hardened material

Abstract

To provide a cured product having a high refraction index and reflow resistance, and also having little adhesion of foreign substances onto the cured product itself and peripheral members.SOLUTION: A cured product comprises a curable composition containing (meth)acrylate having a fluorene structure. In the cured product, a reaction rate of carbon-carbon double bond shown by following formula (1) is 88% or more: reaction rate (%)=100×{1-(B / A)}...(1); A: peak intensity of absorption at 809 cm-1 in infrared absorption spectrum before curing of the curable composition. B: peak intensity of absorption at 809 cm-1 in infrared absorption spectrum after curing of the curable composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a cured product. [Background technology]

[0002] Surface mounting technology is advancing rapidly, especially in small devices such as mobile phones and laptops. With the spread of lightweight, high-performance electronic devices, electronic components are also rapidly becoming smaller. The camera lens is one of them, and there is a demand for miniaturization, and the refractive index is High thermal conductivity, low Abbe number, high transparency and heat resistance, and low adhesion of foreign matter are required. For example, a camera module for a mobile phone usually contains multiple lenses with different refractive indices. For high refractive index lenses, fluorene polyester resin is mainly used. However, since fluorene-based polyester resin is a thermoplastic resin, it is difficult to solder. It has the disadvantage of being easily melted by heat during flow (poor heat resistance and reflow resistance).

[0003] Resin using (meth)acrylate with fluorene structure to improve reflow resistance A method of introducing a cross-linked structure into the material is known, and it has a high refractive index and excellent transparency. Therefore, it is considered to be useful for various plastic lenses (Patent Documents 1 to 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-94987 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-126991 [Patent Document 3] Japanese Patent Application Laid-Open No. 2012-82387 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the methods of Patent Documents 1 to 3 have insufficient reflow resistance, and vapor formation from the lens These particles can become foreign matter and contaminate the lens itself and its surrounding parts. In applications where visibility is required to be higher than ever before, materials that can attract such foreign matter are The material is not suitable for use.

[0006] The present invention has been made to improve the above-mentioned problems, and provides a high refractive index, high transparency, and To provide a cured product that has reflow resistance and has little adhesion of foreign matter to the cured product itself and surrounding components. The purpose is to: [Means for solving the problem]

[0007] The present invention has the following aspects. [1] A curable composition containing a (meth)acrylate having a fluorene structure. A cured product in which the reaction rate of the carbon-carbon double bond represented by the following formula (1) is 88% or more. cured product. Carbon-carbon double bond reactivity (%) = 100 × {1 - (B / A)} (1) A: 809 cm in the infrared absorption spectrum of the curable composition before curing -1 Absorption peak Arc strength B: 809 cm in the infrared absorption spectrum of the curable composition after curing -1 Absorption peak Arc strength [2] The (meth)acrylate having a fluorene structure is a compound represented by the following formula (2): The cured product according to [1], which is a compound. [ka] In formula (2), R 1 , R 2 , R 3 , R 4 are each independently a hydrogen atom or a methyl group, m represents an integer of 0 to 5; n represents an integer of 0 to 5; [3] The curable composition contains a (meth)- The cured product according to [1] or [2], which contains an acrylate. [4] The curable composition contains a trifunctional or higher polyfunctional (meth)acrylate. [1] The cured product according to any one of [3] to [3]. [5] The curable composition according to any one of [1] to [4], wherein the curable composition contains a polymerization initiator. monster. [6] The curable composition according to any one of [1] to [5], wherein the curable composition contains an antioxidant. monster. [7] A ratio of the total mass of all structural units constituting the curable composition to a mass of a compound having a fluorene structure. Any of [1] to [6], wherein the proportion of the (meth)acrylate is 15 to 95 mass%. 2. The cured product according to claim 1. [8] The amount of biphenyl or fluorine-containing copolymer based on the total mass of all structural units constituting the curable composition. The proportion of (meth)acrylate having a phenoxyphenyl structure is 80 mass% or less, [ The cured product according to any one of items [1] to [7]. [9] A trifunctional or higher multifunctional unit is contained in the curable composition relative to the total mass of all structural units constituting the curable composition. (Meth)acrylate (the fluorene structure, biphenyl structure or phenoxyphenyl The proportion of (excluding (meth)acrylates having the structure) is 50 mass % or less, [1] to [ 8] The cured product according to any one of the above items.

[10] The ratio of the polymerization initiator to the total mass of all structural units constituting the curable composition. The cured product according to any one of [1] to [9], wherein the amount is 10% by mass or less.

[11] The ratio of the antioxidant to the total mass of all structural units constituting the curable composition. The cured product according to any one of [1] to

[10] , wherein the amount is 10% by mass or less.

[12] A lens made of the cured product according to

[11] . [Effects of the Invention]

[0008] According to the present invention, the cured product has reflow resistance and is less likely to adhere to foreign matter on the cured product itself or surrounding components. A cured product can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail. In the present invention, "(meth)acrylate" refers to the total of acrylates or methacrylates. It is a title. The "~" symbol indicates a range of values, and includes the values ​​before and after it as the lower and upper limits. This means:

[0010] <Curable composition> The cured product of the present invention is a curable composition containing a (meth)acrylate having a fluorene structure. The cured product is a composition having a carbon-carbon double bond reaction rate of 88%, as shown in the following formula (1): % or more. Carbon-carbon double bond reactivity (%) = 100 × {1 - (B / A)} (1) A: 809 cm in the infrared absorption spectrum of the curable composition before curing -1 Absorption peak Arc strength B: 809 cm in the infrared absorption spectrum of the curable composition after curing -1 Absorption peak Arc strength

[0011] (Meth)acrylates having a fluorene structure are materials for increasing the refractive index. It has a (meth)acrylate moiety to provide reflow resistance, and is hardened by a radical reaction. As the (meth)acrylate having a fluorene structure, there are known Among these, those with high refractive index and glass transition temperature after curing can be used. The compound of the following formula (2) is preferred because it has a lower viscosity. [ka]

[0012] In formula (2), R 1 , R 2 , R 3 , R 4 are each independently a hydrogen atom or a methyl group, m represents an integer of 0 to 5, and n represents an integer of 0 to 5. Among them, the refractive index of the cured product is high. Because of this and the increased reactivity, 1 and R 4 is preferably a hydrogen atom. From the viewpoint of formability, m and n are each preferably 1 or 2, and more preferably 1. In addition, R 2 and R 3 From the viewpoint of formability, it is better that hydrogen atoms are also present. This is the preferred form.

[0013] The curable composition for forming the cured product contains a compound having a biphenyl or phenoxyphenyl structure. It is preferable that the compound contains a (meth)acrylate having a fluorene structure. The (meth)acrylate has improved solubility in a curable composition, moldability, and high cured product properties. It is used from the viewpoint of adjusting the refractive index, and a conventionally known compound can be used. Examples of (meth)acrylates having a phenyl structure include ortho-phenylpheno Meta-phenylphenoxyethyl (meth)acrylate, meta-phenylphenoxyethyl (meth)acrylate para-phenylphenoxyethyl (meth)acrylate, ortho-phenylphenoxy Dipropyl (meth)acrylate, meta-phenylphenoxypropyl (meth)acrylate acrylate, para-phenylphenoxypropyl (meth)acrylate, ortho-phenylphenoxypropyl Phenoxybutyl (meth)acrylate, meta-phenylphenoxybutyl (meth)acrylate phenylphenoxy acrylate, para-phenylphenoxybutyl (meth)acrylate, etc. Alkyl (meth)acrylate, ortho-phenylphenoxyethoxyethyl (meth)acrylate Acrylate, meta-phenylphenoxyethoxyethyl (meth)acrylate, para-phenylphenoxyethoxyethyl (meth)acrylate Phenylphenoxyalkoxy such as phenylphenoxyethoxyethyl (meth)acrylate Alkyl (meth)acrylate, ortho-biphenylmethyl (meth)acrylate, meth -Biphenylmethyl (meth)acrylate, para-biphenylmethyl (meth)acrylate ortho-biphenylethyl (meth)acrylate, meta-biphenylethyl (meth)acrylate Acrylate, para-biphenylethyl (meth)acrylate, ortho-biphenylpropionate Para-biphenylpropyl (meth)acrylate, meta-biphenylpropyl (meth)acrylate, para-biphenylpropyl (meth)acrylate Phenylpropyl (meth)acrylate, ortho-biphenylbutyl (meth)acrylate butyl (meth)acrylate, para-biphenyl butyl (meth)acrylate Among these, biphenyl alkyl (meth)acrylates such as acrylates can be mentioned. Phenylphenoxyalkyl (meth)acrylate, phenylphenoxyalkoxy Alkyl (meth)acrylate and biphenyl alkyl (meth)acrylate have high refractive index. From this point of view, phenylphenoxyalkyl(meth)acrylate is preferable when solubility and moldability are also taken into consideration. acrylate and phenylphenoxyalkoxyalkyl(meth)acrylate are more preferred. Phenylphenoxyethyl (meth)acrylate is more preferred. Among them, the ortho position is preferred. Furthermore, in consideration of reactivity, acrylate is preferred over methacrylate. These compounds may be used alone or in combination of two or more. stomach.

[0014] Examples of (meth)acrylates having a phenoxyphenyl structure include ortho-phenoxyphenyl. Phenoxyphenylmethyl (meth)acrylate, meta-phenoxyphenylmethyl (meth)acrylate Acrylate, para-phenoxyphenylmethyl (meth)acrylate, ortho-phenoxyphenylmethyl (meth)acrylate Phenoxyphenylethyl (meth)acrylate, meta-phenoxyphenylethyl (meth)acrylate Acrylate, para-phenoxyphenylethyl (meth)acrylate, ortho-phenoxy Diphenylpropyl (meth)acrylate, meta-phenoxyphenylpropyl (meth)acrylate Acrylate, para-phenoxyphenylpropyl (meth)acrylate, ortho-phenoxyphenyl Phenoxyphenylbutyl (meth)acrylate, meta-phenoxyphenylbutyl (meth) Acrylate, para-phenoxyphenyl butyl (meth)acrylate, ortho-phenoxyphenyl Phenoxyphenylpentyl (meth)acrylate, meta-phenoxyphenylpentyl (meth)acrylate ) acrylate, para-phenoxyphenylpentyl (meth)acrylate, ortho- Phenoxyphenylhexyl (meth)acrylate, meta-phenoxyphenylhexyl ( phenoxyphenyl hexyl (meth)acrylate, para-phenoxyphenyl hexyl (meth)acrylate, etc. Phenoxyphenyl alkyl (meth)acrylate, ortho-phenoxyphenyloxymethy (meth)acrylate, meta-phenoxyphenyloxymethyl (meth)acrylate , para-phenoxyphenyloxymethyl (meth)acrylate, ortho-phenoxyphenyl Phenoxyethyl (meth)acrylate, meta-phenoxyphenyloxyethyl (meth)acrylate p-phenoxyphenyloxyethyl (meth)acrylate, ol Meta-phenoxyphenyloxypropyl (meth)acrylate, meta-phenoxyphenyl Para-phenoxyphenyloxypropyl (meth)acrylate, para-phenoxyphenyloxypropyl (meth)acrylate meth)acrylate, ortho-phenoxyphenyloxybutyl (meth)acrylate, meth Ter-phenoxyphenyloxybutyl (meth)acrylate, para-phenoxyphenyl Phenoxyphenyloxyalkyl (meth)acrylates such as oxybutyl (meth)acrylate acrylate, ortho-phenoxyphenyl methoxyethyl (meth)acrylate, meta- Phenoxyphenyl methoxyethyl (meth)acrylate, para-phenoxyphenyl meth ethoxyethyl (meth)acrylate, ortho-phenoxyphenylethoxyethyl (meth)acrylate Acrylate, meta-phenoxyphenylethoxyethyl (meth)acrylate, para- Phenoxyphenylalkoxy such as phenoxyphenylethoxyethyl (meth)acrylate Among these, phenoxyphenyl Alkyl (meth)acrylates are preferred from the viewpoint of solubility and moldability, and phenoxyethanol is particularly preferred. Phenoxyphenylmethyl (meth)acrylate and phenoxyphenylethyl (meth)acrylate From the viewpoint of a high refractive index, phenoxyphenylmethyl (meth)acrylate is more preferable. Among the positional isomers, the meta position is more preferable. Furthermore, in consideration of reactivity, Acrylates are preferred over methacrylates. These compounds may be used alone. However, two or more types may be used in combination. In consideration of moldability and yellowing at high temperatures, phenoxyethanol is preferred. A (meth)acrylate having a diphenyl structure is more preferred.

[0015] In addition, the curable composition for forming the cured product may contain other active energy ray curable compounds other than those mentioned above. For example, compounds containing aromatic rings (metal compounds) can be used in order to increase the refractive index. ) acrylates, benzyl (meth)acrylate, phenyl (meth)acrylate , phenoxyalkyl (meth)acrylate, etc. By doing so, it is possible to obtain a viscosity suitable for molding. From this viewpoint, benzyl methacrylate and phenyl methacrylate are more preferred.

[0016] Furthermore, the curable composition for forming the cured product may contain a fluorene structure, a vinyl group, or a vinyl group from the viewpoint of moldability. Monofunctional acrylates excluding (meth)acrylates having a phenyl or phenoxyphenyl structure (Meth)acrylate, bifunctional (meth)acrylate, trifunctional or higher multifunctional (meth)acrylate A mixture of one or more types of related resins, commercially available as a curable resin material, or In addition to these, other components may be further added within the scope that does not impair the object of this embodiment. When considering the strength of the cured product and the ability to cure at high temperatures, A high glass transition temperature is desirable to make materials less likely to deform, but It is preferable that the compound contains a polyfunctional (meth)acrylate having a functionality of 1 or more.

[0017] Monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, Acrylate, butyl (meth)acrylate, propyl (meth)acrylate, n-butyl butyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, Uryl (meth)acrylate, Stearyl (meth)acrylate, Morpholyl (meth)acrylate Acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl ( (meth)acrylate, 4-hydroxybutyl (meth)acrylate, glycidyl (meth) Acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate (meth)acrylate, tricyclodecane (meth)acrylate, polyethylene glycol Cyclohexyl (meth)acrylate, tetrahydrofurfuryl dicyclopentanyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl Allyl (meth)acrylate, isobornyl (meth)acrylate, allyl (meth)acrylate acrylate, 2-ethoxyethyl (meth)acrylate, adamantyl (meth)acrylate, (Meth)acrylic acid and the like.

[0018] The difunctional polyfunctional (meth)acrylate is not particularly limited, but examples thereof include For example, 1,4-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate Acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanedi All di(meth)acrylate, tricyclodecane dimethylol di(meth)acrylate Alkanediol di(meth)acrylates, bisphenol A ethylene oxide modified Di(meth)acrylate, bisphenol F, ethylene oxide modified di(meth)acrylate bisphenol-modified di(meth)acrylates, polyethylene glycol di(meth)acrylates, etc. acrylate, polypropylene glycol di(meth)acrylate, urethane di(meth)acrylate di(meth)acrylate, epoxy di(meth)acrylate, etc.

[0019] The trifunctional or higher polyfunctional (meth)acrylate is not particularly limited, but may be: For example, dipentaerythritol hexa(meth)acrylate, pentaerythritol tetraacetate Pentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, ditrimethicone Trimethylolpropane tetra(meth)acrylate, trimethylolpropane tri(meth)acrylate acrylate, ethylene oxide modified dipentaerythritol hexa(meth)acrylate , ethylene oxide modified pentaerythritol tetra(meth)acrylate, ethylene Ethylene oxide such as oxide-modified pentaerythritol tri(meth)acrylate Modified (meth)acrylate, ethylene oxide isocyanurate modified tri(meth)acrylate isocyanurate, ε-caprolactone-modified tris(acryloxyethyl) isocyanurate, etc. Cyanuric acid modified tri(meth)acrylate, pentaerythritol triacrylate hexyl Methylene diisocyanate urethane prepolymer, pentaerythritol triacrylate Toluene diisocyanate urethane prepolymer, dipentaerythritol pentaerythritol Urethane (meth) such as acrylate hexamethylene diisocyanate urethane prepolymer Among these, those that can increase the glass transition temperature of the cured product are In terms of curability, strength, and reflow resistance, trimethylolpropane tri(meth)acrylate Dipentaerythritol hexa(meth)acrylate, pentaerythritol tetra(meth)acrylate pentaerythritol tri(meth)acrylate and pentaerythritol tri(meth)acrylate are more preferred. stomach.

[0020] In addition, the curable composition for forming the cured product may contain an active energy group other than (meth)acrylate. It is also possible to use ray-curable compounds, such as styrene and vinyl halides. vinyl compounds such as vinyl acetate, vinylidene halides, 1,3-butadiene, isoprene Furthermore, diene compounds such as ethylenediamine and chloroprene are also included in the high-temperature process. To prevent discoloration, it is preferable that the material does not contain sulfur or nitrogen elements, especially sulfur. It must not contain siloxane compounds or inorganic components in order to ensure uniformity of the components when made into a compound. If the components are not uniform, visibility will decrease and the film will become brittle.

[0021] The curable composition that forms the cured product preferably further contains a polymerization initiator. The inclusion of an initiator accelerates the curing reaction of the curable composition, resulting in a strong cured product. As the polymerization initiator, a conventionally known material can be used, and a thermal polymerization initiator (a polymerization initiator that is activated by heating) can be used. Therefore, compounds with active groups that generate radicals or cations, etc., and photopolymerization initiators (active compounds that have active groups that generate radicals when irradiated with energy rays, etc. The curing time can be shortened and the reaction rate of carbon-carbon double bonds can be controlled highly. From this viewpoint, a photopolymerization initiator is preferred.

[0022] Thermal polymerization initiators include 2,2'-azobisbutyronitrile and 2,2'-azobis(2,4- dimethylvaleronitrile), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) azo compounds such as benzoyl peroxide and di-t-butyl peroxide , lauroyl peroxide, t-butyl peroxy 2-ethylhexanoate, t- Hexylperoxy 2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy Peroxides such as 2-ethylhexanoic acid hydroxyl, t-hexyl hydroperoxide Thermal radical polymerization initiators such as benzenesulfonate esters and alkylsulfonium salts Thermal cationic polymerization initiators, inorganic compounds such as hydrogen peroxide, sodium persulfate, and ammonium persulfate Peroxides, etc. Among these, thermal radical polymerization initiators are preferred.

[0023] Examples of the photopolymerization initiator include a photoradical polymerization initiator, a photocationic polymerization initiator, a photocatalytic polymerization initiator, and a photopolymerization initiator. Among these, photo-radical polymerization initiators are preferred. The dicarboxylic polymerization initiator is 2-hydroxy-2-methyl-1-phenylpropane-1- ion, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl) benzyl]phenyl}-2-methylpropan-1-one, 2-methyl-[4-(methylthio) (O)phenyl]-2-morpholino-1-propanone, oligo{2-hydroxy-2-methyl Benzyl dimethyl ether}, 1-[4-(1-methylvinyl)phenyl]propanone Alkyl alcohol, 1-hydroxycyclohexyl phenyl ketone, benzoin methyl ether, etc. Benzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone Methylbenzophenone, methyl orthobenzoylbenzoate, 4-phenylbenzophenone Benzophenone-type compounds such as anthraquinone; t-butylanthraquinone, 2-ethylanthraquinone anthraquinone-type compounds such as 2-benzyl-2-dimethylamino-1-(4-morpholine); (trimethylphenyl)-butanone-1, diethylthioxanthone, isopropylthioxanthone Thioxanthone-type compounds such as 2,4,6-trimethylbenzoyldiphenylphosphine Oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentyl Phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine Acylphosphine oxide compounds such as phenylglyoxylic acid phenyl glyoxylate type compounds such as methyl ester of phenyl glyoxylate. Among these, alkylphenone compounds are preferred because they can prevent the cured product from becoming discolored. Furthermore, from the viewpoint of foreign matter, it is more preferable that the molecular weight of the generated radical is 95 or less, It is more preferable that the ratio is 70 or less. Therefore, it is preferable that the compound has good compatibility with other compounds in the curable composition. It is preferable that the compound does not contain phosphorus, such as phosphorus oxide. From this point of view, it is preferable that the polymerization initiator does not contain nitrogen element or sulfur element, particularly sulfur element. That is, 2-hydroxy-2-methyl-1-phenylpropan-1-one and 2-hydroxy hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzyl]phenyl The most preferred polymerization initiator is 2-methyl-2-propan-1-one. They may be used alone or in combination of two or more.

[0024] Furthermore, the curable composition that forms the cured product contains a compound that prevents yellowing during high-temperature processes such as reflow. For this reason, it is also a preferred embodiment to contain an antioxidant.

[0025] Examples of antioxidants include 2,6-di-t-butylphenol, 2,6-di-t- Butyl-p-cresol, 6,6'-di-t-butyl-4,4'-butylidene di-meta- Cresol, 3,9-bis{2-[3-(3-t-butyl-4-hydroxy-5-methyl (phenyl)propionyl)-1,1-dimethylethyl}-2,4,8,10-tetramethyl Laoxaspiro[5.5]undecane, ethylenebis(oxyethylene)bis-(3-( 5-t-butyl-4-hydroxy-meta-tolyl)propionate), hexamethylenediamine Thiopropylsilane (3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate), Diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propione N-N'-hexane-1,6-diylbis(3-(3,5-di-t-butyl-4 -hydroxyphenylpropionamide), 1,3,5-tris(3,5-di-t-butyl) 1H,3H,(4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H, 5H)-trione, 4,4',4''-(1-methylpropanyl-3-ylidine)tris (6-t-butyl-meta-cresol), 1,3,5-tris(3,5-di-t-butyl) -4-hydroxyphenylmethyl)-2,4,6-trimethylbenzene, 3,3',3 '',5,5',5''-Hexa-t-butyl-α,α',α''-(mesitylene-2, 4,6-triyl)tri-para-cresol, tetrakis-[methylene-3-(3',5 phenols such as '-di-t-butyl-4'-hydroxyphenyl)propionate]methane Antioxidants: Triphenyl phosphite, tris-isodecyl phosphite, tris-isodecyl phosphite phosphates such as tridecyl phosphite and tris(2,4-di-t-butylphenyl) phosphite Antioxidants: Dilauryl-3,3'-thiodipropionate, Ditridecyl-3,3 '-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearate aryl-3,3'-thiodipropionate, pentaerythritol tetrakis(β-lauric acid) Among these, sulfur-based antioxidants such as thiopropionate are also useful. From the viewpoint of solubility in the composition, phenol-based antioxidants and sulfur-based antioxidants are preferred. From the viewpoint of preventing yellowing of the cured product, phenol-based antioxidants are more preferred.

[0026] Among phenolic antioxidants, this product is effective in preventing yellowing during high-temperature processes such as reflow, and in preventing high In order to prevent the generation of foreign matter at high temperatures, an acid having two or more hindered phenol structures in the molecule is used. Antioxidants are preferred, and compounds having three or more hindered phenol structures in the molecule are preferred. More preferably, the number is 4 or more. That is, tetrakis-[methylene -3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]me Tan is most preferred.

[0027] In addition, from the viewpoint of preventing the generation of foreign matter, the molecular weight is preferably 540 or more, more preferably 600 It is preferably in the range of 700 or more, more preferably 700 or more, and most preferably 800 or more. Regarding this point, we have considered the prevention of foreign matter generation due to the evaporation and decomposition of compounds and the difficulty of seeing foreign matter. It is desirable to take this into consideration, and it is preferably 60°C or higher, more preferably 80°C or higher, and even more preferably The upper limit is preferably 250°C or less, and more preferably 100°C or more. The curing temperature is preferably 200°C or lower, more preferably 150°C or lower. From this viewpoint, it is preferable that these antioxidants do not contain nitrogen atoms or sulfur atoms. They may be used singly or in combination of two or more.

[0028] As a curable composition for forming a cured product, the above-mentioned The composition may contain other components in addition to the above-mentioned compounds. Examples of the other components include a curing aid, Various resins, rubber, particles, antistatic agents, plasticizers, ultraviolet absorbers, infrared absorbers, light stabilizers, Leveling agents, antifoaming agents, thixotropic agents, polymerization inhibitors, release agents, fillers, fluorescent materials, pigments, dyes, etc. Various additives can be mentioned.

[0029] The total mass of all structural units constituting the curable composition is The proportion of acrylate is preferably 15 to 95% by mass, more preferably 25 to 85% by mass. %, and more preferably in the range of 40 to 75 mass %. It can be made higher.

[0030] biphenyl or phenoxyethanol relative to the total mass of all structural units constituting the curable composition The proportion of the (meth)acrylate having a phenyl structure is preferably 80% by mass or less, more preferably The range is preferably 50% by mass or less, and more preferably 40% by mass or less. The range is preferably 5% by mass or more, and more preferably 8% by mass or more. By doing so, the refractive index can be increased, and the (meth)acrylate having a fluorene structure It also has better compatibility with

[0031] The amount of trifunctional or higher polyfunctional (meth)acrylates relative to the total mass of all structural units constituting the curable composition is Acrylate (having a fluorene structure, a biphenyl structure or a phenoxyphenyl structure) The proportion of (meth)acrylates) is preferably 50% by mass or less, more preferably 40% by mass or less. The range is preferably 5% by mass or less, more preferably 35% by mass or less. The range is preferably 8% by mass or more, and more preferably 8% by mass or more. While maintaining the same properties, it also increases the glass transition temperature, improves moldability, and improves the strength of the cured product. It is possible to do this.

[0032] The ratio of the polymerization initiator to the total mass of all the structural units constituting the curable composition is preferably is 10% by mass or less, more preferably 8% by mass or less, even more preferably 5% by mass or less, particularly The range is preferably 5% by mass or less, and most preferably 4% by mass or less. At least 0.2% by mass, more preferably at least 0.3% by mass, and even more preferably at least 1% by mass. The content is most preferably in the range of 2.5% by mass or more. This improves the curability of the product, resulting in a cured product with high strength, high transparency, and little foreign matter.

[0033] The ratio of the antioxidant to the total mass of all the constituent units constituting the curable composition is preferably is 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less The lower limit is preferably 0.01% by mass or more, and more preferably 0.1% by mass or more. By setting the range above, yellowing due to high-temperature processes such as reflow can be prevented. becomes higher.

[0034] <Cured product> The cured product is obtained by curing the above-mentioned curable composition. The cured product can be obtained by the following method: For example, the curable composition is formed into a predetermined shape, and then cured to form a hardened product having the predetermined shape. In this way, a cured product having a predetermined shape can be obtained. Examples of such methods include a coating method in which a curable composition is applied to a film substrate, a potting method, and the like. molding method, casting molding method, printing molding method, liquid resin injection molding method In addition, the curable composition can be cured by the LIM method, transfer molding method, etc. The polymerization method may be photopolymerization, thermal polymerization, or the like, depending on the type of polymerization initiator contained in the curable composition. Either polymerization or redox polymerization can be used.

[0035] When a curable composition is cured by photopolymerization to obtain a cured product, the wavelength of light irradiated onto the curable composition Although there are no particular limitations on the type of irradiation, it is preferable to irradiate with ultraviolet light having a wavelength of 200 to 400 nm. Specific examples of ultraviolet light sources include ultra-high pressure mercury lamps, high pressure mercury lamps, and metal halide lamps. Examples include lamps, high-power metal halide lamps, and UV-LED lamps. For example, when ultraviolet light is used, the cumulative light intensity is 100 mJ / cm 2 More than 10000m J / cm 2 It is preferable to irradiate at a dose of 500 mJ / cm or less. 2 More than 8000m J / cm 2 The more preferable illuminance is 5 mW / cm or less.2 More than 1000mW / cm 2 Less than 10 mW / cm is preferable. 2 More than 500mW / cm 2 The following is more preferable: , 20mW / cm 2 More than 300mW / cm 2 The following is even more preferred:

[0036] After the curable composition has been photopolymerized, it is preferable to further carry out after-curing. This makes it possible to reduce the amount of unreacted (meth)acryloyl groups remaining in the cured product. This allows for increased strength of the cured product. Preferably, the temperature is 160°C for 0.1 to 24 hours, and more preferably, the temperature is 80 to 130°C for 0.2 to 10 hours. It's nice.

[0037] When the curable composition is cured by thermal polymerization to obtain a cured product, the curing conditions are not particularly limited. The curing temperature is preferably 40 to 200°C, since this makes it easier to obtain a cured product with reduced coloration. , 60 to 150°C is more preferable. In LIM and transfer molding, a curable composition is placed in a preheated mold. The curing time (heating time) when injecting and molding varies depending on the curing temperature. For example, When the curing temperature is 100°C, the time is preferably 1 to 180 seconds, more preferably 1 to 120 seconds, and On the other hand, in the case of the casting molding method, the hardening composition is placed in a mold at room temperature. The curing time when the composition is heated after injection varies depending on the curing temperature. For example, When the temperature is 70°C, the heating time is preferably 5 minutes to 5 hours, and more preferably 10 minutes to 3 hours. After the curable composition is thermally polymerized, it is preferable to further carry out after-curing. The post-cure conditions are preferably 50 to 150°C for 0.1 to 10 hours, and 70 to 1 More preferably, the temperature is 30°C for 0.2 to 5 hours.

[0038] When a curable composition is cured by redox polymerization to obtain a cured product, the curable composition is By using an initiator, it can be cured at room temperature of 5℃ to 40℃. The amount of remaining unreacted (meth)acryloyl groups can be reduced, and the strength of the cured product can be improved. The curing temperature is preferably 15 to 40°C since it can be increased as much as possible. The curable composition is less likely to gel and can be handled stably. Therefore, a reducing agent is added to the curable composition in advance. Preferably, the curing is carried out by dissolving the compound in a substance and then adding peroxide to the solution.

[0039] The reaction rate of the carbon-carbon double bonds in the cured product must be 88% or more. Preferably 90% or more, more preferably 91% or more, and even more preferably 92% or more The upper limit is 100%. By keeping it within this range, high-speed processing such as reflow processing can be performed. Reduction of foreign matter generation due to reduction of volatile matter during the temperature process, and reduction of foreign matter generation after high temperature and high humidity treatment This makes it possible to reduce cracks and to produce a cured product with better visibility. The reaction rate of the carbon-carbon double bond was determined by the method shown in the following formula (1): do. Carbon-carbon double bond reactivity (%) = 100 × {1 - (B / A)} (1) A: 809 cm in the infrared absorption spectrum of the curable composition before curing -1 Absorption peak Arc strength B: 809 cm in the infrared absorption spectrum of the curable composition after curing -1 Absorption peak Arc strength

[0040] The refractive index of the cured product is measured at 25°C using sodium D line (589 nm). , preferably 1.590 or more, more preferably 1.595 or more, It is more preferable that the ratio is 0.596 or more. There is no particular upper limit, but it is preferably 1. By keeping the above range, various designs are possible and the range of applications is wide. do.

[0041] The glass transition point of the cured product was determined by measuring the dynamic viscoelasticity and loss of the cured product using a dynamic viscoelasticity measuring device. The loss tangent is measured, and the temperature at which the loss tangent (tanδ) shows the maximum value is preferably 100°C or higher. Preferably, the temperature is 110°C or higher, more preferably 110°C or higher, and even more preferably 120°C or higher. It is preferable that the temperature is 130°C or higher. There is no upper limit, but it is preferably 250°C or lower. By setting the content within the above range, the shape of the cured product is stable and less likely to deform even at high temperatures. This improves the reliability of the material and broadens the range of applications it can be used in. can.

[0042] <Lens> The lens is made of the above-mentioned cured product. This lens is used in, for example, mobile phones, notebooks, etc. Electronic devices such as computers, tablets, digital cameras, and cameras installed in automobiles, etc. The lens can be a molded product made solely from the cured product of the present invention. However, a transparent substrate such as a flat glass or a glass wafer and a molded film on this transparent substrate are The lens may also be a hybrid lens made of the above-mentioned cured product. [Example]

[0043] The present invention will be described in more detail below with reference to examples, but the present invention will not be limited to the gist of the present invention. However, the present invention is not limited to the following examples. The measurement and evaluation methods used in the present invention are as follows.

[0044] (1) Melting point In simultaneous thermogravimetry and differential thermal measurements, the temperature was raised from 30°C at a rate of 10°C / min in an air atmosphere. When heated to 330℃, the temperature (℃) is plotted on the horizontal axis and the differential thermal analysis value (μV) on the vertical axis. The temperature at the minimum value was read.

[0045] (2) Reaction rate of carbon-carbon double bonds The infrared absorption spectra of the curable composition before and after curing (cured product, UV-irradiated side) 809cm -1 The absorption peak intensity was measured by ATR-IR (PerkinElmer) FT-IR Spectrometer Spectrum 100 and Unive Measurements were taken using a RS ATR Sampling Accessory. The reaction rate of the carbon-carbon double bond was calculated from the measured peak intensity using the following formula (1). Carbon-carbon double bond reactivity (%) = 100 × {1 - (B / A)} (1) A: 809 cm in the infrared absorption spectrum of the curable composition before curing -1 Absorption peak Arc strength B: 809 cm in the infrared absorption spectrum of the curable composition after curing -1 Absorption peak Arc strength The peak intensity was calculated by plotting a graph with wave number on the horizontal axis and peak intensity on the vertical axis. When the baseline of the peak is taken as the wave number of the tangent to the base of the peak, it is 809 cm -1 in The peak intensity was read and the 809 cm -1 Difference from the peak intensity at were calculated as A and B, respectively. Specifically, for this material, the -1 and 821 cm -1 The wave number of the line connecting these points is 809 cm. -1 The peak intensity at 809cm each -1 The difference between the peak intensity at and at was designated as A and B.

[0046] (3) Refractive index The curable composition was cured to prepare a cured product having a thickness of 1 mm. The fluorine D line (589 nm, 25°C) was measured using a multi-wavelength Abbe refractometer (manufactured by Atago Co., Ltd., "DR The measurement was carried out using methylene iodide (Corporation (manufactured by Atago) was used.

[0047] (4) Glass transition temperature The curable composition was cured to prepare a cured product having a thickness of 1 mm. The temperature at which the loss tangent (tanδ) reaches its maximum value is the glass transition point of the cured product. The measurements were carried out using a dynamic viscoelasticity measuring device (TA Instruments Japan Co., Ltd.). The measurement conditions were tension mode and measurement frequency 10 Hz. did.

[0048] (5) Evaluation of the number of foreign objects The curable composition was cured to prepare a cured product (lens) having a thickness of 1 mm. The side is covered with a silicone rubber sheet (Azwan Corporation silicone rubber sheet 300mm x 30 The sample was sandwiched between two pieces of glass (0mm x 1t) and fixed on both sides with glass plates. The composition is glass plate / silicone rubber sheet / hardened product / silicone rubber sheet / glass plate. The test was carried out at 240°C for 10 minutes, and then further treated in a 40°C, 90% RH environment for one week. Then, a surface shape measurement system (Hitachi High-Tech Science Corporation, "Vert Scan " (registered trademark) VS1330) was used to coat the surface of a glass plate placed opposite the cured product. The observation conditions were: camera standard: 1 / 3, zoom lens: 1x, telescope: 1x, light source: 530white, measurement mode: Wave (piezo), objective lens: 20XDI. To evaluate the number of foreign objects, an area of ​​236.873 μm × 177.60 μm on the surface of the glass plate was For the area, use the bearing function and set both the peak height threshold and valley height threshold to 0.0. The particle size was set to 10 μm, binarized, and calculated using the particle analysis function under the following analysis conditions. (particle analysis) Curvature correction: No ·Analysis: Sudden analysis -Binarization threshold: 0.010μm Particle molding: No Target determination Height base: curved Height: Upper limit 100000nm, lower limit 0nm Maximum diameter: Upper limit 1000 μm, lower limit 0 μm Volume: Lower limit 0.0μm3 Aspect Ratio: Lower Limit 0.0 It is preferable to have a small number of foreign objects, and the best state is when there are no foreign objects. If the number is 0 or less, it is considered to be in good condition.

[0049] (Production of curable composition) The materials shown in Table 1 were mixed in the mass ratios shown in Table 1. The materials in Table 1 are as follows: do. (Meth)acrylate having a fluorene structure: A In the above formula (1), R 1 , R 2 , R 3 , R 4 is a hydrogen atom, and m and n are 1. thing. (Meth)acrylate with a phenoxyphenyl structure: B Meta-phenoxyphenyl methyl acrylate Trifunctional or higher multifunctional (meth)acrylates: Trimethylolpropane trimethacrylate (C-1) Dipentaerythritol hexaacrylate (C-2) Benzyl methacrylate: D Polymerization initiator: 2-Hydroxy-2-methyl-1-phenyl-propan-1-one (E-1) 2-Hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)benzoyl] {Dimethyl}phenyl}-2-methylpropan-1-one (E-2) Phosphine oxide polymerization initiator: (F) 2,4,6-trimethylbenzoyldiphenylphosphine oxide Antioxidant with four hindered phenol structures in the molecule: G Tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl] (Nyl)propionate]methane (Melting point 116°C)

[0050] [Table 1]

[0051] [Example 1] The curable composition shown in Table 1 was applied to a silicone rubber sheet having a thickness of 1 mm and an inner diameter of 30 mm. The mixture was poured into a mold made of glass plates, and then sealed by stacking glass plates on top. On the glass surface, the illuminance is 60mW and the cumulative light amount is 2000mJ / cm 2 UV radiation from high pressure mercury The cured product (lens) was then irradiated with ray and 30 mm in diameter and 1 mm in thickness. The cured product was peeled off from the plate and then heat treated at 160°C for 1 hour. The cured product thus obtained was measured or evaluated for the items shown in Table 2 using the methods described above. As shown in Table 2, the refractive index and glass transition point are high, and the reaction rate of the carbon-carbon double bond is also high. The results were good, with little foreign matter generation.

[0052] [Examples 2 to 4] The same procedure as in Example 1 was repeated except that the composition of the curable composition was changed as shown in Table 1. The properties of the cured product are shown in Table 2 below.

[0053] [Comparative Example 1] The same procedure as in Example 1 was repeated except that the composition of the curable composition was changed as shown in Table 1. The properties of the obtained cured product are shown in Table 2 below. -The reactivity of carbon double bonds was low, resulting in the generation of foreign matter.

[0054] [Table 2]

Claims

1. A cured product comprising a curable composition containing a (meth)acrylate having a fluorene structure, a (meth)acrylate having a phenoxyphenyl structure, and a trifunctional or higher polyfunctional (meth)acrylate (excluding the (meth)acrylate having the fluorene structure, biphenyl structure, or phenoxyphenyl structure), wherein the reactivity of the carbon-carbon double bond represented by the following formula (1) is 88% or more: The (meth)acrylate having a fluorene structure is a compound represented by the following formula (2): A cured product in which, relative to the total mass of all structural units constituting the curable composition, the proportion of the (meth)acrylate having a fluorene structure is 25 to 85 mass%, the proportion of the (meth)acrylate having a phenoxyphenyl structure is 5 to 80 mass%, and the proportion of the trifunctional or higher polyfunctional (meth)acrylate is 5 to 50 mass%. Carbon-carbon double bond reactivity (%)=100×{1−(B / A)} (1) A: 809 cm in the infrared absorption spectrum of the curable composition before curing －１ Absorption peak intensity B: 809 cm in the infrared absorption spectrum of the curable composition after curing －１ Absorption peak intensity 【Chemistry 1】 In formula (2), R 1 , R 2 , R 3 and R 4 each independently represent a hydrogen atom or a methyl group, m represents an integer of 0 to 5, and n represents an integer of 0 to 5.

2. The cured product according to claim 1 , wherein the curable composition contains a (meth)acrylate having a biphenyl structure.

3. The cured product according to claim 1 or 2, wherein the curable composition contains a polymerization initiator.

4. The cured product according to any one of claims 1 to 3, wherein the curable composition contains an antioxidant.

5. The cured product according to any one of claims 1 to 4, wherein the proportion of the polymerization initiator is 10 mass% or less relative to the total mass of all structural units constituting the curable composition.

6. The cured product according to any one of claims 1 to 5, wherein the proportion of the antioxidant is 10 mass% or less relative to the total mass of all structural units constituting the curable composition.

7. A lens comprising the cured product according to claim 6.

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