JP5270389B2 - Method for producing cured resin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for forming a cured resin film capable of efficiently forming the resin film having a sufficiently low degree of brightness in order to be used as an optical member or the like, a light-scattering film, a light-shielding film, and a lens unit having the light-shielding film. <P>SOLUTION: In the method for forming the cured resin film, a surface irregular shape is formed by transfer on at least one surface of the cured resin film 3 formed of a cured resin composition and the cured resin film 3 is cured. The forming method forms the cured resin film having a step of applying pressure and heat in a state that the cured resin film 3 and a cast film 4 are laminated by using the cast film 4 for forming the surface irregular shape. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to a method for producing a cured resin film, a cured resin film produced by the production method, and an application thereof. More specifically, it is particularly suitable for optical applications, optical device applications, display device applications, etc., and can also be used as mechanical parts, electrical / electronic parts, etc. The present invention relates to a method for producing a cured resin film useful as a light-shielding film further imparted with light-shielding properties, a cured resin film produced by the production method, and a light-scattering film, a light-shielding film, and a lens unit as its use.

A resin film having a plurality of minute surface irregularities has a light scattering property due to the irregular shape and can reduce glossiness, and it is considered to be used in various optical members using such characteristics. ing. For example, since the light-shielding property of the light-shielding film can be enhanced by light scattering, in recent years, new uses such as a light-shielding film attached to a lens unit as an optical member are expected. The light-shielding film is used to suppress the generation and expansion of optical noise inside the lens unit in a camera module of a digital camera or a mobile phone camera.
By the way, in the optical member, the digital camera module is mounted on the mobile phone, and the miniaturization has been rapidly progressing in recent years, and the optical member has been required to be further reduced in size, thickness, and weight. Value is being promoted rapidly. Along with this, the light-shielding film used in digital camera modules, etc., and lens units with lenses, etc. are similarly required to be smaller, thinner and lighter, and not only that, but also cost reduction is required. Yes.

In such high functionality and high added value, in order to further reduce the cost in the manufacturing process, it is considered to assemble optical / electronic members such as digital camera modules and lens units by the reflow process. Yes. The reflow process (also called the solder reflow process) is not a conventional soldering process, but is a process in which soldering is performed by applying heat to the entire member after assembling the member. Thus, the manufacturing cost can be further reduced. In this case, an optical member such as a light-shielding film having a plurality of minute surface irregularities having excellent heat resistance and reflow resistance (withstanding reflowable specifications) is required.

As a method for producing such a resin film having surface irregularities, it has been studied to treat the resin film surface in the production process, or to use a material that exhibits surface irregularities as a raw material for forming the resin film. ing. For example, a method of sandblasting a polyester film mixed with carbon black (see, for example, Patent Document 1), an organic filler (mat agent) is bound to the surface of a base black film with a binder resin, and irregularities based on fine particles are formed. Method of forming (for example, refer to Patent Document 2), organic filler, black fine particles are bound to the surface of the transparent substrate film with a binder resin to form irregularities based on the fine particles and blackening the manufacturing method (for example, Patent Document) 3) is disclosed. In addition, for the purpose of producing an optical information recording medium having an uneven surface shape, a photocurable transfer sheet and a nickel plate having an uneven shape are laminated, and a load is applied to the photocurable transfer sheet using a roller. The manufacturing method (for example, refer patent document 4) which presses and forms uneven | corrugated shape is disclosed.

JP-A-1-120503 JP 2003-147275 A JP 2003-266580 A JP 2003-272228 A

When the resin film surface is sandblasted as in the manufacturing process in the prior art, the process is complicated and stable quality cannot be obtained. Further, when forming surface irregularities using fine particles as a raw material for forming a resin film, the fine particles affect the performance of the resin film, and for example, it is considered that the performance such as heat resistance is lowered.
Furthermore, even in the technology using a photocurable transfer sheet for forming a surface uneven shape, it is limited to the photocurable one, and thus it is suitably applied to various applications requiring performance such as heat resistance. There was room for ingenuity to make it possible. Further, in this technique, a metal stamper having irregularities is used to form surface irregularities. However, it is economical to form minute irregularities and uniformly controlled surface irregularities. It is difficult to do in the industrial production process. Light scattering performance against visible light (transparent or light-shielding body) in (semi) transparent light-scattering films and light-shielding films such as light diffusion films, especially those used for optical elements such as imaging lens units However, it can be said that a film for such a use cannot be produced unless surface irregularities that are fine and whose size is uniformly controlled cannot be formed. In addition, forming the surface irregularities using such a stamper can be performed only in so-called batch production, and cannot be produced continuously and efficiently. Furthermore, the stamper itself is expensive and cannot be said to be an industrially advantageous method.
For these reasons, it has been required to manufacture a high-quality resin film economically and inexpensively in applications such as optical members in the technology using a mold film. That is, when a mold film is used, it is possible to continuously form uneven shapes of various aspects on the surface of the cured resin film, and this point is useful in an industrial production process. There was room for ingenuity to suppress problems when using. Furthermore, a technique capable of providing a film having high gloss-reducing performance by imparting a concavo-convex shape with high quality by sufficiently transferring the surface concavo-convex from the mold film has been expected.

First, as a method for producing a resin film having a stable quality, the present inventors have developed a method for producing a resin film by forming a surface irregularity shape by transfer on the surface of a resin film formed from a resin composition. Pay attention. In addition, among the resin films produced in this way, it is effective to use a cured resin film formed from a curable resin composition as one that has basic performance such as heat resistance and can withstand reflowable specifications. I focused on that.

By the way, as a manufacturing method for manufacturing a resin film having a surface uneven shape formed from a curable resin composition, a mold film for forming a surface uneven shape is used, and the curable resin composition is applied to the mold film. (Solvent casting method) It is conceivable to cure after the transfer treatment. If a mold film is used, the uneven shape of various aspects can be imparted to the film surface, which is useful in industrial production processes. In the case of producing a cured resin film in this way, if the film is not cured after the transfer process, that is, if the transfer process is not performed before the curable resin composition is substantially completely cured, sufficient transfer can be performed. Can not.
However, such a manufacturing method causes problems such as warping (curling) of the manufactured resin film. If the resin film is curled, it cannot be suitably applied to an optical member or the like that requires high optical performance. For example, curling occurs when a resin film obtained by curing after transfer treatment is peeled off from a mold film. Therefore, it has been difficult to obtain a stable and high-quality resin film that can be suitably applied to various uses while maintaining the gloss reduction effect due to the uneven surface shape.
For example, according to the following method, a curled resin film is obtained.
That is, a method of applying a curable resin composition to a matte film, drying it to form a film, and curing the curable resin film having the peeled surface irregularities formed by heating, and applying the curable resin composition to a base film Coating, drying, forming a film, mat roll treatment, removing the curable resin film with surface irregularities, and curing by heating, applying the curable resin composition to the substrate film, and drying Depending on the method of curing the curable resin film with the surface irregularities formed by peeling and forming a mat roll treatment by heating, it is possible to produce a resin film with sufficiently suppressed curling could not.

The present invention has been made in view of the above situation, has a basic performance such as heat resistance, can withstand reflowable specifications, and has a surface uneven shape useful for various uses such as optical members. When producing a resin film, a method for producing a resin film that can be produced efficiently at a low cost by suppressing curling (suppressing the occurrence of problems such as curling) and producing by such a manufacturing method A resin film suitable for optical members such as a light diffusing film, a light shielding film, etc., which has no curls, has excellent flatness, has a fine concavo-convex shape, and has excellent heat resistance and high performance and quality. An object of the present invention is to provide a light-scattering film, a light-shielding film, and a lens unit as its application.

The inventors of the present invention manufactured a cured resin film having a concavo-convex shape using a mold film from a curable resin composition, and variously studied production methods in which the occurrence of curling was suppressed. After forming a surface irregularity shape by applying pressure and heat treatment in a state in which a curable resin film and a mold film formed by laminating are laminated, it is cured (hardened and then peeled or peeled and then cured) Thus, it has been found that a cured resin film in which curling, which is a defect associated with curing, does not occur or curling is suppressed can be obtained. As a curable resin film, it is difficult to transfer the concavo-convex shape if it is completely cured before forming the concavo-convex shape by the mold film. A simple film (film) will be used. The curling is considered to be due to the curing shrinkage of the curable resin film. The cause of the occurrence of curl is not clear, but may be due to the difference in the surface shape between the two surfaces of the curable resin film, the difference in curing shrinkage due to the difference in surface area, and the difference in stress relaxation. In addition, when the curable resin film contains a volatile component (solvent), the rate at which the solvent volatilizes on both surfaces of the curable resin film is different, resulting in a difference in shrinkage rate, which also acts synergistically. Conceivable. As a result, curling is considered to occur. In the present invention, it has been found that by applying pressure and heat treatment in the state of a laminated film, curling can be suppressed even when the curable resin is cured later.

In the conventional technology, it was not possible to sufficiently suppress the occurrence of curling in the resin film manufacturing process, but in addition to pressurizing the laminated film of the curable resin film and the mold film, in the state of the laminated film Heat treatment is preferably performed before the curing step of the curable resin film, so that the transferability is improved and the gloss reduction effect due to the provision of the surface irregularity shape is maintained, and the curl in the manufacturing process is maintained. The present inventors have found that an unexpected effect of sufficiently suppressing the occurrence of defects such as the above can be achieved, and the above-mentioned problems can be solved brilliantly, and the present invention has been conceived. As described above, in the production method of the present invention, by using the mold film, it is possible to continuously form the uneven shape of various aspects on the surface of the cured resin film, and to sufficiently transfer the uneven shape. It is possible to provide a resin film suitable for applications that require high quality such as optical members by improving the gloss reduction performance and suppressing the occurrence of curling.
Moreover, as a preferable form of the present invention, a form in which pressure and heating are performed in a state where the curable resin film has a volatile content, a heating medium having a specified surface temperature is used, and the temperature of the heating medium on the curable resin film side is A form in which the temperature is higher than the temperature of the heating medium on the mold film side, a form in which the roll is used as a pressurizing and heating medium, a roll having at least two rolls and a surface layer as an elastic body is essential, and the curable resin film side is It has also been found that the form in contact with the surface layer of the elastic roll, the form for specifying the linear pressure between the rolls, the form in which the resin composition contains a black material, and the like are suitable.

That is, the present invention is a method for producing a cured resin film by forming a surface irregular shape by transfer on the surface of a curable resin film formed from a curable resin composition, and curing the curable resin film, The production method is a production method of a cured resin film having a step of applying pressure and heating in a state where a curable resin film and a mold film are laminated using a mold film for forming a surface uneven shape.
This invention is also a cured resin film manufactured by the said manufacturing method, and is also a light-scattering film provided with the said cured resin film. Furthermore, it is a light-shielding film comprising the light-scattering film, and the light-shielding film is a light-shielding film having a transmittance of less than 1% for light having a wavelength of 550 nm.
The present invention is a lens unit including the light-shielding film and a lens, and the lens unit is also a lens unit that is a lens unit for an image sensor.
The present invention is described in detail below.

In the production method of the present invention, a mold film for forming a surface irregular shape is used, and pressure and heating are performed in a state where a curable resin film and a mold film are laminated.
In the pressurization and heating step, a preferred embodiment in which pressurization and / or heating is performed is a mode of heating by bringing a heating medium into contact with the curable resin film and the mold film. More preferably, by pressing and heating using a roll as a pressurizing and heating medium, more preferably by passing between at least two rolls in a state where a curable resin film and a mold film are laminated. It is the form which pressurizes and heats.
In the above process, the state in which the resin film and the mold film are laminated may be such a state until at least the transfer process is performed, that is, before the pressurization and heating are performed. For example, when the heating medium is brought into contact with the curable resin film and the mold film, it is only necessary to be in such a state when pressing and heating with a roll. In the form of transfer processing using at least two rolls, such a state may be used when passing between at least two rolls, for example, a film in which a curable resin film and a mold film are laminated in advance. May be supplied between the two rolls, and the curable resin film and the mold film may be separately supplied between the two rolls so that lamination and transfer occur simultaneously when passing between the rolls. Good. Usually, the mold film may be laminated on the surface of the curable resin film that gives the uneven shape, and when the uneven shape is given to one surface of the curable resin film, the curable resin that gives the uneven shape. When the mold film is laminated on one surface of the film and the concave and convex shapes are provided on both surfaces of the curable resin film, the same or different mold film is laminated on both surfaces of the curable resin film. It will be.

Next, preferable transfer conditions in the present invention, that is, the relationship between the laminated film and the pressure and / or heating medium, and the setting in the pressure and / or heating medium will be described.
As described above, the laminated film is formed by laminating a curable resin film (also referred to as curable resin film A) and a mold film (also referred to as surface uneven film B), and other films (others) May also be laminated. Here, as shown in FIG. 2, when the curable resin film A is on one side of the laminated film, that is, the curable resin film A is on one side of the laminated film, the “curable resin film A side” (FIG. 2). (A)) or when the other film C is on the curable resin film A (surface layer side of the laminated film), the other film C side on the curable resin film A (FIG. 2B) ) Is the “curable resin film A side”, and when the surface uneven film B is on one side of the laminated film, that is, the surface uneven film B is on one side of the laminated film, the “surface uneven film B side” (FIG. 2 (c) )), Or when the other film C is on the surface uneven film B (the surface layer side of the laminated film), the other film C side (FIG. 2 (d)) on the surface uneven film B "Uneven film B side".

It is preferable that the pressurization and the heat treatment are performed substantially simultaneously. As long as pressurization and heating are performed substantially simultaneously, the pressurization time may be longer than the heating time, or conversely, the heating time may be longer than the pressurization time. By this pressurization and heat treatment, the concavo-convex shape of the mold film is transferred to the curable resin film, but the curing reaction of the curable resin film to some extent may proceed due to the heating.
As the pressurization and heat treatment method, a pressurization and / or heating medium is used.
For example, a pressure and / or heating medium is brought into contact with one side or both sides of a laminated film including a laminated film of a curable resin film and a mold film or other films. Preferably, pressurization and heat treatment are performed so as to sandwich the pressurization and / or heating medium from both sides of the curable resin film A side and the surface uneven film B side.
Examples of the form of pressurization and / or heat treatment using a pressure medium and / or a heating medium from the one side include a form of fixing the laminated film and using a pressing device such as a roller from one side. As a form which pressurizes and heat-processes using a pressure and / or a heating medium, the form performed by passing between at least 2 rolls is mentioned.

In the said pressurization and heating process, it is preferable to pressurize and heat in the state in which curable resin film has a volatile matter. For example, when a curable resin film is prepared by applying a curable resin composition on a mold film by a solvent casting method as described later, it is preferable because it is simple and efficient as a resin film manufacturing process. Therefore, the curable resin composition contains a volatile component such as a solvent. In such a case, the curable resin film before being completely cured contains volatile components such as a solvent, and the solvent is volatilized when the curable resin film is cured. In addition, problems such as curling occur in combination with the effects of curing of the curable resin, but in the present invention this can be sufficiently suppressed. Therefore, in the said preferable form, the advantageous effect of this invention can be show | played corresponding to preparation of the curable resin film by application | coating.
The content of the volatile component is preferably 1 to 40% by mass when the curable resin film is 100% by mass. Preferably, the lower limit of the volatile content is 5% by mass or more, more preferably 10% by mass or more. Moreover, regarding an upper limit, it is 35 mass% or less, More preferably, it is 30 mass% or less. Thus, the present invention can be suitably applied also when preparing a curable resin film by coating. Moreover, when apply | coating and drying a curable resin composition and obtaining a curable resin film, it can be set as a moderate dry state.

In the production method of the present invention, it is preferable to use a pressurization and / or heating medium in order to pressurize and heat the laminated film. Such a medium is preferably one that can perform pressurization and heating substantially simultaneously, but a medium that mainly performs pressurization or a medium that primarily performs heating may be used. For example, it is preferable to perform pressurization and heating so that a laminated film of a curable resin film and a mold film is sandwiched between pressurization and / or a heating medium.
As the pressurization and / or heating medium, when the laminated film is sandwiched between the pressurization and / or heating medium, any of the pressurization and / or heating medium arranged so as to be sandwiched is a rotating roll (also simply referred to as “roll”). It is preferable that More preferably, both the pressurizing and / or heating medium is a rotating roll. The curvature radius of the roll is preferably 0.05 m or more. By setting in this way, the production method of the present invention using a mold film is suitable for an industrial production process, and the effects of the present invention are sufficiently exhibited.
In the following, the terms “pressurizing medium” and “heating medium” may be used, but these may be a medium for pressurization or a medium for heating, and a medium for pressurization and heating. It may be. The surface of the rotating roll is preferably flat.

In the embodiment using the pressurizing and / or heating medium, the pressurizing and / or heating medium in contact with the curable resin film A side is referred to as “pressurizing and / or heating medium A”, and the pressurizing and / or heating medium in contact with the surface uneven film B side When the pressure and / or heating medium is “pressurization and / or heating medium B”, at least one of the pressure and / or heating medium A and the pressure and / or heating medium B is preferably an elastic body. In this case, either an elastic body or a non-elastic body may be used, but the surface layer of the pressure and / or heating medium A is preferably in the form of an elastic body. Thereby, elasticity can be given to the surface of the curable resin film A to be transferred, and the occurrence of uneven transfer can be suppressed at each stage. The surface layer of the pressurization and / or heating medium B can transmit the pressure in the transfer to the laminated film more efficiently, and the transferability can be further improved. The surface layer is preferably an inelastic body.
Therefore, when the surface layer of one pressurization and / or heating medium is an elastic body and the other pressurization and / or heating medium is an inelastic body, pressurization and / or heating medium A, pressurization and Either of the heating media B may be an elastic body, but the pressurizing and / or heating medium A in contact with the curable resin film A side is an elastic body, in other words, the curable resin film is an elastic body. It is preferable to contact the surface layer of the pressure and / or heating medium. Each of the pressure and / or heating medium A and the pressure and / or heating medium B is constituted by an elastic body, and there is a pressure and / or heating medium having a high elastic modulus and a low pressure and / or heating medium. In this case, it is preferable that the pressure and / or heating medium A is a pressure and / or heating medium having a low elastic modulus, and the pressure and / or heating medium B is a pressure and / or heating medium having a high elastic modulus. .
A preferred form of the above-described pressurization and / or heating medium, such as the configuration, elastic modulus, and material, is to pressurize and heat by passing between at least two rolls in a state where the following curable resin film and mold film are laminated. This is the same as described in the embodiment.

Moreover, as a preferable form of the said pressurization and a heating process, although mentioned also in the above, (1) It heats, making a heating medium whose surface temperature is 50 degreeC or more contact a curable resin film and a casting_mold | template film, and is curable. A mode in which the surface temperature of the heating medium in contact with the resin film is higher than the surface temperature of the heating medium in contact with the mold film, (2) a mode in which pressurization and heating are performed using a roll as the pressurization and heating medium, 3) Pressurizing and heating by passing between at least two rolls in a state where the curable resin film and the mold film are laminated, and using the surface layer of at least one of the two rolls as an elastic body, Examples include a mode in which the curable resin film is in contact with the surface layer of a roll that is an elastic body, and (4) a mode in which the linear pressure between the rolls is 1 to 100 N / mm. These forms (1) to (4) can be applied to the present invention alone or in combination.

First, the surface temperature of the heating medium is preferably 50 ° C. or higher. By doing in this way, uneven | corrugated shaped transcription | transfer becomes further sufficient and the effect of this invention will be exhibited more. The surface temperature is preferably set to be a substantially constant temperature in the range of 50 ° C. or higher.
Next, assuming that the heating medium in contact with the curable resin film A side is “heating medium A” and the heating medium in contact with the surface uneven film B side is “heating medium B”, the heating medium A in contact with the curable resin film A side. The surface temperature of the heating medium B (hereinafter referred to as Ta) is preferably higher than the surface temperature of the heating medium B (hereinafter referred to as Tb). By making the surface temperature Ta of the heating medium A higher than the surface temperature Tb of the heating medium B, heat can be efficiently transferred to the curable resin film A side where the uneven shape transfer is performed. Thereby, transferability is improved, and the glossiness of the surface of the resulting resin film can be further reduced. If the surface temperature Tb of the heating medium B in contact with the surface uneven film B side is further increased, it is necessary to use a highly heat-resistant mold film. Thus, Ta> Tb is preferable. A more preferable form is that Ta is 20 ° C. or higher than Tb, more preferably Ta is 40 ° C. or higher than Tb, and more preferably Ta is higher than Tb. Is to be higher by 60 ° C. or more. Moreover, regarding the upper limit of Ta, it is preferable that the temperature be 200 ° C. or higher than Tb. More preferably, the temperature is 150 ° C. or higher than Tb. Moreover, it is preferable that the surface temperature Tb of the heating medium B in contact with the surface uneven film B side is not higher than the glass transition point of the material constituting the mold film. More preferably, it is 110 degrees C or less.
The heating medium may be heated by heating at least one heating medium so that it is transferred to another heating medium through the laminated film. For example, heat may be applied only from the heating medium A side, and the surface temperature may be 50 ° C. or higher. In such a case, the surface temperature of the heating medium B is 50 ° C. or higher. It is preferable to make it.

Regarding the heating conditions of the heating medium, for Ta and Tb, (1) When the following curable resin is used as the resin for forming the curable resin film A, Ta and Tb are below the decomposition temperature of the curable resin. Preferably, Ta and Tb are determined so that the temperature difference between Ta and Tb is in the above-mentioned range in consideration of the curing temperature of the curable resin. Ta is usually preferably 300 ° C. or lower, more preferably 250 ° C. or lower, and more preferably 200 ° C. or lower. The lower limit is preferably 100 ° C. or higher.
Tb is usually preferably 50 ° C. or higher, and preferably 100 ° C. or lower.

In the embodiment using the pressure medium (heat pressure medium or pressure medium), a pressure is applied between the pressure medium A and the pressure medium B, whereby transfer is performed. The pressure applied between the heating media is preferably adjusted to be substantially constant between 0.1 and 10 N / mm ² .
When the heating medium has a curved surface shape, preferably when it has a roll shape, it is usually represented by a linear pressure. In the case of a roll shape, the linear pressure is the pressure applied to the place where the two rolls are in contact, that is, the pressure applied to the line in the lateral direction (perpendicular to the rotation direction of the roll) of the roll in contact with the two rolls. It is. In such a form, it is preferable to adjust the linear pressure between rolls between 1-200 N / mm. In order to perform stable and uniform transfer, the linear pressure is preferably adjusted so as to be substantially constant between 1 and 200 N / mm.
If the pressure exceeds the above range, the surface irregularity shape of the mold film as a transfer material may be impaired, and the transferability may not be sufficient. There is a risk that the sex will not be sufficient. More preferably, the upper limit of the linear pressure is 100 N / mm or less, and the lower limit is 5 N / mm or more.
The linear pressure can be calculated from the roll and the load applied to the roll.
Specifically, it can be calculated from the load applied to the effective roll width (contact length between rolls).
For example, if a load of 1000 kg (applied load depends on the setting of the apparatus) is applied to the effective roll width 350 mm, the following is obtained.
When 1000 kg weight is converted into N, it is 9800N. 9800N ÷ 350mm = 28N / mm.
In the case of a thin film, for example, in the case of a film of about 50 μm like this time, even if it is sandwiched between rolls, if the rolls come into contact with each other, the film width is not reached. Therefore, it calculates from the effective width of the roll.

Moreover, in the said pressure heating process, it will be in the state which pressed the heating medium against the laminated | multilayer film, but in order to fully suppress that malfunctions, such as a wrinkle, arise in this laminated | multilayer film at that time. In general, it is preferable to apply tension. In that case, if the resin film and the mold film are laminated in advance and pressed against the heating medium, the tension applied to the laminated film, or the resin film and the mold film pressed against the heating medium separately In the case of laminating at the time of transfer, the tension applied to the resin film and / or the mold film is preferably 0.5 to 50 kg. It is preferable to adjust so as to be substantially constant within this range. A preferred form is to make the resin film and the mold film substantially constant within the above range. If it is less than 0.5 kg, the curl suppression effect after curing may not be sufficient, and the resin film and the mold film may not be laminated properly, resulting in a transfer failure without being laminated neatly. There is a risk. If it exceeds 50 kg, too much tension may be applied and the resin film or the mold film may be broken, and it may be difficult to transfer fine or delicate surface irregularities. The upper limit of the tension is more preferably 20 kg or less, and the lower limit is more preferably 1 kg or more.

Below, the preferable form of the said invention is explained in full detail by making into an example the form pressurized and heated by passing between at least 2 rolls in the state which laminated | stacked the curable resin film and the mold film.
The roll used in the pressurizing and heating step has at least two rolls, and can transfer the uneven shape to the film in which the resin film and the mold film are laminated by the two rolls. Preferably there is. Furthermore, in the present invention, it is preferable to use a roll in which the surface layer of at least one of the two rolls is an elastic body and the surfaces of both rolls can be heated. At least two rolls (transfer rolls) as heating and / or pressurizing media are required, and one pair is used, but a roll having a larger number of rolls may be used. For example, the number of transfer rolls may be further increased, and a resin film, a mold film, a laminated film, and other films may be guided to the transfer roll, or a film having an uneven shape transferred may be pulled out of the transfer roll. Equal rolls may be combined.
In addition, only one pair of transfer rolls constituted by at least two rolls may be used, and the uneven shape transfer may be performed substantially once. Therefore, it may be performed a plurality of times. Thus, the number of transfers is not limited.

In the preferred form, the preferred forms of the elastic body and the non-elastic body in the pressurization and / or heating medium described above can be applied to the two rolls (transfer rolls).
The elastic body can be evaluated as having elasticity, and can compress the pressure applied between the laminated film and the roll when the laminated film of the resin film and the mold film is pressurized. Good. The surface layer of the roll may be made elastic. For example, it is preferable that the elastic roll itself is formed of an elastic body, or only the surface layer of the elastic roll is formed of an elastic body. However, even if the surface layer of the elastic roll is a non-elastic body, the surface layer of the elastic roll is constituted by an extremely thin metal layer, and the pressure applied between the laminated film and the roll by arranging the elastic body inside the surface layer. It may be in a form evaluated that it can be buffered.
Further, the inelastic body can be evaluated as having no elasticity, contrary to the elastic body. When the laminated film of the resin film and the mold film is pressed, the pressure applied between the laminated film and the roll is buffered. It is something that cannot be done.

A preferable form of the elastic body is a form constituted by a material having an elastic modulus at room temperature (25 ° C.) of less than 5 × 10 ⁴ MPa when evaluated by an elastic modulus. The method of measuring the elastic modulus is not particularly limited, but basically, it is evaluated according to the method for obtaining the bending characteristics by three-point bending described in Japanese Industrial Standard (JIS) JIS K 7171: 2008 (Method for obtaining plastic bending characteristics). The bending elastic modulus is an elastic modulus, and it is determined by the same method whether it is an elastic body (elastic modulus <5 × 10 ⁴ MPa) or non-elastic body (elastic modulus ≧ 5 × 10 ⁴ MPa). it can. In addition, since it is difficult to directly evaluate the transfer roll at the time of measurement, a test piece made of the same material as the roll is prepared, and a value obtained by measuring the test piece may be used as the elastic modulus of the roll. In general, it is preferable that the test piece is a plate having a length of 80 mm, a width of 10 mm, and a thickness of 4 mm.
When the elastic modulus is small (for example, less than 10 ² MPa) and it is difficult to obtain a highly accurate elastic modulus value by the above method such as rubber, JIS standard JIS K 6254: 2003 (vulcanized rubber and thermoplastic rubber-low According to the method for obtaining stress / strain characteristics in deformation), the compression modulus can be obtained from the value of force when 20% compression strain is applied, and this can be used as the modulus of elasticity. It is preferable that the test piece has a cylindrical shape recommended by the standard.
In addition, although the JIS standard differs in the measurement method of the elastic modulus depending on the material, even if there is a problem of accuracy, the difference in the value depending on the method is not large, whether it is an elastic body or an inelastic body is a curable resin, It is determined according to JIS K 7171 that is applied to a thermoplastic resin (it can be determined whether or not rubber, resin, metal, and ceramic, which are usually targeted in the present invention, are less than 5 × 10 ⁴ MPa) or more. Thus, if it is difficult to measure an accurate value even if it can be confirmed that it is less than 5 × 10 ⁴ MPa by the same method, it may be obtained by a measurement method suitable for rubber.
The elastic body is preferably a resin material referred to as an elastomer or a polymer compound, but may be an elastic body as a whole even if a non-elastic body is included. In addition, although it is preferable that substantially the whole elastic roll surface is an elastic body, as long as there exists an effect in this invention, a part of elastic roll surface may be a non-elastic body.
For example, phenol resin, urea resin, melamine resin, unsaturated polyester resin, diallyl phthalate resin, epoxy resin, polyurethane, polyimide, polyolefin, polyvinyl chloride, polystyrene, ABS resin, polyamide, (meth) acrylic resin, polycarbonate, polyester, Thermoplastic and thermosetting resins such as aramid resin and silicone resin; natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, butyl rubber, styrene-butadiene rubber, nitrile rubber, epichlorohydrin rubber, urethane rubber, polysulfide rubber, ethylene -Cross-linked rubbers and thermoplastic elastomers made from propylene rubber, acrylic rubber, chlorinated polyethylene rubber, chlorosulfonated polyethylene, fluorine rubber, silicone rubber, phosphazene rubber, etc. Those composed of a rubber such as uncrosslinked rubber is preferred. Moreover, you may make said resin or rubber contain various fillers. Various fillers include carbon powder such as carbon black and graphite, metal salt powder such as calcium carbonate, magnesium carbonate and barium sulfate, metal oxide powder such as clay, talc, silica, titanium oxide, zinc oxide and ferrite, metal Powder; Particles and flakes such as resin powder and vulcanized rubber powder; Single fiber such as glass fiber, ceramic fiber, carbon fiber, metal fiber, resin fiber such as cellulose, nylon, polyester, and the like.

In addition, as for the said elastic roll, a surface layer should just be an elastic body as above-mentioned, and the material of what is called a core material of a roll is not specifically limited. Examples of the material of the core include non-elastic bodies such as metals described later. Examples include a form in which a resin sheet is attached to the surface of a metal roll (cylinder).

A preferable form of the inelastic body is a material having an elastic modulus at room temperature (25 ° C.) of 5 × 10 ⁴ MPa or more when evaluated by an elastic modulus. In this way, the non-elastic body does not have to be strictly inelastic, and can be evaluated as being incapable of buffering the pressure applied between the laminated film and the roll, contrary to the elastic body. is there. Examples thereof include inorganic glass, metal oxides, metal (acid) nitrides, metal (acid) carbides, ceramics such as metal (acid) sulfides, carbon materials, and metal materials such as SUS.

Next, the suitable transfer conditions in the preferable form of the present invention, that is, the relationship between the laminated film and the transfer roll, and the setting in the transfer roll will be described.
In a preferred form of the pressurizing and heating step, pressure is applied between the transfer rolls, whereby transfer is performed. The pressure applied between the transfer rolls, that is, the linear pressure is at least two rolls. These are referred to as heating medium A and heating medium B, respectively, and the preferred form of the pressure between the heating media described above may be applied. In addition, a laminated film obtained by laminating a resin film and a mold film as essential components on the transfer roll is supplied, and the preferred form of the pressure of the heating medium described above may be applied to this.
The supply speed of the resin film and / or the mold film to the transfer roll and the supply speed of the laminated film to the transfer roll in the pressure heating step are 0.3 to 10 m / min. (Minutes) is preferred. It is preferable to adjust so as to be substantially constant within this range. As a preferable mode, the resin film and the mold film have substantially the same speed and are substantially constant within the above range. 10 m / min. If it exceeds 1, the speed is too high and transfer cannot be carried out sufficiently, transferability is poor, and there is a possibility that the image will not be transferred cleanly. 0.3 m / min. If it is less than the range, productivity may be inferior. More preferably, the upper limit of the speed is 8 m / min or less, and the lower limit is 0.5 m / min.

In the preferred embodiment of the present invention, the surfaces of both rolls are heated. In such a form, each of at least two rolls may be the heating medium A and the heating medium B, and the heating method for the heating medium described above may be applied. When the transfer roll is composed of more rolls, it is preferable to heat at least two rolls that contribute most to the transfer. However, the transfer roll 2 is heated so that the effect of the present invention is exhibited. A book roll or a larger number of rolls may be appropriately selected and set.
In the above preferred embodiment, it is preferable that the surface temperature of both of the two rolls is 50 ° C. or higher so that the surface temperature of the roll in contact with the resin film is higher than the surface temperature of the roll in contact with the mold film. It is. When the transfer roll is constituted by two rolls, it is preferable that both of the two rolls are set as such, and when constituted by a plurality of rolls, at least two of the rolls are set. It is preferable to set the surface temperature of the roll as described above. What is necessary is just to set the surface temperature of several transfer rolls or all the transfer rolls most important for transfer as mentioned above.
The surface temperature of the roll here is a temperature obtained by actually measuring the surface temperature with a surface thermometer or the like. An example of the method for measuring the surface temperature is a contact-type surface thermometer.

As a preferred embodiment of the present invention, the surface layer of the roll A is an elastic body, the surface layer of the roll B is an inelastic body, and the surface temperature of the roll A is higher than the surface temperature of the roll B. The form whose surface temperature of B is 50 degreeC or more can be mentioned.
An example of the method for producing the resin film of the present invention is shown in FIG. In FIG. 1, a rubber roll 1 is used as a roll whose surface layer is an elastic body, and a SUS roll 2 is used as the other of the two rolls. The curable resin film 3 is in contact with the rubber roll, the mat film 4 used as a mold film is in contact with the SUS roll, and the curable resin film 3 and the mat film 4 are passed in a state where the two rolls are laminated. . At this time, as shown in FIG. 1, the curable resin film 3 and the mat film 4 may be laminated when passing between the two rolls, and are laminated in advance before passing between the rolls. It is good also as a done state.
Moreover, after passing between two rolls, the form from which the curable resin film 3 and the mat | matte film 4 peel immediately as FIG. 1 may be sufficient.
In this embodiment, the linear pressure that is the pressure applied between the transfer rolls, the tension applied to the curable resin film and the mold film, the supply speed of the curable resin film and the mold film to the transfer roll, and the surface temperature of the transfer roll are the above preferred forms. If set as above, the effect of the present invention can be remarkably improved.

Below, the component which forms a resin film, the curable resin film | membrane, a mold film, the use of a resin film, etc. are explained in full detail.
The resin constituting the cured resin film produced in the production method of the present invention is a curable resin cured product. In the technical field of the cured resin film produced according to the present invention, especially in optical members and the like, there is a growing demand for higher functionality and higher added value through downsizing, thinning, and weight reduction. In order to reduce the cost and the like, it has been studied to assemble optical / electronic members such as a digital camera module and a lens unit by a reflow process. As described above, the reflow process is a process in which soldering is performed by applying heat to the entire member after assembling the member, thereby enabling automatic mounting and lowering the manufacturing cost. Can do. In this case, an optical member such as a light-shielding film having a plurality of minute surface irregularities having excellent heat resistance and reflow resistance (withstanding reflowable specifications) is required.
Thus, in order to obtain a cured resin film that can withstand the reflowable specification, it is effective to use a cured resin film formed from a curable resin composition having high performance such as heat resistance. In the present specification, the curable resin cured product is obtained by curing or semi-curing the curable resin. For example, a form having a crosslinked structure formed by crosslinking the curable resin is one of preferable forms. It is.

In the field of optical members such as lens units, glass lenses are becoming resinous, and plastic lenses such as PMMA / PC and polycycloolefin are being used instead of inorganic glass. There is a need for a plastic lens with excellent heat resistance that can withstand reflowable specifications, but in connection with this, the heat resistance of various members such as a light-shielding film having a plurality of minute surface irregularities may be improved. If possible, a reflow process can be performed on the camera module or the like, and the optical member can be reduced in size, thickness, and weight. It can be expected that this will further promote the glass lens resinization.

In the production method of the present invention, the surface of the curable resin film formed from the curable resin composition is formed by forming a surface uneven shape by transfer, and the curable resin film is produced. Uses a composition in which the curable resin composition is in an intermediate state (semi-dried, semi-solidified, semi-cured or unreacted / semi-reacted).
The curable resin film is dried, for example, after a curable resin composition is applied to a substrate by a normal application method, or after being formed into a film shape by a film (film) formation method such as melt extrusion molding. , Solidifying, curing, or reacting (reacting from a precursor or monomer to a resin state). For example, a curable resin is formed by applying a curable resin solution such as a polyamic acid solution or an epoxy compound to a base material, drying it, and then peeling it from the base material to form a single layer film made of an uncured / semi-cured curable resin. It can be used as a film.
As the curable resin film A (also referred to as curable resin film A), a film obtained by forming a film of a curable resin composition (also referred to as a curable resin solution) on a substrate can be used. . Specifically, the curable resin composition is applied to a substrate and dried, and then peeled off from the substrate to form a single layer film made of an uncured, semi-cured curable resin, or a substrate What was made into the laminated | multilayer film of uncured and semi-hardened curable resin and a base film without peeling is mentioned.
Examples of the curable resin composition include a polyamic acid solution and a composition containing a polyfunctional epoxy compound and a cationic curing agent. By curing these curable resin compositions, the resulting cured resin film will contain a polyimide resin, a polyamideimide resin, or a cationically cured resin.

In the production method of the present invention, transfer is performed, and the curable resin composition is brought into contact with a mold film having irregularities to form an irregular shape. For example, after applying a curable resin composition to a mold film, it is formed into a film, or optionally dried and solidified, or cured or reacted (for example, a reaction of polyamic acid to make a polyimide) to form a film, An example is a method of forming an uneven shape (transfer method 1). In this case, the mold film is preferably a mat film (surface irregular PET or the like). In addition, the curable resin composition is formed into a film in advance, and the film is chemically or compositionally intermediate, or semi-dried, semi-cured, or unreacted / semi-reacted, and then the film. There is a method (transfer method 2) in which irregularities are formed by bringing a formed film into contact with a mold film. In this case, the mold film is preferably a mat film (surface irregular PET or the like). That is, a method of forming irregularities by bringing a curable resin composition previously formed into a film shape into contact with a mold film as in the transfer method 2 is also a preferable transfer.

In the transfer method 1, the concavo-convex shape is formed before or in the course of drying / solidifying, curing, or reacting the curable resin composition.
In any of the above transfer methods 1 and 2, a liquid composition can also be suitably used. That is, as performed in the transfer method 1, it is one of the preferable embodiments that the surface unevenness forming step includes a step of forming a film made of the curable resin composition on the mold film.
As the film forming method in forming the concavo-convex shape in the transfer method 1 and forming the film to be transferred in the transfer method 2, the solvent cast method, spin coating method, bar coater method, roll coater method, gravure coater method, knife A conventionally known coating method such as a coating method may be employed.

In the above transfer method 2, the curable resin composition is formed in a film shape in advance, and the film is chemically or compositionally intermediate, or semi-dried, semi-cured, or unreacted / half-reacted Then, the film-like shape is brought into contact with the transfer layer to form a concavo-convex shape. Therefore, a drying / solidifying or curing step is not necessarily required in the process of forming the uneven shape. Moreover, in the transfer method 2, after forming an uneven | corrugated shape, you may dry, solidify, or harden | cure, and you may dry, solidify, or harden | cure, forming an uneven | corrugated shape. From the viewpoint of more following the uneven shape of the transfer layer, it is preferable to dry, solidify or cure while forming the uneven shape. In the transfer method 2, the curable resin composition is semi-dried and semi-cured beforehand if the curable resin composition provided to the transfer method 2 is in contact with the transfer layer so that an uneven shape can be formed. Say what you want.
In the transfer method 2, when semi-drying and semi-curing in advance, the curable resin composition may be applied on the above-described base material and semi-drying and semi-curing.
A form in which the transfer method 1 and the transfer method 2 are combined (also referred to as a transfer method 3) is also preferable, whereby uneven shapes can be formed on both sides of the film. For example, after preparing a curable resin film by applying a curable resin composition to a mold film by the transfer method 1, the other side of the curable resin film is brought into contact with the mold film by the transfer method 2 to obtain a cured resin. Both sides of the film can be roughened. Alternatively, after the curable resin film is prepared by the transfer method 2 and brought into contact with the mold film, the other surface of the curable resin film is further brought into contact with the mold film by the transfer method 2. In such a double-sided unevenness forming method, pressure and heating are performed with one side of the curable resin film laminated with the mold film, preferably with both sides of the curable resin film laminated with the mold film. Will be given.

In the transfer method 3, when the transfer methods 1 and 2 are continuously performed, a mode in which the other transfer method is performed immediately after performing one transfer method is preferable. There may be a certain period until the transfer method is performed. Such a time interval can be appropriately selected depending on the material used and the like, and when making unevenness continuously on both surfaces of the cured resin film, the time interval in the production method that is usually used is preferably used. Can do.
When the transfer methods 1 and 2 are continuously performed, a mode in which the transfer method 2 is performed after the transfer method 1 is performed is preferable. For example, the transfer method 1 forms an unevenness on one surface of the cured resin film and the curable resin composition is semi-dried, semi-cured, or dried, solidified, or cured, and then transferred. By Method 2, an uneven shape can be formed on the other surface. Thus, the form in which the surface unevenness forming step is based on the transfer method 3 is also a preferred form of the present invention.

The transfer methods 1 to 3 can be used by appropriately selecting one or two or more according to the curable resin composition, the cured resin film to be produced, and the like. Among these, the formation of a stable concavo-convex shape (low deflection), the formation of a uniform and fine concavo-convex shape, the superiority of the size and form controllability of the concavo-convex shape, and the ability to impart matting properties while being excellent in flatness And the method of 3 is preferable.
In the above transfer methods 1 to 3, the base material and / or the mold film may be integrated with the curable resin composition in the step of forming the concavo-convex shape. It may be laminated with a cured resin film, and the substrate and / or the mold film may be removed. Usually, a casting_mold | template film will be removed (peeled off), and a base material will be removed as needed. In the above transfer method 1 or 3, when the substrate is removed, a cured resin film having a single layer of cured resin and having a concavo-convex shape on the surface is obtained. Thus, it is possible to realize the formed uneven shape forming film.

In the case of removing the substrate, it is preferable to have excellent mold release properties in order to separate the cured resin film after the formation of the unevenness. In addition, the curable resin composition is applied to a smooth substrate, and the semi-dried to dry, semi-solidified to solidified, semi-cured to cured, or peeled off from the precursor in a curable resin film state, It is also preferable to form a concavo-convex shape by the transfer method 2.

In the transfer described above, the mold film is to form a surface uneven shape on the surface of the curable resin film, and the form is not particularly limited as long as the surface uneven shape is formed on the surface, For example, various forms, such as a film form (for example, mat film), can be used. As the material of the mold film, frosted glass; matte films (matte treated polymer films) such as matte treated PET films (matte pet films), matte treated PP films, and matte PC films are suitable. As the uneven characteristics of the mat film, preferably Ra is 1.0 μm or more, Ry is 10 μm or more, Rz is 10 μm or more, S is 3 μm or less, more preferably Ra is 1.5 μm or more, Ry is 20 μm or more, Rz is 15 μm or more and S is 2 μm or less.

Examples of suitable manufacturing processes of the present invention include the following forms. That is, peeling from the base material etc. after film-forming of a curable resin film may be performed after forming surface uneven | corrugated shape, and may be performed before forming surface uneven | corrugated shape. That is, the form which performs uneven | corrugated formation in this invention on the single layer film of a curable resin film may be sufficient, and it is good also as a single layer film after performing the uneven | corrugated formation in this invention. Specifically, (1) a curable resin composition (also referred to as a curable resin solution) is formed on a substrate, and the curable resin film is peeled off from the substrate to form a single layer film. A surface uneven shape is formed on the surface of a cured or semi-cured curable resin film (cured resin film A) by the above-described process (also referred to as laminating treatment), and cured by heating or irradiation to be cured. Forms for obtaining a resin film, (2) After forming a concavo-convex shape on the surface of an uncured or semi-cured curable resin film by the above-described process on a substrate, etc. It is the form which peels from a base material etc., obtains a single layer film, is hardened by irradiating with a heating or light, and obtains a cured resin film.

As a preferable form of the present invention, it is also preferable that a concavo-convex shape is formed on the surface of the curable resin film opposite to the surface in contact with the mold film by transfer. This includes the following forms (A), (B) or (C).
As described above, an uneven shape may be formed on one surface of the resin film by the manufacturing method of the present invention, or an uneven shape may be formed on both surfaces. A manufacturing method in which the manufacturing method of the present invention is applied to both surfaces of the resin film, a manufacturing method in which the manufacturing method of the present invention is applied to one surface of the resin film, and a concave and convex shape is formed on the other surface by another manufacturing method. It is done. In any case, at least one surface of the resin film has an uneven shape formed by the production method of the present invention, and the effects of the present invention can be achieved. Thus, by forming uneven shapes on both sides, the light-scattering property of the resulting cured resin film can be increased, the glossiness can be lowered, and the light-shielding property can be enhanced when a light-shielding film is formed. .
As a specific method for forming the concavo-convex shape on both sides with the surface concavo-convex forming method according to the manufacturing method of the present invention as an essential method, (A) a method performed only by the manufacturing method of the present invention (double-sided concavo-convex forming method A), (B ) After carrying out the manufacturing method of the present invention, a method of performing a post-process (double-sided unevenness forming method B), (C) Resin film having an uneven shape formed on one surface by any method by a method different from the present invention A method of applying the manufacturing method of the present invention (double-sided unevenness forming method C) to the other surface of the above can be mentioned. These double-sided unevenness forming methods will be described below.

Furthermore, if a specific form is mentioned about the double-sided uneven | corrugated formation method, it will become as follows.
In the case where both sides of the surface are roughened only by the transfer method according to the present invention, the transfer method 3 is opposite to the case where the curable resin film is formed on the mold film a by the coating method (the mold film a remains laminated). A mode in which the mold film b is laminated on the surface and used as a pressure heating medium (a mode in which the transfer methods 1 and 2 are performed simultaneously, also referred to as a transfer method 3-1) is a preferable method. In addition, a curable resin film formed on the mold film a by a coating method (while the mold film a is laminated) is applied to a pressurized heating medium (transfer method 1), and then the mold film b on the opposite surface. (Transfer method 2) (also referred to as transfer method 3-2).
Further, as a form in which the transfer method 2 is simultaneously applied to both surfaces, a form in which a curable resin film is sandwiched between mold films and used as a pressure / heating medium (also referred to as a transfer method 2-1) is a suitable method. .
Further, as a form in which the transfer method 2 is sequentially applied to each side, after forming a curable resin film, the mold film a is laminated and used for a pressure heating medium (transfer method 2). There is a form (transfer method 2) (also referred to as transfer method 2-2) that is used for a pressure heating medium in a state where the film b is laminated.
On the other hand, it is good also as a form which combines the transfer method 1 or 2 and another method, As a different method, the form which uses a mat roll preferably is mentioned.
In the surface unevenness forming step in the present invention, it is essential to use a mold film for the transfer layer for forming the unevenness. However, in the embodiment in which the uneven shape is formed on both surfaces of the film as described above, one surface is formed by a mat roll. Concavities and convexities may be formed. As a form using a mat roll, the form combined with the transfer method 1 or 2 using a casting_mold | template film is mentioned.
For example, when a film formed by coating on a mold film (transfer method 1) is passed between heated and pressurized rolls, a roll on the non-contact surface side of the mold film is used as a mat roll, After passing the film formed by coating (transfer method 1) between heating and pressurizing rolls (transfer method 1), as a next step, preferably as a continuous next step, a mold film non-contact Specific examples include a method of performing a mat roll treatment on the surface side, a method of performing a mat roll treatment on a surface which is not formed with unevenness on the curable resin film obtained by the transfer method 2, and the like.
Among the above-described methods for forming irregularities on both sides, forms in which irregularities are formed in stages (from the formation of surface irregularities on the first stage to the formation of surface irregularities on the second stage, such as transfer methods 3-2 and 2-2, mat rolls) Etc.)), the form of the curable resin film to be used for the formation of the surface unevenness of the second stage is such that the mold film on the side where the unevenness formation by the mold film has already been performed remains laminated, A single layer state in which the mold film is separated (peeled) may be used.
The production method of the present invention is essential, and it is suitable for providing a concave and convex shape having a fine size on both sides and having a certain size, that is, a method using a mold film, that is, the transfer method 3- 1. It is considered that the transfer method 2-1. More preferably, the transfer method 3-1 is applied to the transfer method 2-1.
The form in which the transfer method 1 or 2 and the other method are combined is a preferred form both in the above meaning and in the sense of excellent productivity.
These exemplify the embodiment of the double-sided unevenness forming method, and are a preferable form combined with the manufacturing method of the present invention in double-sided unevenness forming.
In addition, about the technical background that it is preferable to form unevenness on both surfaces, and preferable forms resulting therefrom, it is as shown in the following 1) to 3).
That is, 1) In the (semi) transparent light scattering film such as a light diffusion film, the light scattering (diffusion) effect on each surface acts synergistically by forming irregularities on both surfaces. The light scattering (diffusion) performance is superior to a film having an uneven surface only on one side.
The light-shielding film is required to be used for an optical element, particularly for use in an imaging lens unit. However, for such an optical element, both surfaces need to have low gloss. .
2) The fact that the surface irregularities are fine and the size is uniformly controlled is excellent in light scattering performance (both transparent and light-shielding bodies) for visible light.
3) For the reason of the above 2), it is a method using a mold film on both sides that is suitable for providing a concave-convex shape having a fine size on both sides and having a certain size. Specifically, The transfer method 2-1, 2-2, 3-1, 3-2 described above.
Therefore, also when forming uneven | corrugated shape on both surfaces of a film surface, it is preferable to apply the manufacturing method of this invention using a mold film to both surfaces, or to combine with the method using the mold film mentioned above.

As a preferable form of the production method of the present invention, it is preferable that the curable resin composition contains a black material in that light-shielding properties can be imparted to the resulting cured resin film. When the curable resin composition contains a black material, the curable resin film A formed from the curable resin composition becomes a black film. A manufacturing method in which the obtained cured resin film is a light-shielding film and the light-shielding film is used for a lens unit for an image sensor is also a preferred embodiment of the manufacturing method of the present invention. The black material, the light shielding film, and the lens unit for the imaging element will be described in detail later.

Since the cured resin film produced by the method for producing a cured resin film has surface irregularities on the film surface, the cured resin film can be made glossless, prevent reflection of light, and can be shielded from light. Such a cured resin film produced by the above production method is also one aspect of the present invention. It is preferable that at least one surface of the cured resin film has a concavo-convex structure. By having such a concavo-convex structure, gloss of the cured resin film can be eliminated, light reflection can be prevented, and light can be shielded. Thus, it is effective to have a concavo-convex structure on at least one surface of the cured resin film surface in order to control the glossiness of at least one surface of the cured resin film to 20 or less. The cured resin film preferably has a glossiness of 20 or less. When the glossiness of the cured resin film exceeds 20, light shielding is not sufficient and, for example, when used as a lens unit, it may cause malfunction as noise. More preferably, it is 10 or less, More preferably, it is 5 or less. The glossiness is measured at a measurement angle (θ) of 60 degrees using a gloss meter VG-2000 manufactured by Nippon Denshoku Industries Co., Ltd.

The concavo-convex structure of the cured resin film may be such that the surface is not smooth to the extent that incident light is scattered without being specularly reflected. Moreover, it is preferable that the unevenness | corrugation of the surface is a magnitude | size suitable for scattering the light which it wants to shield. For example, when a cured resin film is used for a lens unit, it effectively scatters light in the visible light region, the ultraviolet region, the infrared region, and the like.

In a preferred form of the height of the concavo-convex shape, Ra (arithmetic mean roughness) of the film line roughness (JIS B0601-1994) is 0.3 μm or more. More preferably, it is 0.5 μm or more, still more preferably 1.0 μm or more, and particularly preferably 2.0 μm or more. The upper limit of Ra is preferably 10 μm or less. More preferably, it is 8 micrometers or less, More preferably, it is 5 micrometers or less. As for the ten-point average roughness Rz of the uneven shape, the lower limit is preferably 5 μm or more. More preferably, it is 10 micrometers or more, More preferably, it is 15 micrometers or more, Most preferably, it is 20 micrometers or more. The upper limit of Rz is preferably 100 μm or less. More preferably, it is 70 micrometers or less, More preferably, it is 50 micrometers or less. Regarding the average interval S between the local peaks in the concavo-convex shape, the upper limit is preferably 20 μm or less. More preferably, it is 10 micrometers or less, More preferably, it is 5 micrometers or less. Moreover, about the preferable form of a minimum, 0.1 micrometer or more, 0.5 micrometer or more, 1 micrometer or more is mentioned.

Next, a method for determining the arithmetic average roughness, the ten-point average roughness, the average interval, and the like will be described with reference to FIG. FIG. 3 is a model cross-sectional view of the concavo-convex shape on the film surface, where the X axis is a line drawn in the horizontal direction with respect to the film surface, and the Y axis is a line drawn in the direction perpendicular to the film surface. Yes, this Y axis represents the height direction. In this figure, the line along the concavo-convex shape is called the roughness curve f, and the line drawn along the film surface at the average value of the height on the Y axis of the roughness curve f at the reference length (l). This is called the average line m, which is the X axis. This also applies to FIG. 4 and FIG.

As shown in FIG. 3, the arithmetic average roughness Ra is obtained by extracting only the reference length (l) from the roughness curve f in the direction of the average line m, and setting the X axis in the direction of the average line m of the extracted portion. Taking the Y axis in the direction perpendicular to the X axis, the roughness curve f is expressed as y = f (x)
The value obtained by the following formula is expressed in micrometers (μm).

In the formula, l indicates a reference length. Here, a region indicated by a plurality of vertical lines in FIG. 3 is a region surrounded by the roughness curve f and the average line m (a straight line of X = 0 or X = 1 and the roughness curve f intersect). In the portion, a region surrounded by a roughness curve f, an average line m, and X = 0 or X = 1 and a valley region in the negative direction of the Y axis is shown.
The areas indicated by the plurality of diagonal lines in FIG. 3 are equal to the total area of the areas indicated by the plurality of vertical lines. At this time, a plurality of regions indicated by diagonal lines are surrounded by straight lines of X = 0, X = 1, Y = Ra, and Y = 0.

As the ten-point average roughness Rz, as shown in FIG. 4, only the reference length (l) is extracted from the roughness curve f in the direction of the average line m, and the direction perpendicular to the average line m of the extracted portion is obtained. The average value of the absolute value of the elevation (Yp) from the highest peak to the fifth peak in the order of height (in order of increasing positive value on the Y axis) and the lowest peak from the lowest valley (Y The sum of the absolute values of the altitudes (Yv) of the valley valleys up to the fifth in the descending order of the negative numerical value of the axis is obtained, and this value is expressed in micrometers (μm). That is, the following formula:
Rz = (| Yp1 + Yp2 + Yp3 + Yp4 + Yp5 | + | Yv1 + Yv2 + Yv3 + Yv4 + Yv5 |) / 5
Is required. In the formula, Yp1 + Yp2 + Yp3 + Yp4 + Yp5 represents the sum of elevations from the highest summit to the fifth summit of the extracted portion with respect to the reference length (l), and Yv1 + Yv2 + Yv3 + Yv4 + Yv5 is the lowest valley bottom of the extracted portion with respect to the reference length (l). Indicates the total elevation of the bottom from the 5th to the 5th.

As shown in FIG. 5, the average interval (S) between the local peaks is extracted from the roughness curve f in the direction of the average line m by a reference length (l), and the adjacent local peaks in the extracted portion are adjacent to each other. The length of the corresponding average line m (referred to as the interval between the local peaks) is obtained, and the arithmetic average value of the intervals between the numerous local peaks is represented. In Japanese Industrial Standard (JIS) B0601-1994, (S) is expressed in millimeters (mm), but in the present invention, it is determined in units of micrometers (μm). That is, it is obtained by the following formula.

In the formula, Si represents the interval between the local peaks, and n represents the number of the intervals between the local peaks within the reference length.

Although it does not specifically limit as long as it has the unevenness | corrugation of the structure mentioned above, It is preferable that the unevenness | corrugation is formed, without containing fine particles other than black fine particles in a cured resin film. When the irregularities are formed by containing fine particles, the fine particles are usually white or light-colored fine particles, so that the fine particles existing in the vicinity of the surface of the cured resin film serve as a light transmission path. When making a cured resin film excellent in heat resistance, heat resistance is also required for the fine particles to be used. However, if white (or light) fine particles having high heat resistance such as spherical silica and silicone resin particles are used, it is excellent. It may be a blackening inhibition factor for obtaining a good light shielding property. Furthermore, in order to obtain sufficient light-shielding properties, it is necessary to add a large amount of black fine particles, which is disadvantageous for the formation of uniform unevenness on the surface. Further, when forming irregularities using fine particles, particles having a uniform particle size distribution are necessary for forming uniform irregularities, which may be expensive.
The cured resin film preferably has an uneven structure on at least one side. More preferably, it has an uneven structure on both sides. By having a concavo-convex structure on both sides, the above-described effects are sufficiently exhibited.

Hereinafter, the curable resin composition used as the curable resin film of the present invention and the curable resin composition that is a raw material for forming the curable resin constituting the curable resin film (the curable resin raw material before curing and other curable resin materials). The composition containing the components) will be described in more detail. As described above, in the method for producing a cured resin film of the present invention, the cured resin included as an essential component includes a cured curable resin.

Unlike the cured resin which comprises a cured resin film, the curable resin raw material in the said curable resin composition is a precursor or a monomer. For example, when the curable resin raw material is an epoxy resin that is a curable resin, the following forms are exemplified. When curable resin which comprises the said cured resin film is a cationic cured epoxy resin, a polyfunctional epoxy compound is mentioned as a curable resin raw material. In addition, when the curable resin composition contains a curing agent such as an acid anhydride, a polyvalent amine, or a polyhydric phenol in addition to a curable resin raw material such as a polyfunctional epoxy compound, these curing agents are also cured. It is a basic resin material. In addition, it is a preferable form as curable resin composition that the curable resin composition contains a cationic curing catalyst.

Examples of the curable resin include a resin curable by ultraviolet irradiation (ultraviolet curable resin), a resin curable by heating (thermosetting resin), a resin curable by electron beam irradiation (electron beam curable resin), and light. Any resin that cures upon irradiation of (a photocurable resin) may be used. Among these, a thermosetting resin is preferable, and thereby, reflowable characteristics can be made sufficient. In this case, a large heat shrinkage is caused when the thermosetting resin is cured, but the production method of the present invention generates curls due to such a heat shrinkage and a volatile component usually contained in the thermosetting resin. Curling due to influence can be sufficiently suppressed.
The molecular weight before curing of such a curable resin is not particularly limited, and a resin having a high molecular weight to an oligomer can be used. As the form of the resin raw material containing the curable resin, for example, (1) a form made of a liquid or solid curable resin, (2) a liquid or solid curable resin, and a lower molecular weight than the curable resin A form containing a curable compound or a solvent (non-curable), and (3) a form containing a liquid or solid non-curable resin and a curable compound having a lower molecular weight than the non-curable resin, etc. Is mentioned. Examples of the form containing (3) a liquid or solid non-curable resin and a curable compound having a lower molecular weight than the non-curable resin include an oligomer component of an acrylic resin such as PMMA, a (meth) acrylate monomer, and the like. The form to contain can be mentioned.

As the curable resin, for example, a compound having at least one epoxy group, a polyhydric phenol compound, a compound having a polymerizable unsaturated bond, and the like can be suitably used. It can also be used as a mixture of the above. Among these, it is preferable to have at least one epoxy group. By having at least one epoxy group, heat resistance comparable to that of inorganic glass is exhibited, and excellent properties such as excellent molding and workability can be exhibited. A compound having at least one epoxy group, a polyhydric phenol compound, and a compound having a polymerizable unsaturated bond that can be suitably used as the curable resin of the present invention will be described in detail later.
The epoxy group is an organic group having an oxirane ring, and an organic group having an oxirane ring such as a glycidyl group includes an epoxy group. Therefore, the compound having an epoxy group includes a compound having a glycidyl group. It is also a preferred embodiment that the compound having at least one epoxy group is a compound having at least one glycidyl group. Furthermore, it may have a plurality of epoxy groups, and in addition to the glycidyl group, an epoxy group different from the epoxy group possessed by the glycidyl group may coexist.

As the curable resin, an epoxy resin raw material, a poly (amide) imide resin raw material, or the like can also be suitably used. Epoxy resin is preferable because it is a heat-resistant resin having a high Tg, and optical characteristics, in particular, low transmittance wavelength dependency. Poly (amide) imide resin is a heat-resistant resin having a Tg of 150 ° C. or higher. It is preferable from a certain point. In addition, Tg of curable resin hardened | cured material, such as an epoxy resin and poly (amide) imide resin, means Tg in hardened | cured material after hardening. The Tg of the cured curable resin after curing the curable resin is not particularly limited, but is preferably 100 ° C. or higher from the viewpoint of heat resistance. More preferably, it is 120 degreeC or more, More preferably, it is 150 degreeC or more.
The poly (amide) imide resin may be a curable resin cured product or a thermoplastic resin, and may be used as a thermoplastic resin or a curable resin as appropriate. The poly (amide) imide resin will be described in detail later.
In the present invention, poly (amide) imide resins that are preferable as the resin of the resin film include those that do not melt even when heated at a temperature of 400 ° C. or lower, and those that can melt. In the poly (amide) imide resin in the specification of the present application, the former (one that does not melt even when heated at a temperature of 400 ° C. or less) is a curable resin cured product, and the latter (one that can be melted by heating at a temperature of 400 ° C. or less) ) Is called a thermoplastic resin. In the description of the poly (amide) imide resin, the former material (which does not melt even when heated at a temperature of 400 ° C. or lower) is obtained when speaking of the raw material of the curable resin or the curable resin cured product. The raw material for obtaining the latter thermoplastic poly (amide) imide resin means the raw material for obtaining the latter thermoplastic poly (amide) imide resin.

The cured resin film produced by the method for producing a cured resin film of the present invention contains at least one selected from the group consisting of a poly (amide) imide resin, a polyamideimide resin, and a cationic cured resin in terms of heat resistance. It is preferable to do.

The cured resin film produced by the method for producing a cured resin film of the present invention preferably contains a black material. The said black material gives light-shielding property to the cured resin film manufactured by the manufacturing method of the cured resin film of this invention, and can use various black materials. As content of the black material in the said cured resin film, it is preferable that it is 1-50 mass% in a total of 100 mass% of a black material and cured resin. If it is less than 1% by mass, the light-shielding property may not be sufficient, and if it exceeds 50% by mass, the viscosity of the curable resin composition is too high to handle and the film may break after film formation. There is. More preferably, it is 3-40 mass%, More preferably, it is 5-30 mass%.
The black material is preferably present by being dispersed or dissolved in the curable resin composition. When it does not exist in a dispersed or dissolved state, the cured resin film is not uniformly black, and there is a possibility that a sufficiently excellent light shielding property is not exhibited. That is, the cured resin film of the present invention is preferably obtained using a curable resin composition obtained by dispersing or dissolving a black material in a curable resin material (resin binder).

Examples of the black material include carbon black fine particles such as carbon black and graphite; inorganic black fine particles such as metal oxide black fine particles such as titanium black; black organic fine particles such as aniline black (organic black fine particles); etc. Black fine particles, anthraquinone, indigoid, diazo black organic dye, and the like can be suitably used. The inorganic black fine particles (inorganic black material) include magnetite, cuprous oxide (cuprous oxide), composite oxide black fine particles containing copper and chromium as main metal components, copper, other than the above titanium black, copper Complex oxide black fine particles containing copper and iron as main metal components, composite oxide black fine particles containing copper, iron and manganese as main metal components, and complex oxide black fine particles containing cobalt, chromium and iron as main metal components Etc. is also one of the preferred forms.
Among the black materials, a fine particle black material (black fine particles) is preferable, and various black fine particles can be used. Among the black fine particles, carbon black fine particles and inorganic black fine particles are preferable in terms of excellent heat resistance. A carbon-based material such as a carbon-based fine particle is preferable in terms of excellent light-shielding performance in the visible light region, and can be imparted with a uniform black color to the cured resin film by being ultrafine and having excellent dispersibility in the cured resin. Carbon black is more preferable. In addition to excellent heat resistance, carbon black is preferable because it has a high degree of black and is inexpensive.

The black fine particles preferably have a primary particle diameter of 1 μm or less. More preferably, it is 0.1 μm or less. Moreover, the particle | grains by which secondary aggregation was suppressed are preferable. Further, when the black fine particles are dispersed in the cured resin, it is preferable that the black fine particles have a particle diameter of 1 μm or less. The particle diameter of the black fine particles when dispersed in the cured resin is more preferably 0.5 μm or less, and still more preferably 0.1 μm or less. When the black fine particles are dispersed in the cured resin, the hue (black) becomes uniform when the black fine particles are dispersed with a fine particle diameter. In addition, when the treatment for forming irregularities on the surface of the cured resin film is performed, if the black fine particles have a particle size of 1 μm or less, there is no generation of defects due to the coarse particles of the black fine particles, and workability is improved. Excellent.
The primary particle diameter can be measured by a transmission electron microscope image.
The black fine particles may exist in such a way that the primary particles exist independently without secondary aggregation or association, or the primary particles form a structure in which the primary particles aggregate in one, two, or three dimensions. The said primary particle diameter means the magnitude | size of a primary particle in any case. For example, when the black fine particles are carbon black, the particle diameter in the case where the primary particles are almost spherical or granular (has a contour due to microcrystals and is more difficult to be divided).
The size of the primary particles can usually be measured by a transmission electron microscope image, and the number average value (average primary particle diameter) is more preferably in the above range. In determining the average primary particle size, it is preferable to measure the size of 20 or more primary particles and determine the average of the measured values.
In addition, when it is difficult to measure the size of the primary particles by a transmission electron microscope image, E. T. T. et al. Specific surface area diameter (μm) = 6 / (ρ × S) that can substitute the specific surface area diameter calculated by the following formula using the specific surface area value measured by the method as the average primary particle diameter
(In the formula, ρ represents the true specific gravity. S represents the specific surface area (m ² / g).)
Moreover, the particle size of the black fine particles when dispersed in the cured resin composition is measured by using a dynamic light scattering type particle size distribution measuring device such as LB-500 (manufactured by Horiba). In the present invention, an arithmetic average value based on volume is adopted.

When the black fine particles are carbon black, dibutyl phthalate oil absorption can be used as a dispersibility index. The oil absorption is preferably 300 ml / 100 g or less. Thus, a cured resin film in which the black fine particles contain carbon black having an oil absorption of 300 ml / 100 g or less is also a preferred embodiment of the present invention. When the oil absorption exceeds 300 ml / 100 g, the dispersibility of the carbon black is deteriorated, the hue (black) is not sufficiently uniform, coarse particles of the carbon black are formed, and a process for forming irregularities on the surface is performed. There is a possibility that the processability at the time may not be sufficiently excellent. The oil absorption is more preferably 250 ml / 100 g or less, and still more preferably 200 ml / 100 g or less. The oil absorption amount indicates the characteristics of the carbon black itself (of the powdered carbon black), and indicates the characteristics of the carbon black before being dispersed in the cured resin or the like. Further, the oil absorption amount increases when the carbon black is aggregated and decreases when the carbon black is dispersed. As the carbon black is more dispersed, the uniformity in the cured resin film is improved. Therefore, it is preferable that the oil absorption is smaller. Thus, the cured resin film preferably has a form in which black fine particles are dispersed. That is, the cured resin film of the present invention is preferably obtained using a curable resin composition in which black fine particles are dispersed and contained in a curable resin material (resin binder) as a raw material. Moreover, it does not specifically limit as a containing form of the black material in a cured resin film. For example, the black resin etc. which are mentioned later are contained in the cured resin film as particles (black material-containing particles) dispersed and contained in other components such as a resin. Moreover, it does not specifically limit as preferable resin which comprises black material containing particle | grains, The resin mentioned later is mentioned as a preferable cured resin which comprises a cured resin film. Furthermore, as a specific aspect, the black material-containing particles are preferably black material-containing particles containing a cured resin having the same or equivalent refractive index as that of the cured resin contained in the cured resin film.

The means (method) for dispersing or dissolving the black material (preferably black fine particles) in the resin binder (curable resin raw material) is not particularly limited, and various methods can be suitably used. For example, when the resin binder is soluble in a solvent, a method in which a black material is mixed and dispersed or dissolved in a resin binder solution in which a curable resin material is dissolved in a solvent, and the resin binder is dissolved in a dispersion in which the black material is dispersed. Various methods such as a method of mixing, dispersing and dissolving a black material in a dispersion in which a resin binder is dispersed in fine particles, a method of melting and kneading a mixture of a resin binder and black particles, and the like. And can be appropriately selected and used according to the cured resin. Among these, a method in which the curable resin raw material is solvent-soluble and a black material is mixed and dispersed or dissolved in a resin binder solution in which the curable resin raw material is dissolved in a solvent is preferable. When the curable resin material is solvent-soluble, it is easy to uniformly disperse or dissolve the black material in a mixture (for example, curable resin material solution) composed of the curable resin material and the solvent. A curable resin composition uniformly dispersed or dissolved is obtained, and as a result, an excellent light-shielding curable resin film in which the black material is uniformly distributed can be obtained. Thus, a cured resin film comprising a cured resin in which the curable resin raw material is solvent-soluble is also a preferred embodiment of the present invention.

The solvent is appropriately selected according to the type of resin, but ketones such as methyl ethyl ketone (2-butanone), methyl isobutyl ketone (4-methyl-2-pentanone), cyclohexanone, etc .; PGMEA (2-acetoxy-1- Methoxypropane), glycol derivatives such as ethylene glycol mono-n-butyl ether, ethylene glycol monoethyl ether, ethylene glycol ethyl ether acetate (ether compounds, ester compounds, ether ester compounds, etc.); amides such as N, N-dimethylacetamide Esters such as ethyl acetate, propyl acetate and butyl acetate; pyrrolidones such as N-methyl-2-pyrrolidone (more specifically, 1-methyl-2-pyrrolidone); aromatic carbonization such as toluene and xylene; Hydrogen; cyclohex Emissions, aliphatic hydrocarbons such as heptane; ethers such as diethyl ether and Djibouti ether and the like.
More preferably, the solvent is methyl ethyl ketone (2-butanone), methyl isobutyl ketone (4-methyl-2-pentanone), cyclohexanone, PGMEA (2-acetoxy-1-methoxypropane), N, N-dimethylacetamide, Examples include ethyl acetate and 1-methyl-2-pyrrolidone (NMP).
Further, the curable resin raw material is a precursor polymer such as polyamic acid which is a poly (amide) imide resin raw material, or an aromatic diamine compound and an aromatic tetracarboxylic dianhydride which are raw materials of the precursor polymer. , N-methyl-2-pyrrolidone, N, N′-dimethylacetamide, aromatic hydrocarbons, and mixtures thereof are more preferred. When the curable resin raw material is a polyfunctional epoxy compound that is a raw material of an epoxy resin, or a polyfunctional epoxy compound and a curing agent, ketones, aromatic hydrocarbons, glycol derivatives, or these More preferably, it is a mixture.

As the solvent-soluble curable resin raw material, among the curable resin raw materials described above, an epoxy compound and a poly (amide) imide resin precursor polymer which are various solvent-soluble epoxy resin raw materials are preferable.

The solvent-soluble epoxy compound is, for example, a polyfunctional epoxy compound that is cationically cured in the presence of a cationic curing catalyst, or a polyfunctional epoxy compound that is cured using a curing agent such as an acid anhydride or a polyvalent amine. Therefore, a cured product (epoxy resin cured product) can be obtained. In any case, as a preferred embodiment, a light-shielding resin composition obtained by dispersing or dissolving a black material in the precursor polymer of the poly (amide) imide resin or an epoxy compound solution (cationic curing catalyst or curing agent). A light-shielding film is obtained by applying, drying, and heating (poly (amide) imidization and curing).
As the usage-amount of the said solvent, 150 weight part or more is preferable with respect to 100 weight part of organic resin raw materials, and 1900 weight part or less is preferable. More preferably, it is 200 parts by weight or more and 1400 parts by weight or less.

Since the cured resin film manufactured by the manufacturing method of the said cured resin film consists of the structure mentioned above, it will be excellent in heat resistance. The heat resistance of the cured resin film can be evaluated by a change in film shape when the film is heated at a high temperature. As the change in film shape, the smaller the change in film dimensions (longitudinal and transverse lengths in the plane, the length in the thickness direction) before and after heating, the better the shape retention. Preferably there is. As a specific example of having excellent shape retainability (having heat resistance), when heated at 200 ° C. for 1 minute, the rate of change (dimensional change rate) of each length after heating with respect to before heating is 10% or less. It is to become. The size of the sample when measuring the dimensional change rate may be appropriately selected. In this experiment, a sample having a size of 50.0 mm in length, 10.0 mm in width, and 35 to 80 μm in thickness was used. When the dimensional change rate is 10% or less, the characteristics of the cured resin film can be sufficiently exhibited in the above-described use under the conditions normally used. For example, the generation and expansion of optical noise inside the lens unit can be achieved. Can be suppressed. The dimensional change rate is more preferably 5% or less, still more preferably 3% or less, and particularly preferably 1% or less.
The dimensional change rate may be measured under more severe conditions, and the heating temperature is preferably 250 ° C. The heating and holding time is preferably 2 minutes. More preferably, it is 5 minutes, More preferably, it is 10 minutes. A cured resin film having a dimensional change rate in the above range under such severe conditions is more preferable.
More preferably, the dimensional change rate is preferably 10% or less of the change rate (dimensional change rate) of each length after heating with respect to before heating when heated at 260 ° C. for 2 minutes. Measurement conditions are preferably performed in an air atmosphere. That is, when the cured resin film is heated at 260 ° C. for 2 minutes in an air atmosphere, the dimensional change rate of the length, width, and thickness after heating with respect to before heating is 10% or less. preferable. When the cured resin film is used for a lens unit, the dimensional change is small by heating at 260 ° C. for 2 minutes, so that it can sufficiently withstand the solder reflow process. Can do. In this case, the dimensional change rate is more preferably 5% or less, still more preferably 3% or less, and particularly preferably 1% or less.

Hereinafter, the curable resin composition used as the curable resin film of the present invention and the curable resin composition that is a raw material for forming the curable resin constituting the curable resin film (the curable resin raw material before curing and other curable resin materials). The composition containing the components) will be described in more detail. As described above, in the method for producing a cured resin film of the present invention, the cured resin included as an essential component is a curable resin cured product, and specifically, the above-described cured resin can be suitably used. As the curable resin for forming the curable resin cured product, a compound having at least one epoxy group, a polyhydric phenol compound, a compound having a polymerizable unsaturated bond, a poly (amide) imide resin, and the like are preferable. . These compounds are further described below.

When the curable resin contained in the curable resin film is a curable resin cured product such as an epoxy resin or a poly (amide) imide resin, a corresponding curable resin may be used as the curable resin material. it can.
A compound having at least one epoxy group that can be suitably used as a curable resin raw material used in the method for producing a cured resin film of the present invention will be described. The compound having at least one epoxy group is preferably a polyfunctional epoxy compound having two or more epoxy groups in the molecule.
As the compound having at least one epoxy group, the following compounds are suitable. Epibis type glycidyl ether type epoxy resin obtained by condensation reaction of bisphenols such as bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol and epihalohydrin, and these bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, etc. High molecular weight epibis type glycidyl ether type epoxy resin obtained by further addition reaction with other bisphenols; phenols such as phenol, cresol, xylenol, naphthol, resorcin, catechol, bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol And formaldehyde, acetoaldehyde, propionaldehyde, benzaldehyde, hydroxybenzaldehyde Obtained by condensation reaction of polyhydric phenols obtained by condensation reaction of hydride, salicylaldehyde, dicyclopentadiene, terpene, coumarin, paraxylylene glycol dimethyl ether, dichloroparaxylylene, bishydroxymethylbiphenyl, etc. with epihalohydrin. Novolak aralkyl type glycidyl ether type epoxy resin; aromatic crystalline epoxy resin obtained by condensation reaction of tetramethylbiphenol, tetramethylbisphenol F, hydroquinone, naphthalene diol and the like with epihalohydrin, and the above bisphenols and tetramethyl Aromatic crystalline epoxy tree obtained by addition reaction of biphenol, tetramethylbisphenol F, hydroquinone, naphthalene diol, etc. High molecular weight polymers of the above; alicyclic glycols hydrogenated aromatic skeletons such as bisphenols, tetramethylbiphenol, tetramethylbisphenol F, hydroquinone, naphthalene diol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, PEG600, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, PPG, glycerol, diglycerol, tetraglycerol, polyglycerol, trimethylolpropane and its multimer, pentaerythritol and its multimer, glucose, fructose, lactose Aliphatic glycidyl ether type epoxide obtained by condensation reaction of mono / polysaccharides such as maltose and epihalohydrin (3,4-epoxycyclohexane) epoxy resin having an epoxycyclohexane skeleton such as methyl 3 ′, 4′-epoxycyclohexyl carboxylate; condensation of tetrahydrophthalic acid, hexahydrophthalic acid, benzoic acid and epihalohydrin A glycidyl ester type epoxy resin obtained by reaction; a tertiary amine-containing glycidyl ether type epoxy resin solid at room temperature obtained by a condensation reaction of hindatoin, cyanuric acid, melamine, benzoguanamine and epihalohydrin. Among them, the aliphatic glycidyl ether type epoxy resin and the epoxy resin having an epoxycyclohexane skeleton are more preferably used for the purpose of suppressing the appearance deterioration during light irradiation.

The compound having at least one epoxy group is also preferably a compound having flexibility. By including a compound having flexibility, for example, handling properties are excellent in processes such as processing and molding. By using a compound having flexibility, it is particularly suitable, for example, when it is formed into a film shape or the like. As the compound having at least one flexible epoxy group, specifically, a compound having an oxyalkylene skeleton represented by — [— (CH ₂ ) _n —O—] _m — (n is 2 or more) , M is an integer greater than or equal to 1. Preferably, n is 2-12, m is an integer of 1-1000, More preferably, n is 3-6, m is an integer of 1-20.) Polymer epoxy resin (for example, hydrogenated bisphenol type epoxy resin (manufactured by Japan Epoxy Resin, YL-7170, epoxy equivalent 1000, solid hydrogenated epoxy resin); epoxy resin whose oxyalkylene skeleton is oxybutylene (Japan epoxy resin) YL-7217, epoxy equivalent 437, liquid epoxy resin (10 ° C. or higher), YED-216D manufactured by Japan Epoxy Resin); Resin (for example, YE-8100BX, YX6954BX, etc., manufactured by Japan Epoxy Resin Co., Ltd.); cycloaliphatic solid epoxy resin (EHPE-3150, manufactured by Daicel Kogyo Co., Ltd.); Among these, more preferred are compounds containing an epoxy group at the terminal, side chain, main chain skeleton, etc. Thus, a compound having at least one epoxy group has flexibility. This is one of the preferred embodiments of the present invention.

In the present invention, a curable resin containing a non-curable component such as a thermoplastic resin and a low molecular weight curable compound can also be used. Examples of the thermoplastic resin include polyethylene, polypropylene, polystyrene, acrylonitrile / styrene copolymer (AS resin), ABS resin made of acrylonitrile / butadiene / styrene, vinyl chloride resin, (meth) acrylic resin, polyamide resin, and acetal resin. , Polycarbonate resin, polyphenylene oxide, polyester, poly (amide) imide and the like. As the curable compound, a polyhydric phenol compound, a compound having a polymerizable unsaturated bond, a poly (amide) imide resin, and a compound having at least one epoxy group may be appropriately selected and used. That's fine.

When the curable resin raw material has at least one epoxy group as the curable resin composition of the present invention, the cured resin may be obtained by cation curing using a heat latent cation generator. preferable. That is, the curable resin raw material has at least one epoxy group, and the curable resin composition is a cation curable resin composition in which the thermal latent cation generator is essential. This is one of the preferred forms.

Examples of the heat latent cation generator include the following general formula (1):
_{^{(R 1 b R 2 c R}} 3 d R 4 e Z) + m (MXn) -m (1)
(In the formula, Z represents at least one element selected from the group consisting of S, Se, Te, P, As, Sb, Bi, O, N and halogen elements. R ¹ , R ² , R ³ and R ⁴ is the same or different and represents an organic group, b, c, d and e are 0 or a positive number, and the sum of b, c, d and e is equal to the valence of Z. Cation (R ^{1 _{.M b R 2 c R 3 d}} R 4 e Z) + m are representative of the onium salt, represents a metal or metalloid which is the central atom of a halide complex (metalloid), B, P, as, Al, Ca, It is at least one selected from the group consisting of In, Ti, Zn, Sc, V, Cr, Mn, and Co. X represents a halogen element, and m is the net charge of the halide complex ion. Is the number of halogen elements in the halide complex ion.) It is preferable that it is represented by these.

Specific examples of the anion (MXn) ^-m of the general formula (1) include tetrafluoroborate (BF ⁴⁻ ), hexafluorophosphate (PF ⁶⁻ ), hexafluoroantimonate (SbF ⁶⁻ ), hexafluoro arsenates ^{(AsF 6-),} hexachloroantimonate (SbCl ^6-), and the like.
Further general formula MXn (OH) ^- anions may be used which is represented by. Other anions include perchlorate ion (ClO ₄ ⁻ ), trifluoromethyl sulfite ion (CF ₃ SO ₃ ⁻ ), fluorosulfonate ion (FSO ₃ ⁻ ), toluenesulfonate ion, and trinitrobenzenesulfone. An acid ion etc. are mentioned.

Specific products of the above-mentioned heat-latent cation generator include diazonium salt types: AMERICURE series (American Can), ULTRASET series (Adeka), WPAG series (Wako Pure Chemical Industries), iodonium salt type : UVE series (manufactured by General Electric), FC series (manufactured by 3M), UV9310C (manufactured by GE Toshiba Silicone), Photoinitiator 2074 (manufactured by Rhone-Poulenc), WPI series (manufactured by Wako Pure Chemical Industries), sulfonium salt type : CYRACURE series (manufactured by Union Carbide), UVI series (manufactured by General Electric), FC series (manufactured by 3M), CD series (manufactured by Satomer), optomer SP series, optomer CP series (ADEKA) Etsu Chemical Co., Ltd.), San-Aid SI series (Sanshin Chemical Industry Co., Ltd.), CI series (manufactured by Nippon Soda Co., Ltd.), WPAG series (manufactured by Wako Pure Chemical Industries, Ltd.), CPI series (manufactured by San-Apro Ltd.), and the like. These are all trade names.

Examples of the curing agent other than the thermal latent cation generator include acid anhydrides such as methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, pyromellitic anhydride, and methylnadic acid; Various phenol resins such as phenol novolak resin, cresol novolak resin, bisphenol A novolak resin, dicyclopentadiene phenol resin, phenol aralkyl resin, terpene phenol resin; various phenols and various such as hydroxybenzaldehyde, crotonaldehyde, glyoxal Various phenol resins such as a polyhydric phenol resin obtained by a condensation reaction with aldehydes; one or more of BF ₃ complexes, sulfonium salts, imidazoles and the like can be used.

In the curing of the curable resin composition containing the compound having at least one epoxy group, a curing accelerator can be used. For example, triphenylphosphine, tributylhexadecylphosphonium bromide, tributylphosphine, tris ( One or more organic phosphorus compounds such as dimethoxyphenyl) phosphine are suitable.
As said hardening temperature, 70-200 degreeC is preferable. More preferably, it is 80-150 degreeC. The curing time is preferably 30 seconds to 1 hour. More preferably, it is 1 to 3 minutes.

Examples of the cured resin suitably used in the method for producing a cured resin film of the present invention include poly (amide) imide resins, and specifically include thermosetting poly (amide) imide resin cured products. As long as these have an imide ring, the compound as a raw material is not limited, but when used for the cured resin film of the present invention, from the viewpoint of production productivity, cost, heat resistance, A thermosetting poly (amide) imide resin is preferable, and an aromatic thermosetting poly (amide) imide resin is more preferable.
The poly (amide) imide resin means a polyimide resin in a narrow sense (resin including an imide bond and not including an amide bond) and a polyamideimide resin (resin including an amide bond and an imide bond). There are two types of such poly (amide) imide resins, thermosetting resins and thermoplastic resins. In the present invention, thermosetting poly (amide) imide resins are preferred, and more preferably aromatic It is a group thermosetting poly (amide) imide resin.
The poly (amide) imide resin is a raw material of a poly (amide) imide resin obtained by a reaction between a polyvalent carboxylic acid compound and a polyvalent amine compound and / or a polyvalent isocyanate compound (hereinafter also referred to as a precursor polymer). Can be obtained by imidization reaction, but the form in which the curable resin composition contains such a precursor polymer is one of the preferred forms of the present invention. More preferably, the precursor polymer has an aromatic ring.

In the precursor polymer, the polyvalent carboxylic acid compound is a compound having two or more carboxyl groups or carboxyl group-derived groups in the molecule, and includes anhydrides thereof. The carboxyl group-derived group is a group represented by COX, and X is a halogen element or a group represented by OR ⁴ (R ⁴ represents an alkyl group having 1 to 6 carbon atoms or a phenyl group).
As the polyvalent carboxylic acid compound, a tetracarboxylic acid compound (including its anhydride) and a tricarboxylic acid compound (including its anhydride) are suitable. These may be reacted with alcohols such as methanol and ethanol to form ester compounds.

As the tetracarboxylic acid compound, the following aromatic tetracarboxylic dianhydrides are suitable.
Pyromellitic dianhydride (PMDA), 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7- Naphthalenetetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 2,3,3 ′, 4′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4 , 4'-biphenyltetracarboxylic dianhydride (BPDA), 2,2 ', 3,3'-benzophenone tetracarboxylic dianhydride, 2,3,3', 4'-benzophenone tetracarboxylic dianhydride 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA), bis (3,4-dicarboxyphenyl) sulfone dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride Thing, screw 3,4-dicarboxyphenyl) methane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride 2,2-bis [3,4- (dicarboxyphenoxy) phenyl] propane dianhydride (BPADA), 4,4 ′-(hexafluoroisopropylidene) diphthalic anhydride, oxydiphthalic anhydride (ODPA), Bis (3,4-dicarboxyphenyl) sulfone dianhydride, bis (3,4-dicarboxyphenyl) sulfoxide dianhydride, thiodiphthalic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, 9,9-bis ( 3,4-dicarboxyphenyl) fluorene dianhydride and 9,9-bis [4- (3,4'-dicarboxyphenoxy) phenyl] fluorene dianhydride.

Among these, pyromellitic dianhydride (PMDA), 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA), 3,3 ′, 4,4′-benzophenone tetracarboxylic acid Anhydride (BTDA), 2,2-bis [3,4- (dicarboxyphenoxy) phenyl] propane dianhydride (BPADA), oxydiphthalic anhydride (ODPA), 2,3,3 ′, 4-biphenyltetra Carboxylic dianhydride, 2,2'-bis (3,4-dicarboxyphenyl) propane dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride, bis (3,4-di Carboxyphenyl) ether dianhydride, ethylenetetracarboxylic dianhydride and the like are preferred.

As the tricarboxylic acid compound (including tricarboxylic acid monoanhydride), those containing an aliphatic cyclic hydrocarbon, an aromatic ring or an aromatic heterocyclic ring are suitable. For example, a phenyl group, a biphenyl group, a terphenyl group, Three carboxyl groups or derivatives thereof are bonded to groups such as naphthalene group, perylene group, diphenyl ether group, diphenylsulfone group, diphenylpropane group, benzophenone group, biphenyltrifluoropropane group, cyclobutyl group, cyclopentyl group, cyclohexyl group, etc. And the like. Among these, those containing an aromatic ring are preferable, and trimellitic acid, hydrogenated trimellitic acid, and anhydrides and derivatives thereof are more preferable.

The polyvalent amine compound is a compound having two or more amino groups in the molecule, and particularly preferably a compound having two amino groups in the molecule (diamine compound). As the diamine compound, an aromatic diamine containing an aromatic ring between two amino groups, an aliphatic diamine composed of an aliphatic group between two amino groups, and a structural unit containing a siloxane bond between two amino groups Siloxane diamine etc. which have can be used.

Specific examples of the aromatic diamine include paraphenylenediamine (PPD), metaphenylenediamine (MPDA), 2,5-diaminotoluene, 2,6-diaminotoluene, 4,4′-diaminobiphenyl, 3, 3'-dimethyl-4,4'-biphenyl, 3,3'-dimethoxy-4,4'-biphenyl, 2,2-bis (trifluoromethyl) -4,4'-diaminobiphenyl, 4,4'- Bis (3-aminophenoxy) biphenyl, 3,3′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane (MDA), 2,2-bis- (4-aminophenyl) propane, 3,3′-diaminodiphenylsulfone (33DDS), 4,4'-diaminodiphenylsulfone (44DDS), 3,3'-diaminodiphenyl sulfide, 4,4 ' Diaminodiphenyl sulfide, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether (34 ODA), 4,4′-diaminodiphenyl ether (ODA), 1,5-diaminonaphthalene, 4,4′-diaminodiphenyldiethylsilane 4,4′-diaminodiphenylsilane, 4,4′-diaminodiphenylethylphosphine oxide,

1,3-bis (3-aminophenoxy) benzene (133APB), 1,3-bis (4-aminophenoxy) benzene (134APB), 1,4-bis (4-aminophenoxy) benzene, bis [4- ( 3-aminophenoxy) phenyl] sulfone (BAPSM), bis [4- (4-aminophenoxy) phenyl] sulfone (BAPS), 2,2-bis [4- (4-aminophenoxy) phenyl] propane (BAPP), 2,2-bis (3-aminophenyl) 1,1,1,3,3,3-hexafluoropropane, 2,2-bis (4-aminophenyl) 1,1,1,3,3,3- Hexafluoropropane and 9,9-bis (4-aminophenyl) fluorene, 3,3'-dichlorobenzidine, 1,5-diaminonaphthalene, 3,3'-dimethyl- 4,4'-biphenyldiamine, benzidine, 3,3'-dimethylbenzidine, 3,3'-dimethoxybenzidine, 4,4'-diaminodiphenylpropane, 2,4-bis (β-amino-t-butyl) toluene Bis (p-β-amino-t-butylphenyl) ether, bis (p-β-methyl-δ-aminophenyl) benzene, bis-p- (1,1-dimethyl-5-amino-pentyl) benzene, Examples include 1-isopropyl-2,4-m-phenylenediamine, m-xylylenediamine, and p-xylylenediamine.

Among these, paraphenylenediamine (PPD), metaphenylenediamine (MPDA), 4,4′-diaminodiphenylmethane (MDA), 3,3′-diaminodiphenylsulfone (33DDS), 4,4′-diaminodiphenylsulfone ( 44DDS), 3,4'-diaminodiphenyl ether (34ODA), 4,4'-diaminodiphenyl ether (ODA), 1,3-bis (3-aminophenoxy) benzene (133APB), 1,3-bis (4-amino) Phenoxy) benzene (134APB), bis [4- (3-aminophenoxy) phenyl] sulfone (BAPSM), bis [4- (4-aminophenoxy) phenyl] sulfone (BAPS), 2,2-bis [4- ( 4-aminophenoxy) phenyl] propane (BAPP) and the like Is preferred.

Examples of the aliphatic diamine include di (p-aminocyclohexyl) methane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, diaminopropyltetramethylene, and 3-methylheptamethylenediamine. 4,4-dimethylheptamethylenediamine, 2,11-diaminododecane, 1,2-bis-3-aminopropoxyethane, 2,2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine, 2,5-dimethylhepta Methylenediamine, 5-methylnonamethylenediamine, 2,17-diaminoeicosadecane, 1,4-diaminocyclohexane, 1,10-diamino-1,10-dimethyldecane, 1,12-diaminooctadecane, piperazine, _{2 N (CH 2) 3 O} (CH 2) 2 OCH 2 NH 2, H 2 N (CH 2) 3 S (CH 2) 3 NH 2, H 2 N (CH 2) 3 N (CH 2) 2 ( CH ₂ ) ₃ NH _{2 and the} like.

Examples of the siloxane diamine include polydimethylsiloxane diamine (silicone oil X-22-161AS (amine equivalent 450), X-22-161A (amine equivalent 840), X-22-161B (amine equivalent 1500), X- 22-9409 (amine equivalent 700), X-22-1660B-3 (amine equivalent 2200), KF-8010 (amine equivalent 415) (above, manufactured by Shin-Etsu Chemical Co., Ltd.)) and the like.

The polyvalent isocyanate compound is a compound having two or more isocyanate groups in the molecule, and particularly preferably a compound (diisocyanate compound) having two isocyanate groups in the molecule.
Examples of the diisocyanate compound include methylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, isophorone diisocyanate, cyclohexyl diisocyanate, p-xylene diisocyanate, m-xylene diisocyanate, 4,4′-bis ( 3-Tolylene) diisocyanate, 3,3′-dichloro-4,4′-diisocyanate biphenyl, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyl ether diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate and the like. .

In the reaction of the polyvalent carboxylic acid compound with the polyvalent amine compound and / or the polyvalent isocyanate compound, the ratio of these components may be appropriately set by adjusting the molecular weight recommended for the precursor polymer or the like. For example, when the total amount of the carboxyl group and the derivative group thereof is 1 mol, it is preferable that the total molar amount of the amino group and the isocyanate group is 0.7 to 1.5 mol. When the amount is more than 1.5 mol, unreacted polyvalent amine compound or polyvalent isocyanate compound tends to remain, and there is a possibility that the film forming property may not be sufficient. When the amount is less than 0.7 mol, gelation occurs. In this case, the film forming property may not be sufficient. More preferably, the total molar amount of amino group and isocyanate group is 0.9 to 1.3 mol.

The above reaction may be carried out by a usual method. For example, the reaction temperature is preferably 80 to 210 ° C. This makes it possible to shorten the reaction time and sufficiently suppress gelation. More preferably, it is 100-190 degreeC, More preferably, it is 120-180 degreeC. The reaction time is preferably 30 minutes to 15 hours, more preferably 1 to 10 hours.

The above reaction may also be performed in the presence of an organic solvent or a catalyst as necessary.
The organic solvent is preferably an organic polar solvent, for example, N, N-dimethylformamide, N, N-dimethylacetamide, N, N-diethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2 -Imidazolidinone, N-methylcaprolactam, hexamethylphosphoric triamide, 1,2-dimethoxyethane, diglyme and triglyme. Among these, N, N-dimethylacetamide (DMAc) and N-methyl-2-pyrrolidone (NMP) are preferable. These solvents can be used alone or as a mixture, or can be used by mixing with other solvents such as aromatic hydrocarbons such as toluene and xylene.
Examples of the catalyst include tertiary amines, alkali metals, alkaline earth metals, metals such as tin, zinc, titanium, and cobalt, or metalloid compounds.

As said precursor polymer (raw material of poly (amide) imide resin), following formula (2);

(In the formula, R ⁵ is the same or different and represents a trivalent or tetravalent organic group having at least 2 or more carbon atoms. R ⁶ is the same or different and contains at least 2 or more carbon atoms. X is the same or different and represents a halogen element or a group represented by OR ^7. R ⁷ is the same or different and is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Or a phenyl group, wherein r is a number from 1 to 2, and n is the number of repeating units, and is an integer from 1 to 1000). Is preferred.

In the above formula (2), R ⁵ preferably contains an aliphatic cyclic hydrocarbon, an aromatic ring or an aromatic heterocyclic ring from the viewpoint of heat resistance. More preferably, R ⁵ is an aliphatic cyclic hydrocarbon, an aromatic ring or an aromatic heterocyclic ring, and is a trivalent or tetravalent group having 4 to 30 carbon atoms. Specifically, for example, phenyl group, biphenyl group, terphenyl group, naphthalene group, perylene group, diphenyl ether group, diphenylsulfone group, diphenylpropane group, benzophenone group, biphenyltrifluoropropane group, cyclobutyl group, cyclopentyl group, cyclohexane Although a hexyl group etc. are mentioned, it does not specifically limit and various organic groups can be used.

R ⁶ preferably contains an aliphatic cyclic hydrocarbon, an aromatic ring or an aromatic heterocyclic ring from the viewpoint of heat resistance. More preferably, R ⁶ is an aliphatic cyclic hydrocarbon, an aromatic ring or an aromatic heterocyclic ring and is a divalent group having 6 to 30 carbon atoms. Specifically, for example, phenyl group, biphenyl group, terphenyl group, naphthalene group, perylene group, diphenyl ether group, diphenylsulfone group, diphenylpropane group, benzophenone group, biphenyltrifluoropropane group, diphenylmethane group, dicyclohexylmethane group, etc. However, it is not particularly limited, and various organic groups can be used.

Further, the COX group represents a carboxyl group or a derivative group thereof. X is the same or different and represents a halogen element or a group represented by OR ⁷ , and R ⁷ is the same or different and represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group. As a halogen element, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are preferable.

In the general formula (2), n represents the number of repeating structural units represented by the general formula (2) in the precursor polymer, and is an integer of 1 to 1000. Preferably, it is 2 or more, and if the viscosity becomes too high, the compatibility with the black material may not be sufficient, so that it is preferably 500 or less.

In the precursor polymer containing the structural unit (2), the content of the structural unit (2) is preferably 30 to 100% by mass with respect to 100% by mass of the polymer. More preferably, it is 50-100 mass%.

In the above general formula (2), as a precursor polymer mainly composed of the structural unit (2) where r = 2, for example, a polyamic acid (polyimide precursor) synthesized from tetracarboxylic dianhydride and diamine Polymer). Moreover, as a precursor polymer which has the structural unit (2) which is r = 1 as a main component, for example, a polyvalent carboxylic acid compound containing a tricarboxylic acid compound, a polyvalent amine compound and / or a polyvalent isocyanate compound A polyamideimide precursor polymer obtained by the reaction is preferable.

The compound having a polymerizable unsaturated bond, which is one of the preferred forms of the curable resin raw material of the present invention, will be described in detail.
The compound having a polymerizable unsaturated bond may be any compound having a polymerizable unsaturated bond, but one or more selected from the group consisting of a (meth) acryloyl group, a vinyl group, a fumarate group, and a maleimide group. It is preferable that it is a compound which has these groups. That is, it is preferably at least one compound selected from the group consisting of a compound having a (meth) acryloyl group, a compound having a vinyl group, a compound having a fumarate group, and a compound having a maleimide group. In the present invention, the (meth) acryloyl group means an acryloyl group and a methacryloyl group, and when it has an acryloyl group, it has a vinyl group in the acryloyl group. Does not have an acryloyl group and a vinyl group, but has an acryloyl group. The fumarate group means a group having a fumarate structure, that is, a group having a fumarate ester structure.

When the curable resin raw material of this invention contains a polyhydric phenol compound, it can be set as hardened | cured material by thermosetting using a hardening | curing agent. Examples of the curing agent include a compound having at least two epoxy groups. As the compound having at least two epoxy groups, an epoxy resin having an average of two or more epoxy groups in one molecule is preferable. Epibis type glycidyl ether type epoxy resin obtained by condensation reaction of bisphenols such as bisphenol A, bisphenol F, bisphenol S and epihalohydrin; such as phenol, cresol, xylenol, resorcin, catechol, bisphenol A, bisphenol F, etc. Phenols and formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, salicylaldehyde, dicyclopentadiene, terpene, coumarin, paraxylylene dimethyl ether, dichloroparaxyl A novolak-aralkyl-type glycidyl ether-type epoxy resin obtained by further condensing a polyhydric phenol obtained by the condensation reaction of benzene with an epihalohydrin; tetrahydrophthalic acid, hexahydrophthalic acid, benzoic acid and an epihalohydrin Glycidyl ester type epoxy resin obtained by condensation reaction; Glycidyl ether type epoxy resin obtained by condensation reaction of hydrogenated bisphenol or glycol and epihalohydrin; Amine-containing glycidyl ether type obtained by condensation reaction of hindatoin or cyanuric acid and epihalohydrin Epoxy resins; aromatic polycyclic epoxy resins such as biphenyl type epoxy resins and naphthalene type epoxy resins are suitable. Moreover, the compound which has an epoxy group in a molecule | numerator by addition reaction with these epoxy resins, polybasic acids, and / or bisphenols may be sufficient. These can use 1 type (s) or 2 or more types.

The blending mass ratio of the polyhydric phenol compound and the epoxy resin curing agent (polyhydric phenol compound / epoxy resin curing agent) is preferably 30/70 or more, and 70/30 or less. It is preferable that If it is less than 30/70, the mechanical properties and the like of the cured product formed may be reduced, and if it exceeds 70/30, the flame retardancy may be insufficient. More preferably, it is 35/65 or more and 65/35 or less. A curing accelerator may be used for the curing. Examples of the curing accelerator include imidazoles such as 2-methylimidazole and 2-ethyl-4-methylimidazole; 2,4,6-tris (dimethylaminomethyl). ) Amines such as phenol, benzylmethylamine, DBU (1,8-diazabicyclo [5.4.0] -7-undecene), DCMU (3- (3,4-dichlorophenyl) -1,1-dimethylurea) An organic phosphorus compound such as tributylphosphine, triphenylphosphine, and tris (dimethoxyphenyl) phosphine is preferable.

The curable resin composition of the present invention preferably contains a surface conditioner in addition to the curable resin raw material described above. The surface conditioning agent can be suitably used for improving the uniformity of the light-shielding layer film, specifically, for eliminating holes or eliminating skin. As the surface conditioner, a compound having a high surface tension reducing ability is preferable because it has a high effect of eliminating holes. Further, a compound having a high polarity is preferable in terms of a high effect of eliminating the yuzu skin. As the surface conditioner, for example, a silicon-based surface conditioner (silicon-based additive) is preferable. As the silicon-based surface conditioning agent, BYK-300, BYK-301, BYK-302, BYK-306, BYK-307, BYK-310, BYK-315, BYK-320, BYK-322, manufactured by BYK Japan BYK-323, BYK-325, BYK-330, BYK-331, BYK-333, BYK-337, BYK-341, BYK-344, BYK-345, BYK-346, BYK-347, BYK-348, BYK- 349, BYK-370, BYK-375, BYK-377, BYK-378, BYK-UV3500, BYK-UV3510, BYK-UV3570, and the like. Among these, from the viewpoint of high polarity, BYK-306, BYK-310, BYK-333, BYK-370, BYK-375 and the like are preferable. From the viewpoint of high surface tension reducing ability, BYK-306, BYK-307, BYK-330, BYK-333, BYK-370, BYK-377, BYK-341, BYK-375 and the like are preferable. Moreover, BYK-306, BYK-333, and BYK-375 are particularly preferable because of their high polarity and high surface tension reducing ability. These are all trade names.

The curable resin composition of the present invention includes a curing accelerator, a reactive diluent, a saturated compound having no unsaturated bond, a pigment, and a dye in addition to the above-described curable resin raw material, black material, surface conditioner, and the like. , Antioxidants, UV absorbers, light stabilizers, plasticizers, non-reactive compounds, chain transfer agents, thermal polymerization initiators, anaerobic polymerization initiators, polymerization inhibitors, inorganic and organic fillers, coupling agents Adhesion improver, heat stabilizer, antibacterial / antifungal agent, flame retardant, matting agent, antifoaming agent, leveling agent, wetting / dispersing agent, anti-settling agent, thickener / anti-sagging agent, color separation An inhibitor, an emulsifier, an anti-slip / scratch agent, an anti-skinning agent, a drying agent, an antifouling agent, an antistatic agent, a conductive agent (electrostatic aid), and the like may be contained.

Since the cured resin film produced by the method for producing a cured resin film of the present invention has the above-described configuration, it suppresses regular reflection of light, has excellent light scattering properties, and has a low glossiness. It can use suitably for a conductive film. Such a light-scattering film including the cured resin film is also one aspect of the present invention. When the light scattering film contains, for example, a) a white pigment such as barium sulfate or titanium oxide, b) a carbon-based black fine particle such as carbon black or graphite; Inorganic black fine particles such as metal oxide black fine particles such as titanium black; Black fine organic particles such as aniline black (organic black fine particles); Black fine particles such as anthraquinone, indigoid and diazo black organic dyes When a black material is contained, it is useful as a light-shielding film, and c) when transparent or semi-transparent, it is useful as a light-diffusing film having both diffusibility of transmitted light and scattering of reflected light.
Moreover, the light-shielding film can have a transmittance of less than 1% for light having a wavelength of 550 nm by using the light-scattering film of the present invention. Thus, the light-shielding film which consists of the said light-scattering film, Comprising: As for this light-shielding film, the light-shielding film whose transmittance | permeability with respect to the light of wavelength 550nm is less than 1% is also one of this invention.
The said transmittance | permeability is a value obtained by measuring the transmittance | permeability in 380-780 nm using the ultraviolet visible spectrophotometer needle | hook (Shimadzu UV-3100 (made by Shimadzu Corporation)). Although the form of the said light-shielding film is demonstrated below, the same form can be taken also about the light-scattering film mentioned above.

Although it will not specifically limit if the said light-shielding film is provided with the cured resin film of this invention, The other component may be contained as needed. In the case where the cured resin film is a thin film that does not have sufficient strength, it is preferable to include a base material in order to obtain sufficient strength. Thus, as a light-shielding film, (1) the form which is a laminated film consisting of a base material and a cured resin film (single side), (2) the form which is a laminated film consisting of a base material and a cured resin film (both sides), (3) The form which is a cured resin film single layer is suitable. The schematic diagram of these forms is shown in FIG. 6A shows the form of (1), (b) shows the form of (2), and (c-1) and (c-2) show the form of (3). In addition, you may set suitably the layer which has another function in the said light-shielding film.
In the forms of (1) and (2), since the strength of the light-shielding film can be obtained by the substrate, the cured resin film can be thinned. By thinning the cured resin film, it is easy to control the film thickness when the curable resin composition is applied, and when drying, the solvent contained in the composition can be removed by evaporation in a short time. It has an advantage that a cured resin film in which the generation of defects in the film that causes a decrease in light shielding performance such as generation of bubbles accompanying evaporation is suppressed can be easily obtained.
In the form of the laminated film comprising the base material and the cured resin film of (1) and (2), the thickness of the cured resin film is preferably 5 μm or more. More preferably, it is 10 μm or more. Moreover, as an upper limit of the thickness of a cured resin film, it is preferable that it is 80 micrometers or less, More preferably, it is 50 micrometers or less, More preferably, it is 30 micrometers or less. Moreover, as a particularly preferable range, it is 10-30 micrometers.
In the form in which the light-shielding film of (3) is composed of a single layer of cured resin film, the thickness of the cured resin film depends on the cured resin of the cured resin film, but it is easy to perform post-processing of the film and has excellent mechanical strength. From the viewpoint, it is preferably 20 μm or more, and more preferably 30 μm or more. Although the upper limit of the thickness of the cured resin film depends on the material of the cured resin film, it is preferably 200 μm or less, more preferably 200 μm or less in view of sufficient light shielding performance and application to a lens unit that is highly demanded of thinning. 100 μm or less. A particularly preferable range is 30 to 80 μm.
The said light-shielding film may be a form which has layers other than a cured resin film and a base material further. Although the thickness of a light-shielding film changes also with the form of a light-shielding film, and the application to apply, it is preferable that it is 1-1000 micrometers. More preferably, it is 10-200 micrometers as thickness of the said light-shielding film, More preferably, it is 20-100 micrometers. Here, the thickness of the light-shielding film is a thickness obtained by measuring the light-shielding film with a micrometer. By setting the thickness of the light-shielding film to 1 to 1000 μm, for example, when the light-shielding film is used as an optical member, the optical path can be shortened. Thereby, this optical member (for example, camera module etc.) can be reduced in thickness.

When the said light-shielding film has layers other than a cured resin film and a base material, the surface shape comprised by the several uneven | corrugated shape of this invention is the surface in which the said layer (layers other than a cured resin film) is formed. Is preferably formed on the opposite surface of the cured resin film. More preferably, both surfaces of the light-shielding film have the surface shape.

In the above light-shielding film, the arrangement of the cured resin film and the substrate in the case of having a substrate is not particularly limited, and any of the incident light surfaces is not particularly limited because it exerts the effects of the present invention. For prevention, a mode in which the cured resin film is disposed on the incident light surface is preferable.
The shape of the light-shielding film can be appropriately selected according to the application. When the lens is attached to a lens unit, it can be effectively transmitted through the light other than the optical path by attaching it to a bag for fixing the lens. Reflection can be suppressed, and optical noise can be reduced. That is, in the lens unit, as schematically shown in FIG. 7, it is preferable that a light-shielding film (in particular, a cured resin film) is attached to a bag for fixing the lens. That is, the positional relationship between the lens and the cured resin film in the lens unit is preferably that schematically shown in FIG. 8 when viewed as a cross-sectional view of the lens unit. Therefore, it is preferable that the cured resin film of the light-shielding film has a planar shape (ring shape) as schematically illustrated in FIG. 9 when viewed from the lens unit incident light side. The center of the ring may be a cavity, a transparent film that transmits visible light, or a lens. Preferably, the center of the ring is a cavity.

The light-shielding film preferably has a single layer structure. That is, the form comprised only with a cured resin film is suitable. By adopting such a form, the thickness of the light-shielding film can be reduced, and when used for optical applications (lens units), the optical path can be shortened, and the lens unit can be reduced in size and thickness. it can. A schematic diagram of a light-shielding film having a single-layer structure is shown in FIG. FIG. 6C-1 shows a form in which the unevenness is formed on one side, and FIG. 6C-2 shows a form in which the unevenness is formed on both sides.

In the case where the light-shielding film has a substrate (FIGS. 6A and 6B), the light-shielding film can have sufficient strength. As a material which comprises the said base material, any of an organic material, an inorganic material, an organic-inorganic composite material, and a metal material may be sufficient, and these may use 1 type, or 2 or more types. The above organic materials (for example, thermoplastic resin compositions and curable resin compositions) are easy to handle, the inorganic materials (for example, glass) are excellent in thermal expansion coefficient, and the organic / inorganic composite material has the characteristics of both. It is suitable from the point of providing. Any of these materials can be suitably used, but a material having reflow resistance is preferable.

The material of the substrate constituting the light-shielding film is preferably a material having reflow resistance. Specifically, (1) a fluorinated aromatic polymer, (2) a polycyclic aromatic polymer, ( It is preferable to include at least one selected from the group consisting of 3) poly (amide) imide resin, (4) fluorine-containing polymer compound, (5) glass film, and (6) polyetherketone resin. Thus, the light-shielding film is at least one selected from the group consisting of a fluorinated aromatic polymer, a polycyclic aromatic polymer, a poly (amide) imide resin, a fluorine-containing polymer compound, a glass film, and a polyether ketone resin. A light-shielding film comprising one material is also a preferred embodiment of the present invention.

As the substrate, any of the materials described above can be suitably used. As the material for the substrate, two or more kinds may be mixed or laminated. Among them, when two or more kinds are laminated to form a substrate having a multilayer structure, a plurality of characteristics of the material to be used are exhibited, and the substrate can be suitably used. For example, in applications such as camera modules where the light-shielding film needs to be thinned to less than 100 μm, there is a problem that when an inorganic material such as glass is thinned (for example, 30 μm to 100 μm), the organic material and / or Alternatively, by laminating with the organic / inorganic composite material, when the light shielding layer is further laminated on the base material, the base material is not deformed or cracked, and the base material is suitable as an optical member. More preferred is a form in which an organic resin is formed on one or both sides of a glass thin film, and particularly preferred is a form in which an organic resin is formed on both sides. Further, from the viewpoint of preventing cracking, an organic substance may be laminated after the light shielding layer is formed.

The thickness of the substrate can be appropriately selected according to the thickness of the light-shielding film. For example, when glass is used as the substrate, the thickness of the glass is preferably 30 to 500 μm, more preferably The thickness exceeds 100 μm. In the case of using a resin, for example, poly (amide) imide, kapton and the like can preferably use a sheet having a thickness of about 100 μm, but a film having a thickness of less than 100 μm is preferable.

As the heat-resistant temperature of the cured resin film constituting the light-shielding film, the 10% decomposition temperature is preferably 200 ° C. or higher, more preferably 250 ° C. or higher, further preferably 300 ° C. or higher, and most preferably 350 ° C. or higher. . Tg is preferably 80 ° C. or higher, more preferably 150 ° C. or higher, further preferably 200 ° C. or higher, and most preferably 250 ° C. or higher. By using such a cured resin film having reflow resistance, it can be suitably applied to automatic mounting of a light-shielding film.

In this specification, “having heat resistance” means having high resistance to heat. For example, in materials such as organic resins, Tg is high and decomposition temperature is high (preferably 10% decomposition). It is preferable to satisfy at least one of (high temperature), and excellent in shape retention in a base material, a light scattering film (particularly a light shielding film), and a use (for example, a lens unit) using the film. It is preferable to satisfy at least one of low dimensional change rate and high decomposition temperature (preferably high 10% decomposition temperature). “Having reflow resistance” means that it has sufficient resistance to the temperature used in the reflow process, and as in the case of having heat resistance, for example, in materials such as organic resins, Tg is It is preferable to satisfy at least one of high, high decomposition temperature (preferably high 10% decomposition temperature), base material, light-scattering film (especially light-shielding film), use using the film ( For example, in the lens unit, it is preferable to satisfy at least one of excellent shape retention and high decomposition temperature (preferably high 10% decomposition temperature). As preferable requirements for Tg, decomposition temperature, shape retention, and the like, it is preferable to satisfy the preferable requirements for the above-described characteristics.

The present invention is also a lens unit including the light-shielding film and a lens, and the lens unit is a lens unit that is a lens unit for an image sensor. The lens unit of the present invention is useful for optical applications and optical device applications, and can also be used as display device applications, mechanical components, electrical / electronic components, and the like.
In the lens unit, the light-shielding film is a film having a light-shielding layer that suppresses generation and expansion of optical noise inside the lens unit and removes the generated optical noise in the camera module. As the light-shielding film in the lens unit, the above-described light-shielding film is preferable. That is, it is preferable that the resin contained as an essential component in the light-shielding film is as described above. When the resin is as described above, the light-shielding film has reflow resistance and is suitably used for a lens unit having reflow resistance. Other suitable examples and preferred forms of the light-shielding film are as described above. In addition, although the said lens unit will be equipped with a light-shielding film and a lens, these numbers should just be equipped with one or more respectively, and the number with which it mounts according to the use etc. of a lens unit. Can be set as appropriate, and a plurality of may be provided. In the present specification, the “lens unit having reflow resistance” is a lens unit that is excellent in at least the shape retention of the light-shielding film. As a preferred form, as with the shape-retaining property of the light-shielding film described above, when heated at 200 ° C. for 1 minute, the change rate of each length (dimensional change rate) is 10% or less, more preferably 260 ° C. When heated for 2 minutes, the change rate of each length (dimensional change rate) is 10% or less. Under any condition, the dimensional change rate is more preferably 5% or less, still more preferably 3% or less, and particularly preferably 1% or less.

In the lens unit, the lens may be any material that can transmit and transmit a wavelength in the visible light region, and may be any one of an organic material, an inorganic material, and an organic / inorganic composite material. Two or more kinds may be used. The organic material (for example, thermoplastic resin composition, curable resin composition) is excellent in processability, and the inorganic material (for example, glass) is excellent in transparency / thermal expansion coefficient, for example, an organic / inorganic composite material (for example, The organic-inorganic composite resin composition) having both characteristics is suitable. A lens made of any material can be suitably used, but a material having reflow resistance (heat resistant material) is preferable.
Thus, the form which the light-shielding film and lens which comprise a lens unit have reflow resistance is one of the preferable forms of this invention. Since both the light-shielding film and the lens have sufficient heat resistance, automatic mounting becomes possible, the mounting cost is sufficiently reduced, and it can be suitably used for optical applications such as a camera module. As described above, the light-shielding film of the present invention is suitable for an imaging lens unit used for a camera module, and particularly suitable for an imaging lens unit used for a camera module subjected to a solder reflow process. That is, the lens unit is preferably an imaging lens unit used for a camera module, and particularly preferably an imaging lens unit used for a camera module used in a solder reflow process.

As a preferred specific example of an organic material as the material of the lens, a curable resin composition having a resin (raw material) mainly comprising a compound having at least one epoxy group is cured from the viewpoint of excellent colorless transparency and heat resistance. Cured resin cured product such as a material obtained by curing a curable resin composition containing a compound having a polymerizable unsaturated bond as a main resin (raw material); a phenol resin as a main resin (raw material) Tg of a material obtained by curing a curable resin composition, a material obtained by curing using a silicone resin as a main resin (raw material), a thermoplastic resin comprising a silicone resin, a polycycloolefin resin, a polycarbonate resin, etc. is 150 ° C. The above thermoplastic resin. Curing means conventionally known curing such as curing with heat or curing with active energy rays, and the curable resin composition further includes the above main compound, a curing catalyst for accelerating curing, and curing. A conventionally known material such as an accelerator or a curing agent is used in combination. In the above, “main” means 70% by mass or more based on the total amount of resin (raw material).
Particularly preferred as the material is a material obtained by curing a curable resin composition containing an epoxy group-containing compound as a main resin (raw material). About the epoxy group containing compound and the compound which has a polymerizable unsaturated bond, the aspect regarding the same kind compound in the curable resin composition for cured resin films can be applied.
The organic material component of the organic / inorganic composite material is preferably the preferred organic material.

The lens is preferably obtained by curing a curable resin composition. By using a curable resin composition, it is possible to perform complicated processing that cannot be performed with an inorganic material (for example, glass) at low cost, and a lens having heat resistance that cannot be achieved when a thermoplastic resin composition is used. In the processing (molding) and mounting on the lens unit, there is an advantage that it is suitable for an industrial production process and can be performed efficiently. The lens is preferably obtained by curing a curable resin composition, but the curable resin composition preferably includes a compound having at least one epoxy group as an organic resin component. The curable resin composition may be an organic-inorganic composite resin composition having an inorganic component.
In the present invention, as described above, the lens is preferably obtained by curing a curable resin composition. Thus, a lens unit comprising the light-shielding film of the present invention and a lens, the lens unit having reflow resistance, and the lens is obtained by curing a curable resin composition. A lens unit that is also one of the preferred embodiments of the present invention. Among these, a lens obtained by cationically curing a curable resin composition containing an epoxy group-containing compound as a main resin material and containing a cationic curing catalyst such as a thermosetting curing agent is preferable.

As the compound having at least one epoxy group, the compounds described in the epoxy group-containing compound described later as an example of the cured resin contained in the cured resin film can be suitably used. Among them, epibis type glycidyl ether type epoxy resin; novolak aralkyl type glycidyl ether type epoxy resin; aromatic crystalline epoxy resin; aliphatic glycidyl ether type epoxy resin; epoxy resin having epoxy cyclohexane skeleton; glycidyl ester type epoxy Resin; Tertiary amine-containing glycidyl ether type epoxy resin and the like are preferable. Moreover, what contains non-hardening components, such as a thermoplastic resin, and a low molecular weight curable compound can also be used as curable resin. As a use form of the curable resin composition (thermosetting epoxy resin composition) used for the lens, a form described as a cured resin film to be described later can be suitably used, and in particular, a thermal latent curing agent is used. Form is preferred. In addition, since curable resin composition is used for a lens use, it is preferable that black fine particles are not included.

The organic-inorganic composite resin composition preferably contains an organic resin and inorganic fine particles or organopolysiloxane. Organic resins having a high Abbe number are those having an Abbe number of 45 or more, forms that are curable resins, forms that essentially contain an alicyclic epoxy compound, and those having a molecular weight of 700 or more. Form is preferred. The inorganic fine particles have a form obtained by a wet method, a form having an average particle diameter of 400 nm or less, and a pH of 3.4 to 11 at 25 ° C. when dispersed in a solution. Form is preferred. As an organic inorganic composite resin composition, the form in which an unsaturated bond is 10 mass% or less and the form containing a flexible component are preferable.

The lens preferably has a thickness of less than 1 mm. By setting the thickness of the lens (the maximum thickness of the region where the image is captured) to less than 1 mm, the optical path length can be shortened and the lens unit can be further reduced, combined with the use of the light-shielding film. The thickness of the lens is more preferably less than 800 μm, and still more preferably less than 500 μm.
The Abbe number of the lens is not particularly limited. For example, when the Abbe number is 45 or more, the wavelength dispersion of light is reduced, the resolution is increased, and the optical characteristics can be improved. If it is less than 45, for example, bleeding may be observed, sufficient optical characteristics may not be exhibited, and a material suitable for the lens unit may not be obtained. The Abbe number is more preferably 50 or more, still more preferably 55 or more, particularly preferably 58 or more, and most preferably 60 or more.

The lens constituting the lens unit is a single lens whose optical properties (Abbe number, refractive index, etc.) and lens shape (concave, convex, curvature, etc.) are controlled according to the target resolution, or Used in combination. The number of lenses used may be one, or two or more. In the case of a single lens, it is preferable to use a lens having a high Abbe number in that the wavelength dispersion of light is reduced, the resolution is increased, and the optical characteristics are excellent. The combination is arbitrary, and various combinations can be applied. For example, it is preferable to use a combination of a lens having a high Abbe number and a lens having a low Abbe number.

The lens unit is not particularly limited as long as it includes a light-shielding film and a lens, but a form having other members such as an infrared cut filter, a sea moss sensor, a barrel, and an adhesive is preferable. The adhesive is used to fix a member such as a lens or a light shielding film to the unit.
The arrangement of each component of the lens unit is not particularly limited as long as the characteristics as the lens unit are exhibited. However, as described above, the light-shielding film is attached to the edge where the light-shielding layer fixes the lens. It is preferable that it is the arrangement | positioning. As the positional relationship between the light-shielding film and the lens, there are a form in which the lens is on the incident light side and a form in which the light-shielding film is on the incident light side. It is preferable that two light-shielding films are arranged on the incident light side from the lens.
As the shape of the light-shielding film, as described above, it is preferable that the light-shielding layer has a ring shape and the center of the ring is a cavity. With such an arrangement and shape, the light shielding function can be sufficiently exhibited. Specifically, as schematically shown in FIG. 10B, when the central portion is a transparent film, the light path length is increased by having the light-shielding film. On the other hand, if the central portion is hollow, the optical path length does not increase as schematically shown in FIG. Since the lens unit is required to be downsized, it is preferable that the lens unit has a light-shielding layer in a ring shape and has a hollow center. In the case of a light-shielding film, if a light-shielding film is provided between the lens and the seamos sensor, the optical path length can be shortened by reducing the thickness of the light-shielding film located between the lens and the seamos sensor. The lens unit can be made smaller and the thickness of the unit can be made thinner.

In the lens unit, the arrangement of the light-shielding film and the lens is arranged in the order of the light-shielding film, one or more lenses, and the Cimos sensor along the traveling direction of the incident light as shown in FIG. Form is preferred. When there are two or more lenses, a form in which a light-shielding film is provided on each lens is more preferable. Thus, if a plurality of light-shielding films are used, unnecessary light can be sufficiently blocked. The light shielding film may be disposed between the lenses. In addition, when using other functional layers, such as the infrared cut filter mentioned later, it is preferable to provide in the form where those effects are fully exhibited. In FIG. 7, the infrared cut filter is disposed at a position closest to the sea moss sensor. The infrared cut filter may be disposed so as to be positioned on the incident light surface of the lens unit.

The size of the lens unit of the present invention is preferably small because it can be suitably used for various applications. The thickness of the lens unit is preferably 50 mm or less. By setting it as such thickness, it can use suitably for various optical members, such as a camera module. More preferably, it is 30 mm or less as a thickness of a lens unit, More preferably, it is 10 mm or less.

When a light-shielding film having a transparent film at the center is used, the length of the lens unit can be made smaller as the light-shielding film located between the lens and the sea moss sensor is thinner. Specifically, the camera module has a light-shielding film, a lens, and a seamos sensor. 7 and 10 schematically show an example of the camera module. Note that these figures refer to materials from the Electronic Journal 81st Technical Seminar (Electronic Journal 81st Technical Seminar). When the light-shielding film is arranged on the camera module as shown in FIG. 10B, the focal length is extended, so that the back focus is extended and the module is enlarged. As shown in FIG. 10B, when the light-shielding film is positioned between the incident light surface and the lens and the Simos sensor, the thickness of the light-shielding film is t and the refractive index n is about 1.5, the back focus Is extended by about t / 3, and the module becomes large. However, the light-shielding film can be made thin, the focal length can be shortened, and the module can be made small. Thereby, for example, the optical path length of an optical size of 1/10 inch is preferably 120% or less in the case of no light-shielding film. More preferably, it is 110% or less, More preferably, it is 105% or less.

The present invention has the above-described configuration, can produce an optical member such as a light-shielding film having a plurality of minute surface irregularities having excellent heat resistance and reflow resistance, a curable resin film before curing, Alternatively, a method for producing a cured resin film capable of suppressing the occurrence of problems in production that curl occurs in the cured resin film obtained by curing the curable resin film, and produced by such a production method, Resin films suitable for optical members such as light diffusing films and light-shielding films that require high performance and quality, and light-scattering films, light-shielding films, and lens units as their uses. It is suitably used for various applications such as device applications, display device applications, mechanical parts, and electrical / electronic parts.

Drawing 1 is a mimetic diagram showing an example of the manufacturing method of the cured resin film of the present invention. FIG. 2 is a schematic diagram showing the form of the laminated film in the production method of the present invention. FIG. 3 shows one of the cross-sectional schematic diagrams of the cured resin film when the line roughness (Ra) of the cured resin film produced by the production method of the present invention is determined. FIG. 4 shows one of the cross-sectional schematic diagrams of the cured resin film in the case of obtaining the ten-point average roughness (Rz) of the cured resin film produced by the production method of the present invention. FIG. 5 shows one of the schematic cross-sectional views of the cured resin film in the case of obtaining the average distance (S) between the local peaks of the cured resin film produced by the production method of the present invention. FIG. 6 is a schematic cross-sectional view showing one preferred embodiment of the light-shielding film of the present invention. FIG. 7 is a schematic cross-sectional view showing the configuration of a camera module which is one of the preferred embodiments of the lens unit of the present invention. FIG. 8 is a schematic cross-sectional view showing the relationship between the light-shielding film and the lens in the lens unit of the present invention. FIG. 9 is a schematic plan view showing one preferred form of the light-shielding film in the lens unit of the present invention. FIG. 10 is a schematic diagram showing the extension of back focus depending on the presence or absence of a light-shielding film. FIG. 11 is a schematic view showing a method for measuring the curl of the resin film.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by weight” and “%” means “mass%”.

In the following examples etc., the following measurement items were evaluated for the obtained cured resin films. Measurement items and measurement methods are as follows.
(Glossiness measurement)
Regarding the obtained films (transfer film as a curable resin film and transfer cured film), the glossiness of the surface subjected to the transfer treatment was measured.
The glossiness was determined by measuring the glossiness at a measurement angle (θ) of 60 degrees using a gloss meter (VG-2000) manufactured by Nippon Denshoku Industries Co., Ltd.

(Solid content of film)
The solid content in the precursor film (curable resin film) to be transferred was determined as follows. That is, using a small piece of film as a sample, TG-DTA (manufactured by BRUKER AXS, TG-DTA 2000SA) was used to measure the weight loss from room temperature to 350 ° C. at a heating rate of 10 ° / min. Was the solvent content, and the remainder was the solid content.

(Heat resistance test)
The produced cured resin film was cut into the following sizes and subjected to a heat resistance test as a test piece.
The size of the test piece is 50 mm × 10 mm.
About the said test piece, the heating test was done and the dimensional change of the length direction of the test piece before and behind a test was measured and evaluated. The heating test was performed by heating at 260 ° C. for 2 minutes (injecting a test piece into a hot air dryer heated to 260 ° C. and taking it out after 2 minutes). At this time, when the rate of dimensional change in the length direction before and after the heating test was less than 3%, Rank A was ranked 3% or more.

(Visible light transmittance)
About the obtained cured resin film, the transmittance | permeability in 380-780 nm was measured using the ultraviolet visible spectrophotometer needle | hook (Shimadzu UV-3100 (made by Shimadzu Corporation)).

(Evaluation of surface irregularities)
The surface shape of the transfer surface in the obtained film (transfer film as a curable resin film and transfer curable film as a curable resin film) was measured with a laser microscope (Color 3D laser microscope (VK-9700) manufactured by KEYENCE). It was evaluated by observation of a microscopic image used and measurement of line roughness according to Japanese Industrial Standard (JIS) B0601-1994. The measurement conditions of the line roughness are as follows. In addition, a measured numerical value is a value averaged with the number of measurement points being 3.

The measurement conditions of the line roughness of the surface of the transfer surface in the obtained film (transfer film as a curable resin film and transfer curable film as a curable resin film) are as follows.
Objective lens: 20x Zoom: 1.0x Measurement pitch: RPD
Measurement mode: Surface shape measurement area: Surface measurement quality: Ultra high definition analysis software: VK-9700 / VK-8700 Shape analysis application VK-HIAI
Analysis surface (image) tilt correction: quadratic surface correction (automatic)
Analysis length (reference length l: 500 μm
Analysis line tilt correction: straight line (automatic)

(The elastic modulus of the transfer roll)
A test piece (length 80 mm, width 10 mm, thickness 4 mm) of the same material as the transfer roll used in the examples and comparative examples was prepared, and the flexural modulus was measured by the method described in JIS K 7171 2008. Was the elastic modulus of the roll material.
It is confirmed that the elastic modulus is less than 5 × 10 ⁴ MPa for the rubber of the roll made of rubber used in each example and comparative example, and the elastic modulus is 5 × 10 ⁴ MPa or more for the SUS of the roll made of SUS. did.

(Curl evaluation method)
As shown in FIG. 11, a curable resin film having a width of 30 cm and a length of 30 cm was placed on a table to evaluate whether to curl. A curl having a diameter (R) of 2 cm or less was curled, and a curled state having an end height (h) of 5 cm or less was not curled.

Preparation Example 1
(Preparation of polyamic acid solution)
A reactor equipped with a thermometer, a cooling pipe, a gas introduction pipe, and a stirrer was prepared. In this reactor, I.I. S. Poly (amide) imide varnish Pyre-ML RC5083 (trade name, solid content: 18.5%) manufactured by T company, as a black material, graft carbon black solution Epotone LY (trade name, carbon black concentration 7. 8%), BYK-306 (trade name, solid content: 12.5%) manufactured by Big Chemie Japan as a surface conditioner was charged at a ratio (mass%) shown in Table 1 and a two-stage paddle stirring blade was used. After mixing for 60 minutes under a nitrogen atmosphere, heat is applied by pressure filtration using a pressure filter (ADVANTEC, KST-293-10-JA, trade name) made of SUS 300 mesh. A polyamic acid solution as a curable resin composition was obtained.

[Production of curable resin film]
The polyamic acid solution obtained in Preparation Example 1 was formed into a film by the film formation method described in the following Preparation Examples 1) to 3) to obtain curable resin films, respectively. Table 2 shows the results of measuring the volatile content of the obtained curable resin film .
Production Example 1) A PET film having a smooth surface was used as a base material, a polyamic acid solution was applied onto the base material, dried at a temperature of 130 ° C. for 10 minutes and then released to obtain a curable resin film.
Production Example 2) Using a PET film having a smooth surface as a base material, a polyamic acid solution was applied onto the base material, dried at a temperature of 120 ° C. for 10 minutes, and then released to obtain a curable resin film.
Production Example 3) Using a mat PET film (mold film) having a concavo-convex shape on the surface as a base material, a polyamic acid solution was applied on the base material, dried at a temperature of 145 ° C. for 10 minutes, and then released. A curable resin film was obtained.

Examples 1-3, Comparative Examples 1-2
Each of the curable resin films obtained in Production Examples 1) to 3) and a mold film are laminated, and two rolls are used as a pressurizing and heating medium and passed between the two rolls. An uneven surface was formed on one surface of the curable resin film under the transfer conditions shown in FIG. As a casting film (transfer material), PET-1 (Tetsujin DuPont mat pet film, brand: PSG [trade name], thickness 100 μm) was used. As a configuration of the two rolls as the pressurizing and heating medium, a roll whose surface layer is made of rubber is used on the side in contact with the curable resin film, and a SUS roll is used on the side in contact with the mold film.
After the transfer of the surface irregularities, the mold was released, and the resulting resin film was cured by heating at 280 ° C. for 60 minutes. The formation of curls was observed and the surface gloss was measured. The results are shown in Table 2.

In addition, the said Example 3 is the transfer method 3 (1 and 2 were combined) of this application, and the curable resin film obtained is a double-sided uneven | corrugated shape.

Comparative Example 3
A curable resin film having a concavo-convex surface was formed by forming a curable resin film using a polyamic acid solution and peeling it in the same manner as in Preparation Example 1 except that a mat film was used as a base material. It was. The curable resin film was cured by heating at 280 ° C. for 1 hour to obtain a cured resin film. As a result, curling was remarkable.

Comparative Example 4
The curable resin film obtained in Production Example 2 was subjected to a mat roll treatment using a heating embossing machine to obtain a curable resin film having a surface uneven shape. After peeling from the substrate, a cured resin film was obtained by heating at 280 ° C. for 1 hour to cure. As a result, curling was remarkable.

From the results of Table 2, in Examples 1 to 3 in which the process of applying pressure and heating in the state where the curable resin film and the mold film were laminated, the generation of curl of the cured resin film is sufficiently suppressed. I understood. It was found that in Comparative Example 1 in which pressure was not substantially applied and in Comparative Example 2 in which heating was not substantially performed, the occurrence of curling was remarkable in the obtained cured resin film. In these comparative examples, the uneven shape transfer was not sufficient, and the gloss reduction effect associated with the uneven shape transfer was not sufficiently exhibited. In addition, the occurrence of curling was also remarkable in Comparative Example 3 in which no pressurization and heating were performed and in Comparative Example 4 in which a cured resin film was obtained by mat roll treatment without using a mold film.

As described above, when pressurization and heating are not performed in a state where the curable resin film and the mold film are laminated, that is, when pressurization is not performed, when heating is not performed, or when neither is performed, it is performed thereafter. When the curable resin film is cured, significant curling occurs. In addition, the transferability is also affected, and the gloss reduction effect due to the uneven shape transfer is impaired. This is considered to be because the effects of curing shrinkage and solvent volatilization of the curable resin film were alleviated by pressurization and heating to the laminated film performed in the previous process, thereby suppressing the occurrence of problems in the manufacturing process.
In the said Example, it is shown that the advantageous effect of this invention is show | played only by pressurizing and heating in the state which laminated | stacked the curable resin film and the casting_mold | template film. As long as at least the mold film is laminated on the curable resin film and the surface unevenness forming treatment is performed, it is considered that any method is affected by shrinkage and volatile components during curing. If it is the manufacturing method of this invention, it will become possible to suppress the malfunction brought about by hardening a curable resin film.
In the above-described embodiment, a curable resin film and a mat pet film are laminated, pressed and heated using a roll, the linear pressure between the rolls is 5 N / mm or more, and the roll temperature is 50 ° C. However, since the action mechanism in the transfer using the mold film in various forms and the pressurization and / or the heating medium is the same, the production method of the present invention can be applied in various forms disclosed in the present specification, It can be said that advantageous effects can be exhibited.

1: rubber roll 2: SUS roll 3: curable resin film 4: matte film 5: matte roll 6: base material 7: cured resin film 8: light-shielding film 9: lens 10: infrared cut filter 11: barrel 12: sensor Lens 13: Edge 14: Resin film A
15: Surface uneven film B
16: Other film C
f: roughness curve m: average line R: diameter of the resin film curled in a cylindrical shape h: height of the end of the resin film

Claims (9)

A light- shielding film comprising a light- scattering film,
Light-shielding film, the transmittance for light with a wavelength of 550nm is Ri der less than 1%,
The light scattering film comprises a cured resin film,
The cured resin film is a method for producing a cured resin film by forming an uneven surface by transfer on at least one surface of a curable resin film formed from a curable resin composition, and curing the curable resin film. It is manufactured by
The manufacturing method includes a step of applying pressure and heating in a state in which a curable resin film and a mold film are laminated using a mold film for forming a surface uneven shape . 2. The light-shielding film according to claim 1, wherein the production method includes pressurization and heating in a state where the curable resin film has a volatile component . In the manufacturing method, a heating medium having a surface temperature of 50 ° C. or more is heated by contacting the curable resin film with the mold film, and the surface temperature of the heating medium in contact with the curable resin film is in contact with the mold film. The light-shielding film according to claim 1, wherein the light-shielding film is made higher than a surface temperature. The said manufacturing method pressurizes and heats using a roll as a pressurization and a heating medium, The light-shielding film in any one of Claims 1-3 characterized by the above-mentioned. In the manufacturing method, the surface layer of at least one of the two rolls is elastically pressed and heated by passing between at least two rolls in a state where the curable resin film and the mold film are laminated. The light-shielding film according to claim 4, wherein the curable resin film is in contact with a surface layer of a roll which is an elastic body. The light-shielding film according to claim 4 or 5, wherein the production method sets a linear pressure between rolls to 1 to 100 N / mm. The light-shielding film according to claim 1, wherein the cured resin composition contains a black material. The light-shielding film according to claim 1, wherein the cured resin film contains at least one selected from the group consisting of a polyimide resin, a polyamideimide resin, and a cationic cured resin. A lens unit and a light-shielding film and the lens according to claim 1,
The lens unit is a lens unit for a photographing element.

Images