JPS59228604A - Light conductive body - Google Patents

Abstract

PURPOSE:To improve flexibility and heat resistance as well by forming a core and shell of a plastic clad light conductive body of a specified polymer. CONSTITUTION:The core of a plastic clad light conductive body is formed of a polymer having constitutional unit expressed by the formula ( I ) (X is F or CH3) and the shell is formed of a polymer having the constitutional unit expressed by the formula (II) (Rf is fluoroalkyl group). It is preferred that the polymer for the shell component contains >=10mol% constitutional unit (II) for the improvement of the flexibility of a light conductive body. It is also preferred that each component of the polymer contains >=70mol% constitutional unit I or II respectively for the improvement of the softening temp. to >=100 deg.C or of the stability of transparency or for imparting gasoline resistance to the polymer.

Description

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

Conventionally, a plastic thread photoconductor having a core made of a methyl methacrylate polymer and a sheath made of a fluoroalkyl methacrylate polymer is known (Japanese Patent Publication No. 54-24802). 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 easily eroded by fuel such as gasoline. It also has the problem of being easy to use.

An object of the present invention is to provide a plastic photoconductor that has better flexibility and heat resistance than conventional plastic photoconductors, and is not eroded by gasoline or the like.

The gist of the present invention is to provide a plastic Tallard-type photoconductor in which the core is a polymer having a structural unit represented by the formula: / (wherein, Rf represents a fluoroalkyl group) A photoconductor characterized by being made of a polymer having a structural unit represented by the following formula.

The sheath component polymer of the photoconductor according to the present invention preferably contains t-10 mol% or more of the structural unit represented by formula (b), in order to improve the flexibility of the photoconductor. In addition, each component polymer is preferably of the formula (a) or the formula (a) in order to maintain the transparency of the photoconductor and to make it resistant to gasoline and the like.

RJ included in formula (b) is usually a fluoroalkyl group having 1 to 10 carbon atoms.

The core component polymer having the above-mentioned structural unit (a) is usually acidic diX in the formula, where X is the same as above. ), or polymerize this monomer with ethyl methacrylate, methyl-α-fluoroacrylate other than the monomer represented by formula (C), or an acrylic acid derivative such as methacrylic acid. It can be obtained by copolymerization. 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) is usually produced by polymerizing only the monomer represented by the acid diF/ (in the formula, Rf is the same as above), or by polymerizing this monomer and methyl- It can be obtained by copolymerizing α-fluoroacrylate, methyl methacrylate, and acrylic acid derivatives such as methacrylic acid. Note that it is also possible to 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 employed polymerization methods such as suspension and emulsion polymerization. As the polymerization initiator, azo compounds or organic peroxides are used in bulk, solution and suspension polymerizations, such as azobisisobutyronitrile and isobutyl peroxide. Octanoyl peroxide, di-iso-10 pyruvaroxy dicarbonate, or formula (C1(CF2CFCj)2 CF2c
Fluorine-containing organic peroxides represented by oo)2, (H(CF2CF2)3COO)2, and (CJCF2CF2C00)2 are preferably used. In emulsion polymerization, a redox initiator consisting of an oxidizing agent such as persulfate, a reducing agent such as sodium sulfite, and a transition metal compound such as iron sulfate (2) is used.

In bulk, solution or suspension polymerization, it is preferable to use a chain transfer agent such as mercaptans for the purpose of increasing the thermal decomposition temperature of the polymer and adjusting the molecular distribution. When using a chain transfer agent, the addition ratio of the chain transfer agent is usually 0.00 parts by weight per 100 parts by weight of the monomer. O1~1 coulometric part.

Organic solvents used when producing polymers by solution polymerization include Q'CI2 F2, CCl2 FCCJF
2. Examples of C include hydrocarbon solvents such as gtylacetate, methyl isobutyl ketone, acetonitrile, 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 many cases it is in the range of 10 to 100°C.
A temperature range of 80°C is preferably employed.

The polymerization pressure is in the range of θ to 50 kg/d gauge.

Gel permeation chromatography of the core or sheath polymer prepared by the above polymerization reaction. Column: connected columns of Showdex A-808, A-805, A-806, solvent dimethylformamide, measurement temperature: room temperature, standard The molecular weight measured with polystyrene generally has a distribution of 200,000 to 5,000,000, and the softening temperature measured using a differential scanning calorimeter at a heating rate of 10°C/min is also normal. The refractive index is usually 1.47 to 1.51 for the core component polymer, while it is 1.36 to 1.48 for the sheath component polymer.

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 100 μm, and the thickness of the sheath is 5 to 50 μm.

Next, preparation examples and test examples of photoconductors according to the present invention (Examples 1 to 7) and comparative photoconductors will be shown.

Preparation Examples (Examples 1 to 7 and Comparative Examples) In this case, 0.0.0% of azobisisobutyronitrile was added per 100 parts by weight of monomer.
0 Eft part and 0.5 part by weight of It-dodecylmercaptan were used.

Using each component polymer obtained above, a photoconductor having a core-sheath structure combination shown in Table 1 was prepared.
At 0°C, the polymer of the comparative example starts to thermally decompose at 250°C, so at 220°C, the polymer has a diameter of 300 μm at a speed of 8 m/min.
m (sheath thickness: 15 μm) composite spun into fibers, and then this'! It was prepared by stretching 1°5 times at i-180°C.

Light transmittance and flexibility test The light transmittance was measured after being left for 100 hours. In addition, a flexibility test was conducted by wrapping this sample around steel rods of various diameters to determine the minimum diameter at which the sheath would crack. The results are shown in Table 1.

(The following margins continue on the next page) Table 1 In the table, MMA is methyl methacrylate, EMAi ethyl methacrylate, MFAH methyl-〇-fluoroacrylate, MA is methacrylic acid, PEP [pentafluoropropyl-〇-fluoroacrylate, HFB is 2
．． 2.8.4.4-hexafluorobutyl-〇-fluoroacrylate, TFE is 2.2.2-trifluoroethyl-〇-fluoroacrylate, HFBM is 2.2.
8.4.4.4-hexafluorobutyl methacrylate.

Gasoline Resistance Test The photoconductors prepared in Examples 1 to 7 and Comparative Examples were placed in a constant temperature bath at 80°C filled with saturated gasoline vapor, and after being left for 500 hours, the light transmittance was determined. Example 1
In the cases of Nos. 7 to 7, there was almost no decrease in light transmittance, but in the case of Comparative Examples, the light transmittance was 5%. When the surface of the photoconductor of this comparative example was observed under a microscope, it was found that the surface had minute cracks and the sheath was partially missing.

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

Claims (1)

[Claims] A 1,7" plastic clad photoconductor, the core of which has a structural unit represented by the formula: % (wherein, X represents F or CH3). A photoconductor characterized in that the sheath is made of a polymer having a structural unit represented by the formula: % formula % () (wherein Rf represents a fluoroalkyl group).2. ) The photoconductor according to claim 1, which is a polymer containing 10 mol% or more of the structural unit represented by formula (a). 3. The core contains 70 mol% or more of the structural unit represented by formula (a). 3. The photoconductor according to claim 1, wherein the polymer or sheath is a polymer containing 70 mol% or more of the structural unit represented by formula (b).