JP5168917B2 - Near-infrared cut filter and manufacturing method thereof - Google Patents

Description

  The present invention relates to a near-infrared cut filter and a manufacturing method thereof. Specifically, the present invention relates to a near-infrared cut filter suitable for use in a solid-state imaging device and the like and a method for manufacturing the same, while being able to cut near-infrared sharply.

In recent years, CCDs and CMOS image sensors, which are solid-state image sensors for color images, have been used in video cameras, digital still cameras, mobile phones with camera functions, etc., and these solid-state image sensors are sensitive to near-infrared light at their light receiving parts. Therefore, it is necessary to perform visibility correction, and a near-infrared cut filter is often used. As the near-infrared cut filter, a near-infrared cut filter in which a transparent resin is used as a base material and a near-infrared absorbing dye is contained in the transparent resin is known as preferable because it is inexpensive and easy to process. (For example, refer to Patent Document 1).
In order to protect the surface of the near-infrared cut filter, generally, a protective film is laminated, and processing such as punching or incorporation into imaging device manufacture is performed. However, the adhesive strength of the protective film increases excessively depending on the storage environment until manufacture, making it difficult to peel off the protective film, and the near-infrared cut filter is damaged during peeling or the surface of the near-infrared cut filter after peeling. In addition, there is a problem that the adhesive layer of the protective film remains and deteriorates optical characteristics.

As a result of intensive studies in view of such circumstances, the present inventors can obtain a near-infrared cut filter having no adhesive layer remaining, focusing on the peeling force before and after exposure to moisture and heat resistance of the protective film. As a result, the present invention has been completed.
JP-A-6-200113

  The present invention is excellent in near-infrared cutting ability and does not cause damage or deterioration of optical characteristics even when incorporated in a solid-state image sensor. In particular, the near-infrared cut that can be suitably used for correcting the visibility of a solid-state image sensor such as a CCD or CMOS. The problem is to obtain a filter.

Near-infrared cut filter according to the present invention,
It has a structure in which a protective film is further laminated on a laminate having a cyclic olefin-based resin substrate and a near-infrared reflective film, the peeling force from the laminate surface of the protective film, and a temperature of 85 ° C. and a humidity of 85%. The peeling force after storage for 240 hours is 0.5N or less.
The near-infrared cut filter of the present invention has a structure in which the laminate has a structure in which a near-infrared reflective film is laminated on both sides of a cyclic olefin resin substrate, and a protective film is further laminated on both sides of the laminate. It is preferable to have.
Furthermore, in the method for producing a near-infrared cut filter of the present invention, a cyclic olefin-based resin substrate and a near-infrared reflective film are laminated to form a laminated body. A protective film having a peeling force of 0.5 N or less after being stored for 240 hours under the condition of ° C. and humidity of 85% is further laminated.

  According to the present invention, near-infrared cutting ability is excellent, and even when incorporated in a solid-state imaging device, warpage and optical characteristics are not deteriorated. Particularly, it is suitable for use in correcting the visibility of a solid-state imaging device such as a CCD or CMOS. An infrared cut filter can be manufactured.

Hereinafter, the present invention will be specifically described.
[Cyclic olefin resin substrate]
In the near-infrared cut filter according to the present invention, a substrate made of a cyclic olefin resin is used as a transparent substrate.
The cyclic olefin resin (hereinafter also referred to as “cyclic olefin resin (A)”) is a cyclic olefin represented by the following formula (I) (hereinafter also referred to as “cyclic olefin (I)”). ) Polymers.

(In formula (I), R ^{1 to} R ⁴ are each independently a hydrogen atom, a halogen atom or a monovalent organic group, and R ¹ and R ² , or R ³ and R ⁴ are combined to form 2 R ¹ or R ² and R ³ or R ⁴ may be bonded to each other to form a monocyclic structure or a polycyclic structure, where m is 0 or positive An integer, and p is 0 or a positive integer.)

As a more specific cyclic olefin resin (A),
(1) Ring-opening polymer of cyclic olefin (I) (hereinafter also referred to as “polymer (1)”)
(2) Ring-opening copolymer of cyclic olefin (I) and copolymerizable monomer (hereinafter also referred to as “polymer (2)”)
(3) Hydrogenated (co) polymer of polymer (1) or polymer (2) (hereinafter also referred to as “polymer (3)”)
(4) Polymer (1) or polymer (2) cyclized by Friedel-Craft reaction and then hydrogenated (co) polymer (hereinafter also referred to as “polymer (4)”)
(5) Saturated copolymer of cyclic olefin (I) and unsaturated double bond-containing compound (hereinafter also referred to as “polymer (5)”)
(6) Addition type (co) polymer of cyclic olefin (I) and at least one monomer selected from vinyl cyclic hydrocarbon monomers and cyclopentadiene monomers, and hydrogenation thereof ( Co) polymer (hereinafter also referred to as “polymer (6)”)
(7) Alternating copolymer of cyclic olefin (I) and acrylate (hereinafter also referred to as “polymer (7)”)
Is mentioned. Of these, the polymer (3) is particularly preferably used in terms of excellent optical characteristics and the like.

<Cyclic olefin (I)>
Examples of the monovalent organic group in the above formula (I) include C1-C30 hydrocarbon groups and monovalent polar groups other than hydrocarbon groups. Examples of the monovalent polar group include a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, an allyloxycarbonyl group, an amino group, an amide group, and a cyano group. These polar groups are bonded via a linking group such as a methylene group. You may do it. Moreover, the hydrocarbon group etc. which couple | bonded through the coupling group which consists of divalent organic groups, such as a carbonyl group, an ether group, a silyl ether group, a thioether group, and an imino group, are also mentioned as a polar group. Of these polar groups, a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, and an allyloxycarbonyl group are preferable, and an alkoxycarbonyl group and an allyloxycarbonyl group are particularly preferable.

The cyclic olefin represented by the above formula (I) may be used alone or in combination of two or more.
Examples of the cyclic olefin represented by the formula (I) include, but are not limited to, the following compounds.
Bicyclo [2.2.1] hept-2-ene,
Tricyclo [4.3.0.1 ^2,5 ] -8-decene,
Tricyclo [4.4.0.1 ^2,5 ] -3-undecene,
Tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
Pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13 ] -4-pentadecene,
5-methylbicyclo [2.2.1] hept-2-ene,
5-ethylbicyclo [2.2.1] hept-2-ene,
5-methoxycarbonylbicyclo [2.2.1] hept-2-ene,
5-methyl-5-methoxycarbonylbicyclo [2.2.1] hept-2-ene,
5-cyanobicyclo [2.2.1] hept-2-ene,
8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-ethoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-n-propoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-Isopropoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-n-butoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-methyl-8-ethoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-methyl-8-n-propoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-methyl-8-isopropoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-methyl-8-n-butoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
5-ethylidenebicyclo [2.2.1] hept-2-ene,
8-ethylidenetetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
5-phenylbicyclo [2.2.1] hept-2-ene,
8-phenyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
5-fluorobicyclo [2.2.1] hept-2-ene,
5-fluoromethylbicyclo [2.2.1] hept-2-ene,
5-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5-pentafluoroethylbicyclo [2.2.1] hept-2-ene,
5,5-difluorobicyclo [2.2.1] hept-2-ene,
5,6-difluorobicyclo [2.2.1] hept-2-ene,
5,5-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5-methyl-5-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5,5,6-trifluorobicyclo [2.2.1] hept-2-ene,
5,5,6-tris (fluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5,6,6-tetrafluorobicyclo [2.2.1] hept-2-ene,
5,5,6,6-tetrakis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5-difluoro-6,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,6-difluoro-5,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5,6-trifluoro-5-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5-fluoro-5-pentafluoroethyl-6,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,6-difluoro-5-heptafluoro-iso-propyl-6-trifluoromethylbicyclo [2.2.1] hept-2-ene,
5-chloro-5,6,6-trifluorobicyclo [2.2.1] hept-2-ene,
5,6-dichloro-5,6-bis (trifluoromethyl) bicyclo [2.2.1] hept-2-ene,
5,5,6-trifluoro-6-trifluoromethoxybicyclo [2.2.1] hept-2-ene,
5,5,6-trifluoro-6-heptafluoropropoxybicyclo [2.2.1] hept-2-ene,

8-fluorotetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-fluoromethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-difluoromethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-trifluoromethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-pentafluoroethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8,8-difluorotetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8,9-difluorotetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8,8-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8,9-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-methyl-8-trifluoromethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8,8,9-trifluorotetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8,8,9-tris (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8,8,9,9-tetrafluorotetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8,8,9,9-tetrakis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8,8-difluoro-9,9-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8,9-difluoro-8,9-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8,8,9-trifluoro-9-trifluoromethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8,8,9-trifluoro-9-trifluoromethoxytetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8,8,9-trifluoro-9-pentafluoropropoxytetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-fluoro-8-pentafluoroethyl-9,9-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8,9-difluoro-8-heptafluoroiso-propyl-9-trifluoromethyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-chloro-8,9,9-trifluorotetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8,9-dichloro-8,9-bis (trifluoromethyl) tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8- (2,2,2-trifluoroethoxycarbonyl) tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene,
8-methyl-8- (2,2,2-trifluoroethoxycarbonyl) tetracyclo [4.4.0.1 ^2,5 . ^{17, 10} ] -3-dodecene and the like.

Among such cyclic olefins, in the above formula (I), R ¹ and R ³ each independently represent a hydrogen atom or a carbon number of preferably 1 to 10, more preferably 1 to 4, particularly preferably 1 or 2. A hydrocarbon group, preferably an alkyl group, particularly preferably a methyl group; R ² and R ⁴ are each independently a hydrogen atom or a monovalent organic group, and at least one of R ² and R ⁴ is A hydrogen atom or the above-mentioned monovalent polar group; m is preferably an integer of 0 to 3, p is preferably an integer of 0 to 3, more preferably m + p is 0 to 4, and particularly preferably m + p is 0 to 2. And most preferred is a cyclic olefin in which m = 1 and p = 0. Cyclic olefins with m = 1 and p = 0 are most preferable in that a cyclic olefin-based resin having a high glass transition temperature and excellent mechanical strength can be obtained.

Furthermore, the cyclic olefin in which at least one of R ² and R ⁴ is a polar group represented by the following formula (II) has high glass transition temperature, low hygroscopicity, and excellent adhesion to various materials. It is preferable at the point from which a cyclic olefin resin is obtained.
_{- (CH 2) n COOR (} II)
In the formula (II), R is preferably a hydrocarbon group having 1 to 12 carbon atoms, more preferably 1 to 4 carbon atoms, particularly preferably 1 or 2, and preferably an alkyl group. Further, n is usually 0 to 5, and a cyclic olefin having a smaller value of n is preferable because a cyclic olefin-based resin having a high glass transition temperature is obtained, and a cyclic olefin having n of 0 is easy to synthesize. Is particularly preferable.
In particular, the polar group represented by the above formula (II) is bonded to the carbon atom to which R ¹ or R ³ which is an alkyl group is bonded, thereby obtaining a cyclic olefin resin having low hygroscopicity. This is preferable.

Polymer (1) and polymer (2):
The polymer (1) and the polymer (2) are obtained by ring-opening polymerization of the cyclic olefin or ring-opening copolymerization of the cyclic olefin and a copolymerizable monomer in the presence of a metathesis catalyst. Can be obtained.

<Copolymerizable monomer>
Examples of the copolymerizable monomer used in the polymer (2) include cycloolefin, and a cycloolefin having 4 to 20 carbon atoms, more preferably 5 to 12 carbon atoms is desirable. More specifically, cyclobutene, cyclopentene, cycloheptene, cyclooctene, dicyclopentadiene and the like can be mentioned. These cycloolefins may be used singly or in combination of two or more. The use ratio of the cyclic olefin to the copolymerizable monomer is determined by weight ratio (cyclic olefin / copolymerizable monomer). 100/0 to 50/50, and preferably 100/0 to 60/40. “Cyclic olefin / copolymerizable monomer = 100/0” means the proportion of cyclic olefin used in homopolymerization.

<Catalyst for ring-opening polymerization>
The metathesis catalyst used in the ring-opening (co) polymerization reaction is a catalyst comprising a combination of the following compound (a) and compound (b).
(A) A compound containing at least one element selected from W, Mo and Re.
(B) Deming periodic table group IA elements (for example, Li, Na, K, etc.), group IIA elements (for example, Mg, Ca, etc.), group IIB elements (for example, Zn, Cd, Hg, etc.), group IIIA A compound containing at least one element selected from an element (eg, B, Al, etc.), a group IVA element (eg, Si, Sn, Pb, etc.) and a group IVB element (eg, Ti, Zr, etc.), At least one compound selected from compounds having at least one bond between an element and carbon or at least one bond between the element and hydrogen.
The metathesis catalyst may contain an additive (c) described later in order to increase its activity.

Specific examples of the compound (a) include WCl ₆ , MoCl ₆ , ReOCl _{3 and the} like, described in JP-A No. 1-132626, page 8, upper left column, line 6 to page 8, upper right column, line 17. Can be mentioned.
Specific examples of the compound _{(b), n-C 4} H 9 Li, (C 2 H 5) 3 Al, (C 2 H 5) 2 AlCl, (C 2 H 5) 1.5 AlCl 1.5 , (C ₂ H ₅ ) AlCl ₂ , methylalumoxane, LiH, etc., the compounds described in JP-A-1-132626, page 8, upper right column, line 18 to page 8, lower right column, line 3 Can do.
As the additive (c), alcohols, aldehydes, ketones, amines and the like can be preferably used, and further, JP-A-1-132626, page 8, lower right column, lines 16 to 9. The compounds described in the upper left column, line 17 of the page can also be used.
The ratio of the said compound (a) and a compound (b) is metal atom ratio [(a) :( b)], and is usually 1: 1-1: 50, Preferably it is 1: 2-1: 30.
The ratio of the additive (c) to the compound (a) is a molar ratio [(c) :( a)] and is usually 0.005: 1 to 15: 1, preferably 0.05: 1 to 7: 1.
The amount of the metathesis catalyst used is such that the molar ratio of the compound (a) to the cyclic olefin [(a): cyclic olefin] is usually from 1: 500 to 1: 50,000, preferably from 1: 1,000 to 1:10. , 000.

<Solvent for polymerization reaction>
In the ring-opening (co) polymerization reaction, the solvent is used as a solvent constituting a molecular weight modifier solution described later, a solvent for a cyclic olefin and / or a metathesis catalyst. Examples of such solvents include alkanes such as pentane, hexane, heptane, octane, nonane and decane; cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin and norbornane; benzene, toluene, xylene, ethylbenzene, Aromatic hydrocarbons such as cumene; halogenated alkanes such as chlorobutane, bromohexane, methylene chloride, dichloroethane, hexamethylene dibromide, chloroform, tetrachloroethylene; aryl halides such as chlorobenzene; ethyl acetate, n-butyl acetate, iso- Saturated carboxylic acid esters such as butyl, methyl propionate, and dimethoxyethane; and ethers such as dibutyl ether, tetrahydrofuran, and dimethoxyethane. That. These solvents can be used alone or in combination. Of these, aromatic hydrocarbons are preferred.
The amount of the solvent used is desirably such that the weight ratio of the solvent to the cyclic olefin (solvent: cyclic olefin) is usually 1: 1 to 10: 1, preferably 1: 1 to 5: 1.

<Molecular weight regulator>
The molecular weight of the resulting ring-opening (co) polymer can be adjusted by the polymerization temperature, the type of catalyst and the type of solvent, but can also be adjusted by allowing a molecular weight regulator to coexist in the reaction system. .
Suitable molecular weight regulators include, for example, α-olefins such as ethylene, propene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, and styrene. Of these, 1-butene and 1-hexene are particularly preferable. These molecular weight regulators can be used alone or in admixture of two or more.
The usage-amount of a molecular weight regulator is 0.005-0.6 mol normally with respect to 1 mol of cyclic olefins used for ring-opening polymerization reaction, Preferably it is 0.01-0.5 mol.
The ring-opening copolymer can be obtained by ring-opening copolymerization of a cyclic olefin and a copolymerizable monomer, and further includes conjugated diene compounds such as polybutadiene and polyisoprene, styrene-butadiene copolymer, Cyclic olefins may be subjected to ring-opening copolymerization in the presence of an unsaturated hydrocarbon polymer containing two or more carbon-carbon double bonds in the main chain such as an ethylene-nonconjugated diene copolymer or polynorbornene. .

(3) Hydrogenated (co) polymer:
The ring-opening (co) polymer can be used as it is, but the hydrogenated (co) polymer (3) obtained by further hydrogenation thereof is useful as a resin having excellent impact resistance. .
In the hydrogenation reaction, a hydrogenation catalyst is added to an ordinary method, that is, a solution containing a ring-opening (co) polymer, and hydrogen gas at normal pressure to 300 atm, preferably 3 to 200 atm, is added thereto at 0 to 200 ° C. , Preferably, it can be carried out by acting at 20 to 180 ° C.

<Hydrogenation catalyst>
As said hydrogenation catalyst, the catalyst used for the hydrogenation reaction of a normal olefinic compound can be used. Examples of the hydrogenation catalyst include a heterogeneous catalyst and a homogeneous catalyst.
Examples of the heterogeneous catalyst include a solid catalyst in which a noble metal catalyst material such as palladium, platinum, nickel, rhodium, and ruthenium is supported on a carrier such as carbon, silica, alumina, and titania. Homogeneous catalysts include nickel naphthenate / triethylaluminum, nickel acetylacetonate / triethylaluminum, cobalt octenoate / n-butyllithium, titanocene dichloride / diethylaluminum monochloride, rhodium acetate, chlorotris (triphenylphosphine) rhodium, dichloro Examples thereof include tris (triphenylphosphine) ruthenium, chlorohydrocarbonyltris (triphenylphosphine) ruthenium, dichlorocarbonyltris (triphenylphosphine) ruthenium, and the like. The form of these catalysts may be powder or granular.
In these hydrogenation catalysts, the weight ratio of the ring-opening (co) polymer to the hydrogenation catalyst (ring-opening (co) polymer: hydrogenation catalyst) is 1: 1 × 10 ⁻⁶ to 1: 2. It is preferable to use in proportions.
The hydrogenated (co) polymer (3) has excellent thermal stability, and its characteristics are not deteriorated even by heating during molding or use as a product.
The hydrogenation rate of the hydrogenated (co) polymer (3) is usually 50% or more, preferably 70% or more, more preferably 90% or more, particularly preferably as measured by ¹ H-NMR under the condition of 500 MHz. 98% or more, most preferably 99% or more. The higher the hydrogenation rate, the better the stability against heat and light, and it is possible to obtain a light diffusing plate having stable characteristics over a long period of time.
The hydrogenated (co) polymer (3) preferably has a gel content of 5% by weight or less, particularly preferably 1% by weight or less.

(4) Hydrogenated (co) polymer:
The hydrogenated (co) polymer (4) can be obtained by cyclizing the ring-opened (co) polymer of (1) or (2) by Friedel-Craft reaction and then hydrogenating it.
The method for cyclizing the ring-opened (co) polymer by Friedel-Craft reaction is not particularly limited, and for example, a known method using an acidic compound described in JP-A No. 50-154399 can be employed.
Specific examples of the acidic compound include Lewis acids such as AlCl ₃ , BF ₃ , FeCl ₃ , Al ₂ O ₃ , HCl, CH ₃ ClCOOH, zeolite, activated clay, and Bronsted acid.
The cyclized ring-opening (co) polymer can be hydrogenated in the same manner as the hydrogenation reaction of the ring-opening (co) polymer.

(5) Saturated copolymer:
The saturated copolymer (5) is obtained by addition polymerization of an unsaturated double bond-containing compound such as an olefinic compound such as ethylene, propylene, and butene to the cyclic olefin in the presence of an addition polymerization catalyst. Can be obtained. A conventionally known method can be applied to the addition polymerization method.
The use amount of the unsaturated double bond-containing compound is preferably 90/10 to 40/60 in terms of the weight ratio of the cyclic olefin to the unsaturated double bond-containing compound (cyclic olefin / unsaturated double bond-containing compound). 85/15 to 50/50 is more preferable. However, the total weight of the cyclic olefin and the unsaturated double bond-containing compound is 100.

(6) Addition type (co) polymer and hydrogenated (co) polymer thereof:
The addition type (co) polymer (6) is obtained by subjecting the cyclic olefin to addition polymerization of at least one monomer selected from a vinyl cyclic hydrocarbon monomer and a cyclopentadiene monomer. Can be obtained.
Examples of the vinyl cyclic hydrocarbon monomers include vinyl cycloalkene monomers, vinyl cycloalkane monomers, styrene monomers, terpene monomers, and the like. Examples of the cyclopentadiene monomer include cyclopentadiene, 1-methylcyclopentadiene, 2-methylcyclopentadiene, 2-ethylcyclopentadiene, 5-methylcyclopentadiene, and 5,5-methylcyclopentadiene. Can be mentioned.
The above addition polymerization reaction can be carried out in the same manner as the addition polymerization reaction in the saturated copolymer (5).
The hydrogenation (co) polymer of the addition type (co) polymer (6) is obtained by subjecting the addition type (co) polymer (6) to the same method as the hydrogenation (co) polymer (3). It can be obtained by hydrogenation.

(7) Alternating copolymer:
The alternating copolymer (7) can be obtained by radical polymerization of the cyclic olefin and acrylate in the presence of a Lewis acid or the like. The “alternate copolymer” in the present invention is a copolymer in which structural units derived from cyclic olefins are not adjacent to each other, that is, a structural unit derived from acrylate is always adjacent to a structural unit derived from cyclic olefin. It means a copolymer that is bonded. However, the acrylate-derived structural units may be present adjacent to each other.

  The glass transition temperature (Tg) of the cyclic olefin resin (A) is usually 130 ° C. or higher, preferably 130 to 350 ° C., more preferably 130 to 250 ° C., and particularly preferably 140 to 200 ° C. Resins with a Tg in the above range are not easily deformed even when used under high temperature conditions or during secondary processing involving heating such as coating and printing, and are excellent in molding processability, and the resin deteriorates due to heat during the molding process. Is less likely to occur.

<Additives>
The cyclic olefin resin used in the present invention can be used by further containing additives such as a near-infrared absorber, an antioxidant, and an ultraviolet absorber.

《Near-infrared absorber》
As the near infrared absorber, for example, a metal complex compound that absorbs near infrared rays can be used. The metal complex compound that absorbs near infrared rays used in the present invention has a spectral transmittance of 60% or less, preferably 30 when measured in an optical path length of 1 cm at a wavelength of 800 to 1000 nm when dissolved in a good solvent. A compound having a concentration range of not more than% is desirable. Further, depending on applications such as a front plate for PDP, in the so-called visible light region having a wavelength of 400 to 700 nm, the total light transmittance measured under the above conditions may be required to be 50% or more, preferably 65% or more. is there.

  As the compound, any metal complex compound that acts as a dye that absorbs near infrared rays can be used, and examples thereof include a phthalocyanine compound, a naphthalocyanine compound, and a dithiol metal complex compound. Specifically, for example, JP-A-8-225752, JP-A-8-253893, JP-A-9-111138, JP-A-9-157536, JP-A-9-176501, JP-A-9 -263658, JP-A 2000-212546, JP-A 2002-200711 and the like, and metal complex compounds whose structures and production methods are disclosed. Further, for example, CIR-1080, CIR-1081 (manufactured by Nippon Carlit), YKR-3080, YKR-3081 (manufactured by Yamamoto Kasei), eXcolor IR-10, IR-12, IR-14 (manufactured by Nippon Shokubai), Commercial products such as phthalocyanine compounds such as SIR-128, SIR-130, SIR-159, PA-1001, and PA-1005 (manufactured by Mitsui Chemicals Fine) can also be used.

  In the present invention, a metal ion and a chelate-forming compound are added independently, and the metal ion and the chelate-forming compound react to form a metal complex compound that absorbs near infrared rays, that is, a specific dye. May be. Examples of the specific dye include a reaction product of a phosphate ester compound and copper ions described in JP-A-6-118288.

  Furthermore, the compound in the present invention can also include a compound in which the polar group in the cyclic olefin resin used in the present invention and a metal ion form a complex and have near infrared absorption ability.

  In the present invention, the near-infrared absorber is appropriately selected according to the desired properties, but is usually 0.01 to 20.0 parts by weight, preferably 100 to 2 parts by weight, preferably 100 parts by weight of the cyclic olefin resin used in the present invention. It is 0.02-10.0 weight part, More preferably, it is 0.05-5.0 weight part. When the amount used is within the above range, a near-infrared cut filter excellent in visible light transmittance can be obtained.

《Other additives》
In the present invention, additives such as an antioxidant and an ultraviolet absorber can be further added to the cyclic olefin-based resin as long as the effects of the present invention are not impaired.

  Examples of the antioxidant include 2,6-di-t-butyl-4-methylphenol, 2,2′-dioxy-3,3′-di-t-butyl-5,5′-dimethyldiphenylmethane, tetrakis [ And methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane.

Examples of the ultraviolet absorber include 2,4-dihydroxybenzophenone and 2-hydroxy-4-methoxybenzophenone.
Moreover, when manufacturing a cyclic olefin-type resin substrate by the solution casting method mentioned later, manufacture of this board | substrate can be made easy by adding a leveling agent and an antifoamer.

  In addition, when forming a board | substrate, these additives may be mixed with cyclic olefin resin, and may be previously mix | blended by adding when manufacturing cyclic olefin resin. The addition amount is appropriately selected according to the desired properties, but is usually 0.01 to 5.0 parts by weight, preferably 0.05 to 2 parts per 100 parts by weight of the cyclic olefin resin. 0.0 part by weight is desirable.

<Method for Producing Cyclic Olefin Resin Substrate>
The transparent substrate made of cyclic olefin resin used in the present invention can be molded by melt molding or by a casting (cast molding) method.

<Melt molding>
The cyclic olefin resin substrate used in the present invention can be obtained by directly melt-molding a cyclic olefin resin.
When a resin composition containing a cyclic olefin-based resin and an additive such as a near infrared absorber is melt-molded, for example, the resin and an additive such as a near infrared absorber are melt-kneaded. It can be produced by a method of melt-molding the obtained pellets, a method of melt-molding pellets obtained by removing the solvent from the liquid resin composition containing the resin, additives and solvent.
Examples of the melt molding method include injection molding, melt extrusion molding, and blow molding.

"casting"
The cyclic olefin resin substrate used in the present invention is a liquid resin composition obtained by dissolving a resin in a solvent, or a liquid resin composition containing an additive such as a resin, a near infrared absorber, and a solvent on an appropriate base material. It can also be produced by removing the solvent by casting. For example, the substrate is obtained by applying the above-mentioned liquid resin composition on a base material such as a steel belt, a steel drum, or a polyester film, drying the solvent, and then peeling the coating film from the base material. Can do. In addition, the substrate can be formed on the original optical component by coating the above-mentioned liquid composition on an optical component made of glass, quartz or transparent plastic and drying the solvent.
The amount of residual solvent in the substrate obtained by the above method should be as small as possible, and is usually 3% by weight or less, preferably 1% by weight or less, more preferably 0.5% by weight or less. If the amount of residual solvent exceeds the above range, the resin substrate may be deformed over time or the characteristics may change over time, and the desired function may not be exhibited.

<< Performance of Cyclic Olefin Resin Substrate >>
The saturated water absorption of the substrate obtained as described above is usually 2.0% by weight or less, preferably 1.0% by weight or less, and more preferably 0.8% by weight or less. When the saturated water absorption rate exceeds the above range, there may be a problem in durability such that the resin substrate obtained from the resin is subject to water absorption (wet) deformation over time depending on the environment in which it is used. The saturated water absorption is a value obtained by immersing in 23 ° C. water for 1 week and measuring the increased weight according to ASTM D570.
The thickness of the substrate is usually 0.05 to 1.0 mm, preferably 0.08 to 0.5 mm, particularly preferably 0.1 to 0.3 mm.
With such a thickness, the near-infrared cut filter can be reduced in weight and thickness, and as a near-infrared cut filter for correcting the visibility of a solid-state image sensor, in particular, the translucent of the package for housing the solid-state image sensor It can be suitably used as a sex lid.

[Near-infrared reflective film]
The near-infrared cut filter according to the present invention has a structure in which a near-infrared reflective film is laminated on the above-described cyclic olefin resin substrate. As the near-infrared reflective film, a dielectric multilayer film is preferably used, and in particular, dielectric layers A and dielectric layers B having a refractive index higher than that of the dielectric layer A are alternately laminated. A near-infrared reflective film made of a dielectric multilayer film is preferably used. By having such a dielectric multilayer film on at least one surface of the transparent substrate, a near-infrared cut filter having an excellent ability to reflect near-infrared light can be obtained.

<Dielectric layer A>
As a material constituting the dielectric layer A, a material having a refractive index of 1.6 or less can be normally used, and a material having a refractive index range of 1.2 to 1.6 is preferably selected.
Examples of these materials include silica, alumina, lanthanum fluoride, magnesium fluoride, and aluminum hexafluoride sodium.

<Dielectric layer B>
As a material constituting the dielectric layer B, a material having a refractive index of 1.7 or more can be used, and a material having a refractive index range of 1.7 to 2.5 is preferably selected.
Examples of these materials include titanium oxide, zirconium oxide, tantalum pentoxide, niobium pentoxide, lanthanum oxide, yttrium oxide, zinc oxide, zinc sulfide, indium oxide as a main component, and small amounts of titanium oxide, tin oxide, cerium oxide, and the like. The thing etc. which were made to contain are mentioned.

<Lamination method>
The method of laminating the dielectric layer A and the dielectric layer B is not particularly limited as long as a dielectric multilayer film in which these material layers are laminated is formed. For example, a CVD method, a sputtering method, a vacuum deposition method, etc. Thus, a dielectric multilayer film can be formed by alternately laminating the dielectric layers A and B.
The thicknesses of the dielectric layer A and the dielectric layer B are usually 0.1λ to 0.5λ of the near infrared wavelength λ (nm) to be blocked. When the thickness is out of the above range, the product (n × d) of the refractive index (n) and the film thickness (d) is significantly different from the optical film thickness calculated by λ / 4, and the optical characteristics of reflection and refraction are different. The relationship is broken, and control for blocking / transmitting a specific wavelength tends to be impossible.
When the dielectric multilayer film has the dielectric multilayer film only on one surface of the cyclic olefin-based resin substrate, it is usually in the range of 10 to 80 layers, and preferably in the range of 25 to 50 layers. . On the other hand, when the dielectric layer film is provided on both sides of the substrate, the number of laminations of the dielectric layers is generally in the range of 10 to 80 layers, preferably in the range of 25 to 50 layers as the whole number of laminations on both sides of the substrate. It is.

  Moreover, when using the cyclic olefin-type resin containing a near-infrared absorber as a board | substrate, when it has the said dielectric multilayer film only in one surface of a board | substrate, the lamination | stacking number in the said dielectric multilayer film is 5-40. Layer, preferably 10 to 30 layers, and when the dielectric layer film is provided on both sides of the substrate, the number of laminated layers of the dielectric layer is 5 to 40 layers as the whole number of laminated layers on both sides of the substrate, Preferably it can be 10-30 layers. When a cyclic olefin-based resin containing a near-infrared absorber is used as a substrate, productivity can be further improved and the dielectric multilayer film can be made difficult to break.

<Specific function membrane>
The near-infrared cut filter according to the present invention may use at least one functional film (hereinafter also referred to as “specific functional film”) selected from an equivalent refractive index film, an antireflection film, and a hard coat film.

  An equivalent refractive index film is a film having substantially the same equivalent refractive index as that of the transparent substrate. Examples of these equivalent refractive index films include a symmetrical three-layer film centered on an alumina layer composed of three layers of silica layer / alumina layer / silica layer. When the symmetric three-layer film is used as an equivalent refractive index film, the refractive index can be made substantially the same as that of the transparent substrate by adjusting the film thickness of each layer.

  The antireflection film refers to a film having a function of improving the transmittance by preventing reflection of light incident on the near-infrared cut filter according to the present invention and efficiently using incident light. Examples of the material that can be used as the antireflection film include zirconium oxide, alumina, and magnesium fluoride. Examples of the antireflection film include a single layer made of any one of these materials, or a multilayer film in which a plurality of layers made of these materials are combined.

The hard coat film is a film having a high hardness and having a function of improving the scratch resistance of the near-infrared cut filter according to the present invention.
Examples of materials that can be used for the hard coat film include organic hard coat materials, acrylate hard coat materials, oxetane hard coat materials, and the like as organic materials. Examples of the inorganic material include a water-based silicate hard coat material and a water-based alumina hard coat material. In addition, organic-inorganic hybrid hard coat materials and the like, such as a combination of the above materials, can also be mentioned.

  The method for forming these specific function films is not particularly limited as long as the specific function film is formed. For example, the raw material is formed by a CVD method, a sputtering method, a vacuum deposition method, or a liquid containing the raw material. It can be obtained by coating the composition and drying it to form a film.

[Configuration of laminate (near infrared cut filter)]
The laminate constituting the near-infrared cut filter according to the present invention has a near-infrared reflective film composed of the dielectric multilayer film on at least one surface, preferably both surfaces, of the cyclic olefin resin substrate. When the dielectric multilayer film exists only on one surface of the substrate, at least one kind of the specific function film may be provided on the other surface of the substrate.
The near-infrared cut filter according to the present invention preferably has a near-infrared reflective film made of the dielectric multilayer film on both surfaces of the substrate. By having such characteristics, the near-infrared cut filter according to the present invention reduces warping and cracking of the dielectric multilayer film.

<Film formation method>
In order to have the above-mentioned near-infrared reflective film or the specific function film on the transparent substrate, for example, the above-mentioned near-infrared ray is directly formed on the transparent substrate by the above-mentioned CVD method, sputtering method, or vacuum deposition method. It can be obtained by forming a reflective film or a specific function film, or by sticking a near-infrared reflective film or a specific function film obtained by the above-mentioned method on a transparent substrate with an adhesive.
When the specific functional film is obtained from a liquid composition containing a raw material, it can be obtained by, for example, directly applying the liquid composition on a transparent substrate and drying it.
When the specific function film is provided on one surface of the transparent substrate, the specific function film may be one kind, or a plurality of kinds of specific function films may be laminated. When a plurality of types of specific function films are stacked, for example, a plurality of types of specific function films can be stacked by the film forming method described above.
Thus, by producing the near-infrared cut filter according to the present invention, it is possible to obtain a near-infrared cut filter with less warping and cracking of the dielectric multilayer film.

〔Protective film〕
The near-infrared cut filter according to the present invention has a structure in which a protective film is further laminated on a laminate obtained by laminating a cyclic olefin resin substrate, a near-infrared reflective film, and, if necessary, the specific function film. The protective film is used to prevent scratches and contamination of the surface when processing a near-infrared cut filter or incorporating it into a solid-state imaging device, etc. It will be peeled off later.
These protective films need to have a peel strength from the surface of the laminate and a peel strength of 240 N after storage for 240 hours under conditions of a temperature of 85 ° C. and a humidity of 85%, and preferably Is preferably 0.3 to 0.01N. By using a protective film having such a peeling force, the near-infrared cut filter surface does not warp after the protective film is peeled off, and the adhesive of the protective film does not remain, and even if incorporated in a solid-state imaging device, the warp and optical characteristics of A near-infrared cut filter that does not deteriorate is obtained. In addition, the measurement of the said peeling force was made into the test piece width of 10 mm of a near-infrared cut filter and a protective film laminated body according to JISK6854-1, and a double-sided adhesive material was used for the near-infrared cut filter as a rigid adherend. It is the result of having measured the peeling speed of the protective film in the fixed state at 50 mm / min.
The structure of the protective film is not particularly limited as long as it satisfies the above conditions, but a protective film having an adhesive layer on the thermoplastic resin film is used. Examples of the thermoplastic resin include PET and PE-based ones. A resin or the like is used, and an adhesive layer made of EVA, PE, acrylic, or silicon resin is used.
A protective film is normally laminated | stacked through the adhesion layer on the surface of the said laminated body.

[Use of near-infrared cut filter]
These near-infrared cut filters obtained by the present invention have excellent near-infrared cut ability and are difficult to break. Therefore, it is useful not only as a heat ray cut filter mounted on glass of automobiles and buildings, but also particularly useful for correcting the visibility of solid-state image sensors such as CCDs and CMOSs in digital still cameras and mobile phone cameras. It is.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited at all by this Example. “Parts” and “%” mean “parts by weight” and “% by weight” unless otherwise specified.

First, a method for measuring each physical property value and a method for evaluating the physical property are described.
(1) Glass transition temperature (Tg):
Using a differential scanning calorimeter (DSC6200) manufactured by Seiko Instruments Inc., the temperature was increased at a rate of 10 ° C. per minute under a nitrogen stream.
(2) Peeling force of protective film:
In accordance with JIS K 6854-1, using an Instron universal material testing machine (model 5567), the test piece width of the near infrared cut filter and the protective film laminate is 10 mm, and the near infrared cut filter side is rigidly attached. The protective film was measured at an angle of 90 degrees with respect to the rigid adherend and at a peeling rate of 50 mm / min in a state of being fixed to the material via a double-sided adhesive material.
(3) Spectral transmittance:
Measurement was performed using a spectrophotometer (U-3410) manufactured by Hitachi, Ltd.

Example 1
Dielectric multilayer film reflecting near-infrared rays at a deposition temperature of 150 ° C. on both sides of a substrate made of norbornene-based transparent resin “Arton G” manufactured by JSR Corporation and having a thickness of 100 μm and two sides of 110 mm × 260 mm. (Silica (SiO2: film thickness: 120 to 190 nm) layers and titania (TiO2: film thickness: 70 to 120 nm) layers are alternately stacked, the number of layers is 25 on one side, a total of 50) is formed by vapor deposition. A filter was manufactured. A protective film “PAC-3-50THK” manufactured by Sanei Kaken Co., Ltd. was bonded to the optical filter using a laminator. When the peel strength of the protective film at this time was examined, it was 0.02N. Then, it applied to wet heat conditions 85 degreeC x 85% RH for 240 hours in the state which bonded the protective film. After the test, when the peel strength of the protective film was examined, it was 0.15 N, which was a level that could be easily peeled by hand. Moreover, when the surface of the near-infrared cut filter from which the protective film was peeled was observed, no warpage was observed, and when observed using an optical microscope, no adhesive residue derived from the adhesive material of the protective film was observed. Further, the spectral transmittance in the visible light region (wavelength 400 to 700 nm) was 90% or more, and no deterioration in optical characteristics was observed.

Example 2
A protective film “6221FC-60” manufactured by Sekisui Chemical Co., Ltd. was bonded to the optical filter produced in the same manner as in Example 1. When the peeling force of the protective film at this time was investigated, it was 0.03N. Then, it applied to the wet heat test 85 degreeC x 85% RH for 240 hours in the state which bonded the protective film. After the test, when the peel strength of the protective film was examined, it was 0.31 N, which was a level that could be easily peeled by hand. Moreover, when the surface of the near-infrared cut filter from which the protective film was peeled was observed, no warpage was observed, and when observed using an optical microscope, no adhesive residue derived from the adhesive material of the protective film was observed. Further, the spectral transmittance in the visible light region (wavelength 400 to 700 nm) was 90% or more, and no deterioration in optical characteristics was observed.

Comparative Example 1
A protective film “PAC-3-60T” manufactured by Sanei Kaken Co., Ltd. was bonded to the optical filter produced in the same manner as in Example 1. The peel strength of the protective film at this time was examined and found to be 0.15N. Then, it applied to the wet heat test 85 degreeC x 85% RH for 240 hours in the state which bonded the protective film. After the test, when the peel strength of the protective film was examined, it was 2.5 N or more, which was difficult to peel by hand. Moreover, when the surface of the near-infrared cut filter which peeled off the protective film was observed, damage was recognized in part, and when observed using the optical microscope, the adhesive residue derived from the adhesive material of the protective film was not observed. Further, the spectral transmittance in the visible light region (wavelength 400 to 700 nm) was 90% or more, and no deterioration in optical characteristics was observed.

Comparative Example 2
A protective film “MPF451K” manufactured by Mitsui Chemicals was bonded to the optical filter produced in the same manner as in Example 1. When the peel strength of the protective film at this time was examined, it was 0.89 N, which was a level at which peeling by hand was difficult, and damage was observed on the surface of the near infrared cut filter. Then, it applied to the wet heat test 85 degreeC x 85% RH for 240 hours in the state which bonded the protective film. After the test, the peel strength of the protective film was examined and found to be 0.40N. Moreover, when the surface of the near-infrared cut filter which peeled off the protective film was observed, there was no damage and the adhesive residue derived from the adhesive material of a protective film was not observed. Further, the spectral transmittance in the visible light region (wavelength 400 to 700 nm) was 90% or more, and no deterioration in optical characteristics was observed.

Claims (3)

It has a structure in which a protective film is further laminated on a cyclic olefin-based resin substrate and a laminate having a near-infrared reflective film on both surfaces of the resin substrate, the peeling force from the laminate surface of the protective film, and a temperature of 85 ° C. And the peeling force after storage for 24 hours under the condition of 85% humidity is 0. A near-infrared cut filter characterized by being 5 N or less. The laminate has a structure in which a near-infrared reflective film is laminated on both sides of a cyclic olefin-based resin substrate,
The near-infrared cut filter according to claim 1, wherein the near-infrared cut filter has a structure in which a protective film is further laminated on both surfaces of the laminate. By laminating a near-infrared reflective film to form a laminate on both sides of the cyclic olefin-based resin substrate and the resin substrate, on both surfaces of the laminate, the peel strength of a laminate surface, temperature of 8 5 ° C. and humidity 8 5 % Of the peel force after storage for 24 hours under the condition of 0.1%. 5. A method for producing a near-infrared cut filter, further comprising laminating a protective film of N or less.