JP3146592B2 - Method for producing optical fiber having hard coat film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a hard-coated optical fiber which is excellent in surface performance such as surface hardness and scratch resistance, and which is excellent in durability of a hard coat film.

[0002]

2. Description of the Related Art In general, an optical fiber comprises a core through which light passes, a cladding surrounding the core with a lower refractive index than the core, and a coating layer (protective layer) further surrounding the cladding. It is composed of

[0003] When connecting this optical fiber, a complicated manual operation of peeling off a coating layer of polyvinyl chloride, polyethylene or the like, inserting the same into a connector (coupler), and connecting is performed. It is very easy for the optical fiber to be damaged during such a connection operation. In particular, in the case of an optical fiber in which the cladding material is made of plastic, the cladding material has low surface hardness and abrasion resistance, and its layer is very thin. Light leakage is likely to occur. Therefore, damage during this operation has become a major problem as a cause of transmission loss.

[0004] In some applications, an optical fiber consisting of only a core and a clad without a coating layer is used. In this case, the clad is exposed and easily damaged because the clad is exposed. There was such a problem.

[0005] Japanese Patent Application Laid-Open No. Sho 62-12640 proposes that it is effective to provide a hard coat film on a clad in order to overcome such disadvantages.

[0006]

However, since the hard coat material proposed in this publication is an acrylic polymer, it has been difficult to increase the surface hardness and abrasion resistance of the optical fiber to a sufficient level. .

If the adhesion between the hard coat film and the clad is insufficient, the optical fiber is easily peeled off due to bending of the optical fiber. Therefore, it is also desired that the hard coat film has excellent durability.

Accordingly, the present invention solves the above-mentioned problems of an optical fiber having a plastic clad material and can improve the surface properties such as the surface hardness and abrasion resistance of the optical fiber and have excellent durability. It is a main object of the present invention to provide a method for producing a hard-coated optical fiber capable of forming a hard-coated film.

[0009]

In order to achieve this object, the present invention provides an optical fiber comprising a core and a plastic clad, comprising a liquid capable of dissolving or swelling the clad (hereinafter referred to as a clad dissolving and swelling component). After pre-coating with a primer agent, coating with an organopolysiloxane-based hard coat material is performed to produce an optical fiber having a hard coat film.

For example, when the clad is an optical fiber mainly composed of a polymer containing a vinylidene fluoride unit and / or a fluoroalkyl (meth) acrylate unit, an ether-based solvent, a ketone-based solvent, or an ester-type solvent is used as the clad-dissolving swelling component. One or more solvents selected from solvents, fluorine-based solvents and chlorine-based solvents are used, and the content thereof (solvent in the primer agent) is 50% by weight.
After pre-coating with the above primer,
An optical fiber having a hard coat film is manufactured by coating with an organopolysiloxane hard coat material.

The primer usually contains a non-volatile component such as a poly (meth) acrylate polymer in addition to the above-mentioned solvent.

In the optical fiber of the present invention, as long as the cladding material is made of plastic, the core material may be glass or plastic.

As the material of the plastic clad material,
Vinyl fluoride, vinylidene fluoride, ethylene trifluoride,
Ethylene tetrafluoride, propylene trifluoride, propylene hexafluoride, ethylene trifluoride chloride, hexafluoroacetone; ethyl trifluoride (meth) acrylate, propyl tetrafluoride (meth) acrylate, isopropyl hexafluoride (meth) Acrylate, pentyl octafluoride (meth) acrylate, isobutyl nonafluoride (meth) acrylate,
Fluoroalkyl (meth) acrylates such as dodecyl (meth) acrylate 17; α-fluoroacrylates such as methyl α-fluoroacrylate and ethyl trifluoride α-fluoroacrylate; perfluoro-2,2
A cyclic fluoroolefin such as -dimethyl-1,3-dioxole; or a polymer obtained by polymerizing one or two or more monomers having a low refractive index such as siloxanes such as dimethylsiloxane and propylmethyltrifluorosiloxane. However, other plastics may be used.

The above-mentioned fluorine-based polymer or silicone-based polymer is often used for the cladding material of an optical fiber, but the polymer of these cladding materials has poor adhesion to an organopolysiloxane-based hard coat material. Many.

Therefore, in order to overcome this problem, in the present invention, the surface of the clad is pre-coated with a primer having a specific composition, and then an organopolysiloxane hard coat is applied.

This primer is composed of a non-volatile (residual) component and a volatile (solvent) component.

As a non-volatile component of the primer, a polymer or the like containing a poly (meth) acrylate derivative as a main component is used. Specifically, (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate,
Propyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, lauryl ( (Meth) acrylate, dodecyl (meth)
Acrylate, stearyl (meth) acrylate, 2-
Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, methoxy oligoethylene glycol (meth) acrylate, glycidyl (meth) acrylate, (meth) acrylamide, N, N-
Dimethylaminoethyl (meth) acrylate, N, N-
Various (meth) acrylate derivatives such as diethylaminoethyl (meth) acrylate, or ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,3-propanediol di (meth) acrylate, 1,4-butanediol Di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth)
Acrylate, trimethylolpropane (di / tri)
One or more main components selected from various polyfunctional (meth) acrylate derivatives such as (meth) acrylate, pentaerythritol (di / tri / tetra) (meth) acrylate, and oligoethylene glycol di (meth) acrylate And the like.

The precoating is performed to enhance the adhesiveness between the organopolysiloxane-based hard coat material and the clad. The film formed by this precoating (primer film) has an improved adhesion to the clad. Goodness is also important.

In order to obtain good adhesion between the clad and the primer film, it is important to select a solvent as a solvent component in the primer, that is, to dissolve or swell the clad, preferably a liquid. It must be used as the main component of the solvent.

The term "liquid for dissolving the clad" as used herein means a liquid capable of dissolving 5% by weight or more of the clad material after 5 g of the clad material is immersed in 100 g of the liquid at room temperature for 7 days. The liquid that swells the clad is a liquid that can increase the clad material by 3% by weight or more after immersing 5 g of the clad material in 100 g of the liquid at room temperature for 7 days.

Further, if the solvent component in the primer agent remains for a long time after the precoating treatment, the clad dissolution and swelling component penetrates deep into the clad layer and adversely affects the light transmission of the optical fiber. There is also. Therefore, it is desirable that the solvent component of the primer be volatilized immediately after coating, and for that purpose, the material of the clad dissolution swelling component desirably has a boiling point of 150 ° C. or less.

When the clad material is mainly composed of a polymer containing vinylidene fluoride units and / or fluoroalkyl (meth) acrylate units, examples of the solvent for the clad dissolving and swelling component include tetrahydrofuran and diethyl ether. , Dioxane and the like; ether solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; Freon 113, Freon 112;
Fluorinated solvents such as trifluoromethyl-benzene, 1,3-bis-trifluoromethyl-benzene, hexafluoroisopropanol and hexafluoroacetone hydrate; methylene chloride, chloroform, carbon tetrachloride, trichloroethane, chlorobenzene, dichlorobenzene, etc. Can be exemplified.

Further, these solvents can be used as a mixed solvent of two or more kinds as necessary. It is preferable that the above-mentioned clad melting and swelling component accounts for 50% by weight or more, more preferably 70% by weight or more in the solvent for the primer agent, in order to sufficiently enhance the adhesiveness between the clad and the primer film.

As a method for applying the primer, a method used in a usual coating operation can be applied, for example, a dipping method, a flow coating method, a spin coating method, a brush coating method, a spray method, a roll method, a curtain flow method. Are preferred.

The primer thus applied is generally removed at room temperature or by heating and drying to form a primer film. The heating can be performed by hot air, infrared rays, or the like. The heating temperature should be determined by the heat resistance of the applied optical fiber and the primer composition to be used, but it is necessary that the heating temperature does not exceed the heat resistance of the cladding agent of the optical fiber. Is room temperature to 200 ° C., more preferably room temperature to 1
Performed at 50 ° C. At lower temperatures, drying tends to be insufficient. If the temperature is higher than this, the heat resistance of the cladding material of the optical fiber is often exceeded, and problems such as thermal decomposition of the primer film, generation of cracks, and yellowing are likely to occur.

The thickness of the primer film in the present invention is preferably between 0.1 and 200 μm from the viewpoint of maintaining the adhesive strength. Particularly preferably, it is 0.4 to 100 μm.

The organopolysiloxane component for forming the organopolysiloxane hard coat film in the present invention is, for example, an organosilicon compound represented by the following general formula (I) and a hydrolyzate thereof, and a compound represented by the following general formula (I): It is represented by at least one kind of organosilicon compound selected from the group consisting of the organosilicon compound represented by II) and a hydrolyzate thereof.

[0028]

Embedded image (Where R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ are organic groups having 1 to 10 carbon atoms. X and Q are hydrolyzable groups; a, c, and e are Each is 0 or 1, b,
d and f are 0, 1 or 2 respectively. Y is carbon number 2
~ 40 organic groups. First, the organosilicon compound represented by the general formula (I) and a hydrolyzate thereof will be described.

In the formula represented by the general formula (I), R ¹ and R ² are organic groups having 1 to 10 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a phenyl group and a vinyl group. Halogenated hydrocarbon groups such as hydrocarbon group, chloropropyl group and 3,3,3-trifluoropropyl group, and epoxy groups such as γ-glycidoxypropyl group and β- (3,4-epoxycyclohexyl) ethyl group Examples include a group-containing organic group, a (meth) acryl group-containing organic group such as a γ-methacryloxypropyl group and a γ-acryloxypropyl group, and other organic groups having various substituents such as a mercapto group, a cyano group, and an amino group. Can be R ¹ and R ² are the same,
It may be heterogeneous.

X is not particularly limited as long as it is a functional group capable of being hydrolyzed, in other words, as long as it forms a silanol group by a hydrolysis reaction. Specific examples thereof include a methoxy group, an ethoxy group and a methoxyethoxy group. Such as an alkoxy group, an acyloxy group such as an acetoxy group,
Examples include a halogeno group such as a chloro group and a bromo group, and an aryloxy group such as a phenoxy group.

When (a + b) is 2 or more, R ¹
And at least one of R ² is preferably a reactive organic group such as an epoxy group-containing organic group or a (meth) acryloxy group-containing organic group from the viewpoint of improving surface hardness.

Specific representative examples of these organosilicon compounds include methyltrimethoxysilane, methyltriethoxysilane, methyltrimethoxyethoxysilane, methyltriacetoxysilane, methyltripropoxysilane, methyltributoxysilane, and ethyltrimethoxysilane. Methoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrimethoxyethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltriacetoxysilane, γ-chloropropyltrimethoxy Silane, γ-chloropropyltriethoxysilane, γ-chloropropyltriacetoxysilane,
3,3,3-trifluoropropyltrimethoxysilane,
γ-methacryloxypropyltrimethoxysilane, γ-
Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltrimethoxyethoxysilane, γ-mercaptopropyltriethoxysilane, N-β- (aminoethyl) -γ- Aminopropyltrimethoxysilane, β-cyanoethyltriethoxysilane, methyltriphenoxysilane, chloromethyltrimethoxysilane, chloromethyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, α-glycid Xylethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, β-glycidoxyethyltrimethoxysilane,
β-glycidoxyethyltriethoxysilane, α-glycidoxypropyltrimethoxysilane, α-glycidoxypropyltriethoxysilane, β-glycidoxypropyltrimethoxysilane, β-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltripropoxysilane, γ-glycidoxypropyltributoxysilane, γ
-Glycidoxypropyltrimethoxyethoxysilane,
γ-glycidoxypropyltriphenoxysilane, α-
Glycidoxybutyltrimethoxysilane, α-glycidoxybutyltriethoxysilane, β-glycidoxybutyltrimethoxysilane, β-glycidoxybutyltriethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ- Glycidoxybutyltriethoxysilane, δ
-Glycidoxybutyltrimethoxysilane, δ-glycidoxybutyltriethoxysilane, (3,4-epoxycyclohexyl) methyltrimethoxysilane, (3,4
-Epoxycyclohexyl) methyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyl Tripropoxysilane, β
-(3,4-epoxycyclohexyl) ethyltributoxysilane, β- (3,4-epoxycyclohexyl)
Ethyltrimethoxyethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriphenoxysilane,
γ- (3,4-epoxycyclohexyl) propyltrimethoxysilane, γ- (3,4-epoxycyclohexyl) propyltriethoxysilane, δ- (3,4-epoxycyclohexyl) butyltrimethoxysilane, δ-
Trialkoxysilanes such as (3,4-epoxycyclohexyl) butyltriethoxysilane, trialcyloxysilanes or triphenoxysilanes or hydrolysates thereof, and dimethyldimethoxysilane, phenylmethyldimethoxysilane, dimethyldiethoxysilane, phenylmethyldisilane Ethoxysilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, dimethyldiacetoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-mercaptopropylmethyldimethoxy Silane, γ-mercaptopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, methyl Ruvinyldimethoxysilane, methylvinyldiethoxysilane, glycidoxymethylmethyldimethoxysilane, glycidoxymethylmethyldiethoxysilane, α-glycidoxyethylmethyldimethoxysilane, α-glycidoxyethylmethyldiethoxysilane, β -Glycidoxyethylmethyldimethoxysilane,
β-glycidoxyethylmethyldiethoxysilane, α-
Glycidoxypropylmethyldimethoxysilane, α-glycidoxypropylmethyldiethoxysilane, β-glycidoxypropylmethyldimethoxysilane, β-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, γ-glycidoxypropylmethyldibutoxysilane, γ-glycidoxypropylmethyldimethoxyethoxysilane, γ-glycidoxypropyl Methyl diphenoxysilane, γ-glycidoxypropylmethyldiacetoxysilane, γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, γ-glycidoxypropylvinyldimethoxy Dialkoxysilanes such as orchid, γ-glycidoxypropylvinyldiethoxysilane, γ-glycidoxypropylphenyldimethoxysilane, γ-glycidoxypropylphenyldiethoxysilane, diphenoxysilane or diacyloxysilanes or a hydrolyzate thereof Decomposition products are an example.

Next, the organosilicon compound represented by the general formula (II) and its hydrolyzate will be described.

In the general formula (II), R ³ , R ⁴ ,
As R ⁵ and R ⁶ , R ¹ and R in the above general formula (I)
The same example as in No. ² can be mentioned. Examples of Q include the same examples as those of X.

Y is an organic group having 2 to 40 carbon atoms. That is, Y is a functional group contained in the molecule by two Si atoms and a Si-C bond, and in the functional group,
There is no problem even if hetero atoms other than carbon and hydrogen such as oxygen atoms and nitrogen atoms are contained. Further, within the range of 2 to 40 carbon atoms, the organic group may be in the form of a chain or a ring, and there is no problem even if an oxygen atom or the like is present as an epoxy ring or the like. Or, it is preferable in that it contributes as a functional group at the time of curing.

As a specific example,

Embedded image And the like.

Among the organosilicon compounds represented by the general formula (I) or (II), the use of organosilicon compounds containing an epoxy group or a glycidoxy group is particularly preferred for the purpose of imparting flexibility. It is. For the purpose of imparting weather resistance and water resistance, it is preferable to use organosilicon compounds containing a vinyl group, a methyl group, a phenyl group and the like. X and Q are preferably an alkoxy group having 1 to 4 carbon atoms or an alkoxyalkoxy group in terms of curing speed, ease of hydrolysis, and the like.

Among these organosilicon compounds, a hydrolyzate is preferable in order to lower the curing temperature and promote the curing.

The hydrolysis may be carried out by adding pure water or an acidic aqueous solution such as hydrochloric acid, acetic acid or sulfuric acid, followed by stirring. The degree of hydrolysis may be controlled by adjusting the amount of pure water or acidic aqueous solution to be added. In the hydrolysis, it is particularly preferable to add pure water or an acidic aqueous solution in an amount equal to or more than 3 moles of X and Q in the general formula (I) or (II) in view of accelerating curing. At the time of hydrolysis, alcohol and the like are generated, so it is possible to carry out hydrolysis without a solvent, but after mixing an organic silicon compound and a solvent for the purpose of performing hydrolysis more uniformly, hydrolysis is performed. It is also possible. Depending on the purpose, the alcohol or the like after the hydrolysis can be used after removing an appropriate amount under heating and / or reduced pressure, and then a suitable solvent can be added.

Examples of these solvents include alcohols, esters, ethers, ketones, halogenated hydrocarbons, aromatic hydrocarbons such as toluene and xylene, and solvents such as N, N-dimethylformamide. In addition, these solvents can be used as a mixed solvent of two or more kinds as necessary. Further, depending on the purpose, it is possible to promote the hydrolysis reaction and to heat the mixture to room temperature or higher in order to further promote the reaction such as precondensation, or to lower the hydrolysis temperature to room temperature or lower to suppress the precondensation. It is also possible.

Further, in order to improve the hardness of the hard coat film, it is preferable to use a particulate inorganic oxide in combination. Such a particulate inorganic oxide is not particularly limited as long as it does not impair transparency in the state of a coating film and achieves its purpose, but workability, particularly preferred examples from the viewpoint of imparting transparency include And a sol dispersed in a colloidal form. More specific examples include magnesium fluoride sol, silica sol, titanium oxide sol, cerium oxide sol, zirconia sol, antimony oxide sol, and alumina sol. The addition amount of the particulate inorganic oxide is
In order to show the effect more remarkably, 5% by weight
Preferably, it is contained in an amount of at least 80% by weight. That is, if the content is less than 5% by weight, no obvious effect of the addition is observed. If the content is more than 80% by weight, adverse effects such as poor adhesion to the substrate, generation of cracks in the coating itself, and reduced impact resistance are likely to occur.

As the particulate inorganic oxide, those having an average particle diameter of 1 to 200 μm are usually used, but those having a particle diameter of 5 to 100 μm are preferably used. When the average particle diameter exceeds 200 mμ, the transparency of the resulting coating film is lowered, the turbidity becomes large, and it becomes difficult to increase the film thickness. Those having a particle size of less than 1 μm have poor stability and poor reproducibility. There is no problem even if various surfactants or amines are added to improve the dispersibility of the fine particles. Furthermore, there is no problem in using two or more kinds of fine particle inorganic oxides in combination.

Further, in the coating composition for forming the organopolysiloxane-based hard coat film, various surfactants can be used for the purpose of improving the flow at the time of application. Among them, a block or graft copolymer of dimethylpolysiloxane and alkylene oxide, and a fluorine-based surfactant are effective.

It is also possible to add an ultraviolet absorber for the purpose of further improving the weather resistance, and an antioxidant as a method for improving heat deterioration.

Further, various inorganic compounds and the like can be added to these coating compositions as long as the film performance is not significantly reduced. The combined use of these additives can further improve various physical properties such as adhesion to a substrate, chemical resistance, surface hardness, durability, and dyeability. Preferred examples of the inorganic material that can be added include metal alkoxides represented by the following general formula (III), and various chelate compounds and / or hydrolysates thereof.

M (OQ) _m (III) (where Q is an alkyl group, an acyl group, or an alkoxyalkyl group. M is the same value as the number of charges of the metal M. M
Is silicon, titanium, zircon, antimony, tantalum,
Germanium, aluminum and the like. When the organopolysiloxane-based hard coat film of the present invention is formed, various curing agents can be used in combination for the purpose of accelerating curing, curing at low temperature, and the like. As the curing agent, a general curing agent used for curing various epoxy resins or various organic silicon resins may be used.

Specific examples of these curing agents include various organic acids and their acid anhydrides, nitrogen-containing organic compounds, various metal complex compounds or metal alkoxides, organic carboxylate salts of alkali metals, and carbonates. Examples include various salts such as salts, and radical polymerization initiators such as peroxides and azobisisobutyronitrile. These curing agents can be used as a mixture of two or more kinds.

Among these curing agents, an aluminum chelate compound represented by the following general formula (IV) is particularly preferred from the viewpoints of stability of the coating composition, prevention of coloring of the coated film after coating, and the like.

[0049] _{Al Y r Z (3-r} ) ··· (IV) ( In the formula, Y is OL (L is a lower alkyl group), Z
Is a ligand derived from a compound represented by the general formula M ¹ COCH ₂ COM ² (M ¹ and M ² are both lower alkyl groups), and a general formula M ³ COCH ₂ COOM ⁴ (M ³ , M
⁴ is at least one selected from ligands derived from the compounds represented by lower alkyl groups), and r is 0, 1 or 2. Among the aluminum chelate compounds represented by the above general formula (IV), aluminum acetylacetonate, aluminum bisethylacetoacetate monoamine from the viewpoint of solubility in a composition, stability, effect as a curing catalyst, and the like. Acetyl acetonate, aluminum di-n-butoxide-monoethyl acetoacetate, aluminum di-iso-propoxide-monomethyl acetoacetate, and the like are particularly preferred. These can be used as a mixture of two or more kinds.

As a coating method, a method used in a usual coating operation can be applied, and examples thereof include a dipping method, a flow coating method, a spin coating method, a brush coating method, a spray method, a roll method, and a curtain flow method. preferable.

The coating composition thus applied is generally cured by heating and drying. As a heating method, hot air, infrared rays or the like can be used.
Also, the heating temperature should be determined by the heat resistance of the applied optical fiber and the coating composition used, but it is necessary that the heating temperature does not exceed the heat resistance of the cladding agent of the optical fiber, Usually from room temperature to 200
C., more preferably 35-150.degree. At lower temperatures, curing or drying tends to be insufficient,
If the temperature is higher than this, the heat resistance of the clad material of the optical fiber is often exceeded, and problems such as thermal decomposition, crack generation, and yellowing of the hard coat film are likely to occur.

The thickness of the organopolysiloxane-based hard coat film in the present invention is preferably in the range of 0.1 to 200 μm from the viewpoint of maintaining the adhesive strength, hardness and surface gloss. Particularly preferably, it is 0.4 to 100 μm.

Furthermore, in order to further improve the adhesiveness and wettability between the optical fiber clad surface and the primer film or between the primer film and the hard coat film, the primer film is treated on the clad surface or after the primer treatment. The surface may be subjected to various chemical and physical treatments. For example, the chemical treatment includes hot water immersion, oxidation-reduction treatment, acid or alkali treatment, and the physical treatment is preferably plasma treatment, corona discharge treatment, ultraviolet irradiation, or the like.

The optical fiber having the organopolysiloxane-based hard coat film of the present invention is preferably protected by further providing a coating layer of a vinyl chloride resin, a polyethylene resin, an epoxy resin, or the like.

Further, the form of the optical fiber may be a normal single core shape, a multi-core shape in which a large number of optical fibers are fused between cladding layers, or a film shape having a wide core portion.

[0056]

In the present invention, the hard coat film is an organopolysiloxane-based hard coat material;
Before forming the hard coat film, it is important to pre-coat the optical fiber with a primer containing a specific solvent.

That is, by pre-coating with a primer containing a liquid that dissolves or swells the clad, even if the clad material is a material having poor adhesion, such as a fluoropolymer, the primer film can be formed on the clad with good adhesion. Thus, the adhesion durability of the organopolysiloxane-based hard coat film can be improved.

Further, since the hard coat film is an organopolysiloxane-based hard coat material, surface properties such as surface hardness and friction resistance can be sufficiently improved.

[0059]

Embodiments will be described below with reference to embodiments.

Example 1 (1) Preparation of Primer 10 g of polymethyl methacrylate [“Acrypet VH” (manufactured by Mitsubishi Rayon Co., Ltd.)] was dissolved in 290 g of an equal mixture of ethyl acetate and butyl acetate. This was used as a primer.

(2) Preparation of Hard Coating Agent 176 g of γ-glycidoxypropyltrimethoxysilane
While stirring and controlling the liquid temperature to 10 ° C.
40.3 g of a 5 N hydrochloric acid aqueous solution was dropped and mixed to obtain a hydrolyzate. To 51.8 g of this hydrolyzate, 18.3 g of ethanol, 183 g of n-propanol, 1.5 g of aluminum acetylacetonate and a silicone-based surfactant (“SR manufactured by Tore Dow Corning Silicone Co., Ltd.”
X-294A ″) was added, and the mixture was stirred until it became uniform to obtain a hard coat agent.

(3) Coating and curing The primer prepared in the above (1) was coated on an optical fiber having a cladding material of vinylidene fluoride / ethylene tetrafluoride copolymer (copolymerization ratio: 80/20% by weight). It was applied by a dipping method. The coated optical fiber was subjected to a heat treatment with a 60 ° C. hot air drier for 1 hour. Next, the hard coat agent prepared in the above item (2) was applied to the primer-treated optical fiber by a dipping method. The coated optical fiber was heated and cured with a hot air dryer at 80 ° C. for 2 hours.

(4) Test Results The performance of the optical fiber having the obtained hard coat film was evaluated according to the following test method. Table 1 shows the results.
As shown in Table 2, both the appearance, the scratch resistance and the durability were excellent.

(A) Appearance The quality of the appearance was evaluated by observing its transparency, coloring properties and the presence or absence of cracks with the naked eye.

(B) Scratch resistance of coating film The surface was rubbed with # 0000 steel wool to determine the degree of scratching. The criteria were as follows.

Good: Slight scratches occur when strongly rubbed.

Poor: Scratches occur even if rubbed lightly.

(C) Durability of Coating After the optical fiber is repeatedly bent and stretched at 20 mmφ and 90 ° for 50 times, the presence or absence of peeling of the coating is visually observed to judge the durability of the coating. did.

Example 2 (1) Preparation of Primer 10 g of polymethyl methacrylate [“Acrypet VH” (manufactured by Mitsubishi Rayon Co., Ltd.)] was dissolved in 290 g of hexafluoroisopropanol, and this was used as a primer.

(2) Preparation of Hard Coating Agent (A) Acetic acid 1 was added to 263.7 g of vinyltrimethoxysilane.
9.8 g was added, and while maintaining the liquid temperature at 10 ° C. with stirring,
74.7 g of 0.05 N hydrochloric acid was added dropwise to obtain a hydrolyzate of vinyltrimethoxysilane.

(B) Methyltrimethoxysilane 378.
28.8 g of acetic acid was added to 0 g, and 149.4 g of 0.01 N hydrochloric acid was added dropwise while maintaining the liquid temperature at 10 ° C. with stirring to obtain a methyltriethoxysilane hydrolyzate.

(C) 352.6 g of the hydrolyzate of vinyltriethoxysilane obtained in (a) and 547.g of the hydrolyzate of methyltrimethoxysilane obtained in (b).
And 2 g of sodium acetate, 80 g of xylene, 20 g of butyl acetate and a silicone surfactant [“SRX-298” (Tore Dow Corning.
(Manufactured by Silicone Co., Ltd.)] and stirred until uniform, to obtain a hard coat agent.

(3) Coating and curing The primer prepared in the above (1) was applied by dipping to an optical fiber having a fluoroalkyl methacrylate copolymer as a cladding material. 60 coated optical fibers
It heat-processed for 1 hour with the hot air dryer of ° C. Next, the hard coat agent prepared in the above (2) was applied to the primer-treated optical fiber by a dipping method. The coated optical fiber was heated and cured with a hot air dryer at 80 ° C. for 2 hours.

(4) Test Results A performance test of the optical fiber having the obtained coating film was performed in the same manner as in Example 1. As shown in Table 1, the results were excellent in appearance, scratch resistance and durability.

Comparative Example 1 The same test as in Example 1 was performed on the optical fiber used in Example 1 without any coating. As shown in Table 1, the results were inferior in abrasion resistance.

Comparative Example 2 Primer treatment and hardening were performed in the same manner as in Example 1 except that 290 g of toluene was used instead of 290 g of an equal mixture of ethyl acetate and butyl acetate as a solvent for the primer. Coating was performed to obtain an optical fiber having a hard coat film. As shown in Table 1, the test results performed in the same manner as in Example 1 showed that although the appearance and the scratch resistance were excellent, the durability was poor.

Comparative Example 3 An optical fiber having a hard coat film was obtained in the same manner as in Example 2, except that the hard coat agent was applied without performing the primer treatment. As shown in Table 1, the test results performed in the same manner as in Example 1 showed that although the appearance and the scratch resistance were excellent, the durability was poor.

[0078]

[Table 1]

[0079]

According to the present invention, when a hard coat film is formed on the surface of a plastic clad material of an optical fiber, the surface properties of the optical fiber, such as surface hardness and scratch resistance, can be greatly improved. In addition, since the hard coat film and the clad have excellent peeling resistance, a hard coat coated optical fiber having excellent durability can be obtained.

Accordingly, in the coated optical fiber obtained, surface damage and peeling of the coating during operations such as a connection operation are greatly reduced, and handling and durability during the operation are greatly improved.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-112104 (JP, A) JP-A-2-25812 (JP, A) JP-A-3-261901 (JP, A) JP-A-4-112 104210 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C03C 25/24 G02B 6/00 386 G02B 6/44 301

Claims (3)

(57) [Claims] An optical fiber comprising a core and a plastic clad is pre-coated with a primer containing a liquid capable of dissolving or swelling the clad.
A method for producing an optical fiber having a hard coat film, wherein the optical fiber is coated with an organopolysiloxane hard coat material. 2. The plastic clad in the optical fiber is mainly composed of a polymer containing vinylidene fluoride units and / or fluoroalkyl (meth) acrylate units, and at least 50% by weight of a solvent in the primer agent. Is a liquid capable of dissolving or swelling the clad, and the liquid is one or more selected from ether solvents, ketone solvents, ester solvents, fluorine solvents, and chlorine solvents. The method for producing an optical fiber having a hard coat film according to claim 1, wherein the optical fiber is a solvent. 3. The method according to claim 1, wherein the primer comprises a polymer mainly composed of a poly (meth) acrylate polymer and a solvent mainly composed of a liquid capable of dissolving or swelling the clad. Item 2. A method for producing an optical fiber having a hard coat film according to item 1.