JPH1016053A - Medical equipment and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the deformation of parts to conduct a treatment combined with a sterilization process, and to simplify a process by fusion-bonding two or more parts made from a thermoplastic resin in a closed system of high temperature and high pressure. SOLUTION: Two or more parts made from a thermoplastic resin are fusion- bonded in a closed system of high temperature and high pressure. The temperature is 105 deg.C or above, and the pressure is 1.03×10<5> Pa or higher. For example, a cylindrical opening part 21 and a cap 23 are provided as heat resistant parts in a liquid carrying bag, and a ring part 22 is provided as a non-heat resistant part. Next, a bag sheet 11 is fusion-bonded by a conventional method to make a partially fabricated product, after packing a physiological salt solution, the ring part 22 is inserted into the cylindrical opening part 21, and a rubber cock 24 and cap 23 are set. The product is sterilized by a high pressure steam sterilizer. Since the pressure in a container is uniform in all directions, there is no fear of the deformation of a part in one direction and others. When the fusion bonding is desired to be done with greater force, internal pressure is increased with the increase in temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for bonding components of a medical device such as a medical container and a medical device, and a medical device manufactured by the bonding method. More specifically, the present invention relates to a bonding method utilizing heat during high-pressure steam treatment such as high-pressure steam sterilization, and a medical device manufactured by the bonding method.

[0002]

2. Description of the Related Art Although the use of polymer materials in the medical field has been remarkable in recent years, syringes, infusion sets, and the like have been supplied to the market as disposable products because plastic materials can be manufactured in large quantities at low cost. It is well known that it is possible to do so. Although they are inexpensive, they contribute significantly to modern medical care due to the certainty of sterilization and the reduction of labor costs required for boiling disinfection. In addition, plastic containers, mainly for infusions, are becoming plastic, providing a closed system that is light, unbreakable and does not require a ventilation needle. Each of them is assembled into several parts, and is sterilized before being shipped from a dedicated factory to the market. Various methods have been used for assembling and bonding. For example, heat fusion, adhesives, fitting, caulking, solvent bonding and the like can be mentioned. Bonding of the same material such as blood bags and infusion sets made of soft polyvinyl chloride resin can be performed by heat sealing methods such as high-frequency sealing, heat sealing, and impulse sealing, or by using solvents such as methylene chloride and tetrahydrofuran. It is known that a bonding method or the like is possible.

Further, as disclosed in Japanese Patent Publication No. 4-82106 as a method of manufacturing a synthetic resin device, a method of heat-sealing dissimilar materials having poor heat-sealing properties is described as "... An adhesive layer having a heat-fusing property is covered by integral molding, and the heat-sealing is performed. "An ultrasonic method is exemplified as the heat-sealing method. As an example, an ethylene-vinyl acetate copolymer was added to the cylindrical mouth for heat-sealing the body sheet of an infusion bag made of an electron beam cross-linked ethylene-vinyl acetate copolymer and a cylindrical mouth made of polyethylene or polypropylene. It is shown that a combined product obtained by simultaneous molding such as two-color molding is used and attached by heat sealing. Further, Japanese Patent Publication No. 28147/1993 discloses a method of using a holding member made of a thermoplastic resin having a heat shrinking property and preventing a leak between non-fused parts by using the shrinking force. None of the publications describes the method of heating under high-pressure steam, which applies heat evenly from the whole product, but uses the heat, but there is no idea that it is performed simultaneously with the sterilization process such as high-pressure steam sterilization. Processes and the like were required separately, and it was necessary to pay attention to deformation of parts during welding. Also, in the method of joining parts of medical equipment,
It is known that polycarbonate and soft polyvinyl chloride are combined into an appropriate shape and then joined by autoclaving, but the use is limited. Careful observation of the material interface shows that it is not heat fusion but so-called blocking. Furthermore, it is easy to think of using an adhesive for joining dissimilar materials regardless of whether it is a solvent-based or solvent-free system.

[0004] As described above, the joining of dissimilar materials in the prior art uses a heat fusion method using a heat fusion process, a caulking method using a heat shrinkable material, a method using blocking, and an adhesive. However, there is a demand for a better bonding method.

[0005]

The above-mentioned prior arts have the following problems. This is because, in the heat fusion method using the heat fusion step, the bonding step and the sterilization step are separate, so that the process management becomes complicated, and a force in the uniform direction is always applied to the part during the heat fusion. There must be sufficient attention to deformation of parts, etc. Unlike methods such as fitting, blocking, and caulking, which are physically bonded unlike heat fusion, the bonding strength is not so strong, and there is a possibility that leakage or poor bonding may occur in places where strong force is applied or strong vibration is applied. That are not suitable for use. In solvent bonding, residual solvents may affect safety. In the method using an adhesive, the process becomes complicated. Then, in order to solve the above-mentioned problems, an object is to provide a method and a medical device for performing reliable heat fusion while simplifying the process.

[0006]

The above object is achieved by the following means. (1) A medical device in which two or more components made of a thermoplastic resin are fused in a high-temperature, high-pressure closed system. (2) The high temperature is 105 ° C. or higher or the high pressure is 1.
The medical device according to the above (1), which has a pressure of 03 × 10 ⁵ Pa or more. (3) The medical device according to the above (1) or (2), wherein the high-temperature and high-pressure closed system is based on closed-system high-pressure steam. (4) The above-mentioned (1) to (1) to wherein the high-temperature and high-pressure closed system is sterilized.
The medical device according to any one of (3). (5) The medical device according to the above (4), wherein the high-temperature high-pressure closed system is a high-pressure steam sterilization.

(6) The difference in heat deformation temperature between the two or more parts and the material disposed at least in part between them is 2
The medical device according to any one of the above (1) to (5), which has a temperature of 0 ° C. or higher and has a heat-fusing property between the materials. (7) The two or more parts are made of a heat-resistant material that substantially withstands high temperature and high pressure, and at least a part between the two or more parts is thermally fused to both materials under substantially high temperature and high pressure. The medical device according to the above (6), wherein the non-heat-resistant material having adhesiveness is arranged. (8) The heat-resistant material is polyethylene, polypropylene, polybutene, cyclic polyolefin, polymethylpentene-1, acrylic resin, polyethylene terephthalate, polybutylene terephthalate, nylon, polyurethane, polycarbonate, fluororesin, and styrene as one component. (7) The medical device according to the above (7), which comprises at least one selected from the group consisting of copolymers described above. (9) The medical device according to (8), wherein the heat-resistant material includes at least one selected from the group consisting of high-density polyethylene, linear low-density polyethylene, polypropylene, and styrene-based elastomer. (10) The medical device according to (9), wherein the heat-resistant material includes high-density polyethylene. (11) The medical device according to (9), wherein the heat-resistant material includes polypropylene. (12) The medical device according to (9), wherein the heat-resistant material contains polypropylene and a styrene-based elastomer. (13) The medical device according to the above (9), wherein the heat-resistant material contains a styrene-based elastomer and an oil.

(14) The non-heat-resistant material is polyethylene, polypropylene, polybutadiene and ethylene,
The medical device according to any one of the above (7) to (13), comprising at least one selected from the group consisting of a copolymer containing propylene and butadiene as one component and a hydrogenated product thereof. (15) The non-heat-resistant material is polyethylene, ethylene-
α-olefin copolymer, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-vinyl acetate copolymer, ethylene-maleic anhydride copolymer, ethylene-acrylic acid copolymer (7) containing at least one selected from the group consisting of a copolymer, an ethylene-ethylacrylic acid copolymer, an amorphous polypropylene, a propylene-α-olefin copolymer, a propylene-maleic anhydride copolymer, and polybutadiene. ~
The medical device according to any one of (14). (16) The medical device according to any one of the above (1) to (15), wherein the medical device is a medicine container, a liquid nutrient container, or a blood bag. (17) The liquid medicine container is an infusion container, a dialysate container, a blood container for intravascular injection, a liquid container for intramuscular injection, a liquid container for intrameningeal injection, a liquid container for epidural injection, subcutaneous The medical device according to the above (16), which is a container for a drug solution for injection. (18) The medical device according to any one of (1) to (17), wherein the medical device is a disposable product. (19) A method for manufacturing a medical device, wherein two or more components made of a thermoplastic resin are fused in a closed system of high temperature and high pressure.

The high-temperature and high-pressure closed system of the present invention is a system for applying a pressure not uniformly to the temperature required for fusion and its fusion surface, but to apply a uniform pressure from the periphery to finish the fusion aesthetically. is there. The temperature and pressure are appropriate for the production of medical devices, and vary depending on the resin used. Generally, a temperature of 105 ° C. or higher or a pressure of 1.03 × 10 ⁶ Pa or higher is preferable. The temperature is more preferably at least 110 ° C. The temperature may be set in consideration of sterilization conditions necessary for a medical device for sterilization. Note that 105
If the temperature is lower than or equal to 1.0 ° C. or below 1.03 × 10 ⁶ Pa, the temperature or pressure required for fusion is insufficient, and it is difficult to obtain a target medical device. Although the configuration of the gas in the high-temperature and high-pressure closed system of the present invention is not particularly limited, in reality, conditions under high temperature and high pressure with water, that is, steam are preferable. Further, the atmosphere in a high-pressure steam sterilizer or a spray sterilizer also serving as a sterilization step is preferable, but is not limited thereto. This high-pressure steam sterilizer, which is generally called an autoclave, is a pressure-resistant container, into which water or steam is introduced, and which is kept at a pressure of 1.01 × 10 ⁶ Pa (1 atm) or more.
It can be heated to above 00 ° C. It does not refer to steam such as high-pressure water in an open system. Since the pressure in the container is constant in any direction and in any direction (excluding gravity), a force (pressure) is uniformly applied to a portion to be fused, and there is little concern about deformation of the component in one direction. When it is desired to perform fusion with a larger force, increasing the temperature increases the internal pressure and the fusion force according to Boyle-Charles law. This is compared to the method of compressing the mold when performing normal heat sealing or impulse sealing,
The effect is beautifully finished because no local force is applied.

It is preferable that the difference between the thermal deformation temperatures of the parts of the present invention or the materials arranged between the parts is 20 ° C. or more. This is because heat fusion in a closed system high-pressure steam atmosphere represented by a high-pressure steam sterilizer is more beautifully finished,
If the difference is less than 20 ° C., thermal fusion is insufficient, or heat deformation occurs even in heat-resistant parts. Its heat distortion temperature is the Vicat softening point of Japanese Industrial Standards
It is measured by the method of JIS K-7206. The intent of the present invention is that the difference in heat distortion temperature is sufficiently large that the absolute value of the Vicat softening point described below is not important. Since the absolute value changes depending on the closed system high pressure and high temperature conditions, the difference which is a relative value is important. The term “thermal fusion” as used in the present invention refers to, for example, one in which two materials are melted and the interface is not completely understood, one in which a peeling test is performed to cause material destruction,
It refers to a material that has been subjected to a peeling test and a small amount of debris remains on the other party. Therefore, it is not preferable that the material completely peels off at the interface between the two materials. The peeling test is not limited to a particular method, but for example, a method based on a T-type peeling test of Japanese Industrial Standard JIS K6854 can be exemplified. The heat resistance of the present invention means that there is no deformation or change in safety of parts that affect the use and appearance of the medical device under the conditions of high temperature and high pressure when the medical device is bonded. The term "non-heat-resistant" means that the medical device exhibits heat-fusibility to the heat-resistant material under high-temperature and high-pressure conditions when the medical device is bonded.

The heat-resistant material of the present invention does not need to be particularly limited as long as it conforms to the above definition. Considering ordinary medical instruments, generally, the Vicat softening point is preferably 80 ° C. or higher. More preferably, the temperature is 90 ° C. or higher. As the material, polyethylene, polypropylene, polybutene, cyclic polyolefin, polymethylpentene-1,
Examples include those containing at least one selected from the group consisting of acrylic resins, polyethylene terephthalate, polybutylene terephthalate, nylon, polyurethane, polycarbonate, fluororesins, and copolymers of them with styrene as a component. More preferably, it contains at least one selected from the group consisting of high-density polyethylene, linear low-density polyethylene, polypropylene, styrene-based elastomer, polyester elastomer, polyamide elastomer, and polycarbonate. More preferably, those containing high-density polyethylene, those containing polypropylene, those containing polypropylene and styrene-based elastomer, or those containing styrene-based elastomer and oil. Even if these materials are not special ones, commercially available materials are sufficient as long as they are suitable for the use such as safety as a medical device. The non-heat-resistant material of the present invention is not particularly limited as long as it is a material according to the above definition. Considering ordinary medical devices, the melting point is generally 110 ° C. or less, preferably 10 ° C.
Those having a temperature of 0 ° C. or less or a Vicat softening point of less than 100 ° C., preferably less than 90 ° C. are suitable. The material preferably contains at least one selected from the group consisting of polyethylene, polypropylene, polybutadiene, a copolymer containing ethylene, propylene, and butadiene as one component, and a hydrogenated product thereof. More preferably, polyethylene, ethylene-propylene copolymer or ethylene-butene copolymer or ethylene-
Ethylene-α olefin copolymer such as hexene copolymer, ethylene-vinyl acetate copolymer, ethylene-maleic anhydride copolymer, ethylene-acrylic acid copolymer, ethylene-ethylacrylic acid copolymer, amorphous Examples include those containing at least one selected from the group consisting of functional polypropylene, propylene-α-olefin copolymer, propylene-maleic anhydride copolymer, and polybutadiene.
These materials are not particularly special, and commercially available materials are sufficient as long as they are suitable for the use such as safety as a medical device.

One of the two or more parts of the present invention and a material having a low heat distortion temperature between the two or more parts, or one of the parts made of a heat-resistant material and one made of a non-heat-resistant material are used. Although it is preferable from the viewpoint of workability to use a member that has been previously formed by integral molding such as two-color injection molding, insert molding, or two-color coextrusion molding, the present invention is not limited thereto. It is also preferable to integrally mold a plurality of parts of three or more points in the same manner. The present invention is not limited to a specific medical device, but as an example, as a medical container, as a medical container, an infusion container, an anticoagulant solution container, a dialysate container, a drug solution for intravascular injection. Parenteral containers such as a container, a container for a drug solution for intramuscular injection, a container for a drug solution for intrameningal injection, a container for a drug solution for epidural injection, and a container for a drug solution for subcutaneous injection can be exemplified. In addition, a liquid nutrient or the like can be exemplified as an oral agent. In addition, blood bags, IVH
Bag-shaped items such as bags and urine storage bags, infusion sets,
Examples include a blood transfusion set, a blood circuit, and a tube-shaped one such as a catheter. An example will be described below in more detail.

[0013]

【Example】

Embodiment 1 FIG. 1 is an overall view of an infusion bag according to the present embodiment, and FIG. 2 is an enlarged cross-sectional view of the vicinity of a discharge port. The infusion bag 1 mainly includes a main bag sheet 11 and a discharge port 2. As shown in FIG. 2, the discharge port 2 includes a cylindrical mouth portion 21, a rubber stopper 24 made of a rubber elastic material for piercing a needle or a bottle needle, and a cap 23 combined therewith. Further, the cylindrical mouth portion 21 has a ring portion 22 at a portion in contact with the cap 23. The heat-resistant component corresponds to the cylindrical mouth portion 21 and the cap 23, and the non-heat-resistant component corresponds to the ring portion 22.

A cylindrical opening 21 obtained by injection molding polypropylene FG3D manufactured by Mitsubishi Chemical Corporation at a molding temperature of about 240 ° C .;
Mitsubishi Chemical Corporation polypropylene EX-6 and Shell Chemical Company styrene elastomer Clayton G1652 7:
This bag sheet 11 obtained by inflation molding a mixture of 3 (weight ratio) at a molding temperature of 230 ° C. was heat-sealed by a conventional method to obtain a semi-finished product. After filling 500 ml of physiological saline, which is the display volume of the infusion, from the cylindrical mouth, a ring 22 obtained by extruding a Tuffmer A4090 manufactured by Mitsui Petrochemical Co., Ltd. at a molding temperature of 150 ° C. into a cylindrical mouth 21. Fit in,
Rubber stopper 24 made of vulcanized isoprene rubber manufactured in a usual manner
And a cap 23 obtained by injection molding polypropylene FG3D manufactured by Mitsubishi Chemical Corporation at a molding temperature of about 240 ° C. The inner solution did not leak even if it was tilted sideways because it was set to a slightly tighter dimension, but the inner solution leaked when the central part of the transfusion bag main bag sheet 11 was strongly pushed with the palm. This was sterilized in a high-pressure steam sterilizer at 120 ° C. for 20 minutes. After cooling, the central part of the infusion bag main bag sheet 11 was strongly pushed with a palm, and liquid leakage near the outlet was observed (referred to as liquid leakage experiment), but no liquid leakage was observed. After that, the vicinity of the discharge port is cut out with a knife, and the state of the ring portion 22 is observed (referred to as visual observation). As a result, the cylindrical mouth portion 21 and the cap 23 are completely fused over the entire circumference, and When the support 21 and the cap 23 were supported and pulled at a room temperature at a speed of 50 mm / min (referred to as a tensile test), the components 21 were broken from the ring portion 22. Thus, it was confirmed that the components were fused by high-pressure steam sterilization. Tuffmer A manufactured by Mitsui Petrochemical Co., Ltd. is an ethylene-α-olefin copolymer.

(Examples 2 to 8) As shown in Table 1, the materials of each part, the conditions for high-pressure steam sterilization, and the like were partially changed from those in Example 1. Table 1 also shows the evaluation results. As a result, it was confirmed that the components were fused by the high-pressure steam sterilization. Mitsubishi Chemical's Modick and Sumitomo Chemical's Bondyne are ethylene-maleic anhydride copolymers and Nippon Unicar's EE
A is an ethylene-ethyl acrylate copolymer, EVA of Nippon Unicar is an ethylene-vinyl acetate copolymer, Nucrel is an ethylene-methyl methacrylate copolymer of DuPont Mitsui Polychemicals, and Himilan of Mitsui Petrochemical is an ionomer.

[0016]

[Table 1]

(Examples 9 to 12) FIG. 3 is an enlarged sectional view of the vicinity of the discharge port of Examples 9 to 12, which is different from Examples 1 to 8 in the vicinity of the discharge port of the infusion bag. The main bag 11 and the cylindrical mouth 21
Is fused by a conventional heat seal, but the cap 23 and the rubber stopper 25 made of a thermoplastic elastomer are in contact with the ring portion 22. The heat-resistant component of the present invention corresponds to the cylindrical opening 21, the cap 23, and the rubber stopper 25, and the non-heat-resistant component of the present invention corresponds to the ring 22. Table 2 shows each material, high-pressure steam sterilization conditions and evaluation results. In addition, the tensile test was performed by two methods, a method 1 in which the cylindrical mouth portion 21 and the cap 23 are supported and pulled, and a method 2 in which the cap 23 and the rubber stopper 25 are supported and pulled. The rubber stopper 25 is a 1: 1 mixture of Kuraray's styrene elastomer Septon 4033 and Matsumura Petrochemical's process oil Moresco White P-350.
(Weight ratio) and obtained by injection molding at 200 ° C. molding conditions. The materials used for the cylindrical mouth portion and the cap material in Example 11 were polypropylene FG3D manufactured by Mitsubishi Chemical, polyethylene HY430 manufactured by Mitsubishi Chemical, and ethylene-propylene copolymer Tuffmer A4085 manufactured by Mitsui Petrochemical at a ratio of 2: 1.
2 (weight ratio) was obtained by injection molding at a molding temperature of 230 ° C. In addition, Toughmer XR110T is propylene and α
It is an olefin copolymer.

[0018]

[Table 2]

(Embodiment 13) A fourth embodiment of the blood bag is described.
Shown in the figure. Mitsubishi Chemical Linear Low Density Polyethylene SF94
The blood bag main bag sheet 31 obtained by inflation molding of No. 0 and the transition tube connector 32 obtained by injection molding of the same material as that of the cylindrical mouth portion of Example 11 were fused by a conventional heat seal to produce a semi-finished product. I got After a predetermined amount of a CPD liquid of an anticoagulant is added, a polyester elastomer GREAK E200 manufactured by Dainippon Ink and Chemicals, Ltd. is extruded at a molding temperature of 220 ° C., and is extruded at one end of a transition tube 34 at a molding temperature of 170 ° C. The molded ring portion 33 was inserted, set as shown in FIG. 4, and the end of the transfer pipe 34 was sealed and closed. A high-pressure steam sterilization treatment was performed at 120 ° C. for 20 minutes, and a liquid leakage test and a tensile test were performed in the same manner as in Example 1. as a result,
No liquid leakage was observed before the high-pressure steam sterilization, and material destruction of the ring portion was observed in the tensile test, and it was confirmed that the components were fused by the high-pressure steam sterilization.

Embodiment 14 FIG. 4 shows an embodiment of a bag for peritoneal dialysis. The same material as the main bag sheet of the infusion bag of Example 1, the peritoneal dialysis bag main bag sheet 31 obtained by the molding method, and the same material as the cylindrical mouth material of Example 1 were obtained by injection molding. The transition tube connector 32 was fused by a conventional heat seal to obtain a semi-finished product. Put a certain amount of dialysate,
A ring portion similar to that in Example 12 was attached to one end of the transition pipe 34 made of the same material as the bag material, and high-pressure steam sterilization and evaluation were performed in the same manner as in Example 12, and each member was fused. It was confirmed.

(Example 15) Example 1 except that the transition pipe connector 32 was changed to polycarbonate Iupilon S3000R manufactured by Mitsubishi Engineering-Plastics Corporation.
It carried out similarly to 3 and confirmed that each member fused.

(Embodiment 16) FIG. 5 shows an embodiment of fusion welding of two kinds of tubes such as a transfer tube and a catheter. The tube 41 and the tube 42 obtained by the same material and the same molding method as those of the transfer pipe 34 of Example 13 were obtained by coextrusion of Tuffmer A4085 of Mitsui Petrochemical and Admer QB540 of ethylene-maleic anhydride copolymer of Mitsui Petrochemical. The tube connector 44 having the obtained ring portion 43 was set as shown in FIG. Thereafter, high-pressure steam sterilization treatment and evaluation were performed in the same manner as in Example 13, and it was confirmed that each member was fused.

[0023]

According to the present invention, when two or more parts of a medical device are joined, each part made of a thermoplastic resin is fused by performing a closed system high-temperature and high-pressure treatment such as high-pressure steam sterilization. I was able to. Since the closed system is subjected to high-temperature and high-pressure treatment, pressure is uniformly applied to the welded portion, and there is little deformation of parts, and as a result, it is possible to finish beautifully. Furthermore, since the processing which also serves as the sterilization step is performed, the steps are simplified.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall view of an infusion bag.

FIG. 2 is an enlarged sectional view showing the vicinity of an outlet of an infusion bag.

FIG. 3 is an enlarged sectional view showing the vicinity of an outlet of an infusion bag.

FIG. 4 is an enlarged sectional view showing the vicinity of a transition tube of a blood bag or a dialysis bag for peritoneal dialysis.

FIG. 5 is an enlarged sectional view of a matching portion of a tube such as a transition tube or a catheter.

[Explanation of symbols]

1: infusion bag, 2: outlet, 11: book bag sheet, 2
1: cylindrical mouth, 22: ring, 23: cap, 2
4: rubber stopper, 25: rubber stopper, 31: book bag sheet, 32:
Transition pipe connector, 33: Ring section, 34: Transition pipe, 4
1: transition pipe, 42: transition pipe, 43: ring part, 44: tube connector

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tetsuya Otaniuchi 1500 Inoguchi, Nakai-cho, Ashigara-gun, Kanagawa Prefecture Terumo Corporation

Claims (16)

[Claims] 1. A medical device wherein two or more parts made of a thermoplastic resin are fused in a closed system of high temperature and high pressure. 2. The medical device according to claim 1, wherein the high temperature is 105 ° C. or higher, or the high pressure is 1.03 × 10 ⁵ Pa or higher. 3. The high-temperature and high-pressure closed system according to claim 1, wherein the high-temperature and high-pressure closed system is based on a closed system high-pressure steam.
A medical device according to claim 1. 4. The medical device according to claim 1, wherein the high-temperature, high-pressure closed system is sterilized. 5. The sterilization is autoclaving.
A medical device according to claim 1. 6. The difference between the heat distortion temperatures of the two or more parts and the material disposed at least in part between them is 20 ° C.
The medical device according to any one of claims 1 to 5, wherein the materials have heat fusibility. 7. The two or more parts are made of a heat-resistant material that withstands substantially high temperature and high pressure, and at least a part between the two or more parts is substantially under high temperature and high pressure with respect to both materials. 7. The medical device according to claim 6, wherein a non-heat-resistant material having heat-fusibility is arranged. 8. The heat-resistant material is polyethylene, polypropylene, polybutene, cyclic polyolefin, polymethylpentene-1, acrylic resin, polyethylene terephthalate, polybutylene terephthalate, nylon, polyurethane, polycarbonate, fluororesin, and styrene. The medical device according to claim 7, comprising at least one selected from the group consisting of copolymers as components. 9. The medical device according to claim 8, wherein the heat-resistant material includes at least one selected from the group consisting of high-density polyethylene, linear low-density polyethylene, polypropylene, and styrene-based elastomer. 10. The medical device according to claim 9, wherein the heat-resistant material includes high-density polyethylene. 11. The medical device according to claim 9, wherein the heat-resistant material includes polypropylene. 12. The medical device according to claim 9, wherein the heat-resistant material includes polypropylene and a styrene-based elastomer. 13. The medical device according to claim 9, wherein the heat-resistant material contains a styrene-based elastomer and an oil. 14. The non-heat-resistant material is polyethylene,
The medical device according to any one of claims 7 to 13, comprising at least one selected from the group consisting of polypropylene, polybutadiene, a copolymer containing ethylene, propylene, and butadiene as one component, and a hydrogenated product thereof. 15. The non-heat-resistant material is polyethylene,
Ethylene-propylene copolymer or ethylene-butene copolymer or ethylene-α-olefin copolymer such as ethylene-hexene copolymer, ethylene-vinyl acetate copolymer, ethylene-maleic anhydride copolymer, ethylene- Acrylic acid copolymer, ethylene-ethyl acrylic acid copolymer, amorphous polypropylene, propylene-α-olefin copolymer, propylene-maleic anhydride copolymer,
The medical device according to claim 14, comprising at least one selected from the group consisting of polybutadiene. 16. A method for manufacturing a medical device, wherein two or more parts made of a thermoplastic resin are fused in a high-temperature, high-pressure closed system.