JP2019072975A - Mold, method of manufacturing mold, resin molding apparatus and method of molding molded article - Google Patents

Abstract

To provide a mold capable of shortening a molding cycle as compared with a conventional heat insulation mold while forming a fine shape such as a concavo-convex shape with high precision on the surface of a resin molded product, method of manufacturing the mold, and furthermore resin molding apparatus provided with the mold and molding method of a molded article using the resin molding apparatus.SOLUTION: The mold of the present invention has a heat insulating layer having a thermal conductivity of 100°C of less than 10 W/m*K, a metallic mold base material having a thermal conductivity of 100°C of 10 to 70 W/m*K, and a thermally conductive layer having a thermal conductivity of 100°C of more than 70 W/m*K between the heat insulation layer and the metal mold base material, and the heat conductive layer is provided at a position in contact with the lower interface of the heat insulating layer, or at a position of 0.1 mm or less from the lower interface with the heat insulating layer, with a thickness of 0.01 to 5.00 mm.SELECTED DRAWING: Figure 1

Description

  The present invention is used, for example, in resin molding of optical elements, precision parts, etc., and a mold capable of forming a fine surface asperity pattern on a resin molded product and capable of shortening a molding cycle The present invention relates to a method of manufacturing a mold, a resin molding apparatus including the mold, and a molding method of a molded product performed using the resin molding apparatus.

  As products such as optical disks such as CDs and DVDs, optical lenses, optical elements, optical elements such as mirrors and light guide plates, or precision parts, molded articles made of synthetic resin are widely known, but these optical elements and precision parts With the miniaturization, high functionalization, etc. of the etc., the molding technology which can shape | mold the molded article which has a fine and highly precise surface shape conventionally is desired. Further, in recent years, even for transparent display plates, precision parts and the like in which the transfer surface has a large area, finer and higher precision than in the past have been required in terms of surface shape and precision.

  The resin injection molding technology conventionally uses a mold made of a metal material such as steel. When using such a metal mold to injection mold an optical element or precision part having a submicron to 1 mm fine shape, the heat possessed by the molten resin is rapidly transferred to the mold at the moment of being injected into the mold. The resin surface in contact with the cavity or core mold is rapidly cooled and solidifies. Therefore, sufficient mold transferability can not be obtained in the pressure holding process which is a shape transfer process after injecting the resin, and there is a problem that a fine and highly accurate surface shape can not be obtained.

  In order to improve the mold transferability, methods such as increasing the injection pressure at injection molding or increasing the injection speed have been taken, but there is a limit to improve the transferability and it is a sufficient measure. It is the present condition that there is not. Moreover, in order to delay the rapid cooling and solidification of the resin surface in contact with the cavity type or core type, it is possible to improve the transferability by setting the temperature of the mold high and prolonging the cooling time. However, in that case, there is a problem that the molding cycle becomes long and the mass productivity is greatly reduced. Furthermore, although it has been considered to adopt an injection compression method in which compression molding is added to injection molding, the molding cycle becomes longer, the molding apparatus becomes somewhat complicated, and skill in adjusting molding conditions is required. In addition, it is poor in versatility because stress is easily generated in a molded product by the compression process.

  As a method of solving such technical problems, a heat insulating layer is provided on the mold surface, and the temperature of the resin filled in the mold in the injection process is maintained at a high temperature until the pressure holding process which is the subsequent shape transfer process. A number of methods have been proposed to improve the mold transferability. The mold used in this method is generally called a heat insulation mold, and as the heat insulation layer, for example, a polyimide resin or a ceramic is used.

  However, in the injection molding method using the heat insulation mold, there are some technical problems if the heat insulation layer is provided on the mold surface, and methods for solving these technical problems have been proposed. For example, in order to solve the problem that the heat of the heat-melted resin in the vicinity of the heat insulating layer causes local deviation to cause temperature non-uniformity and birefringence occurs in the molded optical component, as described in Patent Document The molding apparatus disclosed in 1 discloses a molding apparatus capable of quickly dispersing heat and eliminating temperature non-uniformity by providing a high thermal conductivity base material on the back side of the heat insulation layer. Further, a mold having a similar configuration and structure is disclosed in Patent Document 2 as an adiabatic cavity type.

  According to Patent Document 3, in order to obtain a heat insulating mold excellent in durability which can endure use under high pressure and high impact property, between a metal mold base material and a metal film constituting a molding surface In a mold having a heat insulation layer, a heat insulation mold having a heat conduction layer having a thermal conductivity of 100 W / m · K or more between the heat insulation layer and the metal film is disclosed. The heat conductive layer used here generates a stress due to the thermal expansion difference generated by the local transfer of the thermal energy of the molten resin injected at high pressure, so the adhesion between the metal film and the thermal insulation layer caused by the thermal expansion difference. Used for the purpose of preventing the deterioration of Further, also in Patent Document 4, a mold having a configuration similar to that of Patent Document 3, that is, a surface layer and a lower surface layer having a thermal conductivity of 60 W / m · k or more in order from the transfer portion of the surface layer. There is disclosed a molding die comprising a heat insulating layer having a thermal conductivity of 30 W / m · k or less and a die body. It is described that the molding die described in Patent Document 4 exerts an effect of being able to reduce the non-uniformity of the temperature distribution in the molded product at the time of molding.

  Furthermore, as a heat insulation metal mold which can improve durability, Patent Document 5 is also laminated in the order of a protective layer, a heat insulation layer and a mold base, and the thickness of the cavity region is greater than the thickness of the region other than the cavity region. Reduced thermal insulation molds are disclosed.

JP, 2013-75457, A WO 2007/129673 JP, 2015-74221, A International Publication No. 2013/146985 JP, 2013-244644, A

  When forming a fine surface asperity pattern using a heat insulating mold in resin molding of optical elements or precision parts, not only excellent mold transferability and high precision surface shape are realized, but mass productivity improvement is achieved. Therefore, shortening of the molding cycle is strongly demanded. Since the heat insulation mold can slightly lower the mold temperature or the molding pressure as compared with the conventional molding mold not using it, as described in the above-mentioned Patent Document 1, for shortening the molding cycle It has some effect on

  However, in the configuration of the heat insulating mold disclosed in the Patent Documents 1 and 2, the characteristics of the heat insulating mold are maintained sufficiently such that heat is instantaneously held and then the heat conduction or transmission is delayed by performing cooling. It was difficult to utilize it. This is because the high thermal conductivity base material provided directly on the back side of the thermal insulation layer has a large heat capacity, so the effect of heat conduction or transmission by the high thermal conductivity base material is greater, and the heat of the molten resin is instantaneously generated in the thermal insulation layer. It does not hold well, it is because it does not fully perform the function as a heat insulation layer. As a result, although the molding cycle can be shortened, there are cases in which it is not possible to form a fine surface shape with high accuracy due to the decrease in mold transferability, the occurrence of thermal stress and the like. This problem does not appear notably in a minute optical element such as a lens as described in the patent document 1, for example, but an optical disc which is molded using a large (large capacity) high thermal conductivity base material, Large-area optical elements such as a light guide plate and a display plate have become major technical issues.

  In addition, the heat insulation mold disclosed in the Patent Document 3 can be provided between the heat insulation layer and the metal film in order to reduce the problem caused by the heat insulation layer that is the local transfer of the thermal energy of the molten resin injected under high pressure. The purpose of the present invention is to provide a thermal conduction layer to instantaneously redistribute heat energy in the horizontal direction of the heat insulation mold. It can be said that the mold disclosed in the Patent Document 4 is also made for the same purpose. However, both molds have only the same effect as the conventional heat insulation mold on heat conduction or heat transfer in the vertical direction (vertical direction), and the effect of shortening the molding cycle more than before can be expected. It was not.

  Similarly, the heat insulation mold disclosed in Patent Document 5 is not proposed to shorten the molding cycle, and the technical problem of shortening the molding cycle compared to the conventional heat insulation mold is entirely It was not recognized.

The present invention has been made to solve such problems, and in the heat insulation mold provided with a heat conduction layer, by adopting a configuration and a structure different from those disclosed in the Patent Documents 1 to 5, A mold capable of shortening a molding cycle as compared to a conventional heat insulation mold while forming a fine shape such as a concavo-convex shape on the surface of a resin molded product with high accuracy, and a method of manufacturing the mold, An object of the present invention is to provide a resin molding apparatus provided with the mold and a molding method of a molded product performed using the resin molding apparatus.

The present inventor adopts a configuration having a heat insulating layer, a metal mold base material, and a heat conductive layer between the heat insulating layer and the metal mold base material, and the respective thermal conductivity and thickness By defining within the predetermined range, it has been found that the above-mentioned problems can be solved, and the present invention has been made.

That is, the constitution of the present invention is as follows.
[1] The present invention is a thermal insulating layer having a thermal conductivity of 100 ° C. of less than 10 W / m · K, a metallic mold base material having a thermal conductivity of 100 ° C. of 10 to 70 W / m · K, A mold having a heat conduction layer having a heat conductivity of more than 70 W / m · K at 100 ° C. between the heat insulation layer and the metal mold base material, wherein the heat conduction layer is a lower boundary surface of the heat insulation layer. The mold is provided with a thickness of 0.01 to 5.00 mm at a position where it abuts or at a position of 0.1 mm or less from the lower boundary surface with the heat insulating layer.
[2] In the present invention, the thermal conductivity at 100 ° C. is 5 W / m · K or less, and the thickness is 0.01 mm to 2.00 mm in the heat insulating layer, and the thermal conductivity at 100 ° C. in the thermal conductive layer Is 150 W / m · K or more, and the thickness is 0.01 to 5.00 mm, and in the metal base material, the thermal conductivity at 100 ° C. is 10 to 70 W / m · K, and the thickness exceeds 10 mm. The mold according to the above [1] is provided.
[3] In the present invention, the heat conduction layer is in a position between the heat insulation layer and the metallic mold base material and in contact with the boundary surface of the heat insulation layer, or the heat insulation layer and the heat conduction The mold according to the above [1] or [2], which is provided at a position of 0.1 mm or less from the lower boundary surface of the heat insulating layer via the bonding layer formed between the layers. provide.
[4] The present invention is characterized in that, in the thermally conductive layer, the thickness in the region of the forming space (cavity) is thinner than the thickness outside the region of the cavity. Provide a mold according to one of the claims.
[5] The present invention is characterized in that, in the heat insulating layer, the thickness in the region of the forming space (cavity) is thicker than the thickness outside the region of the cavity. Providing a mold as described in one section.
[6] The present invention provides the mold according to any one of the above [1] to [5], which has a surface protective layer on the transfer surface side of the surface layer of the molded article.
[7] The mold according to the above [6], wherein the surface protective layer has an outermost surface layer made of a plated film or a diamond-like carbon film on the transfer surface side of the molded article surface layer. I will provide a.
[8] The present invention provides the mold according to any one of the above [1] to [7], wherein the heat conductive layer is formed by physical vapor deposition, chemical vapor deposition, plating, brazing. A method of manufacturing a mold is provided, which is formed on the surface of the metal base material by using at least one of attaching, bolting and spraying.
[9] The present invention is a resin molding apparatus including a mold clamping unit having a mold and an injection unit, wherein the mold is a mold according to any one of the above [1] to [7]. Or a mold obtained by the method of manufacturing a mold according to the above [8].
[10] The present invention provides a method of molding a resin molded product, which comprises performing resin injection molding or resin injection compression molding using the resin molding apparatus described in [9].

  The mold of the present invention adopts a configuration having a heat insulating layer, a metal mold base material, and a heat conduction layer between the heat insulation layer and the metal mold base material, and the respective thermal conductivity and By defining the thickness within a predetermined range, the conduction or transfer of heat from the molten resin to the metal mold base material is sufficiently performed so that the function as a heat insulating layer capable of holding heat instantaneously is sufficiently developed. It can be optimized. Therefore, the molding cycle can be shortened as compared with the conventional heat insulation mold while forming a fine surface shape with high precision not only in a small size but also in a large area resin molded product. Also, by adopting a configuration in which the thickness of at least one of the heat insulating layer and the heat conducting layer is different in the region of the forming space (cavity) and outside the region of the cavity, the difference in thickness of these layers is utilized. Thus, the function of the heat insulation mold can be finely adjusted. Therefore, the degree of freedom in mold design can be increased when shortening the molding cycle. Furthermore, the mold of the present invention can improve the durability of the mold by providing a surface protective layer on the surface side, that is, on the heat insulating layer.

  According to the method of manufacturing a mold of the present invention, the heat conduction layer is formed of metal using metal vapor deposition, chemical vapor deposition, plating, brazing, bolting and / or thermal spraying. By forming a slightly thicker layer on the surface of the base material, the effect of heat conduction or transmission by the heat conduction layer can be enhanced while maintaining the function of the heat insulation layer, so that the molding cycle can be further shortened. become.

  In addition, by applying the mold of the present invention to a resin molding apparatus, a resin molding apparatus is provided which is optimum for resin molding of optical elements, precision parts and the like for which high precision surface shape is required, and which is excellent in mass productivity. can do. And it becomes possible to provide the molding method of the resin molded product which has the high external appearance which formed the fine surface shape with high precision using the resin molding apparatus of this invention.

It is the cross-sectional schematic which shows the metal mold | die of this invention typically. It is the cross-sectional schematic which shows typically the modification of the metal mold | die of this invention. It is a schematic sectional drawing which shows typically another modification of the metal mold | die of this invention from which a cavity area | region becomes convex shape. It is a figure which shows the example of the resin molding apparatus of this invention. FIG. 2 is a view showing a cross-sectional structure of a mold used in a simulation of Example 1; FIG. 6 is a view showing temperature measurement points on the surface of a molded product in a simulation of Example 1; FIG. 2 is a view showing a cooling curve of a molded product obtained by the simulation of Example 1; FIG. 7 is a view showing a method of measuring the amount of warpage of a molded product in Example 2. FIG. 7 is a view showing the relationship between the cooling time and the amount of warpage of a molded product in Example 2.

  FIG. 1 schematically shows a mold of the present invention. In the mold of the present invention, from the viewpoint of heat conductivity or heat conductivity, the heat insulation layer, the heat conduction layer, and the metal mold base material are basically laminated in order from the transfer surface side of the resin molded article surface layer Although it has a structure, as shown to (a) and (b) of FIG. 1, the structure which has a surface protective layer practically is employ | adopted.

  The mold 1 shown in FIG. 1 (a) is laminated in the order of the surface protection layer 2, the heat insulation layer 3, the heat conduction layer 4 and the metal mold base material 5 from the transfer surface side of the resin molded article surface layer. The heat conductive layer 4 disposed under the heat insulating layer 3 is provided in contact with the heat insulating layer 3 in a state of contact. Further, the mold 6 shown in (b) of FIG. 1 is based on the structure of the mold 1 shown in (b) of FIG. 1 and further includes a bonding layer 7 between the heat insulation layer 3 and the heat conduction layer 4. It has a structure provided. The bonding layer 7 is mainly provided to improve the bonding between the heat insulating layer 3 and the heat conducting layer 4. Even if the bonding between the heat insulating layer 3 and the heat conducting layer 4 is a weak combination, the bonding property of both can be improved by the bonding layer 7, so the structure of the mold 6 is the heat conducting layer 3 and the heat conducting layer 4. It has the advantage of broadening the range of choices of applicable materials.

  The mold of the present invention not only adopts a combination of the heat insulating layer 3, the heat conducting layer 4, and the metal mold base material 5, but the heat insulating layer 3 instantaneously holds the heat from the molten resin at the time of molding. In order to be able to do so, it is necessary to define the thermal conductivity of each layer constituting the mold within a predetermined range. Therefore, the thermal insulation layer 3 whose thermal conductivity at 100 ° C. is less than 10 W / m · K, the metallic mold base material 5 whose thermal conductivity at 100 ° C. is 10 to 70 W / m · K, and the thermal insulation layer 3 The metal mold base material 5 has a thermally conductive layer 4 whose thermal conductivity at 100 ° C. exceeds 70 W / m · K. Furthermore, in order to shorten the molding cycle, it is necessary to rapidly conduct or transfer the heat instantaneously held by the heat insulating layer 3 to the metal mold base material 5, so the thermal conductivity point of view Therefore, the thickness of the heat conduction layer 4 needs to be set to 0.01 to 5.00 mm. By defining the thermal conductivity of each layer and the thickness of the thermal conductive layer 4 in the above range, the heat conduction or transfer from the molten resin to the metal mold base material 5 can be easily adjusted, so a fine surface shape can be obtained. The forming cycle can be shortened as compared with the conventional heat insulation mold while forming the with high accuracy.

  In the present invention, when the thermal conductivity (value of 100 ° C.) of the heat insulating layer 3 is 10 W / m · K or more, the function as the heat insulating layer can not be sufficiently obtained. Further, when the thermal conductivity (value of 100 ° C.) of the metal mold base material 5 is less than 10 W / m · K, a sufficient cooling effect can not be obtained. Conversely, if the thermal conductivity (100 ° C. value) of the metal mold base material 5 becomes too large to exceed 70 W / m · K, the large heat capacity accelerates the conduction or transfer of heat, so the molten resin Heat is not held instantaneously in the insulation layer. As a result, the function of the heat insulating layer provided in the mold is significantly reduced, and even if the heat insulating layer 4 is provided, it becomes difficult to form a fine surface shape with high accuracy. This tendency becomes more pronounced as the resin molded product has a larger area. On the other hand, the heat conduction layer 4 interposed between the heat insulating layer 3 and the metal mold base material 5 has a thermal conductivity of the metal mold base material 5 in the above-mentioned range, so 70 W / m ··· at 100 ° C. It needs to have a thermal conductivity greater than K.

  In addition, when the thickness of the heat conduction layer 4 is less than 0.01 mm, the effect of heat conduction or contact transmission can hardly be obtained. On the other hand, if the thickness is more than 5.00 mm, the heat capacity of the heat conduction layer 4 becomes large, and a metal mold of high thermal conductivity having a thermal conductivity of 70 W / m · K or more at 100 ° C. The same function and action as the direct contact of the base material to the heat insulating layer is provided. As a result, as in the heat insulating molds described in Patent Documents 1 and 2, the function of the heat insulating layer provided in the mold is significantly reduced, and the heat of the molten resin is not instantaneously held by the heat insulating layer.

  The mold 1 shown in FIG. 1A is provided at a position where the heat conduction layer 4 abuts on the lower boundary surface of the heat insulation layer 3, so the heat of the molten resin held by the heat insulation layer 3 Conduct or transmit quickly. On the other hand, as in the case of the mold 6 shown in (b) of FIG. 1, in the case of adopting a structure including the bonding layer 7 between the heat insulating layer 3 and the heat conducting layer 4, the thermal conductivity of the bonding layer 7 is As it is generally lower than the conductive layer 4, reducing the distance between the heat insulating layer 3 and the bonding layer 4 is essential in terms of thermal conductivity. In the present invention, it is necessary to provide at a position of 0.1 mm or less from the lower interface with the heat insulating layer 3. If the heat conduction layer 4 is disposed more than 0.1 mm from the lower interface with the heat insulation layer 3, heat conduction or heat transfer is not rapidly performed, and the effect of shortening the molding cycle is hardly obtained.

  In the present invention, the thermal insulation layer 3 further has a thermal conductivity of 5 W / m · K or less at 100 ° C. and a thickness of 0.01 mm to 2.00 mm, and the thermal conduction layer 4 has a thermal conductivity of 100 ° C. Rate of 150 W / m · K or more, with a thickness of 0.01 to 5.00 mm, metal mold base material 5 has a thermal conductivity of 100 ° C. of 10 to 70 W / m · K, 10 mm It is preferred to have a thickness greater than. The heat insulating layer 3, the heat conductive layer 4 and the metal mold base material 5 are not limited to the thermal conductivity but also defined in thickness within a specific range, so that the molten resin to the metal mold base material 5 It becomes easy to adjust the conduction or transfer of heat, and a great effect can be obtained in the optimization of the conduction or transfer of heat.

  By setting the thermal conductivity of the thermal insulation layer 3 at 100 ° C. to 5 W / m · K or less and setting the thickness to 0.01 mm to 2.00 mm, the heat of the molten resin is instantaneously held by the thermal insulation layer Since the effect is surely obtained, the function as a heat insulating layer is greatly improved. Furthermore, the thermal conductivity of the thermal conductive layer 4 at 100 ° C. is 150 W / m · K or more, the thickness is set to 0.01 to 5.00 mm, and the thermal conductivity of 10 to 70 W / m · K at 100 ° C. By providing the metal mold base material 5 having a degree of contact with the heat conduction layer 4 in a thickness of more than 10 mm, the conduction and transfer of heat instantaneously held in the heat insulation layer are further promoted, and gold The cooling effect of the mold can be enhanced. In this way, both the heat insulation and heat conduction effects can be reliably obtained, so the molding cycle can be significantly shortened compared to the conventional heat insulation mold while forming the fine surface shape of the resin molded product with high accuracy. Can be

  In the mold of the present invention, the thermal conductivity of the heat insulating layer 3, the thermal conductive layer 4, and the metal mold base material 5 has a value of 100 ° C. unless otherwise specified. The mold set during actual injection molding is generally set to a temperature in the range of 60 to 120 ° C. Therefore, in view of the object of the present invention, when defining the thermal conductivity of each layer, the value measured at the mold temperature at the time of injection molding, specifically at 100 ° C. is appropriate. However, the thermal conductivity of copper widely known as a high thermal conductivity metal is 386 W / m · K and 377 W / m · K at values of 20 ° C. and 100 ° C., respectively, and the difference between the two is very small. Similarly, also in aluminum, the values of 20 ° C. and 100 ° C. are 204 W / m · K and 206 W / m · K, respectively, and the difference due to temperature is very small. Therefore, even if the thermal conductivity of each layer is defined as a value at room temperature (specifically, 10 to 30 ° C.), it does not affect the magnitude of the thermal conductivity at all, so the thermal conductivity at 100 ° C. is clear The thermal conductivity at room temperature may be used for combinations of materials that are not

  In the present invention, as shown in FIG. 2, in at least one of the heat insulating layer 3 and the heat conducting layer 4, the thicknesses have different configurations within the region of the molding space (cavity) and outside the region of the cavity. It may be According to the configuration shown in FIG. 2, the heat insulating effect by the heat insulating layer 3 and the effect of heat conduction or transfer by the heat conduction layer 4 are not only the heat conductivity and thickness possessed by each layer but also the inside of the cavity region and the outside of the cavity region. The degree of freedom in mold design can be increased when the molding cycle is further shortened since the thickness can be finely adjusted by changing the thickness of each layer.

  FIG. 2A is a schematic view schematically showing a cross section of the mold 8 having the heat conducting layer 4 formed thinner in the cavity region as compared with the outside of the cavity region. FIG. 2B is a schematic view schematically showing a step surface of the mold 9 having the heat insulating layer 3 formed thicker in the cavity region than outside the cavity region. Further, FIG. 2C is a combination of (a) and (b), in the region of the cavity, the mold 10 having the heat insulating layer 3 and the thin heat conduction layer 4 thicker than outside the region of the cavity. It is the schematic which shows a cross section typically. (A), (b) and (b) of FIG. 2 are only the structural differences of the mold, and the intended function and function are the same.

  In the molds 8, 9, 10 shown in FIG. 2, the heat of the molten resin momentarily held in the heat insulating layer 3 is diffused or transferred rapidly from within the cavity region including the transfer surface of the resin molded article surface layer. A structure in which the thickness of the heat conduction layer 4 located outside the cavity region is made relatively thicker than that of the heat insulation layer 3 in order to accelerate heat conduction or transmission outside the cavity region Have. This creates a difference in the rate of heat transfer or heat transfer between the inside and the outside of the cavity area.

  In the mold shown in FIG. 2, the thicknesses of the heat insulating layer 3 and the heat conducting layer 4 can be changed, for example, as follows. In the case of the mold 8 shown in (a) of FIG. 2, heat is applied onto the metal mold base material 5 having a flat surface having a convex step as a portion corresponding to the cavity area of the mold. The conductive layer 4 is formed. Next, the upper surface of the heat conductive layer 4 is processed into a flat shape so as to have a predetermined thickness by at least one of precision machine grinding and precision machine polishing, and then the heat insulating layer 3 is formed. If necessary, a surface protective layer 2 is further formed on the heat insulating layer 3.

  Further, in the case of the mold 9 shown in FIG. 2 (b), after the heat conduction layer 4 is formed thereon using the flat metal mold base material 5, in the heat conduction layer 4 in the cavity region Processing is performed to a predetermined thickness by at least one of precision machine grinding and precision machine polishing so that the corresponding portion is a flat surface having a concave step. Next, the heat insulating layer 3 is formed on the heat conductive layer 4, and the upper surface of the heat insulating layer 3 is processed into a flat shape with a predetermined thickness by at least one of precision machine grinding and precision machine polishing. If necessary, a surface protective layer 2 is further formed on the heat insulating layer 3. Further, in the case of the mold 10 shown in (c) of FIG. 2, the respective layers can be formed by combining the methods of producing the mold 8 and the mold 9.

  The heat insulation layer 3, the heat conduction layer 4 and the metal mold base material 5 which the molds 8, 9 and 10 shown in FIG. 2 have have thicknesses of 0.01 mm to 2.00 mm and 0.01 to 5.00 mm, respectively. And it is preferable to form so that 10 mm may be exceeded. Moreover, when forming the surface protective layer 2 as needed, the thickness of the surface protective layer 2 is adjusted to such an extent that the function of the heat insulation layer 3 is not largely impaired while improving the durability of the mold.

  FIG. 3 is a schematic cross-sectional view schematically illustrating a mold of the present invention in which the cavity region has a convex shape. In the mold 11 shown in FIG. 3, the thickness of the heat conduction layer 4 located outside the area of the cavity is thicker than in the area of the cavity, and basically the same as the mold 8 shown in FIG. Have the same function and action. Therefore, the heat of the molten resin momentarily held by the heat insulating layer 3 located in the area of the cavity is rapidly transferred to the metal mold base 5 through the thick film heat conduction layer 4 located outside the area of the cavity. Conducted or transmitted. Thus, the molding cycle can be further shortened while maintaining the surface shape of the resin molded product molded in the region of the cavity with high accuracy. Here, the shape formed in the cavity region is not limited to a planar shape and a convex shape as shown in FIGS. 2 and 3, and a mold transfer such as a concave shape or an optical disk, a light guide plate, a display plate, etc. It may have a shape in which many holes, holes or grooves are formed on the surface side. Further, as for the structure of the mold shown in FIG. 3, as in the case of the mold 10 shown in FIG. 2C, the thickness of not only the heat conduction layer 4 but also the heat insulation layer 3 You may change between the outside.

  Next, the material of each layer which comprises the metal mold | die of this invention, its heat conductivity, and the formation method of each layer are demonstrated.

<Adiabatic layer>
The material of the heat insulating layer 3 of the mold of the present invention is, for example, a thermosetting resin such as a polyimide resin, an epoxy resin, a phenol resin, a urea resin, a thermosetting resin such as unsaturated polyester Conductivity: 0.1 to 0.4 W / m · K); Zirconia (thermal conductivity: 3 W / m · K) or alumina (thermal conductivity at 99.7% purity: 29 W / m · K), oxidized Ceramics such as titanium (thermal conductivity in anatase: 8.4 W / m · K), aluminum titanate (thermal conductivity: 1.5 W / m · K); and inorganic oxide glass (thermal conductivity: 0.5) ̃2 W / m · K) and the like. These materials have approximately the same thermal conductivity between room temperature and 100 ° C. The heat resistant resin may contain low thermal conductivity fibers such as inorganic glass fibers and organic fibers. Moreover, the heat insulation layer 3 may have a porous structure, and the space | gap in this porous may have a structure filled with another solid. In the present invention, among these, it is preferable to use a material having a small thermal conductivity of 5 W / m · K or less.

<Heat conduction layer>
The heat conductive layer 4 of the mold of the present invention includes, for example, pure copper (heat conductivity of 100 ° C .: 377 W / m · K), aluminum (heat conductivity of 100 ° C .: 240 W / m · K), magnesium (Thermal conductivity of 100 ° C: 154 W / m · K), Zinc (Thermal conductivity of 100 ° C: 112 W / m · K), Brass (Thermal conductivity of 100 ° C: 128 W / m · K), Nickel ( Thermal conductivity at 100 ° C .: 83 W / m · K) or alloys thereof. In addition, high thermal conductivity noble metals such as gold (thermal conductivity at 100 ° C .: 313 W / m · K) and silver (thermal conductivity at 100 ° C .: 422 W / m · K) or tungsten (thermal conductivity at 100 ° C.) Although metals such as 163 W / m · K) and molybdenum (thermal conductivity at 100 ° C .: 135 W / m · K) or alloys thereof may be used, these metals are preferable in terms of cost, workability, etc. It is necessary to consider when using it. In the present invention, among these, use is made of copper and aluminum having a large thermal conductivity of 150 W / m · K or more, low in cost, easy to handle including workability, and alloys thereof. Is preferred.

  The formation of the heat conduction layer is not limited to a specific method, and any known method can be employed. For example, physical vapor deposition such as sputtering, ion plating, MBE, vacuum evaporation, etc .; chemical vapor deposition such as thermal CND, MOCVD, PF plasma CVD, etc .; plating such as electrolytic plating, electroless plating, etc. Brazing of silver, copper, brass, phosphorous copper, aluminum or the like; mechanical bolting; spraying, etc., using any known method. In the present invention, not only one of these methods but also two or more of these methods may be combined.

  According to the present invention, by forming the conductive layer provided on the surface of the metal base material to be a slightly thick film, it is possible to accelerate the conduction or transfer of heat by the heat conductive layer while maintaining the function of the heat insulating layer. Therefore, the molding cycle can be further shortened. Therefore, as a method of easily forming a thick-film thermally conductive layer in a short time, it is preferable to adopt each method of plating, brazing, bolting and thermal spraying among the above methods. Furthermore, since a uniform thick film can be formed, it is particularly preferable to form the heat conduction layer by electroplating or a plating method combining electroless plating and electrolytic plating. In the case of the plating method, not only a few mm thick film but also a few tens micron thin film can be formed uniformly and easily as compared with other methods in forming the heat conduction layer.

<Metal mold base material>
The metal mold base material 5 of the mold of the present invention only needs to be made of metal, and known or commercially available materials can be used, but as described above, the heat conduction at 100 ° C. It is necessary to use one having a rate of 10 to 70 W / m · K. In the present invention, a single metal such as copper or aluminum, or a material such as a copper alloy or a titanium alloy is not suitable as the metal mold base material 5 because the thermal conductivity is large. Therefore, it is preferable to use an iron-based metal, for example, carbon steel (thermal conductivity at 100 ° C .: 36 to 53 W / m · K), stainless steel (thermal conductivity at 100 ° C .: 13 to 27 W / m · K) , Nickel steel (thermal conductivity at 100 ° C: 10 to 26 W / m · K), nickel chromium steel (thermal conductivity at 100 ° C: 36 W / m · K), silicon steel (thermal conductivity at 100 ° C: 19 to Those used as plastic injection molds such as 42 W / m · K) and chromium steel (thermal conductivity at 100 ° C .: 31 to 45 W / m · K) are preferred. Among them, stainless steel having high strength, high hardness and excellent durability is more preferable.

  The above-mentioned iron-based metal is excellent in hardness and processability and is more versatile than copper, a copper alloy, an aluminum alloy, a copper-beryllium alloy or the like which is a high thermal conductivity metal, so the metal mold of the present invention It is suitable as a metal mold base material 5 used for The metal mold base material 5 may be either a molten material or a sintered material of an iron-based metal.

  The molding surface side of the metal mold base material 5 is formed in either a surface or a curved surface, and may be a reverse of a fine shape to be imparted to the final molded product, It can select suitably according to the shape of the molded article to carry out. For example, in the case of forming the concavo-convex part (protrusion part or groove part), even if a reverse type of a shape to be transferred onto the molding surface or a shape similar thereto is formed in advance on the molding surface side of the metal mold base material 5 Good.

<Bonding layer>
The bonding layer 7 provided in the mold 6 shown in (b) of FIG. 1 is mainly provided to improve the bonding between the heat insulating layer 3 and the heat conducting layer 4, and in particular, it is oxidized and strong. The metal which is easy to form an oxide film on the surface is preferable. For example, titanium (Ti), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), etc. or their alloys are preferable. The thickness of the bonding layer is 0.1 mm or less, preferably 0.01 mm or less, more preferably 0.001 mm (1 μm) or less, from the viewpoint of thermal conductivity. Further, in order to ensure the bonding between the heat insulation layer 3 and the heat conduction layer 4, the thickness of the bonding layer is preferably 0.02 μm or more. Therefore, it is practical to set the thickness of the bonding layer to 0.02 to 1.0 μm in consideration of both the thermal conductivity and the bonding property.

  The formation of the bonding layer 4 is performed by physical vapor deposition (PVD) on the surface of the heat conduction layer. The physical vapor deposition method (PVD method) is suitable for forming a bonding layer of a thin film, and examples thereof include a sputtering method, an ion plating method, an MBE method, and a vacuum evaporation method. The bonding layer may be composed of a single layer or multiple layers.

  The bonding layer 7 shown in (b) of FIG. 1 is provided between the heat insulating layer 3 and the heat conducting layer 4, but in the present invention, the heat conducting layer 4 and the metal mold are used if necessary. Another bonding layer other than the bonding layer 7 may be provided between the base material 5 or between the surface protective layer 2 and the heat insulating layer 3. The bonding layer different from the bonding layer 7 can also be formed by selecting an optimal combination that can improve the bonding property of each layer from the materials and thicknesses exemplified in the bonding layer 7. .

<Surface protective layer>
The mold of the present invention has the surface protective layer 2 because the following effects can be obtained by providing the surface protective layer on the transfer surface side of the molded product as shown in FIG. 1 and FIG. Is practical.
(1) Sufficient transferability can be obtained because the shape of the mold is transferred to the molded body with high accuracy of micron order or less.
(2) Since sufficient transferability can be obtained without increasing the injection pressure or the injection speed, the durability of the mold is improved.
(3) When a heat insulating layer composed of a heat resistant resin or ceramic is used as the transfer surface of a molded product, the surface shape is rough, and fine particles and wear powder are easily generated from constituent components. It can be difficult to produce molded articles with surface formation. In addition, since the thermal insulation layer of the heat resistant resin has a thermal expansion coefficient larger than that of metal, the thermal insulation layer may be easily peeled off from the thermal conduction layer during use, and the mold durability may be low. This technical problem can be solved by the surface protective layer provided on the outermost surface of the mold.

  The surface protective layer 2 can be formed of, for example, a single layer or a multilayer structure of two or more layers by at least one of a metal film and an amorphous diamond carbon film. As a method of forming the metal film, for example, plating methods such as electroplating and electroless plating; chemical vapor deposition methods such as thermal CVD, MOCVD and RF plasma CVD; ion plating method, MBE method, vacuum evaporation method and the like Known thin film forming methods such as physical vapor deposition methods of The amorphous diamond carbon film can be formed, for example, using a carbon target by a magnetron sputtering method or the like.

  The thickness of the surface protective layer 2 needs to be set to an extent that the function of the heat insulating layer 3 is not significantly impaired while improving the durability of the mold, and is preferably 0.1 μm to 1 mm, and more preferably 1 μm to 0. 5 mm is more preferable.

  When the surface protective layer 2 is formed on the mold of the present invention, a relatively thick film of several μm or more can be formed in a short time from the viewpoint of wear resistance and durability, and a fine surface shape with high accuracy. Since it is possible to form a surface having excellent planar smoothness which can be imparted, etc., the most side consisting of a plated film or a diamond like carbon film on the opposite side of the surface in contact with the heat insulation layer, ie the transfer surface side of the resin molded article surface layer. It is preferred to have a surface layer. At this time, in order to further improve the wear resistance of the surface protective layer 2, a fluorine-containing diamond like carbon film may be used as an example of the diamond like carbon film.

  In the mold of the present invention, when the surface protective layer 2 has a single layer structure, a plated film or a diamond like carbon film is formed as a single layer. When the surface protective layer 2 has a multi-layered structure of two or more layers, any of a plated film and a diamond like carbon film is formed on the outermost surface layer. For example, when forming a diamond-like carbon film as the outermost surface layer, Cr, W, etc. are formed between the diamond-like carbon film of the outermost surface layer and the thermal insulation layer 3 in order to improve adhesion to the thermal insulation layer 3. The sputtering underlayer may be formed of Ti, Si or the like. In that case, the surface protective layer 2 can be considered to have a two-layer structure having a sputtering underlayer and a diamondlike carbon film as the outermost layer.

<Resin molding apparatus and molding method of resin molded product>
The mold of the present invention is applied as a mold included in a resin molding apparatus such as an injection molding apparatus or an injection compression molding apparatus used for resin molding of an optical element or a precision part. The example of the injection molding apparatus is shown in FIG. 4 as a resin molding apparatus of this invention. The resin molding apparatus 12 shown in FIG. 4 is roughly divided into a clamping unit and an injection unit. The mold clamping unit performs opening and closing of the mold and ejector (ejector), and basically includes a fixed platen 13, a movable platen 14 and an opening and closing drive device 15. As a method of the mold clamping unit, there are a toggle method and a direct pressure type in which the mold is directly opened and closed by a hydraulic cylinder, and in some cases, a mold clamp is provided in the unit according to the mold clamping method. A mold clamping unit can be used to arrange a mold 16 consisting of a movable mold 16a and a fixed mold 16b between the fixed plate 13 and the movable plate 14 and hold the two molds and clamp them to form them. Make it

  The fixed board 13 is fixed to the center of the support table 17 so as to face the movable board 14, and the pick-up device 18 is provided on the top of the fixed board 13. The takeout device 18 is electrically connected to a device control unit (not shown).

  The injection unit shown in FIG. 4 basically heats and melts the resin and injects it into the mold 16. Basically, the nozzle 19, the heater 20, the cylinder 21, the hopper 22 for injecting the resin, and the injection drive device And 23. Even after the screw (not shown) inside the cylinder 21 is rotated, the resin introduced from the hopper 22 is fixed to the front of the screw (metering portion), and after the stroke corresponding to the required resin amount, the injection is performed. When the resin is flowing in the mold, the moving speed (injection speed) of the screw is controlled, and after the resin is filled, it is controlled by the pressure (holding pressure). Switching from speed control to pressure control is set to switch when a constant screw position or a constant injection pressure is reached.

  The temperature of the mold 16 is controlled by warm water, oil, a heater or the like. The molten resin enters the interior of the mold 16 from the sprues of the mold 16 and is filled into the cavity through the runner gate. Thereafter, through the cooling process, the mold 16 is opened, and the ejector plate of the mold is pushed by the ejector rod (not shown) of the resin molding apparatus 12 to eject the resin molded product. The extruded resin molded product is removed by the removal device 18.

  The resin molding apparatus of the present invention is a mold positioned on the side to which the fine concavo-convex pattern formed on the surface of a resin molded article such as an optical element or a precision part is transferred in the movable mold 16a and the fixed mold 16b of the mold 16. Apply the mold of the present invention at least. When a fine uneven pattern is formed on both side surfaces of a resin molded product, the mold of the present invention is applied to both the movable mold 16a and the fixed mold 16b. As a result, since a fine surface asperity pattern can be formed on a resin molded product with high accuracy by a molding cycle shorter than that of a conventional heat insulation mold, molding of a high appearance molded product can be efficiently performed. .

  As described above, resin injection molding is performed using the resin molding apparatus of the present invention, but even in the case of resin injection compression molding, resin molding can be basically performed according to the same process as in the case of resin injection molding. . In the resin injection compression molding, as in the case of the resin injection molding, holding pressure is performed after the molten resin enters the inside of the mold 16, but the movable mold 16a is fixed during the step of holding pressure. The only difference is that it is moved towards 16b to add a compression step. Resin injection compression molding is a molding method suitable for molding complicated surface pattern shapes, such as aspheric shapes.

  EXAMPLES Hereinafter, examples based on the present invention will be specifically described, but the present invention is not limited by these examples.

Example 1
In order to verify the effect of the present invention, thermal simulation using a finite element method was performed. The simulation software used Moldex3D Vie.R13 (manufactured by Coretech System).

  FIG. 5 shows a cross-sectional structure of a mold used for the simulation. The mold is composed of an upper mold consisting of a metal mold base material 5 and a lower mold consisting of a heat insulating layer 3, a heat conduction layer 4 and a metal mold base material 5 of the same material as the upper mold. The shape of 24 was a flat plate. In the present example, in order to simplify the simulation, calculation was performed on a mold excluding the surface protective layer as shown in FIG. Further, FIG. 6 shows temperature measurement points of molded articles calculated by performing simulation. As shown in FIG. 6, temperature measurement points were set at positions (R30, R59) 30 mm and 59 mm away from the central position of the gate, and the substrate surface temperature at that point was calculated. Table 1 below shows the parameters used for the simulation.

  The result of having performed simulation about the change by the shaping | molding time of the temperature in the point of R30 of the molded article shown in FIG. 6 and R59 is shown in FIG. FIG. 7 shows a cooling curve of the molded article 24. As can be seen from the enlarged view of the portion where the take-out temperature is reached, the mold of the present invention (the product of the present invention) is a conventional mold without a heat conduction layer (conventional mold) In contrast to the product, the temperature of the molded product is lower in the product of the present invention at relatively the same molding time. Table 2 below shows the ratio of the peak temperature at the R30 and R59 points and the time for reaching the removable temperature in the product of the present invention (heat insulation layer + high heat conduction layer) and the conventional product (heat insulation layer only). . Here, as the "extractable temperature", as shown in FIG. 7, a point at which an arbitrary temperature unit is about 2.9 was used as a reference. This temperature unit point is determined to coincide with the temperature at which resin molding can actually be taken out.

  As shown in Table 2, when comparing the product of the present invention with the current product at each point, there is no difference in peak temperature, but the time to reach the removable temperature is 12.0% at R30, R59 It turned out that 7.5% was shortened at the point of. A characteristic feature of the heat insulating mold having the heat insulating layer 3 is that a large rise of a sharp temperature peak is observed because heat transfer is delayed due to a momentary heat retention effect. Therefore, the fact that there is almost no difference in peak temperature between the product of the present invention and the current product means that the effect of the present invention as an insulation die is not reduced compared to the current product. Thus, it was confirmed that the present invention has a high cooling effect while maintaining the characteristics as a heat insulation mold, as compared to the conventional mold having no heat conduction layer.

Comparative Examples 1 and 2
In the cross-sectional structure of the mold shown in FIG. 5, simulation was performed in the same manner as in Example 1 for a mold having no heat insulating layer 3 and no conductive layer 4. This mold is constituted only by the metal mold base 5, and 200 W / m · k simulated to copper metal is used as the thermal conductivity of the metal mold base 5 at 100 ° C. . This simulation example is referred to as Comparative Example 1.

  Moreover, in the parameters of the simulation shown in Table 1, the simulation in which the thermal conductivity of the heat conduction layer 4 and the metal mold base material 5 at 100 ° C. is 200 W / m · k for both as a comparative example 2 is also simulated. Did. Although the mold of Comparative Example 2 has the heat insulation layer 3, the heat conduction layer 4 and the metal mold base material 5 are integrated with the metal mold base material having a high thermal conductivity of 200 W / m · K. It has the following structure. Therefore, it simulates the structure which does not have the heat conduction layer 4 substantially, ie, the structure where the high thermal conductivity copper alloy die base material 5 abuts on the heat insulation layer.

  As a result of simulation, in Comparative Examples 1 and 2, the time to reach the removable temperature was shorter at both R30 and R59 than the product of the present invention shown in FIG. 7 and the conventional product. As compared with the conventional product shown in FIG. 7, the time ratio to the removable temperature was reduced by 25% or more at the point of R30 and 15% or more at the point of R59. On the other hand, when the peak temperature was compared, Comparative Example 1 and Comparative Example 2 both had values of only 60% with respect to the product of the present invention and the conventional product. Further, when the peak temperature and the time for the removable temperature are compared between Comparative Example 1 and Comparative Example 2, almost no difference is seen between the two, and the mold structure of Comparative Example 2 has the heat insulating layer 3. Nevertheless, it was found that the molded product had a cooling curve similar to that of Comparative Example 1. Therefore, the mold of Comparative Example 2 in which the mold base material is made of a material having a high thermal conductivity and quenched by a large heat capacity has a sufficient function as the heat insulating layer 3 to hold the heat of the molten resin instantaneously. It was confirmed that it was not expressed in That is, although the mold of Comparative Example 2 can shorten the cooling time, it has become clear that the advantages of the heat insulation mold such as transferability and high fluidity can not be sufficiently exhibited.

Example 2
Based on the simulation results of Example 1, a molding test using an actual machine was performed. A mold corresponding to the lower mold shown in FIG. 5 was produced as follows.

The method of forming the heat conduction layer is shown below. The heat conductive layer 4 is formed by copper sulfate plating on the metal mold base material 5 (material SUS420J2: thermal conductivity of 100 ° C. = 27 W / m · K) adjusted to HRC 52 by heat treatment. After degreasing with 10% sodium hydroxide, after pickling with 10% hydrochloric acid, plating was performed with a plating solution adjusted to 250 g / L of copper sulfate and 65 g / L of sulfuric acid. The bath temperature was 30 ° C., the sample was placed on the cathode side, pure copper was placed on the anode, and copper was reduced to the cathode at a current density of 10 A / dm ² . Plating was performed for 25 hours to obtain a 530 μm pure copper film on the sample. Furthermore, in order to make the film thickness distribution uniform, the film thickness was adjusted to 500 μm using a surface grinder and a polishing machine.

The method of forming the heat insulation layer 3 on the pure copper surface obtained by copper sulfate plating is shown below. The sample was placed on the cathode electrode in a vacuum chamber, and the gas pressure in the chamber was exhausted to 3 × 10 ⁻³ Pa. Thereafter, using mass flow, argon gas was introduced at a flow rate of 50 sccm, and a DC bias voltage of 1 KV was applied between the anode electrode and the cathode electrode. The plasmatized argon repeatedly collided with the cathode (sample) surface to remove the oxide film and the adsorbed dirt on the surface. Next, 99.99% zirconia was placed on the sputter target, and glow discharge was generated using an RF power supply and a magnetron sputtering apparatus. At this time, argon gas was selected as a gas medium and introduced at 100 sccm using mass flow. The sputtering output was 1500 W, and film formation was performed for 42 hours to obtain a heat insulating layer 3 made of zirconia and having a thickness of 55 μm.

  In order to obtain uniformity of the surface of the heat insulating layer 3 formed by magnetron sputtering, polishing was carried out using diamond abrasive grains with a particle diameter of 1 μm and colloidal silica, and the surface roughness was adjusted to Ra = 20 nm and the heat insulating layer thickness 50 μm. .

  As can be seen from the simulation results of Example 1, the product of the present invention (thermal insulation layer + high thermal conductivity layer) has a shorter time to reach the temperature which can be taken from the peak temperature, as compared with the conventional product (thermal insulation layer only). In this experiment, verification of shortening of the cooling time in actual molding was conducted. When taken out in a state where the resin temperature is not sufficiently lowered, the characteristic that becomes a problem as a molded article is warpage. This is because a deformation called post-shrinkage occurs because the molded product becomes free from the mold in a state where sufficient cooling has not been completed.

  So, in this experiment, the curvature amount with respect to each cooling time was measured, and the boundary value in which the curvature amount enters 100 micrometers or less was calculated as required cooling time. The warpage amount of 100 μm or less is a value generally accepted as the maximum warpage amount of the optical element and the precision part. The basic conditions of the molded article and the molding process used in the experiment were in accordance with the contents shown in Table 1. The amount of warpage of the molded article after molding is as shown in FIG. 8 after installing the molded article on a surface plate so that the warpage is concave, holding one side in the longitudinal direction, and completely installing on the surface plate, Measurement was carried out with a measuring microscope (manufactured by STM7 Olympus) with the height h on the opposite side held down. The relationship between cooling time and warpage is shown in FIG. 9 as an experimental result.

  The relationship between the cooling time and the amount of warpage was approximated plot in the form of a quadratic function as shown in FIG. 9, and the necessary cooling time, that is, the cooling time below 100 μm which is the allowable value of the warpage amount was determined. As a result, while the conventional product (heat insulation layer only) is 2.8 seconds, the product of the present invention (heat insulation layer + high heat conduction layer) is 1.8 seconds, which makes it possible to shorten one second compared to the conventional product. It became. The evaluation results including the reduction rate of the total molding time are summarized in Table 3 below. The molding total time shown in Table 3 is represented by: molding total time = injection time (1.5 seconds) + cooling time.

The samples after molding are of the conventional product (heat insulation layer only) and the product of the present invention (heat insulation layer + high heat conduction layer), and other required quality characteristics (ink mark, stress, transferability, waviness, yellowing) I could not confirm the problem regarding). As described above, according to the product of the present invention, the surface of the resin molded product is made higher by having the heat conduction layer between the heat insulation layer and the metal mold base material, as compared with the conventional product constituted only by the heat insulation layer. It was confirmed that the molding cycle can be shortened while maintaining the appearance.

  In the present embodiment, although the effect of the present invention was verified using a mold which does not form a surface protective layer, for example, a surface protective layer having an outermost surface layer formed of a plated film or a diamond like carbon film It has been confirmed that the same effect as that of this embodiment can be obtained also in the mold formed on the transfer surface side. Therefore, in order to improve the transferability of the surface of the molded article and the mold durability, it is preferable to use the mold of the present invention which has been highly functional by forming the surface protective layer.

  As described above, in the mold of the present invention, the conduction or transfer of heat from the molten resin to the metal mold base material is optimized so that the function as a heat insulating layer capable of holding heat instantaneously is sufficiently expressed. Therefore, the molding cycle can be shortened as compared with the conventional heat insulation mold while forming a fine surface shape with high accuracy not only in a small size but also in a large area resin molded product. Therefore, by applying the mold of the present invention to a resin molding apparatus, a resin molding apparatus is provided which is optimum for resin molding of optical elements, precision parts and the like for which a highly accurate surface shape is required, and which is excellent in mass productivity. In addition, it is possible to establish a molding method of a resin molded product having a high appearance in which a fine surface shape is formed with high accuracy.

1, 6, 7, 8, 9, 10, 11, 16 · · · Mold 2 · · · surface protection layer 3 · · · thermal insulation layer 4 · · · heat conduction layer 5 · · · metal mold base material 12: Resin molding apparatus 13: Fixed board 14: Movable board 15: Opening and closing drive device 17: Support stand 18: Extraction device 19: Nozzle 20: Heater 20: Heater 21 .. Cylinder 22 ... hopper 23 ... injection molding device 24 ... molded article

That is, the constitution of the present invention is as follows.
[1] The present invention is a heat insulating layer having a thermal conductivity of 5 W / m · K or less at 100 ° C. and a thickness of 0.01 mm to 2.00 mm, a thermal conductivity of 10 to 70 W / m at 100 ° C. -A metal mold base material that is K, and a thermal conductivity of 100 ° C. of 150 W / m · K or more and a thickness of 0.01 mm to 5 mm between the heat insulation layer and the metal mold base material . have a heat conductive layer is 300 mm, the heat conducting layer is in a position in which it contacts the lower boundary surface of the heat insulating layer, or 0.1mm following positions from the lower boundary surface between the heat insulating layer, the thickness 0.01 provided in mm ～5.00Mm, and, on a surface thereof opposite to the heat conductive layer and the surface abutting the heat insulating layer, a surface protective layer is not provided, or the surface protective layer is 0 to provide a mold which is characterized that you have provided in contact with the heat insulating layer in a thickness of .1μm~0.5mm .
[2] The present invention is characterized in that the heat conduction layer has a thickness of 0.50 mm to 5.00 mm, and the metal base material has a thickness of more than 10 mm. Provide the mold described.
[3] In the present invention, the heat conduction layer is in a position between the heat insulation layer and the metallic mold base material and in contact with the boundary surface of the heat insulation layer, or the heat insulation layer and the heat conduction The mold according to the above [1] or [2], which is provided at a position of 0.1 mm or less from the lower boundary surface of the heat insulating layer via the bonding layer formed between the layers. provide.
[4] The present invention is characterized in that, in the thermally conductive layer, the thickness in the region of the forming space (cavity) is thinner than the thickness outside the region of the cavity. Provide a mold according to one of the claims.
[5] The present invention is characterized in that, in the heat insulating layer, the thickness in the region of the forming space (cavity) is thicker than the thickness outside the region of the cavity. Providing a mold as described in one section.
[6] The present invention has a surface protective layer having a thickness of 0.1 μm to 0.5 mm on the transfer surface side of the surface layer molded article surface layer, any of the above-mentioned [1] to [5] Provide a mold according to one of the claims.
[7] The present invention is characterized in that the surface protective layer has an outermost surface layer composed of a plated film or a diamond-like carbon film on the transfer surface side of the surface layer of the molded article . Providing a mold according to any one of the preceding claims.
[8] The present invention provides the mold according to any one of the above [1] to [7], wherein the heat conductive layer is formed by physical vapor deposition, chemical vapor deposition, plating, brazing. A method of manufacturing a mold is provided, which is formed on the surface of the metal base material by using at least one of attaching, bolting and spraying.
[9] The present invention is a resin molding apparatus comprising a mold clamping unit having a mold and injection unit, mold according to any one of the mold is the [1] to [7] resin molding apparatus which is a result mold obtained.
[10] The present invention provides a method of molding a resin molded product, which comprises performing resin injection molding or resin injection compression molding using the resin molding apparatus described in [9].
[Effect of the invention]

According to the present invention, the heat conduction layer provided on the surface of the metal base material is formed in a slightly thick film to accelerate the conduction or transfer of heat by the heat conduction layer while maintaining the function of the heat insulation layer. Since it is possible, the molding cycle can be further shortened. Therefore, as a method of easily forming a thick-film thermally conductive layer in a short time, it is preferable to adopt each method of plating, brazing, bolting and thermal spraying among the above methods. Furthermore, since a uniform thick film can be formed, it is particularly preferable to form the heat conduction layer by electroplating or a plating method combining electroless plating and electrolytic plating. In the case of the plating method, not only a few mm thick film but also a few tens micron thin film can be formed uniformly and easily as compared with other methods in forming the heat conduction layer.

Claims (10)

  Thermal insulation layer having a thermal conductivity of less than 10 W / m · K at 100 ° C., metallic mold base material having a thermal conductivity of 100 ° C. of 10 to 70 W / m · K, and the thermal insulating layer and the metal gold A mold having a heat conductive layer having a thermal conductivity of more than 70 W / m · K at 100 ° C. between the mold base materials, wherein the heat conductive layer is in contact with the lower interface of the heat insulating layer, or A mold having a thickness of 0.01 to 5.00 mm provided at a position of 0.1 mm or less from the lower interface with the heat insulating layer.   The thermal insulation layer has a thermal conductivity of 5 W / m · K or less at 100 ° C. and a thickness of 0.01 mm to 2.00 mm, and the thermal conductive layer has a thermal conductivity of 150 W / m · K at 100 ° C. Above, it has a thickness of 0.01 to 5.00 mm, and the metal base material is characterized in that the thermal conductivity at 100 ° C. is 10 to 70 W / m · K, and the thickness exceeds 10 mm. The mold according to claim 1.   The heat conductive layer is formed between the heat insulating layer and the metallic mold base material at a position in contact with the boundary surface of the heat insulating layer, or between the heat insulating layer and the heat conductive layer. The mold according to claim 1 or 2, which is provided at a position of 0.1 mm or less from the lower boundary surface of the heat insulating layer via the bonding layer.   The mold according to any one of claims 1 to 3, wherein the heat conductive layer has a thickness in the region of the molding space (cavity) thinner than a thickness outside the region of the cavity.   The mold according to any one of claims 1 to 3, wherein the heat insulating layer has a thickness in the region of the molding space (cavity) greater than a thickness outside the region of the cavity.   The mold according to any one of claims 1 to 5, wherein a surface protective layer is provided on the transfer surface side of the surface layer of the molded article.   The mold according to claim 6, wherein the surface protective layer has an outermost surface layer made of a plating film or a diamond like carbon film on the transfer surface side of the surface layer of the molded article.   The mold according to any one of claims 1 to 7, wherein the heat conductive layer is at least any of physical vapor deposition, chemical vapor deposition, plating, brazing, bolting and spraying. A method of manufacturing a mold, which is formed on the surface of the metal base material using the method of   A resin molding apparatus comprising a mold clamping unit having a mold and an injection unit, wherein the mold is the mold according to any one of claims 1 to 7, or the mold according to claim 8. What is claimed is: 1. A resin molding apparatus characterized by being a mold obtained by the manufacturing method of   A method of molding a resin molded product, wherein resin injection molding or resin injection compression molding is performed using the resin molding apparatus according to claim 9.

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