JP2805977B2 - Method for producing light transmitting fiber - Google Patents

Description

The present invention relates to a method for producing an optical transmission fiber, and more specifically, to a plastic optical transmission fiber having excellent adhesion between a sheath portion and a core portion. The present invention relates to a method for producing a light-transmitting fiber that can easily and reliably obtain a fiber.

[Problems to be solved by conventional technology and invention]

As is well known, the optical transmitting fiber includes a plastic optical transmitting fiber in which both the core material and the sheath material are formed of plastic, in addition to the glass-based fiber using quartz glass or multi-component glass as the core material and the sheath material. is there. Although this plastic optical transmission fiber has inferior transmission characteristics compared to glass-based fibers, it has features such as easy handling and low cost, and forms one field for short-distance communication. ing.

Conventionally, as a plastic material used for this plastic light transmitting fiber, a methyl methacrylate polymer or a copolymer thereof, a fluorine-modified product, polystyrene, polyorganosiloxane, or the like is used as a core material, and a sheath material is used as a sheath material. Uses polytetrafluoroethylene or a copolymer thereof. When a photoconductive fiber is produced using these materials, for example, polytetrafluoroethylene is used for a sheath material, a tube is produced therefrom, and then this tube is filled with an acrylate monomer, and the inside of the tube is produced. Polymerization is performed to form a polyacrylate core material, and a fiber is obtained in which a sheath material made of polytetrafluoroethylene and a core material made of polyacrylate are integrated.

However, such a method has a disadvantage that the material of the sheath and the core is different, and thus the separation easily occurs at the interface between the sheath and the core, thereby increasing the transmission loss.

The present invention has been made in view of the above circumstances, and has an excellent adhesion between a sheath portion and a core portion, and a method for producing an optical transmission fiber that can easily obtain a plastic optical transmission fiber having good transmission characteristics. The purpose is to provide.

[Means and actions for solving the problem]

The present inventor has conducted intensive studies to achieve the above object, and as a result, a general formula was used as a core material. (Wherein, R is a monovalent organic group, and a is a positive number from 1.1 to 2), which is melted and spun to obtain a polysilane fiber. The core (polysilane fiber) is coated with a mixture of the same or different polysilane and a peroxide, and the mixture is heated to decompose the peroxide and convert the polysilane to polysiloxane to form a sheath. By forming the portion, it has been found that excellent adhesion between the core portion and the sheath portion, and that a plastic light transmitting fiber having good light transmission characteristics can be easily and reliably obtained, and the present invention has been completed. Things.

Accordingly, the present invention provides a compound of the general formula (Wherein, R is a monovalent organic group, and a is a positive number from 1.1 to 2). After melting and spinning, a peroxide is added to the outside of the polysilane of the same type or different from the above polysilane. Coating a layer of the added polysilane mixture,
An object of the present invention is to provide a method for producing a light-transmitting fiber, which is subjected to a heat treatment.

 Hereinafter, the present invention will be described in more detail.

The core material used in the method for producing a light transmitting fiber of the present invention has a general formula (Wherein, R is a monovalent organic group, and a is a positive number of 1.1 to 2). That is, this polysilane is composed of structural units R ¹ Si, R ¹ R ² Si, R ¹ R ² R ³ Si (R ¹ , R ² , and R ³ represent the same or different monovalent organic groups). In the general formula, R corresponds to R ¹ , R ² , and R ³ . Where R ¹ , R ² , R ³
Each preferably has 1 to 16 carbon atoms, particularly preferably 1 to 10 carbon atoms. For example, methyl, ethyl, propyl, n
Alkyl groups such as hexyl group, vinyl group, allyl group,
Alkenyl groups such as hexenyl groups, cyclohexyl groups,
Cycloalkyl group such as cycloheptyl group, aryl group such as phenyl group, tolyl group, xylyl group, aralkyl group such as benzyl group and phenylethyl group, halogen-substituted monovalent carbon such as chlorophenyl group, tetrachlorophenyl group, chloromethyl group and the like. A hydrogen group is exemplified. This R ¹ , R
² , R ³ may be the same or different, but in particular, a combination of a methyl group and a phenyl group, a combination of phenyl groups, a combination of a methyl group and an n-hexyl group,
A combination of n-hexyl groups is preferred. The polysilane preferably has a molecular weight of 1,000 to 1,000,000.

The sheath used in the method of the present invention is a mixture of polysilane and peroxide. In this case, it is preferable to use the same kind of polysilane as the above-mentioned core material polysilane, but it is also possible to use different kinds of polysilane. In this case, the polysilane is converted into polysiloxane by the action of a peroxide in the subsequent heating step, so it is necessary to select the polysilane of the sheath material so that the refractive index is lower than that of the polysilane of the core material. In addition, as the peroxide, a general-purpose peroxide such as benzoic peroxide, dicumyl peroxide, di-t-butylbenzoic peroxide, and 2,4-dichlorobenzoic peroxide can be used. In this case, a peroxide having a very low decomposition temperature is difficult to use in terms of operation, and thus dicumyl peroxide or the like is preferable. The amount of peroxide used is preferably 1 mole of peroxide to 1 mole of Si,
It may be less than this, and is preferably in the range of 1 to 0.1 mol per mol of Si.

In the method for producing the light transmitting fiber of the present invention, first, the polysilane of the core material is melted and spun to produce a polysilane fiber.As a specific spinning method, the polysilane in a molten state is formed by pores such as an orifice. And the like.

Next, this polysilane fiber is coated with a mixture of the above-mentioned sheath material polysilane and peroxide. The method for coating the mixture is not particularly limited, but the mixture is dissolved in a volatile solvent such as tetrahydrofuran, benzene, toluene, and the like, and polysilane fibers are passed through the solution to form an outer periphery of the fiber. A method in which the mixture solution layer is formed on the entire surface and the solvent is volatilized and removed can be suitably adopted. When using polysilane having a low melting point,
It is possible to work in a molten state without dissolving in a solvent, but it is preferable to select this appropriately according to the type of peroxide to be combined.

The production method of the present invention is to obtain a light transmitting fiber by heating the polysilane fiber covered with the sheath material. In this case, the heating temperature is equal to or higher than the decomposition temperature of the peroxide of the sheath material and equal to or lower than the melting temperature of the polysilane, and can be appropriately set according to the sheath material and the core material used.

The diameter of the light transmitting fiber can be adjusted to a desired diameter by appropriately adjusting the melt viscosity of the polysilane as the core material, the diameter of the orifice, the concentration of the sheath material solution, and the like.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to the manufacturing method of the optical transmission fiber of this invention, it is excellent in the adhesiveness of a sheath part and a core part, and can obtain easily and reliably the plastic optical transmission fiber with favorable optical transmission characteristics.

Hereinafter, the present invention will be described in detail with reference to Examples,
The present invention is not limited to the following examples.

[Example 1] Methylphenylpolysilane having a molecular weight of about 100,000 was heated to about 200 ° C.
Heated and melted, extruded from the orifice,
A 1 mm polysilane fiber was obtained. On the other hand, 20 g of dicumyl peroxide was added to 100 g of methylphenylpolysilane as described above, and this mixture was dissolved in tetrahydrofuran to prepare a 15% solution of this mixture. After passing the polysilane fiber through this solution to form a coating layer, the solvent was evaporated at room temperature and heated at 150 ° C. for 24 hours to obtain a light transmitting fiber.

The light transmission loss of this light transmitting fiber was 2 db / m at 660 nm light. In addition, the interface between the inner layer and the outer layer is
There was no protrusion of the inner layer even after heating at 0 ° C. for 48 hours.

[Example 2] Di-n-hexylpolysilane having a molecular weight of about 50,000 was heated to about 190 ° C.
Heated and melted, extruded from the orifice,
A 1 mm polysilane fiber was obtained. On the other hand, the same di-n
-15 g of benzoic peroxide was added to 100 g of hexylpolysilane, and this mixture was dissolved in toluene to prepare a 15% solution of this mixture. After passing the polysilane fiber through this solution to form a coating layer, the solvent was volatilized at room temperature and heated at 100 ° C. for 24 hours to obtain a light transmitting fiber.

The light transmission loss of this light transmitting fiber is 2.4db / m at 660nm light.
Met. The interface between the inner and outer layers is integrated,
After 48 hours of heating, there was no protrusion of the inner layer.

From Examples 1 and 2 above, it was confirmed that the light transmitting fiber produced by the production method of the present invention had excellent adhesion between the sheath and the core, and had good light transmitting characteristics.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Motoo Fukushima 100-1 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa Shin-Etsu Chemical Co., Ltd. Corporate Research Center (72) Inventor Eiichi Tabei 100 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa ―1 Shin-Etsu Chemical Co., Ltd. Corporate Research Center

Claims (1)

(57) [Claims] (1) General formula (Wherein, R is a monovalent organic group, and a is a positive number from 1.1 to 2). After melting and spinning, a peroxide is added to the outside of the polysilane of the same type or different from the above polysilane. Coating a layer of the added polysilane mixture,
A method for producing a light transmitting fiber, comprising subjecting the fiber to a heat treatment.