JP2011246517A - Active energy ray-curable resin composition, concavo-convex shaped article, and optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active energy ray-curable resin composition capable of obtaining a cured product that has good mold releasability from a mold made from polycarbonate and has a little warpage of a substrate due to cure shrinkage.SOLUTION: The active energy ray-curable resin composition includes (A) 5-35 pts.mass of a urethane (meth)acrylate oligomer having a polybutadiene skeleton, a polyisoprene skeleton, a hydrogenated polybutadiene skeleton, and a hydrogenated polyisoprene skeleton, (B) 65-95 pts.mass of a (meth)acryloyl group-containing compound having a molecular weight of 1,000 or less and a negative result in the following test, and (C) 0-5 pts.mass of a compound having a positive result in the following test. An article and an optical recording medium use the active energy ray-curable resin composition. Polycarbonate resin solubility test: liquid under test 0.3 ml is dropped on a polycarbonate plate with 3 mm thickness and is left still at 20°C for 10 minutes. The result is rated as "positive" when increase in a haze value after wiping exceeds 10.0 while the result is rated as "negative" when the increase in a haze value is 10.0 or less.

Description

  The present invention relates to an active energy ray-curable resin composition capable of obtaining a cured product having good release properties from a polycarbonate mold and having a small curing shrinkage.

  The active energy ray-curable resin composition is cured in a short time by irradiating active energy rays such as ultraviolet rays and electron beams, and the cured product has toughness, flexibility, scratch resistance, weather resistance, and chemical resistance. Etc. can be provided with excellent properties. Therefore, the active energy ray curable resin composition can be used for wood coating materials, PVC floor coating materials, plastic molding products, plastic molding coating materials, plastic films, optical fiber coating materials, optical recording medium coating materials, casting, etc. Used in many industrial applications.

  Particularly in the field of optical recording media, various uses such as a protective coating material on the recording surface, a hard coating material for preventing scratches on the reading surface, an adhesive for a digital versatile disc (hereinafter referred to as “DVD”), a printing ink on the label surface, etc. Many active energy ray-curable resin compositions are used for this purpose.

  In recent years, an optical recording medium of a type having a base, a recording film, and a transparent cover layer and reading or writing information with a blue laser from the transparent cover layer side has been developed as a large-capacity optical recording medium exceeding DVD. Further, as a high-density optical recording medium, an optical recording medium of a type in which recording layers are multilayered has been developed.

  Such a multilayer optical recording medium requires a transparent intermediate layer that separates the translucent recording layer from other recording layers with a certain thickness. As a method for producing this intermediate layer, for example, an active energy ray-curable resin composition is desired between a transparent mold having a minute groove or pit corresponding to a signal and the recording layer side of the substrate with a recording layer. Examples include a method obtained by injecting and curing to a constant film thickness, then releasing from the transparent mold, and forming a recording layer on the surface of the obtained cured product (intermediate layer) (Patent Document 1 and Patent Document 2).

  Moreover, the curable composition excellent in the mold release property developed in order to form the fine unevenness | corrugation corresponding to the signal which should record information is also known (patent document 3, patent document 4, and patent document 5). .

  However, since the composition described in Patent Document 3 is composed only of bis (2-acryloyloxyethyl) hydroxyethyl isocyanurate, trimethylolpropane triacrylate and a photopolymerization initiator, it has a large curing shrinkage, Warping increases. In addition, since the composition described in Patent Document 4 contains a large amount of dipentaerythritol hexaacrylate, epoxy acrylate, and the like, curing shrinkage is large and warping of the optical recording medium is large. Furthermore, since the composition described in Patent Document 5 contains many raw materials with high resin solubility, it is difficult to release from a resin mold such as polycarbonate.

  On the other hand, a composition containing a polybutadiene skeleton or a polyisoprene skeleton-containing urethane acrylate is known as a composition having a small polymerization shrinkage and a small warp of an optical recording medium (Patent Document 6). However, since the composition described in Patent Document 6 contains a large amount of tetrahydrofurfuryl acrylate, when used as an intermediate layer of a multilayer recording medium, the releasability from a resin mold such as polycarbonate is poor.

  Further, a casting photopolymerization composition comprising a polybutadiene skeleton-containing urethane acrylate and an alicyclic skeleton-containing acrylate is known, and application to optical members such as Fresnel lenses has been proposed (Patent Document 7). In Patent Document 7, release from a glass mold is performed, and by increasing the blending ratio of the polybutadiene skeleton-containing urethane acrylate, the cured product is prevented from cracking when released from the glass mold. However, as a result, the viscosity of the composition tends to increase. Since the thin film coating becomes difficult when the viscosity becomes high, the material described in Patent Document 79 is not suitable for use as an intermediate layer in a multilayer optical recording medium.

JP 2002-334490 A JP 2003-203402 A JP-A-62-88156 Japanese Patent No. 4247696 JP-A-5-59139 JP 2004-299263 A Japanese Patent Laid-Open No. 2003-73429

  An object of the present invention is to provide an active energy ray-curable resin composition capable of obtaining a cured product having good release properties from a polycarbonate mold and having a small warpage of the substrate due to curing shrinkage. .

The present invention is an active energy ray-curable resin composition for curing in a polycarbonate resin mold, the group comprising (A) a polybutadiene skeleton, a polyisoprene skeleton, a hydrogenated polybutadiene skeleton, and a hydrogenated polyisoprene skeleton. 5 to 35 parts by mass of urethane (meth) acrylate oligomer having one or more selected skeletons, (B) The molecular weight other than (A) component is 1000 or less and is negative in the following polycarbonate resin solubility test (meth) 65 to 95 parts by mass of a compound having an acryloyl group and (C) 0 to 5 parts by mass of a compound positive for the following polycarbonate resin solubility test [the total amount of polymerizable compounds in the composition is 100 parts by mass] Is an active energy ray-curable resin composition.
(Polycarbonate resin solubility test)
Drop 0.3 ml of the test solution on a 3 mm thick polycarbonate resin plate, leave it at 20 ° C. for 10 minutes, wipe off the test solution, and measure the haze value after wiping the polycarbonate resin plate under the test droplet. When the increase in the haze value after the test exceeds 10.0 as compared with the haze value before the test, it is evaluated as “positive” when the increase in the haze value after 10.0 or less is 10.0.

  Moreover, this invention is an article | item which consists of hardened | cured material of the said active energy ray hardening-type resin composition, and the surface is the uneven | corrugated shape to which the uneven | corrugated shape of the polycarbonate resin mold was transcribe | transferred.

  The present invention also provides an optical recording medium comprising a cured product of the active energy ray-curable resin composition as a constituent element.

  In the present invention, “(meth) acrylate” means “acrylate” or “methacrylate”, and “(meth) acryloyl group” means “acryloyl group” or “methacryloyl group”.

  ADVANTAGE OF THE INVENTION By this invention, the active energy ray hardening-type resin composition which can obtain the hardened | cured material with the favorable mold release property from a polycarbonate-made casting_mold | template and the small curvature of a board | substrate by hardening shrinkage can be provided. Further, by using this resin composition, it is possible to obtain an article or an optical recording medium in which the uneven shape of the mold is transferred and the warpage of the substrate is small.

It is a schematic diagram of the apparatus used in order to evaluate mold release property in an Example.

<(A) component>
In the present invention, the component (A) is a urethane (meth) acrylate oligomer having one or more skeletons selected from the group consisting of a polybutadiene skeleton, a polyisoprene skeleton, a hydrogenated polybutadiene skeleton, and a hydrogenated polyisoprene skeleton. This component (A) is a component that improves the low warpage of the cured product and the releasability from the polycarbonate mold.

The component (A) is obtained, for example, by reacting the following components (a1) to (a3).
(A1) A compound selected from the group consisting of polybutadiene glycol, polyisoprene glycol, hydrogenated polybutadiene glycol and hydrogenated polyisoprene glycol.
(A2) Organic diisocyanate compound.
(A3) A hydroxyl group-containing (meth) acrylic acid ester.

  The component (a1) is a component that improves the low warpage of the cured product and the releasability from the polycarbonate mold. Specific examples of the component (a1) include glycol compounds such as polybutadiene glycol and polyisoprene glycol synthesized from homopolymers of butadiene and isoprene, and hydrogenated compounds obtained by adding hydrogen thereto. These can be used alone or in combination of two or more. In particular, glycol compounds synthesized from polybutadiene and / or polyisoprene having a weight average molecular weight of 4000 or less are preferable. When the weight average molecular weight is 4000 or less, the resulting resin composition has a low viscosity and tends to be excellent in workability.

  The component (a2) is a component for introducing a urethane bond into the component (a1) and imparting surface hardness to the resulting cured product layer, and is also a component for adding the component (a3). The component (a2) preferably has a hydrolyzable chlorine content of 100 ppm or less from the viewpoint of imparting excellent recording film protection performance to the resulting cured product layer. Moreover, an alicyclic skeleton containing diisocyanate compound is more preferable from the point of light resistance. Specific examples of the component (a2) include isophorone diisocyanate, bis (4-isocyanatocyclohexyl) methane, 1,2-hydrogenated xylylene diisocyanate, 1,4-hydrogenated xylylene diisocyanate, and hydrogenated tetramethylxylylene diisocyanate. And norbornane diisocyanate. These can be used alone or in combination of two or more. Of these, isophorone diisocyanate and bis (4-isocyanatocyclohexyl) methane are preferred because of the excellent surface hardness of the resulting cured layer.

  The component (a3) is a component that imparts radical reactivity to the component (A). The component (a3) is not particularly limited as long as it is a compound having at least one (meth) acryloyloxy group and at least one hydroxy group in the molecule. Specific examples of the component (a3) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and cyclohexanedimethanol mono (Meth) acrylate, adduct of 2-hydroxyethyl (meth) acrylate and caprolactone, adduct of 4-hydroxybutyl (meth) acrylate and caprolactone, trimethylolpropane di (meth) acrylate, pentaerythritol tri (meth) acrylate, Examples include dipentaerythritol penta (meth) acrylate. These can be used alone or in combination of two or more. Of these, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate are preferable from the viewpoint of lowering the viscosity of the resulting resin composition.

  The synthesis method of the component (A) used in the present invention is not particularly limited, and a known synthesis method can be used. For example, in a mixture of the component (a1) and a catalyst such as di-n-butyltin dilaurate, the component (a2) is dropped and reacted at 50 to 90 ° C. to obtain a polyurethane precursor. It can be synthesized by reacting the component a3). Moreover, after reacting the component (a2) and the component (a3) first, the component (a1) may be reacted.

  Content of (A) component in the resin composition of this invention is 5-35 mass parts in the total amount of 100 mass parts of a polymeric compound, Preferably it is 10-25 mass parts. The lower limits of these ranges are significant in terms of warpage characteristics of the cured product and releasability from the mold. The upper limit value is significant in that the coating property is improved by reducing the viscosity of the resin composition, and in particular, thin film coating is facilitated. The total amount of the polymerizable compound is usually the total amount of the component (A), the component (B), and the component (C) (excluding the non-polymerizable compound), and this total amount is 100 parts by weight. The amount of each component is expressed as a reference. In addition, when the resin composition further includes any polymerizable compound other than these, the total amount of the components (A) to (C) and the arbitrary polymerizable compound is based on 100 parts by weight.

<(B) component>
In the present invention, the component (B) is a compound having a (meth) acryloyl group having a molecular weight other than the component (A) of 1000 or less and negative in the polycarbonate resin solubility test. This (B) component is a component which reduces the viscosity of a resin composition, without impairing the release property from the casting_mold | template of hardened | cured material.

  Specifically, the polycarbonate resin solubility test was performed as follows in the examples described later. First, polycarbonate resin (trade name Panlite L-1225-Z100, manufactured by Teijin Chemicals Ltd.) was injection-molded at a resin temperature of 340 ° C., a mold temperature of 90 ° C., and an injection speed of 120 mm / sec. 5 cm × 5 cm × 3 mm). On this polycarbonate resin plate, 0.3 ml of the monomer to be tested was dropped and allowed to stand at 20 ° C. for 10 minutes. Thereafter, the monomer was wiped off with Wes (trade name Kim Towel, manufactured by Nippon Paper Crecia Co., Ltd.). Then, using a haze meter (trade name HM-65W, manufactured by Murakami Color Research Co., Ltd.), the haze value of the polycarbonate resin plate at the position after dropping and wiping the liquid to be tested was measured, and the following judgment criteria The polycarbonate resin solubility was judged according to

Positive: Increased haze value after test> 10.0
Negative: Increased haze value after test ≦ 10.0
When the haze value before the test is Hzb% and the haze value after the test is Hza%, the increased haze value ΔHz is a value represented by Hza−Hzb. When the increased haze value is 10.0 or less, the releasability of the cured product from the mold is improved. If it is 5.0 or less, the releasability of the cured product from the mold is further improved.

  Content of (B) component in the resin composition of this invention is 65-95 mass parts in the total amount of 100 mass parts of a polymeric compound, Preferably it is 75-85 mass parts. The lower limit of these ranges is significant in terms of reducing the viscosity of the resin composition. The upper limit is significant in terms of releasability from the mold.

  Specific examples of the component (B) include isobornyl (meth) acrylate, hydroxypivalate neopentyl glycol ester di (meth) acrylate, ε-caprolactone-modified hydroxypivalate neopentyl glycol ester di (meth) acrylate, and γ-butyrolactone modification. Hydroxypivalic acid neopentyl glycol ester di (meth) acrylate, δ-valerolactone modified hydroxypivalic acid neopentyl glycol ester di (meth) acrylate, α-methyl-γ-butyrolactone modified neopentyl glycol ester di (meth) acrylate, β -Propiolactone-modified neopentyl glycol ester di (meth) acrylate, ethylene oxide-modified hydroxypivalic acid neopentyl glycol ester di (meth) Acrylate, neopentyl glycol modified trimethylolpropane di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, hydroxypivalate trimethylolpropane tri (meth) acrylate, pentaerythritol tri Polymerizable compound modified with (meth) acrylate and dipentaerythritol with an average of 3 alkinoyl or alkanoyl groups and an average of 3 acryloyl groups per molecule [trade name Kayarad D-330, Nippon Kayaku Co., Ltd. Manufactured], tris (acryloyloxyethyl) isocyanurate, and dipentaerythritol hexaacrylate. These can be used alone or in combination of two or more. Among these, from the viewpoint of mold releasability, low warpage, and viscosity of the cured product, a compound containing 1 to 3 (meth) acryloyl groups per molecule is preferable, and isobornyl (meth) acrylate, hydroxypentyl glycol neopentyl glycol Ester di (meth) acrylate is particularly preferred.

  From the viewpoint of the heat resistance of the cured product, it is preferable to use a compound having a glass transition temperature (Tg) of 120 ° C. or higher as a homopolymer as the component (B). 10-50 mass parts is preferable and, as for content of this compound, 20-40 mass parts is more preferable. The lower limit of these ranges is significant in terms of the heat resistance of the cured product. The upper limit is significant in terms of mold releasability and low warpage of the cured product. As such a compound, tris (acryloyloxyethyl) isocyanurate, neopentyl glycol-modified trimethylolpropane di (meth) acrylate, and tricyclodecane dimethanol di (meth) acrylate are particularly preferable. Using such a compound in combination with a compound preferable from the viewpoint of the releasability, low warpage and viscosity of the cured product listed above, that is, using two or more compounds in combination as the component (B) This is particularly preferable from the viewpoint of achieving both the heat resistance of the cured product and the releasability, low warpage, and viscosity.

<(C) component>
In the present invention, the component (C) is a compound that is positive in the polycarbonate resin solubility test. Specific examples of the component (C) include (meth) acryl having high solubility in polycarbonate resins such as tetrahydrofurfuryl (meth) acrylate, tridecaethylene glycol di (meth) acrylate, and tetradecaethylene glycol di (meth) arylate. Examples thereof include acid esters and other organic solvents having high solubility in polycarbonate resins such as ethyl acetate, butyl acetate, toluene, and xylene.

  Component (C) is highly soluble in polycarbonate resin. Therefore, when the resin composition of the present invention is used as a molding material for casting, it is preferable that the content of the component (C) is small from the viewpoint of releasability to the mold, and the component (C) is a resin composition. More preferably, it is not contained in the product. Specifically, the content of the component (C) in the resin composition of the present invention is 0 to 5 parts by mass, preferably 0 to 1 part by mass, more preferably 100 parts by mass of the total amount of polymerizable compounds. 0 parts by mass.

<Active energy ray-curable resin composition>
The active energy ray-curable resin composition of the present invention is a resin composition containing the above-described component (A), component (B) and optionally component (C).

  Furthermore, as long as the performance is not impaired, a polymerizable compound other than the components (A) to (C), a photopolymerization initiator, a thermoplastic polymer, a release agent, a leveling agent, an antioxidant, as necessary. In addition, a known material such as a rust inhibitor, a light stabilizer, an ultraviolet absorber, a polymerization inhibitor, a silane coupling agent, an inorganic filler, an organic filler, or a surface organically treated inorganic filler may be contained.

  In particular, the photopolymerization initiator is a component for accelerating the polymerization of the resin composition and efficiently obtaining a cured product. When the polymerization curability of the resin composition is good, the release property of the cured product from the mold becomes good.

  Specific examples of the photopolymerization initiator include benzophenone, 4,4-bis (diethylamino) benzophenone, 2,4,6-trimethylbenzophenone, methylorthobenzoylbenzoate, 4-phenylbenzophenone, t-butylanthraquinone, and 2-ethyl. Anthraquinone, 2,2-diethoxyacetophenone, methylphenylglyoxylate, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethyl ketal, 1-hydroxycyclohexyl-phenylketone, benzoin methyl ether, benzoin Ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- ( -Morpholinophenyl) -butanone-1, diethylthioxanthone, isopropylthioxanthone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis ( 2,4,6-trimethylbenzoyl) -phenylphosphine oxide, methylbenzoylformate, 2-hydroxy-1- [4- {4- (2-hydroxy-2-methyl-propionyl) -benzyl} -phenyl] -2 -Methyl-propan-1-one and the like. These can be used alone or in combination of two or more.

  When the resin composition of the present invention is used as a composition for optical articles, particularly when it is used for a cover layer or an intermediate layer of an optical recording medium in which the laser used for reading and / or writing is a blue laser, the blue color of the cured product From the point that the laser transmittance is good, benzophenone, 2,4,6-trimethylbenzophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl-phenyl ketone, benzoin methyl ether, Benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-diethoxyacetophenone, methylphenylglyoxylate, 2-hydroxy-1- [4- {4- (2-hydroxy-2-methyl-propionyl)- Benzyl} -phenyl] -2-methyl-propyl Pan-1-one is preferable. These can be used alone or in combination of two or more.

  The content of the photopolymerization initiator in the resin composition of the present invention is preferably 1 to 20 parts by mass, more preferably 5 to 15 parts by mass with respect to 100 parts by mass of the total amount of the polymerizable compounds. The lower limit of these ranges is significant in terms of curability of the resin composition. The upper limit is significant in that it reduces the coloration of the cured product.

  The viscosity of the resin composition of the present invention can be appropriately selected depending on the application, coating method and the like. For example, when the resin composition of the present invention is used for applications such as optical articles, multilayer recording optical recording medium intermediate layers and casting, it is 10 to 3000 mPa · s at 25 ° C. from the viewpoint of casting workability and defoaming property. The viscosity is preferably within the range of 50 to 500 mPa · s, and particularly preferably within the range of 50 to 500 mPa · s. By increasing the content of the component (A), the viscosity can be increased and adjusted to a desired viscosity.

  The resin composition of the present invention is a resin composition that is cured by irradiation with active energy rays. As the active energy rays, known active energy rays such as ultraviolet rays and electron beams can be used. The atmosphere irradiated with active energy rays may be air or an inert gas such as nitrogen or argon. Moreover, in addition to the hardening reaction by irradiation of an active energy ray, the hardening reaction by a heat | fever can be used together as needed.

  The cured product of the resin composition of the present invention preferably has a glass transition temperature (Tg) of 80 ° C. or higher. Moreover, it is preferable to prepare the resin composition by optimizing the types and blending ratios of the components so that the Tg of the cured product is 80 ° C. or higher.

  Since the resin composition of the present invention has small curing shrinkage, it is particularly suitable as a molding material for optical articles and a coating material for optical articles that require dimensional accuracy. In addition to such properties, it also has good releasability from polycarbonate molds, so optical article molding materials obtained by casting methods such as Fresnel lenses and prism sheets that require transferability in particular. And as an optical recording medium coating or intermediate layer forming material. When the optical recording medium is a read-only disk, the upper and lower layers of the intermediate layer are made of a metal reflective film such as aluminum or silver. In the case of a writable disc, the upper layer and the lower layer of the intermediate layer are constituted by, for example, an optical recording layer in which a reflective film, a dielectric film, a recording film, and a dielectric film are sequentially laminated.

  Examples of the method for casting and curing the resin composition of the present invention include the methods described in Patent Documents 1 and 2 described above.

  The cured product of the resin composition of the present invention is suitable for an article whose surface has an uneven shape. Although the uneven shape is not particularly limited, for example, when it is used as an intermediate layer for an optical disk, an uneven pattern shape such as a spiral land, groove, pre-pit or the like can be mentioned.

  The uneven shape can be obtained by, for example, injecting a resin composition into a transparent polycarbonate resin mold having a base shape of the uneven shape, irradiating it with an active energy ray such as ultraviolet rays, and then removing the mold. Can be transferred and formed.

  The cured product of the resin composition of the present invention is suitable as a constituent element of an optical recording medium as described above, and more particularly as an intermediate layer of a multilayer recording medium.

  Hereinafter, the present invention will be described in detail with reference to examples. Various evaluations in the examples were performed according to the following methods.

(1) Viscosity (Unit: mPa · s)
The viscosity of the curable composition was measured using an E-type viscometer (TVE-20, manufactured by Toki Sangyo Co., Ltd.) at 25 ° C.

(2) Releasability (unit: N)
The releasability of the cured product layer from the polycarbonate mold for optical discs during the production of the optical recording medium substrate for evaluation was evaluated based on the following criteria using the apparatus shown in FIG.
1. A stainless steel suction cup unit 2 equipped with a suction function was attached to a digital force gauge 1 (FGP-5, manufactured by Nidec Simpo Co., Ltd.).
2. The sample disk substrate is placed on a stainless steel sample table 3 having a silicone rubber pad 4 (inner diameter: 22 mm, outer diameter: 32 mm, thickness: 1 mm) with the mold facing upward, and the sample disk is sucked by the lower suction nozzle 5. Fixed.
3. The suction cup unit 2 attached to the digital force gauge 1 was adsorbed to the mold and then sucked by the upper suction nozzle 5 to adsorb the suction cup to the mold.
4). The digital force gauge 1 was pulled up vertically to release the mold. The force (release force) required for release at this time was measured with a digital force gauge 1.
“A”: The release force is less than 5.0 N.
“◯”: The mold release force is 5.0 N or more and less than 10.0 N.
“×”: The release force was 10.0 N or more, or release was not possible.

(3) Low warpage (unit: °)
For the disk substrate released from the mold in the above-described mold release test, use an offline disk inspection system (PRO meteus MT-200. Blue, manufactured by Dr. Schenk GmbH Industrimesstechnik) in an environment of 23 ° C and 50% relative humidity. The warp angle was measured. The warp angle means an average value of Radial Deviation (measurement point: 256 points) at a position 45 mm from the center of the optical recording medium. Further, a negative (−) value means that the cured product layer is warped, and a positive (+) means that the cured product layer is warped on the opposite side.
“◎”: Within ± 0.20 °.
“◯”: exceeding ± 0.20 ° and within ± 0.40 °.
“X”: exceeds ± 0.40 °.

(4) Heat resistance A resin composition is formed on a glass plate using a baker applicator (Model: SC-8310, manufactured by Ueshima Seisakusho Co., Ltd.) so that the film thickness after curing is 100 μm, and a high-pressure mercury lamp. Was irradiated with ultraviolet rays at 500 mJ / cm ² to obtain a cured product. The cured product was peeled off from the glass plate, and the glass transition temperature (Tg) was measured using a viscoelasticity analyzer (RSA-II, manufactured by TA Instruments) (frequency 11 rad / sec, temperature rising rate 3 ° C. / Min).
“◎”: Tg of 80 ° C. or higher.
"(Circle)": Tg is 70 degreeC or more and less than 80 degreeC.
"X": Tg is less than 70 degreeC.

<Synthesis Example 1 (Synthesis of UA1)>
In a flask equipped with a heat retaining function, a reflux condenser, a stirring blade, and a temperature sensor, 222 g (1 mol) of isophorone diisocyanate and 0.437 g of di-n-butyltin dilaurate (300 ppm based on the total charged amount) were charged. Warmed to ° C. Next, 116 g (1 mol) of 2-hydroxyethyl acrylate was added dropwise over 2 hours, and the mixture was further stirred for 2 hours. In a state where the dripping funnel with a heat retaining function is heated to 40 ° C., 1120 g (0.5 mol) of polybutadiene glycol (trade name NISSO PB G-2000, weight average molecular weight 2240, manufactured by Nippon Soda Co., Ltd.) as a glycol compound for 2 hours. It was dripped over. After stirring at 50 ° C. for 2 hours, the temperature was raised to 70 ° C. over 1 hour and further stirred for 4 hours to synthesize urethane acrylate (UA1). The weight average molecular weight (Mw) of this urethane acrylate (UA1) was 6800 [polystyrene equivalent value, measured with a high-speed GPC measuring apparatus (trade name HLC-8320GPC EcoSEC, manufactured by Tosoh Corporation)].

<Synthesis Example 2 (Synthesis of UA2)>
As a glycol compound, 675 g (0.5 mol) of polybutadiene glycol (trade name NISSO PB G-1000, weight average molecular weight 1350, manufactured by Nippon Soda Co., Ltd.) is used, and the amount of di-n-butyltin dilaurate used is 0.5. Except having changed to 304 g (300 ppm with respect to the total preparation amount), it synthesize | combined similarly to the synthesis example 1, and obtained urethane acrylate (UA2). Mw of this urethane acrylate (UA2) was 5300.

<Synthesis Example 3 (Synthesis of UA3)>
As the glycol compound, 850 g (0.5 mol) of hydrogenated polybutadiene glycol (trade name NISSO PB GI-1000, weight average molecular weight 1700, manufactured by Nippon Soda Co., Ltd.) is used, and the amount of di-n-butyltin dilaurate used is A urethane acrylate (UA3) was obtained in the same manner as in Synthesis Example 1 except that the amount was changed to 0.356 g (300 ppm with respect to the total charged amount). Mw of this urethane acrylate (UA3) was 4600.

<Synthesis Example 4 (Synthesis of UA4)>
As the glycol compound, 325 g (0.5 mol) of polytetramethylene glycol (trade name PTG650SN, weight average molecular weight 650, manufactured by Hodogaya Chemical Co., Ltd.) was used, and the amount of di-n-butyltin dilaurate used was 0.199 g. Except having changed to (300 ppm with respect to the total preparation amount), it synthesize | combined similarly to the synthesis example 1, and obtained urethane acrylate (UA4). Mw of this urethane acrylate (UA4) was 2400.

<Synthesis Example 5 (Synthesis of UA5)>
As the glycol compound, 265 g (0.5 mol) of polycaprolactone glycol (trade name Plaxel 205, weight average molecular weight 530, manufactured by Daicel Chemical Industries, Ltd.) was used, and the amount of di-n-butyltin dilaurate used was 0.181 g. The synthesis was performed in the same manner as in Synthesis Example 1 except that the amount was changed to (300 ppm with respect to the total charge amount), and urethane acrylate (UA5). The Mw of this urethane acrylate (UA5) was 2300.

<Synthesis Example 6 (Synthesis of UA6)>
As the glycol compound, 400 g (0.5 mol) of polycarbonate glycol (trade name Duranol T5650J, weight average molecular weight 800, manufactured by Asahi Kasei Chemicals Corporation) was used, and the amount of di-n-butyltin dilaurate used was 0.221 g (total Except having changed into 300 ppm) with respect to preparation amount, it synthesize | combined similarly to the synthesis example 1, and obtained urethane acrylate (UA6). Mw of this urethane acrylate (UA6) was 2700.

[Example 1]
Each raw material was mix | blended with the mixture ratio (mass part) shown in Table 1, and the active energy ray hardening-type resin composition was prepared.

  Separately from this, 50 g of urethane acrylate (UA4) obtained in Synthesis Example 4, 40 g of tetrahydrofurfuryl acrylate, 10 g of trimethylolpropane triacrylate, 5 g of 1-hydroxycyclohexyl-phenylketone, 0.2 g of 2-methacryloyloxyethyl acid phosphate. 1 g was mixed to prepare an adhesive composition A.

A polycarbonate mold for an optical disk having a hole for holding a spindle in the center obtained by injection molding of polycarbonate resin (diameter 12 cm, plate thickness 0.6 mm, warp angle 0 degree, track pitch 0.7 μm, groove width 0.3 μm, The active energy ray-curable resin composition is spin-coated on a signal surface (surface having a groove) having a groove depth of 0.2 μm so as to have a cured film thickness of 10 μm, and ultraviolet rays are applied by a high-pressure mercury lamp at 500 mJ / cm. ² (ultraviolet light meter: trade name UV-351SN type, measured value manufactured by Oak Seisakusho Co., Ltd.) is irradiated to form a release layer by curing the active energy ray-curable resin composition on the mold, A mold with a release layer was obtained.

  On the other hand, on the signal surface of an optical disk substrate (diameter: 12 cm, plate thickness: 1.1 mm, warp angle: 0 degree) having a spindle holding hole in the center obtained by injection molding of polycarbonate resin, the film thickness is obtained by sputtering. A 0.05 μm silver thin film was formed to obtain a substrate with a silver thin film.

The adhesive composition A is placed on the silver thin film of the substrate with the silver thin film, the mold with the release layer is placed so that the release layer is in contact with the adhesive composition, and then the adhesive composition A is cured. The substrate and the mold were rotated as a unit so as to have a thickness of 15 μm, and the excess adhesive composition A was shaken off to spread the adhesive composition A between the substrate and the release layer. Next, the coating film of the adhesive composition A was cured by irradiating with 500 mJ / cm ² of ultraviolet rays from the mold side with a release layer with a high pressure mercury lamp. Thereafter, by releasing from the mold, a laminate in which a silver thin film, an adhesive layer and a release layer were sequentially laminated on the substrate was obtained. The evaluation results are shown in Table 1.

[Examples 2 to 10, Comparative Examples 1 to 7]
A laminate was obtained in the same manner as in Example 1 except that the raw materials were blended at the blending ratios shown in Table 1 and Table 2 to prepare an active energy ray-curable resin composition. The evaluation results are shown in Tables 1 and 2.

[Example 11]
Each raw material was mix | blended with the mixture ratio shown in Table 3, and the active energy ray hardening-type resin composition was prepared.

A substrate with a silver thin film was produced in the same manner as in Example 1. On the silver thin film of the substrate with the silver thin film, the adhesive composition A obtained by the same method as in Example 1 was spin-coated so that the film thickness after curing was 15 μm, and ultraviolet rays were applied at 500 mJ / cm ² with a high-pressure mercury lamp. Irradiation was performed to cure the coating film of the adhesive composition A. The active energy ray-curable resin composition is placed on the cured film (adhesive layer) of the adhesive composition A, and further, the same polycarbonate mold for optical disk as in Example 1 (no release layer). Are placed so that their signal surfaces are in contact with each other, and then the substrate and the mold are rotated together so that the film thickness after curing of the active energy ray-curable resin becomes 10 μm, so that an excess active energy ray-curable resin composition is obtained. The active energy ray-curable resin composition was spread over the entire area between the substrate and the mold. Next, a release layer was formed by curing the active energy ray-curable resin composition by irradiating ultraviolet rays with 500 mJ / cm ² from a mold side with a high-pressure mercury lamp. Thereafter, by releasing from the mold, a laminate in which a silver thin film, an adhesive layer and a release layer were sequentially laminated on the substrate was obtained. The evaluation results are shown in Table 3.

[Examples 12 to 20, Comparative Examples 8 to 14]
A laminate was obtained in the same manner as in Example 11 except that the raw materials were blended at the blending ratios shown in Table 3 and Table 4 to prepare an active energy ray-curable resin composition. The evaluation results are shown in Tables 3 and 4.

[Example 21]
Each raw material was mix | blended with the compounding ratio shown in Table 5, and the active energy ray hardening-type resin composition was prepared.

A substrate with a silver thin film was produced in the same manner as in Example 1. The active energy ray-curable resin composition is placed on the silver thin film of the substrate with the silver thin film, and the same polycarbonate mold for optical disk as in Example 1 (with no release layer) is used as the signal. After placing the surfaces in contact with each other, the substrate and the mold are rotated together so that the thickness of the active energy ray-curable resin after curing is 25 μm, and the excess active energy ray-curable resin composition is shaken off. The active energy ray-curable resin composition was spread between the substrate and the mold. Next, a release layer was formed by curing the active energy ray-curable resin composition by irradiating ultraviolet rays with 500 mJ / cm ² from a mold side with a high-pressure mercury lamp. After that, by releasing from the mold, a laminate in which a silver thin film and a release layer were sequentially laminated on the substrate was obtained. The evaluation results are shown in Table 5.

[Examples 22 to 30, Comparative Examples 15 to 21]
A laminate was obtained in the same manner as in Example 21 except that the raw materials were blended at the blending ratios shown in Table 5 and Table 6 to prepare an active energy ray-curable resin composition. The evaluation results are shown in Tables 5 and 6.

Abbreviations in each table are as follows.
"UA1": urethane acrylate compound synthesized in Synthesis Example 1 "UA2": urethane acrylate compound synthesized in Synthesis Example 2 "UA3": urethane acrylate compound synthesized in Synthesis Example 3 "IBXA": isobornyl Acrylate (Molecular weight 208)
"R604": Neopentyl glycol-modified trimethylolpropane diacrylate (trade name Kayarad R-604, (molecular weight 326), manufactured by Nippon Kayaku Co., Ltd.)
"TAIC": Tris (2-acryloyloxyethyl) isocyanurate (molecular weight 387)
"EHA": 2-ethylhexyl acrylate (molecular weight 232)
"APMA": 2-methacryloyloxyethyl acid phosphate (molecular weight 198)
-"THFA": Tetrahydrofurfuryl acrylate-"M260": Mixture of tridecaethylene glycol diacrylate and tetradecaethylene glycol diarylate (trade name Aronix M-260, manufactured by Toagosei Co., Ltd.)
"UA4": urethane acrylate compound synthesized in Synthesis Example 4 "UA5": urethane acrylate compound synthesized in Synthesis Example 5 "UA6": urethane acrylate compound synthesized in Synthesis Example 6 "BAC-15": polybutadiene Glycol diacrylate (trade name BAC-15, manufactured by Osaka Organic Chemical Industry Co., Ltd., weight average molecular weight 1200)
“HCPK”: 1-hydroxycyclohexyl-phenyl ketone

1 Digital Force Gauge 2 Stainless Steel Sucker Unit 3 Stainless Steel Sample Base 4 Silicone Rubber Pad 5 Suction Nozzle

Claims (6)

An active energy ray-curable resin composition for curing in a polycarbonate resin mold,
(A) 5 to 35 parts by mass of a urethane (meth) acrylate oligomer having at least one skeleton selected from the group consisting of a polybutadiene skeleton, a polyisoprene skeleton, a hydrogenated polybutadiene skeleton, and a hydrogenated polyisoprene skeleton,
(B) 65 to 95 parts by mass of a compound having a (meth) acryloyl group having a molecular weight other than the component (A) of 1000 or less and negative in the following polycarbonate resin solubility test;
(C) 0 to 5 parts by mass of a compound positive for the following polycarbonate resin solubility test [the total amount of polymerizable compounds in the composition is 100 parts by mass]
An active energy ray-curable resin composition comprising:
(Polycarbonate resin solubility test)
Drop 0.3 ml of the test solution on a 3 mm thick polycarbonate resin plate, leave it at 20 ° C. for 10 minutes, wipe off the test solution, and measure the haze value after wiping the polycarbonate resin plate under the test droplet. When the increase in the haze value after the test exceeds 10.0 as compared with the haze value before the test, it is evaluated as “positive” when the increase in the haze value after 10.0 or less is 10.0.   The active energy ray-curable resin composition according to claim 1, wherein the cured product has a glass transition temperature of 80 ° C. or higher.   The active energy ray-curable resin composition according to claim 1, wherein the viscosity at 25 ° C. is in the range of 50 to 500 mPa · s.   An article comprising a cured product of the active energy ray-curable resin composition according to any one of claims 1 to 3, the surface of which is an uneven shape to which the uneven shape of a polycarbonate resin mold is transferred.   The optical recording medium which contains the hardened | cured material of the active energy ray curable resin composition as described in any one of Claims 1-3 as a component.   An optical recording medium comprising the cured product of the active energy ray-curable resin composition according to claim 1 as an intermediate layer of the multilayer recording medium.

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