JP2002206010A - Curing composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorine-based, actinic energy radiation-curing composition which has a low refractive index, high strength and high durability at the same time, and which is useful in various optical usages and has excellent transparency. SOLUTION: The actinic energy radiation-curing composition contains a monomer (A) expressed by general formula (I) CH2=C(R1)COO(CH2)k(ClF2l)(CH 2)kOOCC(R1)=CH2...(I) (wherein, k is 1 or 2; l is an integer of 1-20; and R1 is H, CH3, F or Cl) and a monomer (B) having a (meth)acryloyl group other than the monomer (A). A cured material of the composition has a refractive index of <=1.45 and a Shore hardness of >=D80.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fluorine-based active energy ray-curable composition having a low refractive index.

[0002]

2. Description of the Related Art With the development of 1T technology in recent years, multimedia products such as mobile phones, notebook computers, video cameras, and projectors, and various OA devices such as various terminal devices, printers, and facsimile machines have been widely used. There is a remarkable development of optical fibers for functional use and various connecting parts for constructing a system including the same. Most of these products / parts are provided with a light source or an optical system using visible light in any part thereof, or a treatment is taken so that the original performance is not impaired by visible light. Accordingly, there are many cases where optical properties are required as materials in such products and parts.

Among them, low refractive index is also indispensable in designing optical fiber clad materials, various lens materials and the like. Generally, the refractive index is defined by the following Lorentz-Lorenz equation. (ND2-1) / (nD2 + 2) = R / V Here, nD is a refractive index, R is molecular refraction, and V is molecular volume. Here, in order to realize a low refractive index, it is preferable that the molecular refraction R is small and the molecular volume V is large. From this point, a fluorine atom can realize the lowest refractive index. fact,
W. Groh and A. Z1 mmermann, Macromolecules, 24, 6660
(1991) introduces a low-refractive-index polymer obtained by calculation, and a fluorine-based polymer exhibits the lowest refractive index. Against this background, various low-refractive-index optical materials using a fluorine-based resin have been proposed. In some cases, its use is limited due to low durability of mechanical characteristics, mechanical characteristics and optical characteristics. In particular, as various components become smaller, thinner, and more sophisticated, materials having a low refractive index and high strength are strongly demanded in terms of dimensional stability and durability as optical materials.
Conventional fluorine-based low refractive index compositions are disclosed in
No. 801, Japanese Patent No. 2138024, Japanese Patent No.
No. 099228, JP-A-4-298514, and the like have been proposed, but no sufficient composition has been obtained in terms of a high-strength material.

[0004]

SUMMARY OF THE INVENTION Under the circumstances described above, an object of the present invention is to provide both low refractive index, high strength and high durability, and excellent transparency that can be used for various optical applications. An object of the present invention is to provide a fluorine-based active energy ray-curable composition.

[0005]

The present inventors have made intensive studies to solve the above-mentioned problems, and found that the following general formula (1): CH2 = C (R1) COO (CH2) k (ClF2l) (CH2) kOOCC (R1) = CH2 (1) (where k is 1 or 2, l is an integer of 1 to 20, and R1 represents H, CH3, F or Cl.) And a monomer (B) having a (meth) acryloyl group other than the monomer (A) represented by the formula: wherein the cured product of the composition has a refractive index of 1.45 or less. Existence and Shore hardness is D8
An active energy ray-curable composition characterized by being 0 or more was found, and the present invention was completed.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a (meth) acryloyl group is a general term for a methacryloyl group and an acryloyl group. First, the monomer (A) is the most important compound for realizing low refractive index and high strength, which are the objects of the present invention. That is, it has a fluorine-containing segment essential for realizing low refractive index and a bifunctional or higher functional reactive group essential for realizing high strength in one molecule. However, the monomer (A) itself is a known compound, and is used in various active energy ray-curable compositions for optical use. In the present invention, in order to solve the above-mentioned problem, a monomer (A) and a monomer (B) having a (meth) acryloyl group other than the monomer (A) are used in combination. The novelty resides in finding a composition in which the cured product of the composition has a refractive index of 1.45 or less and a Shore hardness of D80 or more.

As the monomer (A) in the present invention, known and publicly-known compounds can be used without limitation as long as they satisfy the general formula (1). Specific compounds of the monomer (A) include the following compounds.

[0008]

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It is needless to say that the present invention is not limited at all by the above specific examples. In the general formula (1) representing the monomer (A), the CF2 chain length (1 in the general formula (1)), which is a fluorine-containing segment, is important from the viewpoint of achieving both low refractive index and optical characteristics. That is, when l is 3 or less, the fluorine content in the composition becomes low and it becomes difficult to achieve the intended low refractive index. Conversely, when l is 13 or more, the crystallinity of the ClF2l chain increases. As a result, the transparency tends to be impaired due to an increase in the degree of crystallinity in the composition, or the objective cannot be achieved due to lack of compatibility with the monomer (B) described later. From such a point, when l ≦ 3 or less or l ≧ 13, it can be used in limited applications depending on the required low refractive index or degree of transparency. The optimal value of the CF2 chain length is
The value of l in the general formula (1) is preferably from 4 to 12, and more preferably from 4 to 8, although it varies depending on the intended use, desired required characteristics, and the like. Further, the ClF2l chain may be linear or branched. Further, only one type of the monomer (A) may be used, or two or more types may be used simultaneously.

In the present invention, if the monomer (A) is missing, the desired low refractive index, mechanical strength, and various durability cannot be satisfied, and a sufficient material cannot be obtained as a practical material.

The amount of the monomer (A) to be introduced in the present invention is not particularly limited, but varies depending on the intended refractive index, mechanical strength, various durability and the like, and is preferably 5 to 99% by weight in the composition. It is more preferably from 10 to 90% by weight, particularly preferably from 20 to 80% by weight.

Next, the monomer (B) having a (meth) acryloyl group other than the monomer (A) may be a compound having a (meth) acryloyl group in a molecule of 1 to 95% by weight.
Can be used. The monomer (B) has physical properties such as a desired refractive index, transparency, scattering property, mechanical strength, various durability, adhesiveness to a substrate, curing shrinkage, and a phase with the monomer (A). It can be appropriately selected in consideration of the solubility.

According to the findings of the present inventors, the introduction of the monomer (B-1) represented by the following general formula (2) as the monomer (B) mainly from the viewpoint of controlling the refractive index. Is also possible. XCF2 (CmF2m)-(CH2) n-OOCC (R1) = CH2 (2) (where X is F or H, m is an integer of 0 to 20, n is 0
Or an integer of 1 to 6, wherein R1 is as defined above. )

As the monomer (B-1), known and used compounds can be used without limitation as long as they are compounds represented by the general formula (2). Specific compounds of the monomer (B-1) include the following compounds.

B-1-1: CH2 = CHCOOCH2CH2C8F17 B-1-2: CH2 = C (CH3) COOCH2CH2C8F17 B-1-3: CH2 = CHCOOCH2CH2C12F25 B-1-4: CH2 = C (CH3) COOCH2CH2C12F25 B-1 -5: CH2 = CHCOOCH2CH2C10F21 B-1- 6: CH2 = C (CH3) COOCH2CH2C10F21 B-1- 7: CH2 = CHCOOCH2CH2C6F13 B-1- 8: CH2 = C (CH3) COOCH2CH2C6F13 B-1- 9: CH2 = CHCOOCH2CH2C4F9 B-1-10: CH2 = CFCOOCH2CH2C6F13 B-1-2: CH2 = C (CH3) COOCH2CH2C20F41 B-1-12: CH2 = C (CH3) COOCH2CH2C4F9 B-1-13: CH2 = C (CF3) COO (CH2 ) 6 C10F21 B-1-14: CH2 = C (CH3) COOCH2CF3 B-1-15: CH2 = CHCOOCH2CF3 B-1-16: CH2 = CHCOOCH2C8F17 B-1-17: CH2 = C (CH3) COOCH2C8F17 B-1 -18: CH2 = C (CH3) COOCH2C20F41 B-1-19: CH2 = CHCOOCH2C20F41 B-1-20: CH2 = C (CH3) COOCH2CF (CF3) 2 B-1-21: CH2 = C (CH3) COOCH2CFHCF3 B -1-22: CH2 = CFCOOCH2C2F5 B-1-23: CH2 = CHCOOCH2 (CH2) 6CF (CF3) 2 B-1-24: CH2 = C (CH3) COOCHCF2CFHCF3 B-1-25: CH2 = C (CH3) COOCH (C2H5) C10F21 B-1-26: CH2 = CHCOOCH2 (CF2) 2H B-1-27: CH2 = C (CH3) COOCH2 (CF2) 2H B-1-28: CH2 = CHCOOCH2 (CF2) 4H B-1-29: CH2 = CHCOOCH2CF3 B-1-30: CH2 = C ( CH3) COO (CF2) 4H B-1-31: CH2 = CHCOOCH2 (CF2) 6H B-1-32: CH2 = C (CH3) COOCH2 (CF2) 6H B-1-33: CH2 = CHCOOCH2 (CF2) 8H B-1-34: CH2 = C (CH3) COOCH2 (CF2) 8H B-1-35: CH2 = CHCOOCH2 (CF2) 10H B-1-36: CH2 = CHCOOCH2 (CF2) 12H B-1-37: CH2 = CHCOOCH2 (CF2) 14H B-1-38: CH2 = CHCOOCH2 (CF2) 18H B-1-39: CH2 = CHCOOC (CH3) 2 (CF2) 4H B-1-40: CH2 = CHCOOCH2CH2 (CF2) 7H B -1-41: CH2 = C (CH3) COOCH2CH2 (CF2) 7H B-1-42: CH2 = C (CH3) COOC (CH3) 2 (CF2) 6H B-1-43: CH2 = CHCOOCH (CF3) C8F17 B-1-44: CH2 = CHCOOCH2C2F5 B-1-43: CH2 = CHCOO (CH2) 2 (CF2) 8CF (CF3) 2 The present invention is not limited by the above specific examples. Of course, it is not.

According to the findings of the present inventors, general formula (2)
When m is 9 or more, the content of fluorine is high, which is advantageous for lowering the refractive index. However, on the other hand, the crystallinity is high and the transparency of the cured product is reduced. Further, those having m of 0 have good compatibility with other compositions and high transparency of the cured product, but are disadvantageous in realizing a low refractive index due to a low fluorine content. From such a viewpoint, the target refractive index, transparency,
The optimum compound differs depending on the compatibility with other compositions, but in order to achieve both low refractive index and transparency, it is preferable that m in the general formula (2) is 1 to 8, and 3 to 7 is more preferred.

Furthermore, a polyfunctional monomer having two or more (meth) acryloyl groups in one molecule (B-
When 2) is used in combination, X in the general formula (2) is preferred from the viewpoint of improving the compatibility, the transparency of the cured product, and the mechanical properties.
Is preferably H. Generally, the terminal structure —CF of the monomer (A) in which X in the general formula (2) is H
2H is known to have a higher surface free energy than the terminal structure -CF3 of the monomer (A) in which X in the general formula (2) is F. Therefore, -CF2H is -CF
It can be estimated that the interfacial tension in the composition is more likely to be lower than that of No. 3, or that the SP value changes to improve the compatibility. As described above, if the compatibility between the fluorine-containing compound and the non-fluorine compound is improved, the permissible range of the material design with respect to the desired properties is expanded, and it is possible to find a new composition that has not been found conventionally. Become. From such a point, the compound in which X in the general formula (2) is H plays a very important role depending on the system.

The monomer (B-1) may be used alone or in combination of two or more compounds. In addition, as is clear from the structure of the general formula, CmF2m
The portion may be linear or branched. When the monomer (B-1) is introduced, the amount of the monomer (B-1) to be introduced is not particularly limited, but the target refractive index, the CF2 chain length in the monomer (A) and the monomer (B-1) are required. 5 to 80% by weight, preferably 10 to 70% by weight, more preferably 20 to 70% by weight in the composition.
It is.

The present inventors propose a Shore hardness, which will be described later, mainly as one of indexes for improving mechanical properties and various durability. According to the knowledge of the present inventors, the shore hardness of the cured product of the composition is preferably D80 or more from the viewpoint of improving the mechanical properties and various durability of various optical members. Shore hardness of 80 or more, and thus mechanical properties of various optical members,
From the viewpoint of various durability improvements, it is effective to introduce a polyfunctional monomer (B-2) having two or more (meth) acryloyl groups in one molecule. Polyfunctional monomer (B-2)
Any known compound can be used without limitation as long as it has two or more (meth) acryloyl groups in one molecule. Specific compounds of the monomer (B-2) include the following compounds.

B-2-1: Ethylene glycol di (meth) acrylate B-2-2: Diethylene glycol di (meth) acrylate B-2-3: Triethylene glycol di (meth) acrylate B-2-4: Polyethylene glycol Di (meth) acrylate (number average molecular weight: 150 to 1000) B-2-5: Propylene glycol di (meth) acrylate B-2-6: Dipropylene glycol di (meth) acrylate B-2-7: Tripropylene glycol Di (meth) acrylate B-2-8: polypropylene glycol di (meth) acrylate (number average molecular weight: 150 to 1000) B-2-9: neopentyl glycol di (meth) acrylate B-2-10: 1,3 -Butanediol di (meth) acrylate B-2-2: 1,4-butanediol di (meth) acrylate B-2-12: 1,6- Hexanediol di (meth) acrylate B-2-13: hydroxypivalic acid ester neopentyl glycol di (meth) acrylate

[0021]

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B-2-16: Bisphenol A di (meth)
Acrylate B-2-17: Trimethylolpropane tri (meth) acrylate B-2-18: Pentaerythritol tri (meth) acrylate B-2-19: Dipentaerythritol hexa (meth) acrylate B-2- 20: Pentaerythritol tetra (meth) acrylate B-2-21: Trimethylolpropane di (meth) acrylate B-2-22: Dipentaerythritol monohydroxypenta (meth) acrylate B-2-23: Di Cyclopentenyl (meth) acrylate

Here, (meth) acrylate is a general term for acrylate and methacrylate. Specific examples other than the above include Neomer NA-305 and Neomer BA-
601, Neomer TA-505, Neomer TA-4
01, Neomer PHA-405X, Neomer TA7
05X, Neomer EA400X, Neomer EE40
1X, Neomer EP405X, Neomer HB601
X, Neomer HB605X (all manufactured by Sanyo Chemical Industries, Ltd.), KAYARAD HY-220, KAYARAD HX-6
20, KAYARAD D-310, KAYARAD D-320, KA
YARAD D-330, KAYARAD DPHA, KAYARAD D
PCA-20, KAYARAD DPCA-30, KAYARAD D
PCA-60 and KAYARAD DPCA-120 (all manufactured by Nippon Kayaku Co., Ltd.) are also included. It should be noted that the present invention is of course not limited by the above specific examples.

According to the findings of the present inventors, the low refractive index of the composition is maintained, and the shore hardness of the cured product is at least D80, and the intended mechanical properties and various durability are effectively improved. For this purpose, the polyfunctional monomer (B-2) preferably has three or more functional groups. In addition, a polyfunctional monomer (B-
2) has two or more highly polar (meth) acryloyl groups in the molecule, so that the monomer (A) having a fluorine-containing segment and the monomer (B-
In many cases, compatibility with 1) is lacking. From such a viewpoint, the polyfunctional monomer (B-2) is at least one selected from the group consisting of trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate. Preferably, there is.

As the polyfunctional monomer (B-2), only one kind may be used, or two or more kinds may be used at the same time.
When the polyfunctional monomer (B-2) is introduced, the amount to be introduced is not particularly limited, but varies depending on compatibility with other components, desired mechanical properties, various durability, degree of transparency, and the like. But,
It is 0.5 to 50% by weight, preferably 2 to 30% by weight, particularly preferably 4 to 20% by weight in the composition.

According to the findings of the present inventors, the monomer (B-1) and the monomer (B-2) can be appropriately introduced according to the purpose, but have a low refractive index. It is more preferable to use them at the same time from the viewpoint of compatibility between mechanical properties and various durability. The preferable introduction amount when used simultaneously is different depending on the introduction amount of the monomer (A) or the purpose, but in a weight ratio, monomer (A) / monomer (B-1) / monomer (B -2) = 5 to 99/5 to 70 / 0.5 to 50, preferably monomer (A) / monomer (B-1) / monomer (B-
2) = 20-70 / 20-70 / 4-20.

In the present invention, in addition to the monomer (B-1) and the monomer (B-2) described above as the monomer (B), a known and used unit having a (meth) acryloyl group may be used. It is possible to introduce a monomer according to the purpose. Specific examples of such compounds include methyl (meth) acrylate,
n-propyl (meth) acrylate, 1-propyl (meth) acrylate, n-butyl (meth) acrylate, 1
-Butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate,
Octyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, aliphatic ester (meth) acrylate such as isostearyl (meth) acrylate, glycerol ( (Meth) acrylate, 2-hydroxyl (meth) acrylate, 3-chloro-2-hydroxyl (meth) acrylate, glycidyl (meth) acrylate, allyl (meth) acrylate, butoxyethyl (meth) acrylate, butoxyethylene glycol (meth) acrylate , N, N, -diethylaminoethyl (meth) acrylate, N, N, -dimethylaminoethyl (meth) acrylate, γ- (meth) acryloxypropyltrimethoxysilane, 2-methoxyethyl (meth) acyl Relate, methoxydiethylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolypropylene glycol (meth) acrylate, Aronix M-5700
(Manufactured by Toagosei Kogyo Co., Ltd.), phenoxyethyl (meth) acrylate, phenoxydipropylene glycol (meth) acrylate, phenoxypolypropylene glycol (meth) acrylate, AR-200, MR-2
60, AR-200, AR-204, AR-208, M
R-200, MR-204, MR-208 (all manufactured by Daihachi Chemical Co., Ltd.), Viscoat 2000, Viscoat 2
308 (all manufactured by Osaka Organic Chemical Industry Co., Ltd.), polybutadiene (meth) acrylate, polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, polyethylene glycol-polypropylene glycol (meth) acrylate, polyethylene glycol-polybutylene glycol ( Meth) acrylate, polystyrylethyl (meth) acrylate,
Light ester HOA-MS, light ester HO
MS (Kyoeisha Chemical Co., Ltd.) Benzyl (meta)
Acrylate, cyclohexyl (meth) acrylate,
Dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, isobornyl (meth)
Acrylate, methoxylated cyclodecatriene (meth)
Acrylate, phenyl (meth) acrylate, FANCRY
L FA-512A, FANCRYL FA-512M (above,
Hitachi Chemical Co., Ltd.). It should be noted that the present invention is of course not limited by the above specific examples.

Among these compounds, an ester substituent has a cyclic structure as a compound having an effect of improving the compatibility with other components in the composition and the transparency of the cured product by introducing a small amount thereof. B-3-1: benzyl (meth) acrylate B-3-2: cyclohexyl (meth) acrylate B-3-3: dicyclopentanyl (meth) acrylate B-3-4: dicyclopentenyl (meth) Acrylate B-3-5: Isobornyl (meth) acrylate B-3-6: Methoxylated cyclodecalin (meth) acrylate B-3-7: Phenyl (meth) acrylate B-3-8: FANCRYL FA-512A (Hitachi Chemical) B-3-9: FANCRYL FA-512M (manufactured by Hitachi Chemical Co., Ltd.) B-3-10: Adamantyl (meth) acrylate B-3-2: Dimethyladamantyl (meth) acrylate is preferred. Further, among these, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate and isobornyl (meth) acrylate are particularly preferred from the viewpoint of temperature stability relating to the transparency of the cured product. From the viewpoint of improving the adhesion to various substrates, B-3-12: γ- (meth) acryloxypropyltrimethoxysilane is preferred.

As such a monomer (B), only one kind may be used, or two or more kinds may be used in any combination.

As the energy source for curing the active energy ray-curable composition according to the present invention, one or more types of active energy rays such as light, electron beam and radiation can be used. In some cases, it is also possible to use heat together with these active energy rays as an energy source. When light such as ultraviolet light is used as the active energy ray, a known and used photoinitiator is preferably used as a catalyst. Specific examples of the photoinitiator include the following compounds. C-1: benzophenone C-2: acetophenone C-3: benzoin C-4: benzoin ethyl ether C-5: benzoin isobutyl ether C-6: benzyl methyl ketal C-7: azobisisobutyronitrile C-8: 1-hydroxycyclohexyl phenyl ketone C-9: 2-hydroxy-2-methyl-1-phenyl-1-one C-10: 1- (4'-isopropylphenyl) -2-
Hydroxy-2-methylpropan-1-one C-2: 1- (4'-dodecylphenyl) -2-hydroxy-2-methylpropan-1-one C-12: 3,3'4,4'-tetra (t-butylperoxycarbonyl) benzophenone C-13: 4,4 ''-diethylisophthalophen C-14: 2,2-dimethoxy-1,2-diphenylethan-1-one C-15: benzoin isopropyl ether C-16: Thioxanthone C-17: 2-Chlorothioxanthone C-18: 2-Methylthioxanthone C-19: 2-Isopropylthioxanthone C-20: 2-Methyl-1 [4- (methylthio) phenyl ] -2-
Morpholinopropan-1-one C-21: 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 C-22: bis (2,6-dimethoxybenzoyl) -2,4 , 4-Trimethyl-pentylphosphine oxide C-23: bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide C-24: 2,4,6-trimethylbenzoyldiphenylphosphine oxide However, it is needless to say that the above is not limited at all by the above specific examples.

The photoinitiator may be used alone or in combination of two or more. Among these, C-9 is particularly preferred from the viewpoint of compatibility with the monomer in the composition.

Further, if necessary, a photosensitizer such as an amine compound or a phosphorus compound can be added to accelerate the polymerization. The introduced amount of the photoinitiator in the active energy ray-curable composition according to the present invention is 0.01 to 15% by weight, more preferably 0.1 to 10% by weight, and particularly preferably 0.3 to 7% by weight. %. When polymerizing and curing with an electron beam or radiation, addition of a polymerization initiator or the like is not particularly required.

The active energy ray-curable composition according to the present invention may contain, if necessary, various known and used additives. As additives, solvents for viscosity adjustment, light stabilizers, weather stabilizers, heat stabilizers,
Examples include an antifoaming agent, a flame retardant, a leveling agent, a release agent, a coloring agent, a surface modifier, and a coupling agent for improving adhesion to a substrate such as glass. Examples of the coupling agent include silane-based, titanium-based, and zirco-aluminate-based ones, among which dimethyldimethoxysilane, dimethyldiethoxysilane, methyltrimethoxysilane, dimethylvinylmethoxysilane, and phenyltrimethoxysilane. , Γ-chloropropyltrimethoxysilane, γ-chloropropylmethyldimethoxysilane, γ
-Aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-methacryloxypropylmethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-acryloxypropylmethyl Silanes such as trimethoxysilane, γ-acryloxypropylmethyldimethoxysilane and γ-mercaptopropyltrimethoxysilane are particularly preferred. It should be noted that the present invention is of course not limited by the above specific examples.

Further, depending on the processing method such as the coating method and the molding method of the composition, a publicly known oligomer or polymer can be appropriately introduced mainly for the purpose of adjusting the viscosity of the composition. .

With the recent diversification of optical materials, such as miniaturization, thinning, and functionalization, the durability of mechanical properties, mechanical properties, optical properties, surface properties, thermal properties, and the like according to the purpose of the optical materials has been improved. Strongly required. From such a viewpoint, the present inventors need to use a cured product having a Shore hardness of D80 or more in the above-described composition in order to realize mechanical properties and mechanical properties, optical properties, and durability such as surface properties. I found something. Shore hardness of the cured product of the composition,
D80 or more is essential, preferably D84
That is all.

The refractive index of the low refractive index resin used for various optical applications as described below is selected according to the purpose, but in many cases it is 1.45 or less, and 1.42 or less is more preferable. preferable.

As an energy source for curing the active energy ray-curable composition according to the present invention, known and publicly available devices and energy sources can be used, for example, a germicidal lamp, a fluorescent lamp for ultraviolet rays, a carbon arc, xenon. Lamps, high-pressure mercury lamps for copying, medium- or high-pressure mercury lamps, ultra-high-pressure mercury lamps, electrodeless lamps, metal halide lamps, ultraviolet light using natural light as the light source, or electron beams from a scanning or curtain electron beam accelerator can be used. In the case of UV curing with a thickness of 5 μm or less, irradiation is preferably performed in an atmosphere of an inert gas such as nitrogen gas from the viewpoint of polymerization efficiency. It is also possible to use heat as an energy source if necessary, or to perform heat treatment after curing with an active energy ray.

The method for processing the active energy ray-curable composition according to the present invention is not particularly limited, and includes a gravure coater, roll coater, comma coater, knife coater, curtain coater, shower coater, spin coater, dipping, screen printing, and the like. A coating method using a spray, an applicator, a bar coater, or the like, or a molding method using various molds may be used. The composition according to the present invention can be widely used as an optical fiber clad material, an optical lens, a waveguide, a liquid crystal sealing material, various optical sealing materials, various protective films, optical adhesives, and various optical components. is there.

The present invention comprises a monomer (A) represented by the general formula (1) and a monomer (B) having a (meth) acryloyl group other than the monomer (A), Has a refractive index of 1.45 or less and a Shore hardness of D80.
By using the active energy ray-curable composition described above, it is possible to obtain a cured product which is excellent in low refractive index and transparency, and has excellent mechanical properties and various durability and can be widely applied as an optical application. .

[0040]

Next, specific examples of the present invention will be described. However, it is needless to say that the present invention is not limited by these descriptions.

(Formulation Example 1) A-5: 98.5 parts by weight, B-3-1
2: 1 parts by weight and C-9: 0.5 parts by weight were weighed into a light-shielded Erlenmeyer flask, and stirred at room temperature using a stirrer chip to obtain a colorless, transparent and uniform liquid. The resulting solution was subjected to defoaming under reduced pressure using an aspirator and then filtered through a 1 μm filter to obtain an active energy ray-curable composition sample.

(Formulation Examples 2 to 11) Except for the monomers and photoinitiator used, an active energy ray-curable composition was prepared in the same manner as in Formulation Example 1. Table 1 summarizes these results.

[0043]

[Table 1]

In the table, (B-3-12), (B-3-4), (B-1-1), (B
(-1-28), (B-2-9), (B-2-17), (B-2-20) and (B-2-19) all used acrylate.

Next, the active energy ray-curable composition obtained in Formulation Example 1 was used for measuring transmittance and refractive index in a glass casting frame from which a cured test specimen of 10 mm × 40 mm × 1 mm could be taken. And covered with a glass plate. After that, 2000mJ / cm with a high-pressure mercury lamp with an output of 120W / cm
The test piece was obtained by completely curing with irradiation energy of 2. The transmittance at 450 nm was 96%, and the refractive index measured at 25 ° C. with an Abbe refractometer was 1.430.

For measuring Shore hardness, 15 mm × 1
It was also poured into a glass casting frame from which a 5 mm x 5 mm cured test piece could be taken, covered with a glass plate, and cured under the same conditions as above. The Shore hardness measured using the obtained test piece was D88.

(Formulation Examples 2-2) A cured test piece was prepared from the formulation in the same manner as in Example 1, and the transmittance, refractive index, and Shore hardness were measured. However, in the case of Formulation Example 9, a uniform solution could not be obtained, so that physical properties after curing could not be obtained. Table 2 summarizes these results.

[0048]

[Table 2]

(Examples 1 to 8 and Comparative Examples 1 and 2) (Preparation of Optical Lens) 1 mm in thickness subjected to a primer treatment with γ-methacryloxypropyltrimethoxysilane
Urethane acrylate obtained by reacting high refractive index resin (2-butyl-2-ethylpropanediol with 4,4'-diphenylmethane diisocyanate and then 2-hydroxyethyl acrylate on a quartz glass plate: cured A high-pressure mercury lamp with an output of 120 W / cm is applied from below through a quartz glass plate after pressing a metal mold having a random irregular pattern of a certain size from above (FIG. 1-A). Irradiation energy amount at
It was cured at 000 mJ / cm 2 (FIG. 1-B). Next, after removing the mold, the compounded liquids of Examples and Comparative Examples were placed on a quartz glass plate having a thickness of 40 μm, (FIG. 1-C) the demolded substrate was covered and pressed, and the output of 120 W / cm was obtained. An optical lens was obtained by curing with a high-pressure mercury lamp at an irradiation energy of 2000 mJ / cm2 (Fig. 1-
D). In addition, as shown in FIG. 1-D, the low refractive index resin according to the present invention has such a structure as to entirely cover the high refractive index resin.
In the figure, (1) is a mold, (2) is a high refractive index resin, (3)
Indicates a quartz glass plate, and (4) indicates a mixture of Examples and Comparative Examples, respectively.

(Evaluation of wet heat resistance) The thus obtained optical lens was left at 70 ° C. and 98% RH for 500 hours to maintain the thickness between the quartz glass formed of the low refractive index resin and the high refractive index resin. Rate was evaluated. The thickness is measured with an optical microscope.
The values at both ends in the cross-sectional view shown in FIG. 1 were measured, the average value was adopted, and the maintenance rate was calculated by the following equation. (Thickness maintenance ratio) = (Thickness after wet heat resistance test) / (Initial thickness)

(Evaluation of Chemical Resistance) An optical lens obtained by the same manufacturing method was placed in isopropyl alcohol at room temperature for 2 hours.
4 hours, then left in acetone at room temperature for 24 hours,
The maintenance ratio of the thickness between the quartz glass formed of the low refractive index resin and the high refractive index resin was evaluated. In addition, the thickness maintenance rate was calculated by the following equation. (Thickness maintenance rate) = (Thickness after chemical resistance test) / (Initial thickness)

Table 3 also shows the results of the evaluations of the wet heat resistance and the chemical resistance of the optical lenses prepared using the respective compounding solutions.

[0053]

[Table 3]

It is apparent that the optical lens using the active energy ray-curable composition according to the present invention has excellent wet heat resistance and chemical resistance and has stable dimensional stability over time.

[0055]

Industrial Applicability The present invention can provide a curable composition which is excellent in low refractive index and transparency, and excellent in mechanical properties and various durability and can be widely applied as an optical application.

[0056]

[Brief description of the drawings]

FIG. 1 is a schematic view showing step by step the manufacturing process of an optical lens obtained using the present invention and a comparative curable composition.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H047 QA05 2H050 AB43Y AB44Y AB50Y 4J100 AL08Q AL62R AL63R AL66P AL66R BA02R BA03R BA08R BA15R BB12P BB13P BB13Q BB18Q BC28R BC45R BC58R CA03 CA04 CA05 DA48 DA63 DA

Claims (5)

[Claims] 1. A composition comprising a monomer (A) represented by the following general formula (1) and a monomer (B) having a (meth) acryloyl group other than the monomer (A). An active energy ray-curable composition, wherein the cured product of the composition has a refractive index of 1.45 or less and a Shore hardness of D80 or more. CH2 = C (R1) COO (CH2) k (ClF2l) (CH2) kOOCC (R1) = CH2 (1) (where k is 1 or 2, and l is 1 to 2) An integer of 20, and R1 represents H, CH3, F or Cl.) 2. The monomer (B) is a monomer (B-1) represented by the following general formula (2) and / or a polyfunctional compound having two or more (meth) acryloyl groups in one molecule. Monomer (B-
The active energy ray-curable composition according to claim 1, which is 2). XCF2 (CmF2m)-(CH2) n-OOCC (R1) = CH2 (2) (where X is F or H, m is an integer of 0 to 20, n is 0
Or an integer of 1 to 6, wherein R1 is as defined above. ) 3. In the general formula (2), X is H and m is 1 to 8.
The active energy ray-curable composition according to claim 2, which is an integer of 4. The active energy ray-curable composition according to claim 2, wherein the polyfunctional monomer (B-2) has three or more functional groups. 5. The polyfunctional monomer (B-2) is at least one selected from the group consisting of trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, and dipentaerythritol hexaacrylate. The active energy ray-curable composition according to any one of claims 2 to 4.