JPS61114211A - Plastic optical fiber - Google Patents

Abstract

PURPOSE:To improve the optical transmission characteristic from a visible light region to near IR region by using a polymer obtainable from the monomer alpha,beta,beta-heavy hydrogen-2,3,4,5,6-pentafluorostyrene expressed by the specific constitutional formula as a core component resin. CONSTITUTION:The core component resin to be used is the polymer obtainable from the monomer of the alpha,beta,beta-heavy hydrogen-2,3,4,5,6-pentafluorostyrene expressed by the formula. The core component resin may be the copolymer with the vinyl monomer which can be copolymerized with the monomer expressed by the formula and the compounding ratio thereof is preferably about <=50wt%, more preferably <=25wt% and most preferably <=10wt%. The vinyl monomer of which the C-H bond is made of heavy hydrogen or is fluorinated is most preferably used in terms of the optical transmission characteristic. The core component resin is preferably polymerized by bulk polymn.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a plastic optical fiber having a core and sheath structure using a polymer obtained from a monomer having a specific deuterium fluorinated structural formula. The present invention relates to a plastic optical fiber that has excellent light transmission properties over the visible light region to near-infrared light region when used as a core component resin.

(Conventional technology and problems) Plastic optical fibers are made of burnt glass,
In particular, compared to quartz glass fiber, it has excellent flexibility even when made to a large diameter, and it is easy to obtain a lightweight and high numerical aperture, which reduces connection loss with the light source and allows for industrial mass production. Therefore, it has the characteristic of being extremely inexpensive, and is used in short-distance transmission systems.

Polymethyl methacrylate, polystyrene, polycarbonate, etc., which have good transparency, are generally used as core component resins for plastic optical fibers, but they have the disadvantage of inferior light transmission properties compared to quartz glass fibers. In addition, LEDs and T
, D have emission wavelengths in the vicinity of 660 to 900 nm, and from this point of view as well, there is a desire to develop plastic optical fibers with excellent optical transmission properties over the visible light region to the near-infrared light region.

(Means and Effects for Solving the Problems) The present inventors have made extensive efforts to improve the above-mentioned drawbacks, and as a result, the present inventors have found a specific deuterated and fluorinated structural formula as in the present invention. By using a polymer obtained from a monomer having as a core component resin, we have developed a plastic optical fiber with dramatically improved optical transmission properties from the visible light region to the near-infrared light region, and completed the present invention. .

That is, the present invention provides a plastic optical fiber having a core and sheath structure, which is a polymer obtained from monomers α, β, β-heavy water-2,3,4,5,6-pentafluorostyrene having the following structural formula. This is a plastic optical fiber characterized by using the following as a core component resin.

According to the studies of the present inventors, synthetic polymers generally have O-H bonds in their molecular structures, and harmonics of their infrared absorption are one of the major factors that reduce optical transmission properties. be. In particular, light transmission properties in the near-infrared region of 600 to 900 nm, which is the emission wavelength of inexpensive and high emission intensity LEDs and LDs, are greatly reduced.

In addition, the wavelength position of peaks and troughs of absorption intensity of harmonics of this infrared absorption fluctuates due to differences in molecular structure, forming a so-called loss window with excellent optical transmission properties at a specific wavelength.

The present inventors have completed the present invention by applying the above-described phenomenon industrially. In other words, the infrared absorption of the O-H bond is shifted to a longer wavelength region by freezing and fluorinating the O-H bond in the molecular structure, and the infrared absorption of the O-H bond is shifted to a longer wavelength region. By hydrogenating and fluorinating, it has become possible to adjust the wavelength position of the so-called loss window to match the emission wavelength of the light emitting device in the visible light region to near-infrared region, and improve optical transmission properties. .

The core component resin used in the present invention is a polymer obtained from a, β, β-deuterium-2,3,4,5,6-pentafluorostyrene monomer having the structural formula shown below. .

The above monomers are 1. y, ohem, 8oc,, 1
66 (1959).

J, ues, NaL/, Bur std, 67A
481 (1968).

Bull, Chem, 8oc, Japan, 8
4, 560 (1961) IJ, AI) pI, ph
ys, 82.2820 (1961).

The core component resin used in the present invention may be a copolymer of the monomer represented by the above structural formula and a copolymerizable vinyl monomer, and the blending ratio thereof is preferably 5 Qwt% or less, and 2
It is more preferably 5 wt% or less, most preferably 10 wt% or less. From the viewpoint of excellent optical transmission properties, it is most preferable to use a vinyl monomer in which the C--bond is deuterated or fluorinated.

The core component resin used in the present invention is preferably polymerized by bulk polymerization from the viewpoint of optical transmission properties.

After removing impurities from the monomer used in the present invention using a distillation device with a high rectification effect, or performing appropriate pretreatment,
It is further distilled to obtain a highly pure monomer free of dust, transition metals, coloring impurities, etc.

The polymerization initiator used in the present invention may be arbitrarily selected depending on the desired polymerization rate, polymerization temperature, and polymerization rate, such as azobisisobutyronitrile, 1,1-azobis(cyclohexane-1- carbonitrile), benzoyl peroxide, t-butyl peroxide, etc. There is no particular limitation on the amount used, and it may be used within a range that allows appropriate polymerization control.

Any molecular chain regulator used in the present invention may be selected as long as it does not have an adverse effect such as coloring on the final polymer, such as n-butyl mercaptan, t-butyl mercaptan, n-dodecyl mercaptan, Examples include t-dodecyl mercaptan. There is no particular limit to the amount used.

The weight average molecular weight of the final polymer is 80,000 to 150
．． It is preferable to use it in a range of 000.

As for the method of charging the polymerization initiator and molecular flow regulator used in the present invention, since the amount used is small, it is preferable to dissolve it in a small amount of monomer under environmental conditions that prevent contamination such as dust, and then charge it to the polymerization machine. . In order to avoid unexpected contamination with dust, distillable polymerization initiators such as t-butyl peroxide and n-octyl azobutane are used, and distillable molecules such as n-butyl mercaptan and t-alfRJ agents are used. If butyl mercaptan or the like is used, it becomes possible to employ a distillation preparation method. It is also possible to dissolve a polymerization initiator and a molecular BR regulator in a small amount of monomer, and then pass the mixture through a filter and charge it into a polymerization machine.

In order to remove dust from entering the polymer, the above-mentioned method is sufficient for making the monomer, polymerization initiator, and molecule IT adhesive agent sheath, but it is necessary to prevent dust from entering the polymer. From this point of view, it is more important than anything else to thoroughly remove dust inside the polymerization machine that manufactures polymers.
As a method for this, the present inventors previously filed a patent application filed in 1982-
It is preferable to remove as much dust as possible from inside the polymerization machine before polymerization by employing the methods described in Japanese Patent Application No. 42761, Japanese Patent Application No. 58-42762, and the like.

The sheath component resin used in the present invention is not particularly limited as long as it has a lower refractive index than the core component resin shown in the present invention and relatively excellent transparency, and has a desired numerical aperture. , any one may be selected depending on the spinnability.

Examples of such sheath component resins include fluorine-containing polymers. Specific examples include homopolymers or copolymers of tetrafluoroethylene, vinylidene fluoride, hexafluoropropylene, etc., homopolymers of fluorinated alcohol esters of methacrylic acid, or methacrylic acid esters of these and methyl methacrylate, etc. Acrylic esters such as methyl acrylate, acrylic acid,
Examples include copolymers with methacrylic acid and the like.

Among these fluorine-containing polymers, a copolymer of tetrafluoroethylene and vinylidene fluoride is preferred from the viewpoint of price, production method, spinnability, heat resistance, etc., and it can also be copolymerized with these monomers as an eighth component. A copolymer obtained by adding and copolymerizing a monomer is also preferable. On the other hand, from the viewpoint of optical transmission, among the fluorine-containing polymers, the homopolymer of the fluorinated alcohol ester of methacrylic acid is preferable, and the homopolymer of the fluorinated alcohol ester of methacrylic acid and methyl methacrylate is preferable. More preferably, a copolymer with IH, IH, 5H-octafluoropentyl methacrylate and methyl methacrylate,
Copolymer of IH, IH, 2H, 2H-heptadecafluorodecyl methacrylate and methyl methacrylate, 2
, 2,3,8,8-pentafluoropropyl methacrylate and methyl methacrylate are particularly preferred. Also preferred is a copolymer obtained by copolymerizing a fluorinated alcohol ester of methacrylic acid and an eighth monomer copolymerizable with methyl methacrylate.

The plastic optical fiber of the present invention is produced from the core component resin and sheath component resin produced as described above. The manufacturing method is particularly suitable if it is a commonly used method such as a method of spinning a core component resin and then coating the sheath component resin thereon, or a method of composite melt spinning of the core component resin and the sheath component resin. It can be adopted without any restrictions.

The plastic optical fiber obtained in this manner has a core and sheath structure with a sheath layer having a thickness of 5 to 20 μm, and preferably has a diameter of 0.8 to 8su+ from the viewpoint of connection with the fiber and connection with a light source. ,0.
It is more preferable to have a weight of 5 to 2, and particularly preferable to be 0.8 to 1.2.

The plastic optical fiber obtained as described above uses a polymer obtained from a monomer having a specific fluorinated structural formula shown in the present invention as a core component resin, so it is different from the conventional one. Optical transmission properties are dramatically improved compared to plastic optical fibers,
The possible transmission range is expanded, and the range of applications such as in-building communication can be dramatically expanded.

(Example) The optical fiber of the present invention will be described below based on Examples. The optical transmission properties are determined by using a halogen lamp as the light source and measuring the length L) of the incident intensity [1 (Io) and output intensity (Io) of this plastic optical fiber.
) was evaluated using the transmission loss calculated by the following formula.

Transmission loss (dn/xm) = -101! og(1/I
o)/L・Example 1 100 parts of α,β,β-deuterated-2.3,4,5.6-pentafluorostyrene, 0.0085 parts of azobis-tert-octane, 0.1 part of lauryl mercaptan The monomer polymer was supplied to a glass-lined polymerization machine, and continuous bulk polymerization was carried out at a polymerization temperature of 180° C. and an average residence time of 6 hours.

The obtained polymer solution of approximately 5096 was fed to a multi-stage vent extruder, unpolymerized single caps were removed, and then introduced to a composite melting device where tetrafluoroethylene was added as a sheath component resin.
A plastic optical fiber having a core and sheath structure with a diameter of 1 dragon was obtained by composite melt spinning using a vinylidene fluoride copolymer. Transmission loss is 660 parts m 1
05dB/Km.

780 parts m 210 dB/Km, 850 parts m 81
At 0 dB/Km, it exhibited excellent optical transmission properties in the visible light range to near-infrared light range.

Examples 2 to B Plastic optical fibers were obtained using the same core component resin, polymerization method, demonomer removal, and composite melt spinning as in Example 1, but changing the sheath component resin. The transmission loss of the obtained plastic optical fiber is shown in the table below.

MMA...Methyl methacrylate 8FM...III, IH, 51-octafluoropentyl methacrylate 5FM...2,2,3,8.8-pentafluoropropyl methacrylate Example 4 a, β, β-deuterium -60 parts of 2.3,4,5.6-bentafluorostyrene, 40 parts of 2,3,4,5.6-deuterated styrene, 0.0 parts of azobis-tert-octane
A monomer mixture containing 85 parts of lauryl mercaptan and 0.1 part of lauryl mercaptan was polymerized in the same manner as in Example 1, and the hair removal Zimmer 1 complex was melt-spun to obtain a fiber with a diameter of 1 ym. The transmission loss is
660 parts m 125dB/Km, 780 parts m250d
B/Km, 850 parts m, 810 dB/Km, and showed excellent optical transmission properties in the visible light region to near-infrared light region.

Claims (1)

[Claims] (1) In plastic optical fibers having a core and sheath structure, monomers α, β, β of the following structural formula are used.
- A plastic optical fiber characterized in that a polymer obtained from deuterium-2,3,4,5,6 pentafluorostyrene is used as a core component resin. ▲Contains mathematical formulas, chemical formulas, tables, etc.▼