JP2011140569A - Liquid curable resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid curable resin composition for outermost layer coating of a primary coated optical fiber, which is excellent in functions as an up-jacket material, hardly suffers an external damage because an especially high hardness is ensured, and is excellent in storage stability of the liquid composition and peelability from an adjacent coating layer. <P>SOLUTION: The liquid curable resin composition for outermost layer coating of a primary coated optical fiber contains the following components (A1), (A2), (B) and (C): (A1) one or more urethane (meth)acrylates selected from a urethane (meth)acrylate having a structure derived from a polyol having an aromatic structure or an alicyclic structure and a urethane (meth)acrylate which is a reaction product of a diisocyanate and a hydroxyl group-containing (meth)acrylate and does not have a structure derived from a polyol; (A2) a urethane (meth)acrylate having a structure derived from a polyester polyol; (B) a compound having an ethylenically unsaturated group other than urethane (meth)acrylates; and (C) a polyester polyol compound having a number-average molecular weight of ≥3,000. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a liquid curable resin composition for coating an outermost layer of an optical fiber, which is used after being applied to the surface of a secondary coating layer or an ink layer of an optical fiber.

  In the production of an optical fiber, a glass fiber is hot melt-spun and a resin coating is applied for the purpose of protection and reinforcement. As a resin coating, there is known a structure in which a flexible primary coating layer is first provided on the surface of an optical fiber and a highly rigid secondary coating layer is provided on the outside thereof. Furthermore, a colored layer (also referred to as an ink layer) for identification may be provided outside the secondary coating layer.

The outer diameter of the glass fiber with a primary coating layer and a secondary coating layer is usually about 250 μm, but this outer periphery is coated with another resin layer for the purpose of improving workability by hand. The outer diameter is increased to about 500 to 900 μm. Such a resin coating layer is usually referred to as an upjacket layer. A state in which a glass fiber is provided with a primary coating layer and a secondary coating layer is usually referred to as an optical fiber strand. However, when an ink layer and an upjacket layer are provided, the state including these layers is referred to as an optical fiber strand. That's it. Therefore, the up jacket layer is the outermost layer of the optical fiber.
Since the upjacket layer itself does not require optical characteristics, transparency is not particularly required, and it may be colored to impart visual discrimination. The up-jacket layer is an important characteristic that it can be easily peeled off without damaging the primary coating layer, the secondary coating layer, and the ink layer in the lower layer when performing the operation of connecting the optical fiber. .

  The liquid curable resin for forming the upjacket layer (hereinafter referred to as “upjacket material” or “liquid curable resin composition for covering the outermost layer”) has excellent coatability and can be drawn at high speed; Sufficient strength; excellent heat resistance; excellent weather resistance; excellent resistance to acids, alkalis, etc .; excellent oil resistance; low water absorption and hygroscopicity; low generation of hydrogen gas It is liquid and has good storage stability; properties such as good peelability from the ink layer and secondary coating layer are required.

  However, in the conventional upjacket material, the upjacket layer is firmly bonded to the secondary coating layer and the ink layer. Therefore, when the upjacket layer is peeled off from the optical fiber in the optical fiber connection work, etc. In many cases, the coating layer, the secondary coating layer and the ink layer were damaged. For this reason, there was a problem that the workability of the optical fiber connection work was lowered.

  As an up-jacket material with improved peelability, a composition in which three types of polysiloxane compounds are blended (Patent Document 1), a composition in which particles made of an organic or inorganic material are blended in a resin material (Patent Documents 2 and 3) ), A composition containing a polyether polyol (Patent Document 4) has been reported.

Conventionally, the up-jacket layer of the optical fiber strand has been mainly designed with a low Young's modulus as a priority (Patent Documents 1 to 3). However, since it is the outermost layer of the optical fiber strand, it is exposed to the outside air. There is a problem that it is easy to be damaged. For this reason, it may be desired that the hardness is high and it is difficult to be damaged.
On the other hand, an outermost layer of an optical fiber having a high Young's modulus is also known (Patent Document 4), but there is a problem of storage stability of the liquid composition.

Japanese Patent Laid-Open No. 10-287717 JP-A-9-324136 JP 2000-273127 A JP 2008-249788 A

  The object of the present invention is excellent for the function as an up-jacket material, particularly hard and difficult to be damaged, and for coating the outermost layer of an optical fiber with excellent storage stability of the liquid composition and excellent peelability from the adjacent coating layer. The object is to provide a liquid curable resin composition.

  Therefore, the present inventors blended various components with a liquid curable resin composition containing urethane (meth) acrylate, and the strength and releasability of the upjacket layer, which is the cured product, and storage stability of the liquid composition. As a result of examining the properties, urethane (meth) acrylate having a rigid structure, urethane (meth) acrylate having a flexible structure, and polyester polyol having a specific molecular weight can be used in combination to achieve the above object. I found it.

That is, the present invention includes the following components (A1), (A2), (B) and (C):
(A1) Urethane (meth) acrylate having a structure derived from a polyol having an aromatic structure or an alicyclic structure, and a urethane having no structure derived from a polyol, which is a reaction product of diisocyanate and a hydroxyl group-containing (meth) acrylate One or more urethane (meth) acrylates selected from (meth) acrylates,
(A2) urethane (meth) acrylate having a structure derived from polyester polyol,
(B) a compound having an ethylenically unsaturated group other than urethane (meth) acrylate,
(C) Provided is a liquid curable resin composition for coating an outermost layer of an optical fiber, which contains a polyester polyol compound having a number average molecular weight of 3000 or more.
Moreover, this invention provides the outermost coating layer of the optical fiber strand obtained by hardening | curing the liquid curable resin composition for outermost layer coating | cover of the said optical fiber strand.
Furthermore, this invention provides the optical fiber strand which has the said outermost coating layer.

  The liquid curable resin composition of the present invention is excellent in storage stability, and the coating obtained by curing the liquid curable resin composition has a very high Young's modulus and appropriate toughness. Moreover, the peelability from the adjacent coating layer is good. It is suitable for forming an outermost layer of an optical fiber, that is, an upjacket layer.

Component (A) used in the present invention is urethane (meth) acrylate. (A) Urethane (meth) acrylate includes urethane (meth) acrylate having a rigid structure for obtaining a cured product having a high Young's modulus and urethane (meth) having a flexible structure for obtaining a cured product having excellent toughness. Acrylate is included.
As urethane (meth) acrylate having a rigid structure, (A1) urethane (meth) acrylate having a structure derived from a polyol having an aromatic structure or an alicyclic structure, and reaction of diisocyanate and hydroxyl group-containing (meth) acrylate One or more urethane (meth) acrylates selected from urethane (meth) acrylates that are products and do not have a structure derived from polyols are preferred. Since the urethane (meth) acrylate of component (A1) has a rigid structure, the Young's modulus of the cured product can be increased.
As the urethane (meth) acrylate having a flexible structure, urethane (meth) acrylate having a structure derived from (A2) polyester polyol is preferable. In addition to component (A2), urethane (meth) acrylate obtained by reacting aliphatic polyol other than (A3) polyester polyol, diisocyanate, and hydroxyl group-containing (meth) acrylate can also be blended. Since urethane (meth) acrylate of these components (A2) and (A3) has a flexible structure, it can avoid that hardened | cured material becomes too brittle. In particular, since the component (A2) has a highly polar polyester structure, a cured product having excellent toughness (breaking strength, breaking elongation) can be formed.
The composition of the present invention obtains a cured product that balances high Young's modulus and appropriate toughness by blending urethane (meth) acrylate having a rigid structure and urethane (meth) acrylate having a flexible structure. be able to.

  Among the components (A1), urethane (meth) acrylate having a structure derived from a polyol having an aromatic structure or an alicyclic structure, and (A2) urethane (meth) acrylate having a structure derived from a polyester polyol are, for example, It is produced by reacting a polyol or polyester polyol having an aromatic structure or an alicyclic structure with a diisocyanate and a hydroxyl group-containing (meth) acrylate. That is, it is produced by reacting the isocyanate group of diisocyanate with the hydroxyl group of polyol and the hydroxyl group of hydroxyl group-containing (meth) acrylate, respectively.

  As this reaction, for example, polyol, diisocyanate and hydroxyl group-containing (meth) acrylate are charged together and reacted; polyol and diisocyanate are reacted, and then hydroxyl group-containing (meth) acrylate is reacted; diisocyanate and hydroxyl group-containing ( Examples include a method of reacting meth) acrylate and then reacting polyol; a method of reacting diisocyanate and hydroxyl group-containing (meth) acrylate, then reacting polyol, and finally reacting hydroxyl group-containing (meth) acrylate again.

Among the components (A1), a urethane (meth) acrylate which is a reaction product of diisocyanate and a hydroxyl group-containing (meth) acrylate and does not have a structure derived from a polyol, the isocyanate group of the diisocyanate is converted to a hydroxyl group-containing (meth) acrylate. It is produced by reacting with a hydroxyl group.
Hereinafter, the polyol, diisocyanate, and hydroxyl group-containing (meth) acrylate used for the production of the urethane (meth) acrylate as the component (A1) or (A2) will be described.

  Examples of the polyol having an aromatic structure or an alicyclic structure used for the synthesis of the component (A1) include an alkylene oxide addition polyol of bisphenol A, an alkylene oxide addition polyol of bisphenol F, hydrogenated bisphenol A, and hydrogenated bisphenol F. , Hydrogenated bisphenol A alkylene oxide addition polyol, hydrogenated bisphenol F alkylene oxide addition polyol, etc., bisphenol structure polyol, hydroquinone alkylene oxide addition polyol, naphthohydroquinone alkylene oxide addition polyol, anthrahydroquinone alkylene oxide addition polyol 1,4-cyclohexane polyol and its alkylene oxide addition polyol, tricyclodecane poly , Pentacyclopentadecane polyol, pentacyclopentadecane dimethanol, xylene oxide addition polyol, alkylene oxide addition polyol of bisphenol F, alkylene oxide addition polyol of 1,4-cyclohexane polyol, 1,4-cyclohexanedimethanol, dicyclo Examples thereof include a dimethylol compound of pentadiene and tricyclodecane dimethanol.

  These polyols can be used alone or in combination of two or more. In particular, a polyol having a bisphenol structure is preferable, and an alkylene oxide addition polyol of bisphenol A is preferable. These polyols can be obtained as commercial products such as Uniol DA400, DA700, DA1000, and DB400 (manufactured by NOF Corporation).

  Examples of the polyester polyol used for the synthesis of the component (A2) include alkyl polyols such as ethylene glycol, propylene glycol, butylene glycol, tetramethylene glycol, neopentyl glycol, trimethylolpropane, pentaerythritol, sorbitol, mannitol, and glycerin. Polyols obtained by reacting a polybasic acid with a polyol having the aromatic structure or a polyol having the alicyclic structure, or a polybasic acid such as a polymer thereof, and the like. In particular, polycaprolactone polyol is preferable.

  Examples of the polycaprolactone polyol include a polymer of ε-caprolactone, or ethylene glycol, propylene glycol, tetramethylene glycol, 1,2-butylene glycol, 1,6-hexane polyol, neopentyl glycol, 1,4-cyclohexanedi Examples thereof include divalent polyols such as methanol and 1,4-butane polyol, or polycaprolactone polyols obtained by reacting these polymers with ε-caprolactone. These polyols can be obtained as commercial products such as Plaxel 205, 205AL, 212, 212AL, 220, 220AL (manufactured by Daicel Chemical Industries, Ltd.).

  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, 4-diphenylpropane diisocyanate Diisocyanates having an aromatic ring structure such as tetramethylxylylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene Diisocyanate, diisocyanate having an alicyclic structure such as 2,5 (or 2,6) -bis (isocyanate methyl) -bicyclo [2.2.1] heptane, 1,6-hexane diisocyanate, methylene bis (4-cyclohexyl isocyanate) ), 2,2,4-trimethylhexamethylene diisocyanate, bis (2-isocyanatoethyl) fumarate, 6-isopropyl-1,3-phenyl diisocyanate, lysine diisocyanate and other diisocyanates having an aliphatic structure. Among these, diisocyanates having an aromatic ring structure and diisocyanates having an alicyclic structure are preferable, and 2,4-tolylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, methylene bis (4-cyclohexyl isocyanate, and the like are particularly 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-butane polyol mono (meth) acrylate, 2-hydroxyalkyl (meth) acryloyl phosphate, 4-hydroxycyclohexyl (meth) acrylate, 1,6-hexane polyol 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 the formula, 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.

  In the case of synthesizing a urethane (meth) acrylate having a structure derived from a polyol or polyester polyol having an aromatic structure or an alicyclic structure, the proportion of polyol, diisocyanate and hydroxyl group-containing (meth) acrylate used is included in the polyol. It is preferable that the isocyanate group contained in the diisocyanate is 1.1 to 3 equivalents and the hydroxyl group of the hydroxyl group-containing (meth) acrylate is 0.2 to 1.5 equivalents with respect to 1 equivalent of the hydroxyl group.

  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- It is preferable to use 0.01 to 1 part by mass of a urethanization catalyst such as 1,4-diazabicyclo [2.2.2] octane with respect to 100 parts by mass of the total amount of the reactants. The reaction temperature is usually 10 to 90 ° C, particularly preferably 30 to 80 ° C.

Component (A1) urethane (meth) acrylate is 10 to 50% by mass, more preferably 10 to 45% by mass, especially 20 to 30% by mass, based on 100% by mass of the entire liquid curable resin composition of the present invention. It is preferable in terms of the Young's modulus of the cured product.
The urethane (meth) acrylate of component (A2) is 5 to 45% by mass, further 10 to 40% by mass, particularly 10 to 30% by mass, based on 100% by mass of the whole liquid curable resin composition of the present invention. It is preferable from the viewpoint of mechanical properties such as Young's modulus, breaking strength, and breaking elongation of the cured product.

  In this invention, a component (A1) is 50-100 mass% with respect to 100 mass% of the whole component (A) urethane (meth) acrylate, Furthermore, 50-80 mass%, Especially 55-70 mass% is mix | blended. It is preferable. By blending within this range, a cured product in which a high Young's modulus and appropriate toughness (breaking strength, breaking elongation) are balanced can be obtained.

  Component (A3) of the present invention is urethane (meth) acrylate obtained by reacting aliphatic polyol other than polyester polyol, diisocyanate, and hydroxyl group-containing (meth) acrylate. Component (A3) is produced by reacting the isocyanate group of the diisocyanate with the hydroxyl group of the aliphatic polyol and the hydroxyl group of the hydroxyl group-containing (meth) acrylate, respectively.

  The urethane (meth) acrylate of (A3) can be produced by using an aliphatic polyol other than polyester polyol as the polyol component in the synthesis method of the urethane (meth) acrylate of components (A1) and (A2). it can.

  The aliphatic polyol used for the synthesis of the component (A3) is not particularly limited as long as it is an aliphatic polyol other than polyester polyol, and examples thereof include polyether polyol, polycarbonate polyol, and other polyols. The polymerization mode of each structural unit of these polyols is not particularly limited, and any of random polymerization, block polymerization, and graft polymerization may be used. Examples of the polyether polyol include ring-opening copolymerization of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, polyheptamethylene glycol, polydecamethylene glycol, or two or more ion-polymerizable cyclic compounds. Examples include aliphatic polyether polyols obtained. Examples of the ion polymerizable cyclic compound include ethylene oxide, propylene oxide, butene-1-oxide, isobutene oxide, 3,3-bischloromethyloxetane, tetrahydrofuran, 2-methyltetrahydrofuran, 3-methyltetrahydrofuran, dioxane, trioxane, Tetraoxane, cyclohexene oxide, styrene oxide, epichlorohydrin, glycidyl methacrylate, allyl glycidyl ether, allyl glycidyl carbonate, butadiene monooxide, isoprene monooxide, vinyl oxetane, vinyl tetrahydrofuran, vinyl cyclohexene oxide, phenyl glycidyl ether, butyl glycidyl ether, glycidyl benzoate And cyclic ethers such as esters. Further, a polyether polyol obtained by ring-opening copolymerization of the above ion polymerizable cyclic compound with a cyclic imine such as ethyleneimine, a cyclic lactone acid such as β-propiolactone or glycolic acid lactide, or dimethylcyclopolysiloxane. Can also be used. Specific combinations of the two or more ion-polymerizable cyclic compounds include, for example, tetrahydrofuran and propylene oxide, tetrahydrofuran and 2-methyltetrahydrofuran, tetrahydrofuran and 3-methyltetrahydrofuran, tetrahydrofuran and ethylene oxide, propylene oxide and ethylene oxide, butene- Examples thereof include terpolymers of 1-oxide and ethylene oxide, tetrahydrofuran, butene-1-oxide, ethylene oxide, and the like. The ring-opening copolymer of these ion-polymerizable cyclic compounds may be bonded at random or may be bonded in a block form.

  These aliphatic polyols are, for example, PTMG650, PTMG1000, PTMG2000 (manufactured by Mitsubishi Chemical), PPG-400, PPG1000, PPG2000, PPG3000, EXCENOL720, 1020, 2020 (above, manufactured by Asahi Glass Urethane), PEG1000, Unisafe DC1100, DC1800. (Above, manufactured by NOF Corporation), PPTG2000, PPTG1000, PTG400, PTGL2000 (above, manufactured by Hodogaya Chemical), Z-3001-4, Z-3001-5, PBG2000A, PBG2000B (above, manufactured by Daiichi Kogyo Seiyaku) It can be obtained as a commercial product. Diols that are copolymers of butene-1-oxide and ethylene oxide are commercially available such as EO / BO500, EO / BO1000, EO / BO2000, EO / BO3000, and EO / BO4000 (above, manufactured by Daiichi Kogyo Seiyaku). It can be obtained as a product.

  Examples of the polycarbonate polyol include polycarbonate of polytetrahydrofuran and polycarbonate of 1,6-hexane polyol, and commercially available products include DN-980, 981, 982, 983 (above, made by Nippon Polyurethane), PC -8000 (manufactured by PPG, USA), PC-THF-CD (manufactured by BASF) and the like.

  (A3) Urethane (meth) acrylate obtained by reacting aliphatic polyol other than polyester polyol, diisocyanate, and hydroxyl group-containing (meth) acrylate is 0 to 40 mass in the total composition of the liquid curable resin composition of the present invention. %, Further 3 to 35% by mass, particularly 3 to 30% by mass is preferable in terms of imparting toughness by improving the breaking strength and breaking elongation of the cured product.

  Component (B) is a compound having an ethylenically unsaturated group other than urethane (meth) acrylate. As the component (B), a polymerizable monofunctional compound and / or a polymerizable polyfunctional compound can be used. Here, the polymerizable monofunctional compound is (B1) a compound having one ethylenically unsaturated group, and the polymerizable polyfunctional compound is (B2) a compound having two or more ethylenically unsaturated groups. is there.

  (B1) Examples of the compound having one ethylenically unsaturated group include vinyl group-containing lactams such as N-vinylpyrrolidone and N-vinylcaprolactam, isobornyl (meth) acrylate, bornyl (meth) acrylate, and tricyclodecanyl. It has an alicyclic structure such as (meth) acrylate, dicyclopentanyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, (meth) acrylate represented by the following formula (4) or (5) (meta ) Acrylate; (meth) acrylate having an aromatic structure such as benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, (meth) acrylate represented by the following formula (6), acryloylmorpholine, vinylimidazole, vinylpyridine ( In the present specification, the heteroaromatic structure is To (meth) acrylate handled as (meth) acrylate having an aromatic structure.) And the like. 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, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, methoxyethylene glycol (meth) acrylate, ethoxyethyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, methoxypolypropylene glycol (Meth) acrylate, diacetone (meth) acrylamide, isobutoxymethyl (meth) acrylate Luamide, N, N-dimethyl (meth) acrylamide, t-octyl (meth) acrylamide, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, 7-amino-3,7-dimethyloctyl (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 compounds represented by the following formula (3) Can do.

Wherein R ² represents a hydrogen atom or a methyl group, R ³ represents an alkylene group having 2 to 6 carbon atoms, preferably 2 to 4 carbon atoms, and R ⁴ represents a hydrogen atom or 1 to 12 carbon atoms, preferably 1 -9 represents an alkyl group, and r represents a number of 0-12, preferably 1-8)

Wherein R ⁵ represents a hydrogen atom or a methyl group, R ⁶ represents an alkylene group having 2 to 8 carbon atoms, preferably 2 to 5 carbon atoms, R ⁷ represents a hydrogen atom or a methyl group, and p is preferably 1 to 4)

(In formula, R < ⁸ >, R <^9> , R < ¹⁰ > and R < ¹¹ > are mutually independent, a hydrogen atom or a methyl group is shown, q shows the number of 1-5.)

  Among these (B1) compounds having one ethylenically unsaturated group, (meth) acrylate having an alicyclic structure and (meth) acrylate having an aromatic structure can increase the Young's modulus of the cured product. Among them, isobornyl (meth) acrylate is particularly preferable. Further, vinyl group-containing lactams such as N-vinylpyrrolidone and N-vinylcaprolactam are preferable because they improve the curing rate.

  Examples of commercially available compounds having one (B1) ethylenically unsaturated group include IBXA (manufactured by Osaka Organic Chemical Industry), Aronix M-111, M-113, M114, M-117, TO-1210 ( As described above, Toagosei) and the like can be used.

  These (B1) compounds having one ethylenically unsaturated group are 10 to 70% by mass, further 20 to 60% by mass, and particularly 25 to 40% by mass in the total composition of the liquid curable resin composition of the present invention. It is preferable to mix | blend.

  The (meth) acrylate having an aromatic structure or an alicyclic structure is more than 50% by mass and 100% by mass or less, particularly 55 to 80% by mass, and further 60 to 75% by mass is preferably blended.

  Examples of the compound (B2) having two or more ethylenically unsaturated groups include trimethylolpropane tri (meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, pentaerythritol tri (meth) acrylate, Ethylene glycol diacrylate, tetraethylene glycol di (meth) acrylate, tricyclodecane dimethylol diacrylate, 1,4-butanepolyol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (Meth) acrylate, tripropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra ( T) acrylate, polyester di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate di (meth) acrylate, tricyclodecane dimethylol diacrylate, triethylene Glycol divinyl ether and the following formula (7)

(Wherein R ¹² and R ¹³ are independent of each other and represent a hydrogen atom or a methyl group, and n represents a number of 1 to 100)
The compound etc. which are represented by these are mentioned.

  Of these (B2) compounds having two or more ethylenically unsaturated groups, trimethylolpropane tri (meth) acrylate and 1,6-hexanediol di (meth) acrylate are preferred.

  Examples of commercially available compounds having two or more (B2) ethylenically unsaturated groups include Iupimer UV, SA1002 (above, manufactured by Mitsubishi Chemical), Aronix M-215, M-315, M-325 (above, Toagosei) can be used. Moreover, Arrowix TO-1210 (product made from Toagosei) can be used.

  The compound having two or more ethylenically unsaturated groups (B2) is 3 to 20% by mass, further 5 to 18% by mass, particularly 8 to 15% in the total composition of the liquid curable resin composition of the present invention. It is preferable to be blended by mass%.

  Component (B) is the sum of components (B1) and (B2), and is 15 to 80% by mass, further 25 to 70% by mass, particularly 30 to 55% by mass in the total composition of the liquid curable resin composition of the present invention. % Is preferable.

  Component (C) used in the present invention is a polyester polyol compound having a number average molecular weight of 3000 or more. By adding the component (C), the peelability from the ink layer or the like adjacent to the outermost layer of the optical fiber can be further improved. When the component (C) is a polyester polyol, the solubility in the composition of the present invention is good, and a uniform state can be maintained even if the liquid composition is stored for a long period of time. Since the molecular weight of the component (C) is 3000 or more, the migration to the ink layer can be suppressed, and good releasability can be maintained over a long period of time. The molecular weight of the polyol compound is more preferably 3000 to 10000, and further preferably 4000 to 8000.

  (C) The number average molecular weight of the polyester polyol compound is a molecular weight in terms of polystyrene determined by gel permeation chromatography.

  Examples of the polyester polyol compound include a polyester polyol obtained by reacting a dihydric alcohol and a dibasic acid. Examples of the dihydric alcohol include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, tetramethylene glycol, polytetramethylene glycol, 1,6-hexane polyol, neopentyl glycol, and 3-methyl-1,5-pentane polyol. 1,9-nonane polyol, 2-methyl-1,8-octane polyol, and the like. Examples of the dibasic acid include dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, adipic acid, and sebacic acid. As a commercial item, Kuraray polyol P-3010 (made by Kuraray) etc. can be obtained.

  The compounding amount of the component (C) is 1 to 35% by mass in the total composition of the liquid curable resin composition of the present invention, further 5 to 30% by mass, from the viewpoint of peelability and strength and weather resistance of the outermost layer. In particular, the content is preferably 5 to 25% by mass.

In the liquid curable resin composition of the present invention, a polyol compound other than the component (C) polyester polyol can be blended within a range not impairing the characteristics of the present invention. Specific examples of such a polyol compound include polyether polyols, polycarbonate polyols, polycaprolactone polyols, polyester polyols other than the component (C), and the like.

The liquid curable resin composition of the present invention may further contain a silicone compound having a number average molecular weight of 1,500 to 35,000 as the component (D). By mix | blending the said component (D), the peelability from the adjacent layer of the outermost layer of the optical fiber strand formed using the resin composition of this invention can be improved further. When the average molecular weight of the component (D) is less than 1,500, a sufficient peelability improvement effect cannot be obtained, and when the number average molecular weight exceeds 35,000, the peelability improvement effect becomes insufficient. A more preferred number average molecular weight is 1,500 to 20,000, further preferably 1,500 to 20,000, and particularly preferably 3,000 to 15,000.
Moreover, it is preferable that a component (D) does not have polymerizable groups, such as an ethylenically unsaturated group. Since component (D) does not have a polymerizable group such as an ethylenically unsaturated group, good peelability can be maintained even when a thermal history is applied.

  (D) The number average molecular weight of the silicone compound is a molecular weight in terms of polystyrene determined by a gel permeation chromatography method.

Examples of the silicone compound (D) include polyether-modified silicone, alkyl-modified silicone, urethane acrylate-modified silicone, urethane-modified silicone, methylstyryl-modified silicone, epoxy polyether-modified silicone, and alkylaralkyl polyether-modified silicone. Of these, polyether-modified silicone is particularly preferred. The polyether-modified silicone, at least one group to the silicon atom ^{R 14 - (R 15 O)} s -R 16 - ( wherein, R ¹⁴ represents a hydroxyl group or an alkoxy group having 1 to 10 carbon atoms, R ¹⁵ Represents an alkylene group having 2 to 4 carbon atoms (R ¹⁵ may be a mixture of two or more alkylene groups), R ¹⁶ represents an alkylene group having 2 to 12 carbon atoms, and s represents 1 to 20 carbon atoms. A polydimethylsiloxane compound having a number attached thereto is preferred. Among these, R ¹⁵ is preferably an ethylene group or a propylene group, and particularly preferably an ethylene group.

  Among the commercially available products of the silicone compound, those having no polymerizable group such as an ethylenically unsaturated group include, for example, SH28PA, SH190 (produced by Toray Dow Corning, dimethylpolysiloxane polyoxyalkylene copolymer), Paintad 19, 54 (Toray Dow Corning, dimethylpolysiloxane polyoxyalkylene copolymer), FM0411 (manufactured by Chisso, Silaplane), SF8428 (manufactured by Toray Dow Corning, dimethylpolysiloxane polyoxyalkylene copolymer (side chain) OH)), BYK UV3510 (produced by BYK Japan, dimethylpolysiloxane-polyoxyalkylene copolymer), DC57 (produced by Toray Dow Corning, dimethylpolysiloxane-polyoxyalkylene copolymer), and the like. . Moreover, as a commercial item of the said silicone compound which has an ethylenically unsaturated group, Tego Rad 2300, 2200N (made by Tego Chemie) etc. can be mentioned, for example.

  Component (D) is blended in an amount of 0.1 to 50% by mass, and further 0.5 in the total composition of the liquid curable resin composition of the present invention, in terms of peelability, strength and weather resistance of the outermost layer. It is preferably -40% by mass, particularly 1-20% by mass.

  Furthermore, the liquid curable resin composition of the present invention can contain (E) a polymerization initiator. As the polymerization initiator, a thermal polymerization initiator or a photoinitiator can be used.

  When the liquid curable resin composition of the present invention is thermosetting, a thermal polymerization initiator such as a peroxide or an azo compound is usually used. Specific examples include benzoyl peroxide, t-butyl-oxybenzoate, azobisisobutyronitrile, and the like.

Moreover, when the liquid curable resin composition of this invention is photocurable, it is preferable to use a photoinitiator and to use a photosensitizer together as needed. Here, 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-chlorobenzophenone, 4,4′-dimethoxybenzophenone, 4,4′-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyldimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2 -Methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, thioxanthone, diethylthioxanthone, 2-isopropylthioxanthone, -Chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis- (2,6-dimethoxy) Benzoyl) -2,4,4-trimethylpentylphosphine oxide; IRGACURE 184, 369, 651, 500, 907, CGI 1700, CGI 1750, CGI 1850, CG 24-61; Lucirin TPO (manufactured by BASF); Ubekrill P36 (manufactured by UCB) and the like.

  Examples of the photosensitizer include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, 4-dimethylamino. Isoamyl benzoate; Ubecril P102, 103, 104, 105 (above, manufactured by UCB) and the like.

  When the liquid curable resin composition of the present invention is cured using both heat and ultraviolet rays, the thermal polymerization initiator and the photopolymerization initiator can be used in combination. The polymerization initiator is preferably blended in the total composition in an amount of 0.1 to 10% by mass, particularly 0.3 to 7% by 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 preferably has a viscosity of 1 to 20 Pa · s, more preferably 1 to 10 Pa · s.

  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 film obtained by curing the liquid curable resin composition of the present invention preferably exhibits a Young's modulus of 500 to 2,000 MPa, and more preferably 600 to 1,500 MPa. The elongation at break is preferably 5 to 50%, more preferably 15 to 40%. The breaking strength is preferably 1 to 70 MPa, more preferably 1 to 50 MPa.

The liquid curable resin composition of the present invention is suitable as a liquid curable resin composition for coating the outermost layer of an optical fiber by being cured by heat and / or radiation.
In order to form the outermost coating layer (upjacket layer), it is preferable to coat to a film thickness of 100 to 400 μm.

  EXAMPLES Next, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these Examples at all.

[Production Example 1: (A1) Synthesis of urethane (meth) acrylate 1]
In a reaction vessel equipped with a stirrer, 0.018 g of 2,6-di-t-butyl-p-cresol, 27.1 g of 2,4-tolylene diisocyanate, 23.1 g of isobornyl acrylate, and 0.061 g of dibutyltin dilaurate were added. After the addition, the mixture was cooled to 15 ° C. with stirring. 18.0 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. Then, the liquid temperature was cooled to 20 ° C., and 31.8 g of bisphenol A ethylene oxide addition diol (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 urethane (meth) acrylate be UA1-1.
The obtained urethane (meth) acrylate has a structure in which 2-hydroxyethyl acrylate is bonded to both ends of a diol having a bisphenol A structure via 2,4-tolylene diisocyanate.

[Production Example 2: (A1) Synthesis 2 of urethane (meth) acrylate]
To a reaction vessel equipped with a stirrer, 0.024 g of 2,6-di-t-butyl-p-cresol, 42.8 g of 2,4-tolylene diisocyanate, and 0.080 g of dibutyltin dilaurate were added, and while stirring, Cooled to ° C. 57.1 g of hydroxyethyl acrylate was added dropwise while controlling the liquid temperature to be 20 ° C. or lower, and the mixture was stirred at a hot water bath of 40 ° C. for 1 hour. Then, after confirming that the temperature rise was not seen, it was made to stir at 65 degreeC for 3 hours, and the reaction was complete | finished when the residual isocyanate became 0.1 mass% or less. Let the obtained urethane (meth) acrylate be UA1-2.
The obtained urethane (meth) acrylate has a structure in which 2-hydroxyethyl acrylate is bonded to both ends of 2,4-tolylene diisocyanate.

[Production Example 3: (A2) Synthesis of urethane (meth) acrylate 1]
To a reaction vessel equipped with a stirrer, 0.054 g of 2,6-di-t-butyl-p-cresol, 22.1 g of 2,4-tolylene diisocyanate and 0.016 g of dibutyltin dilaurate were added, and then stirred. And cooled to 15 ° C. 14.8 g of hydroxyethyl acrylate was added dropwise while controlling the liquid temperature to be 20 ° C. or lower, and the mixture was stirred in a hot water bath at 40 ° C. for 1 hour. Thereafter, the liquid temperature was cooled to 20 ° C., and 30.6 g of Plaxel 205 (manufactured by Daicel Chemical) 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. The obtained urethane (meth) acrylate is designated as UA2.
The obtained urethane (meth) acrylate has a structure in which 2-hydroxyethyl acrylate is bonded to both ends of a diol having a polyester polyol structure via 2,4-tolylene diisocyanate.

[Production Example 4: (A3) Synthesis of urethane (meth) acrylate 1]
In a reaction vessel equipped with a stirrer, 0.024 g of 2,6-di-t-butyl-p-cresol, 28.3 g of 2,4-tolylene diisocyanate, 52.8 g of polytetraethylene glycol having a number average molecular weight of 650 And cooled until the liquid temperature reached 15 ° C. After adding 0.080 g of dibutyltin dilaurate, the mixture was stirred for 1 hour so that the liquid temperature did not exceed 40 ° C. These were cooled with ice until the liquid temperature became 15 ° C. or lower while stirring. Thereafter, 18.8 g of hydroxyethyl acrylate was dropped while controlling the liquid temperature to be 20 ° C. or lower, and the mixture was further reacted by stirring for 1 hour. Stirring was continued for 3 hours at a liquid temperature of 70 to 75 ° C., and the reaction was terminated when the residual isocyanate became 0.1% by mass or less. Let the obtained urethane (meth) acrylate be UA3-1.
The obtained urethane (meth) acrylate has a structure in which 2-hydroxyethyl acrylate is bonded to both ends of propylene glycol via 2,4-tolylene diisocyanate.

[Production Example 5: (A3) Synthesis of urethane (meth) acrylate 2]
To a reaction vessel equipped with a stirrer, 0.26 g of 2,6-di-t-butyl-p-cresol, 271 g of 2,4-tolylene diisocyanate and 546 g of polypropylene glycol having a number average molecular weight of 700 are added, and the liquid temperature is increased. Cooled to 15 ° C. After adding 0.80 g of dibutyltin dilaurate, it was stirred for 1 hour so that the liquid temperature did not become 40 ° C. or higher. These were cooled with ice until the liquid temperature became 15 ° C. or lower while stirring. Thereafter, 181 g of hydroxyethyl acrylate was added dropwise while controlling the liquid temperature to be 20 ° C. or lower, and the mixture was further reacted by stirring for 1 hour. Stirring was continued for 3 hours at a liquid temperature of 70 to 75 ° C., and the reaction was terminated when the residual isocyanate became 0.1% by mass or less. Let the obtained urethane (meth) acrylate be UA3-2.
The obtained urethane (meth) acrylate has a structure in which 2-hydroxyethyl acrylate is bonded to both ends of propylene glycol via 2,4-tolylene diisocyanate.

Examples 1-3, Comparative Examples 1-4
Each component having the composition shown in Table 1 was charged into a reaction vessel equipped with a stirrer and stirred for 1 hour while controlling the liquid temperature at 50 ° C. to obtain a liquid curable resin composition.

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. Composition stability:
Each liquid curable resin composition was observed by visual observation immediately after preparation and after standing for 1 month in an environment at a temperature of 5 ° C. The case where the composition was transparent was designated as “◯”, and the case where turbidity was observed or phase separation was observed as “x”.

2. viscosity:
The liquid curable resin 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.

3. Young's modulus:
A liquid curable resin composition was applied on a glass plate using an applicator bar having a thickness of 250 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 determined from the tensile strength at 2.5% strain at a pulling speed of 1 mm / min.

4). Breaking strength and breaking elongation:
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 / distance between marked lines (measurement distance): 25 mm
Measurement temperature: 23 ° C
Relative humidity: 50% RH

5. Adhesion with ink layer:
A secondary material (manufactured by JSR, Desolite) is applied to the glass at a thickness of 130 μm, and 0.1 J / cm in an air atmosphere using a 3.5 kW metal halide lamp (Oak, SMX-3500 / F-OS). ^The cured film was obtained by irradiating with ultraviolet rays of ² . Thereafter, UV ink (DSM, 751 ink) was applied by a spin coater, and 1% oxygen concentration or 5% oxygen concentration using a 3.5 kW metal halide lamp (Oak, SMX-3500 / F-OS). Under the irradiation, ultraviolet rays of 0.05 J / cm ² were irradiated and cured on the secondary material with a thickness of about 10 μm. On this cured film, each liquid curable resin composition was similarly applied with a spin coater (2000 rpm, 20 seconds), and an air atmosphere using a 3.5 kW metal halide lamp (OMX, SMX-3500 / F-OS). Under the irradiation, 0.5 J / cm ² of ultraviolet rays was irradiated to obtain a multilayer cured film. 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).
Lucillin TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (manufactured by Ciba Specialty Chemicals).
Irganox 1035: 2,2'-thiodiethylbis [3- (3,5-di-tert
-Butyl-4-hydroxyphenyl) propionate (manufactured by Ciba Specialty Chemicals).
Irganox 245: ethylenebis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate] (manufactured by Ciba Specialty Chemicals).
SH28PA: dimethylpolysiloxane polyoxyalkylene copolymer (manufactured by Dow Corning Toray).
Polyester polyol (number average molecular weight 3000): poly [(3-methyl-1,5-pentanediol) -alt- (adipic acid)]; Kuraray polyol P3010 (manufactured by Kuraray).
Polyester polyol (number average molecular weight 2000): poly [(3-methyl-1,5-pentanediol) -alt- (adipic acid)]; Kuraray polyol P2010 (manufactured by Kuraray).
Polyether polyol (number average molecular weight 4000): polypropylene glycol; PPG2000 (Asahi Glass Urethane)

As is clear from Table 1, all of the resin compositions of the present invention shown in each example are excellent in stability, and the cured product formed from each composition has a high Young's modulus and a small elongation at break. Moreover, the adhesiveness with the ink layer is low and good. On the other hand, Comparative Example 1 formed by using urethane (meth) acrylate consisting only of component (A3) having a flexible structure without compounding component (A1) which is urethane (meth) acrylate having a rigid structure. Then, the Young's modulus of the cured product is low. In Comparative Example 2 that does not contain the component (C), the adhesion with the ink layer is excessive. In Comparative Example 3 in which a polyester polyol having a number average molecular weight of 2,000 was blended in place of the component (C), the Young's modulus of the cured product was low. In Comparative Example 4 in which a polyether polyol having a number average molecular weight of 4,000 was blended instead of the component (C), the compatibility of the polyether polyol was inferior to that of the component (C), so the storage stability of the liquid resin composition was lowered. did.
Therefore, the resin composition of the present invention is useful as a composition for coating the outermost layer of the optical fiber strand of the upjacket layer.

Claims (9)

The following components (A1), (A2), (B) and (C):
(A1) Urethane (meth) acrylate having a structure derived from a polyol having an aromatic structure or an alicyclic structure, and a urethane having no structure derived from a polyol, which is a reaction product of diisocyanate and a hydroxyl group-containing (meth) acrylate One or more urethane (meth) acrylates selected from (meth) acrylates,
(A2) urethane (meth) acrylate having a structure derived from polyester polyol, (B) a compound having an ethylenically unsaturated group other than urethane (meth) acrylate,
(C) A liquid curable resin composition for coating an outermost layer of an optical fiber containing a polyester polyol compound having a number average molecular weight of 3000 or more.   The outermost layer coating of an optical fiber according to claim 1, further comprising (A3) a urethane (meth) acrylate obtained by reacting an aliphatic polyol other than the polyester polyol, a diisocyanate, and a hydroxyl group-containing (meth) acrylate. Liquid curable resin composition.   The liquid curable resin for coating an outermost layer of an optical fiber according to claim 2, wherein 50 to 100% by mass of the total content of components (A1), (A2) and (A3) is component (A1). Composition.   The liquid curable resin for coating the outermost layer of the optical fiber according to any one of claims 1 to 3, wherein the component (A1) includes a urethane (meth) acrylate having a structure derived from a polyol having a bisphenol structure. Composition.   Component (B) contains component (B1) a compound having one ethylenically unsaturated group, and (meth) acrylate having an aromatic structure or alicyclic structure is added to 100% by mass of component (B1) as a whole. On the other hand, the liquid curable resin composition for outermost layer coating | cover of the optical fiber strand of any one of Claims 1-4 contained exceeding 50 mass%.   The liquid curable resin composition for coating an outermost layer of an optical fiber according to any one of claims 1 to 5, further comprising (D) a silicone compound having a number average molecular weight of 1,500 to 35,000. .   An outermost coating layer for an optical fiber obtained by curing the liquid curable resin composition according to any one of claims 1 to 6.   The outermost coating layer of an optical fiber according to claim 7, wherein the Young's modulus is 500 to 2,000 MPa.   An optical fiber having the outermost coating layer according to claim 7 or 8.