Method for producing X-ray-aspiratory polymers

Abstract

To provide a novel method for producing iodine-containing polymers. [Solution] A method for producing an iodine-containing polymer, comprising polymerizing a photopolymerizable composition containing a radical polymerizable compound (A), an iodized monocyclic aromatic compound (B) which may have substituents, and a photopolymerization initiator (C).

Description

[Technical Field]

[0001] This disclosure relates to a method for producing an iodine-containing polymer and an iodine-containing polymer, and more particularly to a method for producing an X-ray-absorbing resin and an X-ray-absorbing resin. [Background technology]

[0002] Originally, resins transmit X-rays almost entirely and do not absorb them. Resins with X-ray absorbing properties are extremely useful for X-ray inspection of resin molded objects, calibration of X-ray inspection equipment, and sensitivity amplification of resists for extreme ultraviolet (EUV) exposure. To give a resin the ability to absorb X-rays, it is necessary to include X-ray absorbing elements such as iodine atoms in the resin. However, if X-ray absorbing elements are physically mixed into the polymerized resin, there are safety concerns for the environment and human health if iodine is released outside the polymer. On the other hand, a method of polymerizing a polymer while chemically bonding X-ray absorbing elements into the polymer is difficult because elements with high X-ray absorption efficiency tend to inhibit polymerization, but it has been attempted in several prior arts.

[0003] Non-patent document 1 investigates the photopolymerization of iodobenzene (IB2) and triethylamine (TEA) systems, which are known to dissociate into iodine atoms and phenyl radicals upon light irradiation. While decomposing the iodine compound with ultraviolet light to generate iodine radicals and compound-derived radicals, Similarly, the initiator, which is also decomposed by ultraviolet light, extracts iodine that has not yet been removed from the iodine compound, rapidly increasing the number of radicals.

[0004] Non-patent document 2 discloses an iodine transfer polymerization method. Specifically, monomer addition continues to the radical of the iodine compound residue generated when iodine is removed from the carbon-iodine bond of the iodine compound, and then iodine is radically abstracted from other molecules, causing a chain transfer reaction. When the chain stops, the carbon-iodine bond at the end of the polymer is radically active, and when that iodine is abstracted, monomer addition can occur again on the resulting polymer radical. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Sakai, Photopolymerization of methyl methacrylate by iodine-amine system, Osaka University, Doctoral dissertation abstract, 1975 [Retrieved November 15, 2024], Internet https: / / hdl.handle.net / 11094 / 31301 [Non-Patent Document 2] Journal of Polymer Science, Vol. 49, No. 10, pp. 765-783 (Oct 1992), [Retrieved November 15, 2024], Internet: https: / / www.jstage.jst.go.jp / article / koron1974 / 49 / 10 / 49_10_765 / _article / -char / ja / [Overview of the project] [Problems that the invention aims to solve]

[0006] Non-patent document 1 includes a polymer amine as an initiator, but it is thought that solution polymerization is performed to increase the reaction rate because the polymerization reaction derived from the compound radical separated by the initiator is slow.

[0007] Non-patent document 2 uses iodine compounds that decompose with light, such as (CF3)2CFI and I(CF2)4I, so polymerization can occur even without a photoinitiator. However, since the rate at which iodine separates with light is quite slow, it is thought that solution polymerization is performed to increase the reaction rate.

[0008] Conventional chemical bonding methods are unsuitable for practical applications such as lithography, 3D printing, and medical applications, and have not been put into practical use, due to their slow reaction rates under fast reaction, solvent-free (without solvents) and catalyst-free (without catalysts) conditions, the presence of many impurities, and the complexity of the reaction process.

[0009] One of the problems to be solved in the present disclosure is to provide a method for producing an iodine-containing polymer that can be polymerized even by bulk polymerization.

Means for Solving the Problems

[0010] The present disclosure includes, for example, the subject matters described below.

[0011] Item 1. A method for producing an iodine-containing polymer, comprising polymerizing a photopolymerizable composition containing a radically polymerizable compound (A), an iodinated monocyclic aromatic compound (B) which may have a substituent, and a photopolymerization initiator (C).

[0012] Item 2. The production method according to Item 1, wherein the polymerization of the photopolymerizable composition includes bulk polymerization.

[0013] Item 3. The method according to Item 1 or 2, wherein the radically polymerizable compound (A) includes a compound having at least one ethylenically unsaturated bond.

[0014] Item 4. The production method according to any one of Items 1 to 3, wherein the iodinated monocyclic aromatic compound (B) which may have a substituent is asymmetric.

[0015] Item 5. The production method according to any one of Items 1 to 4, wherein the iodine-containing polymer is an X-ray contrast resin.

[0016] Item 6. A photopolymerizable composition containing a radically polymerizable compound (A), an iodinated monocyclic aromatic compound (B) which may have a substituent, and a photopolymerization initiator (C).

[0017] Item 7. An iodine-containing polymer which is a cured product of the photopolymerizable composition according to Item 6.

[0018] Item 8. A structural unit derived from a radically polymerizable compound (A), and A structural unit having a monocyclic aromatic ring derived from an iodinated monocyclic aromatic compound (B) which may have a substituent and is bonded to one end of a structural unit derived from the radical-polymerizable compound (A), An iodine-containing polymer which is a cured product of the photopolymerizable composition according to Item 6 and has iodine bonded to another end of a structural unit derived from the radical-polymerizable compound (A).

[0019] Item 9. The iodine-containing polymer according to Item 8, in which adjacent structural units derived from the radical-polymerizable compound (A) are crosslinked.

[0020] Item 10. An iodine-containing polymer containing a plurality of the iodine-containing polymers according to Item 8, in which one iodine-containing polymer among the plurality of iodine-containing polymers and another iodine-containing polymer among the plurality of iodine-containing polymers are crosslinked.

[0021] Item 11. An iodine-containing polymer represented by the following formula (I).

[0022]

Chemical formula

[0023] (In formula (I), R 1 、R 4 、and R 7 each independently represent a hydrocarbon group having 1 to 40 carbon atoms which may have a substituent or a group in which a part of the carbon atoms of the hydrocarbon group is substituted with an oxygen atom or a nitrogen atom, and R 1 and R 4 、and / or R 4 and R 7 may be crosslinked via an alkylene group, R 2 、R 5 、and R 8 each independently represent a hydrogen atom or a methyl group, R 3 、R 6 、and R9 Each of these independently represents a hydrogen atom or a methyl group. l, m, and n are 0 or integers greater than or equal to 1, except when l, m, and n are all 0. Section 12. A method for inspecting an article containing an iodine-containing polymer, comprising inspecting the article, which is made of an iodine-containing polymer as described in any of paragraphs 7 to 11, using X-rays. [Effects of the Invention]

[0024] According to this disclosure, iodine-containing polymers can be produced using radical polymerization without the use of solvents. [Brief explanation of the drawing]

[0025] [Figure 1] A photograph of a liquid mixture of HDDA, diiodobenzene, and Omnirad369 in a glass container. [Figure 2] Image of the cured product at 49 keV. The rightmost part is the polymer obtained by curing the mixture prepared in Example 1 under the conditions of Example 2. [Figure 3] Image of the cured product at 100 keV. The rightmost image shows the polymer obtained by curing the mixture prepared in Example 1 under the conditions of Example 2. [Figure 4] A photograph of iodine resin transferred onto a PET film. [Figure 5] (A) SEM image of the dot pattern portion of the iodine resin transfer, (B) Optical microscope image of the line portion of the iodine resin transfer. [Figure 6] A standard resin transfer print (left half) and an iodine resin transfer print (right half) within the same photograph. [Figure 7] A molded object created with a 3D printer. [Modes for carrying out the invention]

[0026] In this specification, "contains" is a concept that also includes "substantially consists only of" and "consists only of."

[0027] In this specification, weight may be used interchangeably with mass.

[0028] In this specification, numbers connected by "~" represent a numerical range that includes the numbers before and after "~" as the lower and upper limits, respectively.

[0029] In the numerical ranges described stepwise in this specification, the upper or lower limit of a numerical range in one step can be arbitrarily combined with the upper or lower limit of a numerical range in another step. Furthermore, in the numerical ranges described in this specification, the upper or lower limit of a numerical range may be replaced with a value shown in the example or a value that can be uniquely derived from the example.

[0030] In this specification, "(meth)acrylic" means acrylic, methacrylic, or both; "(meth)acrylate" means acrylate, methacrylate, or both; and "(meth)acryloyloxy" means acryloyloxy, methacroyloxy, or both.

[0031] In this specification, "bulk polymerization" refers to a polymerization method that does not use a solvent.

[0032] The embodiments included in this disclosure will be described further below. The embodiments described below are examples of typical embodiments of this disclosure and do not limit the scope of the invention.

[0033] This disclosure provides a method for producing an iodine-containing polymer, comprising polymerizing a photopolymerizable composition containing a radical polymerizable compound (A), an optionally substituted iodized monocyclic aromatic compound (B), and a photopolymerization initiator (C).

[0034] Radical polymerizable compound (A) The radical polymerizable compound (A) used in this disclosure is not particularly limited as long as it has a functional group in its molecule that can react with a radical (i.e., a radical polymerizable functional group). Typically, such functional groups include functional groups having ethylenically unsaturated bonds, such as (meth)acrylic groups and vinyl groups, and the following are examples of compounds having these. The radical polymerizable compound (A) must contain at least one radical polymerizable functional group, and may contain two or more. A radical polymerizable compound (A) consisting of a single compound, rather than a structure formed by the polymerization of two or more compounds of the same structure, may be referred to as a monomer.

[0035] In some embodiments, the radical polymerizable compound (A) includes a compound having at least one ethylenically unsaturated bond.

[0036] In some embodiments, the radical polymerizable compound (A) comprises a compound having at least two ethylenically unsaturated bonds.

[0037] In some embodiments, the radical polymerizable compound (A) comprises a (meth)acrylate compound having at least two (meth)acrylate groups.

[0038] In some embodiments, the radical polymerizable compound (A) comprises a (meth)acrylate compound having at least two (meth)acryloyloxy groups.

[0039] In a preferred embodiment, the meth(acrylate) compound having at least two (meth)acrylate groups is a compound represented by the following formula (1).

[0040] [ka]

[0041] In the above general formula (1), R 1R represents a hydrocarbon group having 1 to 40 carbon atoms which may have substituents, or a group in which some of the carbon atoms of the hydrocarbon group are substituted with oxygen or nitrogen atoms. 2 and R 3 Each of these independently represents either a hydrogen atom or a methyl group. 1 The hydrocarbon group with 1 to 40 carbon atoms represented by may or may not contain an unsaturated double bond. R 1 Examples of hydrocarbon groups having 1 to 40 carbon atoms represented by , or groups in which some of the carbon atoms of the hydrocarbon group are substituted with oxygen or nitrogen atoms, include alkylene groups, arylene groups, alkylene oxide groups, groups having urethane bonds, and combinations thereof, all having 1 to 40 carbon atoms. Examples of alkylene groups include linear, branched, cyclic, or any combination thereof (for example, a combination of linear and cyclic alkyl groups). When the alkylene group having 1 to 40 carbon atoms is a branched or cyclic alkyl group, one or more ends of the branch may be (meth)acrylate groups or (meth)acryloyloxy groups.

[0042] R 1 The number of carbon atoms in the hydrocarbon group having 1 to 40 carbon atoms represented by is preferably 1 to 22, more preferably 1 to 16, and even more preferably 4 to 12.

[0043] R 1 The hydrocarbon group having 1 to 40 carbon atoms, represented by , may be unsubstituted or substituted. The total number of these substituents in one molecule of the radical polymerizable compound (A) is preferably 1 to 10, for example, 1 to 4. If a substituent contains a carbon atom, this is not included in the carbon number of the hydrocarbon group.

[0044] In some embodiments, the radical polymerizable compound (A) may have an ether linkage, a polyoxyalkylene group (e.g., a polyoxyethylene group), etc., within the molecule.

[0045] In some embodiments, the radical polymerizable compound (A) may be a photopolymerizable compound having alkali-soluble substituents such as carboxyl groups, phenolic hydroxyl groups, or sulfonic acid groups in its molecule. When using alkali-soluble polymerizable compounds, the photopolymerizable composition containing these compounds can be polymerized and cured by light irradiation through a patterned mask, and then the unpolymerized photopolymerizable composition in the masked areas can be removed by alkali development, thereby forming a pattern.

[0046] The weight-average molecular weight of the radical polymerizable compound (A) is not particularly limited, but is, for example, 100 to 800.

[0047] The above radical polymerizable compound (A) may be used individually or in combination of two or more types.

[0048] Iodized monocyclic aromatic compounds (B) which may have substituents The iodized monocyclic aromatic compound (B), which may have substituents, has the advantage of readily releasing iodine upon irradiation with light due to its cyclic structure.

[0049] The optionally substituted iodized monocyclic aromatic compound (B) has one, two, three, or four or more iodines bonded to the aromatic ring. The optionally substituted iodized monocyclic aromatic compound (B) is preferably a six-membered monocyclic aromatic compound. The optionally substituted iodized monocyclic aromatic compound (B) may have substituents in positions other than the aromatic ring to which the iodines are bonded.

[0050] Examples of substituents include one or more substituents selected from the group consisting of alkyl groups having 1 to 18 carbon atoms.

[0051] Examples of iodized monocyclic aromatic compounds (B) that may have substituents include iodobenzene, 2-iodotoluene, 3-iodotoluene, 4-iodotoluene, 2-iodo-m-xylene, 2-iodo-p-xylene, 3-iodo-o-xylene, 4-iodo-o-xylene, 4-iodo-m-xylene, 5-iodo-m-xylene, 1-iodo-2-ethylbenzene, 1-iodo-4-ethylbenzene, 1-iodo-4-propylbenzene, 1-iodo-4-n-butylbenzene, 1-iodo-4-tert-butylbenzene, 1-iodo-5-(trifluoromethoxy)benzene, 1,2-diiodobenzene, 1,3-diiodobenzene, 1,2,3-triiodobenzene, 1,3,5-triiodobenzene, and the like.

[0052] In some preferred embodiments, the iodized monocyclic aromatic compound (B), which may have substituents, is asymmetric. The asymmetric nature of the iodized monocyclic aromatic compound (B) is advantageous for bulk polymerization because it results in a lower melting point. Asymmetric iodized monocyclic aromatic compound (B) means that it has two iodine atoms at the para position of the monocyclic aromatic ring and is not mirror-symmetric. Examples of symmetric substituents for the iodized monocyclic aromatic compound (B) include 1,4-diiodobenzene and 1,2,4,5-tetraiodobenzene. Iodized monocyclic aromatic compounds (B) that may have asymmetric substituents are limited to these compounds.

[0053] In some preferred embodiments, the optionally substituted iodized monocyclic aromatic compound (B) is liquid at 25°C. In some preferred embodiments, the optionally substituted iodized monocyclic aromatic compound (B) is liquid at 25°C and is soluble in the radical polymerizable compound (A).

[0054] The amount of iodine in the iodized monocyclic aromatic compound (B), which may have substituents, is preferably 10 to 60% by mass, more preferably 20 to 50% by mass, and even more preferably 20 to 30% by mass, relative to the total amount of the radical polymerizable compound (A).

[0055] Photopolymerization initiator (C) Photopolymerization initiator (C) is a radical initiator that extracts iodine upon irradiation with light.

[0056] Examples of photopolymerization initiators (C) include acylphosphine-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, aminobenzoate-based photopolymerization initiators, ketocoumarin-based photopolymerization initiators, anthraquinone-based photopolymerization initiators, oxime ester-based photopolymerization initiators, acetophenone-based photopolymerization initiators, benzoin-based photopolymerization initiators, and indan-based photopolymerization initiators. Examples of acetophenone-based photopolymerization initiators include alkylaminoacetophenone-based photopolymerization initiators and hydroxyacetophenone-based photopolymerization initiators. Each photopolymerization initiator may be used alone, two or more may be used in combination, or two or more different types of photopolymerization initiators may be combined.

[0057] Specific examples of acylphosphine oxide-based photopolymerization initiators include diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, ethoxyphenyl(2,4,6-trimethylbenzoyl)phosphine oxide, and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, as well as polymers of these compounds.

[0058] Specific examples of thioxanthone-based photopolymerization initiators include 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, 3-methoxythioxanthone, 2-carboxymethoxythioxanthone, 3-ethoxycarbonylmethoxythioxanthone, 3-butoxycarboxymethoxythioxanthone, 1,3-dimethyl-2-(2-ethylhexyloxy)thioxanthone, 2-[2,2-bis(ethoxycarbonyl)]ethylthioxanthone, 1-chloro-4-propoxythioxanthone, and polymers of these compounds.

[0059] Specific examples of aminobenzoate-based photopolymerization initiators include methyl 2-(dimethylamino)benzoate, ethyl 4-(dimethylamino)benzoate, ethyl 4-(diethylamino)benzoate, ethylhexyl 2-(dimethylamino)benzoate, 2-butoxyethyl 2-(dimethylamino)benzoate, bis-[(4-dimethylaminobenzoyl)oxyethylene-1-yl]methylamine, and polymers of these compounds (e.g., polyethylene glycol-bis(methyl 4-dimethylaminobenzoate)).

[0060] Specific examples of ketocoumarin-based photopolymerization initiators include 3-benzoyl-7-methoxycoumarin, 3-benzoyl-5,7-dimethoxycoumarin, 3-(4-tert-butylbenzoyl)-5,7-dimethoxycoumarin, 3-(4-hexylbenzoyl)-5,7-dimethoxycoumarin, 3-[4-(2-ethylhexyl)benzoyl]-5,7-dimethoxycoumarin, 5,7-dimethoxy-3-[4-(3,5,5-trimethylhexyl)benzoyl]coumarin, 7-methoxy-3-(4-methylbenzoyl)coumarin, 7-methoxy-3-(4-tert-butylbenzoyl)coumarin, 7-methoxy-3-(4-hexylbenzoyl)coumarin, and 7-methoxy-3-[4-(2-ethylhexyl)benzoyl]coumarin.

[0061] Examples of anthraquinone-based photopolymerization initiators include 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-phenoxyanthraquinone, 2-(phenylthio)anthraquinone, and 2-(hydroxyethylthio)anthraquinone.

[0062] Examples of commercially available oxime ester-based photopolymerization initiators include BASF's "Omnirad OXE01," "Omnirad OXE02," and "Omnirad OXE04."

[0063] Examples of commercially available alkylaminoacetophenone-based photopolymerization initiators include "Omnirad 907," "Omnirad 369," and "Omnirad 379" from IGM Resins.

[0064] Examples of commercially available hydroxyacetophenone-based photopolymerization initiators include "Omnirad 127," "Omnirad 184," "Omnirad 1173," "Omnirad 2959," and "Esacure KIP150" from IGM Resinss.

[0065] An example of a commercially available indan-based photopolymerization initiator is "SpeedCure XFs01" manufactured by LAMBSON.

[0066] Among the above photopolymerization initiators (C), acetophenone-based photopolymerization initiators are preferred in terms of solubility.

[0067] The amount of photopolymerization initiator (C) is preferably 0.001 to 20% by mass, more preferably 0.01 to 10% by mass, and even more preferably 0.1 to 5% by mass, relative to the total amount of radical polymerizable compounds (A). In the method for producing iodine-containing polymers according to this disclosure, by using a photopolymerization initiator (C) that has a strong iodine extraction effect under light, the amount of photopolymerization initiator (C) can be kept below the amount of iodized monocyclic aromatic compounds (B) which may have substituents.

[0068] In some preferred embodiments, the radical polymerizable compound (A), the optionally substituted iodized monocyclic aromatic compound (B), and the photopolymerization initiator (C) are all liquid at -20 to 70°C. Therefore, when the radical polymerizable compound (A), the optionally substituted iodized monocyclic aromatic compound (B), and the photopolymerization initiator (C) are mixed, a liquid mixture is obtained without heating. This is advantageous because the resulting liquid mixture can be used directly for bulk polymerization.

[0069] In some preferred embodiments, the radical polymerizable compound (A), the optionally substituted iodized monocyclic aromatic compound (B), and the photopolymerization initiator (C) are all liquid at 5-40°C. Therefore, when the radical polymerizable compound (A), the optionally substituted iodized monocyclic aromatic compound (B), and the photopolymerization initiator (C) are mixed, a liquid mixture is obtained without heating. This is advantageous because the resulting liquid mixture can be used directly for bulk polymerization.

[0070] In some preferred embodiments, the total amount of the radical polymerizable compound (A), the optionally substituted iodized monocyclic aromatic compound (B), and the photopolymerization initiator (C) relative to the mass of the photopolymerizable composition is 90% by mass or more, 95% by mass or more, or 98% by mass or more. By polymerizing such a photopolymerizable composition, a cured product with few impurities can be produced.

[0071] Other ingredients The photopolymerizable compositions disclosed herein may also contain polymerization inhibitors, chain transfer agents, etc., related to radical polymerization. Examples of polymerization inhibitors include phenols such as hydroquinone, methoxyhydroquinone, t-butylcatechol, and naphthohydroquinone; naphthols such as 1-naphthol, 2-naphthol, and 4-methoxy-1-naphthol; quinones such as benzoquinone, naphthoquinone, anthraquinone, and hydroxynaphthoquinone; and 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO) and 4-hydroxy-2,2,6,6-tetramethylpiperidinyl-1-oxyl.

[0072] The photopolymerizable compositions of this disclosure may optionally contain a solvent. The solvent used is not particularly limited, but hydrocarbon compounds such as hexane, heptane, cyclohexane, and decalin; halogen-substituted hydrocarbons such as chloroform, carbon tetrachloride, and dichloromethane; aromatic compounds such as benzene, toluene, and xylene; halogen-substituted aromatics such as chlorobenzene; ether compounds such as diethyl ether, tetrahydrofuran, tetrahydropyran, dioxane, propylene glycol monomethoxyacetate, and diglyme; ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; and ester compounds such as ethyl acetate and butyl acetate are preferably used.

[0073] The photopolymerizable compositions of this disclosure may further contain various resin additives within their normal range of use, such as colorants (including dyes), pigments, organic or inorganic fillers, leveling agents, surfactants, defoamers, thickeners, flame retardants, antioxidants, stabilizers, lubricants, plasticizers, and water repellents, as long as they do not impair the effects of the present invention. Examples of colorants include black pigments, yellow pigments, red pigments, blue pigments, and white pigments. In some preferred embodiments, the photopolymerizable compositions can undergo bulk polymerization without containing a catalyst to promote the iodine transfer polymerization reaction, such as an amine-based catalyst.

[0074] The photopolymerizable compositions of this disclosure can be readily polymerized and / or cured by light irradiation.

[0075] Although we do not wish for the present invention to be bound by theory, the polymerization of the photopolymerizable composition of this disclosure utilizes iodine transfer polymerization. When light is irradiated onto an iodized monocyclic aromatic compound (B), which may have substituents, a radical polymerizable compound (A) is added to the radical of the iodine compound residue generated by the elimination of iodine from the carbon-iodine bond of the iodized monocyclic aromatic compound (B). When light is irradiated onto a photopolymerization initiator (C), radicals derived from the photopolymerization initiator (C) are also generated, and it is thought that the radical polymerizable compound (A) is added to these radicals derived from the photopolymerization initiator (C). Therefore, the cured product obtained by curing the photopolymerizable composition of this disclosure is a mixture or crosslinked product comprising the following (1) and (2): (1) A polymer formed in which multiple structural units derived from a radical polymerizable compound (A) are repeatedly bonded to the radical of an iodine compound residue obtained by removing iodine from an iodized monocyclic aromatic compound (B), and iodine is bonded to the end of this repeating structural unit opposite to the iodine compound residue obtained by removing iodine from an iodized monocyclic aromatic compound (B). (2) A polymer formed in which multiple structural units derived from a radical polymerizable compound (A) are repeatedly bonded to a radical of a photopolymerization initiator (C).

[0076] In the case of a crosslinked product, at least some of the polymers from (1) are crosslinked with each other, at least some of the polymers from (2) are crosslinked with each other, and / or at least some of the polymers from (1) and at least some of the polymers from (2) are crosslinked via alkylene groups at the positions of structural units derived from the radical polymerizable compound (A) of both polymers, or at least some of the polymers from (1) are crosslinked within a single molecule via alkylene groups at the positions of adjacent structural units derived from the radical polymerizable compound (A), or both.

[0077] In certain embodiments, the cured product obtained by curing the photopolymerizable composition of the present disclosure includes some or all of the following (i) to (v):

[0078] [ka]

[0079] In equation (i), n is an integer greater than or equal to 1. In formula (v), P is the part derived from the photopolymerization initiator.

[0080] The polymerization method may be any known polymerization method such as bulk polymerization, solution polymerization, suspension polymerization, or emulsion polymerization, but bulk polymerization is preferred. Bulk polymerization is advantageous in that it does not require a solvent, allows for rapid polymerization of the radical polymerizable compound (A) using light such as ultraviolet light, offers high productivity, and enables ultrafine processing. Because the polymerizable composition of this disclosure contains an iodized monocyclic aromatic compound (B), the polymerizable composition can be bulk polymerizable while also being X-ray radiopaque.

[0081] The polymerization time for the polymerization step of the photopolymerizable composition of the present disclosure is not particularly limited, but is between 1 second and 10 minutes. The polymerization temperature for the polymerization step of the photopolymerizable composition of the present disclosure is not particularly limited, but is between -20 and 70°C.

[0082] The photopolymerizable composition disclosed herein offers a high degree of manufacturing flexibility, can be polymerized and cured in various ways, and can be molded into various shapes. For example, a coating, film, or sheet can be obtained by irradiating light onto a photopolymerizable composition applied to a suitable substrate, or by sandwiching the photopolymerizable composition between glass plates with spacers. Alternatively, a polymerized and cured molded product can be obtained by irradiating light onto a photopolymerizable composition poured into a light-transmitting mold (e.g., a mold made by photolithography). Furthermore, polymerization and curing can be performed according to the pattern by applying the photopolymerizable composition and then irradiating it with light through a mask having a suitable pattern. Additionally, by irradiating light onto a photopolymerizable composition ejected from the nozzle of an inkjet printer, the composition applied to the substrate can be polymerized and cured, or a three-dimensional object can be formed while the composition is polymerized. Moreover, stereolithography is a method for obtaining cured products in three-dimensional shapes using the photopolymerizable composition. Specifically, for example, a cured product in three-dimensional shapes can be obtained by repeatedly irradiating a layered photopolymerizable composition with ultraviolet light in a patterned manner, thereby forming a cured layer in the irradiated area. There are no particular restrictions on the equipment used to perform stereolithography; 3D printers and the like can be used.

[0083] When using light irradiation, it is preferable to use a light source that includes light with a wavelength of 300 to 500 nm. A light source containing multiple wavelength components is also acceptable, as is a light source that emits so-called monochromatic light, such as an LED or laser light. Specifically, examples include high-pressure mercury lamps, ultra-high-pressure mercury metal halide lamps, gallium-doped lamps, microwave-excited UV lamps, LED lamps, or laser light.

[0084] Uses of photopolymerizable compositions The photopolymerizable compositions disclosed herein can be used in coatings, paints, inks, molding materials, etc., that can be polymerized and / or cured by light irradiation. Specifically, it can be applied to a wide range of applications, including coatings or protective film materials such as paints applied to substrates such as metal, resin, glass, paper, and wood, hard coats, stain-resistant films, anti-reflective films, shock-absorbing films, and overcoats; photocurable adhesives and sealants; photodegradable paints, coatings, and molded products; optical recording media or materials for optical recording media such as holographic materials; resins for photopolymerization; inks for 3D printers; resists for electronic circuits and semiconductor manufacturing; resists for color filters in displays such as liquid crystal displays and organic EL displays; resists for electronic materials such as black matrix resists and dry film resists; interlayer insulating films, protective films, light extraction films, encapsulants, and sealants; printing inks for screen printing, offset printing, and gravure printing; photocurable inks for inkjet printers; compositions for laser patterning; optical components such as lenses, lens arrays, optical waveguides, light guide plates, light diffusers, diffracting elements, and optical adhesives; and nanoimprinting. The photopolymerizable compositions disclosed herein, upon polymerization and / or curing, become X-ray absorbing iodine-containing polymers, and are therefore useful for the manufacture of coatings for medical devices and drug delivery carriers that are visible by X-rays. Furthermore, the photopolymerizable compositions are also useful for sensitizing resists for EUV exposure.

[0085] Iodine-containing polymer The iodine-containing polymer obtained by the method for producing the iodine-containing polymer of this disclosure is an X-ray contrast-enhanced resin. If the iodine-containing polymer has two or more components, it may be referred to as an "iodine-containing resin composition."

[0086] The iodine-containing polymer is a polymer and / or cured product of a photopolymerizable composition containing a radical polymerizable compound (A), an iodized monocyclic aromatic compound (B) which may have substituents, a photopolymerization initiator (C), and an optional other component (D).

[0087] The iodine content in the iodine-containing polymer is not particularly limited, but is, for example, 10 to 60% by mass. The weight-average molecular weight of the iodine-containing polymer is not particularly limited, but may be, for example, 2,000 to 1,000,000, or 4,000 to 10,000.

[0088] In some embodiments, the iodine-containing polymer is a cured product of the above-mentioned photopolymerizable composition, and is an iodine-containing polymer having a structural unit derived from a radical polymerizable compound (A), a structural unit having a monocyclic aromatic ring derived from an iodized monocyclic aromatic compound (B) which may have substituents and is bonded to one end of the structural unit derived from the radical polymerizable compound (A), and iodine bonded to another end of the structural unit derived from the radical polymerizable compound (A).

[0089] In some embodiments, in the iodine-containing polymer, adjacent structural units derived from the radical polymerizable compound (A) are crosslinked.

[0090] In some embodiments, the iodine-containing polymer is a cured product of the above photopolymerizable composition and comprises a plurality of iodine-containing polymers, each having a structural unit derived from a radical polymerizable compound (A), a structural unit having a monocyclic aromatic ring derived from an iodized monocyclic aromatic compound (B) which may have substituents and bonded to one end of the structural unit derived from the radical polymerizable compound (A), and iodine bonded to another end of the structural unit derived from the radical polymerizable compound (A), wherein one of the plurality of iodine-containing polymers is crosslinked with another of the plurality of iodine-containing polymers.

[0091] In a particular embodiment, the iodine-containing polymer is an iodine-containing polymer represented by the following formula (I).

[0092] [ka]

[0093] (In formula (I), R 1 , R 4 , and R 7 Each of these independently represents a hydrocarbon group having 1 to 40 carbon atoms which may have substituents, or a group in which some of the carbon atoms of the hydrocarbon group are substituted with oxygen or nitrogen atoms, and R 1 and R 4 , and / or R 4 and R 7 It may be crosslinked via an alkylene group. R 2 , R 5 , and R 8 Each of these independently represents a hydrogen atom or a methyl group. R 3 , R 6 , and R 9 Each of these independently represents a hydrogen atom or a methyl group. l, m, and n are 0 or integers greater than or equal to 1, except when l, m, and n are all 0.

[0094] R in equation (I) 1 , R 4 , and R 7 For details, see R in equation (1) 1 As explained in the relevant section. R in equation (I) 2 , R 5 , and R 8 For details, see R in equation (1) 2 As explained in the previous section. R in equation (I) 3 , R 6 , and R 9 For details, see R in equation (1) 3 As explained in the previous section.

[0095] As described above, iodine-containing polymers can be molded into products cured in a mold or into three-dimensional molded products made using a 3D printer, and such products can be visually inspected by X-ray. Therefore, this disclosure also provides a method for inspecting articles containing iodine-containing polymers, which includes inspecting the articles made of the above-mentioned iodine-containing polymers using X-rays.

[0096] All patent applications and document disclosures cited herein are incorporated herein by reference in their entirety. The following examples are for illustrative purposes only and are not intended to limit the technical scope of the present invention in any way. Unless otherwise specified, reagents may be commercially available or obtained or prepared by methods commonly used in the art or by procedures in known literature. [Examples]

[0097] Example 1. Preparation of the resin 1.003 g of the monomer 1,6-hexanediol diacrylate (HDDA) was weighed into a 9 cc sealed reagent bottle, and 25 wt% (0.34 g) of diiodobenzene was added dropwise. (Mono)iodobenzene is liquid at around room temperature and can be added directly, but 1,3-diiodobenzene and 1,2,3-triiodobenzene have melting points around room temperature and may be solid depending on the room temperature conditions. In that case, they were heated in an electric furnace at 45°C for 10 minutes to become liquid before being added dropwise. If both were solid, they could be added to the monomer as solids. Since iodobenzene is soluble in HDDA, it did not solidify or precipitate even at temperatures below room temperature after dissolution. 1.3 wt% (0.0179 g) of the photopolymerization initiator Omnirad369 (2-benzyl-2-(dimethylamino)-4'-molar butyrophenone) was added to this mixture. Next, the mixture was stirred with ultrasound for 10 minutes to completely dissolve the photopolymerization initiator. This yielded a brown, transparent, low-viscosity liquid mixture (Figure 1). Since iodobenzene readily releases iodine in the presence of light, it is desirable to perform the above mixing process in the dark. This mixture was curable with a UV lamp or LED. The UV wavelength required for curing depends on the absorption wavelength of the other photopolymerization initiators, but in this case, curing was possible in the range of 400-365 nm. Although some reports suggest that twice the amount of photopolymerization initiator as the iodine compound is required, polymerization is possible with the proposed combination using approximately 1 wt% of the total amount of monomer and iodine compound.

[0098] [ka]

[0099] Example 2. Bulk curing 20 μL of a liquid mixture containing HDDA, iodized compound, and Omnirad369 prepared in Example 1 was measured using a micropipette and dropped onto a PP film. This mixture was then vacuumed to 100 Pa in a glass container. Vacuuming is necessary because radical polymerization is inhibited by oxygen. A 365 nm UV-LED was irradiated from outside the glass container for 60 seconds to obtain a brown, transparent cured product. This demonstrated that the proposed iodine resin can be produced by bulk polymerization. The cured material was fixed onto a glass substrate, and X-ray imaging was performed using X-ray CT. X-rays of 49 keV and 100 keV were used. Images of the respective cured materials are shown in Figures 2 and 3.

[0100] Note that the CT image samples in Figures 2 and 3 are, from left to right: 1. A mixture of HDDA and Omnirad379 2. A mixture of iodobenzene, HDDA, and Omnirad 379. 3. A mixture of iodobenzene, HDDA, Omnirad 379, and triethylamine (catalyst) 4. A mixture of diiodomethane, HDDA, and Omnirad 379. 5. A mixture of diiodobenzene, HDDA, and Omnirad379 *Curing was performed under the same conditions as in Example 2, and the concentrations of the iodine compound, HDDA, and Omnirad379 were the same for all samples.

[0101] Example 3. Nanoimprint lithography A liquid mixture consisting of HDDA, diiodobenzene, and Omnirad369 prepared in Example 1 was measured using a 20 μL micropipette and dropped onto a release-treated mold (25 mm × 25 mm) made by photolithography of SU8 resin. A transparent PET film was placed over it and allowed to stand for 3 minutes, sufficient time for the liquid mixture to fill the space between the mold and the PET film. After that, the liquid mixture was cured by irradiating it with a 365 nm UV-LED for 60 seconds, with the light passing through the PET film. After curing, the mold was released, and a transfer made of iodine resin was obtained on the PET film. Note that a mold made by etching glass may also be used. In this case, a negative pattern was fabricated on a silicon wafer using SU8 resin and used as the mold. A 100 nm Pt layer was coated onto this mold by sputtering, and then the mold was released by immersing it in a 1.0% NOVEC7200 solution from Optool (Daikin Industries) for 24 hours. After immersion, the mold was baked at 85°C for 3 hours. The resulting iodine resin cured material clearly exhibited dot and line patterns (Figures 4, 5(A), (B)). No difference in nanoimprint performance was observed compared to commercially available nanoimprint resins. The proposed iodine resin was shown to be lithographic and possess high fine moldability.

[0102] X-ray examination was performed on these transfers using 100 keV X-rays. A clear difference in contrast was observed in the X-ray CT images within the same field of view between the standard UV-curing resin transfer (left half) and the iodine resin transfer (right half).

[0103] Example 4. 3D Printing Diiodobenzene and Omnirad379 were mixed with 25 ml of HDDA in the same weight ratio as in Example 1. In this case, 8.5 g and 0.44 g of diiodobenzene and Omnirad379 were added sequentially to 25 ml of HDDA, and the mixture was stirred with ultrasound for 10 minutes. This mixture became a brown, transparent, low-viscosity liquid similar to that in Example 1.

[0104] 25 ml of this liquid was poured into the resin tank of a commercially available LCD-type 3D printer, and a 3D model was 3D printed to obtain a three-dimensional molded structure of iodine resin on a Si wafer plate (Figure 7). The molded object was a brown, transparent, L-shaped object when viewed from the side. During 3D printing, the curing time for one layer was 10 seconds, the thickness of one layer was 0.02 mm, and the total printing time was approximately 2 hours and 30 minutes. This demonstrates that the proposed iodine resin can be 3D printed and that high-speed printing is possible.

Claims

1. A method for producing an iodine-containing polymer, comprising polymerizing a photopolymerizable composition containing a radical polymerizable compound (A), an iodized monocyclic aromatic compound (B) which may have substituents, and a photopolymerization initiator (C).

2. The manufacturing method according to claim 1, wherein the polymerization of the photopolymerizable composition includes bulk polymerization.

3. The method according to claim 1 or 2, wherein the radical polymerizable compound (A) comprises a compound having at least one ethylenically unsaturated bond.

4. The method for producing an iodized monocyclic aromatic compound (B) which may have the substituents is asymmetric.

5. The manufacturing method according to claim 1, wherein the iodine-containing polymer is an X-ray contrast-enhanced resin.

6. A photopolymerizable composition comprising a radical polymerizable compound (A), an iodized monocyclic aromatic compound (B) which may have substituents, and a photopolymerization initiator (C).

7. An iodine-containing polymer which is a cured product of the photopolymerizable composition according to claim 6.

8. Structural units derived from radical polymerizable compound (A), A structural unit having a monocyclic aromatic ring derived from an iodized monocyclic aromatic compound (B), which may have substituents, is bonded to one end of a structural unit derived from the radical polymerizable compound (A), An iodine-containing polymer which is a cured product of the photopolymerizable composition according to claim 6, comprising iodine bonded to another end of a structural unit derived from the radical polymerizable compound (A).

9. The iodine-containing polymer according to claim 8, wherein adjacent structural units derived from the radical polymerizable compound (A) are crosslinked.

10. An iodine-containing polymer comprising a plurality of iodine-containing polymers as described in claim 8, wherein one of the plurality of iodine-containing polymers is crosslinked with another of the plurality of iodine-containing polymers.

11. An iodine-containing polymer represented by the following formula (I). 【Chemistry 1】 (Formula (I), where R １ , R 4 , and R 7 Each of these independently represents a hydrocarbon group having 1 to 40 carbon atoms which may have substituents, or a group in which some of the carbon atoms of the hydrocarbon group are substituted with oxygen or nitrogen atoms, R １ and R 4 , and / or R 4 and R 7 It may be crosslinked via an alkylene group. R 2 , R 5 , and R 8 each independently represents a hydrogen atom or a methyl group, R 3 , R 6 , and R 9 Each of these independently represents a hydrogen atom or a methyl group. l, m, and n are 0 or integers greater than or equal to 1, except when l, m, and n are all 0.

12. A method for inspecting an article containing an iodine-containing polymer, comprising inspecting the article, which is made of an iodine-containing polymer according to any one of claims 7 to 11, using X-rays.

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