JP2020147640A - Machinability improvement film, laminate, and method for using machinability improvement film - Google Patents

Abstract

To provide a machinability improvement film capable of obtaining excellent machinability and durability by bonding a resin plate, a resin film and the like through a machinability improvement layer.SOLUTION: A machinability improvement film has a base material, and a machinability improvement layer containing an active energy ray-curable component and a crosslinkable component, in which the machinability improvement layer in a state of being stuck to a resin plate has an adhesive force (P1) before irradiation with active energy rays of 1 N/25 mm or more and has an adhesive force (P2) after irradiation with the active energy rays of 10 N/25 mm or more, and a gel fraction of the machinability improvement layer after irradiation with the active energy rays is 75% or more.SELECTED DRAWING: Figure 1

Description

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 a laminate having excellent machinability and durability, which are used in manufacturing a touch panel, a liquid crystal display device, and the like, and a method of using such a machinability-improving film.

Conventionally, a touch panel has been proposed for the purpose of suppressing the generation of interference fringes due to light interference and allowing the decorative film to be easily replaced (see, for example, Patent Document 1).
More specifically, it is a touch panel having an operation area that accepts touch input and a non-operation area that does not accept touch input, and that the lower surface of the decorative film corresponding to the operation area has irregularities. It is a featured touch panel device.

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

Furthermore, an optical member has been proposed in which the adhesive does not easily squeeze out during punching, the adhesive does not squeeze out on the cut surface, and adhesive contamination and adhesive chipping do not easily occur during handling (see, for example, Patent Document 3). ).
More specifically, it is an optical member in which the area of the pressure-sensitive adhesive that adheres to a portion other than the pressure-sensitive adhesive on the cut surface when punched is 20% or less of the area of the pressure-sensitive adhesive layer.

JP-A-2018-5698 (Claims, etc.) WO2013-61938 (Claims, etc.) Japanese Unexamined Patent Publication No. 2001-235626 (Claims, etc.)

However, the touch panel device disclosed in Patent Document 1 includes a predetermined exterior unit (sheet metal / adhesive layer / decorative film), and in such an exterior unit, the sheet metal and the adhesive layer are each processed into a predetermined shape. After that, it is laminated and manufactured. Therefore, in order to obtain the exterior unit, it is a drawback that there are many manufacturing processes.
Moreover, 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 (for example, 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 the occurrence of floating or peeling at the adhesive interface, resulting in poor durability.

Further, the adhesive sheet disclosed in Patent Document 2 considers only the adhesion between a pair of optical members having irregularities, and the adhesive sheet is sandwiched between the optical members and cut into a predetermined shape. Until then, I didn't consider anything.
Therefore, since no consideration was given to the value of the gel fraction of the pressure-sensitive adhesive layer, there was also a problem that the cutability of the pressure-sensitive adhesive sheet was poor.

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

Therefore, the present inventors have made diligent efforts in view of the above circumstances to obtain a machinability-improving film having a base material and an active energy ray-curable machinability-improving layer, and an active energy ray. By setting the gel fraction (G1) of the machinability improving layer to a value equal to or higher than a predetermined value after irradiation, a function that is one of the base materials in a state of including a resin plate by using a cutting device or the like. It was found that good machinability and the like can be obtained even when the sex film and the like and the machinability improving layer are cut.
Further, the adhesive strength (P1) of the machinability improving layer before irradiation with active energy rays is set to a predetermined value or more, and the adhesive strength (P2) of the machinability improving layer after irradiation with active energy rays is set to a predetermined value or more. As a result, it has been found that good durability can be obtained, and it has been found that the problem of durability can be solved in addition to the above-mentioned problem of machinability, and the present invention has been completed.
That is, the present invention is a machine that can obtain excellent machining processability (cuttability) and durability when a base material is simultaneously machined (cutting process, etc.) together with a resin plate such as a touch panel or a liquid crystal display device. It is an object of the present invention to provide a workability improving film, 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.

According to the present invention, it is composed of a base material and an active energy ray-curable machine-workable improving layer containing a reactant of an active energy ray-curable component and a crosslinkable component, and has an adhesive force before irradiation with active energy rays. (P1) is set to a value of 1N / 25 mm or more.
At the same time, the adhesive strength (P2) after irradiation with active energy rays is set to a value of 10 N / 25 mm or more, and the gel fraction (G1) of the machinability improving layer after irradiation with active energy rays is set to a value of 75% or more. Provided is a machinability-improving film, which can solve the above-mentioned problems.
That is, the machinability-improving film is formed in this way, the adhesive strength (P1) before irradiation with the active energy rays is set to a predetermined value or more, and the gel fraction of the machinability-improving layer after irradiation with the active energy rays. By setting (G1) to a value equal to or higher than a predetermined value, even when the machinability-improving film is cut at the same time with the resin plate included, between the machinability-improving film and the resin plate. The boundary surface is extremely clear, and good machinability can be obtained.
Further, by setting the adhesive strength (P2) after irradiation with active energy rays to a predetermined value or more, good durability is obtained when a machinability improving layer is attached to a resin plate such as a touch panel or a liquid crystal display device. Can also be obtained.

Further, in constructing the mechanizable property improving film of the present invention, the reactant of the crosslinkable component is a (meth) acrylic acid ester copolymer derived from a reactive functional group-containing monomer and a (meth) acrylic acid alkyl ester monomer. It is preferable that it is a reaction product of
By constructing the reactant of the crosslinkable component in this way, good reactivity can be maintained, and it becomes easy to obtain the cohesive force of the machinability improving layer.

Further, in constructing the machinability-improving film of the present invention, it is preferable that the reactive functional group-containing monomer is a hydroxyl group-containing monomer or a carboxy group-containing monomer.
By having the reactive functional group-containing monomer as described above, the reactivity with the crosslinkable component can be made excellent, and a good crosslinked structure can be easily formed.
As a result, the obtained machinability improving layer has a relatively high film strength and has good machinability.

Further, another aspect of the present invention is a laminate characterized in that any of the above-mentioned machinability-improving films is attached to a resin plate.
If it is a laminate containing such a resin plate and a machinability improving film, various functional films used in various devices are accurately machined (cut) together with the resin plate through the machinability improving layer. It can be easily produced as a laminate such as a functional film with a resin plate by processing).

Further, in constructing the laminate of the present invention, it is preferable that the resin plate is an optical resin plate.
In the case of a laminate containing such an optical resin plate, various functional films and the like used for the optical equipment such as a touch panel and a liquid crystal display device are accurately machined (cut) together with the optical resin plate. It can be processed) and manufactured as a functional film or the like with an optical resin plate via a machinability improving layer.

Further, another aspect of the present invention is a method of using any of the above-mentioned machinability-improving films, which comprises the following steps (1) to (3). How to use.
(1) Step of attaching the machinability improving film to the resin plate (2) Step of irradiating the active energy ray to cure the active energy ray curable component (3) Lamination including the machinability improving layer and the resin plate The process of applying a predetermined machining process to the body By using the machinability improving film in this way, when manufacturing a resin plate with a functional film in a touch panel, a liquid crystal display device, etc., a cutting device When the resin plate and the functional film are machined through the machinability improving layer using a machining apparatus such as the above, the interface between the machiningability improving film and the resin plate is extremely clear. Good machinability (cutability, durability, etc.) can be obtained.

1 (a) to 1 (b) are views provided for explaining each configuration example of a laminate made of a machinability-improving film. 2 (a) to 2 (e) are views provided for explaining a method for producing a machinability-improving film including a heat-crosslinking step and a method for producing a laminate using the machinability-improving film. .. 3 (a) to 3 (f) are views provided for explaining a process of producing and a process of using a laminate made of a machinability-improving film using a functional film as a base material (No. 1). ). 4 (a) to 4 (f) are views provided for explaining a process of producing and a process of using another laminate made of a machinability-improving film using a release film as a base material (FIGS. 4 (a) to 4 (f)). Part 2).

[First Embodiment]
As illustrated in FIGS. 1 (a) to 1 (b), the first embodiment of the present invention includes an active energy ray-curable machinability improving layer 14 and a base material to be attached to the resin plate 12. A machinability-improving film 18 comprising (functional film or the like) 16.
The adhesive force (P1) of the machinability improving layer 14 laminated on the resin plate 12 before irradiation with active energy rays is a value of 1N / 25 mm or more, and the adhesive force after irradiation with active energy rays. (P2) is a value of 10 N / 25 mm or more, and the gel fraction of the machinability improving layer 14'after irradiation with active energy rays is set to a value of 75% or more. It is 18.
Hereinafter, the machinability improving film 18 of the first embodiment will be specifically described for each constituent requirement with reference to the drawings as appropriate.
Note that FIG. 1A illustrates an embodiment of a laminated body 10 composed of a resin plate 12 formed by laminating a machinability improving film 18, and FIG. 1B illustrates another laminated body. An example of a touch panel (however, electrical wiring and the like is omitted) having a predetermined space 14a as a part of the machinability improving layer 14 is shown in one aspect of 10.

1. 1. Types of Resin Plate (1) The type of the resin plate 12 shown in FIG. 1 (a) and the like is not particularly limited, but a known transparent or translucent resin plate is used because of its good machinability. It is preferable to use it.

Examples of such a resin plate include polyester resin plates such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polyethylene resin plates, polypropylene resin plates, diacetyl cellulose resin plates, triacetyl cellulose resin plates, and acetyl cellulose 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 Examples thereof include a resin plate, a polyether sulfone resin plate, a polyetherimide resin plate, a polyimide resin plate, a fluororesin plate, a polyamide resin plate, an acrylic resin plate, a norbornene-based resin plate, and a cycloolefin resin plate.

Among these, since it has good optical properties and heat resistance, and is also excellent in dimensional stability, it is a polyester resin plate, a polycarbonate resin plate, a polymethylpentene resin plate, a polysulfone resin plate, an acrylic resin plate, and a polyether. More preferably, it is at least one of an ether ketone resin plate, a polyimide resin plate, a norbornene-based resin plate, and a cycloolefin resin plate.
In addition, since it is excellent in transparency, mechanical strength, flexibility, workability, weather resistance, and economy, it is particularly preferable to use an acrylic resin plate (MMA resin plate, etc.) or a polycarbonate resin plate. More preferred.

(2) Thickness It is preferable that the thickness of the resin plate 12 shown in FIG. 1A or the like is usually set to a value within the range of 200 to 10000 μm.
The reason for this is that if the thickness of the resin plate 12 is less than 200 μm, the strength of the resin plate 12 may decrease, or the arrangement and fixing property of the touch panel or the like including the resin plate 12 may decrease. is there.
On the other hand, when the thickness of the resin plate 12 exceeds 10000 μm, the resin plate 12 and the functional film as the base material 16 are simultaneously machined via the machinability improving layers 14 and 14'. This is because it may be difficult to do.
Therefore, the thickness of the resin plate 12 is more preferably set to a value in the range of 500 to 5000 μm, and further preferably set to a value in the range of 700 to 2000 μm.

(3) Optical Characteristics Regarding the optical characteristics of the resin plate 12, it is preferable that the resin plate 12 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 12 is excessively low, the yield may be significantly reduced, or the types of constituent materials that can be used may be excessively limited.
Therefore, the lower limit of the visible light transmittance of the resin plate 12 is preferably 60% or more, more preferably 75% or more, and further preferably 85% or more.
On the other hand, the upper limit of the visible light transmittance of the resin plate 12 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 the value to.

(4) Additives In the resin plate 12, in order to improve durability, physical properties, mechanical properties, etc., antioxidants, hydrolysis inhibitors, ultraviolet absorbers, inorganic fillers, organic fillers, inorganic fibers, organic fibers, conductivity It is also preferable to add at least one known additive such as a physical material, an electrically insulating material, a metal ion trapping agent, a lightening agent, a filler, a polishing agent, a coloring agent, and a viscosity modifier.
When these known additives are blended in the resin plate, the blending amount is usually 0 with respect to the total amount (100% by weight) of the resin plate 12, although it depends on the type of the additive. The value is preferably in the range of 1 to 30% by weight, more preferably in the range of 0.5 to 20% by weight, and preferably in the range of 1 to 10% by weight. More preferred.

2. 2. Machinability Improvement Layer The machinability improvement layer 14 in the present embodiment includes a (meth) acrylic acid ester copolymer as a main agent (A), a crosslinkable component (B), and an active energy ray-curable component (C). ) Is an essential component, and the resin layer 13 (sometimes referred to as a precursor) derived from the composition for forming the machinability improving layer 14 can be obtained by heat-crosslinking by heat treatment.
That is, the machinability improving layer 14 is not a reaction product having a crosslinked structure in which a (meth) acrylic acid ester copolymer as a main agent (A) and a crosslinkable component (B) are formed by heat. It is composed of a curing active energy ray-curable component (C). The active energy ray-curable component (C) is crosslinked to the machinability improving layer 14 by irradiation with active energy rays to form a crosslinked structure intricately entwined with the reactants, whereby after curing. The machinability improving layer 14'can be obtained.

In the present specification, "(meth) acrylate" shall mean both acrylate and methacrylate, and the same shall apply hereinafter including other similar terms.
Hereinafter, the components (A) to (E) and the like constituting the machinability improving layer 14 and its precursor will be specifically described.

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

When the main agent (A) is a (meth) acrylic acid ester copolymer, a monomer having a reactive group in the molecule that reacts with the crosslinkable component (B) as a monomer unit constituting the copolymer (A). (Reactive functional group-containing monomer) and (meth) acrylic acid alkyl ester are preferably contained.
The reason for this is that the reactive group derived from the reactive group-containing monomer reacts with the crosslinkable component (B) to form a crosslinked structure (three-dimensional network structure), whereby the desired storage elastic modulus and gel fraction are formed. This is because it is possible to obtain the machineability improving layer 14 having a relatively high film strength by easily satisfying.

(1) -1 Monomer 1 (reactive functional group-containing monomer)
Examples of the reactive group-containing monomer constituting a part of the (meth) acrylic acid ester polymer as the main agent (A) include a monomer having a hydroxyl group in the molecule (hereinafter, may be referred to as a hydroxyl group-containing monomer) and a molecule. Examples thereof include a monomer having a carboxy group inside (hereinafter, may be referred to as a carboxy group-containing monomer), a monomer having an amino group in the molecule (hereinafter, may be referred to as an amino group-containing monomer), and the like.
Among these, even if the weight average molecular weight of the hydroxyl group-containing monomer and the (meth) acrylic acid ester copolymer is relatively low from the viewpoint of excellent reactivity with the crosslinkable component (B) and less adverse effect on the adherend. A carboxy group-containing monomer is preferable from the viewpoint that the adhesive force and the gel fraction can easily satisfy the desired values by exhibiting the desired cohesive force.

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

Further, the blending amount of the hydroxyl group-containing monomer as a monomer unit is preferably 1% by weight or more, and 10% by weight or more, based on the total amount of the monomers (100% by weight, hereinafter the same). Is more preferable, and 15% by weight or more is more preferable, and 20% by weight or more is preferable from the viewpoint that the gel fraction increase rate and the like can be set to a desired value.
Further, the blending amount of the hydroxyl group-containing monomer is preferably 50% by weight or less, more preferably 40% by weight or less, still 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 as a monomer unit in a predetermined range, it becomes easier to react favorably with the crosslinkable component (B), and a good crosslinked structure is formed. ..
As a result, the obtained machinability improving layer 14 can easily satisfy the desired storage elastic modulus and gel fraction, so that the film strength is relatively high and the machinability improving layer 14 has good machinability.

Examples of the carboxy group-containing monomer include 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 group and the crosslinkable component (B) in the obtained (meth) acrylic acid ester copolymer and the copolymerizability with other monomers. These may be used alone or in combination of two or more.
When a carboxy group-containing monomer is contained as the monomer unit, the (meth) acrylic acid ester copolymer preferably contains the carboxy group-containing monomer in an amount of 1% by weight or more based on the total amount of the monomer. It is particularly preferably contained in an amount of 8% by weight or more, and further preferably contained in an amount of 8% by weight or more.
Further, the (meth) acrylic acid ester copolymer preferably contains a carboxy group-containing monomer in an amount of 30% by weight or less, more preferably 20% by weight or less, as a monomer unit constituting the polymer. It is more preferably contained in an amount of 15% by weight or less.
That is, by containing the carboxy group-containing monomer as the monomer unit in a predetermined range, it becomes easy to react favorably with the crosslinkable component (B), and a good crosslinked structure is formed.
As a result, the obtained machinability improving layer 14 can easily satisfy the desired storage elastic modulus and gel fraction, and has good machinability.

Further, it is also preferable that the monomer unit contains a trace amount of the carboxy group-containing monomer or does not contain it at all.
The reason for this is that since the carboxy group is an acid component, the fact that the carboxy group-containing monomer is not contained causes problems with the acid to be applied to the adhesive, for example, a transparent conductive film such as tin-doped indium oxide (ITO). This is because even when a metal film or the like is present, those defects (corrosion, change in resistance value, etc.) due to acid can be suppressed.
However, it is permissible to contain a predetermined amount of the carboxy group-containing monomer so as not to cause such a problem.
Specifically, in the (meth) acrylic acid ester copolymer, the amount of the carboxy group-containing monomer as a monomer unit is 5% by weight or less, preferably 1% by weight or less, and more preferably 0.1% by weight or less. It is permissible to contain.

Examples of the amino group-containing monomer include aminoethyl (meth) acrylate and n-butylaminoethyl (meth) acrylate.
These may be used alone or in combination of two or more.
When an amino group-containing monomer is contained as the monomer unit, the (meth) acrylic acid ester copolymer preferably contains the amino group-containing monomer in an amount of 1% by weight or more based on the total amount of the monomer. It is particularly preferably contained in an amount of 8% by weight or more, and further preferably contained in an amount of 8% by weight or more.
Further, the (meth) acrylic acid ester copolymer preferably contains an amino group-containing monomer in an amount of 30% by weight or less, more preferably 20% by weight or less, as a monomer unit constituting the polymer. It is more preferably contained in an amount of 15% by weight or less.
That is, by containing the amino group-containing monomer as the monomer unit in a predetermined range, it becomes easy to react favorably with the crosslinkable component (B), and a good crosslinked structure is formed.
As a result, the obtained machinability improving layer 14 can easily satisfy the desired storage elastic modulus and gel fraction, and has good machinability.

(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.
As a result, the machinability improving layer 14 can exhibit preferable adhesiveness.
Further, the (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms of the alkyl group preferably has a linear or branched chain structure from the viewpoint of exhibiting more preferable tackiness.

As the (meth) acrylic acid alkyl ester having 1 to 20 carbon atoms of the alkyl group, the glass transition temperature (Tg) as a homopolymer is preferably less than 0 ° C. (hereinafter, may be referred to as low Tg alkyl acrylate). is there.).
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 14 can be further improved.

Here, examples of the low Tg alkyl acrylate include n-butyl acrylate (Tg-55 ° C.), n-octyl acrylate (Tg-65 ° C.), isooctyl acrylate (Tg-58 ° C.), and 2-acrylic acid. Ethylhexyl (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 (
At least one such as Tg-55 ° C.) and tridecylic methacrylate (Tg-40 ° C.) is preferably mentioned.
Among these, from the viewpoint of more effectively improving the adhesiveness, the homopolymer Tg of the low Tg alkyl acrylate is more preferably −25 ° C. or lower, and more preferably −50 ° C. or lower. More preferably.
Specifically, n-butyl acrylate and 2-ethylhexyl acrylate are particularly preferable.

Further, the (meth) acrylic acid ester copolymer preferably contains a low Tg alkyl acrylate as a lower limit value of 30% by weight or more, particularly 40% by weight or more, as a monomer unit constituting the polymer. Is more preferable, and it is further preferable that the content is 50% by weight or more.
The reason for this is that when such a low Tg alkyl acrylate is blended, the adhesiveness of the obtained machinability improving layer 14 can be satisfactorily improved, and the adhesiveness to the resin plate 12 is further improved. Because it can be done.
Further, the (meth) acrylic acid ester copolymer preferably contains low Tg alkyl acrylate as a monomer unit constituting the polymer in an upper limit of 99% by weight or less, and particularly 90% by weight or less. It is more preferable that the content is 80% by weight or less.
The reason for this is that when such a low Tg alkyl acrylate is blended, a suitable amount of other monomer components (particularly reactive functional group-containing monomers) can be introduced into the (meth) acrylic acid ester polymer. is there.

Further, the (meth) acrylic acid ester polymer is a monomer having a glass transition temperature (Tg) of more than 0 ° C. as a homopolymer (hereinafter, may be referred to as high Tg alkyl acrylate) constituting the polymer. It is also preferable to use them together.
The reason for this is that it is possible to impart an appropriate cohesive force to the obtained machinability improving layer 14, easily satisfy the desired storage elastic modulus and gel fraction, and improve machinability.

However, the high Tg alkyl acrylate described here excludes the alicyclic structure-containing monomer and the nitrogen-containing monomer 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.), and n-butyl methacrylate (Tg: ° C.). 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. At least one of the acrylic monomers, vinyl acetate (Tg: 32 ° C.), styrene (Tg: 30 ° C.) and the like can be mentioned.
Among these, methyl methacrylate is particularly suitable as a high Tg alkyl acrylate because it can impart appropriate cohesiveness to the machinability improving layer 14 and easily develop a desired storage elastic modulus and gel fraction. Is preferable.

That is, when the (meth) acrylic acid ester polymer contains the high Tg alkyl acrylate as the monomer unit constituting the polymer, the high Tg alkyl acrylate is added to 1% by weight based on the total amount of the monomer components. It is more preferable to contain more than this, and it is more preferable to contain 3% by weight or more.
Further, the (meth) acrylic acid ester polymer preferably contains the above-mentioned high Tg alkyl acrylate in an amount of 20% by weight or less, more preferably 12% by weight or less, as a monomer unit constituting the polymer. It is more preferably contained in an amount of 8% by weight or less.
The reason for this is that the machinability improving layer 14 obtained by using the high Tg alkyl acrylate in combination with the low Tg alkyl acrylate in the above amount exhibits suitable adhesiveness and cohesive force, and is adhesive. This is because the force and the gel fraction can easily satisfy the desired values and the desired durability can be easily satisfied.

(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 (alicyclic structure-containing monomer) in the molecule as a monomer unit constituting the copolymer. Is preferable.
The reason for this is that the alicyclic structure-containing monomer is bulky due to its molecular structure, and it is presumed that the presence of this in the copolymer widens the distance between the polymers. As a result, the obtained machinability improving layer 14 can be made excellent in flexibility.
Therefore, when the (meth) acrylic acid ester polymer contains an alicyclic structure-containing monomer as a monomer unit, the machinability improving layer 14 obtained by cross-linking the composition easily develops desired adhesiveness. Therefore, the adhesiveness to the resin plate 12 is excellent.

Further, the carbon ring having an alicyclic structure in the alicyclic structure-containing monomer may have a saturated structure or may have an unsaturated bond as a part.
Further, such an alicyclic structure may be a monocyclic alicyclic structure or a polycyclic alicyclic structure such as bicyclic or tricyclic.
From the viewpoint of widening the distance between the polymers in the obtained (meth) acrylic acid ester copolymer and effectively exerting the flexibility of the machinability improving layer 14, the above alicyclic structure is a polycyclic fat. It preferably has a cyclic structure (polycyclic structure).
Further, since the compatibility between the (meth) acrylic acid ester copolymer and other components is good, the polycyclic structure is particularly preferably bicyclic to tetracyclic.

Further, from the viewpoint of effectively exerting the flexibility of the pressure-sensitive adhesive as described above, the number of carbon atoms in the alicyclic structure (meaning the total number of carbon atoms in the portion forming the ring, and the plurality of rings are independent. When present, it means the total number of carbon atoms) is usually preferably 5 or more, and more preferably 7 or more.
On the other hand, the upper limit of the number of carbon atoms in the alicyclic structure is not particularly limited, but from the viewpoint of compatibility as described above, it is preferably 15 or less, and more preferably 10 or less.

Therefore, examples of the alicyclic structure contained in the alicyclic structure-containing monomer include a cyclohexyl skeleton, a dicyclopentadiene skeleton, an adamantan skeleton, an isobornyl skeleton, and a cycloalkane skeleton (cycloheptane skeleton, cyclooctane skeleton, cyclononan skeleton, cyclodecan). At least one of skeleton, cycloundecane skeleton, cyclododecane skeleton, etc.), cycloalkene skeleton (cycloheptene skeleton, cyclooctene skeleton, etc.), norbornene skeleton, norbornadiene skeleton, Cuban skeleton, basketane skeleton, Hausan skeleton, spiro skeleton and the like can be mentioned.

Among these, from the viewpoint of obtaining more excellent durability, the dicyclopentadiene skeleton (alicyclic structure has 10 carbon atoms), the adamantane skeleton (alicyclic structure has 10 carbon atoms), or the isobornyl skeleton (fat). The one containing a cyclic structure having 7) carbon atoms is preferable, and the one containing an isobornyl skeleton is more preferable.
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, isopentenyl (meth) acrylate, dicyclopentenyl (meth) acrylate, (meth) acrylate. At least one such as dicyclopentenyloxyethyl and the like can be mentioned.
Moreover, among these, dicyclopentanyl (meth) acrylate, adamantyl (meth) acrylate or isobornyl (meth) acrylate is preferable, and isobornyl (meth) acrylate is preferable from the viewpoint of obtaining more excellent durability. More preferably, isobornyl acrylate is particularly preferable.

Further, it is preferable that the (meth) acrylic acid ester copolymer contains 1% by weight or more of the alicyclic structure-containing monomer with respect to the total amount of the monomers as the 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 an alicyclic structure-containing monomer in an amount of 40% by weight or less, and preferably 30% by weight or less, as a monomer unit constituting the copolymer. More preferably, it is contained in an amount of 24% by weight or less, and from the viewpoint of exhibiting the desired adhesive strength, gel fraction and storage elasticity and making the durability more excellent, it is contained in an amount of 18% by weight or less. Is particularly preferable.
When the content of the alicyclic structure-containing monomer is within the above range, the flexibility of the obtained machinability improving layer 14 is improved, and the adhesiveness to the resin plate 12 is more excellent. Therefore, it becomes easier to satisfy the desired values of adhesive strength and storage elastic modulus, 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 the molecule (nitrogen atom-containing monomer) as a monomer unit constituting the copolymer.
The amino group-containing monomer exemplified as the reactive group-containing monomer is excluded from the nitrogen atom-containing monomer. By allowing the nitrogen atom-containing monomer to be present in the copolymer as a constituent unit, the reaction between the acrylic ester copolymer and the crosslinkable component (B) can be promoted, and the machineability improving layer 14 becomes polar. It can be imparted to increase the cohesive force of the mechanicability improving layer 14, and facilitate the development of desired adhesive force, gel fraction and storage elasticity.

Examples of the nitrogen atom-containing monomer include a monomer having a tertiary amino group, a monomer having an amide group, and a monomer having a nitrogen-containing heterocycle. Among these, a monomer having a nitrogen-containing heterocycle is preferable.
Examples of the monomer having such a nitrogen-containing heterocycle include N- (meth) acryloylmorpholine, N-vinyl-2-pyrrolidone, N- (meth) acryloylpyrrolidone, N- (meth) acryloylpiperidin, and N- (meth). ) Acryloylpyrrolidine, N- (meth) acryloylazilysin, aziridinylethyl (meth) acrylate, 2-vinylpyridine, 4-vinylpyridine, 2-vinylpyrazine, 1-vinylimidazole, N-vinylcarbazole, N-vinylphthalimide And at least one of them.
Among these, N- (meth) acryloyl morpholin is preferable, and N-acryloyl morpholin is more preferable, from the viewpoint of obtaining more excellent adhesive strength.

Examples of the nitrogen atom-containing monomer other than the above-mentioned monomer having a nitrogen-containing heterocycle include (meth) acrylamide, N-methyl (meth) acrylamide, N-methylol (meth) acrylamide, and N-tert-butyl (meth). ) 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.

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, based on 4% by weight, based on the total amount of the monomer components. It is more preferable to contain% or more.
Further, the (meth) acrylic acid ester copolymer preferably contains a nitrogen atom-containing monomer in an amount of 40% by weight or less, more preferably 30% by weight or less, as a monomer unit constituting the copolymer. The content is more preferably 20% by weight or less, and the content is particularly preferably 10% by weight or less because the desired adhesive strength, gel fraction and storage elasticity are exhibited to further improve the durability. preferable.
When the content of the nitrogen atom-containing monomer is within the above range, the cohesive force of the obtained machinability improving layer 14 is effectively improved, and the desired adhesive force, gel fraction and storage elastic modulus are effectively improved. This is because it becomes easier to exert the above and the durability becomes excellent.

(1) -5 Monomer 5 (Other monomers)
If necessary, the (meth) acrylic acid ester copolymer as the main agent (A) may contain other monomers different from the above-mentioned monomer components as the monomer unit constituting the copolymer.
As such other monomers, a monomer containing no functional group having reactivity is preferable.
That is, for example, (meth) acrylic acid alkoxyalkyl ester such as methoxyethyl (meth) acrylate and ethoxyethyl (meth) acrylate, vinyl acetate, styrene and the like can be mentioned. 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 precursor of the machinability improving layer 14 is a (meth) acrylic acid ester copolymer, the weight average molecular weight (Mw) is 50,000 to The value is preferably in the range of 2.5 million.
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 lowered, and the (meth) acrylic acid ester copolymer is peeled off from the resin plate 12 or the adhesiveness is remarkably lowered. Because there is.
On the other hand, if the weight average molecular weight of the (meth) acrylic acid ester copolymer exceeds 2.5 million, it may be difficult to handle or the adhesiveness to the resin plate 12 may be deteriorated.
Therefore, the weight average molecular weight of the (meth) acrylic acid ester copolymer is more preferably set to a value in the range of 100,000 to 1.8 million, further preferably set to a value in the range of 300 to 1,000,000, and 40 to 80. Most preferably, the value is in the range of 10,000.
The weight average molecular weight of the main agent of the machinability improving layer 14 can be determined by GPC (gel permeation chromatography) in comparison with a calibration curve for standard polystyrene particles prepared in advance.

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

Examples of the polymerization initiator when 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, examples of the azo compound include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), and 1,1'-azobis (cyclohexane1-). Carbonitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'-azobis (2- Methylpropionate), 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 the organic peroxide include benzoyl peroxide, t-butylperbenzoate, cumenehydroperoxide, diisopropylperoxydicarbonate, di-n-propylperoxydicarbonate, and di (2-ethoxyethyl). Examples thereof include peroxydicarbonate, t-butylperoxyneodecanoate, t-butylperoxyvivarate, (3,5,5-trimethylhexanoyl) peroxide, dipropionyl peroxide, and diacetyl peroxide.
In the above polymerization step, the weight average molecular weight of the obtained polymer can be adjusted to a desired value by adding a chain transfer agent such as 2-mercaptoethanol.

(2) Crosslinkable component (B)
When the composition containing the crosslinkable component (B) is heated, the crosslinkable component (B) undergoes a crosslink reaction with the (meth) acrylic acid ester copolymer as the main agent (A) to form a crosslinked structure (three-dimensional network). Structure) is formed. As a result, the machinability improving layer 14 having a relatively high film strength can be obtained.
The type of the crosslinkable component (B) may be one that reacts with the main agent (A) (for example, a (meth) acrylic acid ester copolymer or the like), and preferably the main agent (A) of the composition. ) Shall react with a reactive group (for example, a hydroxyl group, a carboxy group, etc.).
Further, the crosslinkable component (B) may be one that reacts with heat or one that reacts with active energy rays such as ultraviolet rays and electron beams, but the obtained mechanicability improving layer may be used. From the viewpoint of facilitating the development of the desired adhesive strength and gel fraction, 14 is preferably a heat-crosslinkable component that undergoes a heat-crosslinking reaction with the main agent (A) (for example, a (meth) acrylic acid ester copolymer or the like). ..
Examples of the heat-crosslinkable component that undergoes a heat-crosslinking reaction with the main agent (A) (for example, a (meth) acrylic acid ester copolymer, etc.) include an isocyanate-based crosslinker, an epoxy-based crosslinker, and an epoxy-based crosslinker. Amin-based cross-linking agent, melamine-based cross-linking agent, aziridine-based cross-linking agent, hydrazine-based cross-linking agent, aldehyde-based cross-linking agent, oxazoline-based cross-linking agent, metal alkoxide-based cross-linking agent, metal chelate-based cross-linking agent, metal salt-based cross-linking agent, ammonium salt At least one of the system cross-linking agents and the like can be mentioned.
The type of the crosslinkable component (B) may be selected according to the reactivity of the reactive group contained in the main agent (A).
For example, when the reactive group of the main agent (A) is a hydroxyl group, it is preferable to add an isocyanate-based cross-linking agent having excellent reactivity with the hydroxyl group.
When the reactive group of the main agent (A) is a carboxy group, it is preferable to use an epoxy-based cross-linking agent having excellent reactivity with the carboxy group.
As the crosslinkable component (B), one type can be used alone, or two or more types can be used in combination.

Further, the isocyanate-based cross-linking agent preferably contains at least a polyisocyanate compound.
Here, examples of the polyisocyanate compound include aromatic polyisocyanates such as tolylene diisocyanate, diphenylmethane diisocyanate, and xylylene diisocyanate, aliphatic polyisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, and alicyclic type such as hydrogenated diphenylmethane diisocyanate. Polyisocyanates and their biuret and isocyanurates, as well as adducts, which are reactants with low molecular weight active hydrogen-containing compounds such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylolpropane, and castor oil. Can be mentioned. Among these, from the viewpoint of reactivity with a hydroxyl group, at least one of trimethylolpropane-modified aromatic polyisocyanate, particularly trimethylolpropane-modified tolylene diisocyanate and trimethylolpropane-modified xylene diisocyanate is preferable.

Examples of the epoxy-based cross-linking agent include 1,3-bis (N, N-diglycidyl aminomethyl) cyclohexane, N, N, N', N'-tetraglycidyl-m-xylylenediamine, and ethylene glycol di. At least one of glycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylpropan diglycidyl ether, diglycidyl aniline, diglycidyl amine and the like can be mentioned.
Among these, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane is particularly preferable from the viewpoint of reactivity with a carboxy group.

Further, the blending amount of the crosslinkable component (B) is preferably set to a value within the range of 0.05 to 10 parts by weight with respect to 100 parts by weight of the main agent (A).
The reason for this is that when the blending amount of the crosslinkable component (B) is less than 0.05 parts by weight, the reactivity with the hydroxyl group or carboxy group introduced into the main agent (A) is remarkably lowered. This is because the cohesive force of the machinability improving layer 14 cannot be obtained, and the adhesiveness may not be exhibited.
As a result, the machinability improving layer 14 may be peeled off from the resin plate 12 or the adhesiveness may be significantly reduced.
On the other hand, when the blending amount of the crosslinkable component (B) exceeds 10 parts by weight, the machinability improving layer 14 is obtained by excessively reacting with the hydroxyl group or carboxy group introduced into the main agent (A). The cohesive force of the material may become too high, and the adhesiveness may be significantly reduced.
Therefore, it is more preferable that the blending amount of the crosslinkable component (B) is in the range of 0.1 to 5 parts by weight with respect to 100 parts by weight of the main agent (A), and 0.3 to 1 part by weight. It is more preferable that the value is within the range.

(3) Active energy ray-curable component (C)
The machinability improving layer 14 in the present embodiment preferably contains an active energy ray-curable component (C).
When the active energy ray is irradiated after the machinability improving layer 14 is attached to the adherend (resin plate 12), the active energy ray is triggered by the cleavage of the photopolymerization initiator (D) described later. The polymerization of the curable component (C) is promoted.
It is presumed that the polymerized active energy ray-curable component (C) is entwined with a crosslinked structure (three-dimensional network structure) formed by crosslinking the main agent (A) and the crosslinkable component (B).
Therefore, the machinability improving layer 14'having such a higher-order structure can easily satisfy the desired adhesive strength, storage elastic modulus, and gel fraction, and is excellent in durability under high temperature and high humidity conditions. It becomes a thing.

Here, the active energy ray-curable component (C) is not particularly limited as long as it is a component that causes a curing reaction by irradiation with active energy rays and obtains the above effects.
Further, the active energy ray-curable component (C) may be any of a monomer, an oligomer or a polymer, or a mixture thereof.
Among these, a polyfunctional acrylate-based monomer having excellent compatibility with the main agent (A) and the like and having a weight average molecular weight of less than 1,000 is preferable.

More specifically, as the polyfunctional acrylate-based monomer having a weight average molecular weight of less than 1000, an acrylate-based monomer having 2 to 6 reactive functional groups is preferable.
Here, examples of the acrylate-based monomer having two reactive functional groups include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and neopentyl glycol di (meth). Acrylate, polyethylene glycol di (meth) acrylate, neopentyl glycol adipate di (meth) acrylate, neopentyl glycol di (meth) acrylate of hydroxypivalate, dicyclopentanyldi (meth) acrylate, caprolactone-modified dicyclopentenyldi (meth) ) Acrylate, ethylene oxide modified di (meth) acrylate, di (acryloxyethyl) isocyanurate, allylated cyclohexyl di (meth) acrylate, ethoxylated bisphenol A diacrylate, 9,9-bis [4- (2-acryloyl) Oxyethoxy) phenyl] fluorene and the like can be mentioned at least one.

Examples of the acrylate-based monomer 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 and the like can be mentioned. ..

Further, examples of the acrylate-based monomer 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 6 reactive functional groups include at least one such as dipentaerythritol hexa (meth) acrylate and caprolactone-modified dipentaerythritol hexa (meth) acrylate.

Among these, an acrylate-based monomer having 3 to 6 reactive functional groups is particularly preferable from the viewpoint of durability of the machinability improving layer 14.
Specifically, trimethylolpropane triacrylate, dipentaerythritol hexaacrylate, and ε-caprolactone-modified tris- (2- (meth) acryloxiethyl) isocyanurate are particularly preferable.

Further, 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 an acrylate-based oligomer include at least one such as polyester acrylate-based, epoxy acrylate-based, urethane acrylate-based, polyether acrylate-based, polybutadiene acrylate-based, and silicone acrylate-based.
The weight average molecular weight of such an acrylate-based oligomer is preferably 50,000 or less, more preferably 500 to 50,000, and even more preferably 3,000 to 40,000.

Further, as the active energy ray-curable component (C), it is also preferable to use an adduct acrylate-based polymer in which a group having a (meth) acryloyl group is introduced into a 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 is used as a part of the crosslinkable functional group of the copolymer. , (Meta) It can be obtained by reacting a compound having a group that reacts with an acryloyl group and a crosslinkable functional group.
The weight average molecular weight of the above-mentioned adduct acrylate polymer is preferably about 50,000 to 900,000, and more preferably about 100,000 to 500,000.

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

The blending amount of the active energy ray-curable component (C) is usually preferably set to a value within the range of 1 to 50 parts by weight with respect to 100 parts by weight of the main agent (A).
The reason for this is that when the blending amount of the active energy ray-curable component (C) is less than 1 part by weight, the reactivity becomes poor and it becomes difficult to develop the desired storage elastic modulus and gel fraction. This is because good machining processability may not be obtained.
On the other hand, when the blending amount of the active energy ray-curable component (C) exceeds 50 parts by weight, on the contrary, the reactivity cannot be controlled and it reacts excessively with the main agent (A), resulting in a dense crosslinked structure. This is because the adhesive strength may decrease and good durability may not be obtained.
Therefore, the lower limit of the blending 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, based on 100 parts by weight of the main agent (A). It is more preferably 10 parts by weight or more.
On the other hand, the upper limit of the blending 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) Photopolymerization initiator (D)
Since the active energy ray-curable component (C) can be efficiently cured by irradiation with active energy rays, it is preferable to contain a photopolymerization initiator (D) as desired.

Examples of such a photopolymerization initiator (D) include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, and 2,2-dimethoxy-2. -Phenylacetphenone, 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-Terrary butyl anthraquinone, 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 And at least one of them.

Among these, when ultraviolet rays are used as active energy rays, it is preferable to contain a photopolymerization initiator (D) having an absorption wavelength outside the ultraviolet absorption wavelength region, and among them, a longer wavelength side (380 nm or more) than the ultraviolet region. ) More preferably contains a photopolymerization initiator (D) having an absorption wavelength, and particularly 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 are deteriorated by 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 an ultraviolet absorbing ability (ultraviolet shielding member) into an electronic device.
In the case where the ultraviolet shielding member is incorporated in the electronic device and the ultraviolet rays are irradiated from the ultraviolet shielding member side in this way, the photopolymerization initiator (the photopolymerization initiator) having no absorption wavelength outside the ultraviolet absorption wavelength region in the mechanicability improving layer 14. When D) is used, the ultraviolet rays are shielded by the ultraviolet shielding member, and the mechanization improving layer 14 cannot be cured.
Conversely, in such a case, if a photopolymerization initiator (D) having an absorption wavelength outside the ultraviolet absorption wavelength region is used for the mechanization improving layer 14, a wavelength outside the ultraviolet absorption wavelength region can be used. This is because it can be sufficiently cured.

The blending amount of the photopolymerization initiator (D) is preferably in 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). The value is more preferably in the range of ~ 20 parts by weight, and further preferably in the range of 5 to 15 parts by weight.

(5) Silane coupling agent (E)
The composition for forming the machinability improving layer 14 further preferably contains a silane coupling agent (E).
This is because when the adherend contains a glass member or a resin member, the adhesion between the machinability improving layer 14 and the adherend is improved.
Therefore, the machinability improving layer 14 containing the silane coupling agent (E) is more excellent in durability under high temperature and high humidity conditions.

Here, as the type of the silane coupling agent (E), an organosilicon compound having at least one alkoxysilyl group in the molecule and having light transmittance is preferable.
Examples of such a silane coupling agent (E) include polymerizable unsaturated group-containing silicon compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, and methacrypropyltrimethoxysilane; 3-glycidoxypropyltrimethoxy. Silicon compounds having an epoxy structure such as silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropyldimethoxymethylsilane, etc. 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-isocyanuspropyltriethoxysilane, or at least one of these and alkyl such as methyltriethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane Examples thereof include a condensate with a group-containing silicon compound. These may be used individually by 1 type and may be used in combination of 2 or more type.

Further, it is preferable that the blending amount of the silane coupling agent (E) is usually in the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the main agent (A).
The reason for this is that if the blending amount of the silane coupling agent (E) is less than 0.01 parts by weight, it may be difficult to obtain the blending effect.
On the other hand, when the blending amount of the silane coupling agent (E) exceeds 5 parts by weight, the hydroxyl groups and carboxy groups introduced into the main agent (A) due to the silane coupling agent (E) This is because the crosslinkable component (B) may react excessively and the adhesiveness may be significantly reduced.
Therefore, the blending 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 is 0.2 to 1 part by weight. It is more preferable that the value is within the range of.

(6) Additives In addition to the above-mentioned silane coupling agent (E), inorganic fillers, organic fillers, inorganic fibers, and organic fibers are used in order to further improve the machinability and mechanical properties of the machinability improving layer 14. , Conductive material, electrically insulating material, metal ion trapping agent, lightening agent, thickener, filler, abrasive, colorant, antioxidant, hydrolysis inhibitor, ultraviolet absorber, etc. It is also preferable to add the additive of.
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). It is preferable, and it is more preferable that the value is in the range of 0.5 to 30% by weight.

(7) Thickness The thickness of the machinability improving layer 14 is preferably a value within the range of 3 to 40 μm.
The reason for this is that if the thickness of the mechanicability improving layer is less than 3 μm, the desired adhesiveness cannot be exhibited and the adhesiveness to the resin plate 12 tends to deteriorate.
On the other hand, when the thickness of the machinability improving layer 14 exceeds 40 μm, the machinability may deteriorate or the adhesive strength before and after irradiation with active energy rays may be adjusted to a value within a desired range. This is because it can be difficult.
Therefore, the thickness of the machinability improving layer 14 is more preferably set to a value in the range of 8 to 30 μm, and further preferably set to a value in the range of 10 to 20 μm.

3. 3. Base material The type of the base material 16 is not particularly limited, but is usually a resin film, and among them, a functional film and a release film are typical.

When the base material 16 is a functional film, the types thereof include a decorative film for a touch panel, a deflection film for a liquid crystal display device, a retardation film, a light diffusing film, an optical control film, an antiglare film, and a photocatalytic film. At least one of an ultraviolet shielding film, a heat insulating film, an antistatic film, a conductive film, a half mirror film, a hard coat film, a decorative film, a holographic film property and the like can be mentioned.
The various functional films described above have various functions (decorativeness, photopolarizing property, optical phase property, light diffusivity, light controllability) on the surface of PET film, PEN film, acrylic film, polycarbonate film, TAC film and the like. , Anti-glare, UV shielding, heat shielding, antistatic property, conductivity, half mirror property, hard coat property, decorative property, holographic property, etc.) are provided on the surface or inside. Is appropriately selected according to the purpose.

The thickness of the functional film as the base material 16 is determined in consideration of the application, light transmittance, and the like, but 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 significantly reduced.
On the other hand, if the thickness of the functional film exceeds 300 μm, the sensitivity may be lowered or the permeability of the active energy ray may be remarkably lowered when used for a touch panel or the like.
Therefore, the thickness of the functional film is more preferably set to a value in the range of 20 to 250 μm, and further preferably set to a value in the range of 30 to 190 μm.

When the base material 16 is a release film, the type thereof includes at least one of a polyester film (PET film, etc.) having a release surface, an olefin film, an acrylic film, a urethane film, a polycarbonate film, a TAC film, a fluorine film, a polyimide film, and the like. There is one.
The peeling surface in the present specification includes both a surface that has been subjected to the peeling treatment and a surface that exhibits peelability even without the peeling treatment.

The thickness of the release film as the base material 16 is determined in consideration of the application, light transmittance, and the like, but is usually preferably in the range of 10 to 300 μm.
The reason for this is that if the thickness of the release film is 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, it may sweep in a roll shape or become difficult to handle.
Therefore, the thickness of the release film is more preferably set to a value in the range of 20 to 250 μm, and further preferably set to a value in the range of 30 to 200 μm.

As the optical characteristics of the base material (functional film, release film, etc.) 16, it is preferable that the base material (functional film, release film, etc.) 16 has transparency suitable for use in touch panels, liquid crystal display devices, and the like.
That is, the lower limit of the visible light transmittance of the resin plate 12 is preferably 60% or more, more preferably 75% or more, and further preferably 85% or more.
The upper limit of the visible light transmittance of the resin plate 12 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 the value to.

4. Various physical properties of the machinability improving layer (1) Storage elastic modulus before irradiation with active energy rays (M1)
The machinability improving layers 14 and 14'according to the present embodiment preferably have a storage elastic modulus (M1) before irradiation with active energy rays in the range of 0.01 to 1 MPa.
The reason for this is that by controlling the storage elastic modulus (M1) described above within a predetermined range, the flexibility of the machinability improving layer 14 before irradiation with active energy rays becomes appropriate, and the adhesiveness to the resin plate 12 becomes appropriate. This is because the result is good.
Therefore, it is more preferable to set the storage elastic modulus (M1) before irradiation with active energy rays to a value in the range of 0.04 to 0.20 MPa, and further, both durability and machinability after irradiation with active energy rays are compatible. It is more preferable to set the value in the range of 0.07 to 0.08 MPa because it is easy to carry out.
Unless otherwise specified, in the present specification, it means the storage elastic modulus (M1, M2) corresponding to a temperature of 25 ° C. (hereinafter, the same applies).

(2) Storage elastic modulus after irradiation with active energy rays (M2)
In the machinability improving layers 14 and 14'according to the present embodiment, the storage elastic modulus (M2) after irradiation with active energy rays is preferably set to a value of 0.10 MPa or more.
The reason for this is that by controlling the storage elastic modulus (M2) to a value of 0.10 MPa or more, the machinability improving film 18 is attached to the resin plate 12 and cut using a cutting device. This is because chipping due to the improved machinability layer and occurrence of protrusion are suppressed, and good machinability can be obtained.
Therefore, the lower limit of the storage elastic modulus (M2) is preferably 0.20 MPa or more, more preferably 0.25 MPa or more, and further preferably 0.30 MPa or more.
On the other hand, if the above-mentioned storage elastic modulus (M2) value becomes excessively large, the durability may decrease. Therefore, the upper limit of the storage elastic modulus (M2) is preferably a value of 5 MPa or less, more preferably a value of 2 MPa or less, particularly preferably a value of 1 MPa or less, and a value of 0.6 MPa or less. Is more preferable.

(3) Increase rate of storage elastic modulus (M2 / M1 × 100)
The machinability improving layers 14 and 14'according to the present embodiment have an increase rate (= M2 / M1) of the storage elastic modulus (M1) before the active energy ray irradiation with respect to the storage elastic modulus (M2) after the active energy ray irradiation. X100) is usually preferably set to a value in the range of 320 to 30,000%.
The reason for this is that by controlling the increase rate (%) of the storage elastic modulus to a value within a predetermined range, the adhesiveness to the resin plate 12 before irradiation with active energy rays and the durability before and after irradiation with active energy rays This is to make it easy to achieve both property and machinability.
Therefore, the rate of increase (%) of the storage elastic modulus is more preferably set to a value in the range of 350 to 10,000%, and further preferably set to a value in the range of 380 to 1000%.

(4) Gel fraction before irradiation with active energy rays (G1)
For the machinability improving layers 14 and 14'in the present embodiment, the gel fraction (G1) before irradiation with active energy rays is usually preferably set to a value within the range of 40 to 78%.
The reason for this is that by controlling the gel fraction (G1) to a value within a predetermined range, the adhesiveness to the resin plate 12 can be improved.
More specifically, when the gel fraction (G1) is less than 40%, the handleability of the machinability improving film 18 may deteriorate due to insufficient cohesive force of the machinability improving layer 14.
On the other hand, when the gel fraction (G1) described above is a value exceeding 78%, the machinability improving layer 14 may become too hard, and the adhesiveness to the resin plate 12 may deteriorate.
Therefore, the gel fraction is more preferably set to a value in the range of 50 to 76%, and even more preferably set to a value in the range of 60 to 70%.

(5) Gel fraction after irradiation with active energy rays (G2)
The machinability improving layers 14 and 14'according to the present embodiment are characterized in that the gel fraction (G2) after irradiation with active energy rays is set to a value of 75% or more.
The reason for this is that if the gel fraction (G2) is less than 75%, the machinability may be significantly lowered and adhesive residue may be generated.
Therefore, the lower limit of the gel fraction (G2) is more preferably 77% or more, particularly preferably 79% or more, and even more preferably 80% or more.
The upper limit of the gel fraction (G2) is not particularly limited, but may be 100%, but from the viewpoint of achieving both machinability and durability, 95% or less is preferable, and 90% or less is preferable. Especially preferable.
The method for measuring the gel fraction (G2) will be described in detail in Examples described later.

(6) Increase rate of gel fraction (G2 / G1 × 100)
The machinability improving layers 14 and 14'according to the present embodiment have an increase rate (= G2 / G1) of the gel fraction (G1) before the active energy ray irradiation with respect to the gel fraction (G2) after the active energy ray irradiation. X100) is usually preferably set to a 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 adhesiveness to the resin plate 12 before the irradiation with the active energy ray becomes suitable, and after the irradiation with the active energy ray. This is because it is easy to achieve both durability and machinability in the above.
More specifically, when the rate of increase in the gel fraction is less than 110%, the machinability is lowered, the machinability improving layers 14 and 14'are chipped, and the durability is lowered. May be done.
On the other hand, when the rate of increase in the gel fraction exceeds 250%, the machinability improving layers 14 and 14'may become brittle and crack.
Therefore, the rate of increase in the gel fraction is more preferably in the range of 114-200%, more preferably in the range of 120-160%, and in the range of 128-140%. It is particularly preferable to use a value.

(7) Adhesive strength before irradiation with active energy rays (P1)
The machinability-improving film 18 according to the present embodiment is characterized in that the adhesive force (P1) before irradiation with active energy rays is set to a value of 1 N / 25 mm or more.
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 12 is improved.
If the adhesive force (P1) is less than 1N / 25 mm, it becomes difficult to attach the resin plate 12 to the resin plate 12 in the first place, or even if the adhesive force (P1) can be attached, the resin plate 12 can be attached to the machineability improving layer 14 during the process. May be more likely to come off.
On the other hand, the adhesive force (P1) is preferably 60 N / 25 mm or less.
This is because when the adhesive force (P1) exceeds 60 N / 25 mm, the handleability tends to deteriorate.
Therefore, the adhesive strength (P1) is more preferably set to a value within the range of 8 to 40 N / 25 mm, and further preferably set to a value of 15 to 30 N / 25 mm.
The adhesive strength (P1) can be measured by a 180-degree peeling method according to JIS Z0237: 2009 before irradiation with active energy rays. A more specific measurement method is described in Examples described later. As shown.

(8) Adhesive strength after irradiation with active energy rays (P2)
The machinability improving film 18'according to the present embodiment is characterized in that the adhesive force (P2) after irradiation with active energy rays is set to a value of 10 N / 25 mm or more.
The reason for this is that by controlling the adhesive force (P2) to a value of 10 N / 25 mm or more, the adhesiveness becomes good and excellent durability is exhibited.
Therefore, the lower limit of the adhesive force (P2) is preferably 15 N / 25 mm or more, more preferably 20 N / 25 mm or more, and further preferably 24 N / 25 mm or more.
On the other hand, the upper limit of the adhesive force (P2) is preferably 200 N / 25 mm or less, more preferably 120 N / 25 mm or less, and further preferably 60 N / 25 mm or less. It is particularly preferable that the value is 40 N / 25 mm or less.
The adhesive strength (P2) can be measured by a 180-degree peeling method according to JIS Z0237: 2009 after irradiation with active energy rays, but a more specific measurement method will be described in Examples described later. As shown.

(9) Adhesive strength increase rate (= P2 / P1 × 100)
The machinability improving films 18 and 18 ′ according to the present embodiment have an increase rate (= P2 / P1 × 100) of the adhesive force (P1) before the active energy ray irradiation with respect to the adhesive force (P2) after the active energy ray irradiation. ) Is preferably a value of 80 to 300%.
The reason for this is that by controlling the increase rate of the adhesive force to a value within a predetermined range, both the adhesiveness to the resin plate 12 before the irradiation with the active energy ray and the durability after the irradiation with the active energy ray can be achieved. This is because it becomes easy.
Therefore, the rate of increase in adhesive strength is more preferably set to a value in the range of 100 to 200%, and further preferably set to a value in the range of 120 to 140%.

(10) Maximum stress (S2)
In the machinability improving film 18'according to the present embodiment, the maximum stress (S2) when the tensile stress after irradiation with active energy rays is measured is usually preferably set to a value of 1.5 N / mm ² or more. ..
The reason for this is that by setting the maximum stress (S2) to a value of 1.5 N / mm ² or more, the chipping of the machinability improving layer 14'tends to be suppressed during machining, and the machinability is good. This is because.
Therefore, it is more preferable to take up stress (S2) and 2.0 N / mm ² or more values and more preferably be 2.5 N / mm ² or more values in terms of compatibility between durability.
On the other hand, the upper limit of the maximum stress (S2) is not particularly limited, but is preferably 20 N / mm ² or less, preferably 10 N / mm ² or less, from the viewpoint of achieving both durability and machinability. It is more preferable to set the value to 4 N / mm ² or less.

(11) 100% elongation stress (E2)
The machinability improving film 18'according to the present embodiment preferably has a stress (E2) at 100% elongation after irradiation with active energy rays, usually set to a value of 10 N / mm ² or less.
The reason for this is that by setting the 100% elongation stress (E2) to a value of 10 N / mm ² or less, the machinability improving layer 14'tends to be difficult to stretch during machining, and the machinability after cutting tends to be difficult. This is because it is possible to obtain a cut surface in which the improving layer 14'does not protrude, and thus the machinability is improved.
Therefore, it is more preferable to set the upper limit value of the 100% elongation stress (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 100% elongation stress (E2) is not particularly limited, but is preferably 0.1 N / mm ² or more, preferably 0.4 N, from the viewpoint of achieving both durability and machinability. A value of / mm ² or more is more preferable, and a value of 0.7 N / mm ² or more is particularly preferable.

5. Laminated body The laminated body 10, 10'using the machinability improving films 18 and 18'according to the present embodiment is formed by laminating the machinability improving films 18 and 18'shown in FIG. 1A and the like. The laminate is not particularly limited as long as it is a laminated body composed of the resin plate 12.
Therefore, various functional films used in various devices are machined (cut) with high accuracy together with the resin plate 12 via the machineability improving layer 14', and the functional film with the resin plate is laminated. It can be easily manufactured as a body 10, 10'.
Hereinafter, aspects of the laminated bodies 10, 10'will be specifically described.

(1) Laminated body before active energy ray curing The laminated body 10 before active energy ray curing is as shown in FIGS. 1 (a), 2 (c), 3 (d), 4 (d) and the like. , A laminated body 10 in which a functional film as a base material 16, a machinability improving film 18, and a resin plate 12 are sequentially laminated.
In addition, FIGS.

(2) Laminated body after active energy ray curing The laminated body 10'after active energy ray curing receives active energy rays from the base material 16 of the laminated body 10 before active energy ray curing or the resin plate 12 side. By irradiating, the machinability improving layer 14 can be made into the cured machinability improving layer 14'.
That is, as shown in FIGS. 2 (d) and 2 (e), 3 (e) and 3 (f), 4 (e) and 4 (f), the functional film as the base material 16. This is a laminated body 10'in which the hardened machinability improving layer 14'and the resin plate 12 are sequentially laminated.

The cured machinability improving layer 14'is a product obtained by curing the machinability improving layer 14 of the above-mentioned machinability improving film 18 by irradiation with active energy rays.
In the present embodiment, the cured mechanicability improving layer 14'is based on a crosslinked structure in which a (meth) acrylic acid ester copolymer as a main agent (A) and a crosslinkable component (B) are formed by heat. It is composed of a pressure-sensitive adhesive having a structure (polymerized structure) in which the active energy ray-curable component (C) is polymerized and cured.
It is presumed that the polymerized structure is entwined with a crosslinked structure composed of a (meth) acrylic acid ester copolymer as a main agent (A) and a crosslinkable component (B).
By having a structure in which a plurality of three-dimensional structures are entangled, the machinability improving layer 14'after curing has a high cohesive force, and easily satisfies the desired adhesive force and gel fraction values. Become.
Therefore, the improved machinability layer 14'after curing exhibits excellent machinability and also has excellent durability.

As long as the effects of the present invention can be obtained, the above-mentioned cured machinability improving layer 14'contains a photopolymerization initiator (D) that has not been cleaved by irradiation with active energy rays. May be good.
In the present embodiment, the remaining amount of the photopolymerization initiator in the hardened machinability improving layer 14'is preferably 0.1% by mass or less, and more preferably 0.01% by mass or less. ..

6. Usage method As a method of using the machinability improving film 18, as illustrated in FIGS. 2A to 2E, after obtaining the desired machinability improving film 18 in the preparatory step, the following step (1) ) To (3) are preferably included.
(1) Step of attaching the obtained machinability improving film 18 to the resin plate 12 (2) Activity in the machinability improving layer 14 by irradiating active energy rays from the resin plate 12 or the base material 16 side Step of curing the energy ray-curable component to form a machinability improving layer 14'after curing (3) Predetermined with respect to the laminate 10'including the machinability improving layer 14'after curing and the resin plate 12 The process of performing the machining process of No. 1 Hereinafter, a method of using the machinability improving film 18 will be specifically described with reference to the drawings as appropriate.

6-1: Preparation process (1)
The preparatory step (1) is a preparatory step for the composition for forming the machinability improving layer 14.
Therefore, the resin layer 13 derived from the composition for forming the machinability improving layer 14 shown in FIG. 2A and the like is combined with the (meth) acrylic acid ester copolymer as the main agent (A). , A composition containing a crosslinkable component (B) and an active energy ray-curable component (C) as main components.
The composition may contain a photopolymerization initiator (D), a silane coupling agent (E), an organic solvent, etc., if necessary, and by uniformly mixing these, the resin layer 13 is formed. A coating solution can be obtained.

6-2: Preparation process (2)
The preparation step (2) is a step of applying a coating liquid containing the above-mentioned predetermined composition.
Therefore, as shown in FIG. 2A, the coating liquid of the above-mentioned composition is applied to the surface of the base material (functional film or the like) 16 to form the base material 16 and the machinability improving layer 14. A laminate is obtained in which the resin layer 13 derived from the composition for this purpose is laminated.
The method of applying the coating liquid is not particularly limited and can be carried out by a known method. Examples thereof include a bar coating method, a knife coating method, a roll coating method, a blade coating method, a die coating method and a gravure coating method. Will be done.
Then, as shown in FIG. 2 (b), a predetermined heat treatment (H) is performed to cause a thermal cross-linking reaction between the functional group contained in the main agent (A) and the cross-linking component (B) to generate active energy. By forming the linearly curable machinability improving layer 14, the machinability improving film 18 is obtained.
The heat treatment (H) can also serve as scattering removal of a 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 160 ° C, more preferably 70 to 140 ° C.
The heating time is preferably 10 seconds to 10 minutes, more preferably 50 seconds to 2 minutes.
Further, after the heat treatment, it is preferable to provide a curing period of about 1 to 2 weeks at room temperature (for example, 23 ° C., 50% RH).
By such heat treatment (and curing), the (meth) acrylic acid ester copolymer is satisfactorily crosslinked via the crosslinkable component (B), and a crosslinked structure is formed.
That is, through such a step, a machinability improving layer 14 formed by heat-crosslinking a resin layer 13 derived from a composition for forming the machinability improving layer 14 is obtained, and predetermined machining is performed. It becomes the property improving film 18.
The other components (active energy ray-curable component (C), photopolymerization initiator (D), coupling agent (E), etc.) contained in the composition for forming the machinability improving layer 14 are The content and properties do not change before and after thermal crosslinking.

6-3: Step (1)
Next, the step (1) is a step of laminating the machinability improving film 18 on the resin plate 12.
Therefore, as shown in FIG. 2C, the resin plate 12 and the machinability improving layer 14 of the machinability improving film 18 are bonded and laminated.
A known bonding method such as a ramimeter can be used for bonding the resin plate 12 and the machinability improving film 18.
As a result, the laminated body 10 in which the active energy ray-curable machinability improving layer 14 is sandwiched between the base material (functional film or the like) 16 and the resin plate 12 can be obtained.

6-4: Step (2)
Next, the step (2) is an irradiation step of irradiation of active energy rays.
Therefore, as shown in FIG. 2D, active energy rays (L) such as ultraviolet rays are irradiated from the surface of the base material 16 opposite to the side in contact with the machinability improving layer.
As a result, the active energy ray-curable component (C) in the machinability improving layer 14 is cured, and the cured machinability improving layer 14'is formed.
That is, the hardened machinability improving layer 14'can obtain a laminated body 10' sandwiched between the base material (functional film or the like) 16 and the resin plate 12.
In FIG. 2D, the active energy rays (L) are irradiated from the back side of the resin plate 12, but the side on which the base material (functional film or the like) 16 is provided, that is, the resin side. The active energy ray (L) may be irradiated from the opposite side to the active energy ray (L), and further, the active energy ray (L) may be irradiated from both the back surface side of the resin plate 12 and the base material (functional film or the like) 16 side. May be irradiated.

Here, the active energy ray refers to an electromagnetic wave or a charged particle beam having an energy quantum, and specific examples thereof include an ultraviolet ray and an electron beam.
The active energy ray in the present 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 dose of the active energy ray is preferably illuminance is 50 mW / cm ² or more 1000 mW / cm ² or less.
Amount is preferably at 50 mJ / cm ² or more, more preferably 80 mJ / cm ² or more, more preferably 200 mJ / cm ² or more.
Further, the light amount is preferably at 10000 mJ / cm ² or less, more preferably 5000 mJ / cm ² or less, still more preferably 2000 mJ / cm ² or less.

6-5: Step (3)
Finally, step (3) is a machining process.
Therefore, as shown in FIG. 2E, a predetermined machining process (for example, for example) is performed on the resin plate 12 on which the machinability improving layer 14'is laminated together with the base material (functional film or the like) 16. The cutting process in the direction indicated by the arrow A) will be performed.
Since the machinability-improving film 18 of the present embodiment has excellent machinability, a laminated body 10'having a desired shape can be easily obtained by a single cutting process.
Further, since the machinability improving layer 14'is not chipped or stretched in the cutting process, the cut surface after processing is good, and the obtained laminated body 10'has excellent appearance quality.
Further, since the obtained laminate 10'is excellent in durability, it can be applied to optical components (for example, an in-vehicle touch panel, a liquid crystal display device, etc.) used in a harsh environment.
Therefore, by using the machinability improving film 18 of the present embodiment as described above, a functional film via the machinability improving layer 14'applicable to optical parts such as touch panels and liquid crystal display devices. A resin plate with a plate can be easily manufactured.

7. Other usage 7-1 Modification 1
The steps exemplified in FIGS. 3A to 3F are examples of steps when the base material (release film or the like) 16 is used in the preparation step (1) described above.
Therefore, for example, when a base material (release film or the like) 16 is used, by including the following steps (1') to (3') as illustrated in FIGS. 4 (a) to 4 (f), the machine The workability-improving film 18 can be suitably used for machining processing (cutting processing).

(1) Preparation process (1')
The preparation step (1') is a step of applying the resin layer 13 to the base material and a heat treatment step.
That is, as shown in FIGS. 3A and 3B, a resin layer 13 derived from a composition for forming a machinability improving layer 14 is formed on the surface of a base material (release film or the like) 16. This is a step of forming a machinability-improving film 18'including a machinability-improving layer 14 by coating and heat-treating (H).
Here, the preparation step and the coating step of the composition for forming the machinability improving layer 14 are based on the preparation steps (1) and the preparation steps (2) described above.
Although not shown, in FIG. 3B, a base material (release film or the like) 16 may be provided on the exposed surface of the machinability improving layer 14.
With such a configuration, the risk of contamination of the machinability improving layer 14 until use is reduced.

(2) Step (1')
Next, the step (1') is a step of laminating the machinability improving film 18'on the resin plate 12.
That is, as shown in FIGS. 3C and 3D, the exposed surface of the machinability improving layer 14 of the machinability improving film 18'and the base material (functional film) 16 are bonded together. And stack.
Then, the base material (release film or the like) 16 is peeled off, and the resin plate 12 is laminated.
As a result, the laminated body 10 in which the active energy ray-curable machinability improving layer 14 is sandwiched between the base material (functional film or the like) 16 and the resin plate 12 can be obtained.

(3) Step (2')
Next, the step (2') is a step of irradiating the active energy rays.
Therefore, as shown in FIG. 3E, 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. Let it be layer 14'. That is, the hardened machinability improving layer 14'can obtain a laminated body 10' sandwiched between the base material (functional film or the like) 16 and the resin plate 12.
The irradiation conditions of the active energy rays and the like are the same as in the above-mentioned step (2).

(4) Step (3')
Finally, the step (3') is a machining process.
Therefore, as shown in FIG. 3 (f), a predetermined machining process (for example, an arrow) is performed on the resin plate 12 on which the machinability improving layer 14'is laminated together with the base material (functional film or the like) 16. Cutting process in the direction indicated by A) is performed.
Then, also in the above-mentioned steps (1') to (3'), similarly to the above-mentioned steps (1) to (3), the machinability improving films 18 and 18'of the present embodiment are preferably used. Can be done.
Therefore, also in the first modification, it is possible to easily manufacture a resin plate with a functional film via the machinability improving layer 14', which can be applied to optical parts such as touch panels and liquid crystal display devices.

7-2 Modification 2
The steps illustrated in FIGS. 4A to 4F are examples of steps in the above-mentioned step (1') of the modified example 1 in which the order of bonding the machinability improving film 18'is different.
That is, as shown in FIG. 4 (c), the exposed surface of the machinability improving layer 14 of the machinability improving film 18'shown in FIG. 4 (b) and the resin plate 12 are laminated and laminated. ..
Then, as shown in FIG. 4D, it is a step of peeling off the base material (release film or the like) 16 and laminating the base material (functional film) 16. The steps other than the above-mentioned step (1') are the same as those of the above-mentioned modification 1.
Therefore, also in the modified example 2, the machinability improving films 18 and 18'of the present embodiment are used in the same manner as in the above-mentioned steps (1) to (3) and the above-mentioned steps (1') to (3'). It can be preferably used.
Therefore, also in the steps (1') to (3'), a resin plate with a functional film via a machinability improving layer 14', which can be applied to optical parts such as a touch panel and a liquid crystal display device, can be easily used. Can be manufactured in.

Hereinafter, the method of using the machinability-improving film and the machinability-improving film of the present embodiment will be described in more detail with reference to Examples.
However, the present embodiment is not limited to the description of these examples without particular reason.

[Example 1]
1. 1. Preparation and use of workability-improving film 1- (1) Adjustment of main agent (A) 30 parts by weight of n-butyl acrylate, 25 parts by weight of 2-ethylhexyl acrylate, and 10 parts by weight of isobornyl acrylate as monomer components , 5 parts by weight of methyl methacrylate, 5 parts by weight of N-acryloylmorpholine, and 25 parts by weight of 2-hydroxyethyl acrylate are solution-polymerized to carry the (meth) acrylic acid ester copolymer as the main agent (A). Adjusted the coalescence.
The weight average molecular weight (Mw) of the obtained (meth) acrylic acid ester copolymer was measured by the method shown below and found to be 500,000.

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

The details of the abbreviations and the like shown in Table 1 are as follows.
(Main agent (A): ((meth) acrylic acid ester copolymer))
BA: n-butyl acrylate 2EHA: 2-ethylhexyl acrylate IBXA: isobornyl acrylate MMA: methyl methacrylate ACMO: N-acryloylmorpholine HEA: 2-hydroxyethyl acrylate AA: 4HBA acrylate: 4-hydroxy acrylate Butyl HEMA: 2-hydroxyethyl methacrylate

1- (2) Preparation of composition for forming a mechanization-improving layer Next, a crosslinkable component with respect to 100 parts by weight of the (meth) acrylic acid ester copolymer (solid content) as the main agent (A). 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 the active energy ray-curable component (C). And 0.8 parts by weight of 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide as the photopolymerization initiator (D), and 3-glycidoxypropyltrimethoxy as the silane coupling agent (E). Silane was blended in a proportion 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.

The details of the abbreviations and the like described in Table 1 are as follows.
(Crosslinkable 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) Process for forming a layer for improving machinability A heavy release type release film (manufactured by Lintec Corporation, product name "SP-PET752150") in which one side of a polyethylene terephthalate film is peeled off with a silicone-based release agent from the obtained coating solution. ”) Was applied to the peeled surface using a bar coater so that the thickness after drying was 15 μm.
Then, the coated layer is heat-treated at 90 ° C. for 1 minute to allow the thermal cross-linking reaction to proceed, and is composed of the (meth) acrylic acid ester copolymer as the main agent (A) and the cross-linking component (B). A machinability improving layer having a crosslinked structure was formed.

Next, a light release type release film (manufactured by Lintec Corporation, product name "SP-PET382120") obtained by peeling the coating layer on the heavy release type release film obtained above and one side of the polyethylene terephthalate film with a silicone-based release agent. The light peeling type peeling film was bonded so that the peeling surface of the light peeling type peeling film was in contact with the machinenability improving layer, and cured under the conditions of 23 ° C. and 50% RH for 7 days to perform heavy peeling type peeling. A workability-improving film for evaluation was prepared, which consisted of a film / a workability-improving layer (thickness: 15 μm) / a light-release release film.
The thickness of the machinability improving layer is a value measured using a constant pressure thickness measuring instrument (manufactured by Teclock Co., Ltd., product name "PG-02") in accordance with JIS K7130.

2. 2. Evaluation of machinability-improving film 2- (1) Measurement of adhesive strength (P1) before irradiation with active energy rays Among the evaluation machinability-improving films, the light-release type release film is peeled off from the machinability-improving layer. , Polyethylene terephthalate (PET) film with an easy-adhesion layer (manufactured by Toyo Boseki Co., Ltd., product name "PET A4300", thickness: 100 μm), which is affixed to the easy-adhesion layer, and is a heavy-release type release film / machine-processability improving layer ( A laminate of 15 μm) / PET film was obtained.
The obtained laminate was cut into a width of 25 mm and a length of 150 mm, and this was used as a sample.
In an environment of 23 ° C. and 50% RH, the heavy-release type release sheet is peeled off from the sample obtained above, the exposed machinability improving layer is attached to a glass plate, and then a 2 kg roller is reciprocated once. It was crimped with.
Then, after leaving it for 24 hours under the conditions of 23 ° C. and 50% RH, the adhesive strength (P1) was set to a peeling speed of 300 mm / min and a peeling angle of 180 degrees using a tensile tester (Tensilon manufactured by Orientec). , N / 25 mm) was measured.
The conditions other than those described here were measured in accordance with JIS Z 0237: 2000. The results are shown in Table 2.

2- (2) Measurement of adhesive strength (P2) after irradiation with active energy rays In an environment of 23 ° C. and 50% RH, the heavy-release type release sheet was peeled off from the sample obtained above to expose the machinability. After the improving layer was attached to a glass plate, it was crimped by reciprocating a 2 kg roller once, and ultraviolet rays were irradiated from the PET film side as active energy rays under the following conditions.
Then, after leaving it to stand for 24 hours under the conditions of 23 ° C. and 50% RH, it is irradiated with active energy rays under the conditions of a peeling speed of 300 mm / min and a peeling angle of 180 degrees using a tensile tester (Tensilon manufactured by Orientec). The subsequent adhesive strength (P2, N / 25 mm) was measured.
The conditions other than those described here were measured in accordance with JIS Z 0237: 2000. The results are shown in Table 2.
<Ultraviolet irradiation conditions>
・ Uses high-pressure mercury lamp ・ Illuminance 200mW / cm ² , light intensity 2000mJ / cm ²
・ UV illuminance / photometer uses "UVPF-A1" manufactured by iGraphics.

2- (3) Calculation of increase rate of adhesive force The rate of increase of adhesive force (P2) after irradiation with active energy rays (= P2 / P1 × 100) with respect to the adhesive force (P1) before irradiation with active energy rays measured above. ,%) Was calculated. The results are shown in Table 2.

2- (4) Measurement of gel fraction (G1) before irradiation with active energy rays Of the obtained evaluation machinability improving films, 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 machinability improving layer alone was calculated by subtracting the mass of the mesh alone. The mass at this time is m1.
Next, the machinability improving layer wrapped in the polyester mesh prepared by the above method was immersed in ethyl acetate at room temperature (23 ° C.) for 72 hours.
Then, the machinability improving layer wrapped in the polyester mesh was taken out, air-dried for 24 hours in an environment of 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 (m2) of the machinability improving layer before irradiation with active energy rays was calculated.
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. The results are shown in Table 2.

2- (5) Measurement of gel fraction (G2) after irradiation with active energy rays The light release type release film was peeled off from the obtained evaluation machinability improvement film, and the exposed machinability improvement layer was removed. The layer for improving machinability was cured by directly irradiating the active energy ray under the above-mentioned conditions.
The mass of the hardened machinability improving layer was weighed with a precision balance, and the mass (m3) of the machinability improving layer after irradiation with active energy rays was calculated.
Based on the mass calculated above, the gel fraction (G2) (= (m3 / m1) × 100,%) of the machinability improving layer after irradiation with active energy rays was derived. The results are shown in Table 2.

2- (6) Calculation of the increase rate of the gel fraction (G2) The increase rate of the gel fraction (G2) after the activation energy ray irradiation (= G2 /) with respect to the gel fraction (G1) before the activation energy ray irradiation derived above. G1 × 100,%) was calculated. The results are shown in Table 2.

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

2- (8) Measurement of storage elastic modulus (M1) before irradiation with active energy rays Of the obtained evaluation machinability improving films, only the machinability improving layer is based on JIS K7244-4: 1999. Using a viscoelasticity measuring device (manufactured by TA Instruments, ARES, frequency 1 Hz), the storage elastic modulus (M1, MPa (25 ° C.)) of the machinability improving layer before irradiation with active energy rays is measured. did. The results are shown in Table 2.

2- (9) Measurement of storage elastic modulus (M2) after irradiation with active energy rays The light release type release film was peeled off from the obtained evaluation machinability improvement film, and the exposed machinability improvement layer was removed. The layer for improving machinability was cured by directly irradiating the active energy ray under the above-mentioned conditions.
For only the hardened 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 described above. The results are shown in Table 2.

2- (10) Calculation of increase rate of storage elastic modulus The rate of increase of storage elastic modulus (M1) before activation energy ray irradiation (= M2 /) with respect to the storage elastic modulus (M2) after activation energy ray irradiation measured above. M1 × 100,%) was calculated. The results are shown in Table 2.

2- (11) Evaluation of machinability The lightly peelable release sheet of the obtained evaluation machinability improving film 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 irradiating the active energy ray under the above-mentioned conditions to cure the machinability improving layer, the test piece was cut in the vertical direction with respect to one PET film surface of the test piece using a cutter.
Then, the cut surface was observed under a microscope, and the machinability was evaluated according to the following criteria.
⊚: No chipping or elongation of the machinability improving layer was observed, and the cutting surface was good.
◯: Slight chipping and elongation of the machinability improvement layer were observed, but the cutting surface had no problem in practical use.
Δ: The machinability improving layer was chipped or stretched, which was not preferable for practical use.
X: The cutting surface was unusable due to the observation of chipping and elongation of the machinability improving layer.

2- (12) Evaluation of Durability The lightly peelable release sheet of the obtained evaluation machinability improving film was peeled off, and the exposed machinability improving layer was made of polymethylmethacrylate (PMMA) and polycarbonate (PC). Was affixed to the polycarbonate side surface of the laminated resin plate (thickness: 1 mm, containing an ultraviolet absorber).
Further, a test piece is obtained by peeling the heavy release type release sheet from the evaluation machinability improving film and attaching the exposed machinability improving layer to a TAC film (thickness 100 μm) as a functional film. It was. The obtained test piece was autoclaved under the conditions of 50 ° C. and 0.5 MPa for 30 minutes, and then left at normal pressure at 23 ° C. and 50% RH for 24 hours.
Then, the active energy ray was irradiated from the resin plate side under the above-mentioned conditions to cure the machinability improving layer, and then the layer was stored at 85 ° C. and 85% RH under high temperature and high humidity conditions for 500 hours.
After that, the floating and peeling at the interface between the machinability improving layer and the adherend was visually confirmed, and the durability was evaluated according to the following criteria. The results are shown in Table 2.
⊚: Neither air bubbles nor floating can be confirmed.
◯: A small amount of minute bubbles are generated, but large bubbles and peeling cannot be confirmed.
X: Large bubbles or floating can be confirmed.

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

As described in detail above, according to the machinability improving film of the present invention, the adhesive strength (P1) of the machinability improving layer before irradiation with active energy rays and the machinability after irradiation with active energy rays. By setting the gel fraction (G2) of the improving layer to a predetermined value or more, even when the machinability improving layer is cut at the same time with the resin plate included by using a machining apparatus. , Good machinability can be obtained.
Further, in the predetermined machinability improving film, by setting the adhesive force (P2) of the machinability improving layer after irradiation with the active energy ray to a predetermined value, good durability against the resin plate can be obtained. Became.

Then, a machinability improving film provided with such a machinability improving layer, a laminate containing 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 for using a film with improved workability.
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': Laminated body 12: Resin plate 13: Resin layer 14: Machinability improving layer 14': Machinability improving layer after curing 16: Base materials 18, 18': Machinability improving film

Claims (6)

A machinability-enhancing film having a base material and a machinability-improving layer.
It contains an active energy ray-curable component and a reaction product of a crosslinkable component.
The adhesive strength before irradiation with the active energy ray is set to a value of 1N / 25 mm or more, and the adhesive strength after irradiation with the active energy ray is set to a value of 10 N / 25 mm or more.
Further, a machinability improving film having an active energy ray-curable machinability improving layer in which the gel fraction becomes a value of 75% or more by irradiation with the active energy rays. The reaction product of the cross-linking component is a reaction product of a (meth) acrylic acid ester copolymer derived from a reactive functional group-containing monomer and a (meth) acrylic acid alkyl ester monomer, and a thermal cross-linking agent. The mechanicability-improving film according to claim 1, which is characterized. The machinability-improving film according to claim 2, wherein the reactive functional group-containing monomer is a hydroxyl group-containing monomer or a carboxy group-containing monomer. A laminate characterized in that the machinability-improving film according to any one of claims 1 to 3 is attached to a resin plate. The laminate according to claim 4, wherein the resin plate is an optical resin plate. The method for using the machinability-improving film according to any one of claims 1 to 3, wherein the method for using the machinability-improving film includes the following steps (1) to (3).
(1) A step of attaching the machinability improving film to a resin plate (2) A step of irradiating an active energy ray to cure an active energy ray curable component (3) A process of improving machinability and a resin plate A process of applying a predetermined machining process to a laminate

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