JP2016022145A - Medical instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical instrument which includes a housing made of a cyclic polyolefin resin and a gasket made of a thermoplastic elastomer composition and is free from problems such as whitening of the housing when the medical instrument is subjected to heating conditions in a sterilization treatment or the like and adhesion of the housing and the gasket.SOLUTION: A thermoplastic elastomer composition constituting a gasket includes a component (A): a block copolymer having at least two polymer blocks P which are mainly made of a vinyl aromatic compound and at least one polymer block Q which is mainly made of conjugated dienes and/or a hydrogenated block copolymer obtained by hydrogenation of the block copolymer, a component (B): a softening agent for a polybutene-based rubber, and a component (C): a polyolefin resin. The content of the component (A) relative to a total of the component (A) and the component (B) is 25- 90 wt.%. The content of the component (C), based on a total 100 pts.wt. of the component (A) and the component (B), is 1-45 pts.wt.SELECTED DRAWING: None

Description

  The present invention relates to a medical device, and more particularly, a medical device having a casing made of a cyclic polyolefin resin and a gasket made of a thermoplastic elastomer composition, which has been exposed to heating conditions by sterilization or the like. The present invention relates to a medical instrument that solves the problem of whitening of a casing and adhesion between the casing and a gasket.

  In recent years, plastic medical containers have been widely used as pharmaceutical containers because they are lightweight, inexpensive, less damaged by dropping, and easy to mold. In recent years, an outer cylinder whose tip of a syringe is sealed is filled with a drug solution or an injection solution, and the other end of the syringe is transported and stored with a gasket sealed, and a syringe needle or administration device is placed at the tip of the syringe. A prefilled syringe that administers a drug solution or an injection solution by inserting a gasket and sliding the inside of the syringe by pushing in a gasket has begun to be used. Prefilled syringes are easy to operate, and since they are already filled with chemicals, there is no need to prepare drugs on-site, which not only prevents bacterial infection, but also shortens dispensing time. Has the advantage of For this reason, in the recent medical field, prefilling of various drugs has been desired from the viewpoint of improving the efficiency of treatment and preventing medical errors.

  As the material of the syringe in the prefilled syringe, a cyclic polyolefin resin is used from the viewpoint of chemical resistance and heat resistance, and non-adsorption to the stored medicine, while the gasket maintains airtightness with the syringe inner wall surface. Since it must slide, a technique of forming with an elastomer such as butyl rubber or a thermoplastic elastomer composition is disclosed (for example, Patent Document 1).

  However, elastomers such as butyl rubber contain many additives such as plasticizers, crosslinking agents, and pigments, and these additives may elute into the chemical solution filled in the syringe. A complicated cleaning process is required.

  On the other hand, with respect to the thermoplastic elastomer composition constituting the gasket, several proposals have been made to improve slidability, stress relaxation characteristics, flow rise characteristics, and pulsation properties. A block having a polymer block mainly composed of an aromatic compound, a block copolymer and / or a hydrogenated block copolymer having a polymer block mainly composed of a conjugated diene, a softener for hydrocarbon rubber, a polyolefin resin, Has been proposed. The thermoplastic elastomer composition of Patent Document 2 includes a hydrocarbon rubber softener for imparting rubber elasticity to a block copolymer and / or a hydrogenated block copolymer, and processability and hardness adjustment. It is described that it is formed by blending a polyolefin resin for the purpose.

  Patent Document 1 proposes a gasket in which a wetted surface of a gasket is coated with a cyclic polyolefin-based resin. However, this requires a gasket coating step in the product manufacturing process.

JP 2009-207619 A JP 2012-197829 A

  As a result of detailed studies by the present inventors, the thermoplastic elastomer composition of Patent Document 2 contains a hydrocarbon-based rubber softener such as paraffin oil as a rubber softener. It was found that when a gasket made of the composition was attached to a syringe made of a cyclic polyolefin resin, there was a problem that the gasket adhered to the syringe or the contact part whitened under the heating conditions during sterilization treatment. .

  The present invention is a medical instrument having a casing made of a cyclic polyolefin resin and a gasket made of a thermoplastic elastomer composition, and the casing is whitened or exposed when it is exposed to heating conditions such as sterilization. It is an object of the present invention to provide a medical device that does not have a problem of adhesion between a body and a gasket.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained a thermoplastic elastomer composition in a medical instrument having a casing made of a cyclic polyolefin resin and a gasket made of a thermoplastic elastomer composition. It has been found that the above-mentioned problems can be solved by using a polybutene rubber softener as a rubber softener, and the present invention has been completed.
That is, the gist of the present invention is as follows.

[1] A medical device having a casing made of a cyclic polyolefin-based resin and a gasket made of a thermoplastic elastomer composition, wherein the thermoplastic elastomer composition comprises the following components (A), (B) and Including component (C), the content of component (A) relative to the total amount of component (A) and component (B) is 25 to 90% by weight, and the total of component (A) and component (B) is 100% by weight A medical device containing 1 to 45 parts by weight of the component (C) with respect to parts.
Component (A): a block copolymer having at least two polymer blocks P mainly composed of a vinyl aromatic compound and at least one polymer block Q mainly composed of a conjugated diene and / or the block copolymer Hydrogenated block copolymer component (B) obtained by hydrogenating polymer: Polybutene rubber softener component (C): Polyolefin resin

[2] The medical device according to [1], wherein the component (B) has a kinematic viscosity at 100 ° C. of ¹ to 5000 mm ² s ⁻¹ .

[3] The medical device according to [1] or [2], wherein the component (A) has a weight average molecular weight (Mw) of 50,000 to 550,000.

[4] The medical instrument according to any one of [1] to [3], wherein the casing is a syringe.

  According to the present invention, in a medical device having a casing made of cyclic polyolefin resin and a gasket made of a thermoplastic elastomer composition, whitening of the casing under heating conditions such as during heat sterilization treatment, or between the casing and the gasket The problem of sticking can be solved.

  Embodiments of the present invention will be described in detail below. However, the following description is an example of the embodiments of the present invention, and the present invention is not limited to the following descriptions unless it exceeds the gist. It is not something. In addition, when using the expression “to” in the present specification, it is used as an expression including numerical values or physical property values before and after the expression.

[Thermoplastic elastomer composition]
First, a thermoplastic elastomer composition (hereinafter, may be referred to as “the thermoplastic elastomer composition of the present invention”) constituting the gasket of the medical device of the present invention will be described.

The thermoplastic elastomer composition of the present invention contains the following component (A), component (B) and component (C) in a predetermined ratio.
Component (A): a block copolymer having at least two polymer blocks P mainly composed of a vinyl aromatic compound and at least one polymer block Q mainly composed of a conjugated diene and / or the block copolymer Hydrogenated block copolymer component (B) obtained by hydrogenating polymer: Polybutene rubber softener component (C): Polyolefin resin

<Component (A)>
Component (A) in the present invention is a block copolymer having at least two polymer blocks P mainly composed of a vinyl aromatic compound and at least one polymer block Q mainly composed of a conjugated diene, and / or Alternatively, it is a hydrogenated block copolymer obtained by hydrogenating the block copolymer.
Here, the “polymer mainly composed of a vinyl aromatic compound” means a polymer obtained by polymerizing a monomer mainly composed of a vinyl aromatic compound, and the “polymer composed mainly of a conjugated diene” This means a polymer obtained by polymerizing monomers mainly composed of conjugated dienes. In the present invention, “mainly” means 50 mol% or more.

  The monomeric vinyl aromatic compound constituting the block P is not limited, but styrene derivatives such as styrene and α-methylstyrene are preferable. Of these, styrene is the main component. The block P may contain a monomer other than the vinyl aromatic compound as a raw material.

  The monomer conjugated diene constituting the block Q is not limited, but is preferably mainly composed of butadiene and / or isoprene, more preferably butadiene and isoprene. The block Q may contain a monomer other than the conjugated diene as a raw material.

The block Q may be a hydrogenated derivative obtained by hydrogenating the double bond of the block Q after polymerization of the block copolymer. The hydrogenation rate of the block Q is not limited, but is preferably 80 to 100% by weight, and more preferably 90 to 100%. By hydrogenating the block Q within the above range, the adhesive properties of the resulting thermoplastic elastomer composition are lowered and the elastic properties are increased, so that the gasket can have good properties. The same applies to the case where the block P uses a diene component as a raw material. The hydrogenation rate can be measured by ¹³ C-NMR.

When the block Q is a hydrogenated derivative and is composed mainly of butadiene, the 1,4-addition structure of butadiene in the microstructure of the block Q is preferably 20 to 100% by weight. Similarly, when the block Q is composed of isoprene, the 1,4-addition structure of isoprene in the microstructure of the block Q is preferably 60 to 100% by weight. In any case, by setting the ratio of the 1,4-addition structure within the above range, the adhesive properties of the resulting thermoplastic elastomer composition are lowered and the elastic properties are increased, so that it has good characteristics as a gasket. It can be. The ratio of 1,4-addition structure (hereinafter sometimes referred to as “1,4-microstructure ratio”) can be measured by ¹³ C-NMR.

The component (A) in the present invention is not limited as long as it has a structure having at least two polymer blocks P and at least one polymer block Q, and may be any of linear, branched, radial, etc. However, the block copolymer represented by the following formula (1) or (2) is preferable. Furthermore, the block copolymer represented by the following formula (1) or (2) is more preferably a hydrogenated block copolymer obtained by hydrogenation. When the copolymer represented by the following formula (1) or (2) is a hydrogenated block copolymer, the thermal stability is improved.
P- (Q-P) m (1)
(PQ) n (2)
(Wherein P represents the polymer block P, Q represents the polymer block Q, m represents an integer of 1 to 5, and n represents an integer of 2 to 5)
In the formula (1) or (2), m and n are preferably large in terms of lowering the order-disorder transition temperature as a rubbery polymer, but small in terms of ease of production and cost. .

  When component (A) is a hydrogenated block copolymer represented by formula (1) or (2) and block Q is composed of butadiene, 1,4-addition of butadiene in the microstructure of block Q The structure is preferably 20 to 70% by weight. Similarly, when the block Q is composed of isoprene, the 1,4-addition structure of isoprene in the microstructure of the block Q is preferably 60 to 100% by weight. In any case, by setting the 1,4-microstructure ratio in the above range, the adhesive properties of the thermoplastic elastomer composition obtained are lowered and the elastic properties are increased, so that it has good characteristics as a gasket. can do.

  Since the block copolymer and / or hydrogenated block copolymer (hereinafter collectively referred to as “(hydrogenated) block copolymer”) is excellent in rubber elasticity, it is represented by the formula (2) ( The (hydrogenated) block copolymer represented by the formula (1) is more preferable than the (hydrogenated) block copolymer, and the (hydrogenated) block copolymer represented by the formula (1) in which m is 3 or less. More preferred are polymers, (hydrogenated) block copolymers represented by formula (1) wherein m is 2 or less, (hydrogenated) blocks represented by formula (1) wherein m is 1 A copolymer is most preferred.

The weight ratio of the block P and the block Q constituting the component (A) is arbitrary, but from the viewpoint of the mechanical strength and heat-sealing strength of the thermoplastic elastomer composition of the present invention, it is preferable that the block P is large. On the other hand, it is preferable that the number of blocks P is small in terms of flexibility, profile extrusion moldability, and bleed-out suppression.
The proportion by weight of the block P in the component (A) is preferably 10% by weight or more, more preferably 15% by weight or more, still more preferably 30% by weight or more, while 60% by weight. Is preferably 50% by weight or less, more preferably 45% by weight or less.

  The method for producing component (A) in the present invention is not particularly limited as long as the above structure and physical properties can be obtained. Specifically, for example, it can be obtained by performing block polymerization in an inert solvent using a lithium catalyst or the like by the method described in Japanese Patent Publication No. 40-23798. The block copolymer may be hydrogenated (hydrogenated), for example, as described in JP-B-42-8704, JP-B-43-6636, JP-A-59-133203, and JP-A-60-79005. Can be carried out in the presence of a hydrogenation catalyst in an inert solvent. In this hydrogenation treatment, 50% or more of the olefinic double bonds in the polymer block are preferably hydrogenated, more preferably 80% or more are hydrogenated, and in the polymer block It is preferable that 25% or less of the aromatic unsaturated bond is hydrogenated.

Examples of such commercially available hydrogenated block copolymers include “KRATON (registered trademark) -G” manufactured by Kraton Polymer Co., Ltd., “Septon (registered trademark)”, “Hibler (registered trademark)” manufactured by Kuraray Co., Ltd., Asahi Kasei. Examples include “Tuftec (registered trademark)” manufactured by Co., Ltd.
Commercially available non-hydrogenated type block copolymers include “KRATON (registered trademark) -A” manufactured by Kraton Polymer, “Grabber” manufactured by Kuraray Co., Ltd., and “Tufprene” manufactured by Asahi Kasei Corporation. (Registered trademark) ".

The number average molecular weight (Mn) of the component (A) in the present invention is not particularly limited, but is preferably 30,000 or more, more preferably 50,000 or more, still more preferably 80,000 or more, while preferably 500. , 000 or less, more preferably 400,000 or less, and still more preferably 300,000 or less. It is preferable for the number average molecular weight of the component (A) to be in the above range because the moldability and heat resistance tend to be good.
Although the weight average molecular weight (Mw) of the component (A) in this invention is not specifically limited, Preferably it is 50,000 or more, More preferably, it is 80,000 or more, More preferably, it is 100,000 or more, On the other hand, Preferably it is 550 , 000 or less, more preferably 500,000 or less, and still more preferably 400,000 or less. It is preferable that the weight average molecular weight of the component (A) is in the above range because the moldability and heat resistance tend to be good.

In addition, in this invention, the weight average molecular weight (Mw) and number average molecular weight (Mn) of a component (A) are the polystyrene conversion values calculated | required by the measurement by a gel permeation chromatography (GPC), The measurement conditions are the following. It is as follows.
(Measurement condition)
Equipment: “HLC-8120GPC” manufactured by Tosoh Corporation
Column: “TSKgel Super HM-M” manufactured by Tosoh Corporation
Detector: Differential refractive index detector (RI detector / built-in)
Solvent: Chloroform Temperature: 40 ° C
Flow rate: 0.5 mL / min Injection volume: 20 μL
Concentration: 0.1% by weight
Calibration data: Monodisperse polystyrene Calibration method: Polystyrene conversion

<Component (B)>
As the softening agent for polybutene rubber of component (B), one or more kinds such as polybutene and hydrogenated polybutene can be used. In this invention, the thermoplastic elastomer which comprises a gasket contains the softening agent for polybutene type rubbers of a component (B), Therefore The cyclic polyolefin resin which comprises a housing | casing when exposed to heating conditions by sterilization etc. It is thought that the transition of the softening agent to can be suppressed and whitening of the housing can be prevented.

Polybutene rubber softener of Component (B) preferably has a kinematic viscosity at 100 ° C. is 1~5000mm ² s ^-1, more preferably those which are 100~1000mm ² s ^-1, 200~800mm ² s ^{A value} of ^-1 is particularly preferable in terms of formability. The kinematic viscosity at 100 ° C. of the polybutene rubber softener of component (B) is a value measured according to JIS K2283.

<Ingredient (C)>
Specific examples of the polyolefin resin of component (C) include polyethylene resins such as low density polyethylene homopolymer, high density polyethylene homopolymer, ethylene / α-olefin copolymer, ethylene / methacrylic acid copolymer; propylene alone Examples include polymers, polypropylene resins such as propylene / α-olefin copolymers, and those obtained by modifying these polymers with an acid anhydride to give a polar functional group. Here, in the present invention, “polyethylene resin” means a polymer obtained from a monomer mainly composed of ethylene, and “polypropylene resin” means a polymer obtained from a monomer mainly composed of propylene. means. Among the polyolefin resins listed above, the component (C) is preferably a polyethylene resin or a polypropylene resin. Among them, ethylene homopolymers and ethylene / α-olefin copolymers are preferable as polyethylene resins, and propylene homopolymers and propylene / α-olefin copolymers are preferable as propylene resins, ethylene homopolymers, Propylene homopolymer is most preferred. As the polyolefin resin, any one of the above-mentioned various polyolefin resins may be used alone, or a mixture of plural kinds may be used.

  When the polyolefin resin is a polypropylene resin or a polyethylene resin, the melt flow rate (MFR) is preferably larger in terms of moldability and smaller in terms of mechanical strength. Specifically, the MFR of the polyolefin resin is preferably 0.1 g / 10 min or more, more preferably 1 g / 10 min or more, while 50 g / 10 min or less is preferable, and 30 g / 10 minutes or less is more preferable. When the polyolefin resin is a polypropylene resin, MFR is a value measured at 230 ° C. and 2.16 kg load according to JIS K7210. When the polyolefin resin is a polyethylene resin, MFR is according to JIS K7210. The measured value is 190 ° C. and a load of 2.16 kg.

<Content ratio of components (A) to (C)>
In the thermoplastic elastomer composition of the present invention, the content of the component (A) with respect to the total amount of the component (A) and the component (B) is 25% by weight or more, preferably 30% by weight or more, more preferably 35% by weight or more. On the other hand, it is 90% by weight or less, preferably 80% by weight or less, more preferably 60% by weight or less. Further, the content of the component (C) with respect to 100 parts by weight of the total of the component (A) and the component (B) is 1 part by weight or more, preferably 2 parts by weight or more, more preferably 6 parts by weight or more, 45 parts by weight or less, preferably 40 parts by weight or less, more preferably 25 parts by weight or less.

In the sum of component (A) and component (B), if the amount of component (A) is larger than the above range and the amount of component (B) is small, the effect of imparting rubber elasticity due to the blending of the polybutene rubber softener is sufficient. On the contrary, if the component (A) is less than the above range and the component (B) is more than the above range, the moldability, the slidability (slidability) of the molded product and the like are inferior.
Moreover, it is preferable at points, such as suppression of a blocking, and a moldability, that content of the component (C) with respect to a total of 100 weight part of a component (A) and a component (B) is more than the said minimum, It is below the said upper limit. From the viewpoint of sealing properties.

<Other ingredients>
In the thermoplastic elastomer composition of the present invention, resins and additives other than the above-mentioned components (A) to (C) may be used as long as the effects of the present invention are not significantly impaired.
Specific examples of resins other than the components (A) to (C) include, for example, polyphenylene ether resins; polyamide resins such as nylon 66 and nylon 11; polyester resins such as polyethylene terephthalate and polybutylene terephthalate; Examples thereof include thermoplastic resins such as acrylic / methacrylic resins such as methyl methacrylate resins.

Examples of additives other than components (A) to (C) include various heat stabilizers, antioxidants, ultraviolet absorbers, anti-aging agents, plasticizers, light stabilizers, crystal nucleating agents, and impact modifiers. , Pigments, lubricants, antistatic agents, flame retardants, flame retardant aids, fillers, compatibilizers, tackifiers, hydrocarbon rubber softeners (except for those corresponding to component (B)). ) And the like.
These other resins, additives and the like may be used alone or in combination of two or more in any combination and ratio.

Examples of the heat stabilizer and the antioxidant include hindered phenols, phosphorus compounds, hindered amines, sulfur compounds, copper compounds, alkali metal halides, and the like.
Examples of the lubricant include silicone oil, fatty acid amide, fatty acid glyceride and the like.
Flame retardants are roughly classified into halogen-based flame retardants and non-halogen-based flame retardants, and non-halogen-based flame retardants are preferable in terms of the environment. Non-halogen flame retardants include phosphorus flame retardants, hydrated metal compounds (aluminum hydroxide and magnesium hydroxide) flame retardants, nitrogen-containing compounds (melamine and guanidine) flame retardants and inorganic compounds (borate and molybdenum) Compound) flame retardant and the like.

  Fillers are roughly classified into organic fillers and inorganic fillers. Examples of the organic filler include naturally occurring polymers such as starch, cellulose fine particles, wood flour, okara, fir husk, bran, and modified products thereof. Inorganic fillers include talc, calcium carbonate, zinc carbonate, wollastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, sodium aluminosilicate, magnesium silicate, glass balloon, carbon Examples thereof include black, zinc oxide, antimony trioxide, zeolite, hydrotalcite, metal fiber, metal whisker, ceramic whisker, potassium titanate, boron nitride, graphite, and carbon fiber.

  Even when resins and components other than the components (A) to (C) are used, the total amount of the components (A) to (C) in the thermoplastic elastomer composition of the present invention is the expression of the excellent effects of the present invention. From the viewpoint of ease of handling, it is preferably 60% by weight or more, and more preferably 80% by weight or more. The upper limit here is usually 100% by weight.

<Method for producing thermoplastic elastomer composition>
The thermoplastic elastomer composition of the present invention is produced by mixing the above-described components at a predetermined ratio, and is excellent in flexibility and moldability.

  About the manufacturing method of the thermoplastic elastomer composition of this invention, if a raw material component disperse | distributes uniformly, there will be no restriction | limiting in particular. That is, a resin composition in which each component is uniformly distributed can be obtained by mixing the above-described raw material components simultaneously or in any order.

  The thermoplastic elastomer composition of the present invention includes a state in which the above raw material components are dry blended as they are, and may be molded into a gasket, but for more uniform mixing and dispersion, These raw material components are preferably melt-mixed to form a composition. As a method of melt mixing, for example, the raw material components of the thermoplastic elastomer composition of the present invention may be mixed in an arbitrary order and then heated, or may be mixed while sequentially melting all the raw material components. Alternatively, a mixture of raw material components may be pelletized or melt-mixed at the time of molding when producing a target molded product.

  The mixing method and mixing conditions for mixing the raw material components are not particularly limited as long as the raw material components and the like are uniformly mixed. From the viewpoint of productivity, a single screw extruder or a twin screw extruder is used. A known melt-kneading method such as a continuous kneader and a batch kneader such as a mill roll, a Banbury mixer, and a pressure kneader is preferred. The temperature at the time of melt mixing may be a temperature at which at least one of the raw material components is in a molten state, but usually a temperature at which all the components used are melted is selected, and is generally in the range of 150 to 250 ° C.

  In the thermoplastic elastomer composition of the present invention, the MFR at 230 ° C. and 49 N (5 kgf) load measured according to test condition 4 of JIS K7210 is preferably large in terms of moldability, and smaller in terms of mechanical strength. preferable. Specifically, the MFR at 230 ° C. and 49 N (5 kgf) load of the thermoplastic elastomer composition is preferably 0.2 g / 10 min or more, more preferably 0.3 g / 10 min or more. , 300 g / 10 min or less is preferable, and 200 g / 10 min or less is more preferable.

[gasket]
The gasket of the medical instrument of the present invention (hereinafter sometimes referred to as “the gasket of the present invention”) can be obtained by molding the above-described thermoplastic elastomer composition of the present invention into a gasket shape. The gasket of the present invention may have any shape as long as sealing and sliding properties can be secured.

  The manufacturing method of the gasket of the present invention is not particularly limited as long as it can be formed into a shape that can exhibit sealing properties. Specific examples include stamping from injection molding, compression molding, and extrusion molding. Among these, injection molding or compression molding is preferable in view of molding cycle and mass productivity.

  The temperature of the cylinder and the die at the time of molding is preferably a high temperature from the viewpoint that appearance failure due to surface precipitation of unmelted material is unlikely to occur, and the melting point is the highest among the components contained in the thermoplastic elastomer composition More preferably, the temperature is higher than the melting point of the component, more preferably 10 ° C. or higher than the melting point of the highest melting component, and particularly preferably 20 ° C. or higher than the melting point of the highest melting component. Specifically, since the melting point of the component (A) is generally 160 to 240 ° C, it is preferably 170 ° C or higher, more preferably 190 ° C or higher, and 200 ° C or higher. Further preferred. On the other hand, in order not to cause discoloration or deterioration of physical properties due to thermal decomposition of the contained components, the temperature of the cylinder and the die during molding is preferably low. The upper limit of the cylinder and die temperature during molding is preferably 250 ° C. or less, and more preferably 240 ° C. or less. In addition, the mold temperature when performing injection molding is preferably 60 ° C. or lower, and more preferably 45 ° C. or lower.

[Case]
The housing of the medical instrument of the present invention is made of a cyclic polyolefin resin.
Cyclic polyolefin refers to a hydrogenated product of a copolymer of ethylene and a cyclic olefin monomer or a ring-opening metathesis polymer of a cyclic olefin monomer. Examples of the cyclic olefin monomer include monocyclic cycloolefins such as cyclobutene, cyclopentene, cyclooctene, and cyclododecene, and derivatives thereof having a substituent, substituted and unsubstituted bicyclic or tricyclic or more polycyclic rings having a norbornene ring. Examples thereof include olefin monomers (hereinafter sometimes referred to as “norbornene monomers”). From the viewpoints of production suitability and content suitability, a norbornene monomer is preferably used.

  Examples of the norbornene-based monomer include norbornene, norbornadiene, methylnorbornene, dimethylnorbornene, ethylnorbornene, chlorinated norbornene, chloromethylnorbornene, trimethylsilylnorbornene, phenylnorbornene, cyanonorbornene, dicyanonorbornene, methoxycarbonylnorbornene, pyridylnorbornene, and nadic. Bicyclic cycloolefins such as acid anhydrides and nadic imides; Tricyclic cycloolefins such as dicyclopentadiene, dihydrodicyclopentadiene and their alkyl, alkenyl, alkylidene, and aryl substituents; dimethanohexahydronaphthalene, dimethanooctahydro Tetracyclic cycloolefins such as naphthalene and its alkyl, alkenyl, alkylidene and aryl substituents Pentacyclic cycloolefins such as tricyclopentadiene; fin like hexacyclic cycloolefins such as hexamethylene cycloheptanone decene and the like. It is also possible to use dinorbornene, a compound in which two norbornene rings are bonded by a hydrocarbon chain or an ester group, a compound containing a norbornene ring such as an alkyl or aryl substituent thereof, and the like.

  As the copolymer of ethylene and a cyclic olefin monomer, for example, commercially available products such as “Apel (registered trademark)” manufactured by Mitsui Chemicals, Inc. and “TOPAS (registered trademark)” manufactured by TICONA can be suitably used. . Further, as the hydrogenated product of the ring-opening metathesis polymer of the norbornene-based monomer, “ZEONEX (registered trademark)”, “ZEONOR (registered trademark)” manufactured by ZEON CORPORATION, and “ARTON (registered trademark)” manufactured by JSR are available. A commercially available product such as “can be suitably used.

  As the cyclic polyolefin-based resin, a cyclic polyolefin-based resin composition in which a plurality of types of cyclic polyolefin-based resins are used in combination as long as the transparency and water vapor barrier properties are not impaired can be used. Mixtures can also be used.

  The housing of the medical instrument of the present invention can be manufactured in accordance with a conventional method by extrusion molding, injection molding, two-color molding, or the like using the above cyclic polyolefin resin.

[Medical equipment]
The medical instrument of the present invention has a casing made of the above cyclic polyolefin resin and a gasket made of a thermoplastic elastomer composition.
As long as the medical instrument of the present invention has a casing made of a cyclic polyolefin resin and the gasket of the present invention, there are no particular restrictions on the shape, purpose of use, etc., but a typical example is a syringe. The housing in the medical instrument of the present invention is preferably a syringe, and in particular, the medical instrument of the present invention is suitably applied as a prefilled syringe.

  EXAMPLES Hereinafter, although the content of this invention is demonstrated more concretely using an Example, this invention is not limited by a following example, unless the summary is exceeded. The values of various production conditions and evaluation results in the following examples have meanings as preferred values of the upper limit or lower limit in the embodiments of the present invention, and the preferred ranges are the upper limit or lower limit values described above, and It may be a range defined by a combination of values of the examples or values between the examples.

[material]
The materials used in the following examples and comparative examples are shown below.
[Component (A)]
(A-1): “Septon (registered trademark) 4077” manufactured by Kuraray Co., Ltd .: a styrene-isoprene-butadiene-styrene hydrogenated block copolymer. Styrene (block P) content: 30% by weight (measured by ¹³ C-NMR), 1,4-microstructure ratio of isoprene: 94%, 1,4-microstructure ratio of butadiene: 93%, weight average molecular weight: 381 , 000, number average molecular weight: 290,000.

[Component (B)]
(B-1) (for Examples): “Nisseki Polybutene HV-300” manufactured by JX Nippon Oil & Energy Corporation: Polybutene oil. Kinematic viscosity at 100 ° C .: 590 mm ² s ⁻¹ .
(B-1) (for comparative example): “Diana Process Oil PW-90” manufactured by Idemitsu Kosan Co., Ltd .: Paraffin-based process oil.

[Component (C)]
(C-1): “Novatec (registered trademark) PP FA3KM” manufactured by Nippon Polypro Co., Ltd .: a polypropylene homopolymer. MFR (230 ° C., 2.16 kg load): 10 g / 10 min.

[Antioxidant]
(D-1): “Irganox (registered trademark) 1010” manufactured by BASF Japan Ltd .: a hindered phenol-based antioxidant.

[Lubricant]
(E-1): “SH200-100cs” manufactured by Toray Dow Corning: Silicone oil. Kinematic viscosity (25 ° C.): 100 cSt.
(E-2): “Diamid O-200” manufactured by Nippon Kasei Co., Ltd .: Fatty acid amide.
(E-3): “Diamid L-200” manufactured by Nippon Kasei Co., Ltd .: Fatty acid amide.

[Cyclic polyolefin resin]
(F-1): “Zeonex (registered trademark) 690R” manufactured by Nippon Zeon Co., Ltd .: cycloolefin polymer. Density: 1.01 g / cm ³ , MFR (280 ° C., 2.16 kg load): 20 g / 10 min.

[Example 1, Comparative Example 1]
<Manufacture of thermoplastic elastomer composition test piece>
Based on the blending ratio (parts by weight) shown in Table 1, the temperature is raised in the range of 180 to 240 ° C. by a twin screw extruder (“TEX-30α” manufactured by Nippon Steel Works, Ltd., cylinder diameter 30 mm) and melt-kneaded. And pellets of a thermoplastic elastomer resin composition were obtained. Using this pellet, a plate of 80 mm × 120 mm × 2 mm was formed with an injection molding machine (“J-150SSII” manufactured by Nippon Steel Co., Ltd.), and a test piece having a diameter of 28 mm for gasket characteristic evaluation was punched out therefrom. The injection molding conditions were resin temperature: 180-240 ° C., injection time: 2-20 seconds, mold temperature: 20-60 ° C., cooling time: 10-40 seconds. The MFR of the obtained thermoplastic elastomer composition was 1.1 g / 10 min in Example 1 and 4.3 g / 10 min in Comparative Example 1.

<Manufacture of cyclic polyolefin resin film>
(F-1) was molded by a twin-screw extruder KZW15-45MG-NH manufactured by Technobel Co., Ltd. to obtain a single layer film having a thickness of 100 μm. The molding conditions were set to a molding temperature: 230 to 260 ° C. and a molding speed: 3 m / min. The obtained film was cut into a size of 10 cm square.

<Evaluation test>
The punched thermoplastic elastomer resin composition test piece was placed on the center of the cut-out cyclic polyolefin resin film and brought into contact with each other to obtain an evaluation sample. This was placed in an oven at 120 ° C., heated for 120 minutes with a load of 4.5 kg, removed, and air-cooled at 23 ° C. for 30 minutes. The test piece of the thermoplastic elastomer resin composition was removed from the sample for evaluation, and the change in appearance of the portion of the remaining film that was in contact with the test piece was evaluated based on the following criteria.
○: No change is observed in the film, and the thermoplastic elastomer resin composition test piece is not fixed to the cyclic polyolefin resin film.
X: Changes such as whitening and cracking are observed in the film, or the thermoplastic elastomer resin composition test piece is fixed to the cyclic polyolefin resin film.
About the test piece obtained in Example 1 and Comparative Example 1, the result evaluated by said method is shown in Table-1.

  From Table 1, the use of a polybutene rubber softener instead of a hydrocarbon rubber softener as a rubber softener enables whitening of a polyolefin polyolefin resin housing under heating conditions and a thermoplastic elastomer composition. It turns out that sticking with a product gasket can be prevented.

Claims (4)

A medical instrument having a casing made of a cyclic polyolefin-based resin and a gasket made of a thermoplastic elastomer composition, wherein the thermoplastic elastomer composition comprises the following component (A), component (B) and component (C ), The content of component (A) with respect to the total amount of component (A) and component (B) is 25 to 90% by weight, and the total amount of component (A) and component (B) is 100 parts by weight Medical device containing 1 to 45 parts by weight of component (C).
Component (A): a block copolymer having at least two polymer blocks P mainly composed of a vinyl aromatic compound and at least one polymer block Q mainly composed of a conjugated diene and / or the block copolymer Hydrogenated block copolymer component (B) obtained by hydrogenating polymer: Polybutene rubber softener component (C): Polyolefin resin The medical device of Claim ¹ whose kinematic viscosity in 100 degreeC of a component (B) is 1-5000mm < ² > s- ¹ .   The medical device according to claim 1 or 2, wherein the component (A) has a weight average molecular weight (Mw) of 50,000 to 550,000.   The medical instrument according to any one of claims 1 to 3, wherein the casing is a syringe.