Polypropylene resin composition and article produced therefrom

Abstract

A polypropylene resin composition of the present invention comprises: approximately 100 parts by weight of a block polypropylene resin; approximately 15-30 parts by weight of a melted blend of approximately 65-99 wt% of an ultra-low density polyethylene having a density of approximately 0.88-0.91 g / cm3, measured according to ISO 1183-1, and approximately 1-35 wt% of a styrene-based thermoplastic elastomer; approximately 10-120 parts by weight of a reactor-made thermoplastic olefin (RTPO); and approximately 20-45 parts by weight of talc. The polypropylene resin composition has excellent impact resistance, rigidity, thermal resistance, dimensional stability, a balance of these properties, and the like.

Description

Polypropylene resin composition and molded article manufactured therefrom

[0001] The present invention relates to a polypropylene resin composition and a molded article manufactured therefrom. More specifically, the present invention relates to a polypropylene resin composition having excellent impact resistance, rigidity, heat resistance, dimensional stability, and a balance of physical properties thereof, and a molded article manufactured therefrom.

[0002]

[0003] Polyolefin resins have excellent chemical resistance, weather resistance, and processability, making them easy to manufacture into injection-molded products, films, and blow-molded products. They are widely used in fields such as electrical components, automobiles, and building materials. However, conventional propylene-based resins have low impact resistance, so olefin-based elastomers based on copolymers of ethylene and α-olefin are applied to reinforce impact resistance.

[0004] However, the rubber (olefin elastomer) added during this process may degrade the moldability and stiffness of the propylene-based resin, and if inorganic fillers are added to improve stiffness, impact resistance may be reduced. Furthermore, depending on the characteristics of the crystalline polymer, propylene-based resin exhibits high shrinkage characteristics, and there is a risk of post-shrinkage occurring even when olefin elastomers and inorganic fillers are added.

[0005] Therefore, there is a need to develop polypropylene resin compositions with excellent impact resistance, rigidity, heat resistance, dimensional stability, and a balance of these physical properties.

[0006] The background technology of the present invention is disclosed in Korean registered patent No. 10-0842162, etc.

[0007]

[0008] The objective of the present invention is to provide a polypropylene resin composition having excellent impact resistance, rigidity, heat resistance, dimensional stability, and a balance of these physical properties.

[0009] Another objective of the present invention is to provide a molded article formed from the polypropylene resin composition.

[0010] The above and other objectives of the present invention can all be achieved by the present invention described below.

[0011]

[0012] 1. One aspect of the present invention relates to a polypropylene resin composition. The polypropylene resin composition comprises about 100 parts by weight of block polypropylene resin; having a density of about 0.88 to about 0.91 g / cm³ as measured according to ISO 1183-1. 3 It comprises about 15 to about 30 parts by weight of a melt blend of about 65 to about 99 parts by weight of ultra-low density polyethylene and about 1 to about 35 parts by weight of a styrene-based thermoplastic elastomer; about 10 to about 120 parts by weight of RTPO (Reactor made ThermoPlastic Olefin); and about 20 to about 45 parts by weight of talc.

[0013] 2. In the above embodiment 1, the block polypropylene resin may have a melt-flow index of about 10 to about 150 g / 10 min, measured at 230°C and a 2.16 kg load according to ASTM D1238.

[0014] 3. In the above 1 or 2 embodiments, the ultra-low density polyethylene may have a melt flow index of about 1 to about 20 g / 10 min measured at 190°C and a 2.16 kg load according to ASTM D1238.

[0015] 4. In the above 1 to 3 embodiments, the styrene-based thermoplastic elastomer may include one or more of styrene-ethylene-butylene-styrene block copolymer, styrene-ethylene-propylene-styrene block copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, and styrene-butadiene-butylene-styrene block copolymer.

[0016] 5. In the above 1 to 4 embodiments, the styrene-based thermoplastic elastomer may have a styrene-based monomer content of about 5 to about 50 weight%.

[0017] 6. In the above 1 to 5 embodiments, the styrene-based thermoplastic elastomer may have a weight-average molecular weight of about 100,000 to about 450,000 g / mol.

[0018] 7. In the above 1 to 6 embodiments, the RTPO may be a propylene-based block copolymer having an ethylene-propylene rubber content of about 15 weight% or more and a melt flow index of about 3 to about 60 g / 10 min measured at 230°C and 2.16 kg load conditions according to ASTM D1238.

[0019] 8. In the above 1 to 7 embodiments, the talc may have an average particle size of about 0.5 to about 3.8 μm as measured by a particle size measuring device.

[0020] 9. In the above 1 to 8 embodiments, the polypropylene resin composition may be in a form where the block polypropylene resin, the RTPO, and the talc are in the continuous phase, the ultra-low density polyethylene is in the dispersed phase, and the styrene-based thermoplastic elastomer is present at the interface between the continuous phase and the dispersed phase.

[0021] 10. In the above embodiments 1 to 9, the polypropylene resin composition has a notched Izod impact strength of about 20 to about 50 kJ / m² as measured according to ISO 180. 2 It could be.

[0022] 11. In the above 1 to 10 embodiments, the polypropylene resin composition may have a tensile strength of about 10 to about 30 MPa of a 4 mm thick specimen measured under 50 mm / min conditions according to ISO 527-1A.

[0023] 12. In the above 1 to 11 embodiments, the polypropylene resin composition may have a flexural strength of about 15 to about 35 MPa of a 4 mm thick specimen measured under 2 mm / min conditions according to ISO 178 standards, and a flexural modulus of about 1,000 to about 2,500 MPa of a 4 mm thick specimen measured under 2 mm / min conditions according to ISO 178 standards.

[0024] 13. In the above 1 to 12 embodiments, the polypropylene resin composition may have a heat distortion temperature (HDT) of an 80 mm × 10 mm × 4 mm specimen measured under conditions of 0.45 MPa and a heating rate of 120℃ / hr according to ISO 75, which is about 90 to about 110℃.

[0025] 14. In the above 1 to 13 embodiments, the polypropylene resin composition may have a linear expansion coefficient of about 65 to about 85 μm / m·℃ for a specimen of size 100 mm × 100 mm × 4 mm measured by increasing the temperature from -30℃ to 100℃ at a rate of 5℃ / min according to ASTM E831.

[0026] 15. Another aspect of the present invention relates to a molded article. The molded article is characterized by being formed from a polypropylene resin composition according to any one of 1 to 14.

[0027]

[0028] The present invention has the effect of providing a polypropylene resin composition having excellent impact resistance, rigidity, heat resistance, dimensional stability, and a balance of physical properties thereof, and a molded article formed therefrom.

[0029]

[0030] The present invention will be described in detail below.

[0031] The polypropylene resin composition according to the present invention comprises (A) block polypropylene resin; (B) a melt blend of ultra-low density polyethylene and styrene-based thermoplastic elastomer; (C) RTPO and (D) talc.

[0032] In this specification, "a to b" indicating a numerical range is defined as "≥a and ≤b".

[0033]

[0034] (A) Block polypropylene resin

[0035] A block polypropylene resin according to one embodiment of the present invention can be applied together with a melt blend of ultra-low density polyethylene and a styrene-based thermoplastic elastomer, RTPO, and talc, etc., to improve the impact resistance, stiffness, heat resistance, dimensional stability, and balance of physical properties of a polypropylene resin composition, and a block polypropylene resin applied to a conventional thermoplastic resin composition can be used.

[0036] In a specific example, the block polypropylene resin may be a block polypropylene resin composed of a homopolypropylene block, an ethylene-propylene copolymer block and / or a homopolyethylene block.

[0037] In a specific example, the block polypropylene resin may have a weight-average molecular weight of about 100,000 to about 250,000 g / mol as measured by gel permeation chromatography (GPC), for example, about 120,000 to about 200,000 g / mol. Within this range, the mechanical properties, moldability, etc., of the polypropylene resin composition may be excellent.

[0038] In a specific example, the block polypropylene resin may have a Melt-flow Index (MI) of about 10 to about 150 g / 10 min, for example, about 25 to about 120 g / 10 min, measured according to ASTM D1238 at 230°C and a 2.16 kg load. Within this range, the mechanical properties and moldability of the polypropylene resin composition may be excellent.

[0039]

[0040] (B) Melt blend of ultra-low density polyethylene and styrene-based thermoplastic elastomer

[0041] A melt blend of ultra-low density polyethylene and styrene-based thermoplastic elastomer according to one embodiment of the present invention is applied together with block polypropylene resin, RTPO, and talc, etc., to improve the impact resistance, stiffness, heat resistance, dimensional stability, and balance of physical properties of the polypropylene resin composition.

[0042] In a specific example, the very low density polyethylene (VLDPE) has a density of about 0.88 to about 0.91 g / cm³ as measured according to ISO 1183-1. 3 , for example, about 0.885 to about 0.91 g / cm³ 3 It may be. The density of the above ultra-low density polyethylene is approximately 0.88 g / cm³ 3 If it is less than, there is a risk that the dimensional stability, stiffness, etc. of the polypropylene resin composition may decrease, and approximately 0.91 g / cm³ 3 If it exceeds [amount], there is a risk that the impact resistance, dimensional stability, etc. of the polypropylene resin composition may be reduced.

[0043] In a specific example, the ultra-low density polyethylene may have a melt flow index of about 1 to about 20 g / 10 min measured at 190°C and a 2.16 kg load condition according to ASTM D1238. Within this range, the moldability of the polypropylene resin composition may be excellent.

[0044] In a specific example, the ultra-low density polyethylene may have a weight-average molecular weight of about 100,000 to about 550,000 g / mol as measured by gel permeation chromatography (GPC), for example, about 150,000 to about 500,000 g / mol. Within this range, the mechanical properties, elasticity, etc. of the polypropylene resin composition may be excellent.

[0045] In a specific example, the ultra-low density polyethylene may be included in an amount of about 65 to about 99 weight%, for example, about 70 to about 95 weight%, of 100 weight% of the total melt blend. If the content of the ultra-low density polyethylene is less than about 65 weight% of 100 weight% of the total melt blend, there is a risk that the rigidity, heat resistance, etc. of the polypropylene resin composition will decrease, and if it exceeds about 99 weight%, there is a risk that the impact resistance, moldability, etc. of the polypropylene resin composition will decrease.

[0046] In a specific example, the styrene-based thermoplastic elastomer may be a styrene-ethylene-butylene-styrene block copolymer, a styrene-ethylene-propylene-styrene block copolymer, a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a styrene-butadiene-butylene-styrene block copolymer, or a combination thereof.

[0047] In a specific example, the styrene-based thermoplastic elastomer may have a styrene-based monomer content of about 5 to about 50 weight%, for example, about 5 to about 45 weight%. Within this range, the mechanical properties, elasticity, etc. of the polypropylene resin composition may be excellent.

[0048] In a specific example, the styrene-based thermoplastic elastomer may have a weight-average molecular weight of about 100,000 to about 450,000 g / mol as measured by gel permeation chromatography (GPC), for example, about 150,000 to about 400,000 g / mol. Within this range, the mechanical properties, moldability, etc. of the polypropylene resin composition may be excellent.

[0049] In a specific example, the styrene-based thermoplastic elastomer may be included in an amount of about 1 to about 35 weight%, for example, about 5 to about 30 weight%, of 100 weight% of the total melt blend. If the content of the styrene-based thermoplastic elastomer is less than about 1 weight% of the total melt blend, there is a risk that the impact resistance, moldability, etc. of the polypropylene resin composition will be reduced, and if it exceeds about 35 weight%, there is a risk that the stiffness, heat resistance, etc. of the polypropylene resin composition will be reduced.

[0050] In a specific example, the melt blend may be manufactured according to a manufacturing method comprising the steps of: mixing the ultra-low density polyethylene and the styrene-based thermoplastic elastomer to prepare a mixture; and melt-extruding the mixture.

[0051] In a specific example, the melt extrusion can be performed using a conventional twin-screw extruder at a temperature of about 150 to about 250°C, for example, about 170 to about 230°C. Within this range, the mechanical properties, fluidity, dimensional stability, and balance of the properties of the polypropylene resin composition may be excellent.

[0052] In a specific embodiment, the molten blend may be manufactured in the form of pellets, and the manufactured pellets may be applied to various thermoplastic resin compositions and molded articles (products), or the molten blend alone may be manufactured into a molded article (product) through various molding methods such as injection molding, extrusion molding, vacuum molding, and casting molding. Such molding methods are well known to those skilled in the art to which the present invention pertains.

[0053] In a specific example, the molten blend may be in the form of a mixture of ultra-low density polyethylene as the continuous phase and a styrene-based thermoplastic elastomer as the dispersed phase, and the average particle size of the dispersed phase measured by a transmission electron microscope may be about 0.1 to about 3 μm, for example, about 0.3 to about 1 μm.

[0054] In a specific example, the molten blend may be included in an amount of about 15 to about 30 parts by weight, for example, about 17 to about 29 parts by weight, with respect to about 100 parts by weight of the block polypropylene resin. If the content of the molten blend is less than about 15 parts by weight with respect to about 100 parts by weight of the block polypropylene resin, there is a risk that the impact resistance, etc. of the polypropylene resin composition may be reduced, and if it exceeds about 30 parts by weight, there is a risk that the rigidity, heat resistance, fluidity, etc. of the polypropylene resin composition may be reduced.

[0055]

[0056] (C) RTPO

[0057] RTPO (Reactor made ThermoPlastic Olefin) according to one embodiment of the present invention is applied together with block polypropylene resin, a melt blend of ultra-low density polyethylene and styrene-based thermoplastic elastomer and talc, etc., and can improve the impact resistance, stiffness, heat resistance, dimensional stability, and balance of physical properties of the polypropylene resin composition, and can use RTPO applied to a conventional thermoplastic resin composition.

[0058] In a specific example, the RTPO is a propylene-based block copolymer with a high content of ethylene-propylene rubber, wherein the content of ethylene-propylene rubber may be about 15% by weight or more, for example, about 25 to about 50% by weight, of the total 100% by weight of the RTPO, and the melt-flow index measured under conditions of 230°C and a 2.16 kg load according to ASTM D1238 may be about 3 to about 60 g / 10 min, for example, about 20 to about 55 g / 10 min. Within the above range, the impact resistance of the polypropylene resin composition may be excellent.

[0059] In a specific example, the RTPO may be included in an amount of about 10 to about 120 parts by weight, for example, about 14 to about 115 parts by weight, with respect to about 100 parts by weight of the block polypropylene resin. If the content of the RTPO is less than about 10 parts by weight with respect to about 100 parts by weight of the block polypropylene resin, there is a risk that the impact resistance, etc. of the polypropylene resin composition will decrease, and if it exceeds about 120 parts by weight, there is a risk that the rigidity, heat resistance, etc. of the polypropylene resin composition will decrease.

[0060] In a specific example, the weight ratio of the melt blend and the RTPO may be about 1:0.5 to about 1:7, for example, about 1:0.6 to about 1:6. Within this range, the impact resistance, rigidity, heat resistance, etc. of the polypropylene resin composition may be superior.

[0061]

[0062] (D) Talc

[0063] Talc according to one embodiment of the present invention can be applied together with block polypropylene resin, ultra-low density polyethylene, a melt blend of styrene-based thermoplastic elastomer and RTPO, etc., to improve the impact resistance, stiffness, heat resistance, dimensional stability, and balance of physical properties of the polypropylene resin composition, and can use talc applied to conventional thermoplastic resin compositions.

[0064] In a specific example, the talc is a plate-shaped inorganic filler, and the average particle size measured by a particle size measuring device (Malvern mastersizer 3000) may be about 0.5 to about 3.8 μm, for example, about 1 to about 3.5 μm. Within this range, the rigidity, appearance characteristics, etc. of the polypropylene resin composition may be excellent.

[0065] In a specific example, the talc may be included in an amount of about 20 to about 45 parts by weight, for example, about 22 to about 42 parts by weight, with respect to about 100 parts by weight of the block polypropylene resin. If the content of the talc is less than about 20 parts by weight with respect to about 100 parts by weight of the block polypropylene resin, there is a risk that the rigidity, heat resistance, dimensional stability, etc. of the polypropylene resin composition will be reduced, and if it exceeds about 45 parts by weight, there is a risk that the impact resistance, fluidity, etc. of the polypropylene resin composition will be reduced.

[0066] In a specific example, the weight ratio of the RTPO and the talc may be about 1:0.2 to about 1:2, for example, about 1:0.3 to about 1:1.5. Within this range, the impact resistance, rigidity, heat resistance, dimensional stability, etc. of the polypropylene resin composition may be superior.

[0067]

[0068] A polypropylene resin composition according to one embodiment of the present invention may further include additives included in conventional thermoplastic resin compositions. Examples of such additives include, but are not limited to, flame retardants, fillers, stabilizers, lubricants, antibacterial agents, release agents, and mixtures thereof. When using such additives, the content thereof may be about 0.001 to about 40 parts by weight, for example, about 0.1 to about 10 parts by weight, per about 100 parts by weight of the block polypropylene resin, but is not limited thereto.

[0069]

[0070] A polypropylene resin composition according to one embodiment of the present invention may be in the form of pellets produced by mixing the above components and melt-extruding them using a conventional twin-screw extruder at about 150 to about 300°C, for example, about 160 to about 230°C.

[0071] In a specific example, the polypropylene resin composition may be in a form where the block polypropylene resin, the RTPO, and the talc are in the continuous phase, the ultra-low density polyethylene is in the dispersed phase, and the styrene-based thermoplastic elastomer is present at the interface between the continuous phase and the dispersed phase. Specifically, the continuous phase may be in the form where RTPO and talc are dispersed in the block polypropylene resin, respectively, and the dispersed phase (ultra-low density polyethylene) may be shown as having a core-shell form (a shell form in which the styrene-based thermoplastic elastomer covers at least a portion of the core of the ultra-low density polyethylene core).

[0072] In a specific example, the core-shell type dispersed phase may have an average particle size of about 20 to about 150 nm, for example, about 50 nm to about 120 nm, measured by a transmission electron microscope (TEM, manufacturer: JEOL, device name: JEM-1400) after staining a specimen thinned by a cryomicrotome with 0.5% ruthenium tetroxide. Within this range, the impact resistance, dimensional stability, etc. of the polypropylene resin composition may be excellent.

[0073] In a specific example, the polypropylene resin composition has a notched Izod impact strength of about 20 to about 50 kJ / m² measured at room temperature (about 23°C) according to ISO 180. 2 , for example, about 25 to about 45 kJ / m² 2 It could be.

[0074] In a specific example, the polypropylene resin composition may have a tensile strength of about 10 to about 30 MPa, for example, about 15 to about 25 MPa, of a 4 mm thick specimen measured under 50 mm / min conditions according to ISO 527-1A.

[0075] In a specific example, the polypropylene resin composition may have a flexural strength of about 15 to about 35 MPa, for example, about 20 to about 30 MPa, of a 4 mm thick specimen measured under 2 mm / min conditions according to ISO 178 standards.

[0076] In a specific example, the polypropylene resin composition may have a flexural modulus of about 1,000 to about 2,500 MPa, for example, about 1,500 to about 2,300 MPa, of a 4 mm thick specimen measured under 2 mm / min conditions according to ISO 178 standards.

[0077] In a specific example, the polypropylene resin composition may have a heat distortion temperature (HDT) of an 80 mm × 10 mm × 4 mm specimen measured under conditions of 0.45 MPa and a heating rate of 120°C / hr according to ISO 75, which is about 90 to about 110°C, for example, about 94 to about 105°C.

[0078] In a specific example, the polypropylene resin composition may have a linear expansion coefficient of about 65 to about 85 μm / m·°C, for example, about 65.5 to about 84.5 μm / m·°C, measured by increasing the temperature from -30°C to 100°C at a rate of 5°C / min according to ASTM E831 standard for a specimen of size 100 mm × 100 mm × 4 mm.

[0079]

[0080] The molded article according to the present invention is formed from the polypropylene resin composition. The polypropylene resin composition may be manufactured in the form of pellets, and the manufactured pellets may be manufactured into various molded articles (products) through various molding methods such as injection molding, extrusion molding, vacuum molding, and casting molding. Such molding methods are well known to those skilled in the art to which the present invention pertains.

[0081] In a specific example, the molded article has excellent impact resistance, rigidity, heat resistance, dimensional stability, and a balance of these physical properties, making it useful for automotive interior / exterior materials, home appliance housings, etc.

[0082]

[0083] The present invention is to be explained more specifically through the following examples, but these examples are for illustrative purposes only and should not be interpreted as limiting the invention.

[0084]

[0085] Examples

[0086] The specifications of each component used in the examples and comparative examples below are as follows.

[0087] (A) Block polypropylene resin

[0088] Block polypropylene resin (B-PP, manufacturer: Lotte Chemical, melt-flow index: approximately 75 g / 10 min) was used.

[0089] (B) Ultra-low density polyethylene and styrene-based thermoplastic elastomers

[0090] (B1) Density is approximately 0.885 g / cm³ 3 A melt blend was used in which 85 wt% of ultra-low density polyethylene (manufacturer: DL CHEMICAL, product name: VL8805) and 15 wt% of styrene-ethylene-butylene-styrene block copolymer (manufacturer: SINOPEC, product name: YH-503T) were melt-extruded at approximately 200°C using a twin-screw extruder.

[0091] (B2) A melt blend was used in which 85 wt% of ultra-low density polyethylene (manufacturer: LG CHEM, product name: LC565) with a density of about 0.865 g / cm3 and 15 wt% of styrene-ethylene-butylene-styrene block copolymer (manufacturer: SINOPEC, product name: YH-503T) were melt-extruded at about 200°C using a twin-screw extruder.

[0092] (B3) Density is approximately 0.912 g / cm³ 3 A melt blend was used in which 85 wt% of ultra-low density polyethylene (manufacturer: DOW CHEMICAL, product name: ATTANE 4206) and 15 wt% of styrene-ethylene-butylene-styrene block copolymer (manufacturer: SINOPEC, product name: YH-503T) were melt-extruded at approximately 200°C using a twin-screw extruder.

[0093] (B4) Density is approximately 0.885 g / cm³ 3A melt blend was used in which 99.5 wt% of ultra-low density polyethylene (manufacturer: DL CHEMICAL, product name: VL8805) and 0.5 wt% of styrene-ethylene-butylene-styrene block copolymer (manufacturer: SINOPEC, product name: YH-503T) were melt-extruded at approximately 200°C using a twin-screw extruder.

[0094] (B5) Density is approximately 0.885 g / cm³ 3 A melt blend was used in which 50 wt% of ultra-low density polyethylene (manufacturer: DL CHEMICAL, product name: VL8805) and 50 wt% of styrene-ethylene-butylene-styrene block copolymer (manufacturer: SINOPEC, product name: YH-503T) were melt-extruded at approximately 200°C using a twin-screw extruder.

[0095] (B6) Density is approximately 0.885 g / cm³ 3 85 wt% of ultra-low density polyethylene (manufacturer: DL CHEMICAL, product name: VL8805) and 15 wt% of styrene-ethylene-butylene-styrene block copolymer (manufacturer: SINOPEC, product name: YH-503T) were simply mixed.

[0096] (C) RTPO

[0097] RTPO (Manufacturer: Hanwha Total Energys, Product Name: BI7300, Melt-flow index: approx. 30 g / 10 min) was used.

[0098] (D) Talc

[0099] Talc (Manufacturer: KOCH, Product Name: KC-5000, Average Particle Size: Approx. 3.5 μm) was used.

[0100]

[0101] Examples 1 to 8 and Comparative Examples 1 to 11

[0102] Each of the above components was added in the amounts listed in Tables 1, 2, and 3 below, and pellets were prepared by extrusion at approximately 210°C. A twin-screw extruder with L / D=40 and a diameter of 48 mm was used for extrusion. The prepared pellets were dried at approximately 80°C for at least 2 hours, and then specimens were prepared by injection molding using a 110-ton injection molding machine (molding temperature: approximately 210°C, mold temperature: approximately 50°C). The physical properties of the prepared specimens were evaluated using the following method, and the results are shown in Tables 1, 2, and 3 below.

[0103]

[0104] Methods for measuring physical properties

[0105] (1) Notched Izod impact strength (unit: kJ / m 2 According to ISO 180 standards, notched Izod impact strength was measured at room temperature (approx. 23℃).

[0106] (2) Tensile strength (unit: MPa): According to ISO 527-1A standard, the tensile strength of a 4 mm thick specimen was measured under 50 mm / min conditions.

[0107] (3) Flexural strength (unit: MPa): According to ISO 178 standards, the flexural strength of a 4 mm thick specimen was measured under conditions of 2 mm / min.

[0108] (4) Flexural modulus (unit: MPa): According to ISO 178 standards, the flexural modulus of a 4 mm thick specimen was measured under conditions of 2 mm / min.

[0109] (5) Heat distortion temperature (unit: ℃): According to ISO 75, the heat distortion temperature (HDT) of a specimen of size 80 mm × 10 mm × 4 mm was measured under conditions of 0.45 MPa and a heating rate of 120℃ / hr.

[0110] (6) Coefficient of linear expansion (unit: μm / m·℃): According to ASTM E831 standards, the coefficient of linear expansion of a specimen of size 100 mm × 100 mm × 4 mm was measured by increasing the temperature from -30℃ to 100℃ at a rate of 5℃ / min.

[0111]

[0112] Example 12345678(A) (parts by weight) 100 100 100 100 100 100 100 100 100 (B) (parts by weight) (B1) 17.2 26.2 28.3 22.0 19.6 26.5 22.6 18.6 (B2) -------- (B3) -------- (B4) -------- (B5) -------- (B6) -------- (C) (parts by weight) 90.9 91.9 88.9 14.6 114.8 21.2 51.3 106.1 (D) (parts by weight) 36.9 39.4 40.4 22.0 42.0 26.5 30.8 39.8 Notch Izod Impact Strength 36.5 44.5 30.4 33.7 33.7 35.3 38.9 38.6 Tensile Strength 19.6 18.9 19.5 19.1 17.7 19.7 20.0 18.4 Flexural Strength 28.2 27.5 27.9 30.4 26.9 29.4 30.6 28.0 Flexural Modulus 1,730 1,680 1,740 1,850 1,670 2,000 1,800 1,720 Heat Distortion Temperature 9 795 100 10 494 103 10596 Linear Expansion Coefficient 74.1 72.3 73.2 84.2 65.7 79.7 76.9 68.7

[0113]

[0114] Comparative Example 123456(A) (parts by weight) 100 100 100 100 100 100 100 (B) (parts by weight) (B1) 1035 ---- (B2) -- 26.2 -- (B3) -- 26.2 -- (B4) ---- 26.2 -- (B5) ---- 26.2 (B6) ---- -- (C) (parts by weight) 91.99 1.99 1.99 1.99 1.99 1.99 1.9 (D) (parts by weight) 39.4 39.4 39.4 39.4 39.4 39.4 Notch Izod Impact Strength 16.4 5.5 5.7 50.3 19.5 14.4 25.7 Tensile Strength 20.4 15.7 17.2 19.9 18.7 14.3 Flexural Strength 3 1.2 24.2 26.3 31.9 31.5 23.6 Flexural Modulus 1.8 20 950 1.3 40 1.6 90 1.6 20 850 Heat Distortion Temperature 10 7 8 89 59 69 485 Linear Expansion Coefficient 7 3.7 74.5 90.5 88.7 75 478.7

[0115]

[0116] Comparative Example 7891011(A) (parts by weight) 100100100100100(B) (parts by weight)(B1)-22.019.622.019.6(B2)-----(B3)-----(B4)-----(B5)-----(B6)26.2----(C) (parts by weight) 91.9513014.6114.8(D) (parts by weight) 39.422.042.01055 Notch Izod Impact Strength 18.7 11.2 49.7 48.5 7.2 Tensile Strength 18.4 22.1 15.6 17.1 21.3 Flexural Strength 28.7 33.0 23.2 24.0 31.0 Flexural Modulus 168 0 225 0 89 0 92 0 20 20 Heat Distortion Temperature 98 10 98 48 610 5 Linear Expansion Coefficient 83.9 84.0 70.1 90.1 62.9

[0117]

[0118] From the above results, it can be seen that the polypropylene resin composition of the present invention exhibits excellent impact resistance (notched Izod impact strength), stiffness (tensile strength, flexural strength, flexural modulus), heat resistance (heat distortion temperature), dimensional stability (coefficient of linear expansion), and the balance of these physical properties.

[0119] On the other hand, in Comparative Example 1, where the content of the molten blend of ultra-low density polyethylene and styrene-based thermoplastic elastomer is less than the range of the present invention, it can be seen that impact resistance, etc. is reduced, and in Comparative Example 2, where the content of the molten blend of ultra-low density polyethylene and styrene-based thermoplastic elastomer exceeds the range of the present invention, it can be seen that stiffness, heat resistance, etc. are reduced. In the case of Comparative Example 3, which uses a melt blend (B2) with ultra-low density polyethylene having a density below the range of the present invention instead of the melt blend of the present invention, it can be seen that dimensional stability, etc. is reduced; in the case of Comparative Example 4, which uses a melt blend (B3) with ultra-low density polyethylene having a density exceeding the range of the present invention, it can be seen that impact resistance, dimensional stability, etc. are reduced; in the case of Comparative Example 5, which uses a melt blend (B4) with an ultra-low density polyethylene content exceeding the range of the present invention, it can be seen that impact resistance, etc. is reduced; in the case of Comparative Example 6, which uses a melt blend (B5) with an ultra-low density polyethylene content below the range of the present invention, it can be seen that rigidity, heat resistance, etc. are reduced; and in the case of Comparative Example 7, which uses a simple mixture (B6) of ultra-low density polyethylene and a styrene-based thermoplastic elastomer, it can be seen that impact resistance, etc. is reduced.

[0120] In addition, in Comparative Example 8, where the RTPO content is less than the range of the present invention, it can be seen that impact resistance, etc. is reduced; in Comparative Example 9, where the RTPO content exceeds the range of the present invention, it can be seen that rigidity, heat resistance, etc. are reduced; in Comparative Example 10, where the talc content is less than the range of the present invention, it can be seen that rigidity, heat resistance, dimensional stability, etc. are reduced; and in Comparative Example 11, where the talc content exceeds the range of the present invention, it can be seen that impact resistance, etc. is reduced.

[0121]

[0122] The present invention has been described above with reference to embodiments. Those skilled in the art will understand that the present invention may be embodied in modified forms without departing from the essential characteristics of the invention. Therefore, the disclosed embodiments should be considered in an illustrative rather than a restrictive sense. The scope of the invention is defined by the claims, not by the foregoing description, and all variations within the scope of equivalents should be interpreted as being included in the invention.

Claims

1. About 100 parts by weight of block polypropylene resin; Density measured according to ISO 1183-1 is approximately 0.88 to approximately 0.91 g / cm³ 3 About 15 to about 30 parts by weight of a melt blend of about 65 to about 99 weight% of phosphorus ultra-low density polyethylene and about 1 to about 35 weight% of a styrene-based thermoplastic elastomer; About 10 to about 120 parts by weight of RTPO; and A polypropylene resin composition characterized by comprising about 20 to about 45 parts by weight of talc.

2. A polypropylene resin composition according to claim 1, characterized in that the block polypropylene resin has a melt-flow index of about 10 to about 150 g / 10 min, measured under conditions of 230°C and a 2.16 kg load in accordance with ASTM D1238.

3. A polypropylene resin composition according to claim 1 or 2, wherein the ultra-low density polyethylene has a melt flow index of about 1 to about 20 g / 10 min measured at 230°C and a 2.16 kg load condition in accordance with ASTM D1238.

4. A polypropylene resin composition according to any one of claims 1 to 3, wherein the styrene-based thermoplastic elastomer comprises one or more of styrene-ethylene-butylene-styrene block copolymer, styrene-ethylene-propylene-styrene block copolymer, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, and styrene-butadiene-butylene-styrene block copolymer.

5. A polypropylene resin composition according to any one of claims 1 to 4, wherein the styrene-based thermoplastic elastomer has a styrene-based monomer content of about 5 to about 50 weight%.

6. A polypropylene resin composition according to any one of claims 1 to 5, wherein the styrene-based thermoplastic elastomer has a weight-average molecular weight of about 100,000 to about 450,000 g / mol.

7. A polypropylene resin composition according to any one of claims 1 to 6, wherein the RTPO is a propylene-based block copolymer having an ethylene-propylene rubber content of about 15 weight% or more and a melt flow index of about 3 to about 60 g / 10 min measured at 230°C and a 2.16 kg load condition according to ASTM D1238.

8. A polypropylene resin composition according to any one of claims 1 to 7, wherein the talc has an average particle size of about 0.5 to about 3.8 μm as measured by a particle size measuring device.

9. A polypropylene resin composition according to any one of claims 1 to 8, wherein the polypropylene resin composition is characterized in that the block polypropylene resin, the RTPO, and the talc are in the continuous phase, the ultra-low density polyethylene is in the dispersed phase, and the styrene-based thermoplastic elastomer is present at the interface between the continuous phase and the dispersed phase.

10. In any one of claims 1 to 9, the polypropylene resin composition has a notched Izod impact strength of about 20 to about 50 kJ / m² as measured according to ISO 180. 2 A polypropylene resin composition characterized by being.

11. A polypropylene resin composition according to any one of claims 1 to 10, wherein the polypropylene resin composition has a tensile strength of about 10 to about 30 MPa of a 4 mm thick specimen measured under 50 mm / min conditions in accordance with ISO 527-1A.

12. A polypropylene resin composition according to any one of claims 1 to 11, wherein the polypropylene resin composition has a flexural strength of about 15 to about 35 MPa of a 4 mm thick specimen measured under 2 mm / min conditions according to ISO 178 standards, and a flexural modulus of about 1,000 to about 2,500 MPa of a 4 mm thick specimen measured under 2 mm / min conditions according to ISO 178 standards.

13. A polypropylene resin composition according to any one of claims 1 to 12, wherein the polypropylene resin composition is characterized by having a heat distortion temperature (HDT) of an 80 mm × 10 mm × 4 mm specimen measured under conditions of 0.45 MPa and a heating rate of 120℃ / hr in accordance with ISO 75, of about 90 to about 110℃.

14. A polypropylene resin composition according to any one of claims 1 to 13, wherein the polypropylene resin composition is characterized by having a linear expansion coefficient of about 65 to about 85 μm / m·℃ for a specimen of size 100 mm × 100 mm × 4 mm measured by increasing the temperature from -30℃ to 100℃ at a rate of 5℃ / min in accordance with ASTM E831.

15. A molded article characterized by being formed from a polypropylene resin composition according to any one of claims 1 to 14.