JPS60118808A - Optical transmission body - Google Patents

Abstract

PURPOSE:To obtain an optical transmission body having high softening temp. and good flexibility by using a polymer having methyl-alpha-fluoracrylate and methyl methacrylate as a polymer unit for the core thereof and a polymer contg. fluoroalkyl-alpha-fluoroacrylate as a polymer unit for the cladding. CONSTITUTION:An optical transmission body is manufactured by using a polymer contg. preferably >=70mol% the structural unit expressed by the formula I (X is F or CH3) as a core and a polymer contg. >=10mol% the structural unit expressed by the formula II (Rf is fluoroalkyl) as a cladding. The optical transmission body of which the core has 1.47-1.51 refractive index and the cladding 1.36-1.43 and which has good flexibility, high softening point and excellent gasoline resistance is obtd.

Description

[Detailed description of the invention] The present invention relates to plastic-based photoconductors.

Conventionally, plastic photoconductors with a core of methyl methacrylate polymer and a fluoroalkyl methacrylate polymer tJIQ have been known (Japanese Patent Publication No. 54-2430).
Publication No. 2). However, this photoconductor has problems with its flexibility, and its light transmittance decreases significantly if it is exposed to high temperatures for a long period of time.Furthermore, when it is installed in a vehicle, it is eroded by fuels such as gasoline. It also has the problem of being easily exposed.

'The object of the present invention is to provide a plastic optical conductor which has better flexibility and heat resistance than conventional single plastic optical conductors, and which is not eroded by K gasoline or the like. .

The gist of the present invention is to provide a plastic thread clad photoconductor in which the core has the formula: X/-CH2-C-\C0(X;H.

(In the formula, X represents F or CH3.) The union, sheath has a structural unit represented by the formula: % Formula % (In the formula, Rf represents a fluoroalkyl group.) A photoconductor characterized by being made of a polymer.

The sheath component polymer of the photoconductor according to the present invention preferably contains 10 mol% or more of the structural unit represented by formula (b) in order to improve the flexibility of the photoconductor. Containing 0 mol% or more of rough structural units represented by formula (a) or formula (b) in the combination of the components improves the softening temperature of the photoconductor to 100°C or higher and improves the transparency of the photoconductor. This is preferable in terms of maintaining the temperature and resistance to gasoline and the like.

The core component blood complex having the above structural unit (a) is usually produced by polymerizing only the 1#mer represented by /CH2=C\0OCH3 (wherein, X is the same as above), or by polymerizing this monomer. and an acrylic acid derivative such as ethyl methacrylate, methyl-a-fluoroacrylate, or methacrylic acid. In addition, it is also possible to further copolymerize other ethylenically unsaturated compounds as comonomers.

The sheath component polymer having the above structural unit (b) usually polymerizes only the monomer represented by the following formula (wherein, R7 is the same as above). It can be obtained by copolymerizing a mushroom monomer with an acrylic acid derivative such as methyl-α-fluoroacrylate, methyl methacrylate, or methacrylic acid. In addition, it is also possible to further copolymerize other ethylenically unsaturated compounds as comonomers.

The above-mentioned core or sheath component polymers may be in the form of lumps, solutions,
It can be produced by polymerization using commonly used polymerization methods such as suspension and emulsion polymerization. As polymerization initiators, azo thread compounds or organic peroxides are used in bulk, solution and suspension polymerizations, such as azobisisobutyronitrile, isobutyryl peroxide, octanoyl peroxide, G-Isorb IU bilber oxide, etc. Sheen-carbonate, or formula (CI (CF2 CFC71)
2C:F2Coo)2, (H(CF2CF2)
3 Coo)2 and (CJ CF2 CF2 COO
) A fluorine-containing organic peroxide represented by 2 is preferably used. In emulsion polymerization, persulfates such as ammonium persulfate, potassium persulfate or oxidizing agents such as these persulfates, reducing agents such as sodium sulfite, and redox initiators such as salts of transition metals such as iron sulfate are used. It will be done.

In bulk, solution or suspension polymerization, it is preferable to use a chain transfer agent such as mercaptans for the purpose of (1) increasing the thermal decomposition temperature of the polymer and adjusting the molecular weight distribution. When a chain transfer agent is used, the addition ratio of the chain transfer agent is usually 0.01 to 1 part by weight per 100 parts by weight of the small polymer.

Examples of hydrocarbon solvents used in the production of solution J1f include (2), methyl isobutyl ketone, a7tonitrile, acetone, and dimethylformamide.

The polymerization temperature is usually in the range of 0 to 100°C, and is determined in relation to the decomposition temperature of the polymerization initiator, but in most cases it is in the range of 10 to 8°C.
A range of 0°C is preferably adopted.

The combined pressure is in the range of 0 to 50 kg/d gauge, and the molecular weight measured by gel permeation of the core or sheath component polymer prepared by the above polymerization reaction is usually 200,000 to 200,000.
5 million, and the softening temperature is usually 100 to 150°C, but the refractive index of the core component polymer is usually 1.47 to 1.5.
1, whereas the sheath component polymer has l, 36 to 1.43
It is.

The photoconductor according to the present invention is usually produced by separately heating and melting the core or sheath component polymers, and then subjecting them to composite spinning.

The diameter of this photoconductor is usually 100 to 500 μm, and the thickness of the sheath is about 5 to 50 μm.

Next, a test example of the preparation of photoconductors (Examples 1 to 7) made in an unknown manner and four comparative examples with a wide tip will be shown.

Preparation Examples (Examples 1 to 72 and Comparative Examples) Each monomer shown in Table 1 was subjected to bulk polymerization at 50°C for 3 hours to prepare a core or sheath component polymer.

In this case, 1 part by weight of azobisisobutyronitrile and 0.5 part by weight of 11-dodecylmercaptan were used per part by weight of monomer 1.

Using the respective component polymers obtained above, a photoconductor of 300 μm in diameter, 15 μm in sheath depth, and 500 μm in length was prepared using the combinations shown in Table 1. The photoconductor according to the present invention was heated at 250°C.
The polymer of the comparative example starts to thermally decompose at 250°C, so 22
The composite was spun at 0°C at a speed of 8 yiz/min and then stretched 1.5 times at 180°C.

Light Transmittance and Flexibility Test The light transmittance of the sample prepared above was measured using light of 650 to 680 nm immediately after spinning and after being left in an atmosphere at 100° C. for 100 hours. In addition, this sample was wrapped around steel rods of various diameters, and an iJ bendability test was carried out to minimize the chance of the rod entering the sheath. The results are shown in Table 1.

(Public figure meeting, [missing] this) Table 1. In the table, MMA is methyl methacrylate, EMA is ethyl methacrylate, MFAff methyl-〇-fluoroacrylate, MA is methacrylic acid, p lr p n
pentafluoropropyl-α-fluoroacrylate,
11 FB is 2.2.8.4.4-hexafluorobutyl-a-fluoroacrylate, TFEI-J, 2
．． 2.2-1-Lifluoroethyl-α-fluoroacrylate, FBM indicates 2.2.8.4.4.4-hexaful blade'J goutyl methacrylate.

Gasoline resistance test
1j11 The photoconductors prepared in Examples 1 to 7 and Comparative Examples were added, and the light transmittance was measured after standing for 500 hours).
Examples 1 to 7 have almost no fc of low light transmission +
I had a hard time. The surface t of the wide tip 2jJ and I4- of this comparative example
i11' + #M detected with a mirror (by the way, l-1' on the surface
It contained a kaiko kratsuku, and the scabbard was partially missing.

that's all Patent applicant: Daikin Industries, Ltd.

Claims (1)

[Claims] 15 In a plus-natch yarn clad type photoconductor, the core is a polymer having a structural unit represented by the formula: % formula % (in the formula, X represents F and CH3); A photoconductor characterized in that the sheath is made of a polymer having a collapsible unit represented by the formula: %(%) (wherein Rf represents a fluoroalkyl group). 2. The photoconductor according to claim 1, wherein the sheath is a polymer containing 10 mol% or more of the structural unit represented by formula (b). 8. Structural unit fc whose core is represented by formula (a) 70 mol%
3. The photoconductor according to claim 1, wherein the polymer sheath contains 70 mol% or more of vortex units represented by formula (b).