JPH03199218A - Curable composition and plastic lens comprising cured product of same composition - Google Patents

Abstract

PURPOSE:To obtain the title readily moldable composition suitable as plastic lens, having high refractive index, excellent heat resistance, impact resistance, etc., by blending a specific diallyl phthalate-based oligomer with vinyl-based monomer and radical polymerization initiator. CONSTITUTION:(A) >=10wt.% diallyl phthalate-based oligomer shown by the formula (R is 2-20C hydrocarbon; Ar is phenylene; n is 1-100) and having 20-100 degree of unsaturation is blended with (B) a vinyl-based monomer such as methyl acrylate copolymerizable with the component A and (C) preferably 0.001-20mol% radical polymerization initiator such as 2,2'-azobisisobutylonitrile to give the objective composition.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a curable composition that is easy to mold and provides a cured product with a relatively high refractive index and excellent heat resistance and impact resistance, and the cured composition. The present invention relates to a plastic lens made of a cured product of a plastic composition.

[Prior Art] As a resin for optical materials, such as a resin for vision correction lenses, polydiethylene glycol bisallyl carbonate (CR-39) developed by PPG Company (USA) in 1942 is used.
) is surface abrasive and easy to form.

It has been used as a mainstream resin from the viewpoint of dyeability and balance of other physical properties.

However, CR-39 has a low refractive index of 1.498, and has the drawback that the lens cannot be made thinner when strong correction is required.

In order to solve this problem, various resins for high refractive lenses have been proposed, and some of them have been put into practical use. especially.

After the publication of JP-A-57-54901, the number of patent applications for high refractive index resins increased rapidly, indicating that chemical-related material manufacturers are actively engaged in research and discovery.

For example, examples of tetrabromophenyl methacrylate/divinylbenzene threads in JP-A No. 61-73101, examples of halogenated bisphenol S dimethacrylate threads in JP-A-62-73201, and JP-A-57-54901
Examples of the tetrabromobisphenol A dimethacrylate/styrene system disclosed in JP-A-60-103302 and tetrabromobisphenol A diallyl carbonate system disclosed in JP-A-60-103302 have been proposed, but the resins of these systems contain It has problems such as decreased weather resistance and increased specific gravity due to halogen, and in systems where vinyl groups and methacryloyl groups coexist, copolymerizability of II+18 is difficult and uneven polymerization and whitening may occur. Generally, they have the disadvantage of having a low degree of freedom in formulation.

Furthermore, in the example of benzyl fumarate/sialyl isophthalate disclosed in JP-A No. 61-34007, a non-halogen medium to high refractive index lens has been proposed, but the balance between heat resistance and impact resistance is insufficient. In terms of points, it is 6 inferior to Cr (-39).

Fourth, JP-A-60-199016, JP-A-60-1990-
In the example of the system using thiourethane disclosed in Publication No. 217229, although the impact resistance is improved, the drawbacks are that the heat resistance is low, reaction control and demolding are extremely difficult, and the surface precision of the cured product is low. have.

[Problem to be Solved by the Invention J] The present invention overcomes the drawbacks of the conventional optical material mP4 resin, has a relatively high refractive index, and has excellent physical properties such as tFt impact resistance, heat resistance, and low specific gravity. It is an object of the present invention to provide a curable composition that is excellent in quality, causes few troubles in production, and can be molded into a cured product extremely easily, and a plastic lens made of a cured product of the curable composition.

[Means for Solving the Problems] The present invention provides a novel curable composition that can achieve the above objects, and a plastic lens made of a cured product of the curable composition. That is, the present invention is based on the general formula (I
), and C112=CIIC1+20 (CO
ArCOOROLl 1lCOArCOOC+IaCH=
CHt...(I) (wherein, R is a divalent carbon having 2 to 20 carbon atoms (in the formula, R is 1.2+, 1.3- or 1.4-)22 Shin group, n represents a number from 1 to 100, provided that Ar is 1.4-
At least 10% by weight of a diallyl phthalate oligomer having a degree of unsaturation expressed as an iodine value measured by the Wijs method from 20 to 100 (excluding cases where the oligomer contains only phenylene groups) is copolymerizable with the oligomer. This curable composition is characterized by comprising a vinyl monomer and a radical polymerization initiator. Further, the present invention provides that some or all of the divalent hydrocarbon residues having 2 to 20 carbon atoms represented by R in the diallyl phthalate oligomer of the general formula (I) have 3 or more carbon atoms, and 3 hydroxyl groups. The present invention is a curable composition that is an oligomer substituted with at least one polyol residue, and a plastic lens comprising a cured product of the curable composition.

The oligomer represented by the general formula (1) can be synthesized in several ways, such as a method in which diallyl phthalates and a diol are reacted in the presence of a transesterification catalyst while distilling off allyl alcohol, or a method in which dimethyl phthalate is reacted with a diol while distilling off allyl alcohol. There is a method in which a or diethyl phthalates are reacted with diol and allyl alcohol in the presence of a transesterification catalyst while distilling off methanol or ethanol.

Furthermore, some or all of R represented by the general formula ([) is 3
In the case of a polyol of 1i1 [i or more, a polyol corresponding to diallyl phthalate, diallyl isophthalate and diallyl terephthalate alone or in a mixture is added to the diol or mixed with the diol, or - corresponding to the oligomer of formula (I) Esthetic polyol
It can be obtained by heating in the presence of a carbon exchange catalyst.

Of course, it may be synthesized by other methods.

In this case, when Ar in the MQ formula (H is a 1.2-n-substituted phenylene group (phthalate)), the price is generally low, and the cured product has excellent mechanical properties, so Although it is suitable for use as a curable composition, it is not suitable for use as a particularly high-grade optical material (due to the Y direction).

The cured product obtained from the :S conductor of 1.3-substituted phenylene group (isophthalate) has good monochromatic aberration and is suitable as a high-grade optical material and a plastic lens.

Cured products obtained from derivatives of 1.4-substituted phenylene groups (terephthalate) have excellent heat resistance and excellent optical properties, and are therefore preferred as optical materials used at high temperatures.

In this case, the diol to be reacted is 0.99 mol or less per 1 mol of phenylene ant, 0.5 mol or less for trivalent polyol, preferably 0.33 mol or less, and 0.33 mol or less for tetravalent polyol. may be used in an amount of 0.25 mol or less.

Generally, if the diol content approaches 1 mole, mechanical properties will improve, but the viscosity of the oligomer will increase, so it must be selected appropriately depending on the purpose. Also, polyols with a valence of 3 or higher improve mechanical properties such as sprouting strength, but they also increase viscosity and the risk of gelation. L will is necessary.

Such diols having 2 to 20 carbon atoms include ethyl glycol, 1,2-propylene glycol,
1.4-butanediol, 1゜6-hexanediol,
Examples include diols containing a fatty or aromatic layer such as 1.4-cyclohexane dimetatool, 1.3-butanediol, neopentyl glycol, 1.3-cyclohexanediol, p-xylene glycol, and styrene glycol. In this case, considering solubility with other polymerizable monomers, diols with side chains are preferable to linear α,ω-diols, and 1,2-propylene glycol , 1゜3-butanediol, neopentyl glycol, 2.3-butanediol, 1.4-
pencundiol, 1,3-bentanediol, 1,2
-bentanediol, 2,3-bentanediol.

2.4-bentanediol, 1.5-hexanediol, 1.4-hexanediol, 1.3-hegysandiol, 1.2-hexanediol, 23-hexanediol, 2.4-hexanediol, 2.5 -hexanediol, 3,4-hexanediol, etc.

Examples of polyols having 3 or more carbon atoms and 3 or more hydroxyl groups include aliphatic trihydric alcohols such as glycerin and trimethylolpropane; and aliphatic tetrahydric or higher alcohols such as pentaerythritol and sorbitol. 6 Generally, when a glycol has a long carbon chain, its impact resistance tends to improve, and when it has a short carbon chain, its refractive index tends to increase.

If the unsaturation degree of the diallylphthalate oligomer thus obtained is lower than 20 as determined by the Wijs method, it will become impossible to cure or it will take a very long time to cure. It will take a sunny day. On the contrary, 1
If it exceeds 00, the impact resistance will be poor, so it is not a critical Rffi, but for general use, this range is a well-balanced range and can be widely used.

- A diallyl phthalate oligomer having the structure of the formula (H) or a part of the divalent hydrocarbon residues represented by R in the structural formula are converted into trivalent hydrocarbon residues derived from polyols with a valence of 3 or more The substituted oligomer has the property of being well mixed with many organic compounds, and has extremely high impact strength and heat resistance when cured alone.

However, the resistance of the cured product obtained by curing the composition by mixing this diallyl phthalate oligomer with other vinyl monomers that can be copolymerized with this oligomer at a blending ratio depending on the intended use can be improved. It is possible to improve impact resistance and heat resistance.

The amount of diallyl phthalate oligomer used to achieve the purpose of the present invention is 10 to 901R; i%,
Preferably it is in the range of 20 to 90% by weight. The amount of diallyl phthalate oligomer used is l Q q 5';%
If the amount is less than 10%, the resulting cured product will have a sufficient effect on either impact resistance or heat resistance.

A vinyl monomer capable of copolymerizing with the oligomer that can be used with the diallyl phthalate-based gober represented by Funato (1) (it may be monofunctional or polyfunctional, and is compatible with the oligomer). There is no particular restriction as long as it is soluble.6 In addition, copolymerization ability 1 (vinyl monomers can be used in combination of two or more types, and there is no restriction on the mixing ratio, and any ratio can be used. can be selected.

Examples of such vinyl monomers include unsaturated fatty acid esters, aromatic vinyl compounds, unsaturated fatty acids and their derivatives, unsaturated dibasic acids and their derivatives, and vinyl cyanide compounds such as (meth)acrylonitrile. Can be mentioned.

Examples of unsaturated fatty acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, dodecyl (meth)acrylate, and octadecyl (meth)acrylate. -1-, cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, (iso)bornyl (meth)
Acrylate, alkyl (meth)acrylate such as adamantyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, l-naphthyl (meth)acrylate, fluorophenyl (meth)acrylate, chlorophenyl (meth)acrylate, bromophenyl ( Acrylic acid 77 compound esters such as meth)acrylate, tribromophenyl(meth)acrylate, methoxyphenyl(meth)acrylate, cyanophenyl(meth)acrylate, biphenyl(meth)acrylate, bromobenzyl(meth)acrylate, fluorocarbon Methyl (meth)acrylate, chloromethyl (meth)acrylate.

Haloalkyl (meth)acrylates such as bromoethyl (meth)acrylate, trichloromethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate,
In addition to (meth)acrylic acid polyethylene glycol ester, there are (meth)acrylic esters such as glycidyl (meth)acrylate and alkylamino (meth)acrylate. Also, α-fluoroacrylic acid ester.

Examples include α-substituted acrylic acid esters of a-an anoacrylic acid esters.

Examples of aromatic vinyl compounds include styrene, and:
Methylstyrene, α-ethylstyrene, α-substituted styrene exclusively for a-chlorostyrene, fluorostyrene, chlorostyrene, bromostyrene.

Examples include nuclear-substituted styrenes such as chloromethylstyrene and methoxystyrene, and diallyl phthalate.

Examples of unsaturated fatty acids and derivatives thereof include (meth)acrylamide, N,N-dimethyl(meth)acrylamide,
(meth) such as N,N-diethyl(meth)acrylamide
Examples include acrylamides and (meth)acrylic acid.

Unsaturated dibasic acids and their derivatives include N-methylmaleimide, N-ethylmaleimide, N-butylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-methylphenylmaleimide, N-chlorophenylmaleimide, N-carboxy Examples include N-substituted maleimides such as phenylmaleimide, maleic acid, maleic anhydride, fumaric acid, and the like.

In addition to the monofunctional vinyl monomers mentioned above, the vinyl monomers that can be copolymerized with the diallyl phthalate oligomer represented by formula (I) include:

Crosslinkable polyfunctional monomers are highly praised. For example, ethylene glycol di(meth)acrylate, dielene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tribrobylene glycol di(meth)acrylate,
meth)acrylate, 1,3-BJ-lene glycol di(
meth)acrylate, 1,4-butanediol di(meth)acrylate, 1.5-pentanediol di(meth)
acrylate, 1,6-hexanethiol di(meth)acrylate, neobentyl glycol di(meth)acrylate, hydroxybivalic acid neobentyl glycol ester di(meth)acrylate, oligoester di(
meth)acrylate, polybutadiene di(meth)acrylate, 2.2-bis(4-(meth)acryloyloxyphenyl)propane, 2.2-bis(4-(ω-(meth)acryloyloxypolyethoxy)phenyl)propane , 2.2-bis(4-(ω-(meth)acryloyloxypolyethoxy)dibromophenyl)propane, 2
．． 2-bis(4-(ω-(meth)acryloyloxypolypropoxy)phenyl)propane, bis(4-(ω(
Di(meth)acrylates such as meth)acryloyloxypolyethoxy)phenyl)methane, diallyl phthalate, diallyl isotucrate, diallyl terephthalate, diallyl carboy, -t, diethylene glycol diallyl carboy, -t, divinylbenzene, N, N' −
Difunctional crosslinking monomers such as m-phenylene bismaleimide, trimethylolethane tri(meth)acrylate, trimethylolbutylbutyl[1pantri(meth)acrylate, pentaerythritol tri(meth)acrylate, tri(meth)allyl, r Examples include trifunctional crosslinking monomers such as socyanurate, triallyl trimellitate, and diallyl chlorefdate, and tetrafunctional crosslinking monomers such as pentaerythritol tetra(meth)acrylate.

The curable composition of the present invention can be cured by radical polymerization.

The radical polymerization initiator used during curing may be any radical polymerization initiator that can generate radicals by heat, microwaves, infrared rays, or ultraviolet rays, depending on the purpose and use of the curable composition. You can select as appropriate.

Examples of radical polymerization initiators that can be used in polymerization using heat, microwaves, and infrared rays include 2.2°-azobisisobutyronitrile, 2゜2゛-azobisisovaleronitrile, and 2,2゜-azobis-2. , azo compounds such as 4-dimethylvaleronitrile, ketone peroxides such as methyl ethyl ketone peroxide, methyl isobutyl lactone peroxide, cyclohexanone peroxide, acetylacetone peroxide, isobutyryl peroxide, 2,4-dichlorobenzoyl peroxide, 0-
Methylbenzoyl peroxide, lauroyl peroxide, p-chlorobenzo, diacyl peroxide such as ruberoxide, 2.4.4-trimethylbenzoyl 2-
Hydroperoxide, diisopropyl benzene peroxide, cumene hydroperoxide, di-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, di-t-butyl peroxide, tris(L- dialkyl peroxides such as (butylperoxy) triazine, peroxyketals such as 1,1-di-savetylperoxycyclohexane, 2,2-di(L-butylperoxy)butane, and t-butylperoxyviba. Butylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, di-1-butylperoxyhexahedrotylephthalate-1-, di-t-butylperoxyazelate, t-
Butylperoxy-3,5,5-trimethylhexanoate, L-butylperoxyacetate, t-butylperoxybenzoate-1~, di-1-butylperoxytrimethyladipate exclusive alkyl peresters, diisobro Bar carbonates such as bilba oxydicarbonate, di-5ec-butylperoxydicarbonate, and t-butylbaroxyisobrobyl carbonate are Ji
I can get G.

Examples of radical polymerization initiators that can be used in polymerization using ultraviolet light include acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-jethoxyacetophenone, and 4'-isopropyl-2-hydroxy-2-methylpropiophenone. , 2-hydroxy-2-
Methylpropiophenone, 4.4゛-bis(diethylamino)benzophenone, benzophenone, methyl(0-
benzoyl)benzoate, l-phenyl 1,2-propanedione-2-(o-ethoxycarbonyl)oxime, l-phenyl-1,2-bu[Jpanedione-2-(0
-benzoin)oxy 11, benzoin, benzoin methyl needle, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzoin octyl ether, benzyl, penzyl dimethyl ketul, benzyl diethyl ketal, carbonyl compounds such as diacetyl, methyl anthraquinone, Examples include anthraquinone or thioxanthone derivatives such as chloroanthraquinone, chlorothioxanthone, 2-methylthioxanthone, and 2-isopropylthioxanthone, and sulfur compounds such as diphenyl disulfide and dithiocarbamate.

The amount of the radical polymerization initiator to be used cannot be determined unconditionally because it varies depending on the type of radical polymerization initiator, the type 4 of monomers charged, and the composition ratio, but it is usually in the range of 0001 to 20 mol% based on the monomer components. , preferably 0.0l
-10 mol% range. If the amount of radical polymerization initiator used is less than o, oot mol%, it takes a long time for one polymerization,
Further, if the amount used exceeds 20 mol %, it is not only uneconomical but also undesirable because foaming may occur during the polymerization or the molecular weight of the cured product obtained by the polymerization becomes extremely small.

The curable composition of the present invention may be directly polymerized and cured, or depending on the purpose, the viscosity may be adjusted by prepolymerizing and then polymerizing and curing. can.

Regarding the polymerization temperature and polymerization time when curing the curable composition, it cannot be unconditionally specified because it varies depending on the properties of the radical polymerization initiator used and the amount used, but it is usually 0 to 200°C for one degree of polymerization. It is preferable that the range of
The polymerization time is usually preferably in the range of 0.5 to 50 hours.

The curable composition of the present invention not only has excellent moldability, but the cured product obtained by curing the curable composition has a relatively high refractive index, and has a heat resistance and impact resistance that are 1/2 in. Due to this, the industrial division of optical materials, coating T4.11 materials, paints, adhesives, etc., especially optical products, T V'+ minutes! It is extremely useful for T.

The plastic lens of the present invention can be produced by, for example, injecting a curable composition into a lens mold made of a glass mold and a gasket, and applying heat, ultraviolet radiation, or other active energy rays. This can be easily done by drying the mold, curing it, and then removing it from the mold.

The plastic lens of the present invention is suitably used for eyeglasses, sunglasses, optical microscopes, W19 telescopes, cameras, and the like.

[Examples] Hereinafter, the present invention will be explained in more detail by giving Examples and Comparative Examples.

In addition, various physical properties of the cured products obtained in the Examples and Comparative Examples were measured by the following methods.

11) Refractive index: 20°C using an Atsube refractometer (Shimadzu Corporation Model 3L)
The refractive index was measured.

(2) Glass transition temperature (Tg) tan
By reading the peak (inflection point) of δ, the sample (
The glass transition temperature was set at a thickness of 0.1 mm).

(3) Impact resistance Using a 2D lens with a center thickness of 1.2 mm.

r: I) According to A standard, 16.3 g steel ball is 127
A falling steel ball test was performed by letting the steel ball drop naturally from a height of Cm, and those with no change were rated as ○, and those with cracks but breakage were rated as ×.

(4) Water absorption rate, using a JTS-7209 (7) test piece, calculate the rate of weight increase when a sample dried under reduced pressure at 50°C for 5 days is immersed in 100°C water for 2 JP shown based on.

(5) Moldability When a thick lens with a rim thickness of 25 mm was formed by IF, the reaction was so violent that it could not be molded or the mold release was extremely difficult.

(Production method of diallyl phthalate oligomer) (Synthesis example 1) 12 flasks equipped with distillation equipment ↓ 400 g of diallyl prephthalate (DAT), 200 g of diallyl isophthalate (DIP), 1,3-butanediol 1
09.8g (0.44 times mole) and 0.3g of dibutyltin oxide were charged and heated to 180°C under a nitrogen stream.
Allyl alcohol produced was distilled off. When about 120g of allyl alcohol was distilled out, the inside of the reaction system was
The pressure was reduced to 0 mmHg and the distillation rate of allyl alcohol was stopped. After the theoretical amount of allyl alcohol has been distilled off,
Further, it was heated for 1 fLIF. After that, the pressure was reduced to distill off unreacted DAT and DIP, and then measured by GPC.
Mn=1030. 570 g of diallyl terephthalate oligomer having a Mw of 2,360 and an iodine value of 83 was obtained.

This oligomer (A) was used in Example 1.2.

(Synthesis Example 2) Diaryl isophthalate 1300K and bisphenol A ethylene oxide 2 mole adduct 1 as raw materials
580 g of diallylisophthalate oligomer was obtained in the same manner as in Preparation Example 1 except that 92.7 g (0.25 times the mole) was used.

As measured by GPC, Mn=1200, M w "2
850, and the iodine value was 81.

This oligomer (B) was used in Example 3.4. .

(Synthesis Example 3) 600 g of diallyl phthalate and 46.4 g of propylene glycol (0.25 times the mole) and 1.1. 565 g of diallylphthalate-based OJ sesame was obtained in the same manner as in Synthesis Example 1 except that 32.7 g (0.1 mole) of l-1-limethylolpropane was used. G
As measured by PC, M n = 19', 30, M
w=3580, and the iodine value was 79. This oligomer (C) was used in Example 5.6.

(Synthesis Example 4) 300 g of diallyl isophthalate, 300 g of diallyl terephthalate, and 36.3 g of pentaerythritol f (0.2 times the mole) were used as raw materials.

520 g of diallyl terephthalate oligo 7-7 was obtained in the same manner as in Synthesis Example 1 except that F1 was used. As measured by GPC, Mn=1950. Mw=3400, and iodine value was 80. In Examples 7 and 8, this oligomer (D
)It was used.

(Example 1) Diethylene glycol bisallyl carbonate (CR-
39) After adding and mixing 10 g, 4 g of diisopropyl peroxydicarbonate as a radical polymerization initiator was dissolved to obtain a curable composition. This curable composition was poured into a glass mold with a diameter of 50 mm and a thickness of 3 mm.
After heating at 5° C. for 5 hours, the temperature was raised to 80° C. at a rate of 10° C./hour and held at 80° C. for 2 hours to heat cure. After demolding 1
Annealing was performed at 00° C. for 2 hours to obtain a plate-shaped cured product. The obtained cured product was a uniform, colorless and transparent resin.7 The physical property values of the cured product are shown in Table 1.

(Examples 2 to 8, Comparative Examples 1 to 4) A cured product was obtained in the same manner as in Example I except that the components of the oligomer, monomer, and initiator were changed as shown in Table 1.

Table 1 shows the physical property values of the cured product.

Abbreviation Oligomer, to 13. c, D...Each synthesis example 1
．． 2゜3.4.

CR...Diethylene glycol bisallyl carpoy~
-toA I3...AllylbenzoJ--to]3/...benzyl methacrylate XI...-methaxylylene diisocyanate 4...
Pentaerythritol tetrathioglycoleto DIP...diallylisophthalate 132 F...dibenzyl fumarate T I) I)
-...Diisopropyl I liveroxin carbonate [31. ...-Dibutyltin dilaurate [Second Benefits of the Invention 1 The curable composition of the present invention has a relatively high refractive index, yet is extremely easy to mold, and has the greatest advantage of its zero color. The material has a low water absorption rate and a high gaffs transfer temperature.
Shockproof! It is a synthetic resin with extremely well-balanced performance that is excellent in both properties.

Claims (1)

[Claims] (1) Having the structure of the following general formula (I), CH_2=CHCH_2O(COArCOORO)_n
COArCOOCH_2CH=CH_2・・・・・・(
I) (wherein, R is a divalent hydrocarbon residue having 2 to 20 carbon atoms, Ar is a 1,2-, 1,3- or 1,4-phenylene group, and n is a number from 1 to 100) represents.However, if Ar is 1
, 4-phenylene group only. ) and at least 10% by weight of a diallyl phthalate oligomer having an unsaturation degree of 20 to 100 as measured by the Wijs method, a vinyl monomer copolymerizable with the oligomer, and a radical polymerization initiator. A curable composition comprising: (2) In the diallyl phthalate oligomer having the structure of general formula (I) in claim (1), some or all of the divalent hydrocarbon residues having 2 to 20 carbon atoms represented by R have carbon atoms The curable composition according to claim 1, which is an oligomer substituted with a polyol residue having three or more hydroxyl groups. (3) A plastic lens comprising a cured product of the curable composition according to claim (1) or claim (2).