JP5427012B2 - Resin composition for optical materials - Google Patents

Description

  The present invention relates to a resin composition for an optical material, and more particularly to a resin composition for an optical material suitable for a high refractive index coating material having excellent low curing shrinkage, adhesion, and transparency, and a cured product thereof.

High refractive index plastics are widely used for optical materials because of their ease of molding and light weight.
Examples of means for achieving a high refractive index include a method of introducing a bromine atom into the molecular structure of the resin composition and a method of blending a bifunctional (meth) acrylate having a fluorene skeleton (for example, Patent Document 1). ).
However, a resin into which a bromine atom is introduced has a drawback that it has a high refractive index but tends to be brittle, has a large specific gravity, and deteriorates light resistance.
Further, when the refractive index is increased by blending a bifunctional (meth) acrylate having a fluorene skeleton, the adhesion to the substrate is lowered. Furthermore, when thick film coating is applied, curing shrinkage is large and the coated sheet is likely to curl, which often impedes molding and processing.

JP 2003-322706 A

Under such circumstances, a resin composition excellent in adhesion and / or low curl is desired as a coating material for optical applications while realizing a high refractive index.
This invention is made | formed in view of such a subject, and it aims at providing the resin composition for optical materials excellent in adhesiveness and / or low curl, implement | achieving high refractive index.

The resin composition for an optical material of the present invention is
It contains a bifunctional (meth) acrylate compound (A) having a fluorene skeleton represented by the formula (1) and at least one monofunctional (meth) acrylate compound (B).
(In formula, R < ¹ > and R < ² > are the same or different, a hydrogen atom or a methyl group, and a and b represent the integer of 1-4, respectively.)

  In such a resin composition for optical materials, the monofunctional (meth) acrylate compound (B) contains benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, m-phenoxybenzyl (meth) acrylate and o-phenylphenoxyethyl. It is preferably at least one selected from the group consisting of (meth) acrylates.

It is preferable to further contain a (meth) acrylate compound (C) other than the monofunctional (meth) acrylate compound (B) component.
It is preferable to further contain a photopolymerization initiator (D).
The refractive index is preferably 1.60 or more at 25 ° C.
The cured product of the present invention is obtained by curing the above-described resin composition for optical materials.

  ADVANTAGE OF THE INVENTION According to this invention, the resin composition for optical materials excellent in adhesiveness and / or low curl can be provided, implement | achieving high refractive index.

  The resin composition for an optical material of the present invention (hereinafter sometimes simply referred to as “resin composition”) is a bifunctional (meth) acrylate compound (A) having a fluorene skeleton represented by the above formula (1). And a monofunctional (meth) acrylate compound (B).

Specific examples of the compound of the formula (1) include the following compounds (a) to (h).

Of these, the compound (a) is preferable. This is because the refractive index of the cured product using this can be further improved and the curing rate by ultraviolet irradiation can be increased.
These compounds may be used alone or in combination of two or more.
The compound of the formula (1) can be obtained using a method known in the art, for example, a method described in JP-A-2008-94987 and JP-A-2001-206863, or a method analogous thereto. it can.

Further, the monofunctional (meth) acrylate compound (B) is not particularly limited. For example, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, m-phenoxybenzyl (meth) acrylate, o- Examples include phenylphenoxyethyl (meth) acrylate. Further, (meth) acrylic acid benzyl esters described in JP-A No. 2001-139518 may be used.
The monofunctional (meth) acrylate compound (B) can be produced by a method known in the art, for example, a method described in JP-A No. 2001-139518 or a method analogous thereto.

  In the resin composition of the present invention, the compound (A) represented by the formula (1) and the monofunctional (meth) acrylate compound (B) are, for example, a weight ratio of about 0.1: 1 to 10: 1. The weight ratio of about 0.4: 1 to 8: 1 is preferable.

The resin composition for optical materials of the present invention may contain a compound other than the compound (A) represented by the formula (1) and the monofunctional (meth) acrylate compound (B).
Of these, it is suitable to further use a (meth) acrylate compound (C) other than the monofunctional (meth) acrylate compound (B).

Examples of such a compound (C) include monofunctional or two or more polyfunctional (meth) acrylates.
As monofunctional (meth) acrylate, for example, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n -Octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, glycidyl (meth) acrylate, morpholine (meta) ) Acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, diethylene glycol mono (meth) Chryrate, triethylene glycol mono (meth) acrylate, dipropylene glycol mono (meth) acrylate, 2-methoxyethyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxypolyethylene glycol (meta ) Acrylate, 2-butoxyethyl (meth) acrylate, butoxytriethylene glycol (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- (2-ethoxyethoxy) ethyl (meth) acrylate, ethoxy polyethylene glycol (meth) Acrylate, 4-nonylphenoxyethylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, caprolactone modified Trahydrofurfuryl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, cyclohexylmethyl (meth) acrylate, cyclohexylethyl ( (Meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentanyloxyethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, o-phenylphenoxyethyl (meth) ) Acrylate and the like.

  Examples of the bifunctional (meth) acrylate include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and propylene glycol di (meth) acrylate. , Dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, tetrabutylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethylene oxide of bisphenol A Di (meth) acrylate of ido adduct, di (meth) acrylate of propylene oxide adduct of bisphenol A, bisphenoxyethanol full orange (meth) acrylate, dicyclopentanyl di (meth) acrylate, glycerol di (meth) acrylate, Neopentyl glycol hydroxypivalate ester di (meth) acrylate, caprolactone modified hydroxypivalate neopentyl glycol di (meth) acrylate, tetrabromobisphenol A di (meth) acrylate, hydropivalaldehyde modified trimethylolpropane di (meth) acrylate, Examples include 1,4-cyclohexanedimethanol di (meth) acrylate.

  Examples of the polyfunctional (meth) acrylate include trimethylolpropane tri (meth) acrylate, tri (meth) acrylate of trimethylolpropane ethylene oxide adduct, tri (meth) acrylate of propylene oxide adduct of trimethylolpropane, Pentaerythritol tri (meth) acrylate, glycerol tri (meth) acrylate, tri (meth) acrylate of alkyl-modified dipentaerythritol, ditrimethylolpropane tetra (meth) acrylate, tetra (meth) of ethylene oxide adduct of ditrimethylolpropane Examples include acrylate and tetra (meth) acrylate of propylene oxide adduct of ditrimethylolpropane.

Among them, as monofunctional (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, caprolactone-modified tetrahydrofurfuryl (meth) acrylate, o-phenylphenoxyethyl (meth) Preferred are acrylates and the like, and bifunctional (meth) acrylates include 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and ethylene of bisphenol A. Di (meth) acrylate of an oxide adduct, neopentyl glycol hydroxypivalate ester di (meth) acrylate, bisphenoxyethanol full orange (meth) acrylate, etc. are preferable, As the functional (meth) acrylate, trimethylolpropane tri (meth) acrylate are preferable.
You may use these individually or in combination of 2 or more types.

  When such a (meth) acrylate compound (C) is used, the component (A) is 20 to 80 parts by weight with respect to (A) + (B) + (C) component = 100 parts by weight, The component ()) is suitably 10 to 70 parts by weight, and the component (C) is suitably 0 to 50 parts by weight. However, in this case, the total amount of the components (A) + (B) is suitably in the range of 40 to 100 parts by weight, preferably in the range of 50 to 100 parts by weight, More preferably, it is within the range of parts by weight. In other words, the compound (C) is preferably contained so as not to become the main component (the component with the largest content weight) of the resin component in the resin composition of the present invention, and the resin component in the resin composition of the present invention On the other hand, it is preferably contained in an amount of about 45% by weight or less.

The resin composition for optical materials of the present invention may further contain a photopolymerization initiator (D).
The photopolymerization initiator (D) is a polymerizable initiator that generates radicals with active energy rays such as ultraviolet rays. Examples of such photopolymerization initiator (D) include hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 2, Examples include 4,6-trimethylbenzoylphosphine oxide.
You may use these individually or in combination of 2 or more types.
When using such a photoinitiator (D), about 0.1 to 10 weight% is suitable with respect to the total weight of the resin composition for optical materials of this invention, 0.5 to 6 About 2% by weight is preferable, and 2 to 6% by weight is more preferable.

In addition to the above components, the resin composition for optical materials of the present invention may contain an organic solvent, a polymerization inhibitor, a mold release agent, a leveling agent and the like as necessary.
Examples of the organic solvent include isopropyl alcohol, methyl ethyl ketone, methyl isobutyl ketone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, toluene and the like.
Examples of the polymerization inhibitor include hydroquinone, methylhydroquinone, 4-methoxyphenol (methoquinone) and the like.
Examples of the release agent include a fluorine-based nonionic surfactant, a silicone-based nonionic surfactant, an alkyl quaternary ammonium salt, a phosphate ester, and a phosphite ester.
Examples of the leveling agent include a copolymer of polyoxyalkylene and polydimethylsiloxane, a copolymer of polyoxyalkylene and fluorocarbon, and the like.
Etc.

  Furthermore, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, tetra (1,2,2,6) , 6-pentamethyl-4-piperidyl) -1,2,3,4-butanetetracarboxylic acid ester, etc., hindered amine light stabilizer having 1,2,2,6,6-pentamethyl-4-piperidyl residue,

Tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, n-octyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, Hindered phenols such as 4,4′-thiobis (3-methyl-6-tert-butylphenol), ditridecyl-3,3′-thiodipropionate, dilauryl-3,3′-thiodipropionate, bis [2-methyl-4- {3-n-alkyl _{(C 12} or _{C 14)} thio propionyloxy} -5-t-butylphenyl] sulfur system such as the sulfides 3,5 di t-butyl-4 An antioxidant having a hydroxyphenyl residue or a 3-methyl-6-tert-butylphenyl residue,

Phosphite-based decolorizing agent,
Antifoaming agent such as silicone oil,
Organic solvents such as alcohols, glycols, aliphatic cyclic ketones, acetate esters,
You may mix | blend well-known additives in the said fields, such as a silane coupling agent, a flame retardant, an antistatic agent, a filler, a matting agent, a photosensitizer, and an ultraviolet absorber.

  Especially, it is preferable to mix | blend the xylene resin whose number average molecular weight (polystyrene conversion value by a gel permeation chromatograph) is 200-600, and the polyfunctional thiol compound which has two or more thiol groups in a molecule | numerator. By blending such a compound, the adhesion to the substrate can be improved.

  Examples of the polyfunctional thiol compound include trimethylolpropane-tris-3-mercaptopropionate, pentaerythritol tetrakis-3-mercaptopropionate, dipentaerythritol-hex-3-mercaptopropionate, 1,4-bis ( 3-mercaptobutyryloxy) butane, 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, pentaerythritol Examples include tetrakis-3-mercaptobutyrate. Among them, 1,4-bis (3-mercaptobutyryloxy) butane, 1,3,5-tris (3-lcaptobutyloxyethyl) -1,3,5-triazine-2,4,6 (1H , 3H, 5H) -trione, pentaerythritol tetrakis-3-mercaptobutyrate. These can also contribute to the improvement of transparency.

  Also, blue or purple dyes or pigments may be added to reduce the number of colors (APHA) of the cured product.

  The refractive index of the resin composition for an optical material of the present invention is suitably 1.60 or more at 25 ° C., preferably 1.61 or more, and more preferably 1.62 or more. The refractive index can be measured by, for example, an Abbe refractometer. By using such a refractive index, it is possible to further improve background reflection or front luminance. In addition, such adjustment of a refractive index can be arbitrarily adjusted with the compounding ratio of a raw material component, for example.

The resin composition for optical materials of the present invention can obtain a cured product by irradiation with active energy rays such as ultraviolet rays. Examples of light sources for active energy rays include xenon lamps, carbon arcs, germicidal lamps, fluorescent lamps for ultraviolet rays, high pressure mercury lamps for copying, medium pressure mercury lamps, high pressure mercury lamps, ultrahigh pressure mercury lamps, electrodeless lamps, metal halide lamps, scanning types or Examples thereof include an electron beam by a curtain type electron beam acceleration path.
In the case of curing using such a light source, the active energy ray dose is suitably about 300 to 3000 mJ / cm ² . In order to sufficiently cure the resin composition, it is desirable to irradiate active energy rays such as ultraviolet rays in an inert gas atmosphere such as nitrogen gas.

  The resin composition for optical materials of the present invention can be cured into a molded product such as a plastic lens. As a method for producing such a molded product, a resin composition is injected between a gasket made of polyvinyl chloride, an ethylene vinyl acetate copolymer, etc. and two molds having a desired shape, and then an active energy such as ultraviolet rays is used. Examples thereof include a method of curing the resin composition obtained in the present invention by irradiating a wire and peeling the cured product from the mold.

  Moreover, you may form the resin composition for optical materials of this invention as a coating layer with respect to a target object. Specifically, methods such as brush coating, bar coater, applicator, roll coater, roller brush, etc., spray coating using an air spray or airless spray coater, shower coater, curtain flow coater, etc. The film can be coated by a method of using a flow coating method (flow coating), a dipping method, a casting method, a spin coating method, or the like. These coating methods are preferably selected as appropriate according to the material, shape or application of the object.

  Furthermore, you may shape | mold the resin composition for optical materials of this invention in a film form. The film is formed by a method known in the art, for example, extrusion molding or the like, or a method of forming a coating film on an appropriate base material using the above-described method and curing it, and then peeling the base material. Is exemplified.

The refractive index of the resin composition of the present invention and the cured product thereof can be arbitrarily adjusted. Therefore, it is particularly useful as a material for optical plastic lenses such as prism lens sheets, Fresnel lenses, spectacle lenses, and aspheric lenses. It can also be used for optical electronics, optical fibers, optical waveguides and other optoelectronic applications, printing inks, paints, clear coating agents, glossy varnishes, and the like.
EXAMPLES The present invention will be specifically described below with reference to examples of the resin composition for optical materials and the cured product of the present invention, but the present invention is not limited to these.

[Synthesis example of component A]
A four-necked flask was charged with 590 g of bis-o-phenylphenoxyethanol fluorene, 187.2 g of acrylic acid, 30 g of p-toluenesulfonic acid, 1350 g of toluene, 1 g of hydroquinone monomethyl ether and 0.03 g of hydroquinone, and a stirrer, thermometer, condenser, minute A water bottle was attached. Thereafter, while refluxing at 100 to 120 ° C., a dehydration esterification reaction was performed for about 5 to 6 hours until a theoretical dehydration amount was obtained. Subsequently, the reaction solution was neutralized with alkali and washed with 10% saline. After washing, toluene was removed by concentration under reduced pressure to obtain the above-mentioned compound (a) in the form of a white powder. The refractive index of this compound was 1.647 at 25 ° C. Results The compound was analyzed by FT-IR, and the carbonyl of the ester bonds due to 1730 cm ^-1, confirming the vibration of the double bond of the acryloyl group due to 695cm ^-1.

Example 1
(A) Compound (a) as component, m-phenoxybenzyl acrylate as component (B), Irgacure 184 (hydroxycyclohexyl phenyl ketone; manufactured by Ciba Specialty Co., Ltd.) as component (D), ) :( B) :( D) = 45: 55: 3 (parts by weight) and uniformly stirred to obtain the resin composition of the present invention.
Table 1 shows the physical properties of the obtained resin solution and its cured product.

Examples 2 and 3
Compound (a) as component (A), o-phenylphenoxyethyl acrylate alone or m-phenoxybenzyl acrylate as component (B), and Irgacure 184 (hydroxycyclohexyl phenyl ketone; Ciba Specialty Co., Ltd.) as component (D) In the same manner as in Example 1, the weight ratio shown in Table 1 was used.

Examples 4 and 5
Compound (a) as component (A), m-phenoxybenzyl acrylate alone or benzyl acrylate as component (B), bisphenoxyethanol full orange acrylate as component (C), Irgacure 184 (hydroxycyclohexylphenyl) as component (D) (Ketone; manufactured by Ciba Specialty Co., Ltd.) was used in the same manner as in Example 1 in the weight ratio shown in Table 1.

Examples 6 and 7
(A) Compound (a) as component, m-phenoxybenzyl acrylate alone or o-phenylphenoxyethyl acrylate as component (B), bisphenoxyethanol full orange acrylate as component (C), Irgacure 184 as component (D) (Hydroxycyclohexyl phenyl ketone; manufactured by Ciba Specialty Co., Ltd.) was used in the same manner as in Example 1 in the weight ratio shown in Table 1.

Example 8
(B) It mix | blended with the composition similar to Example 1, and the weight ratio of Table 1 except having changed the weight ratio of a component.

Comparative Examples 1 and 2
(B) m-phenoxybenzyl acrylate or o-phenylphenoxyethyl acrylate as the component, bisphenoxyethanol full orange acrylate as the component (C), Irgacure 184 (hydroxycyclohexyl phenyl ketone; manufactured by Ciba Specialty Co., Ltd.) as the component (D) Used in the same manner as in Example 1 in the weight ratio shown in Table 1.

Comparative Example 3
(B) m-phenoxybenzyl acrylate and benzyl acrylate are used in combination, bisphenoxyethanol full orange acrylate is used as component (C), and Irgacure 184 (hydroxycyclohexyl phenyl ketone; manufactured by Ciba Specialty Co., Ltd.) is used as component (D). In the same manner as in Example 1, the weight ratios shown in Table 1 were blended.

Comparative Examples 4 and 5
In the same manner as in Example 1, using benzyl acrylate as component (B), bisphenoxyethanol full orange acrylate as component (C), and Irgacure 184 (hydroxycyclohexyl phenyl ketone; manufactured by Ciba Specialty Co., Ltd.) as component (D). The weight ratios shown in Table 1 were blended.

note)
(A) Component: bis-o-phenylphenoxyethanol full orange acrylate (B) Component 1: m-phenoxybenzyl acrylate (B) Component 2: o-phenylphenoxyethyl acrylate (B) Component 3: benzyl acrylate (C) Component: Bisphenoxyethanol full orange acrylate (D) Component: Hydroxycyclohexyl phenyl ketone * 1) Refractive index: Measured with Abbe refractometer * 2) Curling property: 100 μm, easy-adhesion PET film coated with a film thickness of 80 μm, 600 mJ / cm After curing by irradiating ² ultraviolet rays, it was cut into 6 cm squares, and the average of the heights (mm) of the warps at the 4 corners was calculated.
* 3) Adhesion: 100 μm easy-adhesive PET film (A-4300 manufactured by Toyobo Co., Ltd.) coated at a film thickness of 80 μm, cured by irradiating with 600 mJ / cm ² of ultraviolet rays, and then laid according to JISK5400 An eye cellophane tape peel test was performed, and the peeled state of the grid was observed and evaluated at 0/100 to 100/100.

As shown in Table 1, in all examples, curling property was small, adhesion was good, and a high refractive index was obtained.
On the other hand, in the comparative example, the refractive index was low, and in Comparative Example 5, warping due to curling was strongly expressed.

  The resin composition for optical materials and the cured product of the present invention are optical articles made of various plastic materials such as liquid crystal display panels, color filter protective films, spectacle lenses, Fresnel lenses, lenticular lenses, prism lens sheets, The present invention can be applied to various articles such as spherical lenses, optical disk coating agents and adhesives, optical fiber core materials and clad materials, optical fiber connection adhesives, optical waveguide core materials and clad materials.

Claims (5)

Difunctional (meth) acrylate bets compound having a fluorene skeleton represented by formula (1) and (A), containing at least one monofunctional (meth) acrylate compound (B),
The monofunctional (meth) acrylate compound (B) is selected from the group consisting of benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, m-phenoxybenzyl (meth) acrylate and o-phenylphenoxyethyl (meth) acrylate. A resin composition for optical materials, characterized in that it is at least one kind .
(In formula, R < ¹ > and R < ² > are the same or different, a hydrogen atom or a methyl group, and a and b represent the integer of 1-4, respectively.)   Furthermore, the resin composition for optical materials of Claim 1 containing (meth) acrylate compounds (C) other than a monofunctional (meth) acrylate compound (B). Furthermore, the resin composition for optical materials of Claim 1 or 2 containing a photoinitiator (D). The resin composition for optical materials according to any one of claims 1 to 3 , wherein the refractive index is 1.60 or more at 25 ° C. Hardened | cured material obtained by hardening the resin composition for optical materials as described in any one of Claims 1-4 .