JPH1067894A - Resin composition and medical supplies produced therefrom - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin compsn. which gives a molded item excellent in softness, clarity, heat resistance, and blood compatibility by compounding a polyopropylene resin with a specific hydrogenated block copolymer. SOLUTION: This compsn. comprises 10-90wt.% polypropylene resin having a melt flow rate of 0.1-500 and 90-10wt.% hydrogenated block copolymer which contains at least one polymer block A formed from an arom. vinyl compd. and at least one polyisoprene block Bhaving a content of 1,2- and 3,4-bonds of 10-75mol% and has a content of arom. vinyl compd. units of 10-40wt.% and a degree of hydrogenation of carbon-carbon double bonds of block B of 70% or higher or which contains at least one polymer block A and at least one polymer block C formed from a mixture of isoprene and butadiene in a vrt. ratio of (5/95)-(95/5) and having a content of 1,2- and 3,4-bonds of 20-85mol% and has a content of arom. vinyl compd. units of 10-40wt.% and a degree of hydrogenation of carbon-carbon double bonds of block C of 70% or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a resin composition having excellent flexibility and transparency, and particularly suitable for medical use, and a medical device comprising the composition.

[0002]

2. Description of the Related Art Medical devices such as catheters, blood circuits, and blood bags are required to have excellent flexibility and transparency. Therefore, soft vinyl chloride, which is a material having both of these properties, is used. Often manufactured. However, soft vinyl chloride contains a relatively large amount of a low-molecular-weight plasticizer such as DOP (dioctyl phthalate), and the problem of elution of the plasticizer has been pointed out from the viewpoint of safety. In recent years, disposable medical devices have been promoted, and incineration has been increasing after use.However, medical devices that use soft vinyl chloride generate toxic gas when incinerated, causing environmental pollution. There is a problem that causes.

[0003] Medical equipment made of soft vinyl chloride is generally sterilized using ethylene oxide gas (EOG), but there is a concern that residual EOG may adversely affect patients. In order to eliminate the influence of residual EOG, switching to autoclave sterilization (high-pressure steam sterilization), which is another sterilization method, can be considered. However, soft vinyl chloride has poor heat resistance and cannot withstand this sterilization method.

[0004] For this reason, the replacement of soft vinyl chloride with another material as a material for medical devices has recently been studied, and as a resin composition which is excellent in flexibility and provides a molded product suitable for medical use, it has been proposed. In Japanese Unexamined Patent Publication No. Hei 4-159344,
A resin composition comprising a hydrogenated product of an olefin resin and a styrene-butadiene block copolymer and a hydrogenated product of a styrene-isoprene block copolymer has been proposed.

[0005]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-open No. Hei 4-15
The resin composition described in Japanese Patent No. 9344 has a characteristic that a molded product having excellent flexibility is provided, and even if the molded product is incinerated, no toxic gas is generated. However, molded articles obtained from such resin compositions are not sufficiently satisfactory in another property required for medical devices, namely, transparency, and there is room for improvement in this respect. Thus, the present invention provides a molded article having excellent flexibility and transparency, and further, does not generate toxic gas when incinerated, has sufficient heat resistance, and provides a medical device which can withstand autoclave sterilization. It is an object to provide a resin composition.

[0006]

According to the present invention, the above object is achieved by providing at least one polymer block A comprising a polypropylene resin (a) and (b-1) a vinyl aromatic compound; , 2-bond and 3,4-bond content is 10
The polyisoprene block B has at least one polyisoprene block B having a content of at least 75% by mole, the content of the vinyl aromatic compound is 10 to 40% by weight, and 70% or more of the carbon-carbon double bond of the polyisoprene block B is A hydrogenated block copolymer obtained by hydrogenation, (b-2) one or more polymer blocks A comprising a vinyl aromatic compound, and isoprene and butadiene mixed in a weight ratio of 5/95 to 95/5. Having at least one polymer block C having a content of 1,2-bonds and 3,4-bonds of 20 to 85 mol% and a content of a vinyl aromatic compound of 10 to 40% by weight, and a hydrogenated block copolymer obtained by hydrogenating 70% or more of the carbon-carbon double bonds of the polymer block C; and (b-3) a polymer comprising a vinyl aromatic compound. United block A FOB, and 1,2 have the content of coupling 45 mol% or more in which the polybutadiene block D one or more, the content of the vinyl aromatic compound is 10 to 4
0% by weight, and at least one selected from the group consisting of hydrogenated block copolymers obtained by hydrogenating 70% or more of carbon-carbon double bonds of polybutadiene block D.
Resin composition comprising a kind of hydrogenated block copolymer (b), the ratio of both being polypropylene resin (a) / hydrogenated block copolymer (b) = 10/90 to 90/10 (weight ratio) It is solved by providing things.

As the polypropylene resin (a) constituting the resin composition of the present invention, known resins can be used, and any of homopolypropylene, random polypropylene and block polypropylene may be used.
Further, the polypropylene resin (a) may be used alone or in combination of two or more. The melt viscosity of the polypropylene resin (a) is preferably in the range of 0.1 to 500 when measured at 230 ° C. under a load of 2160 g according to ASTM D-1238. More preferably, it is within the range.

On the other hand, the hydrogenated block copolymer (b) constituting the resin composition of the present invention comprises (b-1) at least one polymer block A comprising a vinyl aromatic compound, and 1,
Poly-polypropylene having a content of 2-bonds and 3,4-bonds (hereinafter, the contents of 1,2-bonds and 3,4-bonds may be abbreviated as vinyl bond content) of 10 to 75 mol% Hydrogenation having at least one isoprene block B, a content of vinyl aromatic compound of 10 to 40% by weight, and hydrogenation of 70% or more of carbon-carbon double bonds of polyisoprene block B A block copolymer, (b-2) at least one or more polymer blocks A comprising a vinyl aromatic compound, and isoprene and butadiene in 5/95 to 95 /
5 comprising at least one polymer block C having a vinyl bond content of 20 to 85 mol% and a vinyl aromatic compound content of 1 to 5.
0 to 40% by weight, and carbon of polymer block C
A hydrogenated block copolymer in which 70% or more of carbon double bonds are hydrogenated, and (b-3) at least one or more polymer blocks A composed of a vinyl aromatic compound, and 1,2-bonds It has at least one polybutadiene block D having a content of 45 mol% or more, a content of a vinyl aromatic compound of 10 to 40% by weight, and 70% or more of carbon-carbon double bonds of the polybutadiene block D. Is at least one polymer selected from the group consisting of hydrogenated block copolymers obtained by hydrogenation.

These hydrogenated block copolymers (b-
The polymer block A in (1), (b-2) and (b-3) is composed of a vinyl aromatic compound. Such vinyl aromatic compounds include, for example, styrene,
α-methylstyrene, 1-vinylnaphthalene, 3-methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-
Benzyl styrene, 4- (phenylbutyl) styrene and the like can be mentioned, among which styrene is preferable.

The number average molecular weight of the polymer block A is not particularly limited, but is preferably in the range of 2,500 to 20,000.

The content of the vinyl aromatic compound polymer in the hydrogenated block copolymer (b) is (b-1)
It is necessary that the content of each of the polymers (b-2) and (b-3) is in the range of 10 to 40% by weight.
When the content of the vinyl aromatic compound polymer in the hydrogenated block copolymer (b) is less than 10% by weight, the mechanical strength of the hydrogenated block copolymer (b) becomes insufficient. If the content of the vinyl aromatic compound polymer in the hydrogenated block copolymer (b) exceeds 40% by weight, the melt viscosity of the hydrogenated block copolymer (b) becomes extremely high, and the polypropylene resin (a) And it is difficult to mix them uniformly, which limits the molding process.

The polyisoprene block B constituting the hydrogenated block copolymer (b-1) has a vinyl bond content of 1
It must be in the range of 0 to 75 mol% and 70% or more of the carbon-carbon double bonds must be hydrogenated.
When the vinyl bond content in the polyisoprene block B is less than 10 mol%, the transparency of the molded product obtained from the resin composition is not sufficient, and the vinyl bond content in the polyisoprene block B is 75 mol%. Exceeds the glass transition temperature of the polymer block B (T
g) is too high, and the flexibility of a molded product obtained from the resin composition is impaired.

Further, the carbon-polyisoprene block B
When the hydrogenation rate of the carbon double bond is less than 70%, the hydrogenated block copolymer (b-1) has inferior compatibility with the polypropylene resin (a), and the molded product obtained from the resin composition has Transparency is impaired.

Although the number average molecular weight of the polyisoprene block B is not particularly limited, it ranges from 10,000 to 200,000.
Is preferably within the range.

The polymer block C in the hydrogenated block copolymer (b-2) is composed of a mixture obtained by mixing isoprene and butadiene in a weight ratio of 5/95 to 95/5. And the vinyl bond content is 20 to 8
In the range of 5 mol%, and 7
It is necessary that 0% or more is hydrogenated.

In the mixture of isoprene and butadiene constituting the polymer block C, the content of isoprene is 9
When the content exceeds 5% by weight, the glass transition temperature (Tg) of the polymer block C becomes too high when the vinyl bond content is 75 mol% or more, and the flexibility of a molded product obtained from the resin composition is increased. Is impaired. On the other hand, in the mixture of isoprene and butadiene, the content of isoprene is 5% by weight.
Is less than 3, the vinyl bond content of the polymer block C is 3
When the amount is less than 0 mol%, the transparency of a molded product obtained from the resin composition is undesirably reduced.

When the vinyl bond content in the polymer block C is less than 20 mol%, the transparency of the molded product obtained from the resin composition is not sufficient, and the vinyl block content in the polymer block C is not sufficient. If the amount exceeds 85 mol%, the glass transition temperature (T
g) is too high, and the flexibility of a molded product obtained from the resin composition is impaired.

When the hydrogenation ratio of the carbon-carbon double bond of the polymer block C is less than 70%, the hydrogenated block copolymer (b-2) has poor compatibility with the polypropylene resin (a). In addition, the transparency of a molded product obtained from the resin composition is impaired.

The polymerization form of isoprene and butadiene in the polymer block C is not particularly limited, and may be any form such as random, block, or tapered. The number average molecular weight of the polymer block C is not particularly limited, but is preferably in the range of 10,000 to 200,000.

The polybutadiene block D in the hydrogenated block copolymer (b-3) has a vinyl bond content of at least 45 mol% and a carbon-carbon double bond of 7%.
It is necessary that 0% or more is hydrogenated. The vinyl bond content in the polybutadiene block D is 45
If it is less than mol%, the transparency of the molded product obtained from the resin composition is not sufficient.

The carbon-polybutadiene block D
When the hydrogenation rate of the carbon double bond is less than 70%, the hydrogenated block copolymer (b-3) is inferior in compatibility with the polypropylene resin (a) and the molded product obtained from the resin composition Transparency is impaired.

The bonding mode of each polymer block in the hydrogenated block copolymer (b) is not particularly limited, and may be linear, branched or any combination thereof. Specific examples of the molecular structure of the hydrogenated block copolymer (b) before hydrogenation are as follows: A- (BA) _n , (AB) _n , A- (C-
A) _n , (AC) _n , A- (DA) _n , (AD)
_n (where A is the polymer block A, B, C and D
Represents a polyisoprene block B, a polymer block C, and a polybutadiene block D, respectively, and n is an integer of 1 or more. The molecular structure of the hydrogenated block copolymer (b) before hydrogenation has a star shape (for example, (AB) _m X, where divinylbenzene, a tin compound, a silane compound, or the like is a coupling agent). m is an integer of 2 or more;
X represents a residue of a coupling agent).

As the hydrogenated block copolymer (b), those having the above-mentioned various molecular structures may be used alone, or for example, a mixture of a triblock type and a diblock type may be used. Two or more compounds having different molecular structures such as those described above may be used in combination. The number average molecular weight of the hydrogenated block copolymer (b) is 30,000 to 300,0.
It is preferably within the range of 00.

As a method for producing the hydrogenated block copolymer (b), conventionally known methods can be used. For example, the block copolymers obtained by the following methods (a) to (c) can be used. And the like. (A) A method in which a vinyl aromatic compound is polymerized using an alkyl lithium compound as an initiator, and then a conjugated diene compound and a vinyl aromatic compound are sequentially polymerized. (B) A method in which a vinyl aromatic compound and subsequently a conjugated diene compound are polymerized, and the obtained block copolymer is coupled using a coupling agent. (C) A method of polymerizing a conjugated diene compound using a dilithium compound as an initiator and then sequentially polymerizing a vinyl aromatic compound.

In the above method, as the alkyllithium compound, a compound having an alkyl group having 1 to 10 carbon atoms is used. Among them, methyllithium, ethyllithium, pentyllithium, n-butyllithium and s-butyllithium are used.
Butyllithium and t-butyllithium are preferred. Examples of the coupling agent include halogen compounds such as dichloromethane, dibromomethane, dichloroethane, dibromoethane, dibromobenzene, and tin tetrachloride;
Ester compounds such as phenyl benzoate and ethyl acetate; divinylbenzene and various silane compounds.
Further, examples of the dilithium compound include naphthalenedilithium and dilithiohexylbenzene.

The amount of the initiator or the coupling agent used is appropriately determined according to the desired molecular weight of the block copolymer.
With respect to 00 parts by weight, the initiator is 0.01 to 0.2 parts by weight,
The coupling agent is used within a range of 0.04 to 0.8 parts by weight.

The vinyl bond content in the polyisoprene block B, the polymer block C, and the polybutadiene block D (hereinafter sometimes abbreviated as a conjugated diene block) is determined by using a Lewis base as a cocatalyst at the time of polymerization. It can be controlled by using it. Examples of such Lewis bases include ethers such as dimethyl ether, diethyl ether and tetrahydrofuran; glycol ethers such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether; triethylamine, N, N, N ', N'-tetramethylethylenediamine (hereinafter referred to as Is abbreviated as TMEDA), and amine compounds such as N-methylmorpholine. The amount of the Lewis base used is one lithium atom in the polymerization initiator.
The amount is within the range of 0.1 to 1000 mol per mol.

In the polymerization, an organic solvent inert to the polymerization initiator is used as a solvent. As such a solvent, it is preferable to use an aliphatic hydrocarbon having 6 to 12 carbon atoms such as hexane and heptane; an alicyclic hydrocarbon such as cyclohexane and methylcyclohexane; and an aromatic hydrocarbon such as benzene.

The polymerization is usually carried out in a temperature range of 0 to 80 ° C. in any of the above polymerization methods (a) to (c). The reaction time is usually 0.5 to 50 hours.

Next, the block copolymer obtained by the above method may be used, for example, by reacting a molecular hydrogen with a known hydrogenation catalyst in a state of being dissolved in a solvent inert to the reaction. The hydrogenated block copolymer (b) is obtained by a known method. Examples of the hydrogenation catalyst used herein include Raney nickel; a heterogeneous catalyst in which a metal such as Pt, Pd, Ru, Rh, and Ni is supported on a carrier such as carbon, alumina, and diatomaceous earth; Ziegler-based catalysts comprising a combination of an organometallic compound comprising a Group VIII metal and an organoalkylaluminum compound such as triethylaluminum and triisobutylaluminum or an organolithium compound; transition metal bis (cyclopentane) such as titanium, zirconium and hafnium A metallocene catalyst comprising a combination of a dienyl) compound and an organometallic compound such as lithium, sodium, potassium, aluminum, zinc or magnesium is used. The hydrogenation is usually carried out when the hydrogen pressure is between normal pressure and 200 kg /
The reaction is performed at a reaction temperature of from room temperature to 250 ° C. in cm ² .
The reaction time is usually 0.1 to 100 hours. The hydrogenated block copolymer (b) obtained by hydrogenation is (i)
The reaction mixture is coagulated with methanol or the like and then heated or dried under reduced pressure, or (ii) the reaction liquid is poured into boiling water and subjected to so-called steam stripping for removing the solvent by azeotropic distillation, followed by heating or reduced pressure. Obtained by drying.

The mixing ratio of the polypropylene resin (a) and the hydrogenated block copolymer (b) in the resin composition of the present invention is as follows: polypropylene resin (a) / hydrogenated block copolymer (b) = 10 / It is in the range of 90 to 90/10 (weight ratio). When the proportion of the polypropylene-based resin (a) is less than the above range, the mechanical strength of a molded product obtained from the resin composition becomes insufficient, and blood compatibility also decreases. On the other hand, if the proportion of the polypropylene resin (a) exceeds the above range, both the flexibility and the transparency of the molded product obtained from the resin composition are reduced. The mixing ratio of the polypropylene resin (a) and the hydrogenated block copolymer (b) is 20.
/ 80 to 80/20 (weight ratio),
More preferably, it is 50/50 to 80/20 (weight ratio).

The resin composition of the present invention may contain various additives such as an antioxidant, an ultraviolet absorber, a light stabilizer, a colorant, and a crystal nucleating agent as long as the performance is not impaired. The amount of these additives used is usually in the range of 0.01 to 5 parts by weight based on 100 parts by weight of the total of the polypropylene resin (a) and the hydrogenated block copolymer (b). In addition, the resin composition of the present invention comprises a hydrogenated resin such as a hydrogenated coumarone-indene resin, a hydrogenated rosin resin, a hydrogenated terpene resin, an alicyclic hydrogenated petroleum resin, and an olefin and diolefin polymer. A tackifying resin such as an aliphatic resin may be added. The amount of the tackifier resin used is within a range of 200 parts by weight or less based on 100 parts by weight of the total of the polypropylene resin (a) and the hydrogenated block copolymer (b).

The resin composition of the present invention may be, for example, a hydrogenated polyisoprene, a hydrogenated polybutadiene, a hydrogenated styrene-butadiene random copolymer, a hydrogenated styrene-polymer within a range that does not impair the spirit of the invention. Isoprene random copolymer, butyl rubber, polyisobutylene, polybutene, ethylene-propylene rubber, polyethylene, ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, ethylene-methacrylic acid copolymer, ethylene-acrylic acid Other polymers such as copolymers or their ionomers, ethylene-ethyl acrylate copolymer, atactic polypropylene can be blended.
Further, the resin composition of the present invention can be used after being crosslinked by a usual crosslinking method using a peroxide or the like, if desired.

The resin composition of the present invention can be prepared by using a kneader such as a single screw extruder, a twin screw extruder, a kneader, a Banbury mixer, and a roll.

The resin composition thus obtained can be formed into a film, sheet, fibrous molded product, or tubular molded product by any molding method such as injection molding, blow molding, press molding, extrusion molding, and calendar molding. Etc.

The resin composition of the present invention gives a molded article having excellent flexibility and excellent transparency. Above all, the transparency is such that when a sheet having a thickness of 1 mm is formed, its haze (Ha
ze) value is 20 or less, which is very excellent. Also,
The resin composition of the present invention gives a molded product having sufficient heat resistance. For this reason, the medical device manufactured using the resin composition of the present invention withstands autoclave sterilization and does not have a problem associated with residual EOG. In addition, sterilization methods such as γ-ray sterilization can be applied to medical devices manufactured using the resin composition of the present invention. Furthermore, the resin composition of the present invention gives a molded product having good biocompatibility. For example, when a catheter made of the resin composition of the present invention is placed in a vein for one week, the amount of blood components such as platelets and fibrin attached to the catheter is smaller than that of a conventional catheter made of soft vinyl chloride or polyurethane. There is little possibility of thrombus development.

The resin composition of the present invention makes use of the above-mentioned properties, for example, catheters such as indwelling catheters and balloon catheters, artificial blood vessels, blood circuits, syringes, and the like.
It is used for medical devices such as artificial dialysis machines, blood component separators, artificial lungs, and wound dressings; sanitary materials such as sanitary products and disposable diapers; and medical products such as surgical clothing and hospital disposable sheets. Among these, the resin composition of the present invention is:
Medical devices used in contact with body fluids, especially blood, such as catheters, blood bags, artificial blood vessels, blood circuits, syringes, hemodialyzers, blood component separators, and artificial lungs, taking advantage of their excellent biocompatibility It is preferably used. Note that not all of these medical devices need to be formed from the resin composition of the present invention, and it is sufficient that at least the portion that comes into contact with bodily fluids is formed from the resin composition of the present invention. For example, in the above-described catheter or blood bag, a portion that comes into contact with a body fluid is formed with the resin composition of the present invention, and a portion that does not come into contact with the body fluid is made of another resin used for medical purposes such as soft vinyl chloride and polyurethane. May be formed. In addition to the above-mentioned medical uses, the resin composition of the present invention can be used in fields requiring excellent flexibility and transparency, such as the field of packaging.

[0038]

The present invention will be described below in detail with reference to examples. The styrene content, number average molecular weight, vinyl bond content and hydrogenation rate of the polymer in the examples, and the mechanical strength, flexibility, transparency and heat resistance of the molded product obtained from the resin composition are as follows, respectively. Was measured according to the method described above.

(Styrene content) Calculated from the weight of each monomer component used in the polymerization. (Number average molecular weight) The number average molecular weight (Mn) in terms of polystyrene was determined by GPC measurement. (Vinyl bond content) The block copolymer before hydrogenation was dissolved in deuterated chloroform (CDCl ₃ ) to give ¹ H-NM.
The R spectrum was measured, and the vinyl bond content was calculated from the size of the peak corresponding to the 1,2-bond or 3,4-bond. (Hydrogenation rate) The iodine value of the block copolymer before and after hydrogenation was measured and calculated from the measured value. (Mechanical strength of molded product) A sheet having a thickness of 1 mm was prepared, a dumbbell-shaped test piece specified in JIS-3 was punched out of the sheet, and a tensile test was performed in accordance with JIS-K6301. Then, the breaking strength (kg / cm ² ) was obtained and used as an index of the mechanical strength. (Flexibility of molded product) Prepare a 1mm thick sheet,
The hardness was measured in accordance with MD-2240 and used as an index of flexibility. (Transparency of molded product) A sheet with a thickness of 1 mm was made
-Haze menu based on the method specified in K7105
The haze value was measured with a tar and used as an index of transparency. (Heat resistance of molded article) A sheet having a thickness of 1 mm was prepared, and the obtained sheet was left in the air at 100 ° C. for 5 hours, and the presence or absence of coloring was visually observed. did.

Reference Examples 1 to 6 (Production of hydrogenated block copolymer) In a dry pressure-resistant container replaced with nitrogen, cyclohexane was used as a solvent, and s-butyllithium was used as a polymerization initiator. After polymerizing styrene, TMEDA was added as a Lewis base, and then isoprene and styrene were polymerized sequentially to obtain a styrene-isoprene-styrene type block copolymer. The obtained block copolymer was prepared in cyclohexane using Pd / C as a catalyst.
Hydrogenation was carried out under a hydrogen atmosphere of 20 kg / cm ² to obtain a hydrogenated block copolymer (hereinafter, the hydrogenated block copolymers obtained in Reference Examples 1 to 6 were each hydrogenated block copolymer 1). ~ 6). Table 1 shows the styrene content, number average molecular weight, vinyl bond content, and hydrogenation rate of the obtained hydrogenated block copolymers 1 to 6.

Reference Examples 7 to 12 (Production of hydrogenated block copolymer) In the same manner as in Reference Examples 1 to 6, s
Styrene, a mixture of isoprene and butadiene [isoprene / butadiene = 60/40 (weight ratio)] and styrene are sequentially polymerized using butyllithium and TMEDA, and styrene- (isoprene / butadiene)-
A styrene type block copolymer was obtained. The hydrogenated block copolymer was obtained by hydrogenating the obtained block copolymer in the same manner as in Reference Examples 1 to 6 (hereinafter, the hydrogenated block copolymer obtained in Reference Examples 7 to 12). The coalescence is abbreviated as hydrogenated block copolymers 7 to 12, respectively). Table 1 shows the styrene content, number average molecular weight, vinyl bond content, and hydrogenation rate of the obtained hydrogenated block copolymers 7 to 12.

Reference Examples 13 to 17 (Production of hydrogenated block copolymer) In the same manner as in Reference Examples 1 to 6, s
Styrene, butadiene and styrene were sequentially polymerized using -butyllithium and TMEDA to obtain a styrene-butadiene-styrene type block copolymer. The obtained block copolymer was hydrogenated in the same manner as in Reference Examples 1 to 6 to obtain a hydrogenated block copolymer (hereinafter, hydrogenated block copolymers obtained in Reference Examples 13 to 17). Each of the coalesced was hydrogenated block copolymer 13 to 17
). Obtained hydrogenated block copolymers 13-1
Table 1 shows the styrene content, number average molecular weight, vinyl bond content, and hydrogenation ratio of No. 7.

[0043]

[Table 1]

Examples 1-3 and Comparative Examples 1-14 Commercially available polypropylene [M
A-3 (trade name), manufactured by Mitsubishi Chemical Corporation] using the hydrogenated block copolymers 1 to 17 obtained in Reference Examples 1 to 17.
And polypropylene resin / hydrogenated block copolymer = 7
0/30 (weight ratio).
The mixture was kneaded at 10 ° C. to obtain a resin composition. The obtained resin composition was press-molded at 210 ° C. into a sheet having a thickness of 1 mm, and the mechanical strength, flexibility, transparency and heat resistance were measured. Table 2 shows the results. The blood compatibility of the resin compositions obtained in Examples 1 to 3 was evaluated as follows. As a result, the number of platelets adhered to the surface of the test piece was 45 / mm ² (resin composition obtained in Example 1) and 53 / mm ² (resin composition obtained in Example 2). And 60 / mm ² (resin composition obtained in Example 3).

Evaluation of Blood Compatibility The resin composition was pressed at 210 ° C. into a sheet having a thickness of 1 mm, and the obtained sheet was cut into a size of 1 cm × 1 cm to prepare a test piece. This test piece was immersed in heparinized whole blood prepared by adding sodium salt of heparin to human blood after blood collection to a concentration of 5 IU / ml at 37 ° C. for 30 minutes. A test piece was taken out of heparinized whole blood, washed with physiological saline, fixed by treating the surface with glutaraldehyde and osmium oxide, and observing the obtained sample using an electron microscope. The number of platelets attached to the surface of the test piece is determined and used as an index of blood compatibility. The lower the number of platelets attached to the surface of the test piece, the better the blood compatibility.

Comparative Example 15 A sheet having a thickness of 1 mm was prepared in the same manner as above using the above polypropylene resin alone, and various physical properties were measured. The results are shown in Table 2.

[0047]

[Table 2]

Examples 4 and 5 Commercially available polypropylene [M
A-3 (trade name, manufactured by Mitsubishi Chemical Corporation)] and the hydrogenated block copolymer 1 obtained in Reference Example 1 and a polypropylene-based resin / hydrogenated block copolymer = 80/20 (Weight ratio) [Example 4] or polypropylene-based resin / hydrogenated block copolymer = 60/40 (weight ratio) [Example 5]
And kneaded at 210 ° C. with a kneader to obtain a resin composition. Each of the obtained resin compositions was prepared in Example 1.
A sheet having a thickness of 1 mm was formed in the same manner as described above, and various physical properties were evaluated. Regarding the resin composition obtained in Example 4, the breaking strength, flexibility and transparency were each 400
kg / cm ² , 52 (hardness according to ASTM D-2240) and 20 (Haze value), no coloring of the sheet was observed, and the number of platelets adhering to the surface of the test piece was 26 / mm ^2. Was. On the other hand, regarding the resin composition obtained in Example 5, the breaking strength, flexibility and transparency were 360 kg / cm ² and 36 (ASTM D, respectively).
Hardness according to -2240) and 12 (Haze value), no coloring of the sheet was observed, and the number of platelets adhered to the surface of the test piece was 55 / mm ² .

Comparative Example 16 A test piece prepared by cutting a soft vinyl chloride sheet having a thickness of 1 mm into a size of 1 cm × 1 cm was used, and the blood compatibility was evaluated in the same manner as described above. The number of platelets adhered to was 80 / mm ² .

Examples 6 to 10 A catheter (length: 30 cm, outer diameter: 0.8 mm, inner diameter: 0.6 mm) was formed by extruding the resin composition obtained in Examples 1 to 5 into a tube. Produced. The obtained catheter is subjected to autoclave sterilization (121 ° C., 20
), No change in shape or reduction in strength (rupture strength when pulled in the length direction) was observed before and after sterilization. Each of the catheters obtained above was inserted into a rabbit jugular vein and left for 7 days. At this time, the inside of the catheter was filled with physiological saline, and the end outside the body from the vein was sealed. The catheter was removed from the rabbit jugular vein, washed with saline, fixed by treating the surface with glutaraldehyde and osmium oxide, and observing the outer surface of the catheter visually and with an electron microscope. As a result, 5% of the outer surface of the catheter (Example 6: Example 1)
Catheter obtained from the resin composition of Example 2), 8% (Example 7: catheter obtained from the resin composition of Example 2),
7% (Example 8: catheter obtained from the resin composition of Example 3), 4% (Example 9: catheter obtained from the resin composition of Example 4) and 7% (Example 10: performed Adhesion of fibrin and platelets to the catheter obtained from the resin composition of Example 5) was observed.

Comparative Example 17 A soft vinyl chloride catheter (commercial product, manufactured by Nippon Sherwood Co., Ltd., length: 30 cm, outer diameter: 0.8 mm) was inserted into the rabbit jugular vein for 7 days in the same manner as in Example 6. Detained. The catheter was removed from the rabbit jugular vein, washed with saline, fixed by treating the surface with glutaraldehyde and osmium oxide, and observing the outer surface of the catheter visually and with an electron microscope. As a result, adhesion of fibrin and platelets was observed on about 30% of the outer surface of the catheter.

Comparative Example 18 A polyurethane catheter (commercial product, manufactured by Terumo Corporation, length: 30 cm, outer diameter: 0.8 mm) was inserted into the rabbit jugular vein in the same manner as in Example 6 and left for 7 days. The catheter was removed from the rabbit jugular vein, washed with saline, fixed with glutaraldehyde and osmium oxide, and the outer surface of the catheter was observed with the naked eye and an electron microscope. As a result, attachment of fibrin and platelets was observed on about 40% of the outer surface of the catheter.

Examples 11 and 12 Bags (size: 15 cm × 10 cm, thickness: 0.5 mm) were prepared by extruding the resin composition obtained in Example 4 or 5 by inflation. A platelet concentrate prepared so that the concentration of platelets becomes 5 units is placed in the obtained bag.
Shake for 2 hours. When the platelet concentrate was removed from the bag and its platelet aggregation ability was measured, the platelet aggregation ability at the time of adding collagen was 50% when placed in a bag made of any of the resin compositions and shaken. Had good coagulation ability. From this, Example 4
Or it turns out that the bag made of the resin composition obtained in 5 has good blood compatibility.

The above Examples 1 to 12 and Comparative Examples 1 to 1
As is clear from FIG. 8, the resin composition of the present invention gives a molded article having excellent flexibility and transparency, and sufficient mechanical strength and heat resistance. The medical device such as a catheter and a blood bag obtained from the resin composition of the present invention can be subjected to an autoclave sterilization treatment, and has good biocompatibility, especially blood compatibility.

[0055]

According to the present invention, there is provided a resin composition which is excellent in flexibility and transparency and gives a molded article having sufficient heat resistance. The resin composition of the present invention is useful in fields where excellent flexibility and transparency are required, and is particularly suitably used in the medical field. In addition, the resin composition of the present invention provides a molded product having good biocompatibility, especially good blood compatibility, so that catheters, blood bags, artificial blood vessels, blood circuits, syringes, hemodialyzers,
It is suitable for the production of medical devices used in contact with body fluids, such as blood component separators and artificial lungs.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Nobuyuki Utagawa 1621 Sakurazu, Kurashiki-shi, Okayama Prefecture Inside Kuraray Co., Ltd.

Claims (4)

[Claims] 1. A polypropylene resin (a), (b-1) at least one polymer block A comprising a vinyl aromatic compound, and a content of 1,2- and 3,4-bonds of 10 or more. Having at least one polyisoprene block B having a vinyl aromatic compound content of 10 to 75 mol%.
(B-2) a polymer block composed of a vinyl aromatic compound, wherein the hydrogenated block copolymer is a hydrogenated block copolymer having a hydrogen content of at least 40% by weight and at least 70% of carbon-carbon double bonds of polyisoprene block B are hydrogenated. A or more, and isoprene and butadiene in 5/9
It is composed of a mixture of polymers mixed at a weight ratio of 5 to 95/5, and the content of 1,2-bond and 3,4-bond is 20 to
Having at least one polymer block C of 85 mol%, the content of the vinyl aromatic compound is 10 to 40% by weight,
And a hydrogenated block copolymer obtained by hydrogenating 70% or more of the carbon-carbon double bonds of the polymer block C; and (b-3) one or more polymer blocks A comprising a vinyl aromatic compound; And at least one polybutadiene block D having a 1,2-bond content of 45 mol% or more, a vinyl aromatic compound content of 10 to 40% by weight, and a carbon-carbon of the polybutadiene block D. It is composed of at least one hydrogenated block copolymer (b) selected from the group consisting of hydrogenated block copolymers in which 70% or more of the double bonds are hydrogenated, and the proportion of both hydrogenated block copolymers is polypropylene-based resin (a ) / Hydrogenated block copolymer (b) = 1
A resin composition having a ratio of 0/90 to 90/10 (weight ratio). 2. A medical device wherein at least a portion in contact with a bodily fluid is formed from the resin composition according to claim 1. 3. The medical device according to claim 2, wherein the body fluid is blood. 4. The medical device according to claim 2, which is a catheter, a blood circuit or a blood bag.