KR101299356B1 - Polypropylene resin Composition with excellent paintability - Google Patents

Abstract

The present invention relates to a polypropylene resin composition, wherein the polypropylene resin composition comprises (A) 44 to 57% by weight of crystalline polypropylene, 9 to 21% by weight of (B) ethylenebutyl acrylate polymer, and (C) styrene-based hydrogenation. 7 to 25% by weight of the block copolymer and 10 to 23% by weight of the inorganic filler (D). The polypropylene resin composition may provide an automotive exterior plastic part having excellent paintability without applying a primer as a pretreatment agent during coating.

Description

Polypropylene resin Composition with excellent paintability}

The present invention relates to a polypropylene resin composition and a molded article using the same.

Polypropylene-based resin composition is a material with a wide range of industrial applications such as automobile interior parts, automobile exterior parts, home appliances parts, and electrical parts due to its excellent processability and mechanical strength. Plastic parts used for automotive exteriors are painted with the same color as the automobile body, in which a primer is generally used as an adhesive modifier. Recently, however, there is a need for a coating process that does not go through a primer process for the purpose of reducing volatile organic compounds (VOCs), saving energy, and improving productivity. have.

In particular, there is a need for a resin composition with improved paint adhesion in automotive exterior parts, which is not only an injection molded surface itself but also a silver streak or gas as a surface defect during injection molding. This is because traces of gas appear on the surface of molded articles, and when the parts are painted, irregularities are generated on the surface, making it difficult to obtain a beautiful appearance. In addition, when surface polishing is poor, coating film adhesion is inferior, and when the surface defect site | part of an injection molded article appears, it is difficult to use as a good product, and there exists a problem that productivity falls.

Therefore, there is a need for a resin composition capable of exhibiting excellent coating film adhesion after polishing with fine sandpaper even if defects such as silver streak or gas traces occur on the surface of the injection-molded product. do.

An object of the present invention for solving the above problems is to provide a high crystalline polypropylene resin composition excellent in coating adhesion and impact resistance.

Another object of the present invention is to provide a molded article made of the polypropylene resin composition.

According to an aspect of the present invention,

(A) 44-57 weight% of crystalline polypropylene,

(B) 9-21 weight% of ethylene butyl acrylate polymers,

(C) 7-25% by weight of styrene-based hydrogenated block copolymer and

(D) It relates to the polypropylene resin composition containing 10 to 23 weight% of inorganic fillers.

The (A) crystalline polypropylene may include at least one selected from crystalline polypropylene homopolymers and propylene-alpha olefin crystalline copolymers including C2 to C20 (excluding C3) alpha-olefin monomers. have. The melt index (230 ° C., 2.16 kg load) of the (A) crystalline polypropylene was 20 to 60 g / 10 min, and the isotactic peptide content measured by ¹³ C-NMR (nuclear magnetic resonance spectrum) was 0.80 to 0.99. Can be.

In the (B) ethylene butyl acrylate polymer, the butyl acrylate content is 20 to 40% by weight, and the melt index (190 ° C., 2.16 kg load) may be 20 to 200 g / 10 min. In addition, the styrene content in the (C) styrene hydrogenated block polymer may be 18% by weight or more.

Another aspect of the present invention relates to a molded article made of the polypropylene resin composition.

The polypropylene resin composition according to the present invention is excellent in paint adhesion and impact resistance without applying a primer as an adhesive modifier, and can be effectively applied to plastic parts for automobile exteriors.

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

The present invention provides a polypropylene resin composition.

The polypropylene resin composition may exhibit excellent paint adhesion and excellent impact resistance even without applying a primer.

The polypropylene resin composition may include (A) crystalline polypropylene, (B) ethylene butyl acrylate polymer, (C) styrene-based hydrogenated block copolymer and (D) inorganic filler.

(A) Crystalline Polypropylene

The crystalline polypropylene (A) may comprise at least one selected from a crystalline polypropylene homopolymer and a propylene-alpha olefin crystalline copolymer comprising C2 to C20 (excluding C3) alpha-olefin monomers .

Specific examples of the alpha-olefin monomers may be ethylene, 1-butene, 1-pentene, 1-hexene, 4-methylpentene, 1-heptene, 1-octene and 1-decene and preferably ethylene. The propylene-alpha olefin crystalline copolymer may be, but is not limited to, a block copolymer or a random copolymer.

The content of the propylene polymer unit in the propylene-alpha olefin crystalline copolymer is not particularly limited, but preferably includes at least 50% by weight in the copolymer.

The (A) crystalline polypropylene is not particularly limited with respect to stereoregularity, if the crystalline polypropylene can achieve the object of the present invention can be used without limitation, more specifically, ¹³ C-NMR (nuclear magnetic The isotactic peptide ratio measured by resonance spectrum) may be 0.80-0.99, preferably 0.85-0.99.

The melt flow index (MFI, 230 ° C., 2.16 kg load) of the (A) crystalline polypropylene may be 20 to 60 g / 10 minutes, preferably 20 to 50 g / 10 minutes.

The (A) crystalline polypropylene may be included 44 to 57% by weight based on the resin composition. When the content of the (A) crystalline polypropylene is included in less than 44% by weight, the coating adhesion may be lowered. When the content of the crystalline polypropylene is less than 44% by weight, the flexural modulus and the coating adhesion may be lowered.

(B) Ethylene Butyl Acrylate  polymer

In the ethylene butyl acrylate polymer (B), butyl acrylate may be contained in an amount of 20 to 40% by weight, preferably 25 to 40% by weight, based on the polymerization unit.

The (B) ethylene butyl acrylate polymer may be contained 9 to 21% by weight based on the polypropylene resin composition. When the content of the ethylene butyl acrylate polymer (B) is less than 9% by weight, the coating adhesion is poor, and when the content is more than 21% by weight, the flexural modulus may remarkably decrease.

Melt index (190 ℃, 2.16kg load) of the (B) ethylene butyl acrylate copolymer may be 5 ~ 250g / 10min, preferably 10 ~ 200g / 10min.

(C) Styrene system Hydration Block copolymer

(C) Styrene-based hydrogenated block copolymer can further improve the coating adhesion and impact resistance to the polypropylene resin composition.

The (C) styrene-based hydrogenated block copolymer is styrene-ethylene-butene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-butadiene-butylene-styrene block copolymer , Styrene-ethylene-isoprene-styrene block copolymer, acrylonitrile-butylene-styrene block copolymer, or the like, and may be one or more selected. Preferably, styrene-ethylene-butene-styrene block copolymer (SEBS) and Styrene-ethylene-propylene-styrene block copolymer (SEPS).

The (C) styrene-based hydrogenated block copolymer may be included 7 to 21% by weight with respect to the polypropylene resin composition, preferably 10 to 18% by weight. When the content of the (C) styrene-based hydrogenated block copolymer is less than 7% by weight, the coating adhesion is lowered, and if it exceeds 21% by weight, mechanical properties such as rigidity and coating adhesion may be lowered, which is not preferable.

(D) inorganic filler

The inorganic filler may be used to reinforce the rigidity of the polypropylene resin composition. The inorganic filler may be at least one selected from the group consisting of talc, barium sulfate and calcium carbonate, preferably talc.

The particle diameter of the talc may be obtained from a cumulative particle size value of 50% by weight, which is read from a particle cumulative distribution curve measured by a laser diffraction method, and the average particle diameter may be 10 μm or less, and preferably 0.5 to 8 μm. If the particle diameter of the talc is out of the above range, the flexural modulus may be lowered, which is not preferable.

In addition, the talc may contain various organic titanate coupling agents, organic silane coupling agents, unsaturated carboxylic acids, or anhydrides thereof in order to improve adhesion or dispersibility with a polymer. It may be surface treated with grafted modified polyolefins, fatty acids, fatty acid metal salts, fatty acid esters, and the like.

The inorganic filler may be included in 10 to 23% by weight, preferably 10 to 21% by weight based on the polypropylene resin composition. When the content of the inorganic filler is less than 10% by weight, the flexural modulus is significantly insufficient or the paint adhesion is lowered, and when the content of the inorganic filler exceeds 25% by weight, impact resistance may be lowered, which is not preferable.

The polypropylene resin composition according to the present invention may further include a rubber component to further improve paintability or to reinforce low temperature impact resistance. The rubber component may further include an ethylene-alpha-olefin copolymer or an ethylene-alpha-olefin elastomer rubber, and the alpha-olefin may be an alpha-olefin of C2 to C20, preferably Ethylene-1-butene copolymer.

The polypropylene resin composition according to the present invention may further contain other additional components within a range not significantly impairing the effects of the present invention. More specifically, solvents, phenolic and phosphorus antioxidants, hindered amines, benzophenones, benzotriazol-based weathering deterioration inhibitors, organoaluminum compounds, organophosphorus compounds Nucleating agents, such as dispersing agents represented by metal salts of stearic acid, quinacridone (quinacridone), titanium oxide (titanium), carbon black (carbon black) and the like, but may be included, but is not limited thereto.

The polypropylene resin composition according to the present invention may be prepared according to a method for preparing a resin composition known in the art, and for example, the components may be added to a stirring-mixing device (eg, a Helenl mixer, a super mixer or a tumbler mixer). After filling, the mixture can be stirred-mixed for 1-10 minutes and melted and kneaded using a rolling mill or an extruder at a temperature of 180-230 ° C. to pelletize.

The present invention provides a molded article made of the polypropylene resin composition.

The molded body may be an automobile interior component, an automobile exterior component, a home appliance component, an electrical component, and the like, and preferably, the automobile interior component or an automobile exterior component.

The molded body may be manufactured by any molding method such as injection molding, extrusion molding, etc. of the polypropylene resin composition, but is not limited thereto.

The present invention can be understood in more detail by the following examples and comparative examples, the following examples are only examples for illustrating the present invention, and are not intended to limit the protection scope of the present invention.

Example  1 to 7 and Comparative example  1 to 6

As shown in Table 1, the ingredients were charged to a Hensel mixer and stirred-mixed for 3 minutes. The resulting mixture was melt-extruded at 180-230 ° C. using an extruder with a diameter of 30 mm to prepare pellets.

Configuration
(weight%) Example Comparative example One 2 3 4 5 6 7 One 2 3 4 5 6 (A) 50 48 44 51 45 52 57 42 61 44 51 56 45 (B) 14 14 14 21 9 12 15 15 21 11 10 0 10 (C) 15 17 19 7 25 21 18 18 13 15 0 5 30 (C) -1 18 (C) -2 18 (D) 21 21 23 21 21 15 10 25 5 30 21 21 15

(A): Crystalline ethylene with polypropylene resin-melt flow index (melt flow rate of molten resin at 230 ° C. for 10 minutes at a load of 2.16 kg) of 45 g / 10 min, and isotactic peptide content of 0.93 to 0.99 -Propylene block copolymer

(B): an ethylene butyl acrylate polymer having a butyl acrylate content of 28% by weight and a melt index (load of 2.16 kg, 190 ° C.) of 175 g / 10 min.

(C): styrene-ethylene-butene hydrogenated block polymer (styrene content: 18%, SEBS, Tuftec H-1062)

(C-1): ethylene-butene block elastomer (Tafmer DF-605)

(C-2): ethylene-octene block elastomer (Engage 8842)

(D): Talc with an average particle diameter of 3 µm

Experimental Example

(1) Specimen manufacture

The pellets obtained in Examples and Comparative Examples were dried at 100 ° C. for 3 hours, and molded using an injection molding machine having a maximum temperature of 230 ° C. to prepare a certain test piece for testing mechanical properties. The prepared specimen was measured for mechanical properties and coating film adhesion by the following method, the results are shown in Table 2.

(2) Property measurement method

1) Melt Index (MI)

It was based on the ISO R1133 test standard at 230 ℃.

2) Izod impact strength

The injection molded molded article had a thickness of 4 mm and was based on the ISO 180A test standard.

3) Flexural modulus

Evaluation was made using ISO R178 standard specimens.

4) CROSS CUT METHOD: ASTM D3359

* Temperature: 23 ± 3 ℃, Relative humidity: 50 ± 5%, Measurement of film adhesion after leaving for 7 days

* Coating film adhesion: Coating adhesion (residual coating film count)

Configuration Example Comparative example One 2 3 4 5 6 7 One 2 3 4 5 6 MI
(g / 10 min) 35.7 33.8 32.1 48.6 29.9 32.0 30.0 29.0 31.0 28.0 55.6 48.6 48.6 curve
Modulus of elasticity
(MPa) 1230 1105 1023 1031 1452 1344 1184 1697 691 1151 1123 857 841 Izod
Shock
burglar
(23 ℃, KJ / m ² ) N.B * N.B N.B N.B N.B N.B N.B N.B N.B 24.5 N.B N.B N.B Coating
Adhesion 100 100 100 100 100 100 100 90 92 80 82 35 27

* N.B means non-break.

From the results shown in Table 1, the polypropylene resin composition according to the present invention shows excellent paint adhesion and mechanical properties. In particular, when the ethylene butyl acrylate polymer and styrene-based hydrogenated block copolymer is out of the content range according to the present invention, the coating adhesion is significantly lowered, compared with the resin composition containing the ethylene-alpha olefin rubber component used in the past. It can be confirmed that it is more excellent in terms of coating adhesion and flexural modulus.

Accordingly, the polypropylene resin composition according to the present invention can provide a molded article suitable for automotive exterior parts having excellent coating adhesion, flexural modulus, and Izod impact strength without applying a primer during coating.

Claims (8)

(A) 44-57 weight% of crystalline polypropylene,
(B) 9-21 weight% of ethylene butyl acrylate polymers,
(C) 7-25% by weight of styrene-based hydrogenated block copolymer and
(D) 10-23% by weight of inorganic filler,
The content of butyl acrylate in the (B) ethylene butyl acrylate polymer is 20 to 40% by weight polypropylene resin composition.
The method of claim 1,
The (A) crystalline polypropylene is characterized in that it comprises at least one selected from propylene polyalpha homopolymer and propylene-alpha olefin crystalline copolymer comprising C2 to C20 (excluding C3) alpha olefins Polypropylene resin composition.
The method of claim 1,
The melt flow index (230 ° C., 2.16 kg load) of the (A) crystalline polypropylene was 20 to 60 g / 10 min, and the isotactic peptide content measured by ¹³ C-NMR (nuclear magnetic resonance spectrum) was 0.80 to 0.99. Polypropylene resin composition, characterized in that.
The method of claim 1,
Melt index (190 ℃, 2.16kg load) of the (B) ethylene butyl acrylate polymer is a polypropylene resin composition, characterized in that 20 ~ 200g / 10min.
The method of claim 1,
In the (C) styrene-based hydrogenated block copolymer, the styrene content is 18% by weight or more.
The method of claim 1,
The (C) styrene-based hydrogenated block copolymer is styrene-ethylene-butene-styrene block copolymer (SEBS), styrene-ethylene-propylene-styrene block copolymer (SEPS), styrene-butadiene-butylene-styrene block copolymer And at least one member selected from the group consisting of styrene-ethylene-isoprene-styrene block copolymers and acrylonitrile-butylene-styrene block copolymers.
A molded article produced from the polypropylene resin composition according to any one of claims 1 to 6.
The method of claim 7, wherein
The molded article is a molded article, characterized in that the vehicle exterior parts.