JPS6252363B2 - - Google Patents
Info
- Publication number
- JPS6252363B2 JPS6252363B2 JP18225381A JP18225381A JPS6252363B2 JP S6252363 B2 JPS6252363 B2 JP S6252363B2 JP 18225381 A JP18225381 A JP 18225381A JP 18225381 A JP18225381 A JP 18225381A JP S6252363 B2 JPS6252363 B2 JP S6252363B2
- Authority
- JP
- Japan
- Prior art keywords
- copolymer
- vinyl
- vinyl chloride
- weight
- magnetic powder
- 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.)
- Expired
Links
- 229920001577 copolymer Polymers 0.000 claims description 26
- 239000006247 magnetic powder Substances 0.000 claims description 22
- 238000010521 absorption reaction Methods 0.000 claims description 18
- 239000000178 monomer Substances 0.000 claims description 13
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 claims description 10
- 239000011230 binding agent Substances 0.000 claims description 9
- -1 alkyl carboxylic acid ester Chemical class 0.000 claims description 8
- 229920005989 resin Polymers 0.000 claims description 6
- 239000011347 resin Substances 0.000 claims description 6
- 150000002148 esters Chemical class 0.000 claims description 5
- 238000000862 absorption spectrum Methods 0.000 claims description 4
- 229920002803 thermoplastic polyurethane Polymers 0.000 claims description 2
- 229920001971 elastomer Polymers 0.000 claims 3
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical group C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 claims 1
- 125000005670 ethenylalkyl group Chemical group 0.000 claims 1
- 229920002554 vinyl polymer Polymers 0.000 description 19
- 229910001566 austenite Inorganic materials 0.000 description 10
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 10
- 229920002433 Vinyl chloride-vinyl acetate copolymer Polymers 0.000 description 8
- 239000000654 additive Substances 0.000 description 8
- 238000003490 calendering Methods 0.000 description 8
- VZCYOOQTPOCHFL-UHFFFAOYSA-N trans-butenedioic acid Natural products OC(=O)C=CC(O)=O VZCYOOQTPOCHFL-UHFFFAOYSA-N 0.000 description 8
- 230000000996 additive effect Effects 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 7
- OFOBLEOULBTSOW-UHFFFAOYSA-N Propanedioic acid Natural products OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 6
- 230000009477 glass transition Effects 0.000 description 6
- VZCYOOQTPOCHFL-UPHRSURJSA-N maleic acid Chemical compound OC(=O)\C=C/C(O)=O VZCYOOQTPOCHFL-UPHRSURJSA-N 0.000 description 6
- 239000011976 maleic acid Substances 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 229920005749 polyurethane resin Polymers 0.000 description 6
- 239000003795 chemical substances by application Substances 0.000 description 5
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- 238000005498 polishing Methods 0.000 description 5
- 229920001567 vinyl ester resin Polymers 0.000 description 5
- VZCYOOQTPOCHFL-OWOJBTEDSA-N Fumaric acid Chemical compound OC(=O)\C=C\C(O)=O VZCYOOQTPOCHFL-OWOJBTEDSA-N 0.000 description 4
- 229920000459 Nitrile rubber Polymers 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 3
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 2
- 235000014113 dietary fatty acids Nutrition 0.000 description 2
- 239000002270 dispersing agent Substances 0.000 description 2
- UKMSUNONTOPOIO-UHFFFAOYSA-N docosanoic acid Chemical compound CCCCCCCCCCCCCCCCCCCCCC(O)=O UKMSUNONTOPOIO-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000194 fatty acid Substances 0.000 description 2
- 229930195729 fatty acid Natural products 0.000 description 2
- 239000001530 fumaric acid Substances 0.000 description 2
- IPCSVZSSVZVIGE-UHFFFAOYSA-N hexadecanoic acid Chemical compound CCCCCCCCCCCCCCCC(O)=O IPCSVZSSVZVIGE-UHFFFAOYSA-N 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- JNYAEWCLZODPBN-JGWLITMVSA-N (2r,3r,4s)-2-[(1r)-1,2-dihydroxyethyl]oxolane-3,4-diol Chemical class OC[C@@H](O)[C@H]1OC[C@H](O)[C@H]1O JNYAEWCLZODPBN-JGWLITMVSA-N 0.000 description 1
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 235000021357 Behenic acid Nutrition 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 1
- 235000021314 Palmitic acid Nutrition 0.000 description 1
- 239000004115 Sodium Silicate Substances 0.000 description 1
- 235000021355 Stearic acid Nutrition 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 239000002216 antistatic agent Substances 0.000 description 1
- 229940116226 behenic acid Drugs 0.000 description 1
- HGAZMNJKRQFZKS-UHFFFAOYSA-N chloroethene;ethenyl acetate Chemical compound ClC=C.CC(=O)OC=C HGAZMNJKRQFZKS-UHFFFAOYSA-N 0.000 description 1
- UIWXSTHGICQLQT-UHFFFAOYSA-N ethenyl propanoate Chemical compound CCC(=O)OC=C UIWXSTHGICQLQT-UHFFFAOYSA-N 0.000 description 1
- 150000004665 fatty acids Chemical class 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- WQEPLUUGTLDZJY-UHFFFAOYSA-N n-Pentadecanoic acid Natural products CCCCCCCCCCCCCCC(O)=O WQEPLUUGTLDZJY-UHFFFAOYSA-N 0.000 description 1
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 150000003242 quaternary ammonium salts Chemical class 0.000 description 1
- 238000007127 saponification reaction Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 229920002545 silicone oil Polymers 0.000 description 1
- 239000000344 soap Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000008117 stearic acid Substances 0.000 description 1
- 229920006027 ternary co-polymer Polymers 0.000 description 1
- 229920001897 terpolymer Polymers 0.000 description 1
- TUNFSRHWOTWDNC-HKGQFRNVSA-N tetradecanoic acid Chemical compound CCCCCCCCCCCCC[14C](O)=O TUNFSRHWOTWDNC-HKGQFRNVSA-N 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
- G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
- G11B5/702—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the bonding agent
Description
本発明は磁気記録媒体に関し、特に表面性が向
上し、カレンダー加工が容易で、高域感度が向上
し、さらに高温高湿時の保存性と走行性が良好な
磁気記録媒体に関する。
従来から塩化ビニル―酢酸ビニル―ビニルアル
コール共重合体が磁気テープバインダー用樹脂と
して広く使用されてきた。
この塩化ビニル―酢酸ビニル―ビニルアルコー
ル共重合体としては米国UCC社の商品名
“VAGH”が代表的なもので、日本のメーカーも
塩化ビニル―酢酸ビニル―ビニルアルコールの比
率を91％―３％―６％に統一して生産している。
この共重合体は、比較的安価であること、溶剤に
溶け易いこと、他の樹脂との相容性が良いこと、
またその分子中にある水酸基のために磁性粉末と
良く親和してその分散性を良くすること等の利点
を有し、特に分散性が良いために配向度、最大残
留磁束密度などの優れた磁気特性をもたらしてい
る。しかし近年になつて磁性粉が微粒子化されこ
れらの樹脂でもかならずしも分散性が満足出来な
くなりこの型の共重体において水酸基の量を増加
した方向で検討した結果、分散性には、赤外吸収
スペクトルのOH／CHの吸収比で0.7以上になる
までOHを導入すると適当である事は明確となつ
た。しかしこの水酸基の量を増大した共重合体は
そのガラス転移温度が70℃位と高く、そのために
表面加工しにくく特にカレンダー加工性が悪く、
従つて磁性層のカレンダー加工後の表面性が向上
しにくいという欠点がある。従つて、この分散性
を改良した塩化ビニル―酢酸ビニル―ビニルアル
コール共重合体よりなるバインダーは、磁性層に
おける磁性粉末の分散性及び磁性層表面の平滑鏡
面性の両面から見れば、必ずしも満足できるもの
と言うことができない。即ち、塩化ビニル―酢酸
ビニル―ビニルアルコール共重合体は磁性粉末の
分散性の面では良好であると言えるけれども、磁
性層のカレンダー加工後の表面性が劣るという欠
点を有する。
この点にかんがみ、本発明者等は先きにバイン
ダーとして上記塩化ビニル―酢酸ビニル―ビニル
アルコール共重合体に対してガラス転移点を65℃
以下に下げた樹脂成分を混合させることにより、
磁性粉末の分散性を損わないで塗膜の表面性を向
上し、カレンダー加工後の光沢度の向上をしうる
ことを見出した（特願昭56−94016号等）。ところ
が今度は、ガラス転移点が低いため、高温高湿の
条件下での保存性及び走行性が低下することが分
つた。
従つて、本発明は上記の欠点のない磁気記録媒
体を提供することを目的とする。
本発明は、塩化ビニル、アルキルカルボン酸ビ
ニルエステル、塩化ビニルと共重合可能な単量
体、及びアルキルカルボン酸ビニルエステルのケ
ン化物を構成成分とする共重合体であつて、その
赤外吸収スペクトルのOH／CH吸収比が0.2〜0.7
のものを使用することによつて、カレンダー加工
後の光沢度の向上、さらに高温高湿時の磁気テー
プの保存、走行性が安定化できた。これはケン化
物を少めにおさえることによりガラス転移点の上
昇をおさえると共に、ケン化物の減少で磁性粉の
分散性が低下するのを塩化ビニルと共重合可能な
単量体で補うことにより達成されたものである。
本発明で使用される共重合体は種々の方法で製
造しうる。例えば塩化ビニル―アルキルカルボン
酸ビニル共重合体をケン化することにより塩化ビ
ニル―アルキルカルボン酸ビニル共重合体のケン
化物とし、さらに上記ケン化した共重合体に塩化
ビニルと共重合しうる単量体を反応させるなどで
ある。他の任意の方法によることも可能である。
本発明で使用されるアルキルカルボン酸ビニル
エステル及びそのケン化物としては酢酸ビニル、
プロピオン酸ビニル、バーサチツク酸ビニル、及
びそのケン化物等がある。また本発明で使用され
る塩化ビニルと共重合可能な単量体としては、マ
レイン酸、フマール酸、メタクリル酸、それらの
エステル類、アクリル酸及びそのエステル類があ
る。また上記のケン化（典型的には塩化ビニル―
アルキルカルボン酸ビニル共重合体のケン化）の
際には、ガラス転移点の低下を行う一方で磁性粉
の分散性の低下への影響を或る程度おさえる必要
から前述のように赤外吸収スペクトルのOH／
CH吸収比を0.2〜0.7にする必要がある。なおこ
こで示す赤外吸収のOH吸収は3450cm-1、CH吸収
は2930cm-1であり、OH／CHはその強度比であ
る。
上記共重合体を構成する単量体は、塩化ビニル
50〜90重量％、アルキルカルボン酸ビニルエステ
ル５〜40重量％、塩化ビニルと共重合可能な他の
単量体1.5〜5.0重量％、および残部アルキルカル
ボン酸ビニルエステルケン化物4.0〜10.0重量％
の範囲で用いれば所期の効果が達成できることが
分つた。
本発明の第一の具体的例においては、かかる共
重合体とアクリロニトリルブタジエンゴムとより
なるバインダーで磁性粉末を支持体上に固着して
なる磁気記録媒体が提供される。第二の具体例に
おいてはかかる共重合体とウレタン樹脂とよりな
るバインダーで磁性粉末を支持体上に固着してな
る磁気記録媒体が提供される。
本発明に使用可能なポリウレタン樹脂として
は、その代表的なものは、日本ポリウレタン社製
のニツポラン2304、ニツポラン2301、ニツポラン
3022、ニツポラン5033、パラプレン22S（いずれ
も商品名）など、米国グツドリツチ社製のエステ
ン5701、エステン5702、エステン5703、エステン
5711、エステン5715、エステン5717（いずれも商
品名）、大日本インキ社製のクリスボン4216、ク
リスボン4407、クリスボン7209、Ｔ―5000、Ｔ―
5009、Ｔ―5010、Ｔ―5102、Ｔ―5205、5260MT
（いずれも商品名）、タイセル化学社製のEA―
254、EA―255、EA―256、プラクセル205、プラ
クセル208、プラクセル212、プラクセル230、プ
ラクセル240、プラクセル303、プラクセル305、
プラクセル308、プラクセル320、プラクセル330
（いずれも商品名）、武田薬品工業製のＴ―1040、
E550（いずれも商品名）等がある。又ニトリル
ゴムとしては日本ゼオン社製のハイカ―1042、ハ
イカ―1052、ハイカ―1072、ハイカ―1312、ハイ
カ―1432、ハイカ―1043、ハイカ―1053（いずれ
も商品名）等がある。
以下、比較例と共に実施例を挙げて本発明を例
示する。
比較例 １
塩化ビニル―酢酸ビニル系共重合体注(1)
24ｇ〜36ｇ
（OH／CH吸収比：０，0.3，0.5，0.7，0.9）
ポリウレタン樹脂（ニツポラン＃5033）
４〜16ｇ
添加剤 ０ｇ〜20ｇ
磁性粉（γ―Fe2O3） 120〜200ｇ
比較例 ２
塩化ビニル―プロピオン酸ビニル系共重合体注
(1) 16ｇ〜36ｇ
（OH／CH吸収比：０，0.2，0.4，0.6，0.8）
アクリロニトリルブタジエンゴム（ハイカ―
1312） ４〜24ｇ
添加剤 ０〜20ｇ
研マ剤 １ｇ〜５ｇ
磁性粉（γ―Fe2O3） 120〜200ｇ
比較例 ３
塩化ビニル―酢酸ビニル系共重合体注(1)
８ｇ〜18ｇ
（OH／CH吸収比：0.3，0.5，0.7，0.8，0.9）
塩化ビニル―酢酸ビニル系共重合体注(2)
（単量体（マレイン酸）量：０，0.5，1.0，
1.5，2.0，2.5，3.0（％）） ８ｇ〜18ｇ
ポリウレタン樹脂（ニツポラン＃2304）
４〜24ｇ
添加剤 ０〜40ｇ
磁性粉（γ―Fe2O3） 120〜200ｇ
研マ剤 ０〜10ｇ
注(1) 括弧内の吸収比で示されるケン化物を含む
３元共重合体である。
(2) 括弧内のマレイン酸量を含む３元共重合体
である。
実施例 １
塩化ビニル―酢酸ビニル系共重合体注(3)
（OH／CH吸収比：０，0.2，0.4，0.5，0.6，
0.7，0.8）
（単量体（マレイン酸）量：０，0.5，1.0，
1.5，2.0，2.5，3.0（％）） 16ｇ〜36ｇ
ポリウレタン樹脂（ニツポラン＃5033）
４ｇ〜24ｇ
添加剤 ０〜20ｇ
研マ剤 ０〜20ｇ
磁性粉末（γ―Fe2O3） 120〜200ｇ
実施例 ２
磁性粉末（Co，γ―Fe2O3）に変更、あとは実
施例１と同組成
実施例 ３
塩化ビニル―プロピオン酸ビニル系共重合体注
(3)
（OH／CH吸収比：０，0.2，0.4，0.5，0.6，
0.7，0.8）
（単量体（フマール酸）量：０，0.5，1.0，
1.5，2.0，2.5，3.0（％）） 16ｇ〜36ｇ
アクリロニトリルブタジエンゴム（ニツポール
1432） ４ｇ〜24ｇ
添加剤 ０〜40ｇ
研マ剤 ０〜20ｇ
磁性粉末（γ―Fe2O3） 120〜200ｇ
実施例 ４
塩化ビニル―酢酸ビニル系共重合体注(3)
（OH／CH吸収比：０，0.2，0.4，0.5，0.6，
0.7，0.8）
（単量体（マレイン酸）量：０，0.5，1.0，
1.5，2.0，2.5，3.0（％）） 16〜36ｇ
ポリウレタン樹脂（ニツポラン＃2304）
４〜24ｇ
添加剤 ０〜40ｇ
研マ剤 ０〜20ｇ
磁性粉（γ―Fe2O3） 120〜200ｇ
実施例 ５
磁性粉（Co，γ―Fe2O3）に変更、あとは実施
例４と同組成
注(3) 括弧内に示す吸収比で示されるケン化物
と、括弧内に示す単量体量を含む４元共重
合体である。
なお、本発明で用いる共重合体の調製は種々の
成分比の塩化ビニル―酢酸ビニル共重合体から出
発して行うことができる。例えば実施例１の共重
合体は塩化ビニル：酢酸ビニル６：４、８：２及
び85：15（重量比）の塩化ビニル―酢酸ビニル共
重合体に種々の割合でケン化処理及び単量体の共
重合を行うことで調製することができる。
上記比較例１の組成において、磁性塗料をつく
り、それを支持体上に塗布した結果の表面性及び
カレンダー加工後の表面性を第１図に示す。一方
実施例１の組成についても同様に第１図に示す。
ただし図示のものは重量比で表わして磁性粉対樹
脂分の比が４：１、塩化ビニル―酢酸ビニル系共
重合体又は塩化ビニル―プロピオン酸ビニル系共
重合体対ポリウレタン樹脂の比が６：４、添加剤
（ソルビタン酸エステル）対磁性粉３：100、及び
研磨剤なしの組成であつた。図において実線が塗
布後の光沢度で、点線がカレンダー加工後の光沢
度である。このグラフより明確なようにOH／
CH吸収比が増加すれば塗布後の光沢が上昇す
る。又逆にカレンダー後の光沢はガラス転移点の
関係からOH／CH吸収比が多くなると低下して
行く。一方マレイン酸を含む塩化ビニル―酢酸ビ
ニル系バインダーは単にケン化しただけのより塗
布上がりの光沢度がすぐれカレンダー加工後の光
沢度もOH／CH吸収比が0.2〜0.7だとすぐれてい
る。なお比較例３は実施例１と同様な結果をもた
らす。
又比較例３、実施例４、実施例５をそれぞれテ
ープ化後高温高湿下で保存後ワウフラツターを評
価した。それから60℃、80％の環境下で走行した
時の事故率を第１表に示す。この表から明確なよ
うにブレンドした組成は高温高湿下ではテープの
物理特性が悪くなる。
The present invention relates to a magnetic recording medium, and particularly to a magnetic recording medium that has improved surface properties, is easy to calender, has improved high-frequency sensitivity, and has good storage stability and runnability at high temperatures and high humidity. Conventionally, vinyl chloride-vinyl acetate-vinyl alcohol copolymers have been widely used as resins for magnetic tape binders. A typical example of this vinyl chloride-vinyl acetate-vinyl alcohol copolymer is the product name "VAGH" manufactured by UCC in the United States, and Japanese manufacturers also use a vinyl chloride-vinyl acetate-vinyl alcohol ratio of 91% to 3%. -Produced at a uniform rate of 6%.
This copolymer is relatively inexpensive, easily soluble in solvents, and has good compatibility with other resins.
In addition, due to the hydroxyl group in the molecule, it has a good affinity with magnetic powder and improves its dispersibility. It brings characteristics. However, in recent years, magnetic powders have become finer particles, and even these resins cannot always satisfy the dispersibility.As a result of considering increasing the amount of hydroxyl groups in this type of copolymer, we found that the dispersibility is affected by the infrared absorption spectrum. It has become clear that it is appropriate to introduce OH until the OH/CH absorption ratio reaches 0.7 or higher. However, this copolymer with an increased amount of hydroxyl groups has a high glass transition temperature of around 70°C, which makes it difficult to process the surface and has particularly poor calenderability.
Therefore, there is a drawback that it is difficult to improve the surface properties of the magnetic layer after calendering. Therefore, a binder made of a vinyl chloride-vinyl acetate-vinyl alcohol copolymer with improved dispersibility is not necessarily satisfactory in terms of both the dispersibility of the magnetic powder in the magnetic layer and the smooth specularity of the surface of the magnetic layer. I can't say anything. That is, although the vinyl chloride-vinyl acetate-vinyl alcohol copolymer can be said to have good dispersibility of magnetic powder, it has the disadvantage that the surface properties of the magnetic layer after calendering are poor. In view of this point, the present inventors first set the glass transition temperature of the vinyl chloride-vinyl acetate-vinyl alcohol copolymer as a binder to 65°C.
By mixing the resin components listed below,
It has been found that the surface properties of the coating film can be improved without impairing the dispersibility of the magnetic powder, and the gloss after calendering can be improved (Japanese Patent Application No. 56-94016, etc.). However, this time, it was found that because the glass transition point was low, the storage stability and runnability under conditions of high temperature and high humidity deteriorated. It is therefore an object of the present invention to provide a magnetic recording medium that does not have the above-mentioned drawbacks. The present invention relates to a copolymer comprising vinyl chloride, an alkyl carboxylic acid vinyl ester, a monomer copolymerizable with vinyl chloride, and a saponified product of the alkyl carboxylic acid vinyl ester, and the infrared absorption spectrum thereof. OH/CH absorption ratio of 0.2 to 0.7
By using this material, it was possible to improve the gloss after calendering, and to stabilize the storage and running properties of the magnetic tape at high temperatures and high humidity. This was achieved by suppressing the increase in the glass transition point by keeping the amount of saponified substances to a small extent, and by compensating for the decrease in the dispersibility of magnetic powder due to the decrease in saponified substances with a monomer that can be copolymerized with vinyl chloride. It is what was done. The copolymers used in the invention can be produced in a variety of ways. For example, by saponifying a vinyl chloride-vinyl alkylcarboxylate copolymer, it becomes a saponified product of vinyl chloride-vinyl alkylcarboxylate copolymer, and the monomer that can be copolymerized with vinyl chloride is added to the saponified copolymer. For example, it causes the body to react. Any other method is also possible. The alkyl carboxylic acid vinyl ester and its saponified product used in the present invention include vinyl acetate,
Examples include vinyl propionate, vinyl versatate, and saponified products thereof. Monomers copolymerizable with vinyl chloride used in the present invention include maleic acid, fumaric acid, methacrylic acid, esters thereof, and acrylic acid and esters thereof. In addition, the above saponification (typically vinyl chloride-
When saponifying a vinyl alkylcarboxylate copolymer, it is necessary to reduce the glass transition point while also suppressing the effect on the dispersibility of the magnetic powder to some extent, so as mentioned above, the infrared absorption spectrum is OH/
It is necessary to set the CH absorption ratio to 0.2 to 0.7. Note that the OH absorption in the infrared absorption shown here is 3450 cm -1 and the CH absorption is 2930 cm -1 , and OH/CH is their intensity ratio. The monomer constituting the above copolymer is vinyl chloride
50-90% by weight, 5-40% by weight of alkyl carboxylic acid vinyl ester, 1.5-5.0% by weight of other monomers copolymerizable with vinyl chloride, and the remainder 4.0-10.0% by weight of saponified alkyl carboxylic acid vinyl ester.
It was found that the desired effect could be achieved if used within the range of . In a first specific example of the present invention, a magnetic recording medium is provided in which magnetic powder is fixed on a support with a binder made of such a copolymer and acrylonitrile butadiene rubber. In a second specific example, a magnetic recording medium is provided in which magnetic powder is fixed on a support with a binder made of such a copolymer and a urethane resin. Typical polyurethane resins that can be used in the present invention include Nipporan 2304, Nipporan 2301, and Nipporan manufactured by Nippon Polyurethane Co., Ltd.
3022, Nitsuporan 5033, Paraprene 22S (all product names), Esten 5701, Esten 5702, Esten 5703, Esten, etc. manufactured by Gutudoritsu in the United States.
5711, Esten 5715, Esten 5717 (all product names), Krisbon 4216, Krisbon 4407, Krisbon 7209, T-5000, T- manufactured by Dainippon Ink Co., Ltd.
5009, T-5010, T-5102, T-5205, 5260MT
(all product names), EA manufactured by Taisel Kagaku Co., Ltd.
254, EA-255, EA-256, Praxel 205, Praxel 208, Praxel 212, Praxel 230, Praxel 240, Praxel 303, Praxel 305,
Praxel 308, Praxel 320, Praxel 330
(all product names), T-1040 manufactured by Takeda Pharmaceutical Company,
There are E550 (all product names) etc. Examples of nitrile rubber include Hiker 1042, Hiker 1052, Hiker 1072, Hiker 1312, Hiker 1432, Hiker 1043, and Hiker 1053 (all trade names) manufactured by Zeon Corporation. Hereinafter, the present invention will be illustrated by giving examples together with comparative examples. Comparative Example 1 Vinyl chloride-vinyl acetate copolymer Note (1)
24g - 36g (OH/CH absorption ratio: 0, 0.3, 0.5, 0.7, 0.9) Polyurethane resin (Nitsuporan #5033)
4-16g Additive 0g-20g Magnetic powder (γ-Fe 2 O 3 ) 120-200g Comparative example 2 Vinyl chloride-vinyl propionate copolymer note
(1) 16g to 36g (OH/CH absorption ratio: 0, 0.2, 0.4, 0.6, 0.8) Acrylonitrile butadiene rubber (high car
1312) 4-24g Additive 0-20g Polishing agent 1g-5g Magnetic powder (γ-Fe 2 O 3 ) 120-200g Comparative example 3 Vinyl chloride-vinyl acetate copolymer Note (1)
8g to 18g (OH/CH absorption ratio: 0.3, 0.5, 0.7, 0.8, 0.9) Vinyl chloride-vinyl acetate copolymer Note (2) (Monomer (maleic acid) amount: 0, 0.5, 1.0,
1.5, 2.0, 2.5, 3.0 (%)) 8g to 18g Polyurethane resin (Nitsuporan #2304)
4-24g Additive 0-40g Magnetic powder (γ-Fe 2 O 3 ) 120-200g Polishing agent 0-10g Note (1) A ternary copolymer containing a saponified product indicated by the absorption ratio in parentheses. . (2) It is a terpolymer containing the amount of maleic acid in parentheses. Example 1 Vinyl chloride-vinyl acetate copolymer Note (3) (OH/CH absorption ratio: 0, 0.2, 0.4, 0.5, 0.6,
0.7, 0.8) (Monomer (maleic acid) amount: 0, 0.5, 1.0,
1.5, 2.0, 2.5, 3.0 (%)) 16g to 36g Polyurethane resin (Nitsuporan #5033)
4g to 24g Additive 0 to 20g Polishing agent 0 to 20g Magnetic powder (γ-Fe 2 O 3 ) 120 to 200g Example 2 Changed to magnetic powder (Co, γ-Fe 2 O 3 ), followed by Example 1 Same composition example 3 Vinyl chloride-vinyl propionate copolymer Note
(3) (OH/CH absorption ratio: 0, 0.2, 0.4, 0.5, 0.6,
0.7, 0.8) (Monomer (fumaric acid) amount: 0, 0.5, 1.0,
1.5, 2.0, 2.5, 3.0 (%)) 16g to 36g Acrylonitrile butadiene rubber (Nitsupol
1432) 4g to 24g Additive 0 to 40g Polishing agent 0 to 20g Magnetic powder (γ-Fe 2 O 3 ) 120 to 200g Example 4 Vinyl chloride-vinyl acetate copolymer note (3) (OH/CH absorption Ratio: 0, 0.2, 0.4, 0.5, 0.6,
0.7, 0.8) (Monomer (maleic acid) amount: 0, 0.5, 1.0,
1.5, 2.0, 2.5, 3.0 (%)) 16-36g Polyurethane resin (Nitsuporan #2304)
4 to 24 g Additive 0 to 40 g Polishing agent 0 to 20 g Magnetic powder (γ-Fe 2 O 3 ) 120 to 200 g Example 5 Changed to magnetic powder (Co, γ-Fe 2 O 3 ), and the rest was Example 4 Same composition Note (3) This is a quaternary copolymer containing the saponified product shown by the absorption ratio shown in parentheses and the monomer amount shown in parentheses. The copolymers used in the present invention can be prepared starting from vinyl chloride-vinyl acetate copolymers having various component ratios. For example, the copolymer of Example 1 is a vinyl chloride-vinyl acetate copolymer of vinyl chloride:vinyl acetate 6:4, 8:2, and 85:15 (weight ratio), which is saponified and monomers added in various ratios. It can be prepared by copolymerizing. In the composition of Comparative Example 1 above, a magnetic coating material was prepared and the surface properties as a result of coating it on a support and the surface properties after calendering are shown in FIG. On the other hand, the composition of Example 1 is also shown in FIG.
However, in the illustrated case, the ratio of magnetic powder to resin is 4:1 by weight, and the ratio of vinyl chloride-vinyl acetate copolymer or vinyl chloride-vinyl propionate copolymer to polyurethane resin is 6:1. 4. The composition had a ratio of additive (sorbitanic acid ester) to magnetic powder of 3:100, and no abrasive. In the figure, the solid line is the gloss after coating, and the dotted line is the gloss after calendering. As is clearer from this graph, OH/
As the CH absorption ratio increases, the gloss after coating increases. Conversely, the gloss after calendering decreases as the OH/CH absorption ratio increases due to the glass transition point. On the other hand, a vinyl chloride-vinyl acetate binder containing maleic acid has a higher gloss after application than simply saponified binder, and the gloss after calendering is also excellent with an OH/CH absorption ratio of 0.2 to 0.7. Note that Comparative Example 3 yields similar results to Example 1. In addition, after each of Comparative Example 3, Example 4, and Example 5 was formed into a tape and stored under high temperature and high humidity, the wow and flutter was evaluated. Table 1 shows the accident rate when driving in an environment of 60℃ and 80%. As is clear from this table, the blended composition deteriorates the physical properties of the tape under high temperature and high humidity conditions.
【表】
上記の如く磁性粉末としてγ―Fe2O3又はCo被
着γ―Fe2O3を用いて本発明を例示したが、その
他の磁性粉末としてFe3O4、Co被着Fe3O4等と合
金等も同等に使用することができる。また、添加
剤（分散剤、潤滑剤）としては、通常使用される
脂肪酸（ミリスチン酸、パルミチン酸、ステアリ
ン酸、ベヘン酸）、シリコーンオイル（ジメチル
シロキサン）、帯電防止剤（金属石けん、第四級
アンモニウム塩）、分散剤（脂肪酸エステル、燐
酸エステル、ソルビタンエステル、高級アルコー
ル）等を含めることができる。[Table] As described above, the present invention was illustrated using γ-Fe 2 O 3 or Co-coated γ-Fe 2 O 3 as the magnetic powder, but other magnetic powders such as Fe 3 O 4 and Co-coated Fe 3 O 4 etc. and alloys etc. can also be used equally. Additives (dispersants, lubricants) include commonly used fatty acids (myristic acid, palmitic acid, stearic acid, behenic acid), silicone oil (dimethylsiloxane), antistatic agents (metallic soap, quaternary ammonium salts), dispersants (fatty acid esters, phosphoric esters, sorbitan esters, higher alcohols), and the like.
第１図は本発明による磁気記録媒体と従来の磁
気記録媒体との特性の差を表わすものである。
FIG. 1 shows the difference in characteristics between the magnetic recording medium according to the present invention and a conventional magnetic recording medium.
Claims (1)
％と、アルキルカルボン酸ビニルエステル５〜40
重量％と、塩化ビニルと共重合可能な他の単量体
1.5〜5.0重量％と、アルキルカルボン酸エステル
のケン化物4.0〜10.0重量％とを構成成分とする
共重合体であつてその赤外吸収スペクトルの
OH／CH吸収比が0.2〜0.7の共重合体、及びゴム
系バインダーを樹脂成分とし、それに磁性粉末を
分散したものを支持体に固着して成る磁気記録媒
体。 ２ ゴム系バインダーはアクリロニトリルゴム、
ウレタン樹脂又はこれら両者である特許請求の範
囲第１項記載の磁気記録媒体。[Claims] 1. 50 to 90% by weight of vinyl chloride and 5 to 40% of vinyl alkyl carboxylate ester based on the copolymer.
Weight % and other monomers copolymerizable with vinyl chloride
A copolymer consisting of 1.5 to 5.0% by weight and 4.0 to 10.0% by weight of a saponified alkyl carboxylic acid ester, and its infrared absorption spectrum
A magnetic recording medium comprising a copolymer with an OH/CH absorption ratio of 0.2 to 0.7 and a rubber binder as resin components, and a magnetic powder dispersed therein, which is fixed to a support. 2 The rubber binder is acrylonitrile rubber,
The magnetic recording medium according to claim 1, which is a urethane resin or both.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18225381A JPS5885924A (en) | 1981-11-16 | 1981-11-16 | Magnetic recording medium |
| US06/544,804 US4460653A (en) | 1981-11-16 | 1983-10-24 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18225381A JPS5885924A (en) | 1981-11-16 | 1981-11-16 | Magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5885924A JPS5885924A (en) | 1983-05-23 |
| JPS6252363B2 true JPS6252363B2 (en) | 1987-11-05 |
Family
ID=16115019
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18225381A Granted JPS5885924A (en) | 1981-11-16 | 1981-11-16 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5885924A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60137969A (en) * | 1983-12-26 | 1985-07-22 | Nisshin Kagaku Kogyo Kk | Resin for magnetic coating film use and magnetic coating containing the same |
| JPH0619822B2 (en) * | 1984-04-19 | 1994-03-16 | ティーディーケイ株式会社 | Magnetic recording medium |
-
1981
- 1981-11-16 JP JP18225381A patent/JPS5885924A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5885924A (en) | 1983-05-23 |
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