JPH0321910A - coated optical fiber - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a coated optical fiber in which the outer periphery of the optical fiber is coated with an energy ray-curable resin that is cured by irradiation with energy rays such as ultraviolet rays. It is something.

[Conventional technology]

In optical fibers used for optical communications, it is desirable to apply a plastic coating to the outer periphery of any optical fiber, whether it is an optical glass fiber or a silica-based glass fiber, immediately after being 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 it is made into a fiber or cracks caused by exposing the bare fiber to air. Energy ray-curable resins such as thermosetting silicone resins, ultraviolet curable resins (hereinafter also referred to as rUV resins), and radiation-curable resins are generally used for such plastic layers. In particular, the demand for UV resin-coated fibers is increasing.

Here, as the UV resin used for this coating, for example, epoxy acrylate, urethane acrylate, polyester acrylate, etc. are used, but they have the problem that the strength of the optical fiber may deteriorate when they absorb moisture. was.

In order to prevent moisture absorption by improving the adhesion between the optical fiber and the coating resin, additives such as silane coupling agents have conventionally been used.
A silane coupling agent that does not contain an amino group, such as that proposed in Japanese Patent No. 947, can hardly improve moisture resistance.

[Problem to be solved by the invention]

By the way, even if the moisture resistance can be improved using a silane coupling agent having an amino group, it is necessary to use a large amount of the silane coupling agent to improve the moisture resistance, and as a result, energy ray curable resin A phenomenon occurs in which the curing speed of the material slows down, resulting in a decrease in productivity. Furthermore, the use of a large amount of silane coupling agent having an amino group,
Because the silane coupling agent does not contain polymerizable carbon/carbon double bonds in its molecules, the silane coupling agent remains at the interface between the optical fiber and the coating resin over time even after the resin has undergone a curing reaction. There was a fear that it would precipitate.

In view of the above-mentioned current situation, the present invention has been developed to firmly bond the optical fiber and the coating resin without reducing the curing speed, to guarantee moisture resistance, and to add additives to the coating and the optical fiber after forming the coated optical fiber. The object of the present invention is to provide an excellent coated optical fiber that does not cause precipitation at the interface over time.

[Means to solve the problem]

As a result of our efforts in research and development to achieve the above object, the present inventors have found that heat resistance is greatly improved if the energy ray-curable resin forming the coating layer has a carbamoyl group as its basic component. With this heading, we have arrived at the present invention.

That is, the present invention provides a coated optical fiber having a coating made of an energy ray curable resin on the outer periphery of the optical fiber, wherein the energy ray curable resin contains a (meth)acrylic oligomer, a reactive diluent, and a polymerization initiator. The coated optical fiber is polymerized as a basic component and the reactive diluent contains a carbamoyl group.

In a particularly preferred embodiment of the present invention, the carbamoyl group-containing reactive diluent of the present invention is a compound represented by the following general formula +I+.

General formula +1) (However, in formula +1), R+ represents a hydrogen atom or a methyl group, R* and Rs may be the same or different from each other, each represents a hydrogen atom, an alkyl group, or an aryl group, and n is 0 or In the present invention, the carbamoyl group-containing reactive diluent is present in an energy beam curable resin containing a positive integer of 1 to 1O by weight or more.
It is particularly preferred that the content is less than 0 parts by weight.

This means that if it is less than IO parts by weight, it is not effective in improving adhesion.
On the other hand, if it exceeds 80 parts by weight, the viscosity of the resin as a whole decreases, and workability and applicability deteriorate significantly.

[Effect]

In the coated optical fiber of the present invention, since the resin forming the coating layer has a reactive diluent having a carbamoyl group as a basic component, it is possible to improve the adhesion between the coated optical fiber and the coated optical fiber in comparison with conventional products. It turns out it can be done. Further, since the reactive diluent having a carbamoyl group has a reactive carbon-carbon double bond, a chemical bond can be generated through a curing reaction, thereby preventing precipitation at the interface between the optical fiber and the coating over time.

The energy ray-curable resin containing a carbamoyl group of the present invention uses a carbamoyl group as a reactive diluent among a (meth)acrylic oligomer, a reactive diluent, and a polymerization initiator, which are polymerization components of raw materials forming the resin. This can be achieved by using a compound containing. The coating resin of the present invention will be explained in detail below.

The coating resin of the present invention is polymerized using a (meth)acrylic oligomer, a reactive diluent, and a polymerization initiator as essential basic components, and a compound containing a carbamoyl group is used as the reactive diluent. , molecular weight l000~t
It belongs to ooooo.

The (meth)acrylic oligomer according to the present invention consists of a polyol component, an isocyanate component, and an acrylate component. Examples of the polyol component include polyether polyols such as polyoxytetramethylene glycol, polypropylene glycol, and polyethylene glycol, polyolefin glycols, and polyesters. Examples include polyol, polycarbonate polyol, polycabrolactone polyol, 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-hydroxybutyl (meth)acrylate, are used.

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

The reactive diluent of the present invention is preferably a compound containing a carbamoyl group in its molecule, particularly preferably a compound containing a carbamoyl group represented by the following general formula +1).

General formula +Il RI 1 Here, in the above general formula (1), R1 is a hydrogen atom or a methyl group, and Re. Rs may be the same or different, and each represents a hydrogen atom, such as a methyl group, an ethyl group,
More specifically, the compound represented by the above general formula (1) is an alkyl group such as a probyl group or a butyl group, or an aryl group such as a phenyl group, and n is 0 or a positive integer from 1 to IO. Examples include the following, but the present invention is not limited thereto.

Namely, carbamoyl methyl acrylate, carbamoyl methyl methacrylate, carbamoylethyl acrylate, carbamoylethyl methacrylate, carbamoyl brobyl acrylate, carbamoyl brobyl methacrylate, dimethylcarbamoylmethyl acrylate, dimethylcarbamoylmethyl methacrylate, dimethylcarbamoylethyl acrylate, dimethylcarbamoylethyl methacrylate, diphenylene Carbamoyl methyl acrylate, diphenylcarbamoyl methyl methacrylate, diphenylcarbamoylethyl acrylate, diphenylcarbamoylethyl methacrylate, carbamoyl acrylate, carbamoyl methacrylate, methylcarbamoyl butyl acrylate, methylcarbamoylbutyl methacrylate, methylcarbamoylpentyl acrylate, methylcarbamoylpentyl methacrylate, methylcarbamoyhexyl acrylate,
Methyl carbamoylhexyl methacrylate, methylcarbahebutyl acrylate, methylcarbamoylheptyl methacrylate, methylcarbamoyl octyl acrylate, methylcarbamoyl octyl methacrylate,
Methylcarbamoylnonyl acrylate, methylcarbamoylnonylmethacrylate, methylcarbamoyldecyl acrylate, methylcarbamoyldecyl methacrylate, methylcarbamoylmethylacrylate, methylcarbamoylmethylmethacrylate, methylcarbamoylethyl acrylate, methylcarbamoylethyl methacrylate, methylcarbamoylpropyl acrylate, methylcarbamoylpropyl methacrylate, ethyl carbamoyl methyl acrylate, ethyl carbamoyl methyl methacrylate, ethyl carbamoyl ethyl acrylate, ethyl carbamoyl ethyl methacrylate,
Ethylcarbamoylpropyl acrylate, Ethylcarbamoylpropyl methacrylate, Propylcarbamoylmethylacrylate, Propylcarbamoylmethylmethacrylate, Propylcarbamoylethyl acrylate, Propylcarbamoylethyl methacrylate, Provilcarbamoylpipyracrylate, Propylcarbamoylpipyrmethacrylate, Isopropylcarbamoylmethylacrylate , Isopropyl Carbamoyl Methacrylate, Isopropyl Carbamoylethyl Acrylate, Isopropyl Carbamoylethyl Methacrylate, Isopropyl Carbamoyl Propyl Acrylate, Isopropyl Carbamoyl Propyl Methacrylate, Butyl Carbamoyl Methacrylate, Butyl Carbamoyl Methacrylate, Butyl Carbamoyl Ethyl Acrylate, Butyl Carbamoyl Examples include ethyl methacrylate, butyl carbamoyl propyl acrylate, and butyl carbamoyl propyl methacrylate.

Furthermore, in the present invention, in addition to the carbamoyl group-containing compound described above, it is also possible to use the following diluents, such as 2-ethylhexyl (meth)acrylate, tetrahydrofurfuryl alcohol caprolactone adduct. (meth)acrylate of nonylphenol ethylene oxide adduct (meth)acrylate 1
・, 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, pentaerythritol tri(meth)
Acrylate, mono-A or poly(meth)acrylates such as epoxy(meth)acrylate synthesized from bisphenol diglycidyl ether, diallyl adipate,
Examples include allyl esters such as diallyl phthalate, triallyl trimellitate, and triallyl isocyanurate, and vinyl compounds such as styrene and vinyl acetate.

In the present invention, it is particularly preferable that the above-mentioned reactive diluent containing a carbamoyl group is contained in the energy ray curable resin in a proportion of IO parts by weight or more and less than 80 parts by weight. If it is less than 10 parts by weight, it is inconvenient because it is ineffective in improving adhesion, and if it exceeds 80 parts by weight, the viscosity of the entire resin decreases, resulting in poor workability and coating properties, which is not preferable.

The polymerization initiator of the present invention is preferably one that can quickly cure the resin composition by irradiation with energy rays,
Particularly suitable are those used as initiators and sensitizers for ultraviolet curable paints, such as benzoin, benzoin methyl ether, benzoin ethyl ether, penzoin isobutyl ether, penzoin isobutyl ether, 2-methylbenzoin, Penzophenone, Michler's ketone, benzyl, benzyl dimethyl ketal, benzyl diethyl ketal, anthraquinone, methylanthraquinone, 2.2-diethoxyacetophenone, 2-
Methylthioxanthone, 2-isobrobylthioxanthone, 2-chlorothioxanthone, anthracene, 1.1
-dichloroacetophenone, methyl orthobenzoyl benzoate 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 IO parts by weight, preferably 1 to IO parts by weight
5 parts by weight. 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.

The energy ray-curable resin of the present invention has the above-mentioned (meth)acrylic oligomer, reactive diluent, and polymerization initiator as essential components, and optionally contains acrylic resin, polyamide resin, polyether resin, polyurethane resin, and polyamide. Various modification resins such as imide resins, silicone resins, and phenolic resins, and various additives such as organosilicon compounds, surfactants, and sensitizers may be blended, and the overall viscosity is determined from the viewpoint of workability. Therefore, it is desirable that the temperature is normally adjusted to a range of 1,000 to 10,000 centivoise (25°C).

Furthermore, in order to further improve the adhesion, it is also possible to use a small amount of silane coupling agent, such as 0.1 to 5 parts by weight.

The coated optical fiber of the present invention may be manufactured by a conventionally known resin coating forming method of this type. For example, an energy beam curing type in which an optical fiber base material is sent into a drawing furnace, heated and melted, and drawn into an optical fiber (glass fiber), and then a reactive diluent and a polymerization initiator are added as described above using a coating device. After applying the resin, the applied layer is cured by irradiating the resin with energy rays to form a coated optical fiber, which is then wound up while being taken off. There are no particular limitations on the material, assembly, 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.

Example 1 5I with stirrer, cooler and thermometer! 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, the infrared absorption spectrum shows that 2 2 7 of isocyanate groups
The reaction was continued until the characteristic absorption band at 0 cta-' disappeared.

70 parts of the urethane acrylate oligomer thus obtained (hereinafter, parts by weight are expressed unless otherwise specified)
30 parts of methyl carbamoyl methyl acrylate as a reactive diluent and 3 parts of benzoin methyl ether as a polymerization initiator were added to the mixture to obtain an energy ray curable resin. This energy ray curable resin was applied to the outer periphery of an 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 (product of the present invention).

1 m of the coated optical fiber of the present invention obtained above was
The optical fiber was wound around a mandrel with a diameter of 0 CI 1 and 3 strands, immersed in water, and the time it took for the optical fiber to break was measured, and it was found to be 15 days.

Example 2 Urethane acrylate oligomer 7 obtained in Example 1
0 parts, 30 parts of ethyl carbamoylpropyl 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. A coated optical fiber (product of the present invention) was manufactured using this energy ray curable resin in the same manner as in Example 1, and an underwater winding test was conducted on this coated optical fiber in the same manner as in Example 1. The time was 14 days.

Example 3 Urethane acrylate oligomer 7 prepared in Example 1
0 parts' were blended with 30 parts of isopropylcarbamoylpropyl acrylate as a reactive diluent and 3 parts of benzoin methyl ether as a polymerization initiator 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 Example 1,
When this coated optical fiber was subjected to the same underwater winding test as in Example 1, it took 14 days to break.

Comparative example! Urethane acrylate oligomer-9 synthesized in Example 1
5 parts of methylcarbamoyl methyl acrylate as a reactive diluent and 3 parts of benzoin methyl ether as a polymerization initiator were added to 5 parts to obtain an energy ray curable resin. A coated optical fiber (comparative product) was manufactured using this energy ray curable resin in the same manner as in Example 1, and an underwater winding test was conducted in the same manner as in Example 1. As a result, the time required for the optical fiber to break was 3. It was for days.

Comparative Example 2 Urethane acrylate oligomer 7 synthesized in Example 1
0 parts, 30 parts of 2-ethylhexyl 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.

A coated optical fiber (comparative product) was manufactured using this energy ray curable resin in the same manner as in Example 1, and an underwater winding test was conducted in the same manner as in Example 1. As a result, the time required for the optical fiber to break was 24. It was time.

Comparative Example 3 Urethane acrylate oligomer-1 synthesized in Example 1
5 parts, 85 parts of ethyl carbamoylethyl 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. An attempt was made to manufacture a coated optical fiber (comparative product) using this energy ray curable resin in the same manner as in Example 1, but the viscosity of the energy ray curable resin was extremely low (5 at 25°C).
00 centivoise), and the manufactured fiber was severely damaged in appearance and shape.

From the results of the above Examples and Comparative Examples, it can be seen that the fibers of the coated resin layer having the structure of the present invention have excellent moisture absorption resistance, and that the fibers in the limited range of the present invention are effective.

〔Effect of the invention〕

As explained above, the coated optical fiber of the present invention uses a compound containing a carbamoyl group as a reactive diluent, which is a basic component of the resin, as the resin forming the coating layer. As a result, it is a coated fiber with greatly improved adhesion between the optical fiber and the coating resin, the time taken to break in an underwater winding test is extended, and the moisture absorption resistance is improved. In addition, the problem of slow curing speed and precipitation of additives at the interface between the optical fiber and the coating resin, which is the problem with conventional coated fibers with improved adhesion by adding silane coupling agents, has been eliminated. , is an excellent coated optical fiber.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a coated optical fiber according to the present invention and a conventional coated optical fiber, where l represents an optical fiber, 2 represents an energy beam-curable resin coating layer, and 3 represents a coated optical fiber.

Claims (3)

[Claims] (1) In a coated optical fiber having a coating made of an energy ray curable resin on the outer periphery of the optical fiber, the energy ray curable resin contains (meth)acrylic oligomer, a reactive diluent, and a polymerization initiator as basic components. 1. A coated optical fiber characterized in that the reactive diluent contains a carbamoyl group. (2) The coated optical fiber according to claim (1), wherein the reactive diluent is a compound containing a carbamoyl group represented by the following general formula (I). General formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. represents a group or an aryl group, and n
represents 0 or a positive integer from 1 to 10] (3) The coated optical fiber according to claim 1, wherein the reactive diluent containing a carbamoyl group is contained in the energy ray curable resin in a proportion of 10 parts by weight or more and less than 80 parts by weight.