KR20070019708A - Curable liquid resin composition - Google Patents

Abstract

The present invention comprises (A) at least one branch point and at least three molecular chains having a molecular weight of at least 200 g / mol extending from the branching point, and hydroxyl at the ends of the two or more molecular chains extending from said branching point. 0.5 to 50% by weight of a urethane (meth) acrylate oligomer obtained from a polyol (a), a polyisocyanate (b) and a hydroxyl group-containing (meth) acrylate (c) having a branched structure comprising groups; (B) 5 to 90% by weight of a polymerizable organic compound; And (C) 0.1 to 10% by weight of a polymerization initiator, wherein the cured product has a Young's modulus of at least 350 MPa at 23 ° C.

Description

Curable Liquid Resin Composition {CURABLE LIQUID RESIN COMPOSITION}

FIELD OF THE INVENTION The present invention relates to curable liquid resin compositions, and more particularly to the curable liquid resin compositions suitable as coating materials, in particular secondary materials, such as secondary materials or ribbon matrix materials for optical fibers.

In the manufacture of the optical fiber, a resin coating is applied to protect and strengthen the optical fiber immediately after spinning the molten glass fibers. As a resin coating material, the structure which provided the flexible primary coating layer on the surface of glass fiber, and provided the hard secondary coating layer on the outer side of the said primary coating layer was known. In practical applications, prior to treating an optical fiber provided with a resin coating, a ribbon structure having a rectangular cross section is formed, for example, by arranging four or eight optical fibers side by side on a plane and then curing using a bundling material. . The resin composition for forming the first coating layer is called a primary material, the resin composition for forming the second coating layer is called a secondary material, and the material for bonding several optical fibers is called a ribbon matrix material.

One of the functions of the secondary material and the matrix material is that it acts as a strong protective film to prevent external loads from being applied to the primary material and quartz glass fibers in the underlying layer. Therefore, these materials are designed to have glass transition temperatures above room temperature and high modulus stiffness. However, when the secondary material or the ribbon matrix material is cured during the production process, residual stresses occur in the cured film due to cooling, shrinkage, etc., and the load may be applied to the lower layer without absorbing external loads. Applied to the primary material in the underlying layer. One of the phenomena caused by the load is to damage the primary material to create a space in the primary material and to peel the primary material from the quartz glass, which is considered to be one of the causes for the transmission loss.

As a technique for reducing the thickness of the coating layer while maintaining light transmission properties, a coated optical fiber having a specific stress-relaxation time (Japanese Patent Laid-Open No. 8-5877) and an optical fiber having improved durability (Japanese Patent Laid-Open No. 2001) -31731) has been known to provide a primary coating layer with excellent stress-relaxation properties. However, since this method does not necessarily provide a sufficiently shortened stress-relaxation time, the above technical problem remains a problem to be solved.

Polyurethane (meth) acrylates having one branch point per molecule, having (meth) acryl groups at two of the three molecular ends extending from said branch and no (meth) acryl groups at the other end A radiation-curable liquid resin composition comprising an oligomer is disclosed in Japanese Patent Laid-Open No. 2000-351818. Since the Young's modulus of the cured product obtained from such a composition at 25 ° C. is 1 MPa or less, such a composition cannot be used as a secondary material.

Accordingly, it is an object of the present invention to provide a curable liquid resin composition which can be used as a protective film, in particular a secondary material after curing, in which it forms a cured layer that generates only minor residual stresses and can easily absorb external loads. It is.

The above object can be achieved in the present invention by a curable liquid resin composition comprising the following components (A), (B) and (C):

(A) Hydro at the ends of two or more molecular chains extending from a branching point, having a structure comprising at least one branching point and three or more molecular chains extending therefrom, the molecular chains having a molecular weight of at least 200 g / mol. 0.5 to 50 weight percent of a urethane (meth) acrylate oligomer obtained from polyol (a) comprising a hydroxyl group, polyisocyanate (b), and hydroxyl group-containing (meth) acrylate (c);

(B) 5 to 90% by weight of the curable organic compound; And

(C) 0.1 to 10% by weight of polymerization initiator.

The cured product of the composition has a Young's modulus of at least 350 MPa at 23 ° C.

Since the cured product produced from the curable liquid resin composition of the present invention has a short stress-relaxation time of less than 4 minutes, the cured product does not impose a large load on the primary material. In addition, the cured product has a high Young's modulus. Therefore, the curable liquid resin composition of the present invention is useful as a secondary material and a ribbon matrix material, especially a secondary material for optical fibers.

In one embodiment of the invention, the urethane (meth) acrylate oligomer (A) is branched (a) while adjusting the molar ratio of the raw material such that the hydroxyl groups resulting from the polyol (a) can remain in the resulting oligomer Polyols having a structure (branched polyols) are obtained by reacting with (b) polyisocyanates and (c) hydroxyl group-containing (meth) acrylates. Preferably, almost all or all hydroxyl groups resulting from the polyol (a) react.

As the method for reacting these compounds, (a) branched polyols, (b) polyisocyanates and (c) hydroxyl group-containing (meth) acrylates are all reacted together; (a) reacting the branched polyol with (b) polyisocyanates and then reacting the resulting product with (c) hydroxyl group-containing (meth) acrylates; (b) reacting the polyisocyanate with (c) hydroxyl group-containing (meth) acrylate and then reacting the resulting product with (a) branched polyol; (b) reacting the polyisocyanate with (c) hydroxyl group-containing (meth) acrylate, reacting the resulting product with (a) polyol, and then producing the resulting product (c) hydroxyl group-containing (meth) ) And a method of further reacting with the acrylate.

In the reaction of these compounds, copper naphthenate, cobalt naphthenate, zinc naphthenate, di-n-butyltin dilaurate, triethylamine, 1,4-diazabicyclo [2.2.2] octane, or It is preferable to use a urethanization catalyst such as 2,6,7-trimethyl-1,4-diazabicyclo [2.2.2] octane in an amount of 0.01 to 1 parts by weight per 100 parts by weight of the total reactants. This reaction is preferably carried out at a temperature of 10 to 90 ° C, particularly preferably at a temperature of 30 to 80 ° C.

In one embodiment of the invention, the branched polyol (a) is obtained by ring-opening polymerization of glycerol or sorbitol with one or more ethylene oxide, propylene oxide or butylene oxide.

In another embodiment of the invention, the branched polyol (a) comprises at least three hydroxyl groups in situ and is preferably a relatively low molecular weight triol or tetraol, for example polyol TP30LW ( Polyols such as triols such as ethoxylated trimethylolpropane) or tetraols such as Polyol PP50 (ethoxylated pentaerythritol) (both of which are made by Neste Oxo) a ') is prepared by reacting a polyisocyanate (b), at least one other polyol (a "), preferably a diol, and a hydroxyl group-containing (meth) acrylate (c). In this embodiment, The branched polyol (a) reacts the polyol (a ') with polyisocyanates and then forms one or more other polyols (a "), preferably diols, which form a molecular chain extending from the branching point. Thereby to form. Herein, one or more other polyols (a ") may be selected from the group of polyols (" (a) and other polyols or mixtures of polyols "described below, for example as" (a2) ".

The branched polyol (a) formed above is then reacted with (b) polyisocyanates and (c) hydroxyl group-containing (meth) acrylates to form urethane (meth) acrylate oligomers (A). Thus, the branched polyol (a) of this embodiment extends from the branching point (core) formed by the polyol (a '), at least one other polyol (a "), preferably formed by a diol. Molecular chains, and reactive end groups from hydroxyl-containing (meth) acrylates, polyisocyanates link branching points (cores), molecular chains extending from the branching point and (meth) acrylate reactive groups.

Depending on the ratio between the polyol (a '), one or more other polyols (a "), preferably diols, polyisocyanates (b) and hydroxyl-containing (meth) acrylates (c), difunctional and polyfunctional ( A mixture of meth) acrylates can be formed, therefore, after forming a branched polyol (a) which forms (A) after reacting with hydroxyl-containing (meth) acrylates, the reaction mixture is still still hydroxyl-containing. It may also contain free diols (a ") which can react with (meth) acrylates to form bifunctional oligomers.

As the polyol (a ') used in this embodiment, low molecular weight polyols which are generally liquid at room temperature and therefore easy to handle during synthesis can be used. The reaction with the polyol can generally be carried out without solvent. In addition, the polyol is relatively inexpensive, and a polyol that is readily available may be used. The ratio between the type of polyol (a ') (e.g. number of hydroxyl groups, molecular weight), the type of one or more other polyols (a "), preferably the diol (e.g. molecular weight) and reactant By varying, a wide range of branched oligomers, or mixtures of branched oligomers and linear oligomers, can be produced in one container, and, according to the requirements of the oligomers, many different systems can be produced.

The molecular weight of at least three molecular chains extending from the branching point of the branched polyol (a) is preferably at least 500 g / mol, more preferably at least 700 g / mol. In one embodiment of the present invention, the molecular weight of at least three molecular chains extending from the branching point of the branched polyol (a) is preferably at least 1000 g / mol. The molecular weight of at least three molecular chains extending from the branching point of the branched polyol (a) is preferably at most 10,000 g / mol, more preferably at most 5,000 g / mol and most preferably at most 3,000 g / mol. In one embodiment of the present invention, the molecular weight of at least three molecular chains extending from the branching point of the branched polyol (a) is preferably 2,000 g / mol or less.

Although not particularly limited, the number average molecular weight of the polyol (a) is preferably 1,500 to 20,000 g / mol, more preferably 1,500 to 12,000 g / mol, most preferably 2,000 to 10,000 g / mol, particularly preferably Is 2,500 to 8,000 g / mol.

The number average molecular weight per side chain of the polyol (a) is preferably 500 to 2,000 g / mol, more preferably 1,000 to 1,500 g / mol.

Branched polyols (a) preferably have molecular chains extending from 3 to 6 branching points, more preferably molecular chains extending from 3 or 4 branching points. All molecular chains extending at least two, preferably at least three and more preferably from branching points comprise terminal hydroxyl groups.

Commercially available branched polyols capable of reacting with polyisocyanates (b) and hydroxyl group-containing (meth) acrylates (c) include Daiichi Seiyaku Co., Ltd., such as G3000. , Ltd.); SANNIX Gl-3000, SANIX GP-3000, SANIX GP-3700M, SANIX GP-4000, SANIX GEP-2800, SANIX GP-600 and SANIX GP-1000, Newpol TL -4500N etc. are mentioned. In another embodiment of the invention, apart from the polyol (a '), at least one other polyol (a "), preferably a diol, is used to form a branched polyol (a), and TP30LW (ethoxylated tri Relatively small branched polyols such as methylpropane) or tetraols such as polyol PP50 (ethoxylated pentaerythritol) (both of which are manufactured by Neste Oxo), Sonics TP-400, Sonics GP -250, Sarnix GP-400 can be used as polyol (a ') with relatively low molecular weight.

(a) and other polyols or mixtures of polyols may be added to (a). This other polyol or mixture of polyols is defined as (a2). Examples of (a2) are aliphatic or cyclic polyether diols, polycarbonate diols, and polycaprolactone diols. The polymerization method of the structural unit of such a polyol is not specifically limited. Such polyols can be any random polymer, block polymer or graft polymer. Examples of aliphatic polyether diols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyhexamethylene glycol, polyheptamethylene glycol, polydecamethylene glycol, two And polyether polyols obtained by ring-opening polymerization of the above ionic polymerizable cyclic compounds. Examples of ionically polymerizable cyclic compounds include ethylene oxide, propylene oxide, 1,2-butylene oxide, butene-1-oxide, isobutene oxide, 3,3-bischloromethyloxetane, tetrahydrofuran, 2-methyl Tetrahydrofuran, 3-methyltetrahydrofuran, dioxane, trioxane, tetraoxane, chlorohexene oxide, styrene oxide, epichlorohydrin, glycidyl methacrylate, allyl glycidyl ether, allyl glycidyl carbonate Cyclic ethers such as butadiene monooxide, isoprene monooxide, vinyl oxetane, vinyl tetrahydrofuran, vinyl cyclohexene oxide, phenyl glycidyl ether, butyl glycidyl ether, and glycidyl benzoate. Can be. Furthermore, the ionically polymerizable cyclic compounds are obtained by ring-opening polymerization with monomers such as cyclic imines such as ethyleneimine, cyclic lactone acids such as β-propiolactone and glycolic acid lactide, and dimethylcyclopolysiloxane. Polyether polyols can be used. Examples of specific combinations of two or more ionic polymerizable cyclic compounds include tetrahydrofuran and propylene oxide, tetrahydrofuran and 3-methyltetrahydrofuran, tetrahydrofuran and ethylene oxide, propylene oxide and ethylene oxide, butene-1-oxide And a combination of ethylene oxide, tetrahydrofuran, butene-1-oxide and ternary copolymer of ethylene oxide and the like. The ring-opening copolymer of such ion-polymerizable cyclic compounds may be random copolymers or block copolymers.

These polyether polyols are PTMG650, PTMG1000, PTMG2000 (manufactured by Mitsubishi Chemical Corp.), PEG1000, Unisafe DC1100, DC1800 (Nippon Oil and Fats Co., Nippon Oil and Fats Co.) , Ltd.), PPTG2000, PPTG1000, PTG400, PTGL2000 (manufactured by Hodogaya Chemical Co., Ltd.), Z-3001-4, Z-3001-5, PBG2000A , PBG2000B (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Acclaim 4200 and Acclaim 200, Desmophen 2061BD (manufactured by Bayer), and the like.

Examples of the cyclic polyether polyol include alkylene oxide addition diols of bisphenol A, alkylene oxide addition diols of bisphenol F, hydrogenated bisphenol A, hydrogenated bisphenol F, alkylene oxide addition diols of hydrogenated bisphenol A, Alkylene oxide addition diol of hydrogenated bisphenol F, Alkylene oxide addition diol of hydroquinone, Alkylene oxide addition diol of naphthohydroquinone, Alkylene oxide addition diol of anthrahydroquinone, 1,4-cyclo Hexanediol and its alkylene oxide addition diol, tricyclodecanediol, tricyclodecane dimethanol, pentacyclo pentadecanediol, pentacyclopentadedecane dimethanol, etc. are mentioned. Among them, alkylene oxide addition diols of bisphenol A, alkylene oxide addition diols of hydrogenated bisphenol A and tricyclodecanedimethanol are preferable. These polyols are Uniol DA400, DA700, DA1000, DB400 (all are manufactured by Nippon Oil & Fats Company, Limited), N1162 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), tricyclodecanedimethanol ( Manufactured by Mitsubishi Chemical Corporation).

Examples of the polyester polyols include polyester polyols obtained by reacting a polyol with a diacidic base. Examples of the polyol include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, tetramethylene glycol, polytetramethylene glycol, 1,6-hexanediol, neopentyl glycol Lycol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, and 2-methyl-1,8-octanediol. Examples of the dibasic acid include phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, adipic acid and sebacic acid. Such polyester diols are commercially available from Kurapol P-2010, PMIPA, PKA-A, PKA-A2, PNA-2000 (manufactured by Kuraray Co., Ltd.) and the like. have.

As an example of a polycarbonate polyol, the polycarbonate of polytetrahydrofuran, the polycarbonate of 1, 6- hexanediol, etc. are mentioned. Commercially available polycarbonate polyol products include DN-980, 981, 982 and 983 (manufactured by Nippon Polyurethane Industry Co., Ltd.), PC-8000 (manufactured by PPG). ), PC-THF-CD (manufactured by BASF), and the like.

Examples of polycaprolactone diols include ε-caprolactone and diols such as ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, tetramethylene glycol and polytetramethylene Obtained by reacting glycol, 1,2-polybutylene glycol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol and 1,4-butanediol Polycaprolactone diol is mentioned. Such diols are commercially available from PLACCEL 205, 212, 212AL, 220AL (manufactured by Daicel Chemical Industries, Ltd.) and the like.

Many other polyols (a2) than those illustrated above can be used. Examples of such other polyols include ethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol , Dimethylol compound of dicyclopentadiene, tricyclodecanedimethanol, β-methyl-δ-valerolactone, hydroxy-terminated polybutadiene, hydroxy-terminated hydrogenated polybutadiene, castor oil- Modified polyols, diol-terminated compounds of polydimethylsiloxane, polydimethylsiloxane carbitol-modified diols, and the like.

In addition to the combined use of polyols, diamines may be used with the polyols. Examples of the diamine include ethylenediamine, tetramethylenediamine, hexamethylenediamine, p-phenylenediamine, 4,4'-diaminodiphenylmethane, diamines containing hetero atoms, and polyether diamines. Etc. can be mentioned.

Of the above polyols (a2), polyether diols, alkylene oxide addition diols of bisphenol A and alkylene oxide addition diols of hydrogenated bisphenol A are preferred. These diols are PTMG650, PTMG1000, PTMG2000 (manufactured by Mitsubishi Chemical Corporation), Uniol DA400, DA700, DA1000, DB400 (all of which are manufactured by Nippon Oil & Fats Company, Limited), and N1162 (Daiichi Kogyo Seiyaku Campa) (Manufactured by Nippon Limited).

The number average molecular weight of this other polyol component (a2) is 300-5,000, Preferably it is 300-2,000, More preferably, it is 300-1,000.

As polyisocyanate of component (b), diisocyanate is preferable. Examples of the diisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylene diisocyanate, 1,4-xylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 3,3'-dimethyl-4,4'- diphenylmethane diisocyanate, 4,4'- diphenylmethane diisocyanate, 3,3'-di Methylphenylene diisocyanate, 4,4'-biphenylene diisocyanate, 1,6-hexane diisocyanate, isophorone diisocyanate, methylenebis (4-cyclohexyl isocyanate), 2,2,4-trimethylhexamethylene Diisocyanate, bis (2-isocyanate ethyl) fumarate, 6-isopropyl-1,3-phenyl diisocyanate, 4-diphenylpropane diisocyanate Lysine, lysine diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylene diisocyanate, tetramethylxylene diisocyanate, 2,5 (or 6) -bis (isocyanatemethyl) -bicyclo [2.2.1] Heptane and the like. Among these, 2,4-tolylene diisocyanate, isophorone diisocyanate, xylene diisocyanate, and methylenebis (4-cyclohexyl isocyanate) are especially preferable.

These polyisocyanates (b) can be used individually or in combination of two or more.

Examples of the hydroxyl group-containing (meth) acrylate (c) include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2 -Hydroxy-3-phenyloxypropyl (meth) acrylate, 1,4-butanediol mono (meth) acrylate, 2-hydroxyalkyl (meth) acryloyl phosphate, 4-hydroxycyclohexyl (meth ) Acrylate, 1,6-hexanediol mono (meth) acrylate, neopentyl glycol mono (meth) acrylate, trimethylolpropane di (meth) acrylate, trimethylolethane di (meth) acrylic And latex, pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, and (meth) acrylates represented by the following formulas (1) and (2):

Where

R ¹ represents a hydrogen atom or a methyl group,

n is an integer from 1 to 15.

In addition, compounds obtained by addition reaction of (meth) acrylic acid with a compound containing a glycidyl group such as alkyl glycidyl ether, allyl glycidyl ether, or glycidyl (meth) acrylate may be used as a hydroxyl group- It may also be used as a containing (meth) acrylate. Of these (meth) acrylates containing hydroxyl groups, 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate are particularly preferred.

Such hydroxyl group-containing (meth) acrylates (c) may be used individually or in combination of two or more.

In one embodiment of the invention, urethane (i.e., nearly all, preferably all, hydroxyl groups resulting from polyol (a) react with diisocyanates (b) and hydroxyl group-containing (meth) acrylates (c). The molar ratio of the raw material is adjusted during the preparation of the meth) acrylate oligomer (A). In this embodiment, only a small amount of hydroxyl groups may remain.

In another embodiment of the invention, a portion of the hydroxyl groups resulting from the polyol (a) do not react with the diisocyanate (b) and the hydroxyl group-containing (meth) acrylate (c) and still do not react with the oligomer (A) It is desirable to adjust the molar ratio of the raw material to remain as hydroxyl groups in it.

The urethane (meth) acrylate of component (A) is added to the curable liquid resin composition of the present invention in an amount of 0.5 to 50% by weight, preferably 3 to 45% by weight, more preferably 5 to 40% by weight. If the content is less than 0.5% by weight, the coating ability may be impaired. If the content exceeds 50% by weight, the Young's modulus of the cured product decreases. In one embodiment of the present invention, the urethane (meth) acrylate oligomer (A) is added as a main component of the total amount of urethane (meth) acrylate oligomer in the curable liquid resin composition.

In another embodiment of the present invention, the urethane (meth) acrylate oligomer (A) is added as a modifier of the main component of the urethane (meth) acrylate oligomer, for example as a flow modifier. It is an object of this embodiment to provide a curable liquid resin composition, in particular a secondary resin composition, having improved processability. Today's methods of making coated optical fibers include passing the fibers through a coating die installed in an apparatus known as a draw tower and then curing the applied resin composition. In wet-on-wet applications, the secondary resin composition is applied to the optical glass fibers simultaneously with the primary resin composition, and then these two compositions are cured simultaneously. Typically, the flow characteristics of the primary resin composition and the secondary resin composition are different from each other, that is, the composition is characterized by limited flow miscibility. This can cause certain problems. Drag flow induced by moving fibers at high draw rates typically results in high shear rates at locations adjacent to the outlet of the coated cup. Optical fiber resin compositions generally exhibit complex non-Newtonian behavior as the shear rate increases. For this reason, processability instability sometimes occurs during fabrication of fibers, especially when applying the primary resin composition and the secondary resin composition having different flow characteristics in wet applications. Another important issue concerns the uniformity of the coating after curing. More specifically, in high quality coated fibers, the thickness of the coating layer has a high uniformity along the length of the fibers. However, at high speeds, typically above about 25 m / sec, high fiber speeds, relatively small clearance between the outer surface of the fiber and the die, die length, pressure and pressure applied on the composition as it feeds into the die Combinations of the properties of the cured coating composition may result in unacceptably low levels of uniformity in the cured coating. Optical fibers with low levels of coating uniformity can present problems when it is necessary to join two optical fibers together. Non-uniformity can also be interpreted as a data transmission problem, eg, signal attenuation, if installed in a data network. One means of addressing processing instability is to control the flow characteristics of the curable liquid secondary resin composition in some manner.

In this embodiment, when the urethane (meth) acrylate oligomer (A) is added as a modifier, for example a flow modifier, the main component of the urethane (meth) acrylate oligomer is preferably a diol-based urethane (meth) In the case of liquid acrylates, urethane (meth) acrylate oligomers (A) are added in an amount of, for example, 0.5 to 10% by weight in order to obtain more favorable fluidity characteristics. In an embodiment of the present invention, when urethane (meth) acrylate oligomer (A) is added as a flow modifier, the steady state compliance (J _e ), which is a measure of the elastic modulus of the resin, is preferably at least 2 MPa ⁻¹ More preferably at least 3 MPa- ¹ , most preferably at least 4 MPa- ¹ , particularly preferably at least 5 MPa- ¹ .

The urethane (meth) acrylate obtained by reacting 1 mol of diisocyanate with 2 mol of (meth) acrylate containing a hydroxyl group can be added to the curable liquid resin composition of the present invention. Examples of such urethane (meth) acrylates are the reaction products of hydroxyethyl (meth) acrylate and 2,4-tolylene diisocyanate, hydroxyethyl (meth) acrylate and 2,5 (or 6) Reaction product of -bis (isocyanatemethyl) -bicyclo [2.2.1] heptane, reaction product of hydroxyethyl (meth) acrylate and isophorone diisocyanate, hydroxy propyl (meth) acrylate and 2,4- Reaction products of tolylene diisocyanate and reaction products of hydroxypropyl (meth) acrylate and isophorone diisocyanate.

The polymerizable monofunctional compound is blended with the curable liquid resin composition of the present invention as component (B). Examples of monofunctional compounds include lactams containing isogroups such as N-vinylpyrrolidone, N-vinylcaprolactam, isobornyl (meth) acrylate, bonyl (meth) acrylate, tricyclodecanyl (meth (Meth) acrylate, benzyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, acryloyl morpholine, containing alicyclic structures such as) acrylate and dicyclopentanyl (meth) acrylate, Vinyl imidazole, vinyl pyridine, 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- Tyl (meth) acrylate, pentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylic Latex, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, Lauryl (meth) acrylate, Stearyl (meth) acrylate, Isostearyl (meth) acrylate, Tetrahydrofuranyl (meth) acrylate, Butoxyethyl (meth) acrylate, Ethoxydiethylene Lycol (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, Methoxyethylene glycol (meth) acrylate, ethoxyethyl (meth) acrylate, methoxypolypropylene glycol (meth) acrylate, diacetone (meth) acrylamide, isobutoxymethyl (meth) acrylic Amide, 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 general formulas (3) to (6):

Where

R ² represents a hydrogen atom or a methyl group,

R ³ represents an alkylene group having 2 to 6, preferably 2 to 4 carbon atoms,

R ⁴ represents a hydrogen atom or an alkyl group having 1 to 12, preferably 1 to 9 carbon atoms,

m is an integer from 0 to 12, preferably 1 to 8;

Where

R ⁵ represents a hydrogen atom or a methyl group,

R ⁶ represents an alkylene group having 2 to 8, preferably 2 to 5 carbon atoms,

R ⁷ represents a hydrogen atom or a methyl group,

p is preferably an integer from 1 to 4;

Where

R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ individually represent a hydrogen atom or a methyl group,

q is an integer of 1-5.

Among these monofunctional compounds (B), lactams containing isogroups such as N-vinylpyrrolidone, N-vinyl caprolactam, isobornyl (meth) acrylate, lauryl acrylate, and the above formula (6) Compounds of are preferred.

Such monofunctional compounds (B) are made from IBXA (manufactured by Osaka Organic Chemical Industry Co., Ltd.), Aronix M-111, M-113, M-114 , M-117, TO-1210 and Aronix M-110 (both manufactured by Toagosei Co., Ltd.).

In view of reducing the stress relaxation time, the amount of the polymerizable monofunctional compound (B) in the curable liquid resin composition of the present invention is preferably 5 to 90% by weight, more preferably 10 to 80% by weight.

Curable liquid resin composition of this invention contains a polymerization initiator as a component (C). As the polymerization initiator, a thermal polymerization initiator or a photoinitiator may be used.

When heat is used to cure the curable liquid resin composition of the present invention, a thermal polymerizable initiator such as a peroxide or an azo compound is used. Specific examples of such thermal polymerization initiators include benzoyl peroxide, t-butyloxybenzoate, and azobisisobutyronitrile.

When curing the curable liquid resin composition of this invention using a light ray, a photoinitiator is used. Also, if desired, a photosensitizer is preferably added. Examples of the photoinitiator 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 ketone, benzoin propyl ether, benzoin ethyl ether, Benzyl dimethyl ketal, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1-one, 2-hydroxy-2-methyl-1-phenylpropane-1-one, thioxanthone , Diethyl thioxanthone, 2-isopropyl thioxanthone, 2-chlorothioxanthone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one , 2,4,6-trimethylbenzoyl diphenylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide; IRGACURE 184, 369, 651, 500, 907, CGI 1700, CGI 1750, CGI 1850, CG24-61, all of which are manufactured by Ciga Specialty Chemicals Co .; Lucirin LR8728 (manufactured by BASF); Darocure 1116, 1173 (made by Merck), Ubecryl P36 (made by UCB), etc. are mentioned. Examples of photosensitizers include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate; Ubecryl P102, 103, 104, 105 (all of which are manufactured by UCB) are mentioned.

When curing the curable liquid resin composition of the present invention using both heat and ultraviolet rays, a thermal polymerization initiator and a photoinitiator may be used together. The polymerization initiator (C) is preferably used in the curable liquid resin composition of the present invention in an amount of 0.1 to 10% by weight, more preferably 0.5 to 7% by weight.

A polymerizable multifunctional compound may further be included in the curable liquid resin composition of the present invention as component (D). Examples of the polyfunctional compound (D) include trimethylolpropane tri (meth) acrylate, trimethylolpropanetrioxyethyl (meth) acrylate, pentaerythritol tri (meth) acrylate, and ethylene glycol di (meth). ) Acrylate, triethylene glycol diacrylate, tetraethylene glycol di (meth) acrylate, tricyclodecanediyldimethanol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, tripropylene glycol di (meth) acrylic Latex, neopentyl glycol di (meth) acrylate, terminal (meth) acrylic acid addition compound of bisphenol A diglycidyl ether, pentaerythritol tri (meth) Acrylate, pentaerythritol tetra (meth) acrylate, polyester di (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, tris (2-hydroxyethyl) eye Sociaurate di (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, ethylene oxide or bisphenol A di (meth) acrylate of dipropylene oxide, ethylene oxide or propylene of hydrogenated bisphenol A Epoxy (meth) acrylate produced by adding (meth) acrylate to the di (meth) acrylate of oxide addition diol, the diglycidyl ether of bisphenol A, triethylene glycol diether ether, etc. are mentioned. have.

Among these polymerizable polyfunctional compounds (D), tricyclodecanediyldimethanol di (meth) acrylate, di (meth) acrylate of ethylene oxide addition diol of bisphenol A, and tris (2-hydroxyethyl) Isocyanurate tri (meth) acrylate is preferred.

Commercially available products of such a polymerizable multifunctional compound (D) include Yupimer UV, SA-1002 (manufactured by Mitsubishi Chemical Corporation), Aaronics M-215, M-315, M-325, TO -1210 (all of which are manufactured by Toagosei Co., Ltd.) and GX-8345 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

Such polymerizable multifunctional compound (D) is preferably added to the curable liquid resin composition of the present invention in an amount of 5 to 90% by weight, particularly preferably 10 to 80% by weight. If the amount thereof is less than 5 wt% or more than 90 wt%, the coating may become uneven as the application form changes.

As long as the properties of the composition are not adversely affected, the curable liquid resin composition of the present invention may optionally include an antioxidant, a colorant, a UV absorber, a light stabilizer, a silane coupling agent, a thermal polymerization initiator, a leveling agent, a surfactant, Various additives can be added, such as preservatives, plasticizers, lubricants, solvents, fillers, anti-aging agents, wettability improvers and coating surface improvers.

The curable liquid resin composition of the present invention is cured using heat or radiation. Radiation as used herein refers to infrared rays, visible light, ultraviolet light, X-rays, electron beams, α-rays, β-rays, γ-rays, and the like.

The cured product of the curable liquid resin composition prepared according to the method described above has a stress relaxation time of less than 4 minutes, preferably 3 minutes or less, more preferably 2 minutes or less. When the stress relaxation time is 4 minutes or more, problems such as the formation of pores may occur when the coating stress remains during the fabrication or handling of the fiber and the primary layer is peeled off from the primary glass and from the quartz glass.

The cured product has a Young's modulus of at least 350 MPa, preferably at least 400 MPa, more preferably at least 500 MPa at 23 ° C.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to these examples. In the examples, “parts” refers to “parts by weight”.

Synthesis Example (A-1)

A reaction vessel equipped with a stirrer was charged with 6.651 g of isophorone diisocyanate, 0.024 g of 2,6-di-t-butyl-p-cresol, 0.080 g of dibutyltin dilaurate, and 0.008 g of phenothiazine Filled. The mixture was cooled to 10 ° C. or less using ice with stirring. After 6.651 g of hydroxyethyl acrylate was added dropwise, the mixture was reacted with stirring for 1 hour while controlling the temperature to 20 ° C. or lower. After adding 89.763 g of polypropylenetriol (G3000 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) having a number average molecular weight of 6,000, the mixture was stirred at 70 to 75 ° C for 3 hours. The reaction was terminated when the isocyanate residual concentration became 0.1% by weight or less. The liquid resin thus produced is referred to as "oligomer (A-1)".

Synthesis Example (A-2)

A reaction vessel equipped with a stirrer was charged with 16.489 g of isophorone diisocyanate, 0.024 g of 2,6-di-t-butyl-p-cresol, 0.080 g of dibutyltin dilaurate, and 0.008 g of phenothiazine Filled. The mixture was cooled to 10 ° C. or less using ice with stirring. After adding 8.666 g of hydroxyethyl acrylate dropwise, the mixture was allowed to react with stirring for 1 hour while controlling the temperature to 20 ° C. or lower. 74.633 g of a ring-opened diol (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) of tetrahydroxyfuran having a number average molecular weight of 2,000 were added, and then the mixture was stirred at 70 to 75 ° C for 3 hours. The reaction was terminated when the isocyanate residual concentration became 0.1% by weight or less. The liquid resin thus produced is referred to as "oligomer (A-2)".

Synthesis Example (U-1)

A reaction vessel equipped with a stirrer was charged with 44.726 g of isophorone diisocyanate, 0.024 g of 2,6-di-t-butyl-p-cresol, 0.080 g of dibutyltin dilaurate, and 0.008 g of phenothiazine Filled. The mixture was cooled to 10 ° C. or less using ice with stirring. After 35.063 g of hydroxyethyl acrylate was added dropwise, the mixture was allowed to react with stirring for 1 hour while controlling the temperature to 20 ° C. or lower. After adding 20.099 g of ethylene oxide addition diol (manufactured by NOF Corporation) of bisphenol A having a number average molecular weight of 400, the mixture was stirred at 70 to 75 ° C for 3 hours. The reaction was terminated when the isocyanate residual content became 0.1% by weight or less. The liquid resin thus produced is referred to as "oligomer (U-1)".

Synthesis Example (B-1)

A reaction vessel equipped with a stirrer was charged with 5.287 g of 2,4-tolylene diisocyanate, 0.024 g of 2,6-di-t-butyl-p-cresol, 0.080 g of dibutyltin dilaurate, and 0.008 g of Filled with phenothiazin. The mixture was cooled to 10 ° C. or less using ice with stirring. After 3.525 g of hydroxyethyl acrylate was added dropwise, the mixture was allowed to react with stirring for 1 hour while controlling the temperature to 20 ° C. or lower. 91.076 g of polypropylenetriol (G3000 manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) having a number average molecular weight of 6,000 was added, and then the mixture was stirred at 70 to 75 ° C for 3 hours. The reaction was terminated when the isocyanate residual concentration became 0.1% by weight or less. The liquid resin obtained in this manner is called "oligomer (B-1)".

Synthesis Example (B-2)

A reaction vessel equipped with a stirrer was loaded with 13.480 g of 2,4-tolylene diisocyanate, 0.024 g of 2,6-di-t-butyl-p-cresol, 0.080 g of dibutyltin dilaurate, and 0.008 g of Filled with phenothiazin. The mixture was cooled to 10 ° C. or less using ice with stirring. After 8.990 g of hydroxyethyl acrylate was added dropwise, the mixture was allowed to react with stirring for 1 hour while controlling the temperature to 20 ° C. or lower. After adding 77.420 g of a ring-opening polymer of tetrahydroxyfuran having a number average molecular weight of 2,000 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), the mixture was stirred at 70 to 75 ° C. for 3 hours. The reaction was terminated when the isocyanate residual concentration became 0.1% by weight or less. The liquid resin obtained in this manner is called "oligomer (B-2)".

Synthesis Example (U-2)

A reaction vessel equipped with a stirrer was charged with 42.806 g of 2,4-tolylene diisocyanate, 0.024 g of 2,6-di-t-butyl-p-cresol, 0.080 g of dibutyltin dilaurate, and 0.008 g of Filled with phenothiazin. The mixture was cooled to 10 ° C. or less using ice with stirring. 57.082 g of hydroxyethyl acrylate was added dropwise while controlling the temperature below 20 ° C, and the mixture was stirred at 70 to 75 ° C for 3 hours. The reaction was terminated when the isocyanate residual content became 0.1% by weight or less. The liquid resin obtained in this manner is called "urethane acrylate (U-2)".

Synthesis Example (U-3)

A reaction vessel equipped with a stirrer was used with 42.15 g of 2,4-tolylene diisocyanate, 0.024 g of 2,6-di-t-butyl-p-cresol, 0.080 g of dibutyltin dilaurate, and 0.008 g of Filled with phenothiazin. The mixture was cooled to 10 ° C. or less using ice with stirring. 43.48 g of hydroxyethyl acrylate and 14.26 g of hydroxyethyl propyl acrylate were added dropwise while controlling the temperature below 20 ° C., and then the mixture was stirred at 70 to 75 ° C. for 3 hours. The reaction was terminated when the isocyanate residual content became 0.1% by weight or less. The liquid resin obtained in this way is called "urethane acrylate (U-3)".

Test Example

Preparation of Test Film: The curable liquid resin composition was applied to the glass plate with a thickness of 250 μm using an applicator bar. Ultraviolet rays in the air were irradiated at a dose of 1 J / cm 2 to cure the curable liquid resin composition to obtain a test film.

1. Measurement of Young's modulus of elasticity: The test film was cut into strip-shaped samples having a width of 6 mm and a length of 25 mm. The samples were subjected to a tensile test at a temperature of 23 ° C. and 50% humidity. The Young's modulus was calculated from the tensile strength at a strain rate of 2.5% and a tensile speed of 1 mm / min.

2. Measurement of stress relaxation time: The test film was cut into strip-shaped samples having a width of 6 mm and a length of 25 mm. 5% strain was applied to the sample at a rate of 1,000 mm / min at a temperature of 23 ° C. and a humidity of 50%. The cross head of the tensile tester (Autograph AGS-50G manufactured by Shimazu Corp.) was paused to monitor the change in stress. The period during which the stress was reduced to 37% of the initial stress was measured as the stress relaxation time.

3. Observation of pore generation in the primary material:

3-1 Preparation of Primary Coating Material

A reaction vessel equipped with a stirrer was prepared with 6.6 parts 2,4-tolylene diisocyanate, 0.015 parts 2,6-di-t-butyl-p-cresol, 0.48 parts dibutyltin dilaurate, 0.005 parts phenothiazine, and 16.2 parts of IBXA (Osaka Organic Chemical Industries, Ltd.). The mixture was cooled to 10 ° C. or less using ice with stirring. After adding 2.9 parts of hydroxyethyl acrylate dropwise, the mixture was allowed to react with stirring for 1 hour while controlling the temperature to 20 ° C. or lower. After adding 50.0 parts of polytetramethylene glycol (manufactured by Mitsubishi Chemical Corporation) having a number average molecular weight of 2,000, the mixture was stirred at 50 to 60 ° C for 4 hours. The reaction was terminated when the isocyanate residual content became 0.1% by weight or less. 10.8 parts isobornyl acrylate (manufactured by Rohm and Haas Japan KK), 4.8 parts vinylcaprolactam, 5.6 parts lauryl acrylate, and 0.2 parts Irganox 1035 After addition (manufactured by Ciba-Geigy Limited), the resulting mixture was stirred at 40-50 ° C. for 30 minutes. After adding 0.1 part of diethylamine while controlling the temperature to 30 to 40 ° C, the mixture was stirred for 30 minutes. Subsequently, 1 part bis- (2,6-methoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide and 1 part Darocure 1173 (manufactured by Merck) were controlled while controlling the temperature to 50 to 60 ° C. After the addition, the mixture was stirred until a homogeneous clear liquid was obtained. The primary coating material was obtained in this way.

3-2 fiber drawing

The primary coating material was applied to the glass fibers using an optical fiber stretching device (manufactured by Yoshida Kokyo Co., Ltd.) and then cured. The compositions of the Examples and Comparative Examples were applied to the cured primary material.

Optical fiber drawing conditions were as follows: The diameter of the glass fiber was 125 micrometers. The primary coating material was applied with a metal line so that the diameter of the optical fiber after curing was 200 m, and then cured. The compositions of Examples and Comparative Examples were applied to the primary materials formed above so that the diameter after curing was 250 μm. As a UV irradiation apparatus, the UV lamp "SMX 3.5kw" manufactured by ORC Corporation was used. Applicability was evaluated at an optical fiber drawing speed of 1,000 m / min.

3-3 Observation of pore outbreak

After the fiber was immersed in hot water at 60 ° C. for 72 hours, pore formation in the primary material was observed using a microscope, and peeling of the primary material from the quartz glass was visually observed.

evaluation

Samples having a Young's modulus of 350 MPa or more and a stress relaxation rate of less than 4 minutes and no pores were evaluated as acceptance products.

As evident from Tables 1 and 2 above, the resin compositions of the Examples exhibited high stress relaxation rates and satisfactory Young's modulus as secondary materials, which resulted in the formation of pores in the primary material and from quartz glass. It shows that there are no defects such as peeling of the primary material.

Synthesis of mixtures of di-, tri- and / or tetra-functional urethane acrylate oligomers from triols and diols or tetraols and diols

Irganox 1035 (0.09 wt.%), Isophorene diisocyanate (IPDI) and dibutyltin dilaurate (DBTDL, 0.05 wt.%) Were added to the reactor with dry air, stirred and cooled to 10 ° C. Then triol TP30 LW (ethoxylated trimethylolpropane with 629 OH number of Neste oxo) or tetraol polyol PP50 (ethoxylated pentaerythritol with 638 water of 638 from Neste oxo) The reactor was stirred at 10 ° C. for 1 hour. Subsequently, 2-hydroxyethyl acrylate (HEA) was added via a dropping funnel at 10 ° C. After approximately 1 hour, the midpoint was reached, after which the reactor was heated to 20 ° C. Subsequently, diol desmophene 2061BD (Mw = 2000 g / mol polypropylene glycol, OH water 56.6, manufactured by Bayer) was added, and then the reaction mixture was heated to 80 ° C. The reaction was performed until the NCO content became 0.05% or less. Polyols and diols, IPDI and HEA were added in stoichiometric amounts.

Table 3 lists oligomers prepared using this method. Table 4 shows a coating composition comprising not only the molecular weight of these oligomers, but also 48.5% by weight of the oligomer mixture resulting from the synthesis in Table 3, 48.5% by weight of ethoxylated nonylphenol acrylate (ENPA) and 3% by weight of Irgacure184. The steady state compliance J _{e of} is shown. J _e of the measurement method is as follows:

Steady State Compliance (J _e ) Measurement

Measuring instrument and measuring method

Steady state compliance (J _e ) was determined from dynamic mechanical measurement methods. These dynamic mechanical experiments include Rheometric with dual range 200-2000 _g ^* cm _f rebalance torque transducer, 25 mm Invar parallel plate geometry, nitrogen gas oven, and liquid nitrogen cooling equipment. Scientific) (now TA Instruments) using an ARES-LS flow meter. At the beginning of the experiment, the resin sample was loaded between parallel plate geometries of the flow meter at room temperature. The interplate distance was set to 1.6 mm. After closing the gas oven, the sample was purged with nitrogen gas for about 5 minutes.

20 at a temperature interval of 5 ° C. until the sample is stiff enough to be measured against the measuring instrument (in the case of cited examples, this limit typically passes between about −20 ° C. to about −30 ° C.). The experiment was carried out by isothermal frequency sweeping using angular frequencies (three frequencies per ten, measured in decreasing order) between 100 and 0.1 rad / s starting at 5 ° C. and lowering the temperature by 5 ° C. in each step. . It should be noted that the applied strain is in the linear viscoelastic range. Representative values for strain size at room temperature are about 20-40%, decreasing to values as low as 0.01-0.02% at the lowest temperatures. Dynamic modulus (G ^* = (G ' ² + G " ² ) ^0.5 ) and phase angle (δ) were collected as a function of angular frequency. The tangent of phase angle (tanδ) was negative (due to noise) Data points with values are removed from the set values.

Fabrication of master-curves through temperature-time superposition

The results of the frequency sweeps collected at various temperatures T (phase modulus δ as a function of dynamic modulus G ^* and angular frequency ω) can be found in Ferry's book (Viscoelastic properties of polymers) (1980), John Wiley & Sons Inc.) binds in a master-curve via so-called time-temperature superposition. As the reference temperature T _ref , 20 ° C. was selected. For this purpose, a commercially available liquidity data analysis software package IRIS, developed by Winter et al., Was used.

Dynamic properties measured at low temperatures (T) were shifted to higher frequencies and linked to data collected at reference temperature (T _ref ). The horizontal shift factor a _T was measured by moving the curve of phase angle and dynamic modulus along the logarithmic frequency axis according to equations 1 and 2 below:

It was noted that good overlap of the curves of phase angle δ and dynamic modulus G ^* was obtained simultaneously. In general, this is possible in the case of the material according to the invention. A commonly used but optional, vertical shift factor b _T along the viscosity axis was not allowed in this work.

Extraction of Steady State Compliance

In order to extract steady state compliance, the dynamic master curves were refloated in different formats. Storage compliance J '(= G' / G ^{* 2} ) and loss compliance J "(= G" / G ^{* 2} ) were plotted as a function of angular frequency. IRIS ^TM and Rheometric Scientific rheometer control software orchestrator ^TM (available from IRIS Development, Amherst Elm Street 14, MA, USA 01002-2007) (Orchestrator ^TM ) were all used for data transformation. Mathematical details were available from Perry's book (JD Ferry, 'Viscoelastic properties of polymers' (1980), John Wiley & Sons Inc.).

The curve of storage compliance typically exhibits a plateau at low angular frequencies, but may represent noise. Therefore, it should be noted that data at too low a frequency is not included in the analysis. Data points at frequencies lower than the tangent (tanδ) of the phase angle above 100 are removed from the master curve, because the flowmeter has an accurate value of the storage compliance if the loss compliance is more than 20 times greater than the storage compliance. Because it can not be measured. The planar range of storage compliance J 'is typically found at angular frequencies of 500 to 2000 rad / s.

In order to remove noise from the data, we extracted the value of steady state compliance through the following procedure. Software Package IRIS (trade name) Version 7 is used to calculate the relaxation time spectrum from the master curve, which is an extremely conservative model by Winter et al. (Winter HH, Baumgartel M., Soskey P., 1993, 'A parsimonious model for viscoelastic Liquids). and solids ', in AA Collyer Ed.'Techniques in Rheological Measurement', Chapman & Hall, London). For embodiments in this application, typically less than one relaxation time per ten frequencies of the master curve is used. As the output of this spectral calculation, values for zero shear viscosity and steady state compliance are obtained. The precision of steady state compliance measured according to this method is typically ± 10%.

The data in Table 4 above shows that the Mw of the oligomer (or mixture of oligomers) depends on the number of molecular chains extending from the branch point in the polymer and the molar ratio of bifunctional: trifunctional or difunctional: tefunctional.

The results in Table 4 above show that the steady state compliance (J _e ), which is a measure of the elasticity of the liquid composition, increases as the amount of trifunctional / tetrafunctional oligomer in the composition increases (J _e through 100: 0 and from 85:15 to 50: 50 difunctional: increases to trifunctional / tetrafunctional), and increases with the number of molecular chains extending from the branching point (J _e is higher in the case of mixtures with tetrafunctional oligomers). Elasticity is an important parameter, in particular for secondary resin compositions, sometimes higher J _e improves wet processability.

Claims (22)

(A) a branch comprising at least one branch point and at least three molecular chains having a molecular weight of at least 200 g / mol extending from the branching point and comprising hydroxyl groups at the ends of the at least two molecular chains extending from the branching point 0.5 to 50% by weight of a urethane (meth) acrylate oligomer obtained from a polyol (a), a polyisocyanate (b) and a hydroxyl group-containing (meth) acrylate (c) having a structure; (B) 5 to 90% by weight of a polymerizable organic compound; And (C) 0.1 to 10% by weight of polymerization initiator Wherein the cured product has a Young's modulus of at least 350 MPa at 23 ° C., the curable liquid resin composition. The method of claim 1, Curable liquid resin composition in which each molecular chain extending from the branching point of (a) comprises a hydroxyl group. The method of claim 1, Curable liquid resin composition whose molecular chain has a molecular weight of 500 g / mol or more. (A) Polyols, polyisocyanates and hydroxyls having a branched structure and having a side chain having hydroxyl groups at the end of each branched molecular chain (hereinafter referred to as side chain) and having a number average molecular weight of 500 to 2,000 5 to 45 weight percent urethane (meth) acrylate oligomers containing hydroxyl groups resulting from polyols, obtained from group-containing (meth) acrylates; (B) 5 to 90% by weight of a polymerizable monofunctional compound; And (C) 0.1 to 10% by weight of polymerization initiator Curable liquid resin composition comprising a. The method according to any one of claims 1 to 4, Curable liquid resin composition in which the cured product has a Young's modulus of 500 MPa or more at 23 ° C. The method according to any one of claims 1 to 5, Curable liquid resin composition wherein the stress-relaxation time of the cured product is less than 4 minutes. The method according to any one of claims 1 to 6, Curable liquid resin composition having steady state compliance J _e of 2 MPa ⁻¹ or more. The method according to any one of claims 1 to 7, The curable liquid resin composition in which the polyol (a) of component (A) has 3 to 6 molecular chains extending from the branching point, and at least two of the molecular chains extending from the branching point comprise hydroxyl groups. The method according to any one of claims 1 to 8, Curable liquid resin composition further containing (A) and one or more urethane (meth) acrylates. The method of claim 9, Curable liquid resin composition wherein at least one additional urethane (meth) acrylate is a urethane (meth) acrylate oligomer based on a diol. The method according to any one of claims 1 to 10, A curable liquid resin composition which is a curable liquid secondary coating composition, a curable liquid ink material or a curable liquid matrix material. Use of the curable liquid resin composition according to any one of claims 1 to 11 as a secondary coating composition, ink composition or matrix material for coating optical glass fibers. A cured product obtained by curing the curable liquid resin composition according to claim 1. Coated optical fiber including glass optical fiber with primary coating, glass optical fiber with coated optical fiber including primary fiber and glass optical fiber with secondary coating, primary coating, secondary coating and upjacketing coating A coated optical fiber comprising a coated optical fiber comprising a coated optical fiber, a glass optical fiber and a single coating, a coated optical fiber comprising a glass optical fiber, a single coating and a top protective coating, a coated fiber having an ink composition applied thereon, and 10. An optical fiber ribbon comprising at least two coated optical fibers and optionally ink coated optical fibers, wherein at least one of the coating or composition is derived from a radiation-curable composition as described in any one of claims 1 to 9. Fiber optic. Reacting a polyol (a ') comprising at least three hydroxyl groups with a polyisocyanate (b) and one or more other polyols (a "), wherein the polyol (a') forms a branching point of the branched polyol One or more other polyols (a ") form a molecular chain extending from the branching point, and the polyisocyanates link one or more molecular chains extending from the branching point and three or more molecular chains extending from the branching point. And a hydroxyl group at the end of at least two molecular chains extending from the branching point. The method of claim 15, Wherein the molecular weight of the at least three molecular chains extending from the branch point is at least 200 g / mol. The method according to claim 15 or 16, Another polyol is a diol. The method according to any one of claims 15 to 17, A process for producing a branched polyol comprising three or four molecular chains extending from branching points. Branched polyols obtainable by the process according to any one of claims 15 to 18. A urethane (meth) acrylate oligomer which further reacts the branched polyol according to claim 19 with polyisocyanates (b) and hydroxyl group-containing (meth) acrylates (c) to form urethane (meth) acrylate oligomers. Manufacturing method. A urethane (meth) acrylate oligomer obtainable by the process of claim 20. A polyol having a branched structure comprising at least one branching point and at least three molecular chains having a molecular weight of at least 200 g / mol extending from the branching point and having hydroxyl groups at the ends of the at least two molecular chains extending from the branching point (a ), As a rheology modifier of urethane (meth) acrylate oligomers obtained from polyisocyanates (b) and hydroxyl group-containing (meth) acrylates (c).