JP2016071104A - Optical member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical member having excellent weather resistance and a suppressed initial yellowness.SOLUTION: The optical member includes at least an optical layer and an adhesive layer: the adhesive layer comprises an acrylic polymer having a crosslinked structure by a urethane bond, and a benzotriazole compound; and the optical layer comprises a polymer having an alkoxy group-containing bisphenol A (meth)acrylate compound as a structural unit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical member having excellent weather resistance.

  In recent years, as environmental problems such as global warming become more serious, the development of optical members that can adjust the absorption, deflection, reflection, transmission, etc. of external light has been developed for the purpose of energy saving and reduction of carbon dioxide emissions. It is being advanced.

  For example, by providing an optical member on a window glass of a house, automobile, etc., light incident on the room from a light source such as the sun through the window glass is deflected to the ceiling side, and the deflected light is used as indirect lighting in the room can do. Thus, by improving the room illuminance using the daylighting function of the optical member, reduction of power consumption and reduction of carbon dioxide emission are expected.

  The optical member usually has an optical layer and an adhesive layer for bonding the optical layer to a window glass or the like. Such an optical layer is required to be formed using a material that has high moldability and is less likely to be deformed over time because the above-described function is exhibited depending on its shape. In addition, in order to improve indoor illuminance and room temperature using outside light, it is necessary to take in a larger amount of light into the room, and the optical layer is also required to have high light transmittance. It is done. Therefore, ionizing radiation curable resin is suitable as the material for the optical layer.

  However, since the phenyl group existing in the structure of the ionizing radiation curable resin and the unreacted polymerizable unsaturated bond easily absorb ultraviolet rays of external light, the optical layer is liable to undergo photodegradation. Had. On the other hand, if a weathering agent such as an ultraviolet absorber or a light stabilizer is included in order to prevent the optical layer from deteriorating, the ultraviolet light required to cure the resin during the molding of the optical layer is absorbed by the weathering agent and cured. There was a problem that the reaction was hindered, making it difficult to mold the optical layer into a desired shape.

  Therefore, in an optical member such as a window film to be bonded to the inside of a window glass or the like with respect to the incident direction of external light, a weathering agent is included in the adhesive layer, and deterioration of the optical layer such as ultraviolet rays contained in external light is caused. By absorbing the wavelength light which is a factor in the adhesive layer, the optical layer is prevented from being deteriorated and the weather resistance of the optical member is improved.

  For example, Patent Document 1 discloses a (meth) acrylic acid ester copolymer having a carboxyl group, a metal chelate crosslinking agent, and a triazine as an adhesive for window films having high holding power, weather resistance, and ultraviolet absorption ability. An adhesive containing a UV absorber is disclosed. Moreover, the window film provided with the contact bonding layer containing the above-mentioned composition and the light control layer formed with ionizing radiation-curable resin is disclosed.

Japanese Patent No. 4881208

  However, when the present inventors examined, even if it is a case where the contact bonding layer containing the composition disclosed by patent document 1 is used, the ionizing radiation curable resin used for an optical layer is alkoxy group containing bisphenol A type ( When the meth) acrylate compound is included in the constituent unit, the problem of preventing the deterioration of the optical layer by the adhesive layer cannot be obtained, and the weather resistance of the optical member cannot be sufficiently improved. Further, in Patent Document 1, a metal chelate crosslinking agent is used for forming an adhesive layer, but depending on the material used together, the metal chelate crosslinking agent may yield a yellowish cured product. There is also a problem that it is not suitable for use in an optical member.

  This invention is made | formed in view of the said situation, and it aims at providing the optical member which was excellent in a weather resistance and the initial stage yellowness was suppressed.

  As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have a wavelength selectivity of an ultraviolet absorber contained in an adhesive layer having an alkoxy group-containing bisphenol A type (meth) acrylate compound as a constituent unit. The present inventors have found that it contributes to suppression of deterioration of an optical layer containing a polymer, and completed the present invention.

That is, the present invention is an optical member having at least an optical layer and an adhesive layer, wherein the adhesive layer contains an acrylic polymer having a crosslinked structure by a urethane bond, and a benzotriazole compound. The layer includes a polymer having an alkoxy group-containing bisphenol A type (meth) acrylate compound as a structural unit.
In the present invention, “(meth) acrylate” means “acrylate or methacrylate”.

According to the present invention, since the adhesive layer includes the above-described composition, the above-mentioned alkoxy group-containing bisphenol A type (meta) which is a structural unit of the polymer contained in the optical layer out of the external light incident on the optical member. Since the wavelength light that causes the deterioration of the acrylate compound is selectively and sufficiently absorbed in the benzotriazole-based compound in the adhesive layer, deterioration of the optical layer can be suppressed. Thereby, it can be set as an optical member with high weather resistance.
In addition, the acrylic polymer having a crosslinked structure by the urethane bond can be obtained, for example, by crosslinking an acrylic copolymer and an isocyanate crosslinking agent, and it is not necessary to use a metal chelate crosslinking agent. Yellowness can be suppressed.

  In the above invention, the benzotriazole-based compound is bonded to a molecule constituting the acrylic polymer having a crosslinked structure by the urethane bond even if the benzotriazole-based compound is present in the adhesive layer in the form of being added as an additive. And may be present in the adhesive layer. The benzotriazole-based compound can selectively and sufficiently absorb the wavelength light that causes the deterioration of the alkoxy group-containing bisphenol A type (meth) acrylate compound in any of the above forms, and the optical layer This is because it is possible to suppress deterioration of the film.

  In the said invention, it is preferable that the said optical layer increases a light collection amount using reflected light. This is because the optical member for increasing the amount of collected light is exposed to light for a long time and requires high weather resistance, so that the effect of the adhesive layer can be fully exhibited.

  In this invention, there exists an effect that it can be set as the optical member which was excellent in weather resistance and the initial stage yellowness was suppressed.

It is a schematic sectional drawing which shows an example of the optical member of this invention. It is the schematic perspective view and schematic sectional drawing which show an example of the optical layer in this invention. It is explanatory drawing for demonstrating the light transmission path | route in the louver type optical layer whose light control part in this invention is a low refractive index part. It is explanatory drawing which shows the example of the longitudinal cross-sectional shape of the light control part in this invention. It is a schematic sectional drawing which shows the other example of the optical member of this invention.

  Hereinafter, the optical member of the present invention will be described in detail.

  The optical member of the present invention is an optical member having at least an optical layer and an adhesive layer, wherein the adhesive layer contains an acrylic polymer having a crosslinked structure by a urethane bond, and a benzotriazole-based compound, The optical layer includes a polymer having an alkoxy group-containing bisphenol A type (meth) acrylate compound as a constituent unit.

  The optical member of the present invention will be described with reference to the drawings. FIG. 1 is a schematic sectional view showing an example of the optical member of the present invention. The optical member 10 of the present invention has at least the adhesive layer 1 and the optical layer 2. The adhesive layer 1 contains an acrylic polymer having a crosslinked structure by urethane bonds and a benzotriazole-based compound, and the optical layer 2 is a polymer having an alkoxy group-containing bisphenol A type (meth) acrylate compound as a constituent unit. Is included. In FIG. 1, the adhesive layer 1 in the optical member 10 is disposed on the light source side (upper side in FIG. 1) of the external light L with respect to the optical layer 2.

  Such an optical member can exhibit various light control functions depending on the structure of the optical layer. For example, the direction and amount of light emitted from the optical layer can be controlled by selectively absorbing, polarizing, reflecting, and transmitting light incident on the optical layer. In addition, the light controlled in this invention shall include not only visible light but the light of the wavelength from the infrared light contained in sunlight to ultraviolet light. That is, the amount of heat rays emitted from the optical layer can be adjusted by controlling the infrared light incident on the optical layer, and the amount of light collected can be adjusted by controlling the incident visible light. .

  In the present invention, the polymer in the optical layer has an alkoxy group-containing bisphenol A type (meth) acrylate compound as a structural unit. The polymer is a terminal of the alkoxy group-containing bisphenol A type (meth) acrylate monomer. It means having a state of cross-linking polymerization at the group. The polymer may have only one of the alkoxy group-containing bisphenol A type (meth) acrylate compounds as a structural unit, or may have two or more types as a structural unit.

The inventors of the present invention have made extensive studies on the combination of an optical layer containing a polymer having an alkoxy group-containing bisphenol A-type (meth) acrylate compound as a structural unit and an adhesive layer, and found that ultraviolet rays contained in the adhesive layer. Among the absorbents, when using a triazine compound, a cyanoacrylate compound, or the like, deterioration of the optical layer is difficult to suppress, whereas when using a benzotriazole compound, deterioration of the optical layer is sufficiently suppressed. I knew that.
The difference in effect due to the ultraviolet absorber is presumed to be due to the following reason. That is, the wavelength band that can be specifically absorbed varies depending on the type of the ultraviolet absorber, but the absorption wavelength band of the benzotriazole compound is phenyl in the molecular structure of the alkoxy group-containing bisphenol A type (meth) acrylate compound. It is considered that the group overlaps in a wide range with the wavelength band of light that is easily absorbed. For this reason, it is estimated that the benzotriazole-based compound can selectively and sufficiently absorb the wavelength light that causes the deterioration of the alkoxy group-containing bisphenol A type (meth) acrylate compound as compared with other compounds.

  As described above, in the present invention, since the adhesive layer contains a benzotriazole-based compound, among the external light incident on the optical member, the alkoxy group-containing bisphenol A type which is a constituent unit of the polymer forming the optical layer ( Since the wavelength light that causes deterioration of the (meth) acrylate compound is sufficiently absorbed in the adhesive layer, deterioration of the optical layer is suppressed, so that an optical member having high weather resistance can be obtained.

  However, when the benzotriazole compound and the metal chelate crosslinking agent are used together, there is a problem that a yellowish cured product can be obtained. In the present invention, instead of the metal chelate crosslinking agent, for example, by using an isocyanate crosslinking agent to obtain an acrylic polymer having a crosslinked structure due to a urethane bond, the above problems are solved and the initial yellowness of the adhesive layer is suppressed. Can do. That is, according to the present invention, since the adhesive layer includes the above-described composition, it is possible to obtain an optical member having excellent weather resistance and suppressing initial yellowness.

  Hereinafter, the details of the optical member of the present invention will be described.

1. Adhesive layer The adhesive layer in the present invention contains an acrylic polymer having a crosslinked structure by urethane bonds and a benzotriazole-based compound. Each will be described below.

(1) Acrylic polymer having a crosslinked structure by urethane bonds The acrylic polymer having a crosslinked structure by urethane bonds contained in the adhesive layer may be any material that can obtain an acrylic polymer having a desired structure. The production method is not particularly limited. Such an acrylic polymer can be obtained, for example, by crosslinking an acrylic copolymer and an isocyanate crosslinking agent. Each will be described below.

(A) Acrylic copolymer The acrylic copolymer is an adhesive main agent, and is preferably one that is crosslinked by heating in the crosslinking reaction with an isocyanate crosslinking agent described later. This is because in the case of crosslinking by light irradiation, the weather resistance of the adhesive layer after curing may be affected.
Examples of the acrylic copolymer include an acrylic ester copolymer obtained by copolymerizing a (meth) acrylic ester as a main component and a (meth) acrylic monomer.
In addition, (meth) acrylic acid ester means acrylic acid ester or methacrylic acid ester. The same applies to the (meth) acrylic monomer in the following description.

  As a (meth) acrylic acid ester, a general thing can be used, it may be used individually by 1 type, and may be used in combination of 2 or more type. In the present invention, for example, butyl acrylate, isobutyl acrylate, t-butyl acrylate, butyl methacrylate, isobutyl methacrylate, and t-butyl methacrylate are preferably used.

Examples of the (meth) acrylic monomer include monofunctional (meth) acrylate, bifunctional to tetrafunctional polyfunctional (meth) acrylate, and the like. About these (meth) acrylic monomers, what has a functional group which becomes a crosslinking point with an isocyanate crosslinking agent copolymerized with an acrylate ester is preferable.
Examples of the functional group serving as a crosslinking point include a hydroxyl group, a carboxyl group, an amide group, an amino group, an epoxy group, and a cyano group. In the (meth) acrylic monomer, one of these functional groups is included in the molecular structure. It is preferable to have 1 type to 4 types as a whole.

  Among them, as the (meth) acrylic monomer constituting the acrylic copolymer, butyl acrylate, isobutyl acrylate, t-butyl acrylate, butyl methacrylate, isobutyl methacrylate, and t-butyl methacrylate are preferably used. .

The acrylic copolymer is not particularly limited with respect to the copolymerization form, and may be any of a random copolymer, a block copolymer, and a graft copolymer. Preferably there is.
In addition, the weight average molecular weight (Mw) of the acrylic copolymer is not particularly limited as long as the adhesive layer in the present invention can exhibit a desired adhesive force, but it is in the range of 200000 to 1400000, and in particular, 600000 to 1000000. It is preferable to be within the range, particularly within the range of 750000 to 850000. If the weight average molecular weight is smaller than the above range, the adhesive force may decrease with a decrease in cohesive force. On the other hand, when the weight average molecular weight is larger than the above range, the optical member of the present invention can be firmly bonded to the window glass or the like, but the adhesive force is too high and it is difficult to peel off from the window glass or the like at the time of replacement. There is.
In addition, the said weight average molecular weight is a value of polystyrene conversion at the time of measuring by gel permeation chromatography (GPC), and three LF-804 made by Showa Denko KK is used for the measurement, and THF is used as a developing solvent. Shall be used.

  Further, the content ratio of the acrylate ester and the (meth) acryl monomer in the acrylic copolymer is not particularly limited as long as the acrylate ester is a main component, and the adhesive layer in the present invention has a desired adhesive force and weather resistance. It can set suitably so that a property and an optical characteristic may be shown.

(B) Isocyanate crosslinking agent The isocyanate crosslinking agent is not particularly limited, and conventionally known crosslinking agents can be widely used. For example, an aliphatic isocyanate crosslinking agent or an aromatic isocyanate crosslinking agent can be preferably used. Examples of the aliphatic isocyanate crosslinking agent include 1,6-hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2-methyl-1,5-pentane diisocyanate, 3-methyl-1,5-pentane diisocyanate, and lysine. Examples include diisocyanate, isophorone diisocyanate, cyclohexyl diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, and hydrogenated tetramethylxylene diisocyanate. Among them, 1,6-hexamethylene diisocyanate is preferably used. It is done. Examples of the aromatic isocyanate crosslinking agent include tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, and isophorone diisocyanate. Among these, tolylene diisocyanate and xylene diisocyanate are preferably used. The above-mentioned isocyanate crosslinking agents may be used alone or in combination of two or more.

  Examples of commercially available isocyanate crosslinking agents include D-94, Y-75, TD-75, L-45E manufactured by Soken Chemical Co., Ltd., and coronate (L, T-80, T-65, manufactured by Nippon Polyurethane Industry Co., Ltd.). T-100), Takenate (500, 600) manufactured by Mitsui Chemicals, Duranate (P301-75E, D201, 24A-100) manufactured by Asahi Kasei Chemicals and the like can be used.

  As content of an isocyanate crosslinking agent, it exists in the range of 0.01 mass-40 mass parts with respect to 100 mass parts of acrylic copolymers, and especially in the range of 0.1 mass-20 mass parts, especially 0.5 mass. It is preferable that it exists in the range of -10 mass parts. If the content of the isocyanate cross-linking agent is more than the above range, the cross-linking reaction with the acrylic copolymer is excessively accelerated and the curing becomes too dense, so that the adhesive layer is likely to deteriorate, and as an optical member. On the other hand, if the amount is less than the above range, the crosslinking reaction is not sufficiently performed and the curing becomes too sparse, so that the curing is insufficient and the adhesive strength may be decreased.

(C) Acrylic polymer having a crosslinked structure by urethane bond The acrylic polymer having a crosslinked structure by urethane bond can be obtained, for example, by crosslinking an acrylic copolymer and an isocyanate crosslinking agent as described above. Furthermore, arbitrary monomers, oligomers, and other polymers may be included and these may be crosslinked. Examples of the optional monomer include a hydroxyl group-containing (meth) acrylic monomer such as 2-hydroxypropyl acrylate.

(2) Benzotriazole-based compound In the present invention, the form in which the benzotriazole-based compound is contained is not particularly limited as long as the benzotriazole-based compound is contained in the adhesive layer. For example, the benzotriazole-based compound is added as an additive, that is, is not bonded to the molecule constituting the acrylic polymer having a crosslinked structure by the urethane bond, and is in an independent form in the adhesive layer. It may exist (first form). Moreover, the said benzotriazole type compound may exist in the contact bonding layer in the form couple | bonded with the molecule | numerator which comprises the acrylic polymer which has the crosslinked structure by the said urethane bond (2nd form). The benzotriazole-based compound selectively and sufficiently absorbs the wavelength light that causes the deterioration of the alkoxy group-containing bisphenol A type (meth) acrylate compound even if it exists in the adhesive layer in any of the above forms. And deterioration of the optical layer can be suppressed. Hereinafter, each form is demonstrated.

(A) 1st form In this form, the benzotriazole type compound exists in the said contact bonding layer with the form added as an additive. Although it does not specifically limit as a benzotriazole type compound in this form, For example, 2'-hydroxyphenyl-5-chlorobenzotriazole type compounds, 2'-hydroxyphenyl benzotriazole type compounds, 2- (2H -Benzotriazol-2-yl) -6- (1-methyl-1-phenylethyl) -4- (1,1,3,3-tetramethylbutyl) phenol, 2- (2H-benzotriazol-2-yl ) -4,6-bis (1-methyl-1-phenylethyl) phenol, benzenepropanoic acid and 3- (2H-benzotriazol-2-yl) -5- (1,1-dimethylethyl) -4-hydroxy An acryloyl group or methacryloyl on the benzotriazole skeleton, such as an ester compound with (C7-C9 side chain and straight chain alkyl) And reactive compounds into which a group has been introduced. These may be used alone or in combination.

  Among them, in the present invention, 2- (2′-hydroxy5′-methylphenyl) benzotriazole, 2- (2H-benzotriazol-2-yl) -6- (1-methyl-1-phenylethyl) -4 -(1,1,3,3-tetramethylbutyl) phenol, 2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) phenol, benzenepropanoic acid and Ester compounds with 3- (2H-benzotriazol-2-yl) -5- (1,1-dimethylethyl) -4-hydroxy (C7-C9 side chain and linear alkyl) are preferred.

  Examples of commercially available benzotriazole compounds include Biosorb 520 (manufactured by Kyodo Yakuhin Co., Ltd.), Tinuvin 171, 384-2, 328, 99-2, PS, 928, 900, 1130 (above, manufactured by BASF) JF-77, 80, 83, 832, JAST-500 (above, manufactured by Johoku Chemical Co., Ltd.), Sumisorb 200, 250, 300, 340 (above, manufactured by Sumitomo Chemical Co., Ltd.), KEMISORB 71, 73, 79, 279 (above, manufactured by Chemipro Kasei Co., Ltd.), Further, Seesorb 704, 706 (manufactured by Sipro Kasei Co., Ltd.) can be used.

  In this embodiment, the content of the benzotriazole-based compound in the adhesive layer is within the range of 0.1 to 25 parts by mass, particularly 1 to 25 parts by mass with respect to 100 parts by mass of the acrylic copolymer. It is preferable to be within the range, particularly within the range of 3 parts by mass to 20 parts by mass. If the content of the benzotriazole-based compound is larger than the above range, there may be a problem in the appearance of the entire optical member due to coloring of the adhesive layer. May not be sufficiently absorbed, and the optical layer may deteriorate.

(B) 2nd form In this form, the benzotriazole type compound exists in the contact bonding layer with the form couple | bonded with the molecule | numerator which comprises the acrylic polymer which has the crosslinked structure by the said urethane bond. In this case, it is preferable that the benzotriazole-based compound has a reactive group that binds to the acrylic polymer having a crosslinked structure by the urethane bond. When the acrylic copolymer and the isocyanate cross-linking agent are polymerized, an acrylic polymer having a benzotriazole-based compound bonded to the molecule starting from the reactive group can be obtained. Although the benzotriazole type compound used in this form is not specifically limited, RUVA-93 (made by Otsuka Pharmaceutical Co., Ltd.) etc. can be used conveniently.

  Since the content of the benzotriazole-based compound in this embodiment is the same as that in the “(a) first embodiment” described above, the description in this section is omitted.

(3) Arbitrary material The adhesive layer in this invention may contain the light stabilizer etc. other than the above-mentioned composition from a viewpoint that a weather resistance further improves. The light stabilizer is preferably a hindered amine light stabilizer or the like, and may have a reactive group in the molecule.

  About content of the light stabilizer in a contact bonding layer, it should just exist in the range of 0 mass-7 mass parts with respect to 100 mass parts of acrylic copolymers, and is in the range of 0 mass parts-5 mass parts especially. It is particularly preferable that the content be in the range of 0 to 5 parts by mass.

  Moreover, the adhesive layer in the present invention may contain a silane coupling agent, an antioxidant, an adhesion-imparting agent, a crosslinking agent other than an isocyanate-based agent, a filler, a leveling agent, and the like as optional materials. Such an adhesion-imparting material is not particularly limited as long as it is generally used for an adhesive layer. For example, a rosin-based adhesion-imparting agent is suitable.

(4) Adhesive layer The gel fraction of the adhesive layer in the present invention is preferably within a range having an adhesive force capable of being bonded to glass or the like with a desired film thickness, and is 50% to 90% after curing. %, Particularly 60% to 85%, particularly 70% to 80%. When the gel fraction of the adhesive layer is larger than the above range, the crosslink density is increased to show a high adhesive force, and the optical member of the present invention can be firmly bonded to a window glass or the like, but the adhesive force is high. In some cases, it may be difficult to peel off the window glass when it is pasted. In addition, when the crosslink density is too high, the adhesive layer may be easily deteriorated. On the other hand, when the gel fraction of the adhesive layer is smaller than the above range, the desired adhesive force may not be exhibited because the crosslinking density is low.
The gel fraction is a value measured by the following method.
(Measurement method of gel fraction)
The adhesive layer sandwiched between the separators is cut out at 10 cm × 10 cm square. The weight of the adhesive layer that has been cut out is rounded and placed in a bottle, and the weight of the adhesive layer before processing is measured from the difference. Next, the adhesive layer was immersed in MEK in a jar and prevented from volatilizing and allowed to stand for 3 hours, and then placed on a 10 cm × 10 cm 100 mesh net whose weight was measured in advance, and eluted from the waste liquid and the adhesive layer. Discard the monomer. It is dried at 60 ° C. for 24 hours with the adhesive layer placed thereon, and the weight of the adhesive layer after the mesh net after drying and the solvent immersion / drying is measured. The weight was calculated and the gel fraction was determined from the following formula.
Gel fraction (%) = {(weight of adhesive layer after treatment (g)) / (weight of adhesive layer before treatment (g))} × 100

  The thickness of the adhesive layer is preferably in the range of 5 μm to 100 μm, and more preferably in the range of 10 μm to 75 μm. If the thickness of the adhesive layer is larger than the above range, it may lead to an increase in the thickness and weight of the entire optical member, while if smaller than the above range, the adhesive layer cannot sufficiently absorb ultraviolet rays, Degradation of the optical layer may occur.

The method for forming the adhesive layer is not particularly limited as long as it can be formed with a desired film thickness. For example, an acrylic polymer material having a crosslinked structure with urethane bonds and a coating solution in which a benzotriazole compound is dissolved in a desired solvent are used. A method of applying to one surface of the optical layer and heating to cure the coating film can be used. Among them, it is preferable to perform an aging treatment after curing in order to promote crosslinking.
Examples of the coating method for applying the coating solution include a knife coater, an applicator coater, a die coater, a comma coater, a gravure coater, and a roll coater. Moreover, as an aging process, it is preferable to perform the heat processing for about 3 to 7 days at 40 degreeC, for example.

2. Optical layer The optical layer in the present invention contains a polymer having an alkoxy group-containing bisphenol A type (meth) acrylate compound as a structural unit. The alkoxy group-containing bisphenol A type (meth) acrylate compound is not particularly limited. For example, each polyfunctional (meth) such as ethylene oxide-modified bisphenol A, propylene oxide-modified bisphenol A, propoxylated ethoxylated bisphenol A, and the like. An acrylate compound etc. can be mentioned. Examples of the polyfunctional (meth) acrylate compound include di (meth) acrylate compounds and tri (meth) acrylate compounds.

  Specific examples of such alkoxy group-containing bisphenol A type (meth) acrylate compounds include ethylene oxide modified bisphenol A di (meth) acrylate, ethylene oxide modified bisphenol A tri (meth) acrylate, and propylene oxide modified bisphenol A di (meth) acrylate. , Propylene oxide-modified bisphenol A tri (meth) acrylate, propoxylated ethoxylated bisphenol A di (meth) acrylate, propoxylated ethoxylated bisphenol A tri (meth) acrylate, and the like.

  The optical layer may contain an arbitrary additive in addition to the above-described materials. Examples of the additive include a light stabilizer, a release agent, a polymerization inhibitor, a crosslinking agent, an antioxidant, a plasticizer, an antifoaming agent, and a filler. From the viewpoint of production, the optical layer in the present invention preferably contains no ultraviolet absorber. Moreover, it is preferable not to contain a light stabilizer from the viewpoint of shape stability.

The optical layer in the present invention can exhibit various light control functions depending on the structure of the optical layer. The structure of such an optical layer is not particularly limited as long as it can exhibit a desired light control function, and examples thereof include louver type and prism type optical layers. Of these, a louver type optical layer is preferable. This is because, according to the incident angle of the external light, it is possible to secure the amount of light collected by reflecting the incident light and to selectively transmit and shield the heat rays.
Hereinafter, the louver type optical layer and other optical layers will be described separately.

(1) Louver-type optical layer The louver-type optical layer in the present invention has a light transmission part having a plurality of grooves on one surface and a light control part formed in the groove. In the louver type optical layer, the light transmission part includes a polymer having an alkoxy group-containing bisphenol A type (meth) acrylate compound as a constituent unit.

  Such a louver type optical layer will be described with reference to the drawings. FIG. 2A is a schematic perspective view showing an example of a louver type optical layer in the present invention, and FIG. 2B is a cross-sectional view taken along line xx of FIG. As shown in FIGS. 2A and 2B, the louver type optical layer 2A has a plurality of groove portions 13 formed linearly and in parallel in the light transmitting portion 11, and has a light control portion 12 in the groove portion 13. It is.

  In the present invention, since the effect is easily exerted by arranging the adhesive layer on the light source side of the external light with respect to the optical layer, the surface of the optical layer on which the light control unit is formed is the light incident surface. In this case, the adhesive layer is preferably disposed on the surface of the optical layer where the light control unit is formed (upper side in FIG. 2).

  In the louver type optical layer, a light control method can be selected according to the material of the light control unit. For example, the light control unit is a low refractive index unit made of a resin material having a lower refractive index than that of the light transmission unit, so that all of the light due to the difference in refractive index is generated at the interface between the light transmission unit and the light control unit. By causing reflection, it is possible to increase the amount of collected light using the reflected light. Moreover, by making the light control part a heat ray absorbing part made of a material containing heat ray absorbing particles, it is possible to selectively transmit and shield the heat ray.

  FIG. 3 illustrates a light transmission path in an optical member when an optical layer having a light control unit made of a resin material having a lower refractive index than the light transmission unit is used for the optical member of the present invention. It is explanatory drawing for. The reference numerals not described in FIG. 3 are the same as those described in FIG. For example, as shown in FIG. 3, the optical layer 2 </ b> A in the optical member 10 is attached to the window glass plate 100 via the adhesive layer 1. Sunlight L incident from the window glass 100 is reflected upward in the figure at the interface between the light transmission part 11 and the light control part 12 in the optical layer 2A.

By using such an optical member for a building or the like, light taken from the outside can be guided not to the floor of the building but to the ceiling. A sufficient illuminance can be secured.
Hereinafter, each configuration of the louver type optical layer will be described.

(A) Light transmission part A light transmission part contains the polymer which has the alkoxy group containing bisphenol A type (meth) acrylate compound mentioned above as a structural unit.

The film thickness of the light transmitting portion is appropriately selected according to the height of the groove portion, and is, for example, in the range of 10 μm to 300 μm, especially in the range of 25 μm to 250 μm, particularly in the range of 50 μm to 200 μm. Is preferred. If the film thickness of the light transmission part is larger than the above range, the incident light is absorbed in the light transmission part, the amount of light emitted to the indoor side is reduced, and the visibility of the optical member of the present invention may be reduced. On the other hand, if it is smaller than the above range, it may be difficult to form the groove in a desired shape.
In addition, the film thickness of the light transmission part is the film thickness of the louver type optical layer, and is a part indicated by T1 in FIG.

  The shape and the like of the groove part of the light transmission part are the same as the shape and the like of the light control part which will be described later, and the description in this section is omitted.

The refractive index of the light transmission part is appropriately selected according to the type of the light control part, and is, for example, in the range of 1.40 to 1.80, particularly in the range of 1.45 to 1.70, particularly 1. It is preferable to be within the range of 50 to 1.65.
The refractive index of the light transmission part is measured at a wavelength of 589 nm under the condition of a temperature of 23 ° C. using an Abbe refractometer (manufactured by Atago Co., Ltd.) according to the refractive index measurement method defined in JIS K7142. Measured using a sodium light source. In the following description, the refractive index measurement method is measured by this method.

Further, the visible light transmittance of the light transmitting portion is preferably 70% or more, more preferably 80% or more, and particularly preferably 90% or more. When the light transmission part has the visible light transmittance described above, a decrease in the amount of light emitted to the indoor side due to absorption of incident light in the light transmission part is suppressed, and the visibility of the optical member of the present invention can be improved. .
The visible light transmittance was measured using a spectrophotometer (“UV-2450” manufactured by Shimadzu Corporation, JIS K 0115 compliant product), PET film manufactured by Toyobo (product number: Cosmo Shine A4300, film thickness: 100 μm). ) It is confirmed by measuring within a measurement wavelength range of 380 nm to 780 nm with respect to the light transmission part having a film thickness of 10 μm formed thereon.

(B) Light control part A light control part is formed in the groove part of a light transmission part. That is, the light control part and the groove part usually have the same shape. Further, the light control unit can select the function according to the constituent material.
Hereinafter, an example of an assumed light control unit will be described.

(I) Low refractive index portion The low refractive index portion is made of a resin material that exhibits a lower refractive index than the light transmitting portion. By making the light control part a low refractive index part, total reflection of light due to the difference in refractive index can be caused at the interface between the light transmission part and the light control part, and the amount of collected light using the reflected light can be increased. Can be planned.

The material of the low refractive index portion may be a transparent resin having a refractive index lower than that of the light transmitting portion, and is preferably an ionizing radiation curable resin. Examples of the ionizing radiation curable resin include an ultraviolet curable resin, an electron beam curable resin, a visible light curable resin, a near infrared curable resin, and the like. Among them, an ultraviolet curable resin and an electron beam curable resin are included. preferable.
As said ultraviolet curable resin and electron beam curable resin, it can select from the polymerizable oligomer thru | or prepolymer conventionally used conventionally, and can be used suitably. For example, polymerizable oligomers or prepolymers, especially polyfunctional polymerizable oligomers or prepolymers can be mentioned. These may be used alone or in combination of two or more.

  Moreover, when using an ultraviolet curable resin, it is preferable to use a photoinitiator together. As the type of the photopolymerization initiator, those conventionally used can be used. As a content rate of a photoinitiator, it is preferable that it is about 0.1-5 mass parts with respect to 100 mass parts of ultraviolet curable resin.

  Moreover, although the said low refractive index part may contain other arbitrary materials, it is preferable not to contain an ultraviolet absorber and a light stabilizer from a viewpoint of shape stability.

  The refractive index of the low refractive index portion may be lower than the refractive index of the light transmitting portion, and is preferably in the range of 1.40 to 1.55, for example.

  The low refractive index portion preferably has a desired visible light transmittance. Specifically, since it is the same as the visible light transmittance of the light transmitting portion described above, description thereof is omitted here.

(Ii) Heat ray absorbing portion The heat ray absorbing portion is made of a material containing heat ray absorbing particles as a heat ray absorbent. By making the light control unit a heat ray absorbing unit, it is possible to selectively transmit and shield heat rays. The composition of the heat ray absorbing part is not particularly limited as long as it can exhibit a desired function. The heat ray absorbing portion may include any material such as heat ray absorbing particles that transmit visible light and absorb heat rays, a binder resin such as an ionizing radiation curable resin, and a photoinitiator. In addition, it is preferable that the said heat ray absorption part does not contain about an ultraviolet absorber and a light stabilizer from a viewpoint of shape stability.

(Iii) Light Control Unit The light control unit has a vertical cross-sectional shape of a straight line or a curve having two or more hypotenuses on at least one of two side surfaces constituting a triangle, square, rectangle, trapezoid, and vertical cross-sectional shape. The taper shape comprised, the shape whose four sides are curves, etc. are mentioned. Further, the corner of the light control unit may have a curved surface according to the shape of the groove, and the side of the side surface forming the vertical cross-sectional shape may be a straight line or a curved line. FIG. 4 is an explanatory diagram showing an example of the longitudinal cross-sectional shape of the light control unit in the present invention. FIG. 4 (a) is a trapezoidal shape, and FIG. FIG. 4C shows an example of the longitudinal cross-sectional shape of the light control unit formed of a triangular shape having a curvature at a corner.

  The shape of the light control unit in plan view is not particularly limited, and may be, for example, a linear shape or a shape such as a curve. Furthermore, the arrangement of the light control units in plan view may be arranged in parallel, arranged in parallel, or randomly arranged in the other direction. In particular, as shown in FIG. 2A, it is preferable that the light control unit 12 be linearly arranged in parallel in a plan view.

  The height of the light control unit is preferably in the range of 10 μm to 300 μm, more preferably in the range of 25 μm to 250 μm, and particularly preferably in the range of 50 μm to 200 μm. Further, the height of the light control unit is in the range of 30% to less than 100% of the film thickness of the light transmission unit, in particular in the range of 40% to 97.5%, particularly in the range of 50% to 95%. Is preferred. This is because the film thickness of the optical member may be relatively increased and the flexibility may be decreased. The height of the light control unit is a part indicated by T2 in FIG.

  The width of the light control unit can be appropriately set according to the type of the light control unit. For example, when the light control part is a low refractive index part or a heat ray absorption part, the widest part of its width is within the range of 5 μm to 50 μm, especially within the range of 7 μm to 45 μm, especially within the range of 10 μm to 40 μm. Preferably there is. When the width of the light control unit is larger than the above range, it may be difficult for the entire optical member to transmit visible light. On the other hand, when the width of the light control unit is smaller than the above range, the light control unit may not have a desired height. This is because the desired light reflecting function and heat ray absorbing function may not be achieved. The width of the light control unit refers to the widest portion in the longitudinal cross-sectional shape of the light control unit, and is a portion indicated by W in FIG.

  The length of the light control unit is appropriately selected according to the size of the desired optical member. The length of the light control unit refers to the length in the longitudinal direction in plan view.

  The pitch width of the light control unit can be appropriately set according to the type of the light control unit. For example, when the light control unit is a low refractive index unit or a heat ray absorption unit, the pitch width is preferably within a range of 15 μm to 200 μm, more preferably within a range of 20 μm to 150 μm, and particularly preferably within a range of 25 μm to 100 μm. When the pitch width is larger than the above range, it is difficult for outside light having a large incident angle to enter the light control unit, and the function by the light control unit may not be sufficiently performed. This is because it may be difficult to transmit visible light in the light transmitting portion. The pitch width of the light control unit refers to the distance between the centers of adjacent light control units, and is a portion indicated by P in FIG.

(C) Louver-type optical layer The surface of the louver-type optical layer including the light control unit may be flat or uneven, and can be appropriately selected according to the function of the optical layer. For example, in an optical member that requires high visibility, the louvered optical layer preferably has a flat surface. The average surface roughness (Ra) of the louver type optical layer is preferably in the range of 0.1 nm to 100 nm, more preferably in the range of 0.1 nm to 20 nm, and particularly preferably in the range of 0.1 nm to 10 nm.
In the case where the surface has irregularities, there is a bias in the diffusion of light on the incident surface or the exit surface between the region where the incident surface or exit surface of the external light is flat and the region where the surface is concave or convex. For this reason, the amount of emitted light is biased to induce a light diffraction phenomenon and an interference phenomenon, whereby a multiple image appears on the optical member, and visibility may be lowered.
The average surface roughness (Ra) is measured in a measurement environment of 23 ° C. in accordance with the provisions of JIS B0601 2001, and only the reference length is extracted from the roughness curve in the direction of the average line. When the X axis is taken in the direction of Y and the Y axis is taken in the direction of the vertical magnification, and the roughness curve is represented by y = f (x), the value is calculated by the following equation (1).

  Moreover, the surface including the light control part of the louver type optical layer may have a planarization layer, a scattering layer, or the like. This is because the occurrence of the light diffraction phenomenon and interference phenomenon can be suppressed, and the deterioration of the visibility of the optical member due to the appearance of multiple images can be prevented. Moreover, you may have a photocatalyst layer for the purpose of air quality control.

  When the louver type optical layer is used as the optical layer of the optical member of the present invention, even if an adhesive layer is provided on the optical layer surface on the light incident side of the optical layer, the adhesive layer is provided on the optical layer surface on the light emitting side. May be provided. That is, even if an adhesive layer is provided on the surface of the optical layer where the light control unit is formed (upper side in FIG. 2), the surface of the optical layer where the light control unit is not formed (lower side in FIG. 2) An adhesive layer may be provided on the side).

  The method for forming the louver type optical layer is not particularly limited as long as it is a method capable of forming a light transmitting portion having a plurality of groove portions of a desired shape on the surface and forming a light control portion in the groove portion. The method for forming the light transmissive part is not particularly limited. For example, after the composition for forming the light transmissive part including the material for the light transmissive part is applied on the substrate, the shaping plate having the convex part is formed. It can be formed by crosslinking and curing in the pressed state. The shaped plate used at this time has a plurality of convex portions on the surface, and the inverted shape and the size of the convex portions usually correspond to the shape and size of the groove portion.

  The method for applying the light transmissive portion forming composition is not particularly limited as long as it can be applied with a uniform film thickness. For example, spin coating, die coating, dip coating, bar coating, and the like. A coating method, a gravure printing method, a screen printing method, or the like can be used. Moreover, as a hardening method of the composition for light transmissive part formation, hardening by irradiation of ionizing radiation is preferable, and it is preferable to use an ultraviolet ray or an electron beam from the point practical. About hardening conditions etc., it can set suitably according to the kind of material.

  The method for forming the light control unit is not particularly limited. For example, a method for applying a light control unit forming composition containing a material for the light control unit, filling the groove of the light transmission unit, and curing it. Can be used.

The application method of the composition for forming a light control part is not particularly limited as long as it can be sufficiently filled in at least the groove part. Wiping method, coating method, dry laminating method, extrusion laminating method Etc. can be used. Further, when applying the light control part forming composition, the excessive amount of the light control part forming composition that has flowed out from the groove to the surface of the light transmitting part may be removed by scraping with a squeegee or the like. Good.
As the curing method of the composition for forming a light control unit, curing by irradiation with ionizing radiation such as ultraviolet rays and electron beams is preferable, and curing conditions and the like can be appropriately set according to the material and the type of ionizing radiation. .

(2) Other optical layers As the other optical layers, for example, a prism type optical layer or the like can be used. The prism type optical layer has a function of controlling the incident direction of light to the indoor side by polarizing and reflecting external light. For example, as shown in FIG. 5, the prism-type optical layer 2B has a structure including a plurality of unit prisms 31 having a trapezoidal cross section, and totally reflects external light on the polarization plane 31a of the unit prism 31 to obtain a desired polarization. As a result, the incident direction when external light enters the room can be controlled. Here, the unit prism includes a polymer having an alkoxy group-containing bisphenol A type (meth) acrylate compound as a constituent unit.
Note that the space between adjacent unit prisms (portion indicated by 32 in FIG. 5) may be filled with air, or may be filled with a material having a different bending rate from that of the unit prism.

  The details of the structure of the unit prism and the like can be the same as the details of the unit prism described in, for example, Japanese Patent Application Laid-Open No. 2013-15569.

  The thickness of the prism type optical layer is preferably 10 μm or more and 200 μm or less. If the film thickness is smaller than the above range, the optical performance may be insufficient, or the prism type optical layer may be finely processed and the accuracy may be lowered. On the other hand, if it is larger than the above range, peeling from the mold may be difficult when the prism-type optical layer is molded.

3. Base Material The optical member of the present invention may have a base material. The substrate is usually disposed on the surface opposite to the surface on which the adhesive layer of the optical layer is provided.

  The substrate is not particularly limited as long as it has light transmittance and does not adversely affect visibility. For example, a sheet or film made of a resin having transparency, inorganic glass, organic glass, inorganic -The glass plate etc. which consist of organic hybrid glass etc. can be used, and a film is preferable especially.

  As the resin used for the substrate, any resin may be used as long as it has transparency and has a strength capable of supporting the optical layer and the like. For example, polyethylene terephthalate, polycarbonate, polyester, polyurethane, polyvinyl alcohol, polycarbonate, vinyl chloride, fluororesin, rubber and the like can be used. Of these, polyethylene terephthalate and polycarbonate are preferable from the viewpoint of transparency and strength. Further, the base material may contain an antioxidant, an ultraviolet absorber and the like.

  The base material may be subjected to surface treatment or the like on one side or both sides as necessary. Surface treatments include corona discharge treatment, chromic acid treatment (wet), flame treatment, hot air treatment, surface treatment by oxidation methods such as ozone ultraviolet irradiation treatment, surface treatment by roughening methods such as sandblasting and solvent treatment methods, chemical treatment Surface treatment and the like.

  The film thickness of the substrate can be appropriately set according to the use, but is usually within the range of 5 μm to 200 μm, and preferably within the range of 10 μm to 150 μm. If the film thickness of the substrate is smaller than the above range, curls, wrinkles and the like are likely to enter, and the strength of the optical member may not be obtained.

4). Release Layer The optical member of the present invention preferably has a release layer on the adhesive layer. By having the release layer, it is possible to prevent adhesion of dust or the like to the adhesive layer, and to prevent the visibility of the optical member from being deteriorated due to dirt. Further, when the optical member wound up in a roll shape is unwound, the surface of the adhesive layer becomes rough, and the occurrence of unwinding failure can be prevented.

  The material of the release layer is not particularly limited as long as it is generally used. Examples thereof include acrylic and methacrylic resins such as polymethyl acrylate and polymethyl methacrylate, polyvinyl chloride resin, cellulose resin, silicon resin, chlorinated rubber, casein, various surfactants, and metal oxides. These materials may be used alone or in combination of two or more.

5. Arbitrary layer The optical member of this invention may have arbitrary layers other than the above-mentioned structure. For example, an overcoat layer may be provided between the adhesive layer and the optical layer from the viewpoint of improving the adhesion between the adhesive layer and the optical layer and improving the appearance.

  As a material for the overcoat layer, an ionizing radiation curable resin is preferably used, and can be appropriately selected from a polymerizable oligomer or a prepolymer. Among these, it is preferable to use a polyfunctional polymerizable oligomer or prepolymer.

  In addition, when polyfunctional urethane (meth) acrylate is used as the material for the overcoat layer, a diluent such as monofunctional (meth) acrylate such as methyl (meth) acrylate is used for the purpose of adjusting the viscosity. Can be used in combination. The monofunctional (meth) acrylate may be used alone or in combination of two or more, or a low molecular weight polyfunctional (meth) acrylate may be used in combination. Moreover, as a diluent, applicability | paintability can also be ensured using said monomer.

  The overcoat layer may contain an ultraviolet absorber, a light stabilizer, a silicate compound, and the like. The details of the ultraviolet absorber and the light stabilizer are the same as those described above.

  The thickness of the overcoat layer is preferably in the range of 0 μm to 40 μm, more preferably in the range of 0 μm to 20 μm, and particularly preferably in the range of 0 μm to 10 μm.

  As a method for forming the overcoat layer, for example, a coating solution obtained by diluting the above-described material with a desired solvent can be prepared, and the coating solution can be applied on a substrate. As an application method, for example, an applicator coat, a wire bar coat, a gravure coater, a die coater or the like can be used.

  Moreover, as another arbitrary layer, you may have a scratch-resistant layer, a self-cleaning layer, etc. in the surface side which does not have the contact bonding layer of an optical layer. In addition, when an optical layer is bonded with a base material, these layers are arrange | positioned on one surface of an optical layer through the said base material. The details of the scratch-resistant layer, the self-cleaning layer and the like can be the same as those of the overcoat layer described above.

6). Optical member The visible light transmittance of the optical member of the present invention is preferably 65% or more when the incident angle of outside light is 0 °, more preferably 70% or more, particularly 85% or more. Preferably there is. By making the visible light transmittance within the above range when the incident angle of external light is 0 °, the appearance and the like can be clearly observed. In addition, since the amount of visible light taken into the room or the like increases, the illuminance in the room can be secured by using outside light. The incident angle here refers to the angle θ shown in FIG.
The visible light transmittance was measured using a infrared visible ultraviolet spectrophotometer (UV3100PC, manufactured by Shimadzu Corporation) and measured in the wavelength range of 380 nm to 780 nm according to JIS A5759-2008. It is calculated by the calculation formula prescribed in 1.

  In the present invention, the positional relationship between the adhesive layer and the optical layer described above is not particularly limited, and can be appropriately selected according to the use and location of the optical member. Since the triazole-based compound has an ultraviolet absorbing function, the adhesive layer is preferably disposed on the light source side of the optical layer. In this case, the optical member of the present invention is used mainly for indoor use.

7). Applications The optical member of the present invention can be used by being attached to, for example, vehicles such as buildings, houses, trains, cars, buses, window glass, openings, etc. of airplanes, ships and the like.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

[Example 1]
(Formation of optical layer)
The optical layer was formed by the following method.

(1) Formation of light-transmitting part and groove part A liquid light-transmitting part forming resin composition A having the following composition is cured on one surface of a continuous belt-like transparent biaxially stretched PET film (film thickness: 100 μm). It applied so that the film thickness after that might be set to 200 micrometers.

<Light transmission part forming composition A>
-EO-modified bisphenol A diacrylate (product name: A-BPE-10, manufactured by Nakamura Chemical Co., Ltd.) ... 100 parts by mass-benzophenone photoinitiator (trade name: Irgacure 184, manufactured by BASF) ... 1 part by mass

  Next, a trapezoidal convex having a main cut surface with a height of 150 μm, a plate surface side width of 28 μm, and a width far from the plate surface of 24 μm is linearly connected in the circumferential direction along the surface direction of the surface. A roll mold was prepared in which protrusions (the same shape as the light control unit and reverse unevenness) in which a plurality of portions were arranged in parallel with each other at a period of 78 μm were prepared. In a state where the composition A for forming a light transmission part is sandwiched between the roll mold and the PET film, the composition A for light transmission part formation is crosslinked and cured by performing ultraviolet irradiation using a mercury lamp, The roll mold was peeled off to form a light transmission part having a groove part on the surface of the PET film. The shape of the groove part was a reversal shape of the convex group of the roll mold described above, that is, a concave group having a trapezoidal longitudinal cross-sectional shape.

(2) Formation of light control part Next, the light control part as a heat ray absorption part was formed in the groove part. First, a liquid light control part forming composition having the following composition was prepared, and after applying this to the groove part of the light transmission part, squeezing with an iron doctor blade and filling only into the concave groove, The light control part was formed by irradiating with ultraviolet rays and crosslinking and curing to obtain a louver type optical layer.

<Light control part forming composition>
-Polyethylene glycol # 600 diacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., A-600) ... 99 parts by mass-1-hydroxycyclohexyl-phenyl-ketone (photopolymerization initiator, product name: Irgacure 184, manufactured by BASF) ... 1 part by mass

(Formation of adhesive layer)
Benzotriazole compound A (product) as an ultraviolet absorber with respect to 100 parts by mass of an acrylic adhesive (product name: SK Dyne 1429DT, solid content 30%, manufactured by Soken Chemical Co., Ltd.) mainly composed of an acrylic ester copolymer Name: Tinuvin 928, manufactured by BASF Japan Ltd.) 4 parts by mass (solid content 1.18 parts by mass) were dissolved. Furthermore, 0.5 mass part (solid content ratio) of isocyanate crosslinking agent A (product name: Y-75, manufactured by Soken Chemical Co., Ltd.) was added as a crosslinking agent and stirred for 10 minutes to obtain an adhesive layer coating solution.
Then, the above adhesive layer coating solution is applied on the surface of the optical layer where the light control part of the optical layer is formed with an applicator so that the wet film thickness is 83 μm, and dried at 80 ° C. for 2 minutes, and then bonded with urethane. An adhesion layer (film thickness after drying: 25 μm) containing an acrylic polymer having a cross-linked structure and a benzotriazole compound A was formed.
A light release separator film (film thickness: 38 μm, product name: E7006, manufactured by Toyobo Co., Ltd.) having a small silicon transferability was laminated on the adhesive layer to obtain an optical member.

[Example 2]
An optical member was obtained in the same manner as in Example 1 except that the crosslinking agent in the adhesive layer coating solution was isocyanate crosslinking agent B (product name: TD-75, manufactured by Soken Chemical Co., Ltd.).

[Example 3]
An optical member was obtained in the same manner as in Example 1 except that the crosslinking agent in the adhesive layer coating solution was isocyanate crosslinking agent C (product name: L-45E, manufactured by Soken Chemical Co., Ltd.).

[Example 4]
An optical member was obtained in the same manner as in Example 1 except that the ultraviolet absorber in the adhesive layer coating solution was benzotriazole compound B (product name: Tinuvin 384-2, manufactured by BASF Japan Ltd.).

[Example 5]
An optical member was obtained in the same manner as in Example 1 except that the following light control part forming composition was used for forming the light control part.
<Light control part forming composition>
・ Transparent acrylic UV curable prepolymer (binder resin) consisting of a mixture of urethane acrylate (Daicel Cytec) and dipentaerythritol acrylate oligomer (Shin-Nakamura Chemical Co., Ltd.)… 100 parts by mass ・ ATO nanoparticles (average particle) (Diameter 100 nm) 4.5 parts by mass (Mitsubishi Materials Corporation)
・ LaB: 0.6 parts by mass (manufactured by Sumitomo Metal Mining)
1-hydroxy-cyclohexyl-phenyl-ketone (photopolymerization initiator, product name: Irgacure 184, manufactured by BASF) 1 part by mass

[Comparative Example 1]
An optical member was obtained in the same manner as in Example 1 except that the cross-linking agent in the adhesive layer coating solution was a metal chelate cross-linking agent (product name: AD-5A, manufactured by Soken Chemical Co., Ltd.).

[Comparative Example 2]
An optical member was obtained in the same manner as in Example 1 except that the crosslinking agent in the adhesive layer coating solution was an epoxy crosslinking agent (product name: E-5XM, manufactured by Soken Chemical Co., Ltd.).

[Comparative Example 3]
An optical member was obtained in the same manner as in Example 1 except that the crosslinking agent in the adhesive layer coating solution was dicyandiamide crosslinking agent (product name: CP-66, manufactured by ADEKA).

[Comparative Example 4]
An optical member was obtained in the same manner as in Example 1 except that the ultraviolet absorber in the adhesive layer coating solution was a cyanoacrylate compound (product name: Biosoap 930, manufactured by Kyodo Pharmaceutical Co., Ltd.).

[Comparative Example 5]
An optical member was obtained in the same manner as in Example 1 except that the ultraviolet absorber in the adhesive layer coating solution was a triazine compound (product name: Tinuvin 477, manufactured by BASF Japan Ltd.).

[Evaluation]
<Initial yellowness (b ^* )>
About each optical member of an Example and a comparative example, each optical member is bonded to the glass plate (product made from Tokyo special glass) of length 100mm, width 100mm, and film thickness 2.8mm via an adhesive layer, and the weather resistance test mentioned later Prior to the above, yellowing at the time of initial bonding was confirmed by visual observation and measuring the initial yellowness (b ^* ) from the glass surface side of the glass plate.
The initial yellowness (b ^* ) is measured using a spectrophotometer (UV-3100PC manufactured by Shimadzu Corporation, JIS K 0115 compliant product) when measured within a measurement wavelength range of 380 nm to 780 nm. The visible light transmittance at each wavelength was measured, and b ^* was calculated according to the CIE 1976 (L ^* , a ^* , b ^* ) color space. The b ^* value was less than 2, and the two or more were marked with x. When the b ^* value is less than 2, the transparency of the test piece is maintained and good weather resistance is exhibited, and when the b ^* value is 2 or more, yellowing at a level that causes a practical problem in the test piece. Was recognized.

<Weather resistance test>
About each optical member bonded together to the said glass plate, the following using an accelerated ultraviolet-ray-deterioration tester (the Suga Test Instruments Co., Ltd. make, brand name: carbon arc lamp type accelerated weathering tester, model number: S300), (A) to (C) were set as one cycle, and this was repeated for 2000 hours to perform a weather resistance test.
(A) Black panel (BP) Irradiation with ultraviolet rays from a carbon arc lamp (illuminance: 255 W / m ² , wavelength: 300 nm to 700 nm) for 102 minutes in an atmosphere of temperature: 63 ° C. and humidity: 50% RH .
(B) Black panel (BP) Temperature: 63 ° C., humidity: 98% RH, while irradiating ultraviolet rays with a carbon arc lamp (illuminance: 255 W / m ² , wavelength: 300 nm to 700 nm), Sprinkle by shower for 18 minutes.

<Yellowing after weathering test>
About each test piece after a weather resistance test, yellowing was confirmed by measuring visually and a color difference from the glass plate surface side of each optical member. In the color difference measurement, a spectrophotometer (manufactured by Shimadzu Corporation, model number: UV-3100PC) was used, and the ΔE ^* ab value was measured by a transmission method in accordance with the description of JIS K7105. The ΔE ^* ab value is a color difference formula (ΔE ^* ab = {(ΔL ^* ) ² + (Δa ^* ) ² + (Δb ^* )) according to the (L ^* , a ^* , b ^* ) space color system of the CIE 1976 standard. ² } ^1/2 ). A ΔE ^* ab value of less than 3 was marked with ◯, and a value of 3 or more was marked with ×. When the ΔE ^* ab value is less than 3, no yellowing of the test piece is confirmed and good weather resistance is exhibited. When the ΔE ^* ab value is 3 or more, the test piece has a practically problematic level. Yellowing was recognized.

<Retention force after weather resistance test>
About each test piece after a weather resistance test, Tensilon (product name: RTG-1205, manufactured by A & D Co., Ltd.) is used, and a head having a maximum load capacity of 0.5 kN is used according to JIS A 5759. Measurements were made. A holding force of 4N or more was rated as “◯”, and a holding force of less than 4N was marked as “X”. In the test piece having a holding power of less than 4N, peeling was lightened, and a decrease in holding power with respect to the glass plate was confirmed.

Table 1 shows the results of initial yellowness (b ^* ), yellowing after the weather resistance test, and holding power after the weather resistance test.

  In optical members (Examples 1 to 5) using an isocyanate crosslinking agent and a benzotriazole-based compound in the adhesive layer, yellowing after the initial and weather resistance tests was not confirmed, and the retention strength after the weather resistance test was also good. It was. However, the optical layer was the same as in Example 1, and in the optical member using the metal chelate crosslinking agent (Comparative Example 1) instead of the isocyanate crosslinking agent in the adhesive layer, the results after the weather resistance test were good. However, initial yellowing was confirmed. Moreover, in the optical member using the epoxy crosslinking agent (Comparative Example 2) and the dicyandiamide crosslinking agent (Comparative Example 3), initial yellowing and yellowing after the weather resistance test were confirmed, and the holding power after the weather resistance test was also reduced. did. Further, in the adhesive layer, initial yellowing was not confirmed in the optical member using the cyanoacrylate compound (Comparative Example 4) and the triazine compound (Comparative Example 5) instead of the benzotriazole compound, but the weather resistance Yellowing after the test and a decrease in holding power were confirmed.

DESCRIPTION OF SYMBOLS 1 ... Adhesive layer 2, 2A, 2B ... Optical layer 10 ... Optical member

Claims (4)

An optical member having at least an optical layer and an adhesive layer,
The adhesive layer includes an acrylic polymer having a cross-linked structure due to a urethane bond, and a benzotriazole-based compound,
The optical member comprising a polymer having an alkoxy group-containing bisphenol A type (meth) acrylate compound as a structural unit.   The optical member according to claim 1, wherein the benzotriazole-based compound is present in the adhesive layer in a form of being added as an additive.   2. The optical member according to claim 1, wherein the benzotriazole-based compound is present in the adhesive layer in a form bonded to a molecule constituting the acrylic polymer having a crosslinked structure by the urethane bond.   The optical member according to any one of claims 1 to 3, wherein the optical layer increases the amount of light collected using reflected light.

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