JP2000254235A - Medical tube and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a medical tube having pushing ability, tracking ability, torque transmissivity and kink resistance and tip flexibility. SOLUTION: A medical tube 1 has a lumen formed inside, a soft synthetic resin inner layer and an outer layer formed of harder material than inner layer forming material to cover the outer face of the inner layer. In the medical tube 1, the inner and outer layers have different thickness ratios between the tip 6 and base end 8, the outer layer being thin at the tip 6 and thick at the base end 8. Further, the tip 6 of the medical tube 1 is provided with a groove 9 extending from the outer face of the outer layer to the direction of the lumen and having a depth, not reaching the lumen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medical tube used for a blood vessel catheter, an ultrasonic catheter, an endoscope, and the like.

[0002]

2. Description of the Related Art In recent years, medical tubes have become highly functional. Medical tubes with advanced functions include, for example, balloon catheters for vascular dilatation used in percutaneous angioplasty to dilate stenosis in blood vessels, aneurysms and arteriovenous malformations found in cerebral blood vessels Cerebral vascular catheter for injecting embolic material and coil for etc., ultrasonic catheter for precise observation and diagnosis of blood vessels using ultrasonic diagnostic equipment,
It is used for endoscopes and the like that enable precise observation and diagnosis of blood vessels, bile ducts, pancreatic ducts, and the like using an image diagnostic device.

[0003] Such a high-performance catheter is required to be operable and durable so that it can be quickly and reliably inserted into a thin and complicated blood vessel. Specifically, the operator easily pushes the catheter in order to penetrate the blood vessel (pushability), and proceeds smoothly in a complicated meandering blood vessel along a guide wire inserted in advance without damaging the blood vessel inner wall. Things (trackability),
The rotational force transmitted at the proximal end of the catheter tube is reliably transmitted to the distal end (torque transmission), and it is difficult to kink (bend) during handling before operation or pushing the catheter. The kink does not occur in the catheter at the bend of the blood vessel even after the catheter tip reaches the part to be taken and the guide wire is pulled out (kink resistance), and furthermore, to reduce the physical and mental burden on the patient In order to reduce the size of the guiding catheter that guides the catheter to the target site, and to reduce the frictional resistance with the blood vessel wall, the outer diameter of the tube should be as thin as possible (low-profile property), Less damage (flexibility at the tip) is required.

[0004] As described above, high-performance catheter tubes are required to have not only thinness and torque transmitting properties but also contradictory characteristics such as hardness and softness, thinness and difficulty in breaking.
It is also required that the tube be partially stiff. In order to manufacture a catheter tube that satisfies these required characteristics, various technical developments have conventionally been made.

[0005] For example, there is one disclosed in Japanese Patent Application Laid-Open No. 6-319803. The catheter disclosed therein is characterized in that a hardness adjusting tube provided with a cut or groove whose density becomes higher as approaching the distal end portion is disposed in the catheter tube.

[0006]

However, when a hardness adjusting tube having a cut is used in, for example, a vascular dilatation balloon catheter or a drug solution administration catheter, a coating layer is formed so that fluid does not leak from the cut. Therefore, when the inner diameter of the catheter is defined, the outer diameter becomes large, which is disadvantageous with respect to the above low profile property.

[0007] Regarding the groove processing, the hardness adjusting tube is preferably made of a hard material in order to improve the pushability at the base end side. However, since the tube structure is a single layer, a groove with high density is formed at the distal end. Even if formed, it is difficult to ensure the flexibility necessary for operability in practical use,
It is disadvantageous in terms of trackability and advanced flexibility.

An object of the present invention is to provide a small-diameter medical tube having good pushability, trackability, and flexibility at the tip, as well as good torque transmission and kink resistance.

A first object of the present invention is to provide a medical tube having flexibility at the tip as well as pushability, trackability, torque transmission and kink resistance.

[0010] A second object of the present invention is to provide a method for manufacturing a medical tube capable of reliably manufacturing the above-mentioned medical tube.

[0011]

The first object of the present invention is achieved by forming a lumen formed inside, an inner layer made of a soft synthetic resin, and forming an inner layer while covering the outer surface of the inner layer. A medical device comprising an outer layer formed of a material harder than the material to be treated, wherein the thickness ratio of the inner layer to the outer layer on the distal side of the medical tube is the thickness on the proximal end side of the medical tube. The thickness is greater than the thickness ratio of the inner layer to the outer layer, and the medical tube further has a groove at a distal end extending from the outer surface of the outer layer in the lumen direction and having a depth not reaching the lumen. It is a medical tube characterized by the above-mentioned.

Preferably, the inner layer is thicker than the outer layer on the distal end side of the medical tube, and the outer layer is thicker than the inner layer on the proximal end side of the medical tube. Further, it is preferable that the bottom surface of the groove has a rounded shape. Further, it is preferable that the groove has a spiral shape. Furthermore, it is preferable that the pitch of the groove is smaller at the distal end side than at the proximal end side of the tube. Further, it is preferable that at least a part of the bottom portion of the groove of the medical tube extends from the surface of the outer layer to the inner layer over the longitudinal direction of the medical tube. Further, the medical tube may be a catheter.

A second object of the present invention is to provide an inner layer made of a soft synthetic resin and an outer layer made of a material harder than the soft synthetic resin. Providing a tubular body having a ratio greater than the wall thickness ratio of the inner layer to the outer layer at the proximal end; and processing the surface of the tubular body to provide at least one over the longitudinal direction of the tubular body. Forming a groove having a depth not reaching the inner layer from the outer layer surface at the groove bottom portion, and not reaching the inner lumen of the medical tube. is there.

Preferably, the step of preparing the tubular body is performed by co-extrusion while changing the discharge amounts of the inner layer forming resin and the outer layer forming resin. Preferably, the groove formed in the tubular body is formed by laser processing. In the tubular body, it is preferable that the inner layer is formed thicker than the outer layer on the distal end side, and the outer layer is formed thicker than the inner layer on the base end side.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A medical tube according to the present invention will be described with reference to the drawings.

FIG. 1 is a partially omitted enlarged view of an embodiment in which the medical tube of the present invention is applied to a catheter. FIG.
FIG. 2 is an enlarged front view of a distal end portion of the medical tube shown in FIG. 1. FIG. 3 is an enlarged sectional view of the distal end portion of the medical tube shown in FIG. FIG. 4 is an enlarged cross-sectional view of an intermediate portion of the medical tube shown in FIG. FIG. 5 is an enlarged cross-sectional view of a proximal end portion of the medical tube shown in FIG.

The medical tube 1 of the present invention is formed of a material which covers the lumen 3 formed therein, the inner layer 4 made of a soft synthetic resin, and the outer surface of the inner layer 4 made of a synthetic resin, and which is harder than the material forming the inner layer. And an outer layer 5. The thickness ratio of the inner layer 4 to the outer layer 5 on the distal end side of the medical tube 1 is larger than the thickness ratio of the inner layer 4 to the outer layer 5 on the proximal end side. Since it has a groove that extends in the lumen direction and has a pitch that gradually changes and does not reach the lumen 3, it is possible to have sufficient strength at the base end while providing flexibility at the tip. It becomes possible. Also, when the tube is bent, the bending stress is dispersed in the groove portion, so that the kink resistance is excellent.

Therefore, a description will be made with reference to the embodiment shown in FIGS. This embodiment is an embodiment in which a medical tube is applied to a catheter.

The catheter 1, which is a medical tube, includes a catheter body 2 and a hub 11 attached to the proximal end of the catheter body 2. As the catheter, a vascular catheter inserted into a blood vessel such as a heart blood vessel or a cerebral blood vessel, and further, a catheter inserted into a body cavity such as an abdominal cavity or a lung can be considered.

The catheter body 2 has a lumen formed therein from the distal end 21 to the proximal end 22. The lumen 3 serves as a flow path for a drug solution or the like, and a guide wire is inserted into the lumen 3 when the catheter 1 is inserted into a blood vessel. The hub 11 functions as an injection port for a drug solution or the like into the lumen 3 and an insertion port for a guide wire, and also functions as a grip when the vascular catheter 1 is operated.

As shown in FIG. 2 to FIG. 5, the catheter body 2 has at least a main portion composed of a soft synthetic resin inner layer 4 and a hard outer layer 5 closely adhered to the outer surface of the soft synthetic resin inner layer. It has a structure. The distal end portion 6 of the catheter body 2 having a relatively large thickness ratio of the inner layer 4 to the outer layer 5 and the thickness ratio of the inner layer 4 and the outer layer 5 are changed (toward the proximal end of the catheter body 2). (The inner layer 4 is thinner and the outer layer 5 is thicker)
And a base end 8 having a smaller thickness ratio of the inner layer 4 to the outer layer 5 as compared to the outer layer 5.

As described above, the ratio of the thickness of the soft inner layer 4 to the thickness of the hard outer layer 5 is reduced at the base end portion 8 and the thickness ratio of the distal end portion 6 is reduced.
As a result, the distal end portion 6 is formed to be flexible, and the proximal end portion 8 is formed to have high rigidity. And the groove 9 described in detail later
Is further formed on the distal end portion 6, the distal end portion 6 can be made much more flexible than the base end portion 8, and a large difference in rigidity between the two portions can be ensured. Therefore, the tip portion 6 is very flexible, and has excellent tip flexibility and trackability. On the other hand, the inner layer 4
In the base end portion 8 having a smaller thickness ratio to the outer layer 5 than in the distal end portion 6, a high hardness is secured and the pushability is excellent.

As shown in FIG. 4, in the intermediate portion 7, the inner layer 4
The thickness of the outer layer 5 gradually decreases toward the proximal end of the catheter body 2 while the thickness of the outer layer 5 gradually increases toward the proximal end of the catheter body 2. Accordingly, the change in the rigidity from the base end portion 8 to the distal end portion 6 becomes gentle, and there is very little possibility that the kink or the bending which is likely to occur due to the rapid change in the rigidity is generated in the catheter 1. Furthermore, the curvature of the catheter 1 becomes more natural, and the operability of the catheter is improved.

In the embodiment shown in FIGS. 1 to 5, the inner layer 4 is thicker than the outer layer 5 at the distal end portion 6 (the inner layer is thicker than the outer layer), and the outer layer 5 is 4 (the thickness of the outer layer is larger than the thickness of the inner layer). In this way, even if the catheter 1 is formed to have a very small diameter and a small thickness, a difference in rigidity between the distal end portion 6 and the proximal end portion 8 can be clearly provided, and the distal end portion 6 can be formed.
Can be formed flexibly to have excellent distal flexibility and trackability, and the base end portion 8 can be formed to have high hardness so as to have excellent pushability.

In the embodiment shown in FIGS. 1 to 5, a spiral groove 9 is provided in the outer layer 5 at the tip end portion 6. The tip 6 has a spiral groove 9 in the outer layer 5.
Is formed, and a groove non-formed portion 62 on the base end side of the groove 61 where no groove is provided. The groove 9 extends a predetermined length from the vicinity of the distal end of the outer layer 5 toward the base end, extends inward (lumen direction) from the outer surface of the outer layer 5, and is formed so as not to penetrate the inner layer 4. The groove 9 extends in the axial direction of the outer layer 5. By providing the groove 9, the groove forming portion 61 can be made more flexible than the portion 62 having no groove, the intermediate portion 7, and the base end portion 8.

By providing a groove only in the distal end portion 61 of the distal end portion 6, the rigidity of the intermediate portion 7 is higher than that of the intermediate portion 7 between the groove forming portion 61 and the intermediate portion 7. Since the non-groove forming portion 62 having lower rigidity is formed, the change in the physical properties of the catheter 1 can be smoothly changed. By doing so, the catheter 1 becomes gradually softer toward the distal end thereof, so that the curvature of the catheter 1 becomes more natural and the operability of the catheter is further improved. The present invention is not limited to such a configuration, and the groove 9 may be provided over the entire length of the distal end portion 6.

In the embodiment shown in FIGS. 1 to 5, the pitch of the grooves 9 is formed such that the pitch at the distal end portion of the groove forming portion 6 is smaller than the pitch at the proximal end portion. In particular, in this embodiment, the groove 9 becomes smaller toward the distal end of the catheter. By forming in this manner, the physical properties of the groove forming portion 6 of the catheter body 2 can be smoothly changed. In the present invention, the pitch may be constant over the entire groove 9.

The spiral pitch of the groove 9 is preferably about 1/5 to 10 times the outer diameter of the outer layer 5. When the pitch is 1/5 or more of the outer diameter of the outer layer 5, the strength at the tip of the outer layer 5 is not much reduced, and there is no tearing or breakage at this portion, and it is smaller than 10 times the outer diameter. If this is the case, the dispersion of the stress with respect to the curvature or bending of the blood vessel is sufficient.

The spiral groove 9 is, as described above,
It is preferable that the pitch is small on the distal end side of the groove forming portion 6 and large on the proximal end side. By doing so, the tip becomes softer toward the distal end side, so that there are few sudden changes in physical properties, the curvature at the boundary between the groove forming part 6 and the groove non-forming part 7 becomes natural, and the operability of the catheter is improved. Is improved. Further, it is preferable that the pitch of the grooves 9 is small at the leading end of the groove forming portion 6 and gradually increases toward the base end. By doing so, the flexibility gradually increases toward the distal end, so that the curvature of the groove forming portion becomes more natural, and the operability of the catheter is further improved.

As described above, when the pitch of the groove 9 changes, the length of the leading end (the small pitch) of the groove forming portion 6 is about 10 to 100 mm, and the length of the base end (the pitch is small). The large portion is preferably about 100 to 300 mm.
In particular, it is preferable that the intermediate portion between the distal end portion and the proximal end portion has an intermediate pitch between them or the pitch is gradually changed. Within the above range, it is sufficiently flexible and does not kink during use. Further, in the catheter shown in FIG. 3, the groove is a single spiral groove, but is not limited thereto.
The grooves may be two or more. In particular, FIG.
As shown in FIG. 3, by gradually changing the pitch of the groove, the pitch of the spiral groove at the distal end is very flexible because the pitch is narrow, and the distal end has excellent flexibility and trackability, and the spiral groove at the base end. The pitch required for the catheter is large because the pitch is wide or the helical groove is not formed.Moreover, at the proximal end, the thickness of the hard outer layer is increased, so that the hardness is ensured. Will be very excellent.

The length of the portion where the groove 9 is provided is about 10 to 300 mm or the outer layer 5 in order to distribute the stress appropriately.
Is preferably about 10 to 500 times the outer diameter of

In the catheter shown in FIGS. 1 to 3, the starting point on the tip side of the groove 9 is located at a position slightly separated from the tip of the outer layer 5. The distance between the tip of the outer layer 5 and the starting point of the groove 9 is preferably within 1.0 mm, more preferably within about 0.5 mm from the tip of the outer layer 5. Further, the groove 9 may be provided from the tip of the outer layer 5.

It is preferable that the depth of the groove 9 penetrates the outer layer 5 and reaches the inner layer 4 made of a soft synthetic resin. In this way, by making the groove penetrate the outer layer 5, the groove portion or the bottom portion of the groove can be formed only from the soft synthetic resin inner layer, and the groove portion can be made sufficiently flexible. It can be. Furthermore, the groove 9
Preferably reaches the inside of the soft synthetic resin inner layer 4. The depth of penetration into the soft synthetic resin inner layer 4 varies depending on the thickness of the soft synthetic resin inner layer 4, but is 0 to 1.
The thickness is preferably about 00 μm, particularly about 20 to 50 μm. Moreover, 1/5 to 1 of the thickness of the inner layer 4 made of the soft synthetic resin.
Is preferred.

The medical tube of the present invention comprises a catheter,
It can be used for endoscope tubes. The total length of the medical tube varies depending on the application, but is 500 to 20.
The thickness is preferably about 00 mm. When a portion (intermediate portion) where the thickness of the inner and outer layers changes as shown in FIGS. 1 to 5 is provided, the length is preferably 100 to 1500 mm. The total length of the medical tube is preferably about 1000 to 1500 mm when used for a catheter, and about 1000 to 2000 mm when used for an endoscope.

The outer diameter of the medical tube 1 is also different depending on the application.
The thickness is preferably about 3.0 to 3.0 mm, and preferably about 0.02 to 0.1 mm when used for an endoscope. Note that the outer diameter of the medical tube is preferably a constant size over the entirety, but the outer diameter may vary over the entirety. For example, the outer diameter may increase continuously or stepwise from the distal end to the proximal end of the medical tube. Also,
The inner diameter of the medical tube may not be constant as shown in the figure, but may be partially changed.

The thickness of the medical tube (total thickness of the inner layer and the outer layer) is preferably 0.04 to 0.5 mm, of which the outer layer has a thickness of 0.01 to 0 mm at the distal end. .
It is preferably 25 mm, and more preferably 0.02 to 0.45 mm on the proximal side.

[0037] In the case of applying a medical tube to a catheter, for example, in the case of a vascular catheter used by inserting it into a cerebral blood vessel, the overall length of the catheter body 2 is about 500 to 2000 mm, particularly 100
It is preferably about 0 to 1500 mm. Outer diameter is 0.6-2.0
mm, more preferably about 0.7 to 1.2 mm,
The inner diameter is about 0.2 to 1.6 mm, more preferably 0.5 to 1.6 mm.
It is about 0.9 mm. Further, the thickness of the outer layer 5 is about 0.01 to 0.3 mm on the tip side, more preferably 0.05 mm.
About 0.2 mm, 0.15 to 0.45 mm on the proximal side
And more preferably about 0.25 to 0.4 mm.
The thickness of the soft synthetic resin inner layer 4 is 0.0
About 5 to 0.5 mm, more preferably 0.08 to 0.3 mm
About 0.01 to 0.3 mm, more preferably about 0.05 to 0.2 mm on the base end side. Further, the length of the distal end portion 6 where the thickness of the outer layer on the distal end side is small is 100 to 100
About 0 mm, more preferably about 300 to 800 mm, and the length of the intermediate portion 7 where the thickness of the inner and outer layers changes is 100 to 100 mm.
It is about 1000 mm, more preferably about 300 to 800 mm.

In the examples shown in FIGS. 1 to 5, the thicknesses of the inner layer 4 and the outer layer 5 are constant at the distal end 6 and the proximal end 8, respectively. However, the present invention is not limited to such a configuration, and the distal end portion 6 and the proximal end portion are provided within a range in which the thickness ratio of the inner layer to the outer layer is higher on the proximal side than on the distal side of the medical tube. 8, the thickness of the inner and outer layers may be changed.

Further, it is preferable that the bottom surface of the groove 9 has a rounded shape. The bottom of the groove has a rounded shape, compared to the bottom of the groove having a rectangular shape. It becomes something. The shape of the spiral groove may be spiral, and the width of the groove may be wide at the distal end and narrow at the proximal end. By doing so, the catheter gradually becomes more flexible toward the distal end, so that the distal end of the catheter is more naturally curved and the operability of the catheter is further improved.

Although the width of the groove 9 is determined in consideration of the outer diameter of the outer layer 5 (catheter) and the like, it is not uniform, but is preferably 0.1 to 0.5 mm, and more preferably 0.1 to 0.5 mm. 0.
2 mm is preferred. The tip of the groove forming portion 6 is 1
It is preferably about 0 to 100 mm, and 100 to 3 mm at the base end.
00 mm is preferred. When changing the width of the groove, the width of the groove is set to 1/10 of the outer diameter of the outer layer 5 (catheter).
It is preferably about １ ／.

The outer layer 5 is preferably made of a relatively rigid polymer material. Such polymer materials include, for example, polyolefin-based resins such as polyethylene, polypropylene, polybutene, vinyl chloride, ethylene-vinyl acetate copolymer or their polyolefin-based elastomers, fluorine-based resins or fluorine-based elastomers, methacrylic resin, polyphenylene Oxide, modified polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polyurethane elastomer, polyester elastomer, polyamide or polyamide elastomer, polycarbonate,
Polyacetal, styrene resin or styrene elastomer, thermoplastic polyimide and the like can be used. It is also possible to use polymer alloys or polymer blends based on these resins. The material of the outer layer 5 is usually the same along the longitudinal direction, but the composition may be different depending on the site as required.

The outer layer may be made of a metal material. As metal materials, Cu, Ag, Au, Al, Ti, Pt, Ni,
Zn, Pb, Fe, Cr and the like can be used. Alternatively, an alloy of these metals can be used. When the outer layer is formed of a metal, a thin metal tube made of the above-mentioned metal may be used.Also, by depositing the above-described metal on the outer surface of the above-described inner layer, the outer surface of the inner layer may be formed. The outer layer may be directly applied to the substrate. Further, a groove as described above is formed in a two-layer structure tube having an outer layer made of such a metal deposition, and after removing the outer layer forming metal that becomes the groove portion, the same or different layer is further formed on the outer layer forming metal. The thickness of the outer layer may be adjusted by plating a metal. As the metal used for plating, the above-described metal for forming an outer layer is preferable.

The soft synthetic resin inner layer 4 is made of an outer layer forming material 5
It is made of a polymer material that is more flexible than that of. Such polymer materials include, for example, polyethylene elastomers, polypropylene elastomers, polybutene elastomers, soft vinyl chloride, polyolefin resins such as ethylene-vinyl acetate copolymer, or polyolefin elastomers thereof, fluorine elastomers, polyurethane elastomers And thermoplastic elastomer materials such as polyester-based elastomers, polyamide-based elastomers, and styrene-based elastomers. Further, a polymer alloy or a polymer blend based on these resins may be used.

Here, as the polyamide elastomer, for example, nylon 6, nylon 64, nylon 61
0, Nylon 612, Nylon 46, Nylon 9, Nylon 11, Nylon 12, N-alkoxymethyl-modified nylon, hexamethylenediamine-isophthalic acid condensed polymer, metaxyloyldiamine-adipic acid condensed polymer Alternatively, a block copolymer in which an aromatic polyamide is used as a hard segment and a polymer such as polyester or polyether is used as a soft segment is typical.

Examples of the polyamide elastomer include, in addition to the above, a polymer alloy of the polyamide and a resin having high flexibility (polymer blend, graft polymerization, random polymerization, etc.), or a polyamide obtained by softening the polyamide with a plasticizer or the like.
Furthermore, these mixtures are also included. The plasticizer is
It is preferable to use one that is difficult to extract with a solvent or blood.

A typical example of the polyester elastomer is a block copolymer of a saturated polyester such as polyethylene terephthalate or polybutylene terephthalate, and a polyether or polyester. Incidentally, the polyester elastomer, in addition to the above, a polymer alloy of the above polyester elastomer or the above-mentioned saturated polyester softened with a plasticizer or the like, further,
These mixtures are also included.

The elastomer may contain various additives such as an alloying agent, a compatibilizer, a curing agent, a stabilizer, and a coloring agent, if necessary. In this case, it is preferable to use an additive component that is difficult to extract with a solvent, a drug solution, blood, or the like. Further, the elastomer is preferably a thermoplastic resin, and if it is thermoplastic, the manufacture of the catheter is easy.

When the soft synthetic resin inner layer 4 is made of the above-mentioned elastomer, the outer layer 5 which is in close contact with the soft synthetic resin inner layer 4 does not hinder the deformation of the distal end of the soft synthetic resin inner layer 4. Since it is easily deformed in accordance with this deformation, the occurrence of kink is extremely reliably prevented. The material of the inner layer 4 made of the soft synthetic resin is usually the same along the longitudinal direction, but the composition may be different depending on the site as required.

Further, when the two-layered tube is formed by co-extrusion, the material of the outer layer 5 and the inner layer 4 is selected from the above-mentioned resins from the viewpoint of moldability. It is necessary to. Good compatibility
It indicates that thermodynamic mutual solubility is good, in other words, it indicates that there is no separation between the two after curing. Specifically, it is desirable to select the same resin as the material of the outer layer 5 and the inner layer 4. For example, a high-rigidity high-density polyethylene is selected as the material of the outer layer 5 and a soft low-density polyethylene is selected as the material of the inner layer 4.
The material of the inner layer 4 is selected from a highly rigid nylon 12 and the material of the inner layer 4 is selected from a flexible polyether polyamide block copolymer.
It is conceivable that a highly rigid polyethylene terephthalate is used as the material of the inner layer 4 and a soft polyester elastomer is selected as the material of the inner layer 4 and both are made of a polyester.

An X-ray opaque substance may be added to the material for forming the outer layer or the inner layer, and further to the material for forming the outer layer and the inner layer. As the X-ray opaque substance, for example, tungsten,
Fine particles made of a single metal or a compound such as barium sulfate, bismuth, gold, and platinum are preferred. The particle size of the X-ray opaque substance is preferably from 1 to 5 μm. The amount of the X-ray opaque substance added to the synthetic resin is 45% by weight.
Or less, and particularly preferably 30% by weight or less. More preferably, it is at most 20% by weight.

The hardness of the material forming the outer layer 5 (flexural modulus, AS
TM D-790, 23 ° C) is 2000 to 30000 kg / cm ²
And more preferably 5,000 to 20,000 kg / cm ² . Flexural modulus is 2000kg / c
If it is not less than m ² , the pushability and torque transmission are sufficient, and if it is not more than 30,000 kg / cm ² , the followability to the guide wire is good and the load applied to the inner wall of the blood vessel is small.

The hardness (flexural modulus, ASTM D-790, 23 ° C.) of the material for forming the soft synthetic resin inner layer 4 is 100
~ 800 kg / cm ² , preferably 150 ~ 500
More preferably, it is kg / cm ² . Flexural modulus is 10
If it is 0 kg / cm ² or more, it will have a certain degree of pushability and torque transmission, and if it is 800 kg / cm ² or less, it will have sufficient followability to the guide wire and will have little load on the inner wall of the blood vessel.

The hardness (flexural modulus, ASTM D-790, ASTM D-790) of the forming material used for the inner layer 4 and the outer layer 5 made of a soft synthetic resin.
Difference 23 ° C.) is preferably 1000~30000kg / cm ^2, more preferably 5000~10000kg / cm ^2.

In the catheter of this embodiment, the inner peripheral surface of the outer layer 5 is in close contact with almost the entire outer peripheral surface of the inner layer 4 made of the soft synthetic resin, and both are fixed. As a method of fixing both, for example, a method of forming by co-extrusion as described above, a method of bonding the soft synthetic resin inner layer 4 and the outer layer 5 with an adhesive or a solvent, and a method of bonding the soft synthetic resin inner layer 4 and the outer layer 5 (For example, heat fusion, high frequency fusion)
Examples include a method of coating the outer surface of the inner layer forming tube with the outer layer forming material by dipping, coating, extrusion, and the like. Further, when a metal is used as the outer layer forming material, the above-described method is used.

As a method of changing the thickness ratio of the inner and outer layers of the two-layer tube as in the illustrated intermediate portion 7, if the method is a co-extrusion molding method, for example, the portion where the thickness ratio of the tube is desired to be changed This can be achieved by changing the discharge amounts of the inner layer forming resin and the outer layer forming resin from the molding machine for forming each layer with the passage of the pick-up time by the program control. If the outer surface of the inner layer constituting tube is coated and formed by extrusion, for example, a tube for the inner layer having different outer diameters on the distal side and the proximal side is prepared in advance, and the outer layer is coated with This can be achieved by passing through a die for regulating the outer diameter. If the outer surface of the inner layer constituting tube is coated by dipping, for example, an inner layer tube having a different outer diameter on the distal side and the proximal side is prepared in advance, and the dice is passed through the dice from the dipping solution. This can be achieved by pulling up the tube.

Examples of the method of forming the groove include cutting, laser processing, and the like. Laser processing is preferable for performing high-precision fine processing, and among laser processing, excimer laser processing suitable for polymer processing is preferable. Particularly preferred. However, when groove processing is performed by laser processing, it is necessary to select a material having good laser processing properties.

Further, there is provided an outer layer 2 made of a metal deposit.
After forming the groove as described above in the layered tube and removing the outer layer forming metal which becomes the groove portion, the same or a different metal is further plated on the outer layer forming metal by electrolytic plating or electroless plating to reduce the thickness of the outer layer. It may be adjusted to be thicker. In order to change the thickness ratio of the inner and outer layers between the distal end portion and the proximal end portion, it can be achieved by masking a portion where the outer layer is not desired to be thickened. As the metal used for plating, the above-mentioned metal for forming an outer layer is preferable. The medical tube of the present invention is a tube having a two-layer structure of an inner layer and an outer layer formed in advance and formed with a groove from the outside (the hard outer layer side), so that the inner layer and the outer layer can be made thinner, thinner and more excellent. Characteristics.

The shape of the groove to be formed is preferably the above-mentioned spiral shape. Such a spiral groove has an inner layer made of a soft synthetic resin and the soft synthetic resin as shown in FIG. A tubular body 40 having an outer layer made of a material harder than a resin and having a thickness ratio of the inner layer to the outer layer at the distal end side larger than a thickness ratio of the inner layer to the outer layer at the base end side. While sending in the axial direction while rotating in the direction, by the laser irradiation device 41,
The spiral groove 9 is formed by irradiating a beam of a certain shape onto the tubular body 40. Further, as described above, it is preferable that the spiral groove has a small pitch on the distal end side and a large pitch on the proximal end side of the groove forming portion of the medical tube. For this reason, the feed speed in the axial direction of the tubular body 40 is
By gradually increasing the pitch in the direction of the arrow shown in FIG. 18, the pitch to be formed can be changed as described above.

The shape of the beam spot may be a circle, an ellipse, a triangle, a square, a parallelogram, or any other shape, but a round shape having a constant groove width even when the helical pitch is changed is preferable. Yes, and the size of the beam spot is preferably 0.02 to 0.5 mm. Also, by using such a round beam spot,
The cross-sectional shape of the groove is rounded, and the bending stress is effectively dispersed when the medical tube is bent, as compared with the case of the angular cross-sectional shape, and the kink resistance is excellent.

Further, the depth of the groove is preferably such that the thickness of the outer layer 5 can be sufficiently removed, and specifically, the maximum depth is preferably 0.02 to 0.2 mm.

In the embodiment shown in FIGS. 1 to 5, the thickness of the inner layer 4 is larger than the thickness of the outer layer 5 at the distal end portion 6, and the thickness of the outer layer 5 is larger than the thickness of the inner layer 4 at the base end portion 8. The present invention is not limited to such a configuration, but may be, for example, one shown in FIGS. 6 to 9.

FIG. 6 is a partially omitted enlarged front view of another embodiment in which the medical tube of the present invention is applied to a catheter. FIG. 7 is an enlarged sectional view of the distal end portion of the medical tube shown in FIG. FIG. 8 is an enlarged cross-sectional view of an intermediate portion of the medical tube shown in FIG. FIG. 9 is an enlarged cross-sectional view of the proximal end of the medical tube shown in FIG. The difference between the catheter (medical tube) 10 shown in these figures and the embodiment shown in FIGS. 1 to 5 is only in the thickness of the inner and outer layers and the outer diameter of the catheter body 2. Are the same as those shown and described in FIGS.

In the distal end portion 6 of the catheter 10, FIG.
As shown in FIG. 8, the thickness of the outer layer 5 is the same as or slightly larger than the thickness of the inner layer 4. In the intermediate portion 7, as shown in FIG. 9, the thickness of the outer layer 5 is gradually increased (the thickness of the outer layer 5 is increased), and the thickness of the outer layer 5 is considerably larger than the thickness of the inner layer 4 at the base end portion 8 as shown in FIG. ing.

In such a configuration, the thickness ratio of the inner layer 4 to the outer layer 5 on the distal end side of the catheter (medical tube) 10 is the same as that of the catheter (medical tube) 1.
The thickness ratio of the inner layer 4 to the outer layer 5 at the base end side of 0 is larger than the thickness ratio. Further, the distal end 6 is provided with a groove extending from the outer surface of the outer layer 5 in the direction of the lumen 3 and not reaching the lumen 3, so that the distal end 6 is much more flexible than the proximal end 8. Thus, a large difference in rigidity between the two portions can be ensured. Therefore, the distal end portion 6 is very flexible, has excellent distal end flexibility and trackability, and the base end portion 8 can secure high hardness and has excellent pushability.

In the embodiment shown in FIGS. 6 to 9, the inner layer 4 is formed to have a substantially constant thickness over the entire length of the catheter 1. In addition, the outer diameter of the catheter 10 increases toward the proximal end of the catheter body 2 at the intermediate portion 7, and the outer diameter at the proximal end portion 8 is larger than that at the distal end portion 6. In this embodiment, the thickness of the inner layer 4 may be changed at each of the distal end portion, the intermediate portion, and the proximal end portion.

In the embodiment shown in FIGS. 1 to 5, FIG.
Also, both of the embodiments shown in FIG. 9 to FIG. 9 have a configuration including the intermediate portion 7 in which the thickness ratio of the inner and outer layers changes, but the present invention is not limited to such a configuration, and as described above. (Without a substantially constant thickness ratio between the inner and outer layers at the distal and proximal ends of the tube)
A configuration in which the thickness ratio of the inner and outer layers changes continuously at a constant rate from the distal end to the proximal end of the medical tube.

Further, like the catheter 20 (medical tube) shown in FIGS. 10 to 12, the end of the groove on the outer surface of the outer layer 5 may be chamfered. FIG.
0 is a partially omitted enlarged front view of another embodiment in which the medical tube of the present invention is applied to a catheter. FIG. 11 is an enlarged front view of the distal end portion of the medical tube shown in FIG. FIG. 12 is an enlarged sectional view of a distal end portion of the medical tube shown in FIG. By using the catheter 20, it is possible to moderately change the physical properties in the vicinity of the end of the groove to some extent, and the curvature in the groove is improved, and the operability is improved. This catheter 2
0 (medical tube) and the above-described catheter 1 (medical tube) are the only points described above, and the other points are the same as those shown and described in FIGS. 1 to 5.

Further, like the catheter 30 (medical tube) shown in FIGS. 13 to 15, a plurality of annular grooves 39 may be provided on the outer surface of the outer layer 5. The difference between the catheter 30 (medical tube) of this embodiment and the catheter 1 (medical tube) shown and described in FIGS. 1 to 5 is only the groove form, and the other points are shown in FIGS. Are the same as those shown and described above.

In the catheter 30, a plurality of annular grooves 39 are formed at the distal end. The plurality of annular grooves 39 may be arranged at equal intervals. However, as shown in FIGS. 13 to 15, the interval between adjacent grooves is small at the distal end of the groove forming portion 36 and wide at the base end. Preferably, it is formed. By doing so, the catheter becomes flexible toward the distal end, so that the distal end of the catheter is naturally curved, and the operability of the catheter is improved. In particular, as shown in FIG. 13, it is preferable that the groove interval gradually increases toward the base end of the groove forming portion. In this way, the distal portion is very flexible, has excellent distal flexibility and trackability, secures the hardness required for the catheter at the proximal end, and has a thick outer layer at the proximal end. Since the thickness is thicker, the hardness is more secured and the pushability is excellent.

Since the groove interval is determined in consideration of the outer diameter of the outer layer 5 (catheter), it is not uniform.
The thickness is preferably about 0.1 to 5 mm at the distal end of the groove forming portion, and is preferably 5 to 10 mm at the proximal end. Further, the width of the groove is preferably 0.1 to 0.5 mm, particularly,
0.1-0.2 mm is preferred. Further, the width of the groove is preferably about 1/10 to 1/2 of the outer diameter of the outer layer 5 (catheter).

The depth of the groove 39 is preferably such that the groove 39 penetrates the outer layer 5 and reaches the soft synthetic resin inner layer 4. As described above, by forming the groove through the outer layer 5, the groove can be formed only from the soft synthetic resin inner layer, and the groove can be made sufficiently flexible. . Further, the groove 39 preferably reaches the inside of the soft synthetic resin inner layer 4. The degree of penetration into the soft synthetic resin inner layer 4 varies depending on the thickness of the soft synthetic resin inner layer 4, but is preferably about 0 to 100 μm, and particularly about 20 to 50 μm. Also,
The thickness of the soft synthetic resin inner layer 4 is preferably about 1/5 to 1/3.

Further, it is preferable that the bottom surface of the groove has a rounded shape. The bottom of the groove has a rounded shape, compared to the bottom of the groove having a rectangular shape. It becomes something.

Further, as shown in FIGS. 16 and 17, the ends of the grooves on the outer surface of the outer layer 5 may be chamfered.

In the case where the spiral groove or the plurality of annular grooves are provided as described above, the present invention is not limited to the above-described embodiment in which the spiral groove pitch or the groove interval changes, and the width of the groove is It may be formed so as to be wide at the distal end and narrow at the proximal end. By doing so, the distal end side of the groove forming portion becomes more flexible than the proximal end side, so that the distal end portion of the catheter is more naturally curved and the operability of the catheter is improved. Since the width of the groove is determined in consideration of the outer diameter of the outer layer 5 (catheter) and the like, the width is not uniform.
, The width of the groove at the base end portion is 0.1 to 0.1.
It is preferably about 8, and particularly preferably about 0.3 to 0.5. In particular, it is preferable that the width of the groove is gradually reduced from the distal end of the groove forming portion toward the base end side. Further, as described above, the width of the groove may be changed together with the spiral groove pitch or the groove interval as described above.

As a setting factor of the hardness of the medical tube of the present invention, regarding the tube, the material of the inner and outer layers of the tube,
Examples include the tube size, the thickness ratio of the inner and outer layers on the distal end side and the tube length in the thickness ratio, the inner and outer layer thickness ratio on the base end side, and the tube length in the thickness ratio. Regarding the processing groove, spiral groove pitch, groove interval,
Examples include the width of the groove, the groove pattern, the groove depth, and the like. By setting these parameters arbitrarily, medical tubes having various mechanical properties can be manufactured. The helical pitch can be set arbitrarily, and a part can be partially hardened.
The medical tube of the present invention is formed by forming a spiral groove on the outer wall of the tube and is not formed in a coil shape, so that the torque transmission is also good.

The outer surface of the medical tube (catheter) may be coated with a hydrophilic polymer compound which exhibits lubricity when coming into contact with blood. Examples of a method of coating the outer surface of the tube with a lubricating substance include a method of coating the outer surface with a hydrophilic polymer compound exhibiting lubricity when wet or silicone oil. Examples of the hydrophilic polymer compound include a methyl vinyl ether maleic anhydride copolymer or an ester compound copolymer thereof, a polyvinylpyrrolidone compound, and hydroxypropyl cellulose.

As a method for coating such a hydrophilic polymer compound, for example, the hydrophilic polymer compound is dissolved in an appropriate solvent such as methyl ethyl ketone, acetone, tetrahydrofuran, dioxane, dimethylformaldehyde, alcohols, dimethyl sulfoxide and the like. Then, the solution is immersed, coated, impregnated on the outer surface of the tube by a method such as spraying, and after the impregnation, the solvent is removed by drying or washing treatment, and the hydrophilic polymer compound is introduced into the polymer material of the base material. To be left behind.

By coating such a lubricating substance, the contact area between the outer surface of the tube and the inner surface of the living body lumen can be reduced by forming the groove, and the slidability of the tube can be greatly improved. .

Further, the outer surface of the medical tube (catheter) may be coated with an antithrombotic material. Examples of the antithrombotic material include heparin, polyalkylsulfone, ethylcellulose, acrylate polymer, methacrylate polymer (for example, polyHEMA [polyhydroxyethyl methacrylate]), a hydrophobic segment and a hydrophilic segment. (E.g., a block copolymer of HEMA-styrene to HEMA, a block copolymer of HEMA-MMA [methyl methacrylate], and a block copolymer of HEMA-LMA [lauryl methacrylate] Coalescence, PVP
[Polyvinylpyrrolidone] -MMA block copolymer, HEMA-MMA / AA [acrylic acid] block copolymer), and a blend polymer obtained by mixing these block copolymers with a polymer having an amino group, and fluorine-containing polymer. Resin or the like can be used. Preferably, HEM
A-styrene-HEMA block copolymer, HEMA
-Block copolymer of MMA, HEMA-MMA / AA
And the like. Then, it is preferable that the blood contact surface is coated with a hydrophilic resin other than the above-mentioned heparin, and then heparin is further fixed thereon. In this case, in order to fix heparin on the surface of the hydrophilic resin, the hydrophilic resin includes a hydroxyl group, an amino group, a carboxyl group, an epoxy group, an isocyanate group, a thiocyanate group, an acid chloride group, an aldehyde group and a carbon-carbon group. It is preferable to have any of the double bonds or to have a group which can be easily converted to these groups. It is particularly preferable to use a blend polymer in which a polymer having an amino group is mixed with the hydrophilic resin,
As the polymer having an amino group, a polyamine, particularly, PEI (polyethyleneimine) is preferable.

Heparin is fixed by coating the blood contacting surface of a medical tube (catheter) with the above hydrophilic resin and bringing the surface into contact with a heparin aqueous solution, and then contacting an aldehyde such as glutaraldehyde, terephthalaldehyde or formaldehyde. , Diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, epichlorohydrin, 1,4-butanediol diglycidyl ether, polyethylene glycol diglycidyl ether, etc. It can be fixed to a resin by covalent bonding.

The wall thickness of the coating layer of such an antithrombotic material is preferably minimized so as not to substantially affect the flexibility and outer diameter of the tube.

Next, a method for manufacturing the medical tube of the present invention will be described.

The method of manufacturing a medical tube according to the present invention has an inner layer made of a soft synthetic resin and an outer layer made of a material harder than the soft synthetic resin, and a thickness ratio of the inner layer to the outer layer at the tip end is reduced. A step of preparing a tubular body that is larger than the thickness ratio of the inner layer to the outer layer on the base end side, and processing the surface of the tubular body to at least partially extend the longitudinal direction of the tubular body Forming a groove having a depth reaching the inner layer from the outer layer surface at the groove bottom portion and not reaching the inner lumen of the medical tube.

Therefore, each step will be described.

An inner layer made of a soft synthetic resin, and an outer layer made of a material harder than the soft synthetic resin, wherein the thickness ratio of the inner layer to the outer layer at the distal end is such that the inner layer has a thickness relative to the outer layer at the base end. The step of preparing the tubular body having a wall thickness ratio greater than the wall thickness includes, for example, a method of forming by co-extrusion, an inner layer forming tubular body made of a soft synthetic resin having different thicknesses on the distal side and the proximal side, and the soft body. A method in which an outer layer forming tubular body made of a material harder than a synthetic resin is formed in advance, and these are bonded with an adhesive or a solvent or fused (for example, heat fused, high frequency fused), An inner layer forming tubular body made of a soft synthetic resin having a different thickness at the base end side is formed in advance, and the outer surface thereof is coated with a material for forming an outer layer harder than the soft synthetic resin by dipping, coating, extrusion, or the like. Method, and the like.

As a specific method of changing the thickness ratio of the inner and outer layers of the two-layered tubular body, in the case of co-extrusion, for example, the synthetic resin for forming the inner layer and the synthetic resin for forming the outer layer in a molding machine are used. It can be achieved by co-extrusion molding while changing the discharge amount by program control. If the outer surface of the inner layer forming tube is formed by extrusion coating, for example, an inner layer forming tubular body having a different outer diameter on the distal end side and the proximal end side is formed in advance, and the material for forming the outer layer is formed. When coating the outer surface of the inner layer forming tubular body,
This can be achieved by passing through a die for regulating the outer diameter. Further, if the outer surface of the inner layer forming tubular body is coated with a material for forming the outer layer by dipping, for example,
This can be achieved by forming in advance a tubular body for forming an inner layer having different outer diameters at the distal end side and the proximal end side, and pulling up the tubular body from a dipping solution while passing through a die for regulating the outer diameter. .

It is preferable that the inner layer and the outer layer of the tubular body are each formed as a seamless integral body by the above-described method, for example. However, the present invention is not limited to such a configuration, and one or both of the inner layer and the outer layer may be provided with the distal portion and the proximal portion of the tubular body (the distal portion 6, the intermediate portion 7, When the base end portion 8 is provided, each portion corresponding to these portions 6, 7, 8)
And formed separately, and then joined by fusion, adhesion, or the like.

The material for forming the outer layer is preferably made of a polymer material having relatively high rigidity. Such polymeric materials include, for example, polyethylene, polypropylene,
Polyolefin resins such as polybutene, vinyl chloride, ethylene-vinyl acetate copolymer or their polyolefin elastomers, fluorine resins or fluorine elastomers, methacrylic resin, polyphenylene oxide, modified polyphenylene ether, polyethylene terephthalate, polybutylene terephthalate, polyurethane Various synthetic resins such as a series elastomer, a polyester series elastomer, a polyamide or a polyamide series elastomer, polycarbonate, polyacetal, a styrene series resin or a styrene series elastomer, and a thermoplastic polyimide can be used. It is also possible to use polymer alloys or polymer blends based on these resins. Also, the material of the outer layer forming material is usually
The composition is the same along the longitudinal direction, but the composition may be different depending on the site, if necessary.

The material for forming the outer layer may be made of a metal material. As metal materials, Cu, Ag, Au,
Al, Ti, Pt, Ni, Zn, Pb, Fe, Cr and the like can be used. Alternatively, an alloy of these metals can be used. When forming the outer layer by metal, by the above metal,
A thin metal tube having a different thickness between the distal side and the proximal side may be used.Also, by depositing the above-described metal on the outer surface of the above-described inner layer, the outer layer is directly formed on the outer surface of the inner layer. And a metal outer layer having a different thickness on the distal side and the proximal side may be formed. Furthermore, after forming a groove as described above in a two-layer structure tubular body having an outer layer made of such a metal deposit and removing the outer layer forming metal that becomes the groove portion, the same or the same is further formed on the outer layer forming metal. A different metal may be plated to adjust the thickness of the outer layer. As the metal used for plating, the above-described metal for forming an outer layer is preferable.

As the soft synthetic resin for forming the inner layer, a polymer material which is more flexible than the material for forming the outer layer is used.
Such polymer materials include, for example, polyethylene elastomers, polypropylene elastomers, polybutene elastomers, soft vinyl chloride, polyolefin resins such as ethylene-vinyl acetate copolymer, or polyolefin elastomers thereof, fluorine elastomers, polyurethane elastomers And thermoplastic elastomer materials such as polyester-based elastomers, polyamide-based elastomers, and styrene-based elastomers. Further, a polymer alloy or a polymer blend based on these resins may be used.

Here, as the polyamide elastomer, for example, nylon 6, nylon 64, nylon 61
0, Nylon 612, Nylon 46, Nylon 9, Nylon 11, Nylon 12, N-alkoxymethyl-modified nylon, hexamethylenediamine-isophthalic acid condensed polymer, metaxyloyldiamine-adipic acid condensed polymer Alternatively, a block copolymer in which an aromatic polyamide is used as a hard segment and a polymer such as polyester or polyether is used as a soft segment is typical.

Examples of the polyamide elastomer include, in addition to the above, a polymer alloy of the polyamide and a resin having high flexibility (polymer blend, graft polymerization, random polymerization, etc.), or a polyamide obtained by softening the polyamide with a plasticizer or the like.
Furthermore, these mixtures are also included. The plasticizer is
It is preferable to use one that is difficult to extract with a solvent or blood.

A typical example of the polyester elastomer is a block copolymer of a saturated polyester such as polyethylene terephthalate or polybutylene terephthalate with a polyether or polyester. Incidentally, the polyester elastomer, in addition to the above, a polymer alloy of the above polyester elastomer or the above-mentioned saturated polyester softened with a plasticizer or the like, further,
These mixtures are also included.

[0094] The elastomer may contain various additives such as an alloying agent, a compatibilizer, a curing agent, a stabilizer, and a coloring agent, if necessary. In this case, it is preferable to use an additive component that is difficult to extract with a solvent, a drug solution, blood, or the like. Further, the elastomer is preferably a thermoplastic resin, and if it is thermoplastic, the manufacture of the catheter is easy.

When the above-mentioned elastomer is used as the soft synthetic resin for forming the inner layer, the outer layer which is in close contact with the inner layer made of the soft synthetic resin can easily follow the deformation of the inner layer made of the soft synthetic resin without obstructing the deformation. Therefore, the occurrence of kink is very reliably prevented. The material of the inner layer made of the soft synthetic resin is usually the same along the longitudinal direction, but the composition may be different depending on the site as required.

Further, when the two-layered tubular body is formed by co-extrusion, the material of the outer layer 5 and the inner layer 4 is selected from the above-mentioned resins from the viewpoint of moldability and has good compatibility with both. It is necessary to make a choice. Good compatibility means that thermodynamic mutual solubility is good. In other words, it means that there is no separation between the two after curing. Specifically, it is desirable to select the same resin as the material of the outer layer 5 and the inner layer 4. For example, a high-rigidity high-density polyethylene is selected as the material of the outer layer 5 and a soft low-density polyethylene is selected as the material of the inner layer 4.
The material of the inner layer 4 is selected from a highly rigid nylon 12 and the material of the inner layer 4 is selected from a flexible polyether polyamide block copolymer.
It is conceivable that a highly rigid polyethylene terephthalate is used as the material of the inner layer 4 and a soft polyester elastomer is selected as the material of the inner layer 4 and both are made of a polyester.

An X-ray opaque substance may be added to the material for forming the outer layer or the inner layer, and further to the material for forming the outer layer or the inner layer. As the X-ray opaque substance, for example, tungsten,
Fine particles made of a single metal or a compound such as barium sulfate, bismuth, gold, and platinum are preferred. The particle size of the X-ray opaque substance is preferably from 1 to 5 μm. The amount of the X-ray opaque substance added to the synthetic resin is 45% by weight.
Or less, and particularly preferably 30% by weight or less. More preferably, it is at most 20% by weight.

[0098] By such a process, it is preferable that the inner layer is formed thicker than the outer layer on the distal end side and the outer layer is formed thicker than the inner layer on the base end side. In this way, even when the two-layered tubular body (medical tube) is formed to be extremely thin and thin, the rigidity between the distal side and the proximal side of the two-layered tubular body (medical tube) is improved. The difference between
The distal portion can be formed flexibly to have excellent distal flexibility and trackability, and the base portion can be formed to have extremely high hardness to have excellent pushability.

Next, a step of processing the surface of the tubular body to form a groove that does not reach the inner lumen of the tubular body is performed.

As a method of forming a groove that does not reach the inner lumen in the tubular body, cutting, laser processing, and the like can be mentioned. Laser processing is preferable for performing high-precision fine processing. Excimer laser processing suitable for polymer processing is particularly preferable. However, when groove processing is performed by laser processing, it is necessary to select a material having good laser processing properties.

Further, there is provided an outer layer 2 made of a metal deposit.
After forming the groove as described above in the layered tube and removing the outer layer forming metal which becomes the groove portion, the same or a different metal is further plated on the outer layer forming metal by electrolytic plating or electroless plating to reduce the thickness of the outer layer. It may be adjusted to be thicker. In order to change the thickness ratio between the inner and outer layers at the distal end portion and the proximal end portion, it is possible to achieve appropriate masking of a portion where the outer layer is not desired to be thickened. As the metal used for plating, the above-mentioned metal for forming an outer layer is preferable. The shape of the groove to be formed is preferably the above-described spiral shape. As shown in FIG. 18, such a spiral groove has an inner layer made of a soft synthetic resin and a harder harder than the soft synthetic resin. Rotating the tubular body 40 having an outer layer made of a suitable material, wherein the thickness ratio of the inner layer to the outer layer on the distal end side is greater than the thickness ratio of the inner layer to the outer layer on the proximal end side. While sending in the axial direction while doing, by the laser irradiation device 41,
The spiral groove 9 is formed by irradiating a beam of a certain shape onto the tubular body 40. Further, as described above, it is preferable that the spiral groove has a small pitch on the distal side and a large pitch on the proximal side of the groove forming portion of the medical tube. Therefore, by gradually increasing the feed speed in the axial direction of the tubular body 40 in the direction of the arrow shown in FIG. 18, the formed pitch can be changed as described above.

The shape of the beam spot may be any of a circle, an ellipse, a triangle, a square, a parallelogram, and other shapes, but a round shape having a constant groove width even when the helical pitch is changed is preferable. Yes, and the size of the beam spot is preferably 0.02 to 0.5 mm. Also, by using such a round beam spot,
The cross-sectional shape of the groove is rounded, and the bending stress is effectively dispersed when the medical tube is bent, as compared with the case of the angular cross-sectional shape, and the kink resistance is excellent. Further, the depth of the groove is preferably such that the thickness of the outer layer 2 can be sufficiently removed, and specifically, the maximum depth is 0.0
2 to 0.2 mm is preferred.

As for the setting factors of the hardness of the medical tube manufactured by the method for manufacturing a medical tube of the present invention, regarding the tube, the material of the inner and outer layers of the tube, the tube size, the thickness ratio of the inner and outer layers on the distal end side, and the thickness ratio The tube length in the wall thickness ratio, the wall thickness ratio of the inner and outer layers on the base end side, and the tube length in the wall thickness ratio are exemplified. Also,
Regarding the processing groove, a spiral groove pitch, a groove interval, a groove width, a groove pattern, a groove depth and the like can be mentioned. By arbitrarily setting these parameters, medical tubes having various mechanical properties can be manufactured. Also,
The spiral pitch can be set arbitrarily, and
It is also possible to partially harden a part. In addition, the medical tube of the present invention is formed by forming a spiral groove on the outer wall of the tube, and is not formed in a coil shape.

Hereinafter, the present invention will be specifically described with reference to specific examples. The embodiment is an example of the present invention, and the present invention is not limited to the embodiment.

[0105]

EXAMPLES As a material for forming an outer layer, polybutylene terephthalate (Polyplastics Co., Ltd., trade name: Juranex, grade 2002, flexural modulus: 26000 kg / c)
m ² , ASTM D-790, 23 ° C.).

As a material for forming the inner layer, a polyester elastomer (Toyobo Co., Ltd., trade name Perprene, grade P30B-05, flexural modulus 150 kg / cm ² , AST
MD-790, 23 ° C).

[0107] Both pellets were formed into a multilayer extruder (KIL
LION Co., Ltd., Model KL-075, 19mm) by copper wire coating molding, inner diameter 1.0mm, outer diameter 1.5mm
Was produced by the following method.

First, as the outer-layer thin-walled two-layer structure tubular body corresponding to the distal end portion (tip portion) of the medical tube of the present invention, the discharge ratio of the inner layer forming material and the outer layer forming material forming machine is set to 2: By setting to 1, the outer thin two-layer tubular body with outer diameter of 1.5 mm, inner diameter of 1.0 mm, outer layer thickness of about 0.07 mm and inner layer of about 0.18 mm is coated on the copper wire. It could be molded (Comparative Example 1). In addition, as the outer-layer thick-walled two-layer structure tubular body corresponding to the proximal portion (the proximal portion) of the medical tube of the present invention, the ratio of the discharge amount of the inner layer forming material to the outer layer forming material forming machine is 1: By setting to 2, the thickness of the outer layer is about 0.18 mm and the thickness of the inner layer is about 0.08 mm.
A 7 mm outer-layer, thick-walled, two-layered tubular body was able to be coated and formed on a copper wire (Comparative Example 2).

Next, by changing the discharge amount of the molding machine for each layer with the elapse of the picking-up time by program control for each unit length of the two-layered tubular body, the thickness ratio of the inner layer to the outer layer at the tip side is changed. Was larger than the wall thickness ratio of the inner layer to the outer layer at the base end side. Specifically, in a two-layered tubular body that is a base of a medical tube having a length of about 1.5 m, a portion having a tip portion of about 30 cm is an outer layer thin portion (amount of discharge: inner layer material / outer layer material = 2/1).
The portion of about 70 cm in the middle portion is a thickness transition portion (discharge amount: inner layer material / outer layer material = 2/1 to 1/2), and the base end portion is approximately 5 cm.
The portion of 0 cm was an outer layer thick portion (ejection amount: inner layer material / outer layer material = 1/2). The take-up speed during molding of the two-layer tubular body was set so that the outer diameter was 1.5 mm. The extrusion molding was performed at a temperature recommended by a resin manufacturer, and a copper wire having an outer diameter of 1.0 mm was used.

Then, after removing the copper wire in these two-layered tubular bodies, the core wire having an outer diameter of 0.9 mm was passed through, and annealed at 120 ° C. for 4 hours in an oven to remove residual stress distortion generated after molding. Remove and have lumens inside 2
A layered tubular body was produced.

A spiral groove was formed on the outer wall of the tubular body having a two-layer structure in which the thickness ratio of the inner and outer layers was changed, using an excimer laser (Model PM-848, Sumitomo Heavy Industries, Ltd.). As a processing method of the excimer laser, a mask imaging method of reducing and projecting a mask shape was used. The laser processing conditions were that the energy density on the tube surface was about 9.0 J / cm ² ,
The oscillation frequency was set to 100 Hz. The laser beam cross section is round and the beam spot diameter is about 0.19mm
The beam spot was arranged so as to be in contact with the upper surface of the outer wall of the two-layered tubular body, and the arrangement and the moving speed of the tube were set so that the thickness of the outer layer could be sufficiently removed by about 0.07 mm.

Under the above conditions, the pitch of the spiral groove was changed to 3.0 by changing the moving speed of the tube.
mm (length of groove forming portion 30 mm) medical tube (Example 1), medical tube with spiral groove pitch of 7.0 mm (length of groove forming portion 30 mm) (Example 2), spiral tube Medical tube having a pitch of 11.0 mm (length of groove forming portion 30 mm) (Example 3), medical tube having a pitch of spiral grooves of 15.0 mm (length of groove forming portion 30 mm) (Example 4)
Were prepared three each.

Further, under the above conditions, by gradually increasing the moving speed of the tube, the pitch of the spiral groove becomes
A medical tube (Example 5) was prepared, which gradually widened (the length of the groove-forming portion 200 mm) from 3.0 mm at the front end (starting end) to 15 mm at the end.

(Experiment) The medical tubes of Examples 1 to 4 and the two-layered tubular bodies of Comparative Examples 1 and 2 which were not subjected to groove processing were subjected to an autograph (Shimadzu Autograph, AGS-100A). ), A three-point bending test was performed under the measurement conditions of a distance between fulcrums of 20 mm and a test speed of 5 mm / min. To measure the flexural modulus. The results were as shown in Table 1.

Here, the bending elastic modulus is defined as 2 in the elastic deformation region obtained by the ordinary three-point bending test.
It is the Young's modulus for bending calculated as a function of the load-displacement gradient between points, the distance between fulcrums, and the second moment of area. At this time, the second moment of area of the tube was calculated on the assumption that the spiral groove on the tube surface was filled with the medium.

[0116]

[Table 1]

From this result, it is found that the bending elastic modulus increases as the helical pitch increases, and that the helical pitch is 15.0 mm.
Was found to be about 5.5 times harder than a tube with a helical pitch of 3.0 mm. In addition, it was found that the tube having the spiral pitch of 3.0 mm became about 1/7 softer than the unprocessed tube having a thin outer layer. Furthermore, even in the case of a raw tube, it was found that the outer layer thick tube was about twice as hard as the outer layer thin tube. And it turned out that a tube with a spiral pitch of 3.0 mm becomes about 1/15 more flexible than a tube with an unprocessed outer layer thick wall. Therefore, it was confirmed that the medical tube of the present invention can change mechanical properties depending on each position of the tube, in other words, it is possible to make the distal end portion flexible and the base end portion to have a waist.

[0118]

The medical tube of the present invention is formed of a lumen formed therein, an inner layer made of a soft synthetic resin, and a material which covers the outer surface of the inner layer and is harder than the material forming the inner layer. A thickness ratio of the inner layer to the outer layer at the distal end side of the medical tube, the thickness ratio of the inner layer to the outer layer at the proximal end side of the medical tube. Has also become larger, furthermore, the medical tube,
The distal end has a groove extending from the outer surface of the outer layer in the lumen direction and having a depth that does not reach the lumen.

For this reason, in addition to pushability, trackability, torque transmission, and kink resistance, the material has flexibility at the tip, and there is no sudden change in the physical properties in the middle part, and the physical properties change smoothly. Kink is less likely to occur and the tube can be bent well, which is effective for medical use.

Further, the method for manufacturing a medical tube of the present invention has an inner layer made of a soft synthetic resin and an outer layer made of a material harder than the soft synthetic resin, and the thickness of the inner layer with respect to the outer layer on the distal end side. Providing a tubular body having a ratio greater than the wall thickness ratio of the inner layer to the outer layer at the proximal end, and processing the surface of the tubular body to provide at least one over the longitudinal direction of the tubular body. Forming a groove having a depth that reaches the inner layer from the outer layer surface at the groove bottom portion and does not reach the inner lumen of the medical tube. Therefore, the medical tube as described above can be manufactured reliably and easily.

[Brief description of the drawings]

FIG. 1 is a partially omitted enlarged view of an embodiment in which the medical tube of the present invention is applied to a catheter.

FIG. 2 is an enlarged front view of a distal end portion of the medical tube shown in FIG.

FIG. 3 is an enlarged sectional view of a distal end portion of the medical tube shown in FIG.

FIG. 4 is an enlarged sectional view of an intermediate portion of the medical tube shown in FIG. 1;

FIG. 5 is an enlarged cross-sectional view of a proximal end portion of the medical tube shown in FIG.

FIG. 6 is a partially omitted enlarged front view of another embodiment in which the medical tube of the present invention is applied to a catheter.

FIG. 7 is an enlarged sectional view of the distal end portion of the medical tube shown in FIG.

FIG. 8 is an enlarged cross-sectional view of an intermediate portion of the medical tube shown in FIG.

FIG. 9 is an enlarged sectional view of a proximal end of the medical tube shown in FIG. 6;

FIG. 10 is a partially omitted enlarged front view of another embodiment in which the medical tube of the present invention is applied to a catheter.

FIG. 11 is an enlarged front view of a distal end portion of the medical tube shown in FIG.

FIG. 12 is an enlarged sectional view of a distal end portion of the medical tube shown in FIG. 10;

FIG. 13 is a partially omitted enlarged front view of another embodiment in which the medical tube of the present invention is applied to a catheter.

FIG. 14 is an enlarged front view of a distal end portion of the medical tube shown in FIG.

FIG. 15 is an enlarged sectional view of the distal end portion of the medical tube shown in FIG.

FIG. 16 is an enlarged front view of a distal end portion in another embodiment in which the medical tube of the present invention is applied to a catheter.

FIG. 17 is an enlarged cross-sectional view of the distal end portion of the medical tube shown in FIG.

FIG. 18 is an explanatory diagram for explaining the method for manufacturing the medical tube.

[Explanation of symbols]

 1, 10, 20, 30 catheter (medical tube) 2 catheter body 3 lumen 4 soft synthetic resin inner layer 5 outer layer 6 distal end 61 groove forming part 7 intermediate part 8 base end part 9 groove 11 hub 41 laser irradiation device

Claims (12)

[Claims] 1. A medical tube comprising a lumen formed therein, an inner layer made of a soft synthetic resin, and an outer layer covering the outer surface of the inner layer and formed of a material harder than the material forming the inner layer. The thickness ratio of the inner layer to the outer layer on the distal side of the medical tube is greater than the thickness ratio of the inner layer to the outer layer on the proximal side of the medical tube, and The medical tube is characterized in that the medical tube has a groove extending from the outer surface of the outer layer toward the lumen at the distal end and having a depth that does not reach the lumen. 2. The medical device according to claim 1, wherein the inner layer is thicker than the outer layer on the distal end side of the medical tube, and the outer layer is thicker than the inner layer on the proximal end side of the medical tube. Medical tube. 3. The medical tube according to claim 1, wherein a bottom surface of the groove has a rounded shape. 4. The medical tube according to claim 1, wherein the groove is formed in a spiral shape. 5. The medical tube according to claim 1, wherein the groove is formed in a ring shape. 6. The medical tube according to claim 4, wherein the pitch of the groove is shorter at a distal end side than at a proximal end side of the tube. 7. The medical tube according to claim 1, wherein at least a part of the groove of the medical tube reaches the inside of the inner layer at a groove bottom portion in a longitudinal direction of the tube. . 8. The medical tube according to claim 1, wherein the medical tube is a catheter. 9. An inner layer made of a soft synthetic resin, and an outer layer made of a material harder than the soft synthetic resin, wherein a thickness ratio of the inner layer to the outer layer at the distal end is greater than the outer layer at the base end. A step of preparing a tubular body having a thickness ratio greater than the thickness ratio of the inner layer, and processing the surface of the tubular body so that at least a part of the tubular body extends from the outer layer surface at the groove bottom portion over the longitudinal direction of the tubular body. Forming a groove having a depth reaching the inner layer and not reaching the inner lumen of the medical tube. 10. The method for producing a medical tube according to claim 9, wherein the step of preparing the tubular body is performed by co-extrusion while changing the discharge amounts of the resin for forming the inner layer and the resin for forming the outer layer. . 11. The method according to claim 9, wherein the step of forming the groove is performed by laser processing. 12. The medical device according to claim 9, wherein in the tubular body, the inner layer is formed thicker on the distal side than the outer layer, and the outer layer is formed thicker on the proximal side than the inner layer. Method for manufacturing tubes.