JP2011178156A - Laser joining method of resin member, and laser joined body of resin member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laser joining method of resin members which can rapidly implement laser joining by preventing the production of product failure such as the decomposition or carbonization of the resin member even when process variation such as laser output variation or condensing light density variation is produced when the laser joining of the resin members is performed through a light absorber, and the laser joined body of the resin members. <P>SOLUTION: In the laser joining method of the resin members 10a and 10b by bringing at least two resin members 10a and 10b into contact with each other and irradiating the light absorber 20 arranged in the vicinity of the contact surfaces of both resin members 10a and 10b with a laser beam 50 to weld and join the resin members 10a and 10b, at least one of the resin members 10a and 10b includes thermoplastic resin having a glass transition point or melting point of below 300°C and the light absorber 20 has weight reduction quantity thereof measured when the light absorber 20 is heated to 350°C using a differential thermobalance is 40% or above. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a resin member joining method for joining a resin member and a resin member, and a joined body of resin members obtained by joining two or more resin members.

  Conventionally, as a method of joining the resin member and the resin member, a method of welding the resin members with a laser beam has been adopted. When the resin members are welded with laser light, the surfaces of the resin member and the resin member are usually overlapped in a state where they are in contact with each other, and the overlapped portion is irradiated with laser light to form the resin member. A method of forming a welded portion by melting the resin material that constitutes the surface of the resin, and abutting the end portion and the end portion of the resin member, overlapping the other resin members so as to straddle both, and overlapping A method of forming a welded portion by irradiating a portion with laser light to melt a resin material constituting the surface of the resin member is employed.

  In the joining of the resin member by such welding, a light absorber is arranged at a place to be welded, a laser beam is irradiated toward the place where the light absorber is arranged, and the irradiated laser beam is used as a resin member. The resin member is allowed to pass through from the back side to the surface side and reach the light absorber, and the light energy of the laser light is converted into heat energy by absorbing the laser light by the light absorber, thereby allowing the resin member to be interviewed. It is performed by the method of welding. As the laser beam to be irradiated, for example, an infrared laser or a near-infrared laser is used, and as a light absorber disposed at the surface contact portion of the resin member, an infrared region such as carbon black or a porphyrin-based absorber, A substance having an absorption peak in the near infrared region is used (see Patent Documents 1 and 2 below).

  By using such a laser welding method using a light absorbent, even when welding resin members having high transparency to laser light, only the interface of the resin member is heated and melted to melt. It is possible.

  However, in the laser welding method using the light absorber as described above, there are unexpected fluctuations in the manufacturing process such as fluctuations in the output of the laser oscillator, which is a laser light source, and fluctuations in the concentration of light due to surface irregularities of the workpiece. If it happens, the thermal energy supplied from the laser beam may become excessive, and as a result, the resin member that is the workpiece becomes higher than the expected heating temperature, causing decomposition or carbonization reaction. There was a problem of causing defects. In particular, when a resin member whose glass transition temperature Tg or melting point is not so high is used as a bonding target, and laser bonding is performed quickly by increasing the laser output, the above-described problems have become prominent.

JP-T-2002-526261 Japanese Patent No. 3682620

  The present invention has been made in view of such problems of the prior art, and process variations such as laser output fluctuations and light collection density fluctuations occur when laser bonding of resin members through a light absorber. An object of the present invention is to provide a resin member laser joining method and a resin member laser joined body capable of preventing the occurrence of product defects such as decomposition and carbonization of the resin member and performing laser joining promptly. .

  The present invention has been made to solve the above-described problems of the prior art, and the laser joining method for resin members according to the present invention brings two or more resin members into contact with each other in the vicinity of the contact surface. A laser joining method for a resin member in which a resin member is welded by irradiating a laser beam to a disposed light absorber, and at least one of the resin members has a glass transition point of less than 300 ° C. , Or a thermoplastic resin having a melting point, and the light absorber has a weight loss of 40% or more measured by heating to 350 ° C. using a differential thermobalance. It is characterized by.

  Further, in the laser joined body of resin members according to the present invention, two or more resin members are brought into contact with each other, and laser light is irradiated to a light absorber disposed in the vicinity of the contact surface, so that the resin members are welded together. A laser joined body of a resin member, wherein at least one of the resin members is a thermoplastic resin having a glass transition point or a melting point of less than 300 ° C., and the light absorber is a differential thermal balance. The weight loss measured by heating up to 350 ° C. is 40% or more.

  According to the resin member bonding method and bonded body according to the present invention, the light absorber disposed in the vicinity of the contact surface has a weight loss of 40% measured by heating to 350 ° C. using a differential thermal balance. As described above, even when excessive thermal energy is partially supplied by laser irradiation, the light absorber itself is decomposed by the excessive thermal energy. Therefore, when a thermoplastic resin having a glass transition point or melting point of less than 300 ° C. is adopted as any one of the resin members to be laser-bonded, the output fluctuation of the laser oscillator that is a laser light source or the surface of the workpiece Even when unexpected fluctuations such as condensing density fluctuations due to unevenness occur, the thermal energy supplied from the laser beam does not become excessive, suppressing the decomposition and carbonization reaction of the resin member, and the occurrence of product defects Can be prevented.

The side view which shows the laser joining method of the resin member which concerns on 1st embodiment. The side view which shows the joined body of the resin member joined by the laser joining method of 1st embodiment. The side view which shows the laser joining method of the resin member which concerns on 2nd embodiment. The side view which shows the joined body of the resin member joined by the laser joining method of 2nd embodiment. The side view which shows the laser joining method of the resin member which concerns on 3rd embodiment. The side view which shows the joined body of the resin member joined by the laser joining method of 3rd embodiment. The graph which showed the measurement result of the weight loss measured using the differential thermal balance about the light absorber used in the Example and the comparative example.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a side view illustrating a laser bonding method for resin members according to the first embodiment of the present invention, in which reference numerals 10a and 10b represent sheet-shaped resin members, and reference numeral 50 represents laser light. . FIG. 2 is a side view showing a joined body of resin members joined by the laser joining method of the first embodiment.

  As shown in FIG. 1, the resin member laser joining method according to the first embodiment is such that the end portions of the sheet-like resin members 10a and 10b are vertically stacked, and the resin members 10a and 10b are overlapped. The contact surface is melted to perform adhesion. Specifically, the light absorbing agent 20 is applied to the contact surfaces of the resin members 10a and 10b, and the light absorbing agent 20 is heated by irradiating the laser beam 50. The resin member 10a, The contact surface 10b is melted, and the resin members 10a and 10b are joined.

  As the resin members 10a and 10b to be joined, at least one of them may be a resin member provided with a thermoplastic resin having a Tg of less than 300 ° C. or a melting point on its joining surface, and the material is particularly limited. It is not something.

  Examples of the thermoplastic resin having a Tg of less than 300 ° C. or a melting point include polycarbonate resin, polyvinyl alcohol resin, polyethylene resin, polypropylene resin, polyethylene terephthalate resin, polyvinyl chloride resin, triacetyl cellulose, polymethyl methacrylate resin, cyclohexane. Olefin polymer, norbornene resin, polyoxymethylene resin, polyetheretherketone resin, polyetherimide resin, polyamideimide resin, polybutadiene resin, polyurethane resin, polystyrene resin, polymitylpentene resin, polyamide resin, polyacetal resin, polybutylene terephthalate resin And ethylene vinyl acetate resin.

  In addition, Tg is based on JISK7121 (1987), uses a differential scanning calorimeter (Seiko Instruments Co., Ltd., DSC6220), calculates | requires DSC curve by heating up at 10 degrees C / min, and extrapolates from there It can be obtained by determining the glass transition start temperature.

  The thickness of the resin member is preferably 1 μm or more and 10 mm or less. If the thickness of the resin member is less than 1 μm, handling of the resin member becomes difficult, and if it is 10 mm or more, the laser beam is attenuated by light absorption of the resin member, and the effect of reaching the light absorber is reduced. Therefore, there is a concern that productivity will be lowered.

In addition, since the layer to be laser-bonded, that is, at least any one of the resin members 10a and 10b may be the thermoplastic resin, the resin member may be a single layer or a laminated structure. There may be, and there is no restriction | limiting in particular of the material with respect to the other layer laminated | stacked. Further, the thermoplastic resin on the bonding surface and other layers to be laminated may contain any additive such as an antioxidant, a flame retardant, a crosslinking agent, a light stabilizer, a pigment, and a filler. .
However, the resin member disposed on the laser light irradiation side preferably has a light transmittance of 30% or more as a whole, and more preferably has a light transmittance of 50% or more.

The light absorber 20 may be one that has a weight loss of 40% or more measured by heating to 350 ° C. using a differential thermobalance, and is further measured by heating to 400 ° C. It is preferable to employ a material whose weight loss is 60% or more.
By using a light absorber with such physical properties, even if unexpected fluctuations in the manufacturing process occur, such as fluctuations in the output of the laser oscillator or fluctuations in the light collection density due to surface irregularities of the workpiece, It is possible to prevent the absorbent from being heated to 400 ° C. or higher, and to prevent the resin member from being decomposed or carbonized.

  As the light absorber, various pigments and dyes that satisfy the above conditions can be used. Moreover, as a specific method of using the light absorber, a method of forming a layer containing the light absorber on the bonding surface of the resin member, or the light absorber is contained in the bonding surface of the resin member Can be mentioned. In the case of forming a layer on the bonding surface of the resin member, for example, a method of diluting the light absorber with an organic solvent or the like and applying it by a suitable application means can be adopted. Further, the thickness of the layer after drying is preferably 1 μm or less, and more preferably 0.5 μm or less. When the thickness of the layer containing the light absorber exceeds 1 μm, there is a concern that the compatibility of the two resin members to be joined is inhibited. Further, the light absorption by the layer containing the light absorber is preferably 20% or more, and more preferably 30% or more. The coating width of the layer containing the light absorber can be appropriately optimized according to the laser irradiation region.

  Such light absorbers include, for example, carbon black, porphyrin-based absorbents, phthalocyanine-based absorbents, naphthalocyanine-based absorbents, polymethine-based absorbents, diphenylmethane-based absorbents, triphenylmethane-based absorbents, and quinone-based absorbents. And azo-based absorbents and diimmonium salts. As specific examples of these light absorbers, a light absorber commercially available under the trade name “Clearweld” from Gentex, USA can be preferably used. This “Clearweld” manufactured by Gentex, Inc. in the United States has a weight loss of 60% measured by heating to 350 ° C. using a differential thermobalance.

  In addition, the weight loss amount using the differential thermal balance in the present invention is more specifically measured by the method described in the following examples.

  Moreover, as an application | coating means of an absorber, general methods, such as a needle tip dispenser, an inkjet printer, screen printing, a 2 fluid type, a 1 fluid type, an ultrasonic type spray, a stamper, can be used, for example.

  As a method of overlapping the resin members, for example, as shown in FIG. 1, at least two resin members 10 a and 10 b to be joined are arranged on the stage 30 so as to overlap each other, and a pressurizing unit is provided from above. It is preferable to irradiate with the laser 50 in the state which pressed using 40 and this resin member was fixed.

As the pressurizing means, a pressurizing member provided with glass showing high transparency with respect to the laser beam to be used can be suitably used. The pressure strength is preferably 0.5 to 100 kgf / cm ^{2, and} more preferably 1 to 20 kgf / cm ² . The shape of the pressure member is not particularly limited as long as a load can be applied to the laser irradiation portion, and for example, a flat plate, a cylinder, or a spherical shape can be used. The thickness of the pressure member is not particularly limited, but if it is too thin, good pressure cannot be applied due to strain, and if it is too thick, the laser light utilization efficiency decreases. . As a material of the pressure member, for example, fused quartz, non-alkali glass, Tempax, Pyrex, Vycor, D263, OA10, AF45, or the like can be used. In order to increase the utilization efficiency of laser light, the glass member preferably has high transparency with respect to the laser light wavelength to be used. Specifically, the light transmittance is preferably 50% or more, and 70% or more. It is more preferable that

  In addition, from the viewpoint that a large area can be uniformly pressurized and good bonding can be performed over the entire area, a rubber or resin material having good light transmission and cushioning properties between the pressure member and the resin member, etc. It is preferable to insert (hereinafter referred to as interphase material). Examples of the interphase material include rubber-based materials such as silicon rubber and urethane rubber, and resin materials such as polyethylene. The thickness of the interphase material is preferably 50 μm or more and less than 5 mm, more preferably 1 mm or more and less than 3 mm. If it is less than 50 μm, the cushioning property is poor, and if it is 5 mm or more, the utilization efficiency of laser light may be reduced by absorption or scattering. The interphase material preferably has a light transmittance of 30% or more with respect to the laser light wavelength to be used, and more preferably has a light transmittance of 50% or more.

  Further, the material of the stage 30 can be metal, ceramics, resin, rubber or the like. In order to obtain a good bonding state by uniformly pressing a large area, it is preferable to use rubber. Furthermore, the surface of the rubber may be surface-treated for the purpose of increasing the peelability from the sheet after bonding or for the purpose of improving heat resistance, or by placing another resin member or the like on the rubber. Also good.

Further, the laser beam 50 to be irradiated is not particularly limited, and examples thereof include a solid-state laser such as a semiconductor laser, a fiber laser, a femtosecond laser, and a YAG laser, and a gas laser such as a CO ₂ laser.
Among these, a semiconductor laser and a fiber laser are preferable in that a laser beam that is inexpensive and has a uniform in-plane intensity can be easily obtained.

In addition, a continuous wave CW laser (Continuous-Wave Laser) is preferable to a pulsed laser that instantaneously applies high energy in that it facilitates melting while preventing decomposition of the resin itself. .
The laser output, power density, spot size, number of irradiations, scanning speed, and the like can be appropriately selected from the type of resin material, thickness, light absorption rate, and the like.

  Moreover, the contact surfaces of a large area can be welded by moving the position which irradiates the laser beam 50 in the surface direction of a contact surface. Specifically, for example, a large area can be welded by scanning and irradiating a desired welding spot with a spot beam condensed to a desired beam size by a condenser lens. It is also possible to scan only the beam with the laser head fixed by a galvano scanner, and further shape the laser beam into a desired shape by using an optical element such as a diffractive optical element, and collectively without scanning. It is also possible to carry out large area welding.

  Further, in the resin member joining method as described above, it is preferable to perform the welding in such a state that the interface between the resin materials at the welding location disappears by adjusting the irradiation condition of the laser beam 50 and the pressing condition. . By eliminating the interface, sufficient compatibilization can be achieved, the adhesive strength can be improved, and the light transmittance can be improved.

  According to the joining method of the resin member according to the first embodiment, the weight reduction amount measured by heating the joining surface of the resin member 10a and the resin member 10b to 350 ° C. using a differential thermal balance is 40% or more. Because the light absorber is arranged, even if the output of the laser transmitter fluctuates, or the laser beam condensing density fluctuates and the laser light is irradiated excessively, Since an excessive temperature rise of the light absorber is suppressed, the resin member is prevented from being decomposed or carbonized.

  The laser joining method and the laser joined body of the resin member of the present invention are not limited to the first embodiment, and various modifications may be made with respect to the positional relationship of the resin member to be joined, the location of the light absorber, and the like. Is possible. Hereinafter, the second and third embodiments will be described as other embodiments.

FIG. 3 is a side view showing a method of joining resin members according to the second embodiment of the present invention, and FIG. 4 is a side view showing a joined body of resin members joined by the joining method of the second embodiment. is there.
As shown in FIG. 3, in the second embodiment, the end portions of the sheet-like resin members 10a and 10b to be joined are arranged so as to abut on the same plane, and these resin members 10a and 10b are arranged. The other resin member (third resin member) 10c is overlapped so as to overlap both, and the contact surfaces of the third resin member 10c and the resin members 10a and 10b are respectively melted and bonded. . Specifically, the light absorber 20 is disposed so as to be interposed between the resin member 10a and the third resin member 10c and between the resin member 10a and the third resin member 10c, and the light absorption thereof. By irradiating the agent 20 with the laser beam 50, the resin member on each joint surface is welded, and the resin member 10a and the resin member 10b are joined via the resin member 10c.

  Therefore, in the present embodiment, at least one of the resin members 10a and 10b arranged to abut on the same plane, or the third resin member 10c arranged on them, is a bonding surface. What is necessary is just to provide the thermoplastic resin which has Tg of less than 300 degreeC, or melting | fusing point.

  In the second embodiment, the light absorber 20, the laser beam 50, the stage 30, and the pressurizing means 40 can be the same as those in the first embodiment.

FIG. 5 is a side view showing a resin bonding method for resin members according to the third embodiment of the present invention, and FIG. 6 is a bonded body of resin members bonded by the laser bonding method of the third embodiment. FIG.
As shown in FIG. 5, in the third embodiment, the end portions of the sheet-like resin members 10a and 10b to be joined are arranged so as to face each other on the same plane, and these resin members 10a and 10b are arranged. The heat generating medium 11 is overlapped so as to overlap both, and the contact surface between the resin member 10a and the resin member 10b is melted and bonded by the heat supplied from the heat generating medium 11, and then the heat generating medium 11 is peeled To do. At least one of the resin members 10a and 10b includes a thermoplastic resin having a Tg or melting point of less than 300 ° C.
More specifically, in the laser bonding method of the third embodiment, the light absorber 20 is disposed so as to be interposed between the resin member 10a and the heat generating medium 11 and between the resin member 10a and the heat generating medium 11. Then, by irradiating the light absorbent 20 with the laser beam 50, the resin member on the joining surface of the resin member 10a and the resin member 10b is welded, and the resin member 10a and the resin member 10b are joined. The heat generating medium 11 is coated with a light absorbent 20 on its surface, and the energy of the irradiated laser light is transferred to the resin member by converting the energy of the laser light into heat energy. After welding, peel off. As shown in FIG. 5, the heat generating medium 11 may be disposed so that the resin member is sandwiched from both the front and back surfaces, or may be disposed on only one surface of the front and back surfaces.

  EXAMPLES Next, although an Example is given and this invention is demonstrated further in detail, this invention is not limited to a following example, unless the summary is exceeded.

Example 1
The materials used in Example 1 are as follows.
<Materials used>
-Resin member A Material Triacetylcellulose (Fuji Film, Tg 170 ° C, melting point 275 ° C)
Thickness 80μm
Shape 10mm x 50mm
-Light absorber A Gentex company name "Clearweld LD120C" (weight loss measured by heating to 350 ° C using a differential thermal balance is 60%)
・ Laser wavelength 940nm
Output 30W
Spot 2mmφ
・ Pressure member Material Fused quartz glass
Thickness 10mm
・ Stage Silicon rubber (3 mm thick) with polyimide (DuPont, trade name “Kapton” 125 μm thick)

<Measurement of weight loss>
Weight loss was measured using a differential thermal balance (Thermo plus, Rigaku, TG8120 series high temperature type). The measurement conditions were as follows.
・ Temperature increase rate 10 ℃ / min
・ Measurement atmosphere N ₂
・ Measurement temperature 30 ~ 500 ℃
・ Retention time 0 min

  FIG. 7 is a graph showing the measurement results of the weight loss measured for the light absorbent A used in the following Examples and Comparative Examples using the above differential thermal balance.

<Laser bonding test>
The light absorbing agent A was applied to an area of 10 mm width × 10 mm length on the end of the resin member A and dried to form a coating layer of the light absorbing agent A having a thickness of 100 nm. This light-absorbing agent A coating layer had a transmittance of 40% for laser light having a wavelength of 940 nm. The resin member A on which the coating layer is formed is placed on a stage, another resin member A of the same material is overlaid so as to cover the coating layer of the light absorber, and a pressure member 15 kgf / cm from above. Pressed with a pressure of ² . With the pressure member pressed, the laser beam under the above conditions was adjusted to 30 W and 70 W, respectively, and one line scanning irradiation was performed at a speed of 100 mm / s to perform laser bonding of the resin member A.

<Test results>
When the resin member that has undergone the laser joining test was visually observed, it was confirmed that the resin was joined in a good state without being decomposed or carbonized when the laser beam was 30 W or 70 W. It was done.

(Example 2)
<Materials used>
Light absorber B phthalocyanine dye (weight loss measured by heating to 350 ° C using a differential thermobalance is 42%)
The other materials were the same as in Example 1.

<Laser bonding test>
A light absorbent solution is prepared by dissolving the light absorbent B at a ratio of 1% by weight in toluene, and light is applied to the end of the resin member A at an area of 10 mm width × 10 mm length at a coating amount of 20 mL / mm ^2. The absorber solution was applied, and toluene was volatilized and dried to form a light absorber coating layer. Thereafter, laser bonding was performed at laser powers of 30 W and 70 W in the same manner as the laser bonding test of Example 1 above.

<Test results>
When the resin member that has undergone the laser joining test was visually observed, it was confirmed that the resin was joined in a good state without being decomposed or carbonized when the laser beam was 30 W or 70 W. It was done.

(Example 3)
<Materials used>
-Resin member B Material Polyethylene terephthalate (PET, Tg 67 ° C, melting point 243 ° C)
Thickness 50μm
Shape 10mm x 50mm
The other materials were the same as in Example 1.

<Laser bonding test>
Except for using the resin member B, laser bonding with laser outputs of 30 W and 70 W was performed in the same manner as in the laser bonding test of Example 1 above.

<Test results>
When the resin member that has undergone the laser joining test was visually observed, it was confirmed that the resin was joined in a good state without being decomposed or carbonized when the laser beam was 30 W or 70 W. It was done.

Example 4
<Materials used>
-Resin member C Material Polycarbonate (PC, Tg 146 ° C, melting point 253 ° C)
Thickness 70μm
Shape 10mm x 50mm
The other materials were the same as in Example 1.

<Laser bonding test>
Except for using the resin member C, laser bonding at laser outputs of 30 W and 70 W was performed in the same manner as in the laser bonding test of Example 1 above.

<Test results>
When the resin member that has undergone the laser joining test was visually observed, it was confirmed that the resin was joined in a good state without being decomposed or carbonized when the laser beam was 30 W or 70 W. It was done.

(Example 5)
<Materials used>
-Resin member D Material Polyvinyl alcohol (Kuraray, no Tg, melting point 210 ° C.)
Thickness 75μm
Shape 10mm x 50mm
The other materials were the same as in Example 1.

<Laser bonding test>
Other than using the resin member D and changing the laser output to 90 W, laser bonding was performed in the same manner as in the laser bonding test of Example 1 above.

<Test results>
When the resin member which passed the said laser joining test was observed visually, it was confirmed that resin did not raise | generate decomposition | disassembly or carbonization, but was joined in the favorable state.

(Comparative Example 1)
<Materials used>
-Light absorber C, manufactured by Yamamoto Kasei Co., Ltd., trade name “YKR” (weight loss measured by heating to 350 ° C. using a differential thermal balance is 30%)
The same material as in Example 1 was used except that the light absorber was used.

<Laser bonding test>
Except for using the light absorber C as a light absorber, laser bonding tests were performed in the same manner as in Example 1 with laser outputs of 30 W and 70 W.

<Test results>
When the resin member which passed the said laser joining test was observed visually, when the laser beam was 30 W, it was confirmed that favorable joining without decomposition | disassembly of a resin member, carbonization, etc. was achieved. However, when the laser beam was 70 W, the laser-irradiated portion was dotted with black-colored portions, and the joined body emitted a burnt smell. From this, in the test, it was recognized that carbonization of the resin member occurred due to excessive irradiation of the laser.

(Comparative Example 2)
<Materials used>
Light absorber D Ink type manufactured by blending a colorant containing a methine-based oil-soluble dye into a resin (Orient Chemical Industries, trade name “eBIND ink”, heated to 350 ° C. using a differential thermal balance. Measured weight loss is 37%)
The same material as in Example 1 was used except that the light absorber was used.

<Laser bonding test>
Except for using the light absorber D as a light absorber, laser bonding tests were performed in the same manner as in Example 1 with laser outputs of 30 W and 70 W.

<Test results>
When the resin member which passed the said laser joining test was observed visually, when the laser beam was 30 W, it was confirmed that favorable joining without decomposition | disassembly of a resin member, carbonization, etc. was achieved. However, when the laser beam was 70 W, the laser-irradiated portion was dotted with black-colored portions, and the joined body emitted a burnt smell. From this, in the test, as in Comparative Example 1, it was recognized that the carbonization of the resin member occurred due to excessive laser irradiation.

(Comparative Example 3)
<Materials used>
-Resin member E Material Thermoplastic polyimide (Tg: 315 ° C)
Thickness 50μm
Shape 10mm x 50mm
The same material as in Example 1 was used except that the above resin member was used.

<Laser bonding test>
A laser bonding test was carried out in the same manner as in Example 1 except that the resin member E was used as the resin member and the laser output was changed to 90 W.

<Test results>
As a result of the laser joining test, the resin member could not be joined. This is presumably because the resin member E is a highly heat-resistant thermoplastic polyimide, so that the amount of heat for melting it could not be obtained.

(Comparative Example 4)
<Materials used>
・ Resin member E (same as above)
・ Light absorber D (same as above)
Except that the resin member E and the light absorber D were used, the same materials as in Example 1 were used.

<Laser bonding test>
A laser bonding test was carried out in the same manner as in Example 1 except that the resin member E was used as the resin member, the light absorber D was used as the light absorber, and the laser output was changed to 70 W.

<Test results>
As a result of the laser joining test, it was confirmed that high heat-resistant thermoplastic polyimide could be joined. However, when the resin member was visually observed, it was confirmed that the laser-irradiated portion was dotted with black-colored portions. From this, in the test, it was recognized that carbonization of the resin member occurred due to excessive irradiation of the laser.

10a, 10b, 10c Resin member 20 Light absorbent 30 Stage 40 Pressure member 50 Laser light

Claims (2)

A resin member laser joining method in which two or more resin members are brought into contact with each other, and the light absorbing agent disposed in the vicinity of the contact surface is irradiated with a laser beam to weld the resin member and join them.
Weight loss measured when at least one of the resin members is a thermoplastic resin having a glass transition point or melting point of less than 300 ° C., and the light absorber is heated to 350 ° C. using a differential thermobalance A resin member laser joining method, wherein the amount is 40% or more.
Two or more resin members are contacted, and a laser joined body of resin members in which resin members are welded and joined by irradiating laser light to a light absorber disposed in the vicinity of the contact surface,
Weight loss measured when at least one of the resin members is a thermoplastic resin having a glass transition point or melting point of less than 300 ° C., and the light absorber is heated to 350 ° C. using a differential thermobalance A laser joined body of a resin member characterized in that the amount is 40% or more.

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