JPH0142297B2 - - Google Patents
Info
- Publication number
- JPH0142297B2 JPH0142297B2 JP56137709A JP13770981A JPH0142297B2 JP H0142297 B2 JPH0142297 B2 JP H0142297B2 JP 56137709 A JP56137709 A JP 56137709A JP 13770981 A JP13770981 A JP 13770981A JP H0142297 B2 JPH0142297 B2 JP H0142297B2
- Authority
- JP
- Japan
- Prior art keywords
- solid material
- water
- graft
- thermoplastic resin
- ionizing radiation
- 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
- 239000011343 solid material Substances 0.000 claims description 23
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 22
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 22
- 229920000578 graft copolymer Polymers 0.000 claims description 17
- 230000005865 ionizing radiation Effects 0.000 claims description 17
- 238000000034 method Methods 0.000 claims description 14
- 229920005992 thermoplastic resin Polymers 0.000 claims description 12
- 238000004519 manufacturing process Methods 0.000 claims description 9
- 238000006116 polymerization reaction Methods 0.000 claims description 8
- 230000001678 irradiating effect Effects 0.000 claims description 5
- 230000001050 lubricating effect Effects 0.000 claims description 4
- 238000004132 cross linking Methods 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 3
- 239000004952 Polyamide Substances 0.000 claims description 2
- 239000004793 Polystyrene Substances 0.000 claims description 2
- 229920000058 polyacrylate Polymers 0.000 claims description 2
- 229920002647 polyamide Polymers 0.000 claims description 2
- 229920000728 polyester Polymers 0.000 claims description 2
- 229920000193 polymethacrylate Polymers 0.000 claims description 2
- 229920000098 polyolefin Polymers 0.000 claims description 2
- 229920002223 polystyrene Polymers 0.000 claims description 2
- 229920002689 polyvinyl acetate Polymers 0.000 claims description 2
- 239000011118 polyvinyl acetate Substances 0.000 claims description 2
- 229920000915 polyvinyl chloride Polymers 0.000 claims description 2
- 239000004800 polyvinyl chloride Substances 0.000 claims description 2
- 229920003051 synthetic elastomer Polymers 0.000 claims description 2
- 239000005061 synthetic rubber Substances 0.000 claims description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 15
- 229920003169 water-soluble polymer Polymers 0.000 description 14
- 239000000463 material Substances 0.000 description 13
- 229920001903 high density polyethylene Polymers 0.000 description 12
- 239000004700 high-density polyethylene Substances 0.000 description 12
- 239000000243 solution Substances 0.000 description 10
- 239000000178 monomer Substances 0.000 description 7
- 238000007334 copolymerization reaction Methods 0.000 description 6
- 210000000056 organ Anatomy 0.000 description 6
- 230000005855 radiation Effects 0.000 description 6
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 5
- 239000007864 aqueous solution Substances 0.000 description 5
- 238000005461 lubrication Methods 0.000 description 5
- 239000012153 distilled water Substances 0.000 description 4
- 229920000642 polymer Polymers 0.000 description 4
- 239000002861 polymer material Substances 0.000 description 4
- GUTLYIVDDKVIGB-OUBTZVSYSA-N Cobalt-60 Chemical compound [60Co] GUTLYIVDDKVIGB-OUBTZVSYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- -1 acrylic ester Chemical class 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 239000013543 active substance Substances 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000010894 electron beam technology Methods 0.000 description 2
- 230000005251 gamma ray Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 239000000017 hydrogel Substances 0.000 description 2
- 239000012567 medical material Substances 0.000 description 2
- 239000012046 mixed solvent Substances 0.000 description 2
- 238000007127 saponification reaction Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- 230000002785 anti-thrombosis Effects 0.000 description 1
- 239000003146 anticoagulant agent Substances 0.000 description 1
- 239000002473 artificial blood Substances 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 210000004204 blood vessel Anatomy 0.000 description 1
- 235000011089 carbon dioxide Nutrition 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000012467 final product Substances 0.000 description 1
- 239000000499 gel Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 229910017053 inorganic salt Inorganic materials 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000002688 persistence Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
- 238000012719 thermal polymerization Methods 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 239000003440 toxic substance Substances 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Landscapes
- Treatments Of Macromolecular Shaped Articles (AREA)
- Graft Or Block Polymers (AREA)
- Other Resins Obtained By Reactions Not Involving Carbon-To-Carbon Unsaturated Bonds (AREA)
Description
【発明の詳細な説明】
本発明は潤滑特性のすぐれたグラフト共重合物
の製造方法に関し、さらに詳しくは高分子ヒドロ
ゲルを用いた人工関節、人工血管等の人造器官素
材、外科手術用縫合糸、湿布帯等の外科医療用素
材あるいは機械の軸受等の摺動部材などとして特
にすぐれた水性潤滑特性を有するグラフト共重合
物の効率のよい製造方法に関する。
最近、人造器官素材あるいは外科医療用素材と
して様々な高分子化合物を用いることが提案され
ている。例えば、ポリビニルアルコールとビニル
モノマーのラジカル重合物を医療用素材として用
いること（特開昭49−48190号公報）、抗血栓性人
造器官材料として高分子材料にスチレンをグラフ
ト共重合させたもの（特公昭55−4414号公報）や
高分子材料に酢酸ビニルをグラフト共重合させた
後、ケン化してポリビニルアルコールに変化させ
たもの（特公昭55−4415号公報）、あるいは高分
子材料にアクリル酸エステルをグラフト共重合さ
せたもの（特公昭50−32554号公報）などを用い
ることが提案されている。また単量体をグラフト
重合したポリビニルアルコールの含水ゲルに作用
物質を含浸させて持続性の改善された湿布薬等の
活性体を製造することも知られている（特開昭52
−56148号公報）。
しかしながら、これらはいずれもモノマーを原
料として用い、活性線グラフト反応させたもので
あるため、最終生成物であるグラフト共重合物中
に毒性を有する未反応モノマーが含有されてお
り、この未反応モノマーを取除くのに多大な労力
を要し、生産性が極めて低いという欠点があつ
た。
さらに、軸受等の機械部材の摺動部に樹脂をバ
インダーとして潤滑性粒子を保持させた潤滑部品
が研究されている（特開昭55−145797号公報、特
開昭55−106230号公報）が、これらは水性潤滑特
性において未だ十分満足しうるものではない。
そのほか、活性線を用いたグラフト共重合法と
しては、特開昭50−32287号公報、特公昭47−
45592号公報、特公昭45−25107号公報に開示され
た方法などが知られている。しかし、これらの方
法は、活性線放射とラジカル熱重合を組合せたも
のであつて、加熱処理や後処理に問題があり、特
に反応物でのモノマーの取扱いが煩雑でりあり、
作業性ならびに生産性に問題があつた。
そこで本発明者らは、上記従来技術の欠点を克
服し、人造器官素材、外科医療用素材として、あ
るいは軸受等の摺動部材としてすぐれた材料の効
率のよい製造方法を開発すべく鋭意研究を重ね
た。その結果、特定の熱可塑性樹脂に水溶性高分
子材料をグラフト共重合させることにより目的と
する材料を製造するにあたつて熱可塑性樹脂に、
予め前処理としての電離性放射線照射を行なうと
共に、該熱可塑性樹脂を水溶性高分子を溶解した
溶液に浸漬して電離性放射線照射によりグラフト
共重合を行なうことによつて効率よく製造できる
ことを見出した。本発明はかかる知見に基いて完
成したものである。
すなわち本発明は、架橋重合可能でかつ非水溶
性の熱可塑性樹脂よりなる固体材料の少なくとも
一部に、前処理としての電離性放射線照射を行な
い、次いで該固体材料をポリビニルアルコールを
溶解した溶液中に浸漬し、さらに浸漬したまま電
離性放射線照射を行なつて前記ポリビニルアルコ
ールを前記固体材料の表面にグラフト共重合させ
ることを特徴とする潤滑特性のすぐれたグラフト
共重合物の製造方法を提供するものである。
本発明に用いる固体材料は、架橋重合可能でか
つ非水溶性の熱可塑性樹脂であるが、このような
ものとしては各種のものが考えられるが、例えば
ポリスチレン、ポリオレフイン（ポリエチレン、
ポリプロピレン等）、ポリアミド、ポリ塩化ビニ
ル、合成ゴム、ポリ酢酸ビニル、ポリエステル、
ポリアクリレート、ポリメタアクリレートあるい
はこれらの混合物などをあげることができる。
本発明の方法で得られるグラフト共重合物は、
上述の熱可塑性樹脂よりなる固体材料の表面の一
部乃至全部に、上述の水溶性高分子であるポリビ
ニルアルコールをグラフト共重合させてなるもの
である。ここで熱可塑性樹脂よりなる固体材料の
形状は様々なものがあり、使用目的に応じて板
状、管状、繊維状などとすることができる。ま
た、この固体材料にグラフト共重合した水溶性高
分子は、重合によつて非水溶性のものとなり、固
体材料の表面を被覆することとなるが、この水溶
性高分子がグラフト共重合して形成したグラフト
物の膜厚は、通常0.1〜500μｍが好ましい。さら
に本発明のグラフト共重合物における上記グラフ
ト物によるグラフト率は、特に制限はないが、通
常は0.1〜200％の範囲で適宜選定すればよい。
本発明の方法によれば、まず上述の熱可塑性樹
脂よりなる固体材料の表面の一部乃至全部、つま
りグラフト共重合させたい部分に、前処理として
電離性放射線照射を行なう。この電離性放射線照
射にあたつては、固体材料を、活性線を照射した
際に生成するラジカルを安定的に維持できる雰囲
気下に設置することが好ましい。具体的には、真
空中が最も好ましいが、窒素ガス雰囲気下、炭酸
ガス雰囲気下など、さらには空気中、酸素ガス、
オゾンガス雰囲気下でもよい。また温度は常温で
よいが、活性線の照射によつて発熱する場合に
は、氷等にて冷却しながら照射を行なうことが好
ましい。なお、電離性放射線としてはα線、β
線、γ線、Ｘ線あるいは加速電子線などがある
が、特に、高エネルギー放射線、例えばコバルト
60からのγ線や電子線が好適である。また電離性
放射線の照射量は、適宜定めればよいが、一般的
には上記固体材料に水溶性高分子がグラフト共重
合して、架橋ゲルとしての形状を保つのに十分な
量であればよく、照射すべき固体材料の種類によ
つて異なるが、２〜60メガラド程度が好ましい。
本発明の方法では、上記固体材料を上述の如く
前処理した後、上記した水溶性高分子を溶解した
溶液中に浸漬する。ここで溶液の溶剤としては、
上記水溶性高分子を溶解しうるものであると共
に、この水溶性高分子を固体材料にグラフト共重
合させて得られるグラフト共重合物から水洗によ
つて容易に除去できるものが好ましい。通常は水
を用いればよいが、場合によつては水溶性高分子
を溶解する有機溶剤および無機塩の水溶液あるい
はこれらの混合溶剤もしくはそれらと水との混合
溶剤などを用いることもできる。また、この溶液
中の水溶性高分子の濃度は、電離性放射線照射に
よつて分解しない範囲がよく、通常は１％以上、
好ましくは５〜20％とすべきである。なお、この
水溶性高分子としては、前述したようにポリビニ
ルアルコールを用いる。このポリビニルアルコー
ルは、グラフト共重合反応を阻害しないものであ
ればどのようなものでもよく、完全ケン化物、部
分ケン化物のいずれでもよいが、一般にはケン化
度の高いものの方が好ましい。また、ポリビニル
アルコールの分子量や重合度についても特に制限
はないが、分子量の大きいものほど、緻密な膜が
できて好ましく、重合度はグラフト共重合の反応
効率の点から平均重合度50以上のものが好まし
い。
続いて本発明の方法では、固体材料を水溶性高
分子を溶解した溶液中に浸漬した状態で電離性放
射線照射を行なう。この際に用いる電離性放射線
は前述したものと同じものでよい。また照射線量
は、各種条件によつて異なるが、通常は２〜40メ
ガラドで十分である。
本発明の方法によれば、前処理として予め固体
材料に電離性放射線照射を行なつているため、該
固体材料を溶液中で水溶性高分子とグラフト共重
合させるにあたつて、共重合反応が速やかにかつ
所望する部分に正確に進行し、目的とするグラフ
ト共重合物を効率よく製造することができる。
なお、本発明の方法にしたがつて製造したグラ
フト共重合物を、溶液中から引上げて水洗すれ
ば、グラフト共重合物表面および内部に付着して
いる未反応の水溶性高分子および溶剤は完全に洗
い落とされ、その後室温にて乾燥すれば不純物の
ないすぐれた物性のグラフト共重合物となる。
以上の如く、本発明の方法は、未反応モノマー
の複雑な除去工程を必要とせず、極めて製造効率
の高いものであると同時に、得られるグラフト共
重合物は、従来にない高い摩擦特性ならびに耐久
性の大きい摩擦特性を有し、しかも未反応モノマ
ー等の毒物を含有しないため、人造器官素材、外
科医療用素材等の高度の耐久性を要求される各種
医療用素材に有効に用いられる。また、このグラ
フト共重合物は、水性潤滑特性にもすぐれている
ため、高度の耐久性を要求される軸受等の機械用
摺動部材として用いることができ、しかもこの場
合潤滑剤として、水あるいは水とグリコールとの
混合物でよく、従来のように、引火性等の危険が
あり、かつ高価な潤滑油を必要とせず、極めて安
全でかつ作業性の高いものである。
従つて本発明のグラフト共重合物の製造方法
は、各種医療用器官、機械用摺動部材ならびにそ
の製造分野において有効かつ幅広く利用される。
次に本発明の実施例を示す。
実施例 １〜７
メルトインデツクス0.3ｇ／10分、密度0.965
ｇ／cm3の高密度ポリエチレンを用いて厚さ21μｍ
のフイルム（試料１）を成形し、このフイルムか
ら中央部に直径12.5mmの円形にくりぬき部分を有
する直径53mmの円板を切りとり、この円板を第１
図に示す容器内に炭酸ガス雰囲気下に設置し、次
いでドライアイスで冷却しながらコバルト60線源
を用いて、γ線を2.64メガラドの線量で照射した
（前照射）。
上記前処理としてのγ線照射後、円板を容器か
ら取り出し、続いてこの円板を平均重合度490の
ポリビニルアルコールの水溶液中に第２図に示す
ように浸漬し、コバルト60線源を用いてγ線を第
１表に示す線量で照射した（後照射）。
照射後、試料１を蒸留水で洗浄し、この試料１
をさらにメタノールで洗浄した後、室温で乾燥し
て、高密度ポリエチレン（HDPE）上のポリビニ
ルアルコール（PVA）のグラフト膜の固有粘度
〔η〕（dl／ｇ）、重合度、グラフト率（％）、膜厚
（μｍ）を測定した。結果を第１表に示す。なお、
固有粘度〔η〕（dl／ｇ）の測定は、ウベローデ
型粘度計を用い、恒温槽中で30℃にて溶液粘度を
測定した。また重合度Ｐは中島らの関係式（中島
章夫、高分子化学、６，460（1949）〔η〕水30℃＝
7.50×10-4×P0.64により算出した。グラフト率は
次式に従つて求めた。
グラフト率（％）＝PVAをグラフトしたHDPE板の重
量−HDPE板の重量／HDPE板の重量×100
一方、グラフト膜厚はPVA濃度Ｃ（ｇ／100
cm3）、PVAグラフト量Ｇ（ｇ／cm3）、水溶液の比重
１として、次の式により求めた。
グラフト膜厚（μｍ）＝Ｇ／Ｃ×106
なおここでPVAグラフト量Ｇは、次の如く定
義した。
Ｇ（ｇ／cm2）＝PVAをグラフトしたHDPE板の重量−
HDPE板の重量／HDPE板両面の面積
比較例 １および２
前照射をしなかつたこと以外は、実施例１と同
一の試料を用い、同様の条件で評価した。その結
果を第１表に示す。
実施例８および比較例３
実施例１〜７と同じHDPEを用いて厚さ５mmの
シート（試料２）を成形し、これを実施例１〜７
と同様にして前処理としてのγ線照射を行なつ
た。その後、この試料２を実施例１〜７と同様に
してPVA水溶液（濃度15wt％）中に浸漬し、コ
バルト60線源を用いてγ線を2.64メガラドの線量
で照射した。
照射後、試料２を蒸留水で十分に洗浄し、次い
でこの試料２を蒸留水中にて、第３図に示すBall
―on―Disk型摩擦測定器を用いて摩擦係数の測
定を行なつた。Ballは3/16インチのスチールBall
（SUJ―２）を用い、すべり速度18.8cm／秒、荷
重0.5，0.7，1.0Kgｆで行なつた。得られた摩擦係
数の経時変化を第４図に示す。
また比較例３としてPVAをグラフトしていな
いHDPE板を用いて、上記の如く蒸留水中にて摩
擦係数の測定を行なつた。結果を第５図に示す。
【表】DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a graft copolymer with excellent lubrication properties, and more specifically, it relates to a method for producing a graft copolymer having excellent lubrication properties, and more specifically to artificial joints using polymer hydrogel, artificial organ materials such as artificial blood vessels, surgical sutures, The present invention relates to an efficient method for producing a graft copolymer having particularly excellent aqueous lubrication properties for use as surgical materials such as compresses or sliding members such as machine bearings. Recently, it has been proposed to use various polymer compounds as materials for artificial organs or surgical materials. For example, radical polymers of polyvinyl alcohol and vinyl monomers are used as medical materials (Japanese Patent Application Laid-Open No. 49-48190), and polymer materials grafted with styrene are used as antithrombotic artificial organ materials (Japanese Patent Laid-Open Publication No. 49-48190). (Japanese Patent Publication No. 55-4414), graft copolymerization of vinyl acetate onto a polymer material and then saponification to convert it into polyvinyl alcohol (Japanese Patent Publication No. 55-4415), or acrylic ester into a polymer material. It has been proposed to use a graft copolymerized product (Japanese Patent Publication No. 50-32554). It is also known to produce active substances such as poultices with improved persistence by impregnating a hydrogel of polyvinyl alcohol obtained by graft-polymerizing monomers with an active substance (Japanese Patent Application Laid-Open No. 52-2001).
−56148). However, since all of these use monomers as raw materials and undergo active ray graft reaction, the final product, the graft copolymer, contains toxic unreacted monomers. The drawback was that it required a great deal of effort to remove and the productivity was extremely low. Furthermore, lubricating parts in which lubricating particles are held in the sliding parts of mechanical parts such as bearings using resin as a binder are being researched (Japanese Patent Laid-Open Nos. 145797-1982 and 106230-1980). , these are still not fully satisfactory in water-based lubrication properties. In addition, as a graft copolymerization method using active rays, Japanese Patent Application Laid-open No. 32287/1983 and Japanese Patent Publication No. 47/1983
Methods disclosed in Japanese Patent Publication No. 45592 and Japanese Patent Publication No. 45-25107 are known. However, these methods combine actinic radiation and radical thermal polymerization, and there are problems with heat treatment and post-treatment, and in particular, the handling of monomers as reactants is complicated.
There were problems with workability and productivity. Therefore, the present inventors have conducted intensive research in order to overcome the drawbacks of the above-mentioned conventional techniques and to develop an efficient manufacturing method for materials that are excellent as materials for artificial organs, surgical materials, or sliding members such as bearings. Layered. As a result, when producing a desired material by graft copolymerizing a water-soluble polymer material onto a specific thermoplastic resin,
We have discovered that it is possible to efficiently produce the thermoplastic resin by irradiating it with ionizing radiation as a pretreatment and by immersing the thermoplastic resin in a solution containing a water-soluble polymer and performing graft copolymerization by irradiating it with ionizing radiation. Ta. The present invention was completed based on this knowledge. That is, in the present invention, at least a portion of a solid material made of a water-insoluble thermoplastic resin capable of crosslinking polymerization is irradiated with ionizing radiation as a pretreatment, and then the solid material is placed in a solution containing polyvinyl alcohol. Provided is a method for producing a graft copolymer having excellent lubricating properties, characterized in that the polyvinyl alcohol is graft copolymerized on the surface of the solid material by immersing the solid material in water and irradiating it with ionizing radiation while immersed. It is something. The solid material used in the present invention is a water-insoluble thermoplastic resin that can be cross-linked and polymerized. Various types of such materials can be considered, such as polystyrene, polyolefin (polyethylene,
polypropylene, etc.), polyamide, polyvinyl chloride, synthetic rubber, polyvinyl acetate, polyester,
Examples include polyacrylate, polymethacrylate, and mixtures thereof. The graft copolymer obtained by the method of the present invention is
It is made by graft copolymerizing polyvinyl alcohol, which is the water-soluble polymer described above, on a part or all of the surface of the solid material made of the above-mentioned thermoplastic resin. There are various shapes of the solid material made of thermoplastic resin, and it can be shaped into a plate, a tube, a fiber, etc. depending on the purpose of use. In addition, the water-soluble polymer graft-copolymerized onto this solid material becomes water-insoluble through polymerization and coats the surface of the solid material. The thickness of the formed graft is usually preferably 0.1 to 500 μm. Furthermore, the grafting rate of the above-mentioned grafted material in the graft copolymer of the present invention is not particularly limited, but it may normally be appropriately selected within the range of 0.1 to 200%. According to the method of the present invention, first, part or all of the surface of the solid material made of the above-mentioned thermoplastic resin, that is, the part to be graft copolymerized, is irradiated with ionizing radiation as a pretreatment. When irradiating the solid material with ionizing radiation, it is preferable to place the solid material in an atmosphere that can stably maintain radicals generated when irradiated with active radiation. Specifically, it is most preferable to be in a vacuum, but also in a nitrogen gas atmosphere, a carbon dioxide gas atmosphere, and even in the air, oxygen gas,
An ozone gas atmosphere may be used. Although the temperature may be room temperature, if irradiation with actinic rays generates heat, it is preferable to perform irradiation while cooling with ice or the like. Note that ionizing radiation includes α rays and β rays.
rays, gamma rays, X-rays, or accelerated electron beams, but especially high-energy radiation, such as cobalt
Gamma rays and electron beams from 60° C. are suitable. The amount of ionizing radiation irradiated may be determined as appropriate, but generally it is sufficient to graft copolymerize the water-soluble polymer to the solid material and maintain the shape of a crosslinked gel. Typically, the irradiation range is preferably between 2 and 60 megarads, depending on the type of solid material to be irradiated. In the method of the present invention, the solid material is pretreated as described above, and then immersed in a solution in which the water-soluble polymer described above is dissolved. Here, the solvent for the solution is
It is preferable that the above-mentioned water-soluble polymer can be dissolved and that it can be easily removed by washing with water from the graft copolymer obtained by graft copolymerizing the water-soluble polymer onto a solid material. Usually, water may be used, but in some cases, an aqueous solution of an organic solvent and an inorganic salt that dissolves the water-soluble polymer, a mixed solvent thereof, or a mixed solvent of these and water may also be used. In addition, the concentration of the water-soluble polymer in this solution is preferably within a range that does not decompose when irradiated with ionizing radiation, and is usually 1% or more.
Preferably it should be between 5 and 20%. Note that as this water-soluble polymer, polyvinyl alcohol is used as described above. This polyvinyl alcohol may be of any type as long as it does not inhibit the graft copolymerization reaction, and may be either a completely saponified product or a partially saponified product, but in general, one with a high degree of saponification is preferred. Furthermore, there are no particular restrictions on the molecular weight or degree of polymerization of polyvinyl alcohol; however, the higher the molecular weight, the more dense the film can be formed, and it is preferable that the degree of polymerization be 50 or more in terms of the reaction efficiency of graft copolymerization. is preferred. Subsequently, in the method of the present invention, the solid material is irradiated with ionizing radiation while immersed in a solution containing a water-soluble polymer. The ionizing radiation used in this case may be the same as that described above. Although the irradiation dose varies depending on various conditions, 2 to 40 megarads is usually sufficient. According to the method of the present invention, since the solid material is irradiated with ionizing radiation in advance as a pretreatment, when graft copolymerizing the solid material with a water-soluble polymer in a solution, the copolymerization reaction The reaction proceeds quickly and accurately to the desired portion, and the desired graft copolymer can be efficiently produced. Note that if the graft copolymer produced according to the method of the present invention is taken out of the solution and washed with water, the unreacted water-soluble polymer and solvent adhering to the surface and inside of the graft copolymer will be completely removed. When washed off and then dried at room temperature, a graft copolymer with excellent physical properties and no impurities is obtained. As described above, the method of the present invention does not require a complicated removal process of unreacted monomers and has extremely high production efficiency. At the same time, the resulting graft copolymer has unprecedented high friction properties and durability. Because it has high frictional properties and does not contain toxic substances such as unreacted monomers, it is effectively used in various medical materials that require a high degree of durability, such as materials for artificial organs and surgical materials. In addition, this graft copolymer has excellent water-based lubrication properties, so it can be used as mechanical sliding members such as bearings that require a high degree of durability. A mixture of water and glycol may be used, and unlike conventional methods, there is no need for expensive lubricating oil, which is dangerous due to flammability, and is extremely safe and highly workable. Therefore, the method for producing a graft copolymer of the present invention can be effectively and widely used in the fields of various medical organs, mechanical sliding members, and their production. Next, examples of the present invention will be shown. Examples 1 to 7 Melt index 0.3g/10 minutes, density 0.965
21μm thick using g/ cm3 high density polyethylene
A film (Sample 1) was molded, a 53 mm diameter disc with a 12.5 mm diameter circular cutout in the center was cut out from this film, and this disc was
It was placed in a carbon dioxide atmosphere in the container shown in the figure, and then irradiated with gamma rays at a dose of 2.64 megarads using a cobalt-60 radiation source while cooling with dry ice (pre-irradiation). After the γ-ray irradiation as the pretreatment described above, the disk was removed from the container, and then immersed in an aqueous solution of polyvinyl alcohol with an average degree of polymerization of 490 as shown in Figure 2, using a cobalt-60 radiation source. γ-rays were irradiated at the doses shown in Table 1 (post-irradiation). After irradiation, sample 1 was washed with distilled water, and this sample 1
was further washed with methanol and dried at room temperature to determine the intrinsic viscosity [η] (dl/g), degree of polymerization, and grafting rate (%) of the grafted film of polyvinyl alcohol (PVA) on high-density polyethylene (HDPE). , and the film thickness (μm) was measured. The results are shown in Table 1. In addition,
The intrinsic viscosity [η] (dl/g) was measured by measuring the solution viscosity at 30° C. in a constant temperature bath using an Ubbelohde viscometer. The degree of polymerization P is determined by the relational formula of Nakajima et al. (Akio Nakajima, Polymer Chemistry, 6 , 460 (1949) [η] Water 30 °C =
Calculated using 7.50×10 -4 ×P 0.64 . The grafting rate was determined according to the following formula. Grafting rate (%) = Weight of HDPE board grafted with PVA - Weight of HDPE board / Weight of HDPE board x 100 On the other hand, the graft film thickness is PVA concentration C (g/100
cm 3 ), the amount of PVA grafting G (g/cm 3 ), and the specific gravity of the aqueous solution as 1. Graft film thickness (μm)=G/C×10 6 Here, the PVA graft amount G was defined as follows. G (g/cm 2 ) = Weight of HDPE board grafted with PVA -
Weight of HDPE plate/Area of both sides of HDPE plate Comparison Examples 1 and 2 The same sample as in Example 1 was used and evaluated under the same conditions, except that pre-irradiation was not performed. The results are shown in Table 1. Example 8 and Comparative Example 3 A 5 mm thick sheet (sample 2) was molded using the same HDPE as in Examples 1 to 7, and this was used in Examples 1 to 7.
γ-ray irradiation was performed as a pretreatment in the same manner as above. Thereafter, this sample 2 was immersed in a PVA aqueous solution (concentration 15 wt%) in the same manner as in Examples 1 to 7, and irradiated with gamma rays at a dose of 2.64 megarads using a cobalt-60 radiation source. After irradiation, the sample 2 was thoroughly washed with distilled water, and then the sample 2 was placed in a ball shown in Figure 3 in distilled water.
-On-Disk type friction measuring device was used to measure the friction coefficient. Ball is 3/16 inch steel ball
(SUJ-2) at a sliding speed of 18.8 cm/sec and loads of 0.5, 0.7, and 1.0 kgf. Figure 4 shows the temporal change in the obtained friction coefficient. Furthermore, as Comparative Example 3, an HDPE plate to which no PVA was grafted was used, and the coefficient of friction was measured in distilled water as described above. The results are shown in Figure 5. 【table】
第１図は前処理としての電離性放射線照射（前
照射）を行なう様子を示す説明図、第２図は溶液
に浸漬しながら電離性放射線照射（後照射）を行
なう様子を示す説明図、第３図は摩擦係数を測定
する器具の説明図、第４図は実施例８で得られた
グラフト共重合物の摩擦係数の経時変化を示すグ
ラフ、第５図はHDPE板の摩擦係数の経時変化を
示すグラフである。
１…試料、２…ガラス容器、３…ガラス栓、４
…PVA水溶液、５…金属線（吊り下げ用）、６…
鋼球、７…トルクアーム、８…荷重、９…プーリ
ー、１０…水。
Figure 1 is an explanatory diagram showing how ionizing radiation irradiation (pre-irradiation) is performed as a pretreatment, Figure 2 is an explanatory diagram showing how ionizing radiation irradiation (post-irradiation) is performed while immersed in a solution, Figure 3 is an explanatory diagram of a device for measuring the coefficient of friction, Figure 4 is a graph showing the change over time in the coefficient of friction of the graft copolymer obtained in Example 8, and Figure 5 is the change over time in the coefficient of friction of the HDPE plate. This is a graph showing. 1...Sample, 2...Glass container, 3...Glass stopper, 4
...PVA aqueous solution, 5...Metal wire (for hanging), 6...
Steel ball, 7...torque arm, 8...load, 9...pulley, 10...water.
Claims (1)
よりなる固体材料の表面の少なくとも一部に、前
処理としての電離性放射線照射を行ない、次いで
該固体材料をポリビニルアルコールを溶解した溶
液中に浸漬し、さらに浸漬したまま電離性放射線
照射を行なつて前記ポリビニルアルコールを前記
固体材料の表面にグラフト共重合させることを特
徴とする潤滑特性のすぐれたグラフト共重合物の
製造方法。 ２ 前処理としての電離性放射線照射を、固体材
料を照射した際に生成するラジカルを安定的に維
持できる雰囲気下にて行なう特許請求の範囲第１
項記載の方法。 ３ 架橋重合可能でかつ非水溶性の熱可塑性樹脂
が、ポリスチレン、ポリオレフイン、ポリアミ
ド、ポリ塩化ビニル、合成ゴム、ポリ酢酸ビニ
ル、ポリエステル、ポリアクリレート、ポリメタ
アクリレートおよびこれらの混合物よりなる群か
ら選ばれた熱可塑性樹脂である特許請求の範囲第
１項記載の方法。[Claims] 1. At least a portion of the surface of a solid material made of a water-insoluble thermoplastic resin capable of crosslinking polymerization is irradiated with ionizing radiation as a pretreatment, and then the solid material is treated with polyvinyl alcohol. Production of a graft copolymer with excellent lubricating properties, characterized in that the polyvinyl alcohol is graft copolymerized on the surface of the solid material by immersing it in a dissolved solution and irradiating it with ionizing radiation while immersed. Method. 2. Claim 1, in which the ionizing radiation irradiation as a pretreatment is carried out in an atmosphere that can stably maintain the radicals generated when the solid material is irradiated.
The method described in section. 3. The crosslinking polymerizable and water-insoluble thermoplastic resin is selected from the group consisting of polystyrene, polyolefin, polyamide, polyvinyl chloride, synthetic rubber, polyvinyl acetate, polyester, polyacrylate, polymethacrylate, and mixtures thereof. The method according to claim 1, wherein the thermoplastic resin is a thermoplastic resin.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13770981A JPS5840323A (en) | 1981-09-03 | 1981-09-03 | Graft copolymer having excellent lubricity and its production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13770981A JPS5840323A (en) | 1981-09-03 | 1981-09-03 | Graft copolymer having excellent lubricity and its production |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5840323A JPS5840323A (en) | 1983-03-09 |
| JPH0142297B2 true JPH0142297B2 (en) | 1989-09-12 |
Family
ID=15204983
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13770981A Granted JPS5840323A (en) | 1981-09-03 | 1981-09-03 | Graft copolymer having excellent lubricity and its production |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5840323A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0678561B2 (en) * | 1986-03-20 | 1994-10-05 | 株式会社トーキン | Method for manufacturing substrate for sputtering target |
| JP4655938B2 (en) | 2004-01-21 | 2011-03-23 | 東レ株式会社 | Fractionation apparatus and fractionation method |
| JP4910700B2 (en) | 2004-08-30 | 2012-04-04 | 東レ株式会社 | Fractionation device |
| US20100092685A1 (en) | 2007-02-20 | 2010-04-15 | Toray Industries, Inc. | Method for producing resin molding |
| JP5130790B2 (en) * | 2007-06-07 | 2013-01-30 | Ｊｎｃ株式会社 | Surface-modified polymer article and method for producing the same |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5474872A (en) * | 1977-11-26 | 1979-06-15 | Kansai Paint Co Ltd | Surface modification of polymer |
-
1981
- 1981-09-03 JP JP13770981A patent/JPS5840323A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5474872A (en) * | 1977-11-26 | 1979-06-15 | Kansai Paint Co Ltd | Surface modification of polymer |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5840323A (en) | 1983-03-09 |
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