JPH0716292A - Material for antithrombogenic medical instrument - Google Patents

Abstract

PURPOSE:To provide a material for an antithrombogenic medical instrument composed of a specific graft copolymer having high mechanical strength, heat resistance or the like, showing high antithrombogenic characteristics particularly with a very small number of deposited thrombocytes, and ensuring high safety. CONSTITUTION:This is an antithrombogenic medical instrument material, featuring the composition thereof as a graft copolymer where a radical-polymerizable monomer having two or more hydroxyl groups in a molecule and/or a radical- polymerizable monomer having a bonding unit expressed by the following general formula (1), is graft copolymerized onto a thermoplastic elastomer. The formula (1) is [CH(R)CH2O]n, where R stands for a hydrogen atom or a methyl group, and (n) for an integer between 2 and 100.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antithrombotic material for medical devices, which is composed of a graft copolymer having excellent antithrombogenicity.

[0002]

2. Description of the Related Art In recent years, various disposable medical devices have been used. Inexpensive polyvinyl chloride is most widely used as a material for these devices, but the elution of plasticizers, stabilizers, and the like mixed therein is a problem. Therefore, as a material that does not use a plasticizer or the like, a thermoplastic elastomer including a polybutadiene block and / or a polyisoprene block and a polystyrene block, a thermoplastic elastomer in which an ethylene-propylene random copolymer and polypropylene are blended, and the like have been proposed. There is. However, when these polyvinyl chloride and thermoplastic elastomers are used in medical devices that come into contact with blood such as blood circuit tubes, blood vessel catheters and blood storage bags, thrombus formation and blood coagulation acceleration on the material surface There is a problem that such things occur. Therefore, from the therapeutic point of view, administration of antithrombotic drugs such as heparin has been attempted to avoid thrombus formation, blood coagulation, etc. This will weaken the sex and is not always the preferred method. Therefore, there is a strong demand for a material having an antithrombotic property added to the material itself, and for example, an antithrombotic material having a thrombolytic agent such as urokinase immobilized on the surface of the material is known. However, such a material to which a thrombolytic agent is immobilized is generally expensive, and although it is suitable for a device that is implanted in the human body for a long period of time, a device that is used only for a short period is economically advantageous. There's a problem. In addition, although attempts have been made to impart antithrombogenicity to the material surface by sputtering, plasma treatment, etc., it is often difficult to perform appropriate surface treatment depending on the shape of the equipment to be treated, etc. The stability of the treated surface is also insufficient, and there is a problem that the surface characteristics deteriorate with the lapse of time after the treatment.

[0003]

Therefore, the present invention has good mechanical strength, heat resistance, etc., and in particular, has an extremely small number of adhered platelets and has excellent antithrombotic properties required for medical use. It is an object of the present invention to provide a material for an antithrombotic medical device, which is made of a specific graft copolymer having excellent safety.

[0004]

Means for Solving the Problems That is, the present invention provides a radically polymerizable monomer having two or more hydroxyl groups in the molecule (hereinafter referred to as “polyhydroxy monomer”) and / or the following general formula. An antithrombotic medical treatment comprising a graft copolymer obtained by graft-polymerizing a radical-polymerizable monomer having a bonding unit represented by the following (hereinafter referred to as "polyether monomer") onto a thermoplastic elastomer. Material for equipment-[CH (R) CH ₂ O] n- (1) (where R represents a hydrogen atom or a methyl group, and n is 2 to
It is an integer of 100. ), Involved in.

The present invention will be described in detail below, which will clarify the purpose, constitution and effect of the present invention. The thermoplastic elastomer used in the present invention is a block copolymer having a molecule-constraining component that suppresses plastic deformation, that is, a hard segment, and a component having rubber elasticity, that is, a soft segment, in the molecule.

Examples of such a thermoplastic elastomer include, for example, one or more polymer blocks derived from an aromatic vinyl compound as a hard segment and one or more polymer blocks derived from a conjugated diene compound as a soft segment. A styrene block copolymer comprising: a hydrogenated product of the styrene block copolymer; a polypropylene block as a hard segment, and an ethylene-propylene random copolymer block and / or an ethylene-propylene-non-conjugated diene as a soft segment. Olefin block copolymer consisting of random copolymer block; urethane block copolymer consisting of polyurethane block as hard segment and polyether block, polyester block etc. as soft segment An ester block copolymer consisting of an aromatic polyester block as a hard segment and a polyether block or polyester block as a soft segment; a polyamide block as a hard segment and a polyether block or polyester block as a soft segment An amide block copolymer; a crystalline 1,2-polybutadiene comprising 1,2-syndiotactic polybutadiene as a soft segment and amorphous polybutadiene as a soft segment, and the like can be mentioned. These thermoplastic elastomers can be used alone or in admixture of two or more.

Among these thermoplastic elastomers, a polymer block derived from an aromatic vinyl compound (eg, styrene, α-methylstyrene, vinyltoluene) as a hard segment and a polymer derived from butadiene as a soft segment. Styrenic block copolymer consisting of a block (for example, styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer, etc.); a polymer block derived from an aromatic vinyl compound as a hard segment, and a soft segment As a styrene block copolymer consisting of a polymer block derived from isoprene (for example, styrene-isoprene block copolymer, styrene-isoprene-styrene block copolymer, etc.); hydrogenated products thereof (for example, styrene-ethylene). Down - butylene - styrene block copolymer); or crystalline 1,2-polybutadiene is preferable.

The styrenic block copolymer is produced by sequentially adding each monomer constituting the block copolymer in an inert solvent and polymerizing it using an anionic polymerization catalyst such as a lithium catalyst. can do. A method for producing a block copolymer by such anionic polymerization is described in, for example, Japanese Patent Publication No. 40-23798. The styrene block copolymer can also be produced by a coupling reaction of a precursor polymer having a butadiene unit and / or an isoprene unit and having a living anion terminal formed by anionic polymerization.

Further, the hydrogenated product of the styrene-based block copolymer may be obtained, for example, by using a hydrogenation catalyst in an inert solvent for a part of butadiene units and / or isoprene units in the styrene-based block copolymer. It can be produced by hydrogenation. Such a hydrogenation method is described in, for example, JP-A-59-133203. The hydrogenation rate in this case is butadiene units and /
Alternatively, it is preferably 90% or less of the double bonds in the isoprene unit.

The polystyrene equivalent weight average molecular weight of the styrene block copolymer is usually 30,000 to 6
0,000, preferably 50,000 to 500,000
It is 0.

The thermoplastic elastomer is derived from olefin (co) polymers such as polyethylene, polypropylene, ethylene-propylene random copolymers and poly-4-methyl-1-pentene; butadiene and / or isoprene. Conjugated diene system (co) such as block copolymers composed of repeating units other than monomer units, polybutadiene, polyisoprene, styrene-butadiene random copolymers, styrene-isoprene random copolymers, etc.
Polymers: Aromatic vinyl (co) polymers such as polystyrene and polyvinylpyridine; Vinyl halide (co) polymers such as polyvinyl chloride, polyvinylidene chloride and polytetrafluoroethylene; Polymethylmethacrylate, trifluoroethyl (Meth) acrylic acid ester-based (co) polymers such as (meth) acrylate and hexafluoroisopropyl (meth) acrylate; polyacrylonitrile,
One or more kinds of vinyl cyanide-based (co) polymers such as polyvinylidene cyanide; polyvinyl acetate; polyvinyl alcohol and the like may be blended and used.

The amount of these other polymers used is usually 30 parts by weight or less per 100 parts by weight of the thermoplastic elastomer.

Next, examples of the polyhydroxy monomer used in the present invention include N, N'-di (hydroxymethyl) (meth) acrylamide and N, N'-di (hydroxyethyl) (meth) acrylamide. , N, N'-di (hydroxypropyl) (meth) acrylamide, N, N'-di (hydroxyalkyl) (meth) acrylamides such as N, N'-di (hydroxybutyl) (meth) acrylamide; N
-(1,1,1-trihydroxymethyl) methyl (meth) acrylamide, N- (1,1,1-trihydroxyethyl) methyl (meth) acrylamide, N- (1,
1,1-trihydroxypropyl) methyl (meth) acrylamide, N- (1,1,1-trihydroxybutyl) methyl (meth) acrylamide, N, N′-di (1,
1,1-trihydroxymethyl) methyl (meth) acrylamide, N, N'-di (1,1,1-trihydroxyethyl) methyl (meth) acrylamide, N, N'-di (1,1,1- Mono- or di (trihydroxyalkyl) (meth) acrylamides such as trihydroxypropyl) methyl (meth) acrylamide, N, N'-di (1,1,1-trihydroxybutyl) methyl (meth) acrylamide; 3-dihydroxypropyl (meth) acrylate, 2,3-dihydroxybutyl (meth) acrylate, 2,4-dihydroxybutyl (meth) acrylate, 3,4-dihydroxybutyl (meth) acrylate, trimethylolalkane mono (meth) acrylate (The carbon number of the alkane is, for example, 1 to 3), tetramethylol alkane mono (meth) ac Rate (number of carbon atoms in the alkane, for example 1 to 3) may be mentioned polyhydric alcohol mono (meth) acrylates of trihydric or higher such like.
These polyhydroxy monomers can be used alone or in admixture of two or more.

Among the above polyhydroxy monomers, preferred monomers are N, N'-di (hydroxymethyl) methacrylamide, N, N'-di (hydroxyethyl) methacrylamide, N, N'-dimeth (Hydroxypropyl) methacrylamide, N- (1,1,1-trihydroxymethyl) methylacrylamide, N- (1,1,1-trihydroxyethyl) methylacrylamide, N- (1,1,1-trihydroxy Propyl) methyl acrylamide, 2,3-
Dihydroxypropyl methacrylate and 2,3-dihydroxybutyl methacrylate, and particularly preferably,
N, N'-di (hydroxymethyl) methacrylamide, N, N '
-Di (hydroxyethyl) methacrylamide, N-
(1,1,1-trihydroxymethyl) methyl acrylamide, N- (1,1,1-trihydroxyethyl) methyl acrylamide, and 2,3-dihydroxypropyl methacrylate.

Examples of the polyether monomer used in the present invention include methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxynonaethylene glycol (meth) acrylate and methoxytetradecaethylene glycol. Methoxypolyethylene glycol (meth) acrylates such as (meth) acrylate and methoxytriacontane ethylene glycol (meth) acrylate; ethoxydiethylene glycol (meth) acrylate, ethoxytriethylene glycol (meth) acrylate, ethoxynonaethylene glycol (meth) acrylate, Ethoxy tetradeca ethylene glycol (meth) acrylate, ethoxy triacontane ethylene glycol (meth) Ethoxy polyethylene glycol (meth) acrylates such as acrylates; propoxydiethylene glycol (meth) acrylate, propoxytriethylene glycol (meth) acrylate, propoxynonaethylene glycol (meth) acrylate, propoxytetradecaethylene glycol (meth) acrylate, propoxytriacontane Propoxy polyethylene glycol (meth) acrylates such as ethylene glycol (meth) acrylate; butoxydiethylene glycol (meth) acrylate, butoxytriethylene glycol (meth) acrylate, butoxynona ethylene glycol (meth) acrylate, butoxytetradeca ethylene glycol (meth) Acrylate, butoxytriacontane ethylene glycol ( Butoxy polyethylene glycol (meth) acrylates such as acrylate; methoxydipropylene glycol (meth) acrylate, methoxytripropylene glycol (meth) acrylate, methoxynonapropylene glycol (meth) acrylate, methoxytetradecapropylene glycol (meth) acrylate , Methoxytriacontane propylene glycol (meth) acrylate and other methoxy polypropylene glycol (meth) acrylates; ethoxydipropylene glycol (meth) acrylate, ethoxytripropylene glycol (meth) acrylate, ethoxynonapropylene glycol (meth)
Examples thereof include ethoxy polypropylene glycol (meth) acrylates such as acrylate, ethoxytetradecapropylene glycol (meth) acrylate, and ethoxytriacontane propylene glycol (meth) acrylate. Further, the polyether monomer may have two or more kinds of bond units represented by the general formula (1). These polyether monomers can be used alone or in admixture of two or more.

Among the above-mentioned polyether monomers, preferred monomers are methoxydiethylene glycol methacrylate, methoxytriethylene glycol methacrylate,
The above-mentioned general formula (1) such as methoxynonaethylene glycol methacrylate, ethoxydiethylene glycol methacrylate, ethoxytriethylene glycol methacrylate, ethoxynonaethylene glycol methacrylate, etc.
N in 2 to 9 is particularly preferable, and methoxytriethylene glycol methacrylate and ethoxytriethylene glycol (meth) acrylate are particularly preferable.

The radical-polymerizable monomer used in the graft polymerization of the present invention may have two or more hydroxyl groups and the bonding unit represented by the general formula (1) at the same time in the molecule. These monomers can be used alone or in admixture of two or more.

In the present invention, the graft amount of the polyhydroxy monomer and / or the polyether monomer is preferably 1 to 60% by weight of the graft copolymer, and more preferably 5 to 50% by weight. If the graft amount of these monomers is less than 1% by weight, the anticoagulant properties of the resulting graft copolymer may be insufficient, and 60% by weight
When it exceeds, the mechanical properties of the resulting graft copolymer,
Workability and the like tend to decrease. Further, if desired, the polyhydroxy monomer and / or the polyether monomer may be mixed with other radically polymerizable monomer within the range of 10% by weight or less of those monomers.

The graft copolymer in the present invention can be produced by various methods. The preferable production method is, first, by swelling or dissolving the thermoplastic elastomer in a suitable organic solvent to initiate radical polymerization. A method of graft-polymerizing a polyhydroxy monomer and / or a polyether monomer in the presence of an agent, and second, a thermoplastic elastomer is melted without substantially using an organic solvent to form a radical polymerization initiator. The method of graft-polymerizing a polyhydroxy monomer and / or a polyether monomer in the presence of

In the first method, as the organic solvent, linear or branched acyclic saturated hydrocarbons such as pentane, hexane, heptane, 2-methylpentane, 2,4-dimethylhexane; Cyclic saturated hydrocarbons such as cyclohexane, methylcyclohexane and menthane;
Acyclic unsaturated hydrocarbons such as 1-pentene, 2-pentene, 1-hexene, 1-octene, 2-ethyl-1-butene; cyclic non-cyclic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cyclopentene, cyclohexene Saturated hydrocarbons; dichloromethane, trichloromethane, tetrachloromethane, 1,2-dichloroethane, 1,1,2,
2-tetrachloroethane, 1-chloropentane, fluorobenzene, trifluorobenzene, chlorobenzene,
Halogenated hydrocarbons such as dichlorobenzene; ethers such as diethyl ether, dibutyl ether, dioxane, tetrahydrofuran, tetrahydropyran, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethylene glycol monomethyl ether, etc. You can These organic solvents may be used alone or in admixture of two or more.

In the first method, in particular, by carrying out the graft polymerization in a swollen state of the thermoplastic elastomer, it is possible to preferentially or selectively cause the graft polymerization in a local portion of the elastomer, for example, a soft segment portion. . For example, the antithrombogenic segment can be introduced into the amorphous polybutadiene portion by performing graft polymerization in a state where crystalline 1,2-polybutadiene is swollen with a hexane solution of a monomer.

When the graft polymerization is carried out in the presence of an organic solvent, particularly in a solution of a thermoplastic elastomer, the reaction mixture after polymerization is treated with methanol, ethanol,
The thermoplastic elastomer produced can be recovered by adding it to a poor solvent such as 1-propanol or 2-propanol.

The graft polymerization in the first method is carried out in an inert atmosphere (for example, nitrogen), usually at a temperature of 0 to 150 ° C. for 0.5 to 48 hours.

In the second method, for example, (a) a thermoplastic elastomer is melted using a mixer such as a plastomill or a kneader, or a single-screw or twin-screw extruder, and then a radical polymerization initiator is mixed. The monomer
A method of performing graft polymerization while sequentially or continuously adding and kneading or extruding, (b) a monomer mixed with a radical polymerization initiator is preliminarily penetrated into a thermoplastic elastomer, and then the kneader, extruder, etc. are used. It can be carried out by a method of kneading or graft polymerizing while extruding.

The graft polymerization conditions in the second method are as follows:
Although it depends on the melting temperature of the thermoplastic elastomer, it is usually carried out at a temperature of 100 to 250 ° C. for 10 to 60 minutes.

Various peroxides, azo compounds and the like can be used as the radical polymerization initiator in the graft polymerization of the first method, the second method and the like. Specific examples of the radical polymerization initiator include persuccinic acid, peracetic acid, t-butyl peracetate, cumyl peroctoate, t-butyl perbenzoate, octanol peroxide, lauroyl peroxide, benzoyl peroxide, and t-butyl. Peroxides such as hydroperoxide, p-menthane hydroperoxide, cumene hydroperoxide, di-t-butyl peroxide, dicumyl peroxide; 2,2-azobis (isobutyronitrile), 2,2 '-Azobis (4-methoxy-2,4-
Examples thereof include azo compounds such as dimethylvaleronitrile). The addition amount of these radical polymerization initiators is
It is about 0.1 to 10% by weight with respect to the thermoplastic elastomer.

After the graft polymerization, unreacted radical polymerizable monomers, radical polymerization initiators and decomposition products thereof are
The safety as a medical material can be further enhanced by washing and removing with a solvent such as methanol, ethanol, 1-propanol, 2-propanol or the like, or by heating and distilling.

Further, the graft copolymer in the present invention finally has a graft copolymer having a polymer structure corresponding to that obtained by graft-polymerizing a polyhydroxy monomer and / or a polyether monomer on a thermoplastic elastomer. Any polymer may be used. Therefore, the graft copolymer may be radical-polymerizable precursor monomer (hereinafter referred to as "precursor monomer") other than the method of directly graft-polymerizing the polyhydroxy monomer and / or the polyether monomer. It can also be obtained by carrying out a chemical post-treatment with an acid, an alkali or the like after graft-polymerizing) to a thermoplastic elastomer.

Examples of such precursor monomers include glycidyl (meth) acrylate; glycidyl methyl itaconate, glycidyl ethyl itaconate, glycidyl propyl itaconate, glycidyl butyl itaconate, glycidyl pentyl itaconate, glycidyl hexyl itaconate, etc. Glycidyl alkyl itaconates; glycidyl methyl fumarate, glycidyl ethyl fumarate, glycidyl propyl fumarate, glycidyl butyl fumarate, glycidyl pentyl fumarate, glycidyl hexyl fumarate, and the like. These precursor monomers may be used alone or in admixture of two or more.

Of the above precursor monomers, preferred monomers are glycidyl methacrylate, glycidyl methyl itaconate, glycidyl ethyl itaconate and glycidyl propyl itaconate, and glycidyl methacrylate is particularly preferred.

Graft polymerization of the precursor monomer onto the thermoplastic elastomer can also be carried out by various methods, but the above-mentioned first method or second method for polyhydroxy monomer and / or polyether monomer It is preferable to carry out in the same manner as the above method.

When a precursor monomer having a glycidyl group is graft-polymerized on a thermoplastic elastomer, hydrochloric acid,
By post-treatment with inorganic acids such as sulfuric acid, inorganic bases such as sodium hydroxide and potassium hydroxide, amines such as monoethanolamine and diethanolamine, etc. Can be converted to coalesced. Particularly, in the post-treatment with the amines, the reaction can be promoted by adding pyridine or the like. Such post-processing condition is 0
At a temperature of ~ 150 ° C, 0.5-48 hours is sufficient.

The graft copolymer obtained as described above contains plasticizers, antioxidants, light stabilizers, fillers, reinforcing materials, dyes and pigments in consideration of processability and storage stability. Various additives can be blended. Further, if desired, the above-mentioned other resin may be blended in such an amount that the characteristics of the graft copolymer are not impaired.

The graft copolymer in the present invention can be easily molded by various molding methods such as injection molding, extrusion molding, blow molding, thermoforming, cast molding, calender molding, pressure molding and laminate molding. It is also possible and secondary processing is easy.

The graft copolymer in the present invention does not need to use a particularly expensive raw material, and the graft polymerization step can be industrially advantageously carried out.
In addition, the original mechanical strength and heat resistance of the thermoplastic elastomer are not impaired, and in particular, it has excellent antithrombogenicity even in the long term. Therefore, such a graft copolymer is extremely excellent especially as a material for medical devices.

The antithrombotic medical device composed of the graft copolymer in the present invention means an artificial heart, artificial heart lung, artificial kidney, artificial liver, artificial valve, which is used in contact with blood.
Means artificial devices such as artificial blood vessels, arteriovenous shunts, catheters for blood vessels, blood circuits, blood collection devices, particularly disposable medical devices that require antithrombotic properties such as blood storage bags, and their components .

[0037]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples. However, the present invention is not limited to these examples unless it exceeds the gist. Here, the performance evaluation of each material was performed in the following manner.

Safety test: An eluate test and a hemolytic test were carried out in accordance with the Japanese Pharmacopoeia infusion container plastic container test method.

Antithrombotic test: Plasma prepared from rabbit fresh blood was immersed in plasma at 37 ° C. for 1 hour and then observed with a scanning electron microscope to measure the number of attached platelets.

Example 1 In a 500 ml round bottom flask equipped with a cooling tube, 5 g of crystalline 1,2-polybutadiene (trade name RB820, manufactured by Nippon Synthetic Rubber Co., Ltd.) as a thermoplastic elastomer and 2 as a polyhydroxy monomer were used. A solution of 2 g of 3,3-dihydroxypropyl methacrylate dissolved in 100 ml of toluene was added, 50 mg of benzoyl peroxide was further added, and the mixture was refluxed for 10 hours in a nitrogen atmosphere to carry out graft polymerization. After the graft polymerization, the reaction liquid was coagulated with methanol and then vacuum dried at 70 ° C. to obtain 6.8 g of a graft copolymer. A sheet having a width of 5 mm and a thickness of 0.3 mm was prepared from this graft copolymer by a hot press molding machine, and a safety test and an antithrombotic test were conducted. The evaluation results are shown in Table 1.

Example 2 The same as Example 1 except that 5 g of a hydrogenated product of a styrene / butadiene block copolymer (polystyrene-equivalent weight average molecular weight: 78,000, hydrogenation rate: 98%) was used as the thermoplastic elastomer. Graft polymerization,
5.5 g of a graft copolymer was obtained. Various tests were conducted on this graft copolymer in the same manner as in Example 1.
The evaluation results are shown in Table 1.

Example 3 5 g of the same hydrogenated product as in Example 2 and 3 g of glycidyl methacrylate as a precursor monomer were dissolved in 100 ml of toluene, and 50 mg of benzoyl peroxide was added,
Graft polymerization was carried out by refluxing for 5 hours in a nitrogen atmosphere. After the graft polymerization, 5 cc of diethanolamine was added and reacted at 60 ° C. for 5 hours, and then post-treated in the same manner as in Example 1 to have a branched chain composed of 2,3-dihydroxypropyl methacrylate as a polyhydroxy monomer. 7.5 g of a graft copolymer was obtained. Various tests were conducted on this graft copolymer in the same manner as in Example 1. The evaluation results are shown in Table 1.

Example 4 5 g of the same hydrogenated product as in Example 2 and 2 g of methoxynonaethylene glycol methacrylate as a polyether monomer were dissolved in 100 ml of dioxane, and 50 mg of benzoyl peroxide was added to the solution. Graft polymerization was carried out by refluxing for 10 hours. After the graft polymerization, the same treatment as in Example 1 was carried out to obtain 6.5 g of a graft copolymer. Various tests were conducted on this graft copolymer in the same manner as in Example 1. Table 1 shows the evaluation results.
Shown in.

Example 5 The same as Example 1 except that 5 g of a hydrogenated product of a styrene / isoprene block copolymer (polystyrene-equivalent weight average molecular weight: 98,000, hydrogenation rate: 97%) was used as the thermoplastic elastomer. Graft polymerization,
6.2 g of a graft copolymer was obtained. Various tests were conducted on this graft copolymer in the same manner as in Example 1.
The evaluation results are shown in Table 1.

Comparative Example 1 The crystalline 1,2-polybutadiene used in Example 1 was subjected to various tests in the same manner as in Example 1. The evaluation results are shown in Table 1.

Comparative Example 2 Various tests were conducted on the hydrogenated products of the styrene / butadiene block copolymers used in Examples 2 to 4 in the same manner as in Example 1. The evaluation results are shown in Table 1.

Comparative Example 3 Various tests were carried out in the same manner as in Example 1 on a non-plasticized soft polyvinyl chloride for medical use (trade name: Smedica V, manufactured by Sekisui Chemical Co., Ltd.). The evaluation results are shown in Table 1.

Comparative Example 4 Various tests were conducted on the hydrogenated product of the styrene / isoprene block copolymer used in Example 5 in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0049]

[Table 1]

[0050]

EFFECTS OF THE INVENTION According to the present invention, there is provided a disposable antithrombotic medical device material comprising a graft copolymer which has an extremely small number of adhered platelets, remarkably excellent antithrombogenicity and excellent safety. . Moreover, the graft copolymer has good mechanical strength, heat resistance and the like, and can be manufactured and processed industrially extremely advantageously.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenji Yasuda 2-11-24 Tsukiji, Chuo-ku, Tokyo Within Nippon Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] 1. A graft copolymer of a radical polymerizable monomer having two or more hydroxyl groups in the molecule and / or a radical polymerizable monomer having a bonding unit represented by the following general formula (1) on a thermoplastic elastomer. A material for an antithrombotic medical device, which is composed of a polymerized graft copolymer. -[CH (R) CH ₂ O] n- (1) (wherein R represents a hydrogen atom or a methyl group, and n is 2 to
It is an integer of 100. )