JP2005336150A - Diimmonium compound and use of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a near infrared light absorbing compound having excellent stability, especially, having heat resistance, light resistance, and resistance to moist heat, without containing antimony, nor arsenic, to provide an infrared light absorbing filter manufactured by using the near infrared light absorbing compound and having excellent resistance, such as the light resistance, and to provide an optical memory medium. <P>SOLUTION: A diimmonium compound is expressed formula (1) (R<SB>1</SB>to R<SB>8</SB>are each H or an aliphatic hydrocarbon residue which may be substituted; R<SB>9</SB>and R<SB>10</SB>are each an aliphatic hydrocarbon residue which may have a halogen; and ring A and ring B may be further substituted). The near infrared light absorbing filter is obtained by using the compound. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a diimonium compound having absorption in the infrared region and its use. In particular, the present invention relates to a diimonium compound that is not a deleterious substance, has excellent heat resistance, light resistance, solubility, and the like, and whose applications are expanded, an infrared absorption filter using the compound, an optical storage medium, and a resin composition thereof.

  Conventionally, diimonium compounds as near-infrared absorbers are widely known (see, for example, Patent Documents 1 to 3), and are widely used in near-infrared absorption filters, heat insulating films, sunglasses, and the like. However, among these compounds, those whose counter ions are hexafluoroantimonate ions, arsenic hexafluoride ions, etc. have excellent heat resistance, and among them, compounds of hexafluoroantimonate ions were mainly used. . However, since compounds containing antimony fall under the category of deleterious substances, compounds that do not contain these metals have been desired in recent years in the industrial field where the use of heavy metals and the like is restricted, particularly in the field of electrical materials. As a means to solve this, there is a method using perchlorate ion, hexafluorophosphate ion, borofluoride ion, etc. as a counter ion. However, in view of heat resistance and moist heat resistance, these counter ions are not sufficient. is there. Further, compounds using an organic counter ion such as naphthalenedisulfonic acid have been proposed (see, for example, Patent Document 2), but since the molar extinction coefficient is low and the compound itself is greenish, it can be used in practice. could not. Further, those using trifluoromethanesulfonic acid ions or the like are also known (see, for example, Patent Document 1), but they still cannot be said to have sufficient heat resistance and heat-and-moisture resistance (see, for example, Patent Document 4). ), And better materials were sought.

Japanese Patent Publication No. 7-51555 (2nd page) JP 10-316633 A (page 5) Japanese Patent Publication No. 43-25335 (pages 7-14) Japanese Patent Application No. 2003-017537

  The present invention has been made in view of such circumstances, and an object of the present invention is to contain a near-infrared absorbing compound that does not contain antimony and has excellent stability, in particular, heat resistance, light resistance, and heat and humidity resistance, Furthermore, it is possible to provide an infrared absorption filter (especially for a plasma display panel) having excellent solubility and the use of such a compound, and an optical storage medium and a resin excellent in resistance such as weather resistance. It is to provide a composition.

As a result of diligent efforts to solve the above-described problems, the present inventors have found that a diimonium compound having a specific structure can solve the above-mentioned problems, and completed the present invention.
That is, the present invention
(1) A diimonium compound represented by the following formula (1)

(In Formula (1), R _{1 to} R ₈ each independently represents an aliphatic hydrocarbon residue which may have a hydrogen atom or a substituent, and R ₉ and R ₁₀ each independently have a halogen atom. Each represents a good aliphatic hydrocarbon, and rings A and B may further have a substituent).
(2) The diimonium compound according to (1), wherein R ₉ and R _{10 in} the formula (1) are aliphatic hydrocarbon residues having a fluorine atom,
(3) The diimonium compound according to (2), wherein R ₉ and R _{10 in} formula (1) are trifluoromethyl groups,
(4) The diimonium compound according to any one of (1) to (3), wherein at least one of R _{1 to} R ₈ in Formula (1) is a linear or branched (C1-C6) alkyl group. ,
(5) The diimonium compound according to (4), wherein at least one of R _{1 to} R ₈ in formula (1) is a linear (C1-C3) alkyl group,
(6) The diimonium compound according to (4), wherein at least one of R _{1 to} R ₈ in formula (1) is a branched alkyl group,
(7) The diimmonium compound according to (6), wherein R _{1 to} R _{8 in} formula (1) are all alkyl groups branched at the ends,
(8) The diimonium compound according to (7), wherein R _{1 to} R _{8 in} formula (1) are an iso-butyl group or an iso-amyl group,
(9) The substituent of the aliphatic hydrocarbon residue which may have a substituent of R _{1 to} R _{8 in} the formula (1) is a halogen atom, cyano group, nitro group, hydroxyl group, carboxyl group, carbonamide group , A diimonium compound according to any one of (1) to (3), which is an alkoxycarbonyl group, an acyl group, an aryl group or an alkoxyl group,
(10) The diimonium compound according to (9), wherein R _{1 to} R _{8 in} formula (1) are all alkyl groups substituted with a cyano group,
(11) The diimonium compound according to (9), wherein at least one of R _{1 to} R ₈ is an alkyl group substituted with a cyano group, and at least one is an alkyl group,
(12) A composition comprising the diimonium compound according to any one of (1) to (11) and a resin,
(13) A near-infrared absorption filter having a layer containing the diimonium compound according to any one of (1) to (12),
(14) A plasma display comprising the near-infrared absorbing filter according to (13),
(15) An optical information recording medium comprising the diimonium compound according to any one of (1) to (11) in a recording layer,
About.

The near-infrared absorbing diiminium compound of the present invention does not contain antimony or arsenic, does not correspond to a deleterious substance, has a high molar extinction coefficient of 90,000 or more, and is excellent in heat resistance, light resistance, solubility and the like. is there. Moreover, it is particularly excellent in heat resistance and moist heat resistance as compared with conventional diimonium salts having hexafluorophosphate ions, perchlorate ions, and borofluoride ions. The near-infrared absorption filter using the diiminium compound of the present invention is a near-infrared absorption filter that does not contain antimony or the like and is extremely excellent in heat resistance, hardly undergoes a reaction such as decomposition due to heat, and is hardly colored in the visible region. unacceptable. Because of having such a feature, the diiminium compound of the present invention can be suitably used for a near-infrared absorption filter, a near-infrared absorption film such as a heat insulating film and sunglasses, in particular, a plasma display. It is suitable for a near-infrared absorption filter.
Further, the optical information recording medium of the present invention can greatly improve the light resistance as compared with the conventional optical information recording medium containing a diimonium compound. In addition, these diimonium compounds have sufficient solubility in preparing an optical information recording medium and are excellent in processability. Further, for example, when this compound is contained in an organic dye thin film corresponding to the recording layer of the optical information recording medium, an optical information recording medium having remarkably improved durability and light resistance stability in repeated reproduction can be provided.

  The diimonium compound of the present invention has a diimonium cation and two salts of a di (alkylsulfonyl) imide anion as a counter ion, and is represented by the formula (1).

In the formula (1), R ₉ and R ₁₀ independently represent an aliphatic hydrocarbon which may have a halogen atom. Examples of the aliphatic hydrocarbon include saturated and unsaturated linear, branched and cyclic alkyl groups, preferably having 1 to 36 carbon atoms, more preferably saturated linear alkyl which may have a substituent. Group having 1 to 20 carbon atoms, most preferably 1 to 4 carbon atoms. The halogen atom is preferably a fluorine, chlorine, bromine or iodine atom, more preferably a fluorine, chlorine or bromine atom, and most preferably a fluorine atom. As specific examples, R ₉ and R ₁₀ are each independently a methyl group, a trifluoromethyl group, a difluoromethyl group, a monofluoromethyl group, a dichloromethyl group, a monochloromethyl group, a dibromomethyl group, a difluorochloromethyl group, Ethyl group, pentafluoroethyl group, tetrafluoroethyl group, trifluoroethyl group, trifluorochloroethyl group, difluoroethyl group, monofluoroethyl group, trifluoroiodoethyl group, propyl group, heptafluoropropyl group, hexafluoropropyl Group, pentafluoropropyl group, tetrafluoropropyl group, trifluoropropyl group, difluoropropyl group, monofluoropropyl group, perfluorobutyl group, perfluorohexyl group, perfluorooctyl group, perfluorooctylethyl group, etc. Saturated linear alkyl group, allyl group, tetrafluoroallyl group, trifluoroethylene group, perfluorobutylethylene group and other unsaturated alkyl groups, isopropyl group, pentafluoroisopropyl group, heptafluoroisopropyl group, perfluoro-3-methylbutyl Groups, branched alkyl groups such as perfluoro-3-methylhexyl group, cyclic alkyl groups such as cyclohexyl group, and the like, and those in which R ₉ and R ₁₀ are the same are preferred. Furthermore, R ₉ and R ₁₀ can be bonded to form a cyclic alkyl group.

R ₉ and R ₁₀ are both preferably aliphatic hydrocarbon groups having a fluorine atom. Specific examples thereof include trifluoromethyl group, difluoromethyl group, monofluoromethyl group, pentafluoroethyl group, tetrafluoroethyl group. Group, trifluoroethyl group, difluoroethyl group, heptafluoropropyl group, hexafluoropropyl group, pentafluoropropyl group, tetrafluoropropyl group, trifluoropropyl group, perfluorobutyl group, etc., preferably trifluoromethyl group Group, difluoromethyl group, pentafluoroethyl group, trifluoroethyl group, heptafluoropropyl group, tetrafluoropropyl group and perfluorobutyl group, more preferably trifluoromethyl group. In each of the above groups, the alkyl moiety is normal unless otherwise specified.

In formula (1), rings A and B may or may not have 1 to 4 substituents other than the 1,4-position. Examples of the substituent that can be bonded include a halogen atom, a hydroxyl group, a lower alkoxy group, a cyano group, and a lower alkyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Examples of the alkoxy group include C1-C5 alkoxy groups such as methoxy group and ethoxy group, and examples of the lower alkyl group include C1-C5 alkyl groups such as methyl group and ethyl group. It is preferable that both A and B have no substituent, or are substituted with a halogen atom (especially chlorine atom, bromine atom, fluorine atom), methyl group or cyano group.
When B has a substituent, it is preferable that all four B rings are the same, and that the position of the substituent is m-position with respect to the nitrogen atom bonded to the phenylenediamine skeleton. Further, rings A and B preferably have no substituent other than the 1,4-position.

R _{1 to} R ₈ independently represent a hydrogen atom or an aliphatic hydrocarbon residue that may have a substituent. The aliphatic hydrocarbon residue means a group obtained by removing one hydrogen atom from a saturated and unsaturated linear, branched and cyclic aliphatic hydrocarbon. Examples of the carbon number include those having 1 to 36, preferably 1 to 20 carbon atoms.

  Specific examples of the saturated aliphatic hydrocarbon residue or unsaturated aliphatic hydrocarbon residue having no substituent include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso- Butyl, s-butyl, ter-butyl, n-pentyl, iso-pentyl, ter-pentyl, octyl, decyl, dodecyl, octadecyl, isopropyl, cyclopentyl, cyclohexyl, vinyl Group, allyl group, propenyl group, pentynyl group, butenyl group, hexenyl group, hexadienyl group, isopropenyl group, isohexenyl group, cyclohexenyl group, cyclopentadienyl group, ethynyl group, propynyl group, hexynyl group, An isohexynyl group, a cyclohexynyl group, etc. are mentioned. Among these, preferred are methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, ter-butyl group, n-pentyl group. , Iso-pentyl group, ter-pentyl group, vinyl group, allyl group, propenyl group, pentynyl group, etc., C1-C5 straight chain, branched chain saturated aliphatic hydrocarbon residue or unsaturated aliphatic hydrocarbon residue Groups and the like.

In the present invention, at least one of R _{1 to} R ₈ is a linear or branched (C1-C6) alkyl group, and at least one of R _{1 to} R ₈ is a linear (C1-C3). ) preferably has an alkyl group, also as an alkyl group of at least one branched out of R ₁ to R _8, especially those wherein the alkyl groups R ₁ to R ₈ are branched at all ends Is preferred. As R _{1 to} R ₈ , all of which are alkyl groups that are branched at the terminal, it is particularly preferable that R _{1 to} R ₈ are all an iso-butyl group or an iso-amyl group.

  Examples of the substituent in the aliphatic hydrocarbon residue having a substituent include, for example, a halogen atom (eg, F, Cl, Br), a hydroxy group, an alkoxy group (eg, a methoxy group, an ethoxy group, an isobutoxy group, etc.) , Alkoxyalkoxy groups (eg, methoxyethoxy group, etc.), aryl groups (eg, phenyl group, naphthyl group, etc., this aryl group may further have a substituent), aryloxy groups (eg, phenoxy group, etc.) , Acyloxy groups (eg, acetyloxy group, butyryloxy group, hexyloxy group, benzoyloxy group, etc., this aryloxy group may further have a substituent), amino groups, alkyl-substituted amino groups (eg, methylamino) Group, dimethylamino group, etc.), cyano group, nitro group, carboxyl group, carbonamido group, alkoxycarbonyl (Eg, methoxycarbonyl, ethoxycarbonyl, etc.), an acyl group, an amido group (e.g., such as acetamido group), a sulfonamido group (e.g., a methanesulfonamido group), a sulfo group. Of these substituents, a halogen atom, cyano group, nitro group, hydroxyl group, carboxyl group, carbonamido group, alkoxycarbonyl group, acyl group, aryl group or alkoxyl group are preferred.

  These groups can exist independently, for example, one amino group substituted with an unsubstituted linear alkyl group and a cyano substituted alkyl group, an unsubstituted branched alkyl group and a cyano substituted alkyl. A group substituted, an unsubstituted linear alkyl group and an unsubstituted branched alkyl group may be substituted.

  Specific examples of the aliphatic hydrocarbon residue having a substituent include cyanomethyl group, 2-cyanoethyl group, 3-cyanopropyl group, 2-cyanopropyl group, 4-cyanobutyl group, 3-cyanobutyl group, 2-cyanobutyl group. Group, 5-cyanopentyl group, 4-cyanopentyl group, 3-cyanopentyl group, 2-cyanopentyl group, cyano-substituted (C1-C6) alkyl group such as 3,4-dicyanobutyl group, methoxyethyl group, ethoxy Alkoxy-substituted (C1-C6) alkyl groups such as ethyl group, 3-methoxypropyl group, 3-ethoxypropyl group, 4-methoxybutyl group, 4-ethoxybutyl group, 5-ethoxypentyl group, 5-methoxypentyl group, Trifluoromethyl group, monofluoromethyl group, pentafluoroethyl group, tetrafluoroethyl group, trifluoroether Group, heptafluoropropyl group, perfluorobutyl group, perfluorobutyl ethyl group, perfluorohexyl group, perfluorohexyl ethyl group, perfluorooctyl group, fluoride, such as perfluorooctyl ethyl (C1 to C8) alkyl group, and the like.

In the present invention, all of R _{1 to} R ₈ are diimonium compounds each having an alkyl group substituted with a cyano group, or at least one of R _{1 to} R ₈ is an alkyl group substituted with a cyano group, and at least one Is particularly preferably a diimonium compound which is an alkyl group.

  The diimonium compound represented by the formula (1) of the present invention can be obtained, for example, by a method according to the method described in Patent Document 3. That is, the following formula (4) obtained by reducing the product obtained by the Ullmann reaction of p-phenylenediamine and 1-chloro-4-nitrobenzene.

(In formula (4), rings A and B are as defined above.)
In an organic solvent, preferably DMF (dimethylformamide), DMI
A halogenated compound corresponding to the desired R _{1 to} R ₈ in a water-soluble polar solvent such as (dimethylimidazolinone) or NMP (N-methylpyrrolidone) at 30 to 160 ° C., preferably 50 to 140 ° C. (for example, When R _{1 to} R ₈ are nC ₄ H ₉ , they are reacted with n-C ₄ H ₉ Br), and all the substituents (R _{1 to} R ₈ ) are the same (hereinafter referred to as all substituents). (Formula (2)) can be obtained. In addition, when synthesizing the following formula (2) other than a compound in which all of R _{1 to} R ₈ are the same substituents (for example, the precursor of the compound of the following compound example No. 34), a predetermined number of moles is first obtained. After reacting with the reagent (n-C ₄ H ₉ Br) (4 moles per mole of the above formula (4)) to introduce n-butyl groups into four of R _{1 to} R ₈ , the remaining substituents Also by reacting with the corresponding reagent (iso-C ₄ H ₉ Br) in the number of moles required to introduce (iso-butyl group) (4 moles per mole of amine body of formula (4) above) The compound (2) can be synthesized. Arbitrary compounds other than all substitution products can be obtained by the same method as the production method of the exemplified compound No. 34.

  The compound synthesized above is oxidized in an organic solvent, preferably in a water-soluble polar solvent such as DMF, DMI, NMP, etc. at 0 to 100 ° C., preferably 5 to 70 ° C. 2 equivalents of silver salt) is added to carry out the oxidation reaction. Further, the compound synthesized above is oxidized with an oxidizing agent such as silver nitrate, silver perchlorate, or cupric chloride, and then the anion acid or salt of formula (3) is added to the reaction solution to perform salt exchange. The diimonium compound represented by the formula (1) can also be synthesized by the method.

Next, specific examples of the diimonium compound of the present invention represented by the formula (1) are shown in Tables 1 (1) to 1 (4). In the table, regarding R _{1 to} R ₈ , i- represents a branched state such as “iso-”, and Ph represents a phenyl group. As for A and B, when there is no substitution at positions other than the 1,4-position, it is expressed as “4H”, and the substitution position is the substitution position for the nitrogen atom bonded to the phenylenediamine skeleton. Also relates to R ₁ to R _8, when R ₁ to R ₈ are all n- butyl is abbreviated as _{"4 (n-C 4 H 9} , n-C 4 H 9) ", also for example, When one is an iso-pentyl group and the rest is an n-butyl group, that is, one of four combinations of substituents includes an iso-pentyl group, and the remaining three sets are all n-butyl groups In this case, it is abbreviated as “3 (n-C ₄ H ₉ , n-C ₄ H ₉ ) (n-C ₄ H ₉ , i-C ₅ H ₁₁ ). A group formed by bonding to form a piperidine ring is shown as “(piperidine ring).” Furthermore, cy means cyclo.Also, in R ₉ and R ₁₀ , all of the alkyl moieties having 3 or more carbon atoms are normal.

The composition of this invention contains resin and the diimonium compound of this invention shown by Formula (1).
Specific examples of resins that can be used include polyethylene compounds such as polyethylene, polystyrene, polyacrylic acid, polyacrylic acid esters, polyvinyl acetate, polyacrylonitrile, polyvinyl chloride, and polyvinyl fluoride, and addition polymers of these vinyl compounds. Polymethacrylic acid, polymethacrylic acid ester, polyvinylidene chloride, polyvinylidene fluoride, poly (vinylidene fluoride), vinylidene fluoride / trifluoroethylene copolymer, vinylidene fluoride / tetrafluoroethylene copolymer, vinylidene cyanide / vinyl acetate Polymers such as polymers, copolymers of vinyl compounds or fluorine compounds, resins containing fluorine such as polytrifluoroethylene, polytetrafluoroethylene, polyhexafluoropropylene, polyamides such as nylon 6 and nylon 66, De, polyurethanes, polypeptides, polyesters such as polyethylene terephthalate, polycarbonate, polyether polyoxymethylene or the like, epoxy resins, polyvinyl alcohol, polyvinyl butyral, and the like.

The method for producing the composition of the present invention is not particularly limited, and for example, the following methods known per se can be used.
(1) A method of preparing a resin plate or film by kneading the diimonium compound of the present invention into a resin and thermoforming it,
(2) A method of producing a resin plate or film by cast polymerization of the diimonium compound of the present invention and a resin monomer or a prepolymer of a resin monomer in the presence of a polymerization catalyst,
(3) A method of preparing a coating material containing the composition of the present invention and coating it on a transparent resin plate, a transparent film, or a transparent glass plate,
(4) A method for producing a laminated resin plate, a laminated resin film, or a laminated glass plate using the composition containing the diimonium compound of the present invention and a resin (adhesive),
Etc.

  As the production method of (1), the processing temperature, filming (resin plate) conditions, etc. are slightly different depending on the resin to be used. Usually, the diimonium compound of the present invention is added to the base resin powder or pellet, and 150 Examples include a method of heating and dissolving at ˜350 ° C. and then molding to produce a resin plate, or a method of forming a film (resin plate) with an extruder. The addition amount of the diimonium compound of the present invention varies depending on the thickness, absorption strength, visible light transmittance, etc. of the resin plate or film to be produced, but is usually 0.01 to 30% by weight, preferably based on the weight of the base resin. Is used in an amount of 0.03 to 15% by weight.

  In the method (2), the above compound and a resin monomer or a prepolymer of a resin monomer are injected into a mold in the presence of a polymerization catalyst and reacted to be cured, or poured into a mold and hardened in the mold. Solidify until a product is formed. Many resins can be molded in this process, and specific examples of resins that can employ such a method include acrylic resin, diethylene glycol bis (allyl carbonate) resin, epoxy resin, phenol-formaldehyde resin, polystyrene resin, silicon Resin, and the like. Among them, the casting method by bulk polymerization of methyl methacrylate, which can obtain an acrylic sheet excellent in hardness, heat resistance, and chemical resistance, is preferable.

  As the polymerization catalyst, a known radical thermal polymerization initiator can be used, and examples thereof include peroxides such as benzoyl peroxide, p-chlorobenzoyl peroxide and diisopropyl peroxycarbonate, and azo compounds such as azobisisobutyronitrile. . The amount used is generally from 0.01 to 5% by weight, based on the total amount of the mixture. The heating temperature in the thermal polymerization is usually 40 to 200 ° C., and the polymerization time is usually about 30 minutes to 8 hours. In addition to thermal polymerization, a method of photopolymerization by adding a photopolymerization initiator or a sensitizer can also be employed.

  Examples of the method (3) include a method in which the diimonium compound of the present invention is dissolved in a binder resin and an organic solvent to form a paint, and a method in which the above compound is finely dispersed in the presence of the resin to form a water-based paint. . Among these, the method of dissolving the diimonium compound of the present invention in a binder resin and an organic solvent to form a paint includes, for example, aliphatic ester resins, acrylic resins, melamine resins, urethane resins, aromatic ester resins, polycarbonate resins, and polyvinyl resins. Resins, aliphatic polyolefin resins, aromatic polyolefin resins, polyvinyl alcohol resins, polyvinyl-modified resins, or the like, or copolymer resins thereof can be used as a binder.

  As the solvent, a halogen-based, alcohol-based, ketone-based, ester-based, aliphatic hydrocarbon-based, aromatic hydrocarbon-based, ether-based solvent, or a mixture thereof can be used. The concentration of the diimonium compound of the present invention is generally 0.1 to 30% by weight with respect to the binder resin, although it varies depending on the thickness of the coating to be produced, the absorption intensity, and the visible light transmittance.

A near-infrared absorption filter can be obtained by coating the thus-prepared coating material on a transparent resin film, transparent resin plate, transparent glass or the like with a spin coater, bar coater, roll coater, spray or the like.
In the method (4), as the resin for the adhesive, the resin for silicon, urethane, acrylic, etc., or the laminated glass such as polyvinyl butyral adhesive for laminated glass, ethylene-vinyl acetate adhesive, etc. Any known transparent adhesive can be used. Bonding transparent resin plates, resin plates and resin, resin plates and glass, resin films, resin films and glass, and glasses using an adhesive containing 0.1 to 30% by weight of the dimonium compound of the present invention. Then, a filter is produced.
In addition, at the time of kneading and mixing by each method, usual additives used for resin molding such as an ultraviolet absorber and a plasticizer may be added.

  Next, the near-infrared absorption filter of the present invention will be described. The resin layer containing the diimonium salt of the present invention may be provided on a substrate, or the substrate itself may be a layer made of a resin composition (or a cured product thereof) containing a near infrared absorbing compound. . The substrate is not particularly limited as long as it can be generally used for a near-infrared absorption filter, but a resin substrate is usually used. The thickness of the layer containing the diimonium compound of the present invention is usually about 0.1 μm to 10 mm, but is appropriately determined according to the purpose such as the near infrared cut rate. Further, the content of the diimonium compound of the present invention is also appropriately determined according to the target near-infrared cut rate. Examples of the resin that can be used include the same resins as those of the resin composition. When molded into a resin plate or a resin film, a resin that is as transparent as possible is preferable. Examples of the method for producing the near-infrared absorbing filter include the same methods as those for producing the fat composition.

  The infrared absorption filter of the present invention may contain only the diimonium compound of the formula (1) of the present invention as an infrared absorption compound, but it is also possible to use two or more kinds of the diimonium compounds of the present invention in combination. Alternatively, a near-infrared absorbing compound other than the diimonium compound of the present invention may be used in combination. Examples of other near infrared absorbing compounds that can be used in combination include phthalocyanine dyes, cyanine dyes, and dithiol nickel complexes. Examples of the inorganic metal near-infrared absorbing compound that can be used in combination include copper compounds such as metallic copper or copper sulfide, copper oxide, metal mixtures mainly composed of zinc oxide, tungsten compounds, ITO, and ATO. It is done.

In order to change the color tone of the filter, a dye having a visible region absorption (toning dye) may be added within a range that does not impair the effects of the present invention. It is also possible to produce a filter containing only the color-adjusting dye, and later attach the near-infrared absorption filter of the present invention.
When such a near-infrared absorption filter is used for the front plate of a plasma display, the higher the visible light transmittance, the better, and a transmittance of at least 40% or more, preferably 50% or more is required. The near infrared cut region is preferably 750 to 1200 nm, more preferably 800 to 1000 nm, and the average near infrared transmittance of the region is 50% or less, more preferably 30% or less, still more preferably 20% or less, Particularly preferably, it is desirable to be 10% or less.

The near-infrared absorbing filter of the present invention is not limited to uses such as a display front plate, but can also be used for filters and films that need to cut infrared rays, such as heat insulating films, optical products, and sunglasses.
The near-infrared absorption filter of the present invention is an excellent near-infrared absorption filter that has a very high transmittance in the visible light region, does not contain antimony or arsenic, is environmentally friendly, and absorbs a wide range in the near-infrared region. Moreover, it is excellent in stability as compared with conventional near-infrared absorption filters containing perchlorate ions, hexafluorophosphate ions, and borofluoride ions that do not contain antimony. Furthermore, the solubility is sufficient and the processability is also excellent. In particular, the near-infrared absorption filter of the present invention is very excellent in heat resistance, moisture heat resistance, and light resistance, and hardly undergoes a reaction such as decomposition by heat, so that a near-infrared absorption filter that hardly causes coloring in the visible part is obtained. Can do. Furthermore, since it has such characteristics, it can be suitably used for near-infrared absorbing filters and near-infrared absorbing films such as heat insulating films and sunglasses, and particularly suitable for near-infrared absorbing filters for plasma displays. is there.

Next, the optical information recording medium of the present invention will be described.
The optical information recording medium of the present invention has a recording layer on a substrate, and the recording layer contains the diimonium compound of the present invention. This recording layer may be composed of only a diimonium compound, or may be mixed with various additives such as a binder. In this case, information is recorded by the diimonium compound of the present invention.

Moreover, the light resistance of the optical information recording medium is obtained by including the mixture containing the diimonium compound of the present invention and the other organic dye in the recording layer of the optical information recording medium on which information is recorded by the organic dye. Can be improved. Examples of organic dyes used for recording information in such optical information recording media include cyanine dyes, squarylium dyes, indoaniline dyes, phthalocyanine dyes, azo dyes, merocyanine dyes, and polymethine dyes. Naphthoquinone dyes, pyrylium dyes, and the like.
In such a method, the diimonium compound of the present invention is generally used in an amount of 0.01 to 10 mol, preferably 0.03 to 3 mol, per 1 mol of these organic dyes.

  The optical information recording medium of the present invention comprises a substrate provided with a recording layer containing the diimonium compound of the present invention and, if desired, a dye other than this, and a reflective layer and a protective layer are provided as necessary. Any known substrate can be used. For example, a glass plate, a metal plate, a plastic plate or a film can be mentioned, and plastics for producing these include acrylic resin, polycarbonate resin, methacrylic resin, polysulfone resin, polyimide resin, amorphous polyolefin resin, polyester resin, polypropylene Examples thereof include resins. Examples of the shape of the substrate include various shapes such as a disk shape, a card shape, a sheet shape, and a roll film shape.

  A guide groove may be formed on a glass or plastic substrate to facilitate tracking during recording. The glass or plastic substrate may be provided with a subbing layer such as a plastic binder, inorganic oxide, or inorganic sulfide, and the subbing layer preferably has a lower thermal conductivity than the substrate.

The recording layer in the optical information recording medium of the present invention includes, for example, the diimonium compound of the present invention, and more preferably the diimonium compound of the present invention and other organic dyes in a known organic solvent such as tetrafluoropropanol (TFP), octane. Dissolve in fluoropentanol (OFP), diacetone alcohol, methanol, ethanol, butanol, methyl cellosolve, ethyl cellosolve, dichloroethane, isophorone, cyclohexanone, etc., add a binder as necessary, and add the solution to a spin coater or bar coater It can be obtained by coating on a substrate with a roll coater or the like. As other methods, it can also be obtained by a vacuum deposition method, a sputtering method, a doctor blade method, a casting method, or a dipping method in which a substrate is immersed in a solution. Here, acrylic resin, urethane resin, epoxy resin, or the like can be used as the binder.
The film thickness of the recording layer is preferably 0.01 μm to 5 μm, more preferably 0.02 μm to 3 μm in consideration of recording sensitivity and reflectance.

  In the optical information recording medium of the present invention, if necessary, an undercoat layer can be provided below the recording layer, and a protective layer can be provided on the recording layer, and a reflective layer can be provided between the recording layer and the protective layer. I can do it. When the reflective layer is provided, the reflective layer is composed of gold, silver, copper, aluminum, or the like, preferably gold, silver, or aluminum, and these metals may be used alone or as two or more alloys. Also good. This layer is formed by vacuum deposition, sputtering, ion plating, or the like. The thickness of such a reflective layer is 0.02 to 2 μm. The protective layer that may be provided on the reflective layer is usually formed by applying an ultraviolet curable resin by a spin coating method and then irradiating the ultraviolet ray to cure the coating film. In addition, an epoxy resin, an acrylic resin, a silicone resin, a urethane resin, or the like is also used as a protective film forming material. The thickness of such a protective film is usually 0.01 to 100 μm.

  The recording of information or the formation of images on the optical information recording medium of the present invention is performed with a focused spot-like high energy beam such as a laser, for example, a semiconductor laser, a helium-neon laser, a He-Cd laser, a YAG laser, or an Ar laser. Irradiating the recording layer through the substrate or from the opposite side of the substrate, information or image reading is performed by irradiating a low-power laser beam to reflect the pits and portions where no pits are formed. This is done by detecting the difference in light quantity or transmitted light quantity.

  The diimonium compound of the present invention has a maximum absorption wavelength of 900 nm or more, and a molar extinction coefficient of tens of thousands to hundreds of thousands. In addition, from the results of stability tests such as heat resistance, light resistance, and moist heat resistance, there is less discoloration compared to conventional ones, it is excellent in stability, and has sufficient solvent solubility than the solubility test, It can be used as an infrared absorber with good processability.

  The composition of the present invention, particularly the infrared absorption filter, has higher solubility and excellent processability than the near-infrared absorption filter using a conventional diimonium compound, and further has stability such as heat resistance, heat and humidity resistance, and light resistance. Is excellent. In particular, it is a near-infrared absorption filter excellent in heat resistance, moist heat resistance, and light resistance, in which reaction such as decomposition in these stability tests is unlikely to occur and the visible portion is hardly colored. Since it has such characteristics, it can be suitably used as a near-infrared absorption filter and a near-infrared absorption film such as a heat insulating film and sunglasses, and is particularly suitable for a near-infrared absorption filter for plasma display. It is.

  The optical information recording medium of the present invention is superior in light resistance stability as compared with a conventional optical information recording medium made of a diimonium compound. In addition, these compounds have sufficient solubility and excellent processability when preparing an optical information recording medium. Further, for example, when an organic dye thin film corresponding to a recording layer of an optical information recording medium contains these compounds as a light stabilizing material, an optical information recording medium in which durability during repeated reproduction and light stability is remarkably improved is provided. be able to.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the examples, “parts” and “%” are based on weight unless otherwise specified.

Example 1
(Synthesis of No. 1 compound in Table 1)
3 parts of N, N, N ′, N′-tetrakis (p-di (n-butyl) aminophenyl) -p-phenylenediamine was added to 16.5 parts of DMF, and the mixture was dissolved by heating at 60 ° C., and then DMF 16.5. 1.16 parts of silver nitrate dissolved in 2. parts and 2.19 parts of potassium bistrifluoromethanesulfonate imide were added and stirred with heating for 30 minutes. After the insoluble matter was filtered off, water was added to the reaction solution, and the precipitated crystals were filtered, washed with water and dried to obtain the desired compound No. 4.3 parts of 1 were obtained.
λmax 1102 nm (dichloromethane)
Melting point around 170 ° C .: thermal decomposition point (weight loss start temperature) around 280 ° C. (thermogravimetry and differential thermal analysis (TG-DTA))

Example 2
(Synthesis of compound No. 2 in Table 1)
In Example 1, instead of N, N, N ′, N′-tetrakis {p-di (n-butyl) aminophenyl} -p-phenylenediamine, N, N, N ′, N′-tetrakis {p- The reaction was the same except that di (i-butyl) aminophenyl} -p-phenylenediamine was used. 4.3 parts of compound 2 were obtained. λmax 1104nm (dichloromethane)
Melting point around 165 ° C .: thermal decomposition point (weight loss start temperature) around 282 ° C. (TG-DTA measurement)

Example 3
(Synthesis of compound No. 3 in Table 1)
In a solution of 0.58 parts of sodium nitrate in 3 parts of water, 3.28 parts of N, N, N ′, N′-tetrakis {p-di (cyanopropyl) aminophenyl} -p-phenylenediamine and DMF16. 5 parts were added. After the reaction solution was heated to 60 ° C., 1.16 parts of silver nitrate dissolved in 16.5 parts of DMF was added and stirred for 30 minutes. After insoluble components were filtered off, 2.19 parts of bistrifluoromethanesulfonic acid imide potassium salt was added to the reaction solution, stirred for 3 hours, and water was added. The precipitated crystals are filtered, washed with water and dried to obtain the desired compound No. 4.5 parts of 3 were obtained.
λmax 1064nm (dichloromethane)
Melting point around 180 ° C .: thermal decomposition point (weight reduction start temperature) around 282 ° C. (TG-DTA measurement)

Example 4
(Synthesis of compound No. 4 in Table 1)
In Example 1, instead of N, N, N ′, N′-tetrakis {p-di (n-butyl) aminophenyl} -p-phenylenediamine, N, N, N ′, N′-tetrakis {p- The reaction was the same except that di (i-amyl) aminophenyl} -p-phenylenediamine was used. 3.7 parts of compound 4 were obtained. λmax 1102 nm (dichloromethane)
Melting point around 175 ° C .: thermal decomposition point (weight loss start temperature) around 280 ° C. (TG-DTA measurement)

Example 5
(Synthesis of compound No. 9 in Table 1)
In Example 1, instead of N, N, N ′, N′-tetrakis {p-di (n-butyl) aminophenyl} -p-phenylenediamine, N, N, N ′, N′-tetrakis {p- The reaction was the same except that di (cyanobutyl) aminophenyl} -p-phenylenediamine was used. 4.1 parts of 9 compounds were obtained. λmax 1086 nm (dichloromethane)
Melting point around 145 ° C .: thermal decomposition point (weight loss start temperature) around 277 ° C. (TG-DTA measurement)

Example 6
(Synthesis of compound No. 12 in Table 1)
In Example 1, instead of N, N, N ′, N′-tetrakis {p-di (n-butyl) aminophenyl} -p-phenylenediamine, N, N, N ′, N′-tetrakis {p- Reacts in the same manner except that it was replaced with diethylaminophenyl} -p-phenylenediamine. 2.1 parts of 12 compounds were obtained. λmax 1084 nm (dichloromethane)
Melting point around 186 ° C .: thermal decomposition point (weight loss start temperature) around 278 ° C. (TG-DTA measurement)

Example 7
(Synthesis of compound No. 35 in Table 1)
In Example 1, instead of N, N, N ′, N′-tetrakis {p-di (n-butyl) aminophenyl} -p-phenylenediamine, N, N, N ′, N′-tetrakis {p- Aminophenyl} -p-phenylenediamine was reacted in the same manner except that it was replaced with a mixture of n-butyl derivative and 3-cyanopropyl derivative. 2.6 parts of 35 compounds were obtained.
λmax 1090nm (dichloromethane)
Melting point around 135 ° C .: Thermal decomposition point (weight loss start temperature) around 256 ° C. (TG-DTA measurement)

  Other compound examples can also be synthesized by oxidizing the corresponding phenylenediamine derivative with an oxidizing agent and reacting with the corresponding anion in the same manner as in Synthesis Examples 1 to 7.

Example 8
About the compound obtained in the said Example, the molar extinction coefficient ((epsilon)) in a dichloromethane was measured. (V-570 manufactured by JASCO Corporation)
The results are shown in Table 2.

Comparative Examples 1 and 2
1,5-Naphthalenedisulfonate of N, N, N ′, N′-tetrakis {p-di (n-butyl) aminophenyl} phenylenediimonium which is a compound described in Patent Document 2 (Patent Document 2, Examples) 1) (Comparative Example 1: Compound No. 151) and 1-hydroxy-2,5-naphthalenedisulfonate (Comparative Example 2: Compound No. 152) were similarly used in dichloromethane. The molar extinction coefficient (ε) of was measured. The results are shown in Table 2.

Table 2 (Molar extinction coefficient comparison test)
Compound No. Molar extinction coefficient (ε)
No. 1 108,000
No. 2 109,000
No. 3 109,000
No. 4 110,000
No. 9 109,000
No. 12 96,000
No. 151 (Comparative Example 1) 82,000
No. 152 (Comparative Example 2) 24,500

  It can be seen that the diimonium compound of the present invention has a high molar extinction coefficient of 96,000 or more.

Example 9 (Solubility of Diimonium Compound)
About the compound obtained in the said Example, it stirred at room temperature in methyl ethyl ketone (MEK) and toluene, and the solubility was determined. The results are shown in Table 3.

Comparative Examples 3 and 4
For comparison, N, N, N ′, N′-tetrakis {p-di (n-butyl) aminophenyl} phenylenediimonium hexafluoroantimonate (Comparative Example 3: The same applies to Compound No. 153) and N, N, N ′, N′-tetrakis {p-di (3-cyanopropyl) aminophenyl} phenylenediimonium hexafluoroantimonate (Comparative Example 4: Compound No. 154). Solubility was determined. The results are shown in Table 3.

Table 3 (Solubility comparison test) (%)
Compound No. MEK Toluene No. 1 20% 0.2%
No. 2 5% 0.04%
No. 3 2% Insoluble No. 3 4 10% 0.1%
No. 153 (Comparative Example 3) 4.5% Insoluble No. 153 154 (Comparative Example 4) Insoluble Insoluble

  As is clear from the above results, it can be seen that the diimonium compound of the present invention has improved solubility in commonly used solvents such as MEK and toluene as compared with derivatives having the same substituent.

Example 10 (Near-infrared absorption filter and wet heat stability test)
In 18.8 parts of MEK, 1.2 parts of each compound obtained in each of the above Examples was dissolved. To this solution, 80 parts of a resin solution obtained by adding 25 parts of acrylic resin (Dianar BR-80, manufactured by Mitsubishi Rayon Co., Ltd.) in 75 parts of MEK was mixed to obtain a coating solution. This was coated on a polyester film so as to have a thickness of 2 to 4 μm and dried at 80 ° C. to obtain a near-infrared absorbing filter of the present invention.
The obtained near-infrared absorption filter was left for 14 days in a thermo-hygrostat under conditions of 60 ° C. and 95% RH. Thereafter, the color of the filter was measured with a spectrophotometer (UV-2200, manufactured by Shimadzu Corporation), L ^* , a ^* , b ^* values were calculated, and stability was evaluated from changes in the b ^* values. . The lower the b ^* value, that is, the lower the absorption in the visible region, the better the near infrared absorption filter. Table 4 shows the results of the obtained moisture and heat resistance test. Table 4 shows the results of the obtained heat test.

Comparative Examples 5 and 6
For comparison, N, N, N ′, N′-tetrakis {p-di (n-butyl) aminophenyl} phenylenediimonium hexafluorophosphate which is a compound described in Patent Document 1 instead of the above compound (Comparative Example 5: Compound No. 155), N, N, N ′, N′-tetrakis {p-di (n-butyl) aminophenyl} phenylenediimonium borofluoride (Comparative Example 6: Compound No. 156) A filter was produced in the same manner as in Example 10 except that was used, evaluated in the same manner, and the results are shown in Table 4.

Table 4 (Moisture and heat resistance test)
b ^* Value Compound No. 14 days after initial Difference No. 1 3.5 5.3 1.8
No. 2 2.2 4.1 1.9
No. 3 3.6 6.1 2.5
No. 4 2.2 4.3 2.1
No. 9 2.4 4.3 1.9
No. 155 (Comparative Example 5) 2.9 9.0 6.1
No. 156 (Comparative Example 6) 3.5 14.3 10.8

Since the near-infrared absorption filter of the present invention containing these compounds has a small change in b ^* value relative to the comparative sample, it can be seen that it is excellent in stability under high temperature and high humidity conditions. In particular, those in which R _{1 to} R _{8 in} the above formula (1) are all alkyl groups branched at the terminals are low as b ^* values and are excellent as near infrared absorption filters.

Example 11 (Example of optical information recording medium)
No. obtained in Synthesis Example 1 0.02 part of compound 1 and 0.10 part of cyanine dye (OM-57, manufactured by Fuji Photo Film Co., Ltd.) were dissolved in 10 parts of tetrafluoropropanol and passed through a 0.2 μm filter to obtain a coating solution. 1 ml of this solution was dropped with a pipette onto a 5 inch polycarbonate resin substrate with a groove, and applied and dried with a spin coater to form an organic thin film recording layer. The maximum absorption wavelength of the coating film was 719 nm. Gold was deposited on the resulting coating film (by V-570 manufactured by JASCO Corporation) by the sputtering method to produce an optical information recording medium as a reflective layer. When the obtained optical information recording medium was evaluated with a CD-R recording / reproducing apparatus, recording and reproduction were possible. Thus, an optical information recording medium having excellent processability could be obtained, and there was no problem in recording and reproduction.

Example 12 (Light stability test of cyanine dye film)
In 15 parts of tetrafluoropropanol, 0.3 part of a cyanine dye (OM-57) was dissolved. 0.04 part of the compound No. 3 was added to prepare a coating solution. The obtained coating solution was spin-coated on a polycarbonate substrate to prepare a dye film. The obtained dye film was placed in a weatherometer (Ci4000 manufactured by Atlas Co., Ltd.) under the conditions of light source output: 0.36 W / m ² , bath temperature: 24 ° C., black panel temperature: 40 ° C., humidity: 30% RH. Light was irradiated from the side, and a light stability test was conducted in 50 hours. Thereafter, the residual ratio of the cyanine dye was measured with a spectrophotometer (V-570 manufactured by JASCO Corporation). The results are shown in Table 5.

Comparative Example 7
No. Except that tetrakis {p-di (n-butyl) aminophenyl} phenylenediimonium hexafluoroantimonate (Comparative Example 7: Compound No. 153), which is the compound described in Patent Document 3, was used instead of the compound of No. 1. Similarly, a dye film was prepared and evaluated, and the results are shown in Table 5.

Table 5 (Light stability test of cyanine dye film)
Cyanine pigment remaining rate (%)
Compound No. Initial 100 hours later 150 hours later 3 100 47 27
No. 153 (Comparative Example 7) 100 27 0

  As is clear from the above results, the light resistance of the cyanine dye can be greatly improved by containing the compound of the present invention.

Example 13 (Light stability test of diimonium compound thin film)
In 10 parts of tetrafluoropropanol, no. 0.1 parts of compound 3 was added to prepare a coating solution. The obtained coating liquid was spin-coated on a polycarbonate substrate to prepare a thin film of dimonium salt. The obtained thin film was subjected to the substrate side in a weatherometer (Ci4000 manufactured by Atlas Co., Ltd.) under the conditions of light source output: 0.36 W / m ² , bath temperature: 24 ° C., black panel temperature: 40 ° C., humidity: 30% RH. Were irradiated with light, and a light stability test was conducted in 50 hours. Thereafter, the residual ratio of the cyanine dye was measured with a spectrophotometer. The results are shown in Table 6.

Comparative Example 8
For comparison, no. Instead of the compound 1, tetrakis {p-di (n-butyl) aminophenyl} phenylenediimonium hexafluoride antimonate (Comparative Example 8: Compound No. 153) described in Patent Document 3 was used. Except for the above, a dye film was prepared and evaluated in the same manner, and the results are shown in Table 6.

Table 6 (Light stability test of diimonium compound thin film)
Residual rate of diimonium compound (%)
Compound No. Initial 100 hours later 150 hours later 3 100 88 86
No. 153 (Comparative Example 8) 100 81 76

  As is clear from the above results, the compound of the present invention has excellent light resistance when formed into a thin film.

Example 14 (Near-infrared absorbing filter and heat stability test)
A filter was produced in the same manner as in Example 10, and the obtained near-infrared absorption filter was left in an oven at 80 ° C. for 21 days. Thereafter, the color of the filter was measured with a spectrophotometer, L ^* , a ^* , b ^* values were calculated, and stability was evaluated from changes in the b ^* values. The lower the b ^* value, that is, the lower the absorption in the visible region, the better the near infrared absorption filter. Table 7 shows the results of the heat resistance test obtained.

Comparative Example 9
For comparison, N, N, N ′, N′-tetrakis {p-di (n-butyl) aminophenyl} phenylenediimonium hexafluoroantimonate instead of the above compound (Comparative Example 9: Compound No. 153) A filter was prepared in the same manner as in Example 4 except that was used, and evaluated in the same manner. The results are shown in Table 7.

Table 7 (Heat resistance stability test)
b ^* Value Compound No. Initial 14 days later Difference No. 1 3.5 5.3 1.8
No. 2 2.2 3.7 1.5
No. 4 2.4 3.8 1.6
No. 153 (Comparative Example 9) 2.5 4.4 1.9

Since the near-infrared absorption filter of the present invention has a small change in b ^* value relative to the comparative sample, it can be seen that it is excellent in stability under high temperature conditions. Among them, in the diimonium compound (1) of the present invention, those in which R ₁ to R ₈ are all alkyl groups branched at the terminal are smaller in b ^* value than the linear alkyl group, and the near infrared ray It turns out that it is more excellent as an absorption filter.

Example 15 (Synthesis Example 8)
(In Formula (1), Ring A and Ring B are substituted with hydrogen atoms, and R _{1 to} R ₈ are an n-butyl group and a cyanopropyl group (n-butyl group: cyanopropyl group) = (5: 3) (4: 4) (3: 5) (2: 6) (1: 7) in a ratio of 8%, 36%, 35%, 17%, 4%, R ₉ and Synthesis of compounds in which R ₁₀ is a trifluoromethane group)
In 16 parts of DMF, 5.3 parts of N, N, N ′, N′-tetrakis (aminophenyl) -p-phenylenediamine, 20 parts of potassium carbonate, 10 parts of potassium iodide, 6.2 parts of 1-bromobutane, chlorobuty 23.2 parts of nitrile was added and reacted at 90 ° C. for 3 hours and then at 130 ° C. for 1 hour. After cooling, the solution was filtered, and 40 parts of methanol was added to the reaction solution, followed by stirring at 5 ° C. or lower for 1 hour. The produced crystals were filtered, washed with methanol, and dried to obtain 7.2 parts of light brown crystals. When the obtained mixture was measured using LC (HP-1100 manufactured by Agilent) and a mass spectrometer (Micromass LCT), R _{1 to} R ₈ were an n-butyl group and a cyanopropyl group (n-butyl group: cyano). Propyl group) = (5: 3) (4: 4) (3: 5) (2: 6) (1: 7), the proportions being 8%, 36%, 35%, 17%, 4% Met.
Melting point (DSC) 144 ° C
6.3 parts of the mixture was dissolved in 30 parts of DMF and heated to 60 ° C. 4.57 parts of bistrifluoromethanesulfonic acid imide potassium salt was added to the reaction solution, and then 2.32 parts of silver nitrate dissolved in 30 parts of DMF was added and stirred for 30 minutes. After filtering the insoluble matter, water was added, and the precipitated crystals were filtered, washed with water and dried to obtain 3.5 parts of the desired compound.
λmax 1092nm (dichloromethane)

Example 16 (Synthesis Example 9)
(Synthesis of Compound No. 61 in Table 1)
In Example 1, the reaction was performed in the same manner except that bispentafluoroethanesulfonic acid imide potassium salt was used instead of bistrifluoromethanesulfonic acid imide potassium salt. 1.6 parts of 61 compounds were obtained.
λmax 1098 nm (dichloromethane)

Claims (15)

Diimonium compound represented by the following formula (1)

(In Formula (1), R _{1 to} R ₈ each independently represents an aliphatic hydrocarbon residue which may have a hydrogen atom or a substituent, and R ₉ and R ₁₀ each independently have a halogen atom. Each represents a good aliphatic hydrocarbon, and rings A and B may further have a substituent.) The diimonium compound according to claim 1, wherein R ₉ and R _{10 in} the formula (1) are aliphatic hydrocarbon residues having a fluorine atom. The diimonium compound according to claim 2, wherein R ₉ and R _{10 in} formula (1) are trifluoromethyl groups. The diimonium compound according to any one of claims 1 to 3, wherein at least one of R _{1 to} R _{8 in} the formula (1) is a linear or branched (C1-C6) alkyl group. The diimonium compound according to claim 4, wherein at least one of R _{1 to} R _{8 in} the formula (1) is a linear (C1-C3) alkyl group. The diimonium compound according to claim 4, wherein at least one of R _{1 to} R ₈ in formula (1) is a branched alkyl group. 7. The diimonium compound according to claim 6, wherein R _{1 to} R _{8 in} formula (1) are all alkyl groups branched at the ends. The diimonium compound according to claim 7, wherein R _{1 to} R _{8 in} the formula (1) are an iso-butyl group or an iso-amyl group. The substituent of the aliphatic hydrocarbon residue which may have a substituent of R _{1 to} R _{8 in} the formula (1) is a halogen atom, cyano group, nitro group, hydroxyl group, carboxyl group, carbonamido group, alkoxycarbonyl The diimonium compound according to any one of claims 1 to 3, which is a group, an acyl group, an aryl group, or an alkoxyl group. The diimonium compound according to claim 9, wherein R _{1 to} R _{8 in} formula (1) are all alkyl groups substituted with a cyano group. The diimonium compound according to claim 9, wherein at least one of R _{1 to} R ₈ is an alkyl group substituted with a cyano group, and at least one is an alkyl group. A composition comprising the diimonium compound according to any one of claims 1 to 11 and a resin. The near-infrared absorption filter which has a layer containing the diimonium compound as described in any one of Claims 1 thru | or 12. A plasma display comprising the near-infrared absorbing filter according to claim 13. An optical information recording medium comprising the recording layer containing the diimonium compound according to any one of claims 1 to 11.