Curable composition and cured product thereof

Abstract

The present invention provides: a curable composition which contains a bismuth compound, wherein a phosphoric acid ester having a (meth)acryloyl group is bonded to bismuth, and a nitrile compound having a radically polymerizable carbon-carbon double bond; a cured body which is obtained by curing this curable composition; a multilayer body which is composed of the above-described cured body and a cured body that is obtained by curing a photochromic curable composition; and a radiation protective material which is formed of the above-described cured body or the above-described multilayer body.

Description

[Technical Field]

[0001] The present invention relates to a novel curable composition containing a bismuth compound, and a novel cured product obtained by curing the curable composition. [Background technology]

[0002] The effect of X-rays on the crystalline lens of the eye, which can induce cataracts, is a major problem, and optical materials that can effectively block X-rays are desired. Lead glass is commonly known as such an optical material, but while it has high X-ray blocking ability, it has the problem of being heavy and unsuitable for regular use. If the objective is to protect against stray X-rays that affect the human body indirectly by reflection or diffusion, rather than direct X-ray irradiation, then so-called light shielding materials are sufficient, and for this reason optical shielding materials using lightweight acrylic lead are also used. However, lead is harmful to the environment, and there is a strong demand for lead-free alternatives, even in light shielding materials.

[0003] While many metal elements, such as barium, antimony, tin, and tungsten, have been proposed as potential lead replacements, research is underway into materials containing bismuth. Bismuth has a long history of use as a gastrointestinal medicine and is harmless to the human body, yet has a high X-ray blocking capacity, making it a suitable lead replacement.

[0004] For example, a method for producing a material containing bismuth is known in which bismuth or an inorganic bismuth compound is directly mixed into an organic material (see Patent Document 1). This method allows bismuth or an inorganic bismuth compound to be blended into various organic materials.

[0005] However, this method leaves room for improvement in that it requires extensive kneading to fully disperse the bismuth or inorganic bismuth compound in the organic material, and the resulting material is colored and opaque, making it unsuitable for applications such as protective eyewear.

[0006] It is known that organic groups can be coordinated to bismuth to facilitate dispersion in organic materials (see Patent Document 2, and Non-Patent Documents 1 and 2). By using a compound in which an organic group is coordinated to bismuth, the compound becomes more compatible with organic materials, making it easier to disperse the compound in the organic material. Examples of organic groups that can be coordinated to bismuth include alkyl or aryl groups (see Patent Document 2) and polyethylene glycol chains (see Non-Patent Documents 1 and 2).

[0007] In order to obtain a material in which a bismuth compound is dispersed in an organic material more simply and efficiently, it is preferable to employ a method in which, for example, a polymerizable radically polymerizable monomer and a bismuth compound are mixed to obtain a curable composition, and then the curable composition is polymerized to obtain a cured product.

[0008] However, the above-mentioned compound in which an organic group is coordinated to bismuth does not have a polymerizable group that can participate in the polymerization of a radically polymerizable monomer, and therefore, when this compound is used, the curable composition may not be sufficiently polymerized, and a cured product may not be obtained.

[0009] When attempting to disperse bismuth in a cured product using a curable composition containing a radically polymerizable monomer, it is conceivable to use a compound in which a polymerizable group such as (meth)acrylic acid is coordinated to bismuth (see Non-Patent Document 3 and Patent Document 3).

[0010] The compound described in Non-Patent Document 3 has dimethyl sulfoxide (DMSO) coordinated in addition to (meth)acrylic acid, and has excellent solubility. However, since the compound described in Non-Patent Document 3 contains DMSO, it is difficult to crosslink (polymerize) it to a high degree, leaving room for improvement. Furthermore, Non-Patent Document 3 only discloses copolymerization with methyl methacrylate in dimethylformamide (DMF) to obtain a cured product. As a result of investigations by the present inventors, it was found that since polymerization is performed in solution, it is difficult to incorporate bismuth at a high concentration into the cured product.

[0011] On the other hand, the compound described in Patent Document 3 has salicylic acid bonded to it in addition to (meth)acrylic acid. However, according to the inventors' investigations, the compound has extremely low solubility in common organic solvents as well as other monomers, and as a result, it has been found that it is difficult to incorporate bismuth at a high concentration into the cured product. Furthermore, it has been found that when a bismuth-containing compound such as the compound described above is mixed with a common monomer and cured, it has extremely low impact resistance, and the cured product itself only has strength that is so low that it easily breaks even when dropped. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-83288 [Patent Document 2] Special Publication No. 10-512877 [Patent Document 3] Special Publication No. 2017-516991 [Non-patent literature]

[0013] [Non-Patent Document 1] Materials Chemistry and Physics, Vol.99, pp.174-180(2006) [Non-patent document 2] American Journal of Engineering Research, Vol.3, pp.162-165(2014) [Non-patent document 3] Chemical Communications, Vol.47, pp.6353-6355(2011) Summary of the Invention [Problem to be solved by the invention]

[0014] An object of the present invention is to provide a curable composition that contains a polymerizable bismuth compound that has high solubility in organic materials, particularly in radically polymerizable monomers, and that can form a cured product that has reduced coloration, high transparency, and practical mechanical properties, and a cured product obtained by curing the curable composition. [Means for solving the problem]

[0015] Specific means for solving the above problems include the following embodiments. <1> A curable composition comprising a bismuth compound in which a phosphate ester having a (meth)acryloyl group is bonded to the bismuth, and a nitrile compound having a radically polymerizable carbon-carbon double bond.

[0016] <2> The composition further contains a compound having one radically polymerizable carbon-carbon double bond, which is different from the bismuth compound and the nitrile compound. <1> The curable composition according to claim 1.

[0017] <3> The bismuth compound includes a bismuth compound in which salicylic acid or (meth)acrylic acid and a phosphate ester having a (meth)acryloyl group are bonded to bismuth. <1> or <2> The curable composition according to claim 1.

[0018] <4> The following formula (1): [ka] (In the formula, l represents an integer of 7 to 14.) and a compound represented by the following formula (2): [ka] (In the formula, n and m each independently represent an integer of 1 to 15, and n+m=2 to 30.) Further containing at least one compound selected from the group consisting of compounds represented by the formula: <1> ~ <3> The curable composition according to any one of the preceding claims.

[0019] <5> Further containing a photochromic compound, <1> ~ <4> The curable composition according to any one of the preceding claims.

[0020] <6> <1> ~ <5> 1. A cured product obtained by curing the curable composition according to any one of claims 1 to 9.

[0021] <7> <1> ~ <4> 1. A laminate comprising a cured product obtained by curing the curable composition according to any one of claims 1 to 9 and a cured product obtained by curing a photochromic curable composition containing a photochromic compound.

[0022] <8> <6> or the cured body according to <7> A radiation protection material comprising the laminate according to claim 1. [Effects of the Invention]

[0023] According to the present invention, it is possible to provide a curable composition that contains a polymerizable bismuth compound that has high solubility in organic materials, particularly in radically polymerizable monomers, and that is capable of forming a cured product that has reduced coloration, high transparency, and practical mechanical properties, and a cured product obtained by curing the curable composition. DETAILED DESCRIPTION OF THE INVENTION

[0024] Specific embodiments to which the present invention is applied will be described in detail below. In this specification, unless otherwise specified, the expression "x to y" using numerical values ​​x and y means "greater than or equal to x and less than or equal to y." In such an expression, when a unit is assigned only to the numerical value y, the unit is also applied to the numerical value x. In addition, in this specification, the term "(meth)acryloyl" means both "acryloyl" and "methacryloyl." Similarly, the term "(meth)acrylic acid" means both "acrylic acid" and "methacrylic acid."

[0025] ≪Curable composition≫ The curable composition according to the present embodiment contains a bismuth compound in which a phosphate ester having a (meth)acryloyl group is bonded to bismuth (hereinafter also referred to as a "phosphate ester-bonded bismuth compound"), and a nitrile compound having a radically polymerizable carbon-carbon double bond.

[0026] <Phosphate ester-bonded bismuth compound> A phosphate ester-bonded bismuth compound is a compound in which a phosphate ester (hereinafter simply referred to as "phosphate ester") having a (meth)acryloyl group is bonded to bismuth. Because this compound has high solubility, particularly in a solution of a radically polymerizable monomer, it is possible to incorporate a high concentration of bismuth into the cured product, thereby improving the physical properties of the cured product. This phosphate ester-bonded bismuth compound has a higher solubility in radically polymerizable monomers than bismuth subsalicylate, which will be described later.

[0027] The bonding form between bismuth and the phosphate ester having a (meth)acryloyl group is not particularly limited, and may be either an ionic bond or a coordinate bond.

[0028] Examples of phosphate ester-bonded bismuth compounds include those in which the phosphate ester is formed from a phosphate monoester having one (meth)acryloyl group (e.g., 2-(methacryloyloxy)ethyl dihydrogen phosphate) or a phosphate diester having two (meth)acryloyl groups (e.g., bis[2-(methacryloyloxy)ethyl] hydrogen phosphate). The phosphate ester may be formed solely from either a phosphate monoester having one (meth)acryloyl group or a phosphate diester having two (meth)acryloyl groups, or may be formed from both.

[0029] When the phosphate ester is formed from a phosphate monoester having one (meth)acryloyl group and a phosphate diester having two (meth)acryloyl groups, the following ratio is preferred to improve solubility in the radical polymerizable monomer and suppress aggregation of the bismuth component. Specifically, it is preferred to have 1 mole of the phosphate ester derived from the phosphate monoester having one (meth)acryloyl group and 0.05 to 3 moles of the phosphate ester derived from the phosphate diester having two (meth)acryloyl groups. The amount of the phosphate ester derived from the phosphate diester is more preferably 0.1 to 2 moles, and even more preferably 0.15 to 1 mole. The advantage of including both bismuth having one (meth)acryloyl group and bismuth having two (meth)acryloyl groups is believed to be due to the fact that the bismuth has suitable bonding sites for the bismuth having one (meth)acryloyl group (having a divalent phosphate group) and the bismuth having two (meth)acryloyl groups (having a monovalent phosphate group), and these suitable bonding sites are present in a ratio of 0.05 to 3 moles of phosphate ester derived from the bismuth having one (meth)acryloyl group per mole of phosphate ester derived from the bismuth having one (meth)acryloyl group. Furthermore, the presence of the bismuth having two (meth)acryloyl groups in this ratio reduces the bismuth concentration, but improves its solubility in radically polymerizable monomers. This also results in the advantage of allowing the bismuth component to be present in a well-balanced, high concentration in the cured product.

[0030] The phosphate ester-bonded bismuth compound may have other compounds bonded thereto, as long as the phosphate ester is bonded thereto. Specifically, salicylic acid and / or (meth)acrylic acid may be further bonded thereto. When a phosphate ester and salicylic acid and / or (meth)acrylic acid are bonded to the same bismuth, in order to improve solubility in a radically polymerizable monomer, the ratio of the phosphate ester to the salicylic acid and / or (meth)acrylic acid is preferably 0.1 to 10 moles, more preferably 0.1 to 5 moles, even more preferably 0.1 to 1 mole, and particularly preferably 0.1 to 0.5 moles, of salicylic acid and / or (meth)acrylic acid per mole of the phosphate ester, ie, 1 mole of the salicylic acid and / or (meth)acrylic acid. When two or more types of phosphate esters are present, the above range is based on the total number of moles of the phosphate esters.

[0031] The phosphate ester-bonded bismuth compound is a compound in which a phosphate ester having a (meth)acryloyl group is bonded to bismuth, and the presence of a phosphate ester having a (meth)acryloyl group can be confirmed by its production method or by elemental analysis using IR, NMR (nuclear magnetic resonance spectroscopy), MALDI-TOF-MS (matrix-assisted laser desorption / ionization time-of-flight mass spectrometry), energy dispersive X-ray spectrometry (EDS), etc. Furthermore, these methods can determine the number of bonded phosphate esters, salicylic acid, and (meth)acrylic acid.

[0032] Suitable phosphate-bonded bismuth compounds include those represented by the following formulas (3) to (5).

[0033] [ka]

[0034] [ka]

[0035] [ka]

[0036] In the formula, each R independently represents a hydrogen atom or a methyl group. In the formula (3), a+x+y+z=3, where x represents the number of moles of 2-((meth)acryloyloxy)ethyl hydrogen phosphate residues, y represents the number of moles of phenyl-2-((meth)acryloyloxy)ethyl phosphate residues, z represents the number of moles of bis[2-((meth)acryloyloxy)ethyl]phosphate residues, and a represents the number of moles of (meth)acrylic acid residues. In the formula (4), 2b+u+v+w=3, where u represents the number of moles of 2-((meth)acryloyloxy)ethyl hydrogen phosphate residues, v represents the number of moles of phenyl-2-((meth)acryloyloxy)ethyl phosphate residues, w represents the number of moles of bis[2-((meth)acryloyloxy)ethyl]phosphate residues, and b represents the number of moles of salicylic acid residues. In the above formula (5), 2c+q+r+2s+t=3, where q represents the number of moles of 2-((meth)acryloyloxy)ethyl hydrogen phosphate residues, r represents the number of moles of phenyl-2-((meth)acryloyloxy)ethyl phosphate residues, s represents the number of moles of 2-((meth)acryloyloxy)ethyl phosphate residues, t represents the number of moles of bis[2-((meth)acryloyloxy)ethyl]phosphate residues, and c represents the number of moles of salicylic acid residues.

[0037] The phosphate-bonded bismuth compounds represented by the above formulas (3) to (5) may not be single compounds but may be mixtures of multiple compounds. In such cases, the number of moles of each residue mentioned above refers to the number of moles of the entire mixture.

[0038] In the above formula (3), in consideration of obtaining a phosphate ester-bonded bismuth compound that can be produced at low temperatures and has little coloration, when a = 0, x:y:z = 1:0.05-3:0.5-30 is preferable, x:y:z = 1:0.1-2:1-20 is more preferable, and x:y:z = 1:0.15-1:1.5-10 is even more preferable. In order to further reduce coloration, a = 0 and y = 0 may also be satisfied.

[0039] In addition, in the above formula (3), when a is other than 0, it is preferable that a:(x+y+z)=0.1 to 10:1, more preferably a:(x+y+z)=0.1 to 5:1, even more preferably a:(x+y+z)=0.1 to 1:1, and particularly preferably a:(x+y+z)=0.1 to 5:1. Even in this case, it is preferable that x:y:z=1:0.05 to 3:0.5 to 30, more preferably x:y:z=1:0.1 to 2:1 to 20, and even more preferably x:y:z=1:0.15 to 1:1.5 to 10.

[0040] In the above formula (4), when b=0, it is the same as replacing x with u, y with v, and z with w in the above definition.

[0041] In addition, in the above formula (4), when b is other than 0, it is preferable that b:(u+v+w)=1:0.1 to 30, more preferably b:(u+v+w)=1:0.2 to 20, even more preferably b:(u+v+w)=1:0.3 to 10, and particularly preferably b:(u+v+w)=1:0.5 to 5. In this case, it is preferable that u:v:w=1:20 to 0.05:40 to 0.1, more preferably u:v:w=1:10 to 0.1:20 to 0.2, and even more preferably u:v:w=1:5 to 0.2:10 to 0.4.

[0042] Among these, it is preferable to include a compound in which bismuth subsalicylate and phenyl-2-((meth)acryloyloxy)ethyl hydrogen phosphate are bonded together.

[0043] In the above formula (5), when c=0, q:r:s:t=1:0.1-50:0.05-20:0.1-40 is preferable, q:r:s:t=1:0.3-30:0.1-10:0.2-20 is more preferable, and q:r:s:t=1:0.5-20:0.2-5:0.4-10 is even more preferable.

[0044] In addition, in the above formula (5), when c is other than 0, it is preferable that c:(q+r+s+t)=1:0.1 to 30, more preferably c:(q+r+s+t)=1:0.2 to 20, even more preferably c:(q+r+s+t)=1:0.3 to 10, and particularly preferably c:(q+r+s+t)=1:0.5 to 5. Even in this case, it is preferable that q:r:s:t=1:0.1 to 50:0.05 to 20:0.1 to 40, more preferably q:r:s:t=1:0.3 to 30:0.1 to 10:0.2 to 20, and even more preferably q:r:s:t=1:0.5 to 20:0.2 to 5:0.4 to 10.

[0045] The content of the phosphate ester-bonded bismuth compound is, for example, preferably 5 to 95 mass %, more preferably 10 to 90 mass %, and even more preferably 15 to 85 mass %, relative to the total amount of the curable composition according to this embodiment.

[0046] The curable composition according to this embodiment may contain, in addition to the phosphate ester-bonded bismuth compound, a phosphate compound that is a by-product during the production of the phosphate ester-bonded bismuth compound and unreacted raw materials.

[0047] Examples of phosphoric acid compounds produced as by-products during production include dimers of phosphoric acid monoesters having one (meth)acryloyl group, dimers of phosphoric acid diesters having two (meth)acryloyl groups, and esters of phosphoric acid with bismuth salicylate or bismuth (meth)acrylate.

[0048] Examples of unreacted raw materials include a phosphoric acid monoester having one (meth)acryloyl group, a phosphoric acid diester having two (meth)acryloyl groups, bismuth salicylate, and bismuth (meth)acrylate.

[0049] Removal of the phosphate compound and unreacted raw materials produced as by-products during production of the phosphate ester-bonded bismuth compound requires a great deal of industrial effort, and these by-product phosphate compounds and unreacted raw materials contribute to improving the solubility in the radical polymerizable monomer. Therefore, the curable composition according to this embodiment preferably contains these by-product phosphate compounds and unreacted raw materials.

[0050] The curable composition according to the present embodiment may also contain a compound in which bismuth oxide is bonded to a phosphate ester having a (meth)acryloyl group, (meth)acrylic acid, and / or salicylic acid (hereinafter also referred to as a "bismuth oxide-derived compound"). Although the structure of this bismuth oxide-derived compound is unclear, it is believed that a hydroxyl group formed on the surface of the bismuth oxide is bonded to a carboxyl group of the phosphate ester, (meth)acrylic acid, or salicylic acid. It is very difficult to separate this bismuth oxide-derived compound from the phosphate ester-bonded bismuth compound. Therefore, when a bismuth oxide-derived compound is by-produced, it is preferable to use the composition containing the bismuth oxide-derived compound. When a bismuth oxide-derived compound is by-produced, it is desirable to adjust the amount of the bismuth oxide-derived compound within a range that does not reduce the solubility of the phosphate ester-bonded bismuth compound by adjusting the production conditions, etc., so as not to impair the solubility of the bismuth oxide-derived compound. The presence of a bismuth oxide-derived compound can be comprehensively determined by the production conditions or by methods such as IR, NMR, and X-ray photoelectron spectroscopy (XPS).

[0051] [Method of producing phosphate ester-bonded bismuth compound] The phosphate ester-bonded bismuth compound is preferably produced, for example, by reacting bismuth (meth)acrylate or bismuth subsalicylate with a phosphate ester having a (meth)acryloyl group. More specifically, the phosphate ester-bonded bismuth compound is preferably produced by reacting bismuth (meth)acrylate or bismuth subsalicylate with a phosphate ester having a (meth)acryloyl group in an aliphatic hydrocarbon solvent or aromatic solvent, optionally adding a polymerization inhibitor, followed by dehydration.

[0052] (Bismuth (meth)acrylate and bismuth subsalicylate) Bismuth (meth)acrylate is a compound in which salicylic acid is bonded to bismuth. Bismuth subsalicylate is a compound in which salicylic acid is bonded to bismuth, and is represented by the following formula (6).

[0053] [ka]

[0054] There are no particular limitations on the bismuth (meth)acrylate and bismuth subsalicylate, and they can be produced by known methods, or commercially available products can also be used.

[0055] (Phosphate ester having a (meth)acryloyl group) Commercially available phosphate esters having a (meth)acryloyl group can be used. The phosphate ester may be a phosphate ester having one (meth)acryloyl group (hereinafter also referred to as a "monofunctional phosphate ester") or a phosphate ester having two (meth)acryloyl groups (hereinafter also referred to as a "bifunctional phosphate ester"). Examples of monofunctional phosphate esters include 2-(methacryloyloxy)ethyl dihydrogen phosphate and diphenyl-2-methacryloyloxyethyl phosphate. Examples of bifunctional phosphate esters include bis[2-(methacryloyloxy)ethyl] hydrogen phosphate and [2-(methacryloyloxy)ethyl] phenyl hydrogen phosphate. Naturally, a mixture of a monofunctional phosphate ester and a bifunctional phosphate ester may be used in the reaction.

[0056] The amount of the phosphate ester used may be determined so as to obtain the desired phosphate ester-bonded bismuth compound. Specifically, the amount of the phosphate ester used is preferably in the range of 0.3 to 10 moles per mole of the total of bismuth (meth)acrylate and bismuth subsalicylate.

[0057] In addition, in this embodiment, in order to improve compatibility, a phosphate triester such as diphenyl-2-methacryloyloxyethyl phosphate, phenylbis[2-(methacryloyloxyethyl)]phosphate, or tris[2-(methacryloyloxyethyl)]phosphate may be further added as a phosphate ester having a (meth)acryloyl group.

[0058] Among them, when a phosphate triester having a phenyl group, such as diphenyl-2-methacryloyloxyethyl phosphate or phenylbis[2-(methacryloyloxyethyl)]phosphate, is used, it becomes possible to successfully introduce a monovalent phenyl phosphate diester having one (meth)acryloyl group in the above formulas (3) to (5).

[0059] The amount of the phosphate triester used is preferably 0.1 to 20 mol, more preferably 0.2 to 5 mol, per 1 mol of the total of the phosphate ester having one (meth)acryloyl group and the phosphate ester having two (meth)acryloyl groups.

[0060] (Aliphatic hydrocarbon solvents and aromatic solvents) In this embodiment, bismuth (meth)acrylate or bismuth subsalicylate and a phosphate ester are preferably reacted by stirring and mixing in an aliphatic hydrocarbon solvent or an aromatic solvent. Since water is generated in the reaction system during this reaction, it is preferable to dehydrate the generated water. To facilitate dehydration of the generated water, it is preferable to use an aliphatic hydrocarbon solvent or aromatic solvent having a high boiling point, specifically a boiling point of 100°C or higher. An aliphatic hydrocarbon solvent and an aromatic solvent can also be mixed and used as a mixed solution.

[0061] Examples of the aliphatic hydrocarbon solvent or aromatic solvent include hexane, heptane, nonane, decane, undecane, dodecane, xylene, dimethoxybenzene, benzene, toluene, chlorobenzene, bromobenzene, anisole, petroleum ether, petroleum benzine, and benzoin.

[0062] The amount of the aliphatic hydrocarbon solvent or aromatic solvent used is not particularly limited as long as it is an amount that allows the bismuth (meth)acrylate or bismuth subsalicylate and the phosphate ester to be sufficiently mixed. In particular, in consideration of the productivity of the phosphate ester-bonded bismuth compound, it is preferable to use the aliphatic hydrocarbon solvent and aromatic solvent in a ratio of 5 to 100 mL in total per 1 g of bismuth (meth)acrylate and bismuth subsalicylate.

[0063] (Reaction conditions) In this embodiment, the method for introducing bismuth (meth)acrylate or bismuth subsalicylate and a phosphate ester into a reaction system is not particularly limited. For example, a method can be employed in which bismuth subsalicylate, optionally diluted with an aliphatic hydrocarbon solvent or aromatic solvent, and a phosphate ester, optionally diluted with an aliphatic hydrocarbon solvent or aromatic solvent, are added to the reaction system together and stirred and mixed. Alternatively, a method can be employed in which an aliphatic hydrocarbon solvent or aromatic solvent is first introduced into the reaction system, and then bismuth subsalicylate, optionally diluted with an aliphatic hydrocarbon solvent or aromatic solvent, and a phosphate ester, optionally diluted with an aliphatic hydrocarbon solvent or aromatic solvent, are added together and stirred and mixed. Alternatively, a method can be employed in which one component is first introduced into the reaction system, and then the other component is introduced into the reaction system and stirred and mixed. Among these, the following method is preferred to reduce the coloration of the resulting phosphate ester-bonded bismuth compound and improve productivity. First, bismuth subsalicylate is dispersed in an aliphatic hydrocarbon solvent or aromatic solvent. At this time, bismuth subsalicylate may not dissolve, in which case it is preferable to pulverize the lumps of bismuth subsalicylate using an ultrasonic device or the like so that no lumps remain. Thereafter, the phosphate ester is added to the cloudy solution in which the bismuth subsalicylate has been dispersed, and stirring and heating are commenced.

[0064] The temperature (reaction temperature) at which the components are stirred may be the reflux temperature of the aliphatic hydrocarbon solvent or aromatic solvent. However, to further reduce coloration of the resulting phosphate ester-bonded bismuth compound, the reaction is preferably carried out at an oil bath temperature of 30 to 150°C, more preferably 40 to 140°C, and even more preferably 45 to 120°C.

[0065] Furthermore, when the reaction temperature is 30 to 110°C, it is preferable to reduce the pressure in the reaction system to remove (dehydrate) the water generated in the reaction system. In this case, dehydration can be performed while mixing the bismuth subsalicylate and the phosphate ester, or after mixing the two. However, considering the efficiency of the reaction, it is preferable to mix the two and then dehydrate them while reacting.

[0066] The reaction time is not particularly limited and is usually 1 to 6 hours.

[0067] In consideration of operability, the atmosphere in which the reaction is carried out may be any of an air atmosphere, an inert gas atmosphere, and a dry air atmosphere, and in consideration of operability, the reaction is preferably carried out in an air atmosphere.

[0068] After the reaction under the above conditions, the resulting phosphate-bonded bismuth compound is concentrated by distilling off the solvent, and if any insoluble turbid components remain, it is desirable to separate them by filtration or centrifugation. Furthermore, a solvent that is soluble in the reaction solvent used but does not dissolve the phosphate-bonded bismuth compound is added to the concentrated reaction solution obtained by this treatment to perform reprecipitation and purification. If any high-boiling point solvent remains, the above-mentioned decantation operation is repeated to replace the solvent. The remaining solvent is then distilled off and the resulting mixture is vacuum dried, allowing the phosphate-bonded bismuth compound to be isolated.

[0069] <Nitrile compounds> The nitrile compound is not particularly limited as long as it is a compound having a radical polymerizable carbon-carbon double bond and a nitrile group. Examples of the nitrile compound include acrylonitrile, methacrylonitrile, crotononitrile, 2-chloroacrylonitrile, 2-cyanoethyl acrylate, allyl cyanide, allyl cyanoacetate, fumaronitrile, and 5-norbornene-2-carbonitrile. Among these, acrylonitrile and methacrylonitrile are preferred, and methacrylonitrile is more preferred.

[0070] Considering the X-ray blocking effect, dispersibility, coloration reduction effect, etc., the content of the nitrile compound is preferably 1 to 1,000 parts by mass, more preferably 2 to 500 parts by mass, and even more preferably 5 to 100 parts by mass, relative to 100 parts by mass of the phosphate ester-bonded bismuth compound.

[0071] <Other radical polymerizable monomers> The curable composition according to this embodiment preferably contains a compound having one radically polymerizable carbon-carbon double bond (hereinafter also referred to as a "monofunctional radically polymerizable monomer") that is different from the phosphate ester-bonded bismuth compound and the nitrile compound in order to improve mechanical properties, color tone, weather resistance, optical uniformity, mold releasability, etc. One type of monofunctional radically polymerizable monomer may be used alone, or two or more types may be used in combination.

[0072] Examples of the monofunctional radically polymerizable monomer include various commercially available monofunctional radically polymerizable monomers, such as (meth)acrylic derivatives such as acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, vinylpyridine, vinylpyrrolidone, phenyl methacrylate, benzyl methacrylate, and 2-phenoxyethyl methacrylate; styrene, methylstyrene, and structural isomers thereof; methoxystyrene and structural isomers thereof; styrene derivatives such as chlorostyrene and bromostyrene; and vinyl compounds.

[0073] The content of the monofunctional radically polymerizable monomer is preferably 0.2 to 500 parts by mass, more preferably 0.5 to 400 parts by mass, and even more preferably 1 to 300 parts by mass, relative to 100 parts by mass of the nitrile compound, taking into consideration the solubility in the phosphate ester-bonded bismuth compound, the viscosity after mixing, and the impact resistance, hardness, and thermal properties of the cured product after curing.

[0074] Furthermore, in order to further improve the mechanical properties of the cured product after curing, such as impact resistance, the curable composition according to this embodiment preferably further contains a compound having two or more radically polymerizable carbon-carbon double bonds (hereinafter also referred to as a "polyfunctional radically polymerizable monomer"). One type of polyfunctional radically polymerizable monomer may be used alone, or two or more types may be used in combination.

[0075] Commercially available polyfunctional radical polymerizable monomers can be used without limitation. Among them, those represented by the following formula (1) or (2) are preferably used, taking into consideration the solubility in the phosphate ester-bonded bismuth compound, the viscosity after mixing, the impact resistance of the cured product, etc.

[0076] [ka] (In the formula, l represents an integer of 7 to 14.)

[0077] [ka] (In the formula, n and m each independently represent an integer of 1 to 15, and n+m=2 to 30.)

[0078] Furthermore, in order to improve the properties of the cured body, such as the surface hardness, it is preferable to use a compound represented by the following formula (7) in addition to the compound represented by the above formula (1) or (2).

[0079] [ka] (In the formula, p represents an integer of 1 to 5.)

[0080] Considering the solubility in the phosphate ester-bonded bismuth compound, the viscosity after mixing, and the impact resistance, hardness, and thermal properties of the cured product after curing, the content of the polyfunctional radically polymerizable monomer is preferably 10 to 500 parts by mass, more preferably 15 to 300 parts by mass, and even more preferably 20 to 250 parts by mass, per 100 parts by mass of the nitrile compound.

[0081] <Photochromic compounds> The curable composition according to the present embodiment may contain a photochromic compound to impart photochromic properties to the resulting cured product. A plurality of types of photochromic compounds may be appropriately mixed and used to obtain a desired color tone.

[0082] As the photochromic compound, known photochromic compounds such as fulgimide compounds, spirooxazine compounds, chromene compounds, etc. can be used without any limitation. Among them, chromene-based photochromic compounds are particularly suitable for use because they have higher durability of photochromic properties than other photochromic compounds and are superior in color development density and color fading speed of the photochromic properties than other photochromic compounds.

[0083] In addition to the compounds used in the examples, the following compounds can be exemplified as chromene-based photochromic compounds, but the compounds are not limited to these.

[0084] [ka]

[0085] [ka]

[0086] [ka]

[0087] When the curable composition according to the present embodiment contains a photochromic compound, the content thereof is preferably 0.005 to 20 parts by mass, more preferably 0.01 to 15 parts by mass, and even more preferably 0.02 to 10 parts by mass, relative to 100 parts by mass of the curable composition. By setting the content within such a range, it becomes easy to uniformly dissolve the photochromic compound in the curable composition while obtaining a sufficient color density, and therefore it becomes easy to obtain a sufficient and uniform color density.

[0088] <Other compounding agents> The curable composition according to the present embodiment may contain known compounding agents other than those described above, provided that the effects of the present invention are not impaired. Examples of such compounding agents include a radical polymerization initiator, an antioxidant, a stabilizer, a release agent for improving mold releasability, a dye for adjusting the color tone of the cured product, and a chain transfer agent for controlling polymerization.

[0089] The content of each compounding agent is preferably 0 to 30 parts by mass, more preferably 0.01 to 20 parts by mass, and even more preferably 0.02 to 15 parts by mass, relative to 100 parts by mass of the curable composition.

[0090] The curable composition according to this embodiment can be produced by mixing the above-described components by a known method.

[0091] <Photochromic curable composition> The photochromic curable composition according to this embodiment contains a photochromic compound and a curable compound.

[0092] <Photochromic compounds> As in the curable composition according to this embodiment, known photochromic compounds such as fulgimide compounds, spirooxazine compounds, and chromene compounds can be used as the photochromic compound without any restrictions.

[0093] Considering the photochromic properties such as the color density and fading speed of the resulting cured product, the content of the photochromic compound is preferably 0.1 to 20 parts by mass per 100 parts by mass of the photochromic curable composition excluding the photochromic compound, and more preferably 2 to 10 parts by mass per 100 parts by mass of the photochromic curable composition excluding the photochromic compound in order to exhibit better photochromic properties.

[0094] <Curable compound> As the curable compound, known curable compounds can be used. Specific examples of the curable compound include trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethane trimethacrylate, tetramethylolmethane triacrylate, tetramethylolmethane tetramethacrylate, tetramethylolmethane tetraacrylate, trimethylolpropane triethylene glycol trimethacrylate, trimethylolpropane triethylene glycol triacrylate, ditrimethylolpropane tetramethacrylate, ditrimethylolpropane Pantetraacrylate, dipentaerythritol hexaacrylate, bisphenol A dimethacrylate, 2,2-bis(4-methacryloyloxyethoxyphenyl)propane, 2,2-bis(4-methacryloyloxypolyethylene glycol phenyl)propane with an average molecular weight of 776, 2,2-bis(4-methacryloyloxypolyethylene glycol phenyl)propane with an average molecular weight of 804, 2,2-bis(4-acryloyloxypolyethylene glycol phenyl)propane with an average molecular weight of 776, methacryloyloxypolyethylene glycol phenyl)propane with an average molecular weight of 468 Polyethylene glycol methacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, pentaethylene glycol dimethacrylate, pentapropylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, pentaethylene glycol diacrylate, tripropylene glycol diacrylate, tetrapropylene glycol diacrylate, pentapropylene glycol diacrylate, polyethylene glycol dimethacrylate with an average molecular weight of 330, polyethylene glycol dimethacrylate with an average molecular weight of 536, polytetramethylene glycol dimethacrylate with an average molecular weight of 736, tripropylene glycol dimethacrylate, tetrapropylene glycol dimethacrylate, polypropylene glycol dimethacrylate with an average molecular weight of 536, polyethylene glycol diacrylate with an average molecular weight of 258, polyethylene glycol diacrylate with an average molecular weight of 308,Polyethylene glycol diacrylate having an average molecular weight of 532, polyethylene glycol diacrylate having an average molecular weight of 708, polycarbonate di(meth)acrylate which is a reaction product of polycarbonate diol and (meth)acrylic acid, multifunctional urethane (meth)acrylate (urethane oligomer tetraacrylate, urethane oligomer hexamethacrylate, urethane oligomer hexaacrylate, etc.), multifunctional polyester (meth)acrylate (polyester oligomer hexaacrylate, etc.), polyol having a (meth)acryloyl group and having ketones, Silsesquioxane monomers with various structures such as architechture, ladder structure, and random structure, glycidyl acrylate, glycidyl methacrylate, β-methylglycidyl methacrylate, bisphenol A monoglycidyl ether methacrylate, 4-glycidyloxy methacrylate, 3-(glycidyl-2-oxyethoxy)-2-hydroxypropyl methacrylate, 3-(glycidyloxy-1-isopropyloxy)-2-hydroxypropyl acrylate, 3-glycidyloxy-2-hydroxypropyloxy)-2-hydroxypropyl acrylate, glycidyloxy polyethylene glycol methacrylate with an average molecular weight of 540 (the main component is in the molecular weight range of 390 to 660), γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltriethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, (3-acryloyloxypropyl)dimethylmethoxysilane, (3-acryloyloxypropyl)methyldimethoxysilane, (3-acryloyloxypropyl)trimethoxysilane, 3-(N-allylamino)propyltrimethacrylate silane, allyldimethoxysilane, allyltriethoxysilane, allyltrimethoxysilane, 3-aminophenoxydimethylvinylsilane, 4-aminophenoxydimethylvinylsilane, 3-(3-aminopropoxy)-3,3-dimethyl-1-propenyltrimethoxysilane, butenyltriethoxysilane, 2-(chloromethyl)allyltrimethoxysilane, diethoxyvinylsilane, 1,3-divinyltetraethoxydisiloxane, docosenyltriethoxysilane, O-(methacryloxyethyl)-N-(triethoxysilylpropyl)urethane,N-(3-methacryloxy-2-hydroxypropyl)-3-aminopropyltriethoxysilane, methacryloyloxyethoxytrimethylsilane, (methacryloxymethyl)dimethylethoxysilane, methacryloyloxymethyltriethoxysilane, methacryloyloxymethyltrimethoxysilane, methacryloyloxypropyldimethylethoxysilane, methacryloyloxypropyldimethylmethoxysilane, methacryloyloxypropyltris(methoxyethoxy)silane, 7-octenyltrimethoxysilane, 1,3-bis(methacryloyloxy)-2-trimethylsiloxypropane, tetrakis(2-methacryloyloxyethoxy)silane, trivinylethoxysilane, trivinylmethoxysilane, vinyldimethylsilane Examples of the vinyl silane include vinylethoxysilane, vinyldiphenylethoxysilane, vinylmethyldiacetoxysilane, vinylmethyldiethoxysilane, vinylmethyldimethoxysilane, O-(vinyloxyethyl)-N-(triethoxysilylpropyl)urethane, vinyloxytrimethylsilane, vinylphenyldiethoxysilane, vinylphenylmethylmethoxysilane, vinyltriacetoxysilane, vinyltri-t-butoxysilane, vinyltriethoxysilane, vinyltriisopropenoxysilane, vinyltriisopropoxysilane, vinyltrimethoxysilane, vinyltriphenoxysilane, vinyltris(2-methoxyethoxy)silane, 2-isocyanatoethoxymethacrylate, and 4-(2-isocyanatoisopropyl)styrene.

[0095] <Other compounding agents> The photochromic curable composition according to this embodiment may contain known compounding agents other than those described above, provided that the effects of the present invention are not impaired. Examples of such compounding agents include a radical polymerization initiator, an antioxidant, a stabilizer, a release agent for improving mold releasability, a dye for adjusting the color tone of the cured product, and a chain transfer agent for controlling polymerization.

[0096] The content of each compounding ingredient is preferably 0 to 30 parts by mass, more preferably 0.01 to 20 parts by mass, and even more preferably 0.02 to 15 parts by mass, relative to 100 parts by mass of the photochromic curable composition.

[0097] The photochromic curable composition according to this embodiment can be produced by mixing the above-mentioned components by a known method.

[0098] <Cured body and laminate> The cured product according to this embodiment is obtained by curing the curable composition according to this embodiment. The laminate according to this embodiment is obtained by laminating this cured product and a cured product obtained by curing the photochromic curable composition according to this embodiment.

[0099] The method for producing the cured product is not particularly limited, and known polymerization methods such as photopolymerization, thermal polymerization, etc. can be used. The suitable polymerization method is determined by factors such as the radical polymerization initiator that is blended into the curable composition as needed.

[0100] The method for producing the laminate is not particularly limited, but a suitable method is to produce a cured product by curing the curable composition according to this embodiment, and then apply the photochromic curable composition according to this embodiment to the surface of the cured product by spin coating, dipping, etc., and then cure it by UV irradiation, heating, etc. In this case, another layer may be provided between the cured product obtained by curing the curable composition according to this embodiment and the cured product obtained by curing the photochromic curable composition according to this embodiment, or another layer may be provided on the laminate.

[0101] [Physical properties of cured body and laminate] The cured product and laminate according to this embodiment contain a high concentration of bismuth, which has a high X-ray blocking ability, yet have high transmittance and little coloring. The cured product according to this embodiment can have a thickness of, for example, 2 mm, a transmittance of 80% or more at a wavelength of 560 nm, an X-ray blocking ability equivalent to or greater than 0.02 mm of lead foil, and a yellowness index of 45 or less. Furthermore, the cured product according to this embodiment can contain 5 to 40 mass% of the bismuth component relative to the total mass of the cured product.

[0102] [Photochromic properties of cured body and laminate] Indicators of photochromic properties when a photochromic compound is used include: 1) the maximum absorption wavelength (λmax), which is the wavelength with the greatest light absorption before and after coloring, and the color tone related to the absorption spectrum; 2) the color density {ε(120)-ε(0)}, which is the difference between the absorbance {ε(120)} after 120 seconds of light irradiation at the maximum absorption wavelength and the absorbance {ε(0)} before light irradiation; and 3) the fading rate [t1 / 2 (sec.)], which is the time required for the absorbance at the maximum absorption wavelength of the sample to decrease to half of {ε(120)-ε(0)} when the light irradiation is stopped after 120 seconds of light irradiation.

[0103] The maximum absorption wavelength and color tone of 1) above may be adjusted appropriately depending on the type and amount of the photochromic compound used. The color density of 2) above is preferably 0.2 to 1.2, more preferably 0.3 to 1.1, since too strong a color density can significantly reduce visibility. The fading speed of 3) above may be selected based on the environment of use and personal preference; for example, for eyeglass applications, a faster fading speed is preferred.

[0104] [Uses of cured products and laminates] The cured product and laminate according to this embodiment use a bismuth compound instead of lead, and therefore are highly safe, have sufficient radiation-blocking ability, are reduced in coloration, are highly transparent as optical materials, and have practical mechanical properties. Therefore, the cured product and laminate according to this embodiment can be suitably used as a radiation protection material in X-ray protective eyeglass lenses, shielding materials, screens, peepholes, and the like for medical applications. Furthermore, when a photochromic compound is used, they also have the ability to block light, including ultraviolet light, such as sunlight, and are therefore particularly suitable for use outdoors. [Example]

[0105] The present invention will be described in detail below using examples and comparative examples, but the present invention is not limited to the following examples.

[0106] The analytical and measurement methods used in this example are as follows.

[0107] <Analysis method for phosphate ester-bound bismuth compounds> IR measurement A Fourier transform infrared spectrophotometer (Spectrum One, manufactured by PerkinElmer) was used. Measurements were performed using the single reflection ATR method with four-times integration.

[0108] TG-DTA measurement A thermogravimetric and differential thermal analyzer (TG8120, manufactured by Rigaku Corporation) was used. Temperature was scanned from room temperature to 500°C at a heating rate of 10°C / min under an air flow.

[0109] Raman scattering measurement A micro-Raman spectrometer (NRS-7100, manufactured by JASCO Corporation) was used. The sample was excited using a 532 nm laser, a 100x objective lens, a 600 line / mm grating, and apertures of φ25 μm and φ4000 μm, with an exposure time of 20 seconds x 2.

[0110] · 1 H-, 31 P-NMR measurement A nuclear magnetic resonance spectrometer (JNM-ECA400II, manufactured by JEOL RESONANCE Co., Ltd.) was used. Deuterated acetone was used as the solvent, and the measurement was performed at a sample concentration of 1% by mass.

[0111] XPS measurement An X-ray photoelectron spectrometer (ULVAC-PHI, Inc., ESCA5701ci / MC) was used. The X-ray source was monochromated Al-Kα (14kV-330W). The aperture diameter was φ800μm and the photoelectron take-off angle was 45°. The sample was crushed in an agate mortar, and the resulting powder was fixed to a substrate with carbon tape, introduced into the measurement chamber, and measured.

[0112] MALDI-TOF-MS (matrix-assisted laser desorption / ionization time-of-flight mass spectrometry) measurement A Bruker Rapide ® TOF / TOF spectrometer was used. The matrices used were CHCA (α-cyano-4-hydroxycinnamic acid), DIT (Dithranol), and DHB (2,5-Dihydroxybenzoic acid), and the cationizing agent was sodium trifluoroacetate. Measurements were performed in Reflector / Positive mode, with a mass range of m / z 20–4000.

[0113] <Measurement of Viscosity of Curable Composition> The viscosity of the curable composition was measured by measuring the kinematic viscosity at 25°C using a Cannon-Fenske viscometer and multiplying it by the density. Alternatively, the viscosity was measured at 25°C using an E-type viscometer (Brookfield Rheometer RST).

[0114] <Measurement of physical properties of cured body and laminate> The curable composition was thermally polymerized to prepare a cured product (plate) having a thickness of 2 mm, and the physical properties were measured as follows.

[0115] Radiation (X-ray) blocking ability The X-ray blocking ability of the resulting cured materials was evaluated as follows. First, the transmitted X-ray dose was measured according to JIS T 61331-1, "Protective equipment for diagnostic X-rays - Part 1: Method for determining the attenuation characteristics of materials." The X-ray device used was an MG-45 model manufactured by Yxlon International. The X-ray tube voltage was 120 kV, the tube current was 12.5 mA, and a 2.5 mm Al filter plate was used. The distance from the X-ray tube focus to the sample was 600 mm, and the distance from the sample to the measuring device was 900 mm. The measuring device used was an ionization chamber exposure dose rate meter (RAMTEC-Solo A4 probe manufactured by Toyo Medic Co., Ltd.). The X-ray blocking ability was evaluated as the lead equivalent (mmPb), which is the thickness (mm) of the corresponding lead plate.

[0116] Impact resistance A ball drop test was conducted to evaluate the impact resistance of the resulting cured specimen. A plate of the cured specimen was placed on a 3mm-thick NBR support ring of the same diameter, bonded to a tube with an inner diameter of 25mm, an outer diameter of 32mm, and a height of 25mm. Steel balls weighing 4.5g, 6.9g, 14g, 16g, 32g, 50g, 67g, 80g, 95g, 112g, 130g, 151g, 174g, 198g, 225g, and 261g were dropped from a height of 1.27m using an electromagnet drop device, in order of decreasing weight. The weight of the steel ball before the specimen cracked or broke was recorded as the maximum impact resistance.

[0117] ·Surface hardness The surface hardness of the hardened body was measured using an Akashi Rockwell hardness tester AR-10.

[0118] Photochromic properties The xenon lamp L-2480 (300W) SHL-100 manufactured by Hamamatsu Photonics K.K. was used through an Aeromass filter (manufactured by Corning) at 20°C ± 1°C, with a beam intensity of 365 nm = 2.4 mW / cm on the surface of the cured body or laminate. 2 , 245nm=24μW / cm 2 The photochromic properties of the cured product or laminate were evaluated by the following method.

[0119] [1-1] Maximum absorption wavelength (λmax): This is the maximum absorption wavelength after color development, determined using a spectrophotometer (instant multichannel photodetector MCPD1000) manufactured by Otsuka Electronics Co., Ltd. This value is related to the color tone at the time of color development. [1-2] Color Tone: The color was developed outdoors, and the developed color tone was evaluated visually. [2] Color density {ε(120)-ε(0)}: The difference between the absorbance {ε(120)} after 120 seconds of light irradiation and the absorbance {ε(0)} before light irradiation at the maximum absorption wavelength was taken as the color density. [3] Fading speed [t1 / 2(sec.)]: After 120 seconds of light irradiation at the maximum absorption wavelength, the time required for the absorbance of the sample at the maximum absorption wavelength to decrease to half of {ε(120) - ε(0)} when the light irradiation was stopped was defined as the fading rate.

[0120] The preparation methods and abbreviations of the compounds used in the examples are as follows:

[0121] (1) Phosphate-bonded bismuth compounds A phosphate-bonded bismuth compound was prepared by the following method. 94.27 g of bismuth(III) subsalicylate (Sigma-Aldrich, 260.35 mmol in terms of bismuth), 33.06 g of a mixture of bis[(2-methacryloyloxyethyl)]phosphate and (2-methacryloyloxyethyl)phosphate (Daihachi Chemical Industry Co., Ltd., MR-200, 162.04 mmol as a phosphoric acid value), 33.09 g of diphenyl-2-methacryloyloxyethyl phosphate (Daihachi Chemical Industry Co., Ltd., MR-260, 91.33 mmol), and 6.17 g of dibutylhydroxytoluene (BHT, Fujifilm Wako Pure Chemical Industries, Ltd., special grade reagent) as a polymerization inhibitor were placed in a 1000 mL eggplant-shaped flask, and 750 mL of toluene was added. The mixture was ultrasonically dispersed using a bath-type sonicator to produce a cloudy solution.

[0122] The resulting cloudy solution was transferred to a 1000 mL four-neck flask equipped with a Dean-Stark trap, and the reaction was carried out with stirring at 130 °C in an oil bath. The generated water was removed from the system. The reaction was terminated when no more water was generated. A slight amount of a pale yellow precipitate formed, resulting in a scattered pale yellow solution.

[0123] This solution was concentrated to 250 mL using a vacuum evaporator. 8 g of alumina powder was added, and the mixture was left overnight. It was then suction-filtered using 5B filter paper. 3 g of activated carbon (Norit, Darco G60) was added to the resulting pale yellow, scattered filtrate, and the mixture was centrifuged at 23,830 × g for 8 hours. The centrifuged supernatant was pressure-filtered through a 0.2 μm membrane filter, yielding a pale yellow, transparent filtrate. The solvent was removed from this solution using a vacuum evaporator, and the mixture was redissolved in 250 mL of acetone. 3 g of activated carbon (Norit, Norit SX-Plus) was added to the resulting pale yellow solution, and the mixture was centrifuged at 23,830 × g for 12 hours. The centrifuged supernatant was pressure-filtered through a 0.2 μm pore-size membrane filter, yielding a pale yellow, transparent filtrate. The resulting filtrate was concentrated to 100 mL using a vacuum evaporator. This acetone solution was poured into 800 mL of hexane placed in a 1000 mL conical beaker while stirring. The resulting white precipitate was collected by suction filtration using 5B filter paper, and the resulting solid was dried in vacuum. 64.40 g of a phosphate ester-bonded bismuth compound was obtained as a white powder. The synthesis was confirmed by the above method. 1 The structure of the obtained phosphate ester-bonded bismuth compound was that of the above formula (4), where b=u=v=w=0.6.

[0124] (2) Photochromic compounds PC1 [ka]

[0125] PC2 [ka]

[0126] PC3 [ka]

[0127] PC4 [ka]

[0128] (3) Radical polymerizable monomer (nitrile compounds) Acrylonitrile (Other radical polymerizable monomers) ·styrene BPE-100: Ethoxylated bisphenol A dimethacrylate (EO 2.6 mol) (Shin-Nakamura Chemical Co., Ltd.) BPE-500: Ethoxylated bisphenol A dimethacrylate (EO 10 mol) (Shin-Nakamura Chemical Co., Ltd.) C6DA: 1,6-hexanediol dimethacrylate (Fujifilm Wako Pure Chemical Industries, Ltd.) TMPT: Trimethylolpropane trimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) 9G: Nonaethylene glycol dimethacrylate (Shin-Nakamura Chemical Co., Ltd.) M1: 2,2-bis(4-methacryloyloxypolyethylene glycol phenyl)propane (average molecular weight 776) M2: Polyethylene glycol diacrylate (average molecular weight 532) M3: Trimethylolpropane trimethacrylate M4: Polyester oligomer hexaacrylate (Daicel Allnex Co., Ltd., EB-1830) M5: Glycidyl methacrylate M6: γ-Methacryloyloxypropyltrimethoxysilane

[0129] (4) Polymerization initiator 2,2'-Azobis(2,4-dimethylvaleronitrile) (V-65) IN1: 1-Hydroxycyclohexyl phenyl ketone IN2: Bis(2,6-trimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide

[0130] (5) Other compounding agents (light stabilizers) ·LS765: Bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate ·NMDEA: N-methyldiethanolamine

[0131] Example 1 A curable composition was obtained by adding 15 parts by weight of acrylonitrile and 15 parts by weight of styrene to 70 parts by weight of a phosphate ester-bonded bismuth compound (referred to as "bismuth compound" in the table) and dissolving them uniformly. The viscosity of this curable composition was 80 mPa·s, a viscosity suitable for bulk polymerization by casting. 0.6 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) (V-65) was added to this curable composition and completely dissolved. The curable composition was then placed under reduced pressure using a vacuum pump to remove dissolved oxygen. The curable composition was then poured into a 2 mm thick glass mold and polymerized at a maximum temperature of 90°C for 4 hours, yielding a pale yellow, transparent cured product. The thickness of the resulting cured product was 2.38 mm. The results are shown in Table 1.

[0132] <Comparative Example 1> The same procedure as in Example 1 was carried out, except that 70 parts by mass of the phosphate ester-bonded bismuth compound was added to 30 parts by mass of styrene and dissolved uniformly. The viscosity of the resulting curable composition was 400 mPa·s, which was too low for suitable bulk polymerization by casting. The resulting cured product was pale yellow and transparent. The results are shown in Table 1.

[0133] <Example 2> The same procedure as in Example 1 was carried out, except that 70 parts by mass of the phosphate ester-bonded bismuth compound was added to 30 parts by mass of acrylonitrile and dissolved uniformly. The viscosity of the resulting curable composition was 45 mPa·s, a viscosity suitable for bulk polymerization by casting. The resulting cured product was a deep orange, transparent product. The results are shown in Table 1.

[0134] Example 3 The same procedure as in Example 1 was carried out, except that 77 parts by mass of the phosphate ester-bonded bismuth compound was added to 11 parts by mass of acrylonitrile and 12 parts by mass of styrene and dissolved uniformly. The viscosity of the resulting curable composition was 150 mPa·s, which was suitable for bulk polymerization by casting, despite the high concentration of bismuth. The resulting cured product was pale yellow and transparent. The results are shown in Table 1.

[0135] <Comparative Example 2> An attempt was made to dissolve 77 parts by mass of the phosphate ester-bonded bismuth compound to a uniform solution by adding 23 parts by mass of styrene, but the mixture turned into a gel, and it was impossible to remove the air bubbles, making it impossible to measure the viscosity. Therefore, a cured product was not produced.

[0136] [Table 1]

[0137] As shown in Table 1, the curable composition containing a phosphate ester-bonded bismuth compound and a nitrile compound had a viscosity suitable for bulk polymerization by casting, but the viscosity of the two-component system containing a phosphate ester-bonded bismuth compound and styrene was not low enough.

[0138] <Examples 4 to 13> The same procedures as in Example 1 were carried out, except that the phosphate ester-bonded bismuth compound, acrylonitrile, and other radical polymerizable monomers were added and uniformly dissolved in the compositions shown in Table 2. The results are shown in Table 2.

[0139] [Table 2]

[0140] <Examples 14 to 28> A phosphate ester-bonded bismuth compound, methacrylonitrile, and other radically polymerizable monomers were added to the composition shown in Table 3, dissolved uniformly, and a ball drop test was carried out in the same manner as in Example 1, except that 0.3 parts by mass of methylstyrene dimer was added to adjust the polymerization rate. The results are shown in Table 3.

[0141] [Table 3]

[0142] As shown in Tables 2 and 3, Examples 4 to 28 had high impact resistance and surface hardness, with maximum impact resistance of 30 g or more and Rockwell hardness of 80 or more, and were suitable for use as protective glasses.

[0143] When a 120 keV X-ray blocking experiment was carried out on the cured bodies of Examples 1 to 28, the lead equivalent was found to be 0.12±0.04 mmPb.

[0144] Example 29: Photochromic laminate 70 parts by weight of a phosphate-bonded bismuth compound, 10 parts by weight of styrene, 10 parts by weight of acrylonitrile, and 10 parts by weight of nonaethylene glycol dimethacrylate (Shin-Nakamura Chemical Co., Ltd.) were homogeneously dissolved. 0.6 parts by weight of 2,2'-azobis(2,4-dimethylvaleronitrile) was added to the resulting composition and completely dissolved, yielding a curable composition. The curable composition was then placed under reduced pressure using a vacuum pump to remove dissolved oxygen. The curable composition was then injected between two 7 cm diameter circular glass molds secured together with adhesive tape, with the gap adjusted to a 2 mm thickness. Polymerization was carried out at a maximum temperature of 90°C for 4 hours, yielding a pale yellow, transparent cured product. The resulting cured product had a thickness of 2.01 mm.

[0145] Meanwhile, a photochromic curable composition was prepared as follows. The polymerizable compounds were adjusted to a mass ratio of M1:M2:M3:M4:M5:M6 = 43:15:15:10:10:7. To 100 parts by mass of the polymerizable compounds, 1.2 parts by mass of photochromic compounds PC1, 0.4 parts by mass of PC2, and 1.2 parts by mass of PC3 were added. Also, 0.375 parts by mass of polymerization initiator IN1 and 0.125 parts by mass of IN2 were added. Other compounding ingredients included 5 parts by mass of the light stabilizer LS765 and 3 parts by mass of NMDEA. The mixture was thoroughly mixed to obtain a photochromic curable composition. The viscosity of this photochromic curable composition was measured at 25°C using an E-type viscometer and found to be 120 mPa·s, a viscosity suitable for spin coating.

[0146] Next, 2 g of the photochromic curable composition obtained by the above method was spin-coated onto the surface of the above cured product using a MIKASA spin coater 1H-DX2. The spin-coating conditions were adjusted so that the thickness of the photochromic cured product obtained after curing of the photochromic curable composition would be 40±1 μm. Next, the cured product with the photochromic curable composition spin-coated onto its surface was spin-coated in a nitrogen gas atmosphere with an output of 200 mW / cm at a wavelength of 405 nm on the cured product surface. 2 The photochromic curable composition was cured by irradiating it with light for 90 seconds using an F3000SQ equipped with a D bulb manufactured by Fusion UV Systems, Inc., adjusted so that the photochromic curable composition was cured. Thereafter, a heat treatment was carried out for 1 hour in an incubator at 100°C, thereby obtaining a laminate.

[0147] The radiation (X-ray) blocking ability of the obtained laminate was 0.10±0.04 mmPb (lead equivalent). The photochromic properties were as follows: maximum absorption wavelength 588 nm, color density 0.9, color tone dark brown, and fading speed 62 seconds.

[0148] Example 30: Cured product containing photochromic compound 70 parts by weight of a phosphate-bonded bismuth compound, 9 parts by weight of styrene, 9 parts by weight of acrylonitrile, and 12 parts by weight of nonaethylene glycol dimethacrylate (Shin-Nakamura Chemical Co., Ltd.) were added and dissolved uniformly. To 100 parts by weight of the resulting composition, 0.017 parts by weight of photochromic compounds PC1, 0.01275 parts by weight of PC2, 0.034 parts by weight of PC3, and 0.00425 parts by weight of PC4 were added, followed by dissolution with 0.4 parts by weight of 2,2'-azobis(isobutyric acid), yielding a curable composition containing the photochromic compounds. This curable composition was then placed under reduced pressure using a vacuum pump to remove dissolved oxygen. The curable composition was then poured between two 7 cm diameter circular glass molds, each with a 2 mm gap, secured together with adhesive tape. Polymerization was carried out at a maximum temperature of 90°C for 4 hours. After release from the mold, the mixture was annealed at 100°C for 2 hours to yield a brown, transparent cured product. The thickness of the resulting cured body was 2.03 mm.

[0149] The radiation (X-ray) blocking ability of the obtained cured material was 0.10±0.04mmPb (lead equivalent).The photochromic properties were as follows: maximum absorption wavelength 598nm, color density 0.45, color tone dark brown, and fading speed 74sec.

Claims

1. A curable composition containing a bismuth compound in which a phosphate ester having a (meth)acryloyl group is bonded to the bismuth, and a nitrile compound having a radical polymerizable carbon-carbon double bond, The bismuth compound is a compound represented by the following formula (4): the nitrile compound is at least one selected from acrylonitrile and methacrylonitrile, the content of the bismuth compound is 15 to 85 mass% based on the total amount of the curable composition, The content of the nitrile compound is 5 to 100 parts by mass per 100 parts by mass of the bismuth compound. 【Chemistry 1】 (In the formula, each R independently represents a hydrogen atom or a methyl group, 2b+u+v+w=3, b:(u+v+w)=1:0.2-20, and u:v:w=1:0.2-5:0.4-10.)

2. The curable composition according to claim 1, further comprising a compound having one radically polymerizable carbon-carbon double bond, which is different from the bismuth compound and the nitrile compound.

3. The following formula (1): 【Chemistry 2】 (In the formula, l represents an integer of 7 to 14.) and a compound represented by the following formula (2): 【Transformation 3】 (In the formula, n and m each independently represent an integer of 1 to 15, and n+m=2 to 30.) The curable composition according to claim 1 or 2, further comprising at least one compound selected from the group consisting of compounds represented by the formula:

4. The curable composition according to any one of claims 1 to 3, further comprising a photochromic compound.

5. A cured product obtained by curing the curable composition according to any one of claims 1 to 4.

6. A laminate comprising a cured product obtained by curing the curable composition according to any one of claims 1 to 3 and a cured product obtained by curing a photochromic curable composition containing a photochromic compound.

7. A radiation protection material comprising the cured product according to claim 5 or the laminate according to claim 6.

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