JP2016079197A - Curable resin composition and cured body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition with which LiAlXFparticle, where X is an alkali earth metal, high in usefulness as a neutron scintillator and which is excellent in extraction efficiency of a scintillation light.SOLUTION: There is provided a curable composition containing (A) a fluorine-containing compound represented by the formula (1) of 100 pts.mass, (B) LiAlXFparticle, where X is an alkali earth metal, of 1 to 500 pts.mass based on 100 pts.mass of the (A) component and (C) an optical cation polymerization initiator of effective amount. (1), where RF is a C1 to 10 fluoroalkyl group and m and n are each independently an integer of 3 to 100, m≥n.SELECTED DRAWING: None

Description

  The present invention relates to a polymerizable composition useful for a neutron scintillator. More specifically, the present invention relates to a polymerizable composition that is easy to handle and can be rapidly cured after being formed into an arbitrary shape to produce a scintillator having a desired shape.

  The neutron detector is an elemental technology that supports neutron utilization technology. In the security field such as cargo inspection, academic research field such as structural analysis by neutron diffraction, non-destructive inspection field, or medical field such as boron neutron capture therapy. With the development of neutron utilization technology, higher performance neutron detectors are required.

  Important characteristics required for the neutron detector include neutron detection efficiency and discrimination ability between neutrons and γ rays (hereinafter also referred to as n / γ discrimination ability).

  As a neutron scintillator that exhibits high n / γ discrimination ability, a resin composition system in which particulate inorganic phosphors sensitive to neutrons are dispersed in a resin has already been proposed (Patent Document 1).

International Publication No. 2014/092202 Pamphlet

  In the scintillator of the resin composition, in order to efficiently extract scintillation light, it is required that the inorganic phosphor and the resin have the same refractive index so that the composition itself has good light transmittance.

However, when LiAlXF ₆ particles (X is an alkaline earth metal) having high physical properties as an inorganic phosphor are adopted, the refractive index of LiAlXF ₆ is about 1.39 to 1.41, so a special silicone resin is used. Unless it was adopted, the above-mentioned good light transmittance could not be obtained.

  In addition, such a silicone resin is usually cured by heat, but it takes a relatively long time to cure, so that there is a problem that the inorganic phosphor particles are likely to settle during that time.

  Furthermore, since it is a thermosetting type, it was also difficult to perform defoaming in a state where the viscosity was reduced by applying temperature after mixing the inorganic phosphor and the resin precursor.

  The present inventor has intensively studied in view of the above problems. Further, focusing on the fact that the polymer of the compound having fluoroalkyl has a low refractive index of about 1.37 to 1.41, it is found that if this is photopolymerized, particle sedimentation associated with thermosetting is unlikely to occur. The present invention has been completed.

  That is, the present invention provides (A) 100 parts by mass of a fluorine-containing compound represented by the following formula (1),

(In the above formula, RF is a fluoroalkyl group having 1 to 10 carbon atoms, R ¹ and R ² are each independently a hydrogen atom or a methyl group, and m and n are each independently an integer of 3 to 100. M ≧ n.)
(B) Curability comprising 1 to 500 parts by weight of LiAlXF ₆ particles (X is an alkaline earth metal) and (C) an effective amount of a cationic photopolymerization initiator with respect to 100 parts by weight of component (A). It is a composition.

  According to the present invention, a neutron scintillator that exhibits good n / γ discrimination ability can be provided. That is, since the defoaming operation can be easily performed, bubbles are not mixed in the cured body to reduce the transmittance of the cured body, and it can be cured quickly, so that the uniformity of the composition is maintained. It can be molded and cured as it is, and there is little variation in performance.

  The 1st component of the curable composition of this invention is a fluorine-containing compound shown by following (A) following formula (1).

(In the above formula, RF is a fluoroalkyl group having 1 to 10 carbon atoms, R ¹ and R ² are each independently a hydrogen atom or a methyl group, and m and n are each independently an integer of 3 to 100. M ≧ n.)
RF is a C1-C10 fluoroalkyl group. When the number of carbon atoms exceeds 10, the mechanical properties of the cured product obtained by curing the curable composition of the present invention are undesirably low. Those having 2 to 4 carbon atoms are particularly preferred in view of availability.

  Here, the fluoroalkyl group is one in which part or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms. In the present invention, a compound in which more than half of hydrogen atoms are substituted with fluorine atoms is preferred.

  Specific examples of such a fluoroalkyl group include 1,1,1,3,3,3-hexafluoroisopropyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, 2 , 2,3,3,3-pentafluoropropyl group, 1,1,1,3,3,3-hexafluoroisopropyl group, 2,2,3,4,4,4-hexafluorobutyl group, 2, 2,2-trifluoroethyl group, 2,2,3,3-tetrafluoropropyl group, 2,2,3,3-tetrafluoro-t-pentyl group, 2,2,3,3,4,4- Hexafluorobutyl group, 2,2,3,4,4,4-hexafluoro-t-hexyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, 2,2,3, 3,4,4,5,5-octafluoropentyl group, 3,3,4,4,5,5, , 6-octafluorohexyl group, 2,3,4,5,5,5-hexafluoro-2,4-bis (trifluoromethyl) pentyl group, 2,2,3,3,4,4,5 Examples include 5,5-nonafluoropentyl group.

In the above formula (1), R ¹ and R ² are each independently a hydrogen atom or a methyl group. That is, the compound represented by the formula (1) corresponds to a compound obtained by copolymerizing fluoroalkyl (meth) acrylate and glycidyl (meth) acrylate. In addition, since it is a compound obtained by copolymerization in this way, both ends in Formula (1) are various organic residues according to the used polymerization initiator.

m and n are each independently an integer of 3 to 100, and m ≧ n. When n is larger than m, the refractive index of the resin part of the cured body tends to be too high as compared with the LiAlXF ₆ particles. Preferably, m: n is 20: 1 to 5: 1.

In the present invention, the fluorine-containing compound represented by the above formula (1) may be used alone or in combination of two or more of RF, R ¹ , R 2, m and n. In particular, what is usually available is one obtained by copolymerizing fluoroalkyl (meth) acrylate and glycidyl (meth) acrylate, so that the ratio of m and n is constant and the molecular weight distribution is (m And n have a range).

The second component in the present invention is LiAlXF ₆ particles (X is an alkaline earth metal), that is, LiAlMgF ₆ particles, LiAlCaF ₆ particles, LiAlSrF ₆ particles, and LiAlBaF ₆ particles.

  Since these particles have substantially the same refractive index as the polymers of the components (A) and (B), the cured product obtained by curing the curable composition of the present invention usually has a light transmittance of 30% / cm. As described above, in many cases, it is 60% / cm or more. In particular, it is easy to obtain a cured product exceeding 80% / cm if the monomer components are precisely mixed.

The amount of LiAlXF ₆ particles was (A) and (B) 1 to 500 parts by weight relative to the total amount 100 parts by weight of the component is preferably 10 to 400 parts by weight, particularly preferably 50 to 300 parts by weight. If it is less than 1 part by mass, it is difficult to obtain various effects due to the blending of LiAlXF ₆ particles, and if it exceeds 500 parts by mass, it is difficult to cure the composition because it is difficult to form a paste.

Cured product of the curable composition of the present invention can be used in various known applications as a filler filling a transparent crosslinked polymer, in particular more than a certain amount of the LiAlXF ₆ particles, the ⁶ Li of the Li isotope 30 If it is contained in a high proportion of mol% or more, preferably 50 mol% or more, particularly 80 mol% or more (hereinafter referred to as ⁶ LiAlXF ₆ particles), it can be suitably used as a neutron scintillator. Specifically, by making a cured body in which the ratio of ⁶ LiAlXF ₆ particles in the cured body composition is preferably 5 to 50% by volume, particularly preferably 10 to 40% by volume, the cured body is n / γ. A neutron scintillator with excellent discrimination ability. The volume content can be easily calculated by using the specific gravity of the cured product and the specific gravity of the LiAlXF ₆ particles.

When the cured product of the curable composition of the present invention is used as a neutron scintillator, ⁶ LiAlXF ₆ is doped with a lanthanoid element such as Eu, Ce, or Pr. ⁶ LiAlXF ₆ suitable for such a neutron scintillator is described in detail in Japanese Patent No. 5378356.

In the cured body used as the neutron scintillator, the LiAlXF ₆ particles preferably include not the ⁶ LiAlXF ₆ particles, that is, LiAlXF ₆ particles containing ⁷ Li as a main constituent atom. In order to improve the discrimination ability of n (neutron) / γ (γ ray) of the cured body, it is better that the distance between ⁶ LiAlXF ₆ particles in the cured body acting as an inorganic phosphor is separated, and neutron By blending ⁷ LiAlXF ₆ particles having no capture ability, it becomes easy to appropriately secure this interval in the cured body. Also there is no difference in refractive index is the same LiAlXF ₆ particles, not impaired transparency of the cured product. In this case, the amount of the LiAlXF ₆ particles ^is about 50 to 200% by weight of ₆ LiAlXF 6 particles are suitable.

The ⁶ LiAlXF ₆ particles preferably have a particle size that passes through a sieve having a mesh size of 1000 μm and remains on the sieve having a mesh size of 100 μm, because it is easy to obtain good n / γ discrimination ability. More preferably, the particle size is such that it passes through a 500 μm sieve and remains on a sieve having an opening of 100 μm. The particle size passes through a sieve having an opening of 300 μm and remains on a sieve having an opening of 150 μm. It is particularly preferred.

Moreover, the particle size range of the LiAlXF ₆ particles to be blended in order to ensure the interval between the ⁶ LiAlXF ₆ particles is the same. On the other hand, when blending LiAlXF ₆ particles for the purpose of improving the viscosity of the curable composition, the mechanical strength of the cured product, the heat resistance, etc., there may be a smaller particle size. It may be determined in consideration of ease. In particular, in order to suppress sedimentation of ⁶ LiAlXF ₆ particles in the curable composition, it is useful to adjust the viscosity by blending particles of 100 μm or less. About 10 to 100 parts by mass. Furthermore, in order to impart thixotropy to the curable composition and suppress the sedimentation of the particles, it is also preferable to use a part of which has a particle size of 0.1 μm or less.

  The curable composition of the present invention is cationically polymerizable, and a photocationic polymerization initiator is blended to cure the curable composition. At the start of the cationic photopolymerization, known ones can be used without any particular limitation.

  As the photocationic polymerization initiator, a photoacid generator can be used, and examples thereof include diaryliodonium salt compounds, sulfonium salt compounds, sulfonic acid ester compounds, and halomethyl-substituted S-triazine conductors.

  Among these, diaryliodonium salt compounds and sulfonium salt compounds are excellent in that the polymerization activity is particularly high. Specific examples of diaryliodonium salt compounds include diphenyliodonium, bis (p-chlorophenyl) iodonium, ditolyliodonium, bis (p-tert-butylphenyl) iodonium, p-isopropylphenyl-p-methylphenyliodonium, Bis (m-nitrophenyl) iodonium, p-tert-butylphenylphenyliodonium, p-methoxyphenylphenyliodonium, bis (p-methoxyphenyl) iodonium, p-octyloxyphenylphenyliodonium, p-phenoxyphenylphenyliodonium, etc. Cation and chloride, bromide, p-toluenesulfonate, trifluoromethanesulfonate, tetrafluoroborate, tetrakispentafluorophenyl volley And diaryl iodonium salt compounds comprising anions such as tetrakispentafluorophenyl gallate, hexafluorophosphate, hexafluoroarsenate and hexafluoroantimonate.

  Among these, from the viewpoint of solubility, p-toluenesulfonate, trifluoromethanesulfonate, tetrafluoroborate, tetrakispentafluorophenylborate, tetrakispentafluorophenylgallate, hexafluorophosphate, hexafluoroarsenate, hexafluoro Hexafluoroantimonate and tetrakispentafluoro can be suitably used as compounds having an antimonate as an anion, and are low in nucleophilicity and can be stably stored as a polymerizable compound in a state where light irradiation is not performed. A compound having phenylborate or tetrakispentafluorophenylgallate as an anion can be preferably used.

  Examples of sulfonium salt compounds include dimethylphenacylsulfonium, dimethylbenzylsulfonium, dimethyl-4-hydroxyphenylsulfonium, dimethyl-4-hydroxynaphthylsulfonium, dimethyl-4,7-dihydroxynaphthylsulfonium, dimethyl-4,8- Cations such as dihydroxynaphthylsulfonium, triphenylsulfonium, p-tolyldiphenylsulfonium, p-tert-butylphenyldiphenylsulfonium, diphenyl-4-phenylthiophenylsulfonium, chloride, bromide, p-toluenesulfonate, trifluoromethanesulfonate , Tetrafluoroborate, tetrakispentafluorophenylborate, tetrakispentafluorophenylgallate, hexaful Examples thereof include sulfonium salt compounds composed of anions such as orophosphate, hexafluoroarsenate and hexafluoroantimonate.

  These photoacid generators may be used singly or in combination as needed. The amount of these photoacid generators used is not particularly limited as long as the polymerization can be initiated by light irradiation, but an appropriate rate of polymerization progress and various physical properties of the resulting cured product (for example, weather resistance) In general, 0.001 to 10 parts by mass is preferably used with respect to 100 parts by mass in total of the components (A) and (B), preferably 0.05 to 5 masses. Part is good.

  The photoacid generator as described above usually has many compounds that do not absorb in the near ultraviolet to visible range, and a special light source is often required to excite the polymerization reaction. Therefore, it is preferable that a compound having absorption in the near ultraviolet to visible region is further added as a sensitizer in addition to the photoacid generator.

  Examples of the compound used as such a sensitizer include acridine dyes, benzoflavine dyes, condensed polycyclic aromatic compounds such as anthracene and perylene, and phenothiazine.

  Among these sensitizers, a condensed polycyclic aromatic compound is preferable in terms of good polymerization activity, and a structure in which a saturated carbon atom having at least one hydrogen atom is bonded to the condensed polycyclic aromatic ring. Condensed polycyclic aromatic compounds having are preferred.

  Specific examples of such condensed polycyclic aromatic compounds having a structure in which a saturated carbon atom having at least one hydrogen atom is bonded to a condensed polycyclic aromatic ring include 1-methylnaphthalene and 1-ethylnaphthalene. 1,4-dimethylnaphthalene, acenaphthene, 1,2,3,4-tetrahydrophenanthrene, 1,2,3,4-tetrahydroanthracene, benzo [f] phthalane, benzo [g] chroman, benzo [g] isochroman, N-methylbenzo [f] indoline, N-methylbenzo [f] isoindoline, phenalene, 4,5-dimethylphenanthrene, 1,8-dimethylphenanthrene, acephenanthrene, 1-methylanthracene, 9-methylanthracene, 9-ethylanthracene , 9-cyclohexylanthracene, 9,10-dimethyl Luanthracene, 9,10-diethylanthracene, 9,10-dicyclohexylanthracene, 9-methoxymethylanthracene, 9- (1-methoxyethyl) anthracene, 9-hexyloxymethylanthracene, 9,10-dimethoxymethylanthracene, 9- Dimethoxymethylanthracene, 9-phenylmethylanthracene, 9- (1-naphthyl) methylanthracene, 9-hydroxymethylanthracene, 9- (1-hydroxyethyl) anthracene, 9,10-dihydroxymethylanthracene, 9-acetoxymethylanthracene 9- (1-acetoxyethyl) anthracene, 9,10-diacetoxymethylanthracene, 9-benzoyloxymethylanthracene, 9,10-dibenzoyloxymethylanthracene, 9 -Ethylthiomethylanthracene, 9- (1-ethylthioethyl) anthracene, 9,10-bis (ethylthiomethyl) anthracene, 9-mercaptomethylanthracene, 9- (1-mercaptoethyl) anthracene, 9,10-bis (Mercaptomethyl) anthracene, 9-ethylthiomethyl-10-methylanthracene, 9-methyl-10-phenylanthracene, 9-methyl-10-vinylanthracene, 9-allylanthracene, 9,10-diallylanthracene, 9-chloro Methyl anthracene, 9-bromomethylanthracene, 9-iodomethylanthracene, 9- (1-chloroethyl) anthracene, 9- (1-bromoethyl) anthracene, 9- (1-iodoethyl) anthracene, 9,10-dichloromethylanthracene 9,10-dibromomethylanthracene, 9,10-diiodomethylanthracene, 9-chloro-10-methylanthracene, 9-chloro-10-ethylanthracene, 9-bromo-10-methylanthracene, 9-bromo-10 -Ethylanthracene, 9-iodo-10-methylanthracene, 9-iodo-10-ethylanthracene, 9-methyl-10-dimethylaminoanthracene, acanthrene, 7,12-dimethylbenz (a) anthracene, 7,12- Dimethoxymethylbenz (a) anthracene, 5,12-dimethylnaphthacene, collanthrene, 3-methylcholanthrene, 7-methylbenzo (a) pyrene, 3,4,9,10-tetramethylperylene, 3,4,9, 10-tetrakis (hydroxymethyl) perylene, bio Nsuren, Isoviolanthrone Ren, 5,12-dimethyl-naphthacene, 6,13-dimethyl pentacene, 8,13- dimethyl penta Fen, 5,16- dimethyl hexamethylene Sen, 9,14- dimethyl hexa Fen and the like.

  Examples of the condensed polycyclic aromatic compound other than the above include naphthalene, phenanthrene, anthracene, naphthacene, benz [a] anthracene, pyrene, perylene and the like.

  Among these condensed polycyclic aromatic compounds, a compound having absorption in the visible range is preferable and a compound having maximum absorption in the visible range, which can excite polymerization with visible light in consideration of harm to the living body. Is more preferable. Further, these condensed polycyclic aromatic compounds may be used in combination with a plurality of compounds as necessary.

  The addition amount of the condensed polycyclic aromatic compound also varies depending on the other components to be combined and the kind of the polymerizable monomer, but the amount of the condensed polycyclic aromatic compound is usually 0 with respect to 1 mol of the above-mentioned photoacid generator. 0.001 to 20 mol, and preferably 0.005 to 10 mol.

  Furthermore, it is preferable to add an oxidized photoradical generator in addition to the condensed polycyclic aromatic compound because the polymerization activity is further improved. An oxidized photoradical generator is a compound that generates radicals when excited by light irradiation, and is a so-called hydrogen abstraction type radical generator that generates radicals by extracting hydrogen from a hydrogen donor by excitation. Generates radicals by causing self-cleavage (self-cleaving radical generator), and then the radicals withdrawing electrons from the electron donor, and radicals that are excited by light irradiation and withdraw electrons directly from the electron donor. The photoradical generator is a mechanism that generates active radical species by excitation by light irradiation, such as the following. These oxidation type photo radical generators are not particularly limited, and known compounds may be used. However, in terms of higher polymerization activity when irradiated with light compared to other compounds, hydrogen abstraction type light radical generators may be used. A radical generator is preferred, and among them, a diaryl ketone compound, an α-diketone compound or a ketocoumarin compound is particularly preferred.

  Specific examples of the diaryl ketone compound include 4,4-bis (dimethylamino) benzophenone, 9-fluorenone, 3,4-benzo-9-fluorenone, 2-dimethylamino-9-fluorenone, and 2-methoxy-9-fluorenone. 2-chloro-9-fluorenone, 2,7-dichloro-9-fluorenone, 2-bromo-9-fluorenone, 2,7-dibromo-9-fluorenone, 2-nitro-9-fluorenone, 2-acetoxy-9 -Fluorenone, benzanthrone, anthraquinone, 1,2-benzanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 1-dimethylaminoanthraquinone, 2,3-dimethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone 1,5-dichloroanthraquinone, 1,2-dimethoxyanthraquinone, 1,2-diacetoxy-anthraquinone, 5,12-naphthacenequinone, 6,13-pentacenequinone, xanthone, thioxanthone, 2,4-dimethylthioxanthone, 2,4 -Diethylthioxanthone, 2-chlorothioxanthone, 9 (10H) -acridone, 9-methyl-9 (10H) -acridone, dibenzosuberenone and the like can be mentioned.

  Specific examples of α-diketone compounds include camphorquinone, benzyl, diacetyl, acetylbenzoyl, 2,3-pentadione, 2,3-octadione, 4,4′-dimethoxybenzyl, 4,4′-oxybenzyl, 9,10-phenanthrenequinone, acenaphthenequinone, etc. are mentioned.

  Examples of ketocoumarin compounds include 3-benzoylcoumarin, 3- (4-methoxybenzoyl) coumarin, 3-benzoyl-7-methoxycoumarin, 3- (4-methoxybenzoyl) 7-methoxy-3-coumarin, and 3-acetyl- Examples thereof include 7-dimethylaminocoumarin, 3-benzoyl-7-dimethylaminocoumarin, 3,3′-coumarinoketone, 3,3′-bis (7-diethylaminocoumarino) ketone, and the like.

  These oxidized photoradical generators can be used alone or in admixture of two or more. Moreover, although the addition amount varies depending on the other components to be combined and the kind of the polymerizable monomer, the photoradical generator is usually 0.001 to 20 mol relative to 1 mol of the photoacid generator described above. It is preferable that it is 005-10 mol.

In the curable composition of the present invention, in order to adjust the refractive index of the resin portion of the cured body to further match the refractive index with LiAlXF ₆ , or to improve the mechanical and thermal properties of the cured body, Cationic polymerizable compounds other than those represented by the formula (1) may be contained.

  Examples of such cationically polymerizable compounds include epoxy compounds other than those represented by the formula (1), oxetane compounds, alkenyl ether compounds, and the like. Epoxy compounds and oxetane compounds are preferable from the viewpoint of less coloring after curing, and oxetane compounds are preferable from the viewpoint of faster curing.

  The oxetane compound in the present invention is the following formula:

(In the formula, m is an integer of 0 to 6, R ³ is a monovalent group, and when m is 2 to 6, each R ³ may be the same or different, and R ³ may be bonded to each other to form a ring.)
And a compound having a four-membered ether (oxetane ring) functional group.

The oxetane compound used in the present invention is not particularly limited as long as it has a cationically polymerizable oxetane functional group, and a known compound can be used. In the above formula, one or two oxetane compounds can be used. of R ³ is bonded to the 3-position of the oxetane ring, while the other positions compound unbound R ³ is preferred. Specific examples of the oxetane compound include 3-methyl-3-oxetanylmethanol, 3-ethyl-3-oxetanylmethanol, 3-ethyl-3-phenoxymethyloxetane, 3,3-diethyloxetane, and 3-ethyl-3. Those having one oxetane ring such as-(2-ethylhexyloxy) oxetane, 1,4-bis (3-ethyl-3-oxetanylmethyloxy) benzene, 4,4'-bis (3-ethyl-3- Oxetanylmethyloxy) biphenyl, 4,4′-bis (3-ethyl-3-oxetanylmethyloxymethyl) biphenyl, ethylene glycol bis (3-ethyl-3-oxetanylmethyl) ether, bis (3-ethyl-3-oxetanyl) Methyl) diphenoate, trimethylolpropane tris (3-ethyl) 3-oxetanylmethyl) ether, pentaerythritol tetrakis (3-ethyl-3-oxetanylmethyl) ether, or a compound shown below

And compounds having two or more oxetane rings. Use of a fluorine-containing oxetane monomer as disclosed in JP-A No. 2000-191652 and JP-A No. 2011-225464 is also preferable in terms of adjusting the refractive index. These oxetane compounds may be used in combination.

  In particular, those having two or more oxetane functional groups in one molecule are suitably used from the viewpoint of physical properties of the obtained cured product.

In this invention, (B) component is 1-50 mass parts with respect to 100 mass parts of said (A) component, Preferably it is 1-30 mass parts, Most preferably, it is 2-10 mass parts. When the component (B) is less than 1 part by mass, a sufficient polymerization rate cannot be obtained. Further, as the amount of the component (B) increases, the refractive index tends to increase, and the refractive index tends to be separated from the LiAlXF ₆ particles described later.

  The curable composition of the present invention may contain components other than those described above as long as the object and effects of the present invention are not impaired. Specific examples of such components include fillers, surfactants, neutron-insensitive phosphors, thickeners, polymerization inhibitors, polymerization regulators, and the like having the same refractive index.

  The manufacturing method of the curable composition of this invention is not specifically limited, What is necessary is just to employ | adopt suitably the well-known manufacturing method of the curable composition containing a filler. Particularly preferable methods are as follows.

A predetermined amount of the components (A) and (B), the LiAlXF ₆ particles, and the photocationic polymerization initiator are put into a container having a stirring / kneading function. In addition, you may melt | dissolve in (A) component and / or (B) component in advance at the time of radical polymerization start. In addition, it is preferable that the component (A) and the component (B) are first input and then the LiAlXF ₆ particles are gently input from above. If the LiAlXF ₆ particles are introduced first or the LiAlXF ₆ particles are vigorously introduced, bubbles easily enter the curable composition (and the cured product).

The container is preferably one that can be kneaded under reduced pressure or under vacuum, and it is preferable from the viewpoint that air bubbles are not mixed after starting the stirring and kneading after sufficiently reducing the pressure after adding each component. The LiAlXF ₆ particles can be charged in a plurality of times, and in this case, it is preferable to stop the kneading and return to the normal pressure before charging and then restart the decompression and kneading again.

Heating is also suitable for stirring and kneading. Since the viscosity of the monomer component is reduced by heating, defoaming easily occurs. When a polymer is used as a viscosity modifier, the viscosity greatly decreases during heating and is easily defoamed, while the viscosity increases when returned to room temperature, and the precipitation of LiAlXF ₆ particles can be effectively suppressed. There are advantages.

  If kneaded sufficiently uniformly, the curable composition of the present invention can be obtained. The obtained curable composition may be handled with the same care as handling a general curable composition such as mixing of bubbles during handling.

  The curable composition of the present invention may be filled in a mold or the like having a desired shape and then irradiated with light. Further, the shape may be corrected by further cutting, grinding, polishing or the like after curing.

Claims (3)

(A) 100 parts by mass of a fluorine-containing compound represented by the following formula (1),

(In the above formula, RF is a fluoroalkyl group having 1 to 10 carbon atoms, R ¹ and R ² are each independently a hydrogen atom or a methyl group, and m and n are each independently an integer of 3 to 100. M ≧ n.)
(B) Curability comprising 1 to 500 parts by weight of LiAlXF ₆ particles (X is an alkaline earth metal) and (C) an effective amount of a cationic photopolymerization initiator with respect to 100 parts by weight of component (A). Composition.   (D) 1-50 mass parts of cationically polymerizable compounds other than those represented by the above formula (1) are included, and the amount of the (B) component is 100 parts by mass in total of the (A) component and the (B) component. The curable composition according to claim 1, wherein the content is 1 part by mass or more.   A cured product obtained by curing the curable composition according to claim 1.