JPH1071207A - Manufacturing method of tube for balloon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently manufacture a tube for a balloon that is excellent in the dimensional accuracy such as the thickness and outside diameter. SOLUTION: In this manufacturing method, a reactive polymer composition is injected into the lumen of a cylindrical tube from the one end of the cylindrical tube 1, and then a bar-shaped body 2 is inserted into the lumen from the one end of the cylindrical tube 1, and they are installed so that the axis of the bar-shaped body 2 is brought into line with the axis of the lumen. The composition is filled in the space formed between the inside wall of the cylindrical tube 1 and the outside wall of the bar-shaped body 2, and then the composition is subjected to reaction and solidified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a balloon tube. More specifically, the present invention relates to a method for manufacturing a balloon tube having excellent dimensional accuracy such as thickness and outer diameter.

[0002]

2. Description of the Related Art A balloon used in a balloon catheter is formed in a thin tube shape. The thin tube (balloon tube) is fixed to the catheter tube such that both ends cover side holes of the catheter tube. In balloon catheters, the balloon is inflated or deflated by fluid flowing in or out through the side hole. If the film thickness of the balloon tube is uneven, the balloon expands into a flat shape. Conventionally,
The balloon tube is formed by dip molding or extrusion molding. However, when using a dip molding method for a small tube such as a balloon tube,
The film thickness accuracy is low, and a thickness deviation of about 20 to 50% tends to occur.
Also, the stock of the polymer liquid for dipping increases, which makes it unsuitable for small-quantity multi-product production. On the other hand, in the extrusion molding method, it is not easy to control the viscosity of the reactive polymer composition, and it is difficult to adjust the film thickness. In addition, although small tubes such as balloon tubes can be produced in large quantities, they are not suitable for small-quantity multi-product production. On the other hand, there is a method using a mold as a method for producing a molded product. However, in the molding of the reactive polymer composition using the conventional mold, the mold must be occupied until the composition is solidified, and the occupation time of the mold is increased, and the molding cost is increased. Further, when the solidified composition is released from the mold, the mold is easily damaged.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for efficiently producing a balloon tube having excellent dimensional accuracy such as thickness and outer diameter. The present inventors have made intensive studies to achieve the above object,
The rod is positioned so that the axis of the rod coincides with the axis of the lumen so that the composition fills the space created between the inner wall of the circular tube and the outer wall of the rod, and then the composition is It has been found that the above object can be achieved by reacting and solidifying, or by attaching a reactive polymer composition to the inner wall of a circular tube and reacting and solidifying the composition while rotating around the long axis of the circular tube. The present invention has been completed based on the findings.

[0004]

Thus, according to the present invention, (1) the surface of a rod is coated with a reactive polymer composition, and then the rod is inserted into the lumen from one end of a circular tube. The rod is positioned so that the axis of the rod coincides with the axis of the lumen, so that the composition is filled in the space formed between the inner wall of the circular tube and the outer wall of the rod, and A method for producing a tube for a balloon is provided, wherein the composition is reacted and solidified.

According to the present invention, (2) the reactive polymer composition is injected into the lumen of the circular tube from one end of the circular tube, and then the rod is inserted into the lumen from one end of the circular tube. The rod is positioned so that the axis of the rod coincides with the axis of the lumen so that the composition fills the space created between the inner wall of the circular tube and the outer wall of the rod, and then the composition is A method for producing a balloon tube is provided, which comprises reacting and solidifying.

According to the present invention, the circular pipe is inserted into a fixed container which is in close contact with the outer peripheral surface of the circular pipe.
Alternatively, the production method according to (2) is provided.

Further, according to the present invention, the reactive polymer composition is injected into a circular tube, and the composition is rotated around the long axis of the circular tube, and the composition is cast on the inner wall surface of the circular tube by centrifugal force or gravity. While the composition is reacted and solidified, a process for producing a balloon tube is provided.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing a balloon tube of the present invention is to inject a reactive polymer composition into a specific mold and to solidify the reaction.

A reactive polymer composition is a composition in which a reactive group is bonded to a molecular chain and the functional group reacts with and binds to another functional group or compound to crosslink or extend the molecular chain. It is.

Specific examples of the reactive polymer composition include:
A composition comprising a urethane prepolymer having an isocyanate group or a block isocyanate group, and an extender such as water, polyol, or polyamine; a composition comprising a radical crosslinkable urethane prepolymer and a peroxide A one-part reaction type silicone prepolymer; a two-part reaction type silicone prepolymer; a mixture of a reaction initiator and a (meth) acrylate-based monomer, an oligomer thereof, or a (meth) acrylate-based macromonomer; a prepolymer having epoxy groups at both ends. A mixture of a polymer and an amine-based elongating agent is exemplified. Among these, a composition comprising a urethane prepolymer and an elongation agent is preferable from the viewpoint of antithrombotic properties, strength, permanent elongation, and the like.

The viscosity of the composition used in the present invention is usually 3
00 to 300,000 cp, preferably 1000 to 100
000 cp. If the viscosity is high, it is difficult to fill the composition between the circular tube and the rod-like body, and if the viscosity is low, liquid leakage easily occurs from the mold. Here, the viscosity is 3
It is a value measured by a Brookfield viscometer under the condition of 0 to 150 ° C.

The mold used in the manufacturing method of the present invention is a circular tube. The inner diameter of the circular tube is usually 0.5 to 10 mm, preferably 1.
5-5 mm, the length of the circular tube is usually 10-400 mm,
Preferably it is 50 to 300 mm. The material of the circular tube is not particularly limited, but it is preferable that at least the inner wall surface of the circular tube is smooth to prevent the polymer after the reaction and solidification from sticking to the inner wall surface of the circular tube. To smooth the inner wall surface, the entire pipe is made of fluororesin, silicone, ultra high molecular weight polyethylene, polypropylene, etc., or the inner wall of the pipe made of other resin or metal is made of fluororesin, silicone, It is preferable to coat with high molecular weight polyethylene, polypropylene or the like. The surface dynamic friction coefficient of the smooth surface is usually set to 0.3 or less.

[0013] In the first production method of the present invention, the composition is poured into a circular tube, a rod is inserted into the lumen from one end of the circular tube, and the composition is applied to the inner wall of the circular tube by the rod. And the space between the outer wall of the rod and
The portion occupied by the rod forms the lumen of the balloon tube.

The rod is placed so that its axis coincides with the axis of the tubular lumen. In order to match the axes of the rod and the circular tube, a bearing for receiving and fixing the tip of the rod at the other end of the circular tube is installed, and after inserting the rod into the lumen of the circular tube, It is preferable to install a bearing similar to the bearing at one end of the tube.

By providing bearings at both ends of the circular pipe,
Since the axial center of the rod-shaped body and the axial center of the circular tube are easily aligned, the dimensional accuracy of the thickness of the balloon tube obtained by this method is increased. The bearing preferably serves as a lid for closing both ends of the circular tube. The composition can be prevented from leaking from both ends of the circular tube. Also, the bearing is a material that is easy to peel off after the composition is solidified, usually,
It is preferable to be formed of a material having a surface dynamic frictional resistance coefficient of 0.3 or less. Specifically, a material obtained by coating a fluorine resin or silicone on stainless steel or the like can be used.

The outer diameter of the rod is usually 0.5 to
It is 9.9 mm and the length is 15 to 500 mm. The material of the rod-shaped body may be any material that is easy to peel off after the composition is solidified, and examples thereof include a fluororesin and a metal rod surface coated with a fluororesin.

In the second production method of the present invention, a rod-shaped body is coated with the composition, the rod-shaped body is inserted into the lumen from one end of a circular tube, and the composition is applied to the inner wall of the circular tube by the rod-shaped body. The space between the rod and the outer wall of the rod is filled, and the portion occupied by the rod forms the lumen of the balloon tube.

The rod is set so that its axis coincides with the axis of the lumen of the circular tube. At least two tube-shaped spacers having the same outer diameter as the inner diameter of the circular pipe are closely fitted to the rod-shaped body at regular intervals in the longitudinal direction of the rod-shaped body in order to match the axes of the rod-shaped body and the circular pipe. Is preferred. The axial center of the circular tube and the axial center of the rod can be matched by the spacer closely fitted to the rod-shaped body, and the space formed by the two spacers can be filled with the reactive polymer composition, and The thickness of the spacer is accurately adjusted by the tube thickness of the spacer. As the spacer and the rod-shaped body, those having a small surface dynamic frictional resistance such as a fluororesin, usually 0.3 or less are preferably used similarly to the above-mentioned bearing and the rod-shaped body.

In order to coat the rod-shaped body with the reactive polymer composition, the rod-shaped body is immersed in the reactive polymer composition, or the reactive polymer composition is dropped on the rod-shaped body.

In the first or second production method of the present invention, it is preferable that the circular tube is inserted into a fixed container having an inner surface that is in close contact with the outer peripheral surface of the circular tube. This method can reduce the wall thickness unevenness and the flatness. Examples of the fixed container include a tube having the same inner diameter as the outer diameter of the circular tube, a container in which a column having the same inner diameter as the outer diameter of the circular tube is hollowed out, and the like. The material may be a material having such a strength that the circular tube does not expand or bend due to the internal pressure, and examples thereof include metals such as stainless steel, and resins such as polycarbonate and high-density polyethylene.

In the third production method of the present invention, the composition is poured into a circular tube, and the composition is rotated around the long axis of the circular tube, and the composition is cast on the inner wall surface of the circular tube by centrifugal force or gravity. .

The rotation speed of the circular tube is not particularly limited, but may be any value as long as the composition is cast on the inner wall surface of the circular tube and a space is created near the central axis of the circular tube. The space near the central axis becomes the lumen of the balloon tube.

The composition is injected into a circular tube, a rod is inserted or the circular tube is rotated so that the reactive composition is ubiquitous on the inner wall surface of the circular tube, and the composition is reacted. Solidify. To react and solidify the composition, the composition may be left at room temperature as it is, but usually heated to promote the reaction.

In the production method of the present invention, the heating temperature varies depending on the type of the reactive polymer composition, but is usually 50 to 50.
The temperature is 200 ° C, preferably 90 to 130 ° C. The heating time varies depending on the heating temperature, but is usually from 10 minutes to 3 minutes.
Days, preferably 1 hour to 48 hours. Insufficient heating (low temperature, short time) causes insufficient strength and permanent elongation as a polymer. Excessive heating (high temperature, long time) deteriorates the polymer, lowers the strength due to decomposition, permanent This leads to an increase in elongation.

After the composition is solidified, it is usually released from the mold.
When the pipe or rod is made of resin,
Since the mold is inexpensive, the mold can be easily removed by stretching or breaking a circular tube or a rod.

[0026]

EXAMPLES The production method of the present invention will be described in more detail with reference to examples. Note that the present invention is not limited to the following embodiments.

The evaluation method performed in the present embodiment will be described below. [Evaluation of Accuracy of Wall Thickness and Inner Diameter] A portion having a length of about 0.5 mm was cut out from both ends of the balloon tube to obtain a ring-shaped test piece.
A magnified photograph of 0 times is taken, the maximum inner diameter and the minimum inner diameter, and the maximum thickness and the minimum thickness are measured. From these measured values, the uneven thickness ratio = ((maximum thickness) − (minimum thickness)) / (Maximum thickness) ×
100 [%] and flattening ratio = ((maximum inner diameter)-(minimum inner diameter)) / (maximum inner diameter) x 100 [%].

Embodiment 1 FIG. 1 is a sectional view of a mold used in Embodiment 1. The mold used in this embodiment includes a circular tube 1, a rod 2, a first bearing 3, and a second bearing 4. The circular tube has an outer diameter of 3.1 mm, an inner diameter of 2.3 mm, and a length of 100 mm, and is entirely formed of a fluororesin. The outer diameter of the rod is 1.9m
m, length 120 mm, made of stainless steel, and covered with fluororesin.

MDI 50 mmol and number average molecular weight 10
The resulting mixture was reacted with 25 mmol of polytetramethylene glycol to give a urethane prepolymer. A composition comprising 18.5 mmol of polytetramethylene glycol having a number average molecular weight of 1,000, 3 mmol of 1,4-butanediol and 1 mmol of trimethylolpropane is added to the urethane prepolymer, mixed, and the reactive polymer composition is obtained. The reactive polymer composition is injected into a circular tube, and after the injection, the second bearing is installed at the other end of the circular tube, and the rod is inserted from one end of the circular tube, and the rod is inserted into the second bearing. Insert the tip of the rod, fix the tip of the rod, then insert the rear end of the rod into the first bearing, fix the rear end of the rod, and install the first bearing at one end of the circular tube did.

Next, the mold was left in an oven at 110 ° C. for 24 hours to allow the reactive polymer composition in the mold to react and solidify. The mold is removed from the oven, the circular tube is stretched by grasping both ends of the circular tube, the inner wall of the circular tube is separated from the outer wall surface of the solidified product, the solidified product is taken out from the circular tube, and the solidified product is added to ethanol for 10 minutes. The rod was immersed for a minute to swell, and the rod was removed from the solidified material. The demolded solid was left in a dryer at 80 ° C. for 4 hours, and then cut into a length of 5 cm to obtain a balloon tube. The unevenness ratio of the balloon tube is 9
% And the flattening rate were 5%.

Embodiment 2 FIG. 2 is a sectional view of a mold used in Embodiment 2. The mold used in this example is a circular tube 21, a rod 22, and a spacer 23.
Consists of The circular pipe has an outer diameter of 3.1 mm and an inner diameter of 2.3.
mm and a length of 300 mm, and is entirely formed of a fluororesin. The rod has an outer diameter of 1.9 mm and a length of 3
It is 20 mm, made of stainless steel, and its surface is covered with a fluororesin. A spacer is closely fitted to this rod-shaped body.

MDI 50 mmol and number average molecular weight 10
The resulting mixture was reacted with 25 mmol of polytetramethylene glycol to give a urethane prepolymer. A composition comprising 18.5 mmol of polytetramethylene glycol having a number average molecular weight of 1,000, 3 mmol of 1,4-butanediol and 1 mmol of trimethylolpropane is added to the urethane prepolymer, mixed, and the reactive polymer composition is obtained. Was obtained, the reactive polymer composition was hung on the surface of the rod to coat the rod, and the rod was inserted into a circular tube. The circular tube and the rod-shaped body were fixed by the spacers so that their axes coincided with each other.

Next, the mold was left in an oven at 110 ° C. for 24 hours to allow the reactive polymer composition in the mold to react and solidify. The mold is taken out of the oven, the circular tube is stretched by grasping both ends of the circular tube, the inner wall of the circular tube is separated from the outer wall surface of the solidified product, the solidified product is taken out from the circular tube, and the solidified product is added to ethanol for 10 minutes. The rod was immersed for a minute to swell, and the rod was removed from the solidified material. The demolded solid was left in a dryer at 80 ° C. for 4 hours, and then cut into a length of 5 cm to obtain a balloon tube. The unevenness ratio of the balloon tube is 9
%, And the flattening rate was 4%.

Third Embodiment FIG. 3 is a perspective view of an apparatus used in a third embodiment. The mold used for this device consists of a circular tube. The outer diameter of the circular pipe is 2.5m
m, inner diameter 2.3 mm, length 130 mm, made entirely of stainless steel, and coated on its inner surface with fluororesin. A composition composed of a urethane prepolymer and an elongation agent was injected into this circular tube in the same manner as in Example 1. Both ends of the circular tube are closed with rubber stoppers, an injection needle is inserted into the rubber stopper, and the inside air is suctioned with a syringe to reduce the pressure inside. Then
The circular tube was rotated by placing the circular tube between two rollers of the apparatus shown in FIG. 3 and slowly rotating the two rollers. After the composition injected into the circular tube is uniformly cast on the inner wall of the circular tube and a space is formed near the central axis of the circular tube, while rotating the circular tube, 120 ° C. hot air is applied to the circular tube for 1 hour.
The air was blown for 5 minutes to cause the urethane prepolymer in the circular tube to react with the elongating agent and to be solidified. Then, it was left in an oven at 110 ° C. for 24 hours to complete the elongation reaction. The circular tube is removed from the apparatus, the circular tube is stretched by grasping both ends of the circular tube, the inner wall of the circular tube is separated from the outer wall surface of the solidified product, and the solidified product is removed from the circular tube to obtain a balloon tube. Was. The unevenness ratio of the balloon tube was 10%, and the flatness ratio was 3%.

Comparative Example The reactive polymer composition used in Example 1 was replaced with an outer diameter of 1.9.
mm, into a rod with a length of 500 mm, by immersion molding method,
After being coated, it was heated in the same manner as in Example 1 to obtain a dip molded product. The unevenness ratio of this molded tube was 20%, and the flatness ratio was 5%.

Example 4 The circular tube used in Example 1 was 3.1 mm in inner diameter and 2 mm in thickness.
The balloon tube was obtained in the same manner as in Example 1 by inserting it into a fixed container made of a stainless steel straight tube having a length of 100 mm and a length of 100 mm. The tube had a wall thickness variation of 7% and a flatness of 3%.

Example 5 The circular tube used in Example 2 had an inner diameter of 3.1 mm and a thickness of 2 mm.
A balloon tube was obtained in the same manner as in Example 2 by inserting it into a fixed container made of polycarbonate in which a plurality of cylindrical holes having a depth of 300 mm and a depth of 300 mm were cut out. The tube had a wall thickness variation of 5% and a flatness of 3%.

[0038]

According to the production method of the present invention, a balloon tube having high dimensional accuracy such as wall thickness and outer diameter can be obtained. In addition, the use of a fluororesin circular tube in the present invention makes it easy to remove the mold.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a mold used in the manufacturing method shown in Embodiment 1.

FIG. 2 is a cross-sectional view of a mold used in the manufacturing method shown in Embodiment 2.

FIG. 3 is a perspective view of a rotating device used in a manufacturing method according to a third embodiment.

[Explanation of symbols]

 1,21..circular pipe 2,22..bar 23..spacer 3..first bearing 4..second bearing

Claims (4)

[Claims] 1. A reactive polymer composition is injected into a lumen of a circular tube from one end of a circular tube, and then a rod is inserted into the lumen from one end of the circular tube so that the axis of the rod is a lumen. Is disposed so as to coincide with the axis of the rod, so that the composition is filled in a space formed between the inner wall of the circular tube and the outer wall of the rod-shaped body, and then the composition is reacted and solidified. Method for manufacturing a balloon tube. 2. The surface of a rod is coated with a reactive polymer composition, and then the rod is inserted into the lumen from one end of a circular tube so that the axis of the rod coincides with the axis of the lumen. So that the composition is filled in the space formed between the inner wall of the circular tube and the outer wall of the rod-shaped body, and then the composition is reacted and solidified. Recipe. 3. Injecting the reactive polymer composition into a circular tube, rotating the tube around the long axis of the circular tube, casting the composition on the inner wall surface of the circular tube by centrifugal force or gravity, and further adding the composition. A method for producing a tube for a balloon, comprising reacting and solidifying. 4. The method according to claim 1, wherein the circular tube is inserted into a fixed container that is in close contact with the outer peripheral surface of the circular tube.