Polypropylene-based resin composition, sheet molding, and container

Abstract

The present invention provides a polypropylene-based resin composition comprising a polypropylene-based resin (A), an ethylene / α-olefin copolymer (B), and an inorganic filler (C) as an optional component. The polypropylene-based resin (A) comprises a continuous phase consisting of a propylene polymer (a1) and a rubber phase consisting of a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms (a2). The ethylene / α-olefin copolymer (B) is a polymer of ethylene and an α-olefin having 2 to 10 carbon atoms. The polypropylene-based resin composition has an MFR of 0.1 g / 10 min to 3.0 g / 10 min at a temperature of 230°C and a load of 2.16 kg.

Description

Technical Field

[0001] This invention relates to a polypropylene-based resin composition, sheet moldings, and containers. This application claims priority to Japanese Patent Application No. 2021-105708, filed on June 25, 2021, the contents of which are incorporated herein by reference. Background Technology

[0002] Polypropylene is used for a variety of purposes because of its excellent physical properties, such as impact resistance, rigidity, transparency, chemical resistance and heat resistance.

[0003] For example, Patent Document 1 discloses a polypropylene-based resin composition suitable for obtaining injection-molded articles with an excellent balance of rigidity and impact resistance as well as a good appearance.

[0004] Existing technical documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-189818. Summary of the Invention

[0006] The problem to be solved by the present invention

[0007] When obtaining sheet molded articles from polypropylene-based resin compositions, the polypropylene-based resin compositions are required to have high stretch resistance, good sheet moldability, and good sheet productivity.

[0008] On the other hand, containers (e.g., cups, plates, trays, bottles, etc.) further formed from sheet moldings as component materials are required to possess mechanical properties such as rigidity and impact resistance. For example, ice cream containers are required to have excellent impact resistance at extremely low temperatures of approximately -40°C. This is a physical property that is at a different level from impact resistance at around -5°C, and conventional polypropylene-based resin compositions are quite difficult to meet this requirement.

[0009] The present invention provides sheet molded articles and containers with excellent impact resistance at extremely low temperatures of -40°C, as well as polypropylene-based resin compositions that can be formed into sheet molded articles.

[0010] Problems to be solved

[0011] The present invention has the following aspects.

[0012] [1] A polypropylene-based resin composition comprising:

[0013] A polypropylene-based resin (A) comprising a continuous phase composed of a propylene polymer (a1) and a rubber phase composed of a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms (a2), and

[0014] Ethylene / α-olefin polymer (B), wherein the ethylene / α-olefin polymer (B) is a polymer of ethylene and an α-olefin having 2 to 10 carbon atoms.

[0015] Inorganic filler (C) as an optional component,

[0016] The MFR of the polypropylene-based resin composition at 230°C and a load of 2.16 kg was 0.1 g / 10 min to 3.0 g / 10 min.

[0017] The total weight of (A), (B), and (C) relative to the total weight of the polypropylene-based resin composition is 70% by weight or greater.

[0018] The total weight of (A) and (B) is 50% by weight or greater relative to the total weight of the polypropylene-based resin composition.

[0019] Relative to a total of 100 parts by weight of (A) and (B), (A) comprises 99 parts by weight or less, (B) comprises 1 part by weight or more, and (C) comprises 0 to 60 parts by weight.

[0020] The content of ethylene-derived units in propylene polymer (a1) is 0.5% by weight or less relative to the total weight of propylene polymer (a1).

[0021] The copolymer (a2) content is 27% to 45% by weight relative to the total weight of the polypropylene-based resin (A).

[0022] The content of ethylene-derived units in copolymer (a2) is 25% to 85% by weight relative to the total weight of copolymer (a2).

[0023] The xylene-soluble fraction of polypropylene-based resin (A) has an intrinsic viscosity of 2.5 dl / g to 5.5 dl / g in tetrahydronaphthalene at 135 °C.

[0024] [2] According to the polypropylene-based resin composition of [1], wherein the crystallization peak observed between 85°C and 105°C in the DSC measurement of the polypropylene-based resin (A) has a calorific value of 0.5 J / g to 10 J / g.

[0025] [3] The polypropylene-based resin composition according to [1] or [2], wherein the propylene polymer (a1) has an average pore size of 8 μm to 50 μm.

[0026] [4] A sheet molded article formed from a polypropylene-based resin composition according to any one of [1] to [3].

[0027] [5] The sheet molded article according to [4] is used to form a container.

[0028] [6] A container formed from a sheet molded article according to [4] or [5].

[0029] Effects of the present invention

[0030] By using the polypropylene-based resin composition of the present invention, sheet molded articles exhibiting excellent impact resistance at extremely low temperatures of about -40°C can be obtained. Containers formed from this polypropylene-based resin composition, or sheet molded articles as component materials, can exhibit excellent impact resistance at extremely low temperatures of -40°C.

[0031] In addition to its use as a container, it can be used in applications including, for example, groceries, daily necessities, household appliance parts, electrical and electronic parts, automotive parts, housing parts, toy parts, furniture parts, building material parts, packaging parts, industrial materials, logistics materials, agricultural materials, etc. (including its use in the form of plastic cardboard). Attached Figure Description

[0032] Figure 1 This is a perspective view of a sheet molded article according to an example of the present invention.

[0033] Figure 2 This is a perspective view of a container according to an example of the present invention.

[0034] Figure 3 This is an example of a DSC chart taken from a sample of polypropylene-based resin granules produced in the example. Detailed Implementation

[0035] <Polypropylene-based resin composition>

[0036] The polypropylene-based resin composition of the present invention comprises a polypropylene-based resin (A) (hereinafter also referred to as component (A)), which comprises a continuous phase composed of a propylene polymer (hereinafter also referred to as component (a1)) and a rubber phase composed of a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms (hereinafter also referred to as component (a2)), and an ethylene / α-olefin polymer (B) (hereinafter also referred to as component (B)), which is a polymer of ethylene and an α-olefin having 2 to 10 carbon atoms.

[0037] In addition, as an optional component, it may include or exclude inorganic filler (C) (hereinafter also referred to as component (C)).

[0038] The total weight of components (A), (B), and (C) relative to the total weight of the polypropylene-based resin composition is 70% by weight or more, with a lower limit preferably 80% by weight or more, more preferably 90% by weight or more, and even more preferably 95% by weight or more. The upper limit is preferably less than 100% by weight.

[0039] When the material is at or above the lower limit of the above range, the impact resistance of the sheet molded articles of the present invention increases at extremely low temperatures. If it is below the upper limit of the above range, there is room for the inclusion of other components such as antioxidants or neutralizers.

[0040] The total weight of components (A) and (B) relative to the total weight of the polypropylene-based resin composition is 50% by weight or more, with a lower limit preferably 60% by weight or more, more preferably 70% by weight or more, even more preferably 80% by weight or more, and particularly preferably 95% by weight or more. The upper limit is preferably less than 100% by weight.

[0041] If the material is at or above the lower limit of the above range, the impact resistance of the sheet molded article of the present invention increases at extremely low temperatures. If the material is below the upper limit of the above range, there is room for the inclusion of other components such as antioxidants or neutralizers.

[0042] Relative to a total of 100 parts by weight of components (A) and (B), the content of component (A) is 99 parts by weight or less, and the upper limit is preferably 70 parts by weight or more, more preferably 80 parts by weight or more. The upper limit is preferably 95 parts by weight or less, more preferably 90 parts by weight or less. That is, examples include the following ranges: 70 to 99 parts by weight, 70 to 95 parts by weight, 70 to 90 parts by weight, 80 to 99 parts by weight, 80 to 95 parts by weight, and 80 to 90 parts by weight.

[0043] When the content is at or above the lower limit of the above range, the rigidity of the sheet molded article increases. When the content is at or below the upper limit of the above range, the content of component (B) will be relatively high, and the impact resistance of the sheet molded article of the present invention will increase at extremely low temperatures.

[0044] Relative to a total of 100 parts by weight of components (A) and (B), the content of component (B) is 1 part by weight or more, and the upper limit is preferably 5 parts by weight or more, more preferably 10 parts by weight or more. The upper limit is preferably 30 parts by weight or less, more preferably 20 parts by weight or less. That is, examples include the following ranges: 1 part by weight to 30 parts by weight, 1 part by weight to 20 parts by weight, 5 parts by weight to 30 parts by weight, 5 parts by weight to 20 parts by weight, 10 parts by weight to 30 parts by weight, and 10 parts by weight to 20 parts by weight.

[0045] When the temperature is at or above the lower limit of the above range, the impact resistance of sheet molded products increases at extremely low temperatures.

[0046] When it is at or below the upper limit of the above range, the content of component (A) will be relatively high, and the rigidity of the sheet molded article of the present invention will increase.

[0047] The content of component (C) is 0 to 60 parts by weight relative to the total amount of components (A) and (B) of 100 parts by weight, and the upper limit is preferably 40 parts by weight or less, and more preferably 30 parts by weight or less.

[0048] When it is at or below the upper limit of the above range, it becomes easy to mold sheet articles and containers from the polypropylene-based resin composition of the present invention. Figure 1 and Figure 2 A sheet molded article 10 and a cup-shaped container 20 formed from the sheet molded article are shown as examples of the present invention.

[0049] Furthermore, by including component (C), the rigidity (stiffness) of the sheet molded article is increased.

[0050] The MFR of the polypropylene-based resin composition at a temperature of 230°C and a load of 2.16 kg is from 0.1 g / 10 min to 3.0 g / 10 min, with the lower limit preferably being 0.2 g / 10 min or greater, and more preferably 0.3 g / 10 min or greater. Furthermore, the upper limit is preferably 2.5 g / 10 min or less, more preferably 1.8 g / 10 min or less, and even more preferably 1.0 g / 10 min or less. In other words, examples include the following ranges: 0.1g / 10min to 2.5g / 10min, 0.1g / 10min to 1.8g / 10min, 0.1g / 10min to 1.0g / 10min, 0.2g / 10min to 3.0g / 10min, 0.2g / 10min to 2.5g / 10min, 0.2g / 10min to 1.8g / 10min, 0.2g / 10min to 1.0g / 10min, 0.3g / 10min to 3.0g / 10min, 0.3g / 10min to 2.5g / 10min, 0.3g / 10min to 1.8g / 10min, and 0.3g / 10min to 1.0g / 10min. Here, MFR is a value measured by the measurement method described below.

[0051] When it is at or above the lower limit of the above range, the sheet exhibits excellent moldability. However, manufacturing is typically difficult by adjusting it to less than 0.1 g / 10 minutes.

[0052] When it is at or below the upper limit of the above range, sheet moldability (stretch resistance) and sheet productivity are improved, and the impact resistance of sheet molded products increases at extremely low temperatures.

[0053] [Polypropylene-based resin (A)]

[0054] The polypropylene-based resin (A) included in the polypropylene-based resin composition of the present invention is an example of an impact-resistant polypropylene polymer as specified in JIS K6921-1, and is composed of two or more phases, which include a continuous phase of a propylene polymer present as a dispersed phase in the continuous phase (component (a1)) and a rubber phase of an ethylene / α-olefin copolymer (component (a2)).

[0055] The polypropylene-based resin (A) can be a mixed resin in which components (a1) and (a2) are mixed during polymerization, or a mixed resin in which separately obtained components (a1) and (a2) are mixed by melt kneading. It is preferred to mix components (a1) and (a2) (polymerization mixture) during polymerization because an excellent balance between rigidity, low-temperature impact resistance and tensile properties (hereinafter also referred to as "mechanical-physical property balance") is obtained at a lower cost.

[0056] In the polymerization mixture, components (a1) and (a2) can be mixed with each other at the submicron level, and the polypropylene-based resin composition based on the polymerization mixture exhibits an excellent balance of mechanical and physical properties.

[0057] On the other hand, if a simple mechanical mixture obtained separately by melting and kneading components (a1) and (a2) is used to achieve similar homogeneous mixing and a good balance of mechanical and physical properties, the manufacturing cost increases due to the need for separate processes such as storage, transportation, measurement, mixing, melting, and kneading. This is also disadvantageous from an energy cost perspective.

[0058] The reason why polymeric mixtures and mechanical mixtures can exhibit different physical properties is believed to be due to the difference in the dispersion state of component (a2) within component (a1). Currently, there are no known practical means to analyze the dispersion state of component (a2) at the molecular level, including the interfacial state with component (a1). The method for producing polypropylene-based resin (A) will be explained in detail later.

[0059] The intrinsic viscosity (hereinafter also referred to as "XSIV") of the xylene-soluble portion of the polypropylene-based resin (A) is from 2.5 dl / g to 5.5 dl / g, with the lower limit preferably being 2.7 dl / g or greater. Furthermore, the upper limit is preferably 4.5 dl / g or less, more preferably 4.0 dl / g or less, and even more preferably 3.5 dl / g or less. That is, examples include the following ranges: 2.5 dl / g to 4.5 dl / g, 2.5 dl / g to 4.0 dl / g, 2.5 dl / g to 3.5 dl / g, 2.7 dl / g to 5.5 dl / g, 2.7 dl / g to 4.5 dl / g, 2.7 dl / g to 4.0 dl / g, and 2.7 dl / g to 3.5 dl / g. Here, XSIV is a value measured by the method described later.

[0060] When the temperature is at or above the lower limit of the above range, the impact resistance of sheet molded products increases at extremely low temperatures.

[0061] When it is at or below the upper limit of the above range, the productivity of polypropylene-based resin (A) increases. In addition, the moldability of the sheet is improved, and the impact resistance of the sheet molded articles is increased at extremely low temperatures.

[0062] The weight-average molecular weight M is an index of the molecular weight distribution of the propylene polymer (component (a1)) that constitutes the polypropylene-based resin (A). w Number-average molecular weight M n The ratio (M) w / M n The value is preferably 9 or less, more preferably 8 or less, and even more preferably less than 7. When it is within the above preferred range, the impact resistance of the sheet molding increases at extremely low temperatures.

[0063] There is no particular limitation on the lower limit of the above ratio, and, for example, 3 or greater can be mentioned as a guideline.

[0064] Here, the weight-average molecular weight M of the propylene polymer is... w Number-average molecular weight M n The value is measured using the following method.

[0065] The content of ethylene-derived units (hereinafter also referred to as "C2") in the propylene polymer (component (a1)) constituting the polypropylene-based resin (A) is 0.5% by weight or less, preferably 0.3% by weight or less, relative to the total weight of the propylene polymer.

[0066] When C2 is at or below the upper limit, the rigidity of the sheet molded product increases.

[0067] There is no particular restriction on the lower limit of C2, and it can be 0% by weight.

[0068] In other words, the propylene polymer can be a polypropylene homopolymer consisting solely of propylene-derived units, or a copolymer consisting of propylene-derived units in an amount between 99.5% by weight and less than 100% by weight, and ethylene-derived units in an amount between 0% by weight and less than 0.5% by weight. C2 via 13 Measured using C-NMR method.

[0069] The average pore size (Dn) of component (a1) is preferably from 8 μm to 50 μm, more preferably from 8 μm to 30 μm, and even more preferably from 8 μm to 15 μm.

[0070] Dn is the average value of the pore size D measured by mercury intrusion porosimetry according to JIS R1655. When Dn is within this range, the powder flowability of the polypropylene-based resin (A) composed of component (a1) and component (a2) is improved, and consequently, productivity is increased. Although the mechanism is unclear, it is speculated that when the Dn of component (a1) is within the above-mentioned range, since component (a2) is present in component (a1), the pore size and total pore surface area are sufficient, and as a result, component (a2) is easily retained in component (a1), thereby improving the powder flowability of the polymer.

[0071] The ethylene / α-olefin copolymer (component (a2)) constituting the polypropylene-based resin (A) is a copolymer having ethylene-derived units and α-olefin-derived units having 3 to 10 carbon atoms.

[0072] The content of ethylene-derived units in component (a2) is from 25% to 85% by weight relative to the total weight of component (a2), with a lower limit preferably of 29% by weight or more, more preferably 40% by weight or more, and even more preferably 45% by weight or more. Furthermore, the upper limit is preferably 70% by weight or less, more preferably 60% by weight or less, and even more preferably 55% by weight or less. That is, examples include the following ranges: 25% to 70% by weight, 25% to 60% by weight, 25% to 55% by weight, 29% to 85% by weight, 29% to 70% by weight, 29% to 60% by weight, 29% to 55% by weight, 40% to 85% by weight, 40% to 70% by weight, 40% to 60% by weight, 40% to 55% by weight, 45% to 85% by weight, 45% to 70% by weight, 45% to 60% by weight, and 45% to 55% by weight.

[0073] When the temperature is at or above the lower limit of the above range, the impact resistance of sheet molded products increases at extremely low temperatures.

[0074] When it is at or below the upper limit of the above range, the risk of clogging the flow path on the production equipment due to the deterioration of powder flowability during the production of polypropylene-based resin (A) can be reduced, so that polypropylene-based resin (A) can be produced stably and continuously.

[0075] The content of ethylene-derived units in component (a2) is determined by... 13 Measured using C-NMR method.

[0076] The content of the ethylene / α-olefin copolymer (component (a2)) relative to the total weight of the polypropylene-based resin (A) is from 27% to 45% by weight, with a lower limit preferably of 29% by weight or more, and more preferably 32% by weight or more. Furthermore, the upper limit is preferably 42% by weight or less, more preferably 38% by weight or less. That is, examples include the following ranges: 27% to 42% by weight, 27% to 38% by weight, 29% to 45% by weight, 29% to 42% by weight, 29% to 38% by weight, 32% to 45% by weight, 32% to 42% by weight, and 32% to 38% by weight.

[0077] When the temperature is at or above the lower limit of the above range, the impact resistance of sheet molded products increases at extremely low temperatures.

[0078] When it is at or below the upper limit of the above range, the risk of clogging the flow path on the production equipment due to the deterioration of powder flowability during the production of polypropylene-based resin (A) can be reduced, so that polypropylene-based resin (A) can be produced stably and continuously.

[0079] Furthermore, depending on the content of component (a2), the content of component (a1) relative to the total weight of polypropylene-based resin (A) is preferably 55% to 73% by weight. Within this suitable range, the lower limit is preferably 58% by weight or more, more preferably 62% by weight or more, and the upper limit is preferably 71% by weight or less, more preferably 68% by weight or less. That is, examples include the following ranges: 55% to 71% by weight, 55% to 68% by weight, 58% to 73% by weight, 58% to 71% by weight, 58% to 68% by weight, 62% to 73% by weight, 62% to 71% by weight, and 62% to 68% by weight.

[0080] Examples of α-olefins constituting ethylene / α-olefin copolymers (component (a2)) include propylene (1-propylene), 1-butene, 1-pentene, 1-hexene, and 1-octene.

[0081] Specific examples of component (a2) include ethylene / propylene copolymers, ethylene / butene copolymers, ethylene / pentene copolymers, ethylene / hexene copolymers, ethylene / octene copolymers, etc.

[0082] Among them, considering the improvement of the productivity of polypropylene-based resin (A), ethylene / propylene copolymer is preferred.

[0083] The MFR of polypropylene-based resin (A) at a temperature of 230°C and a load of 2.16 kg, i.e., the MFR of component (a1) + component (a2), is preferably 0.1 g / 10 min or greater as the lower limit, more preferably 0.2 g / 10 min or greater, and even more preferably 0.3 g / 10 min or greater. Furthermore, the upper limit is preferably 2.5 g / 10 min or less, more preferably 1.8 g / 10 min or less, and even more preferably 1.0 g / 10 min or less. In other words, examples include the following ranges: 0.1g / 10min to 2.5g / 10min, 0.1g / 10min to 1.8g / 10min, 0.1g / 10min to 1.0g / 10min, 2.0g / 10min to 2.5g / 10min, 0.2g / 10min to 1.8g / 10min, 0.2g / 10min to 1.0g / 10min, 0.3g / 10min to 2.5g / 10min, 0.3g / 10min to 1.8g / 10min, and 0.3g / 10min to 1.0g / 10min. Here, MFR is a value measured by the measurement method described later.

[0084] When it is at or above the lower limit of the above range, the sheet exhibits excellent moldability. However, manufacturing is typically difficult by adjusting it to less than 0.1 g / 10 minutes.

[0085] When it is at or below the upper limit of the above range, sheet moldability (stretch resistance) and sheet productivity are improved, and the impact resistance of sheet molded products increases at extremely low temperatures.

[0086] In the DSC (Differential Scanning Calorimetry) of the polypropylene-based resin (A), a crystallization peak is preferably observed between 85°C and 105°C. This crystallization peak originates from the crystallization of the polyethylene component (component (a2)) of the ethylene / α-olefin copolymer constituting the polypropylene-based resin (A). As described below, generally, when the ethylene / α-olefin copolymer is polymerized using a Ziegler-Natta catalyst, components with different contents of ethylene-derived units are produced (a so-called compositional distribution), and therefore, when the content of ethylene-derived units in component (a2) exceeds a certain level, a long ethylene chain component (polyethylene component) that can crystallize is generated. The polyethylene component is particularly effective for impact resistance at low temperatures, and the impact resistance at extremely low temperatures of the present invention is further improved when component (a2) constituting the polypropylene-based resin (A) contains the polyethylene component. Therefore, even if the amount of ethylene / α-olefin polymer (B) added to the polypropylene-based resin (A) is small, sufficient impact resistance at extremely low temperatures can be achieved.

[0087] In DSC, the calorific value (ΔHc) of the crystallization peak observed between 85°C and 105°C is an index of the amount of polyethylene component contained in the polypropylene-based resin (A), and depends on the content of component (a2) in the polypropylene-based resin (A). Besides the content of ethylene-derived units in component (a2), it also depends on the catalyst and polymerization conditions during the production of the polypropylene-based resin (A).

[0088] When DSC is performed on polypropylene-based resin (A) by the method described below, from the viewpoint of improving impact resistance at extremely low temperatures, the lower limit of ΔHc observed between 85°C and 105°C is preferably 0.5 J / g or greater, and more preferably 1.0 J / g or greater. On the other hand, when ΔHc is 10 J / g or less, rigidity is maintained, and the affinity between component (a1) and component (a2) is maintained, and therefore the balance between rigidity and impact resistance becomes better. The more preferred upper limit of ΔHc is 8.0 J / g or less. That is, examples include the following ranges: 0.5 J / g to 10 J / g, 0.5 J / g to 8.0 J / g, 1.0 J / g to 10 J / g, and 1.0 J / g to 8.0 J / g.

[0089] [Ethylene / α-olefin copolymer (B)]

[0090] Ethylene / α-olefin copolymer (B) is a copolymer of ethylene and an α-olefin having 2 to 10 carbon atoms. Examples of α-olefins include ethylene, propylene (1-propylene), 1-butene, 1-pentene, 1-hexene, and 1-octene.

[0091] Specific examples of ethylene / α-olefin copolymers (B) include polyethylene, ethylene / butene copolymers, ethylene / pentene copolymers, ethylene / hexene copolymers, ethylene / octene copolymers, etc.

[0092] From the viewpoint of increasing the impact resistance of sheet molded products at extremely low temperatures, polyethylene is preferred. For polyethylene, high-density polyethylene (HDPE) is preferred. The density of HDPE is measured according to JIS K6922-1:2018 at 23℃±2℃, and is preferably greater than 940 kg / m³. 3 And preferably greater than 954 kg / m 3 Regarding the upper limit of HDPE density, 990 kg / m³ can be mentioned. 3 As guidance.

[0093] [Inorganic packing (C)]

[0094] Examples of inorganic fillers (C) include natural silicates or silicates such as talc, kaolinite, clay, pyrophyllite, selenite, wollastonite, and mica; synthetic silicates or silicates such as hydrated calcium silicate, hydrated aluminum silicate, hydrated silicate, and anhydrous silicate; carbonates such as precipitated calcium carbonate, heavy calcium carbonate, and magnesium carbonate; hydroxides such as aluminum hydroxide and magnesium hydroxide; and oxides such as zinc oxide and magnesium oxide.

[0095] Furthermore, from a shape perspective, examples of inorganic packing materials include the following:

[0096] Powdered fillers, such as synthetic silicates or silicates, such as hydrated calcium silicate, hydrated aluminum silicate, hydrated silicate and anhydrous silicate; plate-shaped fillers, such as talc, kaolinite, clay and mica; whisker-shaped fillers, such as basic magnesium sulfate whiskers, calcium titanate whiskers, aluminum borate whiskers, sepiolite, PMF (treated mineral filler), calcareous silicate, potassium titanate and elastadite; air-filled fillers, such as glass air-fillers, fly ash air-fillers; fiber fillers, such as glass fiber.

[0097] One type of inorganic filler can be used, or two or more types of inorganic fillers can be used in combination. To improve the dispersibility of these fillers, surface treatment may be performed if necessary. Although the inorganic fillers used in this invention are not limited, plate-shaped inorganic fillers are preferred from the viewpoint of improving the balance of mechanical properties by promoting the orientation of polypropylene crystals in sheet molded articles.

[0098] As plate-shaped inorganic fillers, known materials such as talc, kaolinite, clay, and mica can be used. Considering their affinity with polypropylene-based resins, ease of sourcing as raw materials, and economic benefits, talc and mica are preferred, with talc being more preferred.

[0099] The volume average particle size of the inorganic filler (C) is preferably from 1 μm to 10 μm, more preferably from 2 μm to 7 μm. If the volume average particle size is within the above range, the mechanical property balance of the sheet molded article will be very high. The volume average particle size can be measured as the 50% diameter by laser diffraction (based on JIS R1629) as a volume-based integral fraction.

[0100] [Other components]

[0101] The polypropylene-based resin composition of the present invention may include synthetic resins or synthetic rubbers other than polypropylene-based resin (A) and ethylene / α-olefin copolymer (B), and inorganic fillers (C) other than polypropylene-based resin (A), ethylene / α-olefin copolymer (B), and additives as optional components, within the scope of not affecting the effects of the present invention.

[0102] Examples of additives include, for example, antioxidants, neutralizers, nucleating agents, weathering agents, pigments (organic or inorganic), internal and external lubricants, anti-blocking agents, antistatic agents, chlorine absorbers, heat stabilizers, light stabilizers, UV absorbers, slip agents, antifogging agents, flame retardants, dispersants, copper damage inhibitors, plasticizers, foaming agents, defoamers, crosslinking agents, peroxides, oil bulking agents, etc. These additives can be used alone or in combination of two or more types. The content can be a known amount.

[0103] <Production Method of Polypropylene Resin Composition>

[0104] Examples of methods for producing the polypropylene-based resin compositions of the present invention include a method in which a polypropylene-based resin (A) and an ethylene / α-olefin copolymer (B) and an inorganic filler component (C) are mixed and then melt-kneaded.

[0105] Examples of mixing methods include dry mixing using mixers such as Henschel mixers, flippers, and ribbon mixers.

[0106] Examples of melt kneading methods include mixing using methods such as single-screw extruders, twin-screw extruders, Banbury mixers, kneaders, and roller mills during melting. The melt temperature during melt kneading is preferably from 160°C to 350°C, more preferably from 170°C to 260°C. Further granulation can be performed after melt kneading.

[0107] When blending component (C), component (C) can be dry-mixed into granules containing at least one of components (A) and (B). The dry-mixed component (C) is then uniformly mixed with components (A) and (B) that are molten during molding of the polypropylene-based resin composition. Alternatively, in this invention, a so-called masterbatch prepared by melt-kneading a high concentration of component (C) with a resin component can be added to at least one of components (A) and (B) and melt-kneaded, or it can be dry-mixed with granules containing at least one of components (A) and (B). In this case, the ratio of the resin component in the masterbatch and the amount of masterbatch added are adjusted so that the resin component in the masterbatch does not affect the physical properties of the polypropylene-based resin composition.

[0108] Relative to the total weight of the polypropylene-based resin composition of this embodiment, the content of resin components in the masterbatch is preferably 30% by weight or less, more preferably 25% by weight or less, and even more preferably 20% by weight or less. Within the above preferred range, adverse effects on the physical properties of the polypropylene-based resin composition caused by the resin components contained in the masterbatch can be prevented. Although the type of resin component is not limited, olefin-based resins are preferred considering the affinity of olefin-based resins for the polypropylene-based resins and ethylene / α-olefin copolymers constituting the composition.

[0109] The content of the masterbatch is preferably 100 parts by weight or less, more preferably 70 parts by weight or less, and even more preferably 50 parts by weight or less, relative to the total amount of 100 parts by weight of components (A) and (B). Within the above preferred range, the rigidity of the sheet can be increased without compromising the moldability of the sheet or the impact resistance of the sheet at extremely low temperatures.

[0110] [Production method of polypropylene-based resin (A)]

[0111] The polypropylene-based resin (A) is obtained by mixing a propylene polymer (component (a1)) and an ethylene / α-olefin copolymer (component (a2)) during polymerization. Alternatively, components (a1) and (a2) produced separately can be mixed by melt kneading.

[0112] Preferred polypropylene-based resin (A) is a polymerization mixture in which components (a1) and (a2) are mixed during polymerization.

[0113] This polymerization mixture is obtained by polymerizing ethylene monomers and α-olefin monomers in the presence of component (a1). According to this method, productivity is increased, and the dispersibility of component (a2) in component (a1) is improved, thereby enhancing the balance of mechanical and physical properties of the sheet molded articles obtained using this method.

[0114] The following text describes the use of propylene monomers as α-olefin monomers, which can also be used in production when other α-olefin monomers are used.

[0115] Multi-stage polymerization is commonly used as a method for producing polymeric blends. For example, a polymeric blend can be obtained as follows: propylene monomer and (if necessary) ethylene monomer are polymerized in a first-stage polymerization reactor of a polymerization apparatus equipped with a two-stage polymerization reactor to obtain a propylene polymer, and the resulting polypropylene polymer is supplied to a second-stage polymerization reactor, where ethylene monomer and propylene monomer are polymerized.

[0116] Polymerization conditions can be similar to known polymerization conditions. For example, first-stage polymerization conditions include slurry polymerization, where propylene is in the liquid phase and monomer density and yield are high. As second-stage polymerization conditions, gas-phase polymerization methods that typically allow for the easy production of copolymers with high solubility in propylene can be mentioned.

[0117] The polymerization temperature is preferably 50°C to 90°C, more preferably 60°C to 90°C, and even more preferably 70°C to 90°C. When the polymerization temperature is at or above the lower limit of the above range, the yield and stereoregularity of the polypropylene are better.

[0118] When carried out in the liquid phase, the polymerization pressure is preferably 25 to 60 bar (2.5 MPa to 6.0 MPa), more preferably 33 to 45 bar (3.3 MPa to 4.5 MPa). When carried out in the gas phase, the pressure is preferably 5 to 30 bar (0.5 MPa to 3.0 MPa), more preferably 8 to 30 bar (0.8 MPa to 3.0 MPa).

[0119] Polymerization (polymerization of propylene monomers, polymerization of ethylene monomers, etc.) is typically carried out using a catalyst. During polymerization, hydrogen may be added if necessary to adjust the molecular weight. By adjusting the molecular weight of the propylene polymer or ethylene / propylene copolymer, the molecular weight ratio (MFR) of the polypropylene-based resin (A) can be adjusted, and thus the MFR of the polypropylene-based resin composition can be adjusted.

[0120] Prior to polymerization in the first-stage polymerization reactor, propylene can be prepolymerized to form polymer chains in the solid catalyst component, which will serve as the base for subsequent main polymerization. Prepolymerization is typically carried out at a temperature of 40°C or lower, preferably 30°C or lower, and more preferably 20°C or lower.

[0121] Known olefin polymerization catalysts can be used as catalysts.

[0122] Stereoselective Ziegler-Natta catalysts are preferred as catalysts for polymerizing ethylene monomers and propylene monomers in the presence of propylene polymers, and catalysts comprising components (a), (b) and (c) (hereinafter also referred to as “catalyst (X)”) are particularly preferred.

[0123] (a) A solid catalyst as an essential component, the solid catalyst containing magnesium, titanium, halogen and phthalate-based compounds as electron donor compounds.

[0124] (b) Organoaluminum compounds.

[0125] (c) Organosilicon compounds that act as external electron donors.

[0126] Preferably, the polypropylene-based resin (A) is produced in a method comprising the step of polymerizing ethylene monomers and α-olefin monomers (e.g., propylene monomers) in the presence of a propylene polymer using a catalyst (X) to obtain a polypropylene-based resin. By using the catalyst (X), polypropylene-based resin (A) with physical properties within the aforementioned ranges can be readily obtained.

[0127] It is important to note that the molecular weight and stereoregularity distributions of the resulting propylene polymers vary depending on the catalyst used (particularly for the electron-donating compound in (a)), and these differences affect crystallization behavior, but the detailed relationships between them are not revealed. To clarify this, it would be necessary to analyze both the molecular weight and stereoregularity distributions as molecular structures, but this is complex because components with different molecular weights and stereoregularities interact during crystallization, making it even more difficult to interpret the effects of molecular weight and stereoregularity distributions on crystallization behavior. Furthermore, since actual sheet molding occurs in the fluidized state of molten resin, this phenomenon is not easily understood even with advanced analytical techniques. Therefore, in polypropylene-based resin compositions obtained using specific catalysts, it is almost impossible to numerically or otherwise definitively indicate differences in crystallization behavior due to molecular weight or stereoregularity. Molecular weight and stereoregularity distributions are altered not only by the type of catalyst mentioned above but also by thermal degradation during melting and kneading, peroxide treatment, etc.

[0128] Component (a) is prepared using, for example, titanium compounds, magnesium compounds and electron donor compounds.

[0129] The titanium compound used as component (a) is a tetravalent titanium compound represented by the following general formula: Ti(OR) g X 4-g (R is a hydrocarbon group, X is a halogen, 0≤g≤4) is appropriate.

[0130] Examples of hydrocarbon groups include methyl, ethyl, propyl, butyl, etc., and examples of halogens include Cl, Br, etc.

[0131] More specific titanium compounds include titanium tetrahalides, such as TiCl4, TiBr4, and TiI4; and titanium trihaloalkoxy compounds, such as Ti(OCH3)Cl3, Ti(OC2H5)Cl3, and Ti(O n -C4H9)Cl3, Ti(OC2H5)Br3, Ti(O-isoC4H9)Br3; dihaloalkoxytitanium, such as Ti(OCH3)2Cl2, Ti(OC2H5)2Cl2, Ti(O-isoC4H9)Br3; dihaloalkoxytitanium, such as Ti(OCH3)2Cl2, Ti(OC2H5)2Cl2, Ti(O n-C4H9)2Cl2, Ti(OC2H5)2Br2; monohalogenated trialkoxy titanium, such as Ti(OCH3)3Cl, Ti(OC2H5)3Cl, Ti(O n -C4H9)3Cl, Ti(OC2H5)3Br; tetraalkoxytitanium, such as Ti(OCH3)4, Ti(OC2H5)4, Ti(O n -C4H9)4. These titanium compounds can be used alone or in combination of two or more types.

[0132] Among the above-mentioned titanium compounds, halogen-containing titanium compounds are preferred, titanium tetrahalides are more preferred, and titanium tetrachloride (TiCl4) is particularly preferred.

[0133] Magnesium compounds used in component (a) include those having magnesium-carbon or magnesium-hydrogen bonds, such as dimethylmagnesium, diethylmagnesium, dipropylmagnesium, dibutylmagnesium, dipentylmagnesium, dihexylmagnesium, didecylmagnesium, ethyl magnesium chloride, propyl magnesium chloride, butyl magnesium chloride, hexyl magnesium chloride, pentyl magnesium chloride, butylethoxymagnesium, ethylbutylmagnesium, butyl hydride, etc. These magnesium compounds may also be used in the form of complexes with, for example, organoaluminum compounds, and may be in liquid or solid form. Other suitable magnesium compounds include magnesium halides such as magnesium chloride, magnesium bromide, magnesium iodide, and magnesium fluoride; alkoxy magnesium halides such as methoxy magnesium chloride, ethoxy magnesium chloride, isopropoxy magnesium chloride, butoxy magnesium chloride, and octoxy magnesium chloride; allyloxy magnesium halides such as phenoxy magnesium chloride and methylphenoxy magnesium chloride; alkoxy magnesium compounds such as ethoxy magnesium, isopropoxy magnesium, butoxy magnesium, n-octoxy magnesium, and 2-ethylhexyloxy magnesium; dialkoxy magnesium compounds such as dimethoxy magnesium, diethoxy magnesium, dipropoxy magnesium, dibutoxy magnesium, and ethoxymethoxy magnesium; and allyloxy magnesium compounds such as ethoxypropoxy magnesium, butoxyethoxy magnesium, phenoxy magnesium, and dimethylphenoxy magnesium. These magnesium compounds can be used alone or in combination of two or more types.

[0134] The electron donor compound used for component (a) preferably contains a phthalate-based compound as an essential component. When a catalyst (X) containing a phthalate-based compound as an electron donor is used, propylene polymer M can be readily obtained. w / M nPolypropylene-based resins within the aforementioned range. Additionally, when using a Ziegler-Natta catalyst to polymerize ethylene / α-olefin copolymers, components with varying contents of ethylene-derived units (a so-called compositional distribution) are typically produced, while using a catalyst (X) containing a phthalate-based compound as an electron donor, copolymers with a broad compositional distribution can be obtained. Therefore, it is considered easy to produce two components, one with a particularly high content of ethylene-derived units effective for impact resistance at low temperatures compared to the average of the copolymer, and the other with a particularly low content of ethylene-derived units effective for interfacial affinity with the propylene polymer compared to the average of the copolymer. As a result, by using a catalyst (X) containing a phthalate-based compound as an electron donor, even when polymerizing ethylene / α-olefin copolymers with a relatively high content of ethylene-derived units to improve impact resistance at extremely low temperatures, interfacial affinity with the propylene polymer is maintained, thus maintaining a balance between rigidity and impact resistance.

[0135] Examples of compounds based on phthalate esters include monoethyl phthalate, dimethyl phthalate, methyl ethyl phthalate, monoisobutyl phthalate, mono-n-butyl phthalate, diethyl phthalate, ethyl isobutyl phthalate, ethyl n-butyl phthalate, di-n-propyl phthalate, diisopropyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, di-n-heptyl phthalate, di-n-ethylhexyl phthalate, di-n-octyl phthalate, dinepentyl phthalate, didecyl phthalate, benzyl butyl phthalate, and diphenyl phthalate. Diisobutyl phthalate is particularly preferred.

[0136] Examples of electron donor compounds in solid catalysts, other than phthalate-based compounds, include succinate-based compounds and diether-based compounds.

[0137] Compounds based on succinates can be esters of succinic acid, or substituted esters of succinic acid having a substituent such as an alkyl group at the first or second position. Specific examples include diethyl succinate, dibutyl succinate, diethyl methyl succinate, diethyl diisopropyl succinate, diallyl ethyl succinate, etc.

[0138] Examples of diether-based compounds include 1,3-diethers, such as 2-(2-ethylhexyl)-1,3-dimethoxypropane, 2-isopropyl-1,3-dimethoxypropane, 2-butyl-1,3-dimethoxypropane, 2-sec-butyl-1,3-dimethoxypropane, 2-cyclohexyl-1,3-dimethoxypropane, 2-phenyl-1,3-dimethoxypropane, 2-tert-butyl-1,3-dimethoxypropane, 2-cumyl-1,3-dimethoxypropane, 2-(2-phenylethyl)-1,3-dimethoxypropane, 2-(2-cyclohexylethyl)-1,3-dimethoxypropane, 2-(p-chlorophenyl)-1,3-dimethoxypropane, 2-(diphenylmethyl)-1,3-dimethoxypropane, 2-( 1-Naphthyl)-1,3-dimethoxypropane, 2-(p-fluorophenyl)-1,3-dimethoxypropane, 2-(1-decahydronaphthyl)-1,3-dimethoxypropane, 2-(p-tert-butylphenyl)-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane, 2,2-diethyl-1,3-dimethoxypropane, 2,2-dipropyl-1,3-dimethoxypropane, 2,2-dibutyl-1,3-dimethoxypropane, 2,2-diethyl-1,3-diethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane, 2,2-dipropyl-1,3-diethoxypropane, 2,2-dibutyl-1,3-diethoxypropane, 2-methyl-2-ethyl-1,3-di Methoxypropane, 2-methyl-2-propyl-1,3-dimethoxypropane, 2-propyl-2-pentyl-1,3-diethoxypropane, 2-methyl-2-benzyl-1,3-dimethoxypropane, 2-methyl-2-phenyl-1,3-dimethoxypropane, 2-methyl-2-cyclohexyl-1,3-dimethoxypropane, 2-methyl-2-methylcyclohexyl-1,3-dimethoxypropane, 2,2-bis(p-chlorophenyl)-1,3-dimethoxypropane, 2,2-bis(2-phenylethyl)-1,3-dimethoxypropane, 2,2-bis(2-cyclohexylethyl)-1,3-dimethoxypropane, 2-methyl-2-isobutyl-1,3-dimethoxypropane, 2-methyl-2-(2-ethylhexyl)-1... 3-Dimethoxypropane, 2,2-bis(2-ethylhexyl)-1,3-dimethoxypropane, 2,2-bis(p-methylphenyl)-1,3-dimethoxypropane, 2-methyl-2-isopropyl-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2,2-diphenyl-1,3-dimethoxypropane, 2,2-dibenzyl-1,3-dimethoxypropane, 2-isopropyl-2-cyclopentyl-1,3-dimethoxypropane, 2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-diethoxypropane, 2,2-diisobutyl-1,3-dibutoxypropane, 2-isobutyl-2-isopropyl-1,3-dimethoxypropane, 2,2-Di-sec-butyl-1,3-dimethoxypropane, 2,2-di-tert-butyl-1,3-dimethoxypropane, 2,2-dineopentyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2-phenyl-2-benzyl-1,3-dimethoxypropane, 2-cyclohexyl-2-cyclohexylmethyl-1,3-dimethoxypropane, etc.

[0139] Other specific examples of compounds based on 1,3-diethers include the following compounds.

[0140] 1,1-bis(methoxymethyl)-cyclopentadiene; 1,1-bis(methoxymethyl)-2,3,4,5-tetramethylcyclopentadiene; 1,1-bis(methoxymethyl)-2,3,4,5-tetraphenylcyclopentadiene; 1,1-bis(methoxymethyl)-2,3,4,5-tetrafluorocyclopentadiene; 1,1-bis(methoxymethyl)-3,4-dicyclopentylcyclopentadiene; 1,1-bis(methoxymethyl)indene; 1,1-bis(methoxymethyl)-2,3-dimethylindene; 1,1-bis(methoxymethyl)-4,5,6,7-tetrahydroindene; 1,1-bis(methoxymethyl)-2,3,6,7-tetrafluoroindene; 1,1-bis(methoxymethyl)- 4,7-Dimethylindene; 1,1-Bis(methoxymethyl)-3,6-Dimethylindene; 1,1-Bis(methoxymethyl)-4-phenylindene; 1,1-Bis(methoxymethyl)-4-phenyl-2-methylindene; 1,1-Bis(methoxymethyl)-4-cyclohexylindene; 1,1-Bis(methoxymethyl)-7-(3,3,3-trifluoropropyl)indene; 1,1-Bis(methoxymethyl)-7-trimethylsilylindene; 1,1-Bis(methoxymethyl)-7-trifluoromethylindene; 1,1-Bis(methoxymethyl)-4,7-dimethyl-4,5,6,7-tetrahydroindene; 1,1-Bis(methoxymethyl)-7-methylindene; 1,1-Bis(methoxymethyl) 1,1-Bis(methoxymethyl)-7-isopropylindene; 1,1-Bis(methoxymethyl)-7-cyclohexylindene; 1,1-Bis(methoxymethyl)-7-tert-butylindene; 1,1-Bis(methoxymethyl)-7-tert-butyl-2-methylindene; 1,1-Bis(methoxymethyl)-7-phenylindene; 1,1-Bis(methoxymethyl)-2-phenylindene; 1,1-Bis(methoxymethyl)-1H-benzo[a]indene; 1,1-Bis(methoxymethyl)-1H-2-methylbenzo[a]indene; 9,9-Bis(methoxymethyl)fluorene; 9,9-Bis(methoxymethyl)-2,3,6,7-tetramethylfluorene; 9,9-Bis(methoxymethyl)- 2,3,4,5,6,7-Hexafluorofluorene; 9,9-bis(methoxymethyl)-2,3-benzo[a]fluorene; 9,9-bis(methoxymethyl)-2,3,6,7-dibenzo[a]fluorene; 9,9-bis(methoxymethyl)-2,7-diisopropylfluorene; 9,9-bis(methoxymethyl)-1,8-dichlorofluorene; 9,9-bis(methoxymethyl)-2,7-dicyclopentylfluorene; 9,9-bis(methoxymethyl)-1,8-difluorofluorene; 9,9-bis(methoxymethyl)-1,2,3,4-tetrahydrofluorene; 9,9-bis(methoxymethyl)-1,2,3,4,5,6,7,8-octahydrofluorene; 9,9-bis(methoxymethyl)-4-tert-butylfluorene.

[0141] Examples of halogen atoms constituting component (a) include fluorine, chlorine, bromine, iodine or mixtures thereof, with chlorine being particularly preferred.

[0142] Examples of organoaluminum compounds in component (b) include trialkylaluminum such as triethylaluminum and tributylaluminum; trienylaluminum such as triisopentenylaluminum; alkoxydialkylaluminum such as ethoxydiethylaluminum and butoxydibutylaluminum; sesquialkoxyalkylaluminum such as sesquiethoxyethylaluminum and sesquibutoxybutylaluminum; having an average composition of R 1 2.5 Al(OR 2 ) 0.5 (R 1 and R 2 These are partially alkoxylated alkyl aluminum groups (which may be different or the same); dialkyl halides such as diethylaluminum chloride, dibutylaluminum chloride, and diethylaluminum bromide; sesquihalinated alkyl aluminum groups such as ethylaluminum sesquichloride, butylaluminum sesquichloride, and ethylaluminum sesquibromide; partially halogenated alkyl aluminum groups such as dialkyl halides, for example, ethylaluminum dichloride, propylaluminum dichloride, and butylaluminum dibromide; partially hydrogenated alkyl aluminum groups such as dialkyl hydrides, such as diethylaluminum hydride and dibutylaluminum hydride; dihydrogenated alkyl aluminum groups such as ethylaluminum dihydrogenide and propylaluminum dihydrogenide; and partially alkoxylated and halogenated alkyl aluminum groups such as ethoxyethylaluminum chloride, butoxybutylaluminum chloride, and ethoxyethylaluminum bromide. Component (b) above can be used alone or in combination of two or more types.

[0143] As the external electron donor compound for component (c), an organosilicon compound is used.

[0144] Preferred organosilicon compounds include, for example, trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, tert-butylmethyldimethoxysilane, tert-butylmethyldiethoxysilane, tert-pentylmethyldiethoxysilane, diphenyldimethoxysilane, phenylmethyldimethoxysilane, diphenyldiethoxysilane, di-o-tolyldimethoxysilane, di-m-tolyldimethoxysilane, di-p-tolyldimethoxysilane, di-p-tolyldiethoxysilane, diethylphenyldimethoxysilane, dicyclopentyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, ethyl... Trimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, methyltrimethoxysilane, n-propyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, phenyltrimethoxysilane, γ-chloropropyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, tert-butyltriethoxysilane, hexyltrimethoxysilane, n-butyltriethoxysilane, isobutyltriethoxysilane, phenyltriethoxysilane, γ-aminopropyltriethoxysilane, chlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, 2-norbornanetrimethoxysilane, 2-norbornanetriethoxysilane Alkane, 2-norbornene methyl dimethoxysilane, ethyl silicate, butyl silicate, trimethylphenoxysilane, methyltrienylpropoxysilane, vinyltris(β-methoxyethoxysilane), vinyltriacetoxysilane, dimethyltetraethoxydisiloxane, methyl(3,3,3-trifluoro-n-propyl)dimethoxysilane, cyclohexylethyldimethoxysilane, cyclopentyl-tert-butoxydimethoxysilane, diisobutyldimethoxysilane, isobutylisopropyldimethoxysilane, n-propyltrimethoxysilane, di-n-propyldimethoxysilane, tert-butylethyldimethoxysilane, tert-butylpropyldimethoxysilane, tert-butyl-tert-butoxydimethoxysilane, isobutyltrimethoxysilane, cyclohexylisobutyldimethoxysilane Oxysilanes, di-sec-butyldimethoxysilane, isobutylmethyldimethoxysilane, bis(decahydroisoquinoline-2-yl)dimethoxysilane, diethylaminotriethoxysilane, dicyclopentylbis(ethylamino)silane, tetraethoxysilane, tetramethoxysilane, isobutyltriethoxysilane, tert-butyltrimethoxysilane, isobutyltrimethoxysilane, isobutylsec-butyldimethoxysilane, ethyl(perhydroisoquinoline-2-yl)dimethoxysilane, tris(isopropenoxy)phenylsilane, isobutylisopropyldimethoxysilane, cyclohexylisobutyldimethoxysilane, cyclopentylisobutyldimethoxysilane, cyclopentylisopropyldimethoxysilane, phenyltriethoxysilane, p-tolylmethyldimethoxysilane, etc.

[0145] Among them, the preferred formulations are ethyltriethoxysilane, n-propyltriethoxysilane, n-propyltrimethoxysilane, tert-butyltriethoxysilane, tert-butylmethyldimethoxysilane, tert-butylmethyldiethoxysilane, tert-butylethyldimethoxysilane, tert-butylpropyldimethoxysilane, tert-butyltert-butoxydimethoxysilane, tert-butyltrimethoxysilane, isobutyltrimethoxysilane, isobutylmethyldimethoxysilane, isobutylsec-butyldimethoxysilane, ethyl(perhydroisoquinoline-2-yl)dimethoxysilane, bis(decahydroisoquinoline-2-yl)dimethoxysilane, tris(isopropenoxy)phenylsilane, hexyltrimethoxysilane, vinyltriethoxysilane, phenyltriethoxysilane, phenyltrimethoxysilane, vinyltributoxysilane, diphenyldimethoxysilane, diisopropyldimethoxysilane, and diisobutyl Dimethoxysilane, isobutylisopropyldimethoxysilane, cyclopentyltert-butoxydimethoxysilane, dicyclopentyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylisobutyldimethoxysilane, cyclopentylisobutyldimethoxysilane, cyclopentylisopropyldimethoxysilane, disec-butyldimethoxysilane, diethylaminotriethoxysilane, tetraethoxysilane, tetramethoxysilane, isobutyltriethoxysilane, phenylmethyldimethoxysilane, phenyltriethoxysilane, bis(p-tolyl)dimethoxysilane, p-tolylmethyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylethyldimethoxysilane, 2-norbornanetriethoxysilane, 2-norbornanemethyldimethoxysilane, diphenyldiethoxysilane, methyl(3,3,3-trifluoropropyl)dimethoxysilane, ethyl silicate, etc. The above component (c) can be used alone or in combination of two or more types.

[0146] Organosilicon compounds play a particularly important role in regulating the amount of the insoluble portion of xylene. When other catalyst components are the same, the amount of the insoluble portion of xylene depends on the type and amount of the organosilicon compound and the polymerization temperature. However, even when a suitable organosilicon compound is used, the amount of the insoluble portion of xylene decreases significantly when the amount of the organosilicon compound is below a certain value typically found only in diether catalysts. Therefore, when the polymerization temperature is 75°C, the lower limit of the molar ratio of organosilicon compound to organoaluminum compound (organosilicon compound / organoaluminum compound) is preferably 0.015, more preferably 0.018. The upper limit of this ratio is preferably 0.30, more preferably 0.20, and even more preferably 0.10. That is, examples include the following ranges: 0.015 to 0.30, 0.015 to 0.20, 0.015 to 0.10, 0.018 to 0.30, 0.018 to 0.20, and 0.018 to 0.10.

[0147] When phthalate-based compounds are used as internal electron donor compounds, the increased polymerization temperature leads to an increase in the insoluble portion of xylene, and thus lowers the lower and upper limits of the preferred molar ratio (organosilicon / organoaluminum) of the organosilicon compound and the organosilicone compound. Specifically, when using phthalate-based compounds to polymerize at 80°C, the lower limit of the molar ratio is preferably 0.010, more preferably 0.015, and even more preferably 0.018. The upper limit of the molar ratio is preferably 0.20, more preferably 0.14, and even more preferably 0.08. That is, examples include the following ranges: 0.010 to 0.20, 0.010 to 0.14, 0.010 to 0.08, 0.015 to 0.20, 0.015 to 0.14, 0.015 to 0.08, 0.018 to 0.20, 0.018 to 0.14, and 0.018 to 0.08.

[0148] As catalyst (X), preferred component (b) is trialkylaluminum, such as triethylaluminum or triisobutylaluminum, and component (c) is an organosilicon compound such as dicyclopentyldimethoxysilane, cyclohexylmethyldimethoxysilane, or diisopropyldimethoxysilane.

[0149] The method of obtaining a polymer mixture by multi-stage polymerization is not limited to the above, and the propylene polymer (component (a1)) can be polymerized in multiple polymerization reactors, or the ethylene / α-olefin copolymer (component (a2)) can be polymerized in multiple polymerization reactors.

[0150] Another method for obtaining a polymer mixture is by using a polymerization vessel with a monomer concentration gradient or polymerization conditions. In such a polymerization vessel, for example, a vessel in which at least two polymerization zones are connected can be used, and the monomers can be polymerized by gas-phase polymerization.

[0151] Specifically, in the presence of a catalyst, monomers are supplied and polymerized in a polymerization zone consisting of risers, monomers are supplied and polymerized in a downcomer connected to the risers, and polymerization occurs between the risers and downcomers while circulating, and the polymerization products are collected. The method includes means for completely or partially preventing the gas mixture present in the risers from entering the downcomers. Furthermore, a gas and / or liquid mixture having a different composition from the gas mixture present in the risers is introduced into the downcomers. For this polymerization method, the method described, for example, in Japanese Patent Publication No. 2002-520426, can be applied.

[0152] <Sheet Molded Products>

[0153] The sheet molded articles of the present invention are formed by molding the polypropylene-based resin composition of the present invention. Figure 1A roll of sheet molding 10 is shown as an example of the present invention.

[0154] The sheet molded articles of the present invention can be produced, for example, by a casting molding method.

[0155] It is achieved at a molding temperature of, for example, 150°C to 350°C, preferably 170°C to 250°C.

[0156] The thickness of the sheet molded article of the present invention can be, for example, greater than 0.1 mm to 2.0 mm, preferably greater than 0.1 mm to 1.0 mm, more preferably greater than 0.1 mm to 0.5 mm, and even more preferably greater than 0.1 mm to 0.4 mm.

[0157] The thickness of sheet molded articles is measured using known measurement methods such as beta-ray film thickness gauges.

[0158] Because the sheet molded articles of the present invention have excellent low-temperature impact resistance, they can be used in low-temperature environments, for example, -50°C to -10°C, preferably -45°C to -20°C, and more preferably -40°C to -30°C.

[0159] When measured by the following test method, the high-rate impact (unit: J) of the sheet molded article of the present invention is preferably more than 20 (>20) at -40°C, and the higher the value, the more preferred.

[0160] The sheet peeling of the sheet molded articles of the present invention is preferably "0" or higher, which will be described later.

[0161] The rigidity (stiffness) of the sheet molded article of the present invention is preferably 500 MPa or greater, more preferably 700 MPa or greater, and even more preferably 900 MPa or greater, and the higher the stiffness, the more preferred. Here, the stiffness is a value measured by the test method described below.

[0162] [Example of an embodiment]

[0163] Examples and comparative examples are shown below, but the present invention is not limited to the following examples.

[0164] <Preparation of Copolymer 1>

[0165] A solid catalyst in which TiCl4 and diisobutyl phthalate are supported on MgCl2 as internal donors is prepared by the method described in lines 46 to 53 of Example 5 of European Patent No. 728769. Specifically, it is carried out as follows.

[0166] The following method was used to prepare microprolate MgCl2·2·1C2H5OH. In a 2L autoclave equipped with a turbine stirrer and pipette, 48g of anhydrous MgCl2, 77g of anhydrous C2H5OH, and 830mL of kerosene were placed in an inert gas atmosphere at room temperature. The contents were heated to 120°C with stirring to obtain an adduct of MgCl2 and alcohol, which was melted and mixed with a dispersant. The nitrogen pressure inside the autoclave was maintained at 15 atm. The pipette of the autoclave was heated to 120°C using a heating jacket. The pipette had an inner diameter of 1mm and a length of 3m from one end of the heating jacket to the other. The mixture flowed through the pipette at a speed of 7m / s. At the outlet of the pipette, the dispersion was collected with stirring into a 5L flask containing 2.5L of kerosene and cooled externally with a jacket maintained at an initial temperature of -40°C. The final temperature of the dispersion was 0°C. The spherical solid product constituting the emulsion dispersion was allowed to settle, separated by filtration, washed with heptane, and dried. All these operations were carried out under an inert gas atmosphere. MgCl₂·3C₂H₅OH in the form of solid spherical particles with a maximum diameter of 50 μm or smaller was obtained. The yield was 130 g. An alcohol-free product was obtained by gradually increasing the temperature from 50 °C to 100 °C in a nitrogen stream until the alcohol content per mole of MgCl₂ decreased to 2.1 mol.

[0167] 225 mL of TiCl4 was added to a 500 mL cylindrical glass reactor equipped with a filter barrier at 0 °C, and 10.1 g (54 mmol) of the microspheres MgCl2·2·1C2H5OH obtained above was added while stirring the contents for 15 minutes. The temperature was then raised to 40 °C and 9 mmol of diisobutyl phthalate was added. The temperature was raised to 100 °C over 1 hour and stirring was continued for an additional 2 hours. TiCl4 was then removed by filtration, and 200 mL of TiCl4 was added, with stirring at 120 °C for an additional hour. Finally, the contents were filtered and washed with n-heptane at 60 °C until the filtrate was completely free of chloride ions. The resulting catalyst composition contained 3.3 wt% Ti and 8.2 wt% diisobutyl phthalate.

[0168] Then, the above-mentioned solid catalyst (triethylaluminum (TEAL) as an organoaluminum compound and dicyclopentyldimethoxysilane (DCPMS) as an external electron donor compound) was used in an amount such that the weight ratio of TEAL to solid catalyst was 20 and the weight ratio of TEAL / DCPMS was 10 (when the molar ratio of organosilicon compound / organoaluminum compound was 0.05) and the mixture was contacted at 12°C for 24 minutes to obtain catalyst (X).

[0169] Prepolymerization was carried out by keeping the thus obtained catalyst (X) in suspension in liquid propylene at 20°C for 5 minutes.

[0170] The obtained prepolymer product is introduced into the first-stage polymerization reactor of a polymerization apparatus equipped with two-stage polymerization reactors connected in series, and propylene is supplied to produce a propylene homopolymer. Subsequently, the propylene homopolymer, propylene, and ethylene are supplied to the second-stage polymerization reactor to produce an ethylene / propylene copolymer. During polymerization, temperature and pressure are regulated, and hydrogen is used as a molecular weight regulator.

[0171] The polymerization temperature and reactant ratios were as follows: in the first reactor, the polymerization temperature and hydrogen concentration were 80°C and 0.012 mol%, respectively, and in the second reactor, the polymerization temperature, hydrogen concentration, and the ratio of ethylene to the total amount of ethylene and propylene were 80°C, 1.06 mol%, and 0.49 mol%, respectively. Furthermore, the residence time distribution in the first and second stages was adjusted so that the amount of the ethylene / propylene copolymer was 35% by weight. The target copolymer 1 was obtained using the above method.

[0172] The obtained copolymer 1 is a polymeric mixture of component (a1) and component (a2), wherein component (a1) is a propylene polymer constituting the continuous phase, component (a2) is an ethylene / propylene copolymer constituting the rubber phase, and is a polypropylene-based resin (A).

[0173] For copolymer 1, the molecular weight distribution Mw / Mn of component (a1), the content of ethylene-derived units of component (a1), the average pore size (Dn) of component (a1), the weight ratio of component (a2) / [component (a1) + component (a2)], the content of ethylene-derived units of component (a2), the XSIV of component (a1) + component (a2), and the MFR of component (a1) + component (a2) are shown in Table 1.

[0174] In Table 1, catalyst (X) containing a phthalate-based compound as component (a) is designated "Pht", and catalyst (X) containing a succinate-based compound as component (a) is designated "Suc". Catalyst (X) obtained by the above method is designated "Pht-1" in Table 1.

[0175] <Preparation of copolymers 2 to 3>

[0176] The ratio of ethylene to the total amount of ethylene and propylene in the second reactor was changed so that the content of ethylene-derived units in component (a2) was as shown in Table 1. Otherwise, copolymers 2 to 3 were obtained using the same manufacturing method as in the case of copolymer 1.

[0177] <Preparation of copolymer r1>

[0178] A solid catalyst in which Ti and diisobutyl phthalate are supported on MgCl2 as internal donors is prepared by the method described in paragraph 0032, lines 21 to 36 of JP-A-2004-27218. Specifically, it is carried out as follows.

[0179] Under a nitrogen atmosphere and at 120°C, 56.8 g of anhydrous magnesium chloride was completely dissolved in 100 g of anhydrous ethanol, 500 mL of petrolatum oil "CP15N" manufactured by Idemitsu Kosan Co., Ltd., and 500 mL of silicone oil "KF96" manufactured by Shin-Etsu Silicone Co., Ltd. The solution was stirred for 2 minutes at 120°C and 5000 rpm using a TK homogeneous mixer manufactured by Tokushu Kika Kogyo Co., Ltd. While maintaining stirring, it was poured into 2 L of anhydrous heptane not exceeding 0°C. The resulting white solid was thoroughly washed with anhydrous heptane, dried under vacuum at room temperature, and further partially deethanolinated under a nitrogen stream to obtain 30 g of spherical solid MgCl2·1.2C2H5OH.

[0180] 30 g of the above spherical solid was suspended in 200 mL of anhydrous heptane. While stirring at 0 °C, 500 mL of titanium tetrachloride was added dropwise over 1 hour. Next, when heating began and the temperature reached 40 °C, 4.96 g of diisobutyl phthalate was added, and the temperature was raised to 100 °C over approximately 1 hour. After reacting at 100 °C for 2 hours, the solid fraction was collected by hot filtration. Subsequently, 500 mL of titanium tetrachloride was added to the reaction mixture and stirred, followed by reaction at 120 °C for 1 hour. After the reaction was complete, the solid fraction was again collected by hot filtration and washed 7 times with 1.0 L of hexane at 60 °C, and 3 times with 1.0 L of hexane at room temperature to obtain a solid catalyst. The titanium content in the obtained solid catalyst fraction was measured and found to be 2.36% by weight.

[0181] Using the aforementioned solid catalyst, the residence time distribution in the first and second stages was altered so that the weight ratio of component (a2) / [component (a1) + component (a2)] was as shown in Table 1. Otherwise, copolymer r1 was obtained using the same manufacturing method as copolymer 1.

[0182] The catalyst (X) obtained here after contact with TEAL and DCPMS is indicated as "Pht-2" in Table 1.

[0183] <Preparation of copolymers r2 to r3>

[0184] The ratio of ethylene to the total amount of ethylene and propylene in the second-stage reactor was changed so that the content of ethylene-derived units in component (a2) was as shown in Table 1. Otherwise, copolymer r2 was obtained in the same manner as copolymer 1. Regarding copolymer r3, the target copolymer could not be obtained because the content of ethylene-derived units in component (a2) was high and production was difficult (values ​​in Table 1 other than ΔHc are target values).

[0185] <Preparation of copolymers r4 to r5>

[0186] The hydrogen concentration in the second-stage reactor was changed so that the XSIV of component (a1) + component (a2) was the value listed in Table 1, and the hydrogen concentration in the first stage was also adjusted to adjust the MFR of component (a1) + component (a2) to the value listed in Table 1. Apart from the above, copolymers r4 to r5 were obtained in the same manner as in copolymer 1.

[0187] <Preparation of copolymer r6>

[0188] The hydrogen concentration in the first stage was adjusted to change the MFR of component (a1) + component (a2) to the values ​​shown in Table 1. Otherwise, copolymer r6 was obtained using the same manufacturing method as in the case of copolymer 1.

[0189] <Preparation of copolymer 4>

[0190] According to the preparation method described in the example of Japanese Patent Application Publication No. 2011-500907, a solid catalyst is prepared using the following procedure.

[0191] At 0 °C, 250 mL of TiCl4 was introduced into a 500 mL four-necked round-bottom flask purged with nitrogen. With stirring, 10.0 g of microspheres of MgCl2·1.8C2H5OH (prepared according to the method described in Example 2 of USP-4,399,054, but operated at 3000 rpm instead of 10000 rpm) and 9.1 mmol of diethyl 2,3-(diisopropyl)succinate were added. The temperature was raised to 100 °C and maintained for 120 min. Then, stirring was stopped, the solid product was allowed to settle, and the supernatant was aspirated. This process was then repeated twice: 250 mL of fresh TiCl4 was added, the mixture was reacted at 120 °C for 60 min, and the supernatant was aspirated. The solid was washed six times at 60 °C with anhydrous hexane (6 × 100 mL).

[0192] The solid catalyst, TEAL, and DCPMS were brought into contact with each other at room temperature for 5 minutes with a TEAL to solid catalyst weight ratio of 18 and a TEAL / DCPMS weight ratio of 10. Prepolymerization was then carried out by keeping the obtained catalyst (X) in suspension in liquid propylene at 20°C for 5 minutes.

[0193] The obtained prepolymer product is introduced into the first-stage polymerization reactor of a polymerization apparatus equipped with two-stage polymerization reactors connected in series, and propylene is supplied to produce a propylene homopolymer. Subsequently, the propylene homopolymer, propylene, and ethylene are supplied to the second-stage polymerization reactor to produce an ethylene / propylene copolymer. During polymerization, temperature and pressure are regulated, and hydrogen is used as a molecular weight regulator.

[0194] The polymerization temperature and reactant ratios were as follows: in the first reactor, the polymerization temperature and hydrogen concentration were 80°C and 0.030 mol%, respectively, and in the second reactor, the polymerization temperature, hydrogen concentration, and the ratio of ethylene to the total amount of ethylene and propylene were 80°C, 1.06 mol%, and 0.44 mol%, respectively. Furthermore, the residence time distribution in the first and second stages was adjusted so that the weight ratio of component (a2) / [component (a1) + component (a2)] was 35 wt%. The copolymer 4 shown in Table 1 was obtained using the above method.

[0195] Copolymers 2 to 4, r1 to r6 obtained therefrom were measured in the same manner as copolymer 1, and the results are shown in Table 1.

[0196] [Table 1]

[0197]

[0198] The measurements in Table 1 were taken using the following methods.

[0199] <Mw / Mn of component (a1)>

[0200] A 2.5g sample of the component (a1) polymerized in the first stage reactor was used as the measurement sample, and the number-average molecular weight (Mn) and weight-average molecular weight (Mw) were measured. The weight-average molecular weight (Mw) was divided by the number-average molecular weight (Mn) to determine the molecular weight distribution (Mw / Mn).

[0201] The apparatus used was a PL GPC220 manufactured by Polymer Labs. The mobile phase was 1,2,4-trichlorobenzene containing an antioxidant, and the columns were UT-G (1 column), UT-807 (1 column), and UT-806M (2 columns) manufactured by Showa Denko Co., Ltd., connected in series. A differential refractometer was used as the detector. The same solvent as the mobile phase was used as the sample solution solvent, and a measurement sample with a concentration of 1 mg / mL was prepared by dissolving the sample at 150°C with stirring for 2 hours. 500 μL of the obtained sample solution was injected into the column, and measurements were taken at a flow rate of 1.0 mL / min, a temperature of 145°C, and a data collection interval of 1 second. The columns were calibrated using a triple approximation method with polystyrene standard samples (Shodex standards, manufactured by Showa Denko KK) with molecular weights ranging from 5.8 million to 7.45 million. The Mark-Houwink-Sakurada coefficient for using polystyrene standard samples is K = 1.21 x 10⁻⁶. -4 α = 0.707, and the Mark-Houwink-Sakurada coefficients for polypropylene homopolymers, propylene random copolymers, and polypropylene-based polymers are K = 1.37 × 10⁻⁶. -4 And α = 0.75.

[0202] <Average pore size of component (a1)>

[0203] A 2.5g sample of component (a1) polymerized in the first stage reactor was used as the measurement sample, and the pore size D in the range of 1μm to 100μm was measured using the mercury intrusion porosimetry method as specified in JISR 1655 using a fully automated pore distribution measuring device manufactured by Quanta Chrome Pore Master 60-GT, and the average pore size Dn was calculated using the following formula.

[0204] Dn=∫(-dV / dlogD)dlogD / ∫(1 / D)(-dV / dlogD)dlogD

[0205] Here, V is the sample volume, which corresponds to the value obtained by subtracting the pore volume from the volume of each particle (total volume).

[0206] <Total ethylene content of the copolymer, content of ethylene-derived units in component (a1)>

[0207] For copolymer samples dissolved in a mixed solvent of 1,2,4-trichlorobenzene / deuterated benzene, AVANCE III HD400 manufactured by Bruker was used. 13 The C-resonance frequency (100MHz) is obtained under the following conditions.13 C-NMR spectroscopy: measurement temperature 120℃, flip angle 45 degrees, pulse interval 7 seconds, sample rotation speed 20 Hz, and integration times 5000.

[0208] Using the spectra obtained above, the total ethylene content (wt%) of the copolymer was determined by the method described in the literature by Kakugo, Y. Naito, K. Mizunuma and T. Miyatake, Macromolecules, 15, 1150 to 1152 (1982).

[0209] In addition, when measuring component (a1) as a sample, the total ethylene content (wt%) obtained by the above method is the ethylene unit content (wt%) of component (a1).

[0210] <Ethylene unit content in component (a2)>

[0211] The ethylene unit content (wt%) of component (a2) is determined by calculation in the same manner as the total ethylene content, except that instead of the integral intensity Tββ obtained when the total ethylene content of the copolymer is measured by the method described in the above literature, the integral intensity T'ββ is obtained by using the following formula.

[0212] T'ββ=0.98×Sαγ×A / (1-0.98×A)

[0213] Here, A = Sαγ / (Sαγ+Sαδ), which is calculated from Sαγ and Sαδ as described in the above literature.

[0214] <Weight ratio of component (a2) / [component (a1) + component (a2)]>

[0215] It is determined by the following formula.

[0216] Component (a2) / [Component (a1) + Component (a2)] (unit: weight %) = Total ethylene content of the copolymer / (Ethylene unit content in component (a2) / 100)

[0217] <XSIV of component (a1) + component (a2)>

[0218] The xylene-soluble portion of the copolymer was obtained by the following method, and the intrinsic viscosity (XSIV) of the xylene-soluble portion was measured.

[0219] 2.5 g of the copolymer sample was placed in a flask containing 250 mL of o-xylene (solvent) and stirred at 135 °C for 30 min using a hot plate and reflux apparatus, while purging with nitrogen to ensure complete dissolution. The mixture was then cooled at 25 °C for 1 h. The resulting solution was filtered through filter paper. 100 mL of the filtrate was collected, transferred to an aluminum cup, and evaporated to dryness at 140 °C while purging with nitrogen. The evaporated solution was then allowed to stand at room temperature for 30 min to obtain the xylene-soluble fraction.

[0220] The intrinsic viscosity of tetrahydronaphthalene was measured at 135°C using an automated capillary viscometer (SS-780-H1, manufactured by Shibayama Scientific Instruments Co., Ltd.).

[0221] MFR of component (a1) + component (a2)

[0222] According to JIS K7210-1, 0.05 g of H-BHT manufactured by Honshu Chemical Industry Co., Ltd. was added to 5 g of copolymer sample, and after dry mixing and homogenization, the mixture was measured according to JIS K6921-2 at a temperature of 230 °C and a load of 2.16 kg.

[0223] <DSC of Polypropylene Resin (A)>

[0224] [Heat value (ΔHc) of the crystallization peak between 85℃ and 105℃]

[0225] To standardize the effect of thermal history, approximately 5 mg of sample was taken directly from the granules of polypropylene-based resin (A) (which are each copolymer in Table 1), and differential scanning calorimetry (DSC) was performed using a Q-200 instrument manufactured by TA Instruments according to ISO 11357-1 and ISO 11357-3 after weighing with an electronic balance. Specifically, the obtained sample was heated to 230 °C and held for 5 min, then cooled to 30 °C at a cooling rate of 5 °C / min, and differential scanning calorimetry was performed during cooling. In the measurement results, the exothermic peak indicating crystallization was compared between 85 °C and 105 °C with the baseline (the virtual baseline described in ISO 11357-1:2016(en) 3.7.3) and the exothermic peak. The calorific value ΔHc (J / g) of the crystallization peak was determined based on the area enclosed by this region. An example of a DSC plot used for analysis is shown in [reference needed]. Figure 3 middle.

[0226] [Examples and Comparisons]

[0227] Formulate component (A) according to the composition shown in Table 2. Add 12 or 15 parts by weight of component (B), 0.2 parts by weight of B225 (manufactured by BASF) as an antioxidant, and 0.05 parts by weight of calcium stearate (manufactured by Tannan Kagaku Kogyo Co., Ltd.) as a neutralizing agent to a total of 88 or 85 parts by weight of component (A), and stir and mix the mixture for 1 minute using a Henschel mixer. Melt knead and extrude the mixture using a co-rotating twin-screw extruder TEX-30α (manufactured by JSW) at a barrel temperature of 230°C. After cooling the filament in water, cut the filament with a granulator to obtain granules of the polypropylene-based resin composition.

[0228] The obtained pellets are subjected to a sheet molding machine as described below to obtain a sheet molded body.

[0229] However, regarding Examples 1-2 and Comparative Examples 1-2, talc was blended as component (C) in the amounts listed in Table 2 into components (A) and (B) contained in the above-mentioned granules, totaling 100 parts by weight, as a polyolefin masterbatch (talc content 50 wt%, temperature 230°C, MFR 0.4 g / 10 min at a load of 2.16 kg), and then melt-kneaded to form polypropylene-based resin composition granules, which were then subjected to a sheet molding machine described later to obtain a sheet molded body.

[0230] The various physical properties of the sheet molded bodies obtained in each example are evaluated.

[0231] [Table 2]

[0232]

[0233] The components in Table 2 are as follows.

[0234] Component (A) is copolymers 1 to 4 and copolymers r1 to r6 in Table 1.

[0235] Component (B) is high-density polyethylene Novatec HB431 (density 957 kg / m³) manufactured by Japan Polyethylene Co., Ltd. 3 Based on JIS K6922-2, the MFR at 190℃ and 2.16kg load is 0.35g / 10min.

[0236] Component (C) is an inorganic filler, particularly talc;

[0237] Talc: Neotalc UNI05, manufactured by Neolite Kosan Ltd., with a volume average particle size of 5 μm as measured by laser diffraction. Other components are the following additives.

[0238] Antioxidant: B225 manufactured by BASF

[0239] Neutralizing agent: Calcium stearate manufactured by Tannan Chemical Industry Co., Ltd.

[0240] The measurement results and evaluation results in Table 2 are the values measured and evaluated by the following methods.

[0241] <PP plant productivity>

[0242] The ease of producing component (A) using the above method is evaluated on the following four grades.

[0243] “◎”: Excellent = No problems in manufacturing.

[0244] “〇”: Good = No problems in manufacturing.

[0245] “△”: Fair = Difficult to produce, but the production volume and / or fluff (powder) characteristics are slightly poor.

[0246] “×”: Impossible = Problems occurred during production and production could not be completed.

[0247] <Flowability MFR>

[0248] The MFR of the polypropylene-based resin composition is measured according to JIS K7210-1 and under the conditions of a temperature of 230 °C and a load of 2.16 kg based on JIS K6921-2.

[0249] <Sheet moldability>

[0250] Using a 3-type, 3-layer film / sheet molding device manufactured by Thermoplastics Industries Co., Ltd., the temperature from the cylinder to the die is controlled at 250 °C, and the molten resin extruded from the die using pellets as raw materials is taken out, and at the same time cooled and solidified with a cooling roll at a molding speed of 1.0 m / minute to obtain a sheet with a thickness of 400 μm. The formed sheet is conditioned in a constant temperature room at 23 °C for 48 hours or more, and then used as a sample. <00005(此处原内容似乎有误,推测应为0000546)>The formed sheet is conditioned in a constant temperature room at 23 °C for 48 hours or more, and then used as a sample.

[0252] <Rigidity stiffness> <000(此处原内容似乎有误,推测应为0000550)>Based on JIS P8125, for samples cut from sheet material, the load was measured by bending a 5cm span sheet at a 15° warp angle using a V-5 stiffness tester (model 150-B) manufactured by Taber Instrument Corporation. The stiffness was determined from the observed load.

[0254] High-speed impact

[0255] Based on JIS K7211-2, a puncture impact testing machine (Hydroshot HITS-P10) manufactured by Shimadzu Corporation of Japan was used to impact a sample cut from a sheet at a constant speed at the center of the sample surface using a hydraulically controlled impactor in an atmosphere of -40°C, and the puncture impact test energy was measured from the obtained impact force-displacement diagram.

[0256] <Sheet peeling>

[0257] Using a rotary microtome (model: RU-S) manufactured by Japan Microtome Research Institute Co., Ltd., sections with a thickness of 20 μm were cut from the center of the obtained sheet in a direction perpendicular to the surface. The sections were observed using a polarizing microscope (BX-50) manufactured by Olympus Corporation. The exfoliation state of the interfaces between the propylene polymer (a1), α-olefin copolymer (a2), ethylene / α-olefin polymer (B), and inorganic filler (C) was evaluated in four stages.

[0258] “◎”: Excellent: Not stripped at all.

[0259] “〇”: Good: Slight peeling was observed.

[0260] “△”: Generally: Delamination was observed in some areas.

[0261] "×": Unacceptable: Delamination was observed throughout the process.

[0262] <Sheet Molding Properties>

[0263] The sheets obtained by the above molding method are evaluated at the following three levels.

[0264] "〇": Good: A good product with no problems in shape, thickness, etc.

[0265] "△": Acceptable: Some defective products were found.

[0266] "×": Unacceptable: No good product was obtained.

[0267] <Sheet Productivity>

[0268] When performing the above-mentioned sheet molding, the extent to which sheet productivity was affected by problems such as breakage during molding was evaluated at the following three levels.

[0269] “〇”: Good: No problems and easy to produce.

[0270] "△": Acceptable: There are problems and production is somewhat difficult.

[0271] "×": Impossible: Problems have occurred and it is difficult to produce the sheet.

[0272] <<Effect>>

[0273] Because the sheets according to examples of the present invention use a polypropylene-based resin composition having predetermined physical properties, they exhibit excellent impact resistance even at extremely low temperatures of -40°C. Furthermore, the respective evaluation criteria for rigidity, sheet peeling, sheet moldability, and sheet productivity meet the requirements.

[0274] To improve impact resistance at extremely low temperatures, the inventors have thoroughly investigated the formulation of the entire composition. To exhibit the rubbery properties of the polypropylene-based resin composition even at extremely low temperatures, it was considered possible to increase the content of component (a2) in component (A) or the content of ethylene-derived units in component (a2). However, if these contents are not carefully increased, it becomes difficult to produce the polypropylene-based resin (Comparative Example 3). In this invention, we investigated a formulation that provides sufficient rigidity within a manufacturable range. Furthermore, it is insufficient to simply exhibit rubbery properties; it also needs to be moldable into sheets, thus other parameters such as the XSIV value and MFR of component (a1) + component (a2) were adjusted, and thus the present invention was completed.

[0275] Comparative Example 1-1 has a low content of component (a2) and cannot form a sheet in the first place.

[0276] Comparative Example 1-2 was obtained by reducing the amount of component (B) in Comparative Example 1-1 and adding component (C). Although the sheet had almost no difficulty in formation, the impact resistance at extremely low temperatures was not improved, and the sheet peeling, sheet moldability, and sheet productivity were poor.

[0277] In Comparative Example 2, component (a2) has a low content of ethylene-derived units and poor impact resistance at extremely low temperatures, and although component (A) can be produced with difficulty, its production volume and fluff properties are poor.

[0278] In Comparative Example 3, component (a2) has a high content of ethylene-derived units and cannot produce component (A).

[0279] Due to the low XSIV of component (A), Comparative Example 4 exhibits poor impact resistance at extremely low temperatures.

[0280] In Comparative Example 5, component (A) has an excessively high XSIV, resulting in poor impact resistance at extremely low temperatures, and although component (A) can be manufactured with difficulty, production volume is low. Additionally, the sheet exhibits poor moldability.

[0281] Due to the excessively high fluidity of component (A), Comparative Example 6 exhibited extremely poor sheet moldability (stretch resistance) and sheet productivity, and therefore no sheet samples were obtained for evaluating stiffness and impact resistance at extremely low temperatures.

Claims

1. A polypropylene-based resin composition, comprising: A polypropylene-based resin (A), comprising a continuous phase of a propylene polymer (a1) and a rubber phase of a copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms (a2), and Ethylene / α-olefin polymer (B), wherein the ethylene / α-olefin polymer (B) is a polymer of ethylene and an α-olefin having 2 to 10 carbon atoms, and Inorganic filler (C) as an optional component. The MFR of the polypropylene-based resin composition is 0.1 g / 10 min to 3.0 g / 10 min at a temperature of 230°C and a load of 2.16 kg. The total weight of (A), (B), and (C) is 70% by weight or greater relative to the total weight of the polypropylene-based resin composition. The total weight of (A) and (B) is 50% by weight or greater relative to the total weight of the polypropylene-based resin composition. Relative to a total of 100 parts by weight of (A) and (B), the content of (A) is 99 parts by weight or less, the content of (B) is 1 part by weight or more, and the content of (C) is 0 to 60 parts by weight. The content of ethylene-derived units in the propylene polymer (a1) is 0.5% by weight or less relative to the total weight of the propylene polymer (a1). The content of the copolymer (a2) relative to the total weight of the polypropylene-based resin (A) is 27% to 45% by weight. The content of ethylene-derived units in the copolymer (a2) is from 25% to 85% by weight relative to the total weight of the copolymer (a2). The xylene-soluble portion of the polypropylene-based resin (A) has an intrinsic viscosity of 2.7 dl / g to 5.5 dl / g in tetrahydronaphthalene at 135°C.

2. The polypropylene-based resin composition according to claim 1, wherein the crystallization peak observed between 85°C and 105°C in the DSC measurement of the polypropylene-based resin (A) has a calorific value of 0.5 J / g to 10 J / g.

3. The polypropylene-based resin composition according to claim 1, wherein the propylene polymer (a1) has an average pore size of 8 μm to 50 μm.

4. The polypropylene-based resin composition according to claim 2, wherein the propylene polymer (a1) has an average pore size of 8 μm to 50 μm.

5. A sheet molded article formed from the polypropylene-based resin composition according to claim 1.

6. The sheet molded article according to claim 5, wherein the sheet molded article is used to form a container.

7. A container formed from a sheet molded article according to claim 5.

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