WO2009081556A1

WO2009081556A1 - Multilayer sheet and optical recording medium

Info

Publication number: WO2009081556A1
Application number: PCT/JP2008/003853
Authority: WO
Inventors: Kahoru Niimi
Original assignee: Mitsubishi Plastics, Inc.
Priority date: 2007-12-26
Filing date: 2008-12-19
Publication date: 2009-07-02

Abstract

Disclosed is a multilayer sheet which does not cause warp in a disk when used in optical disks or the like. Specifically disclosed is a multilayer sheet having a structure wherein a hard coat layer is arranged on at least one side of a film layer. The multilayer sheet is characterized in that each layer is composed of an active energy ray-curable resin composition and has the following characteristics (A)-(D). (A) The storage modulus at 25˚C is not less than 2000 MPa. (B) The glass transition temperature as the maximum value of loss tangent of the active energy ray-curable resin composition of the film layer is not more than 90˚C. (C) The storage modulus at 100˚C is not more than 100 MPa. (D) The tensile elongation at break at 80˚C is not less than 4%.

Description

Laminated sheet and optical recording medium

The present invention is transparent, optically less distorted, has toughness, heat resistance, scratch resistance, and excellent secondary processing. When forming a part of a layer such as a window, display, optical recording medium, etc. The present invention relates to a suitably usable laminated sheet and an optical recording medium formed using the sheet.

In recent years, plastic films with small optical distortion have been frequently used and applied in optical products such as displays, electronic devices, and information recording members. The required performance for such a sheet includes not only the property of optically less distortion but also resistance to moist heat deformation, adhesion to an adherend, and non-contamination. Especially in the field of advanced technology such as high-precision parts and optical disks, reliability under severe environmental conditions such as high temperature and high humidity is often required, but films used for these applications are cast and coated. Most of them are formed by a method or the like, and materials are also limited to those suitable for the processing method. For this reason, the above-mentioned film has not been reconciled with heat-and-moisture resistance, processability, cost, and the like, and the actual situation is that the film is severely restricted in terms of use and use conditions.

For example, Patent Document 1 discloses the superiority of a coating method, particularly a spin coater method, as a method for processing an active energy ray-curable resin composition.

Patent Document 2 discloses a sheet with a pressure sensitive adhesive using a UV curable acrylic resin.

Furthermore, Patent Document 3 can impart excellent scratch resistance, water resistance and chemical resistance to image paper such as photographs output by a printer and the surface of a display, etc., and there is little distortion and image sharpness. The adhesive sheet with a hard coat which hardened urethane acrylate which can improve thickness and can further reduce thickness is described.

JP 2003-231725 A JP 2006-330714 A International Publication No. 2004/083330 Pamphlet

In the invention described in Patent Document 1, when obtaining a film having a thickness of about 50 to 100 μm, these methods are not only sufficient in thickness accuracy but also due to scattering of the active energy ray-curable resin composition used. The loss is large and it is hard to say that it is practical.

In addition, the sheet with pressure-sensitive adhesive described in Patent Document 2 is not designed in consideration of surface hardness and contamination resistance in the embodiment, and is not practical.

Furthermore, the pressure-sensitive adhesive sheet with a hard coat described in Patent Document 3 has a total thickness of 50 μm or less, and lacks self-sustainability, so it is necessary to provide protective films on both sides, and it cannot be said that productivity is good and is practical. It was hard to say.

Therefore, the present invention is transparent, has small optical distortion, has good film-forming properties, is excellent in secondary workability, and can be both self-supporting and flexible as a sheet. Is to provide a laminated sheet that does not warp the disc, an optical disc formed using the laminated sheet, particularly a high-density recording medium of a next-generation disc, for example, an optical recording medium such as a Blu-ray disc, UDO, etc. And

As a result of intensive studies to solve these problems, the present inventor forms a laminated sheet when a laminated sheet made of a cured product of an active energy ray-curable resin composition is bonded to an optical disk or the like and used as a protective sheet. Since the cured product of the active energy ray-curable resin composition acts as a stress that relaxes and shrinks at high temperatures, the wet sheet has a large dimensional change in wet heat, and the warp that occurs on the optical disk when bonded to the optical disk in the operating temperature range. Clarified that is remarkable.

Accordingly, the present inventors have conducted further diligent studies to obtain a laminated sheet having a configuration in which a hard coat layer is laminated on at least one surface of a film layer, and the laminated sheet having the configuration is described below as (A) to By having the physical properties of (D), shrinkage stress can be reduced, and even if processed into a film, problems such as brittleness and breakage, lack of waist and difficulty in handling are not caused, and film forming properties are good. It has been found that it is excellent in secondary workability and can be both self-supporting and flexible as a sheet.
(A) Storage elastic modulus at 25 ° C. is 2000 MPa or more (B) Glass transition temperature as maximum of loss tangent of active energy ray-curable resin composition of film layer is 90 ° C. or lower (C) Storage elastic modulus at 100 ° C. Is 100 MPa or less (D) Elongation at break at 80 ° C. is 4% or more

In addition, the inventor of the present invention provides a laminated sheet having a configuration in which a hard coat layer, a film layer, and an adhesive material layer are sequentially laminated, with the total thickness of the laminated sheet being 70 to 200 μm or less, and an adhesive material for the film layer. By setting the thickness ratio of the layer to 10 to 50% and the thickness ratio of the hard coat layer to the film layer to 1 to 5%, it is possible to remarkably suppress the occurrence of warping that occurs on the optical disc, and to improve the film forming property. Yes, it was found that it was excellent in secondary workability, and both the self-supporting property and flexibility as a sheet could be achieved.

In this case, if the laminated sheet has a property that the storage elastic modulus at 25 ° C. is 1000 MPa or more and the storage elastic modulus at 80 ° C. is 100 MPa or less, the effect of reducing the stress can be exerted and processed into a film shape. It was also found that problems such as fragility and fragility, lack of waist and difficulty in handling did not occur.

That is, the present invention relates to the following [1] to [10].

[1] A laminated sheet having a configuration in which a hard coat layer is laminated on at least one surface of a film layer, each layer comprising an active energy ray-curable resin composition, and the following (A) to ( A laminated sheet having the property of D).
(A) Storage elastic modulus at 25 ° C. is 2000 MPa or more (B) Glass transition temperature as maximum of loss tangent of active energy ray-curable resin composition of film layer is 90 ° C. or lower (C) Storage elastic modulus at 100 ° C. Is 100 MPa or less (D) Elongation at break at 80 ° C. is 4% or more

[2] The laminated sheet according to [1], wherein the total thickness of the laminated sheets is 70 to 200 μm or less, and the thickness ratio of the hard coat layer to the film layer is 1 to 5%.

[3] A laminated sheet having a structure in which a hard coat layer, a film layer, and an adhesive material layer are sequentially laminated, each layer comprising an active energy ray-curable resin composition, and the total thickness of the laminated sheet is 70 to A laminated sheet having a thickness of 200 μm or less, a thickness ratio of the adhesive layer to the film layer of 10 to 50%, and a thickness ratio of the hard coat layer to the film layer of 1 to 5%.

[4] The laminated sheet according to [3], wherein the storage elastic modulus at 25 ° C. is 1000 MPa or more and the storage elastic modulus at 80 ° C. is 100 MPa or less.

[5] The laminated sheet according to any one of [1] to [4], wherein the film layer comprises a composition containing the compounds shown in the following (1) to (6).
(1) 20 to 60 parts by mass of a urethane (meth) acrylate oligomer represented by the following [Chemical Formula 1]

(In the formula, m represents an integer of 1 to 4, and n represents an integer of 1 to 10.)
(2) 10 to 60 parts by mass of a monomer having an alkylene oxide group and at least two (meth) acryloyl groups (3) 10 to 50 parts by mass of a monomer having one (meth) acryloyl group and an aromatic ring structure in the molecule ( 4) Monomer having 1 (meth) acryloyl group and alicyclic structure in the molecule 0 to 20 parts by mass (5) Epoxy (meth) acrylate 0 to 20 parts by mass (6) Photopolymerization initiator 0.1 to 10 parts by mass Part

[6] The laminated sheet according to any one of [1] to [5], wherein the hard coat layer is composed of a composition containing the compounds shown in the following (1) to (4).
(1) A polymer containing at least one (meth) acryloyloxy group in the side chain and a structure represented by the following [Chemical Formula 2] and / or at least one (meth) acryloyloxy group in the molecule, and a fluoroalkylene oxide group 5 to 20 parts by mass of a polymer having

(However, n represents an integer of 5 to 100.)
(2) 30 to 60 parts by mass of a monomer containing at least three (meth) acryloyl groups in the molecule (3) 0 to 20 parts by mass of a monomer having one (meth) acryloyl group and a ring structure in the molecule (4) Photopolymerization initiator 0.1 to 10 parts by mass

[7] The laminated sheet according to any one of [3] to [6], wherein the pressure-sensitive adhesive layer is composed of a composition containing the following compounds (1) to (3).
(1) Urethane (meth) acrylate having a skeleton of the following [Chemical Formula 3], an average number of functional groups per molecule of 1 to 2, and a molecular weight of 10,000 or more, 50 to 90 parts by mass

(In the formula, R ₁ is an alkyl group having 4 or more carbon atoms, R ₂ is an aliphatic isocyanate compound residue, R ₃ is a polyol residue having a molecular weight of 300 or more, and R ₄ is hydrogen or an alkyl acrylate having 4 or more carbon atoms. Represents a group.)
(2) 10 to 50 parts by mass of a compound having one (meth) acryloyl group and an aliphatic structure having 4 or more carbon atoms in the molecule (3) 1 to 10 parts by mass of a photopolymerization initiator

[8] The laminated sheet according to any one of [5] to [7], wherein the photopolymerization initiator is an α-hydroxyacetophenone derivative or a benzophenone derivative having a molecular weight of 300 or more.

[9] A protective film for optical disks comprising the laminated sheet according to any one of [1] to [8].

[10] An optical recording medium obtained by laminating at least one laminated sheet according to any one of [1] to [8].

In the present invention, the storage elastic modulus is a value of elastic modulus at a predetermined temperature measured by a dynamic viscoelasticity measurement method (JIS K7244-4) at a frequency of 10 Hz and a strain of 0.1%, and is a glass transition. The temperature refers to the temperature at the maximum value of the loss tangent (Tan δ) measured by the same measurement method. The tensile breaking elongation is applied to one or both of the flow direction (MD) and the direction (TD) perpendicular to the flow direction during film formation.

According to the present invention, it is transparent and has a small optical distortion, and even when processed into a film shape, it does not cause problems such as brittleness and breakage, lack of waist and difficulty in handling, and has good film-forming properties. An optical recording medium excellent in processability and capable of providing a laminated sheet that does not cause warpage even when used by being bonded to an optical disk or the like, and is obtained by laminating the laminated sheet having these properties In addition to the above-mentioned excellent optical and mechanical properties, it has excellent lamination convenience, thickness accuracy and cost, and its added value is extremely high industrially and commercially. In particular, it is suitable for forming at least one layer of a high-density recording medium of a next-generation type disc, for example, an optical disc such as a Blu-ray disc or UDO.

(First form)
The laminated sheet of the first aspect of the present invention is a laminated sheet having a configuration in which a hard coat layer is laminated on at least one surface of a film layer, each layer comprising an active energy ray-curable resin composition, The laminate sheet is not particularly limited as long as it has the following properties, and the laminated sheet has the following properties (A) to (D), that is, has a high elastic modulus near room temperature and becomes soft at high temperatures. By maintaining a moderate elongation in a high temperature range, shrinkage stress can be reduced, and even when processed into a film, problems such as brittleness and breakage, lack of waist and difficulty in handling are not caused. . More specifically, by setting the glass transition temperature of the active energy ray-curable resin composition of the film layer constituting the laminated sheet to 90 ° C. or less, various engineer plastics such as polycarbonate (glass transition temperature 150 ° C.) and PMMA (polyethylene When bonded to a resin substrate such as methyl methacrylate (glass transition temperature 105 ° C.), the sheet follows the dimensional change in the heat-resistant temperature range of the adherend, and the adherend and the laminated sheet of the present invention Effectively relieves strain (dimensional change) that occurs in the meantime. At this time, the hard coat layer provided on the surface is designed to maintain an appropriate surface hardness even in a high temperature range (the glass transition temperature is higher than 90 ° C.), but the stress relaxation property described above is impaired by the hard coat layer. In order to prevent this, the elastic modulus of the laminated sheet in the high temperature region is adjusted to 100 MPa or less (so as not to be too high) so as to maintain an appropriate elongation. Further, by making the total thickness of the laminated sheets 70 μm to 200 μm or less, it is possible to achieve both excellent self-supporting properties and flexibility, and by setting the thickness ratio of the hard coat layer to the film layer to 1 to 5%, While imparting surface hardness, it is possible to relieve the difference in wet heat dimensional change, and it is possible to remarkably suppress the occurrence of warpage occurring in the optical disc. Thus, since the difference in wet heat dimensional change of the laminated sheet can be alleviated without impairing the physical properties unique to each layer, it is preferable to adjust the total thickness of the laminated sheet and the thickness of each layer constituting the laminated sheet.
(A) Storage elastic modulus at 25 ° C. is 2000 MPa or more (B) Glass transition temperature as maximum of loss tangent of active energy ray-curable resin composition of film layer is 90 ° C. or lower (C) Storage elastic modulus at 100 ° C. Is 100 MPa or less (D) Elongation at break at 80 ° C. is 4% or more

Further, each layer constituting the laminated sheet of the first embodiment of the present invention is preferably made of a cured product of an active energy ray-curable resin composition having a nonvolatile component concentration of 95% or more. By using such a substantially solvent-free active energy ray-curable resin composition, it becomes possible to reduce the contamination to the adherend, and particularly effective in the field of advanced technology such as high precision parts and optical disks. Demonstrate.

The total thickness of the laminated sheet is preferably 70 to 200 μm or less, and more preferably 75 to 100 μm or less. The thickness ratio of the hard coat layer to the film layer is preferably 1 to 5%, more preferably 1 to 3%.

(Second form)
The laminated sheet of the second embodiment of the present invention has a structure in which a hard coat layer, a film layer, and an adhesive material layer are sequentially laminated, each layer is made of an active energy ray-curable resin composition, and has a total thickness of 70. If the thickness ratio of the adhesive layer to the film layer is 10 to 50% and the thickness ratio of the hard coat layer to the film layer is 1 to 5%, it is not particularly limited. When the total thickness of the laminated sheet is 70 μm to 200 μm or less, both excellent self-supporting property and flexibility can be achieved, and the thickness ratio of the adhesive layer to the film layer is 10 to 50%. The hardness of the sheet can be secured, the difference in wet heat dimensional change between the adherend and the laminated sheet can be reduced, and the thickness ratio of the hard coat layer to the film layer can be 1 to 5%. Accordingly, while imparting surface hardness, it is possible to relax the wet heat dimensional change difference. Thus, by adjusting the total thickness of the laminated sheet and the thickness of each layer constituting the laminated sheet, the wet heat dimensional change difference of the laminated sheet can be alleviated without impairing the physical properties unique to each layer.

The total thickness of the laminated sheet is required to be 70 to 200 μm or less, preferably 75 to 100 μm or less. Further, the thickness ratio of the pressure-sensitive adhesive layer to the film layer needs to be 10 to 50%, but it is preferably 15 to 30%, more preferably 20 to 25%. Further, the thickness ratio of the hard coat layer to the film layer needs to be 1 to 5%, and more preferably 1 to 3%.

(Film layer)
The film layer of the first form or the second form is composed of an active energy ray-curable resin composition containing a (meth) acrylate monomer, oligomer, polymer, or a mixture thereof, and active energy rays such as ultraviolet rays and electron beams. It is formed by curing. The active energy ray-curable resin composition is not particularly limited. For example, urethane (meth) acrylate type, epoxy (meth) acrylate type, polyester (meth) acrylate type, which is cured with active energy ray, Examples include polybutadiene (meth) acrylate-based and polyol poly (meth) acrylate-based monomer-type and oligomer-type active energy ray-curable resins as main components, and other photopolymerizable monomers and compositions containing photopolymerization initiators. It is done. Specifically, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, 2- (N, N-dimethylamino) ethyl acrylate, 2 -(N, N-diethylamino) ethyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, hydroxyethyl methacrylate, 2- (N, N-dimethylamino) ethyl methacrylate Monofunctional group type monomers such as 2- (N, N-diethylamino) ethyl methacrylate, pentaerythritol tetraacrylate, trimethylolpropane triacrylate, pentaerythritol tetramethacrylate, Multi-functional monomer such as dimethylolpropane trimethacrylate, adipic acid / 1,6 hexanediol oligomer diacrylate, phthalic anhydride / propylene oxide oligomer diacrylate, trimellitic acid diethylene glycol oligomer triacrylate, adipic acid / 1, Polyfunctional polyester acrylate oligomers such as 6-hexanediol oligomer dimethacrylate, phthalic anhydride / propylene oxide oligomer dimethacrylate, trimellitic acid diethylene glycol oligomer trimethacrylate, bisphenol A / epichlorohydrin oligomer acrylate, phenol novolac / epichlorohydrin oligomer Addition type of acrylate, cycloaliphatic epoxide and acrylic acid, bisphenol A / epichlorohydrin type oligomer methacrylate, phenol novolak / epichlorohydrin type oligomer methacrylate, polyfunctional epoxy acrylate such as addition type of cycloaliphatic epoxide and methacrylic acid, tolylene diisocyanate, hexamethylene diisocyanate, methylene diphenyl diisocyanate, Examples thereof include acrylic acid derivatives such as urethane (meth) acrylate relates derived from urethane oligomers obtained by reacting diisocyanates such as xylylene diisocyanate and isophorone diisocyanate with polyfunctional alcohols. These may be used alone or in combination of two or more.

Among active energy ray-curable resin compositions containing the above (meth) acrylate monomers, oligomers, polymers or mixtures thereof, urethane (meth) acrylate as a main agent, reactive diluents such as (meth) acrylate monomers, etc. When the laminated sheet is contained, in the first form, the storage elastic modulus at 25 ° C. is preferably 2000 MPa or more, and the storage elastic modulus at 100 ° C. is preferably adjusted to 100 MPa or less. The storage elastic modulus at 25 ° C. is preferably 1000 MPa or more, and the storage elastic modulus at 80 ° C. is preferably adjusted to 100 MPa or less. It is important that the storage elastic modulus is within this range. To make this range, the blending of the active energy ray-curable resin composition may be adjusted, and in particular, (1) urethane (meth) acrylate. 20 to 60 parts by mass, (2) 10 to 60 parts by mass of a monomer having an alkylene oxide group and at least two (meth) acryloyl groups, (3) having one (meth) acryloyl group and an aromatic ring structure in the molecule 10-50 parts by weight of monomer, (4) 0-20 parts by weight of monomer having one (meth) acryloyl group and alicyclic structure in the molecule, (5) 0-20 parts by weight of epoxy acrylate oligomer, (6) photopolymerization It is preferable to use a composition containing 0.1 to 10 parts by mass of an initiator. In addition, by adopting such a combination, it is also possible to obtain a laminated sheet made of a cured product of an active energy ray-curable resin composition having a nonvolatile component concentration of 95% or more, and to the adherend. Non-contamination can be reduced. Of course, the composition of the active energy ray-curable resin composition having an upper nonvolatile component concentration of 95% or more is not limited to the above.

The (1) urethane (meth) acrylate used in the film layer is suitable for imparting toughness and curability of the film, and is preferably contained in an amount of 20 to 60%. By adjusting to this range, the film is excellent in hardness and toughness, and the viscosity does not become too high. Examples of the urethane (meth) acrylate include urethane (meth) which can be synthesized by adding a hydroxyl group-containing (meth) acrylate to a compound obtained by urethane condensation of an aliphatic polyol or an aliphatic polyol glycidyl ether and an alicyclic diisocyanate. Mention may be made of acrylates.

Examples of the aliphatic polyol include alkyl polyols such as ethylene glycol, propylene glycol, tetramethylene glycol, and hexanediol. Examples of the aliphatic polyol glycidyl ether include polyethers such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Examples include glycol compounds such as polyols. These can be used individually by 1 type or in combination of 2 or more types. Among these, a tetramethylene glycol skeleton is preferable.

Examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and cyclohexanedimethanol. Mono (meth) acrylate, 2-hydroxyethyl (meth) acrylate and caprolactone adduct, 4-hydroxybutyl (meth) ブチル acrylate and caprolactone adduct, trimethylolpropane diacrylate, pentaerythritol triacrylate, dipentaerythritol pentaacrylate Etc. These can be used individually by 1 type or in combination of 2 or more types. Among these, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate are preferable.

Examples of the diisocyanate include aromatic diisocyanates such as tolylene diisocyanate and 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, bis (4-isocyanatocyclohexyl) methane, and 1,2-hydrogenated xylylene. Examples thereof include aliphatic diisocyanates such as range isocyanate, 1,4-hydrogenated xylylene diisocyanate, hydrogenated tetramethylxylylene diisocyanate, and norbornane diisocyanate. These can be used individually by 1 type or in combination of 2 or more types. Among these, alicyclic diisocyanate compounds are preferable, and isophorone diisocyanate is more preferable because of its excellent light transmittance, heat distortion resistance, and heat decomposition resistance.

Among the urethane (meth) acrylates obtained as described above, the urethane (meth) acrylate represented by the following [Chemical Formula 1] obtained by (meth) acrylating the terminal obtained by urethane condensation of isophorone diisocyanate and polytetraethylene glycol is more. Among them, urethane obtained by reacting 4-hydroxybutyl acrylate with the end of a structure having a weight average molecular weight of 600 to 10,000, more preferably 1000 to 4000 and having about 4 to 20 urethane bonds in the molecule is preferable. (Meth) acrylate is most preferred.

(In the formula, m represents an integer of 1 to 4, and n represents an integer of 1 to 10.)

As the monomer having the (2) alkylene oxide group and at least two (meth) acryloyl groups, a coating film can be easily obtained with high thickness accuracy when a composition is formed by a general film forming method such as die coating. In addition, the surface smoothness can be imparted, and for example, it is preferable that the coating film has a crosslinked structure with a bifunctional or higher (meth) acrylate functional group, and the main chain is a moderately rigid skeleton. And compounds represented by the following [Chemical Formula 4].

(However, R represents hydrogen or a methyl group, and n and m represent an integer of 1 to 4.)

Specific examples of the monomer (2) having an alkylene oxide group and at least two (meth) acryloyl groups include ethylene glycol-modified bisphenol A diacrylate, ethylene glycol-modified bisphenol F diacrylate, (poly) ethylene glycol diacrylate, (Poly) propylene glycol modified bisphenol A diacrylate, (poly) propylene glycol modified bisphenol F diacrylate, (poly) ethylene propylene glycol modified bisphenol A diacrylate, (poly) ethylene propylene glycol modified bisphenol F diacrylate, (poly) propylene Glycol diacrylate, glycerin glycidyl ether diacrylate, tripropylene glycol glycidyl ether diacrylate Chryrate, butanediol diacrylate, hexadiol diacrylate, EO modified neopentyl glycol diacrylate, PO modified neopentyl glycol diacrylate, EO modified trimethylolpropane triacrylate, PO modified trimethylolpropane triacrylate, EO modified trimethylolpropane tri Acrylate, PO modified trimethylolpropane triacrylate, EO modified pentaerythritol triacrylate, EO modified pentaerythritol tetraacrylate, PO modified pentaerythritol tetraacrylate, EO modified dipentaerythritol penta and hexaacrylate, PO modified dipentaerythritol penta and hexaacrylate , Etc. Among them, EO-modified bisphenol A diacrylate is preferable because it has a low viscosity and has a relatively high surface tension before curing, and can impart an appropriate hardness to the coating film after curing.

The above (3) monomer having one (meth) acryloyl group and aromatic ring structure in the molecule has a relatively low molecular weight, a low viscosity, and a large elongation of a single polymer. As a result, the viscosity of the composition It is preferable that the structure is easy to improve toughness by lowering, specifically, phenoxyethyl (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, nonylphenoxyethylene glycol (meth) acrylate, nonylphenoxypolyethylene glycol (meth) Acrylate, Nonylphenoxypropylene glycol (meth) acrylate, Nonylphenoxyethylene glycol (meth) acrylate, Nonylphenoxypolyethylene glycol (meth) acrylate, Nonylphenoxy polypropylene glycol (meth) acrylate , Paracumylphenoxyethylene glycol (meth) acrylate, paracumylphenoxypolyethylene glycol (meth) acrylate, paracumylphenoxypropylene glycol (meth) acrylate, paracumylphenoxypolypropylene glycol (meth) acrylate, 2-hydroxy-3-phenoxy -Propyl (meth) acrylate (= epichlorohydrin modified phenoxy (meth) acrylate).

The monomer having one (meth) acryloyl group and alicyclic structure in the molecule (4) is an alicyclic (meth) acrylate oligomer having a monofunctional (meth) acryloyl group, and the alicyclic structure is a cured product composition. The structure imparting hardness is good, specifically, norbornyl ring, adamantyl ring, dicyclopentane ring, tricyclodecane ring, tetracyclododecane ring, bornene ring, decahydronaphthalene ring, polyhydroanthracene ring, tricyclene, Examples include steroid skeletons such as cholesteric rings, bile acids, digitaloid rings, camphor rings, iso camphor rings, sesquiterpene rings, sandton rings, diterpene rings, triterpene rings, and steroid saponin rings. Because of its excellent surface hardness, With emissions skeleton (meth) acrylate. These alicyclic (meth) acrylate components can be used alone or in combination of two or more as desired. The (4) monomer having one (meth) acryloyl group and alicyclic structure in the molecule is blended as necessary, and if blended, the film-forming processability and heat distortion resistance of the composition. In addition, it is possible to obtain the effects of thermal decomposition resistance and cost improvement.

As said (5) epoxy (meth) acrylate, it is an epoxy (meth) acrylate oligomer having two or more (meth) acryloyl groups and has a high molecular weight and polarity, and the physical properties are easily improved by the reaction of acryloyl groups. Good structure, such as 1,4 butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, polypropylene Glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerin diglycidyl ether, trimethylolpropane triglycidyl ether, hydrogenated bisphenol Diglycidyl ether, 2,2-dibromoneopentyl glycol diglycidyl ether, trimethylol ethane triglycidyl ether, aliphatic polyol polyglycidyl ether, polyglycol diepoxide, castor oil polyglycidyl ether, cyclohexane dimethanol diglycidyl ether, resorcinol di Dibasic acids such as glycidyl ether, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, bisphenol A ethylene oxide addition diglycidyl ether, bisphenol A propylene oxide addition diglycidyl ether, phthalic acid and dihydrophthalic acid Diglycidyl ester compound obtained by the reaction of phenoxy and epihalohydrin; amino Epoxy compounds obtained by reaction of aromatic amines such as enol and bis (4-aminophenyl) methane with epihalohydrin; 1,1,1,3,3,3-hexafluoro-2,2- [4- (2 , 3-epoxypropoxy) phenyl] propane, phenol novolac type epoxy resin, and cresol novolac type epoxy resin, and the like (meth) acrylic acid adducts.

Furthermore, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, tetrabromobisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenoxy fluorenediglycidyl ether, bisphenoxyfluorene Epoxy resins such as ethanol diglycidyl ether, hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, cyclohexane dimethanol diglycidyl ether, tricyclodecane dimethanol diglycidyl ether, (meth) acrylic acid, (meta ) Epoxy (meth) acrylates obtained by reacting unsaturated monobasic acids such as acrylic acid dimer and caprolactone-modified (meth) acrylic acid And the like.

Among these epoxy (meth) acrylates, since the heat resistance of the resulting composition after curing can be improved, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol A ethylene oxide-added diglycidyl ether Bisphenol-type epoxy (meth) acrylate compounds, bisphenol A-type epoxy (meth) acrylate, bisphenol F-type epoxy, which are (meth) acrylic acid adducts of polyfunctional epoxy compounds such as bisphenol A propylene oxide-added diglycidyl ether (Meth) acrylate, bisphenol S type epoxy (meth) acrylate, tetrabromobisphenol A type epoxy (meth) acrylate, hydrogenated bisphenol A type epoxy (meth) acrylate, hydrogenated resin Bisphenol type epoxy (meth) acrylates such as phenol F type epoxy (meth) acrylate are suitable, and among them, bisphenol A type epoxy (meth) acrylate and bisphenol F type epoxy are excellent because of excellent balance between viscosity and heat resistance. (Meth) acrylate is more preferred, and bisphenol A glycidyl ether (meth) acrylate is particularly preferred.

Further, bisphenol type epoxy (meth) acrylate represented by the following [Chemical Formula 5] is particularly preferable.

(However, R1 and R2 represent hydrogen or a methyl group, and n represents an integer of 1 to 12.)

Further, the weight average molecular weight is preferably in the range of 400 to 4000 from the viewpoint of reducing the volume shrinkage due to the polymerization of the composition obtained. In the above general formula [5], the range of n = 1 to 12 is preferred. Is preferred.

When the weight average molecular weight of the bisphenol type epoxy (meth) acrylate exceeds 4000, the viscosity of the composition becomes extremely high, and the processability tends to be lowered. Therefore, in the present invention, when bisphenol type epoxy (meth) acrylate is used, it is more preferable to use one having a weight average molecular weight of 400 to 4000. These epoxy (meth) acrylates can be used alone or in combination of two or more as desired.

In addition, said (5) epoxy acrylate oligomer is mix | blended as needed, and if it mix | blends, the effect of a heat-resistant deformation property, heat-resistant decomposition property, secondary workability, and a cost improvement can be acquired.

Examples of the above (6) photopolymerization initiator include benzophenone, 4,4-bis (diethylamino) benzophenone, 2,4,6-trimethylbenzophene, methylorthobenzoylbenzoate, 4-phenylbenzophenone, and t-butylanthraquinone. 2-ethylanthraquinone, diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2-hydroxy-1- [4- [4- (2-hydroxy-2-methyl-propionyl) -Benzyl] phenyl] -2-methyl-propan-1-one, benzyldimethyl ketal, 1-hydroxycyclohexyl-phenyl ketone, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-methyl- [4 -(Methylthio) fu Nyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, diethylthioxanthone, isopropylthioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide Examples thereof include bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and methylbenzoylformate. These can be used alone or in combination of two or more. Among these, acetophenone derivatives whose decomposition products after generation of radicals do not become volatile components, specifically 2-hydroxy-1- [4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl] -2-Methyl-propan-1-one and the like, and benzophenone derivatives that do not generate decomposition products after radical generation are suitable in terms of transparency and durability. The amount of the photoinitiator is appropriately adjusted according to the curability and the like of the composition, and is typically 1 to 10 parts by weight with respect to 100 parts by weight of the active energy ray-curable resin composition of the present invention. is there.

(Hard coat layer)
The hard coat layer is made of an active energy ray-curable resin composition containing an acrylate monomer, oligomer, polymer, or a mixture thereof, and is formed by being cured with active energy rays such as ultraviolet rays and electron beams.

The active energy ray-curable hard coating agent is not particularly limited, and examples thereof include a silicone hard coating agent and a fluorine hard coating agent. Among these, in particular, (1) a polymer containing at least one (meth) acryloyloxy group in the side chain and a structure represented by the following [Chemical Formula 2] and / or at least one (meth) acryloyloxy group in the molecule; 5 to 20 parts by mass, preferably 5 to 10 parts by mass of a polymer having a fluoroalkylene oxide group (2) 30 to 60 parts by mass of a monomer containing at least three (meth) acryloyl groups in the molecule, (3) molecule It is preferable to use a composition containing 0 to 20 parts by mass of a monomer having one (meth) acryloyl group and a ring structure and (4) 0.1 to 10 parts by mass of a photopolymerization initiator. In addition, by adopting such a combination, it is also possible to obtain a laminated sheet made of a cured product of an active energy ray-curable resin composition having a nonvolatile component concentration of 95% or more, and to the adherend. Non-contamination can be reduced. Of course, the composition of the active energy ray-curable resin composition having an upper nonvolatile component concentration of 95% or more is not limited to the above.

(However, n represents an integer of 5 to 100.)

The above (4) photopolymerization initiator may be the same as the photopolymerization initiator described in the film layer.

The configuration of the laminated sheet of the first embodiment of the present invention is not particularly limited as long as it has a configuration in which a hard coat layer is laminated on at least one surface of the film layer, and is active on the opposite surface of the hard coat layer. An adhesive layer made of an energy ray curable resin composition can also be laminated.

(Adhesive layer)
The adhesive layer of the first form contains an active energy ray-curable resin composition containing a (meth) acrylate monomer, oligomer, polymer or a mixture thereof, and by active energy rays such as ultraviolet rays and electron beams. What is formed by curing is preferable, but in addition, any of acrylic, polyester, urethane, rubber, silicone, etc. may be used. Besides the active energy ray curable type, A thermosetting type can also be used, and these may be a mixed system, and is not necessarily limited.
Although it does not restrict | limit especially as an adhesive material layer of a 2nd form, It consists of an active energy ray curable resin composition containing a (meth) acrylate type monomer, an oligomer, a polymer, or a mixture thereof, an ultraviolet-ray, an electron beam It is formed by curing with active energy rays such as.
In the second embodiment, among the active energy ray-curable resin compositions containing these (meth) acrylate monomers, oligomers, polymers or mixtures thereof, the reaction of (meth) acrylate monomers and the like with urethane (meth) acrylate as the main ingredient It is preferable that the storage elastic modulus at 25 ° C. is 1000 MPa or more and the storage elastic modulus at 80 ° C. is 100 MPa or less when a laminated sheet is contained by including a reactive diluent. It is important to set the storage elastic modulus within this range. To make the storage elastic modulus within this range, the composition of the active energy ray-curable resin composition may be adjusted. Among them, (1) urethane (meth) acrylate 50 90 parts by mass, (2) 10-50 parts by mass of a compound having one (meth) acryloyl group and an aliphatic structure having 4 or more carbon atoms in the molecule, and (3) 1-10 parts by mass of a photopolymerization initiator. It is preferable to use a composition comprising the same.

The (1) urethane (meth) acrylate preferably has a structure in which both the coating suitability when uncured and the adhesive property of the cured product are compatible, and a hydroxyl group-containing acrylate is contained in one molecule in a structure in which a polyol and an isocyanate are condensed. The urethane (meth) acrylate obtained by combining 1 to 2 equivalents, for example, urethane (meth) acrylate represented by the following [Chemical Formula 3] can be mentioned.

(In the formula, R ₁ is an alkyl group having 4 or more carbon atoms, R ₂ is an aliphatic isocyanate compound residue, R ₃ is a polyol residue having a molecular weight of 300 or more, and R ₄ is hydrogen or an alkyl acrylate having 4 or more carbon atoms. Represents a group.)

In the formula, R ₂ represents an isocyanate residue. Specific examples include aromatic diisocyanates such as tolylene diisocyanate and 4,4-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, bis (4-isocyanate). And aliphatic diisocyanates such as natocyclohexyl) methane, 1,2-hydrogenated xylylene diisocyanate, 1,4-hydrogenated xylylene diisocyanate, hydrogenated tetramethyl xylylene diisocyanate, and norbornane diisocyanate. Of these, aliphatic isocyanate compounds are preferable, and isophorone diisocyanate and a polymer of isophorone diisocyanate are more preferable because they are excellent in light transmittance and heat decomposition resistance.

In the formula, R ₃ represents a polyol residue, and in order to impart flexibility and tackiness of the cured product, and because the compound viscosity before curing does not become too high, a structure with low polarity is preferable. A high molecular weight aliphatic polyol of 300 or more is preferable, and examples thereof include polyisobutylene polyol and polybutadiene polyol. R ₄ in the formula is hydrogen or a residual chain of a hydroxyl group-containing acrylate. The hydroxyl group-containing acrylate is not particularly limited, but an acrylate compound in which the alcohol residual chain is an alkyl alcohol having 4 to 20 carbon atoms is preferable.

Among the urethane (meth) acrylates, a urethane (meth) acrylate having a molecular weight of 10,000 to 200,000, more preferably a molecular weight of 15,000 to 100,000 is preferable. By setting it as this range, the crosslink density of the cured product does not increase, the tack and flexibility as an adhesive material are excellent, and the film forming property is excellent.

Examples of the compound (2) having one (meth) acryloyl group in the molecule and an aliphatic structure having 4 or more carbon atoms include butyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, octyl acrylate, isooctyl Examples thereof include acrylate compounds having a fatty structure such as acrylate, decyl acrylate, isodecyl acrylate, caprolactone acrylate, nonyl acrylate, and nonylphenoxyethylene glycol acrylate, or derivatives thereof.

The above (3) photopolymerization initiator may be the same as the photopolymerization initiator described in the film layer.

Components other than the above as the active energy ray curable resin composition constituting each layer include other photocurable oligomers / monomers, sensitizers, crosslinking agents, ultraviolet absorbers, polymerization inhibitors, fillers, heat Colorants such as plastic resins, dyes, and pigments can be added within a range that is effective and does not hinder physical properties such as curing, transparency, and heat resistance.

The production method of the laminated sheet of the present invention is not particularly limited, and in the first embodiment, for example, the activity sufficiently mixed and dispersed on the release film, belt, and roll for a process that is continuously driven at a constant speed. A film layer component made of an energy ray-curable resin composition is quantitatively supplied and shaped into a film shape by surface tension, heating, or pressure effect, cured by irradiation with active energy rays, and a film layer is formed. Subsequently to the above, the hard coat layer can be produced in the same manner in the order of film formation and lamination. In the case of further laminating other layers, for example, an adhesive layer, an adhesive layer is formed on the release film, and the film layer and the hard coat layer are laminated on the adhesive layer by the above method. It ’s fine.
In the second embodiment, for example, the adhesive layer component consisting of the active energy ray-curable resin composition sufficiently mixed and dispersed on the process release film, belt, and roll continuously driven at a constant speed is quantitatively supplied. Then, it is formed into a film shape by surface tension, heating, and pressure effect, irradiated with active energy rays and semi-cured to form an adhesive layer, and then the film layer and hard coat layer are similarly formed. Then, it can be manufactured by sequentially forming a film and laminating.

Gravure coating, roll coating, rod coating, knife coating, blade coating, screen coating, die coating, curtain flow coating, etc. can be used for quantitative supply of the active energy ray-curable resin composition constituting each layer of the present invention. it can. An appropriate method may be selected from these according to the thickness of the sheet when the composition of the present invention is formed into a sheet. For example, when a laminated sheet having a thickness of 70 to 200 μm is obtained, these thicknesses are in a thick region as the thickness of the sheet obtained by coating processing, and in consideration of thickness accuracy, processing effort, appearance, etc. A combination in which the composition is a solvent-free system in which the curing component is substantially 100% is preferable. Here, substantially 100% means that no solvent or volatile component is used in the composition formulation, or that the solvent residue or photoinitiator residue is negligible due to its low adverse effect on actual performance. And The influence on the coating processability due to the increase in the viscosity due to the solvent-free composition can be adjusted by material selection or heating in the composition.

Process release films include polyethylene film, biaxially stretched polypropylene film, poly-4-methylpentene-1 film, biaxially stretched polyethylene terephthalate film, biaxially stretched polyethylene naphthalate film, fluororesin film, etc. A film excellent in properties and smoothness can be used, preferably a biaxially stretched polyethylene terephthalate film excellent in optical smoothness, and more preferably excellent in optical smoothness that has been subjected to mold release treatment with a silicone coating. It is a biaxially stretched polyethylene terephthalate film. The degree of releasability is adjusted by the balance between the releasability after curing the composition, the wetting stability of the film form when coated, and the adhesion. The thickness of the release film is adjusted mainly by the balance of stability when coating the composition of the present invention, suppression of warpage due to curing shrinkage after curing, active energy ray permeability related to curing, and release film cost. Practically, it is 50 to 250 μm.

The process release belt is seamlessly joined to a sheet material with excellent smoothness and dimensional stability, such as stainless steel and surface-plated steel, and is applied to two or more rolls and used for continuous constant speed machining by driving the rolls. The surface can be further coated with a fluororesin or ceramic to increase the mold release. The process release roll is further released by coating the surface-plated steel with a fluororesin or ceramic. In forming a sheet, the composition can be shaped while only one side is in contact, and the other side can be processed in an atmospheric contact state, or can be processed by bringing the double-sided process release material into contact with various combinations. . However, when ultraviolet rays are applied as active energy rays, at least air or (transparent plastic) film is essential on one side due to the low transmittance, and energy rays are irradiated on the air or (transparent plastic) film side. Limited.

When a process release film is not used, a single laminated sheet can be obtained, so that it can be used for specific applications such as forming a film for optical function adjustment in a form such as winding it into a roll and cutting it into sheets. It will be. On the other hand, if a process release film is used, it can be obtained as a laminate sheet with a release film between it and a laminate sheet. It is also within the scope of the present invention that the process release film is used as a protective film or a process release film for a specific application in a form that is laminated as it is for a specific application.

The active energy ray for irradiating and curing the mixture of each compound raw material is not particularly limited and can be applied industrially, and includes ultraviolet rays, electron rays, γ rays, X rays, etc. When comprehensively judging thickness, energy, equipment cost, cost and quality of additives such as photoinitiators and sensitizers, ultraviolet rays are particularly easy to use. As the ultraviolet light source, various light emitting characteristics such as a low pressure mercury lamp, a high pressure mercury lamp, a xenon lamp and the like can be used without particular limitation, and can be appropriately adjusted according to the film thickness and the curing condition. The energy can be similarly adjusted, and the illuminance is approximately 0.1 to 5 J / cm ² . Furthermore, in order to improve irradiation efficiency, it is also possible to irradiate while making irradiation atmosphere into inert gas, such as nitrogen, or heating the shape | molded composition.

The optical recording medium of the present invention, for example, is provided with a light transmissive layer that also serves as a protective film on a disk substrate that has a concave and convex pattern such as pits and grooves formed on the surface and serves as a signal recording surface. The optical disk is configured to record and reproduce information by irradiating laser light from the above, and the laminated sheet of the present invention is used as the light transmission layer. In order to form a light transmission layer on a disk substrate, for example, an adhesive layer or the like is laminated on the laminated sheet of the present invention on the surface of a recording film (signal recording surface) formed on the disk substrate. After adhering the material layer surface, the laminated sheet may be irradiated with active energy rays and cured.

In this case, in order to prevent deterioration of the optical signal, the higher the light transmittance of the laminated sheet, the better. The light transmittance in the wavelength range of 380 to 800 nm is 88% or more, particularly 400 to 410 nm. The light transmittance in the wavelength range is preferably 90% or more. The wavelength of the optical signal applied to the optical recording medium of the present invention is not particularly limited, but may be laser light having a wavelength range of 380 to 800 nm generally used for reading and writing of an optical disc, A blue-violet laser beam of around 400 nm capable of increasing the recording capacity is extremely preferable because the transmittance in this wavelength region is 90% or more as described above.

(Synthesis of hard coat layer components)
<Production Example 1>
[(1) Synthesis of Polymer A Containing Silicone and Methacryloyl Group in Side Chain]
In a reactor equipped with a stirrer, a thermometer, a condenser, and a nitrogen gas inlet, 500 parts by weight of toluene, 300 parts by weight of ethyl acrylate, and 300 parts by weight of 2-hydroxyethyl acrylate were added up to 80 ° C. in a nitrogen atmosphere. The temperature was raised. A mixture of 180 parts by weight of a silicone oil containing a methacryloyl group at one end (X-22-174DX: manufactured by Shin-Etsu Silicone) and 10 parts of azobisisobutyronitrile as a polymerization catalyst was added dropwise thereto over 30 minutes. After the polymerization treatment for 2 hours while preventing overheating with the heating medium, the polymerization treatment was carried out for 2 hours while dropping a mixture of 220 parts by weight of isocyanate acrylate (Karenz MOI: Showa Denko) and 1 part by weight of dibutyltin dilaurate as a polymerization catalyst. An acrylic copolymer having a weight average molecular weight of 20,000 (polystyrene conversion by gel permeation chromatography) and a methacryloyl group in the side chain was obtained.

<Production Example 2>
[(2) Synthesis of fluoroalkylene oxide side chain precursor B-1]
Fluoroalkylene oxide having one terminal isocyanate group by reacting 300 parts by weight of a fluoroethoxy-fluoromethoxyether compound having a terminal alcohol group (molecular weight 1500) and 45 parts by weight of isophorone diisocyanate in toluene while raising the temperature to 80 ° C. A compound was obtained (B-1).

<Production Example 3>
[(2) ′ Synthesis of Polymer B Containing Fluoroalkylene Oxide and Methacryloyl Group in Side Chain]
In the same manner as in Production Example 1, 380 parts by weight of ethyl acrylate and 200 parts by weight of 2-hydroxyethyl acrylate were subjected to a polymerization reaction in toluene at 80 ° C. for 2 hours using 5 parts of azobisisobutyronitrile as a polymerization catalyst. 250 parts by weight of isocyanate acrylate (Karenz MOI: Showa Denko), 170 g of the fluoroalkylene oxide compound (B-1) obtained above and 1 part by weight of dibutyltin dilaurate as a polymerization catalyst were dropped for 2 hours while polymerizing, An acrylic copolymer having a weight-average molecular weight of 20,000 (in terms of polystyrene by gel permeation chromatography) having a fluoroalkylene oxide structure and a methacryloyl group in the side chain was obtained.

(Preparation of curable resin composition 1 for hard coat layer)
After mixing to 8% by mass of the acrylic copolymer obtained in Production Example 1, 50% by mass of pentaerythritol tetraacrylate, 20% by mass of ethoxyphenyl acrylate, and 20% by mass of tetrahydrofurfuryl acrylate, and then concentrated under reduced pressure. After removing the solvent so that the volatile component was 5% or less, 2% by mass of bisacylphosphine oxide was mixed and dissolved to obtain a curable resin composition 1 for a hard coat layer. With the temperature maintained at 25 ° C., an H2 type rotor was attached to a Toki Sangyo B-type viscometer (TVB-10), and the viscosity of the composition was measured at a rotational speed of 100 rpm. The result was 250 mPa · s. It was.

(Preparation of curable resin composition 2 for hard coat layer)
Pentaerythritol tetraacrylate 50 mass%, ethoxyphenyl acrylate 20 mass%, tetrahydrofurfuryl acrylate 10 mass%, silicone-containing copolymer obtained in Production Example 1 8 mass%, fluoroalkylene oxide-containing copolymer obtained in Production Example 3 8% by mass of the coalescence and 4% by mass of bisacylphosphine oxide were mixed and dissolved to obtain a curable resin composition 2 for a hard coat layer.

(Preparation of curable resin composition 1 for film layer)
As the urethane (meth) acrylate relate, the urethane (meth) acrylate relate shown in the following [Chemical Formula 1] (urethane obtained by adding 4-hydroxybutyl acrylate to the end of urethane condensation of isophorone diisocyanate and tetramethylene glycol) ) Acrylate relate (weight average molecule; 1000 to 4000) 38% by mass, ethylene oxide (4 mol) modified bisphenol A diacrylate 30% by mass, 2-hydroxy-3-phenoxypropyl acrylate 20% by mass, isobornyl acrylate 10% by mass , And 2-hydroxy-1- {4- [4- (hydroxy-2-methyl-propionyl) benzyl] phenyl} -2-methyl-propan-1-one are mixed and dissolved, and the film layer is cured. Resin composition 1 is obtained .

(Preparation of curable resin composition 2 for film layer)
48% by mass of urethane (meth) acrylate similar to the curable resin composition 1 of the film layer, 20% by mass of bilphenol A epoxy acrylate, 30% by mass of tricyclodecane diacrylate, 2-hydroxy-1- {4- [ 4- (Hydroxy-2-methyl-propionyl) benzyl] phenyl} -2-methyl-propan-1-one (2% by mass) was mixed and dissolved to obtain a curable resin composition 2 having a film layer.

(Preparation of curable resin composition 3 for film layer)
48% by mass of urethane (meth) acrylate, 50% by mass of tricyclodecane diacrylate, and 2-hydroxy-1- {4- [4- (hydroxy-2-methyl-) as in the curable resin composition 1 of the film layer. 2 mass% of propionyl) benzyl] phenyl} -2-methyl-propan-1-one was mixed and dissolved to obtain a curable resin composition 3 for the film layer.

(Preparation of curable resin composition 4 for film layer)
48% by mass of urethane (meth) acrylate, 20% by mass of bilphenol A epoxy acrylate, 30% by mass of nonylphenoxyethylene glycol acrylate, 2-hydroxy-1- {4- [ 4- (Hydroxy-2-methyl-propionyl) benzyl] phenyl} -2-methyl-propan-1-one (2% by mass) was mixed and dissolved to obtain a curable resin composition 4 for a film layer.

(Preparation of curable resin composition 5 for film layer)
As urethane (meth) acrylate, urethane (meth) acrylate shown in the following [Chemical Formula 1] (urethane (meth) acrylate obtained by adding 4-hydroxybutyl acrylate to the end of urethane condensation of isophorone diisocyanate and tetramethylene glycol) (Weight average molecule; 1000 to 4000) 38% by mass, ethylene oxide (4 mol) modified bisphenol A diacrylate 30% by mass, 2-hydroxy-3-phenoxypropyl acrylate 20% by mass, isobornyl acrylate 10% by mass, and 2 -Hydroxy-1- {4- [4- (hydroxy-2-methyl-propionyl) benzyl] phenyl} -2-methyl-propan-1-one 2% by mass is mixed and dissolved to form a curable resin composition for the film layer Product 5 was obtained.

(Preparation of curable resin composition for adhesive layer)
As urethane (meth) acrylate, 4-hydroxybutyl acrylate was added to the end of urethane condensation of urethane (meth) acrylate (bis (4-isocyanatocyclohexyl) methane and polyisobutylene diol shown in [Chemical Formula 3] below. 70 mass% of the obtained urethane (meth) acrylate (weight average molecule; 15000)), 20 mass% of isodecyl acrylate, 6 mass% of isobornyl acrylate, and 4 mass% of trimethylbenzophenone are mixed and dissolved, and the curability of the adhesive material layer. A resin composition was obtained.

(Wherein R ₁ is a tetraalkyl chain, R ₂ is a residual chain of bis (4-isocyanatocyclohexyl) methane), R ₃ is a residual chain of polyisobutylene polyol, R ₄ is a residual chain of hydrogen or 4-hydroxybutyl acrylate. Represent. )

<Example 1>
On a smooth polyethylene terephthalate film having a releasability of 100 μm, a film layer of curable resin composition 1 was formed with a die coater at a thickness of 78 μm, and irradiation intensity was 200 mW / cm ² with a high-pressure mercury lamp. After irradiating active energy rays so that the integrated light quantity is 600 mJ, the curable resin composition 1 of the hard coat layer is applied onto the film layer with a gravure coater to a coating thickness of 2 μm, and a metal halide lamp A hard coat layer was formed by irradiating an active energy ray at an irradiation intensity of 200 mW / cm ² and an integrated irradiation amount of 400 mJ / cm ² to obtain a laminated sheet 1.

<Example 2>
On a smooth polyethylene terephthalate film having a releasability of 100 μm, a curable resin composition 1 of a film layer / a curable resin composition 1 of a hard coat layer is formed by a two-layer die at a thickness of 79 μm / 1 μm. The laminated sheet 2 was obtained by coating the hard coat layer on top and irradiating the active energy rays with a high-pressure mercury lamp so that the accumulated light amount was 800 mJ / cm ² .

<Example 3>
A laminated sheet 3 was obtained in the same manner as in Example 2 except that the thickness of the film layer / hard coat layer was 76 μm / 4 μm, respectively.

<Example 4>
A laminated sheet 4 was obtained in the same manner as in Example 1 except that the curable resin composition 2 of the film layer was used.

<Comparative Example 1>
On a smooth polyethylene terephthalate film having a releasability of 100 μm, a curable resin composition 1 of a film layer was formed with a die coater at a thickness of 80 μm, and an irradiation intensity of 200 mW / cm ² with a high-pressure mercury lamp, After irradiating the active energy ray so that the integrated light quantity is 600 mJ, the hard coat layer curable resin composition 1 is coated on the film layer with a die coater by 10 μm, and the active energy ray is irradiated with a metal halide lamp with an irradiation intensity of 200 mW. / cm ^2, was irradiated such that the integrated irradiation dose 400 mJ / cm ² to form a hard coat layer to obtain a laminated sheet 5.

<Comparative example 2>
A laminated sheet 6 was obtained in the same manner as in Example 1 except that the film layer curable resin composition 3 was used.

<Comparative Example 3>
A laminated sheet 7 was obtained in the same manner as in Example 1 except that the thickness of the film layer / hard coat layer was 30 μm / 5 μm.

<Comparative Example 4>
A laminated sheet 8 was obtained in the same manner as in Example 1 except that the film layer curable resin composition 4 was used.

<Comparative Example 5>
On a smooth polyethylene terephthalate film having a releasability of 100 μm, a curable resin composition 1 of a film layer was formed with a die coater at a thickness of 80 μm, and an irradiation intensity of 200 mW / cm ² with a high-pressure mercury lamp, The laminated sheet 9 was obtained by irradiating active energy rays so that the integrated light amount was 600 mJ.

<Example 5>
A smooth polyethylene terephthalate film with a thickness of 75 μm having releasability is coated with a curable resin composition of the above adhesive layer at a thickness of 20 μm with a die coater and irradiated with active energy rays with a high-pressure mercury lamp. The adhesive layer was semi-cured by irradiation with an intensity of 100 mW / cm ² and an integrated light amount of 600 mJ. Further, a curable resin composition 5 of a film layer is formed with a thickness of 77 μm with a die coater, and an active energy ray is irradiated with an irradiation intensity of 200 mW / cm ² and an integrated light amount of 600 mJ with a high-pressure mercury lamp. After that, the hard coat layer curable resin composition 2 was coated on the film layer with a gravure coater to a thickness of 2 μm, and an active energy ray was irradiated with a metal halide lamp with an irradiation intensity of 200 mW / cm ² and an integrated irradiation amount of 400 mJ. Irradiation was performed so as to be / cm ² to obtain a laminated sheet 10.

<Example 6>
After a 20 μm adhesive layer was provided in the same manner as in Example 5, the film layer curable resin composition 5 / hard coat layer curable resin was formed by a two-layer die on the semi-cured adhesive layer. The composition 2 was applied so that the hard coat layer had a thickness of 77 μm / 3 μm, and was irradiated with an active energy ray with a high-pressure mercury lamp so as to obtain an integrated light amount of 600 mJ, whereby a laminated sheet 11 was obtained.

<Comparative Example 6>
The curable resin composition of the pressure-sensitive adhesive layer is applied to a smooth polyethylene terephthalate film having releasability at a thickness of 20 μm with a die coater, and a two-layer die is formed on the uncured pressure-sensitive adhesive layer. Film layer curable resin composition 5 / hard coat layer curable resin composition 2 was applied to a thickness of 75 μm / 5 μm, and activated with a high-pressure mercury lamp to achieve an integrated light quantity of 1000 mJ / cm ^2. The laminated sheet 12 was obtained by irradiation with energy rays.

<Comparative Example 7>
A laminated sheet 13 was obtained in the same manner as in Example 6 except that the thickness ratio of the pressure-sensitive adhesive layer / film layer / hard coat layer was 20 μm / 30 μm / 5 μm.

<Comparative Example 8>
A laminated sheet 14 was obtained in the same manner as in Example 6 except that the hard coat layer was not provided.

<Film physical property evaluation>
(Dynamic viscoelasticity)
The obtained laminated sheets 1 to 14 were heated from −50 ° C. to 150 ° C. at a rate of 10 Hz and 3 ° C./minute using “DVA-200” manufactured by IT Measurement Control Co., Ltd. Measured the glass transition temperature at the maximum value of storage elastic modulus and loss tangent (tan δ) at 25 ° C. and 100 ° C., and for laminated sheets 10 to 14 at 25 ° C. and 80 ° C. The results are shown in Table 1 or 2. The glass transition temperature in Table 1 is a value of the curable resin composition of each film layer constituting the laminated sheets 1 to 9.

(Tensile elongation at break)
The process release films of the obtained laminated sheets 1 to 9 were peeled to form strips having a width of 10 mm, and heated in a chamber heated to 80 ° C. using a film tensile tester (205X manufactured by Intesco Corporation). Then, a tensile test was performed at a pulling speed of 5 mm / min, and the elongation (%) at break was measured. The results are shown in Table 1.

<Film processability evaluation>
The process substrate of the obtained laminated sheet was peeled off, and 10 sheets were cut with a Thomson blade, and the following evaluations were made according to the situation at the time of cutting.
○: All were cut cleanly and without problems.
X: Some cracks were observed on the cut surface.

<Production and evaluation of optical disk having cured product layer>
An inorganic layer was laminated in the order of an Ag reflection film, a ZnS—SiO ₂ dielectric layer, an Sb / Te phase change recording film, and a ZnS—SiO ₂ dielectric layer on a 1.1 mm thick polycarbonate molded into a disk shape. For the above laminated sheets 1-9, a 100 μm stroke release film was peeled off and an acrylic adhesive sheet was laminated to a total thickness of 100 μm, and then laminated to the inorganic layer laminated side of the substrate. 1 to 9 were prepared, and for the laminated sheets 10 to 14, an acrylic pressure-sensitive adhesive sheet was laminated on the inorganic layer laminated side of the substrate so that the 75 μm stroke release film was peeled off and the total thickness was 100 μm. Samples 1 to 9 were prepared and evaluated as follows.

<Surface performance evaluation>
(Pencil hardness)
About the obtained disk sample, the pencil hardness of the laminated sheet side surface was measured, and HB or more was determined to be ◯, and B or less was determined to be ×.

(Abrasion resistance)
A # 0000 steel wool was reciprocated 10 times at a load of 250 g in the obtained disk sample, and it was determined that the scratched one was ◯ and the scratched one was ×.

<Durability evaluation>
(Corrosion resistance test)
The disk sample was allowed to stand for 200 hours in a constant temperature and humidity chamber at a temperature of 80 ° C. and a humidity of 85% RH, and then the appearance of the disk sample was visually determined to make the following determinations.
○: Corrosion of the deposited layer, peeling of the protective film, cracking, etc. were not observed.
X: Corrosion of the deposited layer or peeling or cracking of the protective film was observed.

(War endurance test)
The following judgment was performed about the curvature after putting the obtained optical disk on 80 degreeC85% relative humidity for 500 hours.
○: The difference between the initial warp angle and the warp angle after 500 hours at 80 ° C. and 85% relative humidity is less than 0.4 °
X: The difference between the initial warp angle and the warp angle after 500 hours at 80 ° C and 85% relative humidity is 0.4 ° or more.

(Heat shock test)
The following determination was made regarding the amount of warpage change when the obtained optical disk was suddenly changed from 25 ° C. to 55 ° C.
○: The difference between the warp angle in the 25 ° C temperature environment and the warp angle when the environment is suddenly changed to 55 ° C is less than 0.6 ° ×: When the environment is suddenly changed to the warp angle under the 25 ° C temperature environment and 55 ° C Difference of warp angle is 0.6 ° or more

(Comprehensive evaluation)
For all tests of film processability, surface performance and durability evaluation, a case where an evaluation of “◯” was obtained was regarded as a comprehensive evaluation, and a case where there was an evaluation of “×” was regarded as an overall evaluation.

Claims

A laminated sheet having a structure in which a hard coat layer is laminated on at least one surface of a film layer, each layer comprising an active energy ray-curable resin composition, and the following properties (A) to (D) A laminated sheet comprising:
(A) Storage elastic modulus at 25 ° C. is 2000 MPa or more (B) Glass transition temperature as maximum of loss tangent of active energy ray-curable resin composition of film layer is 90 ° C. or lower (C) Storage elastic modulus at 100 ° C. Is 100 MPa or less (D) Elongation at break at 80 ° C. is 4% or more
2. The laminated sheet according to claim 1, wherein the total thickness of the laminated sheets is 70 to 200 μm or less, and the thickness ratio of the hard coat layer to the film layer is 1 to 5%.
A laminated sheet having a configuration in which a hard coat layer, a film layer, and an adhesive layer are sequentially laminated, each layer comprising an active energy ray-curable resin composition, and the total thickness of the laminated sheet is 70 to 200 μm or less. And a thickness ratio of the pressure-sensitive adhesive layer to the film layer is 10 to 50%, and a thickness ratio of the hard coat layer to the film layer is 1 to 5%.
The laminated sheet according to claim 3, wherein the storage elastic modulus at 25 ° C is 1000 MPa or more and the storage elastic modulus at 80 ° C is 100 MPa or less.
The laminated sheet according to any one of claims 1 to 4, wherein the film layer comprises a composition containing the compounds shown in the following (1) to (6).
(1) 20 to 60 parts by mass of a urethane (meth) acrylate oligomer represented by the following [Chemical Formula 1]

(In the formula, m represents an integer of 1 to 4, and n represents an integer of 1 to 10.)
(2) 10 to 60 parts by mass of a monomer having an alkylene oxide group and at least two (meth) acryloyl groups (3) 10 to 50 parts by mass of a monomer having one (meth) acryloyl group and an aromatic ring structure in the molecule ( 4) Monomer having 1 (meth) acryloyl group and alicyclic structure in the molecule 0 to 20 parts by mass (5) Epoxy (meth) acrylate 0 to 20 parts by mass (6) Photopolymerization initiator 0.1 to 10 parts by mass Part
The laminated sheet according to any one of claims 1 to 5, wherein the hard coat layer comprises a composition containing the following compounds (1) to (4).
(1) A polymer containing at least one (meth) acryloyloxy group in the side chain and a structure represented by the following [Chemical Formula 2] and / or at least one (meth) acryloyloxy group in the molecule, and a fluoroalkylene oxide group 5 to 20 parts by mass of a polymer having

(However, n represents an integer of 5 to 100.)
(2) 30 to 60 parts by mass of a monomer containing at least three (meth) acryloyl groups in the molecule (3) 0 to 20 parts by mass of a monomer having one (meth) acryloyl group and a ring structure in the molecule (4) Photopolymerization initiator 0.1 to 10 parts by mass
The laminated sheet according to any one of claims 3 to 6, wherein the pressure-sensitive adhesive layer is composed of a composition containing the following compounds (1) to (3).
(1) Urethane (meth) acrylate having a skeleton of the following [Chemical Formula 3], an average number of functional groups per molecule of 1 to 2, and a molecular weight of 10,000 or more, 50 to 90 parts by mass

(In the formula, R 1 is an alkyl group having 4 or more carbon atoms, R 2 is an aliphatic isocyanate compound residue, R 3 is a polyol residue having a molecular weight of 300 or more, and R 4 is hydrogen or an alkyl acrylate having 4 or more carbon atoms. Represents a group.)
(2) 10 to 50 parts by mass of a compound having one (meth) acryloyl group and an aliphatic structure having 4 or more carbon atoms in the molecule (3) 1 to 10 parts by mass of a photopolymerization initiator
8. The laminated sheet according to claim 5, wherein the photopolymerization initiator is an α-hydroxyacetophenone derivative or a benzophenone derivative having a molecular weight of 300 or more.
An optical disk protective film comprising the laminated sheet according to any one of claims 1 to 8.
An optical recording medium obtained by laminating at least one layer of the laminated sheet according to any one of claims 1 to 8.