JPH0352301B2 - - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to a method of manufacturing a balloon catheter having a partially spherically inflatable gap.

(Prior Art and its Problems) This type of balloon catheter is used as an indwelling catheter for urinary drainage, a cardiac catheter, an intraventricular catheter, or the like. Conventionally, this balloon catheter has been manufactured by separately manufacturing an inflation balloon in advance, encasing it so as to surround one circumference of the catheter body, and then applying adhesive to both ends of the balloon, or applying adhesive to both ends of the balloon. A known method is to glue and fix the balloon to the catheter by tying it with thread from the outside, and then further covering the balloon with latex rubber or the like from the outside. In addition, after attaching the pre-manufactured balloon part to the catheter body, adhesive is applied to the entire catheter.
A method is also known in which latex rubber is bonded to the outside of the rubber layer to improve the adhesion between the inner rubber and the outer rubber layer.

However, in the balloon catheter made by the conventional method as described above, after the initially formed inner rubber layer has almost solidified, when the balloon section is inflated to further adhere the latex rubber to the outside, both ends of the balloon are As a starting point, delamination tends to occur between the inner rubber layer formed first and the outer rubber layer formed later, which may cause the balloon to lose its inflated shape and not function as a balloon. Since the pre-manufactured balloon is interposed between the inner rubber layer and the outer rubber layer of the catheter, even when the balloon is not inflated, the balloon part protrudes compared to other parts, which may impede the introduction of the catheter. In addition, the manufacturing process is relatively complicated and takes a long time, as it requires attaching a pre-manufactured balloon to the catheter body.

In order to solve these problems, various proposals have been made (for example, the techniques disclosed in Japanese Patent Publications No. 52-43032 and No. 52-43033). Although satisfactory balloon catheters can be manufactured using such techniques, there has been a desire to develop a highly reliable balloon catheter that is easier to manufacture and does not cause any problems such as delamination.

Purpose of the Invention The present invention was made in view of the above-mentioned circumstances.The purpose of the present invention is to simplify manufacturing, eliminate the risk of delamination as described above during balloon inflation, and further improve the balloon inflation. A balloon catheter in which the lumen for the catheter is uniformly formed, and when the balloon is not inflated, the balloon part is formed to have the same outer diameter as other parts without protruding compared to other parts, and the catheter can be introduced smoothly. The purpose of this invention is to provide a method for manufacturing the same.

According to the present invention, when manufacturing a balloon catheter, (a) a latex rubber coagulant made of an alcoholic solution of a divalent or trivalent metal salt is coated on a rod-shaped mold 1 for forming a conduction path of the catheter; After that, it is dipped in a latex rubber solution and dried.
(b) Applying a solution of water, latex rubber, surfactant, and divalent or trivalent metal salt mixed in an emulsion state to the first latex rubber layer 2; (c) A latex rubber coagulant for thin rod-shaped molds is applied to the thin rod-shaped mold 3 for forming a passage communicating with the balloon part, and a branch part for forming a branch conduction passage communicating with the passage communicating with the balloon part. After the latex rubber coagulant for forming the branch part is applied to the molding die 5, the thin rod-shaped die 3 is placed along the rod-shaped die 1, and its tip is moved slightly back from the front end of the rod-shaped die 1. (d) The tip of the thin rod-shaped mold 3 and the vicinity thereof. After depositing the gap forming material 7 for forming a balloon on the circumference of the balloon, the whole is immersed in a latex rubber solution again and dried to form a second latex rubber layer 8, (e) Finally, the above-mentioned The above objective can be achieved by removing the rod-shaped mold 1, the branch forming mold 5, and the thin rod-shaped mold 3.

The latex rubber coagulant for the thin rod-shaped mold is
A volatile solution of silicone and a lower alcohol solution of a divalent or trivalent metal salt are preferably used.
The latex rubber coagulant for forming the branched portion is preferably a latex rubber coagulant prepared by mixing latex rubber, a surfactant, and a divalent or trivalent metal salt in water in the form of an emulsion. Further, the gap-forming substance 7 is preferably a mixed solution of a volatile solution of silicone and a lower alcohol solution of a divalent or trivalent metal salt.

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the method for manufacturing a balloon catheter of the present invention will be described in detail with reference to the accompanying drawings.

A feature of the present invention is to manufacture a balloon catheter that is easy to manufacture, highly reliable, and free from delamination by selectively using coagulants having different compositions depending on the purpose of each step. Various materials such as each coagulant will be described in detail later. In addition, in the following explanation, a balloon catheter having four rubber layers will be described.
It is not limited to this.

First, as shown in Fig. 1, in order to form injection holes for liquid drainage or chemical liquid, a rod-shaped mold 1 is coated with a latex rubber coagulant made of an alcoholic solution of a divalent or trivalent metal salt, and then the latex rubber liquid is coated. By dipping, a first latex rubber layer (hereinafter referred to as the first rubber layer) 2 is formed on the peripheral surface of the mold 1.
form. On this first rubber layer 2, latex rubber, a surfactant, and a divalent or trivalent metal salt are added to improve adhesion with the next rubber layer, that is, to prevent peeling between the rubber layers. An emulsion solution (hereinafter simply referred to as an anti-delamination agent for convenience) is applied.

Next, a thin rod-shaped mold 3 for forming a passage for inflating or deflating the balloon is filled with a latex rubber coagulant for thin rod-shaped molds, preferably a volatile solution of silicone, and a divalent or trivalent metal salt. A latex rubber coagulant for thin rod-shaped molds, which is a mixture with a lower alcohol solution, is applied, and preferably a volatile silicone solution is applied to the tip 4 to prevent the latex rubber from adhering. Further, a latex rubber coagulant for forming a branch part, preferably a latex rubber and an aqueous solution of a divalent or trivalent metal salt are placed in an emulsion state in a mold 5 for forming a branch part to form a branch conduction path leading to the passage communicating with the balloon. Apply the latex rubber coagulant for branch formation mixed in step. The thin rod-shaped mold 3 and the branch forming mold 5 are placed on the first rubber layer 2 on the mold 1, as shown in FIG. That is, the thin rod-shaped molds 3 are placed on the mold 1 with their tips 4 set back from the tip of the mold 1 by a distance that allows the formation of a balloon, and branched in a lined state as shown in FIG. The part forming mold 5 is appropriately disposed so that a branch part is formed following the thin bar-shaped mold 3.

Thereafter, by immersing them in a latex rubber solution, as shown in FIG. 2, an auxiliary rubber layer 6 is formed except for the thin rod-shaped mold tip 4 (which becomes the opening to the balloon). Preferably, the auxiliary rubber layer 6 is coated with the above-mentioned delamination prevention agent.

Next, a gap-forming substance, preferably a volatile solution of silicone and a lower alcohol solution of a divalent or trivalent metal salt, is applied to a width corresponding to the size of the balloon to be formed near the tip of the thin rod-shaped mold 3. After applying a certain gap-forming substance 7, the whole is immersed in a latex rubber liquid to form a second latex rubber layer (hereinafter referred to as the second rubber layer) 8, as shown in FIG. do. Preferably, the second rubber layer 8 is coated with a delamination prevention agent. Note that the delamination preventing agent may be applied between each layer, or may be applied only between necessary layers. When the number of layers is small, it is not necessary to apply it.

Further, in order to prevent the quality of the balloon inflating portion 9 from being deteriorated by pinholes, etc., the third latex rubber layer 10 is preferably further immersed in a latex rubber solution as shown in FIG. form.

In the illustrated example, the auxiliary rubber layer 6 is provided under the second rubber layer 8, and the third rubber layer 10 is further formed on the second rubber layer 8 to form a four-layer structure, but as described above, The present invention is not limited to this, but includes a configuration in which the auxiliary rubber layer 6 is not formed and the gap-forming substance is placed in a predetermined position to form the second rubber layer, and a configuration in which the third rubber layer 10 is not provided. , furthermore, 4
Of course, a multi-layer structure with more than one layer is possible.

Thereafter, the rod-shaped mold 1, thin rod-shaped mold 3, and branch part forming mold 5 are removed from the four-layer latex rubber molded body, and the rubber molded body is subjected to necessary treatments such as vulcanization to form a balloon catheter. Completed manufacturing.

Various materials used in the manufacturing process as described above will be explained in detail.

(1) Latex Rubber The latex rubber used in the present invention is liquid, and various types of natural latex rubber or synthetic latex rubber such as styrene-butadiene rubber, acrylonitrile-butadiene rubber, recycled rubber, and isoprene rubber can be used. Further, to this latex rubber, powdered sulfur, colloidal sulfur, etc. are added as a vulcanizing agent, diethyldithiocarbamate, etc. are added as a vulcanization accelerator, and milk casein, potassium hydroxide, a surfactant, etc. are added as a thickening agent.

(2) Latex rubber coagulant to be applied to the rod-shaped mold This is an alcoholic solution of divalent or trivalent metal salts, and the purpose of applying this is to coagulate the latex rubber adhered to the rod-shaped mold and form a latex rubber layer. This is for forming (first rubber layer 2). As the divalent or trivalent metal salt, calcium nitrate, barium nitrate, calcium chloride, barium chloride, aluminum sulfate, etc. can be used. Further, as the solvent, alcohols, particularly lower alcohols such as methanol and ethanol, and mixed solutions thereof are used. Further, if necessary, a wetting agent is appropriately added so that the coagulant adheres uniformly to the rod-shaped mold. As a wetting agent, an alkylaryl sulfonate or the like can be used.

Further, the mixing ratio of the divalent or trivalent metal salt and the alcohol varies depending on the thickness of the latex rubber to be obtained by immersing it in the latex rubber solution. Therefore, when the wall thickness is increased, the weight ratio of the metal salt becomes higher.

(3) Latex rubber coagulant for thin rod-shaped molds applied to thin rod-shaped molds The thin rod-shaped molds are used to form fluid conduction paths to the balloon in the thin latex rubber layer. The above-mentioned coagulant applied to the rod-shaped mold can also be used, but since this conduction path is narrow, in order to ensure sufficient lumen, it is necessary to consider the ability of latex rubber to build up on the thin rod-shaped mold and the rubber layer of the thin rod-shaped mold. It is preferable that the mold releasability is high so that it can be removed without damage, and the coagulants described below are preferable. A preferred coagulant is a coagulant made of a mixed solution of a volatile silicone solution, a divalent or trivalent metal salt, and a lower alcohol solution.

This coagulant consists of a volatile solution of silicone and two
It is a mixture of a valent or trivalent metal salt and a lower alcohol solution in a ratio of 3:2 to 4:1. Volatile silicone solutions impart mold release properties due to their latexophobic properties, while divalent or trivalent metal salts and lower alcohol solutions have excellent rubber molecule aggregation ability and impart build-up properties. be. Therefore, the mixing ratio of these silicone volatile solutions, divalent or trivalent metal salts, and lower alcohol solutions should be limited to the above range. The reason for this is that if the ratio of silicone volatile solution to divalent or trivalent metal salt and lower alcohol solution exceeds 4:1, the water repellent effect is strong and the build-up properties are not satisfied; This is because mold releasability is not satisfied if it is less than 20%.

The ingredients and composition of the silicone volatile solution, divalent or trivalent metal salt, and lower alcohol solution are preferably as follows.

(1) Volatile solution of silicone (1-1) Components Silicone oil...Dimethyl-based, phenylmethyl-based silicone oil, specifically dimethyl silicone oil, methyl phenyl silicone oil, methyl chlorophenyl silicone oil, Branched methyl silicone oil, methyl hydrogen silicone oil Volatile liquids...benzene, toluene, THF,
Chloroform, ethyl ether, gasoline,
Acetone etc. (1-2) Composition This solution contains 10 to 100% of silicone oil.
A composition of 30 w/w% is preferred.
If the concentration is lower than 10w/w%, divalent or trivalent
The amount of silicone is small compared to the total amount when mixed with the alcohol solution of the valent metal salt, and sufficient mold releasability cannot be provided. Moreover, if the concentration is so high as to exceed 30 w/w%, water repellency will be high and build-up properties will be poor. Furthermore, the viscosity becomes high and the miscibility with alcohol solutions of divalent or trivalent metal salts becomes poor.

(2) Lower alcohol solution of divalent or trivalent metal salt (2-1) Ingredients Metal salts...calcium nitrate, calcium chloride, calcium acetate, barium chloride, barium nitrate, barium acetate, magnesium chloride,
Zinc chloride, zinc nitrate, zinc acetate, aluminum sulfate, etc. Lower alcohols...Alcohols that are liquid at room temperature such as methanol and ethanol (2-2) Composition This solution contains 30 to 60 w/w% of the above metal salts.
It is preferable that the composition is as follows. If the concentration is lower than 30 w/w%, when mixed with a volatile silicone solution, the amount of metal salt will be small compared to the total amount, and sufficient build-up properties will not be obtained. Also 60w/
If the concentration is so high as to exceed w%, it becomes difficult to mix uniformly into the volatile silicone solution, resulting in uneven build-up and poor mold releasability.

(4) Latex rubber coagulant for forming branch parts applied to mold for forming branch parts The mold for forming branch parts is used together with a thin rod-shaped mold, and is used to branch the conductive path formed by the thin rod-shaped mold. used. The coagulant applied to this can be the same as that used for the rod-shaped mold described above, but a non-hygroscopic one is preferable from the viewpoint of build-up properties and ease of molding work, and the following coagulants are suitable. be.

It is preferable to use a coagulant for latex rubber, which is prepared by mixing latex rubber, a surfactant, and a divalent or trivalent metal salt in water in an emulsion state. Latex rubber is liquid and
Various natural latex rubbers or synthetic latex rubbers such as styrene-butadiene rubber, acrylonitrile-butadiene rubber, recycled rubber, isoprene rubber, etc. can be used. Furthermore, this latex rubber contains powdered sulfur, colloidal sulfur, etc. as a vulcanizing agent, and diethyldithiocarbamate, etc. as a vulcanization accelerator.
Milk casein or the like is appropriately added as a thickener.

Surfactants include anionic surfactants such as fatty acid salts, higher alcohol sulfate ester salts, liquid fatty oil sulfate ester salts, sulfates of aliphatic amines and aliphatic amides, nonionic ether sulfate ester salts, and alkylaryl sulfones. Cationic surfactants include aliphatic amine salts, quaternary ammonium salts, alkylpyridinium salts, etc. Amphoteric surfactants include imidazoline derivatives, higher alkylaminos, and sulfuric esters. Specifically, there is long-chain aliphatic betaine.
Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenol ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, and polyoxyethylene sorbitan alkyl esters.

Further, as the divalent or trivalent metal salt, suitable chlorides include barium chloride, calcium chloride, and nitrates include barium nitrate, calcium nitrate, and aluminum sulfate.

Next, a method for mixing this coagulant in an emulsion state will be explained.

Latex rubber and water are mixed in a first container to create a latex rubber solution of the required concentration.

Next, a required amount of an aqueous surfactant solution is added to the latex rubber solution and stirred thoroughly. Then the second
The coagulant for latex rubber of the present invention can be produced by gradually adding the latex rubber solution to which the above-mentioned surfactant aqueous solution has been added into a container while stirring an aqueous solution of a divalent metal salt, thereby mixing in an emulsion state. can. The reason for using such a method is that divalent metal salts are originally coagulants for latex rubber, and when mixed with a latex rubber solution, the rubber coagulates. Therefore, by adding a surfactant to a latex rubber solution to form a film of the surfactant on the rubber surface, and gradually adding it to an aqueous divalent metal salt solution while stirring, the latex rubber solidifies. It is possible to obtain a mixture in the form of an emulsion.

Next, the composition ratio of each component of the coagulant for latex rubber for forming branched portions will be explained. First, the amount of surfactant is determined by the amount of latex rubber. As mentioned above, the surfactant forms a film on the latex rubber, so as the amount of latex rubber increases, the amount of surfactant required also increases. The weight ratio of latex rubber to surfactant is in the range of 20:1 to 200:1, preferably 25:1 to 150:1. If the amount of surfactant exceeds 200:1, it will not be possible to form a film over the entire latex rubber, and there is a risk that the latex rubber will partially coagulate when mixed in an aqueous divalent metal salt solution. In addition, if the amount of surfactant exceeds 20:1, the tackiness of the latex rubber solution to which the latex rubber solution is later immersed and adhered may deteriorate, and the molded latex rubber tube may peel off.

Further, the concentration of the latex rubber aqueous solution varies depending on the required thickness of the latex rubber to be dipped and adhered next. If more wall thickness is required, the concentration of the latex rubber solution will be higher. Therefore, the concentration differs depending on the purpose and is not uniquely determined. Next, the concentration of the divalent or trivalent metal salt aqueous solution will be explained. The concentration of this aqueous solution also varies depending on the required wall thickness of the latex rubber to be subsequently dipped and deposited. That is, when a thick wall thickness is required, the concentration of the divalent or trivalent metal salt aqueous solution will also be high, and therefore the concentration varies depending on the purpose and is not uniquely determined.

In each of the compositions according to the above composition examples, natural latex rubber was used as the latex rubber, a nonionic surfactant was used as the surfactant, and calcium nitrate was used as the divalent metal salt. What we did to determine the wall thickness was to immerse the core metal in a natural latex rubber solution for 1 minute, then immerse it in this coagulant, then immerse it in natural latex rubber for 4 minutes, and then air dry it. It is. As is clear from the difference in wall thickness, the more divalent or trivalent metal salt there is, the thicker the wall becomes.
Also, the larger the amount of latex rubber, the thicker the wall.

(5) Delamination prevention agent applied between each rubber layer In the balloon catheter of the present invention composed of multiple rubber layers, this agent is selectively used between layers where there is a risk of delamination between the layers. Its characteristics are described below.

It is preferable to use a latex coagulant prepared by mixing latex rubber, a surfactant, and a divalent metal salt in water in an emulsion state. The latex rubber is liquid, and various latex rubbers such as natural latex rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, recycled rubber, and isoprene rubber can be used. Further, to this latex rubber, powdered sulfur, colloidal sulfur, etc. are added as a vulcanizing agent, diethyldithiocarbamate, etc. are added as a vulcanization accelerator, and milk casein, etc. are added as a thickening agent.

Surfactants include anionic surfactants such as fatty acid salts, higher alcohol sulfate ester salts, liquid fatty oil sulfate ester salts, aliphatic amino and aliphatic amide sulfates, nonionic ether sulfate ester salts, liquid fatty oil sulfate esters. There are salts, sulfates of aliphatic amines and aliphatic amides, nonionic ether sulfate ester salts, alkylaryl sulfonates, etc.
Cationic activators include aliphatic amine salts,
There are quaternary ammonium salts, alkylpyridinium salts, etc., and examples of amphoteric activators include imidazoline derivatives, higher alkylaminos, sulfate esters, etc. Specifically, there are long-chain aliphatic betaines. Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenol ethers, polyoxyethylene alkyl esters, sorbitan alkyl esters, and polyoxyethylene sorbitan alkyl esters.

Further, as the divalent or trivalent metal salt, suitable chlorides include barium chloride, calcium chloride, and nitrates include barium nitrate, calcium nitrate, and aluminum sulfate. In addition,
The composition, manufacturing method, etc. of this coagulant are as described in section (4) above.

(6) Volatile silicone solution to be applied to the tip of the thin rod-shaped mold. This is used to form an opening that communicates the fluid passage (lumen) formed by the thin rod-shaped mold with the balloon section. This is to prevent adhesion, and the following can be used. Various silicone oils, dimethylpolysiloxanes, methylhydrogensiloxanes, methylphenylsiloxanes can be used.

(7) Gap-forming substance This is used to form the balloon part, and the following compositions can be used.

Hydrophilic three-dimensional structures can be used, such as natural hydrophilic polymers such as starch, carboxymethyl cellulose, and proteins, or three-dimensional hydrophilic polymers obtained by polymerization reactions, or cross-linked linear polymers. It is a three-dimensional hydrophilic polymer obtained by Monomers used in the synthesis of three-dimensional hydrophilic polymers include hydroxy low alkyl acrylate/methacrylate, hydroxy low alkoxy low alkyl acrylate/methacrylate,
For example, 2-hydroxyethyl acrylate,
Examples include 2-hydroxyethyl methacrylate, diethylene glycol monomethacrylate, diethylene glycol monoacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, and dipropylene glycol monomethacrylate. Examples of crosslinking agents for three-dimensionalizing hydrophilic chain polymers include ethylene glycol diacrylate, ethylene glycol dimethacrylate, propylene glycol diacrylate, diethylene glycol dimethacrylate, dipropylene glycol dimethacrylate, diethylene glycol diacrylate, and diethylene glycol diacrylate. Propylene glycol diacrylate, divinylbenzene, divinyltoluene, diallyl tartrate, allyl pilpart, allyl maleate, divinyl tartrate, triallylmelamine, N,N'-methylenebisacrylamide, glycerin trimethacrylate, diallyl maleate, divinylethyl, dialkyl Monoethylene glycol citrate, ethylene glycol vinyl allyl citrate, allyl vinyl maleate, diallyl itaconate, ethylene glycol diester of itaconic acid, divinyl sulfone, hexahydro-1,3,5-triacryl triazine, triallyl phosphoric acid, benzene phosphoric acid diallyl ester of, polyester with maleic anhydride and triethylene glycol,
polyallyl glucose (e.g. triallyl glucose), polyallyl sucrose (e.g.
Examples include pentaallyl sacrose) sacrose diacrylate, glucose dimethacrylate, pentyrythritol tetraacrylate, sorbitol dimethacrylate, diallyl aconitate, divinyl citraconate, diallyl fumarate, and the like. Quantitatively speaking, 0.1
~2.5% (preferably 2.0%), but 15
~20% may also be used. Furthermore, as a reaction initiator, there are t-butyl paraoctate, benzyl paraoxide, isopropyl paracarbonate, methyl ethyl ketone para oxide, cuumene hydropara oxide, dicumyl para oxide, etc., and 0.05 to 10 % (preferably 0.1-0.2%)
is appropriate.

The polymerization reaction can also be initiated by radiation such as ultraviolet rays or gamma rays.

The above-mentioned monomers, initiators, crosslinking agents, etc. are charged in appropriate amounts within the above-mentioned ranges, and radical polymerization is carried out for 20 to 30 minutes.
Obtained by carrying out at 150°C (usually 40-90°C).

These three-dimensional structural materials are not particularly limited as long as they have hydrophilic properties and can impregnate an appropriate amount of water and a latex rubber coagulant.

Further, as the gap-forming substance, a volatile solution of silicone and a lower alcohol solution of a divalent or trivalent metal salt are used, and these are used as a mixed solution or individually sequentially. Known volatile solvents for silicone, such as tetrahydrofuran and acetone, can be used at a ratio of 100 parts by volume per 7 to 20 parts by volume of silicone. The divalent or trivalent metal salt acts as a coagulant for latex rubber. As the lower alcohol, those having 4 or less carbon atoms are preferred from the viewpoint of compatibility with the polyvalent metal salt. Usually, the polyvalent metal salt is used as a 5-10% solution using the lower alcohol as a solvent. Further, the volume ratio of the alcoholic solution of the polyvalent metal salt to the volatile solution of silicone is preferably 3:1 to 4:1.

Specific effects of the invention (1) In the present invention, since the balloon catheter is integrally formed by sequentially laminating rubber layers, the balloon catheter is not attached as separate parts as in the past. Low reliability between parts is never a problem, and the product defect rate is low.
It is highly reliable in use.

(2) In the present invention, a coagulant with good build-up properties is used for rod-shaped molds, and a volatile silicone solution that requires build-up properties and mold release properties is used for bar-shaped molds.
Mixed coagulant of lower alcohol solution of valent or trivalent metal salt, coagulation of emulsion of latex rubber and divalent or trivalent metal salt aqueous solution that requires build-up properties and non-hygroscopic properties for molds for forming branch parts. Manufacture is simple and there is no risk of delamination by carefully using different agents and, if necessary, using delamination preventive agents for the emulsion of latex rubber, surfactant, and divalent or trivalent metal salt aqueous solution between the rubber layers. A balloon catheter without

(3) Since the balloon part is formed by not adhering a part between the rubber layers, the balloon part does not protrude more than other parts, making it very convenient to use.

(4) If a volatile solution of silicone and a lower alcohol solution of a divalent or trivalent metal salt are used as a latex rubber coagulant for tapered molds, both build-up properties and mold release properties can be satisfied.

(5) As a latex rubber coagulant for forming branch parts, if a latex rubber coagulant prepared by mixing a latex rubber surfactant and a divalent or trivalent metal salt in an emulsion state with water is used, it will improve build-up properties and non-moisture absorption. Both sexes can be satisfied.

(6) If a mixed solution of a volatile solution of silicone and a lower alcohol solution of a divalent or trivalent metal salt is used as the gap-forming substance, a gap, that is, a balloon portion, can be reliably formed.

[Brief explanation of drawings]

1, 2, 3, and 4 are partial longitudinal sectional views showing the method for manufacturing a balloon catheter of the present invention in the order of steps, with a first rubber layer, a second rubber layer, and a third rubber layer, respectively. It shows the state in which the rubber layer and the fourth rubber layer have been formed. FIG. 5 is a schematic perspective view showing a thin rod-shaped mold and a branch forming mold. Explanation of symbols, 1... Rod-shaped mold, 2... First rubber layer, 3... Thin rod-shaped die, 4... Thin bar-shaped die tip, 5... Branch part forming die, 6... Auxiliary rubber layer, 7... Gap forming substance, 8... Second rubber layer, 9
...Balloon inflation section, 10...Third rubber layer.

Claims (1)

[Claims] 1. In manufacturing a balloon catheter, (a) a latex rubber coagulant made of an alcoholic solution of a divalent or trivalent metal salt is coated on a rod-shaped mold for forming a passageway of the catheter; rear,
(b) Mixing water, latex rubber, surfactant, and divalent or trivalent metal salt into the first latex rubber layer in the form of an emulsion. (c) A latex rubber coagulant for thin rod molds is coated on a thin rod mold to form a passage communicating with the balloon part, and a branch conductor is applied to the narrow rod mold to form a passage communicating with the balloon part. After applying a latex rubber coagulant for forming a branch part to a mold for forming a branch part to form a passage, insert the thin rod-shaped mold along the rod-shaped mold, and insert the tip of the mold into the tip of the rod-shaped mold. (d) the tip of the thin rod-shaped mold and its vicinity; After depositing a gap-forming material to form a balloon on the circumference of the metal rod, the whole is immersed in a latex rubber solution again and dried to form a second latex rubber layer; A method for manufacturing a balloon catheter, comprising removing a mold, a branch forming mold, and a thin rod-shaped mold. 2. The method for manufacturing a balloon catheter according to claim 1, wherein the latex rubber coagulant for the thin rod-shaped mold is a volatile solution of silicone and a lower alcohol solution of a divalent or trivalent metal salt. 3. The latex rubber coagulant for forming the branched portion is a latex rubber coagulant prepared by mixing latex rubber, a surfactant, and a divalent or trivalent metal salt in water in the form of an emulsion.
A method for manufacturing a balloon catheter according to item 1 or 2. 4. The balloon catheter according to any one of claims 1 to 3, wherein the gap-forming substance is a mixed solution of a volatile solution of silicone and a lower alcohol solution of a divalent or trivalent metal salt. manufacturing method.