KR20210066506A - Polypropylene resin composition with increased impact strength - Google Patents

Abstract

The present invention relates to a polyolefin resin composition having improved impact strength. The polypropylene resin composition includes: 5-30 wt% of a polyolefin elastomer which is a copolymer of ethylene or propylene with a C3-C10 alpha-olefin, has a content of alpha-olefin equal to or more than 30 wt% and less than 50 wt%, and shows a melt index of 3-10 g/10 min (2.16kg, 190℃); and the balance amount of crystalline polypropylene having a melt index of 30-100 g/10 min (2.16kg, 230℃).

Description

Polypropylene resin composition for injection with improved impact strength {POLYPROPYLENE RESIN COMPOSITION WITH INCREASED IMPACT STRENGTH}

The present invention relates to a polypropylene resin composition for injection having improved impact strength.

In general, polypropylene resin among polyolefins has great advantages such as moldability, chemical resistance, low specific gravity and low cost, and is widely used in various industrial materials.

The polypropylene is also applied to automobile materials, and when used in automobile materials, it requires physical properties such as high impact strength, scratch resistance, and high rigidity at room temperature and low temperature. In particular, room temperature and low temperature impact strength is required. In order to satisfy these characteristics, a high content of rubber component is added to polypropylene resin in the prior art, and a certain amount of filler has been added to satisfy high rigidity. In this case, polyolefin elastomer (POE) is one of the most used rubber components.

Typically, the polyolefin elastomer is prepared by copolymerizing a comonomer such as butene and octene with ethylene, which is a main component, using a metallocene catalyst, and is used as a material for reinforcing impact strength. In this case, a polyolefin elastomer having a different comonomer content and structure according to the type of catalyst used for polymerization is prepared.

Korean Patent Publication No. 2009-0003593

An object of the present invention is to provide a polypropylene resin composition for injection that can be used as a material for automobile parts requiring high impact strength by using a polyolefin elastomer. In particular, the present invention is to provide a polypropylene resin composition with improved impact strength that can be used as a part such as a bumper.

The present invention is to provide a polypropylene resin composition with improved impact strength, and in one aspect, a copolymer of ethylene or propylene and C ₃ -C ₁₀ alpha-olefin, wherein the alpha-olefin content is 30% by weight or more. Less than 50% by weight, 5 to 30% by weight of a polyolefin elastomer having a melt index of 3 to 10g/10min (2.16kg, 190°C); and a melt index of 30 to 100 g/10 min (2.16 kg, 230° C.) of crystalline polypropylene as the balance.

In another aspect, the present invention is to provide a polypropylene resin molded article prepared from the polypropylene resin composition.

The polypropylene resin composition of the present invention has high impact strength and thus has properties suitable for use as a material for automobile parts, particularly for injection molding such as bumpers.

1 is an image taken by SEM of the surface of the injection-molded specimen using the compositions of Example 1 and Comparative Example 2, after melting the POE portion by etching the cut surface with xylene.

Hereinafter, preferred embodiments of the present invention will be described. However, the embodiment of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

The polypropylene resin composition of the present invention includes a crystalline polypropylene, a polyolefin elastomer and an inorganic filler.

As used herein, the term “alkyl” refers to a monovalent straight-chain or branched saturated hydrocarbon radical composed only of carbon and hydrogen atoms, and examples of such alkyl radicals include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t- butyl, pentyl, hexyl, octyl, dodecyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, and the like.

In addition, as used herein, the term "alkenyl" refers to a straight-chain or branched hydrocarbon radical containing one or more carbon-carbon double bonds, and includes ethenyl, propenyl, butenyl, pentenyl, and the like, However, the present invention is not limited thereto.

In addition, the term "alkynyl" as used in the present invention refers to a straight-chain or branched hydrocarbon radical containing at least one carbon-carbon triple bond, and methynyl, ethynyl, propynyl, butynyl, pentynyl, hexy nyl, heptynyl, octynyl, and the like.

In addition, the term "aryl" described in the present invention is an organic radical derived from an aromatic hydrocarbon by removal of one hydrogen, and includes a single or fused ring system. Specific examples include, but are not limited to, phenyl, naphthyl, biphenyl, anthryl, fluorenyl, phenanthryl, triphenylenyl, pyrenyl, peryleneyl, chrysenyl, naphthacenyl, fluoranthenyl, and the like.

In addition, the term "alkylaryl" as used in the present invention refers to an organic group in which one or more hydrogens of the aryl group are substituted by an alkyl group, and methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, iso butylphenyl, t-butylphenyl, and the like.

In addition, the term "arylalkyl" described in the present invention refers to an organic group in which one or more hydrogens of the alkyl group are substituted by an aryl group, and includes, but is not limited to, phenylpropyl, phenylhexyl, and the like.

In addition, the term "amido" described in the present invention refers to an amino group (-NH ₂ ) bonded to a carbonyl group (C=O), and “alkylamido” is an alkyl group in which at least one hydrogen in _{-NH 2 of the amido group is an alkyl group.} means an organic group substituted with, "arylamido" means an organic group _{in which at least one hydrogen is substituted with an aryl group in -NH 2} of the amido group, an alkyl group in the alkylamido group, and an aryl group in the arylamido group It may be the same as the examples of the above-described alkyl group and aryl group, but is not limited thereto.

In addition, the term "alkylidene" as used in the present invention refers to a divalent aliphatic hydrocarbon group in which two hydrogen atoms have been removed from the same carbon atom of the alkyl group, and ethylidene, propylidene, isopropylidene, butylidene, pentylidene and the like.

In addition, the term "acetal" described in the present invention refers to an organic group formed by the bond between alcohol and aldehyde, that is, a substituent having two ether (-OR) bonds on one carbon, methoxymethoxy, 1-meth ethoxy, 1-methoxypropyloxy, 1-methoxybutyloxy, 1-ethoxyethoxy, 1-ethoxypropyloxy, 1-ethoxybutyloxy, 1-(n-butoxy)ethoxy, 1-(iso-butoxy)ethoxy, 1-(sec-butoxy)ethoxy, 1-(tert-butoxy)ethoxy, 1-(cyclohexyloxy)ethoxy, 1-methoxy -1-methylmethoxy, 1-methoxy-1-methylethoxy, and the like.

In addition, the term "ether" described in the present invention is an organic group having at least one ether bond (-O-), 2-methoxyethyl, 2-ethoxyethyl, 2-butoxyethyl, 2-phenoxyethyl , 2- (2-methoxyethoxy) ethyl, 3-methoxypropyl, 3-butoxypropyl, 3-phenoxypropyl, 2-methoxy-1-methylethyl, 2-methoxy-2-methylethyl , 2-methoxyethyl, 2-ethoxyethyl, 2-butoxyethyl, 2-phenoxyethyl, and the like.

In addition, the term "silyl" described in the present invention refers to a -SiH ₃ radical derived from silane, and at least one of the hydrogen atoms in the silyl group may be substituted with various organic groups such as alkyl and halogen, and specifically as trimethylsilyl, triethylsilyl, t-butyldimethylsilyl, vinyldimethylsilyl, propyldimethylsilyl, triphenylsilyl, diphenylsilyl, phenylsilyl, trimethoxysilyl, methyldimeroxysilyl, ethyldiethoxysilyl, triethoxysilyl, vinyldimethoxysilyl, triphenoxysilyl, and the like.

In addition, as used herein, the term “alkoxy” refers to an —O-alkyl radical, where “alkyl” is as defined above. Examples of such alkoxy radicals include, but are not limited to, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, t-butoxy, and the like.

In addition, the term "halogen" described in the present invention means a fluorine, chlorine, bromine or iodine atom.

In addition, the term "C _n " described in the present invention means that the number of carbon atoms is n.

The polypropylene resin composition of the present invention contains crystalline polypropylene as a main component. The crystalline polypropylene may be a propylene homopolymer, or a propylene copolymer which is a copolymer of propylene and at least one comonomer selected from _{ethylene or C 4} -C _{10 alpha-olefin.} The C ₄ -C ₁₀ alpha-olefin is not particularly limited, and examples thereof include butene, pentene, hexene, and octene. As the crystalline polypropylene, any one of a propylene homopolymer and a propylene copolymer may be used alone, and these may be mixed and used.

When a propylene copolymer is used as the crystalline polypropylene in the present invention, ethylene or C ₄ -C ₁₀ alpha-olefin as a comonomer may be included in the propylene copolymer in an amount of 1 to 12% by weight. When the content of the comonomer is less than 1% by weight, sufficient impact strength cannot be secured, and when it exceeds 12% by weight, mechanical properties may decrease. Preferably, the content of the comonomer may be 3 to 10% by weight.

In the polypropylene resin composition of the present invention, the crystalline polypropylene may have a melt index of 30 to 100 g/10 min (2.16 kg, 230° C.). If the melt index is less than 30g/10min, a problem of unmolding may occur during injection molding, and if it exceeds 100g/10min, mechanical properties of the final product may be lowered. Preferably, one having a melt index in the range of 50 to 80 g/10 min of the crystalline polypropylene may be used.

The polyolefin elastomer included in the polypropylene resin composition of the present invention may be a polyethylene elastomer, which is a copolymer _{of ethylene and C 3} -C _{8 alpha-olefin.} The alpha-olefin may be, for example, at least one selected from the group consisting of propylene, butene, hexene and octene, more preferably butene or octene.

The alpha-olefin may be included in an amount of 30 wt% or more and less than 50 wt% in the polyethylene elastomer. If the content of alpha-olefin is less than 30% by weight, the impact strength of the injection-molded article cannot be sufficiently improved, and the higher the content of alpha-olefin, the impact strength of the injection-molded article can be improved. % or more, it does not play a role as a comonomer, and the desired elastomer may not be produced. Preferably, the alpha-olefin may be included in an amount of 35 to 45% by weight.

The polyolefin elastomer preferably has a melt index of 3 to 10 g/10 min (2.16 kg, 190° C.). If the melt index of the polyolefin elastomer is less than 3 g/10 min, injection moldability deteriorates and may be unmolded, and if it exceeds 10 g/10 min, the flowability becomes excessively high and the dispersibility with polypropylene is poor, thereby reducing the impact strength. can be lowered

The polyolefin elastomer may be polymerized in the presence of a metallocene catalyst. The metallocene catalyst may preferably be a transition metal compound having a thiophene-condensed ring cyclopentadienyl ligand derived from a tetrahydroquinoline derivative.

More preferably, the transition metal compound is derived from a tetrahydroquinoline derivative, an amido ligand and ortho-phenylene form a condensed ring, and a pentacyclic pi-ligand bonded to ortho-phenylene is thiophene. It may have a ligand fused by a hetero ring.

In this case, the transition metal of the transition metal compound may be a Group 4 metal.

The transition metal compound may have a structure as shown in Formula 1 below.

In Formula 1, M is selected from the group consisting of a Group 4 transition metal element on the periodic table, and may preferably be titanium or zirconium.

In Formula 1, Q ¹ and Q ² may be the same as or different from each other, and each independently halogen, (C ₁ -C ₂₀ )alkyl group, (C ₂ -C ₂₀ )alkenyl group, (C ₂ -C _{20 )} ) alkynyl group, (C ₆ -C ₂₀ )aryl group, (C ₁ -C ₂₀ )alkyl (C ₆ -C ₂₀ )aryl group, (C ₆ -C ₂₀ )aryl (C ₁ -C ₂₀ )alkyl group, ( C ₁ -C ₂₀ )alkylamido group, (C ₆ -C ₂₀ )arylamido group or (C ₁ -C ₂₀ )alkylidene group, preferably methyl or chlorine.

In Formula 1, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ may be the same as or different from each other, and each independently hydrogen; _{A (C 1} -C ₂₀ )alkyl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{A (C 2} -C ₂₀ )alkenyl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{a (C 1} -C ₂₀ )alkyl(C ₆ -C ₂₀ )aryl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{a (C 6} -C ₂₀ )aryl(C ₁ -C ₂₀ )alkyl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{a (C 1} -C ₂₀ )silyl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; The R ¹ and R ² and R ³ and R ⁴ may be independently connected to each other to form a ring, and ^{two or more of R 5} to R ¹⁰ may be connected to each other to form a ring.

In Formula 1, R ¹¹ , R ¹² and R ¹³ may be the same as or different from each other, and each independently hydrogen; _{(C 1} -C ₂₀ )alkyl unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{A (C 2} -C ₂₀ )alkenyl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{a (C 1} -C ₂₀ )alkyl(C ₆ -C ₂₀ )aryl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{a (C 6} -C ₂₀ )aryl(C ₁ -C ₂₀ )alkyl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{A (C 1} -C ₂₀ )silyl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; (C ₁ -C ₂₀ )alkoxy; or (C ₆ -C ₂₀ )aryloxy; The R ¹¹ and R ¹² or R ¹² and R ¹³ may be connected to each other to form a ring.

When the transition metal compound represented by Formula 1 as described above is used as a catalyst, the reactivity of alpha-olefin is excellent, so that the comonomer can be included in a high content in the polyolefin elastomer, and at the same time, a polyolefin elastomer with a large molecular weight can be prepared. have. Furthermore, the polyolefin elastomer prepared using the catalyst has excellent compatibility with the polypropylene resin, so dispersibility can be further improved, and the domain size of the polyolefin elastomer can be formed small in the polypropylene resin, resulting in a polypropylene injection molded article impact strength can be further improved.

The polyolefin elastomer may be dispersed in the polypropylene resin composition as small and uniformly sized domains. Specifically, the polyolefin elastomer in the polypropylene resin composition may have an average domain size of 1.0 to 2.0 μm and a domain size standard deviation of 0.5 to 1.5 μm. Such domain size and standard deviation can be confirmed by measuring the size of pores existing on the cross section after removing the polyethylene elastomer domain by etching the cut surface of the molded article (1 cm × 1 cm size) with xylene.

In the polypropylene resin composition of the present invention, the content of the polyolefin elastomer may be 5 to 30% by weight. If the content of the polyolefin elastomer is less than 5% by weight, the impact strength of the resin composition may be insufficient, and if it exceeds 30% by weight, the melt index may decrease, and a phase transition may occur between materials. It causes an increase, which is not preferable. Preferably, the polyolefin elastomer may be included in an amount of 10 to 20 wt%.

The polypropylene resin composition of the present invention may include an inorganic filler. The inorganic filler is used to reinforce the rigidity of the polypropylene resin composition, which is reduced by including the polyolefin resin in the polypropylene. Examples of the inorganic filler that can be used in the present invention include, but are not limited to, talc, calcium carbonate, magnesium oxide, calcium stearate, mica, clay and carbon black, and any one of these may be used alone. Of course, two or more types may be mixed and used.

The inorganic filler may have an average particle diameter of 1 to 30 μm. If the average particle diameter of the inorganic filler is less than 1 μm, the interfacial energy is high and aggregation between particles may occur, which may not be uniformly dispersed in the polypropylene resin composition. The reinforcement effect may be reduced. Preferably, the inorganic filler may have an average particle diameter of 5 to 10 μm.

The inorganic filler may be included in the resin composition in an amount of 5 to 30% by weight. When the content of the inorganic filler is less than 5% by weight, the effect of reinforcing the rigidity is lowered, and when it exceeds 30% by weight, uniform dispersibility cannot be obtained in the composition, which may cause deterioration of physical properties, and handling during extrusion And there is a problem that the operation is not easy. Preferably, the inorganic filler may be included in an amount of 10 to 20% by weight.

As described above, the polypropylene resin composition provided in the present invention includes the polyolefin elastomer prepared by using the transition metal catalyst as described above in the polypropylene resin, thereby further improving the impact strength when manufacturing an injection molded article. . More specifically, the polypropylene resin composition provided in the present invention has better impact strength in injection-molded articles when the content of the polyolefin elastomer in each composition is equal to that of the conventional polypropylene resin composition.

The polypropylene resin composition of the present invention can be suitably used as a material requiring high impact strength and rigidity, such as, for example, an automobile bumper.

Example

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are one embodiment of the present invention, and are not intended to limit the present invention thereby.

Example One

Ethylene-butene copolymer prepared by using 60 wt% of block polypropylene having an ethylene content of 8 wt% (melting index 60g/10min (2.16kg, 230°C)) and a catalyst having the following structure (Me represents a methyl group) 20% by weight of coal (POE-1, butene 40% by weight, density 0.865g/cm3, melt index 5g/10min (2.16kg, 190℃)) and 20% by weight of talc (average particle size 5.5㎛) were mixed with a Hensel mixer ) and mixed for 5 minutes.

The mixed material was melt-extruded at 170 to 230° C. using a twin-screw extruder having a diameter of 40 mm and an L/D of 40 to prepare pellets.

comparative example One

Ethylene-butene copolymer (POE) prepared using 60% by weight of block polypropylene having an ethylene content of 8% by weight (melting index 60g/10min (2.16kg, 230°C)) and trade name Lucene LC565 (manufactured by LG Chem) as a catalyst Example 1 except that 20% by weight of -2, butene 32% by weight, density 0.865g/cm 3 , melt index 5g/10min (2.16kg, 190℃)) and 20% by weight of talc (average particle diameter 5.5㎛) were used Pellets were prepared in the same way as

comparative example 2

Ethylene-butene copolymer (POE) prepared by using 60% by weight of block polypropylene having an ethylene content of 8% by weight (melting index 60g/10min (2.16kg, 230℃)) and Tafmer DF-640 (manufactured by Mitsui) as a catalyst Example 1 except that 20% by weight of -3, butene 33% by weight, density 0.864g/cm 3 , melt index 5g/10min (2.16kg, 190℃)) and 20% by weight of talc (average particle size of 5.5㎛) were used Pellets were prepared in the same way as

comparative example 3

Ethylene-butene copolymer (POE-4) prepared by using 60% by weight of block polypropylene having an ethylene content of 8% by weight (melting index 60g/10min (2.16kg, 230℃)) and Engage 7447 (manufactured by Dow) as a catalyst , butene 33% by weight, density 0.865g/cm 3 , melt index 5g/10min (2.16kg, 190℃)) 20% by weight, and talc (average particle diameter 5.5㎛) 20% by weight, except that 20% by weight was used as in Example 1 Pellets were prepared by the method.

physical property measurement

Specimens were prepared by injection molding using the pellets prepared in Examples and Comparative Examples, and each physical property was measured by the following method. The measurement results are shown in Table 1.

Tensile strength : A specimen was prepared according to ASTM D638 standard, and tensile strength was measured.

Elongation : A specimen was prepared according to the ASTM D638 standard, and the elongation was measured.

Flexural strength : Specimens were manufactured according to ASTM D790 standard, and flexural strength was measured.

Flexural modulus : A specimen was prepared according to ASTM D790 standard, and the flexural modulus was measured.

Shrinkage : The distance between the marked lines marked on the injection specimen compared to the marked lines marked at 140.25mm intervals on the ASTM D638 type 1 specimen mold was measured.

IZOD impact strength : Specimens were prepared according to ASTM D256 standard, and impact strength was measured.

Dupont impact strength : Specimens were manufactured according to ASTM D256 standard, and impact strength was measured.

SEM measurement : A specimen having a size of 1 cm × 1 cm was prepared by cutting the specimen used for IZOD impact strength measurement. After the cut surface was etched with xylene to melt the POE part in the specimen, the voids were observed. By measuring the size of the pores, the average domain size and the standard deviation of the domain size were calculated. A cross section of the specimen after etching was photographed by SEM, and is shown in FIG. 1 .

Example comparative example One One 2 3 ingredient Block PP (wt%) 60 60 60 60 POE Kinds POE-1 POE-2 POE-3 POE-4 content (wt%) 20 20 20 20 Inorganic filler (wt%) 20 20 20 20 Properties The tensile strength 161 163 160 162 Elongation (%) 61 56 40 58 Flexural strength (kgf/㎠) 262 264 221 260 Flexural modulus (kgf/㎠) 15000 15000 14200 14800 Shrinkage (mm/1000mm) 0.8 0.8 0.9 0.8 IZOD 23℃ (kgf.cm/cm) 39.4 39.2 37.3 38.0 IZOD -10℃ (kgf.cm/cm) 8.2 7.9 8.0 7.6 Dupont -10℃ (kgcm) 200 140 160 150 Domain average size (μm) 1.37 - 2.18 - domain size standard deviation 0.71 - 2.34 -

As can be seen from Table 1, the resin composition of Example 1 including the polyolefin elastomer according to the present invention has higher IZOD impact strength and Dupont impact strength compared to the resin compositions of Comparative Examples 1 to 3 It can be confirmed. .

In particular, as a result of confirming the difference between the domain average size and the domain size standard deviation through the SEM images of Example 1 and Comparative Example 2, the domain average size using the resin composition of Example 1 was small and the size deviation was small, so that the domain size was uniform. It can be confirmed that there is From this, it is judged that the resin composition of Example 1 has a small domain size and a uniform size distribution, so that the interfacial energy between the domain and the matrix is increased to increase the kneading property, thereby improving the impact strength.

Claims (7)

A copolymer of ethylene or propylene and C ₃ -C ₁₀ α-olefin, wherein the α-olefin content is 30% by weight or more and less than 50% by weight, and the melt index is 3 to 10g/10min (2.16kg, 190℃) 5 to 30% by weight of polyolefin elastomer; and
A polypropylene resin composition for injection, comprising the balance of crystalline polypropylene having a melt index of 30 to 100 g/10 min (2.16 kg, 230° C.). The polypropylene for injection according to claim 1, wherein the crystalline polypropylene is a propylene copolymer comprising at least one selected from _{ethylene and C 4} -C _{10 α-olefin as a propylene homopolymer or comonomer, or a mixture thereof.} Propylene resin composition. The polypropylene resin composition according to claim 2, wherein the propylene copolymer contains a comonomer in an amount of 1 to 12% by weight. The polypropylene resin composition for injection according to claim 1, further comprising 5 to 30 wt% of an inorganic filler. The polypropylene resin composition for injection according to claim 1, wherein the polyolefin elastomer in the composition has an average domain size of 1.0 to 2.0 μm. The polypropylene resin composition according to claim 1, wherein the polyolefin elastomer is polymerized in the presence of a catalyst comprising a transition metal compound represented by the following formula (1):
[Formula 1]

(In Formula 1,
M is a group 4 transition metal element on the periodic table,
Q ¹ and Q ² may be the same as or different from each other, and each independently a halogen, (C ₁ -C ₂₀ )alkyl group, (C ₂ -C ₂₀ )alkenyl group, (C ₂ -C ₂₀ )alkynyl group, ( C ₆ -C ₂₀ )aryl group, (C ₁ -C ₂₀ )alkyl (C ₆ -C ₂₀ )aryl group, (C ₆ -C ₂₀ )aryl(C ₁ -C ₂₀ )alkyl group, (C ₁ -C _{20 )} ) alkylamido group, (C ₆ -C ₂₀ ) arylamido group or (C ₁ -C ₂₀ )alkylidene group,
R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ may be the same as or different from each other, and each independently hydrogen; _{A (C 1} -C ₂₀ )alkyl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{A (C 2} -C ₂₀ )alkenyl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{a (C 1} -C ₂₀ )alkyl(C ₆ -C ₂₀ )aryl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{a (C 6} -C ₂₀ )aryl(C ₁ -C ₂₀ )alkyl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{a (C 1} -C ₂₀ )silyl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; The R ¹ and R ² or R ³ and R ⁴ may be connected to each other to form a ring, and ^{two or more of R 5} to R ¹⁰ may be connected to each other to form a ring,
R ¹¹ , R ¹² and R ¹³ may be the same as or different from each other, and each independently hydrogen; _{(C 1} -C ₂₀ )alkyl unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{A (C 2} -C ₂₀ )alkenyl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{a (C 1} -C ₂₀ )alkyl(C ₆ -C ₂₀ )aryl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{a (C 6} -C ₂₀ )aryl(C ₁ -C ₂₀ )alkyl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; _{A (C 1} -C ₂₀ )silyl group unsubstituted or substituted with an acetal group, a ketal group, or an ether group; (C ₁ -C ₂₀ )alkoxy; or (C ₆ -C ₂₀ )aryloxy; R ¹¹ and R ¹² or R ¹² and R ¹³ may be connected to each other to form a ring). A molded article made of the polypropylene resin composition of any one of claims 1 to 4.

Images