WO2009084615A1

WO2009084615A1 - Die member, method for manufacturing the die member and method for forming light controlling member by using the die member

Info

Publication number: WO2009084615A1
Application number: PCT/JP2008/073687
Authority: WO
Inventors: Ichiro Matsuzaki; Yoshinori Osanai; Takumi Yagi; Masakatsu Sugasaki
Original assignee: Kuraray Co., Ltd.
Priority date: 2007-12-27
Filing date: 2008-12-26
Publication date: 2009-07-09
Also published as: KR101473680B1; KR20100096190A; CN101909847B; TWI457219B; JPWO2009084615A1; KR20120127539A; CN101909847A; KR101261258B1; TW200936347A; JP5610770B2

Abstract

Provided is a die member, which is to be used for manufacturing a light controlling member by an injection molding method wherein a die is used, and can be attached and detached to and from the die. The die member is provided with a metal thin board main body having a die surface and a thickness of 0.2mm or more but not more than 0.6mm; a low heat conductivity member, which is arranged on a surface facing the die surface and a thickness of 0.1mm or more but not more than 0.5mm, and is integrated with the thin board main body; and a reinforcing member integrally arranged on the rear surface of the low heat conductivity member.

Description

Mold member, method for manufacturing the same, and method for forming light control member using the same

The present invention relates to a mold member used for manufacturing a light control member by an injection molding method, a manufacturing method thereof, and a molding method of a light control member using the same.

An injection molding method (including an injection compression molding method) in which a heat-fluidized resin material is injected into a cavity in a mold, cooled and solidified in the mold, and then the mold is opened to take out a molded product. As a processing method of a resin material containing a thermoplastic resin, it is widely used as one of molding methods that can easily improve production speed and automate molding.

However, a cooling solidified layer may be formed on the surface of the molten resin injected and filled into the cavity in a general injection molding method. Such a cooling and solidifying layer hinders transferability of fine unevenness of a molded product, and causes generation of a weld mark, a cold mark, a flow mark, and the like.

The present applicant has already proposed an example of solving the problem of such an injection molding method (for example, Patent Document 1). In the method of molding a resin molded product described in Patent Document 1, a thin plate member or a mold member is mounted on one surface of a mold cavity. The thin plate member is composed of a metal thin plate main body having a mold surface that forms one surface of a cavity, and a low thermal conductivity member made of a polyimide film disposed on the back surface of the thin plate main body. Here, in a mold equipped with this thin plate body, when a thermoplastic resin having a temperature higher than the transfer start temperature is introduced into the cavity, the mold is cooled by the mold and lowered to a temperature lower than the transfer start temperature. The heat capacity of the thin plate body is set so that the thermoplastic resin near the surface of the mold rises again to a temperature exceeding the transfer start temperature.

Using such a mold, a thermoplastic resin having a temperature equal to or higher than the transfer start temperature is introduced into the mold cavity held at a temperature equal to or lower than the transfer start temperature. The thermoplastic resin introduced into the cavity portion is cooled on the cavity surface of the mold and temporarily falls to a temperature not higher than the transfer start temperature. However, since one surface of the cavity (mold surface) has a set heat capacity, the mold The thermoplastic resin in contact with the surface can rise again to a temperature exceeding the transfer start temperature.

According to such a molding method of a resin molded product, the formation of a cooled solidified layer on the surface of the molten resin injected and filled in the cavity can be reduced, and the transferability is improved. In addition, the occurrence of weld marks, cold marks, flow marks, etc. is reduced. Thereby, the molding method of such a resin molded product is suitable for production of a light control member that controls light such as a light guide plate and a lens sheet.

According to the molding method of a resin molded product described in Patent Document 1, a resin molded product having a different fine shape on the surface is replaced with the same metal by exchanging thin plate bodies with different concave and convex patterns or mirror surface patterns engraved on the mold surface. It has the advantage that it can be manufactured using a mold.

However, when a resin molded product is manufactured over a long period of time or the thin plate body is repeatedly replaced, distortion may be observed on the surface of the resin molded product. When this cause was examined, it was estimated that it might be caused by wrinkles and creases generated in the polyimide film disposed or adhered to the back surface of the thin plate main body.

That is, the polyimide film disposed or adhered to the back surface of the thin plate main body may be wrinkled or broken when the thin plate main body is replaced. Here, in the thin plate main body proposed in Patent Document 1, the temperature of the thermoplastic resin in contact with the mold surface put into the cavity once falls below the transfer start temperature, but again rises above the transfer start temperature. The heat capacity must be set to be a predetermined capacity. Therefore, the thickness of the thin plate main body is limited to a predetermined heat capacity, and is generally as thin as 1 mm or less (for example, within a range of about 0.3 mm to 0.6 mm). As a result, a new problem has been found that when wrinkles or creases occur in the polyimide film, it becomes impossible to avoid the occurrence of distortion on the mold surface as the molding surface of the thin plate body.
Japanese Patent No. 3686251 (FIGS. 6, 8 and paragraph 0038)

Accordingly, an object of the present invention is a mold member having a replaceable thin plate body used for manufacturing a thin plate-like light control member by injection molding, and can be stably produced even when used for a long period of time. The object is to provide a mold member.

A mold member according to an embodiment of the present invention is a mold member that is used for manufacturing a light control member by an injection molding method using a mold, and that can be attached to and detached from the mold, and includes a mold surface. A metal thin plate body having a thickness of 0.2 mm or more and 0.6 mm or less, and a thickness of 0.1 mm or more and 0.5 mm or less disposed on a surface facing the mold surface, A low thermal conductivity member integrated with the main body; and a reinforcing material provided integrally on the back surface of the low thermal conductivity member.

It is a figure which shows the mounting state to the metal mold | die of the thin-plate member in one Example of this invention, Fig.1 (a) is a side view seen from the side surface, FIG.1 (b) is the plane seen from the cavity surface side. FIG. It is a figure explaining the structure of the thin-plate member in one Example of this invention by a cross section. It is a figure explaining the structure of the thin-plate member in one Example of this invention by a cross section. It is a figure which shows the result of having measured the relationship between the temperature of a polymethylmethacrylate resin, and a longitudinal elastic modulus. It is a figure which shows the conditions of the simulation about a light-guide plate. It is a figure which shows the result of having calculated | required the relationship between the time (second) after injection | emission, and the temperature of the surface which touches the metal mold | die of a polymethylmethacrylate resin by the simulation by unsteady heat conduction analysis using MARC. It is a figure which shows the result of having calculated | required the relationship between the time (second) after injection | emission, and the temperature of the surface which touches the metal mold | die of a polymethylmethacrylate resin by the simulation by unsteady heat conduction analysis using MARC.

Hereinafter, the best mode for carrying out an embodiment of the present invention will be described. In the following drawings, for convenience of explanation, the vertical and horizontal scales of each part are illustrated by schematic diagrams that are randomly changed.

An example of a schematic view of a mold member according to the present invention is shown in FIGS. Here, FIG. 1 illustrates a state where the mold member 10 is mounted on the mold. In FIG. 2 or FIG. 3, the details of the mold member mounted thereon are described.
A mold member or thin plate member 10 according to an embodiment of the present invention is a mold member 10 that is used in the manufacture of a light control member by an injection molding method using a mold and is detachable from the mold. And a metal thin plate body 20 having a mold surface or cavity surface 20a and having a thickness of 0.2 mm or more and 0.6 mm or less, and a surface opposed to the mold surface 20a integrated with the thin plate body. And a low thermal conductivity member 30 having a thickness of 0.1 mm or more and 0.5 mm or less, and a reinforcing member 40 provided integrally on the back surface of the low thermal conductivity member 30.
In addition, the mold member or the thin plate member 10 according to an embodiment of the present invention is a mold member that is used for manufacturing a light control member by an injection molding method using a mold and can be attached to and detached from the mold. And a metal thin plate body having a mold surface or cavity surface 20a and having a thickness in the range of 0.3 mm or more and 0.6 mm or less, and the thin plate body integrated with the thin plate body on the surface facing the mold surface. And a low thermal conductivity member having a thickness in the range of 0.1 mm or more and 0.3 mm or less.

Here, the outline of the present invention will be described. In order to solve the conventional problems, the present inventor tried to consider in detail the cause of distortion generated on the molding surface of the thin plate body. The problem that has been regarded as a problem in the past is to avoid the case where the size of the resin molded product is small if the thin plate body is replaced with great care when placing a film on the back of the thin plate body. Is possible. However, with the recent increase in screen size of liquid crystal display devices, various types of resin molded products for light control used therein have been required. For example, in a light control member such as a light guide plate or a diffusion plate disposed over the entire display surface of a liquid crystal display device, one long side may be larger than 1 m.

In a mold for manufacturing such a large resin molded product for light control, handling is difficult to work without causing wrinkles or creases in the polyimide film disposed on the back surface, More and more skill is required, which is a new important issue. Further, such a problem has been recognized as a new problem that is not regarded as important at all in a resin molded product such as an optical disk substrate which is a resin molded product having a diameter of about 20 cm to 30 cm at most.

According to the analysis of the present inventor, even when a film as a low thermal conductivity member is adhered to the back surface of the thin plate main body, it may be caused by the heat history, pressure holding history, etc. of the molding cycle. It was thought that peeling occurred in the part. That is, even if an adhesive that is sufficiently bonded to a metal is used normally, the heat history and pressure holding history due to high holding pressure at a high temperature generated in a molding cycle of about 60 seconds are Reflecting the difference in expansion, linear expansion coefficient between the thin plate body and the adhesive, or the linear expansion coefficient between the adhesive and the low thermal conductivity member more than expected, as a result, some unexpected peeling occurred. It was thought that there was.

Therefore, the present inventor integrates the thin plate main body and the low thermal conductivity member disposed on the back surface thereof from the recognition that a structure that does not cause even a part of the peeling of the bonded portion is necessary. However, I thought that it might be the most important to solve the above-mentioned problems.

As a method for integrating such a thin plate main body and a low thermal conductivity member, a low thermal conductivity member is integrated on the back of the thin plate main body using a thermosetting heat-resistant adhesive, or a low heat is applied to the back of the thin plate main body. It has been recognized that the above-described problems can be solved by disposing a reinforcing material via a conductivity member to form a sandwich structure with a low thermal conductivity member that is expected to break.

Here, in order to integrate the thin plate body and the low thermal conductivity member using an adhesive, the adhesive to be used is heat resistance, pressure resistance, shear resistance, heat deterioration resistance (no thermal decomposition, no foaming) It has been found by the present inventors that it is important to maintain various characteristics such as

That is, the heat resistance needs to withstand the resin temperature filled at a high temperature as an injection molding condition, and to prevent thermal decomposition or foaming. Further, the pressure resistance is necessary to withstand a high holding pressure for maintaining high transferability of fine unevenness. In addition, the shear resistance needs to withstand repeated thermal histories at high and normal temperatures in accordance with the injection molding cycle. If any of these conditions is satisfied and the low thermal conductivity member is disposed on the back surface of the thin plate body, the low thermal conductivity member may be thermally decomposed, foamed, or partially peeled, etc. It is possible to prevent distortion from occurring.

That is, in one embodiment of the present invention, a heat-fluidized resin material is injected into a cavity in a mold, solidified or cured while maintaining a high pressure in the mold, and then the mold is opened to form a thin plate. A mold member used in the manufacture of a light control member by an injection molding method for taking out a resin molded product formed into a shape, wherein at least one of the two large opposing surfaces of the thin plate-like shape transmits light. The mold member is used as an injection surface to be injected, and the mold member has a mold surface that forms one surface of the cavity and has a thickness of 0.2 mm or more and 0.6 mm or less. A thickness of 0.1 mm or more and 0.5 mm or less disposed on the back surface of the thin plate main body, which is a surface facing the mold surface, and a metal thin plate main body within a range of 3 mm to 0.6 mm, Preferably 0.1 mm or more. a die having at least a low thermal conductivity member within a range of mm or less, the interface between the thin plate main body and the low thermal conductivity member being integrated, and detachable as a cavity surface of the die It may be a member.

If the thin plate body and the low thermal conductivity member are integrated with a thermosetting heat-resistant adhesive, the occurrence of peeling of the low thermal conductivity member can be further suppressed. Here, it is preferable that the heat resistant adhesive does not generate a cured byproduct.

In addition, if a reinforcing material is integrated on the back surface of the low thermal conductivity member, even if peeling occurs in a part of the low thermal conductivity member, the thin plate main body is not distorted. Further, such a reinforcing material can improve the operability of the thin plate member, and facilitates the mounting and demounting operations of the thin plate body on the cavity surface of the mold.

In a preferable mold member of the present invention, the low thermal conductivity member includes a first heat-resistant adhesive layer having a low thermal conductivity within a range of 10 μm to 200 μm and a low heat within a range of 10 μm to 200 μm. A conductive layer and a second heat-resistant adhesive layer having a low thermal conductivity in a range of 10 μm or more and 200 μm or less are provided.

Further, in the mold member lined with the above reinforcing material, the thin plate body and the reinforcing material will not be warped if they are the same material, but even when different materials are selected, the difference in mutual linear expansion coefficient is reduced. In addition, by setting the thickness of the reinforcing material to the minimum necessary thickness, it is possible to reduce warpage due to a temperature difference generated in the molding cycle process.

Such a mold can be manufactured by, for example, using a heat-resistant adhesive layer (first heat-resistant adhesive layer, the second heat-resistant adhesive layer) and a low heat conductive layer as a film. .

For example, when integrating the interface between the thin plate main body and the low thermal conductivity member using a film-like adhesive as a thermosetting heat-resistant adhesive, the integration process is performed as the thin plate main body and the low thermal conductive layer. A step including a step of integrating the thin plate body and the low thermal conductive film through at least two steps of a first step of laminating the heat resistant film and a second step of thermosetting at a temperature higher than the first step is performed. Thus, a mold member preferable for use in the present invention can be manufactured.

By adopting such conditions, it is possible to provide a mold member having a sufficient degree of cross-linking, hardness and pressure resistance that does not cause variation in thickness, and resistance to shearing of the resin. Due to this, sufficient heat deterioration resistance is ensured that the bonded part will not be decomposed even if it is repeatedly used under severe conditions of the molding cycle (heat reception from high-temperature fluid molten resin used for injection molding). Can be secured. Here, the laminating conditions and the curing conditions can be appropriately determined in consideration of the resin material to be used, manufacturing equipment, and the like.

If a mold equipped with the above-described mold member is used, the mold member is composed of a mold in which a thermoplastic resin having a temperature equal to or higher than the transfer start temperature is held at a temperature equal to or lower than the transfer start temperature. After the thermoplastic resin in the vicinity of the mold surface, which has been introduced into the cavity and cooled by the mold to a temperature lower than the transfer start temperature, is filled with the thermoplastic resin, the transfer start temperature is again measured. The heat capacity of the surface portion on the cavity portion side is set so as to increase to a temperature exceeding. As a result, if a light control member that uses at least one of the two opposing large plate-like surfaces as an emission surface to emit light is molded using such a mold, it is stable even during long-term use. A light control member can be manufactured. Further, since this mold member can be exchanged, if a plurality of mold members having different concavo-convex patterns on the mold surface are prepared, it can be used for manufacturing a small amount of brand-name light control members.

Examples of the light control member molded in this way include a light guide plate, a lens sheet, a light diffusion plate, and the like. A fine uneven pattern is formed on one surface of these light control members, and the fine unevenness reproduces the uneven surface stamped on the surface of the mold member.

In the mold member 10 shown in FIG. 2, the metal thin plate body 20 having a mold surface 20a that forms one surface of the cavity and the back surface 20b of the thin plate body 20 that is a surface facing the mold surface 20a are disposed. And a low thermal conductivity member 30. The low thermal conductivity member 30 is composed of a first heat resistant adhesive layer 32 composed of a heat-resistant thermosetting adhesive and a low thermal conductivity member layer 31, and the low thermal conductivity member layer 31 is the first. The thin plate main body 20 is integrated with the heat resistant adhesive layer 32.

In the mold member 10 of one embodiment of the present invention, the thicknesses of the thin plate body 20 and the low thermal conductivity member 30 are set to be a predetermined value from the relationship of the heat capacity and the like. The thickness of the thin plate main body 20 has a characteristic that it is extremely thin within a range of 0.2 mm to 0.6 mm, preferably within a range of 0.3 mm to 0.6 mm.

On the other hand, the thickness of the low thermal conductivity member 30 is not particularly limited as long as it can be insulated. However, if it is too thin, the heat insulating property is not sufficient, and it is necessary to take a long molding cycle. In some cases, it is difficult to manufacture light control parts stably in the course of a severe molding cycle. In general, it is desirable to make the thickness thin within a range that can ensure sufficient heat insulation, and is usually set within a range of 0.1 mm to 0.5 mm, preferably within a range of 0.1 mm to 0.3 mm. As with the thin plate body, it is extremely thin.

As shown in FIG. 2, when the low thermal conductivity member 30 is composed of the first heat-resistant adhesive layer 32 and the low thermal conductivity member layer 31, each thickness is, for example, 10 μm or more and 200 μm or less. A combination of a first heat-resistant adhesive layer having a low thermal conductivity within a range and a low thermal conductive layer having a thickness of 10 μm or more and 200 μm or less. Also in this case, the total thickness in which the first heat-resistant adhesive layer and the low thermal conductivity member layer 31 are integrated has a feature that it is extremely thin within a range of 0.1 mm to 0.3 mm.

The thermosetting adhesive used in one embodiment of the present invention belongs to a resin material and has a significantly lower thermal conductivity than a metal material. Therefore, the thin layer (thermosetting adhesive layer 32) formed of the thermosetting adhesive corresponds to the low thermal conductivity member defined in one embodiment of the present invention. Thereby, the low heat conductivity member 30 is comprised by the heat resistant adhesive bond layer 32 and the low heat conductivity member layer 31 which are shown in FIG.

Here, as the low thermal conductivity member used in one embodiment of the present invention, a general plastic material can be widely applied, but it is necessary to have excellent heat resistance and pressure resistance. Examples of such a material include polyimide and polyamideimide. However, if the material has sufficient thickness and durability, the low thermal conductivity member can be constituted only by the thermosetting adhesive itself. However, since it is difficult to obtain a single material with a thickness sufficient to ensure heat insulation, it is difficult to obtain a heat resistant film with a thin plate body. The structure of FIG. 2 integrated through a thermosetting adhesive is preferable.

As shown in FIG. 1, such a thin plate member 10 is formed by forming a recess in the back plate 50 of the mold 100 by a depth corresponding to the thickness of the thin plate member 10, and forming the mold surface of the thin plate member 10 in the recess. It is attached so that 20a is on the surface side (cavity surface side).

The mounting of the thin plate member 10 in the recess is not particularly limited as long as it can be removed (detached). In simple terms, it can be mounted if the surface of the recess is kept sticky or adsorbable. Moreover, you may comprise so that attachment and detachment | desorption can be performed with a fitting structure.

In such a thin plate member 10, since the low thermal conductivity member 30 and the thin plate main body 20 are integrated, the handling operation when the mold member 10 is mounted on the back plate 50 is facilitated, and a long time is required. Even after the molding cycle, there is no distortion on the surface of the molded product.

Next, the reason why distortion of the molded product can be eliminated by integrating the low thermal conductivity member 30 with the thermosetting adhesive interposed therebetween and the thin plate body 20 will be described.

Although the details of the reason why the thermosetting adhesive is particularly excellent in the integration of the low thermal conductivity member 30 and the thin plate body 20 are unknown, the present inventor presumes the reason as follows.

That is, as a low thermal conductivity member, since a heat resistance is generally required, a polyimide-based member is preferred and adopted. However, a plastic material such as polyimide has a significantly larger linear expansion coefficient than the metal material constituting the thin plate body. Therefore, if the polyimide film is bonded to the thin plate main body with a normal pressure-sensitive adhesive or the like, it is difficult to withstand repeated molding cycles because the polyimide film is displaced due to the difference in thermal (linear) expansion coefficient. In addition, in the configuration in which a thin layer of a precursor of a heat-resistant film material such as polyimide or polyamideimide is applied to the back surface of the thin plate main body by a coating method or the like in an uncured form, the molding conditions employed in the present invention can be secured. It is difficult to ensure sufficient heat insulation. That is, it is difficult to secure a necessary thickness by the coating method.

In addition, when a polyimide film or polyamide-imide film is bonded with a normal heat-resistant adhesive, due to the difference in thermal expansion coefficient between the adhesive and the metal thin plate material, some peeling occurs during long-term use. Is inevitable. The cause of the peeling is unknown, but according to the careful observation of the present inventor, it can be pointed out that it may be caused by the generation of a very small amount of gas (decomposed product) generated from the adhesive.

On the other hand, when using a thermosetting adhesive having heat resistance as an adhesive, by setting a sufficient heating temperature and heating time as curing conditions, without generating a very small amount of gas. It can be presumed that this contributes greatly as a factor in eliminating the occurrence of distortion in the molded product.

Preferred heat-resistant thermosetting adhesives for the present invention include, for example, heat-resistant rubber (for example, nitrile rubber) and thermosetting adhesive that has strong adhesive strength as a structural adhesive and the like and has heat resistance. And a mixture with an agent (for example, a phenol resin). By blending such a heat-resistant rubber material with a heat-resistant thermosetting adhesive having excellent adhesive strength, the adhesive properties can be greatly changed. Nitrile rubber systems in particular have a high polarity CN group in the molecule, and therefore give high peel strength and toughness. This gives shear resistance to the thermosetting adhesive.

The adhesive is, for example, a phenol-based dehydration-condensation adhesive, a mixture of an imide-based, phenol-based, or acrylic rubber-based resin, and these self-crosslinking adhesives or addition-reactive adhesives are used. May be.
An example of such a preferred adhesive is a thermally active film (trade name Tessa HAF) provided by TESA. This tessa HAF (thermally active film) is provided in the form of a film made mainly of nitrile rubber and phenol resin and protected on both sides by release paper. By peeling the double-sided release paper, it has light tackiness, so it can be temporarily bonded to other thin plate materials. In addition, this thermoactive film is softened at a low temperature of about 80 ° C. to 100 ° C., for example, and exhibits thermoreversible adhesiveness. Further, it can be dehydrated and cross-linked by an irreversible chemical reaction at a high temperature exceeding 120 ° C., for example, within a range of about 120 ° C. to 220 ° C., and can exert a strong bonding force.

That is, high toughness and high strength are expressed by dehydration crosslinking between the rubber component and the strong adhesive component. In addition, this crosslinking reaction is irreversible, and it exhibits a heat resistance of 150 ° C. or higher and a high adhesive strength of 12 N / mm ² or higher by crosslinking under high pressure with sufficient curing temperature and curing time. And exhibit very good waving characteristics. Due to the excellent waving characteristics, volatile components are not substantially generated under the conditions of the molding cycle according to the present invention.

Here, the preferable conditions for producing the mold member according to the present invention are the first step of laminating the thin plate body 20 and the heat-resistant film as the low thermal conductive layer 31 at a low temperature, and the heat at a temperature higher than the first step. The thin plate body 20 and the low thermal conductive film are bonded to each other through two steps including the second step of curing. Here, it is more preferable to perform the first step and the second step under pressure.

The first step (lamination step) and the second step (curing step) are performed under pressure for a sufficient time (for example, 0.1 MPa, 6 hours) to compress the thermally active film under high pressure. In this state, it is thermally crosslinked. By bonding and integrating under high temperature and high pressure, even in the molding cycle in which the present invention is repeated with high temperature and high pressure (holding pressure), deformation of the thermally active film as an adhesive layer is suppressed, As a result, an extremely strong and durable bonding force can be exhibited at the interface between the thin plate body 20 and the low thermal conductivity member layer 31.

Here, for example, when a thermoactive film (Tesa HAF film) is used as a preferable material in the present invention, the curing time and curing temperature recommended by the film provider are, for example, 130 ° C. to 220 ° C. for about 10 minutes to 30 minutes. Within these ranges, a cured film having physical properties in the range of about 490 N / cm ² to 2530 N / cm ² (rate: 300 mm / min, temperature: 23 ° C.) is obtained. It is explained that it can.

On the other hand, the curing conditions proposed in the present invention are at least 130 ° C. or higher for 1 hour or longer, preferably 2 hours or longer, usually about 3 hours. As a result, a fully crosslinked cured film is obtained, and as a result, there is no variation in thickness under high temperature and high pressure injection molding cycle conditions according to an embodiment of the present invention. Shear resistance against shearing can be ensured.
(Modification of mold member 10)
Next, in the mold member 10 of FIG. 3, the metal thin plate body 20 having the mold surface 20a that forms one surface of the cavity and the back surface 20b of the thin plate body 20 that is the surface facing the mold surface 20a are arranged. The low thermal conductivity member 30 is provided, and a reinforcing member 40 disposed on the back surface of the low thermal conductivity member 30.

The low thermal conductivity member 30 includes a first heat resistant adhesive layer 32 composed of a heat resistant thermosetting adhesive, a low thermal conductivity member layer 31, and a heat resistant thermosetting adhesive. 2, the low thermal conductivity member layer 31 is integrated with the thin plate main body 20 via the first heat resistant adhesive layer 32, and the low thermal conductivity member layer 31 is the second thermal conductivity member layer 31. The heat-resistant adhesive layer 33 is integrated with a reinforcing member 40 disposed on the back surface.

Here, since the thermosetting adhesive has a remarkably small thermal conductivity compared to metal, the thin layers (thermosetting adhesive layers 32 and 33) formed by this thermosetting adhesive and the low thermal conductivity member are used. The layer 31 constitutes the low thermal conductivity member 30.

Accordingly, in the mold member 10 of FIG. 3, the low thermal conductivity member is bonded by the thermosetting adhesive, whereby the thin plate main body 20 and the low thermal conductivity member 30 and the interface between the thin plate main body 20 and the reinforcing material 40. Are integrated.

In the mold member 10, like the mold member shown in FIG. 2, the thickness of the thin plate body 20 is set to be a predetermined value from the relationship of the heat capacity and the like, and is usually 0.3 mm or more and 0.6 mm or less. It is characterized by being extremely thin within the range.

The low thermal conductivity member 30 includes, for example, a low heat conductive first heat-resistant adhesive layer having a thickness of 10 μm or more and 200 μm or less, a low heat conductive layer having a thickness of 10 μm or more and 200 μm or less, and a thickness of 10 μm. The combination with the low heat conductive second heat-resistant adhesive layer within the range of 200 μm or less, and the total thickness of these layers integrated is within the range of 0.1 mm or more and 0.3 mm or less. It is very thin.

Similarly, as shown in FIG. 1, such a thin plate member 10 is carved into the back plate 50 of the mold 100 by a depth corresponding to the thickness of the thin plate member 10, so that the mold of the thin plate member 10 is formed in the recess. The surface 20a can be mounted with the surface side (cavity surface side). In such a thin plate member 10, the reinforcing member 40 is further provided on the back surface as compared with the mold member 10 of FIG. 2, whereby the handling operation of the mold member 10 is further facilitated, and repeated mounting and demounting are facilitated. .

In addition, as long as it has sufficient thickness as the reinforcing material 40, the part of the back plate 50 which supports the back surface of the mold member 10 may be omitted. The typical example of such an example is the same as or equivalent to the case where the thin plate member 10 is bonded to the cavity surface of the nested mold. As confirmed from Example 2 described later, in this case as well, it is desirable to use a thermosetting adhesive having heat resistance as the adhesive. Generally, a low thermal conductivity member is softer than a metal material due to plastic or the like. Therefore, it may be assumed that distortion occurs in the mold surface 20a of the thin plate body due to the selection of the adhesive.

Here, the reinforcing material 40 is not particularly limited as long as it has a reinforcing action, but a stainless steel material can be used in consideration of economy.

Here, as the reinforcing member 40, the same material as that of the thin plate body 20 may be used. However, the thin plate body 20 generally constituting the cavity surface is nickel or chrome formed by a technique such as electroplating or cutting. Relatively expensive materials such as chrome plating are applied to materials such as copper and brass that can withstand processing. Therefore, it is not economical to use these expensive thin plate materials as the reinforcing material. In particular, when using a large mold member as desired in the present invention, it is necessary to consider the economy.

However, when selecting a reinforcing material at random, if the reinforcing material is selected at random, warpage that occurs during the adhesive manufacturing process under high temperature and high pressure becomes a problem for large mold members. It turns out. That is, when a heat-resistant thermosetting adhesive is used, crosslinking is performed under high temperature and high pressure, but there is a large difference in thermal expansion coefficient between the reinforcing material and the thin main body when allowed to cool after completion of curing. In some cases, the obtained thin plate member (mold member 10) may be warped.

For example, a linear expansion coefficient of ^{17.times.10.sup.-6} / .degree. C. via a thermally active film manufactured by Tessa as a low conductivity member on the back of a nickel thin plate body (thickness 0.3 mm). Warping could actually be observed from an experiment in which a thin plate (thickness 0.3 mm) of SUS304 at 2 × 10 ⁻⁶ / ° C. was used as a reinforcing material. Here, the crosslinking reaction of the thermally active film starts from around 106 ° C., but when terminated at a high temperature around 150 ° C., the linear expansion coefficient between nickel and stainless steel is allowed to cool after leaving the crosslinking reaction. Due to the difference, the convex warpage of the mold surface 20a could be confirmed.

That is, the warpage when a die member is manufactured with a material having a different linear expansion coefficient using nickel as a thin plate material is as shown in Table 1 even when the thin plate body has a small material of about 280 mm × 200 mm.

Here, it is preferable that such warping does not occur. For example, as demonstrated by the examples described later, if the thickness of the reinforcing material is sufficiently thin, warping is performed under the pressure holding condition in the present invention. Is within this range, it is possible to produce a molded product that fully meets the specifications.

The thickness of such a reinforcing material is not particularly limited, but normally, the reinforcing effect is exhibited at 0.5 mm or more. For example, 2.5 mm SUS stainless steel is selected and demonstrated in the examples described later. Therefore, it is considered to be up to about 3 mm. That is, since the back surface is lined (supported) by the back plate, a small warp of the mold member 10 is substantially reduced by holding pressure in the molding cycle, and a molded product having a good appearance can be formed.

As a desirable reinforcing material, the difference in linear expansion coefficient from the material of the thin plate body is within a range of ± 6 (× 10 ⁻⁶ / ° C.), more preferably ± 3 (× 10 ⁻⁶ / ° C.). Within range. Examples of such a material having a small difference in linear expansion coefficient from nickel include NSSC stainless steel (particularly ferrite), but are not limited thereto.

Since the joining method and joining conditions of the thin plate body and the low thermal conductivity member or the joining method and joining conditions of the low thermal conductivity member and the reinforcing material are equal to or the same as the manufacturing conditions of the mold member shown in FIG. Detailed description is omitted.

Next, the mold 100 described above is used by being attached to an injection molding machine. A light control member molded into a thin plate shape can be manufactured by this injection molding method.

Such a light control member is a thin plate-like resin molded product including a sheet-like form, a film-like form, etc., and has two large opposing surfaces constituting the thin plate-like resin molded product (hereinafter, this surface is the main surface). At least one surface is used as an exit surface for emitting light.

In such a light control member, incident light is incident from at least one surface such as a main surface or a side surface of the control member. The incident light is propagated through the inside of the light control member with refraction or reflection in a plane direction and / or a direction (including a vertical direction) intersecting the plane. In this refraction or reflection process, the traveling direction of the incident light is controlled and emitted from at least one main surface. In such a light control member, at least one of the two main surfaces is provided with a fine uneven surface for controlling the direction of the emitted light. The other main surface may be an uneven surface having the same or different form, or may be a smooth surface. Accordingly, the mold surface 20a of the mold member according to the embodiment of the present invention is provided with an uneven surface or a mirror surface corresponding to the fine uneven surface of the light control member.

An example of the light control member whose incident surface is a side surface is a light guide plate, and this light guide plate is a component of a side edge type backlight used in a display device such as a liquid crystal. In the side-edge type backlight, light is incident with one end face (one side face) having a small thickness of the light guide plate as an incident end face. The light incident on the light guide plate travels while being reflected and / or refracted between the two main surfaces toward the side surface (the other end surface) facing the incident end surface. Light incident in this propagation process is emitted with one main surface as an emission surface, and is used as a backlight of a liquid crystal display device.

An example of the light control member whose incident surface is the main surface is a diffusion plate as a component of a liquid crystal display device. In this diffusing plate, light enters from one main surface which is a large opposing surface of a thin plate shape. The incident light travels toward the main surface (the other main surface) opposite to the incident surface (the one main surface), and is emitted from the other main surface. In this incident and exit process, incident light is diffused by the effect of the diffusion plate. That is, in the diffusion plate, the direction of light is diffused in the process of light passing through the diffusion plate.

Specific examples of such a light control member are not limited to the light guide plate and the diffusion plate used for other purposes in addition to the light guide plate and the diffusion plate used in the above-described liquid crystal display device, and light is transmitted in a specific direction. It may be a lens sheet such as a prism sheet, a Fresnel lens, or a lenticular lens. In any case, the emission surface from which light is emitted is the main surface, and in the light control member (injection molded product) according to one embodiment of the present invention, at least one main surface is provided with fine irregularities.

In recent years, in response to the increase in size of liquid crystal display devices, plasma televisions, and the like, various light control members such as light guide plates, diffusion plates, and prism sheets that are used there have been demanded seamless large-sized integrally molded products. Such a large integrally molded product is much larger than the diameter of an optical disk or the like, for example, a large molded product corresponding to a display screen having a side length of more than 50 cm, particularly a long side exceeding 80 cm. It is rare. Such a light control member has a feature that the production amount per brand is smaller than that of an optical disk or the like. Therefore, it is necessary to exchange the mold in a complicated manner.

Here, the mold member according to an embodiment of the present invention has a feature that it can be applied to a large-sized molded product that can cope with such a complicated brand exchange because the handleability is extremely good. . However, it goes without saying that the mold member according to the present invention may be used when manufacturing a small molded article.

By using such a mold, the light control member can be molded by the injection molding method described in Patent Document 1.

That is, in such a mold, a thermoplastic resin having a temperature equal to or higher than the transfer start temperature is introduced into a cavity portion constituted by a mold held at a temperature equal to or lower than the transfer start temperature, and is cooled by the mold. Cavity side of the mold so that the thermoplastic resin near the mold surface that has fallen below the transfer start temperature rises again to a temperature exceeding the transfer start temperature after the cavity is filled with the thermoplastic resin. Thus, the heat capacity of the surface portion is set.

Thus, by preparing a large number of mold members 10 having different concavo-convex patterns on the mold surface 20a, it is possible to quickly and appropriately cope with complicated brand changes.

That is, when forming the light guide plate, if the light guide plate has an uneven pattern on the surface, it should be formed on the surface of the light guide plate on the mold surface 20a constituting the cavity portion of the thin plate member. Concavities and convexities opposite to the concavity and convexity pattern are provided. Further, if the light guide plate to be molded has a texture on the surface, the mold surface 20a constituting the cavity portion of the thin plate member is textured. Further, if the light guide plate to be molded is printed with a dot-like pattern, the mold surface 20a of the thin plate member remains a mirror surface (plane).

If the light guide plate to be molded has a concavo-convex pattern or texture on both the front and back sides, a thin plate member may be provided on both sides of the mold cavity. If the concavo-convex pattern or texture is only on one side of the light guide plate, a thin plate member may be provided on one side of the cavity (surface with the concavo-convex pattern or texture), and the other surface may remain a mirror surface. You may provide (in this case, the surface of one thin-plate member is a mirror surface).

Further, according to an embodiment of the present invention, when a lens sheet is molded, a mold member having a mold surface 20a suitable for the lens sheet may be attached.

In either case, transferability is improved and the occurrence of weld marks, cold resin marks, flow marks, etc. is reduced.

The thermoplastic resin used in the method of the present invention is not particularly limited, and examples thereof include polymethyl methacrylate, polycarbonate, polystyrene, polypropylene, polyethylene terephthalate, polyvinyl chloride, thermoplastic elastomer, and copolymers thereof. .

Next, the reason why the transferability is improved and the occurrence of weld marks, cold resin marks, flow marks and the like is reduced by the molding method of the resin molded product of the present invention will be described in a part of Patent Document 1. However, refer to Patent Document 1 for details. Here, as an example, simulation results by unsteady heat conduction analysis using MARC (made by MARC) when polymethyl methacrylate resin (made by Kuraray Co., Ltd., trade name: Parapet HR-1000LC) is used as the resin are described. ing.

The temperature dependence of the storage modulus is obtained from the measurement result (FIG. 4) of the relationship (bending mode) between the temperature and the longitudinal elastic modulus of the polymethyl methacrylate resin used. The temperature at which the slope of the graph changes greatly is the transfer start temperature in this specification. This transfer start temperature is determined by the intersection of the tangent line of the graph of the phase transition region and the tangent line of the graph of the rubber-like flat region, and the transfer start temperature determined by this FIG.

Next, main specifications of the injection molding apparatus (mold 100) employed in the simulation, the molded product 60 that is a light control member, and molding conditions are as follows (see FIG. 5).

Thickness of molded product 60: 3 mm
Mold 100 (carbon steel) thickness: 25mm
Thin plate body 20 (nickel) thickness: 0.3 mm
Filling time: 1.4 seconds Molding cycle: 60 seconds Temperature of mold 100: 85 ° C
Heat transfer coefficient on the cooling water side: 1.0 × 10 ⁻³ cal / mm ² · sec · ° C.
Temperature of polymethyl methacrylate resin injected and filled into the cavity: 280 ° C
In this simulation, as shown in FIG. 5, a mold 100 provided with a cooling facility 70 for passing cooling water through a surface (back surface) 100b facing the cavity is used. A thin plate member 10 is mounted on one surface of the mold 100 on the cavity side. The thin plate member 10 includes a thin plate main body 20 disposed on the cavity surface (mold surface) 20a and a low thermal conductivity member 30 disposed on the back surface 20b. The uneven structure formed on the mold surface 20a of the thin plate main body 20 has a height h of 13 μm and a pitch p of 30 μm. This concavo-convex structure is a pattern of the exit surface of the light guide plate used for the side edge type backlight of the liquid crystal display device.

The results of the simulation are shown in FIGS. 6 and 7. In FIG. 7, the time axis of FIG. 6 is extended. 6 and 7, reference numerals (a), (b), and (c) indicate simulation results of the time (seconds) after injection and the temperature of the surface in contact with the mold of the polymethyl methacrylate resin. (D) shows the simulation result of the relationship between the time (second) after injection and the temperature of the central part of the resin in the cavity of the polymethylmethacrylate resin.

Here, the code | symbol (a) is a simulation result which concerns on a control example, and in this control example, the same metal mold | die (product made from carbon steel) is shown in FIG. 2, except the low heat conductivity member 30 is not mounted | worn. It is used.

The symbol (b) is an example in which a film made of polyethylene terephthalate having a thickness of 0.1 mm is used as the low thermal conductivity member 30, and the symbol (c) is a thickness as the low thermal conductivity member 30. This is an example in which a film made of polyethylene terephthalate having a thickness of 0.15 mm was used. Here, the thermal conductivity of the polyethylene terephthalate film is 0.126 kcal / m · hr · ° C., and the thermal conductivity of the thin plate body 20 is 79.2 kcal / m · hr · ° C.

As shown by the curves (b) and (c) in FIG. 6, when using the mold 100 in which the low thermal conductivity member is attached to the back surface of the thin plate main body 20, polymethyl methacrylate set at 280 ° C. When the resin is introduced into the cavity portion, the polymethylmethacrylate resin in contact with the cavity surface 20a of the mold 100 is the mold surface (cavity surface) 20a of the thin plate body 20 that is set to substantially the same temperature as the mold 100. It cools quickly and falls once below the transfer start temperature. However, as indicated by reference numeral (d) in FIG. 7, the temperature of the center portion of the filled resin is sufficiently high, the heat capacity of the thin plate body 20 is appropriately set, and low heat is applied to the back surface of the thin plate body 20. By disposing the conductivity member 30, the transfer start temperature (128 ° C.) is exceeded instantaneously (within 1 second in these examples). As a result, the resin filled in the cavity forms a cooling solidified layer instantaneously in the vicinity of the mold surface (mold surface 20a), but this cooling is caused by the resin temperature again exceeding the transfer start temperature. The solidified layer disappears. In this state, pressure is applied to the resin in the cavity in the pressure holding process, and the resin having a temperature equal to or higher than the transfer start temperature is pushed into the concavo-convex pattern. As shown in FIG. 7, the molding cycle of 60 seconds is a time sufficient for the temperature of the center of the resin filled in the cavity to be sufficiently lower than the transfer start temperature. The uneven pattern is transferred to obtain a molded product (light guide plate). Further, in such a molded article, since the cooling solidified layer that causes orientation strain, cooling strain, and the like disappears instantaneously, generation of weld marks, cold resin marks, flow marks, and the like can be suppressed.

On the other hand, as shown by the curve (a) in FIG. 6, in the control example in which the low thermal conductivity member 30 is not disposed on the back surface of the thin plate main body 20, polymethyl methacrylate in the vicinity of the surface of the mold 100. The resin becomes equal to or lower than the transfer start temperature immediately after filling with the resin, and does not exceed the transfer start temperature thereafter. Thereby, since the cooling solidified layer formed in the polymethyl methacrylate resin in the vicinity of the mold surface 20a is pushed into the concavo-convex pattern with pressure (holding pressure) from the inside, orientation distortion, cooling distortion, etc. occur, and the weld mark, Cold resin marks, flow marks, etc. are generated.

In the mold 100 described above, the low thermal conductivity member 30 is disposed on the back surface 20b of the thin plate body 20, and the low thermal conductivity member 30 is a film. Here, in this simulation, a polyethylene terephthalate film is used as the low thermal conductivity member 30, but when the resin temperature to be filled is as high as 280 ° C., the polyimide film is industrially considered in consideration of heat resistance. It is practical. Patent Document 1 describes a specific experimental example in which a polyimide film is bonded to the back surface of the thin plate body 20 as a heat resistant member 30.

Hereinafter, the present invention will be described in detail by way of examples.
Example 1
As the thin plate main body, a nickel thin plate having a thermal conductivity of 79.2 kcal / m · hr · ° C., a thickness of 0.3 mm, and a size of 250 mm × 220 mm was used. On the cavity side surface of the thin plate main body, an isosceles prism-shaped uneven pattern having a pitch p of 50 μm and a height h of 25 μm is arranged.

On the back surface (the surface opposite to the cavity) of the thin plate main body, a thermal activation film (trade name) manufactured by Tesa with a thermal conductivity of 0.3 kcal / m · hr · ° C. and a thickness of 0.125 mm A polyimide film (low thermal conductivity member) having a thermal conductivity of 0.3 kcal / m · hr · ° C. and a thickness of 0.125 mm was integrated by adhesion via tesaHAF8402).

Bonding integration was performed in two stages, a first process (laminating process) and a second process (curing process). The laminating process was carried out using a laminating roll, heated to 110 ° C., at a pressure of 0.5 MPa, and a feed rate of 0.4 m / min. Under these conditions, the thermally active film is in a molten state and can sufficiently penetrate into the irregularities on the surface of the adherend.

Next, the curing step is to maintain the heat-active film at 130 ° C. for 3 hours under a pressure of 0.2 MPa to form an adhesive layer that integrates the polyimide film and the thin plate main body with sufficient durability. did it.

On the other hand, engraving from the parting surface of the mold at a depth corresponding to the thickness of the thin plate member, mounting the thin plate member obtained in this recess, and using polymethylmethacrylate resin to guide by the injection molding method. A light plate was molded.

The cylinder temperature at this time was 270 ° C., and the molding cycle was 70 seconds. The internal pressure (holding pressure) at which the prism shape is transferred is around 38 MPa, and the height of the obtained prism is 25 μm, which is the same as the depth of the engraved irregularities, and each has a good irregular pattern. It was confirmed that

Even in repeated injection molding, there was no separation of the stamper due to thermal deterioration at the injection site where much heat was received from the resin, or no stamper displacement or thickness change due to insufficient hardness. Thereby, it was possible to repeatedly use 5000 to 20000 shots.
(Example 2)
A nested mold was used in which the back surface penetrated to the back plate of the mold. A recess was formed in the cavity surface of the insert mold, and the thermally active film obtained in Example 1 was disposed in the recess.

Next, the back surface of the thin plate member obtained in Example 1 was thermocompression bonded to the surface of this thermally activated film under the same conditions as in Example 1. As a result, the thin plate member was embedded in the cavity surface of the nest so that the parting surface was flush with the mold surface 20a.

When injection molding was performed under the same conditions as in Example 1, a good injection molded product could be obtained as in Example 1.

Thereby, it was confirmed that the same favorable molded article can be obtained by making the cavity surface of a nested mold into the mold member which concerns on one Example of this invention.
(Example 3)
A stainless steel material (SUS304) having a thickness of 2.0 mm as a reinforcing material was adhered to the back surface of the thin plate member obtained in Example 1 through the same thermally active film as used in Example 1. The bonding conditions are the same as in Example 1.

Since such a thin plate member has a reinforcing material on the back surface and is thin, even when the thin plate member itself becomes large, it can be mounted on a mold and has good operability. there were.

When injection molding was performed under the same conditions as in Example 1, a good injection molded product could be obtained as in Example 1.
Example 4
As the thin plate main body, a nickel thin plate having a thermal conductivity of 79.2 kcal / m · hr · ° C., a thickness of 0.3 mm, and a size of 335 mm × 230 mm was used. On the cavity side surface of the thin plate main body, an isosceles prism-shaped uneven pattern having a pitch p of 24 μm and a height h of 8.5 μm is arranged.

On the back surface (the surface opposite to the cavity) of the thin plate main body is a thermally active film (manufactured by Yodogawa Paper Mill Co., Ltd.) having a thermal conductivity of 0.3 kcal / m · hr · ° C. and a thickness of 0.015 mm. A polyimide film (low thermal conductivity member) having a thermal conductivity of 0.3 kcal / m · hr · ° C. and a thickness of 0.125 mm was integrated by bonding via a trade name SJ41).

Next, in the curing step, the heat-activated film was maintained at 150 ° C. for 3 hours, whereby the thermoactive film could be made into an adhesive layer that integrated the polyimide film and the thin plate main body with sufficient durability.

The cylinder temperature at this time was 295 ° C., and the molding cycle was 40 seconds. The internal pressure (holding pressure) at which the prism shape is transferred is around 200 MPa, and the height of the obtained prism is 8.5 μm, which is the same as the depth of the engraved irregularities. It has been confirmed that.

Even in repeated injection molding, there was no separation of the stamper due to thermal deterioration at the injection site where much heat was received from the resin, or no stamper displacement or thickness change due to insufficient hardness. As a result, repeated use of 10,000 to 50,000 shots was possible.
(Example 5)
A nested mold was used in which the back surface penetrated to the back plate of the mold. A recess was formed in the cavity surface of the insert mold, and the thermally active film obtained in Example 4 was disposed in the recess.

Next, the back surface of the thin plate member obtained in Example 4 was thermocompression bonded to the surface of this thermally activated film under the same conditions as in Example 4. As a result, the thin plate member was embedded in the cavity surface of the nest so that the parting surface was flush with the mold surface 20a.

When injection molding was performed under the same conditions as in Example 4, a good injection molded product could be obtained as in Example 4.

Thereby, it was confirmed that the same favorable molded article can be obtained by making the cavity surface of a nested mold into the mold member which concerns on one Example of this invention.
(Example 6)
A stainless steel material (SUS304) having a thickness of 0.8 mm as a reinforcing material was adhered to the back surface of the thin plate member obtained in Example 4 through the same thermally active film as used in Example 4. The bonding conditions are the same as those in Example 4.

When injection molding was performed under the same conditions as in Example 4, a good injection molded product could be obtained as in Example 4.
(Example 7)
After bonding a 0.8 mm thick stainless steel material (SUS304) as a reinforcing material to the back surface of the thin plate member obtained in Example 4 through the same thermally active film as used in Example 4, A mirror-like nickel thin plate having the same thickness and size as those used in Example 4 was bonded via the same thermally active film as used in Example 4. The bonding conditions are the same as those in Example 4.

Such a thin plate member has the same nickel plate as the front and back thin plates, so that the warpage of the plate after bonding is reduced and the mounting property to the mold is good.

When injection molding was performed under the same conditions as in Example 4, a good injection molded product could be obtained as in Example 4.
(Example 8)
Adhering the same low thermal conductivity member as used in Example 4 to the same nickel thin plate as used in Example 4 via the same thermally active film as used in Example 4, and then The nickel thin plate was integrated by electroforming the back surface.
Such a manufacturing method is known, for example, from Japanese Patent Laid-Open No. 2001-071354. However, in the method of directly plating nickel on the back surface of the low thermal conductivity member by the manufacturing method of Japanese Patent Laid-Open No. 2001-071354, nickel and low thermal conductivity are used. It was found that the adhesion with the rate member was poor and the nickel layer could not be formed. In Example 9, the adhesiveness is improved by using the same thermally active film as used in Example 4 between the low thermal conductivity layer and the nickel layer formed by plating. Different from 2001-071354.

Since such a thin plate member has the same front and back configurations with a low thermal conductivity member as the center, it is possible to reduce the warpage of the plate caused by the difference in thermal expansion coefficient, and the mounting property to the mold is good. It was.

The heat activated film (trade name SJ41) manufactured by Yodogawa Mill used in Examples 4 to 6 generates less gas at high temperatures, and is compared with, for example, TESA (tesa HAF8402) which is a similar heat active film. Furthermore, there was little deterioration during repeated use during injection molding, and good results were obtained.
(Control 1)
Instead of the thermally active film made by Tessa used in Example 1, Nitto Denko's adhesive film (trade name: MC2030) and (trade name: 5919P) were used to bond the nickel thin plate and the polyimide film.

When molding was performed under the same conditions as in Example 1, peeling of the pressure-sensitive adhesive film due to thermal deterioration occurred at the site subjected to high-temperature injection molding. Further, in the molding process, it was confirmed that the stamper was misaligned or soiled. Moreover, the variation in the thickness direction of the obtained molded product was large.

These causes are presumed that the pressure-sensitive adhesive film is insufficient in hardness and shear force, so that it is inappropriate to continue continuous molding even if the thin plate body and the heat insulating film are bonded with the adhesive film. It seemed to be.
(Control 2)
Although an example in which the polyamic acid solution is spin-coated on the back surface of the thin plate main body was tried, according to this method, it was difficult to secure a necessary thickness as a low thermal conductivity member necessary for the present invention.

Industrial application fields

According to the present invention, a lens sheet such as a light guide plate, a diffusion plate, a Fresnel lens sheet, and a lenticular lens sheet having a large area can be manufactured. That is, conventionally, a large lens sheet such as a Fresnel lens sheet or a lenticular sheet contacts a heated plate lens mold with a resin plate and pressurizes it to transfer the uneven lens surface of the lens mold surface to the resin mold. And a technique of applying a UV curable resin to a lens mold, placing a resin plate on the lens mold and irradiating with UV light, and forming a lens with the UV curable resin.

However, the transfer method has a problem that the molding cycle is long and the productivity is not high.

According to the present invention, it is assumed that even optical control parts having a relatively large size can be formed by injection molding, so that productivity can be dramatically improved.

According to the present invention, it is possible to provide a mold member that can be exchanged and can be stably produced even when used for a long time.

Further, according to the present invention, a resin molded product capable of controlling light in a size larger than that of the optical disk substrate can be manufactured with high productivity.

(Claiming priority)
This application claims priority based on Japanese Patent Application No. 2007-336514 filed with the Japan Patent Office on December 27, 2007, the contents of which are incorporated herein by reference.

Claims

A mold member that is used in the manufacture of a light control member by an injection molding method using a mold, and can be attached to and detached from the mold,
A metal thin plate body having a mold surface and having a thickness of 0.2 mm or more and 0.6 mm or less;
A low thermal conductivity member having a thickness of 0.1 mm or more and 0.5 mm or less, which is disposed integrally with the thin plate body on a surface facing the mold surface;
A reinforcing agent provided integrally on the back surface of the low thermal conductivity member;
A mold member comprising:
The light control member injects the heat-fluidized resin material into a cavity in the mold, and solidifies by cooling or hardening while maintaining a high pressure in the mold, and then opens the mold to form a thin plate. Manufactured by the injection molding method to take out the resin molded product,
The light control member is used as an emission surface on which at least one of two opposing large plate-like surfaces emits light, and
The mold member according to claim 1, wherein the mold surface of the mold member forms one surface of a cavity.
2. The mold member according to claim 1, wherein the thin plate main body and the low thermal conductivity member are integrated by a thermosetting heat-resistant adhesive.
3. The mold member according to claim 2, wherein the thermosetting heat-resistant adhesive does not generate a curing by-product.
The low thermal conductivity member includes a first heat-resistant adhesive layer having a low thermal conductivity within a range of 10 μm or more and 200 μm or less, a low thermal conductive layer within a range of 10 μm or more and 200 μm or less, and a thickness of 10 μm or more. The mold member according to claim 1, further comprising a second heat-resistant adhesive layer having a low thermal conductivity within a range of 200 µm or less.
The mold member according to claim 5, wherein the first and / or second heat-resistant adhesive does not generate a cured by-product.
2. The mold according to claim 1, wherein the thin plate main body and the reinforcing material are made of different materials having a difference in linear expansion coefficient of ± 6 (× 10 −6 / ° C.) or less. Element.
2. The mold member according to claim 1, wherein the material forming the thin plate main body is mainly nickel or chromium, and the material forming the reinforcing material is stainless steel.
6. The material for forming the thin plate main body is mainly nickel or chromium, and the material for forming the reinforcing material is a laminate of stainless steel and a material for forming the thin plate main body. The mold member as described.
6. The mold member according to claim 5, wherein the material forming the thin plate main body is mainly nickel, and the material forming the reinforcing material is nickel made by electroforming.
6. The mold according to claim 5, wherein each of the first heat-resistant adhesive layer, the low thermal conductive layer, and the second heat-resistant adhesive layer is a film-shaped layer. Element.
The mold member according to claim 1, wherein the thickness of the reinforcing material is 0.5 mm or more.
The mold member according to claim 1, wherein the thickness of the reinforcing material is in a range of 0.5 mm or more and 5 mm or less.
A method of manufacturing a mold member that is used for manufacturing a light control member by an injection molding method and that can be attached and detached as a cavity surface of a mold,
Prepare a sheet metal body with a thickness of 0.2 mm or more and 0.6 mm or less with a mold surface,
A low thermal conductivity member having a thickness in the range of 0.1 mm or more and 0.5 mm or less is disposed on the back surface of the thin plate main body, which is a surface facing the mold surface,
The interface between the thin plate main body and the low thermal conductivity member is integrated using a film-like adhesive as a thermosetting heat-resistant adhesive,
Reinforcing material is disposed on the back surface of the low thermal conductivity member, integrated with the low thermal conductivity member,
The low thermal conductivity member includes a first heat-resistant adhesive layer having a low thermal conductivity within a range of 10 μm or more and 200 μm or less, a low thermal conductive layer within a range of 10 μm or more and 200 μm or less, and a thickness of 10 μm or more. A second heat-resistant adhesive layer having a low thermal conductivity within a range of 200 μm or less,
The material for forming the thin plate main body is mainly made of nickel, and the material for forming the reinforcing material is nickel produced by electroforming.
A method of manufacturing a mold member that is used for manufacturing a light control member by an injection molding method and that can be attached and detached as a cavity surface of a mold,
Prepare a sheet metal body with a thickness of 0.3 mm or more and 0.6 mm or less with a mold surface,
A low thermal conductivity member having a thickness in the range of 0.1 mm or more and 0.3 mm or less is disposed on the back surface of the thin plate main body, which is a surface facing the mold surface,
The interface between the thin plate main body and the low thermal conductivity member is integrated using a film-like adhesive as a thermosetting heat-resistant adhesive,
The integration process includes at least two steps of laminating the thin plate body, a first step of laminating the heat-resistant film as the low thermal conductive layer, and a second step of thermosetting at a temperature higher than the first step. The manufacturing method of the metal mold | die member characterized by including the process of integrating a main body and a low heat conductive film.
The mold member injects the heat-fluidized resin material into a cavity in the mold, and solidifies by cooling or hardening while maintaining the high pressure in the mold, and then opens the mold and forms into a thin plate shape. Used for the production of light control members by injection molding method to take out the resin molded product, can be attached and detached as the cavity surface of the mold,
16. The mold member manufacturing method according to claim 15, wherein the light control member is used as an emission surface from which at least one of two opposing large plate-like surfaces emits light. Method.
A thermoplastic resin having a temperature equal to or higher than the transfer start temperature is introduced into a cavity formed of a mold held at a temperature equal to or lower than the transfer start temperature.
The thermoplastic resin in the vicinity of the mold surface that has been cooled by the mold and lowered to a temperature lower than the transfer start temperature rises again to a temperature that exceeds the transfer start temperature after the cavity portion is filled with the thermoplastic resin. As described above, a method of molding the light control member by setting the heat capacity of the surface portion on the cavity side,
The light control member is used as an emission surface on which at least one of two opposing large plate-like surfaces emits light, and
A metal thin plate body having a mold surface forming one surface of the cavity and having a thickness of 0.3 mm or more and 0.6 mm or less, and a back surface of the thin plate body that is a surface facing the mold surface The injection molding is performed while the plurality of mold members integrated with the low thermal conductivity member within the range of 0.1 mm or more and 0.3 mm or less are mounted and replaced by desorption. A method for forming a light control member.
The method for forming a light control member according to claim 17, wherein the light control member is a light guide plate.
The method for molding a light control member according to claim 17, wherein the light control member is a lens sheet.
The method for forming a light control member according to claim 17, wherein the light control member is a light diffusion plate.
18. The light according to claim 17, wherein the light control member has a concavo-convex pattern formed on an emission surface, and a concavo-convex pattern opposite to the emission surface of the light control member is formed on the mold surface. A method for forming the control member.
A mold member that is used in the manufacture of a light control member by an injection molding method using a mold and is detachable from the mold,
A metal thin plate body having a mold surface and having a thickness in the range of 0.3 mm or more and 0.6 mm or less;
A mold member comprising: a low thermal conductivity member having a thickness within a range of 0.1 mm or more and 0.3 mm or less and disposed integrally with the thin plate main body on a surface facing the mold surface.