JP6221514B2 - Method for producing molded thermoplastic resin - Google Patents

Description

  The present invention relates to a method for producing a thermoplastic resin molded body, a thermoplastic resin molded body, and an optical waveguide.

  As a drilling method for a material, machining using a drill and laser processing using a laser beam that is easily absorbed by a workpiece are known (for example, see Non-Patent Document 1).

Hitai, “High Aspect Ratio Small Diameter Drilling with UV Laser (1st Report)”, Journal of Precision Engineering, 2010, 76, 10, p. 1161-1165

  However, in the above method, the formation direction of the holes (voids) is limited to a linear direction from the surface of the workpiece. Therefore, it is impossible to form a bent or curved hole inside the workpiece.

  When it becomes possible to form a bent or curved hole in the resin molded body, the usage of the molded body is expanded. Therefore, there has been a demand for a method for producing a thermoplastic resin molded body including a new processing technique with a high degree of freedom of processing, which can easily form a hole having a desired shape including a hole bent or curved inside.

  This invention is made | formed in view of such a situation, Comprising: It aims at providing the manufacturing method of a thermoplastic resin molded object containing the new processing technique with a high freedom degree of a process. Another object is to provide a thermoplastic resin molded body having holes bent or curved inside. It is another object to provide an optical waveguide having such a thermoplastic resin molded body.

  In order to solve the above-described problem, one aspect of the present invention is to heat the light absorbing material by irradiating light to the light absorbing material, while melting or decomposing the preform with the heated light absorbing material. There is provided a method for producing a thermoplastic resin molded body having a step of moving a light absorbing material inside the preform and forming a void in the preform.

  In one aspect of the present invention, the preform may be a manufacturing method having transparency to the light.

  In one aspect of the present invention, the step of forming the gap may be a manufacturing method in which the light absorbing material is moved in the direction of gravity by gravity received by the light absorbing material.

  In one aspect of the present invention, in the step of forming the gap, the manufacturing method may be such that the direction of movement of the light absorbing material is changed by changing the posture of the preform.

  In one aspect of the present invention, in the step of forming the gap, a manufacturing method may be provided in which the moving speed of the light absorbing material is controlled by changing the intensity of the light.

  In one aspect of the present invention, the method may further include a step of heat-treating the preform with the voids formed after the step of forming the voids.

  In one aspect of the present invention, the light may be a laser beam.

  In one aspect of the present invention, the light absorbing material may be made of a metal material or ceramic.

  In one aspect of the present invention, the method according to any one of claims 1 to 8, further comprising a step of filling the voids with a material having a refractive index higher than that of the preform after the step of forming the voids. The manufacturing method of the thermoplastic resin molding of description.

  Moreover, one aspect of the present invention provides an optical waveguide having a thermoplastic resin molded body obtained by the above-described method for producing a thermoplastic resin molded body.

  Another embodiment of the present invention is a thermoplastic resin molded body having a main body portion provided with a void, wherein the formation direction of the void is bent or curved inside the main body portion. Provide the body.

  In one aspect of the present invention, the thermoplastic resin molded body may be a thermoplastic resin molded body that is an acrylic resin.

  In one aspect of the present invention, the main body portion may be a thermoplastic resin molded body in which the main body portion is light transmissive and the inside of the gap is filled with a material having a higher refractive index than the main body portion.

  One embodiment of the present invention provides an optical waveguide having the thermoplastic resin molded body described above.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of a thermoplastic resin molding including the new processing technique with a high freedom degree of a process can be provided. Moreover, the thermoplastic resin molding which has the space | gap bent or curved inside can be provided. Moreover, the optical waveguide which has such a thermoplastic resin molding can be provided.

It is explanatory drawing of the thermoplastic resin molding of 1st Embodiment. It is a figure which shows the manufacturing apparatus for enforcing the manufacturing method of a thermoplastic resin molding. It is process drawing which shows the manufacturing method of the thermoplastic resin molding of 1st Embodiment. It is explanatory drawing of the thermoplastic resin molding of 2nd Embodiment. It is process drawing which shows the manufacturing method of the thermoplastic resin molding of 2nd Embodiment. It is explanatory drawing of the thermoplastic resin molding of 3rd Embodiment. It is process drawing which shows the manufacturing method of the thermoplastic resin molding of 3rd Embodiment. It is explanatory drawing of the thermoplastic resin molding of 4th Embodiment. It is process drawing which shows the manufacturing method of the thermoplastic resin molding of 4th Embodiment. It is explanatory drawing of the thermoplastic resin molding of 5th Embodiment. It is process drawing which shows the manufacturing process of the thermoplastic resin molding of 5th Embodiment. It is a cross-sectional photograph of the through-hole in the thermoplastic resin molding manufactured in the Example. It is a photograph which shows the opening part of the upper surface side and bottom face side of each through-hole. It is a photograph of the inner wall surface of a through-hole on condition of laser output 2.2W. It is a cross-sectional photograph of the through-hole in the manufactured thermoplastic resin molding. It is a cross-sectional photograph of the through-hole in the manufactured thermoplastic resin molding. It is a cross-sectional photograph of the through-hole in the manufactured thermoplastic resin molding. It is a cross-sectional photograph of the through-hole in the manufactured thermoplastic resin molding.

[First Embodiment]
Hereinafter, a method for producing a thermoplastic resin molded body and a thermoplastic resin molded body according to an embodiment of the present invention will be described with reference to the drawings. In all the drawings below, the dimensions and ratios of the constituent elements are appropriately changed in order to make the drawings easy to see.

  The method for producing a thermoplastic resin molded body of the present embodiment includes: irradiating light to a light absorbing material to heat the light absorbing material; and melting or decomposing the preform with the heated light absorbing material. A step of moving the absorbent material inside the preform and forming a void in the preform.

Further, the thermoplastic resin molded body of the present embodiment is a thermoplastic resin molded body having a main body portion provided with a gap, and the formation direction of the void is bent or curved inside the main body portion. Is.
Hereinafter, it demonstrates in order.

(Method for producing thermoplastic resin molding)
FIG. 1 is an explanatory diagram of a thermoplastic resin molded body 1 manufactured by the method for manufacturing a thermoplastic resin molded body of the present embodiment. In the following description, the thermoplastic resin molded body may be simply abbreviated as “molded body”. Fig.1 (a) is a perspective view of the molded object 1, FIG.1 (b) is arrow sectional drawing in line segment Ib-Ib of Fig.1 (a).

  As shown in FIGS. 1 (a) and 1 (b), the molded body 1 has a through hole 10 (air gap) penetrating from the top surface 1a to the bottom surface 1c.

Examples of the forming material of the molded body 1 include polyolefins such as polyethylene, polypropylene and cyclic polyolefin, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polystyrene, ABS resin (acrylonitrile / butadiene / styrene copolymer), MS resin (methyl). (Methacrylate / styrene copolymer), acrylic resin, vinyl chloride resin, polyamide such as 6-nylon, 6,6-nylon, polycarbonate, polyphenylene ether, polyether sulfone, polysulfone, polyetherimide, polyketone, polyether ketone, poly Mention may be made of ether ether ketone. As a forming material of the molded body 1, a modified body of each resin or a mixture (polymer alloy) of each resin may be used.
As the forming material of the molded body 1, MS resin, acrylic resin, and polycarbonate are preferable since they are excellent in light transmittance, and acrylic resin is more preferable because the molded body 1 is easily melted or decomposed.

  In this specification, “acrylic resin” refers to polymethyl methacrylate (PMMA) or a copolymer of methyl methacrylate and a known acrylate or methacrylate.

  As will be described in detail later, the molded body 1 is formed of the same forming material as that of the molded body 1 and the preformed body (see FIG. 3) before the through holes 10 are formed is locally heated. It is obtained by forming the through-hole 10 by melting or decomposing. Therefore, when the vicinity of the inner wall surface of the through hole 10 of the molded body 1 is compared with the inside of the molded body 1, a decrease in the molecular weight of the forming material and an increase in decomposition products are observed in the vicinity of the inner wall surface of the through hole 10. There is. Alternatively, in the molded body 1, changes in the microstructure such as a disorder in the orientation direction of the forming material and a change in crystallinity may be observed near the inner wall surface of the through hole 10.

  FIG. 2 is an explanatory view showing a production apparatus 100 for carrying out the method for producing a thermoplastic resin molded body of the present embodiment.

  The manufacturing apparatus 100 includes a light irradiation unit 110, a holding unit 120 that holds the preform 1A, and a light absorbing material 200. The light absorbing material 200 is placed on the preform 1 </ b> A held by the holding unit 120. The light L emitted from the light irradiation unit 110 is applied to the light absorbing material 200 and heats the light absorbing material 200. In the manufacturing apparatus 100, the preform 1A is processed by the heated light absorbing material 200.

  The preform 1A is formed of the same forming material as the forming material of the above-described formed body 1, and becomes the formed body 1 by being processed by the manufacturing method of the present embodiment. The preform 1A is light transmissive with respect to the light L. In the present embodiment, an acrylic resin is used as a material for forming the preform 1A, and no intentional coloring that absorbs the light L is performed.

  The light absorbing material 200 is formed of a material that absorbs at least a part of the light contained in the light L and generates heat. Examples of the material for forming the light absorbing material 200 include metal materials and ceramics. As a forming material of the light absorbing material 200, iron, steel, and silicon are preferable because they can easily absorb the light L and can be efficiently formed. Steel is more preferred.

  Further, since the light absorbing material 200 is easy to move in the molten preform 1A, the decomposition gas of the preform 1A can be easily released, and voids can be efficiently formed. Preferably, it is more preferably a sphere having a diameter of 0.1 mm to 100 mm, and still more preferably a sphere having a diameter of 0.5 mm to 10 mm. In the present embodiment, a steel ball having a diameter of 1 mm is used as the light absorbing material 200.

  The light irradiation unit 110 includes a light source 111 that emits light L and a light guide unit 112 that guides the light L to the light absorbing material 200.

  The light L emitted from the light source 111 is applied to the light absorbing material 200 and used to heat the light absorbing material 200. As the light L, both light having a single wavelength and light having a wavelength band including light having a specific wavelength can be used as long as the light absorbing material 200 can be heated. Since the light absorbing material 200 can be efficiently heated, the light L preferably has a single wavelength, and more preferably has a single wavelength of 100 nm to 800 nm. In the present embodiment, the light source 111 is a laser light source that emits green laser light of 532 nm as the light L.

  The light guide unit 112 includes a mirror 113, an expander 114 on which the light L is incident via the mirror 113, and a lens 115 on which the light L is incident via the expander 114.

  The mirror 113 reflects the light L emitted from the light source 111 and changes the traveling direction of the light L to an arbitrary direction.

  The expander 114 has a function of emitting incident parallel light as parallel light with an enlarged beam diameter. As the expander 114, a normally known configuration such as a Galileo type or a Kepler type can be used. The light L incident on the expander 114 has a beam diameter enlarged and is emitted toward the lens 115. If the beam diameter and the energy density of the beam are in a desired range, the expander 114 can be omitted.

  The lens 115 has a function of condensing the light L via the expander 114 toward the light absorbing material 200. As the lens 115, for example, a plano-convex lens or a biconvex lens is used.

  Only one light irradiation unit 110 may be used, or a plurality of light irradiation units 110 may be used in combination. In the case where a plurality of light irradiation units 110 are used, the light absorbing material 200 may be irradiated with the light L at the same time, or the light L may be irradiated separately.

  The holding unit 120 includes an xy stage 121, a z stage 122 provided on the xy stage 121, and an angle adjusting unit 123 provided on the z stage 122. The angle adjusting unit 123 holds the preform 1A.

  As the xy stage 121 and the z stage 122, generally known ones can be used. The spatial position of the preform 1A can be appropriately controlled by the xy stage 121 and the z stage 122. The parallel movement directions in the xy stage 121 and the z stage 122 are referred to as an x-axis direction, a y-axis direction, and a z-axis direction, respectively. That is, the x axis and the y axis are axes orthogonal to each other set on a plane on which the xy stage 121 moves in parallel, and the z axis is an axis orthogonal to the x axis and the y axis.

  The angle adjusting unit 123 includes a rotating unit 123a and a shaft unit 123b extending in the x-axis direction. The rotating portion 123a holds the shaft portion 123b so as to be rotatable around the shaft portion 123b (around the x axis). In the drawing, the rotation direction of the shaft portion 123b is indicated by the symbol A. The preform 1A is held on the shaft 123b. Thereby, the attitude | position of 1 A of preforming bodies can be changed.

  The angle adjusting unit 123 may have a configuration that can rotate about the y-axis or the z-axis. Further, the angle adjustment axis by the angle adjustment unit 123 does not need to be the same axis as the x axis, the y axis, and the z axis, and may be configured to be rotatable with respect to three axes orthogonal to each other.

  FIG. 3 is a process diagram showing a method for producing a thermoplastic resin molded body of the present embodiment. In this process drawing, the manufacturing apparatus 100 shown in FIG. 2 is used as the manufacturing apparatus.

  As shown in FIG. 3A, first, the light absorbing material 200 is placed on the upper surface 1a of the preform 1A, and the light absorbing material 200 is irradiated with light L. The light absorbing material 200 absorbs the light L and gradually generates heat. The light L is irradiated from the lower side in the z-axis direction toward the + z-axis direction via the bottom surface 1c of the preform 1A.

  In addition, when the light L is irradiated in FIG. 3A, the light absorbing material 200 may vibrate. It is considered that this vibration can be suppressed by reducing the intensity of the light L.

  Further, in the upper surface 1a of the preform 1A, a recess for holding the light absorbing material 200 at a predetermined position on the upper surface 1a may be formed in advance so that the placed light absorbing material 200 is not displaced.

  Further, the light absorbing material 200 may be preheated to a temperature lower than the lower one of the melting temperature and the decomposition temperature of the forming material of the preform 1A.

  Next, as shown in FIG. 3 (b), when the temperature of the generated heat absorbing material 200 exceeds the lower one of the melting temperature and the decomposition temperature of the forming material of the preform 1A, the light absorbing material 200 is The preform 1A is melted or decomposed to start moving into the preform 1A while forming the holes 10a (voids) (step of forming the gaps).

  Further, as shown in FIG. 3C, the light absorbing material 200 is pulled downward (gravity direction, -z-axis direction) by gravity, and moves into the preform 1A while extending the hole 10a. When the preform 1A is made of an acrylic resin, the cracked gas G generated by the thermal decomposition of the acrylic resin is released from the holes 10a, so that the holes 10a are satisfactorily extended without blocking the holes 10a.

  At this time, by changing the intensity of the light L applied to the light absorbing material 200, the heating temperature of the light absorbing material 200 can be controlled, and the moving speed of the light absorbing material 200 in the preform 1A can be controlled. . For example, when the intensity of the light L is increased, the temperature of the light absorbing material 200 is improved, so that the moving speed of the light absorbing material 200 is increased. On the other hand, when the intensity of the light L is weakened, the temperature of the light absorbing material 200 is lowered, so that the moving speed of the light absorbing material 200 is slowed down. The intensity of the light L applied to the light absorbing material 200 is preferably 0.01 W to 100 W because the light absorbing material 200 can be efficiently heated and the decomposition of the preform 1A in the portion other than the holes 10a can be suppressed. .1 W to 50 W is more preferable.

  The intensity of the light L is controlled by changing the output of the light source 111 shown in FIG. At that time, when the light L is a continuous wave, the intensity of the light L can be controlled by changing the power supplied to the light source 111. When the light L is a pulse wave, the intensity of the light L can be controlled by changing the duty ratio of the pulse.

When the hole 10a reaches the bottom surface 1c, the light absorbing material 200 falls and is discharged from the formed through hole.
Thus, the molded object 1 shown in FIG. 1 can be formed.

  In addition, it is good also as heating the preform 1A in which the through-hole was formed, and performing the heat processing which removes a thermal distortion (process to heat-process). The heat treatment conditions can be set as appropriate according to the glass transition point of the forming material of the preform 1A. When the preform 1A is made of an acrylic resin, the preform 1A with through holes formed therein is 60 An example of the treatment is heating to from ℃ to 120 ℃ and holding for from 30 minutes to 720 minutes.

  As described above, according to the method for manufacturing a thermoplastic resin molded body of this embodiment, a method for manufacturing a thermoplastic resin molded body including a new processing technique can be provided.

[Second Embodiment]
FIG. 4 is an explanatory view of the thermoplastic resin molded body 2 or the thermoplastic resin molded body 2 manufactured by the method for manufacturing a thermoplastic resin molded body of the present embodiment, and corresponds to FIG. Fig.4 (a) is a perspective view of the molded object 2, FIG.4 (b) is arrow sectional drawing in line segment IVb-IVb of Fig.4 (a).

  As shown in FIGS. 4 (a) and 4 (b), the molded body 2 has a through hole 20 (air gap) penetrating from the upper surface 2a to the side surface 1b. The through hole 20 is bent at a portion indicated by reference numeral 21 inside the molded body 2.

  FIG. 5 is a process diagram showing a method for producing a thermoplastic resin molded body of the present embodiment. Also in this process drawing, the manufacturing apparatus 100 shown in FIG. 2 is used as the manufacturing apparatus.

  FIG. 5A is a diagram corresponding to FIG. 3C of the first embodiment described above. As shown in the figure, the light absorbing material 200 placed on the preform 2A is irradiated with light L in the same manner as in the first embodiment described above, and the preform 2A is generated using the light absorbing material 200 that has generated heat. A hole 20a is formed in the hole.

  Next, as shown in FIG. 5B, the posture of the preform 2A is tilted 90 degrees around the x axis, and the side surface 2b is held downward. The posture control of the preform 2A is performed by the angle adjustment unit 123 of the manufacturing apparatus 100 shown in FIG.

  Here, before changing the posture of the preform 2A, the output of the light source is reduced or the irradiation of the light L from the light source is stopped to reduce the intensity of the light L. Thereby, the temperature of the light absorption material 200 falls. When the temperature of the light absorbing material 200 decreases to a temperature lower than the lower one of the melting temperature and the decomposition temperature of the forming material of the preform 2A, the light absorbing material 200 stops inside the preform 2A. That is, the processing of the preform 2A using the light absorbing material 200 is stopped.

  Next, as shown in FIG. 5C, the light absorbing material 200 is irradiated with light L through the side surface 2b of the preform 2A, so that the holes 20a are formed in the preform 2A as in FIG. 5A. And the hole 20a is extended.

When the hole 20a reaches the side surface 2b, the light absorbing material 200 falls and is discharged from the formed through hole.
In this way, the molded body 2 shown in FIG. 4 can be formed.

  As described above, according to the method for manufacturing a thermoplastic resin molded body of the present embodiment, a thermoplastic resin molded body including a new processing technique with a high degree of freedom of processing, in which a hole bent inside can be easily formed. The manufacturing method of can be provided.

  Moreover, according to the thermoplastic resin molding of the above structures, the thermoplastic resin molding which has the hole bent inside can be provided.

  In the present embodiment, the irradiation of the light L is stopped before the posture of the preform 2A is changed. However, the posture of the preform 2A may be changed while continuing the irradiation of the light L. Good. When such processing is performed, processing by the light absorbing material 200 proceeds even while the posture of the preformed body 2A is changed, so that it is possible to manufacture a molded body having holes that are curved inside.

[Third Embodiment]
FIG. 6 is an explanatory view of the thermoplastic resin molded body 3 or the thermoplastic resin molded body 3 manufactured by the method of manufacturing a thermoplastic resin molded body of the present embodiment, and corresponds to FIG. 6A is a perspective view of the molded body 3, and FIG. 6B is a cross-sectional view taken along line VIb-VIb in FIG. 4A.

  As shown in FIGS. 6 (a) and 6 (b), the molded body 3 has a through hole 30 (air gap) penetrating from the upper surface 3a to the bottom surface 3c. The through hole 30 is bifurcated at a portion indicated by reference numeral 31 inside the molded body 3. The through hole 30 has one opening on the upper surface 3a and two openings on the bottom surface 3c.

  FIG. 7 is a process diagram illustrating a method for producing a thermoplastic resin molded body of the present embodiment. Also in this process drawing, the manufacturing apparatus 100 shown in FIG. 2 is used as the manufacturing apparatus.

  First, as shown in FIG. 7A, the light absorbing material 200 placed on the preform 3A is irradiated with light L by the same method as in the first embodiment, and the heated light absorbing material 200 is changed. The hole 30a is formed in the preformed body 3A by using it. The hole 30a is bent at a portion indicated by reference numeral 31 inside the preformed body 3A, and the forming direction of the hole 30a is inclined obliquely with respect to the bottom surface 3c.

  The preform 3A is held such that the bottom surface 3c is inclined obliquely with respect to the direction of gravity (z-axis direction). When the preliminarily molded body 3A having such a posture is irradiated with light L from the lower side in the z-axis direction toward the + z-axis direction, the light L may be refracted at the bottom surface 3c, and the light absorbing material 200 may not be irradiated. Therefore, in FIG. 7A, the incident angle of the light L with respect to the bottom surface 3c is controlled and adjusted so that the light absorbing material 200 is irradiated. The incident angle of the light L can be calculated from Snell's law using the refractive index of the forming material of the preform 3A.

  When the hole 30a reaches the bottom surface 3c, the light absorbing material 200 falls and is discharged from the formed through hole.

  Next, as shown in FIG. 7B, the light absorbing material 200 is put into the hole 30a, and the posture of the preform 3A is changed so that the light absorbing material 200 does not roll out of the hole 30a. The light absorbing material 200 is disposed at the bent portion shown. And the light L is again irradiated to the light absorption material 200, and the process of 3 A of preforming bodies is restarted.

  Next, as shown in FIG. 7C, the light absorbing material 200 starts to melt or decompose the preform 3A, and the light absorber 200 does not roll out of the hole 30a even if the posture of the preform 3A is changed. After being buried in the preformed body 3A to the extent, the posture of the preformed body 3A is changed so that the formation direction of the holes 30a becomes a desired direction. Thereafter, the light absorber 200 is irradiated with light L through the bottom surface 3c of the preform 3A, thereby forming a hole 30a in the preform 3A and extending the branched hole 30a as in FIG. 7A. To do.

When the branched hole 30a reaches the bottom surface 3c, the light absorbing material 200 falls and is discharged from the formed through hole.
In this way, the molded body 3 shown in FIG. 6 can be formed.

  As described above, according to the method for manufacturing a thermoplastic resin molded body of the present embodiment, thermoplasticity including a new processing technique with a high degree of freedom of processing capable of easily forming holes that are bent inside and further branched. The manufacturing method of a resin molding can be provided.

  Moreover, according to the thermoplastic resin molded body having the above-described configuration, it is possible to provide a thermoplastic resin molded body having bent holes and further branched holes.

[Fourth Embodiment]
FIG. 8 is an explanatory view of the thermoplastic resin molded body 4 or the thermoplastic resin molded body 4 manufactured by the method for manufacturing a thermoplastic resin molded body of the present embodiment, and corresponds to FIG. FIG. 8A is a perspective view of the molded body 4, and FIG. 8B is a cross-sectional view taken along line VIIIb-VIIIb in FIG. 8A.

  As shown in FIGS. 8 (a) and 8 (b), the molded body 4 has a through hole 30 (air gap) penetrating from the side surface 4b to the bottom surface 4c. The through-hole 40 is bent at a portion indicated by a reference numeral 41 inside the molded body 4, and is bifurcated at a portion indicated by a reference numeral 42 inside the molded body 4. The through-hole 40 has one opening on the side surface 4b and two openings on the bottom surface 4c.

  FIG. 9 is a process diagram illustrating a method for producing a thermoplastic resin molded body of the present embodiment. In this process diagram, a manufacturing apparatus in which a set of light irradiation units is further added to the manufacturing apparatus 100 shown in FIG. 2 is used.

  FIG. 9A is a diagram corresponding to FIG. 3C of the first embodiment described above. As shown in the figure, the light absorbing material 200 placed on the preformed body 4A is irradiated with light L in the same manner as in the first embodiment, and the preformed body 4A is generated using the light absorbing material 200 that has generated heat. A hole 40a is formed in the hole.

  Next, as shown in FIG. 9B, the posture of the preform 4A is inclined by 90 degrees, and the bottom surface 4c is held downward. The posture control of the preform 4A is performed by the angle adjusting unit 123 of the manufacturing apparatus 100 shown in FIG. Before changing the posture of the preform 4A, the output of the light source is reduced or the irradiation of the light L from the light source is stopped to reduce the intensity of the light L.

  Next, after further arranging the light absorbing material 201 at a position corresponding to the reference numeral 42 in FIG. 8B, the light absorbing material 200 is again irradiated with the light L having increased intensity via the bottom surface 4c of the preform 4A. Further, the light absorbing material 201 is irradiated with light L1. The light L1 can have the same wavelength and intensity as the light L.

By irradiating the light absorbing material 200 and the light absorbing material 201 with the light L and the light L1, the hole 40a is formed in the preform 4A, and the branched hole 40a is extended. When the branched hole 40a reaches the bottom surface 4c, the light absorbing material 200 and the light absorbing material 201 are dropped and discharged from the formed through hole.
In this way, the molded body 4 shown in FIG. 8 can be formed.

  As described above, according to the method for manufacturing a thermoplastic resin molded body of the present embodiment, thermoplasticity including a new processing technique with a high degree of freedom of processing capable of easily forming holes that are bent inside and further branched. The manufacturing method of a resin molding can be provided.

  Moreover, according to the thermoplastic resin molded body having the above-described configuration, it is possible to provide a thermoplastic resin molded body having bent holes and further branched holes.

[Fifth Embodiment]
FIG. 10 is an explanatory view of the thermoplastic resin molded body 5 of the present embodiment, and is a cross-sectional view corresponding to FIG.
As shown in the figure, the molded body 5 of the present embodiment includes the molded body 3 shown in FIG. 6 and a filling portion 55 filled in the through hole 30 of the molded body 3. .

  The filling portion 55 has a refractive index higher than that of the molded body 3 and is made of a resin material having optical transparency, and fills the inside of the through hole 30 without a gap. Since the refractive index difference between the molded body 3 and the filling portion 55 is effective for use as an optical waveguide, 0.01 to 0.50 is preferable, and 0.02 to 0.30 is more preferable. As a forming material of the filling portion 55, a photo-curing resin is preferable and an ultraviolet-curing resin is more preferable because it is easy to fill the gap.

FIG. 11 is a process diagram showing a manufacturing process of the molded body 5.
First, as shown to Fig.11 (a), the inside of the through-hole 30 of the molded object 3 is filled with the photocurable resin 55A before hardening. Here, an ultraviolet curable resin is used as the photocurable resin 55A.

Next, the molded body 3 is irradiated with ultraviolet rays, and the uncured photocurable resin 55A is cured.
At that time, the entire surface of the molded body 3 may be irradiated with ultraviolet rays, or ultraviolet rays may be irradiated from the openings of the through holes 30 as shown in FIG. In FIG. 11 (b), an ultraviolet ray irradiated by an arrow with a symbol UV is shown. Since the production process is simple and the curability of the photocurable resin 55A is excellent, a method of irradiating the entire surface of the molded body 3 with ultraviolet rays is preferable.

  When it is desired to suppress the deterioration of the molded body 3 as much as possible or when the molded body 3 containing a large amount of an ultraviolet absorber is used, a method of irradiating ultraviolet rays from the opening of the through hole 30 as shown in FIG. Good. Since the inside of the through hole 30 is filled with a photocurable resin 55A having a refractive index higher than that of the molded body 3, when the ultraviolet ray is irradiated from the opening of the through hole 30 as shown in the figure, the through hole 30 is provided. The inner wall of the dome causes total reflection of ultraviolet rays. Therefore, the ultraviolet rays are irradiated to the entire photocurable resin 55 </ b> A while being repeatedly reflected on the inner wall of the through hole 30. As a result, the filling portion 55 obtained by curing the photocurable resin 55A is obtained.

  According to the thermoplastic resin molded body configured as described above, it is possible to provide a thermoplastic resin molded body in which the filling portion 55 can be used as an optical waveguide.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above embodiment, it has been shown that a preform having a bent or curved through-hole is produced by rotating the preform around the x axis during processing. For example, a circular hole or a spiral hole can be formed by processing while rotating around the z axis.

  Moreover, in the said embodiment, although the light absorption material 200 was pulled below with gravity, it is good also as making force other than gravity act on the light absorption material 200. FIG. For example, when the light absorbing material 200 is made of iron or steel, a magnetic force may be applied to the light absorbing material 200 using an electromagnet or a permanent magnet. According to this method, for example, the moving speed of the light absorbing material 200 can be lowered by applying a magnetic force in the direction opposite to the direction of gravity. Moreover, the light absorbing material 200 can be moved in the direction of the magnetic force by applying the magnetic force from the direction intersecting the direction of gravity.

  Moreover, it is good also as raising the moving speed of the light absorption material 200 by blowing in gas toward the inside of a hole from the entrance side of a hole, and pressurizing.

  In the above embodiment, the heating temperature of the light absorbing material 200 is controlled by changing the intensity of the light L applied to the light absorbing material 200. However, the temperature control method for the light absorbing material 200 is as follows. Not limited to this. For example, the light absorbing material 200 may be cooled by blowing gas from the inlet side of the hole toward the inside of the hole. Further, the inner light absorbing material 200 may be indirectly cooled by cooling the preform from the outside of the preform.

  In the above embodiment, the light L is irradiated in the + z-axis direction from the lower side of the preform. However, the present invention is not limited to this, and the light absorbing material 200 may be irradiated from other directions as long as it can be heated. It is good. In that case, if there are a plurality of surfaces that refract and reflect the light L between the light source and the light absorbing material 200, it is difficult to irradiate the light absorbing material 200 with the light L. It is preferable not to employ an optical path through which the light L passes through the wall surface, but to employ an optical path through which the light L passes only through the preform before processing. In such an optical path, since the surface that refracts and reflects the light L is only the outer surface of the preform, refraction and reflection are easy to control and processing is easy.

  Moreover, in the said embodiment, although demonstrated as performing heat processing in order to remove the thermal distortion of a molded object, the objective of heat processing does not need only aim at the removal of thermal strain. For example, in FIG. 3, when an acrylic resin is used as the forming material of the molded body, it is shown that the decomposition gas G generated by thermal decomposition of the acrylic resin is released from the holes during processing. The cracked gas G is liquefied by being cooled and may accumulate inside the hole before being released from the hole. Hereinafter, the substance in which the cracked gas G is liquefied in this way is referred to as a cracked monomer.

  In such a case, by performing heat treatment, the decomposition monomer accumulated in the pores can be vaporized again, and the decomposition monomer can be suitably removed.

  In the above embodiment, the light absorbing material is placed on the upper surface of the preform and processed. However, the light absorbing material is embedded in advance in the preform and the light absorbing material is irradiated with light. The hole may be formed to produce a molded body.

[Example]
EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

In the following examples, the manufacturing apparatus 100 shown in FIG. 2 was used. For each configuration shown in FIG. 2, the following apparatus, light absorbing material, and preform were used.
Light source: Semiconductor laser (Showa Optronics, JUNO5000, wavelength: 532 nm, maximum output: 5 W)
Light guide lens: Plano-convex lens (focal length: 50 mm, condensing diameter: 16 μm)
Light absorbing material: Steel ball (diameter: 1mm)
Pre-formed body: acrylic resin plate (Mitsubishi Rayon Co., Ltd., Acrylite L # 001, thickness: 8 mm)

  In addition, the vicinity of the light absorbing material can be observed using a CCD camera for focusing the laser beam.

  Furthermore, in order to observe the manufactured molded article, a laser microscope (manufactured by Olympus Corporation, LEXT OLS4000) and a scanning electron microscope (manufactured by JEOL Ltd., JSM-6380LT) were used. A 5 × objective lens was used for observation.

Example 1
A molded body having straight through holes was manufactured by the manufacturing process shown in FIG. At that time, the output of the laser beam was changed, and the shape of the through hole to be formed was observed. The output of the laser beam was set to four levels of 1.8 W, 2.2 W, 2.6 W, and 3.0 W. After forming the through holes, the obtained molded body was subjected to a heat treatment heated at 100 ° C. for 30 minutes to remove thermal strain and decomposition gas of the molded body.

  FIG. 12 is a cross-sectional photograph of the through hole in the produced molded body. 12, the upper side of the drawing corresponds to the upper surface 1a of FIG. 1, and the lower side of the drawing corresponds to the bottom surface 1c of FIG.

  FIG. 13 is a photograph showing openings on the upper surface side and the bottom surface side of each through hole shown in FIG. Hereinafter, the opening on the upper surface side of the through hole may be referred to as an “inlet portion”, and the opening on the bottom surface side of the through hole may be referred to as an “outlet portion”.

  FIG. 14 is a photograph of the inner wall surface of the through hole observed under the condition of the laser output of 2.2 W shown in FIG.

  Table 1 below summarizes the experimental results of Example 1. The “central part” in the table refers to a part between the “inlet part” and the “exit part” of the through hole, that is, a part of the through hole inside the molded body.

  First, as shown in FIG. 12, according to the method for producing a thermoplastic resin molded body of the present invention, it was found that a through hole can be formed under any laser output condition. Further, as shown in FIG. 12 and Table 1, it was found that when the laser output was increased, the inner diameter of the through hole was increased.

  Moreover, as shown in FIG. 13, the formed opening was larger than the light absorbing material (steel ball having a diameter of 1 mm) used at both the entrance and exit at any laser output condition. .

  Also, as a result of observation, when a steel ball placed on the preform is irradiated with laser light from the bottom side, the steel ball vibrates while rotating (spinning) around the beam axis of the laser beam, and the preform is processed. I found out that When the laser beam is irradiated to the steel ball, the steel ball is heated and moved into the preform by its own weight while melting the preform, and the processing proceeds. At that time, the steel ball may move vigorously due to the flow of the molten acrylic resin or the flow of the decomposition gas generated by the decomposition of the acrylic resin, and as a result, the steel ball may be rotated and vibrated as described above.

Moreover, as a result of observation, it was found that the outlet portion had a smaller opening diameter than the inlet portion.
At the entrance, the preformed body around the position where the steel ball is placed vibrates vigorously on the surface of the preformed body until the steel ball moves into the preformed body by its own weight while melting the preformed body. Was melting.

  On the other hand, when a part of the steel ball is exposed from the bottom surface of the preformed body at the outlet, it was observed that the rotation gradually weakens because the movement of the steel ball is restricted. Therefore, the steel ball does not melt much of the surrounding preform before passing through the preform on the bottom side, and as a result, the outlet portion has a smaller opening diameter than the inlet portion.

  Furthermore, as shown in FIG. 13, under the conditions of laser power of 1.8 W and 2.2 W, a melt of acrylic resin was adhered to the exit portion.

  Moreover, as shown in FIG. 14, the inner wall of the through-hole was smooth with few irregularities as a whole. Innumerable voids were observed at the outlet portion, which is thought to be because the molten resin near the outlet portion was quenched by the formation of through holes and the falling of the steel balls.

(Example 2)
A molded body having a bent through hole was manufactured by the manufacturing process shown in FIG. The output of the laser beam was 1.8W. After forming the through holes, the molded body was heat treated in the same manner as in Example 1 to remove the thermal strain of the molded body. In the following examples, the laser output and heat treatment conditions were the same as those in Example 2.

  In manufacturing, first, the preform was processed in the z-axis direction by about 4 mm from the surface, and after the preform was rotated 90 degrees, the processing was continued to form a bent through hole.

  FIG. 15 is a cross-sectional photograph of the through hole in the manufactured molded body. As shown in the figure, it was found that according to the method for producing a thermoplastic resin molded article of the present invention, a molded article having a bent through hole can be produced.

(Example 3)
A molded body having a through hole penetrating from the surface to the bottom surface and bent inside was manufactured by the same method as the manufacturing process shown in FIG.

  At that time, as soon as the entire steel ball entered the preform from the start of processing, the posture of the preform was tilted by 20 degrees with respect to the horizontal posture. After processing to the vicinity of the center of the preform, the preform was tilted by −40 degrees with respect to the horizontal posture in a direction opposite to the initial tilt direction. The output of laser light and heat treatment were the same as in Example 2.

  FIG. 16 is a cross-sectional photograph of a through hole in a manufactured molded body. As shown in the figure, it was found that according to the method for producing a thermoplastic resin molded article of the present invention, a molded article having a bent through hole can be produced.

Example 4
After processing in the z-axis direction from the surface of the preform, rotate the preform 90 degrees to continue the process, and further rotate the preform 90 degrees to return it to its original position, thereby bending through A hole was formed.

  FIG. 17 is a cross-sectional photograph of a through hole in a manufactured molded body. As shown in the drawing, it was found that according to the method for producing a thermoplastic resin molded body of the present invention, a molded body having through holes bent at two locations can be manufactured.

(Example 5)
A molded body having a bent through hole was manufactured by the manufacturing process shown in FIG.
FIG. 18 is a cross-sectional photograph of the through hole in the manufactured molded body. As shown in the figure, it was found that according to the method for producing a thermoplastic resin molded article of the present invention, a molded article having a through hole bent inside and further branched can be produced.

  From the above results, it was confirmed that the present invention is a processing technique with a high degree of freedom of processing, and is particularly useful for providing a thermoplastic resin molded body having voids bent or curved inside.

  The thermoplastic resin molded article obtained by the method for producing a thermoplastic resin molded article of the present invention and the thermoplastic resin molded article of the present invention can be suitably used particularly for an optical waveguide.

  1, 2, 3, 4, 5 ... molded body (thermoplastic resin molded body), 1A, 2A, 3A, 4A ... preformed body, L, L1 ... light, 200, 201 ... light absorbing material

Claims (7)

The light absorbing material is irradiated with light to heat the light absorbing material, and the light absorbing material is moved inside the preform while melting or decomposing the preform with the heated light absorbing material, have a step of forming a space in preform,
In the step of forming the gap, the light absorbing material is moved in the direction of gravity by gravity received by the light absorbing material, and the posture of the preform is changed to change the direction in which the light absorbing material is moved. A method for producing a molded thermoplastic resin product. The light absorbing material is irradiated with light to heat the light absorbing material, and the light absorbing material is moved inside the preform while melting or decomposing the preform with the heated light absorbing material, have a step of forming a space in preform,
In the step of forming the void, a method for producing a thermoplastic resin molded body, wherein the moving speed of the light absorbing material is controlled by changing the intensity of the light . The preform, method for producing a thermoplastic resin molded article according to claim 1 or 2 having a transparent to the light. The method for producing a thermoplastic resin molded body according to any one of claims 1 to 3 , further comprising a step of heat-treating the preform formed with the void after the step of forming the void. The method for producing a thermoplastic resin molded body according to any one of claims 1 to 4 , wherein the light is laser light. The method for producing a thermoplastic resin molded body according to any one of claims 1 to 5 , wherein a material for forming the light absorbing material is a metal material or a ceramic. The thermoplastic resin molded body according to any one of claims 1 to 6 , further comprising a step of filling the voids with a material having a higher refractive index than that of the preform after the step of forming the voids. Production method.