Food-grade propylene resin composition and molded article thereof

Abstract

To provide a propylene-based resin composition for retort-processed food containers that has transparency allowing the contents to be seen. [Solution] A propylene-based resin composition for retort food containers, characterized by containing a propylene-based polymer (A) that satisfies requirements (A1) to (A3), a propylene-based copolymer (B) that satisfies requirements (B1) to (B3), a propylene-based resin (X) that satisfies requirement (X1), and a nucleating agent (C) that satisfies requirement (C1), and satisfying condition (1).

Description

Technical Field

[0001] The present invention relates to a propylene-based resin composition for retort foods and a molded article thereof. Specifically, it relates to a propylene-based resin composition for food containers that has transparency allowing the contents to be viewed and is subjected to retort processing, and a molded article thereof.

Background Art

[0002] Polypropylene has characteristics such as hygiene, high heat resistance, high rigidity, impact resistance, and chemical resistance, and thus has been widely used in many fields conventionally. For example, it is also used for food containers where hygiene and odor are issues.

[0003] Recently, there are concerns about global plastic environmental pollution problems such as the problem of waste plastics flowing into the ocean. In Japan, the Plastic Resources Recycling Promotion Law has been implemented, and 3R+Renewable is being promoted. 3R is Reduce, Reuse, Recycle, to which Renewable, appropriately switching to recycled materials and renewable resources, is added. In terms of Reduce, that is, reducing the amount of use, a propylene-based resin composition that can mold thinner and lighter molded articles is desired in consideration of the above environmental problems.

[0004] On the other hand, by making the thickness thinner, it is possible to reduce the amount of material used and the load on the environment, but there are problems such as molding property problems, a decrease in the product rigidity of the molded article, and a decrease in the impact resistance of the product, making it more likely to crack.

[0005] Furthermore, there is also a demand for materials corresponding to retort foods that can be stored for a long time in terms of food loss and the like. Retort processing refers to foods that are sterilized at high temperature and high pressure of 120°C for 4 minutes or more. Although it varies depending on the product, many have a shelf life of about one year and are considered effective in terms of food loss, and are also foods that are utilized during disasters. As measures for these, technologies such as those in Patent Document 1 and Patent Document 2 have been proposed. On the other hand, retort processing presents problems such as the deformation of the container, the deposition of components on the surface of the container, and significant changes in appearance. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Special table publication No. 2016-528356 (composition) [Patent Document 2] Special Publication No. 2004-519394 (product shape) [Disclosure of the Invention] [Problems that the invention aims to solve]

[0007] The present invention aims to solve these problems and provide a propylene-based resin composition for retort-processed food containers that has transparency allowing the contents to be seen. [Means for solving the problem]

[0008] As a result of diligent research, the inventors have discovered that a propylene resin containing a specific propylene polymer and a specific propylene copolymer in specific proportions, and a propylene resin composition containing a specific nucleating agent in specific amounts, can solve the above problems, and have completed the present invention.

[0009] In other words, the present invention has the following configuration. [1] A propylene-based resin composition for retort food containers, characterized by containing a propylene-based polymer (A) that satisfies the following requirements (A1) to (A3), a propylene-based copolymer (B) that satisfies the following requirements (B1) to (B3), a propylene-based resin (X) that satisfies the following requirement (X1), a nucleating agent (C) that satisfies the following requirement (C1), and satisfying the following condition (1). Requirements (A1) The propylene polymer (A) is a metallocene-based propylene polymer. Requirements (A2) The melt flow rate (MFR: 230°C, 2.16 kg load) of the propylene polymer (A) is in the range of 0.5 to 100 g / 10 min. Requirements (A3) The propylene polymer (A) is at least one selected from the group consisting of propylene homopolymers and propylene-α-olefin random copolymers having an α-olefin content of less than 1% by weight. Requirements (B1) Propylene copolymer (B) is a metallocene-based propylene polymer. Requirements (B2) The melt flow rate (MFR: 230°C, 2.16 kg load) of the propylene copolymer (B) is in the range of 0.5 to 80 g / 10 min. Requirements (B3) The propylene copolymer (B) is a propylene-α-olefin random copolymer with an α-olefin content in the range of 3 to 17% by weight. Requirements (X1) The propylene resin (X) contains 75-98% by weight of a propylene polymer (A) and 2-25% by weight of a propylene copolymer (B) (provided that the total of propylene polymer (A) and propylene copolymer (B) is 100% by weight). Requirements (C1) The nucleating agent (C) is at least one selected from the group consisting of nucleating agents represented by the following formulas (1), (2), and (3). R 1 (CONHR 2 ) a Formula (1) [In formula (1), R 1 R represents a saturated or unsaturated aliphatic polycarboxylic acid residue having 2 to 30 carbon atoms, a saturated or unsaturated alicyclic polycarboxylic acid residue having 4 to 28 carbon atoms, or an aromatic polycarboxylic acid residue having 6 to 18 carbon atoms. 2 [wherein 'a' represents an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, or a cycloalkyl group or cycloalkenyl group having 3 to 46 carbon atoms, and 'a' represents an integer from 2 to 6.] TIFF2026093132000001.tif47152[In formula (2), R 1 is a direct bond, sulfur, an alkylene group or an alkylidene group having 1 to 9 carbon atoms, and R 2 and R 3 are the same or different and each independently is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, M is Na, and n is the valence of M.] TIFF2026093132000002.tif51155[In formula (3), R 1 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R 2 and R 3 are the same or different and each independently represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, M represents a metal atom of Group III or Group IV of the periodic table, and X represents HO- when M represents a metal atom of Group III of the periodic table, and represents O= or (HO)2- when M represents a metal atom of Group IV of the periodic table.] Condition (1) The propylene-based resin composition for retort food containers contains 0.01 to 0.6 parts by weight of a nucleating agent (C) with respect to 100 parts by weight of the propylene-based resin (X). [2] The propylene-based resin composition for retort food containers according to [1], wherein the propylene-based resin (X) further satisfies the following requirement (X2). Requirement (X2) The propylene-based resin (X) is a continuous polymer. [3] A molded product for a retort food container, comprising the propylene-based resin composition for a retort food container according to [1] or [2].

Advantages of the Invention

[0010] According to the present invention, it is possible to provide a propylene-based resin composition for a food container to be retort-treated, which has transparency allowing the contents to be confirmed and is also excellent in impact resistance, rigidity, and heat resistance.

Brief Description of the Drawings

[0011] [Figure 1]This figure shows the amount of elution and the cumulative amount of elution by temperature-reduced elution fractionation (TREF) of propylene-ethylene block copolymer. [Figure 2] Figure 2 is a flow sheet of the continuous horizontal vapor polymerization apparatus used in the example. [Modes for carrying out the invention]

[0012] One embodiment of the present invention is a propylene-based resin composition for retort food containers, characterized by containing a propylene-based polymer (A) (hereinafter sometimes abbreviated as component (A)) that satisfies requirements (A1) to (A3), a propylene-based copolymer (B) (hereinafter sometimes abbreviated as component (B)) that satisfies requirements (B1) to (B3), a propylene-based resin (X) that satisfies requirement (X1), and a nucleating agent (C) (hereinafter sometimes abbreviated as component (C)) that satisfies requirement (C1), and satisfying condition (1) (hereinafter also referred to as "the propylene-based resin composition of the present invention"). The details of each item regarding the propylene-based resin composition of the present invention are described below.

[0013] 1. Propylene resin (X) The propylene resin (X) contained in the propylene resin composition of the present invention contains a propylene polymer (A) that satisfies requirements (A1) to (A3) and a propylene copolymer (B) that satisfies requirements (B1) to (B3).

[0014] (1) Propylene polymer (A) The propylene polymer (A) satisfies the following requirements (A1) to (A3).

[0015] (1-1) Requirements (A1) The propylene polymer (A) is a metallocene-based propylene polymer. Metallocene-based propylene polymers have a narrow molecular weight distribution (so-called Mw / Mn (Q value)) and are polymers with few low molecular weight components. Therefore, because propylene polymer (A) is a metallocene-based propylene polymer, it can suppress bleeding on the surface of molded products after retort processing.

[0016] The metallocene catalyst for producing metallocene-based propylene polymers is a catalyst comprising (i) a transition metal compound of Group 4 of the periodic table containing a ligand having a cyclopentadienyl skeleton (a so-called metallocene compound), (ii) a co-catalyst that can be activated to a stable ionic state by reacting with the metallocene compound, and optionally (iii) an organoaluminum compound. For example, any known catalyst can be used. The metallocene compound is preferably a crosslinked metallocene compound capable of stereoregular polymerization of propylene, and more preferably a crosslinked metallocene compound capable of isoregular polymerization of propylene.

[0017] (i) Examples of metallocene compounds are disclosed in the following publications: Japanese Patent Publication No. 60-35007, Japanese Patent Publication No. 61-130314, Japanese Patent Publication No. 63-295607, Japanese Patent Publication No. 1-275609, Japanese Patent Publication No. 2-41303, Japanese Patent Publication No. 2-131488, Japanese Patent Publication No. 2-76887, Japanese Patent Publication No. 3-163088, Japanese Patent Publication No. 4-300887, Japanese Patent Publication No. 4-211694, Japanese Patent Publication No. 5-43616, Japanese Patent Publication No. 5-209013, Japanese Patent Publication No. 6-239914, Japanese Patent Publication No. 7-504934, Japanese Patent Publication No. 8-85708, etc.

[0018] Furthermore, specifically, methylenebis(2-methylindenyl)zirconium dichloride, ethylenebis(2-methylindenyl)zirconium dichloride, ethylene 1,2-(4-phenylindenyl)(2-methyl-4-phenyl-4H-azlenyl)zirconium dichloride, isopropylidene(cyclopentadienyl)(fluorenyl)zirconium dichloride, isopropylidene(4-methylcyclopentadienyl)(3-t-butylindenyl)zirconium dichloride, dimethylsilylene(2-methyl-4-t-butyl-cyclopentadienyl)(3'-t-butyl-5'-methyl-cyclopentadienyl)zirconium dichloride, dimethylsilylenebis(indenyl) Zirconium dichloride (nyl), dimethylsilylenebis(4,5,6,7-tetrahydroindenyl) zirconium dichloride, dimethylsilylenebis[1-(2-methyl-4-phenylindenyl)] zirconium dichloride, dimethylsilylenebis[1-(2-ethyl-4-phenylindenyl)] zirconium dichloride, dimethylsilylenebis[4-(1-phenyl-3-methylindenyl)] zirconium dichloride, dimethylsilylene(fluorenyl)t-butylamide zirconium dichloride, methylphenylsilylenebis[1-(2-methyl-4,(1-naphthyl)-indenyl)] zirconium dichloride, dimethylsilylenebis[1-(2-methyl-4,5-Benzoindenyl) Zirconium dichloride, dimethylsilylenebis[1-(2-methyl-4-phenyl-4H-azlenyl)] Zirconium dichloride, dimethylsilylenebis[1-(2-ethyl-4-(4-chlorophenyl)-4H-azlenyl)] Zirconium dichloride, dimethylsilylenebis[1-(2-ethyl-4-naphthyl-4H-azlenyl)] Zirconium dichloride, diphenylsilylenebis[1-(2-methyl-4-(4-chlorophenyl)-4H-azlenyl)] Zirconium dichloride, diphenylsilylenebis[1-(2-methyl-4-(4-chlorophenyl)-4H-azlenyl] Examples of zirconium compounds include phenyl)-4H-azlenyl) zirconium dichloride, dimethylsilylenebis[1-(2-ethyl-4-(3-fluorobiphenylyl)-4H-azlenyl)] zirconium dichloride, dimethylgermylenebis[1-(2-ethyl-4-(4-chlorophenyl)-4H-azlenyl)] zirconium dichloride, and dimethylgermylenebis[1-(2-ethyl-4-phenylindenyl)] zirconium dichloride. Compounds in which zirconium is replaced with titanium or hafnium can also be used in the same way. In some cases, mixtures of zirconium compounds and hafnium compounds can also be used. Furthermore, the chloride can be replaced with other halogen compounds, hydrocarbon groups such as methyl, isobutyl, and benzyl, amide groups such as dimethylamide and diethylamide, alkoxide groups such as methoxy and phenoxy groups, and hydride groups. Of these, metallocene compounds in which an indenyl group or an azlenyl group is crosslinked with silicon or a gelmyl group are preferred.

[0019] Furthermore, metallocene compounds may be used supported on an inorganic or organic compound carrier. Preferred carriers are porous inorganic or organic compounds, specifically including inorganic compounds such as ion-exchangeable layered silicates, zeolites, SiO2, Al2O3, silica alumina, MgO, ZrO2, TiO2, B2O3, CaO, ZnO, BaO, and ThO2; organic compounds consisting of porous polyolefins, styrene-divinylbenzene copolymers, olefin-acrylic acid copolymers, or mixtures thereof.

[0020] (ii) Examples of co-catalysts that can react with metallocene compounds to activate them into a stable ionic state include organoaluminum oxy compounds (e.g., aluminoxane compounds), ion-exchangeable layered silicates, Lewis acids, boron-containing compounds, ionic compounds, and fluorine-containing organic compounds.

[0021] (iii) Examples of organoaluminum compounds include trialkylaluminum such as triethylaluminum, triisopropylaluminum, and triisobutylaluminum, dialkylaluminum halides, alkylaluminum sesquihalides, alkylaluminum dihalides, alkylaluminum hydrides, and organoaluminum alkoxides.

[0022] Methods for producing the propylene polymer (A) include slurry methods using an inert solvent in the presence of the catalyst, solution methods, gas-phase methods that substantially do not use a solvent, or bulk polymerization methods using polymerization monomers as a solvent. For example, slurry polymerization can be carried out in inert hydrocarbons or liquid monomers such as n-butane, isobutane, n-pentane, isopentane, hexane, heptane, octane, cyclohexane, benzene, toluene, and xylene. The polymerization temperature is usually -80 to 150°C, preferably 40 to 120°C. The polymerization pressure is preferably 1 to 60 atmospheres, and the molecular weight of the resulting propylene polymer (A) can be adjusted with hydrogen or other known molecular weight adjusting agents. Polymerization can be carried out in a continuous or batch reaction, and the conditions can be those commonly used. Furthermore, the polymerization reaction may be carried out in one step or in multiple steps.

[0023] (1-2) Requirements (A2) The melt flow rate (MFR: 230°C, 2.16 kg load) of the propylene polymer (A) is in the range of 0.5 to 100 g / 10 min.

[0024] The propylene polymer (A) used in the present invention has a melt flow rate (hereinafter sometimes abbreviated as MFR) in the range of 0.5 to 100 g / 10 min, in accordance with JIS K7120 (230°C, 2.16 kg load), preferably 10 to 80 g / 10 min, and more preferably 15 to 60 g / 10 min. By setting the melt flow rate of the propylene polymer (A) within this range, it is possible to obtain a molded article with good moldability and sufficient mechanical strength for the propylene resin composition for retort food containers of the present invention. In other words, if the melt flow rate (MFR) is less than 0.5 g / 10 min, the moldability will decrease, and it may be difficult to obtain a satisfactory product. Also, if it exceeds 100 g / 10 min, there is a concern that the mechanical strength will decrease.

[0025] (1-3) Requirements (A3) The propylene polymer (A) is at least one selected from the group consisting of propylene homopolymers and propylene-α-olefin random copolymers having an α-olefin content of less than 1% by weight.

[0026] The propylene-based polymer (A) is preferable from the viewpoint of heat resistance, such as when it is a propylene homopolymer, and from the viewpoint of transparency when it is a random copolymer consisting of propylene and α-olefin. In applications for retort food containers, sterilization is generally performed by pressurizing and heating at 121°C for about 3 minutes, and in some cases, by pressurizing and heating at 130°C for about 30 minutes. Therefore, in the present invention, by using a propylene homopolymer or a random copolymer consisting of propylene and α-olefin with a content of less than 1% by weight as the propylene polymer (A), it is possible to maintain good heat resistance while also achieving excellent transparency in the propylene resin composition of the present invention.

[0027] When the propylene polymer (A) is a random copolymer of propylene and α-olefin, the α-olefin used in copolymerization can be any α-olefin having 2 to 20 carbon atoms other than propylene, particularly α-olefins having 2 to 8 carbon atoms, such as ethylene, butene-1, hexene-1, octene-1, etc. One or more types of α-olefins can be copolymerized with propylene. Ethylene and butene-1 are preferred, and ethylene is more preferred, as this improves the properties of the propylene resin composition of the present invention. Furthermore, two or more of these propylene polymers may be used in mixture form. Also, if the α-olefin content is 1% by weight or more, it may become difficult to use from the viewpoint of heat resistance. Specific examples of propylene copolymers include binary or ternary copolymers formed by arbitrarily combining small amounts of copolymers, such as propylene-ethylene copolymer, propylene-butene-1 copolymer, propylene-hexene-1 copolymer, propylene-octene-1 copolymer, propylene-ethylene-butene-1 copolymer, propylene-ethylene-hexene-1 copolymer, and propylene-butene-1-octene-1 copolymer.

[0028] The α-olefin content in the propylene-α-olefin random copolymer is less than 1% by weight, preferably less than 0.5% by weight. If the α-olefin content is 1% by weight or more, the heat resistance decreases, increasing the likelihood of deformation during pressurized heat sterilization, which could lead to deformation. The propylene and α-olefin content in this specification is determined under the following conditions. 13 This value is measured by the 1C-NMR method, but it can also be measured using other instruments with equivalent performance. Equipment: JEOL-GSX270 manufactured by JEOL Ltd. Concentration: 300mg / 2mL Solvent: Orthodichlorobenzene

[0029] Furthermore, when the propylene-based polymer (A) used in the present invention is a propylene homopolymer, the isotactic pentad fraction is usually 0.90 or higher, preferably 0.94 to 0.98. By setting the isotactic pentad fraction within this range, the heat resistance of the propylene-based resin composition for retort food containers of the present invention can be improved, as well as its rigidity and barrier properties can be improved. In other words, if the isotactic pentad fraction is less than 0.90, the heat resistance, rigidity, and barrier properties may not be satisfactory. Here, the isotactic pentad fraction is, 13 This value is measured using a proton decoupling method with 1C-NMR.

[0030] (2) Propylene copolymer (B) The propylene copolymer (B) satisfies the following requirements (B1) to (B3).

[0031] (2-1) Requirements (B1) Propylene copolymer (B) is a metallocene-based propylene polymer. Since the propylene copolymer (B) is a metallocene propylene polymer, it can suppress bleeding on the surface of molded products after retort processing for the same reasons as the propylene polymer (A). The effects of using a metallocene propylene polymer as the other propylene copolymer (B) are the same as those detailed in the requirements (A1) for the propylene polymer (A).

[0032] The types of metallocene compounds used in the propylene copolymer (B) and their manufacturing methods are the same as those detailed in the requirements (A1) for the propylene polymer (A).

[0033] (2-2) Requirements (B2) The melt flow rate (MFR: 230°C, 2.16 kg load) of the propylene copolymer (B) is in the range of 0.5 to 80 g / 10 min.

[0034] The propylene copolymer (B) used in the present invention has a melt flow rate (MFR) in the range of 0.5 to 80 g / 10 min, in accordance with JIS K7120 (230°C, 2.16 kg load), preferably 10 to 60 g / 10 min, and more preferably 20 to 55 g / 10 min. By setting the melt flow rate (MFR) within this range, it is possible to obtain a molded article with good moldability and sufficient mechanical strength for the propylene resin composition for retort food containers of the present invention. In other words, if the melt flow rate (MFR) is less than 0.5 g / 10 min, the moldability will decrease, and it may be difficult to obtain a satisfactory product. Furthermore, if it exceeds 80 g / 10 min, there is a concern that the mechanical strength will decrease.

[0035] (2-3) Requirements (B3) The propylene copolymer (B) is a propylene-α-olefin random copolymer with an α-olefin content in the range of 3 to 17% by weight. The α-olefin content is preferably 5 to 15% by weight, and more preferably 7 to 13% by weight. By setting the α-olefin content within this range, the impact resistance and transparency of the propylene resin composition for retort food containers of the present invention can both be within a good range. That is, if the α-olefin content is less than 3% by weight, the impact resistance will be insufficient, and if the α-olefin content exceeds 17% by weight, the compatibility with component (A) produced in the first step will be poor, raising concerns about insufficient transparency.

[0036] The α-olefin used in the propylene polymer (B) is an α-olefin having 2 to 20 carbon atoms, excluding propylene, and is particularly known as an α-olefin having 2 to 8 carbon atoms. Examples include ethylene, butene-1, hexene-1, octene-1, etc. One or more types of α-olefins can be copolymerized with propylene. Ethylene and butene-1 are preferred, and ethylene is more preferred, as these can improve the properties of the propylene resin composition of the present invention. Specific examples of propylene copolymers include binary or ternary copolymers formed by arbitrarily combining small amounts of copolymers, such as propylene-ethylene copolymer, propylene-butene-1 copolymer, propylene-hexene-1 copolymer, propylene-octene-1 copolymer, propylene-ethylene-butene-1 copolymer, propylene-ethylene-hexene-1 copolymer, and propylene-butene-1-octene-1 copolymer.

[0037] (3) Propylene resin (X) (3-1) Requirements (X1) The propylene resin (X) contained in the propylene resin composition of the present invention satisfies requirement (X1). Requirements (X1): The propylene resin (X) contains 75-98% by weight of a propylene polymer (A) and 2-25% by weight of a propylene copolymer (B) (provided that the total of propylene polymer (A) and propylene copolymer (B) is 100% by weight).

[0038] The content of propylene polymer (A) is 75 to 98% by weight, preferably 80 to 95% by weight, and more preferably 85 to 90% by weight. The content of propylene copolymer (B) is 2 to 25% by weight, preferably 5 to 20% by weight, and more preferably 10 to 15% by weight (provided that the total of propylene polymer (A) and propylene copolymer (B) is 100% by weight). When the respective contents of propylene polymer (A) and propylene copolymer (B) in the propylene resin (X) are within the above ranges, the propylene resin composition for retort food containers of the present invention is less prone to stickiness and exhibits excellent impact resistance and heat resistance. That is, if the proportion of propylene polymer (A) is less than 75% by weight, there is a risk that the product will become sticky and its heat resistance will decrease. On the other hand, if the proportion of propylene polymer (A) exceeds 98% by weight, there is a risk that the rubber elasticity will be insufficient and the impact resistance will be insufficient.

[0039] (3-2) Requirements (X2) The propylene resin (X) may be a mixture of propylene polymer (A) and propylene copolymer (B) produced separately, provided that the respective contents of propylene polymer (A) and propylene copolymer (B) are within the above ranges, but it is preferable that the following requirement (X2) is met. Requirements (X2): The propylene resin (X) is a continuous polymer.

[0040] That is, the propylene resin (X) used in the present invention can preferably be obtained by polymerizing a propylene polymer (A), which is at least one selected from the group consisting of propylene homopolymers and propylene-α-olefin random copolymers having an α-olefin content of less than 1% by weight, by 75 to 98% by weight in the first step, and then by sequentially polymerizing a propylene copolymer (B), which is a propylene-α-olefin random copolymer having an α-olefin content in the range of 3 to 17% by weight, by 2 to 25% by weight in the second step (provided that the total of propylene polymer (A) and propylene copolymer (B) is 100% by weight). Furthermore, the propylene resin (X) may be a block copolymer, commonly known as such, obtained by sequentially polymerizing a propylene polymer (A) and a propylene copolymer (B), and it is not necessarily required that the propylene polymer (A) and the propylene copolymer (B) are completely bonded together in a block-like manner. The following description will use ethylene as the α-olefin as an example of a preferred embodiment. Conditions (A1) to (A3), conditions (B1) to (B3), and condition (X1) are as described above.

[0041] (3-2-1) Regarding the peak of the tanδ curve In the propylene-based resin composition of the present invention, when the propylene-based resin (X) satisfies condition (X2), it is preferable that the propylene-based polymer (A) and the propylene-based copolymer (B) constituting the propylene-based resin (X) used do not undergo phase separation in order to maintain good compatibility and transparency between the propylene-based polymer (A) and the propylene-based copolymer (B). The conditions for phase separation are affected not only by the ethylene content but also by the molecular weight and composition. Therefore, in addition to the ethylene content mentioned above, it is preferable that the tanδ curve obtained by solid viscoelasticity measurement (DMA) has a single peak below 0°C. When the propylene resin (X) adopts a phase-separated structure, the glass transition temperatures of the amorphous portion in the propylene polymer (A) and the amorphous portion in the propylene copolymer (B) are different, resulting in multiple peaks. Conversely, when they are miscible, the two components are mixed on a molecular level, and there is a single peak at a temperature intermediate between the glass transition temperatures of the two components. In other words, whether or not a phase-separated structure is adopted can be determined from the temperature-tanδ curve in solid viscoelasticity measurements, and in order to maintain transparency, it is preferable that the tanδ curve has a single peak below 0°C. Solid viscoelasticity measurement is specifically performed by applying a sinusoidal strain of a specific frequency to a strip-shaped sample and detecting the resulting stress. One example of measurement involves using a frequency of 1 Hz and gradually increasing the measurement temperature from -60°C until the sample melts and measurement becomes impossible. A strain magnitude of approximately 0.1 to 0.5% is recommended. From the obtained stress, the storage modulus G' and loss modulus G'' are determined by known methods, and when the loss tangent (= loss modulus / storage modulus), defined as the ratio of these two values, is plotted against temperature, a sharp peak is observed in the temperature range below 0°C. Generally, the peak in the tanδ curve below 0°C indicates the glass transition in the amorphous region, and this peak temperature is commonly defined as the glass transition temperature Tg (°C).

[0042] (3-2-2) Identification of [E]A and [E]B and the respective component amounts W(A) and W(B) In the propylene resin composition of the present invention, when the propylene resin (X) satisfies condition (X2), the ethylene content and amount of the propylene polymer (A) and the propylene copolymer (B) can be determined by the material balance during production. However, to determine them more accurately, it is desirable to use the following analysis.

[0043] (i) Identification of the amounts of each component W(A) and W(B) by temperature-reduced elution fractionation (TREF). In the propylene-based resin composition of the present invention, if the propylene-based resin (X) satisfies condition (X2), the ratio of the propylene-based polymer (A) to the propylene-based copolymer (B), i.e., the crystallinity distribution of the propylene-ethylene random copolymer, can be evaluated by TREF. This method is well known to the industry, and detailed measurement methods are shown in the following literature, for example. G.Glockner,J.Appl.Polym.Sci.:Appl.Polym.Symp.;45,1-24(1990) L.Wild,Adv.Polym.Sci.;98,1-47(1990) JBPSoares, AE Hamielec, Polymer;36,8,1639-1654(1995) In the present invention, the propylene-based resin (X) has significant differences in the crystallinity of the propylene-based polymer (A) and the propylene-based copolymer (B). Furthermore, because it is manufactured using a metallocene catalyst, the crystallinity distribution of each is narrowed, resulting in very few intermediate components between the two. Therefore, it is possible to accurately distinguish between the two using TREF. Specifically, it can be determined by referring to the method using diagrams showing the elution amount and the cumulative elution amount disclosed in Japanese Patent Publication No. 2010-121120, etc.

[0044] The specific method will be explained using the diagram in Figure 1, which shows the elution amount and integrated elution amount using TREF. In the TREF elution curve (plot of elution amount against temperature), component (A) and component (B) show their respective elution peaks at T(A) and T(B) due to the difference in crystallinity, and since the difference is sufficiently large, separation is possible at an intermediate temperature T(C) (={T(A)+T(B)} / 2). Furthermore, while the lower limit of the TREF measurement temperature is -15°C in the apparatus used in the present embodiment, if the propylene copolymer (B) has very low crystallinity or contains amorphous components, this measurement method may not show a peak within the measurement temperature range. (In this case, the concentration of the propylene copolymer (B) dissolved in the solvent at the lower limit of the measurement temperature (i.e., -15°C) will be detected.) In this case, T(B) is considered to be below the lower limit of the measurement temperature, but since its value cannot be measured, T(B) is defined as -15°C, which is the lower limit of the measurement temperature. Here, if we define the cumulative amount of components eluted by T(C) as W(B) by weight and the cumulative amount of components eluted above T(C) as W(A) by weight, then W(B) roughly corresponds to the amount of low-crystallinity or amorphous propylene copolymer (B), and the cumulative amount of components eluted above T(C) W(A) roughly corresponds to the amount of component (A) with relatively high crystallinity. The elution curve obtained by TREF and the method for calculating the various temperatures and amounts described above are exemplified in the figure showing the elution amount and cumulative elution amount disclosed in Japanese Patent Application Publication No. 2010-121120, etc.

[0045] (ii) TREF measurement method In the present invention, TREF is measured specifically as follows. The sample is dissolved in o-dichlorobenzene (containing 0.5 mg / mLBHT) at 140°C to prepare a solution. This solution is introduced into a TREF column at 140°C and cooled to 100°C at a rate of 8°C / min, then cooled to -15°C at a rate of 4°C / min and held for 60 minutes. Subsequently, the solvent, o-dichlorobenzene (containing 0.5 mg / mLBHT), is flowed through the column at a flow rate of 1 mL / min to elute the components dissolved in the o-dichlorobenzene at -15°C in the TREF column for 10 minutes. Then, the column is linearly heated to 140°C at a heating rate of 100°C / hour to obtain the elution curve.

[0046] (iii) Identification of the ethylene content [E]A and [E]B in each component. This section describes the ethylene content in propylene polymer (A) (hereinafter sometimes abbreviated as [E]A) and the ethylene content in propylene copolymer (B) (hereinafter sometimes abbreviated as [E]B). (i) Separation of propylene polymer (A) and propylene copolymer (B) Based on the T(C) obtained from the previous TREF measurement, the soluble propylene copolymer (B) and the insoluble propylene polymer (A) in T(C) are separated using a preparative separation apparatus and a heated column separation method, and the ethylene content of each component is determined by NMR. The temperature-controlled column fractionation method is used, for example, for macromolecules. 21 This refers to measurement methods such as those disclosed in 314-319 (1988). Specifically, the following method was used in the present invention.

[0047] (b) Separation conditions A cylindrical column with a diameter of 50 mm and a height of 500 mm is packed with glass bead carriers (80-100 mesh) and maintained at 140°C. Next, 200 mL of an o-dichlorobenzene solution (10 mg / mL) of the sample dissolved at 140°C is introduced into the column. Subsequently, the column temperature is cooled to 0°C at a rate of 10°C / hour. After being maintained at 0°C for 1 hour, the column temperature is heated to T(C) at a rate of 10°C / hour and maintained for 1 hour. The temperature control accuracy of the column throughout this series of operations should be ±1°C. Next, while maintaining the column temperature at T(C), 800 mL of o-dichlorobenzene at T(C) is flowed through the column at a flow rate of 20 mL / min to elute and recover the T(C)-soluble components present in the column. Next, the column temperature is raised to 140°C at a heating rate of 10°C / min. After standing at 140°C for 1 hour, 800 mL of solvent (o-dichlorobenzene) at 140°C is flowed through at a flow rate of 20 mL / min to elute and recover components insoluble in T(C). The polymer-containing solution obtained by fractionation is concentrated to 20 mL using an evaporator, and then precipitated in five times its volume of methanol. The precipitated polymer is collected by filtration and dried overnight in a vacuum dryer.

[0048] (ha) 13 Measurement of ethylene content by 13C-NMR The ethylene content of the propylene polymer (A) and propylene copolymer (B) obtained by the above separation was measured by the proton complete decoupling method under the following conditions. 13 This can be determined by analyzing the 1C-NMR spectrum, but it can also be measured using other instruments with equivalent performance. Model: JEOL Ltd. GSX-400 or equivalent device (Carbon nuclear resonance frequency of 100 MHz or higher) Solvent: o-dichlorobenzene / deuterated benzene = 4 / 1 (by volume) Concentration: 100mg / mL Temperature: 130℃ Pulse angle: 90° Pulse interval: 15 seconds Total number of times: 5,000 or more The spectral assignment is, for example, Macromolecules. 17 Refer to 1950 (1984), etc. for guidance. The classification of the spectra measured under the above conditions is as shown in the table below. (S in the table) αα These symbols are from Carman et al. (Macromolecules, 10 According to the notation of 536 (1977), P represents a methyl carbon, S represents a methylene carbon, and T represents a methine carbon.

[0049] [Table 1]

[0050] In the following, if "P" represents a propylene unit in the copolymer chain and "E" represents an ethylene unit, then six types of triads can exist in the chain: PPP, PPE, EPE, PEP, PEE, and EEE. Macromolecules, 15 As noted in 1150 (1982), the concentrations of these triads and the peak intensities of the spectrum are related by the following equations (1) to (6). [PPP] = k × I(T ββ ) (1) [PPE] = k × I(T) βδ ) (2) [EPE] = k × I(T) δδ ) (3) [PEP] = k × I(S) ββ ) (4) [PEE] = k × I(S βδ ) (5) [EEE] = k × [I(S δδ ) / 2+I(S γδ ) / 4} (6) Here, [ ] represents the fraction of a triad; for example, [PPP] is the fraction of the PPP triad among all triads. Therefore, [PPP]+[PPE]+[EPE]+[PEP]+[PEE]+[EEE]=1 (7) Furthermore, k is a constant, and I represents the spectral intensity, for example, I(T ββ ) is T ββ This refers to the intensity of the 28.7 ppm peak attributed to [the specific component].

[0051] By using the relationships (1) to (7) above, the fraction of each triad can be determined, and the ethylene content can be determined using the following formula. Ethylene content (mol %) = ([PEP] + [PEE] + [EEE]) × 100 Furthermore, the propylene random copolymer of the present invention contains small amounts of heteropolymer propylene bonds (2,1-bonds and / or 1,3-bonds), which result in the following minute peaks.

[0052] [Table 2]

[0053] To determine the exact ethylene content, it is necessary to include the peaks originating from these heterogeneous bonds in the calculation. However, complete separation and identification of these heterogeneous bond-derived peaks are difficult, and the amount of heterogeneous bonds is small. Therefore, the ethylene content of the present invention will be determined using the same relationship (1) to (7) as in the analysis of copolymers produced with a Ziegler catalyst that substantially does not contain heterogeneous bonds. The conversion of ethylene content from molar percentage to weight percentage is performed using the following formula. Ethylene content (weight %) = (28 × X / 100) / {28 × X / 100 + 42 × (1 - X / 100)} × 100 Here, X is the ethylene content expressed in mole percent. Furthermore, the total ethylene content [E]W of the propylene-ethylene block copolymer is calculated using the following formula from the ethylene content [E]A and [E]B of components (A) and (B) measured above, and the weight ratios of each component W(A) and W(B) calculated from TREF. [E]W={[E]A×W(A)+[E]B×W(B) / 100 (weight%) Furthermore, it is also possible to perform various measurements using other devices with equivalent performance.

[0054] (3-3) Other properties of propylene resin (X) (3-3-1) Melt Flow Rate (MFR) The melt flow rate (MFR, 230°C, 2.16 kg load) of the propylene resin (X) used in the present invention is typically 0.5 to 100 g / 10 min, preferably 10 to 80 g / 10 min, and more preferably 15 to 60 g / 10 min. By setting the MFR within this range, the moldability and impact resistance of the propylene resin composition for retort food containers of the present invention can both be kept within a good range. Specifically, if the MFR is less than 0.5 g / 10 min, molding may become difficult, and if it exceeds 100 g / 10 min, impact resistance may decrease. The melt flow rate (MFR) can be easily adjusted by controlling the polymerization conditions of the propylene resin (X), such as temperature and pressure, or by controlling the amount of hydrogen added during polymerization to which chain transfer agents such as hydrogen are added. Here, MFR is a value measured in accordance with JIS K7210, at a heating temperature of 230°C and a load of 2.16 kg.

[0055] (3-3-2) Melting peak temperature (Tm) The melting peak temperature (hereinafter sometimes abbreviated as Tm) of the propylene resin (X) used in the present invention, as measured by differential scanning calorimeter (DSC), is usually in the range of 110 to 170°C, and preferably 120 to 165°C. By setting the melting peak temperature within this range, it is possible to improve the moldability of the propylene resin composition of the present invention while maintaining good impact resistance. That is, if the melting peak temperature (Tm) is below 110°C, the cooling and solidification rate of the molten propylene resin will be slow, which may worsen the moldability. Also, if it exceeds 170°C, the impact resistance may deteriorate. The melting peak temperature (Tm) can be easily adjusted by controlling the amount of α-olefin supplied to the polymerization reaction system. In the examples described herein, Tm is specifically measured using a differential scanning calorimeter (DSC). A sample of 5 mg is taken, held at 200°C for 5 minutes, then crystallized at a cooling rate of 10°C / min down to 40°C, and finally melted at a heating rate of 10°C / min. The peak position of the curve drawn during this process is defined as the melting peak temperature Tm (°C).

[0056] (3-3-3) Molecular weight distribution (Mw / Mn) The molecular weight distribution (hereinafter sometimes abbreviated as Mw / Mn) of the propylene-based resin (X) used in this invention, as measured by gel permeation (GPC), is usually in the range of 1.5 to 4, and preferably between 1.8 and less than 3. By setting the molecular weight distribution (Mw / Mn) within this range, it becomes possible to easily manufacture pellets that are not sticky and are easy to handle. In other words, a molecular weight distribution (Mw / Mn) of less than 1.5 is difficult to obtain with current polymerization technology, and a value exceeding 4 is undesirable because it may result in a sticky product (pellets). Methods for adjusting the molecular weight distribution of propylene-ethylene block copolymer include, to narrow the range, using the aforementioned metallocene catalyst, or by melt-kneading with an organic peroxide after polymerization of the propylene-ethylene block copolymer. To broaden the range, it can be adjusted by polymerization using a catalyst system that uses two or more metallocene catalyst components in combination, or a catalyst system that uses two or more metallocene complexes in combination. Here, the molecular weight distribution is determined by the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) (Mw / Mn), and can be obtained by measuring it using gel permeation chromatography (GPC). The conversion from retention capacity to molecular weight is performed using a calibration curve prepared in advance using standard polystyrene. An example is shown below.

[0057] The standard polystyrene used is the following brands manufactured by Tosoh Corporation: F380, F288, F128, F80, F40, F20, F10, F4, F1, A5000, A2500, and A1000. A calibration curve is created by injecting 0.2 ml of a solution in which each of these polystyrenes is dissolved in o-dichlorobenzene (containing 0.5 mg / ml of BHT) so that the concentration is 0.5 mg / ml. The calibration curve uses a cubic equation obtained by approximating using the least squares method. The following values ​​are used for the viscosity equation [η] = K × Mα, which is used for conversion to molecular weight. PS: K=1.38×10 -4 α = 0.7 PP: K=1.03×10-4 α = 0.78 The measurement conditions for GPC are as follows: Equipment: WATERS GPC (ALC / GPC 150C) Detector: FOXBORO MIRAN 1A IR detector (measurement wavelength: 3.42 μm) Columns: Showa Denko AD806M / S (3 pieces) Mobile phase solvent: o-dichlorobenzene Measurement temperature: 140℃ Flow rate: 1.0ml / min Injection amount: 0.2ml Sample preparation: The sample is dissolved in a 1 mg / ml solution using o-dichlorobenzene (containing 0.5 mg / ml of BHT) at 140°C for approximately 1 hour. Furthermore, it is also possible to perform various measurements using other devices with equivalent performance.

[0058] (3-4) Method for producing propylene resin (X) As described above, the propylene resin (X) is preferably a continuous polymer (requirement (X2)), and both the propylene polymer (A) and propylene copolymer (B) constituting the propylene resin (X) are metallocene-based propylene polymers. Therefore, the method for producing the propylene resin (X) requires the use of a metallocene catalyst. The following explanation will use ethylene as an example of an α-olefin. (i) Metallocene catalysts It is widely known among manufacturers that a wide molecular weight and crystallinity distribution in propylene-ethylene random copolymers worsens stickiness and bleed-out. In the propylene resin (X) used in the present invention, it is necessary to polymerize it using a metallocene catalyst that narrows the molecular weight and crystallinity distribution in order to suppress stickiness and bleed-out. The metallocene catalyst is as described in requirements (A1) and (B1) above, but when the propylene resin (X) used in the present invention satisfies requirement (X2), it is preferable to use the following metallocene catalyst.

[0059] The type of metallocene catalyst is not particularly limited as long as it can produce a copolymer having the performance of the present invention. However, in order to satisfy the requirements of the present invention, it is preferable to use a metallocene catalyst consisting of components (a), (b), and component (c) as shown below, if necessary. Component (a): At least one metallocene transition metal compound selected from transition metal compounds represented by the following general formula. Component (b): At least one solid component selected from (b-1) to (b-4) below. (b-1) Particulate carrier on which an organoaluminum oxy compound is supported, (b-2) A particulate carrier on which an ionic compound or Lewis acid capable of reacting with component (a) to convert component (a) into a cation is supported. (b-3) Solid acid fine particles (b-4) Ion exchange layered silicate, Component (c): Organoaluminum compound.

[0060] (ii) Component (a) As component (a), at least one metallocene transition metal compound selected from the transition metal compounds represented by the following general formula can be used. Q(C5H4-aR 1 )(C5H4-bR 2 )MeXY [Here, Q represents a divalent bonding group that bridges two conjugated five-membered ring ligands, Me represents a metal atom selected from titanium, zirconium, and hafnium, and X and Y represent a hydrogen atom, a halogen atom, a hydrocarbon group, an alkoxy group, an amino group, a nitrogen-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, or a silicon-containing hydrocarbon group, and X and Y may be independent of each other, i.e., identical or different. R 1 , R 2 represents hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, a silicon-containing hydrocarbon group, a nitrogen-containing hydrocarbon group, an oxygen-containing hydrocarbon group, a boron-containing hydrocarbon group, or a phosphorus-containing hydrocarbon group. a and b are the number of substituents.

[0061] More specifically, Q represents a divalent bonding group that bridges two conjugated five-membered ring ligands. Examples include a divalent hydrocarbon group, a silylene group or oligosilylene group, a silylene group or oligosilylene group having a hydrocarbon group as a substituent, or a germylene group having a hydrocarbon group as a substituent. Among these, the preferred ones are a divalent hydrocarbon group and a silylene group having a hydrocarbon group as a substituent. X and Y represent a hydrogen atom, a halogen atom, a hydrocarbon group, an alkoxy group, an amino group, a nitrogen-containing hydrocarbon group, a phosphorus-containing hydrocarbon group, or a silicon-containing hydrocarbon group. Preferred examples among these include hydrogen, chlorine, methyl, isobutyl, phenyl, dimethylamide, and diethylamide groups. X and Y may be independent of each other, i.e., they may be the same or different. R 1 and R 2This represents hydrogen, a hydrocarbon group, a halogenated hydrocarbon group, a silicon-containing hydrocarbon group, a nitrogen-containing hydrocarbon group, an oxygen-containing hydrocarbon group, a boron-containing hydrocarbon group, or a phosphorus-containing hydrocarbon group. Specific examples of hydrocarbon groups include methyl, ethyl, propyl, butyl, hexyl, octyl, phenyl, naphthyl, butenyl, and butadienyl groups. Typical examples of halogenated hydrocarbon groups, silicon-containing hydrocarbon groups, nitrogen-containing hydrocarbon groups, oxygen-containing hydrocarbon groups, boron-containing hydrocarbon groups, or phosphorus-containing hydrocarbon groups include methoxy, ethoxy, phenoxy, trimethylsilyl, diethylamino, diphenylamino, pyrazolyl, indolyl, dimethylphosphono, diphenylphosphono, diphenylboron, and dimethoxyboron groups. Among these, it is preferable that the hydrocarbon group has 1 to 20 carbon atoms, and particularly preferable that it be a methyl, ethyl, propyl, or butyl group. 1 and R 2 These may be bonded together to form a ring, and this ring may have substituents consisting of a hydrocarbon group, a halogenated hydrocarbon group, a silicon-containing hydrocarbon group, a nitrogen-containing hydrocarbon group, an oxygen-containing hydrocarbon group, a boron-containing hydrocarbon group, or a phosphorus-containing hydrocarbon group. Me is a metal atom selected from titanium, zirconium, and hafnium, and is preferably zirconium or hafnium.

[0062] Among the components (a) described above, those preferred for the production of the propylene-based resin (X) used in the present invention are transition metal compounds comprising ligands having a substituted cyclopentadienyl group, a substituted indenyl group, a substituted fluorenyl group, or a substituted azlenyl group crosslinked with a hydrocarbon-substituted silylene group, a germylene group, or an alkylene group, and particularly preferred are transition metal compounds comprising ligands having a 2,4-substituted indenyl group or a 2,4-substituted azlenyl group crosslinked with a hydrocarbon-substituted silylene group or a germylene group. Non-specific examples include dimethylsilylenebis(2-methyl-4-phenylindenyl)zirconium dichloride, diphenylsilylenebis(2-methyl-4-phenylindenyl)zirconium dichloride, dimethylsilylenebis(2-methylbenzoindenyl)zirconium dichloride, dimethylsilylenebis{2-isopropyl-4-(3,5-diisopropylphenyl)indenyl}zirconium dichloride, dimethylsilylenebis(2-propyl-4-phenanthrylindenyl)zirconium dichloride, and dimethylsilylenebis(2-methyl-4-phenylazure Examples include zirconium dichloride (nyl), dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)azlenyl}zirconium dichloride, dimethylsilylenebis(2-ethyl-4-phenylazlenyl)zirconium dichloride, dimethylsilylenebis(2-isopropyl-4-phenylazlenyl)zirconium dichloride, dimethylsilylenebis{2-ethyl-4-(2-fluorobiphenyl)azlenyl}zirconium dichloride, and dimethylsilylenebis{2-ethyl-4-(4-t-butyl-3-chlorophenyl)azlenyl}zirconium dichloride. Compounds obtained by replacing the silylene group with a germylene group and zirconium with hafnium in these specific examples are also exemplified as suitable compounds. Since the catalyst component is not an essential element of the present invention, a lengthy list has been avoided and only representative examples have been provided. However, it is self-evident that this does not limit the effective scope of the present invention.

[0063] (iii) component (b) As component (b), at least one solid component selected from components (b-1) to (b-4) described above is used. Each of these components is known and can be appropriately selected and used from known technologies. Detailed examples of specific components and manufacturing methods can be found in Japanese Patent Publication Nos. 2002-284808, 2002-53609, 2002-69116, and 2003-105015. Here, examples of particulate carriers used in components (b-1) and (b-2) include inorganic oxides such as silica, alumina, magnesia, silica-alumina, and silica-magnesia; inorganic halides such as magnesium chloride, magnesium oxychloride, aluminum chloride, and lanthanum chloride; and porous organic carriers such as polypropylene, polyethylene, polystyrene, styrene-divinylbencene copolymer, and acrylic acid copolymer. Furthermore, non-limiting specific examples of component (B) include particulate carriers on which methyl almoxane, isobutyl almoxane, methyl isobutyl almoxane, aluminum tetraisobutyl butylboronate, etc. are supported as component (b-1); particulate carriers on which triphenylborane, tris(3,5-difluorophenyl)borane, tris(pentafluorophenyl)borane, triphenylcarbonium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, etc. are supported as component (b-2); alumina, silica alumina, magnesium chloride, etc. as component (b-3); and smectite group, vermiculite group, mica group, etc., such as montmorillonite, zakonite, byderite, nontronite, saponite, hectorite, stevensite, bentonite, and teniolite, etc., as well as components (b-4). These may also form a mixed layer. Of the above components (b), the most preferred is the ion-exchangeable layered silicate of component (b-4), and even more preferred is the ion-exchangeable layered silicate that has been subjected to chemical treatments such as acid treatment, alkali treatment, salt treatment, or organic matter treatment.

[0064] (iv) Component (c) Examples of organoaluminum compounds that may be used as component (c) as needed are: General formula AlR a P 3-a (In the formula, R is a hydrocarbon group having 1 to 20 carbon atoms, P is hydrogen, halogen, an alkoxy group, and a is a number where 0 < a ≦ 3), trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum and other trialkylaluminums, or halogen- or alkoxy-containing alkylaluminums such as diethylaluminum monochloride and diethylaluminum monomethoxide. In addition, aluminoxanes such as methylaluminoxane can also be used. Among these, trialkylaluminum is particularly preferred.

[0065] (v) Formation of catalyst Component (a) and component (b) and, if necessary, component (c) are brought into contact to form a catalyst. The contact method is not particularly limited, but they can be contacted in the following order. Also, this contact may be carried out not only during catalyst preparation but also during prepolymerization with an olefin or during polymerization of an olefin. 1) Contact component (a) and component (b) 2) After contacting component (a) and component (b), add component (c) 3) After contacting component (a) and component (c), add component (b) 4) After contacting component (b) and component (c), add component (a) In addition, the three components may be contacted simultaneously.

[0066] The amounts of components (a), (b), and (c) used in the present invention are arbitrary. For example, the amount of component (a) used with respect to component (b) is preferably in the range of 0.1 μmol to 1,000 μmol, particularly preferably 0.5 μmol to 500 μmol, per 1 g of component (b). The amount of component (c) used with respect to component (b) is preferably such that the amount of transition metal is in the range of 0.001 to 100 μmol, particularly preferably 0.005 to 50 μmol, per 1 g of component (b). Therefore, the amount of component (c) with respect to component (a) is preferably in the range of 10 -5 ~50, particularly preferably 10 -4 ~5 in terms of the molar ratio of the transition metal.

[0067] The catalyst used in the production of the propylene-based resin (X) of the present invention is preferably subjected to a prepolymerization treatment, which involves contacting an olefin and polymerizing a small amount of it beforehand. The olefin used is not particularly limited, but ethylene, propylene, 1-butene, 1-hexene, 1-octene, 4-methyl-1-pentene, 3-methyl-1-butene, vinylcycloalkane, styrene, etc. can be used, and propylene is particularly preferred. Any method of supplying the olefin is possible, such as supplying the olefin to the reaction vessel at a constant rate or under constant pressure, a combination thereof, or by introducing stepwise changes. The prepolymerization temperature and time are not particularly limited, but are preferably in the range of -20°C to 100°C and 5 minutes to 24 hours, respectively. The amount of prepolymerization is preferably 0.01 to 100, more preferably 0.1 to 50, of the amount of prepolymerized polymer relative to component (b). After prepolymerization is completed, the catalyst can be used as is, depending on the form of use, but drying can also be performed if necessary. Furthermore, it is possible to include polymers such as polyethylene, polypropylene, and polystyrene, or inorganic oxide solids such as silica and titania, in the presence of these components during or after contact.

[0068] (vi) Polymerization method (vi-1) Sequential polymerization In manufacturing the propylene resin (X) used in the present invention, it is preferable to perform continuous polymerization (hereinafter sometimes referred to as sequential polymerization) of component (A) and component (B) because this satisfies requirement (X2). In the present invention, the propylene resin (X) is preferably a block copolymer obtained by sequentially polymerizing components with different ethylene content in the first and second steps, as this allows for a balance of transparency, flexibility, impact resistance, and heat resistance. Furthermore, in the present invention, a copolymer with a low molecular weight and a tendency to become sticky on its own may be used as component (B). Therefore, in order to prevent problems such as adhesion to the reactor, it is preferable to polymerize component (A) first and then polymerize component (B). When performing stepwise polymerization, either the batch method or the sequential method can be used, but generally, the sequential method is preferable from a productivity standpoint.

[0069] In the batch method, it is possible to polymerize component (A) and component (B) individually using a single reactor by changing the polymerization conditions over time. Multiple reactors may be connected in parallel, as long as they do not hinder the effects of the present invention. In the case of the continuous process, it is necessary to polymerize component (A) and component (B) individually, so it is necessary to use a manufacturing facility in which two or more reactors are connected in series. However, as long as the effects of the present invention are not hindered, multiple reactors may be connected in series and / or parallel for each of component (A) and component (B).

[0070] (vi-2) Polymerization process The polymerization process can utilize any polymerization method, such as slurry methods, bulk methods, or gas-phase methods. While supercritical conditions can be used as an intermediate condition between bulk and gas-phase methods, they are essentially equivalent to gas-phase methods and are therefore included in the gas-phase method without special distinction. Since component (B) is readily soluble in organic solvents such as hydrocarbons and liquefied propylene, it is desirable to use a gas-phase method when manufacturing component (B). While there are no particular problems with any process used to manufacture component (A), when manufacturing component (A) with relatively low crystallinity, it is preferable to use a gas-phase method to avoid problems such as adhesion. Therefore, it is most desirable to use a continuous process in which component (A) is first polymerized by a bulk method or a gas-phase method, and then component (B) is polymerized by a gas-phase method.

[0071] (vi-3) Other polymerization conditions Polymerization temperatures can be used without any particular problems as long as they are within the commonly used temperature range. Specifically, a range of 0°C to 200°C, preferably 40°C to 100°C, can usually be used. The polymerization pressure will vary depending on the selected process, but it can generally be used without any problems within the commonly used pressure range. Specifically, a range greater than 0 and up to 200 MPa, more preferably 0.1 MPa to 50 MPa, can be used. In this case, an inert gas such as nitrogen may be present. When sequential polymerization of component (A) in the first step and component (B) in the second step is carried out, it is desirable to add a polymerization inhibitor to the system in the second step. When producing a propylene-ethylene block copolymer, adding a polymerization inhibitor to the reactor in which ethylene-propylene random copolymerization is carried out in the second step can improve the particle properties (such as fluidity) of the resulting powder and the product quality such as gels. Various technical studies have been conducted on this method, and examples include Japanese Patent Publication No. 63-54296, Japanese Patent Application Publication No. 7-25960, and Japanese Patent Application Publication No. 2003-2939. It is desirable to apply this method to the present invention as well.

[0072] (3-5) Method for controlling the components of propylene resin (X) Each element of the propylene resin (X) used in the present invention is controlled as follows, and a propylene resin (X) that satisfies the desired physical properties can be manufactured so that the effects of the propylene resin composition of the present invention can be realized.

[0073] (3-5-1) Component (A) For component (A) to satisfy the requirements of this application, the ethylene content [E]A and preferably T(A) as shown in Figure 1 are controlled. In this invention, in order to control [E]A within a predetermined range, the ratio of propylene to ethylene supplied to the polymerization tank in the first step can be appropriately adjusted. The relationship between the supply ratio and the ethylene content in the resulting propylene-ethylene random copolymer varies depending on the type of metallocene catalyst used, but by adjusting the supply ratio, a component (A) having the required ethylene content [E]A can be produced. For example, to control [E]A to less than 1% by weight, the supply weight ratio of ethylene to propylene should be in the range of 0.3 or less, preferably 0.2 or less. In this case, component (A) has a narrow crystalline distribution, and T(A) decreases with increasing [E]A. Therefore, if you want to control T(A) within a specific range, you need to understand the relationship between [E]A and these values ​​and adjust them to take the target range.

[0074] (3-5-2) Component (B) For component (B) to satisfy the requirements of this application, the ethylene content [E]B and preferably T(B) as shown in Figure 1 are controlled. In the present invention, in order to control [E]B within a predetermined range, the supply ratio of ethylene to propylene in the second step should be controlled, similar to [E]A. For example, to control [E]B to 3-17% by weight, the supply weight ratio of ethylene to propylene should be in the range of 0.005-6, preferably 0.01-3. At this time, although a slight increase in the crystalline distribution of component (B) is observed with increasing ethylene content, T(B) decreases with increasing [E]B, similar to component (A). Therefore, if you want to control T(B) within a specific range, you can understand the relationship between [E]B and T(B) and control it accordingly.

[0075] (3-5-3) W(A) and W(B) The amounts of component (A) W(A) and component (B) W(B) can be controlled by changing the ratio of the production amount of component (A) to the production amount of component (B) in the first process. For example, to increase W(A) and decrease W(B), one can reduce the production amount in the second process while maintaining the production amount in the first process. This can be easily controlled by shortening the residence time in the second process, lowering the polymerization temperature, or increasing the amount of polymerization inhibitor. The reverse is also true. When actually setting the conditions, it is necessary to consider the decay of activity. That is, in the range of ethylene content [E]A and [E]B implemented in the present invention, generally, increasing the ethylene supply ratio to propylene in order to increase the ethylene content increases polymerization activity, but at the same time, the decay of activity tends to increase. Therefore, in order to maintain the activity of the second step, it is necessary to suppress the polymerization activity of the first step. Specifically, the conditions can be set by lowering the ethylene content [E]A in the first step, lowering the production amount W(A), and if necessary, lowering the polymerization temperature and / or shortening the polymerization time (residence time), or by increasing the ethylene content [E]B in the second step, increasing the production amount W(B), and if necessary, raising the polymerization temperature and / or lengthening the polymerization time (residence time).

[0076] (3-5-4) Glass transition temperature Tg In the present invention, the propylene-based resin (X) used preferably has a glass transition temperature Tg, which is the temperature at which the tanδ curve obtained from the temperature-loss tangent curve obtained by solid viscoelasticity measurement shows a peak, and has a single peak at 0°C or below. In order for Tg to have a single peak, the difference between the ethylene content [E]A in component (A) and the ethylene content [E]B in component (B), [E]gap (=[E]B-[E]A), should normally be 20% by weight or less, preferably 16% by weight or less, and the [E]gap should be reduced to the range in which Tg has a single peak in actual measurement. By setting the supply weight ratio of ethylene to propylene during polymerization of component (B) so that the ethylene content [E]B in component (B) falls within an appropriate range, depending on the ethylene content [E]A in component (A), a propylene-ethylene block copolymer having a predetermined [E]gap can be obtained.

[0077] Furthermore, if the propylene resin (X) used in the present invention satisfies requirement (X2) and preferably does not adopt a phase-separated structure, the Tg of the propylene resin (X) is affected by the ethylene content [E]A in component (A) and the ethylene content [E]B in component (B), and the ratio of the amounts of both components. In the present invention, the amount of component (B) is 2 to 25% by weight, and within this range, the Tg is more strongly affected by the ethylene content [E]B in component (B). In other words, Tg reflects the glass transition of the amorphous region, but in the propylene resin (X) used in the present invention, component (A) is crystalline and has relatively few amorphous regions, while component (B) is low in crystalline or amorphous, and is almost entirely amorphous. Therefore, the value of Tg is controlled almost entirely by [E]B, and the method for controlling [E]B is as described above.

[0078] 2. Nucleoforming agent (C) The propylene resin composition for retort food containers of the present invention contains a nucleating agent (C) that satisfies the following requirement (C1). Requirements (C1) The nucleating agent (C) is at least one selected from the group consisting of nucleating agents represented by the following formulas (1), (2), and (3).

[0079] R 1 (CONHR 2 ) a Formula (1)

[0080] In equation (1), R 1 This represents a saturated or unsaturated aliphatic polycarboxylic acid residue having 2 to 30 carbon atoms, a saturated or unsaturated alicyclic polycarboxylic acid residue having 4 to 28 carbon atoms, or an aromatic polycarboxylic acid residue having 6 to 18 carbon atoms. R 2 This represents an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, or a cycloalkyl group or cycloalkenyl group having 3 to 46 carbon atoms. 'a' represents an integer between 2 and 6.

[0081] The nucleating agent represented by formula (1) is preferably the nucleating agent represented by formula (4), and more preferably the nucleating agent represented by formula (5).

[0082] [ka]

[0083] In formula (4), R 1 R represents a trivalent saturated aliphatic hydrocarbon group having 3 to 10 carbon atoms, a tetravalent saturated aliphatic hydrocarbon group having 4 to 10 carbon atoms, a trivalent or tetravalent saturated alicyclic hydrocarbon group having 5 to 15 carbon atoms, or a trivalent or tetravalent aromatic hydrocarbon group having 6 to 15 carbon atoms. 2 Each represents either a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms, either identical or distinct. 'a' represents an integer of 3 or 4.

[0084] [ka]

[0085] In formula (5), R 1 This represents a residue obtained by removing all carboxyl groups from 1,2,3-propanetricarboxylic acid or 1,2,3,4-butanetetracarboxylic acid. 3 or 4 R 2 Each of the following elements represents either a hydrogen atom or a linear or branched alkyl group having 1 to 10 carbon atoms, and they are either identical or different from each other. 'a' represents an integer of 3 or 4.

[0086] Specifically, these include 1,2,3-propanetricarboxylic acid tricyclohexylamide, 1,2,3-propanetricarboxylic acid tri(2-methylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-methylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-methylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(2-ethylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-ethylcyclohexylamide), and 1,2,3-propanetricarboxylic acid tri(4-ethylcyclo Hexylamide), 1,2,3-propanetricarboxylic acid tri(2-n-propylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-n-propylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-n-propylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(2-iso-propylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-iso-propylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-iso-propylcyclohexylamide) (Propanetricarboxylic acid tri(2-n-butylcyclohexylamide), 1,2,3-Propanetricarboxylic acid tri(3-n-butylcyclohexylamide), 1,2,3-Propanetricarboxylic acid tri(4-n-butylcyclohexylamide), 1,2,3-Propanetricarboxylic acid tri(2-iso-butylcyclohexylamide), 1,2,3-Propanetricarboxylic acid tri(3-iso-butylcyclohexylamide), 1,2,3-Propanetricarboxylic acid tri(4-iso-butylcyclohexylamide), 1,2 ,3-propanetricarboxylic acid tri(2-sec-butylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-sec-butylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-sec-butylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(2-tert-butylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-tert-butylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-n-pentylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-n-hexylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-n-heptylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-n-octylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri[4-(2-ethylhexyl)cyclohexylamide], 1,2,3-propanetricarboxylic acid tri(4-n-nonylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-n-decylcyclohexylamide), 1,2,3-propanetricarboxylic acid [(cyclohexylamide)di(2-methylcyclohexylamide)], 1,2,3-propanetricarboxylic acid [di(cyclohexylamide)(2-methylcyclohexylamide)],

[0087] 1,2,3,4-Butanetetracarboxylic acid tetracyclohexylamide, 1,2,3,4-Butanetetracarboxylic acid tetra(2-methylcyclohexylamide), 1,2,3,4-Butanetetracarboxylic acid tetra(3-methylcyclohexylamide), 1,2,3,4-Butanetetracarboxylic acid tetra(4-methylcyclohexylamide), 1,2,3,4-Butanetetracarboxylic acid tetra(2-ethylcyclohexylamide), 1,2,3,4-Butanetetracarboxylic acid tetra(3-ethylcyclohexylamide), 1,2,3,4-Butane Tetra(4-ethylcyclohexylamide) tetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid tetra(2-n-propylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(3-n-propylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(4-n-propylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(2-iso-propylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(3-iso-propylcyclohexylamide) (mid), 1,2,3,4-butanetetracarboxylic acid tetra(4-iso-propylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(2-n-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(3-n-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(4-n-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(2-iso-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(3- iso-butylcyclohexylamide)1,2,3,4-butanetetracarboxylic acid tetra(4-iso-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(2-sec-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(3-sec-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(4-sec-butylcyclohexylamide), 1,2,3,4-Butanetetracarboxylic acid tetra(3-tert-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(4-tert-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(4-n-pentylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(4-n-hexylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(4-n-heptylcyclohexylamide), 1,2,3,4-butane Examples include tetra(4-n-octylcyclohexylamide) tetracarboxylic acid, 1,2,3,4-butanetetracarboxylic acid tetra[4-(2-ethylhexyl)cyclohexylamide], 1,2,3,4-butanetetracarboxylic acid tetra(4-n-nonylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(4-n-decylcyclohexylamide), and 1,2,3,4-butanetetracarboxylic acid [di(cyclohexylamide)di(2-methylcyclohexylamide)].

[0088] Among the above amide compounds, in particular from the viewpoint of nucleation (nuclear agent effect), R in formula (4) or formula (5) 2 A preferred amide compound is one in which the atom is a hydrogen atom or a linear or branched alkyl group having 1 to 4 carbon atoms. Specifically, 1,2,3-propanetricarboxylic acid tricyclohexylamide, 1,2,3-propanetricarboxylic acid tri(2-methylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-methylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-methylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(2-ethylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-ethylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-ethylcyclohexylamide) (Propanetricarboxylic acid tri(2-n-propylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-n-propylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-n-propylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(2-iso-propylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-iso-propylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-iso-propylcyclohexylamide) Xylamide), 1,2,3-propanetricarboxylic acid tri(2-n-butylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-n-butylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-n-butylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(2-iso-butylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-iso-butylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-iso-butylcyclohexylamide, 1,2,3-propanetricarboxylic acid tri(2-sec-butylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-sec-butylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-sec-butylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(2-tert-butylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-tert-butylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-tert-butylcyclohexylamide,

[0089] 1,2,3,4-butanetetracarboxylic acid tetra(cyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(2-methylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(3-methylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(4-methylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(2-ethylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(3-ethylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(3-ethylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(cyclohexylamide). 1,2,3,4-butanetetracarboxylic acid tetra(4-ethylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(2-n-propylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(3-n-propylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(4-n-propylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(2-iso-propylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(3-iso-propylcyclohexyl 1,2,3,4-butanetetracarboxylic acid tetra(4-iso-propylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(2-n-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(3-n-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(4-n-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(2-iso-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(3- iso-butylcyclohexylamide)1,2,3,4-butanetetracarboxylic acid tetra(4-iso-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(2-sec-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(3-sec-butylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(4-sec-butylcyclohexylamide), 1,2,3,Examples include tetra(3-tert-butylcyclohexylamide) 4-butanetetracarboxylic acid and tetra(4-tert-butylcyclohexylamide) 1,2,3,4-butanetetracarboxylic acid.

[0090] Among these preferred amide compounds, R in formula (4) or formula (5) is particularly desirable from the viewpoint of the balance between transparency and rigidity and the ease of obtaining raw materials. 2 Amide compounds in which the atom is a hydrogen atom or a methyl group are particularly preferred. Specifically, examples include 1,2,3-propanetricarboxylic acid tricyclohexylamide, 1,2,3-propanetricarboxylic acid tri(2-methylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-methylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(4-methylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(2-methylcyclohexylamide), 1,2,3,4-butanetetracarboxylic acid tetra(3-methylcyclohexylamide), and 1,2,3,4-butanetetracarboxylic acid tetra(4-methylcyclohexylamide).

[0091] Furthermore, if the improvement in transparency is a priority, the R in equation (1), equation (4), or equation (5) should be adjusted. 1 Amide compounds, which are residues obtained by removing all carboxyl groups from 1,2,3-propanetricarboxylic acid, are particularly preferred. Specifically, examples include 1,2,3-propanetricarboxylic acid tricyclohexylamide, 1,2,3-propanetricarboxylic acid tri(2-methylcyclohexylamide), 1,2,3-propanetricarboxylic acid tri(3-methylcyclohexylamide), and 1,2,3-propanetricarboxylic acid tri(4-methylcyclohexylamide).

[0092] The above-mentioned amide compounds can be used individually or in appropriate combinations of two or more.

[0093] The crystalline form of the nucleating agent represented by formula (1), formula (4), or formula (5), which is selectively used in the present invention, is not particularly limited as long as the effects of the present invention are obtained, and any crystalline form such as hexagonal, monoclinic, or cubic can be used. These crystals are also known or can be manufactured according to known methods.

[0094] The nucleating agents represented by formula (1), formula (4), or formula (5), which are selectively used in the present invention, are preferably substantially 100% pure, but may contain some impurities as long as they do not impair the effects of the present invention. Even if impurities are present, the purity of the nucleating agent is preferably 90% by weight or more, more preferably 95% by weight or more, and particularly recommended to be 97% by weight or more. Examples of impurities include monoamide dicarboxylic acids or their ester compounds, diamide monocarboxylic acids or their ester compounds, and imide compounds derived from reaction intermediates or unreacted products.

[0095] The method for producing the nucleating agent represented by formula (1), formula (4), or formula (5), which is selectively used in the present invention, is not particularly limited as long as the desired nucleating agent can be obtained. For example, it can be produced from a specific aliphatic polycarboxylic acid component and a specific alicyclic monoamine component according to conventionally known methods (e.g., Japanese Patent Publication Nos. 2006-298881, 2007-291029, PCT / JP2006 / 307246, and JP-A-7-242610).

[0096] Examples of the above-mentioned aliphatic polycarboxylic acid components include 1,2,3-propanetricarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, acid chlorides and anhydrides of the polycarboxylic acid, and derivatives such as esters of the polycarboxylic acid with lower alcohols having 1 to 4 carbon atoms. These aliphatic polycarboxylic acid components can be subjected to amidation alone or in combination of two types.

[0097] The above-mentioned alicyclic monoamine component is at least one selected from the group consisting of cyclohexylamine and cyclohexylamine substituted with a linear or branched alkyl group having 1 to 10 carbon atoms (preferably 1 to 4 carbon atoms), and can be subjected to amidation alone or as a mixture of two or more. Specifically, examples include methylcyclohexylamines such as cyclohexylamine, 2-methylcyclohexylamine, 3-methylcyclohexylamine, 4-methylcyclohexylamine, 2-ethylcyclohexylamine, 2-n-propylcyclohexylamine, 2-iso-propylcyclohexylamine, 2-n-butylcyclohexylamine, 2-iso-butylcyclohexylamine, 2-sec-butylcyclohexylamine, and 2-tert-butylcyclohexylamine.

[0098] The cyclohexylamine substituted with the alkyl group described above may be the cis isomer, the trans isomer, or a mixture of these stereoisomers. A preferred cis:trans ratio is in the range of 50:50 to 0:100, and particularly in the range of 35:65 to 0:100.

[0099] The particle size of the nucleating agent represented by formula (1), formula (4), or formula (5), which is selectively used in the present invention, is not particularly limited as long as the effects of the present invention are obtained. However, from the viewpoint of dissolution rate (or dissolution time) in molten propylene polymers, it is preferable to have the smallest possible particle size. When the particle size measurement obtained by laser diffraction scattering is adopted, the maximum particle size of the nucleating agent is recommended to be 200 μm or less, preferably 100 μm or less, more preferably 50 μm, and particularly 10 μm or less.

[0100] The most common method for adjusting the maximum particle size to within the above range is to use a grinding device known in this field, and a known classification device can also be used if necessary. Specifically, examples of grinding devices include the fluidized bed counter jet mill 100AFG (trade name, manufactured by Hosokawa Micron Corporation), the supersonic jet mill PJM-200 (trade name, manufactured by Nippon Pneumatic Co., Ltd.), and pin mills, while examples of classification devices include vibrating screens and dry classifiers (cyclones, micron separators, etc.). Other devices with equivalent performance can also be used.

[0101] Furthermore, in the propylene-based resin composition of the present invention, one of the selectively used nucleating agents (C) is an organophosphate metal salt compound represented by the following formula (2). TIFF2026093132000007.tif50155

[0102] In equation (2), R 1 These are directly bonded, sulfur, and alkylene or alkylidene groups having 1 to 9 carbon atoms. R 2 and R 3 These are, either identical or different, each independently, a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. M is Na, and n is the valence of M.

[0103] Specific examples of organophosphate metal salt compounds represented by formula (2) include sodium-2,2'-methylene-bis-(4,6-di-t-butylphenyl)phosphate, sodium-2,2'-ethylidene-bis-(4,6-di-t-butylphenyl)phosphate, sodium-2,2'-ethylidene-bis-(4-i-propyl-6-t-butylphenyl)phosphate, sodium-2,2'-butylidene-bis-(4,6-dimethylphenyl)phosphate, sodium-2,2'-butylidene-bis-(4,6-di-t-butylphenyl)phosphate, sodium-2,2'-t-octylmethylene-bis-(4,6-methylphenyl)phosphate, and sodium-2,2'-t-octylmethylene-bis Examples include -(4,6-di-t-butylphenyl)phosphate, sodium-2,2'-methylene-bis-(4-methyl-6-t-butylphenyl)phosphate, sodium-2,2'-methylene-bis-(4-ethyl-6-t-butylphenyl)phosphate, sodium (4,4'-dimethyl-6,6'-di-t-butyl-2,2'-biphenyl)phosphate, sodium-2,2'-ethylidene-bis-(4-s-butyl-6-t-butylphenyl)phosphate, sodium-2,2'-methylene-bis-(4,6-di-methylphenyl)phosphate, sodium-2,2'-methylene-bis-(4,6-di-ethylphenyl)phosphate, and mixtures of two or more of these. Of these, sodium-2,2'-methylene-bis-(4,6-di-t-butylphenyl)phosphate is particularly preferred. Commercially available nucleating agents can be used for this purpose. Specifically, NA-11 manufactured by ADEKA Corporation is one example.

[0104] Furthermore, in the propylene-based resin composition of the present invention, one of the selectively used nucleating agents (C) is an aromatic phosphate ester represented by the following formula (3).

[0105] TIFF2026093132000008.tif51150

[0106] In equation (3), R 1 This represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R 2 and R 3 These represent, either identical or distinct, a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, independently. M represents a metal atom from Group III or Group IV of the periodic table, and X represents HO- if M represents a metal atom from Group III of the periodic table, and O= or (HO)2- if M represents a metal atom from Group IV of the periodic table.

[0107] Specific examples of nucleating agents represented by formula (3) include, for example, hydroxyaluminum-bis[2,2'-methylene-bis(4,6-dimethylphenyl)phosphate], hydroxyaluminum-bis[2,2'-ethylidene-bis(4,6-dimethylphenyl)phosphate], hydroxyaluminum-bis[2,2'-methylene-bis(4,6-diethylphenyl)phosphate], and hydroxyaluminum-bis[2,2'-ethylidene-bis(4 ,6-diethylphenyl)phosphate], hydroxyaluminum-bis[2,2'-methylene-bis(4,6-di-t-butylphenyl)phosphate], and hydroxyaluminum-bis[2,2'-ethylidene-bis(4,6-di-t-butylphenyl)phosphate], hydroxyaluminum-bis[2,2'-methylene-bis(4-methyl-6-t-butylphenyl)phosphate], hydroxyaluminum-bis[2,2'- Examples include ethylidene-bis(4-methyl-6-t-butylphenyl)phosphate, hydroxyaluminum-bis[2,2'-methylene-bis(4-ethyl-6-t-butylphenyl)phosphate], hydroxyaluminum-bis[2,2'-ethylidene-bis(4-ethyl-6-t-butylphenyl)phosphate], hydroxyaluminum-bis[2,2'-methylene-bis(4-i-propyl-6-t-butylphenyl)phosphate], hydroxyaluminum-bis[2,2'-ethylidene-bis(4-i-propyl-6-t-butylphenyl)phosphate], and mixtures of two or more of these. Preferably, examples include hydroxyaluminum-bis[2,2'-methylene-bis(4,6-di-t-butylphenyl)phosphate], hydroxyaluminum-bis[2,2'-ethylidene-bis(4,6-di-t-butylphenyl)phosphate], and mixtures of two or more of these.

[0108] Aromatic phosphate esters represented by formula (3) are effective when used in combination with organoalkali metal salts. The term "organoalkali metal salt" can refer to at least one organoalkali metal salt selected from the group consisting of alkali metal carboxylates, alkali metal β-diketnates, and alkali metal β-ketoacetate salts. Examples of alkali metals constituting the organoalkali metal salt include lithium, sodium, and potassium. Examples of carboxylic acids constituting the alkali metal carboxylates above include aliphatic monocarboxylic acids such as acetic acid, propionic acid, acrylic acid, octyl acid, isooctyl acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, ricinoleic acid, 12-hydroxystearic acid, behenic acid, montanic acid, melissic acid, β-dodecylmercaptoacetic acid, β-dodecylmercaptopropionic acid, β-N-laurylaminopropionic acid, and β-N-methyllauroylaminopropionic acid, as well as aliphatic polycarboxylic acids such as malonic acid, succinic acid, adipic acid, maleic acid, azelaic acid, sebacic acid, dodecanediic acid, citric acid, butanetricarboxylic acid, and butanetetracarboxylic acid. Examples include naphthenic acid, cyclopentanecarboxylic acid, 1-methylcyclopentanecarboxylic acid, 2-methylcyclopentanecarboxylic acid, cyclopentenecarboxylic acid, cyclohexanecarboxylic acid, 1-methylcyclohexanecarboxylic acid, 4-methylcyclohexanecarboxylic acid, 3,5-dimethylcyclohexanecarboxylic acid, 4-butylcyclohexanecarboxylic acid, 4-octylcyclohexanecarboxylic acid, cyclohexenecarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, and other alicyclic mono or polycarboxylic acids; benzoic acid, toluic acid, xylyl acid, ethylbenzoic acid, 4-t-butylbenzoic acid, salicylic acid, phthalic acid, trimellitic acid, pyromellitic acid, and other aromatic mono or polycarboxylic acids.

[0109] Examples of β-diketone compounds that constitute the alkali metal β-dikenates mentioned above include acetylacetone, pivaloylacetone, palmitoylacetone, benzoylacetone, pivaloylbenzoylacetone, and dibenzoylmethane. Furthermore, examples of β-ketoacetic acid esters that constitute the alkali metal β-ketoacetic acid salts mentioned above include ethyl acetoacetate, octyl acetoacetate, lauryl acetoacetate, stearyl acetoacetate, ethyl benzoyl benzoyl acetate, and lauryl benzoyl acetate.

[0110] The alkali metal carboxylates, alkali metal β-diketones, or alkali metal β-ketoacetic acid salts that are components of the organic alkali metal salt are salts of the alkali metal with a carboxylic acid, a β-diketone compound, or a β-ketoacetic acid ester, and can be produced by conventionally known methods. Among these alkali metal salt compounds, alkali metal aliphatic monocarboxylates are preferred, particularly lithium aliphatic carboxylates, and especially aliphatic monocarboxylates having 8 to 20 carbon atoms are preferred.

[0111] Commercially available nucleating agents can be used for this purpose. Specifically, NA-21 manufactured by ADEKA Corporation is one example.

[0112] The propylene resin composition of the present invention satisfies the following condition (1). Condition (1) The propylene-based resin composition for retort food containers contains 0.01 to 0.6 parts by weight of a nucleating agent (C) per 100 parts by weight of propylene-based resin (X).

[0113] The content of the nucleating agent (C) selectively used in the propylene resin composition of the present invention is in the range of 0.01 to 0.6 parts by weight per 100 parts by weight of the propylene resin (X). By setting the content of the nucleating agent (C) within this range, it is possible to obtain the maximum effect of the nucleating agent (C) with an appropriate amount in the propylene resin composition of the present invention. In other words, if the amount used is less than 0.01 parts by weight, the effect of the nucleating agent (C) cannot be obtained, and if it exceeds 0.6 parts by weight, even if the content is increased, the effect of the nucleating agent (C) plateaus, and not only is no further effect obtained, but it is also economically undesirable.

[0114] When the nucleating agent (C) used in the propylene resin composition of the present invention is a nucleating agent represented by formula (1), formula (4), or formula (5), its content is in the range of 0.01 to 0.6 parts by weight per 100 parts by weight of the propylene resin (X), preferably in the range of 0.01 to 0.02 parts by weight, and more preferably in the range of 0.015 to 0.18 parts by weight. By setting the content of the nucleating agent (C) represented by formula (1), formula (4), or formula (5) within this range, it is possible to obtain the maximum effect of the nucleating agent (C) with an appropriate amount in the propylene resin composition of the present invention. That is, if the content is less than 0.01 parts by weight, the effect of the nucleating agent (C) cannot be obtained, and in the range exceeding 0.6 parts by weight, even if the content is increased, the effect of the nucleating agent (C) plateaus, and the effect commensurate with the content cannot be obtained, making it uneconomical.

[0115] When the nucleating agent (C) used in the propylene resin composition of the present invention is an organophosphate metal salt compound represented by formula (2), its content is in the range of 0.01 to 0.6 parts by weight per 100 parts by weight of propylene resin (X), preferably in the range of 0.01 to 0.2 parts by weight, and more preferably in the range of 0.05 to 0.15 parts by weight. By setting the content of the nucleating agent (C) represented by formula (2) within this range, it is possible to obtain the maximum effect of the nucleating agent (C) with an appropriate amount in the propylene resin composition of the present invention. That is, if the content is less than 0.01 parts by weight, the effect of the nucleating agent (C) cannot be obtained, and if it exceeds 0.6 parts by weight, even if the content is increased, the effect of the nucleating agent (C) plateaus, and an effect commensurate with the content cannot be obtained, so not only is it not possible to obtain further effects, but it is also economically undesirable.

[0116] When the nucleating agent (C) used in the propylene resin composition of the present invention is an aromatic phosphoric acid ester represented by formula (3), its content is in the range of 0.01 to 0.6 parts by weight per 100 parts by weight of propylene resin (X), preferably in the range of 0.01 to 0.3 parts by weight, and more preferably in the range of 0.05 to 0.2 parts by weight. By setting the content of the nucleating agent (C) represented by formula (3) within this range, it is possible to obtain the maximum effect of the nucleating agent (C) with an appropriate amount in the propylene resin composition of the present invention. That is, if the content is less than 0.01 parts by weight, the effect of the nucleating agent (C) cannot be obtained, and if it exceeds 0.6 parts by weight, even if the content is increased, the effect of the nucleating agent (C) plateaus, and an effect commensurate with the content cannot be obtained, so not only is it not possible to obtain further effects, but it is also economically undesirable.

[0117] In addition to the nucleating agent (C), the propylene resin composition of the present invention may use the following nucleating agents (a) to (b).

[0118] The nucleating agent (a) is a compound represented by the following formula (6), of which the compound represented by the following formula (7) is preferred, and the compound represented by the following formula (8) is more preferred.

[0119] TIFF2026093132000009.tif42152[In equation (2), n is an integer between 0 and 2, R 1 ~R 5 These are the same or different hydrogen atoms or alkyl groups, alkenyl groups, alkoxy groups, carbonyl groups, halogen groups, and phenyl groups having 1 to 20 carbon atoms, respectively. 6 These are alkyl groups with 1 to 20 carbon atoms.

[0120] TIFF2026093132000010.tif37153[In equation (7), n is an integer between 0 and 2, R 1 , R 2 , R 4 , R 5 R is a hydrogen atom, 3R is a hydrogen atom or an alkyl group, alkenyl group, alkoxy group, carbonyl group, halogen group, or phenyl group having 1 to 20 carbon atoms. 6 These are alkyl groups with 1 to 20 carbon atoms.

[0121] TIFF2026093132000011.tif42152

[0122] Commercially available nucleating agents can be used for this purpose. Specifically, one example is NX8000, manufactured by Milliken Co., Ltd.

[0123] The nucleating agent (a) is one of the few nucleating agents that provides excellent transparency to the resulting molded product and has extremely low odor and elution properties.

[0124] The content of the nucleating agent (a) used in the propylene resin composition of the present invention is in the range of 0.01 to 0.6 parts by weight per 100 parts by weight of the propylene resin (X). By setting the content of the nucleating agent (a) within this range, it is possible to obtain the maximum effect of the nucleating agent (a) with an appropriate amount in the propylene resin composition of the present invention. That is, if the content is less than 0.01 parts by weight, it is difficult to obtain a sufficient effect from the nucleating agent (a), and if it is used in amounts exceeding 0.6 parts by weight, even if the content is increased, the effect of the nucleating agent (a) will plateau, and an effect commensurate with the content will not be obtained, so further improvement in performance cannot be expected, which is not only uneconomical but also carries the risk of defects such as deposition on the surface of the molded product. 0.1 to 0.4 parts by weight is preferred, and 0.2 to 0.35 parts by weight is more preferred.

[0125] The nucleating agent (b) is the nucleating agent shown in formula (9).

[0126] TIFF2026093132000012.tif50156

[0127] In formula (9), M1 and M2 are the same or different metal cations selected from calcium, strontium, lithium and monobasic aluminum, and R1, R2, R3, R4, R5, R6, R7, R8, R9 and R 10 Each of these is selected, either identically or differently, from the group consisting of hydrogen, C1-C9 alkyl (where any two vicinal (bonded to adjacent carbons) or geminal (bonded to the same carbon) alkyl groups may together form a hydrocarbon ring having up to six carbon atoms), hydroxyl, C1-C9 alkoxy, C1-C9 alkylene oxy, amine and C1-C9 alkylamine, halogen (fluorine, chlorine, bromine and iodine), and phenyl.

[0128] Here, the term "monobasic aluminum" is well known and is intended to refer to an aluminum hydroxide group as a single cation bonded to two carboxylic acid groups. Furthermore, in each of these possible salts, the stereochemistry of the asymmetric carbon atom may be cis or trans, but cis is preferred.

[0129] The nucleating agent represented by formula (9) may be used in combination with other compounds for the purpose of preventing aggregation, etc. Commercially available nucleating agents can be used for this purpose. Specifically, Hyperform HPN68L manufactured by Meriken Co., Ltd. can be mentioned. The structure of the nucleating agent component of Hyperform HPN68L is shown below.

[0130] TIFF2026093132000013.tif42157

[0131] The content of the nucleating agent (b) is preferably in the range of 0.005 to 0.15 parts by weight, more preferably in the range of 0.01 to 0.1 parts by weight, based on 100 parts by weight of the propylene-based resin (X). By setting the content of the nucleating agent (b) within such a range, in the propylene-based resin composition of the present invention, it becomes possible to obtain the maximum effect with an appropriate amount of the nucleating agent (b). That is, if the content is less than 0.005 parts by weight, the effect of the nucleating agent (b) cannot be obtained, and if it exceeds 0.15 parts by weight, even if the content is increased, the effect of the nucleating agent (b) reaches a plateau and an effect commensurate with the content cannot be obtained, which is not economical.

[0132] In the propylene-based resin composition of the present invention, in addition to the nucleating agent (C) and the above nucleating agents (a) and (b), as other nucleating agents, known nucleating agents such as organic phosphate-based nucleating agents, aromatic phosphoric acid esters, and talc can be added within a range that does not significantly inhibit the effects of the present invention.

[0133] 3. Propylene-based resin composition of the present invention The propylene-based resin composition of the present invention can contain additives in a range that does not impair the object of the present invention, in addition to the above-described propylene-based resin (X) and nucleating agent (C).

[0134] (1) Neutralizing agent In the propylene-based resin composition of the present invention, it is desirable to incorporate a neutralizing agent. Specific examples of the neutralizing agent include metal fatty acid salts such as calcium stearate, zinc stearate, and magnesium stearate, hydrotalcite (a magnesium-aluminum composite hydroxide salt represented by the following formula (10) of Kyowa Chemical Industry Co., Ltd.), Mizukalack (a lithium-aluminum composite hydroxide salt represented by the following formula (11)), and the like.

[0135] Mg 1-x Al x (OH)2(CO3) x / 2 ·mH2O … Formula (10) [In the formula, x is 0 < x ≦ 0.5, and m is a number of 3 or less.]

[0136] [Al2Li(OH)6] n X·mH2O…Formula (11) [In the formula, X is an inorganic or organic anion, n is the valence of the anion (X), and m is 3 or less.]

[0137] The amount of neutralizing agent used in the propylene resin composition of the present invention is preferably in the range of 0.005 to 0.2 parts by weight, and more preferably in the range of 0.01 to 0.05 parts by weight, per 100 parts by weight of the propylene resin (X).

[0138] (2) Lubricant In the propylene resin composition of the present invention, it is desirable to incorporate a lubricant. Examples of known lubricants include oleamide and erucamide, as well as butyl stearate, silicone oil, calcium stearate (usually used as a neutralizing agent), and monoglyceride stearate (commonly used as an antistatic agent). These components are highly safe and act as lubricants that can improve moldability (such as release properties and scratch prevention) and the slipperiness of molded products. Furthermore, adding silicones such as dimethylpolysiloxane not only prevents scratches that occur during molding, but also prevents burning that occurs inside the cylinder and hot runner.

[0139] The amount of lubricant used in the propylene resin composition of the present invention is usually 0.001 to 0.5 parts by weight, preferably 0.01 to 0.15 parts by weight, and particularly preferably 0.03 to 0.1 parts by weight, per 100 parts by weight of the propylene resin (X). By setting the lubricant content within this range, it becomes possible to obtain the maximum effect of the lubricant with an appropriate amount in the propylene resin composition of the present invention. In other words, if the content is less than 0.001 parts by weight, the effect of the lubricant cannot be expected, and if it exceeds 0.5 parts by weight, even if the content is increased, the effect of the lubricant plateaus, and an effect commensurate with the content cannot be obtained, so not only is further effect not expected, but it is also economically undesirable.

[0140] (3) Other additives In the propylene-based resin composition of the present invention, in addition to the components described above, various antioxidants and other additives used as stabilizers for propylene-based polymers may be incorporated.

[0141] Specifically, as antioxidants, phosphorus-based antioxidants include bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol-di-phosphite, di-stearyl-pentaerythritol-di-phosphite, bis(2,4-di-t-butylphenyl)pentaerythritol-di-phosphite, tris(2,4-di-t-butylphenyl)phosphite, tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylene-di-phosphonate, and tetrakis(2,4-di-t-butyl-5-methylphenyl)-4,4'-biphenylene-di-phosphonate. Examples of antioxidants include phenolic antioxidants such as 2,6-di-t-butyl-p-cresol, tetrakis[methylene(3,5-di-t-butyl-4-hydroxyhydrocinnamate)]methane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, and tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, as well as thio-based antioxidants such as di-stearyl-ββ'-thio-dipropionate, di-myristyl-ββ'-thio-dipropionate, and di-lauryl-ββ'-thio-dipropionate.

[0142] Furthermore, examples of antioxidants include amine-based antioxidants represented by the following general formulas (12) and (13) with good resistance to NOx gas discoloration, lactone-based antioxidants such as 5,7-di-t-butyl-3-(3,4-di-methylphenyl)-3H-benzofuran-2-one, and vitamin E-based antioxidants such as the following general formula (14).

[0143] TIFF2026093132000014.tif37158

[0144] TIFF2026093132000015.tif43156

[0145] TIFF2026093132000016.tif31155

[0146] Furthermore, other substances such as antistatic agents, slip agents, dispersants such as fatty acid metal salts, dyes, pigments, polyethylene, and olefin-based elastomers can be incorporated to the extent that they do not impair the objectives of the present invention. Within limits that do not impair the properties, functions, transparency, and other characteristics of the propylene-based resin composition of the present invention, 1 to 30 parts by weight of other polymers, monopolymers, binary copolymers, or ternary copolymers such as polyethylene, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-butene-1 copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylate copolymer, or acrylate polymer may be optionally added. Similarly, 1 to 30 parts by weight of elastomers such as natural rubber, butyl rubber, diene rubber, EPR, and EPDM may also be blended in. Furthermore, general-purpose inorganic fillers such as talc, calcium carbonate, silica, alumina, gypsum, and mica may also be used in combination.

[0147] (4) Method for producing the propylene resin composition of the present invention The propylene resin composition of the present invention can be obtained by mixing a propylene resin (X), at least one mixture selected from the group consisting of nucleating agents represented by formulas (1), (2), and (3) which are used selectively, and other additives as needed, in a Henschel mixer, super mixer, ribbon blender, etc., and then melt-kneading it at a temperature range of 190 to 260°C in a conventional single-screw extruder, twin-screw extruder, Banbury mixer, plastic bender, roll, etc.

[0148] 4. Molded products for retort food containers The molded articles for retort food containers of the present invention can be obtained by molding the above-mentioned propylene-based resin composition of the present invention using various molding methods such as injection molding, extrusion molding, and blow molding, which are known methods. However, injection molding is preferable as it offers high dimensional accuracy and makes it easy to create complex shapes. The molded articles for retort food containers of the present invention are useful for retort applications, and are particularly suitable for retort applications where transparency and impact resistance are required. [Examples]

[0149] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by these descriptions. In each example and comparative example, the physical property measurements were performed by the following methods, and the following propylene resins, nucleating agents, and other additives (antioxidants, neutralizing agents) were used.

[0150] 1. Measurement Method (1) Temperature-induced elution and fractionation (TREF) The TREF measurement method is as follows: [Device] (TREF section) TREF column: 4.3mmφ × 150mm stainless steel column Column packing material: 100 μm surface-inert treated glass beads Heating method: Aluminum heat block Cooling method: Peltier element (Peltier element is cooled with water) Temperature distribution: ±0.5℃ Temperature controller: Chino Corporation Digital Program Controller KP1000 (Valve Oven) Heating method: Air bath oven Temperature during measurement: 140℃ Temperature distribution: ±1℃ Valves: 6-way valve, 4-way valve (Sample injection section) Injection method: Loop injection method Injection volume: Loop size 0.1 ml Inlet heating method: Aluminum heat block Temperature during measurement: 140℃ (Detection unit) Detector: Wavelength-fixed infrared detector, FOXBORO MIRAN 1A Detection wavelength: 3.42 μm High-temperature flow cell: Microflow cell for LC-IR, optical path length 1.5mm, window shape 2φ×4mm oval, synthetic sapphire window plate. Temperature during measurement: 140℃ (Pump section) Liquid transfer pump: SSC-3461 pump manufactured by Senshu Kagaku Co., Ltd. [Measurement conditions] Solvent: o-dichlorobenzene (containing 0.5 mg / mL of BHT) Sample concentration: 5 mg / mL Sample injection volume: 0.1 mL Solvent flow rate: 1 mL / min

[0151] (2) Calculation of the amount of each component It was calculated using TREF and the method described above.

[0152] (3) Calculation of ethylene content 13 Ethylene-propylene random copolymer, whose composition was analyzed by 13C-NMR, was used as the reference material at 733 cm⁻¹. -1 The ethylene content in the random copolymer was measured by infrared spectroscopy using a characteristic absorber. A film approximately 500 microns thick was formed from pellets by press molding.

[0153] (4) MFR Measurements were taken in accordance with JIS K7210, at a heating temperature of 230°C and a load of 2.16 kg.

[0154] (5) Haze value Using a 1mm thick sheet, the pre-sterilization values ​​were measured in accordance with JIS K7105. Furthermore, sterilization was performed using a gear oven at 121°C for 30 minutes, followed by rapid cooling of the sheet in 2°C ice water. The post-sterilization values ​​were then measured in accordance with JIS K7105. A gear oven was used because rapid cooling was desired compared to high-pressure steam treatment (using Sakura SI Co., Ltd.'s high-temperature, high-pressure cooking sterilization test machine YRF-40 / 50EZ).

[0155] (6) Odor A 1mm thick sheet was placed in an odor test bag, and the odor was checked after 24 hours. ○: Good condition with almost no anaerobic odors. ×: It has an unpleasant odor.

[0156] (7) Flexural modulus Measurements were taken at 23°C in accordance with JIS K7171.

[0157] (8) Charpy impact value Measurements were taken at 23°C in accordance with JIS K7111.

[0158] (9) Heat resistance (HDT) Measurements were taken at 0.45 MPa in accordance with JIS K7191. (10) Gloss Measurements were taken in accordance with JIS Z8741. The retort treatment involved high-pressure steam treatment at 120°C for 20 minutes (equipment: Sakura SI Co., Ltd. high-temperature high-pressure cooking sterilization test machine YRF-40 / 50EZ). The △ gloss level indicates the difference in gloss before and after high-pressure steam treatment. (11) Melting temperature (Tm) Measurements were performed using a TA Instruments Q2000 DSC. A 5.0 mg sample was taken, held at 200°C for 5 minutes, then cooled to -10°C at a rate of 10°C / min. After holding at -10°C for 5 minutes, it was heated to 200°C at a rate of 10°C / min. The peak top temperature of the crystallization curve obtained during cooling was defined as the crystallization temperature, and the peak top temperature of the melting curve obtained during heating was defined as the melting temperature (Tm). (12) Molecular weight distribution (Mw / Mn) The molecular weight distribution was determined by the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn) (Mw / Mn), and the weight-average molecular weight (Mw) and number-average molecular weight (Mn) were obtained by gel permeation chromatography (GPC). The conversion from retention capacity to molecular weight was performed using a calibration curve prepared in advance using standard polystyrene. The standard polystyrene used was the following brand manufactured by Tosoh Corporation. F380,F288,F128,F80,F40,F20,F10,F4,F1,A5000,A2500,A1000 A solution prepared by dissolving each in o-dichlorobenzene (containing 0.5 mg / ml of BHT) to a concentration of 0.5 mg / ml was injected in an amount of 0.2 ml to prepare a calibration curve. The calibration curve was approximated by a cubic equation obtained by the least squares method. For the viscosity equation [η]=K×Mα used for conversion to molecular weight, the following values were used. PS: K = 1.38×10 -4 α = 0.7 PP: K = 1.03×10 -4 α = 0.78 The measurement conditions for GPC were as follows. Apparatus: GPC manufactured by WATERS (ALC / GPC 150C) Detector: MIRAN 1A IR detector manufactured by FOXBORO (measurement wavelength: 3.42 μm) Column: AD806M / S manufactured by Showa Denko K.K. (3 columns) Mobile phase solvent: o-dichlorobenzene Measurement temperature: 140 °C Flow rate: 1.0 ml / min Injection volume: 0.2 ml Sample preparation: The sample was prepared as a 1 mg / ml solution using o-dichlorobenzene (containing 0.5 mg / ml of BHT) and dissolved at 140 °C for about 1 hour.

[0159] 2. Materials Used (1) Nucleating agent NA11: AdekaStab NA-11 (trade name of ADEKA CORPORATION): Equivalent to formula (2) of nucleating agent (C) NA21: AdekaStab NA-21 (trade name of ADEKA CORPORATION): Equivalent to formula (3) of nucleating agent (C) XT386: IRGACLEAR XT386 (trade name of BASF): Equivalent to formula (1) of nucleating agent (C) GAMD: Gelol MD (trade name of Shin Nippon Rika Co., Ltd.): Nucleating agent other than nucleating agent (C)

[0160] (2) Antioxidant IR1010: Irganox 1010 (BASF brand name): Phenolic antioxidant IR1076: Irganox 1076 (BASF brand name): Phenolic antioxidant IF168: Irgaphos 168 (BASF brand name): Phosphorus-based antioxidant

[0161] (3) Neutralizing agent CAST: Calcium stearate (manufactured by NOF Corporation)

[0162] 3. Manufacturing of propylene resin (X) Various propylene-based resins (X) were manufactured using the following procedure.

[0163] (1) Production of propylene resin (x-1) [Manufacturing Example 1: Manufacturing of Solid Catalyst (a)] A solid catalyst (a) for olefin polymerization was prepared in the same manner as the catalyst preparation using dichlorosilanecyclobutylenebis[2-(5-methyl-2-furyl)-4-phenyl-1,5,6,7-tetrahydro-s-indasen-1-yl]zirconium (metallocene complex A) in Example 1 of Japanese Patent Publication No. 2015-193605 (Catalyst A), and a solid catalyst (a) for olefin polymerization with a propylene prepolymerization ratio (value obtained by dividing the amount of prepolymerized polymer by the amount of solid catalyst) of 1.91 was obtained.

[0164] [Manufacturing Example 2: Manufacturing of Propylene Resin] Propylene polymers were produced using two continuous gas-phase polymerization reactors equipped with catalyst storage tanks and agitators. The production method is described in detail below. Internal volume 40m 3 Solid catalyst (a) produced in Production Example 1 was continuously supplied to the first polymerization reactor at a rate of 0.34 kg / h as a solid catalyst component, and triisobutylaluminum was continuously supplied at a rate of 3.3 kg / h. In addition, liquefied propylene was continuously supplied to maintain a constant temperature in the reactor for heat removal during the polymerization reaction, and hydrogen was supplied so that the gas concentration in the reactor was 0.002 in terms of the molar ratio of hydrogen to propylene. The temperature of the first polymerization reactor was controlled to 62°C and the pressure to 2.15 MPaG, and (a-1) was produced as the propylene polymer (A). The propylene polymer (a-1) produced in the first polymerization reactor is stored in a 40 m³ reactor with an internal volume such that the amount of polymer contained in the first polymerization reactor is 45% of the reactor volume. 3 It was then extracted and placed in the second polymerization reactor.

[0165] Analysis of the propylene polymer (a-1) obtained in the first polymerization step revealed that the yield per gram of solid catalyst was 16.8 kg, the ethylene content was 0% by weight, the MFR (at 230°C and with a 2.16 kg load) was 21.5 g / 10 min, and the molecular weight distribution (Mw / Mn) was 3.5.

[0166] In the second polymerization reactor, while supplying liquid propylene for heat removal, similar to the first polymerization reactor, hydrogen was supplied so that the gas concentration in the reactor was 0.0014 in terms of the molar ratio of hydrogen to propylene, and ethylene was supplied so that the gas concentration in the reactor was 0.26 in terms of the molar ratio of ethylene to propylene. Furthermore, the temperature of the second polymerization reactor was controlled to 60°C and the pressure to 2.1 MPaG. In addition, ethanol, an activity inhibitor, was supplied to the first polymerization reactor and the second polymerization reactor so that the supply ratio of liquefied propylene for heat removal was 85 to 15, thereby producing (b-1) as the propylene copolymer (B). The polymer produced in the second polymerization reactor was extracted as a product so that the amount of polymer contained in the second polymerization reactor was 45% by volume of the reactor volume. The product extraction rate (production rate) at this time was 6.8 t / h. The polymer obtained was a propylene-based resin (x-1).

[0167] Analysis of the obtained polymer (x-1) revealed that the yield per gram of solid catalyst was 19.8 kg, the MFR (at 230°C and with a 2.16 kg load) was 18 g / 10 min, the ethylene content was 1.65 wt%, and Tm = 158.0°C. Furthermore, analysis of the propylene copolymer (b-1) obtained by the second polymerization reaction revealed that the MFR (at 230°C and with a 2.16 kg load) was 3 g / 10 min, the molecular weight distribution (Mw / Mn) was 3.9, and the ethylene content was 11% by weight. Furthermore, (x-1) contained 85% by weight of a propylene polymer (a-1) and 15% by weight of a propylene copolymer (b-1).

[0168] (2) Production of propylene resin (x-2) (i) Production of solid catalyst (c) A 10 L autoclave equipped with a stirring device was thoroughly purged with nitrogen, and 2 L of purified toluene was introduced. 200 g of Mg(OEt)2 and 1 L of TiCl4 were added at room temperature. The temperature was raised to 90°C, and 50 ml of di-n-butyl phthalate was introduced. The temperature was then raised to 110°C, and the reaction was carried out for 3 hours. The reaction product was thoroughly washed with purified toluene. Next, purified toluene was introduced to adjust the total volume to 2 L. 1 L of TiCl4 was added at room temperature, and the temperature was raised to 110°C, and the reaction was carried out for 2 hours. The reaction product was thoroughly washed with purified toluene. Next, purified toluene was introduced to adjust the total volume to 2 L. 1 L of TiCl4 was added at room temperature, and the temperature was raised to 110°C, and the reaction was carried out for 2 hours. The reaction product was thoroughly washed with purified toluene. Finally, toluene was replaced with n-heptane using purified n-heptane to obtain a slurry of the solid components. When a portion of this slurry was sampled and analyzed, the Ti content of the solid component was found to be 2.7% by weight. Next, a 20L autoclave equipped with a stirring device was thoroughly purged with nitrogen, and 100g of the slurry of the solid components was introduced as the solid component. Purified n-heptane was introduced to adjust the concentration of the solid component to 25g / L. 50ml of SiCl4 was added, and the reaction was carried out at 90°C for 1 hour. The reaction product was thoroughly washed with purified n-heptane. Subsequently, purified n-heptane was introduced to adjust the liquid level to 4 L. To this, 30 ml of dimethyldivinylsilane, 30 ml of (i-Pr)2Si(OMe)2, and 80 g of a diluted n-heptane solution of Et3Al were added, and the reaction was carried out at 40°C for 2 hours. The reaction product was thoroughly washed with purified n-heptane, and a portion of the resulting slurry was sampled, dried, and analyzed. The solid components contained 1.2% by weight of Ti and 8.8% by weight of (i-Pr)2Si(OMe)2. Furthermore, prepolymerization was carried out using the solid components obtained above according to the following procedure. Purified n-heptane was introduced into the slurry to adjust the concentration of the solid components to 20 g / L. Next, the slurry was cooled to 10°C, and 10 g of a diluted n-heptane solution of Et3Al was added as Et3Al, followed by the supply of 280 g of propylene over 4 hours. After the supply of propylene was completed, the reaction was continued for another 30 minutes. Then, the gas phase was thoroughly replaced with nitrogen, and the reaction product was thoroughly washed with purified n-heptane. The obtained slurry was removed from the autoclave and vacuum dried to obtain solid catalyst (c). This solid catalyst (c) contained 2.5 g of polypropylene per 1 g of solid component. In addition, the portion of solid catalyst (c) excluding polypropylene contained 1.0 wt% Ti and 8.2 wt% (i-Pr)2Si(OMe)2.

[0169] (ii) Production of propylene resin (x-2) This will be explained using the flow sheet shown in the attached Figure 2. A gas-phase polymerization reactor using two polymerization tanks was employed. The two polymerization tanks 17 and 26 have an inner diameter D: 2100 mm, a length L: 11000 mm, and an internal volume of 40 m³. 3 It is a continuous horizontal vapor-phase polymerization reactor (length / diameter = 5.2) equipped with a stirrer. After replacement inside the reclaimer 17, polypropylene powder from which polymer particles with a particle size of 500 μm or less have been removed was charged. As the solid catalyst (c), 120 g / Hr was used, and a 15 wt% hexane solution of triethylaluminum was continuously supplied so that the molar ratio was 350 with respect to 1 mole of Ti atoms in the solid catalyst (c). Also, hydrogen was supplied so that the ratio of the hydrogen concentration in the reclaimer 17 to the propylene concentration was 0.095, ethylene was supplied so that the ratio of the ethylene concentration to the propylene concentration was 0.020, and propylene monomer was supplied into the reclaimer 17 so that the pressure inside the reclaimer 17 was maintained at 2.10 MPa and the temperature was 61°C. The reaction heat was removed by the heat of vaporization of the raw material propylene supplied from the raw material mixed gas supply pipe 19. The unreacted gas discharged from the reclaimer 17 was withdrawn outside the reactor system through the unreacted gas extraction pipe 20, cooled and condensed, and refluxed to the reclaimer 17 through the recycle gas pipe 18. The propylene polymer (first-stage component: a-2) produced in the reclaimer 17 was continuously withdrawn from the reclaimer 17 through the polymer extraction pipe 21 so that the holding level of the polymer was 45% by volume of the reaction volume, and supplied to the reclaimer 26 in the second polymerization step. Into the reclaimer 26, the polymer from the first polymerization step, hydrogen so that the ratio of the hydrogen concentration in the reclaimer 26 to the propylene concentration was 0.021, ethylene so that the ratio of the ethylene concentration to the propylene concentration was 0.068, and propylene monomer so that the pressure inside the reclaimer 17 was maintained at 2.05 MPa and the temperature was 70°C were respectively supplied into the reclaimer 17. Also, a polymerization activity inhibitor for adjusting the polymerization amount of the propylene copolymer (second-stage component: b-2) was supplied from the pipe 27. The reaction heat was removed by the heat of vaporization of the raw material liquefied propylene supplied from the raw material mixed gas pipe 22. The unreacted gas discharged from the reclaimer 26 was withdrawn outside the reactor system through the unreacted gas extraction pipe 24, cooled and condensed, and refluxed to the reclaimer 26 through the recycle gas pipe 23. The propylene-based resin produced in the second polymerization step was continuously withdrawn from the reclaimer 26 through the polymer extraction pipe 25 so that the holding level of the polymer was 50% by volume of the reaction volume. The withdrawn powder was separated from gases by the gas recovery machine 28, the powder part was withdrawn to the recovery system, and granulated in the granulation system. The production rate of the propylene resin was 9.6 T / Hr, the average residence time in polymerizer 17 was 1.9 Hr, and the average residence time in polymerizer 26 was 1.3 Hr. The catalyst efficiency was calculated by dividing the production rate by the supply rate of solid catalyst (c), and it was found to be 88,900 g-PP / g-catalyst. Furthermore, analysis of the obtained propylene resin (x-2) revealed an MFR of 38.9 g / 10 min and an ethylene content of 5.0 wt%. The propylene polymer (first stage component: a-2) was a propylene-ethylene random copolymer with an MFR of 55 g / 10 min and an ethylene content of 2.4 wt%. The propylene copolymer (second stage component: b-2) was also a propylene-ethylene random copolymer, and its index was calculated to have an MFR of 7.0 g / 10 min and an ethylene content of 10.5 wt%. Furthermore, (x-2) contained 68% by weight of the propylene polymer (a-2) and 32% by weight of the propylene copolymer (b-2).

[0170] (3) Production of propylene resin (x-3) (i) Preparation of solid catalyst (b) In a 50 L tank with a stirrer and a sufficient nitrogen purging, 20 L of dehydrated and deoxygenated n-heptane was introduced, followed by 10 moles of magnesium chloride (MgCl2) and 20 moles of tetrabutoxytitanium [Ti(On-C4H9)4], and the reaction was carried out at 95°C for 2 hours. After the reaction was complete, the temperature was lowered to 40°C, and methylhydropolysiloxane [kinematic viscosity: 20 centistokes (cSt) = 2 × 10⁻⁶] was added. -5 m 2 12 L of [the substance containing / s] was introduced and reacted for 3 hours. The resulting solid component was washed with n-heptane. Next, using the aforementioned stirring tank, 5 L of n-heptane purified in the same manner as above was introduced into the tank, and 3 moles (in terms of Mg atoms) of the solid component synthesized above were introduced. Then, 2.5 L of n-heptane was mixed with 5 moles of tetrachlorosilane (SiCl4) and introduced into a flask at 30°C for 30 minutes, and the mixture was reacted at 70°C for 3 hours. After the reaction was complete, the mixture was washed with n-heptane. Next, 2.5 L of n-heptane was introduced into the agitated tank, mixed with 0.3 moles of phthalate chloride, and the mixture was introduced at 70°C for 30 minutes, followed by a reaction at 90°C for 1 hour. After the reaction was complete, the mixture was washed with n-heptane. Subsequently, 2 L of tetrachlorotitanium (TiCl4) was introduced and the mixture was reacted at 110°C for 3 hours. After the reaction was complete, the mixture was washed with n-heptane to obtain solid component (b1) for preparing solid catalyst (b). The titanium content of this solid component (b1) was 2.0% by weight. Subsequently, 8 L of n-heptane and 400 g of the solid component (b1) synthesized above were introduced into the nitrogen-purged, stirred tank, and 0.6 L of SiCl4 was introduced as component (b2), and the mixture was reacted at 90°C for 2 hours. After the reaction was complete, 0.54 moles of vinyltrimethylsilane [(CH2=CH)Si(CH3)3] as component (b3), 0.27 moles of t-butylmethyldimethoxysilane [(t-C4H9)(CH3)Si(OCH3)2] as component (b4), and 1.5 moles of triethylaluminum [Al(C2H5)3] as component (a5) were sequentially introduced, and the mixture was contacted at 30°C for 2 hours. After contact was complete, the mixture was thoroughly washed with n-heptane to obtain 390 g of solid catalyst (b) mainly composed of magnesium chloride. The titanium content of this solid catalyst (b) was 1.8% by weight.

[0171] (ii) Prepolymerization Using the solid catalyst (b) obtained above, prepolymerization was carried out according to the following procedure. Purified n-heptane was introduced into the slurry to adjust the concentration of solid catalyst (b) to 20 g / L. After cooling the slurry to 10°C, 10 g of a diluted solution of Al(C2H5)3 in n-heptane was added as Al(C2H5)3, and 210 g of propylene was supplied over 4 hours. After the supply of propylene was completed, the reaction was continued for another 30 minutes. Next, the gas phase was thoroughly replaced with nitrogen, and the reaction product was thoroughly washed with purified n-heptane. The resulting slurry was removed from the autoclave and vacuum-dried to obtain a prepolymerized solid catalyst (bb). This solid catalyst component (bb) contained 2.0 g of polypropylene per gram of solid catalyst (bb). Analysis revealed that the portion of the solid catalyst (bb) excluding the polypropylene contained 1.0 wt% Ti and 8.2 wt% (i-C3H7)2Si(OCH3)2.

[0172] (iii) Production of propylene polymer (a-3) Propylene polymerization was carried out using a fluidized bed reactor with an internal volume of 230 L as a continuous reactor. The reactor was maintained at a polymerization temperature of 85°C, a propylene partial pressure of 1.8 MPa (absolute pressure), and hydrogen was continuously supplied as a molecular weight adjuster to achieve a hydrogen / propylene molar ratio of 0.010. Furthermore, 5.25 g / hour of triethylaluminum and 0.50 g of the prepolymerized solid catalyst (bb) described above were supplied to produce a propylene homopolymer at a propylene polymerization rate of 20 kg / hour. The powder polymerized in the reactor was continuously withdrawn into a vessel until the amount of powder in the reactor reached 60 kg. The reaction was stopped by supplying nitrogen gas containing moisture, and a propylene homopolymer was obtained as a propylene-based polymer (a-3). The MFR of this propylene polymer (a-3) was 9 g / 10 min.

[0173] (iv) Production of propylene resin (x-3) 20 parts by weight of the propylene resin (x-2) produced in the operation of (2) were mixed with 80 parts by weight of the propylene homopolymer (a-3) (MFR = 9 g / 10 min) obtained by the above method to obtain the propylene resin (x-3).

[0174] (4) Production of propylene resin (x-4) (i) Preparation of prepolymerization catalyst Chemical treatment of silicate: 3.75 liters of distilled water were slowly added to a 10-liter glass separable flask equipped with a stirring blade, followed by 2.5 kg of concentrated sulfuric acid (96%). At 50°C, 1 kg of montmorillonite (manufactured by Mizusawa Chemical Industries, Ltd., Benclay® SL; average particle size = 50 μm) was dispersed, and the temperature was raised to 90°C and maintained for 6.5 hours. After cooling to 50°C, the slurry was filtered under reduced pressure, and the cake was recovered. 7 liters of distilled water were added to this cake to re-slurry it, and then filtered. This washing operation was repeated until the pH of the washing solution (filtrate) exceeded 3.5. The recovered cake was dried overnight at 110°C under a nitrogen atmosphere. The weight after drying was 707 g. The chemically treated silicate was dried in a kiln dryer.

[0175] Catalyst preparation: 200 g of the dried silicate obtained above was introduced into a 3-liter glass reactor equipped with a stirring blade. 1160 ml of mixed heptane and 840 ml of triethylaluminum heptane solution (0.60 M) were added, and the mixture was stirred at room temperature. After 1 hour, the mixture was washed with mixed heptane to adjust the silicate slurry to 2.0 liters. Next, 9.6 ml of triisobutylaluminum heptane solution (0.71 M / L) was added to the prepared silicate slurry, and the mixture was reacted at 25°C for 1 hour. In parallel, 2177 mg (3 mmol) of [(r)-dichloro[1,1'-dimethylsilylenebis{2-methyl-4-(4-chlorophenyl)-4H-azlenyl}]zirconium] (synthesized according to the examples in Japanese Patent Publication No. 10-226712) was mixed with 870 ml of heptane, to which 33.1 ml of a heptane solution of triisobutylaluminum (0.71 M) was added and the mixture was reacted at room temperature for 1 hour. The resulting reaction product was added to a silicate slurry and stirred for 1 hour to obtain a silicate / metallocene complex slurry.

[0176] Prepolymerization: 2.1 liters of n-heptane were introduced into a 10-liter stirred autoclave, which had been thoroughly purged with nitrogen, and maintained at 40°C. The previously prepared silicate / metallocene complex slurry was then introduced. Once the temperature stabilized at 40°C, propylene was supplied at a rate of 100 g / hour and the temperature was maintained. After 4 hours, the supply of propylene was stopped and the mixture was maintained for another 2 hours. After prepolymerization was complete, the remaining monomer was purged, stirring was stopped, and after standing for about 10 minutes, about 3 liters of the supernatant was decanted. Subsequently, 9.5 ml of a heptane solution of triisobutylaluminum (0.71 M / L) and 5.6 liters of mixed heptane were added to the residue after decanting, and the mixture was stirred at 40°C for 30 minutes. After standing for 10 minutes, 5.6 liters of the supernatant was removed. This procedure was repeated three more times. A component analysis of the final supernatant revealed that the concentration of organoaluminum components was 1.23 mmol / L, and the Zr concentration was 8.6 × 10⁻⁶. -6 The concentration was g / L, and the amount of Zr present in the supernatant relative to the initial charge (by weight) was 0.018% by weight. Subsequently, 17.0 ml of a heptane solution of triisobutylaluminum (0.71 M / L) was added to the residue after decanting, and then the material was dried under reduced pressure at 45°C. This procedure yielded a prepolymerization catalyst (metallocene catalyst) containing 2.16 g of polypropylene per 1 g of catalyst. Using this prepolymerization catalyst, a propylene-ethylene random block copolymer (propylene-based resin (x-4)), which is a multi-stage polymer consisting of propylene-ethylene random copolymers (a-4) and (b-3), was produced according to the following procedure.

[0177] (ii) Propylene resin (x-4): Production of propylene-ethylene random block copolymer A continuous gas-phase polymerization reactor consisting of two horizontal polymerization tanks equipped with stirrers was used. The first reactor (internal volume 40 m³) 3 The pre-polymerization catalyst obtained above was continuously supplied at a rate of 130 g / Hr, and triisobutylaluminum at a rate of 1.0 kg / Hr. The ratio of the hydrogen concentration in the polymerizer to the propylene concentration was 1.6 × 10⁻⁶. -4Hydrogen is added in a molar ratio such that the ratio of ethylene concentration to propylene concentration is 5.8 × 10 -4 Ethylene was supplied to the polymer chamber in the correct molar ratio, and propylene monomer was supplied while maintaining a pressure of 2.25 MPa and a temperature of 62°C, and the first polymerization reaction was carried out. The reaction heat was removed by the heat of vaporization of the liquefied propylene raw material. The propylene-ethylene random copolymer (a-4) produced in the polymerizer was continuously withdrawn so that the polymer retention level reached 45% of the reaction volume, and supplied to the polymerizer for the second polymerization step.

[0178] Analysis of the propylene polymer (a-4) obtained in the first polymerization step revealed that the yield per gram of solid catalyst was 29 kg, the ethylene content was 1.9% by weight, the MFR (at 230°C and with a 2.16 kg load) was 6.9 g / 10 min, and the molecular weight distribution (Mw / Mn) was 2.3.

[0179] Second reactor (internal volume 40 m³) 3 In this process, in addition to the polymer from the first polymerization step, the ratio of the hydrogen concentration in the polymerizer to the propylene concentration is 4.3 × 10⁻⁶. -4 Hydrogen was supplied to the polymerizer in a molar ratio, ethylene was supplied in a molar ratio of ethylene concentration to propylene concentration of 0.36, and propylene monomer was supplied in a polymerizer while maintaining a pressure of 2.2 MPa and a temperature of 70°C, and the second polymerization reaction was carried out. The polymerization yields of each polymer obtained from the first and second polymerization reactions were adjusted by supplying a polymerization activity inhibitor. Furthermore, the reaction heat was removed by the heat of vaporization of the liquefied propylene raw material.

[0180] The propylene-ethylene random block copolymer (x-4) produced in the second polymerization step was continuously withdrawn from the polymerizer so that the polymer retention level was 55% of the reaction volume. Analysis of the obtained propylene-based resin (x-4) revealed that the yield of polymer per gram of solid catalyst was 52 kg, the MFR (at 230°C and with a 2.16 kg load) was 7.2 g / 10 min, the ethylene content was 6.2% by weight, and Tm = 133°C. Furthermore, analysis of the propylene-ethylene random copolymer (b-3) obtained by the second polymerization reaction revealed that the MFR (at 230°C and with a 2.16 kg load) was 7.6 g / 10 min, the molecular weight distribution (Mw / Mn) was 2.4, and the ethylene content was 11.6% by weight. Furthermore, the propylene resin (x-4) contained 55.7% by weight of propylene polymer (a-4) and 44.3% by weight of propylene copolymer (b-3).

[0181] [Examples 1-3 and Comparative Examples 1-4] The propylene resins (x-1) to (x-4) obtained as described above were mixed with an antioxidant, a neutralizing agent, and a nucleating agent (C) in the proportions shown in Table 5, and evaluated. The evaluation results are shown in Table 5. In Comparative Example 4, the heat resistance (HDT) evaluation was significantly inferior, so some evaluations were not performed.

[0182] [Table 3]

[0183] [Table 4]

[0184] [Table 5]

[0185] Examples 1-3 show that the propylene resin (x-1) containing the propylene polymer (A) and propylene copolymer (B) of the present invention was modified by adding a different type of nucleating agent (C). The results demonstrate an excellent balance of heat resistance, rigidity, and impact resistance, and the transparency after heat treatment does not change significantly compared to before treatment, indicating superior performance. Furthermore, the △ gloss indicates that there is almost no bleeding after retort treatment. Examples 1-3 also exhibit excellent odor control. On the other hand, Comparative Example 1, which used a nucleating agent other than nucleating agent (C), has a strong odor, raising concerns about potential problems in food containers, particularly those for Japanese food where flavors are delicate. Comparative Example 2 uses the same additives as Example 3, but does not use the propylene polymer (A) and propylene copolymer (B) of the present invention. From the gloss, it can be seen that bleeding after retort treatment is significant and it is not suitable for practical use. Comparative Example 3 uses the same additive formulation as Example 3, and further adjustments were made to ensure the same balance of heat resistance, rigidity, and impact resistance as Example 3. However, from the gloss, it can be seen that bleeding is suppressed in Example 3. Comparative Example 4 shows that the product has poor heat resistance and there is a risk of deformation after retort processing.

Claims

1. A propylene-based resin composition for retort food containers, characterized by containing a propylene-based polymer (A) that satisfies the following requirements (A1) to (A3), a propylene-based copolymer (B) that satisfies the following requirements (B1) to (B3), a propylene-based resin (X) that satisfies the following requirement (X1), a nucleating agent (C) that satisfies the following requirement (C1), and satisfying the following condition (1). Requirements (A1) The propylene polymer (A) is a metallocene-based propylene polymer. Requirements (A2) The melt flow rate (MFR: 230°C, 2.16 kg load) of the propylene polymer (A) is in the range of 0.5 to 100 g / 10 min. Requirements (A3) The propylene polymer (A) is at least one selected from the group consisting of propylene homopolymers and propylene-α-olefin random copolymers having an α-olefin content of less than 1% by weight. Requirements (B1) Propylene copolymer (B) is a metallocene-based propylene polymer. Requirements (B2) The melt flow rate (MFR: 230°C, 2.16 kg load) of the propylene copolymer (B) is in the range of 0.5 to 80 g / 10 min. Requirements (B3) The propylene copolymer (B) is a propylene-α-olefin random copolymer having an α-olefin content in the range of 3 to 17% by weight. Requirements (X1) The propylene resin (X) contains 75 to 98% by weight of a propylene polymer (A) and 2 to 25% by weight of a propylene copolymer (B) (provided that the total of the propylene polymer (A) and the propylene copolymer (B) is 100% by weight). Requirements (C1) The nucleating agent (C) is at least one selected from the group consisting of nucleating agents represented by the following formulas (1), (2), and (3). R １ (CONHR) ２ ) ａ Equation (1) [In formula (1), R １ R represents a saturated or unsaturated aliphatic polycarboxylic acid residue having 2 to 30 carbon atoms, a saturated or unsaturated alicyclic polycarboxylic acid residue having 4 to 28 carbon atoms, or an aromatic polycarboxylic acid residue having 6 to 18 carbon atoms. ２ [wherein is an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, or a cycloalkyl group or cycloalkenyl group having 3 to 46 carbon atoms, and 'a' is an integer from 2 to 6.] [In formula (2), R １ R is a direct bond, sulfur, an alkylene group or alkylidene group having 1 to 9 carbon atoms, ２ and R ３ Each of these is either the same or different, independently of the others, a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, M is Na, and n is the valency of M. [In formula (3), R １ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ２ and R ３ are the same or different and each independently represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, M represents a metal atom of Group III or Group IV of the periodic table, and X represents HO- when M represents a metal atom of Group III of the periodic table, and represents O= or (HO) ２ -.] Condition (1) The propylene-based resin composition for retort food containers contains 0.01 to 0.6 parts by weight of a nucleating agent (C) per 100 parts by weight of a propylene-based resin (X).

2. The propylene resin composition for retort food containers according to claim 1, wherein the propylene resin (X) further satisfies the following requirement (X2). Requirements (X2) The propylene resin (X) is a continuous polymer.

3. A molded article for retort food containers comprising the propylene-based resin composition for retort food containers described in claim 1 or 2.

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