Medical-grade propylene resin composition and molded article thereof

Abstract

To provide a medical-grade propylene resin composition and its molded article that exhibits good transparency after heat treatment. [Solution] A propylene-based resin composition for medical use, 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 requirements (X1) to (X2), 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 medical use and a molded article thereof, and more particularly to a propylene-based resin composition for medical use and a molded article thereof that exhibits good transparency after heat treatment. [Background technology]

[0002] Propylene polymers are used in various medical devices due to their excellent safety and hygiene properties, moldability, mechanical properties, and gas barrier properties. In recent years, they have been increasingly used as alternative containers for ampoules and vials to store drugs and pharmaceutical solutions that require a high level of safety and hygiene, and active development of materials for this application is underway (see, for example, Patent Document 1). Such storage containers must maintain heat resistance during steam sterilization, devitrification resistance, additive extraction resistance, and gas barrier properties against water vapor and oxygen, and the additives used must not interact with the stored drugs or drug solutions. Specifically, it is essential that they satisfy all the test items (pharmacopoeia tests) of polyethylene or polypropylene aqueous injection containers, as specified in 7.02 Test Methods for Plastic Pharmaceutical Containers, 2.1, of the 18th Revised Japanese Pharmacopoeia.

[0003] Furthermore, while propylene homopolymers are preferable in terms of rigidity, heat resistance, and gas barrier properties, and random copolymers with ethylene are preferable in terms of transparency and impact resistance, they are used selectively as appropriate depending on the situation. However, when used in storage containers, it is difficult to achieve sufficient performance in terms of transparency and rigidity with propylene polymers alone, so attempts have been made to optimize essential performance by combining various nucleating agents and neutralizing agents.

[0004] However, when sorbitol-based transparent nucleating agents were used, for example, they did not meet the requirements for additive extraction resistance and pharmacopoeial testing, making them unsuitable for these applications. Furthermore, when aluminum-based nucleating agents were added, the transparency was not sufficiently achieved, and increasing the amount of additive resulted in unsatisfactory results for the ignition residue in pharmacopoeial testing. Examples of medical applications that require passing pharmacopoeia tests include kit formulations such as pre-filled syringes containing pre-pre-filled drug solutions. The consideration of manufacturing kit formulations with pre-filled drug solutions using polypropylene began around the mid-1980s (see, for example, Patent Document 2). Formulations have been proposed in which drug solutions are filled into transparent syringes or transparent containers made of a propylene polymer and a specific nucleating agent, with improved transparency and drug elution properties (see Patent Document 3). However, there has been a demand for further reduction of drug elution, as well as higher transparency and impact resistance of the syringe body. To improve transparency by eliminating devitrification after autoclaving using radiation sterilization and to improve the elution properties of these drug solutions, pre-filled syringes using a specific amine-based antioxidant in polypropylene have been proposed (see Patent Document 4). Although this technology improves drug elution, there was still a demand for higher transparency. On the other hand, as a technology to improve the impact resistance of the syringe body, a technology using a styrene-based elastomer in polypropylene has been proposed (see Patent Document 5). Although this technology achieves both impact resistance and heat resistance, there was a demand for further improvement in transparency. Furthermore, technologies for pre-filled syringes using polypropylene and cyclic polyolefins have also been proposed (see Patent Document 6). While this technology improves the adsorption of drugs to the syringe body, there is still a need for higher transparency. In other words, the current situation is that no molded product has been obtained that possesses sufficient transparency after heat sterilization, has excellent heat resistance and impact resistance, passes pharmacopoeial tests, and is satisfactory as a storage container for pharmaceuticals and chemical solutions. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 1-178541 [Patent Document 2] Japanese Patent Application Laid-Open No. 62-194866 [Patent Document 3] Japanese Patent Application Laid-Open No. 5-222078 [Patent Document 4] Japanese Patent Application Laid-Open No. 2017-31274 [Patent Document 5] Japanese Patent Application Laid-Open No. 2018-134121 [Patent Document 6] Japanese Patent Application Laid-Open No. 2023-34786 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] An object of the present invention is to provide a medical propylene-based resin composition and a molded article thereof having good transparency after heat treatment in view of the above problems. [Means for Solving the Problems]

[0007] As a result of intensive studies, the present inventors have found that a propylene-based resin composition containing a specific propylene-based polymer and a specific propylene-based copolymer in a specific ratio and a specific nucleating agent in a specific amount can solve the above problems, and have completed the present invention.

[0008] That is, the present invention has the following constitution. [1] A propylene-based resin composition for medical use, comprising a propylene-based polymer (A) satisfying the following requirements (A1) to (A3), a propylene-based copolymer (B) satisfying the following requirements (B1) to (B3), a propylene-based resin (X) satisfying the following requirements (X1) to (X2), and a nucleating agent (C) satisfying the following requirement (C1), and satisfying the following condition (1). Requirement (A1) The propylene-based polymer (A) is a metallocene-based propylene polymer. Requirement (A2) The melt flow rate (MFR: 230 ° C., 2.16 kg load) of the propylene-based polymer (A) is in the range of 0.5 to 100 g / 10 min. Requirement (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 (C1) The nucleating agent (C) is the nucleating agent shown in formula (1) below. TIFF2026093133000001.tif54150[In formula (1), 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 elements is either the same or different, independently of the others, a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, where M is Na and n is the valency of M. 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 (X2) The propylene resin (X) is a continuous polymer. Condition (1) The medical-grade propylene resin composition contains 0.01 to 0.6 parts by weight of a nucleating agent (C) per 100 parts by weight of a propylene resin (X). [2] A medical propylene resin molded article comprising the medical propylene resin composition described in [1]. [3] The medical propylene resin molded product according to [2], wherein the medical propylene resin molded product is a syringe for high-temperature sterilization. [4] A kit formulation using the medical propylene resin molded product described in [3]. [5] A pre-filled syringe using a medical propylene resin molded product as described in [3]. [Effects of the Invention]

[0009] The present invention provides a medical-grade propylene resin composition and its molded articles that exhibit good transparency after heat treatment and also have excellent impact resistance, rigidity, and heat resistance. [Brief explanation of the drawing]

[0010] [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]

[0011] One embodiment of the present invention is a medical propylene resin composition characterized by containing a propylene polymer (A) (hereinafter sometimes abbreviated as component (A)) that satisfies requirements (A1) to (A3), a propylene copolymer (B) (hereinafter sometimes abbreviated as component (B)) that satisfies requirements (B1) to (B3), a propylene resin (X) that satisfies requirements (X1) to (X2), 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 resin composition of the present invention"). The details of each item regarding the propylene-based resin composition of the present invention are described below.

[0012] 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).

[0013] (1) Propylene polymer (A) The propylene polymer (A) satisfies the following requirements (A1) to (A3).

[0014] (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 heat treatment.

[0015] 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.

[0016] (i) As metallocene compounds, those disclosed in the following publications are preferably used, for example: 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.

[0017] 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.

[0018] Compounds in which zirconium is replaced with titanium or hafnium can also be used in the same manner. It is also preferable to use a mixture of zirconium compounds and hafnium compounds, etc. 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, hydride groups, etc. Of these, metallocene compounds in which an indenyl group or an azlenyl group is crosslinked with silicon or a gelmyl group are particularly 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) Preferred 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, fluorine-containing organic compounds, and the like.

[0021] (iii) Preferred 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-based (co)polymer (A) include slurry methods using an inert solvent in the presence of the above catalyst, solution methods, gas-phase methods that use substantially no 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-based (co)polymer (A) can be adjusted with hydrogen or other known molecular weight adjusters. Polymerization can be carried out in a continuous or batch reaction, under conditions that are commonly used. Furthermore, the polymerization reaction may be carried out in a single 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 medical propylene resin composition 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 100 g / 10 min, there is a concern that the mechanical strength will decrease. The melt flow rate (MFR) can be easily adjusted by controlling the polymerization conditions of the propylene polymer (A), 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.

[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 polymer (A) used in the propylene resin composition of the present invention may be a propylene homopolymer, a propylene copolymer consisting of propylene and an α-olefin in a content of less than 1% by weight, or a mixture thereof. From the viewpoint of heat resistance, such as during autoclave sterilization, a homopolymer of the propylene polymer (A) is preferable, while from the viewpoint of transparency, a random copolymer consisting of propylene and α-olefin is preferable. When the propylene polymer (A) is a random copolymer using 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, and octene-1. 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. Furthermore, two or more of these propylene polymers may be used in mixture form. In addition, 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.

[0027] For medical applications, sterilization is common, specifically using autoclaving, radiation sterilization, ethylene oxide gas (EOG) sterilization, and ultraviolet sterilization. When autoclaving at 121°C for 20 minutes, propylene homopolymers, block copolymers, or random copolymers with an ethylene content of less than 1% are preferred. Using only random copolymers with a high ethylene content can lead to deformation during autoclaving. Furthermore, autoclaving tends to worsen transparency compared to before sterilization, so materials that do not deteriorate easily are preferable.

[0028] The α-olefin content used in the propylene polymer (A) 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 rigidity decreases, and the likelihood of deformation during autoclave sterilization increases, which may cause deformation. In this specification, propylene and α-olefins are defined as follows: 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 rigidity and barrier properties of the medical-grade propylene-based resin composition of the present invention can be improved. In other words, if the isotactic pentad fraction is less than 0.90, the 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-based propylene polymer, it can suppress bleeding on the surface of the molded product after heat treatment, and the effect of using a metallocene-based propylene polymer as the propylene copolymer (B) is the same as that described in detail in requirement (A1) of the propylene polymer (A).

[0032] The method for producing the propylene copolymer (B) is not particularly limited as long as a metallocene catalyst is used, and any method for producing a propylene copolymer can be used. The metallocene catalyst is the same as that detailed in requirement (A1) of the propylene polymer (A). In the method for producing propylene copolymer (B), if a catalyst other than a metallocene catalyst, such as a Ziegler catalyst, is used, the resulting propylene copolymer will be extremely sticky, have poor moldability, and raise concerns about bleeding and other issues in the final product.

[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 medical propylene resin composition 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. The melt flow rate (MFR) can be easily adjusted by controlling the polymerization conditions of the propylene copolymer (B), 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.

[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 medical propylene resin composition 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-olefins used in the copolymerization of the propylene copolymer (B) include α-olefins having 2 to 20 carbon atoms, excluding propylene, and particularly α-olefins having 2 to 8 carbon atoms. Examples include ethylene, butene-1, hexene-1, octene-1, etc. One or more types of α-olefins may 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. Furthermore, two or more of these propylene polymers may be used in mixture form. Specific examples of propylene copolymers (B) include binary or ternary copolymers obtained 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) The propylene resin (X) contained in the propylene resin composition of the present invention satisfies requirements (X1) and (X2). (3-1) 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 75-98% by weight, preferably 80-95% by weight, and more preferably 85-90% by weight, and the content of propylene copolymer (B) is 2-25% by weight, preferably 5-20% by weight, and more preferably 10-15% 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 medical propylene resin composition 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, the product may become sticky and its heat resistance may decrease. On the other hand, if the proportion of propylene polymer (A) exceeds 98% by weight, the rubber elasticity may become insufficient and the impact resistance may be insufficient.

[0039] (3-2) 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 conditions (X1) and (X2) are as described above.

[0041] (3-2-1) Ethylene content in component (A): [E]A The component (A) produced in the first step is a propylene homopolymer with a relatively high melting point and crystalline properties, or a propylene-ethylene random copolymer with an α-olefin content of less than 1% by weight, preferably with an ethylene content of less than 1% by weight, in order to suppress stickiness of the product (pellets) and to exhibit heat resistance. If the ethylene content is 1% by weight or more, the melting point will be too low, which may worsen the heat resistance of the product. An ethylene content of 0.5% by weight or less is preferable. Furthermore, if the pellets are sticky, they may stick together when stored in the pellet bag, which is undesirable.

[0042] (3-2-2) Ethylene content in component (B): [E]B The component (B) produced in the second step plays the role of a rubber elastic component in the propylene resin (X) and is a necessary component for imparting impact resistance. When ethylene is used as the α-olefin, similarly to the above, the ethylene content of component (B) must be in the range of 3 to 17% by weight, preferably 5 to 15% by weight, and more preferably 7 to 13% by weight, in order to fully exhibit the above effects. When ethylene is used as the α-olefin, by setting the ethylene content within this range, both the impact resistance and transparency of the medical propylene resin composition of the present invention can be kept within a good range. That is, if the ethylene content of component (B) is less than 3% by weight, the impact resistance may not be sufficient, which is undesirable. Also, if it exceeds 17% by weight, the compatibility with component (A) produced in the first step will worsen, which may result in a deterioration of transparency.

[0043] (3-2-3) Proportion of component (A): W(A) and proportion of component (B): W(B) The content ratio of W(A), which is the proportion of component (A) that makes up the propylene resin (X), and W(B), which is the proportion of component (B), must be in the range of W(A) being 75-98% by weight and W(B) being 2-25% by weight. If the proportion of W(A) is less than 75% by weight, even when ethylene is used as the α-olefin, the product may become sticky and its heat resistance may decrease. On the other hand, if the proportion of W(A) exceeds 98% by weight, the rubber elasticity may become insufficient and the impact resistance may be insufficient. Preferably, if the proportion of W(A) is in the range of 80 to 95% by weight, and more preferably 85 to 90% by weight, the product will not become sticky and will have good heat resistance and impact resistance.

[0044] (3-2-4) Regarding the peak of the tanδ curve In the propylene-based resin composition of the present invention, it is preferable that the propylene-based polymer (A) and 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 influenced 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 temperature-loss tangent (tanδ) curve obtained by solid viscoelasticity measurement (DMA) is within the specified range for the peak of the tanδ curve. 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).

[0045] (3-2-5) Identification of [E]A and [E]B and the respective component amounts W(A) and W(B) In the propylene-based resin composition of the present invention, the ethylene content and amount of the propylene polymer (A) and the propylene copolymer (B) can be determined by the material balance during manufacturing, but to determine them more accurately, it is desirable to use the following analysis.

[0046] (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, the ratio of propylene polymer (A) to propylene 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.

[0047] 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.

[0048] (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.

[0049] (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.

[0050] (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.

[0051] (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.

[0052] [Table 1]

[0053] 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, [ ] indicates the fraction of triads. For example, [PPP] is the fraction of PPP triads in all triads. Therefore, [PPP] + [PPE] + [EPE] + [PEP] + [PEE] + [EEE] = 1 (7) is true. Also, k is a constant, I indicates the spectral intensity. For example, I(T ββ ) means the intensity of the peak at 28.7 ppm attributed to T ββ . [[ID=�9]]

[0054] By using the relational expressions (1) to (7) above, the fraction of each triad can be obtained, and further, the ethylene content can be obtained by the following formula. Ethylene content (mol%) = ([PEP] + [PEE] + [EEE]) × 100 In addition, the propylene random copolymer of the present invention contains a small amount of propylene hetero bonds (2,1-bonds and / or 1,3-bonds), thereby generating the following minute peaks.

[0055]

Table 2

[0056] 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.

[0057] (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 food containers of the present invention can both be kept within a good range. That is, 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.

[0058] (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).

[0059] (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.

[0060] 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 is 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.

[0061] (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 well known among manufacturers that a wide molecular weight and crystallinity distribution in propylene-ethylene random copolymers worsens stickiness and bleed-out. In the propylene-based 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.

[0062] 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.

[0063] (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 [wherein is 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.]

[0064] 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 2 This 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.

[0065] 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.

[0066] (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.

[0067] (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, etc., such as trialkylaluminum or diethylaluminum monochloride, halogen or alkoxy-containing alkylaluminum such as diethylaluminum monomethoxide. In addition, aluminoxanes such as methylaluminoxane can also be used. Among these, trialkylaluminum is particularly preferred.

[0068] (v) Formation of catalyst Components (a), (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 olefin or during polymerization of olefin. 1) Contact components (a) and (b) 2) Add component (c) after contacting components (a) and (b) 3) Add component (b) after contacting components (a) and (c) [[ID=?]] 4) Add component (a) after contacting components (b) and (c) In addition, the three components may be contacted simultaneously.

[0069] The amounts of components (a), (b) and (c) used in the present invention are arbitrary. For example, the amount of component (a) used relative 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 relative 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) relative 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.

[0070] It seems there is a typo in the provided text where "? " is shown instead of a proper ID. I've left it as is in the translation. If this was a mistake, please correct the original text for a more accurate translation. 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, during or after contact with each of the above components.

[0071] (vi) Polymerization method (vi-1) Sequential polymerization In manufacturing the propylene resin (X) used in the present invention, component (A) and component (B) are polymerized sequentially. When the propylene resin (X) is simply a random copolymer obtained by copolymerizing propylene with ethylene, if the ethylene content is low, flexibility, impact resistance and transparency are insufficient. If the ethylene content is increased to improve flexibility, impact resistance and transparency, heat resistance deteriorates, making it difficult to satisfy all of these requirements. Therefore, in the present invention, the propylene resin (X) is a block copolymer obtained by sequentially polymerizing components with different ethylene content in the first and second steps, which is necessary in order to balance transparency, flexibility, impact resistance, and heat resistance. Furthermore, in this 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 necessary to use a method in which component (B) is polymerized after component (A). 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.

[0072] 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).

[0073] (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.

[0074] (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. Polymerization pressure varies depending on the selected process, but it can generally be used without any problems within the commonly used pressure range. Specifically, it can be used in the range of 0 to 200 MPa, more preferably 0.1 MPa to 50 MPa. 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.

[0075] (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 it is possible to manufacture a propylene resin (X) that satisfies the desired physical properties so that the effects of the propylene resin composition of the present invention can be realized.

[0076] (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.

[0077] (3-5-2) Component (B) For component (B) to satisfy the requirements of this application, the ethylene content [E]B and preferably T(B) and [η]cxs 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.

[0078] (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 content by increasing the ratio of ethylene supply to propylene increases polymerization activity, but at the same time, activity decay 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).

[0079] (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. Furthermore, the Tg of (a) propylene-ethylene block copolymers that do not adopt a phase-separated structure, as used in the present invention, is influenced by the ethylene content [E]A in component (A), 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 influenced by the ethylene content [E]B in component (B). In other words, Tg reflects the glass transition of the amorphous region, but in the (a) propylene-ethylene block copolymer 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.

[0080] 2. Nucleoforming agent (C) The medical propylene resin composition of the present invention contains a nucleating agent (C) that satisfies the following requirement (C1). Requirements (C1) The nucleating agent (C) is the nucleating agent shown in formula (1) below.

[0081] In the medical propylene resin composition of the present invention, the selectively used nucleating agent (C) is an organophosphate metal salt compound represented by formula (1). TIFF2026093133000004.tif44148

[0082] In equation (1), R 1 These are directly bonded, sulfur, and alkylene or alkylidene groups having 1 to 9 carbon atoms. R 2 and R 3These 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.

[0083] Specific examples of organophosphate metal salt compounds represented by formula (1) 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.

[0084] The medical propylene resin composition of the present invention satisfies the following condition (1). Condition (1) The medical-grade propylene resin composition contains 0.01 to 0.6 parts by weight of a nucleating agent (C) per 100 parts by weight of a propylene resin (X).

[0085] The content of the nucleating agent (C) selectively used in the medical 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, no effect from the nucleating agent (C) is obtained at levels below 0.01 parts by weight, and beyond 0.6 parts by weight, even if the content is increased, the effect of the nucleating agent (C) plateaus, not only preventing further effects but also being economically undesirable.

[0086] In addition to the nucleating agent (C), the medical propylene resin composition of the present invention may use the following nucleating agent (a).

[0087] The nucleating agent (a) is an aromatic phosphate ester represented by the following formula (2).

[0088] TIFF2026093133000005.tif45142[In formula (2), R 1 R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 2 and R 3 Each of the following independently represents either 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; X represents HO- when M represents a metal atom of Group III, and O= or (HO)2- when M represents a metal atom of Group IV.

[0089] Specific examples of aromatic phosphate esters represented by formula (2) 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], 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'-Ethylene-bis(4-methyl-6-t-butylphenyl)phosphate], Hydroxyaluminum-bis[2,2'-methylene-bis(4-ethyl-6-t-butylphenyl)phosphate], Hydroxyaluminum-bis[2,2'-Ethylene-bis(4-ethyl-6-t-butylphenyl)phosphate], Hydroxyaluminum-bis[2,2'-methylene-bis(4-i-propyl-6-t-butylphenyl)phosphate], Examples include hydroxyaluminum-bis[2,2'-ethylene-bis(4-i-propyl-6-t-butylphenyl)phosphate], preferably hydroxyaluminum-bis[2,2'-methylene-bis(4,6-di-t-butylphenyl)phosphate], hydroxyaluminum-bis[2,2'-ethylene-bis(4,6-di-t-butylphenyl)phosphate], and mixtures of two or more of these.

[0090] Aromatic phosphate esters represented by formula (2) are effective when used in combination with organoalkali metal salts. The term "organoalkali metal salt" can refer to at least one organic alkali metal salt selected from the group consisting of alkali metal carboxylates, alkali metal β-diketates, and alkali metal β-ketoacetate salts. Examples of alkali metals constituting the organic alkali metal salt include lithium, sodium, and potassium.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] Commercially available nucleating agents can be used for this purpose. Specifically, ADEKA Corporation's product NA-21 can be cited as an example.

[0095] The content of the nucleating agent (a) is used in the range of 0.005 to 0.15 parts by weight per 100 parts by weight of the propylene resin (X). If the content is less than 0.005 parts by weight, it is difficult to obtain a sufficient effect from the nucleating agent (a), and if it is used in the range of 0.15 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 performance improvement cannot be expected and it is uneconomical. A range of 0.01 to 0.1 parts by weight is preferred.

[0096] In addition to the nucleating agent (C) and the nucleating agent (a) of the present invention, other known nucleating agents such as talc may be added to the medical propylene resin composition of the present invention, as long as they do not significantly impair the effects of the present invention.

[0097] 3. Propylene-based resin composition of the present invention The propylene resin composition of the present invention may contain additives in addition to the propylene resin (X) and nucleating agent (C) described above, as long as the objectives of the present invention are not impaired.

[0098] (1) Neutralizing agent In the propylene resin composition of the present invention, it is desirable to blend a neutralizing agent. Specific examples of the neutralizing agent include metal fatty acid salts such as calcium stearate, zinc stearate, and magnesium stearate, hydrotalcite (trade name: magnesium aluminum composite hydroxide salt represented by the following formula (3) of Kyowa Chemical Industry Co., Ltd.), Mizukarak (lithium aluminum composite hydroxide salt represented by the following formula (4)), and the like. In particular, when used as a member that comes into contact with liquid for a long time, such as a prefilled syringe, a kit preparation, or an infusion bag, hydrotalcite or Mizukarak that does not elute into the contacting liquid is advantageous.

[0099] Mg 1-x Al x (OH)2(CO3) x / 2 ·mH2O … Formula (3) [In formula (3), x is 0 < x ≤ 0.5, and m is a number of 3 or less.]

[0100] [Al2Li(OH)6] n X·mH2O … Formula (4) [In formula (4), X is an inorganic or organic anion, n is the valence of the anion (X), and m is 3 or less.]

[0101] The blending amount of the neutralizing agent selectively used in the medical propylene resin composition of the present invention is preferably in the range of 0.005 to 0.2 parts by weight, more preferably in the range of 0.01 to 0.05 parts by weight, based on 100 parts by weight of the propylene resin (X).

[0102] (3) Other additives In the propylene resin composition of the present invention, in addition to the above-described components, various additives such as various antioxidants, ultraviolet absorbers, and light stabilizers used as stabilizers for the propylene polymer can be blended.

[0103] 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.

[0104] Examples of UV absorbers include 2-hydroxy-4-n-octoxybenzophenone, 2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5-chlorobenzotriazole, and 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole.

[0105] As light stabilizers, n-hexadecyl-3,5-di-t-butyl-4-hydroxybenzoate, 2,4-di-t-butylphenyl-3',5'-di-t-butyl-4'-hydroxybenzoate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, dimethyl-2-(4-hydroxy-2,2,6,6-tetramethyl-1-piperidyl)ethanol condensate, poly{[6-[(1,1,3,3-tetramethylbutyl) Examples of light stabilizers include [mino]-1,3,5-triazine-2,4-diyl][(2,2,6,6-tetramethyl-4-piperidyl)imino]hexamethylene[(2,2,6,6-tetramethyl-4-piperidyl)imino]} and N,N'-bis(3-aminopropyl)ethylenediamine-2,4-bis[N-butyl-N-(1,2,2,6,6-pentamethyl-4-piperidyl)amino]-6-chloro-1,3,5-triazine condensate.

[0106] Furthermore, examples include amine-based antioxidants represented by the following general formulas (5) and (6) that do not discolor under radiation treatment and have 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 (7).

[0107] TIFF2026093133000006.tif29149

[0108] TIFF2026093133000007.tif25146 (In formula (6), R1 and R2 represent alkyl groups having 14 to 22 carbon atoms.)

[0109] TIFF2026093133000008.tif29147

[0110] 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.

[0111] 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.

[0112] (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 mixture of a propylene resin (X) containing a propylene polymer (A) and a propylene copolymer (B), a nucleating agent (C), 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 using a conventional single-screw extruder, twin-screw extruder, Banbury mixer, plastic bender, roll, etc.

[0113] 4. Medical-grade propylene resin molded articles Another embodiment of the present invention is a medical-grade propylene resin molded article comprising the propylene resin composition of the present invention (hereinafter also referred to as "medical-grade molded article of the present invention"). The medical molded articles of the present invention can be obtained by molding the propylene-based resin composition of the present invention by various molding methods such as injection molding, extrusion molding, and blow molding, which are known methods, but injection molding is preferable as it offers high dimensional accuracy and makes it easy to create complex shapes.

[0114] Furthermore, the medical molded article of the present invention is preferably a syringe for high-temperature sterilization. Furthermore, the medical molded articles of the present invention are useful as kit formulations and are suitable for syringes and storage containers filled with drug solutions, and are particularly suitable for pre-filled syringes. That is, one preferred embodiment of the present invention is a kit formulation using the medical molded article of the present invention. Another preferred embodiment of the present invention is a pre-filled syringe using the medical molded article of the present invention.

[0115] A pre-filled syringe is a syringe-shaped preparation that is pre-filled with a drug solution or medication. There are two types: single-chamber type, which is filled with one type of liquid, and double-chamber type, which is filled with two types of medication. Most pre-filled syringes are single-chamber type, but double-chamber type preparations include liquid-powder type preparations consisting of powder and its solvent, and liquid-liquid type preparations consisting of two types of liquid. An example of a single-chamber type preparation is heparin solution. Although the medical molded articles of the present invention are intended for heat sterilization or autoclave sterilization, known sterilization methods such as radiation sterilization, EOG sterilization, ultraviolet sterilization, microwave sterilization, boiling water sterilization, and steam sterilization may also be used. The medical molded articles of the present invention are particularly effective against autoclave sterilization. [Examples]

[0116] 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.

[0117] 1. Measurement Method

[0118] (1) Temperature-induced elution and fractionation (TREF) The TREF measurement method is as follows. [Device] (TREF section) TREF column: 4.3mmφ x 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 (2) Calculation of the amount of each component in the polymer It was calculated using TREF and the method described above. (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. -1The 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.

[0119] (4) MFR Measurements were taken in accordance with JIS K7210, at a heating temperature of 230°C and a load of 21.2N. (5) Haze value Using a 1mm thick sheet, the values ​​before sterilization 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 values ​​measured after sterilization, in accordance with JIS K7105, were used as the post-sterilization values.

[0120] (6) Examination of the 18th Revised Japanese Pharmacopoeia According to the test methods described in Section 7.02, "Test Methods for Plastic Pharmaceutical Containers," specifically Section 2.1, "Aqueous Injectable Containers Made of Polyethylene or Polypropylene," heavy metals, lead, cadmium, ignition residue, foaming, pH, potassium permanganate reducing substances, ultraviolet absorption spectrum, and evaporation residue were measured. However, the sample preparation was performed using a 0.5 mm thick sample with a surface area of ​​1200 cm². 2 Pellets of a corresponding weight were weighed, pressed at 220°C to form sheets, and then shredded into pieces approximately 5 cm long and 0.5 cm wide. After washing with water, they were dried at room temperature. These were placed in a hard glass container with an internal volume of approximately 300 ml, 200 ml of water was added precisely, and the container was sealed with a suitable stopper. After heating in an autoclaver at 121°C for 1 hour, the container was left to cool to room temperature. This internal solution was used as the test solution, and a blank test solution was prepared separately in water using the same method.

[0121] (7) Flexural modulus Measurements were taken at 23°C in accordance with JIS K7171. (8) Charpy impact value Measurements were taken at 23°C using notched specimens in accordance with JIS K7111.

[0122] (9) Visual inspection of bleed after heat treatment After heat treatment of each test specimen, the surface of the sheet was visually inspected for the presence of bleed material. ○: Not visible. ×: Visible. The heat treatment was performed in an oven at 121°C for 30 minutes. (10) HDT (Thermal Distortion Temperature) Measurements were taken in accordance with JIS K7191.

[0123] (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 Calibration curves were created by injecting 0.2 ml of a solution prepared by dissolving each component in o-dichlorobenzene (containing 0.5 mg / ml of BHT) so that each component was at a concentration of 0.5 mg / ml. The calibration curve was a cubic equation obtained by approximating using the least squares method. The following values ​​were 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 GPC measurement conditions were 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: A 1 mg / ml solution of the sample was prepared using o-dichlorobenzene (containing 0.5 mg / ml of BHT), and the sample was dissolved at 140°C for approximately 1 hour.

[0124] 2.Materials used (1) Nuclear agent NA11: ADEKA Stab NA-11 (product name manufactured by ADEKA Corporation): Equivalent to formula (1) of nucleating agent (C).

[0125] (2) Antioxidants IR1076: Irganox 1076 (BASF brand name): Phenolic antioxidant IF168: Irgaphos 168 (BASF brand name): Phosphorus-based antioxidant

[0126] (3) Neutralizing agent DHT4A: DHT-4A (product name manufactured by Kyowa Chemical Industry Co., Ltd.): Neutralizing agent (4) Light stabilizers TNV622: TINUVIN 622SF (BASF Japan product name): Light stabilizer (5) Peroxides PHA25B: Perhexa 25B (product name manufactured by NOF Corporation): Peroxide

[0127] 3. Manufacturing of propylene resin (X) Various propylene-based resins (X) were manufactured using the following procedure.

[0128] (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.

[0129] [Manufacturing Example 2: Manufacturing of Propylene Resin] Propylene-based resins 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.

[0130] 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.

[0131] 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).

[0132] 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).

[0133] (2) Production of propylene resin (x-2) (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.

[0134] (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 (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.

[0135] (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. Furthermore, this propylene polymer (a-3) was used as the propylene resin (x-2).

[0136] (3) Production of propylene resin (x-3) 85 parts by weight of the propylene polymer (a-3) (MFR = 9 g / 10 min) obtained by the above method were mixed with 15 parts by weight of Vistamax VM3000 (b-3) manufactured by ExxonMobil as the propylene copolymer (B) to obtain a propylene resin (x-3). (b-3) was a metallocene-based propylene polymer with an MFR of 8 g / 10 min and an ethylene content of 11% by weight, and was a propylene-ethylene random copolymer.

[0137] (4) Production of propylene resins (x-4) and (x-5) (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.

[0138] (ii) Production of propylene resin (x-5) 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 replacing the contents of the polymerizer 17, polypropylene powder from which polymer particles with a particle size of 500 μm or less had been removed was charged. 120 g / hr of solid catalyst (c) and a 15 wt% hexane solution of triethylaluminum were continuously supplied at a molar ratio of 350 to 1 mole of Ti atoms in the solid catalyst (c). Hydrogen was supplied to the polymerizer 17 so that the ratio of hydrogen concentration to propylene concentration was 0.095, ethylene was supplied so that the ratio of ethylene concentration to propylene concentration was 0.020, and propylene monomer was supplied to the polymerizer 17 so that the pressure inside the polymerizer 17 was maintained at 2.10 MPa and the temperature at 61°C. The heat of reaction was removed by the heat of vaporization of the raw material propylene supplied from the raw material mixed gas supply pipe 19. Unreacted gas discharged from the polymerizer 17 was extracted from the reactor system through the unreacted gas extraction pipe 20, cooled and condensed, and then recirculated back into the polymerizer 17 through the recycled gas pipe 18. The propylene polymer (first stage component: a-4) produced in the polymerizer 17 was continuously extracted from the polymerizer 17 through the polymer extraction pipe 21 so that the polymer retention level was 45% of the reaction volume, and supplied to the polymerizer 26 for the second polymerization step. In the polymerizer 26, the polymer from the first polymerization step, hydrogen was supplied so that the ratio of hydrogen concentration to propylene concentration in the polymerizer 26 was 0.021, ethylene was supplied so that the ratio of ethylene concentration to propylene concentration was 0.068, and propylene monomer was supplied to the polymerizer 17 so that the pressure in the polymerizer 17 was maintained at 2.05 MPa and the temperature at 70°C. A polymerization activity inhibitor was also supplied from piping 27 to adjust the polymerization amount of the propylene copolymer (second stage component: b-2). The reaction heat was removed by the heat of vaporization of the liquefied propylene raw material supplied from the raw material mixed gas piping 22. Unreacted gas discharged from the polymerizer 26 was extracted from the reactor system through the unreacted gas extraction piping 24, cooled and condensed, and then recirculated to the polymerizer 26 through the recycled gas piping 23. The propylene resin produced in the second polymerization step was continuously withdrawn from the polymerizer 26 through the polymer withdrawal pipe 25 so that the polymer retention level was 50% by volume of the reaction volume. The withdrawn powder was separated for gases in the gas recovery machine 28, and the powder portion 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-5) revealed an MFR of 38.9 g / 10 min and an ethylene content of 5.0 wt%. The propylene polymer (first-stage component: a-4) 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-5) contained 68% by weight of a propylene polymer (a-4) and 32% by weight of a propylene copolymer (b-2).

[0139] (v) Manufacturing of propylene resin (x-4) 80 parts by weight of the propylene polymer (a-3) (MFR = 9 g / 10 min) obtained by the above method were added to 20 parts by weight of the propylene resin (x-5) obtained by the above method to obtain propylene resin (x-4).

[0140] [Example 1 and Comparative Examples 1-3] 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.

[0141] [Table 3]

[0142] [Table 4]

[0143] [Table 5]

[0144] Example 1 involves a propylene resin (x-1) containing the propylene polymer (A) and propylene copolymer (B) of the present invention, with a nucleating agent (C) added. It exhibits an excellent balance of heat resistance, rigidity, and impact resistance, and its transparency after heat treatment does not change significantly compared to before treatment. In fact, depending on the conditions, it can be seen that transparency is even better after heat sterilization. Generally, with polypropylene, transparency deteriorates after heat sterilization. Furthermore, it can be seen that there is almost no bleeding after heat treatment. Comparative Example 2 contains a nucleating agent (C) only in the propylene polymer (A). While it exhibits excellent heat resistance and rigidity, it has low impact resistance. Furthermore, its transparency is not as good as that of Example 1, and the transparency after heat treatment under the experimental conditions is worse than that before treatment. Comparative Example 2 is obtained by adding a propylene copolymer (B) to Comparative Example 1, and is an example in which the balance of physical properties is closer to that of Example 1. It has an excellent balance of heat resistance, rigidity and impact resistance, but the transparency after heat treatment is worse compared to before treatment. From this, it can be seen that the propylene resin (X), being a continuous polymer, has excellent transparency after heat sterilization. Comparative Example 3, in which the polymerization catalyst is Ziegler, exhibits excellent heat resistance, rigidity, and impact resistance, but significant bleeding after heat treatment makes it unsuitable for practical use. Note that haze was not measured in Comparative Example 3 due to the significant bleeding.

Claims

1. A propylene-based resin composition for medical use, 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 requirements (X1) to (X2), 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 (C1) The nucleating agent (C) is the nucleating agent shown in formula (1) below. [In formula (1), 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. 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 (X2) The propylene resin (X) is a continuous polymer. Condition (1) The medical-grade propylene resin composition contains 0.01 to 0.6 parts by weight of a nucleating agent (C) per 100 parts by weight of a propylene resin (X).

2. A medical propylene resin molded article comprising the medical propylene resin composition described in claim 1.

3. The medical propylene resin molded body according to claim 2, wherein the medical propylene resin molded body is a syringe for high-temperature sterilization.

4. A kit formulation using the medical propylene resin molded article described in claim 3.

5. A pre-filled syringe using a medical-grade propylene resin molded product as described in claim 3.

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