JP3057850B2 - Flexible part of endoscope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible portion constituting an insertion portion to be inserted into a body cavity or the like in an endoscope used for medical or industrial purposes.

[0002]

2. Description of the Related Art In general, an endoscope generally includes a main body operation section, an insertion section inserted into a body cavity or the like, and a flexible cord connected to a light source or the like. The insertion part is composed of a flexible part that bends freely along the insertion path, such as in the body cavity, from the part connected to the main body operation part. An angle part is provided at the tip of this flexible part, and a tip of the angle part is provided. Is provided with a hard tip portion. Here, the requirement that the flexible portion that forms the majority of the insertion portion must have is that the flexible portion first bends freely along the insertion path, and that the light guide, forceps, and other treatment tools are inserted. Because the treatment instrument insertion channel and other members are installed inside, it has excellent shape retention and prevents buckling, crushing, deformation, etc., even when pressed or bent by external force. There must be. In addition, since it is inserted into a body cavity or the like, it has good slipperiness, is easy to clean, and is not deteriorated or deteriorated by a chemical solution, unless it has excellent so-called chemical resistance. No. In addition to these, extremely severe conditions are imposed, such as being hardly damaged and requiring durability.

[0003] In order to meet the above various requirements,
The flexible part is configured as follows. First, a helical tube formed by spirally winding a metal strip is used as the innermost layer, and a net formed by braiding metal fibers is covered on the helical tube. Further, a skin layer made of urethane resin or the like is laminated on the net. I am trying to do it. Here, the spiral tube is formed in two layers wound in opposite directions to have shape retention and crush resistance, and prevents the outer diameter from changing even if twist is applied. In addition, the net stabilizes the spiral tube and attempts to satisfy such a demand by integrating the outer skin layer with the net.

[0004] On the other hand, the outer skin layer is constituted as a resin molded layer in which a large part of the thickness is formed by laminating a soft synthetic resin such as urethane resin having flexibility on a net by molding means. Since a soft resin itself has viscosity, a thin top coat layer is formed as a surface layer. The topcoat layer slip goodness, to meet the requirements of chemical resistance, formed by the hardened been urethane <br/> tan resin with a crosslinking type. Here, in order to form the top coat layer, urethane resin is applied to a three-layer structure including a spiral tube, a net, and a resin molding layer by dipping or the like, and the urethane resin is left for a certain period of time, and then heated. So that it is crosslinked.

[0005]

By the way, the above-mentioned top coat layer is hardened by cross-linking, whereas the resin molding layer constituting the lower layer is soft, so When bent, the layers are easily separated from each other and wrinkles are formed, which is not only unfavorable in appearance, but also increases resistance when inserted into a body cavity or the like, particularly when passing through a stenotic part, and There are problems such as causing pain and discomfort.

In order to prevent the above-mentioned separation between the top coat layer and the resin molding layer, an intermediate layer having an intermediate hardness between the top coat layer and the resin molding layer is interposed therebetween. Attempts have been made to reduce the difference in hardness between layers. However, the material of the intermediate layer must be compatible with both the top coat layer and the resin molding layer, and its hardness must be intermediate between the two layers. At present, it is not possible to obtain a material having a different quality. Also, the endoscope
The hardness required for the insertion part varies depending on the application.For example, a gastroscope or a bronchoscope, etc., must have a certain degree of hardness. Need to be soft. Therefore, if an intermediate layer having a hardness between the top coat layer and the resin molding layer is interposed as a conventional countermeasure against peeling, the entire flexible part becomes harder, and the flexible part such as a colonoscope or a duodenum is used. As inappropriate.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems and problems of the prior art described above, and an object of the present invention is to provide a flexible endoscope without hardening the flexible portion. It is to ensure that the top coat layer can be prevented from peeling off.

[0008]

Means for Solving the Problems In order to achieve the above-mentioned object, the soft portion of the present invention comprises a resin molded layer in which the outer layer is laminated on a net by a molding means, and a surface layer portion. Hardened by heating and crosslinking.
And the top coat layer consisting of structure formation to a synthetic resin, is interposed between the top coat layer and the resin molded layer, the top
The outer surface side of the coating layer keeps the cured state, and the inner surface side is soft
And an intermediate layer formed of a resin containing a plasticizer for making the layer into a plasticizer.

[0009]

According to the present invention, an intermediate layer is interposed between the soft resin molding layer and the hard top coat layer. The intermediate layer has a hardness between the resin molding layer and the top coat layer. Is not a requirement, but a resin containing a plasticizer. As the resin used as a carrier of the plasticizer in the intermediate layer, in consideration of the familiarity with the materials of the resin molding layer and the top coat layer, when these are formed of urethane resin, the urethane resin is also used in the intermediate layer. It is preferable to use As the plasticizer, dibutyl phthalate (DBP), which is generally used,
Phthalates such as di-2-ethylhexyl phthalate (DOP), dioctyl adipate (DOA),
Linear dibasic acid esters such as dioctyl azelate (DOZ), phosphates, epoxidized vegetable oils and the like are used. However, the plasticizer must have good compatibility with the resin and high migration properties.

Here, the requirement for the migration property is to transfer the plasticizer to the top coat layer, which is a hard member, and to plasticize the inner surface side. by this,
The outer surface of the top coat layer is formed as a hard surface so as to maintain the slipperiness and chemical resistance, and the inner surface side is softened so that peeling between layers can be prevented.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, FIG. 1 shows the entire configuration of an endoscope. In the figure, 1 is a main body operation unit, 2 is an insertion unit, and 3 is a connection cord. The insertion portion 2 is a flexible portion 2a that bends from the side connected to the main body operation portion 1 to follow the insertion path.
An angle portion 2b is provided at the tip of the flexible portion 2a, and a hard tip portion 2c is provided at the tip of the angle portion 2b. As is well known, an illumination window and an observation window are provided in the distal end hard portion 2c, and a treatment tool outlet for inserting a forceps and other treatment tools is opened, and cleaning of a body cavity, an observation window, and the like is performed. The air supply / water supply port for the operation is open. Here, the observation window faces the solid-state imaging device (the entrance end of the image guide in the case of an optical endoscope), and the emission end of the light guide faces the illumination window. Further, a treatment instrument insertion channel is connected to the treatment instrument outlet, and an air supply / water supply tube is connected to the air supply / water supply port. A cable (or an image guide) connected to the solid-state imaging device, a light guide, a treatment tool insertion channel, an air supply / water supply tube, and the like are transferred from the hard distal end portion 2c to the main body operation portion 1 via the angle portion 2b and the flexible portion 2a. It is extended.

Here, the flexible portion 2a of the insertion portion 2
It is necessary to bend freely along the insertion path in a body cavity or the like. In particular, in the case of a colonoscope, a duodenoscope, or the like, the insertion path is complicated and sharply bent, so that softness is required to improve insertability. In addition, the diameter must be reduced as much as possible in order to reduce the pain of the patient. Further, a relatively fragile member such as a light guide and a treatment tool insertion channel is inserted into the inside of the flexible portion 2a, and the filling rate is considerably high in order to eliminate waste in the internal space. Therefore, it must have good shape retention, and must be prevented from being crushed or deformed even when pressed from the outside or bent extremely. Further, since it is inserted into a body cavity or the like, it must have good sliding properties, must not be deteriorated by a cleaning solution, must have chemical resistance, and must have durability.

Based on the above requirements, the flexible portion 2a is formed of a flexible tube, and its structure is as shown in FIG. First, a double spiral tube 10 constitutes the innermost layer. The spiral tube 10 is formed by spirally winding a metal strip having a certain degree of resilience, such as stainless steel, into a tubular shape. The spiral tube 10 is an inner spiral tube 10.
a and the outer spiral tube 10b are wound in mutually opposite directions. The spiral tube 10 is covered with a net 11 made of braided metal fibers, and is fixed to the spiral tube 10 by applying an adhesive 12 to the net 11. The helical tube 10 and the net 11 allow the flexible portion 2
The structure (a) is formed so as to be flexible and exhibit a shape maintaining function.

An outer skin layer 13 is laminated outside the net 11. The outer skin layer 13 has a three-layer structure. First, the innermost layer is a resin molding layer 14, on which an intermediate layer 15 is laminated. The top coat layer 16 is formed. The resin molding layer 14 is formed by molding a soft resin, for example, a urethane resin, directly on the net 11 by molding means such as extrusion molding, and the resin molding layer 14 is the thickest portion. Further, since the top coat layer 16 constitutes the surface layer portion, in order to satisfy various requirements such as good slippage, chemical resistance, resistance to scratches and durability, urethane crosslinked and cured. It is formed of resin. In these respects, there is no particular difference from the prior art.

However, as the intermediate layer 15 interposed between the resin molding layer 14 and the top coat layer 16, a resin containing a large amount of a plasticizer is used. Here, as a plasticizer, generally used dibutyl phthalate (DBP),
Phthalates such as di-2-ethylhexyl phthalate (DOP), dioctyl adipate (DOA),
Linear dibasic acid esters such as dioctyl azelate (DOZ) and dioctyl sebacate (DOS), phosphates, and epoxidized vegetable oil can be used. The resin as a carrier of the plasticizer is the resin molded layer 1
Urethane resin is preferred from the viewpoint of conformability to 4 and the top coat layer 16. Thus, in order to improve the compatibility between the plasticizer and the resin, the resin may be a mixture of the urethane resin and, for example, vinyl chloride or another resin having excellent compatibility with the plasticizer. . A condition that must be provided as a plasticizer is that it has migration properties. For this purpose, DOP, DOA, DO
Z, DOS, etc. are particularly preferred.

When the intermediate layer 15 containing a plasticizer having a migration property is provided inside the top coat layer 16, the plasticizer migrates to the top coat layer 16 and the inner surface thereof is softened. I do. However, since the surface layer is hardened by crosslinking, the surface layer maintains a hard state. Therefore, soft <br/> of toward the inner surface top coating layer 16 itself from the surface layer side, that the topcoat layer 16 itself is in the thickness direction
Since the hardness changes , it is not necessary for the intermediate layer 15 to have an intermediate hardness between the top coat layer 16 and the resin molding layer 14, and the entire flexible portion 2a does not become too hard. From the resin molding layer 14 to the top coat layer 1
The hardness is made uniform up to 6.

Here, in order to form the outer layer 13, a resin molding layer 14 is first laminated on the net 11 by extrusion or the like, and then the intermediate layer 15 is formed by dipping or the like.
Is laminated thereon. Thereafter, similarly to the intermediate layer 15, the urethane resin constituting the top coat layer 16 is laminated on the intermediate layer 15 by dipping means, left for a predetermined time, and then heated, so that the top coat layer 16 is heated. The constituent urethane resin is crosslinked. However, the plasticizer moves from the intermediate layer 15 to the urethane resin side of the top coat layer 16 during this standing time, and softens the urethane resin. However, it is necessary to control the amount of the plasticizer to be added and the standing time so that the plasticizer does not migrate to the surface layer. Thereby, when crosslinked, the surface layer portion of the top coat layer 16 is hardened, but the inner surface side is kept in a softened state by the plasticizer. Note that the plasticizer of the intermediate layer 15 is
However, since the resin molding layer 14 has an extremely large thickness with respect to the intermediate layer 15, the resin molding layer 14 does not come into contact with the adhesive 12 applied to the net 11.
Therefore, the adhesive force of the adhesive 12 is not reduced.

With the above-described structure, the top coat layer 16 is in a state where the outer surface is hard and the inner surface side is softened, and the function as the top coat layer 16 is not lost, and the top coat layer 16 rapidly extends over the entire outer coat layer 13. Thus, there is no possibility that any difference in hardness will be produced, and therefore, there is no possibility that separation occurs between the layers constituting the outer skin layer 13, particularly between the top coat layer 16 and the intermediate layer 15.

Specific Example A net 11 is covered on a spiral tube 10 and this net 11
A polyurethane liquid as an adhesive, and then apply a resin molding layer 14 made of polyurethane to a thickness of 0.3 to 0.3.
The layers were laminated so as to be 0.4 mm. Then, DOP was used as a plasticizer, and the plasticizer was immersed in a dipping liquid in which thermoplastic urethane was mixed at a mixing ratio of 10: 1 to form an intermediate layer 15 having a thickness of 0.1 mm. After the intermediate layer 15 was dried, it was immersed in a thermoplastic polyurethane liquid to laminate a resin layer forming a top coat layer having a thickness of 0.1 mm. After standing for 0.5 hour in this state, the resin layer was cross-linked by heating at 100 ° C. for 1 hour to form the top coat layer 16. When the flexible part thus obtained was subjected to a repeated bending test, there was no delamination between layers even after 3,000 repeated bendings.

[0020]

As described above, according to the present invention, the intermediate layer formed of the resin containing the plasticizer is interposed between the resin molding layer and the top coat layer forming the surface layer. The top coat layer can be softened on the inner surface side while giving the surface layer the necessary degree of hardness, so that the entire outer skin layer extends from the surface layer to the innermost layer. Abrupt change in hardness does not occur, delamination between layers can be reliably prevented, and it is not necessary to use an intermediate layer having the hardness next to the top coat layer, so that the overall softness It is also possible to form a flexible portion such as a colonoscope or a duodenoscope, which can provide necessary conditions.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an endoscope.

FIG. 2 is a half sectional view of a soft part showing one embodiment of the present invention.

[Explanation of symbols]

 2 Insertion part 2a Flexible part 2b Angle part 2c Tip hard part 10 Spiral tube 11 Net 12 Adhesive 13 Skin layer 14 Resin molding layer 15 Intermediate layer 16 Top coat layer

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) A61B 1/00-1/32

Claims (1)

(57) [Claims] A helical tube formed by spirally winding a metal strip is covered with a net, fixed with an adhesive, and an outer skin layer is laminated on the outside of the net in a flexible portion of an endoscope. , the outer skin layer, and a resin molded layer laminated by forming means, the surface layer portion is formed on the net and heated is crosslinking
A top coat layer made of a synthetic resin that is hardened by being applied, and is interposed between the top coat layer and the resin molding layer, and the outer surface of the top coat layer maintains a cured state.
And a middle layer formed of a resin containing a plasticizer for softening the inner surface side .