JP2006096811A - Hard-coated film and information recording carrier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hard-coated film having excellent optical properties to give uniform transmission light and reflection light, an information recording carrier produced by using the film and enabling the recording and reproduction by optical means or magnetic means, a hard-coated film having excellent storage stability to effectively prevent the scratch mark on the plane of incidence and an information recording carrier produced by using the film. <P>SOLUTION: The hard-coated film is produced by applying a hard coat layer composed of one or more layers on a resin material containing an alkaline earth metal carbonate crystal having an aspect ratio of ≥1.5. The information recording carrier capable of reproducing an information signal by an optical means has at least a substrate, a recording layer recording an information signal and a light-transmission layer composed of a resin material containing an alkaline earth metal carbonate crystal having an aspect ratio of ≥1.5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a hard coat film having excellent optical characteristics and an information record carrier capable of recording / reproducing by optical means or magnetic means, and more particularly to an information record carrier capable of reproducing by optical means.

  Conventionally, a record carrier called CD-R is widely known as a write-once type optical information record carrier capable of recording information only once with a laser beam. The CD-R has an advantage that it can be reproduced using a commercially available CD player, and recently, the demand for the CD-R has increased with the spread of personal computers. Further, as an information recording carrier capable of recording a larger capacity than a CD-R, a write-once digital versatile disc (DVD-R) for supporting digital high-definition recording has been put into practical use.

  As these recordable optical information recording carriers, for example, on a disc-like support, a light reflecting layer made of Au or the like, a recording layer made of an organic compound, and a light-transmitting layer (recording layer) for protecting the recording layer And a cover layer are also sequentially stacked. Recording and reproduction are performed by irradiating a laser beam from the light-transmitting layer side. be able to. Information is recorded on the write-once type optical information record carrier when the laser light irradiation portion of the recording layer absorbs the light and locally generates heat (for example, generation of pits). On the other hand, information reproduction is usually performed by irradiating a write-once optical information recording carrier with a laser beam having the same wavelength as the recording laser beam, so that the recording layer is heated and deformed (recorded portion) and not deformed ( This is done by detecting the difference in reflectance from the unrecorded portion.

  Recently, networks such as the Internet and high-definition TV are rapidly spreading. Also, HDTV (High Definition Television) has started to be broadcast. Under such circumstances, there is a need for a large-capacity optical information record carrier capable of recording image information inexpensively and easily. The DVD-R plays a role as a large-capacity record carrier at present, but the demand for larger capacity and higher density is increasing, and the development of a record carrier that can meet these demands is also necessary. It is. For this reason, as an optical information record carrier, development of a larger capacity record carrier capable of performing high-density recording with light of a short wavelength is being promoted. In particular, write-once type optical information record carriers capable of recording information only once are frequently used for long-term storage or backup of large-capacity information, and thus there is a strong demand for development.

  Usually, the density of an optical information record carrier is increased by reducing the beam spot by shortening the wavelength of the recording and reproducing laser and increasing the NA (Numerical Aperture) of the objective lens used for the pickup. be able to. Recently, development has rapidly progressed from red semiconductor lasers with wavelengths of 680 nm, 650 nm, and 635 nm to blue-violet semiconductor lasers with wavelengths of 400 nm to 500 nm (hereinafter referred to as blue-violet lasers) that enable ultra-high density recording. Therefore, development of optical information record carriers corresponding to this is also underway. In particular, since the release of the blue-violet laser, development of an optical recording system using the blue-violet laser and a high NA pickup has been studied. A rewritable optical information recording carrier and optical recording system having a phase-change recording layer are: It has already been announced as a DVR system (for example, see Non-Patent Document 1). Thereby, a certain result was obtained with respect to the problem of high density in the rewritable optical information record carrier.

The optical information recording carrier used in the optical recording system using the blue-violet laser and the high NA pickup as described above is a laser for focusing the high-NA objective lens when the recording layer is irradiated with the blue-violet laser light. It is preferable to thin from the surface of the information record carrier on which light is incident to the recording layer (that is, the light transmitting layer). Therefore, according to the standard, the thickness of the light transmitting layer is set to 100 μm. Since such an optical information record carrier uses a high NA pickup as described above, the distance between the pickup and the translucent layer is small, and the pickup and the translucent layer are in contact with each other due to surface blurring of the optical information record carrier. As a result, the light-transmitting layer is likely to be damaged.
In order to solve this problem, a method for preventing scratches on the light-transmitting layer by providing a scratch-preventing layer or a hard coat layer on the light-transmitting layer using a spin coating method or a vacuum deposition method has already been proposed (for example, patents). Reference 1 and 2). However, since these scratch-preventing layers and hard coat layers are provided in a single-wafer type on the light-transmitting layer, there is a problem that productivity is low. Further, when these scratch-preventing layers and hard coat layers are provided by the spin coating method, the layer thickness of the outer peripheral portion tends to be thicker due to centrifugal force, and the thickness accuracy is not sufficient.

  On the other hand, there is a method of forming a light-transmitting layer by using a transparent and thin film such as a polycarbonate or a cellulose acylate film and adhering to a recording layer using an adhesive or an adhesive (for example, Patent Documents 3 and 4). reference). The thickness of the light-transmitting layer is usually about 100 μm including the adhesive layer or pressure-sensitive adhesive layer formed by curing the adhesive or pressure-sensitive adhesive, but is optimized by the wavelength of the irradiated laser and the NA. Although the information record carrier configured by such a method is excellent in productivity, polycarbonate without optical anisotropy is expensive and is inappropriate as an optical recording material to be used in large quantities. Moreover, when the cellulose acylate film marketed is used, it turned out that the reading characteristic after a long-term storage is inadequate.

  On the other hand, Patent Documents 5 and 6 show a film in which optical anisotropy does not occur even when stretched by adding silica fine particles or acicular calcium carbonate to a polymethyl methacrylate film or a cyclic olefin film. . These films are mainly intended for application to liquid crystal display devices, and the possibility of application to optical disks has been shown. However, when the film described in the specification is used for an optical disc and a signal is read and written by a 405 nm laser, the signal is disturbed by the particles themselves or voids generated before and after the particles, and the application to a high-density optical recording medium. I knew that I couldn't.

Japanese Patent No. 311467 JP 2000-67468 A JP 2002-170280 A JP 2002-197723 A International Patent Publication No. 01-25364 JP 2001-20891 A Optical Memory International Symposium (ISOM2000) Proceedings, p.210-211

The present invention provides a hard coat film excellent in optical properties such as isotropic (low birefringence) without unevenness of transmitted light and reflected light, and information recording that can be recorded / reproduced by optical means or magnetic means. An object of the present invention is to provide an information recording carrier having excellent recording and reading characteristics on the carrier.
Furthermore, another object of the present invention is to provide a hard coat film and an information recording carrier that are effectively prevented from generating scratches on the light incident surface and are excellent in storage stability.

As a result of intensive studies by the present inventors, it has been found that the above problem can be solved by the following configuration.
(1) A hard coat film obtained by applying at least one hard coat layer on a resin material containing an alkaline earth metal carbonate crystal having an aspect ratio of 1.5 or more.
(2) The hard coat film as described in (1) above, wherein the carbonate crystal contained in the resin material has a cross-sectional equivalent circle diameter of 1 to 50 nm.
(3) The hard coat film as described in (1) or (2) above, wherein the resin material is polyester or polycarbonate.
(4) The hard coat layer comprises at least a polyfunctional acrylic acid monomer and a powdery inorganic filler, and contains 5 to 60% by weight of the inorganic filler. The hard coat film according to any one of the above.

(5) The hard coat film according to any one of the above (1) to (4), wherein an adhesive is applied to at least one surface to form a film with an adhesive.

(6) An information recording carrier capable of recording and / or reproducing information signals by optical means, a support, a recording layer capable of recording an information signal formed on the support, and the recording layer And a light-transmitting layer that transmits light formed thereon, and the light-transmitting layer is made of a resin material containing an alkaline earth metal carbonate crystal having an aspect ratio of 1.5 or more. An information record carrier.
(7) The information recording carrier as described in (6) above, wherein the resin material containing carbonate crystals is polyester or polycarbonate.
(8) The above light-transmitting layer, wherein at least one hard coat layer is applied to a resin material surface containing an alkaline earth metal carbonate crystal having an aspect ratio of 1.5 or more ( The information record carrier according to 6) or (7).
(9) The above (7) or (8), wherein the hard coat layer comprises at least a polyfunctional acrylic acid monomer and a powdery inorganic filler, and contains 5 to 60% by weight of the inorganic filler. The information record carrier described.
(10) A film with an adhesive obtained by applying an adhesive to the hard coat film is obtained by bonding to a substrate provided with a recording layer capable of recording an information signal on a support. The information recording carrier according to any one of (7) to (9) above.

  According to the present invention, it is possible to provide a hard coat film with less unevenness of transmitted light and reflected light, effectively preventing the occurrence of scratches on the light incident surface, small optical anisotropy and excellent storage stability. . As a result, an information record carrier excellent in recording and reading characteristics can be provided in an information record carrier that can be recorded and reproduced by optical means. The information record carrier of the present invention is particularly effective for an optical information recording system using a blue-violet laser and a high NA pickup.

Hereinafter, the information record carrier of the present invention will be described in more detail. In the present specification, the description “(numerical value 1) to (numerical value 2)” means “(numerical value 1) or more and (numerical value 2) or less”.
First, in order to facilitate the description of the hard coat film of the present invention and the information record carrier of the present invention in which the hard coat film is incorporated in the constituent layers, a typical configuration example of the information record carrier of the present invention is shown in FIG. Each constituent layer including the hard coat layer and the substrate described below and the substrate are shown in FIG. 1 by direct member names instead of member numbers.
Here, when there is no pressure-sensitive adhesive layer or barrier layer, the transmission layer is the same as the hard coat film. Moreover, when there is no barrier layer, a permeation | transmission layer is synonymous with a film with an adhesive. Furthermore, when using a hard coat film and a film with an adhesive as a light-transmitting layer of an information recording carrier, these may be called a light-transmitting film.

<1. Resin material>
First, the resin material used in the present invention will be described. The resin material used in the present invention is a low birefringence optical resin material. Specifically, the birefringence is reduced so that the birefringence is not substantially exhibited, or the birefringence is low but the degree is low. It is a resin material. Details of such an optical resin material used in the present invention will be specifically described below.

<1-1. Optical Anisotropy Control Method for Resin Materials>
In general, in an optical resin material, birefringence is generated according to the actual processing method, as is widely known including its cause. That is, in almost all polymer resins that are usually used as optical resin materials, the monomer that forms the polymer has optical anisotropy due to the wavefront dependence of the refractive index. For this reason, an optical anisotropy is also exhibited in an optical resin material made of a polymer composed of this monomer and arranged or oriented in a certain direction, resulting in birefringence.

  Usually, a polymer resin in a state produced by a polymerization reaction does not exhibit birefringence because the polymer chain is randomly entangled and the above-mentioned orientation does not occur in the polymer chain. . That is, in this state, since the optical anisotropy of each monomer cancels each other, birefringence is not expressed as a polymer resin. However, when such a polymer resin undergoes a molding process such as injection molding or extrusion molding, the resulting polymer resin is oriented as a result of orientation of random polymer chains due to external forces applied at that time. It exhibits birefringence.

  In almost all polymer resins used as optical resin materials, each bond unit has optical anisotropy with respect to the refractive index. That is, the refractive index npr related to the polarization component in the direction parallel to the alignment direction is different from the refractive index nvt related to the polarization component in the direction perpendicular to the alignment direction.

Such optical anisotropy can be expressed by a refractive index ellipsoid as well known. For example, in the case of polymethylmethacrylate (PMMA), the refractive index of the bond unit [—CH ₂ —C (CH ₃ ) (COOCH ₃ ) —] due to methyl methacrylate molecules is relatively small in the orientation direction. The direction perpendicular to the direction is relatively large and npr <nvt. Therefore, the refractive index ellipsoid when viewed on a macro scale is vertically long. Thus, the difference Δn (= npr−nvt) between the refractive index npr related to the polarization component in the direction parallel to the alignment direction and the refractive index nvt related to the polarization component in the direction perpendicular to the alignment direction is This is called the birefringence value.

  The birefringence value Δn of a typical polymer resin used as an optical resin material is −0.100 for polystyrene, −0.0043 for polymethyl methacrylate, +0.210 for polyphenylene oxide, +0.106 for polycarbonate, and polyvinyl chloride. Is 0.027, polyethylene terephthalate is +0.105, and polyethylene is +0.044. In this specification, the birefringence resulting from the orientation of the polymer chain is referred to as orientation birefringence. When the birefringence value Δn has a positive sign (Δn> 0), the birefringence sign is positive. The sign of the refraction value Δn being negative (Δn <0) is expressed as “the sign of birefringence is negative”.

  Such orientation birefringence is a major problem when polarization characteristics are involved in the application or application of optical resin materials. A typical example is an optical disk. When an optical element disposed in the optical path of an optical laser for writing / erasing, for example, a disk itself or a lens exhibits birefringence, reading or writing is performed. Will adversely affect the accuracy.

  Conventionally, various contrivances for reducing the orientation birefringence in the optical resin material have been made, and one representative example is disclosed in International Publication No. WO96 / 06370. This technology adds a low-molecular substance that can be aligned in the same direction as the alignment direction of the bond chain to the matrix made of a transparent polymer resin when the polymer chain of the polymer resin in the matrix is aligned by external force. The birefringence of the low molecular weight material counteracts the orientation birefringence of the polymer resin.

  In this technique, the polymer resin forming the matrix has an orientation birefringence having a positive or negative sign, but the low-molecular substance added to the polymer resin has an orientation birefringence in the polymer resin. Is birefringent with the opposite sign, and a low birefringence optical resin material is obtained by utilizing the fact that the birefringence of the two is canceled out. In other words, in this optical resin material, the polymer chain undergoes orientation when subjected to an action such as stress from the outside in a process such as molding, and at that time, the added low-molecular substance is also oriented to the polymer chain. The major axis direction of the refractive index ellipsoid in the low molecular weight substance that is oriented in accordance with the orientation of the polymer chain is perpendicular to the major axis direction of the refractive index ellipsoid in the polymer resin. By utilizing this, the birefringence of the polymer resin is reduced in an offset manner, and the low birefringence is realized as a whole.

Such technology has the following advantages.
1) Depending on the type of polymer resin and low-molecular substance to be combined, one having a total birefringence close to zero can be obtained.
2) Reasonably applicable to any polymer resin.
3) Since the low molecular weight substance does not substantially participate in the polymerization reaction of the polymer resin for the matrix and is not reactive with the monomer that gives the high molecular resin, the combination of the high molecular weight resin and the low molecular weight substance There are relatively few restrictions.
4) The low molecular weight substance generally has a larger optical anisotropy with respect to the refractive index than each unit molecule forming the polymer resin, and obtains a desired effect with a relatively small addition amount. Therefore, the characteristics of the matrix polymer resin can be effectively utilized in the optical resin material.

  However, in the above-described technique for reducing the birefringence of the optical resin material by the addition of a low molecular substance, for example, the selection range of the low molecular substance to be added is naturally limited in relation to the polymer resin for the matrix. . And it is actually difficult to obtain a low molecular weight material exhibiting negative orientation birefringence. That is, among polymer resins widely used as optical resin materials, this applies to polymer resins having a positive birefringence, in addition to polymethyl methacrylate and polystyrene having a negative birefringence. The range of low molecular weight materials that have negative birefringence to be made is narrow, and this method may not be applicable in practice. Specific examples of the polymer resin in which the selection range of the low-molecular substance having a negative birefringence which can be applied due to the positive birefringence is restricted include, for example, polyethylene (Δn: +0.044), norbornene series Resins (Δn: for example +0.0192) can be mentioned.

  The optical resin material used in the present invention has been made in the background as described above, and is an optical resin material made of a polymer resin, without sacrificing the characteristics of the polymer resin. It is possible to provide a low-birefringence optical resin material in which the birefringence of the polymer resin is reliably reduced regardless of its sign, and a method for producing the same, and preferably used for an optical information record carrier I can do it.

  The low birefringence optical resin material used in the present invention is a polymer resin material having transparency mixed with molecular orientation suppressing granules having a size smaller than the wavelength of light. Further, it is characterized in that it is composed of particles made of a substance having isotropic property with respect to polarization or particles having isotropic property in terms of shape. Here, as the molecular orientation suppressing granules, those having higher hardness than the polymer resin material in the orientation treatment are used.

  According to the above configuration, even when the polymer resin material constituting the matrix is birefringent by itself, the alignment treatment is performed in a state in which the molecular alignment suppression particles having specific conditions are mixed. As a result, the degree of orientation of the polymer chain in the polymer resin material is suppressed, and as a result, the degree of birefringence that is expressed is suppressed. Therefore, a preferred optical resin material for use in an optical recording material is can get. And good performance is obtained by forming a specific hard coat layer.

  In the optical resin material of the aspect as described above, when the polymer chain is oriented, the presence of molecular orientation-suppressing granules inhibits a part of the orientation of the polymer chain and suppresses the degree of orientation. As a result, the birefringence expressed is reduced as compared with the case where the alignment treatment is performed in the absence of such molecular alignment suppressing particles.

  In the present invention, the mechanism for reducing the orientation birefringence of the polymer resin material is completely different from that described above. In other words, in the prior art, the low molecular weight material added exhibits a birefringence having a sign opposite to the orientation birefringence in the polymer resin material, and thus the overall offset is low due to the canceling relationship between the two. Although birefringence or low anisotropy is achieved, in the present invention, the degree of orientation is suppressed in the orientation treatment of the polymer resin material.

<1-2. Polymer resin material>
In the present invention, the polymer resin material constituting the matrix of the optical resin material has any transparency necessary for the intended use as the optical resin material, and has other necessary characteristics. The polymer resin material may be used. Basically, there is no particular restriction due to the relationship with the molecular orientation-suppressing particles mixed therein, and therefore the degree of freedom in selecting the polymer resin material is extremely large. However, it is necessary to have a certain level of transparency for use as an optical resin material. In practice, this polymer resin material is preferably a polymer resin material having general suitability as an optical resin material, and particularly suitable characteristics according to a specific application, for example, excellent It is preferable to use one having heat resistance and mechanical strength.

  Specific examples of the polymer resin material used in the present invention include polyolefins such as polyethylene and polypropylene, aromatic vinyl polymers such as polystyrene, poly (meth) acrylates such as polymethyl methacrylate, polyphenylene oxide, and polycarbonate. Polyvinyl chloride, polyethylene terephthalate, polyarylate, polyether sulfone, polyethylene naphthalate, polymethylpentene-1, alicyclic polyolefins (for example, cyclic olefins such as dicyclopentadiene polyolefin and norbornene polyolefin) Ring (co) polymers, hydrogenated (co) polymers thereof, saturated copolymers of cyclic olefins and unsaturated double bond-containing compounds, such as tricyclodecanyl methacrylate Copolymers of alicyclic (meth) acrylates such as cyclohexyl methacrylate and isobornyl methacrylate and (meth) acrylic acid esters such as methyl methacrylate, polysulfone, polyetherimide, amorphous polyamide, polyphenylene ether, and cyclic olefin , Cyclopentadiene, a hydrogenated polymer of a cationic (co) polymer of an aromatic vinyl compound, and the like. Of these, examples of preferable optical characteristics and physical characteristics include polymethyl methacrylate, certain polycarbonates, and alicyclic polyolefin-based polymers, with polycarbonate being most preferable.

<1-3. Molecular Oriented Particle>
Next, a description will be given of a molecular orientation-inhibiting granule that cancels the optical anisotropy of the polymer resin material and reduces the optical anisotropy of the stretched film by being included in the polymer resin material and stretching. In the molecular orientation suppressing particle of the present invention, the size of the molecular orientation suppressing particle needs to be smaller than the wavelength of light.

  The wavelength of light related to the size of the molecular orientation-suppressing granules may be considered based on the wavelength of light applied to an optical device in which the obtained optical resin material is used, and visible light or light in the vicinity thereof is used. In such a case, the size of the molecular orientation suppressing granule needs to be several hundred nanometers or less. For example, when the light is visible light, the size may be several hundred nanometers or less, for example, about 50 to 300 nm. In addition, when the applied light is laser light, a molecular orientation suppressing grain having a size corresponding to the wavelength may be used. When the size of the molecular orientation-suppressing granules is excessive, the resulting optical resin material has reduced transparency due to the presence of the molecular orientation-suppressing granules. In practice, granules having a size level in the preferred range are relatively easy to obtain. Further, it is possible to easily obtain a granule having isotropicity with respect to polarization and a granule having isotropic property with respect to the shape. Moreover, such an isotropic particle can be applied to virtually any polymer resin as a molecular orientation-suppressing particle, and therefore, the polymer resin used in the optical resin material of the present invention can be used. The freedom of choice is also extremely large. In addition, the particles having such characteristics do not substantially affect the optical characteristics other than the birefringence of the polymer resin, and have little influence on the mechanical characteristics.

  When the powder mixed in the polymer resin material is a particle made of a substance having anisotropy with respect to polarization or a particle having anisotropy with respect to the shape, the polymer resin material should be subjected to an orientation treatment. In some cases, the birefringence expressed by can not be effectively reduced. Shape isotropy means that if a grain has anisotropy with respect to polarization, the shape isotropic to such an extent that a regular orientation that causes the polarization anisotropy as a whole is not produced. It means that there is sex. Typical examples of such isotropic shapes are spherical and regular polygons. A particle having an isotropic shape is typically an isotropic shape such as a spherical shape or a regular polygon, but has a substantially isotropic shape. As long as the ratio of the minor axis to the major axis is, for example, 1/10 or more.

  In the present invention, the powder used as the molecular orientation-suppressing granule needs to have a higher hardness than the polymer resin material in the orientation treatment, whereby the polymer chain of the polymer resin material As a result, the degree of orientation of the polymer chain by the orientation treatment is suppressed as a whole.

  A preferred molecular orientation suppressing granule used in the present invention is an alkaline earth metal carbonate crystal having an aspect ratio of 1.5 or more. The alkaline earth metal carbonate crystal of the present invention is a crystal having a cross-sectional equivalent circle diameter of 1 to 50 nm and an aspect ratio of 1.5 or more. A conventional alkaline earth metal carbonate crystal has a limit of about 200 nm (aspect ratio 10) in the crystal growth direction as a crystal having a cross-sectional circle equivalent diameter of about 20 nm. On the other hand, the equivalent circle diameter of the alkaline earth metal carbonate crystal of the present invention is 50 nm or less, and the aspect ratio is 1.5 or more (the length in the crystal growth direction is 750 nm or more).

  The cross-sectional circle equivalent diameter of the alkaline earth metal carbonate crystal used in the present invention is not limited as long as it is 50 nm or less, preferably 2 to 20 nm, and more preferably 5 to 20 nm. The aspect ratio of the alkaline earth metal carbonate crystal of the present invention is not particularly limited as long as it is 1.5 or more, preferably 20 or more, and more preferably 50 or more. In the present invention, even when the aspect ratio is 50 or more, there is no particular problem because it is cut to a length of submicron or less when kneaded with an optical resin.

  The mixing ratio of the molecular orientation suppressing particles to the polymer resin material is not particularly limited as long as it is an effective ratio for reducing the orientation birefringence of the polymer resin material. It is 0.001-20 mass% with respect to the resin material, Preferably it is the range of 0.01-10 mass%. The mixing ratio of the molecular orientation-suppressing granules is preferably small as long as the desired effect can be obtained. When the mixing ratio of the molecular orientation-suppressing granules increases, the transparency and mechanical strength of the obtained optical resin material are increased. The inherent properties of the polymer resin material such as heat resistance may be deteriorated.

The molecular orientation suppressing particles used in the present invention can be preferably manufactured by the following manufacturing method, but is not limited thereto.
(1) An alkaline earth metal carbonate having an aspect ratio of 1.5 or more by reacting an alkaline earth metal ion present at an ion concentration of 0.5 mol / L or less with a carbonate ion under alkaline conditions. A method for producing an alkaline earth metal carbonate crystal, comprising a step of producing a crystal.
(2) At least selected from ammonium carbonate, ammonium hydrogen carbonate, and carbon dioxide gas as a raw material for supplying the carbonate ion using an alkaline earth metal hydroxide or acetate as the raw material for supplying the alkaline earth metal ion One type is used, The manufacturing method as described in said (1) characterized by the above-mentioned.
(3) The process according to (1) or (2) above, wherein the reaction is carried out in the presence of an amino alcohol.
(4) The method according to any one of (1) to (3) above, further comprising a step of drying the produced alkaline earth metal carbonate crystal.
(5) The production method according to any one of (1) to (4) above, further comprising a step of firing the produced alkaline earth metal carbonate crystal.
(6) The method according to any one of (1) to (5), wherein the reaction between the alkaline earth metal and the carbonate ion is performed in the presence of gelatin.
(7) The method according to (6), further comprising a step of decomposing the gelatin.
(8) The production method according to the above (4), wherein the produced alkaline earth metal carbonate crystal is dried by a freeze-drying method or a spray-drying method.
(9) The method according to any one of (1) to (8) above, further comprising a step of coating the surface of the produced alkaline earth metal carbonate crystal with a compound hardly soluble in water.
(10) The production method according to (9), wherein a silane coupling agent or a titanium coupling agent is used as the poorly soluble compound in water.
(11) An alkaline earth metal carbonate crystal having a cross-sectional equivalent circle diameter of 1 to 50 nm and an aspect ratio of 1.5 or more.
(12) Alkaline earth metal carbonate crystals having a cross-sectional circle equivalent diameter of 2 to 20 nm and an aspect ratio of 20 or more.
(13) An alkaline earth metal carbonate crystal produced by the production method according to any one of (1) to (10) above.

The method for producing an alkaline earth metal carbonate crystal according to the present invention comprises reacting an alkaline earth metal ion and carbonate ion under alkaline conditions to produce an alkaline earth metal carbonate crystal having an aspect ratio of 1.5 or more. A step of generating. The alkaline earth metal ion used in the present invention is not particularly limited and may be any metal ion belonging to Group 11 of the periodic table. More specifically, it can be at least one selected from the group consisting of Be ²⁺ , Mg ²⁺ , Ca ²⁺ , Sr ²⁺ , Ba ²⁺ and Ra ²⁺ , preferably Ca ^2+. , Sr ²⁺ , Ba ²⁺ .

  The alkaline earth metal ion can be usually supplied as an alkaline earth metal compound containing an anion. Examples of the alkaline earth metal compound include compounds composed of alkaline earth metal ions and hydroxide ions, halide ions, nitrate ions, sulfate ions, acetate ions, and the like. In particular, it is preferable to use an alkaline earth metal hydroxide or acetate as a supply source of the alkaline earth metal ion, which can provide a dissolution rate suitable for the reaction and can easily purify the generated by-product.

The ion concentration of the alkaline earth metal ion is not particularly limited as long as it is present at a concentration of 0.5 mol / L or less. Preferably, it is 2 × 10 ^{−1 to} 5 × 10 ⁻⁵ mol / L, and more preferably 1 × 10 ⁻¹ to 1 × 10 ⁻⁴ mol / L. If the alkaline earth metal ion concentration is 0.5 mol / L or less, alkaline earth metal carbonate crystals can be grown in the form of needles or rods.

When supplying the alkaline earth metal compound, it is desirable to supply it in consideration of the solubility of the alkaline earth metal compound in the solvent in order to grow the obtained carbonate crystals in the shape of needles or rods. For example, when an alkaline earth metal compound having low solubility in a solvent (for example, Sr (OH) ₂ ) is used, the specified amount of the alkaline earth metal compound is supplied in a state of being mixed in the solvent in advance. it can. On the other hand, when an alkaline earth metal compound having a relatively high solubility (for example, Sr (CH ₃ OO) ₂ ) is used, the alkaline earth metal compound is gradually added to the reaction solvent to prevent the formation of bulk crystals. Alternatively, it is desirable to prepare a concentrated solution in advance and drop it into the reaction solution.

Feedstock carbonate ions used in the method for producing an alkaline earth metal carbonate crystal according to the present invention is not particularly limited, for example, ammonium carbonate _{((NH 4) 2 CO 3} ), bicarbonate draft ammonium (NH ₄ Various carbonates such as HCO ₃ ), sodium carbonate (Na ₂ CO ₃ ), sodium hydrogen carbonate (NaHCO ₃ ), potassium carbonate (K ₂ CO ₃ ), potassium hydrogen carbonate (KHCO ₃ ), and carbon dioxide gas (CO ₂ ) Can be used. Carbon dioxide gas may be directly introduced into the reaction solution, or may be used after being absorbed in a basic solution such as amino alcohol. Among them, it is preferable to use at least one selected from ammonium carbonate, ammonium hydrogen carbonate or carbon dioxide gas, which can volatilize the by-product generated and is easily purified.

  The ion concentration in the carbonate ion reaction system is not particularly limited. Even when the ion concentration is equal to or higher than the ion concentration of the alkaline earth metal ion used (for example, when excessive carbonate ions are present in the solvent), Concentration may be used.

  The reaction between the alkaline earth metal and the carbonate ion in the method for producing carbonate crystals is performed under alkaline conditions. In the present specification, “alkaline conditions” means that the pH value of a solution containing an alkaline earth metal and carbonate ions is 10 or more, and the pH value is preferably 10 to 13.8. 13.8 is more preferable, and 12 to 13.8 is most preferable.

  In the present invention, the reaction between the alkaline earth metal ion and the carbonate ion includes, for example, amino alcohols, guanidines, amidines, in addition to inorganic bases such as lithium hydroxide, sodium hydroxide, and potassium hydroxide. It can be carried out in the presence of an organic base. By using such a base, acicular or rod-like crystals can be obtained. In particular, it is preferable to use amino alcohols (for example, 2-aminoethanol, dimethylaminoethanol, diethylaminoethanol, diethanolamine, triethanolamine, etc.) that are easy to volatilize and that allow easy purification of carbonate crystals of alkaline earth metals.

  The reaction between the alkaline earth metal and carbonate ions in the carbonate crystal production method is carried out in a suitable solvent. The solvent used in the production method of the present invention is not particularly limited as long as it can dissolve the alkaline earth metal compound and the carbonate compound and can react the alkaline earth metal ion and the carbonate ion in the reaction. For example, water, alcohols, the above amino alcohols, or a mixed solvent of water and these organic solvents can be used as the solvent of the present invention. In particular, water or a mixed solvent of water and amino alcohol is preferable.

  The reaction between the alkaline earth metal and carbonate ions in the carbonate crystal production method is carried out in the solvent, but the dispersion is performed from the viewpoint of improving the dispersibility of the produced alkaline earth metal carbonate crystal. It is preferable to use an agent. Examples of the dispersant that can be used for such a purpose include anionic surfactants, nonionic surfactants, polyvinyl alcohol, polyethylene glycol, carrageenan, and gelatin. Among these, gelatin is preferably used.

When the alkaline earth metal ion and carbonate ion are reacted, the mixing order of the alkaline earth metal ion and carbonate ion is not particularly limited. For example, a solution containing carbonate ions may be mixed and reacted in a solution containing alkaline earth metal, or a solution containing alkaline earth metal ions may be added to a solution containing carbonate ions. Furthermore, both solutions may be mixed simultaneously. In addition, the mixing speed in the case of mixing both ions can be adjusted to an ion concentration of 0.5 mol / L or less in order to obtain a needle-like or rod-like alkaline earth metal carbonate crystal having an aspect ratio of 1.5 or more. It can be determined as appropriate. However, since the reaction takes time when the addition rate is too slow, the ion concentration and mixing rate in each solution are about 10 ⁻² to 10 ³ mL / min, preferably 10 ⁻¹ to 10 ² mL / min. It is desirable to adjust.

  In the method for producing carbonate crystals, an alkaline earth metal carbonate crystal having an aspect ratio of 1.5 or more can be produced by a reaction between the alkaline earth metal and carbonate ions. In the present specification, the “aspect ratio” refers to the ratio of the average length in the crystal growth direction to the average cross-sectional circle equivalent diameter of the alkaline earth metal carbonate crystal. In addition, the “equivalent diameter of the cross-sectional circle” referred to here is a diameter of a circle when the alkaline earth metal carbonate crystal is assumed to have a circular cross section. If the aspect is small, minute voids are likely to be formed around the particles when stretched, which results in haze, which is undesirable in terms of optical performance. The aspect ratio of the alkaline earth metal carbonate crystal produced by the production method of the present invention is 15 or more, preferably 20 or more, and more preferably 50 or more.

  The carbonate crystal production method described above can obtain the desired alkaline earth metal carbonate crystal by separating, purifying and drying the produced alkaline earth metal carbonate crystal. When gelatin is used in the reaction between metal ions and carbonate ions, it is preferable to decompose the gelatin in the gelatin aqueous solution and dry the produced alkaline earth metal carbonate crystals. Purification by centrifugation or decantation may be performed before and after gelatin degradation. By decomposing gelatin, if gelatin is present in the drying step, it can act as a binder between alkaline earth metal carbonate crystals and prevent formation of massive crystals. In order to decompose gelatin, in the production method of the present invention, for example, gelatin degrading enzyme (actase) or the like can be used.

  In the step of drying the produced alkaline earth metal carbonate crystal, various drying methods can be used. Among them, it is preferable to dry the alkaline earth metal carbonate crystal using a freeze-drying method or a spray-drying method from the viewpoint of preventing the formation of a bulk crystal. Moreover, it can also bake after drying. The firing temperature can be arbitrarily set at 100 ° C. or higher and below the crystal decomposition temperature.

  The alkaline earth metal carbonate crystal is preferably coated in advance with a water-insoluble compound on the crystal surface from the viewpoint of purification or suppression of crystal growth in the optical resin. The water-insoluble compound used for coating the crystal surface is not particularly limited, and examples thereof include silane coupling agents, titanium coupling agents, and polymers compatible with optical resins, among which silane coupling agents. Or a titanium coupling agent is preferable.

  Examples of silane coupling agents that can be produced by the production method of the present invention include tetraethoxysilane, vinylethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, and the like. Examples of the coupling agent include titanium isopropoxide and compounds marketed under the trade name of Plenact (manufactured by Ajinomoto Fine Techno Co., Ltd.) (for example, KR138S, KR44, KRET, etc.).

  In addition to the above steps, the production method of the present invention can further have steps (for example, a stirring step, a separation step, a purification step, etc.) used in a general method for producing carbonate crystals as necessary. As conditions in other processes, conditions in a general manufacturing process can be used.

<1-4. Manufacturing Method of Low Birefringence Optical Resin Material>
The method for producing the low birefringence optical resin material used in the present invention can be produced by performing step 3) after performing any of the following steps 1), 1a) and 2).
1) A step of mixing molecular orientation-suppressing granules with a polymerizable material that produces a polymer resin material having transparency by a polymerization reaction. The polymerization process is then entered.
1a) In the above step, the step of mixing the molecular orientation suppressing granules is performed after the polymerization step is started.
2) The process of mixing a molecular orientation suppression granule in the solution of the polymeric resin material which has transparency.
3) The process of extending | stretching the polymeric resin material which has transparency in which the molecular orientation suppression granule was mixed.

  In order to produce the low birefringence optical resin material used in the present invention, a monomer or a composition for producing a polymer resin having transparency by a polymerization reaction is prepared, and the polymerization reaction of this polymerizable material is started. In the previous stage, the molecular orientation suppression particles are mixed and dispersed sufficiently, and after adding an appropriate polymerization initiator, chain transfer agent, etc., the polymerization reaction is started by supplying energy such as heating or ultraviolet irradiation. It is possible to adopt a method of making it proceed.

  Here, the kind and amount of the polymerization initiator and chain transfer agent may be selected according to the same criteria as in the case of a normal polymerization reaction. For example, in the case of thermal polymerization, a peroxide such as benzoyl peroxide can be used as a thermal polymerization initiator. In the case of ultraviolet irradiation, benzoin methyl ether, which is an ultraviolet radical polymerization initiator, can be used. As a chain transfer agent, n-butyl mercaptan or the like can be used in any case. This production method is advantageous in that a polymer resin mixed with molecular orientation-suppressing granules can be directly produced by completing the polymerization reaction.

  In addition, after the start of the polymerization reaction of the monomer that forms the polymer resin or the composition thereof and before the completion of the polymerization reaction, that is, in a state where the polymerization reaction is performed to some extent and a polymerizable oligomer exists. There may be used a method in which the molecular orientation suppressing granules are mixed and sufficiently dispersed, and then the polymerization reaction is completed. Also in this manufacturing method, the polymer resin material mixed with the molecular orientation suppressing particles can be directly manufactured by completing the polymerization reaction.

  In the above method, the molecular orientation-suppressed granules may be subjected to surface treatment in advance with a surface treatment agent (binder) having a high affinity for the monomer or the composition thereof or the generated polymer resin. Preferably, this makes it possible to increase the dispersibility of the molecular orientation-suppressing granules in the polymer resin constituting the matrix. The treatment with the surface treatment agent can be performed as a polymerization reaction and a series of steps.

  In the present invention, a polymer resin material having transparency by a polymerization reaction is manufactured, and this is heated and melted, and a molecular orientation-inhibiting granule is added thereto and kneaded. A low birefringence optical resin material in which the suppression particles are uniformly dispersed can be produced.

  Alternatively, the object can also be achieved by a method in which molecular orientation-suppressing granules are added and uniformly dispersed in a solution obtained by dissolving a polymer resin material in a suitable solvent, and then the solvent is removed by evaporation or the like. An optical resin material can be manufactured.

  According to such a method of mixing molecular orientation-suppressing granules into a polymer resin material solution, it is easy to disperse the finely powdered molecular orientation-suppressing granules sufficiently uniformly, and the polymer resin Since there is no need to heat the material, the thermal deterioration does not occur, and the optical characteristics and mechanical characteristics of the polymer resin material are not impaired. As a result, an optical resin material having good characteristics can be obtained. can get. Moreover, it is also possible to use the solution in which the molecular orientation suppressing granules are dispersed for production of a product such as a film as it is. Also in these methods, it is preferable to use molecular orientation-suppressed granules that have been surface-treated in advance with an appropriate surface-treating agent.

  Optical resin materials mixed with molecular orientation-suppressing granules obtained by the above method usually do not exhibit birefringence because the polymer chain of the polymer resin is not oriented as it is. is there. The optical resin material in which the molecular orientation suppressing particles are mixed is used as a raw material for various optical components and optical materials. As in the case of ordinary optical resin materials, it is a practical product. In order to be used for production, it is preferably pelletized by suitable means. The pelletized optical resin material is molded into a desired shape by a normal molding technique excellent in mass productivity such as injection molding or extrusion molding to obtain a product.

  In the matrix of the polymer resin forming the molded product, the polymer chain is generally oriented in a specific direction due to the action of an external force in the molding process, and thus orientation birefringence occurs. Orientation can be performed by applying an external force in a specific direction by a processing process such as an appropriate molding process or stretching process, but the alignment process in the present invention is performed in a specific direction of the polymer chain of the polymer resin material. Any method may be used as long as the method is oriented, and the specific means is not limited. In this alignment process, as a result of the molecular alignment suppression particles mixed in the polymer resin material exhibiting the action of inhibiting the alignment of the polymer chain of the polymer resin, the polymer to be expressed by the alignment treatment Compared with the case where the birefringence of the resin material is reduced and no molecular orientation-suppressing granules are contained, the birefringence of the entire optical resin material is considerably small.

  For example, in the injection molding process, polymer chains are oriented because high shear stress is generated in the polymer resin near the wall of the mold or near the gate of the mold, and in the extrusion molding process, Although orientation occurs in the polymer chain of the polymer resin at the time of take-up or the like, since the degree of orientation of these polymer chains is suppressed, the resulting birefringence becomes small. In addition, when a film made of a polymer resin material mixed with molecular orientation suppressing granules is stretched, orientation of the polymer chain of the polymer resin occurs, so that it is large when no molecular orientation suppressing granules are contained. Although birefringence is exhibited, the stretched film obtained has low birefringence due to the inclusion of molecular orientation-suppressing granules.

  The molded optical resin material and the stretched optical resin material obtained as described above have extremely low birefringence, and the degree thereof depends on the content ratio of the molecular orientation suppressing granules and the orientation of the polymer chain. Depending on other conditions, it may be non-birefringent, which does not actually exhibit birefringence. In this specification, the term “low birefringence” simply includes the case of non-birefringence.

<2. Hard coat layer>
In the resin material used in the present invention, it is important not to cause a change in light transmittance of the information recording layer or the light transmitting layer from various external pressures. For this reason, the surface pencil hardness is 2H or more. It is preferable to make it.
In order to improve the scratch resistance of the surface, for example, Japanese Patent Application Laid-Open No. 2003-99982 describes the use of a silicone lubricant, a fluorine lubricant or a fatty acid ester lubricant on the outermost surface. However, this method has a defect that it is strong against a force applied in a direction almost horizontal to the surface but weak against a force applied perpendicular to the surface. Therefore, in order to improve the storage stability of the information record carrier, it is necessary to increase the pencil hardness.

Regarding the pencil hardness, using the test pencil stipulated by JIS-S-6006, according to the pencil hardness evaluation method stipulated by JIS-K-5400, the hardness of the pencil with no scratches observed at a load of 9.8 N Can be sought.
As described above, the required pencil hardness is preferably 2H or more, more preferably 3H or more, and further preferably 4H or more.

In order to achieve such pencil hardness, a hard coat layer made of a cured film formed from a curable composition containing a radiation curable resin may be provided on the light-transmitting low birefringence layer. preferable. Hereinafter, the translucent low birefringence layer according to the present invention is used as a support, and a hard coat layer coated on the support is referred to as a hard coat film, but the hard coat film used in the present invention is as follows. The thing like this is mentioned.
(1) As described in Japanese Patent No. 1815116, in order to increase the hardness of a layer, the resin-forming component of the layer is a polyfunctional acrylate monomer, and this is filled with powdered inorganic filler such as alumina, silica, titanium oxide, etc. A hard coat film in which a coating composition containing an agent and a polymerization initiator is coated on a support.
(2) A hard coat film in which a photopolymerizable composition containing an inorganic charge material composed of silica or alumina surface-treated with alkoxysilane or the like described in Japanese Patent No. 1416240 is further filled with crosslinked organic fine particles.
(3) A hard coat film in which the hard coat layer described in JP-A-2000-52472 has a two-layer structure, and fine particle silica is added to the first layer.
(4) The hard coat layer described in JP-A No. 2000-71392 has a two-layer structure, the lower layer uses a cured resin layer made of a blend of a radical curable resin and a cationic curable resin, and the upper layer is made of only the radical curable resin. Hard coat film using a cured resin layer.
(5) A hard coat film produced by melt-kneading and extrusion molding the filler and resin described in JP-A No. 2002-248619.

These hard coat films include cases where sufficient hardness cannot be obtained as described in the above specification. In this case, the desired hardness can be obtained by improving the following preparation methods.
(1) Increase in the number of functional groups of the polyfunctional alkyl ester monomer, increase in the amount of inorganic filler and initiator (2) increase in the inorganic filler (3) increase in the amount of silica in the first layer (4) ratio of radical curable resin Increase (5) Increase in filler

Among these, it is preferable that the hard coat layer is composed of at least a polyfunctional acrylic acid monomer and a powder filler, and the filler is contained in an amount of 5 to 60% by weight. By adding fine particles, the amount of cure shrinkage of the hard coat layer can be reduced, which is preferable because adhesion to the support can be improved and curling can be reduced. As the fine particles, any of inorganic fine particles, organic fine particles, and organic-inorganic composite fine particles can be used. Examples of the inorganic fine particles include silicon dioxide particles, titanium dioxide particles, zirconium oxide particles, and aluminum oxide particles. Such inorganic fine particles are generally hard, and by filling the hard coat layer, not only the shrinkage upon curing can be improved, but also the surface hardness can be increased.
However, since the fine particles generally tend to increase haze, the filling method is adjusted in view of the balance of each necessary characteristic.

In general, inorganic fine particles have low affinity with organic components such as the polymer of the present invention and polyfunctional vinyl monomers, so that they may form aggregates or crack the hard coat layer after curing by simply mixing them. . In the present invention, in order to increase the affinity between the inorganic fine particles and the organic component, the surface of the inorganic fine particles can be treated with a surface modifier containing an organic segment. The surface modifier preferably has a functional group capable of forming a bond with or adsorbing to the inorganic fine particles and a functional group having high affinity with the organic component in the same molecule.
Examples of the surface modifier having a functional group capable of binding or adsorbing to inorganic fine particles include metal alkoxide surface modifiers such as silane, aluminum, titanium, and zirconium, phosphate groups, sulfate groups, sulfonate groups, carboxylic acid groups, and the like. A surface modifier having an anionic group is preferred.
Furthermore, the functional group having a high affinity with the organic component may be simply a combination of the organic component and the hydrophilicity / hydrophobicity, but a functional group that can be chemically bonded to the organic component is preferable, particularly an ethylenically unsaturated group, Or a ring-opening polymerizable group is preferable.
A preferred inorganic fine particle surface modifier in the present invention is a curable resin having a metal alkoxide or an anionic group and an ethylenically unsaturated group or a ring-opening polymerizable group in the same molecule.

  Representative examples of these surface modifiers include the following unsaturated double bond-containing coupling agents, phosphate group-containing organic curable resins, sulfate group-containing organic curable resins, carboxylic acid group-containing organic curable resins, and the like. It is done.

_{S-1 H 2 C = C} (X) COOC 3 H 6 Si (OCH 3) 3
_{S-2 H 2 C = C} (X) COOC 2 H 4 OTi (OC 2 H 5) 3
_{S-3 H 2 C = C} (X) COOC 2 H 4 OCOC 5 H 10 OPO (OH) 2
S-4 (H ₂ C═C (X) COOC ₂ H ₄ OCOC ₅ H ₁₀ O) ₂ POOH
_{S-5 H 2 C = C} (X) COOC 2 H 4 OSO 3 H
_{S-6 H 2 C = C} (X) COO (C 5 H 10 COO) 2 H
S-7 H ₂ C═C (X) COOC ₅ H ₁₀ COOH
S-8 3- (Glycidyloxy) propyltrimethoxysilane

In the above S-1 to S-7, X represents a hydrogen atom or CH ₃ .

The surface modification of these inorganic fine particles is preferably performed in a solution. When inorganic fine particles are mechanically finely dispersed, a surface modifier is present together, or after finely dispersing inorganic fine particles, the surface modifier is added and stirred, or further before finely dispersing inorganic fine particles Alternatively, the surface may be modified (if necessary, heated, dried and then heated, or changed in pH), and then finely dispersed.
As the solution for dissolving the surface modifier, an organic solvent having a large polarity is preferable. Specific examples include known solvents such as alcohols, ketones and esters.

The organic fine particles are not particularly limited, but polymer particles composed of monomers having an ethylenically unsaturated group, such as polymethyl methacrylate, polyethyl methacrylate, polyethyl acrylate, polybutyl acrylate, polyethylene, polypropylene, polystyrene Etc., and polymer particles comprising the general formulas (1) and (3) described later in the present specification are preferably used. Besides, polysiloxane, melamine resin, benzoguanamine resin, polytetrafluoroethylene, polycarbonate, nylon, polyvinyl Examples thereof include resin particles such as alcohol, polytetrafluoroethylene, polyethylene terephthalate, polyvinyl chloride, acetyl cellulose, nitrocellulose, and gelatin. These particles are preferably crosslinked.
As a disperser for refining fine particles, it is preferable to use ultrasonic waves, dispersers, homogenizers, dissolvers, polytrons, paint shakers, sand grinders, kneaders, Eiger mills, dyno mills, coball mills, and the like. As the dispersion medium, the above-mentioned solvent for surface modification is preferably used.

These fillers are preferably inorganic fine particles, and the inorganic particles are most preferably silica in terms of productivity and surface hardness.
The filling amount of the fine particles is preferably 5 to 60% by weight, more preferably 15 to 55% by weight, and most preferably 25 to 50% by weight based on the weight of the hard coat layer after filling.

In the present invention, the following hard coat layer can also be preferably used.
1. A curable composition containing a curable resin for imparting antifouling properties having at least one of a fluorine atom and a silicon atom and a polymerizable group, and obtained by curing the cured composition A hard coat layer formed by curing from a curable composition, wherein the contact angle of water on the surface of the layer is 90 degrees or more.
2. 3. The hard coat layer as described in 1 or 2 above, wherein the hard coat layer has a surface elastic modulus of 4.0 GPa to 10 GPa.
3. 4. The hard coat layer as described in any one of 1 to 3 above, wherein the thickness of the hard coat layer is from 10 μm to 60 μm.
4). The curable composition is a curable composition that is cured by irradiation with active energy rays, and is a curable resin containing a ring-opening polymerizable group and / or a curing containing two or more ethylenically unsaturated groups in the same molecule. 5. The hard coat layer as described in any one of 1 to 4 above, which contains a functional resin.
5. 6. The hard coat layer as described in 5 above, wherein the curable resin containing a ring-opening polymerizable group is a crosslinkable polymer containing a repeating unit represented by the following general formula (1).
General formula (1)

In general formula (1):
R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
P ¹ represents a monovalent ring-opening polymerizable group or a monovalent group having a ring-opening polymerizable group.
L ¹ represents a single bond or a divalent or higher valent linking group.
Details of the repeating unit represented by the general formula (1) and the crosslinkable polymer containing the repeating unit will be described later.

  6). 6. The hard coat layer as described in 5 above, wherein the ring-opening polymerizable group is a cationic polymerizable group.

Hereinafter, the hard coat layer and the antifouling hard coat layer described in 1 to 6 will be described in detail.
The layer applied to the hard coat film of the present invention (hereinafter simply referred to as “hard coat layer”) is a hard coat layer formed by curing the curable composition. Curing may be active energy ray polymerization or thermal polymerization, but active energy ray curing is preferred from the viewpoint of productivity. As described above, the pencil hardness of the surface of the hard coat layer of the present invention is preferably 2H or more, more preferably 3H or more, and further preferably 4H or more. Furthermore, the contact angle with respect to water on the surface is preferably 90 ° or more, more preferably 97 ° or more from the viewpoint of antifouling properties. Moreover, as an upper limit, 150 degrees or less are preferable and 130 degrees or less are more preferable.
In order to make the contact angle of water on the surface of the hard coat layer within the above range, a curable resin containing a fluorine atom and / or a silicon atom and having a polymerizable group in the curable composition for forming the hard coat layer. Or it can carry out by the method of containing a compound as an antifouling agent. The polymerizable group is preferably a group that polymerizes upon irradiation with active energy rays.

The curable resin as an antifouling agent containing a fluorine atom and / or silicon atom contained in the hard coat layer and having a group that is polymerized by active energy rays is known fluorine-containing curable resin that is polymerized by active energy rays. Or a silicon-containing curable resin, or a curable resin having a skeleton containing a fluorine atom and a skeleton containing a silicon atom.
Further, there is provided an active energy ray-polymerizable resin having a skeleton having a good compatibility with a cured resin mainly constituting a hard coat layer or a metal oxide dispersed in the resin, and a skeleton containing a fluorine atom and / or a silicon atom. Preferably mentioned.
By curing such a curable resin to form a hard coat layer or an antifouling layer, fluorine or silicon can be present on the surface of the hard coat layer.
In the present specification, the antifouling layer constitutes a part of the antifouling hard coat layer. However, for convenience of explanation, the antifouling layer may be described separately from the hard coat layer, but even in that case, the antifouling layer is a layer included in the antifouling hard coat layer.

Specific examples of the curable resin as an antifouling agent used in the hard coat layer include monomers containing fluorine atoms or silicon atoms, copolymers of monomers containing fluorine atoms or silicon atoms, and block copolymers. The polymer or the polymer which made the graft copolymer contain the acryl group is mentioned.
Examples of the fluorine-containing monomer include perfluoroalkyl group-containing (meth) acrylic acid esters such as hexafluoroisopropyl acrylate, heptadecafluorodecyl acrylate, perfluoroalkylsulfonamidoethyl acrylate, and perfluoroalkylamidoethyl acrylate. .
Specifically, acrylate compounds such as 2-perfluorooctylethyl methacrylate, 2-perfluorooctylethyl acrylate (manufactured by Nippon Mektron Co., Ltd.), M-3633, M-3833, R-3633, R-3833 and the like ( Contains polymerizable groups such as Daikin Fine Chemical Laboratory Co., Ltd., AFC-1000, AFC-2000, FA-16, etc. (manufactured by Kyoeisha Chemical Co., Ltd.), MegaFuck 531A (manufactured by Dainippon Ink Co., Ltd.) The compound to be mentioned is mentioned.
As the copolymer containing fluorine, there is a copolymer having a main chain composed only of carbon atoms and a fluorine-containing vinyl monomer polymer unit and a polymer unit having a (meth) acryloyl group in the side chain. Specific examples include a copolymer represented by the following general formula (2).

(In general formula (2), Mf represents a fluorine-containing vinyl monomer, L represents a linking group having 1 to 10 carbon atoms, m represents 0 or 1, X represents a hydrogen atom or a methyl group, and A represents an arbitrary one. Represents a polymerized unit of vinyl monomer, which may be composed of a single component or a plurality of components, where x, y and z represent the mol% of each component, 30 ≦ x ≦ 60, 40 ≦ y Represents a value satisfying ≦ 80 and 0 ≦ z ≦ 65.)

  As the fluorine-containing vinyl monomer represented by Mf in the general formula (2), fluoroolefins (for example, fluoroethylene, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, etc.), a part of (meth) acrylic acid or complete fluorination Alkyl ester derivatives (for example, biscoat 6FM (trade name, manufactured by Osaka Organic Chemical Co., Ltd.) and M-2020 (trade name, manufactured by Daikin)), perfluoroalkylsulfonic acid methacrylamide, fully or partially fluorinated vinyl ethers and the like can be mentioned. However, perfluoroolefins are preferred, and hexafluoropropylene is particularly preferred from the viewpoints of solubility, transparency, availability, and the like.

  The copolymer used in the present invention has a polymer unit having a (meth) acryloyl group in the side chain as an essential component. The method for introducing the (meth) acryloyl group into the copolymer is not particularly limited. For example, (1) after synthesizing a polymer having a nucleophilic group such as a hydroxyl group or an amino group, (meth) acrylic acid is used. A method in which chloride, (meth) acrylic anhydride, (meth) acrylic acid and methanesulfonic acid mixed acid anhydride, etc. are allowed to act; (2) the polymer having the nucleophilic group in the presence of a catalyst such as sulfuric acid ( (3) a method of allowing a methacrylic acid to act, (3) a method of causing a compound having both an isocyanate group such as methacryloyloxypropyl isocyanate and a (meth) acryloyl group to act on the polymer having the nucleophilic group, and (4) a polymer having an epoxy group. (5) A method in which (meth) acrylic acid is allowed to act after the synthesis of (5) a polymer having a carboxyl group, Method of reacting a compound having both a carboxy group and a (meth) acryloyl group, and a method of performing dehydrochlorination after obtained by polymerizing a vinyl monomer having a (6) 3-chloropropionic acid ester moiety. Among these, in the present invention, it is particularly preferable to introduce a (meth) acryloyl group by the method (1) or (2) for a polymer containing a hydroxyl group.

  If the composition ratio of these (meth) acryloyl group-containing polymerization units is increased, the film strength is improved. Although it varies depending on the type of the fluorine-containing vinyl monomer polymerization unit, the (meth) acryloyl group-containing polymerization unit in the copolymer represented by the general formula (2) preferably occupies 40 to 80 mol%. It is more preferable to occupy mol%, and it is particularly preferable to occupy 50 to 70 mol%.

  In the copolymer useful for the present invention, in addition to the above-mentioned fluorine-containing vinyl monomer polymerization unit and the polymerization unit having a (meth) acryloyl group in the side chain, the adhesion to the support represented by A in the general formula (2) Other vinyl monomers can be appropriately copolymerized from various viewpoints such as adjustment of Tg of the polymer (contributing to film hardness), solubility in a solvent, transparency, slipperiness, dustproof / antifouling properties, and the like. A plurality of these vinyl monomers may be combined depending on the purpose, and are preferably introduced in the range of 0 to 65 mol% in the copolymer in total, and in the range of 0 to 40 mol%. More preferably, it is particularly preferably in the range of 0 to 30 mol%.

The vinyl monomer unit that can be used in combination is not particularly limited. For example, olefins (ethylene, propylene, isoprene, vinyl chloride, vinylidene chloride, etc.), acrylic esters (methyl acrylate, ethyl acrylate, butyl acrylate, acrylic acid) 2-ethylhexyl, 2-hydroxyethyl acrylate, glycidyl acrylate, allyl acrylate, trimethoxysilylpropyl acrylate, etc.), methacrylic acid esters (methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate) , 2-hydroxyethyl methacrylate, glycidyl methacrylate, allyl methacrylate, trimethoxysilylpropyl methacrylate, etc.), styrene derivatives (styrene, p-hydroxymethylstyrene, p-methoxystyrene) Etc.), vinyl ethers (methyl vinyl ether, ethyl vinyl ether, isopropyl vinyl ether, t-butyl vinyl ether, cyclohexyl vinyl ether, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, glycidyl vinyl ether, allyl vinyl ether, etc.), vinyl esters (vinyl acetate, vinyl propionate, Vinyl butyrate, vinyl cinnamate, etc.), unsaturated carboxylic acids (acrylic acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, etc.), acrylamides (N, N-dimethylacrylamide, N-tertbutylacrylamide, N-cyclohexyl) Acrylamide etc.), methacrylamides (N, N-dimethylmethacrylamide), acrylonitrile and the like.
Preferred are vinyl ether derivatives and vinyl ester derivatives, and particularly preferred are vinyl ether derivatives.

In the general formula (2), L represents a linking group having 1 to 10 carbon atoms, more preferably a linking group having 1 to 6 carbon atoms, particularly preferably a linking group having 2 to 4 carbon atoms, which is linear. Alternatively, it may have a branched structure, may have a ring structure, and may have a heteroatom selected from O, N, and S.
Preferred examples of L include *-(CH ₂ ) ₂ -O-**, *-(CH ₂ ) ₂ -NH-**, *-(CH ₂ ) ₄ -O-**, *-(CH ₂ ) ₆ -O-**, *-(CH ₂ ) ₂ -O- (CH ₂ ) ₂ -O-**, * -CONH- (CH ₂ ) ₃ -O-**, * -CH ₂ CH (OH) CH ₂ -O-**, * -CH ₂ CH ₂ OCONH (CH ₂ ) ₃ -O-** (* represents the connecting site on the polymer main chain side, ** represents the (meth) acryloyl group side And the like.) And the like. m represents 0 or 1;

  In general formula (2), X represents a hydrogen atom or a methyl group. From the viewpoint of curing reactivity, a hydrogen atom is more preferable.

  x, y, and z represent mol% of each constituent component, and represent values satisfying 30 ≦ x ≦ 60, 40 ≦ y ≦ 80, and 0 ≦ z ≦ 65. Preferably, 35 ≦ x ≦ 55, 45 ≦ y ≦ 75, and 0 ≦ z ≦ 20, and particularly preferably 40 ≦ x ≦ 55, 50 ≦ y ≦ 70, and 0 ≦ z ≦ 10.

  Examples of the silicon-containing monomer include monomers having a siloxane group by a reaction such as polydimethylsiloxane and (meth) acrylic acid. Specific examples of the terminal (meth) acrylate siloxane compound include X-22-164A, X-22-164B, X-22-164C, X-22-2404, X-22-174D, X-22-8201, And X-22-2426 (manufactured by Shin-Etsu Chemical Co., Ltd.).

  At least one of fluorine atom and silicon atom and active energy ray polymerizable group for curable composition layer not containing compound having at least one of fluorine atom and silicon atom and active energy ray polymerizable group In the case of a hard coat film provided with a curable composition layer containing a compound having a curable composition layer containing a compound having at least one of a fluorine atom and a silicon atom and an active energy ray polymerizable group The thickness is preferably 0.05 μm or more and 2 μm or less. If it is too thin, it is difficult to obtain the strength and antifouling effect of the coating film. If it is 1 μm or more, the significance of forming a multilayer structure is reduced, and the range of 0.1 μm to 1 μm is more preferable.

  A group that is polymerized by irradiation with active energy rays is imparted, for example, by introducing a radical polymerizable double bond such as an acrylic group or a cationic polymerizable group such as an epoxy group. The content of the compound having fluorine, silicon and the active energy ray polymerizable group contained in these curable compositions is preferably 0.01 to 20% by mass, more preferably 1 to 15% by mass of the curable resin.

In order for the hard coat layer to have excellent scratch resistance, it is preferable that the hardness of the hard coat layer is large to some extent. From the viewpoint of hardness, the surface elastic modulus of the hard coat layer is preferably about 4.0 GPa or more, more preferably 4.5 GPa or more. In a hard coat layer having a surface elastic modulus of less than 4.0 GPa, sufficient pencil hardness and scratch resistance cannot be obtained. When the surface elastic modulus is expressed in universal hardness, the value is preferably about 250 N / mm ² or more, and more preferably 300 N / mm ² or more.
The surface elastic modulus can be increased by adding inorganic fine particles to the hard coat layer. However, increasing the amount of inorganic fine particles increases the brittleness, so the upper limit of the surface elastic modulus is 10 GPa, preferably 9.0 GPa. Therefore, the preferable range of the surface elastic modulus is 4.0 to 10 GPa, and particularly preferably 4.5 to 9.0 GPa.

  As a result of studying the compatibility of the pencil hardness and brittleness of the hard coat layer, it is effective to apply a hard coat agent having a slightly small hardness but improved brittleness.

The surface elastic modulus is a value obtained using a micro surface hardness tester (manufactured by Fisher Instruments: Fisherscope H100VP-HCU). Specifically, using a diamond pyramid indenter (tip-to-face angle: 136 °), the indentation depth is measured under an appropriate test load within a range where the indentation depth does not exceed 1 μm. This is the elastic modulus obtained from the change in load and displacement over time.
Further, the surface hardness can be obtained as a universal hardness by using the above-mentioned micro surface hardness tester. The universal hardness is a value obtained by measuring the indentation depth of a quadrangular pyramid indenter under a test load and dividing the test load by the surface area of the indent calculated from the geometric shape of the indent generated by the test load.
It is known that there is a positive correlation between the surface elastic modulus and the universal hardness.

  When the thickness of the hard coat layer is increased, the pencil hardness is improved, but it is difficult to bend the film, and further, cracking due to bending tends to occur. 1-20 micrometers is preferable and, as for the thickness of the hard-coat layer of this invention, 2-15 micrometers is more preferable. More preferably, it is 2.5-10 micrometers, and 3-7 micrometers is the most preferable.

  The hard coat layer may be composed of a single layer or a plurality of layers, but is preferably a single layer that is simple in the production process. In this case, the single layer refers to a hard coat layer formed by curing from the same curable composition. If the composition after application and drying is the same composition, it is cured after being applied multiple times. It may be formed. On the other hand, the term “multiple layers” refers to layers that are cured and formed from a plurality of curable compositions having different compositions.

The hard coat layer of the present invention is formed by applying a curable composition that is cured by irradiation with active energy rays and then curing by irradiation with active energy rays. The cure shrinkage ratio of the curable composition by irradiation with active energy rays is 0 to 15%, preferably 0 to 13%, more preferably 0 to 11%.
The curing shrinkage rate is obtained by calculating the density of the curable composition before irradiation with the active energy ray used, for example, UV light, and the density of the curable composition after irradiation curing, and calculating from the values by the following formula A. Value. The density is a value measured (25 ° C.) with MULTIVOLUME PYCNOMETER manufactured by Micrometric.

  Formula A: Volume shrinkage = {1- (density before curing / density after curing)} × 100 (%)

  The curable composition for forming the hard coat layer contains, as a main component, a curable resin that is cured by active energy rays or heat, different from the curable resin as the antifouling agent. A curable composition for forming a hard coat layer (hereinafter also simply referred to as “curable composition”) includes a curable resin having a ring-opening polymerizable group and / or an ethylenic non-polymerizable resin as the curable resin. It is preferable to contain a curable resin having 2 or more (more preferably 3 or more) saturated groups in the same molecule, and it is more preferable to contain both of these two types of curable resins. As a result, the surface hardness of the hard coat layer is increased, and a hard coat film excellent in scratch resistance can be obtained. At the same time, the volume shrinkage rate satisfies the above-described range, curling after curing is reduced, and cracks during handling are less likely to occur. Furthermore, the above-described effect becomes more remarkable by setting the hard coat layer to a certain thickness.

Hereinafter, the curable resin containing a ring-opening polymerizable group that is preferably used in the present invention will be described.
The curable resin containing a ring-opening polymerizable group is a curable resin having a ring structure in which ring-opening polymerization proceeds by the action of a cation, an anion, or a radical, and among them, a heterocyclic group-containing curable resin is preferable. Examples of such curable resins include epoxy derivatives, oxetane derivatives, tetrahydrofuran derivatives, cyclic lactone derivatives, cyclic carbonate derivatives, cyclic imino ethers such as oxazoline derivatives, and the like, and epoxy derivatives, oxetane derivatives, and oxazoline derivatives are particularly preferable.
In the present invention, the curable resin having a ring-opening polymerizable group preferably has two or more ring-opening polymerizable groups in the same molecule, more preferably three or more. In the present invention, two or more curable resins having a ring-opening polymerizable group may be used in combination. In this case, a curable resin having one ring-opening polymerizable group in the same molecule and a curable resin having two or more ring-opening polymerizable groups in the same molecule may be combined. Only two or more curable resins having two or more ring polymerizable groups may be combined.

  In the present invention, the curable resin having a ring-opening polymerizable group is not particularly limited as long as it is a curable resin having a cyclic structure as described above. Preferred examples of such curable resins include monofunctional glycidyl ethers, monofunctional alicyclic epoxies, difunctional alicyclic epoxies, diglycidyl ethers (for example, ethylene glycol diglycidyl ether as glycidyl ethers). Bisphenol A diglycidyl ether), trifunctional or higher glycidyl ethers (trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, glycerol triglycidyl ether, tris (glycidyloxyethyl) isocyanurate, etc.) Glycidyl ethers (sorbitol tetraglycidyl ether, pentaerythritol tetraglycyl ether, polyglycidyl ether of cresol novolac resin, phenol novolac resin Polyglycidyl ether, etc.), cycloaliphatic epoxies (Celoxide 2021P, Celoxide 2081, Epolide GT-301, Epolide GT-401 (above, manufactured by Daicel Chemical Industries, Ltd.)), EHPE (produced by Daicel Chemical Industries, Ltd.) , Phenol novolak resin polycyclohexyl epoxy methyl ether, and the like), oxetanes (OX-SQ, PNOX-1009 (manufactured by Toagosei Co., Ltd.), etc.) and the like, but the present invention is not limited thereto. is not.

In the present invention, it is particularly preferable that the curable resin having a ring-opening polymerizable group contains a crosslinkable polymer containing a repeating unit represented by the general formula (1). These crosslinkable polymers are described in detail below.
In general formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, preferably a hydrogen atom or a methyl group.
L ¹ is a single bond or a divalent or higher valent linking group, preferably a single bond, —O—, an alkylene group, an arylene group, and * —COO—, * —CONH—, * linked to the main chain on the * side. -OCO-, * -NHCO-.
P ¹ is a monovalent ring-opening polymerizable group or a monovalent group having a ring-opening polymerizable group. Preferred examples of P ¹ include an epoxy ring, an oxetane ring, a tetrahydrofuran ring, a lactone ring, a carbonate ring, and an oxazoline ring. And monovalent groups having an iminoether ring, and the like. Among these, a monovalent group having an epoxy ring, an oxetane ring or an oxazoline ring is particularly preferred.

In the present invention, the crosslinkable polymer containing the repeating unit represented by the general formula (1) is preferably synthesized by polymerizing a corresponding monomer. In this case, radical polymerization is the simplest and preferable as the polymerization reaction.
Although the preferable specific example of the repeating unit represented by General formula (1) below is shown, this invention is not limited to these.

  In the present invention, the crosslinkable polymer containing the repeating unit represented by the general formula (1) may be a copolymer composed of a plurality of types of repeating units represented by the general formula (1). It may be a copolymer containing a repeating unit other than (1) (for example, a repeating unit not containing a ring-opening polymerizable group). Particularly suitable is a method of controlling the Tg or hydrophilicity / hydrophobicity of the crosslinkable polymer or a copolymer containing a repeating unit other than the general formula (1) for the purpose of controlling the content of the ring-opening polymerizable group of the crosslinkable polymer. It is. As a method for introducing the repeating unit other than the general formula (1), a method of introducing the corresponding monomer by copolymerization is preferable.

  When the repeating unit other than the general formula (1) is introduced by polymerizing the corresponding vinyl monomer, the monomer preferably used is derived from acrylic acid or α-alkylacrylic acid (for example, methacrylic acid). Esters (eg, methyl acrylate, ethyl acrylate, hydroxyethyl acrylate, n-propyl acrylate, i-propyl acrylate, 2-hydroxypropyl acrylate, 2-methyl-2-nitropropyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, t-pentyl acrylate, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-methoxymethoxyethyl acrylate, 2,2,2-trifluoroethyl acrylate 2,2-dimethylbutyl acrylate, 3-methoxybutyl acrylate, ethyl carbitol acrylate, phenoxyethyl acrylate, n-pentyl acrylate, 3-pentyl acrylate, octafluoropentyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, cyclopentyl Acrylate, cetyl acrylate, benzyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, 4-methyl-2-propylpentyl acrylate, heptadecafluorodecyl acrylate, n-octadecyl acrylate, methyl methacrylate, 2,2,2-trifluoro Ethyl methacrylate, tetrafluoropropyl methacrylate, hexafluoropropyl methacrylate, Droxyethyl methacrylate, 2-hydroxypropyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, sec-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, 2-methoxyethyl methacrylate, 2-ethoxyethyl methacrylate, benzyl methacrylate , Heptadecafluorodecyl methacrylate, n-octadecyl methacrylate, 2-isobornyl methacrylate, 2-norbornylmethyl methacrylate, 5-norbornen-2-ylmethyl methacrylate, 3-methyl-2-norbornylmethyl methacrylate, dimethyl Aminoethyl methacrylate),

Amides derived from acrylic acid or α-alkylacrylic acid (for example, methacrylic acid) (for example, Ni-propylacrylamide, Nn-butylacrylamide, Nt-butylacrylamide, N, N-dimethyl) Acrylamide, N-methylmethacrylamide, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, acrylamidopropyltrimethylammonium chloride, methacrylamide, diacetone acrylamide, acryloylmorpholine, N-methylolacrylamide, N-methylolmethacrylamide), acrylic S derived from acids or α-alkyl acrylic acids (acrylic acid, methacrylic acid, itaconic acid, etc.), vinyl esters (eg vinyl acetate), maleic acid or fumaric acid Tellurium (dimethyl maleate, dibutyl maleate, diethyl fumarate, etc.), maleimide (N-phenylmaleimide, etc.), maleic acid, fumaric acid, sodium salt of p-styrenesulfonic acid, acrylonitrile, methacrylonitrile, dienes (For example, butadiene, cyclopentadiene, isoprene), aromatic vinyl compounds (for example, styrene, p-chlorostyrene, t-butylstyrene, α-methylstyrene, sodium styrenesulfonate), N-vinylpyrrolidone, N-vinyloxazolidone, N -Vinyl succinimide, N-vinylformamide, N-vinyl-N-methylformamide, N-vinylacetamide, N-vinyl-N-methylacetamide, 1-vinylimidazole, 4-vinylpyridine, vinylsulfonic acid, vinyl Sodium sulfonic acid, sodium allyl sulfonate, sodium methallyl sulfonate, vinylidene chloride, vinyl alkyl ethers (e.g. methyl vinyl ether), ethylene, propylene, 1-butene, isobutene and the like.

Two or more of these vinyl monomers may be used in combination. Vinyl monomers other than these are listed in Research Disclosure No. Those described in 19551 (1980, July) can be used.
Of these, esters and amides derived from acrylic acid or methacrylic acid, and aromatic vinyl compounds are particularly preferably used.

  As the repeating unit other than the general formula (1), a repeating unit having a reactive group other than the ring-opening polymerizable group can also be introduced. In particular, if you want to increase the hardness of the hard coat layer, or if you want to improve the adhesion between layers when using another functional layer on the support or hard coat layer, include reactive groups other than ring-opening polymerizable groups A method of forming a copolymer is preferable. As a method for introducing a repeating unit having a reactive group other than the ring-opening polymerizable group, a method of copolymerizing a corresponding vinyl monomer (hereinafter referred to as a reactive monomer) is simple and preferable.

  Although the preferable specific example of a reactive monomer is shown below, this invention is not limited to these.

  Hydroxyl group-containing vinyl monomers (eg, hydroxyethyl acrylate, hydroxyethyl methacrylate, allyl alcohol, hydroxypropyl acrylate, hydroxypropyl methacrylate, etc.), isocyanate group-containing vinyl monomers (eg, isocyanatoethyl acrylate, isocyanatoethyl methacrylate, etc.), N -Methylol group-containing vinyl monomers (for example, N-methylol acrylamide, N-methylol methacrylamide, etc.), carboxyl group-containing vinyl monomers (for example, acrylic acid, methacrylic acid, itaconic acid, carboxyethyl acrylate, vinyl benzoate), alkyl halides Vinyl monomers (eg chloromethylstyrene, 2-hydroxy-3-chloropropyl methacrylate), no acid Water-containing vinyl monomers (eg maleic anhydride), formyl group-containing vinyl monomers (eg acrolein, methacrolein), sulfinic acid group-containing vinyl monomers (eg potassium styrenesulfinate), active methylene-containing vinyl monomers (eg acetoacetoxyethyl) Methacrylate), acid chloride-containing monomers (eg acrylic acid chloride, methacrylic acid chloride), amino group-containing monomers (eg allylamine), alkoxysilyl group-containing monomers (eg methacryloyloxypropyltrimethoxysilane, acryloyloxypropyltrimethoxysilane), etc. Can be mentioned.

  In the present invention, the ratio of the repeating unit represented by the general formula (1) in the crosslinkable polymer including the repeating unit represented by the general formula (1) is 1% by mass or more and 100% by mass or less, preferably 30 mass% or more and 100 mass% or less, Especially preferably, they are 50 mass% or more and 100 mass% or less.

  The range of the preferable mass average molecular weight (measured by gel permeation chromatography, converted to polyethylene glycol) of the crosslinkable polymer containing the repeating unit represented by the general formula (1) is 1,000 or more and 1,000,000 or less, more preferably 3000 or more. 200,000 or less. Most preferably, it is 5000 or more and 100,000 or less.

  Although the preferable example of the crosslinkable polymer containing the repeating unit represented by General formula (1) below is shown in Table 1, this invention is not limited to these. In addition, the repeating unit represented by the general formula (1) mentioned above with the specific example is represented by the number of the specific example given above, and the repeating unit derived from the copolymerizable monomer describes the monomer name. The copolymer composition ratio is indicated by mass%.

As described above, the curable composition that is cured by active energy rays for forming the hard coat layer includes two curable resins containing a ring-opening polymerizable group and two ethylenically unsaturated groups in the same molecule. It is preferable to contain both the curable resin containing above.
Hereinafter, the curable resin containing two or more ethylenically unsaturated groups in the same molecule will be described in detail.

Preferred types of ethylenically unsaturated groups are acryloyl group, methacryloyl group, styryl group and vinyl ether group, particularly preferably acryloyl group.
A curable resin (monomer or oligomer) containing one or two ethylenically unsaturated groups may be used in combination with a curable resin containing two or more ethylenically unsaturated groups in the same molecule.
Furthermore, the molecular weight of several functional acrylate monomers having 2 to 6 acrylate groups in the molecule and several acrylate groups in the molecule called urethane acrylate, polyester acrylate and epoxy acrylate is several hundred. To several thousand oligomers can be preferably used as the curable resin of the present invention.

  Specific examples of the curable resin having two or more acrylic groups in the same molecule include ethylene glycol diacrylate, 1,6-hexanediol diacrylate, bisphenol-A diacrylate, trimethylolpropane triacrylate, ditrile. Obtained by reaction of polyol polyacrylates such as methylolpropane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate, and hydroxyl-containing acrylates such as polyisocyanate and hydroxyethyl acrylate. The urethane acrylate etc. which can be mentioned can be mentioned. A curable resin having two or more acrylic groups in the same molecule is more preferable.

Moreover, in this invention, the crosslinkable polymer containing the repeating unit represented by following General formula (3) can also be preferably used as curable resin which has a 2 or more ethylenically unsaturated group in the same molecule. Hereinafter, the crosslinkable polymer containing the repeating unit represented by the general formula (3) will be described in detail.
General formula (3)

In the general formula (3), R ² represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, preferably a hydrogen atom or a methyl group.
P ² represents a monovalent ethylenically unsaturated group or a monovalent group having an ethylenically unsaturated group.
L ² represents a single bond or a divalent or higher linking group, preferably a single bond, —O—, an alkylene group, an arylene group, and * —COO—, * —CONH—, * linked to the main chain on the * side. -OCO-, * -NHCO-.
P ² is preferably an acryloyl group, a methacryloyl group, a styryl group or a monovalent group containing any of these groups, and most preferably an acryloyl group or a monovalent group containing the same.

The crosslinkable polymer containing the repeating unit represented by the general formula (3) may be synthesized by (i) a method in which a corresponding monomer is polymerized to directly introduce an ethylenically unsaturated group, and (ii) any You may synthesize | combine by the method of introduce | transducing an ethylenically unsaturated group into a polymer obtained by superposing | polymerizing the monomer which has a functional group by polymer reaction. Moreover, it can also synthesize | combine combining the method of said (i) and (ii). Examples of the polymerization reaction include radical polymerization, cationic polymerization, and anionic polymerization.
The method of (i) above directly produces an unsaturated group-containing polymer by utilizing the difference in polymerizability between the ethylenically unsaturated group consumed by the polymerization reaction and the ethylenically unsaturated group remaining in the crosslinkable polymer. Is possible. For example, when P ² in the general formula (3) is an acryloyl group, a methacryloyl group, or a monovalent group containing any one of these, the polymerization reaction for generating a crosslinkable polymer is changed to cationic polymerization as described above ( The crosslinkable polymer of the general formula (3) can be obtained by the method i). On the other hand, when P ² is a styryl group or a monovalent group containing a styryl group, gelation is likely to proceed by any of radical polymerization, cationic polymerization, and anionic polymerization. The crosslinkable polymer of the general formula (3) is synthesized by a technique.

Thus, the method using the polymer reaction of (ii) above is useful because it is possible to obtain a crosslinkable polymer regardless of the type of ethylenically unsaturated group introduced into the general formula (3). It is.
In the polymer reaction, (I) for example, a polymer containing a functional group obtained by precuring an ethylenically unsaturated group that removes hydrochloric acid from a 2-chloroethyl group is generated and then converted into a functional group (elimination reaction, oxidation). (II) After the formation of a polymer containing any functional group, the bond formation reaction proceeds with the functional group in the polymer and is shared. Examples include a method of reacting a reactive monomer having both a functional group capable of forming a bond and an ethylenically unsaturated group. These methods (I) and (II) may be performed in combination.
The bond formation reaction referred to here can be used without particular limitation as long as it is a reaction that forms a covalent bond in the bond formation reaction generally used in the field of organic synthesis. On the other hand, since the ethylenically unsaturated group contained in the crosslinkable polymer may be thermally polymerized and gelled during the reaction, the reaction proceeds at the lowest possible temperature (preferably 60 ° C. or less, particularly preferably room temperature or less). Those that do are preferred. A catalyst may be used for the purpose of promoting the progress of the reaction, and a polymerization inhibitor may be used for the purpose of suppressing gelation.

  Although the example of the combination of the functional group in which a preferable polymer bond formation reaction advances below is given, this invention is not limited to these.

As a combination of functional groups that the reaction proceeds at heating or room temperature,
(A) With respect to the hydroxyl group, epoxy group, isocyanate group, N-methylol group, carboxyl group, alkyl halide, acid anhydride, acid chloride, active ester group (for example, sulfate ester), formyl group, acetal group,
(B) hydroxyl group, mercapto group, amino group, carboxyl group, N-methylol group with respect to isocyanate group,
(C) With respect to the carboxyl group, an epoxy group, an isocyanate group, an amino group, an N-methylol group,
(D) N-methylol group, isocyanate group, N-methylol group, carboxyl group, amino group, hydroxyl group,
(E) With respect to the epoxy group, hydroxyl group, amino group, mercapto group, carboxyl group, N-methylol group,
(F) a sulfinic acid group, an amino group,
(G) Hydroxyl group, mercapto group, active methylene group with respect to formyl group,
(H) For mercapto groups, formyl groups, vinyl groups (allyl groups, acrylic groups, etc.), epoxy groups, isocyanate groups, N-methylol groups, carboxyl groups, alkyl halides, acid anhydride chlorides, active ester groups ( Eg sulfuric ester),
(Li) Amino group, formyl group, vinyl group (allyl group, acrylic group, etc.), epoxy group, isocyanate group, N-methylol group, carboxyl group, alkyl halide, acid anhydride, acid chloride, active ester group (For example, sulfate ester), and the like.

  Although the preferable specific example of a reactive monomer is shown below, this invention is not limited to these.

  Hydroxyl group-containing vinyl monomers (eg, hydroxyethyl acrylate, hydroxyethyl methacrylate, allyl alcohol, hydroxypropyl acrylate, hydroxypropyl methacrylate, etc.), isocyanate group-containing vinyl monomers (eg, isocyanatoethyl acrylate, isocyanatoethyl methacrylate, etc.), N -Methylol group-containing vinyl monomers (for example, N-methylol acrylamide, N-methylol methacrylamide, etc.), epoxy group-containing vinyl monomers (for example, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, CYCLOMER-M100, A200 (Daicel Chemical Industries ( Etc.)), carboxyl group-containing vinyl monomers (eg acrylic acid, methacrylic acid) Acid, itaconic acid, carboxyethyl acrylate, vinyl benzoate), alkyl halide-containing vinyl monomers (eg, chloromethylstyrene, 2-hydroxy-3-chloropropyl methacrylate), acid anhydride-containing vinyl monomers (eg, maleic anhydride), Formyl group-containing vinyl monomer (for example, acrolein, methacrolein), sulfinic acid group-containing vinyl monomer (for example, potassium styrenesulfinate), active methylene-containing vinyl monomer (for example, acetoacetoxyethyl methacrylate), vinyl group-containing vinyl monomer (for example, allyl methacrylate, Allyl acrylate), acid chloride-containing monomers (for example, acrylic acid chloride, methacrylic acid chloride), amino group-containing monomers (for example, allylamine), and the like. That.

The polymer containing any functional group described in (II) above can be obtained by polymerizing a reactive monomer having both a reactive functional group and an ethylenically unsaturated group. Moreover, it can also obtain by performing functional group conversion after superposition | polymerization of a precursor monomer with low reactivity like polyvinyl alcohol obtained by modify | denaturating polyvinyl acetate.
As a polymerization method in these cases, radical polymerization is the simplest and preferable.

  Although the preferable specific example of the repeating unit represented by General formula (3) below is shown, this invention is not limited to these.

  In the present invention, the crosslinkable polymer containing the repeating unit represented by the general formula (3) may be a copolymer composed of a plurality of types of repeating units represented by the general formula (3). A copolymer containing a repeating unit other than 3) (for example, a repeating unit not containing an ethylenically unsaturated group) may be used. In particular, it is preferable to control the Tg or hydrophilicity / hydrophobicity of the crosslinkable polymer, or to prepare a copolymer containing a repeating unit other than the general formula (3) for the purpose of controlling the content of the ethylenically unsaturated group of the crosslinkable polymer. It is. As a method for introducing the repeating unit other than the general formula (3), (a) a method of directly introducing the corresponding monomer by copolymerization may be used, (b) a precursor monomer capable of functional group conversion is polymerized, A technique of introducing by polymer reaction may be used. Further, the methods (a) and (b) can be combined and introduced.

  In the case of introducing a repeating unit other than the general formula (3) by polymerizing a corresponding vinyl monomer by the method (a), as a monomer preferably used, in the description of the general formula (1), the general formula (1) Examples of the monomer that is preferably used when a repeating unit other than 1) is introduced by polymerizing a corresponding vinyl monomer are the same as those described above. Two or more of these vinyl monomers may be used in combination. Vinyl monomers other than these are listed in Research Disclosure No. Those described in 19551 (1980, July) can be used. Of these, esters and amides derived from acrylic acid or methacrylic acid and aromatic vinyl compounds are particularly preferably used.

  In addition, when the repeating unit represented by the general formula (3) is introduced by a polymer reaction as in the above (ii) and the reaction is not completed, a functional group or a reactive functional group obtained by precursorizing an ethylenically unsaturated group In the present invention, this can be used without particular limitation.

  Most of the repeating units that do not contain ethylenically unsaturated groups derived from the vinyl monomers listed above can be introduced by polymerizing the above-mentioned (b) functional group-convertable precursor monomers and polymerizing them. It is. On the other hand, the crosslinkable polymer containing the repeating unit represented by the general formula (3) in the present invention may contain a repeating unit other than the general formula (3) that can be introduced only by a polymer reaction. Typical examples include polyvinyl alcohol obtained by modifying polyvinyl acetate, polyvinyl butyral obtained by acetalization reaction of polyvinyl alcohol, and the like. Specific examples of these repeating units are shown below, but the present invention is not limited thereto.

  In the present invention, in the crosslinkable polymer containing the repeating unit represented by the general formula (3), the proportion of the repeating unit represented by the general formula (3) is 1% by mass or more and 100% by mass or less, preferably 30%. It is 50 mass% or more and 100 mass% or less especially preferably.

  The range of the preferred number average molecular weight (measured by gel permeation chromatography, converted to polyethylene glycol) of the crosslinkable polymer containing the repeating unit represented by the general formula (3) is 1,000 or more and 1,000,000 or less, more preferably 3000 or more. 200,000 or less. Most preferably, it is 5000 or more and 100,000 or less.

  Although the preferable example of the crosslinkable polymer containing the repeating unit represented by General formula (3) below is shown in Table 2, this invention is not limited to this. In addition, the repeating unit represented by the general formula (3) and the repeating unit such as polyvinyl alcohol described above with specific examples are represented by the numbers of the specific examples given above, and the repeating unit derived from a copolymerizable monomer. Indicates the name of the monomer and the copolymer composition ratio in mass%.

  Examples of the curable resin having a ring-opening polymerizable group that can be used in the present invention also include polymers containing both repeating units represented by the general formulas (1) and (3). In this case, preferred repeating units of the general formulas (1) and (3) are the same as those described above. Further, even a copolymer containing a repeating unit other than the general formulas (1) and (3) is a copolymer containing a repeating unit having a reactive group other than an ethylenically unsaturated group and a ring-opening polymerizable group. Also good.

  In the crosslinkable polymer containing both repeating units represented by the general formulas (1) and (3), the proportion of the repeating unit represented by the general formula (1) is 1% by mass or more and 99% by mass or less, Preferably they are 20 mass% or more and 80 mass% or less, Most preferably, they are 30 mass% or more and 70 mass% or less, and the ratio in which the repeating unit represented by General formula (3) is contained is 1 mass% or more and 99 mass% or less. The content is preferably 20% by mass or more and 80% by mass or less, and particularly preferably 30% by mass or more and 70% by mass or less.

  The range of the preferable weight average molecular weight (measurement by gel permeation chromatography, polystyrene conversion value) of the crosslinkable polymer containing both repeating units represented by the general formulas (1) and (3) is 1,000 to 1,000,000. More preferably, it is 3000 or more and 200,000 or less. Most preferably, it is 5000 or more and 100,000 or less.

  Although the preferable example of the crosslinkable polymer containing both the repeating units represented by General formula (1) and (3) is shown in Table 3, this invention is not limited to these. In addition, the repeating units represented by the general formulas (1) and (3) and the repeating units such as polyvinyl alcohol described above with specific examples are represented by the numbers of the specific examples given above and are derived from a copolymerizable monomer. The repeating unit is described with the monomer name, and the copolymer composition ratio is indicated by mass%.

  Preferred mixing of a curable resin containing two or more ethylenically unsaturated groups in the same molecule and a curable resin containing a ring-opening polymerizable group, preferably contained in a curable composition for forming a hard coat layer The ratio varies depending on the type of curable resin to be used, and is not particularly limited. However, the ratio of the curable resin containing an ethylenically unsaturated group is preferably 30% by mass or more and 90% by mass or less of the entire curable resin. More preferably, it is 50 mass% or more and 80 mass% or less.

  A curable composition containing a curable resin containing an ethylenically unsaturated group and a curable resin containing a ring-opening polymerizable group (hereinafter, unless otherwise specified, the “curable composition” is the curable property of both of them. When curing a resin-containing composition), it is preferable that the crosslinking reaction of both curable resins proceeds. A preferable crosslinking reaction of the ethylenically unsaturated group is a radical polymerization reaction, and a preferable crosslinking reaction of the ring-opening polymerizable group is a cationic polymerization reaction. In either case, the polymerization reaction can be advanced by the action of active energy rays. Usually, a small amount of radical generator and cation generator (or acid generator) called polymerization initiators can be added and decomposed by active energy rays to generate radicals and cations to proceed the polymerization. . Although radical polymerization and cationic polymerization may be performed separately, it is preferable to proceed simultaneously.

When the curable composition is cured by irradiation with active energy rays, the crosslinking reaction often proceeds at a low temperature, which is preferable.
In the present invention, radiation, gamma rays, alpha rays, electron beams, ultraviolet rays and the like are used as active energy rays. Among them, a method of adding a polymerization initiator that generates radicals or cations using ultraviolet rays and curing with ultraviolet rays is particularly preferable. Further, there may be a case where curing can be further advanced by heating after irradiation with ultraviolet rays, and this method can be preferably used. A preferable heating temperature in this case is 140 ° C. or lower.

Examples of photoacid generators that generate cations by ultraviolet rays include ionic curable resins such as triarylsulfonium salts and diaryliodonium salts, and nonionic curable resins such as nitrobenzyl esters of sulfonic acids. Various known photoacid generators such as curable resins described in “Electronic Materials for Imaging” published by Electronics Materials Research Group, published by Bunshin Publishing Co., Ltd. (1997) can be used. Among these, a sulfonium salt or an iodonium salt is particularly preferable, and PF ₆ ⁻ , SbF ₆ ⁻ , AsF ₆ ⁻ , B (C ₆ F ₅ ) ₄ ^{− and the} like are preferable as a counter ion.

  Examples of polymerization initiators that generate radicals by ultraviolet rays include known radical generators such as acetophenones, benzophenones, Michler's ketone, benzoylbenzoate, benzoins, α-acyloxime esters, tetramethylthiuram monosulfide, and thioxanthone. Can be used. Further, as mentioned above, since sulfonium salts and iodonium salts that are usually used as photoacid generators also act as radical generators upon irradiation with ultraviolet rays, these may be used alone in the present invention. In addition to a polymerization initiator, a sensitizer may be used for the purpose of increasing sensitivity. Examples of the sensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, and thioxanthone derivatives.

  The polymerization initiators may be used in combination, or in the case of a curable resin that generates both radicals and cations alone, etc., can be used alone. The addition amount of the polymerization initiator is 0.1 to 15% by mass relative to the total mass of the ethylenically unsaturated group-containing curable resin and the ring-opening polymerizable group-containing curable resin contained in the curable composition. It is preferable to use in the range, and it is more preferable to use in the range of 1 to 10% by mass.

In the present invention, a crosslinkable polymer having a repeating unit represented by the general formula (1) and a crosslinkable polymer having a repeating unit represented by the general formula (3) (hereinafter referred to as “polymer of the present invention” together) In general, the polymer of the present invention becomes a solid or high-viscosity liquid, and it is difficult to apply alone, and when the polymer is water-soluble or water-dispersed, it should be applied in an aqueous system. However, it is usually applied after being dissolved in an organic solvent. Any organic solvent can be used without particular limitation as long as it can dissolve the polymer of the present invention.
Preferable organic solvents include ketones such as methyl ethyl ketone, alcohols such as isopropanol, esters such as ethyl acetate, and the like. In addition, when the above-mentioned monofunctional or polyfunctional vinyl monomer, or a curable resin having a monofunctional, bifunctional, or trifunctional or higher ring-opening polymerizable group is a low molecular weight curable resin, when these are used in combination, The viscosity of the adhesive composition can be adjusted, and it can be applied without using a solvent.

  The haze of the hard coat layer used in the present invention is preferably 7% or less, more preferably 5% or less, and most preferably 3% or less. The haze evaluation method is a haze value measured using a turbidimeter “NDH-1001DP” manufactured by Nippon Denshoku Industries Co., Ltd., that is, a value automatically measured as (diffused light / total transmitted light) × 100 (%). Was used.

  In the hard coat film of the present invention, the value when curl is expressed by the following formula B is preferably in the range of minus 15 to plus 15, more preferably in the range of minus 12 to plus 12. Is minus 10 to plus 10. The measurement direction of the curl in the sample at this time is measured with respect to the conveyance direction of the support in the case of application in a web form.

(Formula B) Curl = 1 / R
Here, R represents a radius of curvature (m).

Satisfying the mathematical formula B is an important characteristic for preventing cracks and peeling of the film in the production, processing and market handling of the hard coat film. It is preferable that the curl value is in the above range and the curl is small. It is possible to reduce the curl to a high surface hardness within the above range by setting the volume shrinkage ratio before and after curing of the curable composition for forming the hard coat layer to 15% or less.
The curl is measured by using the curl measurement template of Method A in “Measurement Method of Curling of Photographic Film” of JIS K7619-1988. The measurement conditions are 25 ° C., relative humidity 60%, and humidity control time 10 hours.
Here, “curl plus” means a curl where the hard coat layer coating side of the film is inside the curve, and “minus” means a curl where the coating side is outside the curve.
In the hard coat film of the present invention, the absolute value of the difference between the curl values when only the relative humidity is changed to 80% and 10% based on the curl measurement method described above is preferably 24 to 0, 15 ~ 0 is more preferable, and 8-0 is most preferable. This is a characteristic related to handling suitability, peeling resistance and crack resistance when films are attached under various humidity.

  The crack resistance of the hard coat film in the present invention is preferably 50 mm or less, more preferably 40 mm or less, and more preferably 30 mm or less. Is most preferred. About the crack of an edge part, it is preferable that there is no crack or the length of a crack is less than 1 mm on average. This crack resistance is an important characteristic for preventing crack defects in handling such as coating, processing, cutting and sticking of a hard coat film.

  The active energy ray curable coating liquid (curing composition coating liquid) is prepared by dissolving the polyfunctional monomer and the polymerization initiator mainly in an organic solvent such as ketone, alcohol, or ester. Furthermore, it can be prepared by adding a surface-modified hard inorganic fine particle dispersion and a soft fine particle dispersion.

In the present invention, the hard coat layer is produced by dipping, spinner, spray, roll coater, gravure, wire bar method, slot extremity on the support (that is, transparent resin material layer) an active energy ray curable coating solution. It can be produced by applying and drying by a known thin film forming method such as a rouge coater method (single layer, multi-layer), slide coater method, etc. and then irradiating with active energy rays to cure.
Drying is preferably performed under conditions where the organic solvent concentration in the applied liquid film is 5% by mass or less after drying, more preferably 2% by mass or less, and even more preferably 1% by mass or less. The drying conditions are affected by the thermal strength of the support, the conveying speed, the length of the drying process, etc., but the lower the content of the organic solvent as possible is preferable from the viewpoint of increasing the polymerization rate.

Furthermore, for the purpose of improving the adhesion between the support and the hard coat layer, a surface treatment is applied to one side or both sides of the support (that is, the transparent resin material layer) by an oxidation method or a concavo-convex method (so-called embossing), if desired. Can be applied. Examples of the oxidation method include corona discharge treatment, glow discharge treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone / ultraviolet irradiation treatment, and the like.
Furthermore, one or more undercoat layers can be provided. Examples of the material for the undercoat layer include copolymers such as vinyl chloride, vinylidene chloride, butadiene, (meth) acrylic acid ester, and vinyl ester, or water-soluble polymers such as latex, low molecular weight polyester, and gelatin. Further, the undercoat layer may contain tin oxide, a metal oxide such as tin oxide / antimony oxide composite oxide, tin oxide / indium oxide composite oxide, or an antistatic agent such as a quaternary ammonium salt.

  The hard coat layer can have a multi-layer structure, and can be produced by appropriately laminating in order of hardness.

<3. Film with adhesive>
One mode of the hard coat film of the present invention is preferably used as a film with a pressure-sensitive adhesive in a mode in which a pressure-sensitive adhesive is coated on at least one surface and a pressure-sensitive adhesive layer is provided.
In general, the pressure-sensitive adhesive layer is easily deformed by the pressure from the upper part of the film, but when used in combination with the hard coat layer according to the present invention, a film with a pressure-sensitive adhesive that is not easily deformed can be obtained.

  Further, the hard coat film of the present invention, particularly a film with an adhesive, is used as a light-transmitting layer (also referred to as a light-transmitting film) that covers the surface through which light for reading and writing of the recording layer of the optical recording material is transmitted. By using it, an optical recording medium having excellent recording characteristics can be provided.

  In the step of installing the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer can be continuously provided on a surface different from the hard coat layer application surface of the translucent film in which the hard coat layer is formed on one surface in advance. As a method of providing the pressure-sensitive adhesive layer, a method of attaching a pre-formed pressure-sensitive adhesive layer (hereinafter, referred to as an indirect method as appropriate), a pressure-sensitive adhesive is directly applied to the surface of the translucent film, and dried. Thus, it can be roughly divided into two methods: a method for forming a pressure-sensitive adhesive layer (hereinafter, referred to as a direct method as appropriate).

  In the case of the indirect method, the “method of attaching a pre-formed pressure-sensitive adhesive layer” means, for example, that a pressure-sensitive adhesive is continuously applied to the surface of a release film having the same size as the light-transmitting film and dried. Thus, a method is shown in which a pressure-sensitive adhesive layer is provided over the entire area of one surface of the release film, and the pressure-sensitive adhesive layer is attached to the translucent film. As a result, a pressure-sensitive adhesive layer with a release film is provided over the other surface of the translucent film.

  In the direct method, the front end of the translucent film wound in a roll shape is sent to a predetermined application region, and the adhesive is continuously applied from the front end to the end of one side of the translucent film, In this method, after the coating film is formed, the coating film is sequentially dried, and the pressure-sensitive adhesive layer is provided over the entire other surface of the translucent film.

In the indirect method and the direct method described above, conventionally known coating means can be used as the pressure-sensitive adhesive coating means. Specific examples include a spray method, a roll coating method, a blade coating method, a doctor roll method, and a screen printing method.
Moreover, as a drying means, conventionally well-known means, such as heat drying and ventilation drying, can be used.

  As the pressure-sensitive adhesive, acrylic-based, rubber-based, or silicon-based pressure-sensitive adhesives can be used, but acrylic-based pressure-sensitive adhesives are preferable from the viewpoints of transparency and durability. As such an acrylic pressure-sensitive adhesive, 2-ethylhexyl acrylate, n-butyl acrylate and the like are the main components, and in order to improve cohesion, short-chain alkyl acrylates and methacrylates such as methyl acrylate, ethyl acrylate, and methyl methacrylate are used. And acrylic acid, methacrylic acid, acrylamide derivatives, maleic acid, hydroxylethyl acrylate, glycidyl acrylate, and the like, which can be crosslinking points with the crosslinking agent, are preferably used. The glass transition temperature (Tg) and the crosslinking density can be changed by appropriately adjusting the mixing ratio and type of the main component, the short chain component, and the component for adding a crosslinking point.

  Examples of the crosslinking agent used in combination with the pressure-sensitive adhesive include an isocyanate crosslinking agent, an epoxy resin crosslinking agent, a melamine resin crosslinking agent, a urea resin crosslinking agent, and a chelate crosslinking agent. Among these, an isocyanate crosslinking agent is used. An agent is more preferable. Examples of the isocyanate-based crosslinking agent include tolylene diisocyanate, 4-4′-diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, naphthylene-1,5-diisocyanate, o-toluidine isocyanate, isophorone diisocyanate, triphenylmethane triisocyanate, and the like. Isocyanates, products of these isocyanates and polyols, and polyisocyanates formed by condensation of isocyanates can be used. Commercially available products of these isocyanates include Nippon Polyurethane, Coronate L, Coronate HL, Coronate 2030, Coronate 2031, Millionate MR, Millionate HTL; Takenate D-102, Takenate D-110N from Takeda , Takenate D-200, Takenate D-202; manufactured by Sumitomo Bayer, Death Module L, Death Module IL, Death Module N, Death Module HL;

The pressure-sensitive adhesive layer is formed on the surface of the translucent film other than the hard coat layer, but it is wound up in a roll shape in the subsequent process, and the hard coat layer and the pressure-sensitive adhesive layer are in close contact with each other. In order to prevent this, it is preferable that a release film is attached to the surface of the pressure-sensitive adhesive layer. As described above, in the indirect method, a release film can be attached in advance. On the other hand, in the case of the direct method, it is preferable to newly add a step of attaching a release film to the surface of the pressure-sensitive adhesive layer after the pressure-sensitive adhesive layer is formed on the surface of the translucent film.
Here, as a release film affixed on the surface of an adhesive layer, a polyethylene film, a polyethylene terephthalate film, a polyethylene naphthalate film, a polycarbonate film, a triacetate cellulose film etc. are mentioned.

<4. Information record carrier>
The information record carrier of the present invention is an information record carrier capable of reproducing an information signal by optical means. The basic structure of the information recording carrier of the present invention includes a support (substrate), a recording layer formed on the support and capable of recording information signals, a light-transmitting layer formed on the recording layer and transmitting light. Consists of. Each component may be interchanged or combined with each other as long as the content of the invention is not impaired. Each of them needs to exist at least one, but each of them may exist in a plurality of layers, or one layer may be composed of a plurality of layers having different compositions and characteristics. Specifically, two recording layers and a light-transmitting layer are provided on one side of the support (substrate) such as support (substrate) / recording layer / light-transmitting layer / recording layer / light-transmitting layer. A recording layer and a light-transmitting layer may be disposed on both sides of the support, such as layer / recording layer / support (substrate) / recording layer / light-transmitting layer. In addition to the above configuration, a known antistatic layer, lubricating layer, protective layer, reflective layer, and the like may be provided. Further, label printing may be performed on the side of the support (substrate) opposite to the recording layer.
The information record carrier of the present invention may be one mounted in the cartridge. In addition, the size is not limited, and in the case of a disc-shaped information record carrier, for example, various sizes with a diameter of 30 to 300 mm can be taken, and the diameters 32, 51, 65, 80, 88, 120, 130, and 200 can be taken. , 300 mm, etc.

In the information recording carrier of the present invention, the support (substrate) is a base (substrate) having a function of mechanically holding a recording layer, a light transmitting layer, and the like, which will be described later.
The constituent material may be any of synthetic resin, ceramic, metal and the like. Typical examples of synthetic resins include polycarbonate, polymethyl methacrylate, polystyrene, polycarbonate-polystyrene copolymer, polyvinyl chloride, alicyclic polyolefin, polymethylpentene, and other thermoplastic resins, thermosetting resins, and various radiation curable resins ( UV curable resins and visible light curable resins are included). In addition, these may be a synthetic resin blended with metal powder or ceramic powder. As typical examples of ceramic, soda lime glass, soda aluminosilicate glass, borosilicate glass, quartz glass, and the like can be used. Aluminum, copper, iron or the like can be used as the metal.
Among these, polycarbonate and amorphous polyolefin are preferable from the viewpoint of moisture resistance, dimensional stability, and price, and polycarbonate is most preferable.
The thickness of the support is preferably 0.3 to 3 mm, more preferably 0.6 to 2 mm, and most preferably within the range of 1.1 mm ± 0.3 mm from the need to mechanically hold the other layers. Used for.

On the surface of the support, irregularities (pregrooves) representing information such as tracking grooves or address signals are usually formed. The pregroove is preferably formed directly on the support when a resin material such as polycarbonate is injection molded or extruded.
Further, the pregroove may be formed by providing a pregroove layer. As a material of the pregroove layer, a mixture of at least one monomer (or oligomer) of acrylic acid monoester, diester, triester, tetraester, pentaester and hexaester of polyol and a photopolymerization initiator is used. be able to. For example, the pregroove layer is formed by, first, applying a mixed liquid composed of the above-described acrylic ester and polymerization initiator on a precisely formed master (stamper), and further, supporting the support on the coating liquid layer. After mounting, the coating layer is cured by irradiating ultraviolet rays through the support or the matrix, and the support and the coating layer are fixed. Subsequently, it can obtain by peeling a support body from a mother mold. The thickness of the pregroove layer is generally in the range of 0.01 to 100 μm, preferably in the range of 0.05 to 50 μm.

In the present invention, the track pitch of the pregroove of the support is preferably in the range of 200 to 400 nm, more preferably in the range of 250 to 350 nm, depending on the disc format.
The groove depth of the pregroove is preferably in the range of 10 to 150 nm, more preferably in the range of 20 to 100 nm, and still more preferably in the range of 30 to 80 nm. Moreover, it is preferable that the half value width exists in the range of 50-250 nm, and it is more preferable that it is the range of 100-200 nm.

When the light reflecting layer described later is provided on the information recording carrier of the present invention, an undercoat layer is formed on the surface of the support on the side where the light reflecting layer is provided for the purpose of improving flatness and adhesion. It is preferable.
Examples of the material for the undercoat layer include polymethyl methacrylate, acrylic acid / methacrylic acid copolymer, styrene / maleic anhydride copolymer, polyvinyl alcohol, N-methylol acrylamide, styrene / vinyl toluene copolymer, chlorosulfone. Polymer materials such as chlorinated polyethylene, nitrocellulose, polyvinyl chloride, chlorinated polyolefin, polyester, polyimide, vinyl acetate-vinyl chloride copolymer, ethylene-vinyl acetate copolymer, polyethylene, polypropylene, polycarbonate; silane coupling agents And the like.

  The undercoat layer is prepared by dissolving or dispersing the above materials in an appropriate solvent to prepare a coating solution, and then applying this coating solution to the surface of the support by a coating method such as spin coating, dip coating, or extrusion coating. Can be formed. In general, the thickness of the undercoat layer is preferably in the range of 0.005 to 20 μm, more preferably in the range of 0.01 to 10 μm.

  The light reflecting layer can be optionally provided between the support and the recording layer for the purpose of improving the reflectance during information reproduction. The light reflecting layer can be formed on the support by depositing, sputtering, or ion plating a light reflecting material having a high reflectance to the laser beam. The thickness of the light reflecting layer is generally in the range of 10 to 300 nm, and preferably in the range of 50 to 200 nm. Note that the reflectance of the light reflective material is preferably 70% or more.

  As a light reflective material having a high reflectance, Mg, Se, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Co, Ni, Ru, Rh, Pd , Ir, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Si, Ge, Te, Pb, Po, Sn, Bi, and other metals, metalloids, and stainless steel. These light reflecting substances may be used alone, in combination of two or more kinds, or may be used as an alloy. Among these, Cr, Ni, Pt, Cu, Ag, Au, Al, and stainless steel are preferable. Particularly preferred is Au, Ag, Al or an alloy thereof, and most preferred is Au, Ag or an alloy thereof.

  In the information recording carrier of the present invention, the recording layer is a layer having a function capable of recording or rewriting information by recording an information signal on the layer by optical or magnetic recording means, and optically. An information signal can be reproduced from the layer by a simple reproducing means (laser light or the like). The recording layer uses a high-reflectance material when the information record carrier is a reproduction-only information record carrier, and in the case of a recording / reproduction type information record carrier, the recording layer is a dye recording material or phase according to the recording or reproduction principle. A change recording material or a magneto-optical recording material is selected and used. The thickness of the recording layer is preferably 2 to 300 nm, and particularly preferably 5 to 200 nm.

Gold, silver, or the like is used as the high light reflectivity material used for the recording layer of the read-only regular record carrier.
Specific examples of recording materials for dye recording include cyanine dyes, phthalocyanine dyes, naphthalocyanine dyes, azo dyes, naphthoquinone dyes, fulgide dyes, polymethine dyes, acridine dyes, and the like.
Recording materials for phase change recording include alloys such as indium, antimony, tellurium, selenium, germanium, bismuth, vanadium, gallium, platinum, gold, silver, copper, tin, arsenic (alloys are oxides, nitrides, Carbides, sulfides, fluorides, etc.) can be used, and it is particularly preferable to use GeSbTe, AgInSbTe, CuAlTeSb, or the like. A recording layer may be formed using a laminated film of an indium alloy and a tellurium alloy.

  Recording materials for magneto-optical recording include alloys such as terbium, cobalt, iron, gadolinium, chromium, neodymium, dysprosium, bismuth, palladium, samarium, holmium, prosodymium, manganese, titanium, palladium, erbium, ytterbium, lutetium, tin, etc. (Alloys include oxides, nitrides, carbides, sulfides, and fluorides), and are composed of transition metal and rare earth alloys, as represented by TbFeCo, GdFeCo, DyFeCo, and the like. Is preferred. Furthermore, a recording layer may be formed by using an alternating laminated film of cobalt and platinum.

  These recording layers have auxiliary films such as silicon, tantalum, zinc, magnesium, calcium, aluminum, chromium, zirconium and the like (oxides) for the purpose of improving reproduction output, rewriting frequency, and storage stability. , Nitrides and carbides) and highly reflective films (aluminum, gold, silver, etc.) may be used in combination.

  The recording layer using the recording material for dye recording preferably contains a dye having maximum absorption in the wavelength region of the laser beam used for reproduction, and in particular, recording and reproduction can be performed with a laser having a wavelength of 500 nm or less. As such, it is more preferable to contain a dye having a maximum absorption in the wavelength region. Examples of the dye used include cyanine dyes, oxonol dyes, metal complex dyes, azo dyes, and phthalocyanine dyes. Specifically, JP-A-4-74690, JP-A-8-127174, JP-A-11-53758, JP-A-11-334204, JP-A-11-334205, JP-A-11-334206. , JP-A-11-334207, JP-A-2000-43423, JP-A-2000-108513, JP-A-2000-158818, or triazole, triazine, Examples of the pigment include cyanine, merocyanine, aminobutadiene, phthalocyanine, cinnamic acid, viologen, azo, oxonol benzoxazole, and benzotriazole, and pigments such as cyanine, aminobutadiene, benzotriazole, and phthalocyanine are preferable.

When a recording material for dye recording is used for the recording layer, a coating solution is prepared by dissolving the above-described dye and, if desired, a binder in an appropriate solvent, and then this coating solution is used to prepare a coating material for the aforementioned support. It can form by apply | coating to a groove surface or the light reflection layer surface, forming a coating film, and then drying. Furthermore, various additives such as an antioxidant, a UV absorber, a plasticizer, and a lubricant may be added to the coating solution depending on the purpose.
In addition, as a method for dissolving the dye and the binder, methods such as ultrasonic treatment, homogenizer treatment, disper treatment, sand mill treatment, stirrer stirring treatment, and the like can be applied.

  Examples of the solvent for the coating solution include esters such as butyl acetate and cellosolve acetate; ketones such as methyl ethyl ketone, cyclohexanone and methyl isobutyl ketone; chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane and chloroform; amides such as dimethylformamide Hydrocarbons such as cyclohexane; ethers such as tetrahydrofuran, ethyl ether and dioxane; alcohols such as ethanol, n-propanol, isopropanol, n-butanol and diacetone alcohol; fluorine such as 2,2,3,3-tetrafluoropropanol; Solvents: Glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, etc. Door can be. The above solvents may be used alone in consideration of the solubility of the dye and binder to be used, or two or more kinds may be used in combination as appropriate.

  Examples of binders include, for example, natural organic polymer materials such as gelatin, cellulose derivatives, dextran, rosin, rubber; and hydrocarbon resins such as polyurethane, polyethylene, polypropylene, polystyrene, polyisobutylene, polyvinyl chloride, poly Vinyl resins such as vinylidene chloride, polyvinyl chloride / polyvinyl acetate copolymers, acrylic resins such as polymethyl acrylate and polymethyl methacrylate, polyvinyl alcohol, chlorinated polyethylene, epoxy resins, butyral resins, rubber derivatives, phenols A synthetic organic polymer such as an initial condensate of a thermosetting resin such as formaldehyde resin can be mentioned. When a binder is used in combination as the recording layer material, the amount of binder used is preferably in the range of 0.01 to 50 times (mass ratio) to the dye, and 0.1 to 5 times the amount. More preferably, it is the range. It is possible to improve the storage stability of the recording layer by incorporating a binder into the recording layer.

  Thus, the density | concentration of the pigment | dye in the coating liquid prepared is in the range of 0.01-10 mass% generally, Preferably it exists in the range of 0.1-5 mass%.

Examples of the coating method include a spray method, a spin coating method, a dip method, a roll coating method, a blade coating method, a doctor roll method, and a screen printing method.
The application temperature is not particularly limited as long as it is 23 to 50 ° C, but is preferably 24 to 40 ° C, and more preferably 25 to 37 ° C.

  The recording layer may be a single layer or a multilayer. The thickness of the recording layer is generally in the range of 20 to 500 nm, preferably in the range of 50 to 300 nm.

The recording layer can contain various anti-fading agents in order to improve the light resistance of the recording layer.
As the antifading agent, a singlet oxygen quencher is generally used. As the singlet oxygen quencher, those described in publications such as known patent specifications can be used. Specific examples thereof include JP-A Nos. 58-175893, 59-81194, 60-18387, 60-19586, 60-19587, and 60-35054. 60-36190, 60-36191, 60-44554, 60-44555, 60-44389, 60-44390, 60-54892, JP-A-60-47069, JP-A-63-209995, JP-A-4-25492, JP-B-1-38680, JP-A-6-26028, etc., German Patent No. 350399, and Japan Examples include those described in Chemical Society Journal, October 1992, page 1141.
The content of the anti-fading agent such as a singlet oxygen quencher is usually in the range of 0.1 to 50% by mass, preferably in the range of 0.5 to 45% by mass, based on the total solid content of the recording layer. More preferably, it is the range of 3-40 mass%, Most preferably, it is the range of 5-25 mass%.

An intermediate layer (barrier layer) may be formed on the surface of the recording layer in order to improve the adhesion to the light-transmitting layer and the storage stability of the dye. The barrier layer is a layer made of a material such as an oxide, a nitride, a carbide, or a sulfide made of any one or more of Zn, Si, Ti, Te, Sm, Mo, Ge, and the like. The barrier layer may be hybridized like ZnS—SiO ₂ . The barrier layer can be formed by sputtering, vapor deposition ion plating, or the like, and the thickness is preferably 1 to 100 nm.

In the information record carrier of the present invention, the translucent layer has a function of physically guiding the converged reproduction light to the recording layer, and at the same time, a function of chemically and mechanically protecting the recording layer. The translucent layer of the present invention is preferably made of a film that is thinner than the thickness of the support.
In the present invention, “translucent” is practically transparent (transmittance of 70% or more, desirably) with respect to the wavelength of light (for example, light of 600 to 800 nm or 350 to 450 nm) of optical means used for recording and reproduction. Means 80% or more).

  The light-transmitting layer used in the present invention is preferably bonded to a substrate including a support or a recording layer via an adhesive layer.

  The thickness of the light transmitting layer of the information recording carrier according to the present invention is preferably thinner than the thickness of the support. Considering the aberration that increases when the information record carrier is tilted, the thickness is suitably 50 to 300 μm, preferably 60 to 200 μm, more preferably 70 to 120 μm. Further, the variation in thickness in a single layer is ± 3 μm at maximum, preferably ± 2 μm or less. More desirably, it should be ± 1 μm or less.

  The optical information record carrier of the present invention records and reproduces information as follows, for example. First, a blue-violet laser (for example, wavelength) is transmitted from the light transmitting layer side through the objective lens while rotating the optical information record carrier at a predetermined linear velocity (0.5 to 10 m / sec) or a predetermined constant angular velocity. 405 nm) or the like. By this irradiation light, the recording layer absorbs the light and the temperature rises locally. For example, information is recorded by generating pits and changing their optical characteristics. The reproduction of the information recorded as described above is performed by using a blue-violet laser as an optical means while rotating the optical information record carrier at a predetermined constant linear velocity, for example, by irradiating a laser beam from the translucent layer side. , By detecting the reflected light.

As a laser light source having an oscillation wavelength of 500 nm or less that serves as an optical means for recording and reproduction, for example, a blue-violet semiconductor laser having an oscillation wavelength in the range of 390 to 415 nm, a blue-violet SHG laser having a central oscillation wavelength of 425 nm, etc. Can be mentioned.
In order to increase the recording density, the NA of the objective lens used for the pickup is preferably 0.7 or more, and more preferably 0.85 or more.

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to the following examples.
1. Production of Hard Coat Film A hard coat film (a film in which a translucent layer and a hard coat layer are further provided on a recording layer of an optical recording medium) is composed of a translucent layer and a hard coat layer in this order from the support (substrate) side. Here, an example of manufacturing a light-transmitting layer composed of a light-transmitting layer and a hard coat layer is shown.
(1) Production of translucent film Kneading into polymer resin and film formation 7.0 g of polycarbonate (Idemitsu MD1500) was melted at 250 ° C using a MiniLab type kneader manufactured by Haake. After melting for 5 minutes, 70 mg of strontium carbonate microcrystals and 7 mg of stearic acid (special grade manufactured by Wako Pure Chemical Industries, Ltd.) were added, and kneaded for 30 minutes while maintaining 250 ° C. at a kneader rotation speed of 50 rpm. The kneaded sample was molded into a tablet at 250 ° C. using a Haake injection molding machine. The tablet-like sample was pressed for 3 minutes at 200 ° C. and a pressure of 30 MPa using a mini TEST PRESS-10 type hot press manufactured by Toyo Seiki to produce a film sample having a thickness of 80 μm.
In addition, a film sample in which strontium carbonate was changed to calcium carbonate and polycarbonate was changed to polyethylene terephthalate was also prepared for this film.
Note that strontium carbonate has an aspect ratio of 40 and a cross-sectional circle equivalent diameter of 10 nm, and calcium carbonate has an aspect ratio of 60 and a cross-sectional circle equivalent diameter of 8 nm.
Measurement of Stretching and Birefringence Films prepared by the above method and polycarbonate films not containing strontium carbonate microcrystals for comparison were subjected to heat stretching at 200 ° C. using RTC-1210A type Tensilon manufactured by Orientec. . When the ratio between the length after stretching and the length before stretching was defined as the stretching ratio, samples having a stretching ratio of 1.0 (no stretching) and 1.5 were prepared, and birefringence was measured. The birefringence measurement was performed at 25 ° C. and 60% RH using an automatic birefringence measuring machine ABR-10A manufactured by UNIOPT. The obtained birefringence data is shown in Table 4.

  In the samples of the present invention containing alkaline earth metal carbonate crystals (C, E, G vs. D, F, H), the birefringence increases very little even when stretched, and the comparative example A remarkable birefringence inhibitory action was observed for the sample (A vs. B).

(2). Formation of hard coat layer (2) -1. Preparation of hard coat layer coating solution (2) -1-1. Preparation of solution H1 Glycidyl methacrylate was dissolved in methyl ethyl ketone (MEK) and reacted at 80 ° C. for 2 hours while dropwise adding a thermal polymerization initiator (V-65 (manufactured by Wako Pure Chemical Industries, Ltd.)). The solution was added dropwise to hexane, and the precipitate was dried under reduced pressure. Polyglycidyl methacrylate (polystyrene equivalent molecular weight: 12,000) dissolved in methyl ethyl ketone so as to have a concentration of 50% by mass was added to trimethylolpropane. 150 parts by mass of triacrylate (Biscoat # 295; manufactured by Osaka Organic Chemical Industry Co., Ltd.), 6 parts by mass of photo radical polymerization initiator (Irgacure 184, manufactured by Ciba Geigy) and photo cationic polymerization initiator (Rhodsil 2074, manufactured by Rhodia) 6 parts by mass and anti-fouling agent Mega-Faque 531A (Dainippon Ink Chemical Co., Ltd.) 10 parts by weight were mixed with stirring which was dissolved in methyl isobutyl ketone 30 parts by weight, the hard coat layer coating solution (H1) was prepared.

(2) -1-2. Preparation of H2 liquid 93 parts by mass of dipentaerythritol hexaacrylate (DPHA, manufactured by Daicel UCB), 5 parts by mass of R-3833 (manufactured by Daikin Fine Chemical Laboratory), UMS-182 (manufactured by Gelest) as an antifouling agent ) 2 parts by mass, 3 parts by mass of a photo radical polymerization initiator (Irgacure 907, manufactured by Ciba Geigy) were dissolved and mixed in a methyl ethyl ketone / methyl isobutyl ketone (1: 1 mass ratio) mixed solution, and the hard coat layer coating solution (H2) was added. It was adjusted.

(2) -1-3. Preparation of H3 to H7 liquids Hard coat layer coating liquids H3 to H7 were prepared by changing the amount of MEK-ST (containing 30% by weight of silica particle solids) manufactured by Nissan Chemical as shown in Table 4 with respect to H2.

(2) -2. Production of hard coat film (application of hard coat layer)
Latex (LX407C5, manufactured by Nippon Zeon Co., Ltd.) made of styrene-butadiene copolymer having a refractive index of 1.55 and a glass transition temperature of 37 ° C. and a tin oxide / antimony oxide composite oxide ( FS-10D (manufactured by Ishihara Sangyo Co., Ltd.) mixed at a ratio of 5: 5 by weight was applied so that the film thickness after drying was 200 nm to form an undercoat layer with an antistatic layer, The hard coat layer coating solution is applied by an extrusion method so as to have the thickness shown in Table 4, dried, and then irradiated with ultraviolet rays (700 mJ / cm ² ) in an atmosphere with an oxygen concentration of 0.03%. A film was prepared and wound into a roll.

2. Preparation and test of optical information record carrier Production of support and recording layer Injection molded polycarbonate resin (polycarbonate manufactured by Teijin Limited, trade name: bread) having spiral grooves (depth 100 nm, width 120 nm, track pitch 320 nm), thickness 1.1 mm, diameter 120 mm Light AD5503) On the surface having the groove of the substrate, Ag was sputtered to form a light reflecting layer having a thickness of 100 nm.

Thereafter, 20 g of Orazol Bull GN (Recording material 1, phthalocyanine dye, manufactured by CIBA Specialty Chemical) was added to 1 liter of 2,2,3,3-tetrafluoropropanol and subjected to ultrasonic treatment for 2 hours. It melt | dissolved and the coating liquid for recording layer formation was prepared. The prepared coating solution was applied onto the substrate by a spin coating method at 23 ° C. and 50% RH while changing the number of rotations from 300 to 4000 rpm on the light reflecting layer. Thereafter, the recording layer formed by storing at 23 ° C. and 50% RH for 1 to 4 hours had a thickness of 100 nm. Then, on the recording layer, ZnS—SiO ₂ was sputtered so as to be a mixed crystal layer having a thickness of 5 nm to form an intermediate layer (barrier layer).
In addition, as another example of the recording material, DC and RF sputtering methods are used instead of Orasur Bull GN, and the phase change recording layer is Ag · Pd · Cu (98: 1: 1) / ZnS · SiO (80:20) / A laminated film made of Ag · In · Sb · Te (4: 5: 61: 30) / ZnS · SiO (80:20) (recording material 2) was also formed under the following conditions.
(1) Ag · Pd · Cu; DC 5 kw / Ar pressure 2 mTorr / film pressure 100 nm
(2) ZnS · SiO; RF 4 kw / Ar pressure 2 mTorr / film pressure 190 nm
(3) Ag · In · Sb · Te; DC 0.4 kw / Ar pressure 2 mTorr / film pressure 15 nm
(4) ZnS · SiO; RF 4 kw / Ar pressure 2 mTorr / film pressure 100 nm

B. Lamination of Hard Coat Film and Substrate Light is obtained by laminating the hard coat film prepared in Example 1 on the recording layer provided on the substrate in A as described above via an intermediate layer. An information record carrier was prepared.
B-1. Formation of pressure-sensitive adhesive layer Acrylic copolymer (solvent: ethyl acetate / toluene = 1/1) and isocyanate-based crosslinking agent (solvent: ethyl acetate / toluene = 1/1) 100: 1 (mass ratio) To prepare an adhesive coating solution A. Using this adhesive coating liquid A, an adhesive layer was provided on the surface of the release film by an indirect method.
While conveying the polyethylene release film wound in a roll shape, the pressure-sensitive adhesive coating solution A was applied to the surface of the release film so that the thickness after drying was 20 μm. Then, it was made to dry at 100 degreeC in a drying area | region, and the release film provided with the adhesive layer was obtained.

B-2. Production of Transparent Sheet for Optical Information Record Carrier A release film provided with an adhesive layer was bonded to the reverse side of the hard coat film provided with a hard coat layer so that the adhesive layer was in contact. Thereafter, the hard coat film provided with the hard coat layer and the pressure-sensitive adhesive layer was again wound into a roll, and in that state, the hard coat film was held in an atmosphere of 23 ° C. and 50% RH for 72 hours.
Then, the hard coat film provided with the hard coat layer and the pressure-sensitive adhesive layer was sent out and punched into the same shape as the substrate. Thus, a transparent sheet for an optical information recording carrier having an adhesive layer on one side of the translucent film and a hard coat layer on the other side was obtained.

B-3. Production of optical information record carrier (bonding of hard coat film to support, recording layer) Release the release film on the adhesive side from the disc-shaped transparent sheet for optical information record carrier, and then intermediate layer and adhesive layer And an optical information recording carrier.

C. Evaluation method C-1. Pencil hardness test After the film of the translucent layer of the record carrier was conditioned for 2 hours under the conditions of a temperature of 25 ° C. and a relative humidity of 60%, using a test pencil specified by JIS-S-6006, JIS-K-5400 According to the pencil hardness evaluation method prescribed by No. 1, the hardness of a pencil with no scratches observed under a load of 9.8 N was determined.

C-2. Measurement of recording characteristics These information record carriers are mounted on a recording / reproducing apparatus having a pickup composed of a blue-violet laser emitting at λ = 405 nm and an objective lens having a numerical aperture NA of 0.7. Recording and reproduction of a D8-15 modulated signal set to 0.24 μm was performed, and signal reproduction jitter was measured. The smaller the jitter is, the more preferable, specifically, 5% or less.

Table 5 shows the hard coat film prepared in Example 1 above, the optical recording medium prepared in Example 2, and various measurement results. Here, the jitter after the scratch is the jitter after the surface of the optical recording medium is rubbed 100 times by applying a pressure of 100 g / cm ² with steel wool, and the jitter after storage is 70 ° C. and 80% after storage for 3 days. It shows the measured jitter.

Table 5 shows the following.
(1) Film sample No. By using 9-18, 21-27, comparative sample No. It is possible to produce an optical recording medium having a pencil hardness higher than 1 to 8, a low jitter value, and a jitter of 7% or less even after a scratch test and a storage test.
(2) However, test No. using polyethylene terephthalate as a resin material. In Nos. 24 and 25, test Nos. Using polycarbonate were used. Compared with 21 and 13, the jitter after storage was greatly deteriorated, and it was found that polycarbonate is preferable among the resin materials applied to the present invention.
(3) Test No. In the case where no hard coat layer was applied as in Nos. 1 to 8 (Comparative Example), even if Test No. 7 and 8, even when the polyethylene terephthalate is used and the pencil hardness is 2B, the increase in jitter after scratching is large, and it can be seen that it cannot withstand actual use.
(4) Test No. It can be seen that when a film not mixed with the carbonate of the present invention is used as in 19 and 20 (Comparative Example), jitter from the initial stage is high, which is not preferable.
(5) Test No. When a calcium carbonate salt is used as in No. 23, test no. Although the jitter is slightly higher than 13 and the recording characteristics are poor, the effect of the invention still appears.
(6) Even if a hard coat layer was applied, test no. 17 and 18, the amount of filler is too large, When the film thickness is excessively increased as in 19 and 20, the recording characteristics after storage are deteriorated. In addition, Test No. If the amount of filler is small as in 9, 10, the recording characteristics after scratching deteriorate.

1 is a schematic configuration diagram of a typical information recording medium incorporating a hard coat layer of the present invention.

Claims (10)

  A hard coat film obtained by applying at least one hard coat layer on a resin material containing an alkaline earth metal carbonate crystal having an aspect ratio of 1.5 or more.   2. The hard coat film according to claim 1, wherein the carbonate crystal contained in the resin material has a cross-sectional equivalent circle diameter of 1 to 50 nm.   The hard coat film according to claim 1, wherein the resin material is polyester or polycarbonate.   The hard coat layer comprises at least a polyfunctional acrylic acid monomer and a powdery inorganic filler, and contains 5 to 60% by weight of the inorganic filler. Hard coat film according to crab.   The hard coat film according to any one of claims 1 to 4, wherein an adhesive is applied to at least one surface to form a film with an adhesive.   An information recording carrier capable of recording and / or reproducing information signals by optical means, comprising a support, a recording layer capable of recording an information signal formed on the support, and formed on the recording layer And a light-transmitting layer that transmits the light, and the light-transmitting layer is made of a resin material containing an alkaline earth metal carbonate crystal having an aspect ratio of 1.5 or more. Information record carrier.   7. The information recording carrier according to claim 6, wherein the resin material containing carbonate crystals is polyester or polycarbonate.   The at least one hard coat layer is apply | coated to the resin material surface in which the said translucent layer contains the carbonate crystal of the alkaline-earth metal whose aspect ratio is 1.5 or more, It is characterized by the above-mentioned. An information record carrier according to 1.   9. The information recording carrier according to claim 7, wherein the hard coat layer comprises at least a polyfunctional acrylic acid monomer and a powdery inorganic filler, and the inorganic filler is contained in an amount of 5 to 60% by weight.   The adhesive-coated film obtained by coating the hard coat film with an adhesive is obtained by bonding to a substrate on which a recording layer capable of recording an information signal is provided on a support. The information record carrier according to any one of 7 to 9.

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