JP2009214298A - Resin molding and method for producing resin molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a resin molding which can accurately transfer a mold transfer surface in which minute unevenness, an optical specular surface, etc., are formed in a resin surface without heating a mold at a high temperature by using a plasticization effect by carbon dioxide dissolved in the resin, control the generation of bubbles, and materialize the shortening of a cycle time to be equivalent to that in injection molding. <P>SOLUTION: In the method for producing the resin molding in which by impregnating the resin molding with carbon dioxide and pushing the transfer surface of the mold to the surface of the resin molding, the pattern of the transfer surface is transferred to the surface of the resin molding, the resin molding which is composed of a laminate of at least two layers and composed of a laminate of at least two resin members different in carbon dioxide diffusion speed at the same temperature and pressure is used. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method and apparatus for manufacturing an optical element having a highly accurate optical mirror surface or fine pattern on the surface.

As a method for producing a resin molded product, an injection molding method is generally used. The injection molding method is a method in which a molten resin is filled in a mold cavity that is heated and maintained at a temperature equal to or lower than its softening temperature and solidified. Immediately after the resin is filled in the cavity, cooling and solidification starts, and a molded article having a three-dimensional shape can be produced with a very fast molding cycle. However, in this case, the resin is cooled immediately after the resin is filled in the cavity to form a solidified layer. Therefore, in a molded product having a fine concavo-convex pattern on the surface, such as a diffraction lens or a light guide plate, the resin is There arises a problem that the fine concavo-convex pattern is solidified before being closely packed.
A thermal imprint method is known as a method for transferring the fine pattern described above to the resin surface. This is a method in which the resin is heated to the softening temperature or higher, the transfer surface on which the fine pattern is formed is pressed against the resin surface to transfer the pattern, and then cooled to the softening temperature or lower to release. In this case, since the resin is heated to the softening temperature or higher when the transfer surface is pressed, the fine pattern can be filled, but a heating / cooling process is required, and the molding time is very long. Problem arises.

In order to solve such problems, in recent years, a plurality of attempts have been made to apply carbon dioxide to molding processing. It is known that when an inert gas such as carbon dioxide is dissolved in a resin at a high pressure, the resin is plasticized and its softening temperature is lowered, and this property is applied.
For example, Patent Document 1 proposes a method of filling a mold cavity with carbon dioxide gas in advance and then filling a resin into the mold cavity.
In Patent Document 2, a gap is formed between the mold and the skin layer on the resin surface, carbon dioxide gas is injected into the gap, the holding pressure is increased again, the skin layer and the transfer surface are brought into close contact, and the transfer is performed. The surface is transferred.
In Patent Document 3, carbon dioxide is applied to the imprint method. Here, by introducing high-pressure carbon dioxide into the sealed container, the base material of the thermoplastic resin is impregnated with carbon dioxide, and then the mold transfer surface lower than the glass transition temperature of the base material is pressed against the base material to be transferred. . Thereafter, the inside of the sealed container is depressurized to discharge carbon dioxide from the base material.
In this case, since the plasticization is promoted by impregnating the base material with carbon dioxide, the fine pattern can be transferred without raising the base material or the mold to a high temperature, and the molding time can be expected to be shortened.
Patent No. 3096904 Japanese Patent No. 3445778 JP 2006-175756 A

However, in the invention described in Patent Document 1, the viscosity of the resin is reduced and the filling of the fine pattern is promoted. However, since the carbon dioxide is dissolved along with the flow of the resin, the flow becomes unstable. Along with this, appearance defects occur in the molded product. In addition, since the resin is filled into the cavity pressurized with the high-pressure gas, a problem such as unfilling of the resin tends to occur.
Further, in the invention described in Patent Document 2, carbon dioxide can be dissolved without causing resin flow. However, a sliding portion is required around the transfer surface in order to re-adhere, and a gas leak or the like therefrom. If high pressure gas cannot be injected stably and pressure is applied by holding pressure, stress concentrates only in the vicinity of the gate, which is the resin inlet, and the pressure is uniformly applied to the transfer surface. There arises a problem that it cannot be loaded.

Further, in the invention described in Patent Document 3, when the above method is applied to a molded article having a particularly large thickness, the impregnation time of carbon dioxide and the decompression time for discharging carbon dioxide from the base material become long. The molding time cannot be shortened to the extent comparable to injection molding. In addition, when rapid decompression is performed to shorten the decompression time, carbon dioxide that has penetrated into the interior cannot be completely removed, phase separation proceeds, and bubbles are generated.
In that case, the impregnation time and the pressure reduction time can be shortened and bubbles can be suppressed by selectively impregnating only the transfer surface layer with carbon dioxide. The impregnation depth of carbon dioxide is determined by the impregnation time, impregnation pressure, impregnation temperature, etc., but since they influence each other, it is difficult to control accurately, stably, and transfer surface There is a problem that only the surface layer portion cannot be impregnated with carbon dioxide selectively.
The present invention has been made in view of such conventional problems, and by utilizing the plasticizing effect of carbon dioxide dissolved in the resin, the resin surface has a fine structure without raising the mold to a high temperature. Providing a method for manufacturing resin molded products that can transfer mold transfer surfaces with irregularities and optical mirror surfaces with high accuracy, suppress the generation of air bubbles, and achieve cycle times as short as injection molding. The purpose is to do.

In order to solve the above-mentioned problems, the invention according to claim 1 is a resin molding in which a transfer surface of a mold is pressed against a surface of a resin molded body impregnated with carbon dioxide to transfer the pattern of the transfer surface. In the resin molded body used in the manufacturing method of a product, the resin molded body has a laminated structure composed of at least two layers of resin members, and at least the temperature and the pressure are under the same conditions. It is characterized by different diffusion rates of carbon.
The invention according to claim 2 is the invention according to claim 1, wherein the resin molded body is a surface layer resin member pressed against a mold transfer surface, and a base resin member laminated on the back surface of the surface layer resin member; When the temperature and pressure are the same, the diffusion rate of carbon dioxide in the base resin member is slower than the diffusion rate of carbon dioxide in the surface resin member.
The invention according to claim 3 is the intermediate resin member according to claim 1, wherein the intermediate resin member is made of a material different from that of the surface resin member and the base resin member between the surface resin member and the base resin member. When the temperature and pressure are the same, the diffusion rate of carbon dioxide in the intermediate resin member is slower than the diffusion rate in the surface resin member.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the base resin member is processed into a substantially final shape in advance.
The invention according to claim 5 is characterized in that, in any one of claims 1 to 4, all of the resin members constituting the resin molded body are made of a thermoplastic resin material.
The invention according to claim 6 is characterized in that, in any one of claims 1 to 4, the resin member constituting the resin molded body is made of a thermoplastic resin material or a thermosetting resin material. To do.

The invention according to claim 7 is characterized in that, in any one of claims 1 to 4, the resin member constituting the resin molded body is made of a thermoplastic resin material or a photocurable resin material. .
According to an eighth aspect of the present invention, a step of impregnating a resin molded body with carbon dioxide, a transfer surface of a mold is pressed against the surface of the resin molded body, and a pattern of the transfer surface is applied to the surface of the resin molded body. And a step of transferring the resin molded product, wherein the resin molded product is the resin molded product according to any one of claims 1 to 7.
The invention according to claim 9 is the method according to claim 8, wherein the step of impregnating the resin molding with carbon dioxide and the step of pressing the transfer surface of the mold against the surface of the resin molding are carbon dioxide. It is performed below the softening temperature of the surface resin member of the resin molded body before impregnation.

The invention according to claim 10 is the method according to claim 8 or 9, wherein the step of impregnating the resin molding with carbon dioxide and the step of pressing the transfer surface of the mold against the surface of the resin molding are as follows. It is characterized by being carried out at a constant temperature below the softening temperature of the surface resin member of the resin molded body before impregnating with carbon.
An eleventh aspect of the invention is characterized in that in any one of the eighth to tenth aspects, a fine uneven pattern is formed on the transfer surface of the mold.
According to a twelfth aspect of the present invention, in the eleventh aspect, the thickness of the surface layer resin member before pressing the transfer surface of the mold against the surface of the resin molded body is formed on at least the mold transfer surface. It is characterized by being thicker than the height of the fine uneven pattern.
The invention according to claim 13 is the substrate according to claim 12, wherein the thickness of the surface layer resin member before pressing the transfer surface of the mold against the surface of the resin molded body is processed into a substantially final shape in advance. The thickness is equal to or greater than the shape error between the material resin member and the final shape.

In the present invention, when carbon dioxide is dissolved in a resin, attention is paid to the fact that the diffusion rate of carbon dioxide varies depending on the type of resin. From two or more types of resin members having different carbon dioxide diffusion rates under the same temperature and pressure in advance. A resin molded body is prepared, and carbon dioxide is selectively dissolved only in a resin member having a high carbon dioxide diffusion rate in the resin constituting the resin molded body.
Specifically, a resin molded body in which resin members having different carbon dioxide diffusion rates are previously prepared is prepared, and the predetermined thickness of the transfer surface side surface layer portion is configured with a resin member having a high carbon dioxide diffusion rate. Thus, carbon dioxide can be preferentially impregnated and plasticized only in that portion. When the resin molded body is composed of a single resin member, the dissolution of carbon dioxide proceeds to the inside of the resin, but in the present invention, the dissolution does not proceed at the resin member having a slow carbon dioxide diffusion rate. Carbon dioxide can be selectively dissolved only in a resin member having a high carbon dioxide diffusion rate.
Therefore, according to the present invention, in producing a resin molded product by utilizing the plasticizing effect of carbon dioxide dissolved in the resin, the generation of bubbles from the resin member is suppressed, and the impregnation time, impregnation pressure, impregnation are suppressed. Without accurately controlling the temperature or the like, carbon dioxide can be selectively impregnated only on the surface portion of the transfer surface, and the carbon dioxide impregnation time and the decompression time can be stably reduced, that is, the cycle time can be shortened.

  Hereinafter, embodiments of the present invention will be described in detail.

1A and 1B are diagrams showing the structure of a resin used in Example 1. FIG. 1A is a diagram showing a resin molded body before pattern transfer, and FIG. 1B is a diagram showing a resin molded product after pattern transfer.
In this example, a resin molded body 101 having a laminated structure of the surface resin member 102 and the base resin member 103 as shown in FIG. 1A was prepared, and a predetermined pattern was formed on the surface resin member 102. The mold transfer surface was pressed and transferred, and a resin molded product 104 having the uneven pattern 105 transferred onto the surface of the surface resin member 102 as shown in FIG. 1B was produced. Here, in order to distinguish the resin before transfer shown in FIG. 1 (a) from the resin after transfer shown in FIG. 1 (b), they are referred to as a resin molded body 101 and a resin molded product 104, respectively. To do.

Specifically, methacrylic resin (thermal deformation temperature: 85 to 100 degrees, hereinafter referred to as PMMA) as the thermoplastic resin as the surface layer resin member 102, and cycloolefin resin (hereinafter referred to as COP) as the thermoplastic resin as the base resin member 103. The resin molded body 101 having a two-layer structure is used. Although the production method of the resin molded body 101 is not limited, in this embodiment, it was produced using a two-color molding machine having two injection units. Thus, when the resin member which comprises the resin molding 101 is both comprised with the thermoplastic resin, the resin molding 101 can be produced easily and with a high cycle with one molding machine. Further, as shown in FIG. 1, the resin molded body 101 does not have to be formed with a fine pattern, and the final shape may be any portion other than the substantially final shape, that is, the portion to which the fine pattern is transferred. Therefore, the resin molded body 101 can be easily manufactured at a low cost without any special device. Furthermore, the resin molded body 101 can be produced in parallel with the fine pattern transfer step, and an increase in the molding cycle due to an increase in the number of steps does not occur.
However, in this case, the thickness of the surface resin member 102 layer needs to be larger than the height of the concavo-convex pattern formed on the transfer surface 115 of the mold 116. Thereby, even if carbon dioxide is not melted and plasticized on the base resin member 103, the uneven pattern of the mold 116 can be reliably transferred to the resin molded product 104.

FIG. 2 is a schematic cross-sectional view of the resin molded product processing apparatus used in Example 1.
This apparatus has a structure capable of pressing the resin molded body 101 in a high-pressure carbon dioxide atmosphere. Specifically, a sealed container 6 that can accommodate a pre-processed resin molded body 101 is provided, and the sealed container 6 includes a gas supply pipe 7 for supplying carbon dioxide and a gas discharge for discharging carbon dioxide. A tube 8 is connected and communicates with the sealed container 6. The gas supply pipe 7 is connected to a carbon dioxide cylinder 10 via a pressure intensifier 9. The gas supply pipe 7 is provided with a supply valve 11 that can be opened and closed. When the supply valve 11 is opened and closed, carbon dioxide controlled to a predetermined pressure and temperature by the pressure intensifier 9 is appropriately supplied into the sealed container 6. Is done. On the other hand, the attachment port of the gas discharge pipe 8 is provided with a pressure reducing valve 12 capable of adjusting the pressure reducing speed, so that the inside of the sealed container 6 can be maintained at a constant pressure or depressurized at a predetermined speed. Furthermore, a temperature regulator 13 is provided on the outer peripheral portion of the sealed container 6 so that the atmosphere temperature in the sealed container 6 can be maintained at a predetermined temperature as appropriate. In this embodiment, a cartridge heater is used.

Further, in the sealed container 6, there is a lower mold holding part 14 for fixing the resin molding 101 and an upper mold holding part 17 for fixing a mold 116 having a transfer surface 115 on which a predetermined pattern is formed. Is provided. In the processing apparatus used in this embodiment, the upper mold holding part 17 to which the mold 116 is fixed is movable up and down, and the mold is placed on the molding surface of the resin molded body 101 fixed to the lower mold holding part 14. The transfer surface 115 of the mold 116 can be pressed with a predetermined pressure.
In the present embodiment, the lower mold holding part 14 may be moved, or both the upper mold holding part 17 and the lower mold holding part 14 may be movable.

Next, the operation will be described with reference to FIG.
1) The resin molded body 101 that has been processed into a substantially final shape in advance is inserted into the sealed container 6.
2) The atmosphere in the sealed container 6 is replaced with carbon dioxide. The process of replacing the inside of the sealed container 6 with carbon dioxide is easily performed by opening the supply valve 11 and the pressure reducing valve 12 and circulating the carbon dioxide in the sealed container 6 and then closing the supply valve 11 and the pressure reducing valve 12. However, since the pressure increasing device 9 connected to the supply valve 11 is maintained and stored so that the carbon dioxide has a predetermined temperature and pressure, it is better to provide a separate carbon dioxide circulation path for replacement. preferable.
3) The supply valve 11 is opened, the pressure reducing valve 12 is closed, and carbon dioxide is filled into the sealed container 6 from the pressure increasing device 9 in which the carbon dioxide whose pressure has been increased and increased to a predetermined pressure and temperature is stored. 101 is impregnated with carbon dioxide. At this time, the pressure reducing valve 12 is adjusted so that a constant pressure is always maintained in the sealed container 6. Further, the sealed container 6 can be maintained at a predetermined constant temperature inside the sealed container 6 by the temperature controller 13.
4) The upper mold holding part 17 to which the mold 116 is fixed is moved downward where the resin molded body 101 is located, the resin molded body 101 is pressed, the PMMA constituting the surface layer resin member 102 is deformed, and the mold 116 The processed pattern is transferred to the transfer surface 115.
5) Open the pressure reducing valve 12 and reduce the high-pressure carbon dioxide in the sealed container 6 to atmospheric pressure, then raise the upper mold holding part 17 and take out the resin molded product 104 to which the pattern is transferred.

  The pattern of the transfer surface 115 of the mold 116 used in this embodiment is an L & S pattern having an opening width of 350 nm and a height of 175 nm. Further, as described above, the resin molded body 101 has a two-layer laminated structure of PMMA and COP, and uses a laminate of PMMA having a thickness of 0.5 mm on a COP having a thickness of 5 mm. The processing conditions were a carbon dioxide pressure of 10 MPa, a temperature of 40 ° C., a pressing force of 5 MPa, a dissolution time of 1 minute, and a decompression time of 10 seconds. It has been experimentally confirmed in advance that carbon dioxide hardly diffuses into COP under the conditions of 40 ° C., 10 MPa, and dissolution time of 1 minute. Further, as a comparative example, transfer using PMMA alone was also performed. In this example, all steps from pressure increase to pressure reduction and mold release are performed at a constant temperature of 40 ° C., and neither temperature increase nor temperature decrease is performed.

FIG. 3 is a diagram showing a result of shape evaluation by AFM, and FIG. 3A shows a measurement result of a transfer surface of a resin molded product 104 composed of a two-layer laminated structure of PMMA and COP in the present invention. FIG. 3B is a diagram showing the measurement result of the transfer surface of the single PMMA, and FIG. 3C is a diagram showing the measurement result of the transfer surface when the dissolution time of carbon dioxide is 5 minutes or longer with the single PMMA. .
As can be seen from FIG. 3 (a), the resin molded product 104 having a two-layer laminated structure of PMMA and COP in the present invention transfers almost 100% of the pattern formed on the transfer surface 115 of the mold 116. I understand that. On the other hand, as shown in FIG. 3B, it can be seen that in the case of a single PMMA, the transfer rate is 10% or less and hardly transferred. However, by setting the dissolution time to 5 minutes or longer, the pattern formed on the transfer surface 115 of the mold 116 was finally transferred almost 100% even with PMMA alone (FIG. 3C).
The reason for the low transfer rate of PMMA alone is that the infiltration of carbon dioxide diffuses into the resin, so it takes time to satisfy the dissolved amount of carbon dioxide necessary for resin plasticization even at the surface layer. Because. On the other hand, in the present invention, since diffusion does not proceed at the boundary between PMMA constituting the surface resin member 102 and COP constituting the base resin member 103, only the PMMA constituting the surface resin member 102 in a very short time. The required amount of carbon dioxide can be dissolved selectively.

  Further, when carbon dioxide is dissolved with PMMA alone over a period of 5 minutes and transferred almost 100%, bubbles are generated inside the resin when the pressure is rapidly reduced to discharge carbon dioxide from the resin. This is a result of the carbon dioxide dissolved in the resin becoming insoluble and the phase separation of the resin. In order to prevent foaming, it was necessary to reduce the pressure slowly over 10 minutes. On the other hand, in the case of the resin molded product 104 composed of the two-layer laminated structure according to the present invention, since the carbon dioxide is selectively dissolved only in the thin surface resin member 102 composed of PMMA, the resin phase-separates. Since carbon dioxide is previously discharged from the resin, the occurrence of foaming as described above does not occur even if the pressure is reduced in a short time.

As described above, in the present invention, by utilizing the plasticizing effect of carbon dioxide dissolved in the resin, a fine uneven pattern can be accurately formed on the resin surface at a constant temperature without increasing the mold temperature. Can be transferred well. Furthermore, since only the surface layer resin member 102 can be selectively impregnated with carbon dioxide, it is not necessary to accurately control the impregnation time, the impregnation pressure, the impregnation temperature, etc., and the time for dissolving and discharging carbon dioxide is shortened. In addition to improving the productivity and processing stability, it is also possible to suppress the generation of bubbles during decompression.
The thickness of the surface resin member 102 layer is preferably thinner from the viewpoint of shortening the molding cycle and suppressing the occurrence of foaming, but in the base resin member 103 layer, since plasticization of the resin does not proceed, as described above, By making the thickness at least larger than the height of the fine uneven pattern formed on the transfer surface 115 of the mold 116, the finally required uneven pattern can be transferred reliably.

  Further, as described above, since the resin molded body 101 prepared in advance can obtain a desired shape (transfer the desired shape) by pressing in a carbon dioxide atmosphere, a fine pattern is formed. Of course, it may be a nearly final shape that has a shape error with the final shape, so the resin molded body must be made by a very inexpensive method such as the two-color molding described above. Can do.

FIG. 4 is a diagram illustrating a configuration of the resin molded body 201 according to the present embodiment.
Here, the surface resin member 202 is made of PMMA which is a thermoplastic resin, the base resin member 203 is made of a polycarbonate resin (hereinafter referred to as PC) which is a thermoplastic resin, and further, the surface resin member and the base resin. A resin molded body 201, which is a three-layered resin laminate in which an ultraviolet curable resin (hereinafter referred to as UV resin), which is one of photocurable resins, is laminated as an intermediate resin member 206 between the members.

Although the manufacturing method of the resin molding 201 is not limited as in Example 1, in this example, a PC member constituting the base resin member 203 having a thickness of 5 mm is prepared in advance by injection molding. A UV resin constituting the intermediate resin member 206 is spin coated with a thickness of 50 μm on the upper surface, and a PMMA film with a thickness of 100 μm constituting the surface resin member 202 is further laminated thereon, and ultraviolet rays are applied from the upper surface while pressing. Irradiation was performed to cure the UV resin, and at the same time, PMMA constituting the surface resin member 202 and PC constituting the base resin member 203 were integrated.
The transfer was performed using the resin molded product processing apparatus shown in FIG. The pattern of the transfer surface 215 of the mold 216 used in this example is an L & S pattern having an opening width of 2 μm and a height of 1 μm. The processing conditions were the same as in Example 1 except that the pressure of carbon dioxide was 10 MPa, the temperature was 40 ° C., and the pressing force was 5 MPa. The dissolution time and the decompression time were 30 seconds and 10 seconds, respectively.

FIG. 5 is a diagram showing a result of shape evaluation of the resin molded product 204 after pattern transfer by AFM. Even in a resin molded product having a three-layer laminated structure of the surface layer resin member 202, the base resin member 203, and the intermediate resin member 206 in this embodiment, the pattern formed on the transfer surface 215 of the mold 216 is almost 100. % Transfer.
In this embodiment, the UV resin is used as the intermediate resin member 206, as well as the surface resin member 202 and the base resin member 203 can be more firmly adhered to each other. This is because carbon dioxide is hardly dissolved as compared with the thermoplastic resin, so that carbon dioxide can be selectively dissolved only in PMMA. As a result, as in this embodiment, the fine pattern can be transferred in a very short time such as a dissolution time of 30 seconds, and of course, no foaming occurs even if rapid decompression is performed.

There is no problem even if the base resin member 203 is made of UV resin and has a two-layer structure with the surface resin member 202 made of PMMA as in Example 1, but a thick molded product is made of UV resin. It is difficult. By adopting a three-layer structure as in this embodiment, it is possible to deal with thick molded products.
In addition, since the diffusion of carbon dioxide is blocked by the UV resin constituting the intermediate resin member 206 and does not diffuse into the base resin member 203, the same PMMA as the surface resin member may be used as the base resin member 203. no problem. The intermediate resin member 206 is not limited to a UV resin, and a resin such as a thermoplastic resin may be used as long as it is a resin member having a slower carbon dioxide diffusion rate than the resin member constituting the surface resin member 202. . Further, the intermediate resin member may have a laminated structure including two or more types of resin members.

FIG. 6 is a diagram illustrating the configuration of the resin molded body 301 according to the present example, where (a) is a plan view and (b) is an XX cross-sectional view.
Here, the base resin member 303 is made of diethylene glycol bisallyl carbonate (hereinafter referred to as CR-39), which is a thermosetting resin, and PMMA, which is a thermoplastic resin, is applied to the front and back surfaces of the base resin member 303. What was laminated as 302 was prepared. In this embodiment, the transfer surface 315 of the mold 316 is not a fine pattern, but an optical mirror surface is processed, and the optical mirror surface is transferred to the resin molded body 301 with high accuracy. Here, the surface of the resin molded body 301 prepared in advance does not need to be an optical mirror surface, and the shape error may be large. Therefore, the resin molded body 301 can be easily manufactured at low cost without any special device. Can be produced. However, in this case, the thickness of the surface resin member 302 layer is made thicker than the shape error between the transfer surface 315 of the mold 316 and the surface of the resin molded body 301. Accordingly, the shape of the transfer surface 315 of the mold 316 can be reliably transferred to the base resin member 303 even if carbon dioxide is not dissolved and plasticized.
In this embodiment, the method for manufacturing the resin molded body 301 is not limited. However, in this embodiment, as shown in FIG. 6, the uneven thickness of 3 mm to 8 mm, which is prepared in advance by transfer molding. A round lens-shaped base resin member 303 having a shape was manufactured using CR-39. Next, PMMA was molded and integrated on both sides of CR-39 constituting the base resin member 303 by injection molding to form a surface resin member 302 layer.

FIG. 7 is a schematic cross-sectional view of a resin molded product processing apparatus used in an example of the present invention.
The basic configuration is the same as that of the resin molded product processing apparatus of FIG. However, in this embodiment, since it is necessary to transfer both sides of the resin molded body 301, the lower mold holding part 14 and the upper mold holding part 17 can be moved together, and the resin molded body 301 is a ring-shaped holding member. 18 can be held hollow.
The result of transfer under the same processing conditions as in Example 2 is shown in FIG. Here, the shape error from the shape of the transfer surface 315 of the mold 316 is shown for the resin molded body 301 before transfer and the resin molded product 304 after transfer. In the resin molded body 301, a large shape error occurs where there is a difference in thickness between the central portion and the end portion. However, in the resin molded product 304 after transfer, the shape error is corrected, and the transfer surface 315 of the mold 316 is corrected. Could be transferred with high accuracy.

The present invention can be applied not only to transfer to a fine concavo-convex pattern, but also to transfer of an optical mirror surface with high accuracy as in this embodiment. In particular, when molding a lens having an uneven thickness that varies depending on the location as in the present embodiment, pressure and temperature are unevenly distributed depending on the location, so that it is difficult to ensure high precision shape accuracy. As in this example, the surface resin member is laminated on the surface of the base resin member, and carbon dioxide is selectively dissolved and plasticized only in the surface resin member so as to compensate for the shape error of the base resin member. The surface resin member is deformed, and high-accuracy surface transfer can be realized. Further, since only the surface resin member is selectively plasticized without increasing or decreasing the temperature, the processing time is very short.
In this embodiment, a thermosetting resin is used as the base resin member, but the present invention is not limited to this, and a thermoplastic resin or an ultraviolet curable resin is used as in the first and second embodiments. You can also. However, in the case of a thermosetting resin, it is easy to process a thick shape like a thermoplastic resin, and hardly dissolves carbon dioxide like an ultraviolet curable resin, resulting in only a surface layer resin member. Carbon dioxide can be reliably dissolved and plasticized.
As described above, the present invention described so far is not limited to the resins that can be used and those used in the examples, and various modifications can be made without departing from the scope of the invention.

It is a figure which shows the structure of resin used in Example 1, (a) is a figure which shows the resin molding before pattern transfer, (b) is a figure which shows the resin molded product after pattern transfer. It is the cross-sectional schematic of the resin molded product processing apparatus used in Example 1. FIG. It is a figure which shows the result of having performed shape evaluation by AFM, (a) is a figure which shows the transfer surface measurement result of the resin molded product comprised from the two-layer laminated structure of PMMA and COP in Example 1, (b). The figure which shows the transfer surface measurement result in a PMMA single-piece | unit, (c) is a figure which shows the transfer surface measurement result when the melt | dissolution time of a carbon dioxide is made into 5 minutes or more in the PMMA single-piece | unit. It is a figure which shows the structure of the resin molding concerning Example 2. FIG. It is a figure which shows the result of having performed shape evaluation by AFM about the resin molded product concerning Example 2. FIG. It is a figure which shows the structure of the resin molding concerning Example 3, (a) is a top view, (b) is XX sectional drawing. It is the cross-sectional schematic of the resin molded product processing apparatus used in Example 3. FIG. It is a figure which shows the result of having performed shape evaluation by AFM about the resin molded product concerning Example 3. FIG.

Explanation of symbols

  101, 201, 301 ... resin molded body, 102, 202, 302 ... surface layer resin member, 103, 203, 303 ... base resin member, 104, 204, 304 ... resin molded product, 115, 215, 315 ... transfer surface, 116, 216, 316 ... mold, 105 ... uneven pattern, 206 ... intermediate resin member, 6 ... sealed container, 7 ... gas supply pipe, 8 ... gas discharge pipe, 9 ... pressure booster, 10 ... carbon dioxide cylinder, 11 DESCRIPTION OF SYMBOLS ... Supply valve, 12 ... Pressure reducing valve, 13 ... Temperature controller, 14 ... Lower mold holding part, 17 ... Upper mold holding part, 18 ... Holding member

Claims (13)

In the resin molded body used in the method of manufacturing a resin molded product, which presses the transfer surface of the mold onto the surface of the resin molded body impregnated with carbon dioxide, and transfers the pattern of the transfer surface,
The resin molded body has a laminated structure composed of at least two layers of resin members, and has different diffusion rates of carbon dioxide in the resin members when the temperature and pressure are at the same conditions. Molded body.   The resin molded body includes a surface layer resin member pressed against a mold transfer surface, and a base resin member laminated on a back surface of the surface layer resin member. The resin molded article according to claim 1, wherein a diffusion rate of carbon dioxide in the resin member is slower than a diffusion rate of carbon dioxide in the surface resin member.   Between the surface resin member and the base resin member, a layer of an intermediate resin member made of a material different from the surface resin member and the base resin member is provided. The resin molded body according to claim 1, wherein a diffusion rate of carbon dioxide in the intermediate resin member is slower than a diffusion rate in the surface resin member.   The resin molded body according to any one of claims 1 to 3, wherein the base resin member is processed into a substantially final shape in advance.   The resin molded body according to any one of claims 1 to 4, wherein all of the resin members constituting the resin molded body are made of a thermoplastic resin material.   The resin molded body according to any one of claims 1 to 4, wherein the resin member constituting the resin molded body is made of a thermoplastic resin material or a thermosetting resin material.   The resin molded body according to any one of claims 1 to 4, wherein the resin member constituting the resin molded body is made of a thermoplastic resin material or a photocurable resin material. A step of impregnating a resin molded body with carbon dioxide, and a step of pressing a transfer surface of a mold against the surface of the resin molded body to transfer a pattern of the transfer surface to the surface of the resin molded body. In the manufacturing method,
The method for producing a resin molded product, wherein the resin molded product is the resin molded product according to any one of claims 1 to 7.   The step of impregnating the resin molded body with carbon dioxide and the step of pressing the transfer surface of the mold against the surface of the resin molded body are equal to or lower than the softening temperature of the surface layer resin member of the resin molded body before impregnating carbon dioxide. The method for producing a resin molded product according to claim 8, wherein the method is performed.   The step of impregnating the resin molded body with carbon dioxide and the step of pressing the transfer surface of the mold against the surface of the resin molded body are equal to or lower than the softening temperature of the surface layer resin member of the resin molded body before impregnating carbon dioxide. The method for producing a resin molded product according to claim 8 or 9, wherein the method is carried out at a constant temperature.   The method for producing a resin molded product according to any one of claims 8 to 10, wherein a fine uneven pattern is formed on a transfer surface of the mold.   The thickness of the surface layer resin member before pressing the transfer surface of the mold against the surface of the resin molded body is at least thicker than the height of the fine uneven pattern formed on the mold transfer surface. Item 12. A method for producing a resin molded article according to Item 11.   The thickness of the surface resin member before pressing the transfer surface of the mold against the surface of the resin molded body is a thickness that is equal to or greater than the shape error between the base resin member that has been processed into a substantially final shape in advance and the final shape. The method for producing a resin molded product according to claim 12, comprising:

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