JP7850705B2 - Hard coat film laminates, hard coat film laminates with adhesive layers, and methods for manufacturing the same. - Google Patents

Description

This invention relates to hard coat film laminates, hard coat film laminates with an adhesive layer, and methods for manufacturing the same.

In recent years, various types of displays, such as liquid crystal displays (LCDs) and organic light-emitting diode (OLEDs), have been widely used in various electronic devices, and are sometimes used as touch panels. These displays often have a hard coat film applied to their surface to prevent scratches.

A hard coat film typically comprises a substrate and a hard coat layer laminated on one side of the substrate. A common method for manufacturing such a hard coat film involves applying the hard coat layer material to one side of a pre-manufactured substrate to form the hard coat layer on the substrate (see, for example, Patent Document 1).

Furthermore, Patent Document 2 discloses a technique for transferring only the hard coat layer onto an object using a transfer-type hard coat film having a hard coat layer on a transfer substrate. However, this technique lacks versatility because, since there is no substrate on which the hard coat layer is formed, it is not possible to form other functional layers on certain objects.

Japanese Patent Publication No. 2016-112834 Japanese Patent Publication No. 2020-157684

Incidentally, in recent years, devices equipped with the above-mentioned displays have become thinner, and consequently, there is a demand for thinner hard coat films, especially hard coat film substrates. However, as hard coat films become thinner, handling at each stage of the process becomes more difficult.

This invention has been made in view of the above circumstances, and aims to provide a hard coat film laminate with excellent handling properties, a hard coat film laminate with an adhesive layer, and a method for manufacturing the hard coat film laminate and the hard coat film laminate with an adhesive layer.

To achieve the above objective, firstly, the present invention provides a hard coat film laminate comprising a base film and a hard coat film having a hard coat layer formed on one side of the base film, a process film laminated on the side of the hard coat film facing the base film, and a protective film laminated on the side of the hard coat film facing the hard coat layer, wherein the peel strength A of the process film with respect to the hard coat film is 500 mN/50 mm or less, the peel strength B of the protective film with respect to the hard coat film is 500 mN/50 mm or less, and the peel strength B of the protective film with respect to the hard coat film is 50 mN/50 mm or greater than the peel strength A of the process film with respect to the hard coat film (Invention 1).

In the above invention (Invention 1), by providing a process film on one side of the hard coat film and a protective film on the other side of the hard coat film, the process film and protective film act as supports, resulting in excellent handling even if the hard coat film is a thin film. Furthermore, because the peel strengths A and B have the above numerical range and relationship, the process film and protective film can be easily peeled off, and the process film can be stably peeled off before the protective film.

In the above invention (Invention 1), the peel strength A of the process film relative to the hard coat film is preferably 50 mN/50 mm or more (Invention 2).

In the above inventions (Inventions 1 and 2), it is preferable that the peel strength B of the protective film relative to the hard coat film is 200 mN/50 mm or more (Invention 3).

In the above inventions (Inventions 1 to 3), the thickness of the base film in the hard coat film is preferably 0.5 μm or more and 15 μm or less (Invention 4).

In the above inventions (Inventions 1 to 4), it is preferable that the base film in the hard coat film has optical isotropy (Invention 5).

Secondly, the present invention provides a hard coat film laminate with an adhesive layer, comprising: a base film and a hard coat film having a hard coat layer formed on one side of the base film; an adhesive layer laminated on the side of the hard coat film facing the base film; a release sheet laminated on the side of the adhesive layer opposite to the side facing the hard coat film; and a protective film laminated on the side of the hard coat film facing the hard coat layer, wherein the peel strength B of the protective film relative to the hard coat film is 500 mN/50 mm or less, the peel strength C of the release sheet relative to the adhesive layer is 500 mN/50 mm or less, and the peel strength B of the protective film relative to the hard coat film is 50 mN/50 mm or greater than the peel strength C of the release sheet relative to the adhesive layer (Invention 6).

In the above invention (Invention 6), the peel strength C of the release sheet against the adhesive layer is preferably 50 mN/50 mm or more (Invention 7).

Thirdly, the present invention provides a method for manufacturing a hard coat film laminate, comprising the steps of: forming a base film on a process film; forming a hard coat layer on the side of the base film opposite to the side facing the process film; and laminating a protective film on the side of the hard coat layer opposite to the side facing the base film, wherein the laminate including the base film and the hard coat layer constitutes a hard coat film, characterized in that the peel strength A of the process film relative to the hard coat film is 500 mN/50 mm or less, the peel strength B of the protective film relative to the hard coat film is 500 mN/50 mm or less, and the peel strength B of the protective film relative to the hard coat film is 50 mN/50 mm or greater than the peel strength A of the process film relative to the hard coat film (Invention 8).

Fourthly, the present invention provides a method for manufacturing a hard coat film laminate with an adhesive layer, comprising the steps of: forming a base film on a process film; forming a hard coat layer on the side of the base film opposite to the side facing the process film; laminating a protective film on the side of the hard coat layer opposite to the side facing the base film; peeling the process film from the base film to expose the base film; and attaching the adhesive layer side of an adhesive sheet having an adhesive layer and a release sheet to the exposed base film, wherein the laminate including the base film and the hard coat layer constitutes a hard coat film, wherein the hard coat layer of the process film The invention provides a method for manufacturing a hard-coat film laminate with an adhesive layer, characterized in that the peel strength A to the film is 500 mN/50 mm or less, the peel strength B of the protective film to the hard-coat film is 500 mN/50 mm or less, the peel strength C of the release sheet to the adhesive layer is 500 mN/50 mm or less, the peel strength B of the protective film to the hard-coat film is 50 mN/50 mm or more greater than the peel strength A of the process film to the hard-coat film, and the peel strength B of the protective film to the hard-coat film is 50 mN/50 mm or more greater than the peel strength C of the release sheet to the adhesive layer.

The hard-coat film laminate and the hard-coat film laminate with an adhesive layer according to the present invention have excellent handling properties. Furthermore, according to the method of the present invention, the hard-coat film laminate and the hard-coat film laminate with an adhesive layer can be manufactured without defects under excellent handling conditions.

This is a cross-sectional view showing a hard coat film laminate according to one embodiment of the present invention. This is a cross-sectional view showing a hard-coat film laminate with an adhesive layer according to one embodiment of the present invention. This is a cross-sectional view showing a method for manufacturing a hard coat film laminate according to one embodiment of the present invention. This is a cross-sectional view showing a method for manufacturing a hard-coat film laminate with an adhesive layer according to one embodiment of the present invention.

Embodiments of the present invention will be described below.
[Hard coat film laminate]
Figure 1 is a cross-sectional view showing a hard coat film laminate according to one embodiment of the present invention. As shown in Figure 1, the hard coat film laminate 1 according to this embodiment comprises a base film 12, a hard coat film 14 having a hard coat layer 13 formed on one side of the base film 12, a process film 11 laminated on the base film 12 side of the hard coat film 14, and a protective film 15 laminated on the hard coat layer 13 side of the hard coat film 14.

In the hard coat film laminate 1 according to this embodiment, since the process film 11 and protective film 15 are present, even if the hard coat film 14 is a thin film, the process film 11 and protective film 15 act as supports, giving it a certain degree of rigidity (stiffness), and as a result, it has excellent handling properties.

Furthermore, in the hard coat film laminate 1 according to this embodiment, the peel strength A of the process film 11 to the hard coat film 14 is 500 mN/50 mm or less, and the peel strength B of the protective film 15 to the hard coat film 14 is 500 mN/50 mm or less, and the peel strength B of the protective film 15 to the hard coat film 14 is 50 mN/50 mm or greater than the peel strength A of the process film 11 to the hard coat film 14. Note that the peel strength in this specification basically refers to the peel strength measured by the 180-degree peel method in accordance with JIS Z0237:2009, and the specific test method is as shown in the test examples described later.

Because the peel strength A of the process film 11 against the hard coat film 14 is within the above range, the process film 11 can be easily peeled off the hard coat film 14, preventing damage to the hard coat film 14 during peeling, and allowing subsequent processes to be carried out without problems. Furthermore, because the peel strength B of the protective film 15 against the hard coat film 14 is within the above range, the protective film 15 can be easily peeled off the hard coat film 14, preventing damage to the hard coat film 14 during peeling, and allowing a good target product to be obtained.

Furthermore, because the relationship between the peel strength B of the protective film 15 against the hard coat film 14 and the peel strength A of the process film 11 against the hard coat film 14 is as described above, the process film 11 can be stably peeled off before the protective film 15. As a result, subsequent processes, such as the application of an adhesive sheet to the hard coat film 14 exposed after peeling off the process film 11, can be performed with the protective film 15 laminated, preventing damage to the hard coat film 14.

The peel strength A of the process film 11 against the hard coat film 14 is preferably 500 mN/50 mm or less, more preferably 300 mN/50 mm or less, more preferably 200 mN/50 mm or less, and even more preferably 150 mN/50 mm or less, from the viewpoint of ease of peeling. On the other hand, the peel strength A of the process film 11 against the hard coat film 14 is preferably 50 mN/50 mm or more, more preferably 60 mN/50 mm or more, and even more preferably 70 mN/50 mm or more. This prevents unintended peeling of the process film 11 during each process.

The peel strength B of the protective film 15 against the hard coat film 14 is preferably 500 mN/50 mm or less, more preferably 450 mN/50 mm or less, more preferably 400 mN/50 mm or less, and even more preferably 350 mN/50 mm or less, from the viewpoint of ease of peeling. On the other hand, the peel strength B of the protective film 15 against the hard coat film 14 is preferably 200 mN/50 mm or more, more preferably 230 mN/50 mm or more, and even more preferably 250 mN/50 mm or more. This prevents unintended peeling of the protective film 15 during each process.

The value obtained by subtracting the peel strength A (mN/50mm) of the process film 11 from the peel strength B (mN/50mm) of the protective film 15 from the hard coat film 14 (peel strength difference (B-A)) is preferably 50 mN/50mm or more, preferably 80 mN/50mm or more, particularly preferably 100 mN/50mm or more, and even more preferably 150 mN/50mm or more, from the viewpoint of the peeling order described above. On the other hand, a larger peel strength difference (B-A) is better, but it is usually 400 mN/50mm or less. This makes it easier to peel off only the process film 11.

1. Each Element 1.1. Process Film The process film 11 according to this embodiment is coated with the material that constitutes the base film 12 of the hard coat film 14. The process film 11 is not particularly limited as long as it can impart rigidity to the hard coat film laminate 1 and form the base film 12 well, but it is preferable that it has solvent resistance to the solvent contained in the coating liquid of the material that constitutes the base film 12.

The process film 11 may be a resin film or a hard material such as a glass plate. However, from the viewpoint of enabling each step for manufacturing the hard coat film 14 according to this embodiment to be carried out roll-to-roll and achieving excellent productivity, the process film 11 is preferably a resin film.

Examples of the above-mentioned resin films include polyester films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin films such as polyethylene films and polypropylene films; cellophane; diacetylcellulose films; triacetylcellulose films; acetylcellulose butyrate films; polyvinyl chloride films; polyvinylidene chloride films; polyvinyl alcohol films; ethylene-vinyl acetate copolymer films; polystyrene films; polycarbonate films; polymethylpentene films; polysulfone films; polyetheretherketone films; polyethersulfone films; polyetherimide films; fluororesin films; polyamide films; polyimide films; acrylic resin films; polyurethane resin films; norbornene-based polymer films; cyclic olefin-based polymer films; cyclic conjugated diene-based polymer films; vinyl alicyclic hydrocarbon polymer films; and other resin films or laminated films thereof. Among these, polyethylene terephthalate film is preferred from the viewpoint of excellent solvent resistance.

By appropriately adjusting the type of resin film and the condition of the contact surface between the resin film and the base film 12, the peel strength A of the process film 11 against the hard coat film 14 can be adjusted. A release agent layer may be formed on the surface of the process film 11 facing the base film 12 by a peeling treatment.

The thickness of the process film 11 is preferably 10 μm or more, particularly preferably 20 μm or more, and even more preferably 25 μm or more. This provides good rigidity to the hard coat film laminate 1 and improves handling. Furthermore, the thickness of the process film 11 is preferably 500 μm or less, particularly preferably 250 μm or less. This allows each process to be carried out smoothly using a roll-to-roll method.

1.2. Base Film The base film 12 is a base material for forming the hard coat layer 13, and together with the hard coat layer 13, it constitutes the hard coat film 14. The presence of the base film 12 increases versatility, and it becomes possible to provide other functional layers between the base film 12 and the hard coat layer 13.

The base film 12 is preferably formed by applying and curing a curable resin composition (hereinafter sometimes referred to as "base film forming composition"). This allows the base film 12 to be easily formed to a desired thickness, especially as a thin film.

The above curable resin composition may be curable by active energy rays or thermosetting, but it is preferable that it be curable by active energy rays because curing in a high-temperature environment is unnecessary and curing can be completed in a short time. Specifically, it is preferable that the curable resin composition contains an active energy ray curable component, and in particular, it is preferable that it contains a main polymer and an active energy ray curable monomer, and further, it is preferable that it contains a thermoplastic resin as the main polymer, an active energy ray curable monomer and a polymerization initiator.

(1) Curable resin composition (1-1) Thermoplastic resin The thermoplastic resin is not particularly limited, but it is preferable that the resin has heat resistance to the heat drying of the hard coat layer 13 after curing, and is also preferable that it is a resin that can form a thin film. Specifically, it is preferable that the resin has a glass transition temperature (Tg) of 100°C or higher, a resin has a glass transition temperature of 130°C or higher, and a resin has a glass transition temperature of 150°C or higher. There is no particular upper limit to the glass transition temperature (Tg), but it is usually 370°C or lower.

Examples of the resins mentioned above include polyarylate resins, polyethersulfone resins, polysulfone resins, alicyclic hydrocarbon resins, polycarbonate resins, polyimide resins, silicon-based polymer compounds, polyamide resins, polyamide-imide resins, polyphenylene ether resins, polyether ketone resins, polyether ether ketone resins, polyolefin resins, polyester resins, polyphenylene sulfide resins, acrylic resins, aromatic polymers, and the like.

The content of thermoplastic resin in the base film-forming composition is preferably 20% by mass or more, more preferably 25% by mass or more, and even more preferably 30% by mass or more. Furthermore, the content is preferably 95% by mass or less, more preferably 90% by mass or less, and even more preferably 85% by mass or less. By having the thermoplastic resin content within the above range, a film suitable as a support for the hard coat layer 12 can be obtained.

(1-2) Active Energy Ray Curable Monomers Active energy ray curable monomers are preferably (meth)acryloyl group-containing monomers having a (meth)acryloyl group in the molecule. In this specification, (meth)acryloyl means both acryloyl and methacryloyl. The same applies to other similar terms.

(Meth)acryloyl group-containing monomers are preferred because they undergo radical polymerization and curing upon cleavage of the polymerization initiator. Furthermore, (meth)acryloyl group-containing monomers have a relatively small molecular weight and low viscosity, which offers the advantage of reducing the amount of solvent required.

The (meth)acryloyl group-containing monomer may be a monofunctional (meth)acryloyl group-containing monomer or a polyfunctional (meth)acryloyl group-containing monomer. Here, a monofunctional (meth)acryloyl group-containing monomer is a monomer having one (meth)acryloyl group in its molecule, and a polyfunctional (meth)acryloyl group-containing monomer is a monomer having two or more (meth)acryloyl groups in its molecule. Furthermore, a single (meth)acryloyl group-containing monomer may be used alone, or two or more may be used in combination.

As monofunctional (meth)acryloyl group-containing monomers, for example, alkyl (meth)acrylates having 1 to 20 carbon atoms in the alkyl group are preferred. Examples of alkyl (meth)acrylates having 1 to 20 carbon atoms in the alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate, and the like.

Furthermore, preferred monofunctional (meth)acryloyl group-containing monomers include (meth)acrylates having an alicyclic structure within the molecule (alicyclic structure-containing (meth)acrylates) and (meth)acrylates having an aromatic ring within the molecule (aromatic ring-containing (meth)acrylates).

Examples of alicyclic structure-containing (meth)acrylates include cyclohexyl (meth)acrylate, dicyclopentanyl (meth)acrylate, adamantyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate.

Examples of aromatic rings in the above-mentioned aromatic ring-containing (meth)acrylate include benzene rings, naphthalene rings, anthracene rings, biphenyl rings, and fluorene rings, with benzene rings being preferred among them.

Examples of aromatic ring-containing (meth)acrylates include phenyl (meth)acrylate, 2-phenylethyl (meth)acrylate, benzyl (meth)acrylate, naphthyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, phenoxybutyl (meth)acrylate, ethoxylated o-phenylphenol acrylate, phenoxydiethylene glycol (meth)acrylate, and phenoxypolyethylene glycol (meth)acrylate.

In addition to the above, other monofunctional (meth)acryloyl group-containing monomers can also be used, such as alkoxyalkyl (meth)acrylates like methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate; polyoxyalkylene-modified (meth)acrylates; nitrile monomers like acrylonitrile and methacrylonitrile; amide monomers like acrylamide, methacrylamide, N-methylacrylamide, N-methylmethacrylamide, N-N-dimethyl (meth)acrylamide, and N-N-diethyl (meth)acrylamide; and tertiary amino group-containing monomers like N-N-diethylaminoethyl (meth)acrylate and N-(meth)acryloylmorpholine.

As polyfunctional (meth)acryloyl group-containing monomers, monomers having two or more (meth)acryloyl groups in one molecule are preferred. Examples of such monomers include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, neopentyl glycol adipate di(meth)acrylate, hydroxypivalate neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphate di(meth)acrylate, di(acryloxyethyl) isocyanurate, allylated cyclohexyl di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, isocyanurate ethylene oxide-modified diacrylate, bis(acryloxyethyl)hydroxyethyl isocyanurate, and other bifunctional (meth)acryloyl group-containing monomers, as well as trimethylolpropane tri(meth) Trifunctional (meth) acryloyl acrylates, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tris(acryloxyethyl) isocyanurate, ethylene oxide-modified isocyanurate triacrylate, ε-caprolactone-modified tris(acryloxyethyl) isocyanurate, etc. Examples include monomers containing a 3L group, tetrafunctional (meth)acryloyl group-containing monomers such as diglycerin tetra(meth)acrylate and pentaerythritol tetra(meth)acrylate, pentafunctional (meth)acryloyl group-containing monomers such as propionic acid-modified dipentaerythritol penta(meth)acrylate, and hexafunctional (meth)acryloyl group-containing monomers such as dipentaerythritol hexa(meth)acrylate and caprolactone-modified dipentaerythritol hexa(meth)acrylate.

The content of the active energy ray-curable monomer in the base film-forming composition is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more. Furthermore, the content is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less. By having the active energy ray-curable monomer content within the above range, good curability and good flexibility can be obtained.

(1-3) Polymerization initiators The polymerization initiator is not particularly limited as long as it can be cleaved by irradiation with the active energy rays used and polymerize the active energy ray curable monomer. Examples of such polymerization initiators include acylphosphine oxide compounds, benzoin compounds, acetophenone compounds, titanocene compounds, thioxanthone compounds, and peroxide compounds. Specifically, examples include 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzyl diphenyl sulfide, tetramethylthiuram monosulfide, azobisisobutyronitrile, dibenzyl, diacetyl, and β-chloranthraquinone. Among these, 1-hydroxycyclohexyl phenyl ketone is preferred.

The content of the polymerization initiator in the composition for forming the base film is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and even more preferably 0.3% by mass or more. Furthermore, the content is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less. Good curability can be obtained by having the polymerization initiator content within the above range.

The thickness of the base film 12 is preferably 0.5 μm or more, particularly preferably 1 μm or more, and even more preferably 2 μm or more. This allows for the formation of the hard coat layer 12 and other functional layers, and makes it a suitable film as a support for the hard coat layer 12. Furthermore, the thickness of the base film 12 is preferably 15 μm or less, particularly preferably 13 μm or less, even more preferably 10 μm or less, and most preferably 8 μm or less. This allows the hard coat film 11 to be made into a thin film.

The function of the base film 12 is not particularly limited, but it is preferable that it has desired optical properties. For example, the base film 12 is preferably a film having optical isotropy.

1.3. Hard Coat Layer In the hard coat film laminate 1 of this embodiment, the hard coat film 14 is composed of a base film 12 and a hard coat layer 13.

The hard coat layer 13 can be formed by applying a hard coat layer forming coating solution onto the base film 12 and curing it. The coating solution preferably contains an active energy ray curable composition and a solvent. The active energy ray curable composition preferably contains an active energy ray curable component and further preferably contains an inorganic filler, a photopolymerization initiator, etc.

(1) Coating liquid for forming a hard coat layer (1-1) Active energy ray curable component The composition for forming a hard coat layer preferably contains an active energy ray curable component. The active energy ray curable component is not particularly limited as long as it hardens upon irradiation with active energy rays and exhibits the desired hardness.

Specific examples of active energy ray curable components include polyfunctional (meth)acrylate monomers, (meth)acrylate prepolymers, and active energy ray curable polymers, but among these, polyfunctional (meth)acrylate monomers and/or (meth)acrylate prepolymers are preferred. The polyfunctional (meth)acrylate monomers and (meth)acrylate prepolymers may be used individually or in combination.

Examples of polyfunctional (meth)acrylate monomers include tricyclodecanedimethanol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, hydroxypivalate neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphate di(meth)acrylate, allylated cyclohexyl di(meth)acrylate, and isocyanurates. Examples of polyfunctional (meth)acrylates include di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane tri(meth)acrylate, tris(acryloxyethyl) isocyanurate, propionic acid-modified dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate. These may be used individually or in combination of two or more. Among these, tricyclodecanedimethanol di(meth)acrylate or dipentaerythritol hexa(meth)acrylate is preferred.

On the other hand, examples of (meth)acrylate-based prepolymers include polyester acrylate, epoxy acrylate, urethane acrylate, and polyol acrylate prepolymers. A single prepolymer may be used, or two or more may be used in combination.

As the active energy ray curable polymer, for example, a (meth)acrylic acid ester polymer having an active energy ray curable group in its side chain (hereinafter referred to as "active energy ray curable (meth)acrylic acid ester polymer (A)") can be used. The active energy ray curable (meth)acrylic acid ester polymer (A) is preferably obtained by reacting an acrylic polymer (a1) having a functional group-containing monomer unit with an unsaturated group-containing compound (a2) having a substituent bonded to the functional group. As the unsaturated group, for example, a (meth)acryloyl group is a preferred example.

Furthermore, when using two or more active energy ray-curable components, it is preferable that these components have excellent compatibility with one another.

(1-2) Inorganic filler The composition for forming a hard coat layer preferably contains an inorganic filler. The inclusion of an inorganic filler in the composition for forming a hard coat layer makes it easier for the formed hard coat layer to achieve the desired hardness.

Examples of inorganic fillers include powders of silica, alumina, boehmite, talc, calcium carbonate, titanium dioxide, iron oxide, silicon carbide, boron nitride, zirconium oxide, etc., as well as beads formed from these, single crystal fibers, and glass fibers. These can be used individually or in mixtures of two or more. Among these, silica is preferred.

Furthermore, the inorganic filler may be surface-modified. A preferred example of a surface-modified inorganic filler is reactive silica.

In this specification, "reactive silica" refers to silica nanoparticles whose surface has been modified with an organic compound having an active energy ray-curable unsaturated group. These silica nanoparticles (reactive silica), whose surface has been modified with an organic compound having an active energy ray-curable unsaturated group, can be obtained, for example, by reacting the silanol groups on the surface of silica nanoparticles, which typically have an average particle size of about 0.5 to 500 nm, preferably 1 to 200 nm, with an organic compound containing an active energy ray-curable unsaturated group that has a functional group (e.g., isocyanate group, epoxy group, carboxyl group, etc.) that can react with the silanol groups. Examples of the active energy ray-curable unsaturated group include (meth)acryloyl groups and vinyl groups.

Examples of organic compounds containing active energy ray-curable unsaturated groups having functional groups that can react with silanol groups include, for example, general formula (I)

(In the formula, ^R1 is a hydrogen atom or a methyl group, ^R2 is a halogen atom,

(This is the base shown by [the symbol].)
Compounds represented by [the formula shown] are preferably used.

Examples of such compounds include (meth)acrylic acid derivatives such as (meth)acrylic acid, (meth)acrylic acid chloride, (meth)acryloyloxyethyl isocyanate, (meth)acrylic acid glycidyl, (meth)acrylic acid 2,3-iminopropyl, (meth)acrylic acid 2-hydroxyethyl, and acryloyloxypropyltrimethoxysilane. These (meth)acrylic acid derivatives may be used individually or in combination of two or more.

As an organic-inorganic hybrid material (organosilica sol) containing such reactive silica and the aforementioned polyfunctional (meth)acrylate monomer and/or (meth)acrylate prepolymer, for example, products such as "Opstar Z7530," "Opstar Z7524," "Opstar TU4086," and "Opstar Z7537" (all manufactured by JSR Corporation) can be used.

Other examples of preferred inorganic fillers include alumina ceramic nanoparticles, silica sols in which silica fine particles with exposed silanol groups on the silica surface are suspended colloidally in a dispersion medium, and organosilica sols in which the silanol groups on the silica surface are surface-treated with a silane coupling agent or the like.

The inorganic filler content in the hard coat layer forming composition is preferably 20 parts by mass or more, and particularly preferably 40 parts by mass or more, per 100 parts by mass of the active energy ray curable component. Furthermore, the inorganic filler content is preferably 200 parts by mass or less, and particularly preferably 160 parts by mass or less, per 100 parts by mass of the active energy ray curable component. By having an inorganic filler content within the above range, the formed hard coat layer is more likely to achieve the desired hardness.

(1-3) Photopolymerization initiator When ultraviolet light is used as the active energy ray, it is preferable that the hard coat layer forming composition contains a photopolymerization initiator. The photopolymerization initiator is not particularly limited as long as it functions as a photopolymerization initiator for the active energy ray curable component used, and those exemplified as polymerization initiators in the substrate film forming composition can be used.

The content of the photopolymerization initiator in the hard coat layer forming composition is preferably 0.1 parts by mass or more, and particularly preferably 1 part by mass or more, per 100 parts by mass of the active energy ray curable component. Furthermore, the content of the photopolymerization initiator is preferably 20 parts by mass or less, and particularly preferably 5 parts by mass or less, per 100 parts by mass of the active energy ray curable component.

(1-4) Other components The hard coat layer forming composition may contain various additives in addition to the components described above. Examples of various additives include antioxidants, antistatic agents, silane coupling agents, anti-aging agents, thermal polymerization inhibitors, colorants, surfactants, preservatives, plasticizers, lubricants, defoamers, and organic fillers.

(1-5) Solvents The solvent is not particularly limited as long as it can dissolve the components of the hard coat layer forming composition or allow the composition to be uniformly mixed. Examples include ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; aromatic hydrocarbon solvents such as benzene and toluene; ester solvents such as ethyl acetate and butyl acetate; aliphatic hydrocarbon solvents such as n-pentane, n-hexane, and n-heptane; and alicyclic hydrocarbon solvents such as cyclopentane and cyclohexane. These solvents can be used individually or in combination of two or more.

(2) Thickness of the hard coat layer The thickness of the hard coat layer 13 is preferably 0.5 μm or more, particularly preferably 1 μm or more, and even more preferably 1.5 μm or more. This makes it easier for the hard coat film 11 to achieve the desired hardness. The thickness of the hard coat layer is also preferably 20 μm or less, particularly preferably 15 μm or less, even more preferably 10 μm or less, and most preferably 4 μm or less. This makes it possible to thin the hard coat film 14 and suppress the likelihood of cracks occurring.

1.4. Protective Film In this embodiment, the protective film 15 in the hard coat film laminate 1 is laminated on the hard coat layer 13 side of the hard coat film 14. The hard coat film laminate 1 has increased rigidity due to the presence of this protective film 15, and even if the hard coat film 14 is made thin, it will have excellent handling properties. Furthermore, it is possible to process the surface of the hard coat film 14 on the base film 12 side while protecting the hard coat film 14 (hard coat layer 13) from dirt and scratches. For example, an adhesive sheet can be attached to the surface of the hard coat film 14 on the base film 12 side, or other layers can be laminated with good handling properties. The protective film 15 is peeled off when protection of the hard coat film 14 is no longer needed.

The protective film 15 is made of a material that can be attached to the hard coat layer 13 and peeled off from the hard coat layer 13. As the protective film 15, a known type (also called a "protective film") can be used. For example, a self-adhesive resin film or a film comprising a resin film and a slightly adhesive layer is preferably used. From the viewpoint of imparting rigidity to the hard coat film laminate 1, a film comprising a resin film and a slightly adhesive layer is preferred.

As the resin film, for example, the one exemplified as process film 11 can be used. Furthermore, the slightly tacky adhesive layer can be formed using, for example, the materials and thickness disclosed in International Publication WO2020/067488. By appropriately adjusting the type and composition of the adhesive constituting this adhesive layer, the peel strength B of the protective film 15 relative to the hard coat film 14 can be adjusted.

The thickness of the protective film 15 (total thickness of the resin film and adhesive layer) is preferably 10 μm or more, particularly preferably 15 μm or more, and even more preferably 20 μm or more, from the viewpoint of handling and protection of the hard coat film 14. Furthermore, from the viewpoint of handling and cost-effectiveness, the thickness is preferably 500 μm or less, particularly preferably 300 μm or less, and even more preferably 200 μm or less.

[Hard-coated film laminate with adhesive layer]
As shown in Figure 2, the adhesive-layered hard coat film laminate 2 according to this embodiment comprises a base film 12, a hard coat film 14 having a hard coat layer 13 formed on one side of the base film 12, an adhesive layer 17 laminated on the base film side 12 of the hard coat film 14, a release sheet 16 laminated on the side of the adhesive layer 17 opposite to the hard coat film 14 side, and a protective film 15 laminated on the hard coat 13 layer side of the hard coat film 14. The laminate of the adhesive layer 17 and the release sheet 16 constitutes an adhesive sheet 18. This adhesive-layered hard coat film laminate 2 is the same as the hard coat film laminate 1 described above, but with the adhesive sheet 18 laminated in place of the process film 11. The configuration and physical properties other than the adhesive sheet 18 are the same as those of the hard coat film laminate 1 described above.

In the adhesive-layered hard-coat film laminate 2 according to this embodiment, the peel strength C of the release sheet 16 to the adhesive layer 17 is 500 mN/50 mm or less, and the peel strength B of the protective film 15 to the hard-coat film 14 is 50 mN/50 mm or greater than the peel strength C of the release sheet 16 to the adhesive layer 17.

Because the peel strength C of the release sheet 16 against the adhesive layer 17 is within the above range, the release sheet 16 can be easily peeled off from the adhesive layer 17 without damaging the adhesive layer 17, and the subsequent application process can be carried out without problems.

Furthermore, because the relationship between the peel strength B of the protective film 15 against the hard coat film 14 and the peel strength C of the release sheet 16 against the adhesive layer 17 is as described above, the release sheet 16 can be stably peeled off before the protective film 15. This allows subsequent steps, such as peeling off the release sheet 16 and attaching it to the desired substrate via the exposed adhesive layer 17, to be performed with the protective film 15 laminated, thus preventing damage to the hard coat film 14.

The peel strength C of the release sheet 16 to the adhesive layer 17 is preferably 500 mN/50 mm or less, more preferably 300 mN/50 mm or less, more preferably 250 mN/50 mm or less, and even more preferably 200 mN/50 mm or less, from the viewpoint of ease of peeling. On the other hand, the peel strength C of the release sheet 16 to the adhesive layer 17 is preferably 50 mN/50 mm or more, more preferably 80 mN/50 mm or more, and even more preferably 100 mN/50 mm or more. This prevents unintended peeling of the release sheet 16 during each process.

The value obtained by subtracting the peel strength C (mN/50mm) of the release sheet 16 from the adhesive layer 17 from the peel strength B (mN/50mm) of the protective film 15 from the hard coat film 14 (peel strength difference (B-C)) is preferably 50 mN/50mm or more, preferably 80 mN/50mm or more, particularly preferably 100 mN/50mm or more, and even more preferably 150 mN/50mm or more, from the viewpoint of the peeling order described above. On the other hand, a larger peel strength difference (B-C) is better, but is usually 400 mN/50mm or less. This makes it easier to peel only the release sheet 16 from the adhesive layer-attached hard coat film laminate 2.

Below, we will omit explanations of elements that are the same as those in the aforementioned hard coat film laminate 1, and will only explain the different elements.

1. Each Element 1.1. Adhesive Layer The adhesive layer 17 in this embodiment is not particularly limited as long as it can be used to attach the adhesive-layered hard coat film laminate 2 (hard coat film laminate 1) to a desired substrate. As the adhesive constituting the adhesive layer 17, known adhesives such as acrylic adhesives, rubber adhesives, and silicone adhesives can be used. Among these, it is preferable to use an acrylic adhesive from the viewpoint of adhesive strength and optical properties.

The acrylic adhesive preferably has a (meth)acrylic acid ester polymer as its main component, and the (meth)acrylic acid ester polymer is crosslinked with a crosslinking agent. In this specification, the term "polymer" also includes the concept of "copolymer." The (meth)acrylic acid ester polymer preferably contains, as monomer units constituting the polymer, an alkyl (meth)acrylic acid ester for exhibiting good tackiness and a monomer having a reactive functional group that serves as a crosslinking site (a monomer containing a reactive functional group).

As the alkyl (meth)acrylate ester, those with 1 to 20 carbon atoms in the alkyl group are preferred. Examples include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate.

Preferred monomers containing reactive functional groups include monomers having a hydroxyl group in the molecule (hydroxyl group-containing monomers), monomers having a carboxyl group in the molecule (carboxyl group-containing monomers), and monomers having an amino group in the molecule (amino group-containing monomers).

The crosslinking agent can be any agent that reacts with the reactive functional groups of the (meth)acrylic acid ester polymer (A), such as isocyanate-based crosslinking agents, epoxy-based crosslinking agents, amine-based crosslinking agents, etc.

The thickness of the adhesive layer 17 is preferably 0.5 μm or more, particularly preferably 1 μm or more, and even more preferably 2 μm or more. This allows for good adhesive strength. Alternatively, the thickness of the adhesive layer 17 is preferably 50 μm or less, particularly preferably 25 μm or less, and even more preferably 20 μm or less. This prevents the target object (product) obtained by attaching the adhesive-layered hard coat film laminate 2 (hard coat film laminate 1) from becoming too thick.

1.2. Release Sheet A conventionally known release sheet 16 can be used. For example, a release sheet having a release agent layer formed by a release agent treatment on a release sheet substrate can be preferably used.

As a substrate for release sheets, plastic films are preferably used. Examples of such plastic films include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene vinyl acetate film, ionomer resin film, ethylene-(meth)acrylic acid copolymer film, ethylene-(meth)acrylic acid ester copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film, and the like. Alternatively, these may be crosslinked films or laminated films.

Examples of release agents include silicone-based, fluorine-based, alkyd-based, unsaturated polyester-based, polyolefin-based, and wax-based release agents. By appropriately adjusting the type and composition of these release agents, the peel strength C of the release sheet 16 to the adhesive layer 17 can be adjusted.

As an example, a silicone-based release agent can preferably contain an addition-reaction type silicone resin obtained from a first organopolysiloxane having at least two alkenyl groups (e.g., vinyl groups) in one molecule and a second organopolysiloxane (corresponding to a crosslinking agent) having at least two hydrosilyl groups in one molecule, and a silicone resin. As the silicone resin, for example, an MQ resin composed of monofunctional siloxane units [( _CH3 ) _{3SiO1 /2} ] and tetrafunctional siloxane units [SiO4 _/2 ] can be used. In such a silicone-based release agent, the desired release force can be obtained by adjusting the hardness of the release agent layer with the framework of the addition-reaction type silicone resin and adjusting the surface polarity with the amount of silicone resin added.

There are no particular restrictions on the thickness of the release sheet 16, but it is usually around 20 to 150 μm.

Furthermore, the adhesive sheet 18 in this embodiment may be obtained by peeling off the light-peel type release sheet from an adhesive sheet consisting of a light-peel type release sheet, an adhesive layer, and a heavy-peel type release sheet. In that case, the release sheet 16 in this embodiment corresponds to the heavy-peel type release sheet.

[Method for manufacturing hard-coat film laminates]
A method for manufacturing a hard coat film laminate 1 according to one embodiment of the present invention comprises the steps of: forming a base film 12 on a process film 11 (hereinafter sometimes referred to as the "base film forming step"); forming a hard coat layer 13 on the side of the base film 12 opposite to the side facing the process film 11 (hereinafter sometimes referred to as the "hard coat forming step"); and laminating a protective film 15 on the side of the hard coat layer 13 opposite to the side facing the base film 12 (hereinafter sometimes referred to as the "protective film lamination step").

1. Each Step 1.1. Base Film Formation Step In the manufacturing method of the hard coat film laminate 1 according to this embodiment, first, a base film 12 is formed on the process film 11 as shown in Figures 3(a) to (b). In this base film formation step, it is preferable to apply the aforementioned base film forming composition to form a coating film, and then heat-dry and cure the coating film to form the base film 12. The coating can be carried out by a conventional method, for example, by bar coating, knife coating, Meyer bar coating, roll coating, blade coating, die coating, or gravure coating.

The above heating and drying process may be carried out by conventional methods, or it may be done in stages. For example, it is preferable to heat at a relatively low temperature of 30 to 80°C for 0.5 to 3 minutes, and then heat at a relatively high temperature of 80 to 150°C for 0.5 to 3 minutes.

If the base film forming composition is curable by active energy rays, the coating is cured by irradiation with active energy rays to form the base film 12. The irradiation of the coating with active energy rays may be performed from the coating side or from the process film 11 side.

As the active energy beam, for example, electromagnetic waves or charged particle beams that have energy quanta can be used, and specifically, ultraviolet rays and electron beams can be used. Ultraviolet rays are particularly preferred because they are easy to handle. Ultraviolet irradiation can be carried out using high-pressure mercury lamps, xenon lamps, etc. The irradiation dose of ultraviolet rays is preferably about 50 to 1000 mW/ ^cm² . Furthermore, the integrated light dose of ultraviolet rays is preferably 100 to 2000 mJ/ ^cm² , and particularly preferably 500 to 1500 mJ/ ^cm² . On the other hand, electron beam irradiation can be carried out using an electron beam accelerator, etc., and the irradiation dose of the electron beam is preferably 10 to 1000 krad.

1.2. Hard Coat Layer Formation Process In the manufacturing method of the hard coat film laminate 1 according to this embodiment, it is preferable to next apply the aforementioned hard coat layer forming composition onto the base film 12 formed in the above step, as shown in Figure 3(c), to form a coating film, and then heat-dry and harden the coating film to form a hard coat layer 13.

The heat drying of the coating film of the hard coat layer forming composition can be carried out by conventional methods, and it is preferable to heat it at 40 to 120°C for about 30 seconds to 5 minutes.

If the hard coat layer forming composition is curable by active energy rays, the coating film is cured by irradiation with active energy rays to form a hard coat layer 13, and a hard coat film 14 consisting of a base film 12 and a hard coat layer 13 is obtained. The irradiation of the coating film with active energy rays may be performed from the coating film side or from the process film 11 side. The active energy ray irradiation conditions are the same as in the case of the base film forming composition.

Furthermore, before forming the hard coat layer 13 on the base film 12, a desired functional layer, such as a gas barrier layer or an anti-reflective layer, may be formed on the base film 12. In this case, the hard coat layer 13 can be formed on these functional layers.

1.3. Protective Film Lamination Process In the manufacturing method of the hard coat film laminate 1 according to this embodiment, a protective film 15 is then laminated on the hard coat layer 13 formed in the above process, as shown in Figure 3(d). The protective film 15 can be laminated using a known laminator or the like.

In the manufacturing method of the hard coat film laminate 1 according to this embodiment, since the process film 11 is laminated on the hard coat film 14, the laminate has a certain degree of rigidity even when the hard coat film 14 is a thin film. Therefore, the protective film lamination process can be carried out with good handling properties. Furthermore, the hard coat film laminate 1 obtained by laminating the protective film 15 has improved rigidity and thus has excellent handling properties.

2. Physical Properties In the hard coat film laminate 1 manufactured by the manufacturing method of the hard coat film laminate according to this embodiment, the peel strength A of the process film 11 to the hard coat film 14 is 500 mN/50 mm or less, the peel strength B of the protective film 15 to the hard coat film 14 is 500 mN/50 mm or less, and the peel strength B of the protective film 15 to the hard coat film 14 is 50 mN/50 mm or greater than the peel strength A of the process film 11 to the hard coat film 14. Details of these physical properties are as described above for the hard coat film laminate 1.

[Method for manufacturing a hard-coat film laminate with an adhesive layer]
The method for manufacturing the adhesive-layered hard coat film laminate 2 according to this embodiment comprises the steps of: forming a base film 12 on a process film 11 (base film formation step); forming a hard coat layer 13 on the side of the base film 12 opposite to the side facing the process film 11 (hard coat formation step); laminating a protective film 15 on the side of the hard coat layer 13 opposite to the side facing the base film 12 (protective film lamination step); peeling the process film 11 from the base film 12 to expose the base film 12 (this may be referred to as the "process film peeling step"); and attaching the adhesive layer 17 side of an adhesive sheet 18 having an adhesive layer 17 and a release sheet 16 to the exposed base film 12 (this may be referred to as the "adhesive sheet attachment step").

The method for manufacturing the adhesive-layered hard coat film laminate 2 according to this embodiment is the same as the method for manufacturing the hard coat film laminate 1 described above, up to the protective film lamination step. The subsequent steps will be described below.

1. Each Step 1.4. Process Film Peeling Step In the manufacturing method of the adhesive layer-attached hard coat film laminate 2 according to this embodiment, as shown in Figures 4(d) to (e), the process film 11 is peeled off from the base film 12 of the hard coat film 14 in the hard coat film laminate 1 manufactured through the steps described above, exposing the base film 12. This makes it possible to process the hard coat film 14 onto the base film 12. The peeling off of the process film 11 can be done using a known laminator or the like. In this embodiment, as will be described later, an adhesive sheet 18 is attached to the hard coat film 14 to manufacture an adhesive layer-attached hard coat film laminate.

1.5. Adhesive Sheet Application Process In the manufacturing method of the adhesive-layered hard coat film laminate 2 according to this embodiment, the adhesive layer 17 side of an adhesive sheet 18 having an adhesive layer 17 and a release sheet 16 is then applied to the exposed base film 12, as shown in Figure 4(f), to obtain the adhesive-layered hard coat film laminate 2. The adhesive sheet 18 can be applied using a known laminator or the like.

The hard coat film laminate 1 has a protective film 15 laminated on a hard coat film 14, so even if the hard coat film 14 is a thin film, the laminate has a certain degree of rigidity. Therefore, the above-mentioned film peeling step and adhesive sheet application step can be carried out with good handling.

The resulting adhesive-coated hard-coat film laminate 2 can be bonded to a desired substrate via the adhesive layer 17 by peeling off the release sheet 16 of the adhesive sheet 18. The protective film 15 is then peeled off when it is no longer needed. The peeling of the release sheet 16 and the protective film 15 can be performed using a known peeling device or a laminator with a peeling function.

2. Physical Properties In the adhesive-layered hard coat film laminate 2 manufactured by the manufacturing method of the adhesive-layered hard coat film laminate according to this embodiment, the peel strength A of the process film 11 to the hard coat film 14 is 500 mN/50 mm or less, the peel strength B of the protective film 15 to the hard coat film 14 is 500 mN/50 mm or less, the peel strength C of the release sheet 16 to the adhesive layer 17 is 500 mN/50 mm or less, the peel strength B of the protective film 15 to the hard coat film 14 is 50 mN/50 mm or more greater than the peel strength A of the process film 11 to the hard coat film 14, and the peel strength B of the protective film 15 to the hard coat film 14 is 50 mN/50 mm or more greater than the peel strength C of the release sheet 16 to the adhesive layer 17. Details of these physical properties are as described above for the hard coat film laminate 1 and the adhesive-layered hard coat film laminate 2.

3. Applications The adhesive layer-attached hard coat film laminate 2 (and hard coat film laminate 1) according to this embodiment can be used for various applications. The hard coat film 14 is preferably used as an optical film, and is particularly preferably used as an optical film having optical isotropy. Specific examples of optical films include protective films, shatterproof films, and anti-glare films. These optical films can be used, for example, by attaching them to various displays such as liquid crystal displays (LCDs), plasma displays (PDPs), organic electroluminescent displays (OLEDs), and touch panels, as well as to desired optical components in organic electroluminescent lighting and organic photovoltaic displays (OPVs).

The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit it. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

For example, a functional layer such as a gas barrier layer or an anti-reflective layer may be provided between the base film 12 and the hard coat layer 13 in the hard coat film 14.

The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[Manufacturing Example 1] (Preparation of composition for forming a base film)
The following thermoplastic resins (A) (A1) to (A6) were dissolved in solvents (s) (s1) to (s6), respectively. Then, active energy ray curable monomers (B) and polymerization initiators (C) were mixed into these solutions in the amounts (based on solid content) shown in Table 1 to prepare base film forming compositions f1 to f6.

(A) Thermoplastic resin (A1) Polyarylate resin: Manufactured by Unitika Corporation, product name "U Polymer P-1001A", Tg = 195°C
(A2) Polyethersulfone resin: BASF Corporation, product name "ULTRASON E 2010", Tg = 225°C
(A3) Polysulfone resin (PSF): Manufactured by BASF, product name "ULTRASON S 3010", Tg = 180°C
(A4) Alicyclic hydrocarbon resin: Manufactured by Polyplastics Co., Ltd., product name "TOPAS 6017", Tg = 180°C
(A5) Polycarbonate resin: Manufactured by Idemitsu Kosan Co., Ltd., product name "Toughlon LS1700", Tg = 145℃
(A6) Polyimide resin: Manufactured by Kawamura Sangyo Co., Ltd., product name "KPI-MX300F", Tg = 354°C

(s) Solvent (s1) Dichloromethane (s2) Dichloromethane (s3) 1,3-Dioxolane (s4) Toluene (s5) Toluene (s6) Methyl ethyl ketone

(B) Active energy ray curable monomer (B1) Acryloylmorpholine: Manufactured by Kojinsha, product name "ACMO"
(B2) Phenoxypolyethylene glycol acrylate: Manufactured by Osaka Organic Chemical Industry Co., Ltd., product name "V#192"
(B3) Benzyl acrylate: Manufactured by Osaka Organic Chemical Industry Co., Ltd., product name "V#160"
(B4) Cyclohexyl acrylate: Manufactured by Osaka Organic Chemical Industry Co., Ltd., product name "V#155"
(B5) Ethoxylated o-phenylphenol acrylate: Manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product name "A-LEN-10"
(B6) Ethoxylated bisphenol A diacrylate: Manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product name "ABE-300"
(B7) Tricyclodecanedimethanol diacrylate: Manufactured by Shin-Nakamura Chemical Industry Co., Ltd., product name "ADCP"

(C) Polymerization initiator (C1) 1-hydroxycyclohexylphenyl ketone: Manufactured by BASF, product name "Irgacure 184"

[Manufacturing Example 2] (Production of adhesive sheets)
90 parts by mass of butyl acrylate and 10 parts by mass of acrylic acid were added to the reactor as monomer components, and 0.2 parts by mass of azobisisobutyronitrile was added as a polymerization initiator and mixed. Subsequently, the mixture was degassed with nitrogen gas for 4 hours, and the temperature was gradually raised to 60°C. The polymerization reaction was then carried out with stirring for 24 hours to obtain a (meth)acrylic acid ester polymer (Mw: 650,000).

To 100 parts by mass (based on solid content; the same applies hereafter) of the obtained (meth)acrylic acid ester polymer, 1.5 parts by mass of trimethylolpropane-modified tolylene diisocyanate (manufactured by Nippon Polyurethane Co., Ltd., product name "Coronate L") was added as an isocyanate-based crosslinking agent. This was dissolved in toluene to prepare an adhesive coating solution with a solid content concentration of 20% by mass.

The adhesive solution described above was applied to the release-treated surface of a double-peel release sheet, a PET film (Lintec Corporation, product name "SP-PET38T103-1", thickness: 38 μm) with one side treated with a silicone release agent, to form a coating film. The coating film was heated and dried at 120°C for 2 minutes to form an adhesive layer with a thickness of 5 μm.

Next, the release-treated side of a PET film (Lintec Corporation, product name "SP-PET381130", thickness: 38 μm), which is a light-peel release sheet with one side treated with a silicone release agent, was attached to the adhesive layer, thereby creating an adhesive sheet in which the adhesive layer was sandwiched between two release sheets.

[Example 1]
Hard coat film laminates and hard coat film laminates with adhesive layers were manufactured using the following procedure. Subsequently, the obtained hard coat film laminates with adhesive layers were attached to a glass plate (simulated device) to produce test samples.

<Hard coat film laminate>
As the process film, a polyethylene terephthalate (PET) film with one side easily bonded (manufactured by Toyobo Co., Ltd., product name "Cosmoshine PET50A-4100", thickness: 50 μm) was prepared.

The base film-forming composition f1 prepared in Production Example 1 was applied to the non-adhesive surface of the PET film using an applicator. The coating was heated at 50°C for 2 minutes, followed by heating at 130°C for 2 minutes, and then dried.

Next, using a belt conveyor type ultraviolet irradiation device (manufactured by iGraphix, product name "ECS-401GX"), the above coating film was irradiated with ultraviolet light of a wavelength of 365 nm using a high-pressure mercury lamp (manufactured by iGraphix, product name "H04-L41") under a nitrogen atmosphere, at an irradiance of 200 mW/ ^cm² and an integrated light amount of 1400 mJ/ ^cm² , and cured. In this way, a base film with a thickness of 5 μm was formed on the process film.

On the substrate film formed as described above, a composition containing an ultraviolet-curable component, an inorganic filler, and a photopolymerization initiator (manufactured by Arakawa Chemical Industries, Ltd., product name "Opstar Z7530", ultraviolet-curable component: dipentaerythritol hexaacrylate, inorganic filler: reactive silica, inorganic filler content: 49% by volume, photopolymerization initiator content: 3% by mass, solids concentration: 73% by mass, solvent: methyl ethyl ketone) was applied by gravure coating as a hard coat layer forming composition. The coating film was heated at 100°C for 90 seconds and dried.

Next, using a belt conveyor type ultraviolet irradiation device (manufactured by iGraphix, product name "ECS-401GX"), the above coating film was irradiated with ultraviolet light of a wavelength of 365 nm using a high-pressure mercury lamp (manufactured by iGraphix, product name "H04-L41") under a nitrogen atmosphere, at an irradiance of 200 mW/ ^cm² and an integrated light amount of 1400 mJ/ ^cm² , and cured. In this way, a hard coat layer with a thickness of 2 μm was formed on the substrate film.

Next, a protective film (Lintec Corporation, product name "SRL-1254") was laminated onto the hard coat layer using a laminating device equipped with rollers (manufactured by Japan Office Laminator Co., Ltd., product name "Roll-type Multi-Laminator"). The lamination conditions were a temperature of 23°C, a pressure of 0.2 MPa, and a speed of 2.0 m/min. The protective film consisted of a PET film with a thickness of 125 μm, to which a slightly tacky acrylic adhesive layer was laminated on one side.

As described above, a hard coat film laminate was manufactured by laminating a protective film, a hard coat film (hard coat layer + base film), and a process film in that order from top to bottom.

<Hard-coated film laminate with adhesive layer>
The process film was peeled off the hard coat film (base film) of the obtained hard coat film laminate using a laminating device (manufactured by Japan Office Laminator Co., Ltd., product name "Roll-type Multi-Laminator").

Next, the easily removable release sheet was peeled off from the adhesive sheet produced in Manufacturing Example 2, and the exposed adhesive layer was attached to the hard coat film (base film) of the hard coat film laminate. The same laminating apparatus as described above was used to attach this adhesive sheet.

As described above, a laminated hard coat film with an adhesive layer was manufactured by laminating a protective film, a hard coat film (hard coat layer + base film), and an adhesive sheet (adhesive layer + double-peel release sheet) in that order from top to bottom.

<Test Sample>
A heavy-peel release sheet was peeled off the adhesive layer of the hard-coat film laminate with an adhesive layer using a laminating device (manufactured by Japan Office Laminator Co., Ltd., product name "Roll-type Multi-Laminator"). Next, the exposed adhesive layer was laminated to a glass plate (manufactured by Corning, product name "Eagle XG") as a pseudo-device using the same laminating device.

Finally, the protective film was peeled off the hard coat film (hard coat layer) using a laminating device (manufactured by Japan Office Laminator Co., Ltd., product name "Roll-type Multi-Laminator"), and a test sample was obtained in which the adhesive-coated hard coat film laminate was attached to a glass plate (simulated device).

[Example 2]
A hard coat film laminate, a hard coat film laminate with an adhesive layer, and a test sample were manufactured in the same manner as in Example 1, except that the base film forming composition f1 was replaced with the base film forming composition f2.

[Example 3]
A hard coat film laminate, a hard coat film laminate with an adhesive layer, and a test sample were manufactured in the same manner as in Example 1, except that the base film forming composition f1 was replaced with the base film forming composition f3.

[Example 4]
A hard coat film laminate, a hard coat film laminate with an adhesive layer, and a test sample were manufactured in the same manner as in Example 1, except that the base film forming composition f1 was replaced with the base film forming composition f4.

[Example 5]
A hard coat film laminate, a hard coat film laminate with an adhesive layer, and a test sample were manufactured in the same manner as in Example 1, except that the base film forming composition f1 was replaced with the base film forming composition f5.

[Example 6]
A hard coat film laminate, a hard coat film laminate with an adhesive layer, and a test sample were manufactured in the same manner as in Example 1, except that the base film forming composition f1 was replaced with the base film forming composition f6.

[Comparative Example 1]
As the process film, a PET film with one side easily bonded (manufactured by Toyobo Co., Ltd., product name "Cosmoshine PET50A-4100", thickness: 50 μm) was prepared, the same as in Example 1.

Except for forming a base film on the easily bonded surface of the PET film described above, a hard coat film laminate, a hard coat film laminate with an adhesive layer, and a test sample were manufactured in the same manner as in Example 1.

[Comparative Example 2]
Hard coat film laminates, hard coat film laminates with adhesive layers, and test samples were manufactured in the same manner as in Example 1, except that the protective film (Lintec Corporation, product name "SRL-1254") was changed to a protective film (Lintec Corporation, product name "SRL-1258").

[Comparative Example 3]
Hard coat film laminates, hard coat film laminates with adhesive layers, and test samples were manufactured in the same manner as in Example 1, except that the protective film (Lintec Corporation, product name "SRL-1254") was replaced with a protective film (Sanei Chemicals Co., Ltd., product name "Sunnytect PAC3-60T").

[Test Example 1] (Measurement of peel strength)
(1) Measurement of peel strength A The hard coat film laminates obtained in the above examples and comparative examples were cut to a width of 50 mm and a length of 150 mm, and the protective film side was fixed to a stainless steel plate with double-sided adhesive tape. Next, using a tensile testing machine (manufactured by Orientec Co., Ltd., product name "Tensilon"), the peel strength (peel strength A; mN/50 mm) when the process film was peeled from the hard coat film base film was measured under conditions of a peel speed of 10 m/min and a peel angle of 180 degrees. Measurements other than those described herein were performed in accordance with JIS Z0237:2009. The results are shown in Table 2.

(2) Measurement of peel strength B The hard coat film laminates obtained in the above examples and comparative examples were cut to a width of 50 mm and a length of 150 mm, and the process film was peeled off. The exposed hard coat film side facing the base film was then fixed to a stainless steel plate with double-sided adhesive tape. Next, the test was performed in the same manner as above, and the peel strength (peel strength B; mN/50 mm) when the protective film was peeled off from the hard coat layer of the hard coat film was measured. The results are shown in Table 2.

(3) Measurement of peel strength C The adhesive-coated hard coat film laminates obtained in the above examples and comparative examples were cut to a width of 50 mm and a length of 150 mm, and the protective film side was fixed to a stainless steel plate with double-sided adhesive tape. Then, the test was performed in the same manner as above, and the peel strength (peel strength C; mN/50 mm) when the release sheet was peeled from the adhesive layer was measured. The results are shown in Table 2. Note that in Comparative Example 1, a problem occurred at the stage when the process film was peeled off, so the peel strength C was not measured.

(4) Calculation of the difference in peel strength Based on the peel strengths A to C measured in (1) to (3) above, the difference in peel strength (B-A) was calculated by subtracting peel strength A from peel strength B, and the difference in peel strength (B-C) was calculated by subtracting peel strength C from peel strength B. The results are shown in Table 2.

[Test Example 2] (Process Evaluation)
The protective film was peeled off the test samples prepared in the examples and comparative examples. The exposed hard coat film was visually inspected.
(1) We checked whether cracks had occurred in the hard coat film (hard coat layer/base film) and (2) whether deformation had occurred in the hard coat film (hard coat layer/base film). If no cracks/deformation were found, it was marked as "none," and if cracks/deformation were found, it was marked as "present." The results are shown in Table 2.

Furthermore, in the process of manufacturing test samples in the examples and comparative examples,
(3) We checked for any process defects, especially whether there was any unintended delamination between layers. If there were no process defects, it was marked as "None," and if there were defects such as unintended delamination, it was marked as "Yes." The results are shown in Table 2.

Further details regarding Comparative Example 1 (*1) and Comparative Example 3 (*2) in Table 2 are as follows.
*1: In the process of peeling off the process film, peeling occurred at the interface between the protective film and the hard coat layer.
*2: In the process of peeling off the process film and the process of peeling off the release sheet, peeling occurred at the interface between the protective film and the hard coat layer.

As can be seen from Table 2, the hard coat film laminates, hard coat laminates with adhesive layers, and hard coat films attached to simulated devices in the examples did not exhibit any cracks or deformation in the hard coat film during the manufacturing process, nor did any unintended peeling or other defects between layers. In other words, the hard coat film laminates and hard coat laminates with adhesive layers manufactured in the examples exhibited excellent handling properties.

The hard-coat film laminate and the hard-coat film laminate with an adhesive layer according to the present invention can be suitably used in optical applications requiring a hard-coat film.

1 Hard coat film laminate 2 Hard coat film laminate with adhesive layer 11 Process film 12 Base film 13 Hard coat layer 14 Hard coat film 15 Protective film 16 Release sheet 17 Adhesive layer 18 Adhesive sheet

Claims (9)

A hard coat film having a base film and a hard coat layer formed on one side of the base film,
A process film laminated on the substrate film side of the hard coat film,
A hard coat film laminate comprising a protective film laminated on the hard coat layer side of the hard coat film,
The peel strength A of the process film relative to the hard coat film is 500 mN/50 mm or less.
The peel strength B of the protective film relative to the hard coat film is 500 mN/50 mm or less.
The value obtained by subtracting the peel strength A of the process film from the peel strength B of the protective film from the peel strength B of the hard coat film is 50 mN/50 mm or more and 400 mN/50 mm or less.
A hard-coat film laminate characterized by the following features. The hard coat film laminate according to claim 1, characterized in that the peel strength A of the process film relative to the hard coat film is 50 mN/50 mm or more. The hard coat film laminate according to claim 1 or 2, characterized in that the peel strength B of the protective film relative to the hard coat film is 200 mN/50 mm or more. The hard coat film laminate according to any one of claims 1 to 3, characterized in that the thickness of the base film in the hard coat film is 0.5 μm or more and 15 μm or less. The hard coat film laminate according to any one of claims 1 to 4, characterized in that the base film in the hard coat film has optical isotropy. A hard coat film having a base film and a hard coat layer formed on one side of the base film,
An adhesive layer laminated on the substrate film side of the hard coat film,
A release sheet laminated on the side of the adhesive layer opposite to the side facing the hard coat film,
A hard coat film laminate with an adhesive layer, comprising a protective film laminated on the hard coat layer side of the hard coat film,
The peel strength B of the protective film relative to the hard coat film is 500 mN/50 mm or less.
The peel strength C of the release sheet with respect to the adhesive layer is 500 mN/50 mm or less.
The value obtained by subtracting the peel strength C of the release sheet from the peel strength B of the protective film to the hard coat film is 50 mN/50 mm or more and 400 mN/50 mm or less.
A hard-coated film laminate with an adhesive layer, characterized by the above. The adhesive-layered hard-coat film laminate according to claim 6, characterized in that the peel strength C of the release sheet against the adhesive layer is 50 mN/50 mm or more. A process of forming a base film on a process film,
A step of forming a hard coat layer on the side of the base film opposite to the side facing the process film,
A method for manufacturing a hard coat film laminate, comprising the step of laminating a protective film on the side of the hard coat layer opposite to the side facing the base film, wherein the laminate including the base film and the hard coat layer constitutes a hard coat film,
The peel strength A of the process film relative to the hard coat film is 500 mN/50 mm or less.
The peel strength B of the protective film relative to the hard coat film is 500 mN/50 mm or less.
A method for manufacturing a hard coat film laminate, characterized in that the peel strength B of the protective film with respect to the hard coat film is 50 mN/50 mm or greater than the peel strength A of the process film with respect to the hard coat film. A process of forming a base film on a process film,
A step of forming a hard coat layer on the side of the base film opposite to the side facing the process film,
A step of laminating a protective film on the side of the hard coat layer opposite to the side facing the substrate film,
A step of peeling the process film from the base film to expose the base film,
A method for manufacturing a hard coat film laminate with an adhesive layer, comprising the steps of: attaching the adhesive layer side of an adhesive sheet having an adhesive layer and a release sheet to the exposed base film, wherein the laminate including the base film and the hard coat layer constitutes a hard coat film,
The peel strength A of the process film relative to the hard coat film is 500 mN/50 mm or less.
The peel strength B of the protective film relative to the hard coat film is 500 mN/50 mm or less.
The peel strength C of the release sheet with respect to the adhesive layer is 500 mN/50 mm or less.
The peel strength B of the protective film relative to the hard coat film is 50 mN/50 mm or greater than the peel strength A of the process film relative to the hard coat film.
A method for manufacturing a hard coat film laminate with an adhesive layer, characterized in that the peel strength B of the protective film with respect to the hard coat film is 50 mN/50 mm or greater than the peel strength C of the release sheet with respect to the adhesive layer.