JP7509549B2 - Cyclic olefin copolymer composition for medical device and molded article - Google Patents

Description

The present invention relates to a cyclic olefin copolymer composition for medical devices and a molded article.

In recent years, progress has been made in developing resins with excellent optical properties that can replace glass in optical materials such as those used in mobile phones and automotive camera lenses. Among glass-substitute resins, attention has been focused on hydrogenated ring-opening polymers of cyclic olefins and addition copolymers of cyclic olefins, which have lower water absorption and less dimensional change than resins such as PC (polycarbonate) and PMMA (polymethyl methacrylate).

For example, regarding hydrogenated ring-opening polymers of cyclic olefins, Patent Documents 1 and 2 describe a resin with high refraction, yellowing resistance, and moldability, which is obtained by ring-opening metathesis polymerization of monomers derived from tetracyclododecene and norbornene compounds. Patent Document 3 describes a resin with good breaking strength that can be obtained by ring-opening metathesis polymerization of a three-membered cyclopentene monomer. Patent Document 4 describes a biochemical instrument that comes into contact with a biochemical sample, in which the part that comes into contact with the biochemical sample is made of a resin composition containing at least one cyclic olefin-based polymer selected from the group consisting of a copolymer of a cyclic olefin and a chain olefin, a ring-opening polymer of a cyclic olefin, and a hydrogenated product of a ring-opening polymer of a cyclic olefin, and an antioxidant, thereby effectively suppressing the adsorption of biochemical substances.

JP 2007-137935 A International Publication No. 2016/052302 International Publication No. 2017/051819 International Publication No. 2019/065149

On the other hand, glass substitute resins are expected to be used in various medical applications, including prefilled syringes, in addition to lenses. Medical instruments such as syringes and drug solution storage containers are usually filled with contents after sterilization. During this sterilization, the instruments may be irradiated with electron beams or gamma rays. According to the study by the present inventors, it has become clear that in medical containers using conventional cyclic olefin resins, radicals may be generated during sterilization by gamma ray irradiation, which may cause a problem of adversely affecting the enclosed drug. In addition, although the influence of radicals generated by gamma ray irradiation decreases over time, it takes a long period of several weeks for the influence of radicals to disappear, which is not preferable from the viewpoint of improving productivity and shortening the process.
It has become clear that discoloration may occur due to electron beam or gamma ray irradiation.
As a result of intensive research, the present inventors have found that the above-mentioned problems can be solved by using a cyclic olefin copolymer containing a specific structural unit (A) having an aromatic ring. However, a molded article using such a cyclic olefin copolymer has room for improvement in terms of impact resistance.

The present invention has been made in view of these circumstances. That is, the present invention provides a cyclic olefin copolymer composition for medical devices that has a glass transition temperature that allows it to be molded into the shape of a container or the like, generates a small amount of radicals when irradiated with gamma rays, and has excellent impact resistance.

As a result of intensive research, the inventors have found that the above problems can be solved by combining a cyclic olefin copolymer containing a specific structural unit (A) having an aromatic ring with a styrene-based elastomer.

That is, according to the present invention, the following cyclic olefin copolymer composition for medical devices and molded articles are provided.

（上記式（Ｉａ）中、ｎは０、１または２であり、Ｒ^１～Ｒ^１４はそれぞれ独立に、水素原子、フッ素原子を除くハロゲン原子、またはフッ素原子を除くハロゲン原子で置換されていてもよい炭素原子数１～２０の炭化水素基であり、Ｒ^１１～Ｒ^１４の少なくとも一つは結合手であり、１つ又は複数の結合種のそれぞれに独立に（Ｉｂ）又は（Ｉｃ）のいずれが結合する。）

（上記式（Ｉｂ）中、ｎは０～２０であり、ｑは０、１または２であり、Ｒ^１５～Ｒ^２４はそれぞれ独立に、水素原子、フッ素原子を除くハロゲン原子、またはフッ素原子を除くハロゲン原子で置換されていてもよい炭素原子数１～２０の炭化水素基であり、Ｒ^１７～Ｒ^２４のうち一つは結合手であり、またｑ＝０のときＲ^１７とＲ^１８、Ｒ^１８とＲ^１９、Ｒ^１９とＲ^２０、Ｒ^２０とＲ^２１、Ｒ^２１とＲ^２２、Ｒ^２２とＲ^１７は互いに結合して単環または多環を形成していてもよく、またｑ＝１または２のときＲ^１７とＲ^１８、Ｒ^１８とＲ^２４、Ｒ^２４とＲ^２４、Ｒ^２４とＲ^１９、Ｒ^１９とＲ^２０、Ｒ^２０とＲ^２１、Ｒ^２１とＲ^２２、Ｒ^２２とＲ^２３、Ｒ^２３とＲ^２３、Ｒ^２３とＲ^１７は互いに結合して単環または多環を形成していてもよく、また上記単環または上記多環が二重結合を有していてもよく、上記単環または上記多環が芳香族環であってもよい。）

（上記式（Ｉｃ）中、ｎは０～２０であり、ｍおよびｇはそれぞれ独立に０～１０であり、ｒは１、２または３であり、Ｒ^２５～Ｒ^３５はそれぞれ独立に、水素原子、フッ素原子を除くハロゲン原子、またはフッ素原子を除くハロゲン原子で置換されていてもよい炭素原子数１～２０の炭化水素基であり、ｒ＝１のときＲ^３２とＲ^３３、Ｒ^３３とＲ^３４、Ｒ^３４とＲ^３５は互いに結合して単環または多環を形成していてもよく、またｒ＝２または３のときＲ^３２とＲ^３２、Ｒ^３２とＲ^３３、Ｒ^３３とＲ^３４、Ｒ^３４とＲ^３５、Ｒ^３５とＲ^３５は互いに結合して単環または多環を形成していてもよく、また上記単環または上記多環が二重結合を有していてもよく、上記単環または上記多環が芳香族環であってもよい。）

（上記式（ＩＩ）中、ｎ、ｍおよびｇはそれぞれ独立に０、１または２であり、ｒは１、２または３であり、Ｒ^３６～Ｒ^５５はそれぞれ独立に、水素原子、フッ素原子を除くハロゲン原子、またはフッ素原子を除くハロゲン原子で置換されていてもよい炭素原子数１～２０の炭化水素基であり、またｒ＝１のときＲ^５２とＲ^５３、Ｒ^５３とＲ^５４、Ｒ^５４とＲ^５５は互いに結合して単環または多環を形成していてもよく、またｒ＝２または３のときＲ^５２とＲ^５２、Ｒ^５２とＲ^５３、Ｒ^５３とＲ^５４、Ｒ^５４とＲ^５５、Ｒ^５５とＲ^５５は互いに結合して単環または多環を形成していてもよく、上記単環または上記多環が二重結合を有していてもよく、また上記単環または上記多環が芳香族環であってもよく、また、Ｒ^４８とＲ^５０は互いに結合して単環または多環を形成していてもよく、上記単環または上記多環が二重結合を有していてもよく、また上記単環または上記多環が芳香族環であってもよい。）

（上記式（ＩＩＩ）中、ｎは０、１または２であり、ｍは１、２または３であり、Ｒ^５５～Ｒ^６８はそれぞれ独立に、水素原子、フッ素原子を除くハロゲン原子、またはフッ素原子を除くハロゲン原子で置換されていてもよい炭素原子数１～２０の炭化水素基であり、またｍ＝１のときＲ^６５とＲ^６７、Ｒ^６７とＲ^６８、Ｒ^６８とＲ^６６は互いに結合して単環または多環を形成していてもよく、またｍ＝２または３のときＲ^６５とＲ^６５、Ｒ^６５とＲ^６７、Ｒ^６７とＲ^６８、Ｒ^６８とＲ^６６、Ｒ^６６とＲ^６６は互いに結合して単環または多環を形成していてもよく、上記単環または上記多環が二重結合を有していてもよく、また上記単環または上記多環が芳香族環であってもよい。）
［２］
上記［１］に記載の医療用器具用環状オレフィン共重合体組成物において、
上記医療用器具用環状オレフィン共重合体組成物に含まれる上記環状オレフィン共重合体と上記スチレン系エラストマーの合計量を１００質量部としたとき、
上記スチレン系エラストマーの含有量が１１質量部以上５０質量部以下である医療用器具用環状オレフィン共重合体組成物。
［３］
上記［１］または［２］に記載の医療用器具用環状オレフィン共重合体組成物において、
上記環状オレフィン共重合体中の上記構造単位（Ａ）の含有量が０．２モル％以上１００モル％以下である医療用器具用環状オレフィン共重合体組成物。
［４］
上記［１］乃至［３］のいずれか一つに記載の医療用器具用環状オレフィン共重合体組成物において、
上記環状オレフィン共重合体が、炭素原子数が２～２０のオレフィン由来の構造単位（Ｂ）をさらに含む医療用器具用環状オレフィン共重合体組成物。
［５］
上記［４］に記載の医療用器具用環状オレフィン共重合体組成物において、
上記構造単位（Ｂ）が、脂環構造を有する医療用器具用環状オレフィン共重合体組成物。
［６］
上記［４］または［５］に記載の医療用器具用環状オレフィン共重合体組成物において、
上記環状オレフィン共重合体中の上記構造単位（Ａ）と上記構造単位（Ｂ）の合計含有量を１００モル％としたとき、上記環状オレフィン共重合体中の上記構造単位（Ａ）の含有量が０．５モル％以上１００モル％以下である医療用器具用環状オレフィン共重合体組成物。
［７］
上記［１］乃至［６］のいずれか一つに記載の医療用器具用環状オレフィン共重合体組成物において、
示差走査熱量計（ＤＳＣ）で測定される、上記環状オレフィン共重合体のガラス転移温度（Ｔｇ）が８０℃以上２００℃以下である医療用器具用環状オレフィン共重合体組成物。
［８］
上記［１］乃至［７］のいずれか一つに記載の医療用器具用環状オレフィン共重合体組成物において、
上記構造単位（Ａ）が、ベンゾノルボルナジエン、インデンノルボルネンおよびメチルフェニルノルボルネンから選択される少なくとも一つを由来とする医療用器具用環状オレフィン共重合体組成物。
［９］
上記［１］乃至［８］のいずれか一つに記載の医療用器具用環状オレフィン共重合体組成物を含む成形体。
［１０］
医療用器具である、上記［９］に記載の成形体。
［１１］
上記医療用器具が、カテーテル部材、滅菌シート、医療用容器、バイオチップまたは医療用フィルムである、上記［１０］に記載の成形体。 [1]
A cyclic olefin copolymer having an aromatic ring, the cyclic olefin copolymer including at least one structural unit (A) selected from the following (Ia), (II), and (III):
A styrene-based elastomer,
A cyclic olefin copolymer composition for a medical device comprising:

(In the above formula (Ia), n is 0, 1 or 2; R ¹ to R ¹⁴ each independently represent a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom; at least one of R ¹¹ to R ¹⁴ is a bond; and either (Ib) or (Ic) is bonded to each of the one or more bonding types independently.)

(In the above formula (Ib), n is 0 to 20, q is 0, 1 or 2, R ¹⁵ to R ²⁴ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted by a halogen atom other than a fluorine atom, one of R ¹⁷ to R ²⁴ is a bond, and when q=0, R ¹⁷ and R ¹⁸ , R ¹⁸ and R ¹⁹ , R ¹⁹ and R ²⁰ , R ²⁰ and R ²¹ , R ²¹ and R ²² , and R ²² and R ¹⁷ may be bonded to each other to form a monocyclic or polycyclic ring, and when q=1 or 2, R ¹⁷ and R ¹⁸ , R ¹⁸ and R ²⁴ , R ²⁴ and R ²⁴ , R ²⁴ and R ¹⁹ , R ¹⁹ and R ²⁰ , R ²⁰ and R ²¹ , and R ^R21 and ^R22 , ^R22 and ^R23 , ^R23 and ^R23 , and ^R23 and ^R17 may be bonded to each other to form a monocycle or polycycle, and the monocycle or polycycle may have a double bond, or the monocycle or polycycle may be an aromatic ring.

(In the above formula (Ic), n is 0 to 20, m and g are each independently 0 to 10, r is 1, 2 or 3, R ²⁵ to R ³⁵ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom, and when r=1, R ³² and R ³³ , R ³³ and R ³⁴ , and R ³⁴ and R ³⁵ may be bonded to each other to form a monocycle or polycycle, and when r=2 or 3, R ³² and R ³² , R ³² and R ³³ , R ³³ and R ³⁴ , R ³⁴ and R ³⁵ , and R ³⁵ and R ³⁵ may be bonded to each other to form a monocycle or polycycle, and the monocycle or polycycle may have a double bond, and the monocycle or polycycle may be an aromatic ring.)

(In the above formula (II), n, m and g are each independently 0, 1 or 2; r is 1, 2 or 3; R ³⁶ to R ⁵⁵ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom; when r=1, R ⁵² and R ⁵³ , R ⁵³ and R ⁵⁴ , and R ⁵⁴ and R ⁵⁵ may be bonded to each other to form a monocycle or polycycle; when r=2 or 3, R ⁵² and R ⁵² , R ⁵² and R ⁵³ , R ⁵³ and R ⁵⁴ , R ⁵⁴ and R ⁵⁵ , and R ⁵⁵ and R ⁵⁵ may be bonded to each other to form a monocycle or polycycle, the monocycle or polycycle may have a double bond, and the monocycle or polycycle may be an aromatic ring; R ⁴⁸ and R ⁵⁰ may be bonded to each other to form a monocyclic or polycyclic ring, the monocyclic or polycyclic ring may have a double bond, or the monocyclic or polycyclic ring may be an aromatic ring.

(In the above formula (III), n is 0, 1 or 2, m is 1, 2 or 3, R ⁵⁵ to R ⁶⁸ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom, and when m=1, R ⁶⁵ and R ⁶⁷ , R ⁶⁷ and R ⁶⁸ , and R ⁶⁸ and R ⁶⁶ may be bonded to each other to form a monocycle or polycycle, and when m=2 or 3, R ⁶⁵ and R ⁶⁵ , R ⁶⁵ and R ⁶⁷ , R ⁶⁷ and R ⁶⁸ , R ⁶⁸ and R ⁶⁶ , and R ⁶⁶ and R ⁶⁶ may be bonded to each other to form a monocycle or polycycle, the monocycle or polycycle may have a double bond, and the monocycle or polycycle may be an aromatic ring.)
[2]
In the cyclic olefin copolymer composition for medical devices according to the above-mentioned [1],
When the total amount of the cyclic olefin copolymer and the styrene-based elastomer contained in the cyclic olefin copolymer composition for medical devices is 100 parts by mass,
A cyclic olefin copolymer composition for medical devices, comprising the styrene-based elastomer in an amount of 11 parts by mass or more and 50 parts by mass or less.
[3]
In the cyclic olefin copolymer composition for a medical device according to the above [1] or [2],
A cyclic olefin copolymer composition for use in a medical device, wherein the content of the structural unit (A) in the cyclic olefin copolymer is from 0.2 mol % to 100 mol %.
[4]
In the cyclic olefin copolymer composition for a medical device according to any one of the above [1] to [3],
The cyclic olefin copolymer composition for medical devices, wherein the cyclic olefin copolymer further contains a structural unit (B) derived from an olefin having 2 to 20 carbon atoms.
[5]
In the cyclic olefin copolymer composition for medical devices according to the above [4],
A cyclic olefin copolymer composition for medical devices, wherein the structural unit (B) has an alicyclic structure.
[6]
In the cyclic olefin copolymer composition for medical devices according to the above [4] or [5],
A cyclic olefin copolymer composition for a medical device, in which the content of the structural unit (A) in the cyclic olefin copolymer is 0.5 mol % or more and 100 mol % or less, when the total content of the structural unit (A) and the structural unit (B) in the cyclic olefin copolymer is 100 mol %.
[7]
In the cyclic olefin copolymer composition for a medical device according to any one of the above [1] to [6],
The cyclic olefin copolymer composition for medical devices has a glass transition temperature (Tg) of 80° C. or higher and 200° C. or lower, as measured by a differential scanning calorimeter (DSC).
[8]
In the cyclic olefin copolymer composition for a medical device according to any one of the above [1] to [7],
A cyclic olefin copolymer composition for medical devices, wherein the structural unit (A) is derived from at least one selected from the group consisting of benzonorbornadiene, indenenorbornene, and methylphenylnorbornene.
[9]
A molded article comprising the cyclic olefin copolymer composition for medical devices according to any one of the above [1] to [8].
[10]
The molded article according to the above-mentioned [9], which is a medical device.
[11]
The molded article according to the above-mentioned [10], wherein the medical device is a catheter member, a sterilized sheet, a medical container, a biochip or a medical film.

The present invention provides a cyclic olefin copolymer composition for medical devices that has a glass transition temperature that allows it to be molded into the shape of a container or the like, generates a small amount of radicals when irradiated with gamma rays, and has excellent impact resistance.

The present invention will be described below based on an embodiment. In this embodiment, "A to B" indicating a numerical range means A or more and B or less unless otherwise specified.

[Cyclic Olefin Copolymer Composition]
The cyclic olefin copolymer composition for a medical device according to this embodiment contains a cyclic olefin copolymer (P) having an aromatic ring, the cyclic olefin copolymer containing a specific structural unit (A) having an aromatic ring, and a styrene-based elastomer, and may contain other components other than the cyclic olefin copolymer (P) and the styrene-based elastomer as necessary.
The cyclic olefin copolymer composition for medical devices according to this embodiment contains the cyclic olefin copolymer (P) and a styrene-based elastomer, and thus has the properties generally required for medical devices, a glass transition temperature that allows it to be molded into the shape of a container or the like, generates a small amount of radicals when irradiated with gamma rays, and is capable of giving a molded article with excellent impact resistance.
The cyclic olefin copolymer composition for medical devices according to this embodiment is a cyclic olefin copolymer composition for medical devices, and the above-mentioned characteristics generally required for medical devices specifically mean good moldability during molding, high transparency of the molded body, etc.

In the cyclic olefin copolymer composition for medical devices according to this embodiment, when the total amount of the cyclic olefin copolymer (P) and the styrene-based elastomer contained in the cyclic olefin copolymer composition for medical devices according to this embodiment is taken as 100 parts by mass, the content of the styrene-based elastomer is preferably 11 parts by mass or more and 50 parts by mass or less, more preferably 13 parts by mass or more and 40 parts by mass or less, and even more preferably 15 parts by mass or more and 35 parts by mass or less, from the viewpoint of further improving the performance balance of radiation resistance, impact resistance, and transparency of the obtained molded article.

In addition, the total content of the cyclic olefin copolymer (P) and the styrene-based elastomer in the cyclic olefin copolymer composition for medical devices according to this embodiment is preferably 50% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, even more preferably 80% by mass or more and 100% by mass or less, and particularly preferably 90% by mass or more and 100% by mass or less, when the entire cyclic olefin copolymer composition for medical devices is taken as 100% by mass, from the viewpoint of further improving the performance balance of radiation resistance, impact resistance, and transparency of the resulting molded article.

(Cyclic olefin copolymer)
The cyclic olefin copolymer (P) according to this embodiment will be described below.
The cyclic olefin copolymer (P) according to this embodiment is a cyclic olefin copolymer having an aromatic ring, and is a cyclic olefin copolymer containing a structural unit (A).

The structural unit (A) according to this embodiment will be described below.
The structural unit (A) according to this embodiment contains at least one of the following structural units (Ia), (II), and (III).

In the above formula (Ia), n is 0, 1 or 2. R ¹ to R ¹⁴ each independently represent a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom. At least one of R ¹¹ to R ¹⁴ is a bond, and either (Ib) or (Ic) is bonded to each of one or more bonding types independently.

In the above formula (Ib), n is 0 to 20, and q is 0, 1 or 2. R ¹⁵ to R ²⁴ each independently represent a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom. One of R ¹⁷ to R ²⁴ is a bond, and when q=0, R ¹⁷ and R ¹⁸ , R ¹⁸ and R ¹⁹ , R ¹⁹ and R ²⁰ , R ²⁰ and R ²¹ , R ²¹ and R ²² , and R ²² and R ¹⁷ may be bonded to each other to form a monocycle or polycycle, and when q=1 or 2, R ¹⁷ and R ¹⁸ , R ¹⁸ and R ²⁴ , R ²⁴ and R ²⁴ , R ²⁴ and R ¹⁹ , R ¹⁹ and R ²⁰ , R ²⁰ and R ²¹ , R ²¹ and R ²² , R ²² and R ²³ , R ²³ and R ²³ , and R ²³ and R ^{The 17s} may be bonded to each other to form a monocyclic or polycyclic ring, and the monocyclic or polycyclic ring may have a double bond, or the monocyclic or polycyclic ring may be an aromatic ring.

In the above formula (Ia), when the above formula (Ib) is bonded to at least one of R ¹¹ to R ¹⁴ , at least one of R ¹¹ to R ¹⁴ in the above formula (Ia) can be a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom excluding a fluorine atom. In particular, when the above formula (Ib) is bonded to at least one of R ¹¹ to R ¹⁴ in the above formula (Ia), and n in the above formula (Ib) is 0 to 2, it is preferable that at least one of R ¹¹ to R ¹⁴ is a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom excluding a fluorine atom.

The structural unit (A) according to this embodiment may also be in an embodiment that does not include structural units represented by the following formulas (A'-1), (A'-2), and (A'-3).

In the above formula (Ic), n is 0 to 20, m and g are each independently 0 to 10, and r is 1, 2, or 3. R ²⁵ to R ³⁵ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom. When r=1, R ³² and R ³³ , R ³³ and R ³⁴ , and R ³⁴ and R ³⁵ may be bonded to each other to form a monocycle or polycycle, and when r=2 or 3, R ³² and R ³² , R ³² and R ³³ , R ³³ and R ³⁴ , R ³⁴ and R ³⁵ , and R ³⁵ and R ³⁵ may be bonded to each other to form a monocycle or polycycle, and the monocycle or polycycle may have a double bond, or the monocycle or polycycle may be an aromatic ring.

上記式（ＩＩ）中、ｎ、ｍおよびｇはそれぞれ独立に０、１または２であり、ｒは１、２または３である。Ｒ^３６～Ｒ^５５はそれぞれ独立に、水素原子、フッ素原子を除くハロゲン原子、またはフッ素原子を除くハロゲン原子で置換されていてもよい炭素原子数１～２０の炭化水素基である。またｒ＝１のときＲ^５２とＲ^５３、Ｒ^５３とＲ^５４、Ｒ^５４とＲ^５５は互いに結合して単環または多環を形成していてもよく、またｒ＝２または３のときＲ^５２とＲ^５２、Ｒ^５２とＲ^５３、Ｒ^５３とＲ^５４、Ｒ^５４とＲ^５５、Ｒ^５５とＲ^５５は互いに結合して単環または多環を形成していてもよく、上記単環または上記多環が二重結合を有していてもよく、また上記単環または上記多環が芳香族環であってもよく、また、Ｒ^４８とＲ^５０は互いに結合して単環または多環を形成していてもよく、上記単環または上記多環が二重結合を有していてもよく、また上記単環または上記多環が芳香族環であってもよい。

In the above formula (II), n, m and g each independently represent 0, 1 or 2, and r is 1, ² or ^3. R to R each independently represent a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom. When r=1, ^R52 and ^R53 , R53 and ^R54 , and ^R54 and ^R55 may be bonded together ^to form a monocycle or polycycle, and when r=2 or 3, ^R52 and ^R52 , ^R52 and ^R53 , ^R53 and ^R54 , ^R54 and ^R55 , and ^R55 and ^R55 may be bonded together to form a monocycle or polycycle, and the monocycle or polycycle may have a double bond, or the monocycle or polycycle may be an aromatic ring, and ^R48 and ^R50 may be bonded together to form a monocycle or polycycle, and the monocycle or polycycle may have a double bond, or the monocycle or polycycle may be an aromatic ring.

In the above formula (III), n is 0, 1 or 2, and m is 1, 2 or 3. R ⁵⁵ to R ⁶⁸ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom. When m=1, R ⁶⁵ and R ⁶⁷ , R ⁶⁷ and R ⁶⁸ , and R ⁶⁸ and R ⁶⁶ may be bonded to each other to form a monocycle or polycycle, and when m=2 or 3, R ⁶⁵ and R ⁶⁵ , R ⁶⁵ and R ⁶⁷ , R ⁶⁷ and R ⁶⁸ , R ⁶⁸ and R ⁶⁶ , and R ⁶⁶ and R ⁶⁶ may be bonded to each other to form a monocycle or polycycle, the monocycle or polycycle may have a double bond, and the monocycle or polycycle may be an aromatic ring.

Examples of the hydrocarbon group having 1 to 20 carbon atoms include, independently, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 15 carbon atoms, and an aromatic hydrocarbon group. More specifically, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an amyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, and an octadecyl group. Examples of the cycloalkyl group include a cyclohexyl group. Examples of the aromatic hydrocarbon group include an aryl group or an aralkyl group such as a phenyl group, a tolyl group, a naphthyl group, a benzyl group, and a phenylethyl group. These hydrocarbon groups may be substituted with a halogen atom other than a fluorine atom.
The above general formulae (Ia), (II), and (III) each include a resonance structure.

Among these, the structural unit (A) according to the present embodiment is preferably a structural unit derived from at least one selected from, for example, benzonorbornadiene, indenenorbornene, phenylnorbornene, methylphenylnorbornene, and the following general formula (A-5), more preferably a structural unit derived from at least one selected from benzonorbornadiene, indenenorbornene, and methylphenylnorbornene, and particularly preferably a structural unit derived from benzonorbornadiene or indenenorbornene.

The structural unit derived from indene norbornene, the structural unit derived from benzonorbornadiene, and the structural unit derived from methylphenylnorbornene specifically mean structural units represented by the following formulae (A-2), (A-3), and (A-4), respectively.
That is, the structural unit (A) according to this embodiment is preferably any one of structural units represented by the following formula (A-2), formula (A-3), and formula (A-4).

(Structural unit (B) derived from olefin having 2 to 20 carbon atoms)
The cyclic olefin copolymer (P) according to this embodiment may also contain a structural unit (B) derived from an olefin having 2 to 20 carbon atoms. The structural unit (B) may be a structural unit derived from a cyclic olefin having no aromatic ring.

The structural unit (B) preferably has an alicyclic structure. When the structural unit (B) has an alicyclic structure, the cyclic olefin copolymer composition for medical devices has a glass transition temperature that allows it to be molded into a shape such as a container, and can produce a molded product that generates a small amount of radicals when irradiated with gamma rays.
Moreover, the structural unit (B) more preferably has a 5-membered alicyclic structure. By making the structural unit (B) a structural unit having a 5-membered alicyclic structure, the time required for the reaction to form the structural unit (A) and the time required for the reaction to form the structural unit (B) can be made approximately equal, so that a cyclic olefin copolymer having the structural unit (A) and the structural unit (B) can be efficiently produced, which is preferable from the viewpoint of production convenience.

（上記式［Ｂ－１］中、ｎは０または１であり、ｍは０または正の整数であり、ｑは０または１であり、Ｒ^１～Ｒ^１８ならびにＲ^ａおよびＲ^ｂは、それぞれ独立に、水素原子、ハロゲン原子またはハロゲン原子で置換されていてもよい炭化水素基であり、Ｒ^１５～Ｒ^１８は互いに結合して単環または多環を形成していてもよく、かつ、該単環または多環は二重結合を有していてもよく、またＲ^１５とＲ^１６とで、またはＲ^１７とＲ^１８とでアルキリデン基を形成していてもよい。ただし、芳香環を含まない。） As the structural unit (B) according to this embodiment, from the viewpoint of obtaining a cyclic olefin copolymer composition for a medical device that has a glass transition temperature that allows it to be molded into a shape such as a container and that generates a molded product with a small amount of radicals upon gamma ray irradiation, it is preferable that the structural unit (B) contains a structural unit derived from a compound represented by the following formula (B-1):

(In the above formula [B-1], n is 0 or 1, m is 0 or a positive integer, q is 0 or 1, R ¹ to R ¹⁸ , and R ^a and R ^b are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group which may be substituted with a halogen atom, and R ¹⁵ to R ¹⁸ may be bonded to each other to form a monocyclic or polycyclic ring, and the monocyclic or polycyclic ring may have a double bond, and R ¹⁵ and R ¹⁶ , or R ¹⁷ and R ¹⁸ may be combined to form an alkylidene group, but does not include an aromatic ring.)

Among these, the structural unit (B) according to the present embodiment includes a structural unit derived from bicyclo[2.2.1]-2-heptene (abbreviation: NB), a structural unit derived from tetracyclo[4.4.0.1 ^2,5 . It ^is preferable that the copolymer contains at least one structural unit selected from structural units derived from hexacyclo[6,6,1,1 ^3,6 ,1 ^10,13 ,0 ^2,7 ,0 ^9,14 ]heptadecene-4, ethylnorbornene (ENB), dicyclopentadiene (DCPD), DCPD hydride and tricycloundecene (TCU, 1,4,4a,5,6,7,8,8a-octahydro-1,4-methanonaphthalene), and the like. It is preferable that the copolymer contains at least one structural unit selected from structural units derived from bicyclo[2.2.1]-2-heptene and tetracyclo[4.4.0.1 ^2,5 . It is more preferable that the copolymer contains at least one structural unit selected from structural units derived from tetracyclo[4.4.0.1 ^2,5 .1 ^7,10 ]-3-dodecene, and it is particularly preferable that the copolymer contains a structural unit derived from tetracyclo[ ^4.4.0.1 2,5 .1 7,10 ]-3-dodecene.

The structural unit derived from tetracyclo[ ^{4.4.0.12,5.17,10} ]-3- ^dodecene specifically means a structural unit represented by the following formula (B-2). That is, the structural unit (B) according to the present embodiment preferably contains a structural unit represented by the following formula (B-2).

The structural unit derived from DCPD specifically means a structural unit represented by the following formula (B-3) or formula (B-4).

In the cyclic olefin copolymer (P) according to this embodiment, the content of the structural unit (A) is preferably 0.2 mol% or more and 100 mol% or less, more preferably 1 mol% or more and 100 mol% or less, and even more preferably 1 mol% or more and 80 mol% or less.

In addition, in the cyclic olefin copolymer (P), when the total content of the structural unit (A) and the structural unit (B) is taken as 100 mol%, the content of the structural unit (A) in the cyclic olefin copolymer is preferably 0.5 mol% or more and 100 mol% or less, more preferably 1 mol% or more and 100 mol% or less, and even more preferably 1 mol% or more and 80 mol% or less.
In this embodiment, the contents of the structural unit (A) and the structural unit (B) can be measured by, for example, ¹ H-NMR or ¹³ C-NMR.
By setting the content of each structural unit contained in the cyclic olefin copolymer (P) within the above numerical range, it is possible to obtain a cyclic olefin copolymer composition for medical devices which has a glass transition temperature that allows it to be molded into a shape such as a container, and which can give a molded article that generates a small amount of radicals when irradiated with gamma rays.

In the cyclic olefin copolymer (P) according to the present embodiment, the content of aromatic rings is preferably 0.01 mol% or more and 71 mol% or less, more preferably 0.1 mol% or more and 65 mol% or less, and even more preferably 0.2 mol% or more and 60 mol% or less. The content of aromatic rings is determined by calculating the peak area of hydrogen peaks ( ^6.7 to 7.3 ppm) derived from aromatic rings relative to the total area of all hydrogen-derived peaks detected by 1 H-NMR.
By setting the content of aromatic rings contained in the cyclic olefin copolymer (P) within the above numerical range, it is possible to obtain a cyclic olefin copolymer composition for medical devices which has a glass transition temperature that allows it to be molded into the shape of a container or the like, and which can give a molded article that generates a small amount of radicals when irradiated with gamma rays.

The copolymerization type of the cyclic olefin copolymer (P) according to the present embodiment is not particularly limited, and examples thereof include random copolymers, block copolymers, etc. In the present embodiment, from the viewpoint of obtaining a cyclic olefin copolymer composition for medical devices that has a glass transition temperature that can be molded into the shape of a container or the like and that can produce a molded product that generates a small amount of radicals when irradiated with gamma rays, it is preferable that the cyclic olefin copolymer (P) according to the present embodiment is a random copolymer.
The cyclic olefin copolymer (P) according to the present embodiment may be used alone or in combination of two or more.

(Method for Producing Cyclic Olefin Copolymer)
The method for producing the cyclic olefin copolymer (P) according to this embodiment is not particularly limited as long as it can obtain a cyclic olefin copolymer containing at least any one of the structural units (A) of (Ia), (II), and (III) above. For example, the cyclic olefin copolymer (P) can be obtained by first carrying out a step of obtaining a precursor polymer (precursor polymer polymerization step) and a step of partially hydrogenating the obtained precursor polymer (partial hydrogenation step).
That is, in the production of cyclic olefin ring-opening polymers, a hydrogenation step is generally carried out. In addition, when a hydrogenation step is carried out, even if the raw material monomer or the intermediate precursor polymer has an aromatic ring (e.g., a benzyl group), the benzyl group is reduced to a cyclohexane group in the hydrogenation step, so that the aromatic ring does not remain in the obtained cyclic olefin copolymer. For example, the cyclic olefin copolymer (P) according to the present invention is obtained by using a monomer having a benzyl functional group as a raw material, and performing partial hydrogenation to obtain a cyclic olefin copolymer having a cyclic olefin copolymer in the main chain and a specific structural unit (A) having a benzyl group in the side chain, and it is considered that a cyclic olefin copolymer composition for medical devices having a glass transition temperature that can be molded into the shape of a container or the like and capable of obtaining a molded product with a small amount of radical generation when irradiated with gamma rays can be realized.

[Precursor polymer polymerization step]
The precursor polymer according to this embodiment can be produced by appropriately selecting the conditions according to the methods described in, for example, JP-A-60-168708, JP-A-61-120816, JP-A-61-115912, JP-A-61-115916, JP-A-61-271308, JP-A-61-272216, JP-A-62-252406, JP-A-62-252407, JP-A-2007-314806, and JP-A-2010-241932.

[Partial hydrogenation process]
Examples of a method for partially hydrogenating the obtained precursor polymer include the method described in Stephen F. Hahn, An Improved Method for the Diimide Hydrogenation of Butadiene and Isoprene Containing Polymers, Journal of Polymer Science Part A: Polymer Chemistry, 30(3) 1992, and high-pressure hydrogenation using a palladium carbon catalyst.

The glass transition temperature (Tg) of the cyclic olefin copolymer (P) according to this embodiment, measured by a differential scanning calorimeter (DSC), is preferably 80°C or higher and 200°C or lower, more preferably 100°C or higher and 190°C or lower, and even more preferably 110°C or higher and 180°C or lower, from the viewpoint of further improving the heat resistance while maintaining good transparency of the resulting medical device.

The intrinsic viscosity [η] (in decalin at 135° C.) of the cyclic olefin copolymer (P) according to this embodiment is, for example, 0.05 to 5.0 dl/g, preferably 0.1 to 4.0 dl/g, more preferably 0.2 to 2.0 dl/g, and particularly preferably 0.3 to 1.0 dl/g.
When the intrinsic viscosity [η] is equal to or greater than the lower limit, the mechanical strength of the medical device can be improved, whereas when the intrinsic viscosity [η] is equal to or less than the upper limit, the moldability can be improved.

(styrene elastomer)
The styrene-based elastomer according to the present embodiment is an elastomer containing styrene as a monomer unit. The content of the monomer unit derived from styrene in the styrene-based elastomer may be, for example, 5% by mass or more, or 10% by mass or more, and may be, for example, 80% by mass or less, 75% by mass or less, or 70% by mass or less, when the entire styrene-based elastomer is taken as 100% by mass. 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.

The styrene-based elastomer according to the present embodiment 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 viewpoints of compatibility with the cyclic olefin copolymer (P) and impact resistance, the polyolefin block may contain at least one alkadiene of isoprene or butadiene as a monomer unit. In the present embodiment, an elastomer containing styrene and ethylene as monomer units is classified as a styrene-based elastomer.
The styrene-based elastomer according to the present embodiment 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. A triblock type copolymer can further contribute to improving the impact resistance of the molded article.
The content of the polyolefin block in the block copolymer as the styrene-based elastomer according to the present embodiment may be, for example, 95% by mass or less, or 90% by mass or less, or may be, for example, 5% by mass or more, 10% by mass or more, or 20% by mass or more, when the entire block copolymer is taken as 100% by mass. When the styrene-based elastomer contains an appropriate proportion of polyolefin blocks, a molded product having good properties in terms of transparency, impact resistance, rigidity, and stickiness is easily obtained.

Examples of the styrene-based elastomer according to the present embodiment include block copolymers (SBC) of a polystyrene block that serves as a hard portion (crystalline portion) and a conjugated diene monomer block such as isoprene or butadiene that serves as a soft portion; hydrogenated styrene-butadiene-styrene block copolymers (HSBR); styrene-ethylene-propylene-styrene block copolymers (SEPS); styrene-ethylene-butene-styrene block copolymers (SEBS); styrene-isoprene-styrene block copolymers (SIS); styrene-butadiene-styrene copolymers (SBS); styrene-isobutylene-styrene copolymers (SIBS); styrene-isobutylene copolymers (SIB); styrene-isoprene-butadiene-styrene block copolymers; styrene block copolymers (SIS); and hydrogenated copolymers of styrene/styrene-butadiene random copolymer/styrene block (SESS).
The styrene-based elastomer may be used alone or in combination of two or more kinds. Among these, the styrene-based elastomer is preferably at least one selected from styrene-ethylene-butene-styrene block copolymer (SEBS) and hydrogenated copolymer of styrene/styrene-butadiene random copolymer/styrene block copolymer (SESS).

An example of a commercially available hydrogenated styrene-butadiene-styrene block copolymer (HSBR) is Dynaron (registered trademark) manufactured by JSR Corporation.
Styrene-ethylene-propylene-styrene block copolymer (SEPS) is obtained by hydrogenating styrene-isoprene-styrene block copolymer (SIS). Examples of commercially available SIS products include JSR SIS (registered trademark) from JSR Corporation, Hybler (registered trademark) from Kuraray Co., Ltd., and Clayton D (registered trademark) from Shell Co., Ltd. Examples of commercially available SEPS products include Septon (registered trademark) from Kuraray Co., Ltd., and Clayton (registered trademark) from Shell Co., Ltd.
Examples of commercially available styrene-ethylene-butene-styrene block copolymers (SEBS) include Tuftec (registered trademark) from Asahi Kasei Corporation and Kraton (registered trademark) from Shell Corporation.
Examples of commercially available styrene-isobutylene-styrene copolymers (SIBS) or styrene-isobutylene copolymers (SIB) include SIBSTAR (registered trademark) available from Kaneka Corporation.
Examples of the SESS include S.O.E. (registered trademark) S1606, a product name of Asahi Kasei Corporation, and a mixture of S.O.E. (registered trademark) S1606 and S1605.

When the conjugated diene of the above block copolymer (SBC) or styrene-isoprene-styrene copolymer (SIS) is isoprene, the intermediate block is preferably vinyl-polyisoprene. In this case, the components derived from the conjugated diene constituting the intermediate block may be hydrogenated. Examples of such styrene-isoprene-styrene copolymers (SIS) include Hybler 5127 ("Hybler" is a registered trademark of the company) (styrene content 20% by mass, tan δ peak value = 1.1, peak value temperature = 19°C) manufactured by Kuraray Co., Ltd.

In addition, in the above-mentioned block copolymer (SBC) or styrene-butadiene-styrene copolymer (SBS), when the conjugated diene is butadiene, the butadiene-derived components may be hydrogenated. In addition, in this case, the butadiene block that becomes the soft part may be a copolymer of butadiene and styrene. Examples of such styrene-butadiene-styrene copolymer (SBS) include S.O.E.L609 ("S.O.E" is a registered trademark of the company) manufactured by Asahi Kasei Chemicals Corporation (styrene content = 67 mass%, tan δ peak value = 1.3, peak value temperature = 19°C), S.O.E.L606 (styrene content = 51 mass%, tan δ peak value = 1.7, peak value temperature = 8°C), and S.O.E.S1605 (styrene content = 67 mass%, tan δ peak value = 1.5, peak value temperature = 17°C).

Styrene-based elastomers can be produced by anionic polymerization of styrene and other conjugated dienes, which lead to the structural units constituting the polymer, using an alkyllithium compound as an initiator.
Examples of the alkyllithium compound include alkyllithium having an alkyl group having 1 to 10 carbon atoms, such as methyllithium, ethyllithium, pentyllithium, and butyllithium, naphthalenedilithium, and dithiohexylbenzyllithium.

Examples of the polymerization method include (1) a method in which styrene is sequentially polymerized followed by a conjugated diene using an alkyl lithium compound as an initiator, and then styrene is sequentially polymerized, and (2) a method in which styrene is sequentially polymerized followed by a conjugated diene, and then the resulting polymer is coupled with a coupling agent, etc. Examples of the coupling agent include dichloromethane, dibromomethane, dibromobenzene, etc.
In the polymerization, it is preferable to use a solvent in order to appropriately control the reaction. Examples of the solvent include organic solvents inert to the polymerization initiator, such as aliphatic high-hydrogen, alicyclic hydrocarbons having 6 to 12 carbon atoms, such as hexane, heptane, cyclohexane, methylcyclohexane, and benzene, and aromatic hydrocarbons.
The polymerization temperature is preferably from −70° C. to 80° C., and the polymerization time is preferably from 0.5 to 50 hours.

(Other ingredients)
If necessary, the cyclic olefin copolymer composition according to this embodiment may contain weathering stabilizers, heat stabilizers, antioxidants, metal deactivators, hydrochloric acid absorbers, antistatic agents, flame retardants, slip agents, antiblocking agents, antifogging agents, lubricants, natural oils, synthetic oils, waxes, organic or inorganic fillers, resins other than the cyclic olefin copolymer (P), and the like, to the extent that the object of the present invention is not impaired, and the blending ratios of the additives are appropriate.

The cyclic olefin copolymer composition according to this embodiment may contain a hindered amine compound [C], if necessary.
As the hindered amine compound [C] (hereinafter simply referred to as compound [C] or [C]), a compound having one or more hindered amine structures (specifically, a partial structure represented by the following formula (b1)) can be appropriately used.
In formula (b1), * represents a bond to another chemical structure.

Specific examples of compound [C] that can be used include compounds known as hindered amine light stabilizers (abbreviated as HALS).

Examples of compound [C] include the hindered amine compounds described in paragraphs [0058] to [0082] of WO 2006/112434, the hindered amine compounds described in paragraphs [0124] to [0186] of WO 2008/047468, the piperidine derivatives or salts thereof described in paragraphs [0187] to [0226] of WO 2008/047468, and the polyamine derivatives or salts thereof described in JP 2006-321793 A.

Also, Chimassorb 2020, Chimassorb 944, Tinuvin 622, Tinuvin PA144 Tinuvin 765, Tinuvin 770 (all manufactured by BASF), Cyasorb UV-3853, Cyasorb UV-3529, Cyasorb UV-3346, Cyasorb UV-531 (all manufactured by Cytec), Adeka STAB LA-52, Adeka STAB LA-57, Adeka STAB LA-63P, Adeka STAB LA-68, Adeka STAB LA-72, Adeka STAB LA-77Y, Adeka STAB LA-81, Adeka STAB LA-82, Adeka STAB Commercially available products such as LA-87 (manufactured by ADEKA) can be used.

In this embodiment, the compound [C] is preferably a compound having a structural unit represented by the following general formula (b2).
This compound is typically a polymer or oligomer. It is believed that the use of a compound [C] that is a polymer or oligomer such as this compound can increase the compatibility with the cyclic olefin copolymer (P) and make the composition more uniform. It is also believed that the structure is less likely to change to one that has characteristic absorption upon irradiation. This can be believed to reduce discoloration caused by electron beam or gamma ray irradiation and to reduce the generation of radicals caused by electron beam or gamma ray irradiation.

In formula (b2), X ₁ and X ₂ each independently represent a divalent linking group.
Examples of the divalent linking group of _X1 and _X2 include an alkylene group, a cycloalkylene group, an arylene group, a group in which these groups are linked, etc. Among these, an alkylene group is preferred, an alkylene group having 1 to 6 carbon atoms is more preferred, and an alkylene group having 1 to 4 carbon atoms is more preferred.
The compound having a structural unit represented by general formula (b2) may be a commercially available product, or may be obtained by condensation polymerization of the corresponding diol and dicarboxylic acid.

As for the compound [C], one type may be used alone, or two or more types may be used.
The content of the compound [C] in the composition is, for example, 0.01 to 2.0 parts by mass, preferably 0.05 to 1.5 parts by mass, and more preferably 0.10 to 1.0 parts by mass, relative to 100 parts by mass of the cyclic olefin copolymer (P). By setting the content within this range, discoloration and generation of radicals due to irradiation with electron beams or gamma rays can be effectively reduced while maintaining other performance properties (e.g., moldability, mechanical strength, etc.).

The cyclic olefin copolymer composition according to this embodiment may contain a phosphorus-based compound [D], if necessary.
There is no particular limitation on the phosphorus-based compound [D] (hereinafter, simply referred to as compound [D] or [D]) that can be used. For example, a known phosphorus-based antioxidant can be used.

The phosphorus-based antioxidant is not particularly limited, and any conventionally known phosphorus-based antioxidant (for example, a phosphite-based antioxidant) can be used.
Specifically, triphenyl phosphite, diphenyl isodecyl phosphite, phenyl diisodecyl phosphite, tris(nonylphenyl)phosphite, tris(dinonylphenyl)phosphite, tris(2,4-di-t-butylphenyl)phosphite, tris(2-t-butyl-4-methylphenyl)phosphite, tris(cyclohexylphenyl)phosphite, 2,2-methylenebis(4,6-di-t-butylphenyl)octylphosphite, monophosphite compounds such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene; 4,4'-butylidene-bis(3-methyl-6-t-butylphenyl-di-t 1,1,3-tris(2-methyl-4-di-tridecylphosphite-5-t-butylphenyl)butane, tetrakis(2,4-di-t-butylphenyl)-4,4'-biphenylene diphosphite, cyclic neopentane tetrayl bis(isodecyl phosphite), cyclic neopentane tetrayl bis(nonylphenyl phosphite), cyclic neopentane tetrayl bis(2,4-di-t-butylphenyl phosphite), cyclic neopentane tetrayl bis(2,4-dimethylphenyl phosphite), cyclic neopentane tetrayl bis(2,6-di-t-butylphenyl phosphite), and other diphosphite compounds.

The compound [D] preferably used is a trivalent organic phosphorus compound. More specifically, the compound [D] is a compound having a structure in which the three hydrogen atoms of phosphorous acid (P(OH) ₃ ) are each substituted with the same or different organic groups.
More specifically, compound [D] is preferably a compound represented by the following general formula (c1), (c2) or (c3).

In the general formulae (c1), (c2) and (c3),
R ¹ , when present in a plurality, each independently represents an alkyl group;
^R2 , when present in a plurality, each independently represents an aromatic group;
^R3 represents an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group;
X represents a single bond or a divalent linking group.

The alkyl group of ^R1 preferably has 1 to 10 carbon atoms, and more preferably is a t-butyl group.
Examples of the aromatic group for ^R2 include a phenyl group, a naphthyl group, and groups in which these groups are substituted with an alkyl group or the like.
^R3 preferably has 1 to 30 carbon atoms, more preferably 3 to 20 carbon atoms, and further preferably 6 to 18 carbon atoms.
^R3 is preferably an aryl group or an aralkyl group, more preferably an aralkyl group. These aryl groups or aralkyl groups may be further substituted with a substituent (e.g., an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, etc.).
When X is a divalent linking group, specific examples thereof include an alkylene group (such as a methylene group), an ether group (-O-), etc. X is preferably a single bond.

The compound [D] may be used alone or in combination of two or more.
The content of the compound [D] in the cyclic olefin copolymer composition is, for example, 0.01 to 1.5 parts by mass, preferably 0.02 to 1.0 parts by mass, and more preferably 0.05 to 0.5 parts by mass, when the amount of the cyclic olefin copolymer (P) contained in the cyclic olefin copolymer composition according to this embodiment is taken as 100 parts by mass. By setting the content within this range, discoloration and generation of radicals due to irradiation with electron beams or gamma rays can be effectively reduced while maintaining other performances (e.g., moldability, mechanical strength, etc.).

On the other hand, from another perspective, when the amount of the cyclic olefin copolymer (P) contained in the cyclic olefin copolymer composition according to this embodiment is taken as 100 parts by mass, the content of the phosphorus-based compound [D] in the cyclic olefin copolymer composition is preferably less than 0.05 parts by mass, more preferably 0.03 parts by mass or less, and even more preferably 0.02 parts by mass or less.

The cyclic olefin copolymer composition according to the present embodiment may contain a phenol-based stabilizer as a weather resistance stabilizer, if necessary.
Examples of the phenol-based stabilizer include hindered phenol-based stabilizers such as 3,3',3",5,5',5"-hexa-tert-butyl-a,a',a"-(methylene-2,4,6-triyl)tri-p-cresol, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenyl)benzylbenzene, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and thiodiethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; acrylate-based phenol compounds described in JP-A-63-179953 and JP-A-1-168643, such as 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-ethylphenol, octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylene-bis(4-methyl-6-t-butylphenol), 4,4'-butylidene-bis(6-t-butyl-m-cresol), 4,4'-thiobis(3-methyl-6-t-butylphenol), bis(3-cyclohexyl-2-hydroxy-5-methylphenyl)methane, 3,9-bis(2-(3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy)-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis(methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenylpropionate)methane [i.e., pentaerythrimethyl-tetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl propionate)], triethylene glycol bis(3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate), tocophenol and other alkyl-substituted phenol compounds; 6-(4-hydroxy-3,5-di-t-butylanilino)-2,4-bisoctylthio-1,3,5-triazine, 6-(4-hydroxy-3,5-dimethylanilino)-2,4-bisoctylthio-1,3,5-triazine, 6-(4-hydroxy-3-methyl-5-t-butylanilino)-2,4-bisoctylthio-1,3,5-triazine, 2-octylthio-4,6-bis-(3,5-di-t-butyl-4-oxyanilino)-1,3,5-triazine and other triazine group-containing phenol compounds;
When the amount of the cyclic olefin copolymer (P) contained in the cyclic olefin copolymer composition according to this embodiment is taken as 100 parts by mass, the content of the phenol-based stabilizer in the cyclic olefin copolymer composition is preferably less than 0.05 parts by mass, more preferably 0.03 parts by mass or less, and even more preferably 0.02 parts by mass or less.

The cyclic olefin copolymer composition according to this embodiment can be obtained by a method of melt-kneading the cyclic olefin copolymer (P), the styrene-based elastomer, and other components using a known kneading device such as an extruder or a Banbury mixer; a method of dissolving the cyclic olefin copolymer (P), the styrene-based elastomer, and other components in a common solvent and then evaporating the solvent; a method of adding a solution of the cyclic olefin copolymer (P), the styrene-based elastomer, and other components to a poor solvent and causing precipitation, and the like.

[Molded body]
The molded article according to this embodiment is a molded article containing the cyclic olefin copolymer composition for a medical device according to this embodiment.

In addition, from the viewpoint of further improving the performance balance of radiation resistance, impact resistance, and transparency of the above-mentioned molded article, the total content of the cyclic olefin copolymer (P) and the styrene-based elastomer in the molded article according to this embodiment is preferably 50% by mass or more and 100% by mass or less, more preferably 70% by mass or more and 100% by mass or less, even more preferably 80% by mass or more and 100% by mass or less, and particularly preferably 90% by mass or more and 100% by mass or less, when the entire molded article is taken as 100% by mass.

The molded article according to this embodiment can be obtained by molding the cyclic olefin copolymer composition for medical devices, which contains the cyclic olefin copolymer (P) and a styrene-based elastomer, into a predetermined shape. The method for molding the cyclic olefin copolymer composition for medical devices to obtain a molded article is not particularly limited, and any known method can be used. Depending on the application and shape, for example, extrusion molding, injection molding, compression molding, inflation molding, blow molding, extrusion blow molding, injection blow molding, press molding, vacuum molding, powder slush molding, calendar molding, foam molding, etc. can be applied. Among these, the injection molding method is preferred from the viewpoint of moldability and productivity. In addition, the molding conditions are appropriately selected depending on the purpose of use or the molding method, and for example, the resin temperature in injection molding is appropriately selected in the range of usually 150°C to 400°C, preferably 200°C to 350°C, and more preferably 230°C to 330°C.

In addition, in the cyclic olefin copolymer composition for medical devices according to this embodiment, from the viewpoint of further improving the transparency of the obtained molded article, when an injection-molded sheet having a thickness of 2.0 mm is produced from the cyclic olefin copolymer composition for medical devices, the haze of the injection-molded sheet measured in accordance with JIS K7136 is preferably less than 5%.

The molded article according to this embodiment contains the cyclic olefin copolymer composition for medical devices according to this embodiment, and therefore has good moldability during molding, high transparency, a glass transition temperature that allows it to be molded into the shape of a container or the like, and generates a small amount of radicals when irradiated with gamma rays. Therefore, it is suitable for medical devices. The molded article according to this embodiment can be, for example, a catheter member, a sterilized sheet, a medical container, a biochip, or a medical film.

[Medical Instruments]
Next, a medical device according to an embodiment of the present invention will be described.
The medical device according to this embodiment contains the cyclic olefin copolymer composition according to this embodiment.
Since the medical device according to the present embodiment contains a cyclic olefin copolymer composition, it has an excellent balance of impact resistance, transparency, and gamma ray or electron ray resistance. This medical device is less susceptible to discoloration due to electron ray or gamma ray irradiation.
According to another study by the present inventors, it has become clear that conventional medical instruments may generate radicals when irradiated with electron beams or gamma rays, which may cause a risk of deterioration of the contents after filling a medical container, such as a medical solution storage container.
In contrast, the medical device according to the present embodiment can reduce the amount of radicals generated by electron beam or gamma ray irradiation, and therefore the medical device according to the present embodiment can reduce the risk of deterioration of the contents.

In addition, for example, by irradiating the medical instrument manufactured as described above with gamma rays or electron beams, a gamma ray or electron beam irradiated medical instrument (a medical instrument irradiated with gamma rays or electron beams) can be obtained. This medical instrument is clean because it has been sterilized or disinfected by irradiation, and discoloration and generation of radicals are suppressed. The irradiation dose is not particularly limited, but is usually 5 to 100 kilograys (kGy), preferably 10 to 80 kilograys.

Examples of medical devices include catheter members, sterilized sheets, medical containers, biochips, and medical films.
Examples of medical containers include syringes used in syringe barrels (hereinafter referred to as syringes) and syringes filled with medicinal liquids or medicines (hereinafter also referred to as prefilled syringes), and storage containers used in storage containers filled with medicinal liquids or medicines (hereinafter also referred to as medicinal liquid storage containers).

Here, a prefilled syringe is a syringe-shaped preparation that is prefilled with a medicinal liquid or drug, and there are single-chamber types filled with one type of liquid and double-chamber types filled with two types of drugs. Most prefilled syringes are single-chamber types, but double-chamber types include liquid/powder type preparations consisting of a powder and its dissolving liquid, and liquid/liquid type preparations consisting of two types of liquid. An example of the internal solution of the single-chamber type is heparin solution. Examples of syringes used for syringes and prefilled syringes include prefillable syringes, prefilled syringes for vaccines, prefilled syringes for anticancer drugs, needleless syringes, etc.

Examples of the drug solution storage container include wide-mouthed bottles, narrow-mouthed bottles, medicine bottles, vials, infusion bottles, bulk containers, petri dishes, test tubes, analytical cells, etc. More specifically, examples include liquid, powder or solid drug containers such as ampoules, press-through packages, infusion bags, drip medicine containers, eye drop containers, etc.; sample containers such as blood test sampling test tubes, blood collection tubes, and specimen containers; analytical containers such as ultraviolet inspection cells; sterilized containers for medical instruments such as scalpels, forceps, gauze, and contact lenses; medical tools such as disposable syringes and prefilled syringes; laboratory instruments such as beakers, vials, ampoules, and test tube flasks; and housings for artificial organs.
A biochip is a chip on which a biomolecule such as DNA, protein, or sugar chain is fixed, and examples of the biochip include DNA analysis chips, protein analysis chips, and testing and diagnostic tools that utilize the chips. In a broader sense, the biochip also includes biosensors.
Examples of medical films include packaging materials for infusion bags and blood transfusion bags; adhesive packaging materials (such as tapes for attaching to the skin); wound dressings; packaging materials for solid and liquid substances such as tablets, capsules, powders, and solvents; packaging materials for PTPs (press through packs); blister packs, etc.

The medical device according to this embodiment has good transparency, which is evaluated by internal haze.
Furthermore, it is preferable that the light transmittance is good. The light transmittance is defined as a spectral light transmittance or a total light transmittance depending on the application.

When use in all light or multiple wavelength regions is expected, good total light transmittance is required, and the total light transmittance without an anti-reflection film on the surface is 85% or more, preferably 88 to 93%. If the total light transmittance is 85% or more, the required amount of light can be secured. The total light transmittance can be measured by a known method, and the measuring device is not limited. For example, a method in accordance with ASTM D1003 is used in which the cyclic olefin copolymer composition according to this embodiment is molded into a sheet having a thickness of 3 mm, and the total light transmittance of the sheet obtained by molding the cyclic olefin copolymer composition according to this embodiment is measured using a haze meter.

Moreover, the medical device according to this embodiment has excellent light transmittance for light with wavelengths of 450 nm to 800 nm.
The light transmittance can be further improved by providing a known anti-reflection film on the surface.

Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can also be adopted.
Furthermore, the present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of the present invention that can achieve the object of the present invention are included in the present invention.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto.

<Production of Cyclic Olefin Copolymer>
First, a precursor polymer of a cyclic olefin copolymer was obtained by the following method.

[Production Example 1]
17.3 ml of tetracyclododecene (tetracyclo[6.2.1.1(3,6).0(2,7)]dodec-4-ene, see formula (1) below, also referred to as TD below), 140 ml of dehydrated toluene, and 0.11 ml of hexadiene were placed in a 500 ml glass reactor that had been thoroughly purged with nitrogen, and the mixture was heated to 50° C. and stirred. 5.9 mg of Grubbs Catalyst ^™ 2nd Generation was added as a catalyst, and the reaction was carried out with stirring. After 10 minutes, 1 ml of butyraldehyde was added dropwise to terminate the reaction.
About 150 ml of the solution obtained after the reaction was dropped into 1,400 ml of acetone to cause crystallization, which was then filtered through Kiriyama filter paper (5B) and dried under reduced pressure at 80° C. to obtain 13 g of a polymer. Hereinafter, this polymer is referred to as RTD.

[Production Example 2]
In a 500 ml glass reactor that had been thoroughly purged with nitrogen, 17.0 ml of tetracyclododecene, 0.4 ml of indene norbornene (1,4,4a,9a tetrahydro-1,4 methanofluorene, see formula (2) below, also referred to as IndNB), 140 ml of dehydrated toluene, and 0.11 ml of hexadiene were placed, heated to 50° C., and stirred. 5.9 mg of Grubbs Catalyst ^™ 2nd Generation was placed as a catalyst, and the reaction was allowed to proceed with stirring. After 10 minutes, 1 ml of butyraldehyde was added dropwise to terminate the reaction.
About 150 ml of the solution obtained after the reaction was dropped into 1,400 ml of acetone for crystallization, filtered through Kiriyama filter paper (5B), and dried under reduced pressure at 80° C. to obtain 13 g of a polymer. Hereinafter, this polymer is referred to as RTD-IndNB2.

[Production Example 3]
In a 500 ml glass reactor that had been thoroughly purged with nitrogen, 16.9 ml of tetracyclododecene, 0.9 ml of indene norbornene, 140 ml of dehydrated toluene, and 0.11 ml of hexadiene were placed, heated to 50° C., and stirred. 5.9 mg of Grubbs Catalyst ^™ 2nd Generation was placed as a catalyst, and the mixture was reacted with stirring. After 10 minutes, 1 ml of butyraldehyde was added dropwise to terminate the reaction.
About 150 ml of the solution obtained after the reaction was dropped into 1,400 ml of acetone for crystallization, filtered through Kiriyama filter paper (5B), and dried under reduced pressure at 80° C. to obtain 13 g of a polymer. Hereinafter, this polymer is referred to as RTD-IndNB5.

[Production Example 4]
In a 500 ml glass reactor that had been thoroughly purged with nitrogen, 17.0 ml of tetracyclododecene, 0.3 ml of benzonorbornadiene (see formula (3) below, hereinafter also referred to as BNBD), 140 ml of dehydrated toluene, and 0.11 ml of hexadiene were placed, heated to 50° C., and stirred. 5.9 mg of Grubbs Catalyst ^™ 2nd Generation was placed as a catalyst, and the reaction was carried out with stirring. After 10 minutes, 1 ml of butyraldehyde was added dropwise to terminate the reaction.
About 150 ml of the solution obtained after the reaction was dropped into 1,400 ml of acetone for crystallization, filtered through Kiriyama filter paper (5B), and dried under reduced pressure at 80° C. to obtain 13 g of a polymer. Hereinafter, this polymer is referred to as RTD-BNBD2.

[Production Example 5]
In a 500 ml glass reactor that had been thoroughly purged with nitrogen, 13.9 ml of tetracyclododecene, 3.8 ml of indene norbornene, 140 ml of dehydrated toluene, and 0.11 ml of hexadiene were placed, heated to 50° C., and stirred. 5.9 mg of Grubbs Catalyst ^™ 2nd Generation was placed as a catalyst, and the mixture was reacted with stirring. After 10 minutes, 1 ml of butyraldehyde was added dropwise to terminate the reaction.
About 150 ml of the solution obtained after the reaction was dropped into 1,400 ml of acetone for crystallization, filtered through Kiriyama filter paper (5B), and dried under reduced pressure at 80° C. to obtain 13 g of a polymer. Hereinafter, this polymer is referred to as RTD-IndNB20.

The precursor polymer was obtained by the above method. The obtained precursor polymer was then partially or fully hydrogenated by the following method.

[Production of Cyclic Olefin Copolymer P-1 (Partial Hydrogenation)]
13 g of RTD-IndNB2 and 600 ml of o-xylene were placed in a 1 L glass reactor that had been thoroughly substituted with nitrogen, dissolved, and heated to 140°C while stirring, and refluxed. Next, 30.5 g of p-toluenesulfonylhydrazide and 23.4 g of tri-n-propylamine were added to start the reaction. Four hours after the start of the reaction, the temperature was lowered to room temperature to terminate the reaction, and about 600 ml of reaction solution was obtained. As in the above-mentioned production example, this reaction solution was dropped into 1800 ml of acetone to cause crystallization, filtered with Kiriyama filter paper (5B), and dried under reduced pressure at 80°C to obtain 13 g of polymer.
NMR observation of this polymer revealed that the aromatic rings remained, but other double bonds were almost completely absent.

[Production of Cyclic Olefin Copolymers P-2 and P-3]
Cycloolefin copolymers P-2 and P-3 were obtained by carrying out a partial hydrogenation step in the same manner as in the production of cyclic olefin copolymer P-1, except that a polymer shown in Table 1 was used instead of RTD-IndNB2. When cyclic olefin copolymers P-2 and P-3 were observed by NMR in the same manner as in cyclic olefin copolymer P-1, aromatic rings remained, but other double bonds were almost completely removed.

[Production of Cyclic Olefin Copolymer P-4 (Total Hydrogenation)]
Into an autoclave that had been thoroughly purged with nitrogen, 13 g of RTD, 277 g of cyclohexane, 0.08 g of bis(tricyclohexylphosphine)benzylidine ruthenium (IV) dichloride, and 4.7 g of ethyl vinyl ether were placed, hydrogen pressure was applied at 8 atmospheres, and the temperature was raised to 120°C, and the reaction was carried out for 10 hours.
In the same manner as in the above-mentioned Production Example, this reaction solution was dropped into 1800 ml of acetone to cause crystallization, which was then filtered through Kiriyama filter paper (5B) and dried under reduced pressure at 80° C. to obtain 13 g of polymer.
NMR observation of this polymer revealed that aromatic rings and other double bonds were almost completely eliminated.

[Production of Cyclic Olefin Copolymer P-5]
Cycloolefin copolymer P-5 was obtained by carrying out a hydrogenation step in the same manner as in the production of cyclic olefin copolymer P-4, except that the polymer shown in Table 1 was used instead of RTD. When the cyclic olefin copolymer was observed by NMR in the same manner as in the case of cyclic olefin copolymer P-4, aromatic rings and other double bonds were almost completely eliminated.

<Styrene-based elastomer>
As the styrene-based elastomer, the following was used.

S-1: SEBS (Tuftec (trademark) H1043 manufactured by Asahi Kasei Corporation, refractive index nD: 1.548, styrene content: 67% by mass)
S-2: SEBS (Tuftec (trademark) H1051 manufactured by Asahi Kasei Corporation, refractive index nD: 1.522, styrene content: 42% by mass)
S-3: SESS (S.O.E. (trademark) S1606 manufactured by Asahi Kasei Corporation, styrene content: 51% by mass)

<Other elastomers>
As elastomers other than the styrene-based elastomer, the following were used.

A-1: Acrylic rubber produced by the following method: 15.3 g of butyl acrylate, 0.39 g of glycidyl methacrylate, and 1.32 g of ethyl acetate were mixed to prepare a monomer liquid. 0.27 g of 2,2'-azobis(2,4-dimethylvaleronitrile) was dissolved in 3.87 g of ethyl acetate as an initiator. 10.3 g of ethyl acetate was placed in a glass container, heated to 78°C, and refluxed. The monomer liquid was dropped into the glass container over 5 hours, and the initiator was dropped over 8 hours at the same time. A portion of the solvent was removed with an evaporator, and 29 g of acrylic rubber was obtained. When measured by GPC, the Mw was 75,000. When measured by a B-type viscometer, the viscosity was 250 mPa·s.

N-1: Nitrile rubber produced by the following method 15.3g of butyl acrylate, 0.51g of glycidyl methacrylate, 4.14g of acrylonitrile, 0.63g of butyl methacrylate, and 6.9g of ethyl acetate were mixed to obtain a monomer liquid. 0.18g of 2,2'-azobis(2,4-dimethylvaleronitrile) was dissolved in 3g of ethyl acetate as an initiator. 9g of ethyl acetate was placed in a glass container, heated to 78°C, and refluxed. The monomer liquid was dropped into the glass container over 5 hours, and the initiator was dropped over 8 hours at the same time. A part of the solvent was removed with an evaporator, and 20g of nitrile rubber was obtained. When measured by GPC, the Mw was 53,600. In addition, when measured by a B-type viscometer, the viscosity was 500mPa·s.

<Examples 1 to 3 and Comparative Examples 1 to 4>
In each of the Examples and Comparative Examples, various physical properties were measured or evaluated by the following methods, and the results are shown in Tables 1 and 2.

(Evaluation of Cyclic Olefin Copolymers)
[Intrinsic viscosity]
The intrinsic viscosity ([η]) was measured in decalin at 135°C.
Specifically, the resin (about 20 mg) was dissolved in decalin solvent (15 ml) and the specific viscosity η _sp was measured in an oil bath at 135 ° C. The decalin solution was diluted with additional decalin solvent (5 ml), and then the specific viscosity η _sp was measured in the same manner as described above. This dilution operation was repeated two more times, and the value of η _sp /C when the concentration (C) of the sample was extrapolated to 0 was taken as the limiting viscosity [η].
Intrinsic viscosity [η] = lim (η _sp / C) (C → 0)

[Glass transition temperature Tg (°C)]
The DSC measurement was carried out under the following conditions.
Equipment: DSC7000, manufactured by SII NanoTechnology
Measurement conditions: Under a nitrogen atmosphere, the temperature was raised from room temperature to 260° C. at a heating rate of 10° C./min, and then held for 5 minutes. The temperature was then lowered to 30° C. at a heating rate of 10° C./min, and then held for 5 minutes. Then, a DSC curve was obtained during the process of raising the temperature to 260° C. at a heating rate of 10° C./min.

In the obtained DSC curve, the temperature at the point where a line equidistant in the vertical direction from the extended straight line of each baseline intersects with the curve of the step-like change in the glass transition was taken as the glass transition temperature.

[ ^1H -NMR Measurement]
The cyclic olefin copolymer was subjected to ¹ H-NMR measurement by the following method to confirm the presence or absence of aromatic rings and double bonds.
Measurement was carried out from 0.5 ppm to 8 ppm using ^{a 1} H-NMR spectrometer manufactured by JEOL Ltd. to confirm the presence or absence of hydrogen peaks (6.7 to 7.3 ppm) derived from aromatic rings and peaks derived from other double bonds.
In addition, the content of the structural unit (A) in the cyclic olefin copolymer and the aromatic ring content in the cyclic olefin copolymer were calculated by the following method when the total content of the structural unit (A) and the structural unit (B) was taken as 100 mol %.
The amount of hydrogen in the aromatic ring contained in ^the polymer was calculated by calculating the peak area of the peak (6.7 to 7.3 ppm) derived from the hydrogen in the aromatic ring relative to the total area of all peaks derived from hydrogen detected at 0.5 ppm to 8 ppm by 1 H-NMR manufactured by JEOL Ltd.

(Evaluation of Molded Product)
[Pelletization]
0.1 part by mass of tri(2,4-di-t-butylphenyl)phosphate as a secondary antioxidant and 0.1 part by mass of n-octadecyl-3-(4'-hydroxy-3',5'-di-t-butylphenyl)propionate as a heat stabilizer were blended with 100 parts by mass of a cyclic olefin copolymer composition obtained by mixing the cyclic olefin copolymer and the styrene-based elastomer in the blending amounts shown in Table 2. Next, the mixture was granulated using a twin-screw extruder BT-30 (screw system 30 mmφ, L/D=46) manufactured by Plastics Engineering Research Institute under conditions of a set temperature of 270°C, a resin extrusion rate of 80 g/min, and 200 rpm to obtain pellets for various measurements.

[injection molding]
The pellets obtained above were injection molded using a Toshiba Machine Co., Ltd. injection molding machine IS-55EPN (mold clamping force 53t, diver spacing 310mm x 310mm, injection volume ^69cm3 , screw diameter 23mmφ, stroke 60mm) under conditions of cylinder temperature = 250-290°C, injection speed = 20-40%, screw rotation speed 70rpm, and mold temperature 80°C to produce a 2mm thick injection square plate and a bending test specimen (127 x 13mm, 1/8 inch (3.1mm) thick).

[Amount of radicals generated]
Each of the obtained samples (square plate test pieces with a thickness of 2 mm) was irradiated with 50 kilograys of gamma rays, and the amount of radicals generated was measured after 5 days.
The amount of radicals was measured by electron spin resonance (ESR).
Specifically, about 6 mg of the test piece was cut out immediately after gamma ray irradiation, placed in a test tube (details below), and the ESR spectrum was measured under the following conditions.

・Apparatus: JEOL Electron Spin Resonance Apparatus JES-TE200
Resonant frequency: 9.2 GHz
Microwave input: 1mW
Central magnetic field: 326.5 mT
Sweep width: ±15mT
Modulation frequency: 100kHz
Sweep time: 8 min.
Time constant: 0.1 sec
Amplification level: 25
Sample tube: X-band compatible quartz tip sample tube External targeting: Mn ²⁺ standard sample supported on magnesium oxide External standard memory: 0,700
Measurement temperature: room temperature Measurement atmosphere: air For relative comparison of the amount of radicals generated, the normalized value shown in the following formula was used.

なお、ＥＳＲスペクトルのベースラインについては、Ｍｎ^２＋（第２シグナル）を基準とし補正した。
通常、ラジカル量の相対比較において、基準となるＭｎ^２＋由来シグナルの面積はＭｎ^２＋（第３シグナル）を用いる。しかし、有機ラジカル由来ラジカルのスペクトルと、Ｍｎ^２＋（第３シグナル）とが重なるため、今回の測定ではすべてＭｎ^２＋（第２シグナル）を用いた（外部標準メモリ＝７００）。
また、有機ラジカル由来シグナルがＭｎ^２＋（第３シグナル）と重なった場合は、外部標準メモリ＝０のＥＳＲスペクトルを用いて算出した。

The baseline of the ESR spectrum was corrected based on Mn ²⁺ (second signal).
Usually, in the relative comparison of radical amounts, Mn ²⁺ (third signal) is used as the reference for the area of the Mn ²⁺ derived signal. However, since the spectrum of the organic radical derived radical overlaps with Mn ²⁺ (third signal), Mn ²⁺ (second signal) was used in all measurements this time (external standard memory = 700).
When the signal derived from an organic radical overlapped with Mn ²⁺ (third signal), the calculation was performed using an ESR spectrum with an external standard memory of 0.

[Impact resistance]
In accordance with the ASTM D790 standard, an ASTM (1/8 inch) ejected piece (the above bending test piece (1/8 inch)) was used as an evaluation sample, and an Instron tensile tester (Instron 1123) was used to perform testing at a span distance of 51 mm and a test speed of 20 mm/min in an atmosphere of 23° C. to determine the maximum impact point E (J). The larger the maximum impact point E (J), the more excellent the impact resistance.

Claims (9)

A cyclic olefin copolymer having an aromatic ring, the cyclic olefin copolymer including at least one structural unit (A) selected from the following (Ia), (II), and (III):
A styrene-based elastomer,
A cyclic olefin copolymer composition for a medical device, comprising:
the content of the styrene-based elastomer is 11 parts by mass or more and 50 parts by mass or less when the total amount of the cyclic olefin copolymer and the styrene-based elastomer contained in the cyclic olefin copolymer composition for medical devices is 100 parts by mass,
The glass transition temperature (Tg) of the cyclic olefin copolymer measured by a differential scanning calorimeter (DSC) is 80° C. or higher and 200° C. or lower;
The cyclic olefin copolymer further contains a structural unit (B) derived from an olefin having 2 to 20 carbon atoms,
The structural unit (B) contains a structural unit derived from a compound represented by the following formula (B-1):
A cyclic olefin copolymer composition for a medical device , wherein the cyclic olefin copolymer has an aromatic ring content of 0.2 mol % or more and 1.0 mol % or less.

(In the above formula (Ia), n is 0, 1 or 2; R ¹ to R ¹⁴ each independently represent a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom; at least one of R ¹¹ to R ¹⁴ is a bond; and either (Ib) or (Ic) is bonded to each of the one or more bonding types independently.)

(In the above formula (Ib), n is 0 to 20, q is 0, 1 or 2, R ¹⁵ to R ²⁴ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted by a halogen atom other than a fluorine atom, one of R ¹⁷ to R ²⁴ is a bond, and when q=0, R ¹⁷ and R ¹⁸ , R ¹⁸ and R ¹⁹ , R ¹⁹ and R ²⁰ , R ²⁰ and R ²¹ , R ²¹ and R ²² , and R ²² and R ¹⁷ may be bonded to each other to form a monocyclic or polycyclic ring, and when q=1 or 2, R ¹⁷ and R ¹⁸ , R ¹⁸ and R ²⁴ , R ²⁴ and R ²⁴ , R ²⁴ and R ¹⁹ , R ¹⁹ and R ²⁰ , R ²⁰ and R ²¹ , and R ^R21 and ^R22 , ^R22 and ^R23 , ^R23 and ^R23 , and ^R23 and ^R17 may be bonded to each other to form a monocycle or polycycle, and the monocycle or polycycle may have a double bond, or the monocycle or polycycle may be an aromatic ring.

(In the above formula (Ic), n is 0 to 20, m and g are each independently 0 to 10, r is 1, 2 or 3, R ²⁵ to R ³⁵ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom, and when r=1, R ³² and R ³³ , R ³³ and R ³⁴ , and R ³⁴ and R ³⁵ may be bonded to each other to form a monocycle or polycycle, and when r=2 or 3, R ³² and R ³² , R ³² and R ³³ , R ³³ and R ³⁴ , R ³⁴ and R ³⁵ , and R ³⁵ and R ³⁵ may be bonded to each other to form a monocycle or polycycle, and the monocycle or polycycle may have a double bond, and the monocycle or polycycle may be an aromatic ring.)

(In the above formula (II), n, m and g are each independently 0, 1 or 2; r is 1, 2 or 3; R ³⁶ to R ⁵⁵ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom; when r=1, R ⁵² and R ⁵³ , R ⁵³ and R ⁵⁴ , and R ⁵⁴ and R ⁵⁵ may be bonded to each other to form a monocycle or a polycycle; when r=2 or 3, R ⁵² and R ⁵² , R ⁵² and R ⁵³ , R ⁵³ and R ⁵⁴ , R ⁵⁴ and R ⁵⁵ , and R ⁵⁵ and R ⁵⁵ may be bonded to each other to form a monocycle or a polycycle, the monocycle or the polycycle may have a double bond, or the monocycle or the polycycle may be an aromatic ring; and R ⁴⁸ and R ⁵⁰ may be bonded to each other to form a monocyclic or polycyclic ring, the monocyclic or polycyclic ring may have a double bond, or the monocyclic or polycyclic ring may be an aromatic ring.

(In the above formula (III), n is 0, 1 or 2, m is 1, 2 or 3, R ⁵⁵ to R ⁶⁸ are each independently a hydrogen atom, a halogen atom other than a fluorine atom, or a hydrocarbon group having 1 to 20 carbon atoms which may be substituted with a halogen atom other than a fluorine atom, and when m=1, R ⁶⁵ and R ⁶⁷ , R ⁶⁷ and R ⁶⁸ , and R ⁶⁸ and R ⁶⁶ may be bonded to each other to form a monocycle or polycycle, and when m=2 or 3, R ⁶⁵ and R ⁶⁵ , R ⁶⁵ and R ⁶⁷ , R ⁶⁷ and R ⁶⁸ , R ⁶⁸ and R ⁶⁶ , and R ⁶⁶ and R ⁶⁶ may be bonded to each other to form a monocycle or polycycle, the monocycle or polycycle may have a double bond, and the monocycle or polycycle may be an aromatic ring.)

(In the above formula [B-1], n is 0 or 1, m is 0 or a positive integer, q is 0 or 1, R ¹ to R ¹⁸ , and R ^a and R ^b are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group which may be substituted with a halogen atom, and R ¹⁵ to R ¹⁸ may be bonded to each other to form a monocyclic or polycyclic ring, and the monocyclic or polycyclic ring may have a double bond, and R ¹⁵ and R ¹⁶ , or R ¹⁷ and R ¹⁸ may be combined to form an alkylidene group, but does not include an aromatic ring.) The cyclic olefin copolymer composition for medical devices according to claim 1,
A cyclic olefin copolymer composition for a medical device, wherein the content of the structural unit (A) in the cyclic olefin copolymer is 0.2 mol % or more and 100 mol % or less. The cyclic olefin copolymer composition for medical devices according to claim 1 or 2 ,
The structural unit (B) comprises ^at least one structural unit selected from ^the group consisting of a structural unit derived from bicyclo[ ^2.2.1 ]-2-heptene, a structural unit derived from tetracyclo[ ^{4.4.0.12,5.17,10} ]-3-dodecene, a structural unit derived from hexacyclo[ ^{6,6,1,13,6,110,13,02,7,09,14} ] ^heptadecene -4, a structural unit derived from ethylnorbornene, a structural unit derived from dicyclopentadiene, a structural unit derived from a hydride of dicyclopentadiene, and a structural unit derived from tricycloundecene. The cyclic olefin copolymer composition for a medical device according to any one of claims 1 to 3 ,
The cyclic olefin copolymer composition for medical devices, wherein the structural unit (B) has an alicyclic structure. The cyclic olefin copolymer composition for a medical device according to any one of claims 1 to 4 ,
A cyclic olefin copolymer composition for a medical device, wherein the content of the structural unit (A) in the cyclic olefin copolymer is 0.5 mol % or more and 100 mol % or less, when the total content of the structural unit (A) and the structural unit (B) in the cyclic olefin copolymer is 100 mol %. The cyclic olefin copolymer composition for a medical device according to any one of claims 1 to 5 ,
A cyclic olefin copolymer composition for medical devices, wherein the structural unit (A) is derived from at least one selected from the group consisting of benzonorbornadiene, indenenorbornene, and methylphenylnorbornene. A molded article comprising the cyclic olefin copolymer composition for a medical device according to any one of claims 1 to 6 . The molded article according to claim 7 , which is a medical device. The molded article according to claim 8 , wherein the medical device is a catheter member, a sterilized sheet, a medical container, a biochip, or a medical film.