Propylene-based polymer composition for resin sheet, resin sheet and container

Abstract

To provide a propylene-based polymer composition for a resin sheet capable of obtaining a sheet comparatively excellent in rigidity, a resin sheet using the propylene-based polymer composition, and a container.SOLUTION: A propylene-based polymer composition for a resin sheet includes: a propylene-based polymer (A) with 90 mass% or more of a structural unit derived from propylene and having no long-chain branch structure; a propylene-based polymer (B) having a long-chain branch structure; and β-crystal nucleus agent. Based on a total 100 mass% of a content of the propylene-based polymer (A) and a content of the propylene-based polymer (B), a content of the propylene-based polymer (A) is 70 mass% or more, a content of the propylene-based polymer (B) is 0.1 to 30 mass%, and a content of the β-crystal nucleus agent is 1 to 10,000 ppm.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a propylene-based polymer composition for a resin sheet, a resin sheet, and a container. [Background technology]

[0002] Containers for food products, etc. are usually produced by molding a thermoplastic resin composition. In particular, containers obtained by molding a polypropylene-based polymer composition are widely used as containers for food products, etc., because they are lightweight, have high heat resistance, high strength, and are not hygroscopic.

[0003] Such a container can be obtained, for example, by thermoforming a sheet formed from a propylene-based polymer composition. As a resin composition for obtaining such a sheet, for example, Patent Document 1 describes a resin composition for thermoforming sheets containing a propylene-based polymer, and the resin composition contains 3 to 100 wt% of a propylene-based polymer (A) having long chain branches, a melt tension (MT) at 230°C of 3 to 30 g, a MFR at 230°C of 0.2 to 15 g / 10 min, and a xylene soluble component content at 25°C of less than 5 wt%, and 0 to 97 wt% of a propylene-based polymer (B), with respect to a total amount of 100 parts by weight, a MFR at 190°C of 5 g / 10 min or less, and a density of 0.920 to 0.970 g / cm. 3 The composition contains 10 to 300 parts by weight of an ethylene polymer (C) which is a high-density polyethylene. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-203859 A Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, in order to reduce the amount of plastic used, efforts have been made to reduce the thickness of sheets formed from resin compositions, and such thin sheets are required to have improved rigidity.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a propylene-based polymer composition for a resin sheet, which enables a sheet having relatively excellent rigidity to be obtained, and a resin sheet and a container each using the propylene-based polymer composition. [Means for solving the problem]

[0007] The propylene polymer composition for resin sheet according to the present invention contains a propylene polymer (A) containing 90 mass% or more of structural units derived from propylene and having no long chain branches, a propylene polymer (B) having a structure with long chain branches, and a β-crystal nucleating agent, wherein, relative to 100 mass% in total of the content of the propylene polymer (A) and the content of the propylene polymer (B), the content of the propylene polymer (A) is 70 mass% or more, the content of the propylene polymer (B) is 0.1 mass% or more and 30 mass% or less, and the content of the β-crystal nucleating agent is 1 ppm or more and 10,000 ppm or less.

[0008] The propylene polymer composition for resin sheet according to the present invention has a Hencky strain of 3.21 or more and 4.21 or less at which the elongational viscosity is maximized at a temperature at which the ratio of the melting area at the melting peak measured by differential scanning calorimetry (DSC) is 94%.

[0009] The resin sheet according to the present invention comprises the above-mentioned propylene-based polymer composition.

[0010] A container according to the present invention includes the above-mentioned resin sheet. Effect of the Invention

[0011] According to the present invention, it is possible to provide a propylene-based polymer composition for a resin sheet, which can provide a sheet having relatively excellent rigidity, and a resin sheet and a container using the propylene-based polymer composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described, but the present invention is not limited to the following embodiment. In this specification, a numerical range expressed using "to" means a range including the numerical values ​​before and after "to" as the lower and upper limits.

[0013] [Propylene-based polymer composition for resin sheet] In one aspect, the propylene polymer composition according to the present embodiment contains a propylene polymer (A) containing 90 mass% or more of structural units derived from propylene and having no long chain branches, a propylene polymer (B) having a structure with long chain branches, and a β-crystal nucleating agent, wherein the content of the propylene polymer (A) is 70 mass% or more, the content of the propylene polymer (B) is 0.1 mass% or more and 30 mass% or less, and the content of the β-crystal nucleating agent is 1 ppm or more and 10,000 ppm or less, relative to 100 mass% in total of the content of the propylene polymer (A) and the content of the propylene polymer (B).

[0014] <Propylene-based polymer (A)> The propylene polymer (A) contains 90% by mass or more of structural units derived from propylene. The content of the structural units derived from propylene in the propylene polymer (A) is preferably 97% by mass or more and 100% by mass or less, more preferably 99% by mass or more and 100% by mass or less, and even more preferably 100% by mass. That is, the propylene polymer (A) is more preferably a propylene homopolymer.

[0015] The propylene polymer (A) may contain a structural unit derived from at least one selected from the group consisting of ethylene and an α-olefin having 4 to 12 carbon atoms. The content of the structural unit derived from at least one selected from the group consisting of ethylene and an α-olefin having 4 to 12 carbon atoms in the propylene polymer (A) is preferably 10% by mass or less, more preferably 3% by mass or less, and even more preferably more than 0% by mass and 1% by mass or less.

[0016] Examples of the α-olefin having 4 to 12 carbon atoms include 1-butene, 1-hexene, and 1-octene, and 1-butene is preferred. The structural unit derived from an α-olefin having 4 to 12 carbon atoms may be a structural unit derived from one kind of α-olefin alone, or may be a structural unit derived from two or more kinds of α-olefins. In the propylene-based polymer (A), the structural unit derived from at least one kind selected from the group consisting of ethylene and an α-olefin having 4 to 12 carbon atoms is more preferably a structural unit derived from ethylene.

[0017] The propylene polymer (A) does not have a long chain branch structure. The long chain branch structure refers to a branch structure of a molecular chain having a main chain carbon number of several tens or more and a molecular weight of several hundreds or more. The long chain branch structure is distinguished from a short chain branch having a few carbon atoms formed by copolymerization with an α-olefin such as 1-butene.

[0018] Whether a propylene polymer has a long chain branch structure or not depends on the average shrinkage factor (g′ ave The average shrinkage factor (g′ ave When the value is less than 1, it means that a long chain branch structure is present, and the smaller the value, the more the long chain branch structure is present. Since the propylene polymer (A) does not have a long chain branch structure, that is, the average shrinkage factor (g' ave ) has the numeric value of 1.

[0019] The average shrinkage factor (g′ ave) is determined by the following method. First, the propylene-based polymer (A) is dissolved in o-dichlorobenzene as a solvent at a concentration of 20 mg / 10 ml, and measurement is performed using a GPC device equipped with a viscosity detector, a light scattering detector, and an RI detector. For calibration of the light scattering detector (LS) and the viscosity detector (VISC) and for correction of the delay volume between the detectors, NIST polystyrene standard substance F10 (weight average molecular weight Mw 96400, polydispersity index 1.01) is used at a solution concentration of 2 mg / ml. The refractive index increment (dn / dc) of the propylene-based polymer in o-dichlorobenzene is 0.079 ml / g. The dn / dc of the polystyrene standard substance is 0.079 ml / g. To obtain the absolute molecular weight and intrinsic viscosity ([η]; unit is dl / g) from the data of each detector, Malvern's data processing software OmniSEC (version 4.7) is used, and calculations are performed with reference to the literature "Size Exclusion Chromatography Springer (1999)." The refractive index increment is the rate of change of refractive index relative to a change in concentration. Then, the shrinkage factor g' = [η] / [η]0 is calculated from the intrinsic viscosity [η] at any absolute molecular weight M obtained by the above measurement and the intrinsic viscosity [η]0 of the linear polymer at any absolute molecular weight M obtained by calculation. Here, the intrinsic viscosity [η]0 of the linear polymer is calculated from the following formula. [η]0 = 3.44 × 10 -4 ×M 0.669 (dl / g) In the elution time corresponding to logM of 5.0 to 6.0, the elution time is divided into m equal intervals, and the average shrinkage factor g′ is calculated using the following formula: ave Calculate.

[0020]

number

[0021] Here, g′ i is the shrinkage factor g′ in the i-th logM of the elution time divided into m equal intervals for the elution time corresponding to logM = 5.0 to 6.0, and wi is the normalized weight fraction at the i-th logM among m intervals equally spaced with respect to the elution time corresponding to logM = 5.0 to 6.0. The number m of arbitrarily divided sections is determined by dividing the elution time corresponding to logM=5.0-6.0 by the data acquisition interval.

[0022] (Measurement conditions) GPC equipment: HLC-8121GPC / HT (Tosoh Corporation) Light scattering detector: PD2040 (Precision Detectors) Laser light source: Wavelength 685nm Viscosity detector: H502 (Viscotek) GPC column: PLgel MIXED-A LS 300 x 7.5 mm (Agilent) x 3 Sample solution concentration: 1mg / mL ·Injection volume: 300μL ·Measurement temperature: 145℃ Dissolution conditions: Stir at 145℃ for 2 hours Solvent and mobile phase: orthodichlorobenzene (Wako special grade) containing 0.1% by mass of dibutylhydroxytoluene ·Mobile phase flow rate: 1.0mL / min Measurement time: Approximately 1 hour Molecular weight standard: Standard polystyrene Data capture interval: 1.74 seconds

[0023] The melt flow rate (hereinafter, sometimes referred to as "MFR") of the propylene polymer (A) measured under conditions of a temperature of 230°C and a load of 2.16 kg is preferably 0.005 g / 10 min to 30 g / 10 min, more preferably 0.01 g / 10 min to 10 g / 10 min, and even more preferably 0.1 g / 10 min to 8 g / 10 min, from the viewpoint of improving processability. The MFR is a value measured by Method A specified in JIS K7210-1.

[0024] Examples of the method for producing the propylene polymer (A) include a method in which propylene or the like as a raw material is polymerized using a known catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst.

[0025] The polymerization method of the propylene polymer (A) may be a method of polymerization in an inert solvent such as hexane, heptane, toluene, or xylene, a method of polymerization in liquid propylene or ethylene, a method of polymerization in a gas phase state by adding a catalyst to gaseous propylene or ethylene, or a method of polymerization by a combination of these. The polymerization conditions may be those usually adopted.

[0026] <Propylene-based polymer (B)> The propylene polymer (B) has a long chain branched structure. The average shrinkage factor (g' ave ) is less than 1, and from the viewpoint of obtaining a molded article having an excellent Young's modulus after secondary processing, it is preferably 0.95 or less, more preferably 0.8 or less, further preferably 0.7 or less, and particularly preferably 0.5 or less. In addition, the average shrinkage factor (g' ave The average shrinkage factor (g′) is usually greater than or equal to 0.2. ave ) is the average shrinkage factor (g′ ave ) requirements, and the average shrinkage factor (g′ ave The average shrinkage factor (g') of the propylene polymer (B) can be adjusted to the above range by selecting one that satisfies the requirements. ave ) can be determined by the same method as for the propylene polymer (A).

[0027] The propylene polymer (B) contains more than 50% by mass of structural units derived from propylene. The content of structural units derived from propylene in the propylene polymer (B) is preferably 60% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less. The propylene polymer (B) is preferably a propylene homopolymer from the viewpoint of obtaining a molded product having an excellent Young's modulus after secondary processing.

[0028] The propylene polymer (B) may contain a structural unit derived from at least one selected from the group consisting of ethylene and an α-olefin having 4 to 12 carbon atoms. The content of the structural unit derived from at least one selected from the group consisting of ethylene and an α-olefin having 4 to 12 carbon atoms in the propylene polymer (B) is preferably 0.001% by mass or more and 10% by mass or less, more preferably 0.01% by mass or more and 3% by mass or less.

[0029] Examples of the α-olefin having 4 to 12 carbon atoms include 1-butene, 1-hexene, and 1-octene, and 1-butene is preferred. The structural unit derived from an α-olefin having 4 to 12 carbon atoms may be a structural unit derived from one kind of α-olefin alone, or may be a structural unit derived from two or more kinds of α-olefins. In the propylene polymer (B), the structural unit derived from at least one kind selected from the group consisting of ethylene and an α-olefin having 4 to 12 carbon atoms is more preferably a structural unit derived from ethylene.

[0030] The melt flow rate (hereinafter, sometimes referred to as "MFR") of the propylene polymer (B) measured under conditions of a temperature of 230°C and a load of 2.16 kg is preferably 0.001 g / 10 min to 100 g / 10 min, more preferably 0.005 g / 10 min to 30 g / 10 min, and even more preferably 0.01 g / 10 min to 10 g / 10 min, from the viewpoint of improving processability. The MFR is a value measured by Method A specified in JIS K7210-1.

[0031] Examples of the method for producing the propylene polymer (B) include a method of polymerizing the raw material propylene using the catalyst components (X), (Y) and (Z) described in JP-A-2018-203859 as known catalysts.

[0032] The polymerization method for the propylene polymer (B) may be the same as that for the propylene polymer (A).

[0033] The propylene polymer (B) may be a commercially available polypropylene having long chain branches (e.g., WB135HMS and WB140HMS manufactured by Borealis, MFX8, MFX6, and MFX3 manufactured by Japan Polypropylene Corporation, and PF-814 manufactured by Basell, etc.) that is purchased and used.

[0034] The above-mentioned propylene polymer (A) and propylene polymer (B) may contain carbon-14 (14C) as a constituent element, and may be material recycled (mechanically recycled).

[0035] The concentration of carbon-14 (14C) contained in a propylene-based polymer is determined as pMC (percentage of mordern carbon: unit %) by the AMS (Accelerator mass spectrometry) method specified in ISO 16620-2:2019. Carbon-14 (14C) is contained in a certain percentage of carbon-14 (14C) in carbon dioxide in the atmosphere, so it is known that plants that grow by absorbing carbon dioxide from the atmosphere, such as corn and trees, contain 14C. It is also known that fossil resources such as petroleum, which are thought to have been stored underground for a long time, contain almost no carbon-14 (14C). Therefore, by using a plant-derived substance as a raw material for the monomer used in the production of a propylene-based polymer, carbon-14 (14C) can be contained in the constituent elements of the propylene-based polymer.

[0036] In the production of propylene-based polymers, fossil resource-derived monomers (ethylene, propylene, 1-butene, 1-hexene, etc.), plant-derived monomers (ethylene, propylene, 1-butene, 1-hexene, etc.), chemically recycled monomers (ethylene, propylene, 1-butene, 1-hexene, etc.), etc. can be used, and these can be used in combination of two or more. Specific monomer combinations include, for example, fossil resource-derived propylene / plant-derived propylene / chemically recycled propylene, fossil resource-derived propylene / plant-derived propylene / chemically recycled propylene / fossil resource-derived ethylene / plant-derived ethylene / chemically recycled ethylene, fossil resource-derived propylene / plant-derived propylene / chemically recycled propylene / fossil resource-derived 1-butene / plant-derived 1-butene / chemically recycled 1-butene, etc.

[0037] Fossil resource-derived monomers are derived from underground carbon resources such as petroleum, coal, and natural gas, and generally contain almost no carbon-14 (14C). Methods for producing fossil resource-derived monomers include known methods, such as cracking petroleum-derived naphtha and ethane, and dehydrogenating ethane and propane to produce olefins.

[0038] Plant-derived monomers are derived from carbon circulating on the earth's surface as plants and animals, and generally contain a certain percentage of carbon-14 (14C). Methods for producing plant-derived monomers include known methods, such as cracking bionaphtha, vegetable oil, animal oil, etc., dehydrogenation of biopropane, etc., methods of separating alcohol from fermented products such as sugar extracted from plant raw materials such as sugarcane and corn, and subjecting it to a dehydration reaction (JP-T 2010-511634 A, JP-T 2011-506628 A, JP-T 2013-503647 A, etc.), and methods of subjecting ethylene obtained from plant-derived ethanol to a metathesis reaction with n-butene (WO 2007 / 055361 A, etc.).

[0039] Chemical recycling monomers are derived from carbon generated by the decomposition and combustion of waste, and their carbon 14 (14C) content varies depending on the waste. Methods for producing chemical recycling monomers include known methods, such as a method of thermally decomposing waste plastics (JP Patent Publication No. 2017-512246, etc.), a method of cracking waste vegetable oil, waste animal oil, etc. (JP Patent Publication No. 2018-522087, etc.), and a method of gasifying, converting to alcohol, and dehydrating waste such as food waste, biomass waste, food waste, waste oil, waste wood, waste paper, and waste plastics (JP Patent Publication No. 2019-167424, International Publication No. 2021 / 006245, etc.).

[0040] When two or more of fossil resource-derived olefins, plant-derived olefins, and chemically recycled olefins are used, the olefins produced individually may be mixed and used in combinations such as fossil resource-derived olefins / plant-derived olefins, fossil resource-derived olefins / chemically recycled olefins, plant-derived olefins / chemically recycled olefins, and fossil resource-derived olefins / plant-derived olefins / chemically recycled olefins. In addition, a mixture of the above olefin combinations may be produced by using a mixture of combinations such as fossil resource-derived compounds / plant-derived compounds, fossil resource-derived compounds / chemically recycled compounds, plant-derived compounds / chemically recycled compounds, and fossil resource-derived compounds / plant-derived compounds / chemically recycled compounds as raw materials or intermediates in the olefin production process.

[0041] As the propylene-based polymer containing carbon 14 (14C), commercially available propylene-based polymers can be used, such as the "Bornewables" series manufactured by Borealis, the "TRUCIRCLE" series manufactured by SABIC, and the "CirculenRenew" series manufactured by LyondellBasell.

[0042] From the viewpoint of reducing the environmental load, the carbon-14 (14C) concentration of the propylene-based polymer is preferably 0.2 pMC (%) or more, more preferably 0.5 pMC (%) or more, even more preferably 1 pMC (%) or more, even more preferably 5 pMC (%) or more, and particularly preferably 10 pMC (%) or more. From the viewpoint of cost, the carbon-14 (14C) concentration of the propylene-based polymer is preferably 99 pMC (%) or less, more preferably 95 pMC (%) or less, even more preferably 90 pMC (%) or less, even more preferably 70 pMC (%) or less, and particularly preferably 50 pMC (%) or less. The carbon-14 (14C) concentration of the propylene-based polymer can be adjusted by changing the ratio of the fossil resource-derived olefin, the plant-derived olefin, and the chemically recycled olefin used in the production of the propylene-based polymer.

[0043] <β crystal nucleating agent> The β-crystal nucleating agent is a compound capable of forming β-crystals having a hexagonal crystal structure in a propylene-based polymer. The β-crystal nucleating agent is not particularly limited, and various conventionally known β-crystal nucleating agents can be used. Examples of the β-crystal nucleating agent include amide compounds represented by N,N'-dicyclohexyl-2,6-naphthalenedicarboxyamide, N,N'-dicyclohexylterephthalamide, N,N'-diphenylhexanediamide, etc.; tetraoxaspiro compounds; quinacridones represented by quinacridone, quinacridonequinone, etc.; iron oxides having a nanoscale size; alkali or alkaline earth metal salts of carboxylic acids represented by calcium pimelate, potassium 1,2-hydroxystearate, magnesium benzoate, magnesium succinate, magnesium phthalate, etc.; aromatic sulfonic acid compounds represented by sodium benzenesulfonate, sodium naphthalenesulfonate, etc.; diesters or triesters of di- or tribasic carboxylic acids; phthalocyanine pigments represented by phthalocyanine blue, etc.; two-component compounds consisting of component A which is an organic dibasic acid and component B which is an oxide, hydroxide, or salt of a metal of Group IIA of the periodic table; and compositions consisting of a cyclic phosphorus compound and a magnesium compound. Among these, the β-crystal nucleating agent is preferably the amide compound N,N'-dicyclohexyl-2,6-naphthalenedicarboxamide, N,N-dicyclohexylterephthalamide or N,N'-diphenylhexanediamide, more preferably N,N'-dicyclohexyl-2,6-naphthalenedicarboxamide. The β-crystal nucleating agent may be used alone or in combination of two or more kinds.

[0044] In the propylene polymer composition according to the present embodiment, the content of the propylene polymer (A) is 70 mass% or more, the content of the propylene polymer (B) is 0.1 mass% or more and 30 mass% or less, and the content of the β-crystal nucleating agent is 1 ppm or more and 10,000 ppm or less, relative to 100 mass% in total of the content of the propylene polymer (A) and the content of the propylene polymer (B).

[0045] From the viewpoint of obtaining a molded product having an excellent Young's modulus after secondary processing, the content of the propylene-based polymer (A) is preferably 50% by mass or more and 99.99% by mass or less, more preferably 70% by mass or more and 99.9% by mass or less, and even more preferably 90% by mass or more and 99.9% by mass or less, relative to 100% by mass of the total of the content of the propylene-based polymer (A) and the content of the propylene-based polymer (B).

[0046] From the viewpoint of obtaining a molded product having an excellent Young's modulus after secondary processing, the content of the propylene-based polymer (B) is preferably from 0.01 to 50% by mass, more preferably from 0.05 to 30% by mass, and even more preferably from 0.1 to 10% by mass, relative to 100% by mass of the total of the content of the propylene-based polymer (A) and the content of the propylene-based polymer (B).

[0047] From the viewpoint of obtaining a molded product having an excellent Young's modulus after secondary processing, the content of the β-crystal nucleating agent is preferably 0.01 ppm or more and 10,000 ppm or less, more preferably 0.1 ppm or more and 5,000 ppm or less, and even more preferably 0.5 ppm or more and 3,000 ppm or less, relative to 100 mass% of the total content of the propylene-based polymer (A) and the propylene-based polymer (B).

[0048] The propylene-based polymer composition according to the present embodiment may contain various additives, other polymers (resins, elastomers), etc. as other components, if necessary. The additives are not particularly limited, and examples thereof include antioxidants, neutralizing agents, ultraviolet absorbers, antistatic agents, lubricants, nucleating agents, adhesives, antifogging agents, antiblocking agents, and melt flow rate regulators. Examples of the antioxidants include phenol-based antioxidants, phosphorus-based antioxidants, and sulfur-based antioxidants, and a composite antioxidant having a unit having both a phenol-based antioxidant mechanism and a phosphorus-based antioxidant mechanism in one molecule can also be used. Examples of other polymers include elastomers such as styrene-butadiene-styrene copolymers and styrene-based copolymer rubbers obtained by hydrogenating styrene-isoprene-styrene copolymers. The content of other components in the propylene-based polymer composition is not particularly limited, and is appropriately set depending on the characteristics, applications, etc., and can be, for example, 1.0 mass% or less.

[0049] The propylene polymer composition according to this embodiment preferably has a Hencky strain of 3.21 or more and 4.21 or less at which the elongational viscosity is maximized at a temperature at which the ratio of the melting area at the melting peak in a differential scanning calorimetry (DSC) measurement described later is 94%.

[0050] The propylene polymer composition according to the present embodiment can be produced by mixing the propylene polymer (A), the propylene polymer (B), a β-crystal nucleating agent, and other components as appropriate, and then generally melt-kneading the mixture.

[0051] The melt-kneading can be carried out using known methods and devices. For example, the above materials are premixed using a mixing device such as a Henschel mixer, a ribbon blender, or a tumble mixer, and then melt-kneaded. In addition, a method is exemplified in which a homogeneous mixture is obtained by continuously supplying each of the above materials at a constant ratio using a constant-rate feeder, and then the mixture is melt-kneaded using a single-screw or twin-screw or more extruder, a Banbury mixer, a roll-type kneader, or the like. The temperature during melt-kneading is not particularly limited, but the temperature of the mixture (internal temperature) is preferably 190°C or higher and 320°C or lower, more preferably 210°C or higher and 280°C or lower.

[0052] In another embodiment, the propylene polymer composition according to the present embodiment has a Hencky strain of 3.21 or more and 4.21 or less at which the elongational viscosity is maximized at a temperature at which the ratio of the melting area at the melting peak measured by differential scanning calorimetry (DSC) is 94%.

[0053] A resin sheet made of a propylene-based polymer composition has improved rigidity after secondary processing due to the orientation of molecular chains in the sheet during secondary processing. In order to exhibit a high Young's modulus after secondary processing, it is necessary to strongly orient the molecular chains, and for this purpose, it is desirable that there are many fixed points due to entanglement of molecular chains in the molten part and crystals in the semi-molten state. When the "Hencky strain at which the elongational viscosity is maximized at the temperature at which the ratio of the melting area at the melting peak in differential scanning calorimetry (DSC) measurement is 94%" of the composition constituting the resin sheet is in the above-mentioned range, the molecular chains are well oriented after secondary processing, and the sheet exhibits a high Young's modulus.

[0054] More specifically, if the "Hencky strain at which the extensional viscosity is maximized at the temperature at which the melting area ratio at the melting peak in differential scanning calorimetry (DSC) measurement is 94%" is 3.21 or more, it indicates that the total number of fixed points due to entanglement of molecular chains in the molten part and crystals is large, and a molded product with excellent Young's modulus after secondary processing is obtained. Also, if the "Hencky strain at which the extensional viscosity is maximized at the temperature at which the melting area ratio at the melting peak in differential scanning calorimetry (DSC) measurement is 94%" is 4.21 or less, the total number of fixed points due to entanglement of molecular chains in the molten part and crystals is not excessive, and a molded product with excellent secondary processability is obtained.

[0055] The Hencky strain at which the elongational viscosity is maximized at a temperature at which the ratio of the melting area at the melting peak measured by differential scanning calorimetry (DSC) is 94% is preferably 3.41 or more and 4.21 or less, and more preferably 3.61 or more and 4.21 or less, from the viewpoint of obtaining a molded product having an excellent Young's modulus after secondary processing.

[0056] The Hencky strain at which the extensional viscosity becomes maximum at a temperature at which the ratio of the melting area at the melting peak measured by differential scanning calorimetry (DSC) becomes 94% is determined by the following method.

[0057] (94% melting temperature (unit: ℃)) The 94% melting temperature T94 is measured by differential scanning calorimetry (DSC). The pellets are preheated at 190°C for 5 minutes using a heat press, pressurized at 5MPa and 190°C for 5 minutes, and cooled at 25°C to 27°C for 5 minutes to prepare a pressed sheet with a thickness of 0.2 mm. A sample of 5 mg of the pressed sheet is sealed in an aluminum pan, and using a TA Instruments DSC D250 or TA Instruments DSC Q2000, the temperature is raised to 180°C under a nitrogen atmosphere (first heating), held at 180°C for 3 minutes, cooled from 180°C to 100°C at 20°C / min, and heated from 100°C to 230°C at 20°C / min (second heating). TA Universal Analysis (TA Instruments) is used as the analysis software. In the melting endothermic curve obtained by the second temperature rise, a linear baseline is set in the range of 110 to 182°C, the area S_all of the region enclosed by the obtained baseline and the melting endothermic curve is calculated, and the temperature at which the ratio of the area S integrated from 110°C to the high temperature side to S_all is 94% is calculated as T94. At T94, S / S_all = 0.94.

[0058] (Hencky strain at which the extensional viscosity is maximized at T94) The pellets are preheated at 190°C for 5 minutes using a heat press, pressurized at 190°C for 5 minutes under a pressure of 5MPa, and cooled at 25°C to 27°C for 5 minutes to produce a press sheet with a thickness of 0.5 mm. The obtained press sheet is punched out to a width of 10 mm and a length of 18 mm to produce a test piece for measurement. A strain-controlled rotational viscometer ARES-G2 (manufactured by TA Instruments) is used to measure the extensional viscosity. An extensional jig is used in the device, and the jig alone is preheated to a temperature of 180°C for about 30 minutes. The test piece is attached to the heated jig and left for about 3 minutes, cooled from 180°C to 100°C ± 3°C in 111 seconds (temperature drop i), heated from 100°C ± 3°C to T94 (heat rise i), left for about 3 minutes, and measured at a Hencky strain rate of 0.1 s -1 The specimen was stretched at a Hencky strain of 0.04 (measurement i), left for 1 minute, and then subjected to a Hencky strain rate of 1.0 s -1The extensional viscosity is measured (measurement ii). In the range of Hencky strain 1.0 to 4.25 on the extensional viscosity-Hencky strain curve obtained in measurement ii, the Hencky strain εmax at which the extensional viscosity is at its maximum value is calculated. εmax is calculated by averaging the three values ​​excluding the maximum and minimum values, which are measured five times.

[0059] The Hencky strain at which the extensional viscosity is maximized at the temperature where the melting area ratio in the melting peak measured by differential scanning calorimetry (DSC) is 94% can be changed by changing the branch structure or crystal structure in the composition. For example, the average shrinkage factor (g' ave ) is less than 1, preferably 0.95 or less, more preferably 0.8 or less, and even more preferably 0.7 or less, and contains 0.1% by mass to 30% by mass, preferably 0.5% by mass to 10% by mass, more preferably 1% by mass to 5% by mass, and even more preferably 3% by mass to 5% by mass of a component having a branched structure with a die swell ratio SR of 1.5 or more, preferably 2.0 or more, and more preferably 2.5 or more, and contains 0.1% by mass to 99% by mass, preferably 1% by mass to 50% by mass, more preferably 5% by mass to 40% by mass, and even more preferably 10% by mass to 30% by mass of a crystal nucleating agent for finely dispersing crystals at 1 ppm or more, preferably 3 ppm or more, and more preferably 5 ppm or more, etc., thereby controlling the "Hencky strain at which the elongational viscosity is maximized at a temperature at which the proportion of the melting area in the melting peak measured by differential scanning calorimetry (DSC) is 94%". The preferred range of the amount of each component is the average shrinkage factor (g' ave ) and the die swell ratio SR, and it is advisable to select an appropriate value. It is not necessary to include all of these components, but it is advisable to combine them appropriately.

[0060] In one and another aspects of the propylene polymer composition according to the present embodiment, the strain hardening coefficient at 165° C. in the propylene polymer composition for a resin sheet is preferably 1.3 or more.

[0061] A resin sheet made of a propylene-based polymer composition exhibits higher rigidity after secondary processing as the degree of elongation of the molecular chains of the amorphous portion increases when a small deformation is applied. When the strain hardening at 165°C of the composition constituting the resin sheet is in the above range, the degree of elongation of the molecular chains of the amorphous portion increases when a small deformation is applied to the resin sheet, and the resin sheet exhibits a high Young's modulus after secondary processing. That is, when the strain hardening at 165°C is 1.3 or more, the degree of elongation of the molecular chains of the amorphous portion increases when a small deformation is applied, and a molded product with excellent Young's modulus is obtained after secondary processing.

[0062] From the viewpoint of obtaining a molded product having an excellent Young's modulus after secondary processing, the strain hardening at 165° C. is preferably 1.33 to 3.00, more preferably 1.35 to 3.00. When the strain hardening at 165° C. is 3.00 or less, the molecular chains of the amorphous part do not elongate too much when a small deformation is applied, and a molded product having excellent secondary processability is obtained.

[0063] The strain hardening at 165° C. is determined by the following method.

[0064] The pellets are preheated at 190°C for 5 minutes using a heat press, pressurized at 190°C for 5 minutes at a pressure of 5MPa, and cooled at 25°C to 27°C for 5 minutes to produce a press sheet with a thickness of 0.5 mm. The obtained press sheet is punched out to a width of 10 mm and a length of 18 mm to produce a test piece for measurement. A strain-controlled rotational viscometer ARES-G2 (manufactured by TA Instruments) is used to measure the extensional viscosity. An extension jig is used for the device, and the jig alone is preheated to a temperature of 180°C for about 30 minutes. The test piece is attached to the heated jig and left for about 3 minutes, cooled from 180°C to 100°C ± 4°C in 112 seconds, heated from 100°C ± 4°C to 165°C in 147 seconds, left for about 3 minutes, and measured at a Hencky strain rate of 0.1 s -1 0.05 Hencky strain, 1 min elongation, 0.1 s Hencky strain rate -1 and 1.0s -1 The extensional viscosity is measured at 1.0 s. The measurement is performed twice for each Hencky strain rate. -1Extensional viscosity η measured at 1.0s -1 (t) is the Hencky strain rate of 0.1 s -1 Extensional viscosity η measured at 0.1s -1 The value divided by (t) is α=η1.0s -1 (t) / η0.1s -1 Calculate the natural logarithm lnα of (t), and calculate the slope Δlnα / Δt of lnα in the extension time range of 1.5 seconds to 2.0 seconds to obtain SH165. SH165 is calculated by dividing the η0.1s -1 (t) and η1.0s measured twice -1 The average of the four points calculated from the combination of (t) shall be taken as the score.

[0065] The strain hardening at 165°C can be varied by changing the branching or crystal structure of the composition. For example, the average shrinkage factor (g' ave The "strain hardening at 165 ° C." can be controlled within a preferred range by including 0.1% by mass or more and 30% by mass or less, preferably 0.5% by mass or more and 10% by mass or less, more preferably 1% by mass or more and 5% by mass or less, and even more preferably 3% by mass or more and 5% by mass or less of a component having a branched structure with a die swell ratio SR of 1.5 or more, preferably 2.0 or more, and even more preferably 2.5 or more of a long-term relaxation component, and including 0.1% by mass or more and 99% by mass or less, preferably 1% by mass or more and 50% by mass or less, more preferably 5% by mass or more and 40% by mass or less, and even more preferably 10% by mass or more and 30% by mass or less of a crystal nucleating agent for finely dispersing crystals, and the like. The preferred range of the amount of each component is the average shrinkage factor (g' ave ) and the die swell ratio SR, and it is advisable to select an appropriate value. It is not necessary to include all of these components, but it is advisable to combine them appropriately.

[0066] [Resin sheet] The resin sheet according to this embodiment is made of the above-mentioned propylene-based polymer composition.

[0067] The resin sheet is set to an appropriate form in consideration of the application, mode of use, etc., and may be, for example, a film or a strip, and may be long or short (sheet-shaped). In consideration of the productivity of secondary processing, etc., the resin sheet is preferably a long sheet. The resin sheet may be a single layer or a multi-layer.

[0068] The thickness (total thickness) of the resin sheet is preferably 50 μm or more, more preferably 300 μm or more, and even more preferably 500 μm or more. The thickness (total thickness) of the resin sheet is preferably 1500 μm or less, more preferably 1200 μm or less, and even more preferably 1000 μm or less. A resin sheet having a thickness in the above range is particularly suitable for use in a food container.

[0069] The method for producing the resin sheet according to the present embodiment is not particularly limited, but a production method including the following steps (1) and (2), that is, a so-called (extrusion) sheet molding method, is preferred. Step (1): A step of melt-extruding the propylene polymer composition according to the present embodiment. Step (2): The extruded propylene polymer composition is cooled at a temperature of 30 to 90° C. and extruded at a rate of 1000 μm. The speed is 1.2 to 30.0 m / min, and the thickness is 50 to 1500 μm. The process of forming into sheets

[0070] <Process (1)> In step (1), the propylene polymer composition is melt-kneaded during melt extrusion. The method and conditions of melt kneading are not particularly limited, and the method and conditions of melt kneading in the preparation of the propylene polymer composition described above can be applied. When carrying out step (1), the propylene polymer composition can be prepared during melt kneading in melt extrusion without preparing the propylene polymer composition in advance (preparation of the composition and melting are carried out simultaneously). When using a propylene polymer composition prepared in advance, it is preferable from the viewpoint of productivity to prepare the propylene polymer composition and melt it in melt extrusion continuously.

[0071] The melt extrusion in step (1) is carried out, for example, by extruding the melt-kneaded propylene polymer composition through a T-die using an extruder or the like. The extrusion rate is not particularly limited and is appropriately set depending on the thickness of the resin sheet, the molding speed, and the like. For example, it can be 50 to 2000 kg / hour. The extrusion temperature can be set in the same temperature range as the above-mentioned melt-kneading temperature, and can be, for example, 200 to 300°C. The extrusion temperature is the temperature of the T-die itself.

[0072] <Process (2)> Next, in step (2), the extruded propylene-based polymer composition is formed into a sheet having a thickness of 50 to 1500 μm under the conditions of a cooling temperature of 30 to 90° C. and a forming speed of 1.2 to 30.0 m / min. Specifically, the propylene-based polymer composition extruded from the T-die is cooled and solidified while being wound around a chill roll, and can be formed into a film (formed) with a predetermined thickness. In this step, the extruded propylene-based polymer composition is usually transported between adjacent chill rolls using a plurality of chill rolls arranged in parallel at a predetermined interval, and formed into a sheet. The plurality of chill rolls are called the first chill roll, the second chill roll, ..., the nth chill roll (n is the number of chill rolls) from the upstream side to the downstream side in the transport direction. The surface of the chill roll is usually mirror-finished.

[0073] In step (2), the cooling temperature is set to 30 to 90°C, and the forming speed (also referred to as the conveying speed or winding speed) is set to 1.2 to 30.0 m / min. The cooling temperature refers to the temperature set on the chill roll, and it is preferable that all chill rolls are set to the same temperature. The chill rolls whose temperatures are set may all be set to the same temperature, or may be set to different temperatures. The cooling temperature is preferably 30 to 90°C, and more preferably 40 to 80°C. The forming speed is preferably 1.2 to 30.0 m / min, and more preferably 1.5 to 20.0 m / min.

[0074] <Other processes> The method for producing a resin sheet of the present invention may include other steps in addition to the above steps (1) and (2).

[0075] The resin sheet according to the present embodiment is preferably used as a material for molded articles such as containers produced by a thermoforming method as a secondary processing, and examples of such applications include packaging applications for food, textiles, miscellaneous goods, etc. In particular, the resin sheet is preferably used as a material for food containers (food trays) that utilize the properties of the polypropylene-based polymer composition, and particularly as a material for rice containers.

[0076] [container] The container according to the present embodiment includes the above-mentioned resin sheet. The container according to the present embodiment is a container obtained by subjecting the above-mentioned resin sheet to secondary processing (thermoforming). The container is set to an appropriate shape and size depending on the specific use, application form, etc. The container is preferably used as a food container, more preferably as a rice container.

[0077] The container of this embodiment is a container with excellent heat and cold resistance, having heat resistance sufficient to withstand microwave heating and cold resistance suitable for low-temperature storage in a freezer, etc., and is also suitable for the transportation process during container manufacturing.

[0078] The method of secondary processing (thermoforming) for forming the container is not particularly limited, and any known method can be applied, and the processing conditions (thermoforming conditions) are also appropriately set.

[0079] The present invention includes the following aspects. [1] A propylene-based polymer (A) containing 90% by mass or more of structural units derived from propylene and having no long chain branched structure; A propylene-based polymer (B) having a long chain branched structure, A β crystal nucleating agent, With respect to the total content of the propylene-based polymer (A) and the content of the propylene-based polymer (B) being 100% by mass, The content of the propylene polymer (A) is 70% by mass or more, The content of the propylene polymer (B) is 0.1% by mass or more and 30% by mass or less, The propylene polymer composition for resin sheets has a content of the β-crystal nucleating agent of 1 ppm or more and 10,000 ppm or less. [2] A propylene-based polymer composition for resin sheets, having a Hencky strain of 3.21 or more and 4.21 or less at which the elongational viscosity is maximized at a temperature at which the ratio of the melting area at the melting peak is 94% as measured by differential scanning calorimetry (DSC). [3] The propylene polymer composition for a resin sheet according to the above [1] or [2], which has a strain hardening coefficient at 165°C of 1.3 or more. [4] The propylene polymer composition for resin sheets according to the above [1] or [3], wherein the propylene polymer (A) has a melt flow rate of 0.01 g / 10 min or more and 30 g / 10 min or less. [5] The propylene-based polymer composition for resin sheets according to any one of the above [1], [3], and [4], wherein the propylene-based polymer (B) has a melt flow rate of 0.01 g / 10 min or more and 30 g / 10 min or less. [6] Average shrinkage factor g' of the propylene polymer (B) ave The propylene polymer composition for resin sheets according to any one of the above [1], and [3] to [5], wherein is 0.10 or more and 0.95 or less. [7] The propylene-based polymer composition for resin sheets according to any one of the above [1], and [3] to [6], wherein the content of the propylene-based polymer (B) is 0.1 mass% or more and 30 mass% or less, relative to 100 mass% of the total content of the propylene-based polymer (A) and the propylene-based polymer (B). [8] A resin sheet comprising the propylene polymer composition according to any one of the above [1] to [7]. [9] The resin sheet according to [8] above, wherein the resin sheet has a thickness of 50 μm or more.

[10] A container provided with the resin sheet described in [8] or [9] above. EXAMPLES

[0080] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The measured values ​​of each item in the detailed description of the invention, examples, and comparative examples were measured by the following methods.

[0081] (1) Average contraction factor (g′ ave ) The propylene-based polymer was dissolved in o-dichlorobenzene as a solvent at a concentration of 20 mg / 10 ml, and the measurement was performed using a GPC device equipped with a viscosity detector, a light scattering detector, and an RI detector. For the calibration of the light scattering detector (LS) and the viscosity detector (VISC) and for the correction of the delay volume between the detectors, NIST polystyrene standard substance F10 (weight average molecular weight Mw 96400, polydispersity 1.01) was used at a solution concentration of 2 mg / ml. The refractive index increment (dn / dc) of the propylene-based polymer in o-dichlorobenzene was set to 0.079 ml / g. The dn / dc of the polystyrene standard substance was set to 0.079 ml / g. The absolute molecular weight and intrinsic viscosity ([η]; unit is dl / g) were calculated from the data of each detector using Malvern's data processing software OmniSEC (version 4.7) and the calculation was performed with reference to the literature "Size Exclusion Chromatography Springer (1999)". The refractive index increment is the rate of change of the refractive index relative to the change in concentration. The shrinkage factor g' = [η] / [η]0 was calculated from the intrinsic viscosity [η] at any absolute molecular weight M obtained by the above measurement and the intrinsic viscosity [η]0 of the linear polymer at any absolute molecular weight M obtained by calculation. Here, the intrinsic viscosity [η]0 of the linear polymer was calculated using the following formula. [η]0 = 3.44 × 10 -4 ×M 0.669 (dl / g) In the elution time corresponding to logM of 5.0 to 6.0, the elution time is divided into m equal intervals, and the average shrinkage factor g′ is calculated using the following formula: ave was calculated.

[0082]

number

[0083] Here, g′ i is the shrinkage factor g′ in the i-th logM of the elution time divided into m equal intervals for the elution time corresponding to logM = 5.0 to 6.0, and w i is the normalized weight fraction at the i-th logM among m intervals equally spaced with respect to the elution time corresponding to logM = 5.0 to 6.0. The number m of arbitrarily divided sections is determined by dividing the elution time corresponding to logM=5.0-6.0 by the data acquisition interval.

[0084] <Measurement conditions> GPC equipment: HLC-8121GPC / HT (Tosoh Corporation) Light scattering detector: PD2040 (Precision Detectors) Laser light source: Wavelength 685nm Viscosity detector: H502 (Viscotek) GPC column: PLgel MIXED-A LS 300 x 7.5 mm (Agilent) x 3 Sample solution concentration: 1mg / mL ·Injection volume: 300μL ·Measurement temperature: 145℃ Dissolution conditions: Stir at 145℃ for 2 hours Solvent and mobile phase: orthodichlorobenzene (Wako special grade) containing 0.1% by mass of dibutylhydroxytoluene ·Mobile phase flow rate: 1.0mL / min Measurement time: Approximately 1 hour Molecular weight standard: Standard polystyrene Data capture interval: 1.74 seconds

[0085] (2) 94% melting temperature (unit: °C) The 94% melting temperature T94 was measured by differential scanning calorimetry (DSC). The pellets were preheated at 190°C for 5 minutes using a heat press, pressurized at 5MPa and 190°C for 5 minutes, and cooled at 25°C to 27°C for 5 minutes to produce a pressed sheet with a thickness of 0.2 mm. A sample of 5 mg of the pressed sheet was sealed in an aluminum pan, and the sample was heated to 180°C (first heating) under a nitrogen atmosphere using a TA Instruments DSC D250 or TA Instruments DSC Q2000, held at 180°C for 3 minutes, cooled from 180°C to 100°C at 20°C / min, and heated from 100°C to 230°C at 20°C / min (second heating). TA Universal Analysis (TA Instruments) was used as the analysis software. In the melting endothermic curve obtained by the second heating, a linear baseline was set in the range of 110 to 182°C, and the area S_all of the region enclosed by the obtained baseline and the melting endothermic curve was calculated. The temperature at which the ratio of the area S integrated from 110°C to the high temperature side to S_all was 94% was calculated as T94. At T94, S / S_all = 0.94.

[0086] (3) Hencky strain at which the elongational viscosity is maximized at T94 The pellets were preheated at 190°C for 5 minutes using a heat press, pressurized at 5MPa and 190°C for 5 minutes, and cooled at 25°C to 27°C for 5 minutes to produce a press sheet with a thickness of 0.5 mm. The obtained press sheet was punched out to a width of 10 mm and a length of 18 mm to produce a test piece for measurement. A strain-controlled rotational viscometer ARES-G2 (manufactured by TA Instruments) was used to measure the extensional viscosity. An extension jig was used in the device, and the jig alone was preheated at 180°C for about 30 minutes. The test piece was attached to the heated jig and left for about 3 minutes, cooled from 180°C to 100°C ± 3°C in 111 seconds (temperature drop i), heated from 100°C ± 3°C to T94 (heat rise i), left for about 3 minutes, and measured at a Hencky strain rate of 0.1 s -1 The specimen was stretched at a Hencky strain of 0.04 (measurement i), left for 1 minute, and then subjected to a Hencky strain rate of 1.0 s -1The extensional viscosity was measured (measurement ii). In the range of Hencky strain 1.0 to 4.25 of the extensional viscosity-Hencky strain curve obtained in measurement ii, the Hencky strain εmax was calculated when the extensional viscosity was at its maximum value. εmax was calculated as the average value of three points excluding the maximum and minimum values, which were measured five times. The time required for temperature rise i is described in the following paragraph.

[0087] (4) Strain hardening at 165℃ The pellets were preheated at 190°C for 5 minutes using a heat press, pressurized at 5MPa and 190°C for 5 minutes, and cooled at 25°C to 27°C for 5 minutes to produce a press sheet with a thickness of 0.5 mm. The obtained press sheet was punched out to a width of 10 mm and a length of 18 mm to produce a test piece for measurement. A strain-controlled rotational viscometer ARES-G2 (manufactured by TA Instruments) was used to measure the extensional viscosity. An extension jig was used for the device, and the jig alone was preheated at 180°C for about 30 minutes. The test piece was attached to the heated jig and left for about 3 minutes, cooled from 180°C to 100°C ± 4°C in 112 seconds, heated from 100°C ± 4°C to 165°C in 147 seconds, left for about 3 minutes, and measured at a Hencky strain rate of 0.1 s -1 0.05 Hencky strain, 1 min elongation, 0.1 s Hencky strain rate -1 and 1.0s -1 The extensional viscosity was measured at 1.0 s. The measurements were carried out twice for each Hencky strain rate. -1 Extensional viscosity η measured at 1.0s -1 (t) is the Hencky strain rate of 0.1 s -1 Extensional viscosity η measured at 0.1s -1 The value divided by (t) is α=η1.0s -1 (t) / η0.1s -1 The natural logarithm lnα of (t) was calculated, and the slope of lnα, Δlnα / Δt, was calculated for the extension time range of 1.5 to 2.0 seconds, and used as SH165. SH165 was calculated by dividing the η0.1s -1 (t) and η1.0s measured twice -1 The average value of the four points calculated from the combination of (t) was used.

[0088] (5) Young's modulus (unit: GPa) A uniaxially stretched sheet of 120 mm x 20 mm was taken so that the long side direction (120 mm) coincided with the measurement direction (MD direction). A tensile test was performed using an Autograph AGS10KNG (Shimadzu Corporation) at a grip distance of 60 mm and a tensile speed of 5 mm / min under an atmosphere of 23°C and 50% humidity, and Young's modulus (MD direction) was measured from the slope between the points where the stress was 10 N and the points where the stress was 30 N in the stress-strain curve.

[0089] (6) Melt flow rate (MFR, unit: g / 10 min) The measurement was performed according to Method A specified in JIS K7210-1 at a temperature of 230°C and a load of 2.16 kg.

[0090] (7) Die swell ratio (SR, unit: -) The die swell ratio of the propylene-based polymer composition was calculated by measuring the cross-sectional diameter of the extrudate of the propylene-based polymer composition obtained when measuring the MFR of the propylene-based polymer composition at a temperature of 230°C and a load of 2.16 kg according to Method A specified in JIS K7210-1:2014, and using the following formula: Note that the cross-section of the extrudate of the propylene-based polymer composition means a cross-section perpendicular to the extrusion direction, and when the cross-section is not a perfect circle, it means the average value of the maximum and minimum diameters of the cross-section. SR=Dp / Dh (In the formula, SR indicates the die swelling ratio of the propylene-based polymer composition. Dh represents the diameter of the orifice in the cross section of the extrudate of the propylene-based polymer composition. Dp represents the cross-sectional diameter of the extrudate of the propylene-based polymer composition.

[0091] The components used in the examples and comparative examples are as follows.

[0092] <Propylene-Based Polymer Composition 1> Propylene was polymerized by gas-phase polymerization using a Ziegler-Natta catalyst, triethylaluminum as a cocatalyst, and cyclohexylethyldimethoxysilane as an external donor under an effective hydrogen concentration of 0.29 mol% in the gas phase. Propylene homopolymer A-1 (MFR = 2.3 g / 10 min, SR = 1.2, average shrinkage factor g′ ave = 1.0) was obtained. 100 parts by mass of the obtained propylene homopolymer A-1 was mixed with 0.01 parts by mass of DHT-4C (neutralizer, manufactured by Kyowa Chemical Industry Co., Ltd.), 0.05 parts by mass of IRGANOX1010 (antioxidant, manufactured by BASF Japan Ltd.), and 0.1 parts by mass of Sumilizer GP (antioxidant, manufactured by Sumitomo Chemical Co., Ltd.), and then melt extrusion was performed to obtain a propylene polymer composition 1.

[0093] <Propylene-Based Polymer Composition 2> Propylene was polymerized by gas-phase polymerization using a Ziegler-Natta catalyst, triethylaluminum as a cocatalyst, and cyclohexylethyldimethoxysilane as an external donor under an effective hydrogen concentration of 0.98 mol% in the gas phase, to obtain propylene homopolymer A-2 (MFR = 7.7 g / 10 min, SR = 1.2, average shrinkage factor g′ ave =1.0) was obtained. 0.15 parts by mass of IRGANOX1010 (antioxidant, manufactured by BASF Japan Ltd.) was blended with 100 parts by mass of the obtained propylene homopolymer A-2, and then melt extrusion was performed to obtain a propylene polymer composition 2.

[0094] <Propylene polymer 3-1> A commercially available polypropylene resin (WB135HMS) was used. (Characteristics of commercial products) WB135HMS (trade name): Propylene homopolymer manufactured by Borealis (MFR = 2.1 g / 10 min, SR = 2.8, average shrinkage factor g' ave =0.81)

[0095] <Propylene polymer 3-2> A commercially available polypropylene resin (WB140HMS) was used. (Characteristics of commercial products) WB140HMS (trade name): Propylene homopolymer manufactured by Borealis (MFR = 1.4 g / 10 min, SR = 4.0, average shrinkage factor g' ave =0.78)

[0096] <Propylene polymer masterbatch 4-1> Propylene homopolymer 3-1 (50 parts by mass) was mixed with propylene polymer composition 1 (50 parts by mass), and then melt extrusion was carried out to obtain pellet-shaped propylene polymer master batch 4-1.

[0097] <Propylene-Based Polymer Composition Masterbatch 4-2> The propylene homopolymer 3-2 (50 parts by mass) was blended with the propylene polymer composition 1 (50 parts by mass), and then melt extrusion was carried out to obtain a pellet-shaped propylene polymer master batch 4-2.

[0098] <β crystal nucleating agent masterbatch> 95 parts by mass of propylene homopolymer A-2 was mixed with 5 parts by mass of NU-100 (β crystal nucleating agent, manufactured by New Japan Chemical Industry Co., Ltd.), 0.01 parts by mass of DHT-4C (neutralizing agent, manufactured by Kyowa Chemical Industry Co., Ltd.), 0.05 parts by mass of IRGANOX1010 (antioxidant, manufactured by BASF Japan Ltd.), and 0.1 parts by mass of Sumilizer GP (antioxidant, manufactured by Sumitomo Chemical Co., Ltd.), and the mixture was melt-extruded to obtain a pellet-shaped β crystal nucleating agent master batch.

[0099] <α crystal nucleating agent masterbatch> 95 parts by mass of propylene homopolymer A-1 was blended with 5 parts by mass of NX8000J (α-crystal nucleating agent, manufactured by Milliken), 0.01 part by mass of DHT-4C (neutralizing agent, manufactured by Kyowa Chemical Industry Co., Ltd.), 0.05 part by mass of IRGANOX1010 (antioxidant, manufactured by BASF Japan Ltd.), and 0.1 part by mass of Sumilizer GP (antioxidant, manufactured by Sumitomo Chemical Co., Ltd.), and the blend was then melt-extruded to obtain a pellet-shaped α-crystal nucleating agent master batch.

[0100] <Example 1: Preparation of propylene polymer composition 11 and uniaxially stretched sheet 11> Propylene-based polymer composition 1 (97 parts by mass) was mixed with propylene-based polymer master batch 4-1 (2 parts by mass) and β-crystal nucleating agent master batch (1 part by mass), and then the mixture was heated and melted at a resin temperature of 260°C using a T-die film-forming machine equipped with an extruder having a screw diameter of 65 mmφ, and extruded onto a cooling roll at 30°C to obtain an unstretched sheet made of propylene-based polymer composition 11. The unstretched sheet obtained was stretched 8 times in the MD direction using a stretching roll heated to 142°C (roll temperature), to obtain a uniaxially stretched sheet 11. The composition of the unstretched sheet made of propylene-based polymer composition 11 is shown in Table 1 below. The physical property values ​​of the unstretched sheet made of propylene-based polymer composition 11 and the uniaxially stretched sheet 11 are shown in Table 2 below. T94 was 165°C, and in the temperature rise i when measuring εmax, the temperature was raised from 100°C±3°C to 165°C in 168 seconds.

[0101] <Example 2: Preparation of propylene-based polymer composition 12 and uniaxially stretched sheet 12> Propylene-based polymer composition 1 (89 parts by mass) was mixed with propylene-based polymer master batch 4-1 (10 parts by mass) and β-crystal nucleating agent master batch (1 part by mass), and then the mixture was heated and melted at a resin temperature of 260°C using a T-die film-forming machine equipped with an extruder having a screw diameter of 65 mmφ, and extruded onto a cooling roll at 30°C to obtain an unstretched sheet made of propylene-based polymer composition 12. The unstretched sheet obtained was stretched 8 times in the MD direction using a stretching roll heated to 142°C (roll temperature), to obtain a uniaxially stretched sheet 12. The composition of the unstretched sheet made of propylene-based polymer composition 12 is shown in Table 1 below. The physical properties of the unstretched sheet made of propylene-based polymer composition 12 and the uniaxially stretched sheet 12 are shown in Table 2 below. T94 was 165°C, and in the temperature rise i when measuring εmax, the temperature was raised from 100°C±3°C to 165°C in 168 seconds.

[0102] <Example 3: Preparation of propylene polymer composition 13 and uniaxially stretched sheet 13> Propylene-based polymer composition 1 (93 parts by mass) was mixed with propylene-based polymer master batch 4-2 (6 parts by mass) and β-crystal nucleating agent master batch (1 part by mass), and then the mixture was heated and melted at a resin temperature of 260°C using a T-die film-forming machine equipped with an extruder having a screw diameter of 65 mmφ, and extruded onto a cooling roll at 30°C to obtain an unstretched sheet made of propylene-based polymer composition 13. The unstretched sheet obtained was stretched 8 times in the MD direction using a stretching roll heated to 142°C (roll temperature), to obtain a uniaxially stretched sheet 13. The composition of the unstretched sheet made of propylene-based polymer composition 13 is shown in Table 1 below. The physical property values ​​of the unstretched sheet made of propylene-based polymer composition 13 and the uniaxially stretched sheet 13 are shown in Table 2 below. T94 was 166°C, and in the temperature rise i when measuring εmax, the temperature was raised from 100°C±3°C to 166°C in 173 seconds.

[0103] <Example 4: Preparation of propylene polymer composition 14 and uniaxially stretched sheet 14> Propylene-based polymer composition 1 (89 parts by mass) was mixed with propylene-based polymer master batch 4-2 (6 parts by mass) and β-crystal nucleating agent master batch (5 parts by mass), and then the mixture was heated and melted at a resin temperature of 260°C using a T-die film-forming machine equipped with an extruder having a screw diameter of 65 mmφ, and extruded onto a cooling roll at 30°C to obtain an unstretched sheet made of propylene-based polymer composition 14. The unstretched sheet obtained was stretched 8 times in the MD direction using a stretching roll heated to 142°C (roll temperature), to obtain a uniaxially stretched sheet 14. The composition of the unstretched sheet made of propylene-based polymer composition 14 is shown in Table 1 below. The physical properties of the unstretched sheet made of propylene-based polymer composition 14 and the uniaxially stretched sheet 14 are shown in Table 2 below. T94 was 167°C, and in the temperature rise i when measuring εmax, the temperature was raised from 100°C±3°C to 167°C in 171 seconds.

[0104] <Comparative Example 1: Preparation of Propylene-Based Polymer Composition 21 and Uniaxially Stretched Sheet 21> Propylene-based polymer composition 1 (80 parts by mass) was mixed with propylene-based polymer master batch 4-1 (20 parts by mass), and then the mixture was heated and melted at a resin temperature of 260°C using a T-die film-forming machine equipped with an extruder having a screw diameter of 65 mmφ, and extruded onto a cooling roll at 30°C to obtain an unstretched sheet made of propylene-based polymer composition 21. The unstretched sheet obtained was stretched 8 times in the MD direction using a stretching roll heated to 142°C (roll temperature), to obtain a uniaxially stretched sheet 21. The composition of the unstretched sheet made of propylene-based polymer composition 21 is shown in Table 1 below. The physical property values ​​of the unstretched sheet made of propylene-based polymer composition 21 and the uniaxially stretched sheet 21 are shown in Table 2 below. T94 was 166°C, and in the temperature rise i when measuring εmax, the temperature was raised from 100°C±3°C to 166°C in 173 seconds.

[0105] <Comparative Example 2: Preparation of Propylene-Based Polymer Composition 22 and Uniaxially Stretched Sheet 22> Propylene-based polymer composition 1 (98 parts by mass) was mixed with α-crystal nucleating agent master batch (2 parts by mass), and then the mixture was heated and melted at a resin temperature of 260°C using a T-die film-forming machine equipped with an extruder having a screw diameter of 65 mmφ, and extruded onto a cooling roll at 30°C to obtain an unstretched sheet made of propylene-based polymer composition 22. The unstretched sheet obtained was stretched 8 times in the MD direction using a stretching roll heated to 142°C (roll temperature), to obtain a uniaxially stretched sheet 22. The composition of the unstretched sheet made of propylene-based polymer composition 22 is shown in Table 1 below. The physical properties of the unstretched sheet made of propylene-based polymer composition 22 and the uniaxially stretched sheet 22 are shown in Table 2 below. T94 was 166°C, and in the temperature rise i when measuring εmax, the temperature was raised from 100°C±3°C to 166°C in 173 seconds.

[0106] [Table 1]

[0107] [Table 2]

[0108] As can be seen from Table 2, the uniaxially stretched sheets using the propylene-based polymer compositions of the Examples which satisfy all the constituent requirements of the present invention have a higher Young's modulus than the uniaxially stretched sheets of the Comparative Examples, and therefore have improved rigidity. That is, the present invention can provide a propylene-based polymer composition for resin sheets which can provide a sheet with relatively excellent rigidity.

Claims

1. A propylene-based polymer (A) containing 90 mass% or more of structural units derived from propylene and having no long chain branched structure; A propylene-based polymer (B) having a long chain branched structure, A β crystal nucleating agent, With respect to the total content of the propylene-based polymer (A) and the content of the propylene-based polymer (B) being 100% by mass, The content of the propylene polymer (A) is 70% by mass or more, The content of the propylene polymer (B) is 0.1% by mass or more and 30% by mass or less, The propylene-based polymer composition for resin sheets has a content of the β-crystal nucleating agent of 1 ppm or more and 10,000 ppm or less.

2. A propylene-based polymer composition for a resin sheet, which has a Hencky strain of 3.21 or more and 4.21 or less at which the extensional viscosity becomes maximum at a temperature at which the ratio of the melting area at a melting peak measured by differential scanning calorimetry (DSC) is 94%.

3. The propylene polymer composition for a resin sheet according to claim 1, which has a strain hardening coefficient at 165°C of 1.3 or more.

4. The propylene polymer composition for a resin sheet according to claim 1, wherein the propylene polymer (A) has a melt flow rate of 0.01 g / 10 min or more and 30 g / 10 min or less.

5. The propylene polymer composition for a resin sheet according to claim 1, wherein the propylene polymer (B) has a melt flow rate of 0.01 g / 10 min or more and 30 g / 10 min or less.

6. The average shrinkage factor g' of the propylene polymer (B) ａｖｅ The propylene polymer composition for a resin sheet according to claim 1, wherein the propylene polymer composition for a resin sheet according to claim 1 has a tensile strength of 0.10 or more and 0.95 or less.

7. 2. The propylene-based polymer composition for a resin sheet according to claim 1, wherein a content of the propylene-based polymer (B) is 0.1% by mass or more and 10% by mass or less, relative to a total content of the propylene-based polymer (A) and the propylene-based polymer (B) (100% by mass).

8. A resin sheet comprising the propylene-based polymer composition according to any one of claims 1 to 7.

9. The resin sheet according to claim 8 , wherein the resin sheet has a thickness of 50 μm or more.

10. A container comprising the resin sheet according to claim 8.

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