Dry film, cured product thereof, and electronic component

Abstract

To provide a dry film that is superior in terms of optical properties, sealing performance for semiconductor elements, low-temperature curability, storage stability, and handling characteristics.SOLUTION: A dry film includes a radically polymerizable organic compound and a thermal radical polymerization initiator, where the thermal radical polymerization initiator has a 10-hour half-life temperature of 60°C or more and 170°C or less.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a dry film and an electronic device including a cured product thereof.

Background Art

[0002] Dry films are used as encapsulants for semiconductor elements. In particular, in an optical sensor module, dry films with excellent processability and optical suitability are required for the materials arranged around the partition walls and each light-emitting element of RGB in a display using LEDs. For example, Patent Document 1 discloses a dry film composed of a photoinitiator. Conventionally, as a method for encapsulating LEDs, a method is known in which a dry film is embedded in a region where a plurality of LEDs are arranged by hot pressing or the like, and the dry film is cured by ultraviolet irradiation. Further, Patent Document 2 discloses a light-shielding dry film composed of a polymer resin having a specific glass transition temperature and weight-average molecular weight, an epoxy-based material, and carbon black.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, micro-LEDs, which have been actively developed, have a narrow interval of 10 to 250 μm between LEDs, and it is necessary to encapsulate these minute grooves without gaps. However, conventional dry films It did not embed sufficiently between the grooves, resulting in voids (also referred to as sealing properties). After sealing, the cured product of the dry film was required to maintain high transparency for a long period without impairing the brightness of the micro LED element. On the other hand, in applications where color mixing of adjacent light-emitting elements is suppressed, excellent optical properties such as high light-shielding properties are required. In addition, from the viewpoints of reducing thermal damage to components and shortening the sealing process time, a dry film that cures quickly at low temperatures was required (also referred to as low-temperature curability). Furthermore, there was a problem that the curing reaction progressed after a long period of time, deteriorating the sealing performance, and it was required to maintain stable sealing properties even after long-term storage (also referred to as storage stability). Moreover, a dry film with no tack on the surface and easy handling during work was required (also referred to as handleability). Therefore, an object of the present invention is to provide a dry film excellent in optical properties, sealing properties, low-temperature curability, storage stability, and handleability.

Means for Solving the Problems

[0005]

[0006] ​​​​​​​​​​​[1]: A dry film containing a radically polymerizable organic compound and a thermal radical polymerization initiator which has a 10-hour half-life temperature of the thermal radical polymerization initiator of 60°C or higher and 170°C or lower Dry film. [2]: The dry film according to [1], wherein the radically polymerizable organic compound contains a radically polymerizable polymer (a) having a glass transition temperature of -50°C or higher and 90°C or lower. [3]: The dry film according to [1], wherein the radically polymerizable organic compound contains at least one of a radically polymerizable oligomer (b) and a radically polymerizable monomer (c) that are liquid at normal temperature and pressure. [4]: The dry film according to [2] or [3], characterized in that the storage modulus (G'80) at 80°C obtained by dynamic viscoelasticity measurement is 5×10 4 Pa to 5×10 7 Pa. [5]: The dry film according to [4], characterized in that the loss tangent (tanδ80) at 80°C obtained by dynamic viscoelasticity measurement is 0.3 to 0.7. [6]: The dry film according to [5], wherein the dynamic friction coefficient of the surface of the dry film is 0.5 or less. [7]: The dry film according to [6], which contains 0.1 to 80% by mass of a colorant in 100% by mass of the total solid content of the dry film. [8]: An electronic device including a cured product of the dry film according to [7].

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a dry film, a cured product, and an electronic component that are excellent in optical properties, sealing properties, low-temperature curability, storage stability, and handleability.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Mode for Carrying Out the Invention

[0009] Hereinafter, the dry film of the present invention will be described more specifically. Note that the embodiments described below are examples of the present invention. The present invention is not limited to the following embodiments, and modifications implemented within the scope of not changing the gist of the present invention are also included. In this specification, a numerical range specified using "~" includes the numerical values described before and after "~" as the lower limit value and the upper limit value range. "(Meth)acrylic acid" means acrylic acid and methacrylic acid. Further, various components appearing in this specification may be each independently used alone or in combination of two or more, unless otherwise noted. When two or more are used in combination, the content rate uses the total value. FIG. 1 is a schematic cross-sectional view of a dry film 11 according to an embodiment of the present invention. The dry film 11 shown in FIG. 1(A) has a two-layer structure in which a release liner 12 is laminated on the dry film 11. As shown in (b), a protective film 13 may be formed on the surface opposite to the surface on which the release liner 12 of the dry film 11 is laminated. The dry film 11 may be provided with another layer between the dry film and the release liner 12 or the protective film 13, if necessary.

[0010] The dry film of the present invention is preferably used for sealing a semiconductor element. In particular​​​​​​​​​ It is preferable to use a plurality of optical semiconductor elements used as a light source for a display in the form of a fixing agent. The fixing agent is preferably used as a highly transparent fixing agent that does not impair the brightness of the semiconductor element. In addition it is also preferable to use it in the form of a light-shielding layer (also referred to as a partition wall) that prevents color mixing of light. A display using a plurality of optical semiconductor elements as a light source includes, for example, an organic EL display panel, a liquid crystal display panel, a micro LED display panel, a plasma display panel, an electronic paper etc., displays that require high quality, such as those mentioned above.

[0011] The dry film is preferably laminated by directly adhering it to the adherend. As the adherend in addition to the plurality of optical semiconductor elements (micro LEDs) described above, those having a substrate electrode portion made of metal and those having a plurality of optical semiconductor element portions such as a backlight module and an organic EL are exemplified. Further, acrylic, polycarbonate, epoxy, polyimide, glass It may also have a substrate such as fiber, glass epoxy, ITO or polyethylene terephthalate. Since the dry film has high followability to the uneven surface, a method of using it to fill the space between a plurality of optical semiconductor elements while following them is suitable. By filling the dry film between the optical semiconductor elements and curing it, the cured product of the dry film functions as a fixing agent for fixing the adjacent optical semiconductor elements on the substrate. When the dry film contains a colorant, the cured product of the dry film filled and cured between the optical semiconductor elements blocks the light sources of the adjacent optical semiconductor elements and functions as a partition wall that prevents color mixing of light. In particular, since the dry film can follow micro-sized optical semiconductor elements, the optical semiconductor element is a micro LED Since the dry film can follow micro-sized optical semiconductor elements, the optical semiconductor element is a micro LED Since the dry film can follow micro-sized optical semiconductor elements, the optical semiconductor element is a micro LED Since the dry film can follow micro-sized optical semiconductor elements, the optical semiconductor element is a micro LED semiconductor elements, and as the optical semiconductor element, a micro LED is more preferable. When the dry film contains a colorant, the micro LED display panel It is more preferable to use a dry film as the partition wall of the panel. Hereinafter, an example of the step of forming a fixing agent or a partition wall will be described with reference to FIG. 2.

[0012] Step (a): Step of placing a dry film As shown in an example in FIG. 2(a), a dry film 11 is placed on a substrate having a plurality of optical semiconductor elements. The placement preferably directly covers the optical semiconductor elements. Note that, when there is a release liner, it may be peeled off immediately after placement, or may be peeled off after the pressing step described below. In the present specification, the plurality of optical semiconductor elements are not particularly limited as long as they are two or more optical semiconductor elements. Further, the emission color of the optical semiconductor element is not particularly limited, and an organic EL light-emitting element or an LED optical semiconductor element can be applied. Examples of the emission color include red, green, and blue. The size of the optical semiconductor element is preferably such that the thickness is 100 μm or less and the area in plan view is 40,000 μm 2 or less, more preferably such that the thickness is 50 μm or less and the area in plan view is 10,000 μm 2 or less, even more preferably such that the thickness is 20 μm or less and the area in plan view is 2,500 μm 2 or less. The interval between the optical semiconductor elements placed on the substrate is, for example, 10 to 5,000 μm. When red, green, and blue optical semiconductor elements are set as one pixel and placed on the substrate, the interval between the pixels is, for example, 10 to 2,000 μm, preferably 20 to 1,800 μm, and more preferably 500 to 1,500 μm. The interval between the optical semiconductor elements in one pixel is, for example, 10 to 250 μm, preferably 10 to 100 μm, and more preferably 20 to 60 μm.​​​​ Preferred.

[0013] Step (b): Pressing step As shown in FIG. 2(b), the dry film 11 is flowed by pressing and filled between a plurality of optical semiconductor elements. The dry film 11 filled between the plurality of optical semiconductor elements becomes a fixing agent or a partition wall. The pressing method is not particularly limited, but thermal pressing and vacuum pressing are preferred. From the viewpoint of the filling property of the dry film, the temperature during pressing is preferably 20 to 200°C, more preferably 50 to 150°C, even more preferably 60 to 130°C, and most preferably 80 to 120°C. Most preferred.

[0014] In order to enhance the adhesion between the optical semiconductor element and the adherend, post-pressing heat aging may be performed. The heating temperature is preferably 80 to 250°C, more preferably 100 to 220°C, and even more preferably 140 to 190°C. The heating time is preferably 30 to 300 minutes, more preferably 60 to 240 minutes, and even more preferably 90 to 180 minutes. By setting the heating temperature and heating time as described above, the residual stress of the dry film can be removed, the adhesion surface can be smoothed, and the thermosetting of the dry film forming the fixing agent or the partition wall can be promoted. After undergoing the above pressing step and heat aging step, the dry film is thermoset and becomes a cured product of the dry film (also referred to as a cured product). By curing, the toughness and durability of the fixing agent or the partition wall are improved, and the adhesion to the adherend is also increased. Heat aging may be performed after step (c) described later.

[0015] Step (c): Etching step In step (c), etching is performed to remove the cured product of the dry film on the optical semiconductor element. Or, thin it. By removing the cured product of the dry film, the luminance of the light-emitting element is increased and the visibility during light emission is ensured. The thickness of the fixing agent or the partition wall after etching is about the same as the thickness of the optoelectronic device as shown in Fig. 2(c-1), or preferably not more than the thickness of the dry film as shown in Fig. 2(c-2). Note that, even if the dry film is not completely removed from the light-emitting element, it is sufficient if it can be substantially removed, and a state where some thin films remain may be acceptable. Also, when the luminance of the light-emitting element is sufficiently ensured, the etching process may not be performed. The etching method is not particularly limited, but examples of preferred methods include wet etching such as chemical polishing using a chemical, physical polishing using an abrasive, laser etching, plasma etching using argon plasma or oxygen plasma, and dry etching such as ion beam etching. From the viewpoint of reducing surface irregularities, it is preferable to use a combination of wet etching and dry etching. Physical etching such as plasma treatment may also be used. As the etching conditions, for example, in an anisotropic plasma apparatus, using a mixed gas of CF4 / O2 / N2, dry etching may be performed under the conditions of an output of 1500 to 3000 W and 180 to 600 seconds. At this time, the gas supply amount of CF4 is, for example, 50 to 100 sccm, and the gas supply amount of O2 is, for example, 500 to 1000 sccm, and the gas supply amount of N2 is, for example, 50 to 100 sc cm. For example, the gas supply amount of CF4 is, for example, 50 to 100 sccm, the gas supply amount of O2 is, for example, 500 to 1000 sccm, and the gas supply amount of N2 is, for example, 50 to 100 sc cm. cm, and the gas supply amount of N2 is, for example, 50 to 100 sccm. For example, the gas supply amount of O2 is, for example, 500 to 1000 sccm, and the gas supply amount of N2 is, for example, 50 to 100 sccm. It is sufficient to set it to, for example, 50 to 100 sccm.

[0016] <Dry film> The dry film contains a radically polymerizable organic compound and a thermal radical polymerization initiator. The thickness of the dry film is preferably, for example, 0.5 to 100 μm, more preferably 1 to 50 μm. is preferable. By being within this range, the dry film will have excellent sealing properties. The dry film may be a single layer or a laminate of two or more layers, and the thickness can be measured by the method described in the examples below. When the dry film contains a colorant, the optical density of the dry film is preferably 3 or more. If the optical density is 3 or more, sufficient light-shielding properties can be maintained. The optical density can be adjusted according to the type and content of the colorant. Also, the optical density can be measured by the method described in the examples below. When the dry film contains a colorant, in a so-called dry film mainly based on photopolymerization, the higher the light-shielding property, the less likely light is to reach the inside of the dry film, and the more likely an uncured portion is to occur. However, in the dry film of the present application, since polymerization proceeds by heat, the internal curing proceeds uniformly, and an uncured portion inside the dry film is less likely to remain. Therefore, it is possible to cure uniformly while ensuring higher light-shielding properties. When the dry film does not contain a colorant, in a so-called dry film mainly based on photopolymerization, the transparency is likely to decrease mainly due to yellowing caused by the remaining photoinitiator of radical polymerization. However, in the dry film of the present application, since a thermal radical polymerization initiator is used, it is less likely to yellow. Therefore, it is possible to cure while ensuring higher transparency. Also, in a so-called dry film mainly based on a thermal crosslinking reaction, when a crosslinking agent such as isocyanate reacts, gas is generated, and the transparency is likely to decrease mainly due to the foam remaining in the dry film. However, in the dry film of the present application, since a thermal radical polymerization initiator is used, gas is less likely to be generated, and higher transparency can be ensured. Note that the transparency can be measured by the method described in the examples below.

[0017] The storage elastic modulus (G’80) at 80 °C obtained by measuring the dynamic viscoelasticity of the dry film is 5×10 4 Pa to 5×10 7 Pa, preferably 10×10 4 Pa to 1×10 7 Pa, more preferably 50×10 4 Pa to 5×10 6 Pa, and even more preferred. By setting G’80 to 5×10 4 Pa or more, the pressure applied to the dry film in the pressing step of sealing the semiconductor element is likely to be evenly diffused. By setting G’80 to less than 5×10 Pa, it becomes easy to closely adhere following the semiconductor element, resulting in excellent sealing properties of the semiconductor element. G’80 is a value measured under the conditions of a shear mode and 1 Hz to 10 Hz, and can be measured by the method described in the examples below. 7 Pa or less, it becomes easy to closely adhere following the semiconductor element, resulting in excellent sealing properties of the semiconductor element. G’80 is a value measured under the conditions of a shear mode and 1 Hz to 10 Hz, and can be measured by the method described in the examples below. By adjusting G’80 within the above range, the dry film can exhibit excellent fluidity in the pressing process. Note that G’80 of the present invention can be adjusted by the type, composition, content of the radically polymerizable organic compound, and the content of the thermal radical polymerization initiator. When containing the radically polymerizable polymer (a) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low weight average molecular weight and / or those having a low glass transition temperature. When it is desired to increase G’80, the adjustment can be made conversely. When containing the radically polymerizable oligomer (b) and / or the radically polymerizable monomer (c) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low viscosity. Note that G’80 of the present invention can be adjusted by the type, composition, content of the radically polymerizable organic compound, and the content of the thermal radical polymerization initiator. When containing the radically polymerizable polymer (a) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low weight average molecular weight and / or those having a low glass transition temperature. When it is desired to increase G’80, the adjustment can be made conversely. When containing the radically polymerizable oligomer (b) and / or the radically polymerizable monomer (c) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low viscosity. By adjusting G’80 within the above range, the dry film can exhibit excellent fluidity in the pressing process. By adjusting G’80 within the above range, the dry film can exhibit excellent fluidity in the pressing process.

[0018] Note that G’80 of the present invention can be adjusted by the type, composition, content of the radically polymerizable organic compound, and the content of the thermal radical polymerization initiator. When containing the radically polymerizable polymer (a) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low weight average molecular weight and / or those having a low glass transition temperature. When it is desired to increase G’80, the adjustment can be made conversely. When containing the radically polymerizable oligomer (b) and / or the radically polymerizable monomer (c) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low viscosity. Note that G’80 of the present invention can be adjusted by the type, composition, content of the radically polymerizable organic compound, and the content of the thermal radical polymerization initiator. When containing the radically polymerizable polymer (a) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low weight average molecular weight and / or those having a low glass transition temperature. When it is desired to increase G’80, the adjustment can be made conversely. When containing the radically polymerizable oligomer (b) and / or the radically polymerizable monomer (c) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low viscosity. When containing the radically polymerizable polymer (a) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low weight average molecular weight and / or those having a low glass transition temperature. When it is desired to increase G’80, the adjustment can be made conversely. When containing the radically polymerizable oligomer (b) and / or the radically polymerizable monomer (c) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low viscosity. When containing the radically polymerizable polymer (a) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low weight average molecular weight and / or those having a low glass transition temperature. When it is desired to increase G’80, the adjustment can be made conversely. When containing the radically polymerizable oligomer (b) and / or the radically polymerizable monomer (c) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low viscosity. When containing the radically polymerizable polymer (a) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low weight average molecular weight and / or those having a low glass transition temperature. When it is desired to increase G’80, the adjustment can be made conversely. When containing the radically polymerizable oligomer (b) and / or the radically polymerizable monomer (c) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low viscosity. When containing the radically polymerizable oligomer (b) and / or the radically polymerizable monomer (c) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low viscosity. When containing the radically polymerizable oligomer (b) and / or the radically polymerizable monomer (c) as the radically polymerizable organic compound, lowering G’80 can be achieved by increasing the content of those having a low viscosity. When it is desired to increase G’80, the opposite adjustment may be made. Also, G’80 can be increased by increasing the content of the thermal radical polymerization initiator. When it is desired to decrease G’80, the opposite adjustment may be made. The loss tangent (tanδ80) at 80 °C obtained by measuring the dynamic viscoelasticity of the dry film is preferably 0.3 to 0.7, more preferably 0.4 to 0.6. By setting tanδ80 to 0.3 or more, the pressure applied to the dry film in the press step for encapsulating the semiconductor element is likely to be uniformly diffused. By setting tanδ80 to 0.7 or less, it becomes easy to closely adhere following the semiconductor element, and the encapsulation property of the semiconductor element becomes excellent. tanδ80 can be measured in the same manner as G’80.

[0019] By adjusting tanδ80 within the above range, the diffusibility of the pressure of the dry film in the press step can be enhanced. tanδ80 can be adjusted according to the type, composition and content of the radically polymerizable organic compound, and the content of the thermal radical polymerization initiator. When containing a radically polymerizable polymer (a) as the radically polymerizable organic compound, tanδ80 can be decreased by increasing the content of those having a low weight average molecular weight and / or a low glass transition temperature. When it is desired to increase tanδ80, the opposite adjustment may be made. When containing a radically polymerizable oligomer (b) and / or a radically polymerizable monomer (c) as the radically polymerizable organic compound, tanδ80 can be decreased by increasing the content of those having a low viscosity. When it is desired to increase tanδ80, the opposite adjustment may be made. Also, for the thermal radical When it is desired to increase G’80, the opposite adjustment may be made. Also, G’80 can be increased by increasing the content of the thermal radical polymerization initiator. When it is desired to decrease G’80, the opposite adjustment may be made. The loss tangent (tanδ80) at 80 °C obtained by measuring the dynamic viscoelasticity of the dry film is preferably 0.3 to 0.7, more preferably 0.4 to 0.6. By setting tanδ80 to 0.3 or more, the pressure applied to the dry film in the press step for encapsulating the semiconductor element is likely to be uniformly diffused. By setting tanδ80 to 0.7 or less, it becomes easy to closely adhere following the semiconductor element, and the encapsulation property of the semiconductor element becomes excellent. tanδ80 can be measured in the same manner as G’80. By adjusting tanδ80 within the above range, the diffusibility of the pressure of the dry film in the press step can be enhanced. tanδ80 can be adjusted according to the type, composition and content of the radically polymerizable organic compound, and the content of the thermal radical polymerization initiator. When containing a radically polymerizable polymer (a) as the radically polymerizable organic compound, tanδ80 can be decreased by increasing the content of those having a low weight average molecular weight and / or a low glass transition temperature. When it is desired to increase tanδ80, the opposite adjustment may be made. When containing a radically polymerizable oligomer (b) and / or a radically polymerizable monomer (c) as the radically polymerizable organic compound, tanδ80 can be decreased by increasing the content of those having a low viscosity. When it is desired to increase tanδ80, the opposite adjustment may be made. Also, for the thermal radical When it is desired to increase G’80, the opposite adjustment may be made. Also, G’80 can be increased by increasing the content of the thermal radical polymerization initiator. When it is desired to decrease G’80, the opposite adjustment may be made. The loss tangent (tanδ80) at 80 °C obtained by measuring the dynamic viscoelasticity of the dry film is preferably 0.3 to 0.7, more preferably 0.4 to 0.6. By setting tanδ80 to 0.3 or more, the pressure applied to the dry film in the press step for encapsulating the semiconductor element is likely to be uniformly diffused. By setting tanδ80 to 0.7 or less, it becomes easy to closely adhere following the semiconductor element, and the encapsulation property of the semiconductor element becomes excellent. tanδ80 can be measured in the same manner as G’80. By adjusting tanδ80 within the above range, the diffusibility of the pressure of the dry film in the press step can be enhanced. tanδ80 can be adjusted according to the type, composition and content of the radically polymerizable organic compound, and the content of the thermal radical polymerization initiator. When containing a radically polymerizable polymer (a) as the radically polymerizable organic compound, tanδ80 can be decreased by increasing the content of those having a low weight average molecular weight and / or a low glass transition temperature. When it is desired to increase tanδ80, the opposite adjustment may be made. When containing a radically polymerizable oligomer (b) and / or a radically polymerizable monomer (c) as the radically polymerizable organic compound, tanδ80 can be decreased by increasing the content of those having a low viscosity. When it is desired to increase tanδ80, the opposite adjustment may be made. Also, for the thermal radical When it is desired to increase G’80, the opposite adjustment may be made. Also, G’80 can be increased by increasing the content of the thermal radical polymerization initiator. When it is desired to decrease G’80, the opposite adjustment may be made. The loss tangent (tanδ80) at 80 °C obtained by measuring the dynamic viscoelasticity of the dry film is preferably 0.3 to 0.7, more preferably 0.4 to 0.6. By setting tanδ80 to 0.3 or more, the pressure applied to the dry film in the press step for encapsulating the semiconductor element is likely to be uniformly diffused. By setting tanδ80 to 0.7 or less, it becomes easy to closely adhere following the semiconductor element, and the encapsulation property of the semiconductor element becomes excellent. tanδ80 can be measured in the same manner as G’80. By adjusting tanδ80 within the above range, the diffusibility of the pressure of the dry film in the press step can be enhanced. By increasing the content of the coincidence initiator, tanδ80 can be increased. When it is desired to lower tanδ80, the adjustment can be made conversely. When it is desired to lower it, the adjustment can be made conversely.

[0020] The coefficient of kinetic friction on the surface of the dry film is preferably 0.5 or less, more preferably 0.4 or less, even more preferably 0.35 or less. By setting the coefficient of kinetic friction to 0 .5 or less, the flow of the dry film at the contact surface between the semiconductor element and the dry film in the pressing step of sealing the semiconductor element becomes good, and the sealing property of the semiconductor element becomes excellent. In addition, when adhering the adherend such as a semiconductor element to the dry film, air bubbles are less likely to enter, and the transparency becomes excellent. Note that the lower limit of the coefficient of kinetic friction is 0 or more, and the closer it is to 0, the more preferable it is. The coefficient of kinetic friction can be measured, for example, by the method described in the examples below. The coefficient of kinetic friction can be adjusted by the type, composition and content of the radically polymerizable organic compound, and the content of the thermal radical polymerization initiator. When containing the radically polymerizable polymer (a) as the radically polymerizable organic compound, the coefficient of kinetic friction can be lowered by increasing the content of the one with a high glass transition temperature. When it is desired to increase the coefficient of kinetic friction, the adjustment can be made conversely. When containing the radically polymerizable oligomer (b) and / or the radically polymerizable monomer (c) as the radically polymerizable organic compound, the coefficient of kinetic friction can be lowered by increasing the content of the one with a low viscosity. When it is desired to increase the coefficient of kinetic friction, the adjustment can be made conversely. In addition, the coefficient of kinetic friction can be lowered by increasing the content of the thermal radical polymerization initiator. When it is desired to increase the coefficient of kinetic friction, the adjustment can be made conversely.

[0021] <Radically polymerizable organic compound> A radically polymerizable organic compound contains a radically polymerizable group that is polymerized and / or crosslinked to increase its molecular weight by applying activation energy in the presence of a thermal radical polymerization initiator. The radically polymerizable organic compound is an organic compound having such a group. The radically polymerizable organic compound adjusts the shrinkage force during thermosetting and is suitable for sealing properties and low-temperature curability. The radically polymerizable group is, for example, an unsaturated double bond such as a (meth)acryloyl group, an N-vinyl group, a vinyl ether group, an allyl group, an unsaturated carboxylic acid group, etc. It is a functional group having The radically polymerizable organic compound has at least one radically polymerizable group in one molecule, preferably two or more, and more preferably a (polyfunctional) compound having three or more. This makes it easier to form a crosslinked structure of the molecule and improves the low-temperature curability. Among the radically polymerizable organic compounds, compounds having a (meth)acryloyl group are preferable because they are easy to synthesize, easy to obtain, and easy to handle. They are also preferable from the viewpoint of transparency. For example, epoxy (meth)acrylate, urethane (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, and (meth)acrylic acid esters of alcohols can be mentioned. Epoxy (meth)acrylate is, for example, an acrylate obtained by reacting a conventionally known aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, etc. with (meth)acrylic acid. Preferred urethane (meth)acrylates are those obtained by reacting a polyester or polyether containing one or more hydroxyl groups with a hydroxyl group-containing (meth)acrylic acid ester.

[0022] Among the radically polymerizable organic compounds, compounds having a (meth)acryloyl group are preferable because they are easy to synthesize, easy to obtain, and easy to handle. They are also preferable from the viewpoint of transparency. For example, epoxy (meth)acrylate, urethane (meth)acrylate, polyester (meth)acrylate, polyether (meth)acrylate, and (meth)acrylic acid esters of alcohols can be mentioned. Epoxy (meth)acrylate is, for example, an acrylate obtained by reacting a conventionally known aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, etc. with (meth)acrylic acid. Preferred urethane (meth)acrylates are those obtained by reacting a polyester or polyether containing one or more hydroxyl groups with a hydroxyl group-containing (meth)acrylic acid ester.

[0023] Epoxy (meth)acrylate is, for example, an acrylate obtained by reacting a conventionally known aromatic epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, etc. with (meth)acrylic acid. Urethane (meth)acrylate is preferably one obtained by reacting a polyester or polyether containing one or more hydroxyl groups with a hydroxyl group-containing (meth)acrylic acid ester. It is an acrylate. Preferred urethane (meth)acrylates are those obtained by reacting one or more hydroxyl group-containing polyesters or hydroxyl group-containing polyethers with a hydroxyl group-containing (meth)acrylic acid ester. (Meth)acrylates obtained by reacting socianates, or (meth)acrylates obtained by reacting hydroxyl group-containing (meth)acrylic acid esters with isocyanates, etc. and the like. .

[0024] Preferred hydroxyl group-containing polyesters are hydroxyl group-containing polyesters obtained by reacting one or more polyhydric alcohols with one or more polybasic acids. Examples of aliphatic polyhydric alcohols include 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, neopentyl glycol, polyethylene glycol, polypropylene glycol, polybutylene glycol, trimethylolpropane, glycerin, pentaerythritol, dipentaerythritol, and the like. Examples of polybasic acids include adipic acid, terephthalic acid, phthalic anhydride, trimellitic acid, and the like.

[0025] Preferred hydroxyl group-containing polyethers are hydroxyl group-containing polyethers obtained by adding one or more alkylene oxides to a polyhydric alcohol. Examples of polyhydric alcohols include the same compounds as those described above. Examples of alkylene oxides include ethylene oxide, propylene oxide, and butylene oxide.

[0026] Preferred hydroxyl group-containing (meth)acrylic acid esters are hydroxyl group-containing (meth)acrylic acid esters obtained by an esterification reaction of a polyhydric alcohol with (meth)acrylic acid. Examples of polyhydric alcohols include the same compounds as those described above.

[0027] Among such hydroxyl group-containing (meth)acrylic acids, dihydric alcohols and (meth)acrylic acids Particularly preferred is a hydroxyl group-containing (meth)acrylic acid ester obtained by the esterification reaction of Examples of suitable acrylates include 2-hydroxyethyl (meth)acrylate.

[0028] Isocyanates are compounds that have at least one isocyanate group in the molecule. Compounds such as tolylene diisocyanate, hexamethylene diisocyanate, and isopropyl alcohol are preferred. Divalent isocyanate compounds such as phoron diisocyanate are particularly preferred.

[0029] Preferred polyester (meth)acrylates are hydroxyl group-containing polyesters and It is a polyester (meth)acrylate obtained by reacting with (meth)acrylic acid. The hydroxyl group-containing polyester used herein is preferably one or more polyhydroxyl groups. By esterification reaction of hydric alcohol with one or more monobasic or polybasic acids The resulting hydroxyl group-containing polyester may contain the above-mentioned compounds as polyhydric alcohols. The same can be exemplified. Examples of monobasic acids include formic acid, acetic acid, butyric acid, and benzoic acid. Examples of polybasic acids include adipic acid, terephthalic acid, phthalic anhydride, trimellitic acid, and the like. Examples of such acids include butyl acetate and butyl acetate.

[0030] Preferred polyether (meth)acrylates are hydroxyl group-containing polyethers and and (meth)acrylic acid. The hydroxyl group-containing polyether used here is preferably a polyhydric alcohol. Or, a hydroxyl group-containing poly(alkylene oxide) obtained by adding two or more alkylene oxides. An ether, and examples of the polyhydric alcohol include the same compounds as those described above. Examples of the alkylene oxide include ethylene oxide, propylene oxide , and butylene oxide.

[0031] Preferred (meth)acrylic acid esters of alcohols are (meth)acrylates obtained by reacting an aromatic or aliphatic alcohol having at least one hydroxyl group in the molecule and its alkylene oxide adduct with (meth)acrylic acid. For example, , 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate , 2-hydroxypropyl (meth)acrylate, isoamyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, isooctyl (meth )acrylate, tetrahydrofurfuryl (meth)acrylate, isobornyl (meth)a crylate, benzyl (meth)acrylate, 1,3-butanediol di(meth)acry late, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di (meth)acrylate, diethylene glycol di(meth)acrylate, triethylene gly col di(meth)acrylate, neopentyl glycol di(meth)acrylate, po lyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)a crylate, trimethylolpropane tri(meth)acrylate, ethylene oxide-modified trimethylolpropane tri(meth)acrylate, propylene oxide-modified trimeth ylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)ac rylate, etc. Relates, dipentaerythritol hexa (meth) acrylate, ε-caprolactone modification Examples thereof include dipentaerythritol hexa (meth) acrylate modified with ε-caprolactone.

[0032] The radically polymerizable organic compound preferably contains a radically polymerizable polymer (a). Or, it preferably contains at least one of a radically polymerizable oligomer (b) and a radically polymerizable monomer (c).

[0033] <Radically polymerizable polymer (a)> The radically polymerizable polymer (a) (hereinafter also referred to as polymer (a)) is an organic compound containing the above-mentioned radically polymerizable group, and has a weight average molecular weight of 10,000 or more and 1 It represents a high molecular compound of 000,000 or less.

[0034] The glass transition temperature of the radically polymerizable organic compound is preferably -50°C or higher and 90°C or lower, more preferably -15°C or higher and 65°C or lower, and most preferably 0°C or higher and 50°C or lower. By being within this range a dry film with good sealing properties can be obtained. The glass transition temperature is measured by the method described in the following examples.

[0035] The content of the radically polymerizable organic compound is preferably 10 to 98% by mass, more preferably 40 to 95% by mass, and even more preferably 60 to 90% by mass in 100% by mass of the total solid content of the dry film. By setting the above content, the sealing property and the low-temperature curability can be suitably adjusted.

[0036] <Radically polymerizable oligomer (b)> The radically polymerizable oligomer (b) (hereinafter also referred to as oligomer (b)) is a radical ​​​​​It is a polymer having a structural unit based on 2 to 100 monomers containing a cyclic polymerizable group, which is liquid under normal temperature and pressure. Also, it is a compound with a weight average molecular weight of 100 or more and less than 10,000. The weight average molecular weight is more preferably 300 or more and 8,000 or less, even more preferably 400 or more and 6,000 or less, and most preferably 500 or more and 4,500 or less. By setting it within the above range, the fluidity of the dry film can be enhanced and the sealing property can be improved.

[0037] The content of the oligomer (b) is preferably 0.1 to 70% by mass, more preferably 1 to 50% by mass, even more preferably 10 to 50% by mass, and most preferably 30 to 50% by mass in 100% by mass of the total solid content of the dry film. By setting the above content, the sealing property, low-temperature curability, and handleability can be suitably adjusted.

[0038] <Radical polymerizable monomer (c)> The radical polymerizable monomer (c) (hereinafter also referred to as monomer (c)) means a compound having a radical polymerizable group as the minimum structural unit for constituting an oligomer or a polymer, and is liquid under normal temperature and pressure. The monomer may be a monofunctional monomer or a polyfunctional monomer. In particular, a (meth)acrylate compound can be preferably used because of its easy handling. From the viewpoint of the sealing property, it preferably contains a 2- to 6-functional (meth)acrylate monomer, and more preferably contains a 2- to 3-functional (meth)acrylate monomer.

[0039] The content of the monomer (c) is 0.01 to 7% by mass in 100% by mass of the total solid content of the dry film. ​0 mass% is preferable, more preferably 0.1 to 50 mass%, still more preferably 1 to 30 mass%, and most preferably 1 to 10 mass%. By setting the content within the above range, the sealing property and low-temperature curability can be suitably adjusted. Preferably, the radically polymerizable organic compound contains either the radically polymerizable oligomer (b) or the radically polymerizable monomer (c), and it may contain both.

[0040] When the dry film contains the oligomer (b) or the monomer (c), from the viewpoint of handleability, it preferably contains the binder resin described later for the purpose of suppressing tack. Preferably, the binder resin contains 30 mass% or more, more preferably 50 mass% or more, based on 100 mass% of the oligomer (b) or the monomer (c). By being within this range, it is possible to achieve both sealing property and low-temperature curability and obtain a dry film with good handleability.

[0041]

[0042] <Thermal radical polymerization initiator> The 10-hour half-life temperature of the thermal radical polymerization initiator is 60°C or higher and 170°C or lower, preferably 80°C or higher and 160°C or lower, and more preferably 100°C or higher and 150°C or lower. By setting the 10-hour half-life temperature of the thermal radical polymerization initiator to 60°C or higher, the storage stability of the dry film can be maintained, and good sealing property can be maintained even after long-term storage. Also, it can prevent the polymerization (curing) from proceeding rapidly during the thermal press at the time of sealing, and good sealing property can be exhibited. By setting it to 170°C or lower, the thermal curing temperature of the dry film can be lowered, and the curing time can be shortened, so that the low-temperature curability can be improved. ​​​​​​​​​​​​​

[0043] The 10-hour half-life temperature is the temperature at which the initiator concentration of the thermal radical polymerization initiator is reduced to half after 10 hours by thermal decomposition. Specifically, with respect to the radicals of the thermal radical polymerization initiator, a solution of the thermal radical polymerization initiator is prepared using an inert solvent, and it is sealed in a glass tube that has been purged with nitrogen. This is immersed in a thermostatic layer set at a predetermined temperature for 10 hours for thermal decomposition, and the amount of the remaining thermal radical polymerization initiator is measured. By performing this series of operations at several temperatures and plotting the results, the 10-hour half-life temperature can be determined from the obtained straight line. For the thermal radical polymerization initiator, an azo thermal polymerization initiator or an organic peroxide polymerization initiator can be used. From the perspective of storage stability, an azo thermal polymerization initiator is preferably used. The thermal radical polymerization initiator adjusts the shrinkage force during thermal curing, and suitable sealing properties and low-temperature curability are obtained. Examples of the organic peroxide polymerization initiator having a 10-hour half-life temperature of 60°C or higher and 170°C or lower include dialkyl peroxides such as di-t-amyl peroxide, di-t-butyl peroxide, di-t-hexyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, α,α'-bis(t-butylperoxy-m-isopropyl)benzene, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexin-3, and 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane; t-amyl peroxyacetate, t-butyl peroxyacetate, t-amyl peroxybenzoate, t-butyl peroxybenzoate, t-hexyl peroxybenzoate, t-amyl peroxy-2-ethylhexanoate, t-butyl peroxy-2- ethylhexanoate, and the like.

[0044]

[0045] ​ -ethylhexanoate, t-hexylperoxy-2-ethylhexanoate, 1,1 ,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-butylper oxy-3,5,5-trimethylhexanoate, t-butylperoxyisobutyrate , t-amylperoxyisononanoate, t-butylperoxyisononanoate, t -butylperoxylaurate, n-butyl 4,4-di-(t-butylperoxy)val erate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-di methyl-2,5-di-2-ethylhexanoylperoxyhexane and other peroxyes ters; 2,2-bis(t-butylperoxy)butane, 2,2-bis(4,4-di-t-butyl peroxycyclohexyl)propane, 1,1-bis(t-amylperoxy)cyclohe xane, 1,1-bis(t-butylperoxy)cyclohexane, 1,1-bis(t-he xylperoxy)cyclohexane, 4,4-bis(t-butylperoxy)pentanoic acid butyl and other peroxyketals; t-amyl hydroperoxide, cumene hydroperoxide, p-menthane hydro peroxide, diisopropylbenzene hydroperoxide, 1,1,3,3 -tetramethylbutyl hydroperoxide and other hydroperoxides; dibenzoyl peroxide, dinonanoyl peroxide, dilauroyl peroxyi de, succinic peroxide and other diacyl peroxides; t-butylperoxyisopropyl carbonate, t-amylperoxyisopropyl ca rbonate, t-hexylperoxyisopropyl carbonate, t-butylperoxy -2-Ethylhexyl carbonate, t-amyl peroxy-2-ethylhexyl carbonate, and other peroxy carbonates, etc. may be mentioned, but are not limited thereto. Examples include, but are not limited to, peroxy carbonates such as these. Dialkyl peroxides are preferred from the viewpoint of storage stability, and di-t-butyl peroxide is more preferred.

[0046] Regarding the azo thermal polymerization initiator having a 10-hour half-life temperature of 60°C or higher and 170°C or lower, for example, 2,2’-azobisisobutyronitrile, 2,2’-azobis(2-methylbutyronitrile), and other 2,2’-azobisbutyronitriles; 1,1’-azobis(cyclohexane-1-carbonitrile) and other 1,1’-azobis-1-alkane nitriles; 2,2’-azobis(N-butyl-2-methylpropionamide), and other 2,2’-azobispropionamides; Other examples include dimethyl 1,1’-azobis(1-cyclohexanecarboxylate), dimethyl 2,2’-azobis(2-methylpropionate), dimethyl 2,2’-azobisisobutyrate, 1,1’-azobis(acetoxy-1-phenylethane), 2,2’-azobis(2,4,4-trimethylpentane), 2,2’-azobis[2-(2-imidazolin-2-yl)propane], etc. Also, azo compounds having a carboxyl group or a hydroxyl group include, for example, 4,4’-azobis(4-cyanopentanoic acid), 2,2’-azobis(2-methyl-N-(2-hydroxyethyl)propionamide), etc., but are not limited thereto. From the viewpoint of storage stability, 2,2’-azobispropionamides are preferred, and 2,2’-azobis(N-butyl-2-methylpropionamide) is more preferred.

[0047] The thermal radical polymerization initiator is preferably contained in an amount of 0.01 to 20% by mass, more preferably 0.1 to 18% by mass, still more preferably 0.8 to 16% by mass, and most preferably 4.4 to 13% by mass in 100% by mass of the total solid content of the dry film. By setting it within the above range, transparency can be enhanced. Also, by setting it to 0.01% by mass or more, low-temperature curability and handleability can be made excellent, and by setting it to 20% by mass or less, storage stability can be made excellent.

[0048] From the viewpoint of storage stability, it is preferably not used in combination with a photo-radical polymerization initiator.

[0049] <Other components> The dry film of the present invention may contain other components as long as the object of the present invention is not impaired. For example, a colorant, a binder resin, an inorganic filler, a dispersant, etc. can be added.

[0050] <Colorant> The colorant is added when the cured product of the dry film is used as a light-shielding layer (partition wall). The colorant is preferably a black colorant (pigment, dye, etc.). Specifically, carbon black, graphite, copper oxide, manganese dioxide, aniline black, perylene black, titanium black, cyanine black, activated carbon, ferrite (non-magnetic ferrite, magnetic ferrite, etc.), magnetite, chromium oxide, iron oxide, molybdenum disulfide, chromium complex, anthraquinone-based colorant, zirconium nitride, etc. may be mentioned. Only one kind of black-based colorant may be used, or two or more kinds may be used. Also, colorants exhibiting colors other than black may be combined. A colorant that functions as a black colorant by being blended may also be used.

[0051] Among the colorants, carbon black is particularly preferable in terms of dispersibility in radical polymerizable organic compounds and light-shielding properties. As the carbon black, carbon black generally used for applications of black colorants can be used. As the carbon black, one or more known carbon blacks such as channel black, furnace black, thermal black, lamp black, and acetylene black can be used. Also, resin-coated carbon black may be used. Furthermore, carbon nanofibers or carbon nanotubes may be used. When blending carbon black into the dry film, carbon black powder may be added, or a carbon black dispersion may be added. The average particle size of carbon black is preferably 10 nm or more and 500 nm or less, more preferably 10 nm or more and 300 nm or less, and even more preferably 10 nm or more and 100 nm or less from the viewpoint of light-shielding properties. The average particle size is the arithmetic mean primary particle size determined by observing with an electron microscope. From the viewpoint of dispersibility, carbon black preferably has a specific surface area of 50 to 400 m² / g, a volatile content of 0.1 to 10% by weight, and a pH value of 2 to 10 determined by the BET method, more preferably a pH of 3 to 8, and even more preferably a pH of 3 to 6. The blending amount of the colorant is preferably 0.1 to 80% by mass, more preferably 0.5 to 40% by mass, and even more preferably 1 to 20% by mass of the total solid content of the dry film. 2

[0052] The content of the colorant is preferably 0.1 to 80% by mass of the total solid content of the dry film, more preferably 0.5 to 40% by mass, and even more preferably 1 to 20% by mass. Preferably, it is 1 to 32% by mass, and most preferably 5 to 20% by mass. With the above content a dry film with good light-shielding properties, sealing properties, and handleability can be obtained.

[0053] <Binder resin> The binder resin does not contain the above-mentioned radically polymerizable group and is an organic polymer compound different from the radically polymerizable organic compound is. Also, the binder resin is an organic polymer compound having a glass transition temperature of -50°C or higher and 90°C or lower, and a weight average molecular weight of 10,000 or more and 1,000,000 or less. The binder resin more preferably has a glass transition temperature of -15°C or higher and 50°C or lower, even more preferably 0°C or higher and 2 5°C or lower, and the weight average molecular weight is more preferably 25,000 or more and 200,00 0 or less, and even more preferably 30,000 or more and 100,000 or less. is.

[0054] As the binder resin, known and commonly used thermosetting resins and thermoplastic resins can be used . Specifically, for example, acrylic resin, maleic acid resin, polybutadiene resin, polyester resin, polyurethane resin, epoxy resin, oxetane resin, phenoxy resin, polyimide resin, polyamide resin, phenol resin, alkyd resin, amino resin, polylactic acid resin , oxazoline resin, benzoxazine resin, silicone resin, fluororesin, butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, poly vinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyester resin, vinyl resin, alkyd resin, polystyrene resin, polyamide resin, rubber resin, cyclized Rubber-based resins, celluloses, polyethylene (HDPE, LDPE), polybutadiene, ca rubodiimide resins, cyclo carbonate compounds, episulfide resins, and polyimide resins, etc. are included. In particular, acrylic resins, polyurethane resins, and epoxy resins are preferable , and acrylic resins are more preferable. By containing a binder resin, the stickiness of the dry film can be adjusted, and the handleability of the dry film can be improved.

[0055] Furthermore, when a thermosetting resin is included as the binder resin, it is preferable to contain a curing agent to promote the formation of a crosslinked structure. The curing agent has a plurality of functional groups capable of reacting with the functional groups of the thermosetting resin. The curing agent is, for example, a silane coupling agent, an epoxy crosslinking agent, an acid anhydride group-containing compound, an imidazole compound, an isocyanate compound, a blocked isocyanate compound, an aziridine compound, a known compound such as an amine compound. By containing a curing agent, the crosslinking degree of the dry film can be adjusted, and the low-temperature curability can be improved.

[0056] <Inorganic filler> The dry film can also contain an inorganic filler. By blending an inorganic filler, the curing shrinkage of the obtained cured product can be suppressed, and the thermal properties such as crack resistance can be improved. As the inorganic filler, conventionally known inorganic fillers can be used and are not limited to specific ones. For example, barium sulfate, barium titanate, amorphous silica, crystalline silica, fused silica, spherical silica, etc., silica, talc, clay, noble silica particles, mica, magnesium carbonate, calcium carbonate, titanium oxide, aluminum oxide, aluminum hydroxide Luminium, silicon nitride, aluminium nitride, calcium zirconate, and metal powders such as copper, tin, zinc, nickel, silver, palladium, aluminium, iron, cobalt, gold, platinum, etc. are mentioned. The inorganic filler is preferably spherical particles. Among them, silica is preferred, which suppresses the curing shrinkage of the cured product of the dry film and improves properties such as adhesion and hardness.

[0057] The inorganic filler may be surface-treated. As the surface treatment, surface treatment with a coupling agent or surface treatment without introducing an organic group such as alumina treatment may be performed. The surface treatment method of the inorganic filler is not particularly limited, and a known and commonly used method may be used. The surface of the inorganic filler may be treated with a surface treatment agent having a curable reaction group, for example, a coupling agent having a curable reaction group as an organic group.

[0058] <Method for forming a dry film> The method for forming a dry film is not particularly limited. As a preferred example, a liquid dry film precursor obtained by adding an arbitrary solvent to the components constituting the dry film is coated and the solvent is dried to form a dry film. The addition of the solvent is for the purpose of adjusting to a viscosity level suitable for coating. For coating, known coating machines and techniques such as comma coater, die coater, roll coater, lip coater, reverse coater, gravure coater, bar coater, curtain coater, dip coating, spin coating, silk screen, casting, etc. can be used. The solvent contained in the dry film precursor can be removed by a drying process after coating. As a preferred embodiment, the dry film precursor is coated on a support such as a release liner or a substrate. After applying it, the coating film is heated and dried using a hot air oven, an infrared heater, etc. , a dry film can be formed on one surface of the support. Further, in order to increase the crosslink density of the dry film, aging treatment such as standing under specific temperature conditions, or irradiation with UV or the like may be performed.

[0059] <Release Liner> The release liner supports the dry film and is the film on which the dry film precursor is applied when forming the dry film. As the release liner, for example, polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyimide films, polyamideimide films, polyethylene films, polytetra fluoroethylene films, polypropylene films, polystyrene films and other films made of thermoplastic resins, and paper and the like can be used. Among these, from the viewpoints of heat resistance, mechanical strength, handleability, etc., polyester films can be preferably used. The thickness of the release liner is not particularly limited, but is generally in the range of 10 to 150 μm and is appropriately selected according to the application. On the surface of the release liner where the dry film precursor is provided, a release treatment may be applied.

[0060] <Protective Film> The protective film is provided on the surface of the dry film opposite to the release liner of the dry film in order to prevent dust and the like from adhering to the surface of the dry film and to improve the handleability. Preferably. As the protective film, for example, polyester films such as polyethylene terephthalate and polyethylene naphthalate, polyimide films, polyamideimide films, poly ester films, and the like can be used. Ethylene film, polytetrafluoroethylene film, polypropylene film, polystyrene film, etc., and films made of thermoplastic resins, and paper, etc. can be used. Among these, from the viewpoints of heat resistance, mechanical strength, handleability, etc., polyester film can be preferably used. The thickness of the protective film is not particularly limited, but is generally appropriately selected according to the application in the range of 10 to 150 μm. The surface of the protective film that comes into contact with the dry film may be subjected to an antistatic treatment, an adhesion treatment, a release treatment, or an unevenness treatment. Also, in terms of the peel strength (Tl) between the release liner and the dry film and the peel strength (Th) between the protective film and the dry film, it is preferable to satisfy the relationship of Tl < Th.

[0061] <Electronic device> The cured product of the dry film is preferably provided in electronic devices such as liquid crystal displays, touch panels, notebook PCs, mobile phones, smartphones, tablet terminals, etc.

Examples

[0062] Hereinafter, the present invention will be specifically described by showing examples and comparative examples of the present invention. However, it goes without saying that the present invention is not limited to these examples. In the following, "parts" and "%" are all based on mass unless otherwise specified.

[0063] <Glass transition temperature> The glass transition temperature was determined by JIS-K7121 (DSC method: heating rate 10 °C / min). As the measurement device, a differential scanning calorimeter (DSC2500: manufactured by TA Instruments) was used.

[0064] The materials used in the examples and comparative examples are shown below.

[0065] <Radical-polymerizable organic compound> · Radical-polymerizable polymer (a)-1: To 100 parts by mass of Acrylic Acid A-814 (manufactured by DIC Corporation, acrylic polyol resin, hydroxyl value 17. 5 mgKOH / g), 15 parts by mass of a solvent (ethyl acetate) was added and stirred Then, 15 parts by mass of Karenz AOI (2-acryloyloxyethyl isocyanate, manufactured by Resona Co., Ltd.) ) was added, and the mixture was stirred at 60 °C for 24 hours to obtain radical-polymerizable polymer (a) -1. The glass transition temperature was 85 °C. · Radical-polymerizable polymer (a)-2: To 100 parts by mass of Acrylic Acid A-801P (manufactured by DIC Corporation, acrylic polyol resin, hydroxyl value 50 mgKOH / g), 15 parts by mass of a solvent (ethyl acetate) was added and stirred Then, 15 parts by mass of Karenz AOI (2-acryloyloxyethyl isocyanate, manufactured by Resona Co., Ltd.) was added, and the mixture was stirred at 60 °C for 24 hours to obtain radical-polymerizable polymer (a)- 2. The glass transition temperature was 50 °C. · Radical-polymerizable polymer (a)-3: To 100 parts by mass of Acrylic Acid 44-127 (manufactured by DIC Corporation, acrylic polyol resin, hydroxyl value 70 mgKOH / g), 15 parts by mass of a solvent (ethyl acetate) was added and stirred Then, 15 parts by mass of Karenz AOI (2-acryloyloxyethyl isocyanate, manufactured by Resona Co., Ltd.) was added, and the mixture was stirred at 60 °C for 24 hours to obtain radical-polymerizable polymer (a)- 3. The glass transition temperature was 35 °C. · Radical-polymerizable polymer (a)-4: Acrylic Acid A-811 (manufactured by DIC Corporation, acrylic polyol resin, hydroxyl value 34m To 100 parts by mass of (gKOH / g), 15 parts by mass of a solvent (ethyl acetate) was added and stirred, and then , 1 part of Karenz AOI (2-acryloyloxyethyl isocyanate, manufactured by Resonaak) 5 parts by mass was added, and the mixture was stirred at 60 °C for 24 hours to obtain a radically polymerizable polymer (a)-4 . The glass transition temperature was 20 °C. · Radically polymerizable polymer (a)-5: To 100 parts by mass of Acrylic 49-394-IM (manufactured by DIC, acrylic polyol resin, hydroxyl value 25 mgKOH / g), 15 parts by mass of a solvent (ethyl acetate) was added and stirred. After that, 15 parts by mass of Karenz AOI (2-acryloyloxyethyl isocyanate, Resonaak Co., Ltd.) was added, and the mixture was stirred at 60 °C for 24 hours to obtain a radically polymerizable polymer ( a)-5. The glass transition temperature was 15 °C. · Radically polymerizable polymer (a)-6: To 100 parts by mass of Acrylic A-817 (manufactured by DIC, acrylic polyol resin, styrene-ac rylic copolymer, hydroxyl value 60 mgKOH / g), 1 5 parts by mass of a solvent (ethyl acetate) was added and stirred. After that, Karenz AOI (2-acryloyloxyethyl isocya nate, manufactured by Resonaak Co., Ltd.) 15 parts by mass was added, and the mixture was stirred at 60 °C for 24 hours to obtain a radi cally polymerizable polymer (a)-6. The glass transition temperature was 95 °C. · Radically polymerizable oligomer (b)-1: Unidic 17-806 (manufactured by DIC), an isocyanurate triacrylate, pentaerythritol triacrylate, dipentaery thritol hexaacrylate and isophorone diisocyanate polyurethane-based ultraviolet urethane acrylate resin. Liquid under normal temperature and pressure. · Radically polymerizable monomer (c)-1: Light Acrylate DPE-6A (Kyoeisha Chemical Co., Ltd. Di-pentaerythritol hexaacrylate. Liquid under normal temperature and pressure.

[0066] <Thermal radical polymerization initiator> As the thermal radical polymerization initiator, the thermal polymerization initiators (A) to (G) described in Table 1 were used. Also, as the photoinitiator, photoinitiator (H) was used.

[0067]

Table 1

[0068] <Colorant> · Carbon black MA100 (manufactured by Mitsubishi Chemical Corporation) <Binder resin> · Acridic A-801P (manufactured by DIC Corporation, isocyanate-curing type acrylic resin, hydroxyl value is 50 mgKOH / g) Glass transition temperature: 50 °C

[0069] [Example 1] As the radical polymerizable organic compound, 20 parts by mass of carbon black MA100 (manufactured by Mitsubishi Chemical Corporation) as a colorant was mixed with 100 parts by mass of the solid content of the radical polymerizable polymer (a)-1 in a 0.45 L container, and 200 parts by mass of methyl isobutyl ketone as a solvent was added. After preliminary dispersion with a disperser, 1300 parts by mass of zirconia beads with a diameter of 1.0 mm were filled, and using a shaker (Scan-dex SK450: manufactured by Fast & Fluid Management Company), main dispersion was carried out for 1 hour. The zirconia beads were removed to obtain a black dispersion body. To the obtained black dispersion, 5 parts by mass of the thermal radical polymerization initiator (A): Vam-110 (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) and 38 parts by mass of a diluting solvent (a mixed solvent of methyl ethyl ketone and toluene) were added. and 38 parts by mass of a diluting solvent (a mixed solvent of methyl ethyl ketone and toluene) were added. and 38 parts by mass of a diluting solvent (a mixed solvent of methyl ethyl ketone and toluene) were added. While stirring with a disper, add them sequentially and stir until it becomes sufficiently uniform, and a dry film precursor (1) was obtained. was obtained. The dry film precursor (1) was coated on the release layer of a release liner (manufactured by Mitsui Chemicals Toagosei Co., Ltd., SP-PET-O3) to a thickness of 25 μm after drying, and heated and dried in a hot air oven at 80 °C to form a dry film, and a dry film having a release liner was obtained. was obtained.

[0070] [Examples 2 to 18, 28 to 43, Comparative Examples 1 and 2] As shown in Tables 2 and 3, Examples 2 to 18, 28 to 43, Comparative Examples 1 and 2 were carried out in the same manner as in Example 1 except that the radical polymerizable organic compound, radical polymerization initiator, and colorant were changed to the composition ratios shown in Tables 2 and 3. were obtained. The composition ratios in Tables 2 and 3 are described as the active ingredient ratios excluding the solvent.

[0071] [Example 19] As the radical polymerizable organic compound, radical polymerizable oligomer (b)-1: solid content 100 parts by mass, as the colorant, carbon black MA100 (manufactured by Mitsubishi Chemical Corporation): 20 parts by mass, as the solvent, methyl isobutyl ketone: 200 parts by mass were mixed in a 0.45 L container, and after preliminary dispersion with a disper, 1300 parts by mass of zirconia beads with a diameter of 1.0 mm were filled, and using a shaker (ScanDex SK450: manufactured by Fast & Fluid Management ent Co., Ltd.), a main dispersion was carried out for 1 hour, the zirconia beads were removed, and a black dispersion was obtained. was obtained. To the obtained black dispersion, 5 parts by mass of a thermal radical polymerization initiator (A): Vam-110 (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was stirred with a disper until it became sufficiently uniform, and a dry film precursor (19) was obtained. The dry film precursor (19) was coated on the release layer of a release liner (manufactured by Mitsui Chemicals Toagosei Co., Ltd., SP-PET-O3) with a thickness of 75 μm so that the thickness after drying would be 25 μm, and then heated and dried in a hot air oven at 80°C to form a dry film, thereby obtaining a dry film having a release liner. [Examples 20 to 27, 44 to 51, Comparative Examples 3 and 4] As shown in Tables 2 and 3, Examples 20 to 27, 44 to 51, Comparative Examples 3 and 4 were obtained in the same manner as Example 19 except that the radical polymerizable organic compound, radical polymerization initiator, colorant, and binder resin were changed to the composition ratios shown in Table 2. The binder resin was added after preparing the black dispersion after dispersion.

[0072] <Storage modulus at 80°C (G’80) and loss tangent (tanδ80)> The dry film with the release liner removed was prepared to have a thickness of 1 mm or more. Alternatively, it may be coated to a thickness of 1 mm, or dry films with a thickness of 1 mm or less may be laminated an arbitrary number of times and laminated as necessary to achieve a thickness of 1 mm or more. The obtained dry film was measured for the storage modulus G’ using a rheometer (manufactured by TA Instruments, DHR-2) with a measuring probe of φ8 mm under the conditions of a strain of 0.1%, a frequency of 1 Hz, and a heating rate of 3°C / min from 50°C to 120°C to obtain the storage modulus at 80°C (G’80). At the same time, the loss tangent at 80°C (tanδ80) was calculated by dividing the value of the loss modulus G’’ at 80°C measured simultaneously by G’80.

[0073] <Coefficient of kinetic friction> The dry film with the release liner removed, cut to a width of 40 mm, was measured for the coefficient of kinetic friction using a friction measuring machine (manufactured by Toyo Seiki Seisaku-sho, Ltd.). Placed on the FRICTION TESTER TR-2 manufactured by Kikai Seisakusho Co., Ltd., and the coefficient of kinetic friction was calculated according to the measurement method specified in JIS K7 125. The coefficient of kinetic friction was measured 5 times in total, and the average value was calculated and this was taken as the coefficient of kinetic friction of the dry film.

[0074] <Evaluation Items> For all evaluations, ◎: very good, 〇: good, △: practical, and evaluations that did not meet the target performance were marked as ×. <Optical Density> For the obtained dry film, the optical density was measured. The optical density was determined using an optical densitometer (3 61T desktop transmission densitometer: manufactured by X-RITE). The evaluation criteria were as follows Note that this evaluation was only performed on the examples and comparative examples containing colorants. ◎: Optical density is 3 or more 〇: Optical density is 1 or more and less than 3 ×: Optical density is less than 1

[0075] <Transparency> The dry film with the release liner removed was cut into a size of 2.5 cm × 10 cm, and a glass plate (blue plate glass, manufactured by Kawamura Hisakura Shoten Co., Ltd.) with a thickness of 1.1 mm was attached and crimped. For the obtained test piece, using an ultraviolet fade meter U48 (manufactured by Suga Test Instruments Co., Ltd.) a lightfastness test was performed for 48 hours using a carbon arc clamp. Next, the test piece was subjected to haze measurement of the dry film and total light transmittance using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., NDH8000). Note that this evaluation was only performed on the examples and comparative examples without colorants with respect to. ◎: Haze is 1% or less and total light transmittance is 97% or more 〇: Haze is 1% or more, or total light transmittance is 97% or less ×: Haze is 1% or more and total light transmittance is 97% or less

[0076] ​ <Sealing property> A test substrate (size: 25 mm × 25 mm glass plate) with concavities and convexities imitating those of the substrate with semiconductor elements shown in FIG. 3 was prepared, where the width of the concave part was 200 μm, the height of the convex part was 5 μm, and the width of the convex part was 200 μm formed on one surface of the plate). The dry film was cut into a size of 30 mm × 30 mm, and the exposed dry film surface with the release liner attached was placed on the concavities and convexities of the glass substrate. Then, on the release liner surface as cushion materials, a 50-μm-thick TPX (Opulan X-44B, manufactured by Mitsui Chemicals Tohseizo Co., Ltd.) and a 2.0-mm-thick vinyl chloride film (Celeb T, manufactured by Okamoto Corporation) were laminated in sequence and further laminated with cardboard for preventing sticking. Next, from above the test piece, it was pressed against the substrate surface under the conditions of 5 MPa and 100 °C for 20 minutes to fill the dry film into the concavities and convexities of the substrate and form a dry film. After pressing, the carrier film, cushion materials, and cardboard were peeled off. The dry film protruding from the substrate of the obtained test piece was removed, and the side surface of the substrate was exposed to make the concavities and convexities observable. For any 20 concave parts of the substrate the sealing property was evaluated by observing with an electron microscope. The case where the dry film was in close contact with the concave part of the substrate without gaps was regarded as the groove being filled. The evaluation criteria were as follows ◎: 18 or more filled grooves 〇: 17 or less and 15 or more filled grooves △: 14 or less and 12 or more filled grooves ×: 11 or less filled grooves as follows ◎: 18 or more embedded grooves 〇: 17 or less and 15 or more embedded grooves △: 14 or less and 12 or more embedded grooves ×: 11 or less embedded grooves

[0077] <Low-temperature curability> Regarding the obtained dry film, as a protective film on the exposed dry film surface A film with a thickness of 38 μm (manufactured by Mitsui Chemicals Toagosei Co., Ltd., SP-PET-O1) was laminated. . Then, it was heat-cured at 150 °C for 2 hours. Here, for those containing a photoinitiator, using a UV irradiation device (a high-pressure mercury UV lamp manufactured by Eye Graphics Co., Ltd.), with an output density of 1 20 W / cm and an integrated light quantity of 500 mJ / cm 2 , it was irradiated with ultraviolet light to be cured. The cured dry film had its protective film and release liner peeled off, and a test piece with a width of 30 mm and a length of 100 mm was prepared. The weight of the test piece was measured, and it was attached to a wire mesh made of 300-mesh stainless steel. The wire mesh was folded so that the test piece would not fall off, and the test piece was wrapped and immersed in methyl ethyl ketone as an extraction liquid, and left standing at 40 °C for 24 hours. After immersion , the wire mesh was taken out, washed with a small amount of methyl ethyl ketone, and dried at 100 °C for 30 minutes . Then, the weight was measured. The gel fraction was calculated by the following formula. (Gel fraction) = {(W2 - W0) / (W1 - W0)} × 100 W0: Weight of the wire mesh W1: Weight of the wire mesh + test piece W2: Weight of the wire mesh + test piece after drying The evaluation criteria were as follows. 〇: Gel fraction is 70% or more △: Gel fraction is 40% or more and less than 70% ×: Gel fraction is less than 40%

[0078] <Storage stability of dry film> A heat-accelerated test was conducted on the obtained dry film, and the sealing property was evaluated in the same way as that of the dry film before the heat-accelerated test. The evaluation criteria were as follows. ◎: In the evaluation of the sealing property after heat acceleration at 40 °C for 1 hour, the number of embedded grooves is 17 or more places 〇: In the sealing property evaluation after 1-hour heating promotion at 40°C, there are 16 embedded grooves 14 or more below △: In the sealing property evaluation after 1-hour heating promotion at 40°C, there are 13 embedded grooves 12 or more below ×: In the sealing property evaluation after 1-hour heating promotion at 30°C, there are 11 embedded grooves below

[0079] <Handling properties of dry film> The presence or absence of stickiness on the surface of the obtained dry film was evaluated by finger touch. 〇: Those without stickiness △: Those with slight stickiness ×: Those with stickiness

[0080] The evaluation results are shown in Tables 2 and 3.

[0081]

Table 2

Table 3

[0082] As shown in Comparative Example 1, when the 10-hour half-life temperature is less than 60°C, the heat press during sealing or the polymerization (curing) reaction proceeds rapidly at the start of the heating promotion test, resulting in the sealing property and the storage stability of the dry film falling short of the target performance. As shown in Comparative Example 2, when the 10-hour half-life temperature is higher than 1 70°C, the start of the curing reaction is delayed, and the low-temperature curability of the dry film fails to meet the target performance was achieved. As shown in Comparative Example 3, when only a photopolymerization initiator is used, the surface irradiated with ultraviolet light cures, but the curing does not proceed to the inside of the dry film, so the low-temperature curability fails to meet the target performance was achieved. As shown in Comparative Example 4, when the colorant is not included, the optical density fails to meet the target performance and when only a photoinitiator is used, the transparency fails to reach the target performance due to yellowing derived from the photoinitiator. Also, as shown in Comparative Examples 3 and 4, when only a photoinitiator is used, the handleability fails to reach the target performance. On the other hand, according to Examples 1 to 51, the dry film of the present invention, as shown in Tables 2 and 3, has a high level of optical density, transparency, sealing property, low-temperature curability, storage stability, and handleability in a well-balanced manner. Therefore, it is possible to provide a dry film, a cured product, and an electronic component that are excellent in optical characteristics, sealing property of a semiconductor element, low-temperature curability, storage stability and handleability.

Description of Reference Numerals

[0083] 11: Dry film 12: Release liner 13: Protective film 20: Light-emitting element 21: Substrate 22: Test substrate​​

Claims

1. A dry film containing a radically polymerizable organic compound and a thermal radical polymerization initiator, wherein 、 the 10-hour half-life temperature of the thermal radical polymerization initiator is 60°C or higher and 170°C or lower. Dry film.

2. The dry film according to Claim 1, wherein the radically polymerizable organic compound contains a radically polymerizable polymer (a) having a glass transition temperature of -50°C or higher and 90°C or lower.

3. The dry film according to Claim 1, wherein the radically polymerizable organic compound contains at least one of a radically polymerizable oligomer (b) and a radically polymerizable monomer (c) that is liquid under normal temperature and pressure. Dry film.

4. The storage modulus (G'80) at 80 °C obtained by dynamic viscoelasticity measurement is 5 × 10 ４ Pa to 5 × 10 ７ The dry film according to claim 2 or 3, characterized in that it is Pa.

5. The dry film according to Claim 4, wherein the loss tangent (tanδ80) at 80°C obtained by dynamic viscoelasticity measurement is 0.3 to 0.

7.

6. The dry film according to Claim 5, wherein the coefficient of dynamic friction on the surface of the dry film is 0.5 or less. 。

7. The dry film according to Claim 6, which contains 0.1 to 80% by mass of a colorant in 100% by mass of the total solid content of the dry film.

8. An electronic device comprising a cured product of the dry film according to Claim 7.

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