JP7108505B2 - Machinability-enhancing film, laminate, and method of using machinability-enhancing film - Google Patents

Description

TECHNICAL FIELD The present invention relates to a machinability-improving film, a laminate (a resin plate to which a machinability-improving film is attached), and a method of using the machinability-improving film.
In particular, the present invention relates to a machinability-improving film and laminate excellent in machinability, durability, and the like, and a method of using such a machinability-improving film, which are used when manufacturing touch panels, liquid crystal display devices, and the like.

Conventionally, there has been proposed a touch panel aimed at suppressing the generation of interference fringes due to light interference and enabling easy replacement of decorative films (see, for example, Patent Document 1).
More specifically, the touch panel has an operation area for receiving touch input and a non-operation area for not receiving touch input, and unevenness is formed on the lower surface of the decorative film corresponding to the operation area. It is a touch panel device characterized by the following.

Further, in a touch panel, a liquid crystal display device, etc., a pressure-sensitive adhesive sheet suitable for bonding a pair of uneven optical members has been proposed (see, for example, Patent Document 2).
More specifically, a base polymer (A), a monomer (B) having at least one polymerizable unsaturated group, a thermal cross-linking agent (C), a polymerization initiator (D), and a solvent (E ), and a pressure-sensitive adhesive layer (X) comprising a pressure-sensitive adhesive layer (X) obtained by semi-curing a pressure-sensitive adhesive composition containing and by heating.

Furthermore, an optical member has been proposed in which the adhesive is less likely to protrude during the punching process, less adhesion of the adhesive to the cut surface, and less likely to cause glue contamination or glue chipping during handling (see, for example, Patent Document 3). .
More specifically, it is an optical member in which the area of the adhesive that adheres to the portion other than the adhesive on the cut surface when punched is set to 20% or less of the area of the adhesive layer.

Japanese Patent Application Laid-Open No. 2018-5698 (Claims etc.) WO2013-61938 (Claims etc.) Japanese Patent Application Laid-Open No. 2001-235626 (Claims, etc.)

However, the touch panel device disclosed in Patent Document 1 includes a predetermined exterior unit (metal sheet/adhesive layer/decorative film), and in such an exterior unit, the metal sheet and the adhesive layer are each processed into a predetermined shape. After that, it is laminated and manufactured. For this reason, it is difficult to obtain the exterior unit in that there are many manufacturing processes.
In addition, since the adhesive layer is designed so that the decorative film can be easily replaced, and no consideration is given to the adhesive strength, durability conditions (e.g., 85 ° C., 85% RH, 500 hours, etc.) ), there was also a problem that the adhesive layer was peeled off from the decorative film due to floating or peeling at the adhesive interface, resulting in poor durability.

In addition, the adhesive sheet disclosed in Patent Document 2 is intended only for bonding a pair of optical members having unevenness, and the adhesive sheet is sandwiched between the optical members and cut into a predetermined shape. Up until now, I hadn't considered anything.
Therefore, since the value of the storage elastic modulus of the pressure-sensitive adhesive layer is not considered at all, there is also the problem of poor machinability of the pressure-sensitive adhesive sheet.

Furthermore, in the optical member disclosed in Patent Document 3, specifically, when punched, the area of the adhesive that adheres to the portion other than the adhesive on the cut surface is 20% of the area of the adhesive layer. The following control method was not described, and there was a problem of poor practicality.

Therefore, the inventors of the present invention have made diligent efforts in view of the above circumstances, and have found a machine equipped with an active energy ray-curable machinability improving layer laminated on a predetermined base material, which is attached to a resin plate. By setting the storage elastic modulus (M2) of the machinability-improving layer of the workability-improving film after irradiation with active energy rays to a predetermined value or more, a predetermined substrate containing a resin plate is cut using a cutting device or the like. Even when the functional film, which is one of the materials, and the machinability improvement layer are cut, the occurrence of chipping and elongation of the machinability improvement layer is suppressed during cutting, and the cut surface after processing is It was found that excellent machinability (cuttability) was obtained.
Furthermore, by setting the adhesive strength (P2) of the machinability-improving layer after irradiation with active energy rays to a predetermined value or more, a functional film or the like, which is one of the predetermined base materials, and a machine Even when the workability improving layer is subjected to severe durability conditions (e.g., 85°C, 85% RH, 500 hours of wet heat environment conditions), the occurrence of lifting and peeling is suppressed, and excellent durability is exhibited. I also found that
That is, the present inventors have found that it is possible to solve not only the problem of machinability but also the problem of durability, and have completed the present invention.
Therefore, the present invention provides excellent machinability (cuttability) and durability conditions when simultaneously machining (cutting) a predetermined base material together with a resin plate such as a touch panel or a liquid crystal display device. A machinability-improving film that can obtain excellent durability when used, a laminate obtained by attaching such a machinability-improving film to a resin plate, and an efficient method of using such a machinability-improving film. intended to provide

According to the present invention, a machinability-improving film having an active energy ray-curable machinability-improving layer laminated on a predetermined base material to be attached to a resin plate is attached to the resin plate. The storage modulus (M2) after irradiation with an active energy ray is 0.2 MPa or more, and the adhesive strength (P2) after irradiation with an active energy ray is 10 N/25 mm or more for the machinability-improving layer in the state. A machinability-enhancing film is provided, which can solve the above-mentioned problems.
That is, the storage elastic modulus (M2) of the machinability-improving layer after the active energy ray irradiation in the state where the machinability-improving film is configured in this way and attached to the resin plate is set to a predetermined value or more, so that the resin Even when the machinability-improving film is cut at the same time while the plate is included, chipping and elongation of the machinability-improving layer are suppressed during cutting, and the cut surface after processing is improved. Excellent machinability can be obtained.
In addition, by setting the adhesive strength (P2) of the machinability-improving layer after irradiation with active energy rays to a predetermined value or more, a durability test (for example, 85° C., 85% RH, 500 hours, etc.), no air bubbles or floating peeling occurs, and excellent durability can be exhibited.

Moreover, in constructing the machinability-improved film of the present invention, it is preferable that a functional film or a release film is included as a predetermined base material.
By including the functional film or the release film in this way, the handling of the film for improving machinability is improved, and the lamination property with the resin plate is improved.
As a result, it is possible to suppress the occurrence of defective appearance of the laminate due to a lamination error, and to prevent deterioration in durability caused by air entrainment at the lamination interface.
In addition, it is more preferable to include both the functional film and the release film as the predetermined base material.

In forming the machinability-improving film of the present invention, the gel fraction (G2) of the machinability-improving layer after irradiation with active energy rays is preferably 60% or more.
By controlling the gel fraction (G2) of the machinability-enhancing layer in this manner, even better machinability and the like can be obtained.
In addition, the cohesion of the machinability-improving layer becomes moderate after irradiation with active energy rays, which contributes to the improvement of durability.

In forming the machinability-improving film of the present invention, it is preferable that the storage modulus (M1) of the machinability-improving layer before irradiation with active energy rays is set to a value within the range of 0.01 to 1 MPa. .
By controlling the storage elastic modulus (M1) of the machinability-improving layer before irradiation with active energy rays in this way, the lamination property with the resin plate becomes excellent, and air is absorbed during lamination. It is possible to prevent deterioration of durability caused by putting away.

In forming the machinability-improving film of the present invention, it is preferable that the storage modulus (M2) of the machinability-improving layer after irradiation with active energy rays is a value within the range of 0.2 to 3 MPa. .
By controlling the storage elastic modulus (M2) of the machinability-improving layer after irradiation with active energy rays in this way, the machinability-improving layer has an appropriate cohesive force and exhibits good machinability. In addition to this, it becomes easier to achieve both durability.

In forming the machinability-improving film of the present invention, M1 is the storage elastic modulus of the machinability-improving layer before irradiation with active energy rays, and the storage elastic modulus of the machinability-improving layer after irradiation with active energy rays is is M2, the numerical value represented by M2/M1×100 (rate of increase in storage elastic modulus) is preferably in the range of 320 to 30000%.
By controlling the increase rate (%) of the storage elastic modulus to a value within a predetermined range in this way, the machinability-improving layer achieves both good bonding properties before curing and appropriate cohesive strength after curing. It becomes easy to cut, and it is possible to obtain better machinability and durability.
In addition, if it is laminated well before curing, the adhesion to the laminated interface after curing increases, so this effect is combined with the tendency to easily suppress chipping and elongation of the machinability improving layer during cutting processing. be.

In forming the machinability-improving film of the present invention, the thickness of the machinability-improving layer is preferably in the range of 3 to 40 μm.
By controlling the thickness of the machinability-improving layer of the machinability-improving film in this way, the 180° peel adhesive force ( Hereinafter, it may be simply referred to as adhesive strength.) can be easily adjusted to a value within a desired range, and good durability can be exhibited.
Moreover, since the thickness is relatively small, it can contribute to the weight reduction of the obtained laminate.

Another aspect of the present invention is a laminate comprising any one of the machinability-improving films described above attached to a resin plate.
With such a laminate, the resin plate has better workability than conventional metal frames, etc., so various functional films used in various devices are attached to the resin plate via a machinability improving layer. Cutting can be performed with high precision in a combined state.
In addition, since the resin plate is lighter than a conventional metal frame or the like, it is possible to reduce the weight of equipment to which the laminate is applied.

Moreover, in forming the laminate of the present invention, the resin plate is preferably an optical resin plate.
A laminate containing such an optical resin plate can be easily applied to equipment in the optical field. For example, in optical parts such as touch panels and liquid crystal display devices, it is possible to reduce the weight while maintaining optical characteristics. Become.

Further, still another aspect of the present invention is a method of using any one of the machinability-improving films described above, wherein the machinability-improving film comprises the following steps (1) to (4): How to use.
(1) A machine provided with an active energy ray-curable machinability-enhancing layer by applying a composition containing an active energy ray-curable component to the surface of a functional film as a predetermined substrate and heat-treating it. Step (2) Affixing the resulting machinability-improved film to a resin plate (3) Irradiating active energy rays from the resin plate or a predetermined substrate side to form a machinability-improving layer Step (4): Curing the active energy ray-curable component to form a cured machinability-improving layer; By using the machinability-improving film in this way, it is possible to easily manufacture a resin plate with a functional film through the machinability-improving layer, which can be applied to optical parts such as touch panels and liquid crystal display devices. can do. That is, a laminate having a desired shape can be easily obtained by one cutting process. Furthermore, since the machinability-enhancing layer does not chip or stretch during the cutting process, the machined surface after machining is good, and the resulting laminate has excellent appearance quality. Furthermore, since the obtained laminate is excellent in durability, it can also be applied to optical parts used in harsh environments (for example, touch panels for vehicles, liquid crystal display devices, etc.).

FIGS. 1(a) and 1(b) are diagrams provided for explaining configuration examples of laminates each using a machinability-enhancing film. FIG. 2 is a diagram for explaining the relationship between the storage elastic modulus (MPa) and the machinability (relative value) of the machinability-improving layer after irradiation with active energy rays. FIGS. 3A to 3E are diagrams provided for explaining a method for manufacturing a machinability-improved film including a thermal crosslinking step, and a method for manufacturing a laminate using the machinability-improved film. . FIGS. 4(a) to 4(f) are diagrams provided for explaining the steps of creating and using a laminate using a functional film as a predetermined base material and a film for improving machinability (the 1). 5(a) to 5(f) are diagrams provided for explaining the steps of producing and using another laminate using a release film as a predetermined base material and using a machinability-enhancing film. (Part 2).

As illustrated in FIGS. 1(a) and 1(b), the embodiment of the present invention includes an active energy ray-curable machinability improving layer 14 attached to a resin plate 12, and a predetermined base material 16 ( functional film, etc.), a laminate 10 using such a machinability-improving film 18, and a method of using the machinability-improving film 18.
In the machinability-improving film 18 of the present embodiment, the machinability-improving layer 14 laminated on the resin plate 12 has a storage elastic modulus (M2) of 0.2 MPa or more after irradiation with active energy rays. It is characterized by having an adhesive strength (P2) of 10 N/25 mm or more after irradiation with an active energy ray.
Hereinafter, the machinability improving film 18 will be specifically described for each component with reference to the drawings as appropriate.
Note that FIG. 1(a) illustrates a mode of a laminate 10 composed of a resin plate 12 laminated with a machinability improving film 18, and FIG. 1(b) shows another laminate. 10, showing an example of a touch panel having a predetermined space 14a in a part of the machinability improving layer 14 (however, electric wiring etc. are omitted).

1. Resin Plate (1) Type The type of the resin plate 12 shown in FIG. It is preferable to use

Examples of such resin plates include polyester resin plates such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene resin plates, polypropylene resin plates, diacetylcellulose resin plates, triacetylcellulose resin plates, and acetylcellulose butyrate resin plates. , polyvinyl chloride resin plate, polyvinylidene chloride resin plate, polyvinyl alcohol resin plate, ethylene-vinyl acetate copolymer resin plate, polystyrene resin plate, polycarbonate resin plate, polymethylpentene resin plate, polysulfone resin plate, polyether ether ketone Resin plates, polyethersulfone resin plates, polyetherimide resin plates, polyimide resin plates, fluororesin plates, polyamide resin plates, acrylic resin plates, norbornene resin plates, cycloolefin resin plates, and the like.

Among these, polyester resin plate, polycarbonate resin plate, polymethylpentene resin plate, polysulfone resin plate, acrylic resin plate, and polyether resin plate have excellent optical properties and heat resistance and are excellent in dimensional stability. At least one of an ether ketone resin plate, a polyimide resin plate, a norbornene resin plate, and a cycloolefin resin plate is preferable.
In addition, acrylic resin plates (MMA resin plates, etc.) and polycarbonate resin plates are particularly preferred because they are excellent in transparency, mechanical strength, flexibility, workability, weather resistance, and economic efficiency. More preferred.

(2) Thickness It is preferable that the thickness of the resin plate 12 shown in FIG.
The reason for this is that if the thickness of the resin plate is less than 200 μm, the strength of the resin plate may decrease, and the arrangement fixability of the touch panel including the resin plate may decrease.
On the other hand, if the thickness of the resin plate exceeds 10,000 μm, it may be difficult to simultaneously machine the resin plate and the functional film or the like as the predetermined base material through the machinability improving layer. This is because
Therefore, it is more preferable to set the thickness of the resin plate to a value within the range of 500 to 5000 μm, more preferably to a value within the range of 700 to 2000 μm.

(3) Optical properties Regarding the optical properties of the resin plate, it is preferable that the resin plate has transparency to the extent that it can be used for applications such as touch panels and liquid crystal display devices.
Specifically, if the visible light transmittance of the resin plate is excessively low, the yield may be remarkably reduced, or the types of usable constituent materials may be excessively limited.
Therefore, the lower limit of the visible light transmittance of the resin plate is preferably 60% or more, more preferably 75% or more, and even more preferably 85% or more.
On the other hand, the upper limit of the visible light transmittance of the resin plate is usually 100% or less, preferably 99.9% or less, more preferably 99% or less, and 98% or less. It is more preferable to set it as a value.

(4) Additives Anti-oxidants, anti-hydrolysis agents, UV absorbers, inorganic fillers, organic fillers, inorganic fibers, organic fibers, conductive additives are used to improve the durability, physical properties, mechanical properties, etc. of resin boards. It is also preferable to add at least one known additive from materials, electrically insulating materials, metal ion scavengers, lightening agents, fillers, abrasives, colorants, viscosity modifiers, and the like.
When these known additives are blended into the resin board, the blending amount is usually 0.00% with respect to the total amount (100% by weight) of the resin board, although it depends on the type of the additive. A value in the range of 1 to 30% by weight is preferable, a value in the range of 0.5 to 20% by weight is more preferable, and a value in the range of 1 to 10% by weight is further preferable. preferable.

2. Machinability-improving layer The machinability-improving layer 14 in the present embodiment includes a (meth)acrylic acid ester copolymer as a main agent (A), a thermosetting component (B), and an active energy ray-curable component ( It can be obtained by thermally cross-linking the resin layer 13 derived from the composition for forming the machinability-improving layer, which contains C) as an essential component, by heat treatment.
That is, the machinability improving layer 14 has a crosslinked structure composed of a (meth)acrylic acid ester copolymer as a main agent (A) and a thermosetting component (B), and an uncured active energy ray It is composed of a curable component (C). By curing the machinability-improving layer 14 by irradiating it with active energy rays, a cured machinability-improving layer 14' can be obtained.

In this specification, "(meth)acrylate" means both acrylate and methacrylate, and the same applies hereinafter, including other similar terms.
Hereinafter, each component and the like constituting the machinability improving layer 14 will be specifically described.

(1) Main agent (A)
The type of the main agent (A) that constitutes the machinability-enhancing layer 14 is not particularly limited.
However, for example, since it is easily available and easily mixed with the active energy ray-curable component (C) described later, a (meth)acrylic acid ester copolymer derived from a predetermined (meth)acrylic acid ester monomer component is preferably the main agent (A).

When the main agent is a (meth)acrylic acid ester copolymer, a monomer having a reactive group in the molecule that reacts with the thermosetting component (B) (reactive It preferably contains a functional group-containing monomer) and a (meth)acrylic acid alkyl ester.
The reason for this is that the reactive group derived from the reactive group-containing monomer reacts with the thermosetting component (B) to form a crosslinked structure (three-dimensional network structure), resulting in a relatively high mechanical processing film strength. This is because a property-improving layer can be obtained.

(1)-1 Monomer 1 (reactive functional group-containing monomer)
Examples of reactive group-containing monomers constituting a part of the (meth)acrylic acid ester polymer as the main agent (A) include monomers having a hydroxyl group in the molecule (hereinafter sometimes referred to as hydroxyl group-containing monomers), molecules A monomer having a carboxy group in the molecule (hereinafter sometimes referred to as a carboxy group-containing monomer), a monomer having an amino group in the molecule (hereinafter sometimes referred to as an amino group-containing monomer), and the like.
Among these, a hydroxyl group-containing monomer is preferable from the viewpoint of excellent reactivity with the thermosetting component (B) and less adverse effect on the adherend, and the weight average molecular weight of the (meth) acrylic acid ester copolymer is Carboxy group-containing monomers are preferred from the viewpoint of exhibiting the desired cohesive strength, even if they are relatively low.

Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and hydroxyalkyl (meth)acrylates such as 3-hydroxybutyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate.
Among these, from the viewpoint of the reactivity between the hydroxyl group and the thermosetting component (B) in the obtained (meth)acrylic acid ester copolymer and the copolymerizability with other monomers, (meth)acrylic acid 2 -hydroxyethyl and 4-hydroxybutyl (meth)acrylate are preferred, and 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate are more preferred. These may be used alone or in combination of two or more.

In addition, the amount of the hydroxyl group-containing monomer as a monomer unit is preferably 1% by weight or more, preferably 10% by weight or more, relative to the total amount of monomers (100% by weight, hereinafter the same). is more preferable, and it is even more preferable to contain 15% by weight or more.
Furthermore, the amount of the hydroxyl group-containing monomer compounded is preferably 50% by weight or less, more preferably 40% by weight or less, and even more preferably 30% by weight or less, based on the total amount of the monomers.
That is, when the (meth)acrylic acid ester copolymer contains a hydroxyl group-containing monomer in a predetermined range as a monomer unit, it becomes easier to react appropriately with the thermosetting component (B), and a good crosslinked structure is formed. be. As a result, the resulting machinability-improving layer has a relatively high film strength, the storage elastic modulus of the machinability-improving layer easily satisfies a desired value, and has good machinability.

Carboxy group-containing monomers include, for example, ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, and citraconic acid.
Among these, acrylic acid is preferable from the viewpoint of the reactivity between the carboxy groups in the resulting (meth)acrylic acid ester copolymer and the thermosetting component (B) and the copolymerizability with other monomers. These may be used alone or in combination of two or more.
Then, when a carboxy group-containing monomer is included as a monomer unit, the (meth)acrylic acid ester copolymer preferably contains 1% by weight or more of the carboxy group-containing monomer with respect to the total amount of the monomers. It is particularly preferable to contain 8% by weight or more, and more preferably 8% by weight or more.
Furthermore, the (meth)acrylic acid ester copolymer preferably contains 30% by weight or less, more preferably 20% by weight or less, of a carboxy group-containing monomer as a monomer unit constituting the polymer. It is more preferable to contain 15% by weight or less.
That is, by containing a carboxy group-containing monomer as a monomer unit in a predetermined range, it becomes easier to react favorably with the thermosetting component (B), and a good crosslinked structure is formed.
As a result, the resulting machinability-improving layer has a relatively high film strength, the storage elastic modulus of the machinability-improving layer easily satisfies a desired value, and the machinability-improving layer has good machinability.

It is also preferable that the monomer units contain a small amount of a carboxy group-containing monomer or do not contain any at all.
The reason for this is that the carboxyl group is an acid component, and by not containing a carboxyl group-containing monomer, the adhesive may cause problems due to the acid, such as a transparent conductive film such as tin-doped indium oxide (ITO). This is because even if there is a metal film or the like, it is possible to suppress the problems (corrosion, resistance value change, etc.) caused by the acid.
However, it is permissible to contain a predetermined amount of the carboxy group-containing monomer to the extent that such problems do not occur.
Specifically, in the (meth)acrylic acid ester copolymer, as a monomer unit, a carboxy group-containing monomer is 5% by weight or less, preferably 1% by weight or less, more preferably 0.1% by weight or less. Allowed to contain.

Examples of amino group-containing monomers include aminoethyl (meth)acrylate and n-butylaminoethyl (meth)acrylate.
These may be used alone or in combination of two or more.

(1)-2 Monomer 2 ((meth)acrylic acid alkyl ester monomer)
The (meth)acrylic acid ester copolymer as the main agent (A) may contain a (meth)acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms as a monomer unit constituting the copolymer. preferable.
This allows the machinability-improving layer to exhibit preferable adhesiveness.
In addition, the (meth)acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms preferably has a linear or branched structure from the viewpoint of exhibiting more preferable adhesiveness.

The (meth)acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms preferably has a glass transition temperature (Tg) of less than 0° C. as a homopolymer (hereinafter sometimes referred to as a low Tg alkyl acrylate). be.).
The reason for this is that by containing such a low Tg alkyl acrylate as a constituent monomer unit, the adhesiveness of the obtained machinability-improving layer can be further improved.

Examples of low Tg alkyl acrylates include n-butyl acrylate (Tg: -55°C), n-octyl acrylate (Tg: -65°C), isooctyl acrylate (Tg: -58°C), acrylic 2-ethylhexyl acid (Tg: -70°C), isononyl acrylate (Tg: -58°C), isodecyl acrylate (Tg: -60°C), isodecyl methacrylate (Tg: -41°C), n-lauryl methacrylate (Tg: -65°C), tridecyl acrylate (Tg: -55°C), tridecyl methacrylate (Tg: -40°C) and the like are preferably mentioned.
Among these, from the viewpoint of more effectively improving adhesiveness, as the low Tg alkyl acrylate, those having a homopolymer Tg of −25° C. or less are more preferable, and those having −50° C. or less are even more preferable.
Specifically, n-butyl acrylate and 2-ethylhexyl acrylate are particularly preferred.

In addition, the (meth)acrylic acid ester copolymer preferably contains a low Tg alkyl acrylate as a monomer unit constituting the polymer in an amount of 30% by weight or more as a lower limit, particularly 40% by weight or more. is more preferable, and it is even more preferable to contain 50% by weight or more.
The reason for this is that when such a low-Tg alkyl acrylate is blended, the resulting machinability-improving layer can have a good improvement in adhesiveness and can be more excellently attached to a resin plate. is.
Further, the (meth)acrylic acid ester copolymer preferably contains 99% by weight or less, particularly 90% by weight or less, of a low-Tg alkyl acrylate as a monomer unit constituting the polymer. is more preferable, and it is even more preferable to contain 80% by weight or less.
The reason for this is that by blending such a low Tg alkyl acrylate, it is possible to introduce a suitable amount of other monomer components (especially reactive functional group-containing monomers) into the (meth)acrylic acid ester polymer. be.

In addition, the (meth)acrylic acid ester polymer may be used in combination with a monomer having a glass transition temperature (Tg) exceeding 0 ° C. as a homopolymer (hereinafter sometimes referred to as a high Tg alkyl acrylate). is also preferred.
The reason for this is that the obtained machinability-improving layer is imparted with an appropriate cohesive force, the storage elastic modulus of the machinability-improving layer easily satisfies a desired value, and machinability can be improved.

However, the high Tg alkyl acrylate described here excludes alicyclic structure-containing monomers and nitrogen-containing monomers, which will be described later.
Examples of such high Tg alkyl acrylates include methyl acrylate (Tg: 10°C), methyl methacrylate (Tg: 105°C), ethyl methacrylate (Tg: 65°C), n-butyl methacrylate (Tg: 20°C), isobutyl methacrylate (Tg: 48°C), t-butyl methacrylate (Tg: 107°C), n-stearyl acrylate (Tg: 30°C), n-stearyl methacrylate (Tg: 38°C), etc. acrylic monomer, vinyl acetate (Tg: 32°C), styrene (Tg: 30°C), and the like.
Among these, methyl methacrylate is particularly preferable as the high Tg alkyl acrylate because it can impart an appropriate cohesive force to the machinability-improving layer and can exhibit a desired storage elastic modulus.

That is, when the (meth)acrylic acid ester polymer contains the high Tg alkyl acrylate as a monomer unit constituting the polymer, the high Tg alkyl acrylate is added to 1% by weight with respect to the total amount of the monomer components. It is more preferable to contain at least 3% by weight, more preferably at least 3% by weight.
In addition, the (meth)acrylic acid ester polymer preferably contains 20% by weight or less, more preferably 12% by weight or less, of the high Tg alkyl acrylate as a monomer unit constituting the polymer. It is more preferable to contain not more than weight %.
The reason for this is that by using the high Tg alkyl acrylate together with the low Tg alkyl acrylate in the above amount, the resulting machinability-improving layer exhibits suitable adhesiveness and cohesion. This is because the desired values of storage elastic modulus and storage elastic modulus are easily satisfied, and machinability and durability are easily exhibited.

(1)-3 Monomer 3 (alicyclic structure-containing monomer)
The (meth)acrylic acid ester copolymer as the main agent (A) contains a monomer having an alicyclic structure in the molecule (alicyclic structure-containing monomer) as a monomer unit constituting the copolymer. is preferred.
The reason for this is that the alicyclic structure-containing monomer is bulky in terms of molecular structure, and it is presumed that the presence of this in the copolymer widens the distance between the polymers. As a result, the resulting machinability-improving layer can have excellent flexibility.
Therefore, when the (meth)acrylic acid ester polymer contains an alicyclic structure-containing monomer as a monomer unit, the machinability-improving layer obtained by cross-linking the composition has excellent bonding properties to the resin plate. It becomes a thing.

In addition, the carbon ring of the alicyclic structure in the alicyclic structure-containing monomer may have a saturated structure or may partially have an unsaturated bond.
Moreover, such an alicyclic structure may be a monocyclic alicyclic structure, or may be a polycyclic alicyclic structure such as bicyclic or tricyclic.
In the obtained (meth)acrylic acid ester copolymer, from the viewpoint of widening the distance between the polymers and effectively exhibiting the flexibility of the machinability-improving layer, the above alicyclic structure is a polycyclic alicyclic structure. A formula structure (polycyclic structure) is preferred.
Furthermore, the above polycyclic structure is particularly preferably bicyclic to tetracyclic, because the (meth)acrylic acid ester copolymer has good compatibility with other components.

In the same manner as described above, from the viewpoint of effectively exhibiting the flexibility of the adhesive, the number of carbon atoms in the alicyclic structure (meaning the number of all carbon atoms in the portion forming the ring, and (meaning the total number of carbon atoms, if present) is usually preferably 5 or more, more preferably 7 or more.
On the other hand, although the upper limit of the number of carbon atoms in the alicyclic structure is not particularly limited, it is preferably 15 or less, more preferably 10 or less, from the viewpoint of compatibility as described above.

Therefore, the alicyclic structure contained in the alicyclic structure-containing monomer includes, for example, a cyclohexyl skeleton, a dicyclopentadiene skeleton, an adamantane skeleton, an isobornyl skeleton, a cycloalkane skeleton (cycloheptane skeleton, cyclooctane skeleton, cyclononane skeleton, cyclodecane skeleton, cycloundecane skeleton, cyclododecane skeleton, etc.), cycloalkene skeleton (cycloheptene skeleton, cyclooctene skeleton, etc.), norbornene skeleton, norbornadiene skeleton, cubane skeleton, basketane skeleton, hausan skeleton, spiro skeleton, and the like.

Among these, from the viewpoint of obtaining more excellent durability, a dicyclopentadiene skeleton (the number of carbon atoms in the alicyclic structure: 10), an adamantane skeleton (the number of carbon atoms in the alicyclic structure: 10) or an isobornyl skeleton (alicyclic structure) Those containing 7 carbon atoms in the cyclic structure are preferred, and those containing an isobornyl skeleton are more preferred.
Therefore, as the alicyclic structure-containing monomer, a (meth)acrylic acid ester monomer containing the above skeleton is preferable. Specifically, cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, adamantyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, (meth)acrylic acid At least one of dicyclopentenyloxyethyl and the like is included.
Moreover, among these, dicyclopentanyl (meth)acrylate, adamantyl (meth)acrylate, or isobornyl (meth)acrylate are preferred from the viewpoint of obtaining better durability, and isobornyl (meth)acrylate is preferred. More preferred, isobornyl acrylate is particularly preferred.

In addition, the (meth)acrylic acid ester copolymer preferably contains 1% by weight or more of an alicyclic structure-containing monomer with respect to the total amount of monomers as a monomer unit constituting the copolymer. It is more preferably contained in an amount of 8% by weight or more, and more preferably 8% by weight or more.
Similarly, the (meth)acrylic acid ester copolymer preferably contains 40% by weight or less of an alicyclic structure-containing monomer as a monomer unit constituting the copolymer, and may contain 30% by weight or less. More preferably, it is contained in an amount of 24% by weight or less, and particularly preferably in an amount of 18% by weight or less from the viewpoint of improving durability.
When the content of the alicyclic structure-containing monomer is within the above range, the resulting machinability-improving layer has good flexibility and can be laminated to a resin plate more excellently. Therefore, it becomes easier to satisfy the desired adhesive strength value, and it becomes easier to exhibit good durability.

(1)-4 Monomer 4 (nitrogen atom-containing monomer)
The (meth)acrylic acid ester copolymer as the main agent (A) preferably contains a monomer having a nitrogen atom in its molecule (nitrogen atom-containing monomer) as a monomer unit constituting the copolymer.
The amino group-containing monomers exemplified as reactive group-containing monomers are excluded from the nitrogen atom-containing monomers. By allowing the nitrogen atom-containing monomer to be present in the copolymer as a structural unit, the reaction between the acrylic acid ester copolymer and the thermosetting component (B) can be promoted, and the machinability improving layer has polarity. It can be added to increase the cohesive strength of the machinability-enhancing layer.

Examples of the nitrogen atom-containing monomers include monomers having a tertiary amino group, monomers having an amide group, and monomers having a nitrogen-containing heterocyclic ring. Among these, monomers having a nitrogen-containing heterocyclic ring are preferred.
Monomers having such a nitrogen-containing heterocyclic ring include, for example, N-(meth)acryloylmorpholine, N-vinyl-2-pyrrolidone, N-(meth)acryloylpyrrolidone, N-(meth)acryloylpiperidine, N-(meth) ) acryloylpyrrolidine, N-(meth)acryloylaziridine, aziridinylethyl (meth)acrylate, 2-vinylpyridine, 4-vinylpyridine, 2-vinylpyrazine, 1-vinylimidazole, N-vinylcarbazole, N-vinylphthalimide At least one such as
Among these, N-(meth)acryloylmorpholine is preferred, and N-acryloylmorpholine is more preferred, from the viewpoint of obtaining superior adhesive strength.

Examples of nitrogen atom-containing monomers other than the above-mentioned nitrogen-containing heterocyclic ring-containing monomers include (meth)acrylamide, N-methyl(meth)acrylamide, N-methylol(meth)acrylamide, N-tert-butyl (meth)acrylamide, ) acrylamide, N,N-dimethyl (meth)acrylamide, N,N-ethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-phenyl (meth)acrylamide , dimethylaminopropyl (meth)acrylamide, N-vinylcaprolactam, dimethylaminoethyl (meth)acrylate, and the like.

Then, the (meth)acrylic acid ester copolymer preferably contains 1% by weight or more of the nitrogen atom-containing monomer, more preferably 2% by weight or more, relative to the total amount of the monomer components, and 4% by weight. % or more is more preferable.
Further, the (meth)acrylic acid ester copolymer preferably contains 40% by weight or less, more preferably 30% by weight or less, of a nitrogen atom-containing monomer as a monomer unit constituting the copolymer. It is more preferably contained in an amount of 20% by weight or less, and is particularly preferably contained in an amount of 10% by weight or less in order to improve the durability.
This is because when the content of the nitrogen atom-containing monomer is within the above range, the cohesive force of the obtained machinability-improving layer is effectively improved, and the desired value of storage elastic modulus can be easily satisfied. It is because it becomes a thing excellent in durability.

(1)-5 Monomer 5 (other monomers)
The (meth)acrylic acid ester copolymer as the main component (A) preferably contains other monomers different from the monomer components described above as monomer units constituting the copolymer, if necessary.
As such other monomers, monomers containing no reactive functional groups are preferred.
Examples include alkoxyalkyl (meth)acrylates such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate, vinyl acetate, and styrene. These may be used alone or in combination of two or more.
The polymerization mode of the (meth)acrylic acid ester copolymer may be a random copolymer or a block copolymer.

(1)-6 Weight Average Molecular Weight When the main agent (A) constituting the machinability improving layer 14 is a (meth)acrylic acid ester copolymer, the weight average molecular weight (Mw) is 50,000 to 2,500,000. A value within the range is preferred.
The reason for this is that when the weight-average molecular weight of the (meth)acrylic acid ester copolymer is less than 50,000, the cohesive force is reduced, which may lead to peeling from the resin plate or markedly reduced adhesion. Because there is
On the other hand, if the weight-average molecular weight of the (meth)acrylic acid ester copolymer exceeds 2,500,000, it may become difficult to handle or the adhesion to the resin plate may deteriorate. .
Therefore, the weight average molecular weight of the (meth)acrylic acid ester copolymer is more preferably in the range of 100,000 to 1,800,000, particularly preferably in the range of 200,000 to 1,200,000. A value in the range of 10,000 is more preferable.
The weight-average molecular weight of the main component of the machinability-improving layer can be determined by GPC (gel permeation chromatography) by comparing with a previously prepared calibration curve for standard polystyrene particles.

(1)-7 Polymerization of (meth)acrylic acid ester copolymer The (meth)acrylic acid ester copolymer as the main agent (A) is obtained by polymerizing a mixture of monomers constituting the polymer by a normal radical polymerization method. It can be produced by polymerization.
Polymerization of such a (meth)acrylic acid ester copolymer can be carried out by a solution polymerization method or the like using a polymerization initiator if desired.
Examples of the polymerization solvent include ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, acetone, hexane, and methyl ethyl ketone, and two or more of them may be used in combination.

Examples of the polymerization initiator for polymerizing the (meth)acrylic acid ester copolymer include azo compounds and organic peroxides, and two or more of them may be used in combination.
More specifically, the azo compounds include, for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis(2-methylbutyronitrile), 1,1′-azobis(cyclohexane 1- carbonitrile), 2,2′-azobis(2,4-dimethylvaleronitrile), 2,2′-azobis(2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2′-azobis(2- methyl propionate), 4,4′-azobis(4-cyanovaleric acid), 2,2′-azobis(2-hydroxymethylpropionitrile), 2,2′-azobis[2-(2-imidazoline -2-yl)propane] and the like.

Examples of organic peroxides include benzoyl peroxide, t-butylperbenzoate, cumene hydroperoxide, diisopropylperoxydicarbonate, di-n-propylperoxydicarbonate, and di(2-ethoxyethyl). peroxydicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxybivalate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide, diacetyl peroxide and the like.
In addition, in the polymerization step, the weight average molecular weight of the obtained polymer can be adjusted to a desired value by blending a chain transfer agent such as 2-mercaptoethanol.

(2) thermosetting component (B)
When the composition containing the thermosetting component (B) is heated, the thermosetting component (B) undergoes a cross-linking reaction with the (meth)acrylic acid ester copolymer as the main agent (A) to form a cross-linked structure (tertiary form a network structure). As a result, a machinability-enhancing layer having a relatively high coating strength can be obtained.
The type of such a thermosetting component (B) may be any one that reacts with the main component (A) (e.g., (meth)acrylic acid ester copolymer, etc.), preferably the main component of the composition ( Any material can be used as long as it reacts with a reactive group (for example, a hydroxyl group, a carboxyl group, etc.) introduced into A).
Therefore, as the thermosetting component (B), for example, isocyanate-based cross-linking agents, epoxy-based cross-linking agents, amine-based cross-linking agents, melamine-based cross-linking agents, aziridine-based cross-linking agents, hydrazine-based cross-linking agents, aldehyde-based cross-linking agents, oxazoline-based At least one of a cross-linking agent, a metal alkoxide cross-linking agent, a metal chelate cross-linking agent, a metal salt cross-linking agent, an ammonium salt cross-linking agent and the like can be used.
The type of these thermosetting components (B) may be selected according to the reactivity of the reactive groups of the main component (A).
For example, when the reactive group of the main agent (A) is a hydroxyl group, it is preferable to blend an isocyanate-based cross-linking agent having excellent reactivity with the hydroxyl group.
Moreover, when the reactive group which the main agent (A) has is a carboxy group, it is preferable to use an epoxy-based cross-linking agent having excellent reactivity with the carboxy group.
In addition, a thermosetting component (B) can be used individually by 1 type or in combination of 2 or more types.

Moreover, the isocyanate-based cross-linking agent preferably contains at least a polyisocyanate compound.
Examples of polyisocyanate compounds include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate and xylylene diisocyanate; aliphatic polyisocyanates such as hexamethylene diisocyanate; Polyisocyanates, etc., their biuret forms, isocyanurate forms, and adduct forms which are reaction products with low-molecular weight active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, castor oil, etc. mentioned. Among these, from the viewpoint of reactivity with hydroxyl groups, at least one of trimethylolpropane-modified aromatic polyisocyanate, particularly trimethylolpropane-modified tolylene diisocyanate and trimethylolpropane-modified xylylene diisocyanate is preferred.

Examples of epoxy-based cross-linking agents include 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N',N'-tetraglycidyl-m-xylylenediamine, ethylene glycol di At least one of glycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, diglycidylaniline, diglycidylamine and the like can be mentioned.
Among these, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane is particularly preferred from the viewpoint of reactivity with carboxy groups.

Moreover, it is preferable to set the amount of the thermosetting component (B) to be within the range of 0.05 to 10 parts by weight with respect to 100 parts by weight of the main component (A).
The reason for this is that when the amount of the thermosetting component (B) is less than 0.05 parts by weight, the reactivity with the hydroxyl groups and carboxyl groups introduced into the main agent is significantly reduced, resulting in machining. This is because the desired cohesive strength of the property-enhancing layer cannot be obtained, and the desired adhesiveness cannot be exhibited in some cases. As a result, the machinability-enhancing layer may be peeled off from the resin plate, or the adhesiveness may be remarkably lowered.
On the other hand, when the amount of the thermosetting component (B) exceeds 10 parts by weight, it excessively reacts with the hydroxyl groups and carboxyl groups introduced into the main component (A), resulting in a machinability-improving layer. The cohesive force of becomes too high, and the adhesiveness may be remarkably lowered.
Therefore, it is more preferable that the amount of the thermosetting component (B) is in the range of 0.1 to 5 parts by weight, more preferably 0.3 to 1 part by weight, based on 100 parts by weight of the main agent (A). It is more preferable to set the value within the range of

(3) Active energy ray-curable component (C)
The machinability improving layer in the present embodiment preferably contains an active energy ray-curable component (C).
When such a machinability-improving layer is applied to an adherend (resin plate) and then irradiated with an active energy ray, cleavage of the photopolymerization initiator (D), which will be described later, is triggered, resulting in an active energy ray-curing property. Polymerization of component (C) is accelerated.
It is presumed that the polymerized active energy ray-curable component (C) is entwined with the crosslinked structure (three-dimensional network structure) formed by thermally cross-linking the main agent (A) and the thermosetting component (B).
Therefore, the machinability-improving layer having such a higher-order structure easily satisfies the desired adhesive strength value, exhibits excellent durability under high-temperature and high-humidity conditions, and has a desired storage elastic modulus. It becomes easy to satisfy the value of, and it becomes excellent in machinability.

Here, the active energy ray-curable component (C) is not particularly limited as long as it causes a curing reaction upon exposure to active energy ray and provides the above effects.
Moreover, the active energy ray-curable component (C) may be a monomer, an oligomer, a polymer, or a mixture thereof.
Among these, polyfunctional acrylate-based monomers having a weight average molecular weight of less than 1,000, which are excellent in compatibility with the main agent (A) and the like, are preferred.

More specifically, the polyfunctional acrylate monomer having a weight average molecular weight of less than 1000 is preferably an acrylate monomer having 2 to 6 reactive functional groups.
Examples of acrylate-based monomers having two reactive functional groups include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, Acrylate, polyethylene glycol di(meth)acrylate, neopentyl glycol adipate di(meth)acrylate, neopentylglycol hydroxypivalate di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate ) acrylate, ethylene oxide-modified phosphoric acid di(meth)acrylate, di(acryloxyethyl) isocyanurate, allylated cyclohexyl di(meth)acrylate, ethoxylated bisphenol A diacrylate, 9,9-bis[4-(2-acryloyl At least one of oxyethoxy)phenyl]fluorene and the like can be mentioned.

Examples of acrylate-based monomers having three reactive functional groups include trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, and pentaerythritol tri(meth)acrylate. At least one of meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tris(acryloxyethyl)isocyanurate, ε-caprolactone-modified tris-(2-(meth)acryloxyethyl)isocyanurate, etc. .

Furthermore, examples of acrylate-based monomers having four reactive functional groups include diglycerin tetra(meth)acrylate and pentaerythritol tetra(meth)acrylate.
Examples of the acrylate-based monomer having five reactive functional groups include at least one such as propionic acid-modified dipentaerythritol penta(meth)acrylate.
Examples of the acrylate-based monomer having six reactive functional groups include at least one of dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, and the like.

Among these, acrylate-based monomers having 3 to 6 reactive functional groups are particularly preferable from the viewpoint of durability of the machinability-improving layer.
Specifically, trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, and ε-caprolactone-modified tris-(2-(meth)acryloxyethyl)isocyanurate are particularly preferred.

As the active energy ray-curable component (C), it is also preferable to use an active energy ray-curable acrylate-based oligomer.
Examples of such acrylate oligomers include at least one of polyester acrylate, epoxy acrylate, urethane acrylate, polyether acrylate, polybutadiene acrylate, silicone acrylate, and the like.
The weight average molecular weight of such an acrylate oligomer is preferably 50,000 or less, more preferably 500 to 50,000, even more preferably 3,000 to 40,000.

Moreover, as the active energy ray-curable component (C), it is also preferable to use an adduct acrylate polymer in which a group having a (meth)acryloyl group is introduced into the side chain.
Such an adduct acrylate polymer uses a copolymer of a (meth)acrylic acid ester and a monomer having a crosslinkable functional group in the molecule, and a part of the crosslinkable functional group of the copolymer is , (meth)acryloyl group and a compound having a group reactive with a crosslinkable functional group.
The weight average molecular weight of the adduct acrylate polymer is preferably about 50,000 to 900,000, more preferably about 100,000 to 500,000.

In the present embodiment, the active energy ray-curable component (C) is preferably the polyfunctional acrylate-based monomer described above, and one type is selected from the polyfunctional acrylate-based monomer, acrylate-based oligomer, and adduct acrylate-based polymer. or two or more of them may be used in combination, or these components may be used in combination with other active energy ray-curable components.

The amount of active energy ray-curable component (C) to be blended is generally preferably in the range of 1 to 50 parts by weight per 100 parts by weight of main component (A).
The reason for this is that if the amount of the active energy ray-curable component (C) is less than 1 part by weight, the reactivity may be poor and good machinability may not be obtained. be.
On the other hand, if the amount of the active energy ray-curable component (C) exceeds 50 parts by weight, the reactivity cannot be controlled and the component reacts excessively with the main component (A), resulting in a dense crosslinked structure. This is because there is a case where the adhesive strength is lowered and good durability cannot be obtained.
Therefore, the lower limit of the amount of the active energy ray-curable component (C) is preferably 3 parts by weight or more, particularly preferably 6 parts by weight or more, with respect to 100 parts by weight of the main component (A). , 10 parts by weight or more.
On the other hand, the upper limit of the amount of the active energy ray-curable component (C) is preferably 30 parts by weight or less, particularly preferably 20 parts by weight or less, and further preferably 13 parts by weight or less. .

(4) Photoinitiator (D)
Since the active energy ray-curable component (C) can be efficiently cured by irradiation with an active energy ray, it is preferable to contain a photopolymerization initiator (D) as desired.

Examples of such photoinitiators (D) include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2 -phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexylphenylketone, 2-methyl-1-[4-(methylthio ) Phenyl]-2-morpholino-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2(hydroxy-2-propyl)ketone, benzophenone, p-phenylbenzophenone, 4,4′-diethylaminobenzophenone, dichloro Benzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4- Diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylamine benzoate, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide At least one such as

Among these, when ultraviolet rays are used as the active energy ray, it is preferable to contain a photopolymerization initiator (D) having an absorption wavelength outside the ultraviolet absorption wavelength region, and among them, the wavelength side (380 nm or more) longer than the ultraviolet region ) more preferably contains a photopolymerization initiator (D) having an absorption wavelength in the wavelength region of 380 nm to 410 nm. preferably contains 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, and the like.
The reason for this is as follows.
Since mobile electronic devices equipped with touch panels and the like are often used outdoors, there is a problem that their constituent members deteriorate due to the influence of ultraviolet rays.
In order to solve this problem, a method of suppressing deterioration due to the influence of ultraviolet rays may be taken by incorporating a member having ultraviolet absorption performance (ultraviolet shielding member) into the electronic device.
When the ultraviolet shielding member is incorporated in an electronic device in this way and ultraviolet rays are irradiated from the side of the ultraviolet shielding member, the machinability improving layer contains a photopolymerization initiator (D ), the ultraviolet rays are blocked by the ultraviolet shielding member, making it impossible to cure the machinability improving layer.
Conversely, in such a case, if a photopolymerization initiator (D) having an absorption wavelength outside the ultraviolet absorption wavelength region is used in the machinability improving layer, wavelengths outside the ultraviolet absorption wavelength region can be used. This is because it is possible to sufficiently harden the resin.

The amount of the photopolymerization initiator (D) is preferably within the range of 0.5 to 25 parts by weight with respect to 100 parts by weight of the active energy ray-curable component (C). A value in the range of up to 20 parts by weight is more preferable, and a value in the range of 5 to 15 parts by weight is even more preferable.

(5) Silane coupling agent (E)
The composition for forming the machinability-improving layer preferably further contains a silane coupling agent (E).
This is because, when the adherend includes a glass member or a resin member, the adhesion between the machinability improving layer and the adherend is improved.
Therefore, the machinability-enhancing layer containing the silane coupling agent (E) is more excellent in durability under high-temperature and high-humidity conditions.

Here, as the type of silane coupling agent (E), an organosilicon compound having at least one alkoxysilyl group in the molecule and having optical transparency is preferred.
Examples of such silane coupling agents (E) include polymerizable unsaturated group-containing silicon compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, methacryloxypropyltrimethoxysilane; 3-glycidoxypropyltrimethoxysilane; silicon compounds having an epoxy structure such as silane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyldimethoxymethylsilane Mercapto group-containing silicon compound; amino such as 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane Group-containing silicon compound; 3-chloropropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, or at least one of these and alkyl such as methyltriethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane Examples include condensates with group-containing silicon compounds. These may be used individually by 1 type, and may be used in combination of 2 or more type.

Also, the amount of the silane coupling agent (E) to be blended is preferably within the range of 0.01 to 5 parts by weight per 100 parts by weight of the main agent (A).
The reason for this is that if the amount of the silane coupling agent (E) to be blended is less than 0.01 part by weight, it may be difficult to obtain the blending effect.
On the other hand, when the amount of the silane coupling agent (E) exceeds 5 parts by weight, the silane coupling agent (E) causes the hydroxyl groups and carboxyl groups introduced into the main agent (A) to , and the thermosetting component (B) may react excessively, resulting in a significant decrease in adhesiveness.
Therefore, the compounding amount of the silane coupling agent (E) is preferably set to a value within the range of 0.1 to 3 parts by weight with respect to 100 parts by weight of the main agent (A), and 0.2 to 1 part by weight. It is more preferable to set the value within the range of

(6) Additives In order to further improve the machinability-enhancing properties and mechanical properties of the machinability-enhancing layer, in addition to the silane coupling agent (E) described above, inorganic fillers, organic fillers, inorganic fibers, organic fibers, At least one of known conductive materials, electrically insulating materials, metal ion scavengers, lightening agents, thickeners, fillers, abrasives, coloring agents, antioxidants, hydrolysis inhibitors, ultraviolet absorbers, etc. Additives are also preferably added.
When these known additives are blended, the blending amount is usually set to a value within the range of 0.1 to 50% by weight with respect to the total amount (100% by weight) of the main agent (A). is preferred, and a value within the range of 0.5 to 30% by weight is more preferred.

(7) Thickness It is preferable to set the thickness of the machinability improving layer to a value within the range of 3 to 40 μm.
The reason for this is that if the thickness of the machinability-improving layer is less than 3 μm, the desired adhesiveness cannot be exhibited, and there is a tendency for the adhesion to the resin plate and the durability to deteriorate.
On the other hand, if the thickness of the machinability-improving layer exceeds 40 μm, the machinability may deteriorate, or it may be difficult to adjust the adhesive strength, etc., within the desired range before and after the active energy ray irradiation. This is because it may become
Therefore, the thickness of the machinability-enhancing layer is more preferably in the range of 8 to 30 μm, more preferably in the range of 10 to 20 μm.

3. Predetermined Base Material Although the type of the predetermined base material is not particularly limited, functional films and release films are typically typical.

When the predetermined substrate is a functional film, its types include decorative films in touch panels, polarizing films in liquid crystal displays, retardation films, light diffusion films, light control films, antiglare films, photocatalytic films, At least one of ultraviolet shielding film, heat shielding film, antistatic film, conductive film, half-mirror film, hard coat film, decorative film, holographic film and the like can be mentioned.
The various functional films described above have various functions (decorative properties, light polarization properties, light phase properties, light diffusion properties, light control properties) on the surface of PET film, PEN film, acrylic film, polycarbonate film, or TAC film. , anti-glare properties, UV shielding properties, heat shielding properties, anti-static properties, conductivity, half-mirror properties, hard coating properties, decorative properties, holographic properties, etc.). is appropriately selected depending on the purpose.

The thickness of the functional film as the predetermined base material is determined in consideration of the application, light transmittance, etc., and is usually preferably in the range of 10 to 300 μm.
The reason for this is that if the thickness of the functional film is less than 10 μm, the mechanical strength and durability may be remarkably lowered.
On the other hand, if the thickness of the functional film exceeds 300 μm, the sensitivity may be lowered and the transparency of active energy rays may be significantly lowered when used in a touch panel or the like.
Therefore, the thickness of the functional film is more preferably in the range of 20-250 μm, more preferably in the range of 30-200 μm.

When the predetermined substrate is a release film, the type thereof is at least one of a polyester film having a release surface (PET film, etc.), an olefin film, an acrylic film, a urethane film, a polycarbonate film, a TAC film, a fluorine film, a polyimide film, and the like. One is mentioned.
The release surface in this specification includes both a surface that has been subjected to a release treatment and a surface that exhibits releasability without being subjected to a release treatment.

The thickness of the release film as the predetermined base material is determined in consideration of the application, light transmittance, etc., and is usually preferably in the range of 10 to 300 μm.
The reason for this is that if the release film has a thickness of less than 10 μm, the mechanical strength and durability may be significantly reduced.
On the other hand, if the thickness of the release film exceeds 300 μm, the release film may roll up or become difficult to handle.
Therefore, the thickness of the release film is more preferably in the range of 20 to 250 μm, more preferably in the range of 30 to 200 μm.

As for the optical properties of the predetermined base material (functional film, release film, etc.), it is preferable that the base material has transparency suitable for applications such as touch panels and liquid crystal display devices.
That is, the lower limit of the visible light transmittance of the resin plate is preferably 60% or more, more preferably 75% or more, and even more preferably 85% or more.
The upper limit of the visible light transmittance of the resin plate is usually 100% or less, preferably 99.9% or less, more preferably 99% or less, and 98% or less. It is more preferable to set it as a value.

4. Various physical properties of the machinability-enhancing layer (1) Storage modulus (M1) before active energy ray irradiation
The machinability-improving layer according to the present embodiment preferably has a storage modulus (M1) before irradiation with an active energy ray within the range of 0.01 to 1 MPa.
The reason for this is that by controlling the storage elastic modulus (M1) within a predetermined range, the flexibility of the machinability-improving layer before irradiation with active energy rays becomes moderate, and the bonding property to the resin plate is good. It is to become a thing.
Therefore, it is more preferable to set the storage modulus (M1) before active energy ray irradiation to a value within the range of 0.04 to 0.20 MPa, and furthermore, to achieve both durability and machinability after active energy ray irradiation. It is more preferable to set the value within the range of 0.07 to 0.08 MPa because it is easy to
In this specification, unless otherwise specified, it means the storage modulus (M1, M2) corresponding to a temperature of 25°C (the same shall apply hereinafter).

(2) Storage modulus after active energy ray irradiation (M2)
The machinability improving layer according to the present embodiment is characterized by having a storage modulus (M2) of 0.20 MPa or more after irradiation with active energy rays.
The reason for this is that by controlling the storage modulus (M2) to a value of 0.20 MPa or more, when the machinability improving film is attached to a resin plate and cut with a cutting device, the machine This is because the occurrence of chipping and protrusion due to the workability-enhancing layer is suppressed, and good machinability can be obtained.
Therefore, the lower limit of the storage modulus (M2) is preferably 0.22 MPa or more, more preferably 0.25 MPa or more, and even more preferably 0.30 MPa or more.
On the other hand, if the value of the storage elastic modulus (M2) is excessively large, the durability may decrease.
Therefore, the upper limit of the storage modulus (M2) is preferably 5 MPa or less, more preferably 2 MPa or less, particularly preferably 1 MPa or less, and 0.6 MPa or less. It is more preferable that

Here, with reference to FIG. 2, the relationship between the storage modulus (M2) of the machinability-enhancing layer after irradiation with active energy rays and machinability will be described.
FIG. 2 is based on evaluation results according to Examples and Comparative Examples to be described later, and the horizontal axis represents the storage modulus (M2) (MPa) of the machinability-enhancing layer after irradiation with active energy rays. , and the vertical axis indicates the value of machinability evaluation (relative value).
The value of the machinability evaluation (relative value) is calculated by setting ◎ to 5 points, ○ to 3 points, Δ to 1 point, and × to 0 points in the machinability evaluation of Examples and Comparative Examples described later. It is a relative numerical value.
From FIG. 2, when the value of the storage elastic modulus (M2) is less than 0.2 MPa, the machinability evaluation (relative value) is 0 points, but when it is 0.20 MPa or more, the machinability evaluation (relative value) tends to increase.
Then, when the value of the storage modulus (M2) is about 0.25 to 0.3 MPa, the machinability evaluation (relative value) value is further increased to about 3 to 5 points, and further 0.3 MPa. In the above, it can be seen that the machinability evaluation (relative value) is the highest 5 points.
Therefore, from FIG. 2, relatively good machinability can be obtained by setting the value of the storage elastic modulus (M2) after irradiation with active energy rays to at least 0.2 MPa, and furthermore, the higher the value, the more , it can be understood that machinability is improved.

(3) Increase rate of storage modulus (M2/M1×100)
The machinability-improving layer according to the present embodiment has an increase rate (=M2/M1×100) of the storage elastic modulus (M1) before irradiation with active energy rays with respect to the storage elastic modulus (M2) after irradiation with active energy rays. , it is usually preferable to set the value within the range of 320 to 30000%.
The reason for this is that by controlling the increase rate (%) of the storage elastic modulus described above to a value within a predetermined range, the bonding property to the resin plate before the active energy ray irradiation and the durability before and after the active energy ray irradiation and machinability are easily compatible with each other.
Therefore, it is more preferable to set the rate of increase in storage elastic modulus to a value within the range of 350 to 10,000%, and more preferably to a value within the range of 380 to 1,000%.

(4) Gel fraction before active energy ray irradiation (G1)
The machinability-improving layer according to the present embodiment preferably has a gel fraction (G1) before irradiation with an active energy ray, usually within a range of 40 to 78%.
The reason for this is that by controlling the gel fraction (G1) to a value within a predetermined range, it is possible to improve the adhesion to the resin plate.
More specifically, when the gel fraction (G1) is less than 40%, the handling properties of the machinability-improving film may deteriorate due to insufficient cohesion of the machinability-improving layer.
On the other hand, when the gel fraction (G1) described above exceeds 78%, the machinability improving layer becomes too hard, and the lamination property to the resin plate deteriorates, resulting in deterioration of durability. sometimes.
Therefore, the gel fraction (G1) is more preferably set to a value within the range of 50-76%, and more preferably set to a value within the range of 60-72%.
A method for measuring the gel fraction (G1) will be described in detail in Examples described later.

(5) Gel fraction after active energy ray irradiation (G2)
The machinability-enhancing layer according to the present embodiment preferably has a gel fraction (G2) of 60% or more after irradiation with active energy rays.
The reason for this is that if the gel fraction (G2) is less than 60%, the machinability may be remarkably lowered and adhesive residue may occur.
Therefore, the lower limit of the gel fraction (G2) is more preferably 70% or more, particularly preferably 75% or more, and even more preferably 77% or more.
The upper limit of the gel fraction (G2) is not particularly limited, but it may be 100%, but from the viewpoint of achieving both machinability and durability, it is preferably 95% or less, and 90% or less. Especially preferred.
A method for measuring the gel fraction (G2) will be described in detail in the examples below.

(6) Increase rate of gel fraction (G2/G1×100)
The machinability-improving layer according to the present embodiment has an increase rate (=G2/G1×100) of the gel fraction (G1) before active energy ray irradiation with respect to the gel fraction (G2) after active energy ray irradiation. , it is usually preferable to set the value within the range of 110 to 250%.
The reason for this is that by controlling the increase rate of the gel fraction to a value within a predetermined range, the bonding property to the resin plate before the active energy ray irradiation becomes suitable, and after the active energy ray irradiation This is because durability and machinability are easily compatible.
More specifically, if the increase rate of the gel fraction is less than 110%, the machinability may deteriorate, causing chipping of the machinability-improving layer, or the like, or lowering the durability. .
On the other hand, if the increase rate of the gel fraction exceeds 250%, the machinability improving layer may become brittle and crack.
Therefore, the increase rate of the gel fraction is more preferably in the range of 114 to 200%, more preferably in the range of 120 to 160%, and more preferably in the range of 128 to 140%. value is particularly preferred.

(7) Adhesive strength before active energy ray irradiation (P1)
The machinability-improving film according to the present embodiment preferably has an adhesive strength (P1) before irradiation with an active energy ray within the range of 1 to 60 N/25 mm.
The reason for this is that by controlling the adhesive force (P1) to a value within a predetermined range, the adhesiveness to the resin plate is improved.
If the adhesive strength (P1) is less than 1 N/25 mm, it will be difficult to bond to the resin plate in the first place. It may become easy to cause trouble to do.
On the other hand, if the adhesive strength (P1) exceeds 60 N/25 mm, handleability may deteriorate.
Therefore, it is more preferable to set the adhesive strength (P1) to a value within the range of 8 to 40 N/25 mm, and more preferably to a value of 15 to 30 N/25 mm.
The adhesive strength (P1) can be measured by a 180° peeling method according to JIS Z0237:2009 before irradiation with active energy rays, but a more specific measuring method is described in Examples described later. As shown.

(8) Adhesive strength after active energy ray irradiation (P2)
The machinability-improving film according to the present embodiment is characterized by having an adhesive strength (P2) after irradiation with active energy rays of 10 N/25 mm or more.
The reason for this is that by controlling the adhesive strength (P2) to a value of 10 N/25 mm or more, good adhesion can be obtained and excellent durability can be exhibited.
Therefore, the lower limit of the adhesive strength (P2) is preferably 15 N/25 mm or more, more preferably 20 N/25 mm or more, and even more preferably 24 N/25 mm or more.
On the other hand, the upper limit of the adhesive strength (P2) is preferably 200 N/25 mm or less, more preferably 120 N/25 mm or less, and even more preferably 60 N/25 mm or less. , 40 N/25 mm or less is particularly preferred.
The adhesive strength (P2) can also be measured by a 180-degree peeling method according to JIS Z0237:2009 after irradiation with active energy rays, but a more specific measuring method is described in Examples described later. as shown in

(9) Increase rate of adhesive strength (P2/P1 x 100)
In the machinability-improving film according to the present embodiment, the increase rate (=P2/P1×100) of the adhesive strength (P1) before active energy ray irradiation with respect to the adhesive strength (P2) after active energy ray irradiation is 80 to A value of 300% is preferred.
The reason for this is that by controlling the rate of increase in adhesive strength to a value within a predetermined range, it is possible to achieve both sticking property to a resin plate before irradiation with active energy rays and durability after irradiation with active energy rays. This is because it becomes easier.
Therefore, it is more preferable to set the rate of increase in adhesive strength to a value within the range of 100 to 200%, and more preferably to a value within the range of 120 to 140%.

(10) Maximum stress (S2)
The machinability-improving film according to the present embodiment preferably has a maximum stress (S2) of 1.5 N/mm ² or more when the tensile stress after irradiation with active energy rays is measured.
The reason for this is that by setting the maximum stress (S2) to a value of 1.5 N/mm ² or more, chipping of the machinability improving layer tends to be suppressed during machining, and machinability is improved. Because.
Therefore, the maximum stress (S2) is more preferably set to a value of 2.0 N/mm ² or more, and more preferably set to a value of 2.5 N/mm ² or more from the viewpoint of compatibility with durability.
On the other hand, the upper limit of the maximum stress (S2) is not particularly limited, but from the viewpoint of achieving both durability and machinability, it is preferably a value of 20 N/mm ² or less, and a value of 10 N/mm ² or less. is more preferable, and it is particularly preferable to set the value to 4 N/mm ² or less.

(11) Stress at 100% elongation (E2)
The machinability-improving film according to the present embodiment preferably has a stress (E2) at 100% elongation after irradiation with active energy rays, which is usually 10 N/mm ² or less.
The reason for this is that by setting the stress at 100% elongation (E2) to a value of 10 N/mm ² or less, the machinability-improving layer tends to be difficult to stretch during machining, and the machinability-improving layer after cutting. This is because it is possible to obtain a cut surface without protruding, which in turn improves the machinability.
Therefore, it is more preferable to set the upper limit of the stress at 100% elongation (E2) to a value of 6 N/mm ² or less, and from the viewpoint of compatibility with durability, it is preferable to set the value to 1 N/mm ² or less. More preferred.
On the other hand, the lower limit of the stress at 100% elongation (E2) is not particularly limited, but from the viewpoint of achieving both durability and machinability, a value of 0.1 N / mm ² or more is preferable, and 0.4 N /mm ² or more, and particularly preferably 0.7 N/mm ² or more.

5. Laminate The laminate using the machinability-improving film according to the present embodiment is a laminate composed of a resin plate 12 formed by laminating a machinability-improving film 18 shown in FIG. If there is, it is not particularly limited.
Therefore, various functional films used in various devices can be precisely machined (cut) together with the resin plate via the machinability improving layer, and can be easily formed into a laminate of functional films with the resin plate. can be manufactured to
Hereinafter, aspects of such a laminate will be specifically described.

(1) Laminate before curing with active energy ray The laminate before curing with active energy ray is shown in FIGS. It is a laminate 10 in which a functional film as a predetermined base material 16, a machinability improving film 18, and a resin plate 12 are sequentially laminated.
3 to 5 will be specifically described as a method of using the machinability-enhancing film, which will be described later.

(2) Laminate after active energy ray curing The laminate after active energy ray curing is irradiated with an active energy ray from the predetermined base material 16 or the resin plate 12 side of the laminate before active energy ray curing. Thus, the machinability-enhancing layer 14 can be used as the machinability-enhancing layer 14' after curing.
That is, as shown in FIGS. 3(d) and 3(e), FIGS. 4(e) and 4(f), FIGS. 5(e) and 5(f), the functionality as the predetermined base material 16 It is a laminate 10' in which a film, a machine workability improving layer 14' after curing, and a resin plate 12 are sequentially laminated.

The cured machinability-improving layer 14' is obtained by curing the machinability-improving layer 14 of the machinability-improving film 18 described above by irradiation with active energy rays.
In this embodiment, the cured machinability-improving layer 14' has a crosslinked structure composed of a (meth)acrylic acid ester copolymer as a main agent (A) and a thermosetting component (B). Together, it consists of an adhesive containing a structure (polymerized structure) in which the active energy ray-curable component (C) is polymerized and cured.
The polymerized structure is presumed to be entwined with a crosslinked structure composed of the (meth)acrylic acid ester copolymer as the main agent (A) and the thermosetting component (B).
By having a structure in which a plurality of three-dimensional structures are intertwined, the machinability-improving layer 14' after curing has a high cohesive force, and easily satisfies the desired adhesion and storage modulus values. Become.
Therefore, the hardened machinability-enhancing layer 14' exhibits excellent machinability as well as excellent durability.

As long as the effects of the present invention can be obtained, the post-curing machinability-improving layer 14' contains a photopolymerization initiator (D) that has not been cleaved by active energy ray irradiation. good too.
In the present embodiment, the residual amount of the photopolymerization initiator in the machinability improving layer 14' after curing is preferably 0.1% by mass or less, and more preferably 0.01% by mass or less. .

6. Usage Method The usage method of the machinability-enhancing film 18 preferably includes the following steps (1) to (4), as illustrated in FIGS. 3(a) to 3(e).
(1) A composition containing an active energy ray-curable component (a resin layer 13 derived from a composition for forming a machinability improving layer) is applied to the surface of a functional film as a predetermined base material 16. , heat treatment to form a machinability-improving film 18 having an active energy ray-curable machinability-improving layer 14; Step (3) irradiating active energy rays from the side of the resin plate 12 or the predetermined base material 16 to cure the active energy ray-curable component in the machinability improving layer 14 to form the machinability improving layer 14' after curing. (4) A step of applying a predetermined machining treatment to the laminated body 10' including the cured machinability improving layer 14' and the resin plate 12. Hereinafter, referring to the drawings as appropriate, machinability A method of using the enhancement film 18 will be specifically described.

6-1: Step (1)-1
Step (1)-1 is a step of preparing a composition for forming a machinability improving layer.
Therefore, the resin layer 13 derived from the composition for forming the machinability improving layer shown in FIG. It is composed of a composition containing a thermosetting component (B) and an active energy ray-curable component (C) as main components.
The composition can contain a photopolymerization initiator (D), a silane coupling agent (E), an organic solvent, etc., as necessary, and by uniformly mixing these, the resin layer 13 described above can be obtained. Therefore, a coating liquid can be obtained.

6-2: Step (1)-2
Step (1)-2 is a step of applying a coating liquid containing the predetermined composition described above.
Therefore, as shown in FIG. 3A, the surface of a predetermined base material 16 (functional film or the like) is coated with the coating liquid of the composition described above to form a machinability improving layer together with the predetermined base material 16. A laminate is obtained in which a resin layer 13 derived from a composition for carrying out is laminated.
A method for applying the coating liquid is not particularly limited, and a known method can be used.
Examples include bar coating, knife coating, roll coating, blade coating, die coating, and gravure coating.
Then, as shown in FIG. 3(b), a predetermined heat treatment (H) is applied to cause a thermal cross-linking reaction between the functional groups contained in the main component (A) and the thermosetting component (B), thereby activating the A machinability-improving film 18 is obtained by forming the energy ray-curable machinability-improving layer 14 .
The heat treatment (H) can also serve to remove scattering of the solvent or the like contained in the coating liquid of the composition described above.
At that time, specifically, the heating temperature of the heat treatment (H) is preferably 50 to 150°C, more preferably 70 to 120°C.
The heating time is preferably 10 seconds to 10 minutes, more preferably 50 seconds to 2 minutes.
Furthermore, after the heat treatment, it is preferable to provide a curing period of about 1 to 2 weeks at normal temperature (eg, 23° C., 50% RH).
By such heat treatment (and curing), the (meth)acrylate copolymer is satisfactorily crosslinked via the thermosetting component (B) to form a crosslinked structure.
That is, through such steps, the machinability-improving layer 14 is obtained by thermally cross-linking the resin layer 13 derived from the composition for forming the machinability-improving layer, and the machinability-improving layer 14 has a predetermined machinability. It becomes the improvement film 18 .
Note that other components contained in the composition for forming the machinability-improving layer (active energy ray-curable component (C), photopolymerization initiator (D), coupling agent (E), etc.) The content, properties, etc. do not change before and after cross-linking.

6-3: Step (2)
Next, step (2) is a step of laminating the machinability improving film on the resin plate.
Therefore, as shown in FIG. 3(c), the resin plate 12 and the machinability improving layer 14 of the machinability improving film 18 are bonded and laminated.
For bonding the resin plate 12 and the machinability improving film 18, a known bonding method such as a lamination method can be used.
As a result, the laminate 10 in which the active energy ray-curable machinability improving layer 14 is sandwiched between the predetermined base material (functional film or the like) 16 and the resin plate 12 can be obtained.

6-4: Step (3)
Next, step (3) is a step of irradiating with active energy rays.
Therefore, as shown in FIG. 3D, active energy rays (L) such as ultraviolet rays are irradiated from the back side of the predetermined base material 16 .
As a result, the active energy ray-curable component (C) in the machinability-improving layer 14 is cured to form a cured machinability-improving layer 14'.
That is, it is possible to obtain the laminate 10 ′ in which the cured machinability improving layer 14 ′ is sandwiched between the predetermined base material 16 (functional film or the like) and the resin plate 12 .
In FIG. 3(d), the active energy ray (L) is irradiated from the back side of the resin plate 12. The active energy ray (L) may be irradiated from the side opposite to the side, and further, from both the back side of the resin plate 12 and the side of the predetermined base material 16 (functional film etc.), the active energy ray ( L) may be irradiated.

Here, the active energy ray refers to an electromagnetic wave or a charged particle beam that has energy quanta, and specifically includes ultraviolet rays, electron beams, and the like.
The active energy ray in this embodiment is preferably an active energy ray containing light having a wavelength of 200 to 450 nm.
In order to obtain an active energy ray that satisfies the above conditions, for example, a light source capable of irradiating ultraviolet rays, such as a high-pressure mercury lamp, a fusion H lamp, and a xenon lamp, may be used.
The irradiation amount of active energy rays is preferably a value within the range of illuminance from 50 to 1000 mW/cm ² .
The amount of light is preferably 50 mJ/cm ² or more, more preferably 80 mJ/cm ² or more, and even more preferably 200 mJ/cm ² or more.
Also, the amount of light is preferably 10000 mJ/cm ² or less, more preferably 5000 mJ/cm ² or less, and even more preferably 2000 mJ/cm ² or less.

6-5: Step (4)
Step (4) is a machining process step.
Therefore, as shown in FIG. 3(e), a resin plate 12 laminated with a predetermined base material 16 (functional film or the like) and a machinability improving layer 14' is subjected to a predetermined machining process (for example, , cutting in the direction indicated by the arrow A).
Further, since the machinability-improving film of the present embodiment has excellent machinability, a laminate having a desired shape can be easily obtained by a single cutting process.
Furthermore, since the machinability-enhancing layer does not chip or stretch during the cutting process, the machined surface after machining is good, and the resulting laminate has excellent appearance quality.
In addition, since the obtained laminate is excellent in durability, it can also be applied to optical parts used in harsh environments (for example, an in-vehicle touch panel, a liquid crystal display device, etc.).
Therefore, by using the machinability-improving film of the present embodiment as described above, it is possible to obtain a resin with a functional film via the machinability-improving layer, which can be applied to optical parts such as touch panels and liquid crystal display devices. A board can be manufactured simply.

7. Other Usage 7-1 Modification 1
The steps exemplified in FIGS. 4A to 4F are examples of steps in the case of using the predetermined base material 16' (release film, etc.) in the step (1) described above.
Therefore, for example, when using a predetermined base material 16' (release film, etc.), by including the following steps (1') to (4') as illustrated in FIGS. , the machinability improving film 18 can be suitably used for machining (cutting).

(1) Step (1')
Step (1') is a heat treatment step.
Therefore, as shown in FIGS. 4(a) and 4(b), a resin layer 13 derived from a composition for forming a machinability-improving layer is formed on the surface of a predetermined base material 16' (release film or the like). is applied and subjected to heat treatment (H) to form a machinability-enhancing film 18' including the machinability-enhancing layer 14. FIG.
Here, the preparation step and coating step of the composition for forming the machinability-improving layer conform to Steps (1)-1 and (1)-2 described above.
Although not shown, in FIG. 4B, a predetermined base material 16' (release film or the like) may be provided on one surface of the machinability improving layer 14. As shown in FIG.
With such a configuration, the risk of contamination of the machinability-enhancing layer 14 before use is reduced.

(2) Step (2')
Next, step (2') is a step of laminating the machinability improving film on the resin plate.
That is, as shown in FIGS. 4(c) and 4(d), the exposed surface of the machinability-improving layer 14 of the machinability-improving film 18' is laminated to the predetermined substrate 16 (functional film). to laminate.
Then, the predetermined base material 16' (separation film or the like) is peeled off, and the resin plate 12 is laminated.
Thereby, the laminate 10 in which the active energy ray-curable machinability improving layer 14 is sandwiched between the predetermined base material 16 (functional film or the like) and the resin plate 12 can be obtained.

(3) Step (3')
Next, step (3') is an active energy ray irradiation step.
Therefore, as shown in FIG. 4(e), the active energy ray (L) is irradiated to cure the active energy ray-curable component (C) contained in the machinability improving layer 14, thereby improving the machinability. Layer 14'. That is, it is possible to obtain the laminate 10 ′ in which the cured machinability improving layer 14 ′ is sandwiched between the predetermined base material 16 (functional film or the like) and the resin plate 12 .
In addition, the irradiation conditions of the active energy ray and the like conform to the step (3) described above.

(4) Step (4')
Step (4') is a machining step.
Therefore, as shown in FIG. 4(f), a predetermined machining process (for example, Cutting processing in the direction indicated by arrow A) is performed.
Also in the steps (1′) to (4′) described above, the machinability-improved film of the present embodiment can be suitably used as in the steps (1) to (4) described above.
Therefore, also in Modification 1, it is possible to easily manufacture a resin plate with a functional film via a machinability improving layer, which is applicable to optical parts such as touch panels and liquid crystal display devices.

7-2 Modification 2
The steps illustrated in FIGS. 5A to 5F are examples of steps in which the machinability improving film 18' is laminated in a different order in the step (2') of Modification 1 described above.
That is, as shown in FIG. 5C, one surface of the machinability improving layer 14 of the machinability improving film 18' shown in FIG. do.
Then, as shown in FIG. 5(d), the predetermined base material 16' (release film or the like) is peeled off, and the predetermined base material 16 (functional film) is laminated. In addition, except for the step (2') described above, it conforms to the modified example 1 described above.
Therefore, also in Modification 2, the machinability-improved film of the present embodiment is preferably used in the same manner as in the above-described steps (1) to (4) and the above-described steps (1') to (4'). be able to.
Therefore, even in the steps (1′) to (4′), it is possible to easily manufacture a resin plate with a functional film through the machinability improving layer, which can be applied to optical parts such as touch panels and liquid crystal display devices. can do.

Hereinafter, the machinability-improving film of the present embodiment and the method of using the machinability-improving film will be described in more detail with reference to examples.
However, the present embodiment is not limited to the description of these examples for no particular reason.

[Example 1]
1. Preparation and use of film with improved machinability 1-(1) Preparation of main agent (A) Based on 100 parts by weight of the total monomer component, 30 parts by weight of butyl acrylate, 25 parts by weight of 2-ethylhexyl acrylate, and isoborane 10 parts by weight of nil acrylate, 5 parts by weight of methyl methacrylate, 5 parts by weight of acryloylmorpholine, and 25 parts by weight of 2-hydroxyethyl acrylate are solution-polymerized to obtain a (meth)acrylic acid ester co-polymer as the main agent (A). A polymer was prepared.
The weight average molecular weight (Mw) of the obtained (meth)acrylic acid ester copolymer was measured by the method described below and found to be 500,000.

Moreover, this weight average molecular weight (Mw) is the weight average molecular weight of polystyrene conversion measured on the following conditions (GPC measurement) using a gel permeation chromatography (GPC).
(Measurement condition)
・ GPC measurement device: HLC-8020 manufactured by Tosoh Corporation
・ GPC column (passed in the following order): TSK guard column HXL-H manufactured by Tosoh Corporation
TSK gel GMHXL (x2)
TSK gel G2000HXL
・Measurement solvent: tetrahydrofuran ・Measurement temperature: 40°C

Details such as abbreviations in Table 1 are as follows.
(Main agent (A): ((meth)acrylate copolymer))
BA: butyl acrylate 2EHA: 2-ethylhexyl acrylate IBXA: isobornyl acrylate MMA: methyl methacrylate ACMO: N-acryloyl morpholine HEA: 2-hydroxyethyl acrylate AA: acrylic acid 4HBA: 4-hydroxybutyl acrylate HEMA: methacrylic Acid 2-hydroxyethyl

1-(2) Adjustment of composition for forming machinability-improving layer 0.3 parts by weight of trimethylolpropane-modified tolylene diisocyanate as (B) and 8 parts by weight of ε-caprolactone-modified tris-(2-acryloxyethyl) isocyanurate as active energy ray-curable component (C). and 0.8 parts by weight of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide as a photopolymerization initiator (D) and 3-glycidoxypropyltrimethoxy as a silane coupling agent (E). Silane was blended at a ratio of 0.3 parts by weight, stirred until uniform, and diluted with methyl ethyl ketone to obtain a coating solution having a solid content concentration of 30% by weight.

Details such as abbreviations in Table 2 are as follows.
(Thermosetting component (B))
B1: trimethylolpropane-modified tolylene diisocyanate B2: trimethylolpropane-modified xylene diisocyanate B3: 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane (active energy ray-curable component (C))
C1: ε-caprolactone-modified tris-(2-acryloxyethyl) isocyanurate C2: trimethylolpropane triacrylate C3: dipentaerythritol hexaacrylate

1-(3) Step of Forming Machinability-Enhancing Layer The resulting coating solution was applied to a heavy-release type release film (manufactured by Lintec Corporation, product name "SP-PET752150 ”) was applied using a bar coater to a thickness of 15 μm after drying.
Then, the coating layer is heat-treated at 90° C. for 1 minute to allow the thermal crosslinking reaction to proceed, and a (meth)acrylic acid ester copolymer as the main agent (A) and a thermosetting component (B) are formed. A machinability-enhancing layer having a crosslinked structure was formed.

Next, the coating layer on the heavy release release film obtained above and a light release release film (manufactured by Lintec, product name "SP-PET382120") in which one side of the polyethylene terephthalate film is release-treated with a silicone release agent. is laminated so that the release-treated surface of the light release release film is in contact with the machinability improving layer, and cured for 7 days under conditions of 23 ° C. and 50% RH to obtain a heavy release release. A machinability-improving film for evaluation consisting of a film/a machinability-improving layer (thickness: 15 μm)/lightly peelable release film was prepared.
The thickness of the machinability-enhancing layer is a value measured using a constant-pressure thickness gauge (manufactured by Teclock, product name "PG-02") in accordance with JIS K7130.

2. Evaluation of machinability-improved film 2-(1) Measurement of adhesive strength (P1) before irradiation with active energy ray Of the machinability-improved film for evaluation, peel off the light release type release film from the machinability-improved layer. , A polyethylene terephthalate (PET) film having an easy-adhesive layer (manufactured by Toyobo Co., Ltd., product name "PET A4300", thickness: 100 μm) is laminated to an easy-adhesive layer, and a heavy-release type release film / machinability improvement layer ( 15 μm)/PET film laminate was obtained.
The laminate thus obtained was cut into a piece having a width of 25 mm and a length of 150 mm, which was used as a sample.
In an environment of 23 ° C. and 50% RH, peel the heavy release type release sheet from the sample obtained above, attach the exposed machinability improving layer to the glass plate, and then reciprocate a 2 kg roller once. crimped by
Then, after leaving it for 24 hours under the conditions of 23 ° C. and 50% RH, using a tensile tester (manufactured by Orientec, Tensilon), the adhesive strength (P1 , N/25 mm) were measured.
In addition, the conditions other than those described here were measured according to JIS Z 0237:2000. Table 2 shows the results.

2-(2) Measurement of adhesive strength (P2) after irradiation with active energy ray In an environment of 23 ° C. and 50% RH, the heavy release type release sheet was peeled off from the sample obtained above, and the exposed machinability After the improvement layer was attached to the glass plate, it was pressure-bonded by reciprocating a 2 kg roller once, and irradiated with ultraviolet rays as active energy rays from the PET film side under the following conditions.
Then, after leaving it for 24 hours under conditions of 23 ° C. and 50% RH, using a tensile tester (manufactured by Orientec, Tensilon), active energy ray irradiation was performed under the conditions of a peel speed of 300 mm / min and a peel angle of 180 degrees. Post adhesion (P2, N/25 mm) was measured.
In addition, the conditions other than those described here were measured according to JIS Z 0237:2000. Table 2 shows the results.
<Ultraviolet irradiation conditions>
・Using a high-pressure mercury lamp ・Illuminance 200mW/cm ² , Light intensity 2000mJ/cm ²
・The UV illuminance/light meter uses “UVPF-A1” manufactured by Eye Graphics.

2-(3) Calculation of increase rate of adhesive strength Increase rate of adhesive strength (P2) after active energy ray irradiation with respect to adhesive strength (P1) before active energy ray irradiation measured above (= P2 / P1 × 100 , %) were calculated. Table 2 shows the results.

2-(4) Measurement of gel fraction (G1) before irradiation with active energy ray Of the obtained machinability-improving film for evaluation, only the machinability-improving layer was wrapped in a polyester mesh (mesh size 200), The mass was weighed with a precision balance, and the mass of the mesh alone was subtracted to calculate the mass of the machinability improving layer alone. Let the mass at this time be m1.
Next, the machinability-improving layer wrapped in the polyester mesh produced by the above method was immersed in ethyl acetate at room temperature (23° C.) for 72 hours.
After that, the machinability-enhancing layer wrapped in a polyester mesh was taken out, air-dried for 24 hours in an environment with a temperature of 23°C and a relative humidity of 50%, and further dried in an oven at 80°C for 12 hours. .
After drying, the mass was weighed with a precision balance, and the mass of the machinability improving layer alone was calculated by subtracting the mass of the mesh alone. Let the mass at this time be m2.
Based on the mass calculated above, the gel fraction (G1) (=(m2/m1)×100, %) of the machinability improving layer before irradiation with active energy rays was derived. Table 2 shows the results.

2-(5) Measurement of gel fraction (G2) after irradiation with active energy ray After peeling off the light release type release film from the obtained machinability-improving film for evaluation, the exposed machinability-improving layer was subjected to The active energy ray was directly irradiated under the conditions described above to cure the machinability improving layer.
For this cured machinability-improving layer, the gel fraction (G2) of the machinability-improving layer after irradiation with active energy rays was derived in the same manner as described above. Table 2 shows the results.

2-(6) Calculation of gel fraction increase rate Increase rate (= G2/ G1×100, %) was calculated. Table 2 shows the results.

2-(7) Measurement of maximum stress (S2) and stress at 100% elongation (E2) Peel off the light release type release film from the obtained machinability-improving film for evaluation, and measure the exposed machinability-improving layer. Then, an active energy ray was directly irradiated under the conditions described above to cure the machinability improving layer.
The maximum stress (S2, N/mm ² ) and the stress at 100% elongation (E2, N/mm ² ) of only this cured machinability-enhancing layer were measured using a tensile tester (manufactured by Orientec, Tensilon, peeling speed of 200 mm/min).
The measurement was performed under conditions other than those described here in accordance with JIS K 7162-2:2014. Table 2 shows the results.

2-(8) Measurement of storage modulus (M1) before irradiation with active energy ray Of the obtained machinability-improved film for evaluation, only the machinability-improved layer was measured according to JIS K7244-4: 1999, Measure the storage modulus (M1, MPa (25°C)) of the machinability-enhancing layer before irradiation with active energy rays using a viscoelasticity measuring device (manufactured by TA Instruments, ARES, frequency 1 Hz). did. Table 2 shows the results.

2-(9) Measurement of storage elastic modulus (M2) after irradiation with active energy ray After peeling off the light-release type release film from the obtained machinability-improving film for evaluation, the exposed machinability-improving layer was subjected to The active energy ray was directly irradiated under the conditions described above to cure the machinability improving layer.
The storage elastic modulus (M2, MPa (25° C.)) of the machinability-improving layer after irradiation with active energy rays was measured under the same conditions as above for only this cured machinability-improving layer. Table 2 shows the results.

2-(10) Calculation of increase rate of storage elastic modulus Increase rate (= M2/ M1×100, %) was calculated. Table 2 shows the results.

2-(11) Evaluation of machinability The light release type release sheet of the obtained film for improving machinability for evaluation was peeled off, and the exposed machinability improving layer was attached to a PET film (100 µm).
Further, the heavy release type release sheet was peeled off, and the exposed machinability improving layer was attached to a PET film (100 μm) to obtain a test piece.
After curing the machinability improving layer by irradiating the active energy ray under the conditions described above, the test piece was cut vertically with respect to one PET film surface of the test piece using a cutter.
Then, the cut surface was observed under a microscope, and machinability was evaluated according to the following criteria.
A: No chipping or elongation of the machinability-enhancing layer was observed, and the cut surface was good.
◯: Slight chipping and elongation of the machinability-enhancing layer were observed, but the cut surface was practically satisfactory.
Δ: Chipping and elongation of the machinability-enhancing layer were observed, and the cut surface was practically unfavorable.
x: Chipping and elongation of the machinability-enhancing layer were observed, and the cut surface was practically unusable.

2-(12) Evaluation of Durability The light release type release sheet of the obtained film for improving machinability for evaluation was peeled off, and the exposed machinability improving layer was treated with polymethyl methacrylate (PMMA) and polycarbonate (PC). was attached to the surface of the polycarbonate side of the laminated resin plate (thickness: 1 mm, containing an ultraviolet absorber).
Furthermore, a test piece was obtained by peeling the heavy release type release sheet from the machinability-improving film for evaluation and attaching the exposed machinability-improving layer to a TAC film (thickness: 100 μm) as a functional film. rice field. The obtained test piece was autoclaved under conditions of 50° C. and 0.5 MPa for 30 minutes, and then left at normal pressure, 23° C. and 50% RH for 24 hours.
Then, under the conditions described above, the resin plate side was irradiated with active energy rays to cure the machinability improving layer, and then stored under high temperature and high humidity conditions of 85° C. and 85% RH for 500 hours.
After that, lifting and peeling at the interface between the machinability-enhancing layer and the adherend was visually confirmed, and the durability was evaluated according to the following criteria. Table 2 shows the results.
(double-circle): Neither air bubbles nor floating peeling can be confirmed.
◯: Although minute air bubbles are slightly generated, no large air bubbles or peeling can be confirmed.
Δ: Moderate air bubbles are generated, and large air bubbles and peeling are slightly observed.
x: Large air bubbles or floating peeling can be remarkably confirmed.

[Examples 2 to 9, Comparative Examples 1 to 4]
Composition and molecular weight of (meth)acrylic acid ester copolymer as main agent (A), type and amount of thermosetting component (B), type and amount of active energy ray-curable component (C), photopolymerization A film with improved machinability was obtained and machined in the same manner as in Example 1, except that the blending amount of the initiator (D) and the blending amount of the silane coupling agent (E) were changed as shown in Table 1. The property-enhancing film was evaluated. Table 2 shows the results obtained.

As described in detail above, according to the machinability-improving film of the present invention, the storage elastic modulus (M2) of the machinability-improving layer after being attached to a predetermined resin plate and further irradiated with active energy rays is By setting the value to a predetermined value, good machinability can be obtained even when the machinability improving layer is cut at the same time while the resin plate is included, using a mechanical processing device. rice field.
Further, according to the machinability-improving film of the present invention, by setting the adhesion (P2) of the machinability-improving layer after irradiation with active energy rays to a predetermined value, good durability can be obtained. became.

Then, a machinability-improving film provided with such a machinability-improving layer, a laminate including such a machinability-improving layer (resin plate to which the machinability-improving film is attached), and such a machine It has become possible to provide an efficient method of using the workability-enhancing film.
Therefore, the machinability-improving film of the present invention is expected to contribute to production efficiency and quality improvement in touch panels, liquid crystal display devices, and the like.

10, 10': Laminate 12: Resin plate 13: Resin layer derived from a composition for forming a machinability-improving layer 14: Machinability-improving layer 14': Machinability-improving layer 16 after curing : Predetermined base material (functional film, etc.)
16': Predetermined base material (release film, etc.)
18, 18': Machinability-enhancing film

Claims (9)

A machine equipped with an active energy ray-curable machinability-enhancing layer laminated on a functional film or release film as a predetermined substrate, which is attached to a resin plate having a thickness in the range of 200 to 10,000 μm. A processability improving film,
The storage modulus of the machinability-enhancing layer attached to the resin plate after irradiation with an active energy ray is 0.2 MPa or more,
A machinability-improving film characterized by having an adhesive strength of 10 N/25 mm or more after being irradiated with an active energy ray. 2. The machinability-improving film according to claim 1 , wherein the machinability-improving layer has a gel fraction of 60% or more after irradiation with active energy rays. 3. The machinability-improving film according to claim 1 , wherein the machinability-improving layer has a storage elastic modulus of 0.01 to 1 MPa before irradiation with active energy rays. The machining according to any one of claims 1 to 3 , wherein the storage modulus of the machinability-improving layer after irradiation with active energy rays is set to a value within the range of 0.2 to 5 MPa. performance-enhancing film. M2/M1×100, where M1 is the storage modulus of the machinability-improving layer before irradiation with active energy rays, and M2 is the storage modulus of the machinability-improving layer after irradiation with active energy rays. The machinability-improving film according to any one of claims 1 to 4 , wherein the numerical value represented by is within the range of 320 to 30000%. The machinability-improving film according to any one of claims 1 to 5 , wherein the machinability-improving layer has a thickness in the range of 3 to 40 µm. A laminate comprising the machinability-enhancing film according to any one of claims 1 to 6 attached to a resin plate. 8. The laminate according to claim 7 , wherein the resin plate is an optical resin plate. A method of using the machinability-improving film according to any one of claims 1 to 6 , comprising the following steps (1) to (4).
(1) A machine provided with an active energy ray-curable machinability-enhancing layer by applying a composition containing an active energy ray-curable component to the surface of a functional film as a predetermined substrate and heat-treating it. (2) Step of attaching the machinability-improving film to a resin plate (3) Irradiating an active energy ray from the side of the resin plate or a predetermined base material to form a film in the machinability-improving layer Step (4): Curing the active energy ray-curable component to form a cured machinability-improving layer; process

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