JP4435352B2 - Welding method for heat-meltable synthetic resin - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for welding synthetic resins that can be welded to each other by heating a contact portion. For example, in a fine welding target such as a medical tube, a local welding for welding only a limited range is required. It has a remarkable effect.
[0002]
[Prior art]
In a fine synthetic resin that secures sufficient airtightness, such as a balloon catheter that is one of medical tubes and requires flexibility, it is possible to reduce the number of welded parts as much as possible. It is necessary to ensure that flexibility is not impaired.
[0003]
As a method of joining and integrating a plurality of different synthetic resins, (1) joining using an adhesive, (2) joining the target synthetic resin by heating and melting the target synthetic resin from the outside There are methods such as (welding), (3) transmitting ultrasonic waves from the outside to parts to be joined, and heat-melting joining by vibration friction resistance.
[0004]
However, in the method (1), the adhesive layer is hardened and peeled off from the adhesive portion due to the solidification of the adhesive at the adhesive portion, and is particularly possible for medical tubes that require flexibility. Flexibility is important for performance.
In the method (2), heat melting is likely to occur even in the vicinity of the welding target portion, and local heating is extremely difficult for a fine bonding target.
In the method (3), it is difficult to uniformly transmit ultrasonic waves to the welding target site, and in particular, it is difficult to ensure an airtight seal at the welding site.
[0005]
For this reason, in welding of a medical tube or the like, a method is used in which synthetic resin is locally heated and welded using a focused or focused laser beam or the like.
[0006]
[Problems to be solved by the invention]
However, in local heating using a focused or focused laser beam, etc., it is necessary to avoid irradiating the laser beam to other than the welded part because the intensity of the irradiation light of the laser beam used for welding is large. For this purpose, accuracy is required for focusing and focusing of the laser beam. Especially when a double tube such as a medical tube having flexibility is to be joined over the entire circumference, the laser beam is always focused and focused while the joint target portion of the double tube is rotating. Therefore, it is necessary to precisely arrange the rotational position of the double tube and the focus position of the laser beam irradiation light.
For this reason, the burden for the precision improvement of the whole joining apparatus is large, and it raises a price, and there exists a problem that productivity is low.
[0007]
The present invention can reduce the burden of focusing and focusing accuracy of irradiation light and positioning accuracy of a welding target in a synthetic resin welding process, and can secure the positioning accuracy of a bonding site, so that the bonding target is other than the bonding target site. It is an object of the present invention to provide a high-precision welding method that can eliminate the heating and the hindrance of flexibility.
[0011]
[Means for Solving the Problems]
  Claim1 is a heat-meltable synthetic resin that can be welded to each other by heating the contact part.In the welding method,ContactHas a target siteContactSynthetic synthetic resin consists of an inner tube and an outer tube arranged inside and outside, at least,The outer tube is an inner / outer double tube made of a light-transmitting vortex synthetic resin, and is attached to the joining target site on the outer peripheral surface of the inner tube or the inner peripheral surface of the outer tubeContinuous orIs intermittentFor light absorption heat generationColored coating agentThe inner and outer double tubes are applied and abutted in advance, and a light-transmitting cylindrical member is extrapolated to the outside of the inner and outer double tubes and irradiated with heat generation light. Pressure-welding the joint target site by the expansion force associated with the release of the internal strain stress stored during the creation ofThe outer tube and the inner tube are welded.
[0012]
When the synthetic resin to be joined is an inner / outer double pipe and the entire circumference of the pipe is welded continuously or intermittently, it is necessary to irradiate the entire outer circumference of the outer pipe with heat generating light. As a method of irradiation for that purpose, for example, when radiating heat generation light from the fixed position toward the double tube, the irradiation source of the double tube or heat generation light is rotated, or from one irradiation source Irradiate the heat generation light and irradiate the entire outer periphery with a plurality of reflecting mirrors, or place multiple irradiation sources on the outer periphery of the double tube, or irradiate the outer periphery of the double tube There is a method of uniformly irradiating heat generation light using an irradiation source of heat generation light covering the whole.
In the present invention, only the application position of the colored coating agent is heated and welded, so in such an irradiation method, it is not necessary to strictly focus and focus the irradiation light, and the joint portion is focused and focused. Since it is not necessary to exactly match the focal point, high accuracy is not required for the light irradiation position.
Therefore, for example, when the double tube or the irradiation source is rotated, the welding operation can be easily performed without being affected by the mutual displacement between the irradiation source and the peripheral surface that is the bonding target portion.
As a result, it is possible to perform accurate welding simply by performing management related to the intensity of irradiation light and irradiation time to the bonding target site, such as the rotational speed of the double tube or irradiation light source during welding, and bonding in the double tube Process productivity is improved.
[0014]
When the heat generation light is irradiated from the outside, the heat generation light transmitted through the outer cylindrical member of the outer tube heats the synthetic resin at the application portion of the colored coating agent, and the stress of the synthetic resin is released by the temperature rise of the synthetic resin. By the expansion force, the synthetic resins are mutually pressure-bonded from inside and outside, and can be surely welded.
[0015]
  According to a second aspect of the present invention, there is provided an inner / outer double tube in which the synthetic resin having the bonding target portion is composed of an inner tube and an outer tube disposed inside and outside, and at least the outer tube is composed of a light-transmitting synthetic resin. In addition, a colored coating agent for light absorption and heat generation is applied in advance continuously or intermittently to the joining target portion of the outer peripheral surface of the inner tube or the inner peripheral surface of the outer tube, and from the substantially outer peripheral side of the outer tube. A method of welding a heat-fusible synthetic resin in which heat is generated by irradiating a contact portion with heat generation light, and the outer tube and the inner tube are fused to each other,A light transmissive cylindrical member is extrapolated to the outside of the outer tube in a region including a corresponding portion of the bonding target portion, and an internal pressure is applied to the inner tube at the time of irradiation with the heat generation light, or the inner tube and the The outer tube and the inner tube are welded by depressurizing the gap between the outer tube or the inner tube and the cylindrical member.
  Only the inner tube part to which the colored coating agent is applied is expanded by applying pressure, or the colored coating agent is applied by reducing the pressure in the gap between the inner tube and the outer tube, or the gap between the inner tube and the cylindrical member. Since only the joint portion between the inner tube and the outer tube is in contact with each other and the inner tube and the outer tube are securely joined, the portions coated with the colored coating agent are pressure-bonded to each other and reliably joined.
[0016]
When heat generation light is irradiated from the outside of the cylindrical member outside the outer tube, the heat generation light transmitted through the cylindrical member heats the synthetic resin at the application portion of the colored coating agent. The inner tube and the outer tube are pressure-bonded to each other by the pressure applied from the inside of the inner tube while the synthetic resin is softened by the temperature rise of the synthetic resin, or the decompression force outside the inner tube, so that the inner tube and the outer tube are securely bonded.
As the pressure applied from the inside of the inner tube, a physical pressing force by an elastic member or the like, a pressure by a gas such as compressed air, or the like can be used, and decompression can be performed by suction or the like.
[0017]
  According to a third aspect of the present invention, a synthetic resin having a bonding target portion is composed of an inner tube and an outer tube arranged inside and outside, and at least the outer tube is an inner / outer double tube made of a light-vortex synthetic resin. In addition, a colored coating agent for light absorption and heat generation is applied in advance continuously or intermittently to the joining target portion of the outer peripheral surface of the inner tube or the inner peripheral surface of the outer tube, and from the substantially outer peripheral side of the outer tube. A method of welding a heat-fusible synthetic resin in which heat is generated by irradiating a contact portion with heat generation light, and the outer tube and the inner tube are fused to each other,A light-transmitting cylindrical member is extrapolated to the outside of the inner / outer double tube, a deformed core metal is inserted into the inner tube, and the portion of the joining target portion is pressed by the spring pressure of the core metal, It is characterized by irradiating heat generating light and welding the joining target portions.
  When heat generation light is irradiated from the outside of the cylindrical member outside the outer tube, the heat generation light transmitted through the cylindrical member heats the synthetic resin at the application portion of the colored coating agent. The spring pressure of the metal core applied from the inside of the inner tube with the synthetic resin softened by the temperature rise of the synthetic resinByThus, the inner tube and the outer tube are pressure-bonded to each other and reliably joined.
[0018]
  According to a fourth aspect of the present invention, there is provided an inner / outer double pipe in which a synthetic resin having a site to be joined is composed of an inner pipe and an outer contracted pipe arranged inside and outside, and at least the outer pipe is made of a light-transmitting synthetic resin. Yes, a colored coating agent for light absorption and heat generation is preliminarily or intermittently applied to the joining target portion of the outer peripheral surface of the inner tube or the inner peripheral surface of the outer tube, and the outer peripheral side of the outer tube A method of welding a heat-fusible synthetic resin in which the contact portion is irradiated with heating light and heated, and the outer tube and the inner tube are fused to each other,While inserting a core material inside the inner tube, the outside of the outer tubeIs it continuous on the circumference ofFor light-absorbing heat generation intermittently arranged in a ringSaidColored coating agent appliedLight transmissiveA heat-shrinkable tube is extrapolated outside the outer tube so that the application site of the colored coating agent is aligned with the site to be joined, and the heat-shrinkable tube is shrunk so that the heat-shrinkable tube is shrunk. A target part is compressed and the said inner side pipe | tube and the said outer side pipe | tube are welded.
[0019]
When the heat generating light is irradiated from the outside of the heat shrinkable tube, the heat shrinkable tube partially absorbs the heat generating light and is heated to contract. In particular, in a heat-shrinkable tube coated with a colored coating agent, the portion coated with the colored coating agent has good absorption of heat generation light, and is rapidly heated to shrink.
Further, a colored coating agent is applied to the joint target portion of the inner and outer double tubes inside the heat shrinkable tube, and is heated and softened by light absorption.
The softened joint target portion of the inner and outer double tubes receives pressure due to contraction of the outer heat shrinkable tube, is sandwiched between the inner core member and receives pressure, and the inner and outer double tubes are welded to each other.
Here, an appropriate color is selected as the color of the colored coating agent to be applied to the heat-shrinkable tube and the bonding target site according to the melting temperature of the synthetic resin to be welded and the wavelength distribution of the heat-generating light to be irradiated.
[0030]
  As shown in FIG. 8, in the welding method of the heat-meltable synthetic resin that can be welded to each other by heating the contact part, as shown in FIG. Applying the agent, overlapping each other, irradiating heat generation light from one light-transmitting synthetic resin side to heat weld the contact portion of the synthetic resin to be joined, and at the same time, the irradiation direction of the heat generation light A heat diffusive member is brought into contact with the opposite surface side..
  It is possible to prevent a temperature rise other than the welded portion and to prevent damage due to heating of the welded synthetic resin layer due to heat transfer of the heat generated by the light absorption heat generating portion.
[0031]
  Claim6Claims 1 to5In the method for welding a heat-fusible synthetic resin according to any one of the above, the heat generation light is irradiated as unfocused diffused light from an irradiation source toward the joining target site.Be doneIt is characterized by that.
  The present invention does not require much focusing / focusing property of the heat generating light to be irradiated, and even if it is emitted from the irradiation source as unfocused diffused light to the joining target site, the present invention is based on claims 1 to 5.4By applying to the above, it is possible to perform the welding with high positional accuracy of the welding portion and ensuring airtightness.
[0032]
  Claim7Claims 1 to6In the method for welding a heat-meltable synthetic resin according to any one of the above, the heat-generating light has a large proportion of infrared and far-infrared wavelength bands.
  In the present invention, when the synthetic resin is welded, it is necessary that the heat generating light pass through the light-transmitting synthetic resin. For this purpose, the light for heat generation to irradiate may be normal visible light, but further, infrared rays or far-infrared rays having excellent transparency and little heat generation in the light-transmitting synthetic resin, and large heat generation due to the colored coating agent. Is preferably used as the heat generating light.
  Specifically, by using a halogen heater or heating wire having a wavelength that is biased to the far infrared side from visible light, or by passing irradiation light emitted from a visible light or other light source through a wavelength conversion filter layer, The ratio of the outer and far infrared wavelength bands can be increased.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the method for welding a hot-melt synthetic resin of the present invention will be described with reference to the accompanying drawings.
[First welding method]
FIG. 1 shows a first welding method of the present invention. In FIG. 1, 10 and 20 are both transparent nylon as a light-transmitting synthetic resin, and 11 is a light-absorbing coating agent, or light-absorbing ink is applied to the contact surface of the transparent nylon 10 or 20 as a light-absorbing coating agent. Here, it is a printed light absorption marker, which is applied in advance to one of the contact surfaces of the transparent nylon 10 or 20.
After these transparent nylons 10 and 20 are overlapped in a state where the parts to be joined are aligned, the heat generation light L from one side of the transparent nylons 10 and 20 (here, the transparent nylon 10 side) is generated by a halogen heater or the like. Irradiates visible light with many infrared and far-infrared wavelength regions.
In this case, it is not necessary to focus and focus only the light absorption marker 11 on the irradiation of the heat generation light L, and it is only necessary to irradiate the non-focused heat generation light L to the region including the light absorption marker 11. .
[0034]
When the heat generating light L is irradiated, the heat generating light L that is irradiated only on the portion of the contact surface of the laminated transparent nylon 10 and 20 where the light absorbing marker 11 is applied is absorbed and heat is generated. In the part where the light absorption marker 11 is not applied, the heat generating light L is transmitted and does not generate heat.
[0035]
As a result, only the part to which the light absorption marker 11 is applied is welded, and the transparent nylons 10 and 20 are not changed in other parts. Therefore, it is possible to weld only the bonding target portion to which the light absorption marker 11 is applied.
As described above, in the welding method in which the light absorption marker 11 is applied to the transparent nylon 10, 20 and the heat generation light L is irradiated and welded, if the light absorption marker 11 is accurately applied in advance to the bonding target site, It is not necessary to focus or focus when irradiating the heat generating light L, and even with the non-focused heat generating light L, welding with high positional accuracy can be performed. Therefore, productivity is improved.
The synthetic resin on the side not irradiated with the heat generating light L can be welded in the same manner by using colored nylon having light absorption lower than that of the light absorption marker 11 instead of the transparent nylon 20.
[0036]
[Second welding method]
FIG. 2 shows the second welding method of the present invention.
In FIG. 2A, 10 and 20 are transparent nylons, and 30 is a colored light absorption heating element, for example, a metal such as stainless steel.
After the transparent nylons 10 and 20 are overlapped with the joining target part 12 aligned, the light-absorbing heating element 30 is brought into contact with the designated joining target part 12 of the transparent nylon 10 or 20 (here, transparent nylon). 20 side).
Visible light having a large infrared / far-infrared wavelength region is irradiated as the heat generation light L from the side where the light-absorbing heating element 30 is not in contact (here, the transparent nylon 10 side).
[0037]
When the heat generating light L is irradiated, the heat generating light L transmitted through the superimposed transparent nylons 10 and 20 is absorbed by the light absorption heating element 30 to generate heat, and the contact surfaces of the superimposed transparent nylons 10 and 20 are heated. Among them, only the bonding target portion 12 with which the light absorption heating element 30 is in contact is welded by the heat generation of the light absorption heating element 30, but in the portion where the light absorption heating element 30 is not in contact, High permeability, low heat generation and no welding.
[0038]
As a result, it is possible to weld only the bonding target portion 12 with which the light absorption heating element 30 of the transparent nylon 10, 20 is in contact.
As described above, in the welding method in which the light absorption heating element 30 is brought into contact with the transparent nylon 10 and 20 and the heat generation light L is irradiated and welded, the light absorption heating element 30 is accurately brought into contact with the bonding target portion 12 in advance. If this is done, there is no need to focus or focus when radiating the heat generation light L, and even with non-focused heat generation light L, welding with high positional accuracy is performed. be able to.
Therefore, productivity is improved.
[0039]
FIG. 2B shows a welding method developed from the second welding method.
In the welding method shown in FIG. 2B, the same surface as the light-absorbing heating element 30 is formed with a heat-diffusing member 40 that diffuses heat by heat conduction (for example, a metal such as copper having excellent heat conductivity). Thus, the light absorption heating element 30 is brought into contact with the joining target portion 12 of the transparent nylon 10 and 20, and the heat diffusing member 40 is brought into contact with the peripheral portion of the joining target portion 12, respectively.
[0040]
When the heat generation light L is irradiated, the light absorption heating element 30 generates heat due to light absorption and the temperature rises. The heat is quickly conducted to the portion where the heat generating light L is not irradiated, the temperature does not rise, and a temperature difference can be provided.
Therefore, only the joining target part 12 is heated, and the transparent nylons 10 and 20 other than the joining target part 12 are not heated and the physical properties do not change, so that the flexibility can be maintained.
[0041]
[Third welding method]
FIG. 3 shows a third welding method of the present invention.
In FIG. 3A, 10 is transparent nylon, and 50 is colored nylon as a colored light-absorbing synthetic resin. Here, a small piece of colored nylon 50 is joined to a designated position of the transparent nylon 10.
The colored nylon 50 is overlapped and pressed in a state where it is aligned with the joining target portion 12 of the transparent nylon 10, and the heat generation light L is irradiated from the transparent nylon 10 side. In this case, it is not necessary to focus and focus only the joining target part 12 on the irradiation with the heat generating light L, and it is only necessary to irradiate the region including the joining target part 12 with the non-focused heating light L. .
[0042]
When the heat generating light L is irradiated, the contact surface between the colored nylon 50 and the transparent nylon 10 absorbs the heat generating light L and generates heat, and the superimposed transparent nylon 10 and the colored nylon 50 contact each other. The surface is welded.
At this time, in the part where the transparent nylon 10 and the colored nylon 50 are not in contact with each other, the heat generation light L is transmitted, so that no heat is generated.
[0043]
As a result, the colored nylon 50 can be welded at the contact portion with the transparent nylon 10, and other portions of the transparent nylon 10 are not changed.
As described above, in the third welding method, the colored nylon 50 is simply disposed at the welding position of the transparent nylon 10 and brought into contact therewith. Even when the in-focus heat generation light L is used, welding with high positional accuracy can be performed.
[0044]
FIG. 3B shows another welding example of the third welding method of the present invention.
This is a case where only a part of the colored nylon 50 superimposed on the transparent nylon 10 is welded to the transparent nylon 10, and the joining target part 12 of the transparent nylon 10 and the joining target part 51 of the colored nylon 50 are aligned and overlapped. In addition, a covering member 60 having an opening 61 corresponding to the bonding target portions 12 and 51 is covered from the transparent nylon 10 side, and the heat generation light L is irradiated from the transparent nylon 10 side.
Also in this case, it is not necessary to focus and focus only the joining target parts 12 and 51 on the irradiation of the heat generating light L, and the non-focused heat generating light L is applied to the region including the joining target parts 12 and 51. Just irradiate.
[0045]
When the heat generation light L is irradiated, the heat generation light L is transmitted through only the opening 61 portion, and only the contact surface between the colored nylon 50 and the transparent nylon 10 of the bonding target portions 12 and 51 is irradiated. The light L is absorbed to generate heat, and the contact surfaces of the laminated transparent nylon 10 and the colored nylon 50 are welded.
At this time, the other portions covered with the covering member 60 are not irradiated with the heat generating light L, so that the colored nylon 50 does not generate heat.
[0046]
As a result, the transparent nylon 10 and the colored nylon 50 can be welded only at the joining target portions 12 and 51, and the other portions of the transparent nylon 10 and the colored nylon 50 are not changed.
As described above, in the third welding method, the welding position of the colored nylon 50 and the transparent nylon 10 is aligned, and the opening 61 of the covering member 60 is disposed at the joining target portions 12 and 51, and the heating light L There is no need for focusing / focusing at the time of irradiation, and it is possible to weld the bonding target portions 12 and 51 with high positional accuracy even when the non-focused heat generation light L is used.
[0047]
In the first to third welding methods, the synthetic resin melted in the bonding target portions is welded by applying pressure to the synthetic resin during heat generation, for example, by sandwiching the bonding target portions with a transparent glass plate or the like. be able to.
[0048]
(Embodiment 2 of the invention)
Next, the Example which used this invention for manufacture of the balloon catheter 100 as a medical tube is described based on figures.
FIG. 4 is a schematic cross-sectional view showing the balloon catheter 100 in the manufacturing process exaggerated in the radial direction.
In FIG. 4, 110 is an outer tube, 120 is a balloon, 130 is an inner tube, and the inner tube 130 is inserted from an insertion opening 111 of the outer tube 110. Reference numeral 1000 denotes a joint where the outer tube 110 and the inner tube 130 are partially welded in a dot or line shape.
In the balloon catheter 100 having the above configuration, the outer tube 110 and the balloon 120 are the outer tube annular joint portion 101, the inner tube 130 and the balloon 120 are the inner tube annular joint portion 102, and the outer tube 110 and the inner tube 130 are joined by insertion. Each of the portions 103 is welded in a sealed state, and the welding method of the present invention is applied to each of the joint portions 101, 102, 103, and 1000.
[0049]
Hereinafter, regarding the method of welding the balloon catheter 120 and the outer tube 110 or the inner tube 130 in the outer tube annular joint portion 101 and the inner tube annular joint portion 102, the balloon catheter 120 positioned outside in each joint portion 101, 102 is outside. The tube 200, the outer tube 110 or the inner tube 130 positioned inside, will be described as the inner tube 300, and the outer tube annular joint 101 and the inner tube annular joint 102 will be simply replaced with the joint target portion 400, respectively.
[0050]
[Annular joining by the first welding method (part 1)]
The case where the said 1st welding method is applied is demonstrated based on (a) of FIG.
In FIG. 5A, the outer tube 200 and the inner tube 300 are both made of transparent nylon, and here, as a colored coating agent for light absorption and heat generation in advance on the joining target portion 400 on the outer peripheral surface of the inner tube 300. A light absorption marker 104 made of oil-based ink or the like is continuously applied or printed in a ring shape.
Further, as an auxiliary member in the welding process, a core material such as metal is inserted inside the inner tube 300, and a heat shrinkable tube 106 is extrapolated outside the outer tube 200. The light absorption marker 107 is applied continuously or intermittently in a ring shape, and the light absorption marker 107 is arranged in alignment with the position of the light absorption marker 104.
[0051]
When the above-described configuration is integrated, when the non-focused heat generation light L is irradiated from the outside of the heat shrinkable tube 106 while rotating the core member 105 as the rotation axis, the heat generation light L is converted into the light absorption markers 104, 107, heat is generated, and the temperature of each tube 200, 300 rises and melts at the bonding target portion 400, and the heated heat-shrinkable tube 106 contracts at the application portion of the light-absorbing marker 107 of the heat-shrinkable tube 106. Then, apply pressure toward the inside. As a result, the melted joint portions 400 of the tubes 200 and 300 are joined to each other.
[0052]
[Annular joining by the first welding method (part 2)]
Another welding method to which the first welding method is applied will be described with reference to FIG.
In the welding method of FIG. 5B, the heat shrinkable tube 106 similar to “No. 1” is extrapolated outside the outer tube 200, but the light absorption marker 107 is not applied.
When the heat generating light L is irradiated, the heat shrinkable tube 106 is opaque, a part of the heat generating light L is absorbed and heat is generated and contracted, and the heat generating light L transmitted through the heat shrinkable tube 106 is the temperature of the light absorption marker 104. To rise. Since the joining target part 400 is sandwiched between the heat-shrinkable tube 106 and the core material 105, the nylon constituting each pipe 200, 300 at the time of heat generation is pressurized at the joining target part 400. 300 can be welded.
[0053]
[Annular joining by the first welding method (part 3)]
Still another case where the first welding method is applied will be described with reference to FIG.
In the welding method of FIG. 5C, the outer tube 200 and the inner tube 300 are both made of transparent nylon, and the light absorption marker 104 is continuously applied in an annular shape to the joining target portion 400 on the outer peripheral surface of the inner tube 300 in advance. Has been.
As an auxiliary member in the welding process, a glass guide tube 108 is extrapolated outside the outer tube 200, and nothing is inserted inside the inner tube 300, and is communicated with an external compressor or the like that feeds compressed air. is there.
[0054]
When the heating light L is irradiated and the temperature of the joining target portion 400 is increased by heating the light absorption marker 104, compressed air is sent into the inner tube 300, and from the inner tube 300 to the outer tube 200 side. By applying pressure toward the surface, pressure is applied to the melted bonding target portion 400 to be welded. In this case, the glass guide tube 108 or the gap between the outer tube 200 and the inner tube 300 can be similarly welded by reducing the pressure.
[0055]
[Annular Joining by Second Welding Method (Part 1)]
The case where the said 2nd welding method is applied is demonstrated based on (a) of FIG.
In FIG. 6A, the outer tube 200 and the inner tube 300 are both made of transparent nylon.
A core member 105 is inserted inside the inner tube 300 as an auxiliary member in the welding process. The core material 105 has a light-absorbing heating element 105a with poor heat conduction, such as a stainless steel wire, at a portion located in the bonding target portion 400, and a heat conduction member, for example, with a copper wire, at a portion other than the bonding target portion 400. The light-absorbing heating element 105a is sandwiched from both sides by the heat-diffusing member 105b so that the good heat-diffusing members 105b are located respectively.
[0056]
When the heating light L is irradiated while rotating the core member 105 around the rotation axis, the light absorption heating element 105a generates heat by light absorption and is transmitted to the joining target portion 400 of the inner tube 300 and the outer tube 200 on the outer side. Although it is heated and melted, the heat-diffusing member 105b diffuses even if it absorbs the heat-generating light L, so that it generates little heat and does not heat the tubes 200 and 300.
Therefore, only the joining target part 400 can be welded.
[0057]
[Annular Joining by Second Welding Method (Part 2)]
Another case in which the second welding method is applied will be described with reference to FIG.
In the welding method of FIG. 6B, as the core material 105, the light absorption heating element 105 a having a poor thermal conductivity, such as stainless steel, is provided on the part other than the joining target part 400, for example, on the part located on the joining target part 400. For example, a light-absorbing heating element 105a supported by being sandwiched from both sides by a light-transmitting member 105c is used such that a light-transmitting member 105c that transmits light and does not generate heat is positioned.
[0058]
When the non-focused heat generating light L is irradiated from the outside while the core member 105 is rotated about the rotation axis in the state where the above configuration is integrated, the heat generating light L is absorbed by the light absorbing heat generating element 105a and generates heat. In the joining target portion 400, the temperature of each of the tubes 200 and 300 rises and melts, but the light transmitting member 105c transmits the heat generating light L and does not generate heat.
At this time, in the joining target part 400, at least the inner pipe 300 of each of the pipes 200 and 300 is expanded when heat is generated, and the stress accumulated during the manufacture of the pipe is released and pressure is applied to the joining target part 400 to melt each pipe. 200, 300 can be welded. The melted target joint portions 400 of the tubes 200 and 300 are joined to each other.
[0059]
[Annular Joining by Second Welding Method (Part 3)]
Another case in which the second welding method is applied will be described with reference to FIG.
In the welding method of FIG. 7, as the core material 105, the light absorption heating element 105 a with poor heat conduction, such as a stainless steel wire, is provided at a portion located in the bonding target portion 400, and the portion other than the bonding target portion 400 is, for example, The light absorption heating element 105a is sandwiched from both sides so that the heat diffusive members 105b having good heat conductivity such as copper wires are located respectively.
Further, a heat shrinkable tube 106 is extrapolated outside the outer tube (balloon) 200, and a light absorption marker 107 is applied to the heat shrinkable tube 106 continuously or intermittently in a ring shape. Is arranged in alignment with the position of the joining target portion 400.
[0060]
When the heating light L is irradiated while rotating the core member 105 around the rotation axis, the light absorption heating element 105a generates heat due to light absorption and is transmitted to the joining target portion 400 of the inner tube 300 and the outer tube 200 on the outer side and heated. However, since the heat diffusing member 105b diffuses even if it absorbs the heat generation light L, it generates little heat and does not heat the tubes 200 and 300.
At the same time, the light absorption marker 107 of the heat shrinkable tube 106 absorbs light and contracts, and compresses the joining target portion 400 from the outside.
Therefore, only the joining target part 400 can be welded.
The heat-shrinkable tube 106 used in each welding step is removed by excision or the like after the completion of welding, and the core material 105 and the glass guide tube 108 are removed.
[0061]
[About heat generation light]
Synthetic resins such as nylon used in the above welding generally have a light absorption band that absorbs light (electromagnetic waves) of a specific wavelength well, and light absorption occurs when irradiated with light of this wavelength. Generates heat.
The light absorption band of the synthetic resin used in this example is up to about 1.5 μm, and it is difficult to absorb light having a longer wavelength. Therefore, heat of the synthetic resin itself due to light absorption is prevented by using light having a wavelength longer than 1.5 μm.
[0062]
Based on the above viewpoint, the far-infrared halogen heater is used as the heating light L in this embodiment. Generally, a special ceramic coating (black coating) is applied to the surface of the light emitting envelope as a wavelength conversion filter. With this special ceramic coating, 70 to 80% of visible light (wavelength 0.3 μm to 0.7 μm) output is reduced to near / medium far infrared (wavelength 0.7 μm to 3.0 μm), far infrared (wavelength 3.0 μm to 100 μm). ). This means that far-infrared radiation is two to three times that of a halogen heater that does not perform wavelength conversion processing, and the output peak wavelength is 3 μm to 4 μm.
Thereby, in the said Example, it can be made to weld at 170 to 180 degreeC.
[0063]
As the heat generation light, an infrared bulb for an infrared heater or a coil heater using a heating wire can be used.
When heating and welding a double pipe using these halogen heaters or infrared heaters, instead of rotating the double pipe, a plurality of heaters are arranged or the heaters are rotated around the double pipe. Thus, the entire outer periphery may be heated, or a plurality of reflecting mirrors may be used to irradiate the heating light emitted from a single heater from the entire outer periphery of the double tube.
Moreover, when heating and welding a double pipe using a coil heater, the welding location of a double pipe can be arrange | positioned inside a coil, and it can heat uniformly from the whole outer peripheral side of a double pipe.
[0064]
By performing welding with the above configuration, for example, in the balloon catheter 100 illustrated in FIG. 6, the positions of the outer tube annular joint portion 101 and the inner tube annular joint portion 102 are reliably moved away from the main body of the balloon catheter 120. It can be accurately joined to the position. In the joining according to this embodiment, the distance from the edge of the main body to each position of the outer pipe annular joint 101 and the inner pipe annular joint 102 can be accurately positioned at 1.0 to 1.5 mm, and the outer pipe The joining lengths of the annular joint portion 101 and the inner tube annular joint portion 102 could be accurately joined to 1.0 mm.
Thereby, the flexibility of the main body of the balloon catheter 120 was not impaired, and the pressure resistance of the balloon catheter 120 was able to ensure a sufficiently large value (30 atm).
[0065]
In the above embodiment, an example in which the third welding method is applied to the balloon catheter is not shown. However, the inner tube is colored with nylon, and a cylindrical covering member is provided, or the inner tube is colored more than the colored nylon. It can be applied by applying a light-absorbing coating agent with strong absorption.
In the above embodiment, the method of applying pressure to the welded portion by a heat-shrinkable tube or compressed air is shown. However, the pressure is applied to the welded portion by a metal piece supported by an elastic member such as a spring. Also good.
In the said Example, although the Example in the medical tube which has a double tube structure was shown, it is applicable also when welding a sheet-like synthetic resin.
In each of the above examples, nylon is shown as the synthetic resin to be joined, but other synthetic resins may be used as long as they are synthetic resins that can be welded by heating, such as polyethylene, polyethylene terephthalate, polyester, and polyurethane.
[0066]
【The invention's effect】
As described above, in the present invention, by applying a light absorption marker in advance, it is not necessary to focus and focus the heat generating light irradiated at the time of welding, in particular, a fine welding target such as a medical tube. In this case, it is possible to heat and weld only the parts to be joined with high accuracy. Therefore, productivity is improved.
In addition, in order to arrange a light transmissive member that does not absorb heat generation light or a heat diffusive member that diffuses by heat conduction as a core material in a portion adjacent to the bonding target portion, other portions other than the bonding target portion Since it is not heated, the flexibility of the synthetic resin after welding is excellent.
Further, if the wavelength, intensity, and irradiation time of the heat generating light to be irradiated are adjusted according to the synthetic resin to be welded, appropriate welding conditions can be easily selected, and the versatility is excellent.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram for explaining a state in which light-transmitting synthetic resins are welded to each other in the first welding method of the present invention.
FIG. 2 is an explanatory diagram for explaining a state in which light-transmitting synthetic resins related to the second welding method of the present invention are welded to each other, and FIG. Explanatory drawing for demonstrating a mode to perform, (b) is explanatory drawing which shows the state which has arrange | positioned the heat conductive thermal diffusion member around the light absorption heat generating body.
FIG. 3 is an explanatory view showing a method of welding a light-transmitting synthetic resin and a light-absorbing synthetic resin in relation to the third welding method of the present invention, and (a) shows the entire light-absorbing synthetic resin. Explanatory drawing which shows the method to weld, (b) is explanatory drawing which shows the method of welding light-absorbing synthetic resin and light-transmitting synthetic resin partially.
FIG. 4 is a schematic cross-sectional view of a balloon catheter using the welding method of the present invention.
FIG. 5 is an explanatory view when the first welding method of the present invention is used for a balloon catheter, and (a) is an explanatory view showing a welding method using a heat shrinkable tube coated with a core material and a light absorption marker. (B) is explanatory drawing which shows the welding method using a core material and a heat contraction tube, (c) is explanatory drawing which shows the welding method using a glass guide tube.
FIG. 6 is an explanatory view when the second welding method of the present invention is used for a balloon catheter, and (a) is an explanatory view showing a method using a light-absorbing heating element and a heat-diffusing member as a core material. (B) is explanatory drawing which shows the method using the light absorption heat generating body and the light transmissive member for the core material.
7 is an explanatory view of a case where the second welding method of the present invention is a method different from FIG. 6 in which a balloon catheter is used, and a heat absorbing heat generating member and a heat diffusing member are used as a core material, and heat is applied to the outside. It is explanatory drawing which shows the method using a shrinkable tube.
FIG. 8 is an explanatory diagram relating to a synthetic resin welding method according to claim 10;
FIG. 9 is an explanatory diagram relating to a synthetic resin welding method according to claim 5;
[Explanation of symbols]
10 Transparent nylon (light-transmitting synthetic resin)
11 Light absorption marker (colored coating agent)
12 parts to be joined
20 Transparent nylon (light-transmitting synthetic resin)
30 Light absorption heating element
40 Thermal diffusion member
50 Colored nylon (light-absorbing synthetic resin)
60 Covering member
101 Outer tube annular joint (joining target part)
102 Inner pipe annular joint (joining target part)
103 Joint where the inner tube and the outer tube inserted into the outer tube are welded
105a Light absorption heating element
105b Thermal diffusion member
105c Light transmissive member
106 Heat shrinkable tube
110 Outer tube (inner tube)
120 balloon catheter (outer tube)
130 Inner pipe (inner pipe)
200 Outer tube
300 Inner tube
400 Sites to be joined
1000 Joint where the outer tube and inner tube are partially welded in a dot or line shape
L Heat generation light (visible light including many wavelengths in the infrared and far infrared regions)

Claims (7)

In the welding method of heat-meltable synthetic resin that can be welded to each other by heating the contact part,
The target synthetic resin having the target site is composed of an inner tube and an outer tube arranged inside and outside, and at least the outer tube is an inner / outer double tube made of a light-vortex synthetic resin,
The inner and outer double tubes are formed by applying a color coating agent for light absorption and heating in advance or in contact with the joining target portion of the outer peripheral surface of the inner tube or the inner peripheral surface of the outer tube. , Irradiate the heat generating light by extrapolating a light transmissive cylindrical member to the outside of the inner and outer double tubes,
The joining target part is pressure-welded by an expansion force accompanying release of internal strain stress stored when the inner pipe is created when the joining target part generates heat, and the outer pipe and the inner pipe are welded. Welding method for hot-melt synthetic resin. That having a junction target site junction subject synthetic resin consists inner tube disposed inside and outside the outer tube, at least, the outer tube is out double pipe consisting HikariToruuzu synthetic resin,
The bonding target portion of the outer circumferential surface or inner circumferential surface of the outer tube of the inner tube, a continuous or intermittent color with the coating agent for light absorption heating while applying Me pre,
A method of welding a heat-fusible synthetic resin in which heat is generated by irradiating a heat-generating light from a substantially outer peripheral side of the outer tube, and the outer tube and the inner tube are fused to each other.
A light transmissive cylindrical member is extrapolated to the outside of the outer tube in a region including a corresponding portion of the bonding target portion, and an internal pressure is applied to the inner tube at the time of irradiation with the heat generation light, or the inner tube and the by depressurizing the gap between the cylindrical member and the gap portion or said inner tube and outer tube, welding method of heat-fusible synthetic resin you characterized by welding the said inner tube and said outer tube. A synthetic resin having a bonding target portion is composed of an inner tube and an outer tube arranged inside and outside, and at least the outer tube is an inner / outer double tube made of a light-vortex synthetic resin,
While preliminarily applying a colored coating agent for light absorption heat generation to the joining target site of the outer peripheral surface of the inner tube or the inner peripheral surface of the outer tube,
A method of welding a heat-fusible synthetic resin in which heat is generated by irradiating a heat-generating light from a substantially outer peripheral side of the outer tube, and the outer tube and the inner tube are fused to each other.
A light-transmitting cylindrical member is extrapolated to the outside of the inner / outer double tube, a deformed core metal is inserted into the inner tube, and the portion of the joining target portion is pressed by the spring pressure of the core metal, the heat generating light irradiated, welding method of heat-fusible synthetic resin you characterized by welding the bonding target portion. A synthetic resin having a bonding target portion is composed of an inner tube and an outer tube arranged inside and outside, and at least the outer tube is an inner / outer double tube made of a light-vortex synthetic resin,
While preliminarily applying a colored coating agent for light absorption heat generation to the joining target site of the outer peripheral surface of the inner tube or the inner peripheral surface of the outer tube,
A method of welding a heat-fusible synthetic resin in which heat is generated by irradiating a heat-generating light from a substantially outer peripheral side of the outer tube, and the outer tube and the inner tube are fused to each other.
A core material is inserted inside the inner tube, and the outer peripheral surface of the outer tube is coated with the colored coating agent for light-absorbing heat generation continuously or intermittently arranged in an annular shape. Extrapolating the heat-shrinkable tube to the outside of the outer tube so that the application site of the colored application agent matches the site to be joined,
And irradiating the heat generating light, and compressing the bonding target site by contraction of the heat shrinkable tube, welding method of heat-fusible synthetic resin you characterized by welding the said outer tube and said inner tube . In the welding method of heat-meltable synthetic resin that can be welded to each other by heating the contact part,
The colored coating agent for light absorption and heat generation is applied to the bonding target portion of the bonding target synthetic resin, and is superposed on each other, and the heating light is irradiated from the side of one light-transmitting synthetic resin. The heat according to any one of claims 1 to 4, wherein the heat diffusion member is brought into contact with the surface opposite to the irradiation direction of the heat generating light at the same time as the contact portion of the synthetic resin is heated and welded. Method for welding meltable synthetic resin. 6. The heat-meltable synthetic resin weld according to claim 1, wherein the heat generating light is irradiated as an unfocused diffused light from an irradiation source toward the joining target portion. Method. The method for welding a heat-fusible synthetic resin according to any one of claims 1 to 6, wherein the heat generating light has a large proportion of infrared and far-infrared wavelength bands .

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