JPH0216483B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a plastic optical fiber having good flexibility and improved adhesion between a core and a sheath. Silica glass has traditionally been used as a raw material for optical fibers, but although it has excellent optical performance, it has poor flexibility and is heavy, making it difficult to handle. For this reason, research and development has been carried out on plastic optical fibers that are lightweight and easy to process, with the aim of improving flexibility, and several examples have already been reported. However, since these examples mainly use polystyrene or acrylic resin as the core component and the sheath component, the effect of improving flexibility is not sufficient. There was also a problem in the adhesion between the core and sheath. As a result of extensive research, the present inventors have discovered a plastic optical fiber that has excellent flexibility and improved adhesion between the core and sheath parts, and have completed the present invention. That is, the present invention provides a core made of a homopolymer of 4-methyl-1-pentene or a copolymer of 4-methyl-1-pentene and another olefin (A), and a sheath made of a silicone resin (B). The present invention provides an optical fiber characterized in that: 4-methyl- which is one of the core parts used in the present invention
A copolymer of 1-pentene and another olefin is a copolymer of 4-methyl-1-pentene and 20 mol% or less of another α-olefin, such as an α-olefin having 2 to 20 carbon atoms, preferably 6 to 18 carbon atoms. α-olefins such as 1-hexene, 3-methyl-1
- A copolymer with one or more of pentene, 1-octene, 1-decene, 1-tetradecene, 1-octadecene, etc. As the silicone resin (B) used in the sheath portion of the present invention, any crosslinked silicone resin can be used. Examples of crosslinked silicone resins include organotrialkoxysilanes, tetraalkoxysilanes, organotriasiloxysilanes, vinyltrialkoxysilanes, aminoalkylalkoxysilanes, epoxyalkylalkoxysilanes, silicon-functional polysiloxanes, carbon-functional polysiloxanes, or Examples include those obtained by curing one kind or a mixture of two or more of these partial hydrolysis products or oligomers. Specifically, the organotrialkoxysilane includes methyltrimethoxysilane, ethyltrimethoxysilane, n-butyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, phenyltriethoxysilane, Methyltripropoxysilane, methyltributoxysilane, etc. Tetraalkoxysilanes include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, etc. Organotriacyloxysilanes include methyltriacetoxysilane, ethyltriacetoxysilane , isopropyltriacetoxysilane, phenyltriacetoxysilane, vinyltriacetoxysilane, methyltripropionyloxysilane, ethyltripropionyloxysilane, etc. Vinyltrialkoxysilanes include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, etc. etc., aminoalkylalkoxysilanes include aminomethyltriethoxysilane, N-β-
aminoethylaminomethyltrimethoxysilane,
Examples of epoxyalkylalkoxysilanes include γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, etc.
As the silicon-functional polysiloxane, 1,3-
Dimethoxytetramethyldisiloxane, 1,5-
Dimethoxyhexamethyltrisiloxane, 1,7
-dimethoxyoctamethyltetrasiloxane,
1,9-dimethoxydecamethylpentasiloxane, 1,3-diethoxytetramethyldisiloxane, 1,5-diethoxyhexamethyltrisiloxane, 1,7-diethoxyoctamethyltetrasiloxane, 1,9-diethoxydeca Examples of carbon-functional polysiloxanes such as methylpentasiloxane and 1,3-dimethoxyhexaethyltrisiloxane include 1,3-bis(hydroxymethyl)-1,
Examples include 1,3,3-tetramethyldisiloxane. The optical fiber of the present invention consists of a core made of a homopolymer of 4-methyl-1-pentene or a copolymer of 4-methyl-1-pentene and another olefin (A), and a silicone resin (B). Optical fibers with excellent flexibility can be obtained by directly coating the sheath, but in order to further improve the adhesion between the core and sheath, the core may be treated to form a sheath. . Such treatment methods include, for example, chemical treatment using oxidizing solvents, etc.
Methods include ultraviolet irradiation treatment, corona discharge treatment, plasma treatment, graft treatment using radiation, etc., and methods using adhesives. Among these, a method using an adhesive is preferred, and a method using a rubber-like material grafted with an organosilicon compound having a group having an olefinic unsaturated bond and a hydrolyzable organic group as the adhesive layer is particularly preferred. Rubber-like material grafted with the organosilicon compound
The organosilicon compound grafted onto the rubbery material in (C) may be any organosilicon compound having a group having an olefinic unsaturated bond and a hydrolyzable organic group, and has the general formula R ¹ R ² SiY ¹ Y ² , R ¹ XSiY ¹ Y ² or R ¹ SiY ¹ Y ² Y ³
It is indicated by. In the formula, R ¹ and R ² have an olefinic unsaturated bond, are composed of carbon, hydrogen and optionally oxygen, are the same or different groups, and are reactive with the free radical site generated in the polyolefin. Examples of such groups include vinyl, allyl, butenyl, cyclohexenyl, and cyclopentadienyl, with terminal olefinically unsaturated groups being particularly preferred. Another preferred example has an ester bond of a terminal unsaturated acid. _CH2 =C( _CH3 )COO( _CH2 ) _3- , _CH2 =C( _CH3 )COO( _CH2 ) _2- O-( _CH2 )
₃ −, _CH2 =C( _CH3 ) _{COOCH2OCH2CH2 (} OH _{) CH2O}
Groups such as (CH ₂ ) ₃ − can be mentioned. Among these, vinyl groups are most suitable. X is an organic group having no olefinic unsaturated bond, such as monovalent hydrocarbon groups such as methyl, ethyl, propyl, tetradecyl, octadecyl, phenyl, benzyl, tolyl, etc. , or a halogen-substituted hydrocarbon group. The groups Y ¹ , Y ² , Y ³ are each the same or different hydrolyzable groups, such as alkoxy groups such as methoxy, ethoxy, butoxy, methoxyethoxy, alkoxyalkoxy groups, formyloxy, acetoxy, propionoxy, etc. Acyloxy group, oxime, e.g.
ON=C(CH ₃ ) ₂ , -ON=CHCH ₂ C ₂ H ₅ and -
ON=C( _C6H5 ) ₂ or _substituted amino and arylamino groups, such _{as -NHCH3} , _-NHC2H5 and _-NH ( _C6H5 ), and any other hydrolyzable organic It is the basis. The organosilicon compound preferably used in the present invention is a compound represented by the general formula R ¹ SiY ¹ Y ² Y ³ , in particular the groups Y ¹ , Y ² ,
Organosilicon compounds with equal Y ³ are suitable. Among these, vinyltris alkoxysilane is preferred, and examples include vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltris(methoxyethoxy)silane. However, vinylmethyldiethoxysilane, vinylphenyldimethoxysilane, etc. can be used as well. Basic rubbery substances to which organosilicon compounds are grafted include, for example, polyisoprene, styrene, etc.
Butadiene rubber, polybutadiene, acrylonitrile/butadiene rubber, polychloroprene, butyl rubber, polyether rubber, silicone rubber, acrylic rubber, ethylene/α-olefin (e.g. 3 to 8 carbon atoms) random copolymer, ethylene/α
- Olefin (e.g. 3-8 carbon atoms) diene random copolymer, halogenated polyethylene, ethylene/vinyl acetate copolymer, 4-methyl-1-pentene/α-olefin (e.g. 6-18 carbon atoms) random copolymer Combined, halogenated poly-4-methyl-1
-pentene, halogenated 4-methyl-1-pentene-α-olefin (eg, carbon number 6 to 18) random copolymer, and the like. Among them, ethylene
α-olefin (3 to 8 carbon atoms) random copolymer, ethylene/α-olefin (3 to 8 carbon atoms)
Diene random copolymer, halogenated polyethylene, ethylene/vinyl acetate copolymer, 4-methyl-1-pentene/α-olefin (carbon number 6~
18) Random copolymer, halogenated poly-4-methyl-1-pentene, halogenated 4-methyl-1-
Olefin rubber such as pentene/α-olefin (carbon number 6 to 18) random copolymer is a homopolymer of 4-methyl-1-pentene or 4-methyl-
It is preferred because it is compatible with the copolymer (A) of 1-pentene and other olefins. The grafting amount of the organosilicon compound having a group having an olefinic unsaturated bond and a hydrolyzable organic group to the rubbery material is 0.5 to 50% by weight;
Preferably, the amount is in the range of 5 to 25% by weight. If it is less than 5% by weight, the adhesion between the silicone resin (B) and the rubbery material (C) grafted with an organic silicon compound is poor, and if it is more than 25% by weight, it will cause 4-methyl-1-pentene alone. Polymer or 4-methyl-
Copolymers of 1-pentene and other α-olefins
(A) and a rubbery substance grafted with an organosilicon compound (C)
Adhesion is poor. When producing optical fibers using the above-mentioned 4-methyl-1-pentene homopolymer or copolymer with other olefins (A), organosilicon compound grafted rubbery substance (C), and silicone resin (B) , the sheath material (B) is selected to have a refractive index smaller than that of the core material (A), and (C) is selected to have a refractive index between or equivalent to that of (A) and (B). Select and manufacture products with a certain rate. For example, as a combination (A), 1-hexadene 1
- Octadecene/4-methyl-1-pentene ternary copolymer (refractive index 1.45-1.48), (C) vinyltrimethoxysilane grafted ethylene/propylene random copolymer (refractive index 1.44-1.47), (B) Examples include a mixture of partial hydrolysis products of methyltrimethoxysilane and 1,3-dimethoxytetramethyldisiloxane (refractive index 1.40 to 1.43). A method for producing optical fibers using these combinations is, for example, by melt-spinning a homopolymer of 4-methyl-1-pentene or a copolymer of 4-methyl-1-pentene and another olefin (A). Directly immersed in a melt of the organosilicon compound grafted rubbery substance (C) or a diluted solution of the grafted material in a solvent, then immersed in a melted solution of the silicone resin (B) or a diluted silicone resin in a solvent, and then heated. An example of how to perform the processing can be given. The solvent used to dilute the grafted rubbery substance (C) is one that dissolves the grafted rubbery substance and is a 4-methyl-1-pentene homopolymer or a 4-methyl-1-pentene homopolymer.
A solvent that does not devitrify the copolymer (A) of -methyl-1-pentene and other olefins is preferred. Examples of such solvents include aromatic hydrocarbon solvents such as benzene, toluene, and xylene, n-hexane,
Examples include aliphatic hydrocarbon solvents such as cyclohexane and n-heptane, and chlorine solvents such as carbon tetrachloride, 1,1,1-trichloroethane, 1-chlorobutane, and trichloroethylene. Solvents used to dilute the silicone resin (B) include alcohols such as ethyl alcohol, propyl alcohol, butyl alcohol, and amyl alcohol; ethers such as propyl ether, butyl ether, ethylene glycol monoethyl ether, and ethylene glycol monomethyl ether; Ketones such as methyl ethyl ketone and diethyl ketone,
One or a mixture of two or more of esters such as ethyl acetate, propyl acetate, butyl acetate, and ethyl propionate, and aromatic hydrocarbons such as benzene, toluene, and p-xylene are used. The optical fiber of the present invention is lightweight and has good processability, and is more flexible than other plastic optical fibers, has a hard surface, has excellent scratch resistance, and is made of a rubber-like material grafted with an organic silicon compound. The optical fiber with a sheath formed through it has excellent adhesion and can be used for, for example, indoor lighting, art lighting, automobile lighting, plant cultivation, and various information transmission. Examples are shown below. Example 1 3 consisting of 4-methyl-1-pentene, 3% by weight of 1-hexadecene, and 3% by weight of 1-octadecene
The original copolymer was melt-spun at 290°C, then heat-treated at 90°C for 3 minutes, and immersed in a 2% by weight surfactant solution heated to 50°C for 30 seconds. After soaking, dry with hot air and add 100ml of 1,1,1-trichloroethane.
and 1 g of vinyltrimethoxysilane grafted ethylene propylene random copolymer dissolved therein at 20° C. for 30 seconds. After dipping, it was dried again with hot air, and then a mixture of partial hydrolysis products of methyltrimethoxysilane and 1,3-dimethoxytetramethyldisiloxane was added.
25% by weight of isopropyl alcohol/methanol solution (Shin-Etsu Chemical X-12-940) at 20°C.
Soak for 10 seconds, dry with hot air, and then put in an air oven.
Heat treatment was performed at 80°C for 120 minutes. The optical fiber thus produced was evaluated for toughness and flexibility by the following method, and the results shown in Table 1 were obtained.・The various core materials shown in Table 1 with a diameter of 1 mm are
It was wound around a cylinder having an R interval, and the R at which the core material broke was evaluated (Samples 1 to 3). As a result, the optical fiber of the present invention obtained from 4-methyl-1-pentene polymer (TPX) has a smaller bend radius than optical fibers obtained from polystyrene or polymethyl methacrylate (PMMA). , it can be seen that it has excellent toughness and flexibility.・In contrast to TPX that was primed with an ethylene-propylene random copolymer grafted with 18% vinyltrimethoxysilane and whose sheath was coated with silicone, the sheath peeled off only after bending to R = 35 mm (sample 4). When no primer was used, the sheath peeled off at R = 80 mm (Sample 5).

【table】

[Table] The core refractive index of the optical fiber of the present invention is
The refractive index of the sheath was 1.26-1.27.

Claims (1)

[Claims] 1 A core made of a homopolymer of 4-methyl-1-pentene or a copolymer of 4-methyl-1-pentene and another olefin (A) and a silicone resin (B). An optical fiber characterized by having a sheath formed therein. 2 A rubber-like substance in which the sheath made of silicone resin (B) is grafted with an organosilicon compound having a group having an olefinic unsaturated bond and a hydrolyzable organic group.
(C) The optical fiber according to claim 1, wherein the optical fiber is formed through a layer.