JP2017165099A - Heat treatment method and resin molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat treatment method capable of melting the whole of a thermoplastic resin whose heat distortion temperature is 130°C or higher in a short time, and capable of obtaining a resin molding whose properties are uniform as possible, and a resin molding method.SOLUTION: A specific thermoplastic resin 4 arranged at the inside of a molding die 3 made of a heat resistant inorganic material and whose heat distortion temperature is 130°C or higher is heated with a specific electromagnetic wave X including a wavelength region of 0.01 to 100 m. In a storage step, a molding die 3 in which the specific thermoplastic resin 4 is arranged at the inside is stored at the inside of the closed space S of a thermal insulation storage box 10 in which a heat generating material 15 is arranged at the inside bottom face 111 in a state where it is contacted with the heat generating material 15. In a heating step, a specified electromagnetic wave X is transmitted through the thermal insulation storage box 10 by an electromagnetic wave irradiation means 20 and is applied on the molding die 3 and the heat generating material 15 to heat-generate the heat generating material 15, and, utilizing the heat transfer from the heat generating material 15, the specific thermoplastic resin 4 in the molding die 3 is heated.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat treatment method and a resin molding method in which a thermoplastic resin in a mold is heated by a specific electromagnetic wave including a wavelength region of 0.01 to 100 m.

Conventionally known injection molding methods, blow molding methods, extrusion molding methods, press molding methods, and the like are known as thermoplastic resin molding methods. In these molding methods, the thermoplastic resin is melted by a heater, and then the molten thermoplastic resin is molded into a required form and cooled.
In recent years, as a molding method other than the above-described molding method, the thermoplastic resin filled in the mold cavity is irradiated with microwaves through the mold to heat and melt the thermoplastic resin, and then An electromagnetic wave irradiation molding method for cooling and solidifying a thermoplastic resin in a cavity has been proposed (see, for example, Patent Document 1).

International Publication No. 2012/133053

  A thermoplastic resin having a heat distortion temperature of 130 ° C. or higher that indicates a temperature that can be deformed by heat (hereinafter also referred to as “specific thermoplastic resin”) cannot be molded unless heated to 130 ° C. or higher. It is a difficult thermoplastic resin. When this specific thermoplastic resin is heat-treated with microwaves, it has been found that there are the following problems.

  Specifically, when the specific thermoplastic resin in the mold is heated by irradiating microwaves into the mold in which the specific thermoplastic resin is arranged, air or the like existing around the mold It was found that the mold was locally cooled by this gas. Therefore, it turned out that the specific thermoplastic resin in a shaping | molding die is cooled locally, and the whole specific thermoplastic resin is not heated uniformly. It has also been found that the specific thermoplastic resin cannot be heated sufficiently only by irradiating the specific thermoplastic resin with microwaves through the mold.

  Moreover, in the conventional electromagnetic wave irradiation molding method, it takes a long time to heat the entire specific thermoplastic resin in the mold to 130 ° C. or higher. Therefore, depending on the portion of the specific thermoplastic resin after heating, there is a possibility that a thermal history such as scorching due to excessively high temperature remains. In addition, the central portion of the specific thermoplastic resin may not be completely melted.

  Therefore, an object of the present invention is to melt the entire thermoplastic resin having a heat distortion temperature of 130 ° C. or higher with a specific electromagnetic wave including a wavelength region of 0.01 to 100 m in a short time, and the properties are as uniform as possible. An object of the present invention is to provide a heat treatment method and a resin molding method capable of obtaining a simple resin molded product.

One embodiment of the present invention heats a thermoplastic resin having a thermal deformation temperature of 130 ° C. or higher, which is disposed in a mold made of a heat-resistant inorganic material, by a specific electromagnetic wave including a wavelength region of 0.01 to 100 m. A heat treatment method,
A housing step of housing the molding die in which the thermoplastic resin is disposed in a closed space of a heat insulating housing box in which the heat generating material is disposed on the inner bottom surface, in a state in contact with the heat generating material;
The specific electromagnetic wave is transmitted through the heat insulating housing box to irradiate the mold and the heat generating material to heat the heat generating material, and heat transfer from the heat generating material is used to heat the heat in the mold. And a heating step of heating the plastic resin.

Another aspect of the present invention uses the heat treatment method,
After performing the heating step, the resin molding method includes performing a cooling step of cooling and solidifying the thermoplastic resin in the molding die to obtain a resin molded product to which the inner surface shape of the molding die is transferred. .

In the heat treatment method, a thermoplastic resin (referred to as a specific thermoplastic resin) having a heat deformation temperature of 130 ° C. or higher is heated using a heat insulating container in which a heat generating material is disposed on the inner bottom surface. The heat generating material generates heat by absorbing the specific electromagnetic wave.
In the housing step, the molding die in which the specific thermoplastic resin is disposed is housed in the closed space of the heat insulating housing box. At this time, the bottom of the mold comes into contact with the heat generating material on the inner bottom surface of the heat insulating container.

  Next, in the heating step, a specific electromagnetic wave including a wavelength region of 0.01 to 100 m is transmitted through the heat insulating housing box and irradiated to the mold and the heat generating material. At this time, the heat generating material generates heat by absorbing the specific electromagnetic wave, and the specific thermoplastic resin in the mold is heated using heat transfer from the heat generating material on the inner bottom surface of the heat insulating container. Thereby, the specific thermoplastic resin is easily heated, and the heating time can be shortened.

  Moreover, in order to melt the specific thermoplastic resin in the mold, it is necessary to heat and maintain the specific thermoplastic resin at a heating attainment temperature of 130 ° C. or higher. The ultimate heating temperature is appropriately determined according to the type of the specific thermoplastic resin, the size and shape of the resin molded product molded from the specific thermoplastic resin, and the like.

  In the heat treatment method, since the mold is accommodated in the closed space of the heat-insulating container, gas such as air existing around the mold in the closed space exists outside the heat-insulating container. It is isolated from gases such as air. In the heating step, when the specific thermoplastic resin in the mold is melted by the specific electromagnetic wave, the gas in the closed space is heated by the mold, and the temperature of the gas in the closed space is outside the heat insulating container. It becomes hotter than gas.

  Thereby, it is possible to prevent the mold from being cooled by the gas in the closed space, and it becomes easy to maintain the mold and the specific thermoplastic resin in the mold at a heating reached temperature of 130 ° C. or higher. Therefore, the specific thermoplastic resin in the mold is hardly locally cooled, and the entire specific thermoplastic resin can be heated as uniformly as possible. As a result, it is not necessary to continue irradiation with the specific electromagnetic wave longer than necessary, and it is possible to prevent the specific thermoplastic resin from having a heat history such as burning due to being overheated.

  Further, in the heating step, the specific thermoplastic resin in the mold is heated and melted from the portion near the bottom of the mold first, and is sequentially melted toward the portion far from the portion near the bottom. Thereby, the whole including the central part of the specific thermoplastic resin can be melted, and an unmelted part can be prevented from remaining in the central part of the specific thermoplastic resin. Then, after the heating step, when the specific thermoplastic resin is cooled, a resin molded product having as uniform a property as possible can be obtained.

  In the resin molding method, after performing the heating step, the cooling step is performed to cool and solidify the thermoplastic resin in the molding die, and the inner shape of the molding die is transferred. A uniform resin molded product can be obtained as much as possible.

  Therefore, according to the heat treatment method of one embodiment of the present invention and the resin molding method of another embodiment of the present invention, the entire thermoplastic resin having a heat deformation temperature of 130 ° C. or higher can be melted in a short time. In addition, a resin molded product having as uniform a property as possible can be obtained.

  Although it is assumed that the heat distortion temperature of the specific thermoplastic resin used in the heat treatment method is 130 ° C. or higher, the heat deformation temperature of the specific thermoplastic resin is preferably 140 ° C. or higher, preferably 150 ° C. or higher. It is particularly preferred that Many thermoplastic resins having a heat distortion temperature of 130 ° C. or higher are called super engineering plastics (super engineering plastics, heat resistant engineering plastics or super heat resistant resins).

  The thermoplastic resin having a heat distortion temperature of 130 ° C. or higher is not particularly limited. For example, polysulfone (PSU; 175 ° C.), polyether sulfone (PES; 210 ° C.), polyether ether ketone (PEEK; 152 ° C.) , Polyamideimide (PAI; 260 ° C), polyetherimide (PEI; 200 ° C)), polyphenylene sulfide (PPS; 136 ° C), and the like. In addition, the numerical value in a parenthesis shows heat deformation temperature.

  The thermal deformation temperature (deflection temperature under load) is one of the indices for evaluating the heat resistance of a synthetic resin. When the temperature is raised with a load applied to the synthetic resin, the deflection that occurs in this synthetic resin Is a temperature at which the magnitude of is constant, and is a value measured according to JIS K7191-3.

Explanatory drawing which shows the cross section when the heat processing apparatus concerning Embodiment 1 is seen from the side. Explanatory drawing which shows an example of the resin molded product concerning Embodiment 1. FIG. Explanatory drawing which shows the cross section when the other heat processing apparatus concerning Embodiment 1 is seen from the side. Explanatory drawing which shows the cross section when the heat processing apparatus concerning Embodiment 2 is seen from the side. Explanatory drawing which shows the cross section when the heat processing apparatus concerning Embodiment 2 is seen from upper direction. Explanatory drawing which shows the state which arrange | positions the thermoplastic resin in the shaping | molding die concerning Embodiment 2 when it sees from a side. Explanatory drawing which shows the state which arrange | positions a shaping | molding die in the heat insulation accommodation box concerning Embodiment 2 when it sees from a side. Explanatory drawing which shows the cross section when the other heat processing apparatus concerning Embodiment 2 is seen from the side. Explanatory drawing which shows the shaping | molding die which performs the conventional electromagnetic wave irradiation shaping | molding concerning Embodiment 2. FIG.

A preferred embodiment of the heat treatment method and the resin molding method described above will be described with reference to the drawings.
<Embodiment 1>
In this embodiment, the heat treatment apparatus 1 and the mold 3 used in the heat treatment method and the resin molding method will be described. In the heat treatment method and the resin molding method, as shown in FIG. 1, the heat treatment apparatus 1 including the heat insulating container 10 and the electromagnetic wave irradiation means (electromagnetic wave irradiation unit) 20 and the heat distortion temperature are 130 ° C. or higher. A mold 3 made of a heat-resistant inorganic material on which a thermoplastic resin 4 (referred to as a specific thermoplastic resin 4) is disposed is used. A cavity 31 for disposing the specific thermoplastic resin 4 is formed inside the mold 3. The mold 3 is disposed in the heat insulating container 10.

  The electromagnetic wave irradiation means 20 generates a specific electromagnetic wave X including a wavelength region of 0.01 to 100 m. The heat insulating storage box 10 has a property of transmitting the specific electromagnetic wave X and has a closed space S in which the molding die 3 is stored. A heat generating material 15 having a property of generating heat by absorbing the specific electromagnetic wave X is disposed on the inner bottom surface 111 of the heat insulating container 10. The inner bottom surface 111 refers to the upper surface of the bottom wall portion of the heat insulating housing box 10. The electromagnetic wave irradiation means 20 is disposed outside the heat insulating housing box 10 and configured to irradiate the molding die 3 and the heat generating material 15 with the specific electromagnetic wave X through the heat insulating housing box 10.

  Here, the “specific electromagnetic wave X including the wavelength region of 0.01 to 100 m” refers to an electromagnetic wave including at least a part of the wavelength region of 0.01 to 100 m as described later. In other words, the specific electromagnetic wave X should just contain any wavelength within the wavelength range of 0.01-100 m. Moreover, this specific electromagnetic wave X should just contain a microwave or a high frequency, and does not need to be an electromagnetic wave containing the whole wavelength range of 0.01-100 m. Further, it is not necessary that the wavelength of the specific electromagnetic wave X is fixed to a single value.

  As shown in FIG. 1, the heat-insulating storage box 10 of this embodiment includes a heat-insulating container 11 and a heat-insulating lid 12 that closes an opening 110 of the heat-insulating container 11. A projecting portion 13 having a planar shape that fits the opening 110 of the heat insulating container 11 is formed on the back surface of the heat insulating lid 12. The protruding portion 13 of the heat insulating lid 12 is arranged in a state of entering the heat insulating container 11.

  If the heat insulating housing box 10 has a function of shutting off the gas in the heat insulating housing box 10 and the gas outside the heat insulating housing box 10 when the mold 3 is housed in the closed space S. Good. The heat insulating container 11 and the heat insulating lid 12 can be formed in various shapes and combined in various ways. The heat insulating storage box 10 may have a structure in which two container parts are combined, for example.

  A heat generating material (auxiliary heating member) 15 that generates heat by absorbing the specific electromagnetic wave X is disposed on the inner bottom surface 111 of the heat insulating housing box 10. The heat generating material 15 can be a sheet-like or plate-like member provided on the inner bottom surface 111 of the heat-insulating storage box 10. The heat generating material 15 of this embodiment is disposed on substantially the entire inner bottom surface 111 of the heat insulating container 11, and the molding die 3 is placed on the heat generating material 15.

  In this embodiment, the specific thermoplastic resin 4 in the molding die 3 placed on the inner bottom surface 111 of the heat insulating container 11 is far from a portion near the inner bottom surface 111 using heat transfer from the heat generating material 15. Melt sequentially toward the site. Further, according to the thermal characteristics such as the heat deformation temperature, the melting start temperature, and the melting point of the specific thermoplastic resin 4 disposed in the mold 3, the location where the heat generating material 15 is disposed on the inner bottom surface 111, the heat generating material 15. It is possible to change the area or the like for arranging the. For example, the heat generating material 15 can be provided not only on the inner bottom surface 111 but also on the inner side surface of the side wall of the heat insulating container 11.

  When the specific thermoplastic resin 4 has a property of generating heat by absorbing the specific electromagnetic wave X as the temperature rises, the effect of providing the heat generating material 15 on the inner bottom surface 111 of the heat insulating container 11 is remarkable. Is obtained. When the entire area of the inner bottom surface 111 in the heat insulating container 11 is 100%, the heat generating material 15 is preferably arranged in a range where the area of the inner bottom surface 111 is 50% or more, and the area of the inner bottom surface 111 is 80%. It is more preferable to arrange in the above range, and it is particularly preferable to arrange in the range where the area of the inner bottom surface 111 is 95% or more.

  Moreover, the heat processing apparatus 1 may have a temperature measuring means for measuring the temperature in the heat insulating housing box 10. In this case, the control unit that controls the irradiation operation of the electromagnetic wave irradiation unit 20 can adjust the irradiation time of the specific electromagnetic wave X by the electromagnetic wave irradiation unit 20 based on the measurement value of the temperature measurement unit.

  The heat insulating container 10 is made of a material having heat insulating properties and heat resistance, and having transparency to the specific electromagnetic wave X. It is preferable to use a material having a thermal conductivity at 25 ° C. of 1.0 W / (m · K) or less as a material constituting the heat insulating container 10. The heat insulating storage box 10 has a property of transmitting the specific electromagnetic wave X and a property of suppressing heat transfer between the gas inside the heat insulating storage box 10 and the gas outside. Examples of materials having such properties include metal oxides (including ceramics), resins, and the like, excluding metals. Specific examples of the material constituting the heat insulating container 10 include ceramics such as alumina, gypsum, glass, silicone rubber, cork, mullite, zirconia, cement, ceramics, and the like.

  The thickness of the side wall part (peripheral wall part) and the bottom wall part of the heat insulating container 11 in the heat insulating container 10 and the thickness of the heat insulating lid 12 can be set to 5 to 30 mm, for example. These thicknesses are not particularly limited as long as sufficient heat insulation is ensured between the inside and the outside of the heat insulating container 10.

  The volume of the closed space S of the heat-insulating storage box 10 can be set to be twice or more the volume of the mold 3, and is preferably 10 to 300 times the volume of the mold 3. When the volume of the closed space S is excessively small, the heat insulating effect by a gas such as air in the closed space S is reduced, and the specific thermoplastic resin 4 when the specific thermoplastic resin 4 is heated through the molding die 3. It becomes difficult to equalize the temperature. On the other hand, when the volume of the closed space S is excessive, the gas in the closed space S may convect, and the heat insulating effect by the heat insulating container 10 may be weakened.

  The heat generating material 15 is made of a material that generates heat by absorbing the specific electromagnetic wave X. The material constituting the heat generating material 15 is a substance having a dielectric power factor (dielectric loss tangent, tan δ) at 30 ° C. and 60 Hz of 0.01 or more in the base material (hereinafter referred to as “high dielectric power substance”). It is preferable to use those containing. As the substrate, ceramics, rubber, heat resistant resin, or the like can be used.

The heat generating material 15 may be formed as a whole or a part of a wall portion such as a bottom wall portion of the heat insulating container 11 by mixing a material having a high dielectric power factor with the material constituting the heat insulating container 11. In this case, the whole or a part of the heat insulating container 11 itself becomes the heat generating material 15.
Examples of the high dielectric constant material include graphite, silicon carbide, ferrite, barium titanate, carbon black, graphite, and manganese dioxide. These high dielectric constant materials can be used singly or in combination of two or more.

Further, the heat generating material 15 may be a plate obtained by applying a high dielectric power factor substance together with a glaze to a base material and baking it.
The content ratio of the high dielectric force substance in the material constituting the heat generating material 15 is usually 5 to 90% by volume, preferably 10 to 70% by volume, more preferably 13 to 50% by volume, and still more preferably 15 to 35%. % By volume.

  The electromagnetic wave irradiation means 20 of this embodiment is disposed outside the heat insulating housing box 10. Although it is necessary to increase the size of the heat insulating storage box 10, the electromagnetic wave irradiation means 20 can be arranged inside the heat insulating storage box 10 or in the wall portion.

  As the electromagnetic wave irradiation means 20, a specific electromagnetic wave X, specifically, an object that irradiates a microwave (electromagnetic wave having a wavelength of 0.01 to 1 m) or a high frequency (electromagnetic wave having a wavelength of 1 to 100 m) is used. Here, when the microwave and the high frequency are shown in terms of frequency, the microwave is about 30 GHz to about 300 MHz, and the high frequency is about 300 MHz to about 3 MHz. Generally, frequencies around 13.56 MHz (about 22.1 m), 27.12 MHz (about 11.1 m), 40.18 MHz (346 m), 2450 MHz (about 0.122 m) due to legal regulations due to electromagnetic leakage Electromagnetic waves are used.

  The specific electromagnetic wave X irradiated from the electromagnetic wave irradiation means 20 is appropriately selected from a wavelength of 0.01 to 100 m in consideration of the type and shape of the specific thermoplastic resin 4 and the like, the material and size of the heat generating material 15 and the like. be able to. As such a specific electromagnetic wave X, a microwave of 1000 MHz (wavelength: 0.3 m) to 10 GHz (wavelength: 0.03 m) is used from the viewpoint that the occurrence of sparks is small and the prevention of electromagnetic leakage is easy. A frequency around 2450 MHz is particularly preferable. Moreover, as the electromagnetic wave irradiation means 20, a thing with a rated output of 100-15000W can be used, and it is more preferable to use a thing with a rated output of 500-3000W.

  The electromagnetic wave irradiation means 20 of this form is arrange | positioned in the position facing the outer wall surface of the heat insulation cover body 12 of the heat insulation storage box 10. FIG. The electromagnetic wave irradiation means 20 can also be disposed at a position facing the outer wall surface of the side wall portion or the bottom wall portion of the heat insulating container 11. Moreover, depending on the case, the several electromagnetic wave irradiation means 20 can also be arrange | positioned facing the position where the outer wall surface of the heat insulation storage box 10 differs.

  As shown in FIG. 1, in the resin molding method of this embodiment, the specific thermoplastic resin 4 in the cavity 31 of the mold 3 is melted by irradiating the mold 3 with the specific electromagnetic wave X from the electromagnetic wave irradiation means 20. Thereafter, by cooling the specific thermoplastic resin 4, a resin molded product such as a resin block is formed in the cavity 31.

  The cavity 31 of the molding die 3 can be shaped according to the product shape of the resin molded product molded by the specific thermoplastic resin 4. Moreover, the cavity 31 of the shaping | molding die 3 can also be made into the shape along the raw material shape larger than a product shape before becoming a product shape. This material shape can be made into arbitrary shapes, such as a rectangular parallelepiped, a cylindrical shape, and an annular shape, for example. In addition, after molding a resin molded product having a material shape, the resin molded product can be formed into a product shape by cutting. For example, as shown in FIG. 2, the resin molded product is a three-dimensional resin molded product 5 having a predetermined cross-sectional shape in a plane and a predetermined cross-sectional shape continuing in a direction orthogonal to the plane. You can also

The mold 3 of this embodiment has a property of transmitting at least a part of the specific electromagnetic wave X. The material constituting the mold 3 can be various ceramic materials. Examples of the ceramic material include ceramics such as alumina, gypsum, glass, silicone rubber, cork, mullite, zirconia, cement, and ceramics. In the case where the mold 3 is formed from a ceramic material, the heat insulation and durability of the mold 3 can be enhanced.
Note that the mold 3 can also be formed of a rubber material such as silicone rubber or fluorine rubber. Moreover, the form of the specific thermoplastic resin 4 arrange | positioned in the shaping | molding die 3 may be a pellet form, or may be a powder form.

  At least a part of the mold 3 can be made of a material that absorbs the specific electromagnetic wave X and generates heat. In this case, the above-described high dielectric constant substance can be mixed with the material constituting the whole or part of the mold 3. In this case, a layer containing a high dielectric constant substance can also be provided on all or part of the inner wall surface of the mold 3.

  When the molding die 3 contains a high dielectric power factor substance, the molding die 3 generates heat by absorbing at least a part of the specific electromagnetic wave X to be irradiated, and the specific thermoplastic resin 4 by heat conduction from the molding die 3. Is heated. Further, when the specific thermoplastic resin 4 has a property of generating heat by absorbing the specific electromagnetic wave X as the temperature rises, the specific thermoplastic resin 4 absorbs the specific electromagnetic wave X transmitted through the mold 3. By generating heat, the heating of the specific thermoplastic resin 4 can be further promoted.

  In the heat treatment apparatus 1, the mold 3 is disposed on the inner bottom surface 111 of the heat insulating container 11 with the heat insulating cover 12 of the heat insulating container 10 removed. Thereafter, the heat insulating lid 12 is disposed so as to close the opening 110 of the heat insulating container 11. Thereby, a closed space S in which the mold 3 is accommodated is formed inside the heat insulating accommodation box 10. In this state, as shown in FIG. 1, the electromagnetic wave irradiation means 20 irradiates the mold 3 with the specific electromagnetic wave X via the heat insulating housing box 10. At this time, the specific electromagnetic wave X is also applied to the heat generating material 15 provided in the heat insulating housing box 10. Thereby, the heat generating material 15 absorbs the specific electromagnetic wave X and generates heat. As a result, the specific thermoplastic resin 4 in the mold 3 is heated by absorbing the specific electromagnetic wave X itself, and at the same time, the radiant heat from the heat generating material 15 or the heat insulating container 10 heated by the heat generating material 15 is used. It is also heated by the gas present in the closed space S.

The temperature in the closed space S of the heat insulating storage box 10 is maintained at 100 to 500 ° C., for example.
Further, the irradiation condition of the specific electromagnetic wave X is appropriately set according to the type of the specific thermoplastic resin 4 and the like. For example, the output of the specific electromagnetic wave X by the electromagnetic wave irradiation means 20 can be set to 100 to 5000 W, and the irradiation time of the specific electromagnetic wave X to the mold 3 can be set to 1 to 120 minutes.

  The control means for controlling the irradiation operation of the specific electromagnetic wave X by the electromagnetic wave irradiation means 20 can measure the temperature of the mold 3 and control the temperature of the mold 3 to be a specific temperature. The control means can also control the irradiation of the specific electromagnetic wave X by the electromagnetic wave irradiation means 20 so that the specific heating rate of the mold 3 is maintained. When the mold 3 transmits the specific electromagnetic wave X, the mold 3 is heated by heat transfer from the specific thermoplastic resin 4 in the cavity 31.

The output range of the specific electromagnetic wave X by the electromagnetic wave irradiation means 20 is in the range of 0 to 5000 W, and the specific temperature increase rate for increasing the temperature of the mold 3 and the specific thermoplastic resin 4 is in the range of 1 to 100 ° C./min. be able to. Moreover, the temperature which heats and maintains the shaping | molding die 3 and the specific thermoplastic resin 4 can be in the range of 150-500 degreeC, and the irradiation time of the specific electromagnetic wave X can be in the range of 0.01-180 minutes.
The temperature of the mold 3 can be measured by a known method. As the thermometer for measuring the temperature of the mold 3, for example, a radiation thermometer, a thermocouple, a thermistor, or an optical fiber thermometer can be used.

  In the heat treatment apparatus 1 of the present embodiment, the specific thermoplastic resin 4 in the mold 3 is heated by absorbing the specific electromagnetic wave X by the electromagnetic wave irradiation means 20, and radiant heat from the heat generating material 15 or heat generating material. It is also heated by the gas present in the closed space S of the heat insulating container 10 heated by 15. In addition, since the heat generating material 15 is in contact with the bottom of the mold 3, the specific thermoplastic resin 4 in the mold 3 is also heated by the conduction heat from the heat generating material 15. Furthermore, when the specific thermoplastic resin 4 absorbs the specific electromagnetic wave X and self-heats, the specific thermoplastic resin 4 is also heated by absorbing the specific electromagnetic wave X. Therefore, according to the heat treatment apparatus 1 of the present embodiment, the specific thermoplastic resin 4 in the mold 3 can be uniformly heated throughout.

  As shown in FIG. 3, in the heat treatment apparatus 1, the heat generating material 15 disposed on the inner bottom surface 111 of the heat insulating container 11 can be formed in a frame shape having a placement hole 151 in which the molding die 3 is placed. . In this case, when the specific electromagnetic wave X is irradiated, the specific thermoplastic resin 4 in the mold 3 is heated by the heat conduction from the heat generating material 15, and the heat generating material 15 mainly receives the heat. It will be heated by radiant heat.

<Embodiment 2>
In this embodiment, another embodiment of the heat treatment apparatus 1 is shown, and a case where a heat treatment method and a resin molding method are performed using the heat treatment apparatus 1 will be described.
In this embodiment, the heat treatment apparatus 1 heats the specific thermoplastic resin 4 having a heat distortion temperature of 130 ° C. or higher. Here, the heat distortion temperature (deflection temperature under load) is one of the indexes for evaluating the heat resistance of the synthetic resin, and when the temperature is raised with the load applied to the synthetic resin, the synthetic resin This refers to the temperature at which the amount of deflection that occurs in is constant.
In addition, the specific thermoplastic resin 4 of the present embodiment has a property of not absorbing the specific electromagnetic wave X below a specific temperature, and a self-heating type that expresses the property of absorbing the specific electromagnetic wave X when the temperature exceeds a specific temperature. It is.

  In the heat treatment apparatus 1 of the present embodiment, as shown in FIGS. 4 and 5, sheet-like or plate-like heat generating materials 15 are arranged on the six inner wall surfaces of the heat-insulating storage box 10 having a cubic shape, so The mold 3 is placed on the heat generating material 15 on the inner bottom surface 111 of the storage box 10. In this embodiment, the six wall portions of the rectangular parallelepiped heat insulating container 10 are heated so that the temperature in the heat insulating container 10 is not locally biased, and the enclosed space S in the heat insulating container 10 is closed. Keep the temperature at high.

  The thickness of the bottom 32 in contact with the inner bottom surface 111 of the heat-insulating container 10 in the mold 3 is to increase the heat transfer from the heat generating material 15 to the specific thermoplastic resin 4 in the cavity 31 of the mold 3. The thickness is smaller than the thickness of the side portion 33 provided upright from the bottom portion 32. The thickness of the bottom portion 32 of the mold 3 is thin as long as there is no problem in strength, and the thickness of the side portion 33 of the mold 3 is thick in order to improve heat insulation. By reducing the thickness of the bottom 32 of the mold 3 as much as possible, heat conduction from the heat generating material 15 on the inner bottom surface 111 of the heat insulating housing box 10 to the specific thermoplastic resin 4 can be easily generated. The thickness of the side part 33 of the shaping | molding die 3 can be 2-100 times the thickness of the bottom part 32 of the shaping | molding die 3, for example.

  The bottom portion 32 of the mold 3 of this embodiment is formed of flexible sheet-like ceramics. By forming the bottom portion 32 in a sheet shape, heat conduction from the heat generating material 15 on the inner bottom surface 111 of the heat-insulating storage box 10 to the specific thermoplastic resin 4 can be more easily generated. Moreover, the durability of the sheet-like bottom part 32 can be improved by forming the sheet-like bottom part 32 from ceramics.

  Moreover, the thickness of the bottom part 32 becomes like this. Preferably it is 0.1-5 mm, More preferably, it is 0.5-3 mm, Most preferably, it is 1-2 mm. It is difficult to make the thickness of the bottom 32 less than 0.1 mm. Moreover, when the thickness of the bottom part 32 exceeds 5 mm, there exists a possibility that the effect which produces the heat conduction from the heat generating material 15 to the specific thermoplastic resin 4 may fade.

  The sheet-like ceramic as the bottom portion 32 is provided so that the specific thermoplastic resin 4 is not in direct contact with the heat generating material 15 and heat conduction from the heat generating material 15 to the specific thermoplastic resin 4 is good. This sheet-like ceramic can be made of a resin other than ceramics, rubber or the like as long as strength, thermal conductivity and heat resistance are secured.

  As shown in FIG. 4 to FIG. 6, the molding die 3 facilitates the arrangement of the specific thermoplastic resin 4 in the cavity 31 formed therein and the removal of the molded resin molded product. Moreover, it is divided into a plurality of mold parts 3A and 3B. The plurality of mold parts 3A and 3B can repeatedly mold a resin molded product. The mold 3 of this embodiment is divided into two mold parts 3A and 3B of the first mold part 3A and the second mold part 3B, and the two mold parts 3A and 3B are joined together. A cavity 31 is formed by 3A and 3B. The first mold part 3 </ b> A and the second mold part 3 </ b> B are obtained when the powdery, pelletized, or solid specific thermoplastic resin 4 disposed in the cavity 31 is melted to form a liquid specific thermoplastic resin 4. In addition, a relatively close slide is possible so that the volume of the cavity 31 can be reduced. In either of the two mold parts 3A and 3B, an ejector pin or the like for taking out a resin molded product after molding can be provided.

  The bottom portion 32 of the mold 3 is in contact with the heat generating material 15, while the side portion 33 and the ceiling portion 34 of the mold 3 are separated from the heat generating material 15. Then, heat is transferred from the heat generating material 15 on the inner bottom surface 111 of the heat insulating housing box 10 to the mold 3 by heat conduction, while the heat generating material 15 on the side surface 112 and the ceiling surface 113 of the heat insulating housing box 10 forms the mold 3. Heat is transmitted to the heat by thermal radiation (thermal radiation) through a gas such as air. Thereby, the specific thermoplastic resin 4 in the cavity 31 of the mold 3 is sequentially melted from a portion close to the bottom portion 32 of the mold 3 toward a portion close to the ceiling portion 34 of the mold 3. And by the structure by which such a specific thermoplastic resin 4 is heated toward the other side from the one side, the void which becomes a molding defect in the resin molded product molded by the specific thermoplastic resin 4 being melted ( Air bubbles and shrinkage nests are not formed.

  The heat generating material 15 can be a powder heat generating material formed by compressing and pressing particles containing a high dielectric power factor substance. Further, the heat generating material 15 may be a fired product of particles containing a high dielectric power factor substance. The cavity 31 of the molding die 3 can be formed by transferring a three-dimensional shape of the master model using a final product and a near net shape molded product as a shape close to the final product shape as a master model. it can. The mold 3 of this embodiment is a gypsum mold formed of gypsum, and the resin molded product molded in the cavity 31 of the mold 3 has a block shape. The gypsum mold has high heat insulating properties. Moreover, the heat insulating storage box 10 is also formed of gypsum. When forming the mold 3 with plaster, the bottom 32 of the mold 3 may be formed with plaster. When the molding die 3 is formed of a plaster mold, it is preferable to adjust the thickness of the bottom portion 32 to an appropriate thickness within a range that does not significantly impair the thermal conductivity from the heat generating material 15.

The mold 3 as a plaster mold can be produced as follows.
First, the master model is molded with RTV silicone rubber to produce a first transfer mold having a cavity in which the shape of the master model is transferred. Next, the first transfer mold is placed in a mold, and a second transfer mold having a cavity transferred by inverting the shape of the cavity and the outer surface of the first transfer mold is manufactured. Next, a gypsum slurry kneaded with water is poured into the cavity of the second transfer mold and solidified. Thereafter, the solidified gypsum is taken out from the cavity of the second transfer mold, and this gypsum becomes the mold 3 having the cavity 31 having the same shape as the master model.

  Also, when the mold 3 is manufactured using other castable ceramic materials, it can be manufactured by the same method as the plaster mold. Further, when the mold 3 is manufactured using a machinable ceramic material, the mold 3 can be manufactured by directly engraving the ceramic material. Furthermore, the shaping | molding die 3 can also be shape | molded directly by a three-dimensional modeling method.

(Heat treatment method and resin molding method)
Next, a heat treatment method and a resin molding method for forming a resin molded product using the heat treatment apparatus 1 of the present embodiment will be described.
In the resin molding method of the present embodiment, a resin molded product is molded in the mold 3 by performing an arrangement process, a housing process, a heating process, and a cooling process. The heat treatment method is a term used when focusing on the housing process and the heating process.

  First, in the arrangement step, as shown in FIG. 6, the pellet 41 of the specific thermoplastic resin 4 is arranged in the first mold part 3A of the mold 3, and the second mold part 3B is combined with the first mold part 3A. Then, the opening 310 of the first mold part 3A is closed by the second mold part 3B. And the shaping | molding die 3 by which the pellet 41 of the specific thermoplastic resin 4 is arrange | positioned in the cavity 31 formed of the 1st type | mold part 3A and the 2nd type | mold part 3B is formed.

  Next, in the housing step, as shown in FIG. 7, a molding die in which the specific thermoplastic resin 4 is disposed inside the closed space S of the heat insulating housing box 10 in which the heat generating material 15 is disposed on the inner bottom surface 111. 3 is accommodated in contact with the heat generating material 15. In other words, in the housing step, the mold 3 in which the pellets 41 of the specific thermoplastic resin 4 are arranged inside is disposed in the heat insulating container 11, and the heat insulating cover 11 is combined with the heat insulating container 11, The opening 110 of the heat insulating container 11 is closed by the heat insulating lid 12. At this time, the heat generating material 15 is provided on the inner wall surfaces of the heat insulating container 11 and the heat insulating lid 12. And the state by which the shaping | molding die 3 is arrange | positioned in the closed space S of the heat insulation storage box 10 is formed. 4, 6, and 7, the pellet 41 of the specific thermoplastic resin 4 is partially omitted.

  Next, in the heating step, as shown in FIG. 4, the electromagnetic wave irradiation means 20 causes the specific electromagnetic wave X including the wavelength region of 0.01 to 100 m to pass through the heat insulating housing box 10 to form the mold 3 and the heating material. 15, the heat generating material 15 is caused to generate heat, and the specific thermoplastic resin 4 in the mold 3 is heated using heat transfer from the heat generating material 15. In other words, in the heating step, the specific electromagnetic wave X is transmitted through the heat insulating housing box 10 and irradiated to the mold 3 and the heating material 15. In this embodiment, an electromagnetic wave irradiation means 20 that irradiates microwaves having a wavelength of 0.01 to 1 m is used. The specific electromagnetic wave X transmitted through the heat insulating housing box 10 is irradiated onto the heat generating material 15 and part of the heat generating material 15 is absorbed. The specific electromagnetic wave X is partially absorbed by the heat generating material 15 and attenuated, and then absorbed by the molding die 3 or further transmitted through the molding die 3 and absorbed by the specific thermoplastic resin 4 in the cavity 31. . Irradiation of the specific electromagnetic wave X by the electromagnetic wave irradiation means 20 continues until the entire specific thermoplastic resin 4 in the cavity 31 of the mold 3 is melted.

  At this time, the specific thermoplastic resin 4 hardly develops the property of absorbing the specific electromagnetic wave X in the initial stage of heating, and hardly generates heat even if it absorbs the specific electromagnetic wave X. On the other hand, the heat generating material 15 expresses the property of absorbing the specific electromagnetic wave X from the initial stage of heating, and generates heat by absorbing the specific electromagnetic wave X. And since the sheet-like bottom part 32 of the mold 3 is in contact with the heat generating material 15 on the inner bottom surface 111 of the heat-insulating storage box 10, the specific thermoplastic resin 4 in the cavity 31 of the mold 3 is Heat is transmitted from the heat generating material 15 on the inner bottom surface 111 of the heat insulating housing box 10 by heat conduction.

  Next, among the pellets 41 of all the specific thermoplastic resins 4, the temperature of the pellet 41 in any part of the lowermost portion that contacts the sheet-like bottom 32 reaches the melting point or the melting start temperature, and this pellet 41 Start melting first. When the melting of the pellets 41 is started, the pellets 41 adjacent to the pellets 41 are wetted by the molten pellets 41, and the number of pellets 41 to be melted increases.

  Further, when the pellet 41 in the entire lowermost portion that contacts the sheet-like bottom portion 32 is melted to form the molten layer 42, the pellet 41 adjacent to the upper side of the molten layer 42 and having already started softening is melted. It falls into the layer 42 and is integrated with the molten layer 42. Thereafter, the pellets 41 that melt from the lower side to the upper side sequentially increase, and the range in which the molten layer 42 is formed gradually increases from the lower side to the upper side. In other words, the pellets 41 in the mold 3 are sequentially transferred from a portion close to the inner bottom surface 111 to a portion far from the portion using the heat transfer from the heat generating material 15 arranged on the inner bottom surface 111 of the heat insulating housing box 10. It will melt. Moreover, in the whole pellet 41 of the specific thermoplastic resin 4, there may be a region where a portion that remains solid and a portion that has become liquid coexist.

  In addition, the specific thermoplastic resin 4 develops the property of absorbing the specific electromagnetic wave X and absorbs the specific electromagnetic wave X when heated at a specific temperature or higher in an unmelted solid state as the heating stage proceeds. And become self-heating. Thereby, when the solid pellet 41 is heated to a specific temperature or higher, the speed at which the solid pellet 41 changes from a solid to a liquid rapidly increases. For this reason, when the heating stage proceeds, the region of the molten layer 42 is rapidly expanded upward. As a result, the time for melting the specific thermoplastic resin 4 in the cavity 31 of the mold 3 can be shortened.

On the other hand, as the pellets 41 are melted, voids existing between the pellets 41, that is, air that is a generation source of voids, is expelled from the lower side to the upper side by the molten layer 42 that expands the region upward. Will be. When all the pellets 41 are changed to the molten layer 42, almost no air remains in the molten layer 42, and the air existing in the cavity 31 of the mold 3 is released above the molten layer 42.
Thereafter, when all the pellets 41 in the cavity 31 of the mold 3 are melted and the cavity 31 is filled with the molten layer 42, the irradiation of the specific electromagnetic wave X by the electromagnetic wave irradiation means 20 is stopped.

  Next, in the cooling step, the specific thermoplastic resin 4 in the cavity 31 of the mold 3 is cooled and solidified to obtain a resin molded product to which the inner surface shape of the mold 3 is transferred. When the specific thermoplastic resin 4 in the cavity 31 is solidified, the mold 3 can be taken out of the heat-insulating container 10 in order to facilitate cooling of the specific thermoplastic resin 4. The mold 3 and the specific thermoplastic resin 4 in the mold 3 can be cooled by air cooling or the like. In addition, the molding die 3 and the specific thermoplastic resin 4 can be gradually cooled while the molding die 3 is placed in the heat insulating container 10.

  When the specific thermoplastic resin 4 in the cavity 31 is solidified, a resin molded product is molded in the cavity 31. Then, the second mold part 3B is separated from the first mold part 3A of the mold 3, and the molded resin molded product is taken out from the opening 310 of the first mold part 3A. In the resin molded product thus molded, almost no voids are formed, and the quality of the resin molded product is good.

In addition, as shown in FIG. 8, the inside of the cavity 31 of the mold 3 can be decompressed by the vacuum pump 35, and the pellet 41 can be melted in the decompressed cavity 31. In this case, when the pressure in the cavity 31 is lower than the pressure outside the mold 3, a clamping force can be applied between the pair of mold parts 3 </ b> A and 3 </ b> B. When the pellet 41 is melted, the first mold part 3A and the second mold part 3B come close to each other, and a resin molded product of the specific thermoplastic resin 4 can be molded in the cavity 31 whose volume is reduced. it can.
In addition, the mold clamping force to the pair of mold parts 3A and 3B can be applied by applying a load from the second mold part 3B to the first mold part 3A, for example, besides using the difference in pressure. .

(Function and effect)
In the heat treatment method and the resin molding method of the present embodiment, by performing the heating step, the heat generating material 15 generates heat by absorbing the specific electromagnetic wave X, and the specific thermoplastic resin 4 in the mold 3 has a heat insulating property. Heating is performed using heat transfer from the heat generating material 15 on the inner bottom surface 111 of the containing box 10. Thereby, the specific thermoplastic resin 4 is easily heated, and the heating time can be shortened.

  Further, in order to melt the specific thermoplastic resin 4 in the mold 3, it is necessary to heat and maintain the specific thermoplastic resin 4 at a heating attainment temperature of 130 ° C. or higher. The ultimate heating temperature is appropriately determined according to the type of the specific thermoplastic resin 4 and the size, shape, etc. of the resin molded product molded from the specific thermoplastic resin.

  In the heat treatment method and the resin molding method of this embodiment, since the molding die 3 is accommodated in the closed space S of the heat insulating housing box 10, air or the like that exists around the molding die 3 in the closed space S is used. The gas is isolated from a gas such as air existing outside the heat insulating container 10. In the heating process, when the specific thermoplastic resin 4 in the mold 3 is melted by the specific electromagnetic wave X, the gas in the closed space S is heated by the mold 3 and the temperature of the gas in the closed space S is insulated. The temperature is higher than that of the gas outside the protective storage box 10.

  Thereby, it is possible to prevent the mold 3 from being cooled by the gas in the closed space S, and to maintain the mold 3 and the specific thermoplastic resin 4 in the mold 3 at a heating ultimate temperature of 130 ° C. or higher. It becomes easy. Therefore, the specific thermoplastic resin 4 in the mold 3 is hardly locally cooled, and the entire specific thermoplastic resin 4 can be heated as uniformly as possible. As a result, it is not necessary to continue irradiation with the specific electromagnetic wave X for a longer time than necessary, and it is possible to prevent the specific thermoplastic resin 4 from having a heat history such as burning due to being overheated.

  Further, in the heating process, the specific thermoplastic resin 4 in the mold 3 is heated and melted first from the portion close to the bottom portion 32 of the mold 3, and sequentially melted toward the portion far from the portion close to the bottom portion 32. To do. Thereby, the whole including the center part of the specific thermoplastic resin 4 can be melted, and an unmelted part can be prevented from remaining in the center part of the specific thermoplastic resin 4. Then, after the heating step, when the specific thermoplastic resin 4 is cooled, a resin molded product having as uniform a property as possible can be obtained.

  Therefore, according to the heat treatment method and the resin molding method of the present embodiment, the entire specific thermoplastic resin 4 having a heat distortion temperature of 130 ° C. or higher can be melted in a short time, and the resin molding has a uniform property as much as possible. Goods can be obtained.

  In this embodiment, the specific thermoplastic resin 4 in the cavity 31 of the mold 3 is heated by irradiation of the specific electromagnetic wave X by the electromagnetic wave irradiation means 20 in order to mold a resin molded product of the specific thermoplastic resin 4. The temperature is increased to 300 ° C. or higher. When heating the specific thermoplastic resin 4 to a high temperature of 300 ° C. or higher, as a result of research by the inventors, it has been found that it is effective to maintain the entire periphery of the mold 3 at a high temperature of 300 ° C. or higher. It was issued.

  In the conventional electromagnetic wave irradiation molding that does not use the heat insulating housing box 10, the surface of the mold 3 is not covered when the specific electromagnetic wave X by the electromagnetic wave irradiation means 20 is irradiated to the mold 3. Therefore, when the specific thermoplastic resin 4 in the mold 3 melts, the mold 3 is locally cooled by the air that contacts the mold 3, and the temperature distribution of the specific thermoplastic resin 4 in the mold 3 is reduced. Bias occurs. In particular, when the specific thermoplastic resin 4 that needs to be heated to a high temperature of 300 ° C. or higher is molded, a part of the specific thermoplastic resin 4 that is locally low in temperature is generated, and the resin molding is excellent in dimensional accuracy. It was difficult to obtain a product.

  In contrast, in the heat treatment method and the resin molding method of the present embodiment, the mold 3 is arranged in the heat insulating housing box 10 and the heat generating material 15 is provided on the inner wall surface of the heat insulating housing box 10. Yes. Thereby, when the specific thermoplastic resin 4 in the mold 3 is melted, the temperature of the air in the heat insulating container 10 is maintained at a high temperature of 300 ° C. or higher, and the entire periphery of the mold 3 is cooled by air. So that it won't be. As a result, a resin molded product of the specific thermoplastic resin 4 that has been difficult to mold by conventional electromagnetic wave irradiation molding can be molded with high dimensional accuracy.

  In particular, in the heat treatment method and the resin molding method of this embodiment, no void is formed in the resin molded product by melting the specific thermoplastic resin 4 in the mold 3 from one side to the other side. Can be. Thereby, the quality of the resin molded product can be improved.

(Wettability of specific thermoplastic resin 4)
As shown in FIG. 4, what is important in the phenomenon that the pellets 41 of the specific thermoplastic resin 4 in the mold 3 are melted is the molten layer of the pellets 41 that have become liquid on the surface of the solid pellets 41. 42 wettability. If the surface tension of the molten layer 42 is high and the wet contact angle of the molten layer 42 with respect to the surface of the solid pellet 41 is large, it can be said that the wettability is poor. In this case, it is considered that the compatibility between the molten layer 42 and the solid pellet 41 is poor, and voids are likely to occur. On the other hand, in this embodiment, since the surface tension of the molten layer 42 of the specific thermoplastic resin 4 is low and the solid pellet 41 and the molten layer 42 are the same type of material, the molten layer 42 for the solid pellet 41 is used. The wet contact angle becomes smaller. Therefore, it is possible to appropriately perform the molding in which the range in which the molten layer 42 is formed is expanded from the lower side to the upper side and the voids are released upward.

  In order to increase the molding speed in the heat treatment method and the resin molding method, it is conceivable to increase the molding temperature of the specific thermoplastic resin 4. When the solid pellet 41 is transformed into a liquid and becomes a molten layer 42, the solid pellet 41 absorbs heat in the molten layer 42. Thereby, even if the molding temperature of the specific thermoplastic resin 4 is set high, the molten layer 42 is prevented from being heated excessively, and the molding time of the specific thermoplastic resin 4 can be shortened.

(Problems of extrusion molding and injection molding)
Specified thermoplastic resins are heat resistant, mechanical properties, chemical resistance, flame resistance, chemical resistance, radiation resistance, solvents in fields such as aerospace, automobile, medical, semiconductor manufacturing, and high integrated circuit manufacturing. It was developed as a resin that meets various requirements such as low elution for As means for molding a specific thermoplastic resin, conventionally, use of extrusion molding or injection molding using an expensive mold has been studied.

  However, when a crystalline specific thermoplastic resin is molded by extrusion molding, a phase transformation of the specific thermoplastic resin from solid to liquid occurs rapidly, and the viscosity of the specific thermoplastic resin changes rapidly. Therefore, the intermediate plastic region between the solid and the liquid that can maintain the extruded shape is narrow, and it is difficult to perform good extrusion. On the other hand, when molding a specific thermoplastic resin by injection molding, when the specific thermoplastic resin solidifies from a liquid to a solid, a void (shrinkage nest) is generated at the center of the molded product of the specific thermoplastic resin. In particular, it is difficult to obtain a molded product having a large thickness. Further, in this case, since the molten specific thermoplastic resin has high fluidity, there is a problem that resin burrs (projections) are generated in the gaps of the mold.

(Conventional electromagnetic wave irradiation molding)
There is a problem in the case where the molding die 3Z is not arranged in the heat insulating housing box 10 and the pellet 41 of the specific thermoplastic resin 4 in the molding die 3Z is heated from all directions.
In this case, for example, as illustrated in FIG. 9, it is assumed that the mold 3 </ b> Z is not disposed in the heat insulating housing box 10 and the heat generating material 15 </ b> Z is provided on all outer surfaces of the mold 3 </ b> Z. . When the electromagnetic wave irradiation means 20 irradiates the molding die 3Z with the specific electromagnetic wave X, the whole pellet 41 in the molding die 3Z is heated from all directions in which the respective outer surfaces are located, and from the portions that are in contact with the respective outer surfaces. Melt first. Next, the molten layer 42 of the melted pellets 41 melts while the unmelted pellets 41 are involved, and simultaneously flows downward due to gravity. And although the pellet 41 located in the center part of the shaping | molding die 3Z is surrounded by the fusion | melting layer 42, it is not fully heated but melts | dissolves disorderly.

  Next, when the molding die 3Z is cooled after the entire pellet 41 is melted to form the molten layer 42, the void formed between the pellets 41 is involved to complete the solidification of the molten layer 42, and the resin A molded product is formed. In the resin molded product molded in this way, a void due to a void exists at the center. A resin molded product in which voids are present has poor quality and, for example, is inappropriate for use as a block for cutting.

As described above in the second embodiment, in the molding of the specific thermoplastic resin 4, by performing the electromagnetic wave irradiation molding using the heat insulating container 10 in which the heat generating material 15 of this embodiment is arranged, the quality is excellent. In addition, it has become possible to easily mold a resin molded product of the specific thermoplastic resin 4. Also in the second embodiment, other configurations are the same as those of the first embodiment, and the same effects as those of the first embodiment can be obtained.
In addition, this invention is not limited only to Embodiment 1, 2, and can take various structures in the limit which does not exceed the meaning of this invention.

According to the configuration shown in FIG. 1, a resin molded product made of PEEK (polyether ether ketone) resin was produced using the heat treatment apparatus 1 having the heat insulating container 10 and the electromagnetic wave irradiation means 20 having the following specifications.
[Insulation container 10]
Material: Alumina (thermal conductivity: 0.15 W / (m · K))
Dimensions of closed space S: 95 mm × 75 mm × 75 mm (internal volume: 534375 mm ³ )
The thickness of the side wall part (circumferential wall part) of the heat insulating container 11: 40 mm
The thickness of the bottom wall of the heat insulating container 11: 30 mm
Heat insulating lid 12 thickness: 30 mm
Heating material 15: A plate having a size of 60 mm × 60 mm × 10 mm, in which a slurry containing 1 part by mass of graphite as a high dielectric power substance and 37 parts by mass of silica fine particles is applied to a ceramic substrate.

[Electromagnetic wave irradiation means 20]
Wavelength (frequency) of specific electromagnetic wave X: 122 mm (2450 MHz, microwave)
Rated output: 600W

  In the present embodiment, the specific electromagnetic wave X by the electromagnetic wave irradiation means 20 is irradiated to the pellets of the PEEK resin in the molding die 3 arranged in the heat insulating container 10, and the dumbbell shown in FIG. It was confirmed whether or not a shaped resin molded product (length 90 mm, maximum width 13 mm, thickness 7 mm) could be molded satisfactorily.

  The mold 3 was a gypsum mold made of gypsum. The heat generating material 15 was disposed on the inner bottom surface 111 as the inner wall surface of the heat insulating housing box 10. The heating rate when heating the specific thermoplastic resin 4 in the mold 3 with the specific electromagnetic wave X was 4.5 ° C./min. Moreover, the specific thermoplastic resin 4 was heated over 84 minutes until it became 380 degreeC as target heating temperature higher than the heat deformation temperature. In addition, the specific thermoplastic resin 4 was maintained at a temperature of 380 ° C. for 60 minutes and gradually cooled, and then the molded resin molded product was taken out.

  When the obtained resin molded product was cut and the cross section was observed, this resin molded product had no voids inside, and no PEEK resin pellets remained. And it turned out that the whole resin molded product has shown the uniform property, and is excellent in quality. Moreover, the balance of the tensile strength in the three-dimensional arbitrary direction of the resin molded product was also favorable.

  From the results of this example, the PEEK resin, which is the specific thermoplastic resin 4, uses the molding die 3 arranged in the heat insulating container 10 and the specific electromagnetic wave X including a wavelength region of 0.01 to 100 m. It has been found that it is suitable for molding.

DESCRIPTION OF SYMBOLS 1 Heat processing apparatus 10 Heat insulation container 15 Heat generating material 20 Electromagnetic wave irradiation means 3 Mold 31 Cavity 311 Inner bottom face 4 Specific thermoplastic resin S Closed space X Specific electromagnetic wave

Claims (9)

A heat treatment method for heating a thermoplastic resin having a heat distortion temperature of 130 ° C. or more, which is disposed in a mold made of a heat-resistant inorganic material by a specific electromagnetic wave including a wavelength region of 0.01 to 100 m,
A housing step of housing the molding die in which the thermoplastic resin is disposed in a closed space of a heat insulating housing box in which the heat generating material is disposed on the inner bottom surface, in a state in contact with the heat generating material;
The specific electromagnetic wave is transmitted through the heat insulating housing box to irradiate the mold and the heat generating material to heat the heat generating material, and heat transfer from the heat generating material is used to heat the heat in the mold. And a heating step of heating the plastic resin.   The heat treatment method according to claim 1, wherein the heat-resistant inorganic material forming the mold is at least one material selected from the group consisting of ceramics, gypsum, glass, cork, mullite, zirconia, and cement.   3. The heat treatment method according to claim 1, wherein a thickness of a bottom portion of the mold that contacts the inner bottom surface of the heat insulating container is smaller than a thickness of a side portion of the mold.   The heat treatment method according to claim 3, wherein the bottom of the mold is formed of a flexible sheet that closes an opening in a side of the mold.   The heat treatment method according to claim 4, wherein the sheet has a thickness of 0.1 to 5 mm.   The heat treatment method according to claim 3, wherein a bottom portion of the mold is formed of ceramics.   The heating element contains at least one substance selected from the group consisting of graphite, silicon carbide, ferrite, barium titanate, carbon black, graphite, and manganese dioxide according to any one of claims 1 to 6. The heat processing method as described.   8. The heat treatment method according to claim 1, wherein, in the heating step, the thermoplastic resin in the mold is sequentially melted from a portion close to the inner bottom surface toward a portion far from the inner bottom surface. Using the heat treatment method according to any one of claims 1 to 8,
After performing the said heating process, the resin molding method which performs the cooling process which cools and solidifies the said thermoplastic resin in the said mold, and obtains the resin molded product to which the inner surface shape of the said mold was transcribe | transferred.

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