JPH0259961B2 - - Google Patents
Info
- Publication number
- JPH0259961B2 JPH0259961B2 JP58120627A JP12062783A JPH0259961B2 JP H0259961 B2 JPH0259961 B2 JP H0259961B2 JP 58120627 A JP58120627 A JP 58120627A JP 12062783 A JP12062783 A JP 12062783A JP H0259961 B2 JPH0259961 B2 JP H0259961B2
- Authority
- JP
- Japan
- Prior art keywords
- monomer
- base material
- refractive index
- prepolymer
- synthetic resin
- 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 - Lifetime
Links
- 239000000178 monomer Substances 0.000 claims description 98
- 239000000463 material Substances 0.000 claims description 64
- 238000010438 heat treatment Methods 0.000 claims description 36
- 238000000034 method Methods 0.000 claims description 28
- 230000005540 biological transmission Effects 0.000 claims description 21
- 230000003287 optical effect Effects 0.000 claims description 19
- 238000009826 distribution Methods 0.000 claims description 18
- 238000004519 manufacturing process Methods 0.000 claims description 17
- 229920000642 polymer Polymers 0.000 claims description 13
- 229920003002 synthetic resin Polymers 0.000 claims description 13
- 239000000057 synthetic resin Substances 0.000 claims description 13
- 229920001187 thermosetting polymer Polymers 0.000 claims description 7
- 239000004033 plastic Substances 0.000 claims description 6
- 229920003023 plastic Polymers 0.000 claims description 6
- 230000000379 polymerizing effect Effects 0.000 claims description 3
- 230000002250 progressing effect Effects 0.000 claims 1
- 238000009792 diffusion process Methods 0.000 description 46
- 238000006116 polymerization reaction Methods 0.000 description 25
- 239000000203 mixture Substances 0.000 description 19
- 239000012530 fluid Substances 0.000 description 16
- IJGRMHOSHXDMSA-UHFFFAOYSA-N nitrogen Substances N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 16
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 14
- 239000007789 gas Substances 0.000 description 13
- 239000012071 phase Substances 0.000 description 13
- 239000004809 Teflon Substances 0.000 description 11
- 229920006362 Teflon® Polymers 0.000 description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 11
- SYFOAKAXGNMQAX-UHFFFAOYSA-N bis(prop-2-enyl) carbonate;2-(2-hydroxyethoxy)ethanol Chemical compound OCCOCCO.C=CCOC(=O)OCC=C SYFOAKAXGNMQAX-UHFFFAOYSA-N 0.000 description 10
- 150000001875 compounds Chemical class 0.000 description 10
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 9
- 230000008569 process Effects 0.000 description 9
- 239000003112 inhibitor Substances 0.000 description 7
- 239000007788 liquid Substances 0.000 description 7
- 239000007791 liquid phase Substances 0.000 description 7
- 229910001873 dinitrogen Inorganic materials 0.000 description 6
- 229910052757 nitrogen Inorganic materials 0.000 description 6
- 230000002093 peripheral effect Effects 0.000 description 6
- ROLAGNYPWIVYTG-UHFFFAOYSA-N 1,2-bis(4-methoxyphenyl)ethanamine;hydrochloride Chemical compound Cl.C1=CC(OC)=CC=C1CC(N)C1=CC=C(OC)C=C1 ROLAGNYPWIVYTG-UHFFFAOYSA-N 0.000 description 5
- 239000004641 Diallyl-phthalate Substances 0.000 description 5
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 5
- QUDWYFHPNIMBFC-UHFFFAOYSA-N bis(prop-2-enyl) benzene-1,2-dicarboxylate Chemical compound C=CCOC(=O)C1=CC=CC=C1C(=O)OCC=C QUDWYFHPNIMBFC-UHFFFAOYSA-N 0.000 description 5
- 229920001577 copolymer Polymers 0.000 description 5
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 5
- QIGBRXMKCJKVMJ-UHFFFAOYSA-N Hydroquinone Chemical compound OC1=CC=C(O)C=C1 QIGBRXMKCJKVMJ-UHFFFAOYSA-N 0.000 description 4
- BAPJBEWLBFYGME-UHFFFAOYSA-N Methyl acrylate Chemical compound COC(=O)C=C BAPJBEWLBFYGME-UHFFFAOYSA-N 0.000 description 4
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 4
- -1 allyl ester Chemical class 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 125000005395 methacrylic acid group Chemical group 0.000 description 4
- 239000012808 vapor phase Substances 0.000 description 4
- 239000004342 Benzoyl peroxide Substances 0.000 description 3
- OMPJBNCRMGITSC-UHFFFAOYSA-N Benzoylperoxide Chemical compound C=1C=CC=CC=1C(=O)OOC(=O)C1=CC=CC=C1 OMPJBNCRMGITSC-UHFFFAOYSA-N 0.000 description 3
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 3
- 238000013459 approach Methods 0.000 description 3
- 235000019400 benzoyl peroxide Nutrition 0.000 description 3
- 239000000499 gel Substances 0.000 description 3
- 229910001220 stainless steel Inorganic materials 0.000 description 3
- 239000010935 stainless steel Substances 0.000 description 3
- KOZCZZVUFDCZGG-UHFFFAOYSA-N vinyl benzoate Chemical compound C=COC(=O)C1=CC=CC=C1 KOZCZZVUFDCZGG-UHFFFAOYSA-N 0.000 description 3
- 229920001567 vinyl ester resin Polymers 0.000 description 3
- 125000003903 2-propenyl group Chemical group [H]C([*])([H])C([H])=C([H])[H] 0.000 description 2
- SOGAXMICEFXMKE-UHFFFAOYSA-N Butylmethacrylate Chemical compound CCCCOC(=O)C(C)=C SOGAXMICEFXMKE-UHFFFAOYSA-N 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- 230000004075 alteration Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000007598 dipping method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 150000002148 esters Chemical class 0.000 description 2
- 238000001879 gelation Methods 0.000 description 2
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 2
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 2
- 239000003505 polymerization initiator Substances 0.000 description 2
- QTKPMCIBUROOGY-UHFFFAOYSA-N 2,2,2-trifluoroethyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OCC(F)(F)F QTKPMCIBUROOGY-UHFFFAOYSA-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
- LTHJXDSHSVNJKG-UHFFFAOYSA-N 2-[2-[2-[2-(2-methylprop-2-enoyloxy)ethoxy]ethoxy]ethoxy]ethyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OCCOCCOCCOCCOC(=O)C(C)=C LTHJXDSHSVNJKG-UHFFFAOYSA-N 0.000 description 1
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 1
- 229910001369 Brass Inorganic materials 0.000 description 1
- JIGUQPWFLRLWPJ-UHFFFAOYSA-N Ethyl acrylate Chemical compound CCOC(=O)C=C JIGUQPWFLRLWPJ-UHFFFAOYSA-N 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 1
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000001252 acrylic acid derivatives Chemical class 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- PIPBVABVQJZSAB-UHFFFAOYSA-N bis(ethenyl) benzene-1,2-dicarboxylate Chemical compound C=COC(=O)C1=CC=CC=C1C(=O)OC=C PIPBVABVQJZSAB-UHFFFAOYSA-N 0.000 description 1
- FWICIOVOJVNAIJ-UHFFFAOYSA-N bis(ethenyl) benzene-1,3-dicarboxylate Chemical compound C=COC(=O)C1=CC=CC(C(=O)OC=C)=C1 FWICIOVOJVNAIJ-UHFFFAOYSA-N 0.000 description 1
- ZDNFTNPFYCKVTB-UHFFFAOYSA-N bis(prop-2-enyl) benzene-1,4-dicarboxylate Chemical compound C=CCOC(=O)C1=CC=C(C(=O)OCC=C)C=C1 ZDNFTNPFYCKVTB-UHFFFAOYSA-N 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 125000004185 ester group Chemical group 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- PYGSKMBEVAICCR-UHFFFAOYSA-N hexa-1,5-diene Chemical group C=CCCC=C PYGSKMBEVAICCR-UHFFFAOYSA-N 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000005764 inhibitory process Effects 0.000 description 1
- 125000000959 isobutyl group Chemical group [H]C([H])([H])C([H])(C([H])([H])[H])C([H])([H])* 0.000 description 1
- 125000001449 isopropyl group Chemical group [H]C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 150000002734 metacrylic acid derivatives Chemical class 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- PNJWIWWMYCMZRO-UHFFFAOYSA-N pent‐4‐en‐2‐one Natural products CC(=O)CC=C PNJWIWWMYCMZRO-UHFFFAOYSA-N 0.000 description 1
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 1
- 229920002959 polymer blend Polymers 0.000 description 1
- FBCQUCJYYPMKRO-UHFFFAOYSA-N prop-2-enyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OCC=C FBCQUCJYYPMKRO-UHFFFAOYSA-N 0.000 description 1
- QTECDUFMBMSHKR-UHFFFAOYSA-N prop-2-enyl prop-2-enoate Chemical compound C=CCOC(=O)C=C QTECDUFMBMSHKR-UHFFFAOYSA-N 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 125000002914 sec-butyl group Chemical group [H]C([H])([H])C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 1
- 229920001909 styrene-acrylic polymer Polymers 0.000 description 1
- SJMYWORNLPSJQO-UHFFFAOYSA-N tert-butyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OC(C)(C)C SJMYWORNLPSJQO-UHFFFAOYSA-N 0.000 description 1
- 125000000999 tert-butyl group Chemical group [H]C([H])([H])C(*)(C([H])([H])[H])C([H])([H])[H] 0.000 description 1
- 238000012719 thermal polymerization Methods 0.000 description 1
- 125000003944 tolyl group Chemical group 0.000 description 1
- GRPURDFRFHUDSP-UHFFFAOYSA-N tris(prop-2-enyl) benzene-1,2,4-tricarboxylate Chemical compound C=CCOC(=O)C1=CC=C(C(=O)OCC=C)C(C(=O)OCC=C)=C1 GRPURDFRFHUDSP-UHFFFAOYSA-N 0.000 description 1
- XHGIFBQQEGRTPB-UHFFFAOYSA-N tris(prop-2-enyl) phosphate Chemical compound C=CCOP(=O)(OCC=C)OCC=C XHGIFBQQEGRTPB-UHFFFAOYSA-N 0.000 description 1
- KJWHEZXBZQXVSA-UHFFFAOYSA-N tris(prop-2-enyl) phosphite Chemical compound C=CCOP(OCC=C)OCC=C KJWHEZXBZQXVSA-UHFFFAOYSA-N 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/44—Mechanical structures for providing tensile strength and external protection for fibres, e.g. optical transmission cables
- G02B6/4479—Manufacturing methods of optical cables
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
- B29C48/06—Rod-shaped
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
- B29K2105/0002—Condition, form or state of moulded material or of the material to be shaped monomers or prepolymers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2995/00—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
- B29K2995/0018—Properties of moulding materials, reinforcements, fillers, preformed parts or moulds having particular optical properties, e.g. fluorescent or phosphorescent
- B29K2995/0031—Refractive
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Optical Fibers, Optical Fiber Cores, And Optical Fiber Bundles (AREA)
- Polymerisation Methods In General (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Description
この発明は、屈折率分布を有する合成樹脂光伝
送体の製造方法に関し、さらに詳細には、合成樹
脂光伝送体の連続的製造を可能にする技術に関す
る。
光伝送体として、中心軸からの距離の二乗に比
例して減少する屈折率の分布を有する透明棒状体
が知られている。この透明棒状体は凸レンズ作用
を有し、またその屈折率分布は(1)式で近似され
る。
ｎ（ｒ）＝n0（１−１／２Ar2） …(1)
（式中、ｎ（ｒ）は中心軸からの距離ｒの点に
おける屈折率、n0は中心軸における屈折率、Ａは
正の定数をそれぞれ表わす。）
このような透明棒状体中を光束は蛇行して伝播
し、その周期Ｌは(2)式で表わされる。
Ｌ＝2π／√ …(2)
また、(3)式で近似されるように、中心軸からの
距離の２乗に比例して増大する屈折率分布を有す
る場合には、透明棒状体は凹レンズ作用を有する
光伝送体となる。
ｎ（ｒ）＝n0（１＋１／２Br2） …(3)
（式中、ｎ（ｒ）およびn0は前記に同じであり、
Ｂは正の定数である。）
このような屈折率分布を有する合成樹脂光伝送
体の製造方法は、特公昭52−5857号公報、特開昭
51−16394号、特開昭54−119939号公報などに記
載されている。特公昭52−5857号公報および特開
昭51−16394号公報に記載された方法では、まず、
網状重合体Paを生成する架橋性単量体Maを液体
状態から流動性を失つたゲル状態になるまで初期
重合させて透明なゲル状母材を形成する。次い
で、この母材を単量体Maとは異なる単量体Mb
からなる液相中に浸漬して、母材がその表面から
内部に向かつて次第に減少するような単量体Mb
の濃度勾配を持つように、単量体Mbを拡散させ
る。このとき、単量体Mbとしては、網状重合体
Paの屈折率とは異なる屈折率を有する重合体Pb
を生成する単量体を用いる。単量体Mbは拡散と
同時におよび／または拡散後の熱処理工程中に重
合し、またこの時、単量体Maの重合も完結す
る。このようにして、特公昭52−5857号公報及び
特開昭51−16394号公報に記載された方法では、
所望の屈折率分布を有する合成樹脂光伝送体を得
るようにしている。
ところが、上述した方法では、母材を液状の単
量体Mb中に浸漬させて母材表面と液状の単量体
Mbとを直接接触させるために、いくつか不利な
点があつた。例えば、単量体Mbの拡散と重合と
を同時に行うような場合には、浸漬温度を比較的
高温にするため、および母材中に通常含有されて
いる重合開始剤が浸漬時間の経過と共に液相に溶
出するため、液相中でも単量体Mbの重合が徐々
に起つて粘稠になる。その結果、拡散を終えて母
材を液相中から取り出す際に、このようにして形
成された粘稠層が母材表面に付着したまま取り出
されてしまう。そして重合を完結させるために行
う熱処理工程中に、この粘稠層から単量体Mbが
浸出して母材内に拡散し、得られる光伝送体の外
周部付近における屈折率の好ましくない歪みを増
大させる原因となる。しかしながら、一方、液相
での単量体Mbの重合を抑制するために重合禁止
剤を加えておくと、これが単量体Mbの拡散と同
時に母材中に拡散して熱処理工程における重合完
結を阻害する。
また、単量体Mbを拡散後に重合させるような
場合は比較的低い浸漬温度ですむが、この場合に
は拡散した単量体Mbが熱処理工程中に母材の外
周部から蒸発するため、やはり外周部付近の屈折
率分布に好ましくない歪みを増大させる原因とな
る。
特開昭54−119939号公報に記載された方法は上
述の方法を改良して外周部付近での屈折率分布の
歪みを回避しようとするものである。この方法に
よれば、単量体Mbの拡散を気相中で行つてい
る。すなわち、単量体Mbの蒸気雰囲気中に母材
を所定時間配置して単量体Mbを母材内に拡散さ
せこの拡散と同時に単量体Mbを一部重合させ、
最後に熱処理によつて重合を完結させるようにし
ている。この方法では、母材は液相の単量体Mb
とでなく、気相の単量体Mbと接触するので次の
ような利点がある。
(1) 母材の表面に余分の単量体Mbが付着しな
い。故に、熱処理工程中に付着した単量体Mb
が母材の表面から内部へ拡散することがない。
また、拡散を高温で行うから単量体Mbは母材
内部に拡散しつつ重合して固定化する。そこ
で、熱処理工程中に単量体Mbが母材の外周部
から蒸発することもない。したがつて、外周部
での屈折率の歪みが少くかつ所期の屈折率分布
を広い範囲で有する光伝送体が得られる。
(2) 単量体Mbの蒸気の供給源である液体の単量
体Mb中に重合禁止剤を添加することによつ
て、液相での単量体Mbの重合を防止できる。
その際、蒸気圧の低い重合禁止剤を用いれば、
これはほとんど気化しないので、母材内に拡散
することもなく、したがつて熱処理工程に重合
が阻害されない。さらに、単量体Mbの供給速
度を調節すれば重合禁止剤を加える必要もなく
なり、単量体Mbを何回も繰り返して使用する
ことが可能となつてその回収率が高められる。
しかしながら、この方法には次のような欠点が
ある。すなわち、母材を形成する工程、単量体
Mbを拡散させる工程、熱処理工程の何れもバツ
チ法で行われるため、形成される母材に組成のば
らつきがあつたり、拡散装置内の温度、単量体
Mbの蒸気濃度、熱処理装置内の温度が場所によ
つてわずかにでも異なつたりすると、得られる光
伝送体の特性が不均一になつて品質の一定な光伝
送体の製造は困難となる。このような不利益は、
上述した特公昭52−5857号公報および特開昭49−
8857号公報に記載された方法においても同様であ
り、また、バツチ法による従来例ではいずれの場
合にも免れないものであつた。
この発明は、このような点に鑑みて鋭意研究の
末に完成されたものであつて、母材を形成させる
工程、単量体Mbを拡散させる工程および熱処理
工程のすべてを連続化することを可能にし、例え
ば直径１〜20mmの品質の一定な光伝送体を効率的
に製造しようとするものである。
すなわち、この発明は母材を形成する際に、単
量体Maを予備重合させて塑性流動を表わす一般
式：
Ｄ＝Kσn
（式中、Ｄはずり速度、σはずり応力、Ｋは塑
性粘度の逆数、ｎは定数をそれぞれ表わす。）
における20℃でのｎの値が1.10以上である塑性流
動を示すプレポリマーを得、次いでこのプレポリ
マーを細長い通路に供給して、この通路を進行さ
せつつ加熱重合させると共に成形することによつ
て前記母材を得ることを特徴とする合成樹脂光伝
送体の製造方法に係るものである。
次に、この発明による合成樹脂光伝送体の製造
方法の実施例を図面に示した装置を用いた場合に
ついて説明する。
まず、屈折率Naの網状重合体Paを生成する単
量体Maを予備重合させて、ゲル化直前で流動性
を保持している粘性流体（プレポリマー）を生成
させる。このプレポリマーを第１図に示す装置の
押出し器１に入れ、冷却水によつて一旦冷却しな
がら、連続的に押出す。
この発明では、プレポリマーが、一般式：
Ｄ＝Kσn …(4)
（式中、Ｄはずり速度、σはずり応力、Ｋは塑
性粘度の逆数、ｎは定数をそれぞれ表わす。）
で表わされる非ニユートン流体の一般方程式
（Ostwaldのべき法則）における20℃でのｎの値
が1.10以上である塑性流動を示すことが重要であ
る。
単量体または低粘度プレポリマーのようなニユ
ートン流体に近い流体を細長い管内に導入し、そ
の管内を通過させながら加熱して重合させる場
合、熱は管の外側から加えられるために、管近傍
の周辺領域から重合が進み、それに伴つて粘度が
上昇して行く、管内を流れる流体には、中心が最
大で周辺に向かうに従つて放物線状に流速が減少
するという速度分布が元々存在しているが、重合
が進むにつれて、この周辺領域と中心領域との間
の速度差はさらに大きくなる。そして、最終的に
は周辺領域の流体が先にゲル化して管内に滞留
し、中心領域の流体はほとんど重合せずに管から
流れ出ることになる。
これを是正するためには、管内での流体の速度
分布をなるべく一定にする必要がある。すなわ
ち、管内の流体をビンガム流体に近づければよ
い。ビンガム流体は上記式(4)においてはｎ＝∞の
場合であつて、管内の流体の流速は一定となる。
ｎが小さくなつて１に近づくほど、流体はニユー
トン流体に近づく。また、管の内壁に近い周辺付
近での流体の流速はｎの値によつてはそれほど変
化せず、むしろｎが大きいほど流速も大きいが、
ｎが１に近づくほど中心付近での流速が大きくな
り、その結果周辺領域と中心領域との流速の差が
大きくなつて速度分布の放物線がシヤープにな
る。
このような観点から、この発明では上述したよ
うに単量体Maを予備重合させて、ｎの値が1.10
以上である粘性流体としてから管内に送り込むも
のである。すなわち、ｎの値が1.10未満では、は
じめに周辺付近がゲル化されてしまうと、中心付
近の単量体Maは重合されずに管内から流出し、
良好な母材が形成できない。この場合、流速を極
端に落とせば母材ができないこともないが、生産
性が悪くなつて実用的でない。また、好ましくは
ｎの値は大きくとも1.50である。これはｎの値が
大きすぎると管内への押し込みが困難になつたり
母材が不均質となつて不都合が生ずるからであ
る。
なお、上記(4)式におけるＫの値およびｎの値は
それぞれ粘度計（例えば回転式粘度計）を用いて
求めることができる。すなわち粘度計の回転数
（これでＤが決まる）を変えて、それぞれのσを
測定した後、これらをグラフにプロツトしてＫお
よびｎの値を求める。
このような条件を満たすプレポリマー１０は、
押出された後、引き続き黄銅製ブロツク等の加熱
ジヤケツト２を貫通するテフロンチユーブ３中に
連続的に導入される。このテフロンチユーブ３は
円形断面を有する直径１〜20mmのものであつてよ
い。ここで、予めテフロンチユーブ３内に上方か
らステンレス管の下端部を挿入しておくと、プレ
ポリマー１０の先端がこのステンレス管の下端部
に接触した状態でゲル化するので、ステンレス管
の下端部とプレポリマー１０の先端とが一体結合
される。この後押出し速度と同じ速度でステンレ
ス管を引き上げ装置で引き上げると、それに伴わ
れたプレポリマーは全製造工程を経過する間に光
伝送体となつて連続的にかつ装置内に滞ることな
く生成されて出てくる。加熱ジヤケツト２には、
その上部に比較的高温の水１６、下部にそれより
低温の水１７がそれぞれ供給されていて、下部か
ら上部に向つて次第に温度が上昇するような温度
勾配でもつて、テフロンチユーブ３を加熱してい
る。そこで、テフロンチユーブ３を通過するうち
にプレポリマー１０は加熱重合してゲル化し、こ
のゲル化したプレポリマーは母材１１となる。こ
の加熱重合の際の加熱速度は0.1〜10℃／分であ
るのが好ましい。上述したような温度勾配のもと
で加熱される場合には、プレポリマー１０の重合
およびそれに伴う粘度上昇が共に徐々に進行する
から、ビンガム流体に近い流動状態に保持したま
ま、プレポリマー１０を流動させることが可能と
なる。その結果、半径方向に均一な組成を持つた
母材１１を連続的に形成することが可能となる。
なお、ここでテフロンチユーブ３は、プレポリマ
ー１０や母材１１との摩擦が小さいために特に有
用であるが、他の樹脂や金属製のチユーブであつ
てさしつかえない。
このようにして、加熱ジヤケツト２内のテフロ
ンチユーブ３からは、ほとんど流動性を失つて自
己保形性を有するゲル状の母材１１が生成されて
来る。この母材１１は、アセトンに不溶な成分、
すなわち網状重合体の部分を好ましくは５〜90重
量％、さらに好ましくは10〜50重量％含んでい
る。この成分が少なすぎると流動性が大きくな
り、また多すぎると後の拡散工程で単量体Mbの
拡散速度が遅くなりすぎるので好ましくない。
続いて、母材１１は気相拡散装置４に送り送ま
れる。この装置の内部にある拡散室４ｂは蒸気発
生器１４から導入口１９を介して供給される単量
体Mbの蒸気を含む雰囲気によつて満たされてい
る。単量体Mbの蒸気は真空ポンプ１５によつて
排出口２０から回収される。上記雰囲気中に母材
１１を一定時間滞留させる間に、気相中の単量体
Mbは母材１１の周表面に到達し、周表面から母
材１１の半径方向へ拡散移動する。その結果、母
材１１内には単量体Mbの濃度がその中心軸から
周表面に向かつて二乗近似で次第に増大するよう
な濃度勾配ができる。また、拡散装置４には、拡
散室４ｂを取り囲む外側管４ａが設けられてお
り、この外側管４ａには導入口２１から排出口２
２へと温水１８が流されている。この温水１８で
拡散室４ｂ内が加熱されることによつて、単量体
Mbの一部が拡散しつつ単独であるいは母材１１
内のプレポリマー等と重合し、上記濃度勾配が固
定化されていく。
単量体Mbの蒸気を含む雰囲気は、酸素による
重合の阻害を回避するために、空気を排気するか
窒素置換してから形成される。またその温度は、
公知の方法の場合と同様に、単量体Mbが比較的
高い蒸気圧を有しかつ母材内に拡散できる値に保
たれる必要があるため、例えば５〜90℃に設定さ
れる。この温度が高くなればなるほど、単量体
Mbの拡散速度は大きくなるが、母材自体の重合
速度も増大してしまうので好ましくない。また、
母材を単量体Mbの蒸気を含む雰囲気中に滞留さ
せておく時間（拡散時間）および上記拡散温度
は、得ようとする光伝送体の屈折率勾配すなわち
単量体Mbの上記濃度勾配によつて決められる。
しかし、この拡散時間が極度に長かつたり拡散温
度が高すぎたりすると、単量体Mbの濃度勾配が
平坦化したりあるいは、母材の外周部付近で濃度
勾配が急に大きくなる恐れがあり、所望の屈折率
勾配が得られない。
単量体Mbを拡散させた後、母材１１は拡散装
置から熱処理管５に導かれる。この熱処理管５は
ヒータ１３によつて加熱されているが、このヒー
タ１３の温度を装置の下部から上部へと段階的に
高温にしていくことによつて、温度勾配を形成さ
せるようにしてもよい。またこの熱処理管５の内
部も窒素置換されている。ここで、母材１１はさ
らに加熱されて重合が完結される。こうして得ら
れる光伝送体の屈折率は、後述するように単量体
Maと単量体Mbとの組合せによつて、中心軸か
らの距離の二乗にほヾ比例して半径方向に連続的
に増大あるいは減少する屈折率勾配を有してい
る。この屈折率は光伝送体の長さ方向には変化せ
ず一定である。
以上に述べた実施例では、気相拡散法を採り入
れているが、液相拡散法によつて行うことも可能
である。また気相拡散の場合、単量体Mbの蒸気
を含む雰囲気を形成しこれを保持するために、少
くとも拡散装置内を一定の減圧下に保持するよう
にしてもよい。しかし単量体Mbの沸点が比較的
低い場合には常圧で実施することも可能である。
常圧で行う気相拡散法の場合、第２図および第３
図に示す気相拡散装置４を用いて、次の(a)，(b)の
方法により実施可能である。
(a) 液状の単量体Mbを気相拡散装置４の上部の
導入口２４から供給し、いつたんモノマー溜め
６に貯める。そしてオーバーフローした液状の
単量体Mbがごく細いスリツト７を通つて流下
し、次いで内面８を伝つて流下するようにす
る。この内面８を、外側管４ａ中に通されてい
る温水１８によつて加熱し、流下する単量体
Mbを蒸発させる。また窒素ガスは導入口２５
から導入され、気化した単量体Mbと共に排出
口２０からポンプに回収される。気化せずに流
下した液状の単量体Mbは排出口２６を経て回
収される。
(b) 単量体Mbを拡散装置の下部のモノマー溜め
６に導入し、その単量体Mb中に細いノズル２
３等から窒素ガスを噴射させて窒素の気泡を発
生させることによつて、単量体Mbの気化を促
進させて、拡散室４ｂを単量体Mbの蒸気で満
たす。
上述した実施例では、母材を形成させる工程、
単量体Mbを拡散させる工程および熱処理工程を
すべて連続的に行つているが、全工程あるいはそ
のいくつかを別々に行うバツチ方式にもこの発明
の製造方法は適用可能である。
この発明の方法において、単量体Maとしては
重合して屈折率Naの透明な網状重合体Paを生成
することができる単量体が使用されるが、この単
量体は単一の単量体であつても複数種の単量体の
混合物であつてもよい。このような単量体Maと
しては、アリル基、アクリル酸基、メタクリル酸
基およびビニル基のような二重結合を含む基をそ
れぞれ２個以上有するか、これらのうちの２種類
以上を同時に有する単量体が好適である。次に単
量体Maの具体例を挙げる。
(1) アリル化合物およびその混合物。
フタル酸ジアリル、イソフタル酸ジアリル、テ
レフタル酸ジアリル、ジエチレングリコールビス
アリルカーボネート等のジアリルエステル；トリ
メリト酸トリアリル、リン酸トリアリル、亜リン
酸トリアリル等のトリアリルエステル；メタクリ
ル酸アリル、アクリル酸アリル等の不飽和酸アリ
ルエステル。
(2) R1−R2−R3で表わされる化合物およびその
混合物。
R1およびR3のいずれもビニル基、アクリル酸
基、ビニルエステル基、またはメタクリル酸基で
ある化合物；R1およびR3のいずれか一方がビニ
ル基、アクリル酸基、メタクリル酸基およびビニ
ルエステル基の４つの基のうちいずれかであり、
他方が残りの３つの基のうちのいずれかである化
合物。ここで、R2は以下に示される２価の基の
うちから選択できる。
(3) 上記(1)と(2)の単量体の混合物、またはモノビ
ニル化合物、ビニルエステル類、アクリル酸エ
ステル類およびメタクリル酸エステル類の５種
のうちの少なくとも１種と上記(1)または(2)の単
量体（またはその混合物）との混合物。
この発明において、単量体Mbとしてはそれが
重合した時に、上記屈折率Naよりも大きいかま
たは小さい屈折率Nbを有する透明な重合体Pbを
形成するものが選ばれる。単量体Mbは単一の単
量体であつても複数種の単量体の混合物であつて
もよい。重合体Pbは網状重合体および線形重合
体のいずれであつてもよい。屈折率Nbが屈折率
Naよりも小さい場合、得られる光伝送体は上記
(1)式で表わされるような屈折率分布が形成された
凸レンズ作用を有するものとなる。逆に、屈折率
Nbが屈折率Naよりも大きい場合には、上記(3)式
で表わされる屈折率分布で凹レンズ作用を有する
光伝送体が得られる。これらの屈折率の差｜Na
−Nb｜は0.005以上であるのが好ましく、この差
が小さすぎると所望の屈折率勾配が得られない。
また、単量体Mbは、特に気相拡散させる場合、
比較的高い蒸気圧を有するものであるのが好まし
く、例えば拡散温度において５mmHgよりも高い
飽和蒸気圧を有するのが好ましい。このような単
量体Mbの例としては、スチレン、メタクリル酸
エステル、アクリル酸エステル、酢酸ビニル、塩
化ビニル、アクリロニトリル、ブタジエンおよび
これらの混合物が挙げられる。
この発明の網状重合体Paと単量体Mbとの組合
せの好ましい例としては後述するような低色収差
の光伝送体の製造に適した例の他に次のような組
合せがある。まずNa＞Nbの場合、フタル酸ジア
リル重合体−メタクリル酸メチル、フタル酸ジア
リル重合体−アクリル酸メチルとメタクリル酸メ
チルとの混合物、イソフタル酸ジアリル重合体−
メタクリル酸メチル、フタル酸ジアリル重合体と
スチレンとの共重合体−メタクリル酸エステル、
イソフタル酸ジアリルとスチレンとの共重合体−
アクリル酸エステル、フタル酸ジビニルと安息香
酸ジビニルとの共重合体−メタクリル酸エステ
ル、イソフタル酸ジビニルと安息香酸ビニルとの
共重合体−メタクリル酸エステル、安息香酸ビニ
ルとイソフタル酸ジアリルとの共重合体−メタク
リル酸エステルなどである。また、Na＜Nbの場
合の例は、ジエチレングリコールビスアリルカー
ボネート重合体−スチレン、ジエチレングリコー
ルビスアリルカーボネート重合体−イソフタル酸
ジアリルなどである。
また特に、低色収差の合成樹脂光伝送体を製造
するに適した単量体Maと単量体Mbとの組合せ
としては、次のようなものが例示できる。
(a) Maとしてジエチレングリコールビスアリル
カーボネート、またはこれとフタル酸ジアリ
ル、イソフタル酸ジアリル、安息香酸ビニルも
しくはスチレンとの混合物（ただし、この混合
物中のジエチレングリコールビスアリルカーボ
ネートの量は50重量％以上であるのが好まし
く、より好ましくは70重量％以上である）。
Mbとして、化合物(A)：
〔式中、Ｘは水素原子またはメチル基、Ｙは
フエニル基、メチルフエニル基、ビニル基、ｉ
−プロピル基、ｉ−ブチル基、ｓ−ブチル基、
ｔ−ブチル基、
The present invention relates to a method of manufacturing a synthetic resin light transmitting body having a refractive index distribution, and more particularly to a technique that enables continuous production of a synthetic resin light transmitting body. A transparent rod-shaped body having a refractive index distribution that decreases in proportion to the square of the distance from the central axis is known as a light transmission body. This transparent rod-shaped body has a convex lens effect, and its refractive index distribution is approximated by equation (1). n(r)=n 0 (1-1/2Ar 2 )...(1) (where n(r) is the refractive index at the point of distance r from the central axis, n 0 is the refractive index at the central axis, A each represents a positive constant.) The light beam propagates in a meandering manner in such a transparent rod-shaped body, and its period L is expressed by equation (2). L=2π/√ …(2) Also, as approximated by equation (3), if the transparent rod-shaped body has a refractive index distribution that increases in proportion to the square of the distance from the central axis, it becomes a concave lens. It becomes a light transmission body that has a function. n(r)=n 0 (1+1/2Br 2 )...(3) (where n(r) and n 0 are the same as above,
B is a positive constant. ) A method of manufacturing a synthetic resin optical transmitter having such a refractive index distribution is described in Japanese Patent Publication No. 52-5857 and Japanese Patent Application Laid-Open No.
It is described in No. 51-16394, Japanese Unexamined Patent Publication No. 119939/1984, etc. In the method described in Japanese Patent Publication No. 52-5857 and Japanese Patent Application Laid-Open No. 51-16394, first,
The crosslinkable monomer Ma that produces the network polymer Pa is initially polymerized from a liquid state to a gel state that has lost fluidity to form a transparent gel-like matrix. Next, this base material is treated with a monomer Mb different from the monomer Ma.
The monomer Mb is immersed in a liquid phase consisting of a monomer Mb such that the matrix gradually decreases from the surface to the inside.
Monomeric Mb is diffused so that it has a concentration gradient of . At this time, the monomer Mb is a network polymer.
Polymer Pb with a refractive index different from that of Pa
A monomer that produces is used. The monomer Mb is polymerized simultaneously with the diffusion and/or during the heat treatment step after the diffusion, and at this time the polymerization of the monomer Ma is also completed. In this way, the methods described in Japanese Patent Publication No. 52-5857 and Japanese Patent Application Laid-Open No. 51-16394,
An attempt is made to obtain a synthetic resin optical transmission body having a desired refractive index distribution. However, in the above method, the base material is immersed in the liquid monomer Mb, and the base material surface and the liquid monomer Mb are immersed.
Direct contact with Mb had some disadvantages. For example, when diffusion and polymerization of the monomer Mb are carried out simultaneously, the dipping temperature must be relatively high, and the polymerization initiator normally contained in the base material will liquefy as the dipping time passes. Since it is eluted into the phase, monomer Mb gradually polymerizes even in the liquid phase and becomes viscous. As a result, when the base material is removed from the liquid phase after diffusion, the viscous layer thus formed remains attached to the surface of the base material. During the heat treatment process to complete the polymerization, the monomer Mb leaches out from this viscous layer and diffuses into the base material, causing undesirable distortion of the refractive index near the outer periphery of the resulting light transmitting body. It causes the increase. However, if a polymerization inhibitor is added to suppress the polymerization of monomer Mb in the liquid phase, it will diffuse into the base material at the same time as monomer Mb and prevent the completion of polymerization in the heat treatment process. inhibit. In addition, if the monomer Mb is polymerized after being diffused, a relatively low immersion temperature is required, but in this case, the diffused monomer Mb evaporates from the outer periphery of the base material during the heat treatment process. This causes an increase in undesirable distortion in the refractive index distribution near the outer periphery. The method described in JP-A-54-119939 is an improvement on the above-mentioned method to avoid distortion of the refractive index distribution near the outer periphery. According to this method, monomeric Mb is diffused in the gas phase. That is, the base material is placed in a vapor atmosphere of the monomer Mb for a predetermined period of time, the monomer Mb is diffused into the base material, and at the same time as this diffusion, the monomer Mb is partially polymerized,
Finally, the polymerization is completed by heat treatment. In this method, the base material is monomer Mb in liquid phase.
Since it comes into contact with the monomer Mb in the gas phase rather than with the gas, it has the following advantages. (1) Excess monomer Mb does not adhere to the surface of the base material. Therefore, monomeric Mb deposited during the heat treatment process
does not diffuse into the interior from the surface of the base material.
Furthermore, since the diffusion is carried out at a high temperature, the monomer Mb is polymerized and fixed while diffusing inside the base material. Therefore, the monomer Mb does not evaporate from the outer periphery of the base material during the heat treatment process. Therefore, it is possible to obtain an optical transmission body in which the distortion of the refractive index at the outer peripheral portion is small and the desired refractive index distribution is provided over a wide range. (2) Polymerization of monomer Mb in the liquid phase can be prevented by adding a polymerization inhibitor to liquid monomer Mb, which is a source of vapor of monomer Mb.
At that time, if a polymerization inhibitor with low vapor pressure is used,
Since it hardly evaporates, it does not diffuse into the base material, and therefore, polymerization is not inhibited during the heat treatment process. Furthermore, by adjusting the supply rate of monomer Mb, there is no need to add a polymerization inhibitor, making it possible to use monomer Mb many times and increasing its recovery rate. However, this method has the following drawbacks. In other words, the process of forming the base material, the monomer
Both the process of diffusing Mb and the heat treatment process are performed using the batch method, so there may be variations in the composition of the formed base material, the temperature inside the diffusion device, the monomer
If the Mb vapor concentration or the temperature inside the heat treatment equipment varies even slightly from place to place, the properties of the resulting optical transmission body will become non-uniform, making it difficult to manufacture an optical transmission body of constant quality. This kind of disadvantage is
The above-mentioned Japanese Patent Publication No. 52-5857 and Japanese Patent Application Laid-open No. 1973-
The same applies to the method described in Publication No. 8857, and the conventional batch method was unavoidable in any case. This invention was completed after intensive research in view of the above points, and aims to make all of the steps of forming the base material, diffusing monomer Mb, and heat treatment continuous. The aim is to make it possible to efficiently manufacture, for example, optical transmission bodies of constant quality with a diameter of 1 to 20 mm. That is, in this invention, when forming the base material, monomer Ma is prepolymerized to express plastic flow using the general formula: D=Kσ n (where D is the shear rate, σ is the shear stress, and K is the plasticity A prepolymer exhibiting plastic flow with a value of n of 1.10 or more at 20°C (inverse of viscosity, n represents a constant) is obtained, and then this prepolymer is supplied to a long and narrow passage and allowed to flow through this passage. The present invention relates to a method of manufacturing a synthetic resin light transmitting body, characterized in that the base material is obtained by heating and polymerizing the base material while molding the base material. Next, an embodiment of the method for manufacturing a synthetic resin optical transmission body according to the present invention will be described using the apparatus shown in the drawings. First, a monomer Ma that produces a network polymer Pa having a refractive index of Na is prepolymerized to produce a viscous fluid (prepolymer) that maintains fluidity just before gelation. This prepolymer is placed in an extruder 1 of the apparatus shown in FIG. 1, and is continuously extruded while being cooled once with cooling water. In this invention, the prepolymer is expressed by the general formula: D=Kσ n (4) (where D is shear rate, σ is shear stress, K is the reciprocal of plastic viscosity, and n is a constant). It is important to demonstrate plastic flow in which the value of n at 20°C in the general equation for non-Newtonian fluids (Ostwald's power law) is 1.10 or more. When a fluid similar to a Newtonian fluid, such as a monomer or a low-viscosity prepolymer, is introduced into a long and thin tube and is heated and polymerized while passing through the tube, the heat is applied from the outside of the tube, so Polymerization progresses from the peripheral region, and the viscosity increases accordingly.The fluid flowing inside the pipe originally has a velocity distribution in which the flow velocity is maximum at the center and decreases parabolically toward the periphery. However, as the polymerization progresses, this speed difference between the peripheral region and the central region becomes larger. In the end, the fluid in the peripheral region gels first and stays in the tube, while the fluid in the central region flows out of the tube without polymerizing. In order to correct this, it is necessary to make the velocity distribution of the fluid within the pipe as constant as possible. That is, it is sufficient to bring the fluid in the pipe closer to Bingham fluid. In the case of Bingham fluid, n=∞ in the above equation (4), and the flow rate of the fluid in the pipe is constant.
As n becomes smaller and approaches 1, the fluid approaches a Newtonian fluid. In addition, the flow velocity of the fluid near the inner wall of the pipe does not change much depending on the value of n; in fact, the flow velocity increases as n increases;
As n approaches 1, the flow velocity near the center increases, and as a result, the difference in flow velocity between the peripheral region and the center region increases, and the parabola of the velocity distribution becomes sharp. From this point of view, in this invention, the monomer Ma is prepolymerized as described above, and the value of n is 1.10.
The above-mentioned viscous fluid is then sent into the pipe. In other words, if the value of n is less than 1.10, if the surrounding area is first gelled, the monomer Ma near the center will flow out from the tube without being polymerized.
A good base material cannot be formed. In this case, if the flow rate is extremely reduced, the base metal will not be formed, but productivity will be poor and this is not practical. Further, preferably the value of n is at most 1.50. This is because if the value of n is too large, it becomes difficult to push the material into the pipe, and the base material becomes non-uniform, causing problems. Note that the value of K and the value of n in the above equation (4) can be determined using a viscometer (for example, a rotational viscometer). That is, after changing the rotational speed of the viscometer (which determines D) and measuring each σ, these values are plotted on a graph to determine the values of K and n. The prepolymer 10 that satisfies these conditions is
After being extruded, it is then continuously introduced into a Teflon tube 3 passing through a heating jacket 2, such as a brass block. The Teflon tube 3 may have a circular cross section and a diameter of 1 to 20 mm. Here, if the lower end of the stainless steel tube is inserted into the Teflon tube 3 from above in advance, the tip of the prepolymer 10 will gel while in contact with the lower end of the stainless steel tube. and the tip of the prepolymer 10 are integrally bonded. After this, when the stainless steel tube is pulled up with a pulling device at the same speed as the extrusion speed, the accompanying prepolymer becomes a light transmitter during the entire manufacturing process and is produced continuously and without stagnation in the device. It comes out. Heating jacket 2 has
Relatively high temperature water 16 is supplied to the upper part, and lower temperature water 17 is supplied to the lower part, and the Teflon tube 3 is heated with a temperature gradient such that the temperature gradually increases from the lower part to the upper part. There is. Then, while passing through the Teflon tube 3, the prepolymer 10 is polymerized and gelled by heating, and this gelled prepolymer becomes the base material 11. The heating rate during this thermal polymerization is preferably 0.1 to 10°C/min. When heated under the temperature gradient described above, both the polymerization of the prepolymer 10 and the accompanying increase in viscosity proceed gradually. It becomes possible to make it flow. As a result, it becomes possible to continuously form the base material 11 having a uniform composition in the radial direction.
Note that the Teflon tube 3 is particularly useful here because it has low friction with the prepolymer 10 and the base material 11, but tubes made of other resins or metals may also be used. In this way, the Teflon tube 3 in the heating jacket 2 produces a gel-like base material 11 that has almost lost its fluidity and has self-shape retention. This base material 11 contains components insoluble in acetone,
That is, it preferably contains a network polymer portion of 5 to 90% by weight, more preferably 10 to 50% by weight. If this component is too small, the fluidity becomes high, and if it is too large, the diffusion rate of monomer Mb becomes too slow in the subsequent diffusion step, which is not preferable. Subsequently, the base material 11 is sent to the vapor phase diffusion device 4. A diffusion chamber 4b inside this device is filled with an atmosphere containing monomer Mb vapor supplied from a steam generator 14 through an inlet 19. The monomer Mb vapor is recovered from the outlet 20 by the vacuum pump 15. While the base material 11 remains in the above atmosphere for a certain period of time, the monomer in the gas phase
Mb reaches the circumferential surface of the base material 11 and diffuses and moves from the circumferential surface in the radial direction of the base material 11. As a result, a concentration gradient is created in the base material 11 in which the concentration of the monomer Mb gradually increases from the central axis toward the peripheral surface in a square approximation. Further, the diffusion device 4 is provided with an outer tube 4a surrounding the diffusion chamber 4b, and this outer tube 4a has an inlet 21 and an outlet 2.
Hot water 18 is flowing into 2. By heating the inside of the diffusion chamber 4b with this hot water 18, the monomer
Part of Mb is diffused and used alone or in the base material 11.
It polymerizes with the prepolymer, etc. inside, and the above concentration gradient is fixed. The atmosphere containing monomer Mb vapor is formed after the air is evacuated or replaced with nitrogen to avoid inhibition of polymerization by oxygen. Also, the temperature is
As in the case of known methods, the temperature is set at, for example, 5 to 90° C., since monomer Mb has a relatively high vapor pressure and must be maintained at a value that allows it to diffuse into the base material. The higher this temperature, the more monomer
Although the diffusion rate of Mb increases, the polymerization rate of the base material itself also increases, which is not preferable. Also,
The time for which the base material is allowed to stay in an atmosphere containing monomer Mb vapor (diffusion time) and the above diffusion temperature depend on the refractive index gradient of the desired optical transmission body, that is, the above concentration gradient of monomer Mb. You can decide accordingly.
However, if this diffusion time is extremely long or the diffusion temperature is too high, the concentration gradient of monomer Mb may become flat, or the concentration gradient may suddenly become large near the outer periphery of the base material. The desired refractive index gradient cannot be obtained. After diffusing the monomer Mb, the base material 11 is guided from the diffusion device to the heat treatment tube 5. This heat treatment tube 5 is heated by a heater 13, but it is also possible to form a temperature gradient by increasing the temperature of this heater 13 stepwise from the bottom to the top of the device. good. The inside of this heat treatment tube 5 is also purged with nitrogen. Here, the base material 11 is further heated to complete polymerization. The refractive index of the optical transmission material obtained in this way is determined by the monomer as described below.
The combination of Ma and monomer Mb has a refractive index gradient that continuously increases or decreases in the radial direction approximately in proportion to the square of the distance from the central axis. This refractive index does not change in the length direction of the optical transmission body and remains constant. In the embodiments described above, a gas phase diffusion method is adopted, but a liquid phase diffusion method can also be used. In the case of gas phase diffusion, at least the inside of the diffusion device may be maintained under a constant reduced pressure in order to form and maintain an atmosphere containing the vapor of the monomer Mb. However, if the boiling point of the monomer Mb is relatively low, it is also possible to carry out the reaction at normal pressure.
In the case of the gas phase diffusion method carried out at normal pressure, Figures 2 and 3
It can be carried out by the following methods (a) and (b) using the gas phase diffusion device 4 shown in the figure. (a) Liquid monomer Mb is supplied from the inlet 24 at the top of the gas phase diffusion device 4 and is then stored in the monomer reservoir 6. The overflowing liquid monomer Mb flows down through the very narrow slit 7, and then flows down along the inner surface 8. This inner surface 8 is heated by hot water 18 passed through the outer tube 4a, and the monomer flowing down is heated.
Evaporate Mb. Also, nitrogen gas is inlet 25
The monomer Mb is introduced from the exhaust port 20 and collected together with the vaporized monomer Mb into the pump through the discharge port 20. The liquid monomer Mb that has flowed down without being vaporized is recovered through the outlet 26. (b) Monomer Mb is introduced into the monomer reservoir 6 at the bottom of the diffusion device, and a thin nozzle 2 is inserted into the monomer Mb.
By injecting nitrogen gas from 3 or the like to generate nitrogen bubbles, the vaporization of monomer Mb is promoted and the diffusion chamber 4b is filled with the vapor of monomer Mb. In the embodiments described above, the step of forming the base material,
Although the step of diffusing monomer Mb and the heat treatment step are all performed continuously, the manufacturing method of the present invention is also applicable to a batch method in which all or some of the steps are performed separately. In the method of this invention, the monomer Ma used is a monomer that can be polymerized to form a transparent network polymer Pa having a refractive index of Na; It may be a monomer or a mixture of multiple types of monomers. Such a monomer Ma has two or more groups each containing a double bond such as an allyl group, an acrylic acid group, a methacrylic acid group, and a vinyl group, or it has two or more of these groups at the same time. Monomers are preferred. Next, a specific example of monomer Ma will be given. (1) Allyl compounds and mixtures thereof. Diallyl esters such as diallyl phthalate, diallyl isophthalate, diallyl terephthalate, and diethylene glycol bisallyl carbonate; triallyl esters such as triallyl trimellitate, triallyl phosphate, and triallyl phosphite; unsaturated materials such as allyl methacrylate and allyl acrylate Acid allyl ester. (2) A compound represented by R 1 −R 2 −R 3 and a mixture thereof. A compound in which both R 1 and R 3 are a vinyl group, an acrylic acid group, a vinyl ester group, or a methacrylic acid group; either one of R 1 and R 3 is a vinyl group, an acrylic acid group, a methacrylic acid group, or a vinyl ester Any of the four groups of the group,
A compound where the other is any of the remaining three groups. Here, R 2 can be selected from the divalent groups shown below. (3) A mixture of the monomers (1) and (2) above, or at least one of the five monovinyl compounds, vinyl esters, acrylic esters, and methacrylic esters and the above (1) or A mixture with the monomer (or mixture thereof) of (2). In this invention, the monomer Mb is selected from a monomer which forms a transparent polymer Pb having a refractive index Nb greater than or less than the above-mentioned refractive index Na when it is polymerized. Monomer Mb may be a single monomer or a mixture of multiple types of monomers. The polymer Pb may be either a reticular polymer or a linear polymer. Refractive index Nb is the refractive index
When smaller than Na, the resulting optical transmission body is as above.
It has a convex lens action with a refractive index distribution as expressed by equation (1). Conversely, the refractive index
When Nb is larger than the refractive index Na, an optical transmission body having a concave lens effect can be obtained with the refractive index distribution expressed by the above equation (3). The difference between these refractive indices｜Na
−Nb| is preferably 0.005 or more; if this difference is too small, the desired refractive index gradient cannot be obtained.
Moreover, especially when monomeric Mb is diffused in the gas phase,
Preferably, it has a relatively high vapor pressure, for example a saturated vapor pressure of greater than 5 mm Hg at the diffusion temperature. Examples of such monomers Mb include styrene, methacrylates, acrylates, vinyl acetate, vinyl chloride, acrylonitrile, butadiene and mixtures thereof. Preferred examples of the combination of the network polymer Pa and the monomer Mb of the present invention include the following combinations in addition to examples suitable for manufacturing a light transmitting body with low chromatic aberration as described below. First, when Na > Nb, diallyl phthalate polymer - methyl methacrylate, diallyl phthalate polymer - mixture of methyl acrylate and methyl methacrylate, diallyl isophthalate polymer -
Methyl methacrylate, copolymer of diallyl phthalate and styrene - methacrylate ester,
Copolymer of diallyl isophthalate and styrene -
Acrylic ester, copolymer of divinyl phthalate and divinyl benzoate - methacrylic ester, copolymer of divinyl isophthalate and vinyl benzoate - methacrylic ester, copolymer of vinyl benzoate and diallyl isophthalate -methacrylic acid esters, etc. Examples of the case where Na<Nb include diethylene glycol bisallyl carbonate polymer-styrene, diethylene glycol bisallyl carbonate polymer-diallyl isophthalate, and the like. In particular, the following combinations of monomer Ma and monomer Mb are suitable for producing a synthetic resin light transmitting body with low chromatic aberration. (a) Diethylene glycol bisallyl carbonate as Ma, or a mixture thereof with diallyl phthalate, diallyl isophthalate, vinyl benzoate or styrene (provided that the amount of diethylene glycol bisallyl carbonate in this mixture is not less than 50% by weight) (more preferably 70% by weight or more).
Compound (A) as Mb: [Wherein, X is a hydrogen atom or a methyl group, Y is a phenyl group, a methylphenyl group, a vinyl group, i
-propyl group, i-butyl group, s-butyl group,
t-butyl group,
【式】（ｘ＝０〜２）、[Formula] (x=0-2),
【式】（ｙ＝０〜２）およ
び
（―CH2CH2O）―zCH3（ｚ＝１〜３）からなる
群から選ばれた基を表わす。〕
で表わされる化合物またはその混合物。
(b) Maとしてジエチレングリコールビスアリル
カーボネート、またはこれとアクリル酸メチ
ル、アクリル酸エチル、メタクリル酸ｎ−ブチ
ルもしくはメタクリル酸ｔ−ブチルとの混合物
（ただし、この混合物中のジエチレングリコー
ルビスアリルカーボネートの量は10重量％以上
であるのが好ましい）。Mbとして、化合物
(B)：
〔式中、Ｘは水素原子またはメチル基であ
り、Ｙは−（CF2）iＦ（ｉ＝１〜６），−CH2
（CF2）jＨ（ｊ＝１〜８），−CH2CH2OCH2CF3，
−（CH2CH2O）kCF2CF2H（ｋ＝１〜４），−
CH2CH2OCH2（CF2）lＦ（ｌ＝１〜６），−CH2
（CF2）nＯ（CF2）oＦ（ｍ＝１〜２，ｎ＝１〜４）
からなる群より選ばれた基を表わす。〕
で表わされるメタクリル酸またはアクリル酸の
含フツ素アルコールエステルや、上記一般式(B)
においてＹが−Si（OC2H5）3である化合物(C)。
(c) 単量体Maとしてジエチレングリコールビス
アリルカーボネートと上記化合物(B)または(C)と
の混合物（ただし、この混合物中のジエチレン
グリコールビスアリルカーボネートの量は10重
量％以上であるのが好ましい）。単量体Mbと
して上記化合物(A)。
次にこの発明の具体例を示す。
具体例 １
重合開始剤として3.0重量％の過酸化ベンゾイ
ル（BPO）を溶解させたジエチレングリコール
ビスアリルカーボネート（CR−39）を75℃で65
分間加熱して予備重合し、ゲル化直前で流動性を
保持しているプレポリマーを得た。このプレポリ
マーの粘度は20℃で1015cpであり、上記(4)式に
おけるＫおよびｎの値はそれぞれ2.57×10-2cm
2dyne-1sec-1および1.21であつた。このプレポリ
マー１０を第１図に示す装置の押出し器１に入
れ、加熱ジヤケツト２を貫通しているテフロンチ
ユーブ３（直径４mm、長さ200mm）の中へ6.3×
10-2ml／minの一定流量で連続的に送り込んだ。
加熱ジヤケツト２には上部に78℃の温水１６、下
部に58℃の温水１７をそれぞれ流すことによつて
温度勾配を形成させた。テフロンチユーブ中を40
分間で通過する間にプレポリマー１０はゲル化
し、４mmφの母材１１に成形された。この母材１
１はアセトンに不溶な成分（網状重合体部分）25
重量％、アセトンに可溶だがタノールに不溶の成
分（線形重合体部分）５重量％、アセトンとメタ
ノールの両方に可溶な成分（単量体および低分子
量プレポリマー部分）70重量％から成つていた。
次いで、母材１１を引上げ装置によつて0.52
cm／分の一定速度で気相拡散装置４に送り込み、
ここでメタクリル酸−２，２，２−トリフルオロ
エチル（3FMA）の蒸気を含む雰囲気中の約40分
滞留させて、3FMAの拡散および一部重合を行わ
せた。3FMAには予め重合禁止剤としての0.01重
量％ハイドロキノン（HQ）を溶解させておき、
蒸気発生器１４内で気化させてから導入口１９を
介して拡散室４ｂ内に導入した。また3FMAの蒸
気をポンプ１５によつて排出口２０から回収しト
ラツプで液化させたところ、この3FMAはほとん
ど重合していなかつたので繰返し使用できた。な
お、拡散室４ｂには、3FMAを導入する前に1000
mg／分の流量で窒素ガスを流入させて、系内の空
気を予め窒素置換しておいた。この拡散室４ｂの
下部の温度は80℃であり、外側管４ａ中に流した
温水１８の温度は80℃であつた。
拡散装置４を経て母材１１を、続いて窒素置換
した熱処理管５に送り込んだ。この熱処理管５
を、ヒータ３によつて下部から順次、90℃，110
℃，120℃，130℃に加熱し、温度勾配を形成させ
た。この熱処理管５内で母材を６時間熱処理して
重合を完結させた。
このようにして連続的に作製した直径４mmの棒
状体からは、均一な光学性能を有する棒状凸レン
ズ、すなわち所望の光伝送体が得られた。この棒
状体は、上記(1)式中のＡの値が2.19×10-2mm-2の
光伝送体であり、この棒状体中を蛇行して進行す
る光束の周期Ｌ（式(2)）は42.5mmであつた。また、
この棒状体にはほとんど外周部まで式(1)で表わさ
れるような屈折率分布が形成されていたので、周
辺部を削り落とす必要がなかつた。さらに、凸レ
ンズとしての評価の値、開口数NAも0.44と大き
かつた。
具体例 ２
具体例１と同様にして得たCR−39の母材を第
３図に示した気相拡散装置４中に送り込み、
3FMAの蒸気を含む雰囲気中に約48分間滞留させ
ることによつて拡散および一部重合させた。ここ
で拡散装置４の下部のモノマー溜め６中の3FMA
の温度は80℃、外側管４ａ中に流れている温水１
８の温度は80℃であつた。また、3FMAには重合
禁止剤を添加せずに用い、この3FMAを1.0ml／
分の一定流量で導入してノズル２３でバブルさ
せ、3FMAの気圧を促進させた。さらに気化した
3FMAはポンプにより800ml／分の流量で排出口
２０から回収し、トラツプで液化させた。この回
収した3FMAはほとんど重合しておらず、また重
合禁止剤を含んでいないのでそのまま繰り返し使
用できた。拡散後、母材を具体例１と同様に熱処
理することによつて所望の棒状光伝送体が連続的
に製造できた。
この具体例にも、得られた棒状体にはほとんど
外周部まで式(1)で表わされる屈折率分布が形成さ
れており、その開口数NAも0.43と大きかつた。
具体例 ３
0.10重量％のBPOを溶解させたテトラエチレン
グリコールジメタクリリレート（4ED）を50℃で
10分間加熱して、20℃での粘度が950cp、Ｋ＝
3.35×10-2cm-2dyne-1sec-1、およびｎ＝1.18のプ
レポリマーを得た。
得られたプレポリマー１０を、具体例１と同様
に押出し器１に入れ、さらに、上部に55℃の温水
１６、下部に25℃の温水１７をそれぞれ流した加
熱ジヤケツト３を貫通しているテフロンチユーブ
（内径４mm、長さ200mm）３に、6.0×10-2ml／分
の一定流量で連続的に送り込んだ。このテフロン
チユーブ３を通過する間に、プレポリマー１０は
ゲル化して直径４mmの円筒状で透明な母材１１に
成形された。この母材１１はアセトンに不溶の成
分（網状重合体部分）21重量％、アセトンに可溶
でかつメタノールに不溶の成分（線形重合体部
分）１重量％およびアセトンとメタノールの両方
に可溶の成分（単量体および低分子量プレポリマ
ー）78重量％からなつていた。
次いで、この母材１１を引き上げ装置によつて
0.48cm／分の一定速度で第３図に示した気相拡散
装置４に送り込んだ。この装置の下部のモノマー
溜めには3FMAを1.0ml／分の一定流量で供給し
た。そして、モノマー溜め中の3FMAに200ml／
分の流量で窒素ガスをノズル２３から吹込んで
3FMAを気化させた。さらに、熱処理管５上部の
窒素ガス送入口から1100ml／分の流量で窒素ガス
を送入すると同時にポンプを作動させて800ml／
分の流量で吸気して、拡散室４ｂ内に3FMAの蒸
気を含んだ窒素流を形成させた。なお、モノマー
溜めおよび外側管４ａの温度は共に55℃であつ
た。この拡散装置４内に約52分間母材１１を滞留
させることによつて、3FMAを拡散および一部重
合させた。拡散後、母材１１を熱処理管５（長さ
1400mm）に導き、５時間滞留させて重合を完結さ
せた。熱処理管５には下部から順次55℃、70℃、
85℃および100℃に加熱することによつて温度勾
配を形成させた。このようにして所望の棒状光伝
送体が連続的に製造できた。この光伝送体では、
屈折率分布を有する部分の半径が1.68mm（全体の
84％）であり、Ａ＝1.87×10-2mm-2、Ｌ＝45.0mm
であつた。また中心の直径3.3mmの部分は、開口
数NA＝0.34の棒状凸レンズであつた。[Formula] represents a group selected from the group consisting of (y=0-2) and (-CH 2 CH 2 O)- z CH 3 (z=1-3). ] A compound represented by or a mixture thereof. (b) Diethylene glycol bisallyl carbonate as Ma, or a mixture thereof with methyl acrylate, ethyl acrylate, n-butyl methacrylate or t-butyl methacrylate (however, the amount of diethylene glycol bisallyl carbonate in this mixture is 10 % by weight or more). As Mb, the compound
(B)： [In the formula, X is a hydrogen atom or a methyl group, and Y is -(CF 2 ) i F (i = 1 to 6), -CH 2
(CF 2 ) j H (j=1 to 8), -CH 2 CH 2 OCH 2 CF 3 ,
−(CH 2 CH 2 O) k CF 2 CF 2 H (k=1 to 4), −
CH 2 CH 2 OCH 2 (CF 2 ) l F (l = 1 to 6), -CH 2
(CF 2 ) n O (CF 2 ) o F (m=1-2, n=1-4)
represents a group selected from the group consisting of ] Fluorine-containing alcohol ester of methacrylic acid or acrylic acid, or the above general formula (B)
A compound (C) in which Y is -Si( OC2H5 ) 3 . (c) A mixture of diethylene glycol bisallyl carbonate as the monomer Ma and the above compound (B) or (C) (however, the amount of diethylene glycol bisallyl carbonate in this mixture is preferably 10% by weight or more). The above compound (A) as monomer Mb. Next, a specific example of this invention will be shown. Specific example 1 Diethylene glycol bisallyl carbonate (CR-39) in which 3.0% by weight of benzoyl peroxide (BPO) was dissolved as a polymerization initiator was heated at 75℃ for 65 minutes.
The mixture was prepolymerized by heating for a minute to obtain a prepolymer that maintained fluidity just before gelation. The viscosity of this prepolymer is 1015 cp at 20°C, and the values of K and n in the above equation (4) are each 2.57 × 10 -2 cm
2 dyne -1 sec -1 and 1.21. This prepolymer 10 was put into an extruder 1 of the apparatus shown in FIG.
It was fed continuously at a constant flow rate of 10 -2 ml/min.
A temperature gradient was created by flowing hot water 16 at 78°C in the upper part of the heating jacket 2 and hot water 17 at 58°C in the lower part. 40 in Teflon tube
The prepolymer 10 gelled during the passage of time and was molded into a base material 11 with a diameter of 4 mm. This base material 1
1 is a component insoluble in acetone (reticular polymer part) 25
% by weight, 5% by weight of components soluble in acetone but insoluble in ethanol (linear polymer portion), and 70% by weight of components soluble in both acetone and methanol (monomer and low molecular weight prepolymer portion). was. Next, the base material 11 is pulled up to 0.52
into the gas phase diffusion device 4 at a constant speed of cm/min,
Here, the mixture was allowed to remain in an atmosphere containing vapor of 2,2,2-trifluoroethyl methacrylate (3FMA) for about 40 minutes to cause diffusion and partial polymerization of 3FMA. 0.01% by weight hydroquinone (HQ) as a polymerization inhibitor was dissolved in 3FMA in advance.
After being vaporized in the steam generator 14, it was introduced into the diffusion chamber 4b through the inlet 19. Further, when the vapor of 3FMA was collected from the outlet 20 by the pump 15 and liquefied in a trap, the 3FMA was hardly polymerized and could be used repeatedly. In addition, before introducing 3FMA into the diffusion chamber 4b, 1000
The air in the system was replaced with nitrogen in advance by flowing nitrogen gas at a flow rate of mg/min. The temperature of the lower part of this diffusion chamber 4b was 80°C, and the temperature of the hot water 18 flowing into the outer tube 4a was 80°C. The base material 11 was sent through the diffusion device 4 into a heat treatment tube 5 which was then purged with nitrogen. This heat treatment tube 5
are heated to 90℃ and 110℃ sequentially from the bottom by heater 3.
℃, 120℃, and 130℃ to form a temperature gradient. The base material was heat treated in this heat treatment tube 5 for 6 hours to complete polymerization. From the rod-shaped bodies having a diameter of 4 mm that were continuously produced in this manner, a rod-shaped convex lens having uniform optical performance, that is, a desired light transmission body was obtained. This rod-shaped body is an optical transmission body in which the value of A in the above equation (1) is 2.19×10 -2 mm -2 , and the period L of the light flux that meanders through this rod-shaped body (equation (2) ) was 42.5mm. Also,
Since this rod-shaped body had a refractive index distribution expressed by equation (1) almost up to the outer periphery, there was no need to shave off the periphery. Furthermore, the evaluation value as a convex lens, the numerical aperture NA, was large at 0.44. Concrete Example 2 A base material of CR-39 obtained in the same manner as in Concrete Example 1 was sent into the vapor phase diffusion device 4 shown in FIG.
Diffusion and partial polymerization occurred by residence in an atmosphere containing 3FMA vapor for approximately 48 minutes. Here, 3FMA in the monomer reservoir 6 at the bottom of the diffuser 4
The temperature of the hot water 1 flowing into the outer pipe 4a is 80℃.
The temperature at No. 8 was 80°C. In addition, 3FMA was used without adding a polymerization inhibitor, and this 3FMA was added at 1.0ml/
It was introduced at a constant flow rate of 300 min and bubbled through the nozzle 23 to promote an air pressure of 3FMA. even more vaporized
3FMA was collected from the outlet 20 by a pump at a flow rate of 800 ml/min and liquefied in a trap. This recovered 3FMA was hardly polymerized and did not contain a polymerization inhibitor, so it could be used repeatedly as is. After the diffusion, the base material was heat-treated in the same manner as in Example 1, so that the desired rod-shaped light transmitting body could be continuously manufactured. In this specific example as well, the obtained rod-shaped body had a refractive index distribution expressed by the formula (1) almost to the outer periphery, and its numerical aperture NA was as large as 0.43. Specific example 3 Tetraethylene glycol dimethacrylate (4ED) in which 0.10% by weight of BPO was dissolved was heated at 50°C.
Heated for 10 minutes, viscosity at 20℃ is 950cp, K=
A prepolymer of 3.35×10 −2 cm −2 dyne −1 sec −1 and n=1.18 was obtained. The obtained prepolymer 10 was placed in an extruder 1 in the same manner as in Example 1, and a Teflon tube was inserted through a heating jacket 3 in which hot water 16 at 55°C was flowed in the upper part and hot water 17 at 25°C in the lower part. It was continuously fed into the tube (inner diameter 4 mm, length 200 mm) 3 at a constant flow rate of 6.0 x 10 -2 ml/min. While passing through this Teflon tube 3, the prepolymer 10 was gelled and formed into a cylindrical transparent base material 11 with a diameter of 4 mm. This base material 11 contains 21% by weight of a component insoluble in acetone (reticular polymer portion), 1% by weight of a component soluble in acetone and insoluble in methanol (linear polymer portion), and soluble in both acetone and methanol. It consisted of 78% by weight of components (monomers and low molecular weight prepolymers). Next, this base material 11 is pulled up by a pulling device.
It was fed into the gas phase diffusion device 4 shown in FIG. 3 at a constant speed of 0.48 cm/min. 3FMA was fed into the monomer reservoir at the bottom of the device at a constant flow rate of 1.0 ml/min. Then, add 200ml to 3FMA in the monomer reservoir.
Blow nitrogen gas from the nozzle 23 at a flow rate of
3FMA was vaporized. Furthermore, nitrogen gas was introduced from the nitrogen gas inlet at the top of the heat treatment tube 5 at a flow rate of 1100 ml/min, and at the same time the pump was activated to produce 800 ml/min.
Air was taken in at a flow rate of 3 FMA to form a nitrogen flow containing 3 FMA vapor in the diffusion chamber 4b. Note that the temperatures of the monomer reservoir and the outer tube 4a were both 55°C. 3FMA was diffused and partially polymerized by allowing the base material 11 to remain in this diffusion device 4 for about 52 minutes. After diffusion, the base material 11 is transferred to a heat treatment tube 5 (length:
1400 mm) and allowed to stay there for 5 hours to complete polymerization. Heat treatment tube 5 is heated to 55℃, 70℃, and 70℃ sequentially from the bottom.
A temperature gradient was created by heating to 85°C and 100°C. In this way, desired rod-shaped light transmitters could be continuously manufactured. In this optical transmission body,
The radius of the part with refractive index distribution is 1.68 mm (total
84%), A=1.87×10 -2 mm -2 , L=45.0mm
It was hot. The central portion with a diameter of 3.3 mm was a rod-shaped convex lens with a numerical aperture NA of 0.34.
第１図はこの発明の製造方法を実施するのに使
用可能な製造装置の一例を示す縦断面図、第２図
および第３図は、第１図に示した製造装置の気相
拡散装置を変形した別の例をそれぞれ示す気相拡
散装置の縦断面図である。
なお図面に用いた符号において、１…押出し
器、２…加熱ジヤケツト、３…テフロンチユー
ブ、４…気相拡散装置、５…熱処理管、１０…プ
レポリマー、１１…母材、１２…合成樹脂光伝送
体、である。
FIG. 1 is a longitudinal sectional view showing an example of a manufacturing apparatus that can be used to carry out the manufacturing method of the present invention, and FIGS. 2 and 3 show a vapor phase diffusion device of the manufacturing apparatus shown in FIG. FIG. 7 is a vertical cross-sectional view of a gas phase diffusion device showing other modified examples. In addition, in the symbols used in the drawings, 1...extruder, 2...heating jacket, 3...Teflon tube, 4...vapor phase diffusion device, 5...heat treatment tube, 10...prepolymer, 11...base material, 12...synthetic resin light It is a transmission body.
Claims (1)
Maを不完全に重合させて自己保形性を有する母
材を形成し、屈折率Naとは異なる屈折率Nbを有
する重合体Pbを生成する単量体Mbを、上記母材
の表面からその内部へ拡散させると共に重合させ
るようにした屈折率分布を有する合成樹脂光伝送
体の製造方法において、前記母材を形成するに際
し、単量体Maを予備重合させて塑性流動を表わ
す一般式： Ｄ＝Kσn （式中、Ｄはずり速度、σはずり応力、Ｋは塑
性粘度の逆数、ｎは定数をそれぞれ表わす。） における20℃でのｎの値が1.10以上である塑性流
動を示すプレポリマーを得、次いでこのプレポリ
マーを細長い通路に供給して、この通路を進行さ
せつつ加熱重合させることによつて前記母材を得
ることを特徴とする合成樹脂光伝送体の製造方
法。 ２ ｎの値が1.10以上1.50以下であることを特徴
とする特許請求の範囲第１項に記載の合成樹脂光
伝送体の製造方法。 ３ 細長い通路を進行しつつあるプレポリマーの
加熱重合を毎分0.1〜1.0℃の加熱速度で行うこと
を特徴とする特許請求の範囲第１項に記載の合成
樹脂光伝送体の製造方法。 ４ 細長い通路が円形断面を有することを特徴と
する特許請求の範囲第１項に記載の合成樹脂光伝
送体の製造方法。[Claims] 1. Monomer that produces a network polymer Pa having a refractive index of Na
Ma is incompletely polymerized to form a self-shape-retaining base material, and the monomer Mb, which produces a polymer Pb having a refractive index Nb different from the refractive index Na, is removed from the surface of the base material. In a method for manufacturing a synthetic resin light transmission body having a refractive index distribution that is diffused into the interior and polymerized, when forming the base material, monomer Ma is prepolymerized to express plastic flow using the general formula: D = Kσ n (where D is the shear rate, σ is the shear stress, K is the reciprocal of the plastic viscosity, and n is the constant). 1. A method for producing a synthetic resin optical transmitter, characterized in that the base material is obtained by obtaining a polymer, then supplying this prepolymer to a long and narrow passage, and heating and polymerizing the prepolymer while advancing the passage. 2. The method for manufacturing a synthetic resin optical transmission body according to claim 1, wherein the value of n is 1.10 or more and 1.50 or less. 3. The method for producing a synthetic resin optical transmission body according to claim 1, characterized in that the prepolymer progressing through the elongated path is heated and polymerized at a heating rate of 0.1 to 1.0°C per minute. 4. The method of manufacturing a synthetic resin optical transmission body according to claim 1, wherein the elongated passage has a circular cross section.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58120627A JPS6012509A (en) | 1983-07-02 | 1983-07-02 | Production of optical transmission body made of synthetic resin |
| US06/626,697 US4587065A (en) | 1983-07-02 | 1984-07-02 | Method for producing light transmitting article of synthetic resin |
| EP84304531A EP0130838B1 (en) | 1983-07-02 | 1984-07-02 | Method and apparatus for producing light transmitting article of synthetic resin |
| DE8484304531T DE3466660D1 (en) | 1983-07-02 | 1984-07-02 | Method and apparatus for producing light transmitting article of synthetic resin |
| US06/827,468 US4689000A (en) | 1983-07-02 | 1986-02-10 | Apparatus for producing light transmitting article of synthetic resin |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP58120627A JPS6012509A (en) | 1983-07-02 | 1983-07-02 | Production of optical transmission body made of synthetic resin |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6012509A JPS6012509A (en) | 1985-01-22 |
| JPH0259961B2 true JPH0259961B2 (en) | 1990-12-14 |
Family
ID=14790903
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP58120627A Granted JPS6012509A (en) | 1983-07-02 | 1983-07-02 | Production of optical transmission body made of synthetic resin |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6012509A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62215204A (en) * | 1986-03-17 | 1987-09-21 | Mitsubishi Rayon Co Ltd | Production of plastic optical transmission body |
| JPH075812B2 (en) * | 1987-10-20 | 1995-01-25 | 三菱レイヨン株式会社 | Transparent resin composition |
| WO1992015901A1 (en) * | 1991-03-01 | 1992-09-17 | Mitsubishi Rayon Co., Ltd. | Optical transmitter made of graded index type plastic, and method of producing the same |
-
1983
- 1983-07-02 JP JP58120627A patent/JPS6012509A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6012509A (en) | 1985-01-22 |
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