JP2011158581A - Liquid curable resin composition for forming optical fiber tape layer, and optical fiber ribbon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid curable resin composition which is suitable for forming a thin-type optical fiber tape layer, having a low Young's modulus and moreover, superior resistance with respect to external stresses and surface sliding properties. <P>SOLUTION: The liquid curable resin composition contains (A) 40-80 mass% of a urethane (meth)acrylate having, on average, 1.1 to 3 structure units derived from polypropylene glycol having a number average molecular weight of 1,000 or smaller; (B) 15-45 mass% of a compound having one ethylenically unsaturated group; and (C) 0.1-5 mass% of a silicone compound having an average molecular weight of 1,500-30,000, each based on 100 mass% for the entire composition. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid curable resin composition for forming an optical fiber tape layer.

  With the expansion of broadband services in recent years, there has been a demand for further increase in the transmission capacity of optical fibers, and there is a need to accommodate a large number of optical fiber strands with a single optical cable at high density. Widely used for the purpose of high-density filling of optical fiber strands is an optical fiber ribbon (also referred to as a tape-type optical fiber strand) in which a plurality of optical fiber strands are combined into a single tape. .) An optical fiber ribbon has a capsule-shaped structure in which a coating (referred to as a tape layer) is applied around a plurality of optical fibers arranged in parallel depending on the shape thereof. 1A) and an adhesive layer made of resin between adjacent optical fiber strands among a plurality of optical fiber strands arranged in parallel (in the present invention, this adhesive layer is also a tape layer) There is an optical fiber ribbon having an edge bond type structure (an example is shown in FIG. 1B).

  In the case of an optical fiber ribbon having a capsule structure, a thin cross-section is taken into consideration in order to accommodate optical fiber strands in an optical cable at a high density and for branching optical fiber strands. Many optical fiber ribbons having a shape have been published (see, for example, Patent Documents 1 to 3 and Non-Patent Document 1). Such an optical fiber ribbon includes an optical fiber ribbon having a capsule structure with a thin tape layer (an example is shown in FIGS. 2A and 2B), and an adjacent optical fiber. There is an optical fiber ribbon (an example is shown in FIG. 2 (c)) having a capsule structure in which a concave portion is provided in a tape layer therebetween. An optical fiber ribbon having an edge bond structure (an example is shown in FIG. 2D) is also suitable for the purpose of reducing the cross-sectional area.

Since it is necessary to accommodate a large number of optical fiber ribbons in an optical cable, the tape layer of such an optical fiber ribbon is hard to stick to the tape layer (low sticking force) and is resistant to external force, especially Flexibility (small Young's modulus) and excellent bending resistance (high tensile strength at break and tensile elongation at break) are required.
Further, when the outermost layer of the optical fiber is a layer (also referred to as an ink layer) containing a pigment for identifying each optical fiber, a tape layer having appropriate adhesion with the ink layer is provided. Desired. If the adhesive force between the tape layer and the ink layer is too high, it becomes difficult to peel off the tape layer and take out each optical fiber when connecting the optical fiber. If the adhesive force is too low, This is because the boundary surface of the optical fiber may easily peel off and damage the coating layer of the optical fiber.

  However, the tape layer of the conventional optical fiber ribbon has a Young's modulus of about 300 to 1,000 MPa and a tensile elongation at break of about 40 to 60%. It was difficult to form a tape layer having both a high elongation rate, tensile elongation at break, and sticking force. Further, in the tape layer of the conventional optical fiber ribbon, the adhesiveness with the ink layer is about 1 to 20 N / m, and it is further difficult to achieve both the above properties and the adhesiveness with the ink layer. It was.

JP 2004-240014 A JP 2006-208940 A JP 2007-34078 A

Japanese Industrial Standard JIS C6838 “Tape Type Optical Fiber Core”

  An object of the present invention is an optical fiber tape having a low Young's modulus as a tape layer, excellent resistance to external stress (tensile rupture strength and tensile rupture elongation), low sticking force, and excellent adhesion to an ink layer. An object of the present invention is to provide a liquid curable resin composition suitable for forming a tape layer for forming a core tape layer.

  Therefore, the present inventors have blended various components with a liquid curable resin composition containing urethane (meth) acrylate, and have studied the strength, function, and bending resistance of the cured product as an optical fiber coating layer. As a result, the above object can be achieved by using a urethane (meth) acrylate having a specific structure derived from an aliphatic polyether polyol in combination with a compound having one ethylenically unsaturated group and a specific silicone compound. I found.

That is, according to the present invention, in an optical fiber ribbon having a plurality of optical fiber strands arranged in parallel, the thickness of the tape layer at a position passing through the center point of any optical fiber strand is 20 μm or less or adjacent light. An optical fiber ribbon (hereinafter referred to as “specific thin optical fiber ribbon”) having a tape layer thickness of 200 μm or less at a position passing through an intermediate point of a line segment connecting the center points of the fiber strands. A liquid curable resin composition used for forming a tape layer,
The total composition is 100% by mass,
(A) 40 to 80% by mass of urethane (meth) acrylate having an average of more than 1 structural unit derived from an aliphatic polyol and 4 or less,
(B) 15 to 45% by mass of a compound having one ethylenically unsaturated group, and (C) 0.1 to 5% by mass of a silicone compound having an average molecular weight of 1,500 to 30,000.
The liquid curable resin composition to be contained is provided.
Moreover, this invention provides the tape layer of the specific thin optical fiber tape core wire obtained by hardening | curing the said liquid curable resin composition.
The present invention also provides a specific thin optical fiber ribbon having the tape layer.

  The coating obtained by the liquid curable resin composition of the present invention has a low Young's modulus as a tape layer, excellent resistance to external stress (tensile breaking strength and tensile breaking elongation), low sticking force, and an ink layer. It has excellent adhesion. It is suitable for forming an optical fiber tape layer for forming a tape layer of an optical fiber ribbon having a thin shape.

It is a schematic diagram which shows the example of a general optical fiber tape core wire. (A) An example of an optical fiber ribbon having a capsule structure. (B) An example of an optical fiber ribbon having an edge bond type structure. It is a schematic diagram which shows a specific thin optical fiber tape core wire. (A) An example of a specific thin optical fiber ribbon having a capsule structure without a recess between optical fiber strands and having a tape layer between the optical fiber strands. (B) An example of a specific thin optical fiber ribbon that has a capsule-type structure with no recesses between the optical fiber strands, and the optical fiber strands are in contact with each other. (C) An example of a specific thin optical fiber ribbon having a capsule structure with a recess between optical fiber strands. A tape layer may be provided between the optical fiber strands, and the optical fiber strands may be in contact with each other. (D) An example of a specific thin optical fiber ribbon having an edge bond structure.

  A thin optical fiber tape core wire in which the liquid curable resin composition of the present invention is used is an optical fiber tape core wire having a plurality of parallel optical fiber strands, and the thickness of the tape layer is reduced. This is an optical fiber ribbon whose outer dimensions have been reduced. As a specific example of such a thin optical fiber ribbon, an optical fiber ribbon having a plurality of parallel optical fibers, the center point of any optical fiber constituting the tape strand The thickness of the tape layer at the position passing through the midpoint of the optical fiber tape core wire having a thickness of 20 μm or less at the position passing through the center or the line segment connecting the center points of the adjacent optical fiber strands. An optical fiber ribbon that is 200 μm or less is preferable (hereinafter collectively referred to as “specific thin optical fiber ribbon”). The specific thin optical fiber ribbon may have a capsule structure or an edge bond structure. The number of optical fiber strands constituting the specific thin optical fiber ribbon is arbitrary, but 2, 4, 5, 8, or 12 is typical in relation to JIS C6838.

  The thickness of the tape layer at the position passing through the center point of any optical fiber is the intersection of an arbitrary straight line passing through the center point of any optical fiber and the outer periphery of the optical fiber. The point A is the shortest length of the straight line distance between the points A and B when the point B is the intersection of the straight line and the outer periphery of the optical fiber ribbon. In the case of a specific thin optical fiber ribbon having an edge bond structure (FIG. 2D), the thickness of the tape layer at a position passing through the center point of any optical fiber is interpreted as zero. . Further, the thickness of the tape layer at a position passing through the midpoint of the line segment connecting the center points of the adjacent optical fiber strands is defined as a line segment L connecting the center points of the adjacent optical fiber strands. The width of the tape layer on the straight line passing through the point M and perpendicular to the line segment L when the intermediate point of the line segment L is the point M.

  Further, in general, an optical fiber strand is formed by coating the outer periphery of a single glass fiber made of quartz, glass, or the like with a relatively soft primary coating layer, and further, the outer periphery is a secondary harder than the primary coating layer. It may have a structure coated with a coating layer, and may have an upjacket layer or an ink layer on the outer periphery of the secondary coating layer. Although the diameter of the glass fiber which comprises an optical fiber strand is not specifically limited, Generally, it is 125 micrometers, and the diameter of an optical fiber strand is 250-900 micrometers according to a use. In order to fill the optical fiber, it is preferable to reduce the diameter of each optical fiber, and it is preferable that the diameter of the optical fiber used for the specific thin optical fiber ribbon is about 250 μm. .

Below, each essential component and non-essential component mix | blended with the liquid curable resin composition of this invention are demonstrated.
The urethane (meth) acrylate which is the component (A) of the present invention is a urethane (meth) acrylate having an average of more than 1 structural unit derived from an aliphatic polyol. The number of structural units derived from the aliphatic polyol in the urethane (meth) acrylate molecule is preferably more than 1.0 and 4 or less, more preferably 1.1 to 4 on average, and 1.5 to 1.5 on average. Three is particularly preferred. Here, the average value is a number average.

  Since the component (A) has a structure derived from an aliphatic polyol having a flexible structure, the urethane (meth) acrylate has a more flexible structure and is useful for reducing the Young's modulus of the cured product. On the other hand, instead of the aliphatic polyol, for example, when using a polyol having a more rigid structure such as an aromatic ring structure or an alicyclic structure, the structure of the urethane (meth) acrylate becomes more rigid, There is a tendency to increase the Young's modulus of the cured product.

  When the number of structural units derived from the aliphatic polyol in the urethane (meth) acrylate molecule exceeds an average of 1, the density of urethane bonds in the urethane (meth) acrylate molecule increases and the polar structure increases. Therefore, the adhesiveness with the ink layer having a hydrophilic structure can be improved. On the other hand, the average number of structural units derived from the aliphatic polyol in the urethane (meth) acrylate molecule is 4 or less, preventing the density of the urethane bond from becoming excessive and the viscosity of the composition from becoming excessive. can do.

Furthermore, since the average number of structural units derived from aliphatic polyols in the urethane (meth) acrylate molecule exceeds one on average, the apparent molecular weight of the structure derived from aliphatic polyols increases, making it more flexible. Urethane (meth) acrylate having a simple structure is obtained, which is useful for reducing the Young's modulus of the cured product, improving the bending resistance, and reducing the sticking force. In the present invention, the “apparent molecular weight of the structure derived from the aliphatic polyol” means that the number of structural units derived from the aliphatic polyol having the number average molecular weight L is m in average in the urethane (meth) acrylate molecule. The molecular weight corresponding to the value of L × m.
For this reason, for example, the number average molecular weight L is 4,500 as compared with urethane (meth) acrylate (not corresponding to the component (A)) having m = 1 as an aliphatic polyol having a number average molecular weight L of 9,000. The urethane (meth) acrylate having an aliphatic polyol at m = 2 (corresponding to the component (A)) has the same apparent molecular weight of the structure derived from the aliphatic polyol, but the Young's modulus and bending resistance When forming the tape layer which is excellent in the balance of adhesiveness, adhesiveness and adhesion of the ink layer.

  The urethane (meth) acrylate as the component (A) is produced, for example, by reacting an aliphatic polyol, diisocyanate, and a hydroxyl group-containing (meth) acrylate. That is, it is produced by reacting an isocyanate group of diisocyanate with a hydroxyl group of an aliphatic polyol and a hydroxyl group of a hydroxyl group-containing (meth) acrylate.

  As this reaction, for example, an aliphatic polyol, diisocyanate and a hydroxyl group-containing (meth) acrylate are charged together and reacted; a method in which an aliphatic polyol and diisocyanate are reacted, and then a hydroxyl group-containing (meth) acrylate is reacted; Method of reacting hydroxyl group-containing (meth) acrylate and then reacting aliphatic polyol; reacting diisocyanate and hydroxyl group-containing (meth) acrylate, then reacting aliphatic polyol, and finally reacting hydroxyl group-containing (meth) acrylate again And the like.

The aliphatic polyol is not particularly limited as long as it does not have a cyclic structure such as an aromatic ring structure or an alicyclic structure and has an aliphatic structure. For example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly Hexamethylene glycol, polyheptamethylene glycol, polydecamethylene glycol and other aliphatic polyether polyols, and these aliphatic polyether polyols react with maleic acid, fumaric acid, adipic acid, sebacic acid and other aliphatic carboxylic acids. In addition to the aliphatic polyester polyol obtained, a reaction product of the aliphatic polyether polyol and ε-caprolactone, and an aliphatic polycaprolactone polyol such as poly (ε-caprolactone), polycarbonate of polytetrahydrofuran, 1,6- Examples thereof include aliphatic polycarbonate polyols such as polycarbonate of hexanediol. These aliphatic polyols can be used alone or in combination of two or more.
Examples of the aliphatic polyol as described above include PTMG650, PTMG1000, PTMG2000 (manufactured by Mitsubishi Chemical), PEG1000, Unisafe DC1100, DC1800 (manufactured by Nippon Oil & Fats), PPG-400, PPG1000, EXCENOL 720, 1020 (and above, Asahi Glass Urethane. ), PPTG2000, PPTG1000, PTG400, PTGL2000 (above, manufactured by Hodogaya Chemical Co., Ltd.), Kuraray polyols P-2010, P-3010, P-4010, P-5010 (above, made by Kuraray), etc. be able to.
Among these aliphatic polyols, aliphatic polyester polyols, aliphatic polycaprolactone polyols, and aliphatic polycarbonate polyols have a polar group such as an ester bond or a carbonyl bond, thereby particularly improving the adhesion between the tape layer and the ink layer. It is preferable because it can be improved.
The molecular weight of the aliphatic polyol used here is not particularly limited, but a number average molecular weight of 12,000 or less is preferable because the viscosity of the composition does not become excessive. The apparent molecular weight of the structure derived from the aliphatic polyol is preferably 1,000 to 12,000 for the same reason. Here, the number average molecular weight is determined by a gel permeation chromatography method (GPC method) using polystyrene as a molecular weight standard.

  Examples of the diisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 3,3′-dimethyl-4,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 3,3′-dimethylphenylene diisocyanate, 4,4′-biphenylene diisocyanate, 1,6-hexane Diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), 2,2,4-trimethylhexamethylene diisocyanate, bis (2-isocyanate ethyl) Fumarate, 6-isopropyl-1,3-phenyl diisocyanate, 4-diphenylpropane diisocyanate, lysine diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, tetramethylxylylene diisocyanate, 2,5 (or 2,6) -bis (Isocyanatemethyl) -bicyclo [2.2.1] heptane and the like. In particular, 2,4-tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, methylene bis (4-cyclohexyl isocyanate) and the like are preferable. These diisocyanates can be used alone or in combination of two or more.

  Examples of the hydroxyl group-containing (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 2-hydroxy-3-phenyloxypropyl (meth) acrylate. 1,4-butanepolyol mono (meth) acrylate, 2-hydroxyalkyl (meth) acryloyl phosphate, 4-hydroxycyclohexyl (meth) acrylate, 1,6-hexanepolyol mono (meth) acrylate, neopentyl glycol mono ( (Meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolethane di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) Acrylate, the following formula (1) or (2)

(In Formula (1) and Formula (2), R ¹ represents a hydrogen atom or a methyl group, and n represents a number of 1 to 15)
(Meth) acrylate represented by the following. Moreover, the compound obtained by addition reaction with glycidyl group containing compounds, such as alkyl glycidyl ether, allyl glycidyl ether, and glycidyl (meth) acrylate, and (meth) acrylic acid can also be used.
Of these hydroxyl group-containing (meth) acrylates, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and the like are particularly preferable. These hydroxyl group-containing (meth) acrylate compounds can be used alone or in combination of two or more.

  The use ratio of the aliphatic polyether polyol, diisocyanate and hydroxyl group-containing (meth) acrylate is such that the isocyanate group contained in the diisocyanate is 2.5 to 4.0 equivalents based on 1 equivalent of the hydroxyl group contained in the aliphatic polyether polyol. It is preferable that the hydroxyl group of the (meth) acrylate is 0.5 to 2.0 equivalents.

  In the reaction of these compounds, for example, copper naphthenate, cobalt naphthenate, zinc naphthenate, dibutyltin dilaurate, triethylamine, 1,4-diazabicyclo [2.2.2] octane, 2,6,7-trimethyl-1 It is preferable to use 0.01 to 1 part by mass of a urethane catalyst such as 1,4-diazabicyclo [2.2.2] octane with respect to 100 parts by mass of the total amount of reactants. The reaction temperature is usually 10 to 90 ° C, particularly preferably 30 to 80 ° C.

  The urethane (meth) acrylate as the component (A) is blended in an amount of 40 to 80% by mass, preferably 50 to 75% by mass, particularly preferably 55 to 75% by mass in the entire composition of the liquid curable resin composition of the present invention. The If it exists in this range, it is preferable when expressing the preferable Young's modulus of a hardened | cured material, tensile breaking strength, and tensile elongation at break.

In the liquid curable resin composition of the present invention, a urethane (meth) acrylate other than the component (A) can be blended within a range not inhibiting the effects of the invention. The structure of the urethane (meth) acrylate other than the component (A) is not particularly limited. For example, a polyol having a cyclic structure such as an aromatic ring structure or an alicyclic structure, a diisocyanate, and a hydroxyl group-containing (meth) acrylate are reacted. Increase the Young's modulus of the cured product by blending urethane (meth) acrylate obtained by reaction with urethane (meth) acrylate having no polyol structure obtained by reacting diisocyanate and hydroxyl group-containing (meth) acrylate. You can also adjust the direction.
The urethane (meth) acrylate other than the component (A) can be blended at 10% by mass or less in the total composition of the liquid curable resin composition of the present invention, and preferably 5% by mass or less. When it exceeds 10 mass%, the viscosity of the composition may be excessive, or the Young's modulus of the cured product may be excessive.

  Examples of the compound (monofunctional monomer) having one ethylenically unsaturated group as component (B) include vinyl group-containing lactams such as N-vinylpyrrolidone and N-vinylcaprolactam; isobornyl (meth) acrylate, bornyl ( (Meth) acrylate, tricyclodecanyl (meth) acrylate, (meth) acrylate having an alicyclic structure such as 4-butylcyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate; benzyl (meth) acrylate, phenoxyethyl (Meth) acrylate, (meth) acrylate having an aromatic ring structure such as (meth) acrylate represented by the following formula (3); (meth) acrylate having a heterocyclic structure such as acryloylmorpholine, vinylimidazole, vinylpyridine, etc. It is done. Furthermore, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) ) Acrylate, butyl (meth) acrylate, amyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) ) Acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodec (Meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, butoxyethyl (meth) acrylate , Ethoxydiethylene glycol (meth) acrylate, benzyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxyethylene glycol (meth) acrylate, ethoxyethyl (meth) acrylate, methoxypolyethylene glycol (meta ) Acrylate, methoxypolypropylene glycol (meth) acrylate, diacetone (meth) acrylamide, Sobutoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, t-octyl (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, 7-amino-3,7-dimethyl Examples include octyl (meth) acrylate, N, N-diethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, hydroxybutyl vinyl ether, lauryl vinyl ether, cetyl vinyl ether, 2-ethylhexyl vinyl ether, and the like. These compounds having one ethylenically unsaturated group can be used alone or in combination of two or more.

(In the formula (3), R ² , R ³ , R ⁴ and R ⁵ are independent of each other and are a hydrogen atom or a methyl group, and m is an integer of 1 to 5)

  Of these compounds having one ethylenically unsaturated group, (meth) acrylates having a cyclic structure such as an alicyclic structure, an aromatic ring structure or a heterocyclic structure prevent the Young's modulus of the cured product from excessively decreasing. In order to increase the curing rate, vinyl group-containing lactams such as N-vinylpyrrolidone and N-vinylcaprolactam are preferable.

  Examples of commercially available compounds having one ethylenically unsaturated group include IBXA (manufactured by Osaka Organic Chemical Industry), Aronix M-111, M-113, M114, M-117, TO-1210 (above, manufactured by Toagosei). ) Can be used.

(B) The compound which has one ethylenically unsaturated group of component is 15-45 mass% in the whole composition of the liquid curable resin composition of this invention, Preferably it is 20-40 mass%, Most preferably, it is 25- 35% by mass is blended.
In the present invention, the total amount of the compound (B) having one ethylenically unsaturated group is 100% by mass, and 50% by mass or more, preferably 60 to 100% by mass of (meth) acrylate having a cyclic structure. It is preferable in order to prevent the Young's modulus of the cured product from excessively decreasing. The (meth) acrylate having a cyclic structure may be any of the above (meth) acrylates having a cyclic structure such as an alicyclic structure, an aromatic ring structure or a heterocyclic structure, and in particular, isobornyl (meth) acrylate is used. This is preferable because the effect of preventing the Young's modulus of the cured product from excessively decreasing is great.

In the liquid curable resin composition of the present invention, if necessary, a compound (polyfunctional monomer) having two or more ethylenically unsaturated groups other than the component (B) as long as the characteristics of the present invention are not impaired. (B2) can be contained. Specific examples of the compound having two or more ethylenically unsaturated groups include, but are not limited to, trimethylolpropane tri (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, pentaerythritol tri (meth) acrylate, Ethylene glycol di (meth) acrylate, triethylene glycol diacrylate, tetraethylene glycol di (meth) acrylate, bis ((meth) acryloyloxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane ("tricyclo Decanediyldimethanol di (meth) acrylate ”), polyethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyling Cold di (meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, bisphenol A diglycidyl ether end (meth) acrylic acid addition, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (Meth) acrylate, polyester di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, tricyclodecane dimethanol di (meth) Di (meth) acrylate of diol which is an adduct of acrylate, bisphenol A ethylene oxide or propylene oxide, ethylene oxide of hydrogenated bisphenol A Examples thereof include di (meth) acrylate of diol which is an adduct of propylene oxide, epoxy (meth) acrylate obtained by adding (meth) acrylate to diglycidyl ether of bisphenol A, triethylene glycol divinyl ether, and the like.
Examples of commercially available products of these polyfunctional monomers include NK ester A-DCP Iupimer UV (manufactured by Shin-Nakamura Chemical Co., Ltd.), SA-1002 (manufactured by Mitsubishi Chemical), Aronix M-215, M-315, M- 325, TO-1210 (above, manufactured by Toagosei Co., Ltd.) can be used.
The compounding amount of these polyfunctional monomers is preferably 0 to 5% by mass, particularly preferably 0 to 3% by mass, in the liquid curable resin composition of the present invention. When it exceeds 5 mass%, the crosslinking density in hardened | cured material rises and a Young's modulus may increase excessively.

The component (C) of the present invention is a silicone compound having an average molecular weight of 1,500 to 30,000. By blending the component (C), the sticking force of the tape layer can be improved, and the optical fiber tape strand can be filled in the optical cable at a high density. When the average molecular weight of the component (C) is in the above range, a sufficient surface property improving effect can be obtained. A more preferable average molecular weight is 1,500 to 20,000, and 3,000 to 15,000 are more preferable.
Examples of the silicone compound include polyether-modified silicone, alkyl-modified silicone, urethane acrylate-modified silicone, urethane-modified silicone, methylstyryl-modified silicone, epoxy polyether-modified silicone, alkylaralkyl polyether-modified silicone, and the like. Modified silicone is particularly preferred. The polyether-modified silicone, at least one group to the silicon atom ^{R 11 - (R 12 O)} s -R 13 - ( wherein, R ¹¹ represents a hydroxyl group or an alkoxy group having 1 to 10 carbon atoms, R ¹² Represents an alkylene group having 2 to 4 carbon atoms (wherein R ¹² may be a mixture of two or more alkylene groups); R ¹³ represents an alkylene group having 2 to 12 carbon atoms; A polydimethylsiloxane compound having a bond number of 20 is preferred. Among these, R ¹² is preferably an ethylene group or a propylene group, and particularly preferably an ethylene group. Commercially available products of the silicone compound include, for example, SH28PA; dimethylpolysiloxane polyoxyalkylene copolymer, manufactured by Toray Dow Corning, FM0411; Silaplane, Chisso, SF8428; dimethylpolysiloxane polyoxyalkylene copolymer (containing side chain OH) ), Manufactured by Toray Dow Corning, BYK UV3510 (produced by Big Chemie Japan, dimethylpolysiloxane-polyoxyalkylene copolymer), DC57 (produced by Toray Dow Corning Silicone, dimethylpolysiloxane-polyoxyalkylene copolymer), etc. Can be mentioned. Moreover, the silicone compound which has reactive groups, such as a (meth) acryloyl group, may be sufficient.

  (C) component is 0.1-5 mass% in the whole composition of the liquid curable resin composition of this invention, Preferably 0.5-3 mass% is mix | blended. If it exceeds 5% by mass, it may be difficult for the component (C) to be dissolved or uniformly dispersed in the composition, and if it is less than 0.1% by mass, the sticking force may be excessive.

  Furthermore, when the liquid curable resin composition of the present invention is cured with ultraviolet rays, the composition can contain (D) a photopolymerization initiator.

Examples of the photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-chloro. Benzophenone, 4,4'-dimethoxybenzophenone, 4,
4'-diaminobenzophenone, Michler ketone, benzoin propyl ether, benzoin ethyl ether, benzyl dimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl- 1-phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 2 , 4,6-trimethylbenzoyldiphenylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide; IRGACURE 184, 369, 651, 500, 907, CG 1700, CGI1750, CGI1850, CG24-61; Darocure1116,1173 (manufactured by Ciba Specialty Chemicals); Lucirin TPO (manufactured by BASF); Ubecryl P36 (manufactured by UCB), and the like.

  When (D) a photopolymerization initiator is used, it is preferable to use a photosensitizer in combination as necessary. Examples of the photosensitizer include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, and isoamyl 4-dimethylaminobenzoate. Ubekrill P102, 103, 104, 105 (above, manufactured by UCB) and the like.

  (D) It is preferable to mix | blend 0.1-10 mass% of photoinitiators in the whole composition of a composition, especially 0.3-7 mass%.

  In the liquid curable resin composition of the present invention, various additives such as an antioxidant, a colorant, an ultraviolet absorber, a light stabilizer, and a silane coupling are added to the liquid curable resin composition of the present invention, as necessary. An agent, a thermal polymerization inhibitor, a leveling agent, a surfactant, a storage stabilizer, a plasticizer, a lubricant, a solvent, a filler, an anti-aging agent, a wettability improver, a coating surface improver and the like can be blended.

  The liquid curable resin composition of the present invention is cured by heat and / or radiation. Here, the radiation refers to infrared rays, visible rays, ultraviolet rays, X rays, electron beams, α rays, β rays, γ. A line etc.

  The tape layer which is a cured film obtained by curing the liquid curable resin composition of the present invention preferably exhibits a Young's modulus of 0.5 to 40 MPa, more preferably 0.8 to 20 MPa, and 0.8 to 5 MPa is particularly preferable. The cured film preferably exhibits a tensile elongation at break of 100% or more, more preferably 100 to 150%, and particularly preferably 110 to 130%. The cured film preferably exhibits a tensile breaking strength of 0.5 to 10 MPa, more preferably 1 to 7 MPa, and particularly preferably 1 to 5 MPa. When the Young's modulus and the tensile elongation at break are in the above ranges, it becomes easy to fill a number of specific thin optical fiber ribbons into one optical cable. In addition to the Young's modulus and tensile breaking elongation, the tensile breaking strength is in the above range, so that the resistance to external stress is further increased, and it is easier to fill a number of specific thin optical fiber ribbons into one optical cable. become.

  EXAMPLES Next, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these Examples at all. The amount of each component is part by mass unless otherwise specified.

[Production Example 1: Synthesis of urethane (meth) acrylate (A) having an average of 1.5 structural units derived from polypropylene glycol]
A reaction vessel equipped with a stirrer was charged with 41.4 g of polypropylene glycol having a number average molecular weight of 700, 17.2 g of 2,4-tolylene diisocyanate, and 0.016 g of 2,6-di-t-butyl-p-cresol, While stirring these, the liquid temperature was cooled to 15 ° C. After adding 0.054 g of dibutyltin dilaurate and confirming that the increase in the liquid temperature is no longer observed, after reacting at 35 ° C. for 1 hour, the liquid temperature of 9.2 g of 2-hydroxyethyl acrylate does not exceed 50 ° C. The solution was added dropwise while controlling so that the mixture was stirred and reacted for 2 hours while controlling at 65 to 70 ° C. The reaction was terminated when the residual isocyanate became 0.1% by mass or less. Let the obtained urethane acrylate be UA-1.
The obtained urethane (meth) acrylate UA-1 has a structure represented by the following formula (4).
HEA-TDI- (PPG700-TDI) _1.5 -HEA (4)
[In Formula (4), HEA represents a structure derived from 2-hydroxyethyl acrylate, TDI represents a structure derived from 2,4-tolylene diisocyanate, and PPG 700 represents a structure derived from polypropylene glycol having a number average molecular weight of 700. Represents. “-” Indicates a urethane bond. The above description of the equation is the same after equation (5). ]

[Production Example 2: Synthesis of urethane (meth) acrylate (A) having an average of three structural units derived from polypropylene glycol]
A reaction vessel equipped with a stirrer was charged with 134.8 g of 2,4-toluene diisocyanate, 68.9 g of polypropylene oxide having a molecular weight of 3000, and 0.018 g of 2,6-di-t-butyl-p-cresol. Next, 0.061 g of dibutyltin diurarate was added, and the mixture was stirred for 1 hour while controlling the liquid temperature at 25 to 35 ° C. Thereafter, 1.7 g of hydroxyethyl acrylate was added, stirring was continued for 1 hour at a liquid temperature of 50 to 60 ° C., and the reaction was terminated when the residual isocyanate became 0.1% by mass or less to obtain urethane acrylate. Let the obtained urethane acrylate be UA-2.
The obtained urethane (meth) acrylate UA-2 has a structure represented by the following formula (5).
HEA-TDI- (PPG3000-TDI) ₃ -HEA (5)
[In Formula (5), PPG3000 represents the structure derived from the polypropylene glycol of number average molecular weight 3000. ]

[Production Example 3: Synthesis of urethane (meth) acrylate (A) having an average of two structural units derived from aliphatic polyester polyol]
In a reaction vessel equipped with a stirrer, 2.6 g of 2,4-toluene diisocyanate, Kuraray polyol P-5010 having a molecular weight of 5000: poly [(3-methyl-1,5-pentanediol) -alt- (adipic acid)] 49 .6g, 2,6-di-t-butyl-p-cresol 0.013g was charged. Next, 0.043 g of dibutyltin diurarate was added, and the mixture was stirred for 1 hour while controlling the liquid temperature at 25 to 35 ° C. Thereafter, 1.16 g of hydroxyethyl acrylate was added, stirring was continued for 1 hour at a liquid temperature of 50 to 60 ° C., and the reaction was terminated when the residual isocyanate was 0.1% by mass or less to obtain urethane acrylate. Let the obtained urethane acrylate be UA-3.
The obtained urethane (meth) acrylate UA-3 has a structure represented by the following formula (6).
HEA-TDI- (P5010-TDI) ₂ -HEA (6)
[In Formula (6), P5010 represents the structure derived from Kuraray polyol P-5010. ]
Kuraray polyol P-5010: Poly [(3-methyl-1,5-pentanediol) -alt- (adipic acid)] is a fat having a number average molecular weight of 5,000 having a structure represented by the following formula (7) Group polyester polyol.

[Comparative Production Example 4: Synthesis of urethane (meth) acrylate having an average of one structural unit derived from polypropylene glycol (not applicable to component (A))]
A reaction vessel equipped with a stirrer was charged with 36.909 g of polypropylene glycol having a number average molecular weight of 700, 18.366 g of 2,4-tolylene diisocyanate, and 0.016 g of 2,6-di-t-butyl-p-cresol, While stirring these, the liquid temperature was cooled to 15 ° C. After adding 0.054 g of dibutyltin dilaurate and confirming that the increase in the liquid temperature was not observed, after reacting at 35 ° C. for 1 hour, 12.245 g of 2-hydroxyethyl acrylate did not reach 50 ° C. or higher. The solution was added dropwise while controlling so that the mixture was stirred and reacted for 2 hours while controlling at 65 to 70 ° C. The reaction was terminated when the residual isocyanate became 0.1% by mass or less. Let the obtained urethane acrylate be UA'-4.
The obtained urethane (meth) acrylate UA′-4 has a structure represented by the following formula (8).
HEA-TDI-PPG700-TDI-HEA (8)

[Comparative Production Example 5: Synthesis of urethane (meth) acrylate (not corresponding to component (A)) having an average of one structural unit derived from polypropylene glycol]
A reaction vessel equipped with a stirrer was charged with 9.0 g of 2,4-toluene diisocyanate, 85.0 g of polypropylene oxide having a molecular weight of 3000, and 0.024 of 2,6-di-t-butyl-p-cresol. Next, 0.008 g of dibutyltin diurarate was added, and the mixture was stirred for 1 hour while controlling the liquid temperature at 25 to 35 ° C. Thereafter, 6.0 g of hydroxyethyl acrylate was added, and stirring was continued for 1 hour at a liquid temperature of 50 to 60 ° C., and the reaction was terminated when the residual isocyanate was 0.1% by mass or less to obtain urethane acrylate. Let the obtained urethane acrylate be UA'-5.
The obtained urethane (meth) acrylate UA′-5 has a structure represented by the following formula (9).
HEA-TDI-PPG3000-TDI-HEA (9)

[Comparative Production Example 6: Synthesis of urethane (meth) acrylate (not corresponding to component (A)) having an average of one structural unit derived from polypropylene glycol]
A reaction vessel equipped with a stirrer was charged with 3.71 g of 2,4-toluene diisocyanate, 93.7 g of polypropylene oxide having a molecular weight of 8000, and 0.024 g of 2,6-di-t-butyl-p-cresol. Next, 0.08 g of dibutyltin diurarate was added, and the mixture was stirred for 1 hour while controlling the liquid temperature at 25 to 35 ° C. Thereafter, 2.47 g of hydroxyethyl acrylate was added, stirring was continued for 1 hour at a liquid temperature of 50 to 60 ° C., and the reaction was terminated when the residual isocyanate was 0.1% by mass or less to obtain urethane acrylate. Let the obtained urethane acrylate be UA'-6.
The obtained urethane (meth) acrylate UA′-6 has a structure represented by the following formula (10).
HEA-TDI-PPG8000-TDI-HEA (10)
[In the formula (10), PPG8000 represents a structure derived from polypropylene glycol having a number average molecular weight of 3000. ]

[Comparative Production Example 7: Synthesis of urethane (meth) acrylate (not corresponding to component (A)) having an average of 1.5 structural units derived from a polyol having an aromatic ring structure]
To a reaction vessel equipped with a stirrer, 0.018 g of 2,6-di-t-butyl-p-cresol, 26.4 g of 2,4-tolylene diisocyanate, and 0.06 g of dibutyltin dilaurate were added, and then stirred. Cooled to ° C. 14.1 g of hydroxyethyl acrylate was added dropwise while controlling the liquid temperature to be 20 ° C. or lower, and the mixture was then heated to 40 ° C. and stirred for 1 hour. Thereafter, the liquid temperature was cooled to 20 ° C., and 36.4 g of ethylene oxide addition diol of bisphenol A (manufactured by NOF Corporation, DA400) was added. After confirming the exotherm, the mixture was stirred at 65 ° C. for 3 hours, and the reaction was terminated when the residual isocyanate was 0.1% by mass or less. Let the obtained (A) urethane (meth) acrylate be UA'-7.
The obtained urethane (meth) acrylate UA′-7 has a structure represented by the following formula (11).
HEA-TDI- (DA400-TDI) _1.5 -HEA (11)
[In Formula (11), DA400 represents a structure derived from Uniol DA400 (manufactured by NOF Corporation; number average molecular weight 400), which is a diol having a bisphenol structure. ]

Examples 1-3, Comparative Examples 1-5
Each component was put into a reaction vessel equipped with a stirrer according to Table 1, and stirred at a liquid temperature of 50 ° C. until a uniform solution was obtained, to obtain a liquid curable resin composition. The composition in Table 1 is parts by mass.

Test Examples The liquid curable resin compositions obtained in the examples and comparative examples were cured by the following method to prepare test pieces, and the following evaluations were performed. The results are also shown in Table 1.

1. viscosity:
The composition was allowed to stand in a constant temperature water bath at 25 ° C. for 30 minutes, and then the viscosity was measured using a B-type viscometer.

2. Young's modulus:
A liquid curable resin composition was applied on a glass plate using an applicator bar having a thickness of 200 μm, and this was cured by irradiation with ultraviolet rays having an energy of 1 J / cm ² under air to obtain a film for measuring Young's modulus. . A strip-shaped sample was prepared from this film so that the stretched portion had a width of 6 mm and a length of 25 mm, and a tensile test was performed at a temperature of 23 ° C. and a humidity of 50%. The Young's modulus was obtained from the tensile strength at a tensile rate of 1 mm / min and a strain of 2.5%.

3. Tensile elongation at break, tensile strength at break:
Using a tensile tester (manufactured by Shimadzu Corporation, AGS-50G), the breaking strength and breaking elongation of the test piece were measured under the following measurement conditions.
Tensile speed: 50 mm / min Distance between marked lines (measurement distance): 25 mm
Measurement temperature: 23 ° C
Relative humidity: 50% RH

4). Sticking force:
A liquid curable resin composition is applied onto a glass plate using an applicator bar having a thickness of 100 μm, and this is cured by irradiation with ultraviolet rays having an energy of 0.1 J / cm ² under 1% or 5% oxygen. Got. The cured surfaces of the films were bonded together and allowed to stand for 24 hours at 23 ° C. and 50% relative humidity. A strip-shaped sample having a width of 1 cm was prepared from the laminated film, and a 180 ° peel test was performed at a pulling speed of 50 mm / min to measure the sticking force.

5. Adhesion with ink layer:
A secondary material (Desolite manufactured by JSR Co.) was applied on the glass in a thickness of 130 μm, and 0.1 J / cm ^{2 in} an air atmosphere using a 3.5 kW metal halide lamp (OMX SMX-3500 / F-OS). Irradiated with ultraviolet rays, a cured film was obtained. Thereafter, UV ink (DSM, 751 ink) was applied by a spin coater, and a 3.5 kW metal halide lamp (Oak, SMX-3500 / F-OS) was used at 1% oxygen concentration or 5% oxygen concentration. Was irradiated with ultraviolet rays of 0.05 J / cm ² and cured on the secondary material to a thickness of about 10 μm. The liquid composition of each Example and Comparative Example was similarly applied on this cured film with a spin coater (2000 rpm, 20 seconds), and a 3.5 kW metal halide lamp (manufactured by Oak Co., SMX-3500 / F-OS) was used. A multilayer cured film was obtained by irradiating with an ultraviolet ray of 0.5 J / cm ^{2 in} an air atmosphere. A strip having a width of 1 cm was cut out and subjected to a 90-degree peel test in accordance with JIS K6854. Adhesion was measured by peeling the resin according to the present invention from the UV ink. The pulling speed was 5 mm / min.

In Table 1,
Irgacure 184; 1-hydroxy-cyclohexyl-phenyl-ketone (manufactured by Ciba Specialty Chemicals).
Lucirin TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (manufactured by Ciba Specialty Chemicals).
SH280PA: Graft polymer of dimethylpolysiloxane polycarbinol (manufactured by Dow Corning Toray).
SH190: Graft polymer of dimethylpolysiloxane polycarbinol (manufactured by Dow Corning Toray).

As is clear from the results in Table 1, the cured product formed of the liquid curable resin composition of the present invention has a low Young's modulus, a large tensile breaking strength and a tensile breaking elongation, a low sticking force, and an ink. Adhesive strength with the layer was high, and it was suitable for forming a tape layer of a specific thin optical fiber ribbon.
On the other hand, in the comparative example 1 which does not contain (C) component, the sticking force became excessive. In Comparative Example 2, a structural unit derived from a urethane (meth) acrylate having only one structural unit derived from an aliphatic polyol having a number average molecular weight of 700 instead of the component (A) and an aliphatic polyol having a number average molecular weight of 3000 In this example, only one urethane (meth) acrylate is blended, the Young's modulus is excessive, the sticking force is excessive, and the adhesion with the ink layer is excessive. Comparative Example 3 is an example in which a urethane (meth) acrylate having only one structural unit derived from an aliphatic polyol having a number average molecular weight of 700 is blended in place of the component (A), the Young's modulus is excessive, In addition to the breaking strength being too small, the adhesion with the ink layer is too small. Comparative Example 4 is an example in which urethane (meth) acrylate having only one structural unit derived from an aliphatic polyol having a number average molecular weight of 8000 is blended in place of the component (A), and the Young's modulus is high because the polyol has a large molecular weight. Is low, but the tensile strength at break is too low, and the adhesion with the ink layer is too low. Comparative Example 5 is an example in which urethane (meth) acrylate having only one structural unit derived from an aromatic polyol having a number average molecular weight of 400 is blended in place of the component (A), and the polyol has a rigid structure. Therefore, the Young's modulus was excessive, the tensile elongation at break was too small, and the adhesion with the ink layer was too small.

10 Optical fiber 20 Tape layer 30 Tape layer thickness

Claims (4)

In an optical fiber ribbon having a plurality of optical fiber strands arranged in parallel, the thickness of the tape layer at a position passing through the center point of any optical fiber strand is 20 μm or less, or each center of adjacent optical fiber strands Used for forming a tape layer of an optical fiber ribbon (hereinafter referred to as “specific thin optical fiber ribbon”) having a tape layer thickness of 200 μm or less at a position passing through an intermediate point of a line segment connecting points. A liquid curable resin composition, comprising:
The total composition is 100% by mass,
(A) 40 to 80% by mass of urethane (meth) acrylate having an average of more than 1 structural unit derived from an aliphatic polyol and 4 or less,
(B) 15 to 45% by mass of a compound having one ethylenically unsaturated group, and (C) 0.1 to 5% by mass of a silicone compound having an average molecular weight of 1,500 to 30,000.
Liquid curable resin composition to contain.   The liquid curable resin composition according to claim 1, wherein 50% by mass or more of the whole component (B) is a compound having an alicyclic structure or an aromatic ring structure.   A tape layer of a specific thin optical fiber ribbon, obtained by curing the liquid curable resin composition according to claim 1.   A specific thin optical fiber ribbon having the tape layer according to claim 3.