JPH0615004A - Producing apparatus for rigidity inclination type hollow long member - Google Patents

Abstract

PURPOSE:To prevent the generation of a flaw part of mechanical strength on the surface of a hollow long member inclined in rigidity in its longitudinal direction at the time of production. CONSTITUTION:The emitting ports of first and second polymer supply parts 1, 2 as supply means of polymers different in elastic modulus are connected to the passage F reaching a long land die 5. A fluid supply nozzle 7 emitting a fluid for forming a hollow part is arranged in the polymer supply passage 110 between the confluent part 3 in the passage F of the polymers emitted from the polymer supply means and the first polymer supply part 1. The long land die 5 is constituted so that the inner surface thereof is coated with the molding aid emitted from a molding aid supply part 4. Since the nozzle 7 is arranged on this side of the confluent part 3, a seam line where polymers of a different kind remain is not generated in the obtained long member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for continuously manufacturing a long body whose elastic modulus changes in the longitudinal direction (rigidity inclination), for example, a rigidity inclination type medical catheter.

[0002]

2. Description of the Related Art A preferable example of the use of a rigid slanted hollow elongated body is a catheter which is inserted into the body for the purpose of treatment or diagnosis of the human body or animals. The catheter is required to be easy to be inserted into the body, to prevent damage to cells in the body, and to have a torque transmitting property such that when the root portion is rotated after insertion into the body, the tip portion of the catheter is also rotated. . In order to satisfy such characteristics, the insertion side end portion of the catheter is a flexible portion having appropriate flexibility and elastic modulus, and the root portion is a torque transmitting portion having rigidity enough to transmit torque. If it is a rate change type,
Therefore, the rigid slanted hollow elongated body can be preferably used.

As an apparatus for producing such a hollow elongated body, the present applicant has previously proposed an apparatus as shown in FIG. In the figure, 1 is an extruder for extruding a hard polymer for a torque transmitting portion, 2 is an extruder for extruding a soft polymer for a flexible portion, and the discharge ports of these extruders 1 and 2 are polymers. It is connected via a flow path F to a long land die 5 including a tapered molding portion 51 and a long land portion 52. 3 is a merging portion in the flow passage F of the polymer discharged from the extruders 1 and 2. In the flow passage F downstream of the merging portion 3, a fluid such as water or air for forming a hollow portion is provided. A fluid supply nozzle 7 for discharging is arranged.

In the above apparatus, the flow passage F is formed in such a state that the polymer extruded alternately from the extruders 1 and 2 holds the hollow portion forming fluid discharged from the fluid supply nozzle 7 therein.
And the molding aid supplied from the molding aid supply unit 4 is supplied to the long-land die 5 in a form having the outermost layer. Then, after being molded and cooled in the die 5, it is extruded to form a hard polymer A portion, a soft polymer B portion, and an intermediate portion C in which the component ratio of both is gradually changed as shown in FIG. Thus, the rigid inclined type elongated body having the above can be obtained.

[0005]

Since the elongated body obtained as described above is extruded after being molded and cooled in a long closed pipe line called a longland die, the extruded characteristic and the swelling characteristic are Even if different polymers are extruded alternately, there is an advantage that basically a long body with extremely small variation in outer diameter can be obtained, but when forming a hollow part inside the long body, the following new problems Turned out to be.

That is, as shown in FIG. 5, which is a sectional view taken along the line I--I of FIG. 4, for example, although the polymer is extruded while the supply of the polymer is completely switched from the hard polymer A to the soft polymer B, A seam line of a different polymer is generated on the surface of the elongated body in a state where the hard polymer A remains outside the hollow portion of the obtained elongated body (which is usually called a lumen L in the case of a catheter), There is an inconvenience that the portion becomes a defective portion in terms of mechanical strength with respect to the internal pressure.

[0007]

[Means for Solving the Problems] In order to solve the above problems,
The apparatus for producing a rigid elongated hollow elongated body of the present invention is provided with two or more kinds of polymer supply parts having different elastic moduli, a confluence part where the polymers discharged from each polymer supply part meet, and the confluence part. For forming a hollow portion to be supplied together with the polymer in the longland die, a longing die having a molding zone and a cooling zone, a molding aid supply section for supplying a molding assistant to the inner surface of the longland die. A fluid supply nozzle for supplying a fluid, the fluid supply nozzle
It is characterized in that it is arranged in a polymer supply path connecting the merging section and any one of the polymer supply sections.

[0008]

As a result of the research conducted by the present inventors, it was found that the seam line was formed due to the following phenomenon. That is, as shown in FIG. 6 which is an enlarged view of the vicinity of the fluid supply nozzle 7 of the apparatus of FIG. 3, the normal fluid supply nozzle 7 has the nozzle 7 located at the center of the flow path F, and
A spider 71, which is a pipe for supplying fluid to the nozzle 7, is connected to enable the fluid W to be supplied from the outside into the flow path F. However, since the spider 71 exists in a form traversing the flow path F, the polymer Will interfere with the flow of.

Therefore, even if the supply of the polymer from the extruder is switched from the hard polymer A to the soft polymer B, the hard polymer A remains around the spider 71, particularly in the rear part of the spider 71, and the residual amount of the hard polymer A remains. Gradually flows out with the flow of the soft polymer B, so that a seam line of a different polymer is formed. Since different polymers are adjacent to each other in such a seam line, the adhesion is poor, and therefore mechanically brittle. ,

Therefore, in the present invention, as shown in FIG. 1, the merging portion 3 in the flow channel F of two or more kinds of polymers,
The fluid supply nozzle 7 is arranged between the polymer supply path of either one of the polymer supply sections 1 and 2 (in the flow channel 110 of the polymer supply section 1 and the merging section 3 in the figure), that is, different types. A nozzle 7 is provided in the flow path before the polymer merging portion 3.
Are arranged. With this configuration, even if a polymer residue phenomenon occurs around the spider 71 of the nozzle 7, the seam line formed after bypassing the spider 71 is formed of the same kind of polymer, and therefore the adhesion at the site is improved. Is good, so that no mechanical defects occur in the resulting elongated body.

[0011]

FIG. 1 shows an example of the manufacturing apparatus of the present invention, and the present invention will be described in detail below with reference to the drawings.
In the figure, a first polymer supply part 1 and a second polymer supply part 2 as means for supplying polymers having different elastic moduli.
The discharge port of is connected to the flow path F reaching the long land die 5. Reference numeral 3 denotes a merging portion in the flow path F of the polymer discharged from each of the polymer supply portions, and a polymer supply passage 110 between the merging portion 3 and the first polymer supply portion 1.
A fluid supply nozzle 7 that discharges a fluid for forming a hollow portion is arranged therein. In addition, the inner surface of the long land die 5 is configured to be covered with the molding aid discharged from the molding aid supply unit 4.

In the above apparatus, a first polymer supply section 1 for extruding a polymer in a molten state and a second polymer supply section for extruding a polymer in a molten state which has a different elastic modulus from the first polymer. Polymers alternately discharged from the portion 2 (in this device example, the structure is discharged from the circumference of the flow path F), and discharged from the fluid supply nozzle 7 of the flow path 110 upstream of the confluence part 3 of these polymers. The hollow part forming fluid is continuously supplied together with the molding aid supplied from the molding aid supply part 4 to the longland die 5 in a form in which the fluid is contained in the polymer, and the die 5 It is extruded after being molded and cooled inside.

As the polymer supply parts 1 and 2, an ordinary extruder equipped with an extrusion screw is suitable, and the flow passage F
That is, as the means for alternately supplying the polymer to the long-land die 5, for example, the rotation speed of the extrusion screw is program-controlled to be alternately stopped, or the rotation speed of one extrusion screw is gradually decreased while the other rotation speed is gradually decreased. And a method of increasing the rotation speed of the extrusion screw. In the former case, the length of the intermediate portion (elasticity changing portion) between the first polymer and the second polymer of the extruded elongated body is relatively short, and in the latter case, the length of the elastically changing portion is relatively small. It is long and the length of the elastic change portion can be freely adjusted. In addition to this, as the alternate supply means, a means for providing an electromagnetic valve or the like for controlling the discharge amount at the discharge ports of the polymer supply parts 1 and 2 to the flow path F can be cited.

As the long-land die used in the present invention, one having a taper portion for adjusting the outer diameter and a land portion for forming and cooling is generally mentioned. The land portion is formed by connecting a plurality of undivided dies or divided die pieces each having a circular or irregular cross section,
Alternatively, a non-connection type integrated long die or the like may be used.

The length of the land portion of the long land die is determined by the outer diameter of the finished product, the specific heat of the material, the extrusion temperature,
The finishing outer diameter is generally d
If so, the land length is 30d to 200d, preferably 7
It is 0d to 150d. For example, in the case of a normal human body catheter, the finished outer diameter is about 0.5 mm to 3 mm,
A land length of 35 mm to 450 mm is suitable. A land length within this range is preferable because the polymer can be sufficiently molded and cooled in the die and the extrudability is also good.

In FIG. 1, the long land die 5 comprises a taper portion 51 and a land portion 52, and the land portion 52 is a molding region for making the molten polymer supplied from the polymer supply portions 1 and 2 into a desired outer shape. And a cooling zone for cooling the polymer in order to extrude while maintaining the molded shape. In this case, the taper portion 5 that reduces the outer diameter to a desired value
1 and the inlet portion of the land portion 52 are the molding area, and the remaining portion is the cooling area. Various means can be adopted as the cooling method, and either an air cooling method, a liquid cooling method or the like may be adopted, and a preferable example is to dispose a cooling pipe capable of circulating a refrigerant on the outer periphery of the die. The cooling pipe may be partially arranged so as to cover a part of the land portion, but the cooling pipe may be arranged over the entire land portion.

The fluid supply structure for forming the hollow portion of the elongated body is not particularly limited, but as shown in FIG.
And a fluid supply nozzle 7 located near the center of the cross section of the polymer flow path and having its discharge port arranged toward the longland die 5 side, and a spider 71 that is a pipe body connecting the two. Is preferred. When manufacturing a multi-lumen catheter or the like, a plurality of nozzles 7 may be provided and a plurality of fluids may be independently discharged.
In any case, in order to prevent the formation of the seam line in which the above-mentioned different polymer remains, the merging portion 3 in the channel F is formed.
It is important to arrange the fluid supply nozzle 7 further upstream.

In the present invention, since molding and cooling are carried out in a long-land die, a continuously supplied polymer smoothly advances in the die to obtain a long body having a smooth surface. It is necessary to supply it inside the die. The supply of the molding aid to the inner surface of the die is most preferably supplied so as to cover the entire inner surface of the die without interruption, and any supply means capable of achieving such a supply state can be adopted. For example, slit supply using a minute void such as a die joint, surface supply using a porous body such as porous metal, and the like can be mentioned.

Various polymers can be applied as the polymer used in the present invention, and there is no particular limitation. For example, various elastomers such as ethylene / propylene / diene copolymers, low crystalline organic polymers such as polyvinyl chloride, polyacetal, polyphenylene sulfide, polyamides such as various nylons, polyesters such as polybutylene terephthalate, and various Examples include liquid crystal polymers, highly crystalline organic polymers such as polypropylene, polyolefins such as polybutene-1, and poly-4-methylpentene-1. Among these, two or more kinds of polymers of different types or the same type having different elastic moduli, particularly bending elastic moduli and high compatibility, can be appropriately selected and used.

When the present invention is applied to the production of the above-mentioned medical catheter, examples of the flexible polymer include polyurethane elastomers, polystyrene elastomers, polyester elastomers, polyamide elastomers and chlorinated polyethylene elastomers. Elastomer resin, polyvinyl chloride, polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer and the like can be mentioned. Further, as the polymer for the torque transmitting portion, a liquid crystal polymer such as thermotropic liquid crystal polymer, polyethylene, polypropylene, polyvinyl chloride, polyamide, polyoxymethylene, polycarbonate, polybutylene terephthalate, polyphenylene sulfide, polyether sulfone, polyarylate,
Examples thereof include polyether ether ketone, polyamide imide, and polyether imide. It should be noted that two or more kinds of the above-mentioned polymers may be blended and adjusted to a desired flexural modulus. Further, an X-ray contrast agent such as barium sulfate, bismuth oxide, bismuth subcarbonate, bismuth tungstate, gold, platinum, silver or tungsten may be contained.

In the case of a medical catheter, the polymer for the flexible portion is 0.01 to 50 kgf / mm ² , particularly 0.1 to 10 k when heated to the temperature of the object to be inserted.
A material having an elastic modulus of gf / mm ² is preferable. Further, as the polymer for the torque transmitting portion, any polymer having the required torque transmitting property even under the body temperature of the insertion target may be used, but 20 to 2000 kg in a state of being heated to the body temperature.
A material having a modulus of elasticity of f / mm ² , particularly 50 to 500 kgf / mm ² , can be preferably used.

In addition, in the case of a catheter, the polymer for the flexible portion has a glass transition temperature in the vicinity of the body temperature of the subject to be inserted so that the flexible portion and the torque transmitting portion can function well under insertion into the subject. Polymers having, for example, 29.5 to 43.5 ° C. for the human body, especially 31.5 to
A polymer having a glass transition temperature of about 39.5 ° C.
As the polymer for the torque transmitting portion, it is preferable to select, for example, a polymer having a glass transition temperature higher than the body temperature by at least 10 ° C. or higher, particularly 20 ° C. or higher.

As the molding aid to be supplied into the long-land die, various kinds of lubricants used as a lubricant can be used. Suitable examples include silicone oil and glycol oil. To be Especially 1 ~ 10 ⁴ cp at the temperature in the forming area of Ron Grand die
Those having an oise and a viscosity-temperature characteristic of 10 ² to 10 ⁶ cpoise at room temperature are preferable for allowing the polymer to pass through the die more smoothly. As such a molding aid, dimethyl silicone oil (for example, Toshiba Silicon Co., Ltd., trade name “Toshiba Silicone Oil”, product number TSF451,
YF-33), polyalkylene ether glycol (for example, Nippon Oil & Fats Co., Ltd. trade name "Unilube" product number 75DE-2
620, 75DE-3800) and the like.

As the above-mentioned enclosing fluid for forming the hollow portion, gas such as air, nitrogen, oxygen, helium, carbon dioxide, water, water-soluble liquid, lubricant such as silicone oil or glycol oil is used. Liquids such as can be used.
In particular, if a water-soluble liquid having a boiling point higher than the polymer's extrusion temperature is used, stable extrusion is possible compared with gas, and it is easier to discharge from the hollow part after extrusion, and it can be hollowed by simple cleaning. It is preferable because it has the advantage of being able to clean the inside.

FIG. 2 is a sectional view showing a more specific example of the apparatus for manufacturing a rigid slanted hollow elongated body of the present invention, and the present invention will be described in more detail with reference to this embodiment.
In the figure, a first extruder adapter 11 to which a first extruder (not shown) that extrudes a first polymer 21 (hard material for a torque transmitting portion) is connected, and a second polymer 22 (soft portion for a flexible portion). The respective polymer passages 111 and 121 of the second extruder adapter 12 to which a second extruder (not shown) for extruding the material is connected via the polymer passages 110 and 120 formed in the flow section 30. Then, it is connected to a flow adapter 32 that serves as a merging portion 31 of both polymers.

The flow channel 110 to which the first extruder is connected is
While being linearly connected to the flow path 320 of the flow adapter 32, the flow path 1 is connected to the second extruder.
20 is connected to an annular groove 321 engraved around the flow path 320 of the flow adapter 32. The annular groove 3
21 and the flow path 320 are in communication with each other through the disk-shaped passage 322, so that the second polymer 22 is temporarily stored in the annular groove 321 and passes through the disk-shaped passage 322 to form the flow path 320.
Supplied from around.

The flow path 320 communicates with the taper portion 51 of the long ground die 5 through a passage in the holder 34. Further, a molding aid supply unit 40 is provided at the entrance of the taper portion 51, and the supply unit 40 is composed of a ring-shaped reservoir 41 for temporarily storing the molding aid and a disc-shaped passage 42 communicating with this. In addition, an annular reservoir 4 is provided by a pump (not shown) capable of high-pressure fixed amount supply such as a plunger pump or a gear pump.
1, the molding auxiliary is supplied to the disk-shaped passage 42, and the molding auxiliary is continuously supplied toward the inner peripheral wall of the tapered portion 51.

The land portion 52 of the long ground die 5 is formed by connecting divided dies, and one end thereof is connected in cascade to the taper portion 51. Further, on the circumference of the land portion 52, a water cooling device in which cooling water can be circulated in a cylindrical pipe body is arranged.

Band-shaped electric heaters 6 are arranged on the outer peripheries of the extruder adapters 11 and 12, the flow section 30, the holder 34, and the tapered portion 51, respectively.
The polymer extruded from the extruder by the heat of 1 is maintained in a molten state until reaching the long-land die 5. In addition to the electric heater method using the electric heater described above, a high frequency heating method, a dielectric heating method, or the like can be adopted.

Reference numeral 33 is a nipple, which is provided with a hollow portion forming fluid supply nozzle 7 arranged in the flow path 110 between the first polymer supply portion and the confluence portion 31, and from a nozzle of a gear pump (not shown). The supplied fluid for forming a hollow portion such as silicon oil is discharged in the traveling direction of the polymer. If the spider portion of the nozzle 7 is located upstream of the merging portion 31, it is desirable that the nozzle 7 be as close to the merging portion 31 as possible in order to form a good hollow portion when the second polymer 22 is supplied. Positioning the discharge port of the nozzle 7 near the disc-shaped passage 322 is also a preferred embodiment.

Next, the process of manufacturing a rigid gradient catheter using the apparatus of this embodiment will be described. First, the screw (not shown) of the first extruder is rotated to extrude the torque transmitting polymer 21, and at the same time, the fluid is discharged from the hollow portion forming fluid supply nozzle 7 so that the fluid is held inside. In this state, the first polymer 21 is continuously supplied toward the taper portion 51. Since the inner peripheral walls of the taper portion 51 and the land portion 52 are coated with a molding aid, the polymer 21 smoothly advances in the die and is extruded after being cooled by the water cooling device 53.

After the polymer supply from the first extruder is continued for a predetermined time, the screw of the first extruder is stopped and the screw of the second extruder is rotated to discharge the polymer 22 for the flexible portion. . During this time, the hollow portion forming fluid is continuously discharged from the nozzle 7. Second polymer 22
Is the annular groove 3 of the flow adapter 32 via the flow path 120.
21, the second polymer 22 is supplied from the disc-shaped passage 322 to the confluence portion 31, and instead of the first polymer 21, the second polymer 22 is supplied toward the taper portion 51. Then, it is extruded after being cooled by the land portion 52 in the same manner as described above. Here, when the screw of the first extruder is suddenly stopped and the screw of the second extruder is suddenly started, a catheter whose elastic modulus is rapidly changed can be manufactured. It is possible to manufacture a catheter with a grading middle section.

While the second polymer 22 is being discharged, the first polymer 21 is on standby before the confluence portion 31, but is in a molten state without being solidified by heating by the heater 6. When a predetermined amount of the second polymer 22 is discharged, the screw of the second extruder is stopped and the screw of the first extruder is started.
The first polymer 21 waiting on the front side of No. 1 is supplied again toward the tapered portion 51. At this time, the second polymer 22 waits in the molten state in the annular groove 321 of the flow adapter 32.

By repeating such a cycle, the hollow elongated body whose elastic modulus is alternately changed in the longitudinal direction is continuously extruded, and then cut at a predetermined portion, whereby the torque transmitting portion and the flexible portion are cut. It is possible to obtain a plurality of rigid gradient catheters having

[0035]

As described above, according to the apparatus for manufacturing a rigid slanted hollow elongate body of the present invention as described above, there is no change in outer diameter even when polymers of different elastic modulus having different extrusion characteristics and swelling characteristics are alternately extruded. Not only can a hollow elongated body be obtained, but since the fluid supply nozzle for forming the hollow portion is arranged in the flow path in front of the confluent portion of the different polymers, the heterogeneous polymer is formed on the surface of the obtained hollow elongated body. No seam line remaining is generated, and therefore, a mechanical strength defect is not generated. Furthermore, in the present invention, since the long body is extruded after being cooled in the longland die, that is, since the long body is already in a state of being cooled and solidified, there is an advantage that the long body after extrusion is easy to handle. is there.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of an apparatus of the present invention.

FIG. 2 is a cross-sectional view showing a specific example of the device of the present invention.

FIG. 3 is a cross-sectional view showing an example of a conventional device.

FIG. 4 is a cross-sectional view showing an example of a long body.

FIG. 5 is a cross-sectional view of a long body obtained by a conventional device.

FIG. 6 is an enlarged cross-sectional view of a fluid supply unit of a conventional device.

[Explanation of symbols]

 1 1st polymer supply part 2 2nd polymer supply part 3,31 Merging part 4 Molding aid supply part 5 Rongrand die 51 Tapered part 52 Land part 7 Hollow part formation fluid supply nozzle F Flow path

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kaho Higashimukaijima, Nishinomachi 8 Amagasaki City, Hyogo Prefecture Mitsubishi Electric Wire & Cable Co., Ltd.

Claims (2)

[Claims] 1. A long product having two or more kinds of polymer supply parts having different elastic moduli, a merging part where the polymers discharged from each polymer supply part merge, and a molding zone and a cooling zone connected to the merging section. A land die, a molding aid supply section for supplying a molding aid to the inner surface of the long land die, and a fluid supply nozzle for supplying a hollow portion forming fluid supplied together with the polymer in the long land die. And a fluid supply nozzle arranged in a polymer supply path that connects either the merging portion or the polymer supply portion. 2. A first polymer supply path is linear with respect to the long-land die, and a second polymer or less is provided with a confluent part having a structure in which it is supplied from the periphery of the linear supply path. The fluid supply nozzle is provided with a first
2. The apparatus for manufacturing a rigid slender type elongated body according to claim 1, wherein the apparatus is arranged in the polymer supply path.