KR20120092944A - The photocurable coating composion for an optical fiber and the optical fiber - Google Patents

Abstract

PURPOSE: A photocurable coating composition for optical fibers and optical fibers are provided to improve adhesiveness towards glass under high temperature and high moisture condition by including caprolactone silanol. CONSTITUTION: A photocurable coating composition for optical fibers comprises 30-90 weight% of photopolymerization type urethane acrylate oligomer, 1-40 weight% of reactive monomer, 1-5 weight% of photoinitiator, 0.5-1.5 weight% of other additives and 0.5-20 weight% of carprolactone silanol. The reactive monomer comprises one or more acrylate groups, methacrylate group or vinyl group. The carprolactone silanol is synthesized from tri-hydroxy caprolactone and isocyanurated silane. The adhesiveness towards the glass of the photocurable coating composition for the optical fibers at high temperature and high moisture(85 deg. Celsius, 95%RH) is bigger than the adhesiveness at the room temperature(23 deg. Celsius, 50%RH). The optical fiber comprises a glass core, a coating layer and coating.

Description

PHOTOCURABLE COATING COMPOSION FOR AN OPTICAL FIBER AND THE OPTICAL FIBER}

The present invention relates to a photocurable coating composition for optical fibers and an optical fiber.

In order to improve the water resistance performance of the optical fiber coating, for example, the optical fiber coating must have a strong adhesion to the material even after high temperature immersion.

Conventional ultraviolet curable optical fiber coating agent was applied to the oligomer synthesized from the crystalline polyol to improve the water resistance. However, these crystalline polyols have the problem of causing low temperature crystallization of the coating at low temperatures.

In order to reduce the freezing point of the coating agent in order to reduce the crystallinity and light loss rate generated at low temperatures, it has been reported that by applying an oligomer synthesized by controlling the ratio of the crystalline polyol and the amorphous polyol appropriately, a stable optical fiber coating agent can be made at low temperature. (US Pat. No. 6,599,956). In addition, when 50 to 70% by weight of a photocurable urethane oligomer using a polyester-based polyol has been reported that there is no water penetration into the film and the optical fiber at 60 ℃ high temperature water (EP Patent No. 1362016).

However, the method described above has limitations in the amount of application of oligomers to the composition, and may also limit the use of reactive and non-reactive silane and sulfur based additives that enhance adhesion to glass.

Moreover, even if the adhesive force in the state of normal temperature and normal humidity is maintained suitably, there exists a problem that adhesive force falls in the state of high temperature and high humidity.

It is an object of the present invention to provide a photocurable coating composition for an optical fiber that has better adhesion to glass than at room temperature and at high humidity.

It is another object of the present invention to provide an optical fiber in which the strip strength of the coating is superior to that of the normal temperature and the normal humidity in the state of high temperature and high humidity.

The photocurable coating composition for optical fibers of the present invention comprises (A) a photopolymerizable urethane acrylate oligomer, (B) a reactive monomer comprising at least one acrylate group, methacrylate group or vinyl group, (C) photoinitiator (D) other additives And (E) Caprolactone silanol, the content ratio of which is (A) 30 to 90% by weight of the photopolymerized urethane acrylate oligomer, (B) one or more acrylate groups, methacrylate groups Or 1 to 40% by weight of a reactive monomer containing a vinyl group, (C) 1 to 5% by weight of photoinitiator, (D) 0.5 to 1.5% by weight of other additives, (E) 0.5 to 20% by weight of caprolactone silanol It may be included as.

Here, (E) caprolactone silanol may be synthesized from tri-hydroxy caprolactone and isocyanurated silane (Isocyanurated Silane), (E) caprolactone silanol is tri It is preferable that the hydroxyl group caprolactone and the isocyanurated silane were synthesized in a molar ratio of 1 to 3: 1.

The caprolactone silanol (E) thus synthesized may be at least one selected from compounds of Formulas 1 to 3.

[Formula 1]

[Formula 2]

(3)

In addition, the photopolymerizable acrylate oligomer (A) may preferably include Ethoxylated Polypropylene glycol having a weight average molecular weight of 2,000 to 5,000.

In the photocurable coating composition for optical fibers of the present invention, as a result of the adhesion test on the glass, the adhesive force (B ₁ ) at high temperature and high humidity conditions (85 ° C., 95% RH) is at room temperature and humidity conditions (23 ° C., 50% RH). It is characterized in that it is larger than the adhesive force (B ₀ ) of, more preferably the adhesive force (B ₁ ) at high temperature and high humidity conditions (85 ℃, 95% RH) is the normal temperature and humidity conditions (23 ℃, 50% RH) 1.1 times or more than the adhesive force (B ₀ ) at is good.

In addition, it is preferable that the glass transition temperature (Tg) of the photocurable coating composition for optical fibers of the present invention is -60 degrees or less, and in particular, the elastic modulus at -60 degrees of the photocurable coating composition for optical fibers is 300 MPa. It is preferable that it is the following.

Such a photocurable coating composition for an optical fiber of the present invention may be used as an inner primary coating composition or an outer primary coating composition as a coating layer for an optical fiber.

The optical fiber of the present invention comprises a glass core and a coating layer and coating obtained by curing the photocurable coating composition on the glass core, wherein the coating layer comprises a unit structure derived from caprolactone silanol, It is preferable that the photocurable coating composition to form is the photocurable coating composition for optical fibers of this invention mentioned above.

In particular, the optical fiber of the present invention is more than the high-temperature and high-humidity conditions (85 ℃, 95% RH) coating the strip strength (S ₀₎ from the coated strip strength (S ₁₎ is at room temperature and normal humidity condition (23 ℃, 50% RH) in It is big.

The present invention provides a photocurable coating composition for an optical fiber that has better adhesion to glass than at room temperature and at high humidity under conditions of high temperature and high humidity.

In addition, the present invention provides an optical fiber in which the strip strength of the coating is better than that at the normal temperature and the normal humidity in the state of high temperature and high humidity.

The photocurable coating composition for optical fibers of the present invention comprises (A) a photopolymerizable urethane acrylate oligomer, (B) a reactive monomer comprising at least one acrylate group, methacrylate group or vinyl group, (C) photoinitiator (D) other additives And (E) Caprolactone silanol, the content ratio of which is (A) 30 to 90% by weight of the photopolymerized urethane acrylate oligomer, (B) one or more acrylate groups, methacrylate groups Or 1 to 40% by weight of a reactive monomer containing a vinyl group, (C) 1 to 5% by weight of photoinitiator, (D) 0.5 to 1.5% by weight of other additives, (E) 0.5 to 20% by weight of caprolactone silanol It may be included as.

That is, the present invention is characterized by including (E) caprolactone silanol in order to improve the adhesion to the glass in the high temperature and high humidity state than the adhesion to the glass in room temperature and normal humidity.

Here, (E) caprolactone silanol may be synthesized from trihydroxy caprolactone (Tri-Hydroxy caprolactone) and isocyanurated silane (Isocyanurated Silane). The caprolactone polyol selected to obtain caprolactone silanol needs to be trihydroxy caprolactone, which, in the case of mono-hydroxy, enhances adhesion to glass at high temperatures and high humidity as presented herein. This is because characteristics are hardly expressed, and in the case of tetra-hydroxy, there is a possibility that problems may occur in the compatibility or moisture properties of the composition.

In addition, the caprolactone silanol (E) is preferably a trihydroxy group caprolactone and isocyanurated silane synthesized in a molar ratio of 1 to 3: 1, which must be synthesized in a molar ratio of at least 1: 1. This is because it is possible to eliminate isocyanurated silanes which do not participate in and to synthesize a molar ratio of up to 3: 1 or less, thereby better controlling adhesion enhancement to glass at high temperature and high humidity.

The caprolactone silanol (E) thus synthesized may be at least one selected from compounds of Formulas 1 to 3.

[Formula 1]

[Formula 2]

(3)

In the present invention, the (A) photopolymerizable acrylate oligomer, (B) at least one acrylate group, methacrylate group or a reactive monomer containing a vinyl group, (C) photoinitiator and (D) other additives are common optical fiber General photopolymerizable acrylate oligomers used in the flame coating composition can be used.

(A) photopolymerization type acrylate oligomer

The photopolymerized acrylate oligomer (A) used in the present invention is (i) polyol copolymer, (ii) polyisocyanate, (iii) acrylate alcohol, (iv) urethane reaction catalyst and (v) Synthesized from a composition comprising a polymerization inhibitor, preferably consisting of a polyester polyol and a polyether polyol in a 10:90 to 30:70 weight ratio and may have a molecular weight in the range of 5,000 to 30,000. The photopolymerized urethane acrylate oligomer is used in an amount of 30 to 90% by weight of the total weight of the coating composition. If it is less than 30% by weight, there is a problem of loss due to micro-venting and steam generation due to heat of ultraviolet energy during the process due to an increase in curing shrinkage of the resin composition. It becomes bad.

The components constituting the oligomer (A) are as follows.

(i) polyol copolymer

The polyol copolymer used in the present invention has a molecular weight of 1,000 to 10,000, and preferably includes a repeating unit of -CH ₂ CH ₂ O- or -CH ₂ CH (CH ₂ CH ₃ ) O-. Preferred examples of the polyol copolymer include polyester polyol, polyether polyol, polycarbonate polyol, polycaprolactone polyol, ring-opening tetrahydrofuran propylene oxide air Tetrahydrofuran propylene oxide ring opening copolymer, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,5-pentanediol , 1,6-hexanediol (1,6-hexandiol), neopentyl glycol (neopentyl glycol), 1,4-cyclohexane dimethanol (1,4-cyclohexane dimethanol) and bisphenol-A (bisphenol-A) type It is preferable to use at least one from the group consisting of diols. More preferably, 70 to 90% by weight of the polyether polyol or ethoxylate polypropylene oxide copolymer and 10 to 30% by weight of the polyester polyol may be used in combination.

In addition, the polyol copolymer is preferably used in an amount of 45 to 85% by weight of the photopolymerizable urethane acrylate oligomer weight.

(ii) polyisocyanates

The polyisocyanate used in the present invention is preferably 2,4-tolyene diisocyanate, 2,6-tolyene diisocyanate, 1,3-xylene diisocyanate (1,3-xylene diisocyanate), 1,4-xylene diisocyanate, 1,5-naphthalene diisocyanate, 1,6-hexane diisocyanate, isophorone diisocyanate IPDI) and mixtures thereof. The polyisocyanate is preferably used in an amount of 5 to 30% by weight of the photopolymerizable urethane acrylate oligomer weight.

(iii) acrylate alcohol

Acrylate alcohols used in the present invention include one or more (meth) acrylates and hydroxy groups, preferred examples of which are 2-hydroxyethyl (meth) acrylate, 2-hydroxy Propyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxy-3-phenyloxypropyl (meth) acrylate, 4-hydroxybutyl acrylate, neopentyl glycomono (meth) acrylate, 4-hydroxycyclohexyl (meth) acrylate, 1,6-hexanediol mono (meth) acrylate, pentaerythritol penta (meth) acrylic Elate, dipentaerythritol penta (meth) acrylate, and mixtures thereof are mentioned. The acrylate alcohol is preferably used in an amount of 5 to 30% by weight of the photopolymerizable urethane acrylate oligomer weight.

(iv) urethane reaction catalyst

The urethane reaction catalyst used in the present invention is a catalyst which is added in a small amount during the urethane reaction, and examples thereof include copper naphthenate, cobalt naphthenate, zinc naphthenate, n-butyltinlaurate, and tristil. Amines (tristhylamine), 2-methyltriethylenediamide and mixtures thereof. The reaction catalyst is preferably used in an amount of 0.01 to 1% by weight of the photopolymerizable urethane acrylate oligomer weight.

(v) polymerization inhibitor

Preferred examples of the polymerization inhibitor used in the present invention include hydroquinone, hydroquinone monomethyl ether, para-benzoquinone, phenothiazine and mixtures thereof, and the weight of the photopolymerized urethane acrylate oligomer Preference is given to using in amounts of 0.01 to 1% by weight.

The photopolymerized urethane acrylate oligomer can be synthesized from the respective components as follows:

50 to 85% of the total reaction amount and polyisocyanate (ii) to 5 to 15% of the total reaction amount are added to the washed reactor. The water in the reactor is controlled by vacuum depressurization for 30 minutes to 1 hour. The mixture is stirred at a speed of 60 ~ 150rpm and the temperature of the reactor is raised to 50 ~ 65 ℃. After the reactor temperature is maintained at 60 to 65 ° C. for 10 to 30 minutes, the urethane reaction catalyst (iv) is added at 0.01 to 0.03% of the total amount of the reaction. Check the exotherm of the reactants after the addition of the catalyst by changing the temperature, if the temperature rises sharply above 110 ℃ control the temperature to 80 ~ 90 ℃ with cooling water below room temperature. When the temperature change is maintained within 1 ~ 2 ℃ to report that the exotherm is finished, after the end of the exotherm, the reactor temperature is maintained at 70 to 90 ℃, the stirrer speed is maintained at 60 ~ 150rpm and reacted for 30 to 60 minutes. After the reaction, when NCO% is 1 to 10%, acrylate alcohol (iii) is quantified to 5 to 15% of the total amount of the reaction and charged into the reactor, and the urethane reaction catalyst (iv) is quantified to 0.01 to 0.03% of the total amount of the reaction. By adding. Check the exotherm by the temperature change to maintain the reactor temperature 60 to 80 ℃, stirring speed 60 to 150 rpm after the end of the exotherm. The reaction is maintained until the -NCO group of the reactants is completely removed, but the disappearance of the NCO group is confirmed by Infrared Spectroscopy. The photopolymerized urethane acrylate oligomer (A) is obtained after the NCO group has completely disappeared.

In the present invention, such a general photopolymerizable acrylate oligomer may be used, but it may be preferable to include Ethoxylated Polypropylene glycol having a weight average molecular weight of 2,000 ~ 5,000. This has the advantage of obtaining a photopolymerizable acrylate oligomer having a low glass transition temperature, elastic modulus and low viscosity.

(B) reactive monomer

Since the reactive monomer (B) used for this invention is used as a diluent for matching the working viscosity with the said oligomer (A) which has a polymer structure, a low molecular weight monomer is preferable. Reactive monomers comprising at least one acrylate group, methacrylate group or vinyl group are used in amounts of 1 to 40% by weight of the total weight of the coating composition. If it is less than 1% by weight, it is difficult to dilute the high-viscosity oligomeric compound (A) to a working viscosity of 3,000 to 10,000 cps (25 ° C). If it exceeds 40% by weight, the curing shrinkage of the film and the thermal stability at high temperatures The gel is formed to fall apart, the viscosity is increased, the particles are large, leading to an unbalanced surface during coating, there is a problem of light loss.

The reactive monomers have one or more various functional groups, preferably 1 to 8 ethylene oxide (-(CH ₂ ) ₂ O-) functional groups, in addition to at least one acrylate group, methacrylate group or vinyl group in the molecular structure. Can be. In particular, it is preferable to use a reactive monomer having a low tensile shrinkage while having a high tensile strength in the film state. Preferred examples thereof include phenoxyethyl acrylate, phenoxyethylene glycol acrylate, phenoxy tetraethylene glycol acrylate, phenoxy hexaethylene glycol acrylate, isobornyl acrylate (IBOA), isobornyl methacrylate, N-vinyl Pyrrolidone (N-VP), N-vinylcaprolactam (N-VC), N-vinylformamide (N-VF), acryloyl morpholine (ACMO), bisphenol ethoxylate diacrylate , Ethoxylate phenol monoacrylate, polyethyleneglycol 400 diacrylate, tripropyleneglycol diacrylate, trimethyl propane triacrylate (TMPTA), polyethyleneglycol diacrylate, ethylene oxide addition type triethylpropane tri Acrylate (ethylene oxide-addition triethylolpropan triacrylate; EO-TMPTA), pentaerythritol tetraacrylate (PETA), 1, 4-butanediol diacrylate, 1,6-hexanediol diacrylate, ethoxylated pentaerythritol tetraacrylate, ethoxylated nonylphenol acrylate, 2-phenoxyethyl acrylate, ethoxylated pentaerythritol tetraacrylate Toxylated bisphenol A diacrylate, alkoxylated nonylphenol acrylate, alkoxylated trifunctional acrylate ester, metallic diacrylate, 3 Trifunctional acrylate esters, trifunctional methacrylate esters, and mixtures thereof.

If necessary, a monomer having an effect of increasing adhesion can be further used to improve adhesion to the glass fiber surface.

(C) photoinitiator

Photoinitiator (C) in the present invention, the optical fiber coating is It is made to maintain a fast line speed of more than 1,800m / min, it is added to maintain the fast curing speed of the resin itself. The photoinitiator (C) receives ultraviolet energy to form free radicals and attack the double bonds in the resin to induce polymerization. Preferred examples thereof include commercially available Irgacure # 184 from Ciba Geigy (hydroxycyclohexylphenylketone), Igacure # 907 (2-methyl-1 [4- (methyl Thio) phenyl] -2-morpholino-propan-1-one (2-methyl-1 [4- (methylthio) phenyl] -2-morpholino-propan-1-one), Igacure # 500 (hydroxy Ketones and benzophenones, Igacure # 651 (benzildimethylketone), Darocure # 1173 (2-hydroxy-2-methyl-1-phenyl-propan-1-one (2-hydroxy-2-methyl-1-phenyl-propan-1-one)), Darocure TPO (2,4,6-trimethylbenzoyldiphenylphosophin oxide), Darocure CGI # 1800 (bisacyl phosphine oxide), Darocure CGI # 1700 (bisacyl phosphine oxide and hydroxycyclohexylphenylketone) The mixture of these is mentioned. The photoinitiator (C) is used in an amount of 1 to 5% by weight of the total weight of the coating composition.

(D) other additives-silane monomers, stabilizers or mixtures thereof

The photocurable coating composition of the present invention, in addition to the above-mentioned components, may further include a silane monomer, a stabilizer or a mixture thereof as an optional component. Silane-based monomers, stabilizers or mixtures thereof (D) may be used in amounts of 0.5 to 1.5% by weight of the total weight of the coating composition. These additives are readily commercially available and can cause a drop in cure rate if the additive content is outside the above range.

The photocurable coating composition of the present invention may further include a silane monomer, a stabilizer or a mixture thereof as an optional component in order to prevent the adhesion between the coating layer and the glass is reduced.

The silane monomer not only increases the adhesion between the coating layer and the glass but also fundamentally lowers the water absorption of the resin composition. Such silane monomers include vinyl trimethoxysilane, vinyl trimethoxysilane, vinyl tri (methoxyethoxy) silane, gamma-methacryloxypropyltrimethoxysilane, and gamma-glycidoxy, from Chisso, Japan. Propylmethoxysilane, gamma-aminopropyltriethoxysilane, gamma-mercaptopropyltrimethoxysilane and mixtures thereof can be used.

Stabilizers serve to improve the thermal and oxidative and storage stability of the coating composition. Representative oxidants include Irganox 1010, Iganox 1035, Iganox 1076, and mixtures thereof from Ciba. Can be mentioned.

The method of preparing the photocurable coating composition of the present invention is as follows.

A mixture comprising (A) a photopolymerized urethane acrylate oligomer, (B) a reactive monomer, (C) photoinitiator, (D) other additives, and (E) caprolactone silanol was placed in a reactor, at a temperature of 15-50 ° C. and It can be reacted with stirring at a uniform speed of 100 rpm or more using a dispersion impeller at a humidity of 60% or less. If the reaction temperature is less than 15 ° C., the viscosity of the oligomer (A) may increase and process problems may occur. If the temperature exceeds 50 ° C., the photoinitiator (C) may form a radical to cause a curing reaction. . If the reaction humidity exceeds 60%, the resulting coating composition may generate bubbles during the subsequent coating process, and side reactions may occur in which unreacted materials react with moisture in the air. In addition, if the stirring speed is less than 100rpm may not be well mixed.

In the photocurable coating composition for optical fibers of the present invention, as a result of the adhesion test on the glass, the adhesive force (B ₁ ) at high temperature and high humidity conditions (85 ° C., 95% RH) is at room temperature and humidity conditions (23 ° C., 50% RH). It is characterized in that it is larger than the adhesive force (B ₀ ) of, more preferably the adhesive force (B ₁ ) at high temperature and high humidity conditions (85 ℃, 95% RH) is the normal temperature and humidity conditions (23 ℃, 50% RH) 1.1 times or more than the adhesive force (B ₀ ) at is good. That is, as described above, the adhesive force B ₁ at high temperature and high humidity conditions (85 ° C. and 95% RH) is greater than the adhesive force B ₀ at normal temperature and humidity conditions (23 ° C. and 50% RH). When the photocurable coating composition for an optical fiber is applied to an optical fiber, it may be more strongly adhered than at room temperature and humidity conditions at high temperature and high humidity, and may not be easily peeled off.

In addition, it is preferable that the glass transition temperature (Tg) of the photocurable coating composition for optical fibers of the present invention is -60 degrees or less, and in particular, the elastic modulus at -60 degrees of the photocurable coating composition for optical fibers is 300 MPa. By the following, the optical fiber can be stably used even in the cryogenic condition of -60 degrees.

The optical fiber of the present invention comprises a glass core and a coating layer and coating obtained by curing the photocurable coating composition on the glass core, wherein the coating layer comprises a unit structure derived from caprolactone silanol, and for this purpose, The coating layer may be formed from the photocurable coating composition for an optical fiber of the present invention described above.

That is, after first coating the surface of the glass core with the photocurable coating composition of the present invention, and then coating the outer secondary coating composition, UV lamp (DRS10 / 12-part, 600watt, D-bulb manufactured by Fusion) The optical fiber having the coating layer of 125 micrometers thickness can be manufactured by exposing to hardening). At this time, the light amount of the UV lamp is 0.1 ~ 1 J / cm ² , the working speed is 300 ~ 1,800mpm.

Thus, the coating in the optical fiber of the present invention produced the high-temperature and high-humidity conditions coated strip from (85 ℃, 95% RH) the strength (S ₁₎ is a normal temperature and normal humidity condition (23 ℃, 50% RH) strip strength (S ₀₎ It is possible to express even greater characteristics, and S1 is more preferably 1.1 times larger than S0.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

≪ Examples and Comparative Examples &

Examples and comparative examples of the present invention are (A) photopolymerized urethane acrylate oligomer, (B) reactive monomer, (C) photoinitiator, (D) other additives and (E) caprolactone silanol as shown in Table 1 below. It was made into a component and content.

A mixture of these ingredients and contents was placed in a reactor and dispersed with stirring at a uniform speed of 180 rpm using a dispersing impeller at a temperature of 40 ° C. or less and a humidity of 50% or less.

Evaluation of Physical Properties of Photocurable Compositions

The mechanical properties of the coating compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 2 were measured as follows, and the results are shown in Table 2.

Adhesion to glass

The resin composition prepared on a 25 x 75 mm glass plate was coated with a bar coater to a thickness of 75 um, put it in a fixing frame, and injected with nitrogen to inject light into a 600 W 9 mm D-bulb of fusion yarn (model: DRS10 / 12-QN). UV is controlled by controlling 1.0 J / cm ² (UV-A range, 315-400 nm). The film cured in this manner should be constant to a thickness of 75 um. The cured film is cut into 25 mm X 50 mm and stored in a controlled desiccator at 23 ° C., relative humidity of 50% or less for one day. Using the 4443 UTM of Instron, the film was kept at an angle of 90 ^° and pulled at a speed of 25 mm / min to measure the adhesion between the film and the glass plate.

The hot-wet adhesive force was made in the same manner as described above, and then stored in a constant temperature and humidity chamber at 85 ° C. and 95% condition for one day, and then the adhesive force was measured in the same manner as described above.

Glass transition temperature (Tg)

The resin composition prepared on the glass plate washed with alcohol or acetone is applied to a constant thickness of 75um using a bar coater. This is irradiated with UV by controlling the amount of light to 1.0 J / cm ² (UV-A range, 315-400nm) with 600W 9mm D-bulb of Fusion Yarn (model: DRS10 / 12-QN). The film cured in this manner should be constant to a thickness of 75 um. Samples are prepared by cutting the cured film to 10 × 15 mm and stored in a controlled desiccator at 23 ° C., 50% relative humidity or less for one day. The prepared sample was mounted on DMTA IV (Dynamic mechanical temperature analysis manufacturer: Rheometry), and the modulus change was measured by increasing the temperature at 2 ° C / min from -100 ° C to 60 ° C. The test frequency used at this time was 1.0 radians / second. Measurement result Tg (glass transition temperature) was calculated from the tan delta peak of the graph.

Elastic modulus

The resin composition prepared on the glass plate washed with alcohol or acetone is applied to a constant thickness of 75um using a bar coater. This is irradiated with UV by controlling the amount of light to 1.0 J / cm ² (UV-A range, 315-400nm) with 600W 9mm D-bulb of Fusion Yarn (model: DRS10 / 12-QN). The film cured in this manner should be constant to a thickness of 75 um. Samples are prepared by cutting the cured film to 10 × 15 mm and stored in a controlled desiccator at 23 ° C., 50% relative humidity or less for one day. The prepared sample was mounted on DMTA IV (Dynamic mechanical temperature analysis manufacturer: Rheometry), and the modulus change was measured by increasing the temperature at 2 ° C / min from -100 ° C to 60 ° C. At this time, the elastic modulus (E ') was taken for each temperature.

As can be seen from Table 2, Examples 1 to 8 of the present invention containing carolactone silanol are superior in adhesion at high temperature and high humidity than adhesion to glass at room temperature and humidity. And, Examples 1 to 8 it can be seen that all the elastic modulus at -60 ℃ is formed to be lower than 300MPa.

Fiber optic manufacturing

The resin composition of the above example or comparative example was applied to the quartz glass fibers as the primary coating agent using an optical fiber drawing device (manufactured by Nextrom Co., Ltd), and then the secondary coating agent (EFiRON manufactured by SSCP corp.) LS-2171) was applied thereon and cured simultaneously. The glass fiber has a diameter of 125 μm, and a primary coating agent and a secondary coating agent were applied thereon to be 250 μm after curing. Curing was performed using UV lamp (DRS10 / 12-part, 600watt manufactured by Fusion), withdrawal speed was 1800mpm.

Strip strength measurement evaluation method of optical fiber

The optical fiber obtained by the above method was stored for one day at a temperature of 23 ° C. and a relative humidity of 50% or less. The optical fiber was fixed using an Instron 4443 UTM, and then stripped off the quartz glass fiber and the coating layer at a speed of 500 mm / min using an optical fiber stripper (PS-02, Fujkura, Japan).

   The high temperature and high humidity strip strength of the optical fiber was stored in a constant temperature and humidity chamber at 85 ° C. and 95% relative humidity for one day, and the quartz glass fiber and the coating layer were peeled off as described above. The force at this time is called the fiber strip strength, and the results are shown in Table 3.

Claims (13)

(A) a photopolymerizable urethane acrylate oligomer, (B) a reactive monomer comprising at least one acrylate group, methacrylate group or vinyl group, (C) photoinitiator (D) other additives, and (E) caprolactone silanol (Caprolactone Photocurable coating composition for optical fibers comprising silanol). The method according to claim 1, wherein (A) the photopolymerized urethane acrylate oligomer is 30 to 90% by weight, (B) 1 to 40% by weight of the reactive monomer comprising at least one acrylate group, methacrylate group or vinyl group, ( C) Photoinitiator 1 to 5% by weight, (D) other additives 0.5 to 1.5% by weight, (E) Caprolactone silanol (Caprolactone silanol) is a photocurable coating composition for optical fibers containing 0.5 to 20% by weight. The photocurable coating composition for an optical fiber according to claim 1, wherein the caprolactone silanol (E) is synthesized from tri-hydroxy caprolactone and isocyanurated silane. The photocurable coating composition for optical fibers according to claim 3, wherein the caprolactone silanol (E) is synthesized in a molar ratio of trihydroxy group caprolactone and isocyanurated silane in a ratio of 1 to 3: 1. The photocurable coating composition of claim 3, wherein the caprolactone silanol (E) is at least one selected from the compounds of Formulas 1 to 3.
[Formula 1]

Formula 2

Formula 3

The photocurable coating composition of claim 1, wherein the photopolymerizable acrylate oligomer (A) comprises Ethoxylated Polypropylene glycol having a weight average molecular weight of 2,000 to 5,000. According to claim 1, As a result of the adhesion test to the glass of the photocurable coating composition for the optical fiber, the adhesive force (B ₁ ) at high temperature and high humidity conditions (85 ℃, 95% RH) is the normal temperature and normal humidity conditions (23 ℃, 50 A photocurable coating composition for optical fibers that is greater than the adhesion force (B ₀ ) in% RH). The method according to claim 7, wherein the adhesive force (B ₁ ) in the high temperature and high humidity conditions (85 ℃, 95% RH) is 1.1 times or more compared to the adhesive force (B ₀ ) at normal temperature and humidity conditions (23 ℃, 50% RH). Photocurable coating composition for an optical fiber. The photocurable coating composition for an optical fiber according to claim 1, wherein the glass transition temperature (Tg) of the photocurable coating composition for an optical fiber is -60 degrees or less. The photocurable coating composition for an optical fiber according to claim 1, wherein the elastic modulus at -60 degrees of the photocurable coating composition for the optical fiber is 300 MPa or less. And a coating layer and a coating obtained by curing a photocurable coating composition on the glass core, wherein the coating layer comprises a unit structure derived from caprolactone silanol. 12. The optical fiber according to claim 11, wherein the photocurable coating composition forming the coating layer is a photocurable coating composition for an optical fiber of any one of claims 1 to 10. The coating strip strength (S ₁ ) at high temperature and high humidity conditions (85 ° C., 95% RH) is greater than the coating strip strength (S ₀ ) at room temperature and humidity conditions (23 ° C., 50% RH). Optical fiber.