JP6825510B2 - Medical instruments and thermoplastic elastomer compositions - Google Patents

Description

The present invention relates to a medical device, more particularly, a medical device having a housing made of a cyclic polyolefin resin and a sealing component made of a thermoplastic elastomer composition in contact with the housing, and the sealing component. Excellent sealing performance, heat resistance, compression set resistance, and bleeding resistance, as well as whitening of the contact part with the sealing parts of the housing and sealing performance with the housing when exposed to heating conditions such as sterilization. Regarding medical instruments that have solved the problem of sticking to parts. The present invention also relates to a thermoplastic elastomer composition suitable as a constituent material for a sealing component of such a medical device.

In recent years, plastic medical containers have been widely used as storage containers for pharmaceuticals because they are lightweight, inexpensive, less damaged by dropping, and easy to mold. In recent years, the outer cylinder that seals the tip of the syringe is filled with a drug solution or injection solution, and the opening at the other end is transported and stored in a sealed part (gasket), and then injected into the tip of the syringe. Prefilled syringes that administer chemicals and injections by attaching a needle or administration device and pushing in a gasket to slide inside the syringe are beginning to be used. Prefilled syringes are easy to operate and do not require on-site preparation of drugs because they are already filled with chemicals, which not only prevents bacterial infections, but also shortens dispensing time. Has the advantages of. For this reason, in recent medical practice, prefilling of various drugs has been desired from the viewpoint of improving treatment efficiency and preventing medical malpractice.

As the material of the syringe in the prefilled syringe, a cyclic polyolefin resin is usually used from the viewpoint of chemical resistance, heat resistance, and non-adsorption to the stored chemicals. On the other hand, it has been proposed to use a thermoplastic elastomer composition as a constituent material of the gasket.

For example, as improved slidability, stress relaxation characteristics, flow rise characteristics, and pulsation properties, Patent Document 1 describes a polymer block mainly composed of a vinyl aromatic compound and a polymer block mainly composed of a conjugated diene. A block copolymer and / or a hydrogenated block copolymer having the above, a hydrocarbon-based softener for rubber, and a polyolefin-based resin have been blended.

Japanese Unexamined Patent Publication No. 2012-197829

In the thermoplastic elastomer composition of Patent Document 1, when a gasket made of this thermoplastic elastomer composition is attached to a syringe made of a cyclic polyolefin resin and used, the gasket may stick to the syringe under the heating conditions during the sterilization process. , There is a problem that the contact part becomes white.

The present invention is a medical instrument having a housing made of a cyclic polyolefin resin and a sealing component made of a thermoplastic elastomer composition in contact with the housing, and the sealing property, heat resistance, and compression resistance permanent by the sealing component. For medical use, which has excellent strain resistance and bleed resistance, and does not have the problem of whitening the contact part of the housing with the sealing parts and sticking between the housing and the sealing parts when exposed to heating conditions such as sterilization. It is an object of the present invention to provide an instrument and a thermoplastic elastomer composition for the instrument.

As a result of diligent studies to solve the above problems, the present inventor has determined a specific block polymer A, an isobutylene polymer B, and a polypropylene resin C as the thermoplastic elastomer composition constituting the sealing component. It was found that the above-mentioned problems can be solved by using the polymer contained in the above-mentioned ratio, and the present invention has been completed.
That is, the gist of the present invention is as follows.

[1] A medical device having a housing made of a cyclic polyolefin resin and a sealing component made of a thermoplastic elastomer composition, in which the housing and the sealing component are in contact with each other. The plastic elastomer composition contains 25 to 100 parts by mass of the isobutylene polymer B and 5 to 100 parts by mass of the polypropylene-based resin C with respect to 100 parts by mass of the block polymer A. It is a hydrogenated product of a block copolymer R having two or more polymer blocks P containing a styrene unit as a constituent unit and one or more polymer blocks Q containing a conjugated diene unit as a constituent unit, and contains styrene units. The ratio is 20 to 50% by mass based on the total constituent monomer units, the polymer has a mass average molecular weight of 150,000 to 350,000, and the bending elasticity of the polypropylene-based resin C is 1,000 to 350,000. A medical device at 3,000 MPa.

[2] The medical device according to [1], wherein the isobutylene polymer B has a viscosity average molecular weight of 5,000 to 100,000.

[3] The medical device according to [1] or [2], wherein the polypropylene-based resin C is polypropylene.

[4] The medical device according to any one of [1] to [3], wherein the conjugated diene unit, which is a constituent unit of the polymer block Q, is an isoprene unit.

[5] The proportion of 3,4-bonds in the isoprene unit in the polymer block Q is 30 to 60 mol%, and the proportion of 1,4-bonds is 20 to 50 mol%, according to [4]. Medical equipment.

[6] The thermoplastic elastomer composition further contains 10 to 70 parts by mass of talc D and / or 0.1 to 20 parts by mass of silicone oil E with respect to 100 parts by mass of the block polymer A. The medical device according to any one of [1] to [5].

[7] The medical device according to [6], wherein the thermoplastic elastomer composition contains silicone oil E, and the kinematic viscosity of silicone oil E at 25 ° C. is 50 to 2,000 cSt.

[8] A thermoplastic elastomer composition containing 25 to 100 parts by mass of isobutylene polymer B and 5 to 100 parts by mass of polypropylene-based resin C with respect to 100 parts by mass of block polymer A. The polymer A is a hydrogenated product of the block copolymer R having two or more polymer blocks P containing a styrene unit as a constituent unit and one or more polymer blocks Q containing a conjugated diene unit as a constituent unit. , The content ratio of the styrene unit is 20 to 50% by mass based on the total constituent monomer units, the polymer has a mass average molecular weight of 150,000 to 350,000, and the bending elasticity of the polypropylene-based resin C. A thermoplastic elastomer composition having a value of 1,000 to 3,000 MPa.

[9] The thermoplastic elastomer composition according to [8], wherein the isobutylene polymer B has a viscosity average molecular weight of 5,000 to 100,000.

[10] The thermoplastic elastomer composition according to [8] or [9], wherein the polypropylene-based resin C is polypropylene.

[11] The thermoplastic elastomer composition according to any one of [8] to [10], wherein the conjugated diene unit, which is a constituent unit of the polymer block Q, is an isoprene unit.

[12] The proportion of 3,4-bonds in the isoprene unit in the polymer block Q is 30 to 60 mol%, and the proportion of 1,4-bonds is 20 to 50 mol%, according to [11]. Thermoplastic elastomer composition.

[13] Further, [8] to [12], which contain 10 to 70 parts by mass of talc D and / or 0.1 to 20 parts by mass of silicone oil E with respect to 100 parts by mass of the block polymer A. The thermoplastic elastomer composition according to any one.

[14] The thermoplastic elastomer composition according to [13], which contains silicone oil E and has a kinematic viscosity of silicone oil E at 25 ° C. of 50 to 2,000 cSt.

[15] The thermoplastic elastomer composition according to any one of [8] to [14], which is a thermoplastic elastomer composition for molding sealable parts of medical instruments.

According to the present invention, in a medical device having a casing made of a cyclic polyolefin resin and a sealing component made of a thermoplastic elastomer composition, the sealing property, heat resistance, compression permanent strain resistance, and bleed resistance of the sealing component It is possible to solve the problems of whitening of the cyclic polyolefin resin housing and sticking between the housing and the sealing component under heating conditions such as heat sterilization.

The embodiments of the present invention will be described in detail below, but the description described below is an example of the embodiments of the present invention, and the present invention is limited to the following description as long as the gist thereof is not exceeded. It's not something. In addition, when the expression "-" is used in this specification, it shall be used as an expression including numerical values or physical property values before and after the expression.

[Thermoplastic Elastomer Composition]
First, the thermoplastic elastomer composition of the present invention constituting the sealing component of the medical device of the present invention will be described.

The thermoplastic elastomer composition of the present invention contains 25 to 100 parts by mass of isobutylene polymer B and 5 to 100 parts by mass of polypropylene-based resin C with respect to 100 parts by mass of block polymer A.
The block polymer A according to the present invention is a block copolymer R having two or more polymer blocks P containing a styrene unit as a constituent unit and one or more polymer blocks Q containing a conjugated diene unit as a constituent unit. It is a hydrogenated polymer having a styrene unit content of 20 to 50% by mass based on all constituent monomer units and a mass average molecular weight of 150,000 to 350,000.
The polypropylene-based resin C is a polypropylene-based resin having a flexural modulus of 1,000 to 3,000 MPa.

<Working mechanism>
A hydrogenated compound of block copolymer R used in the present invention, which has two or more polymer blocks P containing a styrene unit as a constituent unit and one or more polymer blocks Q containing a conjugated diene unit as a constituent unit. The block polymer A having a styrene unit content of 20 to 50% by mass and a mass average molecular weight of 150,000 to 350,000 based on the total constituent monomer units has heat resistance of the composition and at high temperature. It is an important component for improving the compression resistance and permanent strain resistance of the polymer.
By mixing a predetermined amount of isobutylene polymer B with such a block polymer A, the moldability of the composition can be improved and the sealing property can be improved.
Further, by mixing a predetermined amount of polypropylene resin C having a flexural modulus of 1,000 to 3,000 MPa, the balance between the moldability of the composition, the heat resistance of the obtained molded product and the sealing property is improved. can do.
Further, the essential component of the thermoplastic elastomer composition of the present invention does not contain an alicyclic structure, and there is no problem of sticking to a cyclic polyolefin resin.
Therefore, according to the present invention, the sealing property of the sealing component is excellent in sealing property, heat resistance, compression permanent strain resistance, and bleeding resistance, and the housing is exposed to heating conditions by sterilization or the like. It is possible to provide a medical device that does not have a problem of whitening or sticking between a housing and a sealing component.

<Block polymer A>
The block polymer A (hereinafter, may be referred to as “component A”) contained in the thermoplastic elastomer composition of the present invention contains two or more polymer blocks P containing a styrene unit as a constituent unit, and a constituent unit. It is a hydrogenated product of the block copolymer R having one or more polymer blocks Q containing the conjugated diene unit, and the content ratio of the styrene unit is 20 to 50% by mass based on the total constituent monomer units. It is a polymer having a mass average molecular weight of 150,000 to 350,000.

The polymer block P of the block copolymer R before hydrogenation, which constitutes the component A, contains a styrene unit as a constituent unit, and is heavy from the viewpoint of heat resistance and compression permanent strain resistance of the obtained molded product. It is preferable that the coalesced block P is mainly composed of styrene units.
On the other hand, the polymer block Q contains a conjugated diene unit as a constituent unit, and from the viewpoint of compatibility with the isobutylene polymer B, it is preferable to mainly use the conjugated diene unit, and in particular, isoprene among the conjugated diene units. It is preferable to use the unit as the main component.

Here, the "polymer block mainly composed of a styrene unit" means a polymer obtained by polymerizing a monomer mainly composed of styrene, and the "polymer block mainly composed of a conjugated diene unit" means a conjugated diene. It means a polymer of a monomer mainly composed of. Further, here, "mainly" means that the content ratio is 50% by mass or more.

Examples of the monomer other than styrene constituting the polymer block P include styrene derivatives such as α-methylstyrene and other vinyl aromatic compounds. The polymer block P may contain a monomer unit other than the vinyl aromatic compound. For example, the diene unit exemplified below may be contained as the diene compound constituting the polymer block Q. The content ratio of the styrene unit contained in the polymer block P is preferably 70% by mass or more, particularly 90 to 100% by mass, from the viewpoint of heat resistance and compression set resistance of the obtained molded product.

Examples of the conjugated diene unit, which is a structural unit constituting the polymer block Q, include an isoprene unit and a butadiene unit. Among these, the isoprene unit is preferable. When the isoprene unit is contained as the conjugated diene unit contained in the polymer block Q, the content ratio of the isoprene unit is 60% by mass or more, particularly 80 to 100% by mass from the viewpoint of compatibility with the isobutylene polymer B. Is preferable.

When the isoprene unit is contained as the conjugated diene unit contained in the polymer block Q of the block copolymer R, the ratio of 3,4-bonds in the isoprene unit is preferably 30 to 60 mol%. When the ratio of 3,4-bonds in the isoprene unit is 30 mol% or more, the flexibility of the obtained molded product is improved and the sealing property is good, and when it is 60 mol% or less, the isobutylene polymer B and The compatibility of the above is good, which is preferable. A more preferred proportion of 3,4-bonds is 40-59 mol%, particularly preferably 45-58 mol%.

When the isoprene unit is contained as the conjugated diene unit contained in the polymer block Q of the block copolymer R, the ratio of 1,4-bonds in the isoprene unit is preferably 20 to 50 mol%. When the ratio of 1,4-bonds in the isoprene unit is 20 mol% or more, the elastic property of the obtained molded product is improved, and when it is 50 mol% or less, the flexibility of the obtained molded product is good, which is preferable. .. A more preferred proportion of 1,4-bonds is 25-48 mol%, particularly preferably 30-45 mol%.

The polymer block Q containing an isoprene unit as a conjugated diene unit has a particularly 3,4-bond ratio of 45 to 58 mol%, a 1,4-bond ratio of 30 to 45 mol%, and a 1,2-bond. The ratio of 3 to 15 mol% is preferable.

Here, when the isoprene unit is included as the conjugated diene unit contained in the polymer block Q, the ratio of 3,4-bond, 1,4-bond, and 1,2-bond in the isoprene unit is determined by ¹³ C-NMR. Can be measured.

The block copolymer R 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 linear, branched, radial or the like. Although it may be used, a block copolymer represented by the following formula (1) or (2) is preferable. When the component A is a hydrogenated block copolymer R represented by the following formula (1) or (2), the thermal stability is improved.
P- (QP) m (1)
(PQ) n (2)
(In the formula, 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 should be large in terms of lowering the order-disorder transition temperature as a rubber polymer, but should be small in terms of ease of production and cost. ..

Since the component A is excellent in rubber elasticity, the hydrogenated block copolymer represented by the formula (1) is preferable to the hydrogenated block copolymer represented by the above formula (2). , The hydrogenated product of the block copolymer represented by the formula (1) in which m is 3 or less is more preferable, and the hydrogenated product of the block copolymer represented by the formula (1) in which m is 2 or less is more preferable. More preferred.

The component A is most preferably a hydrogenated styrene-isoprene-styrene block copolymer.

The mass ratio of the polymer block P and the polymer block Q constituting the block copolymer R is arbitrary, but the component A is considered from the viewpoint of the mechanical strength and the heat fusion strength of the thermoplastic elastomer composition of the present invention. It is preferable that the content of the styrene unit in the styrene unit is high, while the content of the styrene unit is low in terms of flexibility, shape extrusion moldability, and bleed-out suppression of the thermoplastic elastomer composition.
The content ratio of the styrene unit in the component A of the block copolymer R is 20 to 50% by mass, preferably 25 to 45% by mass, and more preferably 28 to 40% by mass based on the total constituent monomer units. As such, by containing the polymer block P and the polymer block Q, the above-mentioned characteristic balance is excellent.

The hydrogenation rate of block copolymer R when hydrogenating block copolymer R to obtain block polymer A is not limited, but the hydrogenation rate of polymer block Q is preferably 80 to 100% by mass, preferably 90 to 90 to 100% by mass. 100% by mass is preferable. By hydrogenating the polymer block Q in the above range, the adhesive property of the obtained composition is lowered and the elastic property is increased, so that good properties can be obtained as a sealing component. The same applies to the case where the polymer block P uses a diene component as a raw material. Here, the hydrogenation rate can be measured by ¹³ C-NMR.

The method for producing the block copolymer R in the present invention may be any method as long as the above-mentioned structure and physical properties can be obtained, and is not particularly limited. 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. Further, hydrogenation (hydrogenation) of the block copolymer R is carried out, for example, in JP-A-42-8704, JP-A-43-6636, JP-A-59-133203 and JP-A-60-79005. It can be carried out in the presence of a hydrogenation catalyst in an inert solvent by the method described in the publication.

The mass average molecular weight (Mw) of the component A in the present invention is 150,000 or more, preferably 180,000 or more, more preferably 200,000 or more, and 350,000 or less, preferably 330,000 or less, more preferably. Is 310,000 or less. When the mass average molecular weight of component A is within the above range, moldability and heat resistance are good, which is desirable.

In the present invention, the mass average molecular weight (Mw) of the component A is measured by GPC under the following measurement conditions.
(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)
Solution: Chloroform Temperature: 40 ° C
Flow rate: 0.5 ml / min Injection volume: 20 μL
Concentration: 0.1 wt%
Calibration data: Monodisperse polystyrene Calibration method: Polystyrene conversion Calibration curve Approximation formula: Third-order peak separation software: "DBFinder SP" manufactured by Tosoh Corporation
Peak separation method: Gauss-Newton method

Examples of commercially available products of component A, which is such a hydrogenated block copolymer, include "Septon" and "Hybler" manufactured by Kuraray Co., Ltd.

As the component A, only one type may be used, or two or more types having different physical properties such as triblock composition and mass average molecular weight (Mw) may be used in combination.

<Isobutylene polymer B>
The isobutylene polymer B (hereinafter, may be referred to as “component B”) contained in the thermoplastic elastomer composition of the present invention is a homopolymer of isobutylene, that is, polyisobutylene.

Isobutylene is cationically polymerizable, and isobutylene polymer B is, for example, the method reported by Kennedy et al. (J. Polym. Sci., Part A; Polym. Chem. 29, 427-435 (1991)). ) Can be manufactured.

The viscosity average molecular weight of the isobutylene polymer B is not particularly limited, but is preferably 5,000 to 100,000, particularly preferably 10,000 to 90,000, and particularly 20,000 to 20,000, from the viewpoint of adhesiveness and strength. 80,000 is preferable. If the mass average molecular weight is less than 5,000, the strength is weakened and the bleed resistance of the molded product is deteriorated. On the contrary, if it exceeds 100,000, the melt viscosity becomes high and it may not be possible to mix uniformly with other components.

As the isobutylene polymer, many products usually on the market correspond to this, and specifically, Exxon Vistanex (LM-MS, MH, H or MML-80, 100, 120, 140, etc.), new Nippon Oil Tetrax (3T, 4T, 5T, 6T, etc.), High Mall (4H, 5H, 6H, etc.), and BASF Opanol (B10, B12, B15, B50, B80, B100, B120, B150, B220, etc.) ) Etc. can be exemplified.

Only one type of isobutylene polymer B may be used, or two or more types having different viscosity average molecular weights may be used in combination.

The thermoplastic elastomer composition of the present invention contains 25 to 100 parts by mass of the isobutylene polymer B of the B component with respect to 100 parts by mass of the block polymer A of the A component. If the content of the B component in the thermoplastic elastomer composition is less than the above lower limit, each component cannot be kneaded in the production of the thermoplastic elastomer composition, and it is difficult to produce the thermoplastic elastomer composition. , The fluidity at the time of molding is deteriorated, and the appearance of the molded product is deteriorated. If the above upper limit is exceeded, the bleed resistance of the molded product is deteriorated. From these viewpoints, the thermoplastic elastomer composition of the present invention preferably contains 30 to 90 parts by mass of the B component with respect to 100 parts by mass of the A component, and more preferably 35 to 80 parts by mass.

<Polypropylene resin C>
The polypropylene-based resin C (hereinafter, may be referred to as “C component”) contained in the thermoplastic elastomer composition of the present invention is a polypropylene-based resin having a flexural modulus of 1,000 to 3,000 MPa.

The polypropylene-based resin is a polyolefin resin in which the content of propylene units with respect to all monomer units is more than 50% by mass.

The type of polypropylene-based resin is not particularly limited, and any of propylene homopolymer, propylene random copolymer, propylene block copolymer and the like can be used.

When the polypropylene-based resin is a propylene copolymer, the monomers copolymerizing with propylene include ethylene, 1-butene, 2-methylpropylene, 1-pentene, 3-methyl-1-butene, 1-hexene, and the like. One or more types such as 4-methyl-1-pentene and 1-octene can be exemplified.

The content of the propylene unit in the polypropylene-based resin is preferably 60% by mass or more, more preferably 75% by mass or more, and further preferably 90% by mass or more. When the content of the propylene unit is at least the above lower limit value, the heat resistance and the rigidity tend to be good. From the viewpoint of heat resistance and compression set resistance of the molded product, polypropylene (propylene homopolymer) is preferably used as the polypropylene-based resin of component B. The content of propylene units in the polypropylene resin can be determined by infrared spectroscopy.

The flexural modulus of the polypropylene-based resin C is 1,000 MPa or more, preferably 1,100 MPa or more, and more preferably 1,200 MPa or more, from the viewpoint of the sealing property and needle holding property of the obtained sealing component. Further, from the viewpoint of the sealing property of the obtained sealing component, it is 3,000 MPa or less, preferably 2,500 MPa or less, and more preferably 2,000 MPa or less. That is, the flexural modulus of the polypropylene-based resin C as the component C is 1,000 to 3,000 MPa, preferably 1,100 to 2,500 MPa, and more preferably 1,200 to 2,000 MPa.

Here, the flexural modulus of the polypropylene-based resin C is a value measured in accordance with JIS K7171.

Further, the MFR of the polypropylene-based resin C of the C component measured under the conditions of a measurement temperature of 230 ° C. and a measurement load of 21.2 N according to JIS K7210 is preferably 0.1 to 100 g / 10 minutes. It is more preferably 5 to 85 g / 10 minutes, and particularly preferably 1 to 70 g / 10 minutes. When the MFR of the polypropylene-based resin C of the C component is at least the above lower limit, it is preferable from the viewpoint of molding fluidity, and when it is at least the above upper limit, it is preferable from the viewpoint of compression permanent strain resistance of the molded product and the appearance of the molded product.

The thermoplastic elastomer composition of the present invention contains 5 to 100 parts by mass of the polypropylene-based resin C of the C component with respect to 100 parts by mass of the block polymer A of the A component. If the content of the C component in the thermoplastic elastomer composition is less than the above lower limit, the heat resistance of the molded product deteriorates, and the fluidity of the composition deteriorates, so that the appearance of the molded product deteriorates. If the above upper limit is exceeded, the flexibility of the molded product will be lost and it will not have sufficient sealing properties. From these viewpoints, the thermoplastic elastomer composition of the present invention preferably contains 5 to 80 parts by mass, more preferably 10 to 60 parts by mass of the C component with respect to 100 parts by mass of the A component.

<Talc D>
The thermoplastic elastomer composition of the present invention may further contain talc D (hereinafter, may be referred to as “D component”), and by containing talc D, the surface of the molded product is appropriately roughened. It is possible to obtain the effects of improving moldability and reducing adhesion of sealable parts with cyclic polyolefin resin.
Preferred talc D has an average particle size of 20 μm or less, preferably 1 to 15 μm.

The above talc D can be produced, for example, by crushing rough talc with an impact type crusher or a micro type crusher, further pulverizing with a micron mill or a jet type crusher, and then classifying and adjusting with a cyclone or a micron separator. it can.

Here, the measurement of the average particle size of Tarku D is a value measured using a laser light scattering type particle size distribution meter, and as such a measuring device, for example, the LA-500 type manufactured by HORIBA, Ltd. has excellent measurement accuracy. It is desirable because it is.

Only one type of talc D may be used, or two or more types having different average particle diameters may be used in combination.

When the thermoplastic elastomer composition of the present invention contains talc D as a component D, it is preferable that the thermoplastic elastomer composition contains 10 to 70 parts by mass of talc D as a component D with respect to 100 parts by mass of the block polymer A. When the content of the D component in the thermoplastic elastomer composition is at least the above lower limit, it is highly effective in improving the moldability and reducing the adhesion of the sealing component to the cyclic polyolefin resin. If it is less than the above upper limit, the fluidity of the composition becomes good. From these viewpoints, the thermoplastic elastomer composition of the present invention preferably contains 15 to 60 parts by mass of the D component with respect to 100 parts by mass of the A component, and particularly preferably contains 20 to 55 parts by mass. ..

<Silicone oil E>
The thermoplastic elastomer composition of the present invention may further contain silicone oil E (hereinafter, may be referred to as “component E”), and by containing silicone oil E, releasability during molding is achieved. Can be improved.

As the silicone oil E of the E component, a silicone oil having a kinematic viscosity at 25 ° C. of 50 to 2,000 cSt is preferable. Here, the kinematic viscosity of silicone oil E at 25 ° C. can be measured by JIS Z8803.

When the kinematic viscosity of the silicone oil E of the component E at 25 ° C. is less than 50 cSt, the silicone oil bleeds on the surface of the obtained sealing component, and when used as a sealing component of a medical device, the content is silicone. There is a concern that oil may get mixed in. Further, when the kinematic viscosity of the silicone oil E of the component E at 25 ° C. is larger than 2,000 cSt, the effect of improving the releasability at the time of molding becomes low. In order to make these effects better, the kinematic viscosity of the E component at 25 ° C. is more preferably 60 cSt or more, further preferably 70 cSt or more, and more preferably 1,600 cSt or less. More preferably, it is 1,200 cSt or less, and particularly preferably 800 cSt or less.

As the silicone oil E of the E component, a linear silicone represented by the following formula (3) can be preferably used.

In the above formula (3), R independently represents an organic functional group or a hydroxyl group that does not contain a functional group involved in the hydrosilylation addition reaction such as an alkenyl group and / or a SiH group, and even if each R is the same. It may be different. x represents an integer of 10 to 2000. R preferably independently represents a monovalent hydrocarbon group or a hydroxyl group, more preferably an alkyl group or an aryl group, and further preferably a methyl group, an ethyl group or a phenyl group.

The linear silicone represented by the formula (3) is a polydiorganosiloxane having both ends sealed with a triorganosilyl group, and is a polydialkylsiloxane, polydiarylsiloxane, polyalkylarylsiloxane, or a copolymer thereof. Is more preferable, polydimethylsiloxane or polymethylphenylsiloxane is further preferable, and polydimethylsiloxane in which R is all methyl groups is particularly preferable.

Examples of polydimethylsiloxane include SH200 (manufactured by Toray Dow Corning), KF-96, KF-96H, KF-965, KF-968 (manufactured by Shinetsu Silicone), and TSF451 (manufactured by Momentive Performance Materials Japan). ), AK, AKF, AKC (manufactured by Asahi Kasei Wacker Silicone Co., Ltd.) and the like are available as commercial products. As polymethylphenylsiloxane, SH510, SH550, SH710 (manufactured by Toray Dow Corning), KF-50, KF-53, KF-54 (manufactured by Shinetsu Silicone), TSF431, TSF433, TSF4300 (momentive performance). -Materials), AR (Asahi Kasei Wacker Silicone), etc. are available as commercial products.

Only one type of silicone oil E may be used, or two or more types having different kinematic viscosities and R in the formula (3) may be used in combination.

When the thermoplastic elastomer composition of the present invention contains silicone oil E as an E component, it is preferable to contain 0.1 to 20 parts by mass of silicone oil E with respect to 100 parts by mass of the block polymer A. When the content of the E component in the thermoplastic elastomer composition is at least the above lower limit, a sufficient effect is obtained for improving the releasability at the time of molding, and when it is less than the above lower limit, the appearance of the molded product is deteriorated due to bleed-out and the pharmaceutical product. Mixing into the inside is suppressed. From these viewpoints, the thermoplastic elastomer composition of the present invention preferably contains 0.5 to 18 parts by mass of the E component with respect to 100 parts by mass of the A component, and particularly preferably contains 1 to 15 parts by mass. preferable.

<Other ingredients>
The thermoplastic elastomer composition of the present invention contains components other than the above-mentioned components A to E, for example, resins other than the components A to C and additives other than the components D and E, as long as the object of the present invention is not impaired. It may be a thing.

Specific examples of the resin other than the components A and B include polyphenylene ether-based resin; polyamide-based resin such as nylon 66 and nylon 11, polyester-based resin such as polyethylene terephthalate and polybutylene terephthalate; polymethylmethacrylate-based resin. Thermoplastic resins such as acrylic / methacrylic resins such as resins; crosslinked products such as isobutylene polymers can be mentioned.

In addition, as other additives, various heat stabilizers, antioxidants, ultraviolet absorbers, antioxidants, plasticizers, light stabilizers, crystal nucleating agents, impact improvers, pigments, lubricants, antistatic agents, etc. , Flame retardant, flame retardant aid, filler, compatibilizer, tackifier, hydrocarbon softener for rubber and the like.
As for these other resins, additives and the like, only one type may be used, or two or more types may be used in combination in any combination and ratio.

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

Fillers are roughly classified into organic fillers and inorganic fillers. Examples of the organic filler include naturally-derived polymers such as starch, cellulose fine particles, wood flour, bean curd refuse, rice husks, and bran, and modified products thereof. Inorganic fillers include calcium carbonate, zinc carbonate, wallastonite, silica, alumina, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminate, sodium aluminate, magnesium silicate, glass balloon, carbon black, etc. Examples thereof include zinc oxide, antimony trioxide, zeolite, hydrotalcite, metal fiber, metal whisker, ceramic whisker, potassium titanate, boron nitride, graphite, carbon fiber and the like.

Even when resins and additives other than the components A to E are used, the total amount of the components A to E in the thermoplastic elastomer composition of the present invention is determined from the viewpoint of ease of exhibiting the excellent effects of the present invention. , 60% by mass or more, and more preferably 80% by mass or more. The upper limit here is usually 100% by mass.

<Manufacturing method of thermoplastic elastomer composition>
The thermoplastic elastomer composition of the present invention is produced by mixing the above-mentioned components in a predetermined ratio, and is excellent in heat resistance, compression set resistance, and bleed resistance.

The method for producing the thermoplastic elastomer composition of the present invention is not particularly limited as long as the raw material components are uniformly dispersed. That is, by mixing the above-mentioned raw material components and the like at the same time or in an arbitrary order, a resin composition in which each component is uniformly distributed can be obtained.

The thermoplastic elastomer composition of the present invention also includes a state in which each of the above-mentioned raw material components is dry-blended as it is, and may be formed as a sealing component by molding the same, but for more uniform mixing and dispersion. , It is preferable that the raw material components such as the above-mentioned components A to C are melt-mixed to prepare a composition. As a method of melt-mixing, for example, each raw material component of the thermoplastic elastomer composition of the present invention may be mixed in an arbitrary order and then heated, or all the raw material components may be mixed while being sequentially melted, or each of them may be mixed. The mixture of the raw material components may be pelletized or melt-mixed at the time of molding when producing the target molded product.

The mixing method and mixing conditions when mixing each of the above-mentioned raw material components are not particularly limited as long as each raw material component is uniformly mixed, but from the viewpoint of productivity, a single-screw extruder or a twin-screw extruder Such a continuous kneader and a known melt kneading method such as a mill roll, a Banbury mixer, a batch type kneader such as a pressure kneader, etc. are preferable. 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 a temperature at which all the components to be used are melted is usually selected, and is generally in the range of 150 to 250 ° C.

[Seal parts]
The sealing component of the medical device of the present invention (hereinafter, may be referred to as "sealing component of the present invention") is formed by molding the above-mentioned thermoplastic elastomer composition of the present invention into the shape of the sealing component. Can be obtained by The sealing component of the present invention may have any shape as long as the sealing property and slidability can be ensured.

The method for producing a sealing component of the present invention is not particularly limited as long as it can be molded into a shape capable of exhibiting sealing properties. Specific examples thereof include injection molding, compression molding, punch molding from extrusion molding, and among these, injection molding or compression molding is preferable in consideration of the molding cycle and mass productivity.

The temperature of the cylinder and die during molding is preferably high in that appearance defects due to surface precipitation of unmelted material are unlikely to occur, and the melting point is the highest among the components contained in the thermoplastic elastomer composition. The temperature is more preferably higher than the melting point of the component, further preferably 10 ° C. or higher than the melting point of the component having the highest melting point, and particularly preferably 20 ° C. or higher higher than the melting point of the component having the highest melting point. 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 even more preferably 200 ° C. or higher. .. On the other hand, in order not to cause discoloration or deterioration of physical properties due to thermal decomposition of the contained components, it is preferable that the temperature of the cylinder and the die at the time of molding is low. The upper limit of the cylinder and die temperature at the time of molding is preferably 250 ° C. or lower, and more preferably 240 ° C. or lower. The mold temperature for injection molding is preferably 60 ° C. or lower, more preferably 45 ° C. or lower.

[Case]
The housing of the medical device of the present invention is made of a cyclic polyolefin resin.
The cyclic polyolefin refers to a copolymer of ethylene and a cyclic olefin monomer, or a hydrogenated additive of a ring-opening metathesis polymer of a cyclic olefin monomer. Cyclic olefin monomers include monocyclic cycloolefins such as cyclobutene, cyclopentene, cyclooctene, and cyclododecene and their derivatives having substituents, and substituted and unsubstituted bicyclic or tricyclic or more polycyclic cyclics having a norbornene ring. Examples thereof include olefin monomers (hereinafter, may be referred to as “norbornene-based monomers”). From the viewpoint of production suitability and content suitability, norbornene-based monomers are particularly preferably used.

Examples of the norbornene-based monomer include norbornene, norbornene, methylnorbornene, dimethylnorbornene, ethylnorbornene, chlorinated norbornene, chloromethylnorbornene, trimethylsilylnorbornene, phenylnorbornene, cyanonorbornene, dicyanonorbornene, methoxycarbonylnorbornene, pyridylnorbornene, and nadic. Bicyclic cycloolefins such as acid anhydrides and imides of nadic acid; tricyclic cycloolefins such as dicyclopentadiene and dihydrodicyclopentadiene and their alkyl, alkenyl, alkylidene and aryl substituents; dimethanohexahydronaphthalene and dimethanooctahydro Tetracyclic cycloolefins such as naphthalene and its alkyl, alkenyl, alkylidene, and aryl substituents; pentacyclic cycloolefins such as tricyclopentadiene; and hexacyclic cycloolefins such as hexacycloheptadecene can be mentioned. Further, 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, or the like.

As the copolymer of ethylene and cyclic olefin monomer, commercially available products such as "Appel (registered trademark)" manufactured by Mitsui Chemicals, Inc. and "TOPAS (registered trademark)" manufactured by TICONA can be preferably used. .. As hydrogenated additives for the ring-opening metathesis polymer of the above-mentioned norbornene-based monomer, "Zeonex (registered trademark)" and "Zeonoa (registered trademark)" manufactured by Nippon Zeon Co., Ltd. and "Arton (registered trademark)" manufactured by JSR Corporation. A commercially available product such as "" can be preferably used.

As the cyclic polyolefin resin, a cyclic polyolefin resin composition in which a plurality of types of cyclic polyolefin resins are used in combination can be used as long as the transparency and the water vapor barrier property are not impaired, and the cyclic polyolefin resin can also be used with polyethylene or a styrene elastomer. Mixtures can also be used.

The housing of the medical device of the present invention can be manufactured according to a conventional method by extrusion molding, injection molding, two-color molding or the like using the cyclic polyolefin resin as described above.

[Medical equipment]
The medical device of the present invention has a housing made of the cyclic polyolefin resin as described above and a sealing component made of the thermoplastic elastomer composition of the present invention.
The medical device of the present invention is not particularly limited in shape, purpose of use, etc. as long as it has a housing made of a cyclic polyolefin resin and a sealing component of the present invention in contact with the housing. Examples thereof include a syringe, and the housing of the medical instrument of the present invention is preferably a syringe, and the sealing component is a gasket. In particular, the medical instrument of the present invention is preferably applied as a prefilled syringe.

Hereinafter, the content of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded. The values of various production conditions and evaluation results in the following examples have meanings as preferable values of the upper limit or the lower limit in the embodiment of the present invention, and the preferable ranges are the above-mentioned upper limit or lower limit values and the following. It may be in the range specified by the value of Examples or the combination of the values of Examples.

[material]
The materials used in the following examples and comparative examples are shown below.

[Block polymer A]
A-1: Hybler 7135 (manufactured by Kuraray)
Hydrogenated styrene-isoprene-styrene block copolymer
Hydrogenation rate of isoprene: 100% by mass
Mass average molecular weight: 280,000
Styrene unit content: 33% by mass
Percentage of 1,2-bonds in isoprene units: 6 mol%
Percentage of 1,4-bonds in isoprene units: 41 mol%
Percentage of 3,4-bonds in isoprene units: 54 mol%

[Isobutylene polymer B]
B-1: High Mall 4H (manufactured by JX Nikko Nisseki Energy Co., Ltd.)
Isobutylene homopolymer
Viscosity average molecular weight: 40,000
b-1: Shibster 103T (manufactured by Kaneka Corporation)
Styrene-isobutylene-styrene block copolymer
Mass average molecular weight: 118,000
Isobutylene unit content ratio: 70% by mass
b-2: Toughmer A4050S (manufactured by Mitsui Chemicals, Inc.)
Ethylene-butene copolymer
Mass average molecular weight: 80,000
Ethylene unit content: 74% by mass
Butene unit content: 26% by mass

[Polypropylene resin C]
C-1: Novatec PP FA3KM (manufactured by Japan Polypropylene Corporation)
polypropylene
Flexural modulus: 1,500 MPa (JIS K7171)
MFR: 10g / 10 minutes
(Measurement conditions: 230 ° C., load 21.2N (JIS K7210))

[Talc D]
D-1: Micro Ace P-3 (manufactured by Japan Talc)
Average particle size: 8.0 μm

[Silicone oil E]
E-1: SH200-100CS (manufactured by Toray Dow Corning)
Polydimethylsiloxane
Kinematic viscosity (25 ° C): 100 cSt
E-2: SH200-1000CS (manufactured by Toray Dow Corning)
Polydimethylsiloxane
Kinematic viscosity (25 ° C): 1000 cSt

<Cyclic polyolefin resin>
Cycloolefin polymer (trade name: Zeonex (registered trademark) 690R, manufactured by Zeon Corporation, density = 1.01 g / cm ³ , MFR (280 ° C, 2.12 N load) = 20 g / 10 minutes)

[Examples 1 and 2, Comparative Examples 1 to 4]
<Manufacturing of Thermoplastic Elastomer Composition Test Piece>
The components shown in Table 1 are blended so as to have the blending ratio (parts by mass) shown in Table 1, and melt-kneaded at 200 ° C. for 5 minutes using a thermoplastic mill (manufactured by Toyo Seiki Seisakusho), and heated. A thermoplastic elastomer resin composition was obtained. Next, the obtained composition was compression molded at 200 ° C. to obtain a plate having a thickness of 2 mm.

<Manufacturing of cyclic polyolefin resin film>
A cyclic polyolefin resin 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 at a molding temperature of 230 to 260 ° C. and a molding speed of 3 m / min. The obtained film was cut into a size of 10 cm square.

The following evaluations were performed using the produced thermoplastic elastomer composition plate and cyclic polyolefin resin film, and the results are shown in Table-1.

<Mechanical evaluation: A hardness>
The measurement was carried out according to JIS K6253 using a plate of a thermoplastic elastomer composition. In order to preferably use the thermoplastic elastomer resin composition as a sealing component, the A hardness of the thermoplastic elastomer composition is preferably 40 or more and 75 or less.

<Mechanical evaluation: compression set
The measurement was carried out according to JIS K6262 using a plate of a thermoplastic elastomer composition. In order to preferably use the thermoplastic elastomer resin composition as a sealing component, it is preferable that the compression set at 120 ° C. × 22 hr (25% compression) is 80% or less.

<Evaluation of contact between the housing and sealing parts>
A test piece having a diameter of 28 mm for contact evaluation was punched out from the prepared plate of the thermoplastic elastomer composition. A test piece of the punched thermoplastic elastomer resin composition was placed on the central portion of the cut out cyclic polyolefin resin film and brought into contact with each other to prepare a sample for evaluation. This is placed in an oven at 120 ° C., heated for 120 minutes with a load of 4.5 kg applied, and then air-cooled at 23 ° C. for 30 minutes after removing the load, and then a stickiness test and a whitening confirmation test are performed by the following measurement methods. Was carried out.
1. 1. Adhesion test When the test piece of the thermoplastic elastomer resin composition was removed from the evaluation sample, the adhesive state between the test piece and the cyclic polyolefin resin film was confirmed. The evaluation criteria are as follows.
⊚: The test piece and the film can be easily peeled off without applying any special force.
◯: The test piece and the film can be peeled off, although some force is required.
X: It takes a considerable amount of force to peel off the test piece and the film, or it cannot be peeled off. 2. 2. Whitening confirmation test A test piece of the thermoplastic elastomer resin composition was removed from the evaluation sample, and a change in appearance of the portion in contact with the test piece of the remaining cyclic polyolefin resin film was confirmed. The evaluation criteria are as follows.
⊚: No change is observed in the film.
◯: The film is slightly whitened, but there is no problem.
X: Significant changes such as whitening and cracking are observed in the film.

From Table 1, it can be seen that the thermoplastic elastomer compositions of Examples 1 and 2 are excellent in hardness, compression set, adhesion prevention property with cyclic polyolefin resin, and whitening prevention property.
On the other hand, in Comparative Example 1 in which the block copolymer A was not used, the raw materials could not be uniformly kneaded and sampling could not be performed.
Further, Comparative Example 2 in which a styrene-isobutylene-styrene block copolymer was used instead of isobutylene polymer B, Comparative Example 3 in which an ethylene-butene copolymer was used, and Comparative Example 4 in which a polypropylene-based resin C was not used. However, the compression resistance is insufficient, and there is a problem of sticking to the cyclic polyolefin resin.

Claims (11)

A medical device having a housing made of a cyclic polyolefin resin and a sealing component made of a thermoplastic elastomer composition, and the housing and the sealing component are in contact with each other.
The thermoplastic elastomer composition contains 25 to 100 parts by mass of isobutylene polymer B and 5 to 100 parts by mass of polypropylene-based resin C with respect to 100 parts by mass of block polymer A.
A hydrogenated product of a block copolymer R in which the block polymer A has two or more polymer blocks P containing a styrene unit as a constituent unit and one or more polymer blocks Q containing a conjugated diene unit as a constituent unit. It is a polymer having a styrene unit content of 20 to 50% by mass based on the total constituent monomer units and a mass average molecular weight of 150,000 to 350,000.
The conjugated diene unit, which is a constituent unit of the polymer block Q, is an isoprene unit.
The proportion of 3,4-bonds in the isoprene unit in the polymer block Q is 30 to 60 mol%, and the proportion of 1,4-bonds is 20 to 50 mol%.
A medical device having a flexural modulus of the polypropylene resin C of 1,000 to 3,000 MPa. The medical device according to claim 1, wherein the isobutylene polymer B has a viscosity average molecular weight of 5,000 to 100,000. The medical device according to claim 1 or 2, wherein the polypropylene-based resin C is polypropylene. Claim 1 that the thermoplastic elastomer composition further contains 10 to 70 parts by mass of talc D and / or 0.1 to 20 parts by mass of silicone oil E with respect to 100 parts by mass of the block polymer A. The medical device according to any one of 3 to 3 . The medical device according to claim 4 , wherein the thermoplastic elastomer composition contains silicone oil E, and the kinematic viscosity of silicone oil E at 25 ° C. is 50 to 2,000 cSt. A thermoplastic elastomer composition containing 25 to 100 parts by mass of isobutylene polymer B and 5 to 100 parts by mass of polypropylene-based resin C with respect to 100 parts by mass of block polymer A.
A hydrogenated product of a block copolymer R in which the block polymer A has two or more polymer blocks P containing a styrene unit as a constituent unit and one or more polymer blocks Q containing a conjugated diene unit as a constituent unit. It is a polymer having a styrene unit content of 20 to 50% by mass based on the total constituent monomer units and a mass average molecular weight of 150,000 to 350,000.
The conjugated diene unit, which is a constituent unit of the polymer block Q, is an isoprene unit.
The proportion of 3,4-bonds in the isoprene unit in the polymer block Q is 30 to 60 mol%, and the proportion of 1,4-bonds is 20 to 50 mol%.
A thermoplastic elastomer composition having a flexural modulus of the polypropylene resin C of 1,000 to 3,000 MPa. The thermoplastic elastomer composition according to claim 6 , wherein the isobutylene polymer B has a viscosity average molecular weight of 5,000 to 100,000. The thermoplastic elastomer composition according to claim 6 or 7 , wherein the polypropylene-based resin C is polypropylene. Further, according to any one of claims 6 to 8 , it contains 10 to 70 parts by mass of talc D and / or 0.1 to 20 parts by mass of silicone oil E with respect to 100 parts by mass of block polymer A. The thermoplastic elastomer composition described. The thermoplastic elastomer composition according to claim 9 , which comprises silicone oil E and has a kinematic viscosity of silicone oil E at 25 ° C. of 50 to 2,000 cSt. The thermoplastic elastomer composition according to any one of claims 6 to 10 , which is a thermoplastic elastomer composition for molding a sealing component of a medical device.