JPH059043A - Curable resin composition and optical fiber coated with the same - Google Patents

Abstract

PURPOSE:To increase the mechanical strength by curing a composition including a fluoropolymer, a fluorine-based curable monomer having a fluorinated alkyl group and a polyfunctional monomer incorporating a (meth)acryloyl group. CONSTITUTION:The fluoropolymer (1) is produced by polymerizing a fluorine- based curable monomer represented by formula I (Rf' is a fluorinated alkyl of >=C5, R is H, methyl or F) as an essential component. The composition is prepared by mixing (1) with e a fluorine-based curable monomer (2) represented by formula II (Rf is a fluorinated alkyl of 1-20C), and a (meth)acryloyl group containing polyfunctional monomer (3), (4) represented by formula III and/or formula IV, a thiol group-containing compound, as necessary a polymerization initiator and various additives in a specified weight ratio. The composition is applied to an optical core material, and energy such as heat, light and radiation rays is imparted thereto and the optical fiber superior in the transparency, mechanical strength and environmental resistance is obtained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a curable composition for optical fibers and optical fiber clad materials, and more specifically,
The present invention relates to an optical fiber having excellent mechanical strength, durability and optical properties, and a curable composition suitable for producing the optical fiber with high productivity.

[0002]

2. Description of the Related Art A plastic clad optical fiber whose core is made of quartz, silica, glass or the like and whose sheath is made of plastic (hereinafter referred to as PCF)
Is used as an optical fiber for medium-to-short distance transmission and a light guide because it is relatively inexpensive, has excellent translucency, and has a high numerical aperture. Conventionally, a silicone resin has been used as a clad material, but from the viewpoint of handling workability and environment resistance, a fluororesin having a high hardness has recently been proposed and implemented as a clad material.

For example, US Pat. No. 4,511,209, US Pat. No. 4,707,076, European Patent Publication No. 257863, JP-A No. 62-199.
643, JP-A-62-250047, USP 4,7
86,658, JP-A-63-154714, JP-A-64-11116, British Publication No. 2199332, JP-A-64-14221, and JP-A-1-22310.
Each publication such as No. 7 describes an active energy ray curable optical fiber clad resin mainly composed of fluorinated acrylate and an optical fiber shaped by using the same.

[0004]

However, the above-mentioned US Pat. No. 4,511,209 and US Pat.
707,076 and European Publication No. 25
The curable optical fiber clad resin composed only of low molecular weight curable monomers described in Japanese Patent No. 7863, etc. has poor compatibility or homogeneity at room temperature and is used as it is for production of optical fibers at room temperature. Then, the optical characteristics such as the optical transmission property of the optical fiber are extremely poor, and the adhesion of the clad layer to the core is poor, so that the clad layer is easily peeled off, and the environment resistance and the tensile strength of the optical fiber are reduced. Bad,
There is a problem that it cannot be used as an optical fiber at all. In addition, if the cladding resin is heated and used for the purpose of improving compatibility and homogeneity, strict temperature control is required to prevent problems such as eccentricity, and the drawing device becomes complicated and the work There was a problem that productivity and productivity deteriorate. Furthermore, when the clad resin is made transparent at room temperature by a conventionally known method, the mechanical strength of the clad layer becomes poor in view of composition and the refractive index increases, so that the target numerical aperture cannot be maintained. There was a problem.

On the other hand, in the case of containing a fluorine-containing polymer in the curable optical fiber clad resin described in British Publication No. 2199332, etc., compatibility with the core is improved, although coating workability is improved. There is a problem that the fluorine-based curable monomer and the non-fluorine-based curable monomer that can be used together are limited from the viewpoint of transparency and the like. For this reason, when it is attempted to improve the transparency, there is a problem that the mechanical strength becomes poor and the refractive index rises, so that the target numerical aperture cannot be maintained.

As described above, the workability during production of the optical fiber is excellent, the transparency is good even at room temperature, the transparency and the mechanical strength are excellent even after curing, and the mechanical strength and the optical strength are excellent even in the optical fiber. The current situation is that there is no low-refractive-index clad resin capable of exhibiting specific characteristics and environment resistance such as heat resistance and humidity resistance.

[0007]

The inventors of the present invention have made diligent studies to solve the above-mentioned problems, and as a result, some fluorine-containing polymer, a fluorinated curable monomer containing a fluorinated alkyl group, Further, it has been found that these problems can be solved by using a curable clad resin containing a polyfunctional monomer at the same time, and the present invention has been completed.

That is, the present invention provides a fluoropolymer (I), which comprises a fluorinated curable monomer (1) containing a fluorinated alkyl group having 5 or less carbon atoms, and a fluorinated alkyl group. A curable composition comprising a fluorine-based curable monomer (II) contained therein, and a polyfunctional monomer (III) containing two or more (meth) acryloyl groups in the molecule, and the same. The present invention provides an optical fiber obtained by applying the above to an optical fiber substrate and curing the same. Here, the optical fiber base means an optical fiber core material made of quartz, silica, glass, plastic, or the like, or an optical fiber.

The fluorinated curable monomer is a compound containing a polymerizable ethylenic group, and from the viewpoint of availability of raw materials and mechanical strength and optical characteristics as a clad material,
Those containing the following acrylic ester group and its related group are suitable.

Examples of the fluorinated curable monomer (1) containing a fluorinated alkyl group having 5 or less carbon atoms include fluorinated (meth) acrylates represented by the following general formula (A). .

Rf′OCO (R) = CH ₂ (A) (In the formula, Rf ′ is a fluorinated alkyl group having 5 or less carbon atoms, and an oxygen atom intervenes in a straight chain, a branched chain, or a main chain. Such as (CF ₃ ) ₂ CF0C (CF ₃ ) FCF ₂
-May be any, and R is H, a methyl group or F. In the present invention, compounds containing an acryloyl group, a methacryloyl group and an α-fluorinated acryloyl group are collectively referred to as (meth) acrylate.

The following compounds may be mentioned as specific examples of the fluorinated (meth) acrylate (A). a-1: CH ₂ = CHCOOCH ₂ CF ₃ a-2: CH ₂ = CHCOOCH ₂ CF ₂ CF ₃ a-3: CH ₂ = CHCOOCH ₂ CFHCF ₃ a-4: CH ₂ = C (CH ₃ ) COOCH ₂ CFHCF ₃ a-5: CH ₂ = CHCOOCH ₂ CH ₂ CF ₃ a-6: CH ₂ = CHCOOCH ₂ CF ₂ CFHCF ₃ a-7: CH ₂ = CHCOOCH ₂ CF (CF ₃ ) CF ₃ a-8: CH ₂ = CHCOOCH (CF ₃ ) ₂ a-9: CH ₂ = C (F) COOCH (CF ₃ ) ₂ a-10: CH ₂ = C (CH ₃ ) COOCH (CF ₃ ) ₂ a-11: CH ₂ = CHCOOCH ₂ (CF ₂ CF ₂ ) ₂ H a-12: CH ₂ = C (F) COOCH ₂ (CF ₂ CF ₂ ) ₂ H a-13: CH ₂ = C (CH ₃ ) COOCH ₂ (CF ₂ CF ₂ ) ₂ H a-14: CH ₂ = CHCOOCH ₂ CF ₂ CF ₂ CFHCF ₃ a-15: CH ₂ = CHCOOCH ₂ CF ₂ CF ₂ H a-16: CH ₂ = C (CH ₃ ) C00CH ₂ CF ₂ CF ₂ H a _{-17: CH 2 = C (F} ) C00CH 2 CF 2 CF 2 H fluorinated (meth) acrylate - DOO (a) may be a mixture of different structures two or more compounds. Needless to say, the present invention is not limited to the above specific examples.

From the viewpoint of transparency, mechanical strength, solvent resistance, etc. after curing of the curable resin composition according to the present invention, and the optical characteristics of optical fibers manufactured using the resin, especially PCF, From the viewpoint of mechanical strength and solvent resistance, fluorinated (meth) acrylate (A) is a-8, a-1.
1, a-15 are particularly preferable.

As the monomer constituting the fluoropolymer (I), in addition to the above-mentioned fluorinated (meth) acrylate (A), a fluorinated (meth) acrylate (B) described later can be used. The fluorinated (meth) acrylate containing a fluorinated alkyl group having 6 or more carbon atoms and / or the non-fluorinated (meth) acrylate may be contained, but the fluorinated curable monomer (II ) And a polyfunctional monomer (III)
From the viewpoints of compatibility with and the transparency after curing, the copolymerization ratio of the monomer (II) and / or the polyfunctional monomer (III) is the same as that of the fluorine-based curable monomer (1). Quantum (I
When the total of I) and polyfunctional monomer (III) is 100%, 30% by weight or less is preferable, and 0% is most preferable.

The non-fluorine-based (meth) acrylate is not limited in any way. For example, the ester moiety substituent has 1 or more carbon atoms, specifically n-propyl (meth) acrylate. , I-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate
G, hexyl (meth) acrylate, octyl (meth)
Acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate
, Stearyl (meth) acrylate, and aliphatic group ester (meth) acrylates such as isostearyl (meth) acrylate, glycerol (meth) acrylate
, 2-hydroxy (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, glycidyl (meth) acrylate, allyl (meth) acrylate, butoxybutoxyethyl (meth) acrylate -G
Butoxyethyl glycol (meth) acrylate,
N, N-diethylaminoethyl (meth) acrylate,
N, N-dimethylaminoethyl (meth) acrylate,
2-Ethylhexyl (meth) acrylate, γ-methacryloxypropyltrimethoxysilane, 2-methoxyethyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) Acrylate, nonylphenoxy polyethylene glycol (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, polyethylene glycol
Polypropylene glycol (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate
And dicyclopentenyl (meth) acrylate, isobornyl (meth) acrylate, phenyl (meth) acrylate, adamantyl (meth) acrylate, dimethyladamantyl (meth) acrylate and the like.
Needless to say, the present invention is not limited to these specific examples.

Examples of the fluorinated curable monomer (II) containing a fluorinated alkyl group include fluorinated (meth) acrylates represented by the following general formula (B). RfOCO (R) = CH ₂ (B) (In the formula, Rf is a fluorinated alkyl group having 1 to 20 carbon atoms, and may be linear or branched, R is H,
It is a methyl group or F. As the fluorinated (meth) acrylate (B), not only the above-mentioned fluorinated (meth) acrylate (A) but also the following compounds may be mentioned.

B-1: CH ₂ = CHCOOCH ₂ CH ₂ C ₈ F ₁₇ b-2: CH ₂ = C (CH ₃ ) COOCH ₂ CH ₂ C ₈ F ₁₇ b-3: CH ₂ = CHCOOCH ₂ CH ₂ C ₁₂ F ₂₅ b-4: CH ₂ = C (CH ₃ ) COOCH ₂ CH ₂ C ₁₂ F ₂₅ b-5: CH ₂ = CHCOOCH ₂ CH ₂ C ₁₀ F ₂₁ b-6: CH ₂ = C (CH ₃ ) COOCH ₂ CH ₂ C ₁₀ F ₂₁ b-7: CH ₂ = CH COOCH ₂ CH ₂ C ₆ F ₁₃ b-8: CH ₂ = C (CH ₃ ) COOCH ₂ CH ₂ C ₆ F ₁₃ b-9: CH ₂ = CHCOOCH ₂ CH ₂ C ₄ F ₉ b-10: CH ₂ = C (F) COOCH ₂ CH ₂ C ₆ F ₁₃ b-11: CH ₂ = CHCOOCH ₂ (CH ₂ ) ₆ CF (CF ₃ ) ₂ b-12 : CH ₂ = CHCOOCH ₂ (CF ₂ ) ₆ H b-13: CH ₂ = CHCOOCH ₂ (CF ₂ ) ₈ H b-14: CH ₂ = C (CH ₃ ) COOCH ₂ (CF ₂ ) ₈ H b-15 : CH ₂ = CHCOOCH ₂ (CF ₂ ) ₁₀ H b-16: CH ₂ = CHCOOCH ₂ (CF ₂ ) ₁₂ H b-17: CH ₂ = CHCOOCH ₂ C (OH) HCH ₂ C ₈ F ₁₇ b-18: CH ₂ = CHCOOCH ₂ CH ₂ N (C ₃ H ₇ ) SO ₂ C ₈ F ₁₇ b-19: CH ₂ = CHCOOCH ₂ CH ₂ N (C ₂ H ₅ ) COC ₇ F ₁₅ b-20: CH ₂ = CHCOO _{(CH 2) 2 (CF 2} ) 8 CF (CF 3) 2 b-21: CH 2 = C (CH 2 CH 2 C 8 F 17) COOCH 2 CH 2 C 8 F 17 fluorinated (meth) acrylate - DOO (B) is a mixture of two or more compounds having different structures It may be a thing. Needless to say, the present invention is not limited to the above specific examples.

The fluorinated (meth) acrylate (B) is preferably a fluorinated (meth) acrylate having a fluorinated alkyl group having 6 or more carbon atoms. Compatibility of the curable resin composition according to the present invention at room temperature, improvement of homogeneity, and stability thereof, and workability and productivity in production of optical fibers using the curable resin composition, particularly PCF. From the viewpoint of the optical characteristics and mechanical strength of the produced PCF and other optical fibers, b-1, b-7, b-12, b are used as the fluorinated (meth) acrylate (B).
-13 and b-15 are particularly preferable.

As described above, the compatibility and the transparency are good at room temperature, the workability is low in the production of the optical fiber due to the low refractive index, and the mechanical strength, the optical characteristic and the solvent resistance of the optical fiber are excellent. In order to obtain a clad resin capable of exhibiting the above, it is essential to mix the fluoropolymer (I) with the fluorinated curable monomer (II) containing a fluorinated alkyl group. The weight mixing ratio of (I) and (II) is 50/50 to 0.1 / 99.9, preferably 20/80 to 0.1 / 99.9, when the total is 100. is there. When the fluoropolymer is present within the former range, the curable resin composition has extremely good compatibility at room temperature, transparency, and stability, mechanical strength, and optical characteristics, which are excellent in optical fiber production. Workability and efficiency are improved, and mechanical strength, optical characteristics, and environmental resistance such as solvent resistance are remarkably improved in optical fibers.

As the polyfunctional monomer (III), a polyfunctional (meth) acrylate is used from the viewpoint of availability of raw materials and curability.
(C) is suitable. The polyfunctional (meth) acrylate (C) according to the present invention is generally referred to in the art as a polyfunctional (meth) acrylate or a special acrylate, and a prepolymer, a base resin, an oligomer, or an acrylic oligomer. The following are specifically exemplified. (I) A polyvalent (meth) acrylate in which two or more (meth) acrylic acids are bonded to a polyhydric alcohol. (Ii) The polyester polyol obtained by the reaction of a polyhydric alcohol and a polybasic acid is a polyester acrylate in which two or more (meth) acrylic acids are bonded.

Examples of the polyhydric alcohol in the above (i) and (ii) include ethylene glycol, 1,4-butanediol,
1,6-hexanediol, diethylene glycol, neopentyl glycol, trimethylolpropane, dipropylene glycol, polyethylene glycol, polypropylene glycol, pentaerythritol, dipentaerythritol and the like. Examples of the polybasic acid include phthalic acid, adipic acid, maleic acid, trimellitic acid, itaconic acid, succinic acid, terephthalic acid and alkenylsuccinic acid. (Iii) An epoxy-modified (meth) acrylate in which the epoxy group of the epoxy resin is esterified with (meth) acrylic acid to form a (meth) acryloyl group as a functional group.

The epoxy resin is bisphenol A.
-Epiculhydrin type, phenol novolac-epichlorohydrin type, polyhydric alcohol epichlorohydrin type alicyclic resin, and the like. (Iv) A polyurethane acrylate obtained by reacting a polyvalent isocyanate compound with a hydroxyl group-containing (meth) acrylate. Examples of the polyvalent isocyanate compound include those having a structure of polyester, polyether, polyurethane or the like in the central part of the molecule and having isocyanate groups at both ends. (V) Other examples include polyether (meth) acrylate, melamine (meth) acrylate, alkyd (meth) acrylate, isocyanurate (meth) acrylate, and silicon (meth) acrylate.

As examples of these more specific compounds,
The following may be mentioned. c-1 ethylene glycol di (meth) acrylate c-2 diethylene glycol di (meth) acrylate c-3 triethylene glycol di (meth) acrylate c-4 polyethylene glycol di (meth) acrylate (number average molecular weight 150 to 1000) c- 5 Propylene glycol di (meth) acrylate c-6 Dipropylene glycol di (meth) acrylate c-7 Tripropylene glycol di (meth) acrylate c-8 Polypropylene glycol di (meth) acrylate (number average molecular weight 200 to 1000) c- 9 neopentyl glycol di (meth) acrylate c-10 1,3-butanediol di (meth) acrylate c-11 1,4-butanediol di (meth) acrylate c-12 1,6-hexanediol di (meth) acrylate Acrylate c-13 hydroxypivalic acid Sterneopentyl glycol di (meth) acrylate c-14 bisphenol A di (meth) acrylate c-15 trimethylolpropane tri (meth) acrylate c-16 pentaerythritol tri (meth) acrylate c-17 dipentaerythritol hexa (meth) Acrylate c-18 pentaerythritol tetra (meth) acrylate c-19 trimethylolpropane di (meth) acrylate c-20 dipentaerythritol monohydroxypenta (meth) acrylate Further specific examples other than the above include Neomer MA-305 (c −
21), Neomer BA-60 (c-22), Neomer TA-505 (c
-23), Neomar TA-401 (c-24), Neomar PHA405X
(C-25), Neomer TA705X (c-26), Neomer EA40
0X (c-27), Neomer EE401X (c-28), Neomer EP
405X (c-29), Neomer HB601X (c-30), Neomer
HB605X (c-31) [above Sanyo Chemical Co., Ltd.], KAYARAD HY-2
20 (c-32), HX-620 (c-33), D-310 (c-34),
D-320 (c-35), D-330 (c-36), DPHA (c-37), D
PCA-20 (c-38), DPCA-30 (c-39), DPCA-60 (c
-40), DPCA-120 (c-41) [Nippon Kayaku Co., Ltd.], FA
-713A [Hitachi Chemical Products] (c-42).

The polyfunctional (meth) acrylate may be a mixture of two or more kinds of compounds having different structures. still,
Needless to say, the present invention is not limited to the above specific examples.

According to the knowledge of the present inventors, the fluorine-containing polymer (I) and the fluorine-based curable monomer (II), that is, the fluorinated (meth) acrylate (A) and (B). C-9 and / or c-15 from the viewpoint of the compatibility of the above and the optical characteristics and mechanical strength of the curable resin composition according to the present invention after curing.
Are preferred, and among them, c-15 is particularly preferred.

Further, for the purpose of lowering the refractive index, it is also possible to use a fluorine-based polyfunctional monomer represented by the following general formula as the polyfunctional (meth) acrylate. _{CH 2 = C (R) COO} (CH 2) X (CF 2) Y (CH 2) X 00CC (R) = CH 2 ( wherein, X represents 1 to 2, Y is an integer of 4-12, R is the same as above.) Specific examples of these compounds include the following.

C-43 CH ₂ = CHCOOCH ₂ (C ₂ F ₄ ) ₂ CH ₂ OCOCH = CH ₂ c-44 CH ₂ = CHCOOC ₂ H ₄ (C ₂ F ₄ ) ₃ C ₂ H ₄ OCOCH = CH ₂ c −45 CH ₂ = C (CH ₃ ) COOC ₂ H ₄ (C ₂ F ₄ ) ₃ C ₂ H ₄ OCOC (CH ₃ ) = CH ₂ c −46 CH ₂ = C (F) COOC ₂ H ₄ (C ₂ F ₄ ) ₆ C ₂ H ₄ OCOC (F) = CH ₂ c−47 CH ₂ = CHCOOC ₂ H ₄ (C (CF ₃ ) FCF ₂ ) ₄ C ₂ H ₄ OCOCH = CH ₂ c−48 CH ₂ = CHCOOC ₂ H ₄ (C ₂ H ₄ ) _a (C (CF ₃ ) FCF ₂ ) _b C ₂ H ₄ OCOCH = CH ₂ CH ₂ = C (R ₁ ) COOCH ₂ C (OH) HCH ₂ OR _f `` OCH ₂ C (OH) HCH ₂ OCOC (R ₁ ) = CH ₂ (wherein Rf ″ is (CH ₂ ) _X (CF ₂ ) _Y (CH ₂ ) _X (however, X,
Y is the same as above. ). ), And as a specific example of these

[0028]

[Chemical 1]

[0029]

[Chemical 2]

[0030]

[Chemical 3]

[0031]

[Chemical 4]

It is ] The compound represented by these is mentioned. The proportion of the polyfunctional monomer (III) in the curable resin composition according to the present invention is not particularly limited, but from the viewpoint of optical properties or mechanical strength, the fluoropolymer (I), the fluorine-based curable composition When the total of the monomer (II) and the polyfunctional monomer (III) is 100%, the weight ratio is 50% to 1%.

Further, the curable resin composition according to the present invention may contain the non-fluorinated (meth) acrylate as a diluting monomer from the viewpoint of optical characteristics or mechanical strength. .

The fluoropolymer (I) according to the present invention is
Polymerization methods known in the art, such as radical polymerization and anionic polymerization.
Initiate polymerization of heat, light, electron beam, radiation, etc.
Manufactured as energy, but industrially heat and / or
Radical polymerization using light or light as the polymerization initiation energy is preferred.
Good These polymerization forms include bulk polymerization and solution weight.
, Or emulsion polymerization, etc.
I can. When heat is used as the polymerization initiation energy,
No catalyst, azobisisobutyronitrile, benzoi
Rupa-oxide, t-butylpa-oxy-2-ethyl
Xanoate, t-butylperoxybenzoate, t
-Butyl per-oxyisopropyl carbonate, methyl
Heavy metals such as octyl ketone peroxide-cobalt naphthenate
If you use light such as synthetic initiators or ultraviolet rays,
So-called photopolymerization initiators known in the art (for example, VI described later)
-1 to 11) and, if necessary, an amine compound
Substance or a photosensitizer such as a phosphorus compound is added to prevent polymerization.
It can be accelerated. Also, these radical weights
In addition, if necessary, lauryl mercaptan, thiol
Octyl Glycolate, γ-mercaptopropyl trime
Toxysilane, C₁₈F ₁₇CH₂CH₂Mercapto such as SH
Fluorine-containing polymerization when used in combination with a group-containing chain transfer agent
The degree of polymerization of body (I) can be adjusted. Electron beam
When polymerizing by radiation, especially when adding a polymerization initiator, etc.
No need to join. In addition, solution-polymerized fluoropolymer
When obtaining (I), the solvent adversely affects the polymerization reaction.
If you don't, there is no limit.

In the curable resin composition according to the present invention,
Fluorinated (meth) acrylates (A) and (B) which are constituent monomers of the fluoropolymer (I), non-fluorinated (meth)
The acrylates are fluorine-based curable monomers (I
I) or a diluting monomer, the polymerization of the fluoropolymer (I) is carried out by reacting the unreacted fluorinated (meth) acrylate.
(A), (B) and non-fluorinated (meth) acrylate are stopped at the stage where they remain, and after that, a predetermined amount of polyfunctional monomer (III) is added and mixed, whereby the present invention The curable resin composition can be easily obtained.

In the curable resin composition according to the present invention,
To improve environment resistance such as heat resistance and moisture resistance after curing, and to improve environment resistance such as heat resistance and moisture resistance of optical fibers,
Introduction of an antioxidant (V) such as a thiol group-containing compound or a hindered phenol-based compound is extremely important. Among these, thiol group-containing compounds are preferable from the viewpoint of curability of the resin and environmental resistance.

The thiol group-containing compound has 2 carbon atoms.
To 18 alkylthiol compounds, thioglycolic acid esters containing alkyl groups having 2 to 18 carbon atoms, monofunctional thiol compounds such as C ₈ F ₁₇ CH ₂ CH ₂ SH, and 2 in the molecule Examples thereof include polyfunctional thiol compounds containing the above thiol groups, such as neopentylthioglycol, trithiomethylolpropane, and thiodicarboxylic acid esters such as dilaurylthiodipropionic acid. Among these, optical fibers, especially P
In CF, γ-mercaptopropyltrimethoxysilane, which simultaneously contains a coupling group in the molecule, is particularly preferable as it exhibits excellent heat resistance, environment resistance such as humidity resistance.

As the hindered phenol type compound,
For example, 2,6-di-t-butyl-4-methylpheno-
2,2'-methylenebis (4-methyl-6-t-butylphenol), 4,4'-thiobis (6-t-butyl-3-methylphenol), 4,4'-butylidene-
Bis (3-methyl-6-t-butylphenol), 1,
3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene,
1,3,5-tris (2-methyl-4-hydroxy-5)
-T-butylphenol) butane, octadecyl-3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate, lithoethylene glycol-bis [3-
(3-t-Butyl-5-methyl-4-hydroxyphenyl) propionate] and 1,6-hexanediol-bis-3- (3,5-di-t-butyl-4-hydroxyphenyl) propione -To], 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], pentaerythyl-
And tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate].

These thiol group-containing compounds and hinders
The dophenol compounds may be used alone or in combination of two or more. The ratio of the thiol compound and the antioxidant in the curable resin composition according to the present invention is 100% of the total amount of the fluoropolymer (I), the monomer (II) and the polyfunctional monomer (III). The weight ratio is 0.01% to 5%, and 0.01% to 3% is preferable from the viewpoint of optical properties and mechanical strength after curing.

The curable resin composition according to the present invention comprises the above-mentioned fluoropolymer (I), fluorine-based curable monomer (II),
In addition to the polyfunctional monomer (III), the photopolymerization initiator (IV), and the antioxidant (V), it is possible to contain various additives (VI) if necessary.

As the additive (VI), a polymer or solvent for adjusting viscosity, a light resistance stabilizer, a colorant, a coupling agent or an optical fiber core for improving adhesion to the optical fiber core or substrate. Or a defoaming agent, a leveling agent, and a surfactant for uniformly applying to a substrate, a surface modifier for controlling the adhesion between an optical fiber and a primary coating agent, and a refractory agent and a plasticizer. Etc.

Examples of the coupling agent include silane-based, titanium-based, and zirco-aluminate-based agents, among which dimethyldimethoxysilane, dimethyldiethoxysilane, methyltrimethoxysilane, dimethylvinylmethoxysilane, and phenyl. Trimethoxysilane, γ-
Chloropropyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-methacryloxypropylmethoxysilane, γ
-Methacryloxypropylmethyldimethoxysilane, γ
-Acryloxypropylmethyltrimethoxysilane, γ
Silane systems such as -acryloxypropylmethyldimethoxysilane and γ-mercaptopropyltrimethoxysilane already mentioned as thiol group-containing compounds are particularly preferred.

The antifoaming agent, leveling agent, surfactant and surface modifier are preferably fluorine-based ones. As the antioxidant, a phosphorus compound or a disulfide group-containing compound may be used in addition to the above compounds.

Examples of the flame retardant include brominated flame retardants, zinc compounds, antimony compounds, phosphorus compounds,
Or the thing which used these 2 or more types together is mentioned. Brominated flame retardants include decabromodiphenyl oxide, hexabromobenzene, hexbromocyclododecane, dodecachloropentacyclooctadeca 7,15 diene, tetrabromobisphenol A, tribromophenol, tetrabromophthalic anhydride, dibromoneopentyl glycol. , 2- (2,4,6-tribromophenoxy) ethyl (meth) acrylate and the like.

As the zinc compound, for example, 3ZnO-2B ₂ O _3-
Boric acid such as 3H ₂ O, 2ZnO-3B ₂ O ₃ -3, 5H ₂ O, zinc compounds, ZnO-
ZnMoO ₄ , CbO-ZnMoO _{4 and} other molybdenum zinc compounds, Zn
₃ (PO ₄ ) ₂ -4H ₂ O, composite calcined product of ZnO and MgO, ZnO, ZnCO ₃
Etc. Examples of the antimonic acid compound include antimony trioxide and the like.

For the purpose of plasticizing the curable resin composition according to the present invention and adjusting the refractive index of the clad material obtained therefrom, a non-polymerizable fluorine compound such as HO is used as an additive other than the above. _{(CH 2) r C s F2} s + 1 (r is an integer from 1 to 4, s is an integer from 1 to 20.) such as fluorinated _{alcohol, HOOC (CH 2) t C} u F 2u + ₁ (t is 0 or 1-4
And u is an integer of 1 to 20. ) Fluorinated carboxylic acids such as), fluorinated polyethers commonly referred to as fluorinated oils, or N (C ₄ F ₉ ) ₃ , perfluorodecalin, C ₈ F ₁₇ OC ₄ F ₉ , C ₉ F ₂₀ A compound called a fluorine-based inert liquid can be used. The curable surgical composition according to the present invention is applied to or impregnated into a substrate, particularly an optical fiber core, and then polymerized and cured by irradiation with active energy rays such as light, electron beams and radiation, and a desired coating layer. Alternatively, a clad layer can be formed. In some cases, heat can also be used alone or in combination as an energy source.

When light such as ultraviolet rays is used as the active energy ray, a photopolymerization initiator (IV) known in the art,
For example, d-1: benzophenone, d-2: acetophenone, d-3: benzoin, d-4: benzoin ethyl ether, d-5: benzoin isobutyl ether, d-.
6: benzyl methyl ketal, d-7: azobisisobutyronitrile, d-8: hydroxycyclohexyl phenyl ketone, d-9: 2-hydroxy-2-methyl-1
-Phenylpropan-1-one or the like can be used as a catalyst. If necessary, a photosensitizer such as an amine compound or a phosphorus compound can be added to accelerate the polymerization. The suitable ratio of the photopolymerization initiator in the curable resin composition according to the present invention is 100 in total of the curable components.
%, 0.01 to 10% by weight, and more preferably 0.1 to 7% by weight. When polymerizing and curing with an electron beam or radiation, it is not necessary to add a polymerization initiator or the like.

When heat is used as a polymerization initiator, it is, for example, 80 to 80 in the presence of a catalyst or a polymerization initiator such as azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide-cobalt naphthenate. It can be polymerized and cured at 200 ° C.

According to the knowledge of the present inventors, from the viewpoint of workability, productivity, and economical efficiency in manufacturing an optical fiber, and the performance of the finished body, compared with curing by heat, ultraviolet rays are It is preferable to cure the resin composition by any of the following methods: electron beam, electron beam, or radiation. Among these, the method of polymerizing and curing with ultraviolet rays is the most simple and economical.

A solvent may be added to the curable resin composition according to the present invention for the purpose of controlling its viscosity, coatability and coating thickness. As a solvent,
There is no particular limitation as long as it does not adversely affect the polymerization reactivity, for example, alcohols such as methanol, ethanol and isopropyl alcohol, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, esters such as methyl acetate, ethyl acetate and butyl acetate. System, chloroform, chlorine such as dichloroethane, carbon tetrachloride, and benzotrifluoride, chlorobenzotrifluoride,
Low boiling point solvents such as m-xylene hexafluoride, tetrachlorodifluoroethane, 1,1,2-trichloro-1,2,2-trifluoroethane and trichloromonofluoromethane are preferable from the viewpoint of workability. When such a solvent is contained, a step of removing the solvent at room temperature or, if necessary, by heating or depressurizing is required before starting the polymerization and curing. When the solvent is removed by heating, it is necessary to control the temperature so as not to cause the heat polymerization of the monomer or the like.

As the method for applying the curable resin composition according to the present invention to a substrate, various methods known in the art, for example, brush coating, applicator, bar coater and roller are used. -A coating method using a brush or a roll coater, a spray coating method using an air-less spray coater, a flow coating method using a shower coater or a curtain float coater (flow coater). -Coating), a dipping method, a casting method, etc. can be used, and it is preferable to properly use them according to the material, shape, or application of the base material.

In particular, when the curable resin composition according to the present invention is applied to an optical fiber core or a base material and cured,
The curable resin composition according to the present invention is continuously applied to a coat die through which an optical fiber core or a base material can be continuously supplied, and after removing the solvent as necessary, active energy rays are irradiated to the cladding or For example, the method of forming the coated part,
DT 2,459,320, JP-A-53-139545
Methods known in the art, such as those described in Japanese Patent Publication No. 4,125,644 and the like, can be used.

When the curable resin composition of the present invention is polymerized and cured by irradiation with active energy rays, a sterilizing lamp, a fluorescent lamp for ultraviolet rays, a carbon arc, a xenon lamp, a high pressure mercury lamp for copying, which are known in the art, Medium or high pressure mercury lamp, ultra high pressure mercury lamp, electrodeless lamp. Metal halide lamps, ultraviolet rays using natural light as a light source, or electric wires using a scanning or caten type electron beam accelerator can be used. In the case of ultraviolet curing of a coating layer having a thickness of 5 μm or less, the efficiency of polymerization can be improved. In this respect, it is preferable to irradiate in an atmosphere of an inert gas such as nitrogen gas.

The optical fiber core material or substrate in the present invention may be an inorganic material such as quartz, silica or glass,
Examples include plastics such as polymethylmethacrylate, deuterated polymethylmethacrylate, polystyrene and polycarbonate. Among these, quartz, silica, and glass are particularly preferable from the characteristics of the curable resin composition according to the present invention.

The curable resin composition of the present invention is used not only for optical fiber clad materials and coating materials, but also for clad materials such as optical waveguide sheets, optical adhesives, and electrical insulation such as potting agents and sealing agents. It can also be used as a material and a coating material for electric wires, and based on its low refractive index, it is applied to the surface of a transparent plate or sheet such as glass or plastic to form a low reflection coating, It can also be used as a sealant for ICs.

Furthermore, the curable resin composition of the present invention comprises
Since it forms a cured film excellent in scratch resistance, oil resistance, smoothness, water and oil repellency, water resistance, moisture resistance, rust resistance, stain resistance, peelability, low water absorption, etc. It can also be used as a protective coating film for a substrate.

For example, non-magnetic metals such as copper, aluminum and zinc, polyesters such as polyethylene terephthalate and polyethylene-2,6-naphthalate, polyolefins such as polypropylene, cellulose acetate and the like. Ferromagnetic alloys (iron, cobalt and / or nickel) deposited on plastics such as cellulosics, polycarbonates, and optionally ceramics such as glass, paper, wood, fibers, porcelain and pottery. A main component, which contains a small amount of aluminum, silicon, chromium, manganese, molybdenum, titanium, various heavy metals, rare earth metals, etc.) or a magnetic material such as iron, cobalt, chromium, etc. in the presence of trace oxygen, and a plastic film such as polyester Magnetic tape deposited on the surface or protective coating of the magnetic layer of the magnetic disk, and anti-friction property Particularly required, magnetic tape - flop, floppy - also suitable as surface and back surface treating agent for a magnetic recording medium such as a disk.

On the other hand, since the curable resin composition of the present invention can form a transparent and smooth thin film on the glass surface,
It can also be used as an oil stain preventive agent or an oil permeation preventive agent for various optical devices in applications requiring oil resistance and wiping resistance.

Furthermore, it is also suitable as a protective coating for a solar cell protective film, an optical fiber, an optical fiber cable, an optical disk, a magneto-optical disk, etc., which is particularly required to have moisture resistance. Furthermore, since it is excellent in scratch resistance, antifouling property and moisture resistance, surface protection of medical devices and instruments, teeth, surface protection of dentures and tooth cavities, can also be used as a mold, and the curable resin composition of the present invention is Since it can form a film having excellent scratch resistance, it can be used as a hard coat agent for various molded products, films, sheets and the like.

Furthermore, the curable resin composition of the present invention can form a paint or ink excellent in antifouling property or non-tackiness by mixing a pigment and a dispersant. Therefore, it is also useful as a ship bottom paint.

[0061]

EXAMPLES Next, specific examples of the present invention will be described, but it goes without saying that the present invention is not limited to these examples. “Part” in the text is based on weight.

Hereinafter, all the abbreviations of compounds refer to the above compounds. The abbreviation A is an acrylate compound,
M represents a methacrylate compound and F represents an α-fluorinated acrylate compound. Synthesis Example 1 (Synthesis of a-15 Polymer) 500 ml equipped with cooling condenser-thermometer and stirrer
200 g of a-15 and 1 g of azobisisobutyronitrile were weighed in a four-necked round-bottomed flask, and stirred at 70 ° C. for 15 minutes in a nitrogen gas atmosphere. The bulky polymer which was viscous when hot was taken out of the system.

The reaction rate calculated from the gel fraction was 46%, and the molecular weight calculated from GPC was Mn of 110,000 in terms of styrene. The refractive index n _D ²⁵ was 1.383. Synthesis Examples 2 to 6 The molecular weights and refractive indexes of the fluoropolymers synthesized in the same manner as in Synthesis Example 1 are summarized in Table-1.

[0064]

[Table 1]

Synthesis Example 7 (synthesis of a-15 / isobornyl acrylate = 95/5 (%) copolymer) 500 equipped with cooling condenser, thermometer and stirrer
In a ml four-neck round bottom flask, a-15 (95 g), isobornyl acrylate (5 g), azobisisobutyronitonyl (0.3 g) and 1,1,1-trichloroethane (2) were added.
30 g was weighed and reacted at 80 ° C. for 10 hours in a nitrogen gas atmosphere. The solvent was distilled off under reduced pressure to obtain the desired copolymer. The molecular weight Mn measured by GPC was 170,000 and n _D ²⁵ = 1.379. Synthesis Example 8 In a 500 ml glass round bottom flask equipped with a stirrer,
400 g of a-8 and 0.7 g of photopolymerization initiator d-9 were weighed and reacted for 10 seconds while irradiating a high pressure mercury lamp of 80 w / cm 1 from the side. By this operation, a viscous liquid of 35,000 cps was obtained at 25 ° C. Molecular weight by GPC was 700,000, a refractive index n _D ^{2 5} is 1.368
Met. The reaction rate by the gel fraction method was 21%. Synthesis Examples 9 to 14 Viscosity of the fluoropolymer synthesized in the same manner as in Synthesis Example 8,
The refractive index and the reaction rate are summarized in Table 2.

[0066]

[Table 2]

The residual monomer composition in Synthesis Examples 1 to 14 was the same as the charged monomer composition in all cases. Examples 1 to 11 and Comparative Examples 1 to 4 Physical properties of compounding examples and comparative examples of the curable resin composition according to the present invention, and PCF when these are applied as a clad material.
The physical properties of are shown in Table 3.

The transparency of the curable resin composition was visually evaluated. For the transparency after curing, pour the curable resin composition into a glass container having a depth of 1 mm, cover it with a quartz plate having a heat of 1 mm to prevent bubbles from entering, and irradiate with a high pressure mercury lamp having an output of 120 w / cm. It was hardened and evaluated visually.

The refractive index can be obtained by measuring the 1 mm thick cured plate obtained as described above with an Abbe refractometer. The optical fiber (PCF) is a coating die capable of continuously supplying a curable resin composition to a core having an outer diameter of 200 μm obtained by melt spinning synthetic quartz at a drawing speed of 60 m / min (maintained at 25 ° C.).
Was continuously applied through the resin and cured under a nitrogen atmosphere by using two high pressure mercury lamps having an output of 120 w / cm to obtain a product. The thickness of the clad layer is 15 μm.

The transmission loss was measured by the cutback method at a wavelength of 850 nm. After heat resistance test means 1 at 130 ℃
It shows the transmission loss at 850 nm after holding the PCF for 000 hours.

After the humidity resistance test means 5 at 70 ° C. × 98% RH.
The transmission loss at 850 nm after holding the PCF for 00 hours is shown.

[0072]

[Table 3]

[0073]

[Table 4]

[0074]

[Table 5]

Example 12 Even when the curable resin composition according to the present invention was used as a clad material for an all-plastic optical fiber, good mechanical strength and optical characteristics, as well as good mechanical strength, were obtained as in the above examples. An optical fiber having environmental resistance was obtained.

[0076]

EFFECTS OF THE INVENTION The curable resin composition of the present invention has an appropriate coating viscosity, good transparency and homogeneity even at room temperature, and is excellent in transparency and mechanical strength after curing. It is far superior to the ones. Therefore, when the curable resin composition according to the present invention is used as a clad material or a covering material for an optical fiber, there is no problem of eccentricity, an optical fiber can be produced with good productivity, and excellent mechanical strength and optical characteristics are obtained. Further, it is possible to provide an optical fiber having environment resistance such as heat resistance and humidity resistance.

Claims (11)

[Claims] 1. A fluorine-containing polymer (I) obtained by polymerizing a fluorine-based curable monomer (1) containing a fluorinated alkyl group having 5 or less carbon atoms as an essential component, and fluorine containing a fluorinated alkyl group. A curable composition comprising a curable monomer (II) and a polyfunctional monomer (III) containing two or more (meth) acryloyl groups in the molecule. 2. The curable composition according to claim 1, wherein the fluorine-based curable monomer (1) is a fluorinated (meth) acrylate represented by the following general formula. Rf'OCOC (R) = CH ₂ (In the formula, Rf 'is a fluorinated alkyl group having 5 or less carbon atoms, and R is a hydrogen atom, a methyl group or a fluorine atom.) 3. The curable composition according to claim 1, wherein the fluorinated curable monomer (II) is a fluorinated (meth) acrylate represented by the following general formula. RfOCO (R) = CH ₂ (In the formula, Rf is a fluorinated alkyl group having 1 to 20 carbon atoms, and R is the same as above.) 4. A fluorinated (meth) acrylate having 5 or less carbon atoms is H (CF ₂ CF ₂ ) ₂ CH ₂ OCOC (R) = CH ₂ and / or HCF ₂ CF ₂ CH ₂ OCOC (R). = CH ₂ and / or (CF ₃ ) ₂ CH0COC (R) = CH ₂ (wherein R is a hydrogen atom, a methyl group or a fluorine atom). 5. The curable composition according to claim 1, wherein the fluorinated curable monomer (II) is a fluorinated (meth) acrylate having a fluorinated alkyl group having 6 or more carbon atoms. 6. The polyfunctional monomer (IV) is (CH ₃ ) ₂ C [CH ₂ OCOC (R) = CH ₂ ] ₂ and / or C ₂ H ₅ -C [CH ₂ OCOC (R) = CH. ₂ ] ₃ (wherein R is a hydrogen atom, a methyl group or a fluorine atom). 7. The multifunctional monomer (IV) is neopentyl glycol diacrylate and / or trimethylol.
The curable composition according to claim 6, which is lepropane triacrylate. 8. The curable composition according to claim 1, further comprising a thiol group-containing compound. 9. The curable composition according to claim 8, wherein the thiol group-containing compound is γ-mercaptopropyltrimethoxysilane. 10. An optical fiber obtained by applying the curable composition according to claim 1 to an optical fiber substrate and then curing the composition. 11. The optical fiber according to claim 10, wherein the optical fiber substrate is made of quartz, silica or glass.