Polyolefin composition having high stiffness and high toughness and

Abstract

The present invention relates to a polyolefin composition comprising, based on the weight of the polyolefin composition, A) 50-90% by weight of a polypropylene impact copolymer comprising a first polypropylene impact copolymer and a second polypropylene impact copolymer, B) 5-35% by weight of a polyolefin elastomer, and C) 5-30% by weight of a filler, wherein the first polypropylene impact copolymer comprises from 90 to 94% by weight of a homo-polypropylene and from 6 to 10% by weight of an ethylene-alpha-olefin copolymer, based on the weight of the first polypropylene impact copolymer, and wherein the second polypropylene impact copolymer comprises from 78 to 88% by weight of a homo-polypropylene and from 12 to 22% by weight of an ethylene-alpha-olefin copolymer, based on the weight of the second polypropylene impact copolymer. The invention also relates to an article made from the polyolefin composition.

Description

Technical Field

[0001] The present invention relates to a polyolefin composition and an article made from the polyolefin composition. Background Art

[0002] Due to the trade-off between toughness and stiffness, the use of pure polyolefin materials in engineering applications is relatively limited. For example, in common industrial applications, polyethylene materials have higher toughness and lower stiffness, so they are mostly used to produce consumables such as packaging bottles, bucket toys, etc. with lower physical property requirements. Polypropylene has higher stiffness than polyethylene, but lower toughness than polyethylene, so it is mostly used in white appliance housings. For automotive component materials with higher requirements, existing industrial solutions are mostly based on modified materials with engineering plastics or polyolefins as the base material.

[0003] The industry has developed several solutions to improve the overall physical properties of polypropylene materials. The most widely used solution is to improve the overall physical properties of polypropylene materials by adding fillers and elastomers at the same time. Fillers are responsible for improving the rigidity of polypropylene materials, and elastomers are responsible for improving the toughness of polypropylene materials. However, the modification technology is also subject to the influence of polypropylene substrates and blending technology, as well as the formulation ratio, and its ability to improve physical properties has its limitations. Therefore, materials with high physical property requirements are still the focus of the industry to be broken through.

[0004] In addition, as the demand for reducing automobile energy consumption becomes higher and higher, lightweight automobile parts have become a trend. Therefore, materials suitable for thin-wall injection molding design to obtain lightweight parts are another key point to be broken through in the industry.

[0005] Therefore, there is still a need to find a polyolefin composition that has both high rigidity and high toughness and is convenient for manufacturing lightweight parts. Summary of the invention

[0006] To this end, the present invention provides a polyolefin composition comprising, based on the weight of the polyolefin composition:

[0007] A) 50 to 90 wt.% of a polypropylene impact copolymer, the polypropylene impact copolymer comprising a first polypropylene impact copolymer and a second polypropylene impact copolymer,

[0008] B) 5 to 35% by weight of a polyolefin elastomer, and

[0009] C) 5-30% by weight of fillers,

[0010] wherein the first polypropylene impact copolymer comprises 90-94 wt % homopolypropylene and 6-10 wt % ethylene-α-olefin copolymer, based on the weight of the first polypropylene impact copolymer, and

[0011] The second polypropylene impact copolymer comprises 78-88 wt % of homopolypropylene and 12-22 wt % of ethylene-α-olefin copolymer, based on the weight of the second polypropylene impact copolymer.

[0012] The present invention also relates to an article made from the polyolefin composition.

[0013] The polyolefin composition and its products of the present invention have the following beneficial effects: (1) the polyolefin composition and its products have excellent rigidity and toughness; (2) the polyolefin composition has a higher melt flow rate and is more suitable for thin-wall injection molding design, thereby obtaining lightweight parts, making it particularly suitable for lightweight applications, such as automobile bumpers. DETAILED DESCRIPTION

[0014] Polyolefin composition

[0015] According to the present invention, the polyolefin composition comprises, based on the weight of the polyolefin composition:

[0016] A) 50 to 90 wt.% of a polypropylene impact copolymer, the polypropylene impact copolymer comprising a first polypropylene impact copolymer and a second polypropylene impact copolymer,

[0017] B) 5 to 35% by weight of a polyolefin elastomer, and

[0018] C) 5-30% by weight of fillers,

[0019] wherein the first polypropylene impact copolymer comprises 90-94 wt % homopolypropylene and 6-10 wt % ethylene-α-olefin copolymer, based on the weight of the first polypropylene impact copolymer, and

[0020] The second polypropylene impact copolymer comprises 78-88 wt % of homopolypropylene and 12-22 wt % of ethylene-α-olefin copolymer, based on the weight of the second polypropylene impact copolymer.

[0021] The sum of the percentages of the various components in the polyolefin composition is 100% by weight.

[0022] According to the present invention, the polyolefin composition has a flexural modulus measured according to ISO 178 of from 1550 MPa to 2200 MPa.

[0023] According to the present invention, the polyolefin composition has a thermal conductivity of 45-70 kJ / m measured at 23°C according to ISO 180 / 1eA. 2 Izod notched impact strength.

[0024] According to the present invention, the polyolefin composition has a thermal conductivity of 50-80 kJ / m 2 The simply supported beam notched impact strength.

[0025] According to the present invention, the polyolefin composition has a melt flow rate measured according to ISO 1133 of 20 to 50 g / 10 min.

[0026] According to the present invention, the polyolefin composition has a tensile strength measured according to ISO 527 of 15-40 MPa.

[0027] According to the present invention, the polyolefin composition has a multiaxial impact energy absorption peak value (MAI ASTM) of 15-40 J measured at 23° C. according to ASTM D3763 multiaxial impact test.

[0028] The polyolefin composition of the present invention can be formulated in any mixer commonly used in the art, for example in a twin-screw extruder (such as a Leistriz twin-screw extruder with a screw diameter of 40 mm).

[0029] Polypropylene impact copolymer

[0030] According to the present invention, the polyolefin composition comprises 50-90 wt% of a polypropylene impact copolymer, such as 50-70 wt% of a polypropylene impact copolymer, based on the weight of the polyolefin composition. The polypropylene impact copolymer comprises a first polypropylene impact copolymer and a second polypropylene impact copolymer.

[0031] In one embodiment, the polypropylene impact copolymer comprises 60 to 95 weight percent of a first polypropylene impact copolymer and 5 to 40 weight percent of a second polypropylene impact copolymer, based on the total weight of the polypropylene impact copolymer.

[0032] In a preferred embodiment, the polypropylene impact copolymer comprises 70-90 wt% of a first polypropylene impact copolymer and 10-30 wt% of a second polypropylene impact copolymer, based on the total weight of the polypropylene impact copolymer.

[0033] According to the present invention, the first polypropylene impact copolymer has an intrinsic viscosity greater than 4 dl / g, such as greater than 4 dl / g to 10 dl / g.

[0034] According to the present invention, the first polypropylene impact copolymer has a melt flow rate of 90 to 140 g / 10 min, for example, 100 to 130 g / 10 min, measured according to ASTM D12382 at 30°C / 2.16 kg.

[0035] According to the present invention, the second polypropylene impact copolymer has a melt flow rate of 1 to 15 g / 10 min, such as 1 to 10 g / 10 min, measured according to ASTM D12382 at 30°C / 2.16 kg.

[0036] According to the present invention, the first polypropylene impact copolymer and the second polypropylene impact copolymer each independently have a strength of 0.85-0.95 g / cm 3 density.

[0037] According to the present invention, the first polypropylene impact copolymer has a flexural modulus measured according to ISO 178 of 1500 to 2100 MPa.

[0038] According to the present invention, the second polypropylene impact copolymer has a flexural modulus measured according to ISO 178 of 800 MPa to 1300 MPa.

[0039] In one embodiment, in the first polypropylene impact copolymer and the second polypropylene impact copolymer, the homopolypropylene each independently has a tacticity index of 80% or more, or a tacticity index of 85% or more, or a tacticity index of 90% or more, or a tacticity index of 95% or more.

[0040] In one embodiment, in the first polypropylene impact copolymer and the second polypropylene impact copolymer, the α-olefin in the ethylene-α-olefin copolymer independently has 2 to 8 carbon atoms. Preferably, the α-olefin is selected from propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene or 1-octene. In a preferred embodiment, the α-olefin is propylene.

[0041] In one embodiment, in the first and second polypropylene impact copolymers, the ethylene-α-olefin copolymers each independently comprise 10-75 wt% ethylene derived monomer units, such as 20-40 wt% or 30-50 wt% ethylene derived monomer units.

[0042] In one embodiment, in the first polypropylene impact copolymer and the second polypropylene impact copolymer, the ethylene-α-olefin copolymer each independently has an intrinsic viscosity of 1.5 to 8.5 dl / g, such as 2.0 to 4.0 dl / g.

[0043] Herein, intrinsic viscosity is measured using a Crystex instrument from Polymer Char according to the soluble fraction test method.

[0044] According to the present invention, the ethylene-α-olefin copolymer is present as a dispersed phase in the homopolypropylene continuous phase of the polypropylene impact copolymer.

[0045] Each polypropylene impact copolymer can be prepared according to conventional methods in the art. In the method for preparing the polypropylene impact copolymer, the polymerization temperature is preferably 200° C. or lower, more preferably 100° C. or lower. In the method for preparing the polypropylene impact copolymer, the polymerization pressure is preferably 10 MPa or lower, more preferably 5 MPa or lower.

[0046] According to the present invention, the method for preparing the polypropylene impact copolymer can be a continuous polymerization method or a batch polymerization method. In addition, the polymerization reaction is carried out in two stages, or in three or more stages.

[0047] When preparing a polypropylene impact copolymer, it can be prepared by two or more stage polymerization, and the copolymer can generally be obtained by preparing homopolypropylene using a Ziegler-Natta catalyst in the first stage and copolymerizing ethylene and α-olefin in the second stage.

[0048] In one embodiment, polymerization is performed in the first stage of preparing the first polypropylene impact copolymer by adjusting the polymerization temperature and the residence time so that the proportion of the homopolypropylene continuous phase is in the range of 90-94 wt %, and then ethylene and α-olefin are introduced and polymerized in the second stage so that the proportion of the dispersed phase is in the range of 6-10 wt %.

[0049] In one embodiment, polymerization is performed in the first stage of preparing the second polypropylene impact copolymer by adjusting the polymerization temperature and the residence time so that the proportion of the homopolypropylene continuous phase is in the range of 78-88 wt %, and then ethylene and α-olefin are introduced and polymerized in the second stage so that the proportion of the dispersed phase is in the range of 12-22 wt %.

[0050] The stage of preparing polypropylene can be carried out in two or more series reactors, each reactor is operated under the same conditions (such as hydrogen level, comonomer, temperature, type or percentage of external electron donor, etc.) to prepare the same type of polypropylene, or is operated under different conditions to prepare polypropylene such as bimodal molecular weight distribution. Similarly, there can be two or more reactors in series for the second stage, and these reactors can be operated under the same conditions to prepare the same type of ethylene-alpha-olefin copolymers, or are operated under different conditions to prepare ethylene-alpha-olefin copolymers with differences in some features such as molecular weight or comonomer content. Most preferably, the first stage of preparing the continuous phase of polypropylene is carried out in a bulk polymerization process, and the preparation of the ethylene-alpha-olefin copolymer finely dispersed in the continuous phase range is carried out in one or more gas phase reactors in the second stage.

[0051] The polymerization temperature in both the first stage and the second stage is preferably 200° C. or less, more preferably 100° C. or less. The polymerization pressure is preferably 10 MPa or less, more preferably 5 MPa or less. In addition, the polymerization time per polymerization stage or the residence time in the case of continuous polymerization is usually 0.25 to 5 hours.

[0052] Examples of the polymerization method include a solution polymerization method in which an inert hydrocarbon compound such as cyclohexane and heptane is used as a solvent, a bulk polymerization method in which liquefied propylene is used, and a gas phase polymerization method in which no liquid alkane is involved. Examples of preferred polymerization methods include both bulk polymerization methods and gas phase polymerization methods. The polymerization methods are known to those skilled in the art.

[0053] In a preferred embodiment, the first polypropylene impact copolymer is, for example, ExxonMobil TM PP7945E1.

[0054] In a preferred embodiment, the second polypropylene impact copolymer is, for example, ExxonMobil TM PP 7032E3.

[0055] Polyolefin elastomer

[0056] According to the present invention, the polyolefin composition comprises 5-35 wt% of polyolefin elastomer, such as 15-30 wt% of polyolefin elastomer, based on the weight of the polyolefin composition.

[0057] In one embodiment, the polyolefin elastomer has a melt flow rate of 1 to 15 g / 10 min, measured according to ASTM D1238 190° C. / 2.16 kg.

[0058] In one embodiment, the polyolefin elastomer has a glass transition temperature of -55°C to -50°C and a melting point of 40°C to 90°C.

[0059] The polyolefin elastomer comprises one or more ethylene-based elastomers. The polyolefin elastomer comprises monomer units derived from ethylene and monomer units derived from C 3 -C 12 Monomer units of one or more comonomers of an α-olefin. The α-olefin comonomer may be selected from propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene or 1-decene. In a preferred embodiment, the α-olefin is 1-octene.

[0060] The polyolefin elastomer may include at least 70 weight percent, at least 75 weight percent, at least 80 weight percent, at least 81 weight percent, at least 82 weight percent, or at least 83 weight percent ethylene-derived monomer units, wherein the weight percent is based on the total weight of the ethylene-derived monomer units and the alpha-olefin-derived monomer units. The polyolefin elastomer may include up to 95 weight percent, up to 94 weight percent, up to 93 weight percent, up to 92 weight percent, up to 90 weight percent, or up to 88 weight percent ethylene-derived monomer units, wherein the weight percent is based on the total weight of the ethylene-derived monomer units and the alpha-olefin-derived monomer units.

[0061] The polyolefin elastomer may include at least 5 wt%, at least 6 wt%, at least 7 wt%, at least 8 wt%, at least 9 wt%, at least 10 wt%, or at least 12 wt% α-olefin derived monomer units, wherein the weight percentage is based on the total weight of ethylene derived monomer units and α-olefin derived monomer units. The polyolefin elastomer may include up to 30 wt%, up to 25 wt%, up to 22 wt%, up to 20 wt%, up to 19 wt%, up to 18 wt%, or up to 17 wt% α-olefin derived monomer units, wherein the weight percentage is based on the total weight of ethylene derived monomer units and α-olefin derived monomer units. In some embodiments, the polyolefin elastomer may include 5-25 wt% α-olefin derived monomer units, or 9-18 wt% α-olefin derived monomer units, wherein the weight percentage is based on the total weight of ethylene derived monomer units and α-olefin derived monomer units.

[0062] In a preferred embodiment, the polyolefin elastomer is an ethylene-octene copolymer, such as Engage 8200 from Dow.

[0063] In a preferred embodiment, the polyolefin elastomer may have a weight average molecular weight (Mw) of 50,000 to 5,000,000 g / mol, 75,000 to 1,000,000 g / mol, 100,000 to 500,000 g / mol, or 125000 to 300000 g / mol. The molecular weight distribution (MWD, equal to Mw / Mn) of the polyolefin elastomer may be 1 to 40, 1 to 15, 1.8 to 5, or 1.8 to 3.

[0064] The polyolefin elastomer can be prepared according to conventional methods in the art. For example, the polyolefin elastomer can be prepared by reacting the monomers at a temperature of 0° C. to 200° C. for a period of 1 minute to 10 hours in the presence of a catalyst system. Preferably, uniform conditions are used, such as a continuous solution process or a bulk polymerization process using excess monomer as a diluent. The catalyst system used to prepare the polyolefin elastomer can be a metallocene-based compound.

[0065] filler

[0066] According to the present invention, the polyolefin composition comprises 5-30 wt% filler, such as 10-25 wt% filler, based on the weight of the polyolefin composition.

[0067] In one embodiment, the filler includes talc, calcium carbonate, calcium hydroxide, barium sulfate, mica, calcium silicate, clay, kaolin, silica, alumina, wollastonite, magnesium carbonate, magnesium hydroxide, titanium oxide, zinc oxide, zinc sulfate, or a combination thereof.

[0068] In a preferred embodiment, the filler is talc, which may have a size of about 1 μm to about 100 μm. The talc is, for example, HTP Ultra 5L from Imifabi.

[0069] According to the present invention, the polyolefin composition may further comprise additives generally known in the art, such as dispersants, lubricants, flame retardants, antioxidants, antistatic agents, light stabilizers, ultraviolet light absorbers, carbon black, nucleating agents, plasticizers and coloring agents such as dyes or pigments. The additive may be present in the polyolefin composition in an amount of 0.1-5% by weight, based on the weight of the polyolefin composition.

[0070] In a preferred embodiment, the polyolefin composition comprises, based on the weight of the polyolefin composition:

[0071] A) 50 to 90 wt.% of a polypropylene impact copolymer, the polypropylene impact copolymer comprising a first polypropylene impact copolymer and a second polypropylene impact copolymer,

[0072] B) 5 to 35% by weight of a polyolefin elastomer, and

[0073] C) 5-30% by weight of fillers,

[0074] wherein the first polypropylene impact copolymer comprises 90-94 wt % of homopolypropylene and 6-10 wt % of ethylene-α-olefin copolymer, based on the weight of the first polypropylene impact copolymer,

[0075] wherein the second polypropylene impact copolymer comprises 78-88 wt% homopolypropylene and 12-22 wt% ethylene-α-olefin copolymer, based on the weight of the second polypropylene impact copolymer, and

[0076] The polypropylene impact copolymer comprises 60-95 wt % of a first polypropylene impact copolymer and 5-40 wt % of a second polypropylene impact copolymer, based on the total weight of the polypropylene impact copolymer.

[0077] In yet another preferred embodiment, the polyolefin composition comprises, based on the weight of the polyolefin composition:

[0078] A) 50 to 70 wt.% of a polypropylene impact copolymer, the polypropylene impact copolymer comprising a first polypropylene impact copolymer and a second polypropylene impact copolymer,

[0079] B) 15-30% by weight of a polyolefin elastomer, and

[0080] C) 10-25% by weight of fillers,

[0081] wherein the first polypropylene impact copolymer comprises 90-94 wt % of homopolypropylene and 6-10 wt % of ethylene-α-olefin copolymer, based on the weight of the first polypropylene impact copolymer,

[0082] wherein the second polypropylene impact copolymer comprises 78-88 wt% homopolypropylene and 12-22 wt% ethylene-α-olefin copolymer, based on the weight of the second polypropylene impact copolymer, and

[0083] The polypropylene impact copolymer comprises 60-95 wt % of a first polypropylene impact copolymer and 5-40 wt % of a second polypropylene impact copolymer, based on the total weight of the polypropylene impact copolymer.

[0084] In yet another preferred embodiment, the polyolefin composition comprises, based on the weight of the polyolefin composition:

[0085] A) 50 to 70 wt.% of a polypropylene impact copolymer, the polypropylene impact copolymer comprising a first polypropylene impact copolymer and a second polypropylene impact copolymer,

[0086] B) 15-30% by weight of a polyolefin elastomer, and

[0087] C) 10-25% by weight of fillers,

[0088] wherein the first polypropylene impact copolymer comprises 90-94 wt % of homopolypropylene and 6-10 wt % of ethylene-α-olefin copolymer, based on the weight of the first polypropylene impact copolymer,

[0089] wherein the second polypropylene impact copolymer comprises 78-88 wt% homopolypropylene and 12-22 wt% ethylene-α-olefin copolymer, based on the weight of the second polypropylene impact copolymer, and

[0090] The polypropylene impact copolymer comprises 70-90 wt % of a first polypropylene impact copolymer and 10-30 wt % of a second polypropylene impact copolymer, based on the total weight of the polypropylene impact copolymer.

[0091] Products

[0092] The present invention relates to an article made of the polyolefin composition. The polyolefin composition disclosed herein can be used to prepare any article, such as instrument components and automotive components. Such components can be made by common plastic preparation processes, such as thermoforming, blow molding or injection molding. Preferably, the polyolefin composition of the present invention can be used for (injection) molding automotive components, i.e. automotive interior or exterior components. The term "automotive component" used in the present invention means that it is a molded three-dimensional article for automotive interior or exterior. Typical automotive components are bumpers, body panels, rocker panels, side trims, pillars, pedal assists, spoilers, fenders, instrument panels, etc. The term "exterior" means that the article is not part of the automotive interior, but part of the automotive exterior. Therefore, preferred automotive exterior components are selected from bumpers, pedal assists, body panels, fenders and spoilers. In contrast, the term "interior" means that the article is part of the automotive interior, not part of the automotive exterior. Therefore, preferred automotive interior components are selected from instrument panels, pillars and glove boxes.

[0093] In order to mix the individual components of the polyolefin composition, conventional processing blending equipment can be used, for example internal mixer, two-roll rubber mill, co-kneader or twin screw extruder. The polymeric material coming out of the extruder is generally in the form of pellets. Preferably these pellets are further processed then, for example by injection molding to produce goods, for example automotive interior or exterior components (such as automobile bumpers).

[0094] According to the present invention, the article made from the polyolefin composition has a flexural modulus measured according to ISO 178 of 1550 MPa to 2200 MPa.

[0095] According to the present invention, the article made of the polyolefin composition has a thermal conductivity of 45-70 kJ / m3 measured at 23°C according to ISO 180 / 1eA. 2 Izod notched impact strength.

[0096] According to the present invention, the article made of the polyolefin composition has a thermal conductivity of 50-80 kJ / m3 measured at 23°C according to ISO 179 / 1eA. 2 The simply supported beam notched impact strength.

[0097] According to the present invention, the article made from the polyolefin composition has a melt flow rate measured according to ISO 1133 of 20 to 50 g / 10 min.

[0098] According to the present invention, the article made from the polyolefin composition has a tensile strength measured according to ISO 527 of 15-40 MPa.

[0099] The various descriptive elements and numerical ranges describing the polyolefin compositions may be combined with other descriptive elements and numerical ranges to describe the invention; furthermore, for a given element, any upper numerical limit may be combined with any lower numerical limit described herein.

[0100] Those skilled in the art can more easily understand the present invention according to the following embodiments:

[0101] Embodiment 1. A polyolefin composition comprising, based on the weight of the polyolefin composition:

[0102] A) 50 to 90 wt.% of a polypropylene impact copolymer, the polypropylene impact copolymer comprising a first polypropylene impact copolymer and a second polypropylene impact copolymer,

[0103] B) 5 to 35% by weight of a polyolefin elastomer, and

[0104] C) 5-30% by weight of fillers,

[0105] wherein the first polypropylene impact copolymer comprises 90-94 wt % homopolypropylene and 6-10 wt % ethylene-α-olefin copolymer, based on the weight of the first polypropylene impact copolymer, and

[0106] The second polypropylene impact copolymer comprises 78-88 wt % of homopolypropylene and 12-22 wt % of ethylene-α-olefin copolymer, based on the weight of the second polypropylene impact copolymer.

[0107] Embodiment 2. The polyolefin composition of embodiment 1, wherein the first polypropylene impact copolymer has a melt flow rate of 90 to 140 g / 10 min as measured according to ASTM D1238 230°C / 2.16 kg, and wherein the second polypropylene impact copolymer has a melt flow rate of 1 to 15 g / 10 min as measured according to ASTM D1238 230°C / 2.16 kg.

[0108] Embodiment 3. The polyolefin composition of embodiment 1 or 2, wherein in the first polypropylene impact copolymer and the second polypropylene impact copolymer, the homopolypropylene each independently has a tacticity index of 80% or more.

[0109] Embodiment 4. The polyolefin composition according to any one of embodiments 1-3, wherein in the first polypropylene impact copolymer and the second polypropylene impact copolymer, the α-olefin in the ethylene-α-olefin copolymer each independently has 2 to 8 carbon atoms.

[0110] Embodiment 5. The polyolefin composition according to any one of embodiments 1 to 4, wherein in the first polypropylene impact copolymer and the second polypropylene impact copolymer, the ethylene-α-olefin copolymer each independently comprises 10-75 wt% of ethylene-derived monomer units.

[0111] Embodiment 6. The polyolefin composition according to any one of embodiments 1-5, wherein in the first polypropylene impact copolymer and the second polypropylene impact copolymer, the ethylene-α-olefin copolymer each independently has an intrinsic viscosity of 1.5-8.5 dl / g.

[0112] Embodiment 7. The polyolefin composition according to any one of embodiments 1-6, wherein the first polypropylene impact copolymer has a flexural modulus of 1500 MPa to 2100 MPa, as determined according to ISO 178, and wherein the second polypropylene impact copolymer has a flexural modulus of 800 MPa to 1300 MPa, as determined according to ISO 178.

[0113] Embodiment 8. The polyolefin composition according to any one of embodiments 1-7, wherein the polyolefin elastomer has a melt flow rate of 1 to 15 g / 10 min as determined according to ASTM D1238 190°C / 2.16 kg.

[0114] Embodiment 9. The polyolefin composition of any one of embodiments 1-8, wherein the polyolefin elastomer has a glass transition temperature of -55°C to -50°C and a melting point of 40°C to 90°C.

[0115] Embodiment 10. The polyolefin composition according to any one of embodiments 1 to 9, wherein the polyolefin elastomer is an ethylene-α-olefin copolymer, preferably an ethylene-octene copolymer.

[0116] Embodiment 11. A polyolefin composition according to any one of Embodiments 1-10, wherein the filler comprises talc, calcium carbonate, calcium hydroxide, barium sulfate, mica, calcium silicate, clay, kaolin, silica, alumina, wollastonite, magnesium carbonate, magnesium hydroxide, titanium oxide, zinc oxide, zinc sulfate, or a combination thereof, preferably talc.

[0117] Embodiment 12. The polyolefin composition according to any one of embodiments 1-11,

[0118] wherein the polyolefin composition has a flexural modulus of 1550 MPa to 2200 MPa, measured according to ISO 178; and / or

[0119] The polyolefin composition has a thermal conductivity of 45-70 kJ / m 2 Izod notched impact strength; and / or

[0120] The polyolefin composition has a thermal conductivity of 50-80 kJ / m 2 Charpy notched impact strength of

[0121] wherein the polyolefin composition has a melt flow rate of 20 g / 10 min to 50 g / 10 min, measured according to ISO 1133; and / or

[0122] The polyolefin composition has a tensile strength measured according to ISO 527 of 15-40 MPa.

[0123] Embodiment 13. The polyolefin composition of any one of Embodiments 1-12, wherein the polypropylene impact copolymer comprises 60-95 wt% of the first polypropylene impact copolymer and 5-40 wt% of the second polypropylene impact copolymer, based on the total weight of the polypropylene impact copolymer.

[0124] Embodiment 14. A polyolefin composition comprising, based on the weight of the polyolefin composition:

[0125] A) 50 to 70 wt.% of a polypropylene impact copolymer, the polypropylene impact copolymer comprising a first polypropylene impact copolymer and a second polypropylene impact copolymer,

[0126] B) 15-30% by weight of a polyolefin elastomer, and

[0127] C) 10-25% by weight of fillers,

[0128] wherein the first polypropylene impact copolymer comprises 90-94 wt % of homopolypropylene and 6-10 wt % of ethylene-α-olefin copolymer, based on the weight of the first polypropylene impact copolymer,

[0129] wherein the second polypropylene impact copolymer comprises 78-88 wt% homopolypropylene and 12-22 wt% ethylene-α-olefin copolymer, based on the weight of the second polypropylene impact copolymer, and

[0130] The polypropylene impact copolymer comprises 60-95 wt % of a first polypropylene impact copolymer and 5-40 wt % of a second polypropylene impact copolymer, based on the total weight of the polypropylene impact copolymer.

[0131] Embodiment 15. An article made from the polyolefin composition according to any one of embodiments 1-14.

[0132] Embodiment 16. The article of embodiment 15, wherein the article is an automotive part, preferably an automotive bumper.

[0133] Embodiment 17. A method of making the article of embodiment 15 or 16, comprising melt extruding and injection molding the polyolefin composition according to any one of embodiments 1-14.

[0134] Example

[0135] The nature and purpose of the present invention will be further understood through the following examples. It should be understood that these examples are only for illustrative purposes and are not intended to limit the scope of the present invention.

[0136] Test Method

[0137] Flexural modulus (MPa) was measured according to ISO 178 standard method.

[0138] Izod notched impact strength (kJ / m 2 ) is measured according to ISO 180 / 1eA standard method.

[0139] Simple supported beam notched impact strength (kJ / m 2 ) is measured according to ISO 179 / 1eA standard method.

[0140] Tensile strength (MPa) was measured according to ISO 527 standard method.

[0141] Melt flow rate (MFR) is measured according to ISO 1133 standard method.

[0142] The coefficient of linear thermal expansion in the flow direction (CLTE) is measured according to the ASTM E831 standard method.

[0143] Multi-axial impact energy absorption peak (MAI ASTM) is measured according to ASTM D3763 multi-axial impact test standard method.

[0144] Shrinkage (%) was measured according to the ExxonMobil test method based on ISO 1133, which is described as follows: the size of the injection molded plate was 100 mm * 150 mm * 2.8 mm, the injection molding machine was a Demag experimental injection molding machine, the tonnage was 150 T, the injection temperature was 200 ° C, and the back pressure was 20 bar, 30 bar, 40 bar, 50 bar. Three different plates were tested at each back pressure, and the tests were conducted in the flow direction and perpendicular to the flow direction. The final result is the average of all test results.

[0145] Material

[0146] ExxonMobil TM PP7945E1 is a polypropylene impact copolymer available from ExxonMobil Chemical.

[0147] ExxonMobil TM PP7032E3 is a polypropylene impact copolymer available from ExxonMobil Chemical.

[0148] Engage 8200 is a polyolefin elastomer available from Dow.

[0149] HTP Ultra 5L is a talc powder purchased from Imifabi.

[0150] Table 1 Composition of the polyolefin composition in each embodiment

[0151] Example 1 Example 2 <![CDATA[ExxonMobil TM PP7945E1]]> 43 wt% 52% by weight <![CDATA[ExxonMobil TM PP7032E3]]> 12% by weight 10 wt% Engage 8200 26 wt% 22 wt% HTP Ultra 5L 19 wt% 16 wt% total 100% by weight 100% by weight

[0152] Example 1

[0153] The polyolefin composition of Example 1 of the present invention was formulated in a Leistriz twin-screw extruder with a screw diameter of 40 mm. Compounding was accomplished in the twin-screw extruder using mixing screw elements, with an extrusion process temperature of 210° C. and a die temperature of 230° C. The compound discharged from the extruder was pelletized. Table 2 shows the properties of the samples prepared from the polyolefin composition of Example 1 of the present invention.

[0154] Table 2 Performance of samples

[0155]

[0156] The data in Table 2 show that the various properties of the samples of the present invention meet the physical property standard of GMW15187, and in particular, the flexural modulus and impact strength thereof are higher than the physical property standard of GMW15187, indicating that the product of the present invention has high rigidity and high toughness. In addition, the polyolefin composition of the present invention has a higher melt flow rate and is more suitable for thin-wall injection molding design, thereby obtaining lightweight components, making it particularly suitable for lightweight applications, such as automobile bumpers.

[0157] Example 2

[0158] The polyolefin composition of Example 2 of the present invention was formulated in a Leistriz twin-screw extruder with a screw diameter of 40 mm. Compounding was accomplished in the twin-screw extruder using a mixing screw element, the extrusion process temperature was 210° C., and the die temperature was 230° C. The compound discharged from the extruder was pelletized. Table 3 shows the properties of the samples prepared from the polyolefin composition of Example 2 of the present invention.

[0159] Table 3 Performance of samples

[0160]

[0161] The data in Table 3 show that the various properties of the samples of the present invention meet the Nissan AS1 physical property standard, and in particular, the flexural modulus and impact strength thereof are much higher than the Nissan AS1 physical property standard, indicating that the product of the present invention has high rigidity and high toughness. In addition, the polyolefin composition of the present invention has a higher melt flow rate and is more suitable for thin-wall injection molding design, thereby obtaining lightweight components, making it particularly suitable for lightweight applications, such as automobile bumpers.

[0162] Although specific embodiments of the present invention are shown and described, it should be understood that other improvements, substitutions and alternatives are known to those skilled in the art. Such improvements, substitutions and alternative embodiments may be made without departing from the spirit and scope of the present invention which should be determined by the appended claims. Each feature of the present invention is described in the appended claims.

Claims

1. A polyolefin composition comprising, based on the weight of the polyolefin composition: A) 50 to 90 wt.% of a polypropylene impact copolymer, the polypropylene impact copolymer comprising a first polypropylene impact copolymer and a second polypropylene impact copolymer, B) 5 to 35% by weight of a polyolefin elastomer, and C) 5-30% by weight of fillers, wherein the first polypropylene impact copolymer comprises 90-94 wt % homopolypropylene and 6-10 wt % ethylene-α-olefin copolymer, based on the weight of the first polypropylene impact copolymer, and The second polypropylene impact copolymer comprises 78-88 wt % of homopolypropylene and 12-22 wt % of ethylene-α-olefin copolymer, based on the weight of the second polypropylene impact copolymer.

2. The polyolefin composition of claim 1, wherein the first polypropylene impact copolymer has a melt flow rate, measured according to ASTM D1238 230°C / 2.16kg, of 90 to 140 g / 10 min, and wherein the second polypropylene impact copolymer has a melt flow rate, measured according to ASTM D1238 230°C / 2.16kg, of 1 to 15 g / 10 min.

3. The polyolefin composition according to claim 1 or 2, wherein in the first polypropylene impact copolymer and the second polypropylene impact copolymer, the homopolypropylene each independently has a tacticity index of 80% or more.

4. The polyolefin composition according to any one of claims 1 to 3, wherein in the first polypropylene impact copolymer and the second polypropylene impact copolymer, the α-olefin in the ethylene-α-olefin copolymer each independently has 2 to 8 carbon atoms.

5. The polyolefin composition according to any one of claims 1 to 4, wherein in the first polypropylene impact copolymer and the second polypropylene impact copolymer, the ethylene-α-olefin copolymer each independently comprises 10 to 75 wt% of ethylene derived monomer units.

6. The polyolefin composition according to any one of claims 1 to 5, wherein in the first polypropylene impact copolymer and the second polypropylene impact copolymer, the ethylene-α-olefin copolymer each independently has an intrinsic viscosity of 1.5 to 8.5 dl / g.

7. The polyolefin composition according to any one of claims 1 to 6, wherein the first polypropylene impact copolymer has a flexural modulus determined according to ISO 178 of 1500 to 2100 MPa, and wherein the second polypropylene impact copolymer has a flexural modulus determined according to ISO 178 of 800 to 1300 MPa.

8. The polyolefin composition according to any one of claims 1 to 7, wherein the polyolefin elastomer has a melt flow rate of 1 to 15 g / 10 min, measured according to ASTM D1238 190°C / 2.16 kg.

9. The polyolefin composition according to any one of claims 1 to 8, wherein the polyolefin elastomer is an ethylene-α-olefin copolymer, preferably an ethylene-octene copolymer.

10. The polyolefin composition of any one of claims 1 to 9, wherein the polypropylene impact copolymer comprises 60 to 95 wt% of a first polypropylene impact copolymer and 5 to 40 wt% of a second polypropylene impact copolymer, based on the total weight of the polypropylene impact copolymer.

11. A polyolefin composition comprising, based on the weight of the polyolefin composition: A) 50 to 70 wt.% of a polypropylene impact copolymer, the polypropylene impact copolymer comprising a first polypropylene impact copolymer and a second polypropylene impact copolymer, B) 15-30% by weight of a polyolefin elastomer, and C) 10-25% by weight of fillers, wherein the first polypropylene impact copolymer comprises 90-94 wt % of homopolypropylene and 6-10 wt % of ethylene-α-olefin copolymer, based on the weight of the first polypropylene impact copolymer, wherein the second polypropylene impact copolymer comprises 78-88 wt% homopolypropylene and 12-22 wt% ethylene-α-olefin copolymer, based on the weight of the second polypropylene impact copolymer, and The polypropylene impact copolymer comprises 60-95 wt % of a first polypropylene impact copolymer and 5-40 wt % of a second polypropylene impact copolymer, based on the total weight of the polypropylene impact copolymer.

12. An article made from the polyolefin composition according to any one of claims 1 to 11.

13. A method for manufacturing the article of claim 12, comprising melt extruding and injection molding the polyolefin composition according to any one of claims 1 to 11.

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