scratch resistance is excellent, but the occurrence of unevenness on the appearance is easy, resulting in a poor surface appearance.

In the present invention, a microcrystalline talc having an average particle diameter of 0.5 to 0.1 탆 and a novel scratch additive are added to a high-crystalline polypropylene resin, a rubber component and an inorganic filler containing a block copolymer having a polydispersity index (PI) , A polypropylene resin composition excellent in appearance and scratch resistance properties can be realized. In addition, a compatibilizer for improving the organic-inorganic interface property is applied, thereby improving the scratch resistance and improving the surface appearance of the component.

Specifically, the present invention relates to (A) 30 to 88% by weight of a highly crystalline polypropylene resin; (B) 1 to 30% by weight of a rubber component; (C) 1 to 15% by weight of an inorganic filler; (D) 10 to 25% by weight of fine talc having an average particle size of 0.5 to 0.1 탆; (E) 0.1 to 3.0% by weight of a compatibilizing agent; And (F) 0.1 to 3.0 wt% of a scratch additive.

The highly crystalline polypropylene resin (A) comprises at least one member selected from the group consisting of highly crystalline homopolypropylene and block copolymer polypropylene having an isotactic peptad fraction of 96% or more by the C ¹³ -NMR method, Polypropylene, which is the basis for minimizing the overall mineral content, uses high crystallinity. By using a highly crystalline polypropylene resin, the amount of inorganic matter can be reduced by 1 to 2% compared with the conventional method, thereby contributing to improvement of scratch resistance. The highly crystalline propylene resin is preferably used in an amount of 30 to 88% by weight. When the amount of the highly crystalline propylene resin is less than 30% by weight, the polypropylene resin composition has a physical property limit. Particularly, the polypropylene resin composition exhibits limited physical properties in stiffness. When the amount of the propylene resin is more than 88% by weight, It is difficult to achieve the above-mentioned target and it is preferable to use it within the above range.

The highly crystalline polypropylene resin preferably includes a block copolymer having a polydispersity index (PI) of 5 or more. When a block copolymer having a high molecular weight distribution having a PI of 5 or more is used in the polypropylene resin, the flow characteristics are excellent and the appearance characteristics can be improved.

The highly crystalline polypropylene resin has a melt index of 1 to 110 g / 10 min and is selected from the group consisting of polypropylene homopolymers, propylene-ethylene copolymers, 1-butene copolymers of propylene, propylene 1 hexene copolymers, and propylene 4 methyl 1 pentene copoly Reamers, and random copolymers can be included.

The rubber component (B) is preferably at least one member selected from the group consisting of an amorphous ethylene -olefin copolymer and a styrene-based thermoplastic elastomer. By this, it is possible to obtain an appropriate flexibility and to exhibit impact strength characteristics such as low- It is possible to improve. Specifically, there is at least one selected from the group consisting of propylene, butene 1, pentene 1, hexane 1, octene 1, 4-methylpentene 1 and heptene 1 as the? -Olefin component. Examples of the styrene-based thermoplastic elastomer include styrene- Ethylene-butene-styrene copolymer (SEBS) is mainly used. More preferably ethylene-octadiene or ethylene-butadiene or mixtures thereof.

When the amount of the rubber component is less than 1 wt%, the impact strength of the rubber component is limited. When the amount of the rubber component is more than 30 wt%, the impact property is improved. However, That is, the flexural modulus of elasticity is limited.

The inorganic filler (C) is preferably at least one selected from the group consisting of nano clay, glass fiber, talc, mica, calcium carbonate, wollastonite, barium sulfate, and magnesium sulfate whisker, Simultaneous use exhibits the most desirable performance.

Thus, the talc used in the present invention is a general talc having an average particle size of 3 to 6 탆 which is generally used. In addition, it is preferable to use fine talc having an average particle size of 0.5 to 0.1 mu m to be used together with the general talc. More preferably 0.6 to 0.8 mu m. By using the inorganic filler having different sizes, it is possible to manifest the effect of maximizing the rigidity such as the flexural modulus by adjusting the inorganic particle size for reinforcing stiffness.

Next, the compatibilizer (E) is obtained by grafting an unsaturated carboxylic acid or an acid anhydride to a polypropylene monolith or a polypropylene copolymer in an amount of 0.7 to 1.2% by weight and a melt index of 100 to 120 g / 10 min , 2.16 kg), it is possible to improve the miscibility with the polypropylene which is the main component and to improve the scratch resistance characteristics. More preferably, modified polypropylene using maleic anhydride is used.

When the graft ratio is less than 0.7 wt%, the polarity of the modified polypropylene is limited. When the graft ratio is more than 1.2 wt%, the polarity is good and the affinity with the inorganic material is good. However, When the melt index is less than 100 g / 10 min (230 DEG C, 2.16 kg), the maleic anhydride functional group having polarity is limited in compatibility to show affinity with an inorganic substance, When the index is less than 120 g / 10 min (230 DEG C, 2.16 kg), compatibility is good, but the flexural modulus is lowered.

At this time, the compatibilizer is preferably 0.1 to 3.0 wt%, and when it is less than 0.1 wt%, there is a limit in compatibility between the inorganic material and the polymer, and when it exceeds 3.0 wt%, the physical properties are lowered.

The scratch additive (F) is a novel synthetic silica containing peroxide and maleic anhydride in a resin composition containing a polypropylene resin and a silicone oil in order to improve the scratch performance and the appearance of the parts. (sillica) is used. In this case, it is preferable to use the scratch additive in an amount of 0.1 to 3% by weight. When the amount of the scratch additive is less than 0.1% by weight, scratch resistance is limited. When the amount exceeds 3% by weight, Because there is a limit, it is used within the above-mentioned range. This minimizes migration to the part surface and minimizes the slip agent content for mold release in the mold, minimizing component surface smudge prevention.

Specifically, the scratch-resistant additive is prepared by adding 0.03 to 0.1 phr of peroxide to 100 phr of a resin composition containing 50 to 70 wt% of polypropylene resin and 30 to 50 wt% of silicone oil and 1 to 10 phr of maleic anhydride, It is recommended to use a master batch prepared by mixing 2 phr. When the peroxide is less than 0.03 phr, there is a limit to the generation of radicals of the polypropylene which should be modified. When the amount of the peroxide is more than 0.1 phr, there is a limit in adjusting the MI due to the generation of too much radicals. In the case of less than 1 phr of maleic anhydride, There is a limit to the content. If the content exceeds 2 phr, there is a possibility of occurrence of discoloration or the like of the unreacted residual mononer. Therefore, it is preferable to use within the above range.

In addition, the resin composition of the present invention may contain, in addition to the above components, at least one additive selected from the group consisting of colorants, reinforcing materials, long-term heat stabilizers, weather stabilizers, antistatic agents, lubricants, nucleating agents and flame retardants of inorganic pigments or organic pigments It can be added within a range not contrary to the object of the invention.

The thus-prepared resin composition of the present invention can simultaneously realize not only mechanical stiffness but also appearance and scratch resistance, so that it can be widely used for parts for automobile exterior materials.

Hereinafter, the present invention will be described in more detail with reference to examples. However, these examples are for illustrating the present invention, and the scope of the present invention is not limited thereto.

Example  1 to 6 and Comparative Example  1 to 8

A polypropylene resin composition according to an embodiment of the present invention will be described together with a comparative example. In this example, in principle, the specimens were subjected to standard tests and the specimens were prepared by injection molding. The kneading extruder is manufactured by preliminary kneading by measuring the amount of each component in a diameter of 32 mm (L / D, 40: 1) manufactured by SM Platech. All of the examples and comparative examples were dried in a 90 oven for 3 hours in consideration of attenuation of physical properties due to moisture absorption in the composition.

The dried composition was injected using a Si180-III (mold force = 180 ton) injection machine manufactured by Toyo Co., Ltd., and the injection temperature was 180/200/200/210/210 in the order of nozzle in the feed hopper, Was molded at 60 ° C at 100 bar, and molded articles for physical property measurement and test pieces for appearance test evaluation were prepared.

Table 6 below shows the components used in Examples and Comparative Examples. Table 1 shows homopolymers and block copolymers of high crystallinity as base resins for the resin composition. Some of the products exhibited the properties of polypropylene having a controlled molecular weight distribution, Table 2 shows rubber components, Table 3 shows the specifications of the inorganic filler used and Table 4 shows the compatibilizer and scratch additive.

Component (A): Polypropylene resin Sample No. Flow Index [g / 10 min]
(230 DEG C, 2.16 Kg) PI ¹⁾
(230 DEG C) Weight average molecular weight
[g / mol] Isotactic Peptid Fraction ²⁾ PP Homo-1 10 3.5 230,000 97.2 PP Block-1 22 3.7 210,000 96.4 PP Block-2 60 5.9 189,000 96.9 PP Block-3 100 2.8 155,000 96.5 1) Poly dispersity index (PI) is a measure of molecular weight distribution as a cross over point of G '(loss modulus), G' (storage modulus) as a rheological property.
2) Isotactic Peptid Fraction Determined by C13-NMR.

Component (B): Rubber component Sample No. Flow index
[g / 10 min]
(190 DEG C, 2.16 Kg) Density [Kgf / cm3] etc Rubber-1 1.0 0.857 C2-C8 copolymer elastomer Rubber-2 10.2 0.867 C2-C8 copolymer elastomer

Component (C) and component (D): inorganic filler and fine talc Sample No. Sample classification Size [탆] Filler-1 Talc Average diameter: 3 to 6 Filler-2 Fine talc Average diameter: 0.65

Component (E) and Component (F): compatibilizer and scratch additive Sample No. Sample classification Condition Compatibilizer Modified polypropylene (PP-g-MA) MI: 105 DEG C (230 DEG C, 2.16 Kg)
MA graft ratio: 0.7 to 1.2 wt% My scratch
additive Synthetic silica master batch (Synthesized Silica M / B) ¹⁾ MI: 10 DEG C (230 DEG C, 2.16 Kg) 1) Synthesized Silica M / B is prepared by mixing peroxide 0.05 Phr (parts / Hunres) and 1.5 Phr maleic anhydride per 60% by weight of polypropylene + 40% by weight of silicone oil (Silicone oil) It is.

Composition and content (unit: wt%) of the polypropylene resin compositions of Comparative Examples 1 to 8 division Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Comparative Example 7 Comparative Example 8 The polypropylene resin (A) PP Homo-1 15 15 14 13 10 10.5 15 15 PP Block-1 15 15 15 15 20 20 - - PP Block-2 25 25 25 25 23 22 - - PP Block-3 - - - - - - 45 42 Rubber component (B) Rubber-1 5 5 5 5 7.5 7.5 - - Rubber-2 10 10 10 10 7.5 7.5 10 10 The fillers (C) and (D) Filler-1 30 10 10 10 30 30 10 10 Filler-2 - 20 20 20 - - 20 20 The compatibilizer (E) - - One - - 0.5 - One Scratch Additives (F) - - - 2 2 2 - 2 Quantity 100 100 100 100 100 100 100 100

Composition and content (unit: wt%) of the polypropylene resin compositions of Examples 1 to 6 division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 The polypropylene resin (A) PP Homo-1 12 10 7 6.5 4 15 PP Block-1 15 20 - - - - PP Block-2 25 22.5 45 45 45 20 PP Block-3 - - - - - 22 Rubber component (B) Rubber-1 5 7.5 - - - - Rubber-2 10 7.5 15 15 15 10 The fillers (C) and (D) Filler-1 10 10 10 10 10 10 Filler-2 20 20 20 20 20 20 The compatibilizer (E) One 0.5 One 1.5 3 One Scratch Additives (F) 2 2 2 2 3 2 Quantity 100 100 100 100 100 100

Experimental Example : Measurement of physical properties

The physical properties of the molded articles for physical property measurement and appearance evaluation test pieces prepared according to Examples 1 to 6 and Comparative Examples 1 to 8 were measured by the following methods, and the results are shown in Table 9 below.

The physical properties shown in Table 9 are the average values except for the upper limit value and the lower limit value of seven specimens measured, and the test method is as follows.

(1) Melt index: Measured at 230 캜 according to ASTM D 1238.

(2) Tensile strength: Measured according to ASTM D 639. The measurement unit is Kgf / cm ² Respectively.

(3) Flexural modulus: Measured according to ASTM D 790. The unit of measurement was kgf / cm ² .

(4) Izod impact strength: measured according to ASTM D256. The unit of measurement was kgf · cm / cm.

(5) Heat distortion temperature: Measured according to ASTM D648. The measurement unit was set at ° C.

(6) Scratch resistance: Measured according to Erickson's method. The surface of the test piece prepared using an Ericsson scratch meter was scratched under the conditions shown in Table 7 and the surface state was evaluated. The L value before and after the scratch evaluation was measured using a spin sphere, and ΔL was calculated. The lower the DELTA L value, the better the scratch resistance.

Scratch resistance measurement conditions Item Condition Load (N) 10 Scraper radius 0.5 R Speed (mm / min) 1,000 Scratching interval (mm) 2 Number of scratches (W x L) 11 x 11 Scratch pattern

(7) Appearance: After the evaluation of the scratch, the surface state of the specimen was visually observed for relative comparison (O: almost no damage to the surface, ㅿ: fine surface damage was recognized, X: whitish due to obvious surface damage).

Results of physical property evaluation division Comparative Example Example One 2 3 4 5 6 7 8 One 2 3 4 5 6 Flow index
[g / 10 min]
(230 DEG C, 2.16 Kg) 21.2 21.9 18.5 21.7 23.2 22.5 48.5 45.2 20.5 23.5 32.5 314 29.5 41.2 The tensile strength
[Kgf / cm2] 215 218 219 217 216 215 203 205 218 225 226 226 227 225 Flexural modulus
[Kgf / cm2] 19,500 20,015 20,030 20,005 18,700 18,900 19,050 19,100 20,040 20,100 20,220 20,20 20,150 20,020 Izod impact strength
[Kgfcm / cm]
(-30 ° C) 2.1 2.2 2.2 2.7 3.6 3.2 2.5 2.8 4.0 4.2 4.0 4.2 3.9 3.9 Heat deformation temperature [℃] 128 129 130 129 127 129 128 129 130 129 131 132 133 133 My scratch
Delta L 4.9 4.5 3.5 3.1 3.4 2.9 4.0 2.5 1.1 0.8 0.5 0.05 0.02 0.04 Part surface appearance X X ㅿ ㅿ ㅿ ㅿ X ㅿ O O O O O O

As shown in Table 8, when Comparative Examples 1 to 4 according to the present invention were compared with Example 1, the scratch resistance and the appearance of the parts were improved by the compatibilizing agent and scratch additive.

It was also found that the scratch resistance and component appearance characteristics were improved even when the comparative examples 5 to 6 and the example 2 were compared.

In Comparative Example 7 and Comparative Example 8, also in the case of the high-fluid copper resin composition, Examples 4 to 6 showed relatively high physical properties, scratch resistance and appearance improvement. The left side of FIG. 1 is the result of Comparative Example 5, and the right side is the scratch resistance evaluation result of Example 5.

Accordingly, the polypropylene resin composition according to the present invention is characterized in that it comprises a fine crystalline polypropylene resin, a rubber component and an inorganic filler containing a block copolymer having a polydispersity index (PI) of 5 or more, fine talc having an average particle diameter of 0.5 to 0.1 탆, And the scratch additive of the newly synthesized silica masterbatch, it was confirmed that the scratch resistance as well as the surface appearance of the parts can be improved by improving the organic-inorganic interface property.

Claims (9)

(A) a highly crystalline polypropylene resin comprising at least one member selected from the group consisting of highly crystalline homopolypropylene and block copolymer polypropylene having an isotactic peptad fraction of 96% or more according to the C ¹³ -NMR method; %;
(B) 1 to 30% by weight of a rubber component;
(C) 1 to 15% by weight of an inorganic filler;
(D) 10 to 25% by weight of fine talc having an average particle size of 0.5 to 0.1 탆;
(E) 0.1 to 3.0% by weight of a compatibilizing agent; And
(F) 0.1 to 3.0 wt% of scratch additive comprising peroxide and maleic anhydride in a resin composition comprising a polypropylene resin and a silicone oil;
And a polypropylene resin composition excellent in appearance and scratch resistance.
The polypropylene resin composition according to claim 1, wherein the highly crystalline polypropylene resin (A) comprises a block copolymer having a polydispersity index (PI) of 5 or more.
The polypropylene resin composition according to claim 1, wherein the highly crystalline polypropylene resin (A) has a melt index of 1 to 110 g / 10 min and is a polypropylene homopolymer, a propylene-ethylene copolymer, a 1-butene copolymer of propylene, And propylene 4-methyl-1-pentene copolymers, and random copolymers.
The polypropylene resin composition according to claim 1, wherein the rubber component (B) is at least one member selected from the group consisting of an amorphous ethylene -olefin copolymer and a styrene-based thermoplastic elastomer.
The polypropylene resin composition according to claim 1, wherein the rubber component (B) is ethylene-octadiene or ethylene-butadiene or a mixture thereof.
The inorganic filler according to claim 1, wherein the inorganic filler (C) comprises at least one selected from the group consisting of nano-clay, glass fiber, talc, mica, calcium carbonate, wollastonite, barium sulfate, and magnesium sulfate whisker Polypropylene resin composition.
The polypropylene resin composition according to claim 1, wherein the inorganic filler (C) is talc having an average particle size of 3 to 6 탆.
The composition according to claim 1, wherein the compatibilizer (E) is a polypropylene homopolymer or a polypropylene copolymer, wherein an unsaturated carboxylic acid or an acid anhydride is grafted in an amount of 0.7 to 1.2% by weight and a melt index of 100 to 120 g / Min (230 占 폚, 2.16 kg).
2. The resin composition according to claim 1, wherein the scratch additive (F) comprises 0.03 to 0.1 phr peroxide per 100 phr of a resin composition comprising 50 to 70 wt% of a polypropylene resin and 30 to 50 wt% and 1 to 2 phr of maleic anhydride. The polypropylene resin composition according to claim 1,

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