JPS587602A - Light transmitting fiber - Google Patents

Abstract

PURPOSE:To improve the adhesive strenght of the core material to the sheath material and to enhance the light transmitting performance by covering a methyl methacrylate polymer as the core material with a specified fluoroalkyl methacrylate polymer as the sheath material. CONSTITUTION:A rod 22 of a methyl methacrylate polymer contg. >=90mol% methyl methacrylate units is attached to a chuck 14 for attaching a rod, and it is extruded from a rod tip heating part 15 to a cooling part 16 under conditions which do not cause the orientation of a fiber, forming a core material. This core material is coated with a soln. 17 of a fluoroalkyl methacrylate (co)polymer expressed by the formula (where X is a random bond chain consisting of tetrafluoroethylene T and vinylidene fluoride V, the total of T and V is 2-4, the ratio of T/V is 1/5-5, and n=1-2), and the coated material is dried with a drying tower 17 and coiled around a coiling roller 20 through nip rollers 19.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a metal resin optical transmission fiber trap having a core-sheath structure.

Conventionally, inorganic glass-based optical fibers are known as optical transmission fibers that have excellent optical transmission properties over a wide range of 1 IkK, but they are not only difficult to process and suffer from stress, but are also expensive. For this reason, optical transmission fibers based on synthetic resin have been developed. As for the transmission fiber in the synthetic column Mm, it is known that polystyrene is used as the core material and methyl methacrylate polymer is used as the core material, but methyl methacrylate polymer is preferred because of its superior optical transmission performance. The one used is commonly used.

Examples of sheath materials for optical transmission fibers using methyl methacrylate polymers as core materials include Japanese Patent Publication No. 4s-8978, Japanese Patent Publication No. 54-8B21, Japanese Patent Publication No. 1% 854-8122, *
Plan number 864-8525, and % open ws55-60245
Copolymers of vinylidene fluoride and tetrafluoroethylene as described in Japanese Patent Publication No. 55-42240, which are made by adding heavy metals to esters consisting of methacrylic acid and fluorinated alcohols, as described in Japanese Patent Publication No. 55-42240 Those consisting of coalescence are known.

1. The optical transmission performance of a transmission fiber is closely related to the concentration and dispersion of the core and sheath materials, and the reflection center at the core-sheath interface.

The polymer mainly composed of esters made of methacrylic acid and 7-bulky alcohols, which is used as a sheath material by Juuki, has extremely low absorption and scattering, so optical transmission loss due to such factors is small. Although the amount is small, the adhesion with the methyl meterylate polymer, which is the core material, is poor, and the core
The disadvantage of the screen-like image is that it has a large transmission loss. On the other hand, the copolymer of vinylidene fluoride and tetrafluoroethylene described in Japanese Patent Publication No. 5B-42240 has extremely good adhesion with polymethacrylate polymer, but has crystallinity. Therefore, there is a drawback that transmission loss due to dispersion is large.

As a result of intensive study to improve the optical transmission loss of optical transmission fibers using such a methyl methacrylate polymer as a core material, the present inventors developed the following general formula (where X is tetrafluoroethylene): and vinylidene fluoride (a), and the total number of eP) and (b) forming X is 2 to 6, and the ratio (1)/(a) of both is 115 to 5, and n is 1 or 2) By using a polymer mainly composed of esters of fluorinated alcohols and methacrylic acid as the sheath material, S# methyl methacrylate We discovered that the adhesion with the system polymer was improved and that the china clay had good light transmission performance.

That is, the gist of the present invention is that the monomer mole S(
A methyl methacrylate polymer containing at least 4 to mole of methyl methacrylate units is used as a core material, and the general formula (wherein X is composed of random bonds of tetrafluoroethylene (a) and vinylidene fluoride (b), A chain in which the total number of constituents (to) and (7) forming This is an optical transmission fiber whose sheath material is a polymer consisting of at least one fluoroalkyl methacrylate represented by

The methyl methacrylate polymer used as the core material E of the optical transmission fiber of the present invention is at least 4? Omolinsane is a polymer consisting of methyl methacrylate units. Examples include methyl methacrylate acrylate and ethyl alcohol within a range not exceeding 104 Ru. These copolymerized monomers improve the processability and heat resistance of the methyl methacrylic heavy metal body, but since adding a large amount tends to reduce the optical transmission performance, it is necessary to copolymerize with 118 within 1e molar. I like being carried away.

The main component of the sheath material of the optical transmission fiber of the present invention [Metac 9-acid fluoroalkyl] is derived from the following general formula (in the formula, X is tetrafluoroethylene ef) and a random bond between vinyliso7 fluoride. The total number of structures of xt-forming flash and (b) is 2 to 6,
And a chain in which the constituent number ratio (e) 7M of both is 1/S or S, and n is 1 or! A telomerization reaction of a methacrylic acid ester represented by
It is easily synthesized from acid chloride. However, if the number of tetrafluoroethylene or vinylidene heptadide structural units constituting X of the alcohol component of the fluoroalkyl metatate exceeds 6 in terms of the number of monomers, The heat resistance deteriorates, making it unsuitable as a sheath material, and
(to the tetrafluoroethylene constituting) and the structural unit of vinylidene fluoride (7) (V)/(V) is 11
If it is less than 5, the refractive index becomes high and the difference from the refractive index of the methyl methacrylate polymer that is the core material becomes small, and the aperture angle becomes small, resulting in a decrease in the amount of transmitted light. On the other hand, when the value of Maku exceeds 5, the 7-phrase contained in X = lden (
v) Since the 6-structure ratio becomes too small, the adhesion to the methyl methacrylate polymer that is the core material deteriorates, resulting in a decrease in optical transmission performance. Therefore, the structure of X is ('L-)/
It is preferable that ('/) be II@l, which satisfies the above-mentioned composition ratio.

The sheath material of the optical transmission fiber of the present invention is a combination of 7λ Oda Alki★ or 21
It may be one or more co-heavy metal bodies, or they may be combined with an arylate or methacrylate monomer such as the following general formula (in the formula fluoroalkyl methacrylate represented by monomer, 2
, 2.2-) Rifluorethyl methacrylate, 1s
Fluoroalkyl methacrylate monomers such as ly1t't5t'-hequinafluoro-2-gexyl methacrylate, perfluoro-1-butyl methacrylate, methyl atatyrate, ethyl acrylate, butyl methacrylate, and methacrylate groups. It may also be a polymer.

However, if the content of the copolymerized monomer becomes too large, the adhesion with the methyl methacrylate heavy metal body used as the core material may decrease, the refractive index difference between the core and sheath becomes small, and the amount of transmitted light decreases. Therefore, it is preferable to carry out copolymerization in a range of 507 moles or less in terms of monomer moles.

The optical transmission fiber II of this company is made by melt-spinning the core material and sheath material polymers from a core-sheath spinneret, or by melting the KII material on the surface of the spun core material into IkIIi1.
It can be manufactured by drying.

Hereinafter, the present invention will be explained in more detail by Examples. Examples 1 to Lu, Comparative Examples 1 to 4 The optical transmission fiber was manufactured by the route shown below.

(1) Preparation of methyl methacrylate polymer rod Polymerization (purification of the monomers used is carried out by mercury porosimeter method (Module made of porous polygoobile having a fixed pore diameter of 700 mm, for example, I11 and I11) It was incorporated into the 5-type purification apparatus shown in Iris!- and purified by gas filtration method.Di-t-butyl peroxide,
The t-butyl mer*butane was used after being filtered through a 7-tonne filter having a pore size of α1-. The monomers and additives were prepared in a clean room filled with clean air passed through a module made of porous propylene hollow fibers with a pore diameter of 7 ooof as measured by a mercury porosimeter method.

The methyl methacrylate-based heavy metal body was prepared by using a module made of porous polypyrene hollow fibers with a round pore diameter of 70 mm as measured by a mercury porosimeter (washed with distilled water with a higher concentration and dried in a clean room). Inside 4110■
A monomer composition prepared under the conditions listed in Table 1 Wc was placed in a Pyrex glass tube with a wall thickness of 1 and a length of 50 mm in a clean room, and then mixed with dry ice and methanol. Using a refrigerant consisting of 10-' Hf, freeze-degassing was repeated to remove dissolved air, the tube was placed in an Ell tube under reduced pressure, and then immersed in an oil bath at 140°C for 4 hours for polymerization. Depends on the method.

By this polymerization method, 1110-
1. A methyl methacrylate polymer rod I-m having a length of about 200 m was obtained.

Table 1 MM person: Methyl methacrylate M person: Methyl acrylate % -ButlFI: %-Butyl mercaptan DT
BPO di-1-butyl peroxide An example of a preferred purifying apparatus for applying the present invention is Pyrex glass. (1) is a container in which the casing to be purified is placed, and is heated to a temperature of 11 using electric heat or the like.

(2) is used when distilling under reduced pressure with a capillary.

(3) or other connection S & Egomi to spend one person spc Ji India (Shibata Kagakukiki Co., Ltd. 11)
T-Using.

(4) is a rectification column, and (1) is a part of a filter. To prevent the gas from condensing on a part of this filter, a tape heater (6) was wrapped around it to heat it.The gas is filtered through this filter (5) and condensed in the cooling II (,7). , only the moat is stored in the container (8). (9) is a Teflon cock and if the housing has a high boiling point, (10) K
A vacuum pump is connected to keep Makuuchi at reduced pressure. Figure 2 is (%)
The ICJI porous hollow fibers (11) inside the glass tube were bundled at the filter's second section mrg, and both ends (12) and (1) were filled with T epoxy resin, so the terminals (15) were kojiji. In the terminal (12), the hollow S of the hollow fiber is one piece. At the dose number 2- in FIG. 1, the gas passes through the porous membrane from the outside l1ii of the hollow fibers, passes through the hollow portion, and is released from its open end (12). It is also possible to supply the gas to be treated from inside the hollow fiber. In addition, the filter can be placed vertically instead of horizontally, and the hollow fiber can also be placed at the terminal (13), (12) (
Gas may be allowed to enter and exit from both sides (1 island).

(1) Production of fluoroalkyl metatallylate main polymer General formula (in the formula, ) total number of components is 2 to 4
The synthesis of metatarylic fluoroalkyl, which is a chain whose number ratio (1)/(b) is S/S to 5, where n is 1 or 2, is as follows. I followed the route shown. First, 0 to 100 parts by weight of tetrafluoroethylene, 0 to 1011 parts by weight of vinylidene fluoride, methanol or ethanol! 100 parts by weight and 100 parts by weight of G-t-butyl peroxide were placed in a stainless steel autoclave (140°C to 150°C, SO
After telomerization reaction under pressure of 0 to 7001/m electric current to obtain fluoroalkyl alcohol, fractionation by distillation, elemental analysis, and NMR to determine the composition ratio of tetrafluoroethylene and vinylidene heptadide that constitute the fluoroalkyl chain. Ta. Then, these fluoromol 100 to 20
0 parts by weight, 100 parts by weight of methacrylic acid toride, and 5 parts by weight of p-methoxyphenol were charged into a flask, and the reaction was heated under reflux for 4 hours, followed by fractional distillation. An alkyl trout conductor was created. The methacrylic fluoroalkyl polymer contains azobisisobutytetraethyl9α based on 100 parts by weight of the total monomers.
lll1. Add n-dodecyl mercaptan aS@,
It was prepared in seven rows at 80°C for 10 hours.

The composition of the preparation layer and the genus ratio of the obtained polymer (lit)
Manufacture of optical fiber
This spinning device consists of a chatter II (14) for attaching a rod that can slide at a constant speed on a molar rail, and clean nitrogen gas that passes through a module made of raw silk in porous polypropylene with a pore size of 7aOk determined by the mercury porosimeter method. A rod tip heater (1s) filled with a cooling II (14) surrounded by a polycarmenate cylinder, a container 11 (17) for coating the sheath material, and a drying tower for the coated yarn (18χ The cooling section (16) #C, which consists of a nip roller (1?) and a winder (2G), feeds nitrogen gas through an air filter (21).

(1) After the heavily loaded methyl methacrylate polymer rod (22) is woven into the chuck 15 (14), the lowering speed of the chuck, the winding speed of the nip roller, and the heating temperature are After suitably adjusting the conditions so that no graining occurs, the fibers are coated with ethyl acetate fIII containing 20% by weight of Cm drawn and spun fireflies and polymers M to G, respectively, and dried to form a superfiber. By this method, optical transmission fibers having an outer diameter of 1 cm shown in Examples 1 to 1 and Comparative Examples 1 to 4 were fabricated.

(1v) Evaluation of optical transmission loss The transmission loss of the optical transmission fiber obtained is 4m! 1F - "C11m" was determined by the apparatus shown.

The light emitted from a halogen lamp (1f12) driven by a stabilized electric current is parallelized by a lens (10B), and then passed through an interference filter (164) II.
The light is made monochromatic by C, and is focused at the focus of a light transmission fiber (16O) and a lens (105) with a high numerical aperture.

The light is made to enter the optical transmission fiber (100) by adjusting the input end (106) of the optical transmission fiber so that it is located at this focal point.

The light incident from the input end @ (1aa) is attenuated by -1 and then emitted from the output end 1ji (1a7).
Envyed by IL, current-voltage conversion Maro's amplifier (10?)
The voltage value amplified by the voltage needle (110) is read as a voltage value.

@Measurement of transmission loss is performed using the following procedure.

First, the optical transmission fiber (1oo) is made to have a size of 10 (,
Both end faces are cut at right angles to the fiber axis, finished to have a smooth surface, and the input end face (104) and the output end face (107) are placed in the above device.
) so that it does not move during measurement. Read the indicated value of the 1,1 voltage needle in the dark *. Let this voltage value be .

Next, the interior lights of the car are turned on, the emission end face (107) is removed from the device, and the optical transmission fiber (100) is cut from this end face at a point (111) of length L. Then, finish the end face of the optical fiber that is attached to the device with a 54-fiber axis trap angle (finish) and attach it to the optical fiber as the new output end face.During these operations, the incident In order to keep the amount of light constant, be careful not to move the incident end face (104).Tap in a dark room again, read the indicated value of the voltage needle, and take this as h.

Optical transmission loss (α) is calculated using the following formula (.

H) I α-2 l-log (-T?) (am/km
) where L: length of the optical fiber (k) 11, Il: prefix (voltage needle reading) Note that the conditions for the present invention are as follows.

Interference filter (dominant wavelength): 646 n Oboro 10 (*maximum of optical fiber): 15 @ 1 t (ZIF) @ cutting maximum): 1 o @ ]) (immediately after l bin): 1? O ■ The bobbin is used to make the device compact, and the input end face (1
04) and the output end face (10A) is 19III degrees, and the remaining optical fiber is placed in a bin (not shown).
Roll K.

Table 2 shows the results of each example and Hishokuju.

Easy table drawing! - No. 1fjA is a diagram showing an example of the monomer III device of the present invention, Figure 112 is a diagram showing an example of the monomer purification filter of the present IA@, and No. 1II is a diagram showing an example of the spinning equipment for manufacturing the monomer transmission fiber. Explanatory diagram No. 41I is an explanatory diagram of a transmission loss measuring device for a transmission barrier.

In the figure 1: Wrinkle treatment liquid! ! Container 4: Rectification column 5: Filter s: *IIt body container 11: Porous hollow fiber #14: O-rad deposition stage chatter section 15: Rod tip heater 17: IlN coating vessel 1
8: Drying tower 19: Nip roller for pulling pile 100: Optical transmission fiber 11; Hairogen lamp 104: Interference filter 104: Incoming end ring 107:
Output end @ 11j, near-odd diode 1oy
: Increase @ @ t16 : Voltage needle.

curtain/figure

Claims (1)

[Scope of Claims] t A methyl methacrylate-based polymer containing at least 90 mmol of methyl methacrylate units is used as a core material, calculated in terms of t monomer mole, and has a general formula (wherein X is tetrafluoro-tetraethylene and fluorinated It is composed of random bonds of vinylidene (b), and the total number of constituents of (b) and (a) forming X is 2 to 6,
and a chain having a constitutive ratio (to)/(a) of 115 to 5, where n represents 1 or 2) or a scissors compound α ) as a sheath material.