JP2005111750A - Method and apparatus for molding resin component - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for molding a resin component using at least two resins different in viscosity comprising a high viscosity resin compounded with nano-order fine particles as a filler and a low viscosity resin not compounded with the filler, and to provide a resin part molding apparatus using it. <P>SOLUTION: First, the transparent low viscosity resin containing no filler is injected in a mold and a slide core is succeedingly allowed to retreat to form a cavity having the frame structure part of a target molded product. The transparent high viscosity resin containing silica fine particles as the filler is injected in the cavity to be compression-molded before cooled and solidified. The obtained molded product is improved in transparency, has no image strain, is good in optical characteristics and improved in mechanical characteristics without damaging strength or rigidity. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a novel molding method for transparent resin parts that can expand the field of view and contribute to improvement of safety, such as window glass for automobiles and front pillars, and resin parts that can be used in the molding method. The present invention relates to a molding apparatus. More specifically, the present invention relates to a method for molding a transparent resin molded product in which a resin in which nano-order silica fine particles are blended as a filler into a transparent resin such as a polycarbonate resin or an acrylic resin is used as a reinforcing frame structure. is there. In the molding method of the present invention, a low-viscosity transparent resin is first injected into a mold, and then a gap serving as a cavity of the frame structure portion is created by a core back. And it consists of the process of injecting highly viscous transparent resin into this cavity, and compression-molding before this resin cools and solidifies.

  For the purpose of improving safety, it is preferable to widen the field of view of an automobile front window and eliminate blind spots. Therefore, various devices have been conventionally devised. For example, there are a method of improving the field of view by attaching a small window to the pillar, and a method of improving the field of view by making the pillar a steel frame structure.

  In addition, as one method of reducing the weight by using inorganic glass as a transparent resin, there is a composite method of inorganic glass and transparent resin. “Plate-shaped composite and its manufacturing method” by Komatsu Ltd. (Japanese Patent Laid-Open No. 9-286039) (Patent Publication) discloses a method of mounting an inorganic glass plate in a mold, injecting molten resin, and pressurizing. This is simply a method of forming different materials into two layers, and has the feature that the surface is hardly scratched, but the degree of freedom of shape is limited by the workability of inorganic glass. Therefore, this method has a disadvantage that the degree of freedom of the original resin molding is greatly reduced.

  In the method of Yamashita Electric's “two-color molding method using a different material resin” (Japanese Patent Laid-Open No. 7-329111), a transparent resin is molded in the light transmitting portion and a colored resin is molded in the light shielding portion. Mainly, the effect of identifying characters and figures appears. Therefore, what is made in this method is only partial molding with different colors, and there is no effect of reducing the weight by improving the strength and rigidity, and no effect of expanding the field of view.

JP-A-9-286039 Japanese Unexamined Patent Publication No. 7-329111

  The present inventors have so far conducted various studies on transparent resins containing nano-order fine particles as fillers. Considering molding such as automotive parts as a transparent resin material containing such nano-order fine particles, the conventional two-color molding method of different materials has high melt viscosity and lacks fluidity. In addition, there is a risk of shape defects due to short shots.

  In addition, the transparent resin containing nano-order fine particles as the filler and the transparent resin without filler are different in molding shrinkage after molding, so the conventional two-color molding method of different materials causes optical distortion. When used in windshields and front pillars for automobiles, there is a risk of poor visibility due to poor transparency or image distortion.

  In addition, in the conventional two-color molding method of different materials, the interfacial fusion between the transparent resin containing nano-order fine particles as the filler and the transparent resin without the filler is not sufficient, so the strength improvement by the frame structure is insufficient. There is a fear.

  As described above, in the conventional two-color molding method using different materials, a transparent resin containing nano-order fine particles as a filler has a high melt viscosity and lack of fluidity, which may cause a shape defect due to a short shot. . To solve this, inject the molten resin into the cavity obtained by retreating the slide core, then compress and mold the molten resin while moving the slide core forward, such as bubbles, welds, molding sinks, etc. It becomes possible to eliminate shape defects.

  In addition, transparent resin containing nano-order fine particles as filler and transparent resin without filler differ in molding shrinkage, so the conventional two-color molding method of different materials has optical distortion at the interface of different materials. May occur, resulting in poor transparency and image distortion. To solve this problem, molten resin is injected into the cavity obtained by retracting the slide core, and then the molten resin is compressed while the slide core is advanced, and the transparent resin without filler shrinks due to molding shrinkage. By adopting a process of forming so as to replenish the amount, the occurrence of optical distortion such as the interface of different materials can be prevented, and it becomes possible to eliminate the poor transparency and image distortion.

  Further, in the conventional two-color molding method of different materials, the fusion of the interface between the transparent resin containing nano-order fine particles as a filler and the transparent resin without the filler is not sufficient, so the strength and bending rigidity due to the frame structure There is a risk that the improvement in torsional rigidity will be insufficient. To solve this problem, the molten resin is injected into the cavity obtained by retracting the slide core, and then the molten resin is compressed while the slide core is advanced. By adopting the process of molding so as to replenish the shrinkage, it is possible to prevent poor fusion at the interface of dissimilar materials and to prevent a decrease in strength, bending rigidity and torsional rigidity. It becomes possible.

  Therefore, the present invention provides a method for molding a resin component using a high-viscosity resin containing nano-order fine particles as a filler and a low-viscosity resin without a filler. More specifically, in the method for molding a resin component according to the present invention, a low-viscosity resin is injected from a nozzle and filled into a cavity for the low-viscosity resin, the filled low-viscosity resin is cooled and solidified, and then slided The core is retracted to create a gap between the high-viscosity resin cavities, the high-viscosity resin is injected from the nozzle and filled into the high-viscosity resin cavities, and then the slide core is advanced. The high-viscosity resin in a molten state is pressurized to fuse the low-viscosity resin that has been cooled and solidified with the high-viscosity resin in a molten state, and the high-viscosity resin is cooled and solidified, and then released.

  Furthermore, this invention provides the apparatus for shape | molding a resin component using said method. More specifically, the molding apparatus for resin parts of the present invention is used for molding at least two types of resins having different viscosities, and includes a low-viscosity resin sprue for introducing a low-viscosity resin into the molding apparatus, Low-viscosity resin molding comprising a low-viscosity resin cavity for molding the low-viscosity resin, and a low-viscosity resin hot runner connected to the low-viscosity resin sprue to guide the low-viscosity resin to the low-viscosity resin cavity And a high-viscosity resin sprue for introducing the high-viscosity resin into the molding apparatus, a high-viscosity resin cavity for molding the high-viscosity resin, and the high-viscosity resin sprue connected to the high-viscosity resin sprue High-viscosity resin hot runner leading to the cavity, a slide core for changing the volume of the high-viscosity resin cavity, and reciprocating by hydraulic pressure connected to the slide core The in which and a high-viscosity resin molded portion comprising a plunger for varying the volume of the high viscosity resin cavities by performing.

  According to the present invention, first, a transparent low-viscosity resin without a filler is injected into a mold, and then a slide core is retracted to create a cavity of a frame structure portion of a target molded product, where silica A method for molding a transparent resin part, which comprises injecting a transparent high-viscosity resin with fine particles as a filler, and compression-molding the high-viscosity resin before cooling and solidifying, and a transparent resin part for use in this method A molding apparatus was provided. The molded product obtained by this molding method had good transparency, no image distortion, good optical properties, good strength and rigidity, and good mechanical properties.

  Details of the present invention will be described below. Currently, various resins such as an acrylic resin, a polycarbonate resin, and a polystyrene resin can be cited as transparent resins that have been put into practical use. As the transparent resin used in the present invention, polycarbonate resin and acrylic resin are effective from the viewpoint of strength, elastic modulus, impact characteristics, etc., but are not limited thereto.

  Silica fine particles are effective as a filler for reinforcing these resins. However, the present invention is not limited thereto, and other inorganic fine particles can be appropriately used as a filler. In the following Examples, the silica surface was substituted with a hydrophobic group such as a methyl group, and a filler capable of being uniformly dispersed in the resin was used as a filler. Silica fine particles (Snowtex MEK-ST: manufactured by Nissan Chemical Co., Ltd.) have a particle size of 10 to 20 nm. When dispersed in a resin, the dispersion is less than the wavelength of 380 nm, which is visible light. It is. Thus, fillers having an average particle size of 380 nm or less are suitable for the purposes of the present invention, but are not limited within that range. Further, even if the fine particles are aggregated to form secondary particles and dispersed, the resin containing silica fine particles is transparent when the dispersion is not more than a wavelength of visible light of 380 nm. However, it is desirable to disperse at 200 nm or less, in which case the transparency is particularly good.

  As described above, the silica fine particles blended with the polycarbonate resin or the acrylic resin as the filler can be used as the high viscosity resin, while the polycarbonate resin or the acrylic resin without the filler can be used as the low viscosity resin. The amount of silica fine particles is desirably 20 wt% to 30 wt%, but is not limited to that range.

  Next, one example of the obtained molded resin part is shown in FIG. In the following description, numerals or alphabets in parentheses indicate reference numerals in the drawings. In FIG. 1, FIG. 1A is a low-viscosity resin that is a polycarbonate resin or acrylic resin that does not contain a filler, and FIG. 1B is a high-viscosity resin that is a composite polycarbonate resin or silica resin that contains silica fine particles. is there. This is to ensure strength and rigidity as a structural body using a resin having a reinforcing effect as a frame structure, and to ensure visibility by light transmission. In addition, the degree of freedom of the curved surface shape is sufficient, and designs that match the times are possible.

  Next, the molding method will be described with reference to FIGS. First, a method for molding a polycarbonate resin or an acrylic resin, which is a low viscosity resin, is shown in FIG. The low-viscosity resin (a) is injected from the low-viscosity resin nozzle (4), passes through the low-viscosity resin sprue (12), and passes through the low-viscosity resin hot runner (3). The molten resin is filled into the low-viscosity resin cavity (1-a) from 2), and the low-viscosity resin (a) is cooled and solidified to obtain the shape A (A).

  Next, the process of retreating the slide core and injecting the highly viscous resin is shown in FIG. That is, in order to mold the silica fine particle-containing polycarbonate resin or silica fine particle-containing acrylic resin, which is a high-viscosity resin (b), the plunger (10) is actuated with the hydraulic oil in the working hydraulic chamber (11), and the ride core (1). , The gap to be the cavity (1-b) for the high viscosity resin is created, the resin is injected from the nozzle (5) for the high viscosity resin, and the hot runner for the high viscosity resin from the sprue (13) for the high viscosity resin Passing (6), the molten resin fills the cavity (1-b) for the high viscosity resin from the pinpoint gate (7) for the high viscosity resin.

  Furthermore, the process of advancing the slide core to compression-mold the low viscosity resin is shown in FIG. In this process, before cooling and solidifying to obtain the shape B (B), the plunger (10) is operated with the hydraulic oil in the hydraulic hydraulic chamber (11), the slide core (1) is advanced and pressurized, The highly viscous resin (b) is cooled and solidified to obtain the shape B (B). The method of the present invention makes it possible to obtain a molded article having good transparency, no image distortion, and good optical properties.

  In order to further improve the accuracy of molding, it is possible to control the pressure with a piezoelectric element when performing compression molding, as shown in FIG. To mold the highly viscous resin, the hydraulic oil pressure in the hydraulic chamber (11) is measured with the hydraulic pressure measurement piezoelectric element (9) and the hydraulic pressure display voltmeter (P2), and the plunger (10) is operated. Then, the slide core (1) is retracted to create a gap that becomes the high-viscosity resin cavity B (1-b). Resin is injected from the high-viscosity resin nozzle (5), passes through the high-viscosity resin sprue (13), passes through the high-viscosity resin hot runner (6), and melts from the high-viscosity resin pinpoint gate (7). However, before filling the cavity (1-b) for high-viscosity resin and cooling and solidifying to obtain the shape B (B), the pressure of the hydraulic oil in the hydraulic pressure chamber (11) is changed to the hydraulic pressure measurement piezoelectric element (9). And measure with the voltmeter (P2) for oil pressure display. Further, the plunger (10) is actuated by the hydraulic oil in the hydraulic chamber (11) to advance the slide core (1), and the pressure of the molten high-viscosity resin is applied to the resin pressure piezoelectric element (8) and the resin. It measures with the voltmeter for pressure display (P1), pressurizes high-viscosity resin with a suitable pressure, it cools and solidifies, and shape B (B) is obtained.

  By this construction method, it is possible to obtain a molded article having further excellent transparency, extremely small image distortion, and very good optical characteristics. FIG. 6 shows the procedure of this construction method in a flow sheet. This molded resin part can be used for automobile windshields, front pillars, etc., improving visibility, reducing weight, and increasing design flexibility. Two types of molded product shapes A and B produced in the following examples are shown in FIGS. 7 and 8, respectively. FIG. 9 shows a state where the resin molded part of the present invention is used for a window glass and a back door glass of a car, and FIG. 10 shows a state where it is used for a transparent pillar of a car.

Hereinafter, examples of the present invention will be described in detail. The present invention is not limited thereby.
In Examples, Iupilon S-2000 (manufactured by Mitsubishi Engineering Plastics) was used as a polycarbonate resin (abbreviated as PC) which is a low-viscosity resin. As a highly viscous resin, 20 weight (wt)% or 30 (wt)% of silica fine particles were blended with polycarbonate resin. Hereinafter, a polycarbonate resin containing 20% by weight (wt)% of silica fine particles is referred to as silica 20% PC, and a polycarbonate resin containing 30% by weight (wt) of silica fine particles is referred to as silica 30% PC. In this example, Snowtex MEK-ST (manufactured by Nissan Chemical Co., Ltd.) was used as the silica fine particles.

(Example 1)
As the molding material, PC was used as a low-viscosity resin and 20% PC was used as a high-viscosity resin. The molded product shape A was a shape in which two triangular frames were combined (width 50 mm, length 110 mm, thickness 3 mm). The appearance of the molded product shape A is shown in FIG. For the purpose of reinforcing the molded product, 20% PC of silica was used in the frame structure (FIG. 7, b). As the molding machine, a two-color molding machine (clamping force 137 tons: made by Nissei Plastics) was used. The molding conditions were a cylinder temperature of 265 to 270 ° C. for PC and a cylinder temperature of 280 to 290 ° C. for 20% silica. The mold temperature was 110-120 ° C.

  Details of the molding die are as described above. That is, the slide core (1) was moved backward to provide a high-viscosity resin cavity (1-b) as a part for molding the silica-blended PC, and the silica-blended PC was injection molded therein. The resin temperature was measured, and the slide core was advanced and pressurized before cooling and solidification, and then solidified by cooling and release. The outline of the mold is as shown in FIGS. FIG. 2 shows the molding of PC, which is a low-viscosity resin, and FIGS. 3 and 4 show the molding of 20% PC of silica, which is a high-viscosity resin. The resulting molded article had good transparency in appearance, no molding distortion or image distortion, and the bending deflection was reduced by 20% compared to PC alone. One side was fixed by bending bending of the cantilever, and a 0.5 kg load was applied to the end, and the rigidity of the molded product was evaluated. The evaluation results are shown in Table 11.

(Example 2)
As the molding material, PC was used as the low-viscosity resin, and 30% silica was used as the high-viscosity resin. The molded product shape A was a shape in which two triangular frames were combined (width 50 mm, length 110 mm, thickness 3 mm). The appearance of the molded product shape A is shown in FIG. For the purpose of reinforcing the molded product, 30% PC of silica was used in the frame structure (FIG. 7, b). As the molding machine, a two-color molding machine (clamping force 137 tons: made by Nissei Plastics) was used. The molding conditions were a cylinder temperature of 265 to 270 ° C for PC and a cylinder temperature of 285 to 295 ° C for 30% silica PC. The mold temperature was 110-120 ° C.

  Details of the molding die are as described above. That is, the slide core (1) was moved backward to provide a high-viscosity resin cavity (1-b) as a part for molding the silica-blended PC, and the silica-blended PC was injection molded therein. The resin temperature was measured, and the slide core was advanced and pressurized before cooling and solidification, and then solidified by cooling and release. The outline of the mold is as shown in FIGS. The molding of PC, which is a low viscosity resin, is shown in FIG. 2, and the molding of 30% silica, which is a high viscosity resin, is shown in FIGS. The obtained molded article was excellent in transparency in appearance, free from molding distortion and image distortion, and the bending deflection was reduced by 30% compared to PC alone. One side was fixed by bending bending of the cantilever, and a 0.5 kg load was applied to the end, and the rigidity of the molded product was evaluated. The evaluation results are shown in Table 1.

(Example 3)
As the molding material, PC was used as the low-viscosity resin and 20% PC was used as the high-viscosity resin. The molded product shape B was formed by combining four triangular frames (width 50 mm, length 160 mm, thickness 3 mm). The appearance of the molded product is shown in FIG. For the purpose of reinforcing the molded product, 20% PC of silica was used in the frame structure (FIG. 8, b). As the molding machine, a two-color molding machine (clamping force 137 tons: made by Nissei Plastics) was used. The molding conditions were such that the cylinder temperature was 265 to 270 ° C for PC, and the cylinder temperature was 280 to 290 ° C for 20% silica. The mold temperature was 110-120 ° C.

  Details of the molding die are as described above. That is, the slide core (1) was moved backward to provide a high-viscosity resin cavity (1-b) that was a part for molding the silica-blended PC, and the silica-blended PC was injection molded therein. The resin temperature was measured, and the slide core was advanced and pressurized before cooling and solidification, and then solidified by cooling and release. The outline of the mold is as shown in FIGS. FIG. 2 shows the molding of PC, which is a low-viscosity resin, and FIGS. 3 and 4 show the molding of 20% PC of silica, which is a high-viscosity resin. The resulting molded article had good transparency in appearance, no molding distortion or image distortion, and the bending deflection was reduced by 20% compared to PC alone. One side was fixed by bending bending of the cantilever, and a 0.5 kg load was applied to the end, and the rigidity of the molded product was evaluated. The evaluation results are shown in Table 1.

Example 4
As the molding material, PC was used for the low-viscosity resin and 30% PC for silica was used for the high-viscosity resin. The molded product shape B was formed by combining four triangular frames (width 50 mm, length 160 mm, thickness 3 mm). The appearance of the molded product is shown in FIG. Silica 30% PC was used for the frame structure portion (FIG. 8, b) for the purpose of reinforcing the molded product. As the molding machine, a two-color molding machine (clamping force 137 tons: made by Nissei Plastics) was used. The molding conditions were a cylinder temperature of 265 to 270 ° C for PC and a cylinder temperature of 285 to 295 ° C for 30% silica PC. The mold temperature was 110-120 ° C.

  Details of the molding die are as described above. That is, the slide core (1) was moved backward to provide a high-viscosity resin cavity (1-b) that was a part for molding the silica-blended PC, and the silica-blended PC was injection molded therein. The resin temperature was measured, and the slide core was advanced and pressurized before cooling and solidification, and then solidified by cooling and release. The outline of the mold is as shown in FIGS. The molding of PC, which is a low viscosity resin, is shown in FIG. 2, and the molding of 30% silica, which is a high viscosity resin, is shown in FIGS. The obtained molded article was excellent in transparency in appearance, free from molding distortion and image distortion, and the bending deflection was reduced by 30% compared to PC alone. One side was fixed by bending bending of the cantilever, and a 0.5 kg load was applied to the end, and the rigidity of the molded product was evaluated. The evaluation results are shown in Table 1.

(Example 5)
As the molding material, PC was used for the low-viscosity resin and 30% PC for silica was used for the high-viscosity resin. The molded product shape B was formed by combining four triangular frames (width 50 mm, length 160 mm, thickness 3 mm). The appearance of the molded product is shown in FIG. Silica 30% PC was used for the frame structure portion (FIG. 8, b) for the purpose of reinforcing the molded product. As the molding machine, a two-color molding machine (clamping force 137 tons: made by Nissei Plastics) was used. The molding conditions were a cylinder temperature of 265 to 270 ° C for PC and a cylinder temperature of 285 to 295 ° C for 30% silica PC. The mold temperature was 110-120 ° C.

  Details of the molding die are as described above. That is, the slide core (1) was moved backward to provide a high-viscosity resin cavity (1-b) that was a part for molding the silica-blended PC, and the silica-blended PC was injection molded therein. The resin temperature was measured, and the slide core was advanced and pressurized before cooling and solidification, and then solidified by cooling and release. The applied pressure was measured by the piezoelectric element for measuring resin pressure (8) and the piezoelectric element for measuring hydraulic pressure (9) to obtain an appropriate pressure. Thereafter, the molded product was cooled and solidified and released. The outline of the mold is as shown in FIGS. The molding of PC, which is a low viscosity resin, is shown in FIG. 2, and the molding of 30% silica, which is a high viscosity resin, is shown in FIGS.

  Compared to Example 4, the obtained molded article has particularly good appearance transparency, molding distortion and image distortion are particularly small compared to Example 4, and bending deflection is reduced by 32% compared to PC alone. It was. One side was fixed by bending bending of the cantilever, and a 0.5 kg load was applied to the end, and the rigidity of the molded product was evaluated. The evaluation results are shown in Table 1.

(Example 6)
As a molding material, an acrylic resin (Acrypet VH: manufactured by Mitsubishi Rayon) was used as a low viscosity resin, and an acrylic resin containing 30% silica fine particles was used as a high viscosity resin. As the silica fine particles, Snowtex MEK-ST (manufactured by Nissan Chemical Industries) was used. The molded product shape B was formed by combining four triangular frames (width 50 mm, length 160 mm, thickness 3 mm). The appearance of the molded product is shown in FIG. For the purpose of reinforcing the molded product, an acrylic resin containing 30% silica fine particles was used in the frame structure (FIG. 8, b). As the molding machine, a two-color molding machine (clamping force 137 tons: made by Nissei Plastics) was used. The molding conditions were such that the cylinder temperature was 210 to 260 ° C. for acrylic resin, and the cylinder temperature was 230 to 285 ° C. for acrylic resin containing 30% silica fine particles. The mold temperature was 50 to 90 ° C.

  Details of the molding die are as described above. That is, the slide core (1) is moved backward to provide a high-viscosity resin cavity (1-b) for molding an acrylic resin containing 30% silica fine particles, and the acrylic resin containing 30% silica fine particles is injection molded here. did. The resin temperature was measured, and the slide core was advanced and pressurized before cooling and solidification, and then solidified by cooling and release. The outline of the mold is as shown in FIGS. In addition, the shaping | molding of the acrylic resin which is a low-viscosity resin is shown in FIG. 2, and the shaping | molding of 30% of silica fine particle mixing acrylics which is a high-viscosity resin is shown in FIG. 3 and FIG. The obtained molded article had good appearance and transparency, had no molding distortion and image distortion, and the bending deflection was reduced by 30% compared to acrylic alone. One side was fixed by bending bending of the cantilever, and a 0.5 kg load was applied to the end, and the rigidity of the molded product was evaluated. Table 1 shows the evaluation results.

(Comparative Example 1)
PC (Iupilon S-2000: Mitsubishi Engineering Plastics) was used as a molding material. The molded product shape A was a shape in which two triangular frames were combined (width 50 mm, length 110 mm, thickness 3 mm). The appearance of the molded product is shown in FIG. PC (Iupilon S-2000) was used for the part of the frame structure (FIG. 7, b) for the purpose of reinforcing the molded product. As the molding machine, a two-color molding machine (clamping force 137 tons: made by Nissei Plastics) was used. The molding conditions were a cylinder temperature of 265 to 270 ° C and a mold temperature of 110 to 120 ° C. The same mold as in Example 1 was used as the molding die. The obtained molded product was excellent in transparency in appearance, had no molding distortion, and the bending deflection was 20% larger than that in Example 1. One side was fixed by bending bending of the cantilever, and a 0.5 kg load was applied to the end, and the rigidity of the molded product was evaluated. The evaluation results are shown in Table 1.

(Comparative Example 2)
PC (Iupilon S-2000: Mitsubishi Engineering Plastics) was used as a molding material. The molded product shape B was formed by combining four triangular frames (width 50 mm, length 160 m, thickness 3 mm). The appearance of the molded product is shown in FIG. PC (Iupilon S-2000) was used for the part of the frame structure (FIG. 8, b) for the purpose of reinforcing the molded product. As the molding machine, a two-color molding machine (clamping force 137 tons: made by Nissei Plastics) was used. The molding conditions were a cylinder temperature of 265 to 270 ° C and a mold temperature of 110 to 120 ° C. The same mold as in Example 3 was used as the molding die. The obtained molded article was excellent in transparency in appearance, free from molding distortion and image distortion, and the bending deflection was 20% larger than that in Example 3. One side was fixed by bending bending of the cantilever, and a 0.5 kg load was applied to the end, and the rigidity of the molded product was evaluated. The evaluation results are shown in Table 1.

(Comparative Example 3)
As a molding material, an acrylic resin (Acrypet VH: manufactured by Mitsubishi Rayon) was used. The shape of the molded product was a basic element B (width 50 mm, length 160 mm, thickness 3 mm) in which four triangles were combined. The appearance of the molded product is shown in FIG. An acrylic resin (Acrypet VH: manufactured by Mitsubishi Rayon) was used for the frame structure (FIG. 8, b) for the purpose of reinforcing the molded product. As the molding machine, a two-color molding machine (clamping force 137 tons: made by Nissei Plastics) was used. The molding conditions were a cylinder temperature of 210 to 260 ° C and a mold temperature of 50 to 90 ° C. The same mold as in Example 6 was used as the molding die. The obtained molded product had good transparency in appearance, no molding distortion or image distortion, and the bending deflection was 30% larger than that in Example 6. One side was fixed by bending bending of the cantilever, and a 0.5 kg load was applied to the end, and the rigidity of the molded product was evaluated. The evaluation results are shown in Table 1.

  The present invention has been described in detail according to the embodiments of the present invention. However, the present invention is not limited to the above contents, and all modifications and changes can be made without departing from the scope of the present invention. Is possible.

  The transparent resin part molded by the method of the present invention has characteristics that transparency is good, image distortion is extremely small, and optical characteristics are extremely good. Such characteristics are suitable for automobile parts, and by using transparent resin parts molded by the method of the present invention for automobile window glass, front pillars, etc., the driver's field of view is expanded and safety is improved. It is possible to contribute to improvement.

FIG. 1 is a view showing an appearance of a molded resin part of the present invention. FIG. 2 is a diagram illustrating a molding process of a low viscosity resin. FIG. 3 is a diagram showing a process of retracting the slide core and injecting a highly viscous resin. FIG. 4 is a diagram illustrating a process of advancing the slide core and compressing a highly viscous resin. FIG. 5 is a diagram showing a process of detecting and controlling pressure with a piezoelectric element when a slide core is advanced to compress and mold a high viscosity resin. FIG. 6 is a flow sheet showing the method for molding a transparent resin part of the present invention. FIG. 7 is a diagram showing a molded product shape A produced in the present invention. FIG. 8 is a diagram showing a molded product shape B produced in the present invention. FIG. 9 is a view showing a state where the resin molded part of the present invention is used for a window glass and a back door glass of a car. FIG. 10 is a view showing a state where the resin molded part of the present invention is used for a transparent pillar of a car.

Explanation of symbols

1 Slide core 2 Pinpoint gate for low viscosity resin 3 Hot runner for low viscosity resin 4 Nozzle for low viscosity resin 5 Nozzle for high viscosity resin 6 Hot runner for high viscosity resin 7 Pinpoint gate for high viscosity resin 8 For resin pressure measurement Piezoelectric element 9 Hydraulic pressure measuring piezoelectric element 10 Plunger 11 Operating hydraulic chamber 12 Low-viscosity resin sprue 13 High-viscosity resin sprue A Shape A
B Shape B
a Low viscosity resin a
b High viscosity resin b
1-a Low viscosity resin cavity 1-b High viscosity resin cavity P1 Resin pressure display voltmeter P2 Hydraulic pressure display voltmeter

Claims (9)

The low-viscosity resin is injected from the nozzle and filled into the low-viscosity resin cavity, the filled low-viscosity resin is cooled and solidified, and then the slide core is retracted to create a gap of the high-viscosity resin cavity. The high-viscosity resin is injected from the nozzle and filled into the cavity for the high-viscosity resin, and then the slide core is advanced to pressurize the high-viscosity resin in a molten state to be cooled and solidified. A method for molding a resin component, comprising: fusing the low-viscosity resin and the high-viscosity resin in a molten state, releasing the mold after cooling and solidifying the high-viscosity resin. When the slide core is advanced, a preset pressure is measured while measuring the molten resin pressure in the high-viscosity resin cavity and the hydraulic pressure to advance the slide core with the resin pressure measuring piezoelectric element and the hydraulic pressure measuring pressure element. 2. The method of molding a resin part according to claim 1, further comprising pressurizing the molten resin in the cavity for the high viscosity resin within a range. The method for molding a resin part according to claim 1, wherein the low-viscosity resin is a polycarbonate resin or an acrylic resin. 3. The method for molding a resin part according to claim 1, wherein the high-viscosity resin is a polycarbonate resin containing silica fine particles or an acrylic resin containing silica fine particles. The method for molding a resin component according to claim 1 or 2, wherein the high viscosity resin includes 20 wt% to 30 wt% of silica fine particles in a polycarbonate resin or an acrylic resin. . 5. The method for molding a resin part according to claim 4, wherein the silica fine particle-containing polycarbonate resin or the silica fine particle-containing acrylic resin has an average particle diameter of silica fine particles of 380 nm or less. 5. The method for molding a resin part according to claim 4, wherein the silica fine particle-containing polycarbonate resin or the silica fine particle-containing acrylic resin has an average particle diameter of silica fine particles of 200 nm or less in visible light. A molding apparatus used for molding at least two types of resins having different viscosities, the low-viscosity resin sprue for introducing the low-viscosity resin into the molding apparatus, the low-viscosity resin cavity for molding the low-viscosity resin, and The low-viscosity resin molding section comprising the low-viscosity resin hot runner that is connected to the low-viscosity resin sprue to guide the low-viscosity resin to the low-viscosity resin cavity, and the high-viscosity resin is introduced into the molding apparatus. Sprue for resin, cavity for high viscosity resin for molding the high viscosity resin, hot runner for high viscosity resin connected to the sprue for high viscosity resin and guiding the high viscosity resin to the cavity for high viscosity resin, the high viscosity A slide core for changing the volume of the resin cavity, and the high-viscosity resin cavity connected to the slide core and reciprocating hydraulically Characterized in that it comprises a high-viscosity resin molded portion comprising a plunger for varying the volume, the resin component molding apparatus. A hydraulic working chamber for driving the plunger, a resin pressure measuring piezoelectric element for detecting the pressure of the high-viscosity resin cavity, a hydraulic pressure measuring piezoelectric element for detecting hydraulic pressure, and the hydraulic pressure measuring piezoelectric element and the resin pressure measurement 9. The resin component molding apparatus according to claim 8, further comprising a hydraulic pressure display voltmeter and a resin pressure display voltmeter for displaying an electric signal from the piezoelectric element as a voltage.

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