JPH02223903A - Coated optical fiber - Google Patents

Abstract

PURPOSE:To obtain the coated optical fiber having excellent heat resistance, to extremely prolong the time to the breakage of the fiber in a high-temp. atmosphere when this coated optical fiber is used, and to improve heat resistance by incorporating a polycyclic compd. into the reactive diluent in a coating layer. CONSTITUTION:An energy beam curing type resin layer 2 of the coated optical fiber 3 having the energy beam curing type resin layer 2 on the outer periphery of the optical fiber 1 consists of an acryl oligomer, polymn. initiator and reactive diluent. This reactive diluent contains the polycyclic compd. In a more preferably example, this polycyclic compd. is a tricyclo compd. is adamantane or the deriv. thereof. This polycyclic compd. has a tricyclo ring structure in the molecule and since the structure is extremely rigid, the heat resistance is improved. The problem of the heat resistance of the optical fiber coating is solved in this way and the coated optical fiber which can be laid even when there is the possibility of exposing the fiber to a high temp. is obtd.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to an improvement of a (limb) ν optical fiber in which a coating of an energy ray-curable resin that is cured by irradiation with energy rays such as ultraviolet rays is formed on the outer periphery of the optical fiber. It is related to.

[Conventional technology]

For fibers to be used in optical communications, it is desirable to apply a plastic coating to the outer periphery of any fiber, whether it is an optical glass fiber or a silica-based glass fiber, immediately after it is made into a fiber. This is to prevent the strength of the fiber from deteriorating due to scratches on the surface of the fiber that occur when the fiber is made into a fiber or cracks that grow when the bare fiber is exposed to air. Such a plus deck layer is generally made of thermosetting silicone resin or ultraviolet curable resin (hereinafter also abbreviated as rUV resin layer).
Energy ray-curable resins such as UV resins have been used, and in recent years, demand for UV resin-coated fibers has particularly increased.

Here, as the UV resin used for this coating, for example, epoxy acrylate, urethane acrylate, polyester acrylate, etc. are used. In addition, recently, υV resins for coating optical fibers with improved curability and heat resistance by adding bicyclo compounds or dicyclo compounds have been reported (JP-A-63-35438, JP-A-63-107845). Public bulletin).

(Problem to be solved by the invention) By the way, U, which is currently used as an optical fiber coating material,
V resin has a problem in that it cannot be said to be excellent in terms of heat resistance. Coating resins using bicyclo compounds or dicyclo compounds described in the above publications also include
Although heat resistance has improved, it is still not sufficient.

For this reason, the current optical fibers have the disadvantage that they can be used in places where there is no possibility of exposure to high temperatures, but cannot be used in places where there is a risk of exposure to high temperatures.

In view of the current situation, it is an object of the present invention to solve the problem of heat resistance of optical fiber coatings and to provide a coated optical fiber that can be installed even when exposed to high temperatures.

[Means to solve the problem]

As a result of the efforts of the present inventors in research and development to achieve the above object, they were able to arrive at the coated optical fiber of the present invention having a coated resin layer structure containing a novel reactive diluent.

That is, the present invention provides a coated optical fiber having an energy ray curable resin layer on the outer periphery of the optical fiber, wherein the energy ray curable resin layer is composed of a (meth)acrylic oligomer, a polymerization initiator, and a reactive diluent, and the reaction The coated optical fiber is characterized in that the diluent contains a polycyclic compound.

Particularly preferred embodiments of the present invention include the coated optical fiber characterized in that the polycyclic compound is a tricyclo compound, the coated optical fiber characterized in that the polycyclic compound is adamancune or its rust conductor. Mention may be made of coated optical fibers.

It is particularly preferable that the reactive diluent containing the polycyclic compound of the present invention is contained in the energy ray curable resin in a proportion of 10 parts by weight or more and less than 90 parts by weight.

[Effect]

Since the coated optical fiber of the present invention contains a polycyclic compound in the reactive diluent, the heat resistance of the coated fiber can be improved. The reason for this is thought to be that the polycyclic compound according to the present invention has a tricyclocyclic structure in its molecule, and this structure is very rigid, which can improve heat resistance.

The coating resin of the present invention essentially contains a (meth)acrylic oligomer polymerization initiator and a reactive diluent containing a polycyclic compound.

The (meth)acrylic oligomer in the present invention consists of a polyol component, an incyanate component, and an acrylate component, and has molecules 1). ooo to 100.000, and examples of the polyol component include polyether polyols such as polyoxytetramethylene glycol, polypropylene glycol, and polyethylene glycol, polyolefin glycols, polyester polyols, polycarbonate polyols, and polycaprolactone polyols.

Further, as the isocyanate component, for example, tolylene diisocyanate, diphenylmethane diisocyanate, p
-7 Enylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, and the like.

As the acrylate component, those having a hydroxyalkyl group having about 2 to 4 carbon atoms, such as 2-hydroxyethyl (meth)acrylate and 2-hydroxypropyl (meth)acrylate, are used.

The reactive diluent according to the present invention essentially contains a polycyclic compound, and in particular, one having a tricyclo ring structure is preferable.
For example, 7'damantyl acrylate.

Examples include 2-methyl adamantyl acrylate, 2-ethyl adamantyl acrylate, and 2-7 enyl adamantyl acrylate.

In addition to the above-mentioned polycyclic compounds, the reactive diluent of the present invention can also include the following diluents, such as 2-ethylhexyl (meth)acrylate, tetrahydrofurfuryl alcohol caprolactone adduct, etc. (
Meta) acrylate.

Nonylphenol ethylene oxide adduct (meth)
Acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, bisphenol diethylene glycol di(meth)acrylate, hydrogenated bisphenol triethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, penta These include mono- to poly(meth)acrylates such as erythritol tri(meth)acrylate and t-nieboxy(meth)acrylate synthesized from bisphenol diglycidyl ether.

Furthermore, using the vinyl compound shown below as a reactive diluent,
It is also possible to use them together.

For example, diallyl adipate, diallyl phthalate.

These include allyl esters such as triallyl trimellitate and triallyl isocyanurate, styrene, vinyl acetate, N-vinylpyrrolidone, N,N-dimethylaminopropylacrylamide, N,trimethylaminoethyl acrylate, and the like.

In the present invention, it is particularly preferable that the polycyclic compound is contained in the energy ray curable resin in a proportion of 0 parts by weight or more and less than 90 parts by weight. If the content is less than 10 parts by weight, it is ineffective and inconvenient in terms of improving heat resistance because the content is small, and if it exceeds 90 parts by weight, the viscosity of the resin as a whole decreases and workability and coating properties are significantly deteriorated, which is undesirable. .

The invention! It is preferable that the fi-initiator be one that can quickly cure the resin composition by irradiation with energy rays.
7) Especially as an initiator for UV-curable paints.

Sensitizers used in 17 are suitable, such as benzoin, benzoin methyl ether.

Benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether.

2-Methylbenzoin, benzophenone, Michler's ketone, benzyl, benzyl dimethyl ketal, benzyl diethyl ketal, anthraquinone.

Examples include methylanthraquinone, 2,2-jethoxyacetophenone, 2-methylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, anthracene, 1,1-dichloroacetophenone, methylorthobenzoylbenzoate, and the like.

Also included are those in which these polymerization initiators are used in combination with small amounts of sensitizing aids such as amines.

In the present invention, the amount of these polymerization initiators added is 100% of the total amount of (meth)acrylic oligomer and reactive diluent.
Usually about 1 to 10 parts by weight, preferably 1 to 10 parts by weight
There are 5 cities. If this amount is too small, the curability cannot be satisfied, and even if it exceeds a predetermined amount, no further improvement in the curing rate can be expected.

Energy ray curable resin +2 of the present invention, the (meth)acrylic oligomer described in h, a reactive diluent, and a polymerization initiator are essential components, and if necessary, an acrylic resin, a polyamide resin, a polyether resin, a polyurethane resin. , various modification resins such as polyamide-imide resins, silicone resins, and phenolic resins, and various additives such as organosilicon compounds, surfactants, and sensitizers, and the overall viscosity depends on workability. From the point of view, usually 1,000 to io,
It is desirable that the temperature be adjusted to a range of ooo centivoise (25° C.).

The wll-end optical fiber manufacturing method of the present invention may be based on a conventionally known resin coating forming method of this type. For example, the fiber preform is sent into a drawing furnace, heated and melted and drawn into an optical fiber (glass fiber), and then a coating device is used to add a reactive diluent and a polymerization initiator as described above. After applying the resin, the applied layer is cured by irradiation with the energy beam, and the coated optical fiber and 12
This method involves winding it up while taking it. There are no particular limitations on the material, composition, etc. of the optical fiber.

〔Example〕

Hereinafter, the structure and effects of the present invention will be further explained by giving specific examples and comparative examples of the present invention.

Implementation full! 5j with stirrer, cooler and meter! 1 mole of polyoxytetramethylene glycol having an average molecular weight of 2000 and 2 moles of tolylene diisocyanate were placed in a four-bottle flask and reacted at 60 to 70°C for 2 hours. Then 2
- Adding 2 moles of hydroxyethyl acrylate, infrared absorption spectrum shows 2270 c of the incyanate group.
The reaction was continued until the characteristic absorption band of m'' disappeared.

60 parts of the urethane acrylate oligomer thus obtained (hereinafter, parts by weight are expressed unless otherwise specified)
and adamantyl acrylate 40 as a reactive diluent.
and 3 parts of benzoin methyl ether as a polymerization initiator to obtain an energy ray-curable resin. This energy ray curable resin was applied around the optical fiber having the structure shown in FIG. 1 and cured to form a second coating layer, thereby producing a coated optical fiber 3 (product of the present invention).

One meter of the coated optical fiber obtained above was wound around a mandrel with a length of 501 mm and a diameter of 3 mm, and was left in an atmosphere of 200°C and 1r.The time it took for the optical fiber to break was measured and was found to be 16 days. .

Example 2 Example! Urethane acrylate oligomer 6 synthesized by
0 parts, 40 parts of 2-methyladamantyl acrylate as a reactive diluent, and 3 parts of benzoin methyl ether as a polymerization initiator were blended to obtain an energy ray-curable resin.

Using this energy ray-curable resin, a coated optical fiber (product of the present invention) was manufactured in the same manner as in the example type. When this coated optical fiber was wound in the same manner as in Example 1 and a heat resistance test was conducted, the time until breakage was 16 days.

Example 3 Example! Urethane acrylate oligomer 6 synthesized by
0 parts, 40 parts of 2-phenyladamantyl acrylate as a reactive diluent, and 3 parts of benzoyl methyl ether as a polymerization initiator were blended to obtain an energy ray-curable resin. Example using this energy ray curable resin! A coated optical fiber (product of the present invention) was manufactured in the same manner as above. When this coated optical fiber was wrapped in the same manner as in Example 1 and a heat resistance test was conducted, the time until breakage was 18 days.

Comparative Example 1 Urethane acrylate oligomer 9 synthesized in Example 1
5 parts adamantyl acrylate as a reactive diluent
and 3 parts of benzoin methyl ether as a polymerization initiator to obtain an energy ray-curable resin. This energy ray curable resin was applied around the optical fiber 1 having the structure shown in FIG. 1 and cured to form a coating layer 2, thereby producing a coated optical fiber 3 (comparative product). When this coated optical fiber was wrapped in the same manner as in Example 1 and subjected to a heat resistance test, it took only two days to break.

Comparative Example 2 Example! Urethane acrylate oligomer 6 synthesized by
0 parts isobornyl acrylate 4 as a reactive diluent
0 parts and 3 parts of benzoin methyl ether as a polymerization initiator were blended to obtain an energy ray curable resin number. This energy ray curing resin is used to create an optical fiber l having the structure shown in Figure 1.
A coated optical fiber 3 (comparative product) was manufactured by forming a coating layer 2 by applying the coating around the fiber and curing it. When this coated optical fiber was subjected to a 4-wrap heat resistance test similar to that in Example N1, it took only 24 hours to break.

Comparative Example 3 Urethane acrylate oligomer 5 synthesized in Example 1
Adamantyl acrylate 95 as a reactive diluent
and 3 parts of benzoin methyl ether as a polymerization initiator to obtain an energy ray-curable resin. This energy ray-curable resin has a structure shown in Figure 1.
A coated optical fiber 3 (comparative product) was manufactured by coating 41 around the fiber and curing it to form a coating layer 2. However, the viscosity of the energy ray-curable resin is about 76 at 25°C.
The produced fiber had a very low 0 centivoise and was severely damaged in appearance and shape.

From the results of the above Examples and Comparative Examples, it can be seen that the fiber of the coated resin layer having the structure of the present invention has excellent heat resistance, and that the fiber within the limited range of the present invention is effective.

〔Effect of the invention〕

As explained above (also as described above), the coated optical fiber of the present invention has the following characteristics: since the reactive diluent in the coating layer contains a polycyclic compound,
A coated optical fiber with excellent heat resistance can be provided. Therefore,
When the coated optical fiber of the present invention is used, the time required for the fiber to break in a high-temperature atmosphere is significantly longer than that of conventional products, achieving improved heat resistance.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a coated optical fiber of the present invention. 1: Optical fiber 2: Energy ray-curable resin coating layer containing a reactive diluent containing a polycyclic compound; 3: Coated optical fiber.

Claims (4)

[Claims] (1) In a coated optical fiber having an energy ray curable resin layer on the outer periphery of the optical fiber, the energy ray curable resin layer consists of a (meth)acrylic oligomer, a polymerization initiator, and a reactive diluent, and the reactive diluent A coated optical fiber characterized in that the agent contains a polycyclic compound. (2) The coated optical fiber according to claim (1), wherein the polycyclic compound is a tricyclo compound. (3) The coated optical fiber according to claim (1), wherein the polycyclic compound is adamantane or a derivative thereof. (4) The coated optical fiber according to claim 1, wherein the reactive diluent is contained in the energy ray curable resin in a proportion of 10 parts by weight or more and less than 90 parts by weight.