Divinylbenzylfluorene compound, production method thereof, curable resin composition obtained therefrom, cured product of curable resin, optical article and imaging device

Abstract

To provide a new divinylbenzyl fluorene compound having improved characteristics such as transparency and solubility, a method for producing the compound, a curable resin composition obtained from the same, a curable resin cured product, an optical article and an imaging device.SOLUTION: A divinylbenzyl fluorene compound is represented by the following general formula (1), wherein when the compound is measured at a rate of temperature rise of 10°C / min using a differential scanning calorimeter, the compound has a melting point of 130°C or lower or does not have a melting point. In the formula, R1 independently represents one substituent selected from a 1-5C alkyl group, an alkoxy group, a thioalkoxy group, a 6-30C aryl group and a 3-30C heteroaryl group, and x independently represents an integer of 0-4.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a divinylbenzylfluorene compound having excellent processability, transparency and high refractive index, a method for producing the same, a curable resin composition obtained therefrom, a cured product of the curable resin obtained by curing the same, an optical article and an imaging device including the same.

Background Art

[0002] In recent years, resin materials have been widely used for optical parts such as optical overcoat agents, hard coat agents, antireflection films, spectacle lenses, optical fibers, optical waveguides, holograms, and optical elements of various cameras, because they are excellent in processing and productivity. Further, there is a demand for resin materials having a high refractive index from the viewpoints of miniaturization and thinning of optical parts, or adjustment of antireflection properties. In particular, in recent years, in liquid crystal display elements used for displays such as liquid crystal televisions, notebook personal computers, portable game machines, and mobile phones, there have been increasing demands for miniaturization, high resistance, and high brightness. To achieve this, it is essential to increase the refractive index of the prism sheet. To manufacture a shaped material such as a prism sheet, an optical material having a high refractive index and a low viscosity is required. However, conventional resin materials have problems that the viscosity increases when the refractive index is increased, and further, crystallization occurs. In addition, optical glass or optically transparent resin is used as a material for optical elements used in optical systems of various cameras such as cameras, film-integrated cameras, and video cameras. Optical glass is excellent in heat resistance, transparency, dimensional stability, chemical resistance, etc., and there are various types of materials having various refractive indices and Abbe numbers. However, it has problems of high material cost, poor molding processability, and low productivity. In particular, processing into an aspherical lens used for aberration correction requires extremely advanced technology and high costs, which is a major practical obstacle. Regarding the above optical glass, an optical lens made of an optical transparent resin has the advantages of excellent moldability, being capable of mass production, and being easy to manufacture an aspherical lens, and is currently used for camera lens applications. Examples of optical transparent resins with a high refractive index include polycarbonate, polyester, or episulfide compounds.

[0003] In recent years, as an optical material with a high refractive index, in order to provide a material with a high refractive index, compounds having a fluorene skeleton have been proposed. For example, a bifunctional compound in which an acryloyl group is bonded to a fluorene skeleton via an alkyleneoxy group (Patent Documents 1, 2, 3), and a compound obtained by reacting a diglycidyl ether containing a fluorene skeleton with acrylic acid or methacrylic acid (Patent Document 4) are known, and these have attracted attention for their high heat resistance and high refractive index. However, since the bulky and rigid derivatives of fluorene described above are generally solids or high-viscosity liquids of several tens of Pa·s or more at room temperature, when used as a shaping material such as a prism sheet, it is necessary to dilute with a large amount of a reactive diluent or the like to obtain an appropriate viscosity, and thus there has been a problem that the refractive index of the obtained cured product becomes low.

[0004] On the other hand, Patent Document 5 discloses a curable polyvinylbenzyl compound obtained by reacting a fluorene compound and vinylbenzyl halide in the presence of an alkali. However, due to the m- / p-isomer ratio of the vinylbenzyl unit used in the divinylbenzylfluorene disclosed in the patent gazette being a 50 / 50 wt% mixture, it has high crystallinity and low solubility in a reactive diluent, so when trying to use it for an optical component that requires transparency, there is a problem that haze is generated and only a molded product with low transparency can be obtained.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] Accordingly, an object of the present invention is to provide a novel divinylbenzylfluorene compound having improved properties such as transparency and solubility, a method for producing the compound, a curable resin composition obtained therefrom, a cured product of the curable resin, an optical article, and an imaging device. [Means for Solving the Problems]

[0007] A compound having a plurality of vinyl groups in the molecule easily undergoes an intermolecular crosslinking reaction by polymerization. By utilizing this property, such a compound is added to a polymerization system and copolymerized to form a crosslinked body, whereby it is possible to insolubilize a polymer or impart functionality. For example, divinylbenzene can be mentioned as a compound having a plurality of vinyl groups in the molecule. By adding a small amount of this to a styrene polymerization system and copolymerizing it, and further introducing a functional group such as a sulfonic acid group, it can be used as an ion exchange resin. In addition, it can be used as a crosslinking agent for styrene-based resins such as synthetic rubber, ABS resin, MBS resin, and unsaturated polyester resin, and as a modifier for polyethylene. As another example, by copolymerizing with a transparent resin system such as (meth)acrylate, it may be possible to impart functionality such as strength and heat resistance to optical materials such as optical waveguides and optical lenses.

[0008] Specifically, divinylbenzylfluorene compounds disclosed in Patent Document 5 are known. However, due to the fact that the m- / p-isomer ratio of the vinylbenzyl units used is a 50 / 50 wt% mixture, the melting point is as high as 145°C, and no divinylbenzylfluorene compounds with a melting point of 130°C or lower have been reported.

[0009] Under such circumstances, as a result of intensive studies to achieve the above problems, the inventors of the present invention synthesized a divinylbenzylfluorene compound in which the m- / p-isomer ratio of the vinylbenzyl units is 0.6 to 1.0. As a result, the melting point is 130°C or lower, and the solubility in a reactive diluent is also improved. Moreover, it was surprisingly found that the molded cured product of the divinylbenzylfluorene compound in which the ratio of the m- / p-isomers of the vinylbenzyl units is within a specific range has sufficiently improved optical properties such as total light transmittance and haze, and has a high refractive index, thus completing the present invention.

[0010] That is, the present invention is a divinylbenzylfluorene compound represented by the following general formula (1):

Chemical formula

[0011] The present invention relates to a method for producing a divinylbenzylfluorene compound, which comprises reacting one or more fluorene compounds represented by the following general formula (2) with a vinylbenzyl halide having a ratio of p-isomer / (m-isomer + p-isomer) of 0.6 to 1.0 in the presence of an alkali.

Chemical formula

[0012] The present invention relates to a curable resin composition characterized in that the above divinylbenzylfluorene compound is blended with a monomer, oligomer and / or polymer copolymerizable with the divinylbenzylfluorene compound. Furthermore, the present invention relates to a resin cured product obtained by curing the above curable resin composition, an optical article comprising the cured product of the curable resin, and an imaging device in which the optical article is incorporated.

Advantages of the Invention

[0013] The divinylbenzylfluorene compound of the present invention has improved solubility, and its molded cured product has improved optical properties such as transmittance, haze, and refractive index, and is useful as an optical material and various modifiers.

Embodiments for Carrying Out the Invention

[0014] Hereinafter, the divinylbenzylfluorene compound, curable resin composition of the present invention, and each component blended therein will be described in detail.

[0015] The divinylbenzylfluorene compound of the present invention is a divinylbenzylfluorene compound represented by the above general formula (1) having two polymerizable unsaturated bonds, and when measured using a differential scanning calorimeter at a heating rate of 10 ° C. / min, it has a melting point of 130 ° C. or lower, or does not have a melting point. It is a divinylbenzylfluorene compound characterized by that.

[0016] It is essential that the divinylbenzylfluorene compound of the present invention has a melting point of 130 ° C. or lower or does not have a melting point, but it is more preferably 125 ° C. or lower, and most preferably 120 ° C. or lower. When the melting point of the divinylbenzylfluorene compound exceeds 130 ° C., the crystallinity increases, and it overlaps with the thermal polymerization initiation temperature of the vinyl group, resulting in deteriorated processability and reduced transparency of the molded cured product.

[0017] In the above general formula (1), R 1 independently represents one substituent selected from a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group, a thioalkoxy group, an aryl group having 6 to 30 carbon atoms, and a heteroaryl group having 3 to 30 carbon atoms, preferably an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 30 carbon atoms or a heteroaryl group having 3 to 30 carbon atoms. More preferably, it is an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, a heteroaryl group having 6 to 12 carbon atoms, and even more preferably an alkyl group having 1 to 3 carbon atoms. x is the number of substituents and independently represents an integer of 0 to 4, preferably an integer of 0 to 2, and more preferably 0.

[0018] In the divinylbenzylfluorene compound, the ratio of the p-isomer / (m-isomer + p-isomer) of the vinylbenzyl group is preferably 0.6 to 1.0, more preferably 0.8 or more, and even more preferably 0.9 or more. Although 1.0 is ideal, in reality, the upper limit is 0.995, more preferably 0.99, and even more preferably 0.98. Regarding the o-isomer, from the perspective of thermal stability, it is desirable not to contain it. Even if it is contained, it is less than 5 mol% with respect to all vinylbenzyl groups. In other words, in all vinylbenzyl groups, the total amount of the p-isomer and the m-isomer is 95 mol% or more, more preferably 99 mol% or more.

[0019] Here, the structure of the p-isomer of the divinylbenzylfluorene compound is exemplified by the following general formula (3).

Chemical formula

[0020] The structure of the m-isomer of the divinylbenzylfluorene compound is exemplified by the following general formula (3).

Chemical formula

[0021] As the fluorene compound used in the synthesis of the divinylbenzylfluorene compound of the present invention, as shown in the above general formula (2), unsubstituted fluorene, or a fluorene compound in which the aromatic ring portion thereof is substituted with an alkyl group, an alkoxy group, a thioalkoxy group, an aryl group or a heteroaryl group can be mentioned, and these may be used alone or in combination of two or more compounds. Among these, the most suitable fluorene compound that is easily available and industrially feasible is unsubstituted fluorene.

[0022] Next, as the vinylbenzyl halide used in the synthesis of the divinylbenzylfluorene compound of the present invention, m-vinylbenzyl chloride, p-vinylbenzyl chloride, m-vinylbenzyl bromide, p-vinylbenzyl bromide, etc. can be mentioned, and these may be used alone or in combination of two or more compounds. Among the above, m-vinylbenzyl chloride and p-vinylbenzyl chloride are the most preferable in terms of easy availability and industrial implementation.

[0023] Furthermore, when vinylbenzyl halide is used in the synthesis of the divinylbenzylfluorene compound of the present invention, by setting the ratio of p-isomer / (m-isomer + p-isomer) to 0.6 to 1.0, a novel divinylbenzylfluorene compound with improved properties such as transparency, solubility, and processability can be obtained.

[0024] Regarding vinylbenzyl halide as a raw material, for the ratio of p-isomer / (m-isomer + p-isomer), the lower limit is preferably 0.7, more preferably 0.8, and even more preferably 0.9. On the other hand, from the perspective of the price or ease of production of vinylbenzyl halide, the upper limit is preferably 0.995, more preferably 0.99, and even more preferably 0.98. When the ratio of p-isomer / (m-isomer + p-isomer) is less than 0.6, the crystallinity and melting point of the resulting divinylbenzylfluorene compound increase, the solubility in the reactive diluent deteriorates, and it also overlaps with the thermal polymerization initiation temperature of the vinyl group, so the transparency of the molded cured product decreases.

[0025] The synthesis of the divinylbenzylfluorene compound of the present invention can be obtained by reacting one or more kinds of fluorene or fluorene compounds represented by the general formula (2) with vinylbenzyl halide in the presence of an alkali. If necessary, a dihalomethyl compound having 2 to 20 carbon atoms may be added. This reaction can be carried out according to the conditions of a known vinylbenzylation reaction. The vinylbenzylation reaction can be carried out, for example, by the methods described in L.J. Mathias et al., J. Polym. Sci., Part B;, 2869 (1998), J. Polym. Sci., Part A;, 587 (1997) or C.J. Kelly et al., J. Chem. Res. (S), 446 (1997).

[0026] Examples of the reaction solvent include aprotic polar solvents such as dimethylformamide, dimethyl sulfoxide, dimethylacetamide, N-methylpyrrolidone, dioxane, acetonitrile, tetrahydrofuran, ethylene glycol dimethyl ether, 1,3-dimethoxypropane, 1,2-dimethoxypropane, tetramethylene sulfone, hexamethylphosphoramide, methyl ethyl ketone, methyl isobutyl ketone, acetone, cyclohexanone, etc., aromatic solvents such as benzene, toluene, xylene, etc., and mixtures thereof. A solvent species that makes the reaction system uniform may be selected from these according to the raw material species and reaction conditions.

[0027] Examples of the alkali used in this reaction include alkoxides, hydrides, and hydroxides of alkali metals or alkaline earth metals, such as sodium methoxide, sodium ethoxide, sodium hydride, sodium borohydride, potassium hydride, potassium hydroxide, etc. The alkali species may be selected depending on whether the reaction system is non-aqueous or water-containing. The usage ratio of the alkali is preferably about 1.1 to 3.0 equivalents relative to 1 equivalent of the hydrogen at the 9-position of the starting fluorene compound. If it is less than 1 equivalent, the reaction rate will be significantly slowed down, the reaction will not proceed completely, and raw materials will remain, which will have an unfavorable effect on the cured physical properties. Also, even if it is used in excess of 3 equivalents, a large amount of removal solvent such as washing water is used for the removal of the residual alkali, which is not economical.

[0028] A phase transfer catalyst can be used during the reaction. Examples of this phase transfer catalyst include various onium salts, such as quaternary ammonium compounds like tetra-n-butylammonium bromide, tetra-n-butylammonium hydrogen sulfate, benzyltrimethylammonium chloride, tricaprylmethylammonium chloride, etc., quaternary phosphonium compounds like tetra-n-butylphosphonium bromide, benzyltriphenylphosphonium chloride, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, etc., tertiary sulfonium compounds like benzyltetramethylene sulfonium bromide, and mixtures thereof. Since the amount of these phase transfer catalysts used varies depending on the catalyst species or reaction temperature, it cannot be generally specified. However, generally, an amount of about 0.01 to 0.2 equivalents may be used with respect to 1 equivalent of the hydrogen at the 9-position of the starting fluorene compound.

[0029] Since the reaction temperature and reaction time vary depending on the type of starting compound used and the reaction conditions, they cannot be generally specified. However, they may be 30 to 100 °C and 0.5 to 20 hours, respectively. At a reaction temperature exceeding 100 °C, undesirable reactions such as thermal polymerization often occur simultaneously. On the other hand, although the reaction proceeds at a temperature below 30 °C, it takes a long time and is not economical.

[0030] In the present invention, since an unsaturated halide having a high thermal polymerizability such as vinylbenzyl halide is used, a polymerization inhibitor may be added to the reaction system as necessary. Examples include t-butylcatechol, 2,4-di-t-butylphenol, 2-t-butylphenol, 2-t-butyl-4-nitrophenol, 2,4-dinitrophenol, hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, t-butylhydroquinone, resorcinol, pyrogallol, phenothiazine, copper salts, and the like. Furthermore, the use of an appropriate amount of air is also effective in inhibiting polymerization. Since the amount of these polymerization inhibitors used varies depending on the type of polymerization inhibitor, it cannot be generally specified. However, it is approximately several ppm to 2000 ppm with respect to the curable vinylbenzyl compound.

[0031] The divinylbenzylfluorene compound of the present invention can be compounded with monomers, oligomers, and / or polymers copolymerizable therewith within a range that does not inhibit the effects of the present invention to form a curable resin composition for improving moldability and the like. Specific examples include oligomers or polymers having polymerizable unsaturated groups such as vinyl ester resins, unsaturated polyester resins, diallyl phthalate resins, maleimide resins, and polysocyanate resins of polyphenols, monomers and prepolymers such as triallyl isocyanurate and triallyl cyanurate, styrene, vinyltoluene, divinylbenzene, vinylbenzyl ether compounds, monofunctional or polyfunctional (meth)acrylic acid derivative compounds, and the like.

[0032] When using copolymerizable monomers, oligomers, and / or polymers, the amount used varies depending on their type, compatibility with the divinylbenzylfluorene compound of the present invention, the use of the cured product, etc., and thus cannot be generally specified. However, with respect to 100 parts by weight of the divinylbenzylfluorene compound of the present invention, for example, it is 10 to 300 parts by weight, preferably 20 to 200 parts by weight, more preferably 50 to 150 parts by weight. When the addition amount exceeds 300 parts by weight, separation, exudation, etc. from the divinylbenzyl compound of the present invention are likely to occur.

[0033] The divinylbenzyl compound and the curable resin composition of the present invention can be cured by adopting known methods such as heat, light, and electron beams. It is also useful to use a curing agent to lower the curing temperature or accelerate the curing reaction. The cured product can be suitably used for optical members in the fields of optical and electronic devices such as optical lenses.

[0034] When using a curing agent, examples include benzoyl peroxide, cumene hydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, t-butylcumyl peroxide, methyl ethyl ketone peroxide, dicumyl peroxide, t-butyl perbenzoate, etc., and these can be used according to the application. The amount used varies depending on the type and concentration of the unsaturated group in the divinylbenzyl compound or curable resin composition of the present invention, the type of curing agent used, the half-life temperature, the required stability, etc., but is generally 0.1 to 10 parts by weight with respect to 100 parts by weight of the divinylbenzylfluorene compound or curable resin composition of the present invention.

[0035] When photocuring, it is advisable to use a photoinitiator. Since the divinylbenzylfluorene compound of the present invention has a vinyl group (ethylenically unsaturated group) that is radically polymerizable as a polymerizable compound, a photo radical initiator can be used. Examples of the photoinitiator include benzoins such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, and benzoin isobutyl ether; acetophenones such as acetophenone, 2,2 - diethoxy - 2 - phenylacetophenone, 2,2 - diethoxy - 2 - phenylacetophenone, 1,1 - dichloroacetophenone, 2 - hydroxy - 2 - methyl - phenylpropan - 1 - one, diethoxyacetophenone, 1 - hydroxycyclohexylphenyl ketone, 2 - methyl - 1 - [4 - (methylthio)phenyl] - 2 - morpholinopropan - 1 - one; anthraquinones such as 2 - ethylanthraquinone, 2 - tertiary butylanthraquinone, 2 - chloroanthraquinone, 2 - amylanthraquinone; thioxanthones such as 2,4 - diethylthioxanthone, 2 - isopropylthioxanthone, 2 - chlorothioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone, 4 - benzoyl - 4'-methyldiphenyl sulfide, 4,4'-bis(methylamino)benzophenone; phosphine oxides such as 2,4,6 - trimethylbenzoyldiphenylphosphine oxide and bis(2,4,6 - trimethylbenzoyl)phenylphosphine oxide, etc.

[0036] These can be used alone or as a mixture of two or more, and can further be used in combination with accelerators such as tertiary amines such as triethanolamine and methyldiethanolamine, and benzoic acid derivatives such as ethyl N,N-dimethylaminobenzoate and isoamyl N,N-dimethylaminobenzoate.

[0037] Examples of commercially available photoinitiators include Irgacure 184, 369, 651, 500, 819, 907, 784, 2959, CGI-1700, -1750, -1850, CG24-61, Darocur l116, 1173 (manufactured by Ciba Specialty Chemicals Co., Ltd.), Lucirin TPO, LR8893, LR8970 (manufactured by BASF), Ubecryl P36 (manufactured by UCB), etc. The amount used is, for example, 0.1 to 10 parts by weight with respect to 100 parts by weight of the divinylbenzylfluorene compound or the curable resin composition of the present invention.

[0038] In addition, known curing accelerators such as manganese naphthenate, lead naphthenate, zinc naphthenate, cobalt naphthenate, zinc octylate, dimethylaniline, and phenylmorpholine can also be used.

[0039] The curing temperature varies depending on the type of polymerizable unsaturated group, the type and amount of the curing agent, etc., and thus cannot be generally defined, but is 20 to 250°C, preferably 50 to 250°C. If the curing temperature is less than 20°C, curing may be insufficient. Also, for adjusting the curing conditions, known curing retarders such as hydroquinone, benzoquinone, and copper salts may be blended.

[0040] Furthermore, if necessary, antioxidants, mold release agents, photosensitizers, organic solvents, silane coupling agents, leveling agents, defoaming agents, antistatic agents, and furthermore ultraviolet absorbers, light stabilizers, various inorganic and organic fillers, antifungal agents, antibacterial agents, etc. can be added to the curable resin composition of the present invention to impart the respective desired functionalities.

[0041] The curable resin composition of the present invention can be obtained by mixing each component in an arbitrary order. The curable resin composition of the present invention is stable over time.

[0042] The curable resin composition of the present invention can obtain a cured product by irradiating active energy rays such as ultraviolet rays. Here, specific examples of the light source used when irradiating active energy rays for curing include, for example, 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, ultra-high-pressure mercury lamps, electrodeless lamps, metal halide lamps, or electron beams by a scanning type or curtain type electron beam accelerator path and the like. Further, when the curable resin composition of the present invention is cured by ultraviolet irradiation, the ultraviolet irradiation amount required for curing may be about 300 to 20,000 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.

[0043] The curable resin composition of the present invention can be used for castings such as plastic lenses. As a method for producing a plastic lens using the resin composition of the present invention, a mold made of a gasket made of polyvinyl chloride, ethylene vinyl acetate copolymer, etc. and two glass molds of a desired shape is made, and the resin composition of the present invention is injected therein, and then active energy rays such as ultraviolet rays are irradiated to cure the resin composition, and the cured product is peeled off from the mold.

[0044] As a method of applying the curable resin composition of the present invention to a film-like substrate as a resin composition for a prism lens sheet, various methods known in the art can be used. Specific methods include, for example, applying the resin composition onto a mold having the shape of a prism lens on its surface to provide a layer of the resin composition, and then pressure-bonding a colorless and transparent film-like substrate (e.g., polyvinyl chloride, polystyrene, polycarbonate, poly(meth)acrylate, polyester, polyethylene terephthalate, etc.) onto the resin composition layer so that no bubbles are trapped. Next, in this state, ultraviolet rays are irradiated from the film-like substrate side using a high-pressure mercury lamp to cure the layer of the resin composition, and then a method of peeling the film-like substrate having a prism lens-shaped resin layer from the mold can be mentioned.

[0045] The refractive index of the cured product of the resin composition for an optical material of the present invention obtained by irradiating with active energy rays such as ultraviolet rays is preferably 1.59 or more at 25 ° C, more preferably 1.60 or more at 25 ° C. Particularly preferably, it is 1.62 or more at 25 ° C. In particular, when producing a prism lens sheet with the curable resin composition for an optical material of the present invention, if the refractive index of the cured product is less than 1.59 at 25 ° C, there may be a problem that sufficient front luminance cannot be ensured.

[0046] The Abbe number of the cured product of the present invention is preferably 40.0 or less, more preferably 30.0 or less. If the Abbe number of the cured product exceeds 40.0, when thinning the imaging device, chromatic aberration is large and color bleeding occurs, which is not preferable.

[0047] The water absorption rate of the cured product of the present invention is preferably 1.0 wt% or less, more preferably 0.5 wt% or less. Particularly preferably, it is 0.35 wt% or less, and most preferably 0.2 wt% or less. When the water absorption rate of the cured product exceeds 1.0 wt%, the refractive index of the material changes with water absorption, so chromatic aberration tends to increase and color bleeding occurs.

[0048] The resin cured product obtained by molding and curing the curable resin composition of the present invention can be suitably used as an optical article. Among optical articles, it is particularly useful as an optical lens such as a prism lens sheet, a Fresnel lens, a lenticular lens, an eyeglass lens, and an aspherical lens. And such an optical lens is suitably incorporated into an imaging device. Further, the curable resin composition or the resin cured product of the present invention can also be used for other optical articles for optoelectronics such as optical disks, optical fibers, and optical waveguides, multilayer substrates, prepregs, metal foils with resin, printing inks, paints, clear coat agents, and surface gloss agents.

[0049] Hereinafter, an imaging device incorporating an optical article, which is one of the embodiments of the present invention, will be exemplified. The optical article of the present invention can be suitably used in various devices equipped with a lens module for an imaging device, such as a camera, a computer, a word processor, a printer, a copier, a fax, a telephone, a mobile device (a portable information terminal (PDA) such as a mobile phone, a smartphone, a game device, and a tablet), an automotive device, a construction device, and an astronomical device. In particular, it is useful as a lens module for a small imaging device (moreover, a high-precision lens), such as a lens module for a small camera (for example, a camera for a mobile phone (the camera of a so-called camera-equipped mobile phone), an in-vehicle camera module, etc.). Portable electronic terminals such as mobile phones, smartphones, game devices, and tablets are equipped with small and thin imaging devices. Such an imaging device is provided with a light receiving element and a lens for forming a subject image on the light receiving element. As the lens module used in the imaging device, for example, it can be used in the imaging devices disclosed in JP-A-2010-266664, JP-A-2003-046825, JP-A-2006-313185, JP-A-2003-032525, WO2011 / 074531, etc. The optical lens of the present invention can be suitably used as the lens or lens part of the imaging device exemplified as above.

Examples

[0050] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. In each example, parts are in parts by weight unless otherwise specified, and the evaluation of each physical property was carried out by the method shown below.

[0051] 1) Molecular weight and molecular weight distribution For the measurement of molecular weight and molecular weight distribution, GPC (manufactured by Tosoh Corporation, HLC-8220GPC) was used. As the analytical column, two TSKgel MultiporeH XL -M: 2 pieces, one TSKgel G1000H XL : 1 piece, and one TSKguardcolumn MP(XL) was used as the guard column. Tetrahydrofuran (THF) was used as the solvent, the flow rate was 1.0 ml / min, the column temperature was 38 °C, and the calibration curve based on monodisperse polystyrene was used.

[0052] 2) Structure of divinylbenzylfluorene compound Using a JNM-LA600 type nuclear magnetic resonance spectrometer manufactured by JEOL Ltd., 13 C-NMR and 1 It was determined by H-NMR analysis. Chloroform-d1 was used as the solvent, and the resonance line of tetramethylsilane was used as the internal standard. In addition, the mass of the divinylbenzylfluorene compound was measured by performing FD-MS analysis using an M-80B type mass spectrometer manufactured by Hitachi, Ltd.

[0053] 3) Measurement of glass transition temperature (Tg), melting point (Tm), and softening temperature The divinylbenzylfluorene compound was uniformly coated on a glass substrate to a dry thickness of 20 μm, and then heated on a hot plate at 90 °C for 30 minutes to dry. The resulting resin film on the glass substrate was set together with the glass substrate in a TMA (Thermomechanical Analyzer) measuring device, and heated to 220 °C at a heating rate of 10 °C / min under a nitrogen stream, and further heat-treated at 220 °C for 20 minutes to remove the remaining solvent. After the glass substrate was allowed to cool to room temperature, an analysis probe was brought into contact with the sample in the TMA measuring device, and measurement was performed by scanning from 30 °C to 360 °C at a heating rate of 10 °C / min under a nitrogen stream, and the softening temperature was determined by the tangent method. Depending on the heat resistance of the sample, when the probe did not penetrate the resin film and showed a probe penetration amount smaller than the film thickness, it was indicated as being equal to or higher than the highest temperature at which the probe did not penetrate as an index of the softening temperature. The melting point of the divinylbenzylfluorene compound was measured using a DSC (Differential Scanning Calorimeter) by scanning from -20 °C to 320 °C at a heating rate of 10 °C / min under a nitrogen stream.

[0054] 4) Measurement of weight loss at 300 °C, heat discoloration resistance, and solder heat resistance test The measurement of the weight loss at 300 °C and heat discoloration resistance of the divinylbenzylfluorene compound was carried out by setting the sample in a TGA (Thermogravimetric Analyzer) measuring device and scanning from 30 °C to 320 °C at a heating rate of 10 °C / min under a nitrogen stream to determine the weight loss at 300 °C, and visually checking the amount of discoloration of the sample after measurement, and classifying it as A: no heat discoloration, B: light yellow, C: brown, D: black to evaluate the heat discoloration resistance. Furthermore, the solder heat resistance test of the divinylbenzylfluorene compound was performed by immersing a cured test piece sheet with a thickness of 2.0 mm and a size of 10 mm square in a lead-free solder bath at 280 °C for 30 seconds, then pulling up the test piece, and visually checking the change in the shape of the test piece after immersion, and classifying it as A: no change, B: warpage, C: deformation / swelling to evaluate the solder heat resistance.

[0055] 5) Measurement of solvent resistance The solvent resistance of the divinylbenzylfluorene compound was measured by immersing the cured sample plate in toluene at room temperature for 10 minutes by vacuum press molding, visually checking the change of the sample after immersion, and classifying it into A: no change, B: swelling, and C: deformation and swelling to evaluate the solvent resistance.

[0056] 6) Measurement of Haze and total light transmittance A flat plate test piece with a thickness of 2 mm or 200 μm was prepared, and Haze (turbidity) and total light transmittance were measured using a spectroscopic color difference meter (manufactured by Nippon Denshoku Industries Co., Ltd., SZ-Σ90).

[0057] 7) Refractive index and Abbe number A test piece of 4 cm × 0.8 cm was prepared, and the refractive index and Abbe number were measured using a multi-wavelength Abbe refractometer (manufactured by Atago Co., Ltd., "Multi-wavelength Abbe refractometer DR-M2"). As the intermediate liquid, a methylene iodide solution with a higher refractive index than the sample was used, and the refractive index and Abbe number were measured using an interference filter for D line 589 nm.

[0058] 8) Spectral transmittance Using a parallel flat plate with a thickness of 1.0 mm as a test piece, the spectral transmittance at a wavelength of 400 nm was measured using a spectrophotometer (manufactured by Konica Minolta, Inc., "CM-3600d"). The measurement timing was before the heat resistance test with post-curing at 190 °C for 60 minutes and after the heat resistance test at 260 °C for 8 minutes in an air oven.

[0059] 9) Water absorption rate A flat plate sample with a thickness of 1 mm, a width of 30 mm, and a length of 30 mm was prepared, dried under vacuum at 100 °C for 2 hours, cooled to room temperature, and then left standing in a desiccator until it reached a constant weight. The mass of the sample at a constant weight was taken as the initial value (m0). Next, this sample was left in a thermo-hygrostat at 85 °C and a relative humidity of 85% for 500 hours, and then the mass (md) was measured. The water absorption rate was measured using the following formula from the change in the initial value and the mass after immersion. (md―m0)×100 / m0 = water absorption rate (%)

[0060] Example 1: Synthesis of Divinylbenzylfluorene Compound (A-1) 203.54 g of fluorene (purity: 98%, 1.20 mol), 800 g of toluene, 18.09 g of tetra-n-butylammonium bromide (purity: 98%, 0.055 mol), 2.78 g of hydroquinone (purity: 99%, 0.025 mol), and an aqueous NaOH solution prepared by dissolving 174.42 g of NaOH (purity: 97%, 4.23 mol) in 320 ml of water were charged. The temperature was raised to 60 °C with stirring to form a homogeneous solution. 449.83 g of vinylbenzyl chloride CMS-14 (m- / p-isomer: 5 / 95 wt% mixture) manufactured by AGC Seimi Chemical Co., Ltd. (purity 95%, 2.8 mol) was added dropwise to this solution over 20 minutes, and then the reaction was carried out at 60 - 61 °C for 8 hours. After adding 200 ml of toluene to the obtained green reaction product, the solution was neutralized with 2N hydrochloric acid, washed three times with distilled water, and after removing toluene under reduced pressure, the obtained pale yellow viscous solid was recrystallized from fresh methanol to obtain 349.44 g (yield 72.8%) of a white solid with a melting point of 119 °C from DSC measurement. This was designated as Compound A-1. The confirmation of the structure of Compound A-1 was 1 by 1H-NMR spectrum, 13 13C-NMR spectrum, IR spectrum, and FD-MS measurement. From the FD-MS measurement result, Mw was 400. From these measurement results, the product was divinylbenzylfluorene (in General Formula 1, R 1 is a hydrogen atom). From the NMR spectrum, it was confirmed that the vinylbenzyl unit is a 5 / 95% mixture of m- / p-isomers. When Compound A-1 was dissolved in toluene at a concentration of 10 wt% at room temperature, a transparent solution was obtained, confirming that it has good solubility.

[0061] Compound A-1 was placed in a mold through a 2.0 mm spacer and cured under vacuum at 200 °C for 1 hour using a vacuum press molding machine. The obtained cured sheet was cut out, and measurements of optical properties, tensile properties, and thermal analysis were carried out. As a result, the total light transmittance was 91.3%, the Haze was 0.30, the refractive index was 1.652, the Abbe number was 23.6, the linear expansion coefficient was 83 ppm / °C, the water absorption rate was 0.15%, the solvent resistance was A, and the solder heat resistance was A. Also, as a result of the TMA measurement, the softening temperature was 300°C or higher. As a result of the TGA measurement, the weight loss amount at 300°C was 0.3 wt%, and the heat discoloration resistance was A.

[0062] Comparative Example 1 Synthesis of Divinylbenzylfluorene Compound (B-1) 203.54 g (purity: 98%, 1.20 mol) of fluorene, 800 g of toluene, 18.09 g (purity: 98%, 0.055 mol) of tetra-n-butylammonium bromide, 2.78 g (purity: 99%, 0.025 mol) of hydroquinone, and further, an aqueous NaOH solution prepared by dissolving 174.42 g (purity: 97%, 4.23 mol) of NaOH in 320 ml of water were charged, and the temperature was raised to 60°C with stirring to make a uniform solution. To this solution, 445.14 g (purity 96%, 2.8 mol) of vinylbenzyl chloride VBC (m- / p-isomer: 57 / 43 wt% mixture) manufactured by Dow Chemical was added dropwise over 20 minutes, and then the reaction was carried out at 60 - 61°C for 8 hours. After adding 200 ml of toluene to the obtained green reaction product, the solution was neutralized with 2N hydrochloric acid, washed three times with distilled water, and after removing toluene under reduced pressure, the obtained pale yellow viscous solid was recrystallized from fresh toluene to obtain 324.48 g (yield 67.6%) of a white solid having a melting point of 144°C from DSC measurement. This was designated as Compound B-1. The confirmation of the structure of Compound B-1 was 1 by 1H-NMR spectrum, 13 13C-NMR spectrum, IR spectrum, and FD-MS measurement. From the measurement result of FD-MS, Mw was 400, and from these measurement results, the product divinylbenzylfluorene (in General Formula 1, R 1(where the hydrogen atom), and the vinylbenzyl unit was a 57 / 43% mixture of m- / p-isomers. When Compound B-1 was dissolved in toluene at a concentration of 10 wt% at room temperature, a turbid solution was obtained, confirming that the solubility was insufficient.

[0063] Compound B-1 was placed in a mold through a 2.0 mm spacer and cured under vacuum at 200 °C for 1 hour using a vacuum press molding machine. The obtained cured sheet was cut out, and measurements of optical properties, tensile properties, and thermal analysis were carried out. As a result, the total light transmittance was 89.6%, the Haze was 3.64, the refractive index was 1.648, the Abbe number was 23.9, the linear expansion coefficient was 87 ppm / °C, the water absorption rate was 0.16%, the solvent resistance was A, and the solder heat resistance was A. Also, as a result of the TMA measurement, the softening temperature was 300 °C or higher. As a result of the TGA measurement, the weight loss at 300 °C was 0.4 wt%, and the heat discoloration resistance was A.

[0064] Comparative Example 2 Synthesis of Divinylbenzylfluorene Compound (C-1) 203.54 g of fluorene (purity: 98%, 1.20 mol), 800 g of toluene, 18.09 g of tetra-n-butylammonium bromide (purity: 98%, 0.055 mol), 2.78 g of hydroquinone (purity: 99%, 0.025 mol), and further, an aqueous NaOH solution prepared by dissolving 174.42 g of NaOH (purity: 97%, 4.23 mol) in 320 ml of water were charged, and the temperature was raised to 60 °C with stirring to form a uniform solution. 449.83 g (purity 95%, 2.8 mol) of vinylbenzyl chloride CMS-P (m- / p-isomer: 50 / 50 wt% mixture) manufactured by Seimi Chemical Co., Ltd. was added dropwise to this solution over 20 minutes, and then reacted at 60 - 61 °C for 8 hours. After adding 200 ml of toluene to the obtained green reaction product, the solution was neutralized with 2N hydrochloric acid, washed three times with distilled water, and after removing toluene under reduced pressure, the obtained pale yellow viscous solid was recrystallized from fresh toluene to obtain 313.92 g (yield 65.4%) of a white solid with a melting point of 145 °C from DSC measurement. This was designated as Compound C-1. The confirmation of the structure of Compound C-1 was1 1H-NMR spectrum, 13 13C-NMR spectrum, IR spectrum, and FD-MS measurement were performed. From the FD-MS measurement result, Mw was 400. From these measurement results, the product was divinylbenzylfluorene (in General Formula 1, R 1 is a hydrogen atom), and the vinylbenzyl unit was a 50 / 50% mixture of m- / p-isomers. When Compound C-1 was dissolved in toluene at a concentration of 10 wt% at room temperature, a turbid solution was obtained, confirming that the solubility was insufficient.

[0065] Compound C-1 was placed in a mold through a 2.0-mm spacer and cured under vacuum at 200 °C for 1 hour using a vacuum press molding machine. The obtained cured sheet was cut out, and measurements of optical properties, tensile properties, and thermal analysis were performed. As a result, the total light transmittance was 89.4%, Haze was 4.14, refractive index was 1.649, Abbe number was 23.9, linear expansion coefficient was 88 ppm / °C, water absorption rate was 0.18%, solvent resistance was A, and solder heat resistance was A. Also, as a result of TMA measurement, the softening temperature was 300 °C or higher. As a result of TGA measurement, the weight loss at 300 °C was 0.42 wt%, and the heat discoloration resistance was A.

[0066] Examples 2 and Comparative Examples 3 to 4 Using Compounds A-1, B-1, and C-1 obtained in Example 1 and Comparative Examples 1 and 2, each component was blended at the ratios shown in Table 1 to obtain a curable resin composition. Next, this curable resin composition was cured by various test methods and performance evaluation was performed. The performance evaluation results are also shown in Table 1.

[0067] Copolymerizable monomer: NK Ester A-LEN-10; 2-(o-phenylphenoxy)ethyl acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) Curing agent: Perbutyl P; α,α'-bis(t-butylperoxy)diisopropylbenzene (manufactured by NOF Corporation) Photopolymerization initiator: Irgacure 184; 1-Hydroxy-cyclohexyl-phenyl-ketone (manufactured by Ciba Specialty Chemicals) Stabilizer: Adekastab AO-60; Pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (ADEKA CORPORATION)

[0068]

Table 1

Industrial Applicability

[0069] The divinylbenzylfluorene compound, curable resin composition, and resin cured product obtained by molding and curing the curable resin composition of the present invention are excellent as optical materials. In particular, they are useful as materials for optical plastic lenses such as prism lens sheets, Fresnel lenses, lenticular lenses, spectacle lenses, and aspherical lenses, and such lenses are advantageously used in imaging devices. Further, the curable resin composition or resin cured product of the present invention can also be used for other applications such as optoelectronics applications such as optical disks, optical fibers, and optical waveguides, multilayer substrates, prepregs, metal foils with resin, printing inks, paints, clear coating agents, and gloss agents. The modified vinyl aromatic copolymer of the present invention is also useful as a dielectric material, insulating material, heat-resistant material, structural material, adhesive, sealant, paint, coating agent, sealing material, printing ink, paint, clear coating agent, gloss agent, dispersant, etc. in fields such as the electric and electronic industries, space and aircraft industries, and construction and building industries. It can also be used as a modifier for modifying properties such as the heat resistance, dielectric properties, adhesiveness and adhesion, and optical properties of thermoplastic resins or curable resin compositions.

Claims

1. A divinylbenzylfluorene compound represented by the following general formula (1), wherein the ratio of the p-isomer / (m-isomer + p-isomer) of the vinylbenzyl group is 0.6 to 0.98, 【Chemical 1】 (wherein, R １ independently represents a substituent of an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 30 carbon atoms, and x independently represents an integer of 0 to 2) When measured at a heating rate of 10 ° C. / min using a differential scanning calorimeter, the divinylbenzylfluorene compound is characterized in that the melting point is 130 ° C. or lower or has no melting point.

2. A method for producing a divinylbenzylfluorene compound according to claim 1, comprising reacting one or more fluorene compounds represented by the following general formula (2) with a vinylbenzyl halide having a ratio of p-isomer / (m-isomer + p-isomer) of 0.6 to 0.98 in the presence of an alkali. [Chemical Formula 2] (wherein R １ , x has the same meaning as in the general formula (1). )

3. A curable resin composition comprising the divinylbenzylfluorene compound according to claim 1 and a monomer, oligomer and / or polymer copolymerizable with the divinylbenzylfluorene compound.

4. A resin cured product obtained by curing the curable resin composition according to claim 3.

5. An optical article comprising the cured resin cured product according to claim 4.

6. The optical article according to claim 5, which is an optical lens.

7. An imaging device comprising the optical article according to claim 5.

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