JPH024307B2 - - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing catheters, and in particular to a method for manufacturing catheters made of latex rubber. Prior art and its problems As a method for manufacturing a catheter made of latex rubber, a rod-shaped mold that forms a catheter passageway is coated with a coagulant for latex rubber, is immersed in a latex rubber liquid, and dried to form a first latex rubber layer. A common method is to form a latex rubber layer, apply a coagulating liquid for latex rubber, form a second latex rubber layer by dipping in the latex rubber liquid and drying, and repeat until the latex rubber has the required thickness. It was hot. and,
The latex rubber coagulant used between each layer was generally the same as that originally applied to the rod-shaped mold. However, since these coagulants have hygroscopic properties, they are easily affected by moisture in the molding atmosphere after adhesion of the coagulant, and tend to cause tubing defects during the manufacture of catheters. Furthermore, the strength to bind the latex rubber layers of the manufactured catheter was poor, and there was a risk that the layers would separate during insertion or indwelling in the urethra or the like. Furthermore, although it has coagulation ability, it is not sufficient in terms of build-up properties of latex rubber, and it requires a lot of soaking time to obtain the required thickness of latex rubber, resulting in poor production efficiency. . OBJECTS OF THE INVENTION Therefore, an object of the present invention is to provide a latex rubber catheter that can efficiently produce a latex rubber catheter that does not cause tubing defects due to the influence of moisture in the molding atmosphere and does not have the risk of peeling between layers. The purpose is to provide a manufacturing method. To achieve the object of the present invention, in manufacturing a catheter made of latex rubber, (a) a latex rubber made of a lower alcohol solution of a divalent or trivalent metal salt is coagulated in a rod-shaped mold for forming a passageway of the catheter; apply the agent,
(b) immersing the coagulant-coated rod-shaped mold in a latex rubber solution and drying it to form a first latex rubber layer; and (c) forming a rod-shaped mold with the first latex rubber layer formed thereon. Into the mold, add latex rubber and surfactant to water.
A delamination prevention agent mixed with a valent or trivalent metal salt in an emulsion state is applied, dried,
Next (d) the rod-shaped mold coated with the delamination prevention agent,
A method of manufacturing a latex rubber balloon catheter includes immersing the catheter in a latex rubber solution and drying it to form a second latex rubber layer, and (e) removing the rod-shaped mold. Furthermore, the second latex rubber layer
The latex rubber layer is preferably more flexible than the latex rubber layer. DETAILED DESCRIPTION OF THE INVENTION Hereinafter, a method for manufacturing a latex rubber catheter according to the present invention will be described in detail with reference to the accompanying drawings. First, as shown in FIG. 1, a coagulant 2 made of a lower alcohol solution of a divalent or trivalent metal salt is applied to a rod-shaped mold 1 for forming a drainage or chemical passage. Then, it is dried to volatilize the lower alcohol. The drying temperature is preferably 50 to 60°C and the drying time is preferably about 20 minutes. Then, immerse it in latex rubber solution and keep it at room temperature for 3.5~
By drying for about 7 minutes, a first latex rubber layer 3 is formed on the circumferential surface of the rod-shaped mold 1. Then, on this first latex rubber layer 2, a delamination preventive agent 3 is deposited which does not have hygroscopicity, makes the adhesion of the next latex rubber solution good, and further prevents peeling between the latex rubber layers. The method of attachment is carried out by immersing a rod-shaped mold into the solution of the delamination prevention agent 4, similar to the above-described deposition of the latex rubber solution. Also, other known attachment means may be used. This anti-delamination agent is prepared by mixing latex rubber, a surfactant, and a divalent or trivalent metal salt in water in an emulsion state. Details will be described later. The delamination preventive agent 4 was applied to the surface of the first latex rubber layer and
The rod-shaped mold 1 that has been dried for about a minute is further immersed in a latex rubber solution and dried to form a second latex rubber layer 4. Drying here requires complete drying in order to easily remove the mold, including preliminary drying at a temperature of 30 to 35°C for 20 minutes, and
It is preferable to perform main drying at ~75°C. Furthermore, the rod-shaped mold 3 is removed from these and vulcanized as necessary.
A latex rubber catheter is manufactured through chlorination, etc. In addition, if the required thickness of the latex rubber cannot be obtained by dipping twice, the application of the delamination preventive agent and drying, and the immersion in the latex rubber solution and drying are repeated as many times as necessary. Furthermore, if the latex rubber concentration in the latex rubber coagulating liquid for forming the second latex rubber layer is set to be lower than the latex rubber concentration in the latex rubber coagulating liquid for forming the first latex rubber layer, This is preferable because it allows the formation of a second latex rubber layer that is relatively soft. Further, it is preferable to use the above-mentioned delamination agent as the coagulant that is first applied to the rod-shaped mold 1. This is because the drying time can be shortened and the latex rubber liquid has good adhesion. Various materials used in the manufacturing process as described above will be explained. (a) 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. Furthermore, this latex rubber contains vulcanization accelerators such as powdered sulfur and colloidal sulfur, vulcanization accelerators such as diethyldithiocarbamate, thickeners such as milk casein, and stabilizers such as potassium hydroxide and other surfactants. Added as appropriate. (b) Coagulant that adheres to the rod-shaped mold This is a lower alcohol solution of a divalent or trivalent metal salt, and the purpose of this is to coagulate the latex rubber adhered to the rod-shaped mold 1. This is for forming a layer. As the divalent or trivalent metal salt, calcium nitrate, barium nitrate, calcium chloride, barium chloride, aluminum sulfate, etc. can be used. Further, as the lower alcohol, methanol, ethanol, and a mixed solution of these and water are used. Furthermore, if necessary, so that the coagulant adheres uniformly to the rod-shaped mold,
Wetting agents are added as appropriate. As the wetting agent, alkyl, allyl, sulfonate, etc. can be used. Furthermore, the weight ratio of the divalent or trivalent metal salt and the lower alcohol to be mixed varies depending on the thickness of the latex rubber to be obtained by immersing it in the latex rubber liquid. If required, the weight proportion of the metal salt will be increased. (c) Interlayer peeling prevention agent As mentioned above, this is a mixture of latex rubber, a surfactant, and a divalent or trivalent metal salt in water in an emulsion state, and has the function of adhering each layer of latex rubber. It is something that you have. The latex rubber and divalent or trivalent metal salt used here are those mentioned above. Examples of surfactants include anionic surfactants which are substances that lower the interfacial energy or surface tension of latex rubber, such as fatty acid salts, higher alcohol sulfate ester salts, liquid fatty oil sulfate ester salts,
sulfates of aliphatic amines and amides;
There are nonionic ether sulfate ester salts, allylyl sulfonates, etc., cationic activators include aliphatic amine salts, quaternary ammonium salts, alkylpyridinium salts, etc., and amphoteric activators include imidazoline derivatives. Specifically, there are long-chain aliphatic betaines such as , higher alkylamino type, and sulfuric ester type. Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenol esters, polyoxyethylene alkyl esters, rilbitan alkyl esters, and polyoxyethylene sorbitan allyl esters. Next, a method for mixing this anti-delamination agent in an emulsion state will be explained. A latex rubber solution with a required concentration is prepared by mixing latex rubber and water in a first container.
Next, a required amount of an aqueous surfactant solution is added to the latex rubber solution and stirred well. Next, the second
Prepare an aqueous solution of a divalent or trivalent metal salt in a container. Then, while stirring this divalent or trivalent metal salt aqueous solution, a latex rubber solution to which the above-mentioned surfactant solution has been added is gradually added, thereby producing a delamination prevention agent that is mixed in an emulsion state. can. The reason for using such a method is that divalent or trivalent metal salts are originally coagulants for latex rubber;
If mixed into a latex rubber solution, the rubber will coagulate. Therefore, by adding a surfactant to a latex rubber solution to form a surfactant coating on the rubber surface, and gradually adding it to an aqueous divalent or trivalent metal salt solution with stirring, latex rubber can be It is possible to obtain something that can be mixed in an emulsion state without solidifying. Next, the composition ratio of each component of this delamination preventing agent will be explained. First, the amount of surfactant is
Determined by the amount of latex rubber. This is because, 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 range of both is 20:1 to 200:1 as a weight ratio of latex rubber and surfactant.
The preferred range is 25:1 to 150:1.
It is. If the amount of surfactant is so small as to exceed 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 solution of divalent or trivalent metal salts. be. In addition, if the amount of surfactant exceeds 20:1, it will inhibit the tackiness of the latex rubber solution that is later soaked and adhered.
This is because a molded latex rubber catheter may cause delamination between layers. Further, the concentration of the aqueous solution of latex rubber varies depending on the thickness of the latex rubber to be obtained by dipping and adhering. If you need more wall thickness,
The concentration of the latex rubber solution increases. 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. In other words, if thick wall thickness is required,
The concentration of the divalent or trivalent metal salt aqueous solution also increases. Therefore, the concentration differs depending on the purpose and is not uniquely determined. Below, examples of the composition of each component of this anti-delamination agent and the wall thickness of a catheter manufactured by the method for manufacturing a catheter of the present invention using them are shown. In each of the compositions according to the above composition examples, natural latex rubber was used as the latex rubber, aluminate polyglycol ether, which is a nonionic surfactant, was used as the surfactant, and divalent calcium nitrate was used as the metal salt. Further, the wall thicknesses shown in Table 1 were determined using the following examples in the method of the present invention. First, a latex rubber coagulant consisting of a methanol solution of calcium nitrate is attached to a rod-shaped mold 1, dried at a temperature of 50° to 60°C for 20 minutes, and then immersed in a latex rubber liquid containing appropriate additives to a natural latex rubber liquid. Soak for 4 minutes at room temperature (around 23℃)
After drying for 4 minutes, apply the delamination prevention agent described above and dry for 4 minutes at room temperature (around 23℃), and then apply the same latte as above.

[Table] Temperature 30-35 after 4 minutes immersion in rubber liquid
After preliminary drying at 70-75°C for 20 minutes and main drying at 70-75°C for 20 minutes, the rod-shaped mold was removed. Table 1 shows the wall thickness of the latex rubber catheter obtained as a result. Specific Effects of the Invention The method for manufacturing a latex rubber catheter according to the present invention, namely: (1) When manufacturing a latex rubber catheter, (a) A divalent or trivalent metal is added to a rod-shaped mold for forming a catheter passageway. A latex rubber coagulant made of a lower alcohol solution of salt is applied and dried, and (b) the rod-shaped mold coated with the coagulant is immersed in the latex rubber liquid and dried to form a first latex rubber layer; Next, (c) a delamination prevention agent prepared by mixing latex rubber, a surfactant, and a divalent or trivalent metal salt in water in an emulsion state is applied to the rod-shaped mold in which the first latex rubber layer has been formed. , drying, and then (d) immersing the rod-shaped mold coated with the delamination prevention agent in a latex rubber solution and drying it to form a second latex rubber layer; (e) removing the rod-shaped mold. According to the method for manufacturing a latex rubber balloon catheter, it is possible to manufacture a latex rubber catheter that improves the adhesion between each layer and does not peel between the latex rubber layers. Since the material does not have a molding atmosphere, it is possible to easily manufacture a catheter made of latex rubber without being affected by the molding atmosphere, that is, without causing tubing defects during manufacturing. Further, the latex rubber for forming the second latex rubber layer has good build-up properties, and the dipping time can be shortened, allowing efficient production of catheters. (2) Also, if the second latex rubber layer is more flexible than the first latex rubber layer, a certain degree of hardness can be obtained by the first latex rubber layer, and since the second latex rubber layer is flexible, , it is possible to easily manufacture a catheter that can prevent damage to tissues such as the urethral wall during insertion and indwelling.

[Brief explanation of drawings]

1, 2, 3, and 4 are cross-sectional views showing the method for manufacturing a latex rubber catheter according to the present invention in the order of steps. Explanation of symbols 1...rod-shaped mold, 2...coagulant, 3...
1st latex rubber layer, 4... delamination prevention agent,
5...Second latex rubber layer.

Claims (1)

[Scope of Claims] 1. In manufacturing a catheter made of latex rubber, (a) a rod-shaped mold for forming a passageway of the catheter is coated with a latex rubber coagulant made of a lower alcohol solution of a divalent or trivalent metal salt; Arrived,
(b) immersing the coagulant-coated rod-shaped mold in a latex rubber solution and drying it to form a first latex rubber layer; and (c) forming a rod-shaped mold with the first latex rubber layer formed thereon. Into the mold, add latex rubber and surfactant to water.
A delamination prevention agent mixed with a valent or trivalent metal salt in an emulsion state is applied, dried,
Next (d) the rod-shaped mold coated with the delamination prevention agent,
A method for manufacturing a latex rubber catheter, comprising: immersing it in a latex rubber solution and drying it to form a second latex rubber layer; (e) removing the rod-shaped mold. 2. The method of manufacturing a latex rubber catheter according to claim 1, wherein the second latex rubber layer is more flexible than the first latex rubber layer.