JP2016014690A - Optical filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical filter to be bonded to an adherend to reduce transmission of blue light and to suppress a yellow hue of reflected light and transmitted light.SOLUTION: The optical filter includes a transparent substrate and an adhesive layer provided on the transparent substrate. The adhesive layer comprises an adhesive, a tone correction dye, and a UV absorbent. When the UV absorbent is dispersed by 41.7 parts by mass as a single component in 100 parts by mass of an adhesive 100 for transmittance measurement and is prepared into a sample for transmittance measurement having a thickness of 25 μm, the sample exhibits 95% or less of transmittance at a wavelength of 420 nm and an average transmittance of 95% in a wavelength range from 450 to 780 under the condition that influences of light absorption by the adhesive for transmittance measurement are eliminated. The optical filter has a blue light cut rate of 15% or more and XYZ color system chromaticity coordinates specified by JIS-Z8701 satisfying x≤0.321 and y≤0.334.

Description

  The present invention relates to an optical filter, and more particularly to an optical filter that is bonded to an adherend and used to reduce blue light.

  Blue light having a wavelength of 380 to 495 nm has the highest energy among visible light, so that it easily reaches the retina in the back of the eye, and there is a concern about influences on the eyes such as a circadian clock error and a decrease in visual acuity. In particular, in recent years, LED displays have been used in place of conventional CRT televisions, but the intensity of blue light emitted from LED displays is greater than that of CRT televisions. Since LED displays are used in various electronic devices such as television receivers, mobile phones, smart phones, electronic book terminals, and portable game machines, it is required to reduce the intensity of emitted blue light.

  For example, as an ophthalmic instrument such as eyeglasses that suppresses the transmission of blue light or violet light to suppress a reduction in visual acuity, one having a violet light vertical cut-off filter is known. This violet light vertical cut-off filter rapidly absorbs light having a wavelength in the range of about 400 to 450 nm, and a violet light absorbing dye is covalently bonded to the polymer, or the violet light absorbing dye is free in the polymer. Is distributed. According to the ophthalmic device having such a violet light vertical cut-off filter, it is possible to suppress a decrease in visual acuity by suppressing the transmission of blue light or violet light (see, for example, Patent Document 1).

JP 2007-535708 A

  However, an absorption optical filter using a violet light absorbing dye or the like as described above does not necessarily have good optical characteristics and appearance because transmitted light and reflected light are yellowish. In addition, a reflection type optical filter that reduces transmission of blue light or the like by reflecting blue light or the like without using a violet light absorbing dye or the like is also known. However, the reflection type optical filter does not necessarily have a good appearance because the reflected light has a blue color, and the image quality is degraded by the reflected light having a blue color when used on a front surface of a display or the like. There is a risk.

  The present invention has been made in order to solve the above-described problems, and is bonded to an adherend to reduce the transmission of blue light, and the yellowness of reflected light and transmitted light is suppressed. An object is to provide an optical filter.

  The optical filter of the embodiment includes a transparent base material and an adhesive layer provided on the transparent base material. The pressure-sensitive adhesive layer has a pressure-sensitive adhesive, a color tone correction dye, and an ultraviolet absorber. The UV absorber was measured for a transmittance measuring sample having a thickness of 25 μm, in which 41.7 parts by weight of the UV absorber was singly dispersed in 100 parts by weight of the transmittance measuring adhesive, and the transmittance measuring adhesive was used. The transmittance at a wavelength of 420 nm excluding the influence of light absorption is 95% or less, and the average transmittance at a wavelength of 450 to 780 nm is 95% or more. In the optical filter of the embodiment, the blue light cut rate is 15% or more, and the XYZ color system chromaticity coordinates of JIS-Z8701 of transmitted light are x ≦ 0.321 and y ≦ 0.334.

  According to the present invention, it is possible to provide an optical filter that can be attached to an adherend to reduce the transmission of blue light, and that can suppress the yellowness of reflected light and transmitted light and has a good appearance.

Sectional drawing which shows one Embodiment of an optical filter.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a cross-sectional view showing an embodiment of the optical filter 10.

  The optical filter 10 includes a transparent substrate 11 and an adhesive layer 12 provided on the transparent substrate 11. The pressure-sensitive adhesive layer 12 has a pressure-sensitive adhesive, a color tone correction dye, and an ultraviolet absorber.

  The UV absorber was measured for a transmittance measuring sample having a thickness of 25 μm, in which 41.7 parts by weight of the UV absorber was singly dispersed in 100 parts by weight of the transmittance measuring adhesive, and the transmittance measuring adhesive was used. The transmittance at a wavelength of 420 nm excluding the influence of light absorption is 95% or less, and the average transmittance at a wavelength of 450 to 780 nm is 95% or more. Further, the optical filter 10 has a blue light cut rate of 15% or more, and XYZ color system chromaticity coordinates of transmitted light JIS-Z8701 are x ≦ 0.321 and y ≦ 0.334. Note that the pressure-sensitive adhesive for measuring transmittance is not necessarily the same as the pressure-sensitive adhesive used for the optical filter 10 and may be different.

  The optical filter 10 of the embodiment uses a combination of a color tone correction dye and an ultraviolet absorber as described above, and has a transmittance of 95% or less at a wavelength of 420 nm measured under a predetermined condition as the ultraviolet absorber. The average transmittance at 450 to 780 nm is 95% or more. Thereby, the chromaticity coordinates of the transmitted light can be set to x ≦ 0.321 and y ≦ 0.334 while the blue light cut rate is set to 15% or more. In other words, while suppressing the transmission of blue light and reducing the effects on the eyes such as the circadian clock's deviation and decreased visual acuity, the appearance is reduced by suppressing the yellowness of reflected light and transmitted light and making it achromatic. Can be good.

  When the transmittance of the ultraviolet absorber at a wavelength of 420 nm exceeds 95%, there is a possibility that the transmission of blue light cannot be effectively reduced. In such a case, it is possible to reduce the transmission of blue light by dispersing a large amount of the ultraviolet absorber, but there is a possibility that the yellowness of the reflected light and transmitted light may become strong, and a color tone correction dye is used in combination. However, there is a possibility that the yellowishness of the reflected light and transmitted light can be suppressed and an achromatic color cannot be obtained. Further, when the average transmittance at a wavelength of 450 to 780 nm of the ultraviolet absorber is less than 95%, the transmittance of visible light is lowered, so that the optical characteristics as the optical filter 10 may not be good.

  The transmittance of the ultraviolet absorber at a wavelength of 420 nm is preferably 94% or less, more preferably 93% or less, from the viewpoint of reducing the transmission of blue light. The lower limit of the transmittance is not necessarily limited, but is preferably 85% or more, more preferably 88% or more, and further preferably 90% or more. On the other hand, the average transmittance at a wavelength of 450 to 780 nm of the ultraviolet absorber is preferably 96% or more, more preferably 97% or more, and further preferably 98% or more from the viewpoint of improving the optical characteristics of the optical filter 10.

In addition, when the blue light cut rate of the optical filter 10 is less than 15%, the transmission of blue light cannot be sufficiently reduced, and there is a possibility that the influence on the eyes, such as a deviation of the biological clock or a decrease in visual acuity, cannot be reduced. Here, the blue light cut rate is calculated by the following formula using the blue light hazard function of JIS T7333 (Appendix B).
Blue light cut rate = 100− (X / Y) × 100 [%]
X = value obtained by multiplying the transmittance at each wavelength of 380 to 500 nm by the blue light hazard function at each wavelength. Y = the value obtained by summing the blue light hazard function at each wavelength.

  Furthermore, when the chromaticity coordinates of the transmitted light of the optical filter 10 are x> 0.321 and y> 0.334, the yellowness of the transmitted light may become strong. Moreover, when the yellowness of transmitted light becomes strong, generally the yellowness of reflected light also becomes strong, so that the appearance may not be good.

  The optical filter 10 is used by being bonded to the front surface of the image display unit of the image display device, for example, and is required to obtain a good image. Therefore, the transmitted light and the reflected light are preferably achromatic. . For this reason, the chromaticity coordinates of the transmitted light of the optical filter 10 are preferably 0.270 ≦ x ≦ 0.321 and 0.290 ≦ y ≦ 0.334, and 0.275 ≦ x ≦ 0.321 and 0.295. ≦ y ≦ 0.334 is more preferable.

  Further, the luminous average transmittance Tv of the optical filter 10 is preferably 80% or more, more preferably 82% or more, and further preferably 84% or more.

  The transparent substrate 11 is not particularly limited as long as it has transparency, but a resin film is preferably used. Examples of resin films include polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyolefins such as polyethylene and polypropylene, polyacrylates such as polymethyl methacrylate, polycarbonate, polystyrene, triacetate, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, and ethylene-acetic acid. Examples thereof include vinyl copolymers, polyvinyl butyral, polyurethane, cellophane and the like. The transparent substrate 11 may be provided with a functional layer such as an antireflection layer as necessary. 10-200 micrometers is preferable and, as for the thickness of the transparent base material 11, 50-150 micrometers is more preferable.

  Examples of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 12 include an acrylic pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a butadiene-based pressure-sensitive adhesive, and a urethane-based pressure-sensitive adhesive.

  The acrylic pressure-sensitive adhesive is a polymer containing an acrylic monomer unit as a main component. Examples of the acrylic monomer include (meth) acrylic acid, itaconic acid, (anhydrous) maleic acid, (anhydrous) fumaric acid, crotonic acid, and alkyl esters thereof. Here, “(meth) acrylic acid” means acrylic acid and methacrylic acid.

  Among the acrylic monomers, those having (meth) acrylic acid or an alkyl ester thereof as a main component are preferable. Here, the main component means that (meth) acrylic acid or an alkyl ester thereof is contained in an amount of 95% by mass or more based on the total amount of the acrylic pressure-sensitive adhesive. More preferably, it is 98 mass% or more, More preferably, it is 99 mass% or more.

  Examples of alkyl esters of (meth) acrylic acid include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, n-pentyl (meth) acrylate, and n-hexyl (meta ) Acrylate, n-heptyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, and the like. .

  In order to increase the cohesive strength of the pressure-sensitive adhesive, it is preferable to use a monomer having a functional group (for example, a hydroxy group, a glycidyl group, etc.) that can become a crosslinking point. Examples of the monomer having a functional group that can serve as a crosslinking point include hydroxyethyl (meth) acrylate, glycidyl (meth) acrylate, and the like.

  When using a monomer having such a crosslinking point, it is preferable to add a crosslinking agent. The cohesive force can be ensured by reacting a crosslinking agent with a crosslinking point to crosslink the polymer. Examples of cross-linking agents include melamine resins, urea resins, epoxy resins, metal oxides, metal salts, metal hydroxides, metal chelates, polyisocyanates, carboxy group-containing polymers, acid anhydrides, polyamines, and so on. It is suitably selected according to the type of functional group that can be obtained.

  The glass transition temperature (Tg) of the acrylic pressure-sensitive adhesive is preferably -40 to 40 ° C, and more preferably -30 to 10 ° C.

  The color correction pigment dispersed in the adhesive layer 12 absorbs light in a specific wavelength range of visible light, and is used in combination with an ultraviolet absorber to reduce the transmission of blue light while reflecting light. In addition, the yellow color of transmitted light is suppressed to make it achromatic.

  The color tone correction dye is not particularly limited as long as it absorbs light in a specific wavelength range of visible light. For example, azo, condensed azo, diimonium, phthalocyanine, anthraquinone, indigo, perinone, Perylene-based, dioxazine-based, quinacridone-based, methine-based, isoindolinone-based, quinophthalone-based, pyrrole-based, thioindigo-based, porphyrin-based, tetraazaporphyrin-based organic pigments or organic dyes, or inorganic pigments can be used. These color tone correction dyes may be used alone or in combination of two or more. Anthraquinone series, quinophthalone series, and tetraazaporphyrin series are preferred because of good light resistance, compatibility with adhesives, and dispersibility.

"Anthraquinone dye"
The anthraquinone dye preferably has a structure represented by the following general formulas (1) and (2).

In the formula, R ^{1 to} R ⁸ are each independently a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom, a cyano group, a benzyl group, a hydroxyl group, an alkyl group having 1 to 12 carbon atoms, or one or more hydrogen atoms are fluorine atoms. C1-C12 alkyl group substituted by an atom, bromine atom, or chlorine atom, phenyl group, phenyl group, one or more hydrogen atoms substituted by fluorine atom, bromine atom, or chlorine atom, carbon number An alkoxyl group having 1 to 12 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms in which one or more hydrogen atoms are substituted with a fluorine atom, a bromine atom, or a chlorine atom, —CO—R ^a (where R ^a is the number of carbon atoms) 1-8 alkyl group, a phenyl group, a benzyl group, a cyclohexyl group, cyclohexylmethyl group, or a 1-naphthyl group or a 2-naphthyl ^{group,), -. S-R} b ( Here, R Is an alkyl group having 1 to 8 carbon atoms, a phenyl group, a benzyl group, a cyclohexyl group, cyclohexylmethyl group, or a 1-naphthyl group or a 2-naphthyl group.), Or -NH-Ph (where Ph is either a phenyl group or a phenyl group in which one or more hydrogen atoms are substituted with either an alkyl group having 1 to 10 carbon atoms or an alkoxyl group having 1 to 10 carbon atoms.

Among the compounds represented by formula (1), R ⁸ is preferably —NH—Ph (where Ph has the same meaning as described above). R ¹ , R ⁴ , and R ⁵ are preferably such that one of these groups is —NH—Ph (where Ph has the same meaning as described above), and the other two groups are hydrogen atoms. . R ² , R ³ , R ⁶ and R ⁷ are preferably hydrogen atoms. According to the said substituent, since the solubility to a solvent is favorable, it is preferable.

In the formula, R ^{9 to} R ²² are each independently a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom, a cyano group, a benzyl group, an alkyl group having 1 to 12 carbon atoms, or one or more hydrogen atoms are fluorine atoms, A bromine atom or an alkyl group having 1 to 12 carbon atoms substituted by a chlorine atom, a phenyl group, a phenyl group having one or more hydrogen atoms substituted by a fluorine atom, a bromine atom, or a chlorine atom; 12 alkoxyl groups, an alkoxyl group in which one or more hydrogen atoms are substituted by fluorine atoms, bromine atoms, or chlorine atoms, —CO—R ^c (where R ^c is an alkyl group having 1 to 8 carbon atoms, phenyl group, , benzyl group, cyclohexyl group, cyclohexylmethyl group, or a 1-naphthyl group or a 2-naphthyl ^{group,), -. S-R} d ( where, ^{R d} is from 1 to 8 carbon atoms alkyl Group, phenyl group, benzyl group, cyclohexyl group, cyclohexylmethyl group, 1-naphthyl group, or 2-naphthyl group), or -NH-Ph (where Ph is the same as above). Either.

  As the anthraquinone dye, the compound represented by the formula (1) is preferably used from the viewpoint of solubility in a solvent. Examples of the anthraquinone dye represented by the formula (1) include, for example, Kayaset Violet A-R (manufactured by Nippon Kayaku Co., Ltd., trade name, maximum absorption wavelength λmax: 554 nm, half width: 119 nm, the following formula (3)), Kayaset Green AB (Nippon Kayaku Co., Ltd., trade name, maximum absorption wavelength λmax: 642 nm, half width: 123 nm, following formula (4)), Kayaset Blue B20 (Nippon Kayaku Co., Ltd., trade name, maximum absorption wavelength) Preferred examples include λmax: 631 nm, half-value width: 99 nm, and the following formula (5).

"Tetraazaporphyrin dyes"
The tetraazaporphyrin-based dye preferably has a structure represented by the formula (6).

In the formula, each of R ^{23 to} R ³⁰ is independently a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom, a cyano group, a benzyl group, or one or more hydrogen atoms are substituted with a fluorine atom, a bromine atom, or a chlorine atom. Benzyl group, phenyl group, phenyl group in which one or more hydrogen atoms are substituted by fluorine atom, bromine atom, or chlorine atom, alkyl group having 1 to 10 carbon atoms, one or more hydrogen atoms in fluorine atom, bromine C1-10 alkyl group substituted by an atom or a chlorine atom, C1-10 alkoxyl group, or carbon number by which one or more hydrogen atoms are substituted by a fluorine atom, a bromine atom or a chlorine atom 1 to 10 alkoxyl groups. M ¹ is any ^one of Cu, Ni, Zn, Pd, Pt, VO, Co, or Mg. R ^{23 to} R ³⁰ are preferably an alkyl group having 1 to 6 carbon atoms from the viewpoint of solubility in a solvent. M ¹ is preferably Cu or VO.

  Preferred examples of the tetraazaporphyrin-based dye represented by the formula (6) include trade names “TAP-2”, “TAP-18”, and “TAP-45” manufactured by Yamada Chemical Co., Ltd.

  As the color correction dye, those having a maximum absorption wavelength λmax of 380 to 780 nm are preferably used. Among these, those having a maximum absorption wavelength λmax of 400 nm or more and less than 500 nm, particularly 430 nm or more and 480 nm or less are preferable because only one type can provide a sufficient effect.

  In addition, when the above-described maximum absorption wavelength λmax is not used, that is, when the maximum absorption wavelength λmax is only 500 nm or more and 780 nm or less, the maximum absorption wavelength λmax is 500 nm or more and less than 590 nm. In particular, a sufficient effect can be obtained by using a combination of the first color correction dye having a wavelength of 530 nm to 580 nm and a second color correction dye having a maximum absorption wavelength λmax of 590 nm to 780 nm, particularly 600 nm to 650 nm. It is preferable because it is obtained. When the first color correction dye and the second color correction dye are used in combination, from the viewpoint of obtaining a sufficient effect, the first color correction dye: the second color correction dye = 1: 7 to mass ratio. 7: 1 is preferred.

  The content of the color correction dye is preferably 0.0015 parts by mass or more in total with respect to 100 parts by mass of the pressure-sensitive adhesive. When the content is 0.0015 parts by mass or more, when used in combination with an ultraviolet absorber, the yellowness of reflected light and transmitted light is suppressed effectively while suppressing the transmission of blue light. Can be colored. The content is preferably 0.002 parts by mass or more, and more preferably 0.003 parts by mass or more. The upper limit of the content is not necessarily limited, but if the content is excessively large, the reflected light and the transmitted light tend to be blue or green, so from the viewpoint of making the achromatic color not blue or green 0.08 parts by mass The following is preferable, and 0.06 parts by mass or less is more preferable.

  The ultraviolet absorber dispersed in the adhesive layer 12 mainly suppresses the transmission of blue light, and is used in combination with a color tone correction pigment to suppress the transmission of blue light while reflecting and transmitting light. It can be made achromatic by suppressing the yellowness of the. As described above, the ultraviolet absorber was measured on a transmittance measuring sample having a thickness of 25 μm, in which 41.7 parts by mass of the ultraviolet absorber were separately dispersed in 100 parts by mass of the adhesive for measuring transmittance, and the transmittance. The average transmittance at a wavelength of 450 to 780 nm excluding the influence of light absorption by the pressure-sensitive adhesive for measurement is 95% or more. The ultraviolet absorber preferably has a maximum absorption wavelength λmax of 330 to 390 nm, more preferably 340 to 380 nm.

  The ultraviolet absorber is not particularly limited as long as the transmittance at a wavelength of 420 nm and the average transmittance at a wavelength of 450 to 780 nm are within a predetermined range when measured under predetermined conditions as described above. Benzotriazole UV absorber, benzophenone UV absorber, salicylate UV absorber, cyanoacrylate UV absorber, triazine UV absorber, oxanilide UV absorber, nickel complex UV absorber, inorganic UV absorber Etc. can be used. These ultraviolet absorbers may be used alone or in combination of two or more. When two or more kinds of ultraviolet absorbers are used in combination, when the two or more kinds of ultraviolet absorbers are dispersed in an adhesive and measured, the transmittance at the wavelength of 420 nm and the wavelength of 450 to 780 nm are described. As long as the average transmittance is satisfied.

"Triazine UV absorber"
As the ultraviolet absorber, for example, a triazine-based ultraviolet absorber represented by the formula (7) is preferable. The triazine-based ultraviolet absorber represented by the formula (7) is preferable because it is particularly excellent in durability.

In the formula, R ³¹ is a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom, a hydroxyl group, a cyano group, a benzyl group, an alkyl group having 1 to 12 carbon atoms, or one or more hydrogen atoms are a fluorine atom, a bromine atom, or chlorine. An alkyl group having 1 to 12 carbon atoms substituted with an atom, a phenyl group, a phenyl group in which one or more hydrogen atoms are substituted with a fluorine atom, a bromine atom, or a chlorine atom, an alkoxyl group having 1 to 12 carbon atoms, one or more Wherein the hydrogen atom is substituted with a fluorine atom, a bromine atom, or a chlorine atom, -CO-R ^a (wherein R ^a is an alkyl group having 1 to 8 carbon atoms, a phenyl group, benzyl group, a cyclohexyl group, cyclohexylmethyl group, or a 1-naphthyl group or a 2-naphthyl ^{group), -. O-CH (} R b) -CO-O-R c ( where ^{R b} is the number of carbon atoms 12 alkyl group, ^{R c} is an alkyl group having 1 to 20 carbon atoms), - ^{S-R d} (where, ^{R d} represents an alkyl group having 1 to 8 carbon atoms, a phenyl group, a benzyl group, a cyclohexyl group, cyclohexyl Any one of a methyl group, a 1-naphthyl group, and a 2-naphthyl group), or -NH-Ph (where Ph has the same meaning as described above).

R ^{32 to} R ⁴² are each independently a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom, a hydroxyl group, a cyano group, a benzyl group, an alkyl group having 1 to 12 carbon atoms, or one or more hydrogen atoms are a fluorine atom, bromine An alkyl group having 1 to 12 carbon atoms substituted by an atom or a chlorine atom, a phenyl group, a phenyl group having one or more hydrogen atoms substituted by a fluorine atom, a bromine atom, or a chlorine atom; An alkoxyl group in which one or more hydrogen atoms are substituted with a fluorine atom, a bromine atom, or a chlorine atom, —CO—R ^e (where R ^e is an alkyl group having 1 to 8 carbon atoms, a phenyl group, , A benzyl group, a cyclohexyl group, a cyclohexylmethyl group, a 1-naphthyl group, or a 2-naphthyl group.), —O—CH (R ^f ) —CO—O—R ^g (however, R ^f is an alkyl group having 1 to 12 carbon atoms, R ^g is an alkyl group having 1 to 20 carbon atoms, -S-R ^h (where R ^h is an alkyl group having 1 to 8 carbon atoms, phenyl Any one of a group, a benzyl group, a cyclohexyl group, a cyclohexylmethyl group, a 1-naphthyl group, and a 2-naphthyl group), or —NH—Ph (where Ph has the same meaning as described above). is there.

  a and b are each independently an integer of 0 to 3.

R ³¹ is preferably an alkyl group having 4 to 10 carbon atoms, an alkyl group having 4 to 10 carbon atoms in which one or more hydrogen atoms are substituted with a fluorine atom or a chlorine atom, an alkoxyl group having 4 to 10 carbon atoms, A C4-C10 alkoxyl group in which one or more hydrogen atoms are substituted with a fluorine atom or a chlorine atom, -CO- ^Ra '(wherein ^Ra ' is an alkyl group having 1 to 4 carbon atoms). , —O—CH (R ^b ′) —CO—O—R ^c ′ (where R ^b ′ is an alkyl group having 1 to 10 carbon atoms, and R ^c ′ is an alkyl group having 1 to 18 carbon atoms). It is preferable in terms of solubility in an organic solvent.

In particular, R ³¹ is preferably —O—CH (R ^b ′) —CO—O—R ^c ′, R ^b ′ has preferably 1 to 6 carbon atoms, and R ^c ′ has 6 to 18 carbon atoms. More preferred. It is preferable for R ^{31 to} be the above group since the solubility of the triazine compound in an organic solvent is improved. In addition, by the number of carbon atoms of R ^c is in the above range is preferable because the solubility and the like in an organic solvent is further improved.

R ^{32 to} R ⁴² are each independently a hydrogen atom, a chlorine atom, a fluorine atom, a hydroxyl group, a cyano group, an alkyl group having 1 to 4 carbon atoms, or one or more hydrogen atoms are substituted with a fluorine atom or a chlorine atom. An alkyl group having 1 to 4 carbon atoms, an alkoxyl group having 1 to 12 carbon atoms, an alkoxyl group in which one or more hydrogen atoms are substituted with a fluorine atom or a chlorine atom, -CO-R ^e '(provided that R ^e 'Is an alkyl group having 1 to 4 carbon atoms.), —O—CH (R ^f ′) —CO—O—R ^g ′ (where R ^f ′ is an alkyl group having 1 to 10 carbon atoms, R ^g 'Is preferably an alkyl group having 1 to 18 carbon atoms) from the viewpoint of solubility in an organic solvent.

  The triazine-based ultraviolet absorber is more preferably a triazine-based ultraviolet absorber represented by the formula (8).

In the formula, R ⁴³ and R ⁴⁴ are each independently a hydrogen atom, or —CH (CH ₃ ) —CO ₂ —C ₈ H ₁₇ (iso), R ⁴⁵ and R ⁴⁶ are both —CH (CH ₃ ). it is a _{-CO 2 -C 8 H 17 (iso} ).

  A commercially available product can be used as the triazine-based ultraviolet absorber represented by the formula (8). For example, TINUVIN477 (manufactured by Ciba, trade name, maximum absorption wavelength λmax: 357 nm, transmittance at a wavelength of 420 nm, 91. 9% and an average transmittance of 99.7% at a wavelength of 450 to 780 nm) can be preferably used.

"Benzophenone UV absorber"
As the ultraviolet absorber, for example, benzophenone-based ultraviolet absorbers represented by the following formulas (9) and (10) are also preferably used.

  The total content of the ultraviolet absorber is preferably 10 parts by mass or more with respect to 100 parts by mass of the adhesive. By setting the content to 10 parts by mass or more, it is possible to effectively suppress transmission of blue light while suppressing yellowness in reflected light and transmitted light. As for content, 13 mass parts or more are more preferable, and 16 mass parts or more are still more preferable. The upper limit of the content is not necessarily limited. However, when the content is increased, the yellowishness of the reflected light and transmitted light of the optical filter 10 becomes strong, and formation of the adhesive layer 12 is likely to be difficult. 50 parts by mass or less is more preferable, and 33 parts by mass or less is more preferable.

  The pressure-sensitive adhesive layer 12 is basically composed of a pressure-sensitive adhesive, a color tone correction dye, and an ultraviolet absorber, but may contain other components as necessary and within the limits not departing from the gist of the present invention. As other components, a near infrared absorbing dye, a leveling agent, an antistatic agent, a heat stabilizer, an antioxidant, a dispersant, a flame retardant, a lubricant, a plasticizer, and the like may be contained.

  Examples of near infrared absorbing dyes include polymethine dyes, phthalocyanine dyes, naphthalocyanine dyes, aminium dyes, imonium dyes, diimonium dyes, anthraquinone dyes, naphthoquinone dyes, indolephenol dyes, azo dyes Examples thereof include dyes, triallylmethane dyes, and tungsten oxide dyes.

  When the other component is contained in the adhesive layer 12, the other component is preferably 10% by mass or less, and more preferably 5% by mass or less with respect to the entire adhesive layer 12.

  The thickness of the adhesive layer 12 is preferably 0.3 μm or more. By setting the thickness to 0.3 μm or more, it can be effectively bonded to the adherend, and transmission of blue light can be effectively suppressed. In light of adhesiveness to the adherend and suppression of blue light transmission, the thickness is more preferably 0.5 μm or more, and even more preferably 1 μm or more. The upper limit of the thickness is not necessarily limited, but is preferably 100 μm or less, more preferably 50 μm or less, from the viewpoint of suppressing the remaining organic solvent during formation.

  Such an optical filter 10 is used, for example, by being bonded to the front surface of the image display unit of the image display device with its own adhesive layer 12. A typical example of the image display device is an LED display that generates a relatively large intensity of blue light, but is not necessarily limited thereto. Examples of LED displays include those used in television receivers, mobile phones, smartphones, electronic book terminals, portable game machines, and the like, but are not limited to these and are used in various electronic devices. Things. Further, the optical filter 10 is not necessarily limited to the image display device, and can be used indefinitely for those requiring blue light reduction.

  The pressure-sensitive adhesive layer 12 is usually prepared by dissolving a pressure-sensitive adhesive, a color correction dye, an ultraviolet absorber, and other components added as necessary in an organic solvent to prepare a pressure-sensitive adhesive composition. 11 is applied and dried.

  Organic solvents include aromatics such as toluene and xylene, amides such as N-methyl-2-pyrrolidone, dimethylformamide, and dimethylacetamide, ketones such as methyl ethyl ketone, methyl isobutyl ketone, and acetone, methanol, ethanol, i- Examples thereof include alcohols such as propyl alcohol, hydrocarbons such as hexane, and tetrahydrofuran. These organic solvents may be used alone or in combination of two or more.

  Examples of coating methods (coating methods) include dip coating, spray coating, spinner coating, bead coating, wire bar coating, blade coating, roller coating, curtain coating, and slit die coater. Coating methods such as a gravure coater method, a slit reverse coater method, a micro gravure method, and a comma coater method can be employed.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the above-described embodiments, and various modifications and substitutions are made to the above-described embodiments without departing from the scope of the present invention. be able to.

Hereinafter, more specific description will be given with reference to examples.
Examples 1-4 are examples of the present invention, and examples 5-8 are comparative examples of the present invention.

(Example 1)
16 parts by mass of methyl ethyl ketone, triazine-based ultraviolet absorber (Ciba, trade name “TINUVIN477”, maximum absorption wavelength λmax: 357 nm, transmittance at a wavelength of 420 nm: 91.9%, average transmittance at a wavelength of 450 to 780 nm : 99.7%) After adding 6 parts by mass, 0.0013 parts by mass of a quinophthalone compound (manufactured by Yamamoto Kasei Co., Ltd., MS Yellow HD-137, maximum absorption wavelength λmax: 445 nm, half-value width: 55 nm) as a color tone correction dye The mixture was stirred for 10 minutes with a mixer to prepare a mixed solution.

  80 parts by mass of an adhesive solution containing an acrylic adhesive and a solvent (trade name: NCK101, acid value: 0 mgKOH / g, Tg: -20 ° C., solid content: 30% by mass) And 0.93 part by mass of a crosslinking agent (trade name: Coronate HL, manufactured by Nippon Polyurethane Co., Ltd.), and then stirred for 10 minutes with a mixer to prepare an adhesive composition.

  On the separator in which the silicone layer was formed on the PET film, the pressure-sensitive adhesive composition was applied using an applicator and dried in an oven at 100 ° C. for 5 minutes to form a pressure-sensitive adhesive layer. Thereafter, the separator on which the adhesive layer is formed is laminated on an antireflection film (trade name “RL1700”, manufactured by NOF Corporation) as a transparent substrate, and an optical filter having an adhesive layer formed on the transparent substrate is obtained. Produced. In addition, the thickness of the adhesion layer was 25 micrometers.

(Example 2)
An optical filter in the same manner as in Example 1 except that 0.0031 parts by mass of an azo-cobalt complex (manufactured by Yamamoto Kasei Co., Ltd., ORASOL YELLOW 2RLN, maximum absorption wavelength λmax: 466 nm, half-value width: 57 nm) was used as a color correction dye. Was made.

(Example 3)
An anthraquinone dye (manufactured by Nippon Kayaku Co., Ltd., trade name: Kayaset Violet AR, maximum absorption wavelength λmax: 554 nm, half-value width: 119 nm, formula (3)) Example 1 except that 0.0050 parts by mass of a dye (manufactured by Nippon Kayaku Co., Ltd., trade name: Kayaset GREEN AB, maximum absorption wavelength λmax: 642 nm, half width: 123 nm, formula (4)) was used Thus, an optical filter was produced.

(Example 4)
Anthraquinone dye (manufactured by Nippon Kayaku Co., Ltd., trade name: Kayaset Violet AR, maximum absorption wavelength λmax: 554 nm, half-value width: 119 nm, formula (3)) 0.0108 parts by mass and anthraquinone Optics in the same manner as in Example 1 except that 0.0027 parts by mass of a dye (manufactured by Nippon Kayaku Co., Ltd., trade name: Kayaset Blue B20, maximum absorption wavelength λmax: 631 nm, half width: 99 nm, formula (5)) is used. A filter was produced.

(Example 5)
As a UV absorber, triazine UV absorber (Ciba, trade name “TINUVIN 384-2”, maximum absorption wavelength λmax: 345 nm, transmittance at a wavelength of 420 nm: 98.7%, average transmittance at a wavelength of 450 to 780 nm (Rate: 99.2%) 6 parts by mass, and 0.0044 parts by mass of a quinophthalone compound (manufactured by Yamamoto Kasei Co., Ltd., MS Yellow HD-137, maximum absorption wavelength λmax: 445 nm, half-value width: 55 nm) were used as the color correction dye. An optical filter was produced in the same manner as in Example 1 except for the above.

(Example 6)
As a UV absorber, triazine UV absorber (Ciba, trade name “TINUVIN 384-2”, maximum absorption wavelength λmax: 345 nm, transmittance at a wavelength of 420 nm: 98.7%, average transmittance at a wavelength of 450 to 780 nm (Rate: 99.2%) 6 parts by mass, 0.0111 parts by mass of an azo-cobalt complex (manufactured by Yamamoto Kasei Co., Ltd., ORASOL YELLOW 2RLN, maximum absorption wavelength λmax: 466 nm, half-value width: 57 nm) is used as a color correction dye. An optical filter was produced in the same manner as in Example 1 except that.

(Example 7)
As a UV absorber, a triazine UV absorber (trade name “TINUVIN479” manufactured by Ciba, Inc., maximum absorption wavelength λmax: 323 nm, transmittance at a wavelength of 420 nm: 95.7%, average transmittance at a wavelength of 450 to 780 nm: 99.3%) 6 parts by mass, a quinophthalone compound (manufactured by Yamamoto Kasei Co., Ltd., MS Yellow HD-137, maximum absorption wavelength λmax: 445 nm, half-value width: 55 nm) as a color tone correction dye, 0.0025 parts by mass and an azo-cobalt complex (Yamamoto Kasei Co., Ltd., ORASOL YELLOW 2RLN, maximum absorption wavelength λmax: 466 nm, half-value width: 57 nm) An optical filter was produced in the same manner as in Example 1 except that 0.0009 parts by mass were used.

(Example 8)
As an optical filter, a commercially available reflective blue light cut film (manufactured by Elecom, trade name: EF-FL102WBL) was used.

  In addition, the transmittance | permeability in wavelength 420nm and the average transmittance | permeability in wavelength 450-780nm of an ultraviolet absorber were measured as follows. First, an adhesive solution containing an acrylic adhesive (adhesive for measuring transmittance) and a solvent (manufactured by Toyo Ink Co., Ltd., trade name: NCK101, acid value: 0 mgKOH / g, Tg: -20 ° C., solid content: 30 mass) %) Was added with an ultraviolet absorber to prepare a transmittance measuring composition. The addition amount of the ultraviolet absorber in the transmittance measurement composition was 12.5 parts by mass of the ultraviolet absorber with respect to 100 parts by mass of the acrylic adhesive (that is, the solid content of the acrylic adhesive solution). Then, the composition for transmittance | permeability measurement was apply | coated so that the thickness after drying might be set to 25 micrometers on the transparent base material (Toyobo Co., Ltd. make, brand name: A4100), and the sample for transmittance | permeability measurement was produced. A 20 × 20 mm square test piece was cut out from this transmittance measurement sample, and the spectrum was measured using a C light source with a spectrophotometer (manufactured by Shimadzu Corporation, SolidSpec-3700), and then an acrylic adhesive and a transparent substrate The transmittance at a wavelength of 420 nm and the average transmittance at a wavelength of 450 to 780 nm were determined by excluding the effect of light absorption due to.

Next, the following characteristics of the optical filters of Examples 1 to 8 were evaluated.
In Table 1, an evaluation result is shown with a composition of an adhesive composition.

(optical properties)
A 20 × 20 mm square test piece was cut out from the optical filter (excluding the separator) in Examples 1 to 8, and a spectrophotometer (SolidSpec-3700, manufactured by Shimadzu Corporation) was used in the range of 380 to 1000 nm using a C light source. The spectrum was measured, and luminosity average transmittance Tv, XYZ color system chromaticity coordinates (x, y) of transmitted light and reflected light were calculated according to JIS Z8701-1999.

Moreover, the blue light cut rate was computed by the following formula using the blue light hazard function of JIST7333 (Annex B).
Blue light cut rate = 100− (X / Y) × 100 [%]
X = value obtained by multiplying the transmittance at each wavelength of 380 to 500 nm by the blue light hazard function at each wavelength. Y = the value obtained by summing the blue light hazard function at each wavelength.

  Furthermore, the optical characteristics were determined based on the chromaticity coordinates of the transmitted light and the reflected light obtained by the above measurement. In the judgment, the reflected light and the transmitted light are achromatic (0.270 ≦ x ≦ 0.321, 0.290 ≦ y ≦ 0.334), and the yellowness of the reflected light and the transmitted light is determined. A strong one or a blue or green strong one was designated as “x”.

(Heat-resistant)
For the optical filters of Examples 1 to 8 (excluding the separator), the temperature was set to 80 ° C. using a constant temperature and temperature chamber (trade name: DS-44, manufactured by Yamato Co., Ltd.), and the test was conducted for 96 hours. It was. After the test, the spectrum was measured to determine the luminous average transmittance Tv, the transmitted light and the chromaticity coordinates (x, y), and compared with the measured values before the test. “◯” indicates that the amount of change before and after the test is less than 5%, “△” indicates that any change is 5% or more and less than 10%, and “Δ” indicates that any change is 10% or more. × ”.

(Light resistance)
The optical filters of Examples 1 to 8 (excluding the separator) were irradiated with light of 380 nm or more at 100 MJ / cm ² using a light resistance tester (manufactured by Suga Test Instruments Co., Ltd., trade name: Xenon Weather Meter X25). . After irradiation, the spectrum was measured to determine the luminous average transmittance Tv and the chromaticity coordinates (x, y) of transmitted light and reflected light, and compared with the measured values before the test. “◯” indicates that the amount of change before and after the test is less than 5%, “△” indicates that any change is 5% or more and less than 10%, and “Δ” indicates that any change is 10% or more. × ”.

  As in the optical filters of Examples 1 to 4, a combination of a color tone correction dye and an ultraviolet absorber is used, and an ultraviolet absorber having a predetermined transmittance is effective in transmitting blue light. In addition, it is possible to reduce the yellowness of reflected light and transmitted light to make an achromatic color. On the other hand, those having a high transmittance as an ultraviolet absorber, such as the optical filters of Examples 5 to 7, are sufficient in the yellowness of reflected light and transmitted light even if the proportion of the color tone correction dye is increased. Can not be reduced. Further, in the case of a reflective optical filter like the optical filter of Example 8, it is recognized that blue light of reflected light becomes strong because blue light is reflected.

  DESCRIPTION OF SYMBOLS 10 ... Optical filter, 11 ... Transparent base material, 12 ... Adhesive layer

Claims (5)

An optical filter having a transparent substrate and an adhesive layer provided on the transparent substrate,
The adhesive layer has an adhesive, a color correction dye, and an ultraviolet absorber,
The UV absorber was measured for a transmittance measuring sample having a thickness of 25 μm, in which 41.7 parts by mass of the UV absorber were dispersed alone in 100 parts by mass of the adhesive for measuring transmittance, and for measuring the transmittance. The transmittance at a wavelength of 420 nm excluding the effect of light absorption by the adhesive is 95% or less and the average transmittance at a wavelength of 450 to 780 nm is 95% or more,
The optical filter is characterized in that the blue light cut rate is 15% or more, and the XYZ color system chromaticity coordinates of JIS-Z8701 of transmitted light are x ≦ 0.321 and y ≦ 0.334. .   The optical filter according to claim 1, wherein the chromaticity coordinates are 0.270 ≦ x ≦ 0.321 and 0.290 ≦ y ≦ 0.334.   The optical filter according to claim 1, wherein the adhesive layer contains 0.0015 parts by mass or more of the color tone correction dye and 10 parts by mass or more of the ultraviolet absorber with respect to 100 parts by mass of the adhesive.   The optical filter according to claim 1, wherein the ultraviolet absorber includes a triazine ultraviolet absorber.   The optical filter according to any one of claims 1 to 4, wherein the color tone correction dye contains at least one selected from a quinophthalone dye, an azo-cobalt complex, and an anthraquinone dye.

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