JPH0871143A - Production of medical tube with surface treatment for hydrophilicity and medical tube - Google Patents

Abstract

PURPOSE: To improve the continuance of lubricating property of the tube surface and improve the storage property by irradiating the part of a polyolefin resin medical tube where hydrophilicity treatment is to be applied with a specified dose of radiation in an inert gas atmosphere and then effecting graft reaction under specified conditions using graft monomers. CONSTITUTION: The part of a polyolefin resin medical tube where the treatment for hydrophilicity is to be applied is irradiated with radiation corresponding to 10 to 70 Mrad in an inert gas atmosphere. Then the graft reaction is effected using grafting monomers under conditions of <=70 deg.C graft reaction temp., >=20wt.% monomer density in the graft liquid, and <=100ppm oxygen density in the graft reaction system. The grafted chains formed on the surface of the tube are selected from monomers of acrylamidemethacrylamide, vinyl-modified rings, acrylate-methacylate, acrylic acid, mathacrylic acid, or ester of these, and vinyl ether.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical tube having a hydrophilic surface, which is inserted into a body cavity for use and a method for producing the same.

[0002]

2. Description of the Related Art Medical devices such as blood vessels, ureters, digestive tracts, trachea, and other medical cavities inserted into body cavities or body tissues, such as guide wires and stylets, are used in cases of flexion, stenosis, and even more peripheral cases. In this regard, there is an increasing demand for lubricity that allows the target site to be reliably reached without damaging the tissue. Further, it goes without saying that it is desirable to impart excellent lubricity for the purpose of preventing mucosal damage and inflammation during indwelling in the tissue.

For the purpose of imparting this lubricity, it is practiced to use a low friction resistance material formed of a fluororesin or a polyethylene resin or to form a lubricating layer made of a fluororesin or a silicone resin on the surface of a base material. Has been done. Further, surface coating of silicone oil, olive oil, glycerin, xylocaine jelly and the like is already known.

Each of the above methods involves various problems that need further improvement. That is, a low friction resistance material obtained from a fluororesin or a polyethylene resin is often not sufficient in terms of lubricity. On the other hand, in the surface coating method of oils, deterioration of lubricity due to the outflow of the coating liquid is apt to occur,
It is obvious that there are problems with sustainability.

Further, in US Pat. No. 4,100,309, an interpolymer of polyvinylpyrrolidone and polyurethane is used as a coating layer to obtain a certain effect on lubricity and durability. However, it is necessary to use a base material capable of reacting with an isocyanate group such as polyurethane, and it has been difficult to apply it to other base materials such as a polyolefin resin useful as a base material for medical tubes.

Further, Japanese Patent Laid-Open No. 59-81341 discloses a method in which an unreacted isocyanate group is formed on the surface of a medical device and then treated with a hydrophilic copolymer capable of reacting with it to perform a hydrophilic treatment. It is disclosed. Although lubricity and a certain degree of sustainability have been obtained by this treatment method, damage to the surface lubricating layer due to repeated friction cannot be ignored, and sufficient sustainability has not yet been obtained.

From these points, there is a demand for a hydrophilic treatment which is useful for the hydrophilic treatment of polyolefin resin and has a high durability. As a concrete method of such hydrophilic treatment, application of a plasma graft method in a gas phase is considered.
However, medical tubes made of polyolefin resins are often stretched or shaped at the stage of their processing, and depending on the processing temperature when the plasma graft method is applied, heat shrinkage or deformation may occur, There is a possibility that dimensional stability and strength may be adversely affected.

[0008]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a medical tubing of a polyolefin resin, which is used in a wet state of body fluids such as blood, digestive juices, saliva and physiological saline, and aqueous fluids such as water. It is an object of the present invention to provide a medical tube having a low frictional resistance during insertion, and having excellent surface lubricity sustainability and storability, and a method for producing the same.

As a typical example of a medical tube, PT
With the CA dilatation catheter, the surface of the catheter shaft / balloon is hydrophilized to maintain the flexibility of the conventional polyolefin-based catheter balloon / shaft, while maintaining a flexible and highly constricted blood vessel. It is intended to improve the running performance of the car.

[0010]

SUMMARY OF THE INVENTION In order to solve the above technical problems, the present invention does not apply a fixed dose of radiation to at least a portion of the surface of a medical treatment tube made of a polyolefin resin to which hydrophilic treatment is applied. The surface of the medical tube is hydrophilized by irradiating under an active gas atmosphere and then using a graft monomer to cause a graft reaction under specific conditions.

[0011]

Basic Process of the Invention The basic constitution of the present invention is summarized as follows: Radiation irradiation process 10 Mrad to 70 at least on the surface of the surface of the medical tube made of polyolefin resin to be subjected to the hydrophilic treatment.
Radiation equivalent to Mrad is applied in an inert gas atmosphere.

Grafting reaction step Next, using a grafting monomer, a grafting reaction is carried out under the following conditions to obtain a surface-hydrophilized medical tube: grafting reaction temperature ≤ 70 ° C monomer concentration in grafting liquid ≥ 20% by weight Oxygen concentration in graft reaction system ≤ 100ppm

[0013]

DETAILED DESCRIPTION OF THE INVENTION Here, a medical tube applicable to the present invention will be exemplified.

Outer surface or inner surface of catheters for intravascular insertion or indwelling such as angiography catheters, cerebrovascular treatment catheters, dilators, introducers, thermodilution catheters, IVH catheters, indwelling needles and the like. Alternatively, the outer surface of the dilator or introducer for these catheters. By subjecting the above-mentioned tube or the like to the hydrophilic treatment of the present invention, the insertion resistance of the catheter into the blood vessel can be reduced, so that the coronary insertion resistance of the guide wire can be reduced.

Part or all of the outer or inner surface of various balloon catheters, catheters such as urethral / urethral catheters, and balloons. By subjecting the above-mentioned tube or the like to the hydrophilic treatment of the present invention, the frictional resistance can be reduced, so that the tube can be easily inserted, and it can reach the periphery and exceed the bent portion.

Outer or inner surface of catheters such as a gastric tube catheter, feeding catheter, tube feeding tube orally or nasally inserted or left in the digestive tract. By subjecting the above-mentioned tube or the like to the hydrophilic treatment of the present invention, the resistance of catheters to be inserted into the tube is reduced, and the swallowing of the patient himself / herself becomes easy.

Outer or inner surface of catheters to be placed upon oral or nasal insertion of endotracheal tube, oxygen catheter, tube / cuff of oxygen canula, endotracheal suction catheter, etc.

Outer or inner surface of catheters for placement in various body cavities or tissues such as suction catheters, drainage catheters, rectal catheters. By applying the hydrophilic treatment of the present invention to the above-mentioned tube or the like, adhesion of tissue fluid or the like is reduced and the lumen flow path can be secured for a long period of time.

The outer surface of the endoscope tube for insertion into various body cavities.

In addition, the inner / outer / outer surface or inner surface of a medical device which requires low frictional resistance (lubricity) during indwelling or sliding in the body.

A PTCA dilatation catheter can be mentioned as one of the medical tubes to which the hydrophilization treatment of the present invention is particularly preferably applied. As is well known, the technique of percutaneously inserting / expanding a catheter into a blood vessel is generally performed to treat a lesion involving a blood vessel, and when performing such a vasodilation, a guiding catheter is used. -Expansion catheters and guide wires are commonly used. Typical examples of conventional balloon manufacturing methods used for this balloon catheter are U.S. Pat. Nos. 4,093,484 and 4,154,244.
And No. 4254774. Balloons can be made from various known polymeric materials that are generally thermoplastic. Among the known polymer materials described in the above patents, polyurethane; polyvinyl chloride; thermoplastic elastomer; silicon carbonate copolymer; ethylene.
Vinyl acetate copolymer; ethylene-butylene-styrene block copolymer; polystyrene; acrylonitrile copolymer; various polyolefins such as polyethylene and polypropylene; polyethylene terephthalate and polyester copolymer; thermoplastic rubber; polyamide; polytetrafluoroethylene.

Among these, the balloon portion of the catheter used for dilatation is required to have various characteristics depending on the state of the lesion, but a common requirement is to improve the safety of the balloon catheter. Therefore, it is required to have a high breakdown voltage.

Further, in the procedure of applying to a blood vessel with more advanced stenosis, there is also a demand for a balloon that is flexible, has excellent running properties, and is highly safe. The term "blood vessel" used in the present invention is meant to include not only coronary blood vessels but also all blood vessels including coronary blood vessels, such as peripheral blood vessels.

As for the performance and function of the balloon portion of such a catheter, various characteristics are required as described above depending on the state of the lesion. Polyethylene terephthalate type balloons are generally useful as balloons having high pressure resistance and no compliance or small size (eg, Japanese Examined Patent Publication No. 63-2665).
No. 5). However, this type of balloon is too stiff to be used for dilating a blood vessel with flexion and severe stenosis, and cannot exhibit sufficient trackability. Further, a polyamide (nylon) -based balloon can provide a balloon that is semi-compliant and has a relatively high pressure resistance as compared with a polyolefin (eg, Japanese Patent Laid-Open No. 3-57462, etc.), but it is still extremely bent. It has been pointed out that it tends to be slightly stiff when applied to highly stenotic blood vessels and more peripheral blood vessels.

Therefore, in this percutaneous angioplasty,
In the case of application to a blood vessel thinner than a peripheral blood vessel, there is an increasing demand for a dilatation catheter having a flexible tip portion including a balloon portion, and in this sense, a polyolefin balloon is considered to be suitable. In a flexible and relatively high-pressure balloon-loaded dilatation catheter obtained by suitable resin selection and suitable balloon molding, part or all of the shaft / balloon may be subjected to a hydrophilic treatment by a radiation graft reaction. Conceivable. By carrying out hydrophilic treatment of the shaft / balloon under relatively mild graft conditions, thermal contraction and deformation do not substantially occur, and by imparting hydrophilicity, a balloon catheter having excellent intravascular running property is obtained. Can be provided.

Base Material Resin The polymer material used as the base material of the medical tube of the present invention is a polyolefin resin. Typical examples of such resins include various polyethylene / polypropylene and their copolymers, olefinic elastomers, ethylene / vinyl acetate copolymers, ethylene / butylene / styrene / block copolymers, polystyrene, acrylonitrile copolymers, and various diene polymers. Is mentioned.

As a preferable resin, a copolymer of ethylene and α-olefin can be mentioned, and various kinds of α-olefins to be copolymerized are known, but the preferable α-olefin in the present invention has 3 or more carbon atoms. Those having 4 or more carbon atoms, and particularly preferably 6 carbon atoms.

An example of making a medical tube using the above materials will be described below.

First, an original tube (for blow molding) having a predesigned dimension is molded. The tube molding method can be manufactured by an extrusion molding method, a copper wire coating method including a step of coating a metal wire with a resin, and then removing a copper wire serving as an inner core. The hollow extrusion method can also be preferably applied.

In extruding the original tube, cooling of the extruded tube immediately after being discharged from the die is an important requirement for blow moldability, and suitable cooling temperature conditions are set in accordance with the characteristics of the polymer material.

Water is generally used as a cooling medium, but when a lower temperature is required, a cooling medium may be used in place of the cooling water to cool the medium to 0 ° C. or lower, if necessary. I have something to do.

In the original tube extrusion molding of the present invention, it is possible to manufacture an original tube having a multilayer structure by carrying out multilayer extrusion, or by carrying out multilayer coating also in the copper wire coating method. it can.

The resin of each layer constituting the multi-layer structure can be selected from the group consisting of the same or different resin material as the resin of the other layers.

In selecting the resin, it is required that the resin of the present invention and the original tube can be formed and blow-molded together.

Such a multilayer structure can be utilized to further enhance the effects of the present invention such as improvement of surface characteristics, improvement of releasability during blow molding, and increase of strength.

In some cases, it is preferable to use a polyethylene medical tube that has been crosslinked by radiation such as an electron beam, rather than an uncrosslinked tube. Therefore, radiation treatment can be applied by utilizing radiation crosslinking, but radiation irradiation may be performed independently or in common with such radiation crosslinking for other purposes, and it can be classified as follows: Embodiment 1: Hydrophilicity Radiation irradiation graft reaction for crosslinking treatment (simultaneous generation of cross-linking structure) Embodiment 2: Radiation irradiation for cross-linking purpose → hydrophilization Radiation irradiation graft reaction for purpose of hydrophilic treatment Embodiment 3: Common purpose radiation irradiation (simultaneous generation of cross-linking structure) → hydrophilicity Radiation irradiation graft reaction for chemical treatment As an application example of the crosslinked tube thus prepared,
There is the balloon portion of the PTCA dilatation catheter. By subjecting the shaft tube including a part or all of the balloon portion of the catheter to the surface hydrophilic treatment, the hydrophilic property of the shaft / balloon in addition to the flexibility inherent to the above-mentioned polyolefin provides two effects. Due to the synergistic effect of (1), it is expected that the running property in a blood vessel that is bent and highly stenotic can be significantly improved. The medical tube for balloon molding will be described in detail below.

It is known that a crosslinked tube obtained by irradiation with an electron beam having a specific dose exhibits suitable blow moldability. In general, in the formation of a crosslinked structure by electron beam irradiation, the irradiation atmosphere is also related to the dose. It is also affected by the molecular structure (particularly the degree of branching) of the resin to be irradiated and the shape and size of the member.

In view of the above, in the present invention, the preferable range of crosslinking is explained by the gel fraction used as one of the indexes of the degree of crosslinking among experts in the art.

In the present invention, the gel fraction of the electron beam crosslinked tube evaluated by a known measuring method is preferably 0.75 to 0.95. If it is less than 0.75, the improvement of the stretching characteristics and the burst pressure by electron beam irradiation are insufficient. On the other hand, when it exceeds 0.95, the crosslinked structure becomes too strong,
Flexibility is often compromised. The range of the gel fraction is more preferably 0.80 to 0.92, and particularly preferably 0.82 to 0.90. Note that irradiation time is generally extremely long by γ-ray irradiation instead of electron beam irradiation, but it is theoretically possible to generate a crosslinked structure.

Monomers (including oligomers) used to form the lubricious graft chains of the medical tubing of the present invention
Examples of acrylamide / methacrylamide dialkyl acrylamides (dimethyl acrylamide, diethyl acrylamide, methyl ethyl acrylamide, diisopropyl acrylamide, etc.), monoalkyl acrylamides (methyl acrylamide, ethyl acrylamide, isopropyl acrylamide, etc.), and other acrylamides (2-methylpropane sulfonic acid acrylamide, dimethylaminopropyl acrylamide, etc.), acrylamide, and each methacrylamide of the corresponding chemical structure Vinyl heterocyclic ring system Vinyl pyridines (2-vinyl pyridine, 4-vinyl pyridine, etc.), Vinylpyrrolidone, N-1,2,4-triazolylethylene, etc. Acrylate / methacrylate polyalkylene glycol Acrylates (glyceryl acrylate, etc.), hydroxyalkylene acrylates (hydroxyethyl acrylate, hydroxypropyl acrylate, etc.), and corresponding methacrylates of the chemical structure acrylic acid and its salt system acrylic acid, methacrylic acid and their Metal salts, etc. Vinyl ether type In combination with maleic anhydride-vinyl ether, vinyl ether, and the above graft monomers, various vinyl compounds can be used in order to improve the properties of the lubricating layer according to the purpose.

Next, the radiation irradiation step will be described. In the radiation graft technique, a simultaneous irradiation method in the presence of a monomer and a pre-irradiation method in which generation of reaction active points (radicals) and graft reaction are separately performed are known.

In the simultaneous irradiation method, in addition to homopolymerization (formation of homopolymer) of coexisting monomers simultaneously,
In the case of a liquid phase reaction, the properties of the reaction system may change with time such that the liquid viscosity of the reaction system increases, and a uniform graft layer may not be obtained, which is not preferable. On the other hand, in the pre-irradiation method adopted in the present invention, process factors such as temperature, time, pressure and capacity can be set independently of the subsequent graft reaction step, and the irradiation method has a high degree of freedom.

In the present invention, the first step is to irradiate at least a portion of the surface of the medical treatment tube made of a polyolefin resin, which is subjected to a hydrophilic treatment, with a radiation of 10 Mrad to 70 Mrad in an inert gas atmosphere. As necessary. Taking an electron beam as an example of radiation, when the dose of radiation is less than 10 Mrad, the effect of the graft reaction is small and sufficient lubricity cannot be obtained. On the other hand, if it exceeds 70 Mrad, the cross-linking density may be high, so that the workability and assemblability of the catheter may be poor, and in extreme cases, defects such as deformation during the sterilization process may occur. A preferred radiation dose is 15 Mrad to 60 Mrad
And particularly preferably 20 Mrad to 50 Mrad.

In the present invention, the intensity of the radiation source can be adjusted for the purpose of controlling the characteristics of the graft layer. That is, when it is desired to limit the graft layer to the vicinity of the surface, the intensity of the radiation source is slightly lowered, while, for example, when it is desired to express the graft effect to a considerable depth by the electron beam irradiation method, the acceleration voltage is increased. Can be taken as needed.

In the present invention, the atmosphere during radiation irradiation is an inert gas atmosphere. Typical examples of the inert gas are nitrogen, argon, neon, helium, and mixed expectation thereof. When irradiation is performed in an atmosphere such as air, it is often necessary to carry out the graft reaction immediately immediately after irradiation. On the other hand, in an inert gas atmosphere, active points such as radicals generated by irradiation of radiation work effectively, and the graft reaction in the next step proceeds smoothly. When a long time elapses before the graft reaction after irradiation with radiation, low-temperature storage is generally performed in order to preserve active sites such as radicals. The radiation irradiation temperature is preferably 70 ° C. or lower at which the polyolefin resin of the present invention does not cause undesired deformation.

Next, the graft reaction step will be described.

The medical tube irradiated with radiation is immersed in a graft solution and a graft reaction is carried out under the following conditions: Graft reaction temperature ≦ 70 ° C. Monomer concentration in graft solution ≧ 20% by weight Oxygen concentration in graft reaction system ≦ When the 100 ppm graft reaction temperature exceeds 70 ° C., the polyolefin-based tube of the present invention often causes inconvenient deformation. Since the graft reaction rate is affected by temperature, it is preferably 10 ° C or higher, more preferably 20 ° C or higher.

In the present invention, the concentration of the monomer in the graft liquid is 20% by weight or more. If it is less than 20% by weight, the lubricity is often poorly expressed by the graft reaction. In the present invention, the graft reaction step can be carried out in the liquid phase or the gas phase. In the case of liquid phase graft, various solvents other than water and alcohol can be used as the diluting solvent. In particular, the thickness of the graft layer and the anchoring distance from the base material interface can be controlled by appropriately selecting the base material-solvent swelling property.

The oxygen concentration in the graft reaction system is 100 p.
pm or less is preferable. Needless to say, the permissible oxygen concentration that exhibits sufficient lubricity varies depending on the type of the graft monomer, but it is preferably 50 ppm or less, particularly preferably 20 ppm or less. If the oxygen concentration exceeds 100 ppm, the growth of graft chains may be insufficient, or undesirable side effects may occur, which is not preferable.

The hydrophilic treatment of the medical tube can be carried out at any stage of the original tube immediately after extrusion, after assembling into a catheter, or at an intermediate stage therebetween. As an example, while showing the manufacturing process of the PTCA dilatation catheter, the timing of performing the hydrophilic treatment on both the shaft and the balloon will be exemplified below: Process The original tube is molded by a hollow extrusion method and an electric wire coating method using a polyolefin resin.

The process tube is irradiated with radiation to form a crosslinked tube.

Blow molding the cross-linked tube,
Create a Hara balloon. Process of preparing shaft tube PTC using raw balloon and shaft tube
Assemble the A dilatation catheter.

Process A hydrophilic PTCA dilatation catheter is prepared.

As described above, the PTCA dilatation catheter is roughly made in four stages. The timing of performing the hydrophilic treatment is as follows: a step-step, b step-step,
It can be performed between step c and step. At timing a, only the balloon is hydrophilized, and the shaft tube must be hydrophilized at a later timing.
At timings b and c, both the balloon and the shaft tube can be hydrophilized. However, at timing b, the balloon and the shaft tube need to be respectively hydrophilized, but at timing c, since the hydrophilic treatment of the balloon and the shaft tube can be performed at one time, c is the most suitable timing. It can be said that it is preferable.

Specific examples of the present invention will be described below.

[0056]

Examples 1 to 4 and Comparative Examples 1 to 4 Low-density polyethylene (C6 LLDPE resin: Nipolon-Z manufactured by Tosoh Corporation, melt flow rate = 1.0 g / 10 min, specific gravity of 0.
The pellet of 92) was melted by an extruder and coated on a copper wire having a diameter of 0.5 mm. The diameter of the coated electric wire was 0.940 mm. Therefore, the thickness of the (coated) original tube is 2
This corresponds to 20 μm. An inner copper wire was removed from the resin-coated copper wire to prepare an original tube.

An electron beam was applied to the above-mentioned original tube at an irradiation dose of 30 Mr.
Irradiated under a nitrogen atmosphere with ad. Here, the purpose is to crosslink the original tube and at the same time to develop the starting point of radicals.

Dimethyl acrylamide was used as a graft monomer and water was used as a solvent (oxygen concentration in water was 5 ppm) in the original tube, and the monomer concentration was changed to 5
Table 1 shows the lubricity of the hydrophilized original tube after the graft reaction at 0 ° C.

[0059]

[Table 1]

[0060]

Example 5 In the same manner as in Example 1, vinylpyrrolidone was used as a monomer for hydrophilic treatment.
However, the concentration of the monomer aqueous solution was 30% by weight, and the grafting time was 2 hours. The resulting tube showed good lubricity.

[0061]

[Example 6] "Assembly of PTCA dilatation catheter" Using the electron-beam-irradiated dimethylacrylamide-grafted medical tube used in Example 1, blow molding in a constant temperature range gives a balloon-shaped shape. it can. For the blow molding using the extruded original tube, for example, the method described in JP-B-63-26655 can be used. Also in this embodiment, the above tube is inserted into a balloon molding die having a cavity having a desired outer diameter dimension and set in a balloon molding machine. Next, the temperature is raised to an appropriate temperature and then stretched in the machine direction.

In order to expand and shape the once stretched tube in the blow molding machine, an arbitrary gas, for example, a gas such as nitrogen can be used. Blow molding using heated gas or the like is also applicable. The above-mentioned longitudinal stretching step and blowing step can be carried out continuously in the same mold, and the temperatures of both steps can be set to the same level. By performing the above-described longitudinal stretching step to blowing step in multiple stages, a high pressure resistant balloon with less uneven thickness can be manufactured. A balloon was prepared by applying a blow molding machine for balloon molding and longitudinally stretching and blow molding at 105 ° C. The test of the balloon alone showed flexibility and relatively high pressure resistance (14 to 16 atm).

After thinning the joint portion of the balloon with the shaft, the joint portion on the distal end side of the balloon is joined with the inner pipe shaft made of polyolefin and the joint portion at the base side is joined with the outer pipe shaft made of polyolefin, and the hub is joined to the base portion. , A PTCA dilatation catheter with a flexible tip and good operability was assembled.

Even after the PTCA dilatation catheter was assembled, the balloon portion showed good lubricity when wet.

[0065]

[Example 7] A balloon was prepared in the same manner as in Example 6 except that a base tube made of a polyolefin resin that had not been subjected to a hydrophilization treatment was used, and then the joint portion of the balloon and the shaft was thinned. The balloon distal end joint was joined to the polyolefin inner tube shaft, the base side joint was joined to the polyolefin outer tube shaft, and the hub was joined to the base to assemble a good PTCA dilatation catheter with a flexible tip.

This assembled PTCA dilatation catheter was irradiated with an electron beam (irradiation dose 25 Mrad) in a nitrogen atmosphere. However, the hub and the base end portion were covered with a shielding member so as not to be irradiated with an electron beam.

Next, dimethylacrylamide was used as a graft monomer (solvent: water, monomer concentration: 35% by weight, grafting time: 2 hours, temperature: 50 ° C., oxygen concentration: 8 pp.
m) and the graft reaction was carried out.

After completion of the reaction, the slidability was confirmed, and not only the balloon but also the shaft showed good lubricity. Also, there is no deformation or contraction of the balloon or shaft,
There was no loss of flexibility. Further, since the base end portion and the hub that were not irradiated with the electron beam were not hydrophilized, they had no lubricity, and therefore the operability was not deteriorated by slippage and the operability was good.

[0069]

INDUSTRIAL APPLICABILITY The present invention is to irradiate at least a portion of a surface of a medical treatment tube made of a polyolefin resin, which is subjected to a hydrophilization treatment, with a predetermined amount of radiation in an inert gas atmosphere, and then to a graft solution under predetermined conditions. Since it is a method for producing a medical tube that is surface-hydrophilized by dipping and performing a graft reaction, it does not impair the flexibility of the base material made of a polyolefin resin, does not cause deformation or heat shrinkage, and is almost It has no effect. The balloon of the present invention made of a polyolefin resin starts from a flexible polymer material, and by delicately controlling the steps from balloon molding and post-treatment, while maintaining the flexibility peculiar to polyolefin, a surface hydrophilic treatment is performed. Since excellent lubricity is imparted, an extremely useful medical tube can be provided.

Further, according to the present invention, since a hydrophilic graft chain is formed on the surface of a tube made of a polyolefin resin to make it hydrophilic, a highly durable lubricity is imparted. Even if it is placed in the body cavity for a long time, the slidability is not deteriorated, and very good operability can be maintained.

Claims (3)

[Claims] 1. A medical treatment tube made of a polyolefin-based resin is provided with 10M on at least a portion to be subjected to a hydrophilic treatment on the surface thereof.
A method for producing a medical tube having a surface-hydrophilized treatment, which comprises irradiating a radiation equivalent to rad to 70 Mrad in an inert gas atmosphere, and then performing a graft reaction using a graft monomer under the following conditions. Grafting temperature ≤ 70 ° C Grafting monomer concentration ≥ 20% by weight Oxygen concentration in grafting system ≤ 100 ppm 2. A surface-hydrophilized medical tube characterized in that a hydrophilic graft chain is formed on the surface of a tube made of a polyolefin resin produced by the production method according to claim 1. . 3. A monomer in which the graft chain is selected from the group consisting of acrylamide / methacrylamide type, vinyl heterocyclic ring type, acrylate / methacrylate type, acrylic acid / methacrylic acid / and its salt type, and vinyl ether type. The medical tube according to claim 2, wherein the medical tube comprises: