JP2016121249A - Propylene-based resin composition for medical use and injection molded article thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a propylene-based resin composition for medical use good in mold processability during injection molding, excellent in a balance of rigidity and impact resistance and transparency, especially excellent in impact resistance and low elution property after radiation sterilization and satisfying 6 chemical requirements described in JIS T3210:2011 Sterilized Injection Tube or a heavy metal test, a lead test, a cadmium test, an eluate test described in Pharmaceutical 494, dialysis Type Artificial Kidney Apparatus Approval Standard IV Quality and Test Method of Blood Circuit and an injection molded article obtained by using the same.SOLUTION: There is provided a propylene-based resin composition for medical use, containing 100 pts.wt. of a propylene resin consisting of (A) a propylene (co)polymer which is a propylene single polymer polymerized by a Ziegler Natta catalyst or a propylene copolymer consisting of propylene and α-olefin with the content of less than 1 wt.% and having melt flow rate according to JIS K7210 (230°C, 2.16 kg load) of 0.5 to 100 g/10 min. of 60 to 99 pts.wt. and (B) a propylene-ethylene block copolymer polymerized by the Ziegler Natta catalyst and satisfying properties of (B-i) to (B-iv) of 1 to 40 pts.wt. and 0.005 to 0.6 pts.wt. of a nucleating agent and used by a radiation sterilization treatment.SELECTED DRAWING: None

Description

  The present invention relates to a propylene-based resin composition for medical use and an injection-molded product obtained by using the same, and more specifically, has good moldability at the time of injection molding, balance between rigidity and impact resistance, and transparency. Excellent, especially impact resistance after radiation sterilization, excellent low elution, and 6 chemical requirements described in JIS T3210: 2011 sterilized syringe or Yakusei No. 494 dialysis type artificial kidney device approval criteria The present invention relates to a propylene-ethylene resin composition for medical use that satisfies the heavy metal test, lead test, cadmium test, and eluate test described in IV Blood Circuit Quality and Test Methods after radiation sterilization and an injection-molded product obtained by using the same.

Propylene polymers are excellent in molding processability, mechanical properties, and gas barrier properties, so they are molded by various methods, and like other resins such as polyvinyl chloride and polystyrene, food containers, caps, medical Widely used in various applications such as industrial equipment, medical containers, daily necessities, automobile parts, electrical parts, sheets, films, fibers and the like. Depending on the application, a higher balance of rigidity and impact resistance, transparency, and appearance of low foreign matter are strongly required for the propylene-based polymer or the composition thereof. For example, if the rigidity of the syringe barrel is reduced to improve impact resistance, the product strength of the outer cylinder will be insufficient, the outer cylinder will be crushed during use, and the drug will leak unintentionally from the tip of the syringe needle On the contrary, if the rigidity is increased, the product strength is improved, but the impact resistance is lowered, and there is a concern that the instrument may be damaged during use. Further, when the syringe barrel is stored in a refrigerator, the temperature of the syringe barrel itself is lowered, so that low temperature impact resistance is also required. Furthermore, in order to confirm the bubbles during use, transparency is required, and it is necessary to minimize the appearance of foreign substances that may cause poor appearance and unintended danger in the molded product.
Also in some dialysers, hollow fibers are dried with hot air in some products, so if the product rigidity is low, there is a concern that the product will be deformed during drying, and if the rigidity is high and impact resistance is low, the dialyzer is set in the dialyzer At this time, there is a concern that the D nozzle portion may be broken or may be damaged if the dialyzer is struck with forceps or the like to remove bubbles remaining in the dialyzer before use. In addition, in order to confirm the state of breakage of the hollow fiber, transparency is also required, and it is necessary to minimize the appearance of foreign matters that cause poor appearance and unintended danger in the molded product.

Propylene polymers are propylene homopolymers in terms of rigidity, heat resistance and gas barrier properties, and propylene-ethylene random copolymers in terms of transparency and impact resistance. In this respect, a propylene-ethylene block copolymer is suitable, and is selectively used as appropriate depending on the situation.
However, the propylene homopolymer is not as transparent as the propylene-ethylene block copolymer, and it is difficult to exhibit sufficient performance in terms of impact resistance. A conventional propylene-ethylene random copolymer is excellent in transparency but may not have sufficient impact resistance. Although the propylene-ethylene block copolymer has excellent impact resistance, it has a drawback that it is extremely difficult to impart transparency. In addition, the added elastomer and subsequently copolymerized ethylene-propylene random copolymer can cause stickiness and bleed out of the molded product, and easily cause problems such as drug adsorption and poor appearance. However, it has the disadvantage of inducing problems such as adhesion and contamination to the mold. Patent Document 1 discloses a homopolypropylene having specific physical properties and a propylene-based block copolymer having a copolymer block, and Patent Document 2 sequentially uses a metallocene-based catalyst and sequentially selects random copolymers having different amounts of ethylene. A propylene-ethylene block copolymer obtained by polymerization is disclosed in Patent Documents 3 to 5 in which propylene obtained by sequentially polymerizing blocks (A) and blocks (B) having different physical properties and different ethylene contents. Block copolymers are each disclosed. However, these techniques are not sufficient to obtain an injection molded product having a good balance between rigidity and impact resistance, excellent transparency, and less stickiness and bleed out.

In addition, since the medical propylene-based resin composition is used as a member of a medical instrument, various sterilization resistances performed at the final product stage are required. The sterilization generally performed includes high pressure steam sterilization, ethylene oxide gas sterilization, and radiation sterilization. Radiation sterilization can be divided into sterilization by γ-ray irradiation and sterilization by electron beam irradiation. A characteristic as a medical propylene-based resin composition required for high-pressure steam sterilization is high heat distortion resistance, and a propylene homopolymer is generally used. The medical propylene-based resin composition required for radiation sterilization is characterized by preventing significant resin deterioration due to radiation irradiation and preventing deterioration of elution due to decomposition of the prescribed additive. It is known that irradiation of a propylene-based resin composition with a radiation breaks the tie molecular chain and significantly lowers impact resistance (see, for example, Non-Patent Document 1).
As a method for preventing a decrease in impact resistance due to radiation, a method of blending polyethylene or hydrogenated SBR resistant to radiation sterilization into a propylene polymer is known (for example, see Non-Patent Document 1). In addition, the propylene-type polymer said here is a propylene homopolymer, a propylene-ethylene random copolymer, and a propylene-ethylene block copolymer.
However, since polyethylene stays in the dead space of the hot runner in the molding machine and thermally deteriorates, it crosslinks and gels, so the propylene resin composition blended with polyethylene appears in the molded product as a foreign matter. May be easy to do. This possibility is especially true when the polyethylene to be blended has a large molecular weight, or when the organic peroxide compounded to adjust the molecular weight of the propylene resin composition is normally decomposed during pelletization in a nitrogen atmosphere. If the unreacted material remains in the pellet without reacting, it may become prominent. This is considered to be caused by oxidative degradation in addition to decomposition of the organic peroxide because it is plasticized in an air atmosphere in normal injection molding. Moreover, since hydrogenated SBR has a higher price as a resin than polypropylene, there is a drawback that a propylene-based resin composition cannot be produced at a low cost. On the other hand, as a method for improving the resistance of polypropylene itself to radiation sterilization, there is a method in which propylene and ethylene are copolymerized in a single polymerization tank (see, for example, Non-Patent Document 1). However, the conventional method requires excessive copolymerization of ethylene in order to give excellent resistance to radiation sterilization. On the other hand, the rigidity is significantly reduced, and the rigidity and impact resistance after radiation sterilization are reduced. It was difficult to maintain a balance of sex.

  Furthermore, in order to mold a thin injection molded product typified by a syringe, high fluidity in the mold is required. There is a method of increasing the MFR (melt flow rate) of the propylene-based resin composition in order to enhance the fluidity in the mold, but the molecular weight decreases as the MFR increases, so that the impact resistance, particularly after radiation sterilization Impact resistance is reduced. Therefore, in order to achieve both fluidity in the mold and impact resistance, there has been a conventional method of blending polyethylene or hydrogenated SBS as a modified rubber component with a high MFR propylene polymer. It was difficult to achieve both high fluidity in the mold and impact resistance with the propylene polymer itself without adding a rubber component.

On the other hand, in order to improve the performance of the propylene-based polymer, the performance has been supplemented by blending a nucleating agent.
For example, as a nucleating agent for modifying a propylene-based polymer, a sorbitol-based transparent nucleating agent (see, for example, Patent Document 6) or an organic phosphate-based rigid nucleating agent (for example, improving the transparency and molding processability) Patent Document 7), triaminobenzene-based rigid nucleating agent (see, for example, Patent Document 8) and the like are widely used.

  Molded products using sorbitol nucleating agents are excellent in transparency, and those added with organic phosphoric acid nucleating agents are excellent in low bleed-out properties of nucleating agents, and triaminobenzene-based rigid nucleating agents. The added material is excellent in low bleed-out property, low foreign matter appearance property, low elution property, and transparency. When used in medical applications, it is necessary to formulate with particular attention to the balance between rigidity and impact resistance after sterilization and low elution.

  In addition, it is also known that the impact resistance after radiation sterilization is significantly reduced by blending a nucleating agent with a conventional propylene-based resin composition as compared with those without a nucleating agent (for example, Non-patent document 1).

Furthermore, it is also known that additives in the propylene-based resin composition are decomposed by performing radiation sterilization (see, for example, Non-Patent Documents 2 and 3). Degraded additives tend to bleed out by lowering the molecular weight, particularly affecting the results of the eluate test. In addition, for example, in the case of a syringe, there is a concern that when the medicine is filled in the syringe barrel, the drug effect is affected when the additive which has been decomposed and reduced in molecular weight on the inner surface of the syringe barrel is bleed out. In general, the migration rate of the additive is higher in the amorphous region than in the crystalline phase, so that bleedout due to the decomposition of the additive after radiation sterilization is included in the amorphous region of the propylene polymer. It is thought that when an additive is decomposed, it has an effect. Therefore, it is estimated that the nucleating agent considered to be usually incorporated in the crystal phase of the propylene polymer is hardly affected by bleed out. On the other hand, in order to improve the resistance after radiation sterilization of the propylene-based polymer excluding the propylene homopolymer, when a large amount of ethylene is copolymerized, the degree of crystallinity decreases and the proportion of the crystal phase decreases. For this reason, the nucleating agent that is normally considered to be incorporated into the crystal phase becomes supersaturated with respect to the ratio of the crystal phase and is present in the amorphous phase, which is considered to be affected by radiation irradiation. Further, additive bleedout is believed to have an interaction effect between the additives. This is because the easy bleedout additive or other additives are decomposed by irradiation to reduce the molecular weight to become an easy bleedout product, but other additives or other additives are decomposed by irradiation. And by intermolecular interaction, the other bleed-out additive or other bleed-out product is pulled into the other additive or other additive decomposed by irradiation, or both As a result of the association, the compatibility with the propylene-based polymer is lowered, and it can be considered that bleeding occurs. Intermolecular interactions mentioned here include hydrogen bonds, van der Waals forces, and London dispersion forces.
Furthermore, the influence of radiation irradiation is also received by the propylene-based polymer itself, and the amount and type of the deteriorated product generated changes. This differs depending on whether the irradiation atmosphere is an air atmosphere or a nitrogen atmosphere. Generally, since irradiation is performed in an air atmosphere, various kinds of oxidized deterioration products are generated.
Since these factors are influenced by various factors, it is impossible to elucidate them with current technology. Therefore, the development of medical propylene resin compositions with excellent impact resistance and low elution properties after radiation sterilization is impossible to predict with existing technologies. Types of propylene polymers, nucleating agents It can be developed only by extensive screening such as selection of other additives. Therefore, it has good moldability during injection molding, excellent balance between rigidity and impact resistance, excellent appearance of low foreign matter, and transparency. Especially, medical propylene system with excellent impact resistance and low dissolution after radiation sterilization. It is extremely difficult to develop a resin composition.

JP-A-11-349649 Japanese Patent Laid-Open No. 06-287257 Japanese Patent Laid-Open No. 11-228648 JP-A-11-240929 JP-A-11-349650 JP-A-53-117044 Japanese Patent Laid-Open No. 05-140466 International Publication No. 2011-089133

Radiation processing of polymer: Published April 15, 2000, Rubber Digest Co., Ltd. Food irradiation No. 38 No. 1, No. 2 (2003) p. 11-22 Radiation Physics and Chemistry 75 (2006) p. 87-97

  Therefore, it has good moldability at the time of injection molding represented by products for medical use such as syringes and dialyzers, has a good balance between rigidity and impact resistance, low foreign matter appearance and transparency, especially after radiation sterilization. At present, there is a strong demand for a propylene-based resin composition for medical use that is excellent in impact resistance and low elution.

  The object of the present invention is to solve the above-mentioned drawbacks, while having good molding processability at the time of injection molding, excellent balance between rigidity and impact resistance, excellent transparency, particularly impact resistance after radiation sterilization, Excellent chemical solubility and 6 chemical requirements as described in JIS T3210: 2011 sterilized syringe, or Yakusei No. 494, dialysis artificial kidney device approval criteria, as described in IV blood circuit quality and test method The object is to provide a medical propylene-ethylene resin composition that satisfies the heavy metal test, lead test, cadmium test, and elution test after radiation sterilization, and an injection-molded product thereof.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor, when using a specific amount of a nucleating agent for two types of specific propylene-based polymers, has good molding processability at the time of injection molding, and rigidity. Excellent balance of transparency and impact resistance and transparency, especially impact resistance after radiation sterilization, excellent low elution, and 6 chemical requirements or medicines described in JIS T3210: 2011 sterilized syringe No. 494 Approval Standard for Dialysis Artificial Kidney Device IV Propylene-ethylene resin composition for medical use satisfying heavy metal test, lead test, cadmium test and eluate test described in quality and test method of blood circuit after radiation sterilization As a result, the present invention was completed.

The present invention relates to the following medical propylene-based resin compositions and injection-molded products thereof.
[1] A propylene homopolymer polymerized by a Ziegler-Natta catalyst or a propylene-based copolymer composed of propylene and an α-olefin having a content of less than 1% by weight, JIS K7210 (230 ° C., 2.16 kg load) ) In accordance with a melt flow rate (hereinafter sometimes abbreviated as MFR) of 0.5 to 100 g / 10 min of a propylene-based (co) polymer (A) of 60 to 99 parts by weight, and the following (B -I) to 100 parts by weight of a propylene-based resin composed of 1 to 40 parts by weight of a propylene-ethylene block copolymer (B) polymerized by a Ziegler-Natta catalyst satisfying the characteristics of (B-iv) A medical propylene-based resin composition containing 0.005-0.6 parts by weight of a nucleating agent and used after radiation sterilization treatment.
(Bi) Propylene-ethylene copolymer (b-1) having an ethylene content of 0.1 to 3% by weight and MFR of 10 to 300 g / 10 min, an ethylene content of 5 to 20% by weight, and an MFR of 1 to 1 Propylene-ethylene block copolymer (B) composed of propylene-ethylene copolymer (b-2) at 50 g / 10 min
(B-ii) The weight ratio of the propylene-ethylene copolymer (b-1) to the propylene-ethylene copolymer (b-2) is 90:10 to 60:40.
(B-iii) Propylene-ethylene block copolymer (B) has an ethylene content of 2 to 8% by weight.
(B-iv) MFR ratio (b-1 / b-2) of propylene-ethylene copolymer (b-1) and propylene-ethylene copolymer (b-2) is 1 to 30, and propylene-ethylene The MFR of the block copolymer (B) is 10 to 100 g / 10 min.

[2] The nucleating agent is 0.01 to 0.3 parts by weight of the nucleating agent (A) represented by the following formula (1), 0.01 to 0.3 part by weight of the nucleating agent (B) represented by the following formula (2). 0.2 part by weight, nucleating agent (C) represented by the following formula (3) 0.005 to 0.03 part by weight, and nucleating agent (D) represented by the following formula (4) 0.1-0. The medical propylene-based resin composition according to [1], which is at least one nucleating agent selected from the group consisting of 5 parts by weight.

［式中、Ｒ^１は、直接結合、硫黄又は炭素数１〜９のアルキレン基又はアルキリデン基であり、Ｒ^２及びＲ^３は、同一又は異なって、それぞれ水素原子又は炭素数１〜８のアルキル基であり、ＭはＮａであり、ｎはＭの価数である。］

[Wherein, R ¹ is a direct bond, sulfur, an alkylene group having 1 to 9 carbon atoms or an alkylidene group, and R ² and R ³ are the same or different and each represents a hydrogen atom or an alkyl having 1 to 8 carbon atoms. A group, M is Na, and n is the valence of M. ]

［式中、Ｒ^１は、水素原子又は炭素数１〜４のアルキル基を示し、Ｒ^２及びＲ^３は、同一又は異なって、それぞれ水素原子又は炭素数１〜１２のアルキル基を示し、Ｍは、周期律表第ＩＩＩ族または第ＩＶ族の金属原子を示し、Ｘは、Ｍが周期律表第ＩＩＩ族の金属原子を示す場合には、ＨＯ−を示し、Ｍが周期律表第ＩＶ族の金属原子を示す場合には、Ｏ＝又は（ＨＯ）_２−を示す。］

[Wherein, R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ² and R ³ are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms; Represents a group III or group IV metal atom of the periodic table, X represents HO— when M represents a group III metal atom of the periodic table, and M represents group IV of the periodic table. When a group metal atom is shown, O = or (HO) _2- . ]

［Ｒ_１〜Ｒ_３：ｔ−ブチル］

_[R 1 ~R 3: t- butyl]

[3] The propylene-based resin composition for medical use according to [1] or [2], wherein the sterilization method is sterilized with gamma rays or electron beams of 1 kGy to 60 kGy.
[4] A medical molded article using the propylene-based resin composition according to any one of [1] to [3].
[5] An injection molded product for medical use, wherein the medical molded product according to [4] is a syringe member.
[6] An injection molded product for medical use, wherein the medical molded product according to [4] is an artificial dialysis member.

  The medical propylene-ethylene resin composition of the present invention has good molding processability at the time of injection molding, excellent balance of rigidity and impact resistance, and transparency, particularly impact resistance after radiation sterilization, low elution property 6 and the chemical requirements described in JIS T3210: 2011 sterilized syringe, or the approval of IVD dialysis artificial kidney device IV heavy circuit test described in the quality and test method of IV blood circuit, It has excellent properties of satisfying lead test, cadmium test, and eluate test after radiation sterilization. In addition, JIS T3210: 2011 6 chemical requirements described in sterile syringes and Yakusei No.494 dialysis artificial kidney device approval criteria IV blood circuit quality and test methods described in heavy metal test, lead test, cadmium test In the eluate test, both standards may be satisfied simultaneously, or only one of the standards may be satisfied.

It is a conceptual diagram of artificial dialysis. It is principal part sectional drawing of a dialyzer. It is sectional drawing of a syringe. FIG. 4 is a flow sheet of the continuous horizontal gas phase polymerization apparatus used in the examples.

  Embodiments of the present invention will be described in detail below. However, the description of the constituent elements described below is an example of the embodiments of the present invention, and the present invention is not limited to these contents.

[1] Components of the composition Propylene-based resin (A) Propylene-based (co) polymer The (A) propylene-based (co) polymer used in the medical propylene-based resin composition of the present invention is a propylene homopolymer, a propylene content of 1 wt. It may be a propylene copolymer composed of less than% α-olefin or a mixture thereof.
(A) The propylene-based (co) polymer is preferably a homopolymer from the viewpoint of moldability and the like, and is preferably a random copolymer composed of propylene and an α-olefin from the viewpoint of transparency. Examples of the α-olefin used for copolymerization include α-olefins having 2 to 20 carbon atoms excluding propylene, and examples thereof include ethylene, butene-1, hexene-1, and octene-1. One or more α-olefins copolymerized with propylene may be used. Of these, ethylene and butene-1 are preferred. More preferably, ethylene is suitable. These propylene polymers may be used as a mixture of two or more. Moreover, it is unpreferable from a viewpoint of a moldability (molding cycle) that content of alpha olefin is 1 weight% or more.
Specific examples of the propylene-based copolymer include propylene-ethylene copolymer, propylene-butene-1 copolymer, propylene-hexene-1 copolymer, propylene-octene-1 copolymer, propylene-ethylene. A binary combination of any amount of comonomers, such as a -butene-1 copolymer, a propylene-ethylene-hexene-1 copolymer, a propylene-butene-1-octene-1 copolymer, or the like A terpolymer can be exemplified.

  In medical applications, sterilization is generally performed. Specifically, high-pressure steam sterilization, radiation sterilization, ethylene oxide gas (EOG) sterilization, ultraviolet sterilization, and the like are performed. In the present invention, radiation sterilization is assumed, and radiation sterilization is practically about 10 kGy to 30 kGy. When this treatment is performed, in order to improve the final physical property balance, propylene alone is used. A propylene-based copolymer composed of a coalescence or propylene and an α-olefin having a content of less than 1% by weight is preferred. By increasing the proportion of the propylene-ethylene block copolymer (B), a product having an excellent balance can be obtained.

The α-olefin content used in the propylene-based (co) polymer (A) is less than 1% by weight, preferably less than 0.5% by weight. When the α-olefin content is 1% by weight or more, rigidity is lowered and moldability is deteriorated.
Here, propylene and α-olefin are values measured by ¹³ C-NMR method under the following conditions.
Apparatus: JEOL-GSX270 manufactured by JEOL Ltd.
Concentration: 300 mg / 2 mL
Solvent: Orthodichlorobenzene

In the case where the propylene-based (co) polymer (A) used in the present invention is a propylene homopolymer, the isotactic pentad fraction is preferably 0.90 or more, more preferably 0.94 to 0.98. It is. It is preferable that the isotactic pentad fraction is 0.90 or more because rigidity and moldability are excellent.
Here, the isotactic pentad fraction is a value measured by a proton decoupling method using ¹³ C-NMR.

  The propylene-based (co) polymer (A) used in the present invention has an MFR in the range of 0.5 to 100 g / 10 minutes, preferably 1 to 50 g / 10 minutes, and 2 to 30 g / 10 minutes. Further preferred. When the MFR is less than 0.5 g / 10 min, there is a possibility that molding processability is lowered and it is difficult to obtain a satisfactory product. Moreover, when it exceeds 100 g / 10 minutes, there exists a concern about the fall of mechanical strength.

  As a catalyst used for obtaining the propylene-based (co) polymer (A) used in the present invention, a so-called Ziegler-Natta catalyst in which a titanium compound and an organic aluminum are combined can be used.

  As Ziegler catalysts, transition metal components such as titanium trichloride, titanium tetrachloride, trichloroethoxytitanium, etc., contact materials of the above-mentioned titanium halide compounds and magnesium compounds represented by magnesium halide, and alkylaluminum Compounds or their two-component catalysts with organic metal components such as halides, hydrides, alkoxides, and further, electron-donating compounds containing nitrogen, carbon, phosphorus, sulfur, oxygen, silicon, etc. are added to these components 3 Component-based catalysts can be mentioned.

Propylene-based (co) polymer production methods include slurry methods using an inert solvent, solution methods, gas phase methods that do not substantially use a solvent, or bulk using a polymerization monomer as a solvent in the presence of the above catalyst. Examples thereof include a polymerization method.
For example, in the case of slurry polymerization, it can be carried out in an inert hydrocarbon or liquid monomer such as n-butane, isobutane, n-pentane, isopentane, hexane, heptane, octane, cyclohexane, benzene, toluene, xylene and the like. . 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 can be adjusted with hydrogen or other known molecular weight regulators. The polymerization is carried out by a continuous or batch reaction, and the conditions may be those usually used. Furthermore, the polymerization reaction may be performed in one stage or in multiple stages.

(B) Propylene-ethylene block copolymer The weight ratio of the propylene-ethylene copolymer (b-1) and the propylene-ethylene copolymer (b-2) used in the present invention is in the range of 90:10 to 60:40. And preferably 87:13 to 65:35, more preferably 84:16 to 70:30. When the upper limit of the weight ratio of the propylene-ethylene copolymer (b-1) is 90 or less, the impact resistance after radiation sterilization of the molded article is improved, and when the lower limit is 60 or more, solidification during molding is accelerated. Molding processability is improved.

The MFR of the propylene-ethylene block copolymer (B) is preferably in the range of 10 to 100 g / 10 min, more preferably 25 to 50 g / 10 min.
When the MFR is 10 g / 10 min or more, molding processability is improved due to improved fluidity, and when it is 100 g / 10 min or less, impact resistance is improved. The MFR ratio (b-1 / b-2) of the propylene-ethylene copolymer (b-1) and the propylene-ethylene copolymer (b-2) is preferably in the range of 1 to 30, more Preferably it is 3.5-30, More preferably, it is 5-30, Most preferably, it is 8-30. Improve impact resistance after radiation sterilization when it is above the lower limit of this range, and disperse propylene-ethylene copolymer (b-2) with respect to propylene-ethylene copolymer (b-1) below the upper limit And the transparency is improved. In addition, a method for adjusting MFR by CR (control rheology) using a molecular weight modifier is generally known. However, in the present invention, it is possible to adjust MFR only by polymerization conditions without CR. From the viewpoint of preventing resin burn at the time.
The ethylene content of the propylene-ethylene block copolymer (B) needs to be in the range of 2-8 wt%, preferably 3-7 wt%, more preferably 3-6 wt%, most preferably 4 ~ 6% by weight.
When it is at least the lower limit of this range, the transparency of the molded product and the impact resistance after radiation sterilization are improved. If it is less than or equal to the upper limit, stickiness is reduced due to a decrease in the low crystalline component, and drug adsorption is improved.

The propylene-ethylene copolymer (b-1) used in the present invention satisfies the following characteristics.
Characteristic 1: MFR
The MFR of the propylene-ethylene copolymer (b-1) used in the present invention needs to be in the range of 10 to 300 g / 10 min, preferably 30 to 200 g / 10 min, more preferably 50 to 150 g / 10 min. is there. If it is above the lower limit of this range, the moldability is improved due to the improvement of fluidity, and even when the molded product is molded with a thickness of 2.5 mm or less, the molding orientation is difficult to be applied and impact is applied. In this case, cracks can be prevented from occurring in the molding orientation direction, and those having an upper limit value or less are preferable in terms of economy because the productivity of the resin composition is good and excellent in impact resistance after radiation sterilization of the molded product.
The method for controlling the MFR value is well known, and can be easily adjusted by adjusting the temperature and pressure, which are polymerization conditions, or by controlling the amount of hydrogen added during the polymerization of a chain transfer agent such as hydrogen.

Characteristic 2: Ethylene content The ethylene content of the propylene-ethylene copolymer (b-1) used in the present invention needs to be in the range of 0.1 to 3% by weight, preferably 1.0 to 2.8. % By weight, more preferably 1.5 to 2.6% by weight. If it is at least the lower limit of this range, the transparency of the molded article becomes good and the impact resistance after radiation sterilization is excellent. On the other hand, if it is less than or equal to the upper limit, the crystallization temperature rises and the solidification at the time of molding becomes faster and the molding processability becomes good.
The ethylene content can be adjusted by controlling the monomer composition of propylene and ethylene during polymerization.

The propylene-ethylene copolymer (b-2) used in the present invention satisfies the following characteristics.
Characteristic 1: MFR
The MFR of the propylene-ethylene copolymer (b-2) used in the present invention needs to be in the range of 1 to 50 g / 10 min, preferably 1 to 30 g / 10 min, more preferably 1 to 15 g / 10 min. Most preferably, it is 1-10 g / 10min.
If it is at least the lower limit of this range, the dispersibility in the propylene-ethylene copolymer (A) is improved, and it becomes possible to suppress the generation of fish eyes in the molded product. On the other hand, when the amount is not more than the upper limit, the low crystalline component is less likely to bleed on the surface and the impact resistance after radiation sterilization is improved. In addition, a method for adjusting MFR by CR (control rheology) using a molecular weight modifier is generally known. However, in the present invention, it is possible to adjust MFR only by polymerization conditions without CR. From the viewpoint of preventing resin burn at the time.

Characteristic 2: Ethylene content The ethylene content of the propylene-ethylene copolymer (b-2) used in the present invention needs to be in the range of 5 to 20 wt%, preferably 7 to 15 wt%, more preferably 8 to 13% by weight. When it is at least the lower limit of this range, the impact resistance of the molded product after radiation sterilization is improved. Moreover, while being compatible with a propylene-ethylene copolymer (b-1) as it is below an upper limit, transparency of a molded article becomes favorable, and a propylene-ethylene copolymer (b-2) becomes. By making it difficult to bleed on the surface of the molded product, stickiness and the like are improved.

Further, the propylene-ethylene block copolymer (B) preferably has a soluble content at −15 ° C. by a temperature rising elution fractionation method (TREF) in order to reduce stickiness and the like, and more preferably 9% by weight or less. It is important that the amount is not more than wt%, more preferably not more than 8 wt%, particularly preferably not more than 7 wt%, most preferably not more than 6 wt%. If this soluble content is within this range, the adverse effects on product quality due to stickiness and bleed-out can be suppressed, and powder particles do not flow poorly due to particle aggregation and reactor adhesion during polymer production. A polymer can be produced stably.
In the propylene-ethylene block copolymer (B), the TREF measurement method is specifically performed as follows. A sample is dissolved in o-dichlorobenzene (containing 0.5 mg / ml BHT (2,6-di-t-butyl-p-cresol)) at 140 ° C. to obtain a solution. After this is introduced into a TREF column at 140 ° C., it is cooled to 100 ° C. at a temperature decreasing rate of 8 ° C./min, subsequently cooled to −15 ° C. at a temperature decreasing rate of 4 ° C./min, and held for 60 minutes. Thereafter, -15 ° C o-dichlorobenzene (containing 0.5 mg / ml BHT), which is a solvent, flows through the column at a flow rate of 1 ml / min, and is dissolved in -15 ° C o-dichlorobenzene in the TREF column. The components are eluted for 10 minutes, and then the column is linearly heated to 140 ° C. at a rate of temperature increase of 100 ° C./hour to obtain an elution curve. The TREF evaluation method is well known to those skilled in the art. For example, detailed measurement methods are described in the following documents.
G. Glockner, J. et al. Appl. Polym. Sci. : Appl. Polym. Symp. 45, 1-24 (1990)
L. Wild, Adv. Polym. Sci. 98, 1-47 (1990)
J. et al. B. P. Soares, A .; E. Hamielec, Polymer; 36, 8, 1639-1654 (1995)

In addition, the ratio of the propylene-ethylene copolymers (b-1) and (b-2) in the propylene-ethylene resin composition (B) is obtained from the material balance at the time of polymerization when manufactured by continuous polymerization. In the case of manufacturing by blending, it is a value obtained from each prescription ratio.
Each ethylene content is a value obtained by measurement by ¹³ C-NMR method.

As a catalyst used for obtaining the propylene-ethylene copolymer (b-1) and the propylene-ethylene copolymer (b-2) used in the present invention, a so-called Ziegler in which a titanium compound and an organic aluminum are combined.・ Natta catalyst can be used.
In the present invention, the propylene for medical use has good moldability at the time of injection molding, excellent balance between rigidity and impact resistance, and excellent transparency, especially excellent in impact resistance after radiation sterilization and low elution property and good balance. A resin composition is particularly preferable. For this reason, a Ziegler-Natta catalyst having a broad molecular weight distribution and high stereoregularity is generally preferable to a metallocene catalyst. When the propylene-ethylene copolymer (b-1) and the propylene-ethylene copolymer (b-2) are obtained with a Ziegler-Natta catalyst, the molecular weight distribution is generally wider than that obtained with a metallocene catalyst. As a result, the fluidity in the mold is increased, the injection molding processability is improved, and the composition distribution is widened, so that the propylene-ethylene copolymer (b-1) and the propylene-ethylene copolymer (b- The compatibility of 2) is increased and the impact resistance after radiation sterilization is improved.
Regarding the molecular weight distribution, the value of (weight average molecular weight) / (number average molecular weight), which is an index of the width of the molecular weight distribution, is preferably 2.0 to 8.0, more preferably 2.5 to 7.0, and further Preferably it is 3.0-6.0. When it is at least the lower limit, the resin fluidity during injection molding is excellent. On the other hand, if it is less than or equal to the upper limit, molding orientation is difficult to be applied, and cracking along the molding orientation hardly occurs, and the impact resistance after radiation sterilization is good. Here, the weight average molecular weight and the number average molecular weight are values measured by a gel permeation chromatography (GPC) method.

Regarding the production process of the propylene-ethylene copolymer (b-1) and the propylene-ethylene copolymer (b-2), any process may be used as long as the above-mentioned characteristics are satisfied. The mixture of the copolymer (b-1) and the propylene-ethylene copolymer (b-2) may be produced by any method as long as the above properties are satisfied. In particular, it is preferable to produce a mixture of propylene-ethylene copolymer (b-1) and propylene-ethylene copolymer (b-2) by a two-stage continuous gas phase polymerization method using a horizontal reactor. The reason is that when a mixture of propylene-ethylene copolymer (b-1) and propylene-ethylene copolymer (b-2) is produced by a two-stage continuous polymerization method, it is produced by a bulk or slurry batch polymerization method. This method is costly because the yield of the polymer per unit time and per unit polymerization vessel is lower than that in the gas phase continuous polymerization method. On the other hand, in the two-stage continuous gas phase polymerization method using a gas phase vertical reactor, distribution occurs in the residence time of each catalyst particle in the polymerizer of each stage, so that propylene-ethylene copolymer (b-1) and propylene are produced. -It becomes an aggregate | assembly of the polymer particle | grains which have distribution in the content rate of ethylene copolymer (b-2), and the fault of the quality surface derived from the nonuniformity of this distribution may generate | occur | produce. Further, when the polymerization process of the propylene-ethylene copolymer (b-2) containing a relatively large amount of ethylene in the second stage is carried out by gas phase polymerization using a gas medium, the polymerization amount increases as the polymerization amount in the second stage increases. The adhesiveness of the coalesced particles may increase, and stable operation may be difficult. In addition, when the polymerization heat is not sufficiently cooled, adhesion to the polymerization vessel wall, the stirring blades, or the like may occur. One way to prevent stickiness is to reduce the amount of catalyst that enters the second stage polymerization reactor while the residence time is short. In some cases, such defects as increase in operation and complexity of operation may occur. Therefore, regarding the production process of the mixture of propylene-ethylene copolymer (b-1) and propylene-ethylene copolymer (b-2), the heat of polymerization is removed by using the latent heat of vaporization of liquefied propylene. Rotating around a horizontal axis that makes it possible to produce a high quality propylene-ethylene copolymer (b-1) and a mixture of propylene-ethylene copolymer (b-2) with a narrow residence time distribution Most preferably, it is produced in a two-stage continuous gas phase polymerization process having a horizontal reactor with a stirrer.
When a mixture of propylene-ethylene copolymer (b-1) and propylene-ethylene copolymer (b-2) is produced by the two-stage continuous gas phase polymerization process having the above horizontal reactor, the first stage After the propylene-ethylene copolymer (b-1) is polymerized with the same catalyst particles, the propylene-ethylene copolymer (b-2) is polymerized in the second stage with the same catalyst particles. The copolymer (b-1) and the propylene-ethylene copolymer (b-2) coexist. In that case, the dispersibility of the propylene-ethylene copolymer (b-2) with respect to the propylene-ethylene copolymer (b-1) becomes the best, and when the powder particles are pelletized into a molded product, they are produced separately. The propylene-ethylene copolymer (b-1) pellets and the propylene-ethylene copolymer (b-2) pellets were melt-kneaded with an extruder and then compared with the molded ones in comparison with the molded ones. Since the compatibility between (b-1) and the propylene-ethylene copolymer (b-2) is remarkably good, it is possible to obtain a high-quality molded product resulting from the uniformity of physical properties in the molded product, A product having excellent transparency and excellent impact resistance after radiation sterilization can be obtained.

  The propylene-based (co) polymer (A) is preferably 60 to 99 parts by weight, and the propylene-ethylene block copolymer (B) is preferably in the range of 1 to 40 parts by weight. Further, the propylene-based (co) polymer (A) is The propylene-ethylene block copolymer (B) in the range of 60 to 90 parts by weight is preferably in the range of 10 to 40 parts by weight, and most preferably the propylene-based (co) polymer (A) is 65 to 85 parts by weight of propylene- The ethylene block copolymer (B) is in the range of 15 to 35 parts by weight. Within this range, the balance of rigidity, impact resistance after radiation sterilization, moldability, and transparency is excellent.

2. Nucleating agent The blending amount of the nucleating agent used in the medical propylene-based resin composition of the present invention is 0.005 to 0.6 parts by weight with respect to 100 parts by weight of the propylene-based resin (A) + (B). It is used in the range. If it is 0.005 parts by weight or more, transparency is sufficiently expressed, and if it is 0.6 parts by weight or less, the six chemical requirements described in the JIS T3210: 2011 sterilized syringe, or Yakusei No. 494 No. Dialysis-type artificial kidney device approval criteria IV Heavy circuit test, lead test, cadmium test and eluate test described in quality and test method of blood circuit not only may pass after radiation sterilization but also cost-effective ( This is advantageous in terms of cost and performance.
As such a nucleating agent, nucleating agents (A) to (D) shown below are desirable.
The nucleating agent (A) used selectively is an organophosphate metal salt compound represented by the formula (1).

［式（１）中、Ｒ^１は、直接結合、硫黄又は炭素数１〜９のアルキレン基又はアルキリデン基であり、Ｒ^２及びＲ^３は、水素原子又は炭素数１〜８のアルキル基であり、ＭはＮａであり、ｎはＭの価数である。］

In Expression (1), ^{R 1} represents a direct bond, a sulfur or an alkylene group or alkylidene group having 1 to 9 carbon atoms, ^{R 2} and ^{R 3} is a hydrogen atom or an alkyl group having 1 to 8 carbon atoms , M is Na, and n is the valence of M. ]

Specific examples of the organophosphate metal salt compound represented by the 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, sodium-2,2′-t-octylmethylene-bis- (4,6-di-t-butyl Phenyl) phosphate, sodium-2,2′-methylene-bis- (4-methyl-6-tert-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-tert-butylphenyl) phosphate, sodium-2,2'-methylene-bis- (4,6-di-methylphenyl) phosphate, sodium-2,2'-methylene-bis- Examples thereof include (4,6-di-ethylphenyl) phosphate and a mixture of two or more thereof. Of these, sodium-2,2′-methylene-bis- (4,6-di-t-butylphenyl) phosphate is particularly preferable.
A commercially available product can be used as such a nucleating agent. Specifically, NA-11 manufactured by ADEKA Corporation can be mentioned.

  The blending amount of the nucleating agent (A) used selectively is 0.01 to 0.00 with respect to 100 parts by weight of the propylene-based (co) polymer (A) + propylene-ethylene block copolymer (B). The range of 3 parts by weight is preferable, and the range of 0.01 to 0.2 parts by weight is more preferable. If it is 0.01 part by weight or more, a sufficient effect is obtained, and the range of 0.3 part by weight or less is advantageous from the viewpoint of cost effectiveness (cost / performance).

  The nucleating agent (B) used selectively is an aromatic phosphate ester represented by the formula (2).

［式（２）中、Ｒ^１は、水素原子又は炭素数１〜４のアルキル基を示し、Ｒ^２及びＲ^３は、水素原子又は炭素数１〜１２のアルキル基を示し、Ｍは、周期律表第ＩＩＩ族または第ＩＶ族の金属原子を示し、Ｘは、Ｍが周期律表第ＩＩＩ族の金属原子を示す場合には、ＨＯ−を示し、Ｍが周期律表第ＩＶ族の金属原子を示す場合には、Ｏ＝又は（ＨＯ）_２−を示す。］

[In Formula (2), R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ² and R ³ represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, and M represents a period. Represents a Group III or Group IV metal atom, X represents HO— when M represents a Group III metal atom, and M represents a Group IV metal of the Periodic Table When showing an atom, it shows O = or (HO) _2- . ]

  Specific examples of the aromatic phosphates represented by the 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-tert-butylpheny ) Phosphate], hydroxyaluminum-bis [2,2′-methylene-bis (4-methyl-6-tert-butylphenyl) phosphate], hydroxyaluminum-bis [2,2′-ethylidene-bis (4- Methyl-6-tert-butylphenyl) phosphate], hydroxyaluminum-bis [2,2′-methylene-bis (4-ethyl-6-tert-butylphenyl) phosphate], hydroxyaluminum-bis [2,2 '-Ethylidene-bis (4-ethyl-6-t-butylphenyl) phosphate], hydroxyaluminum-bis [2,2'-methylene-bis (4-i-propyl-6-t-butylphenyl) phosphate] ], Hydroxyaluminum-bis [2,2'-ethylidene-bis (4-i-propyl-6-t- Tilphenyl) phosphate] and the like, preferably 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], and a mixture of two or more of these.

It is effective to use the aromatic phosphates represented by the formula (2) together with an organic alkali metal salt.
The organic alkali metal salt may be at least one organic alkali metal salt selected from the group consisting of alkali metal carboxylates, alkali metal β-diketonates and alkali metal β-ketoacetate salts.
Examples of the alkali metal constituting the organic alkali metal salt include lithium, sodium, and potassium.
Examples of the carboxylic acid constituting the alkali metal carboxylate include acetic acid, propionic acid, acrylic acid, octylic acid, isooctylic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, Ricinoleic acid, 12-hydroxystearic acid, behenic acid, montanic acid, melicic acid, β-dodecylmercaptoacetic acid, β-dodecylmercaptopropionic acid, β-N-laurylaminopropionic acid, β-N-methyl-lauroylaminopropionic acid Aliphatic monocarboxylic acids such as malonic acid, succinic acid, adipic acid, maleic acid, azelaic acid, sebacic acid, dodecanedioic acid, citric acid, butanetricarboxylic acid, butanetetracarboxylic acid and other polyvalent aliphatic carboxylic acids such as naphthene Acid, cyclopentanecarboxylic acid, 1-methyl Cyclopentanecarboxylic acid, 2-methylcyclopentanecarboxylic acid, cyclopentenecarboxylic acid, cyclohexanecarboxylic acid, 1-methylcyclohexanecarboxylic acid, 4-methylcyclohexanecarboxylic acid, 3,5-dimethylcyclohexanecarboxylic acid, 4-butylcyclohexanecarboxylic acid , Cyclooctenecyclohexanecarboxylic acid, cyclohexenecarboxylic acid, cycloaliphatic mono- or polycarboxylic acid such as 4-cyclohexene-1,2-dicarboxylic acid, benzoic acid, toluic acid, xylyl acid, ethylbenzoic acid, 4-t- Aromatic mono- or polycarboxylic acids such as butylbenzoic acid, salicylic acid, phthalic acid, trimellitic acid, pyromellitic acid and the like can be mentioned.
Examples of the β-diketone compound constituting the alkali metal β-diketonate include acetylacetone, pivaloylacetone, palmitoylacetone, benzoylacetone, pivaloylbenzoylacetone, and dibenzoylmethane.
Examples of the β-ketoacetate constituting the alkali metal β-ketoacetate include ethyl acetoacetate, octyl acetoacetate, lauryl acetoacetate, stearyl acetoacetate, ethyl benzoyl acetate, benzoyl acetate lauryl and the like. It is done.
The alkali metal carboxylate, alkali metal β-diketonate, or alkali metal β-ketoacetate salt, which is a component of the organic alkali metal salt, includes the above alkali metal and carboxylic acid, β-diketone compound, or β-ketoacetate, respectively. And can be produced by a conventionally known method. Among these alkali metal salt compounds, alkali metal aliphatic monocarboxylates, particularly lithium aliphatic carboxylates are preferable, and aliphatic monocarboxylates having 8 to 20 carbon atoms are particularly preferable.
A commercially available product can be used as such a nucleating agent. Specific examples include NA-21 manufactured by ADEKA Corporation.

  The blending amount of the nucleating agent (B) used selectively is 0.01 to 0.00 with respect to 100 parts by weight of the propylene-based (co) polymer (A) + propylene-ethylene block copolymer (B). The range of 20 parts by weight is preferable, and the range of 0.05 to 0.15 parts by weight is more preferable. If it is 0.01 part by weight or more, a sufficient effect is obtained, and the range of 0.20 part by weight or less is advantageous from the viewpoint of cost effectiveness (cost / performance).

  The nucleating agent (C) used selectively is a nucleating agent represented by the formula (3).

［Ｒ_１〜Ｒ_３：ｔ−ブチル］
この様な造核剤としては、市販のものを用いることができる。具体的には、ＢＡＳＦ社製 ＸＴ３８６を挙げることができる。
選択的に用いられる造核剤（Ｃ）の配合量は、プロピレン系（共）重合体（Ａ）＋プロピレン−エチレンブロック共重合体（Ｂ）の１００重量部に対し、０．００５〜０．０３重量部の範囲が好ましく、０．０１〜０．０２重量部の範囲がより好ましい。０．００５重量部以上であれば十分な効果が得られ、０．０３重量部以下である範囲は、費用対効果（コスト・パフォーマンス）の点から有利である。

_[R 1 ~R 3: t- butyl]
A commercially available product can be used as such a nucleating agent. Specific examples include XT386 manufactured by BASF.
The blending amount of the nucleating agent (C) used selectively is 0.005 to 0.005 based on 100 parts by weight of the propylene-based (co) polymer (A) + propylene-ethylene block copolymer (B). The range of 03 parts by weight is preferable, and the range of 0.01 to 0.02 parts by weight is more preferable. If it is 0.005 parts by weight or more, a sufficient effect is obtained, and the range of 0.03 parts by weight or less is advantageous from the viewpoint of cost effectiveness (cost / performance).

  The nucleating agent (D) used selectively is a nucleating agent represented by the formula (4).

この様な造核剤としては、市販のものを用いることができる。具体的には、ミリケン社製 ＮＸ８０００を挙げることができる。
選択的に用いられる造核剤（Ｄ）の配合量は、プロピレン系（共）重合体（Ａ）＋プロピレン−エチレンブロック共重合体（Ｂ）の１００重量部に対し、０．１〜０．５重量部の範囲が好ましく、０．２〜０．４重量部の範囲がより好ましい。０．１重量部以上であれば十分な効果が得られ、０．５重量部以下である範囲は、費用対効果（コスト・パフォーマンス）の点から有利である。

A commercially available product can be used as such a nucleating agent. Specific examples include NX8000 manufactured by Milliken.
The blending amount of the nucleating agent (D) used selectively is 0.1 to 0.00 per 100 parts by weight of the propylene-based (co) polymer (A) + propylene-ethylene block copolymer (B). The range of 5 parts by weight is preferable, and the range of 0.2 to 0.4 parts by weight is more preferable. If the amount is 0.1 parts by weight or more, a sufficient effect is obtained, and the range of 0.5 parts by weight or less is advantageous from the viewpoint of cost effectiveness (cost / performance).

  In addition to the nucleating agents (A) to (D), the medical propylene-based resin composition of the present invention includes known nucleating agents such as sorbitol nucleating agents and talc as other nucleating agents. Can be added within a range that does not significantly impair the effect.

3. Neutralizer In the medical propylene-based resin composition of the present invention, it is desirable to add a neutralizer. Specific examples of the neutralizing agent include metal fatty acid salts such as calcium stearate, zinc stearate, and magnesium stearate, hydrotalcite (trade name: DHT-4A, manufactured by Kyowa Chemical Industry Co., Ltd., the following general formula (5) Magnesium aluminum composite hydroxide salt represented by the formula (1), Mizukarak (trade name, lithium aluminum composite hydroxide salt represented by the following general formula (6) manufactured by Mizusawa Chemical Industry Co., Ltd.), and the like. In particular, when used as a member that is in contact with the liquid for a long period of time, such as a prefilled syringe, a kit preparation, or an infusion bag, hydrotalcite or mizucarac that does not elute into the liquid that comes into contact is advantageous.

Mg _1-x Al _x (OH) ₂ (CO ₃ ) _{x / 2} · mH ₂ O (5)
[Wherein x is 0 <x ≦ 0.5, and m is a number of 3 or less. ]

[Al ₂ Li (OH) ₆ ] _n X · mH ₂ O (6)
[Wherein, X is an inorganic or organic anion, n is the valence of the anion (X), and m is 3 or less. ]

  The blending amount of the neutralizing agent selectively used in the medical propylene-based resin composition of the present invention is 0.005 to 0.2 weight with respect to 100 parts by weight of the propylene-based polymer (A) + (B). The range of parts is preferable, and the range of 0.01 to 0.05 parts by weight is more preferable.

4). Lubricant In the medical propylene-based resin composition of the present invention, a lubricant can be blended. Examples of the lubricant include known lubricants, but butyl stearate and silicone oil are preferable, and silicone oil is particularly preferable.
Specific silicone oils include dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrodienepolysiloxane, α-ωbis (3-hydroxypropyl) polydimethylsiloxane, polyoxyalkylene (C ₂ -C ₄ ) dimethylpolysiloxane. And a polyorgano (C ₁ -C ₂ alkyl group and / or phenyl group) siloxane and polyalkylene (C ₂ -C ₃ ) glycol condensate. Of these, dimethylpolysiloxane and methylphenylpolysiloxane are preferred. These lubricants may be used alone or in combination.
When silicone such as dimethylpolysiloxane is added, not only can scratches that occur during molding be prevented, but also burns that can occur in cylinders and hot runners can be prevented.

  The blending amount of the lubricant selectively used in the medical propylene-based resin composition of the present invention is 0.001 to 0.5 parts by weight with respect to 100 parts by weight of the propylene-based polymer (A) + (B). Preferably, 0.01-0.15 weight part is more preferable, and 0.03-0.1 weight part is especially preferable. If it is 0.001 part by weight or more, a sufficient effect can be expected, and the range of 0.5 part by weight or less is advantageous from the viewpoint of cost effectiveness (cost / performance).

5. Other Additives In the medical propylene resin composition of the present invention, in addition to the components described above, various antioxidants, ultraviolet absorbers, light stabilizers and the like used as stabilizers for propylene polymers, etc. Additives can be blended.

  Specifically, as the antioxidant, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphite, di-stearyl-pentaerythritol-di-phosphite, bis ( 2,4-di-t-butylphenyl) pentaerythritol-diphosphite, tris (2,4-di-t-butylphenyl) phosphite, tetrakis (2,4-di-t-butylphenyl) -4 Phosphorous antioxidants such as 4,4'-biphenylene-diphosphonite, tetrakis (2,4-di-t-butyl-5-methylphenyl) -4,4'-biphenylene-diphosphonite, 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-tert-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate Phenolic antioxidants such as di-stearyl-ββ'-thio-di-propionate, di-myristyl-ββ'-thio-di-propionate, di-lauryl-ββ'-thio-di-propionate An antioxidant etc. are mentioned.

  Examples of the ultraviolet absorber include 2-hydroxy-4-n-octoxybenzophenone, 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl) -5-chlorobenzotriazole, 2- (2 And ultraviolet absorbers such as' -hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole.

  Examples of the light stabilizer include 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) succinate ) Ethanol condensate, poly {[6-[(1,1,3,3-tetramethylbutyl) amino] -1,3,5-triazine-2,4diyl] [(2,2,6,6- Tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]}, N, N′-bis (3-aminopropyl) ethylenediamine-2,4- Bis [N-butyl-N- ( , Mention may be made of a light stabilizer such as 2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate.

  Furthermore, amine-based antioxidants represented by the following general formula (7) and the following general formula (8), which have no discoloration and good NOx gas discoloration resistance by radiation treatment, and 5,7-di-t-butyl-3 Examples include lactone antioxidants such as-(3,4-di-methyl-phenyl) -3H-benzofuran-2-one and vitamin E antioxidants such as the following general formula (9).

  In addition, an antistatic agent, a slip agent, a dispersant such as a fatty acid metal salt, a dye, a pigment, polyethylene, an olefin-based elastomer, and the like can be blended within a range that does not impair the object of the present invention.

[2] Method for Producing Medical Propylene Resin Composition The medical propylene resin composition of the present invention comprises (A) + (B) propylene polymer and nucleating agent, preferably selectively used. After mixing at least one mixture of the nucleating agents (A) to (D) and, if necessary, other additives into a Henschel mixer (trade name), a super mixer, a ribbon blender, etc., It can be obtained by melt-kneading in a temperature range of 190 to 260 ° C. with an ordinary single-screw extruder, twin-screw extruder, Banbury mixer, plastic bender, roll or the like.

[3] Medical molded product The medical molded product of the present invention is obtained by molding the above-mentioned medical propylene-based resin composition by various molding methods such as injection molding, extrusion molding, and blow molding, which are known methods. However, an injection molding method with high dimensional accuracy and easy to make a complicated shape is desirable.
The medical molded article of the present invention is useful as a syringe member or an artificial dialysis member, and is particularly suitable for a syringe member or an artificial dialysis member that is sterilized by radiation.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by these description. In each Example and Comparative Example, the physical properties used were measured by the following methods, and the following were used as propylene-based polymers, nucleating agents, and other additives (neutralizing agents, lubricants).

(1) Calculation of ethylene content
^The ethylene content was calculated from the measured value measured by ¹³ C-NMR method.

(2) MFR: Measured according to JIS K7210 at a heating temperature of 230 ° C. and a load of 21.2 N.

(3) Haze value: Measured according to JIS K7136 using a sheet piece having a thickness of 1 mm.

(4) JIS T3210: 2011 Sterilized syringe barrel 6 Chemical requirements The chemical requirements were tested by the following method with reference to this standard.
(A) Production of 100 mm × 120 mm × 1 mmt press sheet A spacer from which a press sheet of 100 mm × 120 mm × 1 mmt was obtained was placed between 150 mm × 150 mm × 3 mmt aluminum plates, and a predetermined amount of pellets was placed in the frame of the spacer. Thereafter, using a heating press heated to 230 ° C., the pellets were melted in a heating press without applying pressure for the first 7 minutes, and then a pressure of 100 kg / cm ² was applied for 3 minutes. Thereafter, the sample was quickly transferred to a cooling press at 30 ° C., and the sample was cooled by applying a pressure of 150 kg / cm ² for 2 minutes. Thereafter, the press sheet was peeled off from the aluminum plate and the spacer and taken out.
(B) Preparation of test piece for eluate test The press sheet prepared in (a) was equally divided into four by scissors, and four sheets of 60 mm × 50 mm × 2 mmt were collected. Thereafter, the surface of the sheet and the cut surface were washed with distilled water and dried at room temperature to obtain a test piece for the eluate test.
(C) Radiation sterilization of the test piece After irradiating the test piece with γ-rays of 25 kGy (average dose) in an air atmosphere at room temperature, the room temperature is 23 ° C. ± 0.5 ° C. and the relative humidity is 50 ± 5%. Adjusted for 2 weeks.
(D) Preparation of test liquid 250 ml of distilled water was put into a 500 ml borosilicate glass beaker washed with distilled water and dried at room temperature. Four test pieces (60 mm × 50 mm × 2 mmt) prepared for the eluate test prepared in (C) were put therein and immersed in water. At that time, no bubbles remained on the surface of the test piece. And after sealing the beaker with aluminum foil and keeping at 37 degreeC for 8 hours in a thermostat, the test piece was taken out and it was set as the test liquid.
(E) pH test and dissolution metal test The test was performed in accordance with the method described in JIS T3210: 2011. The blank test solution was distilled water, and the eluted metal was analyzed by the primitive spectrophotometry.
The standard of each test result is as follows.
(I) ΔpH: The difference in pH between the test solution and the blank test solution is 1 or less. (Ii) Elution metal: The total of lead, zinc, and iron is 5 mg / L or less, and the cadmium measurement value of the test solution is the blank test solution. When corrected with the measured cadmium value, the cadmium content of the test solution is 0.1 mg / L or less.

(5) Yakuhin No.494 Dialysis Type Artificial Kidney Approval Criteria IV Blood Circuit Quality and Testing Currently, “Yakuhoku No.494 Dialysis Type Artificial Kidney Approval Criteria” is “Abolition of Notification”. Since this test is a standard for confirming chemical safety in this application, the test was conducted.
The heavy metal test, lead test, and cadmium test were conducted using pellets in accordance with the operation method of the approval standard. The pellets used in the test were sterilized by irradiation with γ-rays of 25 kGy (average value) two weeks prior to the test, and for two weeks in a constant temperature room at 23 ° C. ± 0.5 ° C. and a relative humidity of 50 ± 5%. The state is adjusted.
In addition, the eluate test shall be conducted in accordance with the quality and test method of the V dialyzer within the approval criteria. Referring to the eluate test described in the support and blood connection tube, 150 ml of water was added to 15 g of the pellet, and then an extraction test was performed at 70 ° C. for 1 hour. The test was conducted in compliance. The pellets used in the test were sterilized by irradiation with γ-rays of 25 kGy (average value) two weeks prior to the test, and for two weeks in a constant temperature room at 23 ° C. ± 0.5 ° C. and a relative humidity of 50 ± 5%. The state is adjusted.
The standard of each test result is as follows.
4). Heavy metal test: 10 μg / g or less Lead test: 1 μg / g or less Cadmium test: 1 μg / g or less Elution test (i) Appearance: colorless and transparent, no foreign matter (ii) Abalone: Disappears within 3 minutes (iii) ΔpH: Difference from blank is 1.5 or less (iv) Zinc: Standard solution (0.5 μg / g ) And below (v) Potassium permanganate (KMnO ₄ ) reducing substance: difference in potassium permanganate consumption from the standard solution is 1.0 ml or less (vi) evaporation residue: 1.0 mg or less (vii) UV absorption spectrum (UV) 220-350 nm: 0.1 or less *) Currently, “Yakuhatsu No. 494 dialysis artificial kidney device approval criteria” is “Abolition of notification”, but this test is a chemical for this application. The test is conducted because it is a guideline for safety confirmation.

(6) Flexural modulus: Measured at 23 ° C. according to JIS K7203 “Bending test method of hard plastic”.

(7) Charpy impact strength: measured at 23 ° C. according to JIS K7111. In addition, it measured with the test piece which was unsterilized and radiation-sterilized on the following conditions.
* After irradiating the test piece with 25 kGy (average dose) of γ rays in an air atmosphere at room temperature, the condition was adjusted for 2 weeks in a thermostatic chamber at room temperature of 23 ° C. ± 0.5 ° C. and relative humidity of 50 ± 5%.

(8) Deflection temperature under load (0.45 MPa): Measured according to JIS K7191.

2. Materials used (1) Propylene-based (co) polymer (A)
Propylene homopolymer (HPP1): Novatec MA3Q (trade name, manufactured by Nippon Polypro Co., Ltd.), catalyst: Ziegler catalyst, MFR: 10 g / 10 min, isotactic pentad fraction 0.96 (by ¹³ C-NMR Measurement).

(2) Propylene-ethylene block copolymer (B)
<Production Example 1 (PP-1)>
(I) Production of Solid Catalyst Component (A) A 10 L autoclave equipped with a stirrer was sufficiently substituted with nitrogen, and 2 L of purified toluene was introduced. To this, 200 g of Mg (OEt) ₂ and 1 L of TiCl ₄ were added at room temperature. The temperature was raised to 90 ° C. and 50 ml of di-n-butyl phthalate was introduced. Thereafter, the temperature was raised to 110 ° C. to carry out a reaction for 3 hours. The reaction product was thoroughly washed with purified toluene. Subsequently, the refined toluene was introduce | transduced and the whole liquid quantity was adjusted to 2L. 1 L of TiCl ₄ was added at room temperature, the temperature was raised to 110 ° C., and the reaction was performed for 2 hours. The reaction product was thoroughly washed with purified toluene. Subsequently, the refined toluene was introduce | transduced and the whole liquid quantity was adjusted to 2L. 1 L of TiCl ₄ was added at room temperature, the temperature was raised to 110 ° C., and the reaction was performed for 2 hours. The reaction product was thoroughly washed with purified toluene. Furthermore, using purified n-heptane, toluene was replaced with n-heptane to obtain a solid component slurry. When a part of this slurry was sampled and analyzed, the Ti content of the solid component was 2.7% by weight.
Next, a 20 L autoclave equipped with a stirrer was sufficiently replaced with nitrogen, and 100 g of the solid component slurry was introduced as a solid component. Purified n-heptane was introduced to adjust the solid component concentration to 25 g / L. 50 ml of SiCl ₄ was added and a reaction was performed at 90 ° C. for 1 hr. The reaction product was thoroughly washed with purified n-heptane.
Thereafter, purified n-heptane was introduced to adjust the liquid level to 4 L. To this, 30 ml of dimethyldivinylsilane, 30 ml of (i-Pr) ₂ Si (OMe) ₂ and 80 g of Et ₃ Al in an n-heptane diluted solution were added as Et ₃ Al, and a 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. As a result, the solid component was 1.2% by weight of Ti, (i-Pr) ₂ Si (OMe) ₂ was contained in an amount of 8.8% by weight.
Furthermore, prepolymerization was performed by the following procedure using the solid component obtained above. Purified n-heptane was introduced into the slurry, and the solid component concentration was adjusted to 20 g / L. Next, after cooling to 10 ° C. The slurry, 10 g was added n- heptane dilution of _Et 3 Al as _Et 3 Al, were fed over 4hr of propylene 280 g. After the supply of propylene was completed, the reaction was further continued for 30 minutes. Next, the gas phase was sufficiently replaced with nitrogen, and the reaction product was thoroughly washed with purified n-heptane. The obtained slurry was extracted from the autoclave and vacuum dried to obtain a solid catalyst component (A). This solid catalyst component contained 2.5 g of polypropylene per gram of solid component. Further, the portion of the solid catalyst component (A) excluding polypropylene contained 1.0% by weight of Ti and 8.2% by weight of (i-Pr) ₂ Si (OMe) ₂ .

(Ii) Production of propylene-based polymer This will be described with reference to the attached flow sheet shown in FIG. A gas phase polymerization reactor using two polymerization tanks was used. The two polymerization vessels 17 and 26 are continuous horizontal gas phase polymerization vessels (length / diameter = 5.2) equipped with a stirrer having an inner diameter D of 2100 mm, a length L of 11000 mm, and an internal volume of 40 m ^3. .
After replacing the inside of the polymerization vessel 17, a polypropylene powder from which polymer particles having a particle size of 500 μm or less were removed was charged, 120 g / Hr as the solid catalyst component (A), and a 15 wt% hexane solution of triethylaluminum in Ti in the catalyst component A It supplied continuously so that molar ratio might be set to 350 with respect to 1 mol of atoms. Further, hydrogen was adjusted so that the ratio of the hydrogen concentration in the polymerization vessel 17 to the propylene concentration was 0.095, ethylene was adjusted so that the ratio of the ethylene concentration to the propylene concentration was 0.020, and the pressure in the polymerization vessel 17 was 2. Propylene monomers were respectively supplied into the polymerization vessel 17 so as to maintain 2.10 MPa and a temperature of 61 ° C. The reaction heat was removed by the vaporization heat of the raw material propylene supplied from the raw material mixed gas supply pipe 19. The unreacted gas discharged from the polymerization vessel 17 was extracted from the reactor system through the unreacted gas extraction piping 20, cooled and condensed, and refluxed to the polymerization reactor 17 through the recycle gas piping 18.
The propylene-ethylene copolymer (b-1) produced in the polymerization vessel 17 is continuously fed from the polymerization vessel 17 through the polymer extraction pipe 21 so that the retained level of the polymer is 45% by volume of the reaction volume. It extracted and supplied to the superposition | polymerization device 26 of the 2nd superposition | polymerization process.
In the polymerization vessel 26, the polymer from the first polymerization step, and hydrogen so that the ratio of the hydrogen concentration in the polymerization vessel 26 to the propylene concentration is 0.021, and the ratio of the ethylene concentration to the propylene concentration is 0.00. Ethylene was supplied to the polymerization vessel 17 so that the pressure in the polymerization vessel 17 was 2.05 MPa and the temperature was maintained at 70 ° C. Further, a polymerization activity inhibitor for adjusting the polymerization amount of the propylene-ethylene copolymer (b-2) was supplied from the pipe 27. The reaction heat was removed by the vaporization heat of the raw material liquefied propylene supplied from the raw material mixed gas pipe 22. The unreacted gas discharged from the polymerization vessel 26 was extracted out of the reactor system through the unreacted gas extraction piping 24, cooled and condensed, and refluxed to the polymerization reactor 26 through the recycle gas piping 23. The propylene polymer produced in the second polymerization step was continuously extracted from the polymerizer 26 through the polymer extraction pipe 25 so that the retained level of the polymer was 50% by volume of the reaction volume. The extracted powder was subjected to gas separation by a gas recovery machine 28, and the powder part was extracted to a recovery system and granulated by a granulation system.
The production rate of the propylene polymer was 9.6 T / Hr, the average residence time in the polymerization vessel 17 was 1.9 Hr, and the average residence time in the polymerization vessel 26 was 1.3 Hr. When the catalyst efficiency was determined by dividing the production rate by the supply rate of the solid catalyst component A, it was 88900 g-PP / g-catalyst.
Moreover, when the obtained propylene polymer was analyzed, MFR was 38.9 g / 10min and ethylene content was 5.0 wt%. The PP component (b-1) had an MFR of 71.9 g / 10 min and an ethylene content of 2.5 wt%. When the index about PP component (b-2) was computed, MFR = 8.0g / 10min and ethylene content were 11.3 wt%.
Here, the MFR of the PP component (b-1) is logarithmically calculated from the MFR of the PP component (b-1) and the MFR of the propylene polymer, and the weight ratio of the PP components (b-1) and (b-2). Calculated according to the formula. The ethylene content was calculated from the ethylene content of the PP component (b-1), the ethylene content of the propylene polymer, and the weight ratio of the PP components (b-1) and (b-2). Here, the weight ratio of the PP components (b-1) and (b-2) is calculated from the amount of liquefied propylene supplied to the polymerization tank, and the production amount of the PP component (b-2) is It was 28% based on the total weight. The composition of the propylene-ethylene block copolymer (B) (PP-1) is shown in Table 1.

(3) Propylene-ethylene block copolymer different from propylene-ethylene block copolymer (B) <Production Example 2 (PP-2)>
(I) Production of solid catalyst component (B) 6 liters of n-hexane, 5.0 mol of diethylaluminum monochloride (DEAC), and 12.0 mol of diisoamyl ether were mixed at 25 ° C. for 5 minutes and then 5 minutes. Reaction was carried out at the same temperature to obtain reaction liquid (I) (diisoamyl ether / DEAC molar ratio 2.4). 40 moles of titanium tetrachloride was placed in a nitrogen-substituted reactor and heated to 35 ° C., and the entire amount of the reaction solution (I) was added dropwise to the reactor over 180 minutes, then kept at the same temperature for 30 minutes and heated to 75 ° C. The reaction is further allowed to proceed for 1 hour, cooled to room temperature, the supernatant is removed, 30 liters of n-hexane is added, and the supernatant is removed by decantation four times to obtain 1.9 kg of the solid product (II). Obtained. In a state where the whole amount of (II) is suspended in 30 liters of n-hexane, 1.6 kg of diisoamyl ether and 3.5 kg of titanium tetrachloride are added at 20 ° C. over about 5 minutes, and the mixture is heated to 60 ° C. For 1 hour. After completion of the reaction, the mixture was cooled to room temperature (20 ° C.), the supernatant was removed by decantation, 30 liters of n-hexane was added, stirred for 15 minutes, and allowed to stand to remove the supernatant 5 times. After repeating, it was dried under reduced pressure to obtain a Ti-based solid catalyst (B).
(Ii) Production of propylene-based polymer (pre-stage polymerization step: production of crystalline propylene polymer component)
A stainless steel autoclave with a stirrer having an internal volume of 400 liters was sufficiently substituted with propylene gas at room temperature, and 120 liters of dehydrated and deoxygenated n-heptane was added as a polymerization solvent. Next, under the condition of a temperature of 65 ° C., 86 g of diethylaluminum chloride, 50 liters of hydrogen (converted to the standard state), 10.5 ml of propionic acid, and 23 g of the catalyst (B) were added.
After raising the internal temperature of the autoclave to 70 ° C., propylene was supplied at a rate of 21.7 kg / hour and hydrogen was supplied at a rate of 126 L / hour to initiate polymerization. After 160 minutes, the introduction of propylene was stopped, and the pressure was 0.34 kg / cm ² G at the start of polymerization, increased with time during the supply of propylene, and increased to 7.7 kg / cm ² G when the supply was stopped. Then after the pressure is residual polymerization until 2.0kg / cm ² G, and releasing the unreacted gas in the vessel up to 0.3kg / cm ² G, to produce a crystalline propylene polymer component.
(Second-stage polymerization process: Propylene / ethylene random copolymer component production)
Subsequently, the internal temperature of the autoclave was lowered to 60 ° C., and propylene was supplied at a rate of 5.65 kg / hour and ethylene was supplied at a rate of 2.42 kg / hour. After 120 minutes, the introduction of propylene and ethylene was stopped, the pressure increased with time during the monomer supply, and increased to 2.8 kg / cm ² G when the supply was stopped. Then after the pressure is residual polymerization until 1.0kg / cm ² G, and releasing the unreacted gas in the vessel up to 0.3kg / cm ² G, to produce a propylene-ethylene random copolymer component.
The obtained solvent (slurry) containing the propylene-based block copolymer is transferred to the next tank with a stirrer, 5 liters of butanol is added, treated at 70 ° C. for 3 hours, further transferred to the next tank with a stirrer, water After adding 100 liters of pure water in which 100 g of sodium oxide was dissolved and treating for 1 hour, the aqueous layer was allowed to stand and then separated to remove the catalyst residue. The slurry is treated with a centrifuge to remove heptane, treated with a dryer at 80 ° C. for 3 hours to completely remove heptane, and from 53.2 kg of a crystalline propylene polymer component and a propylene / ethylene random copolymer component. A propylene-ethylene block copolymer (PP-2) was obtained.
Moreover, when the obtained propylene-ethylene block copolymer (PP-2) was analyzed, MFR was 9 g / 10min and ethylene content was 5.9 wt%. The PP component (b-1) had an MFR of 26.2 g / 10 min and an ethylene content of 0 wt%. When the index about PP component (b-2) was computed, MFR = 0.04g / 10min and ethylene content were 34.8 wt%.
Here, the MFR of the PP component (b-1) is logarithmically calculated from the MFR of the PP component (b-1) and the MFR of the propylene polymer, and the weight ratio of the PP components (b-1) and (b-2). Calculated according to the formula. The ethylene content was calculated from the ethylene content of the PP component (b-1), the ethylene content of the propylene polymer, and the weight ratio of the PP components (b-1) and (b-2). Here, the weight ratio of the PP components (b-1) and (b-2) is calculated from the amount of liquefied propylene supplied to the polymerization tank, and the production amount of the PP component (b-2) is It was 16.9% based on the total weight. The composition of the propylene-ethylene block copolymer (PP-2) is shown in Table 1.

(4) Nucleating agent (i) Organophosphate metal salt compound nucleating agent ADK STAB NA-11 (NA-11; manufactured by ADEKA Corporation): Corresponding to nucleating agent (A) (ii) Organophosphate metal Salt compound nucleating agent ADK STAB NA21 (NA-21; manufactured by ADEKA): equivalent to nucleating agent (B) (iii) XT386 (XT386; manufactured by BASF): equivalent to nucleating agent (C) (iv) ) NX8000 (manufactured by Milliken): equivalent to nucleating agent (D) (5) neutralizing agent (i) DHT-4A: hydrotalcite (manufactured by Kyowa Chemical Industry Co., Ltd.)
(6) Antioxidant (i) Phosphorous antioxidant: Irgaphos 168 (IF168; manufactured by BASF), Tris (2,4-di-tert-butylphenol) phosphite (ii) Hindered amine UV stabilizer: TINUVIN622LD ( TNV622; manufactured by BASF), dimethyl oxalate 2- (4-hydroxy-2,2,6,6-tetramethylpiperidine) ethanol condensate

(Examples 1-8, Comparative Example 1)
Propylene polymer, nucleating agent and other additives (antioxidant, neutralizing agent, etc.) prepared in the blending ratios (parts by weight) shown in Table 2, and after dry blending with a super mixer, 35 mm diameter Were melt-kneaded using a twin-screw extruder. Extruded pellets from the die at a die outlet temperature of 230 ° C. The obtained pellets were injection molded by an injection molding machine at a resin temperature of 230 ° C., an injection pressure of 600 kg / cm ^2, and a mold temperature of 40 ° C. to prepare test pieces. The physical properties were measured using the obtained test pieces. The results are shown in Table 2.

  From Table 2, Examples 1 to 8 are the products of the present invention in which the propylene homopolymer is blended with the propylene-ethylene block copolymer (B), which is excellent in the balance between rigidity and impact resistance after radiation sterilization. It turns out that transparency is excellent. In particular, Examples 4 to 8 are excellent in balance. On the other hand, the comparative example 1 mix | blends the propylene-ethylene block copolymer different from a propylene-ethylene block copolymer (B), and although rigidity and impact resistance are excellent, transparency is inferior.

Example 9
(4) JIS T3210: 2011 sterilized syringe 6 chemical requirements, and (5) Yakusei No. 494, as described above, using the pellets obtained by Examples 4, 6, 7, 8 Dialysis-type artificial kidney device approval criteria As a result of the quality and test of IV blood circuit, it was confirmed that all items were within the applicable range.

  The present invention has good molding processability at the time of injection molding, excellent balance between rigidity and impact resistance, excellent transparency, particularly excellent impact resistance after radiation sterilization and low elution, and JIS T3210: 2011. 6 chemical requirements described in sterile syringes or approval standards for Yakusei No. 494 dialysis artificial kidney device IV Heavy circuit test, lead test, cadmium test, eluate test described in IV blood circuit quality and test method Propylene-ethylene resin composition for medical use satisfying after radiation sterilization, and injection molded products obtained by using the same, especially injection molded products for medical use, particularly syringe members and artificial dialysis members. It is very useful.

1 Arm of person undergoing dialysis 2 Tube 3 Blood pump 4 Air trap 5 Dializer 6 Console 7 Blood inlet (with cap)
8 Blood outlet (with cap)
9 Dialysate inlet (with cap)
10 Dialysate outlet (with cap)
11 Hollow Fiber 12 Dializer Housing 13 Dializer Header 14 Outer Cylinder 15 Pusher 16 Gasket 17 Polymerizer (First Polymerization Step)
18 Recycled gas pipe 19 Raw material mixed gas pipe 20 Unreacted gas outlet pipe 21 Polymer outlet pipe 22 Raw material mixed gas pipe 23 Recycled gas pipe 24 Unreacted gas outlet pipe 25 Polymer outlet pipe 26 Polymerizer (second polymerization step)
27 Pipeline for adding polymerization activity inhibitor 28 Gas recovery machine 29 Bag filter

Claims (6)

A propylene homopolymer polymerized by a Ziegler-Natta catalyst or a propylene copolymer composed of propylene and an α-olefin having a content of less than 1% by weight, conforming to JIS K7210 (230 ° C, 2.16 kg load) 60 to 99 parts by weight of a propylene-based (co) polymer (A) having a melt flow rate (hereinafter sometimes abbreviated as MFR) of 0.5 to 100 g / 10 min, and (Bi) A nucleating agent is added to 100 parts by weight of a propylene-based resin composed of 1 to 40 parts by weight of a propylene-ethylene block copolymer (B) polymerized by a Ziegler-Natta catalyst satisfying the characteristics of (B-iv). A propylene-based resin composition for medical use (Bi) containing 0.005 to 0.6 parts by weight and used after being subjected to radiation sterilization treatment. 1 to 3% by weight, propylene-ethylene copolymer (b-1) having an MFR of 10 to 300 g / 10 min and propylene-ethylene copolymer having an ethylene content of 5 to 20% by weight and MFR of 1 to 50 g / 10 min Propylene-ethylene block copolymer (B) comprising the polymer (b-2)
(B-ii) The weight ratio of the propylene-ethylene copolymer (b-1) to the propylene-ethylene copolymer (b-2) is 90:10 to 60:40.
(B-iii) Propylene-ethylene block copolymer (B) has an ethylene content of 2 to 8% by weight.
(B-iv) MFR ratio (b-1 / b-2) of propylene-ethylene copolymer (b-1) and propylene-ethylene copolymer (b-2) is 1 to 30, and propylene-ethylene The MFR of the block copolymer (B) is 10 to 100 g / 10 min. The nucleating agent is 0.01 to 0.3 part by weight of the nucleating agent (A) represented by the following formula (1), and 0.01 to 0.2 nucleating agent (B) represented by the following formula (2). Parts by weight, nucleating agent (C) represented by the following formula (3) 0.005 to 0.03 parts by weight and nucleating agent (D) represented by the following formula (4) 0.1 to 0.5 parts by weight The medical propylene-based resin composition according to claim 1, wherein the composition is at least one nucleating agent selected from the group consisting of:

[Wherein, R ¹ is a direct bond, sulfur, an alkylene group having 1 to 9 carbon atoms or an alkylidene group, and R ² and R ³ are the same or different and each represents a hydrogen atom or an alkyl having 1 to 8 carbon atoms. A group, M is Na, and n is the valence of M. ]

[Wherein, R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R ² and R ³ are the same or different and each represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms; Represents a group III or group IV metal atom of the periodic table, X represents HO— when M represents a group III metal atom of the periodic table, and M represents group IV of the periodic table. When a group metal atom is shown, O = or (HO) _2- . ]

_[R 1 ~R 3: t- butyl]

  The medical propylene-based resin composition according to claim 1 or 2, wherein the sterilization method is sterilized by gamma rays or electron beams of 1 kGy to 60 kGy.   The medical molded article using the propylene-type resin composition of any one of Claims 1-3.   An injection molded product for medical use, wherein the medical molded product according to claim 4 is a syringe member.   An injection molded product for medical use, wherein the medical molded product according to claim 4 is an artificial dialysis member.

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