JPH08301959A - Polyurethane (meth) acrylate, resin composition and optical fiber using the same - Google Patents

Abstract

(57) [Summary] [Structure] A polyurethane (meth) acrylate obtained by reacting a polyol (I) having a (meth) acrylic group and a polyol (II) having a fluoroalkyl group with a polyisocyanate, and containing the same. The present invention provides a resin composition and an optical fiber using the resin composition as a clad material. [Effect] Since the resin composition of the present invention has a low refractive index, the plastic clad optical fiber of the present invention using this resin composition for the clad has a larger NA than the conventional one,
Light can be efficiently taken in from the light source.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to polyurethane (meth).
The present invention relates to an acrylate, a resin composition containing the acrylate, and a plastic-clad optical fiber having a cured product of the resin composition as a clad.

[0002]

2. Description of the Related Art Conventionally, silicon resin has been used as a clad material for plastic clad optical fibers.
(Japanese Patent Laid-Open No. 58-30703). However, since this clad material lacks mechanical strength, it is not possible to cope with the simplification of terminal treatment by crimping type connector attachment which is required in recent years. On the other hand, JP-A-62-250047, US Pat. No. 4,707,076, and JP-A-3-166.
As disclosed in JP-A-206 and JP-A-5-32749, a clad material using an ultraviolet curable resin composition has been proposed.

These resin compositions are excellent in mechanical strength because they have a cross-linked structure by curing with ultraviolet rays, and optical fibers using them as a clad material can be applied with a crimp type connector. When using these clad materials,
It also has the advantage of improving production speed.

[0004]

However, since the refractive index of these resin compositions is not sufficiently low, an optical fiber using these resin compositions as a clad is a parameter that represents the optical coupling efficiency with a light source element. (Numerical aperture)
However, there is a problem that the light from the light source cannot be efficiently taken into the optical fiber.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to have a high NA.
(EN) Provided are a plastic clad optical fiber which has the above-mentioned properties and which can be applied to a crimp type connector, and a resin which has a low refractive index and a large strength and is used as a clad material.

In order to solve the above problems, the inventors of the present invention have earnestly studied, and as a result, have developed a novel polyurethane acrylate, and by using it, it is suitable for a clad material of an optical fiber having a low refractive index and a high strength. The present invention has been completed by successfully providing a resin composition. That is, the present invention provides a polyurethane (meth) acrylate obtained by reacting a polyol (I) having a (meth) acrylic group and a polyol (II) having a fluoroalkyl group with a polyisocyanate, and a resin composition containing the same. And an optical fiber using this resin composition as a clad material.

Polyol (I) having (meth) acrylic group
Is a compound having two or more hydroxyl groups and one or more (meth) acrylic groups. The polyol (I) may be a diol having one (meth) acrylic group.

The preferred structure of the polyol (I) has the general formula
It is represented by (1) and / or (2). CH ₂ = CXCOOCH ₂ CH (OH) CH ₂ OH (1)

[Chemical 4] [In the formula, X is a hydrogen atom or a methyl group. ]

Polyol having fluoroalkyl group
(II) is a compound having at least one monovalent or divalent fluoroalkyl group and two or more hydroxyl groups.
The polyol (II) may be a diol having at least one fluoroalkyl group.

The preferred structure of the polyol (II) is represented by the following general formula (3), (4) or (5).

Embedded image [In the formula, n is an integer of 1 to 20, k is an integer of 1 to 3, and l is 0.
Alternatively, 1 and m are integers of 1 to 12. _{] HO (CH 2) i (} CF 2) j (CH 2) i OH (4) [ wherein, i is an integer of 0 to 2, j is an integer of from 1 to 10. ]

[Chemical 6] [In the formula, R ¹ and R ² are perfluoroalkyl groups having 1 to 10 carbon atoms and may be the same or different. ]

The polyisocyanate may be a diisocyanate. Specific examples of the polyisocyanate include isophorone diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, bisisocyanatomethylcyclohexane, tolylene diisocyanate and the like. Of these, isophorone diisocyanate and bisisocyanatomethylcyclohexane are preferable.

In the case of producing a polyurethane (meth) acrylate by reacting the polyol (I) and the polyol (II) with polyisocyanate, the polyol (I) and (I
The amount of polyisocyanate charged per 1 equivalent of the total hydroxyl groups of I) is preferably 0.5 to 2.0 equivalents of isocyanate groups, and particularly preferably 0.8 to 1.25 equivalents.

The ratio of the charged amounts of the polyol (I) and the polyol (II) is preferably (II) / ((I) + (II)) of 0.3 to 0.99. When it is less than 0.3, the amount of fluoroalkyl group is small and the refractive index is high, and when it is more than 0.99, the crosslink density is small and the strength after curing is small, which is not preferable. Particularly, 0.5 to 0.98 is preferable.

Further, the polyol (I) and the polyol (II)
Besides, polyol (III) having at least two hydroxyl groups may be added. Such a polyol (I
Examples of II) include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, polyethylene glycol and polytetramethylene glycol. . The amount of polyol (III) may be 0 to 20% by weight, for example 0 to 10% by weight, of the total amount of polyol (I) and polyol (II).

The reaction between these polyols and polyisocyanate is preferably carried out in the presence of a known urethanization catalyst such as dibutyltin dilaurate or dioctyltin dilaurate. The amount of urethanization catalyst may be 0 to 5% by weight of the polyisocyanate, for example 0.1 to 3% by weight. The reaction may be carried out in a solvent-free system or may use a solvent. As the solvent, an inert solvent such as benzene, toluene, tetrahydrofuran, isopropyl ether, acetone or methyl ethyl ketone can be used. The reaction is preferably carried out at 30 to 90 ° C for 1 to 24 hours.
At this time, a known polymerization inhibitor such as hydroquinone, methoxyhydroquinone, or di-t-butylmethylphenol may be added to prevent polymerization of the (meth) acrylic group. The amount of the polymerization inhibitor is 0 to 3 of the amount of the polyol (I).
It may be% by weight, for example 0.1 to 1% by weight. The average molecular weight of polyurethane (meth) acrylate is usually
1000 to 20000, preferably 2000 to 1000
It may be 0.

The resin composition of the present invention comprises a polyurethane (meth) acrylate, optionally a (meth) acrylate having no urethane group present, a coupling agent present if necessary, and a photopolymerization initiation present if necessary. The agent may be included.

Polyurethane in the resin composition of the present invention
The proportion of the (meth) acrylate is not particularly limited, but from the viewpoint of coatability at the time of production, it may be 5 to 99% of the resin composition.
%, For example 10 to 70% by weight is preferred.

The resin composition of the present invention has no urethane group other than the polyurethane (meth) acrylate of the present invention.
(Meth) acrylate may be included. Examples of the (meth) acrylate having no urethane group include the following compounds. Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, octyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth ) Acrylate, aliphatic group ester (meth) acrylates such as dimethyladamantyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, γ-methacryloxypropyltrimethoxysilane, allyl (meth) acrylate With functional groups such as (meta)
Examples thereof include acrylates.

In addition, CH ₂ ═C (CH ₃ ) COOCH ₂ CF ₃ (a-1) CH ₂ ═CHCOOCH ₂ CH ₂ C ₄ F ₉ (a-2) CH ₂ ═C (CH ₃ ) COOCH ₂ CH _{2 C 4 F 9 (a-} 3) CH 2 = CHCOOCH 2 CH 2 C 6 F 13 (a-4) CH 2 = C (CH 3) COOCH 2 CH 2 C 6 F 13 (a-5) CH 2 = _{CHCOOCH 2 CH 2 C 8 F 17} (a-6) CH 2 = C (CH 3) COOCH 2 CH 2 C 8 F 17 (a-7) CH 2 = CHCOOCH 2 CH 2 C 10 F 21 (a-8) _{CH 2 = C (CH 3)} COOCH 2 CH 2 C 10 F 21 (a-9) CH 2 = CHCOOCH 2 (CF 2) 2 H (a-10) CH 2 = C (CH 3) COOCH 2 (CF 2 _{) 2 H (a-11)} CH 2 = CHCOOCH 2 (CF 2) 4 H (a-12) CH 2 = C (CH 3) COOCH 2 (CF 2) 4 H (a-13) CH 2 = CHCOOCH 2 (CF _{2 ) 10 H (a-14)} CH 2 = C (CH 3) COOCH 2 (CF 2) 10 H (a-15) CH 2 = CHCOOCH 2 CH 2 CH (OH) CH 2 C 6 F 13 (a-16 _{) CH 2 = CHCOOCH (CH 2} OH) CH 2 C 6 F 13 (a-17) CH 2 = CHCOOCH ( meth) acrylates having ₂ CF ₃ (a-18) fluoroalkyl group and the like.

Among them, from the viewpoint of decreasing the refractive index, (meth) acrylate having a fluoroalkyl group having 3 or more carbon atoms (for example, 3 to 10 carbon atoms) is particularly preferable. In addition, from the viewpoint of the strength of the cured product, neopentyl glycol di (meth) acrylate, trimethylolpropane trichloride
(Meth) acrylate, pentaerythritol tri (meth)
Examples thereof include polyfunctional monomers having two or more (meth) acryloyl groups in the molecule such as acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate and butanediol di (meth) acrylate. The amount of the (meth) acrylate having no urethane group is 0 to 7 of the polyurethane (meth) acrylate.
It may be 0% by weight, for example 0 to 30% by weight.

The resin composition of the present invention may contain a coupling agent in order to improve the adhesion to a substrate such as a core. Examples of coupling agents are dimethyldimethoxysilane, methyltrimethoxysilane, vinyltrimethoxysilane,
Methacryloxypropyltrimethoxysilane, vinyldimethylmethoxysilane and the like can be mentioned. The amount of the coupling agent is usually 0 to 10% by weight, preferably 0.1 to 5% by weight, based on the resin composition.

An optical fiber can be produced by applying the resin composition of the present invention to an optical fiber core and curing it to form a clad layer. Quartz, glass, plastic, or the like is used for the optical fiber core, and quartz is particularly preferable from the viewpoint of light transmission loss. The diameter of the optical fiber of the present invention may be, for example, 0.05 to 2 mm. The thickness of the clad may be, for example, 1 to 100 μm.

Polymerization by heat and / or light is preferable as a method for curing the resin composition. Above all, curing by ultraviolet rays is particularly preferable from the viewpoint of productivity. Therefore, the resin composition of the present invention may further contain a photopolymerization initiator. Known photopolymerization initiators are used,
Among them, benzyl, benzoin ethyl ether, benzophenone, benzyl dimethyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy- 2-Methylpropan-1-one and 2,2-dimethoxy-2-phenylacetophenone are preferred. The amount of the photopolymerization initiator may be usually 0 to 10% by weight of the resin composition, preferably 0.1 to 5% by weight.

[0024]

EXAMPLES The present invention will be described in detail below with reference to examples. The present invention is not limited to the examples below. Hereinafter, parts are parts by weight. Synthesis Example 1 3.2 parts of 2,3-dihydroxypropyl methacrylate 1
H, 1H, 2H, 3H, 3H-perfluoroundeca-1,
2-diol 39.5 parts, dibutyltin dilaurate 0.
5 parts and 0.1 parts of methoxyhydroquinone were dissolved in 200 ml of isopropyl ether and dissolved at the reflux temperature of 1,3-
After adding 17.4 parts of bis (isocyanatomethyl) cyclohexane and reacting for 5 hours, the solvent was distilled off to obtain polyurethane methacrylate (average molecular weight: 5000). The IR chart of the obtained polyurethane methacrylate is shown in FIG.

Synthetic Example 2 Polyurethane methacrylate (average molecular weight: 1) was prepared in the same manner as in Synthetic Example 1 except that 16.8 parts of hexamethylene diisocyanate was used instead of 1,3-bis (isocyanatomethyl) cyclohexane. 4500) was obtained. Synthetic Example 3 A polyurethane acrylate (average molecular weight: 6200) was prepared in the same manner as in Synthetic Example 1 except that 2.9 parts of 2,3-dihydroxypropyl acrylate was used instead of 2,3-dihydroxypropyl methacrylate. Obtained. Synthesis Example 4 1H, 1H, 2H, 3H, 3H-perfluoroundeca-
3,3,4,5,5,6,6-instead of 1,2-diol
A reaction was performed in the same manner as in Synthesis Example 2 except that 23.2 parts of octafluorooctane-1,8-diol was used to obtain polyurethane methacrylate (average molecular weight: 2700).

Synthesis Example 5 1H, 1H, 2H, 3H, 3H-perfluoroundeca
Reaction was performed in the same manner as in Synthesis Example 2 except that 17.0 parts of 2,2-bis (trifluoromethyl) propane-1,3-diol was used instead of 1,2-diol, and polyurethane methacrylate (average molecular weight: 4300) was obtained. Synthetic Example 6 A polyurethane acrylate (average molecular weight: was prepared by carrying out the same reaction as in Synthetic Example 1 except that 2.9 parts of 1-hydroxymethyl-2-hydroxyethyl acrylate was used instead of 2,3-dihydroxypropyl methacrylate. 720
0) was obtained.

Synthesis Example 7 4.8 parts of 2,3-dihydroxypropyl methacrylate, the following formula:

[Chemical 7] 140 parts of polyether diol and 0.5 part of dibutyl tin dilaurate are added to 400 m of isopropyl ether.
1-Bis (isocyanatomethyl) cyclohexane (19.4 parts) was added dropwise at the reflux temperature and reacted for 5 hours, and then the solvent was distilled off to obtain polyurethane methacrylate (average molecular weight: 10,000). Obtained.

Synthesis Example 8 4.5 parts of 1,4-butanediol and 22.2 parts of isophorone diisocyanate were charged and reacted at 75 to 80 ° C. for 5 hours. Next, fluorinated acrylic ester [(a-16) / (a
-17) (Weight ratio) = 1: 1] 44.8 parts of the mixture was charged and dissolved by stirring at 75 to 80 ° C for 1 hour, 0.036 parts of dibutyltin dilaurate was added, and 6 at 75 to 80 ° C.
The reaction was carried out for a time to obtain a urethane acrylate oligomer (average molecular weight: 1500).

Examples 1 to 8 and Comparative Example 1 Immediately after drawing a quartz glass rod to an outer diameter of 200 μm, a resin composition having the composition shown in Table 1 was applied and cured by ultraviolet rays to give a plastic clad having an outer diameter of 230 μm. I got an optical fiber. Composition of these resin compositions, 2 after curing
Table 1 shows the refractive index at a wavelength of 589 nm at 3 ° C. and the numerical aperture (NA) of the plastic-clad optical fibers obtained from these resin compositions.

[0030]

[Table 1]

[0031]

EFFECT OF THE INVENTION Since the resin composition of the present invention has a low refractive index, the plastic clad optical fiber of the present invention using this resin composition for the clad has a larger NA than the conventional one, and can efficiently take in light from the light source. You can Therefore, when the same light source element is used, the present optical fiber can perform transmission over a longer distance than the case of using the conventional optical fiber, and is suitable as an optical fiber for an optical communication system and a light guide.

[Brief description of drawings]

1 shows an IR spectrum of the polyurethane acrylate obtained in Synthesis Example 1.

Claims (5)

[Claims] 1. A polyol having a (meth) acrylic group.
(I) and a polyol having a fluoroalkyl group (I
Polyurethane (meth) acrylates obtained by reacting I) with polyisocyanates. 2. The polyol (I) has the general formula (1): CH ₂ ═CXCOOCH ₂ CH (OH) CH ₂ OH (1) [wherein, X represents a hydrogen atom or a methyl group. ] And / or general formula (2): [In the formula, X is a hydrogen atom or a methyl group. ] The polyurethane (meth) acrylate of Claim 1 which is a diol shown by these. 3. The polyol (II) has the general formula (3): [In the formula, n is an integer of 1 to 20, k is an integer of 1 to 3, and l is 0.
Alternatively, 1 and m are integers of 1 to 12. The fluoroalkyl group may be linear or branched. ], General formula
_{(4): HO (CH 2} ) i (CF 2) j (CH 2) i OH (4) [ wherein, i is an integer of 0 to 2, j is an integer of from 1 to 10. ] And / or general formula (5): [In the formula, R ¹ and R ² are perfluoroalkyl groups having 1 to 10 carbon atoms and may be the same or different. ] The polyurethane (meth) acrylate of Claim 1 which is a diol shown by these. 4. A resin composition containing the polyurethane (meth) acrylate according to claim 1. 5. A plastic clad optical fiber using a cured product of the resin composition according to claim 4 as a clad material.