JP2003080573A - Method and apparatus for manufacturing plastic molding as well as molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for manufacturing a plastic molding capable of affording the molding having a highly accurate shape and dimension by making a thermal stress to a transfer surface uniform with good productivity and to provide the molding. SOLUTION: The method for manufacturing the plastic molding 1 comprises a step of molding a resin material in a mold heated to a thermal deformation temperature or higher. The method further comprises a resin cooling step of controlling a temperature of a part or entirety of a non-transfer surface adjacent to the transfer surface in naturally cooling the transfer surfaces 9a, 9b of the molding 1 and gradually cooling it after removing the molding 1 having one or more opposed transfer surfaces 9a 9b and one or more non-transfer surfaces adjacent to the transfer surfaces from the mold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a plastic molded product, a manufacturing apparatus, and a molded product which are required to have highly accurate shapes and dimensions, and a laser type digital copying machine,
Optical scanning system of laser printer or facsimile machine,
The present invention relates to a method and an apparatus for manufacturing a plastic molded product applied to optical equipment such as a video camera. Further, the present invention relates to a method for manufacturing a plastic molded product such as a plastic lens having a highly accurate optical mirror surface, a manufacturing apparatus, and the molded product.

[0002]

2. Description of the Related Art In recent years, plastic molded products of various shapes have come to be used for various purposes. As a manufacturing method thereof, it is general to use an injection molding method which has a low manufacturing cost and is suitable for mass production. When manufacturing by the injection molding method, in the step of injection-filling the resin material heated and melted in the mold and cooling and solidifying, the resin pressure and the resin temperature in the mold are made uniform to obtain a desired shape and Dimensional accuracy and internal distortion accuracy are ensured.

[0003]

However, in the conventional injection molding method, there has been a case where the accuracy is greatly reduced and the required accuracy cannot be satisfied. Here, the cause of the decrease in accuracy when the conventional injection molding method is used will be described with reference to FIG.
A desired cavity shape is transferred with high precision using an injection molding method, the resin is cooled, and then the mold is opened to take out a plastic molded product. At this time, the difference between the temperature of the molded product and the ambient temperature around the mold (outside air temperature, generally room temperature) is very large, and the molded product is rapidly cooled. Therefore, Fig. 12 (b)
Taking the shape of the molded product shown in (1) as an example,
The thickened cross-section portion 15 shown in FIG. 12A has a different cooling state. In other words, the thin section 15 has a high cooling rate and thus solidification proceeds quickly, while the thick section 15 has a low cooling rate and thus slows solidification.

In other words, the difference between the surface temperature and the internal temperature of the molded product is small in the thin section 15 as shown in FIG. 12 (d) and large in the thick section 15 as shown in FIG. 12 (c). Means to become. (FIGS. 12 (c) and 12 (d) show the temperature distribution of the difference between the surface temperature and the internal temperature of the molded product by the isotherms). At this time, when the mold temperature (molded product temperature at the time of taking out) is equal to or higher than the thermal deformation temperature of the resin material used, the difference between the above surface temperature and the internal temperature causes the thermal stress inside the molded product, It causes deterioration of shape and dimensional accuracy due to thermal stress and new strain outside the mold. Therefore, no matter how much molding is performed by using the conventional injection molding method and the cavity shape is transferred to the molded product side with high accuracy in the mold to maintain the internal uniformity, it is possible to perform the molding as shown in FIGS. As shown in (), the accuracy is lowered after taking out from the mold.

That is, in the process of manufacturing a plastic molded product, if the mold take-out temperature is equal to or higher than the heat distortion temperature of the resin material used and there is a significant temperature difference between the heat distortion temperature and the ambient temperature, the molded product is thick-walled. If it is a shape,
Improvement is necessary when the molded product satisfies the three conditions when high-precision shapes and dimensions are required, and of course, the temperature control conditions should also be arbitrarily determined depending on the precision required in. There is a problem in that there is.

In order to solve the above-mentioned problems, a method for carrying out slow cooling outside the mold is disclosed in Japanese Patent Laid-Open No. 205205/1995.
In the publication, the mold cavity surface temperature is cooled to a temperature not higher than 10 ° C. higher than the heat deformation temperature of the thermoplastic resin, and thereafter,
It is disclosed that the molded product is taken out of the mold cavity, placed in a furnace heated to a temperature not lower than the thermal deformation temperature of the thermoplastic resin, held for 3 minutes or more, and then gradually cooled to around room temperature.

In this method, however, the molded product is taken out of the mold cavity, placed in a furnace heated to a temperature not lower than the thermal deformation temperature of the resin material used, held for 3 minutes or more, and then gradually cooled. Regarding the conditions, JP-A-7-205239 does not particularly mention that the slow cooling start temperature is equal to or higher than the heat distortion temperature of the resin material used, and substantially matches the mold temperature (120 ° C.) at the time of taking out. Put in a heating furnace at the specified temperature,
After holding for 15 minutes, it is gradually cooled to near room temperature at a cooling rate of 0.5 ° C./min. However, this method holds for 15 minutes and then cools from 120 ℃ to 25 ℃ at a cooling rate of 0.5 ℃ / mi.
Since it takes a total of 205 minutes by gradually cooling with n, there is a problem in productivity. This increase in the slow cooling time leads to an increase in the cost of the plastic molded product. Furthermore, since the heat radiation amount of the entire plastic molded product must be reduced, the temperature control device becomes large.

Further, when the molded product is required to have a highly precise shape and size, the gradual cooling is not carried out after the die is taken out and before a remarkable temperature difference occurs between the surface temperature and the internal temperature of the plastic molded product. However, in the manufacturing process of plastic molded products, since the molded product that has been ejected from the mold requires processes such as taking out, gate cutting, and conveying to a temperature control device, the slow cooling process is actually required. Before performing, the shape and dimensional accuracy of the molded product deteriorate.

In order to solve this problem, it is necessary to carry the material to the temperature control device in the shortest possible time, but it is difficult to shorten the time in the case of molding a large number of pieces. It is also possible to introduce a device that does not lower the temperature of the molded product while the molded product protruding from the mold is taken out, gate cut, and conveyed to the temperature control device. However, there is a problem in that expensive capital investment is forced.

Therefore, an object of the present invention is to provide a method and an apparatus for manufacturing a plastic molded product, by which a plastic molded product having a highly precise shape and size can be obtained with high productivity by equalizing the thermal stress on the transfer surface. And to provide molded products.

[0011]

In order to achieve the above object, the invention as set forth in claim 1 is a method for producing a plastic molded product, which comprises molding a resin material with a mold heated to a temperature higher than a heat deformation temperature, The transfer surface of a plastic molded product is naturally cooled in a resin cooling step after taking out a plastic molded product having one or more transfer surfaces facing each other and one or more non-transfer surfaces adjacent to the transfer surface from a mold. On the other hand, a part or the whole of the non-transfer surface adjacent to the transfer surface is temperature-controlled and gradually cooled.

According to the first aspect of the invention, by gradually cooling the non-transfer surface adjacent to the transfer surface of the molded product, the shape and dimensional accuracy is deteriorated due to thermal stress, and new distortion is caused outside the mold. Make it difficult to occur.

Here, the transfer surface is a surface in which the cavity shape is directly contacted with the molded product in the mold to be transferred with high accuracy, and the transfer accuracy to the mold is an essential part (location) for the function of the part. ). The transfer surface means an optical (lens) surface when the plastic molded product is a plastic lens, for example. The non-transfer surface is a surface other than the transfer surface, and is a surface that does not cause a problem in the function of parts even if the transfer accuracy to the mold is lower than that of the transfer surface. As the non-transfer surface,
For example, when the cross section of a rectangular plastic molded product as shown in FIG. 5 (a) has ribs as shown in FIG. 7, it refers to the side face portion of the plastic molded product shown by the thick line portion.

By gradually cooling the non-transferred surface of the molded product,
Although it is not clear why the shape and dimensional accuracy is deteriorated due to thermal stress and a new strain outside the mold is less likely to occur, as shown in FIG. It is considered that the shape and the dimensional accuracy are improved because the temperature changes and the thermal stress on the transfer surface is made uniform.
That is, in the case of naturally cooled (rapidly cooled) FIG. 5B, the end of the transfer surface (see FIG.
When the non-transfer surface adjacent to the transfer surface is annealed, the transfer is performed when the non-transfer surface adjacent to the transfer surface is gradually cooled. The thermal stress that is pulled to the center at the center position of the surface in the Y direction and at the end becomes uniform. It is considered that this contributed to the improvement of the shape and dimensional accuracy.

The shape of the plastic molded article according to claim 1 is not limited, and examples thereof include a plastic lens. The shape of the molded article is thick, and the shape is applicable to all shapes capable of obtaining the effect of temperature control. be able to.

Further, with respect to the transfer surface (optical surface) shape which requires a highly accurate shape and dimension, it can be applied to any shape such as a flat surface, a spherical surface, an aspherical surface, a free curved surface.

The resin material used for the plastic molded product is not particularly limited, and it can be applied to all resin materials having a temperature control effect regardless of crystallinity and amorphousness. In other words, any resin material can be applied as long as the mold temperature is equal to or higher than the heat deformation temperature of the resin material and a plastic molded product having a significant temperature difference between the heat deformation temperature and the ambient temperature can be molded.

A plastic molded article is obtained by performing a step of molding a resin material into a desired molded article shape in a mold by an injection molding method, and is characterized by temperature control in a resin cooling process after mold release. Therefore, it is applicable not only to the injection molding method but also to various molding methods such as injection compression / press molding, gas assist molding and extrusion molding.

FIG. 3 (b) is a graph showing changes in the resin temperature during the manufacturing process of the plastic molded product. Form a desired shape from a molten resin or a blank resin (this is not particularly limited depending on the molding method),
In the resin cooling process of the plastic molded product manufacturing process,
After taking out the plastic molded product from the mold, the non-transfer surface adjacent to the transfer surface of the plastic molded product is gradually cooled. The solid line part in the graph shows the temperature change of the transfer surface, and the dotted line part shows the non-transfer surface. From the graph, the transfer surface is gradually cooled by natural cooling after being taken out from the mold, so the temperature drops sharply and exceeds the heat deformation temperature range of the resin material.
It can be seen that the temperature drop on the non-transfer surface is gentle.

According to a second aspect of the present invention, in the resin cooling step according to the first aspect of the present invention, a part of the non-transfer surface adjacent to the transfer surface is temperature-controlled to be locally gradually cooled. To do.

In the invention described in claim 2, claim 1
Since the temperature control in the described invention is to equalize the thermal stress to the transfer surface, the region with a thicker lens (center position in the longitudinal direction of the molded product) causes a large decrease in shape and dimension accuracy due to rapid cooling, Naturally, the effect of temperature control is great, so in the non-transfer surface adjacent to the transfer surface of the molded product, it is necessary to gradually cool a part of the side adjacent to the transfer surface as in the case where only the thick line portion in FIG. 6 abuts. Also, the thermal stress on the transfer surface can be made uniform, and the shape and dimension accuracy can be improved.

According to a third aspect of the present invention, in the resin cooling step according to the first aspect of the present invention, as a method for gradually cooling a part or all of the non-transfer surface adjacent to the transfer surface, a transfer surface of a plastic molded product is used. The heat-insulating member is made to face a part or all of the non-transfer surface adjacent to, and is gradually cooled.

According to the invention of claim 3, claim 1
In the described invention, by installing the heat insulating member so as to face both sides (non-transfer surface) of the plastic molded article,
Reduce heat transfer from both sides of the plastic molded part,
It is also possible to gradually cool the non-transfer surface adjacent to the transfer surface of the plastic molded product.

According to a fourth aspect of the present invention, in the resin cooling step of the first aspect of the present invention, as a method for gradually cooling a part or all of the non-transfer surface adjacent to the transfer surface, a transfer surface of a plastic molded product is used. It is characterized in that a member having a temperature control means is brought into contact with a part or all of the non-transfer surface adjacent to and is gradually cooled.

In the invention described in claim 4, claim 1
In the invention described, as a configuration of the temperature control device of the plastic molded product after mold release, a member having a temperature control means is prepared beside the manufacturing apparatus, and the non-transfer surface of the plastic molded product taken out from the mold Install so that they abut.
A heating element and a thermocouple can be used inside the member having the temperature control means. The heating element and the thermocouple are connected to the temperature control device, but the shape of the heating element is not particularly limited, and various electric heating elements such as a rod shape, a plate shape, a film shape, and a plane shape can be used. .

According to a fifth aspect of the present invention, in the resin cooling step according to the first aspect of the present invention, as a method for gradually cooling a part or all of the non-transfer surface adjacent to the transfer surface, the transfer surface of a plastic molded product is used. And a member having a temperature control means and a part or the whole of the non-transfer surface adjacent thereto are provided at intervals to gradually cool.

In the invention described in claim 5, claim 1
In the invention described above, it is possible to gradually cool the non-transfer surface adjacent to the transfer surface of the plastic molded product by providing a space so as to be close to both side surfaces of the plastic molded product.

According to a sixth aspect of the present invention, in the resin cooling step according to the first aspect of the present invention, a member having temperature control means is provided as a method for gradually cooling a part or all of the non-transfer surface adjacent to the transfer surface. It is characterized by slow cooling using the radiant heat of.

According to the invention of claim 6, claim 1
In the invention described above, the side surface of the molded product is gradually cooled by the radiant heat of the heating element.

According to a seventh aspect of the present invention, in the resin cooling step of the first aspect of the present invention, as a method for gradually cooling a part or all of the non-transfer surface adjacent to the transfer surface, a transfer surface of a plastic molded product is used. It is characterized in that a temperature-controlled gas is blown onto a part or the whole of the non-transfer surface adjacent to, and is gradually cooled.

According to the invention of claim 7, claim 1
In the invention described, as a method of providing a temperature control means around the manufacturing apparatus, as a method of gradually cooling a part of the non-transfer surface of the plastic molded product taken out from the mold, adjacent to the transfer surface,
Spray a temperature-controlled gas. The gas to be blown can be arbitrarily selected as long as it does not adversely affect the plastic material, such as air and nitrogen gas.

An eighth aspect of the invention is characterized in that the plastic molded article according to the first aspect of the invention is subjected to primary slow cooling and then to secondary slow cooling.

According to the invention of claim 8, claim 1
By performing slow cooling of the described plastic molded product in multiple stages, if the molding cycle of the plastic molded product is short,
Since the temperature distribution that cannot be removed by the primary slow cooling is succeeded by the subsequent slow cooling and the non-transfer surface adjacent to the transfer surface of the plastic molded product can be gradually cooled, highly accurate plastic molded products can be produced. It can be manufactured well.

The invention according to claim 9 is a temperature control having any means for gradually cooling a part or all of the non-transfer surface adjacent to the transfer surface of the plastic molded article according to the inventions of claims 3 to 7. It is an apparatus for manufacturing a plastic molded product provided with the apparatus.

In the invention described in claim 9, claim 3
The thermal stress on the transfer surface can be made uniform by the apparatus for manufacturing a plastic molded product used in the inventions of the manufacturing methods described in 1 to 7, and the non-transfer surface where improvement in temperature distribution can be expected can be gradually cooled.

A tenth aspect of the present invention is characterized in that the temperature control device according to the ninth aspect is attached to a device for taking out a plastic molded product.

According to the tenth aspect of the present invention, the temperature of the plastic molded product can be controlled immediately after the mold is opened by providing the takeout device of the plastic molding device. Further, the step of taking out the molded product and the step of gradually cooling can be performed at the same time, and by reducing the number of steps in the plastic manufacturing process, the plastic molded product can be obtained with high productivity.

The invention according to claim 11 is characterized in that the temperature control device for performing the primary slow cooling and the secondary slow cooling is the temperature controlling device according to the eighth aspect.

In the eleventh aspect of the present invention, the combination of temperature control devices for gradually cooling the non-transfer surface in multiple stages is not particularly limited.

The invention described in claim 12 is characterized in that the transfer surface is an optical surface and is manufactured by the method for manufacturing a plastic molded product according to any one of claims 1 to 7 or 10.

According to the twelfth aspect of the present invention, a plastic molded product such as a plastic lens applied to a photographing lens for a lens shutter camera or a single-lens reflex camera by the manufacturing method according to the first to seventh or tenth aspects, for example, A convex lens like the camera lens shown in FIG. 8A is obtained.

[0042]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0043]

Example 1 FIG. 1A is a perspective view of the shape of a plastic molded product taken out from a mold in Example 1.
As shown in FIG. 1 (a), as a plastic molded product, the lens thickness (a) at the central portion is 14 mm, the lens thickness (b) at the end portion is 6 mm, and the length (c) in the lateral direction is 15 m.
m, the length (d) in the longitudinal direction is 260 mm, which is a thermoplastic cycloolefin polymer, ZEONEX (manufactured by Zeon Corporation), (heat distortion temperature (deflection temperature under load) 123 ° C., test method ASTM D648,
The glass transition temperature of 138 ° C) is used to heat and hold the mold at 135 ° C, which is below the softening temperature of the resin (below the glass transition temperature), and then the molten resin at 280 ° C is placed in the cavity of the mold. Injection filled. Then, after holding the cooling time in the mold for 800 seconds, the molded product was released from the mold. Here, it is assumed that the mold temperature is substantially the same as the upper limit temperature at which the temperature control is performed, and is maintained at a constant temperature.

FIG. 2 is a schematic view showing a member having a pair of temperature control means provided near the molding machine as a temperature control device after releasing the mold. The temperature control means was installed so as to contact both side surfaces (non-transfer surface) of the plastic molded product taken out from the mold. In FIG. 2, reference numerals 9a and 9b
Is a transfer surface and is provided with a cartridge heater 3 and a thermocouple 5 as a member having a temperature control means, and the cartridge heater 3 and the thermocouple 5 are connected to a temperature adjusting device (not shown).

The output of the cartridge heater 3 is initially set in the temperature control device so that the thermocouple 5 can be controlled within the same temperature as the mold temperature of 135 ° C., and the non-transfer surface of the plastic molded product is set from there. It was set so as to gradually cool to 100 ° C. at 1 ° C./min.

Next, as the shape evaluation, the shape was measured by a stylus type three-dimensional measuring machine and the deviation amount from the design value of the molded product was evaluated. To be precise, coordinate values in the sub-scanning (short) direction (see FIG.
The amount of deviation from the design value of the molded product in the lens thickness direction (Z direction in FIG. 1B) with respect to the Y direction in (b) is determined for each main scanning (longitudinal) direction coordinate value (X direction in FIG. 1B). The PV value of the graph plotted in FIG.

From the shape measurement results, in the naturally cooled molded product shown by the thin line in the graph of FIG. 4C, the thick lens region (center position in the longitudinal direction of the molded product) of the graph of FIG. 4B showing the lens shape. The accuracy of the shape and dimension decreased. It was 3 μm at the center position in the longitudinal direction of the molded product. However, in the molded product in which the non-transfer surface adjacent to the transfer surface indicated by the thick line in the graph of FIG. 4 (c) was temperature-controlled and gradually cooled, the result was 0.5 μm, which was confirmed to improve the shape and dimension accuracy.

[0048]

[Embodiment 2] Embodiment 2 will be described with reference to the perspective view of the plastic molded product shown in FIG. The plastic molded product comprises a transfer surface 9a and a non-transfer surface 13a.

The apparatus is constructed such that a temperature control means is provided beside the molding machine, and the non-transfer surface 13a of the plastic molded product taken out from the mold is adjacent to the transfer surface 9a, and is located on the side adjacent to the transfer surface 9a. As a method of gradually cooling the part, a temperature-controlled gas is blown in the direction of the arrow. Non-transfer surface 1
It was set so that a part of the 3a adjacent to the transfer surface 9a (hatched part in FIG. 9) was gradually cooled to 100 ° C. at 1 ° C./min.

[0050]

Third Embodiment A third embodiment will be described with reference to the configuration diagram (a) and the perspective view (b) of FIG. The temperature adjusting device includes a plastic molded product 1, a mold 2, a take-out machine arm portion 19, a molded product holding portion 21, and a temperature control device 23.

The third embodiment is a method of manufacturing the plastic molded product 1 in which the temperature control device 23 is provided on the take-out machine arm portion 19 of the plastic molding device. An infrared heater is used as the temperature control device 23, and the non-transfer surface of the plastic molded product 1 is heated to 3 ° C / min at 100 ° C by radiant heat.
It is gradually cooled to. By providing the pick-up device arm portion 19, the temperature of the plastic molded product 1 can be controlled immediately after the mold is opened. Furthermore, the step of taking out the molded product and the step of gradually cooling can be performed at the same time, and by reducing the number of steps in the plastic manufacturing process, a highly accurate plastic molded product can be obtained with high productivity.

[0052]

[Embodiment 4] Embodiment 4 will be described with reference to FIG. 11 (a), a perspective view (b) and a front view (c) of a member having a temperature control device. In FIG. 11, the member having the temperature control device 23 includes a plastic molded product 1, a mold 2, and transfer surfaces 9a and 9b. The temperature control means includes a cartridge heater 3 and a thermocouple 5 therein, and the cartridge heater 3 and the thermocouple 5 are connected to a temperature adjusting device (not shown). Reference numeral 19 is a take-out machine arm portion, 21 is a molded product holding portion, and 23 is a temperature control device. Example 4 is
The temperature control device 23 is a method of manufacturing a plastic molded product provided on the take-out machine arm portion 19 of the plastic molding device. As for the constitution of the apparatus, a member having a pair of temperature control means is provided in the take-out machine arm portion 19. A portion for supporting the plastic molded product 1 is separately provided, and members having temperature control means are brought close to both side surfaces (non-transfer surface) of the plastic molded product 1. A cartridge heater 3 and a thermocouple 5 are provided inside a member having a temperature control means, and the cartridge heater 3 and the thermocouple 5 are connected to a temperature adjusting device.

Next, the thermocouple 5 has an output of the cartridge heater 3 initially set in a temperature adjusting device so that the thermocouple 5 can be controlled within a temperature similar to the mold temperature (135 ° C.). 1 side is 100 at 3 ℃ / min
It was set to be gradually cooled to ℃. As a result, the non-transfer surface adjacent to the transfer surfaces 9a and 9b of the plastic molded product 1 can be gradually cooled. By providing the member having the temperature control means in the take-out machine arm portion 19, the temperature of the plastic molded product 1 can be controlled immediately after opening the mold. Further, a step of taking out the plastic molded product 1,
The step of gradually cooling can be performed at the same time, and by reducing the number of steps in the plastic manufacturing process, a highly accurate plastic molded product can be obtained with high productivity.

[0054]

[Embodiment 5] With the same device configuration as that of Embodiment 4, a temperature control device is provided on a take-out machine arm of a plastic molding device. Next, the output of the cartridge heater is initially set in the temperature control device so that the thermocouple can be controlled within the same temperature as the mold temperature of 135 ° C., and the non-transfer surface of the plastic molded product is set to 2 ° C. It was set to gradually cool to 120 ° C. at a flow rate of min / min. Further, as secondary cooling, a side surface of the plastic molded product was set to be gradually cooled from 120 ° C. to 100 ° C. at 1 ° C./min in a temperature control device separately prepared beside the molding machine.

Immediately after releasing the plastic molded product, the temperature control device attached to the device for taking out the plastic molded product carries out primary cooling, and then another cooling device carries out secondary cooling. The non-transfer surface adjacent to the transfer surface can be gradually cooled.In addition, if the molding cycle of the plastic molded product is short, the temperature control device attached to the take-out device can prevent the temperature distribution from exceeding the temperature distribution. Since the control device can take over and gradually cool the non-transfer surface adjacent to the transfer surface of the plastic molded product, a highly accurate plastic molded product can be manufactured with high productivity.

[0056]

According to the first aspect of the invention, the effect of thermal stress on the transfer surface can be made uniform, and the transfer surface is isotropically contracted. Therefore, the accuracy of the shape of the transfer surface can be improved, and a highly accurate plastic molded product can be manufactured.

According to the second aspect of the present invention, the effect of the thermal stress exerted on the transfer surface is made uniform by only local slow cooling without gradually cooling the entire surface other than the transfer surface adjacent to the transfer surface. The transfer surface is isotropically contracted. Therefore, the accuracy of the shape of the transfer surface can be improved, and a highly accurate plastic molded product can be manufactured.

According to the third aspect of the present invention, since no other heat source is required, a highly accurate plastic molded product can be manufactured at low cost.

According to the fourth aspect of the present invention, the amount of heat can be efficiently transmitted to the molded product, and a highly accurate plastic molded product can be manufactured at low cost.

In the invention described in claims 5 to 6, non-contact temperature control is possible.

According to the invention described in claim 7, non-contact temperature control is possible, and the non-transfer surface can be gradually cooled uniformly.

In the invention described in claim 8, the temperature can be controlled immediately after the mold is opened, and the step of taking out the molded product and the step of slow cooling can be performed at the same time. By reducing the number, a plastic molded product can be obtained with high productivity.

In the invention described in claim 9, immediately after the mold release,
A part of or all of the surfaces other than the transfer surface adjacent to the transfer surface of the plastic molded product can be gradually cooled, and when the molding cycle of the plastic molded product is short, a temperature control device attached to the take-out device. The temperature control device takes over the temperature distribution that cannot be completely removed by the temperature control device, and part or all of the surface of the plastic molded product other than the transfer surface adjacent to the transfer surface can be gradually cooled. Can be manufactured with high productivity.

According to the tenth aspect of the invention, the effect of thermal stress on the transfer surface can be made uniform, and the transfer surface is isotropically contracted. Therefore, the shape dimension accuracy of the transfer surface can be improved, and an apparatus for manufacturing a highly accurate plastic molded product can be obtained. In the invention according to claim 11, an apparatus for manufacturing a highly accurate plastic molded product with high productivity. Can be obtained.

According to the twelfth aspect of the present invention, it is possible to obtain a plastic molded product such as a lens, a mirror or a prism, which has good shape and dimension accuracy, good internal uniformity and excellent optical performance.

[Brief description of drawings]

FIG. 1 shows a molded product of Example 1, (a) is a perspective view,
(B) is a figure which shows a direction.

FIG. 2 is a configuration diagram schematically showing a state in which a plastic molded product is gradually cooled.

FIG. 3 shows a plastic molded product, (a) is a perspective view,
(B) is a graph showing a resin temperature change in the manufacturing process.

FIG. 4 shows shape evaluation of a molded product of the present invention, (a) is a schematic view, (b) is a graph showing a lens shape, and (c) is a graph showing a result of shape measurement.

FIG. 5 shows a rectangular plastic molded product, (a) is a perspective view, (b) is a temperature distribution diagram of the molded product when naturally cooled, and (c) is a molded product when the non-transfer surface is gradually cooled. FIG. 3D is a schematic diagram showing a contracted state of the molded product when naturally cooled, and FIG. 6E is a schematic diagram showing a contracted state of the molded product when the non-transfer surface is gradually cooled.

FIG. 6 is a configuration diagram schematically showing a state where a part of the non-transfer surface of the plastic molded product is gradually cooled.

FIG. 7 is a configuration diagram schematically showing a conventional example.

FIG. 8 shows a convex lens manufactured by the manufacturing method of the present invention, in which (a) is a cross-sectional view and (b) and (c) are temperature distribution diagrams.

FIG. 9 is a perspective view showing a second embodiment.

10A and 10B show a third embodiment, wherein FIG. 10A is a sectional view and FIG. 10B is a perspective view.

11A and 11B show Example 4, in which FIG. 11A is a sectional view, FIG. 11B is a perspective view, and FIG.

12 shows a conventional example, (a) is a perspective view of a thick molded product, (b) is a perspective view of a thin molded product, (c) is a temperature distribution diagram of a thick molded product, (d) ) Is a temperature distribution chart of a thin-walled molded product, (e) is a schematic diagram showing a contracted state of a thick-walled molded product,
(F) is a schematic diagram showing a contracted state of a thin molded product.

[Explanation of symbols]

1 plastic molded products 2 mold 3 Cartridge heater 5 thermocouple 9a, 9b Transfer surface 13a Non-transfer surface 15 Section 19 Extractor arm 21 Molded product holder 23 Temperature control device

Continued front page    (72) Inventor Kiyotaka Sawada             1-3-3 Nakamagome, Ota-ku, Tokyo Stocks             Company Ricoh F-term (reference) 4F202 AA03 AH73 CA11 CB01 CM11                       CN05 CN30                 4F206 AA03 AH73 JA07 JW15

Claims (12)

[Claims] 1. A method for manufacturing a plastic molded product, which comprises molding a resin material in a mold heated to a temperature higher than a heat distortion temperature, in which one or more transfer surfaces facing each other and one or more non-transfer surfaces adjacent to the transfer surface. In the resin cooling process after taking out the plastic molded product having the surface from the mold, the transfer surface of the plastic molded product is naturally cooled, while the temperature of a part or all of the non-transfer surface adjacent to the transfer surface is controlled. A method for producing a plastic molded product, which comprises slowly cooling by slowing down. 2. The method for producing a plastic molded article according to claim 1, wherein in the resin cooling step, a part of the non-transfer surface adjacent to the transfer surface is temperature-controlled and locally cooled gradually. 3. A method of gradually cooling a part or all of a non-transfer surface adjacent to a transfer surface in a resin cooling step, wherein a part or all of the non-transfer surface adjacent to the transfer surface of a plastic molded product is heat-insulating member. The two are faced to each other and gradually cooled.
A method for producing the described plastic molded product. 4. A method for gradually cooling a part or all of a non-transfer surface adjacent to a transfer surface in a resin cooling step, wherein temperature control is carried out on part or all of the non-transfer surface adjacent to the transfer surface of a plastic molded article. The method for producing a plastic molded article according to claim 1, wherein a member having a means is brought into contact with the member and gradually cooled. 5. A method for gradually cooling a part or all of a non-transfer surface adjacent to a transfer surface in a resin cooling step, for controlling a part or all of the non-transfer surface adjacent to the transfer surface of a plastic molded article and temperature control. The method for producing a plastic molded article according to claim 1, wherein members having means are provided at intervals and gradually cooled. 6. A method for gradually cooling a part or all of a non-transfer surface adjacent to a transfer surface in a resin cooling step, characterized by using radiant heat of a member having a temperature control means. The method for producing a plastic molded article according to claim 1. 7. A method for gradually cooling a part or all of a non-transfer surface adjacent to a transfer surface in a resin cooling step, wherein temperature control is carried out on part or all of the non-transfer surface adjacent to the transfer surface of a plastic molded article. The method for producing a plastic molded article according to claim 1, wherein the produced gas is blown and gradually cooled. 8. The method for producing a plastic molded product according to claim 1, wherein the plastic molded product is first annealed and then secondly annealed. 9. A plastic molded article provided with a temperature control device having means for gradually cooling part or all of the non-transfer surface adjacent to the transfer surface of the plastic molded article according to claim 3. apparatus. 10. An apparatus for manufacturing a plastic molded product, wherein the temperature control device according to claim 9 is attached to a device for taking out a plastic molded product. 11. An apparatus for producing a plastic molded article, wherein the temperature control device for performing the primary slow cooling and the secondary slow cooling is the temperature controlling device according to claim 8. 12. A plastic molded product, characterized in that the transfer surface is an optical surface and is manufactured by the method for manufacturing a plastic molded product according to any one of claims 1 to 7 or 10.