JP2004342182A - Optical information medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical information medium having excellent antifoulling properties of the surface on the recording and/or reproducing beam incident side and excellent error rate characteristics at the time of reproduction even when a fingerprint is stuck to the surface. <P>SOLUTION: The optical information medium is formed so that when a dispersion liquid for evaluation containing 0.4 pts.wt. Kanto loam of a 11th kind of test powder 1 specified in JIS Z8901 as a minute particle substance, 1 pts.wt. triolein as a dispersing medium and 10 pts.wt. methoxypropanol as a diluent is stuck to the surface on the recording and/or reproducing beam incident side of the optical information medium with a certain procedure, the ratio of the surface area occupied by the drops of the dispersion liquid for evaluation stuck to a unit surface area of the surface to which a sticking operation is performed is 6% or below. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０１１０】
［ディスクサンプルＮｏ．３の作製：本発明］
ディスクサンプルＮｏ．２におけるハードコート剤の組成を以下のように変更した以外は、ディスクサンプルＮｏ．２におけるのと同様にしてディスクサンプルＮｏ．３を作製した。
【０１１１】
（ハードコート剤の組成）
反応性基修飾コロイダルシリカ（分散媒：プロピレングリコールモノメチルエー
テルアセテート、不揮発分：４０重量％） １００重量部
ジペンタエリスリトールヘキサアクリレート ４８重量部
テトラヒドロフルフリルアクリレート １２重量部
プロピレングリコールモノメチルエーテルアセテート ４０重量部
（非反応性希釈溶剤）
イルガキュア１８４（重合開始剤） ５重量部
２官能シリコーンメタクリレート ０．２５重量部
（信越化学工業（株）製、Ｘ−２２−１６４Ａ）
【０１１２】
［ディスクサンプルＮｏ．４の作製：比較例］
ディスクサンプルＮｏ．２におけるハードコート剤の組成を以下のように変更した以外は、ディスクサンプルＮｏ．２におけるのと同様にしてディスクサンプルＮｏ．４を作製した。
【０１１３】
（ハードコート剤の組成）
反応性基修飾コロイダルシリカ（分散媒：プロピレングリコールモノメチルエー
テルアセテート、不揮発分：４０重量％） １００重量部
２官能シリコーンメタクリレート ０．０５重量部
（信越化学工業（株）製、Ｘ−２２−１６４Ａ、分子量１５００）
ジペンタエリスリトールヘキサアクリレート ４８重量部
テトラヒドロフルフリルアクリレート １２重量部
プロピレングリコールモノメチルエーテルアセテート ４０重量部
（非反応性希釈溶剤）
イルガキュア１８４（重合開始剤） ５重量部
【０１１４】
［ディスクサンプルＮｏ．５の作製：比較例］
ディスクサンプルＮｏ．２におけるハードコート剤の組成を以下のように変更した以外は、ディスクサンプルＮｏ．２におけるのと同様にしてディスクサンプルＮｏ．５を作製した。
【０１１５】
（ハードコート剤の組成）
反応性基修飾コロイダルシリカ（分散媒：プロピレングリコールモノメチルエー
テルアセテート、不揮発分：４０重量％） １００重量部
２官能シリコーンメタクリレート ０．０２５重量部
（信越化学工業（株）製、Ｘ−２２−１６４Ａ、分子量１５００）
ジペンタエリスリトールヘキサアクリレート ４８重量部
テトラヒドロフルフリルアクリレート １２重量部
プロピレングリコールモノメチルエーテルアセテート ４０重量部
（非反応性希釈溶剤）
イルガキュア１８４（重合開始剤） ５重量部
【０１１６】
［ディスクサンプルＮｏ．６の作製：比較例］
ディスクサンプルＮｏ．２におけるハードコート剤の組成を以下のように変更した以外は、ディスクサンプルＮｏ．２におけるのと同様にしてディスクサンプルＮｏ．６を作製した。
【０１１７】
（ハードコート剤の組成）
反応性基修飾コロイダルシリカ（分散媒：プロピレングリコールモノメチルエー
テルアセテート、不揮発分：４０重量％） １００重量部
ジペンタエリスリトールヘキサアクリレート ４８重量部
テトラヒドロフルフリルアクリレート １２重量部
プロピレングリコールモノメチルエーテルアセテート ４０重量部
（非反応性希釈溶剤）
イルガキュア１８４（重合開始剤） ５重量部
【０１１８】
［ディスクサンプルへの評価用分散液の付着］
（評価用分散液の調製）
微粒子状物質としてＪＩＳ Ｚ８９０１に定められた試験用粉体１第１１種（中位径：１．６〜２．３μｍ）の関東ローム０．４重量部、分散媒としてトリオレイン１重量部、さらに希釈剤としてメトキシプロパノール１０重量部を混合・攪拌して、評価用分散液とした。
【０１１９】
（評価用分散液転写用の原版の作製）
評価用分散液転写用の原版を次のようにして作製した。評価用分散液をマグネティックスターラーでよく攪拌しながら１ｍＬを採取し、ポリカーボネート製基板（直径１２０ｍｍ、厚さ１．２ｍｍ）上にスピンコート法により塗布した。スピンコートは、評価用分散液の１ｍＬを基板上に滴下し、５００ｒｐｍで３秒間回転させ、続いて直ぐに２５０ｒｐｍで３秒間回転させて行った。この基板を６０℃で３分間加熱して、不要な希釈剤であるメトキシプロパノールを完全に除去した。このようにして、評価用分散液転写用の原版を得た。
【０１２０】
（ディスクサンプル表面への評価用分散液の転写）
各ディスクサンプルのハードコート層（８） 又は表面層（９） 表面への評価用分散液成分の転写を、次に示す付着レベル３でそれぞれ行った。
【０１２１】
付着レベル３：
Ｎｏ．１のシリコーンゴム栓の小さい方の端面（直径１２ｍｍ）を、＃２４０の研磨紙（ＪＩＳ Ｒ６２５１又はＪＩＳ Ｒ６２５２規定のＡＡ２４０研磨紙と同等性能を有する）で一様に粗くしたものを擬似指紋転写材として用いた。擬似指紋転写材の粗くされた端面を、上記原版に荷重４．９Ｎで１０秒間押し当てて、評価用分散液成分を転写材の前記端面に移行させた。
【０１２２】
その後、評価用分散液成分が付着された転写材の前記端面を、ポリカーボネート基板の平滑な面に荷重４．９Ｎで１０秒間押し当てて、転写材の前記端面の評価用分散液成分付着量を低減させた。再度、転写材の前記端面を、ポリカーボネート基板の異なる箇所に荷重４．９Ｎで１０秒間押し当てて、転写材の前記端面の評価用分散液成分付着量をさらに低減させた。
【０１２３】
次いで、各ディスクサンプルのハードコート層（８） 又は表面層（９） 表面の中心から半径方向に４０ｍｍ付近のところに、評価用分散液成分が付着された転写材の前記端面を荷重４．９Ｎで１０秒間押し当てて、評価用分散液成分を転写した。
【０１２４】
さらに、ディスクサンプルＮｏ．１及び３については、各ディスクサンプルのハードコート層（８） 又は表面層（９） 表面への評価用分散液成分の転写を、次に示す付着レベル１でもそれぞれ行った。
【０１２５】
付着レベル１：
上記付着レベル３の操作において、転写材の評価用分散液成分付着量の低減操作を行わなかった。
【０１２６】
（表面の単位面積当たりに付着した評価用分散液滴が占める面積割合の測定）
各ディスクサンプルの表面に付着した評価用分散液滴の状態を、光学顕微鏡（キーエンス製、ＶＫ−８５１０）で観察し、その画像をプリンター（キーエンス製、ＶＨ−Ｐ４０）で出力した。その画像をコンピュータ内に取り込み、画像処理解析ソフトＷｉｎ ＲＯＯＦ Ｖｅｒ．３．６１デモ版（三谷商事（株）製）で評価用分散液滴部分の全体に対する面積割合を計測した。付着レベル３の結果を表１に示し、付着レベル１の結果を表２に示す。
【０１２７】
［ディスクサンプルＮｏ．１〜６の評価］
（初期エラーレートの測定）
各ディスクサンプルに光記録媒体評価装置（パルステック工業製、ＤＤＵ−１０００）を用いて次の条件：
レーザー波長λ：４０５ｎｍ，対物レンズのＮＡ：０．８５，変調方式：（１，７）ＲＬＬ，チャンネルビット長：０．１２μｍ，記録線速度：５．３ｍ／ｓ，チャンネルクロック：６６ＭＨｚ，記録信号：２Ｔ〜８Ｔの混合信号，データ転送速度：３６Ｍｂｐｓ
で記録を行った後、同じ評価装置（ＤＤＵ−１０００、レーザー波長λ：４０５ｎｍ、ＮＡ：０．８５）でビットバイビットのエラーレート（ｂＥＲ）を測定した（初期エラーレート）。各ディスクサンプルの初期エラーレートは、０又は１×１０^−７のいずれかであった。
【０１２８】
（エラーレートの測定Ｉ）
各ディスクサンプルに上記と同条件で記録を行った後、各ディスクサンプルのハードコート層（８） 又は表面層（９） 表面に上記付着レベル３の操作で評価用分散液滴を付着させ、評価用分散液滴が付着した状態で、上記と同様にビットバイビットのエラーレート−Ｉ（ｂＥＲ−Ｉ）を測定した。なお、この時、評価用分散液滴を付着させた部分を中心として４ｍｓｅｃ分のゲートを開いて測定を行った。
【０１２９】
（エラーレートの測定ＩＩ）
未記録の各ディスクサンプルのハードコート層（８） 又は表面層（９） 表面に上記付着レベル３の操作で評価用分散液滴を付着させ、評価用分散液滴が付着した状態で、上記と同条件で記録を行った。その後、上記と同様にビットバイビットのエラーレート−ＩＩ（ｂＥＲ−ＩＩ）を測定した。なお、この時、評価用分散液滴を付着させた部分を中心として４ｍｓｅｃ分のゲートを開いて測定を行った。
【０１３０】
以上の測定結果を表１に示す。
【０１３１】
【表１】

【０１３２】
表１より、本発明のディスクサンプルＮｏ．１〜３では、記録後に付着レベル３で評価用分散液滴が付着した状態で、エラーレート−Ｉがそれぞれ２×１０^−６、１×１０^−５、６×１０^−５と実用範囲（１×１０^−４以下）内であり、良好に再生できることが示された。すなわち、付着レベル３での面積割合が６％以下であると、高い耐指紋付着性を有しており、少なくとも再生専用の光ディスクとして良好に用いることができる。
【０１３３】
本発明の好ましいディスクサンプルＮｏ．１及び２では、未記録で付着レベル３で評価用分散液滴が付着した状態で、記録を行っても、エラーレート−ＩＩがそれぞれ１×１０^−７、９×１０^−５と実用範囲（１×１０^−４以下）内であり、良好に記録及び再生できることが示された。すなわち、付着レベル３での面積割合が４．８％以下であると、より高い耐指紋付着性を有しており、１回のみ記録可能な光ディスクや、書換え可能型光ディスクとしても良好に用いることができる。
【０１３４】
なお、ディスクサンプルＮｏ．１、３、４、５及び６について、２０℃、６０％ＲＨの環境下でトリオレインを測定液として静止接触角を測定したところ、表１に示す値が得られた。測定は、協和界面科学（株）の接触角計 ＦＡＣＥ ＣＯＮＴＡＣＴ−ＡＮＧＬＥＭＥＴＥＲを用いて行った。
【０１３５】
（エラーレートの測定ＩＩＩ ）
ディスクサンプルＮｏ．１及び３について、付着レベル１での評価を行った。
未記録の各ディスクサンプルのハードコート層（８） 又は表面層（９） 表面に上記付着レベル１の操作で評価用分散液滴を付着させ、評価用分散液滴が付着した状態で、上記と同条件で記録を行った。その後、上記と同様にビットバイビットのエラーレート−ＩＩＩ （ｂＥＲ−ＩＩＩ ）を測定した。なお、この時、評価用分散液滴を付着させた部分を中心として４ｍｓｅｃ分のゲートを開いて測定を行った。以上の測定結果を表２に示す。
【０１３６】
【表２】

【０１３７】
本発明の好ましいディスクサンプルＮｏ．１では、未記録で付着レベル１で評価用分散液滴が付着した状態で、記録を行っても、エラーレート−ＩＩＩ が１×１０^−５と実用範囲（１×１０^−４以下）内であり、良好に記録及び再生できることが示された。すなわち、付着レベル１での面積割合が４．９％以下であると、非常に高い耐指紋付着性を有している。
【０１３８】
［ディスクサンプルＮｏ．７の作製：本発明］
第１誘電体層（５１）の形成までは、上記ディスクサンプルＮｏ．１の場合と同様に行った。
【０１３９】
第１誘電体層（５１）表面に、上記ディスクサンプルＮｏ．１の光透過層（７） の形成に用いたのと同じ紫外線硬化性材料をスピンコート法により塗布して、樹脂材料層を硬化後の厚さ２μｍとなるように形成した。
【０１４０】
次いで、真空中（０．１気圧以下）において、厚さ１００μｍのポリカーボネートシートを、未硬化の樹脂材料層上に載置した。前記ポリカーボネートシートとしては、流延法によって製造された帝人（株）製のピュアエースを用いた。次いで、大気圧雰囲気に戻し、紫外線を照射して樹脂材料層を硬化することにより、前記ポリカーボネートシートを接着し、これを光透過層（７） とした。
【０１４１】
上記ディスクサンプルＮｏ．１の場合と同様にして、光透過層（７） 上に硬化後の厚さ２μｍのハードコート層（８） を形成し、ハードコート層（８） 上に硬化後の厚さ約３０ｎｍの表面層（９） を形成した。このようにしてディスクサンプルＮｏ．７を作製した。
【０１４２】
ディスクサンプルＮｏ．７について、ディスクサンプルＮｏ．１の場合と同様にして評価を行ったところ、同じ結果が得られた。
【０１４３】
上記実施例では、相変化型光ディスクの例を示した。しかしながら、本発明は、記録層が相変化型の光ディスクのみならず、再生専用型光ディスクや、追記型光ディスクにも適用される。そのため、前述の実施例はあらゆる点で単なる例示にすぎず、限定的に解釈してはならない。さらに、特許請求の範囲の均等範囲に属する変更は、すべて本発明の範囲内のものである。
【０１４４】
【発明の効果】
本発明によれば、記録及び／又は再生ビーム入射側表面の防汚性及び耐指紋付着性に優れ、前記表面に指紋が付着した場合においてもその付着量は少なく、再生時のエラーレート特性に非常に優れる光情報媒体が提供される。
【０１４５】
本発明によれば、記録及び／又は再生ビーム入射側表面の防汚性及び耐指紋付着性に優れ、前記表面に指紋が付着した後に記録した場合においても、エラーレート特性に非常に優れる光情報媒体が提供される。
【図面の簡単な説明】
【図１】光情報媒体の一つの構成例を示す概略断面図である。
【図２】光情報媒体の他の構成例を示す概略断面図である。
【図３】光情報媒体の他の構成例を示す概略断面図である。
【図４】光情報媒体の他の構成例を示す概略断面図である。
【図５】光情報媒体の他の構成例を示す概略断面図である。
【符号の説明】
（２０）：支持基体
（３） ：反射層
（５２）：第２誘電体層
（４） ：記録層
（５１）：第１誘電体層
（７） ：光透過層
（８） ：ハードコート層
（９） ：表面層[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an optical information medium such as a read-only optical disk, an optical recording disk, and a magneto-optical recording disk, and more particularly, to an optical information medium having excellent antifouling properties on a recording and / or reproducing beam incident side surface and excellent error rate characteristics. Media related.
[0002]
[Prior art]
When used, the surface of an optical disk such as a read-only optical disk, an optical recording disk, or a magneto-optical recording disk is contaminated by various contaminants or adheres to fingerprints. Such contamination and attachment of fingerprints are not preferable, and an appropriate surface treatment may be applied to the surface of the optical disc to improve antifouling property, reduce fingerprint adhesion, or improve fingerprint removability. For example, various water-repellent and oil-repellent treatments are being studied on the surface of an optical disc.
[0003]
Particularly in recent years, in optical information media, it is required to further increase the recording density in order to store enormous information such as moving image information, and research and development are being actively conducted to further increase the recording capacity. I have. One of the proposals is to shorten the recording / reproducing wavelength, increase the numerical aperture (NA) of the objective lens, and reduce the focused spot diameter of the recording / reproducing beam, as seen in DVDs, for example. Have been. Actually, when compared with a CD, the recording / reproducing wavelength is changed from 780 nm to 650 nm, and the numerical aperture (NA) is changed from 0.45 to 0.60, so that the recording capacity of 6 to 8 times (4.7 GB / surface) is obtained. ) Has been achieved. Recently, as a method for recording a high-quality moving image for a long time, the recording / reproducing wavelength is further reduced to about 400 nm and the numerical aperture is increased to 0.85, so that the recording capacity of the DVD is four times or more. A Blu-ray Disc that achieves the above has been commercialized.
[0004]
As the recording density is increased in this manner, the diameter of the focused spot of the recording / reproducing beam on the recording / reproducing beam incident side surface of the medium becomes smaller (the spot area on a Blu-ray Disc is about 7% of that of a DVD). Further, the medium becomes more sensitive to dust, fingerprints, and the like adhering to the surface on the laser beam incident side of the medium than before. In particular, with regard to dirt containing organic substances such as fingerprints, there is a large effect when the dirt adheres to the surface of the medium on the laser beam incident side, and it is difficult to remove it, so many measures have been considered so far. ing.
[0005]
For example, JP-A-10-110118 and JP-A-11-293159 disclose that when a hard coat agent coating film is formed on the surface of an optical disk substrate made of polycarbonate or the like, non-crosslinking fluorine is contained in the hard coat agent. It has been proposed to incorporate a surfactant.
[0006]
JP-A-2002-190136 discloses an optical information medium having excellent surface antifouling properties.
[0007]
WO 03/029382 A1 discloses an optical information medium having excellent surface fingerprint removability, and discloses an artificial fingerprint liquid for quantitatively evaluating the fingerprint removability and the like of the optical information medium surface. The artificial fingerprint liquid includes a particulate matter and a dispersion medium capable of dispersing the particulate matter.
[0008]
[Patent Document 1]
JP-A-10-110118
[Patent Document 2]
JP-A-11-293159
[Patent Document 3]
JP-A-2002-190136
[Patent Document 4]
WO 03/029382 A1
[0009]
[Problems to be solved by the invention]
An object of the present invention is to provide an optical information medium having excellent antifouling properties on a recording and / or reproducing beam incident side surface and having extremely excellent error rate characteristics at the time of reproducing even when a fingerprint adheres to the surface. It is in.
[0010]
A further object of the present invention is to provide an optical information medium having excellent antifouling properties on the recording and / or reproducing beam incident side surface and having extremely excellent error rate characteristics even when recording is performed after a fingerprint is attached to the surface. It is in.
[0011]
[Means for Solving the Problems]
The present invention includes the following inventions.
(1) 0.4 parts by weight of Kanto loam of the 11th class, test powder 1 specified in JIS Z8901 as fine particulate matter, and triolein as a dispersion medium, on the recording and / or reproducing beam incident side surface of the optical information medium. An evaluation dispersion containing 1 part by weight and 10 parts by weight of methoxypropanol as diluent was subjected to the following procedure:
A. The dispersion for evaluation is coated on a polycarbonate substrate for the master by spin coating to prepare a master for transfer of the dispersion for evaluation,
B. Prepare a transfer material made of silicone rubber,
C. The transfer material is pressed against the surface of the prepared master plate to which the evaluation dispersion is applied at a constant load of 4.9 N for 10 seconds to transfer the evaluation dispersion components to the transfer material.
D. The transfer material to which the dispersion component for evaluation has been transferred is pressed against the surface of the polycarbonate substrate for reducing the amount of adhesion with a constant load of 4.9 N for 10 seconds to reduce the amount of the dispersion component for evaluation,
E. FIG. The transfer material with the reduced amount of the dispersion component for evaluation is pressed against another portion of the surface of the polycarbonate substrate for reduction of the adhesion amount with a constant load of 4.9 N for 10 seconds to further increase the amount of the dispersion component for evaluation. Reduce
F. The transfer material in which the adhesion amount of the dispersion component for evaluation has been reduced twice is pressed against the recording and / or reproduction beam incident side surface of the optical information medium with a constant load of 4.9 N for 10 seconds to apply the dispersion component for evaluation. Attach to the surface of the optical information medium
An optical information medium having an area ratio of 6% or less occupied by the evaluation dispersion liquid droplets adhered per unit area of the surface on which the adhesion operation is performed when the adhesion is performed.
[0012]
(2) The optical information medium according to (1), wherein the ratio of the area occupied by the evaluation dispersed droplets adhered per unit area of the surface on which the attaching operation is performed is 4.8% or less.
[0013]
(3) 0.4 parts by weight of Kanto loam, 11th class, test powder 1 specified in JIS Z8901 as fine particles, and triolein as a dispersion medium, on the recording and / or reproduction beam incident side surface of the optical information medium. An evaluation dispersion containing 1 part by weight and 10 parts by weight of methoxypropanol as diluent was subjected to the following procedure:
A. The dispersion for evaluation is coated on a polycarbonate substrate for the master by spin coating to prepare a master for transfer of the dispersion for evaluation,
B. Prepare a transfer material made of silicone rubber,
C. The transfer material is pressed against the surface of the prepared master plate to which the evaluation dispersion is applied at a constant load of 4.9 N for 10 seconds to transfer the evaluation dispersion components to the transfer material.
F. The transfer material into which the dispersion component for evaluation has been transferred is pressed against the recording and / or reproduction beam incident side surface of the optical information medium with a constant load of 4.9 N for 10 seconds to apply the dispersion component for evaluation to the surface of the optical information medium. Attach to
An optical information medium having an area ratio of 4.9% or less occupied by the evaluation dispersion droplets adhered per unit area of the surface on which the adhesion operation is performed when the adhesion is performed.
[0014]
(4) The optical information medium according to any one of (1) to (3), which is used in a system in which the minimum diameter of the recording and / or reproducing beam on the recording and / or reproducing beam incident side surface is 500 μm or less. .
[0015]
(5) At least an information recording layer, a light transmission layer on the information recording layer, and a hard coat layer on the light transmission layer are provided on the support base, and the hard coat layer is on the recording and / or reproduction beam incident side. The optical information medium according to any one of (1) to (4).
[0016]
(6) The optical information medium according to (5), wherein the hard coat layer contains a cured product of a composition containing an active energy ray-curable silicone compound and / or a fluorine compound.
[0017]
(7) The hard coat layer further has a surface thin layer made of a cured product of a composition mainly containing an active energy ray-curable silicone compound and / or fluorine compound, (5) or (6). An optical information medium according to claim 1.
[0018]
(8) The optical information medium according to any one of (5) to (7), wherein the total thickness of the light transmitting layer and the hard coat layer is 70 to 150 μm.
[0019]
(9) The optical information medium according to any one of (1) to (8), which is used for a recording / reproducing system using a blue laser beam.
[0020]
The present invention includes the following inventions.
(10) The optical information medium according to any one of (1) to (3), which is used for a system in which the minimum diameter of the recording and / or reproducing beam on the recording and / or reproducing beam incident side surface exceeds 500 μm.
[0021]
(11) having at least an information recording layer and a protective layer on the information recording layer on one surface of the light-transmitting support base, and having a light-transmitting hard coat layer on the other surface of the support base; The optical information medium according to (10), wherein the hard coat layer is on a recording and / or reproducing beam incident side.
[0022]
(12) The optical information medium according to any one of (10) and (11), which is used for a recording / reproducing system using a blue laser beam.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
The optical information medium of the present invention has very excellent antifouling property on the recording and / or reproducing beam incident side surface, and is very suitable for a system in which the minimum diameter of the recording and / or reproducing beam on the surface is 500 μm or less. However, it is also suitably used for a system in which the minimum diameter of the recording and / or reproducing beam on the surface exceeds 500 μm.
[0024]
1. An optical information medium in which the minimum diameter of the recording / reproducing beam on the recording / reproducing beam incident side surface is 500 μm or less:
First, an optical information medium in which the minimum diameter of the recording / reproducing beam on the recording / reproducing beam incident side surface is 500 μm or less will be described. In such an optical information medium, when a fingerprint or the like adheres to the recording / reproducing beam incident side surface during use, the disadvantage that the error rate deteriorates is particularly likely to occur. When a large amount of fingerprints or the like adhere, not only the error rate is deteriorated, but also the tracking is broken.
[0025]
FIG. 1 shows a configuration example of the optical information medium of the present invention. This optical information medium is a recording medium, having a recording layer (4) as an information recording layer on a relatively rigid support base (20), and a light transmitting layer (7) on the recording layer (4). And a light-transmitting hard coat layer (8) on the light-transmitting layer (7). The hard coat layer (8) is on the recording / reproducing beam incident side, and a laser beam for recording or reproduction enters the recording layer (4) through the hard coat layer (8) and the light transmitting layer (7). The thickness of the light transmitting layer (7) including the hard coat layer (8) is preferably 30 to 300 µm, more preferably 70 to 150 µm. Such an optical information medium has a hardness of B or more in a pencil hardness test on the hard coat layer (8) side.
[0026]
The effect of fingerprint attachment on the recording / reproducing characteristics depends on the diameter of the laser beam on the laser beam incident side surface of the medium (minimum diameter if the beam cross section is elliptical), and if this diameter is small, error correction is impossible. The effect becomes large, such as occurrence of a continuous error. According to the study of the present inventors, when the diameter of the laser beam on the incident side surface of the medium is 500 μm or less, particularly 300 μm or less, adverse effects on the recording / reproducing characteristics when a fingerprint adheres when handling the medium. Was remarkable. The diameter of the laser beam on the laser beam incident side surface of the medium is represented by t as the thickness of the light transmitting layer (7) and n as the refractive index of the light transmitting layer (7) in FIG. When the numerical aperture of the objective lens is NA,
Laser beam diameter = 2t · tan ｛sin ^-1 (NA / n)｝
Is represented by However, since the difference in the refractive index between the hard coat layer (8) and the light transmitting layer (7) is small and the thickness of the hard coat layer (8) is smaller than the thickness of the light transmitting layer (7), The hard coat layer has been ignored. For example, in the Blu-ray Disc, when t = 100 μm, NA = 0.85, and n = 1.55, the value of the diameter of the laser beam on the incident surface of the disk is about 130 μm.
[0027]
The present invention is applicable regardless of the type of the recording layer. That is, for example, the present invention can be applied to a phase change recording medium, a pit forming type recording medium, and a magneto-optical recording medium. In general, a dielectric layer or a reflective layer is provided on at least one side of the recording layer for the purpose of protecting the recording layer or providing an optical effect, but is not shown in FIG. Further, the present invention is not limited to the recordable type as shown in the figure, but is also applicable to a read-only type. In this case, a pit row is formed integrally with the support base (20), and the reflective layer (metal layer or dielectric multilayer film) covering the pit row forms an information recording layer.
[0028]
An optical information medium in the case of the phase change type recording medium of the present invention will be described.
FIG. 2 is a schematic sectional view of an example of the optical disk of the present invention. In FIG. 2, the optical disc has a reflective layer (3), a second dielectric layer (52), and a phase change layer on a surface of a support base (20) on which fine irregularities such as information pits and pregrooves are formed. It has a recording material layer (4) and a first dielectric layer (51) in this order, has a light transmitting layer (7) on the first dielectric layer (51), and has a light transmitting layer (7) on the light transmitting layer (7). It has a hard coat layer (8). In this example, the reflective layer (3), the second dielectric layer (52), the phase change recording material layer (4), and the first dielectric layer (51) constitute an information recording layer. The optical disk (1) is used so that a laser beam for recording or reproduction enters through the hard coat layer (8) and the light transmitting layer (7).
[0029]
The support base (20) has a thickness of 0.3 to 1.6 mm, preferably 0.5 to 1.3 mm, and has information pits and pre-grooves on the surface on which the recording layer (4) is formed. Are formed.
[0030]
The support base (20) does not need to be optically transparent because it is used so that laser light is incident from the light transmitting layer (7) side as described above. Acrylic resins such as polymethyl methacrylate (PMMA) and various plastic materials such as polyolefin resins can be used. Alternatively, glass, ceramics, metal, or the like may be used. In the case where a plastic material is used, the concavo-convex pattern is often formed by injection molding. In the case of using a material other than a plastic material, the pattern is formed by a photopolymer method (2P method).
[0031]
On the supporting substrate (20), a reflective layer (3) is usually formed by a sputtering method. As a material of the reflection layer, a metal element, a metalloid element, a semiconductor element, or a compound thereof is used alone or in combination. Specifically, the material may be selected from well-known reflective layer materials such as Au, Ag, Cu, Al, and Pd. The reflection layer is preferably formed as a thin film having a thickness of 20 to 200 nm.
[0032]
The second dielectric layer (52), the phase-change recording material layer (4), and the first dielectric layer (51) are provided on the reflective layer (3) or directly on the support base (20) when no reflective layer is provided. ) Are formed in this order by a sputtering method.
[0033]
The phase-change recording material layer (4) is reversibly changed between a crystalline state and an amorphous state by laser light irradiation, and is formed of a material having optical characteristics different between the two states. Examples include Ge-Sb-Te, In-Sb-Te, Sn-Se-Te, Ge-Te-Sn, In-Se-Tl, and In-Sb-Te. Further, a trace amount of at least one of metals selected from Co, Pt, Pd, Au, Ag, Ir, Nb, Ta, V, W, Ti, Cr, Zr, Bi, In and the like is added to these materials. A small amount of a reducing gas such as nitrogen may be added. The thickness of the recording material layer (4) is not particularly limited and is, for example, about 3 to 50 nm.
[0034]
The second dielectric layer (52) and the first dielectric layer (51) are formed on the upper and lower surfaces of the recording material layer (4) with the two layers interposed therebetween. The second dielectric layer (52) and the first dielectric layer (51) have a function of mechanical and chemical protection of the recording material layer (4) and a function of an interference layer for adjusting optical characteristics. Each of the second dielectric layer (52) and the first dielectric layer (51) may be composed of a single layer or a plurality of layers.
[0035]
The second dielectric layer (52) and the first dielectric layer (51) are made of Si, Zn, Al, Ta, Ti, Co, Zr, Pb, Ag, Zn, Sn, Ca, Ce, V, Cu, It is preferable to be formed from an oxide, a nitride, a sulfide, a fluoride, or a composite thereof containing at least one of metals selected from Fe and Mg. The extinction coefficient k of each of the second dielectric layer (52) and the first dielectric layer (51) is preferably 0.1 or less.
[0036]
The thickness of the second dielectric layer (52) is not particularly limited, and is preferably, for example, about 20 to 150 nm. The thickness of the first dielectric layer (51) is not particularly limited, and is preferably, for example, about 20 to 200 nm. By selecting the thickness of both dielectric layers (52) and (51) within such a range, the reflection can be adjusted.
[0037]
The light transmitting layer (7) is formed on the first dielectric layer (51) using an active energy ray-curable material or using a light transmitting sheet such as a polycarbonate sheet.
[0038]
The active energy ray-curable material used for the light transmitting layer (7) is an optically curable material, provided that it is optically transparent, has low optical absorption and reflection in the laser wavelength range used, and has low birefringence. Select from materials and electron beam curable materials.
[0039]
Specifically, it is preferable to be composed of an ultraviolet (electron beam) curable compound or a composition for polymerization thereof. Examples of such compounds include ester compounds of acrylic acid or methacrylic acid, acrylic double bonds such as epoxy acrylate and urethane acrylate, allyl double bonds such as diallyl phthalate, and unsaturated double bonds such as maleic acid derivatives. Monomers, oligomers and polymers containing or introducing into the molecule a group which is crosslinked or polymerized by ultraviolet irradiation such as bonding may be mentioned. These are preferably polyfunctional, particularly trifunctional or more, and may be used alone or in combination of two or more. Moreover, you may use a monofunctional thing as needed.
[0040]
A compound having a molecular weight of less than 2,000 is suitable as an ultraviolet-curable monomer, and a compound having a molecular weight of 2,000 to 10,000 is suitable as an oligomer. These also include styrene, ethyl acrylate, ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol methacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, and the like, with particularly preferred ones. Examples thereof include pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane di (meth) acrylate, and (meth) acrylate of phenol ethylene oxide adduct. . In addition, examples of UV-curable oligomers include oligoester acrylates and modified acrylics of urethane elastomers.
[0041]
The ultraviolet (electron beam) curable material may include a known photopolymerization initiator. The photopolymerization initiator is not particularly required when an electron beam is used as an active energy ray, but is required when an ultraviolet ray is used. The photopolymerization initiator may be appropriately selected from ordinary ones such as acetophenone, benzoin, benzophenone, and thioxanthone. Among the photopolymerization initiators, examples of the photoradical initiator include Darocur 1173, Irgacure 651, Irgacure 184, and Irgacure 907 (all manufactured by Ciba Specialty Chemicals). The content of the photopolymerization initiator is, for example, about 0.5 to 5% by weight based on the ultraviolet (electron beam) curable component.
[0042]
Further, as the ultraviolet curable material, a composition containing an epoxy compound and a cationic photopolymerization catalyst is also preferably used. As the epoxy compound, an alicyclic epoxy compound is preferable, and in particular, a compound having two or more epoxy groups in a molecule is preferable. Examples of the alicyclic epoxy compound include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, bis- (3,4-epoxycyclohexylmethyl) adipate, bis- (3,4-epoxycyclohexyl) adipate, One or more of 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (2,3-epoxycyclopentyl) ether, vinylcyclohexene dioxide and the like are preferable. . The epoxy equivalent of the alicyclic epoxy compound is not particularly limited, but is preferably from 60 to 300, particularly preferably from 100 to 200, since good curability is obtained.
[0043]
Any known photocationic polymerization catalyst may be used, and there is no particular limitation. For example, a complex of at least one metal fluoroborate and boron trifluoride, a metal salt of bis (perfluoroalkylsulfonyl) methane, an aryldiazonium compound, an aromatic onium salt of a Group 6A element, an aromatic onium salt of a Group 5A element, Use is made of a dicarbonyl chelate of a 3A to 5A element, a thiopyrylium salt, a 6A element having an MF6 anion (M is P, As or Sb), a triarylsulfonium complex salt, an aromatic iodonium complex salt, an aromatic sulfonium complex salt or the like. In particular, it is preferable to use at least one of a polyarylsulfonium complex salt, an aromatic sulfonium salt or an iodonium salt of a halogen-containing complex ion, an aromatic onium salt of a Group 3A element, a Group 5A element and a Group 6A element. The content of the cationic photopolymerization catalyst is, for example, about 0.5 to 5% by weight based on the ultraviolet curable component.
[0044]
As the active energy ray-curable material used for the light transmitting layer, a material having a viscosity (25 ° C.) of 1,000 to 10,000 cp is preferable.
[0045]
In forming the light transmitting layer (7), the active energy ray-curable material may be applied on the first dielectric layer (51) by a spin coating method. The thickness of the light transmitting layer (7) is, for example, about 10 to 300 μm after curing, preferably 20 to 200 μm, particularly 70 to 150 μm, and more particularly 75 to 150 μm. It may be cured by irradiating ultraviolet rays. The ultraviolet irradiation at this time may be performed a plurality of times. Further, the application operation of the active energy ray-curable material may be performed in a plurality of times, and ultraviolet irradiation may be performed after each application operation. By performing the ultraviolet irradiation in a plurality of times and curing the resin stepwise, it is possible to reduce the stress due to the curing shrinkage that accumulates on the disk at one time, and finally the stress that accumulates on the disk decreases. As a result, even if the thickness of the light transmitting layer (7) is as thick as described above, it is preferable because a disk having excellent mechanical properties can be produced.
[0046]
Alternatively, in the present invention, the light transmitting layer can be formed using a light transmitting resin sheet. In this case, the same active energy ray curable material as that for the light transmitting layer is applied on the first dielectric layer (51) to form an uncured resin material layer. A light-transmitting sheet as a light-transmitting layer (7) is placed on the uncured resin material layer, and thereafter, the resin material layer is cured by irradiating active energy rays such as ultraviolet rays. The sheet is bonded to form a light transmitting layer (7). The active energy ray-curable material used for the resin material layer preferably has a viscosity of 3 to 500 cp (at 25 ° C.). The application of the resin material layer is preferably performed by a spin coating method. The thickness of the resin material layer may be, for example, about 1 to 50 μm after curing.
[0047]
As the light transmitting sheet, for example, a polycarbonate sheet having a desired thickness selected from 50 to 300 μm is used. More specifically, the light transmitting layer (7) is formed by placing a polycarbonate sheet having a desired thickness on an uncured resin material layer in a vacuum (0.1 atm or less). The atmosphere is returned to the atmospheric pressure, and the resin material layer is cured by irradiating ultraviolet rays.
[0048]
An active energy ray-curable composition for a hard coat layer is applied on the light transmitting layer (7), and the composition is cured by irradiating an active energy ray such as an ultraviolet ray, an electron beam, or visible light to form a hard coat. Form a layer (8). The composition for a hard coat layer includes (A) inorganic fine particles having an average particle diameter of 100 nm or less, (B) an active energy ray-curable silicone-based compound and / or a fluorine-based compound, and (C) a component other than the component (B). It preferably contains an active energy ray-curable compound. Each of these components will be described.
[0049]
The active energy ray-curable compound (C) contained in the composition for a hard coat layer is particularly preferably a compound having at least one active group selected from a (meth) acryloyl group, a vinyl group and a mercapto group. The structure is not limited. The active energy ray-curable compound preferably contains a polyfunctional monomer or oligomer containing two or more, preferably three or more polymerizable groups in one molecule in order to obtain sufficient hardness as a hard coat. . If too many polyfunctional monomers or oligomers are used, the hardness of the hard coat increases, but the curing shrinkage increases and the warpage of the disk increases, so care must be taken.
[0050]
Among such active energy ray-curable compounds (C), examples of the compound having a (meth) acryloyl group include 1,6-hexanediol di (meth) acrylate, triethylene glycol di (meth) acrylate, and ethylene. Oxide-modified bisphenol A di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol tri (meth) acrylate ) Acrylate, 3- (meth) acryloyloxyglycerin mono (meth) acrylate, urethane acrylate, epoxy acrylate, ester acrylate, etc. The present invention is not limited to.
[0051]
Examples of the compound having a vinyl group include ethylene glycol divinyl ether, pentaerythritol divinyl ether, 1,6-hexanediol divinyl ether, trimethylolpropane divinyl ether, ethylene oxide-modified hydroquinone divinyl ether, and ethylene oxide-modified bisphenol A divinyl ether. Examples include vinyl ether, pentaerythritol trivinyl ether, dipentaerythritol hexavinyl ether, and ditrimethylolpropane polyvinyl ether, but are not necessarily limited thereto.
[0052]
Examples of the compound having a mercapto group include, for example, ethylene glycol bis (thioglycolate), ethylene glycol bis (3-mercaptopropionate), trimethylolpropane tris (thioglycolate), and trimethylolpropane tris (3-glycolate). Mercaptopropionate), pentaerythritol tetrakis (mercaptoacetate), pentaerythritol tetrakis (thioglycolate), pentaerythritol tetrakis (3-mercaptopropionate), and the like, but are not necessarily limited thereto.
[0053]
As the active energy ray-curable compound (C) contained in the composition for a hard coat layer, only one type may be used, or two or more types may be used in combination.
[0054]
The inorganic fine particles (A) contained in the composition for a hard coat layer have an average particle size of 100 nm or less, preferably 20 nm or less in order to secure transparency of the hard coat layer. The average particle diameter of the inorganic fine particles (A) is preferably 5 nm or more due to restrictions on the production of the colloid solution.
[0055]
(A) The inorganic fine particles are, for example, metal (or metalloid) oxide fine particles or metal (or metalloid) sulfide fine particles. Examples of the metal or semimetal of the inorganic fine particles include Si, Ti, Al, Zn, Zr, In, Sn, and Sb. Further, in addition to oxides and sulfides, Se compounds, Te compounds, nitrides, and carbides can also be used. Examples of the inorganic fine particles include fine particles of silica, alumina, zirconia, titania, and the like, and silica fine particles are preferable. By adding such inorganic fine particles to the hard coat agent composition, the wear resistance of the hard coat layer can be further improved.
[0056]
Among the silica fine particles, those finely modified with a hydrolyzable silane compound having an active energy ray-reactive group are preferably used. Such reactive silica fine particles cause a crosslinking reaction by irradiation with active energy rays when the hard coat is cured, and are fixed in the polymer matrix. Examples of such reactive silica fine particles include reactive silica particles described in JP-A-9-100111, which can be preferably used in the present invention.
[0057]
(B) The active energy ray-curable silicone compound and / or fluorine compound is used for imparting water repellency and / or lubricity to the surface of the hard coat layer. Examples of the substituent for imparting water repellency and / or lubricity include a silicone-based substituent and / or a fluorine-based substituent. The active energy ray-polymerizable reactive group includes an active energy ray radically polymerizable reactive group such as a (meth) acryloyl group, a vinyl group and a mercapto group, and an active energy ray cation such as a cyclic ether group and a vinyl ether group. And a polymerizable reactive group. A silicone compound having such a radical polymerizable reactive group or a cationic polymerizable reactive group, or a fluorine compound can be used.
[0058]
As the silicone-based compound, a compound having a site having a silicone-based substituent and at least one reactive group selected from a (meth) acryloyl group, a vinyl group, a mercapto group, a cyclic ether group, and a vinyl ether group And more specifically, for example, compounds represented by the following formulas (1) to (3), but are not necessarily limited thereto.
[0059]
R- [Si (CH ₃ ) ₂ O] n-R (1)
R- [Si (CH ₃ ) ₂ O] n-Si (CH ₃ ) ₃ (2)
(CH ₃ ) ₃ SiO- [Si (CH ₃ ) ₂ 0] n- [Si (CH ₃ ) (R) O] m-Si (CH ₃ ) ₃ (3)
Here, R is a substituent containing at least one reactive group selected from a (meth) acryloyl group, a vinyl group, a mercapto group, a cyclic ether group and a vinyl ether group, and n and m each represent a degree of polymerization. And n is 5 to 1000 and m is 2 to 100.
[0060]
Examples of the fluorine-based compound include fluorine-containing (meth) acrylate compounds, and specifically, for example, 2,2,3,3,3-pentafluoropropyl (meth) acrylate, 2,2,3,3- Tetrafluoropropyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, 3- (perfluoro-5-methylhexyl) -2- Hydroxypropyl (meth) acrylate, 2- (perfluorooctyl) ethyl acrylate, 3-perfluorooctyl-2-hydroxypropyl (meth) acrylate, 2- (perfluorodecyl) ethyl (meth) acrylate, 2- (perfluoro -9-methyloctyl) ethyl (meth) acrylate, Fluorinated acrylates such as fluoro-7-methyloctyl) ethyl (meth) acrylate, 2- (perfluoro-9-methyldecyl) ethyl (meth) acrylate, and 1H, 1H, 9H-hexadecafluorononyl (meth) acrylate However, it is not necessarily limited to these. For example, a perfluoropolyether into which a (meth) acrylate group has been introduced can also be preferably used. Alternatively, a fluorine-based compound having a vinyl group or a mercapto group instead of the (meth) acrylate group can be preferably used. Specific examples thereof include diacrylate of Fombrin Z DOL (alcohol-modified perfluoropolyether (manufactured by Ausimont)), Fluorite ART3, and Fluorite ART4 (Kyoeisha Chemical).
[0061]
Examples of the fluorine-based compound include a compound having a site having a fluorine-containing substituent and at least one reactive group selected from a cyclic ether group and a vinyl ether group. Specifically, 3- (1H, 1H-perfluorooctyloxy) -1,2-epoxypropane, 3- (1H, 1H-perfluorononyloxy) -1,2-epoxypropane, 3- (1H, 1H-perfluorodecyloxy) -1,2-epoxypropane, 3- (1H, 1H-perfluoroundecyloxy) -1,2-epoxypropane, 3- (1H, 1H-perfluorotetradecyloxy) -1 , 2-epoxypropane, 3- (1H, 1H-perfluorohexadecyloxy) -1,2-epoxypropane, 1H, 1H, 6H, 6H-perfluoro-1,6-hexanediol diglycidyl ether, 1H, 1H, 8H, 8H-perfluoro-1,8-octanediol diglycidyl ether, 1H, 1H, 9H, 9H-perfluoro-1, -Nonanediol diglycidyl ether, 1H, 1H, 10H, 10H-perfluoro-1,10-decanediol diglycidyl ether, 1H, 1H, 12H, 12H-perfluoro-1,12-dodecanediol diglycidyl ether, Fombrin Examples include, but are not necessarily limited to, diglycidyl ethers of Z DOL (alcohol-modified perfluoropolyether (manufactured by Audimont)). For example, a compound having an alicyclic epoxy group such as a 3,4-epoxycyclohexyl group or a vinyl ether group as a reactive group can also be preferably used. In addition, MODIPER F220, F600, F2020, F3035 (manufactured by NOF Corporation) and the like can be used as the fluorine-based block copolymer.
[0062]
In the present invention, the composition for a hard coat layer comprises (A) 5% by weight or more and 80% by weight or less of inorganic fine particles, based on the total of (A), (B) and (C); It is preferable to contain 0.001% by weight or more and 10% by weight or less of a fluorine-based compound and / or a fluorine-based compound and 10% by weight or more and 94.999% by weight or less of (C) an active energy ray-curable compound. If the inorganic fine particles (A) are contained in an amount of more than 80% by weight, the film strength of the hard coat layer tends to be weak, while if less than 5% by weight, the effect of improving the wear resistance of the hard coat layer is weak. When the silicone-based compound and / or fluorine-based compound (B) is contained in an amount of more than 10% by weight, the lubricity is improved but the hardness of the hard coat layer tends to be low. Poor performance improvement effect. More preferably, the compounding ratio in the composition for a hard coat layer is (A) 10% by weight or more and 60% by weight or less of inorganic fine particles, and (B) silicone, based on the total of (A), (B) and (C). 0.001% by weight or more and 10% by weight or less of the active compound and / or fluorine type compound, and 30% by weight or more and 89.999% by weight or less of the (C) active energy ray-curable compound. In particular, when the silicone compound and / or fluorine compound (B) is contained in an amount of 0.01% by weight or more and 3% by weight or less, it is easy to obtain an optical information medium conforming to the present invention, and 0.05% by weight or more and 1% by weight. It is most preferable to include the following.
[0063]
The composition for a hard coat layer may include a known photopolymerization initiator as described above. The photopolymerization initiator is not particularly required when an electron beam is used as an active energy ray, but is required when an ultraviolet ray is used. The content of the photopolymerization initiator is, for example, about 0.5 to 5% by weight based on the total of the above (A), (B) and (C) in the composition for a hard coat layer.
[0064]
Further, the composition for the hard coat layer may further contain a non-polymerizable diluting solvent, an organic filler, a polymerization inhibitor, an antioxidant, an ultraviolet absorber, a light stabilizer, an antifoaming agent, a leveling agent, a pigment, if necessary. , Silicon compounds and the like.
[0065]
In the present invention, the composition for a hard coat layer is applied on the light transmitting layer (7) to form an uncured hard coat layer, and thereafter the active layer is irradiated with active energy rays to cure the uncured layer. And a hard coat layer (8). The application method is not limited, and various application methods such as a spin coating method, a dip coating method, and a gravure coating method may be used. Alternatively, when a light transmissive sheet is used as the light transmissive layer (7), a hard coat layer (8) is previously formed on the long light transmissive sheet raw material in the same manner as described above, and After punching out the web into a disk shape, the resin material layer may be cured by placing it on the uncured resin material layer as described above.
[0066]
When the hard coat layer composition contains a non-reactive diluted organic solvent, after applying the hard coat layer composition to form an uncured hard coat layer, the non-reactive organic solvent After removal by heating and drying, the uncured layer is cured by irradiation with active energy rays to form a hard coat layer (8). By applying the composition for a hard coat layer using a diluted organic solvent, and removing the organic solvent by heating and drying, the reactive silicone is more likely to gather near the surface of the uncured hard coat layer, and after the curing, Since more silicone exists near the surface of the hard coat layer (8), a greater lubricity improving effect is easily obtained. The temperature for the heating and drying at this time is preferably, for example, a temperature of 40 ° C or more and 100 ° C or less. The heating and drying time is, for example, 30 seconds or more and 8 minutes or less, preferably 1 minute or more and 5 minutes or less, and more preferably 3 minutes or more and 5 minutes or less. The non-reactive diluting organic solvent is not particularly limited, but propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, isopropyl alcohol and the like are used. As the active energy ray, an appropriate one may be selected from active energy rays such as ultraviolet rays, an electron beam, and visible light, and preferably, an ultraviolet ray or an electron beam is used. The thickness of the hard coat (8) after curing is about 0.5 to 5 μm.
[0067]
In the present invention, as exemplified in FIG. 3, the optical information medium further comprises an active energy ray-curable silicone-based compound and / or a fluorine-based compound as a main component on the hard coat layer (8). It may have a surface thin layer (9) made of an applied / cured product. Examples of the active energy ray-curable silicone compound and / or fluorine compound for the surface thin layer (9) include the silicone compound and / or fluorine compound (B) for the hard coat layer (8) described above. Therefore, only one type may be used, or two or more types may be used in combination. The thickness of the surface thin layer (9) is, for example, 1 nm to 100 nm. The surface thin layer (9) further improves the antifouling property. When such a surface thin layer (9) is formed, the composition for the hard coat layer may or may not contain the silicone compound and / or the fluorine compound (B). .
[0068]
As described above, a phase-change optical recording disk illustrated in FIG. 2 or 3 is obtained as an optical information medium in which the minimum diameter of the recording / reproducing beam on the recording / reproducing beam incident side surface is 500 μm or less.
[0069]
2. An optical information medium in which the minimum diameter of the recording / reproducing beam on the recording / reproducing beam incident side surface exceeds 500 μm:
Next, an optical information medium in which the minimum diameter of the recording / reproducing beam on the recording / reproducing beam incident side surface exceeds 500 μm will be described. Even in such an optical information medium, when a fingerprint or the like adheres to the recording / reproducing beam incident side surface during use, the inconvenience that the error rate deteriorates easily occurs. When a large amount of fingerprints and the like adhere, not only does the error rate worsen, but even tracking becomes impossible.
[0070]
FIG. 4 shows a configuration example of the optical information medium of the present invention. The medium illustrated in FIG. 4 has an information recording layer (4) on one surface of a light-transmitting support substrate (20) and a protective layer (6) on the information recording layer (4). A light-transmitting hard coat layer (8) is provided on the other surface of (20). The hard coat layer (8) is on the recording / reproducing beam incident side, and a laser beam for recording or reproduction is incident on the recording layer (4) through the hard coat layer (8) and the support base (20).
[0071]
FIG. 5 shows another configuration example of the optical information medium of the present invention. The optical recording medium illustrated in FIG. 5 has an organic dye layer (4) as an information recording layer on one surface of a light-transmitting support substrate (20), and a reflective layer (3) on the dye layer (4). And a support base (21) bonded on the reflective layer (3) via an adhesive layer (61), and a light-transmitting hard coat layer (8) on the other surface of the support base (20). The hard coat layer (8) is on the recording / reproducing beam incident side.
[0072]
Various optical recording media such as a read-only DVD-ROM, a write-once DVD-R, and a rewritable DVD-RAM have been commercialized. As read-only DVDs, there are DVD-Video, DVD-ROM, and the like. In these optical recording media, when forming a light-transmitting substrate, irregularities called pits on which information signals are recorded are formed. A metal reflective layer of Al or the like is formed thereon, and a protective layer is further formed. Another support substrate is bonded on the protective layer via the adhesive layer (61), and the final optical recording medium is obtained.
[0073]
A light-transmitting substrate is used as the support base (20). Conventionally, the light-transmitting supporting substrate (20) is formed by injection molding a polycarbonate resin and forming various information, for example, pre-pits and pre-grooves on the surface thereof, but the material used is not limited thereto. Resins such as polyolefin resins are also preferably used. Alternatively, it can be obtained by forming pre-pits or pre-grooves on a glass plate by the 2P method.
[0074]
An organic dye dissolved in a solvent is applied on the support base (20) by a spin coating method, and dried to form an organic dye layer (4) having a desired thickness. The organic dye is selected from various cyanine dyes, azo dyes, phthalocyanine dyes, and the like. As a method for forming the dye layer, a spray method, a screen printing method, a vapor deposition method, or the like can be applied in addition to the spin coating method, and the film thickness to be formed is appropriately selected depending on the dye to be used.
[0075]
When applying the spin coating method, the dye component is dissolved in a solvent and used as an organic dye solution.As the solvent, a solvent that can sufficiently dissolve the dye and does not adversely affect the permeable substrate is selected. Used. The concentration is preferably about 0.01 to 10% by weight.
[0076]
Examples of the solvent include alcohols such as methanol, ethanol, isopropyl alcohol, octafluoropentanol, allyl alcohol, methyl cellosolve, ethyl cellosolve, and tetrafluoropropanol; hexane, heptane, octane, decane, cyclohexane, methylcyclohexane, and ethylcyclohexane. Aliphatic or alicyclic hydrocarbon solvents such as dimethylcyclohexane; aromatic hydrocarbon solvents such as toluene, xylene and benzene; halogenated hydrocarbon solvents such as carbon tetrachloride, chloroform, tetrachloroethane and dibromoethane; diethyl Ether solvents such as ether, dibutyl ether, diisopropyl ether and dioxane; ketone solvents such as 3-hydroxy-3-methyl-2-butanone; ethyl acetate, methyl lactate Ester-based solvents; water and the like, can be used from among these does not attack the substrate material. These may be used alone or as a mixture of two or more.
[0077]
The thickness of the organic dye layer is not particularly limited, but is preferably about 10 to 300 nm, particularly about 60 to 250 nm.
[0078]
The reflection layer (3) is provided on the organic dye layer (4). As the material of the reflection layer, a material having a sufficiently high reflectance at the wavelength of the reproduction light, for example, an element such as Au, Ag, Cu, Al, Ni, Pd, Cr, or Pt is used alone or as an alloy. In addition to the above, the following may be included. For example, Mg, Se, Hf, V, Nb, Ru, W, Mn, Re, Fe, Co, Rh, Ir, Zn, Cd, Ga, In, Si, Ge, Te, Pb, Po, Sn, Bi, etc. Metals and metalloids can be mentioned.
[0079]
The formation of the reflective layer includes, for example, a sputtering method, an ion plating method, a chemical vapor deposition method, and a vacuum vapor deposition method, but is not limited thereto. Further, a known inorganic or organic intermediate layer or adhesive layer may be provided on the substrate or below the reflective layer to improve the reflectance and the recording characteristics. The thickness of the reflective layer is not particularly limited, but is preferably about 10 to 300 nm, and particularly about 80 to 200 nm.
[0080]
On the reflective layer (3), a support base (21) is usually bonded via an adhesive layer (61). As the supporting base (21), the same as the supporting base (20) is used. The material of the adhesive layer (61) is not particularly limited as long as the two substrates (21) and (20) can be bonded and the reflective layer is protected from external force. Can be used. Examples of the organic substance include a thermoplastic resin, a thermosetting resin, and a UV curable resin. Further, as the inorganic substance, SiO 2 ₂ , SiN ₄ , MgF ₂ , SnO ₂ And the like. A thermoplastic resin, a thermosetting resin, or the like can be formed by dissolving in a suitable solvent, applying a coating solution, and drying. The UV-curable resin can be formed by preparing a coating solution as it is or by dissolving it in an appropriate solvent, applying the coating solution, and irradiating with UV light to cure the coating solution. As the UV-curable resin, for example, acrylate resins such as urethane acrylate, epoxy acrylate, and polyester acrylate can be used. These materials may be used alone or as a mixture, or may be used not only in one layer but also in a multilayer film.
[0081]
As a method for forming the adhesive layer (61), a coating method such as a spin coating method or a casting method, a method such as a sputtering method or a chemical vapor deposition method is used in the same manner as the recording layer.
[0082]
The adhesive used for bonding is a hot-melt adhesive, an ultraviolet-curable adhesive, a heat-curable adhesive, a pressure-sensitive adhesive, or the like, and a method suitable for each, such as a roll coater method or a screen, is used. A printing method, a spin coating method, etc. may be mentioned. In the case of a DVD-R, a screen printing method or a spin coating method is used, using an ultraviolet curing adhesive, judging comprehensively from workability, productivity, disk characteristics and the like. Can be
[0083]
On the other hand, a light-transmitting hard coat layer (8) is formed on the other surface of the support base (20). The material and formation of the hard coat layer (8) are as follows. It is the same as described in. The hard coat layer (8) is on the recording / reproducing beam incident side. As the recording / reproducing beam, a laser beam having a wavelength of 650 nm or 660 nm is used. Further, a blue laser beam is used.
[0084]
As described above, the DVD-R illustrated in FIG. 5 is obtained as an optical information medium in which the minimum diameter of the recording / reproducing beam on the recording / reproducing beam incident side surface exceeds 500 μm.
[0085]
The optical information medium of the present invention described above has the following evaluation liquid dispersion adhered to the recording and / or reproduction beam incident side surface by the following procedure. The ratio of the area occupied by the attached dispersion droplets for evaluation is 6% or less.
[0086]
The dispersion for evaluation was 0.4 parts by weight of Kanto loam of 11th class of test powder 1 as specified in JIS Z8901 as fine particles, 1 part by weight of triolein as a dispersion medium, and 10 parts by weight of methoxypropanol as a diluent. Including parts. This dispersion for evaluation is an artificial fingerprint liquid disclosed in WO03 / 29382A1. Triolein is one of the sebum constituents. The dispersion medium refers to only a liquid component remaining as a pseudo-fingerprint component after being transferred to the surface of the optical information medium to be evaluated, and a diluent from which most or all is finally distilled off after transfer. Distinguish. By constructing a heterogeneous system in which Kanto loam, which is a suitable insoluble component, is dispersed in triolein, which is a liquid component contained in an actual fingerprint, the dispersion for evaluation is as close as possible to the actual fingerprint. It has properties.
[0087]
The dispersion for evaluation is applied by the following fixed procedure.
A. The dispersion for evaluation is coated on a polycarbonate substrate for the master by spin coating to prepare a master for transfer of the dispersion for evaluation. Spin coating is performed by dropping 1 mL of the dispersion for evaluation onto a substrate, rotating the substrate at 500 rpm for 3 seconds, and immediately rotating the substrate at 250 rpm for 3 seconds. Since methoxypropanol is used as the diluent, the coatability is good. The substrate is heated at 60 ° C. for 3 minutes to remove methoxypropanol, which becomes unnecessary thereafter.
[0088]
B. Prepare a transfer material made of silicone rubber. No. 1. The smaller end face (diameter 12 mm) of the silicone rubber stopper 1 is uniformly roughened with # 240 abrasive paper. The abrasive paper of # 240 has the same performance as AA240 abrasive paper specified in JIS R6251 or JIS R6252.
[0089]
C. The roughened end surface of the transfer material is pressed with a constant load of 4.9 N for 10 seconds against the surface of the prepared master plate on which the evaluation dispersion is applied, and the evaluation dispersion component is transferred to the end surface of the transfer material. .
[0090]
D. The end surface of the transfer material to which the dispersion component for evaluation has been transferred is pressed against the smooth surface of the adhesion-reducing polycarbonate substrate with a constant load of 4.9 N for 10 seconds to reduce the adhesion amount of the dispersion component for evaluation. The same type of polycarbonate substrate as the original plate is used as the polycarbonate substrate for reducing the amount of adhesion.
[0091]
E. FIG. The end face of the transfer material having the reduced amount of the dispersion component for evaluation is pressed against another portion of the surface of the polycarbonate substrate for reduction of the amount of adhesion with a constant load of 4.9 N for 10 seconds to adhere the dispersion component for evaluation. Further reduce the volume.
[0092]
F. The end face of the transfer material in which the adhesion amount of the dispersion component for evaluation was reduced twice was placed at a position of about 4.9 N at a position about 40 mm in the radial direction from the center of the recording and / or reproduction beam incidence side surface of the optical information medium disk. Is pressed for 10 seconds under a constant load to adhere the dispersion component for evaluation.
[0093]
Here, the adhesion operation of performing the dispersion amount reduction operations D and E twice by the above procedure is referred to as adhesion level 3 for convenience. The adhesion operation for performing the dispersion amount adhesion operation D once is referred to as adhesion level 2 for convenience. The adhesion operation in which the dispersion amount reduction operations D and E are not performed is referred to as adhesion level 1 for convenience. As the level increases from the adhesion level 1 to the adhesion level 3, the amount of the dispersion liquid for evaluation transferred to the surface of the optical disk to be evaluated decreases. Attachment level 3 is considered to be a fingerprint attachment level that can occur with a user's normal disc use. Attachment level 1 is considered to be a large amount of fingerprint attachment levels that would not occur with a user's normal disc use.
[0094]
In the optical information medium of the present invention, when the dispersion liquid for evaluation is adhered to the recording / reproducing beam incident side surface at the adhesion level 3 above, the dispersion liquid droplet for evaluation adhered per unit area of the surface on which the adhesion operation was performed. Is less than 6%. If the area ratio at the adhesion level 3 exceeds 6%, the error rate characteristic during reproduction deteriorates when a fingerprint adheres to the recording / reproduction beam incident side surface after pre-recording. Therefore, in any of the read-only optical information medium, the optical information medium that can record only once, and the rewritable optical information medium, the area ratio at the adhesion level 3 needs to be 6% or less. .
[0095]
A preferable optical information medium of the present invention is a dispersion liquid for evaluation adhered per unit area of the surface where the adhesion operation is performed when the dispersion liquid for evaluation is adhered to the recording / reproducing beam incident side surface at the adhesion level 3. The area ratio occupied by the droplet is 4.8% or less. When the area ratio at the adhesion level 3 is 4.8% or less, the recording / reproducing beam incident side surface is more excellent in antifouling property, and even when recording is performed after the fingerprint is adhered to the surface, the error rate characteristic is obtained. It is an optical information medium that is very excellent in quality. This is a very important characteristic in the case of an optical information medium that can be recorded only once and a rewritable optical information medium.
[0096]
Further, in the preferred optical information medium of the present invention, when the dispersion liquid for evaluation is adhered to the recording / reproducing beam incident side surface by the above-mentioned adhesion level 1, that is, the procedure of A → B → C → F, the adhesion operation is performed. The ratio of the area occupied by the evaluation dispersed droplets adhered per unit area of the surface is 4.9% or less. Even at a large fingerprint adhesion level such as adhesion level 1, if the area ratio is 4.9% or less, the surface of the medium is very excellent in antifouling properties.
[0097]
【Example】
Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited to these Examples.
[0098]
[Disk sample No. Production of 1: the present invention]
The optical recording disk sample No. having the layer configuration shown in FIG. No. 1 was produced as follows.
A disc-shaped support substrate (20) (groove formed, for recording information, made of polycarbonate, having a diameter of 120 mm and a thickness of 1.1 mm) has a surface on which the grooves are formed. ₉₈ Pd ₁ Cu ₁ A reflection layer (3) having a thickness of 100 nm (atomic ratio) was formed by a sputtering method. The depth of the groove was represented by λ / 6 as an optical path length at a wavelength λ = 405 nm. The recording track pitch in the groove recording method was 0.3 μm.
[0099]
Next, on the surface of the reflective layer (3), Al ₂ O ₃ A 20-nm-thick second dielectric layer (52) was formed by sputtering using a target. A 12 nm thick recording layer (4) was formed on the surface of the second dielectric layer (52) by a sputtering method using an alloy target made of a phase change material. The composition (atomic ratio) of the recording layer (4) is Sb ₇₄ Te ₁₈ (Ge ₇ In ₁ ). On the surface of the recording layer (4), ZnS (80 mol%)-SiO ₂ (20 mol%) A first dielectric layer (51) having a thickness of 130 nm was formed by a sputtering method using a target.
[0100]
Next, a radical polymerizable ultraviolet curable material having the following composition is applied to the surface of the first dielectric layer (51) by spin coating, and irradiated with ultraviolet light so that the cured film has a thickness of 98 μm. A transmission layer (7) was formed.
[0101]
(Light transmitting layer: composition of ultraviolet curable material)
Urethane acrylate oligomer 50 parts by weight
(Diabeam UK6035 manufactured by Mitsubishi Rayon Co., Ltd.)
Isocyanuric acid EO modified triacrylate 10 parts by weight
(Aronix M315, manufactured by Toa Gosei Co., Ltd.)
Isocyanuric acid EO-modified diacrylate 5 parts by weight
(Aronix M215, manufactured by Toa Gosei Co., Ltd.)
25 parts by weight of tetrahydrofurfuryl acrylate
Irgacure 184 (polymerization initiator) 3 parts by weight
[0102]
Next, an ultraviolet / electron beam-curable hard coat agent having the following composition is applied on the light transmitting layer (7) by spin coating to form a coating, and the coating is heated at 60 ° C. for 3 minutes in the air to dilute the inside of the coating. The solvent was removed, and thereafter, a hard coat layer (8) having a thickness of 2 μm after curing was formed by irradiating ultraviolet rays.
[0103]
(Composition of hard coat agent)
Reactive group-modified colloidal silica (dispersion medium: propylene glycol monomethyl acrylate)
Tel acetate, non-volatile content: 40% by weight) 100 parts by weight
48 parts by weight of dipentaerythritol hexaacrylate
12 parts by weight of tetrahydrofurfuryl acrylate
Propylene glycol monomethyl ether acetate 40 parts by weight
(Non-reactive diluting solvent)
Irgacure 184 (polymerization initiator) 3 parts by weight
[0104]
Further, an ultraviolet / electron beam curable fluorine-based antifouling agent having the following composition is applied on the hard coat layer (8) by a spin coating method to form a coating, and the coating is heated at 60 ° C. for 3 minutes in the air to form the inside of the coating. After removing the diluting solvent, an electron beam was irradiated to form a surface layer (9) having a thickness of about 30 nm after curing. Thus, the disc sample No. 1 was produced.
[0105]
(Composition of antifouling agent)
1 part by weight of perfluoropolyether diacrylate
(Fobrin ZDOL acrylate modified product from Audimont, molecular weight about 2000)
3-perfluorooctyl-2-hydroxypropyl acrylate
(R-1833, manufactured by Daikin Fine Chemical Laboratory) 3 parts by weight
Fluorine solvent
(Sumitomo 3M Co., Ltd., Florinert FC-77) 1600 parts by weight
[0106]
The following disk sample Nos. 2 to 6 are optical recording disk samples having the layer configuration shown in FIG.
[0107]
[Disk sample No. Preparation of 2: the present invention]
Until the formation of the light transmitting layer (7), the above disk sample No. Performed in the same manner as in 1.
[0108]
On the light transmitting layer (7), an ultraviolet / electron beam-curable hard coat agent having the following composition is applied by a spin coating method to form a film, and heated at 60 ° C. for 3 minutes in the air to remove the diluting solvent inside the film. After removal, the film was irradiated with ultraviolet rays to form a cured hard coat layer (8) having a thickness of 2 μm. Thus, the disc sample No. 2 was produced.
[0109]

[0110]
[Disk sample No. Preparation of 3: the present invention]
Disk sample No. Disc Sample No. 2 was prepared except that the composition of the hard coat agent in Sample No. 2 was changed as follows. 2 in the same manner as in disk sample No. 2. 3 was produced.
[0111]
(Composition of hard coat agent)
Reactive group-modified colloidal silica (dispersion medium: propylene glycol monomethyl acrylate)
Tel acetate, non-volatile content: 40% by weight) 100 parts by weight
48 parts by weight of dipentaerythritol hexaacrylate
12 parts by weight of tetrahydrofurfuryl acrylate
Propylene glycol monomethyl ether acetate 40 parts by weight
(Non-reactive diluting solvent)
Irgacure 184 (polymerization initiator) 5 parts by weight
0.25 parts by weight of bifunctional silicone methacrylate
(X-22-164A, manufactured by Shin-Etsu Chemical Co., Ltd.)
[0112]
[Disk sample No. Production of No. 4: Comparative Example]
Disk sample No. Disc Sample No. 2 was prepared except that the composition of the hard coat agent in Sample No. 2 was changed as follows. 2 in the same manner as in disk sample No. 2. 4 was produced.
[0113]
(Composition of hard coat agent)
Reactive group-modified colloidal silica (dispersion medium: propylene glycol monomethyl acrylate)
Tel acetate, non-volatile content: 40% by weight) 100 parts by weight
0.05 parts by weight of bifunctional silicone methacrylate
(X-22-164A, molecular weight 1500, manufactured by Shin-Etsu Chemical Co., Ltd.)
48 parts by weight of dipentaerythritol hexaacrylate
12 parts by weight of tetrahydrofurfuryl acrylate
Propylene glycol monomethyl ether acetate 40 parts by weight
(Non-reactive diluting solvent)
Irgacure 184 (polymerization initiator) 5 parts by weight
[0114]
[Disk sample No. Production of Comparative Example 5: Comparative Example]
Disk sample No. Disc Sample No. 2 was prepared except that the composition of the hard coat agent in Sample No. 2 was changed as follows. 2 in the same manner as in disk sample No. 2. 5 was produced.
[0115]
(Composition of hard coat agent)
Reactive group-modified colloidal silica (dispersion medium: propylene glycol monomethyl acrylate)
Tel acetate, non-volatile content: 40% by weight) 100 parts by weight
0.025 parts by weight of bifunctional silicone methacrylate
(X-22-164A, molecular weight 1500, manufactured by Shin-Etsu Chemical Co., Ltd.)
48 parts by weight of dipentaerythritol hexaacrylate
12 parts by weight of tetrahydrofurfuryl acrylate
Propylene glycol monomethyl ether acetate 40 parts by weight
(Non-reactive diluting solvent)
Irgacure 184 (polymerization initiator) 5 parts by weight
[0116]
[Disk sample No. Production of Comparative Example 6: Comparative Example]
Disk sample No. Disc Sample No. 2 was prepared except that the composition of the hard coat agent in Sample No. 2 was changed as follows. 2 in the same manner as in disk sample No. 2. No. 6 was produced.
[0117]
(Composition of hard coat agent)
Reactive group-modified colloidal silica (dispersion medium: propylene glycol monomethyl acrylate)
Tel acetate, non-volatile content: 40% by weight) 100 parts by weight
48 parts by weight of dipentaerythritol hexaacrylate
12 parts by weight of tetrahydrofurfuryl acrylate
Propylene glycol monomethyl ether acetate 40 parts by weight
(Non-reactive diluting solvent)
Irgacure 184 (polymerization initiator) 5 parts by weight
[0118]
[Adhesion of evaluation dispersion to disc sample]
(Preparation of dispersion for evaluation)
0.4 parts by weight of Kanto loam of 11th kind of test powder 1 (medium diameter: 1.6 to 2.3 μm) specified as JIS Z8901 as fine particles, 1 part by weight of triolein as a dispersion medium, and 10 parts by weight of methoxypropanol was mixed and stirred as a diluent to prepare a dispersion for evaluation.
[0119]
(Preparation of master for transfer of dispersion for evaluation)
A master for transfer of a dispersion for evaluation was prepared as follows. 1 mL of the dispersion for evaluation was collected while being sufficiently stirred with a magnetic stirrer, and applied to a polycarbonate substrate (120 mm in diameter, 1.2 mm in thickness) by a spin coating method. The spin coating was performed by dropping 1 mL of the dispersion for evaluation onto a substrate, rotating at 500 rpm for 3 seconds, and then immediately rotating at 250 rpm for 3 seconds. The substrate was heated at 60 ° C. for 3 minutes to completely remove methoxypropanol as an unnecessary diluent. Thus, an original plate for transfer of the dispersion for evaluation was obtained.
[0120]
(Transfer of the evaluation dispersion onto the disk sample surface)
The evaluation dispersion component was transferred to the surface of the hard coat layer (8) or the surface layer (9) of each disk sample at the adhesion level 3 shown below.
[0121]
Adhesion level 3:
No. A pseudo-fingerprint transfer material obtained by uniformly roughening the smaller end surface (diameter 12 mm) of the silicone rubber stopper 1 with abrasive paper # 240 (having the same performance as AA240 abrasive paper specified in JIS R6251 or JIS R6252). Used as The roughened end face of the pseudo-fingerprint transfer material was pressed against the original plate under a load of 4.9 N for 10 seconds to transfer the dispersion component for evaluation to the end face of the transfer material.
[0122]
Thereafter, the end surface of the transfer material to which the dispersion component for evaluation is adhered is pressed against the smooth surface of the polycarbonate substrate with a load of 4.9 N for 10 seconds to determine the amount of the dispersion component for evaluation on the end surface of the transfer material. Reduced. Again, the end face of the transfer material was pressed against a different portion of the polycarbonate substrate at a load of 4.9 N for 10 seconds to further reduce the amount of the evaluation dispersion component adhering to the end face of the transfer material.
[0123]
Then, the end face of the transfer material to which the dispersion component for evaluation was attached was placed at a position of about 40 mm radially from the center of the surface of the hard coat layer (8) or surface layer (9) of each disk sample, and a load of 4.9 N was applied. For 10 seconds to transfer the dispersion component for evaluation.
[0124]
Further, the disc sample No. With respect to Nos. 1 and 3, transfer of the evaluation dispersion component to the surface of the hard coat layer (8) or the surface layer (9) of each disk sample was also performed at the adhesion level 1 shown below.
[0125]
Adhesion level 1:
In the operation of the adhesion level 3, the operation of reducing the amount of the dispersion component component for evaluation of the transfer material was not performed.
[0126]
(Measurement of the area ratio occupied by the dispersed droplets for evaluation per unit area of the surface)
The state of the dispersion droplets for evaluation attached to the surface of each disk sample was observed with an optical microscope (manufactured by Keyence, VK-8510), and the image was output by a printer (manufactured by Keyence, VH-P40). The image is taken into a computer, and image processing analysis software Win ROOF Ver. The area ratio of the dispersion droplets for evaluation to the whole was measured using a 3.61 demo version (manufactured by Mitani Corporation). The results for adhesion level 3 are shown in Table 1 and the results for adhesion level 1 are shown in Table 2.
[0127]
[Disk sample No. Evaluation of 1-6]
(Measurement of initial error rate)
The following conditions were used for each disk sample using an optical recording medium evaluation device (DDU-1000, manufactured by Pulstec Industrial):
Laser wavelength λ: 405 nm, NA of objective lens: 0.85, modulation method: (1,7) RLL, channel bit length: 0.12 μm, recording linear velocity: 5.3 m / s, channel clock: 66 MHz, recording signal : Mixed signal of 2T to 8T, data transfer rate: 36 Mbps
After recording, the bit-by-bit error rate (bER) was measured with the same evaluation device (DDU-1000, laser wavelength λ: 405 nm, NA: 0.85) (initial error rate). The initial error rate of each disk sample is 0 or 1 × 10 ^-7 Was either.
[0128]
(Measurement of error rate I)
After recording on each disk sample under the same conditions as above, the dispersion droplets for evaluation were adhered to the surface of the hard coat layer (8) or surface layer (9) of each disk sample by the operation of the adhesion level 3 described above, and evaluated. The bit-by-bit error rate-I (bER-I) was measured in the same manner as described above, with the applied dispersion droplets attached. At this time, the measurement was performed by opening the gate for 4 msec around the portion where the dispersion droplet for evaluation was attached.
[0129]
(Error rate measurement II)
The dispersion droplets for evaluation were adhered to the surface of the hard coat layer (8) or the surface layer (9) of each of the unrecorded disk samples by the operation of the adhesion level 3 described above. Recording was performed under the same conditions. Thereafter, the bit-by-bit error rate-II (bER-II) was measured in the same manner as described above. At this time, the measurement was performed by opening the gate for 4 msec around the portion where the dispersion droplet for evaluation was attached.
[0130]
Table 1 shows the above measurement results.
[0131]
[Table 1]

[0132]
From Table 1, it is found that the disc sample No. In the case of 1 to 3, the error rate -I was 2 × 10 with the dispersion droplets for evaluation attached at the attachment level 3 after recording. ^-6 , 1 × 10 ^-5 , 6 × 10 ^-5 And practical range (1 × 10 ^-4 Below), and it was shown that reproduction was possible well. That is, when the area ratio at the adhesion level 3 is 6% or less, the film has high fingerprint adhesion resistance, and can be favorably used at least as a read-only optical disk.
[0133]
The preferred disk sample No. of the present invention. In Examples 1 and 2, even when recording was performed in a state where the evaluation dispersed droplets were adhered at the adhesion level 3 without recording, the error rate -II was 1 × 10 ^-7 , 9 × 10 ^-5 And practical range (1 × 10 ^-4 Below), indicating that recording and reproduction can be performed well. That is, if the area ratio at the adhesion level 3 is 4.8% or less, the adhesive has higher fingerprint adhesion resistance, and can be used as an optical disk that can be recorded only once or as a rewritable optical disk. Can be.
[0134]
The disk sample No. When the static contact angles of 1, 3, 4, 5, and 6 were measured in an environment of 20 ° C. and 60% RH using triolein as a measurement solution, the values shown in Table 1 were obtained. The measurement was performed using a contact angle meter FACE CONTACT-ANGLEMETER of Kyowa Interface Science Co., Ltd.
[0135]
(Measurement of error rate III)
Disk sample No. 1 and 3 were evaluated at adhesion level 1.
The dispersion droplets for evaluation were adhered to the surface of the hard coat layer (8) or the surface layer (9) of each unrecorded disk sample by the operation of the adhesion level 1 described above. Recording was performed under the same conditions. Thereafter, the bit-by-bit error rate-III (bER-III) was measured in the same manner as described above. At this time, the measurement was performed by opening the gate for 4 msec around the portion where the dispersion droplet for evaluation was attached. Table 2 shows the above measurement results.
[0136]
[Table 2]

[0137]
The preferred disk sample No. of the present invention. In the case of No. 1, the error rate-III was 1 × 10 even when recording was performed in a state where the evaluation dispersed droplets were adhered at the adhesion level 1 without recording. ^-5 And practical range (1 × 10 ^-4 Below), indicating that recording and reproduction can be performed well. In other words, when the area ratio at the adhesion level 1 is 4.9% or less, it has very high fingerprint adhesion resistance.
[0138]
[Disk sample No. Production of No. 7: Present Invention]
Until the formation of the first dielectric layer (51), the above disk sample No. Performed in the same manner as in 1.
[0139]
On the surface of the first dielectric layer (51), the disk sample No. The same UV-curable material as used for forming the first light-transmitting layer (7) was applied by spin coating to form a resin material layer having a cured thickness of 2 μm.
[0140]
Next, a 100 μm-thick polycarbonate sheet was placed on the uncured resin material layer in a vacuum (0.1 atm or less). Pure Ace manufactured by Teijin Limited by a casting method was used as the polycarbonate sheet. Subsequently, the atmosphere was returned to the atmospheric pressure, and the polycarbonate sheet was adhered by irradiating ultraviolet rays to cure the resin material layer, thereby forming a light transmitting layer (7).
[0141]
The above disk sample No. A hard coat layer (8) having a thickness of 2 μm after curing is formed on the light transmitting layer (7), and a surface having a thickness of about 30 nm after curing is formed on the hard coat layer (8) in the same manner as in (1). Layer (9) was formed. Thus, the disc sample No. 7 was produced.
[0142]
Disk sample No. For disk sample no. When the evaluation was performed in the same manner as in the case of No. 1, the same result was obtained.
[0143]
In the above-described embodiment, an example of the phase-change optical disk has been described. However, the present invention is applied not only to an optical disk having a recording layer of a phase change type, but also to a read-only optical disk and a write-once optical disk. Therefore, the above-described embodiment is merely an example in every aspect, and should not be construed as limiting. Furthermore, all modifications belonging to the equivalent scope of the claims are within the scope of the present invention.
[0144]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the present invention, the recording and / or reproducing beam incident side surface has excellent antifouling property and anti-fingerprint adhesion property. Even when a fingerprint adheres to the surface, the amount of adhesion is small, and the error rate characteristic during reproduction is improved. A very good optical information medium is provided.
[0145]
ADVANTAGE OF THE INVENTION According to this invention, the optical information which is excellent in the antifouling property and fingerprint-adhesion resistance of the recording and / or reproducing beam incident side surface, and which is very excellent in the error rate characteristic even when recording is performed after the fingerprint adheres to the surface. A medium is provided.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing one configuration example of an optical information medium.
FIG. 2 is a schematic sectional view showing another configuration example of the optical information medium.
FIG. 3 is a schematic sectional view showing another configuration example of the optical information medium.
FIG. 4 is a schematic sectional view showing another configuration example of the optical information medium.
FIG. 5 is a schematic sectional view showing another configuration example of the optical information medium.
[Explanation of symbols]
(20): Support substrate
(3): Reflective layer
(52): Second dielectric layer
(4): Recording layer
(51): First dielectric layer
(7): Light transmitting layer
(8): Hard coat layer
(9): Surface layer

Claims (9)

0.4 parts by weight of Kanto loam of 11th class of test powder 1 as specified in JIS Z8901 as fine particles and 1 part by weight of triolein as a dispersion medium on the recording and / or reproducing beam incident side surface of the optical information medium. And an evaluation dispersion containing 10 parts by weight of methoxypropanol as a diluent, according to the following procedure:
A. The dispersion for evaluation is coated on a polycarbonate substrate for the master by spin coating to prepare a master for transfer of the dispersion for evaluation,
B. Prepare a transfer material made of silicone rubber,
C. The transfer material is pressed against the surface of the prepared master plate to which the evaluation dispersion is applied at a constant load of 4.9 N for 10 seconds to transfer the evaluation dispersion components to the transfer material.
D. The transfer material to which the dispersion component for evaluation has been transferred is pressed against the surface of the polycarbonate substrate for reducing the amount of adhesion with a constant load of 4.9 N for 10 seconds to reduce the amount of the dispersion component for evaluation,
E. FIG. The transfer material with the reduced amount of the dispersion component for evaluation is pressed against another portion of the surface of the polycarbonate substrate for reduction of the adhesion amount with a constant load of 4.9 N for 10 seconds to further increase the amount of the dispersion component for evaluation. Reduce
F. The transfer material in which the adhesion amount of the dispersion component for evaluation has been reduced twice is pressed against the recording and / or reproduction beam incident side surface of the optical information medium with a constant load of 4.9 N for 10 seconds to apply the dispersion component for evaluation. An optical information medium in which, when adhered to the surface of the optical information medium, the area ratio of dispersed droplets for evaluation occupying per unit area of the surface on which the attaching operation is performed is 6% or less. 2. The optical information medium according to claim 1, wherein the area ratio occupied by the evaluation dispersion droplets adhered per unit area of the surface on which the adhesion operation is performed is 4.8% or less. 3. 0.4 parts by weight of Kanto loam of 11th class of test powder 1 as specified in JIS Z8901 as fine particles and 1 part by weight of triolein as a dispersion medium on the recording and / or reproducing beam incident side surface of the optical information medium. And an evaluation dispersion containing 10 parts by weight of methoxypropanol as a diluent, according to the following procedure:
A. The dispersion for evaluation is coated on a polycarbonate substrate for the master by spin coating to prepare a master for transfer of the dispersion for evaluation,
B. Prepare a transfer material made of silicone rubber,
C. The transfer material is pressed against the surface of the prepared master plate to which the evaluation dispersion is applied at a constant load of 4.9 N for 10 seconds to transfer the evaluation dispersion components to the transfer material.
F. The transfer material into which the dispersion component for evaluation has been transferred is pressed against the recording and / or reproduction beam incident side surface of the optical information medium with a constant load of 4.9 N for 10 seconds to apply the dispersion component for evaluation to the surface of the optical information medium. An optical information medium in which the ratio of the area occupied by the evaluation dispersed droplets per unit area of the surface on which the attaching operation is performed is 4.9% or less. The optical information medium according to any one of claims 1 to 3, which is used in a system in which a minimum diameter of a recording and / or reproducing beam on a recording and / or reproducing beam incident side surface is 500 µm or less. Claims: At least an information recording layer on a support base, a light transmission layer on the information recording layer, and a hard coat layer on the light transmission layer, wherein the hard coat layer is on the recording and / or reproduction beam incident side. Item 5. The optical information medium according to any one of Items 1 to 4. The optical information medium according to claim 5, wherein the hard coat layer includes a cured product of a composition containing an active energy ray-curable silicone compound and / or a fluorine compound. The optical information according to claim 5 or 6, further comprising, on the hard coat layer, a surface thin layer made of a cured product of a composition containing an active energy ray-curable silicone-based compound and / or a fluorine-based compound as a main component. Medium. The optical information medium according to claim 5, wherein a total thickness of the light transmitting layer and the hard coat layer is 70 to 150 μm. The optical information medium according to any one of claims 1 to 8, which is used in a recording / reproducing system using a blue laser beam.

Images