Polypropylene resin composition, and molded article for medical use

Abstract

To provide a polypropylene resin composition capable of forming a molded article with reduced extractables after sterilization with γ rays.SOLUTION: Disclosed is a polypropylene resin composition which contains a propylene-based polymer, an elastomer, and an NH-type hindered amine compound that has a triazine ring. The elastomer content is 1 mass% or more to 20 mass% or less based on the total amount of the propylene-based polymer and the elastomer. The content of the NH-type hindered amine compound is 100 mass ppm or more to 20,000 mass ppm or less based on the total amount of the propylene-based polymer and the elastomer.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present disclosure relates to a polypropylene resin composition and a medical molded article. [Background technology]

[0002] Polypropylene resin compositions are sometimes used to form medical molded articles such as the outer barrel of a syringe or the housing of a dialyzer (eg, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-31609 A [Patent Document 2] International Publication No. 2016 / 200335 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure relates to a polypropylene resin composition capable of forming a molded article with reduced elution after sterilization with gamma rays. [Means for solving the problem]

[0005] The present disclosure includes the following. [1] A propylene-based polymer, An elastomer; an NH-type hindered amine compound having a triazine ring; Including, the content of the elastomer is 1% by mass or more and 20% by mass or less based on the total amount of the propylene-based polymer and the elastomer, the content of the NH-type hindered amine compound is 100 ppm by mass or more and 20,000 ppm by mass or less based on the total amount of the propylene-based polymer and the elastomer; Polypropylene resin composition. [2] The polypropylene resin composition according to [1], wherein the propylene-based polymer is a copolymer containing monomer units derived from ethylene in a ratio of 0.1 mass% or more and 7.0 mass% or less based on the mass of the propylene-based polymer. [3] The polypropylene resin composition according to [1] or [2], wherein the elastomer comprises a styrene-based elastomer, an ethylene-based elastomer, or a combination thereof. [4] The polypropylene resin composition according to any one of [1] to [3], wherein the NH-type hindered amine compound has a number average molecular weight of 2,000 or more. [5] The polypropylene resin composition according to any one of [1] to [4], comprising two or more kinds of the propylene polymers having different melting points. [6] A medical molded article comprising the polypropylene resin composition according to any one of [1] to [5]. [7] A syringe comprising an outer cylinder having the medical molded article according to [6]. [8] A dialyzer comprising a housing having the medical molded article according to [6]. Effect of the Invention

[0006] A polypropylene resin composition can be provided that can form a molded article that produces little elution after sterilization with gamma rays. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a plan view illustrating one embodiment of a syringe. [Diagram 2] FIG. 1 is a plan view showing one embodiment of a dialyzer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The present invention is not limited to the following examples.

[0009] An example of the polypropylene resin composition includes a propylene-based polymer, an elastomer, and an NH-type hindered amine compound having a triazine ring. The polypropylene resin composition can be used as a molding material for forming a molded body such as a medical molded body.

[0010] The propylene-based polymer is a polymer mainly composed of monomer units derived from propylene. The propylene-based polymer may be a homopolymer of propylene or a copolymer of propylene and another copolymerizable monomer. The propylene-based polymer may have crystallinity.

[0011] The content of the monomer units derived from propylene in the propylene polymer may be 85 mass% or more, 90 mass% or more, 93 mass% or more, 94 mass% or more, or 95 mass% or more based on the mass of the propylene polymer, from the viewpoint of mechanical properties of the molded article. The content of the monomer units derived from propylene may be 100 mass% or less, 99.9 mass% or less, or 98 mass% or less based on the mass of the propylene polymer.

[0012] The copolymerization monomer constituting the propylene-based polymer may be, for example, ethylene or an α-olefin, and the α-olefin may be an α-olefin having a carbon number of 4 to 20. The copolymerization monomer may be any combination selected from ethylene and α-olefins.

[0013] Examples of the α-olefin having 4 to 20 carbon atoms include butene-1, pentene-1, hexene-1, 4-methylpentene-1, heptene-1, octene-1, and decene-1. The propylene-based polymer may be a copolymer of propylene and one or more copolymerization monomers selected from ethylene, butene-1, pentene-1, hexene-1, 4-methylpentene-1, heptene-1, octene-1, and decene-1, and examples thereof include a propylene-ethylene copolymer, a propylene-butene-1 copolymer, a propylene-ethylene-butene-1 copolymer, a propylene-hexene-1 copolymer, and a propylene-ethylene-hexene-1 copolymer. The propylene-based polymer may be at least one selected from a propylene-ethylene copolymer, a propylene-butene-1 copolymer, and a propylene-ethylene-butene-1 copolymer.

[0014] The content of monomer units derived from a copolymerization monomer (e.g., ethylene) in the propylene-based polymer may be 0 mass% or more, 0.1 mass% or more, or 2.0 mass% or more, and may be 15 mass% or less, 10 mass% or less, 7.0 mass% or less, 6.0 mass% or less, or 5.0 mass% or less, based on the mass of the propylene-based polymer.

[0015] The melt flow rate (MFR) of the propylene polymer at a temperature of 230° C. and a load of 21.18 N may be 0.1 g / 10 min or more, 1.0 g / 10 min or more, 2.0 g / 10 min or more, 3.0 g / 10 min or more, 4.0 g / 10 min or more, or 5.0 g / 10 min or more, and may be 100 g / 10 min or less, 50 g / 10 min or less, 40 g / 10 min or less, or 30 g / 10 min or less. When the propylene polymer has an appropriate melt flow rate, good fluidity is easily obtained when the resin composition is extrusion molded or injection molded.

[0016] The polypropylene resin composition may contain two or more propylene polymers having different melting points. For example, the polypropylene resin composition may contain a propylene polymer having a melting point of 160°C or more and a propylene polymer having a melting point of less than 160°C. The difference between the melting points of the two or more propylene polymers may be 5°C or more. The melting points of the propylene polymers herein are values ​​measured by differential scanning calorimetry.

[0017] The elastomer contained in the polypropylene resin composition may be a styrene-based elastomer, an ethylene-based elastomer, or both of them. The polypropylene resin composition may form a phase-separated structure composed of a continuous phase mainly containing a propylene-based polymer and particles (elastomer particles) mainly containing an elastomer dispersed in the continuous phase.

[0018] The styrene-based elastomer is an elastomer containing styrene as a monomer unit. The proportion of the monomer unit derived from styrene in the styrene-based elastomer may be 5% by mass or more, or 10% by mass or more, and may be 60% by mass or less, 50% by mass or less, or 40% by mass or less, based on the total mass of the styrene-based elastomer. The styrene-based elastomer may be a hydrogenated product in which a part or all of the unsaturated bonds derived from the alkadiene monomer or the like (usually excluding the unsaturated bonds of the benzene ring derived from styrene) are converted to saturated bonds by hydrogenation. Hydrogenation tends to improve heat resistance.

[0019] The styrene-based elastomer may be, for example, a block copolymer composed of a polystyrene block and a polyolefin block composed of monomer units derived from an alkadiene having 4 to 10 carbon atoms, or a hydrogenated product thereof. From the viewpoint of compatibility with the propylene-based polymer and impact resistance, the polyolefin block may contain at least one alkadiene of isoprene or butadiene as a monomer unit. In this specification, elastomers containing styrene and ethylene as monomer units are classified as styrene-based elastomers.

[0020] The styrene-based elastomer may be a diblock type copolymer consisting of a polystyrene block and a polyolefin block bonded thereto, or a triblock type copolymer consisting of polystyrene blocks arranged at both ends and a polyolefin block arranged therebetween. The triblock type copolymer can contribute to improving the impact resistance of the molded article.

[0021] Examples of styrene-based elastomers include hydrogenated styrene-butadiene-styrene block copolymers, hydrogenated styrene-isoprene-styrene block copolymers, and hydrogenated styrene-isoprene-butadiene-styrene block copolymers.

[0022] Examples of commercially available styrene-based elastomers include Kraton (trade name) manufactured by Kraton Polymers, Tuftec (trade name) manufactured by Asahi Kasei Corporation, Septon and Hybler (trade names) manufactured by Kuraray, and Dynaron (trade name) manufactured by JSR Corporation.

[0023] Ethylene-based elastomers are copolymers containing ethylene and α-olefins as monomer units. Examples of α-olefins constituting ethylene-based elastomers include propylene, butene-1, pentene-1, hexene-1, heptene-1, and octene-1. Examples of ethylene-based elastomers include ethylene-butene-1 copolymers, ethylene-hexene-1 copolymers, and ethylene-octene-1 copolymers.

[0024] Commercially available ethylene-based elastomers include those manufactured by Sumitomo Chemical Co., Ltd. under the trade names "Excellen" and "Esprene," and those manufactured by Mitsui Chemicals, Inc. under the trade names "Evolue" and "Toughmer."

[0025] The melt flow rate (MFR) of the elastomer at a temperature of 190°C and a load of 21.18N may be 0.1 g / 10 min or more, 0.3 g / 10 min or more, 1 g / 10 min or more, 3 g / 10 min or more, or 5 g / 10 min or more, or 50 g / 10 min or less, 40 g / 10 min or less, 30 g / 10 min or less, 20 g / 10 min or less, or 15 g / 10 min or less. If the MFR of the elastomer is high, the effect of improving impact resistance tends to decrease. If the MFR is too low, the dispersibility of the elastomer in the resin composition decreases, so that the dispersed particle size of the elastomer particles tends to increase and the transparency of the molded product tends to decrease.

[0026] The content of the elastomer in the polypropylene resin composition is 1% by mass or more and 20% by mass or less based on the total amount of the propylene-based polymer and the elastomer. The content of the elastomer may be 2% by mass or more, 3% by mass or more, or 4% by mass or more based on the total amount of the propylene-based polymer and the elastomer, and may be 15% by mass or less, or 10% by mass or less. When the content of the elastomer is within these ranges, color change and elution after sterilization by gamma rays can be particularly significantly suppressed. Here, the "content of the elastomer" means the total amount of the styrene-based elastomer and the ethylene-based elastomer.

[0027] The total amount of the propylene-based polymer and the elastomer in the polypropylene resin composition may be 80 mass% or more, 85 mass% or more, 90 mass% or more, 95 mass% or more, 96 mass% or more, 97 mass% or more, 98 mass% or more, or 99 mass% or more based on the mass of the polypropylene resin composition.

[0028] The NH-type hindered amine compound is a compound having a secondary amino group, which is a hindered amino group, and a triazine ring. The content of the NH-type hindered amine compound in the polypropylene resin composition is 100 ppm by mass or more and 20,000 ppm by mass or less based on the total amount of the propylene-based polymer and the elastomer. The content of the NH-type hindered amine compound may be 200 ppm by mass or more, 300 ppm by mass or more, 400 ppm by mass or more, 500 ppm by mass or more, 600 ppm by mass or more, 700 ppm by mass or more, 800 ppm by mass or more, 900 ppm by mass or more, or 1000 ppm by mass or more, and may be 10,000 ppm by mass or less, 9,000 ppm by mass or less, 8,000 ppm by mass or less, 7,000 ppm by mass or less, 6,000 ppm by mass or less, 5,000 ppm by mass or less, 4,000 ppm by mass or less, 3,000 ppm by mass or less, 2,500 ppm by mass or less, or 2,000 ppm by mass or less.

[0029] The number average molecular weight (Mn) of the NH-type hindered amine compound may be 2000 or more, or 2500 or more, or may be 20000 or less, 15000 or less, 10000 or less, 9000 or less, 8000 or less, 7000 or less, 6000 or less, or 5000 or less. When the number average molecular weight of the NH-type hindered amine compound is within these ranges, the elution after gamma-ray irradiation can be particularly significantly suppressed. The number average molecular weight here is determined by gel permeation chromatography (GPC).

[0030] The NH-type hindered amine compound may be a polymer containing a structural unit containing a secondary amino group which is a hindered amino group and a triazine ring, or may be a polymer containing a main chain containing a triazine ring and a side chain group which is bonded to the main chain and contains a secondary amino group which is a hindered amino group. The NH-type hindered amine compound having a main chain containing a triazine ring may be, for example, a compound (polymer) containing a structural unit represented by the following formula (I). [ka]

[0031] In formula (I), R 1 represents an alkanediyl group having 1 to 20 carbon atoms, and R 2 represents an alkyl group having 1 to 4 carbon atoms, and R 3 represents an alkyl group having 1 to 20 carbon atoms which may be substituted with a secondary amino group; R 4 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, and multiple R 2 may be the same or different. 1 R may be a hexane-1,6-diyl group or an octane-1,8-diyl group. 2 may be a methyl group. 3 may be a group containing a secondary amino group in which R is a hindered amino group, and examples thereof include a group represented by the following formula (10). 5 represents an alkyl group having 1 to 4 carbon atoms (e.g., a methyl group), and multiple R 5 may be the same or different. 4 may be a hydrogen atom, a butyl group, or a tert-octyl group. [ka]

[0032] The polypropylene resin composition may further contain a hindered amine compound other than the NH-type hindered amine compounds explained above.

[0033] The polypropylene resin composition may further contain other components as necessary. Examples of the other components include antioxidants, nucleating agents, neutralizing agents, organic peroxides, weathering agents, flame retardants, antistatic agents, plasticizers, lubricants, and copper inhibitors. The nucleating agent may contain an aromatic phosphate metal salt.

[0034] The polypropylene resin composition can be obtained, for example, by melt-kneading a propylene-based polymer, an elastomer, an NH-type hindered amine compound, and other components as necessary, by a conventional method. The produced polypropylene resin composition may be in the form of pellets for molding. For example, the raw materials are mixed using a mixer such as a tumbler mixer, a Henschel mixer, or a ribbon blender to prepare a mixture, which is then uniformly melt-kneaded using a single-screw extruder, a twin-screw extruder, a Banbury mixer, or the like to obtain a pelletized polypropylene resin composition.

[0035] The molded article obtained by molding the polypropylene resin composition has excellent resistance to sterilization treatments such as radiation sterilization by gamma rays, electron beam sterilization, and high-pressure steam sterilization, and is therefore useful as a medical molded article that comes into contact with various drugs during use. Examples of medical molded articles include the outer cylinder of a syringe and the housing of a dialyzer. The syringe may be a disposable syringe or a pre-filled syringe containing a drug solution that has been previously filled.

[0036] Fig. 1 is a plan view showing one embodiment of a syringe. A syringe 10 shown in Fig. 1 includes an outer cylinder 11, a plunger 13, and a gasket 15 attached to the tip of the plunger 13. The outer cylinder 11 has a mouth portion 11a formed at the tip and a base end portion 11b forming an opening, and the plunger 13 is inserted into the outer cylinder 11 from the opening of the base end portion 11b.

[0037] The outer cylinder 11 is a molded article of a polypropylene resin composition. The thickness, size, etc. of the outer cylinder 11 are appropriately set within normal ranges. The plunger 13 and the gasket 15 can be selected from those usually used in the field of syringes.

[0038] Fig. 2 is a plan view showing one embodiment of a dialyzer. The dialyzer 20 shown in Fig. 2 comprises a cylindrical housing 21, a plurality of hollow fiber membranes 25 arranged in the longitudinal direction of the housing 21 and housed in the housing 21, and headers 22 and 23 attached to both ends of the housing 21. The housing 21 has a dialysate outlet 21a provided at one end and a dialysate inlet 21b provided at the other end. One header 22 has a blood inlet 22a, and the other header 23 has a blood outlet 23a.

[0039] The housing 21 is a molded body of a polypropylene resin composition. When the dialyzer 20 is in use, the inside of the housing 21 is filled with dialysate introduced from the dialysate inlet 21b. The thickness, size, etc. of the housing 21 are appropriately set within normal ranges. The hollow fiber membrane 25 and the headers 22 and 24 can be selected from those normally used in the field of dialyzers for dialysis. EXAMPLES

[0040] The present invention is not limited to the following examples. 1.Raw materials (A) Propylene-based polymer A-1: Propylene-ethylene copolymer (MFR: 22 g / 10 min (230°C, 21.18 N), content of monomer units derived from ethylene: 2.5 mass%, melting point: 152°C) A-2: Propylene-ethylene copolymer (MFR: 6 g / 10 min (230°C, 21.18 N), content of monomer units derived from ethylene: 4.0 mass%, melting point: 142°C) A-3: Propylene homopolymer (MFR: 8g / 10min (230℃, 21.18N), melting point: 164℃) (B) Elastomer B-1: Styrene-based elastomer (hydrogenated styrene-isoprene-styrene block copolymer, Hybra 7311F, manufactured by Kuraray Co., Ltd., content of monomer units derived from styrene: 12% by mass, MFR: 0.5 g / 10 min, (190°C, 21.18 N)) B-2: Styrene-based elastomer (hydrogenated styrene-butadiene-styrene block copolymer, Tuftec H1522, manufactured by Asahi Kasei Corporation, content of monomer units derived from styrene: 30% by mass, MFR: 2g / 10min, (190°C, 21.18N)) B-3: Ethylene-based elastomer (ethylene-butene-1 copolymer, Excellen VL EUL731-M, MFR: 9g / 10min (190℃, 21.18N), density: 895kg / m 3 (High pressure polymerization, manufactured by Sumitomo Chemical Co., Ltd.) B-4: Ethylene-based elastomer (ethylene-butene-1 copolymer, Excellen VL VL700, MFR: 10g / 10min (190℃, 21.18N), density: 905kg / m 3 (High pressure polymerization, manufactured by Sumitomo Chemical Co., Ltd.) (C) NH-type hindered amine compounds C-1: A polymer represented by the following formula (n represents a positive integer) (Chimasorb 2020FDL, manufactured by BASF Japan Ltd., number average molecular weight: 2600 to 3400 g / mol) [ka] C-2: A polymer represented by the following formula (n is a positive integer) (UBINAL 5050H, manufactured by BASF Japan Ltd., number average molecular weight: 3000 to 4000 g / mol) [ka] C-3: A polymer represented by the following formula (n represents a positive integer) (Tinuvin 622 SF, manufactured by BASF Japan Ltd., number average molecular weight: 3100 to 4000 g / mol) [ka] (D) Antioxidants D-1: Tris(2,4-di-tert-butylphenyl)phosphite (Irgafos 168, manufactured by BASF Japan Ltd.) D-2: A mixture of 50% by mass of N,N-dioctadecylhydroxylamine and 50% by mass of tris(2,4-di-tert-butylphenyl)phosphite (Irgastab FS301, manufactured by BASF Japan Ltd.) (E) Nucleating agent E-1: Aromatic phosphate metal salt (a mixture of hydroxyaluminum bis[2,2-methylene-bis(4,6-di-tert-butylphenyl)phosphate] and lithium salt of an aliphatic monocarboxylate having 8 to 20 carbon atoms (ADEKASTAB NA-21, manufactured by ADEKA Corporation)) (F) Neutralizer F-1: Hydrotalcite (Magnesium aluminum hydroxide carbonate, DHT-4C, Kyowa Chemical Industry Co., Ltd.) (G)Organic peroxide G-1: A master batch containing 8 parts by mass of PERHEXA (registered trademark) 25B (manufactured by NOF Corporation) and 92 parts by mass of a propylene-ethylene-butene-1 copolymer having a propylene content of 93.3% by mass, an ethylene content of 2.2% by mass, a butene-1 content of 4.5% by mass, a melt flow rate of 7.0 g / 10 min, and a melting point of 140° C.

[0041] 2. Polypropylene resin composition (pellets) The raw materials shown in Table 1 were placed in a polyethylene bag and mixed uniformly using a tumbler mixer. The mixture in the polyethylene bag was melt-kneaded in a nitrogen atmosphere at a discharge rate of 6 kg / h and 220°C using a single-screw extruder with a screw diameter of 30 mmφ, to obtain pellets of a polypropylene resin composition. Table 1 shows the content of each raw material based on the total mass of the propylene polymer and elastomer. The contents of the propylene polymer and elastomer are shown in mass %, and the contents of the other raw materials are shown in mass ppm.

[0042] 3. Evaluation method (1) Monomer unit content in propylene-ethylene copolymer The IR spectrum of the propylene-ethylene copolymer was measured. From the obtained IR spectrum data, the content of monomer units derived from ethylene (unit: mass%) was determined according to "(i) Method for random copolymers" described on page 616 of Polymer Analysis Handbook (published by Kinokuniya Shoten in 1995). The content of monomer units derived from ethylene was then substituted into the following formula to calculate the content of monomer units derived from propylene in the propylene-ethylene copolymer. Content of monomer units derived from propylene (mass%) = 100 (mass%) - content of monomer units derived from ethylene (mass%)

[0043] (2) Melting point of propylene polymer The melting point (Tm, unit: °C) of the propylene-based polymer was measured using a differential scanning calorimeter (TA Instruments Q2000). Approximately 5 mg of the sample was melted under a nitrogen gas atmosphere (nitrogen gas flow rate 50 ml / min) at 200 °C, held for 5 minutes, and cooled to 0 °C at a rate of 5 °C / min. The sample was then held at 0 °C for 5 minutes and heated to 230 °C at a rate of 5 °C / min. The temperature of the maximum peak of the obtained melting endothermic curve was taken as the melting point (Tm). Using the same differential scanning calorimeter, approximately 5 mg of indium was held at 110°C for 2 minutes under a nitrogen atmosphere (nitrogen gas flow rate 50 ml / min), and then heated at a heating rate of 5°C / min up to 180°C. The melting point (Tm), which is the maximum peak temperature of the obtained melting endothermic curve, was 156.6°C.

[0044] (3) Melt flow rate The melt flow rate (MFR, unit: g / 10 min) of the polypropylene resin composition was measured according to the method of JIS K 7210, condition 14, at a temperature of 230° C. and a load of 21.18 N.

[0045] (4) Stiffness The pellets of the polypropylene resin composition were preheated at 230°C for 5 minutes using a heat press molding machine, and then heated and pressed at 5 MPa for 5 minutes at 230°C to form a resin sheet. The resin sheet was cooled at 30°C for 5 minutes to obtain a resin sheet with a thickness of 1 mm. The stiffness of the obtained resin sheet was measured at a temperature of 23°C according to the method specified in JIS K7106. A high stiffness value means excellent rigidity.

[0046] (5) Extractables Test The pellets of the polypropylene resin composition were preheated at 180°C for 5 minutes in a heat press molding machine, and then heated and pressed at 180°C for 5 minutes at 5 MPa to form a resin sheet. The resin sheet was cooled at 30°C for 5 minutes to obtain a resin sheet with a thickness of 1 mm. A resin sheet having a surface area of ​​150 cm was obtained from the resin sheet. 2A test piece was cut out. The test piece was irradiated with gamma rays at an average dose of 50 kGy at room temperature in an air atmosphere. The test piece was then cut into a size of 5 mm wide and 25 mm long. The cut test piece was washed with ultrapure water and then dried at room temperature. The dried test piece was placed in a hard glass container, 50 mL of ultrapure water was added, and the container was sealed. The hard glass container containing the test piece and ultrapure water was heated at 121°C for 1 hour using a small retort high-pressure steam sterilizer, and then left to cool to room temperature. The liquid in the container after being left was used as the test liquid. A hard glass container containing only ultrapure water was also treated at the same time to prepare a blank test liquid for control.

[0047] The ultraviolet absorption spectrum of the test solution and blank test solution was measured based on the test method described in "(iv) Ultraviolet absorption spectrum" of 7.02 Plastic Pharmaceutical Container Test Method 1.2 Extractables Test of the Japanese Pharmacopoeia, 16th Edition. The maximum absorbance at wavelengths of 220 to 240 nm or 241 to 350 nm was determined from the ultraviolet absorption spectrum. A test piece that satisfies the conditions of a maximum absorbance of 0.08 or less at wavelengths of 220 to 240 nm and a maximum absorbance of 0.05 or less at wavelengths of 241 to 350 nm meets the standards of the Japanese Pharmacopoeia.

[0048] [Table 1]

[0049] The evaluation results are shown in Table 1. It was confirmed that the polypropylene resin compositions of the examples containing a propylene-based polymer, an elastomer, and an NH-type hindered amine compound having a triazine ring had good mechanical properties and could form molded articles with little elution after sterilization by gamma rays. [Explanation of symbols]

[0050] 10...syringe, 11...outer cylinder, 11a...mouth portion, 11b...base end portion, 13...push member, 15...gasket, 20...dialyzer, 21...housing, 21a...dialysis fluid outlet, 21b...dialysis fluid inlet, 22, 23...header, 22a...blood inlet, 23a...blood inlet, 25...hollow fiber membrane.

Claims

1. A propylene-based polymer, An elastomer; an NH-type hindered amine compound having a triazine ring; Including, a content of the elastomer is 1% by mass or more and 20% by mass or less based on the total amount of the propylene-based polymer and the elastomer, the content of the NH-type hindered amine compound is 100 ppm by mass or more and 20,000 ppm by mass or less based on the total amount of the propylene-based polymer and the elastomer; Polypropylene resin composition.

2. 2. The polypropylene resin composition according to claim 1, wherein the propylene-based polymer is a copolymer containing monomer units derived from ethylene in a ratio of 0.1 mass% or more and 7.0 mass% or less based on the mass of the propylene-based polymer.

3. 2. The polypropylene resin composition of claim 1, wherein the elastomer comprises a styrene-based elastomer, an ethylene-based elastomer, or a combination thereof.

4. The polypropylene resin composition according to claim 1, wherein the NH-type hindered amine compound has a number average molecular weight of 2,000 or more.

5. The polypropylene resin composition according to claim 1, comprising two or more of the propylene-based polymers having different melting points.

6. A medical molded article comprising the polypropylene resin composition according to any one of claims 1 to 4.

7. A syringe comprising an outer cylinder having the medical molded article according to claim 6.

8. A dialyzer comprising a housing having the medical molded article according to claim 6.

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