JPS612596A - Optical information-recording medium - Google Patents

Optical information-recording medium

Info

Publication number
JPS612596A
JPS612596A JP59123305A JP12330584A JPS612596A JP S612596 A JPS612596 A JP S612596A JP 59123305 A JP59123305 A JP 59123305A JP 12330584 A JP12330584 A JP 12330584A JP S612596 A JPS612596 A JP S612596A
Authority
JP
Japan
Prior art keywords
recording medium
acetal compound
degree
polyvinyl alcohol
cyclohexanone
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP59123305A
Other languages
Japanese (ja)
Other versions
JPH0318259B2 (en
Inventor
Shigeru Nomura
茂 野村
Toshio Kamisaka
上坂　外志夫
Tatsuo Kinoshita
健生 木下
Tetsuo Sumiya
角谷　哲生
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sekisui Chemical Co Ltd
Original Assignee
Sekisui Chemical Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sekisui Chemical Co Ltd filed Critical Sekisui Chemical Co Ltd
Priority to JP59123305A priority Critical patent/JPS612596A/en
Publication of JPS612596A publication Critical patent/JPS612596A/en
Publication of JPH0318259B2 publication Critical patent/JPH0318259B2/ja
Granted legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
    • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
    • G11B7/252—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers
    • G11B7/253—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of substrates
    • G11B7/2533—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of layers other than recording layers of substrates comprising resins

Landscapes

  • Optical Record Carriers And Manufacture Thereof (AREA)
  • Thermal Transfer Or Thermal Recording In General (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

Abstract

PURPOSE:To ensure low water absorptivity, favorable heat resistance and high moldability, by constituting a synthetic resin essentially of an acetal compound obtained by converting polyvinyl alcohol to an acetal compound with a degree of conversion of not lower than 65mol% by using cyclohexanone. CONSTITUTION:The synthetic resin is constituted of an acetal compound obtained by converting polyvinyl alcohol to an acetal compound with a degree of conversion of not lower than 65mol% by using cyclohexanone. Since the acetal compound has excellent heat resistance and low water absorptivity, an information-recording medium formed therefrom is not strained during preservation. In addition, since the acetal compound becomes rich in fluidity when being melted, it can be easily molded, and even the shape of minute pits of a stamper can be securely transferred to the molded article. Further, strains or orientation is hardly left in the recording medium upon forming, so that double refraction will not occur. By using the recording material, disks with high capacity and high quality can be easily produced.

Description

【発明の詳細な説明】 この発明は、光学式情報記録体に関するものであり、と
くに光学式情報記録体を特定の熱可塑性合成樹脂で構成
することを内容とするものである。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical information recording medium, and in particular, the optical information recording medium is made of a specific thermoplastic synthetic resin.

光学式情報記録体は、これに光をあてたとき反射する光
又は透過する光により、情報を提供するものである。こ
れは、ビデオディスク、オーディオディスク、情−ファ
イルディスク等として既に使用されている。2. Description of the Related Art An optical information recording medium provides information through reflected or transmitted light when light is applied to it. This has already been used as a video disc, audio disc, information file disc, etc.

光学式情報記録体は、狂いの少ない透明板を基盤とし、
この基盤上に設けた溝又は凹凸によって情報を記録して
いる。実際には、一つの基盤上に多数の情報を収録する
ために、溝又は凹凸は数ミクロン程度、またはそれ以下
の小さ力幅のものとされ、しかも互に密接して付設され
る。このように密接した小さな幅の溝又は凹凸に光をあ
てて、反射又は透過してくる光を情報とするのであるか
ら、基盤は透明であって、且つ極端に狂いの少ないもの
でなければならない。すなわち、基盤は透明で形状安定
性にすぐれたものであることが必要とされ、とくに耐熱
性があって吸湿性の少ないことが要求される。その上に
、基盤は、板に成形することが容易なものでなければな
らない。The optical information recording medium is based on a transparent plate with little distortion,
Information is recorded by grooves or irregularities provided on this base. In practice, in order to record a large amount of information on one substrate, the grooves or irregularities have a small force width of several microns or less, and are attached closely to each other. Since light is shined on these closely spaced small-width grooves or irregularities and the reflected or transmitted light is used as information, the base must be transparent and have extremely few irregularities. . That is, the substrate is required to be transparent and have excellent shape stability, and in particular, it is required to have heat resistance and low moisture absorption. Additionally, the base must be easy to form into a board.

このような必要から、光学式情報記録体の基盤を合成樹
脂で作ることが行なわれた。今まで用いられた合成樹脂
は、主としてポリメチルメタクリレート（以下、ＰＭＭ
Ａという）と、ポリカーボネート（以下、ｐｏという）
とである。これらは何れも透明性にすぐれ、また形状安
定性もすぐれている。しかし、仔細に検討すると、ＰＭ
ＭＡけ吸湿性が大きく、従って湿度の高いところに置く
と、基盤がそって変形を起すという欠点があった。Because of this need, the base of optical information recording bodies has been made of synthetic resin. The synthetic resins used so far are mainly polymethyl methacrylate (hereinafter referred to as PMM
A) and polycarbonate (hereinafter referred to as po)
That is. All of these have excellent transparency and shape stability. However, upon careful consideration, PM
MA has a high hygroscopicity, so if it is placed in a place with high humidity, it has the disadvantage that the substrate warps and deforms.

また、ＰＯは、吸湿によって変形を起すことは少ないが
、表面硬度が低く傷がつきやすい上に、成形しＫ＜＜、
成形したものは成形時の配向が基盤中に残るため、複屈
折を起すこととなり、従って反射又は透過光を乱すとい
う欠点があった。従って、今まで用いられて来た合成樹
脂は、何れも満足なものではなかった。In addition, PO rarely deforms due to moisture absorption, but its surface hardness is low and it is easily scratched, and it is difficult to mold.
Molded products have the disadvantage that the orientation during molding remains in the substrate, resulting in birefringence, which disturbs reflected or transmitted light. Therefore, none of the synthetic resins used so far have been satisfactory.

そこで、この発明者は、光学式情報記録体の基盤を構成
するに適した合成樹脂を見出そうと企てた。そのために
、この発明者は、種々の透明な硬質合成樹脂を作り、そ
の性質を検討した。そのうちで、この発明者は、ポリビ
ニルアルコールのアセタール化物が、硬質であって透明
で、アセクール化度を上げると吸湿性が小さくなり、従
って形状安定性がよくなることに気付いた。さらに、ポ
リビニルアルコールをアセタール化するに当り、従来は
専らアルデヒド類が用いられて米たが、その代りにケト
ンの一種たるシクロヘキサノンを用いてアセタール化す
ると、吸水性が少なくて耐熱性の向上したものとなり、
従って形１状安定性がよくて、しかも成形が容易な合成
樹脂が得られることを確認した。従って、この樹脂は、
情報記録体を作るに適したものであることを見出した。Therefore, the inventor set out to find a synthetic resin suitable for forming the base of an optical information recording medium. To this end, the inventor created various transparent hard synthetic resins and studied their properties. Among these, the inventor noticed that an acetalized product of polyvinyl alcohol is hard and transparent, and that increasing the degree of acetalization reduces hygroscopicity and therefore improves shape stability. Furthermore, in acetalizing polyvinyl alcohol, conventionally only aldehydes were used, but when cyclohexanone, a type of ketone, is used instead for acetalization, it has less water absorption and improved heat resistance. Then,
Therefore, it was confirmed that a synthetic resin with good shape stability and easy molding could be obtained. Therefore, this resin is
It was discovered that this material is suitable for making information records.

この発明け、このような知見に基づいて完成されたもの
である。This invention was completed based on such knowledge.

この発明け、透明な合成樹脂板を基盤とする情報記録体
において、上記合成樹脂が、シクロへキサノンを用いて
ポリビニルアルコールを６５モル％以上にアセタール化
して得られたアセタール化物で、実質的に構成されてい
ることを特徴とする、光学式情報記録体に関するもので
ある。This invention provides an information recording medium based on a transparent synthetic resin plate, in which the synthetic resin is an acetalized product obtained by acetalizing polyvinyl alcohol to 65 mol% or more using cyclohexanone; The present invention relates to an optical information recording medium characterized by the following configuration.

この発明で用いられる合成樹脂はポリビニルアセタール
の一種である。これは、シクロヘキサノンによりポリビ
ニルアルコールをアセタール化して得られる。アセター
ル化は、適当な溶媒の中で、ポリビニルアルコールに大
過剰のシクロヘキサノンを加え、塩酸のような酸触媒の
下に放置することによって行なわれる。この場合、生成
するアセタール化物を溶解しない水のような溶媒を用い
るか、それともアセタール化物を溶解する有機溶媒を用
いるかによって、若干反応の模様を異にする。The synthetic resin used in this invention is a type of polyvinyl acetal. This is obtained by acetalizing polyvinyl alcohol with cyclohexanone. Acetalization is carried out by adding a large excess of cyclohexanone to polyvinyl alcohol in a suitable solvent and leaving it under an acid catalyst such as hydrochloric acid. In this case, the pattern of the reaction differs slightly depending on whether a solvent such as water that does not dissolve the acetalized product to be produced or an organic solvent that dissolves the acetalized product is used.

ここで大過剰とは、理論上必要とされる量の５ないし１
０倍量とすることが望ましい。Here, a large excess means 5 to 1 of the theoretically required amount.
It is desirable to use 0 times the amount.

ポリビニルアルコールとしては、鹸化度９５モル％以上
のものを使用する必要がある。その理由は、アセチル基
が５モル％以上台まれているポリビニルアルコールを用
いると、得られたアセタール化物が透明とならないで、
透明性の悪いものとなるからである。As the polyvinyl alcohol, it is necessary to use one having a degree of saponification of 95 mol% or more. The reason is that when polyvinyl alcohol containing 5 mol% or more of acetyl groups is used, the resulting acetalized product does not become transparent.
This is because transparency becomes poor.

溶媒として水を用いる場合には、ポリビニルアセタール
を水に溶解し、得られた溶液、に触媒を加え、次いでシ
クロヘキサノンを大過剰に加えて暫らく放置すると、沈
澱が生ずる。この沈澱がアセタール化物である。これを
加温すると、アセタール化反応がさらに進行し、多量の
アセタール化物を得ることができる。溶媒として有機溶
媒、例えばブタノールやトルエンのような有機溶媒を使
用する場合には、ポリビニルアルコールを有機溶媒中に
加えて分散させ、これに触媒を加え、次いで大過剰のシ
クロヘキサノンを加え、暫時加熱し、反応させてアセタ
ール化物を得ることができる。When water is used as a solvent, polyvinyl acetal is dissolved in water, a catalyst is added to the resulting solution, and then a large excess of cyclohexanone is added and the solution is left to stand for a while, causing precipitation. This precipitate is an acetalized product. When this is heated, the acetalization reaction further progresses, and a large amount of acetalized product can be obtained. When using an organic solvent such as butanol or toluene as a solvent, polyvinyl alcohol is added and dispersed in the organic solvent, a catalyst is added thereto, and then a large excess of cyclohexanone is added and heated for a while. , can be reacted to obtain an acetalized product.

何れの場合も、アセタール化物が生成してのち、触媒を
中和して除き、水洗し、乾燥して固状のアセタール化物
とする。In either case, after the acetalized product is produced, the catalyst is neutralized and removed, washed with water, and dried to form a solid acetalized product.

こうして得られたアセタール化物は、熱可塑性の硬質樹
脂であって、加熱すると軟化して流動性のものとなる。The acetalized product thus obtained is a hard thermoplastic resin, and when heated, it softens and becomes fluid.

そのため、アセタール化物は、例えば射出成形法によっ
て容易に板とすることができる。従って、アナクール化
物は、成形が容易で且つ能率よく板に加工することがで
きる。Therefore, the acetalized product can be easily made into a plate by, for example, injection molding. Therefore, the anacooled product can be easily molded and efficiently processed into a plate.

また、こうして得られたアセタール化物は、アセタール
化度が低いときけ吸湿性が大きく、従って湿気を吸収し
て反る傾向を持つが、アセタール化度が大きくなるに従
って吸湿性が次第に小さくなる。アセタール化度が６５
モル％以上になると、吸湿性が殆んどなくなり、従って
変形することが殆んどなくなる。だから、この発明では
アセタール化度６５モル％以上のアセタール化物を使用
するＯ アセタール化物は、原料として用いたポリビニルアルコ
ールの重合度によって多少軟化点を異にする。また、そ
れに伴なって加熱溶融時の粘性を異にし、従って射出成
形の難易を異にする。すなわち、重合度が低いと、アセ
タール化物はこれを成形するのけ容易であるが、反面軟
化点が低くなり、従って形状安定性が悪くなる。逆に、
重合度が高いと成形しにくくなる。そのため、ポリビニ
ルアルコールの重合度としてけ１００ないし２０００の
ものが適している。Furthermore, the acetalized product thus obtained exhibits high hygroscopicity when the degree of acetalization is low, and thus has a tendency to absorb moisture and warp, but as the degree of acetalization increases, the hygroscopicity gradually decreases. Acetalization degree is 65
When the amount exceeds mol%, there is almost no hygroscopicity, and therefore almost no deformation occurs. Therefore, in the present invention, the softening point of the O acetalized product used is an acetalized product having a degree of acetalization of 65 mol % or more depending on the degree of polymerization of the polyvinyl alcohol used as a raw material. Additionally, the viscosity upon heating and melting differs, and therefore the difficulty of injection molding differs. That is, if the degree of polymerization is low, the acetalized product can be easily molded, but on the other hand, the softening point will be low, resulting in poor shape stability. vice versa,
If the degree of polymerization is high, it becomes difficult to mold. Therefore, a degree of polymerization of polyvinyl alcohol of 100 to 2000 is suitable.

この発明で用いられるアセタール化物は、シクロヘキサ
ノンによってアセタール化された部分（化工、これをシ
クロ部分という）を含むことが特徴とされる。このよう
なアセタール化物は、シクロ部分の含有量が多く々るに
つれて、耐熱性が向上するとともに吸湿性が小になる傾
向を持っている。この傾向は、ブチラールのような従来
のアセタール化物で、脂肪族アルデヒドによるアセター
ル化部分（以下、これを脂肪族部分という）だけを持っ
たものでは見られなかった傾向である。The acetalized product used in this invention is characterized by containing a moiety acetalized with cyclohexanone (chemical processing, this is referred to as a cyclo moiety). Such acetal compounds tend to have improved heat resistance and decreased hygroscopicity as the content of cyclo moieties increases. This tendency has not been observed in conventional acetalized products such as butyral, which have only an acetalized moiety with an aliphatic aldehyde (hereinafter referred to as an aliphatic moiety).

すなわち、脂肪族部分を持ったアセタール、例えばポリ
ビニルブチラールでは、耐熱性・を向上させようとする
と、吸湿性が大きくなる傾向を持つていた。ところが、
シクロ部分を持ったアセタールは、耐熱性が向上すると
ともに吸湿性が減少する傾向を持っているので、形状安
定性のよい樹脂となる。従って、この発明で用いられる
アセタール化物は、ディスク基盤として用いるに適した
ものである。That is, acetals having aliphatic moieties, such as polyvinyl butyral, tend to have increased hygroscopicity when trying to improve heat resistance. However,
Acetal having a cyclo moiety has a tendency to improve heat resistance and reduce hygroscopicity, so it becomes a resin with good shape stability. Therefore, the acetalized product used in this invention is suitable for use as a disk substrate.

ポリビニルアルコールのシクロヘキサノンによるアセタ
ール化物は、これを実際に光学式情報記録体とする際に
、これに少量の老化防止剤、酸化防止剤、滑剤等が添加
される。こうして得られた配合物を板状に成形するには
、射出成形によるのが便利である。射出成形は、樹脂配
合物を加熱溶融しておき、樹脂溶融物を冷却した金型内
に流し込んで成形するので、成形能率が極めてよい。そ
こで、成形性の良否は主として射出成形の難易によって
定めるとさとし、従って情報記録体としての良否も射出
成形して得た板について測定することとした。When the acetalized product of polyvinyl alcohol with cyclohexanone is actually used as an optical information recording medium, a small amount of anti-aging agent, antioxidant, lubricant, etc. is added to the product. In order to mold the thus obtained compound into a plate shape, it is convenient to use injection molding. In injection molding, the resin compound is heated and melted, and the molten resin is poured into a cooled mold for molding, so the molding efficiency is extremely high. Therefore, it was decided that the quality of moldability was determined mainly by the difficulty of injection molding, and therefore, the quality of the information recording medium was also measured on the plates obtained by injection molding.

この発明に係る光学式情報記録体は、シクロヘキサノン
を用いてポリビニルアルコールを６５モル％以上にアセ
タール化して得られたアセタール化物で構成されている
。このアセタール化物は、上述のように耐熱性にすぐれ
るとともに吸湿性が少ないという特性を持っているので
、この情報記録体は保存中に歪を生じない。また、この
アセタール化物は溶融したとき流動性に富むから、成形
が容易であり、スタンバ−の微細なビットまでも確実に
成形することができ、しかも成形時の歪や配向を残すこ
とが少なく、従って複・屈折を生ずることもない。だか
ら、この記録体を用いれば、大きな容量を持った良質の
ディスクを容易に作成できるという利点がもたらされる
。The optical information recording medium according to the present invention is composed of an acetalized product obtained by acetalizing polyvinyl alcohol to 65 mol% or more using cyclohexanone. As described above, this acetal compound has the characteristics of excellent heat resistance and low hygroscopicity, so that this information recording medium does not suffer from distortion during storage. In addition, since this acetal compound has high fluidity when melted, it is easy to mold, and even the minute bits of the stubber can be reliably molded, and there is little distortion or orientation left during molding. Therefore, no birefringence occurs. Therefore, the use of this recording medium has the advantage that high-quality disks with large capacities can be easily created.

以下に実施例及び比較例を挙げて、この発明に係る情報
記録体のすぐれていることを説明するが、そこで得られ
た板については次に述べるような性質を調べた。The advantages of the information recording medium according to the present invention will be explained below with reference to Examples and Comparative Examples.The following properties of the obtained boards were investigated.

ｆｌ＋反り 成形によって得た板の片面にアルミニウム金属を蒸着し
、その上にさらに保護皮膜を塗布して蒸着面からの水の
侵入を阻止してのち、この板を２０℃の水中に７２時間
浸漬し、その後これを取出して直ちに平面上に置き、板
の周囲を平面に密接させて、板の中央の浮き上りを測定
した。Aluminum metal was vapor-deposited on one side of the plate obtained by fl+ warp forming, a protective film was further applied on top of it to prevent water from entering from the vapor-deposited surface, and the plate was immersed in water at 20°C for 72 hours. After that, the plate was taken out and immediately placed on a flat surface, the periphery of the plate was brought into close contact with the flat surface, and the rise in the center of the plate was measured.

（２）吸水率 成形によって得た板を２０℃の水中に７２時間浸漬し、
その後これを取出して直ちに板の重量を測定し、重量増
加の割合を吸水率とした。(2) The board obtained by water absorption molding was immersed in water at 20°C for 72 hours,
Thereafter, the plate was taken out and its weight was immediately measured, and the rate of increase in weight was determined as the water absorption rate.

（３）全光線透過率 ＡＳＴＭ　　Ｄ−１００３の方法により測定した。(3) Total light transmittance Measured by the method of ASTM D-1003.

（４）曇価 ＡＳＴＭ　　Ｄ−１００３の方法により測定した。(4) Cloud value Measured by the method of ASTM D-1003.

（５）複屈折 成形によって得た板を２枚の偏光板の間に挾み、可視光
線を透過させて干渉縞を生成させ、干渉縞生成の程度を
観察して複屈折の程度を調べた。(5) The plate obtained by birefringence molding was sandwiched between two polarizing plates, visible light was transmitted therethrough to generate interference fringes, and the degree of birefringence was determined by observing the degree of interference fringe formation.

（６）耐熱変形温度 ＡＳＴＭ　　Ｄ−６４８（１８，６１９／Ｃ：ｒＩ）に
より測定した。(6) Heat distortion temperature Measured according to ASTM D-648 (18,619/C:rI).

実施例１ 鹸化度９９モル％、重合度１７００のポリビニルアルコ
ール１００ｇをシクロへキサノン２０００ｇ中に分散し
、攪拌しながらこれに純分３５重量％の濃塩酸１１０ｇ
ｆ：添加し、その後加熱して６５℃に８時間維持し、ア
セタール化反応を行った。その後、これに苛性ソーダを
加えて塩酸を中和し、次いでこれを約６０１の純水中に
滴下して、粉末樹脂を得た。得られた粉末樹脂をさらに
水洗し、８５℃で９６時間乾燥してアセタール化物を得
た。このアセタール化物はアセタール化度７９．２モル
％であった。Example 1 100 g of polyvinyl alcohol with a degree of saponification of 99 mol% and a degree of polymerization of 1700 was dispersed in 2000 g of cyclohexanone, and 110 g of concentrated hydrochloric acid with a purity of 35% by weight was added to this while stirring.
f: was added and then heated and maintained at 65° C. for 8 hours to perform an acetalization reaction. Thereafter, caustic soda was added to neutralize the hydrochloric acid, and this was then dropped into approximately 601 ml of pure water to obtain a powdered resin. The obtained powdered resin was further washed with water and dried at 85° C. for 96 hours to obtain an acetalized product. This acetalized product had a degree of acetalization of 79.2 mol%.

得られたアセタール化物を射出成形機に入れ、シリンダ
ー１２６０℃に加熱してアセタール化物を溶融し、これ
を９０℃の金型に射出して円板を得た。成形は容易であ
った。得られた円板は、１．２鰭の一様な厚みを持った
直径２００ｆｌの透明円板であった。この円板について
調べた結果は、反りが０．４Ｍ％吸水率が０．３％、全
光線透過率が９２．３％、曇価が０．８％、複屈折がな
く、耐熱変形温度が１１２℃で形状安定性の良好なこと
を認めた。The obtained acetalized product was put into an injection molding machine, and the cylinder was heated to 1260°C to melt the acetalized product, and this was injected into a mold at 90°C to obtain a disk. Molding was easy. The resulting disc was a transparent disc with a diameter of 200 fl and a uniform thickness of 1.2 fins. The results of the investigation on this disc were as follows: warpage: 0.4M%, water absorption: 0.3%, total light transmittance: 92.3%, haze value: 0.8%, no birefringence, and heat deformation resistance temperature: Good shape stability was observed at 112°C.

実　施・例　２ 鹸化度９９．２モル％、重合度１５００のポリビニルア
ルコールｉｏｏｇｌｓｏｏｇの純水に溶解した。この溶
液を１２℃に保ち、これに純分３５重量％の濃塩酸１１
０ｇを添加し、次いでシクロへキサノン１０００ｇを加
えた。す・ると、３０分後に沈澱が析出した。その後２
時間かけて６５℃まで昇温し、６５℃に６時間保ってア
セタール化反応を行わせた。その後、中和水洗してのち
８５℃で９６時間乾燥してアセタール化物ヲ得た。この
アセタール化物はアセタール化度６８．６モル％であっ
た。Implementation/Example 2 Polyvinyl alcohol iooglsoog having a degree of saponification of 99.2 mol% and a degree of polymerization of 1500 was dissolved in pure water. This solution was kept at 12°C, and 11% of concentrated hydrochloric acid with a purity of 35% by weight was added to it.
0 g was added, followed by 1000 g of cyclohexanone. A precipitate was deposited after 30 minutes. After that 2
The temperature was raised to 65°C over time and kept at 65°C for 6 hours to carry out the acetalization reaction. Thereafter, the mixture was neutralized and washed with water, and then dried at 85° C. for 96 hours to obtain an acetalized product. This acetalized product had a degree of acetalization of 68.6 mol%.

このアセタール化物′ｆ：実施例１と全く同様にして射
出成形し、円板を得た。成形は容易であった。得られた
円板は１．２Ｍの一様な厚みを持った直径２００ｆｌの
透明円板であった。この円板について調べた結果は、反
りが１．１闘、吸水率が０．７％、全光線透過率が９１
．９％、曇価が０．８％で、複屈折がなく、耐熱変形温
度が１０７℃で形状安定性の良好なことを認めた。This acetalized product 'f was injection molded in exactly the same manner as in Example 1 to obtain a disk. Molding was easy. The obtained disk was a transparent disk with a diameter of 200 fl and a uniform thickness of 1.2M. The results of investigating this disc were that the warpage was 1.1%, the water absorption rate was 0.7%, and the total light transmittance was 91%.
．． 9%, haze value 0.8%, no birefringence, heat deformation resistance temperature 107°C, and good shape stability.

比較例１ この比較例では、光学式情報記録体として一般に用いら
れているポリメチルメタクリレート（協和ガス化学社製
　バラベラ）　　ＦｌｏｏＯ）を用いて、実施例１と全
く同様にして射出成形し、円板を得た。Comparative Example 1 In this comparative example, injection molding was performed in exactly the same manner as in Example 1 using polymethyl methacrylate (FlooO, manufactured by Kyowa Gas Chemical Co., Ltd.), which is commonly used as an optical information recording medium, to form a disc. I got it.

この円板について実施例１と全く同様にして調べたとこ
ろ、反りが２．１鱈、吸水率が１．２％。When this disk was examined in exactly the same manner as in Example 1, the warpage was 2.1% and the water absorption rate was 1.2%.

全光線透過率が９１９％、曇価が０．８％、複屈折はな
く、耐熱変形温度が８２℃で、吸水率及び耐熱性におい
て上記実施例のものよりも劣ることが判明した。It was found that the total light transmittance was 919%, the haze value was 0.8%, there was no birefringence, and the heat deformation resistance temperature was 82°C, which was inferior to those of the above examples in terms of water absorption and heat resistance.

Claims (1)

【特許請求の範囲】[Claims] 透明な合成樹脂板を基盤とする情報記録体において、上
記合成樹脂が、シクロヘキサノンを用いてポリビニルア
ルコールを６５モル％以上にアセタール化して得られた
アセタール化物で、実質的に構成されていることを特徴
とする、光学式情報記録体。In an information recording medium based on a transparent synthetic resin plate, the synthetic resin is substantially composed of an acetalized product obtained by acetalizing polyvinyl alcohol to 65 mol% or more using cyclohexanone. Optical information recording medium.
JP59123305A 1984-06-15 1984-06-15 Optical information-recording medium Granted JPS612596A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59123305A JPS612596A (en) 1984-06-15 1984-06-15 Optical information-recording medium

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59123305A JPS612596A (en) 1984-06-15 1984-06-15 Optical information-recording medium

Publications (2)

Publication Number Publication Date
JPS612596A true JPS612596A (en) 1986-01-08
JPH0318259B2 JPH0318259B2 (en) 1991-03-12

Family

ID=14857247

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59123305A Granted JPS612596A (en) 1984-06-15 1984-06-15 Optical information-recording medium

Country Status (1)

Country Link
JP (1) JPS612596A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62143638U (en) * 1986-03-03 1987-09-10
JPS6384085U (en) * 1986-11-21 1988-06-02
JPH0535669U (en) * 1991-07-08 1993-05-14 名糖株式会社 Kraft paper bag with gazette
JPH0680652U (en) * 1993-04-30 1994-11-15 三和紙工株式会社 Opening sealing structure of powder bag

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62143638U (en) * 1986-03-03 1987-09-10
JPH0544292Y2 (en) * 1986-03-03 1993-11-10
JPS6384085U (en) * 1986-11-21 1988-06-02
JPH0535669U (en) * 1991-07-08 1993-05-14 名糖株式会社 Kraft paper bag with gazette
JPH0680652U (en) * 1993-04-30 1994-11-15 三和紙工株式会社 Opening sealing structure of powder bag

Also Published As

Publication number Publication date
JPH0318259B2 (en) 1991-03-12

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